1 /*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_compat.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 #include "opt_ipsec.h" 39 #include "opt_tcpdebug.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.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 #include <sys/sysctl.h> 53 #include <sys/jail.h> 54 #include <sys/malloc.h> 55 #include <sys/refcount.h> 56 #include <sys/mbuf.h> 57 #ifdef INET6 58 #include <sys/domain.h> 59 #endif 60 #include <sys/priv.h> 61 #include <sys/proc.h> 62 #include <sys/sdt.h> 63 #include <sys/socket.h> 64 #include <sys/socketvar.h> 65 #include <sys/protosw.h> 66 #include <sys/random.h> 67 68 #include <vm/uma.h> 69 70 #include <net/route.h> 71 #include <net/if.h> 72 #include <net/if_var.h> 73 #include <net/vnet.h> 74 75 #include <netinet/in.h> 76 #include <netinet/in_fib.h> 77 #include <netinet/in_kdtrace.h> 78 #include <netinet/in_pcb.h> 79 #include <netinet/in_systm.h> 80 #include <netinet/in_var.h> 81 #include <netinet/ip.h> 82 #include <netinet/ip_icmp.h> 83 #include <netinet/ip_var.h> 84 #ifdef INET6 85 #include <netinet/icmp6.h> 86 #include <netinet/ip6.h> 87 #include <netinet6/in6_fib.h> 88 #include <netinet6/in6_pcb.h> 89 #include <netinet6/ip6_var.h> 90 #include <netinet6/scope6_var.h> 91 #include <netinet6/nd6.h> 92 #endif 93 94 #ifdef TCP_RFC7413 95 #include <netinet/tcp_fastopen.h> 96 #endif 97 #include <netinet/tcp.h> 98 #include <netinet/tcp_fsm.h> 99 #include <netinet/tcp_seq.h> 100 #include <netinet/tcp_timer.h> 101 #include <netinet/tcp_var.h> 102 #include <netinet/tcp_syncache.h> 103 #include <netinet/cc/cc.h> 104 #ifdef INET6 105 #include <netinet6/tcp6_var.h> 106 #endif 107 #include <netinet/tcpip.h> 108 #ifdef TCPPCAP 109 #include <netinet/tcp_pcap.h> 110 #endif 111 #ifdef TCPDEBUG 112 #include <netinet/tcp_debug.h> 113 #endif 114 #ifdef INET6 115 #include <netinet6/ip6protosw.h> 116 #endif 117 #ifdef TCP_OFFLOAD 118 #include <netinet/tcp_offload.h> 119 #endif 120 121 #include <netipsec/ipsec_support.h> 122 123 #include <machine/in_cksum.h> 124 #include <sys/md5.h> 125 126 #include <security/mac/mac_framework.h> 127 128 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS; 129 #ifdef INET6 130 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS; 131 #endif 132 133 struct rwlock tcp_function_lock; 134 135 static int 136 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS) 137 { 138 int error, new; 139 140 new = V_tcp_mssdflt; 141 error = sysctl_handle_int(oidp, &new, 0, req); 142 if (error == 0 && req->newptr) { 143 if (new < TCP_MINMSS) 144 error = EINVAL; 145 else 146 V_tcp_mssdflt = new; 147 } 148 return (error); 149 } 150 151 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, 152 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0, 153 &sysctl_net_inet_tcp_mss_check, "I", 154 "Default TCP Maximum Segment Size"); 155 156 #ifdef INET6 157 static int 158 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS) 159 { 160 int error, new; 161 162 new = V_tcp_v6mssdflt; 163 error = sysctl_handle_int(oidp, &new, 0, req); 164 if (error == 0 && req->newptr) { 165 if (new < TCP_MINMSS) 166 error = EINVAL; 167 else 168 V_tcp_v6mssdflt = new; 169 } 170 return (error); 171 } 172 173 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, 174 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0, 175 &sysctl_net_inet_tcp_mss_v6_check, "I", 176 "Default TCP Maximum Segment Size for IPv6"); 177 #endif /* INET6 */ 178 179 /* 180 * Minimum MSS we accept and use. This prevents DoS attacks where 181 * we are forced to a ridiculous low MSS like 20 and send hundreds 182 * of packets instead of one. The effect scales with the available 183 * bandwidth and quickly saturates the CPU and network interface 184 * with packet generation and sending. Set to zero to disable MINMSS 185 * checking. This setting prevents us from sending too small packets. 186 */ 187 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS; 188 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW, 189 &VNET_NAME(tcp_minmss), 0, 190 "Minimum TCP Maximum Segment Size"); 191 192 VNET_DEFINE(int, tcp_do_rfc1323) = 1; 193 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW, 194 &VNET_NAME(tcp_do_rfc1323), 0, 195 "Enable rfc1323 (high performance TCP) extensions"); 196 197 static int tcp_log_debug = 0; 198 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW, 199 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments"); 200 201 static int tcp_tcbhashsize; 202 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, 203 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); 204 205 static int do_tcpdrain = 1; 206 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 207 "Enable tcp_drain routine for extra help when low on mbufs"); 208 209 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD, 210 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs"); 211 212 static VNET_DEFINE(int, icmp_may_rst) = 1; 213 #define V_icmp_may_rst VNET(icmp_may_rst) 214 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW, 215 &VNET_NAME(icmp_may_rst), 0, 216 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 217 218 static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0; 219 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval) 220 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW, 221 &VNET_NAME(tcp_isn_reseed_interval), 0, 222 "Seconds between reseeding of ISN secret"); 223 224 static int tcp_soreceive_stream; 225 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN, 226 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets"); 227 228 VNET_DEFINE(uma_zone_t, sack_hole_zone); 229 #define V_sack_hole_zone VNET(sack_hole_zone) 230 231 #ifdef TCP_HHOOK 232 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]); 233 #endif 234 235 static struct inpcb *tcp_notify(struct inpcb *, int); 236 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int); 237 static void tcp_mtudisc(struct inpcb *, int); 238 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, 239 void *ip4hdr, const void *ip6hdr); 240 241 242 static struct tcp_function_block tcp_def_funcblk = { 243 "default", 244 tcp_output, 245 tcp_do_segment, 246 tcp_default_ctloutput, 247 NULL, 248 NULL, 249 NULL, 250 NULL, 251 NULL, 252 NULL, 253 0, 254 0 255 }; 256 257 int t_functions_inited = 0; 258 struct tcp_funchead t_functions; 259 static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk; 260 261 static void 262 init_tcp_functions(void) 263 { 264 if (t_functions_inited == 0) { 265 TAILQ_INIT(&t_functions); 266 rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0); 267 t_functions_inited = 1; 268 } 269 } 270 271 static struct tcp_function_block * 272 find_tcp_functions_locked(struct tcp_function_set *fs) 273 { 274 struct tcp_function *f; 275 struct tcp_function_block *blk=NULL; 276 277 TAILQ_FOREACH(f, &t_functions, tf_next) { 278 if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) { 279 blk = f->tf_fb; 280 break; 281 } 282 } 283 return(blk); 284 } 285 286 static struct tcp_function_block * 287 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s) 288 { 289 struct tcp_function_block *rblk=NULL; 290 struct tcp_function *f; 291 292 TAILQ_FOREACH(f, &t_functions, tf_next) { 293 if (f->tf_fb == blk) { 294 rblk = blk; 295 if (s) { 296 *s = f; 297 } 298 break; 299 } 300 } 301 return (rblk); 302 } 303 304 struct tcp_function_block * 305 find_and_ref_tcp_functions(struct tcp_function_set *fs) 306 { 307 struct tcp_function_block *blk; 308 309 rw_rlock(&tcp_function_lock); 310 blk = find_tcp_functions_locked(fs); 311 if (blk) 312 refcount_acquire(&blk->tfb_refcnt); 313 rw_runlock(&tcp_function_lock); 314 return(blk); 315 } 316 317 struct tcp_function_block * 318 find_and_ref_tcp_fb(struct tcp_function_block *blk) 319 { 320 struct tcp_function_block *rblk; 321 322 rw_rlock(&tcp_function_lock); 323 rblk = find_tcp_fb_locked(blk, NULL); 324 if (rblk) 325 refcount_acquire(&rblk->tfb_refcnt); 326 rw_runlock(&tcp_function_lock); 327 return(rblk); 328 } 329 330 331 static int 332 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS) 333 { 334 int error=ENOENT; 335 struct tcp_function_set fs; 336 struct tcp_function_block *blk; 337 338 memset(&fs, 0, sizeof(fs)); 339 rw_rlock(&tcp_function_lock); 340 blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL); 341 if (blk) { 342 /* Found him */ 343 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 344 fs.pcbcnt = blk->tfb_refcnt; 345 } 346 rw_runlock(&tcp_function_lock); 347 error = sysctl_handle_string(oidp, fs.function_set_name, 348 sizeof(fs.function_set_name), req); 349 350 /* Check for error or no change */ 351 if (error != 0 || req->newptr == NULL) 352 return(error); 353 354 rw_wlock(&tcp_function_lock); 355 blk = find_tcp_functions_locked(&fs); 356 if ((blk == NULL) || 357 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) { 358 error = ENOENT; 359 goto done; 360 } 361 tcp_func_set_ptr = blk; 362 done: 363 rw_wunlock(&tcp_function_lock); 364 return (error); 365 } 366 367 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default, 368 CTLTYPE_STRING | CTLFLAG_RW, 369 NULL, 0, sysctl_net_inet_default_tcp_functions, "A", 370 "Set/get the default TCP functions"); 371 372 static int 373 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS) 374 { 375 int error, cnt, linesz; 376 struct tcp_function *f; 377 char *buffer, *cp; 378 size_t bufsz, outsz; 379 380 cnt = 0; 381 rw_rlock(&tcp_function_lock); 382 TAILQ_FOREACH(f, &t_functions, tf_next) { 383 cnt++; 384 } 385 rw_runlock(&tcp_function_lock); 386 387 bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1; 388 buffer = malloc(bufsz, M_TEMP, M_WAITOK); 389 390 error = 0; 391 cp = buffer; 392 393 linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count"); 394 cp += linesz; 395 bufsz -= linesz; 396 outsz = linesz; 397 398 rw_rlock(&tcp_function_lock); 399 TAILQ_FOREACH(f, &t_functions, tf_next) { 400 linesz = snprintf(cp, bufsz, "%-32s%c %u\n", 401 f->tf_fb->tfb_tcp_block_name, 402 (f->tf_fb == tcp_func_set_ptr) ? '*' : ' ', 403 f->tf_fb->tfb_refcnt); 404 if (linesz >= bufsz) { 405 error = EOVERFLOW; 406 break; 407 } 408 cp += linesz; 409 bufsz -= linesz; 410 outsz += linesz; 411 } 412 rw_runlock(&tcp_function_lock); 413 if (error == 0) 414 error = sysctl_handle_string(oidp, buffer, outsz + 1, req); 415 free(buffer, M_TEMP); 416 return (error); 417 } 418 419 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available, 420 CTLTYPE_STRING|CTLFLAG_RD, 421 NULL, 0, sysctl_net_inet_list_available, "A", 422 "list available TCP Function sets"); 423 424 /* 425 * Target size of TCP PCB hash tables. Must be a power of two. 426 * 427 * Note that this can be overridden by the kernel environment 428 * variable net.inet.tcp.tcbhashsize 429 */ 430 #ifndef TCBHASHSIZE 431 #define TCBHASHSIZE 0 432 #endif 433 434 /* 435 * XXX 436 * Callouts should be moved into struct tcp directly. They are currently 437 * separate because the tcpcb structure is exported to userland for sysctl 438 * parsing purposes, which do not know about callouts. 439 */ 440 struct tcpcb_mem { 441 struct tcpcb tcb; 442 struct tcp_timer tt; 443 struct cc_var ccv; 444 #ifdef TCP_HHOOK 445 struct osd osd; 446 #endif 447 }; 448 449 static VNET_DEFINE(uma_zone_t, tcpcb_zone); 450 #define V_tcpcb_zone VNET(tcpcb_zone) 451 452 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers"); 453 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory"); 454 455 static struct mtx isn_mtx; 456 457 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF) 458 #define ISN_LOCK() mtx_lock(&isn_mtx) 459 #define ISN_UNLOCK() mtx_unlock(&isn_mtx) 460 461 /* 462 * TCP initialization. 463 */ 464 static void 465 tcp_zone_change(void *tag) 466 { 467 468 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets); 469 uma_zone_set_max(V_tcpcb_zone, maxsockets); 470 tcp_tw_zone_change(); 471 } 472 473 static int 474 tcp_inpcb_init(void *mem, int size, int flags) 475 { 476 struct inpcb *inp = mem; 477 478 INP_LOCK_INIT(inp, "inp", "tcpinp"); 479 return (0); 480 } 481 482 /* 483 * Take a value and get the next power of 2 that doesn't overflow. 484 * Used to size the tcp_inpcb hash buckets. 485 */ 486 static int 487 maketcp_hashsize(int size) 488 { 489 int hashsize; 490 491 /* 492 * auto tune. 493 * get the next power of 2 higher than maxsockets. 