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 59 #include <vm/uma.h> 60 61 #include <net/route.h> 62 #include <net/if.h> 63 #include <net/vnet.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 <netinet6/ip6protosw.h> 98 99 #ifdef IPSEC 100 #include <netipsec/ipsec.h> 101 #include <netipsec/xform.h> 102 #ifdef INET6 103 #include <netipsec/ipsec6.h> 104 #endif 105 #include <netipsec/key.h> 106 #include <sys/syslog.h> 107 #endif /*IPSEC*/ 108 109 #include <machine/in_cksum.h> 110 #include <sys/md5.h> 111 112 #include <security/mac/mac_framework.h> 113 114 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 115 #ifdef INET6 116 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 117 #endif 118 119 static int 120 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 121 { 122 int error, new; 123 124 new = V_tcp_mssdflt; 125 error = sysctl_handle_int(oidp, &new, 0, req); 126 if (error == 0 && req->newptr) { 127 if (new < TCP_MINMSS) 128 error = EINVAL; 129 else 130 V_tcp_mssdflt = new; 131 } 132 return (error); 133 } 134 135 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 136 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 137 &sysctl_net_inet_tcp_mss_check, "I", 138 "Default TCP Maximum Segment Size"); 139 140 #ifdef INET6 141 static int 142 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 143 { 144 int error, new; 145 146 new = V_tcp_v6mssdflt; 147 error = sysctl_handle_int(oidp, &new, 0, req); 148 if (error == 0 && req->newptr) { 149 if (new < TCP_MINMSS) 150 error = EINVAL; 151 else 152 V_tcp_v6mssdflt = new; 153 } 154 return (error); 155 } 156 157 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 158 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 159 &sysctl_net_inet_tcp_mss_v6_check, "I", 160 "Default TCP Maximum Segment Size for IPv6"); 161 #endif 162 163 static int 164 vnet_sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 165 { 166 167 VNET_SYSCTL_ARG(req, arg1); 168 return (sysctl_msec_to_ticks(oidp, arg1, arg2, req)); 169 } 170 171 /* 172 * Minimum MSS we accept and use. This prevents DoS attacks where 173 * we are forced to a ridiculous low MSS like 20 and send hundreds 174 * of packets instead of one. The effect scales with the available 175 * bandwidth and quickly saturates the CPU and network interface 176 * with packet generation and sending. Set to zero to disable MINMSS 177 * checking. This setting prevents us from sending too small packets. 178 */ 179 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 180 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 181 &VNET_NAME(tcp_minmss), 0, 182 "Minmum TCP Maximum Segment Size"); 183 184 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 185 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 186 &VNET_NAME(tcp_do_rfc1323), 0, 187 "Enable rfc1323 (high performance TCP) extensions"); 188 189 static int tcp_log_debug = 0; 190 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 191 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 192 193 static int tcp_tcbhashsize = 0; 194 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 195 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 196 197 static int do_tcpdrain = 1; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 199 "Enable tcp_drain routine for extra help when low on mbufs"); 200 201 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 202 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 203 204 static VNET_DEFINE(int, icmp_may_rst) = 1; 205 #define V_icmp_may_rst VNET(icmp_may_rst) 206 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, 207 &VNET_NAME(icmp_may_rst), 0, 208 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 209 210 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 211 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 212 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 213 &VNET_NAME(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 static VNET_DEFINE(int, tcp_inflight_enable) = 0; 225 #define V_tcp_inflight_enable VNET(tcp_inflight_enable) 226 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, enable, CTLFLAG_RW, 227 &VNET_NAME(tcp_inflight_enable), 0, 228 "Enable automatic TCP inflight data limiting"); 229 230 static int tcp_inflight_debug = 0; 231 SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW, 232 &tcp_inflight_debug, 0, 233 "Debug TCP inflight calculations"); 234 235 static VNET_DEFINE(int, tcp_inflight_rttthresh); 236 #define V_tcp_inflight_rttthresh VNET(tcp_inflight_rttthresh) 237 SYSCTL_VNET_PROC(_net_inet_tcp_inflight, OID_AUTO, rttthresh, 238 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_inflight_rttthresh), 0, 239 vnet_sysctl_msec_to_ticks, "I", 240 "RTT threshold below which inflight will deactivate itself"); 241 242 static VNET_DEFINE(int, tcp_inflight_min) = 6144; 243 #define V_tcp_inflight_min VNET(tcp_inflight_min) 244 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, min, CTLFLAG_RW, 245 &VNET_NAME(tcp_inflight_min), 0, 246 "Lower-bound for TCP inflight window"); 247 248 static VNET_DEFINE(int, tcp_inflight_max) = TCP_MAXWIN << TCP_MAX_WINSHIFT; 249 #define V_tcp_inflight_max VNET(tcp_inflight_max) 250 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, max, CTLFLAG_RW, 251 &VNET_NAME(tcp_inflight_max), 0, 252 "Upper-bound for TCP inflight window"); 253 254 static VNET_DEFINE(int, tcp_inflight_stab) = 20; 255 #define V_tcp_inflight_stab VNET(tcp_inflight_stab) 256 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, stab, CTLFLAG_RW, 257 &VNET_NAME(tcp_inflight_stab), 0, 258 "Inflight Algorithm Stabilization 20 = 2 packets"); 259 260 #ifdef TCP_SORECEIVE_STREAM 261 static int tcp_soreceive_stream = 0; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 263 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 264 #endif 265 266 VNET_DEFINE(uma_zone_t, sack_hole_zone); 267 #define V_sack_hole_zone VNET(sack_hole_zone) 268 269 static struct inpcb *tcp_notify(struct inpcb *, int); 270 static void tcp_isn_tick(void *); 271 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 272 void *ip4hdr, const void *ip6hdr); 273 274 /* 275 * Target size of TCP PCB hash tables. Must be a power of two. 276 * 277 * Note that this can be overridden by the kernel environment 278 * variable net.inet.tcp.tcbhashsize 279 */ 280 #ifndef TCBHASHSIZE 281 #define TCBHASHSIZE 512 282 #endif 283 284 /* 285 * XXX 286 * Callouts should be moved into struct tcp directly. They are currently 287 * separate because the tcpcb structure is exported to userland for sysctl 288 * parsing purposes, which do not know about callouts. 289 */ 290 struct tcpcb_mem { 291 struct tcpcb tcb; 292 struct tcp_timer tt; 293 }; 294 295 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 296 #define V_tcpcb_zone VNET(tcpcb_zone) 297 298 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 299 struct callout isn_callout; 300 static struct mtx isn_mtx; 301 302 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 303 #define ISN_LOCK() mtx_lock(&isn_mtx) 304 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 305 306 /* 307 * TCP initialization. 308 */ 309 static void 310 tcp_zone_change(void *tag) 311 { 312 313 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 314 uma_zone_set_max(V_tcpcb_zone, maxsockets); 315 tcp_tw_zone_change(); 316 } 317 318 static int 319 tcp_inpcb_init(void *mem, int size, int flags) 320 { 321 struct inpcb *inp = mem; 322 323 INP_LOCK_INIT(inp, "inp", "tcpinp"); 324 return (0); 325 } 326 327 void 328 tcp_init(void) 329 { 330 int hashsize; 331 332 hashsize = TCBHASHSIZE; 333 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 334 if (!powerof2(hashsize)) { 335 printf("WARNING: TCB hash size not a power of 2\n"); 336 hashsize = 512; /* safe default */ 337 } 338 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 339 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE); 340 341 V_tcp_inflight_rttthresh = TCPTV_INFLIGHT_RTTTHRESH; 342 343 /* 344 * These have to be type stable for the benefit of the timers. 