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_mac.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/kernel.h> 46 #include <sys/sysctl.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(curvnet); 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(curvnet); 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 void 431 tcp_fini(void *xtp) 432 { 433 434 callout_stop(&isn_callout); 435 } 436 437 /* 438 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 439 * tcp_template used to store this data in mbufs, but we now recopy it out 440 * of the tcpcb each time to conserve mbufs. 441 */ 442 void 443 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 444 { 445 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 446 447 INP_WLOCK_ASSERT(inp); 448 449 #ifdef INET6 450 if ((inp->inp_vflag & INP_IPV6) != 0) { 451 struct ip6_hdr *ip6; 452 453 ip6 = (struct ip6_hdr *)ip_ptr; 454 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 455 (inp->inp_flow & IPV6_FLOWINFO_MASK); 456 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 457 (IPV6_VERSION & IPV6_VERSION_MASK); 458 ip6->ip6_nxt = IPPROTO_TCP; 459 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 460 ip6->ip6_src = inp->in6p_laddr; 461 ip6->ip6_dst = inp->in6p_faddr; 462 } else 463 #endif 464 { 465 struct ip *ip; 466 467 ip = (struct ip *)ip_ptr; 468 ip->ip_v = IPVERSION; 469 ip->ip_hl = 5; 470 ip->ip_tos = inp->inp_ip_tos; 471 ip->ip_len = 0; 472 ip->ip_id = 0; 473 ip->ip_off = 0; 474 ip->ip_ttl = inp->inp_ip_ttl; 475 ip->ip_sum = 0; 476 ip->ip_p = IPPROTO_TCP; 477 ip->ip_src = inp->inp_laddr; 478 ip->ip_dst = inp->inp_faddr; 479 } 480 th->th_sport = inp->inp_lport; 481 th->th_dport = inp->inp_fport; 482 th->th_seq = 0; 483 th->th_ack = 0; 484 th->th_x2 = 0; 485 th->th_off = 5; 486 th->th_flags = 0; 487 th->th_win = 0; 488 th->th_urp = 0; 489 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 490 } 491 492 /* 493 * Create template to be used to send tcp packets on a connection. 494 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 495 * use for this function is in keepalives, which use tcp_respond. 496 */ 497 struct tcptemp * 498 tcpip_maketemplate(struct inpcb *inp) 499 { 500 struct tcptemp *t; 501 502 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 503 if (t == NULL) 504 return (NULL); 505 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 506 return (t); 507 } 508 509 /* 510 * Send a single message to the TCP at address specified by 511 * the given TCP/IP header. If m == NULL, then we make a copy 512 * of the tcpiphdr at ti and send directly to the addressed host. 513 * This is used to force keep alive messages out using the TCP 514 * template for a connection. If flags are given then we send 515 * a message back to the TCP which originated the * segment ti, 516 * and discard the mbuf containing it and any other attached mbufs. 517 * 518 * In any case the ack and sequence number of the transmitted 519 * segment are as specified by the parameters. 520 * 521 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 522 */ 523 void 524 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 525 tcp_seq ack, tcp_seq seq, int flags) 526 { 527 INIT_VNET_INET(curvnet); 528 int tlen; 529 int win = 0; 530 struct ip *ip; 531 struct tcphdr *nth; 532 #ifdef INET6 533 struct ip6_hdr *ip6; 534 int isipv6; 535 #endif /* INET6 */ 536 int ipflags = 0; 537 struct inpcb *inp; 538 539 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 540 541 #ifdef INET6 542 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 543 ip6 = ipgen; 544 #endif /* INET6 */ 545 ip = ipgen; 546 547 if (tp != NULL) { 548 inp = tp->t_inpcb; 549 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 550 INP_WLOCK_ASSERT(inp); 551 } else 552 inp = NULL; 553 554 if (tp != NULL) { 555 if (!(flags & TH_RST)) { 556 win = sbspace(&inp->inp_socket->so_rcv); 557 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 558 win = (long)TCP_MAXWIN << tp->rcv_scale; 559 } 560 } 561 if (m == NULL) { 562 m = m_gethdr(M_DONTWAIT, MT_DATA); 563 if (m == NULL) 564 return; 565 tlen = 0; 566 m->m_data += max_linkhdr; 567 #ifdef INET6 568 if (isipv6) { 569 bcopy((caddr_t)ip6, mtod(m, caddr_t), 570 sizeof(struct ip6_hdr)); 571 ip6 = mtod(m, struct ip6_hdr *); 572 nth = (struct tcphdr *)(ip6 + 1); 573 } else 574 #endif /* INET6 */ 575 { 576 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 577 ip = mtod(m, struct ip *); 578 nth = (struct tcphdr *)(ip + 1); 579 } 580 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 581 flags = TH_ACK; 582 } else { 583 /* 584 * reuse the mbuf. 585 * XXX MRT We inherrit the FIB, which is lucky. 586 */ 587 m_freem(m->m_next); 588 m->m_next = NULL; 589 m->m_data = (caddr_t)ipgen; 590 /* m_len is set later */ 591 tlen = 0; 592 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 593 #ifdef INET6 594 if (isipv6) { 595 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 596 nth = (struct tcphdr *)(ip6 + 1); 597 } else 598 #endif /* INET6 */ 599 { 600 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 601 nth = (struct tcphdr *)(ip + 1); 602 } 603 if (th != nth) { 604 /* 605 * this is usually a case when an extension header 606 * exists between the IPv6 header and the 607 * TCP header. 608 */ 609 nth->th_sport = th->th_sport; 610 nth->th_dport = th->th_dport; 611 } 612 xchg(nth->th_dport, nth->th_sport, uint16_t); 613 #undef xchg 614 } 615 #ifdef INET6 616 if (isipv6) { 617 ip6->ip6_flow = 0; 618 ip6->ip6_vfc = IPV6_VERSION; 619 ip6->ip6_nxt = IPPROTO_TCP; 620 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 621 tlen)); 622 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 623 } else 624 #endif 625 { 626 tlen += sizeof (struct tcpiphdr); 627 ip->ip_len = tlen; 628 ip->ip_ttl = V_ip_defttl; 629 if (V_path_mtu_discovery) 630 ip->ip_off |= IP_DF; 631 } 632 m->m_len = tlen; 633 m->m_pkthdr.len = tlen; 634 m->m_pkthdr.rcvif = NULL; 635 #ifdef MAC 636 if (inp != NULL) { 637 /* 638 * Packet is associated with a socket, so allow the 639 * label of the response to reflect the socket label. 640 */ 641 INP_WLOCK_ASSERT(inp); 642 mac_inpcb_create_mbuf(inp, m); 643 } else { 644 /* 645 * Packet is not associated with a socket, so possibly 646 * update the label in place. 647 */ 648 mac_netinet_tcp_reply(m); 649 } 650 #endif 651 nth->th_seq = htonl(seq); 652 nth->th_ack = htonl(ack); 653 nth->th_x2 = 0; 654 nth->th_off = sizeof (struct tcphdr) >> 2; 655 nth->th_flags = flags; 656 if (tp != NULL) 657 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 658 else 659 nth->th_win = htons((u_short)win); 660 nth->th_urp = 0; 661 #ifdef INET6 662 if (isipv6) { 663 nth->th_sum = 0; 664 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 665 sizeof(struct ip6_hdr), 666 tlen - sizeof(struct ip6_hdr)); 667 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 668 NULL, NULL); 669 } else 670 #endif /* INET6 */ 671 { 672 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 673 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 674 m->m_pkthdr.csum_flags = CSUM_TCP; 675 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 676 } 677 #ifdef TCPDEBUG 678 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 679 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 680 #endif 681 #ifdef INET6 682 if (isipv6) 683 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 684 else 685 #endif /* INET6 */ 686 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 687 } 688 689 /* 690 * Create a new TCP control block, making an 691 * empty reassembly queue and hooking it to the argument 692 * protocol control block. The `inp' parameter must have 693 * come from the zone allocator set up in tcp_init(). 