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 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/arb.h> 45 #include <sys/callout.h> 46 #include <sys/eventhandler.h> 47 #ifdef TCP_HHOOK 48 #include <sys/hhook.h> 49 #endif 50 #include <sys/kernel.h> 51 #ifdef TCP_HHOOK 52 #include <sys/khelp.h> 53 #endif 54 #ifdef KERN_TLS 55 #include <sys/ktls.h> 56 #endif 57 #include <sys/qmath.h> 58 #include <sys/stats.h> 59 #include <sys/sysctl.h> 60 #include <sys/jail.h> 61 #include <sys/malloc.h> 62 #include <sys/refcount.h> 63 #include <sys/mbuf.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/sdt.h> 67 #include <sys/socket.h> 68 #include <sys/socketvar.h> 69 #include <sys/protosw.h> 70 #include <sys/random.h> 71 72 #include <vm/uma.h> 73 74 #include <net/route.h> 75 #include <net/route/nhop.h> 76 #include <net/if.h> 77 #include <net/if_var.h> 78 #include <net/if_private.h> 79 #include <net/vnet.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_fib.h> 83 #include <netinet/in_kdtrace.h> 84 #include <netinet/in_pcb.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/in_var.h> 87 #include <netinet/ip.h> 88 #include <netinet/ip_icmp.h> 89 #include <netinet/ip_var.h> 90 #ifdef INET6 91 #include <netinet/icmp6.h> 92 #include <netinet/ip6.h> 93 #include <netinet6/in6_fib.h> 94 #include <netinet6/in6_pcb.h> 95 #include <netinet6/ip6_var.h> 96 #include <netinet6/scope6_var.h> 97 #include <netinet6/nd6.h> 98 #endif 99 100 #include <netinet/tcp.h> 101 #ifdef INVARIANTS 102 #define TCPSTATES 103 #endif 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_ecn.h> 109 #include <netinet/tcp_log_buf.h> 110 #include <netinet/tcp_syncache.h> 111 #include <netinet/tcp_hpts.h> 112 #include <netinet/tcp_lro.h> 113 #include <netinet/cc/cc.h> 114 #include <netinet/tcpip.h> 115 #include <netinet/tcp_fastopen.h> 116 #include <netinet/tcp_accounting.h> 117 #ifdef TCPPCAP 118 #include <netinet/tcp_pcap.h> 119 #endif 120 #ifdef TCP_OFFLOAD 121 #include <netinet/tcp_offload.h> 122 #endif 123 #include <netinet/udp.h> 124 #include <netinet/udp_var.h> 125 #ifdef INET6 126 #include <netinet6/tcp6_var.h> 127 #endif 128 129 #include <netipsec/ipsec_support.h> 130 131 #include <machine/in_cksum.h> 132 #include <crypto/siphash/siphash.h> 133 134 #include <security/mac/mac_framework.h> 135 136 #ifdef INET6 137 static ip6proto_ctlinput_t tcp6_ctlinput; 138 static udp_tun_icmp_t tcp6_ctlinput_viaudp; 139 #endif 140 141 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 142 #ifdef INET6 143 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 144 #endif 145 146 #ifdef TCP_SAD_DETECTION 147 /* Sack attack detection thresholds and such */ 148 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 149 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 150 "Sack Attack detection thresholds"); 151 int32_t tcp_force_detection = 0; 152 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 153 CTLFLAG_RW, 154 &tcp_force_detection, 0, 155 "Do we force detection even if the INP has it off?"); 156 int32_t tcp_sad_limit = 10000; 157 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, limit, 158 CTLFLAG_RW, 159 &tcp_sad_limit, 10000, 160 "If SaD is enabled, what is the limit to sendmap entries (0 = unlimited)?"); 161 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 162 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 163 CTLFLAG_RW, 164 &tcp_sack_to_ack_thresh, 700, 165 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 166 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 167 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 168 CTLFLAG_RW, 169 &tcp_sack_to_move_thresh, 600, 170 "Percentage of sack moves we must see above (10.1 percent is 101)"); 171 int32_t tcp_restoral_thresh = 450; /* 45 % (sack:2:ack -25%) (mv:ratio -15%) **/ 172 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 173 CTLFLAG_RW, 174 &tcp_restoral_thresh, 450, 175 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 176 int32_t tcp_sad_decay_val = 800; 177 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 178 CTLFLAG_RW, 179 &tcp_sad_decay_val, 800, 180 "The decay percentage (10.1 percent equals 101 )"); 181 int32_t tcp_map_minimum = 500; 182 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 183 CTLFLAG_RW, 184 &tcp_map_minimum, 500, 185 "Number of Map enteries before we start detection"); 186 int32_t tcp_sad_pacing_interval = 2000; 187 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 188 CTLFLAG_RW, 189 &tcp_sad_pacing_interval, 2000, 190 "What is the minimum pacing interval for a classified attacker?"); 191 192 int32_t tcp_sad_low_pps = 100; 193 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 194 CTLFLAG_RW, 195 &tcp_sad_low_pps, 100, 196 "What is the input pps that below which we do not decay?"); 197 #endif 198 uint32_t tcp_ack_war_time_window = 1000; 199 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 200 CTLFLAG_RW, 201 &tcp_ack_war_time_window, 1000, 202 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 203 uint32_t tcp_ack_war_cnt = 5; 204 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 205 CTLFLAG_RW, 206 &tcp_ack_war_cnt, 5, 207 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 208 209 struct rwlock tcp_function_lock; 210 211 static int 212 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 213 { 214 int error, new; 215 216 new = V_tcp_mssdflt; 217 error = sysctl_handle_int(oidp, &new, 0, req); 218 if (error == 0 && req->newptr) { 219 if (new < TCP_MINMSS) 220 error = EINVAL; 221 else 222 V_tcp_mssdflt = new; 223 } 224 return (error); 225 } 226 227 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 228 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 229 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 230 "Default TCP Maximum Segment Size"); 231 232 #ifdef INET6 233 static int 234 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 235 { 236 int error, new; 237 238 new = V_tcp_v6mssdflt; 239 error = sysctl_handle_int(oidp, &new, 0, req); 240 if (error == 0 && req->newptr) { 241 if (new < TCP_MINMSS) 242 error = EINVAL; 243 else 244 V_tcp_v6mssdflt = new; 245 } 246 return (error); 247 } 248 249 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 250 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 251 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 252 "Default TCP Maximum Segment Size for IPv6"); 253 #endif /* INET6 */ 254 255 /* 256 * Minimum MSS we accept and use. This prevents DoS attacks where 257 * we are forced to a ridiculous low MSS like 20 and send hundreds 258 * of packets instead of one. The effect scales with the available 259 * bandwidth and quickly saturates the CPU and network interface 260 * with packet generation and sending. Set to zero to disable MINMSS 261 * checking. This setting prevents us from sending too small packets. 262 */ 263 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 264 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 265 &VNET_NAME(tcp_minmss), 0, 266 "Minimum TCP Maximum Segment Size"); 267 268 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 269 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 270 &VNET_NAME(tcp_do_rfc1323), 0, 271 "Enable rfc1323 (high performance TCP) extensions"); 272 273 /* 274 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 275 * Some stacks negotiate TS, but never send them after connection setup. Some 276 * stacks negotiate TS, but don't send them when sending keep-alive segments. 277 * These include modern widely deployed TCP stacks. 278 * Therefore tolerating violations for now... 279 */ 280 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 281 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 282 &VNET_NAME(tcp_tolerate_missing_ts), 0, 283 "Tolerate missing TCP timestamps"); 284 285 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 286 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 287 &VNET_NAME(tcp_ts_offset_per_conn), 0, 288 "Initialize TCP timestamps per connection instead of per host pair"); 289 290 /* How many connections are pacing */ 291 static volatile uint32_t number_of_tcp_connections_pacing = 0; 292 static uint32_t shadow_num_connections = 0; 293 static counter_u64_t tcp_pacing_failures; 294 295 static int tcp_pacing_limit = 10000; 296 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 297 &tcp_pacing_limit, 1000, 298 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 299 300 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 301 &shadow_num_connections, 0, "Number of TCP connections being paced"); 302 303 SYSCTL_COUNTER_U64(_net_inet_tcp, OID_AUTO, pacing_failures, CTLFLAG_RD, 304 &tcp_pacing_failures, "Number of times we failed to enable pacing to avoid exceeding the limit"); 305 306 static int tcp_log_debug = 0; 307 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 308 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 309 310 static int tcp_tcbhashsize; 311 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 312 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 313 314 static int do_tcpdrain = 1; 315 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 316 "Enable tcp_drain routine for extra help when low on mbufs"); 317 318 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 319 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 320 321 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 322 #define V_icmp_may_rst VNET(icmp_may_rst) 323 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 324 &VNET_NAME(icmp_may_rst), 0, 325 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 326 327 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 328 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 329 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 330 &VNET_NAME(tcp_isn_reseed_interval), 0, 331 "Seconds between reseeding of ISN secret"); 332 333 static int tcp_soreceive_stream; 334 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 335 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 336 337 VNET_DEFINE(uma_zone_t, sack_hole_zone); 338 #define V_sack_hole_zone VNET(sack_hole_zone) 339 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 340 static int 341 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 342 { 343 int error; 344 uint32_t new; 345 346 new = V_tcp_map_entries_limit; 347 error = sysctl_handle_int(oidp, &new, 0, req); 348 if (error == 0 && req->newptr) { 349 /* only allow "0" and value > minimum */ 350 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 351 error = EINVAL; 352 else 353 V_tcp_map_entries_limit = new; 354 } 355 return (error); 356 } 357 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 358 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 359 &VNET_NAME(tcp_map_entries_limit), 0, 360 &sysctl_net_inet_tcp_map_limit_check, "IU", 361 "Total sendmap entries limit"); 362 363 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 364 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 365 &VNET_NAME(tcp_map_split_limit), 0, 366 "Total sendmap split entries limit"); 367 368 #ifdef TCP_HHOOK 369 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 370 #endif 371 372 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 373 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 374 #define V_ts_offset_secret VNET(ts_offset_secret) 375 376 static int tcp_default_fb_init(struct tcpcb *tp, void **ptr); 377 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 378 static int tcp_default_handoff_ok(struct tcpcb *tp); 379 static struct inpcb *tcp_notify(struct inpcb *, int); 380 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 381 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 382 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int); 383 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 384 const void *ip4hdr, const void *ip6hdr); 385 static void tcp_default_switch_failed(struct tcpcb *tp); 386 static ipproto_ctlinput_t tcp_ctlinput; 387 static udp_tun_icmp_t tcp_ctlinput_viaudp; 388 389 static struct tcp_function_block tcp_def_funcblk = { 390 .tfb_tcp_block_name = "freebsd", 391 .tfb_tcp_output = tcp_default_output, 392 .tfb_tcp_do_segment = tcp_do_segment, 393 .tfb_tcp_ctloutput = tcp_default_ctloutput, 394 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 395 .tfb_tcp_fb_init = tcp_default_fb_init, 396 .tfb_tcp_fb_fini = tcp_default_fb_fini, 397 .tfb_switch_failed = tcp_default_switch_failed, 398 }; 399 400 static int tcp_fb_cnt = 0; 401 struct tcp_funchead t_functions; 402 VNET_DEFINE_STATIC(struct tcp_function_block *, tcp_func_set_ptr) = &tcp_def_funcblk; 403 #define V_tcp_func_set_ptr VNET(tcp_func_set_ptr) 404 405 void 406 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 407 { 408 TCPSTAT_INC(tcps_dsack_count); 409 tp->t_dsack_pack++; 410 if (tlp == 0) { 411 if (SEQ_GT(end, start)) { 412 tp->t_dsack_bytes += (end - start); 413 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 414 } else { 415 tp->t_dsack_tlp_bytes += (start - end); 416 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 417 } 418 } else { 419 if (SEQ_GT(end, start)) { 420 tp->t_dsack_bytes += (end - start); 421 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 422 } else { 423 tp->t_dsack_tlp_bytes += (start - end); 424 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 425 } 426 } 427 } 428 429 static struct tcp_function_block * 430 find_tcp_functions_locked(struct tcp_function_set *fs) 431 { 432 struct tcp_function *f; 433 struct tcp_function_block *blk=NULL; 434 435 TAILQ_FOREACH(f, &t_functions, tf_next) { 436 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 437 blk = f->tf_fb; 438 break; 439 } 440 } 441 return(blk); 442 } 443 444 static struct tcp_function_block * 445 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 446 { 447 struct tcp_function_block *rblk=NULL; 448 struct tcp_function *f; 449 450 TAILQ_FOREACH(f, &t_functions, tf_next) { 451 if (f->tf_fb == blk) { 452 rblk = blk; 453 if (s) { 454 *s = f; 455 } 456 break; 457 } 458 } 459 return (rblk); 460 } 461 462 struct tcp_function_block * 463 find_and_ref_tcp_functions(struct tcp_function_set *fs) 464 { 465 struct tcp_function_block *blk; 466 467 rw_rlock(&tcp_function_lock); 468 blk = find_tcp_functions_locked(fs); 469 if (blk) 470 refcount_acquire(&blk->tfb_refcnt); 471 rw_runlock(&tcp_function_lock); 472 return(blk); 473 } 474 475 struct tcp_function_block * 476 find_and_ref_tcp_fb(struct tcp_function_block *blk) 477 { 478 struct tcp_function_block *rblk; 479 480 rw_rlock(&tcp_function_lock); 481 rblk = find_tcp_fb_locked(blk, NULL); 482 if (rblk) 483 refcount_acquire(&rblk->tfb_refcnt); 484 rw_runlock(&tcp_function_lock); 485 return(rblk); 486 } 487 488 /* Find a matching alias for the given tcp_function_block. */ 489 int 490 find_tcp_function_alias(struct tcp_function_block *blk, 491 struct tcp_function_set *fs) 492 { 493 struct tcp_function *f; 494 int found; 495 496 found = 0; 497 rw_rlock(&tcp_function_lock); 498 TAILQ_FOREACH(f, &t_functions, tf_next) { 499 if ((f->tf_fb == blk) && 500 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 501 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 502 /* Matching function block with different name. */ 503 strncpy(fs->function_set_name, f->tf_name, 504 TCP_FUNCTION_NAME_LEN_MAX); 505 found = 1; 506 break; 507 } 508 } 509 /* Null terminate the string appropriately. */ 510 if (found) { 511 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 512 } else { 513 fs->function_set_name[0] = '\0'; 514 } 515 rw_runlock(&tcp_function_lock); 516 return (found); 517 } 518 519 static struct tcp_function_block * 520 find_and_ref_tcp_default_fb(void) 521 { 522 struct tcp_function_block *rblk; 523 524 rw_rlock(&tcp_function_lock); 525 rblk = V_tcp_func_set_ptr; 526 refcount_acquire(&rblk->tfb_refcnt); 527 rw_runlock(&tcp_function_lock); 528 return (rblk); 529 } 530 531 void 532 tcp_switch_back_to_default(struct tcpcb *tp) 533 { 534 struct tcp_function_block *tfb; 535 void *ptr = NULL; 536 537 KASSERT(tp->t_fb != &tcp_def_funcblk, 538 ("%s: called by the built-in default stack", __func__)); 539 540 /* 541 * Now, we'll find a new function block to use. 542 * Start by trying the current user-selected 543 * default, unless this stack is the user-selected 544 * default. 545 */ 546 tfb = find_and_ref_tcp_default_fb(); 547 if (tfb == tp->t_fb) { 548 refcount_release(&tfb->tfb_refcnt); 549 tfb = NULL; 550 } 551 /* Does the stack accept this connection? */ 552 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 553 (*tfb->tfb_tcp_handoff_ok)(tp)) { 554 refcount_release(&tfb->tfb_refcnt); 555 tfb = NULL; 556 } 557 /* Try to use that stack. */ 558 if (tfb != NULL) { 559 /* Initialize the new stack. If it succeeds, we are done. */ 560 if (tfb->tfb_tcp_fb_init == NULL || 561 (*tfb->tfb_tcp_fb_init)(tp, &ptr) == 0) { 562 /* Release the old stack */ 563 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 564 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 565 refcount_release(&tp->t_fb->tfb_refcnt); 566 /* Now set in all the pointers */ 567 tp->t_fb = tfb; 568 tp->t_fb_ptr = ptr; 569 return; 570 } 571 /* 572 * Initialization failed. Release the reference count on 573 * the looked up default stack. 574 */ 575 refcount_release(&tfb->tfb_refcnt); 576 } 577 578 /* 579 * If that wasn't feasible, use the built-in default 580 * stack which is not allowed to reject anyone. 