345 */ 346 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 347 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 348 uma_zone_set_max(V_tcpcb_zone, maxsockets); 349 350 tcp_tw_init(); 351 syncache_init(); 352 tcp_hc_init(); 353 tcp_reass_init(); 354 355 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 356 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 357 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 358 359 /* Skip initialization of globals for non-default instances. */ 360 if (!IS_DEFAULT_VNET(curvnet)) 361 return; 362 363 /* XXX virtualize those bellow? */ 364 tcp_delacktime = TCPTV_DELACK; 365 tcp_keepinit = TCPTV_KEEP_INIT; 366 tcp_keepidle = TCPTV_KEEP_IDLE; 367 tcp_keepintvl = TCPTV_KEEPINTVL; 368 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 369 tcp_msl = TCPTV_MSL; 370 tcp_rexmit_min = TCPTV_MIN; 371 if (tcp_rexmit_min < 1) 372 tcp_rexmit_min = 1; 373 tcp_rexmit_slop = TCPTV_CPU_VAR; 374 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 375 tcp_tcbhashsize = hashsize; 376 377 #ifdef TCP_SORECEIVE_STREAM 378 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 379 if (tcp_soreceive_stream) { 380 tcp_usrreqs.pru_soreceive = soreceive_stream; 381 tcp6_usrreqs.pru_soreceive = soreceive_stream; 382 } 383 #endif 384 385 #ifdef INET6 386 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 387 #else /* INET6 */ 388 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 389 #endif /* INET6 */ 390 if (max_protohdr < TCP_MINPROTOHDR) 391 max_protohdr = TCP_MINPROTOHDR; 392 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 393 panic("tcp_init"); 394 #undef TCP_MINPROTOHDR 395 396 ISN_LOCK_INIT(); 397 callout_init(&isn_callout, CALLOUT_MPSAFE); 398 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 399 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 400 SHUTDOWN_PRI_DEFAULT); 401 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 402 EVENTHANDLER_PRI_ANY); 403 } 404 405 #ifdef VIMAGE 406 void 407 tcp_destroy(void) 408 { 409 410 tcp_reass_destroy(); 411 tcp_hc_destroy(); 412 syncache_destroy(); 413 tcp_tw_destroy(); 414 in_pcbinfo_destroy(&V_tcbinfo); 415 uma_zdestroy(V_sack_hole_zone); 416 uma_zdestroy(V_tcpcb_zone); 417 } 418 #endif 419 420 void 421 tcp_fini(void *xtp) 422 { 423 424 callout_stop(&isn_callout); 425 } 426 427 /* 428 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 429 * tcp_template used to store this data in mbufs, but we now recopy it out 430 * of the tcpcb each time to conserve mbufs. 431 */ 432 void 433 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 434 { 435 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 436 437 INP_WLOCK_ASSERT(inp); 438 439 #ifdef INET6 440 if ((inp->inp_vflag & INP_IPV6) != 0) { 441 struct ip6_hdr *ip6; 442 443 ip6 = (struct ip6_hdr *)ip_ptr; 444 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 445 (inp->inp_flow & IPV6_FLOWINFO_MASK); 446 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 447 (IPV6_VERSION & IPV6_VERSION_MASK); 448 ip6->ip6_nxt = IPPROTO_TCP; 449 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 450 ip6->ip6_src = inp->in6p_laddr; 451 ip6->ip6_dst = inp->in6p_faddr; 452 } else 453 #endif 454 { 455 struct ip *ip; 456 457 ip = (struct ip *)ip_ptr; 458 ip->ip_v = IPVERSION; 459 ip->ip_hl = 5; 460 ip->ip_tos = inp->inp_ip_tos; 461 ip->ip_len = 0; 462 ip->ip_id = 0; 463 ip->ip_off = 0; 464 ip->ip_ttl = inp->inp_ip_ttl; 465 ip->ip_sum = 0; 466 ip->ip_p = IPPROTO_TCP; 467 ip->ip_src = inp->inp_laddr; 468 ip->ip_dst = inp->inp_faddr; 469 } 470 th->th_sport = inp->inp_lport; 471 th->th_dport = inp->inp_fport; 472 th->th_seq = 0; 473 th->th_ack = 0; 474 th->th_x2 = 0; 475 th->th_off = 5; 476 th->th_flags = 0; 477 th->th_win = 0; 478 th->th_urp = 0; 479 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 480 } 481 482 /* 483 * Create template to be used to send tcp packets on a connection. 484 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 485 * use for this function is in keepalives, which use tcp_respond. 486 */ 487 struct tcptemp * 488 tcpip_maketemplate(struct inpcb *inp) 489 { 490 struct tcptemp *t; 491 492 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 493 if (t == NULL) 494 return (NULL); 495 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 496 return (t); 497 } 498 499 /* 500 * Send a single message to the TCP at address specified by 501 * the given TCP/IP header. If m == NULL, then we make a copy 502 * of the tcpiphdr at ti and send directly to the addressed host. 503 * This is used to force keep alive messages out using the TCP 504 * template for a connection. If flags are given then we send 505 * a message back to the TCP which originated the * segment ti, 506 * and discard the mbuf containing it and any other attached mbufs. 507 * 508 * In any case the ack and sequence number of the transmitted 509 * segment are as specified by the parameters. 510 * 511 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 512 */ 513 void 514 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 515 tcp_seq ack, tcp_seq seq, int flags) 516 { 517 int tlen; 518 int win = 0; 519 struct ip *ip; 520 struct tcphdr *nth; 521 #ifdef INET6 522 struct ip6_hdr *ip6; 523 int isipv6; 524 #endif /* INET6 */ 525 int ipflags = 0; 526 struct inpcb *inp; 527 528 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 529 530 #ifdef INET6 531 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 532 ip6 = ipgen; 533 #endif /* INET6 */ 534 ip = ipgen; 535 536 if (tp != NULL) { 537 inp = tp->t_inpcb; 538 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 539 INP_WLOCK_ASSERT(inp); 540 } else 541 inp = NULL; 542 543 if (tp != NULL) { 544 if (!(flags & TH_RST)) { 545 win = sbspace(&inp->inp_socket->so_rcv); 546 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 547 win = (long)TCP_MAXWIN << tp->rcv_scale; 548 } 549 } 550 if (m == NULL) { 551 m = m_gethdr(M_DONTWAIT, MT_DATA); 552 if (m == NULL) 553 return; 554 tlen = 0; 555 m->m_data += max_linkhdr; 556 #ifdef INET6 557 if (isipv6) { 558 bcopy((caddr_t)ip6, mtod(m, caddr_t), 559 sizeof(struct ip6_hdr)); 560 ip6 = mtod(m, struct ip6_hdr *); 561 nth = (struct tcphdr *)(ip6 + 1); 562 } else 563 #endif /* INET6 */ 564 { 565 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 566 ip = mtod(m, struct ip *); 567 nth = (struct tcphdr *)(ip + 1); 568 } 569 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 570 flags = TH_ACK; 571 } else { 572 /* 573 * reuse the mbuf. 574 * XXX MRT We inherrit the FIB, which is lucky. 575 */ 576 m_freem(m->m_next); 577 m->m_next = NULL; 578 m->m_data = (caddr_t)ipgen; 579 /* m_len is set later */ 580 tlen = 0; 581 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 582 #ifdef INET6 583 if (isipv6) { 584 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 585 nth = (struct tcphdr *)(ip6 + 1); 586 } else 587 #endif /* INET6 */ 588 { 589 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 590 nth = (struct tcphdr *)(ip + 1); 591 } 592 if (th != nth) { 593 /* 594 * this is usually a case when an extension header 595 * exists between the IPv6 header and the 596 * TCP header. 597 */ 598 nth->th_sport = th->th_sport; 599 nth->th_dport = th->th_dport; 600 } 601 xchg(nth->th_dport, nth->th_sport, uint16_t); 602 #undef xchg 603 } 604 #ifdef INET6 605 if (isipv6) { 606 ip6->ip6_flow = 0; 607 ip6->ip6_vfc = IPV6_VERSION; 608 ip6->ip6_nxt = IPPROTO_TCP; 609 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 610 tlen)); 611 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 612 } else 613 #endif 614 { 615 tlen += sizeof (struct tcpiphdr); 616 ip->ip_len = tlen; 617 ip->ip_ttl = V_ip_defttl; 618 if (V_path_mtu_discovery) 619 ip->ip_off |= IP_DF; 620 } 621 m->m_len = tlen; 622 m->m_pkthdr.len = tlen; 623 m->m_pkthdr.rcvif = NULL; 624 #ifdef MAC 625 if (inp != NULL) { 626 /* 627 * Packet is associated with a socket, so allow the 628 * label of the response to reflect the socket label. 629 */ 630 INP_WLOCK_ASSERT(inp); 631 mac_inpcb_create_mbuf(inp, m); 632 } else { 633 /* 634 * Packet is not associated with a socket, so possibly 635 * update the label in place. 636 */ 637 mac_netinet_tcp_reply(m); 638 } 639 #endif 640 nth->th_seq = htonl(seq); 641 nth->th_ack = htonl(ack); 642 nth->th_x2 = 0; 643 nth->th_off = sizeof (struct tcphdr) >> 2; 644 nth->th_flags = flags; 645 if (tp != NULL) 646 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 647 else 648 nth->th_win = htons((u_short)win); 649 nth->th_urp = 0; 650 #ifdef INET6 651 if (isipv6) { 652 nth->th_sum = 0; 653 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 654 sizeof(struct ip6_hdr), 655 tlen - sizeof(struct ip6_hdr)); 656 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 657 NULL, NULL); 658 } else 659 #endif /* INET6 */ 660 { 661 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 662 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 663 m->m_pkthdr.csum_flags = CSUM_TCP; 664 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 665 } 666 #ifdef TCPDEBUG 667 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 668 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 669 #endif 670 #ifdef INET6 671 if (isipv6) 672 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 673 else 674 #endif /* INET6 */ 675 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 676 } 677 678 /* 679 * Create a new TCP control block, making an 680 * empty reassembly queue and hooking it to the argument 681 * protocol control block. The `inp' parameter must have 682 * come from the zone allocator set up in tcp_init(). 