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_inet.h" 67 #include "opt_inet6.h" 68 #include "opt_ipsec.h" 69 #include "opt_tcpdebug.h" 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/callout.h> 74 #include <sys/kernel.h> 75 #include <sys/sysctl.h> 76 #include <sys/malloc.h> 77 #include <sys/mpipe.h> 78 #include <sys/mbuf.h> 79 #ifdef INET6 80 #include <sys/domain.h> 81 #endif 82 #include <sys/proc.h> 83 #include <sys/priv.h> 84 #include <sys/socket.h> 85 #include <sys/socketops.h> 86 #include <sys/socketvar.h> 87 #include <sys/protosw.h> 88 #include <sys/random.h> 89 #include <sys/in_cksum.h> 90 #include <sys/ktr.h> 91 92 #include <net/route.h> 93 #include <net/if.h> 94 #include <net/netisr2.h> 95 96 #define _IP_VHL 97 #include <netinet/in.h> 98 #include <netinet/in_systm.h> 99 #include <netinet/ip.h> 100 #include <netinet/ip6.h> 101 #include <netinet/in_pcb.h> 102 #include <netinet6/in6_pcb.h> 103 #include <netinet/in_var.h> 104 #include <netinet/ip_var.h> 105 #include <netinet6/ip6_var.h> 106 #include <netinet/ip_icmp.h> 107 #ifdef INET6 108 #include <netinet/icmp6.h> 109 #endif 110 #include <netinet/tcp.h> 111 #include <netinet/tcp_fsm.h> 112 #include <netinet/tcp_seq.h> 113 #include <netinet/tcp_timer.h> 114 #include <netinet/tcp_timer2.h> 115 #include <netinet/tcp_var.h> 116 #include <netinet6/tcp6_var.h> 117 #include <netinet/tcpip.h> 118 #ifdef TCPDEBUG 119 #include <netinet/tcp_debug.h> 120 #endif 121 #include <netinet6/ip6protosw.h> 122 123 #ifdef IPSEC 124 #include <netinet6/ipsec.h> 125 #include <netproto/key/key.h> 126 #ifdef INET6 127 #include <netinet6/ipsec6.h> 128 #endif 129 #endif 130 131 #ifdef FAST_IPSEC 132 #include <netproto/ipsec/ipsec.h> 133 #ifdef INET6 134 #include <netproto/ipsec/ipsec6.h> 135 #endif 136 #define IPSEC 137 #endif 138 139 #include <sys/md5.h> 140 #include <machine/smp.h> 141 142 #include <sys/msgport2.h> 143 #include <sys/mplock2.h> 144 #include <net/netmsg2.h> 145 146 #if !defined(KTR_TCP) 147 #define KTR_TCP KTR_ALL 148 #endif 149 /* 150 KTR_INFO_MASTER(tcp); 151 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 152 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 153 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 154 #define logtcp(name) KTR_LOG(tcp_ ## name) 155 */ 156 157 #define TCP_IW_MAXSEGS_DFLT 4 158 #define TCP_IW_CAPSEGS_DFLT 4 159 160 struct inpcbinfo tcbinfo[MAXCPU]; 161 struct tcpcbackqhead tcpcbackq[MAXCPU]; 162 163 int tcp_mssdflt = TCP_MSS; 164 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 165 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 166 167 #ifdef INET6 168 int tcp_v6mssdflt = TCP6_MSS; 169 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 170 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 171 #endif 172 173 /* 174 * Minimum MSS we accept and use. This prevents DoS attacks where 175 * we are forced to a ridiculous low MSS like 20 and send hundreds 176 * of packets instead of one. The effect scales with the available 177 * bandwidth and quickly saturates the CPU and network interface 178 * with packet generation and sending. Set to zero to disable MINMSS 179 * checking. This setting prevents us from sending too small packets. 180 */ 181 int tcp_minmss = TCP_MINMSS; 182 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 183 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 184 185 #if 0 186 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 187 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 188 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 189 #endif 190 191 int tcp_do_rfc1323 = 1; 192 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 193 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 194 195 static int tcp_tcbhashsize = 0; 196 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 197 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 198 199 static int do_tcpdrain = 1; 200 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 201 "Enable tcp_drain routine for extra help when low on mbufs"); 202 203 static int icmp_may_rst = 1; 204 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 205 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 206 207 static int tcp_isn_reseed_interval = 0; 208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 209 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 210 211 /* 212 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 213 * by default, but with generous values which should allow maximal 214 * bandwidth. In particular, the slop defaults to 50 (5 packets). 215 * 216 * The reason for doing this is that the limiter is the only mechanism we 217 * have which seems to do a really good job preventing receiver RX rings 218 * on network interfaces from getting blown out. Even though GigE/10GigE 219 * is supposed to flow control it looks like either it doesn't actually 220 * do it or Open Source drivers do not properly enable it. 221 * 222 * People using the limiter to reduce bottlenecks on slower WAN connections 223 * should set the slop to 20 (2 packets). 224 */ 225 static int tcp_inflight_enable = 1; 226 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 227 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 228 229 static int tcp_inflight_debug = 0; 230 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 231 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 232 233 /* 234 * NOTE: tcp_inflight_start is essentially the starting receive window 235 * for a connection. If set too low then fetches over tcp 236 * connections will take noticably longer to ramp-up over 237 * high-latency connections. 6144 is too low for a default, 238 * use something more reasonable. 239 */ 240 static int tcp_inflight_start = 33792; 241 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_start, CTLFLAG_RW, 242 &tcp_inflight_start, 0, "Start value for TCP inflight window"); 243 244 static int tcp_inflight_min = 6144; 245 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 246 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 247 248 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 249 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 250 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 251 252 static int tcp_inflight_stab = 50; 253 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 254 &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)"); 255 256 static int tcp_inflight_adjrtt = 2; 257 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW, 258 &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)"); 259 260 static int tcp_do_rfc3390 = 1; 261 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW, 262 &tcp_do_rfc3390, 0, 263 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)"); 264 265 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 266 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW, 267 &tcp_iw_maxsegs, 0, "TCP IW segments max"); 268 269 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 270 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW, 271 &tcp_iw_capsegs, 0, "TCP IW segments"); 272 273 int tcp_low_rtobase = 1; 274 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW, 275 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)"); 276 277 static int tcp_do_ncr = 1; 278 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW, 279 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)"); 280 281 int tcp_ncr_rxtthresh_max = 16; 282 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW, 283 &tcp_ncr_rxtthresh_max, 0, 284 "Non-Congestion Robustness (RFC 4653), DupThresh upper limit"); 285 286 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 287 static struct malloc_pipe tcptemp_mpipe; 288 289 static void tcp_willblock(void); 290 static void tcp_notify (struct inpcb *, int); 291 292 struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign; 293 struct tcp_state_count tcpstate_count[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 < netisr_ncpus; ++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) * netisr_ncpus, M_PCB, 389 M_WAITOK); 390 391 for (cpu = 0; cpu < netisr_ncpus; 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, cpu); 397 in_pcbportinfo_set(ticb, portinfo, netisr_ncpus); 398 ticb->wildcardhashbase = hashinit(hashsize, M_PCB, 399 &ticb->wildcardhashmask); 400 ticb->localgrphashbase = hashinit(hashsize, M_PCB, 401 &ticb->localgrphashmask); 402 ticb->ipi_size = sizeof(struct inp_tp); 403 TAILQ_INIT(&tcpcbackq[cpu]); 404 } 405 406 tcp_reass_maxseg = nmbclusters / 16; 407 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 408 409 #ifdef INET6 410 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 411 #else 412 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 413 #endif 414 if (max_protohdr < TCP_MINPROTOHDR) 415 max_protohdr = TCP_MINPROTOHDR; 416 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 417 panic("tcp_init"); 418 #undef TCP_MINPROTOHDR 419 420 /* 421 * Initialize TCP statistics counters for each CPU. 422 */ 423 for (cpu = 0; cpu < netisr_ncpus; ++cpu) 424 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 425 426 /* 427 * Initialize netmsgs for TCP drain 428 */ 429 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 430 netmsg_init(&tcp_drain_netmsg[cpu], NULL, &netisr_adone_rport, 431 MSGF_PRIORITY, tcp_drain_dispatch); 432 } 433 434 syncache_init(); 435 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP); 436 } 437 438 static void 439 tcp_willblock(void) 440 { 441 struct tcpcb *tp; 442 int cpu = mycpu->gd_cpuid; 443 444 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 445 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 446 tp->t_flags &= ~TF_ONOUTPUTQ; 447 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 448 tcp_output(tp); 449 } 450 } 451 452 /* 453 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 454 * tcp_template used to store this data in mbufs, but we now recopy it out 455 * of the tcpcb each time to conserve mbufs. 