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 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_ipsec.h" 38 #include "opt_kern_tls.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/arb.h> 43 #include <sys/callout.h> 44 #include <sys/eventhandler.h> 45 #ifdef TCP_HHOOK 46 #include <sys/hhook.h> 47 #endif 48 #include <sys/kernel.h> 49 #ifdef TCP_HHOOK 50 #include <sys/khelp.h> 51 #endif 52 #ifdef KERN_TLS 53 #include <sys/ktls.h> 54 #endif 55 #include <sys/qmath.h> 56 #include <sys/stats.h> 57 #include <sys/sysctl.h> 58 #include <sys/jail.h> 59 #include <sys/malloc.h> 60 #include <sys/refcount.h> 61 #include <sys/mbuf.h> 62 #include <sys/priv.h> 63 #include <sys/proc.h> 64 #include <sys/sdt.h> 65 #include <sys/socket.h> 66 #include <sys/socketvar.h> 67 #include <sys/protosw.h> 68 #include <sys/random.h> 69 70 #include <vm/uma.h> 71 72 #include <net/route.h> 73 #include <net/route/nhop.h> 74 #include <net/if.h> 75 #include <net/if_var.h> 76 #include <net/if_private.h> 77 #include <net/vnet.h> 78 79 #include <netinet/in.h> 80 #include <netinet/in_fib.h> 81 #include <netinet/in_kdtrace.h> 82 #include <netinet/in_pcb.h> 83 #include <netinet/in_systm.h> 84 #include <netinet/in_var.h> 85 #include <netinet/ip.h> 86 #include <netinet/ip_icmp.h> 87 #include <netinet/ip_var.h> 88 #ifdef INET6 89 #include <netinet/icmp6.h> 90 #include <netinet/ip6.h> 91 #include <netinet6/in6_fib.h> 92 #include <netinet6/in6_pcb.h> 93 #include <netinet6/ip6_var.h> 94 #include <netinet6/scope6_var.h> 95 #include <netinet6/nd6.h> 96 #endif 97 98 #include <netinet/tcp.h> 99 #ifdef INVARIANTS 100 #define TCPSTATES 101 #endif 102 #include <netinet/tcp_fsm.h> 103 #include <netinet/tcp_seq.h> 104 #include <netinet/tcp_timer.h> 105 #include <netinet/tcp_var.h> 106 #include <netinet/tcp_ecn.h> 107 #include <netinet/tcp_log_buf.h> 108 #include <netinet/tcp_syncache.h> 109 #include <netinet/tcp_hpts.h> 110 #include <netinet/tcp_lro.h> 111 #include <netinet/cc/cc.h> 112 #include <netinet/tcpip.h> 113 #include <netinet/tcp_fastopen.h> 114 #include <netinet/tcp_accounting.h> 115 #ifdef TCPPCAP 116 #include <netinet/tcp_pcap.h> 117 #endif 118 #ifdef TCP_OFFLOAD 119 #include <netinet/tcp_offload.h> 120 #endif 121 #include <netinet/udp.h> 122 #include <netinet/udp_var.h> 123 #ifdef INET6 124 #include <netinet6/tcp6_var.h> 125 #endif 126 127 #include <netipsec/ipsec_support.h> 128 129 #include <machine/in_cksum.h> 130 #include <crypto/siphash/siphash.h> 131 132 #include <security/mac/mac_framework.h> 133 134 #ifdef INET6 135 static ip6proto_ctlinput_t tcp6_ctlinput; 136 static udp_tun_icmp_t tcp6_ctlinput_viaudp; 137 #endif 138 139 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 140 #ifdef INET6 141 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 142 #endif 143 144 #ifdef TCP_SAD_DETECTION 145 /* Sack attack detection thresholds and such */ 146 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, sack_attack, 147 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 148 "Sack Attack detection thresholds"); 149 int32_t tcp_force_detection = 0; 150 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, force_detection, 151 CTLFLAG_RW, 152 &tcp_force_detection, 0, 153 "Do we force detection even if the INP has it off?"); 154 int32_t tcp_sad_limit = 10000; 155 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, limit, 156 CTLFLAG_RW, 157 &tcp_sad_limit, 10000, 158 "If SaD is enabled, what is the limit to sendmap entries (0 = unlimited)?"); 159 int32_t tcp_sack_to_ack_thresh = 700; /* 70 % */ 160 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sack_to_ack_thresh, 161 CTLFLAG_RW, 162 &tcp_sack_to_ack_thresh, 700, 163 "Percentage of sacks to acks we must see above (10.1 percent is 101)?"); 164 int32_t tcp_sack_to_move_thresh = 600; /* 60 % */ 165 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, move_thresh, 166 CTLFLAG_RW, 167 &tcp_sack_to_move_thresh, 600, 168 "Percentage of sack moves we must see above (10.1 percent is 101)"); 169 int32_t tcp_restoral_thresh = 450; /* 45 % (sack:2:ack -25%) (mv:ratio -15%) **/ 170 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, restore_thresh, 171 CTLFLAG_RW, 172 &tcp_restoral_thresh, 450, 173 "Percentage of sack to ack percentage we must see below to restore(10.1 percent is 101)"); 174 int32_t tcp_sad_decay_val = 800; 175 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, decay_per, 176 CTLFLAG_RW, 177 &tcp_sad_decay_val, 800, 178 "The decay percentage (10.1 percent equals 101 )"); 179 int32_t tcp_map_minimum = 500; 180 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, nummaps, 181 CTLFLAG_RW, 182 &tcp_map_minimum, 500, 183 "Number of Map enteries before we start detection"); 184 int32_t tcp_sad_pacing_interval = 2000; 185 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_pacing_int, 186 CTLFLAG_RW, 187 &tcp_sad_pacing_interval, 2000, 188 "What is the minimum pacing interval for a classified attacker?"); 189 190 int32_t tcp_sad_low_pps = 100; 191 SYSCTL_INT(_net_inet_tcp_sack_attack, OID_AUTO, sad_low_pps, 192 CTLFLAG_RW, 193 &tcp_sad_low_pps, 100, 194 "What is the input pps that below which we do not decay?"); 195 #endif 196 uint32_t tcp_ack_war_time_window = 1000; 197 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow, 198 CTLFLAG_RW, 199 &tcp_ack_war_time_window, 1000, 200 "If the tcp_stack does ack-war prevention how many milliseconds are in its time window?"); 201 uint32_t tcp_ack_war_cnt = 5; 202 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, 203 CTLFLAG_RW, 204 &tcp_ack_war_cnt, 5, 205 "If the tcp_stack does ack-war prevention how many acks can be sent in its time window?"); 206 207 struct rwlock tcp_function_lock; 208 209 static int 210 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 211 { 212 int error, new; 213 214 new = V_tcp_mssdflt; 215 error = sysctl_handle_int(oidp, &new, 0, req); 216 if (error == 0 && req->newptr) { 217 if (new < TCP_MINMSS) 218 error = EINVAL; 219 else 220 V_tcp_mssdflt = new; 221 } 222 return (error); 223 } 224 225 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 227 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I", 228 "Default TCP Maximum Segment Size"); 229 230 #ifdef INET6 231 static int 232 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 233 { 234 int error, new; 235 236 new = V_tcp_v6mssdflt; 237 error = sysctl_handle_int(oidp, &new, 0, req); 238 if (error == 0 && req->newptr) { 239 if (new < TCP_MINMSS) 240 error = EINVAL; 241 else 242 V_tcp_v6mssdflt = new; 243 } 244 return (error); 245 } 246 247 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 248 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 249 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I", 250 "Default TCP Maximum Segment Size for IPv6"); 251 #endif /* INET6 */ 252 253 /* 254 * Minimum MSS we accept and use. This prevents DoS attacks where 255 * we are forced to a ridiculous low MSS like 20 and send hundreds 256 * of packets instead of one. The effect scales with the available 257 * bandwidth and quickly saturates the CPU and network interface 258 * with packet generation and sending. Set to zero to disable MINMSS 259 * checking. This setting prevents us from sending too small packets. 260 */ 261 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 262 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 263 &VNET_NAME(tcp_minmss), 0, 264 "Minimum TCP Maximum Segment Size"); 265 266 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 267 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 268 &VNET_NAME(tcp_do_rfc1323), 0, 269 "Enable rfc1323 (high performance TCP) extensions"); 270 271 /* 272 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014. 273 * Some stacks negotiate TS, but never send them after connection setup. Some 274 * stacks negotiate TS, but don't send them when sending keep-alive segments. 275 * These include modern widely deployed TCP stacks. 276 * Therefore tolerating violations for now... 277 */ 278 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1; 279 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW, 280 &VNET_NAME(tcp_tolerate_missing_ts), 0, 281 "Tolerate missing TCP timestamps"); 282 283 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1; 284 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW, 285 &VNET_NAME(tcp_ts_offset_per_conn), 0, 286 "Initialize TCP timestamps per connection instead of per host pair"); 287 288 /* How many connections are pacing */ 289 static volatile uint32_t number_of_tcp_connections_pacing = 0; 290 static uint32_t shadow_num_connections = 0; 291 static counter_u64_t tcp_pacing_failures; 292 293 static int tcp_pacing_limit = 10000; 294 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW, 295 &tcp_pacing_limit, 1000, 296 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)"); 297 298 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD, 299 &shadow_num_connections, 0, "Number of TCP connections being paced"); 300 301 SYSCTL_COUNTER_U64(_net_inet_tcp, OID_AUTO, pacing_failures, CTLFLAG_RD, 302 &tcp_pacing_failures, "Number of times we failed to enable pacing to avoid exceeding the limit"); 303 304 static int tcp_log_debug = 0; 305 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 306 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 307 308 /* 309 * Target size of TCP PCB hash tables. Must be a power of two. 310 * 311 * Note that this can be overridden by the kernel environment 312 * variable net.inet.tcp.tcbhashsize 313 */ 314 #ifndef TCBHASHSIZE 315 #define TCBHASHSIZE 0 316 #endif 317 static int tcp_tcbhashsize = TCBHASHSIZE; 318 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN, 319 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 320 321 static int do_tcpdrain = 1; 322 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 323 "Enable tcp_drain routine for extra help when low on mbufs"); 324 325 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 326 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 327 328 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1; 329 #define V_icmp_may_rst VNET(icmp_may_rst) 330 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 331 &VNET_NAME(icmp_may_rst), 0, 332 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 333 334 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0; 335 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 336 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 337 &VNET_NAME(tcp_isn_reseed_interval), 0, 338 "Seconds between reseeding of ISN secret"); 339 340 static int tcp_soreceive_stream; 341 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 342 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 343 344 VNET_DEFINE(uma_zone_t, sack_hole_zone); 345 #define V_sack_hole_zone VNET(sack_hole_zone) 346 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */ 347 static int 348 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS) 349 { 350 int error; 351 uint32_t new; 352 353 new = V_tcp_map_entries_limit; 354 error = sysctl_handle_int(oidp, &new, 0, req); 355 if (error == 0 && req->newptr) { 356 /* only allow "0" and value > minimum */ 357 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT) 358 error = EINVAL; 359 else 360 V_tcp_map_entries_limit = new; 361 } 362 return (error); 363 } 364 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit, 365 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 366 &VNET_NAME(tcp_map_entries_limit), 0, 367 &sysctl_net_inet_tcp_map_limit_check, "IU", 368 "Total sendmap entries limit"); 369 370 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */ 371 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW, 372 &VNET_NAME(tcp_map_split_limit), 0, 373 "Total sendmap split entries limit"); 374 375 #ifdef TCP_HHOOK 376 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 377 #endif 378 379 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH 380 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]); 381 #define V_ts_offset_secret VNET(ts_offset_secret) 382 383 static int tcp_default_fb_init(struct tcpcb *tp, void **ptr); 384 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged); 385 static int tcp_default_handoff_ok(struct tcpcb *tp); 386 static struct inpcb *tcp_notify(struct inpcb *, int); 387 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 388 static struct inpcb *tcp_mtudisc(struct inpcb *, int); 389 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int); 390 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 391 const void *ip4hdr, const void *ip6hdr); 392 static void tcp_default_switch_failed(struct tcpcb *tp); 393 static ipproto_ctlinput_t tcp_ctlinput; 394 static udp_tun_icmp_t tcp_ctlinput_viaudp; 395 396 static struct tcp_function_block tcp_def_funcblk = { 397 .tfb_tcp_block_name = "freebsd", 398 .tfb_tcp_output = tcp_default_output, 399 .tfb_tcp_do_segment = tcp_do_segment, 400 .tfb_tcp_ctloutput = tcp_default_ctloutput, 401 .tfb_tcp_handoff_ok = tcp_default_handoff_ok, 402 .tfb_tcp_fb_init = tcp_default_fb_init, 403 .tfb_tcp_fb_fini = tcp_default_fb_fini, 404 .tfb_switch_failed = tcp_default_switch_failed, 405 }; 406 407 static int tcp_fb_cnt = 0; 408 struct tcp_funchead t_functions; 409 VNET_DEFINE_STATIC(struct tcp_function_block *, tcp_func_set_ptr) = &tcp_def_funcblk; 410 #define V_tcp_func_set_ptr VNET(tcp_func_set_ptr) 411 412 void 413 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp) 414 { 415 TCPSTAT_INC(tcps_dsack_count); 416 tp->t_dsack_pack++; 417 if (tlp == 0) { 418 if (SEQ_GT(end, start)) { 419 tp->t_dsack_bytes += (end - start); 420 TCPSTAT_ADD(tcps_dsack_bytes, (end - start)); 421 } else { 422 tp->t_dsack_tlp_bytes += (start - end); 423 TCPSTAT_ADD(tcps_dsack_bytes, (start - end)); 424 } 425 } else { 426 if (SEQ_GT(end, start)) { 427 tp->t_dsack_bytes += (end - start); 428 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start)); 429 } else { 430 tp->t_dsack_tlp_bytes += (start - end); 431 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end)); 432 } 433 } 434 } 435 436 static struct tcp_function_block * 437 find_tcp_functions_locked(struct tcp_function_set *fs) 438 { 439 struct tcp_function *f; 440 struct tcp_function_block *blk=NULL; 441 442 TAILQ_FOREACH(f, &t_functions, tf_next) { 443 if (strcmp(f->tf_name, fs->function_set_name) == 0) { 444 blk = f->tf_fb; 445 break; 446 } 447 } 448 return(blk); 449 } 450 451 static struct tcp_function_block * 452 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 453 { 454 struct tcp_function_block *rblk=NULL; 455 struct tcp_function *f; 456 457 TAILQ_FOREACH(f, &t_functions, tf_next) { 458 if (f->tf_fb == blk) { 459 rblk = blk; 460 if (s) { 461 *s = f; 462 } 463 break; 464 } 465 } 466 return (rblk); 467 } 468 469 struct tcp_function_block * 470 find_and_ref_tcp_functions(struct tcp_function_set *fs) 471 { 472 struct tcp_function_block *blk; 473 474 rw_rlock(&tcp_function_lock); 475 blk = find_tcp_functions_locked(fs); 476 if (blk) 477 refcount_acquire(&blk->tfb_refcnt); 478 rw_runlock(&tcp_function_lock); 479 return(blk); 480 } 481 482 struct tcp_function_block * 483 find_and_ref_tcp_fb(struct tcp_function_block *blk) 484 { 485 struct tcp_function_block *rblk; 486 487 rw_rlock(&tcp_function_lock); 488 rblk = find_tcp_fb_locked(blk, NULL); 489 if (rblk) 490 refcount_acquire(&rblk->tfb_refcnt); 491 rw_runlock(&tcp_function_lock); 492 return(rblk); 493 } 494 495 /* Find a matching alias for the given tcp_function_block. */ 496 int 497 find_tcp_function_alias(struct tcp_function_block *blk, 498 struct tcp_function_set *fs) 499 { 500 struct tcp_function *f; 501 int found; 502 503 found = 0; 504 rw_rlock(&tcp_function_lock); 505 TAILQ_FOREACH(f, &t_functions, tf_next) { 506 if ((f->tf_fb == blk) && 507 (strncmp(f->tf_name, blk->tfb_tcp_block_name, 508 TCP_FUNCTION_NAME_LEN_MAX) != 0)) { 509 /* Matching function block with different name. */ 510 strncpy(fs->function_set_name, f->tf_name, 511 TCP_FUNCTION_NAME_LEN_MAX); 512 found = 1; 513 break; 514 } 515 } 516 /* Null terminate the string appropriately. */ 517 if (found) { 518 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0'; 519 } else { 520 fs->function_set_name[0] = '\0'; 521 } 522 rw_runlock(&tcp_function_lock); 523 return (found); 524 } 525 526 static struct tcp_function_block * 527 find_and_ref_tcp_default_fb(void) 528 { 529 struct tcp_function_block *rblk; 530 531 rw_rlock(&tcp_function_lock); 532 rblk = V_tcp_func_set_ptr; 533 refcount_acquire(&rblk->tfb_refcnt); 534 rw_runlock(&tcp_function_lock); 535 return (rblk); 536 } 537 538 void 539 tcp_switch_back_to_default(struct tcpcb *tp) 540 { 541 struct tcp_function_block *tfb; 542 void *ptr = NULL; 543 544 KASSERT(tp->t_fb != &tcp_def_funcblk, 545 ("%s: called by the built-in default stack", __func__)); 546 547 /* 548 * Now, we'll find a new function block to use. 549 * Start by trying the current user-selected 550 * default, unless this stack is the user-selected 551 * default. 