1 /*
2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
4 *
5 * This code is derived from software contributed to The DragonFly Project
6 * by Jeffrey M. Hsu.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 /*
35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
36 * The Regents of the University of California. All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 *
62 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
63 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $
64 */
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_tcpdebug.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/callout.h>
73 #include <sys/kernel.h>
74 #include <sys/sysctl.h>
75 #include <sys/malloc.h>
76 #include <sys/mpipe.h>
77 #include <sys/mbuf.h>
78 #ifdef INET6
79 #include <sys/domain.h>
80 #endif
81 #include <sys/proc.h>
82 #include <sys/caps.h>
83 #include <sys/socket.h>
84 #include <sys/socketops.h>
85 #include <sys/socketvar.h>
86 #include <sys/protosw.h>
87 #include <sys/random.h>
88 #include <sys/in_cksum.h>
89 #include <sys/ktr.h>
90
91 #include <net/route.h>
92 #include <net/if.h>
93 #include <net/netisr2.h>
94
95 #define _IP_VHL
96 #include <netinet/in.h>
97 #include <netinet/in_systm.h>
98 #include <netinet/ip.h>
99 #include <netinet/ip6.h>
100 #include <netinet/in_pcb.h>
101 #include <netinet6/in6_pcb.h>
102 #include <netinet/in_var.h>
103 #include <netinet/ip_var.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet/ip_icmp.h>
106 #ifdef INET6
107 #include <netinet/icmp6.h>
108 #endif
109 #include <netinet/tcp.h>
110 #include <netinet/tcp_fsm.h>
111 #include <netinet/tcp_seq.h>
112 #include <netinet/tcp_timer.h>
113 #include <netinet/tcp_timer2.h>
114 #include <netinet/tcp_var.h>
115 #include <netinet6/tcp6_var.h>
116 #include <netinet/tcpip.h>
117 #ifdef TCPDEBUG
118 #include <netinet/tcp_debug.h>
119 #endif
120 #include <netinet6/ip6protosw.h>
121
122 #include <sys/md5.h>
123 #include <machine/smp.h>
124
125 #include <sys/msgport2.h>
126 #include <net/netmsg2.h>
127
128 #if !defined(KTR_TCP)
129 #define KTR_TCP KTR_ALL
130 #endif
131 /*
132 KTR_INFO_MASTER(tcp);
133 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0);
134 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0);
135 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0);
136 #define logtcp(name) KTR_LOG(tcp_ ## name)
137 */
138
139 #define TCP_IW_MAXSEGS_DFLT 4
140 #define TCP_IW_CAPSEGS_DFLT 4
141
142 struct tcp_reass_pcpu {
143 int draining;
144 struct netmsg_base drain_nmsg;
145 } __cachealign;
146
147 struct inpcbinfo tcbinfo[MAXCPU];
148 struct tcpcbackq tcpcbackq[MAXCPU];
149 struct tcp_reass_pcpu tcp_reassq[MAXCPU];
150
151 int tcp_mssdflt = TCP_MSS;
152 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
153 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size");
154
155 #ifdef INET6
156 int tcp_v6mssdflt = TCP6_MSS;
157 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW,
158 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6");
159 #endif
160
161 /*
162 * Minimum MSS we accept and use. This prevents DoS attacks where
163 * we are forced to a ridiculous low MSS like 20 and send hundreds
164 * of packets instead of one. The effect scales with the available
165 * bandwidth and quickly saturates the CPU and network interface
166 * with packet generation and sending. Set to zero to disable MINMSS
167 * checking. This setting prevents us from sending too small packets.
168 */
169 int tcp_minmss = TCP_MINMSS;
170 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
171 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size");
172
173 #if 0
174 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
175 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
176 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time");
177 #endif
178
179 int tcp_do_rfc1323 = 1;
180 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
181 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
182
183 static int tcp_tcbhashsize = 0;
184 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
185 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable");
186
187 static int do_tcpdrain = 1;
188 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
189 "Enable tcp_drain routine for extra help when low on mbufs");
190
191 static int icmp_may_rst = 1;
192 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
193 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
194
195 /*
196 * Recommend 20 (6 times in two minutes)
197 *
198 * Lower values may cause the sequence space to cycle too quickly and lose
199 * its signed monotonically-increasing nature within the 2-minute TIMEDWAIT
200 * window.
201 */
202 static int tcp_isn_reseed_interval = 20;
203 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
204 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
205
206 /*
207 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on
208 * by default, but with generous values which should allow maximal
209 * bandwidth. In particular, the slop defaults to 50 (5 packets).
210 *
211 * The reason for doing this is that the limiter is the only mechanism we
212 * have which seems to do a really good job preventing receiver RX rings
213 * on network interfaces from getting blown out. Even though GigE/10GigE
214 * is supposed to flow control it looks like either it doesn't actually
215 * do it or Open Source drivers do not properly enable it.
216 *
217 * People using the limiter to reduce bottlenecks on slower WAN connections
218 * should set the slop to 20 (2 packets).
219 */
220 static int tcp_inflight_enable = 1;
221 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
222 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
223
224 static int tcp_inflight_debug = 0;
225 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
226 &tcp_inflight_debug, 0, "Debug TCP inflight calculations");
227
228 /*
229 * NOTE: tcp_inflight_start is essentially the starting receive window
230 * for a connection. If set too low then fetches over tcp
231 * connections will take noticably longer to ramp-up over
232 * high-latency connections. 6144 is too low for a default,
233 * use something more reasonable.
234 */
235 static int tcp_inflight_start = 33792;
236 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_start, CTLFLAG_RW,
237 &tcp_inflight_start, 0, "Start value for TCP inflight window");
238
239 static int tcp_inflight_min = 6144;
240 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
241 &tcp_inflight_min, 0, "Lower bound for TCP inflight window");
242
243 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
244 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
245 &tcp_inflight_max, 0, "Upper bound for TCP inflight window");
246
247 static int tcp_inflight_stab = 50;
248 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
249 &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)");
250
251 static int tcp_inflight_adjrtt = 2;
252 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW,
253 &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)");
254
255 static int tcp_do_rfc3390 = 1;
256 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW,
257 &tcp_do_rfc3390, 0,
258 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");
259
260 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
261 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW,
262 &tcp_iw_maxsegs, 0, "TCP IW segments max");
263
264 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
265 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW,
266 &tcp_iw_capsegs, 0, "TCP IW segments");
267
268 int tcp_low_rtobase = 1;
269 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW,
270 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)");
271
272 static int tcp_do_ncr = 1;
273 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW,
274 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)");
275
276 int tcp_ncr_linklocal = 0;
277 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_linklocal, CTLFLAG_RW,
278 &tcp_ncr_linklocal, 0,
279 "Enable Non-Congestion Robustness (RFC 4653) on link local network");
280
281 int tcp_ncr_rxtthresh_max = 16;
282 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW,
283 &tcp_ncr_rxtthresh_max, 0,
284 "Non-Congestion Robustness (RFC 4653), DupThresh upper limit");
285
286 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives");
287 static struct malloc_pipe tcptemp_mpipe;
288
289 static void tcp_willblock(void);
290 static void tcp_notify (struct inpcb *, int);
291
292 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign;
293 struct tcp_state_count tcpstate_count[MAXCPU] __cachealign;
294
295 static void tcp_drain_dispatch(netmsg_t nmsg);
296
297 static int
sysctl_tcpstats(SYSCTL_HANDLER_ARGS)298 sysctl_tcpstats(SYSCTL_HANDLER_ARGS)
299 {
300 int cpu, error = 0;
301
302 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
303 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu],
304 sizeof(struct tcp_stats))))
305 break;
306 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu],
307 sizeof(struct tcp_stats))))
308 break;
309 }
310
311 return (error);
312 }
313 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW),
314 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics");
315
316 /*
317 * Target size of TCP PCB hash tables. Must be a power of two.
318 *
319 * Note that this can be overridden by the kernel environment
320 * variable net.inet.tcp.tcbhashsize
321 */
322 #ifndef TCBHASHSIZE
323 #define TCBHASHSIZE 512
324 #endif
325 CTASSERT(powerof2(TCBHASHSIZE));
326
327 /*
328 * This is the actual shape of what we allocate using the zone
329 * allocator. Doing it this way allows us to protect both structures
330 * using the same generation count, and also eliminates the overhead
331 * of allocating tcpcbs separately. By hiding the structure here,
332 * we avoid changing most of the rest of the code (although it needs
333 * to be changed, eventually, for greater efficiency).
334 */
335 #define ALIGNMENT 32
336 #define ALIGNM1 (ALIGNMENT - 1)
337 struct inp_tp {
338 union {
339 struct inpcb inp;
340 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
341 } inp_tp_u;
342 struct tcpcb tcb;
343 struct tcp_callout inp_tp_rexmt;
344 struct tcp_callout inp_tp_persist;
345 struct tcp_callout inp_tp_keep;
346 struct tcp_callout inp_tp_2msl;
347 struct tcp_callout inp_tp_delack;
348 struct netmsg_tcp_timer inp_tp_timermsg;
349 struct netmsg_base inp_tp_sndmore;
350 };
351 #undef ALIGNMENT
352 #undef ALIGNM1
353
354 /*
355 * Tcp initialization
356 */
357 void
tcp_init(void)358 tcp_init(void)
359 {
360 struct inpcbportinfo *portinfo;
361 struct inpcbinfo *ticb;
362 int hashsize = TCBHASHSIZE, portinfo_hsize;
363 int cpu;
364
365 /*
366 * note: tcptemp is used for keepalives, and it is ok for an
367 * allocation to fail so do not specify MPF_INT.
368 */
369 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp),
370 25, -1, 0, NULL, NULL, NULL);
371
372 tcp_delacktime = TCPTV_DELACK;
373 tcp_keepinit = TCPTV_KEEP_INIT;
374 tcp_keepidle = TCPTV_KEEP_IDLE;
375 tcp_keepintvl = TCPTV_KEEPINTVL;
376 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
377 tcp_msl = TCPTV_MSL;
378 tcp_rexmit_min = TCPTV_MIN;
379 if (tcp_rexmit_min < 1) /* if kern.hz is too low */
380 tcp_rexmit_min = 1;
381 tcp_rexmit_slop = TCPTV_CPU_VAR;
382
383 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
384 if (!powerof2(hashsize)) {
385 kprintf("WARNING: TCB hash size not a power of 2\n");
386 hashsize = TCBHASHSIZE; /* safe default */
387 }
388 tcp_tcbhashsize = hashsize;
389
390 portinfo_hsize = 65536 / netisr_ncpus;
391 if (portinfo_hsize > hashsize)
392 portinfo_hsize = hashsize;
393
394 portinfo = kmalloc(sizeof(*portinfo) * netisr_ncpus, M_PCB,
395 M_WAITOK | M_CACHEALIGN);
396
397 for (cpu = 0; cpu < netisr_ncpus; cpu++) {
398 ticb = &tcbinfo[cpu];
399 in_pcbinfo_init(ticb, cpu, FALSE);
400 ticb->hashbase = hashinit(hashsize, M_PCB,
401 &ticb->hashmask);
402 in_pcbportinfo_init(&portinfo[cpu], portinfo_hsize, cpu);
403 in_pcbportinfo_set(ticb, portinfo, netisr_ncpus);
404 ticb->wildcardhashbase = hashinit(hashsize, M_PCB,
405 &ticb->wildcardhashmask);
406 ticb->localgrphashbase = hashinit(hashsize, M_PCB,
407 &ticb->localgrphashmask);
408 ticb->ipi_size = sizeof(struct inp_tp);
409 TAILQ_INIT(&tcpcbackq[cpu].head);
410 }
411
412 tcp_reass_maxseg = nmbclusters / 16;
413 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg);
414
415 #ifdef INET6
416 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
417 #else
418 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
419 #endif
420 if (max_protohdr < TCP_MINPROTOHDR)
421 max_protohdr = TCP_MINPROTOHDR;
422 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
423 panic("tcp_init");
424 #undef TCP_MINPROTOHDR
425
426 /*
427 * Initialize TCP statistics counters for each CPU.