456 */ 457 void 458 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso) 459 { 460 struct inpcb *inp = tp->t_inpcb; 461 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 462 463 #ifdef INET6 464 if (INP_ISIPV6(inp)) { 465 struct ip6_hdr *ip6; 466 467 ip6 = (struct ip6_hdr *)ip_ptr; 468 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 469 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 470 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 471 (IPV6_VERSION & IPV6_VERSION_MASK); 472 ip6->ip6_nxt = IPPROTO_TCP; 473 ip6->ip6_plen = sizeof(struct tcphdr); 474 ip6->ip6_src = inp->in6p_laddr; 475 ip6->ip6_dst = inp->in6p_faddr; 476 tcp_hdr->th_sum = 0; 477 } else 478 #endif 479 { 480 struct ip *ip = (struct ip *) ip_ptr; 481 u_int plen; 482 483 ip->ip_vhl = IP_VHL_BORING; 484 ip->ip_tos = 0; 485 ip->ip_len = 0; 486 ip->ip_id = 0; 487 ip->ip_off = 0; 488 ip->ip_ttl = 0; 489 ip->ip_sum = 0; 490 ip->ip_p = IPPROTO_TCP; 491 ip->ip_src = inp->inp_laddr; 492 ip->ip_dst = inp->inp_faddr; 493 494 if (tso) 495 plen = htons(IPPROTO_TCP); 496 else 497 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP); 498 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 499 ip->ip_dst.s_addr, plen); 500 } 501 502 tcp_hdr->th_sport = inp->inp_lport; 503 tcp_hdr->th_dport = inp->inp_fport; 504 tcp_hdr->th_seq = 0; 505 tcp_hdr->th_ack = 0; 506 tcp_hdr->th_x2 = 0; 507 tcp_hdr->th_off = 5; 508 tcp_hdr->th_flags = 0; 509 tcp_hdr->th_win = 0; 510 tcp_hdr->th_urp = 0; 511 } 512 513 /* 514 * Create template to be used to send tcp packets on a connection. 515 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 516 * use for this function is in keepalives, which use tcp_respond. 517 */ 518 struct tcptemp * 519 tcp_maketemplate(struct tcpcb *tp) 520 { 521 struct tcptemp *tmp; 522 523 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 524 return (NULL); 525 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE); 526 return (tmp); 527 } 528 529 void 530 tcp_freetemplate(struct tcptemp *tmp) 531 { 532 mpipe_free(&tcptemp_mpipe, tmp); 533 } 534 535 /* 536 * Send a single message to the TCP at address specified by 537 * the given TCP/IP header. If m == NULL, then we make a copy 538 * of the tcpiphdr at ti and send directly to the addressed host. 539 * This is used to force keep alive messages out using the TCP 540 * template for a connection. If flags are given then we send 541 * a message back to the TCP which originated the * segment ti, 542 * and discard the mbuf containing it and any other attached mbufs. 543 * 544 * In any case the ack and sequence number of the transmitted 545 * segment are as specified by the parameters. 546 * 547 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 548 */ 549 void 550 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 551 tcp_seq ack, tcp_seq seq, int flags) 552 { 553 int tlen; 554 long win = 0; 555 struct route *ro = NULL; 556 struct route sro; 557 struct ip *ip = ipgen; 558 struct tcphdr *nth; 559 int ipflags = 0; 560 struct route_in6 *ro6 = NULL; 561 struct route_in6 sro6; 562 struct ip6_hdr *ip6 = ipgen; 563 struct inpcb *inp = NULL; 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 inp = tp->t_inpcb; 573 if (!(flags & TH_RST)) { 574 win = ssb_space(&inp->inp_socket->so_rcv); 575 if (win < 0) 576 win = 0; 577 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 578 win = (long)TCP_MAXWIN << tp->rcv_scale; 579 } 580 /* 581 * Don't use the route cache of a listen socket, 582 * it is not MPSAFE; use temporary route cache. 583 */ 584 if (tp->t_state != TCPS_LISTEN) { 585 if (isipv6) 586 ro6 = &inp->in6p_route; 587 else 588 ro = &inp->inp_route; 589 use_tmpro = FALSE; 590 } 591 } 592 if (use_tmpro) { 593 if (isipv6) { 594 ro6 = &sro6; 595 bzero(ro6, sizeof *ro6); 596 } else { 597 ro = &sro; 598 bzero(ro, sizeof *ro); 599 } 600 } 601 if (m == NULL) { 602 m = m_gethdr(M_NOWAIT, MT_HEADER); 603 if (m == NULL) 604 return; 605 tlen = 0; 606 m->m_data += max_linkhdr; 607 if (isipv6) { 608 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 609 ip6 = mtod(m, struct ip6_hdr *); 610 nth = (struct tcphdr *)(ip6 + 1); 611 } else { 612 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 613 ip = mtod(m, struct ip *); 614 nth = (struct tcphdr *)(ip + 1); 615 } 616 bcopy(th, nth, sizeof(struct tcphdr)); 617 flags = TH_ACK; 618 } else { 619 m_freem(m->m_next); 620 m->m_next = NULL; 621 m->m_data = (caddr_t)ipgen; 622 /* m_len is set later */ 623 tlen = 0; 624 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 625 if (isipv6) { 626 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 627 nth = (struct tcphdr *)(ip6 + 1); 628 } else { 629 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 630 nth = (struct tcphdr *)(ip + 1); 631 } 632 if (th != nth) { 633 /* 634 * this is usually a case when an extension header 635 * exists between the IPv6 header and the 636 * TCP header. 637 */ 638 nth->th_sport = th->th_sport; 639 nth->th_dport = th->th_dport; 640 } 641 xchg(nth->th_dport, nth->th_sport, n_short); 642 #undef xchg 643 } 644 if (isipv6) { 645 ip6->ip6_flow = 0; 646 ip6->ip6_vfc = IPV6_VERSION; 647 ip6->ip6_nxt = IPPROTO_TCP; 648 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 649 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 650 } else { 651 tlen += sizeof(struct tcpiphdr); 652 ip->ip_len = tlen; 653 ip->ip_ttl = ip_defttl; 654 } 655 m->m_len = tlen; 656 m->m_pkthdr.len = tlen; 657 m->m_pkthdr.rcvif = NULL; 658 nth->th_seq = htonl(seq); 659 nth->th_ack = htonl(ack); 660 nth->th_x2 = 0; 661 nth->th_off = sizeof(struct tcphdr) >> 2; 662 nth->th_flags = flags; 663 if (tp != NULL) 664 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 665 else 666 nth->th_win = htons((u_short)win); 667 nth->th_urp = 0; 668 if (isipv6) { 669 nth->th_sum = 0; 670 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 671 sizeof(struct ip6_hdr), 672 tlen - sizeof(struct ip6_hdr)); 673 ip6->ip6_hlim = in6_selecthlim(inp, 674 (ro6 && ro6->ro_rt) ? 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 || (inp->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, inp); 688 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 689 RTFREE(ro6->ro_rt); 690 ro6->ro_rt = NULL; 691 } 692 } else { 693 if (inp != NULL && (inp->inp_flags & INP_HASH)) 694 m_sethash(m, inp->inp_hashval); 695 ipflags |= IP_DEBUGROUTE; 696 ip_output(m, NULL, ro, ipflags, NULL, inp); 697 if ((ro == &sro) && (ro->ro_rt != NULL)) { 698 RTFREE(ro->ro_rt); 699 ro->ro_rt = NULL; 700 } 701 } 702 } 703 704 /* 705 * Create a new TCP control block, making an 706 * empty reassembly queue and hooking it to the argument 707 * protocol control block. The `inp' parameter must have 708 * come from the zone allocator set up in tcp_init(). 709 */ 710 void 711 tcp_newtcpcb(struct inpcb *inp) 712 { 713 struct inp_tp *it; 714 struct tcpcb *tp; 715 #ifdef INET6 716 boolean_t isipv6 = INP_ISIPV6(inp); 717 #else 718 const boolean_t isipv6 = FALSE; 719 #endif 720 721 it = (struct inp_tp *)inp; 722 tp = &it->tcb; 723 bzero(tp, sizeof(struct tcpcb)); 724 TAILQ_INIT(&tp->t_segq); 725 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 726 tp->t_rxtthresh = tcprexmtthresh; 727 728 /* Set up our timeouts. */ 729 tp->tt_rexmt = &it->inp_tp_rexmt; 730 tp->tt_persist = &it->inp_tp_persist; 731 tp->tt_keep = &it->inp_tp_keep; 732 tp->tt_2msl = &it->inp_tp_2msl; 733 tp->tt_delack = &it->inp_tp_delack; 734 tcp_inittimers(tp); 735 736 /* 737 * Zero out timer message. We don't create it here, 738 * since the current CPU may not be the owner of this 739 * inpcb. 