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/10.0/sys/netinet/tcp_subr.c 254889 2013-08-25 21:54:41Z markj $");
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 tcp_reass_init();
379
380 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
381 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
382 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
383
384 /* Skip initialization of globals for non-default instances. */
385 if (!IS_DEFAULT_VNET(curvnet))
386 return;
387
388 /* XXX virtualize those bellow? */
389 tcp_delacktime = TCPTV_DELACK;
390 tcp_keepinit = TCPTV_KEEP_INIT;
391 tcp_keepidle = TCPTV_KEEP_IDLE;
392 tcp_keepintvl = TCPTV_KEEPINTVL;
393 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
394 tcp_msl = TCPTV_MSL;
395 tcp_rexmit_min = TCPTV_MIN;
396 if (tcp_rexmit_min < 1)
397 tcp_rexmit_min = 1;
398 tcp_rexmit_slop = TCPTV_CPU_VAR;
399 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
400 tcp_tcbhashsize = hashsize;
401
402 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
403 if (tcp_soreceive_stream) {
404 #ifdef INET
405 tcp_usrreqs.pru_soreceive = soreceive_stream;
406 #endif
407 #ifdef INET6
408 tcp6_usrreqs.pru_soreceive = soreceive_stream;
409 #endif /* INET6 */
410 }
411
412 #ifdef INET6
413 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
414 #else /* INET6 */
415 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
416 #endif /* INET6 */
417 if (max_protohdr < TCP_MINPROTOHDR)
418 max_protohdr = TCP_MINPROTOHDR;
419 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
420 panic("tcp_init");
421 #undef TCP_MINPROTOHDR
422
423 ISN_LOCK_INIT();
424 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
425 SHUTDOWN_PRI_DEFAULT);
426 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
427 EVENTHANDLER_PRI_ANY);
428 }
429
430 #ifdef VIMAGE
431 void
432 tcp_destroy(void)
433 {
434
435 tcp_reass_destroy();
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, m->m_data, tp, nth);
710
711 TCP_PROBE5(send, NULL, tp, m->m_data, tp, nth);
712 #ifdef INET6
713 if (isipv6)
714 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
715 #endif /* INET6 */
716 #if defined(INET) && defined(INET6)
717 else
718 #endif
719 #ifdef INET
720 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
721 #endif
722 }
723
724 /*
725 * Create a new TCP control block, making an
726 * empty reassembly queue and hooking it to the argument
727 * protocol control block. The `inp' parameter must have
728 * come from the zone allocator set up in tcp_init().
729 */
730 struct tcpcb *
731 tcp_newtcpcb(struct inpcb *inp)
732 {
733 struct tcpcb_mem *tm;
734 struct tcpcb *tp;
735 #ifdef INET6
736 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
737 #endif /* INET6 */
738
739 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
740 if (tm == NULL)
741 return (NULL);
742 tp = &tm->tcb;
743
744 /* Initialise cc_var struct for this tcpcb. */
745 tp->ccv = &tm->ccv;
746 tp->ccv->type = IPPROTO_TCP;
747 tp->ccv->ccvc.tcp = tp;
748
749 /*
750 * Use the current system default CC algorithm.
751 */
752 CC_LIST_RLOCK();
753 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
754 CC_ALGO(tp) = CC_DEFAULT();
755 CC_LIST_RUNLOCK();
756
757 if (CC_ALGO(tp)->cb_init != NULL)
758 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
759 uma_zfree(V_tcpcb_zone, tm);
760 return (NULL);
761 }
762
763 tp->osd = &tm->osd;
764 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) {
765 uma_zfree(V_tcpcb_zone, tm);
766 return (NULL);
767 }
768
769 #ifdef VIMAGE
770 tp->t_vnet = inp->inp_vnet;
771 #endif
772 tp->t_timers = &tm->tt;
773 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
774 tp->t_maxseg = tp->t_maxopd =
775 #ifdef INET6
776 isipv6 ? V_tcp_v6mssdflt :
777 #endif /* INET6 */
778 V_tcp_mssdflt;
779
780 /* Set up our timeouts. */
781 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
782 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
783 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
784 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
785 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
786
787 if (V_tcp_do_rfc1323)
788 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
789 if (V_tcp_do_sack)
790 tp->t_flags |= TF_SACK_PERMIT;
791 TAILQ_INIT(&tp->snd_holes);
792 tp->t_inpcb = inp; /* XXX */
793 /*
794 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
795 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
796 * reasonable initial retransmit time.
797 */
798 tp->t_srtt = TCPTV_SRTTBASE;
799 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
800 tp->t_rttmin = tcp_rexmit_min;
801 tp->t_rxtcur = TCPTV_RTOBASE;
802 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
803 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
804 tp->t_rcvtime = ticks;
805 /*
806 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
807 * because the socket may be bound to an IPv6 wildcard address,
808 * which may match an IPv4-mapped IPv6 address.
809 */
810 inp->inp_ip_ttl = V_ip_defttl;
811 inp->inp_ppcb = tp;
812 return (tp); /* XXX */
813 }
814
815 /*
816 * Switch the congestion control algorithm back to NewReno for any active
817 * control blocks using an algorithm which is about to go away.
818 * This ensures the CC framework can allow the unload to proceed without leaving
819 * any dangling pointers which would trigger a panic.
820 * Returning non-zero would inform the CC framework that something went wrong
821 * and it would be unsafe to allow the unload to proceed. However, there is no
822 * way for this to occur with this implementation so we always return zero.
823 */
824 int
825 tcp_ccalgounload(struct cc_algo *unload_algo)
826 {
827 struct cc_algo *tmpalgo;
828 struct inpcb *inp;
829 struct tcpcb *tp;
830 VNET_ITERATOR_DECL(vnet_iter);
831
832 /*
833 * Check all active control blocks across all network stacks and change
834 * any that are using "unload_algo" back to NewReno. If "unload_algo"
835 * requires cleanup code to be run, call it.
836 */
837 VNET_LIST_RLOCK();
838 VNET_FOREACH(vnet_iter) {
839 CURVNET_SET(vnet_iter);
840 INP_INFO_RLOCK(&V_tcbinfo);
841 /*
842 * New connections already part way through being initialised
843 * with the CC algo we're removing will not race with this code
844 * because the INP_INFO_WLOCK is held during initialisation. We
845 * therefore don't enter the loop below until the connection
846 * list has stabilised.
847 */
848 LIST_FOREACH(inp, &V_tcb, inp_list) {
849 INP_WLOCK(inp);
850 /* Important to skip tcptw structs. */
851 if (!(inp->inp_flags & INP_TIMEWAIT) &&
852 (tp = intotcpcb(inp)) != NULL) {
853 /*
854 * By holding INP_WLOCK here, we are assured
855 * that the connection is not currently
856 * executing inside the CC module's functions
857 * i.e. it is safe to make the switch back to
858 * NewReno.
