1 /* 2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Jeffrey M. Hsu. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of The DragonFly Project nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific, prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 67 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $ 68 * $DragonFly: src/sys/netinet/tcp_subr.c,v 1.63 2008/11/11 10:46:58 sephe Exp $ 69 */ 70 71 #include "opt_compat.h" 72 #include "opt_inet.h" 73 #include "opt_inet6.h" 74 #include "opt_ipsec.h" 75 #include "opt_tcpdebug.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/callout.h> 80 #include <sys/kernel.h> 81 #include <sys/sysctl.h> 82 #include <sys/malloc.h> 83 #include <sys/mpipe.h> 84 #include <sys/mbuf.h> 85 #ifdef INET6 86 #include <sys/domain.h> 87 #endif 88 #include <sys/proc.h> 89 #include <sys/priv.h> 90 #include <sys/socket.h> 91 #include <sys/socketvar.h> 92 #include <sys/protosw.h> 93 #include <sys/random.h> 94 #include <sys/in_cksum.h> 95 #include <sys/ktr.h> 96 97 #include <net/route.h> 98 #include <net/if.h> 99 #include <net/netisr.h> 100 101 #define _IP_VHL 102 #include <netinet/in.h> 103 #include <netinet/in_systm.h> 104 #include <netinet/ip.h> 105 #include <netinet/ip6.h> 106 #include <netinet/in_pcb.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet/in_var.h> 109 #include <netinet/ip_var.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet/ip_icmp.h> 112 #ifdef INET6 113 #include <netinet/icmp6.h> 114 #endif 115 #include <netinet/tcp.h> 116 #include <netinet/tcp_fsm.h> 117 #include <netinet/tcp_seq.h> 118 #include <netinet/tcp_timer.h> 119 #include <netinet/tcp_timer2.h> 120 #include <netinet/tcp_var.h> 121 #include <netinet6/tcp6_var.h> 122 #include <netinet/tcpip.h> 123 #ifdef TCPDEBUG 124 #include <netinet/tcp_debug.h> 125 #endif 126 #include <netinet6/ip6protosw.h> 127 128 #ifdef IPSEC 129 #include <netinet6/ipsec.h> 130 #include <netproto/key/key.h> 131 #ifdef INET6 132 #include <netinet6/ipsec6.h> 133 #endif 134 #endif 135 136 #ifdef FAST_IPSEC 137 #include <netproto/ipsec/ipsec.h> 138 #ifdef INET6 139 #include <netproto/ipsec/ipsec6.h> 140 #endif 141 #define IPSEC 142 #endif 143 144 #include <sys/md5.h> 145 #include <machine/smp.h> 146 147 #include <sys/msgport2.h> 148 #include <sys/mplock2.h> 149 #include <net/netmsg2.h> 150 151 #if !defined(KTR_TCP) 152 #define KTR_TCP KTR_ALL 153 #endif 154 KTR_INFO_MASTER(tcp); 155 /* 156 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 157 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 158 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 159 */ 160 #define logtcp(name) KTR_LOG(tcp_ ## name) 161 162 struct inpcbinfo tcbinfo[MAXCPU]; 163 struct tcpcbackqhead tcpcbackq[MAXCPU]; 164 165 int tcp_mssdflt = TCP_MSS; 166 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 167 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 168 169 #ifdef INET6 170 int tcp_v6mssdflt = TCP6_MSS; 171 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 172 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 173 #endif 174 175 /* 176 * Minimum MSS we accept and use. This prevents DoS attacks where 177 * we are forced to a ridiculous low MSS like 20 and send hundreds 178 * of packets instead of one. The effect scales with the available 179 * bandwidth and quickly saturates the CPU and network interface 180 * with packet generation and sending. Set to zero to disable MINMSS 181 * checking. This setting prevents us from sending too small packets. 182 */ 183 int tcp_minmss = TCP_MINMSS; 184 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 185 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 186 187 #if 0 188 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 189 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 190 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 191 #endif 192 193 int tcp_do_rfc1323 = 1; 194 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 195 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 196 197 static int tcp_tcbhashsize = 0; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 199 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 200 201 static int do_tcpdrain = 1; 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 203 "Enable tcp_drain routine for extra help when low on mbufs"); 204 205 static int icmp_may_rst = 1; 206 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 207 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 208 209 static int tcp_isn_reseed_interval = 0; 210 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 211 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 212 213 /* 214 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 215 * by default, but with generous values which should allow maximal 216 * bandwidth. In particular, the slop defaults to 50 (5 packets). 217 * 218 * The reason for doing this is that the limiter is the only mechanism we 219 * have which seems to do a really good job preventing receiver RX rings 220 * on network interfaces from getting blown out. Even though GigE/10GigE 221 * is supposed to flow control it looks like either it doesn't actually 222 * do it or Open Source drivers do not properly enable it. 223 * 224 * People using the limiter to reduce bottlenecks on slower WAN connections 225 * should set the slop to 20 (2 packets). 226 */ 227 static int tcp_inflight_enable = 1; 228 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 229 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 230 231 static int tcp_inflight_debug = 0; 232 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 233 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 234 235 static int tcp_inflight_min = 6144; 236 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 237 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 238 239 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 240 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 241 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 242 243 static int tcp_inflight_stab = 50; 244 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 245 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)"); 246 247 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 248 static struct malloc_pipe tcptemp_mpipe; 249 250 static void tcp_willblock(void); 251 static void tcp_notify (struct inpcb *, int); 252 253 struct tcp_stats tcpstats_percpu[MAXCPU]; 254 #ifdef SMP 255 static int 256 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 257 { 258 int cpu, error = 0; 259 260 for (cpu = 0; cpu < ncpus; ++cpu) { 261 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 262 sizeof(struct tcp_stats)))) 263 break; 264 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 265 sizeof(struct tcp_stats)))) 266 break; 267 } 268 269 return (error); 270 } 271 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 272 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 273 #else 274 SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW, 275 &tcpstat, tcp_stats, "TCP statistics"); 276 #endif 277 278 /* 279 * Target size of TCP PCB hash tables. Must be a power of two. 280 * 281 * Note that this can be overridden by the kernel environment 282 * variable net.inet.tcp.tcbhashsize 283 */ 284 #ifndef TCBHASHSIZE 285 #define TCBHASHSIZE 512 286 #endif 287 288 /* 289 * This is the actual shape of what we allocate using the zone 290 * allocator. Doing it this way allows us to protect both structures 291 * using the same generation count, and also eliminates the overhead 292 * of allocating tcpcbs separately. By hiding the structure here, 293 * we avoid changing most of the rest of the code (although it needs 294 * to be changed, eventually, for greater efficiency). 