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_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/socket.h> 89 #include <sys/socketvar.h> 90 #include <sys/protosw.h> 91 #include <sys/random.h> 92 #include <sys/in_cksum.h> 93 #include <sys/ktr.h> 94 95 #include <vm/vm_zone.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_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 #ifdef INET6 130 #include <netinet6/ipsec6.h> 131 #endif 132 #endif 133 134 #ifdef FAST_IPSEC 135 #include <netproto/ipsec/ipsec.h> 136 #ifdef INET6 137 #include <netproto/ipsec/ipsec6.h> 138 #endif 139 #define IPSEC 140 #endif 141 142 #include <sys/md5.h> 143 #include <sys/msgport2.h> 144 #include <machine/smp.h> 145 146 #include <net/netmsg2.h> 147 148 #if !defined(KTR_TCP) 149 #define KTR_TCP KTR_ALL 150 #endif 151 KTR_INFO_MASTER(tcp); 152 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 153 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 154 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 155 #define logtcp(name) KTR_LOG(tcp_ ## name) 156 157 struct inpcbinfo tcbinfo[MAXCPU]; 158 struct tcpcbackqhead tcpcbackq[MAXCPU]; 159 160 int tcp_mpsafe_proto = 0; 161 TUNABLE_INT("net.inet.tcp.mpsafe_proto", &tcp_mpsafe_proto); 162 163 static int tcp_mpsafe_thread = 0; 164 TUNABLE_INT("net.inet.tcp.mpsafe_thread", &tcp_mpsafe_thread); 165 SYSCTL_INT(_net_inet_tcp, OID_AUTO, mpsafe_thread, CTLFLAG_RW, 166 &tcp_mpsafe_thread, 0, 167 "0:BGL, 1:Adaptive BGL, 2:No BGL(experimental)"); 168 169 int tcp_mssdflt = TCP_MSS; 170 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 171 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 172 173 #ifdef INET6 174 int tcp_v6mssdflt = TCP6_MSS; 175 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 176 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 177 #endif 178 179 #if 0 180 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 181 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 182 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 183 #endif 184 185 int tcp_do_rfc1323 = 1; 186 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 187 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 188 189 int tcp_do_rfc1644 = 0; 190 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW, 191 &tcp_do_rfc1644, 0, "Enable rfc1644 (TTCP) extensions"); 192 193 static int tcp_tcbhashsize = 0; 194 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 195 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 196 197 static int do_tcpdrain = 1; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 199 "Enable tcp_drain routine for extra help when low on mbufs"); 200 201 /* XXX JH */ 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, 203 &tcbinfo[0].ipi_count, 0, "Number of active PCBs"); 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. Note that the default lower bound of 215 * 1024 exists only for debugging. A good production default would be 216 * something like 6100. 217 */ 218 static int tcp_inflight_enable = 0; 219 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 220 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 221 222 static int tcp_inflight_debug = 0; 223 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 224 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 225 226 static int tcp_inflight_min = 6144; 227 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 228 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 229 230 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 232 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 233 234 static int tcp_inflight_stab = 20; 235 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 236 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 2 packets)"); 237 238 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 239 static struct malloc_pipe tcptemp_mpipe; 240 241 static void tcp_willblock(int); 242 static void tcp_cleartaocache (void); 243 static void tcp_notify (struct inpcb *, int); 244 245 struct tcp_stats tcpstats_percpu[MAXCPU]; 246 #ifdef SMP 247 static int 248 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 249 { 250 int cpu, error = 0; 251 252 for (cpu = 0; cpu < ncpus; ++cpu) { 253 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 254 sizeof(struct tcp_stats)))) 255 break; 256 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 257 sizeof(struct tcp_stats)))) 258 break; 259 } 260 261 return (error); 262 } 263 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 264 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 265 #else 266 SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW, 267 &tcpstat, tcp_stats, "TCP statistics"); 268 #endif 269 270 /* 271 * Target size of TCP PCB hash tables. Must be a power of two. 272 * 273 * Note that this can be overridden by the kernel environment 274 * variable net.inet.tcp.tcbhashsize 275 */ 276 #ifndef TCBHASHSIZE 277 #define TCBHASHSIZE 512 278 #endif 279 280 /* 281 * This is the actual shape of what we allocate using the zone 282 * allocator. Doing it this way allows us to protect both structures 283 * using the same generation count, and also eliminates the overhead 284 * of allocating tcpcbs separately. By hiding the structure here, 285 * we avoid changing most of the rest of the code (although it needs 286 * to be changed, eventually, for greater efficiency). 287 */ 288 #define ALIGNMENT 32 289 #define ALIGNM1 (ALIGNMENT - 1) 290 struct inp_tp { 291 union { 292 struct inpcb inp; 293 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 294 } inp_tp_u; 295 struct tcpcb tcb; 296 struct callout inp_tp_rexmt, inp_tp_persist, inp_tp_keep, inp_tp_2msl; 297 struct callout inp_tp_delack; 298 }; 299 #undef ALIGNMENT 300 #undef ALIGNM1 301 302 /* 303 * Tcp initialization 304 */ 305 void 306 tcp_init(void) 307 { 308 struct inpcbporthead *porthashbase; 309 u_long porthashmask; 310 struct vm_zone *ipi_zone; 311 int hashsize = TCBHASHSIZE; 312 int cpu; 313 314 /* 315 * note: tcptemp is used for keepalives, and it is ok for an 316 * allocation to fail so do not specify MPF_INT. 317 */ 318 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 319 25, -1, 0, NULL); 320 321 tcp_ccgen = 1; 322 tcp_cleartaocache(); 323 324 tcp_delacktime = TCPTV_DELACK; 325 tcp_keepinit = TCPTV_KEEP_INIT; 326 tcp_keepidle = TCPTV_KEEP_IDLE; 327 tcp_keepintvl = TCPTV_KEEPINTVL; 328 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 329 tcp_msl = TCPTV_MSL; 330 tcp_rexmit_min = TCPTV_MIN; 331 tcp_rexmit_slop = TCPTV_CPU_VAR; 332 333 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 334 if (!powerof2(hashsize)) { 335 kprintf("WARNING: TCB hash size not a power of 2\n"); 336 hashsize = 512; /* safe default */ 337 } 338 tcp_tcbhashsize = hashsize; 339 porthashbase = hashinit(hashsize, M_PCB, &porthashmask); 340 ipi_zone = zinit("tcpcb", sizeof(struct inp_tp), maxsockets, 341 ZONE_INTERRUPT, 0); 342 343 for (cpu = 0; cpu < ncpus2; cpu++) { 344 in_pcbinfo_init(&tcbinfo[cpu]); 345 tcbinfo[cpu].cpu = cpu; 346 tcbinfo[cpu].hashbase = hashinit(hashsize, M_PCB, 347 &tcbinfo[cpu].hashmask); 348 tcbinfo[cpu].porthashbase = porthashbase; 349 tcbinfo[cpu].porthashmask = porthashmask; 350 tcbinfo[cpu].wildcardhashbase = hashinit(hashsize, M_PCB, 351 &tcbinfo[cpu].wildcardhashmask); 352 tcbinfo[cpu].ipi_zone = ipi_zone; 353 TAILQ_INIT(&tcpcbackq[cpu]); 354 } 355 356 tcp_reass_maxseg = nmbclusters / 16; 357 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 358 359 #ifdef INET6 360 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 361 #else 362 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 363 #endif 364 if (max_protohdr < TCP_MINPROTOHDR) 365 max_protohdr = TCP_MINPROTOHDR; 366 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 367 panic("tcp_init"); 368 #undef TCP_MINPROTOHDR 369 370 /* 371 * Initialize TCP statistics counters for each CPU. 372 */ 373 #ifdef SMP 374 for (cpu = 0; cpu < ncpus; ++cpu) { 375 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 376 } 377 #else 378 bzero(&tcpstat, sizeof(struct tcp_stats)); 379 #endif 380 381 syncache_init(); 382 tcp_thread_init(); 383 } 384 385 void 386 tcpmsg_service_loop(void *dummy) 387 { 388 struct netmsg *msg; 389 int mplocked; 390 391 /* 392 * Thread was started with TDF_MPSAFE 393 */ 394 mplocked = 0; 395 396 while ((msg = lwkt_waitport(&curthread->td_msgport, 0))) { 397 do { 398 logtcp(rxmsg); 399 mplocked = netmsg_service(msg, tcp_mpsafe_thread, 400 mplocked); 401 } while ((msg = lwkt_getport(&curthread->td_msgport)) != NULL); 402 403 logtcp(delayed); 404 tcp_willblock(mplocked); 405 logtcp(wait); 406 } 407 } 408 409 static void 410 tcp_willblock(int mplocked) 411 { 412 struct tcpcb *tp; 413 int cpu = mycpu->gd_cpuid; 414 int unlock = 0; 415 416 if (!mplocked && !tcp_mpsafe_proto) { 417 if (TAILQ_EMPTY(&tcpcbackq[cpu])) 418 return; 419 420 get_mplock(); 421 mplocked = 1; 422 unlock = 1; 423 } 424 425 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 426 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 427 tp->t_flags &= ~TF_ONOUTPUTQ; 428 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 429 tcp_output(tp); 430 } 431 432 if (unlock) 433 rel_mplock(); 434 } 435 436 437 /* 438 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 439 * tcp_template used to store this data in mbufs, but we now recopy it out 440 * of the tcpcb each time to conserve mbufs. 441 */ 442 void 443 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr) 444 { 445 struct inpcb *inp = tp->t_inpcb; 446 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 447 448 #ifdef INET6 449 if (inp->inp_vflag & INP_IPV6) { 450 struct ip6_hdr *ip6; 451 452 ip6 = (struct ip6_hdr *)ip_ptr; 453 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 454 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 455 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 456 (IPV6_VERSION & IPV6_VERSION_MASK); 457 ip6->ip6_nxt = IPPROTO_TCP; 458 ip6->ip6_plen = sizeof(struct tcphdr); 459 ip6->ip6_src = inp->in6p_laddr; 460 ip6->ip6_dst = inp->in6p_faddr; 461 tcp_hdr->th_sum = 0; 462 } else 463 #endif 464 { 465 struct ip *ip = (struct ip *) ip_ptr; 466 467 ip->ip_vhl = IP_VHL_BORING; 468 ip->ip_tos = 0; 469 ip->ip_len = 0; 470 ip->ip_id = 0; 471 ip->ip_off = 0; 472 ip->ip_ttl = 0; 473 ip->ip_sum = 0; 474 ip->ip_p = IPPROTO_TCP; 475 ip->ip_src = inp->inp_laddr; 476 ip->ip_dst = inp->inp_faddr; 477 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 478 ip->ip_dst.s_addr, 479 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 480 } 481 482 tcp_hdr->th_sport = inp->inp_lport; 483 tcp_hdr->th_dport = inp->inp_fport; 484 tcp_hdr->th_seq = 0; 485 tcp_hdr->th_ack = 0; 486 tcp_hdr->th_x2 = 0; 487 tcp_hdr->th_off = 5; 488 tcp_hdr->th_flags = 0; 489 tcp_hdr->th_win = 0; 490 tcp_hdr->th_urp = 0; 491 } 492 493 /* 494 * Create template to be used to send tcp packets on a connection. 495 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 496 * use for this function is in keepalives, which use tcp_respond. 497 */ 498 struct tcptemp * 499 tcp_maketemplate(struct tcpcb *tp) 500 { 501 struct tcptemp *tmp; 502 503 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 504 return (NULL); 505 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t); 506 return (tmp); 507 } 508 509 void 510 tcp_freetemplate(struct tcptemp *tmp) 511 { 512 mpipe_free(&tcptemp_mpipe, tmp); 513 } 514 515 /* 516 * Send a single message to the TCP at address specified by 517 * the given TCP/IP header. If m == NULL, then we make a copy 518 * of the tcpiphdr at ti and send directly to the addressed host. 519 * This is used to force keep alive messages out using the TCP 520 * template for a connection. If flags are given then we send 521 * a message back to the TCP which originated the * segment ti, 522 * and discard the mbuf containing it and any other attached mbufs. 523 * 524 * In any case the ack and sequence number of the transmitted 525 * segment are as specified by the parameters. 526 * 527 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 528 */ 529 void 530 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 531 tcp_seq ack, tcp_seq seq, int flags) 532 { 533 int tlen; 534 int win = 0; 535 struct route *ro = NULL; 536 struct route sro; 537 struct ip *ip = ipgen; 538 struct tcphdr *nth; 539 int ipflags = 0; 540 struct route_in6 *ro6 = NULL; 541 struct route_in6 sro6; 542 struct ip6_hdr *ip6 = ipgen; 543 boolean_t use_tmpro = TRUE; 544 #ifdef INET6 545 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 546 #else 547 const boolean_t isipv6 = FALSE; 548 #endif 549 550 if (tp != NULL) { 551 if (!(flags & TH_RST)) { 552 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 553 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 554 win = (long)TCP_MAXWIN << tp->rcv_scale; 555 } 556 /* 557 * Don't use the route cache of a listen socket, 558 * it is not MPSAFE; use temporary route cache. 559 */ 560 if (tp->t_state != TCPS_LISTEN) { 561 if (isipv6) 562 ro6 = &tp->t_inpcb->in6p_route; 563 else 564 ro = &tp->t_inpcb->inp_route; 565 use_tmpro = FALSE; 566 } 567 } 568 if (use_tmpro) { 569 if (isipv6) { 570 ro6 = &sro6; 571 bzero(ro6, sizeof *ro6); 572 } else { 573 ro = &sro; 574 bzero(ro, sizeof *ro); 575 } 576 } 577 if (m == NULL) { 578 m = m_gethdr(MB_DONTWAIT, MT_HEADER); 579 if (m == NULL) 580 return; 581 tlen = 0; 582 m->m_data += max_linkhdr; 583 if (isipv6) { 584 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 585 ip6 = mtod(m, struct ip6_hdr *); 586 nth = (struct tcphdr *)(ip6 + 1); 587 } else { 588 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 589 ip = mtod(m, struct ip *); 590 nth = (struct tcphdr *)(ip + 1); 591 } 592 bcopy(th, nth, sizeof(struct tcphdr)); 593 flags = TH_ACK; 594 } else { 595 m_freem(m->m_next); 596 m->m_next = NULL; 597 m->m_data = (caddr_t)ipgen; 598 /* m_len is set later */ 599 tlen = 0; 600 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 601 if (isipv6) { 602 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 603 nth = (struct tcphdr *)(ip6 + 1); 604 } else { 605 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 606 nth = (struct tcphdr *)(ip + 1); 607 } 608 if (th != nth) { 609 /* 610 * this is usually a case when an extension header 611 * exists between the IPv6 header and the 612 * TCP header. 