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("$FreeBSD$"); 34 35 #include "opt_compat.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 #include "opt_ipsec.h" 39 #include "opt_tcpdebug.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/callout.h> 44 #include <sys/kernel.h> 45 #include <sys/sysctl.h> 46 #include <sys/jail.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #ifdef INET6 50 #include <sys/domain.h> 51 #endif 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/protosw.h> 57 #include <sys/random.h> 58 #include <sys/vimage.h> 59 60 #include <vm/uma.h> 61 62 #include <net/route.h> 63 #include <net/if.h> 64 65 #include <netinet/in.h> 66 #include <netinet/in_systm.h> 67 #include <netinet/ip.h> 68 #ifdef INET6 69 #include <netinet/ip6.h> 70 #endif 71 #include <netinet/in_pcb.h> 72 #ifdef INET6 73 #include <netinet6/in6_pcb.h> 74 #endif 75 #include <netinet/in_var.h> 76 #include <netinet/ip_var.h> 77 #ifdef INET6 78 #include <netinet6/ip6_var.h> 79 #include <netinet6/scope6_var.h> 80 #include <netinet6/nd6.h> 81 #endif 82 #include <netinet/ip_icmp.h> 83 #include <netinet/tcp.h> 84 #include <netinet/tcp_fsm.h> 85 #include <netinet/tcp_seq.h> 86 #include <netinet/tcp_timer.h> 87 #include <netinet/tcp_var.h> 88 #include <netinet/tcp_syncache.h> 89 #include <netinet/tcp_offload.h> 90 #ifdef INET6 91 #include <netinet6/tcp6_var.h> 92 #endif 93 #include <netinet/tcpip.h> 94 #ifdef TCPDEBUG 95 #include <netinet/tcp_debug.h> 96 #endif 97 #include <netinet/vinet.h> 98 #include <netinet6/ip6protosw.h> 99 #include <netinet6/vinet6.h> 100 101 #ifdef IPSEC 102 #include <netipsec/ipsec.h> 103 #include <netipsec/xform.h> 104 #ifdef INET6 105 #include <netipsec/ipsec6.h> 106 #endif 107 #include <netipsec/key.h> 108 #include <sys/syslog.h> 109 #endif /*IPSEC*/ 110 111 #include <machine/in_cksum.h> 112 #include <sys/md5.h> 113 114 #include <security/mac/mac_framework.h> 115 116 #ifdef VIMAGE_GLOBALS 117 int tcp_mssdflt; 118 #ifdef INET6 119 int tcp_v6mssdflt; 120 #endif 121 int tcp_minmss; 122 int tcp_do_rfc1323; 123 static int icmp_may_rst; 124 static int tcp_isn_reseed_interval; 125 static int tcp_inflight_enable; 126 static int tcp_inflight_rttthresh; 127 static int tcp_inflight_min; 128 static int tcp_inflight_max; 129 static int tcp_inflight_stab; 130 #endif 131 132 static int 133 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 134 { 135 INIT_VNET_INET(TD_TO_VNET(req->td)); 136 int error, new; 137 138 new = V_tcp_mssdflt; 139 error = sysctl_handle_int(oidp, &new, 0, req); 140 if (error == 0 && req->newptr) { 141 if (new < TCP_MINMSS) 142 error = EINVAL; 143 else 144 V_tcp_mssdflt = new; 145 } 146 return (error); 147 } 148 149 SYSCTL_V_PROC(V_NET, vnet_inet, _net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 150 CTLTYPE_INT|CTLFLAG_RW, tcp_mssdflt, 0, 151 &sysctl_net_inet_tcp_mss_check, "I", 152 "Default TCP Maximum Segment Size"); 153 154 #ifdef INET6 155 static int 156 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 157 { 158 INIT_VNET_INET(TD_TO_VNET(req->td)); 159 int error, new; 160 161 new = V_tcp_v6mssdflt; 162 error = sysctl_handle_int(oidp, &new, 0, req); 163 if (error == 0 && req->newptr) { 164 if (new < TCP_MINMSS) 165 error = EINVAL; 166 else 167 V_tcp_v6mssdflt = new; 168 } 169 return (error); 170 } 171 172 SYSCTL_V_PROC(V_NET, vnet_inet, _net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 173 CTLTYPE_INT|CTLFLAG_RW, tcp_v6mssdflt, 0, 174 &sysctl_net_inet_tcp_mss_v6_check, "I", 175 "Default TCP Maximum Segment Size for IPv6"); 176 #endif 177 178 /* 179 * Minimum MSS we accept and use. This prevents DoS attacks where 180 * we are forced to a ridiculous low MSS like 20 and send hundreds 181 * of packets instead of one. The effect scales with the available 182 * bandwidth and quickly saturates the CPU and network interface 183 * with packet generation and sending. Set to zero to disable MINMSS 184 * checking. This setting prevents us from sending too small packets. 185 */ 186 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, minmss, 187 CTLFLAG_RW, tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 188 189 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, 190 CTLFLAG_RW, tcp_do_rfc1323, 0, 191 "Enable rfc1323 (high performance TCP) extensions"); 192 193 static int tcp_log_debug = 0; 194 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 195 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 196 197 static int tcp_tcbhashsize = 0; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 199 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 200 201 static int do_tcpdrain = 1; 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 203 "Enable tcp_drain routine for extra help when low on mbufs"); 204 205 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, pcbcount, 206 CTLFLAG_RD, tcbinfo.ipi_count, 0, "Number of active PCBs"); 207 208 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, icmp_may_rst, 209 CTLFLAG_RW, icmp_may_rst, 0, 210 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 211 212 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp, OID_AUTO, isn_reseed_interval, 213 CTLFLAG_RW, tcp_isn_reseed_interval, 0, 214 "Seconds between reseeding of ISN secret"); 215 216 /* 217 * TCP bandwidth limiting sysctls. Note that the default lower bound of 218 * 1024 exists only for debugging. A good production default would be 219 * something like 6100. 220 */ 221 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, inflight, CTLFLAG_RW, 0, 222 "TCP inflight data limiting"); 223 224 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, enable, 225 CTLFLAG_RW, tcp_inflight_enable, 0, 226 "Enable automatic TCP inflight data limiting"); 227 228 static int tcp_inflight_debug = 0; 229 SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW, 230 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 231 232 SYSCTL_V_PROC(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, rttthresh, 233 CTLTYPE_INT|CTLFLAG_RW, tcp_inflight_rttthresh, 0, sysctl_msec_to_ticks, 234 "I", "RTT threshold below which inflight will deactivate itself"); 235 236 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, min, 237 CTLFLAG_RW, tcp_inflight_min, 0, "Lower-bound for TCP inflight window"); 238 239 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, max, 240 CTLFLAG_RW, tcp_inflight_max, 0, "Upper-bound for TCP inflight window"); 241 242 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_inflight, OID_AUTO, stab, 243 CTLFLAG_RW, tcp_inflight_stab, 0, 244 "Inflight Algorithm Stabilization 20 = 2 packets"); 245 246 #ifdef VIMAGE_GLOBALS 247 uma_zone_t sack_hole_zone; 248 #endif 249 250 static struct inpcb *tcp_notify(struct inpcb *, int); 251 static void tcp_isn_tick(void *); 252 253 /* 254 * Target size of TCP PCB hash tables. Must be a power of two. 255 * 256 * Note that this can be overridden by the kernel environment 257 * variable net.inet.tcp.tcbhashsize 258 */ 259 #ifndef TCBHASHSIZE 260 #define TCBHASHSIZE 512 261 #endif 262 263 /* 264 * XXX 265 * Callouts should be moved into struct tcp directly. They are currently 266 * separate because the tcpcb structure is exported to userland for sysctl 267 * parsing purposes, which do not know about callouts. 268 */ 269 struct tcpcb_mem { 270 struct tcpcb tcb; 271 struct tcp_timer tt; 272 }; 273 274 #ifdef VIMAGE_GLOBALS 275 static uma_zone_t tcpcb_zone; 276 #endif 277 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 278 struct callout isn_callout; 279 static struct mtx isn_mtx; 280 281 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 282 #define ISN_LOCK() mtx_lock(&isn_mtx) 283 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 284 285 /* 286 * TCP initialization. 