295 */ 296 #define ALIGNMENT 32 297 #define ALIGNM1 (ALIGNMENT - 1) 298 struct inp_tp { 299 union { 300 struct inpcb inp; 301 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 302 } inp_tp_u; 303 struct tcpcb tcb; 304 struct tcp_callout inp_tp_rexmt; 305 struct tcp_callout inp_tp_persist; 306 struct tcp_callout inp_tp_keep; 307 struct tcp_callout inp_tp_2msl; 308 struct tcp_callout inp_tp_delack; 309 struct netmsg_tcp_timer inp_tp_timermsg; 310 }; 311 #undef ALIGNMENT 312 #undef ALIGNM1 313 314 /* 315 * Tcp initialization 316 */ 317 void 318 tcp_init(void) 319 { 320 struct inpcbporthead *porthashbase; 321 u_long porthashmask; 322 int hashsize = TCBHASHSIZE; 323 int cpu; 324 325 /* 326 * note: tcptemp is used for keepalives, and it is ok for an 327 * allocation to fail so do not specify MPF_INT. 328 */ 329 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 330 25, -1, 0, NULL); 331 332 tcp_delacktime = TCPTV_DELACK; 333 tcp_keepinit = TCPTV_KEEP_INIT; 334 tcp_keepidle = TCPTV_KEEP_IDLE; 335 tcp_keepintvl = TCPTV_KEEPINTVL; 336 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 337 tcp_msl = TCPTV_MSL; 338 tcp_rexmit_min = TCPTV_MIN; 339 tcp_rexmit_slop = TCPTV_CPU_VAR; 340 341 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 342 if (!powerof2(hashsize)) { 343 kprintf("WARNING: TCB hash size not a power of 2\n"); 344 hashsize = 512; /* safe default */ 345 } 346 tcp_tcbhashsize = hashsize; 347 porthashbase = hashinit(hashsize, M_PCB, &porthashmask); 348 349 for (cpu = 0; cpu < ncpus2; cpu++) { 350 in_pcbinfo_init(&tcbinfo[cpu]); 351 tcbinfo[cpu].cpu = cpu; 352 tcbinfo[cpu].hashbase = hashinit(hashsize, M_PCB, 353 &tcbinfo[cpu].hashmask); 354 tcbinfo[cpu].porthashbase = porthashbase; 355 tcbinfo[cpu].porthashmask = porthashmask; 356 tcbinfo[cpu].wildcardhashbase = hashinit(hashsize, M_PCB, 357 &tcbinfo[cpu].wildcardhashmask); 358 tcbinfo[cpu].ipi_size = sizeof(struct inp_tp); 359 TAILQ_INIT(&tcpcbackq[cpu]); 360 } 361 362 tcp_reass_maxseg = nmbclusters / 16; 363 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 364 365 #ifdef INET6 366 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 367 #else 368 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 369 #endif 370 if (max_protohdr < TCP_MINPROTOHDR) 371 max_protohdr = TCP_MINPROTOHDR; 372 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 373 panic("tcp_init"); 374 #undef TCP_MINPROTOHDR 375 376 /* 377 * Initialize TCP statistics counters for each CPU. 378 */ 379 #ifdef SMP 380 for (cpu = 0; cpu < ncpus; ++cpu) { 381 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 382 } 383 #else 384 bzero(&tcpstat, sizeof(struct tcp_stats)); 385 #endif 386 387 syncache_init(); 388 netisr_register_rollup(tcp_willblock); 389 } 390 391 static void 392 tcp_willblock(void) 393 { 394 struct tcpcb *tp; 395 int cpu = mycpu->gd_cpuid; 396 397 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 398 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 399 tp->t_flags &= ~TF_ONOUTPUTQ; 400 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 401 tcp_output(tp); 402 } 403 } 404 405 /* 406 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 407 * tcp_template used to store this data in mbufs, but we now recopy it out 408 * of the tcpcb each time to conserve mbufs. 409 */ 410 void 411 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr) 412 { 413 struct inpcb *inp = tp->t_inpcb; 414 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 415 416 #ifdef INET6 417 if (inp->inp_vflag & INP_IPV6) { 418 struct ip6_hdr *ip6; 419 420 ip6 = (struct ip6_hdr *)ip_ptr; 421 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 422 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 423 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 424 (IPV6_VERSION & IPV6_VERSION_MASK); 425 ip6->ip6_nxt = IPPROTO_TCP; 426 ip6->ip6_plen = sizeof(struct tcphdr); 427 ip6->ip6_src = inp->in6p_laddr; 428 ip6->ip6_dst = inp->in6p_faddr; 429 tcp_hdr->th_sum = 0; 430 } else 431 #endif 432 { 433 struct ip *ip = (struct ip *) ip_ptr; 434 435 ip->ip_vhl = IP_VHL_BORING; 436 ip->ip_tos = 0; 437 ip->ip_len = 0; 438 ip->ip_id = 0; 439 ip->ip_off = 0; 440 ip->ip_ttl = 0; 441 ip->ip_sum = 0; 442 ip->ip_p = IPPROTO_TCP; 443 ip->ip_src = inp->inp_laddr; 444 ip->ip_dst = inp->inp_faddr; 445 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 446 ip->ip_dst.s_addr, 447 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 448 } 449 450 tcp_hdr->th_sport = inp->inp_lport; 451 tcp_hdr->th_dport = inp->inp_fport; 452 tcp_hdr->th_seq = 0; 453 tcp_hdr->th_ack = 0; 454 tcp_hdr->th_x2 = 0; 455 tcp_hdr->th_off = 5; 456 tcp_hdr->th_flags = 0; 457 tcp_hdr->th_win = 0; 458 tcp_hdr->th_urp = 0; 459 } 460 461 /* 462 * Create template to be used to send tcp packets on a connection. 463 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 464 * use for this function is in keepalives, which use tcp_respond. 465 */ 466 struct tcptemp * 467 tcp_maketemplate(struct tcpcb *tp) 468 { 469 struct tcptemp *tmp; 470 471 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 472 return (NULL); 473 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t); 474 return (tmp); 475 } 476 477 void 478 tcp_freetemplate(struct tcptemp *tmp) 479 { 480 mpipe_free(&tcptemp_mpipe, tmp); 481 } 482 483 /* 484 * Send a single message to the TCP at address specified by 485 * the given TCP/IP header. If m == NULL, then we make a copy 486 * of the tcpiphdr at ti and send directly to the addressed host. 487 * This is used to force keep alive messages out using the TCP 488 * template for a connection. If flags are given then we send 489 * a message back to the TCP which originated the * segment ti, 490 * and discard the mbuf containing it and any other attached mbufs. 491 * 492 * In any case the ack and sequence number of the transmitted 493 * segment are as specified by the parameters. 494 * 495 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 496 */ 497 void 498 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 499 tcp_seq ack, tcp_seq seq, int flags) 500 { 501 int tlen; 502 int win = 0; 503 struct route *ro = NULL; 504 struct route sro; 505 struct ip *ip = ipgen; 506 struct tcphdr *nth; 507 int ipflags = 0; 508 struct route_in6 *ro6 = NULL; 509 struct route_in6 sro6; 510 struct ip6_hdr *ip6 = ipgen; 511 boolean_t use_tmpro = TRUE; 512 #ifdef INET6 513 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 514 #else 515 const boolean_t isipv6 = FALSE; 516 #endif 517 518 if (tp != NULL) { 519 if (!(flags & TH_RST)) { 520 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 521 if (win < 0) 522 win = 0; 523 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 524 win = (long)TCP_MAXWIN << tp->rcv_scale; 525 } 526 /* 527 * Don't use the route cache of a listen socket, 528 * it is not MPSAFE; use temporary route cache. 529 */ 530 if (tp->t_state != TCPS_LISTEN) { 531 if (isipv6) 532 ro6 = &tp->t_inpcb->in6p_route; 533 else 534 ro = &tp->t_inpcb->inp_route; 535 use_tmpro = FALSE; 536 } 537 } 538 if (use_tmpro) { 539 if (isipv6) { 540 ro6 = &sro6; 541 bzero(ro6, sizeof *ro6); 542 } else { 543 ro = &sro; 544 bzero(ro, sizeof *ro); 545 } 546 } 547 if (m == NULL) { 548 m = m_gethdr(MB_DONTWAIT, MT_HEADER); 549 if (m == NULL) 550 return; 551 tlen = 0; 552 m->m_data += max_linkhdr; 553 if (isipv6) { 554 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 555 ip6 = mtod(m, struct ip6_hdr *); 556 nth = (struct tcphdr *)(ip6 + 1); 557 } else { 558 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 559 ip = mtod(m, struct ip *); 560 nth = (struct tcphdr *)(ip + 1); 561 } 562 bcopy(th, nth, sizeof(struct tcphdr)); 563 flags = TH_ACK; 564 } else { 565 m_freem(m->m_next); 566 m->m_next = NULL; 567 m->m_data = (caddr_t)ipgen; 568 /* m_len is set later */ 569 tlen = 0; 570 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 571 if (isipv6) { 572 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 573 nth = (struct tcphdr *)(ip6 + 1); 574 } else { 575 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 576 nth = (struct tcphdr *)(ip + 1); 577 } 578 if (th != nth) { 579 /* 580 * this is usually a case when an extension header 581 * exists between the IPv6 header and the 582 * TCP header. 