428 */
429 for (cpu = 0; cpu < netisr_ncpus; ++cpu)
430 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats));
431
432 /*
433 * Initialize netmsgs for TCP drain
434 */
435 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
436 netmsg_init(&tcp_reassq[cpu].drain_nmsg, NULL,
437 &netisr_adone_rport, MSGF_PRIORITY, tcp_drain_dispatch);
438 }
439
440 syncache_init();
441 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP);
442 }
443
444 static void
tcp_willblock(void)445 tcp_willblock(void)
446 {
447 struct tcpcb *tp;
448 int cpu = mycpuid;
449
450 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu].head)) != NULL) {
451 KKASSERT(tp->t_flags & TF_ONOUTPUTQ);
452 tp->t_flags &= ~TF_ONOUTPUTQ;
453 TAILQ_REMOVE(&tcpcbackq[cpu].head, tp, t_outputq);
454 tcp_output(tp);
455 }
456 }
457
458 /*
459 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
460 * tcp_template used to store this data in mbufs, but we now recopy it out
461 * of the tcpcb each time to conserve mbufs.
462 */
463 void
tcp_fillheaders(struct tcpcb * tp,void * ip_ptr,void * tcp_ptr,boolean_t tso)464 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso)
465 {
466 struct inpcb *inp = tp->t_inpcb;
467 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
468
469 #ifdef INET6
470 if (INP_ISIPV6(inp)) {
471 struct ip6_hdr *ip6;
472
473 ip6 = (struct ip6_hdr *)ip_ptr;
474 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
475 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
476 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
477 (IPV6_VERSION & IPV6_VERSION_MASK);
478 ip6->ip6_nxt = IPPROTO_TCP;
479 ip6->ip6_plen = sizeof(struct tcphdr);
480 ip6->ip6_src = inp->in6p_laddr;
481 ip6->ip6_dst = inp->in6p_faddr;
482 tcp_hdr->th_sum = 0;
483 } else
484 #endif
485 {
486 struct ip *ip = (struct ip *) ip_ptr;
487 u_int plen;
488
489 ip->ip_vhl = IP_VHL_BORING;
490 ip->ip_tos = 0;
491 ip->ip_len = 0;
492 ip->ip_id = 0;
493 ip->ip_off = 0;
494 ip->ip_ttl = 0;
495 ip->ip_sum = 0;
496 ip->ip_p = IPPROTO_TCP;
497 ip->ip_src = inp->inp_laddr;
498 ip->ip_dst = inp->inp_faddr;
499
500 if (tso)
501 plen = htons(IPPROTO_TCP);
502 else
503 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP);
504 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr,
505 ip->ip_dst.s_addr, plen);
506 }
507
508 tcp_hdr->th_sport = inp->inp_lport;
509 tcp_hdr->th_dport = inp->inp_fport;
510 tcp_hdr->th_seq = 0;
511 tcp_hdr->th_ack = 0;
512 tcp_hdr->th_x2 = 0;
513 tcp_hdr->th_off = 5;
514 tcp_hdr->th_flags = 0;
515 tcp_hdr->th_win = 0;
516 tcp_hdr->th_urp = 0;
517 }
518
519 /*
520 * Create template to be used to send tcp packets on a connection.
521 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
522 * use for this function is in keepalives, which use tcp_respond.
523 */
524 struct tcptemp *
tcp_maketemplate(struct tcpcb * tp)525 tcp_maketemplate(struct tcpcb *tp)
526 {
527 struct tcptemp *tmp;
528
529 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL)
530 return (NULL);
531 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE);
532 return (tmp);
533 }
534
535 void
tcp_freetemplate(struct tcptemp * tmp)536 tcp_freetemplate(struct tcptemp *tmp)
537 {
538 mpipe_free(&tcptemp_mpipe, tmp);
539 }
540
541 /*
542 * Send a single message to the TCP at address specified by
543 * the given TCP/IP header. If m == NULL, then we make a copy
544 * of the tcpiphdr at ti and send directly to the addressed host.
545 * This is used to force keep alive messages out using the TCP
546 * template for a connection. If flags are given then we send
547 * a message back to the TCP which originated the * segment ti,
548 * and discard the mbuf containing it and any other attached mbufs.
549 *
550 * In any case the ack and sequence number of the transmitted
551 * segment are as specified by the parameters.
552 *
553 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
554 */
555 void
tcp_respond(struct tcpcb * tp,void * ipgen,struct tcphdr * th,struct mbuf * m,tcp_seq ack,tcp_seq seq,int flags)556 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
557 tcp_seq ack, tcp_seq seq, int flags)
558 {
559 int tlen;
560 long win = 0;
561 struct route *ro = NULL;
562 struct route sro;
563 struct ip *ip = ipgen;
564 struct tcphdr *nth;
565 int ipflags = 0;
566 struct route_in6 *ro6 = NULL;
567 struct route_in6 sro6;
568 struct ip6_hdr *ip6 = ipgen;
569 struct inpcb *inp = NULL;
570 boolean_t use_tmpro = TRUE;
571 #ifdef INET6
572 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6);
573 #else
574 const boolean_t isipv6 = FALSE;
575 #endif
576
577 if (tp != NULL) {
578 inp = tp->t_inpcb;
579 if (!(flags & TH_RST)) {
580 win = ssb_space(&inp->inp_socket->so_rcv);
581 if (win < 0)
582 win = 0;
583 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
584 win = (long)TCP_MAXWIN << tp->rcv_scale;
585 }
586 /*
587 * Don't use the route cache of a listen socket,
588 * it is not MPSAFE; use temporary route cache.
589 */
590 if (tp->t_state != TCPS_LISTEN) {
591 if (isipv6)
592 ro6 = &inp->in6p_route;
593 else
594 ro = &inp->inp_route;
595 use_tmpro = FALSE;
596 }
597 }
598 if (use_tmpro) {
599 if (isipv6) {
600 ro6 = &sro6;
601 bzero(ro6, sizeof *ro6);
602 } else {
603 ro = &sro;
604 bzero(ro, sizeof *ro);
605 }
606 }
607 if (m == NULL) {
608 m = m_gethdr(M_NOWAIT, MT_HEADER);
609 if (m == NULL)
610 return;
611 tlen = 0;
612 m->m_data += max_linkhdr;
613 if (isipv6) {
614 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr));
615 ip6 = mtod(m, struct ip6_hdr *);
616 nth = (struct tcphdr *)(ip6 + 1);
617 } else {
618 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
619 ip = mtod(m, struct ip *);
620 nth = (struct tcphdr *)(ip + 1);
621 }
622 bcopy(th, nth, sizeof(struct tcphdr));
623 flags = TH_ACK;
624 } else {
625 m_freem(m->m_next);
626 m->m_next = NULL;
627 m->m_data = (caddr_t)ipgen;
628 /* m_len is set later */
629 tlen = 0;
630 #define xchg(a, b, type) { type t; t = a; a = b; b = t; }
631 if (isipv6) {
632 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
633 nth = (struct tcphdr *)(ip6 + 1);
634 } else {
635 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
636 nth = (struct tcphdr *)(ip + 1);
637 }
638 if (th != nth) {
639 /*
640 * this is usually a case when an extension header
641 * exists between the IPv6 header and the
642 * TCP header.
643 */
644 nth->th_sport = th->th_sport;
645 nth->th_dport = th->th_dport;
646 }
647 xchg(nth->th_dport, nth->th_sport, n_short);
648 #undef xchg
649 }
650 if (isipv6) {
651 ip6->ip6_flow = 0;
652 ip6->ip6_vfc = IPV6_VERSION;
653 ip6->ip6_nxt = IPPROTO_TCP;
654 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen));
655 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
656 } else {
657 tlen += sizeof(struct tcpiphdr);
658 ip->ip_len = htons(tlen);
659 ip->ip_ttl = ip_defttl;
660 }
661 m->m_len = tlen;
662 m->m_pkthdr.len = tlen;
663 m->m_pkthdr.rcvif = NULL;
664 nth->th_seq = htonl(seq);
665 nth->th_ack = htonl(ack);
666 nth->th_x2 = 0;
667 nth->th_off = sizeof(struct tcphdr) >> 2;
668 nth->th_flags = flags;
669 if (tp != NULL)
670 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
671 else
672 nth->th_win = htons((u_short)win);
673 nth->th_urp = 0;
674 if (isipv6) {
675 nth->th_sum = 0;
676 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
677 sizeof(struct ip6_hdr),
678 tlen - sizeof(struct ip6_hdr));
679 ip6->ip6_hlim = in6_selecthlim(inp,
680 (ro6 && ro6->ro_rt) ? ro6->ro_rt->rt_ifp : NULL);
681 } else {
682 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
683 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
684 m->m_pkthdr.csum_flags = CSUM_TCP;
685 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
686 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr);
687 }
688 #ifdef TCPDEBUG
689 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
690 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
691 #endif
692 if (isipv6) {
693 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, inp);
694 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) {
695 RTFREE(ro6->ro_rt);
696 ro6->ro_rt = NULL;
697 }
698 } else {
699 if (inp != NULL && (inp->inp_flags & INP_HASH))
700 m_sethash(m, inp->inp_hashval);
701 ipflags |= IP_DEBUGROUTE;
702 ip_output(m, NULL, ro, ipflags, NULL, inp);
703 if ((ro == &sro) && (ro->ro_rt != NULL)) {
704 RTFREE(ro->ro_rt);
705 ro->ro_rt = NULL;
706 }
707 }
708 }
709
710 /*
711 * Create a new TCP control block, making an
712 * empty reassembly queue and hooking it to the argument
713 * protocol control block. The `inp' parameter must have
714 * come from the zone allocator set up in tcp_init().