287 */ 288 static void 289 tcp_zone_change(void *tag) 290 { 291 INIT_VNET_INET(curvnet); 292 293 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 294 uma_zone_set_max(V_tcpcb_zone, maxsockets); 295 tcp_tw_zone_change(); 296 } 297 298 static int 299 tcp_inpcb_init(void *mem, int size, int flags) 300 { 301 struct inpcb *inp = mem; 302 303 INP_LOCK_INIT(inp, "inp", "tcpinp"); 304 return (0); 305 } 306 307 void 308 tcp_init(void) 309 { 310 INIT_VNET_INET(curvnet); 311 int hashsize; 312 313 V_blackhole = 0; 314 V_tcp_delack_enabled = 1; 315 V_drop_synfin = 0; 316 V_tcp_do_rfc3042 = 1; 317 V_tcp_do_rfc3390 = 1; 318 V_tcp_do_ecn = 0; 319 V_tcp_ecn_maxretries = 1; 320 V_tcp_insecure_rst = 0; 321 V_tcp_do_autorcvbuf = 1; 322 V_tcp_autorcvbuf_inc = 16*1024; 323 V_tcp_autorcvbuf_max = 256*1024; 324 V_tcp_do_rfc3465 = 1; 325 V_tcp_abc_l_var = 2; 326 327 V_tcp_mssdflt = TCP_MSS; 328 #ifdef INET6 329 V_tcp_v6mssdflt = TCP6_MSS; 330 #endif 331 V_tcp_minmss = TCP_MINMSS; 332 V_tcp_do_rfc1323 = 1; 333 V_icmp_may_rst = 1; 334 V_tcp_isn_reseed_interval = 0; 335 V_tcp_inflight_enable = 1; 336 V_tcp_inflight_min = 6144; 337 V_tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 338 V_tcp_inflight_stab = 20; 339 340 V_path_mtu_discovery = 1; 341 V_ss_fltsz = 1; 342 V_ss_fltsz_local = 4; 343 V_tcp_do_newreno = 1; 344 V_tcp_do_tso = 1; 345 V_tcp_do_autosndbuf = 1; 346 V_tcp_autosndbuf_inc = 8*1024; 347 V_tcp_autosndbuf_max = 256*1024; 348 349 V_nolocaltimewait = 0; 350 351 V_tcp_do_sack = 1; 352 V_tcp_sack_maxholes = 128; 353 V_tcp_sack_globalmaxholes = 65536; 354 V_tcp_sack_globalholes = 0; 355 356 V_tcp_inflight_rttthresh = TCPTV_INFLIGHT_RTTTHRESH; 357 358 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 359 360 INP_INFO_LOCK_INIT(&V_tcbinfo, "tcp"); 361 LIST_INIT(&V_tcb); 362 #ifdef VIMAGE 363 V_tcbinfo.ipi_vnet = curvnet; 364 #endif 365 V_tcbinfo.ipi_listhead = &V_tcb; 366 hashsize = TCBHASHSIZE; 367 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 368 if (!powerof2(hashsize)) { 369 printf("WARNING: TCB hash size not a power of 2\n"); 370 hashsize = 512; /* safe default */ 371 } 372 V_tcbinfo.ipi_hashbase = hashinit(hashsize, M_PCB, 373 &V_tcbinfo.ipi_hashmask); 374 V_tcbinfo.ipi_porthashbase = hashinit(hashsize, M_PCB, 375 &V_tcbinfo.ipi_porthashmask); 376 V_tcbinfo.ipi_zone = uma_zcreate("tcp_inpcb", sizeof(struct inpcb), 377 NULL, NULL, tcp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 378 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 379 /* 380 * These have to be type stable for the benefit of the timers. 381 */ 382 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 383 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 384 uma_zone_set_max(V_tcpcb_zone, maxsockets); 385 tcp_tw_init(); 386 syncache_init(); 387 tcp_hc_init(); 388 tcp_reass_init(); 389 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 390 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 391 392 /* Skip initialization of globals for non-default instances. */ 393 if (!IS_DEFAULT_VNET(curvnet)) 394 return; 395 396 /* XXX virtualize those bellow? */ 397 tcp_delacktime = TCPTV_DELACK; 398 tcp_keepinit = TCPTV_KEEP_INIT; 399 tcp_keepidle = TCPTV_KEEP_IDLE; 400 tcp_keepintvl = TCPTV_KEEPINTVL; 401 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 402 tcp_msl = TCPTV_MSL; 403 tcp_rexmit_min = TCPTV_MIN; 404 if (tcp_rexmit_min < 1) 405 tcp_rexmit_min = 1; 406 tcp_rexmit_slop = TCPTV_CPU_VAR; 407 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 408 tcp_tcbhashsize = hashsize; 409 410 #ifdef INET6 411 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 412 #else /* INET6 */ 413 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 414 #endif /* INET6 */ 415 if (max_protohdr < TCP_MINPROTOHDR) 416 max_protohdr = TCP_MINPROTOHDR; 417 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 418 panic("tcp_init"); 419 #undef TCP_MINPROTOHDR 420 421 ISN_LOCK_INIT(); 422 callout_init(&isn_callout, CALLOUT_MPSAFE); 423 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 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 INIT_VNET_INET(curvnet); 435 436 tcp_tw_destroy(); 437 tcp_hc_destroy(); 438 syncache_destroy(); 439 440 /* XXX check that hashes are empty! */ 441 hashdestroy(V_tcbinfo.ipi_hashbase, M_PCB, 442 V_tcbinfo.ipi_hashmask); 443 hashdestroy(V_tcbinfo.ipi_porthashbase, M_PCB, 444 V_tcbinfo.ipi_porthashmask); 445 INP_INFO_LOCK_DESTROY(&V_tcbinfo); 446 } 447 #endif 448 449 void 450 tcp_fini(void *xtp) 451 { 452 453 callout_stop(&isn_callout); 454 } 455 456 /* 457 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 458 * tcp_template used to store this data in mbufs, but we now recopy it out 459 * of the tcpcb each time to conserve mbufs. 460 */ 461 void 462 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 463 { 464 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 465 466 INP_WLOCK_ASSERT(inp); 467 468 #ifdef INET6 469 if ((inp->inp_vflag & INP_IPV6) != 0) { 470 struct ip6_hdr *ip6; 471 472 ip6 = (struct ip6_hdr *)ip_ptr; 473 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 474 (inp->inp_flow & IPV6_FLOWINFO_MASK); 475 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 476 (IPV6_VERSION & IPV6_VERSION_MASK); 477 ip6->ip6_nxt = IPPROTO_TCP; 478 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 479 ip6->ip6_src = inp->in6p_laddr; 480 ip6->ip6_dst = inp->in6p_faddr; 481 } else 482 #endif 483 { 484 struct ip *ip; 485 486 ip = (struct ip *)ip_ptr; 487 ip->ip_v = IPVERSION; 488 ip->ip_hl = 5; 489 ip->ip_tos = inp->inp_ip_tos; 490 ip->ip_len = 0; 491 ip->ip_id = 0; 492 ip->ip_off = 0; 493 ip->ip_ttl = inp->inp_ip_ttl; 494 ip->ip_sum = 0; 495 ip->ip_p = IPPROTO_TCP; 496 ip->ip_src = inp->inp_laddr; 497 ip->ip_dst = inp->inp_faddr; 498 } 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 INIT_VNET_INET(curvnet); 547 int tlen; 548 int win = 0; 549 struct ip *ip; 550 struct tcphdr *nth; 551 #ifdef INET6 552 struct ip6_hdr *ip6; 553 int isipv6; 554 #endif /* INET6 */ 555 int ipflags = 0; 556 struct inpcb *inp; 557 558 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 559 560 #ifdef INET6 561 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 562 ip6 = ipgen; 563 #endif /* INET6 */ 564 ip = ipgen; 565 566 if (tp != NULL) { 567 inp = tp->t_inpcb; 568 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 569 INP_WLOCK_ASSERT(inp); 570 } else 571 inp = NULL; 572 573 if (tp != NULL) { 574 if (!(flags & TH_RST)) { 575 win = sbspace(&inp->inp_socket->so_rcv); 576 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 577 win = (long)TCP_MAXWIN << tp->rcv_scale; 578 } 579 } 580 if (m == NULL) { 581 m = m_gethdr(M_DONTWAIT, MT_DATA); 582 if (m == NULL) 583 return; 584 tlen = 0; 585 m->m_data += max_linkhdr; 586 #ifdef INET6 587 if (isipv6) { 588 bcopy((caddr_t)ip6, mtod(m, caddr_t), 589 sizeof(struct ip6_hdr)); 590 ip6 = mtod(m, struct ip6_hdr *); 591 nth = (struct tcphdr *)(ip6 + 1); 592 } else 593 #endif /* INET6 */ 594 { 595 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 596 ip = mtod(m, struct ip *); 597 nth = (struct tcphdr *)(ip + 1); 598 } 599 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 600 flags = TH_ACK; 601 } else { 602 /* 603 * reuse the mbuf. 604 * XXX MRT We inherrit the FIB, which is lucky. 605 */ 606 m_freem(m->m_next); 607 m->m_next = NULL; 608 m->m_data = (caddr_t)ipgen; 609 /* m_len is set later */ 610 tlen = 0; 611 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 612 #ifdef INET6 613 if (isipv6) { 614 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 615 nth = (struct tcphdr *)(ip6 + 1); 616 } else 617 #endif /* INET6 */ 618 { 619 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 620 nth = (struct tcphdr *)(ip + 1); 621 } 622 if (th != nth) { 623 /* 624 * this is usually a case when an extension header 625 * exists between the IPv6 header and the 626 * TCP header. 627 */ 628 nth->th_sport = th->th_sport; 629 nth->th_dport = th->th_dport; 630 } 631 xchg(nth->th_dport, nth->th_sport, uint16_t); 632 #undef xchg 633 } 634 #ifdef INET6 635 if (isipv6) { 636 ip6->ip6_flow = 0; 637 ip6->ip6_vfc = IPV6_VERSION; 638 ip6->ip6_nxt = IPPROTO_TCP; 639 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 640 tlen)); 641 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 642 } else 643 #endif 644 { 645 tlen += sizeof (struct tcpiphdr); 646 ip->ip_len = tlen; 647 ip->ip_ttl = V_ip_defttl; 648 if (V_path_mtu_discovery) 649 ip->ip_off |= IP_DF; 650 } 651 m->m_len = tlen; 652 m->m_pkthdr.len = tlen; 653 m->m_pkthdr.rcvif = NULL; 654 #ifdef MAC 655 if (inp != NULL) { 656 /* 657 * Packet is associated with a socket, so allow the 658 * label of the response to reflect the socket label. 659 */ 660 INP_WLOCK_ASSERT(inp); 661 mac_inpcb_create_mbuf(inp, m); 662 } else { 663 /* 664 * Packet is not associated with a socket, so possibly 665 * update the label in place. 