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