715 */
716 void
tcp_newtcpcb(struct inpcb * inp)717 tcp_newtcpcb(struct inpcb *inp)
718 {
719 struct inp_tp *it;
720 struct tcpcb *tp;
721 #ifdef INET6
722 boolean_t isipv6 = INP_ISIPV6(inp);
723 #else
724 const boolean_t isipv6 = FALSE;
725 #endif
726
727 it = (struct inp_tp *)inp;
728 tp = &it->tcb;
729 bzero(tp, sizeof(struct tcpcb));
730 TAILQ_INIT(&tp->t_segq);
731 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt;
732 tp->t_rxtthresh = tcprexmtthresh;
733
734 /* Set up our timeouts. */
735 tp->tt_rexmt = &it->inp_tp_rexmt;
736 tp->tt_persist = &it->inp_tp_persist;
737 tp->tt_keep = &it->inp_tp_keep;
738 tp->tt_2msl = &it->inp_tp_2msl;
739 tp->tt_delack = &it->inp_tp_delack;
740 tcp_inittimers(tp);
741
742 /*
743 * Zero out timer message. We don't create it here,
744 * since the current CPU may not be the owner of this
745 * inpcb.
746 */
747 tp->tt_msg = &it->inp_tp_timermsg;
748 bzero(tp->tt_msg, sizeof(*tp->tt_msg));
749
750 tp->t_keepinit = tcp_keepinit;
751 tp->t_keepidle = tcp_keepidle;
752 tp->t_keepintvl = tcp_keepintvl;
753 tp->t_keepcnt = tcp_keepcnt;
754 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt;
755
756 if (tcp_do_ncr)
757 tp->t_flags |= TF_NCR;
758 if (tcp_do_rfc1323)
759 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP);
760
761 tp->t_inpcb = inp; /* XXX */
762 TCP_STATE_INIT(tp);
763 /*
764 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
765 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
766 * reasonable initial retransmit time.
767 */
768 tp->t_srtt = TCPTV_SRTTBASE;
769 tp->t_rttvar =
770 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
771 tp->t_rttmin = tcp_rexmit_min;
772 tp->t_rxtcur = TCPTV_RTOBASE;
773 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
774 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
775 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
776 tp->snd_last = ticks;
777 tp->t_rcvtime = ticks;
778 /*
779 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
780 * because the socket may be bound to an IPv6 wildcard address,
781 * which may match an IPv4-mapped IPv6 address.
782 */
783 inp->inp_ip_ttl = ip_defttl;
784 inp->inp_ppcb = tp;
785 tcp_sack_tcpcb_init(tp);
786
787 tp->tt_sndmore = &it->inp_tp_sndmore;
788 tcp_output_init(tp);
789 }
790
791 /*
792 * Drop a TCP connection, reporting the specified error.
793 * If connection is synchronized, then send a RST to peer.
794 */
795 struct tcpcb *
tcp_drop(struct tcpcb * tp,int error)796 tcp_drop(struct tcpcb *tp, int error)
797 {
798 struct socket *so = tp->t_inpcb->inp_socket;
799
800 if (TCPS_HAVERCVDSYN(tp->t_state)) {
801 TCP_STATE_CHANGE(tp, TCPS_CLOSED);
802 tcp_output(tp);
803 tcpstat.tcps_drops++;
804 } else
805 tcpstat.tcps_conndrops++;
806 if (error == ETIMEDOUT && tp->t_softerror)
807 error = tp->t_softerror;
808 so->so_error = error;
809 return (tcp_close(tp));
810 }
811
812 struct netmsg_listen_detach {
813 struct netmsg_base base;
814 struct tcpcb *nm_tp;
815 struct tcpcb *nm_tp_inh;
816 };
817
818 static void
tcp_listen_detach_handler(netmsg_t msg)819 tcp_listen_detach_handler(netmsg_t msg)
820 {
821 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg;
822 struct tcpcb *tp = nmsg->nm_tp;
823 int cpu = mycpuid, nextcpu;
824
825 if (tp->t_flags & TF_LISTEN) {
826 syncache_destroy(tp, nmsg->nm_tp_inh);
827 tcp_pcbport_merge_oncpu(tp);
828 }
829
830 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]);
831
832 nextcpu = cpu + 1;
833 if (nextcpu < netisr_ncpus)
834 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg);
835 else
836 lwkt_replymsg(&nmsg->base.lmsg, 0);
837 }
838
839 /*
840 * Close a TCP control block:
841 * discard all space held by the tcp
842 * discard internet protocol block
843 * wake up any sleepers
844 */
845 struct tcpcb *
tcp_close(struct tcpcb * tp)846 tcp_close(struct tcpcb *tp)
847 {
848 struct tseg_qent *q;
849 struct inpcb *inp = tp->t_inpcb;
850 struct inpcb *inp_inh = NULL;
851 struct tcpcb *tp_inh = NULL;
852 struct socket *so = inp->inp_socket;
853 struct rtentry *rt;
854 boolean_t dosavessthresh;
855 #ifdef INET6
856 boolean_t isipv6 = INP_ISIPV6(inp);
857 #else
858 const boolean_t isipv6 = FALSE;
859 #endif
860
861 if (tp->t_flags & TF_LISTEN) {
862 /*
863 * Pending socket/syncache inheritance
864 *
865 * If this is a listen(2) socket, find another listen(2)
866 * socket in the same local group, which could inherit
867 * the syncache and sockets pending on the completion
868 * and incompletion queues.
869 *
870 * NOTE:
871 * Currently the inheritance could only happen on the
872 * listen(2) sockets w/ SO_REUSEPORT set.
873 */
874 ASSERT_NETISR0;
875 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp);
876 if (inp_inh != NULL)
877 tp_inh = intotcpcb(inp_inh);
878 }
879
880 /*
881 * INP_WILDCARD indicates that listen(2) has been called on
882 * this socket. This implies:
883 * - A wildcard inp's hash is replicated for each protocol thread.
884 * - Syncache for this inp grows independently in each protocol
885 * thread.
886 * - There is more than one cpu
887 *
888 * We have to chain a message to the rest of the protocol threads
889 * to cleanup the wildcard hash and the syncache. The cleanup
890 * in the current protocol thread is defered till the end of this
891 * function (syncache_destroy and in_pcbdetach).
892 *
893 * NOTE:
894 * After cleanup the inp's hash and syncache entries, this inp will
895 * no longer be available to the rest of the protocol threads, so we
896 * are safe to whack the inp in the following code.
897 */
898 if ((inp->inp_flags & INP_WILDCARD) && netisr_ncpus > 1) {
899 struct netmsg_listen_detach nmsg;
900
901 KKASSERT(so->so_port == netisr_cpuport(0));
902 ASSERT_NETISR0;
903 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]);
904
905 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport,
906 MSGF_PRIORITY, tcp_listen_detach_handler);
907 nmsg.nm_tp = tp;
908 nmsg.nm_tp_inh = tp_inh;
909 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0);
910 }
911
912 TCP_STATE_TERM(tp);
913
914 /*
915 * Make sure that all of our timers are stopped before we
916 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL),
917 * timers are never used. If timer message is never created
918 * (tp->tt_msg->tt_tcb == NULL), timers are never used too.
919 */
920 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) {
921 tcp_callout_terminate(tp, tp->tt_rexmt);
922 tcp_callout_terminate(tp, tp->tt_persist);
923 tcp_callout_terminate(tp, tp->tt_keep);
924 tcp_callout_terminate(tp, tp->tt_2msl);
925 tcp_callout_terminate(tp, tp->tt_delack);
926 }
927
928 if (tp->t_flags & TF_ONOUTPUTQ) {
929 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid);
930 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu].head, tp, t_outputq);
931 tp->t_flags &= ~TF_ONOUTPUTQ;
932 }
933
934 /*
935 * If we got enough samples through the srtt filter,
936 * save the rtt and rttvar in the routing entry.
937 * 'Enough' is arbitrarily defined as the 16 samples.
938 * 16 samples is enough for the srtt filter to converge
939 * to within 5% of the correct value; fewer samples and
940 * we could save a very bogus rtt.
941 *
942 * Don't update the default route's characteristics and don't
943 * update anything that the user "locked".
944 */
945 if (tp->t_rttupdated >= 16) {
946 u_long i = 0;
947
948 if (isipv6) {
949 struct sockaddr_in6 *sin6;
950
951 if ((rt = inp->in6p_route.ro_rt) == NULL)
952 goto no_valid_rt;
953 sin6 = (struct sockaddr_in6 *)rt_key(rt);
954 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
955 goto no_valid_rt;
956 } else
957 if ((rt = inp->inp_route.ro_rt) == NULL ||
958 ((struct sockaddr_in *)rt_key(rt))->
959 sin_addr.s_addr == INADDR_ANY)
960 goto no_valid_rt;
961
962 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) {
963 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
964 if (rt->rt_rmx.rmx_rtt && i)
965 /*
966 * filter this update to half the old & half
967 * the new values, converting scale.
968 * See route.h and tcp_var.h for a
969 * description of the scaling constants.
970 */
971 rt->rt_rmx.rmx_rtt =
972 (rt->rt_rmx.rmx_rtt + i) / 2;
973 else
974 rt->rt_rmx.rmx_rtt = i;
975 tcpstat.tcps_cachedrtt++;
976 }
977 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) {
978 i = tp->t_rttvar *
979 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
980 if (rt->rt_rmx.rmx_rttvar && i)
981 rt->rt_rmx.rmx_rttvar =
982 (rt->rt_rmx.rmx_rttvar + i) / 2;
983 else
984 rt->rt_rmx.rmx_rttvar = i;
985 tcpstat.tcps_cachedrttvar++;
986 }
987 /*
988 * The old comment here said:
989 * update the pipelimit (ssthresh) if it has been updated
990 * already or if a pipesize was specified & the threshhold
991 * got below half the pipesize. I.e., wait for bad news
992 * before we start updating, then update on both good
993 * and bad news.
994 *
995 * But we want to save the ssthresh even if no pipesize is
996 * specified explicitly in the route, because such
997 * connections still have an implicit pipesize specified
998 * by the global tcp_sendspace. In the absence of a reliable
999 * way to calculate the pipesize, it will have to do.
1000 */
1001 i = tp->snd_ssthresh;
1002 if (rt->rt_rmx.rmx_sendpipe != 0)
1003 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2);
1004 else
1005 dosavessthresh = (i < so->so_snd.ssb_hiwat/2);
1006 if (dosavessthresh ||
1007 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) &&
1008 (rt->rt_rmx.rmx_ssthresh != 0))) {
1009 /*
1010 * convert the limit from user data bytes to
1011 * packets then to packet data bytes.
1012 */
1013 i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
1014 if (i < 2)
1015 i = 2;
1016 i *= tp->t_maxseg +
1017 (isipv6 ?
1018 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1019 sizeof(struct tcpiphdr));
1020 if (rt->rt_rmx.rmx_ssthresh)
1021 rt->rt_rmx.rmx_ssthresh =
1022 (rt->rt_rmx.rmx_ssthresh + i) / 2;
1023 else
1024 rt->rt_rmx.rmx_ssthresh = i;
1025 tcpstat.tcps_cachedssthresh++;
1026 }
1027 }
1028
1029 no_valid_rt:
1030 /* free the reassembly queue, if any */
1031 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) {
1032 TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
1033 m_freem(q->tqe_m);
1034 kfree(q, M_TSEGQ);
1035 atomic_add_int(&tcp_reass_qsize, -1);
1036 }
1037 /* throw away SACK blocks in scoreboard*/
1038 if (TCP_DO_SACK(tp))
1039 tcp_sack_destroy(&tp->scb);
1040
1041 inp->inp_ppcb = NULL;
1042 soisdisconnected(so);
1043 /* note: pcb detached later on */
1044
1045 tcp_destroy_timermsg(tp);
1046 tcp_output_cancel(tp);
1047
1048 if (tp->t_flags & TF_LISTEN) {
1049 syncache_destroy(tp, tp_inh);
1050 tcp_pcbport_merge_oncpu(tp);
1051 tcp_pcbport_destroy(tp);
1052 if (inp_inh != NULL && inp_inh->inp_socket != NULL) {
1053 /*
1054 * Pending sockets inheritance only needs
1055 * to be done once in the current thread,
1056 * i.e. netisr0.
