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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 34 * $FreeBSD$ 35 */ 36 37 #include "opt_compat.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_tcpdebug.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/callout.h> 45 #include <sys/kernel.h> 46 #include <sys/sysctl.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #ifdef INET6 50 #include <sys/domain.h> 51 #endif 52 #include <sys/proc.h> 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/protosw.h> 56 57 #include <vm/vm_zone.h> 58 59 #include <net/route.h> 60 #include <net/if.h> 61 62 #define _IP_VHL 63 #include <netinet/in.h> 64 #include <netinet/in_systm.h> 65 #include <netinet/ip.h> 66 #ifdef INET6 67 #include <netinet/ip6.h> 68 #endif 69 #include <netinet/in_pcb.h> 70 #ifdef INET6 71 #include <netinet6/in6_pcb.h> 72 #endif 73 #include <netinet/in_var.h> 74 #include <netinet/ip_var.h> 75 #ifdef INET6 76 #include <netinet6/ip6_var.h> 77 #endif 78 #include <netinet/tcp.h> 79 #include <netinet/tcp_fsm.h> 80 #include <netinet/tcp_seq.h> 81 #include <netinet/tcp_timer.h> 82 #include <netinet/tcp_var.h> 83 #ifdef INET6 84 #include <netinet6/tcp6_var.h> 85 #endif 86 #include <netinet/tcpip.h> 87 #ifdef TCPDEBUG 88 #include <netinet/tcp_debug.h> 89 #endif 90 #include <netinet6/ip6protosw.h> 91 92 #ifdef IPSEC 93 #include <netinet6/ipsec.h> 94 #ifdef INET6 95 #include <netinet6/ipsec6.h> 96 #endif 97 #endif /*IPSEC*/ 98 99 #include <machine/in_cksum.h> 100 101 int tcp_mssdflt = TCP_MSS; 102 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 103 &tcp_mssdflt , 0, "Default TCP Maximum Segment Size"); 104 105 #ifdef INET6 106 int tcp_v6mssdflt = TCP6_MSS; 107 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 108 CTLFLAG_RW, &tcp_v6mssdflt , 0, 109 "Default TCP Maximum Segment Size for IPv6"); 110 #endif 111 112 #if 0 113 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 114 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 115 &tcp_rttdflt , 0, "Default maximum TCP Round Trip Time"); 116 #endif 117 118 static int tcp_do_rfc1323 = 1; 119 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 120 &tcp_do_rfc1323 , 0, "Enable rfc1323 (high performance TCP) extensions"); 121 122 static int tcp_do_rfc1644 = 0; 123 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW, 124 &tcp_do_rfc1644 , 0, "Enable rfc1644 (TTCP) extensions"); 125 126 static int tcp_tcbhashsize = 0; 127 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 128 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 129 130 static int do_tcpdrain = 1; 131 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 132 "Enable tcp_drain routine for extra help when low on mbufs"); 133 134 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 135 &tcbinfo.ipi_count, 0, "Number of active PCBs"); 136 137 static int icmp_may_rst = 1; 138 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 139 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 140 141 static void tcp_cleartaocache __P((void)); 142 static void tcp_notify __P((struct inpcb *, int)); 143 144 /* 145 * Target size of TCP PCB hash tables. Must be a power of two. 146 * 147 * Note that this can be overridden by the kernel environment 148 * variable net.inet.tcp.tcbhashsize 149 */ 150 #ifndef TCBHASHSIZE 151 #define TCBHASHSIZE 512 152 #endif 153 154 /* 155 * This is the actual shape of what we allocate using the zone 156 * allocator. Doing it this way allows us to protect both structures 157 * using the same generation count, and also eliminates the overhead 158 * of allocating tcpcbs separately. By hiding the structure here, 159 * we avoid changing most of the rest of the code (although it needs 160 * to be changed, eventually, for greater efficiency). 161 */ 162 #define ALIGNMENT 32 163 #define ALIGNM1 (ALIGNMENT - 1) 164 struct inp_tp { 165 union { 166 struct inpcb inp; 167 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 168 } inp_tp_u; 169 struct tcpcb tcb; 170 struct callout inp_tp_rexmt, inp_tp_persist, inp_tp_keep, inp_tp_2msl; 171 struct callout inp_tp_delack; 172 }; 173 #undef ALIGNMENT 174 #undef ALIGNM1 175 176 /* 177 * Tcp initialization 178 */ 179 void 180 tcp_init() 181 { 182 int hashsize; 183 184 tcp_iss = arc4random(); /* wrong, but better than a constant */ 185 tcp_ccgen = 1; 186 tcp_cleartaocache(); 187 188 tcp_delacktime = TCPTV_DELACK; 189 tcp_keepinit = TCPTV_KEEP_INIT; 190 tcp_keepidle = TCPTV_KEEP_IDLE; 191 tcp_keepintvl = TCPTV_KEEPINTVL; 192 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 193 tcp_msl = TCPTV_MSL; 194 195 LIST_INIT(&tcb); 196 tcbinfo.listhead = &tcb; 197 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", TCBHASHSIZE, hashsize); 198 if (!powerof2(hashsize)) { 199 printf("WARNING: TCB hash size not a power of 2\n"); 200 hashsize = 512; /* safe