581 */ 582 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 583 if (tfb == NULL) { 584 /* there always should be a default */ 585 panic("Can't refer to tcp_def_funcblk"); 586 } 587 if (tfb->tfb_tcp_handoff_ok != NULL) { 588 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 589 /* The default stack cannot say no */ 590 panic("Default stack rejects a new session?"); 591 } 592 } 593 if (tfb->tfb_tcp_fb_init != NULL && 594 (*tfb->tfb_tcp_fb_init)(tp, &ptr)) { 595 /* The default stack cannot fail */ 596 panic("Default stack initialization failed"); 597 } 598 /* Now release the old stack */ 599 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 600 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 601 refcount_release(&tp->t_fb->tfb_refcnt); 602 /* And set in the pointers to the new */ 603 tp->t_fb = tfb; 604 tp->t_fb_ptr = ptr; 605 } 606 607 static bool 608 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 609 const struct sockaddr *sa, void *ctx) 610 { 611 struct ip *iph; 612 #ifdef INET6 613 struct ip6_hdr *ip6; 614 #endif 615 struct udphdr *uh; 616 struct tcphdr *th; 617 int thlen; 618 uint16_t port; 619 620 TCPSTAT_INC(tcps_tunneled_pkts); 621 if ((m->m_flags & M_PKTHDR) == 0) { 622 /* Can't handle one that is not a pkt hdr */ 623 TCPSTAT_INC(tcps_tunneled_errs); 624 goto out; 625 } 626 thlen = sizeof(struct tcphdr); 627 if (m->m_len < off + sizeof(struct udphdr) + thlen && 628 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 629 TCPSTAT_INC(tcps_tunneled_errs); 630 goto out; 631 } 632 iph = mtod(m, struct ip *); 633 uh = (struct udphdr *)((caddr_t)iph + off); 634 th = (struct tcphdr *)(uh + 1); 635 thlen = th->th_off << 2; 636 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 637 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 638 if (m == NULL) { 639 TCPSTAT_INC(tcps_tunneled_errs); 640 goto out; 641 } else { 642 iph = mtod(m, struct ip *); 643 uh = (struct udphdr *)((caddr_t)iph + off); 644 th = (struct tcphdr *)(uh + 1); 645 } 646 } 647 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 648 bcopy(th, uh, m->m_len - off); 649 m->m_len -= sizeof(struct udphdr); 650 m->m_pkthdr.len -= sizeof(struct udphdr); 651 /* 652 * We use the same algorithm for 653 * both UDP and TCP for c-sum. So 654 * the code in tcp_input will skip 655 * the checksum. So we do nothing 656 * with the flag (m->m_pkthdr.csum_flags). 657 */ 658 switch (iph->ip_v) { 659 #ifdef INET 660 case IPVERSION: 661 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 662 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 663 break; 664 #endif 665 #ifdef INET6 666 case IPV6_VERSION >> 4: 667 ip6 = mtod(m, struct ip6_hdr *); 668 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 669 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 670 break; 671 #endif 672 default: 673 goto out; 674 break; 675 } 676 return (true); 677 out: 678 m_freem(m); 679 680 return (true); 681 } 682 683 static int 684 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 685 { 686 int error=ENOENT; 687 struct tcp_function_set fs; 688 struct tcp_function_block *blk; 689 690 memset(&fs, 0, sizeof(fs)); 691 rw_rlock(&tcp_function_lock); 692 blk = find_tcp_fb_locked(V_tcp_func_set_ptr, NULL); 693 if (blk) { 694 /* Found him */ 695 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 696 fs.pcbcnt = blk->tfb_refcnt; 697 } 698 rw_runlock(&tcp_function_lock); 699 error = sysctl_handle_string(oidp, fs.function_set_name, 700 sizeof(fs.function_set_name), req); 701 702 /* Check for error or no change */ 703 if (error != 0 || req->newptr == NULL) 704 return(error); 705 706 rw_wlock(&tcp_function_lock); 707 blk = find_tcp_functions_locked(&fs); 708 if ((blk == NULL) || 709 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 710 error = ENOENT; 711 goto done; 712 } 713 V_tcp_func_set_ptr = blk; 714 done: 715 rw_wunlock(&tcp_function_lock); 716 return (error); 717 } 718 719 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 720 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 721 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 722 "Set/get the default TCP functions"); 723 724 static int 725 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 726 { 727 int error, cnt, linesz; 728 struct tcp_function *f; 729 char *buffer, *cp; 730 size_t bufsz, outsz; 731 bool alias; 732 733 cnt = 0; 734 rw_rlock(&tcp_function_lock); 735 TAILQ_FOREACH(f, &t_functions, tf_next) { 736 cnt++; 737 } 738 rw_runlock(&tcp_function_lock); 739 740 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 741 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 742 743 error = 0; 744 cp = buffer; 745 746 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 747 "Alias", "PCB count"); 748 cp += linesz; 749 bufsz -= linesz; 750 outsz = linesz; 751 752 rw_rlock(&tcp_function_lock); 753 TAILQ_FOREACH(f, &t_functions, tf_next) { 754 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 755 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 756 f->tf_fb->tfb_tcp_block_name, 757 (f->tf_fb == V_tcp_func_set_ptr) ? '*' : ' ', 758 alias ? f->tf_name : "-", 759 f->tf_fb->tfb_refcnt); 760 if (linesz >= bufsz) { 761 error = EOVERFLOW; 762 break; 763 } 764 cp += linesz; 765 bufsz -= linesz; 766 outsz += linesz; 767 } 768 rw_runlock(&tcp_function_lock); 769 if (error == 0) 770 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 771 free(buffer, M_TEMP); 772 return (error); 773 } 774 775 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 776 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 777 NULL, 0, sysctl_net_inet_list_available, "A", 778 "list available TCP Function sets"); 779 780 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 781 782 #ifdef INET 783 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 784 #define V_udp4_tun_socket VNET(udp4_tun_socket) 785 #endif 786 #ifdef INET6 787 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 788 #define V_udp6_tun_socket VNET(udp6_tun_socket) 789 #endif 790 791 static struct sx tcpoudp_lock; 792 793 static void 794 tcp_over_udp_stop(void) 795 { 796 797 sx_assert(&tcpoudp_lock, SA_XLOCKED); 798 799 #ifdef INET 800 if (V_udp4_tun_socket != NULL) { 801 soclose(V_udp4_tun_socket); 802 V_udp4_tun_socket = NULL; 803 } 804 #endif 805 #ifdef INET6 806 if (V_udp6_tun_socket != NULL) { 807 soclose(V_udp6_tun_socket); 808 V_udp6_tun_socket = NULL; 809 } 810 #endif 811 } 812 813 static int 814 tcp_over_udp_start(void) 815 { 816 uint16_t port; 817 int ret; 818 #ifdef INET 819 struct sockaddr_in sin; 820 #endif 821 #ifdef INET6 822 struct sockaddr_in6 sin6; 823 #endif 824 825 sx_assert(&tcpoudp_lock, SA_XLOCKED); 826 827 port = V_tcp_udp_tunneling_port; 828 if (ntohs(port) == 0) { 829 /* Must have a port set */ 830 return (EINVAL); 831 } 832 #ifdef INET 833 if (V_udp4_tun_socket != NULL) { 834 /* Already running -- must stop first */ 835 return (EALREADY); 836 } 837 #endif 838 #ifdef INET6 839 if (V_udp6_tun_socket != NULL) { 840 /* Already running -- must stop first */ 841 return (EALREADY); 842 } 843 #endif 844 #ifdef INET 845 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 846 SOCK_DGRAM, IPPROTO_UDP, 847 curthread->td_ucred, curthread))) { 848 tcp_over_udp_stop(); 849 return (ret); 850 } 851 /* Call the special UDP hook. */ 852 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 853 tcp_recv_udp_tunneled_packet, 854 tcp_ctlinput_viaudp, 855 NULL))) { 856 tcp_over_udp_stop(); 857 return (ret); 858 } 859 /* Ok, we have a socket, bind it to the port. */ 860 memset(&sin, 0, sizeof(struct sockaddr_in)); 861 sin.sin_len = sizeof(struct sockaddr_in); 862 sin.sin_family = AF_INET; 863 sin.sin_port = htons(port); 864 if ((ret = sobind(V_udp4_tun_socket, 865 (struct sockaddr *)&sin, curthread))) { 866 tcp_over_udp_stop(); 867 return (ret); 868 } 869 #endif 870 #ifdef INET6 871 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 872 SOCK_DGRAM, IPPROTO_UDP, 873 curthread->td_ucred, curthread))) { 874 tcp_over_udp_stop(); 875 return (ret); 876 } 877 /* Call the special UDP hook. */ 878 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 879 tcp_recv_udp_tunneled_packet, 880 tcp6_ctlinput_viaudp, 881 NULL))) { 882 tcp_over_udp_stop(); 883 return (ret); 884 } 885 /* Ok, we have a socket, bind it to the port. */ 886 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 887 sin6.sin6_len = sizeof(struct sockaddr_in6); 888 sin6.sin6_family = AF_INET6; 889 sin6.sin6_port = htons(port); 890 if ((ret = sobind(V_udp6_tun_socket, 891 (struct sockaddr *)&sin6, curthread))) { 892 tcp_over_udp_stop(); 893 return (ret); 894 } 895 #endif 896 return (0); 897 } 898 899 static int 900 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 901 { 902 int error; 903 uint32_t old, new; 904 905 old = V_tcp_udp_tunneling_port; 906 new = old; 907 error = sysctl_handle_int(oidp, &new, 0, req); 908 if ((error == 0) && 909 (req->newptr != NULL)) { 910 if ((new < TCP_TUNNELING_PORT_MIN) || 911 (new > TCP_TUNNELING_PORT_MAX)) { 912 error = EINVAL; 913 } else { 914 sx_xlock(&tcpoudp_lock); 915 V_tcp_udp_tunneling_port = new; 916 if (old != 0) { 917 tcp_over_udp_stop(); 918 } 919 if (new != 0) { 920 error = tcp_over_udp_start(); 921 if (error != 0) { 922 V_tcp_udp_tunneling_port = 0; 923 } 924 } 925 sx_xunlock(&tcpoudp_lock); 926 } 927 } 928 return (error); 929 } 930 931 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 932 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 933 &VNET_NAME(tcp_udp_tunneling_port), 934 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 935 "Tunneling port for tcp over udp"); 936 937 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 938 939 static int 940 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 941 { 942 int error, new; 943 944 new = V_tcp_udp_tunneling_overhead; 945 error = sysctl_handle_int(oidp, &new, 0, req); 946 if (error == 0 && req->newptr) { 947 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 948 (new > TCP_TUNNELING_OVERHEAD_MAX)) 949 error = EINVAL; 950 else 951 V_tcp_udp_tunneling_overhead = new; 952 } 953 return (error); 954 } 955 956 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 957 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 958 &VNET_NAME(tcp_udp_tunneling_overhead), 959 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 960 "MSS reduction when using tcp over udp"); 961 962 /* 963 * Exports one (struct tcp_function_info) for each alias/name. 964 */ 965 static int 966 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 967 { 968 int cnt, error; 969 struct tcp_function *f; 970 struct tcp_function_info tfi; 971 972 /* 973 * We don't allow writes. 974 */ 975 if (req->newptr != NULL) 976 return (EINVAL); 977 978 /* 979 * Wire the old buffer so we can directly copy the functions to 980 * user space without dropping the lock. 981 */ 982 if (req->oldptr != NULL) { 983 error = sysctl_wire_old_buffer(req, 0); 984 if (error) 985 return (error); 986 } 987 988 /* 989 * Walk the list and copy out matching entries. If INVARIANTS 990 * is compiled in, also walk the list to verify the length of 991 * the list matches what we have recorded. 992 */ 993 rw_rlock(&tcp_function_lock); 994 995 cnt = 0; 996 #ifndef INVARIANTS 997 if (req->oldptr == NULL) { 998 cnt = tcp_fb_cnt; 999 goto skip_loop; 1000 } 1001 #endif 1002 TAILQ_FOREACH(f, &t_functions, tf_next) { 1003 #ifdef INVARIANTS 1004 cnt++; 1005 #endif 1006 if (req->oldptr != NULL) { 1007 bzero(&tfi, sizeof(tfi)); 1008 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 1009 tfi.tfi_id = f->tf_fb->tfb_id; 1010 (void)strlcpy(tfi.tfi_alias, f->tf_name, 1011 sizeof(tfi.tfi_alias)); 1012 (void)strlcpy(tfi.tfi_name, 1013 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 1014 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 1015 /* 1016 * Don't stop on error, as that is the 1017 * mechanism we use to accumulate length 1018 * information if the buffer was too short. 1019 */ 1020 } 1021 } 1022 KASSERT(cnt == tcp_fb_cnt, 1023 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1024 #ifndef INVARIANTS 1025 skip_loop: 1026 #endif 1027 rw_runlock(&tcp_function_lock); 1028 if (req->oldptr == NULL) 1029 error = SYSCTL_OUT(req, NULL, 1030 (cnt + 1) * sizeof(struct tcp_function_info)); 1031 1032 return (error); 1033 } 1034 1035 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1036 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1037 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1038 "List TCP function block name-to-ID mappings"); 1039 1040 /* 1041 * tfb_tcp_handoff_ok() function for the default stack. 1042 * Note that we'll basically try to take all comers. 1043 */ 1044 static int 1045 tcp_default_handoff_ok(struct tcpcb *tp) 1046 { 1047 1048 return (0); 1049 } 1050 1051 /* 1052 * tfb_tcp_fb_init() function for the default stack. 1053 * 1054 * This handles making sure we have appropriate timers set if you are 1055 * transitioning a socket that has some amount of setup done. 1056 * 1057 * The init() fuction from the default can *never* return non-zero i.e. 1058 * it is required to always succeed since it is the stack of last resort! 1059 */ 1060 static int 1061 tcp_default_fb_init(struct tcpcb *tp, void **ptr) 1062 { 1063 struct socket *so = tptosocket(tp); 1064 int rexmt; 1065 1066 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1067 /* We don't use the pointer */ 1068 *ptr = NULL; 1069 1070 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1071 ("%s: connection %p in unexpected state %d", __func__, tp, 1072 tp->t_state)); 1073 1074 /* Make sure we get no interesting mbuf queuing behavior */ 1075 /* All mbuf queue/ack compress flags should be off */ 1076 tcp_lro_features_off(tp); 1077 1078 /* Cancel the GP measurement in progress */ 1079 tp->t_flags &= ~TF_GPUTINPROG; 1080 /* Validate the timers are not in usec, if they are convert */ 1081 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS); 1082 if ((tp->t_state == TCPS_SYN_SENT) || 1083 (tp->t_state == TCPS_SYN_RECEIVED)) 1084 rexmt = tcp_rexmit_initial * tcp_backoff[tp->t_rxtshift]; 1085 else 1086 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; 1087 if (tp->t_rxtshift == 0) 1088 tp->t_rxtcur = rexmt; 1089 else 1090 TCPT_RANGESET(tp->t_rxtcur, rexmt, tp->t_rttmin, TCPTV_REXMTMAX); 1091 1092 /* 1093 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1094 * know what to do for unexpected states (which includes TIME_WAIT). 1095 */ 1096 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1097 return (0); 1098 1099 /* 1100 * Make sure some kind of transmission timer is set if there is 1101 * outstanding data. 1102 */ 1103 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1104 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1105 tcp_timer_active(tp, TT_PERSIST))) { 1106 /* 1107 * If the session has established and it looks like it should 1108 * be in the persist state, set the persist timer. Otherwise, 1109 * set the retransmit timer. 1110 */ 1111 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1112 (int32_t)(tp->snd_nxt - tp->snd_una) < 1113 (int32_t)sbavail(&so->so_snd)) 1114 tcp_setpersist(tp); 1115 else 1116 tcp_timer_activate(tp, TT_REXMT, TP_RXTCUR(tp)); 1117 } 1118 1119 /* All non-embryonic sessions get a keepalive timer. */ 1120 if (!tcp_timer_active(tp, TT_KEEP)) 1121 tcp_timer_activate(tp, TT_KEEP, 1122 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1123 TP_KEEPINIT(tp)); 1124 1125 /* 1126 * Make sure critical variables are initialized 1127 * if transitioning while in Recovery. 1128 */ 1129 if IN_FASTRECOVERY(tp->t_flags) { 1130 if (tp->sackhint.recover_fs == 0) 1131 tp->sackhint.recover_fs = max(1, 1132 tp->snd_nxt - tp->snd_una); 1133 } 1134 1135 return (0); 1136 } 1137 1138 /* 1139 * tfb_tcp_fb_fini() function for the default stack. 1140 * 1141 * This changes state as necessary (or prudent) to prepare for another stack 1142 * to assume responsibility for the connection. 1143 */ 1144 static void 1145 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1146 { 1147 1148 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1149 1150 #ifdef TCP_BLACKBOX 1151 tcp_log_flowend(tp); 1152 #endif 1153 tp->t_acktime = 0; 1154 return; 1155 } 1156 1157 /* 1158 * Target size of TCP PCB hash tables. Must be a power of two. 1159 * 1160 * Note that this can be overridden by the kernel environment 1161 * variable net.inet.tcp.tcbhashsize 1162 */ 1163 #ifndef TCBHASHSIZE 1164 #define TCBHASHSIZE 0 1165 #endif 1166 1167 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1168 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1169 1170 static struct mtx isn_mtx; 1171 1172 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1173 #define ISN_LOCK() mtx_lock(&isn_mtx) 1174 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1175 1176 INPCBSTORAGE_DEFINE(tcpcbstor, tcpcb, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1177 1178 /* 1179 * Take a value and get the next power of 2 that doesn't overflow. 1180 * Used to size the tcp_inpcb hash buckets. 1181 */ 1182 static int 1183 maketcp_hashsize(int size) 1184 { 1185 int hashsize; 1186 1187 /* 1188 * auto tune. 1189 * get the next power of 2 higher than maxsockets. 