1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_kern_tls.h" 41 #include "opt_tcpdebug.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/arb.h> 46 #include <sys/callout.h> 47 #include <sys/eventhandler.h> 48 #ifdef TCP_HHOOK 49 #include <sys/hhook.h> 50 #endif 51 #include <sys/kernel.h> 52 #ifdef TCP_HHOOK 53 #include <sys/khelp.h> 54 #endif 55 #ifdef KERN_TLS 56 #include <sys/ktls.h> 57 #endif 58 #include <sys/qmath.h> 59 #include <sys/stats.h> 60 #include <sys/sysctl.h> 61 #include <sys/jail.h> 62 #include <sys/malloc.h> 63 #include <sys/refcount.h> 64 #include <sys/mbuf.h> 65 #ifdef INET6 66 #include <sys/domain.h> 67 #endif 68 #include <sys/priv.h> 69 #include <sys/proc.h> 70 #include <sys/sdt.h> 71 #include <sys/socket.h> 72 #include <sys/socketvar.h> 73 #include <sys/protosw.h> 74 #include <sys/random.h> 75 76 #include <vm/uma.h> 77 78 #include <net/route.h> 79 #include <net/route/nhop.h> 80 #include <net/if.h> 81 #include <net/if_var.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_fib.h> 86 #include <netinet/in_kdtrace.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/ip_icmp.h> 92 #include <netinet/ip_var.h> 93 #ifdef INET6 94 #include <netinet/icmp6.h> 95 #include <netinet/ip6.h> 96 #include <netinet6/in6_fib.h> 97 #include <netinet6/in6_pcb.h> 98 #include <netinet6/ip6_var.h> 99 #include <netinet6/scope6_var.h> 100 #include <netinet6/nd6.h> 101 #endif 102 103 #include <netinet/tcp.h> 104 #include <netinet/tcp_fsm.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 #include <netinet/tcp_log_buf.h> 109 #include <netinet/tcp_syncache.h> 110 #include <netinet/tcp_hpts.h> 111 #include <netinet/cc/cc.h> 112 #ifdef INET6 113 #include <netinet6/tcp6_var.h> 114 #endif 115 #include <netinet/tcpip.h> 116 #include <netinet/tcp_fastopen.h> 117 #ifdef TCPPCAP 118 #include <netinet/tcp_pcap.h> 119 #endif 120 #ifdef TCPDEBUG 121 #include <netinet/tcp_debug.h> 122 #endif 123 #ifdef INET6 124 #include <netinet6/ip6protosw.h> 125 #endif 126 #ifdef TCP_OFFLOAD 127 #include <netinet/tcp_offload.h> 128 #endif 129 #include <netinet/udp.h> 130 #include <netinet/udp_var.h> 131 132 #include <netipsec/ipsec_support.h> 133 134 #include <machine/in_cksum.h> 135 #include <crypto/siphash/siphash.h> 136 137 #include <security/mac/mac_framework.h> 138 139 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 140 #ifdef INET6 141 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 142 #endif 143 144 #ifdef NETFLIX_EXP_DETECTION 145 /* Sack attack detection thresholds and such */ 146 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 147 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 148 "Sack Attack detection thresholds"); 149 int32_t tcp_force_detection = 0; 150 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 151 CTLFLAG_RW, 152 &tcp_force_detection, 0, 153 "Do we force detection even if the INP has it off?"); 154 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 155 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 156 CTLFLAG_RW, 157 &tcp_sack_to_ack_thresh, 700, 158 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 159 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 160 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 161 CTLFLAG_RW, 162 &tcp_sack_to_move_thresh, 600, 163 "Percentage of sack moves we must see above (10.1 percent is 101)"); 164 int32_t tcp_restoral_thresh = 650; /* 65 % (sack:2:ack -5%) */ 165 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 166 CTLFLAG_RW, 167 &tcp_restoral_thresh, 550, 168 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 169 int32_t tcp_sad_decay_val = 800; 170 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 171 CTLFLAG_RW, 172 &tcp_sad_decay_val, 800, 173 "The decay percentage (10.1 percent equals 101 )"); 174 int32_t tcp_map_minimum = 500; 175 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 176 CTLFLAG_RW, 177 &tcp_map_minimum, 500, 178 "Number of Map enteries before we start detection"); 179 int32_t tcp_attack_on_turns_on_logging = 0; 180 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, attacks_logged, 181 CTLFLAG_RW, 182 &tcp_attack_on_turns_on_logging, 0, 183 "When we have a positive hit on attack, do we turn on logging?"); 184 int32_t tcp_sad_pacing_interval = 2000; 185 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 186 CTLFLAG_RW, 187 &tcp_sad_pacing_interval, 2000, 188 "What is the minimum pacing interval for a classified attacker?"); 189 190 int32_t tcp_sad_low_pps = 100; 191 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 192 CTLFLAG_RW, 193 &tcp_sad_low_pps, 100, 194 "What is the input pps that below which we do not decay?"); 195 #endif 196 uint32_t tcp_ack_war_time_window = 1000; 197 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 198 CTLFLAG_RW, 199 &tcp_ack_war_time_window, 1000, 200 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 201 uint32_t tcp_ack_war_cnt = 5; 202 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 203 CTLFLAG_RW, 204 &tcp_ack_war_cnt, 5, 205 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 206 207 struct rwlock tcp_function_lock; 208 209 static int 210 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 211 { 212 int error, new; 213 214 new = V_tcp_mssdflt; 215 error = sysctl_handle_int(oidp, &new, 0, req); 216 if (error == 0 && req->newptr) { 217 if (new < TCP_MINMSS) 218 error = EINVAL; 219 else 220 V_tcp_mssdflt = new; 221 } 222 return (error); 223 } 224 225 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 227 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 228 "Default TCP Maximum Segment Size"); 229 230 #ifdef INET6 231 static int 232 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 233 { 234 int error, new; 235 236 new = V_tcp_v6mssdflt; 237 error = sysctl_handle_int(oidp, &new, 0, req); 238 if (error == 0 && req->newptr) { 239 if (new < TCP_MINMSS) 240 error = EINVAL; 241 else 242 V_tcp_v6mssdflt = new; 243 } 244 return (error); 245 } 246 247 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 248 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 249 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 250 "Default TCP Maximum Segment Size for IPv6"); 251 #endif /* INET6 */ 252 253 /* 254 * Minimum MSS we accept and use. This prevents DoS attacks where 255 * we are forced to a ridiculous low MSS like 20 and send hundreds 256 * of packets instead of one. The effect scales with the available 257 * bandwidth and quickly saturates the CPU and network interface 258 * with packet generation and sending. Set to zero to disable MINMSS 259 * checking. This setting prevents us from sending too small packets. 260 */ 261 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 263 &VNET_NAME(tcp_minmss), 0, 264 "Minimum TCP Maximum Segment Size"); 265 266 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 267 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 268 &VNET_NAME(tcp_do_rfc1323), 0, 269 "Enable rfc1323 (high performance TCP) extensions"); 270 271 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 0; 272 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 273 &VNET_NAME(tcp_tolerate_missing_ts), 0, 274 "Tolerate missing TCP timestamps"); 275 276 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 277 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 278 &VNET_NAME(tcp_ts_offset_per_conn), 0, 279 "Initialize TCP timestamps per connection instead of per host pair"); 280 281 /* How many connections are pacing */ 282 static volatile uint32_t number_of_tcp_connections_pacing = 0; 283 static uint32_t shadow_num_connections = 0; 284 285 static int tcp_pacing_limit = 10000; 286 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 287 &tcp_pacing_limit, 1000, 288 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 289 290 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 291 &shadow_num_connections, 0, "Number of TCP connections being paced"); 292 293 static int tcp_log_debug = 0; 294 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 295 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 296 297 static int tcp_tcbhashsize; 298 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 299 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 300 301 static int do_tcpdrain = 1; 302 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 303 "Enable tcp_drain routine for extra help when low on mbufs"); 304 305 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 306 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 307 308 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 309 #define V_icmp_may_rst VNET(icmp_may_rst) 310 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 311 &VNET_NAME(icmp_may_rst), 0, 312 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 313 314 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 315 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 316 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 317 &VNET_NAME(tcp_isn_reseed_interval), 0, 318 "Seconds between reseeding of ISN secret"); 319 320 static int tcp_soreceive_stream; 321 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 322 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 323 324 VNET_DEFINE(uma_zone_t, sack_hole_zone); 325 #define V_sack_hole_zone VNET(sack_hole_zone) 326 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 327 static int 328 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 329 { 330 int error; 331 uint32_t new; 332 333 new = V_tcp_map_entries_limit; 334 error = sysctl_handle_int(oidp, &new, 0, req); 335 if (error == 0 && req->newptr) { 336 /* only allow "0" and value > minimum */ 337 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 338 error = EINVAL; 339 else 340 V_tcp_map_entries_limit = new; 341 } 342 return (error); 343 } 344 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 345 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 346 &VNET_NAME(tcp_map_entries_limit), 0, 347 &sysctl_net_inet_tcp_map_limit_check, "IU", 348 "Total sendmap entries limit"); 349 350 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 351 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 352 &VNET_NAME(tcp_map_split_limit), 0, 353 "Total sendmap split entries limit"); 354 355 #ifdef TCP_HHOOK 356 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 357 #endif 358 359 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 360 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 361 #define V_ts_offset_secret VNET(ts_offset_secret) 362 363 static int tcp_default_fb_init(struct tcpcb *tp); 364 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 365 static int tcp_default_handoff_ok(struct tcpcb *tp); 366 static struct inpcb *tcp_notify(struct inpcb *, int); 367 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 368 static void tcp_mtudisc(struct inpcb *, int); 369 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 370 void *ip4hdr, const void *ip6hdr); 371 372 static struct tcp_function_block tcp_def_funcblk = { 373 .tfb_tcp_block_name = "freebsd", 374 .tfb_tcp_output = tcp_output, 375 .tfb_tcp_do_segment = tcp_do_segment, 376 .tfb_tcp_ctloutput = tcp_default_ctloutput, 377 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 378 .tfb_tcp_fb_init = tcp_default_fb_init, 379 .tfb_tcp_fb_fini = tcp_default_fb_fini, 380 }; 381 382 static int tcp_fb_cnt = 0; 383 struct tcp_funchead t_functions; 384 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 385 386 static struct tcp_function_block * 387 find_tcp_functions_locked(struct tcp_function_set *fs) 388 { 389 struct tcp_function *f; 390 struct tcp_function_block *blk=NULL; 391 392 TAILQ_FOREACH(f, &t_functions, tf_next) { 393 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 394 blk = f->tf_fb; 395 break; 396 } 397 } 398 return(blk); 399 } 400 401 static struct tcp_function_block * 402 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 403 { 404 struct tcp_function_block *rblk=NULL; 405 struct tcp_function *f; 406 407 TAILQ_FOREACH(f, &t_functions, tf_next) { 408 if (f->tf_fb == blk) { 409 rblk = blk; 410 if (s) { 411 *s = f; 412 } 413 break; 414 } 415 } 416 return (rblk); 417 } 418 419 struct tcp_function_block * 420 find_and_ref_tcp_functions(struct tcp_function_set *fs) 421 { 422 struct tcp_function_block *blk; 423 424 rw_rlock(&tcp_function_lock); 425 blk = find_tcp_functions_locked(fs); 426 if (blk) 427 refcount_acquire(&blk->tfb_refcnt); 428 rw_runlock(&tcp_function_lock); 429 return(blk); 430 } 431 432 struct tcp_function_block * 433 find_and_ref_tcp_fb(struct tcp_function_block *blk) 434 { 435 struct tcp_function_block *rblk; 436 437 rw_rlock(&tcp_function_lock); 438 rblk = find_tcp_fb_locked(blk, NULL); 439 if (rblk) 440 refcount_acquire(&rblk->tfb_refcnt); 441 rw_runlock(&tcp_function_lock); 442 return(rblk); 443 } 444 445 static struct tcp_function_block * 446 find_and_ref_tcp_default_fb(void) 447 { 448 struct tcp_function_block *rblk; 449 450 rw_rlock(&tcp_function_lock); 451 rblk = tcp_func_set_ptr; 452 refcount_acquire(&rblk->tfb_refcnt); 453 rw_runlock(&tcp_function_lock); 454 return (rblk); 455 } 456 457 void 458 tcp_switch_back_to_default(struct tcpcb *tp) 459 { 460 struct tcp_function_block *tfb; 461 462 KASSERT(tp->t_fb != &tcp_def_funcblk, 463 ("%s: called by the built-in default stack", __func__)); 464 465 /* 466 * Release the old stack. This function will either find a new one 467 * or panic. 468 */ 469 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 470 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 471 refcount_release(&tp->t_fb->tfb_refcnt); 472 473 /* 474 * Now, we'll find a new function block to use. 475 * Start by trying the current user-selected 476 * default, unless this stack is the user-selected 477 * default. 478 */ 479 tfb = find_and_ref_tcp_default_fb(); 480 if (tfb == tp->t_fb) { 481 refcount_release(&tfb->tfb_refcnt); 482 tfb = NULL; 483 } 484 /* Does the stack accept this connection? */ 485 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 486 (*tfb->tfb_tcp_handoff_ok)(tp)) { 487 refcount_release(&tfb->tfb_refcnt); 488 tfb = NULL; 489 } 490 /* Try to use that stack. */ 491 if (tfb != NULL) { 492 /* Initialize the new stack. If it succeeds, we are done. */ 493 tp->t_fb = tfb; 494 if (tp->t_fb->tfb_tcp_fb_init == NULL || 495 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 496 return; 497 498 /* 499 * Initialization failed. Release the reference count on 500 * the stack. 501 */ 502 refcount_release(&tfb->tfb_refcnt); 503 } 504 505 /* 506 * If that wasn't feasible, use the built-in default 507 * stack which is not allowed to reject anyone. 