default */ 201 } 202 tcp_tcbhashsize = hashsize; 203 tcbinfo.hashbase = hashinit(hashsize, M_PCB, &tcbinfo.hashmask); 204 tcbinfo.porthashbase = hashinit(hashsize, M_PCB, 205 &tcbinfo.porthashmask); 206 tcbinfo.ipi_zone = zinit("tcpcb", sizeof(struct inp_tp), maxsockets, 207 ZONE_INTERRUPT, 0); 208 #ifdef INET6 209 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 210 #else /* INET6 */ 211 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 212 #endif /* INET6 */ 213 if (max_protohdr < TCP_MINPROTOHDR) 214 max_protohdr = TCP_MINPROTOHDR; 215 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 216 panic("tcp_init"); 217 #undef TCP_MINPROTOHDR 218 } 219 220 /* 221 * Create template to be used to send tcp packets on a connection. 222 * Call after host entry created, allocates an mbuf and fills 223 * in a skeletal tcp/ip header, minimizing the amount of work 224 * necessary when the connection is used. 225 */ 226 struct tcptemp * 227 tcp_template(tp) 228 struct tcpcb *tp; 229 { 230 register struct inpcb *inp = tp->t_inpcb; 231 register struct mbuf *m; 232 register struct tcptemp *n; 233 234 if ((n = tp->t_template) == 0) { 235 m = m_get(M_DONTWAIT, MT_HEADER); 236 if (m == NULL) 237 return (0); 238 m->m_len = sizeof (struct tcptemp); 239 n = mtod(m, struct tcptemp *); 240 } 241 #ifdef INET6 242 if ((inp->inp_vflag & INP_IPV6) != 0) { 243 register struct ip6_hdr *ip6; 244 245 ip6 = (struct ip6_hdr *)n->tt_ipgen; 246 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 247 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 248 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 249 (IPV6_VERSION & IPV6_VERSION_MASK); 250 ip6->ip6_nxt = IPPROTO_TCP; 251 ip6->ip6_plen = sizeof(struct tcphdr); 252 ip6->ip6_src = inp->in6p_laddr; 253 ip6->ip6_dst = inp->in6p_faddr; 254 n->tt_t.th_sum = 0; 255 } else 256 #endif 257 { 258 struct ip *ip = (struct ip *)n->tt_ipgen; 259 260 bzero(ip, sizeof(struct ip)); /* XXX overkill? */ 261 ip->ip_vhl = IP_VHL_BORING; 262 ip->ip_p = IPPROTO_TCP; 263 ip->ip_src = inp->inp_laddr; 264 ip->ip_dst = inp->inp_faddr; 265 n->tt_t.th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 266 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 267 } 268 n->tt_t.th_sport = inp->inp_lport; 269 n->tt_t.th_dport = inp->inp_fport; 270 n->tt_t.th_seq = 0; 271 n->tt_t.th_ack = 0; 272 n->tt_t.th_x2 = 0; 273 n->tt_t.th_off = 5; 274 n->tt_t.th_flags = 0; 275 n->tt_t.th_win = 0; 276 n->tt_t.th_urp = 0; 277 return (n); 278 } 279 280 /* 281 * Send a single message to the TCP at address specified by 282 * the given TCP/IP header. If m == 0, then we make a copy 283 * of the tcpiphdr at ti and send directly to the addressed host. 284 * This is used to force keep alive messages out using the TCP 285 * template for a connection tp->t_template. If flags are given 286 * then we send a message back to the TCP which originated the 287 * segment ti, and discard the mbuf containing it and any other 288 * attached mbufs. 289 * 290 * In any case the ack and sequence number of the transmitted 291 * segment are as specified by the parameters. 292 * 293 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 294 */ 295 void 296 tcp_respond(tp, ipgen, th, m, ack, seq, flags) 297 struct tcpcb *tp; 298 void *ipgen; 299 register struct tcphdr *th; 300 register struct mbuf *m; 301 tcp_seq ack, seq; 302 int flags; 303 { 304 register int tlen; 305 int win = 0; 306 struct route *ro = 0; 307 struct route sro; 308 struct ip *ip; 309 struct tcphdr *nth; 310 #ifdef INET6 311 struct route_in6 *ro6 = 0; 312 struct route_in6 sro6; 313 struct ip6_hdr *ip6; 314 int isipv6; 315 #endif /* INET6 */ 316 int ipflags = 0; 317 318 #ifdef INET6 319 isipv6 = IP_VHL_V(((struct ip *)ipgen)->ip_vhl) == 6; 320 ip6 = ipgen; 321 #endif /* INET6 */ 322 ip = ipgen; 323 324 if (tp) { 325 if (!(flags & TH_RST)) { 326 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 327 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 328 win = (long)TCP_MAXWIN << tp->rcv_scale; 329 } 330 #ifdef INET6 331 if (isipv6) 332 ro6 = &tp->t_inpcb->in6p_route; 333 else 334 #endif /* INET6 */ 335 ro = &tp->t_inpcb->inp_route; 336 } else { 337 #ifdef INET6 338 if (isipv6) { 339 ro6 = &sro6; 340 bzero(ro6, sizeof *ro6); 341 } else 342 #endif /* INET6 */ 343 { 344 ro = &sro; 345 bzero(ro, sizeof *ro); 346 } 347 } 348 if (m == 0) { 349 m = m_gethdr(M_DONTWAIT, MT_HEADER); 350 if (m == NULL) 351 return; 352 #ifdef TCP_COMPAT_42 353 tlen = 1; 354 #else 355 tlen = 0; 356 #endif 357 m->m_data += max_linkhdr; 358 #ifdef INET6 359 if (isipv6) { 360 bcopy((caddr_t)ip6, mtod(m, caddr_t), 361 sizeof(struct ip6_hdr)); 362 ip6 = mtod(m, struct ip6_hdr *); 363 nth = (struct tcphdr *)(ip6 + 1); 364 } else 365 #endif /* INET6 */ 366 { 367 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 368 ip = mtod(m, struct