683 */ 684 struct tcpcb * 685 tcp_newtcpcb(struct inpcb *inp) 686 { 687 struct tcpcb_mem *tm; 688 struct tcpcb *tp; 689 #ifdef INET6 690 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 691 #endif /* INET6 */ 692 693 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 694 if (tm == NULL) 695 return (NULL); 696 tp = &tm->tcb; 697 #ifdef VIMAGE 698 tp->t_vnet = inp->inp_vnet; 699 #endif 700 tp->t_timers = &tm->tt; 701 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 702 tp->t_maxseg = tp->t_maxopd = 703 #ifdef INET6 704 isipv6 ? V_tcp_v6mssdflt : 705 #endif /* INET6 */ 706 V_tcp_mssdflt; 707 708 /* Set up our timeouts. */ 709 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 710 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 711 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 712 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 713 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 714 715 if (V_tcp_do_rfc1323) 716 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 717 if (V_tcp_do_sack) 718 tp->t_flags |= TF_SACK_PERMIT; 719 TAILQ_INIT(&tp->snd_holes); 720 tp->t_inpcb = inp; /* XXX */ 721 /* 722 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 723 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 724 * reasonable initial retransmit time. 725 */ 726 tp->t_srtt = TCPTV_SRTTBASE; 727 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 728 tp->t_rttmin = tcp_rexmit_min; 729 tp->t_rxtcur = TCPTV_RTOBASE; 730 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 731 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 732 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 733 tp->t_rcvtime = ticks; 734 tp->t_bw_rtttime = ticks; 735 /* 736 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 737 * because the socket may be bound to an IPv6 wildcard address, 738 * which may match an IPv4-mapped IPv6 address. 739 */ 740 inp->inp_ip_ttl = V_ip_defttl; 741 inp->inp_ppcb = tp; 742 return (tp); /* XXX */ 743 } 744 745 /* 746 * Drop a TCP connection, reporting 747 * the specified error. If connection is synchronized, 748 * then send a RST to peer. 749 */ 750 struct tcpcb * 751 tcp_drop(struct tcpcb *tp, int errno) 752 { 753 struct socket *so = tp->t_inpcb->inp_socket; 754 755 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 756 INP_WLOCK_ASSERT(tp->t_inpcb); 757 758 if (TCPS_HAVERCVDSYN(tp->t_state)) { 759 tp->t_state = TCPS_CLOSED; 760 (void) tcp_output_reset(tp); 761 TCPSTAT_INC(tcps_drops); 762 } else 763 TCPSTAT_INC(tcps_conndrops); 764 if (errno == ETIMEDOUT && tp->t_softerror) 765 errno = tp->t_softerror; 766 so->so_error = errno; 767 return (tcp_close(tp)); 768 } 769 770 void 771 tcp_discardcb(struct tcpcb *tp) 772 { 773 struct tseg_qent *q; 774 struct inpcb *inp = tp->t_inpcb; 775 struct socket *so = inp->inp_socket; 776 #ifdef INET6 777 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 778 #endif /* INET6 */ 779 780 INP_WLOCK_ASSERT(inp); 781 782 /* 783 * Make sure that all of our timers are stopped before we delete the 784 * PCB. 785 * 786 * XXXRW: Really, we would like to use callout_drain() here in order 787 * to avoid races experienced in tcp_timer.c where a timer is already 788 * executing at this point. However, we can't, both because we're 789 * running in a context where we can't sleep, and also because we 790 * hold locks required by the timers. What we instead need to do is 791 * test to see if callout_drain() is required, and if so, defer some 792 * portion of the remainder of tcp_discardcb() to an asynchronous 793 * context that can callout_drain() and then continue. Some care 794 * will be required to ensure that no further processing takes place 795 * on the tcpcb, even though it hasn't been freed (a flag?). 796 */ 797 callout_stop(&tp->t_timers->tt_rexmt); 798 callout_stop(&tp->t_timers->tt_persist); 799 callout_stop(&tp->t_timers->tt_keep); 800 callout_stop(&tp->t_timers->tt_2msl); 801 callout_stop(&tp->t_timers->tt_delack); 802 803 /* 804 * If we got enough samples through the srtt filter, 805 * save the rtt and rttvar in the routing entry. 806 * 'Enough' is arbitrarily defined as 4 rtt samples. 807 * 4 samples is enough for the srtt filter to converge 808 * to within enough % of the correct value; fewer samples 809 * and we could save a bogus rtt. The danger is not high 810 * as tcp quickly recovers from everything. 811 * XXX: Works very well but needs some more statistics! 812 */ 813 if (tp->t_rttupdated >= 4) { 814 struct hc_metrics_lite metrics; 815 u_long ssthresh; 816 817 bzero(&metrics, sizeof(metrics)); 818 /* 819 * Update the ssthresh always when the conditions below 820 * are satisfied. This gives us better new start value 821 * for the congestion avoidance for new connections. 822 * ssthresh is only set if packet loss occured on a session. 823 * 824 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 825 * being torn down. Ideally this code would not use 'so'. 826 */ 827 ssthresh = tp->snd_ssthresh; 828 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 829 /* 830 * convert the limit from user data bytes to 831 * packets then to packet data bytes. 832 */ 833 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 834 if (ssthresh < 2) 835 ssthresh = 2; 836 ssthresh *= (u_long)(tp->t_maxseg + 837 #ifdef INET6 838 (isipv6 ? sizeof (struct ip6_hdr) + 839 sizeof (struct tcphdr) : 840 #endif 841 sizeof (struct tcpiphdr) 842 #ifdef INET6 843 ) 844 #endif 845 ); 846 } else 847 ssthresh = 0; 848 metrics.rmx_ssthresh = ssthresh; 849 850 metrics.rmx_rtt = tp->t_srtt; 851 metrics.rmx_rttvar = tp->t_rttvar; 852 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 853 metrics.rmx_bandwidth = tp->snd_bandwidth; 854 metrics.rmx_cwnd = tp->snd_cwnd; 855 metrics.rmx_sendpipe = 0; 856 metrics.rmx_recvpipe = 0; 857 858 tcp_hc_update(&inp->inp_inc, &metrics); 859 } 860 861 /* free the reassembly queue, if any */ 862 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 863 LIST_REMOVE(q, tqe_q); 864 m_freem(q->tqe_m); 865 uma_zfree(V_tcp_reass_zone, q); 866 tp->t_segqlen--; 867 V_tcp_reass_qsize--; 868 } 869 /* Disconnect offload device, if any. */ 870 tcp_offload_detach(tp); 871 872 tcp_free_sackholes(tp); 873 inp->inp_ppcb = NULL; 874 tp->t_inpcb = NULL; 875 uma_zfree(V_tcpcb_zone, tp); 876 } 877 878 /* 879 * Attempt to close a TCP control block, marking it as dropped, and freeing 880 * the socket if we hold the only reference. 881 */ 882 struct tcpcb * 883 tcp_close(struct tcpcb *tp) 884 { 885 struct inpcb *inp = tp->t_inpcb; 886 struct socket *so; 887 888 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 889 INP_WLOCK_ASSERT(inp); 890 891 /* Notify any offload devices of listener close */ 892 if (tp->t_state == TCPS_LISTEN) 893 tcp_offload_listen_close(tp); 894 in_pcbdrop(inp); 895 TCPSTAT_INC(tcps_closed); 896 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 897 so = inp->inp_socket; 898 soisdisconnected(so); 899 if (inp->inp_flags & INP_SOCKREF) { 900 KASSERT(so->so_state & SS_PROTOREF, 901 ("tcp_close: !SS_PROTOREF")); 902 inp->inp_flags &= ~INP_SOCKREF; 903 INP_WUNLOCK(inp); 904 ACCEPT_LOCK(); 905 SOCK_LOCK(so); 906 so->so_state &= ~SS_PROTOREF; 907 sofree(so); 908 return (NULL); 909 } 910 return (tp); 911 } 912 913 void 914 tcp_drain(void) 915 { 916 VNET_ITERATOR_DECL(vnet_iter); 917 918 if (!do_tcpdrain) 919 return; 920 921 VNET_LIST_RLOCK_NOSLEEP(); 922 VNET_FOREACH(vnet_iter) { 923 CURVNET_SET(vnet_iter); 924 struct inpcb *inpb; 925 struct tcpcb *tcpb; 926 struct tseg_qent *te; 927 928 /* 929 * Walk the tcpbs, if existing, and flush the reassembly queue, 930 * if there is one... 931 * XXX: The "Net/3" implementation doesn't imply that the TCP 932 * reassembly queue should be flushed, but in a situation 933 * where we're really low on mbufs, this is potentially 934 * usefull. 935 */ 936 INP_INFO_RLOCK(&V_tcbinfo); 937 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 938 if (inpb->inp_flags & INP_TIMEWAIT) 939 continue; 940 INP_WLOCK(inpb); 941 if ((tcpb = intotcpcb(inpb)) != NULL) { 942 while ((te = LIST_FIRST(&tcpb->t_segq)) 943 != NULL) { 944 LIST_REMOVE(te, tqe_q); 945 m_freem(te->tqe_m); 946 uma_zfree(V_tcp_reass_zone, te); 947 tcpb->t_segqlen--; 948 V_tcp_reass_qsize--; 949 } 950 tcp_clean_sackreport(tcpb); 951 } 952 INP_WUNLOCK(inpb); 953 } 954 INP_INFO_RUNLOCK(&V_tcbinfo); 955 CURVNET_RESTORE(); 956 } 957 VNET_LIST_RUNLOCK_NOSLEEP(); 958 } 959 960 /* 961 * Notify a tcp user of an asynchronous error; 962 * store error as soft error, but wake up user 963 * (for now, won't do anything until can select for soft error). 