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. Neither the name of the University nor the names of its contributors 47 * may be used to endorse or promote products derived from this software 48 * without specific prior written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 * 62 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 63 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $ 64 */ 65 66 #include "opt_compat.h" 67 #include "opt_inet.h" 68 #include "opt_inet6.h" 69 #include "opt_ipsec.h" 70 #include "opt_tcpdebug.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/callout.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 #include <sys/malloc.h> 78 #include <sys/mpipe.h> 79 #include <sys/mbuf.h> 80 #ifdef INET6 81 #include <sys/domain.h> 82 #endif 83 #include <sys/proc.h> 84 #include <sys/priv.h> 85 #include <sys/socket.h> 86 #include <sys/socketops.h> 87 #include <sys/socketvar.h> 88 #include <sys/protosw.h> 89 #include <sys/random.h> 90 #include <sys/in_cksum.h> 91 #include <sys/ktr.h> 92 93 #include <net/route.h> 94 #include <net/if.h> 95 #include <net/netisr2.h> 96 97 #define _IP_VHL 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #include <netinet/ip.h> 101 #include <netinet/ip6.h> 102 #include <netinet/in_pcb.h> 103 #include <netinet6/in6_pcb.h> 104 #include <netinet/in_var.h> 105 #include <netinet/ip_var.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet/ip_icmp.h> 108 #ifdef INET6 109 #include <netinet/icmp6.h> 110 #endif 111 #include <netinet/tcp.h> 112 #include <netinet/tcp_fsm.h> 113 #include <netinet/tcp_seq.h> 114 #include <netinet/tcp_timer.h> 115 #include <netinet/tcp_timer2.h> 116 #include <netinet/tcp_var.h> 117 #include <netinet6/tcp6_var.h> 118 #include <netinet/tcpip.h> 119 #ifdef TCPDEBUG 120 #include <netinet/tcp_debug.h> 121 #endif 122 #include <netinet6/ip6protosw.h> 123 124 #ifdef IPSEC 125 #include <netinet6/ipsec.h> 126 #include <netproto/key/key.h> 127 #ifdef INET6 128 #include <netinet6/ipsec6.h> 129 #endif 130 #endif 131 132 #ifdef FAST_IPSEC 133 #include <netproto/ipsec/ipsec.h> 134 #ifdef INET6 135 #include <netproto/ipsec/ipsec6.h> 136 #endif 137 #define IPSEC 138 #endif 139 140 #include <sys/md5.h> 141 #include <machine/smp.h> 142 143 #include <sys/msgport2.h> 144 #include <sys/mplock2.h> 145 #include <net/netmsg2.h> 146 147 #if !defined(KTR_TCP) 148 #define KTR_TCP KTR_ALL 149 #endif 150 /* 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 */ 157 158 #define TCP_IW_MAXSEGS_DFLT 4 159 #define TCP_IW_CAPSEGS_DFLT 4 160 161 struct inpcbinfo tcbinfo[MAXCPU]; 162 struct tcpcbackqhead tcpcbackq[MAXCPU]; 163 164 int tcp_mssdflt = TCP_MSS; 165 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 166 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 167 168 #ifdef INET6 169 int tcp_v6mssdflt = TCP6_MSS; 170 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 171 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 172 #endif 173 174 /* 175 * Minimum MSS we accept and use. This prevents DoS attacks where 176 * we are forced to a ridiculous low MSS like 20 and send hundreds 177 * of packets instead of one. The effect scales with the available 178 * bandwidth and quickly saturates the CPU and network interface 179 * with packet generation and sending. Set to zero to disable MINMSS 180 * checking. This setting prevents us from sending too small packets. 181 */ 182 int tcp_minmss = TCP_MINMSS; 183 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 184 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 185 186 #if 0 187 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 188 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 189 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 190 #endif 191 192 int tcp_do_rfc1323 = 1; 193 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 194 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 195 196 static int tcp_tcbhashsize = 0; 197 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 198 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 199 200 static int do_tcpdrain = 1; 201 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 202 "Enable tcp_drain routine for extra help when low on mbufs"); 203 204 static int icmp_may_rst = 1; 205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 206 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 207 208 static int tcp_isn_reseed_interval = 0; 209 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 210 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 211 212 /* 213 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 214 * by default, but with generous values which should allow maximal 215 * bandwidth. In particular, the slop defaults to 50 (5 packets). 216 * 217 * The reason for doing this is that the limiter is the only mechanism we 218 * have which seems to do a really good job preventing receiver RX rings 219 * on network interfaces from getting blown out. Even though GigE/10GigE 220 * is supposed to flow control it looks like either it doesn't actually 221 * do it or Open Source drivers do not properly enable it. 222 * 223 * People using the limiter to reduce bottlenecks on slower WAN connections 224 * should set the slop to 20 (2 packets). 225 */ 226 static int tcp_inflight_enable = 1; 227 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 228 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 229 230 static int tcp_inflight_debug = 0; 231 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 232 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 233 234 /* 235 * NOTE: tcp_inflight_start is essentially the starting receive window 236 * for a connection. If set too low then fetches over tcp 237 * connections will take noticably longer to ramp-up over 238 * high-latency connections. 6144 is too low for a default, 239 * use something more reasonable. 240 */ 241 static int tcp_inflight_start = 33792; 242 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_start, CTLFLAG_RW, 243 &tcp_inflight_start, 0, "Start value for TCP inflight window"); 244 245 static int tcp_inflight_min = 6144; 246 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 247 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 248 249 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 250 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 251 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 252 253 static int tcp_inflight_stab = 50; 254 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 255 &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)"); 256 257 static int tcp_inflight_adjrtt = 2; 258 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW, 259 &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)"); 260 261 static int tcp_do_rfc3390 = 1; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW, 263 &tcp_do_rfc3390, 0, 264 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)"); 265 266 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 267 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW, 268 &tcp_iw_maxsegs, 0, "TCP IW segments max"); 269 270 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 271 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW, 272 &tcp_iw_capsegs, 0, "TCP IW segments"); 273 274 int tcp_low_rtobase = 1; 275 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW, 276 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)"); 277 278 static int tcp_do_ncr = 1; 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW, 280 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)"); 281 282 int tcp_ncr_rxtthresh_max = 16; 283 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW, 284 &tcp_ncr_rxtthresh_max, 0, 285 "Non-Congestion Robustness (RFC 4653), DupThresh upper limit"); 286 287 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 288 static struct malloc_pipe tcptemp_mpipe; 289 290 static void tcp_willblock(void); 291 static void tcp_notify (struct inpcb *, int); 292 293 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign; 294 295 static struct netmsg_base tcp_drain_netmsg[MAXCPU]; 296 static void tcp_drain_dispatch(netmsg_t nmsg); 297 298 static int 299 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 300 { 301 int cpu, error = 0; 302 303 for (cpu = 0; cpu < ncpus2; ++cpu) { 304 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 305 sizeof(struct tcp_stats)))) 306 break; 307 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 308 sizeof(struct tcp_stats)))) 309 break; 310 } 311 312 return (error); 313 } 314 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 315 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 316 317 /* 318 * Target size of TCP PCB hash tables. Must be a power of two. 319 * 320 * Note that this can be overridden by the kernel environment 321 * variable net.inet.tcp.tcbhashsize 322 */ 323 #ifndef TCBHASHSIZE 324 #define TCBHASHSIZE 512 325 #endif 326 327 /* 328 * This is the actual shape of what we allocate using the zone 329 * allocator. Doing it this way allows us to protect both structures 330 * using the same generation count, and also eliminates the overhead 331 * of allocating tcpcbs separately. By hiding the structure here, 332 * we avoid changing most of the rest of the code (although it needs 333 * to be changed, eventually, for greater efficiency). 