508 */ 509 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 510 if (tfb == NULL) { 511 /* there always should be a default */ 512 panic("Can't refer to tcp_def_funcblk"); 513 } 514 if (tfb->tfb_tcp_handoff_ok != NULL) { 515 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 516 /* The default stack cannot say no */ 517 panic("Default stack rejects a new session?"); 518 } 519 } 520 tp->t_fb = tfb; 521 if (tp->t_fb->tfb_tcp_fb_init != NULL && 522 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 523 /* The default stack cannot fail */ 524 panic("Default stack initialization failed"); 525 } 526 } 527 528 static void 529 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 530 const struct sockaddr *sa, void *ctx) 531 { 532 struct ip *iph; 533 #ifdef INET6 534 struct ip6_hdr *ip6; 535 #endif 536 struct udphdr *uh; 537 struct tcphdr *th; 538 int thlen; 539 uint16_t port; 540 541 TCPSTAT_INC(tcps_tunneled_pkts); 542 if ((m->m_flags & M_PKTHDR) == 0) { 543 /* Can't handle one that is not a pkt hdr */ 544 TCPSTAT_INC(tcps_tunneled_errs); 545 goto out; 546 } 547 thlen = sizeof(struct tcphdr); 548 if (m->m_len < off + sizeof(struct udphdr) + thlen && 549 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 550 TCPSTAT_INC(tcps_tunneled_errs); 551 goto out; 552 } 553 iph = mtod(m, struct ip *); 554 uh = (struct udphdr *)((caddr_t)iph + off); 555 th = (struct tcphdr *)(uh + 1); 556 thlen = th->th_off << 2; 557 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 558 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 559 if (m == NULL) { 560 TCPSTAT_INC(tcps_tunneled_errs); 561 goto out; 562 } else { 563 iph = mtod(m, struct ip *); 564 uh = (struct udphdr *)((caddr_t)iph + off); 565 th = (struct tcphdr *)(uh + 1); 566 } 567 } 568 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 569 bcopy(th, uh, m->m_len - off); 570 m->m_len -= sizeof(struct udphdr); 571 m->m_pkthdr.len -= sizeof(struct udphdr); 572 /* 573 * We use the same algorithm for 574 * both UDP and TCP for c-sum. So 575 * the code in tcp_input will skip 576 * the checksum. So we do nothing 577 * with the flag (m->m_pkthdr.csum_flags). 578 */ 579 switch (iph->ip_v) { 580 #ifdef INET 581 case IPVERSION: 582 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 583 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 584 break; 585 #endif 586 #ifdef INET6 587 case IPV6_VERSION >> 4: 588 ip6 = mtod(m, struct ip6_hdr *); 589 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 590 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 591 break; 592 #endif 593 default: 594 goto out; 595 break; 596 } 597 return; 598 out: 599 m_freem(m); 600 } 601 602 static int 603 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 604 { 605 int error=ENOENT; 606 struct tcp_function_set fs; 607 struct tcp_function_block *blk; 608 609 memset(&fs, 0, sizeof(fs)); 610 rw_rlock(&tcp_function_lock); 611 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 612 if (blk) { 613 /* Found him */ 614 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 615 fs.pcbcnt = blk->tfb_refcnt; 616 } 617 rw_runlock(&tcp_function_lock); 618 error = sysctl_handle_string(oidp, fs.function_set_name, 619 sizeof(fs.function_set_name), req); 620 621 /* Check for error or no change */ 622 if (error != 0 || req->newptr == NULL) 623 return(error); 624 625 rw_wlock(&tcp_function_lock); 626 blk = find_tcp_functions_locked(&fs); 627 if ((blk == NULL) || 628 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 629 error = ENOENT; 630 goto done; 631 } 632 tcp_func_set_ptr = blk; 633 done: 634 rw_wunlock(&tcp_function_lock); 635 return (error); 636 } 637 638 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 639 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 640 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 641 "Set/get the default TCP functions"); 642 643 static int 644 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 645 { 646 int error, cnt, linesz; 647 struct tcp_function *f; 648 char *buffer, *cp; 649 size_t bufsz, outsz; 650 bool alias; 651 652 cnt = 0; 653 rw_rlock(&tcp_function_lock); 654 TAILQ_FOREACH(f, &t_functions, tf_next) { 655 cnt++; 656 } 657 rw_runlock(&tcp_function_lock); 658 659 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 660 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 661 662 error = 0; 663 cp = buffer; 664 665 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 666 "Alias", "PCB count"); 667 cp += linesz; 668 bufsz -= linesz; 669 outsz = linesz; 670 671 rw_rlock(&tcp_function_lock); 672 TAILQ_FOREACH(f, &t_functions, tf_next) { 673 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 674 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 675 f->tf_fb->tfb_tcp_block_name, 676 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 677 alias ? f->tf_name : "-", 678 f->tf_fb->tfb_refcnt); 679 if (linesz >= bufsz) { 680 error = EOVERFLOW; 681 break; 682 } 683 cp += linesz; 684 bufsz -= linesz; 685 outsz += linesz; 686 } 687 rw_runlock(&tcp_function_lock); 688 if (error == 0) 689 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 690 free(buffer, M_TEMP); 691 return (error); 692 } 693 694 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 695 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 696 NULL, 0, sysctl_net_inet_list_available, "A", 697 "list available TCP Function sets"); 698 699 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 700 701 #ifdef INET 702 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 703 #define V_udp4_tun_socket VNET(udp4_tun_socket) 704 #endif 705 #ifdef INET6 706 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 707 #define V_udp6_tun_socket VNET(udp6_tun_socket) 708 #endif 709 710 static void 711 tcp_over_udp_stop(void) 712 { 713 /* 714 * This function assumes sysctl caller holds inp_rinfo_lock() 715 * for writting! 716 */ 717 #ifdef INET 718 if (V_udp4_tun_socket != NULL) { 719 soclose(V_udp4_tun_socket); 720 V_udp4_tun_socket = NULL; 721 } 722 #endif 723 #ifdef INET6 724 if (V_udp6_tun_socket != NULL) { 725 soclose(V_udp6_tun_socket); 726 V_udp6_tun_socket = NULL; 727 } 728 #endif 729 } 730 731 static int 732 tcp_over_udp_start(void) 733 { 734 uint16_t port; 735 int ret; 736 #ifdef INET 737 struct sockaddr_in sin; 738 #endif 739 #ifdef INET6 740 struct sockaddr_in6 sin6; 741 #endif 742 /* 743 * This function assumes sysctl caller holds inp_info_rlock() 744 * for writting! 745 */ 746 port = V_tcp_udp_tunneling_port; 747 if (ntohs(port) == 0) { 748 /* Must have a port set */ 749 return (EINVAL); 750 } 751 #ifdef INET 752 if (V_udp4_tun_socket != NULL) { 753 /* Already running -- must stop first */ 754 return (EALREADY); 755 } 756 #endif 757 #ifdef INET6 758 if (V_udp6_tun_socket != NULL) { 759 /* Already running -- must stop first */ 760 return (EALREADY); 761 } 762 #endif 763 #ifdef INET 764 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 765 SOCK_DGRAM, IPPROTO_UDP, 766 curthread->td_ucred, curthread))) { 767 tcp_over_udp_stop(); 768 return (ret); 769 } 770 /* Call the special UDP hook. */ 771 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 772 tcp_recv_udp_tunneled_packet, 773 tcp_ctlinput_viaudp, 774 NULL))) { 775 tcp_over_udp_stop(); 776 return (ret); 777 } 778 /* Ok, we have a socket, bind it to the port. */ 779 memset(&sin, 0, sizeof(struct sockaddr_in)); 780 sin.sin_len = sizeof(struct sockaddr_in); 781 sin.sin_family = AF_INET; 782 sin.sin_port = htons(port); 783 if ((ret = sobind(V_udp4_tun_socket, 784 (struct sockaddr *)&sin, curthread))) { 785 tcp_over_udp_stop(); 786 return (ret); 787 } 788 #endif 789 #ifdef INET6 790 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 791 SOCK_DGRAM, IPPROTO_UDP, 792 curthread->td_ucred, curthread))) { 793 tcp_over_udp_stop(); 794 return (ret); 795 } 796 /* Call the special UDP hook. */ 797 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 798 tcp_recv_udp_tunneled_packet, 799 tcp6_ctlinput_viaudp, 800 NULL))) { 801 tcp_over_udp_stop(); 802 return (ret); 803 } 804 /* Ok, we have a socket, bind it to the port. */ 805 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 806 sin6.sin6_len = sizeof(struct sockaddr_in6); 807 sin6.sin6_family = AF_INET6; 808 sin6.sin6_port = htons(port); 809 if ((ret = sobind(V_udp6_tun_socket, 810 (struct sockaddr *)&sin6, curthread))) { 811 tcp_over_udp_stop(); 812 return (ret); 813 } 814 #endif 815 return (0); 816 } 817 818 static int 819 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 820 { 821 int error; 822 uint32_t old, new; 823 824 old = V_tcp_udp_tunneling_port; 825 new = old; 826 error = sysctl_handle_int(oidp, &new, 0, req); 827 if ((error == 0) && 828 (req->newptr != NULL)) { 829 if ((new < TCP_TUNNELING_PORT_MIN) || 830 (new > TCP_TUNNELING_PORT_MAX)) { 831 error = EINVAL; 832 } else { 833 V_tcp_udp_tunneling_port = new; 834 if (old != 0) { 835 tcp_over_udp_stop(); 836 } 837 if (new != 0) { 838 error = tcp_over_udp_start(); 839 } 840 } 841 } 842 return (error); 843 } 844 845 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 846 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 847 &VNET_NAME(tcp_udp_tunneling_port), 848 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 849 "Tunneling port for tcp over udp"); 850 851 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 852 853 static int 854 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 855 { 856 int error, new; 857 858 new = V_tcp_udp_tunneling_overhead; 859 error = sysctl_handle_int(oidp, &new, 0, req); 860 if (error == 0 && req->newptr) { 861 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 862 (new > TCP_TUNNELING_OVERHEAD_MAX)) 863 error = EINVAL; 864 else 865 V_tcp_udp_tunneling_overhead = new; 866 } 867 return (error); 868 } 869 870 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 871 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 872 &VNET_NAME(tcp_udp_tunneling_overhead), 873 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 874 "MSS reduction when using tcp over udp"); 875 876 /* 877 * Exports one (struct tcp_function_info) for each alias/name. 878 */ 879 static int 880 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 881 { 882 int cnt, error; 883 struct tcp_function *f; 884 struct tcp_function_info tfi; 885 886 /* 887 * We don't allow writes. 888 */ 889 if (req->newptr != NULL) 890 return (EINVAL); 891 892 /* 893 * Wire the old buffer so we can directly copy the functions to 894 * user space without dropping the lock. 895 */ 896 if (req->oldptr != NULL) { 897 error = sysctl_wire_old_buffer(req, 0); 898 if (error) 899 return (error); 900 } 901 902 /* 903 * Walk the list and copy out matching entries. If INVARIANTS 904 * is compiled in, also walk the list to verify the length of 905 * the list matches what we have recorded. 906 */ 907 rw_rlock(&tcp_function_lock); 908 909 cnt = 0; 910 #ifndef INVARIANTS 911 if (req->oldptr == NULL) { 912 cnt = tcp_fb_cnt; 913 goto skip_loop; 914 } 915 #endif 916 TAILQ_FOREACH(f, &t_functions, tf_next) { 917 #ifdef INVARIANTS 918 cnt++; 919 #endif 920 if (req->oldptr != NULL) { 921 bzero(&tfi, sizeof(tfi)); 922 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 923 tfi.tfi_id = f->tf_fb->tfb_id; 924 (void)strlcpy(tfi.tfi_alias, f->tf_name, 925 sizeof(tfi.tfi_alias)); 926 (void)strlcpy(tfi.tfi_name, 927 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 928 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 929 /* 930 * Don't stop on error, as that is the 931 * mechanism we use to accumulate length 932 * information if the buffer was too short. 933 */ 934 } 935 } 936 KASSERT(cnt == tcp_fb_cnt, 937 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 938 #ifndef INVARIANTS 939 skip_loop: 940 #endif 941 rw_runlock(&tcp_function_lock); 942 if (req->oldptr == NULL) 943 error = SYSCTL_OUT(req, NULL, 944 (cnt + 1) * sizeof(struct tcp_function_info)); 945 946 return (error); 947 } 948 949 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 950 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 951 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 952 "List TCP function block name-to-ID mappings"); 953 954 /* 955 * tfb_tcp_handoff_ok() function for the default stack. 956 * Note that we'll basically try to take all comers. 957 */ 958 static int 959 tcp_default_handoff_ok(struct tcpcb *tp) 960 { 961 962 return (0); 963 } 964 965 /* 966 * tfb_tcp_fb_init() function for the default stack. 967 * 968 * This handles making sure we have appropriate timers set if you are 969 * transitioning a socket that has some amount of setup done. 970 * 971 * The init() fuction from the default can *never* return non-zero i.e. 972 * it is required to always succeed since it is the stack of last resort! 973 */ 974 static int 975 tcp_default_fb_init(struct tcpcb *tp) 976 { 977 978 struct socket *so; 979 980 INP_WLOCK_ASSERT(tp->t_inpcb); 981 982 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 983 ("%s: connection %p in unexpected state %d", __func__, tp, 984 tp->t_state)); 985 986 /* 987 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 988 * know what to do for unexpected states (which includes TIME_WAIT). 989 */ 990 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 991 return (0); 992 993 /* 994 * Make sure some kind of transmission timer is set if there is 995 * outstanding data. 996 */ 997 so = tp->t_inpcb->inp_socket; 998 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 999 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1000 tcp_timer_active(tp, TT_PERSIST))) { 1001 /* 1002 * If the session has established and it looks like it should 1003 * be in the persist state, set the persist timer. Otherwise, 1004 * set the retransmit timer. 1005 */ 1006 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1007 (int32_t)(tp->snd_nxt - tp->snd_una) < 1008 (int32_t)sbavail(&so->so_snd)) 1009 tcp_setpersist(tp); 1010 else 1011 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1012 } 1013 1014 /* All non-embryonic sessions get a keepalive timer. */ 1015 if (!tcp_timer_active(tp, TT_KEEP)) 1016 tcp_timer_activate(tp, TT_KEEP, 1017 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1018 TP_KEEPINIT(tp)); 1019 1020 /* 1021 * Make sure critical variables are initialized 1022 * if transitioning while in Recovery. 1023 */ 1024 if IN_FASTRECOVERY(tp->t_flags) { 1025 if (tp->sackhint.recover_fs == 0) 1026 tp->sackhint.recover_fs = max(1, 1027 tp->snd_nxt - tp->snd_una); 1028 } 1029 1030 return (0); 1031 } 1032 1033 /* 1034 * tfb_tcp_fb_fini() function for the default stack. 1035 * 1036 * This changes state as necessary (or prudent) to prepare for another stack 1037 * to assume responsibility for the connection. 1038 */ 1039 static void 1040 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1041 { 1042 1043 INP_WLOCK_ASSERT(tp->t_inpcb); 1044 return; 1045 } 1046 1047 /* 1048 * Target size of TCP PCB hash tables. Must be a power of two. 1049 * 1050 * Note that this can be overridden by the kernel environment 1051 * variable net.inet.tcp.tcbhashsize 1052 */ 1053 #ifndef TCBHASHSIZE 1054 #define TCBHASHSIZE 0 1055 #endif 1056 1057 /* 1058 * XXX 1059 * Callouts should be moved into struct tcp directly. They are currently 1060 * separate because the tcpcb structure is exported to userland for sysctl 1061 * parsing purposes, which do not know about callouts. 