666 */ 667 mac_netinet_tcp_reply(m); 668 } 669 #endif 670 nth->th_seq = htonl(seq); 671 nth->th_ack = htonl(ack); 672 nth->th_x2 = 0; 673 nth->th_off = sizeof (struct tcphdr) >> 2; 674 nth->th_flags = flags; 675 if (tp != NULL) 676 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 677 else 678 nth->th_win = htons((u_short)win); 679 nth->th_urp = 0; 680 #ifdef INET6 681 if (isipv6) { 682 nth->th_sum = 0; 683 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 684 sizeof(struct ip6_hdr), 685 tlen - sizeof(struct ip6_hdr)); 686 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 687 NULL, NULL); 688 } else 689 #endif /* INET6 */ 690 { 691 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 692 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 693 m->m_pkthdr.csum_flags = CSUM_TCP; 694 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 695 } 696 #ifdef TCPDEBUG 697 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 698 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 699 #endif 700 #ifdef INET6 701 if (isipv6) 702 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 703 else 704 #endif /* INET6 */ 705 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 706 } 707 708 /* 709 * Create a new TCP control block, making an 710 * empty reassembly queue and hooking it to the argument 711 * protocol control block. The `inp' parameter must have 712 * come from the zone allocator set up in tcp_init(). 713 */ 714 struct tcpcb * 715 tcp_newtcpcb(struct inpcb *inp) 716 { 717 INIT_VNET_INET(inp->inp_vnet); 718 struct tcpcb_mem *tm; 719 struct tcpcb *tp; 720 #ifdef INET6 721 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 722 #endif /* INET6 */ 723 724 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 725 if (tm == NULL) 726 return (NULL); 727 tp = &tm->tcb; 728 #ifdef VIMAGE 729 tp->t_vnet = inp->inp_vnet; 730 #endif 731 tp->t_timers = &tm->tt; 732 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 733 tp->t_maxseg = tp->t_maxopd = 734 #ifdef INET6 735 isipv6 ? V_tcp_v6mssdflt : 736 #endif /* INET6 */ 737 V_tcp_mssdflt; 738 739 /* Set up our timeouts. */ 740 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 741 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 742 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 743 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 744 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 745 746 if (V_tcp_do_rfc1323) 747 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 748 if (V_tcp_do_sack) 749 tp->t_flags |= TF_SACK_PERMIT; 750 TAILQ_INIT(&tp->snd_holes); 751 tp->t_inpcb = inp; /* XXX */ 752 /* 753 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 754 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 755 * reasonable initial retransmit time. 756 */ 757 tp->t_srtt = TCPTV_SRTTBASE; 758 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 759 tp->t_rttmin = tcp_rexmit_min; 760 tp->t_rxtcur = TCPTV_RTOBASE; 761 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 762 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 763 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 764 tp->t_rcvtime = ticks; 765 tp->t_bw_rtttime = ticks; 766 /* 767 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 768 * because the socket may be bound to an IPv6 wildcard address, 769 * which may match an IPv4-mapped IPv6 address. 770 */ 771 inp->inp_ip_ttl = V_ip_defttl; 772 inp->inp_ppcb = tp; 773 return (tp); /* XXX */ 774 } 775 776 /* 777 * Drop a TCP connection, reporting 778 * the specified error. If connection is synchronized, 779 * then send a RST to peer. 780 */ 781 struct tcpcb * 782 tcp_drop(struct tcpcb *tp, int errno) 783 { 784 INIT_VNET_INET(tp->t_inpcb->inp_vnet); 785 struct socket *so = tp->t_inpcb->inp_socket; 786 787 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 788 INP_WLOCK_ASSERT(tp->t_inpcb); 789 790 if (TCPS_HAVERCVDSYN(tp->t_state)) { 791 tp->t_state = TCPS_CLOSED; 792 (void) tcp_output_reset(tp); 793 TCPSTAT_INC(tcps_drops); 794 } else 795 TCPSTAT_INC(tcps_conndrops); 796 if (errno == ETIMEDOUT && tp->t_softerror) 797 errno = tp->t_softerror; 798 so->so_error = errno; 799 return (tcp_close(tp)); 800 } 801 802 void 803 tcp_discardcb(struct tcpcb *tp) 804 { 805 INIT_VNET_INET(tp->t_vnet); 806 struct tseg_qent *q; 807 struct inpcb *inp = tp->t_inpcb; 808 struct socket *so = inp->inp_socket; 809 #ifdef INET6 810 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 811 #endif /* INET6 */ 812 813 INP_WLOCK_ASSERT(inp); 814 815 /* 816 * Make sure that all of our timers are stopped before we 817 * delete the PCB. 818 */ 819 callout_stop(&tp->t_timers->tt_rexmt); 820 callout_stop(&tp->t_timers->tt_persist); 821 callout_stop(&tp->t_timers->tt_keep); 822 callout_stop(&tp->t_timers->tt_2msl); 823 callout_stop(&tp->t_timers->tt_delack); 824 825 /* 826 * If we got enough samples through the srtt filter, 827 * save the rtt and rttvar in the routing entry. 828 * 'Enough' is arbitrarily defined as 4 rtt samples. 829 * 4 samples is enough for the srtt filter to converge 830 * to within enough % of the correct value; fewer samples 831 * and we could save a bogus rtt. The danger is not high 832 * as tcp quickly recovers from everything. 833 * XXX: Works very well but needs some more statistics! 834 */ 835 if (tp->t_rttupdated >= 4) { 836 struct hc_metrics_lite metrics; 837 u_long ssthresh; 838 839 bzero(&metrics, sizeof(metrics)); 840 /* 841 * Update the ssthresh always when the conditions below 842 * are satisfied. This gives us better new start value 843 * for the congestion avoidance for new connections. 844 * ssthresh is only set if packet loss occured on a session. 845 * 846 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 847 * being torn down. Ideally this code would not use 'so'. 848 */ 849 ssthresh = tp->snd_ssthresh; 850 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 851 /* 852 * convert the limit from user data bytes to 853 * packets then to packet data bytes. 854 */ 855 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 856 if (ssthresh < 2) 857 ssthresh = 2; 858 ssthresh *= (u_long)(tp->t_maxseg + 859 #ifdef INET6 860 (isipv6 ? sizeof (struct ip6_hdr) + 861 sizeof (struct tcphdr) : 862 #endif 863 sizeof (struct tcpiphdr) 864 #ifdef INET6 865 ) 866 #endif 867 ); 868 } else 869 ssthresh = 0; 870 metrics.rmx_ssthresh = ssthresh; 871 872 metrics.rmx_rtt = tp->t_srtt; 873 metrics.rmx_rttvar = tp->t_rttvar; 874 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 875 metrics.rmx_bandwidth = tp->snd_bandwidth; 876 metrics.rmx_cwnd = tp->snd_cwnd; 877 metrics.rmx_sendpipe = 0; 878 metrics.rmx_recvpipe = 0; 879 880 tcp_hc_update(&inp->inp_inc, &metrics); 881 } 882 883 /* free the reassembly queue, if any */ 884 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 885 LIST_REMOVE(q, tqe_q); 886 m_freem(q->tqe_m); 887 uma_zfree(V_tcp_reass_zone, q); 888 tp->t_segqlen--; 889 V_tcp_reass_qsize--; 890 } 891 /* Disconnect offload device, if any. */ 892 tcp_offload_detach(tp); 893 894 tcp_free_sackholes(tp); 895 inp->inp_ppcb = NULL; 896 tp->t_inpcb = NULL; 897 uma_zfree(V_tcpcb_zone, tp); 898 } 899 900 /* 901 * Attempt to close a TCP control block, marking it as dropped, and freeing 902 * the socket if we hold the only reference. 903 */ 904 struct tcpcb * 905 tcp_close(struct tcpcb *tp) 906 { 907 INIT_VNET_INET(tp->t_inpcb->inp_vnet); 908 struct inpcb *inp = tp->t_inpcb; 909 struct socket *so; 910 911 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 912 INP_WLOCK_ASSERT(inp); 913 914 /* Notify any offload devices of listener close */ 915 if (tp->t_state == TCPS_LISTEN) 916 tcp_offload_listen_close(tp); 917 in_pcbdrop(inp); 918 TCPSTAT_INC(tcps_closed); 919 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 920 so = inp->inp_socket; 921 soisdisconnected(so); 922 if (inp->inp_flags & INP_SOCKREF) { 923 KASSERT(so->so_state & SS_PROTOREF, 924 ("tcp_close: !SS_PROTOREF")); 925 inp->inp_flags &= ~INP_SOCKREF; 926 INP_WUNLOCK(inp); 927 ACCEPT_LOCK(); 928 SOCK_LOCK(so); 929 so->so_state &= ~SS_PROTOREF; 930 sofree(so); 931 return (NULL); 932 } 933 return (tp); 934 } 935 936 void 937 tcp_drain(void) 938 { 939 VNET_ITERATOR_DECL(vnet_iter); 940 941 if (!do_tcpdrain) 942 return; 943 944 VNET_LIST_RLOCK(); 945 VNET_FOREACH(vnet_iter) { 946 CURVNET_SET(vnet_iter); 947 INIT_VNET_INET(vnet_iter); 948 struct inpcb *inpb; 949 struct tcpcb *tcpb; 950 struct tseg_qent *te; 951 952 /* 953 * Walk the tcpbs, if existing, and flush the reassembly queue, 954 * if there is one... 955 * XXX: The "Net/3" implementation doesn't imply that the TCP 956 * reassembly queue should be flushed, but in a situation 957 * where we're really low on mbufs, this is potentially 958 * usefull. 959 */ 960 INP_INFO_RLOCK(&V_tcbinfo); 961 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 962 if (inpb->inp_flags & INP_TIMEWAIT) 963 continue; 964 INP_WLOCK(inpb); 965 if ((tcpb = intotcpcb(inpb)) != NULL) { 966 while ((te = LIST_FIRST(&tcpb->t_segq)) 967 != NULL) { 968 LIST_REMOVE(te, tqe_q); 969 m_freem(te->tqe_m); 970 uma_zfree(V_tcp_reass_zone, te); 971 tcpb->t_segqlen--; 972 V_tcp_reass_qsize--; 973 } 974 tcp_clean_sackreport(tcpb); 975 } 976 INP_WUNLOCK(inpb); 977 } 978 INP_INFO_RUNLOCK(&V_tcbinfo); 979 CURVNET_RESTORE(); 980 } 981 VNET_LIST_RUNLOCK(); 982 } 983 984 /* 985 * Notify a tcp user of an asynchronous error; 986 * store error as soft error, but wake up user 987 * (for now, won't do anything until can select for soft error). 