1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/10.1/sys/netinet/tcp_subr.c 285979 2015-07-28 19:59:11Z delphij $");
34
35 #include "opt_compat.h"
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_ipsec.h"
39 #include "opt_kdtrace.h"
40 #include "opt_tcpdebug.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/callout.h>
45 #include <sys/hhook.h>
46 #include <sys/kernel.h>
47 #include <sys/khelp.h>
48 #include <sys/sysctl.h>
49 #include <sys/jail.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #ifdef INET6
53 #include <sys/domain.h>
54 #endif
55 #include <sys/priv.h>
56 #include <sys/proc.h>
57 #include <sys/sdt.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/protosw.h>
61 #include <sys/random.h>
62
63 #include <vm/uma.h>
64
65 #include <net/route.h>
66 #include <net/if.h>
67 #include <net/vnet.h>
68
69 #include <netinet/cc.h>
70 #include <netinet/in.h>
71 #include <netinet/in_kdtrace.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_systm.h>
74 #include <netinet/in_var.h>
75 #include <netinet/ip.h>
76 #include <netinet/ip_icmp.h>
77 #include <netinet/ip_var.h>
78 #ifdef INET6
79 #include <netinet/ip6.h>
80 #include <netinet6/in6_pcb.h>
81 #include <netinet6/ip6_var.h>
82 #include <netinet6/scope6_var.h>
83 #include <netinet6/nd6.h>
84 #endif
85
86 #include <netinet/tcp_fsm.h>
87 #include <netinet/tcp_seq.h>
88 #include <netinet/tcp_timer.h>
89 #include <netinet/tcp_var.h>
90 #include <netinet/tcp_syncache.h>
91 #ifdef INET6
92 #include <netinet6/tcp6_var.h>
93 #endif
94 #include <netinet/tcpip.h>
95 #ifdef TCPDEBUG
96 #include <netinet/tcp_debug.h>
97 #endif
98 #ifdef INET6
99 #include <netinet6/ip6protosw.h>
100 #endif
101 #ifdef TCP_OFFLOAD
102 #include <netinet/tcp_offload.h>
103 #endif
104
105 #ifdef IPSEC
106 #include <netipsec/ipsec.h>
107 #include <netipsec/xform.h>
108 #ifdef INET6
109 #include <netipsec/ipsec6.h>
110 #endif
111 #include <netipsec/key.h>
112 #include <sys/syslog.h>
113 #endif /*IPSEC*/
114
115 #include <machine/in_cksum.h>
116 #include <sys/md5.h>
117
118 #include <security/mac/mac_framework.h>
119
120 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
121 #ifdef INET6
122 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
123 #endif
124
125 static int
126 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
127 {
128 int error, new;
129
130 new = V_tcp_mssdflt;
131 error = sysctl_handle_int(oidp, &new, 0, req);
132 if (error == 0 && req->newptr) {
133 if (new < TCP_MINMSS)
134 error = EINVAL;
135 else
136 V_tcp_mssdflt = new;
137 }
138 return (error);
139 }
140
141 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
142 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
143 &sysctl_net_inet_tcp_mss_check, "I",
144 "Default TCP Maximum Segment Size");
145
146 #ifdef INET6
147 static int
148 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
149 {
150 int error, new;
151
152 new = V_tcp_v6mssdflt;
153 error = sysctl_handle_int(oidp, &new, 0, req);
154 if (error == 0 && req->newptr) {
155 if (new < TCP_MINMSS)
156 error = EINVAL;
157 else
158 V_tcp_v6mssdflt = new;
159 }
160 return (error);
161 }
162
163 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
164 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
165 &sysctl_net_inet_tcp_mss_v6_check, "I",
166 "Default TCP Maximum Segment Size for IPv6");
167 #endif /* INET6 */
168
169 /*
170 * Minimum MSS we accept and use. This prevents DoS attacks where
171 * we are forced to a ridiculous low MSS like 20 and send hundreds
172 * of packets instead of one. The effect scales with the available
173 * bandwidth and quickly saturates the CPU and network interface
174 * with packet generation and sending. Set to zero to disable MINMSS
175 * checking. This setting prevents us from sending too small packets.
176 */
177 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
178 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
179 &VNET_NAME(tcp_minmss), 0,
180 "Minimum TCP Maximum Segment Size");
181
182 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
183 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
184 &VNET_NAME(tcp_do_rfc1323), 0,
185 "Enable rfc1323 (high performance TCP) extensions");
186
187 static int tcp_log_debug = 0;
188 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
189 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
190
191 static int tcp_tcbhashsize = 0;
192 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
193 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
194
195 static int do_tcpdrain = 1;
196 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
197 "Enable tcp_drain routine for extra help when low on mbufs");
198
199 SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
200 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
201
202 static VNET_DEFINE(int, icmp_may_rst) = 1;
203 #define V_icmp_may_rst VNET(icmp_may_rst)
204 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
205 &VNET_NAME(icmp_may_rst), 0,
206 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
207
208 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
209 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
210 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
211 &VNET_NAME(tcp_isn_reseed_interval), 0,
212 "Seconds between reseeding of ISN secret");
213
214 static int tcp_soreceive_stream = 0;
215 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
216 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
217
218 #ifdef TCP_SIGNATURE
219 static int tcp_sig_checksigs = 1;
220 SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW,
221 &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic");
222 #endif
223
224 VNET_DEFINE(uma_zone_t, sack_hole_zone);
225 #define V_sack_hole_zone VNET(sack_hole_zone)
226
227 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
228
229 static struct inpcb *tcp_notify(struct inpcb *, int);
230 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
231 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
232 void *ip4hdr, const void *ip6hdr);
233
234 /*
235 * Target size of TCP PCB hash tables. Must be a power of two.
236 *
237 * Note that this can be overridden by the kernel environment
238 * variable net.inet.tcp.tcbhashsize
239 */
240 #ifndef TCBHASHSIZE
241 #define TCBHASHSIZE 0
242 #endif
243
244 /*
245 * XXX
246 * Callouts should be moved into struct tcp directly. They are currently
247 * separate because the tcpcb structure is exported to userland for sysctl
248 * parsing purposes, which do not know about callouts.
249 */
250 struct tcpcb_mem {
251 struct tcpcb tcb;
252 struct tcp_timer tt;
253 struct cc_var ccv;
254 struct osd osd;
255 };
256
257 static VNET_DEFINE(uma_zone_t, tcpcb_zone);
258 #define V_tcpcb_zone VNET(tcpcb_zone)
259
260 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
261 static struct mtx isn_mtx;
262
263 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
264 #define ISN_LOCK() mtx_lock(&isn_mtx)
265 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
266
267 /*
268 * TCP initialization.
269 */
270 static void
271 tcp_zone_change(void *tag)
272 {
273
274 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
275 uma_zone_set_max(V_tcpcb_zone, maxsockets);
276 tcp_tw_zone_change();
277 }
278
279 static int
280 tcp_inpcb_init(void *mem, int size, int flags)
281 {
282 struct inpcb *inp = mem;
283
284 INP_LOCK_INIT(inp, "inp", "tcpinp");
285 return (0);
286 }
287
288 /*
289 * Take a value and get the next power of 2 that doesn't overflow.
290 * Used to size the tcp_inpcb hash buckets.
291 */
292 static int
293 maketcp_hashsize(int size)
294 {
295 int hashsize;
296
297 /*
298 * auto tune.
299 * get the next power of 2 higher than maxsockets.
300 */
301 hashsize = 1 << fls(size);
302 /* catch overflow, and just go one power of 2 smaller */
303 if (hashsize < size) {
304 hashsize = 1 << (fls(size) - 1);
305 }
306 return (hashsize);
307 }
308
309 void
310 tcp_init(void)
311 {
312 const char *tcbhash_tuneable;
313 int hashsize;
314
315 tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
316
317 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
318 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
319 printf("%s: WARNING: unable to register helper hook\n", __func__);
320 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
321 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
322 printf("%s: WARNING: unable to register helper hook\n", __func__);
323
324 hashsize = TCBHASHSIZE;
325 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
326 if (hashsize == 0) {
327 /*
328 * Auto tune the hash size based on maxsockets.
329 * A perfect hash would have a 1:1 mapping
330 * (hashsize = maxsockets) however it's been
331 * suggested that O(2) average is better.
332 */
333 hashsize = maketcp_hashsize(maxsockets / 4);
334 /*
335 * Our historical default is 512,
336 * do not autotune lower than this.
337 */
338 if (hashsize < 512)
339 hashsize = 512;
340 if (bootverbose)
341 printf("%s: %s auto tuned to %d\n", __func__,
342 tcbhash_tuneable, hashsize);
343 }
344 /*
345 * We require a hashsize to be a power of two.
346 * Previously if it was not a power of two we would just reset it
347 * back to 512, which could be a nasty surprise if you did not notice
348 * the error message.
349 * Instead what we do is clip it to the closest power of two lower
350 * than the specified hash value.
351 */
352 if (!powerof2(hashsize)) {
353 int oldhashsize = hashsize;
354
355 hashsize = maketcp_hashsize(hashsize);
356 /* prevent absurdly low value */
357 if (hashsize < 16)
358 hashsize = 16;
359 printf("%s: WARNING: TCB hash size not a power of 2, "
360 "clipped from %d to %d.\n", __func__, oldhashsize,
361 hashsize);
362 }
363 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
364 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE,
365 IPI_HASHFIELDS_4TUPLE);
366
367 /*
368 * These have to be type stable for the benefit of the timers.
