1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002 Michael Shalayeff.
5 * Copyright (c) 2003 Ryan McBride.
6 * Copyright (c) 2011 Gleb Smirnoff <glebius@FreeBSD.org>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28 * THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: stable/12/sys/netinet/ip_carp.c 373178 2023-09-01 09:08:15Z ae $");
33
34 #include "opt_bpf.h"
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/bus.h>
41 #include <sys/jail.h>
42 #include <sys/kernel.h>
43 #include <sys/limits.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/module.h>
47 #include <sys/priv.h>
48 #include <sys/proc.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/sockio.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/taskqueue.h>
55 #include <sys/counter.h>
56
57 #include <net/ethernet.h>
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <net/if_dl.h>
61 #include <net/if_llatbl.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <net/vnet.h>
65
66 #if defined(INET) || defined(INET6)
67 #include <netinet/in.h>
68 #include <netinet/in_var.h>
69 #include <netinet/ip_carp.h>
70 #include <netinet/ip.h>
71 #include <machine/in_cksum.h>
72 #endif
73 #ifdef INET
74 #include <netinet/ip_var.h>
75 #include <netinet/if_ether.h>
76 #endif
77
78 #ifdef INET6
79 #include <netinet/icmp6.h>
80 #include <netinet/ip6.h>
81 #include <netinet6/in6_var.h>
82 #include <netinet6/ip6_var.h>
83 #include <netinet6/scope6_var.h>
84 #include <netinet6/nd6.h>
85 #endif
86
87 #include <crypto/sha1.h>
88
89 static MALLOC_DEFINE(M_CARP, "CARP", "CARP addresses");
90
91 struct carp_softc {
92 struct ifnet *sc_carpdev; /* Pointer to parent ifnet. */
93 struct ifaddr **sc_ifas; /* Our ifaddrs. */
94 struct sockaddr_dl sc_addr; /* Our link level address. */
95 struct callout sc_ad_tmo; /* Advertising timeout. */
96 #ifdef INET
97 struct callout sc_md_tmo; /* Master down timeout. */
98 #endif
99 #ifdef INET6
100 struct callout sc_md6_tmo; /* XXX: Master down timeout. */
101 #endif
102 struct mtx sc_mtx;
103
104 int sc_vhid;
105 int sc_advskew;
106 int sc_advbase;
107
108 int sc_naddrs;
109 int sc_naddrs6;
110 int sc_ifasiz;
111 enum { INIT = 0, BACKUP, MASTER } sc_state;
112 int sc_suppress;
113 int sc_sendad_errors;
114 #define CARP_SENDAD_MAX_ERRORS 3
115 int sc_sendad_success;
116 #define CARP_SENDAD_MIN_SUCCESS 3
117
118 int sc_init_counter;
119 uint64_t sc_counter;
120
121 /* authentication */
122 #define CARP_HMAC_PAD 64
123 unsigned char sc_key[CARP_KEY_LEN];
124 unsigned char sc_pad[CARP_HMAC_PAD];
125 SHA1_CTX sc_sha1;
126
127 TAILQ_ENTRY(carp_softc) sc_list; /* On the carp_if list. */
128 LIST_ENTRY(carp_softc) sc_next; /* On the global list. */
129 };
130
131 struct carp_if {
132 #ifdef INET
133 int cif_naddrs;
134 #endif
135 #ifdef INET6
136 int cif_naddrs6;
137 #endif
138 TAILQ_HEAD(, carp_softc) cif_vrs;
139 #ifdef INET
140 struct ip_moptions cif_imo;
141 #endif
142 #ifdef INET6
143 struct ip6_moptions cif_im6o;
144 #endif
145 struct ifnet *cif_ifp;
146 struct mtx cif_mtx;
147 uint32_t cif_flags;
148 #define CIF_PROMISC 0x00000001
149 };
150
151 #define CARP_INET 0
152 #define CARP_INET6 1
153 static int proto_reg[] = {-1, -1};
154
155 /*
156 * Brief design of carp(4).
157 *
158 * Any carp-capable ifnet may have a list of carp softcs hanging off
159 * its ifp->if_carp pointer. Each softc represents one unique virtual
160 * host id, or vhid. The softc has a back pointer to the ifnet. All
161 * softcs are joined in a global list, which has quite limited use.
162 *
163 * Any interface address that takes part in CARP negotiation has a
164 * pointer to the softc of its vhid, ifa->ifa_carp. That could be either
165 * AF_INET or AF_INET6 address.
166 *
167 * Although, one can get the softc's backpointer to ifnet and traverse
168 * through its ifp->if_addrhead queue to find all interface addresses
169 * involved in CARP, we keep a growable array of ifaddr pointers. This
170 * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that
171 * do calls into the network stack, thus avoiding LORs.
172 *
173 * Locking:
174 *
175 * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(),
176 * callout-driven events and ioctl()s.
177 *
178 * To traverse the list of softcs on an ifnet we use CIF_LOCK() or carp_sx.
179 * To traverse the global list we use the mutex carp_mtx.
180 *
181 * Known issues with locking:
182 *
183 * - Sending ad, we put the pointer to the softc in an mtag, and no reference
184 * counting is done on the softc.
185 * - On module unload we may race (?) with packet processing thread
186 * dereferencing our function pointers.
187 */
188
189 /* Accept incoming CARP packets. */
190 VNET_DEFINE_STATIC(int, carp_allow) = 1;
191 #define V_carp_allow VNET(carp_allow)
192
193 /* Set DSCP in outgoing CARP packets. */
194 VNET_DEFINE_STATIC(int, carp_dscp) = 56;
195 #define V_carp_dscp VNET(carp_dscp)
196
197 /* Preempt slower nodes. */
198 VNET_DEFINE_STATIC(int, carp_preempt) = 0;
199 #define V_carp_preempt VNET(carp_preempt)
200
201 /* Log level. */
202 VNET_DEFINE_STATIC(int, carp_log) = 1;
203 #define V_carp_log VNET(carp_log)
204
205 /* Global advskew demotion. */
206 VNET_DEFINE_STATIC(int, carp_demotion) = 0;
207 #define V_carp_demotion VNET(carp_demotion)
208
209 /* Send error demotion factor. */
210 VNET_DEFINE_STATIC(int, carp_senderr_adj) = CARP_MAXSKEW;
211 #define V_carp_senderr_adj VNET(carp_senderr_adj)
212
213 /* Iface down demotion factor. */
214 VNET_DEFINE_STATIC(int, carp_ifdown_adj) = CARP_MAXSKEW;
215 #define V_carp_ifdown_adj VNET(carp_ifdown_adj)
216
217 static int carp_allow_sysctl(SYSCTL_HANDLER_ARGS);
218 static int carp_dscp_sysctl(SYSCTL_HANDLER_ARGS);
219 static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS);
220
221 SYSCTL_NODE(_net_inet, IPPROTO_CARP, carp, CTLFLAG_RW, 0, "CARP");
222 SYSCTL_PROC(_net_inet_carp, OID_AUTO, allow,
223 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, 0, 0, carp_allow_sysctl, "I",
224 "Accept incoming CARP packets");
225 SYSCTL_PROC(_net_inet_carp, OID_AUTO, dscp,
226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, 0, 0, carp_dscp_sysctl, "I",
227 "DSCP value for carp packets");
228 SYSCTL_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_VNET | CTLFLAG_RW,
229 &VNET_NAME(carp_preempt), 0, "High-priority backup preemption mode");
230 SYSCTL_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_VNET | CTLFLAG_RW,
231 &VNET_NAME(carp_log), 0, "CARP log level");
232 SYSCTL_PROC(_net_inet_carp, OID_AUTO, demotion,
233 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
234 0, 0, carp_demote_adj_sysctl, "I",
235 "Adjust demotion factor (skew of advskew)");
236 SYSCTL_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor,
237 CTLFLAG_VNET | CTLFLAG_RW,
238 &VNET_NAME(carp_senderr_adj), 0, "Send error demotion factor adjustment");
239 SYSCTL_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor,
240 CTLFLAG_VNET | CTLFLAG_RW,
241 &VNET_NAME(carp_ifdown_adj), 0,
242 "Interface down demotion factor adjustment");
243
244 VNET_PCPUSTAT_DEFINE(struct carpstats, carpstats);
245 VNET_PCPUSTAT_SYSINIT(carpstats);
246 VNET_PCPUSTAT_SYSUNINIT(carpstats);
247
248 #define CARPSTATS_ADD(name, val) \
249 counter_u64_add(VNET(carpstats)[offsetof(struct carpstats, name) / \
250 sizeof(uint64_t)], (val))
251 #define CARPSTATS_INC(name) CARPSTATS_ADD(name, 1)
252
253 SYSCTL_VNET_PCPUSTAT(_net_inet_carp, OID_AUTO, stats, struct carpstats,
254 carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)");
255
256 #define CARP_LOCK_INIT(sc) mtx_init(&(sc)->sc_mtx, "carp_softc", \
257 NULL, MTX_DEF)
258 #define CARP_LOCK_DESTROY(sc) mtx_destroy(&(sc)->sc_mtx)
259 #define CARP_LOCK_ASSERT(sc) mtx_assert(&(sc)->sc_mtx, MA_OWNED)
260 #define CARP_LOCK(sc) mtx_lock(&(sc)->sc_mtx)
261 #define CARP_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx)
262 #define CIF_LOCK_INIT(cif) mtx_init(&(cif)->cif_mtx, "carp_if", \
263 NULL, MTX_DEF)
264 #define CIF_LOCK_DESTROY(cif) mtx_destroy(&(cif)->cif_mtx)
265 #define CIF_LOCK_ASSERT(cif) mtx_assert(&(cif)->cif_mtx, MA_OWNED)
266 #define CIF_LOCK(cif) mtx_lock(&(cif)->cif_mtx)
267 #define CIF_UNLOCK(cif) mtx_unlock(&(cif)->cif_mtx)
268 #define CIF_FREE(cif) do { \
269 CIF_LOCK(cif); \
270 if (TAILQ_EMPTY(&(cif)->cif_vrs)) \
271 carp_free_if(cif); \
272 else \
273 CIF_UNLOCK(cif); \
274 } while (0)
275
276 #define CARP_LOG(...) do { \
277 if (V_carp_log > 0) \
278 log(LOG_INFO, "carp: " __VA_ARGS__); \
279 } while (0)
280
281 #define CARP_DEBUG(...) do { \
282 if (V_carp_log > 1) \
283 log(LOG_DEBUG, __VA_ARGS__); \
284 } while (0)
285
286 #define IFNET_FOREACH_IFA(ifp, ifa) \
287 CK_STAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link) \
288 if ((ifa)->ifa_carp != NULL)
289
290 #define CARP_FOREACH_IFA(sc, ifa) \
291 CARP_LOCK_ASSERT(sc); \
292 for (int _i = 0; \
293 _i < (sc)->sc_naddrs + (sc)->sc_naddrs6 && \
294 ((ifa) = sc->sc_ifas[_i]) != NULL; \
295 ++_i)
296
297 #define IFNET_FOREACH_CARP(ifp, sc) \
298 KASSERT(mtx_owned(&ifp->if_carp->cif_mtx) || \
299 sx_xlocked(&carp_sx), ("cif_vrs not locked")); \