1190 */ 1191 hashsize = 1 << fls(size); 1192 /* catch overflow, and just go one power of 2 smaller */ 1193 if (hashsize < size) { 1194 hashsize = 1 << (fls(size) - 1); 1195 } 1196 return (hashsize); 1197 } 1198 1199 static volatile int next_tcp_stack_id = 1; 1200 1201 /* 1202 * Register a TCP function block with the name provided in the names 1203 * array. (Note that this function does NOT automatically register 1204 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1205 * explicitly include blk->tfb_tcp_block_name in the list of names if 1206 * you wish to register the stack with that name.) 1207 * 1208 * Either all name registrations will succeed or all will fail. If 1209 * a name registration fails, the function will update the num_names 1210 * argument to point to the array index of the name that encountered 1211 * the failure. 1212 * 1213 * Returns 0 on success, or an error code on failure. 1214 */ 1215 int 1216 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1217 const char *names[], int *num_names) 1218 { 1219 struct tcp_function *n; 1220 struct tcp_function_set fs; 1221 int error, i; 1222 1223 KASSERT(names != NULL && *num_names > 0, 1224 ("%s: Called with 0-length name list", __func__)); 1225 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1226 KASSERT(rw_initialized(&tcp_function_lock), 1227 ("%s: called too early", __func__)); 1228 1229 if ((blk->tfb_tcp_output == NULL) || 1230 (blk->tfb_tcp_do_segment == NULL) || 1231 (blk->tfb_tcp_ctloutput == NULL) || 1232 (strlen(blk->tfb_tcp_block_name) == 0)) { 1233 /* 1234 * These functions are required and you 1235 * need a name. 1236 */ 1237 *num_names = 0; 1238 return (EINVAL); 1239 } 1240 1241 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1242 *num_names = 0; 1243 return (EINVAL); 1244 } 1245 1246 refcount_init(&blk->tfb_refcnt, 0); 1247 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1248 for (i = 0; i < *num_names; i++) { 1249 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1250 if (n == NULL) { 1251 error = ENOMEM; 1252 goto cleanup; 1253 } 1254 n->tf_fb = blk; 1255 1256 (void)strlcpy(fs.function_set_name, names[i], 1257 sizeof(fs.function_set_name)); 1258 rw_wlock(&tcp_function_lock); 1259 if (find_tcp_functions_locked(&fs) != NULL) { 1260 /* Duplicate name space not allowed */ 1261 rw_wunlock(&tcp_function_lock); 1262 free(n, M_TCPFUNCTIONS); 1263 error = EALREADY; 1264 goto cleanup; 1265 } 1266 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1267 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1268 tcp_fb_cnt++; 1269 rw_wunlock(&tcp_function_lock); 1270 } 1271 return(0); 1272 1273 cleanup: 1274 /* 1275 * Deregister the names we just added. Because registration failed 1276 * for names[i], we don't need to deregister that name. 1277 */ 1278 *num_names = i; 1279 rw_wlock(&tcp_function_lock); 1280 while (--i >= 0) { 1281 TAILQ_FOREACH(n, &t_functions, tf_next) { 1282 if (!strncmp(n->tf_name, names[i], 1283 TCP_FUNCTION_NAME_LEN_MAX)) { 1284 TAILQ_REMOVE(&t_functions, n, tf_next); 1285 tcp_fb_cnt--; 1286 n->tf_fb = NULL; 1287 free(n, M_TCPFUNCTIONS); 1288 break; 1289 } 1290 } 1291 } 1292 rw_wunlock(&tcp_function_lock); 1293 return (error); 1294 } 1295 1296 /* 1297 * Register a TCP function block using the name provided in the name 1298 * argument. 1299 * 1300 * Returns 0 on success, or an error code on failure. 1301 */ 1302 int 1303 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1304 int wait) 1305 { 1306 const char *name_list[1]; 1307 int num_names, rv; 1308 1309 num_names = 1; 1310 if (name != NULL) 1311 name_list[0] = name; 1312 else 1313 name_list[0] = blk->tfb_tcp_block_name; 1314 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1315 return (rv); 1316 } 1317 1318 /* 1319 * Register a TCP function block using the name defined in 1320 * blk->tfb_tcp_block_name. 1321 * 1322 * Returns 0 on success, or an error code on failure. 1323 */ 1324 int 1325 register_tcp_functions(struct tcp_function_block *blk, int wait) 1326 { 1327 1328 return (register_tcp_functions_as_name(blk, NULL, wait)); 1329 } 1330 1331 /* 1332 * Deregister all names associated with a function block. This 1333 * functionally removes the function block from use within the system. 1334 * 1335 * When called with a true quiesce argument, mark the function block 1336 * as being removed so no more stacks will use it and determine 1337 * whether the removal would succeed. 1338 * 1339 * When called with a false quiesce argument, actually attempt the 1340 * removal. 1341 * 1342 * When called with a force argument, attempt to switch all TCBs to 1343 * use the default stack instead of returning EBUSY. 1344 * 1345 * Returns 0 on success (or if the removal would succeed), or an error 1346 * code on failure. 1347 */ 1348 int 1349 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1350 bool force) 1351 { 1352 struct tcp_function *f; 1353 VNET_ITERATOR_DECL(vnet_iter); 1354 1355 if (blk == &tcp_def_funcblk) { 1356 /* You can't un-register the default */ 1357 return (EPERM); 1358 } 1359 rw_wlock(&tcp_function_lock); 1360 VNET_LIST_RLOCK_NOSLEEP(); 1361 VNET_FOREACH(vnet_iter) { 1362 CURVNET_SET(vnet_iter); 1363 if (blk == V_tcp_func_set_ptr) { 1364 /* You can't free the current default in some vnet. */ 1365 CURVNET_RESTORE(); 1366 VNET_LIST_RUNLOCK_NOSLEEP(); 1367 rw_wunlock(&tcp_function_lock); 1368 return (EBUSY); 1369 } 1370 CURVNET_RESTORE(); 1371 } 1372 VNET_LIST_RUNLOCK_NOSLEEP(); 1373 /* Mark the block so no more stacks can use it. */ 1374 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1375 /* 1376 * If TCBs are still attached to the stack, attempt to switch them 1377 * to the default stack. 1378 */ 1379 if (force && blk->tfb_refcnt) { 1380 struct inpcb *inp; 1381 struct tcpcb *tp; 1382 VNET_ITERATOR_DECL(vnet_iter); 1383 1384 rw_wunlock(&tcp_function_lock); 1385 1386 VNET_LIST_RLOCK(); 1387 VNET_FOREACH(vnet_iter) { 1388 CURVNET_SET(vnet_iter); 1389 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1390 INPLOOKUP_WLOCKPCB); 1391 1392 while ((inp = inp_next(&inpi)) != NULL) { 1393 tp = intotcpcb(inp); 1394 if (tp == NULL || tp->t_fb != blk) 1395 continue; 1396 tcp_switch_back_to_default(tp); 1397 } 1398 CURVNET_RESTORE(); 1399 } 1400 VNET_LIST_RUNLOCK(); 1401 1402 rw_wlock(&tcp_function_lock); 1403 } 1404 if (blk->tfb_refcnt) { 1405 /* TCBs still attached. */ 1406 rw_wunlock(&tcp_function_lock); 1407 return (EBUSY); 1408 } 1409 if (quiesce) { 1410 /* Skip removal. */ 1411 rw_wunlock(&tcp_function_lock); 1412 return (0); 1413 } 1414 /* Remove any function names that map to this function block. */ 1415 while (find_tcp_fb_locked(blk, &f) != NULL) { 1416 TAILQ_REMOVE(&t_functions, f, tf_next); 1417 tcp_fb_cnt--; 1418 f->tf_fb = NULL; 1419 free(f, M_TCPFUNCTIONS); 1420 } 1421 rw_wunlock(&tcp_function_lock); 1422 return (0); 1423 } 1424 1425 static void 1426 tcp_drain(void) 1427 { 1428 struct epoch_tracker et; 1429 VNET_ITERATOR_DECL(vnet_iter); 1430 1431 if (!do_tcpdrain) 1432 return; 1433 1434 NET_EPOCH_ENTER(et); 1435 VNET_LIST_RLOCK_NOSLEEP(); 1436 VNET_FOREACH(vnet_iter) { 1437 CURVNET_SET(vnet_iter); 1438 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1439 INPLOOKUP_WLOCKPCB); 1440 struct inpcb *inpb; 1441 struct tcpcb *tcpb; 1442 1443 /* 1444 * Walk the tcpbs, if existing, and flush the reassembly queue, 1445 * if there is one... 1446 * XXX: The "Net/3" implementation doesn't imply that the TCP 1447 * reassembly queue should be flushed, but in a situation 1448 * where we're really low on mbufs, this is potentially 1449 * useful. 1450 */ 1451 while ((inpb = inp_next(&inpi)) != NULL) { 1452 if ((tcpb = intotcpcb(inpb)) != NULL) { 1453 tcp_reass_flush(tcpb); 1454 tcp_clean_sackreport(tcpb); 1455 #ifdef TCP_BLACKBOX 1456 tcp_log_drain(tcpb); 1457 #endif 1458 #ifdef TCPPCAP 1459 if (tcp_pcap_aggressive_free) { 1460 /* Free the TCP PCAP queues. */ 1461 tcp_pcap_drain(&(tcpb->t_inpkts)); 1462 tcp_pcap_drain(&(tcpb->t_outpkts)); 1463 } 1464 #endif 1465 } 1466 } 1467 CURVNET_RESTORE(); 1468 } 1469 VNET_LIST_RUNLOCK_NOSLEEP(); 1470 NET_EPOCH_EXIT(et); 1471 } 1472 1473 static void 1474 tcp_vnet_init(void *arg __unused) 1475 { 1476 1477 #ifdef TCP_HHOOK 1478 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1479 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1480 printf("%s: WARNING: unable to register helper hook\n", __func__); 1481 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1482 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1483 printf("%s: WARNING: unable to register helper hook\n", __func__); 1484 #endif 1485 #ifdef STATS 1486 if (tcp_stats_init()) 1487 printf("%s: WARNING: unable to initialise TCP stats\n", 1488 __func__); 1489 #endif 1490 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1491 tcp_tcbhashsize); 1492 1493 syncache_init(); 1494 tcp_hc_init(); 1495 1496 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1497 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1498 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1499 1500 tcp_fastopen_init(); 1501 1502 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1503 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1504 1505 V_tcp_msl = TCPTV_MSL; 1506 } 1507 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1508 tcp_vnet_init, NULL); 1509 1510 static void 1511 tcp_init(void *arg __unused) 1512 { 1513 const char *tcbhash_tuneable; 1514 int hashsize; 1515 1516 tcp_reass_global_init(); 1517 1518 /* XXX virtualize those below? */ 1519 tcp_delacktime = TCPTV_DELACK; 1520 tcp_keepinit = TCPTV_KEEP_INIT; 1521 tcp_keepidle = TCPTV_KEEP_IDLE; 1522 tcp_keepintvl = TCPTV_KEEPINTVL; 1523 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1524 tcp_rexmit_initial = TCPTV_RTOBASE; 1525 if (tcp_rexmit_initial < 1) 1526 tcp_rexmit_initial = 1; 1527 tcp_rexmit_min = TCPTV_MIN; 1528 if (tcp_rexmit_min < 1) 1529 tcp_rexmit_min = 1; 1530 tcp_persmin = TCPTV_PERSMIN; 1531 tcp_persmax = TCPTV_PERSMAX; 1532 tcp_rexmit_slop = TCPTV_CPU_VAR; 1533 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1534 1535 /* Setup the tcp function block list */ 1536 TAILQ_INIT(&t_functions); 1537 rw_init(&tcp_function_lock, "tcp_func_lock"); 1538 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1539 sx_init(&tcpoudp_lock, "TCP over UDP configuration"); 1540 #ifdef TCP_BLACKBOX 1541 /* Initialize the TCP logging data. */ 1542 tcp_log_init(); 1543 #endif 1544 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1545 1546 if (tcp_soreceive_stream) { 1547 #ifdef INET 1548 tcp_protosw.pr_soreceive = soreceive_stream; 1549 #endif 1550 #ifdef INET6 1551 tcp6_protosw.pr_soreceive = soreceive_stream; 1552 #endif /* INET6 */ 1553 } 1554 1555 #ifdef INET6 1556 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1557 #else /* INET6 */ 1558 max_protohdr_grow(sizeof(struct tcpiphdr)); 1559 #endif /* INET6 */ 1560 1561 ISN_LOCK_INIT(); 1562 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1563 SHUTDOWN_PRI_DEFAULT); 1564 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1565 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1566 1567 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1568 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1569 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1570 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1571 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1572 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1573 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1574 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1575 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1576 tcp_pacing_failures = counter_u64_alloc(M_WAITOK); 1577 #ifdef TCPPCAP 1578 tcp_pcap_init(); 1579 #endif 1580 1581 hashsize = TCBHASHSIZE; 1582 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 1583 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 1584 if (hashsize == 0) { 1585 /* 1586 * Auto tune the hash size based on maxsockets. 1587 * A perfect hash would have a 1:1 mapping 1588 * (hashsize = maxsockets) however it's been 1589 * suggested that O(2) average is better. 1590 */ 1591 hashsize = maketcp_hashsize(maxsockets / 4); 1592 /* 1593 * Our historical default is 512, 1594 * do not autotune lower than this. 1595 */ 1596 if (hashsize < 512) 1597 hashsize = 512; 1598 if (bootverbose) 1599 printf("%s: %s auto tuned to %d\n", __func__, 1600 tcbhash_tuneable, hashsize); 1601 } 1602 /* 1603 * We require a hashsize to be a power of two. 1604 * Previously if it was not a power of two we would just reset it 1605 * back to 512, which could be a nasty surprise if you did not notice 1606 * the error message. 1607 * Instead what we do is clip it to the closest power of two lower 1608 * than the specified hash value. 1609 */ 1610 if (!powerof2(hashsize)) { 1611 int oldhashsize = hashsize; 1612 1613 hashsize = maketcp_hashsize(hashsize); 1614 /* prevent absurdly low value */ 1615 if (hashsize < 16) 1616 hashsize = 16; 1617 printf("%s: WARNING: TCB hash size not a power of 2, " 1618 "clipped from %d to %d.\n", __func__, oldhashsize, 1619 hashsize); 1620 } 1621 tcp_tcbhashsize = hashsize; 1622 1623 #ifdef INET 1624 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1625 #endif 1626 #ifdef INET6 1627 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1628 #endif 1629 } 1630 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1631 1632 #ifdef VIMAGE 1633 static void 1634 tcp_destroy(void *unused __unused) 1635 { 1636 int n; 1637 #ifdef TCP_HHOOK 1638 int error; 1639 #endif 1640 1641 /* 1642 * All our processes are gone, all our sockets should be cleaned 1643 * up, which means, we should be past the tcp_discardcb() calls. 1644 * Sleep to let all tcpcb timers really disappear and cleanup. 1645 */ 1646 for (;;) { 1647 INP_INFO_WLOCK(&V_tcbinfo); 1648 n = V_tcbinfo.ipi_count; 1649 INP_INFO_WUNLOCK(&V_tcbinfo); 1650 if (n == 0) 1651 break; 1652 pause("tcpdes", hz / 10); 1653 } 1654 tcp_hc_destroy(); 1655 syncache_destroy(); 1656 in_pcbinfo_destroy(&V_tcbinfo); 1657 /* tcp_discardcb() clears the sack_holes up. */ 1658 uma_zdestroy(V_sack_hole_zone); 1659 1660 /* 1661 * Cannot free the zone until all tcpcbs are released as we attach 1662 * the allocations to them. 1663 */ 1664 tcp_fastopen_destroy(); 1665 1666 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1667 VNET_PCPUSTAT_FREE(tcpstat); 1668 1669 #ifdef TCP_HHOOK 1670 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1671 if (error != 0) { 1672 printf("%s: WARNING: unable to deregister helper hook " 1673 "type=%d, id=%d: error %d returned\n", __func__, 1674 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1675 } 1676 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 1677 if (error != 0) { 1678 printf("%s: WARNING: unable to deregister helper hook " 1679 "type=%d, id=%d: error %d returned\n", __func__, 1680 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 1681 } 1682 #endif 1683 } 1684 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1685 #endif 1686 1687 void 1688 tcp_fini(void *xtp) 1689 { 1690 1691 } 1692 1693 /* 1694 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1695 * tcp_template used to store this data in mbufs, but we now recopy it out 1696 * of the tcpcb each time to conserve mbufs. 1697 */ 1698 void 1699 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1700 { 1701 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1702 1703 INP_WLOCK_ASSERT(inp); 1704 1705 #ifdef INET6 1706 if ((inp->inp_vflag & INP_IPV6) != 0) { 1707 struct ip6_hdr *ip6; 1708 1709 ip6 = (struct ip6_hdr *)ip_ptr; 1710 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1711 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1712 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1713 (IPV6_VERSION & IPV6_VERSION_MASK); 1714 if (port == 0) 1715 ip6->ip6_nxt = IPPROTO_TCP; 1716 else 1717 ip6->ip6_nxt = IPPROTO_UDP; 1718 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1719 ip6->ip6_src = inp->in6p_laddr; 1720 ip6->ip6_dst = inp->in6p_faddr; 1721 } 1722 #endif /* INET6 */ 1723 #if defined(INET6) && defined(INET) 1724 else 1725 #endif 1726 #ifdef INET 1727 { 1728 struct ip *ip; 1729 1730 ip = (struct ip *)ip_ptr; 1731 ip->ip_v = IPVERSION; 1732 ip->ip_hl = 5; 1733 ip->ip_tos = inp->inp_ip_tos; 1734 ip->ip_len = 0; 1735 ip->ip_id = 0; 1736 ip->ip_off = 0; 1737 ip->ip_ttl = inp->inp_ip_ttl; 1738 ip->ip_sum = 0; 1739 if (port == 0) 1740 ip->ip_p = IPPROTO_TCP; 1741 else 1742 ip->ip_p = IPPROTO_UDP; 1743 ip->ip_src = inp->inp_laddr; 1744 ip->ip_dst = inp->inp_faddr; 1745 } 1746 #endif /* INET */ 1747 th->th_sport = inp->inp_lport; 1748 th->th_dport = inp->inp_fport; 1749 th->th_seq = 0; 1750 th->th_ack = 0; 1751 th->th_off = 5; 1752 tcp_set_flags(th, 0); 1753 th->th_win = 0; 1754 th->th_urp = 0; 1755 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1756 } 1757 1758 /* 1759 * Create template to be used to send tcp packets on a connection. 1760 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1761 * use for this function is in keepalives, which use tcp_respond. 1762 */ 1763 struct tcptemp * 1764 tcpip_maketemplate(struct inpcb *inp) 1765 { 1766 struct tcptemp *t; 1767 1768 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1769 if (t == NULL) 1770 return (NULL); 1771 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1772 return (t); 1773 } 1774 1775 /* 1776 * Send a single message to the TCP at address specified by 1777 * the given TCP/IP header. If m == NULL, then we make a copy 1778 * of the tcpiphdr at th and send directly to the addressed host. 1779 * This is used to force keep alive messages out using the TCP 1780 * template for a connection. If flags are given then we send 1781 * a message back to the TCP which originated the segment th, 1782 * and discard the mbuf containing it and any other attached mbufs. 