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 if (tcp_do_rfc1323) 698 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP); 699 tp->t_inpcb = inp; /* XXX */ 700 tp->t_state = TCPS_CLOSED; 701 /* 702 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 703 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 704 * reasonable initial retransmit time. 705 */ 706 tp->t_srtt = TCPTV_SRTTBASE; 707 tp->t_rttvar = 708 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 709 tp->t_rttmin = tcp_rexmit_min; 710 tp->t_rxtcur = TCPTV_RTOBASE; 711 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 712 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 713 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 714 tp->t_rcvtime = ticks; 715 /* 716 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 717 * because the socket may be bound to an IPv6 wildcard address, 718 * which may match an IPv4-mapped IPv6 address. 719 */ 720 inp->inp_ip_ttl = ip_defttl; 721 inp->inp_ppcb = tp; 722 tcp_sack_tcpcb_init(tp); 723 return (tp); /* XXX */ 724 } 725 726 /* 727 * Drop a TCP connection, reporting the specified error. 728 * If connection is synchronized, then send a RST to peer. 729 */ 730 struct tcpcb * 731 tcp_drop(struct tcpcb *tp, int error) 732 { 733 struct socket *so = tp->t_inpcb->inp_socket; 734 735 if (TCPS_HAVERCVDSYN(tp->t_state)) { 736 tp->t_state = TCPS_CLOSED; 737 tcp_output(tp); 738 tcpstat.tcps_drops++; 739 } else 740 tcpstat.tcps_conndrops++; 741 if (error == ETIMEDOUT && tp->t_softerror) 742 error = tp->t_softerror; 743 so->so_error = error; 744 return (tcp_close(tp)); 745 } 746 747 #ifdef SMP 748 749 struct netmsg_listen_detach { 750 struct netmsg_base base; 751 struct tcpcb *nm_tp; 752 }; 753 754 static void 755 tcp_listen_detach_handler(netmsg_t msg) 756 { 757 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; 758 struct tcpcb *tp = nmsg->nm_tp; 759 int cpu = mycpuid, nextcpu; 760 761 if (tp->t_flags & TF_LISTEN) 762 syncache_destroy(tp); 763 764 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); 765 766 nextcpu = cpu + 1; 767 if (nextcpu < ncpus2) 768 lwkt_forwardmsg(cpu_portfn(nextcpu), &nmsg->base.lmsg); 769 else 770 lwkt_replymsg(&nmsg->base.lmsg, 0); 771 } 772 773 #endif 774 775 /* 776 * Close a TCP control block: 777 * discard all space held by the tcp 778 * discard internet protocol block 779 * wake up any sleepers 780 */ 781 struct tcpcb * 782 tcp_close(struct tcpcb *tp) 783 { 784 struct tseg_qent *q; 785 struct inpcb *inp = tp->t_inpcb; 786 struct socket *so = inp->inp_socket; 787 struct rtentry *rt; 788 boolean_t dosavessthresh; 789 #ifdef INET6 790 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 791 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 792 #else 793 const boolean_t isipv6 = FALSE; 794 #endif 795 796 #ifdef SMP 797 /* 798 * INP_WILDCARD_MP indicates that listen(2) has been called on 799 * this socket. This implies: 800 * - A wildcard inp's hash is replicated for each protocol thread. 801 * - Syncache for this inp grows independently in each protocol 802 * thread. 803 * - There is more than one cpu 804 * 805 * We have to chain a message to the rest of the protocol threads 806 * to cleanup the wildcard hash and the syncache. The cleanup 807 * in the current protocol thread is defered till the end of this 808 * function. 