300 TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list)
301
302 #define DEMOTE_ADVSKEW(sc) \
303 (((sc)->sc_advskew + V_carp_demotion > CARP_MAXSKEW) ? \
304 CARP_MAXSKEW : \
305 (((sc)->sc_advskew + V_carp_demotion < 0) ? \
306 0 : ((sc)->sc_advskew + V_carp_demotion)))
307
308 static void carp_input_c(struct mbuf *, struct carp_header *, sa_family_t);
309 static struct carp_softc
310 *carp_alloc(struct ifnet *);
311 static void carp_destroy(struct carp_softc *);
312 static struct carp_if
313 *carp_alloc_if(struct ifnet *);
314 static void carp_free_if(struct carp_if *);
315 static void carp_set_state(struct carp_softc *, int, const char* reason);
316 static void carp_sc_state(struct carp_softc *);
317 static void carp_setrun(struct carp_softc *, sa_family_t);
318 static void carp_master_down(void *);
319 static void carp_master_down_locked(struct carp_softc *,
320 const char* reason);
321 static void carp_send_ad(void *);
322 static void carp_send_ad_locked(struct carp_softc *);
323 static void carp_addroute(struct carp_softc *);
324 static void carp_ifa_addroute(struct ifaddr *);
325 static void carp_delroute(struct carp_softc *);
326 static void carp_ifa_delroute(struct ifaddr *);
327 static void carp_send_ad_all(void *, int);
328 static void carp_demote_adj(int, char *);
329
330 static LIST_HEAD(, carp_softc) carp_list;
331 static struct mtx carp_mtx;
332 static struct sx carp_sx;
333 static struct task carp_sendall_task =
334 TASK_INITIALIZER(0, carp_send_ad_all, NULL);
335
336 static void
carp_hmac_prepare(struct carp_softc * sc)337 carp_hmac_prepare(struct carp_softc *sc)
338 {
339 uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT;
340 uint8_t vhid = sc->sc_vhid & 0xff;
341 struct ifaddr *ifa;
342 int i, found;
343 #ifdef INET
344 struct in_addr last, cur, in;
345 #endif
346 #ifdef INET6
347 struct in6_addr last6, cur6, in6;
348 #endif
349
350 CARP_LOCK_ASSERT(sc);
351
352 /* Compute ipad from key. */
353 bzero(sc->sc_pad, sizeof(sc->sc_pad));
354 bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key));
355 for (i = 0; i < sizeof(sc->sc_pad); i++)
356 sc->sc_pad[i] ^= 0x36;
357
358 /* Precompute first part of inner hash. */
359 SHA1Init(&sc->sc_sha1);
360 SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad));
361 SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version));
362 SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type));
363 SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid));
364 #ifdef INET
365 cur.s_addr = 0;
366 do {
367 found = 0;
368 last = cur;
369 cur.s_addr = 0xffffffff;
370 CARP_FOREACH_IFA(sc, ifa) {
371 in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr;
372 if (ifa->ifa_addr->sa_family == AF_INET &&
373 ntohl(in.s_addr) > ntohl(last.s_addr) &&
374 ntohl(in.s_addr) < ntohl(cur.s_addr)) {
375 cur.s_addr = in.s_addr;
376 found++;
377 }
378 }
379 if (found)
380 SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur));
381 } while (found);
382 #endif /* INET */
383 #ifdef INET6
384 memset(&cur6, 0, sizeof(cur6));
385 do {
386 found = 0;
387 last6 = cur6;
388 memset(&cur6, 0xff, sizeof(cur6));
389 CARP_FOREACH_IFA(sc, ifa) {
390 in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
391 if (IN6_IS_SCOPE_EMBED(&in6))
392 in6.s6_addr16[1] = 0;
393 if (ifa->ifa_addr->sa_family == AF_INET6 &&
394 memcmp(&in6, &last6, sizeof(in6)) > 0 &&
395 memcmp(&in6, &cur6, sizeof(in6)) < 0) {
396 cur6 = in6;
397 found++;
398 }
399 }
400 if (found)
401 SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6));
402 } while (found);
403 #endif /* INET6 */
404
405 /* convert ipad to opad */
406 for (i = 0; i < sizeof(sc->sc_pad); i++)
407 sc->sc_pad[i] ^= 0x36 ^ 0x5c;
408 }
409
410 static void
carp_hmac_generate(struct carp_softc * sc,uint32_t counter[2],unsigned char md[20])411 carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2],
412 unsigned char md[20])
413 {
414 SHA1_CTX sha1ctx;
415
416 CARP_LOCK_ASSERT(sc);
417
418 /* fetch first half of inner hash */
419 bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx));
420
421 SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter));
422 SHA1Final(md, &sha1ctx);
423
424 /* outer hash */
425 SHA1Init(&sha1ctx);
426 SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad));
427 SHA1Update(&sha1ctx, md, 20);
428 SHA1Final(md, &sha1ctx);
429 }
430
431 static int
carp_hmac_verify(struct carp_softc * sc,uint32_t counter[2],unsigned char md[20])432 carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2],
433 unsigned char md[20])
434 {
435 unsigned char md2[20];
436
437 CARP_LOCK_ASSERT(sc);
438
439 carp_hmac_generate(sc, counter, md2);
440
441 return (bcmp(md, md2, sizeof(md2)));
442 }
443
444 /*
445 * process input packet.
446 * we have rearranged checks order compared to the rfc,
447 * but it seems more efficient this way or not possible otherwise.
448 */
449 #ifdef INET
450 int
carp_input(struct mbuf ** mp,int * offp,int proto)451 carp_input(struct mbuf **mp, int *offp, int proto)
452 {
453 struct mbuf *m = *mp;
454 struct ip *ip = mtod(m, struct ip *);
455 struct carp_header *ch;
456 int iplen, len;
457
458 iplen = *offp;
459 *mp = NULL;
460
461 CARPSTATS_INC(carps_ipackets);
462
463 if (!V_carp_allow) {
464 m_freem(m);
465 return (IPPROTO_DONE);
466 }
467
468 /* verify that the IP TTL is 255. */
469 if (ip->ip_ttl != CARP_DFLTTL) {
470 CARPSTATS_INC(carps_badttl);
471 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
472 ip->ip_ttl,
473 m->m_pkthdr.rcvif->if_xname);
474 m_freem(m);
475 return (IPPROTO_DONE);
476 }
477
478 iplen = ip->ip_hl << 2;
479
480 if (m->m_pkthdr.len < iplen + sizeof(*ch)) {
481 CARPSTATS_INC(carps_badlen);
482 CARP_DEBUG("%s: received len %zd < sizeof(struct carp_header) "
483 "on %s\n", __func__, m->m_len - sizeof(struct ip),
484 m->m_pkthdr.rcvif->if_xname);
485 m_freem(m);
486 return (IPPROTO_DONE);
487 }
488
489 if (iplen + sizeof(*ch) < m->m_len) {
490 if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) {
491 CARPSTATS_INC(carps_hdrops);
492 CARP_DEBUG("%s: pullup failed\n", __func__);
493 return (IPPROTO_DONE);
494 }
495 ip = mtod(m, struct ip *);
496 }
497 ch = (struct carp_header *)((char *)ip + iplen);
498
499 /*
500 * verify that the received packet length is
501 * equal to the CARP header
502 */
503 len = iplen + sizeof(*ch);
504 if (len > m->m_pkthdr.len) {
505 CARPSTATS_INC(carps_badlen);
506 CARP_DEBUG("%s: packet too short %d on %s\n", __func__,
507 m->m_pkthdr.len,
508 m->m_pkthdr.rcvif->if_xname);
509 m_freem(m);
510 return (IPPROTO_DONE);
511 }
512
513 if ((m = m_pullup(m, len)) == NULL) {
514 CARPSTATS_INC(carps_hdrops);
515 return (IPPROTO_DONE);
516 }
517 ip = mtod(m, struct ip *);
518 ch = (struct carp_header *)((char *)ip + iplen);
519
520 /* verify the CARP checksum */
521 m->m_data += iplen;
522 if (in_cksum(m, len - iplen)) {
523 CARPSTATS_INC(carps_badsum);
524 CARP_DEBUG("%s: checksum failed on %s\n", __func__,
525 m->m_pkthdr.rcvif->if_xname);
526 m_freem(m);
527 return (IPPROTO_DONE);
528 }
529 m->m_data -= iplen;
530
531 carp_input_c(m, ch, AF_INET);
532 return (IPPROTO_DONE);
533 }
534 #endif
535
536 #ifdef INET6
537 int
carp6_input(struct mbuf ** mp,int * offp,int proto)538 carp6_input(struct mbuf **mp, int *offp, int proto)
539 {
540 struct mbuf *m = *mp;
541 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
542 struct carp_header *ch;
543 u_int len;
544
545 CARPSTATS_INC(carps_ipackets6);
546
547 if (!V_carp_allow) {
548 m_freem(m);
549 return (IPPROTO_DONE);
550 }
551
552 /* check if received on a valid carp interface */
553 if (m->m_pkthdr.rcvif->if_carp == NULL) {
554 CARPSTATS_INC(carps_badif);
555 CARP_DEBUG("%s: packet received on non-carp interface: %s\n",
556 __func__, m->m_pkthdr.rcvif->if_xname);
557 m_freem(m);
558 return (IPPROTO_DONE);
559 }
560
561 /* verify that the IP TTL is 255 */
562 if (ip6->ip6_hlim != CARP_DFLTTL) {
563 CARPSTATS_INC(carps_badttl);
564 CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__,
565 ip6->ip6_hlim, m->m_pkthdr.rcvif->if_xname);
566 m_freem(m);
567 return (IPPROTO_DONE);
568 }
569
570 /* verify that we have a complete carp packet */
571 if (m->m_len < *offp + sizeof(*ch)) {
572 len = m->m_len;
573 m = m_pullup(m, *offp + sizeof(*ch));
574 if (m == NULL) {
575 CARPSTATS_INC(carps_badlen);
576 CARP_DEBUG("%s: packet size %u too small\n", __func__, len);
577 return (IPPROTO_DONE);
578 }
579 }
580 ch = (struct carp_header *)(mtod(m, char *) + *offp);
581
582
583 /* verify the CARP checksum */
584 m->m_data += *offp;
585 if (in_cksum(m, sizeof(*ch))) {
586 CARPSTATS_INC(carps_badsum);
587 CARP_DEBUG("%s: checksum failed, on %s\n", __func__,
588 m->m_pkthdr.rcvif->if_xname);
589 m_freem(m);
590 return (IPPROTO_DONE);
591 }
592 m->m_data -= *offp;
593
594 carp_input_c(m, ch, AF_INET6);
595 return (IPPROTO_DONE);
596 }
597 #endif /* INET6 */
598
599 /*
600 * This routine should not be necessary at all, but some switches
601 * (VMWare ESX vswitches) can echo our own packets back at us,
602 * and we must ignore them or they will cause us to drop out of
603 * MASTER mode.