334 */ 335 #define ALIGNMENT 32 336 #define ALIGNM1 (ALIGNMENT - 1) 337 struct inp_tp { 338 union { 339 struct inpcb inp; 340 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 341 } inp_tp_u; 342 struct tcpcb tcb; 343 struct tcp_callout inp_tp_rexmt; 344 struct tcp_callout inp_tp_persist; 345 struct tcp_callout inp_tp_keep; 346 struct tcp_callout inp_tp_2msl; 347 struct tcp_callout inp_tp_delack; 348 struct netmsg_tcp_timer inp_tp_timermsg; 349 struct netmsg_base inp_tp_sndmore; 350 }; 351 #undef ALIGNMENT 352 #undef ALIGNM1 353 354 /* 355 * Tcp initialization 356 */ 357 void 358 tcp_init(void) 359 { 360 struct inpcbportinfo *portinfo; 361 struct inpcbinfo *ticb; 362 int hashsize = TCBHASHSIZE; 363 int cpu; 364 365 /* 366 * note: tcptemp is used for keepalives, and it is ok for an 367 * allocation to fail so do not specify MPF_INT. 368 */ 369 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 370 25, -1, 0, NULL, NULL, NULL); 371 372 tcp_delacktime = TCPTV_DELACK; 373 tcp_keepinit = TCPTV_KEEP_INIT; 374 tcp_keepidle = TCPTV_KEEP_IDLE; 375 tcp_keepintvl = TCPTV_KEEPINTVL; 376 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 377 tcp_msl = TCPTV_MSL; 378 tcp_rexmit_min = TCPTV_MIN; 379 tcp_rexmit_slop = TCPTV_CPU_VAR; 380 381 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 382 if (!powerof2(hashsize)) { 383 kprintf("WARNING: TCB hash size not a power of 2\n"); 384 hashsize = 512; /* safe default */ 385 } 386 tcp_tcbhashsize = hashsize; 387 388 portinfo = kmalloc_cachealign(sizeof(*portinfo) * ncpus2, M_PCB, 389 M_WAITOK); 390 391 for (cpu = 0; cpu < ncpus2; cpu++) { 392 ticb = &tcbinfo[cpu]; 393 in_pcbinfo_init(ticb, cpu, FALSE); 394 ticb->hashbase = hashinit(hashsize, M_PCB, 395 &ticb->hashmask); 396 in_pcbportinfo_init(&portinfo[cpu], hashsize, TRUE, cpu); 397 ticb->portinfo = portinfo; 398 ticb->portinfo_mask = ncpus2_mask; 399 ticb->wildcardhashbase = hashinit(hashsize, M_PCB, 400 &ticb->wildcardhashmask); 401 ticb->localgrphashbase = hashinit(hashsize, M_PCB, 402 &ticb->localgrphashmask); 403 ticb->ipi_size = sizeof(struct inp_tp); 404 TAILQ_INIT(&tcpcbackq[cpu]); 405 } 406 407 tcp_reass_maxseg = nmbclusters / 16; 408 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 409 410 #ifdef INET6 411 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 412 #else 413 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 414 #endif 415 if (max_protohdr < TCP_MINPROTOHDR) 416 max_protohdr = TCP_MINPROTOHDR; 417 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 418 panic("tcp_init"); 419 #undef TCP_MINPROTOHDR 420 421 /* 422 * Initialize TCP statistics counters for each CPU. 423 */ 424 for (cpu = 0; cpu < ncpus2; ++cpu) 425 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 426 427 /* 428 * Initialize netmsgs for TCP drain 429 */ 430 for (cpu = 0; cpu < ncpus2; ++cpu) { 431 netmsg_init(&tcp_drain_netmsg[cpu], NULL, &netisr_adone_rport, 432 MSGF_PRIORITY, tcp_drain_dispatch); 433 } 434 435 syncache_init(); 436 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP); 437 } 438 439 static void 440 tcp_willblock(void) 441 { 442 struct tcpcb *tp; 443 int cpu = mycpu->gd_cpuid; 444 445 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 446 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 447 tp->t_flags &= ~TF_ONOUTPUTQ; 448 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 449 tcp_output(tp); 450 } 451 } 452 453 /* 454 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 455 * tcp_template used to store this data in mbufs, but we now recopy it out 456 * of the tcpcb each time to conserve mbufs. 457 */ 458 void 459 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso) 460 { 461 struct inpcb *inp = tp->t_inpcb; 462 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 463 464 #ifdef INET6 465 if (INP_ISIPV6(inp)) { 466 struct ip6_hdr *ip6; 467 468 ip6 = (struct ip6_hdr *)ip_ptr; 469 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 470 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 471 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 472 (IPV6_VERSION & IPV6_VERSION_MASK); 473 ip6->ip6_nxt = IPPROTO_TCP; 474 ip6->ip6_plen = sizeof(struct tcphdr); 475 ip6->ip6_src = inp->in6p_laddr; 476 ip6->ip6_dst = inp->in6p_faddr; 477 tcp_hdr->th_sum = 0; 478 } else 479 #endif 480 { 481 struct ip *ip = (struct ip *) ip_ptr; 482 u_int plen; 483 484 ip->ip_vhl = IP_VHL_BORING; 485 ip->ip_tos = 0; 486 ip->ip_len = 0; 487 ip->ip_id = 0; 488 ip->ip_off = 0; 489 ip->ip_ttl = 0; 490 ip->ip_sum = 0; 491 ip->ip_p = IPPROTO_TCP; 492 ip->ip_src = inp->inp_laddr; 493 ip->ip_dst = inp->inp_faddr; 494 495 if (tso) 496 plen = htons(IPPROTO_TCP); 497 else 498 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP); 499 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 500 ip->ip_dst.s_addr, plen); 501 } 502 503 tcp_hdr->th_sport = inp->inp_lport; 504 tcp_hdr->th_dport = inp->inp_fport; 505 tcp_hdr->th_seq = 0; 506 tcp_hdr->th_ack = 0; 507 tcp_hdr->th_x2 = 0; 508 tcp_hdr->th_off = 5; 509 tcp_hdr->th_flags = 0; 510 tcp_hdr->th_win = 0; 511 tcp_hdr->th_urp = 0; 512 } 513 514 /* 515 * Create template to be used to send tcp packets on a connection. 516 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 517 * use for this function is in keepalives, which use tcp_respond. 518 */ 519 struct tcptemp * 520 tcp_maketemplate(struct tcpcb *tp) 521 { 522 struct tcptemp *tmp; 523 524 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 525 return (NULL); 526 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE); 527 return (tmp); 528 } 529 530 void 531 tcp_freetemplate(struct tcptemp *tmp) 532 { 533 mpipe_free(&tcptemp_mpipe, tmp); 534 } 535 536 /* 537 * Send a single message to the TCP at address specified by 538 * the given TCP/IP header. If m == NULL, then we make a copy 539 * of the tcpiphdr at ti and send directly to the addressed host. 540 * This is used to force keep alive messages out using the TCP 541 * template for a connection. If flags are given then we send 542 * a message back to the TCP which originated the * segment ti, 543 * and discard the mbuf containing it and any other attached mbufs. 544 * 545 * In any case the ack and sequence number of the transmitted 546 * segment are as specified by the parameters. 547 * 548 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 549 */ 550 void 551 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 552 tcp_seq ack, tcp_seq seq, int flags) 553 { 554 int tlen; 555 long win = 0; 556 struct route *ro = NULL; 557 struct route sro; 558 struct ip *ip = ipgen; 559 struct tcphdr *nth; 560 int ipflags = 0; 561 struct route_in6 *ro6 = NULL; 562 struct route_in6 sro6; 563 struct ip6_hdr *ip6 = ipgen; 564 boolean_t use_tmpro = TRUE; 565 #ifdef INET6 566 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 567 #else 568 const boolean_t isipv6 = FALSE; 569 #endif 570 571 if (tp != NULL) { 572 if (!(flags & TH_RST)) { 573 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 574 if (win < 0) 575 win = 0; 576 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 577 win = (long)TCP_MAXWIN << tp->rcv_scale; 578 } 579 /* 580 * Don't use the route cache of a listen socket, 581 * it is not MPSAFE; use temporary route cache. 582 */ 583 if (tp->t_state != TCPS_LISTEN) { 584 if (isipv6) 585 ro6 = &tp->t_inpcb->in6p_route; 586 else 587 ro = &tp->t_inpcb->inp_route; 588 use_tmpro = FALSE; 589 } 590 } 591 if (use_tmpro) { 592 if (isipv6) { 593 ro6 = &sro6; 594 bzero(ro6, sizeof *ro6); 595 } else { 596 ro = &sro; 597 bzero(ro, sizeof *ro); 598 } 599 } 600 if (m == NULL) { 601 m = m_gethdr(M_NOWAIT, MT_HEADER); 602 if (m == NULL) 603 return; 604 tlen = 0; 605 m->m_data += max_linkhdr; 606 if (isipv6) { 607 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 608 ip6 = mtod(m, struct ip6_hdr *); 609 nth = (struct tcphdr *)(ip6 + 1); 610 } else { 611 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 612 ip = mtod(m, struct ip *); 613 nth = (struct tcphdr *)(ip + 1); 614 } 615 bcopy(th, nth, sizeof(struct tcphdr)); 616 flags = TH_ACK; 617 } else { 618 m_freem(m->m_next); 619 m->m_next = NULL; 620 m->m_data = (caddr_t)ipgen; 621 /* m_len is set later */ 622 tlen = 0; 623 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 624 if (isipv6) { 625 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 626 nth = (struct tcphdr *)(ip6 + 1); 627 } else { 628 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 629 nth = (struct tcphdr *)(ip + 1); 630 } 631 if (th != nth) { 632 /* 633 * this is usually a case when an extension header 634 * exists between the IPv6 header and the 635 * TCP header. 636 */ 637 nth->th_sport = th->th_sport; 638 nth->th_dport = th->th_dport; 639 } 640 xchg(nth->th_dport, nth->th_sport, n_short); 641 #undef xchg 642 } 643 if (isipv6) { 644 ip6->ip6_flow = 0; 645 ip6->ip6_vfc = IPV6_VERSION; 646 ip6->ip6_nxt = IPPROTO_TCP; 647 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 648 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 649 } else { 650 tlen += sizeof(struct tcpiphdr); 651 ip->ip_len = tlen; 652 ip->ip_ttl = ip_defttl; 653 } 654 m->m_len = tlen; 655 m->m_pkthdr.len = tlen; 656 m->m_pkthdr.rcvif = NULL; 657 nth->th_seq = htonl(seq); 658 nth->th_ack = htonl(ack); 659 nth->th_x2 = 0; 660 nth->th_off = sizeof(struct tcphdr) >> 2; 661 nth->th_flags = flags; 662 if (tp != NULL) 663 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 664 else 665 nth->th_win = htons((u_short)win); 666 nth->th_urp = 0; 667 if (isipv6) { 668 nth->th_sum = 0; 669 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 670 sizeof(struct ip6_hdr), 671 tlen - sizeof(struct ip6_hdr)); 672 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 673 (ro6 && ro6->ro_rt) ? 