369 */
370 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
371 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
372 uma_zone_set_max(V_tcpcb_zone, maxsockets);
373 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
374
375 tcp_tw_init();
376 syncache_init();
377 tcp_hc_init();
378
379 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
380 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
381 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
382
383 /* Skip initialization of globals for non-default instances. */
384 if (!IS_DEFAULT_VNET(curvnet))
385 return;
386
387 tcp_reass_global_init();
388
389 /* XXX virtualize those bellow? */
390 tcp_delacktime = TCPTV_DELACK;
391 tcp_keepinit = TCPTV_KEEP_INIT;
392 tcp_keepidle = TCPTV_KEEP_IDLE;
393 tcp_keepintvl = TCPTV_KEEPINTVL;
394 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
395 tcp_msl = TCPTV_MSL;
396 tcp_rexmit_min = TCPTV_MIN;
397 if (tcp_rexmit_min < 1)
398 tcp_rexmit_min = 1;
399 tcp_rexmit_slop = TCPTV_CPU_VAR;
400 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
401 tcp_tcbhashsize = hashsize;
402
403 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
404 if (tcp_soreceive_stream) {
405 #ifdef INET
406 tcp_usrreqs.pru_soreceive = soreceive_stream;
407 #endif
408 #ifdef INET6
409 tcp6_usrreqs.pru_soreceive = soreceive_stream;
410 #endif /* INET6 */
411 }
412
413 #ifdef INET6
414 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
415 #else /* INET6 */
416 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
417 #endif /* INET6 */
418 if (max_protohdr < TCP_MINPROTOHDR)
419 max_protohdr = TCP_MINPROTOHDR;
420 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
421 panic("tcp_init");
422 #undef TCP_MINPROTOHDR
423
424 ISN_LOCK_INIT();
425 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
426 SHUTDOWN_PRI_DEFAULT);
427 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
428 EVENTHANDLER_PRI_ANY);
429 }
430
431 #ifdef VIMAGE
432 void
433 tcp_destroy(void)
434 {
435
436 tcp_hc_destroy();
437 syncache_destroy();
438 tcp_tw_destroy();
439 in_pcbinfo_destroy(&V_tcbinfo);
440 uma_zdestroy(V_sack_hole_zone);
441 uma_zdestroy(V_tcpcb_zone);
442 }
443 #endif
444
445 void
446 tcp_fini(void *xtp)
447 {
448
449 }
450
451 /*
452 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
453 * tcp_template used to store this data in mbufs, but we now recopy it out
454 * of the tcpcb each time to conserve mbufs.
455 */
456 void
457 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
458 {
459 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
460
461 INP_WLOCK_ASSERT(inp);
462
463 #ifdef INET6
464 if ((inp->inp_vflag & INP_IPV6) != 0) {
465 struct ip6_hdr *ip6;
466
467 ip6 = (struct ip6_hdr *)ip_ptr;
468 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
469 (inp->inp_flow & IPV6_FLOWINFO_MASK);
470 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
471 (IPV6_VERSION & IPV6_VERSION_MASK);
472 ip6->ip6_nxt = IPPROTO_TCP;
473 ip6->ip6_plen = htons(sizeof(struct tcphdr));
474 ip6->ip6_src = inp->in6p_laddr;
475 ip6->ip6_dst = inp->in6p_faddr;
476 }
477 #endif /* INET6 */
478 #if defined(INET6) && defined(INET)
479 else
480 #endif
481 #ifdef INET
482 {
483 struct ip *ip;
484
485 ip = (struct ip *)ip_ptr;
486 ip->ip_v = IPVERSION;
487 ip->ip_hl = 5;
488 ip->ip_tos = inp->inp_ip_tos;
489 ip->ip_len = 0;
490 ip->ip_id = 0;
491 ip->ip_off = 0;
492 ip->ip_ttl = inp->inp_ip_ttl;
493 ip->ip_sum = 0;
494 ip->ip_p = IPPROTO_TCP;
495 ip->ip_src = inp->inp_laddr;
496 ip->ip_dst = inp->inp_faddr;
497 }
498 #endif /* INET */
499 th->th_sport = inp->inp_lport;
500 th->th_dport = inp->inp_fport;
501 th->th_seq = 0;
502 th->th_ack = 0;
503 th->th_x2 = 0;
504 th->th_off = 5;
505 th->th_flags = 0;
506 th->th_win = 0;
507 th->th_urp = 0;
508 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
509 }
510
511 /*
512 * Create template to be used to send tcp packets on a connection.
513 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
514 * use for this function is in keepalives, which use tcp_respond.
515 */
516 struct tcptemp *
517 tcpip_maketemplate(struct inpcb *inp)
518 {
519 struct tcptemp *t;
520
521 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
522 if (t == NULL)
523 return (NULL);
524 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
525 return (t);
526 }
527
528 /*
529 * Send a single message to the TCP at address specified by
530 * the given TCP/IP header. If m == NULL, then we make a copy
531 * of the tcpiphdr at ti and send directly to the addressed host.
532 * This is used to force keep alive messages out using the TCP
533 * template for a connection. If flags are given then we send
534 * a message back to the TCP which originated the * segment ti,
535 * and discard the mbuf containing it and any other attached mbufs.
536 *
537 * In any case the ack and sequence number of the transmitted
538 * segment are as specified by the parameters.
539 *
540 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
541 */
542 void
543 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
544 tcp_seq ack, tcp_seq seq, int flags)
545 {
546 int tlen;
547 int win = 0;
548 struct ip *ip;
549 struct tcphdr *nth;
550 #ifdef INET6
551 struct ip6_hdr *ip6;
552 int isipv6;
553 #endif /* INET6 */
554 int ipflags = 0;
555 struct inpcb *inp;
556
557 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
558
559 #ifdef INET6
560 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
561 ip6 = ipgen;
562 #endif /* INET6 */
563 ip = ipgen;
564
565 if (tp != NULL) {
566 inp = tp->t_inpcb;
567 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
568 INP_WLOCK_ASSERT(inp);
569 } else
570 inp = NULL;
571
572 if (tp != NULL) {
573 if (!(flags & TH_RST)) {
574 win = sbspace(&inp->inp_socket->so_rcv);
575 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
576 win = (long)TCP_MAXWIN << tp->rcv_scale;
577 }
578 }
579 if (m == NULL) {
580 m = m_gethdr(M_NOWAIT, MT_DATA);
581 if (m == NULL)
582 return;
583 tlen = 0;
584 m->m_data += max_linkhdr;
585 #ifdef INET6
586 if (isipv6) {
587 bcopy((caddr_t)ip6, mtod(m, caddr_t),
588 sizeof(struct ip6_hdr));
589 ip6 = mtod(m, struct ip6_hdr *);
590 nth = (struct tcphdr *)(ip6 + 1);
591 } else
592 #endif /* INET6 */
593 {
594 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
595 ip = mtod(m, struct ip *);
596 nth = (struct tcphdr *)(ip + 1);
597 }
598 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
599 flags = TH_ACK;
600 } else {
601 /*
602 * reuse the mbuf.
603 * XXX MRT We inherrit the FIB, which is lucky.
604 */
605 m_freem(m->m_next);
606 m->m_next = NULL;
607 m->m_data = (caddr_t)ipgen;
608 /* m_len is set later */
609 tlen = 0;
610 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
611 #ifdef INET6
612 if (isipv6) {
613 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
614 nth = (struct tcphdr *)(ip6 + 1);
615 } else
616 #endif /* INET6 */
617 {
618 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
619 nth = (struct tcphdr *)(ip + 1);
620 }
621 if (th != nth) {
622 /*
623 * this is usually a case when an extension header
624 * exists between the IPv6 header and the
625 * TCP header.
626 */
627 nth->th_sport = th->th_sport;
628 nth->th_dport = th->th_dport;
629 }
630 xchg(nth->th_dport, nth->th_sport, uint16_t);
631 #undef xchg
632 }
633 #ifdef INET6
634 if (isipv6) {
635 ip6->ip6_flow = 0;
636 ip6->ip6_vfc = IPV6_VERSION;
637 ip6->ip6_nxt = IPPROTO_TCP;
638 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
639 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
640 }
641 #endif
642 #if defined(INET) && defined(INET6)
643 else
644 #endif
645 #ifdef INET
646 {
647 tlen += sizeof (struct tcpiphdr);
648 ip->ip_len = htons(tlen);
649 ip->ip_ttl = V_ip_defttl;
650 if (V_path_mtu_discovery)
651 ip->ip_off |= htons(IP_DF);
652 }
653 #endif
654 m->m_len = tlen;
655 m->m_pkthdr.len = tlen;
656 m->m_pkthdr.rcvif = NULL;
657 #ifdef MAC
658 if (inp != NULL) {
659 /*
660 * Packet is associated with a socket, so allow the
661 * label of the response to reflect the socket label.
662 */
663 INP_WLOCK_ASSERT(inp);
664 mac_inpcb_create_mbuf(inp, m);
665 } else {
666 /*
667 * Packet is not associated with a socket, so possibly
668 * update the label in place.