552 */ 553 tfb = find_and_ref_tcp_default_fb(); 554 if (tfb == tp->t_fb) { 555 refcount_release(&tfb->tfb_refcnt); 556 tfb = NULL; 557 } 558 /* Does the stack accept this connection? */ 559 if (tfb != NULL && tfb->tfb_tcp_handoff_ok != NULL && 560 (*tfb->tfb_tcp_handoff_ok)(tp)) { 561 refcount_release(&tfb->tfb_refcnt); 562 tfb = NULL; 563 } 564 /* Try to use that stack. */ 565 if (tfb != NULL) { 566 /* Initialize the new stack. If it succeeds, we are done. */ 567 if (tfb->tfb_tcp_fb_init == NULL || 568 (*tfb->tfb_tcp_fb_init)(tp, &ptr) == 0) { 569 /* Release the old stack */ 570 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 571 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 572 refcount_release(&tp->t_fb->tfb_refcnt); 573 /* Now set in all the pointers */ 574 tp->t_fb = tfb; 575 tp->t_fb_ptr = ptr; 576 return; 577 } 578 /* 579 * Initialization failed. Release the reference count on 580 * the looked up default stack. 581 */ 582 refcount_release(&tfb->tfb_refcnt); 583 } 584 585 /* 586 * If that wasn't feasible, use the built-in default 587 * stack which is not allowed to reject anyone. 588 */ 589 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk); 590 if (tfb == NULL) { 591 /* there always should be a default */ 592 panic("Can't refer to tcp_def_funcblk"); 593 } 594 if (tfb->tfb_tcp_handoff_ok != NULL) { 595 if ((*tfb->tfb_tcp_handoff_ok) (tp)) { 596 /* The default stack cannot say no */ 597 panic("Default stack rejects a new session?"); 598 } 599 } 600 if (tfb->tfb_tcp_fb_init != NULL && 601 (*tfb->tfb_tcp_fb_init)(tp, &ptr)) { 602 /* The default stack cannot fail */ 603 panic("Default stack initialization failed"); 604 } 605 /* Now release the old stack */ 606 if (tp->t_fb->tfb_tcp_fb_fini != NULL) 607 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0); 608 refcount_release(&tp->t_fb->tfb_refcnt); 609 /* And set in the pointers to the new */ 610 tp->t_fb = tfb; 611 tp->t_fb_ptr = ptr; 612 } 613 614 static bool 615 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp, 616 const struct sockaddr *sa, void *ctx) 617 { 618 struct ip *iph; 619 #ifdef INET6 620 struct ip6_hdr *ip6; 621 #endif 622 struct udphdr *uh; 623 struct tcphdr *th; 624 int thlen; 625 uint16_t port; 626 627 TCPSTAT_INC(tcps_tunneled_pkts); 628 if ((m->m_flags & M_PKTHDR) == 0) { 629 /* Can't handle one that is not a pkt hdr */ 630 TCPSTAT_INC(tcps_tunneled_errs); 631 goto out; 632 } 633 thlen = sizeof(struct tcphdr); 634 if (m->m_len < off + sizeof(struct udphdr) + thlen && 635 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) { 636 TCPSTAT_INC(tcps_tunneled_errs); 637 goto out; 638 } 639 iph = mtod(m, struct ip *); 640 uh = (struct udphdr *)((caddr_t)iph + off); 641 th = (struct tcphdr *)(uh + 1); 642 thlen = th->th_off << 2; 643 if (m->m_len < off + sizeof(struct udphdr) + thlen) { 644 m = m_pullup(m, off + sizeof(struct udphdr) + thlen); 645 if (m == NULL) { 646 TCPSTAT_INC(tcps_tunneled_errs); 647 goto out; 648 } else { 649 iph = mtod(m, struct ip *); 650 uh = (struct udphdr *)((caddr_t)iph + off); 651 th = (struct tcphdr *)(uh + 1); 652 } 653 } 654 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport; 655 bcopy(th, uh, m->m_len - off); 656 m->m_len -= sizeof(struct udphdr); 657 m->m_pkthdr.len -= sizeof(struct udphdr); 658 /* 659 * We use the same algorithm for 660 * both UDP and TCP for c-sum. So 661 * the code in tcp_input will skip 662 * the checksum. So we do nothing 663 * with the flag (m->m_pkthdr.csum_flags). 664 */ 665 switch (iph->ip_v) { 666 #ifdef INET 667 case IPVERSION: 668 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr)); 669 tcp_input_with_port(&m, &off, IPPROTO_TCP, port); 670 break; 671 #endif 672 #ifdef INET6 673 case IPV6_VERSION >> 4: 674 ip6 = mtod(m, struct ip6_hdr *); 675 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr)); 676 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port); 677 break; 678 #endif 679 default: 680 goto out; 681 break; 682 } 683 return (true); 684 out: 685 m_freem(m); 686 687 return (true); 688 } 689 690 static int 691 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 692 { 693 int error=ENOENT; 694 struct tcp_function_set fs; 695 struct tcp_function_block *blk; 696 697 memset(&fs, 0, sizeof(fs)); 698 rw_rlock(&tcp_function_lock); 699 blk = find_tcp_fb_locked(V_tcp_func_set_ptr, NULL); 700 if (blk) { 701 /* Found him */ 702 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 703 fs.pcbcnt = blk->tfb_refcnt; 704 } 705 rw_runlock(&tcp_function_lock); 706 error = sysctl_handle_string(oidp, fs.function_set_name, 707 sizeof(fs.function_set_name), req); 708 709 /* Check for error or no change */ 710 if (error != 0 || req->newptr == NULL) 711 return(error); 712 713 rw_wlock(&tcp_function_lock); 714 blk = find_tcp_functions_locked(&fs); 715 if ((blk == NULL) || 716 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 717 error = ENOENT; 718 goto done; 719 } 720 V_tcp_func_set_ptr = blk; 721 done: 722 rw_wunlock(&tcp_function_lock); 723 return (error); 724 } 725 726 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 727 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 728 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 729 "Set/get the default TCP functions"); 730 731 static int 732 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 733 { 734 int error, cnt, linesz; 735 struct tcp_function *f; 736 char *buffer, *cp; 737 size_t bufsz, outsz; 738 bool alias; 739 740 cnt = 0; 741 rw_rlock(&tcp_function_lock); 742 TAILQ_FOREACH(f, &t_functions, tf_next) { 743 cnt++; 744 } 745 rw_runlock(&tcp_function_lock); 746 747 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1; 748 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 749 750 error = 0; 751 cp = buffer; 752 753 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D', 754 "Alias", "PCB count"); 755 cp += linesz; 756 bufsz -= linesz; 757 outsz = linesz; 758 759 rw_rlock(&tcp_function_lock); 760 TAILQ_FOREACH(f, &t_functions, tf_next) { 761 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name); 762 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n", 763 f->tf_fb->tfb_tcp_block_name, 764 (f->tf_fb == V_tcp_func_set_ptr) ? '*' : ' ', 765 alias ? f->tf_name : "-", 766 f->tf_fb->tfb_refcnt); 767 if (linesz >= bufsz) { 768 error = EOVERFLOW; 769 break; 770 } 771 cp += linesz; 772 bufsz -= linesz; 773 outsz += linesz; 774 } 775 rw_runlock(&tcp_function_lock); 776 if (error == 0) 777 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 778 free(buffer, M_TEMP); 779 return (error); 780 } 781 782 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 783 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 784 NULL, 0, sysctl_net_inet_list_available, "A", 785 "list available TCP Function sets"); 786 787 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT; 788 789 #ifdef INET 790 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL; 791 #define V_udp4_tun_socket VNET(udp4_tun_socket) 792 #endif 793 #ifdef INET6 794 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL; 795 #define V_udp6_tun_socket VNET(udp6_tun_socket) 796 #endif 797 798 static struct sx tcpoudp_lock; 799 800 static void 801 tcp_over_udp_stop(void) 802 { 803 804 sx_assert(&tcpoudp_lock, SA_XLOCKED); 805 806 #ifdef INET 807 if (V_udp4_tun_socket != NULL) { 808 soclose(V_udp4_tun_socket); 809 V_udp4_tun_socket = NULL; 810 } 811 #endif 812 #ifdef INET6 813 if (V_udp6_tun_socket != NULL) { 814 soclose(V_udp6_tun_socket); 815 V_udp6_tun_socket = NULL; 816 } 817 #endif 818 } 819 820 static int 821 tcp_over_udp_start(void) 822 { 823 uint16_t port; 824 int ret; 825 #ifdef INET 826 struct sockaddr_in sin; 827 #endif 828 #ifdef INET6 829 struct sockaddr_in6 sin6; 830 #endif 831 832 sx_assert(&tcpoudp_lock, SA_XLOCKED); 833 834 port = V_tcp_udp_tunneling_port; 835 if (ntohs(port) == 0) { 836 /* Must have a port set */ 837 return (EINVAL); 838 } 839 #ifdef INET 840 if (V_udp4_tun_socket != NULL) { 841 /* Already running -- must stop first */ 842 return (EALREADY); 843 } 844 #endif 845 #ifdef INET6 846 if (V_udp6_tun_socket != NULL) { 847 /* Already running -- must stop first */ 848 return (EALREADY); 849 } 850 #endif 851 #ifdef INET 852 if ((ret = socreate(PF_INET, &V_udp4_tun_socket, 853 SOCK_DGRAM, IPPROTO_UDP, 854 curthread->td_ucred, curthread))) { 855 tcp_over_udp_stop(); 856 return (ret); 857 } 858 /* Call the special UDP hook. */ 859 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket, 860 tcp_recv_udp_tunneled_packet, 861 tcp_ctlinput_viaudp, 862 NULL))) { 863 tcp_over_udp_stop(); 864 return (ret); 865 } 866 /* Ok, we have a socket, bind it to the port. */ 867 memset(&sin, 0, sizeof(struct sockaddr_in)); 868 sin.sin_len = sizeof(struct sockaddr_in); 869 sin.sin_family = AF_INET; 870 sin.sin_port = htons(port); 871 if ((ret = sobind(V_udp4_tun_socket, 872 (struct sockaddr *)&sin, curthread))) { 873 tcp_over_udp_stop(); 874 return (ret); 875 } 876 #endif 877 #ifdef INET6 878 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket, 879 SOCK_DGRAM, IPPROTO_UDP, 880 curthread->td_ucred, curthread))) { 881 tcp_over_udp_stop(); 882 return (ret); 883 } 884 /* Call the special UDP hook. */ 885 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket, 886 tcp_recv_udp_tunneled_packet, 887 tcp6_ctlinput_viaudp, 888 NULL))) { 889 tcp_over_udp_stop(); 890 return (ret); 891 } 892 /* Ok, we have a socket, bind it to the port. */ 893 memset(&sin6, 0, sizeof(struct sockaddr_in6)); 894 sin6.sin6_len = sizeof(struct sockaddr_in6); 895 sin6.sin6_family = AF_INET6; 896 sin6.sin6_port = htons(port); 897 if ((ret = sobind(V_udp6_tun_socket, 898 (struct sockaddr *)&sin6, curthread))) { 899 tcp_over_udp_stop(); 900 return (ret); 901 } 902 #endif 903 return (0); 904 } 905 906 static int 907 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS) 908 { 909 int error; 910 uint32_t old, new; 911 912 old = V_tcp_udp_tunneling_port; 913 new = old; 914 error = sysctl_handle_int(oidp, &new, 0, req); 915 if ((error == 0) && 916 (req->newptr != NULL)) { 917 if ((new < TCP_TUNNELING_PORT_MIN) || 918 (new > TCP_TUNNELING_PORT_MAX)) { 919 error = EINVAL; 920 } else { 921 sx_xlock(&tcpoudp_lock); 922 V_tcp_udp_tunneling_port = new; 923 if (old != 0) { 924 tcp_over_udp_stop(); 925 } 926 if (new != 0) { 927 error = tcp_over_udp_start(); 928 if (error != 0) { 929 V_tcp_udp_tunneling_port = 0; 930 } 931 } 932 sx_xunlock(&tcpoudp_lock); 933 } 934 } 935 return (error); 936 } 937 938 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port, 939 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 940 &VNET_NAME(tcp_udp_tunneling_port), 941 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU", 942 "Tunneling port for tcp over udp"); 943 944 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT; 945 946 static int 947 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS) 948 { 949 int error, new; 950 951 new = V_tcp_udp_tunneling_overhead; 952 error = sysctl_handle_int(oidp, &new, 0, req); 953 if (error == 0 && req->newptr) { 954 if ((new < TCP_TUNNELING_OVERHEAD_MIN) || 955 (new > TCP_TUNNELING_OVERHEAD_MAX)) 956 error = EINVAL; 957 else 958 V_tcp_udp_tunneling_overhead = new; 959 } 960 return (error); 961 } 962 963 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead, 964 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 965 &VNET_NAME(tcp_udp_tunneling_overhead), 966 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU", 967 "MSS reduction when using tcp over udp"); 968 969 /* 970 * Exports one (struct tcp_function_info) for each alias/name. 971 */ 972 static int 973 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS) 974 { 975 int cnt, error; 976 struct tcp_function *f; 977 struct tcp_function_info tfi; 978 979 /* 980 * We don't allow writes. 981 */ 982 if (req->newptr != NULL) 983 return (EINVAL); 984 985 /* 986 * Wire the old buffer so we can directly copy the functions to 987 * user space without dropping the lock. 988 */ 989 if (req->oldptr != NULL) { 990 error = sysctl_wire_old_buffer(req, 0); 991 if (error) 992 return (error); 993 } 994 995 /* 996 * Walk the list and copy out matching entries. If INVARIANTS 997 * is compiled in, also walk the list to verify the length of 998 * the list matches what we have recorded. 999 */ 1000 rw_rlock(&tcp_function_lock); 1001 1002 cnt = 0; 1003 #ifndef INVARIANTS 1004 if (req->oldptr == NULL) { 1005 cnt = tcp_fb_cnt; 1006 goto skip_loop; 1007 } 1008 #endif 1009 TAILQ_FOREACH(f, &t_functions, tf_next) { 1010 #ifdef INVARIANTS 1011 cnt++; 1012 #endif 1013 if (req->oldptr != NULL) { 1014 bzero(&tfi, sizeof(tfi)); 1015 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt; 1016 tfi.tfi_id = f->tf_fb->tfb_id; 1017 (void)strlcpy(tfi.tfi_alias, f->tf_name, 1018 sizeof(tfi.tfi_alias)); 1019 (void)strlcpy(tfi.tfi_name, 1020 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name)); 1021 error = SYSCTL_OUT(req, &tfi, sizeof(tfi)); 1022 /* 1023 * Don't stop on error, as that is the 1024 * mechanism we use to accumulate length 1025 * information if the buffer was too short. 1026 */ 1027 } 1028 } 1029 KASSERT(cnt == tcp_fb_cnt, 1030 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt)); 1031 #ifndef INVARIANTS 1032 skip_loop: 1033 #endif 1034 rw_runlock(&tcp_function_lock); 1035 if (req->oldptr == NULL) 1036 error = SYSCTL_OUT(req, NULL, 1037 (cnt + 1) * sizeof(struct tcp_function_info)); 1038 1039 return (error); 1040 } 1041 1042 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info, 1043 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE, 1044 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info", 1045 "List TCP function block name-to-ID mappings"); 1046 1047 /* 1048 * tfb_tcp_handoff_ok() function for the default stack. 1049 * Note that we'll basically try to take all comers. 1050 */ 1051 static int 1052 tcp_default_handoff_ok(struct tcpcb *tp) 1053 { 1054 1055 return (0); 1056 } 1057 1058 /* 1059 * tfb_tcp_fb_init() function for the default stack. 1060 * 1061 * This handles making sure we have appropriate timers set if you are 1062 * transitioning a socket that has some amount of setup done. 1063 * 1064 * The init() fuction from the default can *never* return non-zero i.e. 1065 * it is required to always succeed since it is the stack of last resort! 1066 */ 1067 static int 1068 tcp_default_fb_init(struct tcpcb *tp, void **ptr) 1069 { 1070 struct socket *so = tptosocket(tp); 1071 int rexmt; 1072 1073 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1074 /* We don't use the pointer */ 1075 *ptr = NULL; 1076 1077 KASSERT(tp->t_state >= 0 && tp->t_state < TCPS_TIME_WAIT, 1078 ("%s: connection %p in unexpected state %d", __func__, tp, 1079 tp->t_state)); 1080 1081 /* Make sure we get no interesting mbuf queuing behavior */ 1082 /* All mbuf queue/ack compress flags should be off */ 1083 tcp_lro_features_off(tp); 1084 1085 /* Cancel the GP measurement in progress */ 1086 tp->t_flags &= ~TF_GPUTINPROG; 1087 /* Validate the timers are not in usec, if they are convert */ 1088 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS); 1089 if ((tp->t_state == TCPS_SYN_SENT) || 1090 (tp->t_state == TCPS_SYN_RECEIVED)) 1091 rexmt = tcp_rexmit_initial * tcp_backoff[tp->t_rxtshift]; 1092 else 1093 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; 1094 if (tp->t_rxtshift == 0) 1095 tp->t_rxtcur = rexmt; 1096 else 1097 TCPT_RANGESET(tp->t_rxtcur, rexmt, tp->t_rttmin, TCPTV_REXMTMAX); 1098 1099 /* 1100 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't 1101 * know what to do for unexpected states (which includes TIME_WAIT). 1102 */ 1103 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT) 1104 return (0); 1105 1106 /* 1107 * Make sure some kind of transmission timer is set if there is 1108 * outstanding data. 1109 */ 1110 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) || 1111 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) || 1112 tcp_timer_active(tp, TT_PERSIST))) { 1113 /* 1114 * If the session has established and it looks like it should 1115 * be in the persist state, set the persist timer. Otherwise, 1116 * set the retransmit timer. 1117 */ 1118 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 && 1119 (int32_t)(tp->snd_nxt - tp->snd_una) < 1120 (int32_t)sbavail(&so->so_snd)) 1121 tcp_setpersist(tp); 1122 else 1123 tcp_timer_activate(tp, TT_REXMT, TP_RXTCUR(tp)); 1124 } 1125 1126 /* All non-embryonic sessions get a keepalive timer. */ 1127 if (!tcp_timer_active(tp, TT_KEEP)) 1128 tcp_timer_activate(tp, TT_KEEP, 1129 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) : 1130 TP_KEEPINIT(tp)); 1131 1132 /* 1133 * Make sure critical variables are initialized 1134 * if transitioning while in Recovery. 1135 */ 1136 if IN_FASTRECOVERY(tp->t_flags) { 1137 if (tp->sackhint.recover_fs == 0) 1138 tp->sackhint.recover_fs = max(1, 1139 tp->snd_nxt - tp->snd_una); 1140 } 1141 1142 return (0); 1143 } 1144 1145 /* 1146 * tfb_tcp_fb_fini() function for the default stack. 1147 * 1148 * This changes state as necessary (or prudent) to prepare for another stack 1149 * to assume responsibility for the connection. 1150 */ 1151 static void 1152 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged) 1153 { 1154 1155 INP_WLOCK_ASSERT(tptoinpcb(tp)); 1156 1157 #ifdef TCP_BLACKBOX 1158 tcp_log_flowend(tp); 1159 #endif 1160 tp->t_acktime = 0; 1161 return; 1162 } 1163 1164 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 1165 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 1166 1167 static struct mtx isn_mtx; 1168 1169 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 1170 #define ISN_LOCK() mtx_lock(&isn_mtx) 1171 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 1172 1173 INPCBSTORAGE_DEFINE(tcpcbstor, tcpcb, "tcpinp", "tcp_inpcb", "tcp", "tcphash"); 1174 1175 /* 1176 * Take a value and get the next power of 2 that doesn't overflow. 