583 */ 584 nth->th_sport = th->th_sport; 585 nth->th_dport = th->th_dport; 586 } 587 xchg(nth->th_dport, nth->th_sport, n_short); 588 #undef xchg 589 } 590 if (isipv6) { 591 ip6->ip6_flow = 0; 592 ip6->ip6_vfc = IPV6_VERSION; 593 ip6->ip6_nxt = IPPROTO_TCP; 594 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 595 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 596 } else { 597 tlen += sizeof(struct tcpiphdr); 598 ip->ip_len = tlen; 599 ip->ip_ttl = ip_defttl; 600 } 601 m->m_len = tlen; 602 m->m_pkthdr.len = tlen; 603 m->m_pkthdr.rcvif = NULL; 604 nth->th_seq = htonl(seq); 605 nth->th_ack = htonl(ack); 606 nth->th_x2 = 0; 607 nth->th_off = sizeof(struct tcphdr) >> 2; 608 nth->th_flags = flags; 609 if (tp != NULL) 610 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 611 else 612 nth->th_win = htons((u_short)win); 613 nth->th_urp = 0; 614 if (isipv6) { 615 nth->th_sum = 0; 616 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 617 sizeof(struct ip6_hdr), 618 tlen - sizeof(struct ip6_hdr)); 619 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 620 (ro6 && ro6->ro_rt) ? 621 ro6->ro_rt->rt_ifp : NULL); 622 } else { 623 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 624 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 625 m->m_pkthdr.csum_flags = CSUM_TCP; 626 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 627 } 628 #ifdef TCPDEBUG 629 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 630 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 631 #endif 632 if (isipv6) { 633 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 634 tp ? tp->t_inpcb : NULL); 635 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 636 RTFREE(ro6->ro_rt); 637 ro6->ro_rt = NULL; 638 } 639 } else { 640 ipflags |= IP_DEBUGROUTE; 641 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 642 if ((ro == &sro) && (ro->ro_rt != NULL)) { 643 RTFREE(ro->ro_rt); 644 ro->ro_rt = NULL; 645 } 646 } 647 } 648 649 /* 650 * Create a new TCP control block, making an 651 * empty reassembly queue and hooking it to the argument 652 * protocol control block. The `inp' parameter must have 653 * come from the zone allocator set up in tcp_init(). 654 */ 655 struct tcpcb * 656 tcp_newtcpcb(struct inpcb *inp) 657 { 658 struct inp_tp *it; 659 struct tcpcb *tp; 660 #ifdef INET6 661 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 662 #else 663 const boolean_t isipv6 = FALSE; 664 #endif 665 666 it = (struct inp_tp *)inp; 667 tp = &it->tcb; 668 bzero(tp, sizeof(struct tcpcb)); 669 LIST_INIT(&tp->t_segq); 670 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 671 672 /* Set up our timeouts. */ 673 tp->tt_rexmt = &it->inp_tp_rexmt; 674 tp->tt_persist = &it->inp_tp_persist; 675 tp->tt_keep = &it->inp_tp_keep; 676 tp->tt_2msl = &it->inp_tp_2msl; 677 tp->tt_delack = &it->inp_tp_delack; 678 tcp_inittimers(tp); 679 680 /* 681 * Zero out timer message. We don't create it here, 682 * since the current CPU may not be the owner of this 683 * inpcb. 684 */ 685 tp->tt_msg = &it->inp_tp_timermsg; 686 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 687 688 if (tcp_do_rfc1323) 689 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP); 690 tp->t_inpcb = inp; /* XXX */ 691 tp->t_state = TCPS_CLOSED; 692 /* 693 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 694 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 695 * reasonable initial retransmit time. 696 */ 697 tp->t_srtt = TCPTV_SRTTBASE; 698 tp->t_rttvar = 699 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 700 tp->t_rttmin = tcp_rexmit_min; 701 tp->t_rxtcur = TCPTV_RTOBASE; 702 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 703 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 704 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 705 tp->t_rcvtime = ticks; 706 /* 707 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 708 * because the socket may be bound to an IPv6 wildcard address, 709 * which may match an IPv4-mapped IPv6 address. 710 */ 711 inp->inp_ip_ttl = ip_defttl; 712 inp->inp_ppcb = tp; 713 tcp_sack_tcpcb_init(tp); 714 return (tp); /* XXX */ 715 } 716 717 /* 718 * Drop a TCP connection, reporting the specified error. 719 * If connection is synchronized, then send a RST to peer. 720 */ 721 struct tcpcb * 722 tcp_drop(struct tcpcb *tp, int error) 723 { 724 struct socket *so = tp->t_inpcb->inp_socket; 725 726 if (TCPS_HAVERCVDSYN(tp->t_state)) { 727 tp->t_state = TCPS_CLOSED; 728 tcp_output(tp); 729 tcpstat.tcps_drops++; 730 } else 731 tcpstat.tcps_conndrops++; 732 if (error == ETIMEDOUT && tp->t_softerror) 733 error = tp->t_softerror; 734 so->so_error = error; 735 return (tcp_close(tp)); 736 } 737 738 #ifdef SMP 739 740 struct netmsg_remwildcard { 741 struct netmsg nm_netmsg; 742 struct inpcb *nm_inp; 743 struct inpcbinfo *nm_pcbinfo; 744 #if defined(INET6) 745 int nm_isinet6; 746 #else 747 int nm_unused01; 748 #endif 749 }; 750 751 /* 752 * Wildcard inpcb's on SMP boxes must be removed from all cpus before the 753 * inp can be detached. We do this by cycling through the cpus, ending up 754 * on the cpu controlling the inp last and then doing the disconnect. 755 */ 756 static void 757 in_pcbremwildcardhash_handler(struct netmsg *msg0) 758 { 759 struct netmsg_remwildcard *msg = (struct netmsg_remwildcard *)msg0; 760 int cpu; 761 762 cpu = msg->nm_pcbinfo->cpu; 763 764 if (cpu == msg->nm_inp->inp_pcbinfo->cpu) { 765 /* note: detach removes any wildcard hash entry */ 766 #ifdef INET6 767 if (msg->nm_isinet6) 768 in6_pcbdetach(msg->nm_inp); 769 else 770 #endif 771 in_pcbdetach(msg->nm_inp); 772 lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, 0); 773 } else { 774 in_pcbremwildcardhash_oncpu(msg->nm_inp, msg->nm_pcbinfo); 775 cpu = (cpu + 1) % ncpus2; 776 msg->nm_pcbinfo = &tcbinfo[cpu]; 777 lwkt_forwardmsg(cpu_portfn(cpu), &msg->nm_netmsg.nm_lmsg); 778 } 779 } 780 781 #endif 782 783 /* 784 * Close a TCP control block: 785 * discard all space held by the tcp 786 * discard internet protocol block 787 * wake up any sleepers 788 */ 789 struct tcpcb * 790 tcp_close(struct tcpcb *tp) 791 { 792 struct tseg_qent *q; 793 struct inpcb *inp = tp->t_inpcb; 794 struct socket *so = inp->inp_socket; 795 struct rtentry *rt; 796 boolean_t dosavessthresh; 797 #ifdef SMP 798 int cpu; 799 #endif 800 #ifdef INET6 801 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 802 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 803 #else 804 const boolean_t isipv6 = FALSE; 805 #endif 806 807 /* 808 * The tp is not instantly destroyed in the wildcard case. Setting 809 * the state to TCPS_TERMINATING will prevent the TCP stack from 810 * messing with it, though it should be noted that this change may 811 * not take effect on other cpus until we have chained the wildcard 812 * hash removal. 