613 */ 614 nth->th_sport = th->th_sport; 615 nth->th_dport = th->th_dport; 616 } 617 xchg(nth->th_dport, nth->th_sport, n_short); 618 #undef xchg 619 } 620 if (isipv6) { 621 ip6->ip6_flow = 0; 622 ip6->ip6_vfc = IPV6_VERSION; 623 ip6->ip6_nxt = IPPROTO_TCP; 624 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 625 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 626 } else { 627 tlen += sizeof(struct tcpiphdr); 628 ip->ip_len = tlen; 629 ip->ip_ttl = ip_defttl; 630 } 631 m->m_len = tlen; 632 m->m_pkthdr.len = tlen; 633 m->m_pkthdr.rcvif = (struct ifnet *) NULL; 634 nth->th_seq = htonl(seq); 635 nth->th_ack = htonl(ack); 636 nth->th_x2 = 0; 637 nth->th_off = sizeof(struct tcphdr) >> 2; 638 nth->th_flags = flags; 639 if (tp != NULL) 640 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 641 else 642 nth->th_win = htons((u_short)win); 643 nth->th_urp = 0; 644 if (isipv6) { 645 nth->th_sum = 0; 646 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 647 sizeof(struct ip6_hdr), 648 tlen - sizeof(struct ip6_hdr)); 649 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 650 (ro6 && ro6->ro_rt) ? 651 ro6->ro_rt->rt_ifp : NULL); 652 } else { 653 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 654 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 655 m->m_pkthdr.csum_flags = CSUM_TCP; 656 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 657 } 658 #ifdef TCPDEBUG 659 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 660 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 661 #endif 662 if (isipv6) { 663 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 664 tp ? tp->t_inpcb : NULL); 665 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 666 RTFREE(ro6->ro_rt); 667 ro6->ro_rt = NULL; 668 } 669 } else { 670 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 671 if ((ro == &sro) && (ro->ro_rt != NULL)) { 672 RTFREE(ro->ro_rt); 673 ro->ro_rt = NULL; 674 } 675 } 676 } 677 678 /* 679 * Create a new TCP control block, making an 680 * empty reassembly queue and hooking it to the argument 681 * protocol control block. The `inp' parameter must have 682 * come from the zone allocator set up in tcp_init(). 683 */ 684 struct tcpcb * 685 tcp_newtcpcb(struct inpcb *inp) 686 { 687 struct inp_tp *it; 688 struct tcpcb *tp; 689 #ifdef INET6 690 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 691 #else 692 const boolean_t isipv6 = FALSE; 693 #endif 694 695 it = (struct inp_tp *)inp; 696 tp = &it->tcb; 697 bzero(tp, sizeof(struct tcpcb)); 698 LIST_INIT(&tp->t_segq); 699 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 700 701 /* Set up our timeouts. */ 702 callout_init(tp->tt_rexmt = &it->inp_tp_rexmt); 703 callout_init(tp->tt_persist = &it->inp_tp_persist); 704 callout_init(tp->tt_keep = &it->inp_tp_keep); 705 callout_init(tp->tt_2msl = &it->inp_tp_2msl); 706 callout_init(tp->tt_delack = &it->inp_tp_delack); 707 708 if (tcp_do_rfc1323) 709 tp->t_flags = (TF_REQ_SCALE | TF_REQ_TSTMP); 710 if (tcp_do_rfc1644) 711 tp->t_flags |= TF_REQ_CC; 712 tp->t_inpcb = inp; /* XXX */ 713 tp->t_state = TCPS_CLOSED; 714 /* 715 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 716 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 717 * reasonable initial retransmit time. 718 */ 719 tp->t_srtt = TCPTV_SRTTBASE; 720 tp->t_rttvar = 721 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 722 tp->t_rttmin = tcp_rexmit_min; 723 tp->t_rxtcur = TCPTV_RTOBASE; 724 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 725 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 726 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 727 tp->t_rcvtime = ticks; 728 /* 729 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 730 * because the socket may be bound to an IPv6 wildcard address, 731 * which may match an IPv4-mapped IPv6 address. 732 */ 733 inp->inp_ip_ttl = ip_defttl; 734 inp->inp_ppcb = tp; 735 tcp_sack_tcpcb_init(tp); 736 return (tp); /* XXX */ 737 } 738 739 /* 740 * Drop a TCP connection, reporting the specified error. 741 * If connection is synchronized, then send a RST to peer. 742 */ 743 struct tcpcb * 744 tcp_drop(struct tcpcb *tp, int error) 745 { 746 struct socket *so = tp->t_inpcb->inp_socket; 747 748 if (TCPS_HAVERCVDSYN(tp->t_state)) { 749 tp->t_state = TCPS_CLOSED; 750 tcp_output(tp); 751 tcpstat.tcps_drops++; 752 } else 753 tcpstat.tcps_conndrops++; 754 if (error == ETIMEDOUT && tp->t_softerror) 755 error = tp->t_softerror; 756 so->so_error = error; 757 return (tcp_close(tp)); 758 } 759 760 #ifdef SMP 761 762 struct netmsg_remwildcard { 763 struct netmsg nm_netmsg; 764 struct inpcb *nm_inp; 765 struct inpcbinfo *nm_pcbinfo; 766 #if defined(INET6) 767 int nm_isinet6; 768 #else 769 int nm_unused01; 770 #endif 771 }; 772 773 /* 774 * Wildcard inpcb's on SMP boxes must be removed from all cpus before the 775 * inp can be detached. We do this by cycling through the cpus, ending up 776 * on the cpu controlling the inp last and then doing the disconnect. 777 */ 778 static void 779 in_pcbremwildcardhash_handler(struct netmsg *msg0) 780 { 781 struct netmsg_remwildcard *msg = (struct netmsg_remwildcard *)msg0; 782 int cpu; 783 784 cpu = msg->nm_pcbinfo->cpu; 785 786 if (cpu == msg->nm_inp->inp_pcbinfo->cpu) { 787 /* note: detach removes any wildcard hash entry */ 788 #ifdef INET6 789 if (msg->nm_isinet6) 790 in6_pcbdetach(msg->nm_inp); 791 else 792 #endif 793 in_pcbdetach(msg->nm_inp); 794 lwkt_replymsg(&msg->nm_netmsg.nm_lmsg, 0); 795 } else { 796 in_pcbremwildcardhash_oncpu(msg->nm_inp, msg->nm_pcbinfo); 797 cpu = (cpu + 1) % ncpus2; 798 msg->nm_pcbinfo = &tcbinfo[cpu]; 799 lwkt_forwardmsg(tcp_cport(cpu), &msg->nm_netmsg.nm_lmsg); 800 } 801 } 802 803 #endif 804 805 /* 806 * Close a TCP control block: 807 * discard all space held by the tcp 808 * discard internet protocol block 809 * wake up any sleepers 810 */ 811 struct tcpcb * 812 tcp_close(struct tcpcb *tp) 813 { 814 struct tseg_qent *q; 815 struct inpcb *inp = tp->t_inpcb; 816 struct socket *so = inp->inp_socket; 817 struct rtentry *rt; 818 boolean_t dosavessthresh; 819 #ifdef SMP 820 int cpu; 821 #endif 822 #ifdef INET6 823 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 824 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 825 #else 826 const boolean_t isipv6 = FALSE; 827 #endif 828 829 /* 830 * The tp is not instantly destroyed in the wildcard case. Setting 831 * the state to TCPS_TERMINATING will prevent the TCP stack from 832 * messing with it, though it should be noted that this change may 833 * not take effect on other cpus until we have chained the wildcard 834 * hash removal. 835 * 836 * XXX we currently depend on the BGL to synchronize the tp->t_state 837 * update and prevent other tcp protocol threads from accepting new 838 * connections on the listen socket we might be trying to close down. 839 */ 840 KKASSERT(tp->t_state != TCPS_TERMINATING); 841 tp->t_state = TCPS_TERMINATING; 842 843 /* 844 * Make sure that all of our timers are stopped before we 845 * delete the PCB. 846 */ 847 callout_stop(tp->tt_rexmt); 848 callout_stop(tp->tt_persist); 849 callout_stop(tp->tt_keep); 850 callout_stop(tp->tt_2msl); 851 callout_stop(tp->tt_delack); 852 853 if (tp->t_flags & TF_ONOUTPUTQ) { 854 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 855 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 856 tp->t_flags &= ~TF_ONOUTPUTQ; 857 } 858 859 /* 860 * If we got enough samples through the srtt filter, 861 * save the rtt and rttvar in the routing entry. 