669 */
670 mac_netinet_tcp_reply(m);
671 }
672 #endif
673 nth->th_seq = htonl(seq);
674 nth->th_ack = htonl(ack);
675 nth->th_x2 = 0;
676 nth->th_off = sizeof (struct tcphdr) >> 2;
677 nth->th_flags = flags;
678 if (tp != NULL)
679 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
680 else
681 nth->th_win = htons((u_short)win);
682 nth->th_urp = 0;
683
684 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
685 #ifdef INET6
686 if (isipv6) {
687 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
688 nth->th_sum = in6_cksum_pseudo(ip6,
689 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
690 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
691 NULL, NULL);
692 }
693 #endif /* INET6 */
694 #if defined(INET6) && defined(INET)
695 else
696 #endif
697 #ifdef INET
698 {
699 m->m_pkthdr.csum_flags = CSUM_TCP;
700 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
701 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
702 }
703 #endif /* INET */
704 #ifdef TCPDEBUG
705 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
706 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
707 #endif
708 if (flags & TH_RST)
709 TCP_PROBE5(accept__refused, NULL, NULL, mtod(m, const char *),
710 tp, nth);
711
712 TCP_PROBE5(send, NULL, tp, mtod(m, const char *), tp, nth);
713 #ifdef INET6
714 if (isipv6)
715 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
716 #endif /* INET6 */
717 #if defined(INET) && defined(INET6)
718 else
719 #endif
720 #ifdef INET
721 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
722 #endif
723 }
724
725 /*
726 * Create a new TCP control block, making an
727 * empty reassembly queue and hooking it to the argument
728 * protocol control block. The `inp' parameter must have
729 * come from the zone allocator set up in tcp_init().
730 */
731 struct tcpcb *
732 tcp_newtcpcb(struct inpcb *inp)
733 {
734 struct tcpcb_mem *tm;
735 struct tcpcb *tp;
736 #ifdef INET6
737 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
738 #endif /* INET6 */
739
740 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
741 if (tm == NULL)
742 return (NULL);
743 tp = &tm->tcb;
744
745 /* Initialise cc_var struct for this tcpcb. */
746 tp->ccv = &tm->ccv;
747 tp->ccv->type = IPPROTO_TCP;
748 tp->ccv->ccvc.tcp = tp;
749
750 /*
751 * Use the current system default CC algorithm.
752 */
753 CC_LIST_RLOCK();
754 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
755 CC_ALGO(tp) = CC_DEFAULT();
756 CC_LIST_RUNLOCK();
757
758 if (CC_ALGO(tp)->cb_init != NULL)
759 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
760 uma_zfree(V_tcpcb_zone, tm);
761 return (NULL);
762 }
763
764 tp->osd = &tm->osd;
765 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
766 uma_zfree(V_tcpcb_zone, tm);
767 return (NULL);
768 }
769
770 #ifdef VIMAGE
771 tp->t_vnet = inp->inp_vnet;
772 #endif
773 tp->t_timers = &tm->tt;
774 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
775 tp->t_maxseg = tp->t_maxopd =
776 #ifdef INET6
777 isipv6 ? V_tcp_v6mssdflt :
778 #endif /* INET6 */
779 V_tcp_mssdflt;
780
781 /* Set up our timeouts. */
782 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
783 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
784 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
785 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
786 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
787
788 if (V_tcp_do_rfc1323)
789 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
790 if (V_tcp_do_sack)
791 tp->t_flags |= TF_SACK_PERMIT;
792 TAILQ_INIT(&tp->snd_holes);
793 tp->t_inpcb = inp; /* XXX */
794 /*
795 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
796 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
797 * reasonable initial retransmit time.
798 */
799 tp->t_srtt = TCPTV_SRTTBASE;
800 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
801 tp->t_rttmin = tcp_rexmit_min;
802 tp->t_rxtcur = TCPTV_RTOBASE;
803 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
804 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
805 tp->t_rcvtime = ticks;
806 /*
807 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
808 * because the socket may be bound to an IPv6 wildcard address,
809 * which may match an IPv4-mapped IPv6 address.
810 */
811 inp->inp_ip_ttl = V_ip_defttl;
812 inp->inp_ppcb = tp;
813 return (tp); /* XXX */
814 }
815
816 /*
817 * Switch the congestion control algorithm back to NewReno for any active
818 * control blocks using an algorithm which is about to go away.
819 * This ensures the CC framework can allow the unload to proceed without leaving
820 * any dangling pointers which would trigger a panic.
821 * Returning non-zero would inform the CC framework that something went wrong
822 * and it would be unsafe to allow the unload to proceed. However, there is no
823 * way for this to occur with this implementation so we always return zero.
824 */
825 int
826 tcp_ccalgounload(struct cc_algo *unload_algo)
827 {
828 struct cc_algo *tmpalgo;
829 struct inpcb *inp;
830 struct tcpcb *tp;
831 VNET_ITERATOR_DECL(vnet_iter);
832
833 /*
834 * Check all active control blocks across all network stacks and change
835 * any that are using "unload_algo" back to NewReno. If "unload_algo"
836 * requires cleanup code to be run, call it.
837 */
838 VNET_LIST_RLOCK();
839 VNET_FOREACH(vnet_iter) {
840 CURVNET_SET(vnet_iter);
841 INP_INFO_RLOCK(&V_tcbinfo);
842 /*
843 * New connections already part way through being initialised
844 * with the CC algo we're removing will not race with this code
845 * because the INP_INFO_WLOCK is held during initialisation. We
846 * therefore don't enter the loop below until the connection
847 * list has stabilised.
848 */
849 LIST_FOREACH(inp, &V_tcb, inp_list) {
850 INP_WLOCK(inp);
851 /* Important to skip tcptw structs. */
852 if (!(inp->inp_flags & INP_TIMEWAIT) &&
853 (tp = intotcpcb(inp)) != NULL) {
854 /*
855 * By holding INP_WLOCK here, we are assured
856 * that the connection is not currently
857 * executing inside the CC module's functions
858 * i.e. it is safe to make the switch back to
859 * NewReno.
860 */
861 if (CC_ALGO(tp) == unload_algo) {
862 tmpalgo = CC_ALGO(tp);
863 /* NewReno does not require any init. */
864 CC_ALGO(tp) = &newreno_cc_algo;
865 if (tmpalgo->cb_destroy != NULL)
866 tmpalgo->cb_destroy(tp->ccv);
867 }
868 }
869 INP_WUNLOCK(inp);
870 }
871 INP_INFO_RUNLOCK(&V_tcbinfo);
872 CURVNET_RESTORE();
873 }
874 VNET_LIST_RUNLOCK();
875
876 return (0);
877 }
878
879 /*
880 * Drop a TCP connection, reporting
881 * the specified error. If connection is synchronized,
882 * then send a RST to peer.
883 */
884 struct tcpcb *
885 tcp_drop(struct tcpcb *tp, int errno)
886 {
887 struct socket *so = tp->t_inpcb->inp_socket;
888
889 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
890 INP_WLOCK_ASSERT(tp->t_inpcb);
891
892 if (TCPS_HAVERCVDSYN(tp->t_state)) {
893 tcp_state_change(tp, TCPS_CLOSED);
894 (void) tcp_output(tp);
895 TCPSTAT_INC(tcps_drops);
896 } else
897 TCPSTAT_INC(tcps_conndrops);
898 if (errno == ETIMEDOUT && tp->t_softerror)
899 errno = tp->t_softerror;
900 so->so_error = errno;
901 return (tcp_close(tp));
902 }
903
904 void
905 tcp_discardcb(struct tcpcb *tp)
906 {
907 struct inpcb *inp = tp->t_inpcb;
908 struct socket *so = inp->inp_socket;
909 #ifdef INET6
910 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
911 #endif /* INET6 */
912
913 INP_WLOCK_ASSERT(inp);
914
915 /*
916 * Make sure that all of our timers are stopped before we delete the
917 * PCB.
918 *
919 * XXXRW: Really, we would like to use callout_drain() here in order
920 * to avoid races experienced in tcp_timer.c where a timer is already
921 * executing at this point. However, we can't, both because we're
922 * running in a context where we can't sleep, and also because we
923 * hold locks required by the timers. What we instead need to do is
924 * test to see if callout_drain() is required, and if so, defer some
925 * portion of the remainder of tcp_discardcb() to an asynchronous
926 * context that can callout_drain() and then continue. Some care
927 * will be required to ensure that no further processing takes place
928 * on the tcpcb, even though it hasn't been freed (a flag?).
929 */
930 callout_stop(&tp->t_timers->tt_rexmt);
931 callout_stop(&tp->t_timers->tt_persist);
932 callout_stop(&tp->t_timers->tt_keep);
933 callout_stop(&tp->t_timers->tt_2msl);
934 callout_stop(&tp->t_timers->tt_delack);
935
936 /*
937 * If we got enough samples through the srtt filter,
938 * save the rtt and rttvar in the routing entry.
939 * 'Enough' is arbitrarily defined as 4 rtt samples.
940 * 4 samples is enough for the srtt filter to converge
941 * to within enough % of the correct value; fewer samples
942 * and we could save a bogus rtt. The danger is not high
943 * as tcp quickly recovers from everything.
944 * XXX: Works very well but needs some more statistics!