694 */ 695 struct tcpcb * 696 tcp_newtcpcb(struct inpcb *inp) 697 { 698 INIT_VNET_INET(inp->inp_vnet); 699 struct tcpcb_mem *tm; 700 struct tcpcb *tp; 701 #ifdef INET6 702 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 703 #endif /* INET6 */ 704 705 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 706 if (tm == NULL) 707 return (NULL); 708 tp = &tm->tcb; 709 #ifdef VIMAGE 710 tp->t_vnet = inp->inp_vnet; 711 #endif 712 tp->t_timers = &tm->tt; 713 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 714 tp->t_maxseg = tp->t_maxopd = 715 #ifdef INET6 716 isipv6 ? V_tcp_v6mssdflt : 717 #endif /* INET6 */ 718 V_tcp_mssdflt; 719 720 /* Set up our timeouts. */ 721 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 722 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 723 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 724 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 725 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 726 727 if (V_tcp_do_rfc1323) 728 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 729 if (V_tcp_do_sack) 730 tp->t_flags |= TF_SACK_PERMIT; 731 TAILQ_INIT(&tp->snd_holes); 732 tp->t_inpcb = inp; /* XXX */ 733 /* 734 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 735 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 736 * reasonable initial retransmit time. 737 */ 738 tp->t_srtt = TCPTV_SRTTBASE; 739 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 740 tp->t_rttmin = tcp_rexmit_min; 741 tp->t_rxtcur = TCPTV_RTOBASE; 742 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 743 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 744 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 745 tp->t_rcvtime = ticks; 746 tp->t_bw_rtttime = ticks; 747 /* 748 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 749 * because the socket may be bound to an IPv6 wildcard address, 750 * which may match an IPv4-mapped IPv6 address. 751 */ 752 inp->inp_ip_ttl = V_ip_defttl; 753 inp->inp_ppcb = tp; 754 return (tp); /* XXX */ 755 } 756 757 /* 758 * Drop a TCP connection, reporting 759 * the specified error. If connection is synchronized, 760 * then send a RST to peer. 761 */ 762 struct tcpcb * 763 tcp_drop(struct tcpcb *tp, int errno) 764 { 765 INIT_VNET_INET(tp->t_inpcb->inp_vnet); 766 struct socket *so = tp->t_inpcb->inp_socket; 767 768 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 769 INP_WLOCK_ASSERT(tp->t_inpcb); 770 771 if (TCPS_HAVERCVDSYN(tp->t_state)) { 772 tp->t_state = TCPS_CLOSED; 773 (void) tcp_output_reset(tp); 774 TCPSTAT_INC(tcps_drops); 775 } else 776 TCPSTAT_INC(tcps_conndrops); 777 if (errno == ETIMEDOUT && tp->t_softerror) 778 errno = tp->t_softerror; 779 so->so_error = errno; 780 return (tcp_close(tp)); 781 } 782 783 void 784 tcp_discardcb(struct tcpcb *tp) 785 { 786 INIT_VNET_INET(tp->t_vnet); 787 struct tseg_qent *q; 788 struct inpcb *inp = tp->t_inpcb; 789 struct socket *so = inp->inp_socket; 790 #ifdef INET6 791 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 792 #endif /* INET6 */ 793 794 INP_WLOCK_ASSERT(inp); 795 796 /* 797 * Make sure that all of our timers are stopped before we 798 * delete the PCB. 799 */ 800 callout_stop(&tp->t_timers->tt_rexmt); 801 callout_stop(&tp->t_timers->tt_persist); 802 callout_stop(&tp->t_timers->tt_keep); 803 callout_stop(&tp->t_timers->tt_2msl); 804 callout_stop(&tp->t_timers->tt_delack); 805 806 /* 807 * If we got enough samples through the srtt filter, 808 * save the rtt and rttvar in the routing entry. 809 * 'Enough' is arbitrarily defined as 4 rtt samples. 810 * 4 samples is enough for the srtt filter to converge 811 * to within enough % of the correct value; fewer samples 812 * and we could save a bogus rtt. The danger is not high 813 * as tcp quickly recovers from everything. 814 * XXX: Works very well but needs some more statistics! 815 */ 816 if (tp->t_rttupdated >= 4) { 817 struct hc_metrics_lite metrics; 818 u_long ssthresh; 819 820 bzero(&metrics, sizeof(metrics)); 821 /* 822 * Update the ssthresh always when the conditions below 823 * are satisfied. This gives us better new start value 824 * for the congestion avoidance for new connections. 825 * ssthresh is only set if packet loss occured on a session. 826 * 827 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 828 * being torn down. Ideally this code would not use 'so'. 829 */ 830 ssthresh = tp->snd_ssthresh; 831 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 832 /* 833 * convert the limit from user data bytes to 834 * packets then to packet data bytes. 835 */ 836 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 837 if (ssthresh < 2) 838 ssthresh = 2; 839 ssthresh *= (u_long)(tp->t_maxseg + 840 #ifdef INET6 841 (isipv6 ? sizeof (struct ip6_hdr) + 842 sizeof (struct tcphdr) : 843 #endif 844 sizeof (struct tcpiphdr) 845 #ifdef INET6 846 ) 847 #endif 848 ); 849 } else 850 ssthresh = 0; 851 metrics.rmx_ssthresh = ssthresh; 852 853 metrics.rmx_rtt = tp->t_srtt; 854 metrics.rmx_rttvar = tp->t_rttvar; 855 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 856 metrics.rmx_bandwidth = tp->snd_bandwidth; 857 metrics.rmx_cwnd = tp->snd_cwnd; 858 metrics.rmx_sendpipe = 0; 859 metrics.rmx_recvpipe = 0; 860 861 tcp_hc_update(&inp->inp_inc, &metrics); 862 } 863 864 /* free the reassembly queue, if any */ 865 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 866 LIST_REMOVE(q, tqe_q); 867 m_freem(q->tqe_m); 868 uma_zfree(V_tcp_reass_zone, q); 869 tp->t_segqlen--; 870 V_tcp_reass_qsize--; 871 } 872 /* Disconnect offload device, if any. */ 873 tcp_offload_detach(tp); 874 875 tcp_free_sackholes(tp); 876 inp->inp_ppcb = NULL; 877 tp->t_inpcb = NULL; 878 uma_zfree(V_tcpcb_zone, tp); 879 } 880 881 /* 882 * Attempt to close a TCP control block, marking it as dropped, and freeing 883 * the socket if we hold the only reference. 884 */ 885 struct tcpcb * 886 tcp_close(struct tcpcb *tp) 887 { 888 INIT_VNET_INET(tp->t_inpcb->inp_vnet); 889 struct inpcb *inp = tp->t_inpcb; 890 struct socket *so; 891 892 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 893 INP_WLOCK_ASSERT(inp); 894 895 /* Notify any offload devices of listener close */ 896 if (tp->t_state == TCPS_LISTEN) 897 tcp_offload_listen_close(tp); 898 in_pcbdrop(inp); 899 TCPSTAT_INC(tcps_closed); 900 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 901 so = inp->inp_socket; 902 soisdisconnected(so); 903 if (inp->inp_flags & INP_SOCKREF) { 904 KASSERT(so->so_state & SS_PROTOREF, 905 ("tcp_close: !SS_PROTOREF")); 906 inp->inp_flags &= ~INP_SOCKREF; 907 INP_WUNLOCK(inp); 908 ACCEPT_LOCK(); 909 SOCK_LOCK(so); 910 so->so_state &= ~SS_PROTOREF; 911 sofree(so); 912 return (NULL); 913 } 914 return (tp); 915 } 916 917 void 918 tcp_drain(void) 919 { 920 VNET_ITERATOR_DECL(vnet_iter); 921 922 if (!do_tcpdrain) 923 return; 924 925 VNET_LIST_RLOCK(); 926 VNET_FOREACH(vnet_iter) { 927 CURVNET_SET(vnet_iter); 928 INIT_VNET_INET(vnet_iter); 929 struct inpcb *inpb; 930 struct tcpcb *tcpb; 931 struct tseg_qent *te; 932 933 /* 934 * Walk the tcpbs, if existing, and flush the reassembly queue, 935 * if there is one... 936 * XXX: The "Net/3" implementation doesn't imply that the TCP 937 * reassembly queue should be flushed, but in a situation 938 * where we're really low on mbufs, this is potentially 939 * usefull. 