859 */
860 if (CC_ALGO(tp) == unload_algo) {
861 tmpalgo = CC_ALGO(tp);
862 /* NewReno does not require any init. */
863 CC_ALGO(tp) = &newreno_cc_algo;
864 if (tmpalgo->cb_destroy != NULL)
865 tmpalgo->cb_destroy(tp->ccv);
866 }
867 }
868 INP_WUNLOCK(inp);
869 }
870 INP_INFO_RUNLOCK(&V_tcbinfo);
871 CURVNET_RESTORE();
872 }
873 VNET_LIST_RUNLOCK();
874
875 return (0);
876 }
877
878 /*
879 * Drop a TCP connection, reporting
880 * the specified error. If connection is synchronized,
881 * then send a RST to peer.
882 */
883 struct tcpcb *
884 tcp_drop(struct tcpcb *tp, int errno)
885 {
886 struct socket *so = tp->t_inpcb->inp_socket;
887
888 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
889 INP_WLOCK_ASSERT(tp->t_inpcb);
890
891 if (TCPS_HAVERCVDSYN(tp->t_state)) {
892 tcp_state_change(tp, TCPS_CLOSED);
893 (void) tcp_output(tp);
894 TCPSTAT_INC(tcps_drops);
895 } else
896 TCPSTAT_INC(tcps_conndrops);
897 if (errno == ETIMEDOUT && tp->t_softerror)
898 errno = tp->t_softerror;
899 so->so_error = errno;
900 return (tcp_close(tp));
901 }
902
903 void
904 tcp_discardcb(struct tcpcb *tp)
905 {
906 struct inpcb *inp = tp->t_inpcb;
907 struct socket *so = inp->inp_socket;
908 #ifdef INET6
909 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
910 #endif /* INET6 */
911
912 INP_WLOCK_ASSERT(inp);
913
914 /*
915 * Make sure that all of our timers are stopped before we delete the
916 * PCB.
917 *
918 * XXXRW: Really, we would like to use callout_drain() here in order
919 * to avoid races experienced in tcp_timer.c where a timer is already
920 * executing at this point. However, we can't, both because we're
921 * running in a context where we can't sleep, and also because we
922 * hold locks required by the timers. What we instead need to do is
923 * test to see if callout_drain() is required, and if so, defer some
924 * portion of the remainder of tcp_discardcb() to an asynchronous
925 * context that can callout_drain() and then continue. Some care
926 * will be required to ensure that no further processing takes place
927 * on the tcpcb, even though it hasn't been freed (a flag?).
928 */
929 callout_stop(&tp->t_timers->tt_rexmt);
930 callout_stop(&tp->t_timers->tt_persist);
931 callout_stop(&tp->t_timers->tt_keep);
932 callout_stop(&tp->t_timers->tt_2msl);
933 callout_stop(&tp->t_timers->tt_delack);
934
935 /*
936 * If we got enough samples through the srtt filter,
937 * save the rtt and rttvar in the routing entry.
938 * 'Enough' is arbitrarily defined as 4 rtt samples.
939 * 4 samples is enough for the srtt filter to converge
940 * to within enough % of the correct value; fewer samples
941 * and we could save a bogus rtt. The danger is not high
942 * as tcp quickly recovers from everything.
943 * XXX: Works very well but needs some more statistics!
944 */
945 if (tp->t_rttupdated >= 4) {
946 struct hc_metrics_lite metrics;
947 u_long ssthresh;
948
949 bzero(&metrics, sizeof(metrics));
950 /*
951 * Update the ssthresh always when the conditions below
952 * are satisfied. This gives us better new start value
953 * for the congestion avoidance for new connections.
954 * ssthresh is only set if packet loss occured on a session.
955 *
956 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
957 * being torn down. Ideally this code would not use 'so'.
958 */
959 ssthresh = tp->snd_ssthresh;
960 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
961 /*
962 * convert the limit from user data bytes to
963 * packets then to packet data bytes.
964 */
965 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
966 if (ssthresh < 2)
967 ssthresh = 2;
968 ssthresh *= (u_long)(tp->t_maxseg +
969 #ifdef INET6
970 (isipv6 ? sizeof (struct ip6_hdr) +
971 sizeof (struct tcphdr) :
972 #endif
973 sizeof (struct tcpiphdr)
974 #ifdef INET6
975 )
976 #endif
977 );
978 } else
979 ssthresh = 0;
980 metrics.rmx_ssthresh = ssthresh;
981
982 metrics.rmx_rtt = tp->t_srtt;
983 metrics.rmx_rttvar = tp->t_rttvar;
984 metrics.rmx_cwnd = tp->snd_cwnd;
985 metrics.rmx_sendpipe = 0;
986 metrics.rmx_recvpipe = 0;
987
988 tcp_hc_update(&inp->inp_inc, &metrics);
989 }
990
991 /* free the reassembly queue, if any */
992 tcp_reass_flush(tp);
993
994 #ifdef TCP_OFFLOAD
995 /* Disconnect offload device, if any. */
996 if (tp->t_flags & TF_TOE)
997 tcp_offload_detach(tp);
998 #endif
999
1000 tcp_free_sackholes(tp);
1001
1002 /* Allow the CC algorithm to clean up after itself. */
1003 if (CC_ALGO(tp)->cb_destroy != NULL)
1004 CC_ALGO(tp)->cb_destroy(tp->ccv);
1005
1006 khelp_destroy_osd(tp->osd);
1007
1008 CC_ALGO(tp) = NULL;
1009 inp->inp_ppcb = NULL;
1010 tp->t_inpcb = NULL;
1011 uma_zfree(V_tcpcb_zone, tp);
1012 }
1013
1014 /*
1015 * Attempt to close a TCP control block, marking it as dropped, and freeing
1016 * the socket if we hold the only reference.
1017 */
1018 struct tcpcb *
1019 tcp_close(struct tcpcb *tp)
1020 {
1021 struct inpcb *inp = tp->t_inpcb;
1022 struct socket *so;
1023
1024 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1025 INP_WLOCK_ASSERT(inp);
1026
1027 #ifdef TCP_OFFLOAD
1028 if (tp->t_state == TCPS_LISTEN)
1029 tcp_offload_listen_stop(tp);
1030 #endif
1031 in_pcbdrop(inp);
1032 TCPSTAT_INC(tcps_closed);
1033 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
1034 so = inp->inp_socket;
1035 soisdisconnected(so);
1036 if (inp->inp_flags & INP_SOCKREF) {
1037 KASSERT(so->so_state & SS_PROTOREF,
1038 ("tcp_close: !SS_PROTOREF"));
1039 inp->inp_flags &= ~INP_SOCKREF;
1040 INP_WUNLOCK(inp);
1041 ACCEPT_LOCK();
1042 SOCK_LOCK(so);
1043 so->so_state &= ~SS_PROTOREF;
1044 sofree(so);
1045 return (NULL);
1046 }
1047 return (tp);
1048 }
1049
1050 void
1051 tcp_drain(void)
1052 {
1053 VNET_ITERATOR_DECL(vnet_iter);
1054
1055 if (!do_tcpdrain)
1056 return;
1057
1058 VNET_LIST_RLOCK_NOSLEEP();
1059 VNET_FOREACH(vnet_iter) {
1060 CURVNET_SET(vnet_iter);
1061 struct inpcb *inpb;
1062 struct tcpcb *tcpb;
1063
1064 /*
1065 * Walk the tcpbs, if existing, and flush the reassembly queue,
1066 * if there is one...