945 */
946 if (tp->t_rttupdated >= 4) {
947 struct hc_metrics_lite metrics;
948 u_long ssthresh;
949
950 bzero(&metrics, sizeof(metrics));
951 /*
952 * Update the ssthresh always when the conditions below
953 * are satisfied. This gives us better new start value
954 * for the congestion avoidance for new connections.
955 * ssthresh is only set if packet loss occured on a session.
956 *
957 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
958 * being torn down. Ideally this code would not use 'so'.
959 */
960 ssthresh = tp->snd_ssthresh;
961 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
962 /*
963 * convert the limit from user data bytes to
964 * packets then to packet data bytes.
965 */
966 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
967 if (ssthresh < 2)
968 ssthresh = 2;
969 ssthresh *= (u_long)(tp->t_maxseg +
970 #ifdef INET6
971 (isipv6 ? sizeof (struct ip6_hdr) +
972 sizeof (struct tcphdr) :
973 #endif
974 sizeof (struct tcpiphdr)
975 #ifdef INET6
976 )
977 #endif
978 );
979 } else
980 ssthresh = 0;
981 metrics.rmx_ssthresh = ssthresh;
982
983 metrics.rmx_rtt = tp->t_srtt;
984 metrics.rmx_rttvar = tp->t_rttvar;
985 metrics.rmx_cwnd = tp->snd_cwnd;
986 metrics.rmx_sendpipe = 0;
987 metrics.rmx_recvpipe = 0;
988
989 tcp_hc_update(&inp->inp_inc, &metrics);
990 }
991
992 /* free the reassembly queue, if any */
993 tcp_reass_flush(tp);
994
995 #ifdef TCP_OFFLOAD
996 /* Disconnect offload device, if any. */
997 if (tp->t_flags & TF_TOE)
998 tcp_offload_detach(tp);
999 #endif
1000
1001 tcp_free_sackholes(tp);
1002
1003 /* Allow the CC algorithm to clean up after itself. */
1004 if (CC_ALGO(tp)->cb_destroy != NULL)
1005 CC_ALGO(tp)->cb_destroy(tp->ccv);
1006
1007 khelp_destroy_osd(tp->osd);
1008
1009 CC_ALGO(tp) = NULL;
1010 inp->inp_ppcb = NULL;
1011 tp->t_inpcb = NULL;
1012 uma_zfree(V_tcpcb_zone, tp);
1013 }
1014
1015 /*
1016 * Attempt to close a TCP control block, marking it as dropped, and freeing
1017 * the socket if we hold the only reference.
1018 */
1019 struct tcpcb *
1020 tcp_close(struct tcpcb *tp)
1021 {
1022 struct inpcb *inp = tp->t_inpcb;
1023 struct socket *so;
1024
1025 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1026 INP_WLOCK_ASSERT(inp);
1027
1028 #ifdef TCP_OFFLOAD
1029 if (tp->t_state == TCPS_LISTEN)
1030 tcp_offload_listen_stop(tp);
1031 #endif
1032 in_pcbdrop(inp);
1033 TCPSTAT_INC(tcps_closed);
1034 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1035 so = inp->inp_socket;
1036 soisdisconnected(so);
1037 if (inp->inp_flags & INP_SOCKREF) {
1038 KASSERT(so->so_state & SS_PROTOREF,
1039 ("tcp_close: !SS_PROTOREF"));
1040 inp->inp_flags &= ~INP_SOCKREF;
1041 INP_WUNLOCK(inp);
1042 ACCEPT_LOCK();
1043 SOCK_LOCK(so);
1044 so->so_state &= ~SS_PROTOREF;
1045 sofree(so);
1046 return (NULL);
1047 }
1048 return (tp);
1049 }
1050
1051 void
1052 tcp_drain(void)
1053 {
1054 VNET_ITERATOR_DECL(vnet_iter);
1055
1056 if (!do_tcpdrain)
1057 return;
1058
1059 VNET_LIST_RLOCK_NOSLEEP();
1060 VNET_FOREACH(vnet_iter) {
1061 CURVNET_SET(vnet_iter);
1062 struct inpcb *inpb;
1063 struct tcpcb *tcpb;
1064
1065 /*
1066 * Walk the tcpbs, if existing, and flush the reassembly queue,
1067 * if there is one...
1068 * XXX: The "Net/3" implementation doesn't imply that the TCP
1069 * reassembly queue should be flushed, but in a situation
1070 * where we're really low on mbufs, this is potentially
1071 * useful.
1072 */
1073 INP_INFO_RLOCK(&V_tcbinfo);
1074 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1075 if (inpb->inp_flags & INP_TIMEWAIT)
1076 continue;
1077 INP_WLOCK(inpb);
1078 if ((tcpb = intotcpcb(inpb)) != NULL) {
1079 tcp_reass_flush(tcpb);
1080 tcp_clean_sackreport(tcpb);
1081 }
1082 INP_WUNLOCK(inpb);
1083 }
1084 INP_INFO_RUNLOCK(&V_tcbinfo);
1085 CURVNET_RESTORE();
1086 }
1087 VNET_LIST_RUNLOCK_NOSLEEP();
1088 }
1089
1090 /*
1091 * Notify a tcp user of an asynchronous error;
1092 * store error as soft error, but wake up user
1093 * (for now, won't do anything until can select for soft error).
1094 *
1095 * Do not wake up user since there currently is no mechanism for
1096 * reporting soft errors (yet - a kqueue filter may be added).
1097 */
1098 static struct inpcb *
1099 tcp_notify(struct inpcb *inp, int error)
1100 {
1101 struct tcpcb *tp;
1102
1103 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1104 INP_WLOCK_ASSERT(inp);
1105
1106 if ((inp->inp_flags & INP_TIMEWAIT) ||
1107 (inp->inp_flags & INP_DROPPED))
1108 return (inp);
1109
1110 tp = intotcpcb(inp);
1111 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1112
1113 /*
1114 * Ignore some errors if we are hooked up.
1115 * If connection hasn't completed, has retransmitted several times,
1116 * and receives a second error, give up now. This is better
1117 * than waiting a long time to establish a connection that
1118 * can never complete.
1119 */
1120 if (tp->t_state == TCPS_ESTABLISHED &&
1121 (error == EHOSTUNREACH || error == ENETUNREACH ||
1122 error == EHOSTDOWN)) {
1123 return (inp);
1124 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1125 tp->t_softerror) {
1126 tp = tcp_drop(tp, error);
1127 if (tp != NULL)
1128 return (inp);
1129 else
1130 return (NULL);
1131 } else {
1132 tp->t_softerror = error;
1133 return (inp);
1134 }
1135 #if 0
1136 wakeup( &so->so_timeo);
1137 sorwakeup(so);
1138 sowwakeup(so);
1139 #endif
1140 }
1141
1142 static int
1143 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1144 {
1145 int error, i, m, n, pcb_count;
1146 struct inpcb *inp, **inp_list;
1147 inp_gen_t gencnt;
1148 struct xinpgen xig;
1149
1150 /*
1151 * The process of preparing the TCB list is too time-consuming and
1152 * resource-intensive to repeat twice on every request.
1153 */
1154 if (req->oldptr == NULL) {
1155 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1156 n += imax(n / 8, 10);
1157 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1158 return (0);
1159 }
1160
1161 if (req->newptr != NULL)
1162 return (EPERM);
1163
1164 /*
1165 * OK, now we're committed to doing something.
1166 */
1167 INP_INFO_RLOCK(&V_tcbinfo);
1168 gencnt = V_tcbinfo.ipi_gencnt;
1169 n = V_tcbinfo.ipi_count;
1170 INP_INFO_RUNLOCK(&V_tcbinfo);
1171
1172 m = syncache_pcbcount();
1173
1174 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1175 + (n + m) * sizeof(struct xtcpcb));
1176 if (error != 0)
1177 return (error);
1178
1179 xig.xig_len = sizeof xig;
1180 xig.xig_count = n + m;
1181 xig.xig_gen = gencnt;
1182 xig.xig_sogen = so_gencnt;
1183 error = SYSCTL_OUT(req, &xig, sizeof xig);
1184 if (error)
1185 return (error);
1186
1187 error = syncache_pcblist(req, m, &pcb_count);
1188 if (error)
1189 return (error);
1190
1191 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1192 if (inp_list == NULL)
1193 return (ENOMEM);
1194
1195 INP_INFO_RLOCK(&V_tcbinfo);
1196 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1197 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1198 INP_WLOCK(inp);
1199 if (inp->inp_gencnt <= gencnt) {
1200 /*
1201 * XXX: This use of cr_cansee(), introduced with
1202 * TCP state changes, is not quite right, but for
1203 * now, better than nothing.