988 * 989 * Do not wake up user since there currently is no mechanism for 990 * reporting soft errors (yet - a kqueue filter may be added). 991 */ 992 static struct inpcb * 993 tcp_notify(struct inpcb *inp, int error) 994 { 995 struct tcpcb *tp; 996 #ifdef INVARIANTS 997 INIT_VNET_INET(inp->inp_vnet); /* V_tcbinfo WLOCK ASSERT */ 998 #endif 999 1000 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1001 INP_WLOCK_ASSERT(inp); 1002 1003 if ((inp->inp_flags & INP_TIMEWAIT) || 1004 (inp->inp_flags & INP_DROPPED)) 1005 return (inp); 1006 1007 tp = intotcpcb(inp); 1008 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1009 1010 /* 1011 * Ignore some errors if we are hooked up. 1012 * If connection hasn't completed, has retransmitted several times, 1013 * and receives a second error, give up now. This is better 1014 * than waiting a long time to establish a connection that 1015 * can never complete. 1016 */ 1017 if (tp->t_state == TCPS_ESTABLISHED && 1018 (error == EHOSTUNREACH || error == ENETUNREACH || 1019 error == EHOSTDOWN)) { 1020 return (inp); 1021 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1022 tp->t_softerror) { 1023 tp = tcp_drop(tp, error); 1024 if (tp != NULL) 1025 return (inp); 1026 else 1027 return (NULL); 1028 } else { 1029 tp->t_softerror = error; 1030 return (inp); 1031 } 1032 #if 0 1033 wakeup( &so->so_timeo); 1034 sorwakeup(so); 1035 sowwakeup(so); 1036 #endif 1037 } 1038 1039 static int 1040 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1041 { 1042 INIT_VNET_INET(curvnet); 1043 int error, i, m, n, pcb_count; 1044 struct inpcb *inp, **inp_list; 1045 inp_gen_t gencnt; 1046 struct xinpgen xig; 1047 1048 /* 1049 * The process of preparing the TCB list is too time-consuming and 1050 * resource-intensive to repeat twice on every request. 1051 */ 1052 if (req->oldptr == NULL) { 1053 m = syncache_pcbcount(); 1054 n = V_tcbinfo.ipi_count; 1055 req->oldidx = 2 * (sizeof xig) 1056 + ((m + n) + n/8) * sizeof(struct xtcpcb); 1057 return (0); 1058 } 1059 1060 if (req->newptr != NULL) 1061 return (EPERM); 1062 1063 /* 1064 * OK, now we're committed to doing something. 1065 */ 1066 INP_INFO_RLOCK(&V_tcbinfo); 1067 gencnt = V_tcbinfo.ipi_gencnt; 1068 n = V_tcbinfo.ipi_count; 1069 INP_INFO_RUNLOCK(&V_tcbinfo); 1070 1071 m = syncache_pcbcount(); 1072 1073 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1074 + (n + m) * sizeof(struct xtcpcb)); 1075 if (error != 0) 1076 return (error); 1077 1078 xig.xig_len = sizeof xig; 1079 xig.xig_count = n + m; 1080 xig.xig_gen = gencnt; 1081 xig.xig_sogen = so_gencnt; 1082 error = SYSCTL_OUT(req, &xig, sizeof xig); 1083 if (error) 1084 return (error); 1085 1086 error = syncache_pcblist(req, m, &pcb_count); 1087 if (error) 1088 return (error); 1089 1090 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1091 if (inp_list == NULL) 1092 return (ENOMEM); 1093 1094 INP_INFO_RLOCK(&V_tcbinfo); 1095 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1096 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1097 INP_RLOCK(inp); 1098 if (inp->inp_gencnt <= gencnt) { 1099 /* 1100 * XXX: This use of cr_cansee(), introduced with 1101 * TCP state changes, is not quite right, but for 1102 * now, better than nothing. 1103 */ 1104 if (inp->inp_flags & INP_TIMEWAIT) { 1105 if (intotw(inp) != NULL) 1106 error = cr_cansee(req->td->td_ucred, 1107 intotw(inp)->tw_cred); 1108 else 1109 error = EINVAL; /* Skip this inp. */ 1110 } else 1111 error = cr_canseeinpcb(req->td->td_ucred, inp); 1112 if (error == 0) 1113 inp_list[i++] = inp; 1114 } 1115 INP_RUNLOCK(inp); 1116 } 1117 INP_INFO_RUNLOCK(&V_tcbinfo); 1118 n = i; 1119 1120 error = 0; 1121 for (i = 0; i < n; i++) { 1122 inp = inp_list[i]; 1123 INP_RLOCK(inp); 1124 if (inp->inp_gencnt <= gencnt) { 1125 struct xtcpcb xt; 1126 void *inp_ppcb; 1127 1128 bzero(&xt, sizeof(xt)); 1129 xt.xt_len = sizeof xt; 1130 /* XXX should avoid extra copy */ 1131 bcopy(inp, &xt.xt_inp, sizeof *inp); 1132 inp_ppcb = inp->inp_ppcb; 1133 if (inp_ppcb == NULL) 1134 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1135 else if (inp->inp_flags & INP_TIMEWAIT) { 1136 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1137 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1138 } else 1139 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1140 if (inp->inp_socket != NULL) 1141 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1142 else { 1143 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1144 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1145 } 1146 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1147 INP_RUNLOCK(inp); 1148 error = SYSCTL_OUT(req, &xt, sizeof xt); 1149 } else 1150 INP_RUNLOCK(inp); 1151 1152 } 1153 if (!error) { 1154 /* 1155 * Give the user an updated idea of our state. 1156 * If the generation differs from what we told 1157 * her before, she knows that something happened 1158 * while we were processing this request, and it 1159 * might be necessary to retry. 1160 */ 1161 INP_INFO_RLOCK(&V_tcbinfo); 1162 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1163 xig.xig_sogen = so_gencnt; 1164 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1165 INP_INFO_RUNLOCK(&V_tcbinfo); 1166 error = SYSCTL_OUT(req, &xig, sizeof xig); 1167 } 1168 free(inp_list, M_TEMP); 1169 return (error); 1170 } 1171 1172 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1173 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1174 1175 static int 1176 tcp_getcred(SYSCTL_HANDLER_ARGS) 1177 { 1178 INIT_VNET_INET(curvnet); 1179 struct xucred xuc; 1180 struct sockaddr_in addrs[2]; 1181 struct inpcb *inp; 1182 int error; 1183 1184 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1185 if (error) 1186 return (error); 1187 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1188 if (error) 1189 return (error); 1190 INP_INFO_RLOCK(&V_tcbinfo); 1191 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1192 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1193 if (inp != NULL) { 1194 INP_RLOCK(inp); 1195 INP_INFO_RUNLOCK(&V_tcbinfo); 1196 if (inp->inp_socket == NULL) 1197 error = ENOENT; 1198 if (error == 0) 1199 error = cr_canseeinpcb(req->td->td_ucred, inp); 1200 if (error == 0) 1201 cru2x(inp->inp_cred, &xuc); 1202 INP_RUNLOCK(inp); 1203 } else { 1204 INP_INFO_RUNLOCK(&V_tcbinfo); 1205 error = ENOENT; 1206 } 1207 if (error == 0) 1208 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1209 return (error); 1210 } 1211 1212 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1213 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1214 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1215 1216 #ifdef INET6 1217 static int 1218 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1219 { 1220 INIT_VNET_INET(curvnet); 1221 INIT_VNET_INET6(curvnet); 1222 struct xucred xuc; 1223 struct sockaddr_in6 addrs[2]; 1224 struct inpcb *inp; 1225 int error, mapped = 0; 1226 1227 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1228 if (error) 1229 return (error); 1230 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1231 if (error) 1232 return (error); 1233 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1234 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1235 return (error); 1236 } 1237 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1238 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1239 mapped = 1; 1240 else 1241 return (EINVAL); 1242 } 1243 1244 INP_INFO_RLOCK(&V_tcbinfo); 1245 if (mapped == 1) 1246 inp = in_pcblookup_hash(&V_tcbinfo, 1247 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1248 addrs[1].sin6_port, 1249 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1250 addrs[0].sin6_port, 1251 0, NULL); 1252 else 1253 inp = in6_pcblookup_hash(&V_tcbinfo, 1254 &addrs[1].sin6_addr, addrs[1].sin6_port, 1255 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1256 if (inp != NULL) { 1257 INP_RLOCK(inp); 1258 INP_INFO_RUNLOCK(&V_tcbinfo); 1259 if (inp->inp_socket == NULL) 1260 error = ENOENT; 1261 if (error == 0) 1262 error = cr_canseeinpcb(req->td->td_ucred, inp); 1263 if (error == 0) 1264 cru2x(inp->inp_cred, &xuc); 1265 INP_RUNLOCK(inp); 1266 } else { 1267 INP_INFO_RUNLOCK(&V_tcbinfo); 1268 error = ENOENT; 1269 } 1270 if (error == 0) 1271 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1272 return (error); 1273 } 1274 1275 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1276 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1277 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1278 #endif 1279 1280 1281 void 1282 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1283 { 1284 INIT_VNET_INET(curvnet); 1285 struct ip *ip = vip; 1286 struct tcphdr *th; 1287 struct in_addr faddr; 1288 struct inpcb *inp; 1289 struct tcpcb *tp; 1290 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1291 struct icmp *icp; 1292 struct in_conninfo inc; 1293 tcp_seq icmp_tcp_seq; 1294 int mtu; 1295 1296 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1297 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1298 return; 1299 1300 if (cmd == PRC_MSGSIZE) 1301 notify = tcp_mtudisc; 1302 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1303 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1304 notify = tcp_drop_syn_sent; 1305 /* 1306 * Redirects don't need to be handled up here. 1307 */ 1308 else if (PRC_IS_REDIRECT(cmd)) 1309 return; 1310 /* 1311 * Source quench is depreciated. 