ip *); 369 nth = (struct tcphdr *)(ip + 1); 370 } 371 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 372 flags = TH_ACK; 373 } else { 374 m_freem(m->m_next); 375 m->m_next = 0; 376 m->m_data = (caddr_t)ipgen; 377 /* m_len is set later */ 378 tlen = 0; 379 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 380 #ifdef INET6 381 if (isipv6) { 382 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 383 nth = (struct tcphdr *)(ip6 + 1); 384 } else 385 #endif /* INET6 */ 386 { 387 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 388 nth = (struct tcphdr *)(ip + 1); 389 } 390 if (th != nth) { 391 /* 392 * this is usually a case when an extension header 393 * exists between the IPv6 header and the 394 * TCP header. 395 */ 396 nth->th_sport = th->th_sport; 397 nth->th_dport = th->th_dport; 398 } 399 xchg(nth->th_dport, nth->th_sport, n_short); 400 #undef xchg 401 } 402 #ifdef INET6 403 if (isipv6) { 404 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 405 tlen)); 406 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 407 } else 408 #endif 409 { 410 tlen += sizeof (struct tcpiphdr); 411 ip->ip_len = tlen; 412 ip->ip_ttl = ip_defttl; 413 } 414 m->m_len = tlen; 415 m->m_pkthdr.len = tlen; 416 m->m_pkthdr.rcvif = (struct ifnet *) 0; 417 nth->th_seq = htonl(seq); 418 nth->th_ack = htonl(ack); 419 nth->th_x2 = 0; 420 nth->th_off = sizeof (struct tcphdr) >> 2; 421 nth->th_flags = flags; 422 if (tp) 423 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 424 else 425 nth->th_win = htons((u_short)win); 426 nth->th_urp = 0; 427 #ifdef INET6 428 if (isipv6) { 429 nth->th_sum = 0; 430 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 431 sizeof(struct ip6_hdr), 432 tlen - sizeof(struct ip6_hdr)); 433 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 434 ro6 && ro6->ro_rt ? 435 ro6->ro_rt->rt_ifp : 436 NULL); 437 } else 438 #endif /* INET6 */ 439 { 440 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 441 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 442 m->m_pkthdr.csum_flags = CSUM_TCP; 443 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 444 } 445 #ifdef TCPDEBUG 446 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 447 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 448 #endif 449 #ifdef IPSEC 450 ipsec_setsocket(m, tp ? tp->t_inpcb->inp_socket : NULL); 451 #endif 452 #ifdef INET6 453 if (isipv6) { 454 (void)ip6_output(m, NULL, ro6, ipflags, NULL, NULL); 455 if (ro6 == &sro6 && ro6->ro_rt) { 456 RTFREE(ro6->ro_rt); 457 ro6->ro_rt = NULL; 458 } 459 } else 460 #endif /* INET6 */ 461 { 462 (void) ip_output(m, NULL, ro, ipflags, NULL); 463 if (ro == &sro && ro->ro_rt) { 464 RTFREE(ro->ro_rt); 465 ro->ro_rt = NULL; 466 } 467 } 468 } 469 470 /* 471 * Create a new TCP control block, making an 472 * empty reassembly queue and hooking it to the argument 473 * protocol control block. The `inp' parameter must have 474 * come from the zone allocator set up in tcp_init(). 475 */ 476 struct tcpcb * 477 tcp_newtcpcb(inp) 478 struct inpcb *inp; 479 { 480 struct inp_tp *it; 481 register struct tcpcb *tp; 482 #ifdef INET6 483 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 484 #endif /* INET6 */ 485 486 it = (struct inp_tp *)inp; 487 tp = &it->tcb; 488 bzero((char *) tp, sizeof(struct tcpcb)); 489 LIST_INIT(&tp->t_segq); 490 tp->t_maxseg = tp->t_maxopd = 491 #ifdef INET6 492 isipv6 ? tcp_v6mssdflt : 493 #endif /* INET6 */ 494 tcp_mssdflt; 495 496 /* Set up our timeouts. */ 497 callout_init(tp->tt_rexmt = &it->inp_tp_rexmt, 0); 498 callout_init(tp->tt_persist = &it->inp_tp_persist, 0); 499 callout_init(tp->tt_keep = &it->inp_tp_keep, 0); 500 callout_init(tp->tt_2msl = &it->inp_tp_2msl, 0); 501 callout_init(tp->tt_delack = &it->inp_tp_delack, 0); 502 503 if (tcp_do_rfc1323) 504 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 505 if (tcp_do_rfc1644) 506 tp->t_flags |= TF_REQ_CC; 507 tp->t_inpcb = inp; /* XXX */ 508 /* 509 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 510 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 511 * reasonable initial retransmit time. 512 */ 513 tp->t_srtt = TCPTV_SRTTBASE; 514 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 515 tp->t_rttmin = TCPTV_MIN; 516 tp->t_rxtcur = TCPTV_RTOBASE; 517 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 518 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 519 tp->t_rcvtime = ticks; 520 /* 521 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 522 * because the socket may be bound to an IPv6 wildcard address, 523 * which may match an IPv4-mapped IPv6 address. 