862 * 'Enough' is arbitrarily defined as the 16 samples. 863 * 16 samples is enough for the srtt filter to converge 864 * to within 5% of the correct value; fewer samples and 865 * we could save a very bogus rtt. 866 * 867 * Don't update the default route's characteristics and don't 868 * update anything that the user "locked". 869 */ 870 if (tp->t_rttupdated >= 16) { 871 u_long i = 0; 872 873 if (isipv6) { 874 struct sockaddr_in6 *sin6; 875 876 if ((rt = inp->in6p_route.ro_rt) == NULL) 877 goto no_valid_rt; 878 sin6 = (struct sockaddr_in6 *)rt_key(rt); 879 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 880 goto no_valid_rt; 881 } else 882 if ((rt = inp->inp_route.ro_rt) == NULL || 883 ((struct sockaddr_in *)rt_key(rt))-> 884 sin_addr.s_addr == INADDR_ANY) 885 goto no_valid_rt; 886 887 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 888 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 889 if (rt->rt_rmx.rmx_rtt && i) 890 /* 891 * filter this update to half the old & half 892 * the new values, converting scale. 893 * See route.h and tcp_var.h for a 894 * description of the scaling constants. 895 */ 896 rt->rt_rmx.rmx_rtt = 897 (rt->rt_rmx.rmx_rtt + i) / 2; 898 else 899 rt->rt_rmx.rmx_rtt = i; 900 tcpstat.tcps_cachedrtt++; 901 } 902 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 903 i = tp->t_rttvar * 904 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 905 if (rt->rt_rmx.rmx_rttvar && i) 906 rt->rt_rmx.rmx_rttvar = 907 (rt->rt_rmx.rmx_rttvar + i) / 2; 908 else 909 rt->rt_rmx.rmx_rttvar = i; 910 tcpstat.tcps_cachedrttvar++; 911 } 912 /* 913 * The old comment here said: 914 * update the pipelimit (ssthresh) if it has been updated 915 * already or if a pipesize was specified & the threshhold 916 * got below half the pipesize. I.e., wait for bad news 917 * before we start updating, then update on both good 918 * and bad news. 919 * 920 * But we want to save the ssthresh even if no pipesize is 921 * specified explicitly in the route, because such 922 * connections still have an implicit pipesize specified 923 * by the global tcp_sendspace. In the absence of a reliable 924 * way to calculate the pipesize, it will have to do. 925 */ 926 i = tp->snd_ssthresh; 927 if (rt->rt_rmx.rmx_sendpipe != 0) 928 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 929 else 930 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 931 if (dosavessthresh || 932 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 933 (rt->rt_rmx.rmx_ssthresh != 0))) { 934 /* 935 * convert the limit from user data bytes to 936 * packets then to packet data bytes. 937 */ 938 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 939 if (i < 2) 940 i = 2; 941 i *= tp->t_maxseg + 942 (isipv6 ? 943 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 944 sizeof(struct tcpiphdr)); 945 if (rt->rt_rmx.rmx_ssthresh) 946 rt->rt_rmx.rmx_ssthresh = 947 (rt->rt_rmx.rmx_ssthresh + i) / 2; 948 else 949 rt->rt_rmx.rmx_ssthresh = i; 950 tcpstat.tcps_cachedssthresh++; 951 } 952 } 953 954 no_valid_rt: 955 /* free the reassembly queue, if any */ 956 while((q = LIST_FIRST(&tp->t_segq)) != NULL) { 957 LIST_REMOVE(q, tqe_q); 958 m_freem(q->tqe_m); 959 FREE(q, M_TSEGQ); 960 tcp_reass_qsize--; 961 } 962 /* throw away SACK blocks in scoreboard*/ 963 if (TCP_DO_SACK(tp)) 964 tcp_sack_cleanup(&tp->scb); 965 966 inp->inp_ppcb = NULL; 967 soisdisconnected(so); 968 /* 969 * Discard the inp. In the SMP case a wildcard inp's hash (created 970 * by a listen socket or an INADDR_ANY udp socket) is replicated 971 * for each protocol thread and must be removed in the context of 972 * that thread. This is accomplished by chaining the message 973 * through the cpus. 974 * 975 * If the inp is not wildcarded we simply detach, which will remove 976 * the any hashes still present for this inp. 977 */ 978 #ifdef SMP 979 if (inp->inp_flags & INP_WILDCARD_MP) { 980 struct netmsg_remwildcard *msg; 981 982 cpu = (inp->inp_pcbinfo->cpu + 1) % ncpus2; 983 msg = kmalloc(sizeof(struct netmsg_remwildcard), 984 M_LWKTMSG, M_INTWAIT); 985 netmsg_init(&msg->nm_netmsg, &netisr_afree_rport, 0, 986 in_pcbremwildcardhash_handler); 987 #ifdef INET6 988 msg->nm_isinet6 = isafinet6; 989 #endif 990 msg->nm_inp = inp; 991 msg->nm_pcbinfo = &tcbinfo[cpu]; 992 lwkt_sendmsg(tcp_cport(cpu), &msg->nm_netmsg.nm_lmsg); 993 } else 994 #endif 995 { 996 /* note: detach removes any wildcard hash entry */ 997 #ifdef INET6 998 if (isafinet6) 999 in6_pcbdetach(inp); 1000 else 1001 #endif 1002 in_pcbdetach(inp); 1003 } 1004 tcpstat.tcps_closed++; 1005 return (NULL); 1006 } 1007 1008 static __inline void 1009 tcp_drain_oncpu(struct inpcbhead *head) 1010 { 1011 struct inpcb *inpb; 1012 struct tcpcb *tcpb; 1013 struct tseg_qent *te; 1014 1015 LIST_FOREACH(inpb, head, inp_list) { 1016 if (inpb->inp_flags & INP_PLACEMARKER) 1017 continue; 1018 if ((tcpb = intotcpcb(inpb))) { 1019 while ((te = LIST_FIRST(&tcpb->t_segq)) != NULL) { 1020 LIST_REMOVE(te, tqe_q); 1021 m_freem(te->tqe_m); 1022 FREE(te, M_TSEGQ); 1023 tcp_reass_qsize--; 1024 } 1025 } 1026 } 1027 } 1028 1029 #ifdef SMP 1030 struct netmsg_tcp_drain { 1031 struct netmsg nm_netmsg; 1032 struct inpcbhead *nm_head; 1033 }; 1034 1035 static void 1036 tcp_drain_handler(netmsg_t netmsg) 1037 { 1038 struct netmsg_tcp_drain *nm = (void *)netmsg; 1039 1040 tcp_drain_oncpu(nm->nm_head); 1041 lwkt_replymsg(&nm->nm_netmsg.nm_lmsg, 0); 1042 } 1043 #endif 1044 1045 void 1046 tcp_drain(void) 1047 { 1048 #ifdef SMP 1049 int cpu; 1050 #endif 1051 1052 if (!do_tcpdrain) 1053 return; 1054 1055 /* 1056 * Walk the tcpbs, if existing, and flush the reassembly queue, 1057 * if there is one... 1058 * XXX: The "Net/3" implementation doesn't imply that the TCP 1059 * reassembly queue should be flushed, but in a situation 1060 * where we're really low on mbufs, this is potentially 1061 * useful. 1062 */ 1063 #ifdef SMP 1064 for (cpu = 0; cpu < ncpus2; cpu++) { 1065 struct netmsg_tcp_drain *msg; 1066 1067 if (cpu == mycpu->gd_cpuid) { 1068 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1069 } else { 1070 msg = kmalloc(sizeof(struct netmsg_tcp_drain), 1071 M_LWKTMSG, M_NOWAIT); 1072 if (msg == NULL) 1073 continue; 1074 netmsg_init(&msg->nm_netmsg, &netisr_afree_rport, 0, 1075 tcp_drain_handler); 1076 msg->nm_head = &tcbinfo[cpu].pcblisthead; 1077 lwkt_sendmsg(tcp_cport(cpu), &msg->nm_netmsg.nm_lmsg); 1078 } 1079 } 1080 #else 1081 tcp_drain_oncpu(&tcbinfo[0].pcblisthead); 1082 #endif 1083 } 1084 1085 /* 1086 * Notify a tcp user of an asynchronous error; 1087 * store error as soft error, but wake up user 1088 * (for now, won't do anything until can select for soft error). 1089 * 1090 * Do not wake up user since there currently is no mechanism for 1091 * reporting soft errors (yet - a kqueue filter may be added). 