1057 */
1058 soinherit(so, inp_inh->inp_socket);
1059 }
1060 }
1061 KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache is not destroyed"));
1062
1063 so_async_rcvd_drop(so);
1064 /* Drop the reference for the asynchronized pru_rcvd */
1065 sofree(so);
1066
1067 /*
1068 * NOTE:
1069 * - Remove self from listen tcpcb per-cpu port cache _before_
1070 * pcbdetach.
1071 * - pcbdetach removes any wildcard hash entry on the current CPU.
1072 */
1073 tcp_pcbport_remove(inp);
1074 #ifdef INET6
1075 if (isipv6)
1076 in6_pcbdetach(inp);
1077 else
1078 #endif
1079 in_pcbdetach(inp);
1080
1081 tcpstat.tcps_closed++;
1082 return (NULL);
1083 }
1084
1085 /*
1086 * Walk the tcpbs, if existing, and flush the reassembly queue,
1087 * if there is one...
1088 */
1089 static void
tcp_drain_oncpu(struct inpcbinfo * pcbinfo)1090 tcp_drain_oncpu(struct inpcbinfo *pcbinfo)
1091 {
1092 struct inpcbhead *head = &pcbinfo->pcblisthead;
1093 struct inpcb *inpb;
1094
1095 /*
1096 * Since we run in netisr, it is MP safe, even if
1097 * we block during the inpcb list iteration, i.e.
1098 * we don't need to use inpcb marker here.
1099 */
1100 ASSERT_NETISR_NCPUS(pcbinfo->cpu);
1101
1102 LIST_FOREACH(inpb, head, inp_list) {
1103 struct tcpcb *tcpb;
1104 struct tseg_qent *te;
1105
1106 if (inpb->inp_flags & INP_PLACEMARKER)
1107 continue;
1108
1109 tcpb = intotcpcb(inpb);
1110 KASSERT(tcpb != NULL, ("tcp_drain_oncpu: tcpb is NULL"));
1111
1112 if ((te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) {
1113 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q);
1114 if (te->tqe_th->th_flags & TH_FIN)
1115 tcpb->t_flags &= ~TF_QUEDFIN;
1116 m_freem(te->tqe_m);
1117 kfree(te, M_TSEGQ);
1118 atomic_add_int(&tcp_reass_qsize, -1);
1119 /* retry */
1120 }
1121 }
1122 }
1123
1124 static void
tcp_drain_dispatch(netmsg_t nmsg)1125 tcp_drain_dispatch(netmsg_t nmsg)
1126 {
1127 crit_enter();
1128 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */
1129 crit_exit();
1130
1131 tcp_drain_oncpu(&tcbinfo[mycpuid]);
1132 tcp_reassq[mycpuid].draining = 0;
1133 }
1134
1135 static void
tcp_drain_ipi(void * arg __unused)1136 tcp_drain_ipi(void *arg __unused)
1137 {
1138 int cpu = mycpuid;
1139 struct lwkt_msg *msg = &tcp_reassq[cpu].drain_nmsg.lmsg;
1140
1141 crit_enter();
1142 if (msg->ms_flags & MSGF_DONE)
1143 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg);
1144 crit_exit();
1145 }
1146
1147 void
tcp_drain(void)1148 tcp_drain(void)
1149 {
1150 cpumask_t mask;
1151 int cpu;
1152
1153 if (!do_tcpdrain)
1154 return;
1155
1156 if (tcp_reass_qsize == 0)
1157 return;
1158
1159 CPUMASK_ASSBMASK(mask, netisr_ncpus);
1160 CPUMASK_ANDMASK(mask, smp_active_mask);
1161
1162 cpu = mycpuid;
1163 if (IN_NETISR_NCPUS(cpu)) {
1164 tcp_drain_oncpu(&tcbinfo[cpu]);
1165 CPUMASK_NANDBIT(mask, cpu);
1166 }
1167
1168 if (tcp_reass_qsize < netisr_ncpus) {
1169 /* Does not worth the trouble. */
1170 return;
1171 }
1172
1173 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
1174 if (!CPUMASK_TESTBIT(mask, cpu))
1175 continue;
1176
1177 if (tcp_reassq[cpu].draining) {
1178 /* Draining; skip this cpu. */
1179 CPUMASK_NANDBIT(mask, cpu);
1180 continue;
1181 }
1182 tcp_reassq[cpu].draining = 1;
1183 }
1184
1185 if (CPUMASK_TESTNZERO(mask))
1186 lwkt_send_ipiq_mask(mask, tcp_drain_ipi, NULL);
1187 }
1188
1189 /*
1190 * Notify a tcp user of an asynchronous error;
1191 * store error as soft error, but wake up user
1192 * (for now, won't do anything until can select for soft error).
1193 *
1194 * Do not wake up user since there currently is no mechanism for
1195 * reporting soft errors (yet - a kqueue filter may be added).
1196 */
1197 static void
tcp_notify(struct inpcb * inp,int error)1198 tcp_notify(struct inpcb *inp, int error)
1199 {
1200 struct tcpcb *tp = intotcpcb(inp);
1201
1202 /*
1203 * Ignore some errors if we are hooked up.
1204 * If connection hasn't completed, has retransmitted several times,
1205 * and receives a second error, give up now. This is better
1206 * than waiting a long time to establish a connection that
1207 * can never complete.
1208 */
1209 if (tp->t_state == TCPS_ESTABLISHED &&
1210 (error == EHOSTUNREACH || error == ENETUNREACH ||
1211 error == EHOSTDOWN)) {
1212 return;
1213 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1214 tp->t_softerror)
1215 tcp_drop(tp, error);
1216 else
1217 tp->t_softerror = error;
1218 #if 0
1219 wakeup(&so->so_timeo);
1220 sorwakeup(so);
1221 sowwakeup(so);
1222 #endif
1223 }
1224
1225 static int
tcp_pcblist(SYSCTL_HANDLER_ARGS)1226 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1227 {
1228 int error, i, n;
1229 struct inpcb *marker;
1230 struct inpcb *inp;
1231 int origcpu, ccpu;
1232
1233 error = 0;
1234 n = 0;
1235
1236 /*
1237 * The process of preparing the TCB list is too time-consuming and
1238 * resource-intensive to repeat twice on every request.
1239 */
1240 if (req->oldptr == NULL) {
1241 for (ccpu = 0; ccpu < netisr_ncpus; ++ccpu)
1242 n += tcbinfo[ccpu].ipi_count;
1243 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb);
1244 return (0);
1245 }
1246
1247 if (req->newptr != NULL)
1248 return (EPERM);
1249
1250 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO);
1251 marker->inp_flags |= INP_PLACEMARKER;
1252
1253 /*
1254 * OK, now we're committed to doing something. Run the inpcb list
1255 * for each cpu in the system and construct the output. Use a
1256 * list placemarker to deal with list changes occuring during
1257 * copyout blockages (but otherwise depend on being on the correct
1258 * cpu to avoid races).
1259 */
1260 origcpu = mycpu->gd_cpuid;
1261 for (ccpu = 0; ccpu < netisr_ncpus && error == 0; ++ccpu) {
1262 caddr_t inp_ppcb;
1263 struct xtcpcb xt;
1264
1265 lwkt_migratecpu(ccpu);
1266
1267 n = tcbinfo[ccpu].ipi_count;
1268
1269 LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list);
1270 i = 0;
1271 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) {
1272 /*
1273 * process a snapshot of pcbs, ignoring placemarkers
1274 * and using our own to allow SYSCTL_OUT to block.
1275 */
1276 LIST_REMOVE(marker, inp_list);
1277 LIST_INSERT_AFTER(inp, marker, inp_list);
1278
1279 if (inp->inp_flags & INP_PLACEMARKER)
1280 continue;
1281 if (prison_xinpcb(req->td, inp))
1282 continue;
1283
1284 xt.xt_len = sizeof xt;
1285 bcopy(inp, &xt.xt_inp, sizeof *inp);
1286 inp_ppcb = inp->inp_ppcb;
1287 if (inp_ppcb != NULL)
1288 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1289 else
1290 bzero(&xt.xt_tp, sizeof xt.xt_tp);
1291 if (inp->inp_socket)
1292 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1293 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0)
1294 break;
1295 ++i;
1296 }
1297 LIST_REMOVE(marker, inp_list);
1298 if (error == 0 && i < n) {
1299 bzero(&xt, sizeof xt);
1300 xt.xt_len = sizeof xt;
1301 while (i < n) {
1302 error = SYSCTL_OUT(req, &xt, sizeof xt);
1303 if (error)
1304 break;
1305 ++i;
1306 }
1307 }
1308 }
1309
1310 /*
1311 * Make sure we are on the same cpu we were on originally, since
1312 * higher level callers expect this. Also don't pollute caches with
1313 * migrated userland data by (eventually) returning to userland
1314 * on a different cpu.