524 */ 525 inp->inp_ip_ttl = ip_defttl; 526 inp->inp_ppcb = (caddr_t)tp; 527 return (tp); /* XXX */ 528 } 529 530 /* 531 * Drop a TCP connection, reporting 532 * the specified error. If connection is synchronized, 533 * then send a RST to peer. 534 */ 535 struct tcpcb * 536 tcp_drop(tp, errno) 537 register struct tcpcb *tp; 538 int errno; 539 { 540 struct socket *so = tp->t_inpcb->inp_socket; 541 542 if (TCPS_HAVERCVDSYN(tp->t_state)) { 543 tp->t_state = TCPS_CLOSED; 544 (void) tcp_output(tp); 545 tcpstat.tcps_drops++; 546 } else 547 tcpstat.tcps_conndrops++; 548 if (errno == ETIMEDOUT && tp->t_softerror) 549 errno = tp->t_softerror; 550 so->so_error = errno; 551 return (tcp_close(tp)); 552 } 553 554 /* 555 * Close a TCP control block: 556 * discard all space held by the tcp 557 * discard internet protocol block 558 * wake up any sleepers 559 */ 560 struct tcpcb * 561 tcp_close(tp) 562 register struct tcpcb *tp; 563 { 564 register struct tseg_qent *q; 565 struct inpcb *inp = tp->t_inpcb; 566 struct socket *so = inp->inp_socket; 567 #ifdef INET6 568 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 569 #endif /* INET6 */ 570 register struct rtentry *rt; 571 int dosavessthresh; 572 573 /* 574 * Make sure that all of our timers are stopped before we 575 * delete the PCB. 576 */ 577 callout_stop(tp->tt_rexmt); 578 callout_stop(tp->tt_persist); 579 callout_stop(tp->tt_keep); 580 callout_stop(tp->tt_2msl); 581 callout_stop(tp->tt_delack); 582 583 /* 584 * If we got enough samples through the srtt filter, 585 * save the rtt and rttvar in the routing entry. 586 * 'Enough' is arbitrarily defined as the 16 samples. 587 * 16 samples is enough for the srtt filter to converge 588 * to within 5% of the correct value; fewer samples and 589 * we could save a very bogus rtt. 590 * 591 * Don't update the default route's characteristics and don't 592 * update anything that the user "locked". 593 */ 594 if (tp->t_rttupdated >= 16) { 595 register u_long i = 0; 596 #ifdef INET6 597 if (isipv6) { 598 struct sockaddr_in6 *sin6; 599 600 if ((rt = inp->in6p_route.ro_rt) == NULL) 601 goto no_valid_rt; 602 sin6 = (struct sockaddr_in6 *)rt_key(rt); 603 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 604 goto no_valid_rt; 605 } 606 else 607 #endif /* INET6 */ 608 if ((rt = inp->inp_route.ro_rt) == NULL || 609 ((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr 610 == INADDR_ANY) 611 goto no_valid_rt; 612 613 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 614 i = tp->t_srtt * 615 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 616 if (rt->rt_rmx.rmx_rtt && i) 617 /* 618 * filter this update to half the old & half 619 * the new values, converting scale. 620 * See route.h and tcp_var.h for a 621 * description of the scaling constants. 622 */ 623 rt->rt_rmx.rmx_rtt = 624 (rt->rt_rmx.rmx_rtt + i) / 2; 625 else 626 rt->rt_rmx.rmx_rtt = i; 627 tcpstat.tcps_cachedrtt++; 628 } 629 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 630 i = tp->t_rttvar * 631 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 632 if (rt->rt_rmx.rmx_rttvar && i) 633 rt->rt_rmx.rmx_rttvar = 634 (rt->rt_rmx.rmx_rttvar + i) / 2; 635 else 636 rt->rt_rmx.rmx_rttvar = i; 637 tcpstat.tcps_cachedrttvar++; 638 } 639 /* 640 * The old comment here said: 641 * update the pipelimit (ssthresh) if it has been updated 642 * already or if a pipesize was specified & the threshhold 643 * got below half the pipesize. I.e., wait for bad news 644 * before we start updating, then update on both good 645 * and bad news. 646 * 647 * But we want to save the ssthresh even if no pipesize is 648 * specified explicitly in the route, because such 649 * connections still have an implicit pipesize specified 650 * by the global tcp_sendspace. In the absence of a reliable 651 * way to calculate the pipesize, it will have to do. 652 */ 653 i = tp->snd_ssthresh; 654 if (rt->rt_rmx.rmx_sendpipe != 0) 655 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe / 2); 656 else 657 dosavessthresh = (i < so->so_snd.sb_hiwat / 2); 658 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 659 i != 0 && rt->rt_rmx.rmx_ssthresh != 0) 660 || dosavessthresh) { 661 /* 662 * convert the limit from user data bytes to 663 * packets then to packet data bytes. 664 */ 665 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 666 if (i < 2) 667 i = 2; 668 i *= (u_long)(tp->t_maxseg + 669 #ifdef INET6 670 (isipv6 ? sizeof (struct ip6_hdr) + 671 sizeof (struct tcphdr) : 672 #endif 673 sizeof (struct tcpiphdr) 674 #ifdef INET6 675 ) 676 #endif 677 ); 678 if (rt->rt_rmx.rmx_ssthresh) 679 rt->rt_rmx.rmx_ssthresh = 680 (rt->rt_rmx.rmx_ssthresh + i) / 2; 681 else 682 rt->rt_rmx.rmx_ssthresh = i; 683 tcpstat.tcps_cachedssthresh++; 684 } 685 } 686 rt = inp->inp_route.ro_rt; 687 if (rt) { 688 /* 689 * mark route for deletion if no information is 690 * cached. 