1092 */ 1093 static void 1094 tcp_notify(struct inpcb *inp, int error) 1095 { 1096 struct tcpcb *tp = intotcpcb(inp); 1097 1098 /* 1099 * Ignore some errors if we are hooked up. 1100 * If connection hasn't completed, has retransmitted several times, 1101 * and receives a second error, give up now. This is better 1102 * than waiting a long time to establish a connection that 1103 * can never complete. 1104 */ 1105 if (tp->t_state == TCPS_ESTABLISHED && 1106 (error == EHOSTUNREACH || error == ENETUNREACH || 1107 error == EHOSTDOWN)) { 1108 return; 1109 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1110 tp->t_softerror) 1111 tcp_drop(tp, error); 1112 else 1113 tp->t_softerror = error; 1114 #if 0 1115 wakeup(&so->so_timeo); 1116 sorwakeup(so); 1117 sowwakeup(so); 1118 #endif 1119 } 1120 1121 static int 1122 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1123 { 1124 int error, i, n; 1125 struct inpcb *marker; 1126 struct inpcb *inp; 1127 inp_gen_t gencnt; 1128 globaldata_t gd; 1129 int origcpu, ccpu; 1130 1131 error = 0; 1132 n = 0; 1133 1134 /* 1135 * The process of preparing the TCB list is too time-consuming and 1136 * resource-intensive to repeat twice on every request. 1137 */ 1138 if (req->oldptr == NULL) { 1139 for (ccpu = 0; ccpu < ncpus; ++ccpu) { 1140 gd = globaldata_find(ccpu); 1141 n += tcbinfo[gd->gd_cpuid].ipi_count; 1142 } 1143 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1144 return (0); 1145 } 1146 1147 if (req->newptr != NULL) 1148 return (EPERM); 1149 1150 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1151 marker->inp_flags |= INP_PLACEMARKER; 1152 1153 /* 1154 * OK, now we're committed to doing something. Run the inpcb list 1155 * for each cpu in the system and construct the output. Use a 1156 * list placemarker to deal with list changes occuring during 1157 * copyout blockages (but otherwise depend on being on the correct 1158 * cpu to avoid races). 1159 */ 1160 origcpu = mycpu->gd_cpuid; 1161 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) { 1162 globaldata_t rgd; 1163 caddr_t inp_ppcb; 1164 struct xtcpcb xt; 1165 int cpu_id; 1166 1167 cpu_id = (origcpu + ccpu) % ncpus; 1168 if ((smp_active_mask & (1 << cpu_id)) == 0) 1169 continue; 1170 rgd = globaldata_find(cpu_id); 1171 lwkt_setcpu_self(rgd); 1172 1173 gencnt = tcbinfo[cpu_id].ipi_gencnt; 1174 n = tcbinfo[cpu_id].ipi_count; 1175 1176 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list); 1177 i = 0; 1178 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1179 /* 1180 * process a snapshot of pcbs, ignoring placemarkers 1181 * and using our own to allow SYSCTL_OUT to block. 1182 */ 1183 LIST_REMOVE(marker, inp_list); 1184 LIST_INSERT_AFTER(inp, marker, inp_list); 1185 1186 if (inp->inp_flags & INP_PLACEMARKER) 1187 continue; 1188 if (inp->inp_gencnt > gencnt) 1189 continue; 1190 if (prison_xinpcb(req->td, inp)) 1191 continue; 1192 1193 xt.xt_len = sizeof xt; 1194 bcopy(inp, &xt.xt_inp, sizeof *inp); 1195 inp_ppcb = inp->inp_ppcb; 1196 if (inp_ppcb != NULL) 1197 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1198 else 1199 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1200 if (inp->inp_socket) 1201 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1202 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1203 break; 1204 ++i; 1205 } 1206 LIST_REMOVE(marker, inp_list); 1207 if (error == 0 && i < n) { 1208 bzero(&xt, sizeof xt); 1209 xt.xt_len = sizeof xt; 1210 while (i < n) { 1211 error = SYSCTL_OUT(req, &xt, sizeof xt); 1212 if (error) 1213 break; 1214 ++i; 1215 } 1216 } 1217 } 1218 1219 /* 1220 * Make sure we are on the same cpu we were on originally, since 1221 * higher level callers expect this. Also don't pollute caches with 1222 * migrated userland data by (eventually) returning to userland 1223 * on a different cpu. 1224 */ 1225 lwkt_setcpu_self(globaldata_find(origcpu)); 1226 kfree(marker, M_TEMP); 1227 return (error); 1228 } 1229 1230 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1231 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1232 1233 static int 1234 tcp_getcred(SYSCTL_HANDLER_ARGS) 1235 { 1236 struct sockaddr_in addrs[2]; 1237 struct inpcb *inp; 1238 int cpu; 1239 int error; 1240 1241 error = suser(req->td); 1242 if (error != 0) 1243 return (error); 1244 error = SYSCTL_IN(req, addrs, sizeof addrs); 1245 if (error != 0) 1246 return (error); 1247 crit_enter(); 1248 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1249 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1250 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1251 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1252 if (inp == NULL || inp->inp_socket == NULL) { 1253 error = ENOENT; 1254 goto out; 1255 } 1256 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1257 out: 1258 crit_exit(); 1259 return (error); 1260 } 1261 1262 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1263 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1264 1265 #ifdef INET6 1266 static int 1267 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1268 { 1269 struct sockaddr_in6 addrs[2]; 1270 struct inpcb *inp; 1271 int error; 1272 boolean_t mapped = FALSE; 1273 1274 error = suser(req->td); 1275 if (error != 0) 1276 return (error); 1277 error = SYSCTL_IN(req, addrs, sizeof addrs); 1278 if (error != 0) 1279 return (error); 1280 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1281 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1282 mapped = TRUE; 1283 else 1284 return (EINVAL); 1285 } 1286 crit_enter(); 1287 if (mapped) { 1288 inp = in_pcblookup_hash(&tcbinfo[0], 1289 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1290 addrs[1].sin6_port, 1291 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1292 addrs[0].sin6_port, 1293 0, NULL); 1294 } else { 1295 inp = in6_pcblookup_hash(&tcbinfo[0], 1296 &addrs[1].sin6_addr, addrs[1].sin6_port, 1297 &addrs[0].sin6_addr, addrs[0].sin6_port, 1298 0, NULL); 1299 } 1300 if (inp == NULL || inp->inp_socket == NULL) { 1301 error = ENOENT; 1302 goto out; 1303 } 1304 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1305 out: 1306 crit_exit(); 1307 return (error); 1308 } 1309 1310 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1311 0, 0, 1312 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1313 #endif 1314 1315 struct netmsg_tcp_notify { 1316 struct netmsg nm_nmsg; 1317 void (*nm_notify)(struct inpcb *, int); 1318 struct in_addr nm_faddr; 1319 int nm_arg; 1320 }; 1321 1322 static void 1323 tcp_notifyall_oncpu(struct netmsg *netmsg) 1324 { 1325 struct netmsg_tcp_notify *nmsg = (struct netmsg_tcp_notify *)netmsg; 1326 int nextcpu; 1327 1328 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nmsg->nm_faddr, 1329 nmsg->nm_arg, nmsg->nm_notify); 1330 1331 nextcpu = mycpuid + 1; 1332 if (nextcpu < ncpus2) 1333 lwkt_forwardmsg(tcp_cport(nextcpu), &netmsg->nm_lmsg); 1334 else 1335 lwkt_replymsg(&netmsg->nm_lmsg, 0); 1336 } 1337 1338 void 1339 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1340 { 1341 struct ip *ip = vip; 1342 struct tcphdr *th; 1343 struct in_addr faddr; 1344 struct inpcb *inp; 1345 struct tcpcb *tp; 1346 void (*notify)(struct inpcb *, int) = tcp_notify; 1347 tcp_seq