1 /* 2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Jeffrey M. Hsu. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of The DragonFly Project nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific, prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 63 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $ 64 */ 65 66 #include "opt_compat.h" 67 #include "opt_inet.h" 68 #include "opt_inet6.h" 69 #include "opt_ipsec.h" 70 #include "opt_tcpdebug.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/callout.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 #include <sys/malloc.h> 78 #include <sys/mpipe.h> 79 #include <sys/mbuf.h> 80 #ifdef INET6 81 #include <sys/domain.h> 82 #endif 83 #include <sys/proc.h> 84 #include <sys/priv.h> 85 #include <sys/socket.h> 86 #include <sys/socketops.h> 87 #include <sys/socketvar.h> 88 #include <sys/protosw.h> 89 #include <sys/random.h> 90 #include <sys/in_cksum.h> 91 #include <sys/ktr.h> 92 93 #include <net/route.h> 94 #include <net/if.h> 95 #include <net/netisr2.h> 96 97 #define _IP_VHL 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #include <netinet/ip.h> 101 #include <netinet/ip6.h> 102 #include <netinet/in_pcb.h> 103 #include <netinet6/in6_pcb.h> 104 #include <netinet/in_var.h> 105 #include <netinet/ip_var.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet/ip_icmp.h> 108 #ifdef INET6 109 #include <netinet/icmp6.h> 110 #endif 111 #include <netinet/tcp.h> 112 #include <netinet/tcp_fsm.h> 113 #include <netinet/tcp_seq.h> 114 #include <netinet/tcp_timer.h> 115 #include <netinet/tcp_timer2.h> 116 #include <netinet/tcp_var.h> 117 #include <netinet6/tcp6_var.h> 118 #include <netinet/tcpip.h> 119 #ifdef TCPDEBUG 120 #include <netinet/tcp_debug.h> 121 #endif 122 #include <netinet6/ip6protosw.h> 123 124 #ifdef IPSEC 125 #include <netinet6/ipsec.h> 126 #include <netproto/key/key.h> 127 #ifdef INET6 128 #include <netinet6/ipsec6.h> 129 #endif 130 #endif 131 132 #ifdef FAST_IPSEC 133 #include <netproto/ipsec/ipsec.h> 134 #ifdef INET6 135 #include <netproto/ipsec/ipsec6.h> 136 #endif 137 #define IPSEC 138 #endif 139 140 #include <sys/md5.h> 141 #include <machine/smp.h> 142 143 #include <sys/msgport2.h> 144 #include <sys/mplock2.h> 145 #include <net/netmsg2.h> 146 147 #if !defined(KTR_TCP) 148 #define KTR_TCP KTR_ALL 149 #endif 150 /* 151 KTR_INFO_MASTER(tcp); 152 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 153 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 154 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 155 #define logtcp(name) KTR_LOG(tcp_ ## name) 156 */ 157 158 #define TCP_IW_MAXSEGS_DFLT 4 159 #define TCP_IW_CAPSEGS_DFLT 3 160 161 struct inpcbinfo tcbinfo[MAXCPU]; 162 struct tcpcbackqhead tcpcbackq[MAXCPU]; 163 164 int tcp_mssdflt = TCP_MSS; 165 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 166 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 167 168 #ifdef INET6 169 int tcp_v6mssdflt = TCP6_MSS; 170 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 171 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 172 #endif 173 174 /* 175 * Minimum MSS we accept and use. This prevents DoS attacks where 176 * we are forced to a ridiculous low MSS like 20 and send hundreds 177 * of packets instead of one. The effect scales with the available 178 * bandwidth and quickly saturates the CPU and network interface 179 * with packet generation and sending. Set to zero to disable MINMSS 180 * checking. This setting prevents us from sending too small packets. 181 */ 182 int tcp_minmss = TCP_MINMSS; 183 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 184 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 185 186 #if 0 187 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 188 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 189 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 190 #endif 191 192 int tcp_do_rfc1323 = 1; 193 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 194 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 195 196 static int tcp_tcbhashsize = 0; 197 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 198 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 199 200 static int do_tcpdrain = 1; 201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 202 "Enable tcp_drain routine for extra help when low on mbufs"); 203 204 static int icmp_may_rst = 1; 205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 206 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 207 208 static int tcp_isn_reseed_interval = 0; 209 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 210 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 211 212 /* 213 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 214 * by default, but with generous values which should allow maximal 215 * bandwidth. In particular, the slop defaults to 50 (5 packets). 216 * 217 * The reason for doing this is that the limiter is the only mechanism we 218 * have which seems to do a really good job preventing receiver RX rings 219 * on network interfaces from getting blown out. Even though GigE/10GigE 220 * is supposed to flow control it looks like either it doesn't actually 221 * do it or Open Source drivers do not properly enable it. 222 * 223 * People using the limiter to reduce bottlenecks on slower WAN connections 224 * should set the slop to 20 (2 packets). 225 */ 226 static int tcp_inflight_enable = 1; 227 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 228 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 229 230 static int tcp_inflight_debug = 0; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 232 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 233 234 static int tcp_inflight_min = 6144; 235 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 236 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 237 238 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 239 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 240 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 241 242 static int tcp_inflight_stab = 50; 243 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 244 &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)"); 245 246 static int tcp_inflight_adjrtt = 2; 247 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW, 248 &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)"); 249 250 static int tcp_do_rfc3390 = 1; 251 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW, 252 &tcp_do_rfc3390, 0, 253 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)"); 254 255 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 256 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW, 257 &tcp_iw_maxsegs, 0, "TCP IW segments max"); 258 259 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 260 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW, 261 &tcp_iw_capsegs, 0, "TCP IW segments"); 262 263 int tcp_low_rtobase = 1; 264 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW, 265 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)"); 266 267 static int tcp_do_ncr = 1; 268 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW, 269 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)"); 270 271 int tcp_ncr_rxtthresh_max = 16; 272 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW, 273 &tcp_ncr_rxtthresh_max, 0, 274 "Non-Congestion Robustness (RFC 4653), DupThresh upper limit"); 275 276 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 277 static struct malloc_pipe tcptemp_mpipe; 278 279 static void tcp_willblock(void); 280 static void tcp_notify (struct inpcb *, int); 281 282 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign; 283 284 static int 285 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 286 { 287 int cpu, error = 0; 288 289 for (cpu = 0; cpu < ncpus2; ++cpu) { 290 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 291 sizeof(struct tcp_stats)))) 292 break; 293 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 294 sizeof(struct tcp_stats)))) 295 break; 296 } 297 298 return (error); 299 } 300 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 301 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 302 303 /* 304 * Target size of TCP PCB hash tables. Must be a power of two. 305 * 306 * Note that this can be overridden by the kernel environment 307 * variable net.inet.tcp.tcbhashsize 308 */ 309 #ifndef TCBHASHSIZE 310 #define TCBHASHSIZE 512 311 #endif 312 313 /* 314 * This is the actual shape of what we allocate using the zone 315 * allocator. Doing it this way allows us to protect both structures 316 * using the same generation count, and also eliminates the overhead 317 * of allocating tcpcbs separately. By hiding the structure here, 318 * we avoid changing most of the rest of the code (although it needs 319 * to be changed, eventually, for greater efficiency). 