1312 */ 1313 else if (cmd == PRC_QUENCH) 1314 return; 1315 /* 1316 * Hostdead is ugly because it goes linearly through all PCBs. 1317 * XXX: We never get this from ICMP, otherwise it makes an 1318 * excellent DoS attack on machines with many connections. 1319 */ 1320 else if (cmd == PRC_HOSTDEAD) 1321 ip = NULL; 1322 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1323 return; 1324 if (ip != NULL) { 1325 icp = (struct icmp *)((caddr_t)ip 1326 - offsetof(struct icmp, icmp_ip)); 1327 th = (struct tcphdr *)((caddr_t)ip 1328 + (ip->ip_hl << 2)); 1329 INP_INFO_WLOCK(&V_tcbinfo); 1330 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1331 ip->ip_src, th->th_sport, 0, NULL); 1332 if (inp != NULL) { 1333 INP_WLOCK(inp); 1334 if (!(inp->inp_flags & INP_TIMEWAIT) && 1335 !(inp->inp_flags & INP_DROPPED) && 1336 !(inp->inp_socket == NULL)) { 1337 icmp_tcp_seq = htonl(th->th_seq); 1338 tp = intotcpcb(inp); 1339 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1340 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1341 if (cmd == PRC_MSGSIZE) { 1342 /* 1343 * MTU discovery: 1344 * If we got a needfrag set the MTU 1345 * in the route to the suggested new 1346 * value (if given) and then notify. 1347 */ 1348 bzero(&inc, sizeof(inc)); 1349 inc.inc_faddr = faddr; 1350 inc.inc_fibnum = 1351 inp->inp_inc.inc_fibnum; 1352 1353 mtu = ntohs(icp->icmp_nextmtu); 1354 /* 1355 * If no alternative MTU was 1356 * proposed, try the next smaller 1357 * one. ip->ip_len has already 1358 * been swapped in icmp_input(). 1359 */ 1360 if (!mtu) 1361 mtu = ip_next_mtu(ip->ip_len, 1362 1); 1363 if (mtu < max(296, V_tcp_minmss 1364 + sizeof(struct tcpiphdr))) 1365 mtu = 0; 1366 if (!mtu) 1367 mtu = V_tcp_mssdflt 1368 + sizeof(struct tcpiphdr); 1369 /* 1370 * Only cache the the MTU if it 1371 * is smaller than the interface 1372 * or route MTU. tcp_mtudisc() 1373 * will do right thing by itself. 1374 */ 1375 if (mtu <= tcp_maxmtu(&inc, NULL)) 1376 tcp_hc_updatemtu(&inc, mtu); 1377 } 1378 1379 inp = (*notify)(inp, inetctlerrmap[cmd]); 1380 } 1381 } 1382 if (inp != NULL) 1383 INP_WUNLOCK(inp); 1384 } else { 1385 bzero(&inc, sizeof(inc)); 1386 inc.inc_fport = th->th_dport; 1387 inc.inc_lport = th->th_sport; 1388 inc.inc_faddr = faddr; 1389 inc.inc_laddr = ip->ip_src; 1390 syncache_unreach(&inc, th); 1391 } 1392 INP_INFO_WUNLOCK(&V_tcbinfo); 1393 } else 1394 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1395 } 1396 1397 #ifdef INET6 1398 void 1399 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1400 { 1401 INIT_VNET_INET(curvnet); 1402 struct tcphdr th; 1403 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1404 struct ip6_hdr *ip6; 1405 struct mbuf *m; 1406 struct ip6ctlparam *ip6cp = NULL; 1407 const struct sockaddr_in6 *sa6_src = NULL; 1408 int off; 1409 struct tcp_portonly { 1410 u_int16_t th_sport; 1411 u_int16_t th_dport; 1412 } *thp; 1413 1414 if (sa->sa_family != AF_INET6 || 1415 sa->sa_len != sizeof(struct sockaddr_in6)) 1416 return; 1417 1418 if (cmd == PRC_MSGSIZE) 1419 notify = tcp_mtudisc; 1420 else if (!PRC_IS_REDIRECT(cmd) && 1421 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1422 return; 1423 /* Source quench is depreciated. */ 1424 else if (cmd == PRC_QUENCH) 1425 return; 1426 1427 /* if the parameter is from icmp6, decode it. */ 1428 if (d != NULL) { 1429 ip6cp = (struct ip6ctlparam *)d; 1430 m = ip6cp->ip6c_m; 1431 ip6 = ip6cp->ip6c_ip6; 1432 off = ip6cp->ip6c_off; 1433 sa6_src = ip6cp->ip6c_src; 1434 } else { 1435 m = NULL; 1436 ip6 = NULL; 1437 off = 0; /* fool gcc */ 1438 sa6_src = &sa6_any; 1439 } 1440 1441 if (ip6 != NULL) { 1442 struct in_conninfo inc; 1443 /* 1444 * XXX: We assume that when IPV6 is non NULL, 1445 * M and OFF are valid. 1446 */ 1447 1448 /* check if we can safely examine src and dst ports */ 1449 if (m->m_pkthdr.len < off + sizeof(*thp)) 1450 return; 1451 1452 bzero(&th, sizeof(th)); 1453 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1454 1455 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1456 (struct sockaddr *)ip6cp->ip6c_src, 1457 th.th_sport, cmd, NULL, notify); 1458 1459 bzero(&inc, sizeof(inc)); 1460 inc.inc_fport = th.th_dport; 1461 inc.inc_lport = th.th_sport; 1462 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1463 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1464 inc.inc_flags |= INC_ISIPV6; 1465 INP_INFO_WLOCK(&V_tcbinfo); 1466 syncache_unreach(&inc, &th); 1467 INP_INFO_WUNLOCK(&V_tcbinfo); 1468 } else 1469 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1470 0, cmd, NULL, notify); 1471 } 1472 #endif /* INET6 */ 1473 1474 1475 /* 1476 * Following is where TCP initial sequence number generation occurs. 1477 * 1478 * There are two places where we must use initial sequence numbers: 1479 * 1. In SYN-ACK packets. 1480 * 2. In SYN packets. 1481 * 1482 * All ISNs for SYN-ACK packets are generated by the syncache. See 1483 * tcp_syncache.c for details. 1484 * 1485 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1486 * depends on this property. In addition, these ISNs should be 1487 * unguessable so as to prevent connection hijacking. To satisfy 1488 * the requirements of this situation, the algorithm outlined in 1489 * RFC 1948 is used, with only small modifications. 1490 * 1491 * Implementation details: 1492 * 1493 * Time is based off the system timer, and is corrected so that it 1494 * increases by one megabyte per second. This allows for proper 1495 * recycling on high speed LANs while still leaving over an hour 1496 * before rollover. 1497 * 1498 * As reading the *exact* system time is too expensive to be done 1499 * whenever setting up a TCP connection, we increment the time 1500 * offset in two ways. First, a small random positive increment 1501 * is added to isn_offset for each connection that is set up. 1502 * Second, the function tcp_isn_tick fires once per clock tick 1503 * and increments isn_offset as necessary so that sequence numbers 1504 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1505 * random positive increments serve only to ensure that the same 1506 * exact sequence number is never sent out twice (as could otherwise 1507 * happen when a port is recycled in less than the system tick 1508 * interval.) 1509 * 1510 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1511 * between seeding of isn_secret. This is normally set to zero, 1512 * as reseeding should not be necessary. 1513 * 1514 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1515 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1516 * general, this means holding an exclusive (write) lock. 1517 */ 1518 1519 #define ISN_BYTES_PER_SECOND 1048576 1520 #define ISN_STATIC_INCREMENT 4096 1521 #define ISN_RANDOM_INCREMENT (4096 - 1) 1522 1523 #ifdef VIMAGE_GLOBALS 1524 static u_char isn_secret[32]; 1525 static int isn_last_reseed; 1526 static u_int32_t isn_offset, isn_offset_old; 1527 #endif 1528 1529 tcp_seq 1530 tcp_new_isn(struct tcpcb *tp) 1531 { 1532 INIT_VNET_INET(tp->t_vnet); 1533 MD5_CTX isn_ctx; 1534 u_int32_t md5_buffer[4]; 1535 tcp_seq new_isn; 1536 1537 INP_WLOCK_ASSERT(tp->t_inpcb); 1538 1539 ISN_LOCK(); 1540 /* Seed if this is the first use, reseed if requested. */ 1541 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1542 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1543 < (u_int)ticks))) { 1544 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1545 V_isn_last_reseed = ticks; 1546 } 1547 1548 /* Compute the md5 hash and return the ISN. */ 1549 MD5Init(&isn_ctx); 1550 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1551 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1552 #ifdef INET6 1553 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1554 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1555 sizeof(struct in6_addr)); 1556 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1557 sizeof(struct in6_addr)); 1558 } else 1559 #endif 1560 { 1561 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1562 sizeof(struct in_addr)); 1563 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1564 sizeof(struct in_addr)); 1565 } 1566 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1567 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1568 new_isn = (tcp_seq) md5_buffer[0]; 1569 V_isn_offset += ISN_STATIC_INCREMENT + 1570 (arc4random() & ISN_RANDOM_INCREMENT); 1571 new_isn += V_isn_offset; 1572 ISN_UNLOCK(); 1573 return (new_isn); 1574 } 1575 1576 /* 1577 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1578 * to keep time flowing at a relatively constant rate. If the random 1579 * increments have already pushed us past the projected offset, do nothing. 