1204 */
1205 if (inp->inp_flags & INP_TIMEWAIT) {
1206 if (intotw(inp) != NULL)
1207 error = cr_cansee(req->td->td_ucred,
1208 intotw(inp)->tw_cred);
1209 else
1210 error = EINVAL; /* Skip this inp. */
1211 } else
1212 error = cr_canseeinpcb(req->td->td_ucred, inp);
1213 if (error == 0) {
1214 in_pcbref(inp);
1215 inp_list[i++] = inp;
1216 }
1217 }
1218 INP_WUNLOCK(inp);
1219 }
1220 INP_INFO_RUNLOCK(&V_tcbinfo);
1221 n = i;
1222
1223 error = 0;
1224 for (i = 0; i < n; i++) {
1225 inp = inp_list[i];
1226 INP_RLOCK(inp);
1227 if (inp->inp_gencnt <= gencnt) {
1228 struct xtcpcb xt;
1229 void *inp_ppcb;
1230
1231 bzero(&xt, sizeof(xt));
1232 xt.xt_len = sizeof xt;
1233 /* XXX should avoid extra copy */
1234 bcopy(inp, &xt.xt_inp, sizeof *inp);
1235 inp_ppcb = inp->inp_ppcb;
1236 if (inp_ppcb == NULL)
1237 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1238 else if (inp->inp_flags & INP_TIMEWAIT) {
1239 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1240 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1241 } else {
1242 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1243 if (xt.xt_tp.t_timers)
1244 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1245 }
1246 if (inp->inp_socket != NULL)
1247 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1248 else {
1249 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1250 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1251 }
1252 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1253 INP_RUNLOCK(inp);
1254 error = SYSCTL_OUT(req, &xt, sizeof xt);
1255 } else
1256 INP_RUNLOCK(inp);
1257 }
1258 INP_INFO_WLOCK(&V_tcbinfo);
1259 for (i = 0; i < n; i++) {
1260 inp = inp_list[i];
1261 INP_RLOCK(inp);
1262 if (!in_pcbrele_rlocked(inp))
1263 INP_RUNLOCK(inp);
1264 }
1265 INP_INFO_WUNLOCK(&V_tcbinfo);
1266
1267 if (!error) {
1268 /*
1269 * Give the user an updated idea of our state.
1270 * If the generation differs from what we told
1271 * her before, she knows that something happened
1272 * while we were processing this request, and it
1273 * might be necessary to retry.
1274 */
1275 INP_INFO_RLOCK(&V_tcbinfo);
1276 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1277 xig.xig_sogen = so_gencnt;
1278 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1279 INP_INFO_RUNLOCK(&V_tcbinfo);
1280 error = SYSCTL_OUT(req, &xig, sizeof xig);
1281 }
1282 free(inp_list, M_TEMP);
1283 return (error);
1284 }
1285
1286 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1287 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1288 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1289
1290 #ifdef INET
1291 static int
1292 tcp_getcred(SYSCTL_HANDLER_ARGS)
1293 {
1294 struct xucred xuc;
1295 struct sockaddr_in addrs[2];
1296 struct inpcb *inp;
1297 int error;
1298
1299 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1300 if (error)
1301 return (error);
1302 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1303 if (error)
1304 return (error);
1305 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1306 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1307 if (inp != NULL) {
1308 if (inp->inp_socket == NULL)
1309 error = ENOENT;
1310 if (error == 0)
1311 error = cr_canseeinpcb(req->td->td_ucred, inp);
1312 if (error == 0)
1313 cru2x(inp->inp_cred, &xuc);
1314 INP_RUNLOCK(inp);
1315 } else
1316 error = ENOENT;
1317 if (error == 0)
1318 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1319 return (error);
1320 }
1321
1322 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1323 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1324 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1325 #endif /* INET */
1326
1327 #ifdef INET6
1328 static int
1329 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1330 {
1331 struct xucred xuc;
1332 struct sockaddr_in6 addrs[2];
1333 struct inpcb *inp;
1334 int error;
1335 #ifdef INET
1336 int mapped = 0;
1337 #endif
1338
1339 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1340 if (error)
1341 return (error);
1342 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1343 if (error)
1344 return (error);
1345 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1346 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1347 return (error);
1348 }
1349 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1350 #ifdef INET
1351 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1352 mapped = 1;
1353 else
1354 #endif
1355 return (EINVAL);
1356 }
1357
1358 #ifdef INET
1359 if (mapped == 1)
1360 inp = in_pcblookup(&V_tcbinfo,
1361 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1362 addrs[1].sin6_port,
1363 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1364 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1365 else
1366 #endif
1367 inp = in6_pcblookup(&V_tcbinfo,
1368 &addrs[1].sin6_addr, addrs[1].sin6_port,
1369 &addrs[0].sin6_addr, addrs[0].sin6_port,
1370 INPLOOKUP_RLOCKPCB, NULL);
1371 if (inp != NULL) {
1372 if (inp->inp_socket == NULL)
1373 error = ENOENT;
1374 if (error == 0)
1375 error = cr_canseeinpcb(req->td->td_ucred, inp);
1376 if (error == 0)
1377 cru2x(inp->inp_cred, &xuc);
1378 INP_RUNLOCK(inp);
1379 } else
1380 error = ENOENT;
1381 if (error == 0)
1382 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1383 return (error);
1384 }
1385
1386 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1387 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1388 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1389 #endif /* INET6 */
1390
1391
1392 #ifdef INET
1393 void
1394 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1395 {
1396 struct ip *ip = vip;
1397 struct tcphdr *th;
1398 struct in_addr faddr;
1399 struct inpcb *inp;
1400 struct tcpcb *tp;
1401 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1402 struct icmp *icp;
1403 struct in_conninfo inc;
1404 tcp_seq icmp_tcp_seq;
1405 int mtu;
1406
1407 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1408 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1409 return;
1410
1411 if (cmd == PRC_MSGSIZE)
1412 notify = tcp_mtudisc_notify;
1413 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1414 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1415 notify = tcp_drop_syn_sent;
1416 /*
1417 * Redirects don't need to be handled up here.
1418 */
1419 else if (PRC_IS_REDIRECT(cmd))
1420 return;
1421 /*
1422 * Source quench is depreciated.
1423 */
1424 else if (cmd == PRC_QUENCH)
1425 return;
1426 /*
1427 * Hostdead is ugly because it goes linearly through all PCBs.
1428 * XXX: We never get this from ICMP, otherwise it makes an
1429 * excellent DoS attack on machines with many connections.
1430 */
1431 else if (cmd == PRC_HOSTDEAD)
1432 ip = NULL;
1433 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1434 return;
1435 if (ip != NULL) {
1436 icp = (struct icmp *)((caddr_t)ip
1437 - offsetof(struct icmp, icmp_ip));
1438 th = (struct tcphdr *)((caddr_t)ip
1439 + (ip->ip_hl << 2));
1440 INP_INFO_WLOCK(&V_tcbinfo);
1441 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1442 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1443 if (inp != NULL) {
1444 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1445 !(inp->inp_flags & INP_DROPPED) &&
1446 !(inp->inp_socket == NULL)) {
1447 icmp_tcp_seq = htonl(th->th_seq);
1448 tp = intotcpcb(inp);
1449 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1450 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1451 if (cmd == PRC_MSGSIZE) {
1452 /*
1453 * MTU discovery:
1454 * If we got a needfrag set the MTU
1455 * in the route to the suggested new
1456 * value (if given) and then notify.
1457 */
1458 bzero(&inc, sizeof(inc));
1459 inc.inc_faddr = faddr;
1460 inc.inc_fibnum =
1461 inp->inp_inc.inc_fibnum;
1462
1463 mtu = ntohs(icp->icmp_nextmtu);
1464 /*
1465 * If no alternative MTU was
1466 * proposed, try the next smaller
1467 * one.
1468 */
1469 if (!mtu)
1470 mtu = ip_next_mtu(
1471 ntohs(ip->ip_len), 1);
1472 if (mtu < V_tcp_minmss
1473 + sizeof(struct tcpiphdr))
1474 mtu = V_tcp_minmss
1475 + sizeof(struct tcpiphdr);
1476 /*
1477 * Only cache the MTU if it
1478 * is smaller than the interface
1479 * or route MTU. tcp_mtudisc()
1480 * will do right thing by itself.
1481 */
1482 if (mtu <= tcp_maxmtu(&inc, NULL))
1483 tcp_hc_updatemtu(&inc, mtu);
1484 tcp_mtudisc(inp, mtu);
1485 } else
1486 inp = (*notify)(inp,
1487 inetctlerrmap[cmd]);
1488 }
1489 }
1490 if (inp != NULL)
1491 INP_WUNLOCK(inp);
1492 } else {
1493 bzero(&inc, sizeof(inc));
1494 inc.inc_fport = th->th_dport;
1495 inc.inc_lport = th->th_sport;
1496 inc.inc_faddr = faddr;
1497 inc.inc_laddr = ip->ip_src;
1498 syncache_unreach(&inc, th);
1499 }
1500 INP_INFO_WUNLOCK(&V_tcbinfo);
1501 } else
1502 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1503 }
1504 #endif /* INET */
1505
1506 #ifdef INET6
1507 void
1508 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1509 {
1510 struct tcphdr th;
1511 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1512 struct ip6_hdr *ip6;
1513 struct mbuf *m;
1514 struct ip6ctlparam *ip6cp = NULL;
1515 const struct sockaddr_in6 *sa6_src = NULL;
1516 int off;
1517 struct tcp_portonly {
1518 u_int16_t th_sport;
1519 u_int16_t th_dport;
1520 } *thp;
1521
1522 if (sa->sa_family != AF_INET6 ||
1523 sa->sa_len != sizeof(struct sockaddr_in6))
1524 return;
1525
1526 if (cmd == PRC_MSGSIZE)
1527 notify = tcp_mtudisc_notify;
1528 else if (!PRC_IS_REDIRECT(cmd) &&
1529 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1530 return;
1531 /* Source quench is depreciated. */
1532 else if (cmd == PRC_QUENCH)
1533 return;
1534
1535 /* if the parameter is from icmp6, decode it. */
1536 if (d != NULL) {
1537 ip6cp = (struct ip6ctlparam *)d;
1538 m = ip6cp->ip6c_m;
1539 ip6 = ip6cp->ip6c_ip6;
1540 off = ip6cp->ip6c_off;
1541 sa6_src = ip6cp->ip6c_src;
1542 } else {
1543 m = NULL;
1544 ip6 = NULL;
1545 off = 0; /* fool gcc */
1546 sa6_src = &sa6_any;
1547 }
1548
1549 if (ip6 != NULL) {
1550 struct in_conninfo inc;
1551 /*
1552 * XXX: We assume that when IPV6 is non NULL,
1553 * M and OFF are valid.