1062 */ 1063 struct tcpcb_mem { 1064 struct tcpcb tcb; 1065 struct tcp_timer tt; 1066 struct cc_var ccv; 1067 #ifdef TCP_HHOOK 1068 struct osd osd; 1069 #endif 1070 }; 1071 1072 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1073 #define V_tcpcb_zone VNET(tcpcb_zone) 1074 1075 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1076 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1077 1078 static struct mtx isn_mtx; 1079 1080 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1081 #define ISN_LOCK() mtx_lock(&isn_mtx) 1082 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1083 1084 /* 1085 * TCP initialization. 1086 */ 1087 static void 1088 tcp_zone_change(void *tag) 1089 { 1090 1091 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 1092 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1093 tcp_tw_zone_change(); 1094 } 1095 1096 static int 1097 tcp_inpcb_init(void *mem, int size, int flags) 1098 { 1099 struct inpcb *inp = mem; 1100 1101 INP_LOCK_INIT(inp, "inp", "tcpinp"); 1102 return (0); 1103 } 1104 1105 /* 1106 * Take a value and get the next power of 2 that doesn't overflow. 1107 * Used to size the tcp_inpcb hash buckets. 1108 */ 1109 static int 1110 maketcp_hashsize(int size) 1111 { 1112 int hashsize; 1113 1114 /* 1115 * auto tune. 1116 * get the next power of 2 higher than maxsockets. 1117 */ 1118 hashsize = 1 << fls(size); 1119 /* catch overflow, and just go one power of 2 smaller */ 1120 if (hashsize < size) { 1121 hashsize = 1 << (fls(size) - 1); 1122 } 1123 return (hashsize); 1124 } 1125 1126 static volatile int next_tcp_stack_id = 1; 1127 1128 /* 1129 * Register a TCP function block with the name provided in the names 1130 * array. (Note that this function does NOT automatically register 1131 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1132 * explicitly include blk->tfb_tcp_block_name in the list of names if 1133 * you wish to register the stack with that name.) 1134 * 1135 * Either all name registrations will succeed or all will fail. If 1136 * a name registration fails, the function will update the num_names 1137 * argument to point to the array index of the name that encountered 1138 * the failure. 1139 * 1140 * Returns 0 on success, or an error code on failure. 1141 */ 1142 int 1143 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1144 const char *names[], int *num_names) 1145 { 1146 struct tcp_function *n; 1147 struct tcp_function_set fs; 1148 int error, i; 1149 1150 KASSERT(names != NULL && *num_names > 0, 1151 ("%s: Called with 0-length name list", __func__)); 1152 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1153 KASSERT(rw_initialized(&tcp_function_lock), 1154 ("%s: called too early", __func__)); 1155 1156 if ((blk->tfb_tcp_output == NULL) || 1157 (blk->tfb_tcp_do_segment == NULL) || 1158 (blk->tfb_tcp_ctloutput == NULL) || 1159 (strlen(blk->tfb_tcp_block_name) == 0)) { 1160 /* 1161 * These functions are required and you 1162 * need a name. 1163 */ 1164 *num_names = 0; 1165 return (EINVAL); 1166 } 1167 if (blk->tfb_tcp_timer_stop_all || 1168 blk->tfb_tcp_timer_activate || 1169 blk->tfb_tcp_timer_active || 1170 blk->tfb_tcp_timer_stop) { 1171 /* 1172 * If you define one timer function you 1173 * must have them all. 1174 */ 1175 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1176 (blk->tfb_tcp_timer_activate == NULL) || 1177 (blk->tfb_tcp_timer_active == NULL) || 1178 (blk->tfb_tcp_timer_stop == NULL)) { 1179 *num_names = 0; 1180 return (EINVAL); 1181 } 1182 } 1183 1184 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1185 *num_names = 0; 1186 return (EINVAL); 1187 } 1188 1189 refcount_init(&blk->tfb_refcnt, 0); 1190 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1191 for (i = 0; i < *num_names; i++) { 1192 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1193 if (n == NULL) { 1194 error = ENOMEM; 1195 goto cleanup; 1196 } 1197 n->tf_fb = blk; 1198 1199 (void)strlcpy(fs.function_set_name, names[i], 1200 sizeof(fs.function_set_name)); 1201 rw_wlock(&tcp_function_lock); 1202 if (find_tcp_functions_locked(&fs) != NULL) { 1203 /* Duplicate name space not allowed */ 1204 rw_wunlock(&tcp_function_lock); 1205 free(n, M_TCPFUNCTIONS); 1206 error = EALREADY; 1207 goto cleanup; 1208 } 1209 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1210 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1211 tcp_fb_cnt++; 1212 rw_wunlock(&tcp_function_lock); 1213 } 1214 return(0); 1215 1216 cleanup: 1217 /* 1218 * Deregister the names we just added. Because registration failed 1219 * for names[i], we don't need to deregister that name. 1220 */ 1221 *num_names = i; 1222 rw_wlock(&tcp_function_lock); 1223 while (--i >= 0) { 1224 TAILQ_FOREACH(n, &t_functions, tf_next) { 1225 if (!strncmp(n->tf_name, names[i], 1226 TCP_FUNCTION_NAME_LEN_MAX)) { 1227 TAILQ_REMOVE(&t_functions, n, tf_next); 1228 tcp_fb_cnt--; 1229 n->tf_fb = NULL; 1230 free(n, M_TCPFUNCTIONS); 1231 break; 1232 } 1233 } 1234 } 1235 rw_wunlock(&tcp_function_lock); 1236 return (error); 1237 } 1238 1239 /* 1240 * Register a TCP function block using the name provided in the name 1241 * argument. 1242 * 1243 * Returns 0 on success, or an error code on failure. 1244 */ 1245 int 1246 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1247 int wait) 1248 { 1249 const char *name_list[1]; 1250 int num_names, rv; 1251 1252 num_names = 1; 1253 if (name != NULL) 1254 name_list[0] = name; 1255 else 1256 name_list[0] = blk->tfb_tcp_block_name; 1257 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1258 return (rv); 1259 } 1260 1261 /* 1262 * Register a TCP function block using the name defined in 1263 * blk->tfb_tcp_block_name. 1264 * 1265 * Returns 0 on success, or an error code on failure. 1266 */ 1267 int 1268 register_tcp_functions(struct tcp_function_block *blk, int wait) 1269 { 1270 1271 return (register_tcp_functions_as_name(blk, NULL, wait)); 1272 } 1273 1274 /* 1275 * Deregister all names associated with a function block. This 1276 * functionally removes the function block from use within the system. 1277 * 1278 * When called with a true quiesce argument, mark the function block 1279 * as being removed so no more stacks will use it and determine 1280 * whether the removal would succeed. 1281 * 1282 * When called with a false quiesce argument, actually attempt the 1283 * removal. 1284 * 1285 * When called with a force argument, attempt to switch all TCBs to 1286 * use the default stack instead of returning EBUSY. 1287 * 1288 * Returns 0 on success (or if the removal would succeed, or an error 1289 * code on failure. 1290 */ 1291 int 1292 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1293 bool force) 1294 { 1295 struct tcp_function *f; 1296 1297 if (blk == &tcp_def_funcblk) { 1298 /* You can't un-register the default */ 1299 return (EPERM); 1300 } 1301 rw_wlock(&tcp_function_lock); 1302 if (blk == tcp_func_set_ptr) { 1303 /* You can't free the current default */ 1304 rw_wunlock(&tcp_function_lock); 1305 return (EBUSY); 1306 } 1307 /* Mark the block so no more stacks can use it. */ 1308 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1309 /* 1310 * If TCBs are still attached to the stack, attempt to switch them 1311 * to the default stack. 1312 */ 1313 if (force && blk->tfb_refcnt) { 1314 struct inpcb *inp; 1315 struct tcpcb *tp; 1316 VNET_ITERATOR_DECL(vnet_iter); 1317 1318 rw_wunlock(&tcp_function_lock); 1319 1320 VNET_LIST_RLOCK(); 1321 VNET_FOREACH(vnet_iter) { 1322 CURVNET_SET(vnet_iter); 1323 INP_INFO_WLOCK(&V_tcbinfo); 1324 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1325 INP_WLOCK(inp); 1326 if (inp->inp_flags & INP_TIMEWAIT) { 1327 INP_WUNLOCK(inp); 1328 continue; 1329 } 1330 tp = intotcpcb(inp); 1331 if (tp == NULL || tp->t_fb != blk) { 1332 INP_WUNLOCK(inp); 1333 continue; 1334 } 1335 tcp_switch_back_to_default(tp); 1336 INP_WUNLOCK(inp); 1337 } 1338 INP_INFO_WUNLOCK(&V_tcbinfo); 1339 CURVNET_RESTORE(); 1340 } 1341 VNET_LIST_RUNLOCK(); 1342 1343 rw_wlock(&tcp_function_lock); 1344 } 1345 if (blk->tfb_refcnt) { 1346 /* TCBs still attached. */ 1347 rw_wunlock(&tcp_function_lock); 1348 return (EBUSY); 1349 } 1350 if (quiesce) { 1351 /* Skip removal. */ 1352 rw_wunlock(&tcp_function_lock); 1353 return (0); 1354 } 1355 /* Remove any function names that map to this function block. */ 1356 while (find_tcp_fb_locked(blk, &f) != NULL) { 1357 TAILQ_REMOVE(&t_functions, f, tf_next); 1358 tcp_fb_cnt--; 1359 f->tf_fb = NULL; 1360 free(f, M_TCPFUNCTIONS); 1361 } 1362 rw_wunlock(&tcp_function_lock); 1363 return (0); 1364 } 1365 1366 void 1367 tcp_init(void) 1368 { 1369 const char *tcbhash_tuneable; 1370 int hashsize; 1371 1372 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1373 1374 #ifdef TCP_HHOOK 1375 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1376 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1377 printf("%s: WARNING: unable to register helper hook\n", __func__); 1378 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1379 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1380 printf("%s: WARNING: unable to register helper hook\n", __func__); 1381 #endif 1382 #ifdef STATS 1383 if (tcp_stats_init()) 1384 printf("%s: WARNING: unable to initialise TCP stats\n", 1385 __func__); 1386 #endif 1387 hashsize = TCBHASHSIZE; 1388 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1389 if (hashsize == 0) { 1390 /* 1391 * Auto tune the hash size based on maxsockets. 1392 * A perfect hash would have a 1:1 mapping 1393 * (hashsize = maxsockets) however it's been 1394 * suggested that O(2) average is better. 1395 */ 1396 hashsize = maketcp_hashsize(maxsockets / 4); 1397 /* 1398 * Our historical default is 512, 1399 * do not autotune lower than this. 1400 */ 1401 if (hashsize < 512) 1402 hashsize = 512; 1403 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1404 printf("%s: %s auto tuned to %d\n", __func__, 1405 tcbhash_tuneable, hashsize); 1406 } 1407 /* 1408 * We require a hashsize to be a power of two. 1409 * Previously if it was not a power of two we would just reset it 1410 * back to 512, which could be a nasty surprise if you did not notice 1411 * the error message. 1412 * Instead what we do is clip it to the closest power of two lower 1413 * than the specified hash value. 1414 */ 1415 if (!powerof2(hashsize)) { 1416 int oldhashsize = hashsize; 1417 1418 hashsize = maketcp_hashsize(hashsize); 1419 /* prevent absurdly low value */ 1420 if (hashsize < 16) 1421 hashsize = 16; 1422 printf("%s: WARNING: TCB hash size not a power of 2, " 1423 "clipped from %d to %d.\n", __func__, oldhashsize, 1424 hashsize); 1425 } 1426 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1427 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1428 1429 /* 1430 * These have to be type stable for the benefit of the timers. 1431 */ 1432 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1433 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1434 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1435 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1436 1437 tcp_tw_init(); 1438 syncache_init(); 1439 tcp_hc_init(); 1440 1441 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1442 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1443 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1444 1445 tcp_fastopen_init(); 1446 1447 /* Skip initialization of globals for non-default instances. */ 1448 if (!IS_DEFAULT_VNET(curvnet)) 1449 return; 1450 1451 tcp_reass_global_init(); 1452 1453 /* XXX virtualize those bellow? */ 1454 tcp_delacktime = TCPTV_DELACK; 1455 tcp_keepinit = TCPTV_KEEP_INIT; 1456 tcp_keepidle = TCPTV_KEEP_IDLE; 1457 tcp_keepintvl = TCPTV_KEEPINTVL; 1458 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1459 tcp_msl = TCPTV_MSL; 1460 tcp_rexmit_initial = TCPTV_RTOBASE; 1461 if (tcp_rexmit_initial < 1) 1462 tcp_rexmit_initial = 1; 1463 tcp_rexmit_min = TCPTV_MIN; 1464 if (tcp_rexmit_min < 1) 1465 tcp_rexmit_min = 1; 1466 tcp_persmin = TCPTV_PERSMIN; 1467 tcp_persmax = TCPTV_PERSMAX; 1468 tcp_rexmit_slop = TCPTV_CPU_VAR; 1469 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1470 tcp_tcbhashsize = hashsize; 1471 1472 /* Setup the tcp function block list */ 1473 TAILQ_INIT(&t_functions); 1474 rw_init(&tcp_function_lock, "tcp_func_lock"); 1475 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1476 #ifdef TCP_BLACKBOX 1477 /* Initialize the TCP logging data. */ 1478 tcp_log_init(); 1479 #endif 1480 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1481 1482 if (tcp_soreceive_stream) { 1483 #ifdef INET 1484 tcp_usrreqs.pru_soreceive = soreceive_stream; 1485 #endif 1486 #ifdef INET6 1487 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1488 #endif /* INET6 */ 1489 } 1490 1491 #ifdef INET6 1492 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1493 #else /* INET6 */ 1494 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1495 #endif /* INET6 */ 1496 if (max_protohdr < TCP_MINPROTOHDR) 1497 max_protohdr = TCP_MINPROTOHDR; 1498 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1499 panic("tcp_init"); 1500 #undef TCP_MINPROTOHDR 1501 1502 ISN_LOCK_INIT(); 1503 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1504 SHUTDOWN_PRI_DEFAULT); 1505 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1506 EVENTHANDLER_PRI_ANY); 1507 1508 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1509 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1510 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1511 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1512 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1513 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1514 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1515 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1516 #ifdef TCPPCAP 1517 tcp_pcap_init(); 1518 #endif 1519 } 1520 1521 #ifdef VIMAGE 1522 static void 1523 tcp_destroy(void *unused __unused) 1524 { 1525 int n; 1526 #ifdef TCP_HHOOK 1527 int error; 1528 #endif 1529 1530 /* 1531 * All our processes are gone, all our sockets should be cleaned 1532 * up, which means, we should be past the tcp_discardcb() calls. 1533 * Sleep to let all tcpcb timers really disappear and cleanup. 1534 */ 1535 for (;;) { 1536 INP_LIST_RLOCK(&V_tcbinfo); 1537 n = V_tcbinfo.ipi_count; 1538 INP_LIST_RUNLOCK(&V_tcbinfo); 1539 if (n == 0) 1540 break; 1541 pause("tcpdes", hz / 10); 1542 } 1543 tcp_hc_destroy(); 1544 syncache_destroy(); 1545 tcp_tw_destroy(); 1546 in_pcbinfo_destroy(&V_tcbinfo); 1547 /* tcp_discardcb() clears the sack_holes up. */ 1548 uma_zdestroy(V_sack_hole_zone); 1549 uma_zdestroy(V_tcpcb_zone); 1550 1551 /* 1552 * Cannot free the zone until all tcpcbs are released as we attach 1553 * the allocations to them. 1554 */ 1555 tcp_fastopen_destroy(); 1556 1557 #ifdef TCP_HHOOK 1558 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1559 if (error != 0) { 1560 printf("%s: WARNING: unable to deregister helper hook " 1561 "type=%d, id=%d: error %d returned\n", __func__, 1562 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1563 } 1564 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1565 if (error != 0) { 1566 printf("%s: WARNING: unable to deregister helper hook " 1567 "type=%d, id=%d: error %d returned\n", __func__, 1568 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1569 } 1570 #endif 1571 } 1572 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1573 #endif 1574 1575 void 1576 tcp_fini(void *xtp) 1577 { 1578 1579 } 1580 1581 /* 1582 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1583 * tcp_template used to store this data in mbufs, but we now recopy it out 1584 * of the tcpcb each time to conserve mbufs. 