494 */ 495 hashsize = 1 << fls(size); 496 /* catch overflow, and just go one power of 2 smaller */ 497 if (hashsize < size) { 498 hashsize = 1 << (fls(size) - 1); 499 } 500 return (hashsize); 501 } 502 503 int 504 register_tcp_functions(struct tcp_function_block *blk, int wait) 505 { 506 struct tcp_function_block *lblk; 507 struct tcp_function *n; 508 struct tcp_function_set fs; 509 510 if (t_functions_inited == 0) { 511 init_tcp_functions(); 512 } 513 if ((blk->tfb_tcp_output == NULL) || 514 (blk->tfb_tcp_do_segment == NULL) || 515 (blk->tfb_tcp_ctloutput == NULL) || 516 (strlen(blk->tfb_tcp_block_name) == 0)) { 517 /* 518 * These functions are required and you 519 * need a name. 520 */ 521 return (EINVAL); 522 } 523 if (blk->tfb_tcp_timer_stop_all || 524 blk->tfb_tcp_timer_activate || 525 blk->tfb_tcp_timer_active || 526 blk->tfb_tcp_timer_stop) { 527 /* 528 * If you define one timer function you 529 * must have them all. 530 */ 531 if ((blk->tfb_tcp_timer_stop_all == NULL) || 532 (blk->tfb_tcp_timer_activate == NULL) || 533 (blk->tfb_tcp_timer_active == NULL) || 534 (blk->tfb_tcp_timer_stop == NULL)) { 535 return (EINVAL); 536 } 537 } 538 n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait); 539 if (n == NULL) { 540 return (ENOMEM); 541 } 542 n->tf_fb = blk; 543 strcpy(fs.function_set_name, blk->tfb_tcp_block_name); 544 rw_wlock(&tcp_function_lock); 545 lblk = find_tcp_functions_locked(&fs); 546 if (lblk) { 547 /* Duplicate name space not allowed */ 548 rw_wunlock(&tcp_function_lock); 549 free(n, M_TCPFUNCTIONS); 550 return (EALREADY); 551 } 552 refcount_init(&blk->tfb_refcnt, 0); 553 blk->tfb_flags = 0; 554 TAILQ_INSERT_TAIL(&t_functions, n, tf_next); 555 rw_wunlock(&tcp_function_lock); 556 return(0); 557 } 558 559 int 560 deregister_tcp_functions(struct tcp_function_block *blk) 561 { 562 struct tcp_function_block *lblk; 563 struct tcp_function *f; 564 int error=ENOENT; 565 566 if (strcmp(blk->tfb_tcp_block_name, "default") == 0) { 567 /* You can't un-register the default */ 568 return (EPERM); 569 } 570 rw_wlock(&tcp_function_lock); 571 if (blk == tcp_func_set_ptr) { 572 /* You can't free the current default */ 573 rw_wunlock(&tcp_function_lock); 574 return (EBUSY); 575 } 576 if (blk->tfb_refcnt) { 577 /* Still tcb attached, mark it. */ 578 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED; 579 rw_wunlock(&tcp_function_lock); 580 return (EBUSY); 581 } 582 lblk = find_tcp_fb_locked(blk, &f); 583 if (lblk) { 584 /* Found */ 585 TAILQ_REMOVE(&t_functions, f, tf_next); 586 f->tf_fb = NULL; 587 free(f, M_TCPFUNCTIONS); 588 error = 0; 589 } 590 rw_wunlock(&tcp_function_lock); 591 return (error); 592 } 593 594 void 595 tcp_init(void) 596 { 597 const char *tcbhash_tuneable; 598 int hashsize; 599 600 tcbhash_tuneable = "net.inet.tcp.tcbhashsize"; 601 602 #ifdef TCP_HHOOK 603 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, 604 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 605 printf("%s: WARNING: unable to register helper hook\n", __func__); 606 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, 607 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0) 608 printf("%s: WARNING: unable to register helper hook\n", __func__); 609 #endif 610 hashsize = TCBHASHSIZE; 611 TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize); 612 if (hashsize == 0) { 613 /* 614 * Auto tune the hash size based on maxsockets. 615 * A perfect hash would have a 1:1 mapping 616 * (hashsize = maxsockets) however it's been 617 * suggested that O(2) average is better. 618 */ 619 hashsize = maketcp_hashsize(maxsockets / 4); 620 /* 621 * Our historical default is 512, 622 * do not autotune lower than this. 623 */ 624 if (hashsize < 512) 625 hashsize = 512; 626 if (bootverbose && IS_DEFAULT_VNET(curvnet)) 627 printf("%s: %s auto tuned to %d\n", __func__, 628 tcbhash_tuneable, hashsize); 629 } 630 /* 631 * We require a hashsize to be a power of two. 632 * Previously if it was not a power of two we would just reset it 633 * back to 512, which could be a nasty surprise if you did not notice 634 * the error message. 635 * Instead what we do is clip it to the closest power of two lower 636 * than the specified hash value. 637 */ 638 if (!powerof2(hashsize)) { 639 int oldhashsize = hashsize; 640 641 hashsize = maketcp_hashsize(hashsize); 642 /* prevent absurdly low value */ 643 if (hashsize < 16) 644 hashsize = 16; 645 printf("%s: WARNING: TCB hash size not a power of 2, " 646 "clipped from %d to %d.\n", __func__, oldhashsize, 647 hashsize); 648 } 649 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize, 650 "tcp_inpcb", tcp_inpcb_init, IPI_HASHFIELDS_4TUPLE); 651 652 /* 653 * These have to be type stable for the benefit of the timers. 654 */ 655 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem), 656 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 657 uma_zone_set_max(V_tcpcb_zone, maxsockets); 658 uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached"); 659 660 tcp_tw_init(); 661 syncache_init(); 662 tcp_hc_init(); 663 664 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack); 665 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 666 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 667 668 #ifdef TCP_RFC7413 669 tcp_fastopen_init(); 670 #endif 671 672 /* Skip initialization of globals for non-default instances. */ 673 if (!IS_DEFAULT_VNET(curvnet)) 674 return; 675 676 tcp_reass_global_init(); 677 678 /* XXX virtualize those bellow? */ 679 tcp_delacktime = TCPTV_DELACK; 680 tcp_keepinit = TCPTV_KEEP_INIT; 681 tcp_keepidle = TCPTV_KEEP_IDLE; 682 tcp_keepintvl = TCPTV_KEEPINTVL; 683 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 684 tcp_msl = TCPTV_MSL; 685 tcp_rexmit_min = TCPTV_MIN; 686 if (tcp_rexmit_min < 1) 687 tcp_rexmit_min = 1; 688 tcp_persmin = TCPTV_PERSMIN; 689 tcp_persmax = TCPTV_PERSMAX; 690 tcp_rexmit_slop = TCPTV_CPU_VAR; 691 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 692 tcp_tcbhashsize = hashsize; 693 /* Setup the tcp function block list */ 694 init_tcp_functions(); 695 register_tcp_functions(&tcp_def_funcblk, M_WAITOK); 696 697 if (tcp_soreceive_stream) { 698 #ifdef INET 699 tcp_usrreqs.pru_soreceive = soreceive_stream; 700 #endif 701 #ifdef INET6 702 tcp6_usrreqs.pru_soreceive = soreceive_stream; 703 #endif /* INET6 */ 704 } 705 706 #ifdef INET6 707 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 708 #else /* INET6 */ 709 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 710 #endif /* INET6 */ 711 if (max_protohdr < TCP_MINPROTOHDR) 712 max_protohdr = TCP_MINPROTOHDR; 713 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 714 panic("tcp_init"); 715 #undef TCP_MINPROTOHDR 716 717 ISN_LOCK_INIT(); 718 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 719 SHUTDOWN_PRI_DEFAULT); 720 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 721 EVENTHANDLER_PRI_ANY); 722 #ifdef TCPPCAP 723 tcp_pcap_init(); 724 #endif 725 } 726 727 #ifdef VIMAGE 728 static void 729 tcp_destroy(void *unused __unused) 730 { 731 int n; 732 #ifdef TCP_HHOOK 733 int error; 734 #endif 735 736 /* 737 * All our processes are gone, all our sockets should be cleaned 738 * up, which means, we should be past the tcp_discardcb() calls. 739 * Sleep to let all tcpcb timers really disappear and cleanup. 