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 * $DragonFly: src/sys/netinet/tcp_subr.c,v 1.63 2008/11/11 10:46:58 sephe Exp $ 69 */ 70 71 #include "opt_compat.h" 72 #include "opt_inet.h" 73 #include "opt_inet6.h" 74 #include "opt_ipsec.h" 75 #include "opt_tcpdebug.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/callout.h> 80 #include <sys/kernel.h> 81 #include <sys/sysctl.h> 82 #include <sys/malloc.h> 83 #include <sys/mpipe.h> 84 #include <sys/mbuf.h> 85 #ifdef INET6 86 #include <sys/domain.h> 87 #endif 88 #include <sys/proc.h> 89 #include <sys/priv.h> 90 #include <sys/socket.h> 91 #include <sys/socketvar.h> 92 #include <sys/protosw.h> 93 #include <sys/random.h> 94 #include <sys/in_cksum.h> 95 #include <sys/ktr.h> 96 97 #include <net/route.h> 98 #include <net/if.h> 99 #include <net/netisr.h> 100 101 #define _IP_VHL 102 #include <netinet/in.h> 103 #include <netinet/in_systm.h> 104 #include <netinet/ip.h> 105 #include <netinet/ip6.h> 106 #include <netinet/in_pcb.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet/in_var.h> 109 #include <netinet/ip_var.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet/ip_icmp.h> 112 #ifdef INET6 113 #include <netinet/icmp6.h> 114 #endif 115 #include <netinet/tcp.h> 116 #include <netinet/tcp_fsm.h> 117 #include <netinet/tcp_seq.h> 118 #include <netinet/tcp_timer.h> 119 #include <netinet/tcp_timer2.h> 120 #include <netinet/tcp_var.h> 121 #include <netinet6/tcp6_var.h> 122 #include <netinet/tcpip.h> 123 #ifdef TCPDEBUG 124 #include <netinet/tcp_debug.h> 125 #endif 126 #include <netinet6/ip6protosw.h> 127 128 #ifdef IPSEC 129 #include <netinet6/ipsec.h> 130 #include <netproto/key/key.h> 131 #ifdef INET6 132 #include <netinet6/ipsec6.h> 133 #endif 134 #endif 135 136 #ifdef FAST_IPSEC 137 #include <netproto/ipsec/ipsec.h> 138 #ifdef INET6 139 #include <netproto/ipsec/ipsec6.h> 140 #endif 141 #define IPSEC 142 #endif 143 144 #include <sys/md5.h> 145 #include <machine/smp.h> 146 147 #include <sys/msgport2.h> 148 #include <sys/mplock2.h> 149 #include <net/netmsg2.h> 150 151 #if !defined(KTR_TCP) 152 #define KTR_TCP KTR_ALL 153 #endif 154 KTR_INFO_MASTER(tcp); 155 /* 156 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 157 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 158 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 159 */ 160 #define logtcp(name) KTR_LOG(tcp_ ## name) 161 162 struct inpcbinfo tcbinfo[MAXCPU]; 163 struct tcpcbackqhead tcpcbackq[MAXCPU]; 164 165 static struct lwkt_token tcp_port_token = 166 LWKT_TOKEN_MP_INITIALIZER(tcp_port_token); 167 168 int tcp_mssdflt = TCP_MSS; 169 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 170 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 171 172 #ifdef INET6 173 int tcp_v6mssdflt = TCP6_MSS; 174 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 175 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 176 #endif 177 178 /* 179 * Minimum MSS we accept and use. This prevents DoS attacks where 180 * we are forced to a ridiculous low MSS like 20 and send hundreds 181 * of packets instead of one. The effect scales with the available 182 * bandwidth and quickly saturates the CPU and network interface 183 * with packet generation and sending. Set to zero to disable MINMSS 184 * checking. This setting prevents us from sending too small packets. 185 */ 186 int tcp_minmss = TCP_MINMSS; 187 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 188 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 189 190 #if 0 191 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 192 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 193 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 194 #endif 195 196 int tcp_do_rfc1323 = 1; 197 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 198 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 199 200 static int tcp_tcbhashsize = 0; 201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 202 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 203 204 static int do_tcpdrain = 1; 205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 206 "Enable tcp_drain routine for extra help when low on mbufs"); 207 208 static int icmp_may_rst = 1; 209 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 210 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 211 212 static int tcp_isn_reseed_interval = 0; 213 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 214 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 215 216 /* 217 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 218 * by default, but with generous values which should allow maximal 219 * bandwidth. In particular, the slop defaults to 50 (5 packets). 220 * 221 * The reason for doing this is that the limiter is the only mechanism we 222 * have which seems to do a really good job preventing receiver RX rings 223 * on network interfaces from getting blown out. Even though GigE/10GigE 224 * is supposed to flow control it looks like either it doesn't actually 225 * do it or Open Source drivers do not properly enable it. 226 * 227 * People using the limiter to reduce bottlenecks on slower WAN connections 228 * should set the slop to 20 (2 packets). 229 */ 230 static int tcp_inflight_enable = 1; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 232 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 233 234 static int tcp_inflight_debug = 0; 235 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 236 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 237 238 static int tcp_inflight_min = 6144; 239 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 240 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 241 242 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 243 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 244 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 245 246 static int tcp_inflight_stab = 50; 247 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 248 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)"); 249 250 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 251 static struct malloc_pipe tcptemp_mpipe; 252 253 static void tcp_willblock(void); 254 static void tcp_notify (struct inpcb *, int); 255 256 struct tcp_stats tcpstats_percpu[MAXCPU]; 257 #ifdef SMP 258 static int 259 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 260 { 261 int cpu, error = 0; 262 263 for (cpu = 0; cpu < ncpus; ++cpu) { 264 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 265 sizeof(struct tcp_stats)))) 266 break; 267 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 268 sizeof(struct tcp_stats)))) 269 break; 270 } 271 272 return (error); 273 } 274 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 275 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 276 #else 277 SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW, 278 &tcpstat, tcp_stats, "TCP statistics"); 279 #endif 280 281 /* 282 * Target size of TCP PCB hash tables. Must be a power of two. 283 * 284 * Note that this can be overridden by the kernel environment 285 * variable net.inet.tcp.tcbhashsize 286 */ 287 #ifndef TCBHASHSIZE 288 #define TCBHASHSIZE 512 289 #endif 290 291 /* 292 * This is the actual shape of what we allocate using the zone 293 * allocator. Doing it this way allows us to protect both structures 294 * using the same generation count, and also eliminates the overhead 295 * of allocating tcpcbs separately. By hiding the structure here, 296 * we avoid changing most of the rest of the code (although it needs 297 * to be changed, eventually, for greater efficiency). 