964 * 965 * Do not wake up user since there currently is no mechanism for 966 * reporting soft errors (yet - a kqueue filter may be added). 967 */ 968 static struct inpcb * 969 tcp_notify(struct inpcb *inp, int error) 970 { 971 struct tcpcb *tp; 972 973 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 974 INP_WLOCK_ASSERT(inp); 975 976 if ((inp->inp_flags & INP_TIMEWAIT) || 977 (inp->inp_flags & INP_DROPPED)) 978 return (inp); 979 980 tp = intotcpcb(inp); 981 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 982 983 /* 984 * Ignore some errors if we are hooked up. 985 * If connection hasn't completed, has retransmitted several times, 986 * and receives a second error, give up now. This is better 987 * than waiting a long time to establish a connection that 988 * can never complete. 989 */ 990 if (tp->t_state == TCPS_ESTABLISHED && 991 (error == EHOSTUNREACH || error == ENETUNREACH || 992 error == EHOSTDOWN)) { 993 return (inp); 994 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 995 tp->t_softerror) { 996 tp = tcp_drop(tp, error); 997 if (tp != NULL) 998 return (inp); 999 else 1000 return (NULL); 1001 } else { 1002 tp->t_softerror = error; 1003 return (inp); 1004 } 1005 #if 0 1006 wakeup( &so->so_timeo); 1007 sorwakeup(so); 1008 sowwakeup(so); 1009 #endif 1010 } 1011 1012 static int 1013 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1014 { 1015 int error, i, m, n, pcb_count; 1016 struct inpcb *inp, **inp_list; 1017 inp_gen_t gencnt; 1018 struct xinpgen xig; 1019 1020 /* 1021 * The process of preparing the TCB list is too time-consuming and 1022 * resource-intensive to repeat twice on every request. 1023 */ 1024 if (req->oldptr == NULL) { 1025 m = syncache_pcbcount(); 1026 n = V_tcbinfo.ipi_count; 1027 n += imax((m + n) / 8, 10); 1028 req->oldidx = 2 * (sizeof xig) + 1029 (m + n) * sizeof(struct xtcpcb); 1030 return (0); 1031 } 1032 1033 if (req->newptr != NULL) 1034 return (EPERM); 1035 1036 /* 1037 * OK, now we're committed to doing something. 1038 */ 1039 INP_INFO_RLOCK(&V_tcbinfo); 1040 gencnt = V_tcbinfo.ipi_gencnt; 1041 n = V_tcbinfo.ipi_count; 1042 INP_INFO_RUNLOCK(&V_tcbinfo); 1043 1044 m = syncache_pcbcount(); 1045 1046 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1047 + (n + m) * sizeof(struct xtcpcb)); 1048 if (error != 0) 1049 return (error); 1050 1051 xig.xig_len = sizeof xig; 1052 xig.xig_count = n + m; 1053 xig.xig_gen = gencnt; 1054 xig.xig_sogen = so_gencnt; 1055 error = SYSCTL_OUT(req, &xig, sizeof xig); 1056 if (error) 1057 return (error); 1058 1059 error = syncache_pcblist(req, m, &pcb_count); 1060 if (error) 1061 return (error); 1062 1063 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1064 if (inp_list == NULL) 1065 return (ENOMEM); 1066 1067 INP_INFO_RLOCK(&V_tcbinfo); 1068 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1069 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1070 INP_WLOCK(inp); 1071 if (inp->inp_gencnt <= gencnt) { 1072 /* 1073 * XXX: This use of cr_cansee(), introduced with 1074 * TCP state changes, is not quite right, but for 1075 * now, better than nothing. 1076 */ 1077 if (inp->inp_flags & INP_TIMEWAIT) { 1078 if (intotw(inp) != NULL) 1079 error = cr_cansee(req->td->td_ucred, 1080 intotw(inp)->tw_cred); 1081 else 1082 error = EINVAL; /* Skip this inp. */ 1083 } else 1084 error = cr_canseeinpcb(req->td->td_ucred, inp); 1085 if (error == 0) { 1086 in_pcbref(inp); 1087 inp_list[i++] = inp; 1088 } 1089 } 1090 INP_WUNLOCK(inp); 1091 } 1092 INP_INFO_RUNLOCK(&V_tcbinfo); 1093 n = i; 1094 1095 error = 0; 1096 for (i = 0; i < n; i++) { 1097 inp = inp_list[i]; 1098 INP_RLOCK(inp); 1099 if (inp->inp_gencnt <= gencnt) { 1100 struct xtcpcb xt; 1101 void *inp_ppcb; 1102 1103 bzero(&xt, sizeof(xt)); 1104 xt.xt_len = sizeof xt; 1105 /* XXX should avoid extra copy */ 1106 bcopy(inp, &xt.xt_inp, sizeof *inp); 1107 inp_ppcb = inp->inp_ppcb; 1108 if (inp_ppcb == NULL) 1109 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1110 else if (inp->inp_flags & INP_TIMEWAIT) { 1111 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1112 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1113 } else { 1114 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1115 if (xt.xt_tp.t_timers) 1116 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1117 } 1118 if (inp->inp_socket != NULL) 1119 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1120 else { 1121 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1122 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1123 } 1124 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1125 INP_RUNLOCK(inp); 1126 error = SYSCTL_OUT(req, &xt, sizeof xt); 1127 } else 1128 INP_RUNLOCK(inp); 1129 } 1130 INP_INFO_WLOCK(&V_tcbinfo); 1131 for (i = 0; i < n; i++) { 1132 inp = inp_list[i]; 1133 INP_WLOCK(inp); 1134 if (!in_pcbrele(inp)) 1135 INP_WUNLOCK(inp); 1136 } 1137 INP_INFO_WUNLOCK(&V_tcbinfo); 1138 1139 if (!error) { 1140 /* 1141 * Give the user an updated idea of our state. 1142 * If the generation differs from what we told 1143 * her before, she knows that something happened 1144 * while we were processing this request, and it 1145 * might be necessary to retry. 1146 */ 1147 INP_INFO_RLOCK(&V_tcbinfo); 1148 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1149 xig.xig_sogen = so_gencnt; 1150 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1151 INP_INFO_RUNLOCK(&V_tcbinfo); 1152 error = SYSCTL_OUT(req, &xig, sizeof xig); 1153 } 1154 free(inp_list, M_TEMP); 1155 return (error); 1156 } 1157 1158 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1159 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1160 1161 static int 1162 tcp_getcred(SYSCTL_HANDLER_ARGS) 1163 { 1164 struct xucred xuc; 1165 struct sockaddr_in addrs[2]; 1166 struct inpcb *inp; 1167 int error; 1168 1169 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1170 if (error) 1171 return (error); 1172 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1173 if (error) 1174 return (error); 1175 INP_INFO_RLOCK(&V_tcbinfo); 1176 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1177 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1178 if (inp != NULL) { 1179 INP_RLOCK(inp); 1180 INP_INFO_RUNLOCK(&V_tcbinfo); 1181 if (inp->inp_socket == NULL) 1182 error = ENOENT; 1183 if (error == 0) 1184 error = cr_canseeinpcb(req->td->td_ucred, inp); 1185 if (error == 0) 1186 cru2x(inp->inp_cred, &xuc); 1187 INP_RUNLOCK(inp); 1188 } else { 1189 INP_INFO_RUNLOCK(&V_tcbinfo); 1190 error = ENOENT; 1191 } 1192 if (error == 0) 1193 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1194 return (error); 1195 } 1196 1197 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1198 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1199 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1200 1201 #ifdef INET6 1202 static int 1203 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1204 { 1205 struct xucred xuc; 1206 struct sockaddr_in6 addrs[2]; 1207 struct inpcb *inp; 1208 int error, mapped = 0; 1209 1210 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1211 if (error) 1212 return (error); 1213 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1214 if (error) 1215 return (error); 1216 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1217 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1218 return (error); 1219 } 1220 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1221 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1222 mapped = 1; 1223 else 1224 return (EINVAL); 1225 } 1226 1227 INP_INFO_RLOCK(&V_tcbinfo); 1228 if (mapped == 1) 1229 inp = in_pcblookup_hash(&V_tcbinfo, 1230 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1231 addrs[1].sin6_port, 1232 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1233 addrs[0].sin6_port, 1234 0, NULL); 1235 else 1236 inp = in6_pcblookup_hash(&V_tcbinfo, 1237 &addrs[1].sin6_addr, addrs[1].sin6_port, 1238 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1239 if (inp != NULL) { 1240 INP_RLOCK(inp); 1241 INP_INFO_RUNLOCK(&V_tcbinfo); 1242 if (inp->inp_socket == NULL) 1243 error = ENOENT; 1244 if (error == 0) 1245 error = cr_canseeinpcb(req->td->td_ucred, inp); 1246 if (error == 0) 1247 cru2x(inp->inp_cred, &xuc); 1248 INP_RUNLOCK(inp); 1249 } else { 1250 INP_INFO_RUNLOCK(&V_tcbinfo); 1251 error = ENOENT; 1252 } 1253 if (error == 0) 1254 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1255 return (error); 1256 } 1257 1258 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1259 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1260 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1261 #endif 1262 1263 1264 void 1265 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1266 { 1267 struct ip *ip = vip; 1268 struct tcphdr *th; 1269 struct in_addr faddr; 1270 struct inpcb *inp; 1271 struct tcpcb *tp; 1272 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1273 struct icmp *icp; 1274 struct in_conninfo inc; 1275 tcp_seq icmp_tcp_seq; 1276 int mtu; 1277 1278 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1279 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1280 return; 1281 1282 if (cmd == PRC_MSGSIZE) 1283 notify = tcp_mtudisc; 1284 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1285 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1286 notify = tcp_drop_syn_sent; 1287 /* 1288 * Redirects don't need to be handled up here. 1289 */ 1290 else if (PRC_IS_REDIRECT(cmd)) 1291 return; 1292 /* 1293 * Source quench is depreciated. 