1783 * 1784 * In any case the ack and sequence number of the transmitted 1785 * segment are as specified by the parameters. 1786 * 1787 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1788 */ 1789 void 1790 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1791 tcp_seq ack, tcp_seq seq, uint16_t flags) 1792 { 1793 struct tcpopt to; 1794 struct inpcb *inp; 1795 struct ip *ip; 1796 struct mbuf *optm; 1797 struct udphdr *uh = NULL; 1798 struct tcphdr *nth; 1799 struct tcp_log_buffer *lgb; 1800 u_char *optp; 1801 #ifdef INET6 1802 struct ip6_hdr *ip6; 1803 int isipv6; 1804 #endif /* INET6 */ 1805 int optlen, tlen, win, ulen; 1806 int ect = 0; 1807 bool incl_opts; 1808 uint16_t port; 1809 int output_ret; 1810 #ifdef INVARIANTS 1811 int thflags = tcp_get_flags(th); 1812 #endif 1813 1814 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1815 NET_EPOCH_ASSERT(); 1816 1817 #ifdef INET6 1818 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1819 ip6 = ipgen; 1820 #endif /* INET6 */ 1821 ip = ipgen; 1822 1823 if (tp != NULL) { 1824 inp = tptoinpcb(tp); 1825 INP_LOCK_ASSERT(inp); 1826 } else 1827 inp = NULL; 1828 1829 if (m != NULL) { 1830 #ifdef INET6 1831 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1832 port = m->m_pkthdr.tcp_tun_port; 1833 else 1834 #endif 1835 if (ip && (ip->ip_p == IPPROTO_UDP)) 1836 port = m->m_pkthdr.tcp_tun_port; 1837 else 1838 port = 0; 1839 } else 1840 port = tp->t_port; 1841 1842 incl_opts = false; 1843 win = 0; 1844 if (tp != NULL) { 1845 if (!(flags & TH_RST)) { 1846 win = sbspace(&inp->inp_socket->so_rcv); 1847 if (win > TCP_MAXWIN << tp->rcv_scale) 1848 win = TCP_MAXWIN << tp->rcv_scale; 1849 } 1850 if ((tp->t_flags & TF_NOOPT) == 0) 1851 incl_opts = true; 1852 } 1853 if (m == NULL) { 1854 m = m_gethdr(M_NOWAIT, MT_DATA); 1855 if (m == NULL) 1856 return; 1857 m->m_data += max_linkhdr; 1858 #ifdef INET6 1859 if (isipv6) { 1860 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1861 sizeof(struct ip6_hdr)); 1862 ip6 = mtod(m, struct ip6_hdr *); 1863 nth = (struct tcphdr *)(ip6 + 1); 1864 if (port) { 1865 /* Insert a UDP header */ 1866 uh = (struct udphdr *)nth; 1867 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1868 uh->uh_dport = port; 1869 nth = (struct tcphdr *)(uh + 1); 1870 } 1871 } else 1872 #endif /* INET6 */ 1873 { 1874 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1875 ip = mtod(m, struct ip *); 1876 nth = (struct tcphdr *)(ip + 1); 1877 if (port) { 1878 /* Insert a UDP header */ 1879 uh = (struct udphdr *)nth; 1880 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1881 uh->uh_dport = port; 1882 nth = (struct tcphdr *)(uh + 1); 1883 } 1884 } 1885 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1886 flags = TH_ACK; 1887 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1888 struct mbuf *n; 1889 1890 /* Can't reuse 'm', allocate a new mbuf. */ 1891 n = m_gethdr(M_NOWAIT, MT_DATA); 1892 if (n == NULL) { 1893 m_freem(m); 1894 return; 1895 } 1896 1897 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1898 m_freem(m); 1899 m_freem(n); 1900 return; 1901 } 1902 1903 n->m_data += max_linkhdr; 1904 /* m_len is set later */ 1905 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1906 #ifdef INET6 1907 if (isipv6) { 1908 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1909 sizeof(struct ip6_hdr)); 1910 ip6 = mtod(n, struct ip6_hdr *); 1911 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1912 nth = (struct tcphdr *)(ip6 + 1); 1913 if (port) { 1914 /* Insert a UDP header */ 1915 uh = (struct udphdr *)nth; 1916 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1917 uh->uh_dport = port; 1918 nth = (struct tcphdr *)(uh + 1); 1919 } 1920 } else 1921 #endif /* INET6 */ 1922 { 1923 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1924 ip = mtod(n, struct ip *); 1925 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1926 nth = (struct tcphdr *)(ip + 1); 1927 if (port) { 1928 /* Insert a UDP header */ 1929 uh = (struct udphdr *)nth; 1930 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1931 uh->uh_dport = port; 1932 nth = (struct tcphdr *)(uh + 1); 1933 } 1934 } 1935 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1936 xchg(nth->th_dport, nth->th_sport, uint16_t); 1937 th = nth; 1938 m_freem(m); 1939 m = n; 1940 } else { 1941 /* 1942 * reuse the mbuf. 1943 * XXX MRT We inherit the FIB, which is lucky. 1944 */ 1945 m_freem(m->m_next); 1946 m->m_next = NULL; 1947 m->m_data = (caddr_t)ipgen; 1948 /* clear any receive flags for proper bpf timestamping */ 1949 m->m_flags &= ~(M_TSTMP | M_TSTMP_LRO); 1950 /* m_len is set later */ 1951 #ifdef INET6 1952 if (isipv6) { 1953 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1954 nth = (struct tcphdr *)(ip6 + 1); 1955 } else 1956 #endif /* INET6 */ 1957 { 1958 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1959 nth = (struct tcphdr *)(ip + 1); 1960 } 1961 if (th != nth) { 1962 /* 1963 * this is usually a case when an extension header 1964 * exists between the IPv6 header and the 1965 * TCP header. 1966 */ 1967 nth->th_sport = th->th_sport; 1968 nth->th_dport = th->th_dport; 1969 } 1970 xchg(nth->th_dport, nth->th_sport, uint16_t); 1971 #undef xchg 1972 } 1973 tlen = 0; 1974 #ifdef INET6 1975 if (isipv6) 1976 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1977 #endif 1978 #if defined(INET) && defined(INET6) 1979 else 1980 #endif 1981 #ifdef INET 1982 tlen = sizeof (struct tcpiphdr); 1983 #endif 1984 if (port) 1985 tlen += sizeof (struct udphdr); 1986 #ifdef INVARIANTS 1987 m->m_len = 0; 1988 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1989 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1990 m, tlen, (long)M_TRAILINGSPACE(m))); 1991 #endif 1992 m->m_len = tlen; 1993 to.to_flags = 0; 1994 if (incl_opts) { 1995 ect = tcp_ecn_output_established(tp, &flags, 0, false); 1996 /* Make sure we have room. */ 1997 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1998 m->m_next = m_get(M_NOWAIT, MT_DATA); 1999 if (m->m_next) { 2000 optp = mtod(m->m_next, u_char *); 2001 optm = m->m_next; 2002 } else 2003 incl_opts = false; 2004 } else { 2005 optp = (u_char *) (nth + 1); 2006 optm = m; 2007 } 2008 } 2009 if (incl_opts) { 2010 /* Timestamps. */ 2011 if (tp->t_flags & TF_RCVD_TSTMP) { 2012 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 2013 to.to_tsecr = tp->ts_recent; 2014 to.to_flags |= TOF_TS; 2015 } 2016 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2017 /* TCP-MD5 (RFC2385). */ 2018 if (tp->t_flags & TF_SIGNATURE) 2019 to.to_flags |= TOF_SIGNATURE; 2020 #endif 2021 /* Add the options. */ 2022 tlen += optlen = tcp_addoptions(&to, optp); 2023 2024 /* Update m_len in the correct mbuf. */ 2025 optm->m_len += optlen; 2026 } else 2027 optlen = 0; 2028 #ifdef INET6 2029 if (isipv6) { 2030 if (uh) { 2031 ulen = tlen - sizeof(struct ip6_hdr); 2032 uh->uh_ulen = htons(ulen); 2033 } 2034 ip6->ip6_flow = htonl(ect << IPV6_FLOWLABEL_LEN); 2035 ip6->ip6_vfc = IPV6_VERSION; 2036 if (port) 2037 ip6->ip6_nxt = IPPROTO_UDP; 2038 else 2039 ip6->ip6_nxt = IPPROTO_TCP; 2040 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 2041 } 2042 #endif 2043 #if defined(INET) && defined(INET6) 2044 else 2045 #endif 2046 #ifdef INET 2047 { 2048 if (uh) { 2049 ulen = tlen - sizeof(struct ip); 2050 uh->uh_ulen = htons(ulen); 2051 } 2052 ip->ip_len = htons(tlen); 2053 if (inp != NULL) { 2054 ip->ip_tos = inp->inp_ip_tos & ~IPTOS_ECN_MASK; 2055 ip->ip_ttl = inp->inp_ip_ttl; 2056 } else { 2057 ip->ip_tos = 0; 2058 ip->ip_ttl = V_ip_defttl; 2059 } 2060 ip->ip_tos |= ect; 2061 if (port) { 2062 ip->ip_p = IPPROTO_UDP; 2063 } else { 2064 ip->ip_p = IPPROTO_TCP; 2065 } 2066 if (V_path_mtu_discovery) 2067 ip->ip_off |= htons(IP_DF); 2068 } 2069 #endif 2070 m->m_pkthdr.len = tlen; 2071 m->m_pkthdr.rcvif = NULL; 2072 #ifdef MAC 2073 if (inp != NULL) { 2074 /* 2075 * Packet is associated with a socket, so allow the 2076 * label of the response to reflect the socket label. 2077 */ 2078 INP_LOCK_ASSERT(inp); 2079 mac_inpcb_create_mbuf(inp, m); 2080 } else { 2081 /* 2082 * Packet is not associated with a socket, so possibly 2083 * update the label in place. 2084 */ 2085 mac_netinet_tcp_reply(m); 2086 } 2087 #endif 2088 nth->th_seq = htonl(seq); 2089 nth->th_ack = htonl(ack); 2090 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2091 tcp_set_flags(nth, flags); 2092 if (tp && (flags & TH_RST)) { 2093 /* Log the reset */ 2094 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST); 2095 } 2096 if (tp != NULL) 2097 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2098 else 2099 nth->th_win = htons((u_short)win); 2100 nth->th_urp = 0; 2101 2102 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2103 if (to.to_flags & TOF_SIGNATURE) { 2104 if (!TCPMD5_ENABLED() || 2105 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2106 m_freem(m); 2107 return; 2108 } 2109 } 2110 #endif 2111 2112 #ifdef INET6 2113 if (isipv6) { 2114 if (port) { 2115 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2116 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2117 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2118 nth->th_sum = 0; 2119 } else { 2120 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2121 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2122 nth->th_sum = in6_cksum_pseudo(ip6, 2123 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2124 } 2125 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 2126 } 2127 #endif /* INET6 */ 2128 #if defined(INET6) && defined(INET) 2129 else 2130 #endif 2131 #ifdef INET 2132 { 2133 if (port) { 2134 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2135 htons(ulen + IPPROTO_UDP)); 2136 m->m_pkthdr.csum_flags = CSUM_UDP; 2137 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2138 nth->th_sum = 0; 2139 } else { 2140 m->m_pkthdr.csum_flags = CSUM_TCP; 2141 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2142 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2143 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2144 } 2145 } 2146 #endif /* INET */ 2147 TCP_PROBE3(debug__output, tp, th, m); 2148 if (flags & TH_RST) 2149 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2150 lgb = NULL; 2151 if ((tp != NULL) && tcp_bblogging_on(tp)) { 2152 if (INP_WLOCKED(inp)) { 2153 union tcp_log_stackspecific log; 2154 struct timeval tv; 2155 2156 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2157 log.u_bbr.inhpts = tcp_in_hpts(tp); 2158 log.u_bbr.flex8 = 4; 2159 log.u_bbr.pkts_out = tp->t_maxseg; 2160 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2161 log.u_bbr.delivered = 0; 2162 lgb = tcp_log_event(tp, nth, NULL, NULL, TCP_LOG_OUT, 2163 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2164 } else { 2165 /* 2166 * We can not log the packet, since we only own the 2167 * read lock, but a write lock is needed. The read lock 2168 * is not upgraded to a write lock, since only getting 2169 * the read lock was done intentionally to improve the 2170 * handling of SYN flooding attacks. 2171 * This happens only for pure SYN segments received in 2172 * the initial CLOSED state, or received in a more 2173 * advanced state than listen and the UDP encapsulation 2174 * port is unexpected. 2175 * The incoming SYN segments do not really belong to 2176 * the TCP connection and the handling does not change 2177 * the state of the TCP connection. Therefore, the 2178 * sending of the RST segments is not logged. Please 2179 * note that also the incoming SYN segments are not 2180 * logged. 2181 * 2182 * The following code ensures that the above description 2183 * is and stays correct. 2184 */ 2185 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2186 (tp->t_state == TCPS_CLOSED || 2187 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2188 ("%s: Logging of TCP segment with flags 0x%b and " 2189 "UDP encapsulation port %u skipped in state %s", 2190 __func__, thflags, PRINT_TH_FLAGS, 2191 ntohs(port), tcpstates[tp->t_state])); 2192 } 2193 } 2194 2195 if (flags & TH_ACK) 2196 TCPSTAT_INC(tcps_sndacks); 2197 else if (flags & (TH_SYN|TH_FIN|TH_RST)) 2198 TCPSTAT_INC(tcps_sndctrl); 2199 TCPSTAT_INC(tcps_sndtotal); 2200 2201 #ifdef INET6 2202 if (isipv6) { 2203 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2204 output_ret = ip6_output(m, inp ? inp->in6p_outputopts : NULL, 2205 NULL, 0, NULL, NULL, inp); 2206 } 2207 #endif /* INET6 */ 2208 #if defined(INET) && defined(INET6) 2209 else 2210 #endif 2211 #ifdef INET 2212 { 2213 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2214 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2215 } 2216 #endif 2217 if (lgb != NULL) 2218 lgb->tlb_errno = output_ret; 2219 } 2220 2221 /* 2222 * Create a new TCP control block, making an empty reassembly queue and hooking 2223 * it to the argument protocol control block. The `inp' parameter must have 2224 * come from the zone allocator set up by tcpcbstor declaration. 2225 */ 2226 struct tcpcb * 2227 tcp_newtcpcb(struct inpcb *inp) 2228 { 2229 struct tcpcb *tp = intotcpcb(inp); 2230 #ifdef INET6 2231 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2232 #endif /* INET6 */ 2233 2234 /* 2235 * Historically allocation was done with M_ZERO. There is a lot of 2236 * code that rely on that. For now take safe approach and zero whole 2237 * tcpcb. This definitely can be optimized. 2238 */ 2239 bzero(&tp->t_start_zero, t_zero_size); 2240 2241 /* Initialise cc_var struct for this tcpcb. */ 2242 tp->t_ccv.type = IPPROTO_TCP; 2243 tp->t_ccv.ccvc.tcp = tp; 2244 rw_rlock(&tcp_function_lock); 2245 tp->t_fb = V_tcp_func_set_ptr; 2246 refcount_acquire(&tp->t_fb->tfb_refcnt); 2247 rw_runlock(&tcp_function_lock); 2248 /* 2249 * Use the current system default CC algorithm. 2250 */ 2251 cc_attach(tp, CC_DEFAULT_ALGO()); 2252 2253 if (CC_ALGO(tp)->cb_init != NULL) 2254 if (CC_ALGO(tp)->cb_init(&tp->t_ccv, NULL) > 0) { 2255 cc_detach(tp); 2256 if (tp->t_fb->tfb_tcp_fb_fini) 2257 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2258 refcount_release(&tp->t_fb->tfb_refcnt); 2259 return (NULL); 2260 } 2261 2262 #ifdef TCP_HHOOK 2263 if (khelp_init_osd(HELPER_CLASS_TCP, &tp->t_osd)) { 2264 if (tp->t_fb->tfb_tcp_fb_fini) 2265 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2266 refcount_release(&tp->t_fb->tfb_refcnt); 2267 return (NULL); 2268 } 2269 #endif 2270 2271 TAILQ_INIT(&tp->t_segq); 2272 STAILQ_INIT(&tp->t_inqueue); 2273 tp->t_maxseg = 2274 #ifdef INET6 2275 isipv6 ? V_tcp_v6mssdflt : 2276 #endif /* INET6 */ 2277 V_tcp_mssdflt; 2278 2279 /* All mbuf queue/ack compress flags should be off */ 2280 tcp_lro_features_off(tp); 2281 2282 callout_init_rw(&tp->t_callout, &inp->inp_lock, CALLOUT_RETURNUNLOCKED); 2283 for (int i = 0; i < TT_N; i++) 2284 tp->t_timers[i] = SBT_MAX; 2285 2286 switch (V_tcp_do_rfc1323) { 2287 case 0: 2288 break; 2289 default: 2290 case 1: 2291 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2292 break; 2293 case 2: 2294 tp->t_flags = TF_REQ_SCALE; 2295 break; 2296 case 3: 2297 tp->t_flags = TF_REQ_TSTMP; 2298 break; 2299 } 2300 if (V_tcp_do_sack) 2301 tp->t_flags |= TF_SACK_PERMIT; 2302 TAILQ_INIT(&tp->snd_holes); 2303 2304 /* 2305 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2306 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2307 * reasonable initial retransmit time. 2308 */ 2309 tp->t_srtt = TCPTV_SRTTBASE; 2310 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2311 tp->t_rttmin = tcp_rexmit_min; 2312 tp->t_rxtcur = tcp_rexmit_initial; 2313 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2314 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2315 tp->t_rcvtime = ticks; 2316 /* We always start with ticks granularity */ 2317 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS; 2318 /* 2319 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2320 * because the socket may be bound to an IPv6 wildcard address, 2321 * which may match an IPv4-mapped IPv6 address. 2322 */ 2323 inp->inp_ip_ttl = V_ip_defttl; 2324 #ifdef TCPHPTS 2325 tcp_hpts_init(tp); 2326 #endif 2327 #ifdef TCPPCAP 2328 /* 2329 * Init the TCP PCAP queues. 