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); 115 #ifdef INET6 116 VNET_DEFINE(int, tcp_v6mssdflt); 117 #endif 118 VNET_DEFINE(int, tcp_minmss); 119 VNET_DEFINE(int, tcp_do_rfc1323); 120 121 static VNET_DEFINE(int, icmp_may_rst); 122 static VNET_DEFINE(int, tcp_isn_reseed_interval); 123 static VNET_DEFINE(int, tcp_inflight_enable); 124 static VNET_DEFINE(int, tcp_inflight_rttthresh); 125 static VNET_DEFINE(int, tcp_inflight_min); 126 static VNET_DEFINE(int, tcp_inflight_max); 127 static VNET_DEFINE(int, tcp_inflight_stab); 128 129 #define V_icmp_may_rst VNET(icmp_may_rst) 130 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 131 #define V_tcp_inflight_enable VNET(tcp_inflight_enable) 132 #define V_tcp_inflight_rttthresh VNET(tcp_inflight_rttthresh) 133 #define V_tcp_inflight_min VNET(tcp_inflight_min) 134 #define V_tcp_inflight_max VNET(tcp_inflight_max) 135 #define V_tcp_inflight_stab VNET(tcp_inflight_stab) 136 137 static int 138 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 139 { 140 int error, new; 141 142 new = V_tcp_mssdflt; 143 error = sysctl_handle_int(oidp, &new, 0, req); 144 if (error == 0 && req->newptr) { 145 if (new < TCP_MINMSS) 146 error = EINVAL; 147 else 148 V_tcp_mssdflt = new; 149 } 150 return (error); 151 } 152 153 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 154 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 155 &sysctl_net_inet_tcp_mss_check, "I", 156 "Default TCP Maximum Segment Size"); 157 158 #ifdef INET6 159 static int 160 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 161 { 162 int error, new; 163 164 new = V_tcp_v6mssdflt; 165 error = sysctl_handle_int(oidp, &new, 0, req); 166 if (error == 0 && req->newptr) { 167 if (new < TCP_MINMSS) 168 error = EINVAL; 169 else 170 V_tcp_v6mssdflt = new; 171 } 172 return (error); 173 } 174 175 SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 176 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 177 &sysctl_net_inet_tcp_mss_v6_check, "I", 178 "Default TCP Maximum Segment Size for IPv6"); 179 #endif 180 181 static int 182 vnet_sysctl_msec_to_ticks(SYSCTL_HANDLER_ARGS) 183 { 184 185 VNET_SYSCTL_ARG(req, arg1); 186 return (sysctl_msec_to_ticks(oidp, arg1, arg2, req)); 187 } 188 189 /* 190 * Minimum MSS we accept and use. This prevents DoS attacks where 191 * we are forced to a ridiculous low MSS like 20 and send hundreds 192 * of packets instead of one. The effect scales with the available 193 * bandwidth and quickly saturates the CPU and network interface 194 * with packet generation and sending. Set to zero to disable MINMSS 195 * checking. This setting prevents us from sending too small packets. 196 */ 197 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 198 &VNET_NAME(tcp_minmss), 0, 199 "Minmum TCP Maximum Segment Size"); 200 201 SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 202 &VNET_NAME(tcp_do_rfc1323), 0, 203 "Enable rfc1323 (high performance TCP) extensions"); 204 205 static int tcp_log_debug = 0; 206 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 207 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 208 209 static int tcp_tcbhashsize = 0; 210 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 211 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 212 213 static int do_tcpdrain = 1; 214 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 215 "Enable tcp_drain routine for extra help when low on mbufs"); 216 217 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 218 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 219 220 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, 221 &VNET_NAME(icmp_may_rst), 0, 222 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 223 224 SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 225 &VNET_NAME(tcp_isn_reseed_interval), 0, 226 "Seconds between reseeding of ISN secret"); 227 228 /* 229 * TCP bandwidth limiting sysctls. Note that the default lower bound of 230 * 1024 exists only for debugging. A good production default would be 231 * something like 6100. 232 */ 233 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, inflight, CTLFLAG_RW, 0, 234 "TCP inflight data limiting"); 235 236 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, enable, CTLFLAG_RW, 237 &VNET_NAME(tcp_inflight_enable), 0, 238 "Enable automatic TCP inflight data limiting"); 239 240 static int tcp_inflight_debug = 0; 241 SYSCTL_INT(_net_inet_tcp_inflight, OID_AUTO, debug, CTLFLAG_RW, 242 &tcp_inflight_debug, 0, 243 "Debug TCP inflight calculations"); 244 245 SYSCTL_VNET_PROC(_net_inet_tcp_inflight, OID_AUTO, rttthresh, 246 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_inflight_rttthresh), 0, 247 vnet_sysctl_msec_to_ticks, "I", 248 "RTT threshold below which inflight will deactivate itself"); 249 250 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, min, CTLFLAG_RW, 251 &VNET_NAME(tcp_inflight_min), 0, 252 "Lower-bound for TCP inflight window"); 253 254 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, max, CTLFLAG_RW, 255 &VNET_NAME(tcp_inflight_max), 0, 256 "Upper-bound for TCP inflight window"); 257 258 SYSCTL_VNET_INT(_net_inet_tcp_inflight, OID_AUTO, stab, CTLFLAG_RW, 259 &VNET_NAME(tcp_inflight_stab), 0, 260 "Inflight Algorithm Stabilization 20 = 2 packets"); 261 262 #ifdef TCP_SORECEIVE_STREAM 263 static int tcp_soreceive_stream = 0; 264 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 265 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 266 #endif 267 268 VNET_DEFINE(uma_zone_t, sack_hole_zone); 269 #define V_sack_hole_zone VNET(sack_hole_zone) 270 271 static struct inpcb *tcp_notify(struct inpcb *, int); 272 static void tcp_isn_tick(void *); 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 V_blackhole = 0; 333 V_tcp_delack_enabled = 1; 334 V_drop_synfin = 0; 335 V_tcp_do_rfc3042 = 1; 336 V_tcp_do_rfc3390 = 1; 337 V_tcp_do_ecn = 0; 338 V_tcp_ecn_maxretries = 1; 339 V_tcp_insecure_rst = 0; 340 V_tcp_do_autorcvbuf = 1; 341 V_tcp_autorcvbuf_inc = 16*1024; 342 V_tcp_autorcvbuf_max = 256*1024; 343 V_tcp_do_rfc3465 = 1; 344 V_tcp_abc_l_var = 2; 345 346 V_tcp_mssdflt = TCP_MSS; 347 #ifdef INET6 348 V_tcp_v6mssdflt = TCP6_MSS; 349 #endif 350 V_tcp_minmss = TCP_MINMSS; 351 V_tcp_do_rfc1323 = 1; 352 V_icmp_may_rst = 1; 353 V_tcp_isn_reseed_interval = 0; 354 V_tcp_inflight_enable = 1; 355 V_tcp_inflight_min = 6144; 356 V_tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 357 V_tcp_inflight_stab = 20; 358 359 V_path_mtu_discovery = 1; 360 V_ss_fltsz = 1; 361 V_ss_fltsz_local = 4; 362 V_tcp_do_newreno = 1; 363 V_tcp_do_tso = 1; 364 V_tcp_do_autosndbuf = 1; 365 V_tcp_autosndbuf_inc = 8*1024; 366 V_tcp_autosndbuf_max = 256*1024; 367 368 V_nolocaltimewait = 0; 369 370 V_tcp_do_sack = 1; 371 V_tcp_sack_maxholes = 128; 372 V_tcp_sack_globalmaxholes = 65536; 373 V_tcp_sack_globalholes = 0; 374 375 V_tcp_inflight_rttthresh = TCPTV_INFLIGHT_RTTTHRESH; 376 377 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 378 379 hashsize = TCBHASHSIZE; 380 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 381 if (!powerof2(hashsize)) { 382 printf("WARNING: TCB hash size not a power of 2\n"); 383 hashsize = 512; /* safe default */ 384 } 385 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 386 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE); 387 388 /* 389 * These have to be type stable for the benefit of the timers. 