740 */ 741 tp->tt_msg = &it->inp_tp_timermsg; 742 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 743 744 tp->t_keepinit = tcp_keepinit; 745 tp->t_keepidle = tcp_keepidle; 746 tp->t_keepintvl = tcp_keepintvl; 747 tp->t_keepcnt = tcp_keepcnt; 748 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt; 749 750 if (tcp_do_ncr) 751 tp->t_flags |= TF_NCR; 752 if (tcp_do_rfc1323) 753 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP); 754 755 tp->t_inpcb = inp; /* XXX */ 756 TCP_STATE_INIT(tp); 757 /* 758 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 759 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 760 * reasonable initial retransmit time. 761 */ 762 tp->t_srtt = TCPTV_SRTTBASE; 763 tp->t_rttvar = 764 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 765 tp->t_rttmin = tcp_rexmit_min; 766 tp->t_rxtcur = TCPTV_RTOBASE; 767 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 768 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 769 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 770 tp->snd_last = ticks; 771 tp->t_rcvtime = ticks; 772 /* 773 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 774 * because the socket may be bound to an IPv6 wildcard address, 775 * which may match an IPv4-mapped IPv6 address. 776 */ 777 inp->inp_ip_ttl = ip_defttl; 778 inp->inp_ppcb = tp; 779 tcp_sack_tcpcb_init(tp); 780 781 tp->tt_sndmore = &it->inp_tp_sndmore; 782 tcp_output_init(tp); 783 } 784 785 /* 786 * Drop a TCP connection, reporting the specified error. 787 * If connection is synchronized, then send a RST to peer. 788 */ 789 struct tcpcb * 790 tcp_drop(struct tcpcb *tp, int error) 791 { 792 struct socket *so = tp->t_inpcb->inp_socket; 793 794 if (TCPS_HAVERCVDSYN(tp->t_state)) { 795 TCP_STATE_CHANGE(tp, TCPS_CLOSED); 796 tcp_output(tp); 797 tcpstat.tcps_drops++; 798 } else 799 tcpstat.tcps_conndrops++; 800 if (error == ETIMEDOUT && tp->t_softerror) 801 error = tp->t_softerror; 802 so->so_error = error; 803 return (tcp_close(tp)); 804 } 805 806 struct netmsg_listen_detach { 807 struct netmsg_base base; 808 struct tcpcb *nm_tp; 809 struct tcpcb *nm_tp_inh; 810 }; 811 812 static void 813 tcp_listen_detach_handler(netmsg_t msg) 814 { 815 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; 816 struct tcpcb *tp = nmsg->nm_tp; 817 int cpu = mycpuid, nextcpu; 818 819 if (tp->t_flags & TF_LISTEN) { 820 syncache_destroy(tp, nmsg->nm_tp_inh); 821 tcp_pcbport_merge_oncpu(tp); 822 } 823 824 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); 825 826 nextcpu = cpu + 1; 827 if (nextcpu < netisr_ncpus) 828 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg); 829 else 830 lwkt_replymsg(&nmsg->base.lmsg, 0); 831 } 832 833 /* 834 * Close a TCP control block: 835 * discard all space held by the tcp 836 * discard internet protocol block 837 * wake up any sleepers 838 */ 839 struct tcpcb * 840 tcp_close(struct tcpcb *tp) 841 { 842 struct tseg_qent *q; 843 struct inpcb *inp = tp->t_inpcb; 844 struct inpcb *inp_inh = NULL; 845 struct tcpcb *tp_inh = NULL; 846 struct socket *so = inp->inp_socket; 847 struct rtentry *rt; 848 boolean_t dosavessthresh; 849 #ifdef INET6 850 boolean_t isipv6 = INP_ISIPV6(inp); 851 #else 852 const boolean_t isipv6 = FALSE; 853 #endif 854 855 if (tp->t_flags & TF_LISTEN) { 856 /* 857 * Pending socket/syncache inheritance 858 * 859 * If this is a listen(2) socket, find another listen(2) 860 * socket in the same local group, which could inherit 861 * the syncache and sockets pending on the completion 862 * and incompletion queues. 863 * 864 * NOTE: 865 * Currently the inheritance could only happen on the 866 * listen(2) sockets w/ SO_REUSEPORT set. 867 */ 868 ASSERT_IN_NETISR(0); 869 inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp); 870 if (inp_inh != NULL) 871 tp_inh = intotcpcb(inp_inh); 872 } 873 874 /* 875 * INP_WILDCARD indicates that listen(2) has been called on 876 * this socket. This implies: 877 * - A wildcard inp's hash is replicated for each protocol thread. 878 * - Syncache for this inp grows independently in each protocol 879 * thread. 880 * - There is more than one cpu 881 * 882 * We have to chain a message to the rest of the protocol threads 883 * to cleanup the wildcard hash and the syncache. The cleanup 884 * in the current protocol thread is defered till the end of this 885 * function (syncache_destroy and in_pcbdetach). 886 * 887 * NOTE: 888 * After cleanup the inp's hash and syncache entries, this inp will 889 * no longer be available to the rest of the protocol threads, so we 890 * are safe to whack the inp in the following code. 891 */ 892 if ((inp->inp_flags & INP_WILDCARD) && netisr_ncpus > 1) { 893 struct netmsg_listen_detach nmsg; 894 895 KKASSERT(so->so_port == netisr_cpuport(0)); 896 ASSERT_IN_NETISR(0); 897 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); 898 899 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, 900 MSGF_PRIORITY, tcp_listen_detach_handler); 901 nmsg.nm_tp = tp; 902 nmsg.nm_tp_inh = tp_inh; 903 lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0); 904 } 905 906 TCP_STATE_TERM(tp); 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 tcp_pcbport_merge_oncpu(tp); 1045 tcp_pcbport_destroy(tp); 1046 if (inp_inh != NULL && inp_inh->inp_socket != NULL) { 1047 /* 1048 * Pending sockets inheritance only needs 1049 * to be done once in the current thread, 1050 * i.e. netisr0. 1051 */ 1052 soinherit(so, inp_inh->inp_socket); 1053 } 1054 } 1055 KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache is not destroyed")); 1056 1057 so_async_rcvd_drop(so); 1058 /* Drop the reference for the asynchronized pru_rcvd */ 1059 sofree(so); 1060 1061 /* 1062 * NOTE: 1063 * - Remove self from listen tcpcb per-cpu port cache _before_ 1064 * pcbdetach. 1065 * - pcbdetach removes any wildcard hash entry on the current CPU. 1066 */ 1067 tcp_pcbport_remove(inp); 1068 #ifdef INET6 1069 if (isipv6) 1070 in6_pcbdetach(inp); 1071 else 1072 #endif 1073 in_pcbdetach(inp); 1074 1075 tcpstat.tcps_closed++; 1076 return (NULL); 1077 } 1078 1079 static __inline void 1080 tcp_drain_oncpu(struct inpcbinfo *pcbinfo) 1081 { 1082 struct inpcbhead *head = &pcbinfo->pcblisthead; 1083 struct inpcb *inpb; 1084 1085 /* 1086 * Since we run in netisr, it is MP safe, even if 1087 * we block during the inpcb list iteration, i.e. 1088 * we don't need to use inpcb marker here. 1089 */ 1090 ASSERT_IN_NETISR(pcbinfo->cpu); 1091 1092 LIST_FOREACH(inpb, head, inp_list) { 1093 struct tcpcb *tcpb; 1094 struct tseg_qent *te; 1095 1096 if (inpb->inp_flags & INP_PLACEMARKER) 1097 continue; 1098 1099 tcpb = intotcpcb(inpb); 1100 KASSERT(tcpb != NULL, ("tcp_drain_oncpu: tcpb is NULL")); 1101 1102 if ((te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) { 1103 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q); 1104 if (te->tqe_th->th_flags & TH_FIN) 1105 tcpb->t_flags &= ~TF_QUEDFIN; 1106 m_freem(te->tqe_m); 1107 kfree(te, M_TSEGQ); 1108 atomic_add_int(&tcp_reass_qsize, -1); 1109 /* retry */ 1110 } 1111 } 1112 } 1113 1114 static void 1115 tcp_drain_dispatch(netmsg_t nmsg) 1116 { 1117 crit_enter(); 1118 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ 1119 crit_exit(); 1120 1121 tcp_drain_oncpu(&tcbinfo[mycpuid]); 1122 } 1123 1124 static void 1125 tcp_drain_ipi(void *arg __unused) 1126 { 1127 int cpu = mycpuid; 1128 struct lwkt_msg *msg = &tcp_drain_netmsg[cpu].lmsg; 1129 1130 crit_enter(); 1131 if (msg->ms_flags & MSGF_DONE) 1132 lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); 1133 crit_exit(); 1134 } 1135 1136 void 1137 tcp_drain(void) 1138 { 1139 cpumask_t mask; 1140 1141 if (!do_tcpdrain) 1142 return; 1143 1144 /* 1145 * Walk the tcpbs, if existing, and flush the reassembly queue, 1146 * if there is one... 1147 * XXX: The "Net/3" implementation doesn't imply that the TCP 1148 * reassembly queue should be flushed, but in a situation 1149 * where we're really low on mbufs, this is potentially 1150 * useful. 1151 * YYY: We may consider run tcp_drain_oncpu directly here, 1152 * however, that will require M_WAITOK memory allocation 1153 * for the inpcb marker. 1154 */ 1155 CPUMASK_ASSBMASK(mask, netisr_ncpus); 1156 CPUMASK_ANDMASK(mask, smp_active_mask); 1157 if (CPUMASK_TESTNZERO(mask)) 1158 lwkt_send_ipiq_mask(mask, tcp_drain_ipi, NULL); 1159 } 1160 1161 /* 1162 * Notify a tcp user of an asynchronous error; 1163 * store error as soft error, but wake up user 1164 * (for now, won't do anything until can select for soft error). 