674 ro6->ro_rt->rt_ifp : NULL); 675 } else { 676 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 677 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 678 m->m_pkthdr.csum_flags = CSUM_TCP; 679 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 680 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr); 681 } 682 #ifdef TCPDEBUG 683 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 684 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 685 #endif 686 if (isipv6) { 687 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 688 tp ? tp->t_inpcb : NULL); 689 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 690 RTFREE(ro6->ro_rt); 691 ro6->ro_rt = NULL; 692 } 693 } else { 694 ipflags |= IP_DEBUGROUTE; 695 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 696 if ((ro == &sro) && (ro->ro_rt != NULL)) { 697 RTFREE(ro->ro_rt); 698 ro->ro_rt = NULL; 699 } 700 } 701 } 702 703 /* 704 * Create a new TCP control block, making an 705 * empty reassembly queue and hooking it to the argument 706 * protocol control block. The `inp' parameter must have 707 * come from the zone allocator set up in tcp_init(). 708 */ 709 struct tcpcb * 710 tcp_newtcpcb(struct inpcb *inp) 711 { 712 struct inp_tp *it; 713 struct tcpcb *tp; 714 #ifdef INET6 715 boolean_t isipv6 = INP_ISIPV6(inp); 716 #else 717 const boolean_t isipv6 = FALSE; 718 #endif 719 720 it = (struct inp_tp *)inp; 721 tp = &it->tcb; 722 bzero(tp, sizeof(struct tcpcb)); 723 TAILQ_INIT(&tp->t_segq); 724 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 725 tp->t_rxtthresh = tcprexmtthresh; 726 727 /* Set up our timeouts. */ 728 tp->tt_rexmt = &it->inp_tp_rexmt; 729 tp->tt_persist = &it->inp_tp_persist; 730 tp->tt_keep = &it->inp_tp_keep; 731 tp->tt_2msl = &it->inp_tp_2msl; 732 tp->tt_delack = &it->inp_tp_delack; 733 tcp_inittimers(tp); 734 735 /* 736 * Zero out timer message. We don't create it here, 737 * since the current CPU may not be the owner of this 738 * inpcb. 739 */ 740 tp->tt_msg = &it->inp_tp_timermsg; 741 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 742 743 tp->t_keepinit = tcp_keepinit; 744 tp->t_keepidle = tcp_keepidle; 745 tp->t_keepintvl = tcp_keepintvl; 746 tp->t_keepcnt = tcp_keepcnt; 747 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt; 748 749 if (tcp_do_ncr) 750 tp->t_flags |= TF_NCR; 751 if (tcp_do_rfc1323) 752 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP); 753 754 tp->t_inpcb = inp; /* XXX */ 755 tp->t_state = TCPS_CLOSED; 756 /* 757 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 758 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 759 * reasonable initial retransmit time. 760 */ 761 tp->t_srtt = TCPTV_SRTTBASE; 762 tp->t_rttvar = 763 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 764 tp->t_rttmin = tcp_rexmit_min; 765 tp->t_rxtcur = TCPTV_RTOBASE; 766 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 767 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 768 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 769 tp->snd_last = ticks; 770 tp->t_rcvtime = ticks; 771 /* 772 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 773 * because the socket may be bound to an IPv6 wildcard address, 774 * which may match an IPv4-mapped IPv6 address. 775 */ 776 inp->inp_ip_ttl = ip_defttl; 777 inp->inp_ppcb = tp; 778 tcp_sack_tcpcb_init(tp); 779 780 tp->tt_sndmore = &it->inp_tp_sndmore; 781 tcp_output_init(tp); 782 783 return (tp); /* XXX */ 784 } 785 786 /* 787 * Drop a TCP connection, reporting the specified error. 788 * If connection is synchronized, then send a RST to peer. 789 */ 790 struct tcpcb * 791 tcp_drop(struct tcpcb *tp, int error) 792 { 793 struct socket *so = tp->t_inpcb->inp_socket; 794 795 if (TCPS_HAVERCVDSYN(tp->t_state)) { 796 tp->t_state = TCPS_CLOSED; 797 tcp_output(tp); 798 tcpstat.tcps_drops++; 799 } else 800 tcpstat.tcps_conndrops++; 801 if (error == ETIMEDOUT && tp->t_softerror) 802 error = tp->t_softerror; 803 so->so_error = error; 804 return (tcp_close(tp)); 805 } 806 807 struct netmsg_listen_detach { 808 struct netmsg_base base; 809 struct tcpcb *nm_tp; 810 struct tcpcb *nm_tp_inh; 811 }; 812 813 static void 814 tcp_listen_detach_handler(netmsg_t msg) 815 { 816 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; 817 struct tcpcb *tp = nmsg->nm_tp; 818 int cpu = mycpuid, nextcpu; 819 820 if (tp->t_flags & TF_LISTEN) 821 syncache_destroy(tp, nmsg->nm_tp_inh); 822 823 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); 824 825 nextcpu = cpu + 1; 826 if (nextcpu < ncpus2) 827 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg); 828 else 829 lwkt_replymsg(&nmsg->base.lmsg, 0); 830 } 831 832 /* 833 * Close a TCP control block: 834 * discard all space held by the tcp 835 * discard internet protocol block 836 * wake up any sleepers 837 */ 838 struct tcpcb * 839 tcp_close(struct tcpcb *tp) 840 { 841 struct tseg_qent *q; 842 struct inpcb *inp = tp->t_inpcb; 843 struct inpcb *inp_inh = NULL; 844 struct tcpcb *tp_inh = NULL; 845 struct socket *so = inp->inp_socket; 846 struct rtentry *rt; 847 boolean_t dosavessthresh; 848 #ifdef INET6 849 boolean_t isipv6 = INP_ISIPV6(inp); 850 #else 851 const boolean_t isipv6 = FALSE; 852 #endif 853 854 if (tp->t_flags & TF_LISTEN) { 855 /* 856 * Pending socket/syncache inheritance 857 * 858 * If this is a listen(2) socket, find another listen(2) 859 * socket in the same local group, which could inherit 860 * the syncache and sockets pending on the completion 861 * and incompletion queues. 862 * 863 * NOTE: 864 * Currently the inheritance could only happen on the 865 * listen(2) sockets w/ SO_REUSEPORT set. 866 */ 867 ASSERT_IN_NETISR(0); 868 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp); 869 if (inp_inh != NULL) 870 tp_inh = intotcpcb(inp_inh); 871 } 872 873 /* 874 * INP_WILDCARD indicates that listen(2) has been called on 875 * this socket. This implies: 876 * - A wildcard inp's hash is replicated for each protocol thread. 877 * - Syncache for this inp grows independently in each protocol 878 * thread. 879 * - There is more than one cpu 880 * 881 * We have to chain a message to the rest of the protocol threads 882 * to cleanup the wildcard hash and the syncache. The cleanup 883 * in the current protocol thread is defered till the end of this 884 * function (syncache_destroy and in_pcbdetach). 885 * 886 * NOTE: 887 * After cleanup the inp's hash and syncache entries, this inp will 888 * no longer be available to the rest of the protocol threads, so we 889 * are safe to whack the inp in the following code. 890 */ 891 if ((inp->inp_flags & INP_WILDCARD) && ncpus2 > 1) { 892 struct netmsg_listen_detach nmsg; 893 894 KKASSERT(so->so_port == netisr_cpuport(0)); 895 ASSERT_IN_NETISR(0); 896 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); 897 898 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, 899 MSGF_PRIORITY, tcp_listen_detach_handler); 900 nmsg.nm_tp = tp; 901 nmsg.nm_tp_inh = tp_inh; 902 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0); 903 } 904 905 KKASSERT(tp->t_state != TCPS_TERMINATING); 906 tp->t_state = TCPS_TERMINATING; 907 908 /* 909 * Make sure that all of our timers are stopped before we 910 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 911 * timers are never used. If timer message is never created 912 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 913 */ 914 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 915 tcp_callout_stop(tp, tp->tt_rexmt); 916 tcp_callout_stop(tp, tp->tt_persist); 917 tcp_callout_stop(tp, tp->tt_keep); 918 tcp_callout_stop(tp, tp->tt_2msl); 919 tcp_callout_stop(tp, tp->tt_delack); 920 } 921 922 if (tp->t_flags & TF_ONOUTPUTQ) { 923 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 924 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 925 tp->t_flags &= ~TF_ONOUTPUTQ; 926 } 927 928 /* 929 * If we got enough samples through the srtt filter, 930 * save the rtt and rttvar in the routing entry. 931 * 'Enough' is arbitrarily defined as the 16 samples. 932 * 16 samples is enough for the srtt filter to converge 933 * to within 5% of the correct value; fewer samples and 934 * we could save a very bogus rtt. 935 * 936 * Don't update the default route's characteristics and don't 937 * update anything that the user "locked". 938 */ 939 if (tp->t_rttupdated >= 16) { 940 u_long i = 0; 941 942 if (isipv6) { 943 struct sockaddr_in6 *sin6; 944 945 if ((rt = inp->in6p_route.ro_rt) == NULL) 946 goto no_valid_rt; 947 sin6 = (struct sockaddr_in6 *)rt_key(rt); 948 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 949 goto no_valid_rt; 950 } else 951 if ((rt = inp->inp_route.ro_rt) == NULL || 952 ((struct sockaddr_in *)rt_key(rt))-> 953 sin_addr.s_addr == INADDR_ANY) 954 goto no_valid_rt; 955 956 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 957 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 958 if (rt->rt_rmx.rmx_rtt && i) 959 /* 960 * filter this update to half the old & half 961 * the new values, converting scale. 