604 *
605 * We cannot catch all cases of network loops. Instead, what we
606 * do here is catch any packet that arrives with a carp header
607 * with a VHID of 0, that comes from an address that is our own.
608 * These packets are by definition "from us" (even if they are from
609 * a misconfigured host that is pretending to be us).
610 *
611 * The VHID test is outside this mini-function.
612 */
613 static int
carp_source_is_self(struct mbuf * m,struct ifaddr * ifa,sa_family_t af)614 carp_source_is_self(struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
615 {
616 #ifdef INET
617 struct ip *ip4;
618 struct in_addr in4;
619 #endif
620 #ifdef INET6
621 struct ip6_hdr *ip6;
622 struct in6_addr in6;
623 #endif
624
625 switch (af) {
626 #ifdef INET
627 case AF_INET:
628 ip4 = mtod(m, struct ip *);
629 in4 = ifatoia(ifa)->ia_addr.sin_addr;
630 return (in4.s_addr == ip4->ip_src.s_addr);
631 #endif
632 #ifdef INET6
633 case AF_INET6:
634 ip6 = mtod(m, struct ip6_hdr *);
635 in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
636 return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
637 #endif
638 default:
639 break;
640 }
641 return (0);
642 }
643
644 static void
carp_input_c(struct mbuf * m,struct carp_header * ch,sa_family_t af)645 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
646 {
647 struct ifnet *ifp = m->m_pkthdr.rcvif;
648 struct ifaddr *ifa, *match;
649 struct carp_softc *sc;
650 uint64_t tmp_counter;
651 struct timeval sc_tv, ch_tv;
652 int error;
653
654 /*
655 * Verify that the VHID is valid on the receiving interface.
656 *
657 * There should be just one match. If there are none
658 * the VHID is not valid and we drop the packet. If
659 * there are multiple VHID matches, take just the first
660 * one, for compatibility with previous code. While we're
661 * scanning, check for obvious loops in the network topology
662 * (these should never happen, and as noted above, we may
663 * miss real loops; this is just a double-check).
664 */
665 IF_ADDR_RLOCK(ifp);
666 error = 0;
667 match = NULL;
668 IFNET_FOREACH_IFA(ifp, ifa) {
669 if (match == NULL && ifa->ifa_carp != NULL &&
670 ifa->ifa_addr->sa_family == af &&
671 ifa->ifa_carp->sc_vhid == ch->carp_vhid)
672 match = ifa;
673 if (ch->carp_vhid == 0 && carp_source_is_self(m, ifa, af))
674 error = ELOOP;
675 }
676 ifa = error ? NULL : match;
677 if (ifa != NULL)
678 ifa_ref(ifa);
679 IF_ADDR_RUNLOCK(ifp);
680
681 if (ifa == NULL) {
682 if (error == ELOOP) {
683 CARP_DEBUG("dropping looped packet on interface %s\n",
684 ifp->if_xname);
685 CARPSTATS_INC(carps_badif); /* ??? */
686 } else {
687 CARPSTATS_INC(carps_badvhid);
688 }
689 m_freem(m);
690 return;
691 }
692
693 /* verify the CARP version. */
694 if (ch->carp_version != CARP_VERSION) {
695 CARPSTATS_INC(carps_badver);
696 CARP_DEBUG("%s: invalid version %d\n", ifp->if_xname,
697 ch->carp_version);
698 ifa_free(ifa);
699 m_freem(m);
700 return;
701 }
702
703 sc = ifa->ifa_carp;
704 CARP_LOCK(sc);
705 ifa_free(ifa);
706
707 if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) {
708 CARPSTATS_INC(carps_badauth);
709 CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__,
710 sc->sc_vhid, ifp->if_xname);
711 goto out;
712 }
713
714 tmp_counter = ntohl(ch->carp_counter[0]);
715 tmp_counter = tmp_counter<<32;
716 tmp_counter += ntohl(ch->carp_counter[1]);
717
718 /* XXX Replay protection goes here */
719
720 sc->sc_init_counter = 0;
721 sc->sc_counter = tmp_counter;
722
723 sc_tv.tv_sec = sc->sc_advbase;
724 sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256;
725 ch_tv.tv_sec = ch->carp_advbase;
726 ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256;
727
728 switch (sc->sc_state) {
729 case INIT:
730 break;
731 case MASTER:
732 /*
733 * If we receive an advertisement from a master who's going to
734 * be more frequent than us, go into BACKUP state.
735 */
736 if (timevalcmp(&sc_tv, &ch_tv, >) ||
737 timevalcmp(&sc_tv, &ch_tv, ==)) {
738 callout_stop(&sc->sc_ad_tmo);
739 carp_set_state(sc, BACKUP,
740 "more frequent advertisement received");
741 carp_setrun(sc, 0);
742 carp_delroute(sc);
743 }
744 break;
745 case BACKUP:
746 /*
747 * If we're pre-empting masters who advertise slower than us,
748 * and this one claims to be slower, treat him as down.
749 */
750 if (V_carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) {
751 carp_master_down_locked(sc,
752 "preempting a slower master");
753 break;
754 }
755
756 /*
757 * If the master is going to advertise at such a low frequency
758 * that he's guaranteed to time out, we'd might as well just
759 * treat him as timed out now.
760 */
761 sc_tv.tv_sec = sc->sc_advbase * 3;
762 if (timevalcmp(&sc_tv, &ch_tv, <)) {
763 carp_master_down_locked(sc, "master will time out");
764 break;
765 }
766
767 /*
768 * Otherwise, we reset the counter and wait for the next
769 * advertisement.
770 */
771 carp_setrun(sc, af);
772 break;
773 }
774
775 out:
776 CARP_UNLOCK(sc);
777 m_freem(m);
778 }
779
780 static int
carp_prepare_ad(struct mbuf * m,struct carp_softc * sc,struct carp_header * ch)781 carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch)
782 {
783 struct m_tag *mtag;
784
785 if (sc->sc_init_counter) {
786 /* this could also be seconds since unix epoch */
787 sc->sc_counter = arc4random();
788 sc->sc_counter = sc->sc_counter << 32;
789 sc->sc_counter += arc4random();
790 } else
791 sc->sc_counter++;
792
793 ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff);
794 ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff);
795
796 carp_hmac_generate(sc, ch->carp_counter, ch->carp_md);
797
798 /* Tag packet for carp_output */
799 if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *),
800 M_NOWAIT)) == NULL) {
801 m_freem(m);
802 CARPSTATS_INC(carps_onomem);
803 return (ENOMEM);
804 }
805 bcopy(&sc, mtag + 1, sizeof(sc));
806 m_tag_prepend(m, mtag);
807
808 return (0);
809 }
810
811 /*
812 * To avoid LORs and possible recursions this function shouldn't
813 * be called directly, but scheduled via taskqueue.
814 */
815 static void
carp_send_ad_all(void * ctx __unused,int pending __unused)816 carp_send_ad_all(void *ctx __unused, int pending __unused)
817 {
818 struct carp_softc *sc;
819
820 mtx_lock(&carp_mtx);
821 LIST_FOREACH(sc, &carp_list, sc_next)
822 if (sc->sc_state == MASTER) {
823 CARP_LOCK(sc);
824 CURVNET_SET(sc->sc_carpdev->if_vnet);
825 carp_send_ad_locked(sc);
826 CURVNET_RESTORE();
827 CARP_UNLOCK(sc);
828 }
829 mtx_unlock(&carp_mtx);
830 }
831
832 /* Send a periodic advertisement, executed in callout context. */
833 static void
carp_send_ad(void * v)834 carp_send_ad(void *v)
835 {
836 struct carp_softc *sc = v;
837
838 CARP_LOCK_ASSERT(sc);
839 CURVNET_SET(sc->sc_carpdev->if_vnet);
840 carp_send_ad_locked(sc);
841 CURVNET_RESTORE();
842 CARP_UNLOCK(sc);
843 }
844
845 static void
carp_send_ad_error(struct carp_softc * sc,int error)846 carp_send_ad_error(struct carp_softc *sc, int error)
847 {
848
849 if (error) {
850 if (sc->sc_sendad_errors < INT_MAX)
851 sc->sc_sendad_errors++;
852 if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) {
853 static const char fmt[] = "send error %d on %s";
854 char msg[sizeof(fmt) + IFNAMSIZ];
855
856 sprintf(msg, fmt, error, sc->sc_carpdev->if_xname);
857 carp_demote_adj(V_carp_senderr_adj, msg);
858 }
859 sc->sc_sendad_success = 0;
860 } else {
861 if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS &&
862 ++sc->sc_sendad_success >= CARP_SENDAD_MIN_SUCCESS) {
863 static const char fmt[] = "send ok on %s";
864 char msg[sizeof(fmt) + IFNAMSIZ];
865
866 sprintf(msg, fmt, sc->sc_carpdev->if_xname);
867 carp_demote_adj(-V_carp_senderr_adj, msg);
868 sc->sc_sendad_errors = 0;
869 } else
870 sc->sc_sendad_errors = 0;
871 }
872 }
873
874 /*
875 * Pick the best ifaddr on the given ifp for sending CARP
876 * advertisements.