icmpseq; 1348 int arg, cpu; 1349 1350 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1351 return; 1352 } 1353 1354 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1355 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1356 return; 1357 1358 arg = inetctlerrmap[cmd]; 1359 if (cmd == PRC_QUENCH) { 1360 notify = tcp_quench; 1361 } else if (icmp_may_rst && 1362 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1363 cmd == PRC_UNREACH_PORT || 1364 cmd == PRC_TIMXCEED_INTRANS) && 1365 ip != NULL) { 1366 notify = tcp_drop_syn_sent; 1367 } else if (cmd == PRC_MSGSIZE) { 1368 struct icmp *icmp = (struct icmp *) 1369 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1370 1371 arg = ntohs(icmp->icmp_nextmtu); 1372 notify = tcp_mtudisc; 1373 } else if (PRC_IS_REDIRECT(cmd)) { 1374 ip = NULL; 1375 notify = in_rtchange; 1376 } else if (cmd == PRC_HOSTDEAD) { 1377 ip = NULL; 1378 } 1379 1380 if (ip != NULL) { 1381 crit_enter(); 1382 th = (struct tcphdr *)((caddr_t)ip + 1383 (IP_VHL_HL(ip->ip_vhl) << 2)); 1384 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1385 ip->ip_src.s_addr, th->th_sport); 1386 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1387 ip->ip_src, th->th_sport, 0, NULL); 1388 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1389 icmpseq = htonl(th->th_seq); 1390 tp = intotcpcb(inp); 1391 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1392 SEQ_LT(icmpseq, tp->snd_max)) 1393 (*notify)(inp, arg); 1394 } else { 1395 struct in_conninfo inc; 1396 1397 inc.inc_fport = th->th_dport; 1398 inc.inc_lport = th->th_sport; 1399 inc.inc_faddr = faddr; 1400 inc.inc_laddr = ip->ip_src; 1401 #ifdef INET6 1402 inc.inc_isipv6 = 0; 1403 #endif 1404 syncache_unreach(&inc, th); 1405 } 1406 crit_exit(); 1407 } else { 1408 struct netmsg_tcp_notify nmsg; 1409 1410 KKASSERT(&curthread->td_msgport == cpu_portfn(0)); 1411 netmsg_init(&nmsg.nm_nmsg, &curthread->td_msgport, 0, 1412 tcp_notifyall_oncpu); 1413 nmsg.nm_faddr = faddr; 1414 nmsg.nm_arg = arg; 1415 nmsg.nm_notify = notify; 1416 1417 lwkt_domsg(tcp_cport(0), &nmsg.nm_nmsg.nm_lmsg, 0); 1418 } 1419 } 1420 1421 #ifdef INET6 1422 void 1423 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1424 { 1425 struct tcphdr th; 1426 void (*notify) (struct inpcb *, int) = tcp_notify; 1427 struct ip6_hdr *ip6; 1428 struct mbuf *m; 1429 struct ip6ctlparam *ip6cp = NULL; 1430 const struct sockaddr_in6 *sa6_src = NULL; 1431 int off; 1432 struct tcp_portonly { 1433 u_int16_t th_sport; 1434 u_int16_t th_dport; 1435 } *thp; 1436 int arg; 1437 1438 if (sa->sa_family != AF_INET6 || 1439 sa->sa_len != sizeof(struct sockaddr_in6)) 1440 return; 1441 1442 arg = 0; 1443 if (cmd == PRC_QUENCH) 1444 notify = tcp_quench; 1445 else if (cmd == PRC_MSGSIZE) { 1446 struct ip6ctlparam *ip6cp = d; 1447 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1448 1449 arg = ntohl(icmp6->icmp6_mtu); 1450 notify = tcp_mtudisc; 1451 } else if (!PRC_IS_REDIRECT(cmd) && 1452 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1453 return; 1454 } 1455 1456 /* if the parameter is from icmp6, decode it. */ 1457 if (d != NULL) { 1458 ip6cp = (struct ip6ctlparam *)d; 1459 m = ip6cp->ip6c_m; 1460 ip6 = ip6cp->ip6c_ip6; 1461 off = ip6cp->ip6c_off; 1462 sa6_src = ip6cp->ip6c_src; 1463 } else { 1464 m = NULL; 1465 ip6 = NULL; 1466 off = 0; /* fool gcc */ 1467 sa6_src = &sa6_any; 1468 } 1469 1470 if (ip6 != NULL) { 1471 struct in_conninfo inc; 1472 /* 1473 * XXX: We assume that when IPV6 is non NULL, 1474 * M and OFF are valid. 1475 */ 1476 1477 /* check if we can safely examine src and dst ports */ 1478 if (m->m_pkthdr.len < off + sizeof *thp) 1479 return; 1480 1481 bzero(&th, sizeof th); 1482 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1483 1484 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1485 (struct sockaddr *)ip6cp->ip6c_src, 1486 th.th_sport, cmd, arg, notify); 1487 1488 inc.inc_fport = th.th_dport; 1489 inc.inc_lport = th.th_sport; 1490 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1491 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1492 inc.inc_isipv6 = 1; 1493 syncache_unreach(&inc, &th); 1494 } else 1495 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1496 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1497 } 1498 #endif 1499 1500 /* 1501 * Following is where TCP initial sequence number generation occurs. 1502 * 1503 * There are two places where we must use initial sequence numbers: 1504 * 1. In SYN-ACK packets. 1505 * 2. In SYN packets. 1506 * 1507 * All ISNs for SYN-ACK packets are generated by the syncache. See 1508 * tcp_syncache.c for details. 1509 * 1510 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1511 * depends on this property. In addition, these ISNs should be 1512 * unguessable so as to prevent connection hijacking. To satisfy 1513 * the requirements of this situation, the algorithm outlined in 1514 * RFC 1948 is used to generate sequence numbers. 1515 * 1516 * Implementation details: 1517 * 1518 * Time is based off the system timer, and is corrected so that it 1519 * increases by one megabyte per second. This allows for proper 1520 * recycling on high speed LANs while still leaving over an hour 1521 * before rollover. 1522 * 1523 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1524 * between seeding of isn_secret. This is normally set to zero, 1525 * as reseeding should not be necessary. 1526 * 1527 */ 1528 1529 #define ISN_BYTES_PER_SECOND 1048576 1530 1531 u_char isn_secret[32]; 1532 int isn_last_reseed; 1533 MD5_CTX isn_ctx; 1534 1535 tcp_seq 1536 tcp_new_isn(struct tcpcb *tp) 1537 { 1538 u_int32_t md5_buffer[4]; 1539 tcp_seq new_isn; 1540 1541 /* Seed if this is the first use, reseed if requested. */ 1542 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1543 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1544 < (u_int)ticks))) { 1545 read_random_unlimited(&isn_secret, sizeof isn_secret); 1546 isn_last_reseed = ticks; 1547 } 1548 1549 /* Compute the md5 hash and return the ISN. */ 1550 MD5Init(&isn_ctx); 1551 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1552 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1553 #ifdef INET6 1554 if (tp->t_inpcb->inp_vflag & INP_IPV6) { 1555 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1556 sizeof(struct in6_addr)); 1557 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1558 sizeof(struct in6_addr)); 1559 } else 1560 #endif 1561 { 1562 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1563 sizeof(struct in_addr)); 1564 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1565 sizeof(struct in_addr)); 1566 } 1567 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1568 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1569 new_isn = (tcp_seq) md5_buffer[0]; 1570 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1571 return (new_isn); 1572 } 1573 1574 /* 1575 * When a source quench is received, close congestion window 1576 * to one segment. We will gradually open it again as we proceed. 