298 */ 299 #define ALIGNMENT 32 300 #define ALIGNM1 (ALIGNMENT - 1) 301 struct inp_tp { 302 union { 303 struct inpcb inp; 304 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 305 } inp_tp_u; 306 struct tcpcb tcb; 307 struct tcp_callout inp_tp_rexmt; 308 struct tcp_callout inp_tp_persist; 309 struct tcp_callout inp_tp_keep; 310 struct tcp_callout inp_tp_2msl; 311 struct tcp_callout inp_tp_delack; 312 struct netmsg_tcp_timer inp_tp_timermsg; 313 }; 314 #undef ALIGNMENT 315 #undef ALIGNM1 316 317 /* 318 * Tcp initialization 319 */ 320 void 321 tcp_init(void) 322 { 323 struct inpcbporthead *porthashbase; 324 struct inpcbinfo *ticb; 325 u_long porthashmask; 326 int hashsize = TCBHASHSIZE; 327 int cpu; 328 329 /* 330 * note: tcptemp is used for keepalives, and it is ok for an 331 * allocation to fail so do not specify MPF_INT. 332 */ 333 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 334 25, -1, 0, NULL); 335 336 tcp_delacktime = TCPTV_DELACK; 337 tcp_keepinit = TCPTV_KEEP_INIT; 338 tcp_keepidle = TCPTV_KEEP_IDLE; 339 tcp_keepintvl = TCPTV_KEEPINTVL; 340 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 341 tcp_msl = TCPTV_MSL; 342 tcp_rexmit_min = TCPTV_MIN; 343 tcp_rexmit_slop = TCPTV_CPU_VAR; 344 345 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 346 if (!powerof2(hashsize)) { 347 kprintf("WARNING: TCB hash size not a power of 2\n"); 348 hashsize = 512; /* safe default */ 349 } 350 tcp_tcbhashsize = hashsize; 351 porthashbase = hashinit(hashsize, M_PCB, &porthashmask); 352 353 for (cpu = 0; cpu < ncpus2; cpu++) { 354 ticb = &tcbinfo[cpu]; 355 in_pcbinfo_init(ticb); 356 ticb->cpu = cpu; 357 ticb->hashbase = hashinit(hashsize, M_PCB, 358 &ticb->hashmask); 359 ticb->porthashbase = porthashbase; 360 ticb->porthashmask = porthashmask; 361 ticb->porttoken = &tcp_port_token; 362 #if 0 363 ticb->porthashbase = hashinit(hashsize, M_PCB, 364 &ticb->porthashmask); 365 #endif 366 ticb->wildcardhashbase = hashinit(hashsize, M_PCB, 367 &ticb->wildcardhashmask); 368 ticb->ipi_size = sizeof(struct inp_tp); 369 TAILQ_INIT(&tcpcbackq[cpu]); 370 } 371 372 tcp_reass_maxseg = nmbclusters / 16; 373 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 374 375 #ifdef INET6 376 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 377 #else 378 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 379 #endif 380 if (max_protohdr < TCP_MINPROTOHDR) 381 max_protohdr = TCP_MINPROTOHDR; 382 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 383 panic("tcp_init"); 384 #undef TCP_MINPROTOHDR 385 386 /* 387 * Initialize TCP statistics counters for each CPU. 388 */ 389 #ifdef SMP 390 for (cpu = 0; cpu < ncpus; ++cpu) { 391 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 392 } 393 #else 394 bzero(&tcpstat, sizeof(struct tcp_stats)); 395 #endif 396 397 syncache_init(); 398 netisr_register_rollup(tcp_willblock); 399 } 400 401 static void 402 tcp_willblock(void) 403 { 404 struct tcpcb *tp; 405 int cpu = mycpu->gd_cpuid; 406 407 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 408 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 409 tp->t_flags &= ~TF_ONOUTPUTQ; 410 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 411 tcp_output(tp); 412 } 413 } 414 415 /* 416 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 417 * tcp_template used to store this data in mbufs, but we now recopy it out 418 * of the tcpcb each time to conserve mbufs. 419 */ 420 void 421 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr) 422 { 423 struct inpcb *inp = tp->t_inpcb; 424 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 425 426 #ifdef INET6 427 if (inp->inp_vflag & INP_IPV6) { 428 struct ip6_hdr *ip6; 429 430 ip6 = (struct ip6_hdr *)ip_ptr; 431 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 432 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 433 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 434 (IPV6_VERSION & IPV6_VERSION_MASK); 435 ip6->ip6_nxt = IPPROTO_TCP; 436 ip6->ip6_plen = sizeof(struct tcphdr); 437 ip6->ip6_src = inp->in6p_laddr; 438 ip6->ip6_dst = inp->in6p_faddr; 439 tcp_hdr->th_sum = 0; 440 } else 441 #endif 442 { 443 struct ip *ip = (struct ip *) ip_ptr; 444 445 ip->ip_vhl = IP_VHL_BORING; 446 ip->ip_tos = 0; 447 ip->ip_len = 0; 448 ip->ip_id = 0; 449 ip->ip_off = 0; 450 ip->ip_ttl = 0; 451 ip->ip_sum = 0; 452 ip->ip_p = IPPROTO_TCP; 453 ip->ip_src = inp->inp_laddr; 454 ip->ip_dst = inp->inp_faddr; 455 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 456 ip->ip_dst.s_addr, 457 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 458 } 459 460 tcp_hdr->th_sport = inp->inp_lport; 461 tcp_hdr->th_dport = inp->inp_fport; 462 tcp_hdr->th_seq = 0; 463 tcp_hdr->th_ack = 0; 464 tcp_hdr->th_x2 = 0; 465 tcp_hdr->th_off = 5; 466 tcp_hdr->th_flags = 0; 467 tcp_hdr->th_win = 0; 468 tcp_hdr->th_urp = 0; 469 } 470 471 /* 472 * Create template to be used to send tcp packets on a connection. 473 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 474 * use for this function is in keepalives, which use tcp_respond. 475 */ 476 struct tcptemp * 477 tcp_maketemplate(struct tcpcb *tp) 478 { 479 struct tcptemp *tmp; 480 481 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 482 return (NULL); 483 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t); 484 return (tmp); 485 } 486 487 void 488 tcp_freetemplate(struct tcptemp *tmp) 489 { 490 mpipe_free(&tcptemp_mpipe, tmp); 491 } 492 493 /* 494 * Send a single message to the TCP at address specified by 495 * the given TCP/IP header. If m == NULL, then we make a copy 496 * of the tcpiphdr at ti and send directly to the addressed host. 497 * This is used to force keep alive messages out using the TCP 498 * template for a connection. If flags are given then we send 499 * a message back to the TCP which originated the * segment ti, 500 * and discard the mbuf containing it and any other attached mbufs. 501 * 502 * In any case the ack and sequence number of the transmitted 503 * segment are as specified by the parameters. 504 * 505 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 506 */ 507 void 508 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 509 tcp_seq ack, tcp_seq seq, int flags) 510 { 511 int tlen; 512 int win = 0; 513 struct route *ro = NULL; 514 struct route sro; 515 struct ip *ip = ipgen; 516 struct tcphdr *nth; 517 int ipflags = 0; 518 struct route_in6 *ro6 = NULL; 519 struct route_in6 sro6; 520 struct ip6_hdr *ip6 = ipgen; 521 boolean_t use_tmpro = TRUE; 522 #ifdef INET6 523 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 524 #else 525 const boolean_t isipv6 = FALSE; 526 #endif 527 528 if (tp != NULL) { 529 if (!(flags & TH_RST)) { 530 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 531 if (win < 0) 532 win = 0; 533 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 534 win = (long)TCP_MAXWIN << tp->rcv_scale; 535 } 536 /* 537 * Don't use the route cache of a listen socket, 538 * it is not MPSAFE; use temporary route cache. 539 */ 540 if (tp->t_state != TCPS_LISTEN) { 541 if (isipv6) 542 ro6 = &tp->t_inpcb->in6p_route; 543 else 544 ro = &tp->t_inpcb->inp_route; 545 use_tmpro = FALSE; 546 } 547 } 548 if (use_tmpro) { 549 if (isipv6) { 550 ro6 = &sro6; 551 bzero(ro6, sizeof *ro6); 552 } else { 553 ro = &sro; 554 bzero(ro, sizeof *ro); 555 } 556 } 557 if (m == NULL) { 558 m = m_gethdr(MB_DONTWAIT, MT_HEADER); 559 if (m == NULL) 560 return; 561 tlen = 0; 562 m->m_data += max_linkhdr; 563 if (isipv6) { 564 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 565 ip6 = mtod(m, struct ip6_hdr *); 566 nth = (struct tcphdr *)(ip6 + 1); 567 } else { 568 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 569 ip = mtod(m, struct ip *); 570 nth = (struct tcphdr *)(ip + 1); 571 } 572 bcopy(th, nth, sizeof(struct tcphdr)); 573 flags = TH_ACK; 574 } else { 575 m_freem(m->m_next); 576 m->m_next = NULL; 577 m->m_data = (caddr_t)ipgen; 578 /* m_len is set later */ 579 tlen = 0; 580 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 581 if (isipv6) { 582 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 583 nth = (struct tcphdr *)(ip6 + 1); 584 } else { 585 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 586 nth = (struct tcphdr *)(ip + 1); 587 } 588 if (th != nth) { 589 /* 590 * this is usually a case when an extension header 591 * exists between the IPv6 header and the 592 * TCP header. 