940 */ 941 INP_INFO_RLOCK(&V_tcbinfo); 942 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 943 if (inpb->inp_flags & INP_TIMEWAIT) 944 continue; 945 INP_WLOCK(inpb); 946 if ((tcpb = intotcpcb(inpb)) != NULL) { 947 while ((te = LIST_FIRST(&tcpb->t_segq)) 948 != NULL) { 949 LIST_REMOVE(te, tqe_q); 950 m_freem(te->tqe_m); 951 uma_zfree(V_tcp_reass_zone, te); 952 tcpb->t_segqlen--; 953 V_tcp_reass_qsize--; 954 } 955 tcp_clean_sackreport(tcpb); 956 } 957 INP_WUNLOCK(inpb); 958 } 959 INP_INFO_RUNLOCK(&V_tcbinfo); 960 CURVNET_RESTORE(); 961 } 962 VNET_LIST_RUNLOCK(); 963 } 964 965 /* 966 * Notify a tcp user of an asynchronous error; 967 * store error as soft error, but wake up user 968 * (for now, won't do anything until can select for soft error). 969 * 970 * Do not wake up user since there currently is no mechanism for 971 * reporting soft errors (yet - a kqueue filter may be added). 972 */ 973 static struct inpcb * 974 tcp_notify(struct inpcb *inp, int error) 975 { 976 struct tcpcb *tp; 977 #ifdef INVARIANTS 978 INIT_VNET_INET(inp->inp_vnet); /* V_tcbinfo WLOCK ASSERT */ 979 #endif 980 981 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 982 INP_WLOCK_ASSERT(inp); 983 984 if ((inp->inp_flags & INP_TIMEWAIT) || 985 (inp->inp_flags & INP_DROPPED)) 986 return (inp); 987 988 tp = intotcpcb(inp); 989 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 990 991 /* 992 * Ignore some errors if we are hooked up. 993 * If connection hasn't completed, has retransmitted several times, 994 * and receives a second error, give up now. This is better 995 * than waiting a long time to establish a connection that 996 * can never complete. 997 */ 998 if (tp->t_state == TCPS_ESTABLISHED && 999 (error == EHOSTUNREACH || error == ENETUNREACH || 1000 error == EHOSTDOWN)) { 1001 return (inp); 1002 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1003 tp->t_softerror) { 1004 tp = tcp_drop(tp, error); 1005 if (tp != NULL) 1006 return (inp); 1007 else 1008 return (NULL); 1009 } else { 1010 tp->t_softerror = error; 1011 return (inp); 1012 } 1013 #if 0 1014 wakeup( &so->so_timeo); 1015 sorwakeup(so); 1016 sowwakeup(so); 1017 #endif 1018 } 1019 1020 static int 1021 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1022 { 1023 INIT_VNET_INET(curvnet); 1024 int error, i, m, n, pcb_count; 1025 struct inpcb *inp, **inp_list; 1026 inp_gen_t gencnt; 1027 struct xinpgen xig; 1028 1029 /* 1030 * The process of preparing the TCB list is too time-consuming and 1031 * resource-intensive to repeat twice on every request. 1032 */ 1033 if (req->oldptr == NULL) { 1034 m = syncache_pcbcount(); 1035 n = V_tcbinfo.ipi_count; 1036 req->oldidx = 2 * (sizeof xig) 1037 + ((m + n) + n/8) * sizeof(struct xtcpcb); 1038 return (0); 1039 } 1040 1041 if (req->newptr != NULL) 1042 return (EPERM); 1043 1044 /* 1045 * OK, now we're committed to doing something. 1046 */ 1047 INP_INFO_RLOCK(&V_tcbinfo); 1048 gencnt = V_tcbinfo.ipi_gencnt; 1049 n = V_tcbinfo.ipi_count; 1050 INP_INFO_RUNLOCK(&V_tcbinfo); 1051 1052 m = syncache_pcbcount(); 1053 1054 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1055 + (n + m) * sizeof(struct xtcpcb)); 1056 if (error != 0) 1057 return (error); 1058 1059 xig.xig_len = sizeof xig; 1060 xig.xig_count = n + m; 1061 xig.xig_gen = gencnt; 1062 xig.xig_sogen = so_gencnt; 1063 error = SYSCTL_OUT(req, &xig, sizeof xig); 1064 if (error) 1065 return (error); 1066 1067 error = syncache_pcblist(req, m, &pcb_count); 1068 if (error) 1069 return (error); 1070 1071 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1072 if (inp_list == NULL) 1073 return (ENOMEM); 1074 1075 INP_INFO_RLOCK(&V_tcbinfo); 1076 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1077 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1078 INP_RLOCK(inp); 1079 if (inp->inp_gencnt <= gencnt) { 1080 /* 1081 * XXX: This use of cr_cansee(), introduced with 1082 * TCP state changes, is not quite right, but for 1083 * now, better than nothing. 1084 */ 1085 if (inp->inp_flags & INP_TIMEWAIT) { 1086 if (intotw(inp) != NULL) 1087 error = cr_cansee(req->td->td_ucred, 1088 intotw(inp)->tw_cred); 1089 else 1090 error = EINVAL; /* Skip this inp. */ 1091 } else 1092 error = cr_canseeinpcb(req->td->td_ucred, inp); 1093 if (error == 0) 1094 inp_list[i++] = inp; 1095 } 1096 INP_RUNLOCK(inp); 1097 } 1098 INP_INFO_RUNLOCK(&V_tcbinfo); 1099 n = i; 1100 1101 error = 0; 1102 for (i = 0; i < n; i++) { 1103 inp = inp_list[i]; 1104 INP_RLOCK(inp); 1105 if (inp->inp_gencnt <= gencnt) { 1106 struct xtcpcb xt; 1107 void *inp_ppcb; 1108 1109 bzero(&xt, sizeof(xt)); 1110 xt.xt_len = sizeof xt; 1111 /* XXX should avoid extra copy */ 1112 bcopy(inp, &xt.xt_inp, sizeof *inp); 1113 inp_ppcb = inp->inp_ppcb; 1114 if (inp_ppcb == NULL) 1115 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1116 else if (inp->inp_flags & INP_TIMEWAIT) { 1117 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1118 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1119 } else 1120 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1121 if (inp->inp_socket != NULL) 1122 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1123 else { 1124 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1125 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1126 } 1127 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1128 INP_RUNLOCK(inp); 1129 error = SYSCTL_OUT(req, &xt, sizeof xt); 1130 } else 1131 INP_RUNLOCK(inp); 1132 1133 } 1134 if (!error) { 1135 /* 1136 * Give the user an updated idea of our state. 1137 * If the generation differs from what we told 1138 * her before, she knows that something happened 1139 * while we were processing this request, and it 1140 * might be necessary to retry. 1141 */ 1142 INP_INFO_RLOCK(&V_tcbinfo); 1143 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1144 xig.xig_sogen = so_gencnt; 1145 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1146 INP_INFO_RUNLOCK(&V_tcbinfo); 1147 error = SYSCTL_OUT(req, &xig, sizeof xig); 1148 } 1149 free(inp_list, M_TEMP); 1150 return (error); 1151 } 1152 1153 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1154 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1155 1156 static int 1157 tcp_getcred(SYSCTL_HANDLER_ARGS) 1158 { 1159 INIT_VNET_INET(curvnet); 1160 struct xucred xuc; 1161 struct sockaddr_in addrs[2]; 1162 struct inpcb *inp; 1163 int error; 1164 1165 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1166 if (error) 1167 return (error); 1168 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1169 if (error) 1170 return (error); 1171 INP_INFO_RLOCK(&V_tcbinfo); 1172 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1173 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1174 if (inp != NULL) { 1175 INP_RLOCK(inp); 1176 INP_INFO_RUNLOCK(&V_tcbinfo); 1177 if (inp->inp_socket == NULL) 1178 error = ENOENT; 1179 if (error == 0) 1180 error = cr_canseeinpcb(req->td->td_ucred, inp); 1181 if (error == 0) 1182 cru2x(inp->inp_cred, &xuc); 1183 INP_RUNLOCK(inp); 1184 } else { 1185 INP_INFO_RUNLOCK(&V_tcbinfo); 1186 error = ENOENT; 1187 } 1188 if (error == 0) 1189 