1577 */ 1578 void 1579 tcp_quench(struct inpcb *inp, int error) 1580 { 1581 struct tcpcb *tp = intotcpcb(inp); 1582 1583 if (tp != NULL) { 1584 tp->snd_cwnd = tp->t_maxseg; 1585 tp->snd_wacked = 0; 1586 } 1587 } 1588 1589 /* 1590 * When a specific ICMP unreachable message is received and the 1591 * connection state is SYN-SENT, drop the connection. This behavior 1592 * is controlled by the icmp_may_rst sysctl. 1593 */ 1594 void 1595 tcp_drop_syn_sent(struct inpcb *inp, int error) 1596 { 1597 struct tcpcb *tp = intotcpcb(inp); 1598 1599 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT)) 1600 tcp_drop(tp, error); 1601 } 1602 1603 /* 1604 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1605 * based on the new value in the route. Also nudge TCP to send something, 1606 * since we know the packet we just sent was dropped. 1607 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1608 */ 1609 void 1610 tcp_mtudisc(struct inpcb *inp, int mtu) 1611 { 1612 struct tcpcb *tp = intotcpcb(inp); 1613 struct rtentry *rt; 1614 struct socket *so = inp->inp_socket; 1615 int maxopd, mss; 1616 #ifdef INET6 1617 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0); 1618 #else 1619 const boolean_t isipv6 = FALSE; 1620 #endif 1621 1622 if (tp == NULL) 1623 return; 1624 1625 /* 1626 * If no MTU is provided in the ICMP message, use the 1627 * next lower likely value, as specified in RFC 1191. 1628 */ 1629 if (mtu == 0) { 1630 int oldmtu; 1631 1632 oldmtu = tp->t_maxopd + 1633 (isipv6 ? 1634 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1635 sizeof(struct tcpiphdr)); 1636 mtu = ip_next_mtu(oldmtu, 0); 1637 } 1638 1639 if (isipv6) 1640 rt = tcp_rtlookup6(&inp->inp_inc); 1641 else 1642 rt = tcp_rtlookup(&inp->inp_inc); 1643 if (rt != NULL) { 1644 struct rmxp_tao *taop = rmx_taop(rt->rt_rmx); 1645 1646 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1647 mtu = rt->rt_rmx.rmx_mtu; 1648 1649 maxopd = mtu - 1650 (isipv6 ? 1651 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1652 sizeof(struct tcpiphdr)); 1653 1654 /* 1655 * XXX - The following conditional probably violates the TCP 1656 * spec. The problem is that, since we don't know the 1657 * other end's MSS, we are supposed to use a conservative 1658 * default. But, if we do that, then MTU discovery will 1659 * never actually take place, because the conservative 1660 * default is much less than the MTUs typically seen 1661 * on the Internet today. For the moment, we'll sweep 1662 * this under the carpet. 1663 * 1664 * The conservative default might not actually be a problem 1665 * if the only case this occurs is when sending an initial 1666 * SYN with options and data to a host we've never talked 1667 * to before. Then, they will reply with an MSS value which 1668 * will get recorded and the new parameters should get 1669 * recomputed. For Further Study. 1670 */ 1671 if (taop->tao_mssopt != 0 && taop->tao_mssopt < maxopd) 1672 maxopd = taop->tao_mssopt; 1673 } else 1674 maxopd = mtu - 1675 (isipv6 ? 1676 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1677 sizeof(struct tcpiphdr)); 1678 1679 if (tp->t_maxopd <= maxopd) 1680 return; 1681 tp->t_maxopd = maxopd; 1682 1683 mss = maxopd; 1684 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1685 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1686 mss -= TCPOLEN_TSTAMP_APPA; 1687 1688 if ((tp->t_flags & (TF_REQ_CC | TF_RCVD_CC | TF_NOOPT)) == 1689 (TF_REQ_CC | TF_RCVD_CC)) 1690 mss -= TCPOLEN_CC_APPA; 1691 1692 /* round down to multiple of MCLBYTES */ 1693 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1694 if (mss > MCLBYTES) 1695 mss &= ~(MCLBYTES - 1); 1696 #else 1697 if (mss > MCLBYTES) 1698 mss = (mss / MCLBYTES) * MCLBYTES; 1699 #endif 1700 1701 if (so->so_snd.ssb_hiwat < mss) 1702 mss = so->so_snd.ssb_hiwat; 1703 1704 tp->t_maxseg = mss; 1705 tp->t_rtttime = 0; 1706 tp->snd_nxt = tp->snd_una; 1707 tcp_output(tp); 1708 tcpstat.tcps_mturesent++; 1709 } 1710 1711 /* 1712 * Look-up the routing entry to the peer of this inpcb. If no route 1713 * is found and it cannot be allocated the return NULL. This routine 1714 * is called by TCP routines that access the rmx structure and by tcp_mss 1715 * to get the interface MTU. 1716 */ 1717 struct rtentry * 1718 tcp_rtlookup(struct in_conninfo *inc) 1719 { 1720 struct route *ro = &inc->inc_route; 1721 1722 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1723 /* No route yet, so try to acquire one */ 1724 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1725 /* 1726 * unused portions of the structure MUST be zero'd 1727 * out because rtalloc() treats it as opaque data 1728 */ 1729 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1730 ro->ro_dst.sa_family = AF_INET; 1731 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1732 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1733 inc->inc_faddr; 1734 rtalloc(ro); 1735 } 1736 } 1737 return (ro->ro_rt); 1738 } 1739 1740 #ifdef INET6 1741 struct rtentry * 1742 tcp_rtlookup6(struct in_conninfo *inc) 1743 { 1744 struct route_in6 *ro6 = &inc->inc6_route; 1745 1746 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1747 /* No route yet, so try to acquire one */ 1748 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1749 /* 1750 * unused portions of the structure MUST be zero'd 1751 * out because rtalloc() treats it as opaque data 1752 */ 1753 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1754 ro6->ro_dst.sin6_family = AF_INET6; 1755 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1756 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1757 rtalloc((struct route *)ro6); 1758 } 1759 } 1760 return (ro6->ro_rt); 1761 } 1762 #endif 1763 1764 #ifdef IPSEC 1765 /* compute ESP/AH header size for TCP, including outer IP header. */ 1766 size_t 1767 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1768 { 1769 struct inpcb *inp; 1770 struct mbuf *m; 1771 size_t hdrsiz; 1772 struct ip *ip; 1773 struct tcphdr *th; 1774 1775 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1776 return (0); 1777 MGETHDR(m, MB_DONTWAIT, MT_DATA); 1778 if (!m) 1779 return (0); 1780 1781 #ifdef INET6 1782 if (inp->inp_vflag & INP_IPV6) { 1783 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1784 1785 th = (struct tcphdr *)(ip6 + 1); 1786 m->m_pkthdr.len = m->m_len = 1787 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1788 tcp_fillheaders(tp, ip6, th); 1789 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1790 } else 1791 #endif 1792 { 1793 ip = mtod(m, struct ip *); 1794 th = (struct tcphdr *)(ip + 1); 1795 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1796 tcp_fillheaders(tp, ip, th); 1797 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1798 } 1799 1800 m_free(m); 1801 return (hdrsiz); 1802 } 1803 #endif 1804 1805 /* 1806 * Return a pointer to the cached information about the remote host. 1807 * The cached information is stored in the protocol specific part of 1808 * the route metrics. 