xref: /trueos/sys/netpfil/pf/pf.c (revision 5868f7205430cd67aa3b655419d3f15f83b70119)
1 /*-
2  * Copyright (c) 2001 Daniel Hartmeier
3  * Copyright (c) 2002 - 2008 Henning Brauer
4  * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  *    - Redistributions of source code must retain the above copyright
12  *      notice, this list of conditions and the following disclaimer.
13  *    - Redistributions in binary form must reproduce the above
14  *      copyright notice, this list of conditions and the following
15  *      disclaimer in the documentation and/or other materials provided
16  *      with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
26  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
28  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  *
31  * Effort sponsored in part by the Defense Advanced Research Projects
32  * Agency (DARPA) and Air Force Research Laboratory, Air Force
33  * Materiel Command, USAF, under agreement number F30602-01-2-0537.
34  *
35  *	$OpenBSD: pf.c,v 1.634 2009/02/27 12:37:45 henning Exp $
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "opt_inet.h"
42 #include "opt_inet6.h"
43 #include "opt_bpf.h"
44 #include "opt_pf.h"
45 
46 #include <sys/param.h>
47 #include <sys/bus.h>
48 #include <sys/endian.h>
49 #include <sys/hash.h>
50 #include <sys/interrupt.h>
51 #include <sys/kernel.h>
52 #include <sys/kthread.h>
53 #include <sys/limits.h>
54 #include <sys/mbuf.h>
55 #include <sys/md5.h>
56 #include <sys/random.h>
57 #include <sys/refcount.h>
58 #include <sys/socket.h>
59 #include <sys/sysctl.h>
60 #include <sys/taskqueue.h>
61 #include <sys/ucred.h>
62 
63 #include <net/if.h>
64 #include <net/if_types.h>
65 #include <net/route.h>
66 #include <net/radix_mpath.h>
67 #include <net/vnet.h>
68 
69 #include <net/pfvar.h>
70 #include <net/if_pflog.h>
71 #include <net/if_pfsync.h>
72 
73 #include <netinet/in_pcb.h>
74 #include <netinet/in_var.h>
75 #include <netinet/ip.h>
76 #include <netinet/ip_fw.h>
77 #include <netinet/ip_icmp.h>
78 #include <netinet/icmp_var.h>
79 #include <netinet/ip_var.h>
80 #include <netinet/tcp.h>
81 #include <netinet/tcp_fsm.h>
82 #include <netinet/tcp_seq.h>
83 #include <netinet/tcp_timer.h>
84 #include <netinet/tcp_var.h>
85 #include <netinet/udp.h>
86 #include <netinet/udp_var.h>
87 
88 #include <netpfil/ipfw/ip_fw_private.h> /* XXX: only for DIR_IN/DIR_OUT */
89 
90 #ifdef INET6
91 #include <netinet/ip6.h>
92 #include <netinet/icmp6.h>
93 #include <netinet6/nd6.h>
94 #include <netinet6/ip6_var.h>
95 #include <netinet6/in6_pcb.h>
96 #endif /* INET6 */
97 
98 #include <machine/in_cksum.h>
99 #include <security/mac/mac_framework.h>
100 
101 #define	DPFPRINTF(n, x)	if (V_pf_status.debug >= (n)) printf x
102 
103 /*
104  * Global variables
105  */
106 
107 /* state tables */
108 VNET_DEFINE(struct pf_altqqueue,	 pf_altqs[2]);
109 VNET_DEFINE(struct pf_palist,		 pf_pabuf);
110 VNET_DEFINE(struct pf_altqqueue *,	 pf_altqs_active);
111 VNET_DEFINE(struct pf_altqqueue *,	 pf_altqs_inactive);
112 VNET_DEFINE(struct pf_kstatus,		 pf_status);
113 
114 VNET_DEFINE(u_int32_t,			 ticket_altqs_active);
115 VNET_DEFINE(u_int32_t,			 ticket_altqs_inactive);
116 VNET_DEFINE(int,			 altqs_inactive_open);
117 VNET_DEFINE(u_int32_t,			 ticket_pabuf);
118 
119 VNET_DEFINE(MD5_CTX,			 pf_tcp_secret_ctx);
120 #define	V_pf_tcp_secret_ctx		 VNET(pf_tcp_secret_ctx)
121 VNET_DEFINE(u_char,			 pf_tcp_secret[16]);
122 #define	V_pf_tcp_secret			 VNET(pf_tcp_secret)
123 VNET_DEFINE(int,			 pf_tcp_secret_init);
124 #define	V_pf_tcp_secret_init		 VNET(pf_tcp_secret_init)
125 VNET_DEFINE(int,			 pf_tcp_iss_off);
126 #define	V_pf_tcp_iss_off		 VNET(pf_tcp_iss_off)
127 
128 /*
129  * Queue for pf_intr() sends.
130  */
131 static MALLOC_DEFINE(M_PFTEMP, "pf_temp", "pf(4) temporary allocations");
132 struct pf_send_entry {
133 	STAILQ_ENTRY(pf_send_entry)	pfse_next;
134 	struct mbuf			*pfse_m;
135 	enum {
136 		PFSE_IP,
137 		PFSE_IP6,
138 		PFSE_ICMP,
139 		PFSE_ICMP6,
140 	}				pfse_type;
141 	union {
142 		struct route		ro;
143 		struct {
144 			int		type;
145 			int		code;
146 			int		mtu;
147 		} icmpopts;
148 	} u;
149 #define	pfse_ro		u.ro
150 #define	pfse_icmp_type	u.icmpopts.type
151 #define	pfse_icmp_code	u.icmpopts.code
152 #define	pfse_icmp_mtu	u.icmpopts.mtu
153 };
154 
155 STAILQ_HEAD(pf_send_head, pf_send_entry);
156 static VNET_DEFINE(struct pf_send_head, pf_sendqueue);
157 #define	V_pf_sendqueue	VNET(pf_sendqueue)
158 
159 static struct mtx pf_sendqueue_mtx;
160 #define	PF_SENDQ_LOCK()		mtx_lock(&pf_sendqueue_mtx)
161 #define	PF_SENDQ_UNLOCK()	mtx_unlock(&pf_sendqueue_mtx)
162 
163 /*
164  * Queue for pf_overload_task() tasks.
165  */
166 struct pf_overload_entry {
167 	SLIST_ENTRY(pf_overload_entry)	next;
168 	struct pf_addr  		addr;
169 	sa_family_t			af;
170 	uint8_t				dir;
171 	struct pf_rule  		*rule;
172 };
173 
174 SLIST_HEAD(pf_overload_head, pf_overload_entry);
175 static VNET_DEFINE(struct pf_overload_head, pf_overloadqueue);
176 #define V_pf_overloadqueue	VNET(pf_overloadqueue)
177 static VNET_DEFINE(struct task, pf_overloadtask);
178 #define	V_pf_overloadtask	VNET(pf_overloadtask)
179 
180 static struct mtx pf_overloadqueue_mtx;
181 #define	PF_OVERLOADQ_LOCK()	mtx_lock(&pf_overloadqueue_mtx)
182 #define	PF_OVERLOADQ_UNLOCK()	mtx_unlock(&pf_overloadqueue_mtx)
183 
184 VNET_DEFINE(struct pf_rulequeue, pf_unlinked_rules);
185 struct mtx pf_unlnkdrules_mtx;
186 
187 static VNET_DEFINE(uma_zone_t,	pf_sources_z);
188 #define	V_pf_sources_z	VNET(pf_sources_z)
189 uma_zone_t		pf_mtag_z;
190 VNET_DEFINE(uma_zone_t,	 pf_state_z);
191 VNET_DEFINE(uma_zone_t,	 pf_state_key_z);
192 
193 VNET_DEFINE(uint64_t, pf_stateid[MAXCPU]);
194 #define	PFID_CPUBITS	8
195 #define	PFID_CPUSHIFT	(sizeof(uint64_t) * NBBY - PFID_CPUBITS)
196 #define	PFID_CPUMASK	((uint64_t)((1 << PFID_CPUBITS) - 1) <<	PFID_CPUSHIFT)
197 #define	PFID_MAXID	(~PFID_CPUMASK)
198 CTASSERT((1 << PFID_CPUBITS) >= MAXCPU);
199 
200 static void		 pf_src_tree_remove_state(struct pf_state *);
201 static void		 pf_init_threshold(struct pf_threshold *, u_int32_t,
202 			    u_int32_t);
203 static void		 pf_add_threshold(struct pf_threshold *);
204 static int		 pf_check_threshold(struct pf_threshold *);
205 
206 static void		 pf_change_ap(struct pf_addr *, u_int16_t *,
207 			    u_int16_t *, u_int16_t *, struct pf_addr *,
208 			    u_int16_t, u_int8_t, sa_family_t);
209 static int		 pf_modulate_sack(struct mbuf *, int, struct pf_pdesc *,
210 			    struct tcphdr *, struct pf_state_peer *);
211 static void		 pf_change_icmp(struct pf_addr *, u_int16_t *,
212 			    struct pf_addr *, struct pf_addr *, u_int16_t,
213 			    u_int16_t *, u_int16_t *, u_int16_t *,
214 			    u_int16_t *, u_int8_t, sa_family_t);
215 static void		 pf_send_tcp(struct mbuf *,
216 			    const struct pf_rule *, sa_family_t,
217 			    const struct pf_addr *, const struct pf_addr *,
218 			    u_int16_t, u_int16_t, u_int32_t, u_int32_t,
219 			    u_int8_t, u_int16_t, u_int16_t, u_int8_t, int,
220 			    u_int16_t, struct ifnet *);
221 static void		 pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t,
222 			    sa_family_t, struct pf_rule *);
223 static void		 pf_detach_state(struct pf_state *);
224 static int		 pf_state_key_attach(struct pf_state_key *,
225 			    struct pf_state_key *, struct pf_state *);
226 static void		 pf_state_key_detach(struct pf_state *, int);
227 static int		 pf_state_key_ctor(void *, int, void *, int);
228 static u_int32_t	 pf_tcp_iss(struct pf_pdesc *);
229 static int		 pf_test_rule(struct pf_rule **, struct pf_state **,
230 			    int, struct pfi_kif *, struct mbuf *, int,
231 			    struct pf_pdesc *, struct pf_rule **,
232 			    struct pf_ruleset **, struct inpcb *);
233 static int		 pf_create_state(struct pf_rule *, struct pf_rule *,
234 			    struct pf_rule *, struct pf_pdesc *,
235 			    struct pf_src_node *, struct pf_state_key *,
236 			    struct pf_state_key *, struct mbuf *, int,
237 			    u_int16_t, u_int16_t, int *, struct pfi_kif *,
238 			    struct pf_state **, int, u_int16_t, u_int16_t,
239 			    int);
240 static int		 pf_test_fragment(struct pf_rule **, int,
241 			    struct pfi_kif *, struct mbuf *, void *,
242 			    struct pf_pdesc *, struct pf_rule **,
243 			    struct pf_ruleset **);
244 static int		 pf_tcp_track_full(struct pf_state_peer *,
245 			    struct pf_state_peer *, struct pf_state **,
246 			    struct pfi_kif *, struct mbuf *, int,
247 			    struct pf_pdesc *, u_short *, int *);
248 static int		 pf_tcp_track_sloppy(struct pf_state_peer *,
249 			    struct pf_state_peer *, struct pf_state **,
250 			    struct pf_pdesc *, u_short *);
251 static int		 pf_test_state_tcp(struct pf_state **, int,
252 			    struct pfi_kif *, struct mbuf *, int,
253 			    void *, struct pf_pdesc *, u_short *);
254 static int		 pf_test_state_udp(struct pf_state **, int,
255 			    struct pfi_kif *, struct mbuf *, int,
256 			    void *, struct pf_pdesc *);
257 static int		 pf_test_state_icmp(struct pf_state **, int,
258 			    struct pfi_kif *, struct mbuf *, int,
259 			    void *, struct pf_pdesc *, u_short *);
260 static int		 pf_test_state_other(struct pf_state **, int,
261 			    struct pfi_kif *, struct mbuf *, struct pf_pdesc *);
262 static u_int8_t		 pf_get_wscale(struct mbuf *, int, u_int16_t,
263 			    sa_family_t);
264 static u_int16_t	 pf_get_mss(struct mbuf *, int, u_int16_t,
265 			    sa_family_t);
266 static u_int16_t	 pf_calc_mss(struct pf_addr *, sa_family_t,
267 				int, u_int16_t);
268 static int		 pf_check_proto_cksum(struct mbuf *, int, int,
269 			    u_int8_t, sa_family_t);
270 static void		 pf_print_state_parts(struct pf_state *,
271 			    struct pf_state_key *, struct pf_state_key *);
272 static int		 pf_addr_wrap_neq(struct pf_addr_wrap *,
273 			    struct pf_addr_wrap *);
274 static struct pf_state	*pf_find_state(struct pfi_kif *,
275 			    struct pf_state_key_cmp *, u_int);
276 static int		 pf_src_connlimit(struct pf_state **);
277 static void		 pf_overload_task(void *v, int pending);
278 static int		 pf_insert_src_node(struct pf_src_node **,
279 			    struct pf_rule *, struct pf_addr *, sa_family_t);
280 static u_int		 pf_purge_expired_states(u_int, int);
281 static void		 pf_purge_unlinked_rules(void);
282 static int		 pf_mtag_uminit(void *, int, int);
283 static void		 pf_mtag_free(struct m_tag *);
284 #ifdef INET
285 static void		 pf_route(struct mbuf **, struct pf_rule *, int,
286 			    struct ifnet *, struct pf_state *,
287 			    struct pf_pdesc *);
288 #endif /* INET */
289 #ifdef INET6
290 static void		 pf_change_a6(struct pf_addr *, u_int16_t *,
291 			    struct pf_addr *, u_int8_t);
292 static void		 pf_route6(struct mbuf **, struct pf_rule *, int,
293 			    struct ifnet *, struct pf_state *,
294 			    struct pf_pdesc *);
295 #endif /* INET6 */
296 
297 int in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len);
298 
299 VNET_DECLARE(int, pf_end_threads);
300 
301 VNET_DEFINE(struct pf_limit, pf_limits[PF_LIMIT_MAX]);
302 
303 #define	PACKET_LOOPED(pd)	((pd)->pf_mtag &&			\
304 				 (pd)->pf_mtag->flags & PF_PACKET_LOOPED)
305 
306 #define	STATE_LOOKUP(i, k, d, s, pd)					\
307 	do {								\
308 		(s) = pf_find_state((i), (k), (d));			\
309 		if ((s) == NULL)					\
310 			return (PF_DROP);				\
311 		if (PACKET_LOOPED(pd))					\
312 			return (PF_PASS);				\
313 		if ((d) == PF_OUT &&					\
314 		    (((s)->rule.ptr->rt == PF_ROUTETO &&		\
315 		    (s)->rule.ptr->direction == PF_OUT) ||		\
316 		    ((s)->rule.ptr->rt == PF_REPLYTO &&			\
317 		    (s)->rule.ptr->direction == PF_IN)) &&		\
318 		    (s)->rt_kif != NULL &&				\
319 		    (s)->rt_kif != (i))					\
320 			return (PF_PASS);				\
321 	} while (0)
322 
323 #define	BOUND_IFACE(r, k) \
324 	((r)->rule_flag & PFRULE_IFBOUND) ? (k) : V_pfi_all
325 
326 #define	STATE_INC_COUNTERS(s)						\
327 	do {								\
328 		counter_u64_add(s->rule.ptr->states_cur, 1);		\
329 		counter_u64_add(s->rule.ptr->states_tot, 1);		\
330 		if (s->anchor.ptr != NULL) {				\
331 			counter_u64_add(s->anchor.ptr->states_cur, 1);	\
332 			counter_u64_add(s->anchor.ptr->states_tot, 1);	\
333 		}							\
334 		if (s->nat_rule.ptr != NULL) {				\
335 			counter_u64_add(s->nat_rule.ptr->states_cur, 1);\
336 			counter_u64_add(s->nat_rule.ptr->states_tot, 1);\
337 		}							\
338 	} while (0)
339 
340 #define	STATE_DEC_COUNTERS(s)						\
341 	do {								\
342 		if (s->nat_rule.ptr != NULL)				\
343 			counter_u64_add(s->nat_rule.ptr->states_cur, -1);\
344 		if (s->anchor.ptr != NULL)				\
345 			counter_u64_add(s->anchor.ptr->states_cur, -1);	\
346 		counter_u64_add(s->rule.ptr->states_cur, -1);		\
347 	} while (0)
348 
349 static MALLOC_DEFINE(M_PFHASH, "pf_hash", "pf(4) hash header structures");
350 VNET_DEFINE(struct pf_keyhash *, pf_keyhash);
351 VNET_DEFINE(struct pf_idhash *, pf_idhash);
352 VNET_DEFINE(struct pf_srchash *, pf_srchash);
353 
354 SYSCTL_NODE(_net, OID_AUTO, pf, CTLFLAG_RW, 0, "pf(4)");
355 
356 u_long	pf_hashmask;
357 u_long	pf_srchashmask;
358 static u_long	pf_hashsize;
359 static u_long	pf_srchashsize;
360 
361 SYSCTL_ULONG(_net_pf, OID_AUTO, states_hashsize, CTLFLAG_RDTUN,
362     &pf_hashsize, 0, "Size of pf(4) states hashtable");
363 SYSCTL_ULONG(_net_pf, OID_AUTO, source_nodes_hashsize, CTLFLAG_RDTUN,
364     &pf_srchashsize, 0, "Size of pf(4) source nodes hashtable");
365 
366 VNET_DEFINE(void *, pf_swi_cookie);
367 
368 VNET_DEFINE(uint32_t, pf_hashseed);
369 #define	V_pf_hashseed	VNET(pf_hashseed)
370 
371 static __inline uint32_t
pf_hashkey(struct pf_state_key * sk)372 pf_hashkey(struct pf_state_key *sk)
373 {
374 	uint32_t h;
375 
376 	h = murmur3_aligned_32((uint32_t *)sk,
377 			       sizeof(struct pf_state_key_cmp),
378 			       V_pf_hashseed);
379 
380 	return (h & pf_hashmask);
381 }
382 
383 static __inline uint32_t
pf_hashsrc(struct pf_addr * addr,sa_family_t af)384 pf_hashsrc(struct pf_addr *addr, sa_family_t af)
385 {
386 	uint32_t h;
387 
388 	switch (af) {
389 	case AF_INET:
390 		h = murmur3_aligned_32((uint32_t *)&addr->v4,
391 				       sizeof(addr->v4), V_pf_hashseed);
392 		break;
393 	case AF_INET6:
394 		h = murmur3_aligned_32((uint32_t *)&addr->v6,
395 				       sizeof(addr->v6), V_pf_hashseed);
396 		break;
397 	default:
398 		panic("%s: unknown address family %u", __func__, af);
399 	}
400 
401 	return (h & pf_srchashmask);
402 }
403 
404 #ifdef INET6
405 void
pf_addrcpy(struct pf_addr * dst,struct pf_addr * src,sa_family_t af)406 pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af)
407 {
408 	switch (af) {
409 #ifdef INET
410 	case AF_INET:
411 		dst->addr32[0] = src->addr32[0];
412 		break;
413 #endif /* INET */
414 	case AF_INET6:
415 		dst->addr32[0] = src->addr32[0];
416 		dst->addr32[1] = src->addr32[1];
417 		dst->addr32[2] = src->addr32[2];
418 		dst->addr32[3] = src->addr32[3];
419 		break;
420 	}
421 }
422 #endif /* INET6 */
423 
424 static void
pf_init_threshold(struct pf_threshold * threshold,u_int32_t limit,u_int32_t seconds)425 pf_init_threshold(struct pf_threshold *threshold,
426     u_int32_t limit, u_int32_t seconds)
427 {
428 	threshold->limit = limit * PF_THRESHOLD_MULT;
429 	threshold->seconds = seconds;
430 	threshold->count = 0;
431 	threshold->last = time_uptime;
432 }
433 
434 static void
pf_add_threshold(struct pf_threshold * threshold)435 pf_add_threshold(struct pf_threshold *threshold)
436 {
437 	u_int32_t t = time_uptime, diff = t - threshold->last;
438 
439 	if (diff >= threshold->seconds)
440 		threshold->count = 0;
441 	else
442 		threshold->count -= threshold->count * diff /
443 		    threshold->seconds;
444 	threshold->count += PF_THRESHOLD_MULT;
445 	threshold->last = t;
446 }
447 
448 static int
pf_check_threshold(struct pf_threshold * threshold)449 pf_check_threshold(struct pf_threshold *threshold)
450 {
451 	return (threshold->count > threshold->limit);
452 }
453 
454 static int
pf_src_connlimit(struct pf_state ** state)455 pf_src_connlimit(struct pf_state **state)
456 {
457 	struct pf_overload_entry *pfoe;
458 	int bad = 0;
459 
460 	PF_STATE_LOCK_ASSERT(*state);
461 
462 	(*state)->src_node->conn++;
463 	(*state)->src.tcp_est = 1;
464 	pf_add_threshold(&(*state)->src_node->conn_rate);
465 
466 	if ((*state)->rule.ptr->max_src_conn &&
467 	    (*state)->rule.ptr->max_src_conn <
468 	    (*state)->src_node->conn) {
469 		counter_u64_add(V_pf_status.lcounters[LCNT_SRCCONN], 1);
470 		bad++;
471 	}
472 
473 	if ((*state)->rule.ptr->max_src_conn_rate.limit &&
474 	    pf_check_threshold(&(*state)->src_node->conn_rate)) {
475 		counter_u64_add(V_pf_status.lcounters[LCNT_SRCCONNRATE], 1);
476 		bad++;
477 	}
478 
479 	if (!bad)
480 		return (0);
481 
482 	/* Kill this state. */
483 	(*state)->timeout = PFTM_PURGE;
484 	(*state)->src.state = (*state)->dst.state = TCPS_CLOSED;
485 
486 	if ((*state)->rule.ptr->overload_tbl == NULL)
487 		return (1);
488 
489 	/* Schedule overloading and flushing task. */
490 	pfoe = malloc(sizeof(*pfoe), M_PFTEMP, M_NOWAIT);
491 	if (pfoe == NULL)
492 		return (1);	/* too bad :( */
493 
494 	bcopy(&(*state)->src_node->addr, &pfoe->addr, sizeof(pfoe->addr));
495 	pfoe->af = (*state)->key[PF_SK_WIRE]->af;
496 	pfoe->rule = (*state)->rule.ptr;
497 	pfoe->dir = (*state)->direction;
498 	PF_OVERLOADQ_LOCK();
499 	SLIST_INSERT_HEAD(&V_pf_overloadqueue, pfoe, next);
500 	PF_OVERLOADQ_UNLOCK();
501 	taskqueue_enqueue(taskqueue_swi, &V_pf_overloadtask);
502 
503 	return (1);
504 }
505 
506 static void
pf_overload_task(void * v,int pending)507 pf_overload_task(void *v, int pending)
508 {
509 	struct pf_overload_head queue;
510 	struct pfr_addr p;
511 	struct pf_overload_entry *pfoe, *pfoe1;
512 	uint32_t killed = 0;
513 
514 	CURVNET_SET((struct vnet *)v);
515 
516 	PF_OVERLOADQ_LOCK();
517 	queue = V_pf_overloadqueue;
518 	SLIST_INIT(&V_pf_overloadqueue);
519 	PF_OVERLOADQ_UNLOCK();
520 
521 	bzero(&p, sizeof(p));
522 	SLIST_FOREACH(pfoe, &queue, next) {
523 		counter_u64_add(V_pf_status.lcounters[LCNT_OVERLOAD_TABLE], 1);
524 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
525 			printf("%s: blocking address ", __func__);
526 			pf_print_host(&pfoe->addr, 0, pfoe->af);
527 			printf("\n");
528 		}
529 
530 		p.pfra_af = pfoe->af;
531 		switch (pfoe->af) {
532 #ifdef INET
533 		case AF_INET:
534 			p.pfra_net = 32;
535 			p.pfra_ip4addr = pfoe->addr.v4;
536 			break;
537 #endif
538 #ifdef INET6
539 		case AF_INET6:
540 			p.pfra_net = 128;
541 			p.pfra_ip6addr = pfoe->addr.v6;
542 			break;
543 #endif
544 		}
545 
546 		PF_RULES_WLOCK();
547 		pfr_insert_kentry(pfoe->rule->overload_tbl, &p, time_second);
548 		PF_RULES_WUNLOCK();
549 	}
550 
551 	/*
552 	 * Remove those entries, that don't need flushing.
553 	 */
554 	SLIST_FOREACH_SAFE(pfoe, &queue, next, pfoe1)
555 		if (pfoe->rule->flush == 0) {
556 			SLIST_REMOVE(&queue, pfoe, pf_overload_entry, next);
557 			free(pfoe, M_PFTEMP);
558 		} else
559 			counter_u64_add(
560 			    V_pf_status.lcounters[LCNT_OVERLOAD_FLUSH], 1);
561 
562 	/* If nothing to flush, return. */
563 	if (SLIST_EMPTY(&queue)) {
564 		CURVNET_RESTORE();
565 		return;
566 	}
567 
568 	for (int i = 0; i <= pf_hashmask; i++) {
569 		struct pf_idhash *ih = &V_pf_idhash[i];
570 		struct pf_state_key *sk;
571 		struct pf_state *s;
572 
573 		PF_HASHROW_LOCK(ih);
574 		LIST_FOREACH(s, &ih->states, entry) {
575 		    sk = s->key[PF_SK_WIRE];
576 		    SLIST_FOREACH(pfoe, &queue, next)
577 			if (sk->af == pfoe->af &&
578 			    ((pfoe->rule->flush & PF_FLUSH_GLOBAL) ||
579 			    pfoe->rule == s->rule.ptr) &&
580 			    ((pfoe->dir == PF_OUT &&
581 			    PF_AEQ(&pfoe->addr, &sk->addr[1], sk->af)) ||
582 			    (pfoe->dir == PF_IN &&
583 			    PF_AEQ(&pfoe->addr, &sk->addr[0], sk->af)))) {
584 				s->timeout = PFTM_PURGE;
585 				s->src.state = s->dst.state = TCPS_CLOSED;
586 				killed++;
587 			}
588 		}
589 		PF_HASHROW_UNLOCK(ih);
590 	}
591 	SLIST_FOREACH_SAFE(pfoe, &queue, next, pfoe1)
592 		free(pfoe, M_PFTEMP);
593 	if (V_pf_status.debug >= PF_DEBUG_MISC)
594 		printf("%s: %u states killed", __func__, killed);
595 
596 	CURVNET_RESTORE();
597 }
598 
599 /*
600  * Can return locked on failure, so that we can consistently
601  * allocate and insert a new one.
602  */
603 struct pf_src_node *
pf_find_src_node(struct pf_addr * src,struct pf_rule * rule,sa_family_t af,int returnlocked)604 pf_find_src_node(struct pf_addr *src, struct pf_rule *rule, sa_family_t af,
605 	int returnlocked)
606 {
607 	struct pf_srchash *sh;
608 	struct pf_src_node *n;
609 
610 	counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_SEARCH], 1);
611 
612 	sh = &V_pf_srchash[pf_hashsrc(src, af)];
613 	PF_HASHROW_LOCK(sh);
614 	LIST_FOREACH(n, &sh->nodes, entry)
615 		if (n->rule.ptr == rule && n->af == af &&
616 		    ((af == AF_INET && n->addr.v4.s_addr == src->v4.s_addr) ||
617 		    (af == AF_INET6 && bcmp(&n->addr, src, sizeof(*src)) == 0)))
618 			break;
619 	if (n != NULL || returnlocked == 0)
620 		PF_HASHROW_UNLOCK(sh);
621 
622 	return (n);
623 }
624 
625 static int
pf_insert_src_node(struct pf_src_node ** sn,struct pf_rule * rule,struct pf_addr * src,sa_family_t af)626 pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule,
627     struct pf_addr *src, sa_family_t af)
628 {
629 
630 	KASSERT((rule->rule_flag & PFRULE_RULESRCTRACK ||
631 	    rule->rpool.opts & PF_POOL_STICKYADDR),
632 	    ("%s for non-tracking rule %p", __func__, rule));
633 
634 	if (*sn == NULL)
635 		*sn = pf_find_src_node(src, rule, af, 1);
636 
637 	if (*sn == NULL) {
638 		struct pf_srchash *sh = &V_pf_srchash[pf_hashsrc(src, af)];
639 
640 		PF_HASHROW_ASSERT(sh);
641 
642 		if (!rule->max_src_nodes ||
643 		    counter_u64_fetch(rule->src_nodes) < rule->max_src_nodes)
644 			(*sn) = uma_zalloc(V_pf_sources_z, M_NOWAIT | M_ZERO);
645 		else
646 			counter_u64_add(V_pf_status.lcounters[LCNT_SRCNODES],
647 			    1);
648 		if ((*sn) == NULL) {
649 			PF_HASHROW_UNLOCK(sh);
650 			return (-1);
651 		}
652 
653 		pf_init_threshold(&(*sn)->conn_rate,
654 		    rule->max_src_conn_rate.limit,
655 		    rule->max_src_conn_rate.seconds);
656 
657 		(*sn)->af = af;
658 		(*sn)->rule.ptr = rule;
659 		PF_ACPY(&(*sn)->addr, src, af);
660 		LIST_INSERT_HEAD(&sh->nodes, *sn, entry);
661 		(*sn)->creation = time_uptime;
662 		(*sn)->ruletype = rule->action;
663 		if ((*sn)->rule.ptr != NULL)
664 			counter_u64_add((*sn)->rule.ptr->src_nodes, 1);
665 		PF_HASHROW_UNLOCK(sh);
666 		counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_INSERT], 1);
667 	} else {
668 		if (rule->max_src_states &&
669 		    (*sn)->states >= rule->max_src_states) {
670 			counter_u64_add(V_pf_status.lcounters[LCNT_SRCSTATES],
671 			    1);
672 			return (-1);
673 		}
674 	}
675 	return (0);
676 }
677 
678 void
pf_unlink_src_node_locked(struct pf_src_node * src)679 pf_unlink_src_node_locked(struct pf_src_node *src)
680 {
681 #ifdef INVARIANTS
682 	struct pf_srchash *sh;
683 
684 	sh = &V_pf_srchash[pf_hashsrc(&src->addr, src->af)];
685 	PF_HASHROW_ASSERT(sh);
686 #endif
687 	LIST_REMOVE(src, entry);
688 	if (src->rule.ptr)
689 		counter_u64_add(src->rule.ptr->src_nodes, -1);
690 	counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_REMOVALS], 1);
691 }
692 
693 void
pf_unlink_src_node(struct pf_src_node * src)694 pf_unlink_src_node(struct pf_src_node *src)
695 {
696 	struct pf_srchash *sh;
697 
698 	sh = &V_pf_srchash[pf_hashsrc(&src->addr, src->af)];
699 	PF_HASHROW_LOCK(sh);
700 	pf_unlink_src_node_locked(src);
701 	PF_HASHROW_UNLOCK(sh);
702 }
703 
704 static void
pf_free_src_node(struct pf_src_node * sn)705 pf_free_src_node(struct pf_src_node *sn)
706 {
707 
708 	KASSERT(sn->states == 0, ("%s: %p has refs", __func__, sn));
709 	uma_zfree(V_pf_sources_z, sn);
710 }
711 
712 u_int
pf_free_src_nodes(struct pf_src_node_list * head)713 pf_free_src_nodes(struct pf_src_node_list *head)
714 {
715 	struct pf_src_node *sn, *tmp;
716 	u_int count = 0;
717 
718 	LIST_FOREACH_SAFE(sn, head, entry, tmp) {
719 		pf_free_src_node(sn);
720 		count++;
721 	}
722 
723 	return (count);
724 }
725 
726 void
pf_mtag_initialize()727 pf_mtag_initialize()
728 {
729 
730 	pf_mtag_z = uma_zcreate("pf mtags", sizeof(struct m_tag) +
731 	    sizeof(struct pf_mtag), NULL, NULL, pf_mtag_uminit, NULL,
732 	    UMA_ALIGN_PTR, 0);
733 }
734 
735 /* Per-vnet data storage structures initialization. */
736 void
pf_initialize()737 pf_initialize()
738 {
739 	struct pf_keyhash	*kh;
740 	struct pf_idhash	*ih;
741 	struct pf_srchash	*sh;
742 	u_int i;
743 
744 	TUNABLE_ULONG_FETCH("net.pf.states_hashsize", &pf_hashsize);
745 	if (pf_hashsize == 0 || !powerof2(pf_hashsize))
746 		pf_hashsize = PF_HASHSIZ;
747 	TUNABLE_ULONG_FETCH("net.pf.source_nodes_hashsize", &pf_srchashsize);
748 	if (pf_srchashsize == 0 || !powerof2(pf_srchashsize))
749 		pf_srchashsize = PF_HASHSIZ / 4;
750 
751 	V_pf_hashseed = arc4random();
752 
753 	/* States and state keys storage. */
754 	V_pf_state_z = uma_zcreate("pf states", sizeof(struct pf_state),
755 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
756 	V_pf_limits[PF_LIMIT_STATES].zone = V_pf_state_z;
757 	uma_zone_set_max(V_pf_state_z, PFSTATE_HIWAT);
758 	uma_zone_set_warning(V_pf_state_z, "PF states limit reached");
759 
760 	V_pf_state_key_z = uma_zcreate("pf state keys",
761 	    sizeof(struct pf_state_key), pf_state_key_ctor, NULL, NULL, NULL,
762 	    UMA_ALIGN_PTR, 0);
763 	V_pf_keyhash = malloc(pf_hashsize * sizeof(struct pf_keyhash),
764 	    M_PFHASH, M_WAITOK | M_ZERO);
765 	V_pf_idhash = malloc(pf_hashsize * sizeof(struct pf_idhash),
766 	    M_PFHASH, M_WAITOK | M_ZERO);
767 	pf_hashmask = pf_hashsize - 1;
768 	for (i = 0, kh = V_pf_keyhash, ih = V_pf_idhash; i <= pf_hashmask;
769 	    i++, kh++, ih++) {
770 		mtx_init(&kh->lock, "pf_keyhash", NULL, MTX_DEF | MTX_DUPOK);
771 		mtx_init(&ih->lock, "pf_idhash", NULL, MTX_DEF);
772 	}
773 
774 	/* Source nodes. */
775 	V_pf_sources_z = uma_zcreate("pf source nodes",
776 	    sizeof(struct pf_src_node), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
777 	    0);
778 	V_pf_limits[PF_LIMIT_SRC_NODES].zone = V_pf_sources_z;
779 	uma_zone_set_max(V_pf_sources_z, PFSNODE_HIWAT);
780 	uma_zone_set_warning(V_pf_sources_z, "PF source nodes limit reached");
781 	V_pf_srchash = malloc(pf_srchashsize * sizeof(struct pf_srchash),
782 	  M_PFHASH, M_WAITOK|M_ZERO);
783 	pf_srchashmask = pf_srchashsize - 1;
784 	for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++)
785 		mtx_init(&sh->lock, "pf_srchash", NULL, MTX_DEF);
786 
787 	/* ALTQ */
788 	TAILQ_INIT(&V_pf_altqs[0]);
789 	TAILQ_INIT(&V_pf_altqs[1]);
790 	TAILQ_INIT(&V_pf_pabuf);
791 	V_pf_altqs_active = &V_pf_altqs[0];
792 	V_pf_altqs_inactive = &V_pf_altqs[1];
793 
794 
795 	/* Send & overload+flush queues. */
796 	STAILQ_INIT(&V_pf_sendqueue);
797 	SLIST_INIT(&V_pf_overloadqueue);
798 	TASK_INIT(&V_pf_overloadtask, 0, pf_overload_task, curvnet);
799 	mtx_init(&pf_sendqueue_mtx, "pf send queue", NULL, MTX_DEF);
800 	mtx_init(&pf_overloadqueue_mtx, "pf overload/flush queue", NULL,
801 	    MTX_DEF);
802 
803 	/* Unlinked, but may be referenced rules. */
804 	TAILQ_INIT(&V_pf_unlinked_rules);
805 	mtx_init(&pf_unlnkdrules_mtx, "pf unlinked rules", NULL, MTX_DEF);
806 }
807 
808 void
pf_mtag_cleanup()809 pf_mtag_cleanup()
810 {
811 
812 	uma_zdestroy(pf_mtag_z);
813 }
814 
815 void
pf_cleanup()816 pf_cleanup()
817 {
818 	struct pf_keyhash	*kh;
819 	struct pf_idhash	*ih;
820 	struct pf_srchash	*sh;
821 	struct pf_send_entry	*pfse, *next;
822 	u_int i;
823 
824 	for (i = 0, kh = V_pf_keyhash, ih = V_pf_idhash; i <= pf_hashmask;
825 	    i++, kh++, ih++) {
826 		KASSERT(LIST_EMPTY(&kh->keys), ("%s: key hash not empty",
827 		    __func__));
828 		KASSERT(LIST_EMPTY(&ih->states), ("%s: id hash not empty",
829 		    __func__));
830 		mtx_destroy(&kh->lock);
831 		mtx_destroy(&ih->lock);
832 	}
833 	free(V_pf_keyhash, M_PFHASH);
834 	free(V_pf_idhash, M_PFHASH);
835 
836 	for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++) {
837 		KASSERT(LIST_EMPTY(&sh->nodes),
838 		    ("%s: source node hash not empty", __func__));
839 		mtx_destroy(&sh->lock);
840 	}
841 	free(V_pf_srchash, M_PFHASH);
842 
843 	STAILQ_FOREACH_SAFE(pfse, &V_pf_sendqueue, pfse_next, next) {
844 		m_freem(pfse->pfse_m);
845 		free(pfse, M_PFTEMP);
846 	}
847 
848 	mtx_destroy(&pf_sendqueue_mtx);
849 	mtx_destroy(&pf_overloadqueue_mtx);
850 	mtx_destroy(&pf_unlnkdrules_mtx);
851 
852 	uma_zdestroy(V_pf_sources_z);
853 	uma_zdestroy(V_pf_state_z);
854 	uma_zdestroy(V_pf_state_key_z);
855 }
856 
857 static int
pf_mtag_uminit(void * mem,int size,int how)858 pf_mtag_uminit(void *mem, int size, int how)
859 {
860 	struct m_tag *t;
861 
862 	t = (struct m_tag *)mem;
863 	t->m_tag_cookie = MTAG_ABI_COMPAT;
864 	t->m_tag_id = PACKET_TAG_PF;
865 	t->m_tag_len = sizeof(struct pf_mtag);
866 	t->m_tag_free = pf_mtag_free;
867 
868 	return (0);
869 }
870 
871 static void
pf_mtag_free(struct m_tag * t)872 pf_mtag_free(struct m_tag *t)
873 {
874 
875 	uma_zfree(pf_mtag_z, t);
876 }
877 
878 struct pf_mtag *
pf_get_mtag(struct mbuf * m)879 pf_get_mtag(struct mbuf *m)
880 {
881 	struct m_tag *mtag;
882 
883 	if ((mtag = m_tag_find(m, PACKET_TAG_PF, NULL)) != NULL)
884 		return ((struct pf_mtag *)(mtag + 1));
885 
886 	mtag = uma_zalloc(pf_mtag_z, M_NOWAIT);
887 	if (mtag == NULL)
888 		return (NULL);
889 	bzero(mtag + 1, sizeof(struct pf_mtag));
890 	m_tag_prepend(m, mtag);
891 
892 	return ((struct pf_mtag *)(mtag + 1));
893 }
894 
895 static int
pf_state_key_attach(struct pf_state_key * skw,struct pf_state_key * sks,struct pf_state * s)896 pf_state_key_attach(struct pf_state_key *skw, struct pf_state_key *sks,
897     struct pf_state *s)
898 {
899 	struct pf_keyhash	*khs, *khw, *kh;
900 	struct pf_state_key	*sk, *cur;
901 	struct pf_state		*si, *olds = NULL;
902 	int idx;
903 
904 	KASSERT(s->refs == 0, ("%s: state not pristine", __func__));
905 	KASSERT(s->key[PF_SK_WIRE] == NULL, ("%s: state has key", __func__));
906 	KASSERT(s->key[PF_SK_STACK] == NULL, ("%s: state has key", __func__));
907 
908 	/*
909 	 * We need to lock hash slots of both keys. To avoid deadlock
910 	 * we always lock the slot with lower address first. Unlock order
911 	 * isn't important.