691 */ 692 if ((tp->t_flags & TF_LQ_OVERFLOW) && 693 ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0)){ 694 if (rt->rt_rmx.rmx_rtt == 0) 695 rt->rt_flags |= RTF_DELCLONE; 696 } 697 } 698 no_valid_rt: 699 /* free the reassembly queue, if any */ 700 while((q = LIST_FIRST(&tp->t_segq)) != NULL) { 701 LIST_REMOVE(q, tqe_q); 702 m_freem(q->tqe_m); 703 FREE(q, M_TSEGQ); 704 } 705 if (tp->t_template) 706 (void) m_free(dtom(tp->t_template)); 707 inp->inp_ppcb = NULL; 708 soisdisconnected(so); 709 #ifdef INET6 710 if (INP_CHECK_SOCKAF(so, AF_INET6)) 711 in6_pcbdetach(inp); 712 else 713 #endif /* INET6 */ 714 in_pcbdetach(inp); 715 tcpstat.tcps_closed++; 716 return ((struct tcpcb *)0); 717 } 718 719 void 720 tcp_drain() 721 { 722 if (do_tcpdrain) 723 { 724 struct inpcb *inpb; 725 struct tcpcb *tcpb; 726 struct tseg_qent *te; 727 728 /* 729 * Walk the tcpbs, if existing, and flush the reassembly queue, 730 * if there is one... 731 * XXX: The "Net/3" implementation doesn't imply that the TCP 732 * reassembly queue should be flushed, but in a situation 733 * where we're really low on mbufs, this is potentially 734 * usefull. 735 */ 736 for (inpb = LIST_FIRST(tcbinfo.listhead); inpb; 737 inpb = LIST_NEXT(inpb, inp_list)) { 738 if ((tcpb = intotcpcb(inpb))) { 739 while ((te = LIST_FIRST(&tcpb->t_segq)) 740 != NULL) { 741 LIST_REMOVE(te, tqe_q); 742 m_freem(te->tqe_m); 743 FREE(te, M_TSEGQ); 744 } 745 } 746 } 747 748 } 749 } 750 751 /* 752 * Notify a tcp user of an asynchronous error; 753 * store error as soft error, but wake up user 754 * (for now, won't do anything until can select for soft error). 755 * 756 * Do not wake up user since there currently is no mechanism for 757 * reporting soft errors (yet - a kqueue filter may be added). 758 */ 759 static void 760 tcp_notify(inp, error) 761 struct inpcb *inp; 762 int error; 763 { 764 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 765 766 /* 767 * Ignore some errors if we are hooked up. 768 * If connection hasn't completed, has retransmitted several times, 769 * and receives a second error, give up now. This is better 770 * than waiting a long time to establish a connection that 771 * can never complete. 772 */ 773 if (tp->t_state == TCPS_ESTABLISHED && 774 (error == EHOSTUNREACH || error == ENETUNREACH || 775 error == EHOSTDOWN)) { 776 return; 777 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 778 tp->t_softerror) 779 tcp_drop(tp, error); 780 else 781 tp->t_softerror = error; 782 #if 0 783 wakeup((caddr_t) &so->so_timeo); 784 sorwakeup(so); 785 sowwakeup(so); 786 #endif 787 } 788 789 static int 790 tcp_pcblist(SYSCTL_HANDLER_ARGS) 791 { 792 int error, i, n, s; 793 struct inpcb *inp, **inp_list; 794 inp_gen_t gencnt; 795 struct xinpgen xig; 796 797 /* 798 * The process of preparing the TCB list is too time-consuming and 799 * resource-intensive to repeat twice on every request. 800 */ 801 if (req->oldptr == 0) { 802 n = tcbinfo.ipi_count; 803 req->oldidx = 2 * (sizeof xig) 804 + (n + n/8) * sizeof(struct xtcpcb); 805 return 0; 806 } 807 808 if (req->newptr != 0) 809 return EPERM; 810 811 /* 812 * OK, now we're committed to doing something. 813 */ 814 s = splnet(); 815 gencnt = tcbinfo.ipi_gencnt; 816 n = tcbinfo.ipi_count; 817 splx(s); 818 819 xig.xig_len = sizeof xig; 820 xig.xig_count = n; 821 xig.xig_gen = gencnt; 822 xig.xig_sogen = so_gencnt; 823 error = SYSCTL_OUT(req, &xig, sizeof xig); 824 if (error) 825 return error; 826 827 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 828 if (inp_list == 0) 829 return ENOMEM; 830 831 s = splnet(); 832 for (inp = LIST_FIRST(tcbinfo.listhead), i = 0; inp && i < n; 833 inp = LIST_NEXT(inp, inp_list)) { 834 if (inp->inp_gencnt <= gencnt && !prison_xinpcb(req->p, inp)) 835 inp_list[i++] = inp; 836 } 837 splx(s); 838 n = i; 839 840 error = 0; 841 for (i = 0; i < n; i++) { 842 inp = inp_list[i]; 843 if (inp->inp_gencnt <= gencnt) { 844 struct xtcpcb xt; 845 caddr_t inp_ppcb; 846 xt.xt_len = sizeof xt; 847 /* XXX should avoid extra copy */ 848 bcopy(inp, &xt.xt_inp, sizeof *inp); 849 inp_ppcb = inp->inp_ppcb; 850 if (inp_ppcb != NULL) 851 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 852 else 853 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 854 if (inp->inp_socket) 855 sotoxsocket(inp->inp_socket, &xt.xt_socket); 856 error = SYSCTL_OUT(req, &xt, sizeof xt); 857 } 858 } 859 if (!error) { 860 /* 861 * Give the user an updated idea of our state. 862 * If the generation differs from what we told 863 * her before, she knows that something happened 864 * while we were processing this request, and it 865 * might be necessary to retry. 