320 */ 321 #define ALIGNMENT 32 322 #define ALIGNM1 (ALIGNMENT - 1) 323 struct inp_tp { 324 union { 325 struct inpcb inp; 326 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 327 } inp_tp_u; 328 struct tcpcb tcb; 329 struct tcp_callout inp_tp_rexmt; 330 struct tcp_callout inp_tp_persist; 331 struct tcp_callout inp_tp_keep; 332 struct tcp_callout inp_tp_2msl; 333 struct tcp_callout inp_tp_delack; 334 struct netmsg_tcp_timer inp_tp_timermsg; 335 struct netmsg_base inp_tp_sndmore; 336 }; 337 #undef ALIGNMENT 338 #undef ALIGNM1 339 340 /* 341 * Tcp initialization 342 */ 343 void 344 tcp_init(void) 345 { 346 struct inpcbportinfo *portinfo; 347 struct inpcbinfo *ticb; 348 int hashsize = TCBHASHSIZE; 349 int cpu; 350 351 /* 352 * note: tcptemp is used for keepalives, and it is ok for an 353 * allocation to fail so do not specify MPF_INT. 354 */ 355 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 356 25, -1, 0, NULL, NULL, NULL); 357 358 tcp_delacktime = TCPTV_DELACK; 359 tcp_keepinit = TCPTV_KEEP_INIT; 360 tcp_keepidle = TCPTV_KEEP_IDLE; 361 tcp_keepintvl = TCPTV_KEEPINTVL; 362 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 363 tcp_msl = TCPTV_MSL; 364 tcp_rexmit_min = TCPTV_MIN; 365 tcp_rexmit_slop = TCPTV_CPU_VAR; 366 367 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 368 if (!powerof2(hashsize)) { 369 kprintf("WARNING: TCB hash size not a power of 2\n"); 370 hashsize = 512; /* safe default */ 371 } 372 tcp_tcbhashsize = hashsize; 373 374 portinfo = kmalloc_cachealign(sizeof(*portinfo) * ncpus2, M_PCB, 375 M_WAITOK); 376 377 for (cpu = 0; cpu < ncpus2; cpu++) { 378 ticb = &tcbinfo[cpu]; 379 in_pcbinfo_init(ticb); 380 ticb->cpu = cpu; 381 ticb->hashbase = hashinit(hashsize, M_PCB, 382 &ticb->hashmask); 383 in_pcbportinfo_init(&portinfo[cpu], hashsize, TRUE, cpu); 384 ticb->portinfo = portinfo; 385 ticb->portinfo_mask = ncpus2_mask; 386 ticb->wildcardhashbase = hashinit(hashsize, M_PCB, 387 &ticb->wildcardhashmask); 388 ticb->localgrphashbase = hashinit(hashsize, M_PCB, 389 &ticb->localgrphashmask); 390 ticb->ipi_size = sizeof(struct inp_tp); 391 TAILQ_INIT(&tcpcbackq[cpu]); 392 } 393 394 tcp_reass_maxseg = nmbclusters / 16; 395 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 396 397 #ifdef INET6 398 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 399 #else 400 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 401 #endif 402 if (max_protohdr < TCP_MINPROTOHDR) 403 max_protohdr = TCP_MINPROTOHDR; 404 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 405 panic("tcp_init"); 406 #undef TCP_MINPROTOHDR 407 408 /* 409 * Initialize TCP statistics counters for each CPU. 410 */ 411 for (cpu = 0; cpu < ncpus2; ++cpu) 412 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 413 414 syncache_init(); 415 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP); 416 } 417 418 static void 419 tcp_willblock(void) 420 { 421 struct tcpcb *tp; 422 int cpu = mycpu->gd_cpuid; 423 424 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 425 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 426 tp->t_flags &= ~TF_ONOUTPUTQ; 427 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 428 tcp_output(tp); 429 } 430 } 431 432 /* 433 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 434 * tcp_template used to store this data in mbufs, but we now recopy it out 435 * of the tcpcb each time to conserve mbufs. 436 */ 437 void 438 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso) 439 { 440 struct inpcb *inp = tp->t_inpcb; 441 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 442 443 #ifdef INET6 444 if (inp->inp_vflag & INP_IPV6) { 445 struct ip6_hdr *ip6; 446 447 ip6 = (struct ip6_hdr *)ip_ptr; 448 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 449 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 450 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 451 (IPV6_VERSION & IPV6_VERSION_MASK); 452 ip6->ip6_nxt = IPPROTO_TCP; 453 ip6->ip6_plen = sizeof(struct tcphdr); 454 ip6->ip6_src = inp->in6p_laddr; 455 ip6->ip6_dst = inp->in6p_faddr; 456 tcp_hdr->th_sum = 0; 457 } else 458 #endif 459 { 460 struct ip *ip = (struct ip *) ip_ptr; 461 u_int plen; 462 463 ip->ip_vhl = IP_VHL_BORING; 464 ip->ip_tos = 0; 465 ip->ip_len = 0; 466 ip->ip_id = 0; 467 ip->ip_off = 0; 468 ip->ip_ttl = 0; 469 ip->ip_sum = 0; 470 ip->ip_p = IPPROTO_TCP; 471 ip->ip_src = inp->inp_laddr; 472 ip->ip_dst = inp->inp_faddr; 473 474 if (tso) 475 plen = htons(IPPROTO_TCP); 476 else 477 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP); 478 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 479 ip->ip_dst.s_addr, plen); 480 } 481 482 tcp_hdr->th_sport = inp->inp_lport; 483 tcp_hdr->th_dport = inp->inp_fport; 484 tcp_hdr->th_seq = 0; 485 tcp_hdr->th_ack = 0; 486 tcp_hdr->th_x2 = 0; 487 tcp_hdr->th_off = 5; 488 tcp_hdr->th_flags = 0; 489 tcp_hdr->th_win = 0; 490 tcp_hdr->th_urp = 0; 491 } 492 493 /* 494 * Create template to be used to send tcp packets on a connection. 495 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 496 * use for this function is in keepalives, which use tcp_respond. 497 */ 498 struct tcptemp * 499 tcp_maketemplate(struct tcpcb *tp) 500 { 501 struct tcptemp *tmp; 502 503 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 504 return (NULL); 505 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE); 506 return (tmp); 507 } 508 509 void 510 tcp_freetemplate(struct tcptemp *tmp) 511 { 512 mpipe_free(&tcptemp_mpipe, tmp); 513 } 514 515 /* 516 * Send a single message to the TCP at address specified by 517 * the given TCP/IP header. If m == NULL, then we make a copy 518 * of the tcpiphdr at ti and send directly to the addressed host. 519 * This is used to force keep alive messages out using the TCP 520 * template for a connection. If flags are given then we send 521 * a message back to the TCP which originated the * segment ti, 522 * and discard the mbuf containing it and any other attached mbufs. 523 * 524 * In any case the ack and sequence number of the transmitted 525 * segment are as specified by the parameters. 526 * 527 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 528 */ 529 void 530 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 531 tcp_seq ack, tcp_seq seq, int flags) 532 { 533 int tlen; 534 long win = 0; 535 struct route *ro = NULL; 536 struct route sro; 537 struct ip *ip = ipgen; 538 struct tcphdr *nth; 539 int ipflags = 0; 540 struct route_in6 *ro6 = NULL; 541 struct route_in6 sro6; 542 struct ip6_hdr *ip6 = ipgen; 543 boolean_t use_tmpro = TRUE; 544 #ifdef INET6 545 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 546 #else 547 const boolean_t isipv6 = FALSE; 548 #endif 549 550 if (tp != NULL) { 551 if (!(flags & TH_RST)) { 552 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 553 if (win < 0) 554 win = 0; 555 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 556 win = (long)TCP_MAXWIN << tp->rcv_scale; 557 } 558 /* 559 * Don't use the route cache of a listen socket, 560 * it is not MPSAFE; use temporary route cache. 561 */ 562 if (tp->t_state != TCPS_LISTEN) { 563 if (isipv6) 564 ro6 = &tp->t_inpcb->in6p_route; 565 else 566 ro = &tp->t_inpcb->inp_route; 567 use_tmpro = FALSE; 568 } 569 } 570 if (use_tmpro) { 571 if (isipv6) { 572 ro6 = &sro6; 573 bzero(ro6, sizeof *ro6); 574 } else { 575 ro = &sro; 576 bzero(ro, sizeof *ro); 577 } 578 } 579 if (m == NULL) { 580 m = m_gethdr(MB_DONTWAIT, MT_HEADER); 581 if (m == NULL) 582 return; 583 tlen = 0; 584 m->m_data += max_linkhdr; 585 if (isipv6) { 586 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 587 ip6 = mtod(m, struct ip6_hdr *); 588 nth = (struct tcphdr *)(ip6 + 1); 589 } else { 590 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 591 ip = mtod(m, struct ip *); 592 nth = (struct tcphdr *)(ip + 1); 593 } 594 bcopy(th, nth, sizeof(struct tcphdr)); 595 flags = TH_ACK; 596 } else { 597 m_freem(m->m_next); 598 m->m_next = NULL; 599 m->m_data = (caddr_t)ipgen; 600 /* m_len is set later */ 601 tlen = 0; 602 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 603 if (isipv6) { 604 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 605 nth = (struct tcphdr *)(ip6 + 1); 606 } else { 607 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 608 nth = (struct tcphdr *)(ip + 1); 609 } 610 if (th != nth) { 611 /* 612 * this is usually a case when an extension header 613 * exists between the IPv6 header and the 614 * TCP header. 