1067 * XXX: The "Net/3" implementation doesn't imply that the TCP
1068 * reassembly queue should be flushed, but in a situation
1069 * where we're really low on mbufs, this is potentially
1070 * useful.
1071 */
1072 INP_INFO_RLOCK(&V_tcbinfo);
1073 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
1074 if (inpb->inp_flags & INP_TIMEWAIT)
1075 continue;
1076 INP_WLOCK(inpb);
1077 if ((tcpb = intotcpcb(inpb)) != NULL) {
1078 tcp_reass_flush(tcpb);
1079 tcp_clean_sackreport(tcpb);
1080 }
1081 INP_WUNLOCK(inpb);
1082 }
1083 INP_INFO_RUNLOCK(&V_tcbinfo);
1084 CURVNET_RESTORE();
1085 }
1086 VNET_LIST_RUNLOCK_NOSLEEP();
1087 }
1088
1089 /*
1090 * Notify a tcp user of an asynchronous error;
1091 * store error as soft error, but wake up user
1092 * (for now, won't do anything until can select for soft error).
1093 *
1094 * Do not wake up user since there currently is no mechanism for
1095 * reporting soft errors (yet - a kqueue filter may be added).
1096 */
1097 static struct inpcb *
1098 tcp_notify(struct inpcb *inp, int error)
1099 {
1100 struct tcpcb *tp;
1101
1102 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1103 INP_WLOCK_ASSERT(inp);
1104
1105 if ((inp->inp_flags & INP_TIMEWAIT) ||
1106 (inp->inp_flags & INP_DROPPED))
1107 return (inp);
1108
1109 tp = intotcpcb(inp);
1110 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
1111
1112 /*
1113 * Ignore some errors if we are hooked up.
1114 * If connection hasn't completed, has retransmitted several times,
1115 * and receives a second error, give up now. This is better
1116 * than waiting a long time to establish a connection that
1117 * can never complete.
1118 */
1119 if (tp->t_state == TCPS_ESTABLISHED &&
1120 (error == EHOSTUNREACH || error == ENETUNREACH ||
1121 error == EHOSTDOWN)) {
1122 return (inp);
1123 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1124 tp->t_softerror) {
1125 tp = tcp_drop(tp, error);
1126 if (tp != NULL)
1127 return (inp);
1128 else
1129 return (NULL);
1130 } else {
1131 tp->t_softerror = error;
1132 return (inp);
1133 }
1134 #if 0
1135 wakeup( &so->so_timeo);
1136 sorwakeup(so);
1137 sowwakeup(so);
1138 #endif
1139 }
1140
1141 static int
1142 tcp_pcblist(SYSCTL_HANDLER_ARGS)
1143 {
1144 int error, i, m, n, pcb_count;
1145 struct inpcb *inp, **inp_list;
1146 inp_gen_t gencnt;
1147 struct xinpgen xig;
1148
1149 /*
1150 * The process of preparing the TCB list is too time-consuming and
1151 * resource-intensive to repeat twice on every request.
1152 */
1153 if (req->oldptr == NULL) {
1154 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1155 n += imax(n / 8, 10);
1156 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1157 return (0);
1158 }
1159
1160 if (req->newptr != NULL)
1161 return (EPERM);
1162
1163 /*
1164 * OK, now we're committed to doing something.
1165 */
1166 INP_INFO_RLOCK(&V_tcbinfo);
1167 gencnt = V_tcbinfo.ipi_gencnt;
1168 n = V_tcbinfo.ipi_count;
1169 INP_INFO_RUNLOCK(&V_tcbinfo);
1170
1171 m = syncache_pcbcount();
1172
1173 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1174 + (n + m) * sizeof(struct xtcpcb));
1175 if (error != 0)
1176 return (error);
1177
1178 xig.xig_len = sizeof xig;
1179 xig.xig_count = n + m;
1180 xig.xig_gen = gencnt;
1181 xig.xig_sogen = so_gencnt;
1182 error = SYSCTL_OUT(req, &xig, sizeof xig);
1183 if (error)
1184 return (error);
1185
1186 error = syncache_pcblist(req, m, &pcb_count);
1187 if (error)
1188 return (error);
1189
1190 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1191 if (inp_list == NULL)
1192 return (ENOMEM);
1193
1194 INP_INFO_RLOCK(&V_tcbinfo);
1195 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1196 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1197 INP_WLOCK(inp);
1198 if (inp->inp_gencnt <= gencnt) {
1199 /*
1200 * XXX: This use of cr_cansee(), introduced with
1201 * TCP state changes, is not quite right, but for
1202 * now, better than nothing.
1203 */
1204 if (inp->inp_flags & INP_TIMEWAIT) {
1205 if (intotw(inp) != NULL)
1206 error = cr_cansee(req->td->td_ucred,
1207 intotw(inp)->tw_cred);
1208 else
1209 error = EINVAL; /* Skip this inp. */
1210 } else
1211 error = cr_canseeinpcb(req->td->td_ucred, inp);
1212 if (error == 0) {
1213 in_pcbref(inp);
1214 inp_list[i++] = inp;
1215 }
1216 }
1217 INP_WUNLOCK(inp);
1218 }
1219 INP_INFO_RUNLOCK(&V_tcbinfo);
1220 n = i;
1221
1222 error = 0;
1223 for (i = 0; i < n; i++) {
1224 inp = inp_list[i];
1225 INP_RLOCK(inp);
1226 if (inp->inp_gencnt <= gencnt) {
1227 struct xtcpcb xt;
1228 void *inp_ppcb;
1229
1230 bzero(&xt, sizeof(xt));
1231 xt.xt_len = sizeof xt;
1232 /* XXX should avoid extra copy */
1233 bcopy(inp, &xt.xt_inp, sizeof *inp);
1234 inp_ppcb = inp->inp_ppcb;
1235 if (inp_ppcb == NULL)
1236 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1237 else if (inp->inp_flags & INP_TIMEWAIT) {
1238 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1239 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1240 } else {
1241 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1242 if (xt.xt_tp.t_timers)
1243 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1244 }
1245 if (inp->inp_socket != NULL)
1246 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1247 else {
1248 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1249 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1250 }
1251 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1252 INP_RUNLOCK(inp);
1253 error = SYSCTL_OUT(req, &xt, sizeof xt);
1254 } else
1255 INP_RUNLOCK(inp);
1256 }
1257 INP_INFO_WLOCK(&V_tcbinfo);
1258 for (i = 0; i < n; i++) {
1259 inp = inp_list[i];
1260 INP_RLOCK(inp);
1261 if (!in_pcbrele_rlocked(inp))
1262 INP_RUNLOCK(inp);
1263 }
1264 INP_INFO_WUNLOCK(&V_tcbinfo);
1265
1266 if (!error) {
1267 /*
1268 * Give the user an updated idea of our state.
1269 * If the generation differs from what we told
1270 * her before, she knows that something happened
1271 * while we were processing this request, and it
1272 * might be necessary to retry.