1315 */
1316 lwkt_migratecpu(origcpu);
1317 kfree(marker, M_TEMP);
1318 return (error);
1319 }
1320
1321 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1322 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1323
1324 static int
tcp_getcred(SYSCTL_HANDLER_ARGS)1325 tcp_getcred(SYSCTL_HANDLER_ARGS)
1326 {
1327 struct sockaddr_in addrs[2];
1328 struct ucred cred0, *cred = NULL;
1329 struct inpcb *inp;
1330 int cpu, origcpu, error;
1331
1332 error = caps_priv_check_td(req->td, SYSCAP_RESTRICTEDROOT);
1333 if (error != 0)
1334 return (error);
1335 error = SYSCTL_IN(req, addrs, sizeof addrs);
1336 if (error != 0)
1337 return (error);
1338
1339 origcpu = mycpuid;
1340 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port,
1341 addrs[0].sin_addr.s_addr, addrs[0].sin_port);
1342
1343 lwkt_migratecpu(cpu);
1344
1345 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr,
1346 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1347 if (inp == NULL || inp->inp_socket == NULL) {
1348 error = ENOENT;
1349 } else if (inp->inp_socket->so_cred != NULL) {
1350 cred0 = *(inp->inp_socket->so_cred);
1351 cred = &cred0;
1352 }
1353
1354 lwkt_migratecpu(origcpu);
1355
1356 if (error)
1357 return (error);
1358
1359 return SYSCTL_OUT(req, cred, sizeof(struct ucred));
1360 }
1361
1362 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1363 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection");
1364
1365 #ifdef INET6
1366 static int
tcp6_getcred(SYSCTL_HANDLER_ARGS)1367 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1368 {
1369 struct sockaddr_in6 addrs[2];
1370 struct inpcb *inp;
1371 int error;
1372
1373 error = caps_priv_check_td(req->td, SYSCAP_RESTRICTEDROOT);
1374 if (error != 0)
1375 return (error);
1376 error = SYSCTL_IN(req, addrs, sizeof addrs);
1377 if (error != 0)
1378 return (error);
1379 crit_enter();
1380 inp = in6_pcblookup_hash(&tcbinfo[0],
1381 &addrs[1].sin6_addr, addrs[1].sin6_port,
1382 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL);
1383 if (inp == NULL || inp->inp_socket == NULL) {
1384 error = ENOENT;
1385 goto out;
1386 }
1387 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred));
1388 out:
1389 crit_exit();
1390 return (error);
1391 }
1392
1393 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW),
1394 0, 0,
1395 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection");
1396 #endif
1397
1398 struct netmsg_tcp_notify {
1399 struct netmsg_base base;
1400 inp_notify_t nm_notify;
1401 struct in_addr nm_faddr;
1402 int nm_arg;
1403 };
1404
1405 static void
tcp_notifyall_oncpu(netmsg_t msg)1406 tcp_notifyall_oncpu(netmsg_t msg)
1407 {
1408 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg;
1409 int nextcpu;
1410
1411 ASSERT_NETISR_NCPUS(mycpuid);
1412
1413 in_pcbnotifyall(&tcbinfo[mycpuid], nm->nm_faddr,
1414 nm->nm_arg, nm->nm_notify);
1415
1416 nextcpu = mycpuid + 1;
1417 if (nextcpu < netisr_ncpus)
1418 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg);
1419 else
1420 lwkt_replymsg(&nm->base.lmsg, 0);
1421 }
1422
1423 inp_notify_t
tcp_get_inpnotify(int cmd,const struct sockaddr * sa,int * arg,struct ip ** ip0,int * cpuid)1424 tcp_get_inpnotify(int cmd, const struct sockaddr *sa,
1425 int *arg, struct ip **ip0, int *cpuid)
1426 {
1427 struct ip *ip = *ip0;
1428 struct in_addr faddr;
1429 inp_notify_t notify = tcp_notify;
1430
1431 faddr = ((const struct sockaddr_in *)sa)->sin_addr;
1432 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1433 return NULL;
1434
1435 *arg = inetctlerrmap[cmd];
1436 if (cmd == PRC_QUENCH) {
1437 notify = tcp_quench;
1438 } else if (icmp_may_rst &&
1439 (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1440 cmd == PRC_UNREACH_PORT ||
1441 cmd == PRC_TIMXCEED_INTRANS) &&
1442 ip != NULL) {
1443 notify = tcp_drop_syn_sent;
1444 } else if (cmd == PRC_MSGSIZE) {
1445 const struct icmp *icmp = (const struct icmp *)
1446 ((caddr_t)ip - offsetof(struct icmp, icmp_ip));
1447
1448 *arg = ntohs(icmp->icmp_nextmtu);
1449 notify = tcp_mtudisc;
1450 } else if (PRC_IS_REDIRECT(cmd)) {
1451 ip = NULL;
1452 notify = in_rtchange;
1453 } else if (cmd == PRC_HOSTDEAD) {
1454 ip = NULL;
1455 } else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
1456 return NULL;
1457 }
1458
1459 if (cpuid != NULL) {
1460 if (ip == NULL) {
1461 /* Go through all effective netisr CPUs. */
1462 *cpuid = netisr_ncpus;
1463 } else {
1464 const struct tcphdr *th;
1465
1466 th = (const struct tcphdr *)
1467 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2));
1468 *cpuid = tcp_addrcpu(faddr.s_addr, th->th_dport,
1469 ip->ip_src.s_addr, th->th_sport);
1470 }
1471 }
1472
1473 *ip0 = ip;
1474 return notify;
1475 }
1476
1477 void
tcp_ctlinput(netmsg_t msg)1478 tcp_ctlinput(netmsg_t msg)
1479 {
1480 int cmd = msg->ctlinput.nm_cmd;
1481 struct sockaddr *sa = msg->ctlinput.nm_arg;
1482 struct ip *ip = msg->ctlinput.nm_extra;
1483 struct in_addr faddr;
1484 inp_notify_t notify;
1485 int arg, cpuid;
1486
1487 ASSERT_NETISR_NCPUS(mycpuid);
1488
1489 notify = tcp_get_inpnotify(cmd, sa, &arg, &ip, &cpuid);
1490 if (notify == NULL)
1491 goto done;
1492
1493 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1494 if (ip != NULL) {
1495 const struct tcphdr *th;
1496 struct inpcb *inp;
1497
1498 if (cpuid != mycpuid)
1499 goto done;
1500
1501 th = (const struct tcphdr *)
1502 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2));
1503 inp = in_pcblookup_hash(&tcbinfo[mycpuid], faddr, th->th_dport,
1504 ip->ip_src, th->th_sport, 0, NULL);
1505 if (inp != NULL && inp->inp_socket != NULL) {
1506 tcp_seq icmpseq = htonl(th->th_seq);
1507 struct tcpcb *tp = intotcpcb(inp);
1508
1509 if (SEQ_GEQ(icmpseq, tp->snd_una) &&
1510 SEQ_LT(icmpseq, tp->snd_max))
1511 notify(inp, arg);
1512 } else {
1513 struct in_conninfo inc;
1514
1515 inc.inc_fport = th->th_dport;
1516 inc.inc_lport = th->th_sport;
1517 inc.inc_faddr = faddr;
1518 inc.inc_laddr = ip->ip_src;
1519 #ifdef INET6
1520 inc.inc_isipv6 = 0;
1521 #endif
1522 syncache_unreach(&inc, th);
1523 }
1524 } else if (msg->ctlinput.nm_direct) {
1525 if (cpuid != netisr_ncpus && cpuid != mycpuid)
1526 goto done;
1527
1528 in_pcbnotifyall(&tcbinfo[mycpuid], faddr, arg, notify);
1529 } else {
1530 struct netmsg_tcp_notify *nm;
1531
1532 ASSERT_NETISR0;
1533 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT);
1534 netmsg_init(&nm->base, NULL, &netisr_afree_rport,
1535 0, tcp_notifyall_oncpu);
1536 nm->nm_faddr = faddr;
1537 nm->nm_arg = arg;
1538 nm->nm_notify = notify;
1539
1540 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg);
1541 }
1542 done:
1543 lwkt_replymsg(&msg->lmsg, 0);
1544 }
1545
1546 #ifdef INET6
1547
1548 void
tcp6_ctlinput(netmsg_t msg)1549 tcp6_ctlinput(netmsg_t msg)
1550 {
1551 int cmd = msg->ctlinput.nm_cmd;
1552 struct sockaddr *sa = msg->ctlinput.nm_arg;
1553 void *d = msg->ctlinput.nm_extra;
1554 struct tcphdr th;
1555 inp_notify_t notify = tcp_notify;
1556 struct ip6_hdr *ip6;
1557 struct mbuf *m;
1558 struct ip6ctlparam *ip6cp = NULL;
1559 const struct sockaddr_in6 *sa6_src = NULL;
1560 int off;
1561 struct tcp_portonly {
1562 u_int16_t th_sport;
1563 u_int16_t th_dport;
1564 } *thp;
1565 int arg;
1566
1567 if (sa->sa_family != AF_INET6 ||
1568 sa->sa_len != sizeof(struct sockaddr_in6)) {
1569 goto out;
1570 }
1571
1572 arg = 0;
1573 if (cmd == PRC_QUENCH)
1574 notify = tcp_quench;
1575 else if (cmd == PRC_MSGSIZE) {
1576 /*
1577 * The MTU can be passed via an icmp6 packet or directly
1578 * via ip6c_cmdarg.
1579 */
1580 struct ip6ctlparam *ip6cp = d;
1581
1582 if (ip6cp->ip6c_icmp6) {
1583 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1584 arg = ntohl(icmp6->icmp6_mtu);
1585 } else if (ip6cp->ip6c_cmdarg) {
1586 arg = *(uint32_t *)ip6cp->ip6c_cmdarg;
1587 } else {
1588 goto out;
1589 }
1590 notify = tcp_mtudisc;
1591 } else if (!PRC_IS_REDIRECT(cmd) &&
1592 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) {
1593 goto out;
1594 }
1595
1596 /*
1597 * If the parameter is from icmp6, decode it. Note that in the
1598 * mtu shortcut case, the rest of the ip6ctlparam content is
1599 * 0 or NULL.
1600 */
1601 if (d != NULL) {
1602 ip6cp = (struct ip6ctlparam *)d;
1603 m = ip6cp->ip6c_m;
1604 ip6 = ip6cp->ip6c_ip6;
1605 off = ip6cp->ip6c_off;
1606 sa6_src = ip6cp->ip6c_src;
1607 } else {
1608 m = NULL;
1609 ip6 = NULL;
1610 off = 0; /* fool gcc */
1611 sa6_src = &sa6_any;
1612 }
1613
1614 if (ip6 != NULL) {
1615 struct in_conninfo inc;
1616 /*
1617 * XXX: We assume that when IPV6 is non NULL,
1618 * M and OFF are valid.
1619 */
1620
1621 /* check if we can safely examine src and dst ports */
1622 if (m->m_pkthdr.len < off + sizeof *thp)
1623 goto out;
1624
1625 bzero(&th, sizeof th);
1626 m_copydata(m, off, sizeof *thp, &th);
1627
1628 in6_pcbnotify(&tcbinfo[0], sa, th.th_dport,
1629 (struct sockaddr *)ip6cp->ip6c_src,
1630 th.th_sport, cmd, arg, notify);
1631
1632 inc.inc_fport = th.th_dport;
1633 inc.inc_lport = th.th_sport;
1634 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1635 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1636 inc.inc_isipv6 = 1;
1637 syncache_unreach(&inc, &th);
1638 } else {
1639 in6_pcbnotify(&tcbinfo[0], sa, 0,
1640 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify);
1641 }
1642 out:
1643 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
1644 }
1645
1646 #endif
1647
1648 /*
1649 * Following is where TCP initial sequence number generation occurs.
1650 *
1651 * There are two places where we must use initial sequence numbers:
1652 * 1. In SYN-ACK packets.
1653 * 2. In SYN packets.
1654 *
1655 * All ISNs for SYN-ACK packets are generated by the syncache. See
1656 * tcp_syncache.c for details.
1657 *
1658 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1659 * depends on this property. In addition, these ISNs should be
1660 * unguessable so as to prevent connection hijacking. To satisfy
1661 * the requirements of this situation, the algorithm outlined in
1662 * RFC 1948 is used to generate sequence numbers.
1663 *
1664 * Implementation details:
1665 *
1666 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1667 * between the seeding of isn_secret. On every reseed we jump the
1668 * ISN by a lot.