877 *
878 * "Best" here is defined by ifa_preferred(). This function is much
879 * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
880 *
881 * (This could be simplified to return the actual address, except that
882 * it has a different format in AF_INET and AF_INET6.)
883 */
884 static struct ifaddr *
carp_best_ifa(int af,struct ifnet * ifp)885 carp_best_ifa(int af, struct ifnet *ifp)
886 {
887 struct ifaddr *ifa, *best;
888
889 if (af >= AF_MAX)
890 return (NULL);
891 best = NULL;
892 IF_ADDR_RLOCK(ifp);
893 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
894 if (ifa->ifa_addr->sa_family == af &&
895 (best == NULL || ifa_preferred(best, ifa)))
896 best = ifa;
897 }
898 IF_ADDR_RUNLOCK(ifp);
899 if (best != NULL)
900 ifa_ref(best);
901 return (best);
902 }
903
904 static void
carp_send_ad_locked(struct carp_softc * sc)905 carp_send_ad_locked(struct carp_softc *sc)
906 {
907 struct carp_header ch;
908 struct timeval tv;
909 struct ifaddr *ifa;
910 struct carp_header *ch_ptr;
911 struct mbuf *m;
912 int len, advskew;
913
914 CARP_LOCK_ASSERT(sc);
915
916 advskew = DEMOTE_ADVSKEW(sc);
917 tv.tv_sec = sc->sc_advbase;
918 tv.tv_usec = advskew * 1000000 / 256;
919
920 ch.carp_version = CARP_VERSION;
921 ch.carp_type = CARP_ADVERTISEMENT;
922 ch.carp_vhid = sc->sc_vhid;
923 ch.carp_advbase = sc->sc_advbase;
924 ch.carp_advskew = advskew;
925 ch.carp_authlen = 7; /* XXX DEFINE */
926 ch.carp_pad1 = 0; /* must be zero */
927 ch.carp_cksum = 0;
928
929 /* XXXGL: OpenBSD picks first ifaddr with needed family. */
930
931 #ifdef INET
932 if (sc->sc_naddrs) {
933 struct ip *ip;
934
935 m = m_gethdr(M_NOWAIT, MT_DATA);
936 if (m == NULL) {
937 CARPSTATS_INC(carps_onomem);
938 goto resched;
939 }
940 len = sizeof(*ip) + sizeof(ch);
941 m->m_pkthdr.len = len;
942 m->m_pkthdr.rcvif = NULL;
943 m->m_len = len;
944 M_ALIGN(m, m->m_len);
945 m->m_flags |= M_MCAST;
946 ip = mtod(m, struct ip *);
947 ip->ip_v = IPVERSION;
948 ip->ip_hl = sizeof(*ip) >> 2;
949 ip->ip_tos = V_carp_dscp << IPTOS_DSCP_OFFSET;
950 ip->ip_len = htons(len);
951 ip->ip_off = htons(IP_DF);
952 ip->ip_ttl = CARP_DFLTTL;
953 ip->ip_p = IPPROTO_CARP;
954 ip->ip_sum = 0;
955 ip_fillid(ip);
956
957 ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
958 if (ifa != NULL) {
959 ip->ip_src.s_addr =
960 ifatoia(ifa)->ia_addr.sin_addr.s_addr;
961 ifa_free(ifa);
962 } else
963 ip->ip_src.s_addr = 0;
964 ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP);
965
966 ch_ptr = (struct carp_header *)(&ip[1]);
967 bcopy(&ch, ch_ptr, sizeof(ch));
968 if (carp_prepare_ad(m, sc, ch_ptr))
969 goto resched;
970
971 m->m_data += sizeof(*ip);
972 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip));
973 m->m_data -= sizeof(*ip);
974
975 CARPSTATS_INC(carps_opackets);
976
977 carp_send_ad_error(sc, ip_output(m, NULL, NULL, IP_RAWOUTPUT,
978 &sc->sc_carpdev->if_carp->cif_imo, NULL));
979 }
980 #endif /* INET */
981 #ifdef INET6
982 if (sc->sc_naddrs6) {
983 struct ip6_hdr *ip6;
984
985 m = m_gethdr(M_NOWAIT, MT_DATA);
986 if (m == NULL) {
987 CARPSTATS_INC(carps_onomem);
988 goto resched;
989 }
990 len = sizeof(*ip6) + sizeof(ch);
991 m->m_pkthdr.len = len;
992 m->m_pkthdr.rcvif = NULL;
993 m->m_len = len;
994 M_ALIGN(m, m->m_len);
995 m->m_flags |= M_MCAST;
996 ip6 = mtod(m, struct ip6_hdr *);
997 bzero(ip6, sizeof(*ip6));
998 ip6->ip6_vfc |= IPV6_VERSION;
999 /* Traffic class isn't defined in ip6 struct instead
1000 * it gets offset into flowid field */
1001 ip6->ip6_flow |= htonl(V_carp_dscp << (IPV6_FLOWLABEL_LEN +
1002 IPTOS_DSCP_OFFSET));
1003 ip6->ip6_hlim = CARP_DFLTTL;
1004 ip6->ip6_nxt = IPPROTO_CARP;
1005
1006 /* set the source address */
1007 ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
1008 if (ifa != NULL) {
1009 bcopy(IFA_IN6(ifa), &ip6->ip6_src,
1010 sizeof(struct in6_addr));
1011 ifa_free(ifa);
1012 } else
1013 /* This should never happen with IPv6. */
1014 bzero(&ip6->ip6_src, sizeof(struct in6_addr));
1015
1016 /* Set the multicast destination. */
1017 ip6->ip6_dst.s6_addr16[0] = htons(0xff02);
1018 ip6->ip6_dst.s6_addr8[15] = 0x12;
1019 if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) {
1020 m_freem(m);
1021 CARP_DEBUG("%s: in6_setscope failed\n", __func__);
1022 goto resched;
1023 }
1024
1025 ch_ptr = (struct carp_header *)(&ip6[1]);
1026 bcopy(&ch, ch_ptr, sizeof(ch));
1027 if (carp_prepare_ad(m, sc, ch_ptr))
1028 goto resched;
1029
1030 m->m_data += sizeof(*ip6);
1031 ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6));
1032 m->m_data -= sizeof(*ip6);
1033
1034 CARPSTATS_INC(carps_opackets6);
1035
1036 carp_send_ad_error(sc, ip6_output(m, NULL, NULL, 0,
1037 &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL));
1038 }
1039 #endif /* INET6 */
1040
1041 resched:
1042 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc);
1043 }
1044
1045 static void
carp_addroute(struct carp_softc * sc)1046 carp_addroute(struct carp_softc *sc)
1047 {
1048 struct ifaddr *ifa;
1049
1050 CARP_FOREACH_IFA(sc, ifa)
1051 carp_ifa_addroute(ifa);
1052 }
1053
1054 static void
carp_ifa_addroute(struct ifaddr * ifa)1055 carp_ifa_addroute(struct ifaddr *ifa)
1056 {
1057
1058 switch (ifa->ifa_addr->sa_family) {
1059 #ifdef INET
1060 case AF_INET:
1061 in_addprefix(ifatoia(ifa), RTF_UP);
1062 ifa_add_loopback_route(ifa,
1063 (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1064 break;
1065 #endif
1066 #ifdef INET6
1067 case AF_INET6:
1068 ifa_add_loopback_route(ifa,
1069 (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1070 nd6_add_ifa_lle(ifatoia6(ifa));
1071 break;
1072 #endif
1073 }
1074 }
1075
1076 static void
carp_delroute(struct carp_softc * sc)1077 carp_delroute(struct carp_softc *sc)
1078 {
1079 struct ifaddr *ifa;
1080
1081 CARP_FOREACH_IFA(sc, ifa)
1082 carp_ifa_delroute(ifa);
1083 }
1084
1085 static void
carp_ifa_delroute(struct ifaddr * ifa)1086 carp_ifa_delroute(struct ifaddr *ifa)
1087 {
1088
1089 switch (ifa->ifa_addr->sa_family) {
1090 #ifdef INET
1091 case AF_INET:
1092 ifa_del_loopback_route(ifa,
1093 (struct sockaddr *)&ifatoia(ifa)->ia_addr);
1094 in_scrubprefix(ifatoia(ifa), LLE_STATIC);
1095 break;
1096 #endif
1097 #ifdef INET6
1098 case AF_INET6:
1099 ifa_del_loopback_route(ifa,
1100 (struct sockaddr *)&ifatoia6(ifa)->ia_addr);
1101 nd6_rem_ifa_lle(ifatoia6(ifa), 1);
1102 break;
1103 #endif
1104 }
1105 }
1106
1107 int
carp_master(struct ifaddr * ifa)1108 carp_master(struct ifaddr *ifa)
1109 {
1110 struct carp_softc *sc = ifa->ifa_carp;
1111
1112 return (sc->sc_state == MASTER);
1113 }
1114
1115 #ifdef INET
1116 /*
1117 * Broadcast a gratuitous ARP request containing
1118 * the virtual router MAC address for each IP address
1119 * associated with the virtual router.