740 */ 741 for (;;) { 742 INP_LIST_RLOCK(&V_tcbinfo); 743 n = V_tcbinfo.ipi_count; 744 INP_LIST_RUNLOCK(&V_tcbinfo); 745 if (n == 0) 746 break; 747 pause("tcpdes", hz / 10); 748 } 749 tcp_hc_destroy(); 750 syncache_destroy(); 751 tcp_tw_destroy(); 752 in_pcbinfo_destroy(&V_tcbinfo); 753 /* tcp_discardcb() clears the sack_holes up. */ 754 uma_zdestroy(V_sack_hole_zone); 755 uma_zdestroy(V_tcpcb_zone); 756 757 #ifdef TCP_RFC7413 758 /* 759 * Cannot free the zone until all tcpcbs are released as we attach 760 * the allocations to them. 761 */ 762 tcp_fastopen_destroy(); 763 #endif 764 765 #ifdef TCP_HHOOK 766 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]); 767 if (error != 0) { 768 printf("%s: WARNING: unable to deregister helper hook " 769 "type=%d, id=%d: error %d returned\n", __func__, 770 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error); 771 } 772 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]); 773 if (error != 0) { 774 printf("%s: WARNING: unable to deregister helper hook " 775 "type=%d, id=%d: error %d returned\n", __func__, 776 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error); 777 } 778 #endif 779 } 780 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL); 781 #endif 782 783 void 784 tcp_fini(void *xtp) 785 { 786 787 } 788 789 /* 790 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 791 * tcp_template used to store this data in mbufs, but we now recopy it out 792 * of the tcpcb each time to conserve mbufs. 793 */ 794 void 795 tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 796 { 797 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 798 799 INP_WLOCK_ASSERT(inp); 800 801 #ifdef INET6 802 if ((inp->inp_vflag & INP_IPV6) != 0) { 803 struct ip6_hdr *ip6; 804 805 ip6 = (struct ip6_hdr *)ip_ptr; 806 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 807 (inp->inp_flow & IPV6_FLOWINFO_MASK); 808 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 809 (IPV6_VERSION & IPV6_VERSION_MASK); 810 ip6->ip6_nxt = IPPROTO_TCP; 811 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 812 ip6->ip6_src = inp->in6p_laddr; 813 ip6->ip6_dst = inp->in6p_faddr; 814 } 815 #endif /* INET6 */ 816 #if defined(INET6) && defined(INET) 817 else 818 #endif 819 #ifdef INET 820 { 821 struct ip *ip; 822 823 ip = (struct ip *)ip_ptr; 824 ip->ip_v = IPVERSION; 825 ip->ip_hl = 5; 826 ip->ip_tos = inp->inp_ip_tos; 827 ip->ip_len = 0; 828 ip->ip_id = 0; 829 ip->ip_off = 0; 830 ip->ip_ttl = inp->inp_ip_ttl; 831 ip->ip_sum = 0; 832 ip->ip_p = IPPROTO_TCP; 833 ip->ip_src = inp->inp_laddr; 834 ip->ip_dst = inp->inp_faddr; 835 } 836 #endif /* INET */ 837 th->th_sport = inp->inp_lport; 838 th->th_dport = inp->inp_fport; 839 th->th_seq = 0; 840 th->th_ack = 0; 841 th->th_x2 = 0; 842 th->th_off = 5; 843 th->th_flags = 0; 844 th->th_win = 0; 845 th->th_urp = 0; 846 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 847 } 848 849 /* 850 * Create template to be used to send tcp packets on a connection. 851 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 852 * use for this function is in keepalives, which use tcp_respond. 853 */ 854 struct tcptemp * 855 tcpip_maketemplate(struct inpcb *inp) 856 { 857 struct tcptemp *t; 858 859 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 860 if (t == NULL) 861 return (NULL); 862 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 863 return (t); 864 } 865 866 /* 867 * Send a single message to the TCP at address specified by 868 * the given TCP/IP header. If m == NULL, then we make a copy 869 * of the tcpiphdr at th and send directly to the addressed host. 870 * This is used to force keep alive messages out using the TCP 871 * template for a connection. If flags are given then we send 872 * a message back to the TCP which originated the segment th, 873 * and discard the mbuf containing it and any other attached mbufs. 874 * 875 * In any case the ack and sequence number of the transmitted 876 * segment are as specified by the parameters. 877 * 878 * NOTE: If m != NULL, then th must point to *inside* the mbuf. 879 */ 880 void 881 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 882 tcp_seq ack, tcp_seq seq, int flags) 883 { 884 struct tcpopt to; 885 struct inpcb *inp; 886 struct ip *ip; 887 struct mbuf *optm; 888 struct tcphdr *nth; 889 u_char *optp; 890 #ifdef INET6 891 struct ip6_hdr *ip6; 892 int isipv6; 893 #endif /* INET6 */ 894 int optlen, tlen, win; 895 bool incl_opts; 896 897 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 898 899 #ifdef INET6 900 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4); 901 ip6 = ipgen; 902 #endif /* INET6 */ 903 ip = ipgen; 904 905 if (tp != NULL) { 906 inp = tp->t_inpcb; 907 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 908 INP_WLOCK_ASSERT(inp); 909 } else 910 inp = NULL; 911 912 incl_opts = false; 913 win = 0; 914 if (tp != NULL) { 915 if (!(flags & TH_RST)) { 916 win = sbspace(&inp->inp_socket->so_rcv); 917 if (win > TCP_MAXWIN << tp->rcv_scale) 918 win = TCP_MAXWIN << tp->rcv_scale; 919 } 920 if ((tp->t_flags & TF_NOOPT) == 0) 921 incl_opts = true; 922 } 923 if (m == NULL) { 924 m = m_gethdr(M_NOWAIT, MT_DATA); 925 if (m == NULL) 926 return; 927 m->m_data += max_linkhdr; 928 #ifdef INET6 929 if (isipv6) { 930 bcopy((caddr_t)ip6, mtod(m, caddr_t), 931 sizeof(struct ip6_hdr)); 932 ip6 = mtod(m, struct ip6_hdr *); 933 nth = (struct tcphdr *)(ip6 + 1); 934 } else 935 #endif /* INET6 */ 936 { 937 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 938 ip = mtod(m, struct ip *); 939 nth = (struct tcphdr *)(ip + 1); 940 } 941 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 942 flags = TH_ACK; 943 } else if (!M_WRITABLE(m)) { 944 struct mbuf *n; 945 946 /* Can't reuse 'm', allocate a new mbuf. */ 947 n = m_gethdr(M_NOWAIT, MT_DATA); 948 if (n == NULL) { 949 m_freem(m); 950 return; 951 } 952 953 if (!m_dup_pkthdr(n, m, M_NOWAIT)) { 954 m_freem(m); 955 m_freem(n); 956 return; 957 } 958 959 n->m_data += max_linkhdr; 960 /* m_len is set later */ 961 #define xchg(a,b,type) { type t; t=a; a=b; b=t; } 962 #ifdef INET6 963 if (isipv6) { 964 bcopy((caddr_t)ip6, mtod(n, caddr_t), 965 sizeof(struct ip6_hdr)); 966 ip6 = mtod(n, struct ip6_hdr *); 967 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 968 nth = (struct tcphdr *)(ip6 + 1); 969 } else 970 #endif /* INET6 */ 971 { 972 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip)); 973 ip = mtod(n, struct ip *); 974 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 975 nth = (struct tcphdr *)(ip + 1); 976 } 977 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 978 xchg(nth->th_dport, nth->th_sport, uint16_t); 979 th = nth; 980 m_freem(m); 981 m = n; 982 } else { 983 /* 984 * reuse the mbuf. 985 * XXX MRT We inherit the FIB, which is lucky. 