615 */ 616 nth->th_sport = th->th_sport; 617 nth->th_dport = th->th_dport; 618 } 619 xchg(nth->th_dport, nth->th_sport, n_short); 620 #undef xchg 621 } 622 if (isipv6) { 623 ip6->ip6_flow = 0; 624 ip6->ip6_vfc = IPV6_VERSION; 625 ip6->ip6_nxt = IPPROTO_TCP; 626 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 627 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 628 } else { 629 tlen += sizeof(struct tcpiphdr); 630 ip->ip_len = tlen; 631 ip->ip_ttl = ip_defttl; 632 } 633 m->m_len = tlen; 634 m->m_pkthdr.len = tlen; 635 m->m_pkthdr.rcvif = NULL; 636 nth->th_seq = htonl(seq); 637 nth->th_ack = htonl(ack); 638 nth->th_x2 = 0; 639 nth->th_off = sizeof(struct tcphdr) >> 2; 640 nth->th_flags = flags; 641 if (tp != NULL) 642 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 643 else 644 nth->th_win = htons((u_short)win); 645 nth->th_urp = 0; 646 if (isipv6) { 647 nth->th_sum = 0; 648 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 649 sizeof(struct ip6_hdr), 650 tlen - sizeof(struct ip6_hdr)); 651 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 652 (ro6 && ro6->ro_rt) ? 653 ro6->ro_rt->rt_ifp : NULL); 654 } else { 655 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 656 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 657 m->m_pkthdr.csum_flags = CSUM_TCP; 658 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 659 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr); 660 } 661 #ifdef TCPDEBUG 662 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 663 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 664 #endif 665 if (isipv6) { 666 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 667 tp ? tp->t_inpcb : NULL); 668 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 669 RTFREE(ro6->ro_rt); 670 ro6->ro_rt = NULL; 671 } 672 } else { 673 ipflags |= IP_DEBUGROUTE; 674 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 675 if ((ro == &sro) && (ro->ro_rt != NULL)) { 676 RTFREE(ro->ro_rt); 677 ro->ro_rt = NULL; 678 } 679 } 680 } 681 682 /* 683 * Create a new TCP control block, making an 684 * empty reassembly queue and hooking it to the argument 685 * protocol control block. The `inp' parameter must have 686 * come from the zone allocator set up in tcp_init(). 687 */ 688 struct tcpcb * 689 tcp_newtcpcb(struct inpcb *inp) 690 { 691 struct inp_tp *it; 692 struct tcpcb *tp; 693 #ifdef INET6 694 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 695 #else 696 const boolean_t isipv6 = FALSE; 697 #endif 698 699 it = (struct inp_tp *)inp; 700 tp = &it->tcb; 701 bzero(tp, sizeof(struct tcpcb)); 702 TAILQ_INIT(&tp->t_segq); 703 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 704 tp->t_rxtthresh = tcprexmtthresh; 705 706 /* Set up our timeouts. */ 707 tp->tt_rexmt = &it->inp_tp_rexmt; 708 tp->tt_persist = &it->inp_tp_persist; 709 tp->tt_keep = &it->inp_tp_keep; 710 tp->tt_2msl = &it->inp_tp_2msl; 711 tp->tt_delack = &it->inp_tp_delack; 712 tcp_inittimers(tp); 713 714 /* 715 * Zero out timer message. We don't create it here, 716 * since the current CPU may not be the owner of this 717 * inpcb. 718 */ 719 tp->tt_msg = &it->inp_tp_timermsg; 720 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 721 722 tp->t_keepinit = tcp_keepinit; 723 tp->t_keepidle = tcp_keepidle; 724 tp->t_keepintvl = tcp_keepintvl; 725 tp->t_keepcnt = tcp_keepcnt; 726 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt; 727 728 if (tcp_do_ncr) 729 tp->t_flags |= TF_NCR; 730 if (tcp_do_rfc1323) 731 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP); 732 733 tp->t_inpcb = inp; /* XXX */ 734 tp->t_state = TCPS_CLOSED; 735 /* 736 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 737 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 738 * reasonable initial retransmit time. 739 */ 740 tp->t_srtt = TCPTV_SRTTBASE; 741 tp->t_rttvar = 742 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 743 tp->t_rttmin = tcp_rexmit_min; 744 tp->t_rxtcur = TCPTV_RTOBASE; 745 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 746 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 747 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 748 tp->snd_last = ticks; 749 tp->t_rcvtime = ticks; 750 /* 751 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 752 * because the socket may be bound to an IPv6 wildcard address, 753 * which may match an IPv4-mapped IPv6 address. 754 */ 755 inp->inp_ip_ttl = ip_defttl; 756 inp->inp_ppcb = tp; 757 tcp_sack_tcpcb_init(tp); 758 759 tp->tt_sndmore = &it->inp_tp_sndmore; 760 tcp_output_init(tp); 761 762 return (tp); /* XXX */ 763 } 764 765 /* 766 * Drop a TCP connection, reporting the specified error. 767 * If connection is synchronized, then send a RST to peer. 768 */ 769 struct tcpcb * 770 tcp_drop(struct tcpcb *tp, int error) 771 { 772 struct socket *so = tp->t_inpcb->inp_socket; 773 774 if (TCPS_HAVERCVDSYN(tp->t_state)) { 775 tp->t_state = TCPS_CLOSED; 776 tcp_output(tp); 777 tcpstat.tcps_drops++; 778 } else 779 tcpstat.tcps_conndrops++; 780 if (error == ETIMEDOUT && tp->t_softerror) 781 error = tp->t_softerror; 782 so->so_error = error; 783 return (tcp_close(tp)); 784 } 785 786 struct netmsg_listen_detach { 787 struct netmsg_base base; 788 struct tcpcb *nm_tp; 789 struct tcpcb *nm_tp_inh; 790 }; 791 792 static void 793 tcp_listen_detach_handler(netmsg_t msg) 794 { 795 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; 796 struct tcpcb *tp = nmsg->nm_tp; 797 int cpu = mycpuid, nextcpu; 798 799 if (tp->t_flags & TF_LISTEN) 800 syncache_destroy(tp, nmsg->nm_tp_inh); 801 802 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); 803 804 nextcpu = cpu + 1; 805 if (nextcpu < ncpus2) 806 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg); 807 else 808 lwkt_replymsg(&nmsg->base.lmsg, 0); 809 } 810 811 /* 812 * Close a TCP control block: 813 * discard all space held by the tcp 814 * discard internet protocol block 815 * wake up any sleepers 816 */ 817 struct tcpcb * 818 tcp_close(struct tcpcb *tp) 819 { 820 struct tseg_qent *q; 821 struct inpcb *inp = tp->t_inpcb; 822 struct inpcb *inp_inh = NULL; 823 struct tcpcb *tp_inh = NULL; 824 struct socket *so = inp->inp_socket; 825 struct rtentry *rt; 826 boolean_t dosavessthresh; 827 #ifdef INET6 828 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 829 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 830 #else 831 const boolean_t isipv6 = FALSE; 832 #endif 833 834 if (tp->t_flags & TF_LISTEN) { 835 /* 836 * Pending socket/syncache inheritance 837 * 838 * If this is a listen(2) socket, find another listen(2) 839 * socket in the same local group, which could inherit 840 * the syncache and sockets pending on the completion 841 * and incompletion queues. 842 * 843 * NOTE: 844 * Currently the inheritance could only happen on the 845 * listen(2) sockets w/ SO_REUSEPORT set. 846 */ 847 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 848 ("listen socket close not in netisr0")); 849 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp); 850 if (inp_inh != NULL) 851 tp_inh = intotcpcb(inp_inh); 852 } 853 854 /* 855 * INP_WILDCARD_MP indicates that listen(2) has been called on 856 * this socket. This implies: 857 * - A wildcard inp's hash is replicated for each protocol thread. 858 * - Syncache for this inp grows independently in each protocol 859 * thread. 860 * - There is more than one cpu 861 * 862 * We have to chain a message to the rest of the protocol threads 863 * to cleanup the wildcard hash and the syncache. The cleanup 864 * in the current protocol thread is defered till the end of this 865 * function. 866 * 867 * NOTE: 868 * After cleanup the inp's hash and syncache entries, this inp will 869 * no longer be available to the rest of the protocol threads, so we 870 * are safe to whack the inp in the following code. 871 */ 872 if (inp->inp_flags & INP_WILDCARD_MP) { 873 struct netmsg_listen_detach nmsg; 874 875 KKASSERT(so->so_port == netisr_cpuport(0)); 876 KKASSERT(&curthread->td_msgport == netisr_cpuport(0)); 877 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); 878 879 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, 880 MSGF_PRIORITY, tcp_listen_detach_handler); 881 nmsg.nm_tp = tp; 882 nmsg.nm_tp_inh = tp_inh; 883 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0); 884 885 inp->inp_flags &= ~INP_WILDCARD_MP; 886 } 887 888 KKASSERT(tp->t_state != TCPS_TERMINATING); 889 tp->t_state = TCPS_TERMINATING; 890 891 /* 892 * Make sure that all of our timers are stopped before we 893 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 894 * timers are never used. If timer message is never created 895 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 896 */ 897 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 898 tcp_callout_stop(tp, tp->tt_rexmt); 899 tcp_callout_stop(tp, tp->tt_persist); 900 tcp_callout_stop(tp, tp->tt_keep); 901 tcp_callout_stop(tp, tp->tt_2msl); 902 tcp_callout_stop(tp, tp->tt_delack); 903 } 904 905 if (tp->t_flags & TF_ONOUTPUTQ) { 906 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 907 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 908 tp->t_flags &= ~TF_ONOUTPUTQ; 909 } 910 911 /* 912 * If we got enough samples through the srtt filter, 913 * save the rtt and rttvar in the routing entry. 