593 */ 594 nth->th_sport = th->th_sport; 595 nth->th_dport = th->th_dport; 596 } 597 xchg(nth->th_dport, nth->th_sport, n_short); 598 #undef xchg 599 } 600 if (isipv6) { 601 ip6->ip6_flow = 0; 602 ip6->ip6_vfc = IPV6_VERSION; 603 ip6->ip6_nxt = IPPROTO_TCP; 604 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 605 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 606 } else { 607 tlen += sizeof(struct tcpiphdr); 608 ip->ip_len = tlen; 609 ip->ip_ttl = ip_defttl; 610 } 611 m->m_len = tlen; 612 m->m_pkthdr.len = tlen; 613 m->m_pkthdr.rcvif = NULL; 614 nth->th_seq = htonl(seq); 615 nth->th_ack = htonl(ack); 616 nth->th_x2 = 0; 617 nth->th_off = sizeof(struct tcphdr) >> 2; 618 nth->th_flags = flags; 619 if (tp != NULL) 620 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 621 else 622 nth->th_win = htons((u_short)win); 623 nth->th_urp = 0; 624 if (isipv6) { 625 nth->th_sum = 0; 626 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 627 sizeof(struct ip6_hdr), 628 tlen - sizeof(struct ip6_hdr)); 629 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 630 (ro6 && ro6->ro_rt) ? 631 ro6->ro_rt->rt_ifp : NULL); 632 } else { 633 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 634 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 635 m->m_pkthdr.csum_flags = CSUM_TCP; 636 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 637 } 638 #ifdef TCPDEBUG 639 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 640 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 641 #endif 642 if (isipv6) { 643 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 644 tp ? tp->t_inpcb : NULL); 645 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 646 RTFREE(ro6->ro_rt); 647 ro6->ro_rt = NULL; 648 } 649 } else { 650 ipflags |= IP_DEBUGROUTE; 651 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 652 if ((ro == &sro) && (ro->ro_rt != NULL)) { 653 RTFREE(ro->ro_rt); 654 ro->ro_rt = NULL; 655 } 656 } 657 } 658 659 /* 660 * Create a new TCP control block, making an 661 * empty reassembly queue and hooking it to the argument 662 * protocol control block. The `inp' parameter must have 663 * come from the zone allocator set up in tcp_init(). 664 */ 665 struct tcpcb * 666 tcp_newtcpcb(struct inpcb *inp) 667 { 668 struct inp_tp *it; 669 struct tcpcb *tp; 670 #ifdef INET6 671 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 672 #else 673 const boolean_t isipv6 = FALSE; 674 #endif 675 676 it = (struct inp_tp *)inp; 677 tp = &it->tcb; 678 bzero(tp, sizeof(struct tcpcb)); 679 LIST_INIT(&tp->t_segq); 680 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 681 682 /* Set up our timeouts. */ 683 tp->tt_rexmt = &it->inp_tp_rexmt; 684 tp->tt_persist = &it->inp_tp_persist; 685 tp->tt_keep = &it->inp_tp_keep; 686 tp->tt_2msl = &it->inp_tp_2msl; 687 tp->tt_delack = &it->inp_tp_delack; 688 tcp_inittimers(tp); 689 690 /* 691 * Zero out timer message. We don't create it here, 692 * since the current CPU may not be the owner of this 693 * inpcb. 694 */ 695 tp->tt_msg = &it->inp_tp_timermsg; 696 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 697 698 if (tcp_do_rfc1323) 699 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP); 700 tp->t_inpcb = inp; /* XXX */ 701 tp->t_state = TCPS_CLOSED; 702 /* 703 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 704 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 705 * reasonable initial retransmit time. 706 */ 707 tp->t_srtt = TCPTV_SRTTBASE; 708 tp->t_rttvar = 709 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 710 tp->t_rttmin = tcp_rexmit_min; 711 tp->t_rxtcur = TCPTV_RTOBASE; 712 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 713 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 714 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 715 tp->t_rcvtime = ticks; 716 /* 717 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 718 * because the socket may be bound to an IPv6 wildcard address, 719 * which may match an IPv4-mapped IPv6 address. 720 */ 721 inp->inp_ip_ttl = ip_defttl; 722 inp->inp_ppcb = tp; 723 tcp_sack_tcpcb_init(tp); 724 return (tp); /* XXX */ 725 } 726 727 /* 728 * Drop a TCP connection, reporting the specified error. 729 * If connection is synchronized, then send a RST to peer. 730 */ 731 struct tcpcb * 732 tcp_drop(struct tcpcb *tp, int error) 733 { 734 struct socket *so = tp->t_inpcb->inp_socket; 735 736 if (TCPS_HAVERCVDSYN(tp->t_state)) { 737 tp->t_state = TCPS_CLOSED; 738 tcp_output(tp); 739 tcpstat.tcps_drops++; 740 } else 741 tcpstat.tcps_conndrops++; 742 if (error == ETIMEDOUT && tp->t_softerror) 743 error = tp->t_softerror; 744 so->so_error = error; 745 return (tcp_close(tp)); 746 } 747 748 #ifdef SMP 749 750 struct netmsg_remwildcard { 751 struct netmsg_base base; 752 struct inpcb *nm_inp; 753 struct inpcbinfo *nm_pcbinfo; 754 #if defined(INET6) 755 int nm_isinet6; 756 #else 757 int nm_unused01; 758 #endif 759 }; 760 761 /* 762 * Wildcard inpcb's on SMP boxes must be removed from all cpus before the 763 * inp can be detached. We do this by cycling through the cpus, ending up 764 * on the cpu controlling the inp last and then doing the disconnect. 765 */ 766 static void 767 in_pcbremwildcardhash_handler(netmsg_t msg) 768 { 769 struct netmsg_remwildcard *nmsg = (struct netmsg_remwildcard *)msg; 770 int cpu; 771 772 cpu = nmsg->nm_pcbinfo->cpu; 773 774 if (cpu == nmsg->nm_inp->inp_pcbinfo->cpu) { 775 /* note: detach removes any wildcard hash entry */ 776 #ifdef INET6 777 if (nmsg->nm_isinet6) 778 in6_pcbdetach(nmsg->nm_inp); 779 else 780 #endif 781 in_pcbdetach(nmsg->nm_inp); 782 lwkt_replymsg(&nmsg->base.lmsg, 0); 783 } else { 784 in_pcbremwildcardhash_oncpu(nmsg->nm_inp, nmsg->nm_pcbinfo); 785 cpu = (cpu + 1) % ncpus2; 786 nmsg->nm_pcbinfo = &tcbinfo[cpu]; 787 lwkt_forwardmsg(cpu_portfn(cpu), &nmsg->base.lmsg); 788 } 789 } 790 791 #endif 792 793 /* 794 * Close a TCP control block: 795 * discard all space held by the tcp 796 * discard internet protocol block 797 * wake up any sleepers 798 */ 799 struct tcpcb * 800 tcp_close(struct tcpcb *tp) 801 { 802 struct tseg_qent *q; 803 struct inpcb *inp = tp->t_inpcb; 804 struct socket *so = inp->inp_socket; 805 struct rtentry *rt; 806 boolean_t dosavessthresh; 807 #ifdef SMP 808 int cpu; 809 #endif 810 #ifdef INET6 811 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 812 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 813 #else 814 const boolean_t isipv6 = FALSE; 815 #endif 816 817 /* 818 * The tp is not instantly destroyed in the wildcard case. Setting 819 * the state to TCPS_TERMINATING will prevent the TCP stack from 820 * messing with it, though it should be noted that this change may 821 * not take effect on other cpus until we have chained the wildcard 822 * hash removal. 823 * 824 * XXX we currently depend on the BGL to synchronize the tp->t_state 825 * update and prevent other tcp protocol threads from accepting new 826 * connections on the listen socket we might be trying to close down. 827 */ 828 KKASSERT(tp->t_state != TCPS_TERMINATING); 829 tp->t_state = TCPS_TERMINATING; 830 831 /* 832 * Make sure that all of our timers are stopped before we 833 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 834 * timers are never used. If timer message is never created 835 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 836 */ 837 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 838 tcp_callout_stop(tp, tp->tt_rexmt); 839 tcp_callout_stop(tp, tp->tt_persist); 840 tcp_callout_stop(tp, tp->tt_keep); 841 tcp_callout_stop(tp, tp->tt_2msl); 842 tcp_callout_stop(tp, tp->tt_delack); 843 } 844 845 if (tp->t_flags & TF_ONOUTPUTQ) { 846 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 847 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 848 tp->t_flags &= ~TF_ONOUTPUTQ; 849 } 850 851 /* 852 * If we got enough samples through the srtt filter, 853 * save the rtt and rttvar in the routing entry. 854 * 'Enough' is arbitrarily defined as the 16 samples. 855 * 16 samples is enough for the srtt filter to converge 856 * to within 5% of the correct value; fewer samples and 857 * we could save a very bogus rtt. 858 * 859 * Don't update the default route's characteristics and don't 860 * update anything that the user "locked". 