390 */ 391 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 392 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 393 uma_zone_set_max(V_tcpcb_zone, maxsockets); 394 tcp_tw_init(); 395 syncache_init(); 396 tcp_hc_init(); 397 tcp_reass_init(); 398 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 399 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 400 401 /* Skip initialization of globals for non-default instances. */ 402 if (!IS_DEFAULT_VNET(curvnet)) 403 return; 404 405 /* XXX virtualize those bellow? */ 406 tcp_delacktime = TCPTV_DELACK; 407 tcp_keepinit = TCPTV_KEEP_INIT; 408 tcp_keepidle = TCPTV_KEEP_IDLE; 409 tcp_keepintvl = TCPTV_KEEPINTVL; 410 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 411 tcp_msl = TCPTV_MSL; 412 tcp_rexmit_min = TCPTV_MIN; 413 if (tcp_rexmit_min < 1) 414 tcp_rexmit_min = 1; 415 tcp_rexmit_slop = TCPTV_CPU_VAR; 416 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 417 tcp_tcbhashsize = hashsize; 418 419 #ifdef TCP_SORECEIVE_STREAM 420 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 421 if (tcp_soreceive_stream) { 422 tcp_usrreqs.pru_soreceive = soreceive_stream; 423 tcp6_usrreqs.pru_soreceive = soreceive_stream; 424 } 425 #endif 426 427 #ifdef INET6 428 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 429 #else /* INET6 */ 430 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 431 #endif /* INET6 */ 432 if (max_protohdr < TCP_MINPROTOHDR) 433 max_protohdr = TCP_MINPROTOHDR; 434 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 435 panic("tcp_init"); 436 #undef TCP_MINPROTOHDR 437 438 ISN_LOCK_INIT(); 439 callout_init(&isn_callout, CALLOUT_MPSAFE); 440 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 441 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 442 SHUTDOWN_PRI_DEFAULT); 443 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 444 EVENTHANDLER_PRI_ANY); 445 } 446 447 #ifdef VIMAGE 448 void 449 tcp_destroy(void) 450 { 451 452 tcp_reass_destroy(); 453 tcp_hc_destroy(); 454 syncache_destroy(); 455 tcp_tw_destroy(); 456 in_pcbinfo_destroy(&V_tcbinfo); 457 uma_zdestroy(V_sack_hole_zone); 458 uma_zdestroy(V_tcpcb_zone); 459 } 460 #endif 461 462 void 463 tcp_fini(void *xtp) 464 { 465 466 callout_stop(&isn_callout); 467 } 468 469 /* 470 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 471 * tcp_template used to store this data in mbufs, but we now recopy it out 472 * of the tcpcb each time to conserve mbufs. 473 */ 474 void 475 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 476 { 477 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 478 479 INP_WLOCK_ASSERT(inp); 480 481 #ifdef INET6 482 if ((inp->inp_vflag & INP_IPV6) != 0) { 483 struct ip6_hdr *ip6; 484 485 ip6 = (struct ip6_hdr *)ip_ptr; 486 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 487 (inp->inp_flow & IPV6_FLOWINFO_MASK); 488 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 489 (IPV6_VERSION & IPV6_VERSION_MASK); 490 ip6->ip6_nxt = IPPROTO_TCP; 491 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 492 ip6->ip6_src = inp->in6p_laddr; 493 ip6->ip6_dst = inp->in6p_faddr; 494 } else 495 #endif 496 { 497 struct ip *ip; 498 499 ip = (struct ip *)ip_ptr; 500 ip->ip_v = IPVERSION; 501 ip->ip_hl = 5; 502 ip->ip_tos = inp->inp_ip_tos; 503 ip->ip_len = 0; 504 ip->ip_id = 0; 505 ip->ip_off = 0; 506 ip->ip_ttl = inp->inp_ip_ttl; 507 ip->ip_sum = 0; 508 ip->ip_p = IPPROTO_TCP; 509 ip->ip_src = inp->inp_laddr; 510 ip->ip_dst = inp->inp_faddr; 511 } 512 th->th_sport = inp->inp_lport; 513 th->th_dport = inp->inp_fport; 514 th->th_seq = 0; 515 th->th_ack = 0; 516 th->th_x2 = 0; 517 th->th_off = 5; 518 th->th_flags = 0; 519 th->th_win = 0; 520 th->th_urp = 0; 521 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 522 } 523 524 /* 525 * Create template to be used to send tcp packets on a connection. 526 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 527 * use for this function is in keepalives, which use tcp_respond. 528 */ 529 struct tcptemp * 530 tcpip_maketemplate(struct inpcb *inp) 531 { 532 struct tcptemp *t; 533 534 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 535 if (t == NULL) 536 return (NULL); 537 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 538 return (t); 539 } 540 541 /* 542 * Send a single message to the TCP at address specified by 543 * the given TCP/IP header. If m == NULL, then we make a copy 544 * of the tcpiphdr at ti and send directly to the addressed host. 545 * This is used to force keep alive messages out using the TCP 546 * template for a connection. If flags are given then we send 547 * a message back to the TCP which originated the * segment ti, 548 * and discard the mbuf containing it and any other attached mbufs. 549 * 550 * In any case the ack and sequence number of the transmitted 551 * segment are as specified by the parameters. 552 * 553 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 554 */ 555 void 556 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 557 tcp_seq ack, tcp_seq seq, int flags) 558 { 559 int tlen; 560 int win = 0; 561 struct ip *ip; 562 struct tcphdr *nth; 563 #ifdef INET6 564 struct ip6_hdr *ip6; 565 int isipv6; 566 #endif /* INET6 */ 567 int ipflags = 0; 568 struct inpcb *inp; 569 570 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 571 572 #ifdef INET6 573 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 574 ip6 = ipgen; 575 #endif /* INET6 */ 576 ip = ipgen; 577 578 if (tp != NULL) { 579 inp = tp->t_inpcb; 580 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 581 INP_WLOCK_ASSERT(inp); 582 } else 583 inp = NULL; 584 585 if (tp != NULL) { 586 if (!(flags & TH_RST)) { 587 win = sbspace(&inp->inp_socket->so_rcv); 588 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 589 win = (long)TCP_MAXWIN << tp->rcv_scale; 590 } 591 } 592 if (m == NULL) { 593 m = m_gethdr(M_DONTWAIT, MT_DATA); 594 if (m == NULL) 595 return; 596 tlen = 0; 597 m->m_data += max_linkhdr; 598 #ifdef INET6 599 if (isipv6) { 600 bcopy((caddr_t)ip6, mtod(m, caddr_t), 601 sizeof(struct ip6_hdr)); 602 ip6 = mtod(m, struct ip6_hdr *); 603 nth = (struct tcphdr *)(ip6 + 1); 604 } else 605 #endif /* INET6 */ 606 { 607 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 608 ip = mtod(m, struct ip *); 609 nth = (struct tcphdr *)(ip + 1); 610 } 611 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 612 flags = TH_ACK; 613 } else { 614 /* 615 * reuse the mbuf. 616 * XXX MRT We inherrit the FIB, which is lucky. 617 */ 618 m_freem(m->m_next); 619 m->m_next = NULL; 620 m->m_data = (caddr_t)ipgen; 621 /* m_len is set later */ 622 tlen = 0; 623 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 624 #ifdef INET6 625 if (isipv6) { 626 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 627 nth = (struct tcphdr *)(ip6 + 1); 628 } else 629 #endif /* INET6 */ 630 { 631 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 632 nth = (struct tcphdr *)(ip + 1); 633 } 634 if (th != nth) { 635 /* 636 * this is usually a case when an extension header 637 * exists between the IPv6 header and the 638 * TCP header. 639 */ 640 nth->th_sport = th->th_sport; 641 nth->th_dport = th->th_dport; 642 } 643 xchg(nth->th_dport, nth->th_sport, uint16_t); 644 #undef xchg 645 } 646 #ifdef INET6 647 if (isipv6) { 648 ip6->ip6_flow = 0; 649 ip6->ip6_vfc = IPV6_VERSION; 650 ip6->ip6_nxt = IPPROTO_TCP; 651 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 652 tlen)); 653 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 654 } else 655 #endif 656 { 657 tlen += sizeof (struct tcpiphdr); 658 ip->ip_len = tlen; 659 ip->ip_ttl = V_ip_defttl; 660 if (V_path_mtu_discovery) 661 ip->ip_off |= IP_DF; 662 } 663 m->m_len = tlen; 664 m->m_pkthdr.len = tlen; 665 m->m_pkthdr.rcvif = NULL; 666 #ifdef MAC 667 if (inp != NULL) { 668 /* 669 * Packet is associated with a socket, so allow the 670 * label of the response to reflect the socket label. 671 */ 672 INP_WLOCK_ASSERT(inp); 673 mac_inpcb_create_mbuf(inp, m); 674 } else { 675 /* 676 * Packet is not associated with a socket, so possibly 677 * update the label in place. 678 */ 679 mac_netinet_tcp_reply(m); 680 } 681 #endif 682 nth->th_seq = htonl(seq); 683 nth->th_ack = htonl(ack); 684 nth->th_x2 = 0; 685 nth->th_off = sizeof (struct tcphdr) >> 2; 686 nth->th_flags = flags; 687 if (tp != NULL) 688 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 689 else 690 nth->th_win = htons((u_short)win); 691 nth->th_urp = 0; 692 #ifdef INET6 693 if (isipv6) { 694 nth->th_sum = 0; 695 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 696 sizeof(struct ip6_hdr), 697 tlen - sizeof(struct ip6_hdr)); 698 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 699 NULL, NULL); 700 } else 701 #endif /* INET6 */ 702 { 703 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 704 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 705 m->m_pkthdr.csum_flags = CSUM_TCP; 706 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 707 } 708 #ifdef TCPDEBUG 709 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 710 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 711 #endif 712 #ifdef INET6 713 if (isipv6) 714 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 715 else 716 #endif /* INET6 */ 717 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 718 } 719 720 /* 721 * Create a new TCP control block, making an 722 * empty reassembly queue and hooking it to the argument 723 * protocol control block. The `inp' parameter must have 724 * come from the zone allocator set up in tcp_init(). 