1585 */ 1586 void 1587 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1588 { 1589 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1590 1591 INP_WLOCK_ASSERT(inp); 1592 1593 #ifdef INET6 1594 if ((inp->inp_vflag & INP_IPV6) != 0) { 1595 struct ip6_hdr *ip6; 1596 1597 ip6 = (struct ip6_hdr *)ip_ptr; 1598 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1599 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1600 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1601 (IPV6_VERSION & IPV6_VERSION_MASK); 1602 if (port == 0) 1603 ip6->ip6_nxt = IPPROTO_TCP; 1604 else 1605 ip6->ip6_nxt = IPPROTO_UDP; 1606 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1607 ip6->ip6_src = inp->in6p_laddr; 1608 ip6->ip6_dst = inp->in6p_faddr; 1609 } 1610 #endif /* INET6 */ 1611 #if defined(INET6) && defined(INET) 1612 else 1613 #endif 1614 #ifdef INET 1615 { 1616 struct ip *ip; 1617 1618 ip = (struct ip *)ip_ptr; 1619 ip->ip_v = IPVERSION; 1620 ip->ip_hl = 5; 1621 ip->ip_tos = inp->inp_ip_tos; 1622 ip->ip_len = 0; 1623 ip->ip_id = 0; 1624 ip->ip_off = 0; 1625 ip->ip_ttl = inp->inp_ip_ttl; 1626 ip->ip_sum = 0; 1627 if (port == 0) 1628 ip->ip_p = IPPROTO_TCP; 1629 else 1630 ip->ip_p = IPPROTO_UDP; 1631 ip->ip_src = inp->inp_laddr; 1632 ip->ip_dst = inp->inp_faddr; 1633 } 1634 #endif /* INET */ 1635 th->th_sport = inp->inp_lport; 1636 th->th_dport = inp->inp_fport; 1637 th->th_seq = 0; 1638 th->th_ack = 0; 1639 th->th_x2 = 0; 1640 th->th_off = 5; 1641 th->th_flags = 0; 1642 th->th_win = 0; 1643 th->th_urp = 0; 1644 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1645 } 1646 1647 /* 1648 * Create template to be used to send tcp packets on a connection. 1649 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1650 * use for this function is in keepalives, which use tcp_respond. 1651 */ 1652 struct tcptemp * 1653 tcpip_maketemplate(struct inpcb *inp) 1654 { 1655 struct tcptemp *t; 1656 1657 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1658 if (t == NULL) 1659 return (NULL); 1660 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1661 return (t); 1662 } 1663 1664 /* 1665 * Send a single message to the TCP at address specified by 1666 * the given TCP/IP header. If m == NULL, then we make a copy 1667 * of the tcpiphdr at th and send directly to the addressed host. 1668 * This is used to force keep alive messages out using the TCP 1669 * template for a connection. If flags are given then we send 1670 * a message back to the TCP which originated the segment th, 1671 * and discard the mbuf containing it and any other attached mbufs. 1672 * 1673 * In any case the ack and sequence number of the transmitted 1674 * segment are as specified by the parameters. 1675 * 1676 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1677 */ 1678 void 1679 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1680 tcp_seq ack, tcp_seq seq, int flags) 1681 { 1682 struct tcpopt to; 1683 struct inpcb *inp; 1684 struct ip *ip; 1685 struct mbuf *optm; 1686 struct udphdr *uh = NULL; 1687 struct tcphdr *nth; 1688 u_char *optp; 1689 #ifdef INET6 1690 struct ip6_hdr *ip6; 1691 int isipv6; 1692 #endif /* INET6 */ 1693 int optlen, tlen, win, ulen; 1694 bool incl_opts; 1695 uint16_t port; 1696 1697 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1698 NET_EPOCH_ASSERT(); 1699 1700 #ifdef INET6 1701 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1702 ip6 = ipgen; 1703 #endif /* INET6 */ 1704 ip = ipgen; 1705 1706 if (tp != NULL) { 1707 inp = tp->t_inpcb; 1708 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1709 INP_LOCK_ASSERT(inp); 1710 } else 1711 inp = NULL; 1712 1713 if (m != NULL) { 1714 #ifdef INET6 1715 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1716 port = m->m_pkthdr.tcp_tun_port; 1717 else 1718 #endif 1719 if (ip && (ip->ip_p == IPPROTO_UDP)) 1720 port = m->m_pkthdr.tcp_tun_port; 1721 else 1722 port = 0; 1723 } else 1724 port = tp->t_port; 1725 1726 incl_opts = false; 1727 win = 0; 1728 if (tp != NULL) { 1729 if (!(flags & TH_RST)) { 1730 win = sbspace(&inp->inp_socket->so_rcv); 1731 if (win > TCP_MAXWIN << tp->rcv_scale) 1732 win = TCP_MAXWIN << tp->rcv_scale; 1733 } 1734 if ((tp->t_flags & TF_NOOPT) == 0) 1735 incl_opts = true; 1736 } 1737 if (m == NULL) { 1738 m = m_gethdr(M_NOWAIT, MT_DATA); 1739 if (m == NULL) 1740 return; 1741 m->m_data += max_linkhdr; 1742 #ifdef INET6 1743 if (isipv6) { 1744 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1745 sizeof(struct ip6_hdr)); 1746 ip6 = mtod(m, struct ip6_hdr *); 1747 nth = (struct tcphdr *)(ip6 + 1); 1748 if (port) { 1749 /* Insert a UDP header */ 1750 uh = (struct udphdr *)nth; 1751 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1752 uh->uh_dport = port; 1753 nth = (struct tcphdr *)(uh + 1); 1754 } 1755 } else 1756 #endif /* INET6 */ 1757 { 1758 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1759 ip = mtod(m, struct ip *); 1760 nth = (struct tcphdr *)(ip + 1); 1761 if (port) { 1762 /* Insert a UDP header */ 1763 uh = (struct udphdr *)nth; 1764 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1765 uh->uh_dport = port; 1766 nth = (struct tcphdr *)(uh + 1); 1767 } 1768 } 1769 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1770 flags = TH_ACK; 1771 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1772 struct mbuf *n; 1773 1774 /* Can't reuse 'm', allocate a new mbuf. */ 1775 n = m_gethdr(M_NOWAIT, MT_DATA); 1776 if (n == NULL) { 1777 m_freem(m); 1778 return; 1779 } 1780 1781 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1782 m_freem(m); 1783 m_freem(n); 1784 return; 1785 } 1786 1787 n->m_data += max_linkhdr; 1788 /* m_len is set later */ 1789 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1790 #ifdef INET6 1791 if (isipv6) { 1792 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1793 sizeof(struct ip6_hdr)); 1794 ip6 = mtod(n, struct ip6_hdr *); 1795 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1796 nth = (struct tcphdr *)(ip6 + 1); 1797 if (port) { 1798 /* Insert a UDP header */ 1799 uh = (struct udphdr *)nth; 1800 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1801 uh->uh_dport = port; 1802 nth = (struct tcphdr *)(uh + 1); 1803 } 1804 } else 1805 #endif /* INET6 */ 1806 { 1807 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1808 ip = mtod(n, struct ip *); 1809 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1810 nth = (struct tcphdr *)(ip + 1); 1811 if (port) { 1812 /* Insert a UDP header */ 1813 uh = (struct udphdr *)nth; 1814 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1815 uh->uh_dport = port; 1816 nth = (struct tcphdr *)(uh + 1); 1817 } 1818 } 1819 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1820 xchg(nth->th_dport, nth->th_sport, uint16_t); 1821 th = nth; 1822 m_freem(m); 1823 m = n; 1824 } else { 1825 /* 1826 * reuse the mbuf. 1827 * XXX MRT We inherit the FIB, which is lucky. 1828 */ 1829 m_freem(m->m_next); 1830 m->m_next = NULL; 1831 m->m_data = (caddr_t)ipgen; 1832 /* m_len is set later */ 1833 #ifdef INET6 1834 if (isipv6) { 1835 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1836 nth = (struct tcphdr *)(ip6 + 1); 1837 } else 1838 #endif /* INET6 */ 1839 { 1840 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1841 nth = (struct tcphdr *)(ip + 1); 1842 } 1843 if (th != nth) { 1844 /* 1845 * this is usually a case when an extension header 1846 * exists between the IPv6 header and the 1847 * TCP header. 1848 */ 1849 nth->th_sport = th->th_sport; 1850 nth->th_dport = th->th_dport; 1851 } 1852 xchg(nth->th_dport, nth->th_sport, uint16_t); 1853 #undef xchg 1854 } 1855 tlen = 0; 1856 #ifdef INET6 1857 if (isipv6) 1858 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1859 #endif 1860 #if defined(INET) && defined(INET6) 1861 else 1862 #endif 1863 #ifdef INET 1864 tlen = sizeof (struct tcpiphdr); 1865 #endif 1866 if (port) 1867 tlen += sizeof (struct udphdr); 1868 #ifdef INVARIANTS 1869 m->m_len = 0; 1870 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1871 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1872 m, tlen, (long)M_TRAILINGSPACE(m))); 1873 #endif 1874 m->m_len = tlen; 1875 to.to_flags = 0; 1876 if (incl_opts) { 1877 /* Make sure we have room. */ 1878 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1879 m->m_next = m_get(M_NOWAIT, MT_DATA); 1880 if (m->m_next) { 1881 optp = mtod(m->m_next, u_char *); 1882 optm = m->m_next; 1883 } else 1884 incl_opts = false; 1885 } else { 1886 optp = (u_char *) (nth + 1); 1887 optm = m; 1888 } 1889 } 1890 if (incl_opts) { 1891 /* Timestamps. */ 1892 if (tp->t_flags & TF_RCVD_TSTMP) { 1893 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1894 to.to_tsecr = tp->ts_recent; 1895 to.to_flags |= TOF_TS; 1896 } 1897 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1898 /* TCP-MD5 (RFC2385). */ 1899 if (tp->t_flags & TF_SIGNATURE) 1900 to.to_flags |= TOF_SIGNATURE; 1901 #endif 1902 /* Add the options. */ 1903 tlen += optlen = tcp_addoptions(&to, optp); 1904 1905 /* Update m_len in the correct mbuf. */ 1906 optm->m_len += optlen; 1907 } else 1908 optlen = 0; 1909 #ifdef INET6 1910 if (isipv6) { 1911 if (uh) { 1912 ulen = tlen - sizeof(struct ip6_hdr); 1913 uh->uh_ulen = htons(ulen); 1914 } 1915 ip6->ip6_flow = 0; 1916 ip6->ip6_vfc = IPV6_VERSION; 1917 if (port) 1918 ip6->ip6_nxt = IPPROTO_UDP; 1919 else 1920 ip6->ip6_nxt = IPPROTO_TCP; 1921 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1922 } 1923 #endif 1924 #if defined(INET) && defined(INET6) 1925 else 1926 #endif 1927 #ifdef INET 1928 { 1929 if (uh) { 1930 ulen = tlen - sizeof(struct ip); 1931 uh->uh_ulen = htons(ulen); 1932 } 1933 ip->ip_len = htons(tlen); 1934 ip->ip_ttl = V_ip_defttl; 1935 if (port) { 1936 ip->ip_p = IPPROTO_UDP; 1937 } else { 1938 ip->ip_p = IPPROTO_TCP; 1939 } 1940 if (V_path_mtu_discovery) 1941 ip->ip_off |= htons(IP_DF); 1942 } 1943 #endif 1944 m->m_pkthdr.len = tlen; 1945 m->m_pkthdr.rcvif = NULL; 1946 #ifdef MAC 1947 if (inp != NULL) { 1948 /* 1949 * Packet is associated with a socket, so allow the 1950 * label of the response to reflect the socket label. 1951 */ 1952 INP_LOCK_ASSERT(inp); 1953 mac_inpcb_create_mbuf(inp, m); 1954 } else { 1955 /* 1956 * Packet is not associated with a socket, so possibly 1957 * update the label in place. 1958 */ 1959 mac_netinet_tcp_reply(m); 1960 } 1961 #endif 1962 nth->th_seq = htonl(seq); 1963 nth->th_ack = htonl(ack); 1964 nth->th_x2 = 0; 1965 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1966 nth->th_flags = flags; 1967 if (tp != NULL) 1968 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1969 else 1970 nth->th_win = htons((u_short)win); 1971 nth->th_urp = 0; 1972 1973 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1974 if (to.to_flags & TOF_SIGNATURE) { 1975 if (!TCPMD5_ENABLED() || 1976 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1977 m_freem(m); 1978 return; 1979 } 1980 } 1981 #endif 1982 1983 #ifdef INET6 1984 if (isipv6) { 1985 if (port) { 1986 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 1987 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1988 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 1989 nth->th_sum = 0; 1990 } else { 1991 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1992 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1993 nth->th_sum = in6_cksum_pseudo(ip6, 1994 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1995 } 1996 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1997 NULL, NULL); 1998 } 1999 #endif /* INET6 */ 2000 #if defined(INET6) && defined(INET) 2001 else 2002 #endif 2003 #ifdef INET 2004 { 2005 if (port) { 2006 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2007 htons(ulen + IPPROTO_UDP)); 2008 m->m_pkthdr.csum_flags = CSUM_UDP; 2009 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2010 nth->th_sum = 0; 2011 } else { 2012 m->m_pkthdr.csum_flags = CSUM_TCP; 2013 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2014 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2015 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2016 } 2017 } 2018 #endif /* INET */ 2019 #ifdef TCPDEBUG 2020 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2021 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2022 #endif 2023 TCP_PROBE3(debug__output, tp, th, m); 2024 if (flags & TH_RST) 2025 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2026 2027 #ifdef INET6 2028 if (isipv6) { 2029 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2030 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2031 } 2032 #endif /* INET6 */ 2033 #if defined(INET) && defined(INET6) 2034 else 2035 #endif 2036 #ifdef INET 2037 { 2038 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2039 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 2040 } 2041 #endif 2042 } 2043 2044 /* 2045 * Create a new TCP control block, making an 2046 * empty reassembly queue and hooking it to the argument 2047 * protocol control block. The `inp' parameter must have 2048 * come from the zone allocator set up in tcp_init(). 2049 */ 2050 struct tcpcb * 2051 tcp_newtcpcb(struct inpcb *inp) 2052 { 2053 struct tcpcb_mem *tm; 2054 struct tcpcb *tp; 2055 #ifdef INET6 2056 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2057 #endif /* INET6 */ 2058 2059 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2060 if (tm == NULL) 2061 return (NULL); 2062 tp = &tm->tcb; 2063 2064 /* Initialise cc_var struct for this tcpcb. */ 2065 tp->ccv = &tm->ccv; 2066 tp->ccv->type = IPPROTO_TCP; 2067 tp->ccv->ccvc.tcp = tp; 2068 rw_rlock(&tcp_function_lock); 2069 tp->t_fb = tcp_func_set_ptr; 2070 refcount_acquire(&tp->t_fb->tfb_refcnt); 2071 rw_runlock(&tcp_function_lock); 2072 /* 2073 * Use the current system default CC algorithm. 2074 */ 2075 CC_LIST_RLOCK(); 2076 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 2077 CC_ALGO(tp) = CC_DEFAULT(); 2078 CC_LIST_RUNLOCK(); 2079 /* 2080 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2081 * is called. 