986 */ 987 m_freem(m->m_next); 988 m->m_next = NULL; 989 m->m_data = (caddr_t)ipgen; 990 /* m_len is set later */ 991 #ifdef INET6 992 if (isipv6) { 993 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 994 nth = (struct tcphdr *)(ip6 + 1); 995 } else 996 #endif /* INET6 */ 997 { 998 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 999 nth = (struct tcphdr *)(ip + 1); 1000 } 1001 if (th != nth) { 1002 /* 1003 * this is usually a case when an extension header 1004 * exists between the IPv6 header and the 1005 * TCP header. 1006 */ 1007 nth->th_sport = th->th_sport; 1008 nth->th_dport = th->th_dport; 1009 } 1010 xchg(nth->th_dport, nth->th_sport, uint16_t); 1011 #undef xchg 1012 } 1013 tlen = 0; 1014 #ifdef INET6 1015 if (isipv6) 1016 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 1017 #endif 1018 #if defined(INET) && defined(INET6) 1019 else 1020 #endif 1021 #ifdef INET 1022 tlen = sizeof (struct tcpiphdr); 1023 #endif 1024 #ifdef INVARIANTS 1025 m->m_len = 0; 1026 KASSERT(M_TRAILINGSPACE(m) >= tlen, 1027 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)", 1028 m, tlen, (long)M_TRAILINGSPACE(m))); 1029 #endif 1030 m->m_len = tlen; 1031 to.to_flags = 0; 1032 if (incl_opts) { 1033 /* Make sure we have room. */ 1034 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) { 1035 m->m_next = m_get(M_NOWAIT, MT_DATA); 1036 if (m->m_next) { 1037 optp = mtod(m->m_next, u_char *); 1038 optm = m->m_next; 1039 } else 1040 incl_opts = false; 1041 } else { 1042 optp = (u_char *) (nth + 1); 1043 optm = m; 1044 } 1045 } 1046 if (incl_opts) { 1047 /* Timestamps. */ 1048 if (tp->t_flags & TF_RCVD_TSTMP) { 1049 to.to_tsval = tcp_ts_getticks() + tp->ts_offset; 1050 to.to_tsecr = tp->ts_recent; 1051 to.to_flags |= TOF_TS; 1052 } 1053 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1054 /* TCP-MD5 (RFC2385). */ 1055 if (tp->t_flags & TF_SIGNATURE) 1056 to.to_flags |= TOF_SIGNATURE; 1057 #endif 1058 /* Add the options. */ 1059 tlen += optlen = tcp_addoptions(&to, optp); 1060 1061 /* Update m_len in the correct mbuf. */ 1062 optm->m_len += optlen; 1063 } else 1064 optlen = 0; 1065 #ifdef INET6 1066 if (isipv6) { 1067 ip6->ip6_flow = 0; 1068 ip6->ip6_vfc = IPV6_VERSION; 1069 ip6->ip6_nxt = IPPROTO_TCP; 1070 ip6->ip6_plen = htons(tlen - sizeof(*ip6)); 1071 } 1072 #endif 1073 #if defined(INET) && defined(INET6) 1074 else 1075 #endif 1076 #ifdef INET 1077 { 1078 ip->ip_len = htons(tlen); 1079 ip->ip_ttl = V_ip_defttl; 1080 if (V_path_mtu_discovery) 1081 ip->ip_off |= htons(IP_DF); 1082 } 1083 #endif 1084 m->m_pkthdr.len = tlen; 1085 m->m_pkthdr.rcvif = NULL; 1086 #ifdef MAC 1087 if (inp != NULL) { 1088 /* 1089 * Packet is associated with a socket, so allow the 1090 * label of the response to reflect the socket label. 1091 */ 1092 INP_WLOCK_ASSERT(inp); 1093 mac_inpcb_create_mbuf(inp, m); 1094 } else { 1095 /* 1096 * Packet is not associated with a socket, so possibly 1097 * update the label in place. 1098 */ 1099 mac_netinet_tcp_reply(m); 1100 } 1101 #endif 1102 nth->th_seq = htonl(seq); 1103 nth->th_ack = htonl(ack); 1104 nth->th_x2 = 0; 1105 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2; 1106 nth->th_flags = flags; 1107 if (tp != NULL) 1108 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 1109 else 1110 nth->th_win = htons((u_short)win); 1111 nth->th_urp = 0; 1112 1113 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 1114 if (to.to_flags & TOF_SIGNATURE) { 1115 if (!TCPMD5_ENABLED() || 1116 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) { 1117 m_freem(m); 1118 return; 1119 } 1120 } 1121 #endif 1122 1123 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 1124 #ifdef INET6 1125 if (isipv6) { 1126 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 1127 nth->th_sum = in6_cksum_pseudo(ip6, 1128 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0); 1129 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 1130 NULL, NULL); 1131 } 1132 #endif /* INET6 */ 1133 #if defined(INET6) && defined(INET) 1134 else 1135 #endif 1136 #ifdef INET 1137 { 1138 m->m_pkthdr.csum_flags = CSUM_TCP; 1139 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 1140 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 1141 } 1142 #endif /* INET */ 1143 #ifdef TCPDEBUG 1144 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 1145 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 1146 #endif 1147 TCP_PROBE3(debug__output, tp, th, m); 1148 if (flags & TH_RST) 1149 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth); 1150 1151 TCP_PROBE5(send, NULL, tp, m, tp, nth); 1152 #ifdef INET6 1153 if (isipv6) 1154 (void) ip6_output(m, NULL, NULL, 0, NULL, NULL, inp); 1155 #endif /* INET6 */ 1156 #if defined(INET) && defined(INET6) 1157 else 1158 #endif 1159 #ifdef INET 1160 (void) ip_output(m, NULL, NULL, 0, NULL, inp); 1161 #endif 1162 } 1163 1164 /* 1165 * Create a new TCP control block, making an 1166 * empty reassembly queue and hooking it to the argument 1167 * protocol control block. The `inp' parameter must have 1168 * come from the zone allocator set up in tcp_init(). 1169 */ 1170 struct tcpcb * 1171 tcp_newtcpcb(struct inpcb *inp) 1172 { 1173 struct tcpcb_mem *tm; 1174 struct tcpcb *tp; 1175 #ifdef INET6 1176 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1177 #endif /* INET6 */ 1178 1179 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 1180 if (tm == NULL) 1181 return (NULL); 1182 tp = &tm->tcb; 1183 1184 /* Initialise cc_var struct for this tcpcb. */ 1185 tp->ccv = &tm->ccv; 1186 tp->ccv->type = IPPROTO_TCP; 1187 tp->ccv->ccvc.tcp = tp; 1188 rw_rlock(&tcp_function_lock); 1189 tp->t_fb = tcp_func_set_ptr; 1190 refcount_acquire(&tp->t_fb->tfb_refcnt); 1191 rw_runlock(&tcp_function_lock); 1192 /* 1193 * Use the current system default CC algorithm. 