1580 */ 1581 static void 1582 tcp_isn_tick(void *xtp) 1583 { 1584 VNET_ITERATOR_DECL(vnet_iter); 1585 u_int32_t projected_offset; 1586 1587 VNET_LIST_RLOCK(); 1588 ISN_LOCK(); 1589 VNET_FOREACH(vnet_iter) { 1590 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 1591 INIT_VNET_INET(curvnet); 1592 projected_offset = 1593 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100; 1594 1595 if (SEQ_GT(projected_offset, V_isn_offset)) 1596 V_isn_offset = projected_offset; 1597 1598 V_isn_offset_old = V_isn_offset; 1599 CURVNET_RESTORE(); 1600 } 1601 ISN_UNLOCK(); 1602 VNET_LIST_RUNLOCK(); 1603 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 1604 } 1605 1606 /* 1607 * When a specific ICMP unreachable message is received and the 1608 * connection state is SYN-SENT, drop the connection. This behavior 1609 * is controlled by the icmp_may_rst sysctl. 1610 */ 1611 struct inpcb * 1612 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1613 { 1614 #ifdef INVARIANTS 1615 INIT_VNET_INET(inp->inp_vnet); 1616 #endif 1617 struct tcpcb *tp; 1618 1619 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1620 INP_WLOCK_ASSERT(inp); 1621 1622 if ((inp->inp_flags & INP_TIMEWAIT) || 1623 (inp->inp_flags & INP_DROPPED)) 1624 return (inp); 1625 1626 tp = intotcpcb(inp); 1627 if (tp->t_state != TCPS_SYN_SENT) 1628 return (inp); 1629 1630 tp = tcp_drop(tp, errno); 1631 if (tp != NULL) 1632 return (inp); 1633 else 1634 return (NULL); 1635 } 1636 1637 /* 1638 * When `need fragmentation' ICMP is received, update our idea of the MSS 1639 * based on the new value in the route. Also nudge TCP to send something, 1640 * since we know the packet we just sent was dropped. 1641 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1642 */ 1643 struct inpcb * 1644 tcp_mtudisc(struct inpcb *inp, int errno) 1645 { 1646 INIT_VNET_INET(inp->inp_vnet); 1647 struct tcpcb *tp; 1648 struct socket *so; 1649 1650 INP_WLOCK_ASSERT(inp); 1651 if ((inp->inp_flags & INP_TIMEWAIT) || 1652 (inp->inp_flags & INP_DROPPED)) 1653 return (inp); 1654 1655 tp = intotcpcb(inp); 1656 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1657 1658 tcp_mss_update(tp, -1, NULL, NULL); 1659 1660 so = inp->inp_socket; 1661 SOCKBUF_LOCK(&so->so_snd); 1662 /* If the mss is larger than the socket buffer, decrease the mss. */ 1663 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1664 tp->t_maxseg = so->so_snd.sb_hiwat; 1665 SOCKBUF_UNLOCK(&so->so_snd); 1666 1667 TCPSTAT_INC(tcps_mturesent); 1668 tp->t_rtttime = 0; 1669 tp->snd_nxt = tp->snd_una; 1670 tcp_free_sackholes(tp); 1671 tp->snd_recover = tp->snd_max; 1672 if (tp->t_flags & TF_SACK_PERMIT) 1673 EXIT_FASTRECOVERY(tp); 1674 tcp_output_send(tp); 1675 return (inp); 1676 } 1677 1678 /* 1679 * Look-up the routing entry to the peer of this inpcb. If no route 1680 * is found and it cannot be allocated, then return 0. This routine 1681 * is called by TCP routines that access the rmx structure and by 1682 * tcp_mss_update to get the peer/interface MTU. 1683 */ 1684 u_long 1685 tcp_maxmtu(struct in_conninfo *inc, int *flags) 1686 { 1687 struct route sro; 1688 struct sockaddr_in *dst; 1689 struct ifnet *ifp; 1690 u_long maxmtu = 0; 1691 1692 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1693 1694 bzero(&sro, sizeof(sro)); 1695 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1696 dst = (struct sockaddr_in *)&sro.ro_dst; 1697 dst->sin_family = AF_INET; 1698 dst->sin_len = sizeof(*dst); 1699 dst->sin_addr = inc->inc_faddr; 1700 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1701 } 1702 if (sro.ro_rt != NULL) { 1703 ifp = sro.ro_rt->rt_ifp; 1704 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1705 maxmtu = ifp->if_mtu; 1706 else 1707 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1708 1709 /* Report additional interface capabilities. */ 1710 if (flags != NULL) { 1711 if (ifp->if_capenable & IFCAP_TSO4 && 1712 ifp->if_hwassist & CSUM_TSO) 1713 *flags |= CSUM_TSO; 1714 } 1715 RTFREE(sro.ro_rt); 1716 } 1717 return (maxmtu); 1718 } 1719 1720 #ifdef INET6 1721 u_long 1722 tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1723 { 1724 struct route_in6 sro6; 1725 struct ifnet *ifp; 1726 u_long maxmtu = 0; 1727 1728 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1729 1730 bzero(&sro6, sizeof(sro6)); 1731 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1732 sro6.ro_dst.sin6_family = AF_INET6; 1733 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1734 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1735 rtalloc_ign((struct route *)&sro6, 0); 1736 } 1737 if (sro6.ro_rt != NULL) { 1738 ifp = sro6.ro_rt->rt_ifp; 1739 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1740 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1741 else 1742 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1743 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1744 1745 /* Report additional interface capabilities. */ 1746 if (flags != NULL) { 1747 if (ifp->if_capenable & IFCAP_TSO6 && 1748 ifp->if_hwassist & CSUM_TSO) 1749 *flags |= CSUM_TSO; 1750 } 1751 RTFREE(sro6.ro_rt); 1752 } 1753 1754 return (maxmtu); 1755 } 1756 #endif /* INET6 */ 1757 1758 #ifdef IPSEC 1759 /* compute ESP/AH header size for TCP, including outer IP header. */ 1760 size_t 1761 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1762 { 1763 struct inpcb *inp; 1764 struct mbuf *m; 1765 size_t hdrsiz; 1766 struct ip *ip; 1767 #ifdef INET6 1768 struct ip6_hdr *ip6; 1769 #endif 1770 struct tcphdr *th; 1771 1772 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1773 return (0); 1774 MGETHDR(m, M_DONTWAIT, MT_DATA); 1775 if (!m) 1776 return (0); 1777 1778 #ifdef INET6 1779 if ((inp->inp_vflag & INP_IPV6) != 0) { 1780 ip6 = mtod(m, struct ip6_hdr *); 1781 th = (struct tcphdr *)(ip6 + 1); 1782 m->m_pkthdr.len = m->m_len = 1783 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1784 tcpip_fillheaders(inp, ip6, th); 1785 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1786 } else 1787 #endif /* INET6 */ 1788 { 1789 ip = mtod(m, struct ip *); 1790 th = (struct tcphdr *)(ip + 1); 1791 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1792 tcpip_fillheaders(inp, ip, th); 1793 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1794 } 1795 1796 m_free(m); 1797 return (hdrsiz); 1798 } 1799 #endif /* IPSEC */ 1800 1801 /* 1802 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1803 * 1804 * This code attempts to calculate the bandwidth-delay product as a 1805 * means of determining the optimal window size to maximize bandwidth, 1806 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1807 * routers. This code also does a fairly good job keeping RTTs in check 1808 * across slow links like modems. We implement an algorithm which is very 1809 * similar (but not meant to be) TCP/Vegas. The code operates on the 1810 * transmitter side of a TCP connection and so only effects the transmit 1811 * side of the connection. 1812 * 1813 * BACKGROUND: TCP makes no provision for the management of buffer space 1814 * at the end points or at the intermediate routers and switches. A TCP 1815 * stream, whether using NewReno or not, will eventually buffer as 1816 * many packets as it is able and the only reason this typically works is 1817 * due to the fairly small default buffers made available for a connection 1818 * (typicaly 16K or 32K). As machines use larger windows and/or window 1819 * scaling it is now fairly easy for even a single TCP connection to blow-out 1820 * all available buffer space not only on the local interface, but on 1821 * intermediate routers and switches as well. NewReno makes a misguided 1822 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1823 * then backing off, then steadily increasing the window again until another 1824 * failure occurs, ad-infinitum. This results in terrible oscillation that 1825 * is only made worse as network loads increase and the idea of intentionally 1826 * blowing out network buffers is, frankly, a terrible way to manage network 1827 * resources. 