912 	 *
913 	 * We also need to lock ID hash slot before dropping key
914 	 * locks. On success we return with ID hash slot locked.
915 	 */
916 
917 	if (skw == sks) {
918 		khs = khw = &V_pf_keyhash[pf_hashkey(skw)];
919 		PF_HASHROW_LOCK(khs);
920 	} else {
921 		khs = &V_pf_keyhash[pf_hashkey(sks)];
922 		khw = &V_pf_keyhash[pf_hashkey(skw)];
923 		if (khs == khw) {
924 			PF_HASHROW_LOCK(khs);
925 		} else if (khs < khw) {
926 			PF_HASHROW_LOCK(khs);
927 			PF_HASHROW_LOCK(khw);
928 		} else {
929 			PF_HASHROW_LOCK(khw);
930 			PF_HASHROW_LOCK(khs);
931 		}
932 	}
933 
934 #define	KEYS_UNLOCK()	do {			\
935 	if (khs != khw) {			\
936 		PF_HASHROW_UNLOCK(khs);		\
937 		PF_HASHROW_UNLOCK(khw);		\
938 	} else					\
939 		PF_HASHROW_UNLOCK(khs);		\
940 } while (0)
941 
942 	/*
943 	 * First run: start with wire key.
944 	 */
945 	sk = skw;
946 	kh = khw;
947 	idx = PF_SK_WIRE;
948 
949 keyattach:
950 	LIST_FOREACH(cur, &kh->keys, entry)
951 		if (bcmp(cur, sk, sizeof(struct pf_state_key_cmp)) == 0)
952 			break;
953 
954 	if (cur != NULL) {
955 		/* Key exists. Check for same kif, if none, add to key. */
956 		TAILQ_FOREACH(si, &cur->states[idx], key_list[idx]) {
957 			struct pf_idhash *ih = &V_pf_idhash[PF_IDHASH(si)];
958 
959 			PF_HASHROW_LOCK(ih);
960 			if (si->kif == s->kif &&
961 			    si->direction == s->direction) {
962 				if (sk->proto == IPPROTO_TCP &&
963 				    si->src.state >= TCPS_FIN_WAIT_2 &&
964 				    si->dst.state >= TCPS_FIN_WAIT_2) {
965 					/*
966 					 * New state matches an old >FIN_WAIT_2
967 					 * state. We can't drop key hash locks,
968 					 * thus we can't unlink it properly.
969 					 *
970 					 * As a workaround we drop it into
971 					 * TCPS_CLOSED state, schedule purge
972 					 * ASAP and push it into the very end
973 					 * of the slot TAILQ, so that it won't
974 					 * conflict with our new state.
975 					 */
976 					si->src.state = si->dst.state =
977 					    TCPS_CLOSED;
978 					si->timeout = PFTM_PURGE;
979 					olds = si;
980 				} else {
981 					if (V_pf_status.debug >= PF_DEBUG_MISC) {
982 						printf("pf: %s key attach "
983 						    "failed on %s: ",
984 						    (idx == PF_SK_WIRE) ?
985 						    "wire" : "stack",
986 						    s->kif->pfik_name);
987 						pf_print_state_parts(s,
988 						    (idx == PF_SK_WIRE) ?
989 						    sk : NULL,
990 						    (idx == PF_SK_STACK) ?
991 						    sk : NULL);
992 						printf(", existing: ");
993 						pf_print_state_parts(si,
994 						    (idx == PF_SK_WIRE) ?
995 						    sk : NULL,
996 						    (idx == PF_SK_STACK) ?
997 						    sk : NULL);
998 						printf("\n");
999 					}
1000 					PF_HASHROW_UNLOCK(ih);
1001 					KEYS_UNLOCK();
1002 					uma_zfree(V_pf_state_key_z, sk);
1003 					if (idx == PF_SK_STACK)
1004 						pf_detach_state(s);
1005 					return (EEXIST); /* collision! */
1006 				}
1007 			}
1008 			PF_HASHROW_UNLOCK(ih);
1009 		}
1010 		uma_zfree(V_pf_state_key_z, sk);
1011 		s->key[idx] = cur;
1012 	} else {
1013 		LIST_INSERT_HEAD(&kh->keys, sk, entry);
1014 		s->key[idx] = sk;
1015 	}
1016 
1017 stateattach:
1018 	/* List is sorted, if-bound states before floating. */
1019 	if (s->kif == V_pfi_all)
1020 		TAILQ_INSERT_TAIL(&s->key[idx]->states[idx], s, key_list[idx]);
1021 	else
1022 		TAILQ_INSERT_HEAD(&s->key[idx]->states[idx], s, key_list[idx]);
1023 
1024 	if (olds) {
1025 		TAILQ_REMOVE(&s->key[idx]->states[idx], olds, key_list[idx]);
1026 		TAILQ_INSERT_TAIL(&s->key[idx]->states[idx], olds,
1027 		    key_list[idx]);
1028 		olds = NULL;
1029 	}
1030 
1031 	/*
1032 	 * Attach done. See how should we (or should not?)
1033 	 * attach a second key.
1034 	 */
1035 	if (sks == skw) {
1036 		s->key[PF_SK_STACK] = s->key[PF_SK_WIRE];
1037 		idx = PF_SK_STACK;
1038 		sks = NULL;
1039 		goto stateattach;
1040 	} else if (sks != NULL) {
1041 		/*
1042 		 * Continue attaching with stack key.
1043 		 */
1044 		sk = sks;
1045 		kh = khs;
1046 		idx = PF_SK_STACK;
1047 		sks = NULL;
1048 		goto keyattach;
1049 	}
1050 
1051 	PF_STATE_LOCK(s);
1052 	KEYS_UNLOCK();
1053 
1054 	KASSERT(s->key[PF_SK_WIRE] != NULL && s->key[PF_SK_STACK] != NULL,
1055 	    ("%s failure", __func__));
1056 
1057 	return (0);
1058 #undef	KEYS_UNLOCK
1059 }
1060 
1061 static void
pf_detach_state(struct pf_state * s)1062 pf_detach_state(struct pf_state *s)
1063 {
1064 	struct pf_state_key *sks = s->key[PF_SK_STACK];
1065 	struct pf_keyhash *kh;
1066 
1067 	if (sks != NULL) {
1068 		kh = &V_pf_keyhash[pf_hashkey(sks)];
1069 		PF_HASHROW_LOCK(kh);
1070 		if (s->key[PF_SK_STACK] != NULL)
1071 			pf_state_key_detach(s, PF_SK_STACK);
1072 		/*
1073 		 * If both point to same key, then we are done.
1074 		 */
1075 		if (sks == s->key[PF_SK_WIRE]) {
1076 			pf_state_key_detach(s, PF_SK_WIRE);
1077 			PF_HASHROW_UNLOCK(kh);
1078 			return;
1079 		}
1080 		PF_HASHROW_UNLOCK(kh);
1081 	}
1082 
1083 	if (s->key[PF_SK_WIRE] != NULL) {
1084 		kh = &V_pf_keyhash[pf_hashkey(s->key[PF_SK_WIRE])];
1085 		PF_HASHROW_LOCK(kh);
1086 		if (s->key[PF_SK_WIRE] != NULL)
1087 			pf_state_key_detach(s, PF_SK_WIRE);
1088 		PF_HASHROW_UNLOCK(kh);
1089 	}
1090 }
1091 
1092 static void
pf_state_key_detach(struct pf_state * s,int idx)1093 pf_state_key_detach(struct pf_state *s, int idx)
1094 {
1095 	struct pf_state_key *sk = s->key[idx];
1096 #ifdef INVARIANTS
1097 	struct pf_keyhash *kh = &V_pf_keyhash[pf_hashkey(sk)];
1098 
1099 	PF_HASHROW_ASSERT(kh);
1100 #endif
1101 	TAILQ_REMOVE(&sk->states[idx], s, key_list[idx]);
1102 	s->key[idx] = NULL;
1103 
1104 	if (TAILQ_EMPTY(&sk->states[0]) && TAILQ_EMPTY(&sk->states[1])) {
1105 		LIST_REMOVE(sk, entry);
1106 		uma_zfree(V_pf_state_key_z, sk);
1107 	}
1108 }
1109 
1110 static int
pf_state_key_ctor(void * mem,int size,void * arg,int flags)1111 pf_state_key_ctor(void *mem, int size, void *arg, int flags)
1112 {
1113 	struct pf_state_key *sk = mem;
1114 
1115 	bzero(sk, sizeof(struct pf_state_key_cmp));
1116 	TAILQ_INIT(&sk->states[PF_SK_WIRE]);
1117 	TAILQ_INIT(&sk->states[PF_SK_STACK]);
1118 
1119 	return (0);
1120 }
1121 
1122 struct pf_state_key *
pf_state_key_setup(struct pf_pdesc * pd,struct pf_addr * saddr,struct pf_addr * daddr,u_int16_t sport,u_int16_t dport)1123 pf_state_key_setup(struct pf_pdesc *pd, struct pf_addr *saddr,
1124 	struct pf_addr *daddr, u_int16_t sport, u_int16_t dport)
1125 {
1126 	struct pf_state_key *sk;
1127 
1128 	sk = uma_zalloc(V_pf_state_key_z, M_NOWAIT);
1129 	if (sk == NULL)
1130 		return (NULL);
1131 
1132 	PF_ACPY(&sk->addr[pd->sidx], saddr, pd->af);
1133 	PF_ACPY(&sk->addr[pd->didx], daddr, pd->af);
1134 	sk->port[pd->sidx] = sport;
1135 	sk->port[pd->didx] = dport;
1136 	sk->proto = pd->proto;
1137 	sk->af = pd->af;
1138 
1139 	return (sk);
1140 }
1141 
1142 struct pf_state_key *
pf_state_key_clone(struct pf_state_key * orig)1143 pf_state_key_clone(struct pf_state_key *orig)
1144 {
1145 	struct pf_state_key *sk;
1146 
1147 	sk = uma_zalloc(V_pf_state_key_z, M_NOWAIT);
1148 	if (sk == NULL)
1149 		return (NULL);
1150 
1151 	bcopy(orig, sk, sizeof(struct pf_state_key_cmp));
1152 
1153 	return (sk);
1154 }
1155 
1156 int
pf_state_insert(struct pfi_kif * kif,struct pf_state_key * skw,struct pf_state_key * sks,struct pf_state * s)1157 pf_state_insert(struct pfi_kif *kif, struct pf_state_key *skw,
1158     struct pf_state_key *sks, struct pf_state *s)
1159 {
1160 	struct pf_idhash *ih;
1161 	struct pf_state *cur;
1162 	int error;
1163 
1164 	KASSERT(TAILQ_EMPTY(&sks->states[0]) && TAILQ_EMPTY(&sks->states[1]),
1165 	    ("%s: sks not pristine", __func__));
1166 	KASSERT(TAILQ_EMPTY(&skw->states[0]) && TAILQ_EMPTY(&skw->states[1]),
1167 	    ("%s: skw not pristine", __func__));
1168 	KASSERT(s->refs == 0, ("%s: state not pristine", __func__));
1169 
1170 	s->kif = kif;
1171 
1172 	if (s->id == 0 && s->creatorid == 0) {
1173 		/* XXX: should be atomic, but probability of collision low */
1174 		if ((s->id = V_pf_stateid[curcpu]++) == PFID_MAXID)
1175 			V_pf_stateid[curcpu] = 1;
1176 		s->id |= (uint64_t )curcpu << PFID_CPUSHIFT;
1177 		s->id = htobe64(s->id);
1178 		s->creatorid = V_pf_status.hostid;
1179 	}
1180 
1181 	/* Returns with ID locked on success. */
1182 	if ((error = pf_state_key_attach(skw, sks, s)) != 0)
1183 		return (error);
1184 
1185 	ih = &V_pf_idhash[PF_IDHASH(s)];
1186 	PF_HASHROW_ASSERT(ih);
1187 	LIST_FOREACH(cur, &ih->states, entry)
1188 		if (cur->id == s->id && cur->creatorid == s->creatorid)
1189 			break;
1190 
1191 	if (cur != NULL) {
1192 		PF_HASHROW_UNLOCK(ih);
1193 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
1194 			printf("pf: state ID collision: "
1195 			    "id: %016llx creatorid: %08x\n",
1196 			    (unsigned long long)be64toh(s->id),
1197 			    ntohl(s->creatorid));
1198 		}
1199 		pf_detach_state(s);
1200 		return (EEXIST);
1201 	}
1202 	LIST_INSERT_HEAD(&ih->states, s, entry);
1203 	/* One for keys, one for ID hash. */
1204 	refcount_init(&s->refs, 2);
1205 
1206 	counter_u64_add(V_pf_status.fcounters[FCNT_STATE_INSERT], 1);
1207 	if (pfsync_insert_state_ptr != NULL)
1208 		pfsync_insert_state_ptr(s);
1209 
1210 	/* Returns locked. */
1211 	return (0);
1212 }
1213 
1214 /*
1215  * Find state by ID: returns with locked row on success.
1216  */
1217 struct pf_state *
pf_find_state_byid(uint64_t id,uint32_t creatorid)1218 pf_find_state_byid(uint64_t id, uint32_t creatorid)
1219 {
1220 	struct pf_idhash *ih;
1221 	struct pf_state *s;
1222 
1223 	counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
1224 
1225 	ih = &V_pf_idhash[(be64toh(id) % (pf_hashmask + 1))];
1226 
1227 	PF_HASHROW_LOCK(ih);
1228 	LIST_FOREACH(s, &ih->states, entry)
1229 		if (s->id == id && s->creatorid == creatorid)
1230 			break;
1231 
1232 	if (s == NULL)
1233 		PF_HASHROW_UNLOCK(ih);
1234 
1235 	return (s);
1236 }
1237 
1238 /*
1239  * Find state by key.
1240  * Returns with ID hash slot locked on success.
1241  */
1242 static struct pf_state *
pf_find_state(struct pfi_kif * kif,struct pf_state_key_cmp * key,u_int dir)1243 pf_find_state(struct pfi_kif *kif, struct pf_state_key_cmp *key, u_int dir)
1244 {
1245 	struct pf_keyhash	*kh;
1246 	struct pf_state_key	*sk;
1247 	struct pf_state		*s;
1248 	int idx;
1249 
1250 	counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
1251 
1252 	kh = &V_pf_keyhash[pf_hashkey((struct pf_state_key *)key)];
1253 
1254 	PF_HASHROW_LOCK(kh);
1255 	LIST_FOREACH(sk, &kh->keys, entry)
1256 		if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
1257 			break;
1258 	if (sk == NULL) {
1259 		PF_HASHROW_UNLOCK(kh);
1260 		return (NULL);
1261 	}
1262 
1263 	idx = (dir == PF_IN ? PF_SK_WIRE : PF_SK_STACK);
1264 
1265 	/* List is sorted, if-bound states before floating ones. */
1266 	TAILQ_FOREACH(s, &sk->states[idx], key_list[idx])
1267 		if (s->kif == V_pfi_all || s->kif == kif) {
1268 			PF_STATE_LOCK(s);
1269 			PF_HASHROW_UNLOCK(kh);
1270 			if (s->timeout >= PFTM_MAX) {
1271 				/*
1272 				 * State is either being processed by
1273 				 * pf_unlink_state() in an other thread, or
1274 				 * is scheduled for immediate expiry.
1275 				 */
1276 				PF_STATE_UNLOCK(s);
1277 				return (NULL);
1278 			}
1279 			return (s);
1280 		}
1281 	PF_HASHROW_UNLOCK(kh);
1282 
1283 	return (NULL);
1284 }
1285 
1286 struct pf_state *
pf_find_state_all(struct pf_state_key_cmp * key,u_int dir,int * more)1287 pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more)
1288 {
1289 	struct pf_keyhash	*kh;
1290 	struct pf_state_key	*sk;
1291 	struct pf_state		*s, *ret = NULL;
1292 	int			 idx, inout = 0;
1293 
1294 	counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
1295 
1296 	kh = &V_pf_keyhash[pf_hashkey((struct pf_state_key *)key)];
1297 
1298 	PF_HASHROW_LOCK(kh);
1299 	LIST_FOREACH(sk, &kh->keys, entry)
1300 		if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
1301 			break;
1302 	if (sk == NULL) {
1303 		PF_HASHROW_UNLOCK(kh);
1304 		return (NULL);
1305 	}
1306 	switch (dir) {
1307 	case PF_IN:
1308 		idx = PF_SK_WIRE;
1309 		break;
1310 	case PF_OUT:
1311 		idx = PF_SK_STACK;
1312 		break;
1313 	case PF_INOUT:
1314 		idx = PF_SK_WIRE;
1315 		inout = 1;
1316 		break;
1317 	default:
1318 		panic("%s: dir %u", __func__, dir);
1319 	}
1320 second_run:
1321 	TAILQ_FOREACH(s, &sk->states[idx], key_list[idx]) {
1322 		if (more == NULL) {
1323 			PF_HASHROW_UNLOCK(kh);
1324 			return (s);
1325 		}
1326 
1327 		if (ret)
1328 			(*more)++;
1329 		else
1330 			ret = s;
1331 	}
1332 	if (inout == 1) {
1333 		inout = 0;
1334 		idx = PF_SK_STACK;
1335 		goto second_run;
1336 	}
1337 	PF_HASHROW_UNLOCK(kh);
1338 
1339 	return (ret);
1340 }
1341 
1342 /* END state table stuff */
1343 
1344 static void
pf_send(struct pf_send_entry * pfse)1345 pf_send(struct pf_send_entry *pfse)
1346 {
1347 
1348 	PF_SENDQ_LOCK();
1349 	STAILQ_INSERT_TAIL(&V_pf_sendqueue, pfse, pfse_next);
1350 	PF_SENDQ_UNLOCK();
1351 	swi_sched(V_pf_swi_cookie, 0);
1352 }
1353 
1354 void
pf_intr(void * v)1355 pf_intr(void *v)
1356 {
1357 	struct pf_send_head queue;
1358 	struct pf_send_entry *pfse, *next;
1359 
1360 	CURVNET_SET((struct vnet *)v);
1361 
1362 	PF_SENDQ_LOCK();
1363 	queue = V_pf_sendqueue;
1364 	STAILQ_INIT(&V_pf_sendqueue);
1365 	PF_SENDQ_UNLOCK();
1366 
1367 	STAILQ_FOREACH_SAFE(pfse, &queue, pfse_next, next) {
1368 		switch (pfse->pfse_type) {
1369 #ifdef INET
1370 		case PFSE_IP:
1371 			ip_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL);
1372 			break;
1373 		case PFSE_ICMP:
1374 			icmp_error(pfse->pfse_m, pfse->pfse_icmp_type,
1375 			    pfse->pfse_icmp_code, 0, pfse->pfse_icmp_mtu);
1376 			break;
1377 #endif /* INET */
1378 #ifdef INET6
1379 		case PFSE_IP6:
1380 			ip6_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL,
1381 			    NULL);
1382 			break;
1383 		case PFSE_ICMP6:
1384 			icmp6_error(pfse->pfse_m, pfse->pfse_icmp_type,
1385 			    pfse->pfse_icmp_code, pfse->pfse_icmp_mtu);
1386 			break;
1387 #endif /* INET6 */
1388 		default:
1389 			panic("%s: unknown type", __func__);
1390 		}
1391 		free(pfse, M_PFTEMP);
1392 	}
1393 	CURVNET_RESTORE();
1394 }
1395 
1396 void
pf_purge_thread(void * v)1397 pf_purge_thread(void *v)
1398 {
1399 	u_int idx = 0;
1400 
1401 	CURVNET_SET((struct vnet *)v);
1402 
1403 	for (;;) {
1404 		PF_RULES_RLOCK();
1405 		rw_sleep(pf_purge_thread, &pf_rules_lock, 0, "pftm", hz / 10);
1406 
1407 		if (V_pf_end_threads) {
1408 			/*
1409 			 * To cleanse up all kifs and rules we need
1410 			 * two runs: first one clears reference flags,
1411 			 * then pf_purge_expired_states() doesn't
1412 			 * raise them, and then second run frees.
1413 			 */
1414 			PF_RULES_RUNLOCK();
1415 			pf_purge_unlinked_rules();
1416 			pfi_kif_purge();
1417 
1418 			/*
1419 			 * Now purge everything.
1420 			 */
1421 			pf_purge_expired_states(0, pf_hashmask);
1422 			pf_purge_expired_fragments();
1423 			pf_purge_expired_src_nodes();
1424 
1425 			/*
1426 			 * Now all kifs & rules should be unreferenced,
1427 			 * thus should be successfully freed.
1428 			 */
1429 			pf_purge_unlinked_rules();
1430 			pfi_kif_purge();
1431 
1432 			/*
1433 			 * Announce success and exit.
1434 			 */
1435 			PF_RULES_RLOCK();
1436 			V_pf_end_threads++;
1437 			PF_RULES_RUNLOCK();
1438 			wakeup(pf_purge_thread);
1439 			kproc_exit(0);
1440 		}
1441 		PF_RULES_RUNLOCK();
1442 
1443 		/* Process 1/interval fraction of the state table every run. */
1444 		idx = pf_purge_expired_states(idx, pf_hashmask /
1445 			    (V_pf_default_rule.timeout[PFTM_INTERVAL] * 10));
1446 
1447 		/* Purge other expired types every PFTM_INTERVAL seconds. */
1448 		if (idx == 0) {
1449 			/*
1450 			 * Order is important:
1451 			 * - states and src nodes reference rules
1452 			 * - states and rules reference kifs
1453 			 */
1454 			pf_purge_expired_fragments();
1455 			pf_purge_expired_src_nodes();
1456 			pf_purge_unlinked_rules();
1457 			pfi_kif_purge();
1458 		}
1459 	}
1460 	/* not reached */
1461 	CURVNET_RESTORE();
1462 }
1463 
1464 u_int32_t
pf_state_expires(const struct pf_state * state)1465 pf_state_expires(const struct pf_state *state)
1466 {
1467 	u_int32_t	timeout;
1468 	u_int32_t	start;
1469 	u_int32_t	end;
1470 	u_int32_t	states;
1471 
1472 	/* handle all PFTM_* > PFTM_MAX here */
1473 	if (state->timeout == PFTM_PURGE)
1474 		return (time_uptime);
1475 	KASSERT(state->timeout != PFTM_UNLINKED,
1476 	    ("pf_state_expires: timeout == PFTM_UNLINKED"));
1477 	KASSERT((state->timeout < PFTM_MAX),
1478 	    ("pf_state_expires: timeout > PFTM_MAX"));
1479 	timeout = state->rule.ptr->timeout[state->timeout];
1480 	if (!timeout)
1481 		timeout = V_pf_default_rule.timeout[state->timeout];
1482 	start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START];
1483 	if (start) {
1484 		end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END];
1485 		states = counter_u64_fetch(state->rule.ptr->states_cur);
1486 	} else {
1487 		start = V_pf_default_rule.timeout[PFTM_ADAPTIVE_START];
1488 		end = V_pf_default_rule.timeout[PFTM_ADAPTIVE_END];
1489 		states = V_pf_status.states;
1490 	}
1491 	if (end && states > start && start < end) {
1492 		if (states < end)
1493 			return (state->expire + timeout * (end - states) /
1494 			    (end - start));
1495 		else
1496 			return (time_uptime);
1497 	}
1498 	return (state->expire + timeout);
1499 }
1500 
1501 void
pf_purge_expired_src_nodes()1502 pf_purge_expired_src_nodes()
1503 {
1504 	struct pf_src_node_list	 freelist;
1505 	struct pf_srchash	*sh;
1506 	struct pf_src_node	*cur, *next;
1507 	int i;
1508 
1509 	LIST_INIT(&freelist);
1510 	for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++) {
1511 	    PF_HASHROW_LOCK(sh);
1512 	    LIST_FOREACH_SAFE(cur, &sh->nodes, entry, next)
1513 		if (cur->states == 0 && cur->expire <= time_uptime) {
1514 			pf_unlink_src_node_locked(cur);
1515 			LIST_INSERT_HEAD(&freelist, cur, entry);
1516 		} else if (cur->rule.ptr != NULL)
1517 			cur->rule.ptr->rule_flag |= PFRULE_REFS;
1518 	    PF_HASHROW_UNLOCK(sh);
1519 	}
1520 
1521 	pf_free_src_nodes(&freelist);
1522 
1523 	V_pf_status.src_nodes = uma_zone_get_cur(V_pf_sources_z);
1524 }
1525 
1526 static void
pf_src_tree_remove_state(struct pf_state * s)1527 pf_src_tree_remove_state(struct pf_state *s)
1528 {
1529 	u_int32_t timeout;
1530 
1531 	if (s->src_node != NULL) {
1532 		if (s->src.tcp_est)
1533 			--s->src_node->conn;
1534 		if (--s->src_node->states == 0) {
1535 			timeout = s->rule.ptr->timeout[PFTM_SRC_NODE];
1536 			if (!timeout)
1537 				timeout =
1538 				    V_pf_default_rule.timeout[PFTM_SRC_NODE];
1539 			s->src_node->expire = time_uptime + timeout;
1540 		}
1541 	}
1542 	if (s->nat_src_node != s->src_node && s->nat_src_node != NULL) {
1543 		if (--s->nat_src_node->states == 0) {
1544 			timeout = s->rule.ptr->timeout[PFTM_SRC_NODE];
1545 			if (!timeout)
1546 				timeout =
1547 				    V_pf_default_rule.timeout[PFTM_SRC_NODE];
1548 			s->nat_src_node->expire = time_uptime + timeout;
1549 		}
1550 	}
1551 	s->src_node = s->nat_src_node = NULL;
1552 }
1553 
1554 /*
1555  * Unlink and potentilly free a state. Function may be
1556  * called with ID hash row locked, but always returns
1557  * unlocked, since it needs to go through key hash locking.
1558  */
1559 int
pf_unlink_state(struct pf_state * s,u_int flags)1560 pf_unlink_state(struct pf_state *s, u_int flags)
1561 {
1562 	struct pf_idhash *ih = &V_pf_idhash[PF_IDHASH(s)];
1563 
1564 	if ((flags & PF_ENTER_LOCKED) == 0)
1565 		PF_HASHROW_LOCK(ih);
1566 	else
1567 		PF_HASHROW_ASSERT(ih);
1568 
1569 	if (s->timeout == PFTM_UNLINKED) {
1570 		/*
1571 		 * State is being processed
1572 		 * by pf_unlink_state() in
1573 		 * an other thread.
1574 		 */
1575 		PF_HASHROW_UNLOCK(ih);
1576 		return (0);	/* XXXGL: undefined actually */
1577 	}
1578 
1579 	if (s->src.state == PF_TCPS_PROXY_DST) {
1580 		/* XXX wire key the right one? */
1581 		pf_send_tcp(NULL, s->rule.ptr, s->key[PF_SK_WIRE]->af,
1582 		    &s->key[PF_SK_WIRE]->addr[1],
1583 		    &s->key[PF_SK_WIRE]->addr[0],
1584 		    s->key[PF_SK_WIRE]->port[1],
1585 		    s->key[PF_SK_WIRE]->port[0],
1586 		    s->src.seqhi, s->src.seqlo + 1,
1587 		    TH_RST|TH_ACK, 0, 0, 0, 1, s->tag, NULL);
1588 	}
1589 
1590 	LIST_REMOVE(s, entry);
1591 	pf_src_tree_remove_state(s);
1592 
1593 	if (pfsync_delete_state_ptr != NULL)
1594 		pfsync_delete_state_ptr(s);
1595 
1596 	STATE_DEC_COUNTERS(s);
1597 
1598 	s->timeout = PFTM_UNLINKED;
1599 
1600 	PF_HASHROW_UNLOCK(ih);
1601 
1602 	pf_detach_state(s);
1603 	refcount_release(&s->refs);
1604 
1605 	return (pf_release_state(s));
1606 }
1607 
1608 void
pf_free_state(struct pf_state * cur)1609 pf_free_state(struct pf_state *cur)
1610 {
1611 
1612 	KASSERT(cur->refs == 0, ("%s: %p has refs", __func__, cur));
1613 	KASSERT(cur->timeout == PFTM_UNLINKED, ("%s: timeout %u", __func__,
1614 	    cur->timeout));
1615 
1616 	pf_normalize_tcp_cleanup(cur);
1617 	uma_zfree(V_pf_state_z, cur);
1618 	counter_u64_add(V_pf_status.fcounters[FCNT_STATE_REMOVALS], 1);
1619 }
1620 
1621 /*
1622  * Called only from pf_purge_thread(), thus serialized.