725 */ 726 struct tcpcb * 727 tcp_newtcpcb(struct inpcb *inp) 728 { 729 struct tcpcb_mem *tm; 730 struct tcpcb *tp; 731 #ifdef INET6 732 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 733 #endif /* INET6 */ 734 735 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 736 if (tm == NULL) 737 return (NULL); 738 tp = &tm->tcb; 739 #ifdef VIMAGE 740 tp->t_vnet = inp->inp_vnet; 741 #endif 742 tp->t_timers = &tm->tt; 743 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 744 tp->t_maxseg = tp->t_maxopd = 745 #ifdef INET6 746 isipv6 ? V_tcp_v6mssdflt : 747 #endif /* INET6 */ 748 V_tcp_mssdflt; 749 750 /* Set up our timeouts. */ 751 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 752 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 753 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 754 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 755 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 756 757 if (V_tcp_do_rfc1323) 758 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 759 if (V_tcp_do_sack) 760 tp->t_flags |= TF_SACK_PERMIT; 761 TAILQ_INIT(&tp->snd_holes); 762 tp->t_inpcb = inp; /* XXX */ 763 /* 764 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 765 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 766 * reasonable initial retransmit time. 767 */ 768 tp->t_srtt = TCPTV_SRTTBASE; 769 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 770 tp->t_rttmin = tcp_rexmit_min; 771 tp->t_rxtcur = TCPTV_RTOBASE; 772 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 773 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 774 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 775 tp->t_rcvtime = ticks; 776 tp->t_bw_rtttime = ticks; 777 /* 778 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 779 * because the socket may be bound to an IPv6 wildcard address, 780 * which may match an IPv4-mapped IPv6 address. 781 */ 782 inp->inp_ip_ttl = V_ip_defttl; 783 inp->inp_ppcb = tp; 784 return (tp); /* XXX */ 785 } 786 787 /* 788 * Drop a TCP connection, reporting 789 * the specified error. If connection is synchronized, 790 * then send a RST to peer. 791 */ 792 struct tcpcb * 793 tcp_drop(struct tcpcb *tp, int errno) 794 { 795 struct socket *so = tp->t_inpcb->inp_socket; 796 797 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 798 INP_WLOCK_ASSERT(tp->t_inpcb); 799 800 if (TCPS_HAVERCVDSYN(tp->t_state)) { 801 tp->t_state = TCPS_CLOSED; 802 (void) tcp_output_reset(tp); 803 TCPSTAT_INC(tcps_drops); 804 } else 805 TCPSTAT_INC(tcps_conndrops); 806 if (errno == ETIMEDOUT && tp->t_softerror) 807 errno = tp->t_softerror; 808 so->so_error = errno; 809 return (tcp_close(tp)); 810 } 811 812 void 813 tcp_discardcb(struct tcpcb *tp) 814 { 815 struct tseg_qent *q; 816 struct inpcb *inp = tp->t_inpcb; 817 struct socket *so = inp->inp_socket; 818 #ifdef INET6 819 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 820 #endif /* INET6 */ 821 822 INP_WLOCK_ASSERT(inp); 823 824 /* 825 * Make sure that all of our timers are stopped before we delete the 826 * PCB. 827 * 828 * XXXRW: Really, we would like to use callout_drain() here in order 829 * to avoid races experienced in tcp_timer.c where a timer is already 830 * executing at this point. However, we can't, both because we're 831 * running in a context where we can't sleep, and also because we 832 * hold locks required by the timers. What we instead need to do is 833 * test to see if callout_drain() is required, and if so, defer some 834 * portion of the remainder of tcp_discardcb() to an asynchronous 835 * context that can callout_drain() and then continue. Some care 836 * will be required to ensure that no further processing takes place 837 * on the tcpcb, even though it hasn't been freed (a flag?). 838 */ 839 callout_stop(&tp->t_timers->tt_rexmt); 840 callout_stop(&tp->t_timers->tt_persist); 841 callout_stop(&tp->t_timers->tt_keep); 842 callout_stop(&tp->t_timers->tt_2msl); 843 callout_stop(&tp->t_timers->tt_delack); 844 845 /* 846 * If we got enough samples through the srtt filter, 847 * save the rtt and rttvar in the routing entry. 848 * 'Enough' is arbitrarily defined as 4 rtt samples. 849 * 4 samples is enough for the srtt filter to converge 850 * to within enough % of the correct value; fewer samples 851 * and we could save a bogus rtt. The danger is not high 852 * as tcp quickly recovers from everything. 853 * XXX: Works very well but needs some more statistics! 854 */ 855 if (tp->t_rttupdated >= 4) { 856 struct hc_metrics_lite metrics; 857 u_long ssthresh; 858 859 bzero(&metrics, sizeof(metrics)); 860 /* 861 * Update the ssthresh always when the conditions below 862 * are satisfied. This gives us better new start value 863 * for the congestion avoidance for new connections. 864 * ssthresh is only set if packet loss occured on a session. 865 * 866 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 867 * being torn down. Ideally this code would not use 'so'. 868 */ 869 ssthresh = tp->snd_ssthresh; 870 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 871 /* 872 * convert the limit from user data bytes to 873 * packets then to packet data bytes. 874 */ 875 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 876 if (ssthresh < 2) 877 ssthresh = 2; 878 ssthresh *= (u_long)(tp->t_maxseg + 879 #ifdef INET6 880 (isipv6 ? sizeof (struct ip6_hdr) + 881 sizeof (struct tcphdr) : 882 #endif 883 sizeof (struct tcpiphdr) 884 #ifdef INET6 885 ) 886 #endif 887 ); 888 } else 889 ssthresh = 0; 890 metrics.rmx_ssthresh = ssthresh; 891 892 metrics.rmx_rtt = tp->t_srtt; 893 metrics.rmx_rttvar = tp->t_rttvar; 894 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 895 metrics.rmx_bandwidth = tp->snd_bandwidth; 896 metrics.rmx_cwnd = tp->snd_cwnd; 897 metrics.rmx_sendpipe = 0; 898 metrics.rmx_recvpipe = 0; 899 900 tcp_hc_update(&inp->inp_inc, &metrics); 901 } 902 903 /* free the reassembly queue, if any */ 904 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 905 LIST_REMOVE(q, tqe_q); 906 m_freem(q->tqe_m); 907 uma_zfree(V_tcp_reass_zone, q); 908 tp->t_segqlen--; 909 V_tcp_reass_qsize--; 910 } 911 /* Disconnect offload device, if any. */ 912 tcp_offload_detach(tp); 913 914 tcp_free_sackholes(tp); 915 inp->inp_ppcb = NULL; 916 tp->t_inpcb = NULL; 917 uma_zfree(V_tcpcb_zone, tp); 918 } 919 920 /* 921 * Attempt to close a TCP control block, marking it as dropped, and freeing 922 * the socket if we hold the only reference. 923 */ 924 struct tcpcb * 925 tcp_close(struct tcpcb *tp) 926 { 927 struct inpcb *inp = tp->t_inpcb; 928 struct socket *so; 929 930 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 931 INP_WLOCK_ASSERT(inp); 932 933 /* Notify any offload devices of listener close */ 934 if (tp->t_state == TCPS_LISTEN) 935 tcp_offload_listen_close(tp); 936 in_pcbdrop(inp); 937 TCPSTAT_INC(tcps_closed); 938 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 939 so = inp->inp_socket; 940 soisdisconnected(so); 941 if (inp->inp_flags & INP_SOCKREF) { 942 KASSERT(so->so_state & SS_PROTOREF, 943 ("tcp_close: !SS_PROTOREF")); 944 inp->inp_flags &= ~INP_SOCKREF; 945 INP_WUNLOCK(inp); 946 ACCEPT_LOCK(); 947 SOCK_LOCK(so); 948 so->so_state &= ~SS_PROTOREF; 949 sofree(so); 950 return (NULL); 951 } 952 return (tp); 953 } 954 955 void 956 tcp_drain(void) 957 { 958 VNET_ITERATOR_DECL(vnet_iter); 959 960 if (!do_tcpdrain) 961 return; 962 963 VNET_LIST_RLOCK_NOSLEEP(); 964 VNET_FOREACH(vnet_iter) { 965 CURVNET_SET(vnet_iter); 966 struct inpcb *inpb; 967 struct tcpcb *tcpb; 968 struct tseg_qent *te; 969 970 /* 971 * Walk the tcpbs, if existing, and flush the reassembly queue, 972 * if there is one... 973 * XXX: The "Net/3" implementation doesn't imply that the TCP 974 * reassembly queue should be flushed, but in a situation 975 * where we're really low on mbufs, this is potentially 976 * usefull. 977 */ 978 INP_INFO_RLOCK(&V_tcbinfo); 979 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 980 if (inpb->inp_flags & INP_TIMEWAIT) 981 continue; 982 INP_WLOCK(inpb); 983 if ((tcpb = intotcpcb(inpb)) != NULL) { 984 while ((te = LIST_FIRST(&tcpb->t_segq)) 985 != NULL) { 986 LIST_REMOVE(te, tqe_q); 987 m_freem(te->tqe_m); 988 uma_zfree(V_tcp_reass_zone, te); 989 tcpb->t_segqlen--; 990 V_tcp_reass_qsize--; 991 } 992 tcp_clean_sackreport(tcpb); 993 } 994 INP_WUNLOCK(inpb); 995 } 996 INP_INFO_RUNLOCK(&V_tcbinfo); 997 CURVNET_RESTORE(); 998 } 999 VNET_LIST_RUNLOCK_NOSLEEP(); 1000 } 1001 1002 /* 1003 * Notify a tcp user of an asynchronous error; 1004 * store error as soft error, but wake up user 1005 * (for now, won't do anything until can select for soft error). 1006 * 1007 * Do not wake up user since there currently is no mechanism for 1008 * reporting soft errors (yet - a kqueue filter may be added). 