1120 */
1121 static void
carp_send_arp(struct carp_softc * sc)1122 carp_send_arp(struct carp_softc *sc)
1123 {
1124 struct ifaddr *ifa;
1125 struct in_addr addr;
1126
1127 CARP_FOREACH_IFA(sc, ifa) {
1128 if (ifa->ifa_addr->sa_family != AF_INET)
1129 continue;
1130 addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
1131 arp_announce_ifaddr(sc->sc_carpdev, addr, LLADDR(&sc->sc_addr));
1132 }
1133 }
1134
1135 int
carp_iamatch(struct ifaddr * ifa,uint8_t ** enaddr)1136 carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr)
1137 {
1138 struct carp_softc *sc = ifa->ifa_carp;
1139
1140 if (sc->sc_state == MASTER) {
1141 *enaddr = LLADDR(&sc->sc_addr);
1142 return (1);
1143 }
1144
1145 return (0);
1146 }
1147 #endif
1148
1149 #ifdef INET6
1150 static void
carp_send_na(struct carp_softc * sc)1151 carp_send_na(struct carp_softc *sc)
1152 {
1153 static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
1154 struct ifaddr *ifa;
1155 struct in6_addr *in6;
1156
1157 CARP_FOREACH_IFA(sc, ifa) {
1158 if (ifa->ifa_addr->sa_family != AF_INET6)
1159 continue;
1160
1161 in6 = IFA_IN6(ifa);
1162 nd6_na_output(sc->sc_carpdev, &mcast, in6,
1163 ND_NA_FLAG_OVERRIDE, 1, NULL);
1164 DELAY(1000); /* XXX */
1165 }
1166 }
1167
1168 /*
1169 * Returns ifa in case it's a carp address and it is MASTER, or if the address
1170 * matches and is not a carp address. Returns NULL otherwise.
1171 */
1172 struct ifaddr *
carp_iamatch6(struct ifnet * ifp,struct in6_addr * taddr)1173 carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr)
1174 {
1175 struct ifaddr *ifa;
1176
1177 ifa = NULL;
1178 IF_ADDR_RLOCK(ifp);
1179 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1180 if (ifa->ifa_addr->sa_family != AF_INET6)
1181 continue;
1182 if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa)))
1183 continue;
1184 if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER)
1185 ifa = NULL;
1186 else
1187 ifa_ref(ifa);
1188 break;
1189 }
1190 IF_ADDR_RUNLOCK(ifp);
1191
1192 return (ifa);
1193 }
1194
1195 char *
carp_macmatch6(struct ifnet * ifp,struct mbuf * m,const struct in6_addr * taddr)1196 carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr)
1197 {
1198 struct ifaddr *ifa;
1199
1200 IF_ADDR_RLOCK(ifp);
1201 IFNET_FOREACH_IFA(ifp, ifa)
1202 if (ifa->ifa_addr->sa_family == AF_INET6 &&
1203 IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) {
1204 struct carp_softc *sc = ifa->ifa_carp;
1205 struct m_tag *mtag;
1206
1207 IF_ADDR_RUNLOCK(ifp);
1208
1209 mtag = m_tag_get(PACKET_TAG_CARP,
1210 sizeof(struct carp_softc *), M_NOWAIT);
1211 if (mtag == NULL)
1212 /* Better a bit than nothing. */
1213 return (LLADDR(&sc->sc_addr));
1214
1215 bcopy(&sc, mtag + 1, sizeof(sc));
1216 m_tag_prepend(m, mtag);
1217
1218 return (LLADDR(&sc->sc_addr));
1219 }
1220 IF_ADDR_RUNLOCK(ifp);
1221
1222 return (NULL);
1223 }
1224 #endif /* INET6 */
1225
1226 int
carp_forus(struct ifnet * ifp,u_char * dhost)1227 carp_forus(struct ifnet *ifp, u_char *dhost)
1228 {
1229 struct carp_softc *sc;
1230 uint8_t *ena = dhost;
1231
1232 if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1)
1233 return (0);
1234
1235 CIF_LOCK(ifp->if_carp);
1236 IFNET_FOREACH_CARP(ifp, sc) {
1237 /*
1238 * CARP_LOCK() is not here, since would protect nothing, but
1239 * cause deadlock with if_bridge, calling this under its lock.
1240 */
1241 if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr),
1242 ETHER_ADDR_LEN)) {
1243 CIF_UNLOCK(ifp->if_carp);
1244 return (1);
1245 }
1246 }
1247 CIF_UNLOCK(ifp->if_carp);
1248
1249 return (0);
1250 }
1251
1252 /* Master down timeout event, executed in callout context. */
1253 static void
carp_master_down(void * v)1254 carp_master_down(void *v)
1255 {
1256 struct carp_softc *sc = v;
1257
1258 CARP_LOCK_ASSERT(sc);
1259
1260 CURVNET_SET(sc->sc_carpdev->if_vnet);
1261 if (sc->sc_state == BACKUP) {
1262 carp_master_down_locked(sc, "master timed out");
1263 }
1264 CURVNET_RESTORE();
1265
1266 CARP_UNLOCK(sc);
1267 }
1268
1269 static void
carp_master_down_locked(struct carp_softc * sc,const char * reason)1270 carp_master_down_locked(struct carp_softc *sc, const char *reason)
1271 {
1272
1273 CARP_LOCK_ASSERT(sc);
1274
1275 switch (sc->sc_state) {
1276 case BACKUP:
1277 carp_set_state(sc, MASTER, reason);
1278 carp_send_ad_locked(sc);
1279 #ifdef INET
1280 carp_send_arp(sc);
1281 #endif
1282 #ifdef INET6
1283 carp_send_na(sc);
1284 #endif
1285 carp_setrun(sc, 0);
1286 carp_addroute(sc);
1287 break;
1288 case INIT:
1289 case MASTER:
1290 #ifdef INVARIANTS
1291 panic("carp: VHID %u@%s: master_down event in %s state\n",
1292 sc->sc_vhid,
1293 sc->sc_carpdev->if_xname,
1294 sc->sc_state ? "MASTER" : "INIT");
1295 #endif
1296 break;
1297 }
1298 }
1299
1300 /*
1301 * When in backup state, af indicates whether to reset the master down timer
1302 * for v4 or v6. If it's set to zero, reset the ones which are already pending.
1303 */
1304 static void
carp_setrun(struct carp_softc * sc,sa_family_t af)1305 carp_setrun(struct carp_softc *sc, sa_family_t af)
1306 {
1307 struct timeval tv;
1308
1309 CARP_LOCK_ASSERT(sc);
1310
1311 if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 ||
1312 sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
1313 (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) ||
1314 !V_carp_allow)
1315 return;
1316
1317 switch (sc->sc_state) {
1318 case INIT:
1319 carp_set_state(sc, BACKUP, "initialization complete");
1320 carp_setrun(sc, 0);
1321 break;
1322 case BACKUP:
1323 callout_stop(&sc->sc_ad_tmo);
1324 tv.tv_sec = 3 * sc->sc_advbase;
1325 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1326 switch (af) {
1327 #ifdef INET
1328 case AF_INET:
1329 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1330 carp_master_down, sc);
1331 break;
1332 #endif
1333 #ifdef INET6
1334 case AF_INET6:
1335 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1336 carp_master_down, sc);
1337 break;
1338 #endif
1339 default:
1340 #ifdef INET
1341 if (sc->sc_naddrs)
1342 callout_reset(&sc->sc_md_tmo, tvtohz(&tv),
1343 carp_master_down, sc);
1344 #endif
1345 #ifdef INET6
1346 if (sc->sc_naddrs6)
1347 callout_reset(&sc->sc_md6_tmo, tvtohz(&tv),
1348 carp_master_down, sc);
1349 #endif
1350 break;
1351 }
1352 break;
1353 case MASTER:
1354 tv.tv_sec = sc->sc_advbase;
1355 tv.tv_usec = sc->sc_advskew * 1000000 / 256;
1356 callout_reset(&sc->sc_ad_tmo, tvtohz(&tv),
1357 carp_send_ad, sc);
1358 break;
1359 }
1360 }
1361
1362 /*
1363 * Setup multicast structures.
1364 */
1365 static int
carp_multicast_setup(struct carp_if * cif,sa_family_t sa)1366 carp_multicast_setup(struct carp_if *cif, sa_family_t sa)
1367 {
1368 struct ifnet *ifp = cif->cif_ifp;
1369 int error = 0;
1370
1371 switch (sa) {
1372 #ifdef INET
1373 case AF_INET:
1374 {
1375 struct ip_moptions *imo = &cif->cif_imo;
1376 struct in_mfilter *imf;
1377 struct in_addr addr;
1378
1379 if (ip_mfilter_first(&imo->imo_head) != NULL)
1380 return (0);
1381
1382 imf = ip_mfilter_alloc(M_WAITOK, 0, 0);
1383 ip_mfilter_init(&imo->imo_head);
1384 imo->imo_multicast_vif = -1;
1385
1386 addr.s_addr = htonl(INADDR_CARP_GROUP);
1387 if ((error = in_joingroup(ifp, &addr, NULL,
1388 &imf->imf_inm)) != 0) {
1389 ip_mfilter_free(imf);
1390 break;
1391 }
1392
1393 ip_mfilter_insert(&imo->imo_head, imf);
1394 imo->imo_multicast_ifp = ifp;
1395 imo->imo_multicast_ttl = CARP_DFLTTL;
1396 imo->imo_multicast_loop = 0;
1397 break;
1398 }
1399 #endif
1400 #ifdef INET6
1401 case AF_INET6:
1402 {
1403 struct ip6_moptions *im6o = &cif->cif_im6o;
1404 struct in6_mfilter *im6f[2];
1405 struct in6_addr in6;
1406
1407 if (ip6_mfilter_first(&im6o->im6o_head))
1408 return (0);
1409
1410 im6f[0] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1411 im6f[1] = ip6_mfilter_alloc(M_WAITOK, 0, 0);
1412
1413 ip6_mfilter_init(&im6o->im6o_head);
1414 im6o->im6o_multicast_hlim = CARP_DFLTTL;
1415 im6o->im6o_multicast_ifp = ifp;
1416
1417 /* Join IPv6 CARP multicast group. */
1418 bzero(&in6, sizeof(in6));
1419 in6.s6_addr16[0] = htons(0xff02);
1420 in6.s6_addr8[15] = 0x12;
1421 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1422 ip6_mfilter_free(im6f[0]);
1423 ip6_mfilter_free(im6f[1]);
1424 break;
1425 }
1426 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[0]->im6f_in6m, 0)) != 0) {
1427 ip6_mfilter_free(im6f[0]);
1428 ip6_mfilter_free(im6f[1]);
1429 break;
1430 }
1431
1432 /* Join solicited multicast address. */
1433 bzero(&in6, sizeof(in6));
1434 in6.s6_addr16[0] = htons(0xff02);
1435 in6.s6_addr32[1] = 0;
1436 in6.s6_addr32[2] = htonl(1);
1437 in6.s6_addr32[3] = 0;
1438 in6.s6_addr8[12] = 0xff;
1439
1440 if ((error = in6_setscope(&in6, ifp, NULL)) != 0) {
1441 ip6_mfilter_free(im6f[0]);
1442 ip6_mfilter_free(im6f[1]);
1443 break;
1444 }
1445
1446 if ((error = in6_joingroup(ifp, &in6, NULL, &im6f[1]->im6f_in6m, 0)) != 0) {
1447 in6_leavegroup(im6f[0]->im6f_in6m, NULL);
1448 ip6_mfilter_free(im6f[0]);
1449 ip6_mfilter_free(im6f[1]);
1450 break;
1451 }
1452 ip6_mfilter_insert(&im6o->im6o_head, im6f[0]);
1453 ip6_mfilter_insert(&im6o->im6o_head, im6f[1]);
1454 break;
1455 }
1456 #endif
1457 }
1458
1459 return (error);
1460 }
1461
1462 /*
1463 * Free multicast structures.