2082 */ 2083 in_pcbref(inp); /* Reference for tcpcb */ 2084 tp->t_inpcb = inp; 2085 2086 if (CC_ALGO(tp)->cb_init != NULL) 2087 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 2088 if (tp->t_fb->tfb_tcp_fb_fini) 2089 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2090 in_pcbrele_wlocked(inp); 2091 refcount_release(&tp->t_fb->tfb_refcnt); 2092 uma_zfree(V_tcpcb_zone, tm); 2093 return (NULL); 2094 } 2095 2096 #ifdef TCP_HHOOK 2097 tp->osd = &tm->osd; 2098 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2099 if (tp->t_fb->tfb_tcp_fb_fini) 2100 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2101 in_pcbrele_wlocked(inp); 2102 refcount_release(&tp->t_fb->tfb_refcnt); 2103 uma_zfree(V_tcpcb_zone, tm); 2104 return (NULL); 2105 } 2106 #endif 2107 2108 #ifdef VIMAGE 2109 tp->t_vnet = inp->inp_vnet; 2110 #endif 2111 tp->t_timers = &tm->tt; 2112 TAILQ_INIT(&tp->t_segq); 2113 tp->t_maxseg = 2114 #ifdef INET6 2115 isipv6 ? V_tcp_v6mssdflt : 2116 #endif /* INET6 */ 2117 V_tcp_mssdflt; 2118 2119 /* Set up our timeouts. */ 2120 callout_init(&tp->t_timers->tt_rexmt, 1); 2121 callout_init(&tp->t_timers->tt_persist, 1); 2122 callout_init(&tp->t_timers->tt_keep, 1); 2123 callout_init(&tp->t_timers->tt_2msl, 1); 2124 callout_init(&tp->t_timers->tt_delack, 1); 2125 2126 if (V_tcp_do_rfc1323) 2127 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2128 if (V_tcp_do_sack) 2129 tp->t_flags |= TF_SACK_PERMIT; 2130 TAILQ_INIT(&tp->snd_holes); 2131 2132 /* 2133 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2134 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2135 * reasonable initial retransmit time. 2136 */ 2137 tp->t_srtt = TCPTV_SRTTBASE; 2138 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2139 tp->t_rttmin = tcp_rexmit_min; 2140 tp->t_rxtcur = tcp_rexmit_initial; 2141 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2142 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2143 tp->t_rcvtime = ticks; 2144 /* 2145 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2146 * because the socket may be bound to an IPv6 wildcard address, 2147 * which may match an IPv4-mapped IPv6 address. 2148 */ 2149 inp->inp_ip_ttl = V_ip_defttl; 2150 inp->inp_ppcb = tp; 2151 #ifdef TCPPCAP 2152 /* 2153 * Init the TCP PCAP queues. 2154 */ 2155 tcp_pcap_tcpcb_init(tp); 2156 #endif 2157 #ifdef TCP_BLACKBOX 2158 /* Initialize the per-TCPCB log data. */ 2159 tcp_log_tcpcbinit(tp); 2160 #endif 2161 tp->t_pacing_rate = -1; 2162 if (tp->t_fb->tfb_tcp_fb_init) { 2163 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2164 refcount_release(&tp->t_fb->tfb_refcnt); 2165 in_pcbrele_wlocked(inp); 2166 uma_zfree(V_tcpcb_zone, tm); 2167 return (NULL); 2168 } 2169 } 2170 #ifdef STATS 2171 if (V_tcp_perconn_stats_enable == 1) 2172 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2173 #endif 2174 if (V_tcp_do_lrd) 2175 tp->t_flags |= TF_LRD; 2176 return (tp); /* XXX */ 2177 } 2178 2179 /* 2180 * Switch the congestion control algorithm back to NewReno for any active 2181 * control blocks using an algorithm which is about to go away. 2182 * This ensures the CC framework can allow the unload to proceed without leaving 2183 * any dangling pointers which would trigger a panic. 2184 * Returning non-zero would inform the CC framework that something went wrong 2185 * and it would be unsafe to allow the unload to proceed. However, there is no 2186 * way for this to occur with this implementation so we always return zero. 2187 */ 2188 int 2189 tcp_ccalgounload(struct cc_algo *unload_algo) 2190 { 2191 struct cc_algo *tmpalgo; 2192 struct inpcb *inp; 2193 struct tcpcb *tp; 2194 VNET_ITERATOR_DECL(vnet_iter); 2195 2196 /* 2197 * Check all active control blocks across all network stacks and change 2198 * any that are using "unload_algo" back to NewReno. If "unload_algo" 2199 * requires cleanup code to be run, call it. 2200 */ 2201 VNET_LIST_RLOCK(); 2202 VNET_FOREACH(vnet_iter) { 2203 CURVNET_SET(vnet_iter); 2204 INP_INFO_WLOCK(&V_tcbinfo); 2205 /* 2206 * New connections already part way through being initialised 2207 * with the CC algo we're removing will not race with this code 2208 * because the INP_INFO_WLOCK is held during initialisation. We 2209 * therefore don't enter the loop below until the connection 2210 * list has stabilised. 2211 */ 2212 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 2213 INP_WLOCK(inp); 2214 /* Important to skip tcptw structs. */ 2215 if (!(inp->inp_flags & INP_TIMEWAIT) && 2216 (tp = intotcpcb(inp)) != NULL) { 2217 /* 2218 * By holding INP_WLOCK here, we are assured 2219 * that the connection is not currently 2220 * executing inside the CC module's functions 2221 * i.e. it is safe to make the switch back to 2222 * NewReno. 2223 */ 2224 if (CC_ALGO(tp) == unload_algo) { 2225 tmpalgo = CC_ALGO(tp); 2226 if (tmpalgo->cb_destroy != NULL) 2227 tmpalgo->cb_destroy(tp->ccv); 2228 CC_DATA(tp) = NULL; 2229 /* 2230 * NewReno may allocate memory on 2231 * demand for certain stateful 2232 * configuration as needed, but is 2233 * coded to never fail on memory 2234 * allocation failure so it is a safe 2235 * fallback. 2236 */ 2237 CC_ALGO(tp) = &newreno_cc_algo; 2238 } 2239 } 2240 INP_WUNLOCK(inp); 2241 } 2242 INP_INFO_WUNLOCK(&V_tcbinfo); 2243 CURVNET_RESTORE(); 2244 } 2245 VNET_LIST_RUNLOCK(); 2246 2247 return (0); 2248 } 2249 2250 /* 2251 * Drop a TCP connection, reporting 2252 * the specified error. If connection is synchronized, 2253 * then send a RST to peer. 2254 */ 2255 struct tcpcb * 2256 tcp_drop(struct tcpcb *tp, int errno) 2257 { 2258 struct socket *so = tp->t_inpcb->inp_socket; 2259 2260 NET_EPOCH_ASSERT(); 2261 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2262 INP_WLOCK_ASSERT(tp->t_inpcb); 2263 2264 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2265 tcp_state_change(tp, TCPS_CLOSED); 2266 (void) tp->t_fb->tfb_tcp_output(tp); 2267 TCPSTAT_INC(tcps_drops); 2268 } else 2269 TCPSTAT_INC(tcps_conndrops); 2270 if (errno == ETIMEDOUT && tp->t_softerror) 2271 errno = tp->t_softerror; 2272 so->so_error = errno; 2273 return (tcp_close(tp)); 2274 } 2275 2276 void 2277 tcp_discardcb(struct tcpcb *tp) 2278 { 2279 struct inpcb *inp = tp->t_inpcb; 2280 struct socket *so = inp->inp_socket; 2281 #ifdef INET6 2282 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2283 #endif /* INET6 */ 2284 int released __unused; 2285 2286 INP_WLOCK_ASSERT(inp); 2287 2288 /* 2289 * Make sure that all of our timers are stopped before we delete the 2290 * PCB. 2291 * 2292 * If stopping a timer fails, we schedule a discard function in same 2293 * callout, and the last discard function called will take care of 2294 * deleting the tcpcb. 2295 */ 2296 tp->t_timers->tt_draincnt = 0; 2297 tcp_timer_stop(tp, TT_REXMT); 2298 tcp_timer_stop(tp, TT_PERSIST); 2299 tcp_timer_stop(tp, TT_KEEP); 2300 tcp_timer_stop(tp, TT_2MSL); 2301 tcp_timer_stop(tp, TT_DELACK); 2302 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2303 /* 2304 * Call the stop-all function of the methods, 2305 * this function should call the tcp_timer_stop() 2306 * method with each of the function specific timeouts. 2307 * That stop will be called via the tfb_tcp_timer_stop() 2308 * which should use the async drain function of the 2309 * callout system (see tcp_var.h). 2310 */ 2311 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2312 } 2313 2314 /* free the reassembly queue, if any */ 2315 tcp_reass_flush(tp); 2316 2317 #ifdef TCP_OFFLOAD 2318 /* Disconnect offload device, if any. */ 2319 if (tp->t_flags & TF_TOE) 2320 tcp_offload_detach(tp); 2321 #endif 2322 2323 tcp_free_sackholes(tp); 2324 2325 #ifdef TCPPCAP 2326 /* Free the TCP PCAP queues. */ 2327 tcp_pcap_drain(&(tp->t_inpkts)); 2328 tcp_pcap_drain(&(tp->t_outpkts)); 2329 #endif 2330 2331 /* Allow the CC algorithm to clean up after itself. */ 2332 if (CC_ALGO(tp)->cb_destroy != NULL) 2333 CC_ALGO(tp)->cb_destroy(tp->ccv); 2334 CC_DATA(tp) = NULL; 2335 2336 #ifdef TCP_HHOOK 2337 khelp_destroy_osd(tp->osd); 2338 #endif 2339 #ifdef STATS 2340 stats_blob_destroy(tp->t_stats); 2341 #endif 2342 2343 CC_ALGO(tp) = NULL; 2344 inp->inp_ppcb = NULL; 2345 if (tp->t_timers->tt_draincnt == 0) { 2346 /* We own the last reference on tcpcb, let's free it. */ 2347 #ifdef TCP_BLACKBOX 2348 tcp_log_tcpcbfini(tp); 2349 #endif 2350 TCPSTATES_DEC(tp->t_state); 2351 if (tp->t_fb->tfb_tcp_fb_fini) 2352 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2353 2354 /* 2355 * If we got enough samples through the srtt filter, 2356 * save the rtt and rttvar in the routing entry. 2357 * 'Enough' is arbitrarily defined as 4 rtt samples. 2358 * 4 samples is enough for the srtt filter to converge 2359 * to within enough % of the correct value; fewer samples 2360 * and we could save a bogus rtt. The danger is not high 2361 * as tcp quickly recovers from everything. 2362 * XXX: Works very well but needs some more statistics! 2363 * 2364 * XXXRRS: Updating must be after the stack fini() since 2365 * that may be converting some internal representation of 2366 * say srtt etc into the general one used by other stacks. 2367 * Lets also at least protect against the so being NULL 2368 * as RW stated below. 2369 */ 2370 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2371 struct hc_metrics_lite metrics; 2372 uint32_t ssthresh; 2373 2374 bzero(&metrics, sizeof(metrics)); 2375 /* 2376 * Update the ssthresh always when the conditions below 2377 * are satisfied. This gives us better new start value 2378 * for the congestion avoidance for new connections. 2379 * ssthresh is only set if packet loss occurred on a session. 2380 * 2381 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2382 * being torn down. Ideally this code would not use 'so'. 2383 */ 2384 ssthresh = tp->snd_ssthresh; 2385 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2386 /* 2387 * convert the limit from user data bytes to 2388 * packets then to packet data bytes. 2389 */ 2390 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2391 if (ssthresh < 2) 2392 ssthresh = 2; 2393 ssthresh *= (tp->t_maxseg + 2394 #ifdef INET6 2395 (isipv6 ? sizeof (struct ip6_hdr) + 2396 sizeof (struct tcphdr) : 2397 #endif 2398 sizeof (struct tcpiphdr) 2399 #ifdef INET6 2400 ) 2401 #endif 2402 ); 2403 } else 2404 ssthresh = 0; 2405 metrics.rmx_ssthresh = ssthresh; 2406 2407 metrics.rmx_rtt = tp->t_srtt; 2408 metrics.rmx_rttvar = tp->t_rttvar; 2409 metrics.rmx_cwnd = tp->snd_cwnd; 2410 metrics.rmx_sendpipe = 0; 2411 metrics.rmx_recvpipe = 0; 2412 2413 tcp_hc_update(&inp->inp_inc, &metrics); 2414 } 2415 refcount_release(&tp->t_fb->tfb_refcnt); 2416 tp->t_inpcb = NULL; 2417 uma_zfree(V_tcpcb_zone, tp); 2418 released = in_pcbrele_wlocked(inp); 2419 KASSERT(!released, ("%s: inp %p should not have been released " 2420 "here", __func__, inp)); 2421 } 2422 } 2423 2424 void 2425 tcp_timer_discard(void *ptp) 2426 { 2427 struct inpcb *inp; 2428 struct tcpcb *tp; 2429 struct epoch_tracker et; 2430 2431 tp = (struct tcpcb *)ptp; 2432 CURVNET_SET(tp->t_vnet); 2433 NET_EPOCH_ENTER(et); 2434 inp = tp->t_inpcb; 2435 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 2436 __func__, tp)); 2437 INP_WLOCK(inp); 2438 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 2439 ("%s: tcpcb has to be stopped here", __func__)); 2440 tp->t_timers->tt_draincnt--; 2441 if (tp->t_timers->tt_draincnt == 0) { 2442 /* We own the last reference on this tcpcb, let's free it. */ 2443 #ifdef TCP_BLACKBOX 2444 tcp_log_tcpcbfini(tp); 2445 #endif 2446 TCPSTATES_DEC(tp->t_state); 2447 if (tp->t_fb->tfb_tcp_fb_fini) 2448 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2449 refcount_release(&tp->t_fb->tfb_refcnt); 2450 tp->t_inpcb = NULL; 2451 uma_zfree(V_tcpcb_zone, tp); 2452 if (in_pcbrele_wlocked(inp)) { 2453 NET_EPOCH_EXIT(et); 2454 CURVNET_RESTORE(); 2455 return; 2456 } 2457 } 2458 INP_WUNLOCK(inp); 2459 NET_EPOCH_EXIT(et); 2460 CURVNET_RESTORE(); 2461 } 2462 2463 /* 2464 * Attempt to close a TCP control block, marking it as dropped, and freeing 2465 * the socket if we hold the only reference. 2466 */ 2467 struct tcpcb * 2468 tcp_close(struct tcpcb *tp) 2469 { 2470 struct inpcb *inp = tp->t_inpcb; 2471 struct socket *so; 2472 2473 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2474 INP_WLOCK_ASSERT(inp); 2475 2476 #ifdef TCP_OFFLOAD 2477 if (tp->t_state == TCPS_LISTEN) 2478 tcp_offload_listen_stop(tp); 2479 #endif 2480 /* 2481 * This releases the TFO pending counter resource for TFO listen 2482 * sockets as well as passively-created TFO sockets that transition 2483 * from SYN_RECEIVED to CLOSED. 2484 */ 2485 if (tp->t_tfo_pending) { 2486 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2487 tp->t_tfo_pending = NULL; 2488 } 2489 in_pcbdrop(inp); 2490 TCPSTAT_INC(tcps_closed); 2491 if (tp->t_state != TCPS_CLOSED) 2492 tcp_state_change(tp, TCPS_CLOSED); 2493 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2494 so = inp->inp_socket; 2495 soisdisconnected(so); 2496 if (inp->inp_flags & INP_SOCKREF) { 2497 KASSERT(so->so_state & SS_PROTOREF, 2498 ("tcp_close: !SS_PROTOREF")); 2499 inp->inp_flags &= ~INP_SOCKREF; 2500 INP_WUNLOCK(inp); 2501 SOCK_LOCK(so); 2502 so->so_state &= ~SS_PROTOREF; 2503 sofree(so); 2504 return (NULL); 2505 } 2506 return (tp); 2507 } 2508 2509 void 2510 tcp_drain(void) 2511 { 2512 VNET_ITERATOR_DECL(vnet_iter); 2513 2514 if (!do_tcpdrain) 2515 return; 2516 2517 VNET_LIST_RLOCK_NOSLEEP(); 2518 VNET_FOREACH(vnet_iter) { 2519 CURVNET_SET(vnet_iter); 2520 struct inpcb *inpb; 2521 struct tcpcb *tcpb; 2522 2523 /* 2524 * Walk the tcpbs, if existing, and flush the reassembly queue, 2525 * if there is one... 2526 * XXX: The "Net/3" implementation doesn't imply that the TCP 2527 * reassembly queue should be flushed, but in a situation 2528 * where we're really low on mbufs, this is potentially 2529 * useful. 2530 */ 2531 INP_INFO_WLOCK(&V_tcbinfo); 2532 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2533 INP_WLOCK(inpb); 2534 if (inpb->inp_flags & INP_TIMEWAIT) { 2535 INP_WUNLOCK(inpb); 2536 continue; 2537 } 2538 if ((tcpb = intotcpcb(inpb)) != NULL) { 2539 tcp_reass_flush(tcpb); 2540 tcp_clean_sackreport(tcpb); 2541 #ifdef TCP_BLACKBOX 2542 tcp_log_drain(tcpb); 2543 #endif 2544 #ifdef TCPPCAP 2545 if (tcp_pcap_aggressive_free) { 2546 /* Free the TCP PCAP queues. */ 2547 tcp_pcap_drain(&(tcpb->t_inpkts)); 2548 tcp_pcap_drain(&(tcpb->t_outpkts)); 2549 } 2550 #endif 2551 } 2552 INP_WUNLOCK(inpb); 2553 } 2554 INP_INFO_WUNLOCK(&V_tcbinfo); 2555 CURVNET_RESTORE(); 2556 } 2557 VNET_LIST_RUNLOCK_NOSLEEP(); 2558 } 2559 2560 /* 2561 * Notify a tcp user of an asynchronous error; 2562 * store error as soft error, but wake up user 2563 * (for now, won't do anything until can select for soft error). 2564 * 2565 * Do not wake up user since there currently is no mechanism for 2566 * reporting soft errors (yet - a kqueue filter may be added). 2567 */ 2568 static struct inpcb * 2569 tcp_notify(struct inpcb *inp, int error) 2570 { 2571 struct tcpcb *tp; 2572 2573 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2574 INP_WLOCK_ASSERT(inp); 2575 2576 if ((inp->inp_flags & INP_TIMEWAIT) || 2577 (inp->inp_flags & INP_DROPPED)) 2578 return (inp); 2579 2580 tp = intotcpcb(inp); 2581 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2582 2583 /* 2584 * Ignore some errors if we are hooked up. 2585 * If connection hasn't completed, has retransmitted several times, 2586 * and receives a second error, give up now. This is better 2587 * than waiting a long time to establish a connection that 2588 * can never complete. 