1194 */ 1195 CC_LIST_RLOCK(); 1196 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!")); 1197 CC_ALGO(tp) = CC_DEFAULT(); 1198 CC_LIST_RUNLOCK(); 1199 1200 if (CC_ALGO(tp)->cb_init != NULL) 1201 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) { 1202 if (tp->t_fb->tfb_tcp_fb_fini) 1203 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1204 refcount_release(&tp->t_fb->tfb_refcnt); 1205 uma_zfree(V_tcpcb_zone, tm); 1206 return (NULL); 1207 } 1208 1209 #ifdef TCP_HHOOK 1210 tp->osd = &tm->osd; 1211 if (khelp_init_osd(HELPER_CLASS_TCP, tp->osd)) { 1212 if (tp->t_fb->tfb_tcp_fb_fini) 1213 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1214 refcount_release(&tp->t_fb->tfb_refcnt); 1215 uma_zfree(V_tcpcb_zone, tm); 1216 return (NULL); 1217 } 1218 #endif 1219 1220 #ifdef VIMAGE 1221 tp->t_vnet = inp->inp_vnet; 1222 #endif 1223 tp->t_timers = &tm->tt; 1224 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 1225 tp->t_maxseg = 1226 #ifdef INET6 1227 isipv6 ? V_tcp_v6mssdflt : 1228 #endif /* INET6 */ 1229 V_tcp_mssdflt; 1230 1231 /* Set up our timeouts. */ 1232 callout_init(&tp->t_timers->tt_rexmt, 1); 1233 callout_init(&tp->t_timers->tt_persist, 1); 1234 callout_init(&tp->t_timers->tt_keep, 1); 1235 callout_init(&tp->t_timers->tt_2msl, 1); 1236 callout_init(&tp->t_timers->tt_delack, 1); 1237 1238 if (V_tcp_do_rfc1323) 1239 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 1240 if (V_tcp_do_sack) 1241 tp->t_flags |= TF_SACK_PERMIT; 1242 TAILQ_INIT(&tp->snd_holes); 1243 /* 1244 * The tcpcb will hold a reference on its inpcb until tcp_discardcb() 1245 * is called. 1246 */ 1247 in_pcbref(inp); /* Reference for tcpcb */ 1248 tp->t_inpcb = inp; 1249 1250 /* 1251 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 1252 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 1253 * reasonable initial retransmit time. 1254 */ 1255 tp->t_srtt = TCPTV_SRTTBASE; 1256 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 1257 tp->t_rttmin = tcp_rexmit_min; 1258 tp->t_rxtcur = TCPTV_RTOBASE; 1259 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1260 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1261 tp->t_rcvtime = ticks; 1262 /* 1263 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 1264 * because the socket may be bound to an IPv6 wildcard address, 1265 * which may match an IPv4-mapped IPv6 address. 1266 */ 1267 inp->inp_ip_ttl = V_ip_defttl; 1268 inp->inp_ppcb = tp; 1269 #ifdef TCPPCAP 1270 /* 1271 * Init the TCP PCAP queues. 1272 */ 1273 tcp_pcap_tcpcb_init(tp); 1274 #endif 1275 if (tp->t_fb->tfb_tcp_fb_init) { 1276 (*tp->t_fb->tfb_tcp_fb_init)(tp); 1277 } 1278 return (tp); /* XXX */ 1279 } 1280 1281 /* 1282 * Switch the congestion control algorithm back to NewReno for any active 1283 * control blocks using an algorithm which is about to go away. 1284 * This ensures the CC framework can allow the unload to proceed without leaving 1285 * any dangling pointers which would trigger a panic. 1286 * Returning non-zero would inform the CC framework that something went wrong 1287 * and it would be unsafe to allow the unload to proceed. However, there is no 1288 * way for this to occur with this implementation so we always return zero. 1289 */ 1290 int 1291 tcp_ccalgounload(struct cc_algo *unload_algo) 1292 { 1293 struct cc_algo *tmpalgo; 1294 struct inpcb *inp; 1295 struct tcpcb *tp; 1296 VNET_ITERATOR_DECL(vnet_iter); 1297 1298 /* 1299 * Check all active control blocks across all network stacks and change 1300 * any that are using "unload_algo" back to NewReno. If "unload_algo" 1301 * requires cleanup code to be run, call it. 1302 */ 1303 VNET_LIST_RLOCK(); 1304 VNET_FOREACH(vnet_iter) { 1305 CURVNET_SET(vnet_iter); 1306 INP_INFO_WLOCK(&V_tcbinfo); 1307 /* 1308 * New connections already part way through being initialised 1309 * with the CC algo we're removing will not race with this code 1310 * because the INP_INFO_WLOCK is held during initialisation. We 1311 * therefore don't enter the loop below until the connection 1312 * list has stabilised. 1313 */ 1314 LIST_FOREACH(inp, &V_tcb, inp_list) { 1315 INP_WLOCK(inp); 1316 /* Important to skip tcptw structs. */ 1317 if (!(inp->inp_flags & INP_TIMEWAIT) && 1318 (tp = intotcpcb(inp)) != NULL) { 1319 /* 1320 * By holding INP_WLOCK here, we are assured 1321 * that the connection is not currently 1322 * executing inside the CC module's functions 1323 * i.e. it is safe to make the switch back to 1324 * NewReno. 1325 */ 1326 if (CC_ALGO(tp) == unload_algo) { 1327 tmpalgo = CC_ALGO(tp); 1328 /* NewReno does not require any init. */ 1329 CC_ALGO(tp) = &newreno_cc_algo; 1330 if (tmpalgo->cb_destroy != NULL) 1331 tmpalgo->cb_destroy(tp->ccv); 1332 } 1333 } 1334 INP_WUNLOCK(inp); 1335 } 1336 INP_INFO_WUNLOCK(&V_tcbinfo); 1337 CURVNET_RESTORE(); 1338 } 1339 VNET_LIST_RUNLOCK(); 1340 1341 return (0); 1342 } 1343 1344 /* 1345 * Drop a TCP connection, reporting 1346 * the specified error. If connection is synchronized, 1347 * then send a RST to peer. 1348 */ 1349 struct tcpcb * 1350 tcp_drop(struct tcpcb *tp, int errno) 1351 { 1352 struct socket *so = tp->t_inpcb->inp_socket; 1353 1354 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1355 INP_WLOCK_ASSERT(tp->t_inpcb); 1356 1357 if (TCPS_HAVERCVDSYN(tp->t_state)) { 1358 tcp_state_change(tp, TCPS_CLOSED); 1359 (void) tp->t_fb->tfb_tcp_output(tp); 1360 TCPSTAT_INC(tcps_drops); 1361 } else 1362 TCPSTAT_INC(tcps_conndrops); 1363 if (errno == ETIMEDOUT && tp->t_softerror) 1364 errno = tp->t_softerror; 1365 so->so_error = errno; 1366 return (tcp_close(tp)); 1367 } 1368 1369 void 1370 tcp_discardcb(struct tcpcb *tp) 1371 { 1372 struct inpcb *inp = tp->t_inpcb; 1373 struct socket *so = inp->inp_socket; 1374 #ifdef INET6 1375 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 1376 #endif /* INET6 */ 1377 int released; 1378 1379 INP_WLOCK_ASSERT(inp); 1380 1381 /* 1382 * Make sure that all of our timers are stopped before we delete the 1383 * PCB. 1384 * 1385 * If stopping a timer fails, we schedule a discard function in same 1386 * callout, and the last discard function called will take care of 1387 * deleting the tcpcb. 1388 */ 1389 tp->t_timers->tt_draincnt = 0; 1390 tcp_timer_stop(tp, TT_REXMT); 1391 tcp_timer_stop(tp, TT_PERSIST); 1392 tcp_timer_stop(tp, TT_KEEP); 1393 tcp_timer_stop(tp, TT_2MSL); 1394 tcp_timer_stop(tp, TT_DELACK); 1395 if (tp->t_fb->tfb_tcp_timer_stop_all) { 1396 /* 1397 * Call the stop-all function of the methods, 1398 * this function should call the tcp_timer_stop() 1399 * method with each of the function specific timeouts. 1400 * That stop will be called via the tfb_tcp_timer_stop() 1401 * which should use the async drain function of the 1402 * callout system (see tcp_var.h). 1403 */ 1404 tp->t_fb->tfb_tcp_timer_stop_all(tp); 1405 } 1406 1407 /* 1408 * If we got enough samples through the srtt filter, 1409 * save the rtt and rttvar in the routing entry. 1410 * 'Enough' is arbitrarily defined as 4 rtt samples. 1411 * 4 samples is enough for the srtt filter to converge 1412 * to within enough % of the correct value; fewer samples 1413 * and we could save a bogus rtt. The danger is not high 1414 * as tcp quickly recovers from everything. 