1623  */
1624 static u_int
pf_purge_expired_states(u_int i,int maxcheck)1625 pf_purge_expired_states(u_int i, int maxcheck)
1626 {
1627 	struct pf_idhash *ih;
1628 	struct pf_state *s;
1629 
1630 	V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
1631 
1632 	/*
1633 	 * Go through hash and unlink states that expire now.
1634 	 */
1635 	while (maxcheck > 0) {
1636 
1637 		ih = &V_pf_idhash[i];
1638 relock:
1639 		PF_HASHROW_LOCK(ih);
1640 		LIST_FOREACH(s, &ih->states, entry) {
1641 			if (pf_state_expires(s) <= time_uptime) {
1642 				V_pf_status.states -=
1643 				    pf_unlink_state(s, PF_ENTER_LOCKED);
1644 				goto relock;
1645 			}
1646 			s->rule.ptr->rule_flag |= PFRULE_REFS;
1647 			if (s->nat_rule.ptr != NULL)
1648 				s->nat_rule.ptr->rule_flag |= PFRULE_REFS;
1649 			if (s->anchor.ptr != NULL)
1650 				s->anchor.ptr->rule_flag |= PFRULE_REFS;
1651 			s->kif->pfik_flags |= PFI_IFLAG_REFS;
1652 			if (s->rt_kif)
1653 				s->rt_kif->pfik_flags |= PFI_IFLAG_REFS;
1654 		}
1655 		PF_HASHROW_UNLOCK(ih);
1656 
1657 		/* Return when we hit end of hash. */
1658 		if (++i > pf_hashmask) {
1659 			V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
1660 			return (0);
1661 		}
1662 
1663 		maxcheck--;
1664 	}
1665 
1666 	V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
1667 
1668 	return (i);
1669 }
1670 
1671 static void
pf_purge_unlinked_rules()1672 pf_purge_unlinked_rules()
1673 {
1674 	struct pf_rulequeue tmpq;
1675 	struct pf_rule *r, *r1;
1676 
1677 	/*
1678 	 * If we have overloading task pending, then we'd
1679 	 * better skip purging this time. There is a tiny
1680 	 * probability that overloading task references
1681 	 * an already unlinked rule.
1682 	 */
1683 	PF_OVERLOADQ_LOCK();
1684 	if (!SLIST_EMPTY(&V_pf_overloadqueue)) {
1685 		PF_OVERLOADQ_UNLOCK();
1686 		return;
1687 	}
1688 	PF_OVERLOADQ_UNLOCK();
1689 
1690 	/*
1691 	 * Do naive mark-and-sweep garbage collecting of old rules.
1692 	 * Reference flag is raised by pf_purge_expired_states()
1693 	 * and pf_purge_expired_src_nodes().
1694 	 *
1695 	 * To avoid LOR between PF_UNLNKDRULES_LOCK/PF_RULES_WLOCK,
1696 	 * use a temporary queue.
1697 	 */
1698 	TAILQ_INIT(&tmpq);
1699 	PF_UNLNKDRULES_LOCK();
1700 	TAILQ_FOREACH_SAFE(r, &V_pf_unlinked_rules, entries, r1) {
1701 		if (!(r->rule_flag & PFRULE_REFS)) {
1702 			TAILQ_REMOVE(&V_pf_unlinked_rules, r, entries);
1703 			TAILQ_INSERT_TAIL(&tmpq, r, entries);
1704 		} else
1705 			r->rule_flag &= ~PFRULE_REFS;
1706 	}
1707 	PF_UNLNKDRULES_UNLOCK();
1708 
1709 	if (!TAILQ_EMPTY(&tmpq)) {
1710 		PF_RULES_WLOCK();
1711 		TAILQ_FOREACH_SAFE(r, &tmpq, entries, r1) {
1712 			TAILQ_REMOVE(&tmpq, r, entries);
1713 			pf_free_rule(r);
1714 		}
1715 		PF_RULES_WUNLOCK();
1716 	}
1717 }
1718 
1719 void
pf_print_host(struct pf_addr * addr,u_int16_t p,sa_family_t af)1720 pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af)
1721 {
1722 	switch (af) {
1723 #ifdef INET
1724 	case AF_INET: {
1725 		u_int32_t a = ntohl(addr->addr32[0]);
1726 		printf("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255,
1727 		    (a>>8)&255, a&255);
1728 		if (p) {
1729 			p = ntohs(p);
1730 			printf(":%u", p);
1731 		}
1732 		break;
1733 	}
1734 #endif /* INET */
1735 #ifdef INET6
1736 	case AF_INET6: {
1737 		u_int16_t b;
1738 		u_int8_t i, curstart, curend, maxstart, maxend;
1739 		curstart = curend = maxstart = maxend = 255;
1740 		for (i = 0; i < 8; i++) {
1741 			if (!addr->addr16[i]) {
1742 				if (curstart == 255)
1743 					curstart = i;
1744 				curend = i;
1745 			} else {
1746 				if ((curend - curstart) >
1747 				    (maxend - maxstart)) {
1748 					maxstart = curstart;
1749 					maxend = curend;
1750 				}
1751 				curstart = curend = 255;
1752 			}
1753 		}
1754 		if ((curend - curstart) >
1755 		    (maxend - maxstart)) {
1756 			maxstart = curstart;
1757 			maxend = curend;
1758 		}
1759 		for (i = 0; i < 8; i++) {
1760 			if (i >= maxstart && i <= maxend) {
1761 				if (i == 0)
1762 					printf(":");
1763 				if (i == maxend)
1764 					printf(":");
1765 			} else {
1766 				b = ntohs(addr->addr16[i]);
1767 				printf("%x", b);
1768 				if (i < 7)
1769 					printf(":");
1770 			}
1771 		}
1772 		if (p) {
1773 			p = ntohs(p);
1774 			printf("[%u]", p);
1775 		}
1776 		break;
1777 	}
1778 #endif /* INET6 */
1779 	}
1780 }
1781 
1782 void
pf_print_state(struct pf_state * s)1783 pf_print_state(struct pf_state *s)
1784 {
1785 	pf_print_state_parts(s, NULL, NULL);
1786 }
1787 
1788 static void
pf_print_state_parts(struct pf_state * s,struct pf_state_key * skwp,struct pf_state_key * sksp)1789 pf_print_state_parts(struct pf_state *s,
1790     struct pf_state_key *skwp, struct pf_state_key *sksp)
1791 {
1792 	struct pf_state_key *skw, *sks;
1793 	u_int8_t proto, dir;
1794 
1795 	/* Do our best to fill these, but they're skipped if NULL */
1796 	skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL);
1797 	sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL);
1798 	proto = skw ? skw->proto : (sks ? sks->proto : 0);
1799 	dir = s ? s->direction : 0;
1800 
1801 	switch (proto) {
1802 	case IPPROTO_IPV4:
1803 		printf("IPv4");
1804 		break;
1805 	case IPPROTO_IPV6:
1806 		printf("IPv6");
1807 		break;
1808 	case IPPROTO_TCP:
1809 		printf("TCP");
1810 		break;
1811 	case IPPROTO_UDP:
1812 		printf("UDP");
1813 		break;
1814 	case IPPROTO_ICMP:
1815 		printf("ICMP");
1816 		break;
1817 	case IPPROTO_ICMPV6:
1818 		printf("ICMPv6");
1819 		break;
1820 	default:
1821 		printf("%u", skw->proto);
1822 		break;
1823 	}
1824 	switch (dir) {
1825 	case PF_IN:
1826 		printf(" in");
1827 		break;
1828 	case PF_OUT:
1829 		printf(" out");
1830 		break;
1831 	}
1832 	if (skw) {
1833 		printf(" wire: ");
1834 		pf_print_host(&skw->addr[0], skw->port[0], skw->af);
1835 		printf(" ");
1836 		pf_print_host(&skw->addr[1], skw->port[1], skw->af);
1837 	}
1838 	if (sks) {
1839 		printf(" stack: ");
1840 		if (sks != skw) {
1841 			pf_print_host(&sks->addr[0], sks->port[0], sks->af);
1842 			printf(" ");
1843 			pf_print_host(&sks->addr[1], sks->port[1], sks->af);
1844 		} else
1845 			printf("-");
1846 	}
1847 	if (s) {
1848 		if (proto == IPPROTO_TCP) {
1849 			printf(" [lo=%u high=%u win=%u modulator=%u",
1850 			    s->src.seqlo, s->src.seqhi,
1851 			    s->src.max_win, s->src.seqdiff);
1852 			if (s->src.wscale && s->dst.wscale)
1853 				printf(" wscale=%u",
1854 				    s->src.wscale & PF_WSCALE_MASK);
1855 			printf("]");
1856 			printf(" [lo=%u high=%u win=%u modulator=%u",
1857 			    s->dst.seqlo, s->dst.seqhi,
1858 			    s->dst.max_win, s->dst.seqdiff);
1859 			if (s->src.wscale && s->dst.wscale)
1860 				printf(" wscale=%u",
1861 				s->dst.wscale & PF_WSCALE_MASK);
1862 			printf("]");
1863 		}
1864 		printf(" %u:%u", s->src.state, s->dst.state);
1865 	}
1866 }
1867 
1868 void
pf_print_flags(u_int8_t f)1869 pf_print_flags(u_int8_t f)
1870 {
1871 	if (f)
1872 		printf(" ");
1873 	if (f & TH_FIN)
1874 		printf("F");
1875 	if (f & TH_SYN)
1876 		printf("S");
1877 	if (f & TH_RST)
1878 		printf("R");
1879 	if (f & TH_PUSH)
1880 		printf("P");
1881 	if (f & TH_ACK)
1882 		printf("A");
1883 	if (f & TH_URG)
1884 		printf("U");
1885 	if (f & TH_ECE)
1886 		printf("E");
1887 	if (f & TH_CWR)
1888 		printf("W");
1889 }
1890 
1891 #define	PF_SET_SKIP_STEPS(i)					\
1892 	do {							\
1893 		while (head[i] != cur) {			\
1894 			head[i]->skip[i].ptr = cur;		\
1895 			head[i] = TAILQ_NEXT(head[i], entries);	\
1896 		}						\
1897 	} while (0)
1898 
1899 void
pf_calc_skip_steps(struct pf_rulequeue * rules)1900 pf_calc_skip_steps(struct pf_rulequeue *rules)
1901 {
1902 	struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT];
1903 	int i;
1904 
1905 	cur = TAILQ_FIRST(rules);
1906 	prev = cur;
1907 	for (i = 0; i < PF_SKIP_COUNT; ++i)
1908 		head[i] = cur;
1909 	while (cur != NULL) {
1910 
1911 		if (cur->kif != prev->kif || cur->ifnot != prev->ifnot)
1912 			PF_SET_SKIP_STEPS(PF_SKIP_IFP);
1913 		if (cur->direction != prev->direction)
1914 			PF_SET_SKIP_STEPS(PF_SKIP_DIR);
1915 		if (cur->af != prev->af)
1916 			PF_SET_SKIP_STEPS(PF_SKIP_AF);
1917 		if (cur->proto != prev->proto)
1918 			PF_SET_SKIP_STEPS(PF_SKIP_PROTO);
1919 		if (cur->src.neg != prev->src.neg ||
1920 		    pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr))
1921 			PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR);
1922 		if (cur->src.port[0] != prev->src.port[0] ||
1923 		    cur->src.port[1] != prev->src.port[1] ||
1924 		    cur->src.port_op != prev->src.port_op)
1925 			PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT);
1926 		if (cur->dst.neg != prev->dst.neg ||
1927 		    pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr))
1928 			PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR);
1929 		if (cur->dst.port[0] != prev->dst.port[0] ||
1930 		    cur->dst.port[1] != prev->dst.port[1] ||
1931 		    cur->dst.port_op != prev->dst.port_op)
1932 			PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT);
1933 
1934 		prev = cur;
1935 		cur = TAILQ_NEXT(cur, entries);
1936 	}
1937 	for (i = 0; i < PF_SKIP_COUNT; ++i)
1938 		PF_SET_SKIP_STEPS(i);
1939 }
1940 
1941 static int
pf_addr_wrap_neq(struct pf_addr_wrap * aw1,struct pf_addr_wrap * aw2)1942 pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2)
1943 {
1944 	if (aw1->type != aw2->type)
1945 		return (1);
1946 	switch (aw1->type) {
1947 	case PF_ADDR_ADDRMASK:
1948 	case PF_ADDR_RANGE:
1949 		if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, 0))
1950 			return (1);
1951 		if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, 0))
1952 			return (1);
1953 		return (0);
1954 	case PF_ADDR_DYNIFTL:
1955 		return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt);
1956 	case PF_ADDR_NOROUTE:
1957 	case PF_ADDR_URPFFAILED:
1958 		return (0);
1959 	case PF_ADDR_TABLE:
1960 		return (aw1->p.tbl != aw2->p.tbl);
1961 	default:
1962 		printf("invalid address type: %d\n", aw1->type);
1963 		return (1);
1964 	}
1965 }
1966 
1967 u_int16_t
pf_cksum_fixup(u_int16_t cksum,u_int16_t old,u_int16_t new,u_int8_t udp)1968 pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp)
1969 {
1970 	u_int32_t	l;
1971 
1972 	if (udp && !cksum)
1973 		return (0x0000);
1974 	l = cksum + old - new;
1975 	l = (l >> 16) + (l & 65535);
1976 	l = l & 65535;
1977 	if (udp && !l)
1978 		return (0xFFFF);
1979 	return (l);
1980 }
1981 
1982 static void
pf_change_ap(struct pf_addr * a,u_int16_t * p,u_int16_t * ic,u_int16_t * pc,struct pf_addr * an,u_int16_t pn,u_int8_t u,sa_family_t af)1983 pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
1984     struct pf_addr *an, u_int16_t pn, u_int8_t u, sa_family_t af)
1985 {
1986 	struct pf_addr	ao;
1987 	u_int16_t	po = *p;
1988 
1989 	PF_ACPY(&ao, a, af);
1990 	PF_ACPY(a, an, af);
1991 
1992 	*p = pn;
1993 
1994 	switch (af) {
1995 #ifdef INET
1996 	case AF_INET:
1997 		*ic = pf_cksum_fixup(pf_cksum_fixup(*ic,
1998 		    ao.addr16[0], an->addr16[0], 0),
1999 		    ao.addr16[1], an->addr16[1], 0);
2000 		*p = pn;
2001 		*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
2002 		    ao.addr16[0], an->addr16[0], u),
2003 		    ao.addr16[1], an->addr16[1], u),
2004 		    po, pn, u);
2005 		break;
2006 #endif /* INET */
2007 #ifdef INET6
2008 	case AF_INET6:
2009 		*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2010 		    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2011 		    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
2012 		    ao.addr16[0], an->addr16[0], u),
2013 		    ao.addr16[1], an->addr16[1], u),
2014 		    ao.addr16[2], an->addr16[2], u),
2015 		    ao.addr16[3], an->addr16[3], u),
2016 		    ao.addr16[4], an->addr16[4], u),
2017 		    ao.addr16[5], an->addr16[5], u),
2018 		    ao.addr16[6], an->addr16[6], u),
2019 		    ao.addr16[7], an->addr16[7], u),
2020 		    po, pn, u);
2021 		break;
2022 #endif /* INET6 */
2023 	}
2024 }
2025 
2026 
2027 /* Changes a u_int32_t.  Uses a void * so there are no align restrictions */
2028 void
pf_change_a(void * a,u_int16_t * c,u_int32_t an,u_int8_t u)2029 pf_change_a(void *a, u_int16_t *c, u_int32_t an, u_int8_t u)
2030 {
2031 	u_int32_t	ao;
2032 
2033 	memcpy(&ao, a, sizeof(ao));
2034 	memcpy(a, &an, sizeof(u_int32_t));
2035 	*c = pf_cksum_fixup(pf_cksum_fixup(*c, ao / 65536, an / 65536, u),
2036 	    ao % 65536, an % 65536, u);
2037 }
2038 
2039 #ifdef INET6
2040 static void
pf_change_a6(struct pf_addr * a,u_int16_t * c,struct pf_addr * an,u_int8_t u)2041 pf_change_a6(struct pf_addr *a, u_int16_t *c, struct pf_addr *an, u_int8_t u)
2042 {
2043 	struct pf_addr	ao;
2044 
2045 	PF_ACPY(&ao, a, AF_INET6);
2046 	PF_ACPY(a, an, AF_INET6);
2047 
2048 	*c = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2049 	    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2050 	    pf_cksum_fixup(pf_cksum_fixup(*c,
2051 	    ao.addr16[0], an->addr16[0], u),
2052 	    ao.addr16[1], an->addr16[1], u),
2053 	    ao.addr16[2], an->addr16[2], u),
2054 	    ao.addr16[3], an->addr16[3], u),
2055 	    ao.addr16[4], an->addr16[4], u),
2056 	    ao.addr16[5], an->addr16[5], u),
2057 	    ao.addr16[6], an->addr16[6], u),
2058 	    ao.addr16[7], an->addr16[7], u);
2059 }
2060 #endif /* INET6 */
2061 
2062 static void
pf_change_icmp(struct pf_addr * ia,u_int16_t * ip,struct pf_addr * oa,struct pf_addr * na,u_int16_t np,u_int16_t * pc,u_int16_t * h2c,u_int16_t * ic,u_int16_t * hc,u_int8_t u,sa_family_t af)2063 pf_change_icmp(struct pf_addr *ia, u_int16_t *ip, struct pf_addr *oa,
2064     struct pf_addr *na, u_int16_t np, u_int16_t *pc, u_int16_t *h2c,
2065     u_int16_t *ic, u_int16_t *hc, u_int8_t u, sa_family_t af)
2066 {
2067 	struct pf_addr	oia, ooa;
2068 
2069 	PF_ACPY(&oia, ia, af);
2070 	if (oa)
2071 		PF_ACPY(&ooa, oa, af);
2072 
2073 	/* Change inner protocol port, fix inner protocol checksum. */
2074 	if (ip != NULL) {
2075 		u_int16_t	oip = *ip;
2076 		u_int32_t	opc;
2077 
2078 		if (pc != NULL)
2079 			opc = *pc;
2080 		*ip = np;
2081 		if (pc != NULL)
2082 			*pc = pf_cksum_fixup(*pc, oip, *ip, u);
2083 		*ic = pf_cksum_fixup(*ic, oip, *ip, 0);
2084 		if (pc != NULL)
2085 			*ic = pf_cksum_fixup(*ic, opc, *pc, 0);
2086 	}
2087 	/* Change inner ip address, fix inner ip and icmp checksums. */
2088 	PF_ACPY(ia, na, af);
2089 	switch (af) {
2090 #ifdef INET
2091 	case AF_INET: {
2092 		u_int32_t	 oh2c = *h2c;
2093 
2094 		*h2c = pf_cksum_fixup(pf_cksum_fixup(*h2c,
2095 		    oia.addr16[0], ia->addr16[0], 0),
2096 		    oia.addr16[1], ia->addr16[1], 0);
2097 		*ic = pf_cksum_fixup(pf_cksum_fixup(*ic,
2098 		    oia.addr16[0], ia->addr16[0], 0),
2099 		    oia.addr16[1], ia->addr16[1], 0);
2100 		*ic = pf_cksum_fixup(*ic, oh2c, *h2c, 0);
2101 		break;
2102 	}
2103 #endif /* INET */
2104 #ifdef INET6
2105 	case AF_INET6:
2106 		*ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2107 		    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2108 		    pf_cksum_fixup(pf_cksum_fixup(*ic,
2109 		    oia.addr16[0], ia->addr16[0], u),
2110 		    oia.addr16[1], ia->addr16[1], u),
2111 		    oia.addr16[2], ia->addr16[2], u),
2112 		    oia.addr16[3], ia->addr16[3], u),
2113 		    oia.addr16[4], ia->addr16[4], u),
2114 		    oia.addr16[5], ia->addr16[5], u),
2115 		    oia.addr16[6], ia->addr16[6], u),
2116 		    oia.addr16[7], ia->addr16[7], u);
2117 		break;
2118 #endif /* INET6 */
2119 	}
2120 	/* Outer ip address, fix outer ip or icmpv6 checksum, if necessary. */
2121 	if (oa) {
2122 		PF_ACPY(oa, na, af);
2123 		switch (af) {
2124 #ifdef INET
2125 		case AF_INET:
2126 			*hc = pf_cksum_fixup(pf_cksum_fixup(*hc,
2127 			    ooa.addr16[0], oa->addr16[0], 0),
2128 			    ooa.addr16[1], oa->addr16[1], 0);
2129 			break;
2130 #endif /* INET */
2131 #ifdef INET6
2132 		case AF_INET6:
2133 			*ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2134 			    pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
2135 			    pf_cksum_fixup(pf_cksum_fixup(*ic,
2136 			    ooa.addr16[0], oa->addr16[0], u),
2137 			    ooa.addr16[1], oa->addr16[1], u),
2138 			    ooa.addr16[2], oa->addr16[2], u),
2139 			    ooa.addr16[3], oa->addr16[3], u),
2140 			    ooa.addr16[4], oa->addr16[4], u),
2141 			    ooa.addr16[5], oa->addr16[5], u),
2142 			    ooa.addr16[6], oa->addr16[6], u),
2143 			    ooa.addr16[7], oa->addr16[7], u);
2144 			break;
2145 #endif /* INET6 */
2146 		}
2147 	}
2148 }
2149 
2150 
2151 /*
2152  * Need to modulate the sequence numbers in the TCP SACK option
2153  * (credits to Krzysztof Pfaff for report and patch)
2154  */
2155 static int
pf_modulate_sack(struct mbuf * m,int off,struct pf_pdesc * pd,struct tcphdr * th,struct pf_state_peer * dst)2156 pf_modulate_sack(struct mbuf *m, int off, struct pf_pdesc *pd,
2157     struct tcphdr *th, struct pf_state_peer *dst)
2158 {
2159 	int hlen = (th->th_off << 2) - sizeof(*th), thoptlen = hlen;
2160 	u_int8_t opts[TCP_MAXOLEN], *opt = opts;
2161 	int copyback = 0, i, olen;
2162 	struct sackblk sack;
2163 
2164 #define	TCPOLEN_SACKLEN	(TCPOLEN_SACK + 2)
2165 	if (hlen < TCPOLEN_SACKLEN ||
2166 	    !pf_pull_hdr(m, off + sizeof(*th), opts, hlen, NULL, NULL, pd->af))
2167 		return 0;
2168 
2169 	while (hlen >= TCPOLEN_SACKLEN) {
2170 		olen = opt[1];
2171 		switch (*opt) {
2172 		case TCPOPT_EOL:	/* FALLTHROUGH */
2173 		case TCPOPT_NOP:
2174 			opt++;
2175 			hlen--;
2176 			break;
2177 		case TCPOPT_SACK:
2178 			if (olen > hlen)
2179 				olen = hlen;
2180 			if (olen >= TCPOLEN_SACKLEN) {
2181 				for (i = 2; i + TCPOLEN_SACK <= olen;
2182 				    i += TCPOLEN_SACK) {
2183 					memcpy(&sack, &opt[i], sizeof(sack));
2184 					pf_change_a(&sack.start, &th->th_sum,
2185 					    htonl(ntohl(sack.start) -
2186 					    dst->seqdiff), 0);
2187 					pf_change_a(&sack.end, &th->th_sum,
2188 					    htonl(ntohl(sack.end) -
2189 					    dst->seqdiff), 0);
2190 					memcpy(&opt[i], &sack, sizeof(sack));
2191 				}
2192 				copyback = 1;
2193 			}
2194 			/* FALLTHROUGH */
2195 		default:
2196 			if (olen < 2)
2197 				olen = 2;
2198 			hlen -= olen;
2199 			opt += olen;
2200 		}
2201 	}
2202 
2203 	if (copyback)
2204 		m_copyback(m, off + sizeof(*th), thoptlen, (caddr_t)opts);
2205 	return (copyback);
2206 }
2207 
2208 static void
pf_send_tcp(struct mbuf * replyto,const struct pf_rule * r,sa_family_t af,const struct pf_addr * saddr,const struct pf_addr * daddr,u_int16_t sport,u_int16_t dport,u_int32_t seq,u_int32_t ack,u_int8_t flags,u_int16_t win,u_int16_t mss,u_int8_t ttl,int tag,u_int16_t rtag,struct ifnet * ifp)2209 pf_send_tcp(struct mbuf *replyto, const struct pf_rule *r, sa_family_t af,
2210     const struct pf_addr *saddr, const struct pf_addr *daddr,
2211     u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
2212     u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
2213     u_int16_t rtag, struct ifnet *ifp)
2214 {
2215 	struct pf_send_entry *pfse;
2216 	struct mbuf	*m;
2217 	int		 len, tlen;
2218 #ifdef INET
2219 	struct ip	*h = NULL;
2220 #endif /* INET */
2221 #ifdef INET6
2222 	struct ip6_hdr	*h6 = NULL;
2223 #endif /* INET6 */
2224 	struct tcphdr	*th;
2225 	char		*opt;
2226 	struct pf_mtag  *pf_mtag;
2227 
2228 	len = 0;
2229 	th = NULL;
2230 
2231 	/* maximum segment size tcp option */
2232 	tlen = sizeof(struct tcphdr);
2233 	if (mss)
2234 		tlen += 4;
2235 
2236 	switch (af) {
2237 #ifdef INET
2238 	case AF_INET:
2239 		len = sizeof(struct ip) + tlen;
2240 		break;
2241 #endif /* INET */
2242 #ifdef INET6
2243 	case AF_INET6:
2244 		len = sizeof(struct ip6_hdr) + tlen;
2245 		break;
2246 #endif /* INET6 */
2247 	default:
2248 		panic("%s: unsupported af %d", __func__, af);
2249 	}
2250 
2251 	/* Allocate outgoing queue entry, mbuf and mbuf tag. */
2252 	pfse = malloc(sizeof(*pfse), M_PFTEMP, M_NOWAIT);
2253 	if (pfse == NULL)
2254 		return;
2255 	m = m_gethdr(M_NOWAIT, MT_DATA);
2256 	if (m == NULL) {
2257 		free(pfse, M_PFTEMP);
2258 		return;
2259 	}
2260 #ifdef MAC
2261 	mac_netinet_firewall_send(m);
2262 #endif
2263 	if ((pf_mtag = pf_get_mtag(m)) == NULL) {
2264 		free(pfse, M_PFTEMP);
2265 		m_freem(m);
2266 		return;
2267 	}
2268 	if (tag)
2269 		m->m_flags |= M_SKIP_FIREWALL;
2270 	pf_mtag->tag = rtag;
2271 
2272 	if (r != NULL && r->rtableid >= 0)
2273 		M_SETFIB(m, r->rtableid);
2274 
2275 #ifdef ALTQ
2276 	if (r != NULL && r->qid) {
2277 		pf_mtag->qid = r->qid;
2278 
2279 		/* add hints for ecn */
2280 		pf_mtag->hdr = mtod(m, struct ip *);
2281 	}
2282 #endif /* ALTQ */
2283 	m->m_data += max_linkhdr;
2284 	m->m_pkthdr.len = m->m_len = len;
2285 	m->m_pkthdr.rcvif = NULL;
2286 	bzero(m->m_data, len);
2287 	switch (af) {
2288 #ifdef INET
2289 	case AF_INET:
2290 		h = mtod(m, struct ip *);
2291 
2292 		/* IP header fields included in the TCP checksum */
2293 		h->ip_p = IPPROTO_TCP;
2294 		h->ip_len = htons(tlen);
2295 		h->ip_src.s_addr = saddr->v4.s_addr;
2296 		h->ip_dst.s_addr = daddr->v4.s_addr;
2297 
2298 		th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip));
2299 		break;
2300 #endif /* INET */
2301 #ifdef INET6
2302 	case AF_INET6:
2303 		h6 = mtod(m, struct ip6_hdr *);
2304 
2305 		/* IP header fields included in the TCP checksum */
2306 		h6->ip6_nxt = IPPROTO_TCP;
2307 		h6->ip6_plen = htons(tlen);
2308 		memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr));
2309 		memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr));
2310 
2311 		th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr));
2312 		break;
2313 #endif /* INET6 */
2314 	}
2315 
2316 	/* TCP header */
2317 	th->th_sport = sport;
2318 	th->th_dport = dport;
2319 	th->th_seq = htonl(seq);
2320 	th->th_ack = htonl(ack);
2321 	th->th_off = tlen >> 2;
2322 	th->th_flags = flags;
2323 	th->th_win = htons(win);
2324 
2325 	if (mss) {
2326 		opt = (char *)(th + 1);
2327 		opt[0] = TCPOPT_MAXSEG;
2328 		opt[1] = 4;
2329 		HTONS(mss);
2330 		bcopy((caddr_t)&mss, (caddr_t)(opt + 2), 2);
2331 	}
2332 
2333 	switch (af) {
2334 #ifdef INET
2335 	case AF_INET:
2336 		/* TCP checksum */
2337 		th->th_sum = in_cksum(m, len);
2338 
2339 		/* Finish the IP header */
2340 		h->ip_v = 4;
2341 		h->ip_hl = sizeof(*h) >> 2;
2342 		h->ip_tos = IPTOS_LOWDELAY;
2343 		h->ip_off = htons(V_path_mtu_discovery ? IP_DF : 0);
2344 		h->ip_len = htons(len);
2345 		h->ip_ttl = ttl ? ttl : V_ip_defttl;
2346 		h->ip_sum = 0;
2347 
2348 		pfse->pfse_type = PFSE_IP;
2349 		break;
2350 #endif /* INET */
2351 #ifdef INET6
2352 	case AF_INET6:
2353 		/* TCP checksum */
2354 		th->th_sum = in6_cksum(m, IPPROTO_TCP,
2355 		    sizeof(struct ip6_hdr), tlen);
2356 
2357 		h6->ip6_vfc |= IPV6_VERSION;
2358 		h6->ip6_hlim = IPV6_DEFHLIM;
2359 
2360 		pfse->pfse_type = PFSE_IP6;
2361 		break;
2362 #endif /* INET6 */
2363 	}
2364 	pfse->pfse_m = m;
2365 	pf_send(pfse);
2366 }
2367 
2368 static void
pf_send_icmp(struct mbuf * m,u_int8_t type,u_int8_t code,sa_family_t af,struct pf_rule * r)2369 pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af,
2370     struct pf_rule *r)
2371 {
2372 	struct pf_send_entry *pfse;
2373 	struct mbuf *m0;
2374 	struct pf_mtag *pf_mtag;
2375 
2376 	/* Allocate outgoing queue entry, mbuf and mbuf tag. */
2377 	pfse = malloc(sizeof(*pfse), M_PFTEMP, M_NOWAIT);
2378 	if (pfse == NULL)
2379 		return;
2380 
2381 	if ((m0 = m_copypacket(m, M_NOWAIT)) == NULL) {
2382 		free(pfse, M_PFTEMP);
2383 		return;
2384 	}
2385 
2386 	if ((pf_mtag = pf_get_mtag(m0)) == NULL) {
2387 		free(pfse, M_PFTEMP);
2388 		return;
2389 	}
2390 	/* XXX: revisit */
2391 	m0->m_flags |= M_SKIP_FIREWALL;
2392 
2393 	if (r->rtableid >= 0)
2394 		M_SETFIB(m0, r->rtableid);
2395 
2396 #ifdef ALTQ
2397 	if (r->qid) {
2398 		pf_mtag->qid = r->qid;
2399 		/* add hints for ecn */
2400 		pf_mtag->hdr = mtod(m0, struct ip *);
2401 	}
2402 #endif /* ALTQ */
2403 
2404 	switch (af) {
2405 #ifdef INET
2406 	case AF_INET:
2407 		pfse->pfse_type = PFSE_ICMP;
2408 		break;
2409 #endif /* INET */
2410 #ifdef INET6
2411 	case AF_INET6:
2412 		pfse->pfse_type = PFSE_ICMP6;
2413 		break;
2414 #endif /* INET6 */
2415 	}
2416 	pfse->pfse_m = m0;
2417 	pfse->pfse_icmp_type = type;
2418 	pfse->pfse_icmp_code = code;
2419 	pf_send(pfse);
2420 }
2421 
2422 /*
2423  * Return 1 if the addresses a and b match (with mask m), otherwise return 0.
2424  * If n is 0, they match if they are equal. If n is != 0, they match if they
2425  * are different.
