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 /* 272 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 273 * Some stacks negotiate TS, but never send them after connection setup. Some 274 * stacks negotiate TS, but don't send them when sending keep-alive segments. 275 * These include modern widely deployed TCP stacks. 276 * Therefore tolerating violations for now... 277 */ 278 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 280 &VNET_NAME(tcp_tolerate_missing_ts), 0, 281 "Tolerate missing TCP timestamps"); 282 283 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 284 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 285 &VNET_NAME(tcp_ts_offset_per_conn), 0, 286 "Initialize TCP timestamps per connection instead of per host pair"); 287 288 /* How many connections are pacing */ 289 static volatile uint32_t number_of_tcp_connections_pacing = 0; 290 static uint32_t shadow_num_connections = 0; 291 292 static int tcp_pacing_limit = 10000; 293 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 294 &tcp_pacing_limit, 1000, 295 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 296 297 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 298 &shadow_num_connections, 0, "Number of TCP connections being paced"); 299 300 static int tcp_log_debug = 0; 301 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 302 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 303 304 static int tcp_tcbhashsize; 305 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 306 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 307 308 static int do_tcpdrain = 1; 309 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 310 "Enable tcp_drain routine for extra help when low on mbufs"); 311 312 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 313 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 314 315 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 316 #define V_icmp_may_rst VNET(icmp_may_rst) 317 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 318 &VNET_NAME(icmp_may_rst), 0, 319 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 320 321 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 322 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 323 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 324 &VNET_NAME(tcp_isn_reseed_interval), 0, 325 "Seconds between reseeding of ISN secret"); 326 327 static int tcp_soreceive_stream; 328 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 329 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 330 331 VNET_DEFINE(uma_zone_t, sack_hole_zone); 332 #define V_sack_hole_zone VNET(sack_hole_zone) 333 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 334 static int 335 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 336 { 337 int error; 338 uint32_t new; 339 340 new = V_tcp_map_entries_limit; 341 error = sysctl_handle_int(oidp, &new, 0, req); 342 if (error == 0 && req->newptr) { 343 /* only allow "0" and value > minimum */ 344 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 345 error = EINVAL; 346 else 347 V_tcp_map_entries_limit = new; 348 } 349 return (error); 350 } 351 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 352 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 353 &VNET_NAME(tcp_map_entries_limit), 0, 354 &sysctl_net_inet_tcp_map_limit_check, "IU", 355 "Total sendmap entries limit"); 356 357 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 358 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 359 &VNET_NAME(tcp_map_split_limit), 0, 360 "Total sendmap split entries limit"); 361 362 #ifdef TCP_HHOOK 363 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 364 #endif 365 366 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 367 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 368 #define V_ts_offset_secret VNET(ts_offset_secret) 369 370 static int tcp_default_fb_init(struct tcpcb *tp); 371 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 372 static int tcp_default_handoff_ok(struct tcpcb *tp); 373 static struct inpcb *tcp_notify(struct inpcb *, int); 374 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 375 static void tcp_mtudisc(struct inpcb *, int); 376 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 377 void *ip4hdr, const void *ip6hdr); 378 379 static struct tcp_function_block tcp_def_funcblk = { 380 .tfb_tcp_block_name = "freebsd", 381 .tfb_tcp_output = tcp_output, 382 .tfb_tcp_do_segment = tcp_do_segment, 383 .tfb_tcp_ctloutput = tcp_default_ctloutput, 384 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 385 .tfb_tcp_fb_init = tcp_default_fb_init, 386 .tfb_tcp_fb_fini = tcp_default_fb_fini, 387 }; 388 389 static int tcp_fb_cnt = 0; 390 struct tcp_funchead t_functions; 391 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 392 393 static struct tcp_function_block * 394 find_tcp_functions_locked(struct tcp_function_set *fs) 395 { 396 struct tcp_function *f; 397 struct tcp_function_block *blk=NULL; 398 399 TAILQ_FOREACH(f, &t_functions, tf_next) { 400 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 401 blk = f->tf_fb; 402 break; 403 } 404 } 405 return(blk); 406 } 407 408 static struct tcp_function_block * 409 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 410 { 411 struct tcp_function_block *rblk=NULL; 412 struct tcp_function *f; 413 414 TAILQ_FOREACH(f, &t_functions, tf_next) { 415 if (f->tf_fb == blk) { 416 rblk = blk; 417 if (s) { 418 *s = f; 419 } 420 break; 421 } 422 } 423 return (rblk); 424 } 425 426 struct tcp_function_block * 427 find_and_ref_tcp_functions(struct tcp_function_set *fs) 428 { 429 struct tcp_function_block *blk; 430 431 rw_rlock(&tcp_function_lock); 432 blk = find_tcp_functions_locked(fs); 433 if (blk) 434 refcount_acquire(&blk->tfb_refcnt); 435 rw_runlock(&tcp_function_lock); 436 return(blk); 437 } 438 439 struct tcp_function_block * 440 find_and_ref_tcp_fb(struct tcp_function_block *blk) 441 { 442 struct tcp_function_block *rblk; 443 444 rw_rlock(&tcp_function_lock); 445 rblk = find_tcp_fb_locked(blk, NULL); 446 if (rblk) 447 refcount_acquire(&rblk->tfb_refcnt); 448 rw_runlock(&tcp_function_lock); 449 return(rblk); 450 } 451 452 static struct tcp_function_block * 453 find_and_ref_tcp_default_fb(void) 454 { 455 struct tcp_function_block *rblk; 456 457 rw_rlock(&tcp_function_lock); 458 rblk = tcp_func_set_ptr; 459 refcount_acquire(&rblk->tfb_refcnt); 460 rw_runlock(&tcp_function_lock); 461 return (rblk); 462 } 463 464 void 465 tcp_switch_back_to_default(struct tcpcb *tp) 466 { 467 struct tcp_function_block *tfb; 468 469 KASSERT(tp->t_fb != &tcp_def_funcblk, 470 ("%s: called by the built-in default stack", __func__)); 471 472 /* 473 * Release the old stack. This function will either find a new one 474 * or panic. 475 */ 476 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 477 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 478 refcount_release(&tp->t_fb->tfb_refcnt); 479 480 /* 481 * Now, we'll find a new function block to use. 482 * Start by trying the current user-selected 483 * default, unless this stack is the user-selected 484 * default. 485 */ 486 tfb = find_and_ref_tcp_default_fb(); 487 if (tfb == tp->t_fb) { 488 refcount_release(&tfb->tfb_refcnt); 489 tfb = NULL; 490 } 491 /* Does the stack accept this connection? */ 492 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 493 (*tfb->tfb_tcp_handoff_ok)(tp)) { 494 refcount_release(&tfb->tfb_refcnt); 495 tfb = NULL; 496 } 497 /* Try to use that stack. */ 498 if (tfb != NULL) { 499 /* Initialize the new stack. If it succeeds, we are done. */ 500 tp->t_fb = tfb; 501 if (tp->t_fb->tfb_tcp_fb_init == NULL || 502 (*tp->t_fb->tfb_tcp_fb_init)(tp) == 0) 503 return; 504 505 /* 506 * Initialization failed. Release the reference count on 507 * the stack. 508 */ 509 refcount_release(&tfb->tfb_refcnt); 510 } 511 512 /* 513 * If that wasn't feasible, use the built-in default 514 * stack which is not allowed to reject anyone. 515 */ 516 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 517 if (tfb == NULL) { 518 /* there always should be a default */ 519 panic("Can't refer to tcp_def_funcblk"); 520 } 521 if (tfb->tfb_tcp_handoff_ok != NULL) { 522 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 523 /* The default stack cannot say no */ 524 panic("Default stack rejects a new session?"); 525 } 526 } 527 tp->t_fb = tfb; 528 if (tp->t_fb->tfb_tcp_fb_init != NULL && 529 (*tp->t_fb->tfb_tcp_fb_init)(tp)) { 530 /* The default stack cannot fail */ 531 panic("Default stack initialization failed"); 532 } 533 } 534 535 static void 536 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 537 const struct sockaddr *sa, void *ctx) 538 { 539 struct ip *iph; 540 #ifdef INET6 541 struct ip6_hdr *ip6; 542 #endif 543 struct udphdr *uh; 544 struct tcphdr *th; 545 int thlen; 546 uint16_t port; 547 548 TCPSTAT_INC(tcps_tunneled_pkts); 549 if ((m->m_flags & M_PKTHDR) == 0) { 550 /* Can't handle one that is not a pkt hdr */ 551 TCPSTAT_INC(tcps_tunneled_errs); 552 goto out; 553 } 554 thlen = sizeof(struct tcphdr); 555 if (m->m_len < off + sizeof(struct udphdr) + thlen && 556 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 557 TCPSTAT_INC(tcps_tunneled_errs); 558 goto out; 559 } 560 iph = mtod(m, struct ip *); 561 uh = (struct udphdr *)((caddr_t)iph + off); 562 th = (struct tcphdr *)(uh + 1); 563 thlen = th->th_off << 2; 564 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 565 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 566 if (m == NULL) { 567 TCPSTAT_INC(tcps_tunneled_errs); 568 goto out; 569 } else { 570 iph = mtod(m, struct ip *); 571 uh = (struct udphdr *)((caddr_t)iph + off); 572 th = (struct tcphdr *)(uh + 1); 573 } 574 } 575 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 576 bcopy(th, uh, m->m_len - off); 577 m->m_len -= sizeof(struct udphdr); 578 m->m_pkthdr.len -= sizeof(struct udphdr); 579 /* 580 * We use the same algorithm for 581 * both UDP and TCP for c-sum. So 582 * the code in tcp_input will skip 583 * the checksum. So we do nothing 584 * with the flag (m->m_pkthdr.csum_flags). 585 */ 586 switch (iph->ip_v) { 587 #ifdef INET 588 case IPVERSION: 589 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 590 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 591 break; 592 #endif 593 #ifdef INET6 594 case IPV6_VERSION >> 4: 595 ip6 = mtod(m, struct ip6_hdr *); 596 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 597 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 598 break; 599 #endif 600 default: 601 goto out; 602 break; 603 } 604 return; 605 out: 606 m_freem(m); 607 } 608 609 static int 610 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 611 { 612 int error=ENOENT; 613 struct tcp_function_set fs; 614 struct tcp_function_block *blk; 615 616 memset(&fs, 0, sizeof(fs)); 617 rw_rlock(&tcp_function_lock); 618 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 619 if (blk) { 620 /* Found him */ 621 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 622 fs.pcbcnt = blk->tfb_refcnt; 623 } 624 rw_runlock(&tcp_function_lock); 625 error = sysctl_handle_string(oidp, fs.function_set_name, 626 sizeof(fs.function_set_name), req); 627 628 /* Check for error or no change */ 629 if (error != 0 || req->newptr == NULL) 630 return(error); 631 632 rw_wlock(&tcp_function_lock); 633 blk = find_tcp_functions_locked(&fs); 634 if ((blk == NULL) || 635 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 636 error = ENOENT; 637 goto done; 638 } 639 tcp_func_set_ptr = blk; 640 done: 641 rw_wunlock(&tcp_function_lock); 642 return (error); 643 } 644 645 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 646 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 647 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 648 "Set/get the default TCP functions"); 649 650 static int 651 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 652 { 653 int error, cnt, linesz; 654 struct tcp_function *f; 655 char *buffer, *cp; 656 size_t bufsz, outsz; 657 bool alias; 658 659 cnt = 0; 660 rw_rlock(&tcp_function_lock); 661 TAILQ_FOREACH(f, &t_functions, tf_next) { 662 cnt++; 663 } 664 rw_runlock(&tcp_function_lock); 665 666 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 667 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 668 669 error = 0; 670 cp = buffer; 671 672 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 673 "Alias", "PCB count"); 674 cp += linesz; 675 bufsz -= linesz; 676 outsz = linesz; 677 678 rw_rlock(&tcp_function_lock); 679 TAILQ_FOREACH(f, &t_functions, tf_next) { 680 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 681 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 682 f->tf_fb->tfb_tcp_block_name, 683 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 684 alias ? f->tf_name : "-", 685 f->tf_fb->tfb_refcnt); 686 if (linesz >= bufsz) { 687 error = EOVERFLOW; 688 break; 689 } 690 cp += linesz; 691 bufsz -= linesz; 692 outsz += linesz; 693 } 694 rw_runlock(&tcp_function_lock); 695 if (error == 0) 696 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 697 free(buffer, M_TEMP); 698 return (error); 699 } 700 701 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 702 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 703 NULL, 0, sysctl_net_inet_list_available, "A", 704 "list available TCP Function sets"); 705 706 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 707 708 #ifdef INET 709 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 710 #define V_udp4_tun_socket VNET(udp4_tun_socket) 711 #endif 712 #ifdef INET6 713 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 714 #define V_udp6_tun_socket VNET(udp6_tun_socket) 715 #endif 716 717 static void 718 tcp_over_udp_stop(void) 719 { 720 /* 721 * This function assumes sysctl caller holds inp_rinfo_lock() 722 * for writting! 723 */ 724 #ifdef INET 725 if (V_udp4_tun_socket != NULL) { 726 soclose(V_udp4_tun_socket); 727 V_udp4_tun_socket = NULL; 728 } 729 #endif 730 #ifdef INET6 731 if (V_udp6_tun_socket != NULL) { 732 soclose(V_udp6_tun_socket); 733 V_udp6_tun_socket = NULL; 734 } 735 #endif 736 } 737 738 static int 739 tcp_over_udp_start(void) 740 { 741 uint16_t port; 742 int ret; 743 #ifdef INET 744 struct sockaddr_in sin; 745 #endif 746 #ifdef INET6 747 struct sockaddr_in6 sin6; 748 #endif 749 /* 750 * This function assumes sysctl caller holds inp_info_rlock() 751 * for writting! 