1415 * XXX: Works very well but needs some more statistics! 1416 */ 1417 if (tp->t_rttupdated >= 4) { 1418 struct hc_metrics_lite metrics; 1419 uint32_t ssthresh; 1420 1421 bzero(&metrics, sizeof(metrics)); 1422 /* 1423 * Update the ssthresh always when the conditions below 1424 * are satisfied. This gives us better new start value 1425 * for the congestion avoidance for new connections. 1426 * ssthresh is only set if packet loss occurred on a session. 1427 * 1428 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 1429 * being torn down. Ideally this code would not use 'so'. 1430 */ 1431 ssthresh = tp->snd_ssthresh; 1432 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 1433 /* 1434 * convert the limit from user data bytes to 1435 * packets then to packet data bytes. 1436 */ 1437 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 1438 if (ssthresh < 2) 1439 ssthresh = 2; 1440 ssthresh *= (tp->t_maxseg + 1441 #ifdef INET6 1442 (isipv6 ? sizeof (struct ip6_hdr) + 1443 sizeof (struct tcphdr) : 1444 #endif 1445 sizeof (struct tcpiphdr) 1446 #ifdef INET6 1447 ) 1448 #endif 1449 ); 1450 } else 1451 ssthresh = 0; 1452 metrics.rmx_ssthresh = ssthresh; 1453 1454 metrics.rmx_rtt = tp->t_srtt; 1455 metrics.rmx_rttvar = tp->t_rttvar; 1456 metrics.rmx_cwnd = tp->snd_cwnd; 1457 metrics.rmx_sendpipe = 0; 1458 metrics.rmx_recvpipe = 0; 1459 1460 tcp_hc_update(&inp->inp_inc, &metrics); 1461 } 1462 1463 /* free the reassembly queue, if any */ 1464 tcp_reass_flush(tp); 1465 1466 #ifdef TCP_OFFLOAD 1467 /* Disconnect offload device, if any. */ 1468 if (tp->t_flags & TF_TOE) 1469 tcp_offload_detach(tp); 1470 #endif 1471 1472 tcp_free_sackholes(tp); 1473 1474 #ifdef TCPPCAP 1475 /* Free the TCP PCAP queues. */ 1476 tcp_pcap_drain(&(tp->t_inpkts)); 1477 tcp_pcap_drain(&(tp->t_outpkts)); 1478 #endif 1479 1480 /* Allow the CC algorithm to clean up after itself. */ 1481 if (CC_ALGO(tp)->cb_destroy != NULL) 1482 CC_ALGO(tp)->cb_destroy(tp->ccv); 1483 1484 #ifdef TCP_HHOOK 1485 khelp_destroy_osd(tp->osd); 1486 #endif 1487 1488 CC_ALGO(tp) = NULL; 1489 inp->inp_ppcb = NULL; 1490 if (tp->t_timers->tt_draincnt == 0) { 1491 /* We own the last reference on tcpcb, let's free it. */ 1492 TCPSTATES_DEC(tp->t_state); 1493 if (tp->t_fb->tfb_tcp_fb_fini) 1494 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1495 refcount_release(&tp->t_fb->tfb_refcnt); 1496 tp->t_inpcb = NULL; 1497 uma_zfree(V_tcpcb_zone, tp); 1498 released = in_pcbrele_wlocked(inp); 1499 KASSERT(!released, ("%s: inp %p should not have been released " 1500 "here", __func__, inp)); 1501 } 1502 } 1503 1504 void 1505 tcp_timer_discard(void *ptp) 1506 { 1507 struct inpcb *inp; 1508 struct tcpcb *tp; 1509 1510 tp = (struct tcpcb *)ptp; 1511 CURVNET_SET(tp->t_vnet); 1512 INP_INFO_RLOCK(&V_tcbinfo); 1513 inp = tp->t_inpcb; 1514 KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", 1515 __func__, tp)); 1516 INP_WLOCK(inp); 1517 KASSERT((tp->t_timers->tt_flags & TT_STOPPED) != 0, 1518 ("%s: tcpcb has to be stopped here", __func__)); 1519 tp->t_timers->tt_draincnt--; 1520 if (tp->t_timers->tt_draincnt == 0) { 1521 /* We own the last reference on this tcpcb, let's free it. */ 1522 TCPSTATES_DEC(tp->t_state); 1523 if (tp->t_fb->tfb_tcp_fb_fini) 1524 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1); 1525 refcount_release(&tp->t_fb->tfb_refcnt); 1526 tp->t_inpcb = NULL; 1527 uma_zfree(V_tcpcb_zone, tp); 1528 if (in_pcbrele_wlocked(inp)) { 1529 INP_INFO_RUNLOCK(&V_tcbinfo); 1530 CURVNET_RESTORE(); 1531 return; 1532 } 1533 } 1534 INP_WUNLOCK(inp); 1535 INP_INFO_RUNLOCK(&V_tcbinfo); 1536 CURVNET_RESTORE(); 1537 } 1538 1539 /* 1540 * Attempt to close a TCP control block, marking it as dropped, and freeing 1541 * the socket if we hold the only reference. 1542 */ 1543 struct tcpcb * 1544 tcp_close(struct tcpcb *tp) 1545 { 1546 struct inpcb *inp = tp->t_inpcb; 1547 struct socket *so; 1548 1549 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1550 INP_WLOCK_ASSERT(inp); 1551 1552 #ifdef TCP_OFFLOAD 1553 if (tp->t_state == TCPS_LISTEN) 1554 tcp_offload_listen_stop(tp); 1555 #endif 1556 #ifdef TCP_RFC7413 1557 /* 1558 * This releases the TFO pending counter resource for TFO listen 1559 * sockets as well as passively-created TFO sockets that transition 1560 * from SYN_RECEIVED to CLOSED. 1561 */ 1562 if (tp->t_tfo_pending) { 1563 tcp_fastopen_decrement_counter(tp->t_tfo_pending); 1564 tp->t_tfo_pending = NULL; 1565 } 1566 #endif 1567 in_pcbdrop(inp); 1568 TCPSTAT_INC(tcps_closed); 1569 if (tp->t_state != TCPS_CLOSED) 1570 tcp_state_change(tp, TCPS_CLOSED); 1571 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 1572 so = inp->inp_socket; 1573 soisdisconnected(so); 1574 if (inp->inp_flags & INP_SOCKREF) { 1575 KASSERT(so->so_state & SS_PROTOREF, 1576 ("tcp_close: !SS_PROTOREF")); 1577 inp->inp_flags &= ~INP_SOCKREF; 1578 INP_WUNLOCK(inp); 1579 ACCEPT_LOCK(); 1580 SOCK_LOCK(so); 1581 so->so_state &= ~SS_PROTOREF; 1582 sofree(so); 1583 return (NULL); 1584 } 1585 return (tp); 1586 } 1587 1588 void 1589 tcp_drain(void) 1590 { 1591 VNET_ITERATOR_DECL(vnet_iter); 1592 1593 if (!do_tcpdrain) 1594 return; 1595 1596 VNET_LIST_RLOCK_NOSLEEP(); 1597 VNET_FOREACH(vnet_iter) { 1598 CURVNET_SET(vnet_iter); 1599 struct inpcb *inpb; 1600 struct tcpcb *tcpb; 1601 1602 /* 1603 * Walk the tcpbs, if existing, and flush the reassembly queue, 1604 * if there is one... 1605 * XXX: The "Net/3" implementation doesn't imply that the TCP 1606 * reassembly queue should be flushed, but in a situation 1607 * where we're really low on mbufs, this is potentially 1608 * useful. 1609 */ 1610 INP_INFO_WLOCK(&V_tcbinfo); 1611 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 1612 if (inpb->inp_flags & INP_TIMEWAIT) 1613 continue; 1614 INP_WLOCK(inpb); 1615 if ((tcpb = intotcpcb(inpb)) != NULL) { 1616 tcp_reass_flush(tcpb); 1617 tcp_clean_sackreport(tcpb); 1618 #ifdef TCPPCAP 1619 if (tcp_pcap_aggressive_free) { 1620 /* Free the TCP PCAP queues. */ 1621 tcp_pcap_drain(&(tcpb->t_inpkts)); 1622 tcp_pcap_drain(&(tcpb->t_outpkts)); 1623 } 1624 #endif 1625 } 1626 INP_WUNLOCK(inpb); 1627 } 1628 INP_INFO_WUNLOCK(&V_tcbinfo); 1629 CURVNET_RESTORE(); 1630 } 1631 VNET_LIST_RUNLOCK_NOSLEEP(); 1632 } 1633 1634 /* 1635 * Notify a tcp user of an asynchronous error; 1636 * store error as soft error, but wake up user 1637 * (for now, won't do anything until can select for soft error). 1638 * 1639 * Do not wake up user since there currently is no mechanism for 1640 * reporting soft errors (yet - a kqueue filter may be added). 