2426  */
2427 int
pf_match_addr(u_int8_t n,struct pf_addr * a,struct pf_addr * m,struct pf_addr * b,sa_family_t af)2428 pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m,
2429     struct pf_addr *b, sa_family_t af)
2430 {
2431 	int	match = 0;
2432 
2433 	switch (af) {
2434 #ifdef INET
2435 	case AF_INET:
2436 		if ((a->addr32[0] & m->addr32[0]) ==
2437 		    (b->addr32[0] & m->addr32[0]))
2438 			match++;
2439 		break;
2440 #endif /* INET */
2441 #ifdef INET6
2442 	case AF_INET6:
2443 		if (((a->addr32[0] & m->addr32[0]) ==
2444 		     (b->addr32[0] & m->addr32[0])) &&
2445 		    ((a->addr32[1] & m->addr32[1]) ==
2446 		     (b->addr32[1] & m->addr32[1])) &&
2447 		    ((a->addr32[2] & m->addr32[2]) ==
2448 		     (b->addr32[2] & m->addr32[2])) &&
2449 		    ((a->addr32[3] & m->addr32[3]) ==
2450 		     (b->addr32[3] & m->addr32[3])))
2451 			match++;
2452 		break;
2453 #endif /* INET6 */
2454 	}
2455 	if (match) {
2456 		if (n)
2457 			return (0);
2458 		else
2459 			return (1);
2460 	} else {
2461 		if (n)
2462 			return (1);
2463 		else
2464 			return (0);
2465 	}
2466 }
2467 
2468 /*
2469  * Return 1 if b <= a <= e, otherwise return 0.
2470  */
2471 int
pf_match_addr_range(struct pf_addr * b,struct pf_addr * e,struct pf_addr * a,sa_family_t af)2472 pf_match_addr_range(struct pf_addr *b, struct pf_addr *e,
2473     struct pf_addr *a, sa_family_t af)
2474 {
2475 	switch (af) {
2476 #ifdef INET
2477 	case AF_INET:
2478 		if ((a->addr32[0] < b->addr32[0]) ||
2479 		    (a->addr32[0] > e->addr32[0]))
2480 			return (0);
2481 		break;
2482 #endif /* INET */
2483 #ifdef INET6
2484 	case AF_INET6: {
2485 		int	i;
2486 
2487 		/* check a >= b */
2488 		for (i = 0; i < 4; ++i)
2489 			if (a->addr32[i] > b->addr32[i])
2490 				break;
2491 			else if (a->addr32[i] < b->addr32[i])
2492 				return (0);
2493 		/* check a <= e */
2494 		for (i = 0; i < 4; ++i)
2495 			if (a->addr32[i] < e->addr32[i])
2496 				break;
2497 			else if (a->addr32[i] > e->addr32[i])
2498 				return (0);
2499 		break;
2500 	}
2501 #endif /* INET6 */
2502 	}
2503 	return (1);
2504 }
2505 
2506 static int
pf_match(u_int8_t op,u_int32_t a1,u_int32_t a2,u_int32_t p)2507 pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p)
2508 {
2509 	switch (op) {
2510 	case PF_OP_IRG:
2511 		return ((p > a1) && (p < a2));
2512 	case PF_OP_XRG:
2513 		return ((p < a1) || (p > a2));
2514 	case PF_OP_RRG:
2515 		return ((p >= a1) && (p <= a2));
2516 	case PF_OP_EQ:
2517 		return (p == a1);
2518 	case PF_OP_NE:
2519 		return (p != a1);
2520 	case PF_OP_LT:
2521 		return (p < a1);
2522 	case PF_OP_LE:
2523 		return (p <= a1);
2524 	case PF_OP_GT:
2525 		return (p > a1);
2526 	case PF_OP_GE:
2527 		return (p >= a1);
2528 	}
2529 	return (0); /* never reached */
2530 }
2531 
2532 int
pf_match_port(u_int8_t op,u_int16_t a1,u_int16_t a2,u_int16_t p)2533 pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p)
2534 {
2535 	NTOHS(a1);
2536 	NTOHS(a2);
2537 	NTOHS(p);
2538 	return (pf_match(op, a1, a2, p));
2539 }
2540 
2541 static int
pf_match_uid(u_int8_t op,uid_t a1,uid_t a2,uid_t u)2542 pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u)
2543 {
2544 	if (u == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE)
2545 		return (0);
2546 	return (pf_match(op, a1, a2, u));
2547 }
2548 
2549 static int
pf_match_gid(u_int8_t op,gid_t a1,gid_t a2,gid_t g)2550 pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g)
2551 {
2552 	if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE)
2553 		return (0);
2554 	return (pf_match(op, a1, a2, g));
2555 }
2556 
2557 int
pf_match_tag(struct mbuf * m,struct pf_rule * r,int * tag,int mtag)2558 pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag, int mtag)
2559 {
2560 	if (*tag == -1)
2561 		*tag = mtag;
2562 
2563 	return ((!r->match_tag_not && r->match_tag == *tag) ||
2564 	    (r->match_tag_not && r->match_tag != *tag));
2565 }
2566 
2567 int
pf_tag_packet(struct mbuf * m,struct pf_pdesc * pd,int tag)2568 pf_tag_packet(struct mbuf *m, struct pf_pdesc *pd, int tag)
2569 {
2570 
2571 	KASSERT(tag > 0, ("%s: tag %d", __func__, tag));
2572 
2573 	if (pd->pf_mtag == NULL && ((pd->pf_mtag = pf_get_mtag(m)) == NULL))
2574 		return (ENOMEM);
2575 
2576 	pd->pf_mtag->tag = tag;
2577 
2578 	return (0);
2579 }
2580 
2581 #define	PF_ANCHOR_STACKSIZE	32
2582 struct pf_anchor_stackframe {
2583 	struct pf_ruleset	*rs;
2584 	struct pf_rule		*r;	/* XXX: + match bit */
2585 	struct pf_anchor	*child;
2586 };
2587 
2588 /*
2589  * XXX: We rely on malloc(9) returning pointer aligned addresses.
2590  */
2591 #define	PF_ANCHORSTACK_MATCH	0x00000001
2592 #define	PF_ANCHORSTACK_MASK	(PF_ANCHORSTACK_MATCH)
2593 
2594 #define	PF_ANCHOR_MATCH(f)	((uintptr_t)(f)->r & PF_ANCHORSTACK_MATCH)
2595 #define	PF_ANCHOR_RULE(f)	(struct pf_rule *)			\
2596 				((uintptr_t)(f)->r & ~PF_ANCHORSTACK_MASK)
2597 #define	PF_ANCHOR_SET_MATCH(f)	do { (f)->r = (void *) 			\
2598 				((uintptr_t)(f)->r | PF_ANCHORSTACK_MATCH);  \
2599 } while (0)
2600 
2601 void
pf_step_into_anchor(struct pf_anchor_stackframe * stack,int * depth,struct pf_ruleset ** rs,int n,struct pf_rule ** r,struct pf_rule ** a,int * match)2602 pf_step_into_anchor(struct pf_anchor_stackframe *stack, int *depth,
2603     struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a,
2604     int *match)
2605 {
2606 	struct pf_anchor_stackframe	*f;
2607 
2608 	PF_RULES_RASSERT();
2609 
2610 	if (match)
2611 		*match = 0;
2612 	if (*depth >= PF_ANCHOR_STACKSIZE) {
2613 		printf("%s: anchor stack overflow on %s\n",
2614 		    __func__, (*r)->anchor->name);
2615 		*r = TAILQ_NEXT(*r, entries);
2616 		return;
2617 	} else if (*depth == 0 && a != NULL)
2618 		*a = *r;
2619 	f = stack + (*depth)++;
2620 	f->rs = *rs;
2621 	f->r = *r;
2622 	if ((*r)->anchor_wildcard) {
2623 		struct pf_anchor_node *parent = &(*r)->anchor->children;
2624 
2625 		if ((f->child = RB_MIN(pf_anchor_node, parent)) == NULL) {
2626 			*r = NULL;
2627 			return;
2628 		}
2629 		*rs = &f->child->ruleset;
2630 	} else {
2631 		f->child = NULL;
2632 		*rs = &(*r)->anchor->ruleset;
2633 	}
2634 	*r = TAILQ_FIRST((*rs)->rules[n].active.ptr);
2635 }
2636 
2637 int
pf_step_out_of_anchor(struct pf_anchor_stackframe * stack,int * depth,struct pf_ruleset ** rs,int n,struct pf_rule ** r,struct pf_rule ** a,int * match)2638 pf_step_out_of_anchor(struct pf_anchor_stackframe *stack, int *depth,
2639     struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a,
2640     int *match)
2641 {
2642 	struct pf_anchor_stackframe	*f;
2643 	struct pf_rule *fr;
2644 	int quick = 0;
2645 
2646 	PF_RULES_RASSERT();
2647 
2648 	do {
2649 		if (*depth <= 0)
2650 			break;
2651 		f = stack + *depth - 1;
2652 		fr = PF_ANCHOR_RULE(f);
2653 		if (f->child != NULL) {
2654 			struct pf_anchor_node *parent;
2655 
2656 			/*
2657 			 * This block traverses through
2658 			 * a wildcard anchor.
2659 			 */
2660 			parent = &fr->anchor->children;
2661 			if (match != NULL && *match) {
2662 				/*
2663 				 * If any of "*" matched, then
2664 				 * "foo/ *" matched, mark frame
2665 				 * appropriately.
2666 				 */
2667 				PF_ANCHOR_SET_MATCH(f);
2668 				*match = 0;
2669 			}
2670 			f->child = RB_NEXT(pf_anchor_node, parent, f->child);
2671 			if (f->child != NULL) {
2672 				*rs = &f->child->ruleset;
2673 				*r = TAILQ_FIRST((*rs)->rules[n].active.ptr);
2674 				if (*r == NULL)
2675 					continue;
2676 				else
2677 					break;
2678 			}
2679 		}
2680 		(*depth)--;
2681 		if (*depth == 0 && a != NULL)
2682 			*a = NULL;
2683 		*rs = f->rs;
2684 		if (PF_ANCHOR_MATCH(f) || (match != NULL && *match))
2685 			quick = fr->quick;
2686 		*r = TAILQ_NEXT(fr, entries);
2687 	} while (*r == NULL);
2688 
2689 	return (quick);
2690 }
2691 
2692 #ifdef INET6
2693 void
pf_poolmask(struct pf_addr * naddr,struct pf_addr * raddr,struct pf_addr * rmask,struct pf_addr * saddr,sa_family_t af)2694 pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr,
2695     struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af)
2696 {
2697 	switch (af) {
2698 #ifdef INET
2699 	case AF_INET:
2700 		naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
2701 		((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
2702 		break;
2703 #endif /* INET */
2704 	case AF_INET6:
2705 		naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
2706 		((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
2707 		naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) |
2708 		((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]);
2709 		naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) |
2710 		((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]);
2711 		naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) |
2712 		((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]);
2713 		break;
2714 	}
2715 }
2716 
2717 void
pf_addr_inc(struct pf_addr * addr,sa_family_t af)2718 pf_addr_inc(struct pf_addr *addr, sa_family_t af)
2719 {
2720 	switch (af) {
2721 #ifdef INET
2722 	case AF_INET:
2723 		addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1);
2724 		break;
2725 #endif /* INET */
2726 	case AF_INET6:
2727 		if (addr->addr32[3] == 0xffffffff) {
2728 			addr->addr32[3] = 0;
2729 			if (addr->addr32[2] == 0xffffffff) {
2730 				addr->addr32[2] = 0;
2731 				if (addr->addr32[1] == 0xffffffff) {
2732 					addr->addr32[1] = 0;
2733 					addr->addr32[0] =
2734 					    htonl(ntohl(addr->addr32[0]) + 1);
2735 				} else
2736 					addr->addr32[1] =
2737 					    htonl(ntohl(addr->addr32[1]) + 1);
2738 			} else
2739 				addr->addr32[2] =
2740 				    htonl(ntohl(addr->addr32[2]) + 1);
2741 		} else
2742 			addr->addr32[3] =
2743 			    htonl(ntohl(addr->addr32[3]) + 1);
2744 		break;
2745 	}
2746 }
2747 #endif /* INET6 */
2748 
2749 int
pf_socket_lookup(int direction,struct pf_pdesc * pd,struct mbuf * m)2750 pf_socket_lookup(int direction, struct pf_pdesc *pd, struct mbuf *m)
2751 {
2752 	struct pf_addr		*saddr, *daddr;
2753 	u_int16_t		 sport, dport;
2754 	struct inpcbinfo	*pi;
2755 	struct inpcb		*inp;
2756 
2757 	pd->lookup.uid = UID_MAX;
2758 	pd->lookup.gid = GID_MAX;
2759 
2760 	switch (pd->proto) {
2761 	case IPPROTO_TCP:
2762 		if (pd->hdr.tcp == NULL)
2763 			return (-1);
2764 		sport = pd->hdr.tcp->th_sport;
2765 		dport = pd->hdr.tcp->th_dport;
2766 		pi = &V_tcbinfo;
2767 		break;
2768 	case IPPROTO_UDP:
2769 		if (pd->hdr.udp == NULL)
2770 			return (-1);
2771 		sport = pd->hdr.udp->uh_sport;
2772 		dport = pd->hdr.udp->uh_dport;
2773 		pi = &V_udbinfo;
2774 		break;
2775 	default:
2776 		return (-1);
2777 	}
2778 	if (direction == PF_IN) {
2779 		saddr = pd->src;
2780 		daddr = pd->dst;
2781 	} else {
2782 		u_int16_t	p;
2783 
2784 		p = sport;
2785 		sport = dport;
2786 		dport = p;
2787 		saddr = pd->dst;
2788 		daddr = pd->src;
2789 	}
2790 	switch (pd->af) {
2791 #ifdef INET
2792 	case AF_INET:
2793 		inp = in_pcblookup_mbuf(pi, saddr->v4, sport, daddr->v4,
2794 		    dport, INPLOOKUP_RLOCKPCB, NULL, m);
2795 		if (inp == NULL) {
2796 			inp = in_pcblookup_mbuf(pi, saddr->v4, sport,
2797 			   daddr->v4, dport, INPLOOKUP_WILDCARD |
2798 			   INPLOOKUP_RLOCKPCB, NULL, m);
2799 			if (inp == NULL)
2800 				return (-1);
2801 		}
2802 		break;
2803 #endif /* INET */
2804 #ifdef INET6
2805 	case AF_INET6:
2806 		inp = in6_pcblookup_mbuf(pi, &saddr->v6, sport, &daddr->v6,
2807 		    dport, INPLOOKUP_RLOCKPCB, NULL, m);
2808 		if (inp == NULL) {
2809 			inp = in6_pcblookup_mbuf(pi, &saddr->v6, sport,
2810 			    &daddr->v6, dport, INPLOOKUP_WILDCARD |
2811 			    INPLOOKUP_RLOCKPCB, NULL, m);
2812 			if (inp == NULL)
2813 				return (-1);
2814 		}
2815 		break;
2816 #endif /* INET6 */
2817 
2818 	default:
2819 		return (-1);
2820 	}
2821 	INP_RLOCK_ASSERT(inp);
2822 	pd->lookup.uid = inp->inp_cred->cr_uid;
2823 	pd->lookup.gid = inp->inp_cred->cr_groups[0];
2824 	INP_RUNLOCK(inp);
2825 
2826 	return (1);
2827 }
2828 
2829 static u_int8_t
pf_get_wscale(struct mbuf * m,int off,u_int16_t th_off,sa_family_t af)2830 pf_get_wscale(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af)
2831 {
2832 	int		 hlen;
2833 	u_int8_t	 hdr[60];
2834 	u_int8_t	*opt, optlen;
2835 	u_int8_t	 wscale = 0;
2836 
2837 	hlen = th_off << 2;		/* hlen <= sizeof(hdr) */
2838 	if (hlen <= sizeof(struct tcphdr))
2839 		return (0);
2840 	if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af))
2841 		return (0);
2842 	opt = hdr + sizeof(struct tcphdr);
2843 	hlen -= sizeof(struct tcphdr);
2844 	while (hlen >= 3) {
2845 		switch (*opt) {
2846 		case TCPOPT_EOL:
2847 		case TCPOPT_NOP:
2848 			++opt;
2849 			--hlen;
2850 			break;
2851 		case TCPOPT_WINDOW:
2852 			wscale = opt[2];
2853 			if (wscale > TCP_MAX_WINSHIFT)
2854 				wscale = TCP_MAX_WINSHIFT;
2855 			wscale |= PF_WSCALE_FLAG;
2856 			/* FALLTHROUGH */
2857 		default:
2858 			optlen = opt[1];
2859 			if (optlen < 2)
2860 				optlen = 2;
2861 			hlen -= optlen;
2862 			opt += optlen;
2863 			break;
2864 		}
2865 	}
2866 	return (wscale);
2867 }
2868 
2869 static u_int16_t
pf_get_mss(struct mbuf * m,int off,u_int16_t th_off,sa_family_t af)2870 pf_get_mss(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af)
2871 {
2872 	int		 hlen;
2873 	u_int8_t	 hdr[60];
2874 	u_int8_t	*opt, optlen;
2875 	u_int16_t	 mss = V_tcp_mssdflt;
2876 
2877 	hlen = th_off << 2;	/* hlen <= sizeof(hdr) */
2878 	if (hlen <= sizeof(struct tcphdr))
2879 		return (0);
2880 	if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af))
2881 		return (0);
2882 	opt = hdr + sizeof(struct tcphdr);
2883 	hlen -= sizeof(struct tcphdr);
2884 	while (hlen >= TCPOLEN_MAXSEG) {
2885 		switch (*opt) {
2886 		case TCPOPT_EOL:
2887 		case TCPOPT_NOP:
2888 			++opt;
2889 			--hlen;
2890 			break;
2891 		case TCPOPT_MAXSEG:
2892 			bcopy((caddr_t)(opt + 2), (caddr_t)&mss, 2);
2893 			NTOHS(mss);
2894 			/* FALLTHROUGH */
2895 		default:
2896 			optlen = opt[1];
2897 			if (optlen < 2)
2898 				optlen = 2;
2899 			hlen -= optlen;
2900 			opt += optlen;
2901 			break;
2902 		}
2903 	}
2904 	return (mss);
2905 }
2906 
2907 static u_int16_t
pf_calc_mss(struct pf_addr * addr,sa_family_t af,int rtableid,u_int16_t offer)2908 pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer)
2909 {
2910 #ifdef INET
2911 	struct sockaddr_in	*dst;
2912 	struct route		 ro;
2913 #endif /* INET */
2914 #ifdef INET6
2915 	struct sockaddr_in6	*dst6;
2916 	struct route_in6	 ro6;
2917 #endif /* INET6 */
2918 	struct rtentry		*rt = NULL;
2919 	int			 hlen = 0;
2920 	u_int16_t		 mss = V_tcp_mssdflt;
2921 
2922 	switch (af) {
2923 #ifdef INET
2924 	case AF_INET:
2925 		hlen = sizeof(struct ip);
2926 		bzero(&ro, sizeof(ro));
2927 		dst = (struct sockaddr_in *)&ro.ro_dst;
2928 		dst->sin_family = AF_INET;
2929 		dst->sin_len = sizeof(*dst);
2930 		dst->sin_addr = addr->v4;
2931 		in_rtalloc_ign(&ro, 0, rtableid);
2932 		rt = ro.ro_rt;
2933 		break;
2934 #endif /* INET */
2935 #ifdef INET6
2936 	case AF_INET6:
2937 		hlen = sizeof(struct ip6_hdr);
2938 		bzero(&ro6, sizeof(ro6));
2939 		dst6 = (struct sockaddr_in6 *)&ro6.ro_dst;
2940 		dst6->sin6_family = AF_INET6;
2941 		dst6->sin6_len = sizeof(*dst6);
2942 		dst6->sin6_addr = addr->v6;
2943 		in6_rtalloc_ign(&ro6, 0, rtableid);
2944 		rt = ro6.ro_rt;
2945 		break;
2946 #endif /* INET6 */
2947 	}
2948 
2949 	if (rt && rt->rt_ifp) {
2950 		mss = rt->rt_ifp->if_mtu - hlen - sizeof(struct tcphdr);
2951 		mss = max(V_tcp_mssdflt, mss);
2952 		RTFREE(rt);
2953 	}
2954 	mss = min(mss, offer);
2955 	mss = max(mss, 64);		/* sanity - at least max opt space */
2956 	return (mss);
2957 }
2958 
2959 static u_int32_t
pf_tcp_iss(struct pf_pdesc * pd)2960 pf_tcp_iss(struct pf_pdesc *pd)
2961 {
2962 	MD5_CTX ctx;
2963 	u_int32_t digest[4];
2964 
2965 	if (V_pf_tcp_secret_init == 0) {
2966 		read_random(&V_pf_tcp_secret, sizeof(V_pf_tcp_secret));
2967 		MD5Init(&V_pf_tcp_secret_ctx);
2968 		MD5Update(&V_pf_tcp_secret_ctx, V_pf_tcp_secret,
2969 		    sizeof(V_pf_tcp_secret));
2970 		V_pf_tcp_secret_init = 1;
2971 	}
2972 
2973 	ctx = V_pf_tcp_secret_ctx;
2974 
2975 	MD5Update(&ctx, (char *)&pd->hdr.tcp->th_sport, sizeof(u_short));
2976 	MD5Update(&ctx, (char *)&pd->hdr.tcp->th_dport, sizeof(u_short));
2977 	if (pd->af == AF_INET6) {
2978 		MD5Update(&ctx, (char *)&pd->src->v6, sizeof(struct in6_addr));
2979 		MD5Update(&ctx, (char *)&pd->dst->v6, sizeof(struct in6_addr));
2980 	} else {
2981 		MD5Update(&ctx, (char *)&pd->src->v4, sizeof(struct in_addr));
2982 		MD5Update(&ctx, (char *)&pd->dst->v4, sizeof(struct in_addr));
2983 	}
2984 	MD5Final((u_char *)digest, &ctx);
2985 	V_pf_tcp_iss_off += 4096;
2986 #define	ISN_RANDOM_INCREMENT (4096 - 1)
2987 	return (digest[0] + (arc4random() & ISN_RANDOM_INCREMENT) +
2988 	    V_pf_tcp_iss_off);
2989 #undef	ISN_RANDOM_INCREMENT
2990 }
2991 
2992 static int
pf_test_rule(struct pf_rule ** rm,struct pf_state ** sm,int direction,struct pfi_kif * kif,struct mbuf * m,int off,struct pf_pdesc * pd,struct pf_rule ** am,struct pf_ruleset ** rsm,struct inpcb * inp)2993 pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
2994     struct pfi_kif *kif, struct mbuf *m, int off, struct pf_pdesc *pd,
2995     struct pf_rule **am, struct pf_ruleset **rsm, struct inpcb *inp)
2996 {
2997 	struct pf_rule		*nr = NULL;
2998 	struct pf_addr		* const saddr = pd->src;
2999 	struct pf_addr		* const daddr = pd->dst;
3000 	sa_family_t		 af = pd->af;
3001 	struct pf_rule		*r, *a = NULL;
3002 	struct pf_ruleset	*ruleset = NULL;
3003 	struct pf_src_node	*nsn = NULL;
3004 	struct tcphdr		*th = pd->hdr.tcp;
3005 	struct pf_state_key	*sk = NULL, *nk = NULL;
3006 	u_short			 reason;
3007 	int			 rewrite = 0, hdrlen = 0;
3008 	int			 tag = -1, rtableid = -1;
3009 	int			 asd = 0;
3010 	int			 match = 0;
3011 	int			 state_icmp = 0;
3012 	u_int16_t		 sport = 0, dport = 0;
3013 	u_int16_t		 bproto_sum = 0, bip_sum = 0;
3014 	u_int8_t		 icmptype = 0, icmpcode = 0;
3015 	struct pf_anchor_stackframe	anchor_stack[PF_ANCHOR_STACKSIZE];
3016 
3017 	PF_RULES_RASSERT();
3018 
3019 	if (inp != NULL) {
3020 		INP_LOCK_ASSERT(inp);
3021 		pd->lookup.uid = inp->inp_cred->cr_uid;
3022 		pd->lookup.gid = inp->inp_cred->cr_groups[0];
3023 		pd->lookup.done = 1;
3024 	}
3025 
3026 	switch (pd->proto) {
3027 	case IPPROTO_TCP:
3028 		sport = th->th_sport;
3029 		dport = th->th_dport;
3030 		hdrlen = sizeof(*th);
3031 		break;
3032 	case IPPROTO_UDP:
3033 		sport = pd->hdr.udp->uh_sport;
3034 		dport = pd->hdr.udp->uh_dport;
3035 		hdrlen = sizeof(*pd->hdr.udp);
3036 		break;
3037 #ifdef INET
3038 	case IPPROTO_ICMP:
3039 		if (pd->af != AF_INET)
3040 			break;
3041 		sport = dport = pd->hdr.icmp->icmp_id;
3042 		hdrlen = sizeof(*pd->hdr.icmp);
3043 		icmptype = pd->hdr.icmp->icmp_type;
3044 		icmpcode = pd->hdr.icmp->icmp_code;
3045 
3046 		if (icmptype == ICMP_UNREACH ||
3047 		    icmptype == ICMP_SOURCEQUENCH ||
3048 		    icmptype == ICMP_REDIRECT ||
3049 		    icmptype == ICMP_TIMXCEED ||
3050 		    icmptype == ICMP_PARAMPROB)
3051 			state_icmp++;
3052 		break;
3053 #endif /* INET */
3054 #ifdef INET6
3055 	case IPPROTO_ICMPV6:
3056 		if (af != AF_INET6)
3057 			break;
3058 		sport = dport = pd->hdr.icmp6->icmp6_id;
3059 		hdrlen = sizeof(*pd->hdr.icmp6);
3060 		icmptype = pd->hdr.icmp6->icmp6_type;
3061 		icmpcode = pd->hdr.icmp6->icmp6_code;
3062 
3063 		if (icmptype == ICMP6_DST_UNREACH ||
3064 		    icmptype == ICMP6_PACKET_TOO_BIG ||
3065 		    icmptype == ICMP6_TIME_EXCEEDED ||
3066 		    icmptype == ICMP6_PARAM_PROB)
3067 			state_icmp++;
3068 		break;
3069 #endif /* INET6 */
3070 	default:
3071 		sport = dport = hdrlen = 0;
3072 		break;
3073 	}
3074 
3075 	r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr);
3076 
3077 	/* check packet for BINAT/NAT/RDR */
3078 	if ((nr = pf_get_translation(pd, m, off, direction, kif, &nsn, &sk,
3079 	    &nk, saddr, daddr, sport, dport, anchor_stack)) != NULL) {
3080 		KASSERT(sk != NULL, ("%s: null sk", __func__));
3081 		KASSERT(nk != NULL, ("%s: null nk", __func__));
3082 
3083 		if (pd->ip_sum)
3084 			bip_sum = *pd->ip_sum;
3085 
3086 		switch (pd->proto) {
3087 		case IPPROTO_TCP:
3088 			bproto_sum = th->th_sum;
3089 			pd->proto_sum = &th->th_sum;
3090 
3091 			if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
3092 			    nk->port[pd->sidx] != sport) {
3093 				pf_change_ap(saddr, &th->th_sport, pd->ip_sum,
3094 				    &th->th_sum, &nk->addr[pd->sidx],
3095 				    nk->port[pd->sidx], 0, af);
3096 				pd->sport = &th->th_sport;
3097 				sport = th->th_sport;
3098 			}
3099 
3100 			if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
3101 			    nk->port[pd->didx] != dport) {
3102 				pf_change_ap(daddr, &th->th_dport, pd->ip_sum,
3103 				    &th->th_sum, &nk->addr[pd->didx],
3104 				    nk->port[pd->didx], 0, af);
3105 				dport = th->th_dport;
3106 				pd->dport = &th->th_dport;
3107 			}
3108 			rewrite++;
3109 			break;
3110 		case IPPROTO_UDP:
3111 			bproto_sum = pd->hdr.udp->uh_sum;
3112 			pd->proto_sum = &pd->hdr.udp->uh_sum;
3113 
3114 			if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
3115 			    nk->port[pd->sidx] != sport) {
3116 				pf_change_ap(saddr, &pd->hdr.udp->uh_sport,
3117 				    pd->ip_sum, &pd->hdr.udp->uh_sum,
3118 				    &nk->addr[pd->sidx],
3119 				    nk->port[pd->sidx], 1, af);
3120 				sport = pd->hdr.udp->uh_sport;
3121 				pd->sport = &pd->hdr.udp->uh_sport;
3122 			}
3123 
3124 			if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
3125 			    nk->port[pd->didx] != dport) {
3126 				pf_change_ap(daddr, &pd->hdr.udp->uh_dport,
3127 				    pd->ip_sum, &pd->hdr.udp->uh_sum,
3128 				    &nk->addr[pd->didx],
3129 				    nk->port[pd->didx], 1, af);
3130 				dport = pd->hdr.udp->uh_dport;
3131 				pd->dport = &pd->hdr.udp->uh_dport;
3132 			}
3133 			rewrite++;
3134 			break;
3135 #ifdef INET
3136 		case IPPROTO_ICMP:
3137 			nk->port[0] = nk->port[1];
3138 			if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET))
3139 				pf_change_a(&saddr->v4.s_addr, pd->ip_sum,
3140 				    nk->addr[pd->sidx].v4.s_addr, 0);
3141 
3142 			if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET))
3143 				pf_change_a(&daddr->v4.s_addr, pd->ip_sum,
3144 				    nk->addr[pd->didx].v4.s_addr, 0);
3145 
3146 			if (nk->port[1] != pd->hdr.icmp->icmp_id) {
3147 				pd->hdr.icmp->icmp_cksum = pf_cksum_fixup(
3148 				    pd->hdr.icmp->icmp_cksum, sport,
3149 				    nk->port[1], 0);
3150 				pd->hdr.icmp->icmp_id = nk->port[1];
3151 				pd->sport = &pd->hdr.icmp->icmp_id;
3152 			}
3153 			m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp);
3154 			break;
3155 #endif /* INET */
3156 #ifdef INET6
3157 		case IPPROTO_ICMPV6:
3158 			nk->port[0] = nk->port[1];
3159 			if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET6))
3160 				pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum,
3161 				    &nk->addr[pd->sidx], 0);
3162 
3163 			if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET6))
3164 				pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum,
3165 				    &nk->addr[pd->didx], 0);
3166 			rewrite++;
3167 			break;
3168 #endif /* INET */
3169 		default:
3170 			switch (af) {
3171 #ifdef INET
3172 			case AF_INET:
3173 				if (PF_ANEQ(saddr,
3174 				    &nk->addr[pd->sidx], AF_INET))
3175 					pf_change_a(&saddr->v4.s_addr,
3176 					    pd->ip_sum,
3177 					    nk->addr[pd->sidx].v4.s_addr, 0);
3178 
3179 				if (PF_ANEQ(daddr,
3180 				    &nk->addr[pd->didx], AF_INET))
3181 					pf_change_a(&daddr->v4.s_addr,
3182 					    pd->ip_sum,
3183 					    nk->addr[pd->didx].v4.s_addr, 0);
3184 				break;
3185 #endif /* INET */
3186 #ifdef INET6
3187 			case AF_INET6:
3188 				if (PF_ANEQ(saddr,
3189 				    &nk->addr[pd->sidx], AF_INET6))
3190 					PF_ACPY(saddr, &nk->addr[pd->sidx], af);
3191 
3192 				if (PF_ANEQ(daddr,
3193 				    &nk->addr[pd->didx], AF_INET6))
3194 					PF_ACPY(saddr, &nk->addr[pd->didx], af);
3195 				break;
3196 #endif /* INET */
3197 			}
3198 			break;
3199 		}
3200 		if (nr->natpass)
3201 			r = NULL;
3202 		pd->nat_rule = nr;
3203 	}
3204 
3205 	while (r != NULL) {
3206 		r->evaluations++;
3207 		if (pfi_kif_match(r->kif, kif) == r->ifnot)
3208 			r = r->skip[PF_SKIP_IFP].ptr;
3209 		else if (r->direction && r->direction != direction)
3210 			r = r->skip[PF_SKIP_DIR].ptr;
3211 		else if (r->af && r->af != af)
3212 			r = r->skip[PF_SKIP_AF].ptr;
3213 		else if (r->proto && r->proto != pd->proto)
3214 			r = r->skip[PF_SKIP_PROTO].ptr;
3215 		else if (PF_MISMATCHAW(&r->src.addr, saddr, af,
3216 		    r->src.neg, kif, M_GETFIB(m)))
3217 			r = r->skip[PF_SKIP_SRC_ADDR].ptr;
3218 		/* tcp/udp only. port_op always 0 in other cases */
3219 		else if (r->src.port_op && !pf_match_port(r->src.port_op,
3220 		    r->src.port[0], r->src.port[1], sport))
3221 			r = r->skip[PF_SKIP_SRC_PORT].ptr;
3222 		else if (PF_MISMATCHAW(&r->dst.addr, daddr, af,
3223 		    r->dst.neg, NULL, M_GETFIB(m)))
3224 			r = r->skip[PF_SKIP_DST_ADDR].ptr;
3225 		/* tcp/udp only. port_op always 0 in other cases */
3226 		else if (r->dst.port_op && !pf_match_port(r->dst.port_op,
3227 		    r->dst.port[0], r->dst.port[1], dport))
3228 			r = r->skip[PF_SKIP_DST_PORT].ptr;
3229 		/* icmp only. type always 0 in other cases */
3230 		else if (r->type && r->type != icmptype + 1)
3231 			r = TAILQ_NEXT(r, entries);
3232 		/* icmp only. type always 0 in other cases */
3233 		else if (r->code && r->code != icmpcode + 1)
3234 			r = TAILQ_NEXT(r, entries);
3235 		else if (r->tos && !(r->tos == pd->tos))
3236 			r = TAILQ_NEXT(r, entries);
3237 		else if (r->rule_flag & PFRULE_FRAGMENT)
3238 			r = TAILQ_NEXT(r, entries);
3239 		else if (pd->proto == IPPROTO_TCP &&
3240 		    (r->flagset & th->th_flags) != r->flags)
3241 			r = TAILQ_NEXT(r, entries);
3242 		/* tcp/udp only. uid.op always 0 in other cases */
3243 		else if (r->uid.op && (pd->lookup.done || (pd->lookup.done =
3244 		    pf_socket_lookup(direction, pd, m), 1)) &&
3245 		    !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1],
3246 		    pd->lookup.uid))
3247 			r = TAILQ_NEXT(r, entries);
3248 		/* tcp/udp only. gid.op always 0 in other cases */
3249 		else if (r->gid.op && (pd->lookup.done || (pd->lookup.done =
3250 		    pf_socket_lookup(direction, pd, m), 1)) &&
3251 		    !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1],
3252 		    pd->lookup.gid))
3253 			r = TAILQ_NEXT(r, entries);
3254 		else if (r->prob &&
3255 		    r->prob <= arc4random())
3256 			r = TAILQ_NEXT(r, entries);
3257 		else if (r->match_tag && !pf_match_tag(m, r, &tag,
3258 		    pd->pf_mtag ? pd->pf_mtag->tag : 0))
3259 			r = TAILQ_NEXT(r, entries);
3260 		else if (r->os_fingerprint != PF_OSFP_ANY &&
3261 		    (pd->proto != IPPROTO_TCP || !pf_osfp_match(
3262 		    pf_osfp_fingerprint(pd, m, off, th),
3263 		    r->os_fingerprint)))
3264 			r = TAILQ_NEXT(r, entries);
3265 		else {
3266 			if (r->tag)
3267 				tag = r->tag;
3268 			if (r->rtableid >= 0)
3269 				rtableid = r->rtableid;
3270 			if (r->anchor == NULL) {
3271 				match = 1;
3272 				*rm = r;
3273 				*am = a;
3274 				*rsm = ruleset;
3275 				if ((*rm)->quick)
3276 					break;
3277 				r = TAILQ_NEXT(r, entries);
3278 			} else
3279 				pf_step_into_anchor(anchor_stack, &asd,
3280 				    &ruleset, PF_RULESET_FILTER, &r, &a,
3281 				    &match);
3282 		}
3283 		if (r == NULL && pf_step_out_of_anchor(anchor_stack, &asd,
3284 		    &ruleset, PF_RULESET_FILTER, &r, &a, &match))
3285 			break;
3286 	}
3287 	r = *rm;
3288 	a = *am;
3289 	ruleset = *rsm;
3290 
3291 	REASON_SET(&reason, PFRES_MATCH);
3292 
3293 	if (r->log || (nr != NULL && nr->log)) {
3294 		if (rewrite)
3295 			m_copyback(m, off, hdrlen, pd->hdr.any);
3296 		PFLOG_PACKET(kif, m, af, direction, reason, r->log ? r : nr, a,
3297 		    ruleset, pd, 1);
3298 	}
3299 
3300 	if ((r->action == PF_DROP) &&
3301 	    ((r->rule_flag & PFRULE_RETURNRST) ||
3302 	    (r->rule_flag & PFRULE_RETURNICMP) ||
3303 	    (r->rule_flag & PFRULE_RETURN))) {
3304 		/* undo NAT changes, if they have taken place */
3305 		if (nr != NULL) {
3306 			PF_ACPY(saddr, &sk->addr[pd->sidx], af);
3307 			PF_ACPY(daddr, &sk->addr[pd->didx], af);
3308 			if (pd->sport)
3309 				*pd->sport = sk->port[pd->sidx];
3310 			if (pd->dport)
3311 				*pd->dport = sk->port[pd->didx];
3312 			if (pd->proto_sum)
3313 				*pd->proto_sum = bproto_sum;
3314 			if (pd->ip_sum)
3315 				*pd->ip_sum = bip_sum;
3316 			m_copyback(m, off, hdrlen, pd->hdr.any);
3317 		}
3318 		if (pd->proto == IPPROTO_TCP &&
3319 		    ((r->rule_flag & PFRULE_RETURNRST) ||
3320 		    (r->rule_flag & PFRULE_RETURN)) &&
3321 		    !(th->th_flags & TH_RST)) {
3322 			u_int32_t	 ack = ntohl(th->th_seq) + pd->p_len;
3323 			int		 len = 0;
3324 #ifdef INET
3325 			struct ip	*h4;
3326 #endif
3327 #ifdef INET6
3328 			struct ip6_hdr	*h6;
3329 #endif
3330 
3331 			switch (af) {
3332 #ifdef INET
3333 			case AF_INET:
3334 				h4 = mtod(m, struct ip *);
3335 				len = ntohs(h4->ip_len) - off;
3336 				break;
3337 #endif
3338 #ifdef INET6
3339 			case AF_INET6:
3340 				h6 = mtod(m, struct ip6_hdr *);
3341 				len = ntohs(h6->ip6_plen) - (off - sizeof(*h6));
3342 				break;
3343 #endif
3344 			}
3345 
3346 			if (pf_check_proto_cksum(m, off, len, IPPROTO_TCP, af))
3347 				REASON_SET(&reason, PFRES_PROTCKSUM);
3348 			else {
3349 				if (th->th_flags & TH_SYN)
3350 					ack++;
3351 				if (th->th_flags & TH_FIN)
3352 					ack++;
3353 				pf_send_tcp(m, r, af, pd->dst,
3354 				    pd->src, th->th_dport, th->th_sport,
3355 				    ntohl(th->th_ack), ack, TH_RST|TH_ACK, 0, 0,
3356 				    r->return_ttl, 1, 0, kif->pfik_ifp);
3357 			}
3358 		} else if (pd->proto != IPPROTO_ICMP && af == AF_INET &&
3359 		    r->return_icmp)
3360 			pf_send_icmp(m, r->return_icmp >> 8,
3361 			    r->return_icmp & 255, af, r);
3362 		else if (pd->proto != IPPROTO_ICMPV6 && af == AF_INET6 &&
3363 		    r->return_icmp6)
3364 			pf_send_icmp(m, r->return_icmp6 >> 8,
3365 			    r->return_icmp6 & 255, af, r);
3366 	}
3367 
3368 	if (r->action == PF_DROP)
3369 		goto cleanup;
3370 
3371 	if (tag > 0 && pf_tag_packet(m, pd, tag)) {
3372 		REASON_SET(&reason, PFRES_MEMORY);
3373 		goto cleanup;
3374 	}
3375 	if (rtableid >= 0)
3376 		M_SETFIB(m, rtableid);
3377 
3378 	if (!state_icmp && (r->keep_state || nr != NULL ||
3379 	    (pd->flags & PFDESC_TCP_NORM))) {
3380 		int action;
3381 		action = pf_create_state(r, nr, a, pd, nsn, nk, sk, m, off,
3382 		    sport, dport, &rewrite, kif, sm, tag, bproto_sum, bip_sum,
3383 		    hdrlen);
3384 		if (action != PF_PASS)
3385 			return (action);
3386 	} else {
3387 		if (sk != NULL)
3388 			uma_zfree(V_pf_state_key_z, sk);
3389 		if (nk != NULL)
3390 			uma_zfree(V_pf_state_key_z, nk);
3391 	}
3392 
3393 	/* copy back packet headers if we performed NAT operations */
3394 	if (rewrite)
3395 		m_copyback(m, off, hdrlen, pd->hdr.any);
3396 
3397 	if (*sm != NULL && !((*sm)->state_flags & PFSTATE_NOSYNC) &&
3398 	    direction == PF_OUT &&
3399 	    pfsync_defer_ptr != NULL && pfsync_defer_ptr(*sm, m))
3400 		/*
3401 		 * We want the state created, but we dont
3402 		 * want to send this in case a partner
3403 		 * firewall has to know about it to allow
3404 		 * replies through it.