1165 * 1166 * Do not wake up user since there currently is no mechanism for 1167 * reporting soft errors (yet - a kqueue filter may be added). 1168 */ 1169 static void 1170 tcp_notify(struct inpcb *inp, int error) 1171 { 1172 struct tcpcb *tp = intotcpcb(inp); 1173 1174 /* 1175 * Ignore some errors if we are hooked up. 1176 * If connection hasn't completed, has retransmitted several times, 1177 * and receives a second error, give up now. This is better 1178 * than waiting a long time to establish a connection that 1179 * can never complete. 1180 */ 1181 if (tp->t_state == TCPS_ESTABLISHED && 1182 (error == EHOSTUNREACH || error == ENETUNREACH || 1183 error == EHOSTDOWN)) { 1184 return; 1185 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1186 tp->t_softerror) 1187 tcp_drop(tp, error); 1188 else 1189 tp->t_softerror = error; 1190 #if 0 1191 wakeup(&so->so_timeo); 1192 sorwakeup(so); 1193 sowwakeup(so); 1194 #endif 1195 } 1196 1197 static int 1198 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1199 { 1200 int error, i, n; 1201 struct inpcb *marker; 1202 struct inpcb *inp; 1203 int origcpu, ccpu; 1204 1205 error = 0; 1206 n = 0; 1207 1208 /* 1209 * The process of preparing the TCB list is too time-consuming and 1210 * resource-intensive to repeat twice on every request. 1211 */ 1212 if (req->oldptr == NULL) { 1213 for (ccpu = 0; ccpu < netisr_ncpus; ++ccpu) 1214 n += tcbinfo[ccpu].ipi_count; 1215 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1216 return (0); 1217 } 1218 1219 if (req->newptr != NULL) 1220 return (EPERM); 1221 1222 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1223 marker->inp_flags |= INP_PLACEMARKER; 1224 1225 /* 1226 * OK, now we're committed to doing something. Run the inpcb list 1227 * for each cpu in the system and construct the output. Use a 1228 * list placemarker to deal with list changes occuring during 1229 * copyout blockages (but otherwise depend on being on the correct 1230 * cpu to avoid races). 1231 */ 1232 origcpu = mycpu->gd_cpuid; 1233 for (ccpu = 0; ccpu < netisr_ncpus && error == 0; ++ccpu) { 1234 caddr_t inp_ppcb; 1235 struct xtcpcb xt; 1236 1237 lwkt_migratecpu(ccpu); 1238 1239 n = tcbinfo[ccpu].ipi_count; 1240 1241 LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list); 1242 i = 0; 1243 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1244 /* 1245 * process a snapshot of pcbs, ignoring placemarkers 1246 * and using our own to allow SYSCTL_OUT to block. 1247 */ 1248 LIST_REMOVE(marker, inp_list); 1249 LIST_INSERT_AFTER(inp, marker, inp_list); 1250 1251 if (inp->inp_flags & INP_PLACEMARKER) 1252 continue; 1253 if (prison_xinpcb(req->td, inp)) 1254 continue; 1255 1256 xt.xt_len = sizeof xt; 1257 bcopy(inp, &xt.xt_inp, sizeof *inp); 1258 inp_ppcb = inp->inp_ppcb; 1259 if (inp_ppcb != NULL) 1260 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1261 else 1262 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1263 if (inp->inp_socket) 1264 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1265 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1266 break; 1267 ++i; 1268 } 1269 LIST_REMOVE(marker, inp_list); 1270 if (error == 0 && i < n) { 1271 bzero(&xt, sizeof xt); 1272 xt.xt_len = sizeof xt; 1273 while (i < n) { 1274 error = SYSCTL_OUT(req, &xt, sizeof xt); 1275 if (error) 1276 break; 1277 ++i; 1278 } 1279 } 1280 } 1281 1282 /* 1283 * Make sure we are on the same cpu we were on originally, since 1284 * higher level callers expect this. Also don't pollute caches with 1285 * migrated userland data by (eventually) returning to userland 1286 * on a different cpu. 1287 */ 1288 lwkt_migratecpu(origcpu); 1289 kfree(marker, M_TEMP); 1290 return (error); 1291 } 1292 1293 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1294 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1295 1296 static int 1297 tcp_getcred(SYSCTL_HANDLER_ARGS) 1298 { 1299 struct sockaddr_in addrs[2]; 1300 struct ucred cred0, *cred = NULL; 1301 struct inpcb *inp; 1302 int cpu, origcpu, error; 1303 1304 error = priv_check(req->td, PRIV_ROOT); 1305 if (error != 0) 1306 return (error); 1307 error = SYSCTL_IN(req, addrs, sizeof addrs); 1308 if (error != 0) 1309 return (error); 1310 1311 origcpu = mycpuid; 1312 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1313 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1314 1315 lwkt_migratecpu(cpu); 1316 1317 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1318 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1319 if (inp == NULL || inp->inp_socket == NULL) { 1320 error = ENOENT; 1321 } else if (inp->inp_socket->so_cred != NULL) { 1322 cred0 = *(inp->inp_socket->so_cred); 1323 cred = &cred0; 1324 } 1325 1326 lwkt_migratecpu(origcpu); 1327 1328 if (error) 1329 return (error); 1330 1331 return SYSCTL_OUT(req, cred, sizeof(struct ucred)); 1332 } 1333 1334 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1335 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1336 1337 #ifdef INET6 1338 static int 1339 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1340 { 1341 struct sockaddr_in6 addrs[2]; 1342 struct inpcb *inp; 1343 int error; 1344 1345 error = priv_check(req->td, PRIV_ROOT); 1346 if (error != 0) 1347 return (error); 1348 error = SYSCTL_IN(req, addrs, sizeof addrs); 1349 if (error != 0) 1350 return (error); 1351 crit_enter(); 1352 inp = in6_pcblookup_hash(&tcbinfo[0], 1353 &addrs[1].sin6_addr, addrs[1].sin6_port, 1354 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1355 if (inp == NULL || inp->inp_socket == NULL) { 1356 error = ENOENT; 1357 goto out; 1358 } 1359 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1360 out: 1361 crit_exit(); 1362 return (error); 1363 } 1364 1365 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1366 0, 0, 1367 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1368 #endif 1369 1370 struct netmsg_tcp_notify { 1371 struct netmsg_base base; 1372 inp_notify_t nm_notify; 1373 struct in_addr nm_faddr; 1374 int nm_arg; 1375 }; 1376 1377 static void 1378 tcp_notifyall_oncpu(netmsg_t msg) 1379 { 1380 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1381 int nextcpu; 1382 1383 in_pcbnotifyall(&tcbinfo[mycpuid], nm->nm_faddr, 1384 nm->nm_arg, nm->nm_notify); 1385 1386 nextcpu = mycpuid + 1; 1387 if (nextcpu < netisr_ncpus) 1388 lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg); 1389 else 1390 lwkt_replymsg(&nm->base.lmsg, 0); 1391 } 1392 1393 inp_notify_t 1394 tcp_get_inpnotify(int cmd, const struct sockaddr *sa, 1395 int *arg, struct ip **ip0, int *cpuid) 1396 { 1397 struct ip *ip = *ip0; 1398 struct in_addr faddr; 1399 inp_notify_t notify = tcp_notify; 1400 1401 faddr = ((const struct sockaddr_in *)sa)->sin_addr; 1402 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1403 return NULL; 1404 1405 *arg = inetctlerrmap[cmd]; 1406 if (cmd == PRC_QUENCH) { 1407 notify = tcp_quench; 1408 } else if (icmp_may_rst && 1409 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1410 cmd == PRC_UNREACH_PORT || 1411 cmd == PRC_TIMXCEED_INTRANS) && 1412 ip != NULL) { 1413 notify = tcp_drop_syn_sent; 1414 } else if (cmd == PRC_MSGSIZE) { 1415 const struct icmp *icmp = (const struct icmp *) 1416 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1417 1418 *arg = ntohs(icmp->icmp_nextmtu); 1419 notify = tcp_mtudisc; 1420 } else if (PRC_IS_REDIRECT(cmd)) { 1421 ip = NULL; 1422 notify = in_rtchange; 1423 } else if (cmd == PRC_HOSTDEAD) { 1424 ip = NULL; 1425 } else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1426 return NULL; 1427 } 1428 1429 if (cpuid != NULL) { 1430 if (ip == NULL) { 1431 /* Go through all CPUs */ 1432 *cpuid = ncpus; 1433 } else { 1434 const struct tcphdr *th; 1435 1436 th = (const struct tcphdr *) 1437 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); 1438 *cpuid = tcp_addrcpu(faddr.s_addr, th->th_dport, 1439 ip->ip_src.s_addr, th->th_sport); 1440 } 1441 } 1442 1443 *ip0 = ip; 1444 return notify; 1445 } 1446 1447 void 1448 tcp_ctlinput(netmsg_t msg) 1449 { 1450 int cmd = msg->ctlinput.nm_cmd; 1451 struct sockaddr *sa = msg->ctlinput.nm_arg; 1452 struct ip *ip = msg->ctlinput.nm_extra; 1453 struct in_addr faddr; 1454 inp_notify_t notify; 1455 int arg, cpuid; 1456 1457 notify = tcp_get_inpnotify(cmd, sa, &arg, &ip, &cpuid); 1458 if (notify == NULL) 1459 goto done; 1460 1461 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1462 if (ip != NULL) { 1463 const struct tcphdr *th; 1464 struct inpcb *inp; 1465 1466 if (cpuid != mycpuid) 1467 goto done; 1468 1469 th = (const struct tcphdr *) 1470 ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); 1471 inp = in_pcblookup_hash(&tcbinfo[mycpuid], faddr, th->th_dport, 