752 */ 753 port = V_tcp_udp_tunneling_port; 754 if (ntohs(port) == 0) { 755 /* Must have a port set */ 756 return (EINVAL); 757 } 758 #ifdef INET 759 if (V_udp4_tun_socket != NULL) { 760 /* Already running -- must stop first */ 761 return (EALREADY); 762 } 763 #endif 764 #ifdef INET6 765 if (V_udp6_tun_socket != NULL) { 766 /* Already running -- must stop first */ 767 return (EALREADY); 768 } 769 #endif 770 #ifdef INET 771 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 772 SOCK_DGRAM, IPPROTO_UDP, 773 curthread->td_ucred, curthread))) { 774 tcp_over_udp_stop(); 775 return (ret); 776 } 777 /* Call the special UDP hook. */ 778 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 779 tcp_recv_udp_tunneled_packet, 780 tcp_ctlinput_viaudp, 781 NULL))) { 782 tcp_over_udp_stop(); 783 return (ret); 784 } 785 /* Ok, we have a socket, bind it to the port. */ 786 memset(&sin, 0, sizeof(struct sockaddr_in)); 787 sin.sin_len = sizeof(struct sockaddr_in); 788 sin.sin_family = AF_INET; 789 sin.sin_port = htons(port); 790 if ((ret = sobind(V_udp4_tun_socket, 791 (struct sockaddr *)&sin, curthread))) { 792 tcp_over_udp_stop(); 793 return (ret); 794 } 795 #endif 796 #ifdef INET6 797 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 798 SOCK_DGRAM, IPPROTO_UDP, 799 curthread->td_ucred, curthread))) { 800 tcp_over_udp_stop(); 801 return (ret); 802 } 803 /* Call the special UDP hook. */ 804 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 805 tcp_recv_udp_tunneled_packet, 806 tcp6_ctlinput_viaudp, 807 NULL))) { 808 tcp_over_udp_stop(); 809 return (ret); 810 } 811 /* Ok, we have a socket, bind it to the port. */ 812 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 813 sin6.sin6_len = sizeof(struct sockaddr_in6); 814 sin6.sin6_family = AF_INET6; 815 sin6.sin6_port = htons(port); 816 if ((ret = sobind(V_udp6_tun_socket, 817 (struct sockaddr *)&sin6, curthread))) { 818 tcp_over_udp_stop(); 819 return (ret); 820 } 821 #endif 822 return (0); 823 } 824 825 static int 826 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 827 { 828 int error; 829 uint32_t old, new; 830 831 old = V_tcp_udp_tunneling_port; 832 new = old; 833 error = sysctl_handle_int(oidp, &new, 0, req); 834 if ((error == 0) && 835 (req->newptr != NULL)) { 836 if ((new < TCP_TUNNELING_PORT_MIN) || 837 (new > TCP_TUNNELING_PORT_MAX)) { 838 error = EINVAL; 839 } else { 840 V_tcp_udp_tunneling_port = new; 841 if (old != 0) { 842 tcp_over_udp_stop(); 843 } 844 if (new != 0) { 845 error = tcp_over_udp_start(); 846 } 847 } 848 } 849 return (error); 850 } 851 852 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 853 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 854 &VNET_NAME(tcp_udp_tunneling_port), 855 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 856 "Tunneling port for tcp over udp"); 857 858 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 859 860 static int 861 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 862 { 863 int error, new; 864 865 new = V_tcp_udp_tunneling_overhead; 866 error = sysctl_handle_int(oidp, &new, 0, req); 867 if (error == 0 && req->newptr) { 868 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 869 (new > TCP_TUNNELING_OVERHEAD_MAX)) 870 error = EINVAL; 871 else 872 V_tcp_udp_tunneling_overhead = new; 873 } 874 return (error); 875 } 876 877 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 878 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 879 &VNET_NAME(tcp_udp_tunneling_overhead), 880 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 881 "MSS reduction when using tcp over udp"); 882 883 /* 884 * Exports one (struct tcp_function_info) for each alias/name. 885 */ 886 static int 887 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 888 { 889 int cnt, error; 890 struct tcp_function *f; 891 struct tcp_function_info tfi; 892 893 /* 894 * We don't allow writes. 895 */ 896 if (req->newptr != NULL) 897 return (EINVAL); 898 899 /* 900 * Wire the old buffer so we can directly copy the functions to 901 * user space without dropping the lock. 902 */ 903 if (req->oldptr != NULL) { 904 error = sysctl_wire_old_buffer(req, 0); 905 if (error) 906 return (error); 907 } 908 909 /* 910 * Walk the list and copy out matching entries. If INVARIANTS 911 * is compiled in, also walk the list to verify the length of 912 * the list matches what we have recorded. 913 */ 914 rw_rlock(&tcp_function_lock); 915 916 cnt = 0; 917 #ifndef INVARIANTS 918 if (req->oldptr == NULL) { 919 cnt = tcp_fb_cnt; 920 goto skip_loop; 921 } 922 #endif 923 TAILQ_FOREACH(f, &t_functions, tf_next) { 924 #ifdef INVARIANTS 925 cnt++; 926 #endif 927 if (req->oldptr != NULL) { 928 bzero(&tfi, sizeof(tfi)); 929 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 930 tfi.tfi_id = f->tf_fb->tfb_id; 931 (void)strlcpy(tfi.tfi_alias, f->tf_name, 932 sizeof(tfi.tfi_alias)); 933 (void)strlcpy(tfi.tfi_name, 934 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 935 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 936 /* 937 * Don't stop on error, as that is the 938 * mechanism we use to accumulate length 939 * information if the buffer was too short. 940 */ 941 } 942 } 943 KASSERT(cnt == tcp_fb_cnt, 944 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 945 #ifndef INVARIANTS 946 skip_loop: 947 #endif 948 rw_runlock(&tcp_function_lock); 949 if (req->oldptr == NULL) 950 error = SYSCTL_OUT(req, NULL, 951 (cnt + 1) * sizeof(struct tcp_function_info)); 952 953 return (error); 954 } 955 956 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 957 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 958 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 959 "List TCP function block name-to-ID mappings"); 960 961 /* 962 * tfb_tcp_handoff_ok() function for the default stack. 963 * Note that we'll basically try to take all comers. 964 */ 965 static int 966 tcp_default_handoff_ok(struct tcpcb *tp) 967 { 968 969 return (0); 970 } 971 972 /* 973 * tfb_tcp_fb_init() function for the default stack. 974 * 975 * This handles making sure we have appropriate timers set if you are 976 * transitioning a socket that has some amount of setup done. 977 * 978 * The init() fuction from the default can *never* return non-zero i.e. 979 * it is required to always succeed since it is the stack of last resort! 980 */ 981 static int 982 tcp_default_fb_init(struct tcpcb *tp) 983 { 984 985 struct socket *so; 986 987 INP_WLOCK_ASSERT(tp->t_inpcb); 988 989 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 990 ("%s: connection %p in unexpected state %d", __func__, tp, 991 tp->t_state)); 992 993 /* 994 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 995 * know what to do for unexpected states (which includes TIME_WAIT). 996 */ 997 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 998 return (0); 999 1000 /* 1001 * Make sure some kind of transmission timer is set if there is 1002 * outstanding data. 1003 */ 1004 so = tp->t_inpcb->inp_socket; 1005 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1006 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1007 tcp_timer_active(tp, TT_PERSIST))) { 1008 /* 1009 * If the session has established and it looks like it should 1010 * be in the persist state, set the persist timer. Otherwise, 1011 * set the retransmit timer. 1012 */ 1013 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1014 (int32_t)(tp->snd_nxt - tp->snd_una) < 1015 (int32_t)sbavail(&so->so_snd)) 1016 tcp_setpersist(tp); 1017 else 1018 tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); 1019 } 1020 1021 /* All non-embryonic sessions get a keepalive timer. */ 1022 if (!tcp_timer_active(tp, TT_KEEP)) 1023 tcp_timer_activate(tp, TT_KEEP, 1024 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1025 TP_KEEPINIT(tp)); 1026 1027 /* 1028 * Make sure critical variables are initialized 1029 * if transitioning while in Recovery. 1030 */ 1031 if IN_FASTRECOVERY(tp->t_flags) { 1032 if (tp->sackhint.recover_fs == 0) 1033 tp->sackhint.recover_fs = max(1, 1034 tp->snd_nxt - tp->snd_una); 1035 } 1036 1037 return (0); 1038 } 1039 1040 /* 1041 * tfb_tcp_fb_fini() function for the default stack. 1042 * 1043 * This changes state as necessary (or prudent) to prepare for another stack 1044 * to assume responsibility for the connection. 1045 */ 1046 static void 1047 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1048 { 1049 1050 INP_WLOCK_ASSERT(tp->t_inpcb); 1051 return; 1052 } 1053 1054 /* 1055 * Target size of TCP PCB hash tables. Must be a power of two. 1056 * 1057 * Note that this can be overridden by the kernel environment 1058 * variable net.inet.tcp.tcbhashsize 1059 */ 1060 #ifndef TCBHASHSIZE 1061 #define TCBHASHSIZE 0 1062 #endif 1063 1064 /* 1065 * XXX 1066 * Callouts should be moved into struct tcp directly. They are currently 1067 * separate because the tcpcb structure is exported to userland for sysctl 1068 * parsing purposes, which do not know about callouts. 1069 */ 1070 struct tcpcb_mem { 1071 struct tcpcb tcb; 1072 struct tcp_timer tt; 1073 struct cc_var ccv; 1074 #ifdef TCP_HHOOK 1075 struct osd osd; 1076 #endif 1077 }; 1078 1079 VNET_DEFINE_STATIC(uma_zone_t, tcpcb_zone); 1080 #define V_tcpcb_zone VNET(tcpcb_zone) 1081 1082 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1083 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1084 1085 static struct mtx isn_mtx; 1086 1087 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1088 #define ISN_LOCK() mtx_lock(&isn_mtx) 1089 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1090 1091 /* 1092 * TCP initialization. 1093 */ 1094 static void 1095 tcp_zone_change(void *tag) 1096 { 1097 1098 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 1099 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1100 tcp_tw_zone_change(); 1101 } 1102 1103 static int 1104 tcp_inpcb_init(void *mem, int size, int flags) 1105 { 1106 struct inpcb *inp = mem; 1107 1108 INP_LOCK_INIT(inp, "inp", "tcpinp"); 1109 return (0); 1110 } 1111 1112 /* 1113 * Take a value and get the next power of 2 that doesn't overflow. 1114 * Used to size the tcp_inpcb hash buckets. 1115 */ 1116 static int 1117 maketcp_hashsize(int size) 1118 { 1119 int hashsize; 1120 1121 /* 1122 * auto tune. 1123 * get the next power of 2 higher than maxsockets. 1124 */ 1125 hashsize = 1 << fls(size); 1126 /* catch overflow, and just go one power of 2 smaller */ 1127 if (hashsize < size) { 1128 hashsize = 1 << (fls(size) - 1); 1129 } 1130 return (hashsize); 1131 } 1132 1133 static volatile int next_tcp_stack_id = 1; 1134 1135 /* 1136 * Register a TCP function block with the name provided in the names 1137 * array. (Note that this function does NOT automatically register 1138 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1139 * explicitly include blk->tfb_tcp_block_name in the list of names if 1140 * you wish to register the stack with that name.) 1141 * 1142 * Either all name registrations will succeed or all will fail. If 1143 * a name registration fails, the function will update the num_names 1144 * argument to point to the array index of the name that encountered 1145 * the failure. 1146 * 1147 * Returns 0 on success, or an error code on failure. 1148 */ 1149 int 1150 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1151 const char *names[], int *num_names) 1152 { 1153 struct tcp_function *n; 1154 struct tcp_function_set fs; 1155 int error, i; 1156 1157 KASSERT(names != NULL && *num_names > 0, 1158 ("%s: Called with 0-length name list", __func__)); 1159 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1160 KASSERT(rw_initialized(&tcp_function_lock), 1161 ("%s: called too early", __func__)); 1162 1163 if ((blk->tfb_tcp_output == NULL) || 1164 (blk->tfb_tcp_do_segment == NULL) || 1165 (blk->tfb_tcp_ctloutput == NULL) || 1166 (strlen(blk->tfb_tcp_block_name) == 0)) { 1167 /* 1168 * These functions are required and you 1169 * need a name. 1170 */ 1171 *num_names = 0; 1172 return (EINVAL); 1173 } 1174 if (blk->tfb_tcp_timer_stop_all || 1175 blk->tfb_tcp_timer_activate || 1176 blk->tfb_tcp_timer_active || 1177 blk->tfb_tcp_timer_stop) { 1178 /* 1179 * If you define one timer function you 1180 * must have them all. 1181 */ 1182 if ((blk->tfb_tcp_timer_stop_all == NULL) || 1183 (blk->tfb_tcp_timer_activate == NULL) || 1184 (blk->tfb_tcp_timer_active == NULL) || 1185 (blk->tfb_tcp_timer_stop == NULL)) { 1186 *num_names = 0; 1187 return (EINVAL); 1188 } 1189 } 1190 1191 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1192 *num_names = 0; 1193 return (EINVAL); 1194 } 1195 1196 refcount_init(&blk->tfb_refcnt, 0); 1197 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1198 for (i = 0; i < *num_names; i++) { 1199 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1200 if (n == NULL) { 1201 error = ENOMEM; 1202 goto cleanup; 1203 } 1204 n->tf_fb = blk; 1205 1206 (void)strlcpy(fs.function_set_name, names[i], 1207 sizeof(fs.function_set_name)); 1208 rw_wlock(&tcp_function_lock); 1209 if (find_tcp_functions_locked(&fs) != NULL) { 1210 /* Duplicate name space not allowed */ 1211 rw_wunlock(&tcp_function_lock); 1212 free(n, M_TCPFUNCTIONS); 1213 error = EALREADY; 1214 goto cleanup; 1215 } 1216 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1217 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1218 tcp_fb_cnt++; 1219 rw_wunlock(&tcp_function_lock); 1220 } 1221 return(0); 1222 1223 cleanup: 1224 /* 1225 * Deregister the names we just added. Because registration failed 1226 * for names[i], we don't need to deregister that name. 1227 */ 1228 *num_names = i; 1229 rw_wlock(&tcp_function_lock); 1230 while (--i >= 0) { 1231 TAILQ_FOREACH(n, &t_functions, tf_next) { 1232 if (!strncmp(n->tf_name, names[i], 1233 TCP_FUNCTION_NAME_LEN_MAX)) { 1234 TAILQ_REMOVE(&t_functions, n, tf_next); 1235 tcp_fb_cnt--; 1236 n->tf_fb = NULL; 1237 free(n, M_TCPFUNCTIONS); 1238 break; 1239 } 1240 } 1241 } 1242 rw_wunlock(&tcp_function_lock); 1243 return (error); 1244 } 1245 1246 /* 1247 * Register a TCP function block using the name provided in the name 1248 * argument. 