962 * See route.h and tcp_var.h for a 963 * description of the scaling constants. 964 */ 965 rt->rt_rmx.rmx_rtt = 966 (rt->rt_rmx.rmx_rtt + i) / 2; 967 else 968 rt->rt_rmx.rmx_rtt = i; 969 tcpstat.tcps_cachedrtt++; 970 } 971 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 972 i = tp->t_rttvar * 973 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 974 if (rt->rt_rmx.rmx_rttvar && i) 975 rt->rt_rmx.rmx_rttvar = 976 (rt->rt_rmx.rmx_rttvar + i) / 2; 977 else 978 rt->rt_rmx.rmx_rttvar = i; 979 tcpstat.tcps_cachedrttvar++; 980 } 981 /* 982 * The old comment here said: 983 * update the pipelimit (ssthresh) if it has been updated 984 * already or if a pipesize was specified & the threshhold 985 * got below half the pipesize. I.e., wait for bad news 986 * before we start updating, then update on both good 987 * and bad news. 988 * 989 * But we want to save the ssthresh even if no pipesize is 990 * specified explicitly in the route, because such 991 * connections still have an implicit pipesize specified 992 * by the global tcp_sendspace. In the absence of a reliable 993 * way to calculate the pipesize, it will have to do. 994 */ 995 i = tp->snd_ssthresh; 996 if (rt->rt_rmx.rmx_sendpipe != 0) 997 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 998 else 999 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 1000 if (dosavessthresh || 1001 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 1002 (rt->rt_rmx.rmx_ssthresh != 0))) { 1003 /* 1004 * convert the limit from user data bytes to 1005 * packets then to packet data bytes. 1006 */ 1007 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 1008 if (i < 2) 1009 i = 2; 1010 i *= tp->t_maxseg + 1011 (isipv6 ? 1012 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1013 sizeof(struct tcpiphdr)); 1014 if (rt->rt_rmx.rmx_ssthresh) 1015 rt->rt_rmx.rmx_ssthresh = 1016 (rt->rt_rmx.rmx_ssthresh + i) / 2; 1017 else 1018 rt->rt_rmx.rmx_ssthresh = i; 1019 tcpstat.tcps_cachedssthresh++; 1020 } 1021 } 1022 1023 no_valid_rt: 1024 /* free the reassembly queue, if any */ 1025 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) { 1026 TAILQ_REMOVE(&tp->t_segq, q, tqe_q); 1027 m_freem(q->tqe_m); 1028 kfree(q, M_TSEGQ); 1029 atomic_add_int(&tcp_reass_qsize, -1); 1030 } 1031 /* throw away SACK blocks in scoreboard*/ 1032 if (TCP_DO_SACK(tp)) 1033 tcp_sack_destroy(&tp->scb); 1034 1035 inp->inp_ppcb = NULL; 1036 soisdisconnected(so); 1037 /* note: pcb detached later on */ 1038 1039 tcp_destroy_timermsg(tp); 1040 tcp_output_cancel(tp); 1041 1042 if (tp->t_flags & TF_LISTEN) { 1043 syncache_destroy(tp, tp_inh); 1044 if (inp_inh != NULL && inp_inh->inp_socket != NULL) { 1045 /* 1046 * Pending sockets inheritance only needs 1047 * to be done once in the current thread, 1048 * i.e. netisr0. 1049 */ 1050 soinherit(so, inp_inh->inp_socket); 1051 } 1052 } 1053 1054 so_async_rcvd_drop(so); 1055 /* Drop the reference for the asynchronized pru_rcvd */ 1056 sofree(so); 1057 1058 /* 1059 * NOTE: 1060 * pcbdetach removes any wildcard hash entry on the current CPU. 1061 */ 1062 #ifdef INET6 1063 if (isipv6) 1064 in6_pcbdetach(inp); 1065 else 1066 #endif 1067 in_pcbdetach(inp); 1068 1069 tcpstat.tcps_closed++; 1070 return (NULL); 1071 } 1072 1073 static __inline void 1074 tcp_drain_oncpu(struct inpcbinfo *pcbinfo) 1075 { 1076 struct inpcbhead *head = &pcbinfo->pcblisthead; 1077 struct inpcb *inpb; 1078 1079 /* 1080 * Since we run in netisr, it is MP safe, even if 1081 * we block during the inpcb list iteration, i.e. 1082 * we don't need to use inpcb marker here. 1083 */ 1084 ASSERT_IN_NETISR(pcbinfo->cpu); 1085 1086 LIST_FOREACH(inpb, head, inp_list) { 1087 struct tcpcb *tcpb; 1088 struct tseg_qent *te; 1089 1090 if (inpb->inp_flags & INP_PLACEMARKER) 1091 continue; 1092 1093 tcpb = intotcpcb(inpb); 1094 KASSERT(tcpb != NULL, ("tcp_drain_oncpu: tcpb is NULL")); 1095 1096 if ((te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) { 1097 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q); 1098 if (te->tqe_th->th_flags & TH_FIN) 1099 tcpb->t_flags &= ~TF_QUEDFIN; 1100 m_freem(te->tqe_m); 1101 kfree(te, M_TSEGQ); 1102 atomic_add_int(&tcp_reass_qsize, -1); 1103 /* retry */ 1104 } 1105 } 1106 } 1107 1108 static void 1109 tcp_drain_dispatch(netmsg_t nmsg) 1110 { 1111 crit_enter(); 1112 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ 1113 crit_exit(); 1114 1115 tcp_drain_oncpu(&tcbinfo[mycpuid]); 1116 } 1117 1118 static void 1119 tcp_drain_ipi(void *arg __unused) 1120 { 1121 int cpu = mycpuid; 1122 struct lwkt_msg *msg = &tcp_drain_netmsg[cpu].lmsg; 1123 1124 crit_enter(); 1125 if (msg->ms_flags & MSGF_DONE) 1126 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); 1127 crit_exit(); 1128 } 1129 1130 void 1131 tcp_drain(void) 1132 { 1133 cpumask_t mask; 1134 1135 if (!do_tcpdrain) 1136 return; 1137 1138 /* 1139 * Walk the tcpbs, if existing, and flush the reassembly queue, 1140 * if there is one... 1141 * XXX: The "Net/3" implementation doesn't imply that the TCP 1142 * reassembly queue should be flushed, but in a situation 1143 * where we're really low on mbufs, this is potentially 1144 * useful. 1145 * YYY: We may consider run tcp_drain_oncpu directly here, 1146 * however, that will require M_WAITOK memory allocation 1147 * for the inpcb marker. 1148 */ 1149 CPUMASK_ASSBMASK(mask, ncpus2); 1150 CPUMASK_ANDMASK(mask, smp_active_mask); 1151 if (CPUMASK_TESTNZERO(mask)) 1152 lwkt_send_ipiq_mask(mask, tcp_drain_ipi, NULL); 1153 } 1154 1155 /* 1156 * Notify a tcp user of an asynchronous error; 1157 * store error as soft error, but wake up user 1158 * (for now, won't do anything until can select for soft error). 1159 * 1160 * Do not wake up user since there currently is no mechanism for 1161 * reporting soft errors (yet - a kqueue filter may be added). 1162 */ 1163 static void 1164 tcp_notify(struct inpcb *inp, int error) 1165 { 1166 struct tcpcb *tp = intotcpcb(inp); 1167 1168 /* 1169 * Ignore some errors if we are hooked up. 1170 * If connection hasn't completed, has retransmitted several times, 1171 * and receives a second error, give up now. This is better 1172 * than waiting a long time to establish a connection that 1173 * can never complete. 1174 */ 1175 if (tp->t_state == TCPS_ESTABLISHED && 1176 (error == EHOSTUNREACH || error == ENETUNREACH || 1177 error == EHOSTDOWN)) { 1178 return; 1179 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1180 tp->t_softerror) 1181 tcp_drop(tp, error); 1182 else 1183 tp->t_softerror = error; 1184 #if 0 1185 wakeup(&so->so_timeo); 1186 sorwakeup(so); 1187 sowwakeup(so); 1188 #endif 1189 } 1190 1191 static int 1192 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1193 { 1194 int error, i, n; 1195 struct inpcb *marker; 1196 struct inpcb *inp; 1197 int origcpu, ccpu; 1198 1199 error = 0; 1200 n = 0; 1201 1202 /* 1203 * The process of preparing the TCB list is too time-consuming and 1204 * resource-intensive to repeat twice on every request. 1205 */ 1206 if (req->oldptr == NULL) { 1207 for (ccpu = 0; ccpu < ncpus2; ++ccpu) 1208 n += tcbinfo[ccpu].ipi_count; 1209 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1210 return (0); 1211 } 1212 1213 if (req->newptr != NULL) 1214 return (EPERM); 1215 1216 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1217 marker->inp_flags |= INP_PLACEMARKER; 1218 1219 /* 1220 * OK, now we're committed to doing something. Run the inpcb list 1221 * for each cpu in the system and construct the output. Use a 1222 * list placemarker to deal with list changes occuring during 1223 * copyout blockages (but otherwise depend on being on the correct 1224 * cpu to avoid races). 1225 */ 1226 origcpu = mycpu->gd_cpuid; 1227 for (ccpu = 0; ccpu < ncpus2 && error == 0; ++ccpu) { 1228 caddr_t inp_ppcb; 1229 struct xtcpcb xt; 1230 1231 lwkt_migratecpu(ccpu); 1232 1233 n = tcbinfo[ccpu].ipi_count; 1234 1235 LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list); 1236 i = 0; 1237 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1238 /* 1239 * process a snapshot of pcbs, ignoring placemarkers 1240 * and using our own to allow SYSCTL_OUT to block. 