1177 * Used to size the tcp_inpcb hash buckets. 1178 */ 1179 static int 1180 maketcp_hashsize(int size) 1181 { 1182 int hashsize; 1183 1184 /* 1185 * auto tune. 1186 * get the next power of 2 higher than maxsockets. 1187 */ 1188 hashsize = 1 << fls(size); 1189 /* catch overflow, and just go one power of 2 smaller */ 1190 if (hashsize < size) { 1191 hashsize = 1 << (fls(size) - 1); 1192 } 1193 return (hashsize); 1194 } 1195 1196 static volatile int next_tcp_stack_id = 1; 1197 1198 /* 1199 * Register a TCP function block with the name provided in the names 1200 * array. (Note that this function does NOT automatically register 1201 * blk->tfb_tcp_block_name as a stack name. Therefore, you should 1202 * explicitly include blk->tfb_tcp_block_name in the list of names if 1203 * you wish to register the stack with that name.) 1204 * 1205 * Either all name registrations will succeed or all will fail. If 1206 * a name registration fails, the function will update the num_names 1207 * argument to point to the array index of the name that encountered 1208 * the failure. 1209 * 1210 * Returns 0 on success, or an error code on failure. 1211 */ 1212 int 1213 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, 1214 const char *names[], int *num_names) 1215 { 1216 struct tcp_function *n; 1217 struct tcp_function_set fs; 1218 int error, i; 1219 1220 KASSERT(names != NULL && *num_names > 0, 1221 ("%s: Called with 0-length name list", __func__)); 1222 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__)); 1223 KASSERT(rw_initialized(&tcp_function_lock), 1224 ("%s: called too early", __func__)); 1225 1226 if ((blk->tfb_tcp_output == NULL) || 1227 (blk->tfb_tcp_do_segment == NULL) || 1228 (blk->tfb_tcp_ctloutput == NULL) || 1229 (strlen(blk->tfb_tcp_block_name) == 0)) { 1230 /* 1231 * These functions are required and you 1232 * need a name. 1233 */ 1234 *num_names = 0; 1235 return (EINVAL); 1236 } 1237 1238 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) { 1239 *num_names = 0; 1240 return (EINVAL); 1241 } 1242 1243 refcount_init(&blk->tfb_refcnt, 0); 1244 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1); 1245 for (i = 0; i < *num_names; i++) { 1246 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 1247 if (n == NULL) { 1248 error = ENOMEM; 1249 goto cleanup; 1250 } 1251 n->tf_fb = blk; 1252 1253 (void)strlcpy(fs.function_set_name, names[i], 1254 sizeof(fs.function_set_name)); 1255 rw_wlock(&tcp_function_lock); 1256 if (find_tcp_functions_locked(&fs) != NULL) { 1257 /* Duplicate name space not allowed */ 1258 rw_wunlock(&tcp_function_lock); 1259 free(n, M_TCPFUNCTIONS); 1260 error = EALREADY; 1261 goto cleanup; 1262 } 1263 (void)strlcpy(n->tf_name, names[i], sizeof(n->tf_name)); 1264 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 1265 tcp_fb_cnt++; 1266 rw_wunlock(&tcp_function_lock); 1267 } 1268 return(0); 1269 1270 cleanup: 1271 /* 1272 * Deregister the names we just added. Because registration failed 1273 * for names[i], we don't need to deregister that name. 1274 */ 1275 *num_names = i; 1276 rw_wlock(&tcp_function_lock); 1277 while (--i >= 0) { 1278 TAILQ_FOREACH(n, &t_functions, tf_next) { 1279 if (!strncmp(n->tf_name, names[i], 1280 TCP_FUNCTION_NAME_LEN_MAX)) { 1281 TAILQ_REMOVE(&t_functions, n, tf_next); 1282 tcp_fb_cnt--; 1283 n->tf_fb = NULL; 1284 free(n, M_TCPFUNCTIONS); 1285 break; 1286 } 1287 } 1288 } 1289 rw_wunlock(&tcp_function_lock); 1290 return (error); 1291 } 1292 1293 /* 1294 * Register a TCP function block using the name provided in the name 1295 * argument. 1296 * 1297 * Returns 0 on success, or an error code on failure. 1298 */ 1299 int 1300 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, 1301 int wait) 1302 { 1303 const char *name_list[1]; 1304 int num_names, rv; 1305 1306 num_names = 1; 1307 if (name != NULL) 1308 name_list[0] = name; 1309 else 1310 name_list[0] = blk->tfb_tcp_block_name; 1311 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names); 1312 return (rv); 1313 } 1314 1315 /* 1316 * Register a TCP function block using the name defined in 1317 * blk->tfb_tcp_block_name. 1318 * 1319 * Returns 0 on success, or an error code on failure. 1320 */ 1321 int 1322 register_tcp_functions(struct tcp_function_block *blk, int wait) 1323 { 1324 1325 return (register_tcp_functions_as_name(blk, NULL, wait)); 1326 } 1327 1328 /* 1329 * Deregister all names associated with a function block. This 1330 * functionally removes the function block from use within the system. 1331 * 1332 * When called with a true quiesce argument, mark the function block 1333 * as being removed so no more stacks will use it and determine 1334 * whether the removal would succeed. 1335 * 1336 * When called with a false quiesce argument, actually attempt the 1337 * removal. 1338 * 1339 * When called with a force argument, attempt to switch all TCBs to 1340 * use the default stack instead of returning EBUSY. 1341 * 1342 * Returns 0 on success (or if the removal would succeed), or an error 1343 * code on failure. 1344 */ 1345 int 1346 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, 1347 bool force) 1348 { 1349 struct tcp_function *f; 1350 VNET_ITERATOR_DECL(vnet_iter); 1351 1352 if (blk == &tcp_def_funcblk) { 1353 /* You can't un-register the default */ 1354 return (EPERM); 1355 } 1356 rw_wlock(&tcp_function_lock); 1357 VNET_LIST_RLOCK_NOSLEEP(); 1358 VNET_FOREACH(vnet_iter) { 1359 CURVNET_SET(vnet_iter); 1360 if (blk == V_tcp_func_set_ptr) { 1361 /* You can't free the current default in some vnet. */ 1362 CURVNET_RESTORE(); 1363 VNET_LIST_RUNLOCK_NOSLEEP(); 1364 rw_wunlock(&tcp_function_lock); 1365 return (EBUSY); 1366 } 1367 CURVNET_RESTORE(); 1368 } 1369 VNET_LIST_RUNLOCK_NOSLEEP(); 1370 /* Mark the block so no more stacks can use it. */ 1371 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 1372 /* 1373 * If TCBs are still attached to the stack, attempt to switch them 1374 * to the default stack. 1375 */ 1376 if (force && blk->tfb_refcnt) { 1377 struct inpcb *inp; 1378 struct tcpcb *tp; 1379 VNET_ITERATOR_DECL(vnet_iter); 1380 1381 rw_wunlock(&tcp_function_lock); 1382 1383 VNET_LIST_RLOCK(); 1384 VNET_FOREACH(vnet_iter) { 1385 CURVNET_SET(vnet_iter); 1386 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1387 INPLOOKUP_WLOCKPCB); 1388 1389 while ((inp = inp_next(&inpi)) != NULL) { 1390 tp = intotcpcb(inp); 1391 if (tp == NULL || tp->t_fb != blk) 1392 continue; 1393 tcp_switch_back_to_default(tp); 1394 } 1395 CURVNET_RESTORE(); 1396 } 1397 VNET_LIST_RUNLOCK(); 1398 1399 rw_wlock(&tcp_function_lock); 1400 } 1401 if (blk->tfb_refcnt) { 1402 /* TCBs still attached. */ 1403 rw_wunlock(&tcp_function_lock); 1404 return (EBUSY); 1405 } 1406 if (quiesce) { 1407 /* Skip removal. */ 1408 rw_wunlock(&tcp_function_lock); 1409 return (0); 1410 } 1411 /* Remove any function names that map to this function block. */ 1412 while (find_tcp_fb_locked(blk, &f) != NULL) { 1413 TAILQ_REMOVE(&t_functions, f, tf_next); 1414 tcp_fb_cnt--; 1415 f->tf_fb = NULL; 1416 free(f, M_TCPFUNCTIONS); 1417 } 1418 rw_wunlock(&tcp_function_lock); 1419 return (0); 1420 } 1421 1422 static void 1423 tcp_drain(void) 1424 { 1425 struct epoch_tracker et; 1426 VNET_ITERATOR_DECL(vnet_iter); 1427 1428 if (!do_tcpdrain) 1429 return; 1430 1431 NET_EPOCH_ENTER(et); 1432 VNET_LIST_RLOCK_NOSLEEP(); 1433 VNET_FOREACH(vnet_iter) { 1434 CURVNET_SET(vnet_iter); 1435 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 1436 INPLOOKUP_WLOCKPCB); 1437 struct inpcb *inpb; 1438 struct tcpcb *tcpb; 1439 1440 /* 1441 * Walk the tcpbs, if existing, and flush the reassembly queue, 1442 * if there is one... 1443 * XXX: The "Net/3" implementation doesn't imply that the TCP 1444 * reassembly queue should be flushed, but in a situation 1445 * where we're really low on mbufs, this is potentially 1446 * useful. 1447 */ 1448 while ((inpb = inp_next(&inpi)) != NULL) { 1449 if ((tcpb = intotcpcb(inpb)) != NULL) { 1450 tcp_reass_flush(tcpb); 1451 tcp_clean_sackreport(tcpb); 1452 #ifdef TCP_BLACKBOX 1453 tcp_log_drain(tcpb); 1454 #endif 1455 #ifdef TCPPCAP 1456 if (tcp_pcap_aggressive_free) { 1457 /* Free the TCP PCAP queues. */ 1458 tcp_pcap_drain(&(tcpb->t_inpkts)); 1459 tcp_pcap_drain(&(tcpb->t_outpkts)); 1460 } 1461 #endif 1462 } 1463 } 1464 CURVNET_RESTORE(); 1465 } 1466 VNET_LIST_RUNLOCK_NOSLEEP(); 1467 NET_EPOCH_EXIT(et); 1468 } 1469 1470 static void 1471 tcp_vnet_init(void *arg __unused) 1472 { 1473 1474 #ifdef TCP_HHOOK 1475 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 1476 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1477 printf("%s: WARNING: unable to register helper hook\n", __func__); 1478 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 1479 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 1480 printf("%s: WARNING: unable to register helper hook\n", __func__); 1481 #endif 1482 #ifdef STATS 1483 if (tcp_stats_init()) 1484 printf("%s: WARNING: unable to initialise TCP stats\n", 1485 __func__); 1486 #endif 1487 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize, 1488 tcp_tcbhashsize); 1489 1490 syncache_init(); 1491 tcp_hc_init(); 1492 1493 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 1494 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 1495 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 1496 1497 tcp_fastopen_init(); 1498 1499 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK); 1500 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK); 1501 1502 V_tcp_msl = TCPTV_MSL; 1503 } 1504 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, 1505 tcp_vnet_init, NULL); 1506 1507 static void 1508 tcp_init(void *arg __unused) 1509 { 1510 int hashsize; 1511 1512 tcp_reass_global_init(); 1513 1514 /* XXX virtualize those below? */ 1515 tcp_delacktime = TCPTV_DELACK; 1516 tcp_keepinit = TCPTV_KEEP_INIT; 1517 tcp_keepidle = TCPTV_KEEP_IDLE; 1518 tcp_keepintvl = TCPTV_KEEPINTVL; 1519 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 1520 tcp_rexmit_initial = TCPTV_RTOBASE; 1521 if (tcp_rexmit_initial < 1) 1522 tcp_rexmit_initial = 1; 1523 tcp_rexmit_min = TCPTV_MIN; 1524 if (tcp_rexmit_min < 1) 1525 tcp_rexmit_min = 1; 1526 tcp_persmin = TCPTV_PERSMIN; 1527 tcp_persmax = TCPTV_PERSMAX; 1528 tcp_rexmit_slop = TCPTV_CPU_VAR; 1529 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 1530 1531 /* Setup the tcp function block list */ 1532 TAILQ_INIT(&t_functions); 1533 rw_init(&tcp_function_lock, "tcp_func_lock"); 1534 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 1535 sx_init(&tcpoudp_lock, "TCP over UDP configuration"); 1536 #ifdef TCP_BLACKBOX 1537 /* Initialize the TCP logging data. */ 1538 tcp_log_init(); 1539 #endif 1540 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0); 1541 1542 if (tcp_soreceive_stream) { 1543 #ifdef INET 1544 tcp_protosw.pr_soreceive = soreceive_stream; 1545 #endif 1546 #ifdef INET6 1547 tcp6_protosw.pr_soreceive = soreceive_stream; 1548 #endif /* INET6 */ 1549 } 1550 1551 #ifdef INET6 1552 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr)); 1553 #else /* INET6 */ 1554 max_protohdr_grow(sizeof(struct tcpiphdr)); 1555 #endif /* INET6 */ 1556 1557 ISN_LOCK_INIT(); 1558 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 1559 SHUTDOWN_PRI_DEFAULT); 1560 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1561 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT); 1562 1563 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK); 1564 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK); 1565 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK); 1566 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK); 1567 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK); 1568 tcp_would_have_but = counter_u64_alloc(M_WAITOK); 1569 tcp_comp_total = counter_u64_alloc(M_WAITOK); 1570 tcp_uncomp_total = counter_u64_alloc(M_WAITOK); 1571 tcp_bad_csums = counter_u64_alloc(M_WAITOK); 1572 tcp_pacing_failures = counter_u64_alloc(M_WAITOK); 1573 #ifdef TCPPCAP 1574 tcp_pcap_init(); 1575 #endif 1576 1577 hashsize = tcp_tcbhashsize; 1578 if (hashsize == 0) { 1579 /* 1580 * Auto tune the hash size based on maxsockets. 1581 * A perfect hash would have a 1:1 mapping 1582 * (hashsize = maxsockets) however it's been 1583 * suggested that O(2) average is better. 1584 */ 1585 hashsize = maketcp_hashsize(maxsockets / 4); 1586 /* 1587 * Our historical default is 512, 1588 * do not autotune lower than this. 1589 */ 1590 if (hashsize < 512) 1591 hashsize = 512; 1592 if (bootverbose) 1593 printf("%s: %s auto tuned to %d\n", __func__, 1594 "net.inet.tcp.tcbhashsize", hashsize); 1595 } 1596 /* 1597 * We require a hashsize to be a power of two. 1598 * Previously if it was not a power of two we would just reset it 1599 * back to 512, which could be a nasty surprise if you did not notice 1600 * the error message. 1601 * Instead what we do is clip it to the closest power of two lower 1602 * than the specified hash value. 1603 */ 1604 if (!powerof2(hashsize)) { 1605 int oldhashsize = hashsize; 1606 1607 hashsize = maketcp_hashsize(hashsize); 1608 /* prevent absurdly low value */ 1609 if (hashsize < 16) 1610 hashsize = 16; 1611 printf("%s: WARNING: TCB hash size not a power of 2, " 1612 "clipped from %d to %d.\n", __func__, oldhashsize, 1613 hashsize); 1614 } 1615 tcp_tcbhashsize = hashsize; 1616 1617 #ifdef INET 1618 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput); 1619 #endif 1620 #ifdef INET6 1621 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput); 1622 #endif 1623 } 1624 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL); 1625 1626 #ifdef VIMAGE 1627 static void 1628 tcp_destroy(void *unused __unused) 1629 { 1630 int n; 1631 #ifdef TCP_HHOOK 1632 int error; 1633 #endif 1634 1635 /* 1636 * All our processes are gone, all our sockets should be cleaned 1637 * up, which means, we should be past the tcp_discardcb() calls. 1638 * Sleep to let all tcpcb timers really disappear and cleanup. 1639 */ 1640 for (;;) { 1641 INP_INFO_WLOCK(&V_tcbinfo); 1642 n = V_tcbinfo.ipi_count; 1643 INP_INFO_WUNLOCK(&V_tcbinfo); 1644 if (n == 0) 1645 break; 1646 pause("tcpdes", hz / 10); 1647 } 1648 tcp_hc_destroy(); 1649 syncache_destroy(); 1650 in_pcbinfo_destroy(&V_tcbinfo); 1651 /* tcp_discardcb() clears the sack_holes up. */ 1652 uma_zdestroy(V_sack_hole_zone); 1653 1654 /* 1655 * Cannot free the zone until all tcpcbs are released as we attach 1656 * the allocations to them. 1657 */ 1658 tcp_fastopen_destroy(); 1659 1660 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES); 1661 VNET_PCPUSTAT_FREE(tcpstat); 1662 1663 #ifdef TCP_HHOOK 1664 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 1665 if (error != 0) { 1666 printf("%s: WARNING: unable to deregister helper hook " 1667 "type=%d, id=%d: error %d returned\n", __func__, 1668 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 1669 } 1670 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 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_OUT, error); 1675 } 1676 #endif 1677 } 1678 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 1679 #endif 1680 1681 void 1682 tcp_fini(void *xtp) 1683 { 1684 1685 } 1686 1687 /* 1688 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 1689 * tcp_template used to store this data in mbufs, but we now recopy it out 1690 * of the tcpcb each time to conserve mbufs. 1691 */ 1692 void 1693 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr) 1694 { 1695 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 1696 1697 INP_WLOCK_ASSERT(inp); 1698 1699 #ifdef INET6 1700 if ((inp->inp_vflag & INP_IPV6) != 0) { 1701 struct ip6_hdr *ip6; 1702 1703 ip6 = (struct ip6_hdr *)ip_ptr; 1704 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 1705 (inp->inp_flow & IPV6_FLOWINFO_MASK); 1706 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 1707 (IPV6_VERSION & IPV6_VERSION_MASK); 1708 if (port == 0) 1709 ip6->ip6_nxt = IPPROTO_TCP; 1710 else 1711 ip6->ip6_nxt = IPPROTO_UDP; 1712 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 1713 ip6->ip6_src = inp->in6p_laddr; 1714 ip6->ip6_dst = inp->in6p_faddr; 1715 } 1716 #endif /* INET6 */ 1717 #if defined(INET6) && defined(INET) 1718 else 1719 #endif 1720 #ifdef INET 1721 { 1722 struct ip *ip; 1723 1724 ip = (struct ip *)ip_ptr; 1725 ip->ip_v = IPVERSION; 1726 ip->ip_hl = 5; 1727 ip->ip_tos = inp->inp_ip_tos; 1728 ip->ip_len = 0; 1729 ip->ip_id = 0; 1730 ip->ip_off = 0; 1731 ip->ip_ttl = inp->inp_ip_ttl; 1732 ip->ip_sum = 0; 1733 if (port == 0) 1734 ip->ip_p = IPPROTO_TCP; 1735 else 1736 ip->ip_p = IPPROTO_UDP; 1737 ip->ip_src = inp->inp_laddr; 1738 ip->ip_dst = inp->inp_faddr; 1739 } 1740 #endif /* INET */ 1741 th->th_sport = inp->inp_lport; 1742 th->th_dport = inp->inp_fport; 1743 th->th_seq = 0; 1744 th->th_ack = 0; 1745 th->th_off = 5; 1746 tcp_set_flags(th, 0); 1747 th->th_win = 0; 1748 th->th_urp = 0; 1749 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 1750 } 1751 1752 /* 1753 * Create template to be used to send tcp packets on a connection. 1754 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 1755 * use for this function is in keepalives, which use tcp_respond. 