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