861 */ 862 if (tp->t_rttupdated >= 16) { 863 u_long i = 0; 864 865 if (isipv6) { 866 struct sockaddr_in6 *sin6; 867 868 if ((rt = inp->in6p_route.ro_rt) == NULL) 869 goto no_valid_rt; 870 sin6 = (struct sockaddr_in6 *)rt_key(rt); 871 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 872 goto no_valid_rt; 873 } else 874 if ((rt = inp->inp_route.ro_rt) == NULL || 875 ((struct sockaddr_in *)rt_key(rt))-> 876 sin_addr.s_addr == INADDR_ANY) 877 goto no_valid_rt; 878 879 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 880 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 881 if (rt->rt_rmx.rmx_rtt && i) 882 /* 883 * filter this update to half the old & half 884 * the new values, converting scale. 885 * See route.h and tcp_var.h for a 886 * description of the scaling constants. 887 */ 888 rt->rt_rmx.rmx_rtt = 889 (rt->rt_rmx.rmx_rtt + i) / 2; 890 else 891 rt->rt_rmx.rmx_rtt = i; 892 tcpstat.tcps_cachedrtt++; 893 } 894 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 895 i = tp->t_rttvar * 896 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 897 if (rt->rt_rmx.rmx_rttvar && i) 898 rt->rt_rmx.rmx_rttvar = 899 (rt->rt_rmx.rmx_rttvar + i) / 2; 900 else 901 rt->rt_rmx.rmx_rttvar = i; 902 tcpstat.tcps_cachedrttvar++; 903 } 904 /* 905 * The old comment here said: 906 * update the pipelimit (ssthresh) if it has been updated 907 * already or if a pipesize was specified & the threshhold 908 * got below half the pipesize. I.e., wait for bad news 909 * before we start updating, then update on both good 910 * and bad news. 911 * 912 * But we want to save the ssthresh even if no pipesize is 913 * specified explicitly in the route, because such 914 * connections still have an implicit pipesize specified 915 * by the global tcp_sendspace. In the absence of a reliable 916 * way to calculate the pipesize, it will have to do. 917 */ 918 i = tp->snd_ssthresh; 919 if (rt->rt_rmx.rmx_sendpipe != 0) 920 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 921 else 922 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 923 if (dosavessthresh || 924 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 925 (rt->rt_rmx.rmx_ssthresh != 0))) { 926 /* 927 * convert the limit from user data bytes to 928 * packets then to packet data bytes. 929 */ 930 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 931 if (i < 2) 932 i = 2; 933 i *= tp->t_maxseg + 934 (isipv6 ? 935 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 936 sizeof(struct tcpiphdr)); 937 if (rt->rt_rmx.rmx_ssthresh) 938 rt->rt_rmx.rmx_ssthresh = 939 (rt->rt_rmx.rmx_ssthresh + i) / 2; 940 else 941 rt->rt_rmx.rmx_ssthresh = i; 942 tcpstat.tcps_cachedssthresh++; 943 } 944 } 945 946 no_valid_rt: 947 /* free the reassembly queue, if any */ 948 while((q = LIST_FIRST(&tp->t_segq)) != NULL) { 949 LIST_REMOVE(q, tqe_q); 950 m_freem(q->tqe_m); 951 FREE(q, M_TSEGQ); 952 atomic_add_int(&tcp_reass_qsize, -1); 953 } 954 /* throw away SACK blocks in scoreboard*/ 955 if (TCP_DO_SACK(tp)) 956 tcp_sack_cleanup(&tp->scb); 957 958 inp->inp_ppcb = NULL; 959 soisdisconnected(so); 960 /* note: pcb detached later on */ 961 962 tcp_destroy_timermsg(tp); 963 if (tp->t_flags & TF_SYNCACHE) 964 syncache_destroy(tp); 965 966 /* 967 * Discard the inp. In the SMP case a wildcard inp's hash (created 968 * by a listen socket or an INADDR_ANY udp socket) is replicated 969 * for each protocol thread and must be removed in the context of 970 * that thread. This is accomplished by chaining the message 971 * through the cpus. 972 * 973 * If the inp is not wildcarded we simply detach, which will remove 974 * the any hashes still present for this inp. 975 */ 976 #ifdef SMP 977 if (inp->inp_flags & INP_WILDCARD_MP) { 978 struct netmsg_remwildcard *nmsg; 979 980 cpu = (inp->inp_pcbinfo->cpu + 1) % ncpus2; 981 nmsg = kmalloc(sizeof(struct netmsg_remwildcard), 982 M_LWKTMSG, M_INTWAIT); 983 netmsg_init(&nmsg->base, NULL, &netisr_afree_rport, 984 0, in_pcbremwildcardhash_handler); 985 #ifdef INET6 986 nmsg->nm_isinet6 = isafinet6; 987 #endif 988 nmsg->nm_inp = inp; 989 nmsg->nm_pcbinfo = &tcbinfo[cpu]; 990 lwkt_sendmsg(cpu_portfn(cpu), &nmsg->base.lmsg); 991 } else 992 #endif 993 { 994 /* note: detach removes any wildcard hash entry */ 995 #ifdef INET6 996 if (isafinet6) 997 in6_pcbdetach(inp); 998 else 999 #endif 1000 in_pcbdetach(inp); 1001 } 1002 tcpstat.tcps_closed++; 1003 return (NULL); 1004 } 1005 1006 static __inline void 1007 tcp_drain_oncpu(struct inpcbhead *head) 1008 { 1009 struct inpcb *marker; 1010 struct inpcb *inpb; 1011 struct tcpcb *tcpb; 1012 struct tseg_qent *te; 1013 1014 /* 1015 * Allows us to block while running the list 1016 */ 1017 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1018 marker->inp_flags |= INP_PLACEMARKER; 1019 LIST_INSERT_HEAD(head, marker, inp_list); 1020 1021 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) { 1022 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 && 1023 (tcpb = intotcpcb(inpb)) != NULL && 1024 (te = LIST_FIRST(&tcpb->t_segq)) != NULL) { 1025 LIST_REMOVE(te, tqe_q); 1026 m_freem(te->tqe_m); 1027 FREE(te, M_TSEGQ); 1028 atomic_add_int(&tcp_reass_qsize, -1); 1029 /* retry */ 1030 } else { 1031 LIST_REMOVE(marker, inp_list); 1032 LIST_INSERT_AFTER(inpb, marker, inp_list); 1033 } 1034 } 1035 LIST_REMOVE(marker, inp_list); 1036 kfree(marker, M_TEMP); 1037 } 1038 1039 #ifdef SMP 1040 struct netmsg_tcp_drain { 1041 struct netmsg_base base; 1042 struct inpcbhead *nm_head; 1043 }; 1044 1045 static void 1046 tcp_drain_handler(netmsg_t msg) 1047 { 1048 struct netmsg_tcp_drain *nm = (void *)msg; 1049 1050 tcp_drain_oncpu(nm->nm_head); 1051 lwkt_replymsg(&nm->base.lmsg, 0); 1052 } 1053 #endif 1054 1055 void 1056 tcp_drain(void) 1057 { 1058 #ifdef SMP 1059 int cpu; 1060 #endif 1061 1062 if (!do_tcpdrain) 1063 return; 1064 1065 /* 1066 * Walk the tcpbs, if existing, and flush the reassembly queue, 1067 * if there is one... 1068 * XXX: The "Net/3" implementation doesn't imply that the TCP 1069 * reassembly queue should be flushed, but in a situation 1070 * where we're really low on mbufs, this is potentially 1071 * useful. 1072 */ 1073 #ifdef SMP 1074 for (cpu = 0; cpu < ncpus2; cpu++) { 1075 struct netmsg_tcp_drain *nm; 1076 1077 if (cpu == mycpu->gd_cpuid) { 1078 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1079 } else { 1080 nm = kmalloc(sizeof(struct netmsg_tcp_drain), 1081 M_LWKTMSG, M_NOWAIT); 1082 if (nm == NULL) 1083 continue; 1084 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1085 0, tcp_drain_handler); 1086 nm->nm_head = &tcbinfo[cpu].pcblisthead; 1087 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg); 1088 } 1089 } 1090 #else 1091 tcp_drain_oncpu(&tcbinfo[0].pcblisthead); 1092 #endif 1093 } 1094 1095 /* 1096 * Notify a tcp user of an asynchronous error; 1097 * store error as soft error, but wake up user 1098 * (for now, won't do anything until can select for soft error). 1099 * 1100 * Do not wake up user since there currently is no mechanism for 1101 * reporting soft errors (yet - a kqueue filter may be added). 1102 */ 1103 static void 1104 tcp_notify(struct inpcb *inp, int error) 1105 { 1106 struct tcpcb *tp = intotcpcb(inp); 1107 1108 /* 1109 * Ignore some errors if we are hooked up. 1110 * If connection hasn't completed, has retransmitted several times, 1111 * and receives a second error, give up now. This is better 1112 * than waiting a long time to establish a connection that 1113 * can never complete. 1114 */ 1115 if (tp->t_state == TCPS_ESTABLISHED && 1116 (error == EHOSTUNREACH || error == ENETUNREACH || 1117 error == EHOSTDOWN)) { 1118 return; 1119 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1120 tp->t_softerror) 1121 tcp_drop(tp, error); 1122 else 1123 tp->t_softerror = error; 1124 #if 0 1125 wakeup(&so->so_timeo); 1126 sorwakeup(so); 1127 sowwakeup(so); 1128 #endif 1129 } 1130 1131 static int 1132 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1133 { 1134 int error, i, n; 1135 struct inpcb *marker; 1136 struct inpcb *inp; 1137 inp_gen_t gencnt; 1138 globaldata_t gd; 1139 int origcpu, ccpu; 1140 1141 error = 0; 1142 n = 0; 1143 1144 /* 1145 * The process of preparing the TCB list is too time-consuming and 1146 * resource-intensive to repeat twice on every request. 