1249 * 1250 * Returns 0 on success, or an error code on failure. 1251 */ 1252 int 1253 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1254 int wait) 1255 { 1256 const char *name_list[1]; 1257 int num_names, rv; 1258 1259 num_names = 1; 1260 if (name != NULL) 1261 name_list[0] = name; 1262 else 1263 name_list[0] = blk->tfb_tcp_block_name; 1264 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1265 return (rv); 1266 } 1267 1268 /* 1269 * Register a TCP function block using the name defined in 1270 * blk->tfb_tcp_block_name. 1271 * 1272 * Returns 0 on success, or an error code on failure. 1273 */ 1274 int 1275 register_tcp_functions(struct tcp_function_block *blk, int wait) 1276 { 1277 1278 return (register_tcp_functions_as_name(blk, NULL, wait)); 1279 } 1280 1281 /* 1282 * Deregister all names associated with a function block. This 1283 * functionally removes the function block from use within the system. 1284 * 1285 * When called with a true quiesce argument, mark the function block 1286 * as being removed so no more stacks will use it and determine 1287 * whether the removal would succeed. 1288 * 1289 * When called with a false quiesce argument, actually attempt the 1290 * removal. 1291 * 1292 * When called with a force argument, attempt to switch all TCBs to 1293 * use the default stack instead of returning EBUSY. 1294 * 1295 * Returns 0 on success (or if the removal would succeed, or an error 1296 * code on failure. 1297 */ 1298 int 1299 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1300 bool force) 1301 { 1302 struct tcp_function *f; 1303 1304 if (blk == &tcp_def_funcblk) { 1305 /* You can't un-register the default */ 1306 return (EPERM); 1307 } 1308 rw_wlock(&tcp_function_lock); 1309 if (blk == tcp_func_set_ptr) { 1310 /* You can't free the current default */ 1311 rw_wunlock(&tcp_function_lock); 1312 return (EBUSY); 1313 } 1314 /* Mark the block so no more stacks can use it. */ 1315 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1316 /* 1317 * If TCBs are still attached to the stack, attempt to switch them 1318 * to the default stack. 1319 */ 1320 if (force && blk->tfb_refcnt) { 1321 struct inpcb *inp; 1322 struct tcpcb *tp; 1323 VNET_ITERATOR_DECL(vnet_iter); 1324 1325 rw_wunlock(&tcp_function_lock); 1326 1327 VNET_LIST_RLOCK(); 1328 VNET_FOREACH(vnet_iter) { 1329 CURVNET_SET(vnet_iter); 1330 INP_INFO_WLOCK(&V_tcbinfo); 1331 CK_LIST_FOREACH(inp, V_tcbinfo.ipi_listhead, inp_list) { 1332 INP_WLOCK(inp); 1333 if (inp->inp_flags & INP_TIMEWAIT) { 1334 INP_WUNLOCK(inp); 1335 continue; 1336 } 1337 tp = intotcpcb(inp); 1338 if (tp == NULL || tp->t_fb != blk) { 1339 INP_WUNLOCK(inp); 1340 continue; 1341 } 1342 tcp_switch_back_to_default(tp); 1343 INP_WUNLOCK(inp); 1344 } 1345 INP_INFO_WUNLOCK(&V_tcbinfo); 1346 CURVNET_RESTORE(); 1347 } 1348 VNET_LIST_RUNLOCK(); 1349 1350 rw_wlock(&tcp_function_lock); 1351 } 1352 if (blk->tfb_refcnt) { 1353 /* TCBs still attached. */ 1354 rw_wunlock(&tcp_function_lock); 1355 return (EBUSY); 1356 } 1357 if (quiesce) { 1358 /* Skip removal. */ 1359 rw_wunlock(&tcp_function_lock); 1360 return (0); 1361 } 1362 /* Remove any function names that map to this function block. */ 1363 while (find_tcp_fb_locked(blk, &f) != NULL) { 1364 TAILQ_REMOVE(&t_functions, f, tf_next); 1365 tcp_fb_cnt--; 1366 f->tf_fb = NULL; 1367 free(f, M_TCPFUNCTIONS); 1368 } 1369 rw_wunlock(&tcp_function_lock); 1370 return (0); 1371 } 1372 1373 void 1374 tcp_init(void) 1375 { 1376 const char *tcbhash_tuneable; 1377 int hashsize; 1378 1379 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1380 1381 #ifdef TCP_HHOOK 1382 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1383 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1384 printf("%s: WARNING: unable to register helper hook\n", __func__); 1385 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1386 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1387 printf("%s: WARNING: unable to register helper hook\n", __func__); 1388 #endif 1389 #ifdef STATS 1390 if (tcp_stats_init()) 1391 printf("%s: WARNING: unable to initialise TCP stats\n", 1392 __func__); 1393 #endif 1394 hashsize = TCBHASHSIZE; 1395 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1396 if (hashsize == 0) { 1397 /* 1398 * Auto tune the hash size based on maxsockets. 1399 * A perfect hash would have a 1:1 mapping 1400 * (hashsize = maxsockets) however it's been 1401 * suggested that O(2) average is better. 1402 */ 1403 hashsize = maketcp_hashsize(maxsockets / 4); 1404 /* 1405 * Our historical default is 512, 1406 * do not autotune lower than this. 1407 */ 1408 if (hashsize < 512) 1409 hashsize = 512; 1410 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 1411 printf("%s: %s auto tuned to %d\n", __func__, 1412 tcbhash_tuneable, hashsize); 1413 } 1414 /* 1415 * We require a hashsize to be a power of two. 1416 * Previously if it was not a power of two we would just reset it 1417 * back to 512, which could be a nasty surprise if you did not notice 1418 * the error message. 1419 * Instead what we do is clip it to the closest power of two lower 1420 * than the specified hash value. 1421 */ 1422 if (!powerof2(hashsize)) { 1423 int oldhashsize = hashsize; 1424 1425 hashsize = maketcp_hashsize(hashsize); 1426 /* prevent absurdly low value */ 1427 if (hashsize < 16) 1428 hashsize = 16; 1429 printf("%s: WARNING: TCB hash size not a power of 2, " 1430 "clipped from %d to %d.\n", __func__, oldhashsize, 1431 hashsize); 1432 } 1433 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 1434 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 1435 1436 /* 1437 * These have to be type stable for the benefit of the timers. 1438 */ 1439 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 1440 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1441 uma_zone_set_max(V_tcpcb_zone, maxsockets); 1442 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 1443 1444 tcp_tw_init(); 1445 syncache_init(); 1446 tcp_hc_init(); 1447 1448 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1449 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1450 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1451 1452 tcp_fastopen_init(); 1453 1454 /* Skip initialization of globals for non-default instances. */ 1455 if (!IS_DEFAULT_VNET(curvnet)) 1456 return; 1457 1458 tcp_reass_global_init(); 1459 1460 /* XXX virtualize those bellow? */ 1461 tcp_delacktime = TCPTV_DELACK; 1462 tcp_keepinit = TCPTV_KEEP_INIT; 1463 tcp_keepidle = TCPTV_KEEP_IDLE; 1464 tcp_keepintvl = TCPTV_KEEPINTVL; 1465 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1466 tcp_msl = TCPTV_MSL; 1467 tcp_rexmit_initial = TCPTV_RTOBASE; 1468 if (tcp_rexmit_initial < 1) 1469 tcp_rexmit_initial = 1; 1470 tcp_rexmit_min = TCPTV_MIN; 1471 if (tcp_rexmit_min < 1) 1472 tcp_rexmit_min = 1; 1473 tcp_persmin = TCPTV_PERSMIN; 1474 tcp_persmax = TCPTV_PERSMAX; 1475 tcp_rexmit_slop = TCPTV_CPU_VAR; 1476 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1477 tcp_tcbhashsize = hashsize; 1478 1479 /* Setup the tcp function block list */ 1480 TAILQ_INIT(&t_functions); 1481 rw_init(&tcp_function_lock, "tcp_func_lock"); 1482 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1483 #ifdef TCP_BLACKBOX 1484 /* Initialize the TCP logging data. */ 1485 tcp_log_init(); 1486 #endif 1487 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1488 1489 if (tcp_soreceive_stream) { 1490 #ifdef INET 1491 tcp_usrreqs.pru_soreceive = soreceive_stream; 1492 #endif 1493 #ifdef INET6 1494 tcp6_usrreqs.pru_soreceive = soreceive_stream; 1495 #endif /* INET6 */ 1496 } 1497 1498 #ifdef INET6 1499 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 1500 #else /* INET6 */ 1501 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 1502 #endif /* INET6 */ 1503 if (max_protohdr < TCP_MINPROTOHDR) 1504 max_protohdr = TCP_MINPROTOHDR; 1505 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 1506 panic("tcp_init"); 1507 #undef TCP_MINPROTOHDR 1508 1509 ISN_LOCK_INIT(); 1510 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1511 SHUTDOWN_PRI_DEFAULT); 1512 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 1513 EVENTHANDLER_PRI_ANY); 1514 1515 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1516 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1517 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1518 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1519 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1520 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1521 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1522 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1523 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1524 #ifdef TCPPCAP 1525 tcp_pcap_init(); 1526 #endif 1527 } 1528 1529 #ifdef VIMAGE 1530 static void 1531 tcp_destroy(void *unused __unused) 1532 { 1533 int n; 1534 #ifdef TCP_HHOOK 1535 int error; 1536 #endif 1537 1538 /* 1539 * All our processes are gone, all our sockets should be cleaned 1540 * up, which means, we should be past the tcp_discardcb() calls. 1541 * Sleep to let all tcpcb timers really disappear and cleanup. 1542 */ 1543 for (;;) { 1544 INP_LIST_RLOCK(&V_tcbinfo); 1545 n = V_tcbinfo.ipi_count; 1546 INP_LIST_RUNLOCK(&V_tcbinfo); 1547 if (n == 0) 1548 break; 1549 pause("tcpdes", hz / 10); 1550 } 1551 tcp_hc_destroy(); 1552 syncache_destroy(); 1553 tcp_tw_destroy(); 1554 in_pcbinfo_destroy(&V_tcbinfo); 1555 /* tcp_discardcb() clears the sack_holes up. */ 1556 uma_zdestroy(V_sack_hole_zone); 1557 uma_zdestroy(V_tcpcb_zone); 1558 1559 /* 1560 * Cannot free the zone until all tcpcbs are released as we attach 1561 * the allocations to them. 1562 */ 1563 tcp_fastopen_destroy(); 1564 1565 #ifdef TCP_HHOOK 1566 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1567 if (error != 0) { 1568 printf("%s: WARNING: unable to deregister helper hook " 1569 "type=%d, id=%d: error %d returned\n", __func__, 1570 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1571 } 1572 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1573 if (error != 0) { 1574 printf("%s: WARNING: unable to deregister helper hook " 1575 "type=%d, id=%d: error %d returned\n", __func__, 1576 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1577 } 1578 #endif 1579 } 1580 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1581 #endif 1582 1583 void 1584 tcp_fini(void *xtp) 1585 { 1586 1587 } 1588 1589 /* 1590 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1591 * tcp_template used to store this data in mbufs, but we now recopy it out 1592 * of the tcpcb each time to conserve mbufs. 1593 */ 1594 void 1595 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1596 { 1597 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1598 1599 INP_WLOCK_ASSERT(inp); 1600 1601 #ifdef INET6 1602 if ((inp->inp_vflag & INP_IPV6) != 0) { 1603 struct ip6_hdr *ip6; 1604 1605 ip6 = (struct ip6_hdr *)ip_ptr; 1606 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1607 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1608 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1609 (IPV6_VERSION & IPV6_VERSION_MASK); 1610 if (port == 0) 1611 ip6->ip6_nxt = IPPROTO_TCP; 1612 else 1613 ip6->ip6_nxt = IPPROTO_UDP; 1614 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1615 ip6->ip6_src = inp->in6p_laddr; 1616 ip6->ip6_dst = inp->in6p_faddr; 1617 } 1618 #endif /* INET6 */ 1619 #if defined(INET6) && defined(INET) 1620 else 1621 #endif 1622 #ifdef INET 1623 { 1624 struct ip *ip; 1625 1626 ip = (struct ip *)ip_ptr; 1627 ip->ip_v = IPVERSION; 1628 ip->ip_hl = 5; 1629 ip->ip_tos = inp->inp_ip_tos; 1630 ip->ip_len = 0; 1631 ip->ip_id = 0; 1632 ip->ip_off = 0; 1633 ip->ip_ttl = inp->inp_ip_ttl; 1634 ip->ip_sum = 0; 1635 if (port == 0) 1636 ip->ip_p = IPPROTO_TCP; 1637 else 1638 ip->ip_p = IPPROTO_UDP; 1639 ip->ip_src = inp->inp_laddr; 1640 ip->ip_dst = inp->inp_faddr; 1641 } 1642 #endif /* INET */ 1643 th->th_sport = inp->inp_lport; 1644 th->th_dport = inp->inp_fport; 1645 th->th_seq = 0; 1646 th->th_ack = 0; 1647 th->th_x2 = 0; 1648 th->th_off = 5; 1649 th->th_flags = 0; 1650 th->th_win = 0; 1651 th->th_urp = 0; 1652 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1653 } 1654 1655 /* 1656 * Create template to be used to send tcp packets on a connection. 1657 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1658 * use for this function is in keepalives, which use tcp_respond. 1659 */ 1660 struct tcptemp * 1661 tcpip_maketemplate(struct inpcb *inp) 1662 { 1663 struct tcptemp *t; 1664 1665 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1666 if (t == NULL) 1667 return (NULL); 1668 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1669 return (t); 1670 } 1671 1672 /* 1673 * Send a single message to the TCP at address specified by 1674 * the given TCP/IP header. If m == NULL, then we make a copy 1675 * of the tcpiphdr at th and send directly to the addressed host. 1676 * This is used to force keep alive messages out using the TCP 1677 * template for a connection. If flags are given then we send 1678 * a message back to the TCP which originated the segment th, 1679 * and discard the mbuf containing it and any other attached mbufs. 1680 * 1681 * In any case the ack and sequence number of the transmitted 1682 * segment are as specified by the parameters. 1683 * 1684 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1685 */ 1686 void 1687 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1688 tcp_seq ack, tcp_seq seq, int flags) 1689 { 1690 struct tcpopt to; 1691 struct inpcb *inp; 1692 struct ip *ip; 1693 struct mbuf *optm; 1694 struct udphdr *uh = NULL; 1695 struct tcphdr *nth; 1696 u_char *optp; 1697 #ifdef INET6 1698 struct ip6_hdr *ip6; 1699 int isipv6; 1700 #endif /* INET6 */ 1701 int optlen, tlen, win, ulen; 1702 bool incl_opts; 1703 uint16_t port; 1704 1705 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1706 NET_EPOCH_ASSERT(); 1707 1708 #ifdef INET6 1709 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1710 ip6 = ipgen; 1711 #endif /* INET6 */ 1712 ip = ipgen; 1713 1714 if (tp != NULL) { 1715 inp = tp->t_inpcb; 1716 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 1717 INP_LOCK_ASSERT(inp); 1718 } else 1719 inp = NULL; 1720 1721 if (m != NULL) { 1722 #ifdef INET6 1723 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1724 port = m->m_pkthdr.tcp_tun_port; 1725 else 1726 #endif 1727 if (ip && (ip->ip_p == IPPROTO_UDP)) 1728 port = m->m_pkthdr.tcp_tun_port; 1729 else 1730 port = 0; 1731 } else 1732 port = tp->t_port; 1733 1734 incl_opts = false; 1735 win = 0; 1736 if (tp != NULL) { 1737 if (!