1828 * 1829 * It is far better to limit the transmit window prior to the failure 1830 * condition being achieved. There are two general ways to do this: First 1831 * you can 'scan' through different transmit window sizes and locate the 1832 * point where the RTT stops increasing, indicating that you have filled the 1833 * pipe, then scan backwards until you note that RTT stops decreasing, then 1834 * repeat ad-infinitum. This method works in principle but has severe 1835 * implementation issues due to RTT variances, timer granularity, and 1836 * instability in the algorithm which can lead to many false positives and 1837 * create oscillations as well as interact badly with other TCP streams 1838 * implementing the same algorithm. 1839 * 1840 * The second method is to limit the window to the bandwidth delay product 1841 * of the link. This is the method we implement. RTT variances and our 1842 * own manipulation of the congestion window, bwnd, can potentially 1843 * destabilize the algorithm. For this reason we have to stabilize the 1844 * elements used to calculate the window. We do this by using the minimum 1845 * observed RTT, the long term average of the observed bandwidth, and 1846 * by adding two segments worth of slop. It isn't perfect but it is able 1847 * to react to changing conditions and gives us a very stable basis on 1848 * which to extend the algorithm. 1849 */ 1850 void 1851 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1852 { 1853 INIT_VNET_INET(tp->t_vnet); 1854 u_long bw; 1855 u_long bwnd; 1856 int save_ticks; 1857 1858 INP_WLOCK_ASSERT(tp->t_inpcb); 1859 1860 /* 1861 * If inflight_enable is disabled in the middle of a tcp connection, 1862 * make sure snd_bwnd is effectively disabled. 1863 */ 1864 if (V_tcp_inflight_enable == 0 || 1865 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1866 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1867 tp->snd_bandwidth = 0; 1868 return; 1869 } 1870 1871 /* 1872 * Figure out the bandwidth. Due to the tick granularity this 1873 * is a very rough number and it MUST be averaged over a fairly 1874 * long period of time. XXX we need to take into account a link 1875 * that is not using all available bandwidth, but for now our 1876 * slop will ramp us up if this case occurs and the bandwidth later 1877 * increases. 1878 * 1879 * Note: if ticks rollover 'bw' may wind up negative. We must 1880 * effectively reset t_bw_rtttime for this case. 1881 */ 1882 save_ticks = ticks; 1883 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1884 return; 1885 1886 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1887 (save_ticks - tp->t_bw_rtttime); 1888 tp->t_bw_rtttime = save_ticks; 1889 tp->t_bw_rtseq = ack_seq; 1890 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1891 return; 1892 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1893 1894 tp->snd_bandwidth = bw; 1895 1896 /* 1897 * Calculate the semi-static bandwidth delay product, plus two maximal 1898 * segments. The additional slop puts us squarely in the sweet 1899 * spot and also handles the bandwidth run-up case and stabilization. 1900 * Without the slop we could be locking ourselves into a lower 1901 * bandwidth. 1902 * 1903 * Situations Handled: 1904 * (1) Prevents over-queueing of packets on LANs, especially on 1905 * high speed LANs, allowing larger TCP buffers to be 1906 * specified, and also does a good job preventing 1907 * over-queueing of packets over choke points like modems 1908 * (at least for the transmit side). 1909 * 1910 * (2) Is able to handle changing network loads (bandwidth 1911 * drops so bwnd drops, bandwidth increases so bwnd 1912 * increases). 1913 * 1914 * (3) Theoretically should stabilize in the face of multiple 1915 * connections implementing the same algorithm (this may need 1916 * a little work). 1917 * 1918 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1919 * be adjusted with a sysctl but typically only needs to be 1920 * on very slow connections. A value no smaller then 5 1921 * should be used, but only reduce this default if you have 1922 * no other choice. 1923 */ 1924 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1925 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1926 #undef USERTT 1927 1928 if (tcp_inflight_debug > 0) { 1929 static int ltime; 1930 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1931 ltime = ticks; 1932 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1933 tp, 1934 bw, 1935 tp->t_rttbest, 1936 tp->t_srtt, 1937 bwnd 1938 ); 1939 } 1940 } 1941 if ((long)bwnd < V_tcp_inflight_min) 1942 bwnd = V_tcp_inflight_min; 1943 if (bwnd > V_tcp_inflight_max) 1944 bwnd = V_tcp_inflight_max; 1945 if ((long)bwnd < tp->t_maxseg * 2) 1946 bwnd = tp->t_maxseg * 2; 1947 tp->snd_bwnd = bwnd; 1948 } 1949 1950 #ifdef TCP_SIGNATURE 1951 /* 1952 * Callback function invoked by m_apply() to digest TCP segment data 1953 * contained within an mbuf chain. 1954 */ 1955 static int 1956 tcp_signature_apply(void *fstate, void *data, u_int len) 1957 { 1958 1959 MD5Update(fstate, (u_char *)data, len); 1960 return (0); 1961 } 1962 1963 /* 1964 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1965 * 1966 * Parameters: 1967 * m pointer to head of mbuf chain 1968 * _unused 1969 * len length of TCP segment data, excluding options 1970 * optlen length of TCP segment options 1971 * buf pointer to storage for computed MD5 digest 1972 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1973 * 1974 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1975 * When called from tcp_input(), we can be sure that th_sum has been 1976 * zeroed out and verified already. 1977 * 1978 * Return 0 if successful, otherwise return -1. 1979 * 1980 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1981 * search with the destination IP address, and a 'magic SPI' to be 1982 * determined by the application. This is hardcoded elsewhere to 1179 1983 * right now. Another branch of this code exists which uses the SPD to 1984 * specify per-application flows but it is unstable. 1985 */ 1986 int 1987 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1988 u_char *buf, u_int direction) 1989 { 1990 INIT_VNET_IPSEC(curvnet); 1991 union sockaddr_union dst; 1992 struct ippseudo ippseudo; 1993 MD5_CTX ctx; 1994 int doff; 1995 struct ip *ip; 1996 struct ipovly *ipovly; 1997 struct secasvar *sav; 1998 struct tcphdr *th; 1999 #ifdef INET6 2000 struct ip6_hdr *ip6; 2001 struct in6_addr in6; 2002 char ip6buf[INET6_ADDRSTRLEN]; 2003 uint32_t plen; 2004 uint16_t nhdr; 2005 #endif 2006 u_short savecsum; 2007 2008 KASSERT(m != NULL, ("NULL mbuf chain")); 2009 KASSERT(buf != NULL, ("NULL signature pointer")); 2010 2011 /* Extract the destination from the IP header in the mbuf. */ 2012 bzero(&dst, sizeof(union sockaddr_union)); 2013 ip = mtod(m, struct ip *); 2014 #ifdef INET6 2015 ip6 = NULL; /* Make the compiler happy. */ 2016 #endif 2017 switch (ip->ip_v) { 2018 case IPVERSION: 2019 dst.sa.sa_len = sizeof(struct sockaddr_in); 2020 dst.sa.sa_family = AF_INET; 2021 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2022 ip->ip_src : ip->ip_dst; 2023 break; 2024 #ifdef INET6 2025 case (IPV6_VERSION >> 4): 2026 ip6 = mtod(m, struct ip6_hdr *); 2027 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2028 dst.sa.sa_family = AF_INET6; 2029 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2030 ip6->ip6_src : ip6->ip6_dst; 2031 break; 2032 #endif 2033 default: 2034 return (EINVAL); 2035 /* NOTREACHED */ 2036 break; 2037 } 2038 2039 /* Look up an SADB entry which matches the address of the peer. */ 2040 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2041 if (sav == NULL) { 2042 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2043 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2044 #ifdef INET6 2045 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2046 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2047 #endif 2048 "(unsupported)")); 2049 return (EINVAL); 2050 } 2051 2052 MD5Init(&ctx); 2053 /* 2054 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2055 * 2056 * XXX The ippseudo header MUST be digested in network byte order, 2057 * or else we'll fail the regression test. Assume all fields we've 2058 * been doing arithmetic on have been in host byte order. 