3405 		 */
3406 		return (PF_DEFER);
3407 
3408 	return (PF_PASS);
3409 
3410 cleanup:
3411 	if (sk != NULL)
3412 		uma_zfree(V_pf_state_key_z, sk);
3413 	if (nk != NULL)
3414 		uma_zfree(V_pf_state_key_z, nk);
3415 	return (PF_DROP);
3416 }
3417 
3418 static int
pf_create_state(struct pf_rule * r,struct pf_rule * nr,struct pf_rule * a,struct pf_pdesc * pd,struct pf_src_node * nsn,struct pf_state_key * nk,struct pf_state_key * sk,struct mbuf * m,int off,u_int16_t sport,u_int16_t dport,int * rewrite,struct pfi_kif * kif,struct pf_state ** sm,int tag,u_int16_t bproto_sum,u_int16_t bip_sum,int hdrlen)3419 pf_create_state(struct pf_rule *r, struct pf_rule *nr, struct pf_rule *a,
3420     struct pf_pdesc *pd, struct pf_src_node *nsn, struct pf_state_key *nk,
3421     struct pf_state_key *sk, struct mbuf *m, int off, u_int16_t sport,
3422     u_int16_t dport, int *rewrite, struct pfi_kif *kif, struct pf_state **sm,
3423     int tag, u_int16_t bproto_sum, u_int16_t bip_sum, int hdrlen)
3424 {
3425 	struct pf_state		*s = NULL;
3426 	struct pf_src_node	*sn = NULL;
3427 	struct tcphdr		*th = pd->hdr.tcp;
3428 	u_int16_t		 mss = V_tcp_mssdflt;
3429 	u_short			 reason;
3430 
3431 	/* check maximums */
3432 	if (r->max_states &&
3433 	    (counter_u64_fetch(r->states_cur) >= r->max_states)) {
3434 		counter_u64_add(V_pf_status.lcounters[LCNT_STATES], 1);
3435 		REASON_SET(&reason, PFRES_MAXSTATES);
3436 		return (PF_DROP);
3437 	}
3438 	/* src node for filter rule */
3439 	if ((r->rule_flag & PFRULE_SRCTRACK ||
3440 	    r->rpool.opts & PF_POOL_STICKYADDR) &&
3441 	    pf_insert_src_node(&sn, r, pd->src, pd->af) != 0) {
3442 		REASON_SET(&reason, PFRES_SRCLIMIT);
3443 		goto csfailed;
3444 	}
3445 	/* src node for translation rule */
3446 	if (nr != NULL && (nr->rpool.opts & PF_POOL_STICKYADDR) &&
3447 	    pf_insert_src_node(&nsn, nr, &sk->addr[pd->sidx], pd->af)) {
3448 		REASON_SET(&reason, PFRES_SRCLIMIT);
3449 		goto csfailed;
3450 	}
3451 	s = uma_zalloc(V_pf_state_z, M_NOWAIT | M_ZERO);
3452 	if (s == NULL) {
3453 		REASON_SET(&reason, PFRES_MEMORY);
3454 		goto csfailed;
3455 	}
3456 	s->rule.ptr = r;
3457 	s->nat_rule.ptr = nr;
3458 	s->anchor.ptr = a;
3459 	STATE_INC_COUNTERS(s);
3460 	if (r->allow_opts)
3461 		s->state_flags |= PFSTATE_ALLOWOPTS;
3462 	if (r->rule_flag & PFRULE_STATESLOPPY)
3463 		s->state_flags |= PFSTATE_SLOPPY;
3464 	s->log = r->log & PF_LOG_ALL;
3465 	s->sync_state = PFSYNC_S_NONE;
3466 	if (nr != NULL)
3467 		s->log |= nr->log & PF_LOG_ALL;
3468 	switch (pd->proto) {
3469 	case IPPROTO_TCP:
3470 		s->src.seqlo = ntohl(th->th_seq);
3471 		s->src.seqhi = s->src.seqlo + pd->p_len + 1;
3472 		if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN &&
3473 		    r->keep_state == PF_STATE_MODULATE) {
3474 			/* Generate sequence number modulator */
3475 			if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) ==
3476 			    0)
3477 				s->src.seqdiff = 1;
3478 			pf_change_a(&th->th_seq, &th->th_sum,
3479 			    htonl(s->src.seqlo + s->src.seqdiff), 0);
3480 			*rewrite = 1;
3481 		} else
3482 			s->src.seqdiff = 0;
3483 		if (th->th_flags & TH_SYN) {
3484 			s->src.seqhi++;
3485 			s->src.wscale = pf_get_wscale(m, off,
3486 			    th->th_off, pd->af);
3487 		}
3488 		s->src.max_win = MAX(ntohs(th->th_win), 1);
3489 		if (s->src.wscale & PF_WSCALE_MASK) {
3490 			/* Remove scale factor from initial window */
3491 			int win = s->src.max_win;
3492 			win += 1 << (s->src.wscale & PF_WSCALE_MASK);
3493 			s->src.max_win = (win - 1) >>
3494 			    (s->src.wscale & PF_WSCALE_MASK);
3495 		}
3496 		if (th->th_flags & TH_FIN)
3497 			s->src.seqhi++;
3498 		s->dst.seqhi = 1;
3499 		s->dst.max_win = 1;
3500 		s->src.state = TCPS_SYN_SENT;
3501 		s->dst.state = TCPS_CLOSED;
3502 		s->timeout = PFTM_TCP_FIRST_PACKET;
3503 		break;
3504 	case IPPROTO_UDP:
3505 		s->src.state = PFUDPS_SINGLE;
3506 		s->dst.state = PFUDPS_NO_TRAFFIC;
3507 		s->timeout = PFTM_UDP_FIRST_PACKET;
3508 		break;
3509 	case IPPROTO_ICMP:
3510 #ifdef INET6
3511 	case IPPROTO_ICMPV6:
3512 #endif
3513 		s->timeout = PFTM_ICMP_FIRST_PACKET;
3514 		break;
3515 	default:
3516 		s->src.state = PFOTHERS_SINGLE;
3517 		s->dst.state = PFOTHERS_NO_TRAFFIC;
3518 		s->timeout = PFTM_OTHER_FIRST_PACKET;
3519 	}
3520 
3521 	if (r->rt && r->rt != PF_FASTROUTE) {
3522 		if (pf_map_addr(pd->af, r, pd->src, &s->rt_addr, NULL, &sn)) {
3523 			REASON_SET(&reason, PFRES_BADSTATE);
3524 			pf_src_tree_remove_state(s);
3525 			STATE_DEC_COUNTERS(s);
3526 			uma_zfree(V_pf_state_z, s);
3527 			goto csfailed;
3528 		}
3529 		s->rt_kif = r->rpool.cur->kif;
3530 	}
3531 
3532 	s->creation = time_uptime;
3533 	s->expire = time_uptime;
3534 
3535 	if (sn != NULL) {
3536 		s->src_node = sn;
3537 		s->src_node->states++;
3538 	}
3539 	if (nsn != NULL) {
3540 		/* XXX We only modify one side for now. */
3541 		PF_ACPY(&nsn->raddr, &nk->addr[1], pd->af);
3542 		s->nat_src_node = nsn;
3543 		s->nat_src_node->states++;
3544 	}
3545 	if (pd->proto == IPPROTO_TCP) {
3546 		if ((pd->flags & PFDESC_TCP_NORM) && pf_normalize_tcp_init(m,
3547 		    off, pd, th, &s->src, &s->dst)) {
3548 			REASON_SET(&reason, PFRES_MEMORY);
3549 			pf_src_tree_remove_state(s);
3550 			STATE_DEC_COUNTERS(s);
3551 			uma_zfree(V_pf_state_z, s);
3552 			return (PF_DROP);
3553 		}
3554 		if ((pd->flags & PFDESC_TCP_NORM) && s->src.scrub &&
3555 		    pf_normalize_tcp_stateful(m, off, pd, &reason, th, s,
3556 		    &s->src, &s->dst, rewrite)) {
3557 			/* This really shouldn't happen!!! */
3558 			DPFPRINTF(PF_DEBUG_URGENT,
3559 			    ("pf_normalize_tcp_stateful failed on first pkt"));
3560 			pf_normalize_tcp_cleanup(s);
3561 			pf_src_tree_remove_state(s);
3562 			STATE_DEC_COUNTERS(s);
3563 			uma_zfree(V_pf_state_z, s);
3564 			return (PF_DROP);
3565 		}
3566 	}
3567 	s->direction = pd->dir;
3568 
3569 	/*
3570 	 * sk/nk could already been setup by pf_get_translation().
3571 	 */
3572 	if (nr == NULL) {
3573 		KASSERT((sk == NULL && nk == NULL), ("%s: nr %p sk %p, nk %p",
3574 		    __func__, nr, sk, nk));
3575 		sk = pf_state_key_setup(pd, pd->src, pd->dst, sport, dport);
3576 		if (sk == NULL)
3577 			goto csfailed;
3578 		nk = sk;
3579 	} else
3580 		KASSERT((sk != NULL && nk != NULL), ("%s: nr %p sk %p, nk %p",
3581 		    __func__, nr, sk, nk));
3582 
3583 	/* Swap sk/nk for PF_OUT. */
3584 	if (pf_state_insert(BOUND_IFACE(r, kif),
3585 	    (pd->dir == PF_IN) ? sk : nk,
3586 	    (pd->dir == PF_IN) ? nk : sk, s)) {
3587 		if (pd->proto == IPPROTO_TCP)
3588 			pf_normalize_tcp_cleanup(s);
3589 		REASON_SET(&reason, PFRES_STATEINS);
3590 		pf_src_tree_remove_state(s);
3591 		STATE_DEC_COUNTERS(s);
3592 		uma_zfree(V_pf_state_z, s);
3593 		return (PF_DROP);
3594 	} else
3595 		*sm = s;
3596 
3597 	if (tag > 0)
3598 		s->tag = tag;
3599 	if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) ==
3600 	    TH_SYN && r->keep_state == PF_STATE_SYNPROXY) {
3601 		s->src.state = PF_TCPS_PROXY_SRC;
3602 		/* undo NAT changes, if they have taken place */
3603 		if (nr != NULL) {
3604 			struct pf_state_key *skt = s->key[PF_SK_WIRE];
3605 			if (pd->dir == PF_OUT)
3606 				skt = s->key[PF_SK_STACK];
3607 			PF_ACPY(pd->src, &skt->addr[pd->sidx], pd->af);
3608 			PF_ACPY(pd->dst, &skt->addr[pd->didx], pd->af);
3609 			if (pd->sport)
3610 				*pd->sport = skt->port[pd->sidx];
3611 			if (pd->dport)
3612 				*pd->dport = skt->port[pd->didx];
3613 			if (pd->proto_sum)
3614 				*pd->proto_sum = bproto_sum;
3615 			if (pd->ip_sum)
3616 				*pd->ip_sum = bip_sum;
3617 			m_copyback(m, off, hdrlen, pd->hdr.any);
3618 		}
3619 		s->src.seqhi = htonl(arc4random());
3620 		/* Find mss option */
3621 		int rtid = M_GETFIB(m);
3622 		mss = pf_get_mss(m, off, th->th_off, pd->af);
3623 		mss = pf_calc_mss(pd->src, pd->af, rtid, mss);
3624 		mss = pf_calc_mss(pd->dst, pd->af, rtid, mss);
3625 		s->src.mss = mss;
3626 		pf_send_tcp(NULL, r, pd->af, pd->dst, pd->src, th->th_dport,
3627 		    th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1,
3628 		    TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, NULL);
3629 		REASON_SET(&reason, PFRES_SYNPROXY);
3630 		return (PF_SYNPROXY_DROP);
3631 	}
3632 
3633 	return (PF_PASS);
3634 
3635 csfailed:
3636 	if (sk != NULL)
3637 		uma_zfree(V_pf_state_key_z, sk);
3638 	if (nk != NULL)
3639 		uma_zfree(V_pf_state_key_z, nk);
3640 
3641 	if (sn != NULL && sn->states == 0 && sn->expire == 0) {
3642 		pf_unlink_src_node(sn);
3643 		pf_free_src_node(sn);
3644 	}
3645 
3646 	if (nsn != sn && nsn != NULL && nsn->states == 0 && nsn->expire == 0) {
3647 		pf_unlink_src_node(nsn);
3648 		pf_free_src_node(nsn);
3649 	}
3650 
3651 	return (PF_DROP);
3652 }
3653 
3654 static int
pf_test_fragment(struct pf_rule ** rm,int direction,struct pfi_kif * kif,struct mbuf * m,void * h,struct pf_pdesc * pd,struct pf_rule ** am,struct pf_ruleset ** rsm)3655 pf_test_fragment(struct pf_rule **rm, int direction, struct pfi_kif *kif,
3656     struct mbuf *m, void *h, struct pf_pdesc *pd, struct pf_rule **am,
3657     struct pf_ruleset **rsm)
3658 {
3659 	struct pf_rule		*r, *a = NULL;
3660 	struct pf_ruleset	*ruleset = NULL;
3661 	sa_family_t		 af = pd->af;
3662 	u_short			 reason;
3663 	int			 tag = -1;
3664 	int			 asd = 0;
3665 	int			 match = 0;
3666 	struct pf_anchor_stackframe	anchor_stack[PF_ANCHOR_STACKSIZE];
3667 
3668 	PF_RULES_RASSERT();
3669 
3670 	r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr);
3671 	while (r != NULL) {
3672 		r->evaluations++;
3673 		if (pfi_kif_match(r->kif, kif) == r->ifnot)
3674 			r = r->skip[PF_SKIP_IFP].ptr;
3675 		else if (r->direction && r->direction != direction)
3676 			r = r->skip[PF_SKIP_DIR].ptr;
3677 		else if (r->af && r->af != af)
3678 			r = r->skip[PF_SKIP_AF].ptr;
3679 		else if (r->proto && r->proto != pd->proto)
3680 			r = r->skip[PF_SKIP_PROTO].ptr;
3681 		else if (PF_MISMATCHAW(&r->src.addr, pd->src, af,
3682 		    r->src.neg, kif, M_GETFIB(m)))
3683 			r = r->skip[PF_SKIP_SRC_ADDR].ptr;
3684 		else if (PF_MISMATCHAW(&r->dst.addr, pd->dst, af,
3685 		    r->dst.neg, NULL, M_GETFIB(m)))
3686 			r = r->skip[PF_SKIP_DST_ADDR].ptr;
3687 		else if (r->tos && !(r->tos == pd->tos))
3688 			r = TAILQ_NEXT(r, entries);
3689 		else if (r->os_fingerprint != PF_OSFP_ANY)
3690 			r = TAILQ_NEXT(r, entries);
3691 		else if (pd->proto == IPPROTO_UDP &&
3692 		    (r->src.port_op || r->dst.port_op))
3693 			r = TAILQ_NEXT(r, entries);
3694 		else if (pd->proto == IPPROTO_TCP &&
3695 		    (r->src.port_op || r->dst.port_op || r->flagset))
3696 			r = TAILQ_NEXT(r, entries);
3697 		else if ((pd->proto == IPPROTO_ICMP ||
3698 		    pd->proto == IPPROTO_ICMPV6) &&
3699 		    (r->type || r->code))
3700 			r = TAILQ_NEXT(r, entries);
3701 		else if (r->prob && r->prob <=
3702 		    (arc4random() % (UINT_MAX - 1) + 1))
3703 			r = TAILQ_NEXT(r, entries);
3704 		else if (r->match_tag && !pf_match_tag(m, r, &tag,
3705 		    pd->pf_mtag ? pd->pf_mtag->tag : 0))
3706 			r = TAILQ_NEXT(r, entries);
3707 		else {
3708 			if (r->anchor == NULL) {
3709 				match = 1;
3710 				*rm = r;
3711 				*am = a;
3712 				*rsm = ruleset;
3713 				if ((*rm)->quick)
3714 					break;
3715 				r = TAILQ_NEXT(r, entries);
3716 			} else
3717 				pf_step_into_anchor(anchor_stack, &asd,
3718 				    &ruleset, PF_RULESET_FILTER, &r, &a,
3719 				    &match);
3720 		}
3721 		if (r == NULL && pf_step_out_of_anchor(anchor_stack, &asd,
3722 		    &ruleset, PF_RULESET_FILTER, &r, &a, &match))
3723 			break;
3724 	}
3725 	r = *rm;
3726 	a = *am;
3727 	ruleset = *rsm;
3728 
3729 	REASON_SET(&reason, PFRES_MATCH);
3730 
3731 	if (r->log)
3732 		PFLOG_PACKET(kif, m, af, direction, reason, r, a, ruleset, pd,
3733 		    1);
3734 
3735 	if (r->action != PF_PASS)
3736 		return (PF_DROP);
3737 
3738 	if (tag > 0 && pf_tag_packet(m, pd, tag)) {
3739 		REASON_SET(&reason, PFRES_MEMORY);
3740 		return (PF_DROP);
3741 	}
3742 
3743 	return (PF_PASS);
3744 }
3745 
3746 static int
pf_tcp_track_full(struct pf_state_peer * src,struct pf_state_peer * dst,struct pf_state ** state,struct pfi_kif * kif,struct mbuf * m,int off,struct pf_pdesc * pd,u_short * reason,int * copyback)3747 pf_tcp_track_full(struct pf_state_peer *src, struct pf_state_peer *dst,
3748 	struct pf_state **state, struct pfi_kif *kif, struct mbuf *m, int off,
3749 	struct pf_pdesc *pd, u_short *reason, int *copyback)
3750 {
3751 	struct tcphdr		*th = pd->hdr.tcp;
3752 	u_int16_t		 win = ntohs(th->th_win);
3753 	u_int32_t		 ack, end, seq, orig_seq;
3754 	u_int8_t		 sws, dws;
3755 	int			 ackskew;
3756 
3757 	if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) {
3758 		sws = src->wscale & PF_WSCALE_MASK;
3759 		dws = dst->wscale & PF_WSCALE_MASK;
3760 	} else
3761 		sws = dws = 0;
3762 
3763 	/*
3764 	 * Sequence tracking algorithm from Guido van Rooij's paper:
3765 	 *   http://www.madison-gurkha.com/publications/tcp_filtering/
3766 	 *	tcp_filtering.ps
3767 	 */
3768 
3769 	orig_seq = seq = ntohl(th->th_seq);
3770 	if (src->seqlo == 0) {
3771 		/* First packet from this end. Set its state */
3772 
3773 		if ((pd->flags & PFDESC_TCP_NORM || dst->scrub) &&
3774 		    src->scrub == NULL) {
3775 			if (pf_normalize_tcp_init(m, off, pd, th, src, dst)) {
3776 				REASON_SET(reason, PFRES_MEMORY);
3777 				return (PF_DROP);
3778 			}
3779 		}
3780 
3781 		/* Deferred generation of sequence number modulator */
3782 		if (dst->seqdiff && !src->seqdiff) {
3783 			/* use random iss for the TCP server */
3784 			while ((src->seqdiff = arc4random() - seq) == 0)
3785 				;
3786 			ack = ntohl(th->th_ack) - dst->seqdiff;
3787 			pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
3788 			    src->seqdiff), 0);
3789 			pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
3790 			*copyback = 1;
3791 		} else {
3792 			ack = ntohl(th->th_ack);
3793 		}
3794 
3795 		end = seq + pd->p_len;
3796 		if (th->th_flags & TH_SYN) {
3797 			end++;
3798 			if (dst->wscale & PF_WSCALE_FLAG) {
3799 				src->wscale = pf_get_wscale(m, off, th->th_off,
3800 				    pd->af);
3801 				if (src->wscale & PF_WSCALE_FLAG) {
3802 					/* Remove scale factor from initial
3803 					 * window */
3804 					sws = src->wscale & PF_WSCALE_MASK;
3805 					win = ((u_int32_t)win + (1 << sws) - 1)
3806 					    >> sws;
3807 					dws = dst->wscale & PF_WSCALE_MASK;
3808 				} else {
3809 					/* fixup other window */
3810 					dst->max_win <<= dst->wscale &
3811 					    PF_WSCALE_MASK;
3812 					/* in case of a retrans SYN|ACK */
3813 					dst->wscale = 0;
3814 				}
3815 			}
3816 		}
3817 		if (th->th_flags & TH_FIN)
3818 			end++;
3819 
3820 		src->seqlo = seq;
3821 		if (src->state < TCPS_SYN_SENT)
3822 			src->state = TCPS_SYN_SENT;
3823 
3824 		/*
3825 		 * May need to slide the window (seqhi may have been set by
3826 		 * the crappy stack check or if we picked up the connection
3827 		 * after establishment)
3828 		 */
3829 		if (src->seqhi == 1 ||
3830 		    SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi))
3831 			src->seqhi = end + MAX(1, dst->max_win << dws);
3832 		if (win > src->max_win)
3833 			src->max_win = win;
3834 
3835 	} else {
3836 		ack = ntohl(th->th_ack) - dst->seqdiff;
3837 		if (src->seqdiff) {
3838 			/* Modulate sequence numbers */
3839 			pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
3840 			    src->seqdiff), 0);
3841 			pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
3842 			*copyback = 1;
3843 		}
3844 		end = seq + pd->p_len;
3845 		if (th->th_flags & TH_SYN)
3846 			end++;
3847 		if (th->th_flags & TH_FIN)
3848 			end++;
3849 	}
3850 
3851 	if ((th->th_flags & TH_ACK) == 0) {
3852 		/* Let it pass through the ack skew check */
3853 		ack = dst->seqlo;
3854 	} else if ((ack == 0 &&
3855 	    (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) ||
3856 	    /* broken tcp stacks do not set ack */
3857 	    (dst->state < TCPS_SYN_SENT)) {
3858 		/*
3859 		 * Many stacks (ours included) will set the ACK number in an
3860 		 * FIN|ACK if the SYN times out -- no sequence to ACK.
3861 		 */
3862 		ack = dst->seqlo;
3863 	}
3864 
3865 	if (seq == end) {
3866 		/* Ease sequencing restrictions on no data packets */
3867 		seq = src->seqlo;
3868 		end = seq;
3869 	}
3870 
3871 	ackskew = dst->seqlo - ack;
3872 
3873 
3874 	/*
3875 	 * Need to demodulate the sequence numbers in any TCP SACK options
3876 	 * (Selective ACK). We could optionally validate the SACK values
3877 	 * against the current ACK window, either forwards or backwards, but
3878 	 * I'm not confident that SACK has been implemented properly
3879 	 * everywhere. It wouldn't surprise me if several stacks accidently
3880 	 * SACK too far backwards of previously ACKed data. There really aren't
3881 	 * any security implications of bad SACKing unless the target stack
3882 	 * doesn't validate the option length correctly. Someone trying to
3883 	 * spoof into a TCP connection won't bother blindly sending SACK
3884 	 * options anyway.
3885 	 */
3886 	if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) {
3887 		if (pf_modulate_sack(m, off, pd, th, dst))
3888 			*copyback = 1;
3889 	}
3890 
3891 
3892 #define	MAXACKWINDOW (0xffff + 1500)	/* 1500 is an arbitrary fudge factor */
3893 	if (SEQ_GEQ(src->seqhi, end) &&
3894 	    /* Last octet inside other's window space */
3895 	    SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) &&
3896 	    /* Retrans: not more than one window back */
3897 	    (ackskew >= -MAXACKWINDOW) &&
3898 	    /* Acking not more than one reassembled fragment backwards */
3899 	    (ackskew <= (MAXACKWINDOW << sws)) &&
3900 	    /* Acking not more than one window forward */
3901 	    ((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo ||
3902 	    (orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo) ||
3903 	    (pd->flags & PFDESC_IP_REAS) == 0)) {
3904 	    /* Require an exact/+1 sequence match on resets when possible */
3905 
3906 		if (dst->scrub || src->scrub) {
3907 			if (pf_normalize_tcp_stateful(m, off, pd, reason, th,
3908 			    *state, src, dst, copyback))
3909 				return (PF_DROP);
3910 		}
3911 
3912 		/* update max window */
3913 		if (src->max_win < win)
3914 			src->max_win = win;
3915 		/* synchronize sequencing */
3916 		if (SEQ_GT(end, src->seqlo))
3917 			src->seqlo = end;
3918 		/* slide the window of what the other end can send */
3919 		if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
3920 			dst->seqhi = ack + MAX((win << sws), 1);
3921 
3922 
3923 		/* update states */
3924 		if (th->th_flags & TH_SYN)
3925 			if (src->state < TCPS_SYN_SENT)
3926 				src->state = TCPS_SYN_SENT;
3927 		if (th->th_flags & TH_FIN)
3928 			if (src->state < TCPS_CLOSING)
3929 				src->state = TCPS_CLOSING;
3930 		if (th->th_flags & TH_ACK) {
3931 			if (dst->state == TCPS_SYN_SENT) {
3932 				dst->state = TCPS_ESTABLISHED;
3933 				if (src->state == TCPS_ESTABLISHED &&
3934 				    (*state)->src_node != NULL &&
3935 				    pf_src_connlimit(state)) {
3936 					REASON_SET(reason, PFRES_SRCLIMIT);
3937 					return (PF_DROP);
3938 				}
3939 			} else if (dst->state == TCPS_CLOSING)
3940 				dst->state = TCPS_FIN_WAIT_2;
3941 		}
3942 		if (th->th_flags & TH_RST)
3943 			src->state = dst->state = TCPS_TIME_WAIT;
3944 
3945 		/* update expire time */
3946 		(*state)->expire = time_uptime;
3947 		if (src->state >= TCPS_FIN_WAIT_2 &&
3948 		    dst->state >= TCPS_FIN_WAIT_2)
3949 			(*state)->timeout = PFTM_TCP_CLOSED;
3950 		else if (src->state >= TCPS_CLOSING &&
3951 		    dst->state >= TCPS_CLOSING)
3952 			(*state)->timeout = PFTM_TCP_FIN_WAIT;
3953 		else if (src->state < TCPS_ESTABLISHED ||
3954 		    dst->state < TCPS_ESTABLISHED)
3955 			(*state)->timeout = PFTM_TCP_OPENING;
3956 		else if (src->state >= TCPS_CLOSING ||
3957 		    dst->state >= TCPS_CLOSING)
3958 			(*state)->timeout = PFTM_TCP_CLOSING;
3959 		else
3960 			(*state)->timeout = PFTM_TCP_ESTABLISHED;
3961 
3962 		/* Fall through to PASS packet */
3963 
3964 	} else if ((dst->state < TCPS_SYN_SENT ||
3965 		dst->state >= TCPS_FIN_WAIT_2 ||
3966 		src->state >= TCPS_FIN_WAIT_2) &&
3967 	    SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) &&
3968 	    /* Within a window forward of the originating packet */
3969 	    SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) {
3970 	    /* Within a window backward of the originating packet */
3971 
3972 		/*
3973 		 * This currently handles three situations:
3974 		 *  1) Stupid stacks will shotgun SYNs before their peer
3975 		 *     replies.
3976 		 *  2) When PF catches an already established stream (the
3977 		 *     firewall rebooted, the state table was flushed, routes
3978 		 *     changed...)