1147 */ 1148 if (req->oldptr == NULL) { 1149 for (ccpu = 0; ccpu < ncpus; ++ccpu) { 1150 gd = globaldata_find(ccpu); 1151 n += tcbinfo[gd->gd_cpuid].ipi_count; 1152 } 1153 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1154 return (0); 1155 } 1156 1157 if (req->newptr != NULL) 1158 return (EPERM); 1159 1160 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1161 marker->inp_flags |= INP_PLACEMARKER; 1162 1163 /* 1164 * OK, now we're committed to doing something. Run the inpcb list 1165 * for each cpu in the system and construct the output. Use a 1166 * list placemarker to deal with list changes occuring during 1167 * copyout blockages (but otherwise depend on being on the correct 1168 * cpu to avoid races). 1169 */ 1170 origcpu = mycpu->gd_cpuid; 1171 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) { 1172 globaldata_t rgd; 1173 caddr_t inp_ppcb; 1174 struct xtcpcb xt; 1175 int cpu_id; 1176 1177 cpu_id = (origcpu + ccpu) % ncpus; 1178 if ((smp_active_mask & (1 << cpu_id)) == 0) 1179 continue; 1180 rgd = globaldata_find(cpu_id); 1181 lwkt_setcpu_self(rgd); 1182 1183 gencnt = tcbinfo[cpu_id].ipi_gencnt; 1184 n = tcbinfo[cpu_id].ipi_count; 1185 1186 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list); 1187 i = 0; 1188 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1189 /* 1190 * process a snapshot of pcbs, ignoring placemarkers 1191 * and using our own to allow SYSCTL_OUT to block. 1192 */ 1193 LIST_REMOVE(marker, inp_list); 1194 LIST_INSERT_AFTER(inp, marker, inp_list); 1195 1196 if (inp->inp_flags & INP_PLACEMARKER) 1197 continue; 1198 if (inp->inp_gencnt > gencnt) 1199 continue; 1200 if (prison_xinpcb(req->td, inp)) 1201 continue; 1202 1203 xt.xt_len = sizeof xt; 1204 bcopy(inp, &xt.xt_inp, sizeof *inp); 1205 inp_ppcb = inp->inp_ppcb; 1206 if (inp_ppcb != NULL) 1207 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1208 else 1209 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1210 if (inp->inp_socket) 1211 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1212 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1213 break; 1214 ++i; 1215 } 1216 LIST_REMOVE(marker, inp_list); 1217 if (error == 0 && i < n) { 1218 bzero(&xt, sizeof xt); 1219 xt.xt_len = sizeof xt; 1220 while (i < n) { 1221 error = SYSCTL_OUT(req, &xt, sizeof xt); 1222 if (error) 1223 break; 1224 ++i; 1225 } 1226 } 1227 } 1228 1229 /* 1230 * Make sure we are on the same cpu we were on originally, since 1231 * higher level callers expect this. Also don't pollute caches with 1232 * migrated userland data by (eventually) returning to userland 1233 * on a different cpu. 1234 */ 1235 lwkt_setcpu_self(globaldata_find(origcpu)); 1236 kfree(marker, M_TEMP); 1237 return (error); 1238 } 1239 1240 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1241 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1242 1243 static int 1244 tcp_getcred(SYSCTL_HANDLER_ARGS) 1245 { 1246 struct sockaddr_in addrs[2]; 1247 struct inpcb *inp; 1248 int cpu; 1249 int error; 1250 1251 error = priv_check(req->td, PRIV_ROOT); 1252 if (error != 0) 1253 return (error); 1254 error = SYSCTL_IN(req, addrs, sizeof addrs); 1255 if (error != 0) 1256 return (error); 1257 crit_enter(); 1258 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1259 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1260 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1261 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1262 if (inp == NULL || inp->inp_socket == NULL) { 1263 error = ENOENT; 1264 goto out; 1265 } 1266 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1267 out: 1268 crit_exit(); 1269 return (error); 1270 } 1271 1272 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1273 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1274 1275 #ifdef INET6 1276 static int 1277 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1278 { 1279 struct sockaddr_in6 addrs[2]; 1280 struct inpcb *inp; 1281 int error; 1282 boolean_t mapped = FALSE; 1283 1284 error = priv_check(req->td, PRIV_ROOT); 1285 if (error != 0) 1286 return (error); 1287 error = SYSCTL_IN(req, addrs, sizeof addrs); 1288 if (error != 0) 1289 return (error); 1290 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1291 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1292 mapped = TRUE; 1293 else 1294 return (EINVAL); 1295 } 1296 crit_enter(); 1297 if (mapped) { 1298 inp = in_pcblookup_hash(&tcbinfo[0], 1299 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1300 addrs[1].sin6_port, 1301 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1302 addrs[0].sin6_port, 1303 0, NULL); 1304 } else { 1305 inp = in6_pcblookup_hash(&tcbinfo[0], 1306 &addrs[1].sin6_addr, addrs[1].sin6_port, 1307 &addrs[0].sin6_addr, addrs[0].sin6_port, 1308 0, NULL); 1309 } 1310 if (inp == NULL || inp->inp_socket == NULL) { 1311 error = ENOENT; 1312 goto out; 1313 } 1314 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1315 out: 1316 crit_exit(); 1317 return (error); 1318 } 1319 1320 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1321 0, 0, 1322 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1323 #endif 1324 1325 struct netmsg_tcp_notify { 1326 struct netmsg_base base; 1327 void (*nm_notify)(struct inpcb *, int); 1328 struct in_addr nm_faddr; 1329 int nm_arg; 1330 }; 1331 1332 static void 1333 tcp_notifyall_oncpu(netmsg_t msg) 1334 { 1335 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1336 int nextcpu; 1337 1338 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr, 1339 nm->nm_arg, nm->nm_notify); 1340 1341 nextcpu = mycpuid + 1; 1342 if (nextcpu < ncpus2) 1343 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg); 1344 else 1345 lwkt_replymsg(&nm->base.lmsg, 0); 1346 } 1347 1348 void 1349 tcp_ctlinput(netmsg_t msg) 1350 { 1351 int cmd = msg->ctlinput.nm_cmd; 1352 struct sockaddr *sa = msg->ctlinput.nm_arg; 1353 struct ip *ip = msg->ctlinput.nm_extra; 1354 struct tcphdr *th; 1355 struct in_addr faddr; 1356 struct inpcb *inp; 1357 struct tcpcb *tp; 1358 void (*notify)(struct inpcb *, int) = tcp_notify; 1359 tcp_seq icmpseq; 1360 int arg, cpu; 1361 1362 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1363 goto done; 1364 } 1365 1366 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1367 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1368 goto done; 1369 1370 arg = inetctlerrmap[cmd]; 1371 if (cmd == PRC_QUENCH) { 1372 notify = tcp_quench; 1373 } else if (icmp_may_rst && 1374 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1375 cmd == PRC_UNREACH_PORT || 1376 cmd == PRC_TIMXCEED_INTRANS) && 1377 ip != NULL) { 1378 notify = tcp_drop_syn_sent; 1379 } else if (cmd == PRC_MSGSIZE) { 1380 struct icmp *icmp = (struct icmp *) 1381 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1382 1383 arg = ntohs(icmp->icmp_nextmtu); 1384 notify = tcp_mtudisc; 1385 } else if (PRC_IS_REDIRECT(cmd)) { 1386 ip = NULL; 1387 notify = in_rtchange; 1388 } else if (cmd == PRC_HOSTDEAD) { 1389 ip = NULL; 1390 } 1391 1392 if (ip != NULL) { 1393 crit_enter(); 1394 th = (struct tcphdr *)((caddr_t)ip + 1395 (IP_VHL_HL(ip->ip_vhl) << 2)); 1396 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1397 ip->ip_src.s_addr, th->th_sport); 1398 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1399 ip->ip_src, th->th_sport, 0, NULL); 1400 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1401 icmpseq = htonl(th->th_seq); 1402 tp = intotcpcb(inp); 1403 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1404 SEQ_LT(icmpseq, tp->snd_max)) 1405 (*notify)(inp, arg); 1406 } else { 1407 struct in_conninfo inc; 1408 1409 inc.inc_fport = th->th_dport; 1410 inc.inc_lport = th->th_sport; 1411 inc.inc_faddr = faddr; 1412 inc.inc_laddr = ip->ip_src; 1413 #ifdef INET6 1414 inc.inc_isipv6 = 0; 1415 #endif 1416 syncache_unreach(&inc, th); 1417 } 1418 crit_exit(); 1419 } else { 