2059 * XXX One cannot depend on ipovly->ih_len here. When called from 2060 * tcp_output(), the underlying ip_len member has not yet been set. 2061 */ 2062 switch (ip->ip_v) { 2063 case IPVERSION: 2064 ipovly = (struct ipovly *)ip; 2065 ippseudo.ippseudo_src = ipovly->ih_src; 2066 ippseudo.ippseudo_dst = ipovly->ih_dst; 2067 ippseudo.ippseudo_pad = 0; 2068 ippseudo.ippseudo_p = IPPROTO_TCP; 2069 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2070 optlen); 2071 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2072 2073 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2074 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2075 break; 2076 #ifdef INET6 2077 /* 2078 * RFC 2385, 2.0 Proposal 2079 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2080 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2081 * extended next header value (to form 32 bits), and 32-bit segment 2082 * length. 2083 * Note: Upper-Layer Packet Length comes before Next Header. 2084 */ 2085 case (IPV6_VERSION >> 4): 2086 in6 = ip6->ip6_src; 2087 in6_clearscope(&in6); 2088 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2089 in6 = ip6->ip6_dst; 2090 in6_clearscope(&in6); 2091 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2092 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2093 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2094 nhdr = 0; 2095 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2096 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2097 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2098 nhdr = IPPROTO_TCP; 2099 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2100 2101 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2102 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2103 break; 2104 #endif 2105 default: 2106 return (EINVAL); 2107 /* NOTREACHED */ 2108 break; 2109 } 2110 2111 2112 /* 2113 * Step 2: Update MD5 hash with TCP header, excluding options. 2114 * The TCP checksum must be set to zero. 2115 */ 2116 savecsum = th->th_sum; 2117 th->th_sum = 0; 2118 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2119 th->th_sum = savecsum; 2120 2121 /* 2122 * Step 3: Update MD5 hash with TCP segment data. 2123 * Use m_apply() to avoid an early m_pullup(). 2124 */ 2125 if (len > 0) 2126 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2127 2128 /* 2129 * Step 4: Update MD5 hash with shared secret. 2130 */ 2131 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2132 MD5Final(buf, &ctx); 2133 2134 key_sa_recordxfer(sav, m); 2135 KEY_FREESAV(&sav); 2136 return (0); 2137 } 2138 #endif /* TCP_SIGNATURE */ 2139 2140 static int 2141 sysctl_drop(SYSCTL_HANDLER_ARGS) 2142 { 2143 INIT_VNET_INET(curvnet); 2144 #ifdef INET6 2145 INIT_VNET_INET6(curvnet); 2146 #endif 2147 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2148 struct sockaddr_storage addrs[2]; 2149 struct inpcb *inp; 2150 struct tcpcb *tp; 2151 struct tcptw *tw; 2152 struct sockaddr_in *fin, *lin; 2153 #ifdef INET6 2154 struct sockaddr_in6 *fin6, *lin6; 2155 #endif 2156 int error; 2157 2158 inp = NULL; 2159 fin = lin = NULL; 2160 #ifdef INET6 2161 fin6 = lin6 = NULL; 2162 #endif 2163 error = 0; 2164 2165 if (req->oldptr != NULL || req->oldlen != 0) 2166 return (EINVAL); 2167 if (req->newptr == NULL) 2168 return (EPERM); 2169 if (req->newlen < sizeof(addrs)) 2170 return (ENOMEM); 2171 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2172 if (error) 2173 return (error); 2174 2175 switch (addrs[0].ss_family) { 2176 #ifdef INET6 2177 case AF_INET6: 2178 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2179 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2180 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2181 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2182 return (EINVAL); 2183 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2184 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2185 return (EINVAL); 2186 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2187 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2188 fin = (struct sockaddr_in *)&addrs[0]; 2189 lin = (struct sockaddr_in *)&addrs[1]; 2190 break; 2191 } 2192 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2193 if (error) 2194 return (error); 2195 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2196 if (error) 2197 return (error); 2198 break; 2199 #endif 2200 case AF_INET: 2201 fin = (struct sockaddr_in *)&addrs[0]; 2202 lin = (struct sockaddr_in *)&addrs[1]; 2203 if (fin->sin_len != sizeof(struct sockaddr_in) || 2204 lin->sin_len != sizeof(struct sockaddr_in)) 2205 return (EINVAL); 2206 break; 2207 default: 2208 return (EINVAL); 2209 } 2210 INP_INFO_WLOCK(&V_tcbinfo); 2211 switch (addrs[0].ss_family) { 2212 #ifdef INET6 2213 case AF_INET6: 2214 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2215 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2216 NULL); 2217 break; 2218 #endif 2219 case AF_INET: 2220 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2221 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2222 break; 2223 } 2224 if (inp != NULL) { 2225 INP_WLOCK(inp); 2226 if (inp->inp_flags & INP_TIMEWAIT) { 2227 /* 2228 * XXXRW: There currently exists a state where an 2229 * inpcb is present, but its timewait state has been 2230 * discarded. For now, don't allow dropping of this 2231 * type of inpcb. 2232 */ 2233 tw = intotw(inp); 2234 if (tw != NULL) 2235 tcp_twclose(tw, 0); 2236 else 2237 INP_WUNLOCK(inp); 2238 } else if (!(inp->inp_flags & INP_DROPPED) && 2239 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2240 tp = intotcpcb(inp); 2241 tp = tcp_drop(tp, ECONNABORTED); 2242 if (tp != NULL) 2243 INP_WUNLOCK(inp); 2244 } else 2245 INP_WUNLOCK(inp); 2246 } else 2247 error = ESRCH; 2248 INP_INFO_WUNLOCK(&V_tcbinfo); 2249 return (error); 2250 } 2251 2252 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2253 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2254 0, sysctl_drop, "", "Drop TCP connection"); 2255 2256 /* 2257 * Generate a standardized TCP log line for use throughout the 2258 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2259 * allow use in the interrupt context. 2260 * 2261 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2262 * NB: The function may return NULL if memory allocation failed. 2263 * 2264 * Due to header inclusion and ordering limitations the struct ip 2265 * and ip6_hdr pointers have to be passed as void pointers. 2266 */ 2267 char * 2268 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2269 const void *ip6hdr) 2270 { 2271 char *s, *sp; 2272 size_t size; 2273 struct ip *ip; 2274 #ifdef INET6 2275 const struct ip6_hdr *ip6; 2276 2277 ip6 = (const struct ip6_hdr *)ip6hdr; 2278 #endif /* INET6 */ 2279 ip = (struct ip *)ip4hdr; 2280 2281 /* 2282 * The log line looks like this: 2283 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2284 */ 2285 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2286 sizeof(PRINT_TH_FLAGS) + 1 + 2287 #ifdef INET6 2288 2 * INET6_ADDRSTRLEN; 2289 #else 2290 2 * INET_ADDRSTRLEN; 2291 #endif /* INET6 */ 2292 2293 /* Is logging enabled? */ 2294 if (tcp_log_debug == 0 && tcp_log_in_vain == 0) 2295 return (NULL); 2296 2297 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2298 if (s == NULL) 2299 return (NULL); 2300 2301 strcat(s, "TCP: ["); 2302 sp = s + strlen(s); 2303 2304 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2305 inet_ntoa_r(inc->inc_faddr, sp); 2306 sp = s + strlen(s); 2307 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2308 sp = s + strlen(s); 2309 inet_ntoa_r(inc->inc_laddr, sp); 2310 sp = s + strlen(s); 2311 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2312 #ifdef INET6 2313 } else if (inc) { 2314 ip6_sprintf(sp, &inc->inc6_faddr); 2315 sp = s + strlen(s); 2316 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2317 sp = s + strlen(s); 2318 ip6_sprintf(sp, &inc->inc6_laddr); 2319 sp = s + strlen(s); 2320 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2321 } else if (ip6 && th) { 2322 ip6_sprintf(sp, &ip6->ip6_src); 2323 sp = s + strlen(s); 2324 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2325 sp = s + strlen(s); 2326 ip6_sprintf(sp, &ip6->ip6_dst); 2327 sp = s + strlen(s); 2328 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2329 #endif /* INET6 */ 2330 } else if (ip && th) { 2331 inet_ntoa_r(ip->ip_src, sp); 2332 sp = s + strlen(s); 2333 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2334 sp = s + strlen(s); 2335 inet_ntoa_r(ip->ip_dst, sp); 2336 sp = s + strlen(s); 2337 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2338 } else { 2339 free(s, M_TCPLOG); 2340 return (NULL); 2341 } 2342 sp = s + strlen(s); 2343 if (th) 2344 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2345 if (*(s + size - 1) != '\0') 2346 panic("%s: string too long", __func__); 2347 return (s); 2348 } 2349