(flags & TH_RST)) { 1738 win = sbspace(&inp->inp_socket->so_rcv); 1739 if (win > TCP_MAXWIN << tp->rcv_scale) 1740 win = TCP_MAXWIN << tp->rcv_scale; 1741 } 1742 if ((tp->t_flags & TF_NOOPT) == 0) 1743 incl_opts = true; 1744 } 1745 if (m == NULL) { 1746 m = m_gethdr(M_NOWAIT, MT_DATA); 1747 if (m == NULL) 1748 return; 1749 m->m_data += max_linkhdr; 1750 #ifdef INET6 1751 if (isipv6) { 1752 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1753 sizeof(struct ip6_hdr)); 1754 ip6 = mtod(m, struct ip6_hdr *); 1755 nth = (struct tcphdr *)(ip6 + 1); 1756 if (port) { 1757 /* Insert a UDP header */ 1758 uh = (struct udphdr *)nth; 1759 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1760 uh->uh_dport = port; 1761 nth = (struct tcphdr *)(uh + 1); 1762 } 1763 } else 1764 #endif /* INET6 */ 1765 { 1766 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1767 ip = mtod(m, struct ip *); 1768 nth = (struct tcphdr *)(ip + 1); 1769 if (port) { 1770 /* Insert a UDP header */ 1771 uh = (struct udphdr *)nth; 1772 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1773 uh->uh_dport = port; 1774 nth = (struct tcphdr *)(uh + 1); 1775 } 1776 } 1777 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1778 flags = TH_ACK; 1779 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1780 struct mbuf *n; 1781 1782 /* Can't reuse 'm', allocate a new mbuf. */ 1783 n = m_gethdr(M_NOWAIT, MT_DATA); 1784 if (n == NULL) { 1785 m_freem(m); 1786 return; 1787 } 1788 1789 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1790 m_freem(m); 1791 m_freem(n); 1792 return; 1793 } 1794 1795 n->m_data += max_linkhdr; 1796 /* m_len is set later */ 1797 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1798 #ifdef INET6 1799 if (isipv6) { 1800 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1801 sizeof(struct ip6_hdr)); 1802 ip6 = mtod(n, struct ip6_hdr *); 1803 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1804 nth = (struct tcphdr *)(ip6 + 1); 1805 if (port) { 1806 /* Insert a UDP header */ 1807 uh = (struct udphdr *)nth; 1808 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1809 uh->uh_dport = port; 1810 nth = (struct tcphdr *)(uh + 1); 1811 } 1812 } else 1813 #endif /* INET6 */ 1814 { 1815 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1816 ip = mtod(n, struct ip *); 1817 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1818 nth = (struct tcphdr *)(ip + 1); 1819 if (port) { 1820 /* Insert a UDP header */ 1821 uh = (struct udphdr *)nth; 1822 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1823 uh->uh_dport = port; 1824 nth = (struct tcphdr *)(uh + 1); 1825 } 1826 } 1827 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1828 xchg(nth->th_dport, nth->th_sport, uint16_t); 1829 th = nth; 1830 m_freem(m); 1831 m = n; 1832 } else { 1833 /* 1834 * reuse the mbuf. 1835 * XXX MRT We inherit the FIB, which is lucky. 1836 */ 1837 m_freem(m->m_next); 1838 m->m_next = NULL; 1839 m->m_data = (caddr_t)ipgen; 1840 /* m_len is set later */ 1841 #ifdef INET6 1842 if (isipv6) { 1843 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1844 nth = (struct tcphdr *)(ip6 + 1); 1845 } else 1846 #endif /* INET6 */ 1847 { 1848 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1849 nth = (struct tcphdr *)(ip + 1); 1850 } 1851 if (th != nth) { 1852 /* 1853 * this is usually a case when an extension header 1854 * exists between the IPv6 header and the 1855 * TCP header. 1856 */ 1857 nth->th_sport = th->th_sport; 1858 nth->th_dport = th->th_dport; 1859 } 1860 xchg(nth->th_dport, nth->th_sport, uint16_t); 1861 #undef xchg 1862 } 1863 tlen = 0; 1864 #ifdef INET6 1865 if (isipv6) 1866 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1867 #endif 1868 #if defined(INET) && defined(INET6) 1869 else 1870 #endif 1871 #ifdef INET 1872 tlen = sizeof (struct tcpiphdr); 1873 #endif 1874 if (port) 1875 tlen += sizeof (struct udphdr); 1876 #ifdef INVARIANTS 1877 m->m_len = 0; 1878 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1879 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1880 m, tlen, (long)M_TRAILINGSPACE(m))); 1881 #endif 1882 m->m_len = tlen; 1883 to.to_flags = 0; 1884 if (incl_opts) { 1885 /* Make sure we have room. */ 1886 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1887 m->m_next = m_get(M_NOWAIT, MT_DATA); 1888 if (m->m_next) { 1889 optp = mtod(m->m_next, u_char *); 1890 optm = m->m_next; 1891 } else 1892 incl_opts = false; 1893 } else { 1894 optp = (u_char *) (nth + 1); 1895 optm = m; 1896 } 1897 } 1898 if (incl_opts) { 1899 /* Timestamps. */ 1900 if (tp->t_flags & TF_RCVD_TSTMP) { 1901 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1902 to.to_tsecr = tp->ts_recent; 1903 to.to_flags |= TOF_TS; 1904 } 1905 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1906 /* TCP-MD5 (RFC2385). */ 1907 if (tp->t_flags & TF_SIGNATURE) 1908 to.to_flags |= TOF_SIGNATURE; 1909 #endif 1910 /* Add the options. */ 1911 tlen += optlen = tcp_addoptions(&to, optp); 1912 1913 /* Update m_len in the correct mbuf. */ 1914 optm->m_len += optlen; 1915 } else 1916 optlen = 0; 1917 #ifdef INET6 1918 if (isipv6) { 1919 if (uh) { 1920 ulen = tlen - sizeof(struct ip6_hdr); 1921 uh->uh_ulen = htons(ulen); 1922 } 1923 ip6->ip6_flow = 0; 1924 ip6->ip6_vfc = IPV6_VERSION; 1925 if (port) 1926 ip6->ip6_nxt = IPPROTO_UDP; 1927 else 1928 ip6->ip6_nxt = IPPROTO_TCP; 1929 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1930 } 1931 #endif 1932 #if defined(INET) && defined(INET6) 1933 else 1934 #endif 1935 #ifdef INET 1936 { 1937 if (uh) { 1938 ulen = tlen - sizeof(struct ip); 1939 uh->uh_ulen = htons(ulen); 1940 } 1941 ip->ip_len = htons(tlen); 1942 ip->ip_ttl = V_ip_defttl; 1943 if (port) { 1944 ip->ip_p = IPPROTO_UDP; 1945 } else { 1946 ip->ip_p = IPPROTO_TCP; 1947 } 1948 if (V_path_mtu_discovery) 1949 ip->ip_off |= htons(IP_DF); 1950 } 1951 #endif 1952 m->m_pkthdr.len = tlen; 1953 m->m_pkthdr.rcvif = NULL; 1954 #ifdef MAC 1955 if (inp != NULL) { 1956 /* 1957 * Packet is associated with a socket, so allow the 1958 * label of the response to reflect the socket label. 1959 */ 1960 INP_LOCK_ASSERT(inp); 1961 mac_inpcb_create_mbuf(inp, m); 1962 } else { 1963 /* 1964 * Packet is not associated with a socket, so possibly 1965 * update the label in place. 1966 */ 1967 mac_netinet_tcp_reply(m); 1968 } 1969 #endif 1970 nth->th_seq = htonl(seq); 1971 nth->th_ack = htonl(ack); 1972 nth->th_x2 = 0; 1973 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1974 nth->th_flags = flags; 1975 if (tp != NULL) 1976 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1977 else 1978 nth->th_win = htons((u_short)win); 1979 nth->th_urp = 0; 1980 1981 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1982 if (to.to_flags & TOF_SIGNATURE) { 1983 if (!TCPMD5_ENABLED() || 1984 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1985 m_freem(m); 1986 return; 1987 } 1988 } 1989 #endif 1990 1991 #ifdef INET6 1992 if (isipv6) { 1993 if (port) { 1994 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 1995 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 1996 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 1997 nth->th_sum = 0; 1998 } else { 1999 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2000 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2001 nth->th_sum = in6_cksum_pseudo(ip6, 2002 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2003 } 2004 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 2005 NULL, NULL); 2006 } 2007 #endif /* INET6 */ 2008 #if defined(INET6) && defined(INET) 2009 else 2010 #endif 2011 #ifdef INET 2012 { 2013 if (port) { 2014 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2015 htons(ulen + IPPROTO_UDP)); 2016 m->m_pkthdr.csum_flags = CSUM_UDP; 2017 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2018 nth->th_sum = 0; 2019 } else { 2020 m->m_pkthdr.csum_flags = CSUM_TCP; 2021 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2022 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2023 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2024 } 2025 } 2026 #endif /* INET */ 2027 #ifdef TCPDEBUG 2028 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 2029 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 2030 #endif 2031 TCP_PROBE3(debug__output, tp, th, m); 2032 if (flags & TH_RST) 2033 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2034 2035 #ifdef INET6 2036 if (isipv6) { 2037 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2038 (void)ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 2039 } 2040 #endif /* INET6 */ 2041 #if defined(INET) && defined(INET6) 2042 else 2043 #endif 2044 #ifdef INET 2045 { 2046 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2047 (void)ip_output(m, NULL, NULL, 0, NULL, inp); 2048 } 2049 #endif 2050 } 2051 2052 /* 2053 * Create a new TCP control block, making an 2054 * empty reassembly queue and hooking it to the argument 2055 * protocol control block. The `inp' parameter must have 2056 * come from the zone allocator set up in tcp_init(). 2057 */ 2058 struct tcpcb * 2059 tcp_newtcpcb(struct inpcb *inp) 2060 { 2061 struct tcpcb_mem *tm; 2062 struct tcpcb *tp; 2063 #ifdef INET6 2064 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2065 #endif /* INET6 */ 2066 2067 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 2068 if (tm == NULL) 2069 return (NULL); 2070 tp = &tm->tcb; 2071 2072 /* Initialise cc_var struct for this tcpcb. */ 2073 tp->ccv = &tm->ccv; 2074 tp->ccv->type = IPPROTO_TCP; 2075 tp->ccv->ccvc.tcp = tp; 2076 rw_rlock(&tcp_function_lock); 2077 tp->t_fb = tcp_func_set_ptr; 2078 refcount_acquire(&tp->t_fb->tfb_refcnt); 2079 rw_runlock(&tcp_function_lock); 2080 /* 2081 * Use the current system default CC algorithm. 2082 */ 2083 CC_LIST_RLOCK(); 2084 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 2085 CC_ALGO(tp) = CC_DEFAULT(); 2086 CC_LIST_RUNLOCK(); 2087 /* 2088 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 2089 * is called. 2090 */ 2091 in_pcbref(inp); /* Reference for tcpcb */ 2092 tp->t_inpcb = inp; 2093 2094 if (CC_ALGO(tp)->cb_init != NULL) 2095 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 2096 if (tp->t_fb->tfb_tcp_fb_fini) 2097 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2098 in_pcbrele_wlocked(inp); 2099 refcount_release(&tp->t_fb->tfb_refcnt); 2100 uma_zfree(V_tcpcb_zone, tm); 2101 return (NULL); 2102 } 2103 2104 #ifdef TCP_HHOOK 2105 tp->osd = &tm->osd; 2106 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 2107 if (tp->t_fb->tfb_tcp_fb_fini) 2108 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2109 in_pcbrele_wlocked(inp); 2110 refcount_release(&tp->t_fb->tfb_refcnt); 2111 uma_zfree(V_tcpcb_zone, tm); 2112 return (NULL); 2113 } 2114 #endif 2115 2116 #ifdef VIMAGE 2117 tp->t_vnet = inp->inp_vnet; 2118 #endif 2119 tp->t_timers = &tm->tt; 2120 TAILQ_INIT(&tp->t_segq); 2121 tp->t_maxseg = 2122 #ifdef INET6 2123 isipv6 ? V_tcp_v6mssdflt : 2124 #endif /* INET6 */ 2125 V_tcp_mssdflt; 2126 2127 /* Set up our timeouts. */ 2128 callout_init(&tp->t_timers->tt_rexmt, 1); 2129 callout_init(&tp->t_timers->tt_persist, 1); 2130 callout_init(&tp->t_timers->tt_keep, 1); 2131 callout_init(&tp->t_timers->tt_2msl, 1); 2132 callout_init(&tp->t_timers->tt_delack, 1); 2133 2134 if (V_tcp_do_rfc1323) 2135 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2136 if (V_tcp_do_sack) 2137 tp->t_flags |= TF_SACK_PERMIT; 2138 TAILQ_INIT(&tp->snd_holes); 2139 2140 /* 2141 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2142 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2143 * reasonable initial retransmit time. 2144 */ 2145 tp->t_srtt = TCPTV_SRTTBASE; 2146 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2147 tp->t_rttmin = tcp_rexmit_min; 2148 tp->t_rxtcur = tcp_rexmit_initial; 2149 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2150 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2151 tp->t_rcvtime = ticks; 2152 /* 2153 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2154 * because the socket may be bound to an IPv6 wildcard address, 2155 * which may match an IPv4-mapped IPv6 address. 2156 */ 2157 inp->inp_ip_ttl = V_ip_defttl; 2158 inp->inp_ppcb = tp; 2159 #ifdef TCPPCAP 2160 /* 2161 * Init the TCP PCAP queues. 2162 */ 2163 tcp_pcap_tcpcb_init(tp); 2164 #endif 2165 #ifdef TCP_BLACKBOX 2166 /* Initialize the per-TCPCB log data. */ 2167 tcp_log_tcpcbinit(tp); 2168 #endif 2169 tp->t_pacing_rate = -1; 2170 if (tp->t_fb->tfb_tcp_fb_init) { 2171 if ((*tp->t_fb->tfb_tcp_fb_init)(tp)) { 2172 refcount_release(&tp->t_fb->tfb_refcnt); 2173 in_pcbrele_wlocked(inp); 2174 uma_zfree(V_tcpcb_zone, tm); 2175 return (NULL); 2176 } 2177 } 2178 #ifdef STATS 2179 if (V_tcp_perconn_stats_enable == 1) 2180 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2181 #endif 2182 if (V_tcp_do_lrd) 2183 tp->t_flags |= TF_LRD; 2184 return (tp); /* XXX */ 2185 } 2186 2187 /* 2188 * Switch the congestion control algorithm back to NewReno for any active 2189 * control blocks using an algorithm which is about to go away. 2190 * This ensures the CC framework can allow the unload to proceed without leaving 2191 * any dangling pointers which would trigger a panic. 2192 * Returning non-zero would inform the CC framework that something went wrong 2193 * and it would be unsafe to allow the unload to proceed. However, there is no 2194 * way for this to occur with this implementation so we always return zero. 2195 */ 2196 int 2197 tcp_ccalgounload(struct cc_algo *unload_algo) 2198 { 2199 struct cc_algo *tmpalgo; 2200 struct inpcb *inp; 2201 struct tcpcb *tp; 2202 VNET_ITERATOR_DECL(vnet_iter); 2203 2204 /* 2205 * Check all active control blocks across all network stacks and change 2206 * any that are using "unload_algo" back to NewReno. If "unload_algo" 2207 * requires cleanup code to be run, call it. 2208 */ 2209 VNET_LIST_RLOCK(); 2210 VNET_FOREACH(vnet_iter) { 2211 CURVNET_SET(vnet_iter); 2212 INP_INFO_WLOCK(&V_tcbinfo); 2213 /* 2214 * New connections already part way through being initialised 2215 * with the CC algo we're removing will not race with this code 2216 * because the INP_INFO_WLOCK is held during initialisation. We 2217 * therefore don't enter the loop below until the connection 2218 * list has stabilised. 