1464 */
1465 static void
carp_multicast_cleanup(struct carp_if * cif,sa_family_t sa)1466 carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa)
1467 {
1468 #ifdef INET
1469 struct ip_moptions *imo = &cif->cif_imo;
1470 struct in_mfilter *imf;
1471 #endif
1472 #ifdef INET6
1473 struct ip6_moptions *im6o = &cif->cif_im6o;
1474 struct in6_mfilter *im6f;
1475 #endif
1476 sx_assert(&carp_sx, SA_XLOCKED);
1477
1478 switch (sa) {
1479 #ifdef INET
1480 case AF_INET:
1481 if (cif->cif_naddrs != 0)
1482 break;
1483
1484 while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
1485 ip_mfilter_remove(&imo->imo_head, imf);
1486 in_leavegroup(imf->imf_inm, NULL);
1487 ip_mfilter_free(imf);
1488 }
1489 break;
1490 #endif
1491 #ifdef INET6
1492 case AF_INET6:
1493 if (cif->cif_naddrs6 != 0)
1494 break;
1495
1496 while ((im6f = ip6_mfilter_first(&im6o->im6o_head)) != NULL) {
1497 ip6_mfilter_remove(&im6o->im6o_head, im6f);
1498 in6_leavegroup(im6f->im6f_in6m, NULL);
1499 ip6_mfilter_free(im6f);
1500 }
1501 break;
1502 #endif
1503 }
1504 }
1505
1506 int
carp_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * sa)1507 carp_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *sa)
1508 {
1509 struct m_tag *mtag;
1510 struct carp_softc *sc;
1511
1512 if (!sa)
1513 return (0);
1514
1515 switch (sa->sa_family) {
1516 #ifdef INET
1517 case AF_INET:
1518 break;
1519 #endif
1520 #ifdef INET6
1521 case AF_INET6:
1522 break;
1523 #endif
1524 default:
1525 return (0);
1526 }
1527
1528 mtag = m_tag_find(m, PACKET_TAG_CARP, NULL);
1529 if (mtag == NULL)
1530 return (0);
1531
1532 bcopy(mtag + 1, &sc, sizeof(sc));
1533
1534 /* Set the source MAC address to the Virtual Router MAC Address. */
1535 switch (ifp->if_type) {
1536 case IFT_ETHER:
1537 case IFT_BRIDGE:
1538 case IFT_L2VLAN: {
1539 struct ether_header *eh;
1540
1541 eh = mtod(m, struct ether_header *);
1542 eh->ether_shost[0] = 0;
1543 eh->ether_shost[1] = 0;
1544 eh->ether_shost[2] = 0x5e;
1545 eh->ether_shost[3] = 0;
1546 eh->ether_shost[4] = 1;
1547 eh->ether_shost[5] = sc->sc_vhid;
1548 }
1549 break;
1550 default:
1551 printf("%s: carp is not supported for the %d interface type\n",
1552 ifp->if_xname, ifp->if_type);
1553 return (EOPNOTSUPP);
1554 }
1555
1556 return (0);
1557 }
1558
1559 static struct carp_softc*
carp_alloc(struct ifnet * ifp)1560 carp_alloc(struct ifnet *ifp)
1561 {
1562 struct carp_softc *sc;
1563 struct carp_if *cif;
1564
1565 sx_assert(&carp_sx, SA_XLOCKED);
1566
1567 if ((cif = ifp->if_carp) == NULL)
1568 cif = carp_alloc_if(ifp);
1569
1570 sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO);
1571
1572 sc->sc_advbase = CARP_DFLTINTV;
1573 sc->sc_vhid = -1; /* required setting */
1574 sc->sc_init_counter = 1;
1575 sc->sc_state = INIT;
1576
1577 sc->sc_ifasiz = sizeof(struct ifaddr *);
1578 sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO);
1579 sc->sc_carpdev = ifp;
1580
1581 CARP_LOCK_INIT(sc);
1582 #ifdef INET
1583 callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1584 #endif
1585 #ifdef INET6
1586 callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1587 #endif
1588 callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED);
1589
1590 CIF_LOCK(cif);
1591 TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list);
1592 CIF_UNLOCK(cif);
1593
1594 mtx_lock(&carp_mtx);
1595 LIST_INSERT_HEAD(&carp_list, sc, sc_next);
1596 mtx_unlock(&carp_mtx);
1597
1598 return (sc);
1599 }
1600
1601 static void
carp_grow_ifas(struct carp_softc * sc)1602 carp_grow_ifas(struct carp_softc *sc)
1603 {
1604 struct ifaddr **new;
1605
1606 new = malloc(sc->sc_ifasiz * 2, M_CARP, M_WAITOK | M_ZERO);
1607 CARP_LOCK(sc);
1608 bcopy(sc->sc_ifas, new, sc->sc_ifasiz);
1609 free(sc->sc_ifas, M_CARP);
1610 sc->sc_ifas = new;
1611 sc->sc_ifasiz *= 2;
1612 CARP_UNLOCK(sc);
1613 }
1614
1615 static void
carp_destroy(struct carp_softc * sc)1616 carp_destroy(struct carp_softc *sc)
1617 {
1618 struct ifnet *ifp = sc->sc_carpdev;
1619 struct carp_if *cif = ifp->if_carp;
1620
1621 sx_assert(&carp_sx, SA_XLOCKED);
1622
1623 if (sc->sc_suppress)
1624 carp_demote_adj(-V_carp_ifdown_adj, "vhid removed");
1625 CARP_UNLOCK(sc);
1626
1627 CIF_LOCK(cif);
1628 TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list);
1629 CIF_UNLOCK(cif);
1630
1631 mtx_lock(&carp_mtx);
1632 LIST_REMOVE(sc, sc_next);
1633 mtx_unlock(&carp_mtx);
1634
1635 callout_drain(&sc->sc_ad_tmo);
1636 #ifdef INET
1637 callout_drain(&sc->sc_md_tmo);
1638 #endif
1639 #ifdef INET6
1640 callout_drain(&sc->sc_md6_tmo);
1641 #endif
1642 CARP_LOCK_DESTROY(sc);
1643
1644 free(sc->sc_ifas, M_CARP);
1645 free(sc, M_CARP);
1646 }
1647
1648 static struct carp_if*
carp_alloc_if(struct ifnet * ifp)1649 carp_alloc_if(struct ifnet *ifp)
1650 {
1651 struct carp_if *cif;
1652 int error;
1653
1654 cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO);
1655
1656 if ((error = ifpromisc(ifp, 1)) != 0)
1657 printf("%s: ifpromisc(%s) failed: %d\n",
1658 __func__, ifp->if_xname, error);
1659 else
1660 cif->cif_flags |= CIF_PROMISC;
1661
1662 CIF_LOCK_INIT(cif);
1663 cif->cif_ifp = ifp;
1664 TAILQ_INIT(&cif->cif_vrs);
1665
1666 IF_ADDR_WLOCK(ifp);
1667 ifp->if_carp = cif;
1668 if_ref(ifp);
1669 IF_ADDR_WUNLOCK(ifp);
1670
1671 return (cif);
1672 }
1673
1674 static void
carp_free_if(struct carp_if * cif)1675 carp_free_if(struct carp_if *cif)
1676 {
1677 struct ifnet *ifp = cif->cif_ifp;
1678
1679 CIF_LOCK_ASSERT(cif);
1680 KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty",
1681 __func__));
1682
1683 IF_ADDR_WLOCK(ifp);
1684 ifp->if_carp = NULL;
1685 IF_ADDR_WUNLOCK(ifp);
1686
1687 CIF_LOCK_DESTROY(cif);
1688
1689 if (cif->cif_flags & CIF_PROMISC)
1690 ifpromisc(ifp, 0);
1691 if_rele(ifp);
1692
1693 free(cif, M_CARP);
1694 }
1695
1696 static void
carp_carprcp(struct carpreq * carpr,struct carp_softc * sc,int priv)1697 carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv)
1698 {
1699
1700 CARP_LOCK(sc);
1701 carpr->carpr_state = sc->sc_state;
1702 carpr->carpr_vhid = sc->sc_vhid;
1703 carpr->carpr_advbase = sc->sc_advbase;
1704 carpr->carpr_advskew = sc->sc_advskew;
1705 if (priv)
1706 bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key));
1707 else
1708 bzero(carpr->carpr_key, sizeof(carpr->carpr_key));
1709 CARP_UNLOCK(sc);
1710 }
1711
1712 int
carp_ioctl(struct ifreq * ifr,u_long cmd,struct thread * td)1713 carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td)
1714 {
1715 struct carpreq carpr;
1716 struct ifnet *ifp;
1717 struct carp_softc *sc = NULL;
1718 int error = 0, locked = 0;
1719
1720 if ((error = copyin(ifr_data_get_ptr(ifr), &carpr, sizeof carpr)))
1721 return (error);
1722
1723 ifp = ifunit_ref(ifr->ifr_name);
1724 if (ifp == NULL)
1725 return (ENXIO);
1726
1727 switch (ifp->if_type) {
1728 case IFT_ETHER:
1729 case IFT_L2VLAN:
1730 case IFT_BRIDGE:
1731 break;
1732 default:
1733 error = EOPNOTSUPP;
1734 goto out;
1735 }
1736
1737 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
1738 error = EADDRNOTAVAIL;
1739 goto out;
1740 }
1741
1742 sx_xlock(&carp_sx);
1743 switch (cmd) {
1744 case SIOCSVH:
1745 if ((error = priv_check(td, PRIV_NETINET_CARP)))
1746 break;
1747 if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID ||