866 */ 867 s = splnet(); 868 xig.xig_gen = tcbinfo.ipi_gencnt; 869 xig.xig_sogen = so_gencnt; 870 xig.xig_count = tcbinfo.ipi_count; 871 splx(s); 872 error = SYSCTL_OUT(req, &xig, sizeof xig); 873 } 874 free(inp_list, M_TEMP); 875 return error; 876 } 877 878 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 879 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 880 881 static int 882 tcp_getcred(SYSCTL_HANDLER_ARGS) 883 { 884 struct xucred xuc; 885 struct sockaddr_in addrs[2]; 886 struct inpcb *inp; 887 int error, s; 888 889 error = suser(req->p); 890 if (error) 891 return (error); 892 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 893 if (error) 894 return (error); 895 s = splnet(); 896 inp = in_pcblookup_hash(&tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 897 addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 898 if (inp == NULL || inp->inp_socket == NULL) { 899 error = ENOENT; 900 goto out; 901 } 902 bzero(&xuc, sizeof(xuc)); 903 xuc.cr_uid = inp->inp_socket->so_cred->cr_uid; 904 xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups; 905 bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups, 906 sizeof(xuc.cr_groups)); 907 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 908 out: 909 splx(s); 910 return (error); 911 } 912 913 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 914 0, 0, tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 915 916 #ifdef INET6 917 static int 918 tcp6_getcred(SYSCTL_HANDLER_ARGS) 919 { 920 struct xucred xuc; 921 struct sockaddr_in6 addrs[2]; 922 struct inpcb *inp; 923 int error, s, mapped = 0; 924 925 error = suser(req->p); 926 if (error) 927 return (error); 928 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 929 if (error) 930 return (error); 931 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 932 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 933 mapped = 1; 934 else 935 return (EINVAL); 936 } 937 s = splnet(); 938 if (mapped == 1) 939 inp = in_pcblookup_hash(&tcbinfo, 940 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 941 addrs[1].sin6_port, 942 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 943 addrs[0].sin6_port, 944 0, NULL); 945 else 946 inp = in6_pcblookup_hash(&tcbinfo, &addrs[1].sin6_addr, 947 addrs[1].sin6_port, 948 &addrs[0].sin6_addr, addrs[0].sin6_port, 949 0, NULL); 950 if (inp == NULL || inp->inp_socket == NULL) { 951 error = ENOENT; 952 goto out; 953 } 954 bzero(&xuc, sizeof(xuc)); 955 xuc.cr_uid = inp->inp_socket->so_cred->cr_uid; 956 xuc.cr_ngroups = inp->inp_socket->so_cred->cr_ngroups; 957 bcopy(inp->inp_socket->so_cred->cr_groups, xuc.cr_groups, 958 sizeof(xuc.cr_groups)); 959 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 960 out: 961 splx(s); 962 return (error); 963 } 964 965 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 966 0, 0, 967 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 968 #endif 969 970 971 void 972 tcp_ctlinput(cmd, sa, vip) 973 int cmd; 974 struct sockaddr *sa; 975 void *vip; 976 { 977 struct ip *ip = vip; 978 struct tcphdr *th; 979 void (*notify) __P((struct inpcb *, int)) = tcp_notify; 980 tcp_seq tcp_sequence = 0; 981 int tcp_seq_check = 0; 982 983 if (cmd == PRC_QUENCH) 984 notify = tcp_quench; 985 else if (icmp_may_rst && cmd == PRC_UNREACH_ADMIN_PROHIB && ip) { 986 tcp_seq_check = 1; 987 notify = tcp_drop_syn_sent; 988 } else if (cmd == PRC_MSGSIZE) 989 notify = tcp_mtudisc; 990 else if (PRC_IS_REDIRECT(cmd)) { 991 /* 992 * Redirects go to all references to the destination, 993 * and use in_rtchange to invalidate the route cache. 994 */ 995 ip = 0; 996 notify = in_rtchange; 997 } else if (cmd == PRC_HOSTDEAD) 998 /* 999 * Dead host indications: notify all references to the 1000 * destination. 1001 */ 1002 ip = 0; 1003 else if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) 1004 return; 1005 if (ip) { 1006 th = (struct tcphdr *)((caddr_t)ip 1007 + (IP_VHL_HL(ip->ip_vhl) << 2)); 1008 if (tcp_seq_check == 1) 1009 tcp_sequence = ntohl(th->th_seq); 1010 in_pcbnotify(&tcb, sa, th->th_dport, ip->ip_src, th->th_sport, 1011 cmd, notify, tcp_sequence, tcp_seq_check); 1012 } else 1013 in_pcbnotifyall(&tcb, sa, cmd, notify); 1014 } 1015 1016 #ifdef INET6 1017 void 1018 tcp6_ctlinput(cmd, sa, d) 1019 int cmd; 1020 struct sockaddr *sa; 1021 void *d; 1022 { 1023 register struct tcphdr *thp; 1024 struct tcphdr th; 1025 void (*notify) __P((struct inpcb *, int)) = tcp_notify; 1026 struct sockaddr_in6 sa6; 1027 struct ip6_hdr *ip6; 1028 struct mbuf *m; 1029 int off; 1030 1031 if (sa->sa_family != AF_INET6 || 1032 sa->sa_len != sizeof(struct sockaddr_in6)) 1033 return; 1034 1035 if (cmd == PRC_QUENCH) 1036 notify = tcp_quench; 1037 else if (cmd == PRC_MSGSIZE) 1038 notify = tcp_mtudisc; 1039 else if (!PRC_IS_REDIRECT(cmd) && 1040 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1041 return; 1042 1043 /* if the parameter is from icmp6, decode it. */ 1044 if (d != NULL) { 1045 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; 1046 m = ip6cp->ip6c_m; 1047 ip6 = ip6cp->ip6c_ip6; 1048 off = ip6cp->ip6c_off; 1049 } else { 1050 m = NULL; 1051 ip6 = NULL; 1052 off = 0; /* fool gcc */ 1053 } 1054 1055 /* 1056 * Translate addresses into internal form. 1057 * Sa check if it is AF_INET6 is done at the top of this funciton. 