813 * 814 * XXX we currently depend on the BGL to synchronize the tp->t_state 815 * update and prevent other tcp protocol threads from accepting new 816 * connections on the listen socket we might be trying to close down. 817 */ 818 KKASSERT(tp->t_state != TCPS_TERMINATING); 819 tp->t_state = TCPS_TERMINATING; 820 821 /* 822 * Make sure that all of our timers are stopped before we 823 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 824 * timers are never used. If timer message is never created 825 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 826 */ 827 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 828 tcp_callout_stop(tp, tp->tt_rexmt); 829 tcp_callout_stop(tp, tp->tt_persist); 830 tcp_callout_stop(tp, tp->tt_keep); 831 tcp_callout_stop(tp, tp->tt_2msl); 832 tcp_callout_stop(tp, tp->tt_delack); 833 } 834 835 if (tp->t_flags & TF_ONOUTPUTQ) { 836 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 837 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 838 tp->t_flags &= ~TF_ONOUTPUTQ; 839 } 840 841 /* 842 * If we got enough samples through the srtt filter, 843 * save the rtt and rttvar in the routing entry. 844 * 'Enough' is arbitrarily defined as the 16 samples. 845 * 16 samples is enough for the srtt filter to converge 846 * to within 5% of the correct value; fewer samples and 847 * we could save a very bogus rtt. 848 * 849 * Don't update the default route's characteristics and don't 850 * update anything that the user "locked". 851 */ 852 if (tp->t_rttupdated >= 16) { 853 u_long i = 0; 854 855 if (isipv6) { 856 struct sockaddr_in6 *sin6; 857 858 if ((rt = inp->in6p_route.ro_rt) == NULL) 859 goto no_valid_rt; 860 sin6 = (struct sockaddr_in6 *)rt_key(rt); 861 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 862 goto no_valid_rt; 863 } else 864 if ((rt = inp->inp_route.ro_rt) == NULL || 865 ((struct sockaddr_in *)rt_key(rt))-> 866 sin_addr.s_addr == INADDR_ANY) 867 goto no_valid_rt; 868 869 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 870 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 871 if (rt->rt_rmx.rmx_rtt && i) 872 /* 873 * filter this update to half the old & half 874 * the new values, converting scale. 875 * See route.h and tcp_var.h for a 876 * description of the scaling constants. 877 */ 878 rt->rt_rmx.rmx_rtt = 879 (rt->rt_rmx.rmx_rtt + i) / 2; 880 else 881 rt->rt_rmx.rmx_rtt = i; 882 tcpstat.tcps_cachedrtt++; 883 } 884 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 885 i = tp->t_rttvar * 886 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 887 if (rt->rt_rmx.rmx_rttvar && i) 888 rt->rt_rmx.rmx_rttvar = 889 (rt->rt_rmx.rmx_rttvar + i) / 2; 890 else 891 rt->rt_rmx.rmx_rttvar = i; 892 tcpstat.tcps_cachedrttvar++; 893 } 894 /* 895 * The old comment here said: 896 * update the pipelimit (ssthresh) if it has been updated 897 * already or if a pipesize was specified & the threshhold 898 * got below half the pipesize. I.e., wait for bad news 899 * before we start updating, then update on both good 900 * and bad news. 901 * 902 * But we want to save the ssthresh even if no pipesize is 903 * specified explicitly in the route, because such 904 * connections still have an implicit pipesize specified 905 * by the global tcp_sendspace. In the absence of a reliable 906 * way to calculate the pipesize, it will have to do. 907 */ 908 i = tp->snd_ssthresh; 909 if (rt->rt_rmx.rmx_sendpipe != 0) 910 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 911 else 912 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 913 if (dosavessthresh || 914 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 915 (rt->rt_rmx.rmx_ssthresh != 0))) { 916 /* 917 * convert the limit from user data bytes to 918 * packets then to packet data bytes. 919 */ 920 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 921 if (i < 2) 922 i = 2; 923 i *= tp->t_maxseg + 924 (isipv6 ? 925 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 926 sizeof(struct tcpiphdr)); 927 if (rt->rt_rmx.rmx_ssthresh) 928 rt->rt_rmx.rmx_ssthresh = 929 (rt->rt_rmx.rmx_ssthresh + i) / 2; 930 else 931 rt->rt_rmx.rmx_ssthresh = i; 932 tcpstat.tcps_cachedssthresh++; 933 } 934 } 935 936 no_valid_rt: 937 /* free the reassembly queue, if any */ 938 while((q = LIST_FIRST(&tp->t_segq)) != NULL) { 939 LIST_REMOVE(q, tqe_q); 940 m_freem(q->tqe_m); 941 FREE(q, M_TSEGQ); 942 atomic_add_int(&tcp_reass_qsize, -1); 943 } 944 /* throw away SACK blocks in scoreboard*/ 945 if (TCP_DO_SACK(tp)) 946 tcp_sack_cleanup(&tp->scb); 947 948 inp->inp_ppcb = NULL; 949 soisdisconnected(so); 950 951 tcp_destroy_timermsg(tp); 952 if (tp->t_flags & TF_SYNCACHE) 953 syncache_destroy(tp); 954 955 /* 956 * Discard the inp. In the SMP case a wildcard inp's hash (created 957 * by a listen socket or an INADDR_ANY udp socket) is replicated 958 * for each protocol thread and must be removed in the context of 959 * that thread. This is accomplished by chaining the message 960 * through the cpus. 961 * 962 * If the inp is not wildcarded we simply detach, which will remove 963 * the any hashes still present for this inp. 964 */ 965 #ifdef SMP 966 if (inp->inp_flags & INP_WILDCARD_MP) { 967 struct netmsg_remwildcard *msg; 968 969 cpu = (inp->inp_pcbinfo->cpu + 1) % ncpus2; 970 msg = kmalloc(sizeof(struct netmsg_remwildcard), 971 M_LWKTMSG, M_INTWAIT); 972 netmsg_init(&msg->nm_netmsg, NULL, &netisr_afree_rport, 973 0, in_pcbremwildcardhash_handler); 974 #ifdef INET6 975 msg->nm_isinet6 = isafinet6; 976 #endif 977 msg->nm_inp = inp; 978 msg->nm_pcbinfo = &tcbinfo[cpu]; 979 lwkt_sendmsg(cpu_portfn(cpu), &msg->nm_netmsg.nm_lmsg); 980 } else 981 #endif 982 { 983 /* note: detach removes any wildcard hash entry */ 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 FREE(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 nm_netmsg; 1031 struct inpcbhead *nm_head; 1032 }; 1033 1034 static void 1035 tcp_drain_handler(netmsg_t netmsg) 1036 { 1037 struct netmsg_tcp_drain *nm = (void *)netmsg; 1038 1039 tcp_drain_oncpu(nm->nm_head); 1040 lwkt_replymsg(&nm->nm_netmsg.nm_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 *msg; 1065 1066 if (cpu == mycpu->gd_cpuid) { 1067 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1068 } else { 1069 msg = kmalloc(sizeof(struct netmsg_tcp_drain), 1070 M_LWKTMSG, M_NOWAIT); 1071 if (msg == NULL) 1072 continue; 1073 netmsg_init(&msg->nm_netmsg, NULL, &netisr_afree_rport, 1074 0, tcp_drain_handler); 1075 msg->nm_head = &tcbinfo[cpu].pcblisthead; 1076 lwkt_sendmsg(cpu_portfn(cpu), &msg->nm_netmsg.nm_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 inp_gen_t gencnt; 1127 globaldata_t gd; 1128 int origcpu, ccpu; 1129 1130 error = 0; 1131 n = 0; 1132 1133 /* 1134 * The process of preparing the TCB list is too time-consuming and 1135 * resource-intensive to repeat twice on every request. 1136 */ 1137 if (req->oldptr == NULL) { 1138 for (ccpu = 0; ccpu < ncpus; ++ccpu) { 1139 gd = globaldata_find(ccpu); 1140 n += tcbinfo[gd->gd_cpuid].ipi_count; 1141 } 1142 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1143 return (0); 1144 } 1145 1146 if (req->newptr != NULL) 1147 return (EPERM); 1148 1149 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1150 marker->inp_flags |= INP_PLACEMARKER; 1151 1152 /* 1153 * OK, now we're committed to doing something. Run the inpcb list 1154 * for each cpu in the system and construct the output. Use a 1155 * list placemarker to deal with list changes occuring during 1156 * copyout blockages (but otherwise depend on being on the correct 1157 * cpu to avoid races). 