809 * 810 * NOTE: 811 * After cleanup the inp's hash and syncache entries, this inp will 812 * no longer be available to the rest of the protocol threads, so we 813 * are safe to whack the inp in the following code. 814 */ 815 if (inp->inp_flags & INP_WILDCARD_MP) { 816 struct netmsg_listen_detach nmsg; 817 818 KKASSERT(so->so_port == cpu_portfn(0)); 819 KKASSERT(&curthread->td_msgport == cpu_portfn(0)); 820 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); 821 822 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, 823 MSGF_PRIORITY, tcp_listen_detach_handler); 824 nmsg.nm_tp = tp; 825 lwkt_domsg(cpu_portfn(1), &nmsg.base.lmsg, 0); 826 827 inp->inp_flags &= ~INP_WILDCARD_MP; 828 } 829 #endif 830 831 KKASSERT(tp->t_state != TCPS_TERMINATING); 832 tp->t_state = TCPS_TERMINATING; 833 834 /* 835 * Make sure that all of our timers are stopped before we 836 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 837 * timers are never used. If timer message is never created 838 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 839 */ 840 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 841 tcp_callout_stop(tp, tp->tt_rexmt); 842 tcp_callout_stop(tp, tp->tt_persist); 843 tcp_callout_stop(tp, tp->tt_keep); 844 tcp_callout_stop(tp, tp->tt_2msl); 845 tcp_callout_stop(tp, tp->tt_delack); 846 } 847 848 if (tp->t_flags & TF_ONOUTPUTQ) { 849 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 850 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 851 tp->t_flags &= ~TF_ONOUTPUTQ; 852 } 853 854 /* 855 * If we got enough samples through the srtt filter, 856 * save the rtt and rttvar in the routing entry. 857 * 'Enough' is arbitrarily defined as the 16 samples. 858 * 16 samples is enough for the srtt filter to converge 859 * to within 5% of the correct value; fewer samples and 860 * we could save a very bogus rtt. 861 * 862 * Don't update the default route's characteristics and don't 863 * update anything that the user "locked". 864 */ 865 if (tp->t_rttupdated >= 16) { 866 u_long i = 0; 867 868 if (isipv6) { 869 struct sockaddr_in6 *sin6; 870 871 if ((rt = inp->in6p_route.ro_rt) == NULL) 872 goto no_valid_rt; 873 sin6 = (struct sockaddr_in6 *)rt_key(rt); 874 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 875 goto no_valid_rt; 876 } else 877 if ((rt = inp->inp_route.ro_rt) == NULL || 878 ((struct sockaddr_in *)rt_key(rt))-> 879 sin_addr.s_addr == INADDR_ANY) 880 goto no_valid_rt; 881 882 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 883 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 884 if (rt->rt_rmx.rmx_rtt && i) 885 /* 886 * filter this update to half the old & half 887 * the new values, converting scale. 888 * See route.h and tcp_var.h for a 889 * description of the scaling constants. 890 */ 891 rt->rt_rmx.rmx_rtt = 892 (rt->rt_rmx.rmx_rtt + i) / 2; 893 else 894 rt->rt_rmx.rmx_rtt = i; 895 tcpstat.tcps_cachedrtt++; 896 } 897 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 898 i = tp->t_rttvar * 899 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 900 if (rt->rt_rmx.rmx_rttvar && i) 901 rt->rt_rmx.rmx_rttvar = 902 (rt->rt_rmx.rmx_rttvar + i) / 2; 903 else 904 rt->rt_rmx.rmx_rttvar = i; 905 tcpstat.tcps_cachedrttvar++; 906 } 907 /* 908 * The old comment here said: 909 * update the pipelimit (ssthresh) if it has been updated 910 * already or if a pipesize was specified & the threshhold 911 * got below half the pipesize. I.e., wait for bad news 912 * before we start updating, then update on both good 913 * and bad news. 914 * 915 * But we want to save the ssthresh even if no pipesize is 916 * specified explicitly in the route, because such 917 * connections still have an implicit pipesize specified 918 * by the global tcp_sendspace. In the absence of a reliable 919 * way to calculate the pipesize, it will have to do. 920 */ 921 i = tp->snd_ssthresh; 922 if (rt->rt_rmx.rmx_sendpipe != 0) 923 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 924 else 925 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 926 if (dosavessthresh || 927 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 928 (rt->rt_rmx.rmx_ssthresh != 0))) { 929 /* 930 * convert the limit from user data bytes to 931 * packets then to packet data bytes. 932 */ 933 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 934 if (i < 2) 935 i = 2; 936 i *= tp->t_maxseg + 937 (isipv6 ? 