1058 */ 1059 sa6 = *(struct sockaddr_in6 *)sa; 1060 if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr) != 0 && m != NULL && 1061 m->m_pkthdr.rcvif != NULL) 1062 sa6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 1063 1064 if (ip6) { 1065 /* 1066 * XXX: We assume that when IPV6 is non NULL, 1067 * M and OFF are valid. 1068 */ 1069 struct in6_addr s; 1070 1071 /* translate addresses into internal form */ 1072 memcpy(&s, &ip6->ip6_src, sizeof(s)); 1073 if (IN6_IS_ADDR_LINKLOCAL(&s) != 0 && m != NULL && 1074 m->m_pkthdr.rcvif != NULL) 1075 s.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 1076 1077 /* check if we can safely examine src and dst ports */ 1078 if (m->m_pkthdr.len < off + sizeof(th)) 1079 return; 1080 1081 if (m->m_len < off + sizeof(th)) { 1082 /* 1083 * this should be rare case 1084 * because now MINCLSIZE is "(MHLEN + 1)", 1085 * so we compromise on this copy... 1086 */ 1087 m_copydata(m, off, sizeof(th), (caddr_t)&th); 1088 thp = &th; 1089 } else 1090 thp = (struct tcphdr *)(mtod(m, caddr_t) + off); 1091 in6_pcbnotify(&tcb, (struct sockaddr *)&sa6, thp->th_dport, 1092 &s, thp->th_sport, cmd, notify); 1093 } else 1094 in6_pcbnotify(&tcb, (struct sockaddr *)&sa6, 0, &zeroin6_addr, 1095 0, cmd, notify); 1096 } 1097 #endif /* INET6 */ 1098 1099 /* 1100 * Check if the supplied TCP sequence number is a sequence number 1101 * for a sent but unacknowledged packet on the given TCP session. 1102 */ 1103 int 1104 tcp_seq_vs_sess(inp, tcp_sequence) 1105 struct inpcb *inp; 1106 tcp_seq tcp_sequence; 1107 { 1108 struct tcpcb *tp = intotcpcb(inp); 1109 /* 1110 * If the sequence number is less than that of the last 1111 * unacknowledged packet, or greater than that of the 1112 * last sent, the given sequence number is not that 1113 * of a sent but unacknowledged packet for this session. 1114 */ 1115 if (SEQ_LT(tcp_sequence, tp->snd_una) || 1116 SEQ_GT(tcp_sequence, tp->snd_max)) { 1117 return(0); 1118 } else { 1119 return(1); 1120 } 1121 } 1122 1123 /* 1124 * When a source quench is received, close congestion window 1125 * to one segment. We will gradually open it again as we proceed. 1126 */ 1127 void 1128 tcp_quench(inp, errno) 1129 struct inpcb *inp; 1130 int errno; 1131 { 1132 struct tcpcb *tp = intotcpcb(inp); 1133 1134 if (tp) 1135 tp->snd_cwnd = tp->t_maxseg; 1136 } 1137 1138 /* 1139 * When a specific ICMP unreachable message is received and the 1140 * connection state is SYN-SENT, drop the connection. This behavior 1141 * is controlled by the icmp_may_rst sysctl. 1142 */ 1143 void 1144 tcp_drop_syn_sent(inp, errno) 1145 struct inpcb *inp; 1146 int errno; 1147 { 1148 struct tcpcb *tp = intotcpcb(inp); 1149 1150 if (tp && tp->t_state == TCPS_SYN_SENT) 1151 tcp_drop(tp, errno); 1152 } 1153 1154 /* 1155 * When `need fragmentation' ICMP is received, update our idea of the MSS 1156 * based on the new value in the route. Also nudge TCP to send something, 1157 * since we know the packet we just sent was dropped. 1158 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1159 */ 1160 void 1161 tcp_mtudisc(inp, errno) 1162 struct inpcb *inp; 1163 int errno; 1164 { 1165 struct tcpcb *tp = intotcpcb(inp); 1166 struct rtentry *rt; 1167 struct rmxp_tao *taop; 1168 struct socket *so = inp->inp_socket; 1169 int offered; 1170 int mss; 1171 #ifdef INET6 1172 int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0; 1173 #endif /* INET6 */ 1174 1175 if (tp) { 1176 #ifdef INET6 1177 if (isipv6) 1178 rt = tcp_rtlookup6(inp); 1179 else 1180 #endif /* INET6 */ 1181 rt = tcp_rtlookup(inp); 1182 if (!rt || !rt->rt_rmx.rmx_mtu) { 1183 tp->t_maxopd = tp->t_maxseg = 1184 #ifdef INET6 1185 isipv6 ? tcp_v6mssdflt : 1186 #endif /* INET6 */ 1187 tcp_mssdflt; 1188 return; 1189 } 1190 taop = rmx_taop(rt->rt_rmx); 1191 offered = taop->tao_mssopt; 1192 mss = rt->rt_rmx.rmx_mtu - 1193 #ifdef INET6 1194 (isipv6 ? 1195 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1196 #endif /* INET6 */ 1197 sizeof(struct tcpiphdr) 1198 #ifdef INET6 1199 ) 1200 #endif /* INET6 */ 1201 ; 1202 1203 if (offered) 1204 mss = min(mss, offered); 1205 /* 1206 * XXX - The above conditional probably violates the TCP 1207 * spec. The problem is that, since we don't know the 1208 * other end's MSS, we are supposed to use a conservative 1209 * default. But, if we do that, then MTU discovery will 1210 * never actually take place, because the conservative 1211 * default is much less than the MTUs typically seen 1212 * on the Internet today. For the moment, we'll sweep 1213 * this under the carpet. 1214 * 1215 * The conservative default might not actually be a problem 1216 * if the only case this occurs is when sending an initial 1217 * SYN with options and data to a host we've never talked 1218 * to before. Then, they will reply with an MSS value which 1219 * will get recorded and the new parameters should get 1220 * recomputed. For Further Study. 