1158 */ 1159 origcpu = mycpu->gd_cpuid; 1160 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) { 1161 globaldata_t rgd; 1162 caddr_t inp_ppcb; 1163 struct xtcpcb xt; 1164 int cpu_id; 1165 1166 cpu_id = (origcpu + ccpu) % ncpus; 1167 if ((smp_active_mask & (1 << cpu_id)) == 0) 1168 continue; 1169 rgd = globaldata_find(cpu_id); 1170 lwkt_setcpu_self(rgd); 1171 1172 gencnt = tcbinfo[cpu_id].ipi_gencnt; 1173 n = tcbinfo[cpu_id].ipi_count; 1174 1175 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list); 1176 i = 0; 1177 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1178 /* 1179 * process a snapshot of pcbs, ignoring placemarkers 1180 * and using our own to allow SYSCTL_OUT to block. 1181 */ 1182 LIST_REMOVE(marker, inp_list); 1183 LIST_INSERT_AFTER(inp, marker, inp_list); 1184 1185 if (inp->inp_flags & INP_PLACEMARKER) 1186 continue; 1187 if (inp->inp_gencnt > gencnt) 1188 continue; 1189 if (prison_xinpcb(req->td, inp)) 1190 continue; 1191 1192 xt.xt_len = sizeof xt; 1193 bcopy(inp, &xt.xt_inp, sizeof *inp); 1194 inp_ppcb = inp->inp_ppcb; 1195 if (inp_ppcb != NULL) 1196 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1197 else 1198 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1199 if (inp->inp_socket) 1200 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1201 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1202 break; 1203 ++i; 1204 } 1205 LIST_REMOVE(marker, inp_list); 1206 if (error == 0 && i < n) { 1207 bzero(&xt, sizeof xt); 1208 xt.xt_len = sizeof xt; 1209 while (i < n) { 1210 error = SYSCTL_OUT(req, &xt, sizeof xt); 1211 if (error) 1212 break; 1213 ++i; 1214 } 1215 } 1216 } 1217 1218 /* 1219 * Make sure we are on the same cpu we were on originally, since 1220 * higher level callers expect this. Also don't pollute caches with 1221 * migrated userland data by (eventually) returning to userland 1222 * on a different cpu. 1223 */ 1224 lwkt_setcpu_self(globaldata_find(origcpu)); 1225 kfree(marker, M_TEMP); 1226 return (error); 1227 } 1228 1229 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1230 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1231 1232 static int 1233 tcp_getcred(SYSCTL_HANDLER_ARGS) 1234 { 1235 struct sockaddr_in addrs[2]; 1236 struct inpcb *inp; 1237 int cpu; 1238 int error; 1239 1240 error = priv_check(req->td, PRIV_ROOT); 1241 if (error != 0) 1242 return (error); 1243 error = SYSCTL_IN(req, addrs, sizeof addrs); 1244 if (error != 0) 1245 return (error); 1246 crit_enter(); 1247 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1248 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1249 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1250 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1251 if (inp == NULL || inp->inp_socket == NULL) { 1252 error = ENOENT; 1253 goto out; 1254 } 1255 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1256 out: 1257 crit_exit(); 1258 return (error); 1259 } 1260 1261 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1262 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1263 1264 #ifdef INET6 1265 static int 1266 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1267 { 1268 struct sockaddr_in6 addrs[2]; 1269 struct inpcb *inp; 1270 int error; 1271 boolean_t mapped = FALSE; 1272 1273 error = priv_check(req->td, PRIV_ROOT); 1274 if (error != 0) 1275 return (error); 1276 error = SYSCTL_IN(req, addrs, sizeof addrs); 1277 if (error != 0) 1278 return (error); 1279 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1280 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1281 mapped = TRUE; 1282 else 1283 return (EINVAL); 1284 } 1285 crit_enter(); 1286 if (mapped) { 1287 inp = in_pcblookup_hash(&tcbinfo[0], 1288 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1289 addrs[1].sin6_port, 1290 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1291 addrs[0].sin6_port, 1292 0, NULL); 1293 } else { 1294 inp = in6_pcblookup_hash(&tcbinfo[0], 1295 &addrs[1].sin6_addr, addrs[1].sin6_port, 1296 &addrs[0].sin6_addr, addrs[0].sin6_port, 1297 0, NULL); 1298 } 1299 if (inp == NULL || inp->inp_socket == NULL) { 1300 error = ENOENT; 1301 goto out; 1302 } 1303 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1304 out: 1305 crit_exit(); 1306 return (error); 1307 } 1308 1309 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1310 0, 0, 1311 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1312 #endif 1313 1314 struct netmsg_tcp_notify { 1315 struct netmsg nm_nmsg; 1316 void (*nm_notify)(struct inpcb *, int); 1317 struct in_addr nm_faddr; 1318 int nm_arg; 1319 }; 1320 1321 static void 1322 tcp_notifyall_oncpu(struct netmsg *netmsg) 1323 { 1324 struct netmsg_tcp_notify *nmsg = (struct netmsg_tcp_notify *)netmsg; 1325 int nextcpu; 1326 1327 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nmsg->nm_faddr, 1328 nmsg->nm_arg, nmsg->nm_notify); 1329 1330 nextcpu = mycpuid + 1; 1331 if (nextcpu < ncpus2) 1332 lwkt_forwardmsg(cpu_portfn(nextcpu), &netmsg->nm_lmsg); 1333 else 1334 lwkt_replymsg(&netmsg->nm_lmsg, 0); 1335 } 1336 1337 void 1338 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1339 { 1340 struct ip *ip = vip; 1341 struct tcphdr *th; 1342 struct in_addr faddr; 1343 struct inpcb *inp; 1344 struct tcpcb *tp; 1345 void (*notify)(struct inpcb *, int) = tcp_notify; 1346 tcp_seq icmpseq; 1347 int arg, cpu; 1348 1349 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1350 return; 1351 } 1352 1353 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1354 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1355 return; 1356 1357 arg = inetctlerrmap[cmd]; 1358 if (cmd == PRC_QUENCH) { 1359 notify = tcp_quench; 1360 } else if (icmp_may_rst && 1361 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1362 cmd == PRC_UNREACH_PORT || 1363 cmd == PRC_TIMXCEED_INTRANS) && 1364 ip != NULL) { 1365 notify = tcp_drop_syn_sent; 1366 } else if (cmd == PRC_MSGSIZE) { 1367 struct icmp *icmp = (struct icmp *) 1368 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1369 1370 arg = ntohs(icmp->icmp_nextmtu); 1371 notify = tcp_mtudisc; 1372 } else if (PRC_IS_REDIRECT(cmd)) { 1373 ip = NULL; 1374 notify = in_rtchange; 1375 } else if (cmd == PRC_HOSTDEAD) { 1376 ip = NULL; 1377 } 1378 1379 if (ip != NULL) { 1380 crit_enter(); 1381 th = (struct tcphdr *)((caddr_t)ip + 1382 (IP_VHL_HL(ip->ip_vhl) << 2)); 1383 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1384 ip->ip_src.s_addr, th->th_sport); 1385 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1386 ip->ip_src, th->th_sport, 0, NULL); 1387 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1388 icmpseq = htonl(th->th_seq); 1389 tp = intotcpcb(inp); 1390 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1391 SEQ_LT(icmpseq, tp->snd_max)) 1392 (*notify)(inp, arg); 1393 } else { 1394 struct in_conninfo inc; 1395 1396 inc.inc_fport = th->th_dport; 1397 inc.inc_lport = th->th_sport; 1398 inc.inc_faddr = faddr; 1399 inc.inc_laddr = ip->ip_src; 1400 #ifdef INET6 1401 inc.inc_isipv6 = 0; 1402 #endif 1403 syncache_unreach(&inc, th); 1404 } 1405 crit_exit(); 1406 } else { 1407 struct netmsg_tcp_notify nmsg; 1408 1409 KKASSERT(&curthread->td_msgport == cpu_portfn(0)); 1410 netmsg_init(&nmsg.nm_nmsg, NULL, &curthread->td_msgport, 1411 0, tcp_notifyall_oncpu); 1412 nmsg.nm_faddr = faddr; 1413 nmsg.nm_arg = arg; 1414 nmsg.nm_notify = notify; 1415 1416 lwkt_domsg(cpu_portfn(0), &nmsg.nm_nmsg.nm_lmsg, 0); 1417 } 1418 } 1419 1420 #ifdef INET6 1421 void 1422 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1423 { 1424 struct tcphdr th; 1425 void (*notify) (struct inpcb *, int) = tcp_notify; 1426 struct ip6_hdr *ip6; 1427 struct mbuf *m; 1428 struct ip6ctlparam *ip6cp = NULL; 1429 const struct sockaddr_in6 *sa6_src = NULL; 1430 int off; 1431 struct tcp_portonly { 1432 u_int16_t th_sport; 1433 u_int16_t th_dport; 1434 } *thp; 1435 int arg; 1436 1437 if (sa->sa_family != AF_INET6 || 1438 sa->sa_len != sizeof(struct sockaddr_in6)) 1439 return; 1440 1441 arg = 0; 1442 if (cmd == PRC_QUENCH) 1443 notify = tcp_quench; 1444 else if (cmd == PRC_MSGSIZE) { 1445 struct ip6ctlparam *ip6cp = d; 1446 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1447 1448 arg = ntohl(icmp6->icmp6_mtu); 1449 notify = tcp_mtudisc; 1450 } else if (!PRC_IS_REDIRECT(cmd) && 1451 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1452 return; 1453 } 1454 1455 /* if the parameter is from icmp6, decode it. */ 1456 if (d != NULL) { 1457 ip6cp = (struct ip6ctlparam *)d; 1458 m = ip6cp->ip6c_m; 1459 ip6 = ip6cp->ip6c_ip6; 1460 off = ip6cp->ip6c_off; 1461 sa6_src = ip6cp->ip6c_src; 1462 } else { 1463 m = NULL; 1464 ip6 = NULL; 1465 off = 0; /* fool gcc */ 1466 sa6_src = &sa6_any; 1467 } 1468 1469 if (ip6 != NULL) { 1470 struct in_conninfo inc; 1471 /* 1472 * XXX: We assume that when IPV6 is non NULL, 1473 * M and OFF are valid. 