1294 */ 1295 else if (cmd == PRC_QUENCH) 1296 return; 1297 /* 1298 * Hostdead is ugly because it goes linearly through all PCBs. 1299 * XXX: We never get this from ICMP, otherwise it makes an 1300 * excellent DoS attack on machines with many connections. 1301 */ 1302 else if (cmd == PRC_HOSTDEAD) 1303 ip = NULL; 1304 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1305 return; 1306 if (ip != NULL) { 1307 icp = (struct icmp *)((caddr_t)ip 1308 - offsetof(struct icmp, icmp_ip)); 1309 th = (struct tcphdr *)((caddr_t)ip 1310 + (ip->ip_hl << 2)); 1311 INP_INFO_WLOCK(&V_tcbinfo); 1312 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1313 ip->ip_src, th->th_sport, 0, NULL); 1314 if (inp != NULL) { 1315 INP_WLOCK(inp); 1316 if (!(inp->inp_flags & INP_TIMEWAIT) && 1317 !(inp->inp_flags & INP_DROPPED) && 1318 !(inp->inp_socket == NULL)) { 1319 icmp_tcp_seq = htonl(th->th_seq); 1320 tp = intotcpcb(inp); 1321 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1322 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1323 if (cmd == PRC_MSGSIZE) { 1324 /* 1325 * MTU discovery: 1326 * If we got a needfrag set the MTU 1327 * in the route to the suggested new 1328 * value (if given) and then notify. 1329 */ 1330 bzero(&inc, sizeof(inc)); 1331 inc.inc_faddr = faddr; 1332 inc.inc_fibnum = 1333 inp->inp_inc.inc_fibnum; 1334 1335 mtu = ntohs(icp->icmp_nextmtu); 1336 /* 1337 * If no alternative MTU was 1338 * proposed, try the next smaller 1339 * one. ip->ip_len has already 1340 * been swapped in icmp_input(). 1341 */ 1342 if (!mtu) 1343 mtu = ip_next_mtu(ip->ip_len, 1344 1); 1345 if (mtu < V_tcp_minmss 1346 + sizeof(struct tcpiphdr)) 1347 mtu = V_tcp_minmss 1348 + sizeof(struct tcpiphdr); 1349 /* 1350 * Only cache the the MTU if it 1351 * is smaller than the interface 1352 * or route MTU. tcp_mtudisc() 1353 * will do right thing by itself. 1354 */ 1355 if (mtu <= tcp_maxmtu(&inc, NULL)) 1356 tcp_hc_updatemtu(&inc, mtu); 1357 } 1358 1359 inp = (*notify)(inp, inetctlerrmap[cmd]); 1360 } 1361 } 1362 if (inp != NULL) 1363 INP_WUNLOCK(inp); 1364 } else { 1365 bzero(&inc, sizeof(inc)); 1366 inc.inc_fport = th->th_dport; 1367 inc.inc_lport = th->th_sport; 1368 inc.inc_faddr = faddr; 1369 inc.inc_laddr = ip->ip_src; 1370 syncache_unreach(&inc, th); 1371 } 1372 INP_INFO_WUNLOCK(&V_tcbinfo); 1373 } else 1374 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1375 } 1376 1377 #ifdef INET6 1378 void 1379 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1380 { 1381 struct tcphdr th; 1382 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1383 struct ip6_hdr *ip6; 1384 struct mbuf *m; 1385 struct ip6ctlparam *ip6cp = NULL; 1386 const struct sockaddr_in6 *sa6_src = NULL; 1387 int off; 1388 struct tcp_portonly { 1389 u_int16_t th_sport; 1390 u_int16_t th_dport; 1391 } *thp; 1392 1393 if (sa->sa_family != AF_INET6 || 1394 sa->sa_len != sizeof(struct sockaddr_in6)) 1395 return; 1396 1397 if (cmd == PRC_MSGSIZE) 1398 notify = tcp_mtudisc; 1399 else if (!PRC_IS_REDIRECT(cmd) && 1400 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1401 return; 1402 /* Source quench is depreciated. */ 1403 else if (cmd == PRC_QUENCH) 1404 return; 1405 1406 /* if the parameter is from icmp6, decode it. */ 1407 if (d != NULL) { 1408 ip6cp = (struct ip6ctlparam *)d; 1409 m = ip6cp->ip6c_m; 1410 ip6 = ip6cp->ip6c_ip6; 1411 off = ip6cp->ip6c_off; 1412 sa6_src = ip6cp->ip6c_src; 1413 } else { 1414 m = NULL; 1415 ip6 = NULL; 1416 off = 0; /* fool gcc */ 1417 sa6_src = &sa6_any; 1418 } 1419 1420 if (ip6 != NULL) { 1421 struct in_conninfo inc; 1422 /* 1423 * XXX: We assume that when IPV6 is non NULL, 1424 * M and OFF are valid. 1425 */ 1426 1427 /* check if we can safely examine src and dst ports */ 1428 if (m->m_pkthdr.len < off + sizeof(*thp)) 1429 return; 1430 1431 bzero(&th, sizeof(th)); 1432 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1433 1434 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1435 (struct sockaddr *)ip6cp->ip6c_src, 1436 th.th_sport, cmd, NULL, notify); 1437 1438 bzero(&inc, sizeof(inc)); 1439 inc.inc_fport = th.th_dport; 1440 inc.inc_lport = th.th_sport; 1441 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1442 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1443 inc.inc_flags |= INC_ISIPV6; 1444 INP_INFO_WLOCK(&V_tcbinfo); 1445 syncache_unreach(&inc, &th); 1446 INP_INFO_WUNLOCK(&V_tcbinfo); 1447 } else 1448 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1449 0, cmd, NULL, notify); 1450 } 1451 #endif /* INET6 */ 1452 1453 1454 /* 1455 * Following is where TCP initial sequence number generation occurs. 1456 * 1457 * There are two places where we must use initial sequence numbers: 1458 * 1. In SYN-ACK packets. 1459 * 2. In SYN packets. 1460 * 1461 * All ISNs for SYN-ACK packets are generated by the syncache. See 1462 * tcp_syncache.c for details. 1463 * 1464 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1465 * depends on this property. In addition, these ISNs should be 1466 * unguessable so as to prevent connection hijacking. To satisfy 1467 * the requirements of this situation, the algorithm outlined in 1468 * RFC 1948 is used, with only small modifications. 1469 * 1470 * Implementation details: 1471 * 1472 * Time is based off the system timer, and is corrected so that it 1473 * increases by one megabyte per second. This allows for proper 1474 * recycling on high speed LANs while still leaving over an hour 1475 * before rollover. 1476 * 1477 * As reading the *exact* system time is too expensive to be done 1478 * whenever setting up a TCP connection, we increment the time 1479 * offset in two ways. First, a small random positive increment 1480 * is added to isn_offset for each connection that is set up. 1481 * Second, the function tcp_isn_tick fires once per clock tick 1482 * and increments isn_offset as necessary so that sequence numbers 1483 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1484 * random positive increments serve only to ensure that the same 1485 * exact sequence number is never sent out twice (as could otherwise 1486 * happen when a port is recycled in less than the system tick 1487 * interval.) 1488 * 1489 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1490 * between seeding of isn_secret. This is normally set to zero, 1491 * as reseeding should not be necessary. 1492 * 1493 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1494 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1495 * general, this means holding an exclusive (write) lock. 1496 */ 1497 1498 #define ISN_BYTES_PER_SECOND 1048576 1499 #define ISN_STATIC_INCREMENT 4096 1500 #define ISN_RANDOM_INCREMENT (4096 - 1) 1501 1502 static VNET_DEFINE(u_char, isn_secret[32]); 1503 static VNET_DEFINE(int, isn_last_reseed); 1504 static VNET_DEFINE(u_int32_t, isn_offset); 1505 static VNET_DEFINE(u_int32_t, isn_offset_old); 1506 1507 #define V_isn_secret VNET(isn_secret) 1508 #define V_isn_last_reseed VNET(isn_last_reseed) 1509 #define V_isn_offset VNET(isn_offset) 1510 #define V_isn_offset_old VNET(isn_offset_old) 1511 1512 tcp_seq 1513 tcp_new_isn(struct tcpcb *tp) 1514 { 1515 MD5_CTX isn_ctx; 1516 u_int32_t md5_buffer[4]; 1517 tcp_seq new_isn; 1518 1519 INP_WLOCK_ASSERT(tp->t_inpcb); 1520 1521 ISN_LOCK(); 1522 /* Seed if this is the first use, reseed if requested. */ 1523 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1524 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1525 < (u_int)ticks))) { 1526 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1527 V_isn_last_reseed = ticks; 1528 } 1529 1530 /* Compute the md5 hash and return the ISN. */ 1531 MD5Init(&isn_ctx); 1532 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1533 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1534 #ifdef INET6 1535 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1536 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1537 sizeof(struct in6_addr)); 1538 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1539 sizeof(struct in6_addr)); 1540 } else 1541 #endif 1542 { 1543 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1544 sizeof(struct in_addr)); 1545 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1546 sizeof(struct in_addr)); 1547 } 1548 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1549 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1550 new_isn = (tcp_seq) md5_buffer[0]; 1551 V_isn_offset += ISN_STATIC_INCREMENT + 1552 (arc4random() & ISN_RANDOM_INCREMENT); 1553 new_isn += V_isn_offset; 1554 ISN_UNLOCK(); 1555 return (new_isn); 1556 } 1557 1558 /* 1559 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1560 * to keep time flowing at a relatively constant rate. If the random 1561 * increments have already pushed us past the projected offset, do nothing. 