1009 */ 1010 static struct inpcb * 1011 tcp_notify(struct inpcb *inp, int error) 1012 { 1013 struct tcpcb *tp; 1014 1015 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1016 INP_WLOCK_ASSERT(inp); 1017 1018 if ((inp->inp_flags & INP_TIMEWAIT) || 1019 (inp->inp_flags & INP_DROPPED)) 1020 return (inp); 1021 1022 tp = intotcpcb(inp); 1023 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1024 1025 /* 1026 * Ignore some errors if we are hooked up. 1027 * If connection hasn't completed, has retransmitted several times, 1028 * and receives a second error, give up now. This is better 1029 * than waiting a long time to establish a connection that 1030 * can never complete. 1031 */ 1032 if (tp->t_state == TCPS_ESTABLISHED && 1033 (error == EHOSTUNREACH || error == ENETUNREACH || 1034 error == EHOSTDOWN)) { 1035 return (inp); 1036 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1037 tp->t_softerror) { 1038 tp = tcp_drop(tp, error); 1039 if (tp != NULL) 1040 return (inp); 1041 else 1042 return (NULL); 1043 } else { 1044 tp->t_softerror = error; 1045 return (inp); 1046 } 1047 #if 0 1048 wakeup( &so->so_timeo); 1049 sorwakeup(so); 1050 sowwakeup(so); 1051 #endif 1052 } 1053 1054 static int 1055 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1056 { 1057 int error, i, m, n, pcb_count; 1058 struct inpcb *inp, **inp_list; 1059 inp_gen_t gencnt; 1060 struct xinpgen xig; 1061 1062 /* 1063 * The process of preparing the TCB list is too time-consuming and 1064 * resource-intensive to repeat twice on every request. 1065 */ 1066 if (req->oldptr == NULL) { 1067 m = syncache_pcbcount(); 1068 n = V_tcbinfo.ipi_count; 1069 req->oldidx = 2 * (sizeof xig) 1070 + ((m + n) + n/8) * sizeof(struct xtcpcb); 1071 return (0); 1072 } 1073 1074 if (req->newptr != NULL) 1075 return (EPERM); 1076 1077 /* 1078 * OK, now we're committed to doing something. 1079 */ 1080 INP_INFO_RLOCK(&V_tcbinfo); 1081 gencnt = V_tcbinfo.ipi_gencnt; 1082 n = V_tcbinfo.ipi_count; 1083 INP_INFO_RUNLOCK(&V_tcbinfo); 1084 1085 m = syncache_pcbcount(); 1086 1087 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1088 + (n + m) * sizeof(struct xtcpcb)); 1089 if (error != 0) 1090 return (error); 1091 1092 xig.xig_len = sizeof xig; 1093 xig.xig_count = n + m; 1094 xig.xig_gen = gencnt; 1095 xig.xig_sogen = so_gencnt; 1096 error = SYSCTL_OUT(req, &xig, sizeof xig); 1097 if (error) 1098 return (error); 1099 1100 error = syncache_pcblist(req, m, &pcb_count); 1101 if (error) 1102 return (error); 1103 1104 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1105 if (inp_list == NULL) 1106 return (ENOMEM); 1107 1108 INP_INFO_RLOCK(&V_tcbinfo); 1109 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1110 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1111 INP_WLOCK(inp); 1112 if (inp->inp_gencnt <= gencnt) { 1113 /* 1114 * XXX: This use of cr_cansee(), introduced with 1115 * TCP state changes, is not quite right, but for 1116 * now, better than nothing. 1117 */ 1118 if (inp->inp_flags & INP_TIMEWAIT) { 1119 if (intotw(inp) != NULL) 1120 error = cr_cansee(req->td->td_ucred, 1121 intotw(inp)->tw_cred); 1122 else 1123 error = EINVAL; /* Skip this inp. */ 1124 } else 1125 error = cr_canseeinpcb(req->td->td_ucred, inp); 1126 if (error == 0) { 1127 in_pcbref(inp); 1128 inp_list[i++] = inp; 1129 } 1130 } 1131 INP_WUNLOCK(inp); 1132 } 1133 INP_INFO_RUNLOCK(&V_tcbinfo); 1134 n = i; 1135 1136 error = 0; 1137 for (i = 0; i < n; i++) { 1138 inp = inp_list[i]; 1139 INP_RLOCK(inp); 1140 if (inp->inp_gencnt <= gencnt) { 1141 struct xtcpcb xt; 1142 void *inp_ppcb; 1143 1144 bzero(&xt, sizeof(xt)); 1145 xt.xt_len = sizeof xt; 1146 /* XXX should avoid extra copy */ 1147 bcopy(inp, &xt.xt_inp, sizeof *inp); 1148 inp_ppcb = inp->inp_ppcb; 1149 if (inp_ppcb == NULL) 1150 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1151 else if (inp->inp_flags & INP_TIMEWAIT) { 1152 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1153 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1154 } else { 1155 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1156 if (xt.xt_tp.t_timers) 1157 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1158 } 1159 if (inp->inp_socket != NULL) 1160 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1161 else { 1162 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1163 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1164 } 1165 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1166 INP_RUNLOCK(inp); 1167 error = SYSCTL_OUT(req, &xt, sizeof xt); 1168 } else 1169 INP_RUNLOCK(inp); 1170 } 1171 INP_INFO_WLOCK(&V_tcbinfo); 1172 for (i = 0; i < n; i++) { 1173 inp = inp_list[i]; 1174 INP_WLOCK(inp); 1175 if (!in_pcbrele(inp)) 1176 INP_WUNLOCK(inp); 1177 } 1178 INP_INFO_WUNLOCK(&V_tcbinfo); 1179 1180 if (!error) { 1181 /* 1182 * Give the user an updated idea of our state. 1183 * If the generation differs from what we told 1184 * her before, she knows that something happened 1185 * while we were processing this request, and it 1186 * might be necessary to retry. 1187 */ 1188 INP_INFO_RLOCK(&V_tcbinfo); 1189 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1190 xig.xig_sogen = so_gencnt; 1191 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1192 INP_INFO_RUNLOCK(&V_tcbinfo); 1193 error = SYSCTL_OUT(req, &xig, sizeof xig); 1194 } 1195 free(inp_list, M_TEMP); 1196 return (error); 1197 } 1198 1199 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1200 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1201 1202 static int 1203 tcp_getcred(SYSCTL_HANDLER_ARGS) 1204 { 1205 struct xucred xuc; 1206 struct sockaddr_in addrs[2]; 1207 struct inpcb *inp; 1208 int error; 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 INP_INFO_RLOCK(&V_tcbinfo); 1217 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1218 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1219 if (inp != NULL) { 1220 INP_RLOCK(inp); 1221 INP_INFO_RUNLOCK(&V_tcbinfo); 1222 if (inp->inp_socket == NULL) 1223 error = ENOENT; 1224 if (error == 0) 1225 error = cr_canseeinpcb(req->td->td_ucred, inp); 1226 if (error == 0) 1227 cru2x(inp->inp_cred, &xuc); 1228 INP_RUNLOCK(inp); 1229 } else { 1230 INP_INFO_RUNLOCK(&V_tcbinfo); 1231 error = ENOENT; 1232 } 1233 if (error == 0) 1234 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1235 return (error); 1236 } 1237 1238 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1239 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1240 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1241 1242 #ifdef INET6 1243 static int 1244 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1245 { 1246 struct xucred xuc; 1247 struct sockaddr_in6 addrs[2]; 1248 struct inpcb *inp; 1249 int error, mapped = 0; 1250 1251 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1252 if (error) 1253 return (error); 1254 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1255 if (error) 1256 return (error); 1257 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1258 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1259 return (error); 1260 } 1261 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1262 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1263 mapped = 1; 1264 else 1265 return (EINVAL); 1266 } 1267 1268 INP_INFO_RLOCK(&V_tcbinfo); 1269 if (mapped == 1) 1270 inp = in_pcblookup_hash(&V_tcbinfo, 1271 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1272 addrs[1].sin6_port, 1273 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1274 addrs[0].sin6_port, 1275 0, NULL); 1276 else 1277 inp = in6_pcblookup_hash(&V_tcbinfo, 1278 &addrs[1].sin6_addr, addrs[1].sin6_port, 1279 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1280 if (inp != NULL) { 1281 INP_RLOCK(inp); 1282 INP_INFO_RUNLOCK(&V_tcbinfo); 1283 if (inp->inp_socket == NULL) 1284 error = ENOENT; 1285 if (error == 0) 1286 error = cr_canseeinpcb(req->td->td_ucred, inp); 1287 if (error == 0) 1288 cru2x(inp->inp_cred, &xuc); 1289 INP_RUNLOCK(inp); 1290 } else { 1291 INP_INFO_RUNLOCK(&V_tcbinfo); 1292 error = ENOENT; 1293 } 1294 if (error == 0) 1295 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1296 return (error); 1297 } 1298 1299 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1300 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1301 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1302 #endif 1303 1304 1305 void 1306 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1307 { 1308 struct ip *ip = vip; 1309 struct tcphdr *th; 1310 struct in_addr faddr; 1311 struct inpcb *inp; 1312 struct tcpcb *tp; 1313 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1314 struct icmp *icp; 1315 struct in_conninfo inc; 1316 tcp_seq icmp_tcp_seq; 1317 int mtu; 1318 1319 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1320 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1321 return; 1322 1323 if (cmd == PRC_MSGSIZE) 1324 notify = tcp_mtudisc; 1325 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1326 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1327 notify = tcp_drop_syn_sent; 1328 /* 1329 * Redirects don't need to be handled up here. 1330 */ 1331 else if (PRC_IS_REDIRECT(cmd)) 1332 return; 1333 /* 1334 * Source quench is depreciated. 