2589 */ 2590 if (tp->t_state == TCPS_ESTABLISHED && 2591 (error == EHOSTUNREACH || error == ENETUNREACH || 2592 error == EHOSTDOWN)) { 2593 if (inp->inp_route.ro_nh) { 2594 NH_FREE(inp->inp_route.ro_nh); 2595 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2596 } 2597 return (inp); 2598 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2599 tp->t_softerror) { 2600 tp = tcp_drop(tp, error); 2601 if (tp != NULL) 2602 return (inp); 2603 else 2604 return (NULL); 2605 } else { 2606 tp->t_softerror = error; 2607 return (inp); 2608 } 2609 #if 0 2610 wakeup( &so->so_timeo); 2611 sorwakeup(so); 2612 sowwakeup(so); 2613 #endif 2614 } 2615 2616 static int 2617 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2618 { 2619 struct epoch_tracker et; 2620 struct inpcb *inp; 2621 struct xinpgen xig; 2622 int error; 2623 2624 if (req->newptr != NULL) 2625 return (EPERM); 2626 2627 if (req->oldptr == NULL) { 2628 int n; 2629 2630 n = V_tcbinfo.ipi_count + 2631 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2632 n += imax(n / 8, 10); 2633 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2634 return (0); 2635 } 2636 2637 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2638 return (error); 2639 2640 bzero(&xig, sizeof(xig)); 2641 xig.xig_len = sizeof xig; 2642 xig.xig_count = V_tcbinfo.ipi_count + 2643 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2644 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2645 xig.xig_sogen = so_gencnt; 2646 error = SYSCTL_OUT(req, &xig, sizeof xig); 2647 if (error) 2648 return (error); 2649 2650 error = syncache_pcblist(req); 2651 if (error) 2652 return (error); 2653 2654 NET_EPOCH_ENTER(et); 2655 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2656 inp != NULL; 2657 inp = CK_LIST_NEXT(inp, inp_list)) { 2658 INP_RLOCK(inp); 2659 if (inp->inp_gencnt <= xig.xig_gen) { 2660 int crerr; 2661 2662 /* 2663 * XXX: This use of cr_cansee(), introduced with 2664 * TCP state changes, is not quite right, but for 2665 * now, better than nothing. 2666 */ 2667 if (inp->inp_flags & INP_TIMEWAIT) { 2668 if (intotw(inp) != NULL) 2669 crerr = cr_cansee(req->td->td_ucred, 2670 intotw(inp)->tw_cred); 2671 else 2672 crerr = EINVAL; /* Skip this inp. */ 2673 } else 2674 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2675 if (crerr == 0) { 2676 struct xtcpcb xt; 2677 2678 tcp_inptoxtp(inp, &xt); 2679 INP_RUNLOCK(inp); 2680 error = SYSCTL_OUT(req, &xt, sizeof xt); 2681 if (error) 2682 break; 2683 else 2684 continue; 2685 } 2686 } 2687 INP_RUNLOCK(inp); 2688 } 2689 NET_EPOCH_EXIT(et); 2690 2691 if (!error) { 2692 /* 2693 * Give the user an updated idea of our state. 2694 * If the generation differs from what we told 2695 * her before, she knows that something happened 2696 * while we were processing this request, and it 2697 * might be necessary to retry. 2698 */ 2699 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2700 xig.xig_sogen = so_gencnt; 2701 xig.xig_count = V_tcbinfo.ipi_count + 2702 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2703 error = SYSCTL_OUT(req, &xig, sizeof xig); 2704 } 2705 2706 return (error); 2707 } 2708 2709 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2710 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2711 NULL, 0, tcp_pcblist, "S,xtcpcb", 2712 "List of active TCP connections"); 2713 2714 #ifdef INET 2715 static int 2716 tcp_getcred(SYSCTL_HANDLER_ARGS) 2717 { 2718 struct xucred xuc; 2719 struct sockaddr_in addrs[2]; 2720 struct epoch_tracker et; 2721 struct inpcb *inp; 2722 int error; 2723 2724 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2725 if (error) 2726 return (error); 2727 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2728 if (error) 2729 return (error); 2730 NET_EPOCH_ENTER(et); 2731 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2732 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2733 NET_EPOCH_EXIT(et); 2734 if (inp != NULL) { 2735 if (inp->inp_socket == NULL) 2736 error = ENOENT; 2737 if (error == 0) 2738 error = cr_canseeinpcb(req->td->td_ucred, inp); 2739 if (error == 0) 2740 cru2x(inp->inp_cred, &xuc); 2741 INP_RUNLOCK(inp); 2742 } else 2743 error = ENOENT; 2744 if (error == 0) 2745 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2746 return (error); 2747 } 2748 2749 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2750 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2751 0, 0, tcp_getcred, "S,xucred", 2752 "Get the xucred of a TCP connection"); 2753 #endif /* INET */ 2754 2755 #ifdef INET6 2756 static int 2757 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2758 { 2759 struct epoch_tracker et; 2760 struct xucred xuc; 2761 struct sockaddr_in6 addrs[2]; 2762 struct inpcb *inp; 2763 int error; 2764 #ifdef INET 2765 int mapped = 0; 2766 #endif 2767 2768 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2769 if (error) 2770 return (error); 2771 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2772 if (error) 2773 return (error); 2774 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2775 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2776 return (error); 2777 } 2778 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2779 #ifdef INET 2780 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2781 mapped = 1; 2782 else 2783 #endif 2784 return (EINVAL); 2785 } 2786 2787 NET_EPOCH_ENTER(et); 2788 #ifdef INET 2789 if (mapped == 1) 2790 inp = in_pcblookup(&V_tcbinfo, 2791 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2792 addrs[1].sin6_port, 2793 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2794 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2795 else 2796 #endif 2797 inp = in6_pcblookup(&V_tcbinfo, 2798 &addrs[1].sin6_addr, addrs[1].sin6_port, 2799 &addrs[0].sin6_addr, addrs[0].sin6_port, 2800 INPLOOKUP_RLOCKPCB, NULL); 2801 NET_EPOCH_EXIT(et); 2802 if (inp != NULL) { 2803 if (inp->inp_socket == NULL) 2804 error = ENOENT; 2805 if (error == 0) 2806 error = cr_canseeinpcb(req->td->td_ucred, inp); 2807 if (error == 0) 2808 cru2x(inp->inp_cred, &xuc); 2809 INP_RUNLOCK(inp); 2810 } else 2811 error = ENOENT; 2812 if (error == 0) 2813 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2814 return (error); 2815 } 2816 2817 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2818 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2819 0, 0, tcp6_getcred, "S,xucred", 2820 "Get the xucred of a TCP6 connection"); 2821 #endif /* INET6 */ 2822 2823 #ifdef INET 2824 /* Path MTU to try next when a fragmentation-needed message is received. */ 2825 static inline int 2826 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2827 { 2828 int mtu = ntohs(icp->icmp_nextmtu); 2829 2830 /* If no alternative MTU was proposed, try the next smaller one. */ 2831 if (!mtu) 2832 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2833 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2834 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2835 2836 return (mtu); 2837 } 2838 2839 static void 2840 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2841 { 2842 struct ip *ip = vip; 2843 struct tcphdr *th; 2844 struct in_addr faddr; 2845 struct inpcb *inp; 2846 struct tcpcb *tp; 2847 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2848 struct icmp *icp; 2849 struct in_conninfo inc; 2850 tcp_seq icmp_tcp_seq; 2851 int mtu; 2852 2853 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2854 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2855 return; 2856 2857 if (cmd == PRC_MSGSIZE) 2858 notify = tcp_mtudisc_notify; 2859 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2860 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2861 cmd == PRC_TIMXCEED_INTRANS) && ip) 2862 notify = tcp_drop_syn_sent; 2863 2864 /* 2865 * Hostdead is ugly because it goes linearly through all PCBs. 2866 * XXX: We never get this from ICMP, otherwise it makes an 2867 * excellent DoS attack on machines with many connections. 2868 */ 2869 else if (cmd == PRC_HOSTDEAD) 2870 ip = NULL; 2871 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2872 return; 2873 2874 if (ip == NULL) { 2875 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2876 return; 2877 } 2878 2879 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2880 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2881 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2882 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2883 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2884 /* signal EHOSTDOWN, as it flushes the cached route */ 2885 inp = (*notify)(inp, EHOSTDOWN); 2886 goto out; 2887 } 2888 icmp_tcp_seq = th->th_seq; 2889 if (inp != NULL) { 2890 if (!(inp->inp_flags & INP_TIMEWAIT) && 2891 !(inp->inp_flags & INP_DROPPED) && 2892 !(inp->inp_socket == NULL)) { 2893 tp = intotcpcb(inp); 2894 #ifdef TCP_OFFLOAD 2895 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2896 /* 2897 * MTU discovery for offloaded connections. Let 2898 * the TOE driver verify seq# and process it. 2899 */ 2900 mtu = tcp_next_pmtu(icp, ip); 2901 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2902 goto out; 2903 } 2904 #endif 2905 if (tp->t_port != port) { 2906 goto out; 2907 } 2908 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2909 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2910 if (cmd == PRC_MSGSIZE) { 2911 /* 2912 * MTU discovery: we got a needfrag and 2913 * will potentially try a lower MTU. 2914 */ 2915 mtu = tcp_next_pmtu(icp, ip); 2916 2917 /* 2918 * Only process the offered MTU if it 2919 * is smaller than the current one. 2920 */ 2921 if (mtu < tp->t_maxseg + 2922 sizeof(struct tcpiphdr)) { 2923 bzero(&inc, sizeof(inc)); 2924 inc.inc_faddr = faddr; 2925 inc.inc_fibnum = 2926 inp->inp_inc.inc_fibnum; 2927 tcp_hc_updatemtu(&inc, mtu); 2928 tcp_mtudisc(inp, mtu); 2929 } 2930 } else 2931 inp = (*notify)(inp, 2932 inetctlerrmap[cmd]); 2933 } 2934 } 2935 } else { 2936 bzero(&inc, sizeof(inc)); 2937 inc.inc_fport = th->th_dport; 2938 inc.inc_lport = th->th_sport; 2939 inc.inc_faddr = faddr; 2940 inc.inc_laddr = ip->ip_src; 2941 syncache_unreach(&inc, icmp_tcp_seq, port); 2942 } 2943 out: 2944 if (inp != NULL) 2945 INP_WUNLOCK(inp); 2946 } 2947 2948 void 2949 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2950 { 2951 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2952 } 2953 2954 void 2955 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2956 { 2957 /* Its a tunneled TCP over UDP icmp */ 2958 struct ip *outer_ip, *inner_ip; 2959 struct icmp *icmp; 2960 struct udphdr *udp; 2961 struct tcphdr *th, ttemp; 2962 int i_hlen, o_len; 2963 uint16_t port; 2964 2965 inner_ip = (struct ip *)vip; 2966 icmp = (struct icmp *)((caddr_t)inner_ip - 2967 (sizeof(struct icmp) - sizeof(struct ip))); 2968 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2969 i_hlen = inner_ip->ip_hl << 2; 2970 o_len = ntohs(outer_ip->ip_len); 2971 if (o_len < 2972 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2973 /* Not enough data present */ 2974 return; 2975 } 2976 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2977 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2978 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2979 return; 2980 } 2981 port = udp->uh_dport; 2982 th = (struct tcphdr *)(udp + 1); 2983 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2984 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2985 /* Now adjust down the size of the outer IP header */ 2986 o_len -= sizeof(struct udphdr); 2987 outer_ip->ip_len = htons(o_len); 2988 /* Now call in to the normal handling code */ 2989 tcp_ctlinput_with_port(cmd, sa, vip, port); 2990 } 2991 #endif /* INET */ 2992 2993 #ifdef INET6 2994 static inline int 2995 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2996 { 2997 int mtu = ntohl(icmp6->icmp6_mtu); 2998 2999 /* 3000 * If no alternative MTU was proposed, or the proposed MTU was too 3001 * small, set to the min. 3002 */ 3003 if (mtu < IPV6_MMTU) 3004 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3005 return (mtu); 3006 } 3007 3008 static void 3009 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3010 { 3011 struct in6_addr *dst; 3012 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3013 struct ip6_hdr *ip6; 3014 struct mbuf *m; 3015 struct inpcb *inp; 3016 struct tcpcb *tp; 3017 struct icmp6_hdr *icmp6; 3018 struct ip6ctlparam *ip6cp = NULL; 3019 const struct sockaddr_in6 *sa6_src = NULL; 3020 struct in_conninfo inc; 3021 struct tcp_ports { 3022 uint16_t th_sport; 3023 uint16_t th_dport; 3024 } t_ports; 3025 tcp_seq icmp_tcp_seq; 3026 unsigned int mtu; 3027 unsigned int off; 3028 3029 if (sa->sa_family != AF_INET6 || 3030 sa->sa_len != sizeof(struct sockaddr_in6)) 3031 return; 3032 3033 /* if the parameter is from icmp6, decode it. */ 3034 if (d != NULL) { 3035 ip6cp = (struct ip6ctlparam *)d; 3036 icmp6 = ip6cp->ip6c_icmp6; 3037 m = ip6cp->ip6c_m; 3038 ip6 = ip6cp->ip6c_ip6; 3039 off = ip6cp->ip6c_off; 3040 sa6_src = ip6cp->ip6c_src; 3041 dst = ip6cp->ip6c_finaldst; 3042 } else { 3043 m = NULL; 3044 ip6 = NULL; 3045 off = 0; /* fool gcc */ 3046 sa6_src = &sa6_any; 3047 dst = NULL; 3048 } 3049 3050 if (cmd == PRC_MSGSIZE) 3051 notify = tcp_mtudisc_notify; 3052 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3053 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3054 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3055 notify = tcp_drop_syn_sent; 3056 3057 /* 3058 * Hostdead is ugly because it goes linearly through all PCBs. 3059 * XXX: We never get this from ICMP, otherwise it makes an 3060 * excellent DoS attack on machines with many connections. 3061 */ 3062 else if (cmd == PRC_HOSTDEAD) 3063 ip6 = NULL; 3064 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3065 return; 3066 3067 if (ip6 == NULL) { 3068 in6_pcbnotify(&V_tcbinfo, sa, 0, 3069 (const struct sockaddr *)sa6_src, 3070 0, cmd, NULL, notify); 3071 return; 3072 } 3073 3074 /* Check if we can safely get the ports from the tcp hdr */ 3075 if (m == NULL || 3076 (m->m_pkthdr.len < 3077 (int32_t) (off + sizeof(struct tcp_ports)))) { 3078 return; 3079 } 3080 bzero(&t_ports, sizeof(struct tcp_ports)); 3081 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3082 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3083 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3084 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3085 /* signal EHOSTDOWN, as it flushes the cached route */ 3086 inp = (*notify)(inp, EHOSTDOWN); 3087 goto out; 3088 } 3089 off += sizeof(struct tcp_ports); 3090 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3091 goto out; 3092 } 3093 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3094 if (inp != NULL) { 3095 if (!(inp->inp_flags & INP_TIMEWAIT) && 3096 !(inp->inp_flags & INP_DROPPED) && 3097 !