1273 */
1274 INP_INFO_RLOCK(&V_tcbinfo);
1275 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1276 xig.xig_sogen = so_gencnt;
1277 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1278 INP_INFO_RUNLOCK(&V_tcbinfo);
1279 error = SYSCTL_OUT(req, &xig, sizeof xig);
1280 }
1281 free(inp_list, M_TEMP);
1282 return (error);
1283 }
1284
1285 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
1286 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
1287 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1288
1289 #ifdef INET
1290 static int
1291 tcp_getcred(SYSCTL_HANDLER_ARGS)
1292 {
1293 struct xucred xuc;
1294 struct sockaddr_in addrs[2];
1295 struct inpcb *inp;
1296 int error;
1297
1298 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1299 if (error)
1300 return (error);
1301 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1302 if (error)
1303 return (error);
1304 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
1305 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
1306 if (inp != NULL) {
1307 if (inp->inp_socket == NULL)
1308 error = ENOENT;
1309 if (error == 0)
1310 error = cr_canseeinpcb(req->td->td_ucred, inp);
1311 if (error == 0)
1312 cru2x(inp->inp_cred, &xuc);
1313 INP_RUNLOCK(inp);
1314 } else
1315 error = ENOENT;
1316 if (error == 0)
1317 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1318 return (error);
1319 }
1320
1321 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1322 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1323 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1324 #endif /* INET */
1325
1326 #ifdef INET6
1327 static int
1328 tcp6_getcred(SYSCTL_HANDLER_ARGS)
1329 {
1330 struct xucred xuc;
1331 struct sockaddr_in6 addrs[2];
1332 struct inpcb *inp;
1333 int error;
1334 #ifdef INET
1335 int mapped = 0;
1336 #endif
1337
1338 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1339 if (error)
1340 return (error);
1341 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1342 if (error)
1343 return (error);
1344 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1345 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1346 return (error);
1347 }
1348 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1349 #ifdef INET
1350 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1351 mapped = 1;
1352 else
1353 #endif
1354 return (EINVAL);
1355 }
1356
1357 #ifdef INET
1358 if (mapped == 1)
1359 inp = in_pcblookup(&V_tcbinfo,
1360 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1361 addrs[1].sin6_port,
1362 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1363 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
1364 else
1365 #endif
1366 inp = in6_pcblookup(&V_tcbinfo,
1367 &addrs[1].sin6_addr, addrs[1].sin6_port,
1368 &addrs[0].sin6_addr, addrs[0].sin6_port,
1369 INPLOOKUP_RLOCKPCB, NULL);
1370 if (inp != NULL) {
1371 if (inp->inp_socket == NULL)
1372 error = ENOENT;
1373 if (error == 0)
1374 error = cr_canseeinpcb(req->td->td_ucred, inp);
1375 if (error == 0)
1376 cru2x(inp->inp_cred, &xuc);
1377 INP_RUNLOCK(inp);
1378 } else
1379 error = ENOENT;
1380 if (error == 0)
1381 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1382 return (error);
1383 }
1384
1385 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1386 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1387 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1388 #endif /* INET6 */
1389
1390
1391 #ifdef INET
1392 void
1393 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1394 {
1395 struct ip *ip = vip;
1396 struct tcphdr *th;
1397 struct in_addr faddr;
1398 struct inpcb *inp;
1399 struct tcpcb *tp;
1400 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1401 struct icmp *icp;
1402 struct in_conninfo inc;
1403 tcp_seq icmp_tcp_seq;
1404 int mtu;
1405
1406 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1407 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1408 return;
1409
1410 if (cmd == PRC_MSGSIZE)
1411 notify = tcp_mtudisc_notify;
1412 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1413 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1414 notify = tcp_drop_syn_sent;
1415 /*
1416 * Redirects don't need to be handled up here.
1417 */
1418 else if (PRC_IS_REDIRECT(cmd))
1419 return;
1420 /*
1421 * Source quench is depreciated.
1422 */
1423 else if (cmd == PRC_QUENCH)
1424 return;
1425 /*
1426 * Hostdead is ugly because it goes linearly through all PCBs.
1427 * XXX: We never get this from ICMP, otherwise it makes an
1428 * excellent DoS attack on machines with many connections.
1429 */
1430 else if (cmd == PRC_HOSTDEAD)
1431 ip = NULL;
1432 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1433 return;
1434 if (ip != NULL) {
1435 icp = (struct icmp *)((caddr_t)ip
1436 - offsetof(struct icmp, icmp_ip));
1437 th = (struct tcphdr *)((caddr_t)ip
1438 + (ip->ip_hl << 2));
1439 INP_INFO_WLOCK(&V_tcbinfo);
1440 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
1441 ip->ip_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
1442 if (inp != NULL) {
1443 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1444 !(inp->inp_flags & INP_DROPPED) &&
1445 !(inp->inp_socket == NULL)) {
1446 icmp_tcp_seq = htonl(th->th_seq);
1447 tp = intotcpcb(inp);
1448 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1449 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1450 if (cmd == PRC_MSGSIZE) {
1451 /*
1452 * MTU discovery:
1453 * If we got a needfrag set the MTU
1454 * in the route to the suggested new
1455 * value (if given) and then notify.
1456 */
1457 bzero(&inc, sizeof(inc));
1458 inc.inc_faddr = faddr;
1459 inc.inc_fibnum =
1460 inp->inp_inc.inc_fibnum;
1461
1462 mtu = ntohs(icp->icmp_nextmtu);
1463 /*
1464 * If no alternative MTU was
1465 * proposed, try the next smaller
1466 * one.
1467 */
1468 if (!mtu)
1469 mtu = ip_next_mtu(
1470 ntohs(ip->ip_len), 1);
1471 if (mtu < V_tcp_minmss
1472 + sizeof(struct tcpiphdr))
1473 mtu = V_tcp_minmss
1474 + sizeof(struct tcpiphdr);
1475 /*
1476 * Only cache the MTU if it
1477 * is smaller than the interface
1478 * or route MTU. tcp_mtudisc()
1479 * will do right thing by itself.
1480 */
1481 if (mtu <= tcp_maxmtu(&inc, NULL))
1482 tcp_hc_updatemtu(&inc, mtu);
1483 tcp_mtudisc(inp, mtu);
1484 } else
1485 inp = (*notify)(inp,
1486 inetctlerrmap[cmd]);
1487 }
1488 }
1489 if (inp != NULL)
1490 INP_WUNLOCK(inp);
1491 } else {
1492 bzero(&inc, sizeof(inc));
1493 inc.inc_fport = th->th_dport;
1494 inc.inc_lport = th->th_sport;
1495 inc.inc_faddr = faddr;
1496 inc.inc_laddr = ip->ip_src;
1497 syncache_unreach(&inc, th);
1498 }
1499 INP_INFO_WUNLOCK(&V_tcbinfo);
1500 } else
1501 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1502 }
1503 #endif /* INET */
1504
1505 #ifdef INET6
1506 void
1507 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1508 {
1509 struct tcphdr th;
1510 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1511 struct ip6_hdr *ip6;
1512 struct mbuf *m;
1513 struct ip6ctlparam *ip6cp = NULL;
1514 const struct sockaddr_in6 *sa6_src = NULL;
1515 int off;
1516 struct tcp_portonly {
1517 u_int16_t th_sport;
1518 u_int16_t th_dport;
1519 } *thp;
1520
1521 if (sa->sa_family != AF_INET6 ||
1522 sa->sa_len != sizeof(struct sockaddr_in6))
1523 return;
1524
1525 if (cmd == PRC_MSGSIZE)
1526 notify = tcp_mtudisc_notify;
1527 else if (!PRC_IS_REDIRECT(cmd) &&
1528 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1529 return;
1530 /* Source quench is depreciated. */
1531 else if (cmd == PRC_QUENCH)
1532 return;
1533
1534 /* if the parameter is from icmp6, decode it. */
1535 if (d != NULL) {
1536 ip6cp = (struct ip6ctlparam *)d;
1537 m = ip6cp->ip6c_m;
1538 ip6 = ip6cp->ip6c_ip6;
1539 off = ip6cp->ip6c_off;
1540 sa6_src = ip6cp->ip6c_src;
1541 } else {
1542 m = NULL;
1543 ip6 = NULL;
1544 off = 0; /* fool gcc */
1545 sa6_src = &sa6_any;
1546 }
1547
1548 if (ip6 != NULL) {
1549 struct in_conninfo inc;
1550 /*
1551 * XXX: We assume that when IPV6 is non NULL,
1552 * M and OFF are valid.