914 * 'Enough' is arbitrarily defined as the 16 samples. 915 * 16 samples is enough for the srtt filter to converge 916 * to within 5% of the correct value; fewer samples and 917 * we could save a very bogus rtt. 918 * 919 * Don't update the default route's characteristics and don't 920 * update anything that the user "locked". 921 */ 922 if (tp->t_rttupdated >= 16) { 923 u_long i = 0; 924 925 if (isipv6) { 926 struct sockaddr_in6 *sin6; 927 928 if ((rt = inp->in6p_route.ro_rt) == NULL) 929 goto no_valid_rt; 930 sin6 = (struct sockaddr_in6 *)rt_key(rt); 931 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 932 goto no_valid_rt; 933 } else 934 if ((rt = inp->inp_route.ro_rt) == NULL || 935 ((struct sockaddr_in *)rt_key(rt))-> 936 sin_addr.s_addr == INADDR_ANY) 937 goto no_valid_rt; 938 939 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 940 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 941 if (rt->rt_rmx.rmx_rtt && i) 942 /* 943 * filter this update to half the old & half 944 * the new values, converting scale. 945 * See route.h and tcp_var.h for a 946 * description of the scaling constants. 947 */ 948 rt->rt_rmx.rmx_rtt = 949 (rt->rt_rmx.rmx_rtt + i) / 2; 950 else 951 rt->rt_rmx.rmx_rtt = i; 952 tcpstat.tcps_cachedrtt++; 953 } 954 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 955 i = tp->t_rttvar * 956 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 957 if (rt->rt_rmx.rmx_rttvar && i) 958 rt->rt_rmx.rmx_rttvar = 959 (rt->rt_rmx.rmx_rttvar + i) / 2; 960 else 961 rt->rt_rmx.rmx_rttvar = i; 962 tcpstat.tcps_cachedrttvar++; 963 } 964 /* 965 * The old comment here said: 966 * update the pipelimit (ssthresh) if it has been updated 967 * already or if a pipesize was specified & the threshhold 968 * got below half the pipesize. I.e., wait for bad news 969 * before we start updating, then update on both good 970 * and bad news. 971 * 972 * But we want to save the ssthresh even if no pipesize is 973 * specified explicitly in the route, because such 974 * connections still have an implicit pipesize specified 975 * by the global tcp_sendspace. In the absence of a reliable 976 * way to calculate the pipesize, it will have to do. 977 */ 978 i = tp->snd_ssthresh; 979 if (rt->rt_rmx.rmx_sendpipe != 0) 980 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 981 else 982 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 983 if (dosavessthresh || 984 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 985 (rt->rt_rmx.rmx_ssthresh != 0))) { 986 /* 987 * convert the limit from user data bytes to 988 * packets then to packet data bytes. 989 */ 990 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 991 if (i < 2) 992 i = 2; 993 i *= tp->t_maxseg + 994 (isipv6 ? 995 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 996 sizeof(struct tcpiphdr)); 997 if (rt->rt_rmx.rmx_ssthresh) 998 rt->rt_rmx.rmx_ssthresh = 999 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1000 else 1001 rt->rt_rmx.rmx_ssthresh = i; 1002 tcpstat.tcps_cachedssthresh++; 1003 } 1004 } 1005 1006 no_valid_rt: 1007 /* free the reassembly queue, if any */ 1008 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) { 1009 TAILQ_REMOVE(&tp->t_segq, q, tqe_q); 1010 m_freem(q->tqe_m); 1011 kfree(q, M_TSEGQ); 1012 atomic_add_int(&tcp_reass_qsize, -1); 1013 } 1014 /* throw away SACK blocks in scoreboard*/ 1015 if (TCP_DO_SACK(tp)) 1016 tcp_sack_destroy(&tp->scb); 1017 1018 inp->inp_ppcb = NULL; 1019 soisdisconnected(so); 1020 /* note: pcb detached later on */ 1021 1022 tcp_destroy_timermsg(tp); 1023 tcp_output_cancel(tp); 1024 1025 if (tp->t_flags & TF_LISTEN) { 1026 syncache_destroy(tp, tp_inh); 1027 if (inp_inh != NULL && inp_inh->inp_socket != NULL) { 1028 /* 1029 * Pending sockets inheritance only needs 1030 * to be done once in the current thread, 1031 * i.e. netisr0. 1032 */ 1033 soinherit(so, inp_inh->inp_socket); 1034 } 1035 } 1036 1037 so_async_rcvd_drop(so); 1038 /* Drop the reference for the asynchronized pru_rcvd */ 1039 sofree(so); 1040 1041 /* 1042 * NOTE: 1043 * pcbdetach removes any wildcard hash entry on the current CPU. 1044 */ 1045 #ifdef INET6 1046 if (isafinet6) 1047 in6_pcbdetach(inp); 1048 else 1049 #endif 1050 in_pcbdetach(inp); 1051 1052 tcpstat.tcps_closed++; 1053 return (NULL); 1054 } 1055 1056 static __inline void 1057 tcp_drain_oncpu(struct inpcbhead *head) 1058 { 1059 struct inpcb *marker; 1060 struct inpcb *inpb; 1061 struct tcpcb *tcpb; 1062 struct tseg_qent *te; 1063 1064 /* 1065 * Allows us to block while running the list 1066 */ 1067 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1068 marker->inp_flags |= INP_PLACEMARKER; 1069 LIST_INSERT_HEAD(head, marker, inp_list); 1070 1071 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) { 1072 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 && 1073 (tcpb = intotcpcb(inpb)) != NULL && 1074 (te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) { 1075 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q); 1076 if (te->tqe_th->th_flags & TH_FIN) 1077 tcpb->t_flags &= ~TF_QUEDFIN; 1078 m_freem(te->tqe_m); 1079 kfree(te, M_TSEGQ); 1080 atomic_add_int(&tcp_reass_qsize, -1); 1081 /* retry */ 1082 } else { 1083 LIST_REMOVE(marker, inp_list); 1084 LIST_INSERT_AFTER(inpb, marker, inp_list); 1085 } 1086 } 1087 LIST_REMOVE(marker, inp_list); 1088 kfree(marker, M_TEMP); 1089 } 1090 1091 struct netmsg_tcp_drain { 1092 struct netmsg_base base; 1093 struct inpcbhead *nm_head; 1094 }; 1095 1096 static void 1097 tcp_drain_handler(netmsg_t msg) 1098 { 1099 struct netmsg_tcp_drain *nm = (void *)msg; 1100 1101 tcp_drain_oncpu(nm->nm_head); 1102 lwkt_replymsg(&nm->base.lmsg, 0); 1103 } 1104 1105 void 1106 tcp_drain(void) 1107 { 1108 int cpu; 1109 1110 if (!do_tcpdrain) 1111 return; 1112 1113 /* 1114 * Walk the tcpbs, if existing, and flush the reassembly queue, 1115 * if there is one... 1116 * XXX: The "Net/3" implementation doesn't imply that the TCP 1117 * reassembly queue should be flushed, but in a situation 1118 * where we're really low on mbufs, this is potentially 1119 * useful. 1120 */ 1121 for (cpu = 0; cpu < ncpus2; cpu++) { 1122 struct netmsg_tcp_drain *nm; 1123 1124 if (cpu == mycpu->gd_cpuid) { 1125 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1126 } else { 1127 nm = kmalloc(sizeof(struct netmsg_tcp_drain), 1128 M_LWKTMSG, M_NOWAIT); 1129 if (nm == NULL) 1130 continue; 1131 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1132 0, tcp_drain_handler); 1133 nm->nm_head = &tcbinfo[cpu].pcblisthead; 1134 lwkt_sendmsg(netisr_cpuport(cpu), &nm->base.lmsg); 1135 } 1136 } 1137 } 1138 1139 /* 1140 * Notify a tcp user of an asynchronous error; 1141 * store error as soft error, but wake up user 1142 * (for now, won't do anything until can select for soft error). 1143 * 1144 * Do not wake up user since there currently is no mechanism for 1145 * reporting soft errors (yet - a kqueue filter may be added). 1146 */ 1147 static void 1148 tcp_notify(struct inpcb *inp, int error) 1149 { 1150 struct tcpcb *tp = intotcpcb(inp); 1151 1152 /* 1153 * Ignore some errors if we are hooked up. 1154 * If connection hasn't completed, has retransmitted several times, 1155 * and receives a second error, give up now. This is better 1156 * than waiting a long time to establish a connection that 1157 * can never complete. 1158 */ 1159 if (tp->t_state == TCPS_ESTABLISHED && 1160 (error == EHOSTUNREACH || error == ENETUNREACH || 1161 error == EHOSTDOWN)) { 1162 return; 1163 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1164 tp->t_softerror) 1165 tcp_drop(tp, error); 1166 else 1167 tp->t_softerror = error; 1168 #if 0 1169 wakeup(&so->so_timeo); 1170 sorwakeup(so); 1171 sowwakeup(so); 1172 #endif 1173 } 1174 1175 static int 1176 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1177 { 1178 int error, i, n; 1179 struct inpcb *marker; 1180 struct inpcb *inp; 1181 globaldata_t gd; 1182 int origcpu, ccpu; 1183 1184 error = 0; 1185 n = 0; 1186 1187 /* 1188 * The process of preparing the TCB list is too time-consuming and 1189 * resource-intensive to repeat twice on every request. 