1472 ip->ip_src, th->th_sport, 0, NULL); 1473 if (inp != NULL && inp->inp_socket != NULL) { 1474 tcp_seq icmpseq = htonl(th->th_seq); 1475 struct tcpcb *tp = intotcpcb(inp); 1476 1477 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1478 SEQ_LT(icmpseq, tp->snd_max)) 1479 notify(inp, arg); 1480 } else { 1481 struct in_conninfo inc; 1482 1483 inc.inc_fport = th->th_dport; 1484 inc.inc_lport = th->th_sport; 1485 inc.inc_faddr = faddr; 1486 inc.inc_laddr = ip->ip_src; 1487 #ifdef INET6 1488 inc.inc_isipv6 = 0; 1489 #endif 1490 syncache_unreach(&inc, th); 1491 } 1492 } else if (msg->ctlinput.nm_direct) { 1493 if (cpuid != ncpus && cpuid != mycpuid) 1494 goto done; 1495 if (mycpuid >= netisr_ncpus) 1496 goto done; 1497 1498 in_pcbnotifyall(&tcbinfo[mycpuid], faddr, arg, notify); 1499 } else { 1500 struct netmsg_tcp_notify *nm; 1501 1502 ASSERT_IN_NETISR(0); 1503 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1504 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1505 0, tcp_notifyall_oncpu); 1506 nm->nm_faddr = faddr; 1507 nm->nm_arg = arg; 1508 nm->nm_notify = notify; 1509 1510 lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg); 1511 } 1512 done: 1513 lwkt_replymsg(&msg->lmsg, 0); 1514 } 1515 1516 #ifdef INET6 1517 1518 void 1519 tcp6_ctlinput(netmsg_t msg) 1520 { 1521 int cmd = msg->ctlinput.nm_cmd; 1522 struct sockaddr *sa = msg->ctlinput.nm_arg; 1523 void *d = msg->ctlinput.nm_extra; 1524 struct tcphdr th; 1525 inp_notify_t notify = tcp_notify; 1526 struct ip6_hdr *ip6; 1527 struct mbuf *m; 1528 struct ip6ctlparam *ip6cp = NULL; 1529 const struct sockaddr_in6 *sa6_src = NULL; 1530 int off; 1531 struct tcp_portonly { 1532 u_int16_t th_sport; 1533 u_int16_t th_dport; 1534 } *thp; 1535 int arg; 1536 1537 if (sa->sa_family != AF_INET6 || 1538 sa->sa_len != sizeof(struct sockaddr_in6)) { 1539 goto out; 1540 } 1541 1542 arg = 0; 1543 if (cmd == PRC_QUENCH) 1544 notify = tcp_quench; 1545 else if (cmd == PRC_MSGSIZE) { 1546 struct ip6ctlparam *ip6cp = d; 1547 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1548 1549 arg = ntohl(icmp6->icmp6_mtu); 1550 notify = tcp_mtudisc; 1551 } else if (!PRC_IS_REDIRECT(cmd) && 1552 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1553 goto out; 1554 } 1555 1556 /* if the parameter is from icmp6, decode it. */ 1557 if (d != NULL) { 1558 ip6cp = (struct ip6ctlparam *)d; 1559 m = ip6cp->ip6c_m; 1560 ip6 = ip6cp->ip6c_ip6; 1561 off = ip6cp->ip6c_off; 1562 sa6_src = ip6cp->ip6c_src; 1563 } else { 1564 m = NULL; 1565 ip6 = NULL; 1566 off = 0; /* fool gcc */ 1567 sa6_src = &sa6_any; 1568 } 1569 1570 if (ip6 != NULL) { 1571 struct in_conninfo inc; 1572 /* 1573 * XXX: We assume that when IPV6 is non NULL, 1574 * M and OFF are valid. 1575 */ 1576 1577 /* check if we can safely examine src and dst ports */ 1578 if (m->m_pkthdr.len < off + sizeof *thp) 1579 goto out; 1580 1581 bzero(&th, sizeof th); 1582 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1583 1584 in6_pcbnotify(&tcbinfo[0], sa, th.th_dport, 1585 (struct sockaddr *)ip6cp->ip6c_src, 1586 th.th_sport, cmd, arg, notify); 1587 1588 inc.inc_fport = th.th_dport; 1589 inc.inc_lport = th.th_sport; 1590 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1591 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1592 inc.inc_isipv6 = 1; 1593 syncache_unreach(&inc, &th); 1594 } else { 1595 in6_pcbnotify(&tcbinfo[0], sa, 0, 1596 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1597 } 1598 out: 1599 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1600 } 1601 1602 #endif 1603 1604 /* 1605 * Following is where TCP initial sequence number generation occurs. 1606 * 1607 * There are two places where we must use initial sequence numbers: 1608 * 1. In SYN-ACK packets. 1609 * 2. In SYN packets. 1610 * 1611 * All ISNs for SYN-ACK packets are generated by the syncache. See 1612 * tcp_syncache.c for details. 1613 * 1614 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1615 * depends on this property. In addition, these ISNs should be 1616 * unguessable so as to prevent connection hijacking. To satisfy 1617 * the requirements of this situation, the algorithm outlined in 1618 * RFC 1948 is used to generate sequence numbers. 1619 * 1620 * Implementation details: 1621 * 1622 * Time is based off the system timer, and is corrected so that it 1623 * increases by one megabyte per second. This allows for proper 1624 * recycling on high speed LANs while still leaving over an hour 1625 * before rollover. 1626 * 1627 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1628 * between seeding of isn_secret. This is normally set to zero, 1629 * as reseeding should not be necessary. 1630 * 1631 */ 1632 1633 #define ISN_BYTES_PER_SECOND 1048576 1634 1635 u_char isn_secret[32]; 1636 int isn_last_reseed; 1637 MD5_CTX isn_ctx; 1638 1639 tcp_seq 1640 tcp_new_isn(struct tcpcb *tp) 1641 { 1642 u_int32_t md5_buffer[4]; 1643 tcp_seq new_isn; 1644 1645 /* Seed if this is the first use, reseed if requested. */ 1646 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1647 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1648 < (u_int)ticks))) { 1649 read_random_unlimited(&isn_secret, sizeof isn_secret); 1650 isn_last_reseed = ticks; 1651 } 1652 1653 /* Compute the md5 hash and return the ISN. */ 1654 MD5Init(&isn_ctx); 1655 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1656 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1657 #ifdef INET6 1658 if (INP_ISIPV6(tp->t_inpcb)) { 1659 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1660 sizeof(struct in6_addr)); 1661 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1662 sizeof(struct in6_addr)); 1663 } else 1664 #endif 1665 { 1666 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1667 sizeof(struct in_addr)); 1668 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1669 sizeof(struct in_addr)); 1670 } 1671 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1672 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1673 new_isn = (tcp_seq) md5_buffer[0]; 1674 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1675 return (new_isn); 1676 } 1677 1678 /* 1679 * When a source quench is received, close congestion window 1680 * to one segment. We will gradually open it again as we proceed. 1681 */ 1682 void 1683 tcp_quench(struct inpcb *inp, int error) 1684 { 1685 struct tcpcb *tp = intotcpcb(inp); 1686 1687 KASSERT(tp != NULL, ("tcp_quench: tp is NULL")); 1688 tp->snd_cwnd = tp->t_maxseg; 1689 tp->snd_wacked = 0; 1690 } 1691 1692 /* 1693 * When a specific ICMP unreachable message is received and the 1694 * connection state is SYN-SENT, drop the connection. This behavior 1695 * is controlled by the icmp_may_rst sysctl. 1696 */ 1697 void 1698 tcp_drop_syn_sent(struct inpcb *inp, int error) 1699 { 1700 struct tcpcb *tp = intotcpcb(inp); 1701 1702 KASSERT(tp != NULL, ("tcp_drop_syn_sent: tp is NULL")); 1703 if (tp->t_state == TCPS_SYN_SENT) 1704 tcp_drop(tp, error); 1705 } 1706 1707 /* 1708 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1709 * based on the new value in the route. Also nudge TCP to send something, 1710 * since we know the packet we just sent was dropped. 1711 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1712 */ 1713 void 1714 tcp_mtudisc(struct inpcb *inp, int mtu) 1715 { 1716 struct tcpcb *tp = intotcpcb(inp); 1717 struct rtentry *rt; 1718 struct socket *so = inp->inp_socket; 1719 int maxopd, mss; 1720 #ifdef INET6 1721 boolean_t isipv6 = INP_ISIPV6(inp); 1722 #else 1723 const boolean_t isipv6 = FALSE; 1724 #endif 1725 1726 KASSERT(tp != NULL, ("tcp_mtudisc: tp is NULL")); 1727 1728 /* 1729 * If no MTU is provided in the ICMP message, use the 1730 * next lower likely value, as specified in RFC 1191. 1731 */ 1732 if (mtu == 0) { 1733 int oldmtu; 1734 1735 oldmtu = tp->t_maxopd + 1736 (isipv6 ? 1737 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1738 sizeof(struct tcpiphdr)); 1739 mtu = ip_next_mtu(oldmtu, 0); 1740 } 1741 1742 if (isipv6) 1743 rt = tcp_rtlookup6(&inp->inp_inc); 1744 else 1745 rt = tcp_rtlookup(&inp->inp_inc); 1746 if (rt != NULL) { 1747 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1748 mtu = rt->rt_rmx.rmx_mtu; 1749 1750 maxopd = mtu - 1751 (isipv6 ? 1752 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1753 sizeof(struct tcpiphdr)); 1754 1755 /* 1756 * XXX - The following conditional probably violates the TCP 1757 * spec. The problem is that, since we don't know the 1758 * other end's MSS, we are supposed to use a conservative 1759 * default. But, if we do that, then MTU discovery will 1760 * never actually take place, because the conservative 1761 * default is much less than the MTUs typically seen 1762 * on the Internet today. For the moment, we'll sweep 1763 * this under the carpet. 