2330 */ 2331 tcp_pcap_tcpcb_init(tp); 2332 #endif 2333 #ifdef TCP_BLACKBOX 2334 /* Initialize the per-TCPCB log data. */ 2335 tcp_log_tcpcbinit(tp); 2336 #endif 2337 tp->t_pacing_rate = -1; 2338 if (tp->t_fb->tfb_tcp_fb_init) { 2339 if ((*tp->t_fb->tfb_tcp_fb_init)(tp, &tp->t_fb_ptr)) { 2340 refcount_release(&tp->t_fb->tfb_refcnt); 2341 return (NULL); 2342 } 2343 } 2344 #ifdef STATS 2345 if (V_tcp_perconn_stats_enable == 1) 2346 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2347 #endif 2348 if (V_tcp_do_lrd) 2349 tp->t_flags |= TF_LRD; 2350 2351 return (tp); 2352 } 2353 2354 /* 2355 * Drop a TCP connection, reporting 2356 * the specified error. If connection is synchronized, 2357 * then send a RST to peer. 2358 */ 2359 struct tcpcb * 2360 tcp_drop(struct tcpcb *tp, int errno) 2361 { 2362 struct socket *so = tptosocket(tp); 2363 2364 NET_EPOCH_ASSERT(); 2365 INP_WLOCK_ASSERT(tptoinpcb(tp)); 2366 2367 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2368 tcp_state_change(tp, TCPS_CLOSED); 2369 /* Don't use tcp_output() here due to possible recursion. */ 2370 (void)tcp_output_nodrop(tp); 2371 TCPSTAT_INC(tcps_drops); 2372 } else 2373 TCPSTAT_INC(tcps_conndrops); 2374 if (errno == ETIMEDOUT && tp->t_softerror) 2375 errno = tp->t_softerror; 2376 so->so_error = errno; 2377 return (tcp_close(tp)); 2378 } 2379 2380 void 2381 tcp_discardcb(struct tcpcb *tp) 2382 { 2383 struct inpcb *inp = tptoinpcb(tp); 2384 struct socket *so = tptosocket(tp); 2385 struct mbuf *m; 2386 #ifdef INET6 2387 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2388 #endif 2389 2390 INP_WLOCK_ASSERT(inp); 2391 2392 tcp_timer_stop(tp); 2393 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2394 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2395 } 2396 2397 /* free the reassembly queue, if any */ 2398 tcp_reass_flush(tp); 2399 2400 #ifdef TCP_OFFLOAD 2401 /* Disconnect offload device, if any. */ 2402 if (tp->t_flags & TF_TOE) 2403 tcp_offload_detach(tp); 2404 #endif 2405 2406 tcp_free_sackholes(tp); 2407 2408 #ifdef TCPPCAP 2409 /* Free the TCP PCAP queues. */ 2410 tcp_pcap_drain(&(tp->t_inpkts)); 2411 tcp_pcap_drain(&(tp->t_outpkts)); 2412 #endif 2413 2414 /* Allow the CC algorithm to clean up after itself. */ 2415 if (CC_ALGO(tp)->cb_destroy != NULL) 2416 CC_ALGO(tp)->cb_destroy(&tp->t_ccv); 2417 CC_DATA(tp) = NULL; 2418 /* Detach from the CC algorithm */ 2419 cc_detach(tp); 2420 2421 #ifdef TCP_HHOOK 2422 khelp_destroy_osd(&tp->t_osd); 2423 #endif 2424 #ifdef STATS 2425 stats_blob_destroy(tp->t_stats); 2426 #endif 2427 2428 CC_ALGO(tp) = NULL; 2429 if ((m = STAILQ_FIRST(&tp->t_inqueue)) != NULL) { 2430 struct mbuf *prev; 2431 2432 STAILQ_INIT(&tp->t_inqueue); 2433 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, prev) 2434 m_freem(m); 2435 } 2436 TCPSTATES_DEC(tp->t_state); 2437 2438 if (tp->t_fb->tfb_tcp_fb_fini) 2439 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2440 MPASS(!tcp_in_hpts(tp)); 2441 #ifdef TCP_BLACKBOX 2442 tcp_log_tcpcbfini(tp); 2443 #endif 2444 2445 /* 2446 * If we got enough samples through the srtt filter, 2447 * save the rtt and rttvar in the routing entry. 2448 * 'Enough' is arbitrarily defined as 4 rtt samples. 2449 * 4 samples is enough for the srtt filter to converge 2450 * to within enough % of the correct value; fewer samples 2451 * and we could save a bogus rtt. The danger is not high 2452 * as tcp quickly recovers from everything. 2453 * XXX: Works very well but needs some more statistics! 2454 * 2455 * XXXRRS: Updating must be after the stack fini() since 2456 * that may be converting some internal representation of 2457 * say srtt etc into the general one used by other stacks. 2458 * Lets also at least protect against the so being NULL 2459 * as RW stated below. 2460 */ 2461 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2462 struct hc_metrics_lite metrics; 2463 uint32_t ssthresh; 2464 2465 bzero(&metrics, sizeof(metrics)); 2466 /* 2467 * Update the ssthresh always when the conditions below 2468 * are satisfied. This gives us better new start value 2469 * for the congestion avoidance for new connections. 2470 * ssthresh is only set if packet loss occurred on a session. 2471 * 2472 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2473 * being torn down. Ideally this code would not use 'so'. 2474 */ 2475 ssthresh = tp->snd_ssthresh; 2476 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2477 /* 2478 * convert the limit from user data bytes to 2479 * packets then to packet data bytes. 2480 */ 2481 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2482 if (ssthresh < 2) 2483 ssthresh = 2; 2484 ssthresh *= (tp->t_maxseg + 2485 #ifdef INET6 2486 (isipv6 ? sizeof (struct ip6_hdr) + 2487 sizeof (struct tcphdr) : 2488 #endif 2489 sizeof (struct tcpiphdr) 2490 #ifdef INET6 2491 ) 2492 #endif 2493 ); 2494 } else 2495 ssthresh = 0; 2496 metrics.rmx_ssthresh = ssthresh; 2497 2498 metrics.rmx_rtt = tp->t_srtt; 2499 metrics.rmx_rttvar = tp->t_rttvar; 2500 metrics.rmx_cwnd = tp->snd_cwnd; 2501 metrics.rmx_sendpipe = 0; 2502 metrics.rmx_recvpipe = 0; 2503 2504 tcp_hc_update(&inp->inp_inc, &metrics); 2505 } 2506 2507 refcount_release(&tp->t_fb->tfb_refcnt); 2508 } 2509 2510 /* 2511 * Attempt to close a TCP control block, marking it as dropped, and freeing 2512 * the socket if we hold the only reference. 2513 */ 2514 struct tcpcb * 2515 tcp_close(struct tcpcb *tp) 2516 { 2517 struct inpcb *inp = tptoinpcb(tp); 2518 struct socket *so = tptosocket(tp); 2519 2520 INP_WLOCK_ASSERT(inp); 2521 2522 #ifdef TCP_OFFLOAD 2523 if (tp->t_state == TCPS_LISTEN) 2524 tcp_offload_listen_stop(tp); 2525 #endif 2526 /* 2527 * This releases the TFO pending counter resource for TFO listen 2528 * sockets as well as passively-created TFO sockets that transition 2529 * from SYN_RECEIVED to CLOSED. 2530 */ 2531 if (tp->t_tfo_pending) { 2532 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2533 tp->t_tfo_pending = NULL; 2534 } 2535 #ifdef TCPHPTS 2536 tcp_hpts_remove(tp); 2537 #endif 2538 in_pcbdrop(inp); 2539 TCPSTAT_INC(tcps_closed); 2540 if (tp->t_state != TCPS_CLOSED) 2541 tcp_state_change(tp, TCPS_CLOSED); 2542 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2543 soisdisconnected(so); 2544 if (inp->inp_flags & INP_SOCKREF) { 2545 inp->inp_flags &= ~INP_SOCKREF; 2546 INP_WUNLOCK(inp); 2547 sorele(so); 2548 return (NULL); 2549 } 2550 return (tp); 2551 } 2552 2553 /* 2554 * Notify a tcp user of an asynchronous error; 2555 * store error as soft error, but wake up user 2556 * (for now, won't do anything until can select for soft error). 2557 * 2558 * Do not wake up user since there currently is no mechanism for 2559 * reporting soft errors (yet - a kqueue filter may be added). 2560 */ 2561 static struct inpcb * 2562 tcp_notify(struct inpcb *inp, int error) 2563 { 2564 struct tcpcb *tp; 2565 2566 INP_WLOCK_ASSERT(inp); 2567 2568 tp = intotcpcb(inp); 2569 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2570 2571 /* 2572 * Ignore some errors if we are hooked up. 2573 * If connection hasn't completed, has retransmitted several times, 2574 * and receives a second error, give up now. This is better 2575 * than waiting a long time to establish a connection that 2576 * can never complete. 2577 */ 2578 if (tp->t_state == TCPS_ESTABLISHED && 2579 (error == EHOSTUNREACH || error == ENETUNREACH || 2580 error == EHOSTDOWN)) { 2581 if (inp->inp_route.ro_nh) { 2582 NH_FREE(inp->inp_route.ro_nh); 2583 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2584 } 2585 return (inp); 2586 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2587 tp->t_softerror) { 2588 tp = tcp_drop(tp, error); 2589 if (tp != NULL) 2590 return (inp); 2591 else 2592 return (NULL); 2593 } else { 2594 tp->t_softerror = error; 2595 return (inp); 2596 } 2597 #if 0 2598 wakeup( &so->so_timeo); 2599 sorwakeup(so); 2600 sowwakeup(so); 2601 #endif 2602 } 2603 2604 static int 2605 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2606 { 2607 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2608 INPLOOKUP_RLOCKPCB); 2609 struct xinpgen xig; 2610 struct inpcb *inp; 2611 int error; 2612 2613 if (req->newptr != NULL) 2614 return (EPERM); 2615 2616 if (req->oldptr == NULL) { 2617 int n; 2618 2619 n = V_tcbinfo.ipi_count + 2620 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2621 n += imax(n / 8, 10); 2622 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2623 return (0); 2624 } 2625 2626 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2627 return (error); 2628 2629 bzero(&xig, sizeof(xig)); 2630 xig.xig_len = sizeof xig; 2631 xig.xig_count = V_tcbinfo.ipi_count + 2632 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2633 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2634 xig.xig_sogen = so_gencnt; 2635 error = SYSCTL_OUT(req, &xig, sizeof xig); 2636 if (error) 2637 return (error); 2638 2639 error = syncache_pcblist(req); 2640 if (error) 2641 return (error); 2642 2643 while ((inp = inp_next(&inpi)) != NULL) { 2644 if (inp->inp_gencnt <= xig.xig_gen && 2645 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 2646 struct xtcpcb xt; 2647 2648 tcp_inptoxtp(inp, &xt); 2649 error = SYSCTL_OUT(req, &xt, sizeof xt); 2650 if (error) { 2651 INP_RUNLOCK(inp); 2652 break; 2653 } else 2654 continue; 2655 } 2656 } 2657 2658 if (!error) { 2659 /* 2660 * Give the user an updated idea of our state. 2661 * If the generation differs from what we told 2662 * her before, she knows that something happened 2663 * while we were processing this request, and it 2664 * might be necessary to retry. 2665 */ 2666 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2667 xig.xig_sogen = so_gencnt; 2668 xig.xig_count = V_tcbinfo.ipi_count + 2669 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2670 error = SYSCTL_OUT(req, &xig, sizeof xig); 2671 } 2672 2673 return (error); 2674 } 2675 2676 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2677 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2678 NULL, 0, tcp_pcblist, "S,xtcpcb", 2679 "List of active TCP connections"); 2680 2681 #ifdef INET 2682 static int 2683 tcp_getcred(SYSCTL_HANDLER_ARGS) 2684 { 2685 struct xucred xuc; 2686 struct sockaddr_in addrs[2]; 2687 struct epoch_tracker et; 2688 struct inpcb *inp; 2689 int error; 2690 2691 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2692 if (error) 2693 return (error); 2694 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2695 if (error) 2696 return (error); 2697 NET_EPOCH_ENTER(et); 2698 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2699 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2700 NET_EPOCH_EXIT(et); 2701 if (inp != NULL) { 2702 if (error == 0) 2703 error = cr_canseeinpcb(req->td->td_ucred, inp); 2704 if (error == 0) 2705 cru2x(inp->inp_cred, &xuc); 2706 INP_RUNLOCK(inp); 2707 } else 2708 error = ENOENT; 2709 if (error == 0) 2710 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2711 return (error); 2712 } 2713 2714 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2715 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2716 0, 0, tcp_getcred, "S,xucred", 2717 "Get the xucred of a TCP connection"); 2718 #endif /* INET */ 2719 2720 #ifdef INET6 2721 static int 2722 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2723 { 2724 struct epoch_tracker et; 2725 struct xucred xuc; 2726 struct sockaddr_in6 addrs[2]; 2727 struct inpcb *inp; 2728 int error; 2729 #ifdef INET 2730 int mapped = 0; 2731 #endif 2732 2733 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2734 if (error) 2735 return (error); 2736 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2737 if (error) 2738 return (error); 2739 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2740 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2741 return (error); 2742 } 2743 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2744 #ifdef INET 2745 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2746 mapped = 1; 2747 else 2748 #endif 2749 return (EINVAL); 2750 } 2751 2752 NET_EPOCH_ENTER(et); 2753 #ifdef INET 2754 if (mapped == 1) 2755 inp = in_pcblookup(&V_tcbinfo, 2756 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2757 addrs[1].sin6_port, 2758 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2759 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2760 else 2761 #endif 2762 inp = in6_pcblookup(&V_tcbinfo, 2763 &addrs[1].sin6_addr, addrs[1].sin6_port, 2764 &addrs[0].sin6_addr, addrs[0].sin6_port, 2765 INPLOOKUP_RLOCKPCB, NULL); 2766 NET_EPOCH_EXIT(et); 2767 if (inp != NULL) { 2768 if (error == 0) 2769 error = cr_canseeinpcb(req->td->td_ucred, inp); 2770 if (error == 0) 2771 cru2x(inp->inp_cred, &xuc); 2772 INP_RUNLOCK(inp); 2773 } else 2774 error = ENOENT; 2775 if (error == 0) 2776 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2777 return (error); 2778 } 2779 2780 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2781 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2782 0, 0, tcp6_getcred, "S,xucred", 2783 "Get the xucred of a TCP6 connection"); 2784 #endif /* INET6 */ 2785 2786 #ifdef INET 2787 /* Path MTU to try next when a fragmentation-needed message is received. */ 2788 static inline int 2789 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2790 { 2791 int mtu = ntohs(icp->icmp_nextmtu); 2792 2793 /* If no alternative MTU was proposed, try the next smaller one. */ 2794 if (!mtu) 2795 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2796 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2797 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2798 2799 return (mtu); 2800 } 2801 2802 static void 2803 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port) 2804 { 2805 struct ip *ip; 2806 struct tcphdr *th; 2807 struct inpcb *inp; 2808 struct tcpcb *tp; 2809 struct inpcb *(*notify)(struct inpcb *, int); 2810 struct in_conninfo inc; 2811 tcp_seq icmp_tcp_seq; 2812 int errno, mtu; 2813 2814 errno = icmp_errmap(icp); 2815 switch (errno) { 2816 case 0: 2817 return; 2818 case EMSGSIZE: 2819 notify = tcp_mtudisc_notify; 2820 break; 2821 case ECONNREFUSED: 2822 if (V_icmp_may_rst) 2823 notify = tcp_drop_syn_sent; 2824 else 2825 notify = tcp_notify; 2826 break; 2827 case EHOSTUNREACH: 2828 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED) 2829 notify = tcp_drop_syn_sent; 2830 else 2831 notify = tcp_notify; 2832 break; 2833 default: 2834 notify = tcp_notify; 2835 } 2836 2837 ip = &icp->icmp_ip; 2838 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2839 icmp_tcp_seq = th->th_seq; 2840 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src, 2841 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2842 if (inp != NULL) { 2843 tp = intotcpcb(inp); 2844 #ifdef TCP_OFFLOAD 2845 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2846 /* 2847 * MTU discovery for offloaded connections. Let 2848 * the TOE driver verify seq# and process it. 2849 */ 2850 mtu = tcp_next_pmtu(icp, ip); 2851 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2852 goto out; 2853 } 2854 #endif 2855 if (tp->t_port != port) 2856 goto out; 2857 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2858 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2859 if (errno == EMSGSIZE) { 2860 /* 2861 * MTU discovery: we got a needfrag and 2862 * will potentially try a lower MTU. 2863 */ 2864 mtu = tcp_next_pmtu(icp, ip); 2865 2866 /* 2867 * Only process the offered MTU if it 2868 * is smaller than the current one. 2869 */ 2870 if (mtu < tp->t_maxseg + 2871 sizeof(struct tcpiphdr)) { 2872 bzero(&inc, sizeof(inc)); 2873 inc.inc_faddr = ip->ip_dst; 2874 inc.inc_fibnum = 2875 inp->inp_inc.inc_fibnum; 2876 tcp_hc_updatemtu(&inc, mtu); 2877 inp = tcp_mtudisc(inp, mtu); 2878 } 2879 } else 2880 inp = (*notify)(inp, errno); 2881 } 2882 } else { 2883 bzero(&inc, sizeof(inc)); 2884 inc.inc_fport = th->th_dport; 2885 inc.inc_lport = th->th_sport; 2886 inc.inc_faddr = ip->ip_dst; 2887 inc.inc_laddr = ip->ip_src; 2888 syncache_unreach(&inc, icmp_tcp_seq, port); 2889 } 2890 out: 2891 if (inp != NULL) 2892 INP_WUNLOCK(inp); 2893 } 2894 2895 static void 2896 tcp_ctlinput(struct icmp *icmp) 2897 { 2898 tcp_ctlinput_with_port(icmp, htons(0)); 2899 } 2900 2901 static void 2902 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param) 2903 { 2904 /* Its a tunneled TCP over UDP icmp */ 2905 struct icmp *icmp = param.icmp; 2906 struct ip *outer_ip, *inner_ip; 2907 struct udphdr *udp; 2908 struct tcphdr *th, ttemp; 2909 int i_hlen, o_len; 2910 uint16_t port; 2911 2912 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2913 inner_ip = &icmp->icmp_ip; 2914 i_hlen = inner_ip->ip_hl << 2; 2915 o_len = ntohs(outer_ip->ip_len); 2916 if (o_len < 2917 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2918 /* Not enough data present */ 2919 return; 2920 } 2921 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2922 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2923 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2924 return; 2925 } 2926 port = udp->uh_dport; 2927 th = (struct tcphdr *)(udp + 1); 2928 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2929 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2930 /* Now adjust down the size of the outer IP header */ 2931 o_len -= sizeof(struct udphdr); 2932 outer_ip->ip_len = htons(o_len); 2933 /* Now call in to the normal handling code */ 2934 tcp_ctlinput_with_port(icmp, port); 2935 } 2936 #endif /* INET */ 2937 2938 #ifdef INET6 2939 static inline int 2940 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2941 { 2942 int mtu = ntohl(icmp6->icmp6_mtu); 2943 2944 /* 2945 * If no alternative MTU was proposed, or the proposed MTU was too 2946 * small, set to the min. 2947 */ 2948 if (mtu < IPV6_MMTU) 2949 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2950 return (mtu); 2951 } 2952 2953 static void 2954 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port) 2955 { 2956 struct in6_addr *dst; 2957 struct inpcb *(*notify)(struct inpcb *, int); 2958 struct ip6_hdr *ip6; 2959 struct mbuf *m; 2960 struct inpcb *inp; 2961 struct tcpcb *tp; 2962 struct icmp6_hdr *icmp6; 2963 struct in_conninfo inc; 2964 struct tcp_ports { 2965 uint16_t th_sport; 2966 uint16_t th_dport; 2967 } t_ports; 2968 tcp_seq icmp_tcp_seq; 2969 unsigned int mtu; 2970 unsigned int off; 2971 int errno; 2972 2973 icmp6 = ip6cp->ip6c_icmp6; 2974 m = ip6cp->ip6c_m; 2975 ip6 = ip6cp->ip6c_ip6; 2976 off = ip6cp->ip6c_off; 2977 dst = &ip6cp->ip6c_finaldst->sin6_addr; 2978 2979 errno = icmp6_errmap(icmp6); 2980 switch (errno) { 2981 case 0: 2982 return; 2983 case EMSGSIZE: 2984 notify = tcp_mtudisc_notify; 2985 break; 2986 case ECONNREFUSED: 2987 if (V_icmp_may_rst) 2988 notify = tcp_drop_syn_sent; 2989 else 2990 notify = tcp_notify; 2991 break; 2992 case EHOSTUNREACH: 2993 /* 2994 * There are only four ICMPs that may reset connection: 2995 * - administratively prohibited 2996 * - port unreachable 2997 * - time exceeded in transit 2998 * - unknown next header 2999 */ 3000 if (V_icmp_may_rst && 3001 ((icmp6->icmp6_type == ICMP6_DST_UNREACH && 3002 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN || 3003 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) || 3004 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED && 3005 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) || 3006 (icmp6->icmp6_type == ICMP6_PARAM_PROB && 3007 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER))) 3008 notify = tcp_drop_syn_sent; 3009 else 3010 notify = tcp_notify; 3011 break; 3012 default: 3013 notify = tcp_notify; 3014 } 3015 3016 /* Check if we can safely get the ports from the tcp hdr */ 3017 if (m == NULL || 3018 (m->m_pkthdr.len < 3019 (int32_t) (off + sizeof(struct tcp_ports)))) { 3020 return; 3021 } 3022 bzero(&t_ports, sizeof(struct tcp_ports)); 3023 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3024 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3025 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3026 off += sizeof(struct tcp_ports); 3027 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3028 goto out; 3029 } 3030 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3031 if (inp != NULL) { 3032 tp = intotcpcb(inp); 3033 #ifdef TCP_OFFLOAD 3034 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 3035 /* MTU discovery for offloaded connections. */ 3036 mtu = tcp6_next_pmtu(icmp6); 3037 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3038 goto out; 3039 } 3040 #endif 3041 if (tp->t_port != port) 3042 goto out; 3043 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3044 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3045 if (errno == EMSGSIZE) { 3046 /* 3047 * MTU discovery: 3048 * If we got a needfrag set the MTU 3049 * in the route to the suggested new 3050 * value (if given) and then notify. 