1190 */ 1191 if (req->oldptr == NULL) { 1192 for (ccpu = 0; ccpu < ncpus2; ++ccpu) { 1193 gd = globaldata_find(ccpu); 1194 n += tcbinfo[gd->gd_cpuid].ipi_count; 1195 } 1196 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1197 return (0); 1198 } 1199 1200 if (req->newptr != NULL) 1201 return (EPERM); 1202 1203 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1204 marker->inp_flags |= INP_PLACEMARKER; 1205 1206 /* 1207 * OK, now we're committed to doing something. Run the inpcb list 1208 * for each cpu in the system and construct the output. Use a 1209 * list placemarker to deal with list changes occuring during 1210 * copyout blockages (but otherwise depend on being on the correct 1211 * cpu to avoid races). 1212 */ 1213 origcpu = mycpu->gd_cpuid; 1214 for (ccpu = 0; ccpu < ncpus2 && error == 0; ++ccpu) { 1215 caddr_t inp_ppcb; 1216 struct xtcpcb xt; 1217 1218 lwkt_migratecpu(ccpu); 1219 1220 n = tcbinfo[ccpu].ipi_count; 1221 1222 LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list); 1223 i = 0; 1224 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1225 /* 1226 * process a snapshot of pcbs, ignoring placemarkers 1227 * and using our own to allow SYSCTL_OUT to block. 1228 */ 1229 LIST_REMOVE(marker, inp_list); 1230 LIST_INSERT_AFTER(inp, marker, inp_list); 1231 1232 if (inp->inp_flags & INP_PLACEMARKER) 1233 continue; 1234 if (prison_xinpcb(req->td, inp)) 1235 continue; 1236 1237 xt.xt_len = sizeof xt; 1238 bcopy(inp, &xt.xt_inp, sizeof *inp); 1239 inp_ppcb = inp->inp_ppcb; 1240 if (inp_ppcb != NULL) 1241 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1242 else 1243 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1244 if (inp->inp_socket) 1245 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1246 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1247 break; 1248 ++i; 1249 } 1250 LIST_REMOVE(marker, inp_list); 1251 if (error == 0 && i < n) { 1252 bzero(&xt, sizeof xt); 1253 xt.xt_len = sizeof xt; 1254 while (i < n) { 1255 error = SYSCTL_OUT(req, &xt, sizeof xt); 1256 if (error) 1257 break; 1258 ++i; 1259 } 1260 } 1261 } 1262 1263 /* 1264 * Make sure we are on the same cpu we were on originally, since 1265 * higher level callers expect this. Also don't pollute caches with 1266 * migrated userland data by (eventually) returning to userland 1267 * on a different cpu. 1268 */ 1269 lwkt_migratecpu(origcpu); 1270 kfree(marker, M_TEMP); 1271 return (error); 1272 } 1273 1274 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1275 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1276 1277 static int 1278 tcp_getcred(SYSCTL_HANDLER_ARGS) 1279 { 1280 struct sockaddr_in addrs[2]; 1281 struct inpcb *inp; 1282 int cpu; 1283 int error; 1284 1285 error = priv_check(req->td, PRIV_ROOT); 1286 if (error != 0) 1287 return (error); 1288 error = SYSCTL_IN(req, addrs, sizeof addrs); 1289 if (error != 0) 1290 return (error); 1291 crit_enter(); 1292 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1293 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1294 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1295 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1296 if (inp == NULL || inp->inp_socket == NULL) { 1297 error = ENOENT; 1298 goto out; 1299 } 1300 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1301 out: 1302 crit_exit(); 1303 return (error); 1304 } 1305 1306 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1307 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1308 1309 #ifdef INET6 1310 static int 1311 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1312 { 1313 struct sockaddr_in6 addrs[2]; 1314 struct inpcb *inp; 1315 int error; 1316 boolean_t mapped = FALSE; 1317 1318 error = priv_check(req->td, PRIV_ROOT); 1319 if (error != 0) 1320 return (error); 1321 error = SYSCTL_IN(req, addrs, sizeof addrs); 1322 if (error != 0) 1323 return (error); 1324 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1325 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1326 mapped = TRUE; 1327 else 1328 return (EINVAL); 1329 } 1330 crit_enter(); 1331 if (mapped) { 1332 inp = in_pcblookup_hash(&tcbinfo[0], 1333 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1334 addrs[1].sin6_port, 1335 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1336 addrs[0].sin6_port, 1337 0, NULL); 1338 } else { 1339 inp = in6_pcblookup_hash(&tcbinfo[0], 1340 &addrs[1].sin6_addr, addrs[1].sin6_port, 1341 &addrs[0].sin6_addr, addrs[0].sin6_port, 1342 0, NULL); 1343 } 1344 if (inp == NULL || inp->inp_socket == NULL) { 1345 error = ENOENT; 1346 goto out; 1347 } 1348 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1349 out: 1350 crit_exit(); 1351 return (error); 1352 } 1353 1354 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1355 0, 0, 1356 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1357 #endif 1358 1359 struct netmsg_tcp_notify { 1360 struct netmsg_base base; 1361 void (*nm_notify)(struct inpcb *, int); 1362 struct in_addr nm_faddr; 1363 int nm_arg; 1364 }; 1365 1366 static void 1367 tcp_notifyall_oncpu(netmsg_t msg) 1368 { 1369 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1370 int nextcpu; 1371 1372 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr, 1373 nm->nm_arg, nm->nm_notify); 1374 1375 nextcpu = mycpuid + 1; 1376 if (nextcpu < ncpus2) 1377 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg); 1378 else 1379 lwkt_replymsg(&nm->base.lmsg, 0); 1380 } 1381 1382 void 1383 tcp_ctlinput(netmsg_t msg) 1384 { 1385 int cmd = msg->ctlinput.nm_cmd; 1386 struct sockaddr *sa = msg->ctlinput.nm_arg; 1387 struct ip *ip = msg->ctlinput.nm_extra; 1388 struct tcphdr *th; 1389 struct in_addr faddr; 1390 struct inpcb *inp; 1391 struct tcpcb *tp; 1392 void (*notify)(struct inpcb *, int) = tcp_notify; 1393 tcp_seq icmpseq; 1394 int arg, cpu; 1395 1396 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1397 goto done; 1398 } 1399 1400 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1401 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1402 goto done; 1403 1404 arg = inetctlerrmap[cmd]; 1405 if (cmd == PRC_QUENCH) { 1406 notify = tcp_quench; 1407 } else if (icmp_may_rst && 1408 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1409 cmd == PRC_UNREACH_PORT || 1410 cmd == PRC_TIMXCEED_INTRANS) && 1411 ip != NULL) { 1412 notify = tcp_drop_syn_sent; 1413 } else if (cmd == PRC_MSGSIZE) { 1414 struct icmp *icmp = (struct icmp *) 1415 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1416 1417 arg = ntohs(icmp->icmp_nextmtu); 1418 notify = tcp_mtudisc; 1419 } else if (PRC_IS_REDIRECT(cmd)) { 1420 ip = NULL; 1421 notify = in_rtchange; 1422 } else if (cmd == PRC_HOSTDEAD) { 1423 ip = NULL; 1424 } 1425 1426 if (ip != NULL) { 1427 crit_enter(); 1428 th = (struct tcphdr *)((caddr_t)ip + 1429 (IP_VHL_HL(ip->ip_vhl) << 2)); 1430 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1431 ip->ip_src.s_addr, th->th_sport); 1432 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1433 ip->ip_src, th->th_sport, 0, NULL); 1434 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1435 icmpseq = htonl(th->th_seq); 1436 tp = intotcpcb(inp); 1437 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1438 SEQ_LT(icmpseq, tp->snd_max)) 1439 (*notify)(inp, arg); 1440 } else { 1441 struct in_conninfo inc; 1442 1443 inc.inc_fport = th->th_dport; 1444 inc.inc_lport = th->th_sport; 1445 inc.inc_faddr = faddr; 1446 inc.inc_laddr = ip->ip_src; 1447 #ifdef INET6 1448 inc.inc_isipv6 = 0; 1449 #endif 1450 syncache_unreach(&inc, th); 1451 } 1452 crit_exit(); 1453 } else { 1454 struct netmsg_tcp_notify *nm; 1455 1456 KKASSERT(&curthread->td_msgport == netisr_cpuport(0)); 1457 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1458 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1459 0, tcp_notifyall_oncpu); 1460 nm->nm_faddr = faddr; 1461 nm->nm_arg = arg; 1462 nm->nm_notify = notify; 1463 1464 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg); 1465 } 1466 done: 1467 lwkt_replymsg(&msg->lmsg, 0); 1468 } 1469 1470 #ifdef INET6 1471 1472 void 1473 tcp6_ctlinput(netmsg_t msg) 1474 { 1475 int cmd = msg->ctlinput.nm_cmd; 1476 struct sockaddr *sa = msg->ctlinput.nm_arg; 1477 void *d = msg->ctlinput.nm_extra; 1478 struct tcphdr th; 1479 void (*notify) (struct inpcb *, int) = tcp_notify; 1480 struct ip6_hdr *ip6; 1481 struct mbuf *m; 1482 struct ip6ctlparam *ip6cp = NULL; 1483 const struct sockaddr_in6 *sa6_src = NULL; 1484 int off; 1485 struct tcp_portonly { 1486 u_int16_t th_sport; 1487 u_int16_t th_dport; 1488 } *thp; 1489 int arg; 1490 1491 if (sa->sa_family != AF_INET6 || 1492 sa->sa_len != sizeof(struct sockaddr_in6)) { 1493 goto out; 1494 } 1495 1496 arg = 0; 1497 if (cmd == PRC_QUENCH) 1498 notify = tcp_quench; 1499 else if (cmd == PRC_MSGSIZE) { 1500 struct ip6ctlparam *ip6cp = d; 1501 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1502 1503 arg = ntohl(icmp6->icmp6_mtu); 1504 notify = tcp_mtudisc; 1505 } else if (!PRC_IS_REDIRECT(cmd) && 1506 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1507 goto out; 1508 } 1509 1510 /* if the parameter is from icmp6, decode it. */ 1511 if (d != NULL) { 1512 ip6cp = (struct ip6ctlparam *)d; 1513 m = ip6cp->ip6c_m; 1514 ip6 = ip6cp->ip6c_ip6; 1515 off = ip6cp->ip6c_off; 1516 sa6_src = ip6cp->ip6c_src; 1517 } else { 1518 m = NULL; 1519 ip6 = NULL; 1520 off = 0; /* fool gcc */ 1521 sa6_src = &sa6_any; 1522 } 1523 1524 if (ip6 != NULL) { 1525 struct in_conninfo inc; 1526 /* 1527 * XXX: We assume that when IPV6 is non NULL, 1528 * M and OFF are valid. 