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1190 return (error); 1191 } 1192 1193 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1194 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1195 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1196 1197 #ifdef INET6 1198 static int 1199 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1200 { 1201 INIT_VNET_INET(curvnet); 1202 INIT_VNET_INET6(curvnet); 1203 struct xucred xuc; 1204 struct sockaddr_in6 addrs[2]; 1205 struct inpcb *inp; 1206 int error, mapped = 0; 1207 1208 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1209 if (error) 1210 return (error); 1211 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1212 if (error) 1213 return (error); 1214 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1215 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1216 return (error); 1217 } 1218 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1219 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1220 mapped = 1; 1221 else 1222 return (EINVAL); 1223 } 1224 1225 INP_INFO_RLOCK(&V_tcbinfo); 1226 if (mapped == 1) 1227 inp = in_pcblookup_hash(&V_tcbinfo, 1228 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1229 addrs[1].sin6_port, 1230 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1231 addrs[0].sin6_port, 1232 0, NULL); 1233 else 1234 inp = in6_pcblookup_hash(&V_tcbinfo, 1235 &addrs[1].sin6_addr, addrs[1].sin6_port, 1236 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1237 if (inp != NULL) { 1238 INP_RLOCK(inp); 1239 INP_INFO_RUNLOCK(&V_tcbinfo); 1240 if (inp->inp_socket == NULL) 1241 error = ENOENT; 1242 if (error == 0) 1243 error = cr_canseeinpcb(req->td->td_ucred, inp); 1244 if (error == 0) 1245 cru2x(inp->inp_cred, &xuc); 1246 INP_RUNLOCK(inp); 1247 } else { 1248 INP_INFO_RUNLOCK(&V_tcbinfo); 1249 error = ENOENT; 1250 } 1251 if (error == 0) 1252 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1253 return (error); 1254 } 1255 1256 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1257 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1258 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1259 #endif 1260 1261 1262 void 1263 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1264 { 1265 INIT_VNET_INET(curvnet); 1266 struct ip *ip = vip; 1267 struct tcphdr *th; 1268 struct in_addr faddr; 1269 struct inpcb *inp; 1270 struct tcpcb *tp; 1271 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1272 struct icmp *icp; 1273 struct in_conninfo inc; 1274 tcp_seq icmp_tcp_seq; 1275 int mtu; 1276 1277 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1278 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1279 return; 1280 1281 if (cmd == PRC_MSGSIZE) 1282 notify = tcp_mtudisc; 1283 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1284 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1285 notify = tcp_drop_syn_sent; 1286 /* 1287 * Redirects don't need to be handled up here. 1288 */ 1289 else if (PRC_IS_REDIRECT(cmd)) 1290 return; 1291 /* 1292 * Source quench is depreciated. 1293 */ 1294 else if (cmd == PRC_QUENCH) 1295 return; 1296 /* 1297 * Hostdead is ugly because it goes linearly through all PCBs. 1298 * XXX: We never get this from ICMP, otherwise it makes an 1299 * excellent DoS attack on machines with many connections. 1300 */ 1301 else if (cmd == PRC_HOSTDEAD) 1302 ip = NULL; 1303 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1304 return; 1305 if (ip != NULL) { 1306 icp = (struct icmp *)((caddr_t)ip 1307 - offsetof(struct icmp, icmp_ip)); 1308 th = (struct tcphdr *)((caddr_t)ip 1309 + (ip->ip_hl << 2)); 1310 INP_INFO_WLOCK(&V_tcbinfo); 1311 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1312 ip->ip_src, th->th_sport, 0, NULL); 1313 if (inp != NULL) { 1314 INP_WLOCK(inp); 1315 if (!(inp->inp_flags & INP_TIMEWAIT) && 1316 !(inp->inp_flags & INP_DROPPED) && 1317 !(inp->inp_socket == NULL)) { 1318 icmp_tcp_seq = htonl(th->th_seq); 1319 tp = intotcpcb(inp); 1320 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1321 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1322 if (cmd == PRC_MSGSIZE) { 1323 /* 1324 * MTU discovery: 1325 * If we got a needfrag set the MTU 1326 * in the route to the suggested new 1327 * value (if given) and then notify. 1328 */ 1329 bzero(&inc, sizeof(inc)); 1330 inc.inc_faddr = faddr; 1331 inc.inc_fibnum = 1332 inp->inp_inc.inc_fibnum; 1333 1334 mtu = ntohs(icp->icmp_nextmtu); 1335 /* 1336 * If no alternative MTU was 1337 * proposed, try the next smaller 1338 * one. ip->ip_len has already 1339 * been swapped in icmp_input(). 1340 */ 1341 if (!mtu) 1342 mtu = ip_next_mtu(ip->ip_len, 1343 1); 1344 if (mtu < max(296, V_tcp_minmss 1345 + sizeof(struct tcpiphdr))) 1346 mtu = 0; 1347 if (!mtu) 1348 mtu = V_tcp_mssdflt 1349 + sizeof(struct tcpiphdr); 1350 /* 1351 * Only cache the the MTU if it 1352 * is smaller than the interface 1353 * or route MTU. tcp_mtudisc() 1354 * will do right thing by itself. 1355 */ 1356 if (mtu <= tcp_maxmtu(&inc, NULL)) 1357 tcp_hc_updatemtu(&inc, mtu); 1358 } 1359 1360 inp = (*notify)(inp, inetctlerrmap[cmd]); 1361 } 1362 } 1363 if (inp != NULL) 1364 INP_WUNLOCK(inp); 1365 } else { 1366 bzero(&inc, sizeof(inc)); 1367 inc.inc_fport = th->th_dport; 1368 inc.inc_lport = th->th_sport; 1369 inc.inc_faddr = faddr; 1370 inc.inc_laddr = ip->ip_src; 1371 syncache_unreach(&inc, th); 1372 } 1373 INP_INFO_WUNLOCK(&V_tcbinfo); 1374 } else 1375 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1376 } 1377 1378 #ifdef INET6 1379 void 1380 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1381 { 1382 INIT_VNET_INET(curvnet); 1383 struct tcphdr th; 1384 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1385 struct ip6_hdr *ip6; 1386 struct mbuf *m; 1387 struct ip6ctlparam *ip6cp = NULL; 1388 const struct sockaddr_in6 *sa6_src = NULL; 1389 int off; 1390 struct tcp_portonly { 1391 u_int16_t th_sport; 1392 u_int16_t th_dport; 1393 } *thp; 1394 1395 if (sa->sa_family != AF_INET6 || 1396 sa->sa_len != sizeof(struct sockaddr_in6)) 1397 return; 1398 1399 if (cmd == PRC_MSGSIZE) 1400 notify = tcp_mtudisc; 1401 else if (!PRC_IS_REDIRECT(cmd) && 1402 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1403 return; 1404 /* Source quench is depreciated. */ 1405 else if (cmd == PRC_QUENCH) 1406 return; 1407 1408 /* if the parameter is from icmp6, decode it. */ 1409 if (d != NULL) { 1410 ip6cp = (struct ip6ctlparam *)d; 1411 m = ip6cp->ip6c_m; 1412 ip6 = ip6cp->ip6c_ip6; 1413 off = ip6cp->ip6c_off; 1414 sa6_src = ip6cp->ip6c_src; 1415 } else { 1416 m = NULL; 1417 ip6 = NULL; 1418 off = 0; /* fool gcc */ 1419 sa6_src = &sa6_any; 1420 } 1421 1422 if (ip6 != NULL) { 1423 struct in_conninfo inc; 1424 /* 1425 * XXX: We assume that when IPV6 is non NULL, 1426 * M and OFF are valid. 1427 */ 1428 1429 /* check if we can safely examine src and dst ports */ 1430 if (m->m_pkthdr.len < off + sizeof(*thp)) 1431 return; 1432 1433 bzero(&th, sizeof(th)); 1434 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1435 1436 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1437 (struct sockaddr *)ip6cp->ip6c_src, 1438 th.th_sport, cmd, NULL, notify); 1439 1440 bzero(&inc, sizeof(inc)); 1441 inc.inc_fport = th.th_dport; 1442 inc.inc_lport = th.th_sport; 1443 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1444 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1445 inc.inc_flags |= INC_ISIPV6; 1446 INP_INFO_WLOCK(&V_tcbinfo); 1447 syncache_unreach(&inc, &th); 1448 INP_INFO_WUNLOCK(&V_tcbinfo); 1449 } else 1450 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1451 0, cmd, NULL, notify); 1452 } 1453 #endif /* INET6 */ 1454 1455 1456 /* 1457 * Following is where TCP initial sequence number generation occurs. 