1554 */
1555
1556 /* check if we can safely examine src and dst ports */
1557 if (m->m_pkthdr.len < off + sizeof(*thp))
1558 return;
1559
1560 bzero(&th, sizeof(th));
1561 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1562
1563 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1564 (struct sockaddr *)ip6cp->ip6c_src,
1565 th.th_sport, cmd, NULL, notify);
1566
1567 bzero(&inc, sizeof(inc));
1568 inc.inc_fport = th.th_dport;
1569 inc.inc_lport = th.th_sport;
1570 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1571 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1572 inc.inc_flags |= INC_ISIPV6;
1573 INP_INFO_WLOCK(&V_tcbinfo);
1574 syncache_unreach(&inc, &th);
1575 INP_INFO_WUNLOCK(&V_tcbinfo);
1576 } else
1577 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1578 0, cmd, NULL, notify);
1579 }
1580 #endif /* INET6 */
1581
1582
1583 /*
1584 * Following is where TCP initial sequence number generation occurs.
1585 *
1586 * There are two places where we must use initial sequence numbers:
1587 * 1. In SYN-ACK packets.
1588 * 2. In SYN packets.
1589 *
1590 * All ISNs for SYN-ACK packets are generated by the syncache. See
1591 * tcp_syncache.c for details.
1592 *
1593 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1594 * depends on this property. In addition, these ISNs should be
1595 * unguessable so as to prevent connection hijacking. To satisfy
1596 * the requirements of this situation, the algorithm outlined in
1597 * RFC 1948 is used, with only small modifications.
1598 *
1599 * Implementation details:
1600 *
1601 * Time is based off the system timer, and is corrected so that it
1602 * increases by one megabyte per second. This allows for proper
1603 * recycling on high speed LANs while still leaving over an hour
1604 * before rollover.
1605 *
1606 * As reading the *exact* system time is too expensive to be done
1607 * whenever setting up a TCP connection, we increment the time
1608 * offset in two ways. First, a small random positive increment
1609 * is added to isn_offset for each connection that is set up.
1610 * Second, the function tcp_isn_tick fires once per clock tick
1611 * and increments isn_offset as necessary so that sequence numbers
1612 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1613 * random positive increments serve only to ensure that the same
1614 * exact sequence number is never sent out twice (as could otherwise
1615 * happen when a port is recycled in less than the system tick
1616 * interval.)
1617 *
1618 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1619 * between seeding of isn_secret. This is normally set to zero,
1620 * as reseeding should not be necessary.
1621 *
1622 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1623 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1624 * general, this means holding an exclusive (write) lock.
1625 */
1626
1627 #define ISN_BYTES_PER_SECOND 1048576
1628 #define ISN_STATIC_INCREMENT 4096
1629 #define ISN_RANDOM_INCREMENT (4096 - 1)
1630
1631 static VNET_DEFINE(u_char, isn_secret[32]);
1632 static VNET_DEFINE(int, isn_last);
1633 static VNET_DEFINE(int, isn_last_reseed);
1634 static VNET_DEFINE(u_int32_t, isn_offset);
1635 static VNET_DEFINE(u_int32_t, isn_offset_old);
1636
1637 #define V_isn_secret VNET(isn_secret)
1638 #define V_isn_last VNET(isn_last)
1639 #define V_isn_last_reseed VNET(isn_last_reseed)
1640 #define V_isn_offset VNET(isn_offset)
1641 #define V_isn_offset_old VNET(isn_offset_old)
1642
1643 tcp_seq
1644 tcp_new_isn(struct tcpcb *tp)
1645 {
1646 MD5_CTX isn_ctx;
1647 u_int32_t md5_buffer[4];
1648 tcp_seq new_isn;
1649 u_int32_t projected_offset;
1650
1651 INP_WLOCK_ASSERT(tp->t_inpcb);
1652
1653 ISN_LOCK();
1654 /* Seed if this is the first use, reseed if requested. */
1655 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1656 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1657 < (u_int)ticks))) {
1658 read_random(&V_isn_secret, sizeof(V_isn_secret));
1659 V_isn_last_reseed = ticks;
1660 }
1661
1662 /* Compute the md5 hash and return the ISN. */
1663 MD5Init(&isn_ctx);
1664 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1665 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1666 #ifdef INET6
1667 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1669 sizeof(struct in6_addr));
1670 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1671 sizeof(struct in6_addr));
1672 } else
1673 #endif
1674 {
1675 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1676 sizeof(struct in_addr));
1677 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1678 sizeof(struct in_addr));
1679 }
1680 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1681 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1682 new_isn = (tcp_seq) md5_buffer[0];
1683 V_isn_offset += ISN_STATIC_INCREMENT +
1684 (arc4random() & ISN_RANDOM_INCREMENT);
1685 if (ticks != V_isn_last) {
1686 projected_offset = V_isn_offset_old +
1687 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1688 if (SEQ_GT(projected_offset, V_isn_offset))
1689 V_isn_offset = projected_offset;
1690 V_isn_offset_old = V_isn_offset;
1691 V_isn_last = ticks;
1692 }
1693 new_isn += V_isn_offset;
1694 ISN_UNLOCK();
1695 return (new_isn);
1696 }
1697
1698 /*
1699 * When a specific ICMP unreachable message is received and the
1700 * connection state is SYN-SENT, drop the connection. This behavior
1701 * is controlled by the icmp_may_rst sysctl.
1702 */
1703 struct inpcb *
1704 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1705 {
1706 struct tcpcb *tp;
1707
1708 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1709 INP_WLOCK_ASSERT(inp);
1710
1711 if ((inp->inp_flags & INP_TIMEWAIT) ||
1712 (inp->inp_flags & INP_DROPPED))
1713 return (inp);
1714
1715 tp = intotcpcb(inp);
1716 if (tp->t_state != TCPS_SYN_SENT)
1717 return (inp);
1718
1719 tp = tcp_drop(tp, errno);
1720 if (tp != NULL)
1721 return (inp);
1722 else
1723 return (NULL);
1724 }
1725
1726 /*
1727 * When `need fragmentation' ICMP is received, update our idea of the MSS
1728 * based on the new value. Also nudge TCP to send something, since we
1729 * know the packet we just sent was dropped.
1730 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1731 */
1732 static struct inpcb *
1733 tcp_mtudisc_notify(struct inpcb *inp, int error)
1734 {
1735
1736 return (tcp_mtudisc(inp, -1));
1737 }
1738
1739 struct inpcb *
1740 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1741 {
1742 struct tcpcb *tp;
1743 struct socket *so;
1744
1745 INP_WLOCK_ASSERT(inp);
1746 if ((inp->inp_flags & INP_TIMEWAIT) ||
1747 (inp->inp_flags & INP_DROPPED))
1748 return (inp);
1749
1750 tp = intotcpcb(inp);
1751 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1752
1753 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1754
1755 so = inp->inp_socket;
1756 SOCKBUF_LOCK(&so->so_snd);
1757 /* If the mss is larger than the socket buffer, decrease the mss. */
1758 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1759 tp->t_maxseg = so->so_snd.sb_hiwat;
1760 SOCKBUF_UNLOCK(&so->so_snd);
1761
1762 TCPSTAT_INC(tcps_mturesent);
1763 tp->t_rtttime = 0;
1764 tp->snd_nxt = tp->snd_una;
1765 tcp_free_sackholes(tp);
1766 tp->snd_recover = tp->snd_max;
1767 if (tp->t_flags & TF_SACK_PERMIT)
1768 EXIT_FASTRECOVERY(tp->t_flags);
1769 tcp_output(tp);
1770 return (inp);
1771 }
1772
1773 #ifdef INET
1774 /*
1775 * Look-up the routing entry to the peer of this inpcb. If no route
1776 * is found and it cannot be allocated, then return 0. This routine
1777 * is called by TCP routines that access the rmx structure and by
1778 * tcp_mss_update to get the peer/interface MTU.