1764 * 1765 * The conservative default might not actually be a problem 1766 * if the only case this occurs is when sending an initial 1767 * SYN with options and data to a host we've never talked 1768 * to before. Then, they will reply with an MSS value which 1769 * will get recorded and the new parameters should get 1770 * recomputed. For Further Study. 1771 */ 1772 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1773 maxopd = rt->rt_rmx.rmx_mssopt; 1774 } else 1775 maxopd = mtu - 1776 (isipv6 ? 1777 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1778 sizeof(struct tcpiphdr)); 1779 1780 if (tp->t_maxopd <= maxopd) 1781 return; 1782 tp->t_maxopd = maxopd; 1783 1784 mss = maxopd; 1785 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1786 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1787 mss -= TCPOLEN_TSTAMP_APPA; 1788 1789 /* round down to multiple of MCLBYTES */ 1790 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1791 if (mss > MCLBYTES) 1792 mss &= ~(MCLBYTES - 1); 1793 #else 1794 if (mss > MCLBYTES) 1795 mss = (mss / MCLBYTES) * MCLBYTES; 1796 #endif 1797 1798 if (so->so_snd.ssb_hiwat < mss) 1799 mss = so->so_snd.ssb_hiwat; 1800 1801 tp->t_maxseg = mss; 1802 tp->t_rtttime = 0; 1803 tp->snd_nxt = tp->snd_una; 1804 tcp_output(tp); 1805 tcpstat.tcps_mturesent++; 1806 } 1807 1808 /* 1809 * Look-up the routing entry to the peer of this inpcb. If no route 1810 * is found and it cannot be allocated the return NULL. This routine 1811 * is called by TCP routines that access the rmx structure and by tcp_mss 1812 * to get the interface MTU. 1813 */ 1814 struct rtentry * 1815 tcp_rtlookup(struct in_conninfo *inc) 1816 { 1817 struct route *ro = &inc->inc_route; 1818 1819 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1820 /* No route yet, so try to acquire one */ 1821 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1822 /* 1823 * unused portions of the structure MUST be zero'd 1824 * out because rtalloc() treats it as opaque data 1825 */ 1826 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1827 ro->ro_dst.sa_family = AF_INET; 1828 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1829 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1830 inc->inc_faddr; 1831 rtalloc(ro); 1832 } 1833 } 1834 return (ro->ro_rt); 1835 } 1836 1837 #ifdef INET6 1838 struct rtentry * 1839 tcp_rtlookup6(struct in_conninfo *inc) 1840 { 1841 struct route_in6 *ro6 = &inc->inc6_route; 1842 1843 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1844 /* No route yet, so try to acquire one */ 1845 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1846 /* 1847 * unused portions of the structure MUST be zero'd 1848 * out because rtalloc() treats it as opaque data 1849 */ 1850 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1851 ro6->ro_dst.sin6_family = AF_INET6; 1852 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1853 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1854 rtalloc((struct route *)ro6); 1855 } 1856 } 1857 return (ro6->ro_rt); 1858 } 1859 #endif 1860 1861 #ifdef IPSEC 1862 /* compute ESP/AH header size for TCP, including outer IP header. */ 1863 size_t 1864 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1865 { 1866 struct inpcb *inp; 1867 struct mbuf *m; 1868 size_t hdrsiz; 1869 struct ip *ip; 1870 struct tcphdr *th; 1871 1872 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1873 return (0); 1874 MGETHDR(m, M_NOWAIT, MT_DATA); 1875 if (!m) 1876 return (0); 1877 1878 #ifdef INET6 1879 if (INP_ISIPV6(inp)) { 1880 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1881 1882 th = (struct tcphdr *)(ip6 + 1); 1883 m->m_pkthdr.len = m->m_len = 1884 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1885 tcp_fillheaders(tp, ip6, th, FALSE); 1886 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1887 } else 1888 #endif 1889 { 1890 ip = mtod(m, struct ip *); 1891 th = (struct tcphdr *)(ip + 1); 1892 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1893 tcp_fillheaders(tp, ip, th, FALSE); 1894 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1895 } 1896 1897 m_free(m); 1898 return (hdrsiz); 1899 } 1900 #endif 1901 1902 /* 1903 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1904 * 1905 * This code attempts to calculate the bandwidth-delay product as a 1906 * means of determining the optimal window size to maximize bandwidth, 1907 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1908 * routers. This code also does a fairly good job keeping RTTs in check 1909 * across slow links like modems. We implement an algorithm which is very 1910 * similar (but not meant to be) TCP/Vegas. The code operates on the 1911 * transmitter side of a TCP connection and so only effects the transmit 1912 * side of the connection. 1913 * 1914 * BACKGROUND: TCP makes no provision for the management of buffer space 1915 * at the end points or at the intermediate routers and switches. A TCP 1916 * stream, whether using NewReno or not, will eventually buffer as 1917 * many packets as it is able and the only reason this typically works is 1918 * due to the fairly small default buffers made available for a connection 1919 * (typicaly 16K or 32K). As machines use larger windows and/or window 1920 * scaling it is now fairly easy for even a single TCP connection to blow-out 1921 * all available buffer space not only on the local interface, but on 1922 * intermediate routers and switches as well. NewReno makes a misguided 1923 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1924 * then backing off, then steadily increasing the window again until another 1925 * failure occurs, ad-infinitum. This results in terrible oscillation that 1926 * is only made worse as network loads increase and the idea of intentionally 1927 * blowing out network buffers is, frankly, a terrible way to manage network 1928 * resources. 1929 * 1930 * It is far better to limit the transmit window prior to the failure 1931 * condition being achieved. There are two general ways to do this: First 1932 * you can 'scan' through different transmit window sizes and locate the 1933 * point where the RTT stops increasing, indicating that you have filled the 1934 * pipe, then scan backwards until you note that RTT stops decreasing, then 1935 * repeat ad-infinitum. This method works in principle but has severe 1936 * implementation issues due to RTT variances, timer granularity, and 1937 * instability in the algorithm which can lead to many false positives and 1938 * create oscillations as well as interact badly with other TCP streams 1939 * implementing the same algorithm. 1940 * 1941 * The second method is to limit the window to the bandwidth delay product 1942 * of the link. This is the method we implement. RTT variances and our 1943 * own manipulation of the congestion window, bwnd, can potentially 1944 * destabilize the algorithm. For this reason we have to stabilize the 1945 * elements used to calculate the window. We do this by using the minimum 1946 * observed RTT, the long term average of the observed bandwidth, and 1947 * by adding two segments worth of slop. It isn't perfect but it is able 1948 * to react to changing conditions and gives us a very stable basis on 1949 * which to extend the algorithm. 1950 */ 1951 void 1952 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1953 { 1954 u_long bw; 1955 u_long ibw; 1956 u_long bwnd; 1957 int save_ticks; 1958 int delta_ticks; 1959 1960 /* 1961 * If inflight_enable is disabled in the middle of a tcp connection, 1962 * make sure snd_bwnd is effectively disabled. 1963 */ 1964 if (!tcp_inflight_enable) { 1965 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1966 tp->snd_bandwidth = 0; 1967 return; 1968 } 1969 1970 /* 1971 * Validate the delta time. If a connection is new or has been idle 1972 * a long time we have to reset the bandwidth calculator. 1973 */ 1974 save_ticks = ticks; 1975 cpu_ccfence(); 1976 delta_ticks = save_ticks - tp->t_bw_rtttime; 1977 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1978 tp->t_bw_rtttime = save_ticks; 1979 tp->t_bw_rtseq = ack_seq; 1980 if (tp->snd_bandwidth == 0) 1981 tp->snd_bandwidth = tcp_inflight_start; 1982 return; 1983 } 1984 1985 /* 1986 * A delta of at least 1 tick is required. Waiting 2 ticks will 1987 * result in better (bw) accuracy. More than that and the ramp-up 1988 * will be too slow. 1989 */ 1990 if (delta_ticks == 0 || delta_ticks == 1) 1991 return; 1992 1993 /* 1994 * Sanity check, plus ignore pure window update acks. 1995 */ 1996 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1997 return; 1998 1999 /* 2000 * Figure out the bandwidth. Due to the tick granularity this 2001 * is a very rough number and it MUST be averaged over a fairly 2002 * long period of time. XXX we need to take into account a link 2003 * that is not using all available bandwidth, but for now our 2004 * slop will ramp us up if this case occurs and the bandwidth later 2005 * increases. 