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