1779 */
1780 u_long
1781 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1782 {
1783 struct route sro;
1784 struct sockaddr_in *dst;
1785 struct ifnet *ifp;
1786 u_long maxmtu = 0;
1787
1788 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1789
1790 bzero(&sro, sizeof(sro));
1791 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1792 dst = (struct sockaddr_in *)&sro.ro_dst;
1793 dst->sin_family = AF_INET;
1794 dst->sin_len = sizeof(*dst);
1795 dst->sin_addr = inc->inc_faddr;
1796 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1797 }
1798 if (sro.ro_rt != NULL) {
1799 ifp = sro.ro_rt->rt_ifp;
1800 if (sro.ro_rt->rt_mtu == 0)
1801 maxmtu = ifp->if_mtu;
1802 else
1803 maxmtu = min(sro.ro_rt->rt_mtu, ifp->if_mtu);
1804
1805 /* Report additional interface capabilities. */
1806 if (cap != NULL) {
1807 if (ifp->if_capenable & IFCAP_TSO4 &&
1808 ifp->if_hwassist & CSUM_TSO) {
1809 cap->ifcap |= CSUM_TSO;
1810 cap->tsomax = ifp->if_hw_tsomax;
1811 }
1812 }
1813 RTFREE(sro.ro_rt);
1814 }
1815 return (maxmtu);
1816 }
1817 #endif /* INET */
1818
1819 #ifdef INET6
1820 u_long
1821 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1822 {
1823 struct route_in6 sro6;
1824 struct ifnet *ifp;
1825 u_long maxmtu = 0;
1826
1827 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1828
1829 bzero(&sro6, sizeof(sro6));
1830 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1831 sro6.ro_dst.sin6_family = AF_INET6;
1832 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1833 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1834 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1835 }
1836 if (sro6.ro_rt != NULL) {
1837 ifp = sro6.ro_rt->rt_ifp;
1838 if (sro6.ro_rt->rt_mtu == 0)
1839 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1840 else
1841 maxmtu = min(sro6.ro_rt->rt_mtu,
1842 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1843
1844 /* Report additional interface capabilities. */
1845 if (cap != NULL) {
1846 if (ifp->if_capenable & IFCAP_TSO6 &&
1847 ifp->if_hwassist & CSUM_TSO) {
1848 cap->ifcap |= CSUM_TSO;
1849 cap->tsomax = ifp->if_hw_tsomax;
1850 }
1851 }
1852 RTFREE(sro6.ro_rt);
1853 }
1854
1855 return (maxmtu);
1856 }
1857 #endif /* INET6 */
1858
1859 #ifdef IPSEC
1860 /* compute ESP/AH header size for TCP, including outer IP header. */
1861 size_t
1862 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1863 {
1864 struct inpcb *inp;
1865 struct mbuf *m;
1866 size_t hdrsiz;
1867 struct ip *ip;
1868 #ifdef INET6
1869 struct ip6_hdr *ip6;
1870 #endif
1871 struct tcphdr *th;
1872
1873 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1874 return (0);
1875 m = m_gethdr(M_NOWAIT, MT_DATA);
1876 if (!m)
1877 return (0);
1878
1879 #ifdef INET6
1880 if ((inp->inp_vflag & INP_IPV6) != 0) {
1881 ip6 = mtod(m, struct ip6_hdr *);
1882 th = (struct tcphdr *)(ip6 + 1);
1883 m->m_pkthdr.len = m->m_len =
1884 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1885 tcpip_fillheaders(inp, ip6, th);
1886 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1887 } else
1888 #endif /* INET6 */
1889 {
1890 ip = mtod(m, struct ip *);
1891 th = (struct tcphdr *)(ip + 1);
1892 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1893 tcpip_fillheaders(inp, ip, th);
1894 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1895 }
1896
1897 m_free(m);
1898 return (hdrsiz);
1899 }
1900 #endif /* IPSEC */
1901
1902 #ifdef TCP_SIGNATURE
1903 /*
1904 * Callback function invoked by m_apply() to digest TCP segment data
1905 * contained within an mbuf chain.
1906 */
1907 static int
1908 tcp_signature_apply(void *fstate, void *data, u_int len)
1909 {
1910
1911 MD5Update(fstate, (u_char *)data, len);
1912 return (0);
1913 }
1914
1915 /*
1916 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1917 *
1918 * Parameters:
1919 * m pointer to head of mbuf chain
1920 * _unused
1921 * len length of TCP segment data, excluding options
1922 * optlen length of TCP segment options
1923 * buf pointer to storage for computed MD5 digest
1924 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1925 *
1926 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1927 * When called from tcp_input(), we can be sure that th_sum has been
1928 * zeroed out and verified already.
1929 *
1930 * Return 0 if successful, otherwise return -1.
1931 *
1932 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1933 * search with the destination IP address, and a 'magic SPI' to be
1934 * determined by the application. This is hardcoded elsewhere to 1179
1935 * right now. Another branch of this code exists which uses the SPD to
1936 * specify per-application flows but it is unstable.
1937 */
1938 int
1939 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1940 u_char *buf, u_int direction)
1941 {
1942 union sockaddr_union dst;
1943 #ifdef INET
1944 struct ippseudo ippseudo;
1945 #endif
1946 MD5_CTX ctx;
1947 int doff;
1948 struct ip *ip;
1949 #ifdef INET
1950 struct ipovly *ipovly;
1951 #endif
1952 struct secasvar *sav;
1953 struct tcphdr *th;
1954 #ifdef INET6
1955 struct ip6_hdr *ip6;
1956 struct in6_addr in6;
1957 char ip6buf[INET6_ADDRSTRLEN];
1958 uint32_t plen;
1959 uint16_t nhdr;
1960 #endif
1961 u_short savecsum;
1962
1963 KASSERT(m != NULL, ("NULL mbuf chain"));
1964 KASSERT(buf != NULL, ("NULL signature pointer"));
1965
1966 /* Extract the destination from the IP header in the mbuf. */
1967 bzero(&dst, sizeof(union sockaddr_union));
1968 ip = mtod(m, struct ip *);
1969 #ifdef INET6
1970 ip6 = NULL; /* Make the compiler happy. */
1971 #endif
1972 switch (ip->ip_v) {
1973 #ifdef INET
1974 case IPVERSION:
1975 dst.sa.sa_len = sizeof(struct sockaddr_in);
1976 dst.sa.sa_family = AF_INET;
1977 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1978 ip->ip_src : ip->ip_dst;
1979 break;
1980 #endif
1981 #ifdef INET6
1982 case (IPV6_VERSION >> 4):
1983 ip6 = mtod(m, struct ip6_hdr *);
1984 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1985 dst.sa.sa_family = AF_INET6;
1986 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1987 ip6->ip6_src : ip6->ip6_dst;
1988 break;
1989 #endif
1990 default:
1991 return (EINVAL);
1992 /* NOTREACHED */
1993 break;
1994 }
1995
1996 /* Look up an SADB entry which matches the address of the peer. */
1997 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1998 if (sav == NULL) {
1999 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
2000 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
2001 #ifdef INET6
2002 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2003 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2004 #endif
2005 "(unsupported)"));
2006 return (EINVAL);
2007 }
2008
2009 MD5Init(&ctx);
2010 /*
2011 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2012 *
2013 * XXX The ippseudo header MUST be digested in network byte order,
2014 * or else we'll fail the regression test. Assume all fields we've
2015 * been doing arithmetic on have been in host byte order.
2016 * XXX One cannot depend on ipovly->ih_len here. When called from
2017 * tcp_output(), the underlying ip_len member has not yet been set.
2018 */
2019 switch (ip->ip_v) {
2020 #ifdef INET
2021 case IPVERSION:
2022 ipovly = (struct ipovly *)ip;
2023 ippseudo.ippseudo_src = ipovly->ih_src;
2024 ippseudo.ippseudo_dst = ipovly->ih_dst;
2025 ippseudo.ippseudo_pad = 0;
2026 ippseudo.ippseudo_p = IPPROTO_TCP;
2027 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2028 optlen);
2029 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2030
2031 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2032 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2033 break;
2034 #endif
2035 #ifdef INET6
2036 /*
2037 * RFC 2385, 2.0 Proposal
2038 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2039 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2040 * extended next header value (to form 32 bits), and 32-bit segment
2041 * length.
2042 * Note: Upper-Layer Packet Length comes before Next Header.
2043 */
2044 case (IPV6_VERSION >> 4):
2045 in6 = ip6->ip6_src;
2046 in6_clearscope(&in6);
2047 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2048 in6 = ip6->ip6_dst;
2049 in6_clearscope(&in6);
2050 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2051 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2052 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2053 nhdr = 0;
2054 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2055 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2056 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2057 nhdr = IPPROTO_TCP;
2058 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2059
2060 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2061 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2062 break;
2063 #endif
2064 default:
2065 return (EINVAL);
2066 /* NOTREACHED */
2067 break;
2068 }
2069
2070
2071 /*
2072 * Step 2: Update MD5 hash with TCP header, excluding options.
2073 * The TCP checksum must be set to zero.
2074 */
2075 savecsum = th->th_sum;
2076 th->th_sum = 0;
2077 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2078 th->th_sum = savecsum;
2079
2080 /*
2081 * Step 3: Update MD5 hash with TCP segment data.
2082 * Use m_apply() to avoid an early m_pullup().
2083 */
2084 if (len > 0)
2085 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2086
2087 /*
2088 * Step 4: Update MD5 hash with shared secret.