1529 */ 1530 1531 /* check if we can safely examine src and dst ports */ 1532 if (m->m_pkthdr.len < off + sizeof *thp) 1533 goto out; 1534 1535 bzero(&th, sizeof th); 1536 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1537 1538 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1539 (struct sockaddr *)ip6cp->ip6c_src, 1540 th.th_sport, cmd, arg, notify); 1541 1542 inc.inc_fport = th.th_dport; 1543 inc.inc_lport = th.th_sport; 1544 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1545 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1546 inc.inc_isipv6 = 1; 1547 syncache_unreach(&inc, &th); 1548 } else { 1549 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1550 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1551 } 1552 out: 1553 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1554 } 1555 1556 #endif 1557 1558 /* 1559 * Following is where TCP initial sequence number generation occurs. 1560 * 1561 * There are two places where we must use initial sequence numbers: 1562 * 1. In SYN-ACK packets. 1563 * 2. In SYN packets. 1564 * 1565 * All ISNs for SYN-ACK packets are generated by the syncache. See 1566 * tcp_syncache.c for details. 1567 * 1568 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1569 * depends on this property. In addition, these ISNs should be 1570 * unguessable so as to prevent connection hijacking. To satisfy 1571 * the requirements of this situation, the algorithm outlined in 1572 * RFC 1948 is used to generate sequence numbers. 1573 * 1574 * Implementation details: 1575 * 1576 * Time is based off the system timer, and is corrected so that it 1577 * increases by one megabyte per second. This allows for proper 1578 * recycling on high speed LANs while still leaving over an hour 1579 * before rollover. 1580 * 1581 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1582 * between seeding of isn_secret. This is normally set to zero, 1583 * as reseeding should not be necessary. 1584 * 1585 */ 1586 1587 #define ISN_BYTES_PER_SECOND 1048576 1588 1589 u_char isn_secret[32]; 1590 int isn_last_reseed; 1591 MD5_CTX isn_ctx; 1592 1593 tcp_seq 1594 tcp_new_isn(struct tcpcb *tp) 1595 { 1596 u_int32_t md5_buffer[4]; 1597 tcp_seq new_isn; 1598 1599 /* Seed if this is the first use, reseed if requested. */ 1600 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1601 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1602 < (u_int)ticks))) { 1603 read_random_unlimited(&isn_secret, sizeof isn_secret); 1604 isn_last_reseed = ticks; 1605 } 1606 1607 /* Compute the md5 hash and return the ISN. */ 1608 MD5Init(&isn_ctx); 1609 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1610 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1611 #ifdef INET6 1612 if (tp->t_inpcb->inp_vflag & INP_IPV6) { 1613 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1614 sizeof(struct in6_addr)); 1615 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1616 sizeof(struct in6_addr)); 1617 } else 1618 #endif 1619 { 1620 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1621 sizeof(struct in_addr)); 1622 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1623 sizeof(struct in_addr)); 1624 } 1625 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1626 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1627 new_isn = (tcp_seq) md5_buffer[0]; 1628 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1629 return (new_isn); 1630 } 1631 1632 /* 1633 * When a source quench is received, close congestion window 1634 * to one segment. We will gradually open it again as we proceed. 1635 */ 1636 void 1637 tcp_quench(struct inpcb *inp, int error) 1638 { 1639 struct tcpcb *tp = intotcpcb(inp); 1640 1641 if (tp != NULL) { 1642 tp->snd_cwnd = tp->t_maxseg; 1643 tp->snd_wacked = 0; 1644 } 1645 } 1646 1647 /* 1648 * When a specific ICMP unreachable message is received and the 1649 * connection state is SYN-SENT, drop the connection. This behavior 1650 * is controlled by the icmp_may_rst sysctl. 1651 */ 1652 void 1653 tcp_drop_syn_sent(struct inpcb *inp, int error) 1654 { 1655 struct tcpcb *tp = intotcpcb(inp); 1656 1657 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT)) 1658 tcp_drop(tp, error); 1659 } 1660 1661 /* 1662 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1663 * based on the new value in the route. Also nudge TCP to send something, 1664 * since we know the packet we just sent was dropped. 1665 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1666 */ 1667 void 1668 tcp_mtudisc(struct inpcb *inp, int mtu) 1669 { 1670 struct tcpcb *tp = intotcpcb(inp); 1671 struct rtentry *rt; 1672 struct socket *so = inp->inp_socket; 1673 int maxopd, mss; 1674 #ifdef INET6 1675 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0); 1676 #else 1677 const boolean_t isipv6 = FALSE; 1678 #endif 1679 1680 if (tp == NULL) 1681 return; 1682 1683 /* 1684 * If no MTU is provided in the ICMP message, use the 1685 * next lower likely value, as specified in RFC 1191. 1686 */ 1687 if (mtu == 0) { 1688 int oldmtu; 1689 1690 oldmtu = tp->t_maxopd + 1691 (isipv6 ? 1692 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1693 sizeof(struct tcpiphdr)); 1694 mtu = ip_next_mtu(oldmtu, 0); 1695 } 1696 1697 if (isipv6) 1698 rt = tcp_rtlookup6(&inp->inp_inc); 1699 else 1700 rt = tcp_rtlookup(&inp->inp_inc); 1701 if (rt != NULL) { 1702 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1703 mtu = rt->rt_rmx.rmx_mtu; 1704 1705 maxopd = mtu - 1706 (isipv6 ? 1707 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1708 sizeof(struct tcpiphdr)); 1709 1710 /* 1711 * XXX - The following conditional probably violates the TCP 1712 * spec. The problem is that, since we don't know the 1713 * other end's MSS, we are supposed to use a conservative 1714 * default. But, if we do that, then MTU discovery will 1715 * never actually take place, because the conservative 1716 * default is much less than the MTUs typically seen 1717 * on the Internet today. For the moment, we'll sweep 1718 * this under the carpet. 1719 * 1720 * The conservative default might not actually be a problem 1721 * if the only case this occurs is when sending an initial 1722 * SYN with options and data to a host we've never talked 1723 * to before. Then, they will reply with an MSS value which 1724 * will get recorded and the new parameters should get 1725 * recomputed. For Further Study. 1726 */ 1727 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1728 maxopd = rt->rt_rmx.rmx_mssopt; 1729 } else 1730 maxopd = mtu - 1731 (isipv6 ? 1732 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1733 sizeof(struct tcpiphdr)); 1734 1735 if (tp->t_maxopd <= maxopd) 1736 return; 1737 tp->t_maxopd = maxopd; 1738 1739 mss = maxopd; 1740 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1741 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1742 mss -= TCPOLEN_TSTAMP_APPA; 1743 1744 /* round down to multiple of MCLBYTES */ 1745 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1746 if (mss > MCLBYTES) 1747 mss &= ~(MCLBYTES - 1); 1748 #else 1749 if (mss > MCLBYTES) 1750 mss = (mss / MCLBYTES) * MCLBYTES; 1751 #endif 1752 1753 if (so->so_snd.ssb_hiwat < mss) 1754 mss = so->so_snd.ssb_hiwat; 1755 1756 tp->t_maxseg = mss; 1757 tp->t_rtttime = 0; 1758 tp->snd_nxt = tp->snd_una; 1759 tcp_output(tp); 1760 tcpstat.tcps_mturesent++; 1761 } 1762 1763 /* 1764 * Look-up the routing entry to the peer of this inpcb. If no route 1765 * is found and it cannot be allocated the return NULL. This routine 1766 * is called by TCP routines that access the rmx structure and by tcp_mss 1767 * to get the interface MTU. 1768 */ 1769 struct rtentry * 1770 tcp_rtlookup(struct in_conninfo *inc) 1771 { 1772 struct route *ro = &inc->inc_route; 1773 1774 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1775 /* No route yet, so try to acquire one */ 1776 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1777 /* 1778 * unused portions of the structure MUST be zero'd 1779 * out because rtalloc() treats it as opaque data 1780 */ 1781 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1782 ro->ro_dst.sa_family = AF_INET; 1783 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1784 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1785 inc->inc_faddr; 1786 rtalloc(ro); 1787 } 1788 } 1789 return (ro->ro_rt); 1790 } 1791 1792 #ifdef INET6 1793 struct rtentry * 1794 tcp_rtlookup6(struct in_conninfo *inc) 1795 { 1796 struct route_in6 *ro6 = &inc->inc6_route; 1797 1798 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1799 /* No route yet, so try to acquire one */ 1800 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1801 /* 1802 * unused portions of the structure MUST be zero'd 1803 * out because rtalloc() treats it as opaque data 1804 */ 1805 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1806 ro6->ro_dst.sin6_family = AF_INET6; 1807 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1808 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1809 rtalloc((struct route *)ro6); 1810 } 1811 } 1812 return (ro6->ro_rt); 1813 } 1814 #endif 1815 1816 #ifdef IPSEC 1817 /* compute ESP/AH header size for TCP, including outer IP header. */ 1818 size_t 1819 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1820 { 1821 struct inpcb *inp; 1822 struct mbuf *m; 1823 size_t hdrsiz; 1824 struct ip *ip; 1825 struct tcphdr *th; 1826 1827 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1828 return (0); 1829 MGETHDR(m, MB_DONTWAIT, MT_DATA); 1830 if (!m) 1831 return (0); 1832 1833 #ifdef INET6 1834 if (inp->inp_vflag & INP_IPV6) { 1835 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1836 1837 th = (struct tcphdr *)(ip6 + 1); 1838 m->m_pkthdr.len = m->m_len = 1839 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1840 tcp_fillheaders(tp, ip6, th, FALSE); 1841 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1842 } else 1843 #endif 1844 { 1845 ip = mtod(m, struct ip *); 1846 th = (struct tcphdr *)(ip + 1); 1847 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1848 tcp_fillheaders(tp, ip, th, FALSE); 1849 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1850 } 1851 1852 m_free(m); 1853 return (hdrsiz); 1854 } 1855 #endif 1856 1857 /* 1858 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1859 * 1860 * This code attempts to calculate the bandwidth-delay product as a 1861 * means of determining the optimal window size to maximize bandwidth, 1862 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1863 * routers. This code also does a fairly good job keeping RTTs in check 1864 * across slow links like modems. We implement an algorithm which is very 1865 * similar (but not meant to be) TCP/Vegas. The code operates on the 1866 * transmitter side of a TCP connection and so only effects the transmit 1867 * side of the connection. 1868 * 1869 * BACKGROUND: TCP makes no provision for the management of buffer space 1870 * at the end points or at the intermediate routers and switches. A TCP 1871 * stream, whether using NewReno or not, will eventually buffer as 1872 * many packets as it is able and the only reason this typically works is 1873 * due to the fairly small default buffers made available for a connection 1874 * (typicaly 16K or 32K). As machines use larger windows and/or window 1875 * scaling it is now fairly easy for even a single TCP connection to blow-out 1876 * all available buffer space not only on the local interface, but on 1877 * intermediate routers and switches as well. NewReno makes a misguided 1878 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1879 * then backing off, then steadily increasing the window again until another 1880 * failure occurs, ad-infinitum. This results in terrible oscillation that 1881 * is only made worse as network loads increase and the idea of intentionally 1882 * blowing out network buffers is, frankly, a terrible way to manage network 1883 * resources. 1884 * 1885 * It is far better to limit the transmit window prior to the failure 1886 * condition being achieved. There are two general ways to do this: First 1887 * you can 'scan' through different transmit window sizes and locate the 1888 * point where the RTT stops increasing, indicating that you have filled the 1889 * pipe, then scan backwards until you note that RTT stops decreasing, then 1890 * repeat ad-infinitum. This method works in principle but has severe 1891 * implementation issues due to RTT variances, timer granularity, and 1892 * instability in the algorithm which can lead to many false positives and 1893 * create oscillations as well as interact badly with other TCP streams 1894 * implementing the same algorithm. 1895 * 1896 * The second method is to limit the window to the bandwidth delay product 1897 * of the link. This is the method we implement. RTT variances and our 1898 * own manipulation of the congestion window, bwnd, can potentially 1899 * destabilize the algorithm. For this reason we have to stabilize the 1900 * elements used to calculate the window. We do this by using the minimum 1901 * observed RTT, the long term average of the observed bandwidth, and 1902 * by adding two segments worth of slop. It isn't perfect but it is able 1903 * to react to changing conditions and gives us a very stable basis on 1904 * which to extend the algorithm. 1905 */ 1906 void 1907 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1908 { 1909 u_long bw; 1910 u_long ibw; 1911 u_long bwnd; 1912 int save_ticks; 1913 int delta_ticks; 1914 1915 /* 1916 * If inflight_enable is disabled in the middle of a tcp connection, 1917 * make sure snd_bwnd is effectively disabled. 1918 */ 1919 if (!tcp_inflight_enable) { 1920 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1921 tp->snd_bandwidth = 0; 1922 return; 1923 } 1924 1925 /* 1926 * Validate the delta time. If a connection is new or has been idle 1927 * a long time we have to reset the bandwidth calculator. 1928 */ 1929 save_ticks = ticks; 1930 cpu_ccfence(); 1931 delta_ticks = save_ticks - tp->t_bw_rtttime; 1932 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1933 tp->t_bw_rtttime = save_ticks; 1934 tp->t_bw_rtseq = ack_seq; 1935 if (tp->snd_bandwidth == 0) 1936 tp->snd_bandwidth = tcp_inflight_min; 1937 return; 1938 } 1939 1940 /* 1941 * A delta of at least 1 tick is required. Waiting 2 ticks will 1942 * result in better (bw) accuracy. More than that and the ramp-up 1943 * will be too slow. 1944 */ 1945 if (delta_ticks == 0 || delta_ticks == 1) 1946 return; 1947 1948 /* 1949 * Sanity check, plus ignore pure window update acks. 1950 */ 1951 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1952 return; 1953 1954 /* 1955 * Figure out the bandwidth. Due to the tick granularity this 1956 * is a very rough number and it MUST be averaged over a fairly 1957 * long period of time. XXX we need to take into account a link 1958 * that is not using all available bandwidth, but for now our 1959 * slop will ramp us up if this case occurs and the bandwidth later 1960 * increases. 1961 */ 1962 ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 1963 tp->t_bw_rtttime = save_ticks; 1964 tp->t_bw_rtseq = ack_seq; 1965 bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4; 1966 1967 tp->snd_bandwidth = bw; 1968 1969 /* 1970 * Calculate the semi-static bandwidth delay product, plus two maximal 1971 * segments. The additional slop puts us squarely in the sweet 1972 * spot and also handles the bandwidth run-up case. Without the 1973 * slop we could be locking ourselves into a lower bandwidth. 1974 * 1975 * At very high speeds the bw calculation can become overly sensitive 1976 * and error prone when delta_ticks is low (e.g. usually 1). To deal 1977 * with the problem the stab must be scaled to the bw. A stab of 50 1978 * (the default) increases the bw for the purposes of the bwnd 1979 * calculation by 5%. 1980 * 1981 * Situations Handled: 1982 * (1) Prevents over-queueing of packets on LANs, especially on 1983 * high speed LANs, allowing larger TCP buffers to be 1984 * specified, and also does a good job preventing 1985 * over-queueing of packets over choke points like modems 1986 * (at least for the transmit side). 1987 * 1988 * (2) Is able to handle changing network loads (bandwidth 1989 * drops so bwnd drops, bandwidth increases so bwnd 1990 * increases). 1991 * 1992 * (3) Theoretically should stabilize in the face of multiple 1993 * connections implementing the same algorithm (this may need 1994 * a little work). 1995 * 1996 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1997 * be adjusted with a sysctl but typically only needs to be on 1998 * very slow connections. A value no smaller then 5 should 1999 * be used, but only reduce this default if you have no other 2000 * choice. 