2006 */ 2007 ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 2008 tp->t_bw_rtttime = save_ticks; 2009 tp->t_bw_rtseq = ack_seq; 2010 bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4; 2011 2012 tp->snd_bandwidth = bw; 2013 2014 /* 2015 * Calculate the semi-static bandwidth delay product, plus two maximal 2016 * segments. The additional slop puts us squarely in the sweet 2017 * spot and also handles the bandwidth run-up case. Without the 2018 * slop we could be locking ourselves into a lower bandwidth. 2019 * 2020 * At very high speeds the bw calculation can become overly sensitive 2021 * and error prone when delta_ticks is low (e.g. usually 1). To deal 2022 * with the problem the stab must be scaled to the bw. A stab of 50 2023 * (the default) increases the bw for the purposes of the bwnd 2024 * calculation by 5%. 2025 * 2026 * Situations Handled: 2027 * (1) Prevents over-queueing of packets on LANs, especially on 2028 * high speed LANs, allowing larger TCP buffers to be 2029 * specified, and also does a good job preventing 2030 * over-queueing of packets over choke points like modems 2031 * (at least for the transmit side). 2032 * 2033 * (2) Is able to handle changing network loads (bandwidth 2034 * drops so bwnd drops, bandwidth increases so bwnd 2035 * increases). 2036 * 2037 * (3) Theoretically should stabilize in the face of multiple 2038 * connections implementing the same algorithm (this may need 2039 * a little work). 2040 * 2041 * (4) Stability value (defaults to 20 = 2 maximal packets) can 2042 * be adjusted with a sysctl but typically only needs to be on 2043 * very slow connections. A value no smaller then 5 should 2044 * be used, but only reduce this default if you have no other 2045 * choice. 2046 */ 2047 2048 #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt) 2049 bw += bw * tcp_inflight_stab / 1000; 2050 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 2051 (int)tp->t_maxseg * 2; 2052 #undef USERTT 2053 2054 if (tcp_inflight_debug > 0) { 2055 static int ltime; 2056 if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) { 2057 ltime = save_ticks; 2058 kprintf("%p ibw %ld bw %ld rttvar %d srtt %d " 2059 "bwnd %ld delta %d snd_win %ld\n", 2060 tp, ibw, bw, tp->t_rttvar, tp->t_srtt, 2061 bwnd, delta_ticks, tp->snd_wnd); 2062 } 2063 } 2064 if ((long)bwnd < tcp_inflight_min) 2065 bwnd = tcp_inflight_min; 2066 if (bwnd > tcp_inflight_max) 2067 bwnd = tcp_inflight_max; 2068 if ((long)bwnd < tp->t_maxseg * 2) 2069 bwnd = tp->t_maxseg * 2; 2070 tp->snd_bwnd = bwnd; 2071 } 2072 2073 static void 2074 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs) 2075 { 2076 struct rtentry *rt; 2077 struct inpcb *inp = tp->t_inpcb; 2078 #ifdef INET6 2079 boolean_t isipv6 = INP_ISIPV6(inp); 2080 #else 2081 const boolean_t isipv6 = FALSE; 2082 #endif 2083 2084 /* XXX */ 2085 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT) 2086 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 2087 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT) 2088 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 2089 2090 if (isipv6) 2091 rt = tcp_rtlookup6(&inp->inp_inc); 2092 else 2093 rt = tcp_rtlookup(&inp->inp_inc); 2094 if (rt == NULL || 2095 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT || 2096 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) { 2097 *maxsegs = tcp_iw_maxsegs; 2098 *capsegs = tcp_iw_capsegs; 2099 return; 2100 } 2101 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs; 2102 *capsegs = rt->rt_rmx.rmx_iwcapsegs; 2103 } 2104 2105 u_long 2106 tcp_initial_window(struct tcpcb *tp) 2107 { 2108 if (tcp_do_rfc3390) { 2109 /* 2110 * RFC3390: 2111 * "If the SYN or SYN/ACK is lost, the initial window 2112 * used by a sender after a correctly transmitted SYN 2113 * MUST be one segment consisting of MSS bytes." 2114 * 2115 * However, we do something a little bit more aggressive 2116 * then RFC3390 here: 2117 * - Only if time spent in the SYN or SYN|ACK retransmition 2118 * >= 3 seconds, the IW is reduced. We do this mainly 2119 * because when RFC3390 is published, the initial RTO is 2120 * still 3 seconds (the threshold we test here), while 2121 * after RFC6298, the initial RTO is 1 second. This 2122 * behaviour probably still falls within the spirit of 2123 * RFC3390. 2124 * - When IW is reduced, 2*MSS is used instead of 1*MSS. 2125 * Mainly to avoid sender and receiver deadlock until 2126 * delayed ACK timer expires. And even RFC2581 does not 2127 * try to reduce IW upon SYN or SYN|ACK retransmition 2128 * timeout. 2129 * 2130 * See also: 2131 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03 2132 */ 2133 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) { 2134 return (2 * tp->t_maxseg); 2135 } else { 2136 u_long maxsegs, capsegs; 2137 2138 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs); 2139 return min(maxsegs * tp->t_maxseg, 2140 max(2 * tp->t_maxseg, capsegs * 1460)); 2141 } 2142 } else { 2143 /* 2144 * Even RFC2581 (back to 1999) allows 2*SMSS IW. 2145 * 2146 * Mainly to avoid sender and receiver deadlock 2147 * until delayed ACK timer expires. 2148 */ 2149 return (2 * tp->t_maxseg); 2150 } 2151 } 2152 2153 #ifdef TCP_SIGNATURE 2154 /* 2155 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2156 * 2157 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2158 * When called from tcp_input(), we can be sure that th_sum has been 2159 * zeroed out and verified already. 2160 * 2161 * Return 0 if successful, otherwise return -1. 2162 * 2163 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2164 * search with the destination IP address, and a 'magic SPI' to be 2165 * determined by the application. This is hardcoded elsewhere to 1179 2166 * right now. Another branch of this code exists which uses the SPD to 2167 * specify per-application flows but it is unstable. 2168 */ 2169 int 2170 tcpsignature_compute( 2171 struct mbuf *m, /* mbuf chain */ 2172 int len, /* length of TCP data */ 2173 int optlen, /* length of TCP options */ 2174 u_char *buf, /* storage for MD5 digest */ 2175 u_int direction) /* direction of flow */ 2176 { 2177 struct ippseudo ippseudo; 2178 MD5_CTX ctx; 2179 int doff; 2180 struct ip *ip; 2181 struct ipovly *ipovly; 2182 struct secasvar *sav; 2183 struct tcphdr *th; 2184 #ifdef INET6 2185 struct ip6_hdr *ip6; 2186 struct in6_addr in6; 2187 uint32_t plen; 2188 uint16_t nhdr; 2189 #endif /* INET6 */ 2190 u_short savecsum; 2191 2192 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 2193 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 2194 /* 2195 * Extract the destination from the IP header in the mbuf. 2196 */ 2197 ip = mtod(m, struct ip *); 2198 #ifdef INET6 2199 ip6 = NULL; /* Make the compiler happy. */ 2200 #endif /* INET6 */ 2201 /* 2202 * Look up an SADB entry which matches the address found in 2203 * the segment. 2204 */ 2205 switch (IP_VHL_V(ip->ip_vhl)) { 2206 case IPVERSION: 2207 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2208 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2209 break; 2210 #ifdef INET6 2211 case (IPV6_VERSION >> 4): 2212 ip6 = mtod(m, struct ip6_hdr *); 2213 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2214 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2215 break; 2216 #endif /* INET6 */ 2217 default: 2218 return (EINVAL); 2219 /* NOTREACHED */ 2220 break; 2221 } 2222 if (sav == NULL) { 2223 kprintf("%s: SADB lookup failed\n", __func__); 2224 return (EINVAL); 2225 } 2226 MD5Init(&ctx); 2227 2228 /* 2229 * Step 1: Update MD5 hash with IP pseudo-header. 2230 * 2231 * XXX The ippseudo header MUST be digested in network byte order, 2232 * or else we'll fail the regression test. Assume all fields we've 2233 * been doing arithmetic on have been in host byte order. 2234 * XXX One cannot depend on ipovly->ih_len here. When called from 2235 * tcp_output(), the underlying ip_len member has not yet been set. 2236 */ 2237 switch (IP_VHL_V(ip->ip_vhl)) { 2238 case IPVERSION: 2239 ipovly = (struct ipovly *)ip; 2240 ippseudo.ippseudo_src = ipovly->ih_src; 2241 ippseudo.ippseudo_dst = ipovly->ih_dst; 2242 ippseudo.ippseudo_pad = 0; 2243 ippseudo.ippseudo_p = IPPROTO_TCP; 2244 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2245 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2246 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2247 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2248 break; 2249 #ifdef INET6 2250 /* 2251 * RFC 2385, 2.0 Proposal 2252 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2253 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2254 * extended next header value (to form 32 bits), and 32-bit segment 2255 * length. 