1241 */ 1242 LIST_REMOVE(marker, inp_list); 1243 LIST_INSERT_AFTER(inp, marker, inp_list); 1244 1245 if (inp->inp_flags & INP_PLACEMARKER) 1246 continue; 1247 if (prison_xinpcb(req->td, inp)) 1248 continue; 1249 1250 xt.xt_len = sizeof xt; 1251 bcopy(inp, &xt.xt_inp, sizeof *inp); 1252 inp_ppcb = inp->inp_ppcb; 1253 if (inp_ppcb != NULL) 1254 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1255 else 1256 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1257 if (inp->inp_socket) 1258 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1259 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1260 break; 1261 ++i; 1262 } 1263 LIST_REMOVE(marker, inp_list); 1264 if (error == 0 && i < n) { 1265 bzero(&xt, sizeof xt); 1266 xt.xt_len = sizeof xt; 1267 while (i < n) { 1268 error = SYSCTL_OUT(req, &xt, sizeof xt); 1269 if (error) 1270 break; 1271 ++i; 1272 } 1273 } 1274 } 1275 1276 /* 1277 * Make sure we are on the same cpu we were on originally, since 1278 * higher level callers expect this. Also don't pollute caches with 1279 * migrated userland data by (eventually) returning to userland 1280 * on a different cpu. 1281 */ 1282 lwkt_migratecpu(origcpu); 1283 kfree(marker, M_TEMP); 1284 return (error); 1285 } 1286 1287 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1288 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1289 1290 static int 1291 tcp_getcred(SYSCTL_HANDLER_ARGS) 1292 { 1293 struct sockaddr_in addrs[2]; 1294 struct ucred cred0, *cred = NULL; 1295 struct inpcb *inp; 1296 int cpu, origcpu, error; 1297 1298 error = priv_check(req->td, PRIV_ROOT); 1299 if (error != 0) 1300 return (error); 1301 error = SYSCTL_IN(req, addrs, sizeof addrs); 1302 if (error != 0) 1303 return (error); 1304 1305 origcpu = mycpuid; 1306 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1307 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1308 1309 lwkt_migratecpu(cpu); 1310 1311 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1312 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1313 if (inp == NULL || inp->inp_socket == NULL) { 1314 error = ENOENT; 1315 } else if (inp->inp_socket->so_cred != NULL) { 1316 cred0 = *(inp->inp_socket->so_cred); 1317 cred = &cred0; 1318 } 1319 1320 lwkt_migratecpu(origcpu); 1321 1322 if (error) 1323 return (error); 1324 1325 return SYSCTL_OUT(req, cred, sizeof(struct ucred)); 1326 } 1327 1328 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1329 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1330 1331 #ifdef INET6 1332 static int 1333 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1334 { 1335 struct sockaddr_in6 addrs[2]; 1336 struct inpcb *inp; 1337 int error; 1338 1339 error = priv_check(req->td, PRIV_ROOT); 1340 if (error != 0) 1341 return (error); 1342 error = SYSCTL_IN(req, addrs, sizeof addrs); 1343 if (error != 0) 1344 return (error); 1345 crit_enter(); 1346 inp = in6_pcblookup_hash(&tcbinfo[0], 1347 &addrs[1].sin6_addr, addrs[1].sin6_port, 1348 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1349 if (inp == NULL || inp->inp_socket == NULL) { 1350 error = ENOENT; 1351 goto out; 1352 } 1353 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1354 out: 1355 crit_exit(); 1356 return (error); 1357 } 1358 1359 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1360 0, 0, 1361 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1362 #endif 1363 1364 struct netmsg_tcp_notify { 1365 struct netmsg_base base; 1366 inp_notify_t nm_notify; 1367 struct in_addr nm_faddr; 1368 int nm_arg; 1369 }; 1370 1371 static void 1372 tcp_notifyall_oncpu(netmsg_t msg) 1373 { 1374 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1375 int nextcpu; 1376 1377 in_pcbnotifyall(&tcbinfo[mycpuid], nm->nm_faddr, 1378 nm->nm_arg, nm->nm_notify); 1379 1380 nextcpu = mycpuid + 1; 1381 if (nextcpu < ncpus2) 1382 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg); 1383 else 1384 lwkt_replymsg(&nm->base.lmsg, 0); 1385 } 1386 1387 inp_notify_t 1388 tcp_get_inpnotify(int cmd, const struct sockaddr *sa, 1389 int *arg, struct ip **ip0, int *cpuid) 1390 { 1391 struct ip *ip = *ip0; 1392 struct in_addr faddr; 1393 inp_notify_t notify = tcp_notify; 1394 1395 faddr = ((const struct sockaddr_in *)sa)->sin_addr; 1396 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1397 return NULL; 1398 1399 *arg = inetctlerrmap[cmd]; 1400 if (cmd == PRC_QUENCH) { 1401 notify = tcp_quench; 1402 } else if (icmp_may_rst && 1403 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1404 cmd == PRC_UNREACH_PORT || 1405 cmd == PRC_TIMXCEED_INTRANS) && 1406 ip != NULL) { 1407 notify = tcp_drop_syn_sent; 1408 } else if (cmd == PRC_MSGSIZE) { 1409 const struct icmp *icmp = (const struct icmp *) 1410 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1411 1412 *arg = ntohs(icmp->icmp_nextmtu); 1413 notify = tcp_mtudisc; 1414 } else if (PRC_IS_REDIRECT(cmd)) { 1415 ip = NULL; 1416 notify = in_rtchange; 1417 } else if (cmd == PRC_HOSTDEAD) { 1418 ip = NULL; 1419 } else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1420 return NULL; 1421 } 1422 1423 if (cpuid != NULL) { 1424 if (ip == NULL) { 1425 /* Go through all CPUs */ 1426 *cpuid = ncpus; 1427 } else { 1428 const struct tcphdr *th; 1429 1430 th = (const struct tcphdr *) 1431 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); 1432 *cpuid = tcp_addrcpu(faddr.s_addr, th->th_dport, 1433 ip->ip_src.s_addr, th->th_sport); 1434 } 1435 } 1436 1437 *ip0 = ip; 1438 return notify; 1439 } 1440 1441 void 1442 tcp_ctlinput(netmsg_t msg) 1443 { 1444 int cmd = msg->ctlinput.nm_cmd; 1445 struct sockaddr *sa = msg->ctlinput.nm_arg; 1446 struct ip *ip = msg->ctlinput.nm_extra; 1447 struct in_addr faddr; 1448 inp_notify_t notify; 1449 int arg, cpuid; 1450 1451 notify = tcp_get_inpnotify(cmd, sa, &arg, &ip, &cpuid); 1452 if (notify == NULL) 1453 goto done; 1454 1455 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1456 if (ip != NULL) { 1457 const struct tcphdr *th; 1458 struct inpcb *inp; 1459 1460 if (cpuid != mycpuid) 1461 goto done; 1462 1463 th = (const struct tcphdr *) 1464 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); 1465 inp = in_pcblookup_hash(&tcbinfo[mycpuid], faddr, th->th_dport, 1466 ip->ip_src, th->th_sport, 0, NULL); 1467 if (inp != NULL && inp->inp_socket != NULL) { 1468 tcp_seq icmpseq = htonl(th->th_seq); 1469 struct tcpcb *tp = intotcpcb(inp); 1470 1471 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1472 SEQ_LT(icmpseq, tp->snd_max)) 1473 notify(inp, arg); 1474 } else { 1475 struct in_conninfo inc; 1476 1477 inc.inc_fport = th->th_dport; 1478 inc.inc_lport = th->th_sport; 1479 inc.inc_faddr = faddr; 1480 inc.inc_laddr = ip->ip_src; 1481 #ifdef INET6 1482 inc.inc_isipv6 = 0; 1483 #endif 1484 syncache_unreach(&inc, th); 1485 } 1486 } else if (msg->ctlinput.nm_direct) { 1487 if (cpuid != ncpus && cpuid != mycpuid) 1488 goto done; 1489 if (mycpuid >= ncpus2) 1490 goto done; 1491 1492 in_pcbnotifyall(&tcbinfo[mycpuid], faddr, arg, notify); 1493 } else { 1494 struct netmsg_tcp_notify *nm; 1495 1496 ASSERT_IN_NETISR(0); 1497 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1498 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1499 0, tcp_notifyall_oncpu); 1500 nm->nm_faddr = faddr; 1501 nm->nm_arg = arg; 1502 nm->nm_notify = notify; 1503 1504 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg); 1505 } 1506 done: 1507 lwkt_replymsg(&msg->lmsg, 0); 1508 } 1509 1510 #ifdef INET6 1511 1512 void 1513 tcp6_ctlinput(netmsg_t msg) 1514 { 1515 int cmd = msg->ctlinput.nm_cmd; 1516 struct sockaddr *sa = msg->ctlinput.nm_arg; 1517 void *d = msg->ctlinput.nm_extra; 1518 struct tcphdr th; 1519 inp_notify_t notify = tcp_notify; 1520 struct ip6_hdr *ip6; 1521 struct mbuf *m; 1522 struct ip6ctlparam *ip6cp = NULL; 1523 const struct sockaddr_in6 *sa6_src = NULL; 1524 int off; 1525 struct tcp_portonly { 1526 u_int16_t th_sport; 1527 u_int16_t th_dport; 1528 } *thp; 1529 int arg; 1530 1531 if (sa->sa_family != AF_INET6 || 1532 sa->sa_len != sizeof(struct sockaddr_in6)) { 1533 goto out; 1534 } 1535 1536 arg = 0; 1537 if (cmd == PRC_QUENCH) 1538 notify = tcp_quench; 1539 else if (cmd == PRC_MSGSIZE) { 1540 struct ip6ctlparam *ip6cp = d; 1541 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1542 1543 arg = ntohl(icmp6->icmp6_mtu); 1544 notify = tcp_mtudisc; 1545 } else if (!PRC_IS_REDIRECT(cmd) && 1546 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1547 goto out; 1548 } 1549 1550 /* if the parameter is from icmp6, decode it. */ 1551 if (d != NULL) { 1552 ip6cp = (struct ip6ctlparam *)d; 1553 m = ip6cp->ip6c_m; 1554 ip6 = ip6cp->ip6c_ip6; 1555 off = ip6cp->ip6c_off; 1556 sa6_src = ip6cp->ip6c_src; 1557 } else { 1558 m = NULL; 1559 ip6 = NULL; 1560 off = 0; /* fool gcc */ 1561 sa6_src = &sa6_any; 1562 } 1563 1564 if (ip6 != NULL) { 1565 struct in_conninfo inc; 1566 /* 1567 * XXX: We assume that when IPV6 is non NULL, 1568 * M and OFF are valid. 1569 */ 1570 1571 /* check if we can safely examine src and dst ports */ 1572 if (m->m_pkthdr.len < off + sizeof *thp) 1573 goto out; 1574 1575 bzero(&th, sizeof th); 1576 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1577 1578 in6_pcbnotify(&tcbinfo[0], sa, th.th_dport, 1579 (struct sockaddr *)ip6cp->ip6c_src, 1580 th.th_sport, cmd, arg, notify); 1581 1582 inc.inc_fport = th.th_dport; 1583 inc.inc_lport = th.th_sport; 1584 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1585 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1586 inc.inc_isipv6 = 1; 1587 syncache_unreach(&inc, &th); 1588 } else { 1589 in6_pcbnotify(&tcbinfo[0], sa, 0, 1590 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1591 } 1592 out: 1593 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1594 } 1595 1596 #endif 1597 1598 /* 1599 * Following is where TCP initial sequence number generation occurs. 1600 * 1601 * There are two places where we must use initial sequence numbers: 1602 * 1. In SYN-ACK packets. 1603 * 2. In SYN packets. 1604 * 1605 * All ISNs for SYN-ACK packets are generated by the syncache. See 1606 * tcp_syncache.c for details. 1607 * 1608 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1609 * depends on this property. In addition, these ISNs should be 1610 * unguessable so as to prevent connection hijacking. To satisfy 1611 * the requirements of this situation, the algorithm outlined in 1612 * RFC 1948 is used to generate sequence numbers. 1613 * 1614 * Implementation details: 1615 * 1616 * Time is based off the system timer, and is corrected so that it 1617 * increases by one megabyte per second. This allows for proper 1618 * recycling on high speed LANs while still leaving over an hour 1619 * before rollover. 