1474 */ 1475 1476 /* check if we can safely examine src and dst ports */ 1477 if (m->m_pkthdr.len < off + sizeof *thp) 1478 return; 1479 1480 bzero(&th, sizeof th); 1481 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1482 1483 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1484 (struct sockaddr *)ip6cp->ip6c_src, 1485 th.th_sport, cmd, arg, notify); 1486 1487 inc.inc_fport = th.th_dport; 1488 inc.inc_lport = th.th_sport; 1489 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1490 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1491 inc.inc_isipv6 = 1; 1492 syncache_unreach(&inc, &th); 1493 } else 1494 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1495 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1496 } 1497 #endif 1498 1499 /* 1500 * Following is where TCP initial sequence number generation occurs. 1501 * 1502 * There are two places where we must use initial sequence numbers: 1503 * 1. In SYN-ACK packets. 1504 * 2. In SYN packets. 1505 * 1506 * All ISNs for SYN-ACK packets are generated by the syncache. See 1507 * tcp_syncache.c for details. 1508 * 1509 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1510 * depends on this property. In addition, these ISNs should be 1511 * unguessable so as to prevent connection hijacking. To satisfy 1512 * the requirements of this situation, the algorithm outlined in 1513 * RFC 1948 is used to generate sequence numbers. 1514 * 1515 * Implementation details: 1516 * 1517 * Time is based off the system timer, and is corrected so that it 1518 * increases by one megabyte per second. This allows for proper 1519 * recycling on high speed LANs while still leaving over an hour 1520 * before rollover. 1521 * 1522 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1523 * between seeding of isn_secret. This is normally set to zero, 1524 * as reseeding should not be necessary. 1525 * 1526 */ 1527 1528 #define ISN_BYTES_PER_SECOND 1048576 1529 1530 u_char isn_secret[32]; 1531 int isn_last_reseed; 1532 MD5_CTX isn_ctx; 1533 1534 tcp_seq 1535 tcp_new_isn(struct tcpcb *tp) 1536 { 1537 u_int32_t md5_buffer[4]; 1538 tcp_seq new_isn; 1539 1540 /* Seed if this is the first use, reseed if requested. */ 1541 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1542 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1543 < (u_int)ticks))) { 1544 read_random_unlimited(&isn_secret, sizeof isn_secret); 1545 isn_last_reseed = ticks; 1546 } 1547 1548 /* Compute the md5 hash and return the ISN. */ 1549 MD5Init(&isn_ctx); 1550 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1551 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1552 #ifdef INET6 1553 if (tp->t_inpcb->inp_vflag & INP_IPV6) { 1554 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1555 sizeof(struct in6_addr)); 1556 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1557 sizeof(struct in6_addr)); 1558 } else 1559 #endif 1560 { 1561 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1562 sizeof(struct in_addr)); 1563 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1564 sizeof(struct in_addr)); 1565 } 1566 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1567 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1568 new_isn = (tcp_seq) md5_buffer[0]; 1569 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1570 return (new_isn); 1571 } 1572 1573 /* 1574 * When a source quench is received, close congestion window 1575 * to one segment. We will gradually open it again as we proceed. 1576 */ 1577 void 1578 tcp_quench(struct inpcb *inp, int error) 1579 { 1580 struct tcpcb *tp = intotcpcb(inp); 1581 1582 if (tp != NULL) { 1583 tp->snd_cwnd = tp->t_maxseg; 1584 tp->snd_wacked = 0; 1585 } 1586 } 1587 1588 /* 1589 * When a specific ICMP unreachable message is received and the 1590 * connection state is SYN-SENT, drop the connection. This behavior 1591 * is controlled by the icmp_may_rst sysctl. 1592 */ 1593 void 1594 tcp_drop_syn_sent(struct inpcb *inp, int error) 1595 { 1596 struct tcpcb *tp = intotcpcb(inp); 1597 1598 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT)) 1599 tcp_drop(tp, error); 1600 } 1601 1602 /* 1603 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1604 * based on the new value in the route. Also nudge TCP to send something, 1605 * since we know the packet we just sent was dropped. 1606 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1607 */ 1608 void 1609 tcp_mtudisc(struct inpcb *inp, int mtu) 1610 { 1611 struct tcpcb *tp = intotcpcb(inp); 1612 struct rtentry *rt; 1613 struct socket *so = inp->inp_socket; 1614 int maxopd, mss; 1615 #ifdef INET6 1616 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0); 1617 #else 1618 const boolean_t isipv6 = FALSE; 1619 #endif 1620 1621 if (tp == NULL) 1622 return; 1623 1624 /* 1625 * If no MTU is provided in the ICMP message, use the 1626 * next lower likely value, as specified in RFC 1191. 1627 */ 1628 if (mtu == 0) { 1629 int oldmtu; 1630 1631 oldmtu = tp->t_maxopd + 1632 (isipv6 ? 1633 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1634 sizeof(struct tcpiphdr)); 1635 mtu = ip_next_mtu(oldmtu, 0); 1636 } 1637 1638 if (isipv6) 1639 rt = tcp_rtlookup6(&inp->inp_inc); 1640 else 1641 rt = tcp_rtlookup(&inp->inp_inc); 1642 if (rt != NULL) { 1643 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1644 mtu = rt->rt_rmx.rmx_mtu; 1645 1646 maxopd = mtu - 1647 (isipv6 ? 1648 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1649 sizeof(struct tcpiphdr)); 1650 1651 /* 1652 * XXX - The following conditional probably violates the TCP 1653 * spec. The problem is that, since we don't know the 1654 * other end's MSS, we are supposed to use a conservative 1655 * default. But, if we do that, then MTU discovery will 1656 * never actually take place, because the conservative 1657 * default is much less than the MTUs typically seen 1658 * on the Internet today. For the moment, we'll sweep 1659 * this under the carpet. 1660 * 1661 * The conservative default might not actually be a problem 1662 * if the only case this occurs is when sending an initial 1663 * SYN with options and data to a host we've never talked 1664 * to before. Then, they will reply with an MSS value which 1665 * will get recorded and the new parameters should get 1666 * recomputed. For Further Study. 1667 */ 1668 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1669 maxopd = rt->rt_rmx.rmx_mssopt; 1670 } else 1671 maxopd = mtu - 1672 (isipv6 ? 