1748 carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) {
1749 error = EINVAL;
1750 break;
1751 }
1752
1753 if (ifp->if_carp) {
1754 IFNET_FOREACH_CARP(ifp, sc)
1755 if (sc->sc_vhid == carpr.carpr_vhid)
1756 break;
1757 }
1758 if (sc == NULL) {
1759 sc = carp_alloc(ifp);
1760 CARP_LOCK(sc);
1761 sc->sc_vhid = carpr.carpr_vhid;
1762 LLADDR(&sc->sc_addr)[0] = 0;
1763 LLADDR(&sc->sc_addr)[1] = 0;
1764 LLADDR(&sc->sc_addr)[2] = 0x5e;
1765 LLADDR(&sc->sc_addr)[3] = 0;
1766 LLADDR(&sc->sc_addr)[4] = 1;
1767 LLADDR(&sc->sc_addr)[5] = sc->sc_vhid;
1768 } else
1769 CARP_LOCK(sc);
1770 locked = 1;
1771 if (carpr.carpr_advbase > 0) {
1772 if (carpr.carpr_advbase > 255 ||
1773 carpr.carpr_advbase < CARP_DFLTINTV) {
1774 error = EINVAL;
1775 break;
1776 }
1777 sc->sc_advbase = carpr.carpr_advbase;
1778 }
1779 if (carpr.carpr_advskew >= 255) {
1780 error = EINVAL;
1781 break;
1782 }
1783 sc->sc_advskew = carpr.carpr_advskew;
1784 if (carpr.carpr_key[0] != '\0') {
1785 bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key));
1786 carp_hmac_prepare(sc);
1787 }
1788 if (sc->sc_state != INIT &&
1789 carpr.carpr_state != sc->sc_state) {
1790 switch (carpr.carpr_state) {
1791 case BACKUP:
1792 callout_stop(&sc->sc_ad_tmo);
1793 carp_set_state(sc, BACKUP,
1794 "user requested via ifconfig");
1795 carp_setrun(sc, 0);
1796 carp_delroute(sc);
1797 break;
1798 case MASTER:
1799 carp_master_down_locked(sc,
1800 "user requested via ifconfig");
1801 break;
1802 default:
1803 break;
1804 }
1805 }
1806 break;
1807
1808 case SIOCGVH:
1809 {
1810 int priveleged;
1811
1812 if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) {
1813 error = EINVAL;
1814 break;
1815 }
1816 if (carpr.carpr_count < 1) {
1817 error = EMSGSIZE;
1818 break;
1819 }
1820 if (ifp->if_carp == NULL) {
1821 error = ENOENT;
1822 break;
1823 }
1824
1825 priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0);
1826 if (carpr.carpr_vhid != 0) {
1827 IFNET_FOREACH_CARP(ifp, sc)
1828 if (sc->sc_vhid == carpr.carpr_vhid)
1829 break;
1830 if (sc == NULL) {
1831 error = ENOENT;
1832 break;
1833 }
1834 carp_carprcp(&carpr, sc, priveleged);
1835 error = copyout(&carpr, ifr_data_get_ptr(ifr),
1836 sizeof(carpr));
1837 } else {
1838 int i, count;
1839
1840 count = 0;
1841 IFNET_FOREACH_CARP(ifp, sc)
1842 count++;
1843
1844 if (count > carpr.carpr_count) {
1845 CIF_UNLOCK(ifp->if_carp);
1846 error = EMSGSIZE;
1847 break;
1848 }
1849
1850 i = 0;
1851 IFNET_FOREACH_CARP(ifp, sc) {
1852 carp_carprcp(&carpr, sc, priveleged);
1853 carpr.carpr_count = count;
1854 error = copyout(&carpr,
1855 (char *)ifr_data_get_ptr(ifr) +
1856 (i * sizeof(carpr)), sizeof(carpr));
1857 if (error) {
1858 CIF_UNLOCK(ifp->if_carp);
1859 break;
1860 }
1861 i++;
1862 }
1863 }
1864 break;
1865 }
1866 default:
1867 error = EINVAL;
1868 }
1869 sx_xunlock(&carp_sx);
1870
1871 out:
1872 if (locked)
1873 CARP_UNLOCK(sc);
1874 if_rele(ifp);
1875
1876 return (error);
1877 }
1878
1879 static int
carp_get_vhid(struct ifaddr * ifa)1880 carp_get_vhid(struct ifaddr *ifa)
1881 {
1882
1883 if (ifa == NULL || ifa->ifa_carp == NULL)
1884 return (0);
1885
1886 return (ifa->ifa_carp->sc_vhid);
1887 }
1888
1889 int
carp_attach(struct ifaddr * ifa,int vhid)1890 carp_attach(struct ifaddr *ifa, int vhid)
1891 {
1892 struct ifnet *ifp = ifa->ifa_ifp;
1893 struct carp_if *cif = ifp->if_carp;
1894 struct carp_softc *sc;
1895 int index, error;
1896
1897 KASSERT(ifa->ifa_carp == NULL, ("%s: ifa %p attached", __func__, ifa));
1898
1899 switch (ifa->ifa_addr->sa_family) {
1900 #ifdef INET
1901 case AF_INET:
1902 #endif
1903 #ifdef INET6
1904 case AF_INET6:
1905 #endif
1906 break;
1907 default:
1908 return (EPROTOTYPE);
1909 }
1910
1911 sx_xlock(&carp_sx);
1912 if (ifp->if_carp == NULL) {
1913 sx_xunlock(&carp_sx);
1914 return (ENOPROTOOPT);
1915 }
1916
1917 IFNET_FOREACH_CARP(ifp, sc)
1918 if (sc->sc_vhid == vhid)
1919 break;
1920 if (sc == NULL) {
1921 sx_xunlock(&carp_sx);
1922 return (ENOENT);
1923 }
1924
1925 error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family);
1926 if (error) {
1927 CIF_FREE(cif);
1928 sx_xunlock(&carp_sx);
1929 return (error);
1930 }
1931
1932 index = sc->sc_naddrs + sc->sc_naddrs6 + 1;
1933 if (index > sc->sc_ifasiz / sizeof(struct ifaddr *))
1934 carp_grow_ifas(sc);
1935
1936 switch (ifa->ifa_addr->sa_family) {
1937 #ifdef INET
1938 case AF_INET:
1939 cif->cif_naddrs++;
1940 sc->sc_naddrs++;
1941 break;
1942 #endif
1943 #ifdef INET6
1944 case AF_INET6:
1945 cif->cif_naddrs6++;
1946 sc->sc_naddrs6++;
1947 break;
1948 #endif
1949 }
1950
1951 ifa_ref(ifa);
1952
1953 CARP_LOCK(sc);
1954 sc->sc_ifas[index - 1] = ifa;
1955 ifa->ifa_carp = sc;
1956 carp_hmac_prepare(sc);
1957 carp_sc_state(sc);
1958 CARP_UNLOCK(sc);
1959
1960 sx_xunlock(&carp_sx);
1961
1962 return (0);
1963 }
1964
1965 void
carp_detach(struct ifaddr * ifa,bool keep_cif)1966 carp_detach(struct ifaddr *ifa, bool keep_cif)
1967 {
1968 struct ifnet *ifp = ifa->ifa_ifp;
1969 struct carp_if *cif = ifp->if_carp;
1970 struct carp_softc *sc = ifa->ifa_carp;
1971 int i, index;
1972
1973 KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa));
1974
1975 sx_xlock(&carp_sx);
1976
1977 CARP_LOCK(sc);
1978 /* Shift array. */
1979 index = sc->sc_naddrs + sc->sc_naddrs6;
1980 for (i = 0; i < index; i++)
1981 if (sc->sc_ifas[i] == ifa)
1982 break;
1983 KASSERT(i < index, ("%s: %p no backref", __func__, ifa));
1984 for (; i < index - 1; i++)
1985 sc->sc_ifas[i] = sc->sc_ifas[i+1];
1986 sc->sc_ifas[index - 1] = NULL;
1987
1988 switch (ifa->ifa_addr->sa_family) {
1989 #ifdef INET
1990 case AF_INET:
1991 cif->cif_naddrs--;
1992 sc->sc_naddrs--;
1993 break;
1994 #endif
1995 #ifdef INET6
1996 case AF_INET6:
1997 cif->cif_naddrs6--;
1998 sc->sc_naddrs6--;
1999 break;
2000 #endif
2001 }
2002
2003 carp_ifa_delroute(ifa);
2004 carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family);
2005
2006 ifa->ifa_carp = NULL;
2007 ifa_free(ifa);
2008
2009 carp_hmac_prepare(sc);
2010 carp_sc_state(sc);
2011
2012 if (!keep_cif && sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)
2013 carp_destroy(sc);
2014 else
2015 CARP_UNLOCK(sc);
2016
2017 if (!keep_cif)
2018 CIF_FREE(cif);
2019
2020 sx_xunlock(&carp_sx);
2021 }
2022
2023 static void
carp_set_state(struct carp_softc * sc,int state,const char * reason)2024 carp_set_state(struct carp_softc *sc, int state, const char *reason)
2025 {
2026
2027 CARP_LOCK_ASSERT(sc);
2028
2029 if (sc->sc_state != state) {
2030 const char *carp_states[] = { CARP_STATES };
2031 char subsys[IFNAMSIZ+5];
2032
2033 snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid,
2034 sc->sc_carpdev->if_xname);
2035
2036 CARP_LOG("%s: %s -> %s (%s)\n", subsys,
2037 carp_states[sc->sc_state], carp_states[state], reason);
2038
2039 sc->sc_state = state;
2040
2041 devctl_notify("CARP", subsys, carp_states[state], NULL);
2042 }
2043 }
2044
2045 static void
carp_linkstate(struct ifnet * ifp)2046 carp_linkstate(struct ifnet *ifp)
2047 {
2048 struct carp_softc *sc;
2049
2050 CIF_LOCK(ifp->if_carp);
2051 IFNET_FOREACH_CARP(ifp, sc) {
2052 CARP_LOCK(sc);
2053 carp_sc_state(sc);
2054 CARP_UNLOCK(sc);
2055 }
2056 CIF_UNLOCK(ifp->if_carp);
2057 }
2058
2059 static void