1620 * 1621 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1622 * between seeding of isn_secret. This is normally set to zero, 1623 * as reseeding should not be necessary. 1624 * 1625 */ 1626 1627 #define ISN_BYTES_PER_SECOND 1048576 1628 1629 u_char isn_secret[32]; 1630 int isn_last_reseed; 1631 MD5_CTX isn_ctx; 1632 1633 tcp_seq 1634 tcp_new_isn(struct tcpcb *tp) 1635 { 1636 u_int32_t md5_buffer[4]; 1637 tcp_seq new_isn; 1638 1639 /* Seed if this is the first use, reseed if requested. */ 1640 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1641 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1642 < (u_int)ticks))) { 1643 read_random_unlimited(&isn_secret, sizeof isn_secret); 1644 isn_last_reseed = ticks; 1645 } 1646 1647 /* Compute the md5 hash and return the ISN. */ 1648 MD5Init(&isn_ctx); 1649 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1650 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1651 #ifdef INET6 1652 if (INP_ISIPV6(tp->t_inpcb)) { 1653 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1654 sizeof(struct in6_addr)); 1655 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1656 sizeof(struct in6_addr)); 1657 } else 1658 #endif 1659 { 1660 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1661 sizeof(struct in_addr)); 1662 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1663 sizeof(struct in_addr)); 1664 } 1665 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1666 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1667 new_isn = (tcp_seq) md5_buffer[0]; 1668 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1669 return (new_isn); 1670 } 1671 1672 /* 1673 * When a source quench is received, close congestion window 1674 * to one segment. We will gradually open it again as we proceed. 1675 */ 1676 void 1677 tcp_quench(struct inpcb *inp, int error) 1678 { 1679 struct tcpcb *tp = intotcpcb(inp); 1680 1681 KASSERT(tp != NULL, ("tcp_quench: tp is NULL")); 1682 tp->snd_cwnd = tp->t_maxseg; 1683 tp->snd_wacked = 0; 1684 } 1685 1686 /* 1687 * When a specific ICMP unreachable message is received and the 1688 * connection state is SYN-SENT, drop the connection. This behavior 1689 * is controlled by the icmp_may_rst sysctl. 1690 */ 1691 void 1692 tcp_drop_syn_sent(struct inpcb *inp, int error) 1693 { 1694 struct tcpcb *tp = intotcpcb(inp); 1695 1696 KASSERT(tp != NULL, ("tcp_drop_syn_sent: tp is NULL")); 1697 if (tp->t_state == TCPS_SYN_SENT) 1698 tcp_drop(tp, error); 1699 } 1700 1701 /* 1702 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1703 * based on the new value in the route. Also nudge TCP to send something, 1704 * since we know the packet we just sent was dropped. 1705 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1706 */ 1707 void 1708 tcp_mtudisc(struct inpcb *inp, int mtu) 1709 { 1710 struct tcpcb *tp = intotcpcb(inp); 1711 struct rtentry *rt; 1712 struct socket *so = inp->inp_socket; 1713 int maxopd, mss; 1714 #ifdef INET6 1715 boolean_t isipv6 = INP_ISIPV6(inp); 1716 #else 1717 const boolean_t isipv6 = FALSE; 1718 #endif 1719 1720 KASSERT(tp != NULL, ("tcp_mtudisc: tp is NULL")); 1721 1722 /* 1723 * If no MTU is provided in the ICMP message, use the 1724 * next lower likely value, as specified in RFC 1191. 1725 */ 1726 if (mtu == 0) { 1727 int oldmtu; 1728 1729 oldmtu = tp->t_maxopd + 1730 (isipv6 ? 1731 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1732 sizeof(struct tcpiphdr)); 1733 mtu = ip_next_mtu(oldmtu, 0); 1734 } 1735 1736 if (isipv6) 1737 rt = tcp_rtlookup6(&inp->inp_inc); 1738 else 1739 rt = tcp_rtlookup(&inp->inp_inc); 1740 if (rt != NULL) { 1741 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1742 mtu = rt->rt_rmx.rmx_mtu; 1743 1744 maxopd = mtu - 1745 (isipv6 ? 1746 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1747 sizeof(struct tcpiphdr)); 1748 1749 /* 1750 * XXX - The following conditional probably violates the TCP 1751 * spec. The problem is that, since we don't know the 1752 * other end's MSS, we are supposed to use a conservative 1753 * default. But, if we do that, then MTU discovery will 1754 * never actually take place, because the conservative 1755 * default is much less than the MTUs typically seen 1756 * on the Internet today. For the moment, we'll sweep 1757 * this under the carpet. 1758 * 1759 * The conservative default might not actually be a problem 1760 * if the only case this occurs is when sending an initial 1761 * SYN with options and data to a host we've never talked 1762 * to before. Then, they will reply with an MSS value which 1763 * will get recorded and the new parameters should get 1764 * recomputed. For Further Study. 1765 */ 1766 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1767 maxopd = rt->rt_rmx.rmx_mssopt; 1768 } else 1769 maxopd = mtu - 1770 (isipv6 ? 1771 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1772 sizeof(struct tcpiphdr)); 1773 1774 if (tp->t_maxopd <= maxopd) 1775 return; 1776 tp->t_maxopd = maxopd; 1777 1778 mss = maxopd; 1779 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1780 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1781 mss -= TCPOLEN_TSTAMP_APPA; 1782 1783 /* round down to multiple of MCLBYTES */ 1784 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1785 if (mss > MCLBYTES) 1786 mss &= ~(MCLBYTES - 1); 1787 #else 1788 if (mss > MCLBYTES) 1789 mss = (mss / MCLBYTES) * MCLBYTES; 1790 #endif 1791 1792 if (so->so_snd.ssb_hiwat < mss) 1793 mss = so->so_snd.ssb_hiwat; 1794 1795 tp->t_maxseg = mss; 1796 tp->t_rtttime = 0; 1797 tp->snd_nxt = tp->snd_una; 1798 tcp_output(tp); 1799 tcpstat.tcps_mturesent++; 1800 } 1801 1802 /* 1803 * Look-up the routing entry to the peer of this inpcb. If no route 1804 * is found and it cannot be allocated the return NULL. This routine 1805 * is called by TCP routines that access the rmx structure and by tcp_mss 1806 * to get the interface MTU. 1807 */ 1808 struct rtentry * 1809 tcp_rtlookup(struct in_conninfo *inc) 1810 { 1811 struct route *ro = &inc->inc_route; 1812 1813 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1814 /* No route yet, so try to acquire one */ 1815 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1816 /* 1817 * unused portions of the structure MUST be zero'd 1818 * out because rtalloc() treats it as opaque data 1819 */ 1820 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1821 ro->ro_dst.sa_family = AF_INET; 1822 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1823 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1824 inc->inc_faddr; 1825 rtalloc(ro); 1826 } 1827 } 1828 return (ro->ro_rt); 1829 } 1830 1831 #ifdef INET6 1832 struct rtentry * 1833 tcp_rtlookup6(struct in_conninfo *inc) 1834 { 1835 struct route_in6 *ro6 = &inc->inc6_route; 1836 1837 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1838 /* No route yet, so try to acquire one */ 1839 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1840 /* 1841 * unused portions of the structure MUST be zero'd 1842 * out because rtalloc() treats it as opaque data 1843 */ 1844 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1845 ro6->ro_dst.sin6_family = AF_INET6; 1846 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1847 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1848 rtalloc((struct route *)ro6); 1849 } 1850 } 1851 return (ro6->ro_rt); 1852 } 1853 #endif 1854 1855 #ifdef IPSEC 1856 /* compute ESP/AH header size for TCP, including outer IP header. */ 1857 size_t 1858 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1859 { 1860 struct inpcb *inp; 1861 struct mbuf *m; 1862 size_t hdrsiz; 1863 struct ip *ip; 1864 struct tcphdr *th; 1865 1866 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1867 return (0); 1868 MGETHDR(m, M_NOWAIT, MT_DATA); 1869 if (!m) 1870 return (0); 1871 1872 #ifdef INET6 1873 if (INP_ISIPV6(inp)) { 1874 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1875 1876 th = (struct tcphdr *)(ip6 + 1); 1877 m->m_pkthdr.len = m->m_len = 1878 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1879 tcp_fillheaders(tp, ip6, th, FALSE); 1880 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1881 } else 1882 #endif 1883 { 1884 ip = mtod(m, struct ip *); 1885 th = (struct tcphdr *)(ip + 1); 1886 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1887 tcp_fillheaders(tp, ip, th, FALSE); 1888 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1889 } 1890 1891 m_free(m); 1892 return (hdrsiz); 1893 } 1894 #endif 1895 1896 /* 1897 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1898 * 1899 * This code attempts to calculate the bandwidth-delay product as a 1900 * means of determining the optimal window size to maximize bandwidth, 1901 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1902 * routers. This code also does a fairly good job keeping RTTs in check 1903 * across slow links like modems. We implement an algorithm which is very 1904 * similar (but not meant to be) TCP/Vegas. The code operates on the 1905 * transmitter side of a TCP connection and so only effects the transmit 1906 * side of the connection. 