1756 */ 1757 struct tcptemp * 1758 tcpip_maketemplate(struct inpcb *inp) 1759 { 1760 struct tcptemp *t; 1761 1762 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 1763 if (t == NULL) 1764 return (NULL); 1765 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t); 1766 return (t); 1767 } 1768 1769 /* 1770 * Send a single message to the TCP at address specified by 1771 * the given TCP/IP header. If m == NULL, then we make a copy 1772 * of the tcpiphdr at th and send directly to the addressed host. 1773 * This is used to force keep alive messages out using the TCP 1774 * template for a connection. If flags are given then we send 1775 * a message back to the TCP which originated the segment th, 1776 * and discard the mbuf containing it and any other attached mbufs. 1777 * 1778 * In any case the ack and sequence number of the transmitted 1779 * segment are as specified by the parameters. 1780 * 1781 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 1782 */ 1783 void 1784 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 1785 tcp_seq ack, tcp_seq seq, uint16_t flags) 1786 { 1787 struct tcpopt to; 1788 struct inpcb *inp; 1789 struct ip *ip; 1790 struct mbuf *optm; 1791 struct udphdr *uh = NULL; 1792 struct tcphdr *nth; 1793 struct tcp_log_buffer *lgb; 1794 u_char *optp; 1795 #ifdef INET6 1796 struct ip6_hdr *ip6; 1797 int isipv6; 1798 #endif /* INET6 */ 1799 int optlen, tlen, win, ulen; 1800 int ect = 0; 1801 bool incl_opts; 1802 uint16_t port; 1803 int output_ret; 1804 #ifdef INVARIANTS 1805 int thflags = tcp_get_flags(th); 1806 #endif 1807 1808 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 1809 NET_EPOCH_ASSERT(); 1810 1811 #ifdef INET6 1812 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 1813 ip6 = ipgen; 1814 #endif /* INET6 */ 1815 ip = ipgen; 1816 1817 if (tp != NULL) { 1818 inp = tptoinpcb(tp); 1819 INP_LOCK_ASSERT(inp); 1820 } else 1821 inp = NULL; 1822 1823 if (m != NULL) { 1824 #ifdef INET6 1825 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP)) 1826 port = m->m_pkthdr.tcp_tun_port; 1827 else 1828 #endif 1829 if (ip && (ip->ip_p == IPPROTO_UDP)) 1830 port = m->m_pkthdr.tcp_tun_port; 1831 else 1832 port = 0; 1833 } else 1834 port = tp->t_port; 1835 1836 incl_opts = false; 1837 win = 0; 1838 if (tp != NULL) { 1839 if (!(flags & TH_RST)) { 1840 win = sbspace(&inp->inp_socket->so_rcv); 1841 if (win > TCP_MAXWIN << tp->rcv_scale) 1842 win = TCP_MAXWIN << tp->rcv_scale; 1843 } 1844 if ((tp->t_flags & TF_NOOPT) == 0) 1845 incl_opts = true; 1846 } 1847 if (m == NULL) { 1848 m = m_gethdr(M_NOWAIT, MT_DATA); 1849 if (m == NULL) 1850 return; 1851 m->m_data += max_linkhdr; 1852 #ifdef INET6 1853 if (isipv6) { 1854 bcopy((caddr_t)ip6, mtod(m, caddr_t), 1855 sizeof(struct ip6_hdr)); 1856 ip6 = mtod(m, struct ip6_hdr *); 1857 nth = (struct tcphdr *)(ip6 + 1); 1858 if (port) { 1859 /* Insert a UDP header */ 1860 uh = (struct udphdr *)nth; 1861 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1862 uh->uh_dport = port; 1863 nth = (struct tcphdr *)(uh + 1); 1864 } 1865 } else 1866 #endif /* INET6 */ 1867 { 1868 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 1869 ip = mtod(m, struct ip *); 1870 nth = (struct tcphdr *)(ip + 1); 1871 if (port) { 1872 /* Insert a UDP header */ 1873 uh = (struct udphdr *)nth; 1874 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1875 uh->uh_dport = port; 1876 nth = (struct tcphdr *)(uh + 1); 1877 } 1878 } 1879 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1880 flags = TH_ACK; 1881 } else if ((!M_WRITABLE(m)) || (port != 0)) { 1882 struct mbuf *n; 1883 1884 /* Can't reuse 'm', allocate a new mbuf. */ 1885 n = m_gethdr(M_NOWAIT, MT_DATA); 1886 if (n == NULL) { 1887 m_freem(m); 1888 return; 1889 } 1890 1891 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 1892 m_freem(m); 1893 m_freem(n); 1894 return; 1895 } 1896 1897 n->m_data += max_linkhdr; 1898 /* m_len is set later */ 1899 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 1900 #ifdef INET6 1901 if (isipv6) { 1902 bcopy((caddr_t)ip6, mtod(n, caddr_t), 1903 sizeof(struct ip6_hdr)); 1904 ip6 = mtod(n, struct ip6_hdr *); 1905 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1906 nth = (struct tcphdr *)(ip6 + 1); 1907 if (port) { 1908 /* Insert a UDP header */ 1909 uh = (struct udphdr *)nth; 1910 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1911 uh->uh_dport = port; 1912 nth = (struct tcphdr *)(uh + 1); 1913 } 1914 } else 1915 #endif /* INET6 */ 1916 { 1917 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 1918 ip = mtod(n, struct ip *); 1919 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1920 nth = (struct tcphdr *)(ip + 1); 1921 if (port) { 1922 /* Insert a UDP header */ 1923 uh = (struct udphdr *)nth; 1924 uh->uh_sport = htons(V_tcp_udp_tunneling_port); 1925 uh->uh_dport = port; 1926 nth = (struct tcphdr *)(uh + 1); 1927 } 1928 } 1929 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 1930 xchg(nth->th_dport, nth->th_sport, uint16_t); 1931 th = nth; 1932 m_freem(m); 1933 m = n; 1934 } else { 1935 /* 1936 * reuse the mbuf. 1937 * XXX MRT We inherit the FIB, which is lucky. 1938 */ 1939 m_freem(m->m_next); 1940 m->m_next = NULL; 1941 m->m_data = (caddr_t)ipgen; 1942 /* clear any receive flags for proper bpf timestamping */ 1943 m->m_flags &= ~(M_TSTMP | M_TSTMP_LRO); 1944 /* m_len is set later */ 1945 #ifdef INET6 1946 if (isipv6) { 1947 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 1948 nth = (struct tcphdr *)(ip6 + 1); 1949 } else 1950 #endif /* INET6 */ 1951 { 1952 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 1953 nth = (struct tcphdr *)(ip + 1); 1954 } 1955 if (th != nth) { 1956 /* 1957 * this is usually a case when an extension header 1958 * exists between the IPv6 header and the 1959 * TCP header. 1960 */ 1961 nth->th_sport = th->th_sport; 1962 nth->th_dport = th->th_dport; 1963 } 1964 xchg(nth->th_dport, nth->th_sport, uint16_t); 1965 #undef xchg 1966 } 1967 tlen = 0; 1968 #ifdef INET6 1969 if (isipv6) 1970 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1971 #endif 1972 #if defined(INET) && defined(INET6) 1973 else 1974 #endif 1975 #ifdef INET 1976 tlen = sizeof (struct tcpiphdr); 1977 #endif 1978 if (port) 1979 tlen += sizeof (struct udphdr); 1980 #ifdef INVARIANTS 1981 m->m_len = 0; 1982 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1983 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1984 m, tlen, (long)M_TRAILINGSPACE(m))); 1985 #endif 1986 m->m_len = tlen; 1987 to.to_flags = 0; 1988 if (incl_opts) { 1989 ect = tcp_ecn_output_established(tp, &flags, 0, false); 1990 /* Make sure we have room. */ 1991 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1992 m->m_next = m_get(M_NOWAIT, MT_DATA); 1993 if (m->m_next) { 1994 optp = mtod(m->m_next, u_char *); 1995 optm = m->m_next; 1996 } else 1997 incl_opts = false; 1998 } else { 1999 optp = (u_char *) (nth + 1); 2000 optm = m; 2001 } 2002 } 2003 if (incl_opts) { 2004 /* Timestamps. */ 2005 if (tp->t_flags & TF_RCVD_TSTMP) { 2006 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 2007 to.to_tsecr = tp->ts_recent; 2008 to.to_flags |= TOF_TS; 2009 } 2010 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2011 /* TCP-MD5 (RFC2385). */ 2012 if (tp->t_flags & TF_SIGNATURE) 2013 to.to_flags |= TOF_SIGNATURE; 2014 #endif 2015 /* Add the options. */ 2016 tlen += optlen = tcp_addoptions(&to, optp); 2017 2018 /* Update m_len in the correct mbuf. */ 2019 optm->m_len += optlen; 2020 } else 2021 optlen = 0; 2022 #ifdef INET6 2023 if (isipv6) { 2024 if (uh) { 2025 ulen = tlen - sizeof(struct ip6_hdr); 2026 uh->uh_ulen = htons(ulen); 2027 } 2028 ip6->ip6_flow = htonl(ect << IPV6_FLOWLABEL_LEN); 2029 ip6->ip6_vfc = IPV6_VERSION; 2030 if (port) 2031 ip6->ip6_nxt = IPPROTO_UDP; 2032 else 2033 ip6->ip6_nxt = IPPROTO_TCP; 2034 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 2035 } 2036 #endif 2037 #if defined(INET) && defined(INET6) 2038 else 2039 #endif 2040 #ifdef INET 2041 { 2042 if (uh) { 2043 ulen = tlen - sizeof(struct ip); 2044 uh->uh_ulen = htons(ulen); 2045 } 2046 ip->ip_len = htons(tlen); 2047 if (inp != NULL) { 2048 ip->ip_tos = inp->inp_ip_tos & ~IPTOS_ECN_MASK; 2049 ip->ip_ttl = inp->inp_ip_ttl; 2050 } else { 2051 ip->ip_tos = 0; 2052 ip->ip_ttl = V_ip_defttl; 2053 } 2054 ip->ip_tos |= ect; 2055 if (port) { 2056 ip->ip_p = IPPROTO_UDP; 2057 } else { 2058 ip->ip_p = IPPROTO_TCP; 2059 } 2060 if (V_path_mtu_discovery) 2061 ip->ip_off |= htons(IP_DF); 2062 } 2063 #endif 2064 m->m_pkthdr.len = tlen; 2065 m->m_pkthdr.rcvif = NULL; 2066 #ifdef MAC 2067 if (inp != NULL) { 2068 /* 2069 * Packet is associated with a socket, so allow the 2070 * label of the response to reflect the socket label. 2071 */ 2072 INP_LOCK_ASSERT(inp); 2073 mac_inpcb_create_mbuf(inp, m); 2074 } else { 2075 /* 2076 * Packet is not associated with a socket, so possibly 2077 * update the label in place. 2078 */ 2079 mac_netinet_tcp_reply(m); 2080 } 2081 #endif 2082 nth->th_seq = htonl(seq); 2083 nth->th_ack = htonl(ack); 2084 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 2085 tcp_set_flags(nth, flags); 2086 if (tp && (flags & TH_RST)) { 2087 /* Log the reset */ 2088 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST); 2089 } 2090 if (tp != NULL) 2091 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 2092 else 2093 nth->th_win = htons((u_short)win); 2094 nth->th_urp = 0; 2095 2096 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2097 if (to.to_flags & TOF_SIGNATURE) { 2098 if (!TCPMD5_ENABLED() || 2099 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 2100 m_freem(m); 2101 return; 2102 } 2103 } 2104 #endif 2105 2106 #ifdef INET6 2107 if (isipv6) { 2108 if (port) { 2109 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6; 2110 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2111 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0); 2112 nth->th_sum = 0; 2113 } else { 2114 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2115 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2116 nth->th_sum = in6_cksum_pseudo(ip6, 2117 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 2118 } 2119 ip6->ip6_hlim = in6_selecthlim(inp, NULL); 2120 } 2121 #endif /* INET6 */ 2122 #if defined(INET6) && defined(INET) 2123 else 2124 #endif 2125 #ifdef INET 2126 { 2127 if (port) { 2128 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2129 htons(ulen + IPPROTO_UDP)); 2130 m->m_pkthdr.csum_flags = CSUM_UDP; 2131 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum); 2132 nth->th_sum = 0; 2133 } else { 2134 m->m_pkthdr.csum_flags = CSUM_TCP; 2135 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2136 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2137 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 2138 } 2139 } 2140 #endif /* INET */ 2141 TCP_PROBE3(debug__output, tp, th, m); 2142 if (flags & TH_RST) 2143 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 2144 lgb = NULL; 2145 if ((tp != NULL) && tcp_bblogging_on(tp)) { 2146 if (INP_WLOCKED(inp)) { 2147 union tcp_log_stackspecific log; 2148 struct timeval tv; 2149 2150 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 2151 log.u_bbr.inhpts = tcp_in_hpts(tp); 2152 log.u_bbr.flex8 = 4; 2153 log.u_bbr.pkts_out = tp->t_maxseg; 2154 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 2155 log.u_bbr.delivered = 0; 2156 lgb = tcp_log_event(tp, nth, NULL, NULL, TCP_LOG_OUT, 2157 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv); 2158 } else { 2159 /* 2160 * We can not log the packet, since we only own the 2161 * read lock, but a write lock is needed. The read lock 2162 * is not upgraded to a write lock, since only getting 2163 * the read lock was done intentionally to improve the 2164 * handling of SYN flooding attacks. 2165 * This happens only for pure SYN segments received in 2166 * the initial CLOSED state, or received in a more 2167 * advanced state than listen and the UDP encapsulation 2168 * port is unexpected. 2169 * The incoming SYN segments do not really belong to 2170 * the TCP connection and the handling does not change 2171 * the state of the TCP connection. Therefore, the 2172 * sending of the RST segments is not logged. Please 2173 * note that also the incoming SYN segments are not 2174 * logged. 2175 * 2176 * The following code ensures that the above description 2177 * is and stays correct. 2178 */ 2179 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN && 2180 (tp->t_state == TCPS_CLOSED || 2181 (tp->t_state > TCPS_LISTEN && tp->t_port != port)), 2182 ("%s: Logging of TCP segment with flags 0x%b and " 2183 "UDP encapsulation port %u skipped in state %s", 2184 __func__, thflags, PRINT_TH_FLAGS, 2185 ntohs(port), tcpstates[tp->t_state])); 2186 } 2187 } 2188 2189 if (flags & TH_ACK) 2190 TCPSTAT_INC(tcps_sndacks); 2191 else if (flags & (TH_SYN|TH_FIN|TH_RST)) 2192 TCPSTAT_INC(tcps_sndctrl); 2193 TCPSTAT_INC(tcps_sndtotal); 2194 2195 #ifdef INET6 2196 if (isipv6) { 2197 TCP_PROBE5(send, NULL, tp, ip6, tp, nth); 2198 output_ret = ip6_output(m, inp ? inp->in6p_outputopts : NULL, 2199 NULL, 0, NULL, NULL, inp); 2200 } 2201 #endif /* INET6 */ 2202 #if defined(INET) && defined(INET6) 2203 else 2204 #endif 2205 #ifdef INET 2206 { 2207 TCP_PROBE5(send, NULL, tp, ip, tp, nth); 2208 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp); 2209 } 2210 #endif 2211 if (lgb != NULL) 2212 lgb->tlb_errno = output_ret; 2213 } 2214 2215 /* 2216 * Create a new TCP control block, making an empty reassembly queue and hooking 2217 * it to the argument protocol control block. The `inp' parameter must have 2218 * come from the zone allocator set up by tcpcbstor declaration. 2219 */ 2220 struct tcpcb * 2221 tcp_newtcpcb(struct inpcb *inp) 2222 { 2223 struct tcpcb *tp = intotcpcb(inp); 2224 #ifdef INET6 2225 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2226 #endif /* INET6 */ 2227 2228 /* 2229 * Historically allocation was done with M_ZERO. There is a lot of 2230 * code that rely on that. For now take safe approach and zero whole 2231 * tcpcb. This definitely can be optimized. 2232 */ 2233 bzero(&tp->t_start_zero, t_zero_size); 2234 2235 /* Initialise cc_var struct for this tcpcb. */ 2236 tp->t_ccv.type = IPPROTO_TCP; 2237 tp->t_ccv.ccvc.tcp = tp; 2238 rw_rlock(&tcp_function_lock); 2239 tp->t_fb = V_tcp_func_set_ptr; 2240 refcount_acquire(&tp->t_fb->tfb_refcnt); 2241 rw_runlock(&tcp_function_lock); 2242 /* 2243 * Use the current system default CC algorithm. 2244 */ 2245 cc_attach(tp, CC_DEFAULT_ALGO()); 2246 2247 if (CC_ALGO(tp)->cb_init != NULL) 2248 if (CC_ALGO(tp)->cb_init(&tp->t_ccv, NULL) > 0) { 2249 cc_detach(tp); 2250 if (tp->t_fb->tfb_tcp_fb_fini) 2251 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2252 refcount_release(&tp->t_fb->tfb_refcnt); 2253 return (NULL); 2254 } 2255 2256 #ifdef TCP_HHOOK 2257 if (khelp_init_osd(HELPER_CLASS_TCP, &tp->t_osd)) { 2258 if (tp->t_fb->tfb_tcp_fb_fini) 2259 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2260 refcount_release(&tp->t_fb->tfb_refcnt); 2261 return (NULL); 2262 } 2263 #endif 2264 2265 TAILQ_INIT(&tp->t_segq); 2266 STAILQ_INIT(&tp->t_inqueue); 2267 tp->t_maxseg = 2268 #ifdef INET6 2269 isipv6 ? V_tcp_v6mssdflt : 2270 #endif /* INET6 */ 2271 V_tcp_mssdflt; 2272 2273 /* All mbuf queue/ack compress flags should be off */ 2274 tcp_lro_features_off(tp); 2275 2276 callout_init_rw(&tp->t_callout, &inp->inp_lock, CALLOUT_RETURNUNLOCKED); 2277 for (int i = 0; i < TT_N; i++) 2278 tp->t_timers[i] = SBT_MAX; 2279 2280 switch (V_tcp_do_rfc1323) { 2281 case 0: 2282 break; 2283 default: 2284 case 1: 2285 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2286 break; 2287 case 2: 2288 tp->t_flags = TF_REQ_SCALE; 2289 break; 2290 case 3: 2291 tp->t_flags = TF_REQ_TSTMP; 2292 break; 2293 } 2294 if (V_tcp_do_sack) 2295 tp->t_flags |= TF_SACK_PERMIT; 2296 TAILQ_INIT(&tp->snd_holes); 2297 2298 /* 2299 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 2300 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 2301 * reasonable initial retransmit time. 2302 */ 2303 tp->t_srtt = TCPTV_SRTTBASE; 2304 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 2305 tp->t_rttmin = tcp_rexmit_min; 2306 tp->t_rxtcur = tcp_rexmit_initial; 2307 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2308 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 2309 tp->t_rcvtime = ticks; 2310 /* We always start with ticks granularity */ 2311 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS; 2312 /* 2313 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 2314 * because the socket may be bound to an IPv6 wildcard address, 2315 * which may match an IPv4-mapped IPv6 address. 2316 */ 2317 inp->inp_ip_ttl = V_ip_defttl; 2318 #ifdef TCPHPTS 2319 tcp_hpts_init(tp); 2320 #endif 2321 #ifdef TCPPCAP 2322 /* 2323 * Init the TCP PCAP queues. 