carp_sc_state(struct carp_softc * sc)2060 carp_sc_state(struct carp_softc *sc)
2061 {
2062
2063 CARP_LOCK_ASSERT(sc);
2064
2065 if (sc->sc_carpdev->if_link_state != LINK_STATE_UP ||
2066 !(sc->sc_carpdev->if_flags & IFF_UP) ||
2067 !V_carp_allow) {
2068 callout_stop(&sc->sc_ad_tmo);
2069 #ifdef INET
2070 callout_stop(&sc->sc_md_tmo);
2071 #endif
2072 #ifdef INET6
2073 callout_stop(&sc->sc_md6_tmo);
2074 #endif
2075 carp_set_state(sc, INIT, "hardware interface down");
2076 carp_setrun(sc, 0);
2077 carp_delroute(sc);
2078 if (!sc->sc_suppress)
2079 carp_demote_adj(V_carp_ifdown_adj, "interface down");
2080 sc->sc_suppress = 1;
2081 } else {
2082 carp_set_state(sc, INIT, "hardware interface up");
2083 carp_setrun(sc, 0);
2084 if (sc->sc_suppress)
2085 carp_demote_adj(-V_carp_ifdown_adj, "interface up");
2086 sc->sc_suppress = 0;
2087 }
2088 }
2089
2090 static void
carp_demote_adj(int adj,char * reason)2091 carp_demote_adj(int adj, char *reason)
2092 {
2093 atomic_add_int(&V_carp_demotion, adj);
2094 CARP_LOG("demoted by %d to %d (%s)\n", adj, V_carp_demotion, reason);
2095 taskqueue_enqueue(taskqueue_swi, &carp_sendall_task);
2096 }
2097
2098 static int
carp_allow_sysctl(SYSCTL_HANDLER_ARGS)2099 carp_allow_sysctl(SYSCTL_HANDLER_ARGS)
2100 {
2101 int new, error;
2102 struct carp_softc *sc;
2103
2104 new = V_carp_allow;
2105 error = sysctl_handle_int(oidp, &new, 0, req);
2106 if (error || !req->newptr)
2107 return (error);
2108
2109 if (V_carp_allow != new) {
2110 V_carp_allow = new;
2111
2112 mtx_lock(&carp_mtx);
2113 LIST_FOREACH(sc, &carp_list, sc_next) {
2114 CARP_LOCK(sc);
2115 if (curvnet == sc->sc_carpdev->if_vnet)
2116 carp_sc_state(sc);
2117 CARP_UNLOCK(sc);
2118 }
2119 mtx_unlock(&carp_mtx);
2120 }
2121
2122 return (0);
2123 }
2124
2125 static int
carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)2126 carp_dscp_sysctl(SYSCTL_HANDLER_ARGS)
2127 {
2128 int new, error;
2129
2130 new = V_carp_dscp;
2131 error = sysctl_handle_int(oidp, &new, 0, req);
2132 if (error || !req->newptr)
2133 return (error);
2134
2135 if (new < 0 || new > 63)
2136 return (EINVAL);
2137
2138 V_carp_dscp = new;
2139
2140 return (0);
2141 }
2142
2143 static int
carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)2144 carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS)
2145 {
2146 int new, error;
2147
2148 new = V_carp_demotion;
2149 error = sysctl_handle_int(oidp, &new, 0, req);
2150 if (error || !req->newptr)
2151 return (error);
2152
2153 carp_demote_adj(new, "sysctl");
2154
2155 return (0);
2156 }
2157
2158 #ifdef INET
2159 extern struct domain inetdomain;
2160 static struct protosw in_carp_protosw = {
2161 .pr_type = SOCK_RAW,
2162 .pr_domain = &inetdomain,
2163 .pr_protocol = IPPROTO_CARP,
2164 .pr_flags = PR_ATOMIC|PR_ADDR,
2165 .pr_input = carp_input,
2166 .pr_output = rip_output,
2167 .pr_ctloutput = rip_ctloutput,
2168 .pr_usrreqs = &rip_usrreqs
2169 };
2170 #endif
2171
2172 #ifdef INET6
2173 extern struct domain inet6domain;
2174 static struct protosw in6_carp_protosw = {
2175 .pr_type = SOCK_RAW,
2176 .pr_domain = &inet6domain,
2177 .pr_protocol = IPPROTO_CARP,
2178 .pr_flags = PR_ATOMIC|PR_ADDR,
2179 .pr_input = carp6_input,
2180 .pr_output = rip6_output,
2181 .pr_ctloutput = rip6_ctloutput,
2182 .pr_usrreqs = &rip6_usrreqs
2183 };
2184 #endif
2185
2186 #ifdef VIMAGE
2187 #if defined(__i386__)
2188 /*
2189 * XXX This is a hack to work around an absolute relocation outside
2190 * set_vnet by one (on the stop symbol) for carpstats. Add a dummy variable
2191 * to the end of the file in the hope that the linker will just keep the
2192 * order (as it seems to do at the moment). It is understood to be fragile.
2193 * See PR 230857 for a longer discussion of the problem and the referenced
2194 * review for possible alternate solutions. Each is a hack; we just need
2195 * the least intrusive one for the next release.
2196 */
2197 VNET_DEFINE(char, carp_zzz) = 0xde;
2198 #endif
2199 #endif
2200
2201 static void
carp_mod_cleanup(void)2202 carp_mod_cleanup(void)
2203 {
2204
2205 #ifdef INET
2206 if (proto_reg[CARP_INET] == 0) {
2207 (void)ipproto_unregister(IPPROTO_CARP);
2208 pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW);
2209 proto_reg[CARP_INET] = -1;
2210 }
2211 carp_iamatch_p = NULL;
2212 #endif
2213 #ifdef INET6
2214 if (proto_reg[CARP_INET6] == 0) {
2215 (void)ip6proto_unregister(IPPROTO_CARP);
2216 pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW);
2217 proto_reg[CARP_INET6] = -1;
2218 }
2219 carp_iamatch6_p = NULL;
2220 carp_macmatch6_p = NULL;
2221 #endif
2222 carp_ioctl_p = NULL;
2223 carp_attach_p = NULL;
2224 carp_detach_p = NULL;
2225 carp_get_vhid_p = NULL;
2226 carp_linkstate_p = NULL;
2227 carp_forus_p = NULL;
2228 carp_output_p = NULL;
2229 carp_demote_adj_p = NULL;
2230 carp_master_p = NULL;
2231 mtx_unlock(&carp_mtx);
2232 taskqueue_drain(taskqueue_swi, &carp_sendall_task);
2233 mtx_destroy(&carp_mtx);
2234 sx_destroy(&carp_sx);
2235 }
2236
2237 static int
carp_mod_load(void)2238 carp_mod_load(void)
2239 {
2240 int err;
2241
2242 mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF);
2243 sx_init(&carp_sx, "carp_sx");
2244 LIST_INIT(&carp_list);
2245 carp_get_vhid_p = carp_get_vhid;
2246 carp_forus_p = carp_forus;
2247 carp_output_p = carp_output;
2248 carp_linkstate_p = carp_linkstate;
2249 carp_ioctl_p = carp_ioctl;
2250 carp_attach_p = carp_attach;
2251 carp_detach_p = carp_detach;
2252 carp_demote_adj_p = carp_demote_adj;
2253 carp_master_p = carp_master;
2254 #ifdef INET6
2255 carp_iamatch6_p = carp_iamatch6;
2256 carp_macmatch6_p = carp_macmatch6;
2257 proto_reg[CARP_INET6] = pf_proto_register(PF_INET6,
2258 (struct protosw *)&in6_carp_protosw);
2259 if (proto_reg[CARP_INET6]) {
2260 printf("carp: error %d attaching to PF_INET6\n",
2261 proto_reg[CARP_INET6]);
2262 carp_mod_cleanup();
2263 return (proto_reg[CARP_INET6]);
2264 }
2265 err = ip6proto_register(IPPROTO_CARP);
2266 if (err) {
2267 printf("carp: error %d registering with INET6\n", err);
2268 carp_mod_cleanup();
2269 return (err);
2270 }
2271 #endif
2272 #ifdef INET
2273 carp_iamatch_p = carp_iamatch;
2274 proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw);
2275 if (proto_reg[CARP_INET]) {
2276 printf("carp: error %d attaching to PF_INET\n",
2277 proto_reg[CARP_INET]);
2278 carp_mod_cleanup();
2279 return (proto_reg[CARP_INET]);
2280 }
2281 err = ipproto_register(IPPROTO_CARP);
2282 if (err) {
2283 printf("carp: error %d registering with INET\n", err);
2284 carp_mod_cleanup();
2285 return (err);
2286 }
2287 #endif
2288 return (0);
2289 }
2290
2291 static int
carp_modevent(module_t mod,int type,void * data)2292 carp_modevent(module_t mod, int type, void *data)
2293 {
2294 switch (type) {
2295 case MOD_LOAD:
2296 return carp_mod_load();
2297 /* NOTREACHED */
2298 case MOD_UNLOAD:
2299 mtx_lock(&carp_mtx);
2300 if (LIST_EMPTY(&carp_list))
2301 carp_mod_cleanup();
2302 else {
2303 mtx_unlock(&carp_mtx);
2304 return (EBUSY);
2305 }
2306 break;
2307
2308 default:
2309 return (EINVAL);
2310 }
2311
2312 return (0);
2313 }
2314
2315 static moduledata_t carp_mod = {
2316 "carp",
2317 carp_modevent,
2318 0
2319 };
2320
2321 DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
2322