1335 */ 1336 else if (cmd == PRC_QUENCH) 1337 return; 1338 /* 1339 * Hostdead is ugly because it goes linearly through all PCBs. 1340 * XXX: We never get this from ICMP, otherwise it makes an 1341 * excellent DoS attack on machines with many connections. 1342 */ 1343 else if (cmd == PRC_HOSTDEAD) 1344 ip = NULL; 1345 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1346 return; 1347 if (ip != NULL) { 1348 icp = (struct icmp *)((caddr_t)ip 1349 - offsetof(struct icmp, icmp_ip)); 1350 th = (struct tcphdr *)((caddr_t)ip 1351 + (ip->ip_hl << 2)); 1352 INP_INFO_WLOCK(&V_tcbinfo); 1353 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1354 ip->ip_src, th->th_sport, 0, NULL); 1355 if (inp != NULL) { 1356 INP_WLOCK(inp); 1357 if (!(inp->inp_flags & INP_TIMEWAIT) && 1358 !(inp->inp_flags & INP_DROPPED) && 1359 !(inp->inp_socket == NULL)) { 1360 icmp_tcp_seq = htonl(th->th_seq); 1361 tp = intotcpcb(inp); 1362 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1363 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1364 if (cmd == PRC_MSGSIZE) { 1365 /* 1366 * MTU discovery: 1367 * If we got a needfrag set the MTU 1368 * in the route to the suggested new 1369 * value (if given) and then notify. 1370 */ 1371 bzero(&inc, sizeof(inc)); 1372 inc.inc_faddr = faddr; 1373 inc.inc_fibnum = 1374 inp->inp_inc.inc_fibnum; 1375 1376 mtu = ntohs(icp->icmp_nextmtu); 1377 /* 1378 * If no alternative MTU was 1379 * proposed, try the next smaller 1380 * one. ip->ip_len has already 1381 * been swapped in icmp_input(). 1382 */ 1383 if (!mtu) 1384 mtu = ip_next_mtu(ip->ip_len, 1385 1); 1386 if (mtu < max(296, V_tcp_minmss 1387 + sizeof(struct tcpiphdr))) 1388 mtu = 0; 1389 if (!mtu) 1390 mtu = V_tcp_mssdflt 1391 + sizeof(struct tcpiphdr); 1392 /* 1393 * Only cache the the MTU if it 1394 * is smaller than the interface 1395 * or route MTU. tcp_mtudisc() 1396 * will do right thing by itself. 1397 */ 1398 if (mtu <= tcp_maxmtu(&inc, NULL)) 1399 tcp_hc_updatemtu(&inc, mtu); 1400 } 1401 1402 inp = (*notify)(inp, inetctlerrmap[cmd]); 1403 } 1404 } 1405 if (inp != NULL) 1406 INP_WUNLOCK(inp); 1407 } else { 1408 bzero(&inc, sizeof(inc)); 1409 inc.inc_fport = th->th_dport; 1410 inc.inc_lport = th->th_sport; 1411 inc.inc_faddr = faddr; 1412 inc.inc_laddr = ip->ip_src; 1413 syncache_unreach(&inc, th); 1414 } 1415 INP_INFO_WUNLOCK(&V_tcbinfo); 1416 } else 1417 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1418 } 1419 1420 #ifdef INET6 1421 void 1422 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1423 { 1424 struct tcphdr th; 1425 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1426 struct ip6_hdr *ip6; 1427 struct mbuf *m; 1428 struct ip6ctlparam *ip6cp = NULL; 1429 const struct sockaddr_in6 *sa6_src = NULL; 1430 int off; 1431 struct tcp_portonly { 1432 u_int16_t th_sport; 1433 u_int16_t th_dport; 1434 } *thp; 1435 1436 if (sa->sa_family != AF_INET6 || 1437 sa->sa_len != sizeof(struct sockaddr_in6)) 1438 return; 1439 1440 if (cmd == PRC_MSGSIZE) 1441 notify = tcp_mtudisc; 1442 else if (!PRC_IS_REDIRECT(cmd) && 1443 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1444 return; 1445 /* Source quench is depreciated. */ 1446 else if (cmd == PRC_QUENCH) 1447 return; 1448 1449 /* if the parameter is from icmp6, decode it. */ 1450 if (d != NULL) { 1451 ip6cp = (struct ip6ctlparam *)d; 1452 m = ip6cp->ip6c_m; 1453 ip6 = ip6cp->ip6c_ip6; 1454 off = ip6cp->ip6c_off; 1455 sa6_src = ip6cp->ip6c_src; 1456 } else { 1457 m = NULL; 1458 ip6 = NULL; 1459 off = 0; /* fool gcc */ 1460 sa6_src = &sa6_any; 1461 } 1462 1463 if (ip6 != NULL) { 1464 struct in_conninfo inc; 1465 /* 1466 * XXX: We assume that when IPV6 is non NULL, 1467 * M and OFF are valid. 1468 */ 1469 1470 /* check if we can safely examine src and dst ports */ 1471 if (m->m_pkthdr.len < off + sizeof(*thp)) 1472 return; 1473 1474 bzero(&th, sizeof(th)); 1475 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1476 1477 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1478 (struct sockaddr *)ip6cp->ip6c_src, 1479 th.th_sport, cmd, NULL, notify); 1480 1481 bzero(&inc, sizeof(inc)); 1482 inc.inc_fport = th.th_dport; 1483 inc.inc_lport = th.th_sport; 1484 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1485 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1486 inc.inc_flags |= INC_ISIPV6; 1487 INP_INFO_WLOCK(&V_tcbinfo); 1488 syncache_unreach(&inc, &th); 1489 INP_INFO_WUNLOCK(&V_tcbinfo); 1490 } else 1491 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1492 0, cmd, NULL, notify); 1493 } 1494 #endif /* INET6 */ 1495 1496 1497 /* 1498 * Following is where TCP initial sequence number generation occurs. 1499 * 1500 * There are two places where we must use initial sequence numbers: 1501 * 1. In SYN-ACK packets. 1502 * 2. In SYN packets. 1503 * 1504 * All ISNs for SYN-ACK packets are generated by the syncache. See 1505 * tcp_syncache.c for details. 1506 * 1507 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1508 * depends on this property. In addition, these ISNs should be 1509 * unguessable so as to prevent connection hijacking. To satisfy 1510 * the requirements of this situation, the algorithm outlined in 1511 * RFC 1948 is used, with only small modifications. 1512 * 1513 * Implementation details: 1514 * 1515 * Time is based off the system timer, and is corrected so that it 1516 * increases by one megabyte per second. This allows for proper 1517 * recycling on high speed LANs while still leaving over an hour 1518 * before rollover. 1519 * 1520 * As reading the *exact* system time is too expensive to be done 1521 * whenever setting up a TCP connection, we increment the time 1522 * offset in two ways. First, a small random positive increment 1523 * is added to isn_offset for each connection that is set up. 1524 * Second, the function tcp_isn_tick fires once per clock tick 1525 * and increments isn_offset as necessary so that sequence numbers 1526 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1527 * random positive increments serve only to ensure that the same 1528 * exact sequence number is never sent out twice (as could otherwise 1529 * happen when a port is recycled in less than the system tick 1530 * interval.) 1531 * 1532 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1533 * between seeding of isn_secret. This is normally set to zero, 1534 * as reseeding should not be necessary. 1535 * 1536 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1537 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1538 * general, this means holding an exclusive (write) lock. 1539 */ 1540 1541 #define ISN_BYTES_PER_SECOND 1048576 1542 #define ISN_STATIC_INCREMENT 4096 1543 #define ISN_RANDOM_INCREMENT (4096 - 1) 1544 1545 static VNET_DEFINE(u_char, isn_secret[32]); 1546 static VNET_DEFINE(int, isn_last_reseed); 1547 static VNET_DEFINE(u_int32_t, isn_offset); 1548 static VNET_DEFINE(u_int32_t, isn_offset_old); 1549 1550 #define V_isn_secret VNET(isn_secret) 1551 #define V_isn_last_reseed VNET(isn_last_reseed) 1552 #define V_isn_offset VNET(isn_offset) 1553 #define V_isn_offset_old VNET(isn_offset_old) 1554 1555 tcp_seq 1556 tcp_new_isn(struct tcpcb *tp) 1557 { 1558 MD5_CTX isn_ctx; 1559 u_int32_t md5_buffer[4]; 1560 tcp_seq new_isn; 1561 1562 INP_WLOCK_ASSERT(tp->t_inpcb); 1563 1564 ISN_LOCK(); 1565 /* Seed if this is the first use, reseed if requested. */ 1566 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1567 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1568 < (u_int)ticks))) { 1569 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1570 V_isn_last_reseed = ticks; 1571 } 1572 1573 /* Compute the md5 hash and return the ISN. */ 1574 MD5Init(&isn_ctx); 1575 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1576 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1577 #ifdef INET6 1578 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1579 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1580 sizeof(struct in6_addr)); 1581 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1582 sizeof(struct in6_addr)); 1583 } else 1584 #endif 1585 { 1586 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1587 sizeof(struct in_addr)); 1588 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1589 sizeof(struct in_addr)); 1590 } 1591 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1592 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1593 new_isn = (tcp_seq) md5_buffer[0]; 1594 V_isn_offset += ISN_STATIC_INCREMENT + 1595 (arc4random() & ISN_RANDOM_INCREMENT); 1596 new_isn += V_isn_offset; 1597 ISN_UNLOCK(); 1598 return (new_isn); 1599 } 1600 1601 /* 1602 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1603 * to keep time flowing at a relatively constant rate. If the random 1604 * increments have already pushed us past the projected offset, do nothing. 