1669 */
1670 struct tcp_isn {
1671 u_char secret[16];
1672 MD5_CTX ctx;
1673 int last_reseed;
1674 int last_offset;
1675 } __cachealign;
1676
1677 struct tcp_isn tcp_isn_ary[MAXCPU];
1678
1679 tcp_seq
tcp_new_isn(struct tcpcb * tp)1680 tcp_new_isn(struct tcpcb *tp)
1681 {
1682 struct tcp_isn *isn;
1683 tcp_seq new_isn;
1684 tcp_seq digest[16 / sizeof(tcp_seq)];
1685 int n;
1686
1687 isn = &tcp_isn_ary[mycpuid];
1688
1689 /*
1690 * Reseed every 20 seconds. 6 reseeds per 2-minute interval in
1691 * order to retain our monotonic offset.
1692 *
1693 * The initial seed randomizes last_offset with all 32 bits.
1694 *
1695 * Note that the md5 digest is masked with 0x0FFFFFFF, so we must
1696 * add 1/16 of our full range (1/8 of our signed range) to ensure
1697 * monotonic operation.
1698 */
1699 if (isn->last_reseed == 0 ||
1700 (u_int)(ticks - isn->last_reseed) > tcp_isn_reseed_interval * hz) {
1701 if (isn->last_reseed == 0) {
1702 read_random(&isn->last_offset,
1703 sizeof(isn->last_offset), 1);
1704 }
1705 read_random(&isn->secret, sizeof(isn->secret), 1);
1706 isn->last_reseed = ticks;
1707 isn->last_offset += 0x10000000;
1708 }
1709
1710 /*
1711 * Compute the md5 hash, giving us a deterministic result for the
1712 * port/address pair for any given secret.
1713 */
1714 MD5Init(&isn->ctx);
1715 MD5Update(&isn->ctx, isn->secret, sizeof(isn->secret));
1716 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_fport, 2);
1717 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_lport, 2);
1718 #ifdef INET6
1719 if (INP_ISIPV6(tp->t_inpcb)) {
1720 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->in6p_faddr,
1721 sizeof(struct in6_addr));
1722 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->in6p_laddr,
1723 sizeof(struct in6_addr));
1724 } else
1725 #endif
1726 {
1727 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_faddr,
1728 sizeof(struct in_addr));
1729 MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_laddr,
1730 sizeof(struct in_addr));
1731 }
1732 MD5Final((char *)digest, &isn->ctx);
1733
1734 /*
1735 * Add a random component 0-1048575 plus advance by 1048576.
1736 *
1737 * The sequence space is simply too small, in modern times we also
1738 * must depend on the receive-side being a bit smarter when recycling
1739 * ports in TIME_WAIT.
1740 */
1741 read_random(&n, sizeof(n), 1);
1742 isn->last_offset += (n & 0x000FFFFF) + 0x00100000;
1743 new_isn = (digest[0] & 0x0FFFFFFF) + isn->last_offset;
1744
1745 return (new_isn);
1746 }
1747
1748 /*
1749 * When a source quench is received, close congestion window
1750 * to one segment. We will gradually open it again as we proceed.
1751 */
1752 void
tcp_quench(struct inpcb * inp,int error)1753 tcp_quench(struct inpcb *inp, int error)
1754 {
1755 struct tcpcb *tp = intotcpcb(inp);
1756
1757 KASSERT(tp != NULL, ("tcp_quench: tp is NULL"));
1758 tp->snd_cwnd = tp->t_maxseg;
1759 tp->snd_wacked = 0;
1760 }
1761
1762 /*
1763 * When a specific ICMP unreachable message is received and the
1764 * connection state is SYN-SENT, drop the connection. This behavior
1765 * is controlled by the icmp_may_rst sysctl.
1766 */
1767 void
tcp_drop_syn_sent(struct inpcb * inp,int error)1768 tcp_drop_syn_sent(struct inpcb *inp, int error)
1769 {
1770 struct tcpcb *tp = intotcpcb(inp);
1771
1772 KASSERT(tp != NULL, ("tcp_drop_syn_sent: tp is NULL"));
1773 if (tp->t_state == TCPS_SYN_SENT)
1774 tcp_drop(tp, error);
1775 }
1776
1777 /*
1778 * When a `need fragmentation' ICMP is received, update our idea of the MSS
1779 * based on the new value in the route. Also nudge TCP to send something,
1780 * since we know the packet we just sent was dropped.
1781 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1782 */
1783 void
tcp_mtudisc(struct inpcb * inp,int mtu)1784 tcp_mtudisc(struct inpcb *inp, int mtu)
1785 {
1786 struct tcpcb *tp = intotcpcb(inp);
1787 struct rtentry *rt;
1788 struct socket *so = inp->inp_socket;
1789 int maxopd, mss;
1790 #ifdef INET6
1791 boolean_t isipv6 = INP_ISIPV6(inp);
1792 #else
1793 const boolean_t isipv6 = FALSE;
1794 #endif
1795
1796 KASSERT(tp != NULL, ("tcp_mtudisc: tp is NULL"));
1797
1798 /*
1799 * If no MTU is provided in the ICMP message, use the
1800 * next lower likely value, as specified in RFC 1191.
1801 */
1802 if (mtu == 0) {
1803 int oldmtu;
1804
1805 oldmtu = tp->t_maxopd +
1806 (isipv6 ?
1807 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1808 sizeof(struct tcpiphdr));
1809 mtu = ip_next_mtu(oldmtu, 0);
1810 }
1811
1812 if (isipv6)
1813 rt = tcp_rtlookup6(&inp->inp_inc);
1814 else
1815 rt = tcp_rtlookup(&inp->inp_inc);
1816 if (rt != NULL) {
1817 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu)
1818 mtu = rt->rt_rmx.rmx_mtu;
1819
1820 maxopd = mtu -
1821 (isipv6 ?
1822 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1823 sizeof(struct tcpiphdr));
1824
1825 /*
1826 * XXX - The following conditional probably violates the TCP
1827 * spec. The problem is that, since we don't know the
1828 * other end's MSS, we are supposed to use a conservative
1829 * default. But, if we do that, then MTU discovery will
1830 * never actually take place, because the conservative
1831 * default is much less than the MTUs typically seen
1832 * on the Internet today. For the moment, we'll sweep
1833 * this under the carpet.
1834 *
1835 * The conservative default might not actually be a problem
1836 * if the only case this occurs is when sending an initial
1837 * SYN with options and data to a host we've never talked
1838 * to before. Then, they will reply with an MSS value which
1839 * will get recorded and the new parameters should get
1840 * recomputed. For Further Study.
1841 */
1842 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd)
1843 maxopd = rt->rt_rmx.rmx_mssopt;
1844 } else
1845 maxopd = mtu -
1846 (isipv6 ?
1847 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
1848 sizeof(struct tcpiphdr));
1849
1850 if (tp->t_maxopd <= maxopd)
1851 return;
1852 tp->t_maxopd = maxopd;
1853
1854 mss = maxopd;
1855 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) ==
1856 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
1857 mss -= TCPOLEN_TSTAMP_APPA;
1858
1859 /* round down to multiple of MCLBYTES */
1860 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */
1861 if (mss > MCLBYTES)
1862 mss &= ~(MCLBYTES - 1);
1863 #else
1864 if (mss > MCLBYTES)
1865 mss = rounddown(mss, MCLBYTES);
1866 #endif
1867
1868 if (so->so_snd.ssb_hiwat < mss)
1869 mss = so->so_snd.ssb_hiwat;
1870
1871 tp->t_maxseg = mss;
1872 tp->t_rtttime = 0;
1873 tp->snd_nxt = tp->snd_una;
1874 tcp_output(tp);
1875 tcpstat.tcps_mturesent++;
1876 }
1877
1878 /*
1879 * Look-up the routing entry to the peer of this inpcb. If no route
1880 * is found and it cannot be allocated the return NULL. This routine
1881 * is called by TCP routines that access the rmx structure and by tcp_mss
1882 * to get the interface MTU.
1883 */
1884 struct rtentry *
tcp_rtlookup(struct in_conninfo * inc)1885 tcp_rtlookup(struct in_conninfo *inc)
1886 {
1887 struct route *ro = &inc->inc_route;
1888
1889 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) {
1890 /* No route yet, so try to acquire one */
1891 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1892 /*
1893 * unused portions of the structure MUST be zero'd
1894 * out because rtalloc() treats it as opaque data
1895 */
1896 bzero(&ro->ro_dst, sizeof(struct sockaddr_in));
1897 ro->ro_dst.sa_family = AF_INET;
1898 ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
1899 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
1900 inc->inc_faddr;
1901 rtalloc(ro);
1902 }
1903 }
1904 return (ro->ro_rt);
1905 }
1906
1907 #ifdef INET6
1908 struct rtentry *
tcp_rtlookup6(struct in_conninfo * inc)1909 tcp_rtlookup6(struct in_conninfo *inc)
1910 {
1911 struct route_in6 *ro6 = &inc->inc6_route;
1912
1913 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) {
1914 /* No route yet, so try to acquire one */
1915 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1916 /*
1917 * unused portions of the structure MUST be zero'd
1918 * out because rtalloc() treats it as opaque data
1919 */
1920 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6));
1921 ro6->ro_dst.sin6_family = AF_INET6;
1922 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1923 ro6->ro_dst.sin6_addr = inc->inc6_faddr;
1924 rtalloc((struct route *)ro6);
1925 }
1926 }
1927 return (ro6->ro_rt);
1928 }
1929 #endif
1930
1931 /*
1932 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
1933 *
1934 * This code attempts to calculate the bandwidth-delay product as a
1935 * means of determining the optimal window size to maximize bandwidth,
1936 * minimize RTT, and avoid the over-allocation of buffers on interfaces and
1937 * routers. This code also does a fairly good job keeping RTTs in check
1938 * across slow links like modems. We implement an algorithm which is very
1939 * similar (but not meant to be) TCP/Vegas. The code operates on the
1940 * transmitter side of a TCP connection and so only effects the transmit
1941 * side of the connection.
1942 *
1943 * BACKGROUND: TCP makes no provision for the management of buffer space
1944 * at the end points or at the intermediate routers and switches. A TCP
1945 * stream, whether using NewReno or not, will eventually buffer as
1946 * many packets as it is able and the only reason this typically works is
1947 * due to the fairly small default buffers made available for a connection
1948 * (typicaly 16K or 32K). As machines use larger windows and/or window
1949 * scaling it is now fairly easy for even a single TCP connection to blow-out
1950 * all available buffer space not only on the local interface, but on
1951 * intermediate routers and switches as well. NewReno makes a misguided
1952 * attempt to 'solve' this problem by waiting for an actual failure to occur,
1953 * then backing off, then steadily increasing the window again until another
1954 * failure occurs, ad-infinitum. This results in terrible oscillation that
1955 * is only made worse as network loads increase and the idea of intentionally
1956 * blowing out network buffers is, frankly, a terrible way to manage network
1957 * resources.