1553 */
1554
1555 /* check if we can safely examine src and dst ports */
1556 if (m->m_pkthdr.len < off + sizeof(*thp))
1557 return;
1558
1559 bzero(&th, sizeof(th));
1560 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1561
1562 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1563 (struct sockaddr *)ip6cp->ip6c_src,
1564 th.th_sport, cmd, NULL, notify);
1565
1566 bzero(&inc, sizeof(inc));
1567 inc.inc_fport = th.th_dport;
1568 inc.inc_lport = th.th_sport;
1569 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1570 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1571 inc.inc_flags |= INC_ISIPV6;
1572 INP_INFO_WLOCK(&V_tcbinfo);
1573 syncache_unreach(&inc, &th);
1574 INP_INFO_WUNLOCK(&V_tcbinfo);
1575 } else
1576 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1577 0, cmd, NULL, notify);
1578 }
1579 #endif /* INET6 */
1580
1581
1582 /*
1583 * Following is where TCP initial sequence number generation occurs.
1584 *
1585 * There are two places where we must use initial sequence numbers:
1586 * 1. In SYN-ACK packets.
1587 * 2. In SYN packets.
1588 *
1589 * All ISNs for SYN-ACK packets are generated by the syncache. See
1590 * tcp_syncache.c for details.
1591 *
1592 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1593 * depends on this property. In addition, these ISNs should be
1594 * unguessable so as to prevent connection hijacking. To satisfy
1595 * the requirements of this situation, the algorithm outlined in
1596 * RFC 1948 is used, with only small modifications.
1597 *
1598 * Implementation details:
1599 *
1600 * Time is based off the system timer, and is corrected so that it
1601 * increases by one megabyte per second. This allows for proper
1602 * recycling on high speed LANs while still leaving over an hour
1603 * before rollover.
1604 *
1605 * As reading the *exact* system time is too expensive to be done
1606 * whenever setting up a TCP connection, we increment the time
1607 * offset in two ways. First, a small random positive increment
1608 * is added to isn_offset for each connection that is set up.
1609 * Second, the function tcp_isn_tick fires once per clock tick
1610 * and increments isn_offset as necessary so that sequence numbers
1611 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1612 * random positive increments serve only to ensure that the same
1613 * exact sequence number is never sent out twice (as could otherwise
1614 * happen when a port is recycled in less than the system tick
1615 * interval.)
1616 *
1617 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1618 * between seeding of isn_secret. This is normally set to zero,
1619 * as reseeding should not be necessary.
1620 *
1621 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1622 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1623 * general, this means holding an exclusive (write) lock.
1624 */
1625
1626 #define ISN_BYTES_PER_SECOND 1048576
1627 #define ISN_STATIC_INCREMENT 4096
1628 #define ISN_RANDOM_INCREMENT (4096 - 1)
1629
1630 static VNET_DEFINE(u_char, isn_secret[32]);
1631 static VNET_DEFINE(int, isn_last);
1632 static VNET_DEFINE(int, isn_last_reseed);
1633 static VNET_DEFINE(u_int32_t, isn_offset);
1634 static VNET_DEFINE(u_int32_t, isn_offset_old);
1635
1636 #define V_isn_secret VNET(isn_secret)
1637 #define V_isn_last VNET(isn_last)
1638 #define V_isn_last_reseed VNET(isn_last_reseed)
1639 #define V_isn_offset VNET(isn_offset)
1640 #define V_isn_offset_old VNET(isn_offset_old)
1641
1642 tcp_seq
1643 tcp_new_isn(struct tcpcb *tp)
1644 {
1645 MD5_CTX isn_ctx;
1646 u_int32_t md5_buffer[4];
1647 tcp_seq new_isn;
1648 u_int32_t projected_offset;
1649
1650 INP_WLOCK_ASSERT(tp->t_inpcb);
1651
1652 ISN_LOCK();
1653 /* Seed if this is the first use, reseed if requested. */
1654 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1655 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1656 < (u_int)ticks))) {
1657 read_random(&V_isn_secret, sizeof(V_isn_secret));
1658 V_isn_last_reseed = ticks;
1659 }
1660
1661 /* Compute the md5 hash and return the ISN. */
1662 MD5Init(&isn_ctx);
1663 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1664 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1665 #ifdef INET6
1666 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1667 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1668 sizeof(struct in6_addr));
1669 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1670 sizeof(struct in6_addr));
1671 } else
1672 #endif
1673 {
1674 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1675 sizeof(struct in_addr));
1676 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1677 sizeof(struct in_addr));
1678 }
1679 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1680 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1681 new_isn = (tcp_seq) md5_buffer[0];
1682 V_isn_offset += ISN_STATIC_INCREMENT +
1683 (arc4random() & ISN_RANDOM_INCREMENT);
1684 if (ticks != V_isn_last) {
1685 projected_offset = V_isn_offset_old +
1686 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
1687 if (SEQ_GT(projected_offset, V_isn_offset))
1688 V_isn_offset = projected_offset;
1689 V_isn_offset_old = V_isn_offset;
1690 V_isn_last = ticks;
1691 }
1692 new_isn += V_isn_offset;
1693 ISN_UNLOCK();
1694 return (new_isn);
1695 }
1696
1697 /*
1698 * When a specific ICMP unreachable message is received and the
1699 * connection state is SYN-SENT, drop the connection. This behavior
1700 * is controlled by the icmp_may_rst sysctl.
1701 */
1702 struct inpcb *
1703 tcp_drop_syn_sent(struct inpcb *inp, int errno)
1704 {
1705 struct tcpcb *tp;
1706
1707 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1708 INP_WLOCK_ASSERT(inp);
1709
1710 if ((inp->inp_flags & INP_TIMEWAIT) ||
1711 (inp->inp_flags & INP_DROPPED))
1712 return (inp);
1713
1714 tp = intotcpcb(inp);
1715 if (tp->t_state != TCPS_SYN_SENT)
1716 return (inp);
1717
1718 tp = tcp_drop(tp, errno);
1719 if (tp != NULL)
1720 return (inp);
1721 else
1722 return (NULL);
1723 }
1724
1725 /*
1726 * When `need fragmentation' ICMP is received, update our idea of the MSS
1727 * based on the new value. Also nudge TCP to send something, since we
1728 * know the packet we just sent was dropped.