1562 */ 1563 static void 1564 tcp_isn_tick(void *xtp) 1565 { 1566 VNET_ITERATOR_DECL(vnet_iter); 1567 u_int32_t projected_offset; 1568 1569 VNET_LIST_RLOCK_NOSLEEP(); 1570 ISN_LOCK(); 1571 VNET_FOREACH(vnet_iter) { 1572 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 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_NOSLEEP(); 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 struct tcpcb *tp; 1596 1597 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1598 INP_WLOCK_ASSERT(inp); 1599 1600 if ((inp->inp_flags & INP_TIMEWAIT) || 1601 (inp->inp_flags & INP_DROPPED)) 1602 return (inp); 1603 1604 tp = intotcpcb(inp); 1605 if (tp->t_state != TCPS_SYN_SENT) 1606 return (inp); 1607 1608 tp = tcp_drop(tp, errno); 1609 if (tp != NULL) 1610 return (inp); 1611 else 1612 return (NULL); 1613 } 1614 1615 /* 1616 * When `need fragmentation' ICMP is received, update our idea of the MSS 1617 * based on the new value in the route. Also nudge TCP to send something, 1618 * since we know the packet we just sent was dropped. 1619 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1620 */ 1621 struct inpcb * 1622 tcp_mtudisc(struct inpcb *inp, int errno) 1623 { 1624 struct tcpcb *tp; 1625 struct socket *so; 1626 1627 INP_WLOCK_ASSERT(inp); 1628 if ((inp->inp_flags & INP_TIMEWAIT) || 1629 (inp->inp_flags & INP_DROPPED)) 1630 return (inp); 1631 1632 tp = intotcpcb(inp); 1633 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1634 1635 tcp_mss_update(tp, -1, NULL, NULL); 1636 1637 so = inp->inp_socket; 1638 SOCKBUF_LOCK(&so->so_snd); 1639 /* If the mss is larger than the socket buffer, decrease the mss. */ 1640 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1641 tp->t_maxseg = so->so_snd.sb_hiwat; 1642 SOCKBUF_UNLOCK(&so->so_snd); 1643 1644 TCPSTAT_INC(tcps_mturesent); 1645 tp->t_rtttime = 0; 1646 tp->snd_nxt = tp->snd_una; 1647 tcp_free_sackholes(tp); 1648 tp->snd_recover = tp->snd_max; 1649 if (tp->t_flags & TF_SACK_PERMIT) 1650 EXIT_FASTRECOVERY(tp); 1651 tcp_output_send(tp); 1652 return (inp); 1653 } 1654 1655 /* 1656 * Look-up the routing entry to the peer of this inpcb. If no route 1657 * is found and it cannot be allocated, then return 0. This routine 1658 * is called by TCP routines that access the rmx structure and by 1659 * tcp_mss_update to get the peer/interface MTU. 1660 */ 1661 u_long 1662 tcp_maxmtu(struct in_conninfo *inc, int *flags) 1663 { 1664 struct route sro; 1665 struct sockaddr_in *dst; 1666 struct ifnet *ifp; 1667 u_long maxmtu = 0; 1668 1669 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1670 1671 bzero(&sro, sizeof(sro)); 1672 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1673 dst = (struct sockaddr_in *)&sro.ro_dst; 1674 dst->sin_family = AF_INET; 1675 dst->sin_len = sizeof(*dst); 1676 dst->sin_addr = inc->inc_faddr; 1677 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1678 } 1679 if (sro.ro_rt != NULL) { 1680 ifp = sro.ro_rt->rt_ifp; 1681 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1682 maxmtu = ifp->if_mtu; 1683 else 1684 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1685 1686 /* Report additional interface capabilities. */ 1687 if (flags != NULL) { 1688 if (ifp->if_capenable & IFCAP_TSO4 && 1689 ifp->if_hwassist & CSUM_TSO) 1690 *flags |= CSUM_TSO; 1691 } 1692 RTFREE(sro.ro_rt); 1693 } 1694 return (maxmtu); 1695 } 1696 1697 #ifdef INET6 1698 u_long 1699 tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1700 { 1701 struct route_in6 sro6; 1702 struct ifnet *ifp; 1703 u_long maxmtu = 0; 1704 1705 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1706 1707 bzero(&sro6, sizeof(sro6)); 1708 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1709 sro6.ro_dst.sin6_family = AF_INET6; 1710 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1711 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1712 rtalloc_ign((struct route *)&sro6, 0); 1713 } 1714 if (sro6.ro_rt != NULL) { 1715 ifp = sro6.ro_rt->rt_ifp; 1716 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1717 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1718 else 1719 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1720 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1721 1722 /* Report additional interface capabilities. */ 1723 if (flags != NULL) { 1724 if (ifp->if_capenable & IFCAP_TSO6 && 1725 ifp->if_hwassist & CSUM_TSO) 1726 *flags |= CSUM_TSO; 1727 } 1728 RTFREE(sro6.ro_rt); 1729 } 1730 1731 return (maxmtu); 1732 } 1733 #endif /* INET6 */ 1734 1735 #ifdef IPSEC 1736 /* compute ESP/AH header size for TCP, including outer IP header. */ 1737 size_t 1738 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1739 { 1740 struct inpcb *inp; 1741 struct mbuf *m; 1742 size_t hdrsiz; 1743 struct ip *ip; 1744 #ifdef INET6 1745 struct ip6_hdr *ip6; 1746 #endif 1747 struct tcphdr *th; 1748 1749 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1750 return (0); 1751 MGETHDR(m, M_DONTWAIT, MT_DATA); 1752 if (!m) 1753 return (0); 1754 1755 #ifdef INET6 1756 if ((inp->inp_vflag & INP_IPV6) != 0) { 1757 ip6 = mtod(m, struct ip6_hdr *); 1758 th = (struct tcphdr *)(ip6 + 1); 1759 m->m_pkthdr.len = m->m_len = 1760 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1761 tcpip_fillheaders(inp, ip6, th); 1762 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1763 } else 1764 #endif /* INET6 */ 1765 { 1766 ip = mtod(m, struct ip *); 1767 th = (struct tcphdr *)(ip + 1); 1768 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1769 tcpip_fillheaders(inp, ip, th); 1770 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1771 } 1772 1773 m_free(m); 1774 return (hdrsiz); 1775 } 1776 #endif /* IPSEC */ 1777 1778 /* 1779 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1780 * 1781 * This code attempts to calculate the bandwidth-delay product as a 1782 * means of determining the optimal window size to maximize bandwidth, 1783 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1784 * routers. This code also does a fairly good job keeping RTTs in check 1785 * across slow links like modems. We implement an algorithm which is very 1786 * similar (but not meant to be) TCP/Vegas. The code operates on the 1787 * transmitter side of a TCP connection and so only effects the transmit 1788 * side of the connection. 1789 * 1790 * BACKGROUND: TCP makes no provision for the management of buffer space 1791 * at the end points or at the intermediate routers and switches. A TCP 1792 * stream, whether using NewReno or not, will eventually buffer as 1793 * many packets as it is able and the only reason this typically works is 1794 * due to the fairly small default buffers made available for a connection 1795 * (typicaly 16K or 32K). As machines use larger windows and/or window 1796 * scaling it is now fairly easy for even a single TCP connection to blow-out 1797 * all available buffer space not only on the local interface, but on 1798 * intermediate routers and switches as well. NewReno makes a misguided 1799 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1800 * then backing off, then steadily increasing the window again until another 1801 * failure occurs, ad-infinitum. This results in terrible oscillation that 1802 * is only made worse as network loads increase and the idea of intentionally 1803 * blowing out network buffers is, frankly, a terrible way to manage network 1804 * resources. 