1605 */ 1606 static void 1607 tcp_isn_tick(void *xtp) 1608 { 1609 VNET_ITERATOR_DECL(vnet_iter); 1610 u_int32_t projected_offset; 1611 1612 VNET_LIST_RLOCK_NOSLEEP(); 1613 ISN_LOCK(); 1614 VNET_FOREACH(vnet_iter) { 1615 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 1616 projected_offset = 1617 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100; 1618 1619 if (SEQ_GT(projected_offset, V_isn_offset)) 1620 V_isn_offset = projected_offset; 1621 1622 V_isn_offset_old = V_isn_offset; 1623 CURVNET_RESTORE(); 1624 } 1625 ISN_UNLOCK(); 1626 VNET_LIST_RUNLOCK_NOSLEEP(); 1627 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 1628 } 1629 1630 /* 1631 * When a specific ICMP unreachable message is received and the 1632 * connection state is SYN-SENT, drop the connection. This behavior 1633 * is controlled by the icmp_may_rst sysctl. 1634 */ 1635 struct inpcb * 1636 tcp_drop_syn_sent(struct inpcb *inp, int errno) 1637 { 1638 struct tcpcb *tp; 1639 1640 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1641 INP_WLOCK_ASSERT(inp); 1642 1643 if ((inp->inp_flags & INP_TIMEWAIT) || 1644 (inp->inp_flags & INP_DROPPED)) 1645 return (inp); 1646 1647 tp = intotcpcb(inp); 1648 if (tp->t_state != TCPS_SYN_SENT) 1649 return (inp); 1650 1651 tp = tcp_drop(tp, errno); 1652 if (tp != NULL) 1653 return (inp); 1654 else 1655 return (NULL); 1656 } 1657 1658 /* 1659 * When `need fragmentation' ICMP is received, update our idea of the MSS 1660 * based on the new value in the route. Also nudge TCP to send something, 1661 * since we know the packet we just sent was dropped. 1662 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1663 */ 1664 struct inpcb * 1665 tcp_mtudisc(struct inpcb *inp, int errno) 1666 { 1667 struct tcpcb *tp; 1668 struct socket *so; 1669 1670 INP_WLOCK_ASSERT(inp); 1671 if ((inp->inp_flags & INP_TIMEWAIT) || 1672 (inp->inp_flags & INP_DROPPED)) 1673 return (inp); 1674 1675 tp = intotcpcb(inp); 1676 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1677 1678 tcp_mss_update(tp, -1, NULL, NULL); 1679 1680 so = inp->inp_socket; 1681 SOCKBUF_LOCK(&so->so_snd); 1682 /* If the mss is larger than the socket buffer, decrease the mss. */ 1683 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1684 tp->t_maxseg = so->so_snd.sb_hiwat; 1685 SOCKBUF_UNLOCK(&so->so_snd); 1686 1687 TCPSTAT_INC(tcps_mturesent); 1688 tp->t_rtttime = 0; 1689 tp->snd_nxt = tp->snd_una; 1690 tcp_free_sackholes(tp); 1691 tp->snd_recover = tp->snd_max; 1692 if (tp->t_flags & TF_SACK_PERMIT) 1693 EXIT_FASTRECOVERY(tp); 1694 tcp_output_send(tp); 1695 return (inp); 1696 } 1697 1698 /* 1699 * Look-up the routing entry to the peer of this inpcb. If no route 1700 * is found and it cannot be allocated, then return 0. This routine 1701 * is called by TCP routines that access the rmx structure and by 1702 * tcp_mss_update to get the peer/interface MTU. 1703 */ 1704 u_long 1705 tcp_maxmtu(struct in_conninfo *inc, int *flags) 1706 { 1707 struct route sro; 1708 struct sockaddr_in *dst; 1709 struct ifnet *ifp; 1710 u_long maxmtu = 0; 1711 1712 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1713 1714 bzero(&sro, sizeof(sro)); 1715 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1716 dst = (struct sockaddr_in *)&sro.ro_dst; 1717 dst->sin_family = AF_INET; 1718 dst->sin_len = sizeof(*dst); 1719 dst->sin_addr = inc->inc_faddr; 1720 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1721 } 1722 if (sro.ro_rt != NULL) { 1723 ifp = sro.ro_rt->rt_ifp; 1724 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1725 maxmtu = ifp->if_mtu; 1726 else 1727 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1728 1729 /* Report additional interface capabilities. */ 1730 if (flags != NULL) { 1731 if (ifp->if_capenable & IFCAP_TSO4 && 1732 ifp->if_hwassist & CSUM_TSO) 1733 *flags |= CSUM_TSO; 1734 } 1735 RTFREE(sro.ro_rt); 1736 } 1737 return (maxmtu); 1738 } 1739 1740 #ifdef INET6 1741 u_long 1742 tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1743 { 1744 struct route_in6 sro6; 1745 struct ifnet *ifp; 1746 u_long maxmtu = 0; 1747 1748 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1749 1750 bzero(&sro6, sizeof(sro6)); 1751 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1752 sro6.ro_dst.sin6_family = AF_INET6; 1753 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1754 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1755 rtalloc_ign((struct route *)&sro6, 0); 1756 } 1757 if (sro6.ro_rt != NULL) { 1758 ifp = sro6.ro_rt->rt_ifp; 1759 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1760 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1761 else 1762 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1763 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1764 1765 /* Report additional interface capabilities. */ 1766 if (flags != NULL) { 1767 if (ifp->if_capenable & IFCAP_TSO6 && 1768 ifp->if_hwassist & CSUM_TSO) 1769 *flags |= CSUM_TSO; 1770 } 1771 RTFREE(sro6.ro_rt); 1772 } 1773 1774 return (maxmtu); 1775 } 1776 #endif /* INET6 */ 1777 1778 #ifdef IPSEC 1779 /* compute ESP/AH header size for TCP, including outer IP header. */ 1780 size_t 1781 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1782 { 1783 struct inpcb *inp; 1784 struct mbuf *m; 1785 size_t hdrsiz; 1786 struct ip *ip; 1787 #ifdef INET6 1788 struct ip6_hdr *ip6; 1789 #endif 1790 struct tcphdr *th; 1791 1792 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1793 return (0); 1794 MGETHDR(m, M_DONTWAIT, MT_DATA); 1795 if (!m) 1796 return (0); 1797 1798 #ifdef INET6 1799 if ((inp->inp_vflag & INP_IPV6) != 0) { 1800 ip6 = mtod(m, struct ip6_hdr *); 1801 th = (struct tcphdr *)(ip6 + 1); 1802 m->m_pkthdr.len = m->m_len = 1803 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1804 tcpip_fillheaders(inp, ip6, th); 1805 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1806 } else 1807 #endif /* INET6 */ 1808 { 1809 ip = mtod(m, struct ip *); 1810 th = (struct tcphdr *)(ip + 1); 1811 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1812 tcpip_fillheaders(inp, ip, th); 1813 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1814 } 1815 1816 m_free(m); 1817 return (hdrsiz); 1818 } 1819 #endif /* IPSEC */ 1820 1821 /* 1822 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1823 * 1824 * This code attempts to calculate the bandwidth-delay product as a 1825 * means of determining the optimal window size to maximize bandwidth, 1826 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1827 * routers. This code also does a fairly good job keeping RTTs in check 1828 * across slow links like modems. We implement an algorithm which is very 1829 * similar (but not meant to be) TCP/Vegas. The code operates on the 1830 * transmitter side of a TCP connection and so only effects the transmit 1831 * side of the connection. 1832 * 1833 * BACKGROUND: TCP makes no provision for the management of buffer space 1834 * at the end points or at the intermediate routers and switches. A TCP 1835 * stream, whether using NewReno or not, will eventually buffer as 1836 * many packets as it is able and the only reason this typically works is 1837 * due to the fairly small default buffers made available for a connection 1838 * (typicaly 16K or 32K). As machines use larger windows and/or window 1839 * scaling it is now fairly easy for even a single TCP connection to blow-out 1840 * all available buffer space not only on the local interface, but on 1841 * intermediate routers and switches as well. NewReno makes a misguided 1842 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1843 * then backing off, then steadily increasing the window again until another 1844 * failure occurs, ad-infinitum. This results in terrible oscillation that 1845 * is only made worse as network loads increase and the idea of intentionally 1846 * blowing out network buffers is, frankly, a terrible way to manage network 1847 * resources. 