1729 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1730 */
1731 static struct inpcb *
1732 tcp_mtudisc_notify(struct inpcb *inp, int error)
1733 {
1734
1735 return (tcp_mtudisc(inp, -1));
1736 }
1737
1738 struct inpcb *
1739 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
1740 {
1741 struct tcpcb *tp;
1742 struct socket *so;
1743
1744 INP_WLOCK_ASSERT(inp);
1745 if ((inp->inp_flags & INP_TIMEWAIT) ||
1746 (inp->inp_flags & INP_DROPPED))
1747 return (inp);
1748
1749 tp = intotcpcb(inp);
1750 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1751
1752 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
1753
1754 so = inp->inp_socket;
1755 SOCKBUF_LOCK(&so->so_snd);
1756 /* If the mss is larger than the socket buffer, decrease the mss. */
1757 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1758 tp->t_maxseg = so->so_snd.sb_hiwat;
1759 SOCKBUF_UNLOCK(&so->so_snd);
1760
1761 TCPSTAT_INC(tcps_mturesent);
1762 tp->t_rtttime = 0;
1763 tp->snd_nxt = tp->snd_una;
1764 tcp_free_sackholes(tp);
1765 tp->snd_recover = tp->snd_max;
1766 if (tp->t_flags & TF_SACK_PERMIT)
1767 EXIT_FASTRECOVERY(tp->t_flags);
1768 tcp_output(tp);
1769 return (inp);
1770 }
1771
1772 #ifdef INET
1773 /*
1774 * Look-up the routing entry to the peer of this inpcb. If no route
1775 * is found and it cannot be allocated, then return 0. This routine
1776 * is called by TCP routines that access the rmx structure and by
1777 * tcp_mss_update to get the peer/interface MTU.
1778 */
1779 u_long
1780 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
1781 {
1782 struct route sro;
1783 struct sockaddr_in *dst;
1784 struct ifnet *ifp;
1785 u_long maxmtu = 0;
1786
1787 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1788
1789 bzero(&sro, sizeof(sro));
1790 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1791 dst = (struct sockaddr_in *)&sro.ro_dst;
1792 dst->sin_family = AF_INET;
1793 dst->sin_len = sizeof(*dst);
1794 dst->sin_addr = inc->inc_faddr;
1795 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1796 }
1797 if (sro.ro_rt != NULL) {
1798 ifp = sro.ro_rt->rt_ifp;
1799 if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
1800 maxmtu = ifp->if_mtu;
1801 else
1802 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
1803
1804 /* Report additional interface capabilities. */
1805 if (cap != NULL) {
1806 if (ifp->if_capenable & IFCAP_TSO4 &&
1807 ifp->if_hwassist & CSUM_TSO)
1808 cap->ifcap |= CSUM_TSO;
1809 cap->tsomax = ifp->if_hw_tsomax;
1810 }
1811 RTFREE(sro.ro_rt);
1812 }
1813 return (maxmtu);
1814 }
1815 #endif /* INET */
1816
1817 #ifdef INET6
1818 u_long
1819 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
1820 {
1821 struct route_in6 sro6;
1822 struct ifnet *ifp;
1823 u_long maxmtu = 0;
1824
1825 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1826
1827 bzero(&sro6, sizeof(sro6));
1828 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1829 sro6.ro_dst.sin6_family = AF_INET6;
1830 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1831 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1832 in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
1833 }
1834 if (sro6.ro_rt != NULL) {
1835 ifp = sro6.ro_rt->rt_ifp;
1836 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
1837 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1838 else
1839 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
1840 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1841
1842 /* Report additional interface capabilities. */
1843 if (cap != NULL) {
1844 if (ifp->if_capenable & IFCAP_TSO6 &&
1845 ifp->if_hwassist & CSUM_TSO)
1846 cap->ifcap |= CSUM_TSO;
1847 cap->tsomax = ifp->if_hw_tsomax;
1848 }
1849 RTFREE(sro6.ro_rt);
1850 }
1851
1852 return (maxmtu);
1853 }
1854 #endif /* INET6 */
1855
1856 #ifdef IPSEC
1857 /* compute ESP/AH header size for TCP, including outer IP header. */
1858 size_t
1859 ipsec_hdrsiz_tcp(struct tcpcb *tp)
1860 {
1861 struct inpcb *inp;
1862 struct mbuf *m;
1863 size_t hdrsiz;
1864 struct ip *ip;
1865 #ifdef INET6
1866 struct ip6_hdr *ip6;
1867 #endif
1868 struct tcphdr *th;
1869
1870 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1871 return (0);
1872 m = m_gethdr(M_NOWAIT, MT_DATA);
1873 if (!m)
1874 return (0);
1875
1876 #ifdef INET6
1877 if ((inp->inp_vflag & INP_IPV6) != 0) {
1878 ip6 = mtod(m, struct ip6_hdr *);
1879 th = (struct tcphdr *)(ip6 + 1);
1880 m->m_pkthdr.len = m->m_len =
1881 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1882 tcpip_fillheaders(inp, ip6, th);
1883 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1884 } else
1885 #endif /* INET6 */
1886 {
1887 ip = mtod(m, struct ip *);
1888 th = (struct tcphdr *)(ip + 1);
1889 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1890 tcpip_fillheaders(inp, ip, th);
1891 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1892 }
1893
1894 m_free(m);
1895 return (hdrsiz);
1896 }
1897 #endif /* IPSEC */
1898
1899 #ifdef TCP_SIGNATURE
1900 /*
1901 * Callback function invoked by m_apply() to digest TCP segment data
1902 * contained within an mbuf chain.
1903 */
1904 static int
1905 tcp_signature_apply(void *fstate, void *data, u_int len)
1906 {
1907
1908 MD5Update(fstate, (u_char *)data, len);
1909 return (0);
1910 }
1911
1912 /*
1913 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1914 *
1915 * Parameters:
1916 * m pointer to head of mbuf chain
1917 * _unused
1918 * len length of TCP segment data, excluding options
1919 * optlen length of TCP segment options
1920 * buf pointer to storage for computed MD5 digest
1921 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1922 *
1923 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1924 * When called from tcp_input(), we can be sure that th_sum has been
1925 * zeroed out and verified already.
1926 *
1927 * Return 0 if successful, otherwise return -1.
1928 *
1929 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1930 * search with the destination IP address, and a 'magic SPI' to be
1931 * determined by the application. This is hardcoded elsewhere to 1179
1932 * right now. Another branch of this code exists which uses the SPD to
1933 * specify per-application flows but it is unstable.