2001 */ 2002 2003 #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt) 2004 bw += bw * tcp_inflight_stab / 1000; 2005 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 2006 (int)tp->t_maxseg * 2; 2007 #undef USERTT 2008 2009 if (tcp_inflight_debug > 0) { 2010 static int ltime; 2011 if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) { 2012 ltime = save_ticks; 2013 kprintf("%p ibw %ld bw %ld rttvar %d srtt %d " 2014 "bwnd %ld delta %d snd_win %ld\n", 2015 tp, ibw, bw, tp->t_rttvar, tp->t_srtt, 2016 bwnd, delta_ticks, tp->snd_wnd); 2017 } 2018 } 2019 if ((long)bwnd < tcp_inflight_min) 2020 bwnd = tcp_inflight_min; 2021 if (bwnd > tcp_inflight_max) 2022 bwnd = tcp_inflight_max; 2023 if ((long)bwnd < tp->t_maxseg * 2) 2024 bwnd = tp->t_maxseg * 2; 2025 tp->snd_bwnd = bwnd; 2026 } 2027 2028 static void 2029 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs) 2030 { 2031 struct rtentry *rt; 2032 struct inpcb *inp = tp->t_inpcb; 2033 #ifdef INET6 2034 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE); 2035 #else 2036 const boolean_t isipv6 = FALSE; 2037 #endif 2038 2039 /* XXX */ 2040 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT) 2041 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 2042 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT) 2043 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 2044 2045 if (isipv6) 2046 rt = tcp_rtlookup6(&inp->inp_inc); 2047 else 2048 rt = tcp_rtlookup(&inp->inp_inc); 2049 if (rt == NULL || 2050 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT || 2051 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) { 2052 *maxsegs = tcp_iw_maxsegs; 2053 *capsegs = tcp_iw_capsegs; 2054 return; 2055 } 2056 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs; 2057 *capsegs = rt->rt_rmx.rmx_iwcapsegs; 2058 } 2059 2060 u_long 2061 tcp_initial_window(struct tcpcb *tp) 2062 { 2063 if (tcp_do_rfc3390) { 2064 /* 2065 * RFC3390: 2066 * "If the SYN or SYN/ACK is lost, the initial window 2067 * used by a sender after a correctly transmitted SYN 2068 * MUST be one segment consisting of MSS bytes." 2069 * 2070 * However, we do something a little bit more aggressive 2071 * then RFC3390 here: 2072 * - Only if time spent in the SYN or SYN|ACK retransmition 2073 * >= 3 seconds, the IW is reduced. We do this mainly 2074 * because when RFC3390 is published, the initial RTO is 2075 * still 3 seconds (the threshold we test here), while 2076 * after RFC6298, the initial RTO is 1 second. This 2077 * behaviour probably still falls within the spirit of 2078 * RFC3390. 2079 * - When IW is reduced, 2*MSS is used instead of 1*MSS. 2080 * Mainly to avoid sender and receiver deadlock until 2081 * delayed ACK timer expires. And even RFC2581 does not 2082 * try to reduce IW upon SYN or SYN|ACK retransmition 2083 * timeout. 2084 * 2085 * See also: 2086 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03 2087 */ 2088 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) { 2089 return (2 * tp->t_maxseg); 2090 } else { 2091 u_long maxsegs, capsegs; 2092 2093 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs); 2094 return min(maxsegs * tp->t_maxseg, 2095 max(2 * tp->t_maxseg, capsegs * 1460)); 2096 } 2097 } else { 2098 /* 2099 * Even RFC2581 (back to 1999) allows 2*SMSS IW. 2100 * 2101 * Mainly to avoid sender and receiver deadlock 2102 * until delayed ACK timer expires. 2103 */ 2104 return (2 * tp->t_maxseg); 2105 } 2106 } 2107 2108 #ifdef TCP_SIGNATURE 2109 /* 2110 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2111 * 2112 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2113 * When called from tcp_input(), we can be sure that th_sum has been 2114 * zeroed out and verified already. 2115 * 2116 * Return 0 if successful, otherwise return -1. 2117 * 2118 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2119 * search with the destination IP address, and a 'magic SPI' to be 2120 * determined by the application. This is hardcoded elsewhere to 1179 2121 * right now. Another branch of this code exists which uses the SPD to 2122 * specify per-application flows but it is unstable. 2123 */ 2124 int 2125 tcpsignature_compute( 2126 struct mbuf *m, /* mbuf chain */ 2127 int len, /* length of TCP data */ 2128 int optlen, /* length of TCP options */ 2129 u_char *buf, /* storage for MD5 digest */ 2130 u_int direction) /* direction of flow */ 2131 { 2132 struct ippseudo ippseudo; 2133 MD5_CTX ctx; 2134 int doff; 2135 struct ip *ip; 2136 struct ipovly *ipovly; 2137 struct secasvar *sav; 2138 struct tcphdr *th; 2139 #ifdef INET6 2140 struct ip6_hdr *ip6; 2141 struct in6_addr in6; 2142 uint32_t plen; 2143 uint16_t nhdr; 2144 #endif /* INET6 */ 2145 u_short savecsum; 2146 2147 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 2148 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 2149 /* 2150 * Extract the destination from the IP header in the mbuf. 2151 */ 2152 ip = mtod(m, struct ip *); 2153 #ifdef INET6 2154 ip6 = NULL; /* Make the compiler happy. */ 2155 #endif /* INET6 */ 2156 /* 2157 * Look up an SADB entry which matches the address found in 2158 * the segment. 2159 */ 2160 switch (IP_VHL_V(ip->ip_vhl)) { 2161 case IPVERSION: 2162 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2163 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2164 break; 2165 #ifdef INET6 2166 case (IPV6_VERSION >> 4): 2167 ip6 = mtod(m, struct ip6_hdr *); 2168 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2169 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2170 break; 2171 #endif /* INET6 */ 2172 default: 2173 return (EINVAL); 2174 /* NOTREACHED */ 2175 break; 2176 } 2177 if (sav == NULL) { 2178 kprintf("%s: SADB lookup failed\n", __func__); 2179 return (EINVAL); 2180 } 2181 MD5Init(&ctx); 2182 2183 /* 2184 * Step 1: Update MD5 hash with IP pseudo-header. 2185 * 2186 * XXX The ippseudo header MUST be digested in network byte order, 2187 * or else we'll fail the regression test. Assume all fields we've 2188 * been doing arithmetic on have been in host byte order. 2189 * XXX One cannot depend on ipovly->ih_len here. When called from 2190 * tcp_output(), the underlying ip_len member has not yet been set. 2191 */ 2192 switch (IP_VHL_V(ip->ip_vhl)) { 2193 case IPVERSION: 2194 ipovly = (struct ipovly *)ip; 2195 ippseudo.ippseudo_src = ipovly->ih_src; 2196 ippseudo.ippseudo_dst = ipovly->ih_dst; 2197 ippseudo.ippseudo_pad = 0; 2198 ippseudo.ippseudo_p = IPPROTO_TCP; 2199 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2200 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2201 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2202 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2203 break; 2204 #ifdef INET6 2205 /* 2206 * RFC 2385, 2.0 Proposal 2207 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2208 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2209 * extended next header value (to form 32 bits), and 32-bit segment 2210 * length. 2211 * Note: Upper-Layer Packet Length comes before Next Header. 2212 */ 2213 case (IPV6_VERSION >> 4): 2214 in6 = ip6->ip6_src; 2215 in6_clearscope(&in6); 2216 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2217 in6 = ip6->ip6_dst; 2218 in6_clearscope(&in6); 2219 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2220 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2221 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2222 nhdr = 0; 2223 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2224 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2225 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2226 nhdr = IPPROTO_TCP; 2227 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2228 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2229 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2230 break; 2231 #endif /* INET6 */ 2232 default: 2233 return (EINVAL); 2234 /* NOTREACHED */ 2235 break; 2236 } 2237 /* 2238 * Step 2: Update MD5 hash with TCP header, excluding options. 2239 * The TCP checksum must be set to zero. 2240 */ 2241 savecsum = th->th_sum; 2242 th->th_sum = 0; 2243 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2244 th->th_sum = savecsum; 2245 /* 2246 * Step 3: Update MD5 hash with TCP segment data. 2247 * Use m_apply() to avoid an early m_pullup(). 2248 */ 2249 if (len > 0) 2250 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2251 /* 2252 * Step 4: Update MD5 hash with shared secret. 2253 */ 2254 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2255 MD5Final(buf, &ctx); 2256 key_sa_recordxfer(sav, m); 2257 key_freesav(sav); 2258 return (0); 2259 } 2260 2261 int 2262 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2263 { 2264 2265 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2266 return (0); 2267 } 2268 #endif /* TCP_SIGNATURE */ 2269