1673 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1674 sizeof(struct tcpiphdr)); 1675 1676 if (tp->t_maxopd <= maxopd) 1677 return; 1678 tp->t_maxopd = maxopd; 1679 1680 mss = maxopd; 1681 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1682 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1683 mss -= TCPOLEN_TSTAMP_APPA; 1684 1685 /* round down to multiple of MCLBYTES */ 1686 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1687 if (mss > MCLBYTES) 1688 mss &= ~(MCLBYTES - 1); 1689 #else 1690 if (mss > MCLBYTES) 1691 mss = (mss / MCLBYTES) * MCLBYTES; 1692 #endif 1693 1694 if (so->so_snd.ssb_hiwat < mss) 1695 mss = so->so_snd.ssb_hiwat; 1696 1697 tp->t_maxseg = mss; 1698 tp->t_rtttime = 0; 1699 tp->snd_nxt = tp->snd_una; 1700 tcp_output(tp); 1701 tcpstat.tcps_mturesent++; 1702 } 1703 1704 /* 1705 * Look-up the routing entry to the peer of this inpcb. If no route 1706 * is found and it cannot be allocated the return NULL. This routine 1707 * is called by TCP routines that access the rmx structure and by tcp_mss 1708 * to get the interface MTU. 1709 */ 1710 struct rtentry * 1711 tcp_rtlookup(struct in_conninfo *inc) 1712 { 1713 struct route *ro = &inc->inc_route; 1714 1715 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1716 /* No route yet, so try to acquire one */ 1717 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1718 /* 1719 * unused portions of the structure MUST be zero'd 1720 * out because rtalloc() treats it as opaque data 1721 */ 1722 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1723 ro->ro_dst.sa_family = AF_INET; 1724 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1725 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1726 inc->inc_faddr; 1727 rtalloc(ro); 1728 } 1729 } 1730 return (ro->ro_rt); 1731 } 1732 1733 #ifdef INET6 1734 struct rtentry * 1735 tcp_rtlookup6(struct in_conninfo *inc) 1736 { 1737 struct route_in6 *ro6 = &inc->inc6_route; 1738 1739 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1740 /* No route yet, so try to acquire one */ 1741 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1742 /* 1743 * unused portions of the structure MUST be zero'd 1744 * out because rtalloc() treats it as opaque data 1745 */ 1746 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1747 ro6->ro_dst.sin6_family = AF_INET6; 1748 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1749 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1750 rtalloc((struct route *)ro6); 1751 } 1752 } 1753 return (ro6->ro_rt); 1754 } 1755 #endif 1756 1757 #ifdef IPSEC 1758 /* compute ESP/AH header size for TCP, including outer IP header. */ 1759 size_t 1760 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1761 { 1762 struct inpcb *inp; 1763 struct mbuf *m; 1764 size_t hdrsiz; 1765 struct ip *ip; 1766 struct tcphdr *th; 1767 1768 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1769 return (0); 1770 MGETHDR(m, MB_DONTWAIT, MT_DATA); 1771 if (!m) 1772 return (0); 1773 1774 #ifdef INET6 1775 if (inp->inp_vflag & INP_IPV6) { 1776 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1777 1778 th = (struct tcphdr *)(ip6 + 1); 1779 m->m_pkthdr.len = m->m_len = 1780 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1781 tcp_fillheaders(tp, ip6, th); 1782 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1783 } else 1784 #endif 1785 { 1786 ip = mtod(m, struct ip *); 1787 th = (struct tcphdr *)(ip + 1); 1788 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1789 tcp_fillheaders(tp, ip, th); 1790 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1791 } 1792 1793 m_free(m); 1794 return (hdrsiz); 1795 } 1796 #endif 1797 1798 /* 1799 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1800 * 1801 * This code attempts to calculate the bandwidth-delay product as a 1802 * means of determining the optimal window size to maximize bandwidth, 1803 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1804 * routers. This code also does a fairly good job keeping RTTs in check 1805 * across slow links like modems. We implement an algorithm which is very 1806 * similar (but not meant to be) TCP/Vegas. The code operates on the 1807 * transmitter side of a TCP connection and so only effects the transmit 1808 * side of the connection. 1809 * 1810 * BACKGROUND: TCP makes no provision for the management of buffer space 1811 * at the end points or at the intermediate routers and switches. A TCP 1812 * stream, whether using NewReno or not, will eventually buffer as 1813 * many packets as it is able and the only reason this typically works is 1814 * due to the fairly small default buffers made available for a connection 1815 * (typicaly 16K or 32K). As machines use larger windows and/or window 1816 * scaling it is now fairly easy for even a single TCP connection to blow-out 1817 * all available buffer space not only on the local interface, but on 1818 * intermediate routers and switches as well. NewReno makes a misguided 1819 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1820 * then backing off, then steadily increasing the window again until another 1821 * failure occurs, ad-infinitum. This results in terrible oscillation that 1822 * is only made worse as network loads increase and the idea of intentionally 1823 * blowing out network buffers is, frankly, a terrible way to manage network 1824 * resources. 1825 * 1826 * It is far better to limit the transmit window prior to the failure 1827 * condition being achieved. There are two general ways to do this: First 1828 * you can 'scan' through different transmit window sizes and locate the 1829 * point where the RTT stops increasing, indicating that you have filled the 1830 * pipe, then scan backwards until you note that RTT stops decreasing, then 1831 * repeat ad-infinitum. This method works in principle but has severe 1832 * implementation issues due to RTT variances, timer granularity, and 1833 * instability in the algorithm which can lead to many false positives and 1834 * create oscillations as well as interact badly with other TCP streams 1835 * implementing the same algorithm. 1836 * 1837 * The second method is to limit the window to the bandwidth delay product 1838 * of the link. This is the method we implement. RTT variances and our 1839 * own manipulation of the congestion window, bwnd, can potentially 1840 * destabilize the algorithm. For this reason we have to stabilize the 1841 * elements used to calculate the window. We do this by using the minimum 1842 * observed RTT, the long term average of the observed bandwidth, and 1843 * by adding two segments worth of slop. It isn't perfect but it is able 1844 * to react to changing conditions and gives us a very stable basis on 1845 * which to extend the algorithm. 1846 */ 1847 void 1848 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1849 { 1850 u_long bw; 1851 u_long bwnd; 1852 int save_ticks; 1853 int delta_ticks; 1854 1855 /* 1856 * If inflight_enable is disabled in the middle of a tcp connection, 1857 * make sure snd_bwnd is effectively disabled. 1858 */ 1859 if (!tcp_inflight_enable) { 1860 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1861 tp->snd_bandwidth = 0; 1862 return; 1863 } 1864 1865 /* 1866 * Validate the delta time. If a connection is new or has been idle 1867 * a long time we have to reset the bandwidth calculator. 1868 */ 1869 save_ticks = ticks; 1870 delta_ticks = save_ticks - tp->t_bw_rtttime; 1871 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1872 tp->t_bw_rtttime = ticks; 1873 tp->t_bw_rtseq = ack_seq; 1874 if (tp->snd_bandwidth == 0) 1875 tp->snd_bandwidth = tcp_inflight_min; 1876 return; 1877 } 1878 if (delta_ticks == 0) 1879 return; 1880 1881 /* 1882 * Sanity check, plus ignore pure window update acks. 1883 */ 1884 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1885 return; 1886 1887 /* 1888 * Figure out the bandwidth. Due to the tick granularity this 1889 * is a very rough number and it MUST be averaged over a fairly 1890 * long period of time. XXX we need to take into account a link 1891 * that is not using all available bandwidth, but for now our 1892 * slop will ramp us up if this case occurs and the bandwidth later 1893 * increases. 