1848 * 1849 * It is far better to limit the transmit window prior to the failure 1850 * condition being achieved. There are two general ways to do this: First 1851 * you can 'scan' through different transmit window sizes and locate the 1852 * point where the RTT stops increasing, indicating that you have filled the 1853 * pipe, then scan backwards until you note that RTT stops decreasing, then 1854 * repeat ad-infinitum. This method works in principle but has severe 1855 * implementation issues due to RTT variances, timer granularity, and 1856 * instability in the algorithm which can lead to many false positives and 1857 * create oscillations as well as interact badly with other TCP streams 1858 * implementing the same algorithm. 1859 * 1860 * The second method is to limit the window to the bandwidth delay product 1861 * of the link. This is the method we implement. RTT variances and our 1862 * own manipulation of the congestion window, bwnd, can potentially 1863 * destabilize the algorithm. For this reason we have to stabilize the 1864 * elements used to calculate the window. We do this by using the minimum 1865 * observed RTT, the long term average of the observed bandwidth, and 1866 * by adding two segments worth of slop. It isn't perfect but it is able 1867 * to react to changing conditions and gives us a very stable basis on 1868 * which to extend the algorithm. 1869 */ 1870 void 1871 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1872 { 1873 u_long bw; 1874 u_long bwnd; 1875 int save_ticks; 1876 1877 INP_WLOCK_ASSERT(tp->t_inpcb); 1878 1879 /* 1880 * If inflight_enable is disabled in the middle of a tcp connection, 1881 * make sure snd_bwnd is effectively disabled. 1882 */ 1883 if (V_tcp_inflight_enable == 0 || 1884 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1885 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1886 tp->snd_bandwidth = 0; 1887 return; 1888 } 1889 1890 /* 1891 * Figure out the bandwidth. Due to the tick granularity this 1892 * is a very rough number and it MUST be averaged over a fairly 1893 * long period of time. XXX we need to take into account a link 1894 * that is not using all available bandwidth, but for now our 1895 * slop will ramp us up if this case occurs and the bandwidth later 1896 * increases. 1897 * 1898 * Note: if ticks rollover 'bw' may wind up negative. We must 1899 * effectively reset t_bw_rtttime for this case. 1900 */ 1901 save_ticks = ticks; 1902 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1903 return; 1904 1905 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1906 (save_ticks - tp->t_bw_rtttime); 1907 tp->t_bw_rtttime = save_ticks; 1908 tp->t_bw_rtseq = ack_seq; 1909 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1910 return; 1911 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1912 1913 tp->snd_bandwidth = bw; 1914 1915 /* 1916 * Calculate the semi-static bandwidth delay product, plus two maximal 1917 * segments. The additional slop puts us squarely in the sweet 1918 * spot and also handles the bandwidth run-up case and stabilization. 1919 * Without the slop we could be locking ourselves into a lower 1920 * bandwidth. 1921 * 1922 * Situations Handled: 1923 * (1) Prevents over-queueing of packets on LANs, especially on 1924 * high speed LANs, allowing larger TCP buffers to be 1925 * specified, and also does a good job preventing 1926 * over-queueing of packets over choke points like modems 1927 * (at least for the transmit side). 1928 * 1929 * (2) Is able to handle changing network loads (bandwidth 1930 * drops so bwnd drops, bandwidth increases so bwnd 1931 * increases). 1932 * 1933 * (3) Theoretically should stabilize in the face of multiple 1934 * connections implementing the same algorithm (this may need 1935 * a little work). 1936 * 1937 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1938 * be adjusted with a sysctl but typically only needs to be 1939 * on very slow connections. A value no smaller then 5 1940 * should be used, but only reduce this default if you have 1941 * no other choice. 1942 */ 1943 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1944 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1945 #undef USERTT 1946 1947 if (tcp_inflight_debug > 0) { 1948 static int ltime; 1949 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1950 ltime = ticks; 1951 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1952 tp, 1953 bw, 1954 tp->t_rttbest, 1955 tp->t_srtt, 1956 bwnd 1957 ); 1958 } 1959 } 1960 if ((long)bwnd < V_tcp_inflight_min) 1961 bwnd = V_tcp_inflight_min; 1962 if (bwnd > V_tcp_inflight_max) 1963 bwnd = V_tcp_inflight_max; 1964 if ((long)bwnd < tp->t_maxseg * 2) 1965 bwnd = tp->t_maxseg * 2; 1966 tp->snd_bwnd = bwnd; 1967 } 1968 1969 #ifdef TCP_SIGNATURE 1970 /* 1971 * Callback function invoked by m_apply() to digest TCP segment data 1972 * contained within an mbuf chain. 1973 */ 1974 static int 1975 tcp_signature_apply(void *fstate, void *data, u_int len) 1976 { 1977 1978 MD5Update(fstate, (u_char *)data, len); 1979 return (0); 1980 } 1981 1982 /* 1983 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1984 * 1985 * Parameters: 1986 * m pointer to head of mbuf chain 1987 * _unused 1988 * len length of TCP segment data, excluding options 1989 * optlen length of TCP segment options 1990 * buf pointer to storage for computed MD5 digest 1991 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1992 * 1993 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1994 * When called from tcp_input(), we can be sure that th_sum has been 1995 * zeroed out and verified already. 1996 * 1997 * Return 0 if successful, otherwise return -1. 1998 * 1999 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2000 * search with the destination IP address, and a 'magic SPI' to be 2001 * determined by the application. This is hardcoded elsewhere to 1179 2002 * right now. Another branch of this code exists which uses the SPD to 2003 * specify per-application flows but it is unstable. 2004 */ 2005 int 2006 tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2007 u_char *buf, u_int direction) 2008 { 2009 union sockaddr_union dst; 2010 struct ippseudo ippseudo; 2011 MD5_CTX ctx; 2012 int doff; 2013 struct ip *ip; 2014 struct ipovly *ipovly; 2015 struct secasvar *sav; 2016 struct tcphdr *th; 2017 #ifdef INET6 2018 struct ip6_hdr *ip6; 2019 struct in6_addr in6; 2020 char ip6buf[INET6_ADDRSTRLEN]; 2021 uint32_t plen; 2022 uint16_t nhdr; 2023 #endif 2024 u_short savecsum; 2025 2026 KASSERT(m != NULL, ("NULL mbuf chain")); 2027 KASSERT(buf != NULL, ("NULL signature pointer")); 2028 2029 /* Extract the destination from the IP header in the mbuf. */ 2030 bzero(&dst, sizeof(union sockaddr_union)); 2031 ip = mtod(m, struct ip *); 2032 #ifdef INET6 2033 ip6 = NULL; /* Make the compiler happy. */ 2034 #endif 2035 switch (ip->ip_v) { 2036 case IPVERSION: 2037 dst.sa.sa_len = sizeof(struct sockaddr_in); 2038 dst.sa.sa_family = AF_INET; 2039 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2040 ip->ip_src : ip->ip_dst; 2041 break; 2042 #ifdef INET6 2043 case (IPV6_VERSION >> 4): 2044 ip6 = mtod(m, struct ip6_hdr *); 2045 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2046 dst.sa.sa_family = AF_INET6; 2047 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2048 ip6->ip6_src : ip6->ip6_dst; 2049 break; 2050 #endif 2051 default: 2052 return (EINVAL); 2053 /* NOTREACHED */ 2054 break; 2055 } 2056 2057 /* Look up an SADB entry which matches the address of the peer. */ 2058 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2059 if (sav == NULL) { 2060 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2061 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2062 #ifdef INET6 2063 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2064 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2065 #endif 2066 "(unsupported)")); 2067 return (EINVAL); 2068 } 2069 2070 MD5Init(&ctx); 2071 /* 2072 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2073 * 2074 * XXX The ippseudo header MUST be digested in network byte order, 2075 * or else we'll fail the regression test. Assume all fields we've 2076 * been doing arithmetic on have been in host byte order. 