1458 * 1459 * There are two places where we must use initial sequence numbers: 1460 * 1. In SYN-ACK packets. 1461 * 2. In SYN packets. 1462 * 1463 * All ISNs for SYN-ACK packets are generated by the syncache. See 1464 * tcp_syncache.c for details. 1465 * 1466 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1467 * depends on this property. In addition, these ISNs should be 1468 * unguessable so as to prevent connection hijacking. To satisfy 1469 * the requirements of this situation, the algorithm outlined in 1470 * RFC 1948 is used, with only small modifications. 1471 * 1472 * Implementation details: 1473 * 1474 * Time is based off the system timer, and is corrected so that it 1475 * increases by one megabyte per second. This allows for proper 1476 * recycling on high speed LANs while still leaving over an hour 1477 * before rollover. 1478 * 1479 * As reading the *exact* system time is too expensive to be done 1480 * whenever setting up a TCP connection, we increment the time 1481 * offset in two ways. First, a small random positive increment 1482 * is added to isn_offset for each connection that is set up. 1483 * Second, the function tcp_isn_tick fires once per clock tick 1484 * and increments isn_offset as necessary so that sequence numbers 1485 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1486 * random positive increments serve only to ensure that the same 1487 * exact sequence number is never sent out twice (as could otherwise 1488 * happen when a port is recycled in less than the system tick 1489 * interval.) 1490 * 1491 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1492 * between seeding of isn_secret. This is normally set to zero, 1493 * as reseeding should not be necessary. 1494 * 1495 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1496 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1497 * general, this means holding an exclusive (write) lock. 1498 */ 1499 1500 #define ISN_BYTES_PER_SECOND 1048576 1501 #define ISN_STATIC_INCREMENT 4096 1502 #define ISN_RANDOM_INCREMENT (4096 - 1) 1503 1504 #ifdef VIMAGE_GLOBALS 1505 static u_char isn_secret[32]; 1506 static int isn_last_reseed; 1507 static u_int32_t isn_offset, isn_offset_old; 1508 #endif 1509 1510 tcp_seq 1511 tcp_new_isn(struct tcpcb *tp) 1512 { 1513 INIT_VNET_INET(tp->t_vnet); 1514 MD5_CTX isn_ctx; 1515 u_int32_t md5_buffer[4]; 1516 tcp_seq new_isn; 1517 1518 INP_WLOCK_ASSERT(tp->t_inpcb); 1519 1520 ISN_LOCK(); 1521 /* Seed if this is the first use, reseed if requested. */ 1522 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1523 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1524 < (u_int)ticks))) { 1525 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1526 V_isn_last_reseed = ticks; 1527 } 1528 1529 /* Compute the md5 hash and return the ISN. */ 1530 MD5Init(&isn_ctx); 1531 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1532 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1533 #ifdef INET6 1534 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1535 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1536 sizeof(struct in6_addr)); 1537 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1538 sizeof(struct in6_addr)); 1539 } else 1540 #endif 1541 { 1542 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1543 sizeof(struct in_addr)); 1544 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1545 sizeof(struct in_addr)); 1546 } 1547 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1548 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1549 new_isn = (tcp_seq) md5_buffer[0]; 1550 V_isn_offset += ISN_STATIC_INCREMENT + 1551 (arc4random() & ISN_RANDOM_INCREMENT); 1552 new_isn += V_isn_offset; 1553 ISN_UNLOCK(); 1554 return (new_isn); 1555 } 1556 1557 /* 1558 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1559 * to keep time flowing at a relatively constant rate. If the random 1560 * increments have already pushed us past the projected offset, do nothing. 1561 */ 1562 static void 1563 tcp_isn_tick(void *xtp) 1564 { 1565 VNET_ITERATOR_DECL(vnet_iter); 1566 u_int32_t projected_offset; 1567 1568 VNET_LIST_RLOCK(); 1569 ISN_LOCK(); 1570 VNET_FOREACH(vnet_iter) { 1571 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 1572 INIT_VNET_INET(curvnet); 1573 projected_offset = 1574 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100; 1575 1576 if (SEQ_GT(projected_offset, V_isn_offset)) 1577 V_isn_offset = projected_offset; 1578 1579 V_isn_offset_old = V_isn_offset; 1580 CURVNET_RESTORE(); 1581 } 1582 ISN_UNLOCK(); 1583 VNET_LIST_RUNLOCK(); 1584 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 1585 } 1586 1587 /* 1588 * When a specific ICMP unreachable message is received and the 1589 * connection state is SYN-SENT, drop the connection. This behavior 1590 * is controlled by the icmp_may_rst sysctl. 1591 */ 1592 struct inpcb * 1593 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1594 { 1595 #ifdef INVARIANTS 1596 INIT_VNET_INET(inp->inp_vnet); 1597 #endif 1598 struct tcpcb *tp; 1599 1600 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1601 INP_WLOCK_ASSERT(inp); 1602 1603 if ((inp->inp_flags & INP_TIMEWAIT) || 1604 (inp->inp_flags & INP_DROPPED)) 1605 return (inp); 1606 1607 tp = intotcpcb(inp); 1608 if (tp->t_state != TCPS_SYN_SENT) 1609 return (inp); 1610 1611 tp = tcp_drop(tp, errno); 1612 if (tp != NULL) 1613 return (inp); 1614 else 1615 return (NULL); 1616 } 1617 1618 /* 1619 * When `need fragmentation' ICMP is received, update our idea of the MSS 1620 * based on the new value in the route. Also nudge TCP to send something, 1621 * since we know the packet we just sent was dropped. 1622 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1623 */ 1624 struct inpcb * 1625 tcp_mtudisc(struct inpcb *inp, int errno) 1626 { 1627 INIT_VNET_INET(inp->inp_vnet); 1628 struct tcpcb *tp; 1629 struct socket *so; 1630 1631 INP_WLOCK_ASSERT(inp); 1632 if ((inp->inp_flags & INP_TIMEWAIT) || 1633 (inp->inp_flags & INP_DROPPED)) 1634 return (inp); 1635 1636 tp = intotcpcb(inp); 1637 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1638 1639 tcp_mss_update(tp, -1, NULL, NULL); 1640 1641 so = inp->inp_socket; 1642 SOCKBUF_LOCK(&so->so_snd); 1643 /* If the mss is larger than the socket buffer, decrease the mss. */ 1644 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1645 tp->t_maxseg = so->so_snd.sb_hiwat; 1646 SOCKBUF_UNLOCK(&so->so_snd); 1647 1648 TCPSTAT_INC(tcps_mturesent); 1649 tp->t_rtttime = 0; 1650 tp->snd_nxt = tp->snd_una; 1651 tcp_free_sackholes(tp); 1652 tp->snd_recover = tp->snd_max; 1653 if (tp->t_flags & TF_SACK_PERMIT) 1654 EXIT_FASTRECOVERY(tp); 1655 tcp_output_send(tp); 1656 return (inp); 1657 } 1658 1659 /* 1660 * Look-up the routing entry to the peer of this inpcb. If no route 1661 * is found and it cannot be allocated, then return 0. This routine 1662 * is called by TCP routines that access the rmx structure and by 1663 * tcp_mss_update to get the peer/interface MTU. 1664 */ 1665 u_long 1666 tcp_maxmtu(struct in_conninfo *inc, int *flags) 1667 { 1668 struct route sro; 1669 struct sockaddr_in *dst; 1670 struct ifnet *ifp; 1671 u_long maxmtu = 0; 1672 1673 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1674 1675 bzero(&sro, sizeof(sro)); 1676 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1677 dst = (struct sockaddr_in *)&sro.ro_dst; 1678 dst->sin_family = AF_INET; 1679 dst->sin_len = sizeof(*dst); 1680 dst->sin_addr = inc->inc_faddr; 1681 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1682 } 1683 if (sro.ro_rt != NULL) { 1684 ifp = sro.ro_rt->rt_ifp; 1685 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1686 maxmtu = ifp->if_mtu; 1687 else 1688 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1689 1690 /* Report additional interface capabilities. */ 1691 if (flags != NULL) { 1692 if (ifp->if_capenable & IFCAP_TSO4 && 1693 ifp->if_hwassist & CSUM_TSO) 1694 *flags |= CSUM_TSO; 1695 } 1696 RTFREE(sro.ro_rt); 1697 } 1698 return (maxmtu); 1699 } 1700 1701 #ifdef INET6 1702 u_long 1703 tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1704 { 1705 struct route_in6 sro6; 1706 struct ifnet *ifp; 1707 u_long maxmtu = 0; 1708 1709 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1710 1711 bzero(&sro6, sizeof(sro6)); 1712 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1713 sro6.ro_dst.sin6_family = AF_INET6; 1714 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1715 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1716 rtalloc_ign((struct route *)&sro6, 0); 1717 } 1718 if (sro6.ro_rt != NULL) { 1719 ifp = sro6.ro_rt->rt_ifp; 1720 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1721 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1722 else 1723 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1724 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1725 1726 /* Report additional interface capabilities. */ 1727 if (flags != NULL) { 1728 if (ifp->if_capenable & IFCAP_TSO6 && 1729 ifp->if_hwassist & CSUM_TSO) 1730 *flags |= CSUM_TSO; 1731 } 1732 RTFREE(sro6.ro_rt); 1733 } 1734 1735 return (maxmtu); 1736 } 1737 #endif /* INET6 */ 1738 1739 #ifdef IPSEC 1740 /* compute ESP/AH header size for TCP, including outer IP header. */ 1741 size_t 1742 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1743 { 1744 struct inpcb *inp; 1745 struct mbuf *m; 1746 size_t hdrsiz; 1747 struct ip *ip; 1748 #ifdef INET6 1749 struct ip6_hdr *ip6; 1750 #endif 1751 struct tcphdr *th; 1752 1753 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1754 return (0); 1755 MGETHDR(m, M_DONTWAIT, MT_DATA); 1756 if (!m) 1757 return (0); 1758 1759 #ifdef INET6 1760 if ((inp->inp_vflag & INP_IPV6) != 0) { 1761 ip6 = mtod(m, struct ip6_hdr *); 1762 th = (struct tcphdr *)(ip6 + 1); 1763 m->m_pkthdr.len = m->m_len = 1764 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1765 tcpip_fillheaders(inp, ip6, th); 1766 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1767 } else 1768 #endif /* INET6 */ 1769 { 1770 ip = mtod(m, struct ip *); 1771 th = (struct tcphdr *)(ip + 1); 1772 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1773 tcpip_fillheaders(inp, ip, th); 1774 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1775 } 1776 1777 m_free(m); 1778 return (hdrsiz); 1779 } 1780 #endif /* IPSEC */ 1781 1782 /* 1783 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1784 * 1785 * This code attempts to calculate the bandwidth-delay product as a 1786 * means of determining the optimal window size to maximize bandwidth, 1787 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1788 * routers. This code also does a fairly good job keeping RTTs in check 1789 * across slow links like modems. We implement an algorithm which is very 1790 * similar (but not meant to be) TCP/Vegas. The code operates on the 1791 * transmitter side of a TCP connection and so only effects the transmit 1792 * side of the connection. 1793 * 1794 * BACKGROUND: TCP makes no provision for the management of buffer space 1795 * at the end points or at the intermediate routers and switches. A TCP 1796 * stream, whether using NewReno or not, will eventually buffer as 1797 * many packets as it is able and the only reason this typically works is 1798 * due to the fairly small default buffers made available for a connection 1799 * (typicaly 16K or 32K). As machines use larger windows and/or window 1800 * scaling it is now fairly easy for even a single TCP connection to blow-out 1801 * all available buffer space not only on the local interface, but on 1802 * intermediate routers and switches as well. NewReno makes a misguided 1803 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1804 * then backing off, then steadily increasing the window again until another 1805 * failure occurs, ad-infinitum. This results in terrible oscillation that 1806 * is only made worse as network loads increase and the idea of intentionally 1807 * blowing out network buffers is, frankly, a terrible way to manage network 1808 * resources. 1809 * 1810 * It is far better to limit the transmit window prior to the failure 1811 * condition being achieved. There are two general ways to do this: First 1812 * you can 'scan' through different transmit window sizes and locate the 1813 * point where the RTT stops increasing, indicating that you have filled the 1814 * pipe, then scan backwards until you note that RTT stops decreasing, then 1815 * repeat ad-infinitum. This method works in principle but has severe 1816 * implementation issues due to RTT variances, timer granularity, and 1817 * instability in the algorithm which can lead to many false positives and 1818 * create oscillations as well as interact badly with other TCP streams 1819 * implementing the same algorithm. 1820 * 1821 * The second method is to limit the window to the bandwidth delay product 1822 * of the link. This is the method we implement. RTT variances and our 1823 * own manipulation of the congestion window, bwnd, can potentially 1824 * destabilize the algorithm. For this reason we have to stabilize the 1825 * elements used to calculate the window. We do this by using the minimum 1826 * observed RTT, the long term average of the observed bandwidth, and 1827 * by adding two segments worth of slop. It isn't perfect but it is able 1828 * to react to changing conditions and gives us a very stable basis on 1829 * which to extend the algorithm. 1830 */ 1831 void 1832 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1833 { 1834 INIT_VNET_INET(tp->t_vnet); 1835 u_long bw; 1836 u_long bwnd; 1837 int save_ticks; 1838 1839 INP_WLOCK_ASSERT(tp->t_inpcb); 1840 1841 /* 1842 * If inflight_enable is disabled in the middle of a tcp connection, 1843 * make sure snd_bwnd is effectively disabled. 1844 */ 1845 if (V_tcp_inflight_enable == 0 || 1846 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1847 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1848 tp->snd_bandwidth = 0; 1849 return; 1850 } 1851 1852 /* 1853 * Figure out the bandwidth. Due to the tick granularity this 1854 * is a very rough number and it MUST be averaged over a fairly 1855 * long period of time. XXX we need to take into account a link 1856 * that is not using all available bandwidth, but for now our 1857 * slop will ramp us up if this case occurs and the bandwidth later 1858 * increases. 