2219 */ 2220 CK_LIST_FOREACH(inp, &V_tcb, inp_list) { 2221 INP_WLOCK(inp); 2222 /* Important to skip tcptw structs. */ 2223 if (!(inp->inp_flags & INP_TIMEWAIT) && 2224 (tp = intotcpcb(inp)) != NULL) { 2225 /* 2226 * By holding INP_WLOCK here, we are assured 2227 * that the connection is not currently 2228 * executing inside the CC module's functions 2229 * i.e. it is safe to make the switch back to 2230 * NewReno. 2231 */ 2232 if (CC_ALGO(tp) == unload_algo) { 2233 tmpalgo = CC_ALGO(tp); 2234 if (tmpalgo->cb_destroy != NULL) 2235 tmpalgo->cb_destroy(tp->ccv); 2236 CC_DATA(tp) = NULL; 2237 /* 2238 * NewReno may allocate memory on 2239 * demand for certain stateful 2240 * configuration as needed, but is 2241 * coded to never fail on memory 2242 * allocation failure so it is a safe 2243 * fallback. 2244 */ 2245 CC_ALGO(tp) = &newreno_cc_algo; 2246 } 2247 } 2248 INP_WUNLOCK(inp); 2249 } 2250 INP_INFO_WUNLOCK(&V_tcbinfo); 2251 CURVNET_RESTORE(); 2252 } 2253 VNET_LIST_RUNLOCK(); 2254 2255 return (0); 2256 } 2257 2258 /* 2259 * Drop a TCP connection, reporting 2260 * the specified error. If connection is synchronized, 2261 * then send a RST to peer. 2262 */ 2263 struct tcpcb * 2264 tcp_drop(struct tcpcb *tp, int errno) 2265 { 2266 struct socket *so = tp->t_inpcb->inp_socket; 2267 2268 NET_EPOCH_ASSERT(); 2269 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2270 INP_WLOCK_ASSERT(tp->t_inpcb); 2271 2272 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2273 tcp_state_change(tp, TCPS_CLOSED); 2274 (void) tp->t_fb->tfb_tcp_output(tp); 2275 TCPSTAT_INC(tcps_drops); 2276 } else 2277 TCPSTAT_INC(tcps_conndrops); 2278 if (errno == ETIMEDOUT && tp->t_softerror) 2279 errno = tp->t_softerror; 2280 so->so_error = errno; 2281 return (tcp_close(tp)); 2282 } 2283 2284 void 2285 tcp_discardcb(struct tcpcb *tp) 2286 { 2287 struct inpcb *inp = tp->t_inpcb; 2288 struct socket *so = inp->inp_socket; 2289 #ifdef INET6 2290 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2291 #endif /* INET6 */ 2292 int released __unused; 2293 2294 INP_WLOCK_ASSERT(inp); 2295 2296 /* 2297 * Make sure that all of our timers are stopped before we delete the 2298 * PCB. 2299 * 2300 * If stopping a timer fails, we schedule a discard function in same 2301 * callout, and the last discard function called will take care of 2302 * deleting the tcpcb. 2303 */ 2304 tp->t_timers->tt_draincnt = 0; 2305 tcp_timer_stop(tp, TT_REXMT); 2306 tcp_timer_stop(tp, TT_PERSIST); 2307 tcp_timer_stop(tp, TT_KEEP); 2308 tcp_timer_stop(tp, TT_2MSL); 2309 tcp_timer_stop(tp, TT_DELACK); 2310 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2311 /* 2312 * Call the stop-all function of the methods, 2313 * this function should call the tcp_timer_stop() 2314 * method with each of the function specific timeouts. 2315 * That stop will be called via the tfb_tcp_timer_stop() 2316 * which should use the async drain function of the 2317 * callout system (see tcp_var.h). 2318 */ 2319 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2320 } 2321 2322 /* free the reassembly queue, if any */ 2323 tcp_reass_flush(tp); 2324 2325 #ifdef TCP_OFFLOAD 2326 /* Disconnect offload device, if any. */ 2327 if (tp->t_flags & TF_TOE) 2328 tcp_offload_detach(tp); 2329 #endif 2330 2331 tcp_free_sackholes(tp); 2332 2333 #ifdef TCPPCAP 2334 /* Free the TCP PCAP queues. */ 2335 tcp_pcap_drain(&(tp->t_inpkts)); 2336 tcp_pcap_drain(&(tp->t_outpkts)); 2337 #endif 2338 2339 /* Allow the CC algorithm to clean up after itself. */ 2340 if (CC_ALGO(tp)->cb_destroy != NULL) 2341 CC_ALGO(tp)->cb_destroy(tp->ccv); 2342 CC_DATA(tp) = NULL; 2343 2344 #ifdef TCP_HHOOK 2345 khelp_destroy_osd(tp->osd); 2346 #endif 2347 #ifdef STATS 2348 stats_blob_destroy(tp->t_stats); 2349 #endif 2350 2351 CC_ALGO(tp) = NULL; 2352 inp->inp_ppcb = NULL; 2353 if (tp->t_timers->tt_draincnt == 0) { 2354 /* We own the last reference on tcpcb, let's free it. */ 2355 #ifdef TCP_BLACKBOX 2356 tcp_log_tcpcbfini(tp); 2357 #endif 2358 TCPSTATES_DEC(tp->t_state); 2359 if (tp->t_fb->tfb_tcp_fb_fini) 2360 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2361 2362 /* 2363 * If we got enough samples through the srtt filter, 2364 * save the rtt and rttvar in the routing entry. 2365 * 'Enough' is arbitrarily defined as 4 rtt samples. 2366 * 4 samples is enough for the srtt filter to converge 2367 * to within enough % of the correct value; fewer samples 2368 * and we could save a bogus rtt. The danger is not high 2369 * as tcp quickly recovers from everything. 2370 * XXX: Works very well but needs some more statistics! 2371 * 2372 * XXXRRS: Updating must be after the stack fini() since 2373 * that may be converting some internal representation of 2374 * say srtt etc into the general one used by other stacks. 2375 * Lets also at least protect against the so being NULL 2376 * as RW stated below. 2377 */ 2378 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2379 struct hc_metrics_lite metrics; 2380 uint32_t ssthresh; 2381 2382 bzero(&metrics, sizeof(metrics)); 2383 /* 2384 * Update the ssthresh always when the conditions below 2385 * are satisfied. This gives us better new start value 2386 * for the congestion avoidance for new connections. 2387 * ssthresh is only set if packet loss occurred on a session. 2388 * 2389 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2390 * being torn down. Ideally this code would not use 'so'. 2391 */ 2392 ssthresh = tp->snd_ssthresh; 2393 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2394 /* 2395 * convert the limit from user data bytes to 2396 * packets then to packet data bytes. 2397 */ 2398 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2399 if (ssthresh < 2) 2400 ssthresh = 2; 2401 ssthresh *= (tp->t_maxseg + 2402 #ifdef INET6 2403 (isipv6 ? sizeof (struct ip6_hdr) + 2404 sizeof (struct tcphdr) : 2405 #endif 2406 sizeof (struct tcpiphdr) 2407 #ifdef INET6 2408 ) 2409 #endif 2410 ); 2411 } else 2412 ssthresh = 0; 2413 metrics.rmx_ssthresh = ssthresh; 2414 2415 metrics.rmx_rtt = tp->t_srtt; 2416 metrics.rmx_rttvar = tp->t_rttvar; 2417 metrics.rmx_cwnd = tp->snd_cwnd; 2418 metrics.rmx_sendpipe = 0; 2419 metrics.rmx_recvpipe = 0; 2420 2421 tcp_hc_update(&inp->inp_inc, &metrics); 2422 } 2423 refcount_release(&tp->t_fb->tfb_refcnt); 2424 tp->t_inpcb = NULL; 2425 uma_zfree(V_tcpcb_zone, tp); 2426 released = in_pcbrele_wlocked(inp); 2427 KASSERT(!released, ("%s: inp %p should not have been released " 2428 "here", __func__, inp)); 2429 } 2430 } 2431 2432 void 2433 tcp_timer_discard(void *ptp) 2434 { 2435 struct inpcb *inp; 2436 struct tcpcb *tp; 2437 struct epoch_tracker et; 2438 2439 tp = (struct tcpcb *)ptp; 2440 CURVNET_SET(tp->t_vnet); 2441 NET_EPOCH_ENTER(et); 2442 inp = tp->t_inpcb; 2443 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 2444 __func__, tp)); 2445 INP_WLOCK(inp); 2446 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 2447 ("%s: tcpcb has to be stopped here", __func__)); 2448 tp->t_timers->tt_draincnt--; 2449 if (tp->t_timers->tt_draincnt == 0) { 2450 /* We own the last reference on this tcpcb, let's free it. */ 2451 #ifdef TCP_BLACKBOX 2452 tcp_log_tcpcbfini(tp); 2453 #endif 2454 TCPSTATES_DEC(tp->t_state); 2455 if (tp->t_fb->tfb_tcp_fb_fini) 2456 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2457 refcount_release(&tp->t_fb->tfb_refcnt); 2458 tp->t_inpcb = NULL; 2459 uma_zfree(V_tcpcb_zone, tp); 2460 if (in_pcbrele_wlocked(inp)) { 2461 NET_EPOCH_EXIT(et); 2462 CURVNET_RESTORE(); 2463 return; 2464 } 2465 } 2466 INP_WUNLOCK(inp); 2467 NET_EPOCH_EXIT(et); 2468 CURVNET_RESTORE(); 2469 } 2470 2471 /* 2472 * Attempt to close a TCP control block, marking it as dropped, and freeing 2473 * the socket if we hold the only reference. 2474 */ 2475 struct tcpcb * 2476 tcp_close(struct tcpcb *tp) 2477 { 2478 struct inpcb *inp = tp->t_inpcb; 2479 struct socket *so; 2480 2481 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2482 INP_WLOCK_ASSERT(inp); 2483 2484 #ifdef TCP_OFFLOAD 2485 if (tp->t_state == TCPS_LISTEN) 2486 tcp_offload_listen_stop(tp); 2487 #endif 2488 /* 2489 * This releases the TFO pending counter resource for TFO listen 2490 * sockets as well as passively-created TFO sockets that transition 2491 * from SYN_RECEIVED to CLOSED. 2492 */ 2493 if (tp->t_tfo_pending) { 2494 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2495 tp->t_tfo_pending = NULL; 2496 } 2497 in_pcbdrop(inp); 2498 TCPSTAT_INC(tcps_closed); 2499 if (tp->t_state != TCPS_CLOSED) 2500 tcp_state_change(tp, TCPS_CLOSED); 2501 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2502 so = inp->inp_socket; 2503 soisdisconnected(so); 2504 if (inp->inp_flags & INP_SOCKREF) { 2505 KASSERT(so->so_state & SS_PROTOREF, 2506 ("tcp_close: !SS_PROTOREF")); 2507 inp->inp_flags &= ~INP_SOCKREF; 2508 INP_WUNLOCK(inp); 2509 SOCK_LOCK(so); 2510 so->so_state &= ~SS_PROTOREF; 2511 sofree(so); 2512 return (NULL); 2513 } 2514 return (tp); 2515 } 2516 2517 void 2518 tcp_drain(void) 2519 { 2520 VNET_ITERATOR_DECL(vnet_iter); 2521 2522 if (!do_tcpdrain) 2523 return; 2524 2525 VNET_LIST_RLOCK_NOSLEEP(); 2526 VNET_FOREACH(vnet_iter) { 2527 CURVNET_SET(vnet_iter); 2528 struct inpcb *inpb; 2529 struct tcpcb *tcpb; 2530 2531 /* 2532 * Walk the tcpbs, if existing, and flush the reassembly queue, 2533 * if there is one... 2534 * XXX: The "Net/3" implementation doesn't imply that the TCP 2535 * reassembly queue should be flushed, but in a situation 2536 * where we're really low on mbufs, this is potentially 2537 * useful. 2538 */ 2539 INP_INFO_WLOCK(&V_tcbinfo); 2540 CK_LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 2541 INP_WLOCK(inpb); 2542 if (inpb->inp_flags & INP_TIMEWAIT) { 2543 INP_WUNLOCK(inpb); 2544 continue; 2545 } 2546 if ((tcpb = intotcpcb(inpb)) != NULL) { 2547 tcp_reass_flush(tcpb); 2548 tcp_clean_sackreport(tcpb); 2549 #ifdef TCP_BLACKBOX 2550 tcp_log_drain(tcpb); 2551 #endif 2552 #ifdef TCPPCAP 2553 if (tcp_pcap_aggressive_free) { 2554 /* Free the TCP PCAP queues. */ 2555 tcp_pcap_drain(&(tcpb->t_inpkts)); 2556 tcp_pcap_drain(&(tcpb->t_outpkts)); 2557 } 2558 #endif 2559 } 2560 INP_WUNLOCK(inpb); 2561 } 2562 INP_INFO_WUNLOCK(&V_tcbinfo); 2563 CURVNET_RESTORE(); 2564 } 2565 VNET_LIST_RUNLOCK_NOSLEEP(); 2566 } 2567 2568 /* 2569 * Notify a tcp user of an asynchronous error; 2570 * store error as soft error, but wake up user 2571 * (for now, won't do anything until can select for soft error). 2572 * 2573 * Do not wake up user since there currently is no mechanism for 2574 * reporting soft errors (yet - a kqueue filter may be added). 2575 */ 2576 static struct inpcb * 2577 tcp_notify(struct inpcb *inp, int error) 2578 { 2579 struct tcpcb *tp; 2580 2581 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 2582 INP_WLOCK_ASSERT(inp); 2583 2584 if ((inp->inp_flags & INP_TIMEWAIT) || 2585 (inp->inp_flags & INP_DROPPED)) 2586 return (inp); 2587 2588 tp = intotcpcb(inp); 2589 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2590 2591 /* 2592 * Ignore some errors if we are hooked up. 2593 * If connection hasn't completed, has retransmitted several times, 2594 * and receives a second error, give up now. This is better 2595 * than waiting a long time to establish a connection that 2596 * can never complete. 2597 */ 2598 if (tp->t_state == TCPS_ESTABLISHED && 2599 (error == EHOSTUNREACH || error == ENETUNREACH || 2600 error == EHOSTDOWN)) { 2601 if (inp->inp_route.ro_nh) { 2602 NH_FREE(inp->inp_route.ro_nh); 2603 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2604 } 2605 return (inp); 2606 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2607 tp->t_softerror) { 2608 tp = tcp_drop(tp, error); 2609 if (tp != NULL) 2610 return (inp); 2611 else 2612 return (NULL); 2613 } else { 2614 tp->t_softerror = error; 2615 return (inp); 2616 } 2617 #if 0 2618 wakeup( &so->so_timeo); 2619 sorwakeup(so); 2620 sowwakeup(so); 2621 #endif 2622 } 2623 2624 static int 2625 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2626 { 2627 struct epoch_tracker et; 2628 struct inpcb *inp; 2629 struct xinpgen xig; 2630 int error; 2631 2632 if (req->newptr != NULL) 2633 return (EPERM); 2634 2635 if (req->oldptr == NULL) { 2636 int n; 2637 2638 n = V_tcbinfo.ipi_count + 2639 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2640 n += imax(n / 8, 10); 2641 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2642 return (0); 2643 } 2644 2645 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2646 return (error); 2647 2648 bzero(&xig, sizeof(xig)); 2649 xig.xig_len = sizeof xig; 2650 xig.xig_count = V_tcbinfo.ipi_count + 2651 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2652 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2653 xig.xig_sogen = so_gencnt; 2654 error = SYSCTL_OUT(req, &xig, sizeof xig); 2655 if (error) 2656 return (error); 2657 2658 error = syncache_pcblist(req); 2659 if (error) 2660 return (error); 2661 2662 NET_EPOCH_ENTER(et); 2663 for (inp = CK_LIST_FIRST(V_tcbinfo.ipi_listhead); 2664 inp != NULL; 2665 inp = CK_LIST_NEXT(inp, inp_list)) { 2666 INP_RLOCK(inp); 2667 if (inp->inp_gencnt <= xig.xig_gen) { 2668 int crerr; 2669 2670 /* 2671 * XXX: This use of cr_cansee(), introduced with 2672 * TCP state changes, is not quite right, but for 2673 * now, better than nothing. 2674 */ 2675 if (inp->inp_flags & INP_TIMEWAIT) { 2676 if (intotw(inp) != NULL) 2677 crerr = cr_cansee(req->td->td_ucred, 2678 intotw(inp)->tw_cred); 2679 else 2680 crerr = EINVAL; /* Skip this inp. */ 2681 } else 2682 crerr = cr_canseeinpcb(req->td->td_ucred, inp); 2683 if (crerr == 0) { 2684 struct xtcpcb xt; 2685 2686 tcp_inptoxtp(inp, &xt); 2687 INP_RUNLOCK(inp); 2688 error = SYSCTL_OUT(req, &xt, sizeof xt); 2689 if (error) 2690 break; 2691 else 2692 continue; 2693 } 2694 } 2695 INP_RUNLOCK(inp); 2696 } 2697 NET_EPOCH_EXIT(et); 2698 2699 if (!error) { 2700 /* 2701 * Give the user an updated idea of our state. 