3051 */ 3052 mtu = tcp6_next_pmtu(icmp6); 3053 3054 bzero(&inc, sizeof(inc)); 3055 inc.inc_fibnum = M_GETFIB(m); 3056 inc.inc_flags |= INC_ISIPV6; 3057 inc.inc6_faddr = *dst; 3058 if (in6_setscope(&inc.inc6_faddr, 3059 m->m_pkthdr.rcvif, NULL)) 3060 goto out; 3061 /* 3062 * Only process the offered MTU if it 3063 * is smaller than the current one. 3064 */ 3065 if (mtu < tp->t_maxseg + 3066 sizeof (struct tcphdr) + 3067 sizeof (struct ip6_hdr)) { 3068 tcp_hc_updatemtu(&inc, mtu); 3069 tcp_mtudisc(inp, mtu); 3070 ICMP6STAT_INC(icp6s_pmtuchg); 3071 } 3072 } else 3073 inp = (*notify)(inp, errno); 3074 } 3075 } else { 3076 bzero(&inc, sizeof(inc)); 3077 inc.inc_fibnum = M_GETFIB(m); 3078 inc.inc_flags |= INC_ISIPV6; 3079 inc.inc_fport = t_ports.th_dport; 3080 inc.inc_lport = t_ports.th_sport; 3081 inc.inc6_faddr = *dst; 3082 inc.inc6_laddr = ip6->ip6_src; 3083 syncache_unreach(&inc, icmp_tcp_seq, port); 3084 } 3085 out: 3086 if (inp != NULL) 3087 INP_WUNLOCK(inp); 3088 } 3089 3090 static void 3091 tcp6_ctlinput(struct ip6ctlparam *ctl) 3092 { 3093 tcp6_ctlinput_with_port(ctl, htons(0)); 3094 } 3095 3096 static void 3097 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param) 3098 { 3099 struct ip6ctlparam *ip6cp = param.ip6cp; 3100 struct mbuf *m; 3101 struct udphdr *udp; 3102 uint16_t port; 3103 3104 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3105 if (m == NULL) { 3106 return; 3107 } 3108 udp = mtod(m, struct udphdr *); 3109 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3110 return; 3111 } 3112 port = udp->uh_dport; 3113 m_adj(m, sizeof(struct udphdr)); 3114 if ((m->m_flags & M_PKTHDR) == 0) { 3115 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3116 } 3117 /* Now call in to the normal handling code */ 3118 tcp6_ctlinput_with_port(ip6cp, port); 3119 } 3120 3121 #endif /* INET6 */ 3122 3123 static uint32_t 3124 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3125 { 3126 SIPHASH_CTX ctx; 3127 uint32_t hash[2]; 3128 3129 KASSERT(len >= SIPHASH_KEY_LENGTH, 3130 ("%s: keylen %u too short ", __func__, len)); 3131 SipHash24_Init(&ctx); 3132 SipHash_SetKey(&ctx, (uint8_t *)key); 3133 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3134 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3135 switch (inc->inc_flags & INC_ISIPV6) { 3136 #ifdef INET 3137 case 0: 3138 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3139 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3140 break; 3141 #endif 3142 #ifdef INET6 3143 case INC_ISIPV6: 3144 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3145 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3146 break; 3147 #endif 3148 } 3149 SipHash_Final((uint8_t *)hash, &ctx); 3150 3151 return (hash[0] ^ hash[1]); 3152 } 3153 3154 uint32_t 3155 tcp_new_ts_offset(struct in_conninfo *inc) 3156 { 3157 struct in_conninfo inc_store, *local_inc; 3158 3159 if (!V_tcp_ts_offset_per_conn) { 3160 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3161 inc_store.inc_lport = 0; 3162 inc_store.inc_fport = 0; 3163 local_inc = &inc_store; 3164 } else { 3165 local_inc = inc; 3166 } 3167 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3168 sizeof(V_ts_offset_secret))); 3169 } 3170 3171 /* 3172 * Following is where TCP initial sequence number generation occurs. 3173 * 3174 * There are two places where we must use initial sequence numbers: 3175 * 1. In SYN-ACK packets. 3176 * 2. In SYN packets. 3177 * 3178 * All ISNs for SYN-ACK packets are generated by the syncache. See 3179 * tcp_syncache.c for details. 3180 * 3181 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3182 * depends on this property. In addition, these ISNs should be 3183 * unguessable so as to prevent connection hijacking. To satisfy 3184 * the requirements of this situation, the algorithm outlined in 3185 * RFC 1948 is used, with only small modifications. 3186 * 3187 * Implementation details: 3188 * 3189 * Time is based off the system timer, and is corrected so that it 3190 * increases by one megabyte per second. This allows for proper 3191 * recycling on high speed LANs while still leaving over an hour 3192 * before rollover. 3193 * 3194 * As reading the *exact* system time is too expensive to be done 3195 * whenever setting up a TCP connection, we increment the time 3196 * offset in two ways. First, a small random positive increment 3197 * is added to isn_offset for each connection that is set up. 3198 * Second, the function tcp_isn_tick fires once per clock tick 3199 * and increments isn_offset as necessary so that sequence numbers 3200 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3201 * random positive increments serve only to ensure that the same 3202 * exact sequence number is never sent out twice (as could otherwise 3203 * happen when a port is recycled in less than the system tick 3204 * interval.) 3205 * 3206 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3207 * between seeding of isn_secret. This is normally set to zero, 3208 * as reseeding should not be necessary. 3209 * 3210 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3211 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3212 * general, this means holding an exclusive (write) lock. 3213 */ 3214 3215 #define ISN_BYTES_PER_SECOND 1048576 3216 #define ISN_STATIC_INCREMENT 4096 3217 #define ISN_RANDOM_INCREMENT (4096 - 1) 3218 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3219 3220 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3221 VNET_DEFINE_STATIC(int, isn_last); 3222 VNET_DEFINE_STATIC(int, isn_last_reseed); 3223 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3224 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3225 3226 #define V_isn_secret VNET(isn_secret) 3227 #define V_isn_last VNET(isn_last) 3228 #define V_isn_last_reseed VNET(isn_last_reseed) 3229 #define V_isn_offset VNET(isn_offset) 3230 #define V_isn_offset_old VNET(isn_offset_old) 3231 3232 tcp_seq 3233 tcp_new_isn(struct in_conninfo *inc) 3234 { 3235 tcp_seq new_isn; 3236 u_int32_t projected_offset; 3237 3238 ISN_LOCK(); 3239 /* Seed if this is the first use, reseed if requested. */ 3240 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3241 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3242 < (u_int)ticks))) { 3243 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3244 V_isn_last_reseed = ticks; 3245 } 3246 3247 /* Compute the hash and return the ISN. */ 3248 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3249 sizeof(V_isn_secret)); 3250 V_isn_offset += ISN_STATIC_INCREMENT + 3251 (arc4random() & ISN_RANDOM_INCREMENT); 3252 if (ticks != V_isn_last) { 3253 projected_offset = V_isn_offset_old + 3254 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3255 if (SEQ_GT(projected_offset, V_isn_offset)) 3256 V_isn_offset = projected_offset; 3257 V_isn_offset_old = V_isn_offset; 3258 V_isn_last = ticks; 3259 } 3260 new_isn += V_isn_offset; 3261 ISN_UNLOCK(); 3262 return (new_isn); 3263 } 3264 3265 /* 3266 * When a specific ICMP unreachable message is received and the 3267 * connection state is SYN-SENT, drop the connection. This behavior 3268 * is controlled by the icmp_may_rst sysctl. 3269 */ 3270 static struct inpcb * 3271 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3272 { 3273 struct tcpcb *tp; 3274 3275 NET_EPOCH_ASSERT(); 3276 INP_WLOCK_ASSERT(inp); 3277 3278 tp = intotcpcb(inp); 3279 if (tp->t_state != TCPS_SYN_SENT) 3280 return (inp); 3281 3282 if (IS_FASTOPEN(tp->t_flags)) 3283 tcp_fastopen_disable_path(tp); 3284 3285 tp = tcp_drop(tp, errno); 3286 if (tp != NULL) 3287 return (inp); 3288 else 3289 return (NULL); 3290 } 3291 3292 /* 3293 * When `need fragmentation' ICMP is received, update our idea of the MSS 3294 * based on the new value. Also nudge TCP to send something, since we 3295 * know the packet we just sent was dropped. 3296 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3297 */ 3298 static struct inpcb * 3299 tcp_mtudisc_notify(struct inpcb *inp, int error) 3300 { 3301 3302 return (tcp_mtudisc(inp, -1)); 3303 } 3304 3305 static struct inpcb * 3306 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3307 { 3308 struct tcpcb *tp; 3309 struct socket *so; 3310 3311 INP_WLOCK_ASSERT(inp); 3312 3313 tp = intotcpcb(inp); 3314 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3315 3316 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3317 3318 so = inp->inp_socket; 3319 SOCKBUF_LOCK(&so->so_snd); 3320 /* If the mss is larger than the socket buffer, decrease the mss. */ 3321 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3322 tp->t_maxseg = so->so_snd.sb_hiwat; 3323 SOCKBUF_UNLOCK(&so->so_snd); 3324 3325 TCPSTAT_INC(tcps_mturesent); 3326 tp->t_rtttime = 0; 3327 tp->snd_nxt = tp->snd_una; 3328 tcp_free_sackholes(tp); 3329 tp->snd_recover = tp->snd_max; 3330 if (tp->t_flags & TF_SACK_PERMIT) 3331 EXIT_FASTRECOVERY(tp->t_flags); 3332 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3333 /* 3334 * Conceptually the snd_nxt setting 3335 * and freeing sack holes should 3336 * be done by the default stacks 3337 * own tfb_tcp_mtu_chg(). 3338 */ 3339 tp->t_fb->tfb_tcp_mtu_chg(tp); 3340 } 3341 if (tcp_output(tp) < 0) 3342 return (NULL); 3343 else 3344 return (inp); 3345 } 3346 3347 #ifdef INET 3348 /* 3349 * Look-up the routing entry to the peer of this inpcb. If no route 3350 * is found and it cannot be allocated, then return 0. This routine 3351 * is called by TCP routines that access the rmx structure and by 3352 * tcp_mss_update to get the peer/interface MTU. 3353 */ 3354 uint32_t 3355 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3356 { 3357 struct nhop_object *nh; 3358 struct ifnet *ifp; 3359 uint32_t maxmtu = 0; 3360 3361 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3362 3363 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3364 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3365 if (nh == NULL) 3366 return (0); 3367 3368 ifp = nh->nh_ifp; 3369 maxmtu = nh->nh_mtu; 3370 3371 /* Report additional interface capabilities. */ 3372 if (cap != NULL) { 3373 if (ifp->if_capenable & IFCAP_TSO4 && 3374 ifp->if_hwassist & CSUM_TSO) { 3375 cap->ifcap |= CSUM_TSO; 3376 cap->tsomax = ifp->if_hw_tsomax; 3377 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3378 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3379 } 3380 } 3381 } 3382 return (maxmtu); 3383 } 3384 #endif /* INET */ 3385 3386 #ifdef INET6 3387 uint32_t 3388 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3389 { 3390 struct nhop_object *nh; 3391 struct in6_addr dst6; 3392 uint32_t scopeid; 3393 struct ifnet *ifp; 3394 uint32_t maxmtu = 0; 3395 3396 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3397 3398 if (inc->inc_flags & INC_IPV6MINMTU) 3399 return (IPV6_MMTU); 3400 3401 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3402 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3403 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3404 if (nh == NULL) 3405 return (0); 3406 3407 ifp = nh->nh_ifp; 3408 maxmtu = nh->nh_mtu; 3409 3410 /* Report additional interface capabilities. */ 3411 if (cap != NULL) { 3412 if (ifp->if_capenable & IFCAP_TSO6 && 3413 ifp->if_hwassist & CSUM_TSO) { 3414 cap->ifcap |= CSUM_TSO; 3415 cap->tsomax = ifp->if_hw_tsomax; 3416 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3417 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3418 } 3419 } 3420 } 3421 3422 return (maxmtu); 3423 } 3424 3425 /* 3426 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3427 * 3428 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3429 * The right place to do that is ip6_setpktopt() that has just been 3430 * executed. By the way it just filled ip6po_minmtu for us. 3431 */ 3432 void 3433 tcp6_use_min_mtu(struct tcpcb *tp) 3434 { 3435 struct inpcb *inp = tptoinpcb(tp); 3436 3437 INP_WLOCK_ASSERT(inp); 3438 /* 3439 * In case of the IPV6_USE_MIN_MTU socket 3440 * option, the INC_IPV6MINMTU flag to announce 3441 * a corresponding MSS during the initial 3442 * handshake. If the TCP connection is not in 3443 * the front states, just reduce the MSS being 3444 * used. This avoids the sending of TCP 3445 * segments which will be fragmented at the 3446 * IPv6 layer. 3447 */ 3448 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3449 if ((tp->t_state >= TCPS_SYN_SENT) && 3450 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3451 struct ip6_pktopts *opt; 3452 3453 opt = inp->in6p_outputopts; 3454 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3455 tp->t_maxseg > TCP6_MSS) 3456 tp->t_maxseg = TCP6_MSS; 3457 } 3458 } 3459 #endif /* INET6 */ 3460 3461 /* 3462 * Calculate effective SMSS per RFC5681 definition for a given TCP 3463 * connection at its current state, taking into account SACK and etc. 3464 */ 3465 u_int 3466 tcp_maxseg(const struct tcpcb *tp) 3467 { 3468 u_int optlen; 3469 3470 if (tp->t_flags & TF_NOOPT) 3471 return (tp->t_maxseg); 3472 3473 /* 3474 * Here we have a simplified code from tcp_addoptions(), 3475 * without a proper loop, and having most of paddings hardcoded. 3476 * We might make mistakes with padding here in some edge cases, 3477 * but this is harmless, since result of tcp_maxseg() is used 3478 * only in cwnd and ssthresh estimations. 3479 */ 3480 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3481 if (tp->t_flags & TF_RCVD_TSTMP) 3482 optlen = TCPOLEN_TSTAMP_APPA; 3483 else 3484 optlen = 0; 3485 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3486 if (tp->t_flags & TF_SIGNATURE) 3487 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3488 #endif 3489 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3490 optlen += TCPOLEN_SACKHDR; 3491 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3492 optlen = PADTCPOLEN(optlen); 3493 } 3494 } else { 3495 if (tp->t_flags & TF_REQ_TSTMP) 3496 optlen = TCPOLEN_TSTAMP_APPA; 3497 else 3498 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3499 if (tp->t_flags & TF_REQ_SCALE) 3500 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3501 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3502 if (tp->t_flags & TF_SIGNATURE) 3503 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3504 #endif 3505 if (tp->t_flags & TF_SACK_PERMIT) 3506 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3507 } 3508 #undef PAD 3509 optlen = min(optlen, TCP_MAXOLEN); 3510 return (tp->t_maxseg - optlen); 3511 } 3512 3513 3514 u_int 3515 tcp_fixed_maxseg(const struct tcpcb *tp) 3516 { 3517 int optlen; 3518 3519 if (tp->t_flags & TF_NOOPT) 3520 return (tp->t_maxseg); 3521 3522 /* 3523 * Here we have a simplified code from tcp_addoptions(), 3524 * without a proper loop, and having most of paddings hardcoded. 