1805 * 1806 * It is far better to limit the transmit window prior to the failure 1807 * condition being achieved. There are two general ways to do this: First 1808 * you can 'scan' through different transmit window sizes and locate the 1809 * point where the RTT stops increasing, indicating that you have filled the 1810 * pipe, then scan backwards until you note that RTT stops decreasing, then 1811 * repeat ad-infinitum. This method works in principle but has severe 1812 * implementation issues due to RTT variances, timer granularity, and 1813 * instability in the algorithm which can lead to many false positives and 1814 * create oscillations as well as interact badly with other TCP streams 1815 * implementing the same algorithm. 1816 * 1817 * The second method is to limit the window to the bandwidth delay product 1818 * of the link. This is the method we implement. RTT variances and our 1819 * own manipulation of the congestion window, bwnd, can potentially 1820 * destabilize the algorithm. For this reason we have to stabilize the 1821 * elements used to calculate the window. We do this by using the minimum 1822 * observed RTT, the long term average of the observed bandwidth, and 1823 * by adding two segments worth of slop. It isn't perfect but it is able 1824 * to react to changing conditions and gives us a very stable basis on 1825 * which to extend the algorithm. 1826 */ 1827 void 1828 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1829 { 1830 u_long bw; 1831 u_long bwnd; 1832 int save_ticks; 1833 1834 INP_WLOCK_ASSERT(tp->t_inpcb); 1835 1836 /* 1837 * If inflight_enable is disabled in the middle of a tcp connection, 1838 * make sure snd_bwnd is effectively disabled. 1839 */ 1840 if (V_tcp_inflight_enable == 0 || 1841 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1842 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1843 tp->snd_bandwidth = 0; 1844 return; 1845 } 1846 1847 /* 1848 * Figure out the bandwidth. Due to the tick granularity this 1849 * is a very rough number and it MUST be averaged over a fairly 1850 * long period of time. XXX we need to take into account a link 1851 * that is not using all available bandwidth, but for now our 1852 * slop will ramp us up if this case occurs and the bandwidth later 1853 * increases. 1854 * 1855 * Note: if ticks rollover 'bw' may wind up negative. We must 1856 * effectively reset t_bw_rtttime for this case. 1857 */ 1858 save_ticks = ticks; 1859 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1860 return; 1861 1862 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1863 (save_ticks - tp->t_bw_rtttime); 1864 tp->t_bw_rtttime = save_ticks; 1865 tp->t_bw_rtseq = ack_seq; 1866 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1867 return; 1868 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1869 1870 tp->snd_bandwidth = bw; 1871 1872 /* 1873 * Calculate the semi-static bandwidth delay product, plus two maximal 1874 * segments. The additional slop puts us squarely in the sweet 1875 * spot and also handles the bandwidth run-up case and stabilization. 1876 * Without the slop we could be locking ourselves into a lower 1877 * bandwidth. 1878 * 1879 * Situations Handled: 1880 * (1) Prevents over-queueing of packets on LANs, especially on 1881 * high speed LANs, allowing larger TCP buffers to be 1882 * specified, and also does a good job preventing 1883 * over-queueing of packets over choke points like modems 1884 * (at least for the transmit side). 1885 * 1886 * (2) Is able to handle changing network loads (bandwidth 1887 * drops so bwnd drops, bandwidth increases so bwnd 1888 * increases). 1889 * 1890 * (3) Theoretically should stabilize in the face of multiple 1891 * connections implementing the same algorithm (this may need 1892 * a little work). 1893 * 1894 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1895 * be adjusted with a sysctl but typically only needs to be 1896 * on very slow connections. A value no smaller then 5 1897 * should be used, but only reduce this default if you have 1898 * no other choice. 1899 */ 1900 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1901 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1902 #undef USERTT 1903 1904 if (tcp_inflight_debug > 0) { 1905 static int ltime; 1906 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1907 ltime = ticks; 1908 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1909 tp, 1910 bw, 1911 tp->t_rttbest, 1912 tp->t_srtt, 1913 bwnd 1914 ); 1915 } 1916 } 1917 if ((long)bwnd < V_tcp_inflight_min) 1918 bwnd = V_tcp_inflight_min; 1919 if (bwnd > V_tcp_inflight_max) 1920 bwnd = V_tcp_inflight_max; 1921 if ((long)bwnd < tp->t_maxseg * 2) 1922 bwnd = tp->t_maxseg * 2; 1923 tp->snd_bwnd = bwnd; 1924 } 1925 1926 #ifdef TCP_SIGNATURE 1927 /* 1928 * Callback function invoked by m_apply() to digest TCP segment data 1929 * contained within an mbuf chain. 1930 */ 1931 static int 1932 tcp_signature_apply(void *fstate, void *data, u_int len) 1933 { 1934 1935 MD5Update(fstate, (u_char *)data, len); 1936 return (0); 1937 } 1938 1939 /* 1940 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1941 * 1942 * Parameters: 1943 * m pointer to head of mbuf chain 1944 * _unused 1945 * len length of TCP segment data, excluding options 1946 * optlen length of TCP segment options 1947 * buf pointer to storage for computed MD5 digest 1948 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1949 * 1950 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1951 * When called from tcp_input(), we can be sure that th_sum has been 1952 * zeroed out and verified already. 1953 * 1954 * Return 0 if successful, otherwise return -1. 1955 * 1956 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1957 * search with the destination IP address, and a 'magic SPI' to be 1958 * determined by the application. This is hardcoded elsewhere to 1179 1959 * right now. Another branch of this code exists which uses the SPD to 1960 * specify per-application flows but it is unstable. 1961 */ 1962 int 1963 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1964 u_char *buf, u_int direction) 1965 { 1966 union sockaddr_union dst; 1967 struct ippseudo ippseudo; 1968 MD5_CTX ctx; 1969 int doff; 1970 struct ip *ip; 1971 struct ipovly *ipovly; 1972 struct secasvar *sav; 1973 struct tcphdr *th; 1974 #ifdef INET6 1975 struct ip6_hdr *ip6; 1976 struct in6_addr in6; 1977 char ip6buf[INET6_ADDRSTRLEN]; 1978 uint32_t plen; 1979 uint16_t nhdr; 1980 #endif 1981 u_short savecsum; 1982 1983 KASSERT(m != NULL, ("NULL mbuf chain")); 1984 KASSERT(buf != NULL, ("NULL signature pointer")); 1985 1986 /* Extract the destination from the IP header in the mbuf. */ 1987 bzero(&dst, sizeof(union sockaddr_union)); 1988 ip = mtod(m, struct ip *); 1989 #ifdef INET6 1990 ip6 = NULL; /* Make the compiler happy. */ 1991 #endif 1992 switch (ip->ip_v) { 1993 case IPVERSION: 1994 dst.sa.sa_len = sizeof(struct sockaddr_in); 1995 dst.sa.sa_family = AF_INET; 1996 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 1997 ip->ip_src : ip->ip_dst; 1998 break; 1999 #ifdef INET6 2000 case (IPV6_VERSION >> 4): 2001 ip6 = mtod(m, struct ip6_hdr *); 2002 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2003 dst.sa.sa_family = AF_INET6; 2004 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2005 ip6->ip6_src : ip6->ip6_dst; 2006 break; 2007 #endif 2008 default: 2009 return (EINVAL); 2010 /* NOTREACHED */ 2011 break; 2012 } 2013 2014 /* Look up an SADB entry which matches the address of the peer. */ 2015 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2016 if (sav == NULL) { 2017 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2018 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2019 #ifdef INET6 2020 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2021 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2022 #endif 2023 "(unsupported)")); 2024 return (EINVAL); 2025 } 2026 2027 MD5Init(&ctx); 2028 /* 2029 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2030 * 2031 * XXX The ippseudo header MUST be digested in network byte order, 2032 * or else we'll fail the regression test. Assume all fields we've 2033 * been doing arithmetic on have been in host byte order. 2034 * XXX One cannot depend on ipovly->ih_len here. When called from 2035 * tcp_output(), the underlying ip_len member has not yet been set. 2036 */ 2037 switch (ip->ip_v) { 2038 case IPVERSION: 2039 ipovly = (struct ipovly *)ip; 2040 ippseudo.ippseudo_src = ipovly->ih_src; 2041 ippseudo.ippseudo_dst = ipovly->ih_dst; 2042 ippseudo.ippseudo_pad = 0; 2043 ippseudo.ippseudo_p = IPPROTO_TCP; 2044 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2045 optlen); 2046 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2047 2048 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2049 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2050 break; 2051 #ifdef INET6 2052 /* 2053 * RFC 2385, 2.0 Proposal 2054 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2055 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2056 * extended next header value (to form 32 bits), and 32-bit segment 2057 * length. 