3979 		 *  3) Packets get funky immediately after the connection
3980 		 *     closes (this should catch Solaris spurious ACK|FINs
3981 		 *     that web servers like to spew after a close)
3982 		 *
3983 		 * This must be a little more careful than the above code
3984 		 * since packet floods will also be caught here. We don't
3985 		 * update the TTL here to mitigate the damage of a packet
3986 		 * flood and so the same code can handle awkward establishment
3987 		 * and a loosened connection close.
3988 		 * In the establishment case, a correct peer response will
3989 		 * validate the connection, go through the normal state code
3990 		 * and keep updating the state TTL.
3991 		 */
3992 
3993 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
3994 			printf("pf: loose state match: ");
3995 			pf_print_state(*state);
3996 			pf_print_flags(th->th_flags);
3997 			printf(" seq=%u (%u) ack=%u len=%u ackskew=%d "
3998 			    "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack,
3999 			    pd->p_len, ackskew, (unsigned long long)(*state)->packets[0],
4000 			    (unsigned long long)(*state)->packets[1],
4001 			    pd->dir == PF_IN ? "in" : "out",
4002 			    pd->dir == (*state)->direction ? "fwd" : "rev");
4003 		}
4004 
4005 		if (dst->scrub || src->scrub) {
4006 			if (pf_normalize_tcp_stateful(m, off, pd, reason, th,
4007 			    *state, src, dst, copyback))
4008 				return (PF_DROP);
4009 		}
4010 
4011 		/* update max window */
4012 		if (src->max_win < win)
4013 			src->max_win = win;
4014 		/* synchronize sequencing */
4015 		if (SEQ_GT(end, src->seqlo))
4016 			src->seqlo = end;
4017 		/* slide the window of what the other end can send */
4018 		if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
4019 			dst->seqhi = ack + MAX((win << sws), 1);
4020 
4021 		/*
4022 		 * Cannot set dst->seqhi here since this could be a shotgunned
4023 		 * SYN and not an already established connection.
4024 		 */
4025 
4026 		if (th->th_flags & TH_FIN)
4027 			if (src->state < TCPS_CLOSING)
4028 				src->state = TCPS_CLOSING;
4029 		if (th->th_flags & TH_RST)
4030 			src->state = dst->state = TCPS_TIME_WAIT;
4031 
4032 		/* Fall through to PASS packet */
4033 
4034 	} else {
4035 		if ((*state)->dst.state == TCPS_SYN_SENT &&
4036 		    (*state)->src.state == TCPS_SYN_SENT) {
4037 			/* Send RST for state mismatches during handshake */
4038 			if (!(th->th_flags & TH_RST))
4039 				pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
4040 				    pd->dst, pd->src, th->th_dport,
4041 				    th->th_sport, ntohl(th->th_ack), 0,
4042 				    TH_RST, 0, 0,
4043 				    (*state)->rule.ptr->return_ttl, 1, 0,
4044 				    kif->pfik_ifp);
4045 			src->seqlo = 0;
4046 			src->seqhi = 1;
4047 			src->max_win = 1;
4048 		} else if (V_pf_status.debug >= PF_DEBUG_MISC) {
4049 			printf("pf: BAD state: ");
4050 			pf_print_state(*state);
4051 			pf_print_flags(th->th_flags);
4052 			printf(" seq=%u (%u) ack=%u len=%u ackskew=%d "
4053 			    "pkts=%llu:%llu dir=%s,%s\n",
4054 			    seq, orig_seq, ack, pd->p_len, ackskew,
4055 			    (unsigned long long)(*state)->packets[0],
4056 			    (unsigned long long)(*state)->packets[1],
4057 			    pd->dir == PF_IN ? "in" : "out",
4058 			    pd->dir == (*state)->direction ? "fwd" : "rev");
4059 			printf("pf: State failure on: %c %c %c %c | %c %c\n",
4060 			    SEQ_GEQ(src->seqhi, end) ? ' ' : '1',
4061 			    SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ?
4062 			    ' ': '2',
4063 			    (ackskew >= -MAXACKWINDOW) ? ' ' : '3',
4064 			    (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4',
4065 			    SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) ?' ' :'5',
4066 			    SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6');
4067 		}
4068 		REASON_SET(reason, PFRES_BADSTATE);
4069 		return (PF_DROP);
4070 	}
4071 
4072 	return (PF_PASS);
4073 }
4074 
4075 static int
pf_tcp_track_sloppy(struct pf_state_peer * src,struct pf_state_peer * dst,struct pf_state ** state,struct pf_pdesc * pd,u_short * reason)4076 pf_tcp_track_sloppy(struct pf_state_peer *src, struct pf_state_peer *dst,
4077 	struct pf_state **state, struct pf_pdesc *pd, u_short *reason)
4078 {
4079 	struct tcphdr		*th = pd->hdr.tcp;
4080 
4081 	if (th->th_flags & TH_SYN)
4082 		if (src->state < TCPS_SYN_SENT)
4083 			src->state = TCPS_SYN_SENT;
4084 	if (th->th_flags & TH_FIN)
4085 		if (src->state < TCPS_CLOSING)
4086 			src->state = TCPS_CLOSING;
4087 	if (th->th_flags & TH_ACK) {
4088 		if (dst->state == TCPS_SYN_SENT) {
4089 			dst->state = TCPS_ESTABLISHED;
4090 			if (src->state == TCPS_ESTABLISHED &&
4091 			    (*state)->src_node != NULL &&
4092 			    pf_src_connlimit(state)) {
4093 				REASON_SET(reason, PFRES_SRCLIMIT);
4094 				return (PF_DROP);
4095 			}
4096 		} else if (dst->state == TCPS_CLOSING) {
4097 			dst->state = TCPS_FIN_WAIT_2;
4098 		} else if (src->state == TCPS_SYN_SENT &&
4099 		    dst->state < TCPS_SYN_SENT) {
4100 			/*
4101 			 * Handle a special sloppy case where we only see one
4102 			 * half of the connection. If there is a ACK after
4103 			 * the initial SYN without ever seeing a packet from
4104 			 * the destination, set the connection to established.
4105 			 */
4106 			dst->state = src->state = TCPS_ESTABLISHED;
4107 			if ((*state)->src_node != NULL &&
4108 			    pf_src_connlimit(state)) {
4109 				REASON_SET(reason, PFRES_SRCLIMIT);
4110 				return (PF_DROP);
4111 			}
4112 		} else if (src->state == TCPS_CLOSING &&
4113 		    dst->state == TCPS_ESTABLISHED &&
4114 		    dst->seqlo == 0) {
4115 			/*
4116 			 * Handle the closing of half connections where we
4117 			 * don't see the full bidirectional FIN/ACK+ACK
4118 			 * handshake.
4119 			 */
4120 			dst->state = TCPS_CLOSING;
4121 		}
4122 	}
4123 	if (th->th_flags & TH_RST)
4124 		src->state = dst->state = TCPS_TIME_WAIT;
4125 
4126 	/* update expire time */
4127 	(*state)->expire = time_uptime;
4128 	if (src->state >= TCPS_FIN_WAIT_2 &&
4129 	    dst->state >= TCPS_FIN_WAIT_2)
4130 		(*state)->timeout = PFTM_TCP_CLOSED;
4131 	else if (src->state >= TCPS_CLOSING &&
4132 	    dst->state >= TCPS_CLOSING)
4133 		(*state)->timeout = PFTM_TCP_FIN_WAIT;
4134 	else if (src->state < TCPS_ESTABLISHED ||
4135 	    dst->state < TCPS_ESTABLISHED)
4136 		(*state)->timeout = PFTM_TCP_OPENING;
4137 	else if (src->state >= TCPS_CLOSING ||
4138 	    dst->state >= TCPS_CLOSING)
4139 		(*state)->timeout = PFTM_TCP_CLOSING;
4140 	else
4141 		(*state)->timeout = PFTM_TCP_ESTABLISHED;
4142 
4143 	return (PF_PASS);
4144 }
4145 
4146 static int
pf_test_state_tcp(struct pf_state ** state,int direction,struct pfi_kif * kif,struct mbuf * m,int off,void * h,struct pf_pdesc * pd,u_short * reason)4147 pf_test_state_tcp(struct pf_state **state, int direction, struct pfi_kif *kif,
4148     struct mbuf *m, int off, void *h, struct pf_pdesc *pd,
4149     u_short *reason)
4150 {
4151 	struct pf_state_key_cmp	 key;
4152 	struct tcphdr		*th = pd->hdr.tcp;
4153 	int			 copyback = 0;
4154 	struct pf_state_peer	*src, *dst;
4155 	struct pf_state_key	*sk;
4156 
4157 	bzero(&key, sizeof(key));
4158 	key.af = pd->af;
4159 	key.proto = IPPROTO_TCP;
4160 	if (direction == PF_IN)	{	/* wire side, straight */
4161 		PF_ACPY(&key.addr[0], pd->src, key.af);
4162 		PF_ACPY(&key.addr[1], pd->dst, key.af);
4163 		key.port[0] = th->th_sport;
4164 		key.port[1] = th->th_dport;
4165 	} else {			/* stack side, reverse */
4166 		PF_ACPY(&key.addr[1], pd->src, key.af);
4167 		PF_ACPY(&key.addr[0], pd->dst, key.af);
4168 		key.port[1] = th->th_sport;
4169 		key.port[0] = th->th_dport;
4170 	}
4171 
4172 	STATE_LOOKUP(kif, &key, direction, *state, pd);
4173 
4174 	if (direction == (*state)->direction) {
4175 		src = &(*state)->src;
4176 		dst = &(*state)->dst;
4177 	} else {
4178 		src = &(*state)->dst;
4179 		dst = &(*state)->src;
4180 	}
4181 
4182 	sk = (*state)->key[pd->didx];
4183 
4184 	if ((*state)->src.state == PF_TCPS_PROXY_SRC) {
4185 		if (direction != (*state)->direction) {
4186 			REASON_SET(reason, PFRES_SYNPROXY);
4187 			return (PF_SYNPROXY_DROP);
4188 		}
4189 		if (th->th_flags & TH_SYN) {
4190 			if (ntohl(th->th_seq) != (*state)->src.seqlo) {
4191 				REASON_SET(reason, PFRES_SYNPROXY);
4192 				return (PF_DROP);
4193 			}
4194 			pf_send_tcp(NULL, (*state)->rule.ptr, pd->af, pd->dst,
4195 			    pd->src, th->th_dport, th->th_sport,
4196 			    (*state)->src.seqhi, ntohl(th->th_seq) + 1,
4197 			    TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 0, NULL);
4198 			REASON_SET(reason, PFRES_SYNPROXY);
4199 			return (PF_SYNPROXY_DROP);
4200 		} else if (!(th->th_flags & TH_ACK) ||
4201 		    (ntohl(th->th_ack) != (*state)->src.seqhi + 1) ||
4202 		    (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) {
4203 			REASON_SET(reason, PFRES_SYNPROXY);
4204 			return (PF_DROP);
4205 		} else if ((*state)->src_node != NULL &&
4206 		    pf_src_connlimit(state)) {
4207 			REASON_SET(reason, PFRES_SRCLIMIT);
4208 			return (PF_DROP);
4209 		} else
4210 			(*state)->src.state = PF_TCPS_PROXY_DST;
4211 	}
4212 	if ((*state)->src.state == PF_TCPS_PROXY_DST) {
4213 		if (direction == (*state)->direction) {
4214 			if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) ||
4215 			    (ntohl(th->th_ack) != (*state)->src.seqhi + 1) ||
4216 			    (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) {
4217 				REASON_SET(reason, PFRES_SYNPROXY);
4218 				return (PF_DROP);
4219 			}
4220 			(*state)->src.max_win = MAX(ntohs(th->th_win), 1);
4221 			if ((*state)->dst.seqhi == 1)
4222 				(*state)->dst.seqhi = htonl(arc4random());
4223 			pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
4224 			    &sk->addr[pd->sidx], &sk->addr[pd->didx],
4225 			    sk->port[pd->sidx], sk->port[pd->didx],
4226 			    (*state)->dst.seqhi, 0, TH_SYN, 0,
4227 			    (*state)->src.mss, 0, 0, (*state)->tag, NULL);
4228 			REASON_SET(reason, PFRES_SYNPROXY);
4229 			return (PF_SYNPROXY_DROP);
4230 		} else if (((th->th_flags & (TH_SYN|TH_ACK)) !=
4231 		    (TH_SYN|TH_ACK)) ||
4232 		    (ntohl(th->th_ack) != (*state)->dst.seqhi + 1)) {
4233 			REASON_SET(reason, PFRES_SYNPROXY);
4234 			return (PF_DROP);
4235 		} else {
4236 			(*state)->dst.max_win = MAX(ntohs(th->th_win), 1);
4237 			(*state)->dst.seqlo = ntohl(th->th_seq);
4238 			pf_send_tcp(NULL, (*state)->rule.ptr, pd->af, pd->dst,
4239 			    pd->src, th->th_dport, th->th_sport,
4240 			    ntohl(th->th_ack), ntohl(th->th_seq) + 1,
4241 			    TH_ACK, (*state)->src.max_win, 0, 0, 0,
4242 			    (*state)->tag, NULL);
4243 			pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
4244 			    &sk->addr[pd->sidx], &sk->addr[pd->didx],
4245 			    sk->port[pd->sidx], sk->port[pd->didx],
4246 			    (*state)->src.seqhi + 1, (*state)->src.seqlo + 1,
4247 			    TH_ACK, (*state)->dst.max_win, 0, 0, 1, 0, NULL);
4248 			(*state)->src.seqdiff = (*state)->dst.seqhi -
4249 			    (*state)->src.seqlo;
4250 			(*state)->dst.seqdiff = (*state)->src.seqhi -
4251 			    (*state)->dst.seqlo;
4252 			(*state)->src.seqhi = (*state)->src.seqlo +
4253 			    (*state)->dst.max_win;
4254 			(*state)->dst.seqhi = (*state)->dst.seqlo +
4255 			    (*state)->src.max_win;
4256 			(*state)->src.wscale = (*state)->dst.wscale = 0;
4257 			(*state)->src.state = (*state)->dst.state =
4258 			    TCPS_ESTABLISHED;
4259 			REASON_SET(reason, PFRES_SYNPROXY);
4260 			return (PF_SYNPROXY_DROP);
4261 		}
4262 	}
4263 
4264 	if (((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN) &&
4265 	    dst->state >= TCPS_FIN_WAIT_2 &&
4266 	    src->state >= TCPS_FIN_WAIT_2) {
4267 		if (V_pf_status.debug >= PF_DEBUG_MISC) {
4268 			printf("pf: state reuse ");
4269 			pf_print_state(*state);
4270 			pf_print_flags(th->th_flags);
4271 			printf("\n");
4272 		}
4273 		/* XXX make sure it's the same direction ?? */
4274 		(*state)->src.state = (*state)->dst.state = TCPS_CLOSED;
4275 		pf_unlink_state(*state, PF_ENTER_LOCKED);
4276 		*state = NULL;
4277 		return (PF_DROP);
4278 	}
4279 
4280 	if ((*state)->state_flags & PFSTATE_SLOPPY) {
4281 		if (pf_tcp_track_sloppy(src, dst, state, pd, reason) == PF_DROP)
4282 			return (PF_DROP);
4283 	} else {
4284 		if (pf_tcp_track_full(src, dst, state, kif, m, off, pd, reason,
4285 		    &copyback) == PF_DROP)
4286 			return (PF_DROP);
4287 	}
4288 
4289 	/* translate source/destination address, if necessary */
4290 	if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
4291 		struct pf_state_key *nk = (*state)->key[pd->didx];
4292 
4293 		if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
4294 		    nk->port[pd->sidx] != th->th_sport)
4295 			pf_change_ap(pd->src, &th->th_sport, pd->ip_sum,
4296 			    &th->th_sum, &nk->addr[pd->sidx],
4297 			    nk->port[pd->sidx], 0, pd->af);
4298 
4299 		if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
4300 		    nk->port[pd->didx] != th->th_dport)
4301 			pf_change_ap(pd->dst, &th->th_dport, pd->ip_sum,
4302 			    &th->th_sum, &nk->addr[pd->didx],
4303 			    nk->port[pd->didx], 0, pd->af);
4304 		copyback = 1;
4305 	}
4306 
4307 	/* Copyback sequence modulation or stateful scrub changes if needed */
4308 	if (copyback)
4309 		m_copyback(m, off, sizeof(*th), (caddr_t)th);
4310 
4311 	return (PF_PASS);
4312 }
4313 
4314 static int
pf_test_state_udp(struct pf_state ** state,int direction,struct pfi_kif * kif,struct mbuf * m,int off,void * h,struct pf_pdesc * pd)4315 pf_test_state_udp(struct pf_state **state, int direction, struct pfi_kif *kif,
4316     struct mbuf *m, int off, void *h, struct pf_pdesc *pd)
4317 {
4318 	struct pf_state_peer	*src, *dst;
4319 	struct pf_state_key_cmp	 key;
4320 	struct udphdr		*uh = pd->hdr.udp;
4321 
4322 	bzero(&key, sizeof(key));
4323 	key.af = pd->af;
4324 	key.proto = IPPROTO_UDP;
4325 	if (direction == PF_IN)	{	/* wire side, straight */
4326 		PF_ACPY(&key.addr[0], pd->src, key.af);
4327 		PF_ACPY(&key.addr[1], pd->dst, key.af);
4328 		key.port[0] = uh->uh_sport;
4329 		key.port[1] = uh->uh_dport;
4330 	} else {			/* stack side, reverse */
4331 		PF_ACPY(&key.addr[1], pd->src, key.af);
4332 		PF_ACPY(&key.addr[0], pd->dst, key.af);
4333 		key.port[1] = uh->uh_sport;
4334 		key.port[0] = uh->uh_dport;
4335 	}
4336 
4337 	STATE_LOOKUP(kif, &key, direction, *state, pd);
4338 
4339 	if (direction == (*state)->direction) {
4340 		src = &(*state)->src;
4341 		dst = &(*state)->dst;
4342 	} else {
4343 		src = &(*state)->dst;
4344 		dst = &(*state)->src;
4345 	}
4346 
4347 	/* update states */
4348 	if (src->state < PFUDPS_SINGLE)
4349 		src->state = PFUDPS_SINGLE;
4350 	if (dst->state == PFUDPS_SINGLE)
4351 		dst->state = PFUDPS_MULTIPLE;
4352 
4353 	/* update expire time */
4354 	(*state)->expire = time_uptime;
4355 	if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE)
4356 		(*state)->timeout = PFTM_UDP_MULTIPLE;
4357 	else
4358 		(*state)->timeout = PFTM_UDP_SINGLE;
4359 
4360 	/* translate source/destination address, if necessary */
4361 	if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
4362 		struct pf_state_key *nk = (*state)->key[pd->didx];
4363 
4364 		if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
4365 		    nk->port[pd->sidx] != uh->uh_sport)
4366 			pf_change_ap(pd->src, &uh->uh_sport, pd->ip_sum,
4367 			    &uh->uh_sum, &nk->addr[pd->sidx],
4368 			    nk->port[pd->sidx], 1, pd->af);
4369 
4370 		if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
4371 		    nk->port[pd->didx] != uh->uh_dport)
4372 			pf_change_ap(pd->dst, &uh->uh_dport, pd->ip_sum,
4373 			    &uh->uh_sum, &nk->addr[pd->didx],
4374 			    nk->port[pd->didx], 1, pd->af);
4375 		m_copyback(m, off, sizeof(*uh), (caddr_t)uh);
4376 	}
4377 
4378 	return (PF_PASS);
4379 }
4380 
4381 static int
pf_test_state_icmp(struct pf_state ** state,int direction,struct pfi_kif * kif,struct mbuf * m,int off,void * h,struct pf_pdesc * pd,u_short * reason)4382 pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif,
4383     struct mbuf *m, int off, void *h, struct pf_pdesc *pd, u_short *reason)
4384 {
4385 	struct pf_addr  *saddr = pd->src, *daddr = pd->dst;
4386 	u_int16_t	 icmpid = 0, *icmpsum;
4387 	u_int8_t	 icmptype;
4388 	int		 state_icmp = 0;
4389 	struct pf_state_key_cmp key;
4390 
4391 	bzero(&key, sizeof(key));
4392 	switch (pd->proto) {
4393 #ifdef INET
4394 	case IPPROTO_ICMP:
4395 		icmptype = pd->hdr.icmp->icmp_type;
4396 		icmpid = pd->hdr.icmp->icmp_id;
4397 		icmpsum = &pd->hdr.icmp->icmp_cksum;
4398 
4399 		if (icmptype == ICMP_UNREACH ||
4400 		    icmptype == ICMP_SOURCEQUENCH ||
4401 		    icmptype == ICMP_REDIRECT ||
4402 		    icmptype == ICMP_TIMXCEED ||
4403 		    icmptype == ICMP_PARAMPROB)
4404 			state_icmp++;
4405 		break;
4406 #endif /* INET */
4407 #ifdef INET6
4408 	case IPPROTO_ICMPV6:
4409 		icmptype = pd->hdr.icmp6->icmp6_type;
4410 		icmpid = pd->hdr.icmp6->icmp6_id;
4411 		icmpsum = &pd->hdr.icmp6->icmp6_cksum;
4412 
4413 		if (icmptype == ICMP6_DST_UNREACH ||
4414 		    icmptype == ICMP6_PACKET_TOO_BIG ||
4415 		    icmptype == ICMP6_TIME_EXCEEDED ||
4416 		    icmptype == ICMP6_PARAM_PROB)
4417 			state_icmp++;
4418 		break;
4419 #endif /* INET6 */
4420 	}
4421 
4422 	if (!state_icmp) {
4423 
4424 		/*
4425 		 * ICMP query/reply message not related to a TCP/UDP packet.
4426 		 * Search for an ICMP state.
4427 		 */
4428 		key.af = pd->af;
4429 		key.proto = pd->proto;
4430 		key.port[0] = key.port[1] = icmpid;
4431 		if (direction == PF_IN)	{	/* wire side, straight */
4432 			PF_ACPY(&key.addr[0], pd->src, key.af);
4433 			PF_ACPY(&key.addr[1], pd->dst, key.af);
4434 		} else {			/* stack side, reverse */
4435 			PF_ACPY(&key.addr[1], pd->src, key.af);
4436 			PF_ACPY(&key.addr[0], pd->dst, key.af);
4437 		}
4438 
4439 		STATE_LOOKUP(kif, &key, direction, *state, pd);
4440 
4441 		(*state)->expire = time_uptime;
4442 		(*state)->timeout = PFTM_ICMP_ERROR_REPLY;
4443 
4444 		/* translate source/destination address, if necessary */
4445 		if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
4446 			struct pf_state_key *nk = (*state)->key[pd->didx];
4447 
4448 			switch (pd->af) {
4449 #ifdef INET
4450 			case AF_INET:
4451 				if (PF_ANEQ(pd->src,
4452 				    &nk->addr[pd->sidx], AF_INET))
4453 					pf_change_a(&saddr->v4.s_addr,
4454 					    pd->ip_sum,
4455 					    nk->addr[pd->sidx].v4.s_addr, 0);
4456 
4457 				if (PF_ANEQ(pd->dst, &nk->addr[pd->didx],
4458 				    AF_INET))
4459 					pf_change_a(&daddr->v4.s_addr,
4460 					    pd->ip_sum,
4461 					    nk->addr[pd->didx].v4.s_addr, 0);
4462 
4463 				if (nk->port[0] !=
4464 				    pd->hdr.icmp->icmp_id) {
4465 					pd->hdr.icmp->icmp_cksum =
4466 					    pf_cksum_fixup(
4467 					    pd->hdr.icmp->icmp_cksum, icmpid,
4468 					    nk->port[pd->sidx], 0);
4469 					pd->hdr.icmp->icmp_id =
4470 					    nk->port[pd->sidx];
4471 				}
4472 
4473 				m_copyback(m, off, ICMP_MINLEN,
4474 				    (caddr_t )pd->hdr.icmp);
4475 				break;
4476 #endif /* INET */
4477 #ifdef INET6
4478 			case AF_INET6:
4479 				if (PF_ANEQ(pd->src,
4480 				    &nk->addr[pd->sidx], AF_INET6))
4481 					pf_change_a6(saddr,
4482 					    &pd->hdr.icmp6->icmp6_cksum,
4483 					    &nk->addr[pd->sidx], 0);
4484 
4485 				if (PF_ANEQ(pd->dst,
4486 				    &nk->addr[pd->didx], AF_INET6))
4487 					pf_change_a6(daddr,
4488 					    &pd->hdr.icmp6->icmp6_cksum,
4489 					    &nk->addr[pd->didx], 0);
4490 
4491 				m_copyback(m, off, sizeof(struct icmp6_hdr),
4492 				    (caddr_t )pd->hdr.icmp6);
4493 				break;
4494 #endif /* INET6 */
4495 			}
4496 		}
4497 		return (PF_PASS);
4498 
4499 	} else {
4500 		/*
4501 		 * ICMP error message in response to a TCP/UDP packet.
4502 		 * Extract the inner TCP/UDP header and search for that state.
4503 		 */
4504 
4505 		struct pf_pdesc	pd2;
4506 		bzero(&pd2, sizeof pd2);
4507 #ifdef INET
4508 		struct ip	h2;
4509 #endif /* INET */
4510 #ifdef INET6
4511 		struct ip6_hdr	h2_6;
4512 		int		terminal = 0;
4513 #endif /* INET6 */
4514 		int		ipoff2 = 0;
4515 		int		off2 = 0;
4516 
4517 		pd2.af = pd->af;
4518 		/* Payload packet is from the opposite direction. */
4519 		pd2.sidx = (direction == PF_IN) ? 1 : 0;
4520 		pd2.didx = (direction == PF_IN) ? 0 : 1;
4521 		switch (pd->af) {
4522 #ifdef INET
4523 		case AF_INET:
4524 			/* offset of h2 in mbuf chain */
4525 			ipoff2 = off + ICMP_MINLEN;
4526 
4527 			if (!pf_pull_hdr(m, ipoff2, &h2, sizeof(h2),
4528 			    NULL, reason, pd2.af)) {
4529 				DPFPRINTF(PF_DEBUG_MISC,
4530 				    ("pf: ICMP error message too short "
4531 				    "(ip)\n"));
4532 				return (PF_DROP);
4533 			}
4534 			/*
4535 			 * ICMP error messages don't refer to non-first
4536 			 * fragments
4537 			 */
4538 			if (h2.ip_off & htons(IP_OFFMASK)) {
4539 				REASON_SET(reason, PFRES_FRAG);
4540 				return (PF_DROP);
4541 			}
4542 
4543 			/* offset of protocol header that follows h2 */
4544 			off2 = ipoff2 + (h2.ip_hl << 2);
4545 
4546 			pd2.proto = h2.ip_p;
4547 			pd2.src = (struct pf_addr *)&h2.ip_src;
4548 			pd2.dst = (struct pf_addr *)&h2.ip_dst;
4549 			pd2.ip_sum = &h2.ip_sum;
4550 			break;
4551 #endif /* INET */
4552 #ifdef INET6
4553 		case AF_INET6:
4554 			ipoff2 = off + sizeof(struct icmp6_hdr);
4555 
4556 			if (!pf_pull_hdr(m, ipoff2, &h2_6, sizeof(h2_6),
4557 			    NULL, reason, pd2.af)) {
4558 				DPFPRINTF(PF_DEBUG_MISC,
4559 				    ("pf: ICMP error message too short "
4560 				    "(ip6)\n"));
4561 				return (PF_DROP);
4562 			}
4563 			pd2.proto = h2_6.ip6_nxt;
4564 			pd2.src = (struct pf_addr *)&h2_6.ip6_src;
4565 			pd2.dst = (struct pf_addr *)&h2_6.ip6_dst;
4566 			pd2.ip_sum = NULL;
4567 			off2 = ipoff2 + sizeof(h2_6);
4568 			do {
4569 				switch (pd2.proto) {
4570 				case IPPROTO_FRAGMENT:
4571 					/*
4572 					 * ICMPv6 error messages for
4573 					 * non-first fragments
4574 					 */
4575 					REASON_SET(reason, PFRES_FRAG);
4576 					return (PF_DROP);
4577 				case IPPROTO_AH:
4578 				case IPPROTO_HOPOPTS:
4579 				case IPPROTO_ROUTING:
4580 				case IPPROTO_DSTOPTS: {
4581 					/* get next header and header length */
4582 					struct ip6_ext opt6;
4583 
4584 					if (!pf_pull_hdr(m, off2, &opt6,
4585 					    sizeof(opt6), NULL, reason,
4586 					    pd2.af)) {
4587 						DPFPRINTF(PF_DEBUG_MISC,
4588 						    ("pf: ICMPv6 short opt\n"));
4589 						return (PF_DROP);
4590 					}
4591 					if (pd2.proto == IPPROTO_AH)
4592 						off2 += (opt6.ip6e_len + 2) * 4;
4593 					else
4594 						off2 += (opt6.ip6e_len + 1) * 8;
4595 					pd2.proto = opt6.ip6e_nxt;
4596 					/* goto the next header */
4597 					break;
4598 				}
4599 				default:
4600 					terminal++;
4601 					break;
4602 				}
4603 			} while (!terminal);
4604 			break;
4605 #endif /* INET6 */
4606 		}
4607 
4608 		switch (pd2.proto) {
4609 		case IPPROTO_TCP: {
4610 			struct tcphdr		 th;
4611 			u_int32_t		 seq;
4612 			struct pf_state_peer	*src, *dst;
4613 			u_int8_t		 dws;
4614 			int			 copyback = 0;
4615 
4616 			/*
4617 			 * Only the first 8 bytes of the TCP header can be
4618 			 * expected. Don't access any TCP header fields after
4619 			 * th_seq, an ackskew test is not possible.