1809 */ 1810 struct rmxp_tao * 1811 tcp_gettaocache(struct in_conninfo *inc) 1812 { 1813 struct rtentry *rt; 1814 1815 #ifdef INET6 1816 if (inc->inc_isipv6) 1817 rt = tcp_rtlookup6(inc); 1818 else 1819 #endif 1820 rt = tcp_rtlookup(inc); 1821 1822 /* Make sure this is a host route and is up. */ 1823 if (rt == NULL || 1824 (rt->rt_flags & (RTF_UP | RTF_HOST)) != (RTF_UP | RTF_HOST)) 1825 return (NULL); 1826 1827 return (rmx_taop(rt->rt_rmx)); 1828 } 1829 1830 /* 1831 * Clear all the TAO cache entries, called from tcp_init. 1832 * 1833 * XXX 1834 * This routine is just an empty one, because we assume that the routing 1835 * routing tables are initialized at the same time when TCP, so there is 1836 * nothing in the cache left over. 1837 */ 1838 static void 1839 tcp_cleartaocache(void) 1840 { 1841 } 1842 1843 /* 1844 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1845 * 1846 * This code attempts to calculate the bandwidth-delay product as a 1847 * means of determining the optimal window size to maximize bandwidth, 1848 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1849 * routers. This code also does a fairly good job keeping RTTs in check 1850 * across slow links like modems. We implement an algorithm which is very 1851 * similar (but not meant to be) TCP/Vegas. The code operates on the 1852 * transmitter side of a TCP connection and so only effects the transmit 1853 * side of the connection. 1854 * 1855 * BACKGROUND: TCP makes no provision for the management of buffer space 1856 * at the end points or at the intermediate routers and switches. A TCP 1857 * stream, whether using NewReno or not, will eventually buffer as 1858 * many packets as it is able and the only reason this typically works is 1859 * due to the fairly small default buffers made available for a connection 1860 * (typicaly 16K or 32K). As machines use larger windows and/or window 1861 * scaling it is now fairly easy for even a single TCP connection to blow-out 1862 * all available buffer space not only on the local interface, but on 1863 * intermediate routers and switches as well. NewReno makes a misguided 1864 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1865 * then backing off, then steadily increasing the window again until another 1866 * failure occurs, ad-infinitum. This results in terrible oscillation that 1867 * is only made worse as network loads increase and the idea of intentionally 1868 * blowing out network buffers is, frankly, a terrible way to manage network 1869 * resources. 1870 * 1871 * It is far better to limit the transmit window prior to the failure 1872 * condition being achieved. There are two general ways to do this: First 1873 * you can 'scan' through different transmit window sizes and locate the 1874 * point where the RTT stops increasing, indicating that you have filled the 1875 * pipe, then scan backwards until you note that RTT stops decreasing, then 1876 * repeat ad-infinitum. This method works in principle but has severe 1877 * implementation issues due to RTT variances, timer granularity, and 1878 * instability in the algorithm which can lead to many false positives and 1879 * create oscillations as well as interact badly with other TCP streams 1880 * implementing the same algorithm. 1881 * 1882 * The second method is to limit the window to the bandwidth delay product 1883 * of the link. This is the method we implement. RTT variances and our 1884 * own manipulation of the congestion window, bwnd, can potentially 1885 * destabilize the algorithm. For this reason we have to stabilize the 1886 * elements used to calculate the window. We do this by using the minimum 1887 * observed RTT, the long term average of the observed bandwidth, and 1888 * by adding two segments worth of slop. It isn't perfect but it is able 1889 * to react to changing conditions and gives us a very stable basis on 1890 * which to extend the algorithm. 1891 */ 1892 void 1893 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1894 { 1895 u_long bw; 1896 u_long bwnd; 1897 int save_ticks; 1898 int delta_ticks; 1899 1900 /* 1901 * If inflight_enable is disabled in the middle of a tcp connection, 1902 * make sure snd_bwnd is effectively disabled. 1903 */ 1904 if (!tcp_inflight_enable) { 1905 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1906 tp->snd_bandwidth = 0; 1907 return; 1908 } 1909 1910 /* 1911 * Validate the delta time. If a connection is new or has been idle 1912 * a long time we have to reset the bandwidth calculator. 1913 */ 1914 save_ticks = ticks; 1915 delta_ticks = save_ticks - tp->t_bw_rtttime; 1916 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1917 tp->t_bw_rtttime = ticks; 1918 tp->t_bw_rtseq = ack_seq; 1919 if (tp->snd_bandwidth == 0) 1920 tp->snd_bandwidth = tcp_inflight_min; 1921 return; 1922 } 1923 if (delta_ticks == 0) 1924 return; 1925 1926 /* 1927 * Sanity check, plus ignore pure window update acks. 1928 */ 1929 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1930 return; 1931 1932 /* 1933 * Figure out the bandwidth. Due to the tick granularity this 1934 * is a very rough number and it MUST be averaged over a fairly 1935 * long period of time. XXX we need to take into account a link 1936 * that is not using all available bandwidth, but for now our 1937 * slop will ramp us up if this case occurs and the bandwidth later 1938 * increases. 1939 */ 1940 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 1941 tp->t_bw_rtttime = save_ticks; 1942 tp->t_bw_rtseq = ack_seq; 1943 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1944 1945 tp->snd_bandwidth = bw; 1946 1947 /* 1948 * Calculate the semi-static bandwidth delay product, plus two maximal 1949 * segments. The additional slop puts us squarely in the sweet 1950 * spot and also handles the bandwidth run-up case. Without the 1951 * slop we could be locking ourselves into a lower bandwidth. 1952 * 1953 * Situations Handled: 1954 * (1) Prevents over-queueing of packets on LANs, especially on 1955 * high speed LANs, allowing larger TCP buffers to be 1956 * specified, and also does a good job preventing 1957 * over-queueing of packets over choke points like modems 1958 * (at least for the transmit side). 1959 * 1960 * (2) Is able to handle changing network loads (bandwidth 1961 * drops so bwnd drops, bandwidth increases so bwnd 1962 * increases). 1963 * 1964 * (3) Theoretically should stabilize in the face of multiple 1965 * connections implementing the same algorithm (this may need 1966 * a little work). 1967 * 1968 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1969 * be adjusted with a sysctl but typically only needs to be on 1970 * very slow connections. A value no smaller then 5 should 1971 * be used, but only reduce this default if you have no other 1972 * choice. 1973 */ 1974 1975 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1976 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 1977 tcp_inflight_stab * (int)tp->t_maxseg / 10; 1978 #undef USERTT 1979 1980 if (tcp_inflight_debug > 0) { 1981 static int ltime; 1982 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1983 ltime = ticks; 1984 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1985 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd); 1986 } 1987 } 1988 if ((long)bwnd < tcp_inflight_min) 1989 bwnd = tcp_inflight_min; 1990 if (bwnd > tcp_inflight_max) 1991 bwnd = tcp_inflight_max; 1992 if ((long)bwnd < tp->t_maxseg * 2) 1993 bwnd = tp->t_maxseg * 2; 1994 tp->snd_bwnd = bwnd; 1995 } 1996