2058 * Note: Upper-Layer Packet Length comes before Next Header. 2059 */ 2060 case (IPV6_VERSION >> 4): 2061 in6 = ip6->ip6_src; 2062 in6_clearscope(&in6); 2063 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2064 in6 = ip6->ip6_dst; 2065 in6_clearscope(&in6); 2066 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2067 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2068 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2069 nhdr = 0; 2070 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2071 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2072 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2073 nhdr = IPPROTO_TCP; 2074 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2075 2076 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2077 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2078 break; 2079 #endif 2080 default: 2081 return (EINVAL); 2082 /* NOTREACHED */ 2083 break; 2084 } 2085 2086 2087 /* 2088 * Step 2: Update MD5 hash with TCP header, excluding options. 2089 * The TCP checksum must be set to zero. 2090 */ 2091 savecsum = th->th_sum; 2092 th->th_sum = 0; 2093 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2094 th->th_sum = savecsum; 2095 2096 /* 2097 * Step 3: Update MD5 hash with TCP segment data. 2098 * Use m_apply() to avoid an early m_pullup(). 2099 */ 2100 if (len > 0) 2101 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2102 2103 /* 2104 * Step 4: Update MD5 hash with shared secret. 2105 */ 2106 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2107 MD5Final(buf, &ctx); 2108 2109 key_sa_recordxfer(sav, m); 2110 KEY_FREESAV(&sav); 2111 return (0); 2112 } 2113 #endif /* TCP_SIGNATURE */ 2114 2115 static int 2116 sysctl_drop(SYSCTL_HANDLER_ARGS) 2117 { 2118 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2119 struct sockaddr_storage addrs[2]; 2120 struct inpcb *inp; 2121 struct tcpcb *tp; 2122 struct tcptw *tw; 2123 struct sockaddr_in *fin, *lin; 2124 #ifdef INET6 2125 struct sockaddr_in6 *fin6, *lin6; 2126 #endif 2127 int error; 2128 2129 inp = NULL; 2130 fin = lin = NULL; 2131 #ifdef INET6 2132 fin6 = lin6 = NULL; 2133 #endif 2134 error = 0; 2135 2136 if (req->oldptr != NULL || req->oldlen != 0) 2137 return (EINVAL); 2138 if (req->newptr == NULL) 2139 return (EPERM); 2140 if (req->newlen < sizeof(addrs)) 2141 return (ENOMEM); 2142 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2143 if (error) 2144 return (error); 2145 2146 switch (addrs[0].ss_family) { 2147 #ifdef INET6 2148 case AF_INET6: 2149 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2150 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2151 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2152 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2153 return (EINVAL); 2154 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2155 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2156 return (EINVAL); 2157 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2158 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2159 fin = (struct sockaddr_in *)&addrs[0]; 2160 lin = (struct sockaddr_in *)&addrs[1]; 2161 break; 2162 } 2163 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2164 if (error) 2165 return (error); 2166 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2167 if (error) 2168 return (error); 2169 break; 2170 #endif 2171 case AF_INET: 2172 fin = (struct sockaddr_in *)&addrs[0]; 2173 lin = (struct sockaddr_in *)&addrs[1]; 2174 if (fin->sin_len != sizeof(struct sockaddr_in) || 2175 lin->sin_len != sizeof(struct sockaddr_in)) 2176 return (EINVAL); 2177 break; 2178 default: 2179 return (EINVAL); 2180 } 2181 INP_INFO_WLOCK(&V_tcbinfo); 2182 switch (addrs[0].ss_family) { 2183 #ifdef INET6 2184 case AF_INET6: 2185 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2186 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2187 NULL); 2188 break; 2189 #endif 2190 case AF_INET: 2191 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2192 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2193 break; 2194 } 2195 if (inp != NULL) { 2196 INP_WLOCK(inp); 2197 if (inp->inp_flags & INP_TIMEWAIT) { 2198 /* 2199 * XXXRW: There currently exists a state where an 2200 * inpcb is present, but its timewait state has been 2201 * discarded. For now, don't allow dropping of this 2202 * type of inpcb. 2203 */ 2204 tw = intotw(inp); 2205 if (tw != NULL) 2206 tcp_twclose(tw, 0); 2207 else 2208 INP_WUNLOCK(inp); 2209 } else if (!(inp->inp_flags & INP_DROPPED) && 2210 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2211 tp = intotcpcb(inp); 2212 tp = tcp_drop(tp, ECONNABORTED); 2213 if (tp != NULL) 2214 INP_WUNLOCK(inp); 2215 } else 2216 INP_WUNLOCK(inp); 2217 } else 2218 error = ESRCH; 2219 INP_INFO_WUNLOCK(&V_tcbinfo); 2220 return (error); 2221 } 2222 2223 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2224 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2225 0, sysctl_drop, "", "Drop TCP connection"); 2226 2227 /* 2228 * Generate a standardized TCP log line for use throughout the 2229 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2230 * allow use in the interrupt context. 2231 * 2232 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2233 * NB: The function may return NULL if memory allocation failed. 2234 * 2235 * Due to header inclusion and ordering limitations the struct ip 2236 * and ip6_hdr pointers have to be passed as void pointers. 2237 */ 2238 char * 2239 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2240 const void *ip6hdr) 2241 { 2242 2243 /* Is logging enabled? */ 2244 if (tcp_log_in_vain == 0) 2245 return (NULL); 2246 2247 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2248 } 2249 2250 char * 2251 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2252 const void *ip6hdr) 2253 { 2254 2255 /* Is logging enabled? */ 2256 if (tcp_log_debug == 0) 2257 return (NULL); 2258 2259 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2260 } 2261 2262 static char * 2263 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2264 const void *ip6hdr) 2265 { 2266 char *s, *sp; 2267 size_t size; 2268 struct ip *ip; 2269 #ifdef INET6 2270 const struct ip6_hdr *ip6; 2271 2272 ip6 = (const struct ip6_hdr *)ip6hdr; 2273 #endif /* INET6 */ 2274 ip = (struct ip *)ip4hdr; 2275 2276 /* 2277 * The log line looks like this: 2278 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2279 */ 2280 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2281 sizeof(PRINT_TH_FLAGS) + 1 + 2282 #ifdef INET6 2283 2 * INET6_ADDRSTRLEN; 2284 #else 2285 2 * INET_ADDRSTRLEN; 2286 #endif /* INET6 */ 2287 2288 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2289 if (s == NULL) 2290 return (NULL); 2291 2292 strcat(s, "TCP: ["); 2293 sp = s + strlen(s); 2294 2295 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2296 inet_ntoa_r(inc->inc_faddr, sp); 2297 sp = s + strlen(s); 2298 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2299 sp = s + strlen(s); 2300 inet_ntoa_r(inc->inc_laddr, sp); 2301 sp = s + strlen(s); 2302 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2303 #ifdef INET6 2304 } else if (inc) { 2305 ip6_sprintf(sp, &inc->inc6_faddr); 2306 sp = s + strlen(s); 2307 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2308 sp = s + strlen(s); 2309 ip6_sprintf(sp, &inc->inc6_laddr); 2310 sp = s + strlen(s); 2311 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2312 } else if (ip6 && th) { 2313 ip6_sprintf(sp, &ip6->ip6_src); 2314 sp = s + strlen(s); 2315 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2316 sp = s + strlen(s); 2317 ip6_sprintf(sp, &ip6->ip6_dst); 2318 sp = s + strlen(s); 2319 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2320 #endif /* INET6 */ 2321 } else if (ip && th) { 2322 inet_ntoa_r(ip->ip_src, sp); 2323 sp = s + strlen(s); 2324 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2325 sp = s + strlen(s); 2326 inet_ntoa_r(ip->ip_dst, sp); 2327 sp = s + strlen(s); 2328 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2329 } else { 2330 free(s, M_TCPLOG); 2331 return (NULL); 2332 } 2333 sp = s + strlen(s); 2334 if (th) 2335 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2336 if (*(s + size - 1) != '\0') 2337 panic("%s: string too long", __func__); 2338 return (s); 2339 } 2340