2702 * If the generation differs from what we told 2703 * her before, she knows that something happened 2704 * while we were processing this request, and it 2705 * might be necessary to retry. 2706 */ 2707 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2708 xig.xig_sogen = so_gencnt; 2709 xig.xig_count = V_tcbinfo.ipi_count + 2710 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2711 error = SYSCTL_OUT(req, &xig, sizeof xig); 2712 } 2713 2714 return (error); 2715 } 2716 2717 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2718 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2719 NULL, 0, tcp_pcblist, "S,xtcpcb", 2720 "List of active TCP connections"); 2721 2722 #ifdef INET 2723 static int 2724 tcp_getcred(SYSCTL_HANDLER_ARGS) 2725 { 2726 struct xucred xuc; 2727 struct sockaddr_in addrs[2]; 2728 struct epoch_tracker et; 2729 struct inpcb *inp; 2730 int error; 2731 2732 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2733 if (error) 2734 return (error); 2735 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2736 if (error) 2737 return (error); 2738 NET_EPOCH_ENTER(et); 2739 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2740 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2741 NET_EPOCH_EXIT(et); 2742 if (inp != NULL) { 2743 if (inp->inp_socket == NULL) 2744 error = ENOENT; 2745 if (error == 0) 2746 error = cr_canseeinpcb(req->td->td_ucred, inp); 2747 if (error == 0) 2748 cru2x(inp->inp_cred, &xuc); 2749 INP_RUNLOCK(inp); 2750 } else 2751 error = ENOENT; 2752 if (error == 0) 2753 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2754 return (error); 2755 } 2756 2757 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2758 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2759 0, 0, tcp_getcred, "S,xucred", 2760 "Get the xucred of a TCP connection"); 2761 #endif /* INET */ 2762 2763 #ifdef INET6 2764 static int 2765 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2766 { 2767 struct epoch_tracker et; 2768 struct xucred xuc; 2769 struct sockaddr_in6 addrs[2]; 2770 struct inpcb *inp; 2771 int error; 2772 #ifdef INET 2773 int mapped = 0; 2774 #endif 2775 2776 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2777 if (error) 2778 return (error); 2779 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2780 if (error) 2781 return (error); 2782 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2783 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2784 return (error); 2785 } 2786 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2787 #ifdef INET 2788 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2789 mapped = 1; 2790 else 2791 #endif 2792 return (EINVAL); 2793 } 2794 2795 NET_EPOCH_ENTER(et); 2796 #ifdef INET 2797 if (mapped == 1) 2798 inp = in_pcblookup(&V_tcbinfo, 2799 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2800 addrs[1].sin6_port, 2801 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2802 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2803 else 2804 #endif 2805 inp = in6_pcblookup(&V_tcbinfo, 2806 &addrs[1].sin6_addr, addrs[1].sin6_port, 2807 &addrs[0].sin6_addr, addrs[0].sin6_port, 2808 INPLOOKUP_RLOCKPCB, NULL); 2809 NET_EPOCH_EXIT(et); 2810 if (inp != NULL) { 2811 if (inp->inp_socket == NULL) 2812 error = ENOENT; 2813 if (error == 0) 2814 error = cr_canseeinpcb(req->td->td_ucred, inp); 2815 if (error == 0) 2816 cru2x(inp->inp_cred, &xuc); 2817 INP_RUNLOCK(inp); 2818 } else 2819 error = ENOENT; 2820 if (error == 0) 2821 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2822 return (error); 2823 } 2824 2825 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2826 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2827 0, 0, tcp6_getcred, "S,xucred", 2828 "Get the xucred of a TCP6 connection"); 2829 #endif /* INET6 */ 2830 2831 #ifdef INET 2832 /* Path MTU to try next when a fragmentation-needed message is received. */ 2833 static inline int 2834 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2835 { 2836 int mtu = ntohs(icp->icmp_nextmtu); 2837 2838 /* If no alternative MTU was proposed, try the next smaller one. */ 2839 if (!mtu) 2840 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2841 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2842 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2843 2844 return (mtu); 2845 } 2846 2847 static void 2848 tcp_ctlinput_with_port(int cmd, struct sockaddr *sa, void *vip, uint16_t port) 2849 { 2850 struct ip *ip = vip; 2851 struct tcphdr *th; 2852 struct in_addr faddr; 2853 struct inpcb *inp; 2854 struct tcpcb *tp; 2855 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2856 struct icmp *icp; 2857 struct in_conninfo inc; 2858 tcp_seq icmp_tcp_seq; 2859 int mtu; 2860 2861 faddr = ((struct sockaddr_in *)sa)->sin_addr; 2862 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 2863 return; 2864 2865 if (cmd == PRC_MSGSIZE) 2866 notify = tcp_mtudisc_notify; 2867 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2868 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2869 cmd == PRC_TIMXCEED_INTRANS) && ip) 2870 notify = tcp_drop_syn_sent; 2871 2872 /* 2873 * Hostdead is ugly because it goes linearly through all PCBs. 2874 * XXX: We never get this from ICMP, otherwise it makes an 2875 * excellent DoS attack on machines with many connections. 2876 */ 2877 else if (cmd == PRC_HOSTDEAD) 2878 ip = NULL; 2879 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 2880 return; 2881 2882 if (ip == NULL) { 2883 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 2884 return; 2885 } 2886 2887 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 2888 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2889 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 2890 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2891 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2892 /* signal EHOSTDOWN, as it flushes the cached route */ 2893 inp = (*notify)(inp, EHOSTDOWN); 2894 goto out; 2895 } 2896 icmp_tcp_seq = th->th_seq; 2897 if (inp != NULL) { 2898 if (!(inp->inp_flags & INP_TIMEWAIT) && 2899 !(inp->inp_flags & INP_DROPPED) && 2900 !(inp->inp_socket == NULL)) { 2901 tp = intotcpcb(inp); 2902 #ifdef TCP_OFFLOAD 2903 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 2904 /* 2905 * MTU discovery for offloaded connections. Let 2906 * the TOE driver verify seq# and process it. 2907 */ 2908 mtu = tcp_next_pmtu(icp, ip); 2909 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2910 goto out; 2911 } 2912 #endif 2913 if (tp->t_port != port) { 2914 goto out; 2915 } 2916 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2917 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2918 if (cmd == PRC_MSGSIZE) { 2919 /* 2920 * MTU discovery: we got a needfrag and 2921 * will potentially try a lower MTU. 2922 */ 2923 mtu = tcp_next_pmtu(icp, ip); 2924 2925 /* 2926 * Only process the offered MTU if it 2927 * is smaller than the current one. 2928 */ 2929 if (mtu < tp->t_maxseg + 2930 sizeof(struct tcpiphdr)) { 2931 bzero(&inc, sizeof(inc)); 2932 inc.inc_faddr = faddr; 2933 inc.inc_fibnum = 2934 inp->inp_inc.inc_fibnum; 2935 tcp_hc_updatemtu(&inc, mtu); 2936 tcp_mtudisc(inp, mtu); 2937 } 2938 } else 2939 inp = (*notify)(inp, 2940 inetctlerrmap[cmd]); 2941 } 2942 } 2943 } else { 2944 bzero(&inc, sizeof(inc)); 2945 inc.inc_fport = th->th_dport; 2946 inc.inc_lport = th->th_sport; 2947 inc.inc_faddr = faddr; 2948 inc.inc_laddr = ip->ip_src; 2949 syncache_unreach(&inc, icmp_tcp_seq, port); 2950 } 2951 out: 2952 if (inp != NULL) 2953 INP_WUNLOCK(inp); 2954 } 2955 2956 void 2957 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 2958 { 2959 tcp_ctlinput_with_port(cmd, sa, vip, htons(0)); 2960 } 2961 2962 void 2963 tcp_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *vip, void *unused) 2964 { 2965 /* Its a tunneled TCP over UDP icmp */ 2966 struct ip *outer_ip, *inner_ip; 2967 struct icmp *icmp; 2968 struct udphdr *udp; 2969 struct tcphdr *th, ttemp; 2970 int i_hlen, o_len; 2971 uint16_t port; 2972 2973 inner_ip = (struct ip *)vip; 2974 icmp = (struct icmp *)((caddr_t)inner_ip - 2975 (sizeof(struct icmp) - sizeof(struct ip))); 2976 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2977 i_hlen = inner_ip->ip_hl << 2; 2978 o_len = ntohs(outer_ip->ip_len); 2979 if (o_len < 2980 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2981 /* Not enough data present */ 2982 return; 2983 } 2984 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2985 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2986 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2987 return; 2988 } 2989 port = udp->uh_dport; 2990 th = (struct tcphdr *)(udp + 1); 2991 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2992 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2993 /* Now adjust down the size of the outer IP header */ 2994 o_len -= sizeof(struct udphdr); 2995 outer_ip->ip_len = htons(o_len); 2996 /* Now call in to the normal handling code */ 2997 tcp_ctlinput_with_port(cmd, sa, vip, port); 2998 } 2999 #endif /* INET */ 3000 3001 #ifdef INET6 3002 static inline int 3003 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 3004 { 3005 int mtu = ntohl(icmp6->icmp6_mtu); 3006 3007 /* 3008 * If no alternative MTU was proposed, or the proposed MTU was too 3009 * small, set to the min. 3010 */ 3011 if (mtu < IPV6_MMTU) 3012 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 3013 return (mtu); 3014 } 3015 3016 static void 3017 tcp6_ctlinput_with_port(int cmd, struct sockaddr *sa, void *d, uint16_t port) 3018 { 3019 struct in6_addr *dst; 3020 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 3021 struct ip6_hdr *ip6; 3022 struct mbuf *m; 3023 struct inpcb *inp; 3024 struct tcpcb *tp; 3025 struct icmp6_hdr *icmp6; 3026 struct ip6ctlparam *ip6cp = NULL; 3027 const struct sockaddr_in6 *sa6_src = NULL; 3028 struct in_conninfo inc; 3029 struct tcp_ports { 3030 uint16_t th_sport; 3031 uint16_t th_dport; 3032 } t_ports; 3033 tcp_seq icmp_tcp_seq; 3034 unsigned int mtu; 3035 unsigned int off; 3036 3037 if (sa->sa_family != AF_INET6 || 3038 sa->sa_len != sizeof(struct sockaddr_in6)) 3039 return; 3040 3041 /* if the parameter is from icmp6, decode it. */ 3042 if (d != NULL) { 3043 ip6cp = (struct ip6ctlparam *)d; 3044 icmp6 = ip6cp->ip6c_icmp6; 3045 m = ip6cp->ip6c_m; 3046 ip6 = ip6cp->ip6c_ip6; 3047 off = ip6cp->ip6c_off; 3048 sa6_src = ip6cp->ip6c_src; 3049 dst = ip6cp->ip6c_finaldst; 3050 } else { 3051 m = NULL; 3052 ip6 = NULL; 3053 off = 0; /* fool gcc */ 3054 sa6_src = &sa6_any; 3055 dst = NULL; 3056 } 3057 3058 if (cmd == PRC_MSGSIZE) 3059 notify = tcp_mtudisc_notify; 3060 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 3061 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 3062 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 3063 notify = tcp_drop_syn_sent; 3064 3065 /* 3066 * Hostdead is ugly because it goes linearly through all PCBs. 3067 * XXX: We never get this from ICMP, otherwise it makes an 3068 * excellent DoS attack on machines with many connections. 3069 */ 3070 else if (cmd == PRC_HOSTDEAD) 3071 ip6 = NULL; 3072 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 3073 return; 3074 3075 if (ip6 == NULL) { 3076 in6_pcbnotify(&V_tcbinfo, sa, 0, 3077 (const struct sockaddr *)sa6_src, 3078 0, cmd, NULL, notify); 3079 return; 3080 } 3081 3082 /* Check if we can safely get the ports from the tcp hdr */ 3083 if (m == NULL || 3084 (m->m_pkthdr.len < 3085 (int32_t) (off + sizeof(struct tcp_ports)))) { 3086 return; 3087 } 3088 bzero(&t_ports, sizeof(struct tcp_ports)); 3089 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3090 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3091 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3092 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 3093 /* signal EHOSTDOWN, as it flushes the cached route */ 3094 inp = (*notify)(inp, EHOSTDOWN); 3095 goto out; 3096 } 3097 off += sizeof(struct tcp_ports); 3098 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3099 goto out; 3100 } 3101 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3102 if (inp != NULL) { 3103 if (!(inp->inp_flags & INP_TIMEWAIT) && 3104 !(inp->inp_flags & INP_DROPPED) && 3105 !(inp->inp_socket == NULL)) { 3106 tp = intotcpcb(inp); 3107 #ifdef TCP_OFFLOAD 3108 if (tp->t_flags & TF_TOE && cmd == PRC_MSGSIZE) { 3109 /* MTU discovery for offloaded connections. */ 3110 mtu = tcp6_next_pmtu(icmp6); 3111 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3112 goto out; 3113 } 3114 #endif 3115 if (tp->t_port != port) { 3116 goto out; 3117 } 3118 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3119 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3120 if (cmd == PRC_MSGSIZE) { 3121 /* 3122 * MTU discovery: 3123 * If we got a needfrag set the MTU 3124 * in the route to the suggested new 3125 * value (if given) and then notify. 