(inp->inp_socket == NULL)) { 3098 tp = intotcpcb(inp); 3099 #ifdef TCP_OFFLOAD 3100 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3101 /* MTU discovery for offloaded connections. */ 3102 mtu = tcp6_next_pmtu(icmp6); 3103 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3104 goto out; 3105 } 3106 #endif 3107 if (tp->t_port != port) { 3108 goto out; 3109 } 3110 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3111 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3112 if (cmd == PRC_MSGSIZE) { 3113 /* 3114 * MTU discovery: 3115 * If we got a needfrag set the MTU 3116 * in the route to the suggested new 3117 * value (if given) and then notify. 3118 */ 3119 mtu = tcp6_next_pmtu(icmp6); 3120 3121 bzero(&inc, sizeof(inc)); 3122 inc.inc_fibnum = M_GETFIB(m); 3123 inc.inc_flags |= INC_ISIPV6; 3124 inc.inc6_faddr = *dst; 3125 if (in6_setscope(&inc.inc6_faddr, 3126 m->m_pkthdr.rcvif, NULL)) 3127 goto out; 3128 /* 3129 * Only process the offered MTU if it 3130 * is smaller than the current one. 3131 */ 3132 if (mtu < tp->t_maxseg + 3133 sizeof (struct tcphdr) + 3134 sizeof (struct ip6_hdr)) { 3135 tcp_hc_updatemtu(&inc, mtu); 3136 tcp_mtudisc(inp, mtu); 3137 ICMP6STAT_INC(icp6s_pmtuchg); 3138 } 3139 } else 3140 inp = (*notify)(inp, 3141 inet6ctlerrmap[cmd]); 3142 } 3143 } 3144 } else { 3145 bzero(&inc, sizeof(inc)); 3146 inc.inc_fibnum = M_GETFIB(m); 3147 inc.inc_flags |= INC_ISIPV6; 3148 inc.inc_fport = t_ports.th_dport; 3149 inc.inc_lport = t_ports.th_sport; 3150 inc.inc6_faddr = *dst; 3151 inc.inc6_laddr = ip6->ip6_src; 3152 syncache_unreach(&inc, icmp_tcp_seq, port); 3153 } 3154 out: 3155 if (inp != NULL) 3156 INP_WUNLOCK(inp); 3157 } 3158 3159 void 3160 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3161 { 3162 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3163 } 3164 3165 void 3166 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3167 { 3168 struct ip6ctlparam *ip6cp; 3169 struct mbuf *m; 3170 struct udphdr *udp; 3171 uint16_t port; 3172 3173 ip6cp = (struct ip6ctlparam *)d; 3174 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3175 if (m == NULL) { 3176 return; 3177 } 3178 udp = mtod(m, struct udphdr *); 3179 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3180 return; 3181 } 3182 port = udp->uh_dport; 3183 m_adj(m, sizeof(struct udphdr)); 3184 if ((m->m_flags & M_PKTHDR) == 0) { 3185 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3186 } 3187 /* Now call in to the normal handling code */ 3188 tcp6_ctlinput_with_port(cmd, sa, d, port); 3189 } 3190 3191 #endif /* INET6 */ 3192 3193 static uint32_t 3194 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3195 { 3196 SIPHASH_CTX ctx; 3197 uint32_t hash[2]; 3198 3199 KASSERT(len >= SIPHASH_KEY_LENGTH, 3200 ("%s: keylen %u too short ", __func__, len)); 3201 SipHash24_Init(&ctx); 3202 SipHash_SetKey(&ctx, (uint8_t *)key); 3203 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3204 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3205 switch (inc->inc_flags & INC_ISIPV6) { 3206 #ifdef INET 3207 case 0: 3208 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3209 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3210 break; 3211 #endif 3212 #ifdef INET6 3213 case INC_ISIPV6: 3214 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3215 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3216 break; 3217 #endif 3218 } 3219 SipHash_Final((uint8_t *)hash, &ctx); 3220 3221 return (hash[0] ^ hash[1]); 3222 } 3223 3224 uint32_t 3225 tcp_new_ts_offset(struct in_conninfo *inc) 3226 { 3227 struct in_conninfo inc_store, *local_inc; 3228 3229 if (!V_tcp_ts_offset_per_conn) { 3230 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3231 inc_store.inc_lport = 0; 3232 inc_store.inc_fport = 0; 3233 local_inc = &inc_store; 3234 } else { 3235 local_inc = inc; 3236 } 3237 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3238 sizeof(V_ts_offset_secret))); 3239 } 3240 3241 /* 3242 * Following is where TCP initial sequence number generation occurs. 3243 * 3244 * There are two places where we must use initial sequence numbers: 3245 * 1. In SYN-ACK packets. 3246 * 2. In SYN packets. 3247 * 3248 * All ISNs for SYN-ACK packets are generated by the syncache. See 3249 * tcp_syncache.c for details. 3250 * 3251 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3252 * depends on this property. In addition, these ISNs should be 3253 * unguessable so as to prevent connection hijacking. To satisfy 3254 * the requirements of this situation, the algorithm outlined in 3255 * RFC 1948 is used, with only small modifications. 3256 * 3257 * Implementation details: 3258 * 3259 * Time is based off the system timer, and is corrected so that it 3260 * increases by one megabyte per second. This allows for proper 3261 * recycling on high speed LANs while still leaving over an hour 3262 * before rollover. 3263 * 3264 * As reading the *exact* system time is too expensive to be done 3265 * whenever setting up a TCP connection, we increment the time 3266 * offset in two ways. First, a small random positive increment 3267 * is added to isn_offset for each connection that is set up. 3268 * Second, the function tcp_isn_tick fires once per clock tick 3269 * and increments isn_offset as necessary so that sequence numbers 3270 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3271 * random positive increments serve only to ensure that the same 3272 * exact sequence number is never sent out twice (as could otherwise 3273 * happen when a port is recycled in less than the system tick 3274 * interval.) 3275 * 3276 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3277 * between seeding of isn_secret. This is normally set to zero, 3278 * as reseeding should not be necessary. 3279 * 3280 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3281 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3282 * general, this means holding an exclusive (write) lock. 3283 */ 3284 3285 #define ISN_BYTES_PER_SECOND 1048576 3286 #define ISN_STATIC_INCREMENT 4096 3287 #define ISN_RANDOM_INCREMENT (4096 - 1) 3288 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3289 3290 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3291 VNET_DEFINE_STATIC(int, isn_last); 3292 VNET_DEFINE_STATIC(int, isn_last_reseed); 3293 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3294 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3295 3296 #define V_isn_secret VNET(isn_secret) 3297 #define V_isn_last VNET(isn_last) 3298 #define V_isn_last_reseed VNET(isn_last_reseed) 3299 #define V_isn_offset VNET(isn_offset) 3300 #define V_isn_offset_old VNET(isn_offset_old) 3301 3302 tcp_seq 3303 tcp_new_isn(struct in_conninfo *inc) 3304 { 3305 tcp_seq new_isn; 3306 u_int32_t projected_offset; 3307 3308 ISN_LOCK(); 3309 /* Seed if this is the first use, reseed if requested. */ 3310 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3311 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3312 < (u_int)ticks))) { 3313 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3314 V_isn_last_reseed = ticks; 3315 } 3316 3317 /* Compute the hash and return the ISN. */ 3318 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3319 sizeof(V_isn_secret)); 3320 V_isn_offset += ISN_STATIC_INCREMENT + 3321 (arc4random() & ISN_RANDOM_INCREMENT); 3322 if (ticks != V_isn_last) { 3323 projected_offset = V_isn_offset_old + 3324 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3325 if (SEQ_GT(projected_offset, V_isn_offset)) 3326 V_isn_offset = projected_offset; 3327 V_isn_offset_old = V_isn_offset; 3328 V_isn_last = ticks; 3329 } 3330 new_isn += V_isn_offset; 3331 ISN_UNLOCK(); 3332 return (new_isn); 3333 } 3334 3335 /* 3336 * When a specific ICMP unreachable message is received and the 3337 * connection state is SYN-SENT, drop the connection. This behavior 3338 * is controlled by the icmp_may_rst sysctl. 3339 */ 3340 struct inpcb * 3341 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3342 { 3343 struct tcpcb *tp; 3344 3345 NET_EPOCH_ASSERT(); 3346 INP_WLOCK_ASSERT(inp); 3347 3348 if ((inp->inp_flags & INP_TIMEWAIT) || 3349 (inp->inp_flags & INP_DROPPED)) 3350 return (inp); 3351 3352 tp = intotcpcb(inp); 3353 if (tp->t_state != TCPS_SYN_SENT) 3354 return (inp); 3355 3356 if (IS_FASTOPEN(tp->t_flags)) 3357 tcp_fastopen_disable_path(tp); 3358 3359 tp = tcp_drop(tp, errno); 3360 if (tp != NULL) 3361 return (inp); 3362 else 3363 return (NULL); 3364 } 3365 3366 /* 3367 * When `need fragmentation' ICMP is received, update our idea of the MSS 3368 * based on the new value. Also nudge TCP to send something, since we 3369 * know the packet we just sent was dropped. 3370 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3371 */ 3372 static struct inpcb * 3373 tcp_mtudisc_notify(struct inpcb *inp, int error) 3374 { 3375 3376 tcp_mtudisc(inp, -1); 3377 return (inp); 3378 } 3379 3380 static void 3381 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3382 { 3383 struct tcpcb *tp; 3384 struct socket *so; 3385 3386 INP_WLOCK_ASSERT(inp); 3387 if ((inp->inp_flags & INP_TIMEWAIT) || 3388 (inp->inp_flags & INP_DROPPED)) 3389 return; 3390 3391 tp = intotcpcb(inp); 3392 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3393 3394 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3395 3396 so = inp->inp_socket; 3397 SOCKBUF_LOCK(&so->so_snd); 3398 /* If the mss is larger than the socket buffer, decrease the mss. */ 3399 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3400 tp->t_maxseg = so->so_snd.sb_hiwat; 3401 SOCKBUF_UNLOCK(&so->so_snd); 3402 3403 TCPSTAT_INC(tcps_mturesent); 3404 tp->t_rtttime = 0; 3405 tp->snd_nxt = tp->snd_una; 3406 tcp_free_sackholes(tp); 3407 tp->snd_recover = tp->snd_max; 3408 if (tp->t_flags & TF_SACK_PERMIT) 3409 EXIT_FASTRECOVERY(tp->t_flags); 3410 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3411 /* 3412 * Conceptually the snd_nxt setting 3413 * and freeing sack holes should 3414 * be done by the default stacks 3415 * own tfb_tcp_mtu_chg(). 3416 */ 3417 tp->t_fb->tfb_tcp_mtu_chg(tp); 3418 } 3419 tp->t_fb->tfb_tcp_output(tp); 3420 } 3421 3422 #ifdef INET 3423 /* 3424 * Look-up the routing entry to the peer of this inpcb. If no route 3425 * is found and it cannot be allocated, then return 0. This routine 3426 * is called by TCP routines that access the rmx structure and by 3427 * tcp_mss_update to get the peer/interface MTU. 3428 */ 3429 uint32_t 3430 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3431 { 3432 struct nhop_object *nh; 3433 struct ifnet *ifp; 3434 uint32_t maxmtu = 0; 3435 3436 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3437 3438 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3439 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3440 if (nh == NULL) 3441 return (0); 3442 3443 ifp = nh->nh_ifp; 3444 maxmtu = nh->nh_mtu; 3445 3446 /* Report additional interface capabilities. */ 3447 if (cap != NULL) { 3448 if (ifp->if_capenable & IFCAP_TSO4 && 3449 ifp->if_hwassist & CSUM_TSO) { 3450 cap->ifcap |= CSUM_TSO; 3451 cap->tsomax = ifp->if_hw_tsomax; 3452 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3453 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3454 } 3455 } 3456 } 3457 return (maxmtu); 3458 } 3459 #endif /* INET */ 3460 3461 #ifdef INET6 3462 uint32_t 3463 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3464 { 3465 struct nhop_object *nh; 3466 struct in6_addr dst6; 3467 uint32_t scopeid; 3468 struct ifnet *ifp; 3469 uint32_t maxmtu = 0; 3470 3471 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3472 3473 if (inc->inc_flags & INC_IPV6MINMTU) 3474 return (IPV6_MMTU); 3475 3476 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3477 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3478 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3479 if (nh == NULL) 3480 return (0); 3481 3482 ifp = nh->nh_ifp; 3483 maxmtu = nh->nh_mtu; 3484 3485 /* Report additional interface capabilities. */ 3486 if (cap != NULL) { 3487 if (ifp->if_capenable & IFCAP_TSO6 && 3488 ifp->if_hwassist & CSUM_TSO) { 3489 cap->ifcap |= CSUM_TSO; 3490 cap->tsomax = ifp->if_hw_tsomax; 3491 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3492 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3493 } 3494 } 3495 } 3496 3497 return (maxmtu); 3498 } 3499 #endif /* INET6 */ 3500 3501 /* 3502 * Calculate effective SMSS per RFC5681 definition for a given TCP 3503 * connection at its current state, taking into account SACK and etc. 3504 */ 3505 u_int 3506 tcp_maxseg(const struct tcpcb *tp) 3507 { 3508 u_int optlen; 3509 3510 if (tp->t_flags & TF_NOOPT) 3511 return (tp->t_maxseg); 3512 3513 /* 3514 * Here we have a simplified code from tcp_addoptions(), 3515 * without a proper loop, and having most of paddings hardcoded. 3516 * We might make mistakes with padding here in some edge cases, 3517 * but this is harmless, since result of tcp_maxseg() is used 3518 * only in cwnd and ssthresh estimations. 3519 */ 3520 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3521 if (tp->t_flags & TF_RCVD_TSTMP) 3522 optlen = TCPOLEN_TSTAMP_APPA; 3523 else 3524 optlen = 0; 3525 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3526 if (tp->t_flags & TF_SIGNATURE) 3527 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3528 #endif 3529 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3530 optlen += TCPOLEN_SACKHDR; 3531 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3532 optlen = PADTCPOLEN(optlen); 3533 } 3534 } else { 3535 if (tp->t_flags & TF_REQ_TSTMP) 3536 optlen = TCPOLEN_TSTAMP_APPA; 3537 else 3538 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3539 if (tp->t_flags & TF_REQ_SCALE) 3540 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3541 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3542 if (tp->t_flags & TF_SIGNATURE) 3543 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3544 #endif 3545 if (tp->t_flags & TF_SACK_PERMIT) 3546 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3547 } 3548 #undef PAD 3549 optlen = min(optlen, TCP_MAXOLEN); 3550 return (tp->t_maxseg - optlen); 3551 } 3552 3553 3554 u_int 3555 tcp_fixed_maxseg(const struct tcpcb *tp) 3556 { 3557 int optlen; 3558 3559 if (tp->t_flags & TF_NOOPT) 3560 return (tp->t_maxseg); 3561 3562 /* 3563 * Here we have a simplified code from tcp_addoptions(), 3564 * without a proper loop, and having most of paddings hardcoded. 