2089 */
2090 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2091 MD5Final(buf, &ctx);
2092
2093 key_sa_recordxfer(sav, m);
2094 KEY_FREESAV(&sav);
2095 return (0);
2096 }
2097
2098 /*
2099 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2100 *
2101 * Parameters:
2102 * m pointer to head of mbuf chain
2103 * len length of TCP segment data, excluding options
2104 * optlen length of TCP segment options
2105 * buf pointer to storage for computed MD5 digest
2106 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2107 *
2108 * Return 1 if successful, otherwise return 0.
2109 */
2110 int
2111 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2112 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2113 {
2114 char tmpdigest[TCP_SIGLEN];
2115
2116 if (tcp_sig_checksigs == 0)
2117 return (1);
2118 if ((tcpbflag & TF_SIGNATURE) == 0) {
2119 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2120
2121 /*
2122 * If this socket is not expecting signature but
2123 * the segment contains signature just fail.
2124 */
2125 TCPSTAT_INC(tcps_sig_err_sigopt);
2126 TCPSTAT_INC(tcps_sig_rcvbadsig);
2127 return (0);
2128 }
2129
2130 /* Signature is not expected, and not present in segment. */
2131 return (1);
2132 }
2133
2134 /*
2135 * If this socket is expecting signature but the segment does not
2136 * contain any just fail.
2137 */
2138 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2139 TCPSTAT_INC(tcps_sig_err_nosigopt);
2140 TCPSTAT_INC(tcps_sig_rcvbadsig);
2141 return (0);
2142 }
2143 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2144 IPSEC_DIR_INBOUND) == -1) {
2145 TCPSTAT_INC(tcps_sig_err_buildsig);
2146 TCPSTAT_INC(tcps_sig_rcvbadsig);
2147 return (0);
2148 }
2149
2150 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2151 TCPSTAT_INC(tcps_sig_rcvbadsig);
2152 return (0);
2153 }
2154 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2155 return (1);
2156 }
2157 #endif /* TCP_SIGNATURE */
2158
2159 static int
2160 sysctl_drop(SYSCTL_HANDLER_ARGS)
2161 {
2162 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2163 struct sockaddr_storage addrs[2];
2164 struct inpcb *inp;
2165 struct tcpcb *tp;
2166 struct tcptw *tw;
2167 struct sockaddr_in *fin, *lin;
2168 #ifdef INET6
2169 struct sockaddr_in6 *fin6, *lin6;
2170 #endif
2171 int error;
2172
2173 inp = NULL;
2174 fin = lin = NULL;
2175 #ifdef INET6
2176 fin6 = lin6 = NULL;
2177 #endif
2178 error = 0;
2179
2180 if (req->oldptr != NULL || req->oldlen != 0)
2181 return (EINVAL);
2182 if (req->newptr == NULL)
2183 return (EPERM);
2184 if (req->newlen < sizeof(addrs))
2185 return (ENOMEM);
2186 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2187 if (error)
2188 return (error);
2189
2190 switch (addrs[0].ss_family) {
2191 #ifdef INET6
2192 case AF_INET6:
2193 fin6 = (struct sockaddr_in6 *)&addrs[0];
2194 lin6 = (struct sockaddr_in6 *)&addrs[1];
2195 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2196 lin6->sin6_len != sizeof(struct sockaddr_in6))
2197 return (EINVAL);
2198 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2199 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2200 return (EINVAL);
2201 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2202 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2203 fin = (struct sockaddr_in *)&addrs[0];
2204 lin = (struct sockaddr_in *)&addrs[1];
2205 break;
2206 }
2207 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2208 if (error)
2209 return (error);
2210 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2211 if (error)
2212 return (error);
2213 break;
2214 #endif
2215 #ifdef INET
2216 case AF_INET:
2217 fin = (struct sockaddr_in *)&addrs[0];
2218 lin = (struct sockaddr_in *)&addrs[1];
2219 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2220 lin->sin_len != sizeof(struct sockaddr_in))
2221 return (EINVAL);
2222 break;
2223 #endif
2224 default:
2225 return (EINVAL);
2226 }
2227 INP_INFO_WLOCK(&V_tcbinfo);
2228 switch (addrs[0].ss_family) {
2229 #ifdef INET6
2230 case AF_INET6:
2231 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2232 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2233 INPLOOKUP_WLOCKPCB, NULL);
2234 break;
2235 #endif
2236 #ifdef INET
2237 case AF_INET:
2238 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2239 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2240 break;
2241 #endif
2242 }
2243 if (inp != NULL) {
2244 if (inp->inp_flags & INP_TIMEWAIT) {
2245 /*
2246 * XXXRW: There currently exists a state where an
2247 * inpcb is present, but its timewait state has been
2248 * discarded. For now, don't allow dropping of this
2249 * type of inpcb.
2250 */
2251 tw = intotw(inp);
2252 if (tw != NULL)
2253 tcp_twclose(tw, 0);
2254 else
2255 INP_WUNLOCK(inp);
2256 } else if (!(inp->inp_flags & INP_DROPPED) &&
2257 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2258 tp = intotcpcb(inp);
2259 tp = tcp_drop(tp, ECONNABORTED);
2260 if (tp != NULL)
2261 INP_WUNLOCK(inp);
2262 } else
2263 INP_WUNLOCK(inp);
2264 } else
2265 error = ESRCH;
2266 INP_INFO_WUNLOCK(&V_tcbinfo);
2267 return (error);
2268 }
2269
2270 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2271 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2272 0, sysctl_drop, "", "Drop TCP connection");
2273
2274 /*
2275 * Generate a standardized TCP log line for use throughout the
2276 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2277 * allow use in the interrupt context.
2278 *
2279 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2280 * NB: The function may return NULL if memory allocation failed.
2281 *
2282 * Due to header inclusion and ordering limitations the struct ip
2283 * and ip6_hdr pointers have to be passed as void pointers.
2284 */
2285 char *
2286 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2287 const void *ip6hdr)
2288 {
2289
2290 /* Is logging enabled? */
2291 if (tcp_log_in_vain == 0)
2292 return (NULL);
2293
2294 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2295 }
2296
2297 char *
2298 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2299 const void *ip6hdr)
2300 {
2301
2302 /* Is logging enabled? */
2303 if (tcp_log_debug == 0)
2304 return (NULL);
2305
2306 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2307 }
2308
2309 static char *
2310 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2311 const void *ip6hdr)
2312 {
2313 char *s, *sp;
2314 size_t size;
2315 struct ip *ip;
2316 #ifdef INET6
2317 const struct ip6_hdr *ip6;
2318
2319 ip6 = (const struct ip6_hdr *)ip6hdr;
2320 #endif /* INET6 */
2321 ip = (struct ip *)ip4hdr;
2322
2323 /*
2324 * The log line looks like this:
2325 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2326 */
2327 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2328 sizeof(PRINT_TH_FLAGS) + 1 +
2329 #ifdef INET6
2330 2 * INET6_ADDRSTRLEN;
2331 #else
2332 2 * INET_ADDRSTRLEN;
2333 #endif /* INET6 */
2334
2335 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2336 if (s == NULL)
2337 return (NULL);
2338
2339 strcat(s, "TCP: [");
2340 sp = s + strlen(s);
2341
2342 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2343 inet_ntoa_r(inc->inc_faddr, sp);
2344 sp = s + strlen(s);
2345 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2346 sp = s + strlen(s);
2347 inet_ntoa_r(inc->inc_laddr, sp);
2348 sp = s + strlen(s);
2349 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2350 #ifdef INET6
2351 } else if (inc) {
2352 ip6_sprintf(sp, &inc->inc6_faddr);
2353 sp = s + strlen(s);
2354 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2355 sp = s + strlen(s);
2356 ip6_sprintf(sp, &inc->inc6_laddr);
2357 sp = s + strlen(s);
2358 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2359 } else if (ip6 && th) {
2360 ip6_sprintf(sp, &ip6->ip6_src);
2361 sp = s + strlen(s);
2362 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2363 sp = s + strlen(s);
2364 ip6_sprintf(sp, &ip6->ip6_dst);
2365 sp = s + strlen(s);
2366 sprintf(sp, "]:%i", ntohs(th->th_dport));
2367 #endif /* INET6 */
2368 #ifdef INET
2369 } else if (ip && th) {
2370 inet_ntoa_r(ip->ip_src, sp);
2371 sp = s + strlen(s);
2372 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2373 sp = s + strlen(s);
2374 inet_ntoa_r(ip->ip_dst, sp);
2375 sp = s + strlen(s);
2376 sprintf(sp, "]:%i", ntohs(th->th_dport));
2377 #endif /* INET */
2378 } else {
2379 free(s, M_TCPLOG);
2380 return (NULL);
2381 }
2382 sp = s + strlen(s);
2383 if (th)
2384 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2385 if (*(s + size - 1) != '\0')
2386 panic("%s: string too long", __func__);
2387 return (s);
2388 }
2389
2390 /*
2391 * A subroutine which makes it easy to track TCP state changes with DTrace.
2392 * This function shouldn't be called for t_state initializations that don't
2393 * correspond to actual TCP state transitions.
2394 */
2395 void
2396 tcp_state_change(struct tcpcb *tp, int newstate)
2397 {
2398 #if defined(KDTRACE_HOOKS)
2399 int pstate = tp->t_state;
2400 #endif
2401
2402 tp->t_state = newstate;
2403 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);
2404 }
Cache object: 661f0175deb3cd30cb4b974f41470741
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