4620 			 */
4621 			if (!pf_pull_hdr(m, off2, &th, 8, NULL, reason,
4622 			    pd2.af)) {
4623 				DPFPRINTF(PF_DEBUG_MISC,
4624 				    ("pf: ICMP error message too short "
4625 				    "(tcp)\n"));
4626 				return (PF_DROP);
4627 			}
4628 
4629 			key.af = pd2.af;
4630 			key.proto = IPPROTO_TCP;
4631 			PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
4632 			PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
4633 			key.port[pd2.sidx] = th.th_sport;
4634 			key.port[pd2.didx] = th.th_dport;
4635 
4636 			STATE_LOOKUP(kif, &key, direction, *state, pd);
4637 
4638 			if (direction == (*state)->direction) {
4639 				src = &(*state)->dst;
4640 				dst = &(*state)->src;
4641 			} else {
4642 				src = &(*state)->src;
4643 				dst = &(*state)->dst;
4644 			}
4645 
4646 			if (src->wscale && dst->wscale)
4647 				dws = dst->wscale & PF_WSCALE_MASK;
4648 			else
4649 				dws = 0;
4650 
4651 			/* Demodulate sequence number */
4652 			seq = ntohl(th.th_seq) - src->seqdiff;
4653 			if (src->seqdiff) {
4654 				pf_change_a(&th.th_seq, icmpsum,
4655 				    htonl(seq), 0);
4656 				copyback = 1;
4657 			}
4658 
4659 			if (!((*state)->state_flags & PFSTATE_SLOPPY) &&
4660 			    (!SEQ_GEQ(src->seqhi, seq) ||
4661 			    !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) {
4662 				if (V_pf_status.debug >= PF_DEBUG_MISC) {
4663 					printf("pf: BAD ICMP %d:%d ",
4664 					    icmptype, pd->hdr.icmp->icmp_code);
4665 					pf_print_host(pd->src, 0, pd->af);
4666 					printf(" -> ");
4667 					pf_print_host(pd->dst, 0, pd->af);
4668 					printf(" state: ");
4669 					pf_print_state(*state);
4670 					printf(" seq=%u\n", seq);
4671 				}
4672 				REASON_SET(reason, PFRES_BADSTATE);
4673 				return (PF_DROP);
4674 			} else {
4675 				if (V_pf_status.debug >= PF_DEBUG_MISC) {
4676 					printf("pf: OK ICMP %d:%d ",
4677 					    icmptype, pd->hdr.icmp->icmp_code);
4678 					pf_print_host(pd->src, 0, pd->af);
4679 					printf(" -> ");
4680 					pf_print_host(pd->dst, 0, pd->af);
4681 					printf(" state: ");
4682 					pf_print_state(*state);
4683 					printf(" seq=%u\n", seq);
4684 				}
4685 			}
4686 
4687 			/* translate source/destination address, if necessary */
4688 			if ((*state)->key[PF_SK_WIRE] !=
4689 			    (*state)->key[PF_SK_STACK]) {
4690 				struct pf_state_key *nk =
4691 				    (*state)->key[pd->didx];
4692 
4693 				if (PF_ANEQ(pd2.src,
4694 				    &nk->addr[pd2.sidx], pd2.af) ||
4695 				    nk->port[pd2.sidx] != th.th_sport)
4696 					pf_change_icmp(pd2.src, &th.th_sport,
4697 					    daddr, &nk->addr[pd2.sidx],
4698 					    nk->port[pd2.sidx], NULL,
4699 					    pd2.ip_sum, icmpsum,
4700 					    pd->ip_sum, 0, pd2.af);
4701 
4702 				if (PF_ANEQ(pd2.dst,
4703 				    &nk->addr[pd2.didx], pd2.af) ||
4704 				    nk->port[pd2.didx] != th.th_dport)
4705 					pf_change_icmp(pd2.dst, &th.th_dport,
4706 					    NULL, /* XXX Inbound NAT? */
4707 					    &nk->addr[pd2.didx],
4708 					    nk->port[pd2.didx], NULL,
4709 					    pd2.ip_sum, icmpsum,
4710 					    pd->ip_sum, 0, pd2.af);
4711 				copyback = 1;
4712 			}
4713 
4714 			if (copyback) {
4715 				switch (pd2.af) {
4716 #ifdef INET
4717 				case AF_INET:
4718 					m_copyback(m, off, ICMP_MINLEN,
4719 					    (caddr_t )pd->hdr.icmp);
4720 					m_copyback(m, ipoff2, sizeof(h2),
4721 					    (caddr_t )&h2);
4722 					break;
4723 #endif /* INET */
4724 #ifdef INET6
4725 				case AF_INET6:
4726 					m_copyback(m, off,
4727 					    sizeof(struct icmp6_hdr),
4728 					    (caddr_t )pd->hdr.icmp6);
4729 					m_copyback(m, ipoff2, sizeof(h2_6),
4730 					    (caddr_t )&h2_6);
4731 					break;
4732 #endif /* INET6 */
4733 				}
4734 				m_copyback(m, off2, 8, (caddr_t)&th);
4735 			}
4736 
4737 			return (PF_PASS);
4738 			break;
4739 		}
4740 		case IPPROTO_UDP: {
4741 			struct udphdr		uh;
4742 
4743 			if (!pf_pull_hdr(m, off2, &uh, sizeof(uh),
4744 			    NULL, reason, pd2.af)) {
4745 				DPFPRINTF(PF_DEBUG_MISC,
4746 				    ("pf: ICMP error message too short "
4747 				    "(udp)\n"));
4748 				return (PF_DROP);
4749 			}
4750 
4751 			key.af = pd2.af;
4752 			key.proto = IPPROTO_UDP;
4753 			PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
4754 			PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
4755 			key.port[pd2.sidx] = uh.uh_sport;
4756 			key.port[pd2.didx] = uh.uh_dport;
4757 
4758 			STATE_LOOKUP(kif, &key, direction, *state, pd);
4759 
4760 			/* translate source/destination address, if necessary */
4761 			if ((*state)->key[PF_SK_WIRE] !=
4762 			    (*state)->key[PF_SK_STACK]) {
4763 				struct pf_state_key *nk =
4764 				    (*state)->key[pd->didx];
4765 
4766 				if (PF_ANEQ(pd2.src,
4767 				    &nk->addr[pd2.sidx], pd2.af) ||
4768 				    nk->port[pd2.sidx] != uh.uh_sport)
4769 					pf_change_icmp(pd2.src, &uh.uh_sport,
4770 					    daddr, &nk->addr[pd2.sidx],
4771 					    nk->port[pd2.sidx], &uh.uh_sum,
4772 					    pd2.ip_sum, icmpsum,
4773 					    pd->ip_sum, 1, pd2.af);
4774 
4775 				if (PF_ANEQ(pd2.dst,
4776 				    &nk->addr[pd2.didx], pd2.af) ||
4777 				    nk->port[pd2.didx] != uh.uh_dport)
4778 					pf_change_icmp(pd2.dst, &uh.uh_dport,
4779 					    NULL, /* XXX Inbound NAT? */
4780 					    &nk->addr[pd2.didx],
4781 					    nk->port[pd2.didx], &uh.uh_sum,
4782 					    pd2.ip_sum, icmpsum,
4783 					    pd->ip_sum, 1, pd2.af);
4784 
4785 				switch (pd2.af) {
4786 #ifdef INET
4787 				case AF_INET:
4788 					m_copyback(m, off, ICMP_MINLEN,
4789 					    (caddr_t )pd->hdr.icmp);
4790 					m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
4791 					break;
4792 #endif /* INET */
4793 #ifdef INET6
4794 				case AF_INET6:
4795 					m_copyback(m, off,
4796 					    sizeof(struct icmp6_hdr),
4797 					    (caddr_t )pd->hdr.icmp6);
4798 					m_copyback(m, ipoff2, sizeof(h2_6),
4799 					    (caddr_t )&h2_6);
4800 					break;
4801 #endif /* INET6 */
4802 				}
4803 				m_copyback(m, off2, sizeof(uh), (caddr_t)&uh);
4804 			}
4805 			return (PF_PASS);
4806 			break;
4807 		}
4808 #ifdef INET
4809 		case IPPROTO_ICMP: {
4810 			struct icmp		iih;
4811 
4812 			if (!pf_pull_hdr(m, off2, &iih, ICMP_MINLEN,
4813 			    NULL, reason, pd2.af)) {
4814 				DPFPRINTF(PF_DEBUG_MISC,
4815 				    ("pf: ICMP error message too short i"
4816 				    "(icmp)\n"));
4817 				return (PF_DROP);
4818 			}
4819 
4820 			key.af = pd2.af;
4821 			key.proto = IPPROTO_ICMP;
4822 			PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
4823 			PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
4824 			key.port[0] = key.port[1] = iih.icmp_id;
4825 
4826 			STATE_LOOKUP(kif, &key, direction, *state, pd);
4827 
4828 			/* translate source/destination address, if necessary */
4829 			if ((*state)->key[PF_SK_WIRE] !=
4830 			    (*state)->key[PF_SK_STACK]) {
4831 				struct pf_state_key *nk =
4832 				    (*state)->key[pd->didx];
4833 
4834 				if (PF_ANEQ(pd2.src,
4835 				    &nk->addr[pd2.sidx], pd2.af) ||
4836 				    nk->port[pd2.sidx] != iih.icmp_id)
4837 					pf_change_icmp(pd2.src, &iih.icmp_id,
4838 					    daddr, &nk->addr[pd2.sidx],
4839 					    nk->port[pd2.sidx], NULL,
4840 					    pd2.ip_sum, icmpsum,
4841 					    pd->ip_sum, 0, AF_INET);
4842 
4843 				if (PF_ANEQ(pd2.dst,
4844 				    &nk->addr[pd2.didx], pd2.af) ||
4845 				    nk->port[pd2.didx] != iih.icmp_id)
4846 					pf_change_icmp(pd2.dst, &iih.icmp_id,
4847 					    NULL, /* XXX Inbound NAT? */
4848 					    &nk->addr[pd2.didx],
4849 					    nk->port[pd2.didx], NULL,
4850 					    pd2.ip_sum, icmpsum,
4851 					    pd->ip_sum, 0, AF_INET);
4852 
4853 				m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp);
4854 				m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
4855 				m_copyback(m, off2, ICMP_MINLEN, (caddr_t)&iih);
4856 			}
4857 			return (PF_PASS);
4858 			break;
4859 		}
4860 #endif /* INET */
4861 #ifdef INET6
4862 		case IPPROTO_ICMPV6: {
4863 			struct icmp6_hdr	iih;
4864 
4865 			if (!pf_pull_hdr(m, off2, &iih,
4866 			    sizeof(struct icmp6_hdr), NULL, reason, pd2.af)) {
4867 				DPFPRINTF(PF_DEBUG_MISC,
4868 				    ("pf: ICMP error message too short "
4869 				    "(icmp6)\n"));
4870 				return (PF_DROP);
4871 			}
4872 
4873 			key.af = pd2.af;
4874 			key.proto = IPPROTO_ICMPV6;
4875 			PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
4876 			PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
4877 			key.port[0] = key.port[1] = iih.icmp6_id;
4878 
4879 			STATE_LOOKUP(kif, &key, direction, *state, pd);
4880 
4881 			/* translate source/destination address, if necessary */
4882 			if ((*state)->key[PF_SK_WIRE] !=
4883 			    (*state)->key[PF_SK_STACK]) {
4884 				struct pf_state_key *nk =
4885 				    (*state)->key[pd->didx];
4886 
4887 				if (PF_ANEQ(pd2.src,
4888 				    &nk->addr[pd2.sidx], pd2.af) ||
4889 				    nk->port[pd2.sidx] != iih.icmp6_id)
4890 					pf_change_icmp(pd2.src, &iih.icmp6_id,
4891 					    daddr, &nk->addr[pd2.sidx],
4892 					    nk->port[pd2.sidx], NULL,
4893 					    pd2.ip_sum, icmpsum,
4894 					    pd->ip_sum, 0, AF_INET6);
4895 
4896 				if (PF_ANEQ(pd2.dst,
4897 				    &nk->addr[pd2.didx], pd2.af) ||
4898 				    nk->port[pd2.didx] != iih.icmp6_id)
4899 					pf_change_icmp(pd2.dst, &iih.icmp6_id,
4900 					    NULL, /* XXX Inbound NAT? */
4901 					    &nk->addr[pd2.didx],
4902 					    nk->port[pd2.didx], NULL,
4903 					    pd2.ip_sum, icmpsum,
4904 					    pd->ip_sum, 0, AF_INET6);
4905 
4906 				m_copyback(m, off, sizeof(struct icmp6_hdr),
4907 				    (caddr_t)pd->hdr.icmp6);
4908 				m_copyback(m, ipoff2, sizeof(h2_6), (caddr_t)&h2_6);
4909 				m_copyback(m, off2, sizeof(struct icmp6_hdr),
4910 				    (caddr_t)&iih);
4911 			}
4912 			return (PF_PASS);
4913 			break;
4914 		}
4915 #endif /* INET6 */
4916 		default: {
4917 			key.af = pd2.af;
4918 			key.proto = pd2.proto;
4919 			PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
4920 			PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
4921 			key.port[0] = key.port[1] = 0;
4922 
4923 			STATE_LOOKUP(kif, &key, direction, *state, pd);
4924 
4925 			/* translate source/destination address, if necessary */
4926 			if ((*state)->key[PF_SK_WIRE] !=
4927 			    (*state)->key[PF_SK_STACK]) {
4928 				struct pf_state_key *nk =
4929 				    (*state)->key[pd->didx];
4930 
4931 				if (PF_ANEQ(pd2.src,
4932 				    &nk->addr[pd2.sidx], pd2.af))
4933 					pf_change_icmp(pd2.src, NULL, daddr,
4934 					    &nk->addr[pd2.sidx], 0, NULL,
4935 					    pd2.ip_sum, icmpsum,
4936 					    pd->ip_sum, 0, pd2.af);
4937 
4938 				if (PF_ANEQ(pd2.dst,
4939 				    &nk->addr[pd2.didx], pd2.af))
4940 					pf_change_icmp(pd2.src, NULL,
4941 					    NULL, /* XXX Inbound NAT? */
4942 					    &nk->addr[pd2.didx], 0, NULL,
4943 					    pd2.ip_sum, icmpsum,
4944 					    pd->ip_sum, 0, pd2.af);
4945 
4946 				switch (pd2.af) {
4947 #ifdef INET
4948 				case AF_INET:
4949 					m_copyback(m, off, ICMP_MINLEN,
4950 					    (caddr_t)pd->hdr.icmp);
4951 					m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
4952 					break;
4953 #endif /* INET */
4954 #ifdef INET6
4955 				case AF_INET6:
4956 					m_copyback(m, off,
4957 					    sizeof(struct icmp6_hdr),
4958 					    (caddr_t )pd->hdr.icmp6);
4959 					m_copyback(m, ipoff2, sizeof(h2_6),
4960 					    (caddr_t )&h2_6);
4961 					break;
4962 #endif /* INET6 */
4963 				}
4964 			}
4965 			return (PF_PASS);
4966 			break;
4967 		}
4968 		}
4969 	}
4970 }
4971 
4972 static int
pf_test_state_other(struct pf_state ** state,int direction,struct pfi_kif * kif,struct mbuf * m,struct pf_pdesc * pd)4973 pf_test_state_other(struct pf_state **state, int direction, struct pfi_kif *kif,
4974     struct mbuf *m, struct pf_pdesc *pd)
4975 {
4976 	struct pf_state_peer	*src, *dst;
4977 	struct pf_state_key_cmp	 key;
4978 
4979 	bzero(&key, sizeof(key));
4980 	key.af = pd->af;
4981 	key.proto = pd->proto;
4982 	if (direction == PF_IN)	{
4983 		PF_ACPY(&key.addr[0], pd->src, key.af);
4984 		PF_ACPY(&key.addr[1], pd->dst, key.af);
4985 		key.port[0] = key.port[1] = 0;
4986 	} else {
4987 		PF_ACPY(&key.addr[1], pd->src, key.af);
4988 		PF_ACPY(&key.addr[0], pd->dst, key.af);
4989 		key.port[1] = key.port[0] = 0;
4990 	}
4991 
4992 	STATE_LOOKUP(kif, &key, direction, *state, pd);
4993 
4994 	if (direction == (*state)->direction) {
4995 		src = &(*state)->src;
4996 		dst = &(*state)->dst;
4997 	} else {
4998 		src = &(*state)->dst;
4999 		dst = &(*state)->src;
5000 	}
5001 
5002 	/* update states */
5003 	if (src->state < PFOTHERS_SINGLE)
5004 		src->state = PFOTHERS_SINGLE;
5005 	if (dst->state == PFOTHERS_SINGLE)
5006 		dst->state = PFOTHERS_MULTIPLE;
5007 
5008 	/* update expire time */
5009 	(*state)->expire = time_uptime;
5010 	if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE)
5011 		(*state)->timeout = PFTM_OTHER_MULTIPLE;
5012 	else
5013 		(*state)->timeout = PFTM_OTHER_SINGLE;
5014 
5015 	/* translate source/destination address, if necessary */
5016 	if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
5017 		struct pf_state_key *nk = (*state)->key[pd->didx];
5018 
5019 		KASSERT(nk, ("%s: nk is null", __func__));
5020 		KASSERT(pd, ("%s: pd is null", __func__));
5021 		KASSERT(pd->src, ("%s: pd->src is null", __func__));
5022 		KASSERT(pd->dst, ("%s: pd->dst is null", __func__));
5023 		switch (pd->af) {
5024 #ifdef INET
5025 		case AF_INET:
5026 			if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET))
5027 				pf_change_a(&pd->src->v4.s_addr,
5028 				    pd->ip_sum,
5029 				    nk->addr[pd->sidx].v4.s_addr,
5030 				    0);
5031 
5032 
5033 			if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET))
5034 				pf_change_a(&pd->dst->v4.s_addr,
5035 				    pd->ip_sum,
5036 				    nk->addr[pd->didx].v4.s_addr,
5037 				    0);
5038 
5039 				break;
5040 #endif /* INET */
5041 #ifdef INET6
5042 		case AF_INET6:
5043 			if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET))
5044 				PF_ACPY(pd->src, &nk->addr[pd->sidx], pd->af);
5045 
5046 			if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET))
5047 				PF_ACPY(pd->dst, &nk->addr[pd->didx], pd->af);
5048 #endif /* INET6 */
5049 		}
5050 	}
5051 	return (PF_PASS);
5052 }
5053 
5054 /*
5055  * ipoff and off are measured from the start of the mbuf chain.
5056  * h must be at "ipoff" on the mbuf chain.
5057  */
5058 void *
pf_pull_hdr(struct mbuf * m,int off,void * p,int len,u_short * actionp,u_short * reasonp,sa_family_t af)5059 pf_pull_hdr(struct mbuf *m, int off, void *p, int len,
5060     u_short *actionp, u_short *reasonp, sa_family_t af)
5061 {
5062 	switch (af) {
5063 #ifdef INET
5064 	case AF_INET: {
5065 		struct ip	*h = mtod(m, struct ip *);
5066 		u_int16_t	 fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3;
5067 
5068 		if (fragoff) {
5069 			if (fragoff >= len)
5070 				ACTION_SET(actionp, PF_PASS);
5071 			else {
5072 				ACTION_SET(actionp, PF_DROP);
5073 				REASON_SET(reasonp, PFRES_FRAG);
5074 			}
5075 			return (NULL);
5076 		}
5077 		if (m->m_pkthdr.len < off + len ||
5078 		    ntohs(h->ip_len) < off + len) {
5079 			ACTION_SET(actionp, PF_DROP);
5080 			REASON_SET(reasonp, PFRES_SHORT);
5081 			return (NULL);
5082 		}
5083 		break;
5084 	}
5085 #endif /* INET */
5086 #ifdef INET6
5087 	case AF_INET6: {
5088 		struct ip6_hdr	*h = mtod(m, struct ip6_hdr *);
5089 
5090 		if (m->m_pkthdr.len < off + len ||
5091 		    (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) <
5092 		    (unsigned)(off + len)) {
5093 			ACTION_SET(actionp, PF_DROP);
5094 			REASON_SET(reasonp, PFRES_SHORT);
5095 			return (NULL);
5096 		}
5097 		break;
5098 	}
5099 #endif /* INET6 */
5100 	}
5101 	m_copydata(m, off, len, p);
5102 	return (p);
5103 }
5104 
5105 int
pf_routable(struct pf_addr * addr,sa_family_t af,struct pfi_kif * kif,int rtableid)5106 pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif,
5107     int rtableid)
5108 {
5109 #ifdef RADIX_MPATH
5110 	struct radix_node_head	*rnh;
5111 #endif
5112 	struct sockaddr_in	*dst;
5113 	int			 ret = 1;
5114 	int			 check_mpath;
5115 #ifdef INET6
5116 	struct sockaddr_in6	*dst6;
5117 	struct route_in6	 ro;
5118 #else
5119 	struct route		 ro;
5120 #endif
5121 	struct radix_node	*rn;
5122 	struct rtentry		*rt;
5123 	struct ifnet		*ifp;
5124 
5125 	check_mpath = 0;
5126 #ifdef RADIX_MPATH
5127 	/* XXX: stick to table 0 for now */
5128 	rnh = rt_tables_get_rnh(0, af);
5129 	if (rnh != NULL && rn_mpath_capable(rnh))
5130 		check_mpath = 1;
5131 #endif
5132 	bzero(&ro, sizeof(ro));
5133 	switch (af) {
5134 	case AF_INET:
5135 		dst = satosin(&ro.ro_dst);
5136 		dst->sin_family = AF_INET;
5137 		dst->sin_len = sizeof(*dst);
5138 		dst->sin_addr = addr->v4;
5139 		break;
5140 #ifdef INET6
5141 	case AF_INET6:
5142 		/*
5143 		 * Skip check for addresses with embedded interface scope,
5144 		 * as they would always match anyway.
5145 		 */
5146 		if (IN6_IS_SCOPE_EMBED(&addr->v6))
5147 			goto out;
5148 		dst6 = (struct sockaddr_in6 *)&ro.ro_dst;
5149 		dst6->sin6_family = AF_INET6;
5150 		dst6->sin6_len = sizeof(*dst6);
5151 		dst6->sin6_addr = addr->v6;
5152 		break;
5153 #endif /* INET6 */
5154 	default:
5155 		return (0);
5156 	}
5157 
5158 	/* Skip checks for ipsec interfaces */
5159 	if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC)
5160 		goto out;
5161 
5162 	switch (af) {
5163 #ifdef INET6
5164 	case AF_INET6:
5165 		in6_rtalloc_ign(&ro, 0, rtableid);
5166 		break;
5167 #endif
5168 #ifdef INET
5169 	case AF_INET:
5170 		in_rtalloc_ign((struct route *)&ro, 0, rtableid);
5171 		break;
5172 #endif
5173 	default:
5174 		rtalloc_ign((struct route *)&ro, 0);	/* No/default FIB. */
5175 		break;
5176 	}
5177 
5178 	if (ro.ro_rt != NULL) {
5179 		/* No interface given, this is a no-route check */
5180 		if (kif == NULL)
5181 			goto out;
5182 
5183 		if (kif->pfik_ifp == NULL) {
5184 			ret = 0;
5185 			goto out;
5186 		}
5187 
5188 		/* Perform uRPF check if passed input interface */
5189 		ret = 0;
5190 		rn = (struct radix_node *)ro.ro_rt;
5191 		do {
5192 			rt = (struct rtentry *)rn;
5193 			ifp = rt->rt_ifp;
5194 
5195 			if (kif->pfik_ifp == ifp)
5196 				ret = 1;
5197 #ifdef RADIX_MPATH
5198 			rn = rn_mpath_next(rn);
5199 #endif
5200 		} while (check_mpath == 1 && rn != NULL && ret == 0);
5201 	} else
5202 		ret = 0;
5203 out:
5204 	if (ro.ro_rt != NULL)
5205 		RTFREE(ro.ro_rt);
5206 	return (ret);
5207 }
5208 
5209 #ifdef INET
5210 static void
pf_route(struct mbuf ** m,struct pf_rule * r,int dir,struct ifnet * oifp,struct pf_state * s,struct pf_pdesc * pd)5211 pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
5212     struct pf_state *s, struct pf_pdesc *pd)
5213 {
5214 	struct mbuf		*m0, *m1;
5215 	struct sockaddr_in	dst;
5216 	struct ip		*ip;
5217 	struct ifnet		*ifp = NULL;
5218 	struct pf_addr		 naddr;
5219 	struct pf_src_node	*sn = NULL;
5220 	int			 error = 0;
5221 	uint16_t		 ip_len, ip_off;
5222 
5223 	KASSERT(m && *m && r && oifp, ("%s: invalid parameters", __func__));
5224 	KASSERT(dir == PF_IN || dir == PF_OUT, ("%s: invalid direction",
5225 	    __func__));
5226 
5227 	if ((pd->pf_mtag == NULL &&
5228 	    ((pd->pf_mtag = pf_get_mtag(*m)) == NULL)) ||
5229 	    pd->pf_mtag->routed++ > 3) {
5230 		m0 = *m;
5231 		*m = NULL;
5232 		goto bad_locked;
5233 	}
5234 
5235 	if (r->rt == PF_DUPTO) {
5236 		if ((m0 = m_dup(*m, M_NOWAIT)) == NULL) {
5237 			if (s)
5238 				PF_STATE_UNLOCK(s);
5239 			return;
5240 		}
5241 	} else {
5242 		if ((r->rt == PF_REPLYTO) == (r->direction == dir)) {
5243 			if (s)
5244 				PF_STATE_UNLOCK(s);
5245 			return;
5246 		}
5247 		m0 = *m;
5248 	}
5249 
5250 	ip = mtod(m0, struct ip *);
5251 
5252 	bzero(&dst, sizeof(dst));
5253 	dst.sin_family = AF_INET;
5254 	dst.sin_len = sizeof(dst);
5255 	dst.sin_addr = ip->ip_dst;
5256 
5257 	if (r->rt == PF_FASTROUTE) {
5258 		struct rtentry *rt;
5259 
5260 		if (s)
5261 			PF_STATE_UNLOCK(s);
5262 		rt = rtalloc1_fib(sintosa(&dst), 0, 0, M_GETFIB(m0));
5263 		if (rt == NULL) {
5264 			KMOD_IPSTAT_INC(ips_noroute);
5265 			error = EHOSTUNREACH;
5266 			goto bad;
5267 		}
5268 
5269 		ifp = rt->rt_ifp;
5270 		counter_u64_add(rt->rt_pksent, 1);
5271 
5272 		if (rt->rt_flags & RTF_GATEWAY)
5273 			bcopy(satosin(rt->rt_gateway), &dst, sizeof(dst));
5274 		RTFREE_LOCKED(rt);
5275 	} else {
5276 		if (TAILQ_EMPTY(&r->rpool.list)) {
5277 			DPFPRINTF(PF_DEBUG_URGENT,
5278 			    ("%s: TAILQ_EMPTY(&r->rpool.list)\n", __func__));
5279 			goto bad_locked;
5280 		}
5281 		if (s == NULL) {
5282 			pf_map_addr(AF_INET, r, (struct pf_addr *)&ip->ip_src,
5283 			    &naddr, NULL, &sn);
5284 			if (!PF_AZERO(&naddr, AF_INET))
5285 				dst.sin_addr.s_addr = naddr.v4.s_addr;
5286 			ifp = r->rpool.cur->kif ?
5287 			    r->rpool.cur->kif->pfik_ifp : NULL;
5288 		} else {
5289 			if (!PF_AZERO(&s->rt_addr, AF_INET))
5290 				dst.sin_addr.s_addr =
5291 				    s->rt_addr.v4.s_addr;
5292 			ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL;
5293 			PF_STATE_UNLOCK(s);
5294 		}
5295 	}
5296 	if (ifp == NULL)
5297 		goto bad;
5298 
5299 	if (oifp != ifp) {
5300 		if (pf_test(PF_OUT, ifp, &m0, NULL) != PF_PASS)
5301 			goto bad;
5302 		else if (m0 == NULL)
5303 			goto done;
5304 		if (m0->m_len < sizeof(struct ip)) {
5305 			DPFPRINTF(PF_DEBUG_URGENT,
5306 			    ("%s: m0->m_len < sizeof(struct ip)\n", __func__));
5307 			goto bad;
5308 		}
5309 		ip = mtod(m0, struct ip *);
5310 	}
5311 
5312 	if (ifp->if_flags & IFF_LOOPBACK)
5313 		m0->m_flags |= M_SKIP_FIREWALL;
5314 
5315 	ip_len = ntohs(ip->ip_len);
5316 	ip_off = ntohs(ip->ip_off);
5317 
5318 	/* Copied from FreeBSD 10.0-CURRENT ip_output. */
5319 	m0->m_pkthdr.csum_flags |= CSUM_IP;
5320 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
5321 		in_delayed_cksum(m0);
5322 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
5323 	}
5324 #ifdef SCTP
5325 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
5326 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
5327 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
5328 	}
5329 #endif
5330 
5331 	/*
5332 	 * If small enough for interface, or the interface will take
5333 	 * care of the fragmentation for us, we can just send directly.
5334 	 */
5335 	if (ip_len <= ifp->if_mtu ||
5336 	    (m0->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
5337 	    ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
5338 		ip->ip_sum = 0;
5339 		if (m0->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
5340 			ip->ip_sum = in_cksum(m0, ip->ip_hl << 2);
5341 			m0->m_pkthdr.csum_flags &= ~CSUM_IP;
5342 		}
5343 		m_clrprotoflags(m0);	/* Avoid confusing lower layers. */
5344 		error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
5345 		goto done;
5346 	}
5347 
5348 	/* Balk when DF bit is set or the interface didn't support TSO. */
5349 	if ((ip_off & IP_DF) || (m0->m_pkthdr.csum_flags & CSUM_TSO)) {
5350 		error = EMSGSIZE;
5351 		KMOD_IPSTAT_INC(ips_cantfrag);
5352 		if (r->rt != PF_DUPTO) {
5353 			icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0,
5354 			    ifp->if_mtu);
5355 			goto done;
5356 		} else
5357 			goto bad;
5358 	}
5359 
5360 	error = ip_fragment(ip, &m0, ifp->if_mtu, ifp->if_hwassist);
5361 	if (error)
5362 		goto bad;
5363 
5364 	for (; m0; m0 = m1) {
5365 		m1 = m0->m_nextpkt;
5366 		m0->m_nextpkt = NULL;
5367 		if (error == 0) {
5368 			m_clrprotoflags(m0);
5369 			error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
5370 		} else
5371 			m_freem(m0);
5372 	}
5373 
5374 	if (error == 0)
5375 		KMOD_IPSTAT_INC(ips_fragmented);
5376 
5377 done:
5378 	if (r->rt != PF_DUPTO)
5379 		*m = NULL;
5380 	return;
5381 
5382 bad_locked:
5383 	if (s)
5384 		PF_STATE_UNLOCK(s);
5385 bad:
5386 	m_freem(m0);
5387 	goto done;
5388 }
5389 #endif /* INET */
5390 
5391 #ifdef INET6
5392 static void
pf_route6(struct mbuf ** m,struct pf_rule * r,int dir,struct ifnet * oifp,struct pf_state * s,struct pf_pdesc * pd)5393 pf_route6(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
5394     struct pf_state *s, struct pf_pdesc *pd)
5395 {
5396 	struct mbuf		*m0;
5397 	struct sockaddr_in6	dst;
5398 	struct ip6_hdr		*ip6;
5399 	struct ifnet		*ifp = NULL;
5400 	struct pf_addr		 naddr;
5401 	struct pf_src_node	*sn = NULL;
5402 
5403 	KASSERT(m && *m && r && oifp, ("%s: invalid parameters", __func__));
5404 	KASSERT(dir == PF_IN || dir == PF_OUT, ("%s: invalid direction",
5405 	    __func__));
5406 
5407 	if ((pd->pf_mtag == NULL &&
5408 	    ((pd->pf_mtag = pf_get_mtag(*m)) == NULL)) ||
5409 	    pd->pf_mtag->routed++ > 3) {
5410 		m0 = *m;
5411 		*m = NULL;
5412 		goto bad_locked;
5413 	}
5414 
5415 	if (r->rt == PF_DUPTO) {
5416 		if ((m0 = m_dup(*m, M_NOWAIT)) == NULL) {
5417 			if (s)
5418 				PF_STATE_UNLOCK(s);
5419 			return;
5420 		}
5421 	} else {
5422 		if ((r->rt == PF_REPLYTO) == (r->direction == dir)) {
5423 			if (s)
5424 				PF_STATE_UNLOCK(s);
5425 			return;
5426 		}
5427 		m0 = *m;
5428 	}
5429 
5430 	ip6 = mtod(m0, struct ip6_hdr *);
5431 
5432 	bzero(&dst, sizeof(dst));
5433 	dst.sin6_family = AF_INET6;
5434 	dst.sin6_len = sizeof(dst);
5435 	dst.sin6_addr = ip6->ip6_dst;
5436 
5437 	/* Cheat. XXX why only in the v6 case??? */
5438 	if (r->rt == PF_FASTROUTE) {
5439 		if (s)
5440 			PF_STATE_UNLOCK(s);
5441 		m0->m_flags |= M_SKIP_FIREWALL;
5442 		ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL);
5443 		*m = NULL;
5444 		return;
5445 	}
5446 
5447 	if (TAILQ_EMPTY(&r->rpool.list)) {
5448 		DPFPRINTF(PF_DEBUG_URGENT,
5449 		    ("%s: TAILQ_EMPTY(&r->rpool.list)\n", __func__));
5450 		goto bad_locked;
5451 	}
5452 	if (s == NULL) {
5453 		pf_map_addr(AF_INET6, r, (struct pf_addr *)&ip6->ip6_src,
5454 		    &naddr, NULL, &sn);
5455 		if (!PF_AZERO(&naddr, AF_INET6))
5456 			PF_ACPY((struct pf_addr *)&dst.sin6_addr,
5457 			    &naddr, AF_INET6);
5458 		ifp = r->rpool.cur->kif ? r->rpool.cur->kif->pfik_ifp : NULL;
5459 	} else {
5460 		if (!PF_AZERO(&s->rt_addr, AF_INET6))
5461 			PF_ACPY((struct pf_addr *)&dst.sin6_addr,
5462 			    &s->rt_addr, AF_INET6);
5463 		ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL;
5464 	}
5465 
5466 	if (s)
5467 		PF_STATE_UNLOCK(s);
5468 
5469 	if (ifp == NULL)
5470 		goto bad;
5471 
5472 	if (oifp != ifp) {
5473 		if (pf_test6(PF_OUT, ifp, &m0, NULL) != PF_PASS)
5474 			goto bad;
5475 		else if (m0 == NULL)
5476 			goto done;
5477 		if (m0->m_len < sizeof(struct ip6_hdr)) {
5478 			DPFPRINTF(PF_DEBUG_URGENT,
5479 			    ("%s: m0->m_len < sizeof(struct ip6_hdr)\n",
5480 			    __func__));
5481 			goto bad;
5482 		}
5483 		ip6 = mtod(m0, struct ip6_hdr *);
5484 	}
5485 
5486 	if (ifp->if_flags & IFF_LOOPBACK)
5487 		m0->m_flags |= M_SKIP_FIREWALL;
5488 
5489 	/*
5490 	 * If the packet is too large for the outgoing interface,
5491 	 * send back an icmp6 error.
5492 	 */
5493 	if (IN6_IS_SCOPE_EMBED(&dst.sin6_addr))
5494 		dst.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
5495 	if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu)
5496 		nd6_output(ifp, ifp, m0, &dst, NULL);
5497 	else {
5498 		in6_ifstat_inc(ifp, ifs6_in_toobig);
5499 		if (r->rt != PF_DUPTO)
5500 			icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu);
5501 		else
5502 			goto bad;
5503 	}
5504 
5505 done:
5506 	if (r->rt != PF_DUPTO)
5507 		*m = NULL;
5508 	return;
5509 
5510 bad_locked:
5511 	if (s)
5512 		PF_STATE_UNLOCK(s);
5513 bad:
5514 	m_freem(m0);
5515 	goto done;
5516 }
5517 #endif /* INET6 */
5518 
5519 /*
5520  * FreeBSD supports cksum offloads for the following drivers.
5521  *  em(4), fxp(4), ixgb(4), lge(4), ndis(4), nge(4), re(4),
5522  *   ti(4), txp(4), xl(4)
5523  *
5524  * CSUM_DATA_VALID | CSUM_PSEUDO_HDR :
5525  *  network driver performed cksum including pseudo header, need to verify
5526  *   csum_data
5527  * CSUM_DATA_VALID :
5528  *  network driver performed cksum, needs to additional pseudo header
5529  *  cksum computation with partial csum_data(i.e. lack of H/W support for
5530  *  pseudo header, for instance hme(4), sk(4) and possibly gem(4))
5531  *
5532  * After validating the cksum of packet, set both flag CSUM_DATA_VALID and
5533  * CSUM_PSEUDO_HDR in order to avoid recomputation of the cksum in upper
5534  * TCP/UDP layer.
5535  * Also, set csum_data to 0xffff to force cksum validation.