2324 */ 2325 tcp_pcap_tcpcb_init(tp); 2326 #endif 2327 #ifdef TCP_BLACKBOX 2328 /* Initialize the per-TCPCB log data. */ 2329 tcp_log_tcpcbinit(tp); 2330 #endif 2331 tp->t_pacing_rate = -1; 2332 if (tp->t_fb->tfb_tcp_fb_init) { 2333 if ((*tp->t_fb->tfb_tcp_fb_init)(tp, &tp->t_fb_ptr)) { 2334 refcount_release(&tp->t_fb->tfb_refcnt); 2335 return (NULL); 2336 } 2337 } 2338 #ifdef STATS 2339 if (V_tcp_perconn_stats_enable == 1) 2340 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0); 2341 #endif 2342 if (V_tcp_do_lrd) 2343 tp->t_flags |= TF_LRD; 2344 2345 return (tp); 2346 } 2347 2348 /* 2349 * Drop a TCP connection, reporting 2350 * the specified error. If connection is synchronized, 2351 * then send a RST to peer. 2352 */ 2353 struct tcpcb * 2354 tcp_drop(struct tcpcb *tp, int errno) 2355 { 2356 struct socket *so = tptosocket(tp); 2357 2358 NET_EPOCH_ASSERT(); 2359 INP_WLOCK_ASSERT(tptoinpcb(tp)); 2360 2361 if (TCPS_HAVERCVDSYN(tp->t_state)) { 2362 tcp_state_change(tp, TCPS_CLOSED); 2363 /* Don't use tcp_output() here due to possible recursion. */ 2364 (void)tcp_output_nodrop(tp); 2365 TCPSTAT_INC(tcps_drops); 2366 } else 2367 TCPSTAT_INC(tcps_conndrops); 2368 if (errno == ETIMEDOUT && tp->t_softerror) 2369 errno = tp->t_softerror; 2370 so->so_error = errno; 2371 return (tcp_close(tp)); 2372 } 2373 2374 void 2375 tcp_discardcb(struct tcpcb *tp) 2376 { 2377 struct inpcb *inp = tptoinpcb(tp); 2378 struct socket *so = tptosocket(tp); 2379 struct mbuf *m; 2380 #ifdef INET6 2381 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 2382 #endif 2383 2384 INP_WLOCK_ASSERT(inp); 2385 2386 tcp_timer_stop(tp); 2387 if (tp->t_fb->tfb_tcp_timer_stop_all) { 2388 tp->t_fb->tfb_tcp_timer_stop_all(tp); 2389 } 2390 2391 /* free the reassembly queue, if any */ 2392 tcp_reass_flush(tp); 2393 2394 #ifdef TCP_OFFLOAD 2395 /* Disconnect offload device, if any. */ 2396 if (tp->t_flags & TF_TOE) 2397 tcp_offload_detach(tp); 2398 #endif 2399 2400 tcp_free_sackholes(tp); 2401 2402 #ifdef TCPPCAP 2403 /* Free the TCP PCAP queues. */ 2404 tcp_pcap_drain(&(tp->t_inpkts)); 2405 tcp_pcap_drain(&(tp->t_outpkts)); 2406 #endif 2407 2408 /* Allow the CC algorithm to clean up after itself. */ 2409 if (CC_ALGO(tp)->cb_destroy != NULL) 2410 CC_ALGO(tp)->cb_destroy(&tp->t_ccv); 2411 CC_DATA(tp) = NULL; 2412 /* Detach from the CC algorithm */ 2413 cc_detach(tp); 2414 2415 #ifdef TCP_HHOOK 2416 khelp_destroy_osd(&tp->t_osd); 2417 #endif 2418 #ifdef STATS 2419 stats_blob_destroy(tp->t_stats); 2420 #endif 2421 2422 CC_ALGO(tp) = NULL; 2423 if ((m = STAILQ_FIRST(&tp->t_inqueue)) != NULL) { 2424 struct mbuf *prev; 2425 2426 STAILQ_INIT(&tp->t_inqueue); 2427 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, prev) 2428 m_freem(m); 2429 } 2430 TCPSTATES_DEC(tp->t_state); 2431 2432 if (tp->t_fb->tfb_tcp_fb_fini) 2433 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 2434 MPASS(!tcp_in_hpts(tp)); 2435 #ifdef TCP_BLACKBOX 2436 tcp_log_tcpcbfini(tp); 2437 #endif 2438 2439 /* 2440 * If we got enough samples through the srtt filter, 2441 * save the rtt and rttvar in the routing entry. 2442 * 'Enough' is arbitrarily defined as 4 rtt samples. 2443 * 4 samples is enough for the srtt filter to converge 2444 * to within enough % of the correct value; fewer samples 2445 * and we could save a bogus rtt. The danger is not high 2446 * as tcp quickly recovers from everything. 2447 * XXX: Works very well but needs some more statistics! 2448 * 2449 * XXXRRS: Updating must be after the stack fini() since 2450 * that may be converting some internal representation of 2451 * say srtt etc into the general one used by other stacks. 2452 * Lets also at least protect against the so being NULL 2453 * as RW stated below. 2454 */ 2455 if ((tp->t_rttupdated >= 4) && (so != NULL)) { 2456 struct hc_metrics_lite metrics; 2457 uint32_t ssthresh; 2458 2459 bzero(&metrics, sizeof(metrics)); 2460 /* 2461 * Update the ssthresh always when the conditions below 2462 * are satisfied. This gives us better new start value 2463 * for the congestion avoidance for new connections. 2464 * ssthresh is only set if packet loss occurred on a session. 2465 * 2466 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 2467 * being torn down. Ideally this code would not use 'so'. 2468 */ 2469 ssthresh = tp->snd_ssthresh; 2470 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 2471 /* 2472 * convert the limit from user data bytes to 2473 * packets then to packet data bytes. 2474 */ 2475 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 2476 if (ssthresh < 2) 2477 ssthresh = 2; 2478 ssthresh *= (tp->t_maxseg + 2479 #ifdef INET6 2480 (isipv6 ? sizeof (struct ip6_hdr) + 2481 sizeof (struct tcphdr) : 2482 #endif 2483 sizeof (struct tcpiphdr) 2484 #ifdef INET6 2485 ) 2486 #endif 2487 ); 2488 } else 2489 ssthresh = 0; 2490 metrics.rmx_ssthresh = ssthresh; 2491 2492 metrics.rmx_rtt = tp->t_srtt; 2493 metrics.rmx_rttvar = tp->t_rttvar; 2494 metrics.rmx_cwnd = tp->snd_cwnd; 2495 metrics.rmx_sendpipe = 0; 2496 metrics.rmx_recvpipe = 0; 2497 2498 tcp_hc_update(&inp->inp_inc, &metrics); 2499 } 2500 2501 refcount_release(&tp->t_fb->tfb_refcnt); 2502 } 2503 2504 /* 2505 * Attempt to close a TCP control block, marking it as dropped, and freeing 2506 * the socket if we hold the only reference. 2507 */ 2508 struct tcpcb * 2509 tcp_close(struct tcpcb *tp) 2510 { 2511 struct inpcb *inp = tptoinpcb(tp); 2512 struct socket *so = tptosocket(tp); 2513 2514 INP_WLOCK_ASSERT(inp); 2515 2516 #ifdef TCP_OFFLOAD 2517 if (tp->t_state == TCPS_LISTEN) 2518 tcp_offload_listen_stop(tp); 2519 #endif 2520 /* 2521 * This releases the TFO pending counter resource for TFO listen 2522 * sockets as well as passively-created TFO sockets that transition 2523 * from SYN_RECEIVED to CLOSED. 2524 */ 2525 if (tp->t_tfo_pending) { 2526 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 2527 tp->t_tfo_pending = NULL; 2528 } 2529 #ifdef TCPHPTS 2530 tcp_hpts_remove(tp); 2531 #endif 2532 in_pcbdrop(inp); 2533 TCPSTAT_INC(tcps_closed); 2534 if (tp->t_state != TCPS_CLOSED) 2535 tcp_state_change(tp, TCPS_CLOSED); 2536 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 2537 soisdisconnected(so); 2538 if (inp->inp_flags & INP_SOCKREF) { 2539 inp->inp_flags &= ~INP_SOCKREF; 2540 INP_WUNLOCK(inp); 2541 sorele(so); 2542 return (NULL); 2543 } 2544 return (tp); 2545 } 2546 2547 /* 2548 * Notify a tcp user of an asynchronous error; 2549 * store error as soft error, but wake up user 2550 * (for now, won't do anything until can select for soft error). 2551 * 2552 * Do not wake up user since there currently is no mechanism for 2553 * reporting soft errors (yet - a kqueue filter may be added). 2554 */ 2555 static struct inpcb * 2556 tcp_notify(struct inpcb *inp, int error) 2557 { 2558 struct tcpcb *tp; 2559 2560 INP_WLOCK_ASSERT(inp); 2561 2562 tp = intotcpcb(inp); 2563 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 2564 2565 /* 2566 * Ignore some errors if we are hooked up. 2567 * If connection hasn't completed, has retransmitted several times, 2568 * and receives a second error, give up now. This is better 2569 * than waiting a long time to establish a connection that 2570 * can never complete. 2571 */ 2572 if (tp->t_state == TCPS_ESTABLISHED && 2573 (error == EHOSTUNREACH || error == ENETUNREACH || 2574 error == EHOSTDOWN)) { 2575 if (inp->inp_route.ro_nh) { 2576 NH_FREE(inp->inp_route.ro_nh); 2577 inp->inp_route.ro_nh = (struct nhop_object *)NULL; 2578 } 2579 return (inp); 2580 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 2581 tp->t_softerror) { 2582 tp = tcp_drop(tp, error); 2583 if (tp != NULL) 2584 return (inp); 2585 else 2586 return (NULL); 2587 } else { 2588 tp->t_softerror = error; 2589 return (inp); 2590 } 2591 #if 0 2592 wakeup( &so->so_timeo); 2593 sorwakeup(so); 2594 sowwakeup(so); 2595 #endif 2596 } 2597 2598 static int 2599 tcp_pcblist(SYSCTL_HANDLER_ARGS) 2600 { 2601 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo, 2602 INPLOOKUP_RLOCKPCB); 2603 struct xinpgen xig; 2604 struct inpcb *inp; 2605 int error; 2606 2607 if (req->newptr != NULL) 2608 return (EPERM); 2609 2610 if (req->oldptr == NULL) { 2611 int n; 2612 2613 n = V_tcbinfo.ipi_count + 2614 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2615 n += imax(n / 8, 10); 2616 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 2617 return (0); 2618 } 2619 2620 if ((error = sysctl_wire_old_buffer(req, 0)) != 0) 2621 return (error); 2622 2623 bzero(&xig, sizeof(xig)); 2624 xig.xig_len = sizeof xig; 2625 xig.xig_count = V_tcbinfo.ipi_count + 2626 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2627 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2628 xig.xig_sogen = so_gencnt; 2629 error = SYSCTL_OUT(req, &xig, sizeof xig); 2630 if (error) 2631 return (error); 2632 2633 error = syncache_pcblist(req); 2634 if (error) 2635 return (error); 2636 2637 while ((inp = inp_next(&inpi)) != NULL) { 2638 if (inp->inp_gencnt <= xig.xig_gen && 2639 cr_canseeinpcb(req->td->td_ucred, inp) == 0) { 2640 struct xtcpcb xt; 2641 2642 tcp_inptoxtp(inp, &xt); 2643 error = SYSCTL_OUT(req, &xt, sizeof xt); 2644 if (error) { 2645 INP_RUNLOCK(inp); 2646 break; 2647 } else 2648 continue; 2649 } 2650 } 2651 2652 if (!error) { 2653 /* 2654 * Give the user an updated idea of our state. 2655 * If the generation differs from what we told 2656 * her before, she knows that something happened 2657 * while we were processing this request, and it 2658 * might be necessary to retry. 2659 */ 2660 xig.xig_gen = V_tcbinfo.ipi_gencnt; 2661 xig.xig_sogen = so_gencnt; 2662 xig.xig_count = V_tcbinfo.ipi_count + 2663 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 2664 error = SYSCTL_OUT(req, &xig, sizeof xig); 2665 } 2666 2667 return (error); 2668 } 2669 2670 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 2671 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, 2672 NULL, 0, tcp_pcblist, "S,xtcpcb", 2673 "List of active TCP connections"); 2674 2675 #ifdef INET 2676 static int 2677 tcp_getcred(SYSCTL_HANDLER_ARGS) 2678 { 2679 struct xucred xuc; 2680 struct sockaddr_in addrs[2]; 2681 struct epoch_tracker et; 2682 struct inpcb *inp; 2683 int error; 2684 2685 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2686 if (error) 2687 return (error); 2688 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2689 if (error) 2690 return (error); 2691 NET_EPOCH_ENTER(et); 2692 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 2693 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 2694 NET_EPOCH_EXIT(et); 2695 if (inp != NULL) { 2696 if (error == 0) 2697 error = cr_canseeinpcb(req->td->td_ucred, inp); 2698 if (error == 0) 2699 cru2x(inp->inp_cred, &xuc); 2700 INP_RUNLOCK(inp); 2701 } else 2702 error = ENOENT; 2703 if (error == 0) 2704 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2705 return (error); 2706 } 2707 2708 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 2709 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2710 0, 0, tcp_getcred, "S,xucred", 2711 "Get the xucred of a TCP connection"); 2712 #endif /* INET */ 2713 2714 #ifdef INET6 2715 static int 2716 tcp6_getcred(SYSCTL_HANDLER_ARGS) 2717 { 2718 struct epoch_tracker et; 2719 struct xucred xuc; 2720 struct sockaddr_in6 addrs[2]; 2721 struct inpcb *inp; 2722 int error; 2723 #ifdef INET 2724 int mapped = 0; 2725 #endif 2726 2727 error = priv_check(req->td, PRIV_NETINET_GETCRED); 2728 if (error) 2729 return (error); 2730 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 2731 if (error) 2732 return (error); 2733 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 2734 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 2735 return (error); 2736 } 2737 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 2738 #ifdef INET 2739 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 2740 mapped = 1; 2741 else 2742 #endif 2743 return (EINVAL); 2744 } 2745 2746 NET_EPOCH_ENTER(et); 2747 #ifdef INET 2748 if (mapped == 1) 2749 inp = in_pcblookup(&V_tcbinfo, 2750 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 2751 addrs[1].sin6_port, 2752 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 2753 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 2754 else 2755 #endif 2756 inp = in6_pcblookup(&V_tcbinfo, 2757 &addrs[1].sin6_addr, addrs[1].sin6_port, 2758 &addrs[0].sin6_addr, addrs[0].sin6_port, 2759 INPLOOKUP_RLOCKPCB, NULL); 2760 NET_EPOCH_EXIT(et); 2761 if (inp != NULL) { 2762 if (error == 0) 2763 error = cr_canseeinpcb(req->td->td_ucred, inp); 2764 if (error == 0) 2765 cru2x(inp->inp_cred, &xuc); 2766 INP_RUNLOCK(inp); 2767 } else 2768 error = ENOENT; 2769 if (error == 0) 2770 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 2771 return (error); 2772 } 2773 2774 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 2775 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT, 2776 0, 0, tcp6_getcred, "S,xucred", 2777 "Get the xucred of a TCP6 connection"); 2778 #endif /* INET6 */ 2779 2780 #ifdef INET 2781 /* Path MTU to try next when a fragmentation-needed message is received. */ 2782 static inline int 2783 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip) 2784 { 2785 int mtu = ntohs(icp->icmp_nextmtu); 2786 2787 /* If no alternative MTU was proposed, try the next smaller one. */ 2788 if (!mtu) 2789 mtu = ip_next_mtu(ntohs(ip->ip_len), 1); 2790 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr)) 2791 mtu = V_tcp_minmss + sizeof(struct tcpiphdr); 2792 2793 return (mtu); 2794 } 2795 2796 static void 2797 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port) 2798 { 2799 struct ip *ip; 2800 struct tcphdr *th; 2801 struct inpcb *inp; 2802 struct tcpcb *tp; 2803 struct inpcb *(*notify)(struct inpcb *, int); 2804 struct in_conninfo inc; 2805 tcp_seq icmp_tcp_seq; 2806 int errno, mtu; 2807 2808 errno = icmp_errmap(icp); 2809 switch (errno) { 2810 case 0: 2811 return; 2812 case EMSGSIZE: 2813 notify = tcp_mtudisc_notify; 2814 break; 2815 case ECONNREFUSED: 2816 if (V_icmp_may_rst) 2817 notify = tcp_drop_syn_sent; 2818 else 2819 notify = tcp_notify; 2820 break; 2821 case EHOSTUNREACH: 2822 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED) 2823 notify = tcp_drop_syn_sent; 2824 else 2825 notify = tcp_notify; 2826 break; 2827 default: 2828 notify = tcp_notify; 2829 } 2830 2831 ip = &icp->icmp_ip; 2832 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 2833 icmp_tcp_seq = th->th_seq; 2834 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src, 2835 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2836 if (inp != NULL) { 2837 tp = intotcpcb(inp); 2838 #ifdef TCP_OFFLOAD 2839 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 2840 /* 2841 * MTU discovery for offloaded connections. Let 2842 * the TOE driver verify seq# and process it. 2843 */ 2844 mtu = tcp_next_pmtu(icp, ip); 2845 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 2846 goto out; 2847 } 2848 #endif 2849 if (tp->t_port != port) 2850 goto out; 2851 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 2852 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 2853 if (errno == EMSGSIZE) { 2854 /* 2855 * MTU discovery: we got a needfrag and 2856 * will potentially try a lower MTU. 2857 */ 2858 mtu = tcp_next_pmtu(icp, ip); 2859 2860 /* 2861 * Only process the offered MTU if it 2862 * is smaller than the current one. 2863 */ 2864 if (mtu < tp->t_maxseg + 2865 sizeof(struct tcpiphdr)) { 2866 bzero(&inc, sizeof(inc)); 2867 inc.inc_faddr = ip->ip_dst; 2868 inc.inc_fibnum = 2869 inp->inp_inc.inc_fibnum; 2870 tcp_hc_updatemtu(&inc, mtu); 2871 inp = tcp_mtudisc(inp, mtu); 2872 } 2873 } else 2874 inp = (*notify)(inp, errno); 2875 } 2876 } else { 2877 bzero(&inc, sizeof(inc)); 2878 inc.inc_fport = th->th_dport; 2879 inc.inc_lport = th->th_sport; 2880 inc.inc_faddr = ip->ip_dst; 2881 inc.inc_laddr = ip->ip_src; 2882 syncache_unreach(&inc, icmp_tcp_seq, port); 2883 } 2884 out: 2885 if (inp != NULL) 2886 INP_WUNLOCK(inp); 2887 } 2888 2889 static void 2890 tcp_ctlinput(struct icmp *icmp) 2891 { 2892 tcp_ctlinput_with_port(icmp, htons(0)); 2893 } 2894 2895 static void 2896 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param) 2897 { 2898 /* Its a tunneled TCP over UDP icmp */ 2899 struct icmp *icmp = param.icmp; 2900 struct ip *outer_ip, *inner_ip; 2901 struct udphdr *udp; 2902 struct tcphdr *th, ttemp; 2903 int i_hlen, o_len; 2904 uint16_t port; 2905 2906 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip)); 2907 inner_ip = &icmp->icmp_ip; 2908 i_hlen = inner_ip->ip_hl << 2; 2909 o_len = ntohs(outer_ip->ip_len); 2910 if (o_len < 2911 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) { 2912 /* Not enough data present */ 2913 return; 2914 } 2915 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */ 2916 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen); 2917 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 2918 return; 2919 } 2920 port = udp->uh_dport; 2921 th = (struct tcphdr *)(udp + 1); 2922 memcpy(&ttemp, th, sizeof(struct tcphdr)); 2923 memcpy(udp, &ttemp, sizeof(struct tcphdr)); 2924 /* Now adjust down the size of the outer IP header */ 2925 o_len -= sizeof(struct udphdr); 2926 outer_ip->ip_len = htons(o_len); 2927 /* Now call in to the normal handling code */ 2928 tcp_ctlinput_with_port(icmp, port); 2929 } 2930 #endif /* INET */ 2931 2932 #ifdef INET6 2933 static inline int 2934 tcp6_next_pmtu(const struct icmp6_hdr *icmp6) 2935 { 2936 int mtu = ntohl(icmp6->icmp6_mtu); 2937 2938 /* 2939 * If no alternative MTU was proposed, or the proposed MTU was too 2940 * small, set to the min. 2941 */ 2942 if (mtu < IPV6_MMTU) 2943 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */ 2944 return (mtu); 2945 } 2946 2947 static void 2948 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port) 2949 { 2950 struct in6_addr *dst; 2951 struct inpcb *(*notify)(struct inpcb *, int); 2952 struct ip6_hdr *ip6; 2953 struct mbuf *m; 2954 struct inpcb *inp; 2955 struct tcpcb *tp; 2956 struct icmp6_hdr *icmp6; 2957 struct in_conninfo inc; 2958 struct tcp_ports { 2959 uint16_t th_sport; 2960 uint16_t th_dport; 2961 } t_ports; 2962 tcp_seq icmp_tcp_seq; 2963 unsigned int mtu; 2964 unsigned int off; 2965 int errno; 2966 2967 icmp6 = ip6cp->ip6c_icmp6; 2968 m = ip6cp->ip6c_m; 2969 ip6 = ip6cp->ip6c_ip6; 2970 off = ip6cp->ip6c_off; 2971 dst = &ip6cp->ip6c_finaldst->sin6_addr; 2972 2973 errno = icmp6_errmap(icmp6); 2974 switch (errno) { 2975 case 0: 2976 return; 2977 case EMSGSIZE: 2978 notify = tcp_mtudisc_notify; 2979 break; 2980 case ECONNREFUSED: 2981 if (V_icmp_may_rst) 2982 notify = tcp_drop_syn_sent; 2983 else 2984 notify = tcp_notify; 2985 break; 2986 case EHOSTUNREACH: 2987 /* 2988 * There are only four ICMPs that may reset connection: 2989 * - administratively prohibited 2990 * - port unreachable 2991 * - time exceeded in transit 2992 * - unknown next header 2993 */ 2994 if (V_icmp_may_rst && 2995 ((icmp6->icmp6_type == ICMP6_DST_UNREACH && 2996 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN || 2997 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) || 2998 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED && 2999 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) || 3000 (icmp6->icmp6_type == ICMP6_PARAM_PROB && 3001 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER))) 3002 notify = tcp_drop_syn_sent; 3003 else 3004 notify = tcp_notify; 3005 break; 3006 default: 3007 notify = tcp_notify; 3008 } 3009 3010 /* Check if we can safely get the ports from the tcp hdr */ 3011 if (m == NULL || 3012 (m->m_pkthdr.len < 3013 (int32_t) (off + sizeof(struct tcp_ports)))) { 3014 return; 3015 } 3016 bzero(&t_ports, sizeof(struct tcp_ports)); 3017 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports); 3018 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport, 3019 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL); 3020 off += sizeof(struct tcp_ports); 3021 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) { 3022 goto out; 3023 } 3024 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq); 3025 if (inp != NULL) { 3026 tp = intotcpcb(inp); 3027 #ifdef TCP_OFFLOAD 3028 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) { 3029 /* MTU discovery for offloaded connections. */ 3030 mtu = tcp6_next_pmtu(icmp6); 3031 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu); 3032 goto out; 3033 } 3034 #endif 3035 if (tp->t_port != port) 3036 goto out; 3037 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) && 3038 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) { 3039 if (errno == EMSGSIZE) { 3040 /* 3041 * MTU discovery: 3042 * If we got a needfrag set the MTU 3043 * in the route to the suggested new 3044 * value (if given) and then notify. 