938 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 939 sizeof(struct tcpiphdr)); 940 if (rt->rt_rmx.rmx_ssthresh) 941 rt->rt_rmx.rmx_ssthresh = 942 (rt->rt_rmx.rmx_ssthresh + i) / 2; 943 else 944 rt->rt_rmx.rmx_ssthresh = i; 945 tcpstat.tcps_cachedssthresh++; 946 } 947 } 948 949 no_valid_rt: 950 /* free the reassembly queue, if any */ 951 while((q = LIST_FIRST(&tp->t_segq)) != NULL) { 952 LIST_REMOVE(q, tqe_q); 953 m_freem(q->tqe_m); 954 FREE(q, M_TSEGQ); 955 atomic_add_int(&tcp_reass_qsize, -1); 956 } 957 /* throw away SACK blocks in scoreboard*/ 958 if (TCP_DO_SACK(tp)) 959 tcp_sack_cleanup(&tp->scb); 960 961 inp->inp_ppcb = NULL; 962 soisdisconnected(so); 963 /* note: pcb detached later on */ 964 965 tcp_destroy_timermsg(tp); 966 967 if (tp->t_flags & TF_LISTEN) 968 syncache_destroy(tp); 969 970 /* 971 * NOTE: 972 * pcbdetach removes any wildcard hash entry on the current CPU. 973 */ 974 #ifdef INET6 975 if (isafinet6) 976 in6_pcbdetach(inp); 977 else 978 #endif 979 in_pcbdetach(inp); 980 981 tcpstat.tcps_closed++; 982 return (NULL); 983 } 984 985 static __inline void 986 tcp_drain_oncpu(struct inpcbhead *head) 987 { 988 struct inpcb *marker; 989 struct inpcb *inpb; 990 struct tcpcb *tcpb; 991 struct tseg_qent *te; 992 993 /* 994 * Allows us to block while running the list 995 */ 996 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 997 marker->inp_flags |= INP_PLACEMARKER; 998 LIST_INSERT_HEAD(head, marker, inp_list); 999 1000 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) { 1001 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 && 1002 (tcpb = intotcpcb(inpb)) != NULL && 1003 (te = LIST_FIRST(&tcpb->t_segq)) != NULL) { 1004 LIST_REMOVE(te, tqe_q); 1005 m_freem(te->tqe_m); 1006 FREE(te, M_TSEGQ); 1007 atomic_add_int(&tcp_reass_qsize, -1); 1008 /* retry */ 1009 } else { 1010 LIST_REMOVE(marker, inp_list); 1011 LIST_INSERT_AFTER(inpb, marker, inp_list); 1012 } 1013 } 1014 LIST_REMOVE(marker, inp_list); 1015 kfree(marker, M_TEMP); 1016 } 1017 1018 #ifdef SMP 1019 struct netmsg_tcp_drain { 1020 struct netmsg_base base; 1021 struct inpcbhead *nm_head; 1022 }; 1023 1024 static void 1025 tcp_drain_handler(netmsg_t msg) 1026 { 1027 struct netmsg_tcp_drain *nm = (void *)msg; 1028 1029 tcp_drain_oncpu(nm->nm_head); 1030 lwkt_replymsg(&nm->base.lmsg, 0); 1031 } 1032 #endif 1033 1034 void 1035 tcp_drain(void) 1036 { 1037 #ifdef SMP 1038 int cpu; 1039 #endif 1040 1041 if (!do_tcpdrain) 1042 return; 1043 1044 /* 1045 * Walk the tcpbs, if existing, and flush the reassembly queue, 1046 * if there is one... 1047 * XXX: The "Net/3" implementation doesn't imply that the TCP 1048 * reassembly queue should be flushed, but in a situation 1049 * where we're really low on mbufs, this is potentially 1050 * useful. 1051 */ 1052 #ifdef SMP 1053 for (cpu = 0; cpu < ncpus2; cpu++) { 1054 struct netmsg_tcp_drain *nm; 1055 1056 if (cpu == mycpu->gd_cpuid) { 1057 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1058 } else { 1059 nm = kmalloc(sizeof(struct netmsg_tcp_drain), 1060 M_LWKTMSG, M_NOWAIT); 1061 if (nm == NULL) 1062 continue; 1063 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1064 0, tcp_drain_handler); 1065 nm->nm_head = &tcbinfo[cpu].pcblisthead; 1066 lwkt_sendmsg(cpu_portfn(cpu), &nm->base.lmsg); 1067 } 1068 } 1069 #else 1070 tcp_drain_oncpu(&tcbinfo[0].pcblisthead); 1071 #endif 1072 } 1073 1074 /* 1075 * Notify a tcp user of an asynchronous error; 1076 * store error as soft error, but wake up user 1077 * (for now, won't do anything until can select for soft error). 1078 * 1079 * Do not wake up user since there currently is no mechanism for 1080 * reporting soft errors (yet - a kqueue filter may be added). 