1958 *
1959 * It is far better to limit the transmit window prior to the failure
1960 * condition being achieved. There are two general ways to do this: First
1961 * you can 'scan' through different transmit window sizes and locate the
1962 * point where the RTT stops increasing, indicating that you have filled the
1963 * pipe, then scan backwards until you note that RTT stops decreasing, then
1964 * repeat ad-infinitum. This method works in principle but has severe
1965 * implementation issues due to RTT variances, timer granularity, and
1966 * instability in the algorithm which can lead to many false positives and
1967 * create oscillations as well as interact badly with other TCP streams
1968 * implementing the same algorithm.
1969 *
1970 * The second method is to limit the window to the bandwidth delay product
1971 * of the link. This is the method we implement. RTT variances and our
1972 * own manipulation of the congestion window, bwnd, can potentially
1973 * destabilize the algorithm. For this reason we have to stabilize the
1974 * elements used to calculate the window. We do this by using the minimum
1975 * observed RTT, the long term average of the observed bandwidth, and
1976 * by adding two segments worth of slop. It isn't perfect but it is able
1977 * to react to changing conditions and gives us a very stable basis on
1978 * which to extend the algorithm.
1979 */
1980 void
tcp_xmit_bandwidth_limit(struct tcpcb * tp,tcp_seq ack_seq)1981 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
1982 {
1983 u_long bw;
1984 u_long ibw;
1985 u_long bwnd;
1986 int save_ticks;
1987 int delta_ticks;
1988
1989 /*
1990 * If inflight_enable is disabled in the middle of a tcp connection,
1991 * make sure snd_bwnd is effectively disabled.
1992 */
1993 if (!tcp_inflight_enable) {
1994 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
1995 tp->snd_bandwidth = 0;
1996 return;
1997 }
1998
1999 /*
2000 * Validate the delta time. If a connection is new or has been idle
2001 * a long time we have to reset the bandwidth calculator.
2002 */
2003 save_ticks = ticks;
2004 cpu_ccfence();
2005 delta_ticks = save_ticks - tp->t_bw_rtttime;
2006 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) {
2007 tp->t_bw_rtttime = save_ticks;
2008 tp->t_bw_rtseq = ack_seq;
2009 if (tp->snd_bandwidth == 0)
2010 tp->snd_bandwidth = tcp_inflight_start;
2011 return;
2012 }
2013
2014 /*
2015 * A delta of at least 1 tick is required. Waiting 2 ticks will
2016 * result in better (bw) accuracy. More than that and the ramp-up
2017 * will be too slow.
2018 */
2019 if (delta_ticks == 0 || delta_ticks == 1)
2020 return;
2021
2022 /*
2023 * Sanity check, plus ignore pure window update acks.
2024 */
2025 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0)
2026 return;
2027
2028 /*
2029 * Figure out the bandwidth. Due to the tick granularity this
2030 * is a very rough number and it MUST be averaged over a fairly
2031 * long period of time. XXX we need to take into account a link
2032 * that is not using all available bandwidth, but for now our
2033 * slop will ramp us up if this case occurs and the bandwidth later
2034 * increases.
2035 */
2036 ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks;
2037 tp->t_bw_rtttime = save_ticks;
2038 tp->t_bw_rtseq = ack_seq;
2039 bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4;
2040
2041 tp->snd_bandwidth = bw;
2042
2043 /*
2044 * Calculate the semi-static bandwidth delay product, plus two maximal
2045 * segments. The additional slop puts us squarely in the sweet
2046 * spot and also handles the bandwidth run-up case. Without the
2047 * slop we could be locking ourselves into a lower bandwidth.
2048 *
2049 * At very high speeds the bw calculation can become overly sensitive
2050 * and error prone when delta_ticks is low (e.g. usually 1). To deal
2051 * with the problem the stab must be scaled to the bw. A stab of 50
2052 * (the default) increases the bw for the purposes of the bwnd
2053 * calculation by 5%.
2054 *
2055 * Situations Handled:
2056 * (1) Prevents over-queueing of packets on LANs, especially on
2057 * high speed LANs, allowing larger TCP buffers to be
2058 * specified, and also does a good job preventing
2059 * over-queueing of packets over choke points like modems
2060 * (at least for the transmit side).
2061 *
2062 * (2) Is able to handle changing network loads (bandwidth
2063 * drops so bwnd drops, bandwidth increases so bwnd
2064 * increases).
2065 *
2066 * (3) Theoretically should stabilize in the face of multiple
2067 * connections implementing the same algorithm (this may need
2068 * a little work).
2069 *
2070 * (4) Stability value (defaults to 20 = 2 maximal packets) can
2071 * be adjusted with a sysctl but typically only needs to be on
2072 * very slow connections. A value no smaller then 5 should
2073 * be used, but only reduce this default if you have no other
2074 * choice.
2075 */
2076
2077 #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt)
2078 bw += bw * tcp_inflight_stab / 1000;
2079 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) +
2080 (int)tp->t_maxseg * 2;
2081 #undef USERTT
2082
2083 if (tcp_inflight_debug > 0) {
2084 static int ltime;
2085 if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) {
2086 ltime = save_ticks;
2087 kprintf("%p ibw %ld bw %ld rttvar %d srtt %d "
2088 "bwnd %ld delta %d snd_win %ld\n",
2089 tp, ibw, bw, tp->t_rttvar, tp->t_srtt,
2090 bwnd, delta_ticks, tp->snd_wnd);
2091 }
2092 }
2093 if ((long)bwnd < tcp_inflight_min)
2094 bwnd = tcp_inflight_min;
2095 if (bwnd > tcp_inflight_max)
2096 bwnd = tcp_inflight_max;
2097 if ((long)bwnd < tp->t_maxseg * 2)
2098 bwnd = tp->t_maxseg * 2;
2099 tp->snd_bwnd = bwnd;
2100 }
2101
2102 static void
tcp_rmx_iwsegs(struct tcpcb * tp,u_long * maxsegs,u_long * capsegs)2103 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs)
2104 {
2105 struct rtentry *rt;
2106 struct inpcb *inp = tp->t_inpcb;
2107 #ifdef INET6
2108 boolean_t isipv6 = INP_ISIPV6(inp);
2109 #else
2110 const boolean_t isipv6 = FALSE;
2111 #endif
2112
2113 /* XXX */
2114 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT)
2115 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT;
2116 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT)
2117 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT;
2118
2119 if (isipv6)
2120 rt = tcp_rtlookup6(&inp->inp_inc);
2121 else
2122 rt = tcp_rtlookup(&inp->inp_inc);
2123 if (rt == NULL ||
2124 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT ||
2125 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) {
2126 *maxsegs = tcp_iw_maxsegs;
2127 *capsegs = tcp_iw_capsegs;
2128 return;
2129 }
2130 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs;
2131 *capsegs = rt->rt_rmx.rmx_iwcapsegs;
2132 }
2133
2134 u_long
tcp_initial_window(struct tcpcb * tp)2135 tcp_initial_window(struct tcpcb *tp)
2136 {
2137 if (tcp_do_rfc3390) {
2138 /*
2139 * RFC3390:
2140 * "If the SYN or SYN/ACK is lost, the initial window
2141 * used by a sender after a correctly transmitted SYN
2142 * MUST be one segment consisting of MSS bytes."
2143 *
2144 * However, we do something a little bit more aggressive
2145 * then RFC3390 here:
2146 * - Only if time spent in the SYN or SYN|ACK retransmition
2147 * >= 3 seconds, the IW is reduced. We do this mainly
2148 * because when RFC3390 is published, the initial RTO is
2149 * still 3 seconds (the threshold we test here), while
2150 * after RFC6298, the initial RTO is 1 second. This
2151 * behaviour probably still falls within the spirit of
2152 * RFC3390.
2153 * - When IW is reduced, 2*MSS is used instead of 1*MSS.
2154 * Mainly to avoid sender and receiver deadlock until
2155 * delayed ACK timer expires. And even RFC2581 does not
2156 * try to reduce IW upon SYN or SYN|ACK retransmition
2157 * timeout.
2158 *
2159 * See also:
2160 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03
2161 */
2162 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) {
2163 return (2 * tp->t_maxseg);
2164 } else {
2165 u_long maxsegs, capsegs;
2166
2167 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs);
2168 return min(maxsegs * tp->t_maxseg,
2169 max(2 * tp->t_maxseg, capsegs * 1460));
2170 }
2171 } else {
2172 /*
2173 * Even RFC2581 (back to 1999) allows 2*SMSS IW.
2174 *
2175 * Mainly to avoid sender and receiver deadlock
2176 * until delayed ACK timer expires.
2177 */
2178 return (2 * tp->t_maxseg);
2179 }
2180 }
2181
2182 #ifdef TCP_SIGNATURE
2183 /*
2184 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
2185 *
2186 * We do this over ip, tcphdr, segment data, and the key in the SADB.
2187 * When called from tcp_input(), we can be sure that th_sum has been
2188 * zeroed out and verified already.
2189 *
2190 * Return 0 if successful, otherwise return -1.
2191 *
2192 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
2193 * search with the destination IP address, and a 'magic SPI' to be
2194 * determined by the application. This is hardcoded elsewhere to 1179
2195 * right now. Another branch of this code exists which uses the SPD to
2196 * specify per-application flows but it is unstable.
2197 */
2198 int
tcpsignature_compute(struct mbuf * m,int len,int optlen,u_char * buf,u_int direction)2199 tcpsignature_compute(
2200 struct mbuf *m, /* mbuf chain */
2201 int len, /* length of TCP data */
2202 int optlen, /* length of TCP options */
2203 u_char *buf, /* storage for MD5 digest */
2204 u_int direction) /* direction of flow */
2205 {
2206 struct ippseudo ippseudo;
2207 MD5_CTX ctx;
2208 int doff;
2209 struct ip *ip;
2210 struct ipovly *ipovly;
2211 struct secasvar *sav;
2212 struct tcphdr *th;
2213 #ifdef INET6
2214 struct ip6_hdr *ip6;
2215 struct in6_addr in6;
2216 uint32_t plen;
2217 uint16_t nhdr;
2218 #endif /* INET6 */
2219 u_short savecsum;
2220
2221 KASSERT(m != NULL, ("passed NULL mbuf. Game over."));
2222 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature"));
2223 /*
2224 * Extract the destination from the IP header in the mbuf.
2225 */
2226 ip = mtod(m, struct ip *);
2227 #ifdef INET6
2228 ip6 = NULL; /* Make the compiler happy. */
2229 #endif /* INET6 */
2230 /*
2231 * Look up an SADB entry which matches the address found in
2232 * the segment.
2233 */
2234 switch (IP_VHL_V(ip->ip_vhl)) {
2235 case IPVERSION:
2236 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
2237 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2238 break;
2239 #ifdef INET6
2240 case (IPV6_VERSION >> 4):
2241 ip6 = mtod(m, struct ip6_hdr *);
2242 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
2243 IPPROTO_TCP, htonl(TCP_SIG_SPI));
2244 break;
2245 #endif /* INET6 */
2246 default:
2247 return (EINVAL);
2248 /* NOTREACHED */
2249 break;
2250 }
2251 if (sav == NULL) {
2252 kprintf("%s: SADB lookup failed\n", __func__);
2253 return (EINVAL);
2254 }
2255 MD5Init(&ctx);
2256
2257 /*
2258 * Step 1: Update MD5 hash with IP pseudo-header.