1420 struct netmsg_tcp_notify *nm; 1421 1422 KKASSERT(&curthread->td_msgport == cpu_portfn(0)); 1423 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1424 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1425 0, tcp_notifyall_oncpu); 1426 nm->nm_faddr = faddr; 1427 nm->nm_arg = arg; 1428 nm->nm_notify = notify; 1429 1430 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg); 1431 } 1432 done: 1433 lwkt_replymsg(&msg->lmsg, 0); 1434 } 1435 1436 #ifdef INET6 1437 1438 void 1439 tcp6_ctlinput(netmsg_t msg) 1440 { 1441 int cmd = msg->ctlinput.nm_cmd; 1442 struct sockaddr *sa = msg->ctlinput.nm_arg; 1443 void *d = msg->ctlinput.nm_extra; 1444 struct tcphdr th; 1445 void (*notify) (struct inpcb *, int) = tcp_notify; 1446 struct ip6_hdr *ip6; 1447 struct mbuf *m; 1448 struct ip6ctlparam *ip6cp = NULL; 1449 const struct sockaddr_in6 *sa6_src = NULL; 1450 int off; 1451 struct tcp_portonly { 1452 u_int16_t th_sport; 1453 u_int16_t th_dport; 1454 } *thp; 1455 int arg; 1456 1457 if (sa->sa_family != AF_INET6 || 1458 sa->sa_len != sizeof(struct sockaddr_in6)) { 1459 goto out; 1460 } 1461 1462 arg = 0; 1463 if (cmd == PRC_QUENCH) 1464 notify = tcp_quench; 1465 else if (cmd == PRC_MSGSIZE) { 1466 struct ip6ctlparam *ip6cp = d; 1467 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1468 1469 arg = ntohl(icmp6->icmp6_mtu); 1470 notify = tcp_mtudisc; 1471 } else if (!PRC_IS_REDIRECT(cmd) && 1472 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1473 goto out; 1474 } 1475 1476 /* if the parameter is from icmp6, decode it. */ 1477 if (d != NULL) { 1478 ip6cp = (struct ip6ctlparam *)d; 1479 m = ip6cp->ip6c_m; 1480 ip6 = ip6cp->ip6c_ip6; 1481 off = ip6cp->ip6c_off; 1482 sa6_src = ip6cp->ip6c_src; 1483 } else { 1484 m = NULL; 1485 ip6 = NULL; 1486 off = 0; /* fool gcc */ 1487 sa6_src = &sa6_any; 1488 } 1489 1490 if (ip6 != NULL) { 1491 struct in_conninfo inc; 1492 /* 1493 * XXX: We assume that when IPV6 is non NULL, 1494 * M and OFF are valid. 1495 */ 1496 1497 /* check if we can safely examine src and dst ports */ 1498 if (m->m_pkthdr.len < off + sizeof *thp) 1499 goto out; 1500 1501 bzero(&th, sizeof th); 1502 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1503 1504 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1505 (struct sockaddr *)ip6cp->ip6c_src, 1506 th.th_sport, cmd, arg, notify); 1507 1508 inc.inc_fport = th.th_dport; 1509 inc.inc_lport = th.th_sport; 1510 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1511 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1512 inc.inc_isipv6 = 1; 1513 syncache_unreach(&inc, &th); 1514 } else { 1515 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1516 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1517 } 1518 out: 1519 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1520 } 1521 1522 #endif 1523 1524 /* 1525 * Following is where TCP initial sequence number generation occurs. 1526 * 1527 * There are two places where we must use initial sequence numbers: 1528 * 1. In SYN-ACK packets. 1529 * 2. In SYN packets. 1530 * 1531 * All ISNs for SYN-ACK packets are generated by the syncache. See 1532 * tcp_syncache.c for details. 1533 * 1534 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1535 * depends on this property. In addition, these ISNs should be 1536 * unguessable so as to prevent connection hijacking. To satisfy 1537 * the requirements of this situation, the algorithm outlined in 1538 * RFC 1948 is used to generate sequence numbers. 1539 * 1540 * Implementation details: 1541 * 1542 * Time is based off the system timer, and is corrected so that it 1543 * increases by one megabyte per second. This allows for proper 1544 * recycling on high speed LANs while still leaving over an hour 1545 * before rollover. 1546 * 1547 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1548 * between seeding of isn_secret. This is normally set to zero, 1549 * as reseeding should not be necessary. 1550 * 1551 */ 1552 1553 #define ISN_BYTES_PER_SECOND 1048576 1554 1555 u_char isn_secret[32]; 1556 int isn_last_reseed; 1557 MD5_CTX isn_ctx; 1558 1559 tcp_seq 1560 tcp_new_isn(struct tcpcb *tp) 1561 { 1562 u_int32_t md5_buffer[4]; 1563 tcp_seq new_isn; 1564 1565 /* Seed if this is the first use, reseed if requested. */ 1566 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1567 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1568 < (u_int)ticks))) { 1569 read_random_unlimited(&isn_secret, sizeof isn_secret); 1570 isn_last_reseed = ticks; 1571 } 1572 1573 /* Compute the md5 hash and return the ISN. */ 1574 MD5Init(&isn_ctx); 1575 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1576 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1577 #ifdef INET6 1578 if (tp->t_inpcb->inp_vflag & INP_IPV6) { 1579 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1580 sizeof(struct in6_addr)); 1581 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1582 sizeof(struct in6_addr)); 1583 } else 1584 #endif 1585 { 1586 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1587 sizeof(struct in_addr)); 1588 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1589 sizeof(struct in_addr)); 1590 } 1591 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1592 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1593 new_isn = (tcp_seq) md5_buffer[0]; 1594 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1595 return (new_isn); 1596 } 1597 1598 /* 1599 * When a source quench is received, close congestion window 1600 * to one segment. We will gradually open it again as we proceed. 1601 */ 1602 void 1603 tcp_quench(struct inpcb *inp, int error) 1604 { 1605 struct tcpcb *tp = intotcpcb(inp); 1606 1607 if (tp != NULL) { 1608 tp->snd_cwnd = tp->t_maxseg; 1609 tp->snd_wacked = 0; 1610 } 1611 } 1612 1613 /* 1614 * When a specific ICMP unreachable message is received and the 1615 * connection state is SYN-SENT, drop the connection. This behavior 1616 * is controlled by the icmp_may_rst sysctl. 1617 */ 1618 void 1619 tcp_drop_syn_sent(struct inpcb *inp, int error) 1620 { 1621 struct tcpcb *tp = intotcpcb(inp); 1622 1623 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT)) 1624 tcp_drop(tp, error); 1625 } 1626 1627 /* 1628 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1629 * based on the new value in the route. Also nudge TCP to send something, 1630 * since we know the packet we just sent was dropped. 1631 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1632 */ 1633 void 1634 tcp_mtudisc(struct inpcb *inp, int mtu) 1635 { 1636 struct tcpcb *tp = intotcpcb(inp); 1637 struct rtentry *rt; 1638 struct socket *so = inp->inp_socket; 1639 int maxopd, mss; 1640 #ifdef INET6 1641 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0); 1642 #else 1643 const boolean_t isipv6 = FALSE; 1644 #endif 1645 1646 if (tp == NULL) 1647 return; 1648 1649 /* 1650 * If no MTU is provided in the ICMP message, use the 1651 * next lower likely value, as specified in RFC 1191. 1652 */ 1653 if (mtu == 0) { 1654 int oldmtu; 1655 1656 oldmtu = tp->t_maxopd + 1657 (isipv6 ? 1658 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1659 sizeof(struct tcpiphdr)); 1660 mtu = ip_next_mtu(oldmtu, 0); 1661 } 1662 1663 if (isipv6) 1664 rt = tcp_rtlookup6(&inp->inp_inc); 1665 else 1666 rt = tcp_rtlookup(&inp->inp_inc); 1667 if (rt != NULL) { 1668 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1669 mtu = rt->rt_rmx.rmx_mtu; 1670 1671 maxopd = mtu - 1672 (isipv6 ? 1673 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1674 sizeof(struct tcpiphdr)); 1675 1676 /* 1677 * XXX - The following conditional probably violates the TCP 1678 * spec. The problem is that, since we don't know the 1679 * other end's MSS, we are supposed to use a conservative 1680 * default. But, if we do that, then MTU discovery will 1681 * never actually take place, because the conservative 1682 * default is much less than the MTUs typically seen 1683 * on the Internet today. For the moment, we'll sweep 1684 * this under the carpet. 