1934 */
1935 int
1936 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1937 u_char *buf, u_int direction)
1938 {
1939 union sockaddr_union dst;
1940 #ifdef INET
1941 struct ippseudo ippseudo;
1942 #endif
1943 MD5_CTX ctx;
1944 int doff;
1945 struct ip *ip;
1946 #ifdef INET
1947 struct ipovly *ipovly;
1948 #endif
1949 struct secasvar *sav;
1950 struct tcphdr *th;
1951 #ifdef INET6
1952 struct ip6_hdr *ip6;
1953 struct in6_addr in6;
1954 char ip6buf[INET6_ADDRSTRLEN];
1955 uint32_t plen;
1956 uint16_t nhdr;
1957 #endif
1958 u_short savecsum;
1959
1960 KASSERT(m != NULL, ("NULL mbuf chain"));
1961 KASSERT(buf != NULL, ("NULL signature pointer"));
1962
1963 /* Extract the destination from the IP header in the mbuf. */
1964 bzero(&dst, sizeof(union sockaddr_union));
1965 ip = mtod(m, struct ip *);
1966 #ifdef INET6
1967 ip6 = NULL; /* Make the compiler happy. */
1968 #endif
1969 switch (ip->ip_v) {
1970 #ifdef INET
1971 case IPVERSION:
1972 dst.sa.sa_len = sizeof(struct sockaddr_in);
1973 dst.sa.sa_family = AF_INET;
1974 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1975 ip->ip_src : ip->ip_dst;
1976 break;
1977 #endif
1978 #ifdef INET6
1979 case (IPV6_VERSION >> 4):
1980 ip6 = mtod(m, struct ip6_hdr *);
1981 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1982 dst.sa.sa_family = AF_INET6;
1983 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1984 ip6->ip6_src : ip6->ip6_dst;
1985 break;
1986 #endif
1987 default:
1988 return (EINVAL);
1989 /* NOTREACHED */
1990 break;
1991 }
1992
1993 /* Look up an SADB entry which matches the address of the peer. */
1994 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1995 if (sav == NULL) {
1996 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
1997 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
1998 #ifdef INET6
1999 (ip->ip_v == (IPV6_VERSION >> 4)) ?
2000 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
2001 #endif
2002 "(unsupported)"));
2003 return (EINVAL);
2004 }
2005
2006 MD5Init(&ctx);
2007 /*
2008 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
2009 *
2010 * XXX The ippseudo header MUST be digested in network byte order,
2011 * or else we'll fail the regression test. Assume all fields we've
2012 * been doing arithmetic on have been in host byte order.
2013 * XXX One cannot depend on ipovly->ih_len here. When called from
2014 * tcp_output(), the underlying ip_len member has not yet been set.
2015 */
2016 switch (ip->ip_v) {
2017 #ifdef INET
2018 case IPVERSION:
2019 ipovly = (struct ipovly *)ip;
2020 ippseudo.ippseudo_src = ipovly->ih_src;
2021 ippseudo.ippseudo_dst = ipovly->ih_dst;
2022 ippseudo.ippseudo_pad = 0;
2023 ippseudo.ippseudo_p = IPPROTO_TCP;
2024 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
2025 optlen);
2026 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
2027
2028 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
2029 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
2030 break;
2031 #endif
2032 #ifdef INET6
2033 /*
2034 * RFC 2385, 2.0 Proposal
2035 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
2036 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
2037 * extended next header value (to form 32 bits), and 32-bit segment
2038 * length.
2039 * Note: Upper-Layer Packet Length comes before Next Header.
2040 */
2041 case (IPV6_VERSION >> 4):
2042 in6 = ip6->ip6_src;
2043 in6_clearscope(&in6);
2044 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2045 in6 = ip6->ip6_dst;
2046 in6_clearscope(&in6);
2047 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
2048 plen = htonl(len + sizeof(struct tcphdr) + optlen);
2049 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
2050 nhdr = 0;
2051 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2052 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2053 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2054 nhdr = IPPROTO_TCP;
2055 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
2056
2057 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
2058 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
2059 break;
2060 #endif
2061 default:
2062 return (EINVAL);
2063 /* NOTREACHED */
2064 break;
2065 }
2066
2067
2068 /*
2069 * Step 2: Update MD5 hash with TCP header, excluding options.
2070 * The TCP checksum must be set to zero.
2071 */
2072 savecsum = th->th_sum;
2073 th->th_sum = 0;
2074 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
2075 th->th_sum = savecsum;
2076
2077 /*
2078 * Step 3: Update MD5 hash with TCP segment data.
2079 * Use m_apply() to avoid an early m_pullup().
2080 */
2081 if (len > 0)
2082 m_apply(m, doff, len, tcp_signature_apply, &ctx);
2083
2084 /*
2085 * Step 4: Update MD5 hash with shared secret.
2086 */
2087 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
2088 MD5Final(buf, &ctx);
2089
2090 key_sa_recordxfer(sav, m);
2091 KEY_FREESAV(&sav);
2092 return (0);
2093 }
2094
2095 /*
2096 * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
2097 *
2098 * Parameters:
2099 * m pointer to head of mbuf chain
2100 * len length of TCP segment data, excluding options
2101 * optlen length of TCP segment options
2102 * buf pointer to storage for computed MD5 digest
2103 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
2104 *
2105 * Return 1 if successful, otherwise return 0.
2106 */
2107 int
2108 tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
2109 struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
2110 {
2111 char tmpdigest[TCP_SIGLEN];
2112
2113 if (tcp_sig_checksigs == 0)
2114 return (1);
2115 if ((tcpbflag & TF_SIGNATURE) == 0) {
2116 if ((to->to_flags & TOF_SIGNATURE) != 0) {
2117
2118 /*
2119 * If this socket is not expecting signature but
2120 * the segment contains signature just fail.
2121 */
2122 TCPSTAT_INC(tcps_sig_err_sigopt);
2123 TCPSTAT_INC(tcps_sig_rcvbadsig);
2124 return (0);
2125 }
2126
2127 /* Signature is not expected, and not present in segment. */
2128 return (1);
2129 }
2130
2131 /*
2132 * If this socket is expecting signature but the segment does not
2133 * contain any just fail.