3126 */ 3127 mtu = tcp6_next_pmtu(icmp6); 3128 3129 bzero(&inc, sizeof(inc)); 3130 inc.inc_fibnum = M_GETFIB(m); 3131 inc.inc_flags |= INC_ISIPV6; 3132 inc.inc6_faddr = *dst; 3133 if (in6_setscope(&inc.inc6_faddr, 3134 m->m_pkthdr.rcvif, NULL)) 3135 goto out; 3136 /* 3137 * Only process the offered MTU if it 3138 * is smaller than the current one. 3139 */ 3140 if (mtu < tp->t_maxseg + 3141 sizeof (struct tcphdr) + 3142 sizeof (struct ip6_hdr)) { 3143 tcp_hc_updatemtu(&inc, mtu); 3144 tcp_mtudisc(inp, mtu); 3145 ICMP6STAT_INC(icp6s_pmtuchg); 3146 } 3147 } else 3148 inp = (*notify)(inp, 3149 inet6ctlerrmap[cmd]); 3150 } 3151 } 3152 } else { 3153 bzero(&inc, sizeof(inc)); 3154 inc.inc_fibnum = M_GETFIB(m); 3155 inc.inc_flags |= INC_ISIPV6; 3156 inc.inc_fport = t_ports.th_dport; 3157 inc.inc_lport = t_ports.th_sport; 3158 inc.inc6_faddr = *dst; 3159 inc.inc6_laddr = ip6->ip6_src; 3160 syncache_unreach(&inc, icmp_tcp_seq, port); 3161 } 3162 out: 3163 if (inp != NULL) 3164 INP_WUNLOCK(inp); 3165 } 3166 3167 void 3168 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 3169 { 3170 tcp6_ctlinput_with_port(cmd, sa, d, htons(0)); 3171 } 3172 3173 void 3174 tcp6_ctlinput_viaudp(int cmd, struct sockaddr *sa, void *d, void *unused) 3175 { 3176 struct ip6ctlparam *ip6cp; 3177 struct mbuf *m; 3178 struct udphdr *udp; 3179 uint16_t port; 3180 3181 ip6cp = (struct ip6ctlparam *)d; 3182 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3183 if (m == NULL) { 3184 return; 3185 } 3186 udp = mtod(m, struct udphdr *); 3187 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3188 return; 3189 } 3190 port = udp->uh_dport; 3191 m_adj(m, sizeof(struct udphdr)); 3192 if ((m->m_flags & M_PKTHDR) == 0) { 3193 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3194 } 3195 /* Now call in to the normal handling code */ 3196 tcp6_ctlinput_with_port(cmd, sa, d, port); 3197 } 3198 3199 #endif /* INET6 */ 3200 3201 static uint32_t 3202 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3203 { 3204 SIPHASH_CTX ctx; 3205 uint32_t hash[2]; 3206 3207 KASSERT(len >= SIPHASH_KEY_LENGTH, 3208 ("%s: keylen %u too short ", __func__, len)); 3209 SipHash24_Init(&ctx); 3210 SipHash_SetKey(&ctx, (uint8_t *)key); 3211 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3212 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3213 switch (inc->inc_flags & INC_ISIPV6) { 3214 #ifdef INET 3215 case 0: 3216 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3217 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3218 break; 3219 #endif 3220 #ifdef INET6 3221 case INC_ISIPV6: 3222 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3223 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3224 break; 3225 #endif 3226 } 3227 SipHash_Final((uint8_t *)hash, &ctx); 3228 3229 return (hash[0] ^ hash[1]); 3230 } 3231 3232 uint32_t 3233 tcp_new_ts_offset(struct in_conninfo *inc) 3234 { 3235 struct in_conninfo inc_store, *local_inc; 3236 3237 if (!V_tcp_ts_offset_per_conn) { 3238 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3239 inc_store.inc_lport = 0; 3240 inc_store.inc_fport = 0; 3241 local_inc = &inc_store; 3242 } else { 3243 local_inc = inc; 3244 } 3245 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3246 sizeof(V_ts_offset_secret))); 3247 } 3248 3249 /* 3250 * Following is where TCP initial sequence number generation occurs. 3251 * 3252 * There are two places where we must use initial sequence numbers: 3253 * 1. In SYN-ACK packets. 3254 * 2. In SYN packets. 3255 * 3256 * All ISNs for SYN-ACK packets are generated by the syncache. See 3257 * tcp_syncache.c for details. 3258 * 3259 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3260 * depends on this property. In addition, these ISNs should be 3261 * unguessable so as to prevent connection hijacking. To satisfy 3262 * the requirements of this situation, the algorithm outlined in 3263 * RFC 1948 is used, with only small modifications. 3264 * 3265 * Implementation details: 3266 * 3267 * Time is based off the system timer, and is corrected so that it 3268 * increases by one megabyte per second. This allows for proper 3269 * recycling on high speed LANs while still leaving over an hour 3270 * before rollover. 3271 * 3272 * As reading the *exact* system time is too expensive to be done 3273 * whenever setting up a TCP connection, we increment the time 3274 * offset in two ways. First, a small random positive increment 3275 * is added to isn_offset for each connection that is set up. 3276 * Second, the function tcp_isn_tick fires once per clock tick 3277 * and increments isn_offset as necessary so that sequence numbers 3278 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3279 * random positive increments serve only to ensure that the same 3280 * exact sequence number is never sent out twice (as could otherwise 3281 * happen when a port is recycled in less than the system tick 3282 * interval.) 3283 * 3284 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3285 * between seeding of isn_secret. This is normally set to zero, 3286 * as reseeding should not be necessary. 3287 * 3288 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3289 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3290 * general, this means holding an exclusive (write) lock. 3291 */ 3292 3293 #define ISN_BYTES_PER_SECOND 1048576 3294 #define ISN_STATIC_INCREMENT 4096 3295 #define ISN_RANDOM_INCREMENT (4096 - 1) 3296 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3297 3298 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3299 VNET_DEFINE_STATIC(int, isn_last); 3300 VNET_DEFINE_STATIC(int, isn_last_reseed); 3301 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3302 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3303 3304 #define V_isn_secret VNET(isn_secret) 3305 #define V_isn_last VNET(isn_last) 3306 #define V_isn_last_reseed VNET(isn_last_reseed) 3307 #define V_isn_offset VNET(isn_offset) 3308 #define V_isn_offset_old VNET(isn_offset_old) 3309 3310 tcp_seq 3311 tcp_new_isn(struct in_conninfo *inc) 3312 { 3313 tcp_seq new_isn; 3314 u_int32_t projected_offset; 3315 3316 ISN_LOCK(); 3317 /* Seed if this is the first use, reseed if requested. */ 3318 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3319 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3320 < (u_int)ticks))) { 3321 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3322 V_isn_last_reseed = ticks; 3323 } 3324 3325 /* Compute the hash and return the ISN. */ 3326 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3327 sizeof(V_isn_secret)); 3328 V_isn_offset += ISN_STATIC_INCREMENT + 3329 (arc4random() & ISN_RANDOM_INCREMENT); 3330 if (ticks != V_isn_last) { 3331 projected_offset = V_isn_offset_old + 3332 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3333 if (SEQ_GT(projected_offset, V_isn_offset)) 3334 V_isn_offset = projected_offset; 3335 V_isn_offset_old = V_isn_offset; 3336 V_isn_last = ticks; 3337 } 3338 new_isn += V_isn_offset; 3339 ISN_UNLOCK(); 3340 return (new_isn); 3341 } 3342 3343 /* 3344 * When a specific ICMP unreachable message is received and the 3345 * connection state is SYN-SENT, drop the connection. This behavior 3346 * is controlled by the icmp_may_rst sysctl. 3347 */ 3348 struct inpcb * 3349 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3350 { 3351 struct tcpcb *tp; 3352 3353 NET_EPOCH_ASSERT(); 3354 INP_WLOCK_ASSERT(inp); 3355 3356 if ((inp->inp_flags & INP_TIMEWAIT) || 3357 (inp->inp_flags & INP_DROPPED)) 3358 return (inp); 3359 3360 tp = intotcpcb(inp); 3361 if (tp->t_state != TCPS_SYN_SENT) 3362 return (inp); 3363 3364 if (IS_FASTOPEN(tp->t_flags)) 3365 tcp_fastopen_disable_path(tp); 3366 3367 tp = tcp_drop(tp, errno); 3368 if (tp != NULL) 3369 return (inp); 3370 else 3371 return (NULL); 3372 } 3373 3374 /* 3375 * When `need fragmentation' ICMP is received, update our idea of the MSS 3376 * based on the new value. Also nudge TCP to send something, since we 3377 * know the packet we just sent was dropped. 3378 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3379 */ 3380 static struct inpcb * 3381 tcp_mtudisc_notify(struct inpcb *inp, int error) 3382 { 3383 3384 tcp_mtudisc(inp, -1); 3385 return (inp); 3386 } 3387 3388 static void 3389 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3390 { 3391 struct tcpcb *tp; 3392 struct socket *so; 3393 3394 INP_WLOCK_ASSERT(inp); 3395 if ((inp->inp_flags & INP_TIMEWAIT) || 3396 (inp->inp_flags & INP_DROPPED)) 3397 return; 3398 3399 tp = intotcpcb(inp); 3400 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3401 3402 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3403 3404 so = inp->inp_socket; 3405 SOCKBUF_LOCK(&so->so_snd); 3406 /* If the mss is larger than the socket buffer, decrease the mss. */ 3407 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3408 tp->t_maxseg = so->so_snd.sb_hiwat; 3409 SOCKBUF_UNLOCK(&so->so_snd); 3410 3411 TCPSTAT_INC(tcps_mturesent); 3412 tp->t_rtttime = 0; 3413 tp->snd_nxt = tp->snd_una; 3414 tcp_free_sackholes(tp); 3415 tp->snd_recover = tp->snd_max; 3416 if (tp->t_flags & TF_SACK_PERMIT) 3417 EXIT_FASTRECOVERY(tp->t_flags); 3418 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3419 /* 3420 * Conceptually the snd_nxt setting 3421 * and freeing sack holes should 3422 * be done by the default stacks 3423 * own tfb_tcp_mtu_chg(). 3424 */ 3425 tp->t_fb->tfb_tcp_mtu_chg(tp); 3426 } 3427 tp->t_fb->tfb_tcp_output(tp); 3428 } 3429 3430 #ifdef INET 3431 /* 3432 * Look-up the routing entry to the peer of this inpcb. If no route 3433 * is found and it cannot be allocated, then return 0. This routine 3434 * is called by TCP routines that access the rmx structure and by 3435 * tcp_mss_update to get the peer/interface MTU. 3436 */ 3437 uint32_t 3438 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3439 { 3440 struct nhop_object *nh; 3441 struct ifnet *ifp; 3442 uint32_t maxmtu = 0; 3443 3444 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3445 3446 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3447 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3448 if (nh == NULL) 3449 return (0); 3450 3451 ifp = nh->nh_ifp; 3452 maxmtu = nh->nh_mtu; 3453 3454 /* Report additional interface capabilities. */ 3455 if (cap != NULL) { 3456 if (ifp->if_capenable & IFCAP_TSO4 && 3457 ifp->if_hwassist & CSUM_TSO) { 3458 cap->ifcap |= CSUM_TSO; 3459 cap->tsomax = ifp->if_hw_tsomax; 3460 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3461 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3462 } 3463 } 3464 } 3465 return (maxmtu); 3466 } 3467 #endif /* INET */ 3468 3469 #ifdef INET6 3470 uint32_t 3471 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3472 { 3473 struct nhop_object *nh; 3474 struct in6_addr dst6; 3475 uint32_t scopeid; 3476 struct ifnet *ifp; 3477 uint32_t maxmtu = 0; 3478 3479 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3480 3481 if (inc->inc_flags & INC_IPV6MINMTU) 3482 return (IPV6_MMTU); 3483 3484 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3485 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3486 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3487 if (nh == NULL) 3488 return (0); 3489 3490 ifp = nh->nh_ifp; 3491 maxmtu = nh->nh_mtu; 3492 3493 /* Report additional interface capabilities. */ 3494 if (cap != NULL) { 3495 if (ifp->if_capenable & IFCAP_TSO6 && 3496 ifp->if_hwassist & CSUM_TSO) { 3497 cap->ifcap |= CSUM_TSO; 3498 cap->tsomax = ifp->if_hw_tsomax; 3499 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3500 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3501 } 3502 } 3503 } 3504 3505 return (maxmtu); 3506 } 3507 #endif /* INET6 */ 3508 3509 /* 3510 * Calculate effective SMSS per RFC5681 definition for a given TCP 3511 * connection at its current state, taking into account SACK and etc. 3512 */ 3513 u_int 3514 tcp_maxseg(const struct tcpcb *tp) 3515 { 3516 u_int optlen; 3517 3518 if (tp->t_flags & TF_NOOPT) 3519 return (tp->t_maxseg); 3520 3521 /* 3522 * Here we have a simplified code from tcp_addoptions(), 3523 * without a proper loop, and having most of paddings hardcoded. 3524 * We might make mistakes with padding here in some edge cases, 3525 * but this is harmless, since result of tcp_maxseg() is used 3526 * only in cwnd and ssthresh estimations. 3527 */ 3528 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3529 if (tp->t_flags & TF_RCVD_TSTMP) 3530 optlen = TCPOLEN_TSTAMP_APPA; 3531 else 3532 optlen = 0; 3533 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3534 if (tp->t_flags & TF_SIGNATURE) 3535 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3536 #endif 3537 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3538 optlen += TCPOLEN_SACKHDR; 3539 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3540 optlen = PADTCPOLEN(optlen); 3541 } 3542 } else { 3543 if (tp->t_flags & TF_REQ_TSTMP) 3544 optlen = TCPOLEN_TSTAMP_APPA; 3545 else 3546 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3547 if (tp->t_flags & TF_REQ_SCALE) 3548 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3549 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3550 if (tp->t_flags & TF_SIGNATURE) 3551 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3552 #endif 3553 if (tp->t_flags & TF_SACK_PERMIT) 3554 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3555 } 3556 #undef PAD 3557 optlen = min(optlen, TCP_MAXOLEN); 3558 return (tp->t_maxseg - optlen); 3559 } 3560 3561 3562 u_int 3563 tcp_fixed_maxseg(const struct tcpcb *tp) 3564 { 3565 int optlen; 3566 3567 if (tp->t_flags & TF_NOOPT) 3568 return (tp->t_maxseg); 3569 3570 /* 3571 * Here we have a simplified code from tcp_addoptions(), 3572 * without a proper loop, and having most of paddings hardcoded. 