2256 * Note: Upper-Layer Packet Length comes before Next Header. 2257 */ 2258 case (IPV6_VERSION >> 4): 2259 in6 = ip6->ip6_src; 2260 in6_clearscope(&in6); 2261 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2262 in6 = ip6->ip6_dst; 2263 in6_clearscope(&in6); 2264 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2265 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2266 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2267 nhdr = 0; 2268 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2269 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2270 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2271 nhdr = IPPROTO_TCP; 2272 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2273 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2274 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2275 break; 2276 #endif /* INET6 */ 2277 default: 2278 return (EINVAL); 2279 /* NOTREACHED */ 2280 break; 2281 } 2282 /* 2283 * Step 2: Update MD5 hash with TCP header, excluding options. 2284 * The TCP checksum must be set to zero. 2285 */ 2286 savecsum = th->th_sum; 2287 th->th_sum = 0; 2288 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2289 th->th_sum = savecsum; 2290 /* 2291 * Step 3: Update MD5 hash with TCP segment data. 2292 * Use m_apply() to avoid an early m_pullup(). 2293 */ 2294 if (len > 0) 2295 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2296 /* 2297 * Step 4: Update MD5 hash with shared secret. 2298 */ 2299 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2300 MD5Final(buf, &ctx); 2301 key_sa_recordxfer(sav, m); 2302 key_freesav(sav); 2303 return (0); 2304 } 2305 2306 int 2307 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2308 { 2309 2310 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2311 return (0); 2312 } 2313 #endif /* TCP_SIGNATURE */ 2314 2315 static void 2316 tcp_drop_sysctl_dispatch(netmsg_t nmsg) 2317 { 2318 struct lwkt_msg *lmsg = &nmsg->lmsg; 2319 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2320 struct sockaddr_storage *addrs = lmsg->u.ms_resultp; 2321 int error; 2322 struct sockaddr_in *fin, *lin; 2323 #ifdef INET6 2324 struct sockaddr_in6 *fin6, *lin6; 2325 struct in6_addr f6, l6; 2326 #endif 2327 struct inpcb *inp; 2328 2329 switch (addrs[0].ss_family) { 2330 #ifdef INET6 2331 case AF_INET6: 2332 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2333 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2334 error = in6_embedscope(&f6, fin6, NULL, NULL); 2335 if (error) 2336 goto done; 2337 error = in6_embedscope(&l6, lin6, NULL, NULL); 2338 if (error) 2339 goto done; 2340 inp = in6_pcblookup_hash(&tcbinfo[mycpuid], &f6, 2341 fin6->sin6_port, &l6, lin6->sin6_port, FALSE, NULL); 2342 break; 2343 #endif 2344 #ifdef INET 2345 case AF_INET: 2346 fin = (struct sockaddr_in *)&addrs[0]; 2347 lin = (struct sockaddr_in *)&addrs[1]; 2348 inp = in_pcblookup_hash(&tcbinfo[mycpuid], fin->sin_addr, 2349 fin->sin_port, lin->sin_addr, lin->sin_port, FALSE, NULL); 2350 break; 2351 #endif 2352 default: 2353 /* 2354 * Must not reach here, since the address family was 2355 * checked in sysctl handler. 2356 */ 2357 panic("unknown address family %d", addrs[0].ss_family); 2358 } 2359 if (inp != NULL) { 2360 struct tcpcb *tp = intotcpcb(inp); 2361 2362 KASSERT((inp->inp_flags & INP_WILDCARD) == 0, 2363 ("in wildcard hash")); 2364 KASSERT(tp != NULL, ("tcp_drop_sysctl_dispatch: tp is NULL")); 2365 KASSERT((tp->t_flags & TF_LISTEN) == 0, ("listen socket")); 2366 tcp_drop(tp, ECONNABORTED); 2367 error = 0; 2368 } else { 2369 error = ESRCH; 2370 } 2371 #ifdef INET6 2372 done: 2373 #endif 2374 lwkt_replymsg(lmsg, error); 2375 } 2376 2377 static int 2378 sysctl_tcp_drop(SYSCTL_HANDLER_ARGS) 2379 { 2380 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2381 struct sockaddr_storage addrs[2]; 2382 struct sockaddr_in *fin, *lin; 2383 #ifdef INET6 2384 struct sockaddr_in6 *fin6, *lin6; 2385 #endif 2386 struct netmsg_base nmsg; 2387 struct lwkt_msg *lmsg = &nmsg.lmsg; 2388 struct lwkt_port *port = NULL; 2389 int error; 2390 2391 fin = lin = NULL; 2392 #ifdef INET6 2393 fin6 = lin6 = NULL; 2394 #endif 2395 error = 0; 2396 2397 if (req->oldptr != NULL || req->oldlen != 0) 2398 return (EINVAL); 2399 if (req->newptr == NULL) 2400 return (EPERM); 2401 if (req->newlen < sizeof(addrs)) 2402 return (ENOMEM); 2403 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2404 if (error) 2405 return (error); 2406 2407 switch (addrs[0].ss_family) { 2408 #ifdef INET6 2409 case AF_INET6: 2410 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2411 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2412 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2413 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2414 return (EINVAL); 2415 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr) || 2416 IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2417 return (EADDRNOTAVAIL); 2418 #if 0 2419 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2420 if (error) 2421 return (error); 2422 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2423 if (error) 2424 return (error); 2425 #endif 2426 port = tcp6_addrport(); 2427 break; 2428 #endif 2429 #ifdef INET 2430 case AF_INET: 2431 fin = (struct sockaddr_in *)&addrs[0]; 2432 lin = (struct sockaddr_in *)&addrs[1]; 2433 if (fin->sin_len != sizeof(struct sockaddr_in) || 2434 lin->sin_len != sizeof(struct sockaddr_in)) 2435 return (EINVAL); 2436 port = tcp_addrport(fin->sin_addr.s_addr, fin->sin_port, 2437 lin->sin_addr.s_addr, lin->sin_port); 2438 break; 2439 #endif 2440 default: 2441 return (EINVAL); 2442 } 2443 2444 netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0, 2445 tcp_drop_sysctl_dispatch); 2446 lmsg->u.ms_resultp = addrs; 2447 return lwkt_domsg(port, lmsg, 0); 2448 } 2449 2450 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, drop, 2451 CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2452 0, sysctl_tcp_drop, "", "Drop TCP connection"); 2453 2454 static int 2455 sysctl_tcps_count(SYSCTL_HANDLER_ARGS) 2456 { 2457 u_long state_count[TCP_NSTATES]; 2458 int cpu; 2459 2460 memset(state_count, 0, sizeof(state_count)); 2461 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 2462 int i; 2463 2464 for (i = 0; i < TCP_NSTATES; ++i) 2465 state_count[i] += tcpstate_count[cpu].tcps_count[i]; 2466 } 2467 2468 return sysctl_handle_opaque(oidp, state_count, sizeof(state_count), req); 2469 } 2470 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, state_count, 2471 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 2472 sysctl_tcps_count, "LU", "TCP connection counts by state"); 2473 2474 void 2475 tcp_pcbport_create(struct tcpcb *tp) 2476 { 2477 int cpu; 2478 2479 KASSERT((tp->t_flags & TF_LISTEN) && tp->t_state == TCPS_LISTEN, 2480 ("not a listen tcpcb")); 2481 2482 KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache was created")); 2483 tp->t_pcbport = kmalloc_cachealign( 2484 sizeof(struct tcp_pcbport) * netisr_ncpus, M_PCB, M_WAITOK); 2485 2486 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 2487 struct inpcbport *phd; 2488 2489 phd = &tp->t_pcbport[cpu].t_phd; 2490 LIST_INIT(&phd->phd_pcblist); 2491 /* Though, not used ... */ 2492 phd->phd_port = tp->t_inpcb->inp_lport; 2493 } 2494 } 2495 2496 void 2497 tcp_pcbport_merge_oncpu(struct tcpcb *tp) 2498 { 2499 struct inpcbport *phd; 2500 struct inpcb *inp; 2501 int cpu = mycpuid; 2502 2503 KASSERT(cpu < netisr_ncpus, ("invalid cpu%d", cpu)); 2504 phd = &tp->t_pcbport[cpu].t_phd; 2505 2506 while ((inp = LIST_FIRST(&phd->phd_pcblist)) != NULL) { 2507 KASSERT(inp->inp_phd == phd && inp->inp_porthash == NULL, 2508 ("not on tcpcb port cache")); 2509 LIST_REMOVE(inp, inp_portlist); 2510 in_pcbinsporthash_lport(inp); 2511 KASSERT(inp->inp_phd == tp->t_inpcb->inp_phd && 2512 inp->inp_porthash == tp->t_inpcb->inp_porthash, 2513 ("tcpcb port cache merge failed")); 2514 } 2515 } 2516 2517 void 2518 tcp_pcbport_destroy(struct tcpcb *tp) 2519 { 2520 #ifdef INVARIANTS 2521 int cpu; 2522 2523 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 2524 KASSERT(LIST_EMPTY(&tp->t_pcbport[cpu].t_phd.phd_pcblist), 2525 ("tcpcb port cache is not empty")); 2526 } 2527 #endif 2528 kfree(tp->t_pcbport, M_PCB); 2529 tp->t_pcbport = NULL; 2530 } 2531