1859 * 1860 * Note: if ticks rollover 'bw' may wind up negative. We must 1861 * effectively reset t_bw_rtttime for this case. 1862 */ 1863 save_ticks = ticks; 1864 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1865 return; 1866 1867 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1868 (save_ticks - tp->t_bw_rtttime); 1869 tp->t_bw_rtttime = save_ticks; 1870 tp->t_bw_rtseq = ack_seq; 1871 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1872 return; 1873 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1874 1875 tp->snd_bandwidth = bw; 1876 1877 /* 1878 * Calculate the semi-static bandwidth delay product, plus two maximal 1879 * segments. The additional slop puts us squarely in the sweet 1880 * spot and also handles the bandwidth run-up case and stabilization. 1881 * Without the slop we could be locking ourselves into a lower 1882 * bandwidth. 1883 * 1884 * Situations Handled: 1885 * (1) Prevents over-queueing of packets on LANs, especially on 1886 * high speed LANs, allowing larger TCP buffers to be 1887 * specified, and also does a good job preventing 1888 * over-queueing of packets over choke points like modems 1889 * (at least for the transmit side). 1890 * 1891 * (2) Is able to handle changing network loads (bandwidth 1892 * drops so bwnd drops, bandwidth increases so bwnd 1893 * increases). 1894 * 1895 * (3) Theoretically should stabilize in the face of multiple 1896 * connections implementing the same algorithm (this may need 1897 * a little work). 1898 * 1899 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1900 * be adjusted with a sysctl but typically only needs to be 1901 * on very slow connections. A value no smaller then 5 1902 * should be used, but only reduce this default if you have 1903 * no other choice. 1904 */ 1905 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1906 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1907 #undef USERTT 1908 1909 if (tcp_inflight_debug > 0) { 1910 static int ltime; 1911 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1912 ltime = ticks; 1913 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1914 tp, 1915 bw, 1916 tp->t_rttbest, 1917 tp->t_srtt, 1918 bwnd 1919 ); 1920 } 1921 } 1922 if ((long)bwnd < V_tcp_inflight_min) 1923 bwnd = V_tcp_inflight_min; 1924 if (bwnd > V_tcp_inflight_max) 1925 bwnd = V_tcp_inflight_max; 1926 if ((long)bwnd < tp->t_maxseg * 2) 1927 bwnd = tp->t_maxseg * 2; 1928 tp->snd_bwnd = bwnd; 1929 } 1930 1931 #ifdef TCP_SIGNATURE 1932 /* 1933 * Callback function invoked by m_apply() to digest TCP segment data 1934 * contained within an mbuf chain. 1935 */ 1936 static int 1937 tcp_signature_apply(void *fstate, void *data, u_int len) 1938 { 1939 1940 MD5Update(fstate, (u_char *)data, len); 1941 return (0); 1942 } 1943 1944 /* 1945 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1946 * 1947 * Parameters: 1948 * m pointer to head of mbuf chain 1949 * _unused 1950 * len length of TCP segment data, excluding options 1951 * optlen length of TCP segment options 1952 * buf pointer to storage for computed MD5 digest 1953 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1954 * 1955 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1956 * When called from tcp_input(), we can be sure that th_sum has been 1957 * zeroed out and verified already. 1958 * 1959 * Return 0 if successful, otherwise return -1. 1960 * 1961 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1962 * search with the destination IP address, and a 'magic SPI' to be 1963 * determined by the application. This is hardcoded elsewhere to 1179 1964 * right now. Another branch of this code exists which uses the SPD to 1965 * specify per-application flows but it is unstable. 1966 */ 1967 int 1968 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1969 u_char *buf, u_int direction) 1970 { 1971 INIT_VNET_IPSEC(curvnet); 1972 union sockaddr_union dst; 1973 struct ippseudo ippseudo; 1974 MD5_CTX ctx; 1975 int doff; 1976 struct ip *ip; 1977 struct ipovly *ipovly; 1978 struct secasvar *sav; 1979 struct tcphdr *th; 1980 #ifdef INET6 1981 struct ip6_hdr *ip6; 1982 struct in6_addr in6; 1983 char ip6buf[INET6_ADDRSTRLEN]; 1984 uint32_t plen; 1985 uint16_t nhdr; 1986 #endif 1987 u_short savecsum; 1988 1989 KASSERT(m != NULL, ("NULL mbuf chain")); 1990 KASSERT(buf != NULL, ("NULL signature pointer")); 1991 1992 /* Extract the destination from the IP header in the mbuf. */ 1993 bzero(&dst, sizeof(union sockaddr_union)); 1994 ip = mtod(m, struct ip *); 1995 #ifdef INET6 1996 ip6 = NULL; /* Make the compiler happy. */ 1997 #endif 1998 switch (ip->ip_v) { 1999 case IPVERSION: 2000 dst.sa.sa_len = sizeof(struct sockaddr_in); 2001 dst.sa.sa_family = AF_INET; 2002 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2003 ip->ip_src : ip->ip_dst; 2004 break; 2005 #ifdef INET6 2006 case (IPV6_VERSION >> 4): 2007 ip6 = mtod(m, struct ip6_hdr *); 2008 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2009 dst.sa.sa_family = AF_INET6; 2010 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2011 ip6->ip6_src : ip6->ip6_dst; 2012 break; 2013 #endif 2014 default: 2015 return (EINVAL); 2016 /* NOTREACHED */ 2017 break; 2018 } 2019 2020 /* Look up an SADB entry which matches the address of the peer. */ 2021 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2022 if (sav == NULL) { 2023 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2024 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2025 #ifdef INET6 2026 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2027 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2028 #endif 2029 "(unsupported)")); 2030 return (EINVAL); 2031 } 2032 2033 MD5Init(&ctx); 2034 /* 2035 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2036 * 2037 * XXX The ippseudo header MUST be digested in network byte order, 2038 * or else we'll fail the regression test. Assume all fields we've 2039 * been doing arithmetic on have been in host byte order. 2040 * XXX One cannot depend on ipovly->ih_len here. When called from 2041 * tcp_output(), the underlying ip_len member has not yet been set. 2042 */ 2043 switch (ip->ip_v) { 2044 case IPVERSION: 2045 ipovly = (struct ipovly *)ip; 2046 ippseudo.ippseudo_src = ipovly->ih_src; 2047 ippseudo.ippseudo_dst = ipovly->ih_dst; 2048 ippseudo.ippseudo_pad = 0; 2049 ippseudo.ippseudo_p = IPPROTO_TCP; 2050 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2051 optlen); 2052 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2053 2054 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2055 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2056 break; 2057 #ifdef INET6 2058 /* 2059 * RFC 2385, 2.0 Proposal 2060 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2061 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2062 * extended next header value (to form 32 bits), and 32-bit segment 2063 * length. 2064 * Note: Upper-Layer Packet Length comes before Next Header. 2065 */ 2066 case (IPV6_VERSION >> 4): 2067 in6 = ip6->ip6_src; 2068 in6_clearscope(&in6); 2069 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2070 in6 = ip6->ip6_dst; 2071 in6_clearscope(&in6); 2072 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2073 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2074 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2075 nhdr = 0; 2076 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2077 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2078 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2079 nhdr = IPPROTO_TCP; 2080 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2081 2082 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2083 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2084 break; 2085 #endif 2086 default: 2087 return (EINVAL); 2088 /* NOTREACHED */ 2089 break; 2090 } 2091 2092 2093 /* 2094 * Step 2: Update MD5 hash with TCP header, excluding options. 