3045 */ 3046 mtu = tcp6_next_pmtu(icmp6); 3047 3048 bzero(&inc, sizeof(inc)); 3049 inc.inc_fibnum = M_GETFIB(m); 3050 inc.inc_flags |= INC_ISIPV6; 3051 inc.inc6_faddr = *dst; 3052 if (in6_setscope(&inc.inc6_faddr, 3053 m->m_pkthdr.rcvif, NULL)) 3054 goto out; 3055 /* 3056 * Only process the offered MTU if it 3057 * is smaller than the current one. 3058 */ 3059 if (mtu < tp->t_maxseg + 3060 sizeof (struct tcphdr) + 3061 sizeof (struct ip6_hdr)) { 3062 tcp_hc_updatemtu(&inc, mtu); 3063 tcp_mtudisc(inp, mtu); 3064 ICMP6STAT_INC(icp6s_pmtuchg); 3065 } 3066 } else 3067 inp = (*notify)(inp, errno); 3068 } 3069 } else { 3070 bzero(&inc, sizeof(inc)); 3071 inc.inc_fibnum = M_GETFIB(m); 3072 inc.inc_flags |= INC_ISIPV6; 3073 inc.inc_fport = t_ports.th_dport; 3074 inc.inc_lport = t_ports.th_sport; 3075 inc.inc6_faddr = *dst; 3076 inc.inc6_laddr = ip6->ip6_src; 3077 syncache_unreach(&inc, icmp_tcp_seq, port); 3078 } 3079 out: 3080 if (inp != NULL) 3081 INP_WUNLOCK(inp); 3082 } 3083 3084 static void 3085 tcp6_ctlinput(struct ip6ctlparam *ctl) 3086 { 3087 tcp6_ctlinput_with_port(ctl, htons(0)); 3088 } 3089 3090 static void 3091 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param) 3092 { 3093 struct ip6ctlparam *ip6cp = param.ip6cp; 3094 struct mbuf *m; 3095 struct udphdr *udp; 3096 uint16_t port; 3097 3098 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL); 3099 if (m == NULL) { 3100 return; 3101 } 3102 udp = mtod(m, struct udphdr *); 3103 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) { 3104 return; 3105 } 3106 port = udp->uh_dport; 3107 m_adj(m, sizeof(struct udphdr)); 3108 if ((m->m_flags & M_PKTHDR) == 0) { 3109 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr); 3110 } 3111 /* Now call in to the normal handling code */ 3112 tcp6_ctlinput_with_port(ip6cp, port); 3113 } 3114 3115 #endif /* INET6 */ 3116 3117 static uint32_t 3118 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len) 3119 { 3120 SIPHASH_CTX ctx; 3121 uint32_t hash[2]; 3122 3123 KASSERT(len >= SIPHASH_KEY_LENGTH, 3124 ("%s: keylen %u too short ", __func__, len)); 3125 SipHash24_Init(&ctx); 3126 SipHash_SetKey(&ctx, (uint8_t *)key); 3127 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t)); 3128 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t)); 3129 switch (inc->inc_flags & INC_ISIPV6) { 3130 #ifdef INET 3131 case 0: 3132 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr)); 3133 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr)); 3134 break; 3135 #endif 3136 #ifdef INET6 3137 case INC_ISIPV6: 3138 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr)); 3139 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr)); 3140 break; 3141 #endif 3142 } 3143 SipHash_Final((uint8_t *)hash, &ctx); 3144 3145 return (hash[0] ^ hash[1]); 3146 } 3147 3148 uint32_t 3149 tcp_new_ts_offset(struct in_conninfo *inc) 3150 { 3151 struct in_conninfo inc_store, *local_inc; 3152 3153 if (!V_tcp_ts_offset_per_conn) { 3154 memcpy(&inc_store, inc, sizeof(struct in_conninfo)); 3155 inc_store.inc_lport = 0; 3156 inc_store.inc_fport = 0; 3157 local_inc = &inc_store; 3158 } else { 3159 local_inc = inc; 3160 } 3161 return (tcp_keyed_hash(local_inc, V_ts_offset_secret, 3162 sizeof(V_ts_offset_secret))); 3163 } 3164 3165 /* 3166 * Following is where TCP initial sequence number generation occurs. 3167 * 3168 * There are two places where we must use initial sequence numbers: 3169 * 1. In SYN-ACK packets. 3170 * 2. In SYN packets. 3171 * 3172 * All ISNs for SYN-ACK packets are generated by the syncache. See 3173 * tcp_syncache.c for details. 3174 * 3175 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 3176 * depends on this property. In addition, these ISNs should be 3177 * unguessable so as to prevent connection hijacking. To satisfy 3178 * the requirements of this situation, the algorithm outlined in 3179 * RFC 1948 is used, with only small modifications. 3180 * 3181 * Implementation details: 3182 * 3183 * Time is based off the system timer, and is corrected so that it 3184 * increases by one megabyte per second. This allows for proper 3185 * recycling on high speed LANs while still leaving over an hour 3186 * before rollover. 3187 * 3188 * As reading the *exact* system time is too expensive to be done 3189 * whenever setting up a TCP connection, we increment the time 3190 * offset in two ways. First, a small random positive increment 3191 * is added to isn_offset for each connection that is set up. 3192 * Second, the function tcp_isn_tick fires once per clock tick 3193 * and increments isn_offset as necessary so that sequence numbers 3194 * are incremented at approximately ISN_BYTES_PER_SECOND. The 3195 * random positive increments serve only to ensure that the same 3196 * exact sequence number is never sent out twice (as could otherwise 3197 * happen when a port is recycled in less than the system tick 3198 * interval.) 3199 * 3200 * net.inet.tcp.isn_reseed_interval controls the number of seconds 3201 * between seeding of isn_secret. This is normally set to zero, 3202 * as reseeding should not be necessary. 3203 * 3204 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 3205 * isn_offset_old, and isn_ctx is performed using the ISN lock. In 3206 * general, this means holding an exclusive (write) lock. 3207 */ 3208 3209 #define ISN_BYTES_PER_SECOND 1048576 3210 #define ISN_STATIC_INCREMENT 4096 3211 #define ISN_RANDOM_INCREMENT (4096 - 1) 3212 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH 3213 3214 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]); 3215 VNET_DEFINE_STATIC(int, isn_last); 3216 VNET_DEFINE_STATIC(int, isn_last_reseed); 3217 VNET_DEFINE_STATIC(u_int32_t, isn_offset); 3218 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old); 3219 3220 #define V_isn_secret VNET(isn_secret) 3221 #define V_isn_last VNET(isn_last) 3222 #define V_isn_last_reseed VNET(isn_last_reseed) 3223 #define V_isn_offset VNET(isn_offset) 3224 #define V_isn_offset_old VNET(isn_offset_old) 3225 3226 tcp_seq 3227 tcp_new_isn(struct in_conninfo *inc) 3228 { 3229 tcp_seq new_isn; 3230 u_int32_t projected_offset; 3231 3232 ISN_LOCK(); 3233 /* Seed if this is the first use, reseed if requested. */ 3234 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 3235 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 3236 < (u_int)ticks))) { 3237 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0); 3238 V_isn_last_reseed = ticks; 3239 } 3240 3241 /* Compute the hash and return the ISN. */ 3242 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret, 3243 sizeof(V_isn_secret)); 3244 V_isn_offset += ISN_STATIC_INCREMENT + 3245 (arc4random() & ISN_RANDOM_INCREMENT); 3246 if (ticks != V_isn_last) { 3247 projected_offset = V_isn_offset_old + 3248 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 3249 if (SEQ_GT(projected_offset, V_isn_offset)) 3250 V_isn_offset = projected_offset; 3251 V_isn_offset_old = V_isn_offset; 3252 V_isn_last = ticks; 3253 } 3254 new_isn += V_isn_offset; 3255 ISN_UNLOCK(); 3256 return (new_isn); 3257 } 3258 3259 /* 3260 * When a specific ICMP unreachable message is received and the 3261 * connection state is SYN-SENT, drop the connection. This behavior 3262 * is controlled by the icmp_may_rst sysctl. 3263 */ 3264 static struct inpcb * 3265 tcp_drop_syn_sent(struct inpcb *inp, int errno) 3266 { 3267 struct tcpcb *tp; 3268 3269 NET_EPOCH_ASSERT(); 3270 INP_WLOCK_ASSERT(inp); 3271 3272 tp = intotcpcb(inp); 3273 if (tp->t_state != TCPS_SYN_SENT) 3274 return (inp); 3275 3276 if (IS_FASTOPEN(tp->t_flags)) 3277 tcp_fastopen_disable_path(tp); 3278 3279 tp = tcp_drop(tp, errno); 3280 if (tp != NULL) 3281 return (inp); 3282 else 3283 return (NULL); 3284 } 3285 3286 /* 3287 * When `need fragmentation' ICMP is received, update our idea of the MSS 3288 * based on the new value. Also nudge TCP to send something, since we 3289 * know the packet we just sent was dropped. 3290 * This duplicates some code in the tcp_mss() function in tcp_input.c. 3291 */ 3292 static struct inpcb * 3293 tcp_mtudisc_notify(struct inpcb *inp, int error) 3294 { 3295 3296 return (tcp_mtudisc(inp, -1)); 3297 } 3298 3299 static struct inpcb * 3300 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 3301 { 3302 struct tcpcb *tp; 3303 struct socket *so; 3304 3305 INP_WLOCK_ASSERT(inp); 3306 3307 tp = intotcpcb(inp); 3308 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 3309 3310 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 3311 3312 so = inp->inp_socket; 3313 SOCKBUF_LOCK(&so->so_snd); 3314 /* If the mss is larger than the socket buffer, decrease the mss. */ 3315 if (so->so_snd.sb_hiwat < tp->t_maxseg) 3316 tp->t_maxseg = so->so_snd.sb_hiwat; 3317 SOCKBUF_UNLOCK(&so->so_snd); 3318 3319 TCPSTAT_INC(tcps_mturesent); 3320 tp->t_rtttime = 0; 3321 tp->snd_nxt = tp->snd_una; 3322 tcp_free_sackholes(tp); 3323 tp->snd_recover = tp->snd_max; 3324 if (tp->t_flags & TF_SACK_PERMIT) 3325 EXIT_FASTRECOVERY(tp->t_flags); 3326 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) { 3327 /* 3328 * Conceptually the snd_nxt setting 3329 * and freeing sack holes should 3330 * be done by the default stacks 3331 * own tfb_tcp_mtu_chg(). 3332 */ 3333 tp->t_fb->tfb_tcp_mtu_chg(tp); 3334 } 3335 if (tcp_output(tp) < 0) 3336 return (NULL); 3337 else 3338 return (inp); 3339 } 3340 3341 #ifdef INET 3342 /* 3343 * Look-up the routing entry to the peer of this inpcb. If no route 3344 * is found and it cannot be allocated, then return 0. This routine 3345 * is called by TCP routines that access the rmx structure and by 3346 * tcp_mss_update to get the peer/interface MTU. 3347 */ 3348 uint32_t 3349 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 3350 { 3351 struct nhop_object *nh; 3352 struct ifnet *ifp; 3353 uint32_t maxmtu = 0; 3354 3355 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 3356 3357 if (inc->inc_faddr.s_addr != INADDR_ANY) { 3358 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0); 3359 if (nh == NULL) 3360 return (0); 3361 3362 ifp = nh->nh_ifp; 3363 maxmtu = nh->nh_mtu; 3364 3365 /* Report additional interface capabilities. */ 3366 if (cap != NULL) { 3367 if (ifp->if_capenable & IFCAP_TSO4 && 3368 ifp->if_hwassist & CSUM_TSO) { 3369 cap->ifcap |= CSUM_TSO; 3370 cap->tsomax = ifp->if_hw_tsomax; 3371 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3372 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3373 } 3374 } 3375 } 3376 return (maxmtu); 3377 } 3378 #endif /* INET */ 3379 3380 #ifdef INET6 3381 uint32_t 3382 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 3383 { 3384 struct nhop_object *nh; 3385 struct in6_addr dst6; 3386 uint32_t scopeid; 3387 struct ifnet *ifp; 3388 uint32_t maxmtu = 0; 3389 3390 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 3391 3392 if (inc->inc_flags & INC_IPV6MINMTU) 3393 return (IPV6_MMTU); 3394 3395 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 3396 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 3397 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0); 3398 if (nh == NULL) 3399 return (0); 3400 3401 ifp = nh->nh_ifp; 3402 maxmtu = nh->nh_mtu; 3403 3404 /* Report additional interface capabilities. */ 3405 if (cap != NULL) { 3406 if (ifp->if_capenable & IFCAP_TSO6 && 3407 ifp->if_hwassist & CSUM_TSO) { 3408 cap->ifcap |= CSUM_TSO; 3409 cap->tsomax = ifp->if_hw_tsomax; 3410 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 3411 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 3412 } 3413 } 3414 } 3415 3416 return (maxmtu); 3417 } 3418 3419 /* 3420 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack. 3421 * 3422 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag. 3423 * The right place to do that is ip6_setpktopt() that has just been 3424 * executed. By the way it just filled ip6po_minmtu for us. 3425 */ 3426 void 3427 tcp6_use_min_mtu(struct tcpcb *tp) 3428 { 3429 struct inpcb *inp = tptoinpcb(tp); 3430 3431 INP_WLOCK_ASSERT(inp); 3432 /* 3433 * In case of the IPV6_USE_MIN_MTU socket 3434 * option, the INC_IPV6MINMTU flag to announce 3435 * a corresponding MSS during the initial 3436 * handshake. If the TCP connection is not in 3437 * the front states, just reduce the MSS being 3438 * used. This avoids the sending of TCP 3439 * segments which will be fragmented at the 3440 * IPv6 layer. 3441 */ 3442 inp->inp_inc.inc_flags |= INC_IPV6MINMTU; 3443 if ((tp->t_state >= TCPS_SYN_SENT) && 3444 (inp->inp_inc.inc_flags & INC_ISIPV6)) { 3445 struct ip6_pktopts *opt; 3446 3447 opt = inp->in6p_outputopts; 3448 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && 3449 tp->t_maxseg > TCP6_MSS) 3450 tp->t_maxseg = TCP6_MSS; 3451 } 3452 } 3453 #endif /* INET6 */ 3454 3455 /* 3456 * Calculate effective SMSS per RFC5681 definition for a given TCP 3457 * connection at its current state, taking into account SACK and etc. 3458 */ 3459 u_int 3460 tcp_maxseg(const struct tcpcb *tp) 3461 { 3462 u_int optlen; 3463 3464 if (tp->t_flags & TF_NOOPT) 3465 return (tp->t_maxseg); 3466 3467 /* 3468 * Here we have a simplified code from tcp_addoptions(), 3469 * without a proper loop, and having most of paddings hardcoded. 3470 * We might make mistakes with padding here in some edge cases, 3471 * but this is harmless, since result of tcp_maxseg() is used 3472 * only in cwnd and ssthresh estimations. 3473 */ 3474 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3475 if (tp->t_flags & TF_RCVD_TSTMP) 3476 optlen = TCPOLEN_TSTAMP_APPA; 3477 else 3478 optlen = 0; 3479 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3480 if (tp->t_flags & TF_SIGNATURE) 3481 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3482 #endif 3483 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 3484 optlen += TCPOLEN_SACKHDR; 3485 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 3486 optlen = PADTCPOLEN(optlen); 3487 } 3488 } else { 3489 if (tp->t_flags & TF_REQ_TSTMP) 3490 optlen = TCPOLEN_TSTAMP_APPA; 3491 else 3492 optlen = PADTCPOLEN(TCPOLEN_MAXSEG); 3493 if (tp->t_flags & TF_REQ_SCALE) 3494 optlen += PADTCPOLEN(TCPOLEN_WINDOW); 3495 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3496 if (tp->t_flags & TF_SIGNATURE) 3497 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE); 3498 #endif 3499 if (tp->t_flags & TF_SACK_PERMIT) 3500 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED); 3501 } 3502 #undef PAD 3503 optlen = min(optlen, TCP_MAXOLEN); 3504 return (tp->t_maxseg - optlen); 3505 } 3506 3507 3508 u_int 3509 tcp_fixed_maxseg(const struct tcpcb *tp) 3510 { 3511 int optlen; 3512 3513 if (tp->t_flags & TF_NOOPT) 3514 return (tp->t_maxseg); 3515 3516 /* 3517 * Here we have a simplified code from tcp_addoptions(), 3518 * without a proper loop, and having most of paddings hardcoded. 