3525 * We only consider fixed options that we would send every 3526 * time I.e. SACK is not considered. This is important 3527 * for cc modules to figure out what the modulo of the 3528 * cwnd should be. 3529 */ 3530 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3531 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3532 if (tp->t_flags & TF_RCVD_TSTMP) 3533 optlen = TCPOLEN_TSTAMP_APPA; 3534 else 3535 optlen = 0; 3536 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3537 if (tp->t_flags & TF_SIGNATURE) 3538 optlen += PAD(TCPOLEN_SIGNATURE); 3539 #endif 3540 } else { 3541 if (tp->t_flags & TF_REQ_TSTMP) 3542 optlen = TCPOLEN_TSTAMP_APPA; 3543 else 3544 optlen = PAD(TCPOLEN_MAXSEG); 3545 if (tp->t_flags & TF_REQ_SCALE) 3546 optlen += PAD(TCPOLEN_WINDOW); 3547 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3548 if (tp->t_flags & TF_SIGNATURE) 3549 optlen += PAD(TCPOLEN_SIGNATURE); 3550 #endif 3551 if (tp->t_flags & TF_SACK_PERMIT) 3552 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3553 } 3554 #undef PAD 3555 optlen = min(optlen, TCP_MAXOLEN); 3556 return (tp->t_maxseg - optlen); 3557 } 3558 3559 3560 3561 static int 3562 sysctl_drop(SYSCTL_HANDLER_ARGS) 3563 { 3564 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3565 struct sockaddr_storage addrs[2]; 3566 struct inpcb *inp; 3567 struct tcpcb *tp; 3568 #ifdef INET 3569 struct sockaddr_in *fin = NULL, *lin = NULL; 3570 #endif 3571 struct epoch_tracker et; 3572 #ifdef INET6 3573 struct sockaddr_in6 *fin6, *lin6; 3574 #endif 3575 int error; 3576 3577 inp = NULL; 3578 #ifdef INET6 3579 fin6 = lin6 = NULL; 3580 #endif 3581 error = 0; 3582 3583 if (req->oldptr != NULL || req->oldlen != 0) 3584 return (EINVAL); 3585 if (req->newptr == NULL) 3586 return (EPERM); 3587 if (req->newlen < sizeof(addrs)) 3588 return (ENOMEM); 3589 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3590 if (error) 3591 return (error); 3592 3593 switch (addrs[0].ss_family) { 3594 #ifdef INET6 3595 case AF_INET6: 3596 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3597 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3598 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3599 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3600 return (EINVAL); 3601 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3602 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3603 return (EINVAL); 3604 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3605 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3606 #ifdef INET 3607 fin = (struct sockaddr_in *)&addrs[0]; 3608 lin = (struct sockaddr_in *)&addrs[1]; 3609 #endif 3610 break; 3611 } 3612 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3613 if (error) 3614 return (error); 3615 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3616 if (error) 3617 return (error); 3618 break; 3619 #endif 3620 #ifdef INET 3621 case AF_INET: 3622 fin = (struct sockaddr_in *)&addrs[0]; 3623 lin = (struct sockaddr_in *)&addrs[1]; 3624 if (fin->sin_len != sizeof(struct sockaddr_in) || 3625 lin->sin_len != sizeof(struct sockaddr_in)) 3626 return (EINVAL); 3627 break; 3628 #endif 3629 default: 3630 return (EINVAL); 3631 } 3632 NET_EPOCH_ENTER(et); 3633 switch (addrs[0].ss_family) { 3634 #ifdef INET6 3635 case AF_INET6: 3636 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3637 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3638 INPLOOKUP_WLOCKPCB, NULL); 3639 break; 3640 #endif 3641 #ifdef INET 3642 case AF_INET: 3643 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3644 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3645 break; 3646 #endif 3647 } 3648 if (inp != NULL) { 3649 if (!SOLISTENING(inp->inp_socket)) { 3650 tp = intotcpcb(inp); 3651 tp = tcp_drop(tp, ECONNABORTED); 3652 if (tp != NULL) 3653 INP_WUNLOCK(inp); 3654 } else 3655 INP_WUNLOCK(inp); 3656 } else 3657 error = ESRCH; 3658 NET_EPOCH_EXIT(et); 3659 return (error); 3660 } 3661 3662 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3663 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3664 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3665 "Drop TCP connection"); 3666 3667 static int 3668 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3669 { 3670 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3671 &tcp_ctloutput_set)); 3672 } 3673 3674 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3675 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3676 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3677 "Set socket option for TCP endpoint"); 3678 3679 #ifdef KERN_TLS 3680 static int 3681 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3682 { 3683 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3684 struct sockaddr_storage addrs[2]; 3685 struct inpcb *inp; 3686 #ifdef INET 3687 struct sockaddr_in *fin = NULL, *lin = NULL; 3688 #endif 3689 struct epoch_tracker et; 3690 #ifdef INET6 3691 struct sockaddr_in6 *fin6, *lin6; 3692 #endif 3693 int error; 3694 3695 inp = NULL; 3696 #ifdef INET6 3697 fin6 = lin6 = NULL; 3698 #endif 3699 error = 0; 3700 3701 if (req->oldptr != NULL || req->oldlen != 0) 3702 return (EINVAL); 3703 if (req->newptr == NULL) 3704 return (EPERM); 3705 if (req->newlen < sizeof(addrs)) 3706 return (ENOMEM); 3707 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3708 if (error) 3709 return (error); 3710 3711 switch (addrs[0].ss_family) { 3712 #ifdef INET6 3713 case AF_INET6: 3714 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3715 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3716 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3717 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3718 return (EINVAL); 3719 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3720 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3721 return (EINVAL); 3722 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3723 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3724 #ifdef INET 3725 fin = (struct sockaddr_in *)&addrs[0]; 3726 lin = (struct sockaddr_in *)&addrs[1]; 3727 #endif 3728 break; 3729 } 3730 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3731 if (error) 3732 return (error); 3733 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3734 if (error) 3735 return (error); 3736 break; 3737 #endif 3738 #ifdef INET 3739 case AF_INET: 3740 fin = (struct sockaddr_in *)&addrs[0]; 3741 lin = (struct sockaddr_in *)&addrs[1]; 3742 if (fin->sin_len != sizeof(struct sockaddr_in) || 3743 lin->sin_len != sizeof(struct sockaddr_in)) 3744 return (EINVAL); 3745 break; 3746 #endif 3747 default: 3748 return (EINVAL); 3749 } 3750 NET_EPOCH_ENTER(et); 3751 switch (addrs[0].ss_family) { 3752 #ifdef INET6 3753 case AF_INET6: 3754 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3755 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3756 INPLOOKUP_WLOCKPCB, NULL); 3757 break; 3758 #endif 3759 #ifdef INET 3760 case AF_INET: 3761 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3762 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3763 break; 3764 #endif 3765 } 3766 NET_EPOCH_EXIT(et); 3767 if (inp != NULL) { 3768 struct socket *so; 3769 3770 so = inp->inp_socket; 3771 soref(so); 3772 error = ktls_set_tx_mode(so, 3773 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3774 INP_WUNLOCK(inp); 3775 sorele(so); 3776 } else 3777 error = ESRCH; 3778 return (error); 3779 } 3780 3781 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3782 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3783 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3784 "Switch TCP connection to SW TLS"); 3785 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3786 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3787 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3788 "Switch TCP connection to ifnet TLS"); 3789 #endif 3790 3791 /* 3792 * Generate a standardized TCP log line for use throughout the 3793 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3794 * allow use in the interrupt context. 3795 * 3796 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3797 * NB: The function may return NULL if memory allocation failed. 3798 * 3799 * Due to header inclusion and ordering limitations the struct ip 3800 * and ip6_hdr pointers have to be passed as void pointers. 3801 */ 3802 char * 3803 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3804 const void *ip6hdr) 3805 { 3806 3807 /* Is logging enabled? */ 3808 if (V_tcp_log_in_vain == 0) 3809 return (NULL); 3810 3811 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3812 } 3813 3814 char * 3815 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3816 const void *ip6hdr) 3817 { 3818 3819 /* Is logging enabled? */ 3820 if (tcp_log_debug == 0) 3821 return (NULL); 3822 3823 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3824 } 3825 3826 static char * 3827 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3828 const void *ip6hdr) 3829 { 3830 char *s, *sp; 3831 size_t size; 3832 #ifdef INET 3833 const struct ip *ip = (const struct ip *)ip4hdr; 3834 #endif 3835 #ifdef INET6 3836 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3837 #endif /* INET6 */ 3838 3839 /* 3840 * The log line looks like this: 3841 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3842 */ 3843 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3844 sizeof(PRINT_TH_FLAGS) + 1 + 3845 #ifdef INET6 3846 2 * INET6_ADDRSTRLEN; 3847 #else 3848 2 * INET_ADDRSTRLEN; 3849 #endif /* INET6 */ 3850 3851 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3852 if (s == NULL) 3853 return (NULL); 3854 3855 strcat(s, "TCP: ["); 3856 sp = s + strlen(s); 3857 3858 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3859 inet_ntoa_r(inc->inc_faddr, sp); 3860 sp = s + strlen(s); 3861 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3862 sp = s + strlen(s); 3863 inet_ntoa_r(inc->inc_laddr, sp); 3864 sp = s + strlen(s); 3865 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3866 #ifdef INET6 3867 } else if (inc) { 3868 ip6_sprintf(sp, &inc->inc6_faddr); 3869 sp = s + strlen(s); 3870 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3871 sp = s + strlen(s); 3872 ip6_sprintf(sp, &inc->inc6_laddr); 3873 sp = s + strlen(s); 3874 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3875 } else if (ip6 && th) { 3876 ip6_sprintf(sp, &ip6->ip6_src); 3877 sp = s + strlen(s); 3878 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3879 sp = s + strlen(s); 3880 ip6_sprintf(sp, &ip6->ip6_dst); 3881 sp = s + strlen(s); 3882 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3883 #endif /* INET6 */ 3884 #ifdef INET 3885 } else if (ip && th) { 3886 inet_ntoa_r(ip->ip_src, sp); 3887 sp = s + strlen(s); 3888 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3889 sp = s + strlen(s); 3890 inet_ntoa_r(ip->ip_dst, sp); 3891 sp = s + strlen(s); 3892 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3893 #endif /* INET */ 3894 } else { 3895 free(s, M_TCPLOG); 3896 return (NULL); 3897 } 3898 sp = s + strlen(s); 3899 if (th) 3900 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3901 if (*(s + size - 1) != '\0') 3902 panic("%s: string too long", __func__); 3903 return (s); 3904 } 3905 3906 /* 3907 * A subroutine which makes it easy to track TCP state changes with DTrace. 3908 * This function shouldn't be called for t_state initializations that don't 3909 * correspond to actual TCP state transitions. 3910 */ 3911 void 3912 tcp_state_change(struct tcpcb *tp, int newstate) 3913 { 3914 #if defined(KDTRACE_HOOKS) 3915 int pstate = tp->t_state; 3916 #endif 3917 3918 TCPSTATES_DEC(tp->t_state); 3919 TCPSTATES_INC(newstate); 3920 tp->t_state = newstate; 3921 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3922 } 3923 3924 /* 3925 * Create an external-format (``xtcpcb'') structure using the information in 3926 * the kernel-format tcpcb structure pointed to by tp. This is done to 3927 * reduce the spew of irrelevant information over this interface, to isolate 3928 * user code from changes in the kernel structure, and potentially to provide 3929 * information-hiding if we decide that some of this information should be 3930 * hidden from users. 3931 */ 3932 void 3933 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3934 { 3935 struct tcpcb *tp = intotcpcb(inp); 3936 sbintime_t now; 3937 3938 bzero(xt, sizeof(*xt)); 3939 xt->t_state = tp->t_state; 3940 xt->t_logstate = tcp_get_bblog_state(tp); 3941 xt->t_flags = tp->t_flags; 3942 xt->t_sndzerowin = tp->t_sndzerowin; 3943 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3944 xt->t_rcvoopack = tp->t_rcvoopack; 3945 xt->t_rcv_wnd = tp->rcv_wnd; 3946 xt->t_snd_wnd = tp->snd_wnd; 3947 xt->t_snd_cwnd = tp->snd_cwnd; 3948 xt->t_snd_ssthresh = tp->snd_ssthresh; 3949 xt->t_dsack_bytes = tp->t_dsack_bytes; 3950 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 3951 xt->t_dsack_pack = tp->t_dsack_pack; 3952 xt->t_maxseg = tp->t_maxseg; 3953 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3954 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3955 3956 now = getsbinuptime(); 3957 #define COPYTIMER(which,where) do { \ 3958 if (tp->t_timers[which] != SBT_MAX) \ 3959 xt->where = (tp->t_timers[which] - now) / SBT_1MS; \ 3960 else \ 3961 xt->where = 0; \ 3962 } while (0) 3963 COPYTIMER(TT_DELACK, tt_delack); 3964 COPYTIMER(TT_REXMT, tt_rexmt); 3965 COPYTIMER(TT_PERSIST, tt_persist); 3966 COPYTIMER(TT_KEEP, tt_keep); 3967 COPYTIMER(TT_2MSL, tt_2msl); 3968 #undef COPYTIMER 3969 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3970 3971 xt->xt_encaps_port = tp->t_port; 3972 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3973 TCP_FUNCTION_NAME_LEN_MAX); 3974 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX); 3975 #ifdef TCP_BLACKBOX 3976 (void)tcp_log_get_id(tp, xt->xt_logid); 3977 #endif 3978 3979 xt->xt_len = sizeof(struct xtcpcb); 3980 in_pcbtoxinpcb(inp, &xt->xt_inp); 3981 /* 3982 * TCP doesn't use inp_ppcb pointer, we embed inpcb into tcpcb. 3983 * Fixup the pointer that in_pcbtoxinpcb() has set. When printing 3984 * TCP netstat(1) used to use this pointer, so this fixup needs to 3985 * stay for stable/14. 3986 */ 3987 xt->xt_inp.inp_ppcb = (uintptr_t)tp; 3988 } 3989 3990 void 3991 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 3992 { 3993 uint32_t bit, i; 3994 3995 if ((tp == NULL) || 3996 (status > TCP_EI_STATUS_MAX_VALUE) || 3997 (status == 0)) { 3998 /* Invalid */ 3999 return; 4000 } 4001 if (status > (sizeof(uint32_t) * 8)) { 4002 /* Should this be a KASSERT? */ 4003 return; 4004 } 4005 bit = 1U << (status - 1); 4006 if (bit & tp->t_end_info_status) { 4007 /* already logged */ 4008 return; 4009 } 4010 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4011 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4012 tp->t_end_info_bytes[i] = status; 4013 tp->t_end_info_status |= bit; 4014 break; 4015 } 4016 } 4017 } 4018 4019 int 4020 tcp_can_enable_pacing(void) 4021 { 4022 4023 if ((tcp_pacing_limit == -1) || 4024 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4025 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4026 shadow_num_connections = number_of_tcp_connections_pacing; 4027 return (1); 4028 } else { 4029 counter_u64_add(tcp_pacing_failures, 1); 4030 return (0); 4031 } 4032 } 4033 4034 static uint8_t tcp_pacing_warning = 0; 4035 4036 void 4037 tcp_decrement_paced_conn(void) 4038 { 4039 uint32_t ret; 4040 4041 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4042 shadow_num_connections = number_of_tcp_connections_pacing; 4043 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4044 if (ret == 0) { 4045 if (tcp_pacing_limit != -1) { 4046 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4047 tcp_pacing_limit = 0; 4048 } else if (tcp_pacing_warning == 0) { 4049 printf("Warning pacing count is invalid, invalid decrement\n"); 4050 tcp_pacing_warning = 1; 4051 } 4052 } 4053 } 4054 4055 static void 4056 tcp_default_switch_failed(struct tcpcb *tp) 4057 { 4058 /* 4059 * If a switch fails we only need to 4060 * care about two things: 4061 * a) The t_flags2 4062 * and 4063 * b) The timer granularity. 