1081 */ 1082 static void 1083 tcp_notify(struct inpcb *inp, int error) 1084 { 1085 struct tcpcb *tp = intotcpcb(inp); 1086 1087 /* 1088 * Ignore some errors if we are hooked up. 1089 * If connection hasn't completed, has retransmitted several times, 1090 * and receives a second error, give up now. This is better 1091 * than waiting a long time to establish a connection that 1092 * can never complete. 1093 */ 1094 if (tp->t_state == TCPS_ESTABLISHED && 1095 (error == EHOSTUNREACH || error == ENETUNREACH || 1096 error == EHOSTDOWN)) { 1097 return; 1098 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1099 tp->t_softerror) 1100 tcp_drop(tp, error); 1101 else 1102 tp->t_softerror = error; 1103 #if 0 1104 wakeup(&so->so_timeo); 1105 sorwakeup(so); 1106 sowwakeup(so); 1107 #endif 1108 } 1109 1110 static int 1111 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1112 { 1113 int error, i, n; 1114 struct inpcb *marker; 1115 struct inpcb *inp; 1116 globaldata_t gd; 1117 int origcpu, ccpu; 1118 1119 error = 0; 1120 n = 0; 1121 1122 /* 1123 * The process of preparing the TCB list is too time-consuming and 1124 * resource-intensive to repeat twice on every request. 1125 */ 1126 if (req->oldptr == NULL) { 1127 for (ccpu = 0; ccpu < ncpus; ++ccpu) { 1128 gd = globaldata_find(ccpu); 1129 n += tcbinfo[gd->gd_cpuid].ipi_count; 1130 } 1131 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1132 return (0); 1133 } 1134 1135 if (req->newptr != NULL) 1136 return (EPERM); 1137 1138 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1139 marker->inp_flags |= INP_PLACEMARKER; 1140 1141 /* 1142 * OK, now we're committed to doing something. Run the inpcb list 1143 * for each cpu in the system and construct the output. Use a 1144 * list placemarker to deal with list changes occuring during 1145 * copyout blockages (but otherwise depend on being on the correct 1146 * cpu to avoid races). 1147 */ 1148 origcpu = mycpu->gd_cpuid; 1149 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) { 1150 globaldata_t rgd; 1151 caddr_t inp_ppcb; 1152 struct xtcpcb xt; 1153 int cpu_id; 1154 1155 cpu_id = (origcpu + ccpu) % ncpus; 1156 if ((smp_active_mask & CPUMASK(cpu_id)) == 0) 1157 continue; 1158 rgd = globaldata_find(cpu_id); 1159 lwkt_setcpu_self(rgd); 1160 1161 n = tcbinfo[cpu_id].ipi_count; 1162 1163 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list); 1164 i = 0; 1165 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1166 /* 1167 * process a snapshot of pcbs, ignoring placemarkers 1168 * and using our own to allow SYSCTL_OUT to block. 1169 */ 1170 LIST_REMOVE(marker, inp_list); 1171 LIST_INSERT_AFTER(inp, marker, inp_list); 1172 1173 if (inp->inp_flags & INP_PLACEMARKER) 1174 continue; 1175 if (prison_xinpcb(req->td, inp)) 1176 continue; 1177 1178 xt.xt_len = sizeof xt; 1179 bcopy(inp, &xt.xt_inp, sizeof *inp); 1180 inp_ppcb = inp->inp_ppcb; 1181 if (inp_ppcb != NULL) 1182 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1183 else 1184 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1185 if (inp->inp_socket) 1186 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1187 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1188 break; 1189 ++i; 1190 } 1191 LIST_REMOVE(marker, inp_list); 1192 if (error == 0 && i < n) { 1193 bzero(&xt, sizeof xt); 1194 xt.xt_len = sizeof xt; 1195 while (i < n) { 1196 error = SYSCTL_OUT(req, &xt, sizeof xt); 1197 if (error) 1198 break; 1199 ++i; 1200 } 1201 } 1202 } 1203 1204 /* 1205 * Make sure we are on the same cpu we were on originally, since 1206 * higher level callers expect this. Also don't pollute caches with 1207 * migrated userland data by (eventually) returning to userland 1208 * on a different cpu. 1209 */ 1210 lwkt_setcpu_self(globaldata_find(origcpu)); 1211 kfree(marker, M_TEMP); 1212 return (error); 1213 } 1214 1215 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1216 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1217 1218 static int 1219 tcp_getcred(SYSCTL_HANDLER_ARGS) 1220 { 1221 struct sockaddr_in addrs[2]; 