5536  */
5537 static int
pf_check_proto_cksum(struct mbuf * m,int off,int len,u_int8_t p,sa_family_t af)5538 pf_check_proto_cksum(struct mbuf *m, int off, int len, u_int8_t p, sa_family_t af)
5539 {
5540 	u_int16_t sum = 0;
5541 	int hw_assist = 0;
5542 	struct ip *ip;
5543 
5544 	if (off < sizeof(struct ip) || len < sizeof(struct udphdr))
5545 		return (1);
5546 	if (m->m_pkthdr.len < off + len)
5547 		return (1);
5548 
5549 	switch (p) {
5550 	case IPPROTO_TCP:
5551 		if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
5552 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) {
5553 				sum = m->m_pkthdr.csum_data;
5554 			} else {
5555 				ip = mtod(m, struct ip *);
5556 				sum = in_pseudo(ip->ip_src.s_addr,
5557 				ip->ip_dst.s_addr, htonl((u_short)len +
5558 				m->m_pkthdr.csum_data + IPPROTO_TCP));
5559 			}
5560 			sum ^= 0xffff;
5561 			++hw_assist;
5562 		}
5563 		break;
5564 	case IPPROTO_UDP:
5565 		if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
5566 			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) {
5567 				sum = m->m_pkthdr.csum_data;
5568 			} else {
5569 				ip = mtod(m, struct ip *);
5570 				sum = in_pseudo(ip->ip_src.s_addr,
5571 				ip->ip_dst.s_addr, htonl((u_short)len +
5572 				m->m_pkthdr.csum_data + IPPROTO_UDP));
5573 			}
5574 			sum ^= 0xffff;
5575 			++hw_assist;
5576 		}
5577 		break;
5578 	case IPPROTO_ICMP:
5579 #ifdef INET6
5580 	case IPPROTO_ICMPV6:
5581 #endif /* INET6 */
5582 		break;
5583 	default:
5584 		return (1);
5585 	}
5586 
5587 	if (!hw_assist) {
5588 		switch (af) {
5589 		case AF_INET:
5590 			if (p == IPPROTO_ICMP) {
5591 				if (m->m_len < off)
5592 					return (1);
5593 				m->m_data += off;
5594 				m->m_len -= off;
5595 				sum = in_cksum(m, len);
5596 				m->m_data -= off;
5597 				m->m_len += off;
5598 			} else {
5599 				if (m->m_len < sizeof(struct ip))
5600 					return (1);
5601 				sum = in4_cksum(m, p, off, len);
5602 			}
5603 			break;
5604 #ifdef INET6
5605 		case AF_INET6:
5606 			if (m->m_len < sizeof(struct ip6_hdr))
5607 				return (1);
5608 			sum = in6_cksum(m, p, off, len);
5609 			break;
5610 #endif /* INET6 */
5611 		default:
5612 			return (1);
5613 		}
5614 	}
5615 	if (sum) {
5616 		switch (p) {
5617 		case IPPROTO_TCP:
5618 		    {
5619 			KMOD_TCPSTAT_INC(tcps_rcvbadsum);
5620 			break;
5621 		    }
5622 		case IPPROTO_UDP:
5623 		    {
5624 			KMOD_UDPSTAT_INC(udps_badsum);
5625 			break;
5626 		    }
5627 #ifdef INET
5628 		case IPPROTO_ICMP:
5629 		    {
5630 			KMOD_ICMPSTAT_INC(icps_checksum);
5631 			break;
5632 		    }
5633 #endif
5634 #ifdef INET6
5635 		case IPPROTO_ICMPV6:
5636 		    {
5637 			KMOD_ICMP6STAT_INC(icp6s_checksum);
5638 			break;
5639 		    }
5640 #endif /* INET6 */
5641 		}
5642 		return (1);
5643 	} else {
5644 		if (p == IPPROTO_TCP || p == IPPROTO_UDP) {
5645 			m->m_pkthdr.csum_flags |=
5646 			    (CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
5647 			m->m_pkthdr.csum_data = 0xffff;
5648 		}
5649 	}
5650 	return (0);
5651 }
5652 
5653 
5654 #ifdef INET
5655 int
pf_test(int dir,struct ifnet * ifp,struct mbuf ** m0,struct inpcb * inp)5656 pf_test(int dir, struct ifnet *ifp, struct mbuf **m0, struct inpcb *inp)
5657 {
5658 	struct pfi_kif		*kif;
5659 	u_short			 action, reason = 0, log = 0;
5660 	struct mbuf		*m = *m0;
5661 	struct ip		*h = NULL;
5662 	struct m_tag		*ipfwtag;
5663 	struct pf_rule		*a = NULL, *r = &V_pf_default_rule, *tr, *nr;
5664 	struct pf_state		*s = NULL;
5665 	struct pf_ruleset	*ruleset = NULL;
5666 	struct pf_pdesc		 pd;
5667 	int			 off, dirndx, pqid = 0;
5668 
5669 	M_ASSERTPKTHDR(m);
5670 
5671 	if (!V_pf_status.running)
5672 		return (PF_PASS);
5673 
5674 	memset(&pd, 0, sizeof(pd));
5675 
5676 	kif = (struct pfi_kif *)ifp->if_pf_kif;
5677 
5678 	if (kif == NULL) {
5679 		DPFPRINTF(PF_DEBUG_URGENT,
5680 		    ("pf_test: kif == NULL, if_xname %s\n", ifp->if_xname));
5681 		return (PF_DROP);
5682 	}
5683 	if (kif->pfik_flags & PFI_IFLAG_SKIP)
5684 		return (PF_PASS);
5685 
5686 	if (m->m_flags & M_SKIP_FIREWALL)
5687 		return (PF_PASS);
5688 
5689 	pd.pf_mtag = pf_find_mtag(m);
5690 
5691 	PF_RULES_RLOCK();
5692 
5693 	if (ip_divert_ptr != NULL &&
5694 	    ((ipfwtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL)) != NULL)) {
5695 		struct ipfw_rule_ref *rr = (struct ipfw_rule_ref *)(ipfwtag+1);
5696 		if (rr->info & IPFW_IS_DIVERT && rr->rulenum == 0) {
5697 			if (pd.pf_mtag == NULL &&
5698 			    ((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
5699 				action = PF_DROP;
5700 				goto done;
5701 			}
5702 			pd.pf_mtag->flags |= PF_PACKET_LOOPED;
5703 			m_tag_delete(m, ipfwtag);
5704 		}
5705 		if (pd.pf_mtag && pd.pf_mtag->flags & PF_FASTFWD_OURS_PRESENT) {
5706 			m->m_flags |= M_FASTFWD_OURS;
5707 			pd.pf_mtag->flags &= ~PF_FASTFWD_OURS_PRESENT;
5708 		}
5709 	} else if (pf_normalize_ip(m0, dir, kif, &reason, &pd) != PF_PASS) {
5710 		/* We do IP header normalization and packet reassembly here */
5711 		action = PF_DROP;
5712 		goto done;
5713 	}
5714 	m = *m0;	/* pf_normalize messes with m0 */
5715 	h = mtod(m, struct ip *);
5716 
5717 	off = h->ip_hl << 2;
5718 	if (off < (int)sizeof(struct ip)) {
5719 		action = PF_DROP;
5720 		REASON_SET(&reason, PFRES_SHORT);
5721 		log = 1;
5722 		goto done;
5723 	}
5724 
5725 	pd.src = (struct pf_addr *)&h->ip_src;
5726 	pd.dst = (struct pf_addr *)&h->ip_dst;
5727 	pd.sport = pd.dport = NULL;
5728 	pd.ip_sum = &h->ip_sum;
5729 	pd.proto_sum = NULL;
5730 	pd.proto = h->ip_p;
5731 	pd.dir = dir;
5732 	pd.sidx = (dir == PF_IN) ? 0 : 1;
5733 	pd.didx = (dir == PF_IN) ? 1 : 0;
5734 	pd.af = AF_INET;
5735 	pd.tos = h->ip_tos;
5736 	pd.tot_len = ntohs(h->ip_len);
5737 
5738 	/* handle fragments that didn't get reassembled by normalization */
5739 	if (h->ip_off & htons(IP_MF | IP_OFFMASK)) {
5740 		action = pf_test_fragment(&r, dir, kif, m, h,
5741 		    &pd, &a, &ruleset);
5742 		goto done;
5743 	}
5744 
5745 	switch (h->ip_p) {
5746 
5747 	case IPPROTO_TCP: {
5748 		struct tcphdr	th;
5749 
5750 		pd.hdr.tcp = &th;
5751 		if (!pf_pull_hdr(m, off, &th, sizeof(th),
5752 		    &action, &reason, AF_INET)) {
5753 			log = action != PF_PASS;
5754 			goto done;
5755 		}
5756 		pd.p_len = pd.tot_len - off - (th.th_off << 2);
5757 		if ((th.th_flags & TH_ACK) && pd.p_len == 0)
5758 			pqid = 1;
5759 		action = pf_normalize_tcp(dir, kif, m, 0, off, h, &pd);
5760 		if (action == PF_DROP)
5761 			goto done;
5762 		action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd,
5763 		    &reason);
5764 		if (action == PF_PASS) {
5765 			if (pfsync_update_state_ptr != NULL)
5766 				pfsync_update_state_ptr(s);
5767 			r = s->rule.ptr;
5768 			a = s->anchor.ptr;
5769 			log = s->log;
5770 		} else if (s == NULL)
5771 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
5772 			    &a, &ruleset, inp);
5773 		break;
5774 	}
5775 
5776 	case IPPROTO_UDP: {
5777 		struct udphdr	uh;
5778 
5779 		pd.hdr.udp = &uh;
5780 		if (!pf_pull_hdr(m, off, &uh, sizeof(uh),
5781 		    &action, &reason, AF_INET)) {
5782 			log = action != PF_PASS;
5783 			goto done;
5784 		}
5785 		if (uh.uh_dport == 0 ||
5786 		    ntohs(uh.uh_ulen) > m->m_pkthdr.len - off ||
5787 		    ntohs(uh.uh_ulen) < sizeof(struct udphdr)) {
5788 			action = PF_DROP;
5789 			REASON_SET(&reason, PFRES_SHORT);
5790 			goto done;
5791 		}
5792 		action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd);
5793 		if (action == PF_PASS) {
5794 			if (pfsync_update_state_ptr != NULL)
5795 				pfsync_update_state_ptr(s);
5796 			r = s->rule.ptr;
5797 			a = s->anchor.ptr;
5798 			log = s->log;
5799 		} else if (s == NULL)
5800 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
5801 			    &a, &ruleset, inp);
5802 		break;
5803 	}
5804 
5805 	case IPPROTO_ICMP: {
5806 		struct icmp	ih;
5807 
5808 		pd.hdr.icmp = &ih;
5809 		if (!pf_pull_hdr(m, off, &ih, ICMP_MINLEN,
5810 		    &action, &reason, AF_INET)) {
5811 			log = action != PF_PASS;
5812 			goto done;
5813 		}
5814 		action = pf_test_state_icmp(&s, dir, kif, m, off, h, &pd,
5815 		    &reason);
5816 		if (action == PF_PASS) {
5817 			if (pfsync_update_state_ptr != NULL)
5818 				pfsync_update_state_ptr(s);
5819 			r = s->rule.ptr;
5820 			a = s->anchor.ptr;
5821 			log = s->log;
5822 		} else if (s == NULL)
5823 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
5824 			    &a, &ruleset, inp);
5825 		break;
5826 	}
5827 
5828 #ifdef INET6
5829 	case IPPROTO_ICMPV6: {
5830 		action = PF_DROP;
5831 		DPFPRINTF(PF_DEBUG_MISC,
5832 		    ("pf: dropping IPv4 packet with ICMPv6 payload\n"));
5833 		goto done;
5834 	}
5835 #endif
5836 
5837 	default:
5838 		action = pf_test_state_other(&s, dir, kif, m, &pd);
5839 		if (action == PF_PASS) {
5840 			if (pfsync_update_state_ptr != NULL)
5841 				pfsync_update_state_ptr(s);
5842 			r = s->rule.ptr;
5843 			a = s->anchor.ptr;
5844 			log = s->log;
5845 		} else if (s == NULL)
5846 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
5847 			    &a, &ruleset, inp);
5848 		break;
5849 	}
5850 
5851 done:
5852 	PF_RULES_RUNLOCK();
5853 	if (action == PF_PASS && h->ip_hl > 5 &&
5854 	    !((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) {
5855 		action = PF_DROP;
5856 		REASON_SET(&reason, PFRES_IPOPTIONS);
5857 		log = 1;
5858 		DPFPRINTF(PF_DEBUG_MISC,
5859 		    ("pf: dropping packet with ip options\n"));
5860 	}
5861 
5862 	if (s && s->tag > 0 && pf_tag_packet(m, &pd, s->tag)) {
5863 		action = PF_DROP;
5864 		REASON_SET(&reason, PFRES_MEMORY);
5865 	}
5866 	if (r->rtableid >= 0)
5867 		M_SETFIB(m, r->rtableid);
5868 
5869 #ifdef ALTQ
5870 	if (action == PF_PASS && r->qid) {
5871 		if (pd.pf_mtag == NULL &&
5872 		    ((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
5873 			action = PF_DROP;
5874 			REASON_SET(&reason, PFRES_MEMORY);
5875 		}
5876 		if (pqid || (pd.tos & IPTOS_LOWDELAY))
5877 			pd.pf_mtag->qid = r->pqid;
5878 		else
5879 			pd.pf_mtag->qid = r->qid;
5880 		/* add hints for ecn */
5881 		pd.pf_mtag->hdr = h;
5882 
5883 	}
5884 #endif /* ALTQ */
5885 
5886 	/*
5887 	 * connections redirected to loopback should not match sockets
5888 	 * bound specifically to loopback due to security implications,
5889 	 * see tcp_input() and in_pcblookup_listen().
5890 	 */
5891 	if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP ||
5892 	    pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL &&
5893 	    (s->nat_rule.ptr->action == PF_RDR ||
5894 	    s->nat_rule.ptr->action == PF_BINAT) &&
5895 	    (ntohl(pd.dst->v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
5896 		m->m_flags |= M_SKIP_FIREWALL;
5897 
5898 	if (action == PF_PASS && r->divert.port && ip_divert_ptr != NULL &&
5899 	    !PACKET_LOOPED(&pd)) {
5900 
5901 		ipfwtag = m_tag_alloc(MTAG_IPFW_RULE, 0,
5902 		    sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO);
5903 		if (ipfwtag != NULL) {
5904 			((struct ipfw_rule_ref *)(ipfwtag+1))->info =
5905 			    ntohs(r->divert.port);
5906 			((struct ipfw_rule_ref *)(ipfwtag+1))->rulenum = dir;
5907 
5908 			if (s)
5909 				PF_STATE_UNLOCK(s);
5910 
5911 			m_tag_prepend(m, ipfwtag);
5912 			if (m->m_flags & M_FASTFWD_OURS) {
5913 				if (pd.pf_mtag == NULL &&
5914 				    ((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
5915 					action = PF_DROP;
5916 					REASON_SET(&reason, PFRES_MEMORY);
5917 					log = 1;
5918 					DPFPRINTF(PF_DEBUG_MISC,
5919 					    ("pf: failed to allocate tag\n"));
5920 				}
5921 				pd.pf_mtag->flags |= PF_FASTFWD_OURS_PRESENT;
5922 				m->m_flags &= ~M_FASTFWD_OURS;
5923 			}
5924 			ip_divert_ptr(*m0, dir ==  PF_IN ? DIR_IN : DIR_OUT);
5925 			*m0 = NULL;
5926 
5927 			return (action);
5928 		} else {
5929 			/* XXX: ipfw has the same behaviour! */
5930 			action = PF_DROP;
5931 			REASON_SET(&reason, PFRES_MEMORY);
5932 			log = 1;
5933 			DPFPRINTF(PF_DEBUG_MISC,
5934 			    ("pf: failed to allocate divert tag\n"));
5935 		}
5936 	}
5937 
5938 	if (log) {
5939 		struct pf_rule *lr;
5940 
5941 		if (s != NULL && s->nat_rule.ptr != NULL &&
5942 		    s->nat_rule.ptr->log & PF_LOG_ALL)
5943 			lr = s->nat_rule.ptr;
5944 		else
5945 			lr = r;
5946 		PFLOG_PACKET(kif, m, AF_INET, dir, reason, lr, a, ruleset, &pd,
5947 		    (s == NULL));
5948 	}
5949 
5950 	kif->pfik_bytes[0][dir == PF_OUT][action != PF_PASS] += pd.tot_len;
5951 	kif->pfik_packets[0][dir == PF_OUT][action != PF_PASS]++;
5952 
5953 	if (action == PF_PASS || r->action == PF_DROP) {
5954 		dirndx = (dir == PF_OUT);
5955 		r->packets[dirndx]++;
5956 		r->bytes[dirndx] += pd.tot_len;
5957 		if (a != NULL) {
5958 			a->packets[dirndx]++;
5959 			a->bytes[dirndx] += pd.tot_len;
5960 		}
5961 		if (s != NULL) {
5962 			if (s->nat_rule.ptr != NULL) {
5963 				s->nat_rule.ptr->packets[dirndx]++;
5964 				s->nat_rule.ptr->bytes[dirndx] += pd.tot_len;
5965 			}
5966 			if (s->src_node != NULL) {
5967 				s->src_node->packets[dirndx]++;
5968 				s->src_node->bytes[dirndx] += pd.tot_len;
5969 			}
5970 			if (s->nat_src_node != NULL) {
5971 				s->nat_src_node->packets[dirndx]++;
5972 				s->nat_src_node->bytes[dirndx] += pd.tot_len;
5973 			}
5974 			dirndx = (dir == s->direction) ? 0 : 1;
5975 			s->packets[dirndx]++;
5976 			s->bytes[dirndx] += pd.tot_len;
5977 		}
5978 		tr = r;
5979 		nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule;
5980 		if (nr != NULL && r == &V_pf_default_rule)
5981 			tr = nr;
5982 		if (tr->src.addr.type == PF_ADDR_TABLE)
5983 			pfr_update_stats(tr->src.addr.p.tbl,
5984 			    (s == NULL) ? pd.src :
5985 			    &s->key[(s->direction == PF_IN)]->
5986 				addr[(s->direction == PF_OUT)],
5987 			    pd.af, pd.tot_len, dir == PF_OUT,
5988 			    r->action == PF_PASS, tr->src.neg);
5989 		if (tr->dst.addr.type == PF_ADDR_TABLE)
5990 			pfr_update_stats(tr->dst.addr.p.tbl,
5991 			    (s == NULL) ? pd.dst :
5992 			    &s->key[(s->direction == PF_IN)]->
5993 				addr[(s->direction == PF_IN)],
5994 			    pd.af, pd.tot_len, dir == PF_OUT,
5995 			    r->action == PF_PASS, tr->dst.neg);
5996 	}
5997 
5998 	switch (action) {
5999 	case PF_SYNPROXY_DROP:
6000 		m_freem(*m0);
6001 	case PF_DEFER:
6002 		*m0 = NULL;
6003 		action = PF_PASS;
6004 		break;
6005 	case PF_DROP:
6006 		m_freem(*m0);
6007 		*m0 = NULL;
6008 		break;
6009 	default:
6010 		/* pf_route() returns unlocked. */
6011 		if (r->rt) {
6012 			pf_route(m0, r, dir, kif->pfik_ifp, s, &pd);
6013 			return (action);
6014 		}
6015 		break;
6016 	}
6017 	if (s)
6018 		PF_STATE_UNLOCK(s);
6019 
6020 	return (action);
6021 }
6022 #endif /* INET */
6023 
6024 #ifdef INET6
6025 int
pf_test6(int dir,struct ifnet * ifp,struct mbuf ** m0,struct inpcb * inp)6026 pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0, struct inpcb *inp)
6027 {
6028 	struct pfi_kif		*kif;
6029 	u_short			 action, reason = 0, log = 0;
6030 	struct mbuf		*m = *m0, *n = NULL;
6031 	struct ip6_hdr		*h = NULL;
6032 	struct pf_rule		*a = NULL, *r = &V_pf_default_rule, *tr, *nr;
6033 	struct pf_state		*s = NULL;
6034 	struct pf_ruleset	*ruleset = NULL;
6035 	struct pf_pdesc		 pd;
6036 	int			 off, terminal = 0, dirndx, rh_cnt = 0;
6037 
6038 	M_ASSERTPKTHDR(m);
6039 
6040 	if (!V_pf_status.running)
6041 		return (PF_PASS);
6042 
6043 	memset(&pd, 0, sizeof(pd));
6044 	pd.pf_mtag = pf_find_mtag(m);
6045 
6046 	if (pd.pf_mtag && pd.pf_mtag->flags & PF_TAG_GENERATED)
6047 		return (PF_PASS);
6048 
6049 	kif = (struct pfi_kif *)ifp->if_pf_kif;
6050 	if (kif == NULL) {
6051 		DPFPRINTF(PF_DEBUG_URGENT,
6052 		    ("pf_test6: kif == NULL, if_xname %s\n", ifp->if_xname));
6053 		return (PF_DROP);
6054 	}
6055 	if (kif->pfik_flags & PFI_IFLAG_SKIP)
6056 		return (PF_PASS);
6057 
6058 	if (m->m_flags & M_SKIP_FIREWALL)
6059 		return (PF_PASS);
6060 
6061 	PF_RULES_RLOCK();
6062 
6063 	/* We do IP header normalization and packet reassembly here */
6064 	if (pf_normalize_ip6(m0, dir, kif, &reason, &pd) != PF_PASS) {
6065 		action = PF_DROP;
6066 		goto done;
6067 	}
6068 	m = *m0;	/* pf_normalize messes with m0 */
6069 	h = mtod(m, struct ip6_hdr *);
6070 
6071 #if 1
6072 	/*
6073 	 * we do not support jumbogram yet.  if we keep going, zero ip6_plen
6074 	 * will do something bad, so drop the packet for now.
6075 	 */
6076 	if (htons(h->ip6_plen) == 0) {
6077 		action = PF_DROP;
6078 		REASON_SET(&reason, PFRES_NORM);	/*XXX*/
6079 		goto done;
6080 	}
6081 #endif
6082 
6083 	pd.src = (struct pf_addr *)&h->ip6_src;
6084 	pd.dst = (struct pf_addr *)&h->ip6_dst;
6085 	pd.sport = pd.dport = NULL;
6086 	pd.ip_sum = NULL;
6087 	pd.proto_sum = NULL;
6088 	pd.dir = dir;
6089 	pd.sidx = (dir == PF_IN) ? 0 : 1;
6090 	pd.didx = (dir == PF_IN) ? 1 : 0;
6091 	pd.af = AF_INET6;
6092 	pd.tos = 0;
6093 	pd.tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
6094 
6095 	off = ((caddr_t)h - m->m_data) + sizeof(struct ip6_hdr);
6096 	pd.proto = h->ip6_nxt;
6097 	do {
6098 		switch (pd.proto) {
6099 		case IPPROTO_FRAGMENT:
6100 			action = pf_test_fragment(&r, dir, kif, m, h,
6101 			    &pd, &a, &ruleset);
6102 			if (action == PF_DROP)
6103 				REASON_SET(&reason, PFRES_FRAG);
6104 			goto done;
6105 		case IPPROTO_ROUTING: {
6106 			struct ip6_rthdr rthdr;
6107 
6108 			if (rh_cnt++) {
6109 				DPFPRINTF(PF_DEBUG_MISC,
6110 				    ("pf: IPv6 more than one rthdr\n"));
6111 				action = PF_DROP;
6112 				REASON_SET(&reason, PFRES_IPOPTIONS);
6113 				log = 1;
6114 				goto done;
6115 			}
6116 			if (!pf_pull_hdr(m, off, &rthdr, sizeof(rthdr), NULL,
6117 			    &reason, pd.af)) {
6118 				DPFPRINTF(PF_DEBUG_MISC,
6119 				    ("pf: IPv6 short rthdr\n"));
6120 				action = PF_DROP;
6121 				REASON_SET(&reason, PFRES_SHORT);
6122 				log = 1;
6123 				goto done;
6124 			}
6125 			if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) {
6126 				DPFPRINTF(PF_DEBUG_MISC,
6127 				    ("pf: IPv6 rthdr0\n"));
6128 				action = PF_DROP;
6129 				REASON_SET(&reason, PFRES_IPOPTIONS);
6130 				log = 1;
6131 				goto done;
6132 			}
6133 			/* FALLTHROUGH */
6134 		}
6135 		case IPPROTO_AH:
6136 		case IPPROTO_HOPOPTS:
6137 		case IPPROTO_DSTOPTS: {
6138 			/* get next header and header length */
6139 			struct ip6_ext	opt6;
6140 
6141 			if (!pf_pull_hdr(m, off, &opt6, sizeof(opt6),
6142 			    NULL, &reason, pd.af)) {
6143 				DPFPRINTF(PF_DEBUG_MISC,
6144 				    ("pf: IPv6 short opt\n"));
6145 				action = PF_DROP;
6146 				log = 1;
6147 				goto done;
6148 			}
6149 			if (pd.proto == IPPROTO_AH)
6150 				off += (opt6.ip6e_len + 2) * 4;
6151 			else
6152 				off += (opt6.ip6e_len + 1) * 8;
6153 			pd.proto = opt6.ip6e_nxt;
6154 			/* goto the next header */
6155 			break;
6156 		}
6157 		default:
6158 			terminal++;
6159 			break;
6160 		}
6161 	} while (!terminal);
6162 
6163 	/* if there's no routing header, use unmodified mbuf for checksumming */
6164 	if (!n)
6165 		n = m;
6166 
6167 	switch (pd.proto) {
6168 
6169 	case IPPROTO_TCP: {
6170 		struct tcphdr	th;
6171 
6172 		pd.hdr.tcp = &th;
6173 		if (!pf_pull_hdr(m, off, &th, sizeof(th),
6174 		    &action, &reason, AF_INET6)) {
6175 			log = action != PF_PASS;
6176 			goto done;
6177 		}
6178 		pd.p_len = pd.tot_len - off - (th.th_off << 2);
6179 		action = pf_normalize_tcp(dir, kif, m, 0, off, h, &pd);
6180 		if (action == PF_DROP)
6181 			goto done;
6182 		action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd,
6183 		    &reason);
6184 		if (action == PF_PASS) {
6185 			if (pfsync_update_state_ptr != NULL)
6186 				pfsync_update_state_ptr(s);
6187 			r = s->rule.ptr;
6188 			a = s->anchor.ptr;
6189 			log = s->log;
6190 		} else if (s == NULL)
6191 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
6192 			    &a, &ruleset, inp);
6193 		break;
6194 	}
6195 
6196 	case IPPROTO_UDP: {
6197 		struct udphdr	uh;
6198 
6199 		pd.hdr.udp = &uh;
6200 		if (!pf_pull_hdr(m, off, &uh, sizeof(uh),
6201 		    &action, &reason, AF_INET6)) {
6202 			log = action != PF_PASS;
6203 			goto done;
6204 		}
6205 		if (uh.uh_dport == 0 ||
6206 		    ntohs(uh.uh_ulen) > m->m_pkthdr.len - off ||
6207 		    ntohs(uh.uh_ulen) < sizeof(struct udphdr)) {
6208 			action = PF_DROP;
6209 			REASON_SET(&reason, PFRES_SHORT);
6210 			goto done;
6211 		}
6212 		action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd);
6213 		if (action == PF_PASS) {
6214 			if (pfsync_update_state_ptr != NULL)
6215 				pfsync_update_state_ptr(s);
6216 			r = s->rule.ptr;
6217 			a = s->anchor.ptr;
6218 			log = s->log;
6219 		} else if (s == NULL)
6220 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
6221 			    &a, &ruleset, inp);
6222 		break;
6223 	}
6224 
6225 	case IPPROTO_ICMP: {
6226 		action = PF_DROP;
6227 		DPFPRINTF(PF_DEBUG_MISC,
6228 		    ("pf: dropping IPv6 packet with ICMPv4 payload\n"));
6229 		goto done;
6230 	}
6231 
6232 	case IPPROTO_ICMPV6: {
6233 		struct icmp6_hdr	ih;
6234 
6235 		pd.hdr.icmp6 = &ih;
6236 		if (!pf_pull_hdr(m, off, &ih, sizeof(ih),
6237 		    &action, &reason, AF_INET6)) {
6238 			log = action != PF_PASS;
6239 			goto done;
6240 		}
6241 		action = pf_test_state_icmp(&s, dir, kif,
6242 		    m, off, h, &pd, &reason);
6243 		if (action == PF_PASS) {
6244 			if (pfsync_update_state_ptr != NULL)
6245 				pfsync_update_state_ptr(s);
6246 			r = s->rule.ptr;
6247 			a = s->anchor.ptr;
6248 			log = s->log;
6249 		} else if (s == NULL)
6250 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
6251 			    &a, &ruleset, inp);
6252 		break;
6253 	}
6254 
6255 	default:
6256 		action = pf_test_state_other(&s, dir, kif, m, &pd);
6257 		if (action == PF_PASS) {
6258 			if (pfsync_update_state_ptr != NULL)
6259 				pfsync_update_state_ptr(s);
6260 			r = s->rule.ptr;
6261 			a = s->anchor.ptr;
6262 			log = s->log;
6263 		} else if (s == NULL)
6264 			action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
6265 			    &a, &ruleset, inp);
6266 		break;
6267 	}
6268 
6269 done:
6270 	PF_RULES_RUNLOCK();
6271 	if (n != m) {
6272 		m_freem(n);
6273 		n = NULL;
6274 	}
6275 
6276 	/* handle dangerous IPv6 extension headers. */
6277 	if (action == PF_PASS && rh_cnt &&
6278 	    !((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) {
6279 		action = PF_DROP;
6280 		REASON_SET(&reason, PFRES_IPOPTIONS);
6281 		log = 1;
6282 		DPFPRINTF(PF_DEBUG_MISC,
6283 		    ("pf: dropping packet with dangerous v6 headers\n"));
6284 	}
6285 
6286 	if (s && s->tag > 0 && pf_tag_packet(m, &pd, s->tag)) {
6287 		action = PF_DROP;
6288 		REASON_SET(&reason, PFRES_MEMORY);
6289 	}
6290 	if (r->rtableid >= 0)
6291 		M_SETFIB(m, r->rtableid);
6292 
6293 #ifdef ALTQ
6294 	if (action == PF_PASS && r->qid) {
6295 		if (pd.pf_mtag == NULL &&
6296 		    ((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
6297 			action = PF_DROP;
6298 			REASON_SET(&reason, PFRES_MEMORY);
6299 		}
6300 		if (pd.tos & IPTOS_LOWDELAY)
6301 			pd.pf_mtag->qid = r->pqid;
6302 		else
6303 			pd.pf_mtag->qid = r->qid;
6304 		/* add hints for ecn */
6305 		pd.pf_mtag->hdr = h;
6306 	}
6307 #endif /* ALTQ */
6308 
6309 	if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP ||
6310 	    pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL &&
6311 	    (s->nat_rule.ptr->action == PF_RDR ||
6312 	    s->nat_rule.ptr->action == PF_BINAT) &&
6313 	    IN6_IS_ADDR_LOOPBACK(&pd.dst->v6))
6314 		m->m_flags |= M_SKIP_FIREWALL;
6315 
6316 	/* XXX: Anybody working on it?! */
6317 	if (r->divert.port)
6318 		printf("pf: divert(9) is not supported for IPv6\n");
6319 
6320 	if (log) {
6321 		struct pf_rule *lr;
6322 
6323 		if (s != NULL && s->nat_rule.ptr != NULL &&
6324 		    s->nat_rule.ptr->log & PF_LOG_ALL)
6325 			lr = s->nat_rule.ptr;
6326 		else
6327 			lr = r;
6328 		PFLOG_PACKET(kif, m, AF_INET6, dir, reason, lr, a, ruleset,
6329 		    &pd, (s == NULL));
6330 	}
6331 
6332 	kif->pfik_bytes[1][dir == PF_OUT][action != PF_PASS] += pd.tot_len;
6333 	kif->pfik_packets[1][dir == PF_OUT][action != PF_PASS]++;
6334 
6335 	if (action == PF_PASS || r->action == PF_DROP) {
6336 		dirndx = (dir == PF_OUT);
6337 		r->packets[dirndx]++;
6338 		r->bytes[dirndx] += pd.tot_len;
6339 		if (a != NULL) {
6340 			a->packets[dirndx]++;
6341 			a->bytes[dirndx] += pd.tot_len;
6342 		}
6343 		if (s != NULL) {
6344 			if (s->nat_rule.ptr != NULL) {
6345 				s->nat_rule.ptr->packets[dirndx]++;
6346 				s->nat_rule.ptr->bytes[dirndx] += pd.tot_len;
6347 			}
6348 			if (s->src_node != NULL) {
6349 				s->src_node->packets[dirndx]++;
6350 				s->src_node->bytes[dirndx] += pd.tot_len;
6351 			}
6352 			if (s->nat_src_node != NULL) {
6353 				s->nat_src_node->packets[dirndx]++;
6354 				s->nat_src_node->bytes[dirndx] += pd.tot_len;
6355 			}
6356 			dirndx = (dir == s->direction) ? 0 : 1;
6357 			s->packets[dirndx]++;
6358 			s->bytes[dirndx] += pd.tot_len;
6359 		}
6360 		tr = r;
6361 		nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule;
6362 		if (nr != NULL && r == &V_pf_default_rule)
6363 			tr = nr;
6364 		if (tr->src.addr.type == PF_ADDR_TABLE)
6365 			pfr_update_stats(tr->src.addr.p.tbl,
6366 			    (s == NULL) ? pd.src :
6367 			    &s->key[(s->direction == PF_IN)]->addr[0],
6368 			    pd.af, pd.tot_len, dir == PF_OUT,
6369 			    r->action == PF_PASS, tr->src.neg);
6370 		if (tr->dst.addr.type == PF_ADDR_TABLE)
6371 			pfr_update_stats(tr->dst.addr.p.tbl,
6372 			    (s == NULL) ? pd.dst :
6373 			    &s->key[(s->direction == PF_IN)]->addr[1],
6374 			    pd.af, pd.tot_len, dir == PF_OUT,
6375 			    r->action == PF_PASS, tr->dst.neg);
6376 	}
6377 
6378 	switch (action) {
6379 	case PF_SYNPROXY_DROP:
6380 		m_freem(*m0);
6381 	case PF_DEFER:
6382 		*m0 = NULL;
6383 		action = PF_PASS;
6384 		break;
6385 	case PF_DROP:
6386 		m_freem(*m0);
6387 		*m0 = NULL;
6388 		break;
6389 	default:
6390 		/* pf_route6() returns unlocked. */
6391 		if (r->rt) {
6392 			pf_route6(m0, r, dir, kif->pfik_ifp, s, &pd);
6393 			return (action);
6394 		}
6395 		break;
6396 	}
6397 
6398 	if (s)
6399 		PF_STATE_UNLOCK(s);
6400 
6401 	return (action);
6402 }
6403 #endif /* INET6 */
6404