2095 * The TCP checksum must be set to zero. 2096 */ 2097 savecsum = th->th_sum; 2098 th->th_sum = 0; 2099 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2100 th->th_sum = savecsum; 2101 2102 /* 2103 * Step 3: Update MD5 hash with TCP segment data. 2104 * Use m_apply() to avoid an early m_pullup(). 2105 */ 2106 if (len > 0) 2107 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2108 2109 /* 2110 * Step 4: Update MD5 hash with shared secret. 2111 */ 2112 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2113 MD5Final(buf, &ctx); 2114 2115 key_sa_recordxfer(sav, m); 2116 KEY_FREESAV(&sav); 2117 return (0); 2118 } 2119 #endif /* TCP_SIGNATURE */ 2120 2121 static int 2122 sysctl_drop(SYSCTL_HANDLER_ARGS) 2123 { 2124 INIT_VNET_INET(curvnet); 2125 #ifdef INET6 2126 INIT_VNET_INET6(curvnet); 2127 #endif 2128 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2129 struct sockaddr_storage addrs[2]; 2130 struct inpcb *inp; 2131 struct tcpcb *tp; 2132 struct tcptw *tw; 2133 struct sockaddr_in *fin, *lin; 2134 #ifdef INET6 2135 struct sockaddr_in6 *fin6, *lin6; 2136 #endif 2137 int error; 2138 2139 inp = NULL; 2140 fin = lin = NULL; 2141 #ifdef INET6 2142 fin6 = lin6 = NULL; 2143 #endif 2144 error = 0; 2145 2146 if (req->oldptr != NULL || req->oldlen != 0) 2147 return (EINVAL); 2148 if (req->newptr == NULL) 2149 return (EPERM); 2150 if (req->newlen < sizeof(addrs)) 2151 return (ENOMEM); 2152 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2153 if (error) 2154 return (error); 2155 2156 switch (addrs[0].ss_family) { 2157 #ifdef INET6 2158 case AF_INET6: 2159 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2160 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2161 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2162 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2163 return (EINVAL); 2164 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2165 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2166 return (EINVAL); 2167 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2168 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2169 fin = (struct sockaddr_in *)&addrs[0]; 2170 lin = (struct sockaddr_in *)&addrs[1]; 2171 break; 2172 } 2173 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2174 if (error) 2175 return (error); 2176 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2177 if (error) 2178 return (error); 2179 break; 2180 #endif 2181 case AF_INET: 2182 fin = (struct sockaddr_in *)&addrs[0]; 2183 lin = (struct sockaddr_in *)&addrs[1]; 2184 if (fin->sin_len != sizeof(struct sockaddr_in) || 2185 lin->sin_len != sizeof(struct sockaddr_in)) 2186 return (EINVAL); 2187 break; 2188 default: 2189 return (EINVAL); 2190 } 2191 INP_INFO_WLOCK(&V_tcbinfo); 2192 switch (addrs[0].ss_family) { 2193 #ifdef INET6 2194 case AF_INET6: 2195 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2196 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2197 NULL); 2198 break; 2199 #endif 2200 case AF_INET: 2201 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2202 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2203 break; 2204 } 2205 if (inp != NULL) { 2206 INP_WLOCK(inp); 2207 if (inp->inp_flags & INP_TIMEWAIT) { 2208 /* 2209 * XXXRW: There currently exists a state where an 2210 * inpcb is present, but its timewait state has been 2211 * discarded. For now, don't allow dropping of this 2212 * type of inpcb. 2213 */ 2214 tw = intotw(inp); 2215 if (tw != NULL) 2216 tcp_twclose(tw, 0); 2217 else 2218 INP_WUNLOCK(inp); 2219 } else if (!(inp->inp_flags & INP_DROPPED) && 2220 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2221 tp = intotcpcb(inp); 2222 tp = tcp_drop(tp, ECONNABORTED); 2223 if (tp != NULL) 2224 INP_WUNLOCK(inp); 2225 } else 2226 INP_WUNLOCK(inp); 2227 } else 2228 error = ESRCH; 2229 INP_INFO_WUNLOCK(&V_tcbinfo); 2230 return (error); 2231 } 2232 2233 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2234 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2235 0, sysctl_drop, "", "Drop TCP connection"); 2236 2237 /* 2238 * Generate a standardized TCP log line for use throughout the 2239 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2240 * allow use in the interrupt context. 2241 * 2242 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2243 * NB: The function may return NULL if memory allocation failed. 2244 * 2245 * Due to header inclusion and ordering limitations the struct ip 2246 * and ip6_hdr pointers have to be passed as void pointers. 2247 */ 2248 char * 2249 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2250 const void *ip6hdr) 2251 { 2252 char *s, *sp; 2253 size_t size; 2254 struct ip *ip; 2255 #ifdef INET6 2256 const struct ip6_hdr *ip6; 2257 2258 ip6 = (const struct ip6_hdr *)ip6hdr; 2259 #endif /* INET6 */ 2260 ip = (struct ip *)ip4hdr; 2261 2262 /* 2263 * The log line looks like this: 2264 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2265 */ 2266 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2267 sizeof(PRINT_TH_FLAGS) + 1 + 2268 #ifdef INET6 2269 2 * INET6_ADDRSTRLEN; 2270 #else 2271 2 * INET_ADDRSTRLEN; 2272 #endif /* INET6 */ 2273 2274 /* Is logging enabled? */ 2275 if (tcp_log_debug == 0 && tcp_log_in_vain == 0) 2276 return (NULL); 2277 2278 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2279 if (s == NULL) 2280 return (NULL); 2281 2282 strcat(s, "TCP: ["); 2283 sp = s + strlen(s); 2284 2285 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2286 inet_ntoa_r(inc->inc_faddr, sp); 2287 sp = s + strlen(s); 2288 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2289 sp = s + strlen(s); 2290 inet_ntoa_r(inc->inc_laddr, sp); 2291 sp = s + strlen(s); 2292 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2293 #ifdef INET6 2294 } else if (inc) { 2295 ip6_sprintf(sp, &inc->inc6_faddr); 2296 sp = s + strlen(s); 2297 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2298 sp = s + strlen(s); 2299 ip6_sprintf(sp, &inc->inc6_laddr); 2300 sp = s + strlen(s); 2301 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2302 } else if (ip6 && th) { 2303 ip6_sprintf(sp, &ip6->ip6_src); 2304 sp = s + strlen(s); 2305 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2306 sp = s + strlen(s); 2307 ip6_sprintf(sp, &ip6->ip6_dst); 2308 sp = s + strlen(s); 2309 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2310 #endif /* INET6 */ 2311 } else if (ip && th) { 2312 inet_ntoa_r(ip->ip_src, sp); 2313 sp = s + strlen(s); 2314 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2315 sp = s + strlen(s); 2316 inet_ntoa_r(ip->ip_dst, sp); 2317 sp = s + strlen(s); 2318 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2319 } else { 2320 free(s, M_TCPLOG); 2321 return (NULL); 2322 } 2323 sp = s + strlen(s); 2324 if (th) 2325 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2326 if (*(s + size - 1) != '\0') 2327 panic("%s: string too long", __func__); 2328 return (s); 2329 } 2330