4064 * Timeouts, at least for now, don't use the 4065 * old callout system in the other stacks so 4066 * those are hopefully safe. 4067 */ 4068 tcp_lro_features_off(tp); 4069 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS); 4070 } 4071 4072 #ifdef TCP_ACCOUNTING 4073 int 4074 tcp_do_ack_accounting(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t tiwin, int mss) 4075 { 4076 if (SEQ_LT(th->th_ack, tp->snd_una)) { 4077 /* Do we have a SACK? */ 4078 if (to->to_flags & TOF_SACK) { 4079 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4080 tp->tcp_cnt_counters[ACK_SACK]++; 4081 } 4082 return (ACK_SACK); 4083 } else { 4084 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4085 tp->tcp_cnt_counters[ACK_BEHIND]++; 4086 } 4087 return (ACK_BEHIND); 4088 } 4089 } else if (th->th_ack == tp->snd_una) { 4090 /* Do we have a SACK? */ 4091 if (to->to_flags & TOF_SACK) { 4092 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4093 tp->tcp_cnt_counters[ACK_SACK]++; 4094 } 4095 return (ACK_SACK); 4096 } else if (tiwin != tp->snd_wnd) { 4097 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4098 tp->tcp_cnt_counters[ACK_RWND]++; 4099 } 4100 return (ACK_RWND); 4101 } else { 4102 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4103 tp->tcp_cnt_counters[ACK_DUPACK]++; 4104 } 4105 return (ACK_DUPACK); 4106 } 4107 } else { 4108 if (!SEQ_GT(th->th_ack, tp->snd_max)) { 4109 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4110 tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((th->th_ack - tp->snd_una) + mss - 1)/mss); 4111 } 4112 } 4113 if (to->to_flags & TOF_SACK) { 4114 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4115 tp->tcp_cnt_counters[ACK_CUMACK_SACK]++; 4116 } 4117 return (ACK_CUMACK_SACK); 4118 } else { 4119 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4120 tp->tcp_cnt_counters[ACK_CUMACK]++; 4121 } 4122 return (ACK_CUMACK); 4123 } 4124 } 4125 } 4126 #endif 4127 4128 void 4129 tcp_change_time_units(struct tcpcb *tp, int granularity) 4130 { 4131 if (tp->t_tmr_granularity == granularity) { 4132 /* We are there */ 4133 return; 4134 } 4135 if (granularity == TCP_TMR_GRANULARITY_USEC) { 4136 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS), 4137 ("Granularity is not TICKS its %u in tp:%p", 4138 tp->t_tmr_granularity, tp)); 4139 tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow); 4140 if (tp->t_srtt > 1) { 4141 uint32_t val, frac; 4142 4143 val = tp->t_srtt >> TCP_RTT_SHIFT; 4144 frac = tp->t_srtt & 0x1f; 4145 tp->t_srtt = TICKS_2_USEC(val); 4146 /* 4147 * frac is the fractional part of the srtt (if any) 4148 * but its in ticks and every bit represents 4149 * 1/32nd of a hz. 4150 */ 4151 if (frac) { 4152 if (hz == 1000) { 4153 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE); 4154 } else { 4155 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE)); 4156 } 4157 tp->t_srtt += frac; 4158 } 4159 } 4160 if (tp->t_rttvar) { 4161 uint32_t val, frac; 4162 4163 val = tp->t_rttvar >> TCP_RTTVAR_SHIFT; 4164 frac = tp->t_rttvar & 0x1f; 4165 tp->t_rttvar = TICKS_2_USEC(val); 4166 /* 4167 * frac is the fractional part of the srtt (if any) 4168 * but its in ticks and every bit represents 4169 * 1/32nd of a hz. 4170 */ 4171 if (frac) { 4172 if (hz == 1000) { 4173 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE); 4174 } else { 4175 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE)); 4176 } 4177 tp->t_rttvar += frac; 4178 } 4179 } 4180 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_USEC; 4181 } else if (granularity == TCP_TMR_GRANULARITY_TICKS) { 4182 /* Convert back to ticks, with */ 4183 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_USEC), 4184 ("Granularity is not USEC its %u in tp:%p", 4185 tp->t_tmr_granularity, tp)); 4186 if (tp->t_srtt > 1) { 4187 uint32_t val, frac; 4188 4189 val = USEC_2_TICKS(tp->t_srtt); 4190 frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz); 4191 tp->t_srtt = val << TCP_RTT_SHIFT; 4192 /* 4193 * frac is the fractional part here is left 4194 * over from converting to hz and shifting. 4195 * We need to convert this to the 5 bit 4196 * remainder. 4197 */ 4198 if (frac) { 4199 if (hz == 1000) { 4200 frac = (((uint64_t)frac * (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC); 4201 } else { 4202 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC); 4203 } 4204 tp->t_srtt += frac; 4205 } 4206 } 4207 if (tp->t_rttvar) { 4208 uint32_t val, frac; 4209 4210 val = USEC_2_TICKS(tp->t_rttvar); 4211 frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz); 4212 tp->t_rttvar = val << TCP_RTTVAR_SHIFT; 4213 /* 4214 * frac is the fractional part here is left 4215 * over from converting to hz and shifting. 4216 * We need to convert this to the 5 bit 4217 * remainder. 4218 */ 4219 if (frac) { 4220 if (hz == 1000) { 4221 frac = (((uint64_t)frac * (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC); 4222 } else { 4223 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC); 4224 } 4225 tp->t_rttvar += frac; 4226 } 4227 } 4228 tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow); 4229 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS; 4230 } 4231 #ifdef INVARIANTS 4232 else { 4233 panic("Unknown granularity:%d tp:%p", 4234 granularity, tp); 4235 } 4236 #endif 4237 } 4238 4239 void 4240 tcp_handle_orphaned_packets(struct tcpcb *tp) 4241 { 4242 struct mbuf *save, *m, *prev; 4243 /* 4244 * Called when a stack switch is occuring from the fini() 4245 * of the old stack. We assue the init() as already been 4246 * run of the new stack and it has set the t_flags2 to 4247 * what it supports. This function will then deal with any 4248 * differences i.e. cleanup packets that maybe queued that 4249 * the newstack does not support. 4250 */ 4251 4252 if (tp->t_flags2 & TF2_MBUF_L_ACKS) 4253 return; 4254 if ((tp->t_flags2 & TF2_SUPPORTS_MBUFQ) == 0 && 4255 !STAILQ_EMPTY(&tp->t_inqueue)) { 4256 /* 4257 * It is unsafe to process the packets since a 4258 * reset may be lurking in them (its rare but it 4259 * can occur). If we were to find a RST, then we 4260 * would end up dropping the connection and the 4261 * INP lock, so when we return the caller (tcp_usrreq) 4262 * will blow up when it trys to unlock the inp. 4263 * This new stack does not do any fancy LRO features 4264 * so all we can do is toss the packets. 4265 */ 4266 m = STAILQ_FIRST(&tp->t_inqueue); 4267 STAILQ_INIT(&tp->t_inqueue); 4268 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, save) 4269 m_freem(m); 4270 } else { 4271 /* 4272 * Here we have a stack that does mbuf queuing but 4273 * does not support compressed ack's. We must 4274 * walk all the mbufs and discard any compressed acks. 4275 */ 4276 STAILQ_FOREACH_SAFE(m, &tp->t_inqueue, m_stailqpkt, save) { 4277 if (m->m_flags & M_ACKCMP) { 4278 if (m == STAILQ_FIRST(&tp->t_inqueue)) 4279 STAILQ_REMOVE_HEAD(&tp->t_inqueue, 4280 m_stailqpkt); 4281 else 4282 STAILQ_REMOVE_AFTER(&tp->t_inqueue, 4283 prev, m_stailqpkt); 4284 m_freem(m); 4285 } else 4286 prev = m; 4287 } 4288 } 4289 } 4290 4291 #ifdef TCP_REQUEST_TRK 4292 uint32_t 4293 tcp_estimate_tls_overhead(struct socket *so, uint64_t tls_usr_bytes) 4294 { 4295 #ifdef KERN_TLS 4296 struct ktls_session *tls; 4297 uint32_t rec_oh, records; 4298 4299 tls = so->so_snd.sb_tls_info; 4300 if (tls == NULL) 4301 return (0); 4302 4303 rec_oh = tls->params.tls_hlen + tls->params.tls_tlen; 4304 records = ((tls_usr_bytes + tls->params.max_frame_len - 1)/tls->params.max_frame_len); 4305 return (records * rec_oh); 4306 #else 4307 return (0); 4308 #endif 4309 } 4310 4311 extern uint32_t tcp_stale_entry_time; 4312 uint32_t tcp_stale_entry_time = 250000; 4313 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, usrlog_stale, CTLFLAG_RW, 4314 &tcp_stale_entry_time, 250000, "Time that a tcpreq entry without a sendfile ages out"); 4315 4316 void 4317 tcp_req_log_req_info(struct tcpcb *tp, struct tcp_sendfile_track *req, 4318 uint16_t slot, uint8_t val, uint64_t offset, uint64_t nbytes) 4319 { 4320 if (tcp_bblogging_on(tp)) { 4321 union tcp_log_stackspecific log; 4322 struct timeval tv; 4323 4324 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 4325 #ifdef TCPHPTS 4326 log.u_bbr.inhpts = tcp_in_hpts(tp); 4327 #endif 4328 log.u_bbr.flex8 = val; 4329 log.u_bbr.rttProp = req->timestamp; 4330 log.u_bbr.delRate = req->start; 4331 log.u_bbr.cur_del_rate = req->end; 4332 log.u_bbr.flex1 = req->start_seq; 4333 log.u_bbr.flex2 = req->end_seq; 4334 log.u_bbr.flex3 = req->flags; 4335 log.u_bbr.flex4 = ((req->localtime >> 32) & 0x00000000ffffffff); 4336 log.u_bbr.flex5 = (req->localtime & 0x00000000ffffffff); 4337 log.u_bbr.flex7 = slot; 4338 log.u_bbr.bw_inuse = offset; 4339 /* nbytes = flex6 | epoch */ 4340 log.u_bbr.flex6 = ((nbytes >> 32) & 0x00000000ffffffff); 4341 log.u_bbr.epoch = (nbytes & 0x00000000ffffffff); 4342 /* cspr = lt_epoch | pkts_out */ 4343 log.u_bbr.lt_epoch = ((req->cspr >> 32) & 0x00000000ffffffff); 4344 log.u_bbr.pkts_out |= (req->cspr & 0x00000000ffffffff); 4345 log.u_bbr.applimited = tp->t_tcpreq_closed; 4346 log.u_bbr.applimited <<= 8; 4347 log.u_bbr.applimited |= tp->t_tcpreq_open; 4348 log.u_bbr.applimited <<= 8; 4349 log.u_bbr.applimited |= tp->t_tcpreq_req; 4350 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 4351 TCP_LOG_EVENTP(tp, NULL, 4352 &tptosocket(tp)->so_rcv, 4353 &tptosocket(tp)->so_snd, 4354 TCP_LOG_REQ_T, 0, 4355 0, &log, false, &tv); 4356 } 4357 } 4358 4359 void 4360 tcp_req_free_a_slot(struct tcpcb *tp, struct tcp_sendfile_track *ent) 4361 { 4362 if (tp->t_tcpreq_req > 0) 4363 tp->t_tcpreq_req--; 4364 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) { 4365 if (tp->t_tcpreq_open > 0) 4366 tp->t_tcpreq_open--; 4367 } else { 4368 if (tp->t_tcpreq_closed > 0) 4369 tp->t_tcpreq_closed--; 4370 } 4371 ent->flags = TCP_TRK_TRACK_FLG_EMPTY; 4372 } 4373 4374 static void 4375 tcp_req_check_for_stale_entries(struct tcpcb *tp, uint64_t ts, int rm_oldest) 4376 { 4377 struct tcp_sendfile_track *ent; 4378 uint64_t time_delta, oldest_delta; 4379 int i, oldest, oldest_set = 0, cnt_rm = 0; 4380 4381 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4382 ent = &tp->t_tcpreq_info[i]; 4383 if (ent->flags != TCP_TRK_TRACK_FLG_USED) { 4384 /* 4385 * We only care about closed end ranges 4386 * that are allocated and have no sendfile 4387 * ever touching them. They would be in 4388 * state USED. 4389 */ 4390 continue; 4391 } 4392 if (ts >= ent->localtime) 4393 time_delta = ts - ent->localtime; 4394 else 4395 time_delta = 0; 4396 if (time_delta && 4397 ((oldest_delta < time_delta) || (oldest_set == 0))) { 4398 oldest_set = 1; 4399 oldest = i; 4400 oldest_delta = time_delta; 4401 } 4402 if (tcp_stale_entry_time && (time_delta >= tcp_stale_entry_time)) { 4403 /* 4404 * No sendfile in a our time-limit 4405 * time to purge it. 4406 */ 4407 cnt_rm++; 4408 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE, 4409 time_delta, 0); 4410 tcp_req_free_a_slot(tp, ent); 4411 } 4412 } 4413 if ((cnt_rm == 0) && rm_oldest && oldest_set) { 4414 ent = &tp->t_tcpreq_info[oldest]; 4415 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE, 4416 oldest_delta, 1); 4417 tcp_req_free_a_slot(tp, ent); 4418 } 4419 } 4420 4421 int 4422 tcp_req_check_for_comp(struct tcpcb *tp, tcp_seq ack_point) 4423 { 4424 int i, ret=0; 4425 struct tcp_sendfile_track *ent; 4426 4427 /* Clean up any old closed end requests that are now completed */ 4428 if (tp->t_tcpreq_req == 0) 4429 return(0); 4430 if (tp->t_tcpreq_closed == 0) 4431 return(0); 4432 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4433 ent = &tp->t_tcpreq_info[i]; 4434 /* Skip empty ones */ 4435 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4436 continue; 4437 /* Skip open ones */ 4438 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) 4439 continue; 4440 if (SEQ_GEQ(ack_point, ent->end_seq)) { 4441 /* We are past it -- free it */ 4442 tcp_req_log_req_info(tp, ent, 4443 i, TCP_TRK_REQ_LOG_FREED, 0, 0); 4444 tcp_req_free_a_slot(tp, ent); 4445 ret++; 4446 } 4447 } 4448 return (ret); 4449 } 4450 4451 int 4452 tcp_req_is_entry_comp(struct tcpcb *tp, struct tcp_sendfile_track *ent, tcp_seq ack_point) 4453 { 4454 if (tp->t_tcpreq_req == 0) 4455 return(-1); 4456 if (tp->t_tcpreq_closed == 0) 4457 return(-1); 4458 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4459 return(-1); 4460 if (SEQ_GEQ(ack_point, ent->end_seq)) { 4461 return (1); 4462 } 4463 return (0); 4464 } 4465 4466 struct tcp_sendfile_track * 4467 tcp_req_find_a_req_that_is_completed_by(struct tcpcb *tp, tcp_seq th_ack, int *ip) 4468 { 4469 /* 4470 * Given an ack point (th_ack) walk through our entries and 4471 * return the first one found that th_ack goes past the 4472 * end_seq. 4473 */ 4474 struct tcp_sendfile_track *ent; 4475 int i; 4476 4477 if (tp->t_tcpreq_req == 0) { 4478 /* none open */ 4479 return (NULL); 4480 } 4481 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4482 ent = &tp->t_tcpreq_info[i]; 4483 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4484 continue; 4485 if ((ent->flags & TCP_TRK_TRACK_FLG_OPEN) == 0) { 4486 if (SEQ_GEQ(th_ack, ent->end_seq)) { 4487 *ip = i; 4488 return (ent); 4489 } 4490 } 4491 } 4492 return (NULL); 4493 } 4494 4495 struct tcp_sendfile_track * 4496 tcp_req_find_req_for_seq(struct tcpcb *tp, tcp_seq seq) 4497 { 4498 struct tcp_sendfile_track *ent; 4499 int i; 4500 4501 if (tp->t_tcpreq_req == 0) { 4502 /* none open */ 4503 return (NULL); 4504 } 4505 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4506 ent = &tp->t_tcpreq_info[i]; 4507 tcp_req_log_req_info(tp, ent, i, TCP_TRK_REQ_LOG_SEARCH, 4508 (uint64_t)seq, 0); 4509 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) { 4510 continue; 4511 } 4512 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) { 4513 /* 4514 * An open end request only needs to 4515 * match the beginning seq or be 4516 * all we have (once we keep going on 4517 * a open end request we may have a seq 4518 * wrap). 4519 */ 4520 if ((SEQ_GEQ(seq, ent->start_seq)) || 4521 (tp->t_tcpreq_closed == 0)) 4522 return (ent); 4523 } else { 4524 /* 4525 * For this one we need to 4526 * be a bit more careful if its 4527 * completed at least. 4528 */ 4529 if ((SEQ_GEQ(seq, ent->start_seq)) && 4530 (SEQ_LT(seq, ent->end_seq))) { 4531 return (ent); 4532 } 4533 } 4534 } 4535 return (NULL); 4536 } 4537 4538 /* Should this be in its own file tcp_req.c ? */ 4539 struct tcp_sendfile_track * 4540 tcp_req_alloc_req_full(struct tcpcb *tp, struct tcp_snd_req *req, uint64_t ts, int rec_dups) 4541 { 4542 struct tcp_sendfile_track *fil; 4543 int i, allocated; 4544 4545 /* In case the stack does not check for completions do so now */ 4546 tcp_req_check_for_comp(tp, tp->snd_una); 4547 /* Check for stale entries */ 4548 if (tp->t_tcpreq_req) 4549 tcp_req_check_for_stale_entries(tp, ts, 4550 (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ)); 4551 /* Check to see if this is a duplicate of one not started */ 4552 if (tp->t_tcpreq_req) { 4553 for(i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) { 4554 fil = &tp->t_tcpreq_info[i]; 4555 if (fil->flags != TCP_TRK_TRACK_FLG_USED) 4556 continue; 4557 if ((fil->timestamp == req->timestamp) && 4558 (fil->start == req->start) && 4559 ((fil->flags & TCP_TRK_TRACK_FLG_OPEN) || 4560 (fil->end == req->end))) { 4561 /* 4562 * We already have this request 4563 * and it has not been started with sendfile. 4564 * This probably means the user was returned 4565 * a 4xx of some sort and its going to age 4566 * out, lets not duplicate it. 4567 */ 4568 return(fil); 4569 } 4570 } 4571 } 4572 /* Ok if there is no room at the inn we are in trouble */ 4573 if (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ) { 4574 tcp_trace_point(tp, TCP_TP_REQ_LOG_FAIL); 4575 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4576 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], 4577 i, TCP_TRK_REQ_LOG_ALLOCFAIL, 0, 0); 4578 } 4579 return (NULL); 4580 } 4581 for(i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) { 4582 fil = &tp->t_tcpreq_info[i]; 4583 if (fil->flags == TCP_TRK_TRACK_FLG_EMPTY) { 4584 allocated = 1; 4585 fil->flags = TCP_TRK_TRACK_FLG_USED; 4586 fil->timestamp = req->timestamp; 4587 fil->localtime = ts; 4588 fil->start = req->start; 4589 if (req->flags & TCP_LOG_HTTPD_RANGE_END) { 4590 fil->end = req->end; 4591 } else { 4592 fil->end = 0; 4593 fil->flags |= TCP_TRK_TRACK_FLG_OPEN; 4594 } 4595 /* 4596 * We can set the min boundaries to the TCP Sequence space, 4597 * but it might be found to be further up when sendfile 4598 * actually runs on this range (if it ever does). 4599 */ 4600 fil->sbcc_at_s = tptosocket(tp)->so_snd.sb_ccc; 4601 fil->start_seq = tp->snd_una + 4602 tptosocket(tp)->so_snd.sb_ccc; 4603 fil->end_seq = (fil->start_seq + ((uint32_t)(fil->end - fil->start))); 4604 if (tptosocket(tp)->so_snd.sb_tls_info) { 4605 /* 4606 * This session is doing TLS. Take a swag guess 4607 * at the overhead. 4608 */ 4609 fil->end_seq += tcp_estimate_tls_overhead( 4610 tptosocket(tp), (fil->end - fil->start)); 4611 } 4612 tp->t_tcpreq_req++; 4613 if (fil->flags & TCP_TRK_TRACK_FLG_OPEN) 4614 tp->t_tcpreq_open++; 4615 else 4616 tp->t_tcpreq_closed++; 4617 tcp_req_log_req_info(tp, fil, i, 4618 TCP_TRK_REQ_LOG_NEW, 0, 0); 4619 break; 4620 } else 4621 fil = NULL; 4622 } 4623 return (fil); 4624 } 4625 4626 void 4627 tcp_req_alloc_req(struct tcpcb *tp, union tcp_log_userdata *user, uint64_t ts) 4628 { 4629 (void)tcp_req_alloc_req_full(tp, &user->tcp_req, ts, 1); 4630 } 4631 #endif 4632 4633 void 4634 tcp_log_socket_option(struct tcpcb *tp, uint32_t option_num, uint32_t option_val, int err) 4635 { 4636 if (tcp_bblogging_on(tp)) { 4637 struct tcp_log_buffer *l; 4638 4639 l = tcp_log_event(tp, NULL, 4640 &tptosocket(tp)->so_rcv, 4641 &tptosocket(tp)->so_snd, 4642 TCP_LOG_SOCKET_OPT, 4643 err, 0, NULL, 1, 4644 NULL, NULL, 0, NULL); 4645 if (l) { 4646 l->tlb_flex1 = option_num; 4647 l->tlb_flex2 = option_val; 4648 } 4649 } 4650 } 4651 4652 uint32_t 4653 tcp_get_srtt(struct tcpcb *tp, int granularity) 4654 { 4655 uint32_t srtt; 4656 4657 KASSERT(granularity == TCP_TMR_GRANULARITY_USEC || 4658 granularity == TCP_TMR_GRANULARITY_TICKS, 4659 ("%s: called with unexpected granularity %d", __func__, 4660 granularity)); 4661 4662 srtt = tp->t_srtt; 4663 4664 /* 4665 * We only support two granularities. If the stored granularity 4666 * does not match the granularity requested by the caller, 4667 * convert the stored value to the requested unit of granularity. 4668 */ 4669 if (tp->t_tmr_granularity != granularity) { 4670 if (granularity == TCP_TMR_GRANULARITY_USEC) 4671 srtt = TICKS_2_USEC(srtt); 4672 else 4673 srtt = USEC_2_TICKS(srtt); 4674 } 4675 4676 /* 4677 * If the srtt is stored with ticks granularity, we need to 4678 * unshift to get the actual value. We do this after the 4679 * conversion above (if one was necessary) in order to maximize 4680 * precision. 4681 */ 4682 if (tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS) 4683 srtt = srtt >> TCP_RTT_SHIFT; 4684 4685 return (srtt); 4686 } 4687