1907 * 1908 * BACKGROUND: TCP makes no provision for the management of buffer space 1909 * at the end points or at the intermediate routers and switches. A TCP 1910 * stream, whether using NewReno or not, will eventually buffer as 1911 * many packets as it is able and the only reason this typically works is 1912 * due to the fairly small default buffers made available for a connection 1913 * (typicaly 16K or 32K). As machines use larger windows and/or window 1914 * scaling it is now fairly easy for even a single TCP connection to blow-out 1915 * all available buffer space not only on the local interface, but on 1916 * intermediate routers and switches as well. NewReno makes a misguided 1917 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1918 * then backing off, then steadily increasing the window again until another 1919 * failure occurs, ad-infinitum. This results in terrible oscillation that 1920 * is only made worse as network loads increase and the idea of intentionally 1921 * blowing out network buffers is, frankly, a terrible way to manage network 1922 * resources. 1923 * 1924 * It is far better to limit the transmit window prior to the failure 1925 * condition being achieved. There are two general ways to do this: First 1926 * you can 'scan' through different transmit window sizes and locate the 1927 * point where the RTT stops increasing, indicating that you have filled the 1928 * pipe, then scan backwards until you note that RTT stops decreasing, then 1929 * repeat ad-infinitum. This method works in principle but has severe 1930 * implementation issues due to RTT variances, timer granularity, and 1931 * instability in the algorithm which can lead to many false positives and 1932 * create oscillations as well as interact badly with other TCP streams 1933 * implementing the same algorithm. 1934 * 1935 * The second method is to limit the window to the bandwidth delay product 1936 * of the link. This is the method we implement. RTT variances and our 1937 * own manipulation of the congestion window, bwnd, can potentially 1938 * destabilize the algorithm. For this reason we have to stabilize the 1939 * elements used to calculate the window. We do this by using the minimum 1940 * observed RTT, the long term average of the observed bandwidth, and 1941 * by adding two segments worth of slop. It isn't perfect but it is able 1942 * to react to changing conditions and gives us a very stable basis on 1943 * which to extend the algorithm. 1944 */ 1945 void 1946 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1947 { 1948 u_long bw; 1949 u_long ibw; 1950 u_long bwnd; 1951 int save_ticks; 1952 int delta_ticks; 1953 1954 /* 1955 * If inflight_enable is disabled in the middle of a tcp connection, 1956 * make sure snd_bwnd is effectively disabled. 1957 */ 1958 if (!tcp_inflight_enable) { 1959 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1960 tp->snd_bandwidth = 0; 1961 return; 1962 } 1963 1964 /* 1965 * Validate the delta time. If a connection is new or has been idle 1966 * a long time we have to reset the bandwidth calculator. 1967 */ 1968 save_ticks = ticks; 1969 cpu_ccfence(); 1970 delta_ticks = save_ticks - tp->t_bw_rtttime; 1971 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1972 tp->t_bw_rtttime = save_ticks; 1973 tp->t_bw_rtseq = ack_seq; 1974 if (tp->snd_bandwidth == 0) 1975 tp->snd_bandwidth = tcp_inflight_start; 1976 return; 1977 } 1978 1979 /* 1980 * A delta of at least 1 tick is required. Waiting 2 ticks will 1981 * result in better (bw) accuracy. More than that and the ramp-up 1982 * will be too slow. 1983 */ 1984 if (delta_ticks == 0 || delta_ticks == 1) 1985 return; 1986 1987 /* 1988 * Sanity check, plus ignore pure window update acks. 1989 */ 1990 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1991 return; 1992 1993 /* 1994 * Figure out the bandwidth. Due to the tick granularity this 1995 * is a very rough number and it MUST be averaged over a fairly 1996 * long period of time. XXX we need to take into account a link 1997 * that is not using all available bandwidth, but for now our 1998 * slop will ramp us up if this case occurs and the bandwidth later 1999 * increases. 2000 */ 2001 ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 2002 tp->t_bw_rtttime = save_ticks; 2003 tp->t_bw_rtseq = ack_seq; 2004 bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4; 2005 2006 tp->snd_bandwidth = bw; 2007 2008 /* 2009 * Calculate the semi-static bandwidth delay product, plus two maximal 2010 * segments. The additional slop puts us squarely in the sweet 2011 * spot and also handles the bandwidth run-up case. Without the 2012 * slop we could be locking ourselves into a lower bandwidth. 2013 * 2014 * At very high speeds the bw calculation can become overly sensitive 2015 * and error prone when delta_ticks is low (e.g. usually 1). To deal 2016 * with the problem the stab must be scaled to the bw. A stab of 50 2017 * (the default) increases the bw for the purposes of the bwnd 2018 * calculation by 5%. 2019 * 2020 * Situations Handled: 2021 * (1) Prevents over-queueing of packets on LANs, especially on 2022 * high speed LANs, allowing larger TCP buffers to be 2023 * specified, and also does a good job preventing 2024 * over-queueing of packets over choke points like modems 2025 * (at least for the transmit side). 2026 * 2027 * (2) Is able to handle changing network loads (bandwidth 2028 * drops so bwnd drops, bandwidth increases so bwnd 2029 * increases). 2030 * 2031 * (3) Theoretically should stabilize in the face of multiple 2032 * connections implementing the same algorithm (this may need 2033 * a little work). 2034 * 2035 * (4) Stability value (defaults to 20 = 2 maximal packets) can 2036 * be adjusted with a sysctl but typically only needs to be on 2037 * very slow connections. A value no smaller then 5 should 2038 * be used, but only reduce this default if you have no other 2039 * choice. 2040 */ 2041 2042 #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt) 2043 bw += bw * tcp_inflight_stab / 1000; 2044 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 2045 (int)tp->t_maxseg * 2; 2046 #undef USERTT 2047 2048 if (tcp_inflight_debug > 0) { 2049 static int ltime; 2050 if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) { 2051 ltime = save_ticks; 2052 kprintf("%p ibw %ld bw %ld rttvar %d srtt %d " 2053 "bwnd %ld delta %d snd_win %ld\n", 2054 tp, ibw, bw, tp->t_rttvar, tp->t_srtt, 2055 bwnd, delta_ticks, tp->snd_wnd); 2056 } 2057 } 2058 if ((long)bwnd < tcp_inflight_min) 2059 bwnd = tcp_inflight_min; 2060 if (bwnd > tcp_inflight_max) 2061 bwnd = tcp_inflight_max; 2062 if ((long)bwnd < tp->t_maxseg * 2) 2063 bwnd = tp->t_maxseg * 2; 2064 tp->snd_bwnd = bwnd; 2065 } 2066 2067 static void 2068 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs) 2069 { 2070 struct rtentry *rt; 2071 struct inpcb *inp = tp->t_inpcb; 2072 #ifdef INET6 2073 boolean_t isipv6 = INP_ISIPV6(inp); 2074 #else 2075 const boolean_t isipv6 = FALSE; 2076 #endif 2077 2078 /* XXX */ 2079 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT) 2080 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 2081 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT) 2082 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 2083 2084 if (isipv6) 2085 rt = tcp_rtlookup6(&inp->inp_inc); 2086 else 2087 rt = tcp_rtlookup(&inp->inp_inc); 2088 if (rt == NULL || 2089 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT || 2090 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) { 2091 *maxsegs = tcp_iw_maxsegs; 2092 *capsegs = tcp_iw_capsegs; 2093 return; 2094 } 2095 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs; 2096 *capsegs = rt->rt_rmx.rmx_iwcapsegs; 2097 } 2098 2099 u_long 2100 tcp_initial_window(struct tcpcb *tp) 2101 { 2102 if (tcp_do_rfc3390) { 2103 /* 2104 * RFC3390: 2105 * "If the SYN or SYN/ACK is lost, the initial window 2106 * used by a sender after a correctly transmitted SYN 2107 * MUST be one segment consisting of MSS bytes." 2108 * 2109 * However, we do something a little bit more aggressive 2110 * then RFC3390 here: 2111 * - Only if time spent in the SYN or SYN|ACK retransmition 2112 * >= 3 seconds, the IW is reduced. We do this mainly 2113 * because when RFC3390 is published, the initial RTO is 2114 * still 3 seconds (the threshold we test here), while 2115 * after RFC6298, the initial RTO is 1 second. This 2116 * behaviour probably still falls within the spirit of 2117 * RFC3390. 2118 * - When IW is reduced, 2*MSS is used instead of 1*MSS. 2119 * Mainly to avoid sender and receiver deadlock until 2120 * delayed ACK timer expires. And even RFC2581 does not 2121 * try to reduce IW upon SYN or SYN|ACK retransmition 2122 * timeout. 2123 * 2124 * See also: 2125 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03 2126 */ 2127 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) { 2128 return (2 * tp->t_maxseg); 2129 } else { 2130 u_long maxsegs, capsegs; 2131 2132 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs); 2133 return min(maxsegs * tp->t_maxseg, 2134 max(2 * tp->t_maxseg, capsegs * 1460)); 2135 } 2136 } else { 2137 /* 2138 * Even RFC2581 (back to 1999) allows 2*SMSS IW. 2139 * 2140 * Mainly to avoid sender and receiver deadlock 2141 * until delayed ACK timer expires. 2142 */ 2143 return (2 * tp->t_maxseg); 2144 } 2145 } 2146 2147 #ifdef TCP_SIGNATURE 2148 /* 2149 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2150 * 2151 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2152 * When called from tcp_input(), we can be sure that th_sum has been 2153 * zeroed out and verified already. 