1894 */ 1895 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 1896 tp->t_bw_rtttime = save_ticks; 1897 tp->t_bw_rtseq = ack_seq; 1898 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1899 1900 tp->snd_bandwidth = bw; 1901 1902 /* 1903 * Calculate the semi-static bandwidth delay product, plus two maximal 1904 * segments. The additional slop puts us squarely in the sweet 1905 * spot and also handles the bandwidth run-up case. Without the 1906 * slop we could be locking ourselves into a lower bandwidth. 1907 * 1908 * Situations Handled: 1909 * (1) Prevents over-queueing of packets on LANs, especially on 1910 * high speed LANs, allowing larger TCP buffers to be 1911 * specified, and also does a good job preventing 1912 * over-queueing of packets over choke points like modems 1913 * (at least for the transmit side). 1914 * 1915 * (2) Is able to handle changing network loads (bandwidth 1916 * drops so bwnd drops, bandwidth increases so bwnd 1917 * increases). 1918 * 1919 * (3) Theoretically should stabilize in the face of multiple 1920 * connections implementing the same algorithm (this may need 1921 * a little work). 1922 * 1923 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1924 * be adjusted with a sysctl but typically only needs to be on 1925 * very slow connections. A value no smaller then 5 should 1926 * be used, but only reduce this default if you have no other 1927 * choice. 1928 */ 1929 1930 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1931 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 1932 tcp_inflight_stab * (int)tp->t_maxseg / 10; 1933 #undef USERTT 1934 1935 if (tcp_inflight_debug > 0) { 1936 static int ltime; 1937 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1938 ltime = ticks; 1939 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1940 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd); 1941 } 1942 } 1943 if ((long)bwnd < tcp_inflight_min) 1944 bwnd = tcp_inflight_min; 1945 if (bwnd > tcp_inflight_max) 1946 bwnd = tcp_inflight_max; 1947 if ((long)bwnd < tp->t_maxseg * 2) 1948 bwnd = tp->t_maxseg * 2; 1949 tp->snd_bwnd = bwnd; 1950 } 1951 1952 #ifdef TCP_SIGNATURE 1953 /* 1954 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1955 * 1956 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1957 * When called from tcp_input(), we can be sure that th_sum has been 1958 * zeroed out and verified already. 1959 * 1960 * Return 0 if successful, otherwise return -1. 1961 * 1962 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1963 * search with the destination IP address, and a 'magic SPI' to be 1964 * determined by the application. This is hardcoded elsewhere to 1179 1965 * right now. Another branch of this code exists which uses the SPD to 1966 * specify per-application flows but it is unstable. 1967 */ 1968 int 1969 tcpsignature_compute( 1970 struct mbuf *m, /* mbuf chain */ 1971 int len, /* length of TCP data */ 1972 int optlen, /* length of TCP options */ 1973 u_char *buf, /* storage for MD5 digest */ 1974 u_int direction) /* direction of flow */ 1975 { 1976 struct ippseudo ippseudo; 1977 MD5_CTX ctx; 1978 int doff; 1979 struct ip *ip; 1980 struct ipovly *ipovly; 1981 struct secasvar *sav; 1982 struct tcphdr *th; 1983 #ifdef INET6 1984 struct ip6_hdr *ip6; 1985 struct in6_addr in6; 1986 uint32_t plen; 1987 uint16_t nhdr; 1988 #endif /* INET6 */ 1989 u_short savecsum; 1990 1991 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 1992 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 1993 /* 1994 * Extract the destination from the IP header in the mbuf. 1995 */ 1996 ip = mtod(m, struct ip *); 1997 #ifdef INET6 1998 ip6 = NULL; /* Make the compiler happy. */ 1999 #endif /* INET6 */ 2000 /* 2001 * Look up an SADB entry which matches the address found in 2002 * the segment. 2003 */ 2004 switch (IP_VHL_V(ip->ip_vhl)) { 2005 case IPVERSION: 2006 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2007 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2008 break; 2009 #ifdef INET6 2010 case (IPV6_VERSION >> 4): 2011 ip6 = mtod(m, struct ip6_hdr *); 2012 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2013 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2014 break; 2015 #endif /* INET6 */ 2016 default: 2017 return (EINVAL); 2018 /* NOTREACHED */ 2019 break; 2020 } 2021 if (sav == NULL) { 2022 kprintf("%s: SADB lookup failed\n", __func__); 2023 return (EINVAL); 2024 } 2025 MD5Init(&ctx); 2026 2027 /* 2028 * Step 1: Update MD5 hash with IP pseudo-header. 2029 * 2030 * XXX The ippseudo header MUST be digested in network byte order, 2031 * or else we'll fail the regression test. Assume all fields we've 2032 * been doing arithmetic on have been in host byte order. 2033 * XXX One cannot depend on ipovly->ih_len here. When called from 2034 * tcp_output(), the underlying ip_len member has not yet been set. 2035 */ 2036 switch (IP_VHL_V(ip->ip_vhl)) { 2037 case IPVERSION: 2038 ipovly = (struct ipovly *)ip; 2039 ippseudo.ippseudo_src = ipovly->ih_src; 2040 ippseudo.ippseudo_dst = ipovly->ih_dst; 2041 ippseudo.ippseudo_pad = 0; 2042 ippseudo.ippseudo_p = IPPROTO_TCP; 2043 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2044 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2045 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2046 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2047 break; 2048 #ifdef INET6 2049 /* 2050 * RFC 2385, 2.0 Proposal 2051 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2052 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2053 * extended next header value (to form 32 bits), and 32-bit segment 2054 * length. 2055 * Note: Upper-Layer Packet Length comes before Next Header. 2056 */ 2057 case (IPV6_VERSION >> 4): 2058 in6 = ip6->ip6_src; 2059 in6_clearscope(&in6); 2060 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2061 in6 = ip6->ip6_dst; 2062 in6_clearscope(&in6); 2063 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2064 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2065 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2066 nhdr = 0; 2067 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2068 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2069 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2070 nhdr = IPPROTO_TCP; 2071 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2072 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2073 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2074 break; 2075 #endif /* INET6 */ 2076 default: 2077 return (EINVAL); 2078 /* NOTREACHED */ 2079 break; 2080 } 2081 /* 2082 * Step 2: Update MD5 hash with TCP header, excluding options. 2083 * The TCP checksum must be set to zero. 2084 */ 2085 savecsum = th->th_sum; 2086 th->th_sum = 0; 2087 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2088 th->th_sum = savecsum; 2089 /* 2090 * Step 3: Update MD5 hash with TCP segment data. 2091 * Use m_apply() to avoid an early m_pullup(). 2092 */ 2093 if (len > 0) 2094 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2095 /* 2096 * Step 4: Update MD5 hash with shared secret. 2097 */ 2098 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2099 MD5Final(buf, &ctx); 2100 key_sa_recordxfer(sav, m); 2101 key_freesav(sav); 2102 return (0); 2103 } 2104 2105 int 2106 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2107 { 2108 2109 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2110 return (0); 2111 } 2112 #endif /* TCP_SIGNATURE */ 2113