3519 * We only consider fixed options that we would send every 3520 * time I.e. SACK is not considered. This is important 3521 * for cc modules to figure out what the modulo of the 3522 * cwnd should be. 3523 */ 3524 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 3525 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 3526 if (tp->t_flags & TF_RCVD_TSTMP) 3527 optlen = TCPOLEN_TSTAMP_APPA; 3528 else 3529 optlen = 0; 3530 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3531 if (tp->t_flags & TF_SIGNATURE) 3532 optlen += PAD(TCPOLEN_SIGNATURE); 3533 #endif 3534 } else { 3535 if (tp->t_flags & TF_REQ_TSTMP) 3536 optlen = TCPOLEN_TSTAMP_APPA; 3537 else 3538 optlen = PAD(TCPOLEN_MAXSEG); 3539 if (tp->t_flags & TF_REQ_SCALE) 3540 optlen += PAD(TCPOLEN_WINDOW); 3541 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 3542 if (tp->t_flags & TF_SIGNATURE) 3543 optlen += PAD(TCPOLEN_SIGNATURE); 3544 #endif 3545 if (tp->t_flags & TF_SACK_PERMIT) 3546 optlen += PAD(TCPOLEN_SACK_PERMITTED); 3547 } 3548 #undef PAD 3549 optlen = min(optlen, TCP_MAXOLEN); 3550 return (tp->t_maxseg - optlen); 3551 } 3552 3553 3554 3555 static int 3556 sysctl_drop(SYSCTL_HANDLER_ARGS) 3557 { 3558 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3559 struct sockaddr_storage addrs[2]; 3560 struct inpcb *inp; 3561 struct tcpcb *tp; 3562 #ifdef INET 3563 struct sockaddr_in *fin = NULL, *lin = NULL; 3564 #endif 3565 struct epoch_tracker et; 3566 #ifdef INET6 3567 struct sockaddr_in6 *fin6, *lin6; 3568 #endif 3569 int error; 3570 3571 inp = NULL; 3572 #ifdef INET6 3573 fin6 = lin6 = NULL; 3574 #endif 3575 error = 0; 3576 3577 if (req->oldptr != NULL || req->oldlen != 0) 3578 return (EINVAL); 3579 if (req->newptr == NULL) 3580 return (EPERM); 3581 if (req->newlen < sizeof(addrs)) 3582 return (ENOMEM); 3583 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3584 if (error) 3585 return (error); 3586 3587 switch (addrs[0].ss_family) { 3588 #ifdef INET6 3589 case AF_INET6: 3590 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3591 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3592 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3593 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3594 return (EINVAL); 3595 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3596 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3597 return (EINVAL); 3598 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3599 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3600 #ifdef INET 3601 fin = (struct sockaddr_in *)&addrs[0]; 3602 lin = (struct sockaddr_in *)&addrs[1]; 3603 #endif 3604 break; 3605 } 3606 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3607 if (error) 3608 return (error); 3609 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3610 if (error) 3611 return (error); 3612 break; 3613 #endif 3614 #ifdef INET 3615 case AF_INET: 3616 fin = (struct sockaddr_in *)&addrs[0]; 3617 lin = (struct sockaddr_in *)&addrs[1]; 3618 if (fin->sin_len != sizeof(struct sockaddr_in) || 3619 lin->sin_len != sizeof(struct sockaddr_in)) 3620 return (EINVAL); 3621 break; 3622 #endif 3623 default: 3624 return (EINVAL); 3625 } 3626 NET_EPOCH_ENTER(et); 3627 switch (addrs[0].ss_family) { 3628 #ifdef INET6 3629 case AF_INET6: 3630 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3631 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3632 INPLOOKUP_WLOCKPCB, NULL); 3633 break; 3634 #endif 3635 #ifdef INET 3636 case AF_INET: 3637 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3638 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3639 break; 3640 #endif 3641 } 3642 if (inp != NULL) { 3643 if (!SOLISTENING(inp->inp_socket)) { 3644 tp = intotcpcb(inp); 3645 tp = tcp_drop(tp, ECONNABORTED); 3646 if (tp != NULL) 3647 INP_WUNLOCK(inp); 3648 } else 3649 INP_WUNLOCK(inp); 3650 } else 3651 error = ESRCH; 3652 NET_EPOCH_EXIT(et); 3653 return (error); 3654 } 3655 3656 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 3657 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3658 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "", 3659 "Drop TCP connection"); 3660 3661 static int 3662 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS) 3663 { 3664 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo, 3665 &tcp_ctloutput_set)); 3666 } 3667 3668 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt, 3669 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3670 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "", 3671 "Set socket option for TCP endpoint"); 3672 3673 #ifdef KERN_TLS 3674 static int 3675 sysctl_switch_tls(SYSCTL_HANDLER_ARGS) 3676 { 3677 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 3678 struct sockaddr_storage addrs[2]; 3679 struct inpcb *inp; 3680 #ifdef INET 3681 struct sockaddr_in *fin = NULL, *lin = NULL; 3682 #endif 3683 struct epoch_tracker et; 3684 #ifdef INET6 3685 struct sockaddr_in6 *fin6, *lin6; 3686 #endif 3687 int error; 3688 3689 inp = NULL; 3690 #ifdef INET6 3691 fin6 = lin6 = NULL; 3692 #endif 3693 error = 0; 3694 3695 if (req->oldptr != NULL || req->oldlen != 0) 3696 return (EINVAL); 3697 if (req->newptr == NULL) 3698 return (EPERM); 3699 if (req->newlen < sizeof(addrs)) 3700 return (ENOMEM); 3701 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 3702 if (error) 3703 return (error); 3704 3705 switch (addrs[0].ss_family) { 3706 #ifdef INET6 3707 case AF_INET6: 3708 fin6 = (struct sockaddr_in6 *)&addrs[0]; 3709 lin6 = (struct sockaddr_in6 *)&addrs[1]; 3710 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 3711 lin6->sin6_len != sizeof(struct sockaddr_in6)) 3712 return (EINVAL); 3713 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 3714 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 3715 return (EINVAL); 3716 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 3717 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 3718 #ifdef INET 3719 fin = (struct sockaddr_in *)&addrs[0]; 3720 lin = (struct sockaddr_in *)&addrs[1]; 3721 #endif 3722 break; 3723 } 3724 error = sa6_embedscope(fin6, V_ip6_use_defzone); 3725 if (error) 3726 return (error); 3727 error = sa6_embedscope(lin6, V_ip6_use_defzone); 3728 if (error) 3729 return (error); 3730 break; 3731 #endif 3732 #ifdef INET 3733 case AF_INET: 3734 fin = (struct sockaddr_in *)&addrs[0]; 3735 lin = (struct sockaddr_in *)&addrs[1]; 3736 if (fin->sin_len != sizeof(struct sockaddr_in) || 3737 lin->sin_len != sizeof(struct sockaddr_in)) 3738 return (EINVAL); 3739 break; 3740 #endif 3741 default: 3742 return (EINVAL); 3743 } 3744 NET_EPOCH_ENTER(et); 3745 switch (addrs[0].ss_family) { 3746 #ifdef INET6 3747 case AF_INET6: 3748 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 3749 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 3750 INPLOOKUP_WLOCKPCB, NULL); 3751 break; 3752 #endif 3753 #ifdef INET 3754 case AF_INET: 3755 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 3756 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 3757 break; 3758 #endif 3759 } 3760 NET_EPOCH_EXIT(et); 3761 if (inp != NULL) { 3762 struct socket *so; 3763 3764 so = inp->inp_socket; 3765 soref(so); 3766 error = ktls_set_tx_mode(so, 3767 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET); 3768 INP_WUNLOCK(inp); 3769 sorele(so); 3770 } else 3771 error = ESRCH; 3772 return (error); 3773 } 3774 3775 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls, 3776 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3777 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "", 3778 "Switch TCP connection to SW TLS"); 3779 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls, 3780 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP | 3781 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "", 3782 "Switch TCP connection to ifnet TLS"); 3783 #endif 3784 3785 /* 3786 * Generate a standardized TCP log line for use throughout the 3787 * tcp subsystem. Memory allocation is done with M_NOWAIT to 3788 * allow use in the interrupt context. 3789 * 3790 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 3791 * NB: The function may return NULL if memory allocation failed. 3792 * 3793 * Due to header inclusion and ordering limitations the struct ip 3794 * and ip6_hdr pointers have to be passed as void pointers. 3795 */ 3796 char * 3797 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3798 const void *ip6hdr) 3799 { 3800 3801 /* Is logging enabled? */ 3802 if (V_tcp_log_in_vain == 0) 3803 return (NULL); 3804 3805 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3806 } 3807 3808 char * 3809 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3810 const void *ip6hdr) 3811 { 3812 3813 /* Is logging enabled? */ 3814 if (tcp_log_debug == 0) 3815 return (NULL); 3816 3817 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 3818 } 3819 3820 static char * 3821 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr, 3822 const void *ip6hdr) 3823 { 3824 char *s, *sp; 3825 size_t size; 3826 #ifdef INET 3827 const struct ip *ip = (const struct ip *)ip4hdr; 3828 #endif 3829 #ifdef INET6 3830 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr; 3831 #endif /* INET6 */ 3832 3833 /* 3834 * The log line looks like this: 3835 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 3836 */ 3837 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 3838 sizeof(PRINT_TH_FLAGS) + 1 + 3839 #ifdef INET6 3840 2 * INET6_ADDRSTRLEN; 3841 #else 3842 2 * INET_ADDRSTRLEN; 3843 #endif /* INET6 */ 3844 3845 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 3846 if (s == NULL) 3847 return (NULL); 3848 3849 strcat(s, "TCP: ["); 3850 sp = s + strlen(s); 3851 3852 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 3853 inet_ntoa_r(inc->inc_faddr, sp); 3854 sp = s + strlen(s); 3855 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3856 sp = s + strlen(s); 3857 inet_ntoa_r(inc->inc_laddr, sp); 3858 sp = s + strlen(s); 3859 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3860 #ifdef INET6 3861 } else if (inc) { 3862 ip6_sprintf(sp, &inc->inc6_faddr); 3863 sp = s + strlen(s); 3864 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 3865 sp = s + strlen(s); 3866 ip6_sprintf(sp, &inc->inc6_laddr); 3867 sp = s + strlen(s); 3868 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 3869 } else if (ip6 && th) { 3870 ip6_sprintf(sp, &ip6->ip6_src); 3871 sp = s + strlen(s); 3872 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3873 sp = s + strlen(s); 3874 ip6_sprintf(sp, &ip6->ip6_dst); 3875 sp = s + strlen(s); 3876 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3877 #endif /* INET6 */ 3878 #ifdef INET 3879 } else if (ip && th) { 3880 inet_ntoa_r(ip->ip_src, sp); 3881 sp = s + strlen(s); 3882 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 3883 sp = s + strlen(s); 3884 inet_ntoa_r(ip->ip_dst, sp); 3885 sp = s + strlen(s); 3886 sprintf(sp, "]:%i", ntohs(th->th_dport)); 3887 #endif /* INET */ 3888 } else { 3889 free(s, M_TCPLOG); 3890 return (NULL); 3891 } 3892 sp = s + strlen(s); 3893 if (th) 3894 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS); 3895 if (*(s + size - 1) != '\0') 3896 panic("%s: string too long", __func__); 3897 return (s); 3898 } 3899 3900 /* 3901 * A subroutine which makes it easy to track TCP state changes with DTrace. 3902 * This function shouldn't be called for t_state initializations that don't 3903 * correspond to actual TCP state transitions. 3904 */ 3905 void 3906 tcp_state_change(struct tcpcb *tp, int newstate) 3907 { 3908 #if defined(KDTRACE_HOOKS) 3909 int pstate = tp->t_state; 3910 #endif 3911 3912 TCPSTATES_DEC(tp->t_state); 3913 TCPSTATES_INC(newstate); 3914 tp->t_state = newstate; 3915 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 3916 } 3917 3918 /* 3919 * Create an external-format (``xtcpcb'') structure using the information in 3920 * the kernel-format tcpcb structure pointed to by tp. This is done to 3921 * reduce the spew of irrelevant information over this interface, to isolate 3922 * user code from changes in the kernel structure, and potentially to provide 3923 * information-hiding if we decide that some of this information should be 3924 * hidden from users. 3925 */ 3926 void 3927 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 3928 { 3929 struct tcpcb *tp = intotcpcb(inp); 3930 sbintime_t now; 3931 3932 bzero(xt, sizeof(*xt)); 3933 xt->t_state = tp->t_state; 3934 xt->t_logstate = tcp_get_bblog_state(tp); 3935 xt->t_flags = tp->t_flags; 3936 xt->t_sndzerowin = tp->t_sndzerowin; 3937 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 3938 xt->t_rcvoopack = tp->t_rcvoopack; 3939 xt->t_rcv_wnd = tp->rcv_wnd; 3940 xt->t_snd_wnd = tp->snd_wnd; 3941 xt->t_snd_cwnd = tp->snd_cwnd; 3942 xt->t_snd_ssthresh = tp->snd_ssthresh; 3943 xt->t_dsack_bytes = tp->t_dsack_bytes; 3944 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes; 3945 xt->t_dsack_pack = tp->t_dsack_pack; 3946 xt->t_maxseg = tp->t_maxseg; 3947 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 + 3948 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0; 3949 3950 now = getsbinuptime(); 3951 #define COPYTIMER(which,where) do { \ 3952 if (tp->t_timers[which] != SBT_MAX) \ 3953 xt->where = (tp->t_timers[which] - now) / SBT_1MS; \ 3954 else \ 3955 xt->where = 0; \ 3956 } while (0) 3957 COPYTIMER(TT_DELACK, tt_delack); 3958 COPYTIMER(TT_REXMT, tt_rexmt); 3959 COPYTIMER(TT_PERSIST, tt_persist); 3960 COPYTIMER(TT_KEEP, tt_keep); 3961 COPYTIMER(TT_2MSL, tt_2msl); 3962 #undef COPYTIMER 3963 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 3964 3965 xt->xt_encaps_port = tp->t_port; 3966 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 3967 TCP_FUNCTION_NAME_LEN_MAX); 3968 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX); 3969 #ifdef TCP_BLACKBOX 3970 (void)tcp_log_get_id(tp, xt->xt_logid); 3971 #endif 3972 3973 xt->xt_len = sizeof(struct xtcpcb); 3974 in_pcbtoxinpcb(inp, &xt->xt_inp); 3975 /* 3976 * TCP doesn't use inp_ppcb pointer, we embed inpcb into tcpcb. 3977 * Fixup the pointer that in_pcbtoxinpcb() has set. When printing 3978 * TCP netstat(1) used to use this pointer, so this fixup needs to 3979 * stay for stable/14. 3980 */ 3981 xt->xt_inp.inp_ppcb = (uintptr_t)tp; 3982 } 3983 3984 void 3985 tcp_log_end_status(struct tcpcb *tp, uint8_t status) 3986 { 3987 uint32_t bit, i; 3988 3989 if ((tp == NULL) || 3990 (status > TCP_EI_STATUS_MAX_VALUE) || 3991 (status == 0)) { 3992 /* Invalid */ 3993 return; 3994 } 3995 if (status > (sizeof(uint32_t) * 8)) { 3996 /* Should this be a KASSERT? */ 3997 return; 3998 } 3999 bit = 1U << (status - 1); 4000 if (bit & tp->t_end_info_status) { 4001 /* already logged */ 4002 return; 4003 } 4004 for (i = 0; i < TCP_END_BYTE_INFO; i++) { 4005 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) { 4006 tp->t_end_info_bytes[i] = status; 4007 tp->t_end_info_status |= bit; 4008 break; 4009 } 4010 } 4011 } 4012 4013 int 4014 tcp_can_enable_pacing(void) 4015 { 4016 4017 if ((tcp_pacing_limit == -1) || 4018 (tcp_pacing_limit > number_of_tcp_connections_pacing)) { 4019 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1); 4020 shadow_num_connections = number_of_tcp_connections_pacing; 4021 return (1); 4022 } else { 4023 counter_u64_add(tcp_pacing_failures, 1); 4024 return (0); 4025 } 4026 } 4027 4028 static uint8_t tcp_pacing_warning = 0; 4029 4030 void 4031 tcp_decrement_paced_conn(void) 4032 { 4033 uint32_t ret; 4034 4035 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1); 4036 shadow_num_connections = number_of_tcp_connections_pacing; 4037 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?")); 4038 if (ret == 0) { 4039 if (tcp_pacing_limit != -1) { 4040 printf("Warning all pacing is now disabled, count decrements invalidly!\n"); 4041 tcp_pacing_limit = 0; 4042 } else if (tcp_pacing_warning == 0) { 4043 printf("Warning pacing count is invalid, invalid decrement\n"); 4044 tcp_pacing_warning = 1; 4045 } 4046 } 4047 } 4048 4049 static void 4050 tcp_default_switch_failed(struct tcpcb *tp) 4051 { 4052 /* 4053 * If a switch fails we only need to 4054 * care about two things: 4055 * a) The t_flags2 4056 * and 4057 * b) The timer granularity. 