2154 * 2155 * Return 0 if successful, otherwise return -1. 2156 * 2157 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2158 * search with the destination IP address, and a 'magic SPI' to be 2159 * determined by the application. This is hardcoded elsewhere to 1179 2160 * right now. Another branch of this code exists which uses the SPD to 2161 * specify per-application flows but it is unstable. 2162 */ 2163 int 2164 tcpsignature_compute( 2165 struct mbuf *m, /* mbuf chain */ 2166 int len, /* length of TCP data */ 2167 int optlen, /* length of TCP options */ 2168 u_char *buf, /* storage for MD5 digest */ 2169 u_int direction) /* direction of flow */ 2170 { 2171 struct ippseudo ippseudo; 2172 MD5_CTX ctx; 2173 int doff; 2174 struct ip *ip; 2175 struct ipovly *ipovly; 2176 struct secasvar *sav; 2177 struct tcphdr *th; 2178 #ifdef INET6 2179 struct ip6_hdr *ip6; 2180 struct in6_addr in6; 2181 uint32_t plen; 2182 uint16_t nhdr; 2183 #endif /* INET6 */ 2184 u_short savecsum; 2185 2186 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 2187 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 2188 /* 2189 * Extract the destination from the IP header in the mbuf. 2190 */ 2191 ip = mtod(m, struct ip *); 2192 #ifdef INET6 2193 ip6 = NULL; /* Make the compiler happy. */ 2194 #endif /* INET6 */ 2195 /* 2196 * Look up an SADB entry which matches the address found in 2197 * the segment. 2198 */ 2199 switch (IP_VHL_V(ip->ip_vhl)) { 2200 case IPVERSION: 2201 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2202 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2203 break; 2204 #ifdef INET6 2205 case (IPV6_VERSION >> 4): 2206 ip6 = mtod(m, struct ip6_hdr *); 2207 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2208 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2209 break; 2210 #endif /* INET6 */ 2211 default: 2212 return (EINVAL); 2213 /* NOTREACHED */ 2214 break; 2215 } 2216 if (sav == NULL) { 2217 kprintf("%s: SADB lookup failed\n", __func__); 2218 return (EINVAL); 2219 } 2220 MD5Init(&ctx); 2221 2222 /* 2223 * Step 1: Update MD5 hash with IP pseudo-header. 2224 * 2225 * XXX The ippseudo header MUST be digested in network byte order, 2226 * or else we'll fail the regression test. Assume all fields we've 2227 * been doing arithmetic on have been in host byte order. 2228 * XXX One cannot depend on ipovly->ih_len here. When called from 2229 * tcp_output(), the underlying ip_len member has not yet been set. 2230 */ 2231 switch (IP_VHL_V(ip->ip_vhl)) { 2232 case IPVERSION: 2233 ipovly = (struct ipovly *)ip; 2234 ippseudo.ippseudo_src = ipovly->ih_src; 2235 ippseudo.ippseudo_dst = ipovly->ih_dst; 2236 ippseudo.ippseudo_pad = 0; 2237 ippseudo.ippseudo_p = IPPROTO_TCP; 2238 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2239 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2240 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2241 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2242 break; 2243 #ifdef INET6 2244 /* 2245 * RFC 2385, 2.0 Proposal 2246 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2247 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2248 * extended next header value (to form 32 bits), and 32-bit segment 2249 * length. 2250 * Note: Upper-Layer Packet Length comes before Next Header. 2251 */ 2252 case (IPV6_VERSION >> 4): 2253 in6 = ip6->ip6_src; 2254 in6_clearscope(&in6); 2255 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2256 in6 = ip6->ip6_dst; 2257 in6_clearscope(&in6); 2258 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2259 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2260 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2261 nhdr = 0; 2262 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2263 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2264 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2265 nhdr = IPPROTO_TCP; 2266 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2267 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2268 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2269 break; 2270 #endif /* INET6 */ 2271 default: 2272 return (EINVAL); 2273 /* NOTREACHED */ 2274 break; 2275 } 2276 /* 2277 * Step 2: Update MD5 hash with TCP header, excluding options. 2278 * The TCP checksum must be set to zero. 2279 */ 2280 savecsum = th->th_sum; 2281 th->th_sum = 0; 2282 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2283 th->th_sum = savecsum; 2284 /* 2285 * Step 3: Update MD5 hash with TCP segment data. 2286 * Use m_apply() to avoid an early m_pullup(). 2287 */ 2288 if (len > 0) 2289 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2290 /* 2291 * Step 4: Update MD5 hash with shared secret. 2292 */ 2293 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2294 MD5Final(buf, &ctx); 2295 key_sa_recordxfer(sav, m); 2296 key_freesav(sav); 2297 return (0); 2298 } 2299 2300 int 2301 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2302 { 2303 2304 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2305 return (0); 2306 } 2307 #endif /* TCP_SIGNATURE */ 2308 2309 static void 2310 tcp_drop_sysctl_dispatch(netmsg_t nmsg) 2311 { 2312 struct lwkt_msg *lmsg = &nmsg->lmsg; 2313 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2314 struct sockaddr_storage *addrs = lmsg->u.ms_resultp; 2315 int error; 2316 struct sockaddr_in *fin, *lin; 2317 #ifdef INET6 2318 struct sockaddr_in6 *fin6, *lin6; 2319 struct in6_addr f6, l6; 2320 #endif 2321 struct inpcb *inp; 2322 2323 switch (addrs[0].ss_family) { 2324 #ifdef INET6 2325 case AF_INET6: 2326 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2327 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2328 error = in6_embedscope(&f6, fin6, NULL, NULL); 2329 if (error) 2330 goto done; 2331 error = in6_embedscope(&l6, lin6, NULL, NULL); 2332 if (error) 2333 goto done; 2334 inp = in6_pcblookup_hash(&tcbinfo[mycpuid], &f6, 2335 fin6->sin6_port, &l6, lin6->sin6_port, FALSE, NULL); 2336 break; 2337 #endif 2338 #ifdef INET 2339 case AF_INET: 2340 fin = (struct sockaddr_in *)&addrs[0]; 2341 lin = (struct sockaddr_in *)&addrs[1]; 2342 inp = in_pcblookup_hash(&tcbinfo[mycpuid], fin->sin_addr, 2343 fin->sin_port, lin->sin_addr, lin->sin_port, FALSE, NULL); 2344 break; 2345 #endif 2346 default: 2347 /* 2348 * Must not reach here, since the address family was 2349 * checked in sysctl handler. 2350 */ 2351 panic("unknown address family %d", addrs[0].ss_family); 2352 } 2353 if (inp != NULL) { 2354 struct tcpcb *tp = intotcpcb(inp); 2355 2356 KASSERT((inp->inp_flags & INP_WILDCARD) == 0, 2357 ("in wildcard hash")); 2358 KASSERT(tp != NULL, ("tcp_drop_sysctl_dispatch: tp is NULL")); 2359 KASSERT((tp->t_flags & TF_LISTEN) == 0, ("listen socket")); 2360 tcp_drop(tp, ECONNABORTED); 2361 error = 0; 2362 } else { 2363 error = ESRCH; 2364 } 2365 #ifdef INET6 2366 done: 2367 #endif 2368 lwkt_replymsg(lmsg, error); 2369 } 2370 2371 static int 2372 sysctl_tcp_drop(SYSCTL_HANDLER_ARGS) 2373 { 2374 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2375 struct sockaddr_storage addrs[2]; 2376 struct sockaddr_in *fin, *lin; 2377 #ifdef INET6 2378 struct sockaddr_in6 *fin6, *lin6; 2379 #endif 2380 struct netmsg_base nmsg; 2381 struct lwkt_msg *lmsg = &nmsg.lmsg; 2382 struct lwkt_port *port = NULL; 2383 int error; 2384 2385 fin = lin = NULL; 2386 #ifdef INET6 2387 fin6 = lin6 = NULL; 2388 #endif 2389 error = 0; 2390 2391 if (req->oldptr != NULL || req->oldlen != 0) 2392 return (EINVAL); 2393 if (req->newptr == NULL) 2394 return (EPERM); 2395 if (req->newlen < sizeof(addrs)) 2396 return (ENOMEM); 2397 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2398 if (error) 2399 return (error); 2400 2401 switch (addrs[0].ss_family) { 2402 #ifdef INET6 2403 case AF_INET6: 2404 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2405 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2406 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2407 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2408 return (EINVAL); 2409 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr) || 2410 IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2411 return (EADDRNOTAVAIL); 2412 #if 0 2413 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2414 if (error) 2415 return (error); 2416 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2417 if (error) 2418 return (error); 2419 #endif 2420 port = tcp6_addrport(); 2421 break; 2422 #endif 2423 #ifdef INET 2424 case AF_INET: 2425 fin = (struct sockaddr_in *)&addrs[0]; 2426 lin = (struct sockaddr_in *)&addrs[1]; 2427 if (fin->sin_len != sizeof(struct sockaddr_in) || 2428 lin->sin_len != sizeof(struct sockaddr_in)) 2429 return (EINVAL); 2430 port = tcp_addrport(fin->sin_addr.s_addr, fin->sin_port, 2431 lin->sin_addr.s_addr, lin->sin_port); 2432 break; 2433 #endif 2434 default: 2435 return (EINVAL); 2436 } 2437 2438 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0, 2439 tcp_drop_sysctl_dispatch); 2440 lmsg->u.ms_resultp = addrs; 2441 return lwkt_domsg(port, lmsg, 0); 2442 } 2443 2444 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, drop, 2445 CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2446 0, sysctl_tcp_drop, "", "Drop TCP connection"); 2447