3565 * We only consider fixed options that we would send every 3566 * time I.e. SACK is not considered. This is important 3567 * for cc modules to figure out what the modulo of the 3568 * cwnd should be. 3569 */ 3570 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3571 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3572 if (tp->t_flags & TF_RCVD_TSTMP) 3573 optlen = TCPOLEN_TSTAMP_APPA; 3574 else 3575 optlen = 0; 3576 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3577 if (tp->t_flags & TF_SIGNATURE) 3578 optlen += PAD(TCPOLEN_SIGNATURE); 3579 #endif 3580 } else { 3581 if (tp->t_flags & TF_REQ_TSTMP) 3582 optlen = TCPOLEN_TSTAMP_APPA; 3583 else 3584 optlen = PAD(TCPOLEN_MAXSEG); 3585 if (tp->t_flags & TF_REQ_SCALE) 3586 optlen += PAD(TCPOLEN_WINDOW); 3587 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3588 if (tp->t_flags & TF_SIGNATURE) 3589 optlen += PAD(TCPOLEN_SIGNATURE); 3590 #endif 3591 if (tp->t_flags & TF_SACK_PERMIT) 3592 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3593 } 3594 #undef PAD 3595 optlen = min(optlen, TCP_MAXOLEN); 3596 return (tp->t_maxseg - optlen); 3597 } 3598 3599 3600 3601 static int 3602 sysctl_drop(SYSCTL_HANDLER_ARGS) 3603 { 3604 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3605 struct sockaddr_storage addrs[2]; 3606 struct inpcb *inp; 3607 struct tcpcb *tp; 3608 struct tcptw *tw; 3609 struct sockaddr_in *fin, *lin; 3610 struct epoch_tracker et; 3611 #ifdef INET6 3612 struct sockaddr_in6 *fin6, *lin6; 3613 #endif 3614 int error; 3615 3616 inp = NULL; 3617 fin = lin = NULL; 3618 #ifdef INET6 3619 fin6 = lin6 = NULL; 3620 #endif 3621 error = 0; 3622 3623 if (req->oldptr != NULL || req->oldlen != 0) 3624 return (EINVAL); 3625 if (req->newptr == NULL) 3626 return (EPERM); 3627 if (req->newlen < sizeof(addrs)) 3628 return (ENOMEM); 3629 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3630 if (error) 3631 return (error); 3632 3633 switch (addrs[0].ss_family) { 3634 #ifdef INET6 3635 case AF_INET6: 3636 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3637 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3638 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3639 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3640 return (EINVAL); 3641 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3642 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3643 return (EINVAL); 3644 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3645 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3646 fin = (struct sockaddr_in *)&addrs[0]; 3647 lin = (struct sockaddr_in *)&addrs[1]; 3648 break; 3649 } 3650 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3651 if (error) 3652 return (error); 3653 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3654 if (error) 3655 return (error); 3656 break; 3657 #endif 3658 #ifdef INET 3659 case AF_INET: 3660 fin = (struct sockaddr_in *)&addrs[0]; 3661 lin = (struct sockaddr_in *)&addrs[1]; 3662 if (fin->sin_len != sizeof(struct sockaddr_in) || 3663 lin->sin_len != sizeof(struct sockaddr_in)) 3664 return (EINVAL); 3665 break; 3666 #endif 3667 default: 3668 return (EINVAL); 3669 } 3670 NET_EPOCH_ENTER(et); 3671 switch (addrs[0].ss_family) { 3672 #ifdef INET6 3673 case AF_INET6: 3674 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3675 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3676 INPLOOKUP_WLOCKPCB, NULL); 3677 break; 3678 #endif 3679 #ifdef INET 3680 case AF_INET: 3681 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3682 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3683 break; 3684 #endif 3685 } 3686 if (inp != NULL) { 3687 if (inp->inp_flags & INP_TIMEWAIT) { 3688 /* 3689 * XXXRW: There currently exists a state where an 3690 * inpcb is present, but its timewait state has been 3691 * discarded. For now, don't allow dropping of this 3692 * type of inpcb. 3693 */ 3694 tw = intotw(inp); 3695 if (tw != NULL) 3696 tcp_twclose(tw, 0); 3697 else 3698 INP_WUNLOCK(inp); 3699 } else if (!(inp->inp_flags & INP_DROPPED) && 3700 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 3701 tp = intotcpcb(inp); 3702 tp = tcp_drop(tp, ECONNABORTED); 3703 if (tp != NULL) 3704 INP_WUNLOCK(inp); 3705 } else 3706 INP_WUNLOCK(inp); 3707 } else 3708 error = ESRCH; 3709 NET_EPOCH_EXIT(et); 3710 return (error); 3711 } 3712 3713 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3714 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3715 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3716 "Drop TCP connection"); 3717 3718 #ifdef KERN_TLS 3719 static int 3720 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3721 { 3722 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3723 struct sockaddr_storage addrs[2]; 3724 struct inpcb *inp; 3725 struct sockaddr_in *fin, *lin; 3726 struct epoch_tracker et; 3727 #ifdef INET6 3728 struct sockaddr_in6 *fin6, *lin6; 3729 #endif 3730 int error; 3731 3732 inp = NULL; 3733 fin = lin = NULL; 3734 #ifdef INET6 3735 fin6 = lin6 = NULL; 3736 #endif 3737 error = 0; 3738 3739 if (req->oldptr != NULL || req->oldlen != 0) 3740 return (EINVAL); 3741 if (req->newptr == NULL) 3742 return (EPERM); 3743 if (req->newlen < sizeof(addrs)) 3744 return (ENOMEM); 3745 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3746 if (error) 3747 return (error); 3748 3749 switch (addrs[0].ss_family) { 3750 #ifdef INET6 3751 case AF_INET6: 3752 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3753 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3754 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3755 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3756 return (EINVAL); 3757 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3758 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3759 return (EINVAL); 3760 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3761 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3762 fin = (struct sockaddr_in *)&addrs[0]; 3763 lin = (struct sockaddr_in *)&addrs[1]; 3764 break; 3765 } 3766 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3767 if (error) 3768 return (error); 3769 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3770 if (error) 3771 return (error); 3772 break; 3773 #endif 3774 #ifdef INET 3775 case AF_INET: 3776 fin = (struct sockaddr_in *)&addrs[0]; 3777 lin = (struct sockaddr_in *)&addrs[1]; 3778 if (fin->sin_len != sizeof(struct sockaddr_in) || 3779 lin->sin_len != sizeof(struct sockaddr_in)) 3780 return (EINVAL); 3781 break; 3782 #endif 3783 default: 3784 return (EINVAL); 3785 } 3786 NET_EPOCH_ENTER(et); 3787 switch (addrs[0].ss_family) { 3788 #ifdef INET6 3789 case AF_INET6: 3790 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3791 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3792 INPLOOKUP_WLOCKPCB, NULL); 3793 break; 3794 #endif 3795 #ifdef INET 3796 case AF_INET: 3797 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3798 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3799 break; 3800 #endif 3801 } 3802 NET_EPOCH_EXIT(et); 3803 if (inp != NULL) { 3804 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3805 inp->inp_socket == NULL) { 3806 error = ECONNRESET; 3807 INP_WUNLOCK(inp); 3808 } else { 3809 struct socket *so; 3810 3811 so = inp->inp_socket; 3812 soref(so); 3813 error = ktls_set_tx_mode(so, 3814 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3815 INP_WUNLOCK(inp); 3816 SOCK_LOCK(so); 3817 sorele(so); 3818 } 3819 } else 3820 error = ESRCH; 3821 return (error); 3822 } 3823 3824 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3825 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3826 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3827 "Switch TCP connection to SW TLS"); 3828 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3829 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3830 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3831 "Switch TCP connection to ifnet TLS"); 3832 #endif 3833 3834 /* 3835 * Generate a standardized TCP log line for use throughout the 3836 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3837 * allow use in the interrupt context. 3838 * 3839 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3840 * NB: The function may return NULL if memory allocation failed. 3841 * 3842 * Due to header inclusion and ordering limitations the struct ip 3843 * and ip6_hdr pointers have to be passed as void pointers. 3844 */ 3845 char * 3846 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3847 const void *ip6hdr) 3848 { 3849 3850 /* Is logging enabled? */ 3851 if (V_tcp_log_in_vain == 0) 3852 return (NULL); 3853 3854 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3855 } 3856 3857 char * 3858 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3859 const void *ip6hdr) 3860 { 3861 3862 /* Is logging enabled? */ 3863 if (tcp_log_debug == 0) 3864 return (NULL); 3865 3866 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3867 } 3868 3869 static char * 3870 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3871 const void *ip6hdr) 3872 { 3873 char *s, *sp; 3874 size_t size; 3875 struct ip *ip; 3876 #ifdef INET6 3877 const struct ip6_hdr *ip6; 3878 3879 ip6 = (const struct ip6_hdr *)ip6hdr; 3880 #endif /* INET6 */ 3881 ip = (struct ip *)ip4hdr; 3882 3883 /* 3884 * The log line looks like this: 3885 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3886 */ 3887 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3888 sizeof(PRINT_TH_FLAGS) + 1 + 3889 #ifdef INET6 3890 2 * INET6_ADDRSTRLEN; 3891 #else 3892 2 * INET_ADDRSTRLEN; 3893 #endif /* INET6 */ 3894 3895 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3896 if (s == NULL) 3897 return (NULL); 3898 3899 strcat(s, "TCP: ["); 3900 sp = s + strlen(s); 3901 3902 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3903 inet_ntoa_r(inc->inc_faddr, sp); 3904 sp = s + strlen(s); 3905 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3906 sp = s + strlen(s); 3907 inet_ntoa_r(inc->inc_laddr, sp); 3908 sp = s + strlen(s); 3909 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3910 #ifdef INET6 3911 } else if (inc) { 3912 ip6_sprintf(sp, &inc->inc6_faddr); 3913 sp = s + strlen(s); 3914 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3915 sp = s + strlen(s); 3916 ip6_sprintf(sp, &inc->inc6_laddr); 3917 sp = s + strlen(s); 3918 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3919 } else if (ip6 && th) { 3920 ip6_sprintf(sp, &ip6->ip6_src); 3921 sp = s + strlen(s); 3922 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3923 sp = s + strlen(s); 3924 ip6_sprintf(sp, &ip6->ip6_dst); 3925 sp = s + strlen(s); 3926 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3927 #endif /* INET6 */ 3928 #ifdef INET 3929 } else if (ip && th) { 3930 inet_ntoa_r(ip->ip_src, sp); 3931 sp = s + strlen(s); 3932 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3933 sp = s + strlen(s); 3934 inet_ntoa_r(ip->ip_dst, sp); 3935 sp = s + strlen(s); 3936 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3937 #endif /* INET */ 3938 } else { 3939 free(s, M_TCPLOG); 3940 return (NULL); 3941 } 3942 sp = s + strlen(s); 3943 if (th) 3944 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3945 if (*(s + size - 1) != '\0') 3946 panic("%s: string too long", __func__); 3947 return (s); 3948 } 3949 3950 /* 3951 * A subroutine which makes it easy to track TCP state changes with DTrace. 3952 * This function shouldn't be called for t_state initializations that don't 3953 * correspond to actual TCP state transitions. 3954 */ 3955 void 3956 tcp_state_change(struct tcpcb *tp, int newstate) 3957 { 3958 #if defined(KDTRACE_HOOKS) 3959 int pstate = tp->t_state; 3960 #endif 3961 3962 TCPSTATES_DEC(tp->t_state); 3963 TCPSTATES_INC(newstate); 3964 tp->t_state = newstate; 3965 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3966 } 3967 3968 /* 3969 * Create an external-format (``xtcpcb'') structure using the information in 3970 * the kernel-format tcpcb structure pointed to by tp. This is done to 3971 * reduce the spew of irrelevant information over this interface, to isolate 3972 * user code from changes in the kernel structure, and potentially to provide 3973 * information-hiding if we decide that some of this information should be 3974 * hidden from users. 3975 */ 3976 void 3977 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3978 { 3979 struct tcpcb *tp = intotcpcb(inp); 3980 struct tcptw *tw = intotw(inp); 3981 sbintime_t now; 3982 3983 bzero(xt, sizeof(*xt)); 3984 if (inp->inp_flags & INP_TIMEWAIT) { 3985 xt->t_state = TCPS_TIME_WAIT; 3986 xt->xt_encaps_port = tw->t_port; 3987 } else { 3988 xt->t_state = tp->t_state; 3989 xt->t_logstate = tp->t_logstate; 3990 xt->t_flags = tp->t_flags; 3991 xt->t_sndzerowin = tp->t_sndzerowin; 3992 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3993 xt->t_rcvoopack = tp->t_rcvoopack; 3994 xt->t_rcv_wnd = tp->rcv_wnd; 3995 xt->t_snd_wnd = tp->snd_wnd; 3996 xt->t_snd_cwnd = tp->snd_cwnd; 3997 xt->t_snd_ssthresh = tp->snd_ssthresh; 3998 xt->t_maxseg = tp->t_maxseg; 3999 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4000 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4001 4002 now = getsbinuptime(); 4003 #define COPYTIMER(ttt) do { \ 4004 if (callout_active(&tp->t_timers->ttt)) \ 4005 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4006 SBT_1MS; \ 4007 else \ 4008 xt->ttt = 0; \ 4009 } while (0) 4010 COPYTIMER(tt_delack); 4011 COPYTIMER(tt_rexmt); 4012 COPYTIMER(tt_persist); 4013 COPYTIMER(tt_keep); 4014 COPYTIMER(tt_2msl); 4015 #undef COPYTIMER 4016 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4017 4018 xt->xt_encaps_port = tp->t_port; 4019 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4020 TCP_FUNCTION_NAME_LEN_MAX); 4021 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4022 TCP_CA_NAME_MAX); 4023 #ifdef TCP_BLACKBOX 4024 (void)tcp_log_get_id(tp, xt->xt_logid); 4025 #endif 4026 } 4027 4028 xt->xt_len = sizeof(struct xtcpcb); 4029 in_pcbtoxinpcb(inp, &xt->xt_inp); 4030 if (inp->inp_socket == NULL) 4031 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4032 } 4033 4034 void 4035 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4036 { 4037 uint32_t bit, i; 4038 4039 if ((tp == NULL) || 4040 (status > TCP_EI_STATUS_MAX_VALUE) || 4041 (status == 0)) { 4042 /* Invalid */ 4043 return; 4044 } 4045 if (status > (sizeof(uint32_t) * 8)) { 4046 /* Should this be a KASSERT? */ 4047 return; 4048 } 4049 bit = 1U << (status - 1); 4050 if (bit & tp->t_end_info_status) { 4051 /* already logged */ 4052 return; 4053 } 4054 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4055 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4056 tp->t_end_info_bytes[i] = status; 4057 tp->t_end_info_status |= bit; 4058 break; 4059 } 4060 } 4061 } 4062 4063 int 4064 tcp_can_enable_pacing(void) 4065 { 4066 4067 if ((tcp_pacing_limit == -1) || 4068 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4069 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4070 shadow_num_connections = number_of_tcp_connections_pacing; 4071 return (1); 4072 } else { 4073 return (0); 4074 } 4075 } 4076 4077 static uint8_t tcp_pacing_warning = 0; 4078 4079 void 4080 tcp_decrement_paced_conn(void) 4081 { 4082 uint32_t ret; 4083 4084 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4085 shadow_num_connections = number_of_tcp_connections_pacing; 4086 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4087 if (ret == 0) { 4088 if (tcp_pacing_limit != -1) { 4089 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4090 tcp_pacing_limit = 0; 4091 } else if (tcp_pacing_warning == 0) { 4092 printf("Warning pacing count is invalid, invalid decrement\n"); 4093 tcp_pacing_warning = 1; 4094 } 4095 } 4096 } 4097