2077 * XXX One cannot depend on ipovly->ih_len here. When called from 2078 * tcp_output(), the underlying ip_len member has not yet been set. 2079 */ 2080 switch (ip->ip_v) { 2081 case IPVERSION: 2082 ipovly = (struct ipovly *)ip; 2083 ippseudo.ippseudo_src = ipovly->ih_src; 2084 ippseudo.ippseudo_dst = ipovly->ih_dst; 2085 ippseudo.ippseudo_pad = 0; 2086 ippseudo.ippseudo_p = IPPROTO_TCP; 2087 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2088 optlen); 2089 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2090 2091 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2092 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2093 break; 2094 #ifdef INET6 2095 /* 2096 * RFC 2385, 2.0 Proposal 2097 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2098 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2099 * extended next header value (to form 32 bits), and 32-bit segment 2100 * length. 2101 * Note: Upper-Layer Packet Length comes before Next Header. 2102 */ 2103 case (IPV6_VERSION >> 4): 2104 in6 = ip6->ip6_src; 2105 in6_clearscope(&in6); 2106 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2107 in6 = ip6->ip6_dst; 2108 in6_clearscope(&in6); 2109 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2110 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2111 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2112 nhdr = 0; 2113 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2114 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2115 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2116 nhdr = IPPROTO_TCP; 2117 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2118 2119 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2120 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2121 break; 2122 #endif 2123 default: 2124 return (EINVAL); 2125 /* NOTREACHED */ 2126 break; 2127 } 2128 2129 2130 /* 2131 * Step 2: Update MD5 hash with TCP header, excluding options. 2132 * The TCP checksum must be set to zero. 2133 */ 2134 savecsum = th->th_sum; 2135 th->th_sum = 0; 2136 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2137 th->th_sum = savecsum; 2138 2139 /* 2140 * Step 3: Update MD5 hash with TCP segment data. 2141 * Use m_apply() to avoid an early m_pullup(). 2142 */ 2143 if (len > 0) 2144 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2145 2146 /* 2147 * Step 4: Update MD5 hash with shared secret. 2148 */ 2149 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2150 MD5Final(buf, &ctx); 2151 2152 key_sa_recordxfer(sav, m); 2153 KEY_FREESAV(&sav); 2154 return (0); 2155 } 2156 #endif /* TCP_SIGNATURE */ 2157 2158 static int 2159 sysctl_drop(SYSCTL_HANDLER_ARGS) 2160 { 2161 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2162 struct sockaddr_storage addrs[2]; 2163 struct inpcb *inp; 2164 struct tcpcb *tp; 2165 struct tcptw *tw; 2166 struct sockaddr_in *fin, *lin; 2167 #ifdef INET6 2168 struct sockaddr_in6 *fin6, *lin6; 2169 #endif 2170 int error; 2171 2172 inp = NULL; 2173 fin = lin = NULL; 2174 #ifdef INET6 2175 fin6 = lin6 = NULL; 2176 #endif 2177 error = 0; 2178 2179 if (req->oldptr != NULL || req->oldlen != 0) 2180 return (EINVAL); 2181 if (req->newptr == NULL) 2182 return (EPERM); 2183 if (req->newlen < sizeof(addrs)) 2184 return (ENOMEM); 2185 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2186 if (error) 2187 return (error); 2188 2189 switch (addrs[0].ss_family) { 2190 #ifdef INET6 2191 case AF_INET6: 2192 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2193 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2194 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2195 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2196 return (EINVAL); 2197 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2198 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2199 return (EINVAL); 2200 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2201 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2202 fin = (struct sockaddr_in *)&addrs[0]; 2203 lin = (struct sockaddr_in *)&addrs[1]; 2204 break; 2205 } 2206 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2207 if (error) 2208 return (error); 2209 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2210 if (error) 2211 return (error); 2212 break; 2213 #endif 2214 case AF_INET: 2215 fin = (struct sockaddr_in *)&addrs[0]; 2216 lin = (struct sockaddr_in *)&addrs[1]; 2217 if (fin->sin_len != sizeof(struct sockaddr_in) || 2218 lin->sin_len != sizeof(struct sockaddr_in)) 2219 return (EINVAL); 2220 break; 2221 default: 2222 return (EINVAL); 2223 } 2224 INP_INFO_WLOCK(&V_tcbinfo); 2225 switch (addrs[0].ss_family) { 2226 #ifdef INET6 2227 case AF_INET6: 2228 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2229 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2230 NULL); 2231 break; 2232 #endif 2233 case AF_INET: 2234 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2235 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2236 break; 2237 } 2238 if (inp != NULL) { 2239 INP_WLOCK(inp); 2240 if (inp->inp_flags & INP_TIMEWAIT) { 2241 /* 2242 * XXXRW: There currently exists a state where an 2243 * inpcb is present, but its timewait state has been 2244 * discarded. For now, don't allow dropping of this 2245 * type of inpcb. 2246 */ 2247 tw = intotw(inp); 2248 if (tw != NULL) 2249 tcp_twclose(tw, 0); 2250 else 2251 INP_WUNLOCK(inp); 2252 } else if (!(inp->inp_flags & INP_DROPPED) && 2253 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2254 tp = intotcpcb(inp); 2255 tp = tcp_drop(tp, ECONNABORTED); 2256 if (tp != NULL) 2257 INP_WUNLOCK(inp); 2258 } else 2259 INP_WUNLOCK(inp); 2260 } else 2261 error = ESRCH; 2262 INP_INFO_WUNLOCK(&V_tcbinfo); 2263 return (error); 2264 } 2265 2266 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2267 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2268 0, sysctl_drop, "", "Drop TCP connection"); 2269 2270 /* 2271 * Generate a standardized TCP log line for use throughout the 2272 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2273 * allow use in the interrupt context. 2274 * 2275 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2276 * NB: The function may return NULL if memory allocation failed. 2277 * 2278 * Due to header inclusion and ordering limitations the struct ip 2279 * and ip6_hdr pointers have to be passed as void pointers. 2280 */ 2281 char * 2282 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2283 const void *ip6hdr) 2284 { 2285 char *s, *sp; 2286 size_t size; 2287 struct ip *ip; 2288 #ifdef INET6 2289 const struct ip6_hdr *ip6; 2290 2291 ip6 = (const struct ip6_hdr *)ip6hdr; 2292 #endif /* INET6 */ 2293 ip = (struct ip *)ip4hdr; 2294 2295 /* 2296 * The log line looks like this: 2297 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2298 */ 2299 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2300 sizeof(PRINT_TH_FLAGS) + 1 + 2301 #ifdef INET6 2302 2 * INET6_ADDRSTRLEN; 2303 #else 2304 2 * INET_ADDRSTRLEN; 2305 #endif /* INET6 */ 2306 2307 /* Is logging enabled? */ 2308 if (tcp_log_debug == 0 && tcp_log_in_vain == 0) 2309 return (NULL); 2310 2311 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2312 if (s == NULL) 2313 return (NULL); 2314 2315 strcat(s, "TCP: ["); 2316 sp = s + strlen(s); 2317 2318 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2319 inet_ntoa_r(inc->inc_faddr, sp); 2320 sp = s + strlen(s); 2321 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2322 sp = s + strlen(s); 2323 inet_ntoa_r(inc->inc_laddr, sp); 2324 sp = s + strlen(s); 2325 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2326 #ifdef INET6 2327 } else if (inc) { 2328 ip6_sprintf(sp, &inc->inc6_faddr); 2329 sp = s + strlen(s); 2330 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2331 sp = s + strlen(s); 2332 ip6_sprintf(sp, &inc->inc6_laddr); 2333 sp = s + strlen(s); 2334 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2335 } else if (ip6 && th) { 2336 ip6_sprintf(sp, &ip6->ip6_src); 2337 sp = s + strlen(s); 2338 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2339 sp = s + strlen(s); 2340 ip6_sprintf(sp, &ip6->ip6_dst); 2341 sp = s + strlen(s); 2342 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2343 #endif /* INET6 */ 2344 } else if (ip && th) { 2345 inet_ntoa_r(ip->ip_src, sp); 2346 sp = s + strlen(s); 2347 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2348 sp = s + strlen(s); 2349 inet_ntoa_r(ip->ip_dst, sp); 2350 sp = s + strlen(s); 2351 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2352 } else { 2353 free(s, M_TCPLOG); 2354 return (NULL); 2355 } 2356 sp = s + strlen(s); 2357 if (th) 2358 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2359 if (*(s + size - 1) != '\0') 2360 panic("%s: string too long", __func__); 2361 return (s); 2362 } 2363