3573 * We only consider fixed options that we would send every 3574 * time I.e. SACK is not considered. This is important 3575 * for cc modules to figure out what the modulo of the 3576 * cwnd should be. 3577 */ 3578 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3579 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3580 if (tp->t_flags & TF_RCVD_TSTMP) 3581 optlen = TCPOLEN_TSTAMP_APPA; 3582 else 3583 optlen = 0; 3584 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3585 if (tp->t_flags & TF_SIGNATURE) 3586 optlen += PAD(TCPOLEN_SIGNATURE); 3587 #endif 3588 } else { 3589 if (tp->t_flags & TF_REQ_TSTMP) 3590 optlen = TCPOLEN_TSTAMP_APPA; 3591 else 3592 optlen = PAD(TCPOLEN_MAXSEG); 3593 if (tp->t_flags & TF_REQ_SCALE) 3594 optlen += PAD(TCPOLEN_WINDOW); 3595 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3596 if (tp->t_flags & TF_SIGNATURE) 3597 optlen += PAD(TCPOLEN_SIGNATURE); 3598 #endif 3599 if (tp->t_flags & TF_SACK_PERMIT) 3600 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3601 } 3602 #undef PAD 3603 optlen = min(optlen, TCP_MAXOLEN); 3604 return (tp->t_maxseg - optlen); 3605 } 3606 3607 3608 3609 static int 3610 sysctl_drop(SYSCTL_HANDLER_ARGS) 3611 { 3612 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3613 struct sockaddr_storage addrs[2]; 3614 struct inpcb *inp; 3615 struct tcpcb *tp; 3616 struct tcptw *tw; 3617 struct sockaddr_in *fin, *lin; 3618 struct epoch_tracker et; 3619 #ifdef INET6 3620 struct sockaddr_in6 *fin6, *lin6; 3621 #endif 3622 int error; 3623 3624 inp = NULL; 3625 fin = lin = NULL; 3626 #ifdef INET6 3627 fin6 = lin6 = NULL; 3628 #endif 3629 error = 0; 3630 3631 if (req->oldptr != NULL || req->oldlen != 0) 3632 return (EINVAL); 3633 if (req->newptr == NULL) 3634 return (EPERM); 3635 if (req->newlen < sizeof(addrs)) 3636 return (ENOMEM); 3637 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3638 if (error) 3639 return (error); 3640 3641 switch (addrs[0].ss_family) { 3642 #ifdef INET6 3643 case AF_INET6: 3644 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3645 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3646 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3647 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3648 return (EINVAL); 3649 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3650 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3651 return (EINVAL); 3652 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3653 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3654 fin = (struct sockaddr_in *)&addrs[0]; 3655 lin = (struct sockaddr_in *)&addrs[1]; 3656 break; 3657 } 3658 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3659 if (error) 3660 return (error); 3661 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3662 if (error) 3663 return (error); 3664 break; 3665 #endif 3666 #ifdef INET 3667 case AF_INET: 3668 fin = (struct sockaddr_in *)&addrs[0]; 3669 lin = (struct sockaddr_in *)&addrs[1]; 3670 if (fin->sin_len != sizeof(struct sockaddr_in) || 3671 lin->sin_len != sizeof(struct sockaddr_in)) 3672 return (EINVAL); 3673 break; 3674 #endif 3675 default: 3676 return (EINVAL); 3677 } 3678 NET_EPOCH_ENTER(et); 3679 switch (addrs[0].ss_family) { 3680 #ifdef INET6 3681 case AF_INET6: 3682 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3683 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3684 INPLOOKUP_WLOCKPCB, NULL); 3685 break; 3686 #endif 3687 #ifdef INET 3688 case AF_INET: 3689 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3690 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3691 break; 3692 #endif 3693 } 3694 if (inp != NULL) { 3695 if (inp->inp_flags & INP_TIMEWAIT) { 3696 /* 3697 * XXXRW: There currently exists a state where an 3698 * inpcb is present, but its timewait state has been 3699 * discarded. For now, don't allow dropping of this 3700 * type of inpcb. 3701 */ 3702 tw = intotw(inp); 3703 if (tw != NULL) 3704 tcp_twclose(tw, 0); 3705 else 3706 INP_WUNLOCK(inp); 3707 } else if ((inp->inp_flags & INP_DROPPED) == 0 && 3708 !SOLISTENING(inp->inp_socket)) { 3709 tp = intotcpcb(inp); 3710 tp = tcp_drop(tp, ECONNABORTED); 3711 if (tp != NULL) 3712 INP_WUNLOCK(inp); 3713 } else 3714 INP_WUNLOCK(inp); 3715 } else 3716 error = ESRCH; 3717 NET_EPOCH_EXIT(et); 3718 return (error); 3719 } 3720 3721 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3722 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3723 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3724 "Drop TCP connection"); 3725 3726 #ifdef KERN_TLS 3727 static int 3728 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3729 { 3730 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3731 struct sockaddr_storage addrs[2]; 3732 struct inpcb *inp; 3733 struct sockaddr_in *fin, *lin; 3734 struct epoch_tracker et; 3735 #ifdef INET6 3736 struct sockaddr_in6 *fin6, *lin6; 3737 #endif 3738 int error; 3739 3740 inp = NULL; 3741 fin = lin = NULL; 3742 #ifdef INET6 3743 fin6 = lin6 = NULL; 3744 #endif 3745 error = 0; 3746 3747 if (req->oldptr != NULL || req->oldlen != 0) 3748 return (EINVAL); 3749 if (req->newptr == NULL) 3750 return (EPERM); 3751 if (req->newlen < sizeof(addrs)) 3752 return (ENOMEM); 3753 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3754 if (error) 3755 return (error); 3756 3757 switch (addrs[0].ss_family) { 3758 #ifdef INET6 3759 case AF_INET6: 3760 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3761 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3762 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3763 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3764 return (EINVAL); 3765 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3766 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3767 return (EINVAL); 3768 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3769 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3770 fin = (struct sockaddr_in *)&addrs[0]; 3771 lin = (struct sockaddr_in *)&addrs[1]; 3772 break; 3773 } 3774 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3775 if (error) 3776 return (error); 3777 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3778 if (error) 3779 return (error); 3780 break; 3781 #endif 3782 #ifdef INET 3783 case AF_INET: 3784 fin = (struct sockaddr_in *)&addrs[0]; 3785 lin = (struct sockaddr_in *)&addrs[1]; 3786 if (fin->sin_len != sizeof(struct sockaddr_in) || 3787 lin->sin_len != sizeof(struct sockaddr_in)) 3788 return (EINVAL); 3789 break; 3790 #endif 3791 default: 3792 return (EINVAL); 3793 } 3794 NET_EPOCH_ENTER(et); 3795 switch (addrs[0].ss_family) { 3796 #ifdef INET6 3797 case AF_INET6: 3798 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3799 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3800 INPLOOKUP_WLOCKPCB, NULL); 3801 break; 3802 #endif 3803 #ifdef INET 3804 case AF_INET: 3805 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3806 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3807 break; 3808 #endif 3809 } 3810 NET_EPOCH_EXIT(et); 3811 if (inp != NULL) { 3812 if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) != 0 || 3813 inp->inp_socket == NULL) { 3814 error = ECONNRESET; 3815 INP_WUNLOCK(inp); 3816 } else { 3817 struct socket *so; 3818 3819 so = inp->inp_socket; 3820 soref(so); 3821 error = ktls_set_tx_mode(so, 3822 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3823 INP_WUNLOCK(inp); 3824 SOCK_LOCK(so); 3825 sorele(so); 3826 } 3827 } else 3828 error = ESRCH; 3829 return (error); 3830 } 3831 3832 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3833 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3834 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3835 "Switch TCP connection to SW TLS"); 3836 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3837 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3838 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3839 "Switch TCP connection to ifnet TLS"); 3840 #endif 3841 3842 /* 3843 * Generate a standardized TCP log line for use throughout the 3844 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3845 * allow use in the interrupt context. 3846 * 3847 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3848 * NB: The function may return NULL if memory allocation failed. 3849 * 3850 * Due to header inclusion and ordering limitations the struct ip 3851 * and ip6_hdr pointers have to be passed as void pointers. 3852 */ 3853 char * 3854 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3855 const void *ip6hdr) 3856 { 3857 3858 /* Is logging enabled? */ 3859 if (V_tcp_log_in_vain == 0) 3860 return (NULL); 3861 3862 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3863 } 3864 3865 char * 3866 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3867 const void *ip6hdr) 3868 { 3869 3870 /* Is logging enabled? */ 3871 if (tcp_log_debug == 0) 3872 return (NULL); 3873 3874 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3875 } 3876 3877 static char * 3878 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 3879 const void *ip6hdr) 3880 { 3881 char *s, *sp; 3882 size_t size; 3883 struct ip *ip; 3884 #ifdef INET6 3885 const struct ip6_hdr *ip6; 3886 3887 ip6 = (const struct ip6_hdr *)ip6hdr; 3888 #endif /* INET6 */ 3889 ip = (struct ip *)ip4hdr; 3890 3891 /* 3892 * The log line looks like this: 3893 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3894 */ 3895 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3896 sizeof(PRINT_TH_FLAGS) + 1 + 3897 #ifdef INET6 3898 2 * INET6_ADDRSTRLEN; 3899 #else 3900 2 * INET_ADDRSTRLEN; 3901 #endif /* INET6 */ 3902 3903 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3904 if (s == NULL) 3905 return (NULL); 3906 3907 strcat(s, "TCP: ["); 3908 sp = s + strlen(s); 3909 3910 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3911 inet_ntoa_r(inc->inc_faddr, sp); 3912 sp = s + strlen(s); 3913 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3914 sp = s + strlen(s); 3915 inet_ntoa_r(inc->inc_laddr, sp); 3916 sp = s + strlen(s); 3917 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3918 #ifdef INET6 3919 } else if (inc) { 3920 ip6_sprintf(sp, &inc->inc6_faddr); 3921 sp = s + strlen(s); 3922 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3923 sp = s + strlen(s); 3924 ip6_sprintf(sp, &inc->inc6_laddr); 3925 sp = s + strlen(s); 3926 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3927 } else if (ip6 && th) { 3928 ip6_sprintf(sp, &ip6->ip6_src); 3929 sp = s + strlen(s); 3930 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3931 sp = s + strlen(s); 3932 ip6_sprintf(sp, &ip6->ip6_dst); 3933 sp = s + strlen(s); 3934 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3935 #endif /* INET6 */ 3936 #ifdef INET 3937 } else if (ip && th) { 3938 inet_ntoa_r(ip->ip_src, sp); 3939 sp = s + strlen(s); 3940 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3941 sp = s + strlen(s); 3942 inet_ntoa_r(ip->ip_dst, sp); 3943 sp = s + strlen(s); 3944 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3945 #endif /* INET */ 3946 } else { 3947 free(s, M_TCPLOG); 3948 return (NULL); 3949 } 3950 sp = s + strlen(s); 3951 if (th) 3952 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 3953 if (*(s + size - 1) != '\0') 3954 panic("%s: string too long", __func__); 3955 return (s); 3956 } 3957 3958 /* 3959 * A subroutine which makes it easy to track TCP state changes with DTrace. 3960 * This function shouldn't be called for t_state initializations that don't 3961 * correspond to actual TCP state transitions. 3962 */ 3963 void 3964 tcp_state_change(struct tcpcb *tp, int newstate) 3965 { 3966 #if defined(KDTRACE_HOOKS) 3967 int pstate = tp->t_state; 3968 #endif 3969 3970 TCPSTATES_DEC(tp->t_state); 3971 TCPSTATES_INC(newstate); 3972 tp->t_state = newstate; 3973 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3974 } 3975 3976 /* 3977 * Create an external-format (``xtcpcb'') structure using the information in 3978 * the kernel-format tcpcb structure pointed to by tp. This is done to 3979 * reduce the spew of irrelevant information over this interface, to isolate 3980 * user code from changes in the kernel structure, and potentially to provide 3981 * information-hiding if we decide that some of this information should be 3982 * hidden from users. 3983 */ 3984 void 3985 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3986 { 3987 struct tcpcb *tp = intotcpcb(inp); 3988 struct tcptw *tw = intotw(inp); 3989 sbintime_t now; 3990 3991 bzero(xt, sizeof(*xt)); 3992 if (inp->inp_flags & INP_TIMEWAIT) { 3993 xt->t_state = TCPS_TIME_WAIT; 3994 xt->xt_encaps_port = tw->t_port; 3995 } else { 3996 xt->t_state = tp->t_state; 3997 xt->t_logstate = tp->t_logstate; 3998 xt->t_flags = tp->t_flags; 3999 xt->t_sndzerowin = tp->t_sndzerowin; 4000 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 4001 xt->t_rcvoopack = tp->t_rcvoopack; 4002 xt->t_rcv_wnd = tp->rcv_wnd; 4003 xt->t_snd_wnd = tp->snd_wnd; 4004 xt->t_snd_cwnd = tp->snd_cwnd; 4005 xt->t_snd_ssthresh = tp->snd_ssthresh; 4006 xt->t_maxseg = tp->t_maxseg; 4007 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 4008 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 4009 4010 now = getsbinuptime(); 4011 #define COPYTIMER(ttt) do { \ 4012 if (callout_active(&tp->t_timers->ttt)) \ 4013 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 4014 SBT_1MS; \ 4015 else \ 4016 xt->ttt = 0; \ 4017 } while (0) 4018 COPYTIMER(tt_delack); 4019 COPYTIMER(tt_rexmt); 4020 COPYTIMER(tt_persist); 4021 COPYTIMER(tt_keep); 4022 COPYTIMER(tt_2msl); 4023 #undef COPYTIMER 4024 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 4025 4026 xt->xt_encaps_port = tp->t_port; 4027 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 4028 TCP_FUNCTION_NAME_LEN_MAX); 4029 bcopy(CC_ALGO(tp)->name, xt->xt_cc, 4030 TCP_CA_NAME_MAX); 4031 #ifdef TCP_BLACKBOX 4032 (void)tcp_log_get_id(tp, xt->xt_logid); 4033 #endif 4034 } 4035 4036 xt->xt_len = sizeof(struct xtcpcb); 4037 in_pcbtoxinpcb(inp, &xt->xt_inp); 4038 if (inp->inp_socket == NULL) 4039 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 4040 } 4041 4042 void 4043 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 4044 { 4045 uint32_t bit, i; 4046 4047 if ((tp == NULL) || 4048 (status > TCP_EI_STATUS_MAX_VALUE) || 4049 (status == 0)) { 4050 /* Invalid */ 4051 return; 4052 } 4053 if (status > (sizeof(uint32_t) * 8)) { 4054 /* Should this be a KASSERT? */ 4055 return; 4056 } 4057 bit = 1U << (status - 1); 4058 if (bit & tp->t_end_info_status) { 4059 /* already logged */ 4060 return; 4061 } 4062 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4063 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4064 tp->t_end_info_bytes[i] = status; 4065 tp->t_end_info_status |= bit; 4066 break; 4067 } 4068 } 4069 } 4070 4071 int 4072 tcp_can_enable_pacing(void) 4073 { 4074 4075 if ((tcp_pacing_limit == -1) || 4076 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4077 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4078 shadow_num_connections = number_of_tcp_connections_pacing; 4079 return (1); 4080 } else { 4081 return (0); 4082 } 4083 } 4084 4085 static uint8_t tcp_pacing_warning = 0; 4086 4087 void 4088 tcp_decrement_paced_conn(void) 4089 { 4090 uint32_t ret; 4091 4092 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4093 shadow_num_connections = number_of_tcp_connections_pacing; 4094 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4095 if (ret == 0) { 4096 if (tcp_pacing_limit != -1) { 4097 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4098 tcp_pacing_limit = 0; 4099 } else if (tcp_pacing_warning == 0) { 4100 printf("Warning pacing count is invalid, invalid decrement\n"); 4101 tcp_pacing_warning = 1; 4102 } 4103 } 4104 } 4105