1685 * 1686 * The conservative default might not actually be a problem 1687 * if the only case this occurs is when sending an initial 1688 * SYN with options and data to a host we've never talked 1689 * to before. Then, they will reply with an MSS value which 1690 * will get recorded and the new parameters should get 1691 * recomputed. For Further Study. 1692 */ 1693 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1694 maxopd = rt->rt_rmx.rmx_mssopt; 1695 } else 1696 maxopd = mtu - 1697 (isipv6 ? 1698 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1699 sizeof(struct tcpiphdr)); 1700 1701 if (tp->t_maxopd <= maxopd) 1702 return; 1703 tp->t_maxopd = maxopd; 1704 1705 mss = maxopd; 1706 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1707 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1708 mss -= TCPOLEN_TSTAMP_APPA; 1709 1710 /* round down to multiple of MCLBYTES */ 1711 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1712 if (mss > MCLBYTES) 1713 mss &= ~(MCLBYTES - 1); 1714 #else 1715 if (mss > MCLBYTES) 1716 mss = (mss / MCLBYTES) * MCLBYTES; 1717 #endif 1718 1719 if (so->so_snd.ssb_hiwat < mss) 1720 mss = so->so_snd.ssb_hiwat; 1721 1722 tp->t_maxseg = mss; 1723 tp->t_rtttime = 0; 1724 tp->snd_nxt = tp->snd_una; 1725 tcp_output(tp); 1726 tcpstat.tcps_mturesent++; 1727 } 1728 1729 /* 1730 * Look-up the routing entry to the peer of this inpcb. If no route 1731 * is found and it cannot be allocated the return NULL. This routine 1732 * is called by TCP routines that access the rmx structure and by tcp_mss 1733 * to get the interface MTU. 1734 */ 1735 struct rtentry * 1736 tcp_rtlookup(struct in_conninfo *inc) 1737 { 1738 struct route *ro = &inc->inc_route; 1739 1740 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1741 /* No route yet, so try to acquire one */ 1742 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1743 /* 1744 * unused portions of the structure MUST be zero'd 1745 * out because rtalloc() treats it as opaque data 1746 */ 1747 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1748 ro->ro_dst.sa_family = AF_INET; 1749 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1750 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1751 inc->inc_faddr; 1752 rtalloc(ro); 1753 } 1754 } 1755 return (ro->ro_rt); 1756 } 1757 1758 #ifdef INET6 1759 struct rtentry * 1760 tcp_rtlookup6(struct in_conninfo *inc) 1761 { 1762 struct route_in6 *ro6 = &inc->inc6_route; 1763 1764 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1765 /* No route yet, so try to acquire one */ 1766 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1767 /* 1768 * unused portions of the structure MUST be zero'd 1769 * out because rtalloc() treats it as opaque data 1770 */ 1771 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1772 ro6->ro_dst.sin6_family = AF_INET6; 1773 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1774 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1775 rtalloc((struct route *)ro6); 1776 } 1777 } 1778 return (ro6->ro_rt); 1779 } 1780 #endif 1781 1782 #ifdef IPSEC 1783 /* compute ESP/AH header size for TCP, including outer IP header. */ 1784 size_t 1785 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1786 { 1787 struct inpcb *inp; 1788 struct mbuf *m; 1789 size_t hdrsiz; 1790 struct ip *ip; 1791 struct tcphdr *th; 1792 1793 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1794 return (0); 1795 MGETHDR(m, MB_DONTWAIT, MT_DATA); 1796 if (!m) 1797 return (0); 1798 1799 #ifdef INET6 1800 if (inp->inp_vflag & INP_IPV6) { 1801 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1802 1803 th = (struct tcphdr *)(ip6 + 1); 1804 m->m_pkthdr.len = m->m_len = 1805 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1806 tcp_fillheaders(tp, ip6, th); 1807 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1808 } else 1809 #endif 1810 { 1811 ip = mtod(m, struct ip *); 1812 th = (struct tcphdr *)(ip + 1); 1813 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1814 tcp_fillheaders(tp, ip, th); 1815 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1816 } 1817 1818 m_free(m); 1819 return (hdrsiz); 1820 } 1821 #endif 1822 1823 /* 1824 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1825 * 1826 * This code attempts to calculate the bandwidth-delay product as a 1827 * means of determining the optimal window size to maximize bandwidth, 1828 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1829 * routers. This code also does a fairly good job keeping RTTs in check 1830 * across slow links like modems. We implement an algorithm which is very 1831 * similar (but not meant to be) TCP/Vegas. The code operates on the 1832 * transmitter side of a TCP connection and so only effects the transmit 1833 * side of the connection. 1834 * 1835 * BACKGROUND: TCP makes no provision for the management of buffer space 1836 * at the end points or at the intermediate routers and switches. A TCP 1837 * stream, whether using NewReno or not, will eventually buffer as 1838 * many packets as it is able and the only reason this typically works is 1839 * due to the fairly small default buffers made available for a connection 1840 * (typicaly 16K or 32K). As machines use larger windows and/or window 1841 * scaling it is now fairly easy for even a single TCP connection to blow-out 1842 * all available buffer space not only on the local interface, but on 1843 * intermediate routers and switches as well. NewReno makes a misguided 1844 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1845 * then backing off, then steadily increasing the window again until another 1846 * failure occurs, ad-infinitum. This results in terrible oscillation that 1847 * is only made worse as network loads increase and the idea of intentionally 1848 * blowing out network buffers is, frankly, a terrible way to manage network 1849 * resources. 1850 * 1851 * It is far better to limit the transmit window prior to the failure 1852 * condition being achieved. There are two general ways to do this: First 1853 * you can 'scan' through different transmit window sizes and locate the 1854 * point where the RTT stops increasing, indicating that you have filled the 1855 * pipe, then scan backwards until you note that RTT stops decreasing, then 1856 * repeat ad-infinitum. This method works in principle but has severe 1857 * implementation issues due to RTT variances, timer granularity, and 1858 * instability in the algorithm which can lead to many false positives and 1859 * create oscillations as well as interact badly with other TCP streams 1860 * implementing the same algorithm. 1861 * 1862 * The second method is to limit the window to the bandwidth delay product 1863 * of the link. This is the method we implement. RTT variances and our 1864 * own manipulation of the congestion window, bwnd, can potentially 1865 * destabilize the algorithm. For this reason we have to stabilize the 1866 * elements used to calculate the window. We do this by using the minimum 1867 * observed RTT, the long term average of the observed bandwidth, and 1868 * by adding two segments worth of slop. It isn't perfect but it is able 1869 * to react to changing conditions and gives us a very stable basis on 1870 * which to extend the algorithm. 1871 */ 1872 void 1873 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1874 { 1875 u_long bw; 1876 u_long bwnd; 1877 int save_ticks; 1878 int delta_ticks; 1879 1880 /* 1881 * If inflight_enable is disabled in the middle of a tcp connection, 1882 * make sure snd_bwnd is effectively disabled. 1883 */ 1884 if (!tcp_inflight_enable) { 1885 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1886 tp->snd_bandwidth = 0; 1887 return; 1888 } 1889 1890 /* 1891 * Validate the delta time. If a connection is new or has been idle 1892 * a long time we have to reset the bandwidth calculator. 