2134 */
2135 if ((to->to_flags & TOF_SIGNATURE) == 0) {
2136 TCPSTAT_INC(tcps_sig_err_nosigopt);
2137 TCPSTAT_INC(tcps_sig_rcvbadsig);
2138 return (0);
2139 }
2140 if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
2141 IPSEC_DIR_INBOUND) == -1) {
2142 TCPSTAT_INC(tcps_sig_err_buildsig);
2143 TCPSTAT_INC(tcps_sig_rcvbadsig);
2144 return (0);
2145 }
2146
2147 if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
2148 TCPSTAT_INC(tcps_sig_rcvbadsig);
2149 return (0);
2150 }
2151 TCPSTAT_INC(tcps_sig_rcvgoodsig);
2152 return (1);
2153 }
2154 #endif /* TCP_SIGNATURE */
2155
2156 static int
2157 sysctl_drop(SYSCTL_HANDLER_ARGS)
2158 {
2159 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
2160 struct sockaddr_storage addrs[2];
2161 struct inpcb *inp;
2162 struct tcpcb *tp;
2163 struct tcptw *tw;
2164 struct sockaddr_in *fin, *lin;
2165 #ifdef INET6
2166 struct sockaddr_in6 *fin6, *lin6;
2167 #endif
2168 int error;
2169
2170 inp = NULL;
2171 fin = lin = NULL;
2172 #ifdef INET6
2173 fin6 = lin6 = NULL;
2174 #endif
2175 error = 0;
2176
2177 if (req->oldptr != NULL || req->oldlen != 0)
2178 return (EINVAL);
2179 if (req->newptr == NULL)
2180 return (EPERM);
2181 if (req->newlen < sizeof(addrs))
2182 return (ENOMEM);
2183 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2184 if (error)
2185 return (error);
2186
2187 switch (addrs[0].ss_family) {
2188 #ifdef INET6
2189 case AF_INET6:
2190 fin6 = (struct sockaddr_in6 *)&addrs[0];
2191 lin6 = (struct sockaddr_in6 *)&addrs[1];
2192 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2193 lin6->sin6_len != sizeof(struct sockaddr_in6))
2194 return (EINVAL);
2195 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2196 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2197 return (EINVAL);
2198 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2199 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2200 fin = (struct sockaddr_in *)&addrs[0];
2201 lin = (struct sockaddr_in *)&addrs[1];
2202 break;
2203 }
2204 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2205 if (error)
2206 return (error);
2207 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2208 if (error)
2209 return (error);
2210 break;
2211 #endif
2212 #ifdef INET
2213 case AF_INET:
2214 fin = (struct sockaddr_in *)&addrs[0];
2215 lin = (struct sockaddr_in *)&addrs[1];
2216 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2217 lin->sin_len != sizeof(struct sockaddr_in))
2218 return (EINVAL);
2219 break;
2220 #endif
2221 default:
2222 return (EINVAL);
2223 }
2224 INP_INFO_WLOCK(&V_tcbinfo);
2225 switch (addrs[0].ss_family) {
2226 #ifdef INET6
2227 case AF_INET6:
2228 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
2229 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
2230 INPLOOKUP_WLOCKPCB, NULL);
2231 break;
2232 #endif
2233 #ifdef INET
2234 case AF_INET:
2235 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
2236 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
2237 break;
2238 #endif
2239 }
2240 if (inp != NULL) {
2241 if (inp->inp_flags & INP_TIMEWAIT) {
2242 /*
2243 * XXXRW: There currently exists a state where an
2244 * inpcb is present, but its timewait state has been
2245 * discarded. For now, don't allow dropping of this
2246 * type of inpcb.
2247 */
2248 tw = intotw(inp);
2249 if (tw != NULL)
2250 tcp_twclose(tw, 0);
2251 else
2252 INP_WUNLOCK(inp);
2253 } else if (!(inp->inp_flags & INP_DROPPED) &&
2254 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2255 tp = intotcpcb(inp);
2256 tp = tcp_drop(tp, ECONNABORTED);
2257 if (tp != NULL)
2258 INP_WUNLOCK(inp);
2259 } else
2260 INP_WUNLOCK(inp);
2261 } else
2262 error = ESRCH;
2263 INP_INFO_WUNLOCK(&V_tcbinfo);
2264 return (error);
2265 }
2266
2267 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2268 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2269 0, sysctl_drop, "", "Drop TCP connection");
2270
2271 /*
2272 * Generate a standardized TCP log line for use throughout the
2273 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2274 * allow use in the interrupt context.
2275 *
2276 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2277 * NB: The function may return NULL if memory allocation failed.
2278 *
2279 * Due to header inclusion and ordering limitations the struct ip
2280 * and ip6_hdr pointers have to be passed as void pointers.
2281 */
2282 char *
2283 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2284 const void *ip6hdr)
2285 {
2286
2287 /* Is logging enabled? */
2288 if (tcp_log_in_vain == 0)
2289 return (NULL);
2290
2291 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2292 }
2293
2294 char *
2295 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2296 const void *ip6hdr)
2297 {
2298
2299 /* Is logging enabled? */
2300 if (tcp_log_debug == 0)
2301 return (NULL);
2302
2303 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2304 }
2305
2306 static char *
2307 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2308 const void *ip6hdr)
2309 {
2310 char *s, *sp;
2311 size_t size;
2312 struct ip *ip;
2313 #ifdef INET6
2314 const struct ip6_hdr *ip6;
2315
2316 ip6 = (const struct ip6_hdr *)ip6hdr;
2317 #endif /* INET6 */
2318 ip = (struct ip *)ip4hdr;
2319
2320 /*
2321 * The log line looks like this:
2322 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2323 */
2324 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2325 sizeof(PRINT_TH_FLAGS) + 1 +
2326 #ifdef INET6
2327 2 * INET6_ADDRSTRLEN;
2328 #else
2329 2 * INET_ADDRSTRLEN;
2330 #endif /* INET6 */
2331
2332 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2333 if (s == NULL)
2334 return (NULL);
2335
2336 strcat(s, "TCP: [");
2337 sp = s + strlen(s);
2338
2339 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2340 inet_ntoa_r(inc->inc_faddr, sp);
2341 sp = s + strlen(s);
2342 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2343 sp = s + strlen(s);
2344 inet_ntoa_r(inc->inc_laddr, sp);
2345 sp = s + strlen(s);
2346 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2347 #ifdef INET6
2348 } else if (inc) {
2349 ip6_sprintf(sp, &inc->inc6_faddr);
2350 sp = s + strlen(s);
2351 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2352 sp = s + strlen(s);
2353 ip6_sprintf(sp, &inc->inc6_laddr);
2354 sp = s + strlen(s);
2355 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2356 } else if (ip6 && th) {
2357 ip6_sprintf(sp, &ip6->ip6_src);
2358 sp = s + strlen(s);
2359 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2360 sp = s + strlen(s);
2361 ip6_sprintf(sp, &ip6->ip6_dst);
2362 sp = s + strlen(s);
2363 sprintf(sp, "]:%i", ntohs(th->th_dport));
2364 #endif /* INET6 */
2365 #ifdef INET
2366 } else if (ip && th) {
2367 inet_ntoa_r(ip->ip_src, sp);
2368 sp = s + strlen(s);
2369 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2370 sp = s + strlen(s);
2371 inet_ntoa_r(ip->ip_dst, sp);
2372 sp = s + strlen(s);
2373 sprintf(sp, "]:%i", ntohs(th->th_dport));
2374 #endif /* INET */
2375 } else {
2376 free(s, M_TCPLOG);
2377 return (NULL);
2378 }
2379 sp = s + strlen(s);
2380 if (th)
2381 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2382 if (*(s + size - 1) != '\0')
2383 panic("%s: string too long", __func__);
2384 return (s);
2385 }
2386
2387 /*
2388 * A subroutine which makes it easy to track TCP state changes with DTrace.
2389 * This function shouldn't be called for t_state initializations that don't
2390 * correspond to actual TCP state transitions.
2391 */
2392 void
2393 tcp_state_change(struct tcpcb *tp, int newstate)
2394 {
2395 #if defined(KDTRACE_HOOKS)
2396 int pstate = tp->t_state;
2397 #endif
2398
2399 tp->t_state = newstate;
2400 TCP_PROBE6(state_change, NULL, tp, NULL, tp, NULL, pstate);
2401 }
Cache object: 8203f0720cd9038bc121f8cf130a72bf
|