1222 struct inpcb *inp; 1223 int cpu; 1224 int error; 1225 1226 error = priv_check(req->td, PRIV_ROOT); 1227 if (error != 0) 1228 return (error); 1229 error = SYSCTL_IN(req, addrs, sizeof addrs); 1230 if (error != 0) 1231 return (error); 1232 crit_enter(); 1233 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1234 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1235 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1236 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1237 if (inp == NULL || inp->inp_socket == NULL) { 1238 error = ENOENT; 1239 goto out; 1240 } 1241 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1242 out: 1243 crit_exit(); 1244 return (error); 1245 } 1246 1247 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1248 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1249 1250 #ifdef INET6 1251 static int 1252 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1253 { 1254 struct sockaddr_in6 addrs[2]; 1255 struct inpcb *inp; 1256 int error; 1257 boolean_t mapped = FALSE; 1258 1259 error = priv_check(req->td, PRIV_ROOT); 1260 if (error != 0) 1261 return (error); 1262 error = SYSCTL_IN(req, addrs, sizeof addrs); 1263 if (error != 0) 1264 return (error); 1265 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1266 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1267 mapped = TRUE; 1268 else 1269 return (EINVAL); 1270 } 1271 crit_enter(); 1272 if (mapped) { 1273 inp = in_pcblookup_hash(&tcbinfo[0], 1274 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1275 addrs[1].sin6_port, 1276 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1277 addrs[0].sin6_port, 1278 0, NULL); 1279 } else { 1280 inp = in6_pcblookup_hash(&tcbinfo[0], 1281 &addrs[1].sin6_addr, addrs[1].sin6_port, 1282 &addrs[0].sin6_addr, addrs[0].sin6_port, 1283 0, NULL); 1284 } 1285 if (inp == NULL || inp->inp_socket == NULL) { 1286 error = ENOENT; 1287 goto out; 1288 } 1289 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1290 out: 1291 crit_exit(); 1292 return (error); 1293 } 1294 1295 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1296 0, 0, 1297 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1298 #endif 1299 1300 struct netmsg_tcp_notify { 1301 struct netmsg_base base; 1302 void (*nm_notify)(struct inpcb *, int); 1303 struct in_addr nm_faddr; 1304 int nm_arg; 1305 }; 1306 1307 static void 1308 tcp_notifyall_oncpu(netmsg_t msg) 1309 { 1310 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1311 int nextcpu; 1312 1313 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr, 1314 nm->nm_arg, nm->nm_notify); 1315 1316 nextcpu = mycpuid + 1; 1317 if (nextcpu < ncpus2) 1318 lwkt_forwardmsg(cpu_portfn(nextcpu), &nm->base.lmsg); 1319 else 1320 lwkt_replymsg(&nm->base.lmsg, 0); 1321 } 1322 1323 void 1324 tcp_ctlinput(netmsg_t msg) 1325 { 1326 int cmd = msg->ctlinput.nm_cmd; 1327 struct sockaddr *sa = msg->ctlinput.nm_arg; 1328 struct ip *ip = msg->ctlinput.nm_extra; 1329 struct tcphdr *th; 1330 struct in_addr faddr; 1331 struct inpcb *inp; 1332 struct tcpcb *tp; 1333 void (*notify)(struct inpcb *, int) = tcp_notify; 1334 tcp_seq icmpseq; 1335 int arg, cpu; 1336 1337 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1338 goto done; 1339 } 1340 1341 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1342 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1343 goto done; 1344 1345 arg = inetctlerrmap[cmd]; 1346 if (cmd == PRC_QUENCH) { 1347 notify = tcp_quench; 1348 } else if (icmp_may_rst && 1349 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1350 cmd == PRC_UNREACH_PORT || 1351 cmd == PRC_TIMXCEED_INTRANS) && 1352 ip != NULL) { 1353 notify = tcp_drop_syn_sent; 1354 } else if (cmd == PRC_MSGSIZE) { 1355 struct icmp *icmp = (struct icmp *) 1356 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1357 1358 arg = ntohs(icmp->icmp_nextmtu); 1359 notify = tcp_mtudisc; 1360 } else if (PRC_IS_REDIRECT(cmd)) { 1361 ip = NULL; 1362 notify = in_rtchange; 1363 } else if (cmd == PRC_HOSTDEAD) { 1364 ip = NULL; 1365 } 1366 1367 if (ip != NULL) { 1368 crit_enter(); 1369 th = (struct tcphdr *)((caddr_t)ip + 1370 (IP_VHL_HL(ip->ip_vhl) << 2)); 1371 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1372 ip->ip_src.s_addr, th->th_sport); 1373 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1374 ip->ip_src, th->th_sport, 0, NULL); 1375 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1376 icmpseq = htonl(th->th_seq); 1377 tp = intotcpcb(inp); 1378 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1379 SEQ_LT(icmpseq, tp->snd_max)) 1380 (*notify)(inp, arg); 1381 } else { 1382 struct in_conninfo inc; 1383 1384 inc.inc_fport = th->th_dport; 1385 inc.inc_lport = th->th_sport; 1386 inc.inc_faddr = faddr; 1387 inc.inc_laddr = ip->ip_src; 1388 #ifdef INET6 1389 inc.inc_isipv6 = 0; 1390 #endif 1391 syncache_unreach(&inc, th); 1392 } 1393 crit_exit(); 1394 } else { 1395 struct netmsg_tcp_notify *nm; 1396 1397 KKASSERT(&curthread->td_msgport == cpu_portfn(0)); 1398 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1399 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1400 0, tcp_notifyall_oncpu); 1401 nm->nm_faddr = faddr; 1402 nm->nm_arg = arg; 1403 nm->nm_notify = notify; 1404 1405 lwkt_sendmsg(cpu_portfn(0), &nm->base.lmsg); 1406 } 1407 done: 1408 lwkt_replymsg(&msg->lmsg, 0); 1409 } 1410 1411 #ifdef INET6 1412 1413 void 1414 tcp6_ctlinput(netmsg_t msg) 1415 { 1416 int cmd = msg->ctlinput.nm_cmd; 1417 struct sockaddr *sa = msg->ctlinput.nm_arg; 1418 void *d = msg->ctlinput.nm_extra; 1419 struct tcphdr th; 1420 void (*notify) (struct inpcb *, int) = tcp_notify; 1421 struct ip6_hdr *ip6; 1422 struct mbuf *m; 1423 struct ip6ctlparam *ip6cp = NULL; 1424 const struct sockaddr_in6 *sa6_src = NULL; 1425 int off; 1426 struct tcp_portonly { 1427 u_int16_t th_sport; 1428 u_int16_t th_dport; 1429 } *thp; 1430 int arg; 1431 1432 if (sa->sa_family != AF_INET6 || 1433 sa->sa_len != sizeof(struct sockaddr_in6)) { 1434 goto out; 1435 } 1436 1437 arg = 0; 1438 if (cmd == PRC_QUENCH) 1439 notify = tcp_quench; 1440 else if (cmd == PRC_MSGSIZE) { 1441 struct ip6ctlparam *ip6cp = d; 1442 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1443 1444 arg = ntohl(icmp6->icmp6_mtu); 1445 notify = tcp_mtudisc; 1446 } else if (!PRC_IS_REDIRECT(cmd) && 1447 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1448 goto out; 1449 } 1450 1451 /* if the parameter is from icmp6, decode it. */ 1452 if (d != NULL) { 1453 ip6cp = (struct ip6ctlparam *)d; 1454 m = ip6cp->ip6c_m; 1455 ip6 = ip6cp->ip6c_ip6; 1456 off = ip6cp->ip6c_off; 1457 sa6_src = ip6cp->ip6c_src; 1458 } else { 1459 m = NULL; 1460 ip6 = NULL; 1461 off = 0; /* fool gcc */ 1462 sa6_src = &sa6_any; 1463 } 1464 1465 if (ip6 != NULL) { 1466 struct in_conninfo inc; 1467 /* 1468 * XXX: We assume that when IPV6 is non NULL, 1469 * M and OFF are valid. 1470 */ 1471 1472 /* check if we can safely examine src and dst ports */ 1473 if (m->m_pkthdr.len < off + sizeof *thp) 1474 goto out; 1475 1476 bzero(&th, sizeof th); 1477 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1478 1479 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1480 (struct sockaddr *)ip6cp->ip6c_src, 1481 th.th_sport, cmd, arg, notify); 1482 1483 inc.inc_fport = th.th_dport; 1484 inc.inc_lport = th.th_sport; 1485 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1486 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1487 inc.inc_isipv6 = 1; 1488 syncache_unreach(&inc, &th); 1489 } else { 1490 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1491 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1492 } 1493 out: 1494 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1495 } 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