1893 */ 1894 save_ticks = ticks; 1895 delta_ticks = save_ticks - tp->t_bw_rtttime; 1896 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1897 tp->t_bw_rtttime = ticks; 1898 tp->t_bw_rtseq = ack_seq; 1899 if (tp->snd_bandwidth == 0) 1900 tp->snd_bandwidth = tcp_inflight_min; 1901 return; 1902 } 1903 if (delta_ticks == 0) 1904 return; 1905 1906 /* 1907 * Sanity check, plus ignore pure window update acks. 1908 */ 1909 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1910 return; 1911 1912 /* 1913 * Figure out the bandwidth. Due to the tick granularity this 1914 * is a very rough number and it MUST be averaged over a fairly 1915 * long period of time. XXX we need to take into account a link 1916 * that is not using all available bandwidth, but for now our 1917 * slop will ramp us up if this case occurs and the bandwidth later 1918 * increases. 1919 */ 1920 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 1921 tp->t_bw_rtttime = save_ticks; 1922 tp->t_bw_rtseq = ack_seq; 1923 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1924 1925 tp->snd_bandwidth = bw; 1926 1927 /* 1928 * Calculate the semi-static bandwidth delay product, plus two maximal 1929 * segments. The additional slop puts us squarely in the sweet 1930 * spot and also handles the bandwidth run-up case. Without the 1931 * slop we could be locking ourselves into a lower bandwidth. 1932 * 1933 * Situations Handled: 1934 * (1) Prevents over-queueing of packets on LANs, especially on 1935 * high speed LANs, allowing larger TCP buffers to be 1936 * specified, and also does a good job preventing 1937 * over-queueing of packets over choke points like modems 1938 * (at least for the transmit side). 1939 * 1940 * (2) Is able to handle changing network loads (bandwidth 1941 * drops so bwnd drops, bandwidth increases so bwnd 1942 * increases). 1943 * 1944 * (3) Theoretically should stabilize in the face of multiple 1945 * connections implementing the same algorithm (this may need 1946 * a little work). 1947 * 1948 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1949 * be adjusted with a sysctl but typically only needs to be on 1950 * very slow connections. A value no smaller then 5 should 1951 * be used, but only reduce this default if you have no other 1952 * choice. 1953 */ 1954 1955 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1956 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 1957 tcp_inflight_stab * (int)tp->t_maxseg / 10; 1958 #undef USERTT 1959 1960 if (tcp_inflight_debug > 0) { 1961 static int ltime; 1962 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1963 ltime = ticks; 1964 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1965 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd); 1966 } 1967 } 1968 if ((long)bwnd < tcp_inflight_min) 1969 bwnd = tcp_inflight_min; 1970 if (bwnd > tcp_inflight_max) 1971 bwnd = tcp_inflight_max; 1972 if ((long)bwnd < tp->t_maxseg * 2) 1973 bwnd = tp->t_maxseg * 2; 1974 tp->snd_bwnd = bwnd; 1975 } 1976 1977 #ifdef TCP_SIGNATURE 1978 /* 1979 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1980 * 1981 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1982 * When called from tcp_input(), we can be sure that th_sum has been 1983 * zeroed out and verified already. 1984 * 1985 * Return 0 if successful, otherwise return -1. 1986 * 1987 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1988 * search with the destination IP address, and a 'magic SPI' to be 1989 * determined by the application. This is hardcoded elsewhere to 1179 1990 * right now. Another branch of this code exists which uses the SPD to 1991 * specify per-application flows but it is unstable. 1992 */ 1993 int 1994 tcpsignature_compute( 1995 struct mbuf *m, /* mbuf chain */ 1996 int len, /* length of TCP data */ 1997 int optlen, /* length of TCP options */ 1998 u_char *buf, /* storage for MD5 digest */ 1999 u_int direction) /* direction of flow */ 2000 { 2001 struct ippseudo ippseudo; 2002 MD5_CTX ctx; 2003 int doff; 2004 struct ip *ip; 2005 struct ipovly *ipovly; 2006 struct secasvar *sav; 2007 struct tcphdr *th; 2008 #ifdef INET6 2009 struct ip6_hdr *ip6; 2010 struct in6_addr in6; 2011 uint32_t plen; 2012 uint16_t nhdr; 2013 #endif /* INET6 */ 2014 u_short savecsum; 2015 2016 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 2017 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 2018 /* 2019 * Extract the destination from the IP header in the mbuf. 2020 */ 2021 ip = mtod(m, struct ip *); 2022 #ifdef INET6 2023 ip6 = NULL; /* Make the compiler happy. */ 2024 #endif /* INET6 */ 2025 /* 2026 * Look up an SADB entry which matches the address found in 2027 * the segment. 2028 */ 2029 switch (IP_VHL_V(ip->ip_vhl)) { 2030 case IPVERSION: 2031 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2032 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2033 break; 2034 #ifdef INET6 2035 case (IPV6_VERSION >> 4): 2036 ip6 = mtod(m, struct ip6_hdr *); 2037 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2038 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2039 break; 2040 #endif /* INET6 */ 2041 default: 2042 return (EINVAL); 2043 /* NOTREACHED */ 2044 break; 2045 } 2046 if (sav == NULL) { 2047 kprintf("%s: SADB lookup failed\n", __func__); 2048 return (EINVAL); 2049 } 2050 MD5Init(&ctx); 2051 2052 /* 2053 * Step 1: Update MD5 hash with IP pseudo-header. 2054 * 2055 * XXX The ippseudo header MUST be digested in network byte order, 2056 * or else we'll fail the regression test. Assume all fields we've 2057 * been doing arithmetic on have been in host byte order. 2058 * XXX One cannot depend on ipovly->ih_len here. When called from 2059 * tcp_output(), the underlying ip_len member has not yet been set. 2060 */ 2061 switch (IP_VHL_V(ip->ip_vhl)) { 2062 case IPVERSION: 2063 ipovly = (struct ipovly *)ip; 2064 ippseudo.ippseudo_src = ipovly->ih_src; 2065 ippseudo.ippseudo_dst = ipovly->ih_dst; 2066 ippseudo.ippseudo_pad = 0; 2067 ippseudo.ippseudo_p = IPPROTO_TCP; 2068 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2069 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2070 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2071 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2072 break; 2073 #ifdef INET6 2074 /* 2075 * RFC 2385, 2.0 Proposal 2076 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2077 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2078 * extended next header value (to form 32 bits), and 32-bit segment 2079 * length. 2080 * Note: Upper-Layer Packet Length comes before Next Header. 2081 */ 2082 case (IPV6_VERSION >> 4): 2083 in6 = ip6->ip6_src; 2084 in6_clearscope(&in6); 2085 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2086 in6 = ip6->ip6_dst; 2087 in6_clearscope(&in6); 2088 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2089 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2090 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2091 nhdr = 0; 2092 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2093 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2094 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2095 nhdr = IPPROTO_TCP; 2096 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2097 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2098 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2099 break; 2100 #endif /* INET6 */ 2101 default: 2102 return (EINVAL); 2103 /* NOTREACHED */ 2104 break; 2105 } 2106 /* 2107 * Step 2: Update MD5 hash with TCP header, excluding options. 2108 * The TCP checksum must be set to zero. 2109 */ 2110 savecsum = th->th_sum; 2111 th->th_sum = 0; 2112 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2113 th->th_sum = savecsum; 2114 /* 2115 * Step 3: Update MD5 hash with TCP segment data. 2116 * Use m_apply() to avoid an early m_pullup(). 2117 */ 2118 if (len > 0) 2119 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2120 /* 2121 * Step 4: Update MD5 hash with shared secret. 2122 */ 2123 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2124 MD5Final(buf, &ctx); 2125 key_sa_recordxfer(sav, m); 2126 key_freesav(sav); 2127 return (0); 2128 } 2129 2130 int 2131 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2132 { 2133 2134 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2135 return (0); 2136 } 2137 #endif /* TCP_SIGNATURE */ 2138