4058 * Timeouts, at least for now, don't use the 4059 * old callout system in the other stacks so 4060 * those are hopefully safe. 4061 */ 4062 tcp_lro_features_off(tp); 4063 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS); 4064 } 4065 4066 #ifdef TCP_ACCOUNTING 4067 int 4068 tcp_do_ack_accounting(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t tiwin, int mss) 4069 { 4070 if (SEQ_LT(th->th_ack, tp->snd_una)) { 4071 /* Do we have a SACK? */ 4072 if (to->to_flags & TOF_SACK) { 4073 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4074 tp->tcp_cnt_counters[ACK_SACK]++; 4075 } 4076 return (ACK_SACK); 4077 } else { 4078 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4079 tp->tcp_cnt_counters[ACK_BEHIND]++; 4080 } 4081 return (ACK_BEHIND); 4082 } 4083 } else if (th->th_ack == tp->snd_una) { 4084 /* Do we have a SACK? */ 4085 if (to->to_flags & TOF_SACK) { 4086 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4087 tp->tcp_cnt_counters[ACK_SACK]++; 4088 } 4089 return (ACK_SACK); 4090 } else if (tiwin != tp->snd_wnd) { 4091 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4092 tp->tcp_cnt_counters[ACK_RWND]++; 4093 } 4094 return (ACK_RWND); 4095 } else { 4096 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4097 tp->tcp_cnt_counters[ACK_DUPACK]++; 4098 } 4099 return (ACK_DUPACK); 4100 } 4101 } else { 4102 if (!SEQ_GT(th->th_ack, tp->snd_max)) { 4103 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4104 tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((th->th_ack - tp->snd_una) + mss - 1)/mss); 4105 } 4106 } 4107 if (to->to_flags & TOF_SACK) { 4108 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4109 tp->tcp_cnt_counters[ACK_CUMACK_SACK]++; 4110 } 4111 return (ACK_CUMACK_SACK); 4112 } else { 4113 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) { 4114 tp->tcp_cnt_counters[ACK_CUMACK]++; 4115 } 4116 return (ACK_CUMACK); 4117 } 4118 } 4119 } 4120 #endif 4121 4122 void 4123 tcp_change_time_units(struct tcpcb *tp, int granularity) 4124 { 4125 if (tp->t_tmr_granularity == granularity) { 4126 /* We are there */ 4127 return; 4128 } 4129 if (granularity == TCP_TMR_GRANULARITY_USEC) { 4130 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS), 4131 ("Granularity is not TICKS its %u in tp:%p", 4132 tp->t_tmr_granularity, tp)); 4133 tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow); 4134 if (tp->t_srtt > 1) { 4135 uint32_t val, frac; 4136 4137 val = tp->t_srtt >> TCP_RTT_SHIFT; 4138 frac = tp->t_srtt & 0x1f; 4139 tp->t_srtt = TICKS_2_USEC(val); 4140 /* 4141 * frac is the fractional part of the srtt (if any) 4142 * but its in ticks and every bit represents 4143 * 1/32nd of a hz. 4144 */ 4145 if (frac) { 4146 if (hz == 1000) { 4147 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE); 4148 } else { 4149 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE)); 4150 } 4151 tp->t_srtt += frac; 4152 } 4153 } 4154 if (tp->t_rttvar) { 4155 uint32_t val, frac; 4156 4157 val = tp->t_rttvar >> TCP_RTTVAR_SHIFT; 4158 frac = tp->t_rttvar & 0x1f; 4159 tp->t_rttvar = TICKS_2_USEC(val); 4160 /* 4161 * frac is the fractional part of the srtt (if any) 4162 * but its in ticks and every bit represents 4163 * 1/32nd of a hz. 4164 */ 4165 if (frac) { 4166 if (hz == 1000) { 4167 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE); 4168 } else { 4169 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE)); 4170 } 4171 tp->t_rttvar += frac; 4172 } 4173 } 4174 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_USEC; 4175 } else if (granularity == TCP_TMR_GRANULARITY_TICKS) { 4176 /* Convert back to ticks, with */ 4177 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_USEC), 4178 ("Granularity is not USEC its %u in tp:%p", 4179 tp->t_tmr_granularity, tp)); 4180 if (tp->t_srtt > 1) { 4181 uint32_t val, frac; 4182 4183 val = USEC_2_TICKS(tp->t_srtt); 4184 frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz); 4185 tp->t_srtt = val << TCP_RTT_SHIFT; 4186 /* 4187 * frac is the fractional part here is left 4188 * over from converting to hz and shifting. 4189 * We need to convert this to the 5 bit 4190 * remainder. 4191 */ 4192 if (frac) { 4193 if (hz == 1000) { 4194 frac = (((uint64_t)frac * (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC); 4195 } else { 4196 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC); 4197 } 4198 tp->t_srtt += frac; 4199 } 4200 } 4201 if (tp->t_rttvar) { 4202 uint32_t val, frac; 4203 4204 val = USEC_2_TICKS(tp->t_rttvar); 4205 frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz); 4206 tp->t_rttvar = val << TCP_RTTVAR_SHIFT; 4207 /* 4208 * frac is the fractional part here is left 4209 * over from converting to hz and shifting. 4210 * We need to convert this to the 5 bit 4211 * remainder. 4212 */ 4213 if (frac) { 4214 if (hz == 1000) { 4215 frac = (((uint64_t)frac * (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC); 4216 } else { 4217 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC); 4218 } 4219 tp->t_rttvar += frac; 4220 } 4221 } 4222 tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow); 4223 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS; 4224 } 4225 #ifdef INVARIANTS 4226 else { 4227 panic("Unknown granularity:%d tp:%p", 4228 granularity, tp); 4229 } 4230 #endif 4231 } 4232 4233 void 4234 tcp_handle_orphaned_packets(struct tcpcb *tp) 4235 { 4236 struct mbuf *save, *m, *prev; 4237 /* 4238 * Called when a stack switch is occuring from the fini() 4239 * of the old stack. We assue the init() as already been 4240 * run of the new stack and it has set the t_flags2 to 4241 * what it supports. This function will then deal with any 4242 * differences i.e. cleanup packets that maybe queued that 4243 * the newstack does not support. 4244 */ 4245 4246 if (tp->t_flags2 & TF2_MBUF_L_ACKS) 4247 return; 4248 if ((tp->t_flags2 & TF2_SUPPORTS_MBUFQ) == 0 && 4249 !STAILQ_EMPTY(&tp->t_inqueue)) { 4250 /* 4251 * It is unsafe to process the packets since a 4252 * reset may be lurking in them (its rare but it 4253 * can occur). If we were to find a RST, then we 4254 * would end up dropping the connection and the 4255 * INP lock, so when we return the caller (tcp_usrreq) 4256 * will blow up when it trys to unlock the inp. 4257 * This new stack does not do any fancy LRO features 4258 * so all we can do is toss the packets. 4259 */ 4260 m = STAILQ_FIRST(&tp->t_inqueue); 4261 STAILQ_INIT(&tp->t_inqueue); 4262 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, save) 4263 m_freem(m); 4264 } else { 4265 /* 4266 * Here we have a stack that does mbuf queuing but 4267 * does not support compressed ack's. We must 4268 * walk all the mbufs and discard any compressed acks. 4269 */ 4270 STAILQ_FOREACH_SAFE(m, &tp->t_inqueue, m_stailqpkt, save) { 4271 if (m->m_flags & M_ACKCMP) { 4272 if (m == STAILQ_FIRST(&tp->t_inqueue)) 4273 STAILQ_REMOVE_HEAD(&tp->t_inqueue, 4274 m_stailqpkt); 4275 else 4276 STAILQ_REMOVE_AFTER(&tp->t_inqueue, 4277 prev, m_stailqpkt); 4278 m_freem(m); 4279 } else 4280 prev = m; 4281 } 4282 } 4283 } 4284 4285 #ifdef TCP_REQUEST_TRK 4286 uint32_t 4287 tcp_estimate_tls_overhead(struct socket *so, uint64_t tls_usr_bytes) 4288 { 4289 #ifdef KERN_TLS 4290 struct ktls_session *tls; 4291 uint32_t rec_oh, records; 4292 4293 tls = so->so_snd.sb_tls_info; 4294 if (tls == NULL) 4295 return (0); 4296 4297 rec_oh = tls->params.tls_hlen + tls->params.tls_tlen; 4298 records = ((tls_usr_bytes + tls->params.max_frame_len - 1)/tls->params.max_frame_len); 4299 return (records * rec_oh); 4300 #else 4301 return (0); 4302 #endif 4303 } 4304 4305 extern uint32_t tcp_stale_entry_time; 4306 uint32_t tcp_stale_entry_time = 250000; 4307 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, usrlog_stale, CTLFLAG_RW, 4308 &tcp_stale_entry_time, 250000, "Time that a tcpreq entry without a sendfile ages out"); 4309 4310 void 4311 tcp_req_log_req_info(struct tcpcb *tp, struct tcp_sendfile_track *req, 4312 uint16_t slot, uint8_t val, uint64_t offset, uint64_t nbytes) 4313 { 4314 if (tcp_bblogging_on(tp)) { 4315 union tcp_log_stackspecific log; 4316 struct timeval tv; 4317 4318 memset(&log.u_bbr, 0, sizeof(log.u_bbr)); 4319 #ifdef TCPHPTS 4320 log.u_bbr.inhpts = tcp_in_hpts(tp); 4321 #endif 4322 log.u_bbr.flex8 = val; 4323 log.u_bbr.rttProp = req->timestamp; 4324 log.u_bbr.delRate = req->start; 4325 log.u_bbr.cur_del_rate = req->end; 4326 log.u_bbr.flex1 = req->start_seq; 4327 log.u_bbr.flex2 = req->end_seq; 4328 log.u_bbr.flex3 = req->flags; 4329 log.u_bbr.flex4 = ((req->localtime >> 32) & 0x00000000ffffffff); 4330 log.u_bbr.flex5 = (req->localtime & 0x00000000ffffffff); 4331 log.u_bbr.flex7 = slot; 4332 log.u_bbr.bw_inuse = offset; 4333 /* nbytes = flex6 | epoch */ 4334 log.u_bbr.flex6 = ((nbytes >> 32) & 0x00000000ffffffff); 4335 log.u_bbr.epoch = (nbytes & 0x00000000ffffffff); 4336 /* cspr = lt_epoch | pkts_out */ 4337 log.u_bbr.lt_epoch = ((req->cspr >> 32) & 0x00000000ffffffff); 4338 log.u_bbr.pkts_out |= (req->cspr & 0x00000000ffffffff); 4339 log.u_bbr.applimited = tp->t_tcpreq_closed; 4340 log.u_bbr.applimited <<= 8; 4341 log.u_bbr.applimited |= tp->t_tcpreq_open; 4342 log.u_bbr.applimited <<= 8; 4343 log.u_bbr.applimited |= tp->t_tcpreq_req; 4344 log.u_bbr.timeStamp = tcp_get_usecs(&tv); 4345 TCP_LOG_EVENTP(tp, NULL, 4346 &tptosocket(tp)->so_rcv, 4347 &tptosocket(tp)->so_snd, 4348 TCP_LOG_REQ_T, 0, 4349 0, &log, false, &tv); 4350 } 4351 } 4352 4353 void 4354 tcp_req_free_a_slot(struct tcpcb *tp, struct tcp_sendfile_track *ent) 4355 { 4356 if (tp->t_tcpreq_req > 0) 4357 tp->t_tcpreq_req--; 4358 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) { 4359 if (tp->t_tcpreq_open > 0) 4360 tp->t_tcpreq_open--; 4361 } else { 4362 if (tp->t_tcpreq_closed > 0) 4363 tp->t_tcpreq_closed--; 4364 } 4365 ent->flags = TCP_TRK_TRACK_FLG_EMPTY; 4366 } 4367 4368 static void 4369 tcp_req_check_for_stale_entries(struct tcpcb *tp, uint64_t ts, int rm_oldest) 4370 { 4371 struct tcp_sendfile_track *ent; 4372 uint64_t time_delta, oldest_delta; 4373 int i, oldest, oldest_set = 0, cnt_rm = 0; 4374 4375 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4376 ent = &tp->t_tcpreq_info[i]; 4377 if (ent->flags != TCP_TRK_TRACK_FLG_USED) { 4378 /* 4379 * We only care about closed end ranges 4380 * that are allocated and have no sendfile 4381 * ever touching them. They would be in 4382 * state USED. 4383 */ 4384 continue; 4385 } 4386 if (ts >= ent->localtime) 4387 time_delta = ts - ent->localtime; 4388 else 4389 time_delta = 0; 4390 if (time_delta && 4391 ((oldest_delta < time_delta) || (oldest_set == 0))) { 4392 oldest_set = 1; 4393 oldest = i; 4394 oldest_delta = time_delta; 4395 } 4396 if (tcp_stale_entry_time && (time_delta >= tcp_stale_entry_time)) { 4397 /* 4398 * No sendfile in a our time-limit 4399 * time to purge it. 4400 */ 4401 cnt_rm++; 4402 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE, 4403 time_delta, 0); 4404 tcp_req_free_a_slot(tp, ent); 4405 } 4406 } 4407 if ((cnt_rm == 0) && rm_oldest && oldest_set) { 4408 ent = &tp->t_tcpreq_info[oldest]; 4409 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE, 4410 oldest_delta, 1); 4411 tcp_req_free_a_slot(tp, ent); 4412 } 4413 } 4414 4415 int 4416 tcp_req_check_for_comp(struct tcpcb *tp, tcp_seq ack_point) 4417 { 4418 int i, ret=0; 4419 struct tcp_sendfile_track *ent; 4420 4421 /* Clean up any old closed end requests that are now completed */ 4422 if (tp->t_tcpreq_req == 0) 4423 return(0); 4424 if (tp->t_tcpreq_closed == 0) 4425 return(0); 4426 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4427 ent = &tp->t_tcpreq_info[i]; 4428 /* Skip empty ones */ 4429 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4430 continue; 4431 /* Skip open ones */ 4432 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) 4433 continue; 4434 if (SEQ_GEQ(ack_point, ent->end_seq)) { 4435 /* We are past it -- free it */ 4436 tcp_req_log_req_info(tp, ent, 4437 i, TCP_TRK_REQ_LOG_FREED, 0, 0); 4438 tcp_req_free_a_slot(tp, ent); 4439 ret++; 4440 } 4441 } 4442 return (ret); 4443 } 4444 4445 int 4446 tcp_req_is_entry_comp(struct tcpcb *tp, struct tcp_sendfile_track *ent, tcp_seq ack_point) 4447 { 4448 if (tp->t_tcpreq_req == 0) 4449 return(-1); 4450 if (tp->t_tcpreq_closed == 0) 4451 return(-1); 4452 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4453 return(-1); 4454 if (SEQ_GEQ(ack_point, ent->end_seq)) { 4455 return (1); 4456 } 4457 return (0); 4458 } 4459 4460 struct tcp_sendfile_track * 4461 tcp_req_find_a_req_that_is_completed_by(struct tcpcb *tp, tcp_seq th_ack, int *ip) 4462 { 4463 /* 4464 * Given an ack point (th_ack) walk through our entries and 4465 * return the first one found that th_ack goes past the 4466 * end_seq. 4467 */ 4468 struct tcp_sendfile_track *ent; 4469 int i; 4470 4471 if (tp->t_tcpreq_req == 0) { 4472 /* none open */ 4473 return (NULL); 4474 } 4475 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4476 ent = &tp->t_tcpreq_info[i]; 4477 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) 4478 continue; 4479 if ((ent->flags & TCP_TRK_TRACK_FLG_OPEN) == 0) { 4480 if (SEQ_GEQ(th_ack, ent->end_seq)) { 4481 *ip = i; 4482 return (ent); 4483 } 4484 } 4485 } 4486 return (NULL); 4487 } 4488 4489 struct tcp_sendfile_track * 4490 tcp_req_find_req_for_seq(struct tcpcb *tp, tcp_seq seq) 4491 { 4492 struct tcp_sendfile_track *ent; 4493 int i; 4494 4495 if (tp->t_tcpreq_req == 0) { 4496 /* none open */ 4497 return (NULL); 4498 } 4499 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4500 ent = &tp->t_tcpreq_info[i]; 4501 tcp_req_log_req_info(tp, ent, i, TCP_TRK_REQ_LOG_SEARCH, 4502 (uint64_t)seq, 0); 4503 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) { 4504 continue; 4505 } 4506 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) { 4507 /* 4508 * An open end request only needs to 4509 * match the beginning seq or be 4510 * all we have (once we keep going on 4511 * a open end request we may have a seq 4512 * wrap). 4513 */ 4514 if ((SEQ_GEQ(seq, ent->start_seq)) || 4515 (tp->t_tcpreq_closed == 0)) 4516 return (ent); 4517 } else { 4518 /* 4519 * For this one we need to 4520 * be a bit more careful if its 4521 * completed at least. 4522 */ 4523 if ((SEQ_GEQ(seq, ent->start_seq)) && 4524 (SEQ_LT(seq, ent->end_seq))) { 4525 return (ent); 4526 } 4527 } 4528 } 4529 return (NULL); 4530 } 4531 4532 /* Should this be in its own file tcp_req.c ? */ 4533 struct tcp_sendfile_track * 4534 tcp_req_alloc_req_full(struct tcpcb *tp, struct tcp_snd_req *req, uint64_t ts, int rec_dups) 4535 { 4536 struct tcp_sendfile_track *fil; 4537 int i, allocated; 4538 4539 /* In case the stack does not check for completions do so now */ 4540 tcp_req_check_for_comp(tp, tp->snd_una); 4541 /* Check for stale entries */ 4542 if (tp->t_tcpreq_req) 4543 tcp_req_check_for_stale_entries(tp, ts, 4544 (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ)); 4545 /* Check to see if this is a duplicate of one not started */ 4546 if (tp->t_tcpreq_req) { 4547 for(i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) { 4548 fil = &tp->t_tcpreq_info[i]; 4549 if (fil->flags != TCP_TRK_TRACK_FLG_USED) 4550 continue; 4551 if ((fil->timestamp == req->timestamp) && 4552 (fil->start == req->start) && 4553 ((fil->flags & TCP_TRK_TRACK_FLG_OPEN) || 4554 (fil->end == req->end))) { 4555 /* 4556 * We already have this request 4557 * and it has not been started with sendfile. 4558 * This probably means the user was returned 4559 * a 4xx of some sort and its going to age 4560 * out, lets not duplicate it. 4561 */ 4562 return(fil); 4563 } 4564 } 4565 } 4566 /* Ok if there is no room at the inn we are in trouble */ 4567 if (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ) { 4568 tcp_trace_point(tp, TCP_TP_REQ_LOG_FAIL); 4569 for(i = 0; i < MAX_TCP_TRK_REQ; i++) { 4570 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], 4571 i, TCP_TRK_REQ_LOG_ALLOCFAIL, 0, 0); 4572 } 4573 return (NULL); 4574 } 4575 for(i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) { 4576 fil = &tp->t_tcpreq_info[i]; 4577 if (fil->flags == TCP_TRK_TRACK_FLG_EMPTY) { 4578 allocated = 1; 4579 fil->flags = TCP_TRK_TRACK_FLG_USED; 4580 fil->timestamp = req->timestamp; 4581 fil->localtime = ts; 4582 fil->start = req->start; 4583 if (req->flags & TCP_LOG_HTTPD_RANGE_END) { 4584 fil->end = req->end; 4585 } else { 4586 fil->end = 0; 4587 fil->flags |= TCP_TRK_TRACK_FLG_OPEN; 4588 } 4589 /* 4590 * We can set the min boundaries to the TCP Sequence space, 4591 * but it might be found to be further up when sendfile 4592 * actually runs on this range (if it ever does). 4593 */ 4594 fil->sbcc_at_s = tptosocket(tp)->so_snd.sb_ccc; 4595 fil->start_seq = tp->snd_una + 4596 tptosocket(tp)->so_snd.sb_ccc; 4597 fil->end_seq = (fil->start_seq + ((uint32_t)(fil->end - fil->start))); 4598 if (tptosocket(tp)->so_snd.sb_tls_info) { 4599 /* 4600 * This session is doing TLS. Take a swag guess 4601 * at the overhead. 4602 */ 4603 fil->end_seq += tcp_estimate_tls_overhead( 4604 tptosocket(tp), (fil->end - fil->start)); 4605 } 4606 tp->t_tcpreq_req++; 4607 if (fil->flags & TCP_TRK_TRACK_FLG_OPEN) 4608 tp->t_tcpreq_open++; 4609 else 4610 tp->t_tcpreq_closed++; 4611 tcp_req_log_req_info(tp, fil, i, 4612 TCP_TRK_REQ_LOG_NEW, 0, 0); 4613 break; 4614 } else 4615 fil = NULL; 4616 } 4617 return (fil); 4618 } 4619 4620 void 4621 tcp_req_alloc_req(struct tcpcb *tp, union tcp_log_userdata *user, uint64_t ts) 4622 { 4623 (void)tcp_req_alloc_req_full(tp, &user->tcp_req, ts, 1); 4624 } 4625 #endif 4626 4627 void 4628 tcp_log_socket_option(struct tcpcb *tp, uint32_t option_num, uint32_t option_val, int err) 4629 { 4630 if (tcp_bblogging_on(tp)) { 4631 struct tcp_log_buffer *l; 4632 4633 l = tcp_log_event(tp, NULL, 4634 &tptosocket(tp)->so_rcv, 4635 &tptosocket(tp)->so_snd, 4636 TCP_LOG_SOCKET_OPT, 4637 err, 0, NULL, 1, 4638 NULL, NULL, 0, NULL); 4639 if (l) { 4640 l->tlb_flex1 = option_num; 4641 l->tlb_flex2 = option_val; 4642 } 4643 } 4644 } 4645 4646 uint32_t 4647 tcp_get_srtt(struct tcpcb *tp, int granularity) 4648 { 4649 uint32_t srtt; 4650 4651 KASSERT(granularity == TCP_TMR_GRANULARITY_USEC || 4652 granularity == TCP_TMR_GRANULARITY_TICKS, 4653 ("%s: called with unexpected granularity %d", __func__, 4654 granularity)); 4655 4656 srtt = tp->t_srtt; 4657 4658 /* 4659 * We only support two granularities. If the stored granularity 4660 * does not match the granularity requested by the caller, 4661 * convert the stored value to the requested unit of granularity. 4662 */ 4663 if (tp->t_tmr_granularity != granularity) { 4664 if (granularity == TCP_TMR_GRANULARITY_USEC) 4665 srtt = TICKS_2_USEC(srtt); 4666 else 4667 srtt = USEC_2_TICKS(srtt); 4668 } 4669 4670 /* 4671 * If the srtt is stored with ticks granularity, we need to 4672 * unshift to get the actual value. We do this after the 4673 * conversion above (if one was necessary) in order to maximize 4674 * precision. 4675 */ 4676 if (tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS) 4677 srtt = srtt >> TCP_RTT_SHIFT; 4678 4679 return (srtt); 4680 } 4681