2259 *
2260 * XXX The ippseudo header MUST be digested in network byte order,
2261 * or else we'll fail the regression test. Assume all fields we've
2262 * been doing arithmetic on have been in host byte order.
2263 * XXX One cannot depend on ipovly->ih_len here. When called from
2264 * tcp_output(), the underlying ip_len member has not yet been set.
2265 */
2266 switch (IP_VHL_V(ip->ip_vhl)) {
2267 case IPVERSION:
2268 ipovly = (struct ipovly *)ip;
2269 ippseudo.ippseudo_src = ipovly->ih_src;
2270 ippseudo.ippseudo_dst = ipovly->ih_dst;
2271 ippseudo.ippseudo_pad = 0;
2272 ippseudo.ippseudo_p = IPPROTO_TCP;
2273 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen);
2274 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2275 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2276 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2277 break;
2278 #ifdef INET6
2279 /*
2280 * RFC 2385, 2.0 Proposal
2281 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2282 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2283 * extended next header value (to form 32 bits), and 32-bit segment
2284 * length.
2285 * Note: Upper-Layer Packet Length comes before Next Header.
2286 */
2287 case (IPV6_VERSION >> 4):
2288 in6 = ip6->ip6_src;
2289 in6_clearscope(&in6);
2290 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2291 in6 = ip6->ip6_dst;
2292 in6_clearscope(&in6);
2293 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2294 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2295 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2296 nhdr = 0;
2297 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2298 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2299 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2300 nhdr = IPPROTO_TCP;
2301 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2302 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2303 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2304 break;
2305 #endif /* INET6 */
2306 default:
2307 return (EINVAL);
2308 /* NOTREACHED */
2309 break;
2310 }
2311 /*
2312 * Step 2: Update MD5 hash with TCP header, excluding options.
2313 * The TCP checksum must be set to zero.
2314 */
2315 savecsum = th->th_sum;
2316 th->th_sum = 0;
2317 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2318 th->th_sum = savecsum;
2319 /*
2320 * Step 3: Update MD5 hash with TCP segment data.
2321 * Use m_apply() to avoid an early m_pullup().
2322 */
2323 if (len > 0)
2324 m_apply(m, doff, len, tcpsignature_apply, &ctx);
2325 /*
2326 * Step 4: Update MD5 hash with shared secret.
2327 */
2328 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
2329 MD5Final(buf, &ctx);
2330 key_sa_recordxfer(sav, m);
2331 key_freesav(sav);
2332 return (0);
2333 }
2334
2335 int
tcpsignature_apply(void * fstate,void * data,unsigned int len)2336 tcpsignature_apply(void *fstate, void *data, unsigned int len)
2337 {
2338
2339 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len);
2340 return (0);
2341 }
2342 #endif /* TCP_SIGNATURE */
2343
2344 static void
tcp_drop_sysctl_dispatch(netmsg_t nmsg)2345 tcp_drop_sysctl_dispatch(netmsg_t nmsg)
2346 {
2347 struct lwkt_msg *lmsg = &nmsg->lmsg;
2348 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2349 struct sockaddr_storage *addrs = lmsg->u.ms_resultp;
2350 int error;
2351 struct sockaddr_in *fin, *lin;
2352 #ifdef INET6
2353 struct sockaddr_in6 *fin6, *lin6;
2354 struct in6_addr f6, l6;
2355 #endif
2356 struct inpcb *inp;
2357
2358 switch (addrs[0].ss_family) {
2359 #ifdef INET6
2360 case AF_INET6:
2361 fin6 = (struct sockaddr_in6 *)&addrs[0];
2362 lin6 = (struct sockaddr_in6 *)&addrs[1];
2363 error = in6_embedscope(&f6, fin6, NULL, NULL);
2364 if (error)
2365 goto done;
2366 error = in6_embedscope(&l6, lin6, NULL, NULL);
2367 if (error)
2368 goto done;
2369 inp = in6_pcblookup_hash(&tcbinfo[mycpuid], &f6,
2370 fin6->sin6_port, &l6, lin6->sin6_port, FALSE, NULL);
2371 break;
2372 #endif
2373 #ifdef INET
2374 case AF_INET:
2375 fin = (struct sockaddr_in *)&addrs[0];
2376 lin = (struct sockaddr_in *)&addrs[1];
2377 inp = in_pcblookup_hash(&tcbinfo[mycpuid], fin->sin_addr,
2378 fin->sin_port, lin->sin_addr, lin->sin_port, FALSE, NULL);
2379 break;
2380 #endif
2381 default:
2382 /*
2383 * Must not reach here, since the address family was
2384 * checked in sysctl handler.
2385 */
2386 panic("unknown address family %d", addrs[0].ss_family);
2387 }
2388 if (inp != NULL) {
2389 struct tcpcb *tp = intotcpcb(inp);
2390
2391 KASSERT((inp->inp_flags & INP_WILDCARD) == 0,
2392 ("in wildcard hash"));
2393 KASSERT(tp != NULL, ("tcp_drop_sysctl_dispatch: tp is NULL"));
2394 KASSERT((tp->t_flags & TF_LISTEN) == 0, ("listen socket"));
2395 tcp_drop(tp, ECONNABORTED);
2396 error = 0;
2397 } else {
2398 error = ESRCH;
2399 }
2400 #ifdef INET6
2401 done:
2402 #endif
2403 lwkt_replymsg(lmsg, error);
2404 }
2405
2406 static int
sysctl_tcp_drop(SYSCTL_HANDLER_ARGS)2407 sysctl_tcp_drop(SYSCTL_HANDLER_ARGS)
2408 {
2409 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2410 struct sockaddr_storage addrs[2];
2411 struct sockaddr_in *fin, *lin;
2412 #ifdef INET6
2413 struct sockaddr_in6 *fin6, *lin6;
2414 #endif
2415 struct netmsg_base nmsg;
2416 struct lwkt_msg *lmsg = &nmsg.lmsg;
2417 struct lwkt_port *port = NULL;
2418 int error;
2419
2420 fin = lin = NULL;
2421 #ifdef INET6
2422 fin6 = lin6 = NULL;
2423 #endif
2424 error = 0;
2425
2426 if (req->oldptr != NULL || req->oldlen != 0)
2427 return (EINVAL);
2428 if (req->newptr == NULL)
2429 return (EPERM);
2430 if (req->newlen < sizeof(addrs))
2431 return (ENOMEM);
2432 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2433 if (error)
2434 return (error);
2435
2436 switch (addrs[0].ss_family) {
2437 #ifdef INET6
2438 case AF_INET6:
2439 fin6 = (struct sockaddr_in6 *)&addrs[0];
2440 lin6 = (struct sockaddr_in6 *)&addrs[1];
2441 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2442 lin6->sin6_len != sizeof(struct sockaddr_in6))
2443 return (EINVAL);
2444 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr) ||
2445 IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2446 return (EADDRNOTAVAIL);
2447 #if 0
2448 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2449 if (error)
2450 return (error);
2451 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2452 if (error)
2453 return (error);
2454 #endif
2455 port = tcp6_addrport();
2456 break;
2457 #endif
2458 #ifdef INET
2459 case AF_INET:
2460 fin = (struct sockaddr_in *)&addrs[0];
2461 lin = (struct sockaddr_in *)&addrs[1];
2462 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2463 lin->sin_len != sizeof(struct sockaddr_in))
2464 return (EINVAL);
2465 port = tcp_addrport(fin->sin_addr.s_addr, fin->sin_port,
2466 lin->sin_addr.s_addr, lin->sin_port);
2467 break;
2468 #endif
2469 default:
2470 return (EINVAL);
2471 }
2472
2473 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
2474 tcp_drop_sysctl_dispatch);
2475 lmsg->u.ms_resultp = addrs;
2476 return lwkt_domsg(port, lmsg, 0);
2477 }
2478
2479 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, drop,
2480 CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL,
2481 0, sysctl_tcp_drop, "", "Drop TCP connection");
2482
2483 static int
sysctl_tcps_count(SYSCTL_HANDLER_ARGS)2484 sysctl_tcps_count(SYSCTL_HANDLER_ARGS)
2485 {
2486 u_long state_count[TCP_NSTATES];
2487 int cpu;
2488
2489 memset(state_count, 0, sizeof(state_count));
2490 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
2491 int i;
2492
2493 for (i = 0; i < TCP_NSTATES; ++i)
2494 state_count[i] += tcpstate_count[cpu].tcps_count[i];
2495 }
2496
2497 return sysctl_handle_opaque(oidp, state_count, sizeof(state_count), req);
2498 }
2499 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, state_count,
2500 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
2501 sysctl_tcps_count, "LU", "TCP connection counts by state");
2502
2503 void
tcp_pcbport_create(struct tcpcb * tp)2504 tcp_pcbport_create(struct tcpcb *tp)
2505 {
2506 int cpu;
2507
2508 KASSERT((tp->t_flags & TF_LISTEN) && tp->t_state == TCPS_LISTEN,
2509 ("not a listen tcpcb"));
2510
2511 KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache was created"));
2512 tp->t_pcbport =
2513 kmalloc(sizeof(struct tcp_pcbport) * netisr_ncpus,
2514 M_PCB,
2515 M_WAITOK | M_CACHEALIGN);
2516
2517 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
2518 struct inpcbport *phd;
2519
2520 phd = &tp->t_pcbport[cpu].t_phd;
2521 LIST_INIT(&phd->phd_pcblist);
2522 /* Though, not used ... */
2523 phd->phd_port = tp->t_inpcb->inp_lport;
2524 }
2525 }
2526
2527 void
tcp_pcbport_merge_oncpu(struct tcpcb * tp)2528 tcp_pcbport_merge_oncpu(struct tcpcb *tp)
2529 {
2530 struct inpcbport *phd;
2531 struct inpcb *inp;
2532 int cpu = mycpuid;
2533
2534 KASSERT(cpu < netisr_ncpus, ("invalid cpu%d", cpu));
2535 phd = &tp->t_pcbport[cpu].t_phd;
2536
2537 while ((inp = LIST_FIRST(&phd->phd_pcblist)) != NULL) {
2538 KASSERT(inp->inp_phd == phd && inp->inp_porthash == NULL,
2539 ("not on tcpcb port cache"));
2540 LIST_REMOVE(inp, inp_portlist);
2541 in_pcbinsporthash_lport(inp);
2542 KASSERT(inp->inp_phd == tp->t_inpcb->inp_phd &&
2543 inp->inp_porthash == tp->t_inpcb->inp_porthash,
2544 ("tcpcb port cache merge failed"));
2545 }
2546 }
2547
2548 void
tcp_pcbport_destroy(struct tcpcb * tp)2549 tcp_pcbport_destroy(struct tcpcb *tp)
2550 {
2551 #ifdef INVARIANTS
2552 int cpu;
2553
2554 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
2555 KASSERT(LIST_EMPTY(&tp->t_pcbport[cpu].t_phd.phd_pcblist),
2556 ("tcpcb port cache is not empty"));
2557 }
2558 #endif
2559 kfree(tp->t_pcbport, M_PCB);
2560 tp->t_pcbport = NULL;
2561 }
2562