1221 */ 1222 if (tp->t_maxopd <= mss) 1223 return; 1224 tp->t_maxopd = mss; 1225 1226 if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && 1227 (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP) 1228 mss -= TCPOLEN_TSTAMP_APPA; 1229 if ((tp->t_flags & (TF_REQ_CC|TF_NOOPT)) == TF_REQ_CC && 1230 (tp->t_flags & TF_RCVD_CC) == TF_RCVD_CC) 1231 mss -= TCPOLEN_CC_APPA; 1232 #if (MCLBYTES & (MCLBYTES - 1)) == 0 1233 if (mss > MCLBYTES) 1234 mss &= ~(MCLBYTES-1); 1235 #else 1236 if (mss > MCLBYTES) 1237 mss = mss / MCLBYTES * MCLBYTES; 1238 #endif 1239 if (so->so_snd.sb_hiwat < mss) 1240 mss = so->so_snd.sb_hiwat; 1241 1242 tp->t_maxseg = mss; 1243 1244 tcpstat.tcps_mturesent++; 1245 tp->t_rtttime = 0; 1246 tp->snd_nxt = tp->snd_una; 1247 tcp_output(tp); 1248 } 1249 } 1250 1251 /* 1252 * Look-up the routing entry to the peer of this inpcb. If no route 1253 * is found and it cannot be allocated the return NULL. This routine 1254 * is called by TCP routines that access the rmx structure and by tcp_mss 1255 * to get the interface MTU. 1256 */ 1257 struct rtentry * 1258 tcp_rtlookup(inp) 1259 struct inpcb *inp; 1260 { 1261 struct route *ro; 1262 struct rtentry *rt; 1263 1264 ro = &inp->inp_route; 1265 rt = ro->ro_rt; 1266 if (rt == NULL || !(rt->rt_flags & RTF_UP)) { 1267 /* No route yet, so try to acquire one */ 1268 if (inp->inp_faddr.s_addr != INADDR_ANY) { 1269 ro->ro_dst.sa_family = AF_INET; 1270 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 1271 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1272 inp->inp_faddr; 1273 rtalloc(ro); 1274 rt = ro->ro_rt; 1275 } 1276 } 1277 return rt; 1278 } 1279 1280 #ifdef INET6 1281 struct rtentry * 1282 tcp_rtlookup6(inp) 1283 struct inpcb *inp; 1284 { 1285 struct route_in6 *ro6; 1286 struct rtentry *rt; 1287 1288 ro6 = &inp->in6p_route; 1289 rt = ro6->ro_rt; 1290 if (rt == NULL || !(rt->rt_flags & RTF_UP)) { 1291 /* No route yet, so try to acquire one */ 1292 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) { 1293 ro6->ro_dst.sin6_family = AF_INET6; 1294 ro6->ro_dst.sin6_len = sizeof(ro6->ro_dst); 1295 ro6->ro_dst.sin6_addr = inp->in6p_faddr; 1296 rtalloc((struct route *)ro6); 1297 rt = ro6->ro_rt; 1298 } 1299 } 1300 return rt; 1301 } 1302 #endif /* INET6 */ 1303 1304 #ifdef IPSEC 1305 /* compute ESP/AH header size for TCP, including outer IP header. */ 1306 size_t 1307 ipsec_hdrsiz_tcp(tp) 1308 struct tcpcb *tp; 1309 { 1310 struct inpcb *inp; 1311 struct mbuf *m; 1312 size_t hdrsiz; 1313 struct ip *ip; 1314 #ifdef INET6 1315 struct ip6_hdr *ip6; 1316 #endif /* INET6 */ 1317 struct tcphdr *th; 1318 1319 if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) 1320 return 0; 1321 MGETHDR(m, M_DONTWAIT, MT_DATA); 1322 if (!m) 1323 return 0; 1324 1325 #ifdef INET6 1326 if ((inp->inp_vflag & INP_IPV6) != 0) { 1327 ip6 = mtod(m, struct ip6_hdr *); 1328 th = (struct tcphdr *)(ip6 + 1); 1329 m->m_pkthdr.len = m->m_len = 1330 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1331 bcopy((caddr_t)tp->t_template->tt_ipgen, (caddr_t)ip6, 1332 sizeof(struct ip6_hdr)); 1333 bcopy((caddr_t)&tp->t_template->tt_t, (caddr_t)th, 1334 sizeof(struct tcphdr)); 1335 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1336 } else 1337 #endif /* INET6 */ 1338 { 1339 ip = mtod(m, struct ip *); 1340 th = (struct tcphdr *)(ip + 1); 1341 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1342 bcopy((caddr_t)tp->t_template->tt_ipgen, (caddr_t)ip, 1343 sizeof(struct ip)); 1344 bcopy((caddr_t)&tp->t_template->tt_t, (caddr_t)th, 1345 sizeof(struct tcphdr)); 1346 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1347 } 1348 1349 m_free(m); 1350 return hdrsiz; 1351 } 1352 #endif /*IPSEC*/ 1353 1354 /* 1355 * Return a pointer to the cached information about the remote host. 1356 * The cached information is stored in the protocol specific part of 1357 * the route metrics. 1358 */ 1359 struct rmxp_tao * 1360 tcp_gettaocache(inp) 1361 struct inpcb *inp; 1362 { 1363 struct rtentry *rt; 1364 1365 #ifdef INET6 1366 if ((inp->inp_vflag & INP_IPV6) != 0) 1367 rt = tcp_rtlookup6(inp); 1368 else 1369 #endif /* INET6 */ 1370 rt = tcp_rtlookup(inp); 1371 1372 /* Make sure this is a host route and is up. */ 1373 if (rt == NULL || 1374 (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)) 1375 return NULL; 1376 1377 return rmx_taop(rt->rt_rmx); 1378 } 1379 1380 /* 1381 * Clear all the TAO cache entries, called from tcp_init. 1382 * 1383 * XXX 1384 * This routine is just an empty one, because we assume that the routing 1385 * routing tables are initialized at the same time when TCP, so there is 1386 * nothing in the cache left over. 1387 */ 1388 static void 1389 tcp_cleartaocache() 1390 { 1391 } 1392