1641 */ 1642 static struct inpcb * 1643 tcp_notify(struct inpcb *inp, int error) 1644 { 1645 struct tcpcb *tp; 1646 1647 INP_INFO_LOCK_ASSERT(&V_tcbinfo); 1648 INP_WLOCK_ASSERT(inp); 1649 1650 if ((inp->inp_flags & INP_TIMEWAIT) || 1651 (inp->inp_flags & INP_DROPPED)) 1652 return (inp); 1653 1654 tp = intotcpcb(inp); 1655 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1656 1657 /* 1658 * Ignore some errors if we are hooked up. 1659 * If connection hasn't completed, has retransmitted several times, 1660 * and receives a second error, give up now. This is better 1661 * than waiting a long time to establish a connection that 1662 * can never complete. 1663 */ 1664 if (tp->t_state == TCPS_ESTABLISHED && 1665 (error == EHOSTUNREACH || error == ENETUNREACH || 1666 error == EHOSTDOWN)) { 1667 if (inp->inp_route.ro_rt) { 1668 RTFREE(inp->inp_route.ro_rt); 1669 inp->inp_route.ro_rt = (struct rtentry *)NULL; 1670 } 1671 return (inp); 1672 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1673 tp->t_softerror) { 1674 tp = tcp_drop(tp, error); 1675 if (tp != NULL) 1676 return (inp); 1677 else 1678 return (NULL); 1679 } else { 1680 tp->t_softerror = error; 1681 return (inp); 1682 } 1683 #if 0 1684 wakeup( &so->so_timeo); 1685 sorwakeup(so); 1686 sowwakeup(so); 1687 #endif 1688 } 1689 1690 static int 1691 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1692 { 1693 int error, i, m, n, pcb_count; 1694 struct inpcb *inp, **inp_list; 1695 inp_gen_t gencnt; 1696 struct xinpgen xig; 1697 1698 /* 1699 * The process of preparing the TCB list is too time-consuming and 1700 * resource-intensive to repeat twice on every request. 1701 */ 1702 if (req->oldptr == NULL) { 1703 n = V_tcbinfo.ipi_count + 1704 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1705 n += imax(n / 8, 10); 1706 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb); 1707 return (0); 1708 } 1709 1710 if (req->newptr != NULL) 1711 return (EPERM); 1712 1713 /* 1714 * OK, now we're committed to doing something. 1715 */ 1716 INP_LIST_RLOCK(&V_tcbinfo); 1717 gencnt = V_tcbinfo.ipi_gencnt; 1718 n = V_tcbinfo.ipi_count; 1719 INP_LIST_RUNLOCK(&V_tcbinfo); 1720 1721 m = counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]); 1722 1723 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1724 + (n + m) * sizeof(struct xtcpcb)); 1725 if (error != 0) 1726 return (error); 1727 1728 xig.xig_len = sizeof xig; 1729 xig.xig_count = n + m; 1730 xig.xig_gen = gencnt; 1731 xig.xig_sogen = so_gencnt; 1732 error = SYSCTL_OUT(req, &xig, sizeof xig); 1733 if (error) 1734 return (error); 1735 1736 error = syncache_pcblist(req, m, &pcb_count); 1737 if (error) 1738 return (error); 1739 1740 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1741 1742 INP_INFO_WLOCK(&V_tcbinfo); 1743 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1744 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1745 INP_WLOCK(inp); 1746 if (inp->inp_gencnt <= gencnt) { 1747 /* 1748 * XXX: This use of cr_cansee(), introduced with 1749 * TCP state changes, is not quite right, but for 1750 * now, better than nothing. 1751 */ 1752 if (inp->inp_flags & INP_TIMEWAIT) { 1753 if (intotw(inp) != NULL) 1754 error = cr_cansee(req->td->td_ucred, 1755 intotw(inp)->tw_cred); 1756 else 1757 error = EINVAL; /* Skip this inp. */ 1758 } else 1759 error = cr_canseeinpcb(req->td->td_ucred, inp); 1760 if (error == 0) { 1761 in_pcbref(inp); 1762 inp_list[i++] = inp; 1763 } 1764 } 1765 INP_WUNLOCK(inp); 1766 } 1767 INP_INFO_WUNLOCK(&V_tcbinfo); 1768 n = i; 1769 1770 error = 0; 1771 for (i = 0; i < n; i++) { 1772 inp = inp_list[i]; 1773 INP_RLOCK(inp); 1774 if (inp->inp_gencnt <= gencnt) { 1775 struct xtcpcb xt; 1776 1777 tcp_inptoxtp(inp, &xt); 1778 INP_RUNLOCK(inp); 1779 error = SYSCTL_OUT(req, &xt, sizeof xt); 1780 } else 1781 INP_RUNLOCK(inp); 1782 } 1783 INP_INFO_RLOCK(&V_tcbinfo); 1784 for (i = 0; i < n; i++) { 1785 inp = inp_list[i]; 1786 INP_RLOCK(inp); 1787 if (!in_pcbrele_rlocked(inp)) 1788 INP_RUNLOCK(inp); 1789 } 1790 INP_INFO_RUNLOCK(&V_tcbinfo); 1791 1792 if (!error) { 1793 /* 1794 * Give the user an updated idea of our state. 1795 * If the generation differs from what we told 1796 * her before, she knows that something happened 1797 * while we were processing this request, and it 1798 * might be necessary to retry. 1799 */ 1800 INP_LIST_RLOCK(&V_tcbinfo); 1801 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1802 xig.xig_sogen = so_gencnt; 1803 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1804 INP_LIST_RUNLOCK(&V_tcbinfo); 1805 error = SYSCTL_OUT(req, &xig, sizeof xig); 1806 } 1807 free(inp_list, M_TEMP); 1808 return (error); 1809 } 1810 1811 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, 1812 CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, 1813 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1814 1815 #ifdef INET 1816 static int 1817 tcp_getcred(SYSCTL_HANDLER_ARGS) 1818 { 1819 struct xucred xuc; 1820 struct sockaddr_in addrs[2]; 1821 struct inpcb *inp; 1822 int error; 1823 1824 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1825 if (error) 1826 return (error); 1827 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1828 if (error) 1829 return (error); 1830 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, 1831 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL); 1832 if (inp != NULL) { 1833 if (inp->inp_socket == NULL) 1834 error = ENOENT; 1835 if (error == 0) 1836 error = cr_canseeinpcb(req->td->td_ucred, inp); 1837 if (error == 0) 1838 cru2x(inp->inp_cred, &xuc); 1839 INP_RUNLOCK(inp); 1840 } else 1841 error = ENOENT; 1842 if (error == 0) 1843 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1844 return (error); 1845 } 1846 1847 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1848 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1849 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1850 #endif /* INET */ 1851 1852 #ifdef INET6 1853 static int 1854 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1855 { 1856 struct xucred xuc; 1857 struct sockaddr_in6 addrs[2]; 1858 struct inpcb *inp; 1859 int error; 1860 #ifdef INET 1861 int mapped = 0; 1862 #endif 1863 1864 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1865 if (error) 1866 return (error); 1867 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1868 if (error) 1869 return (error); 1870 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1871 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1872 return (error); 1873 } 1874 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1875 #ifdef INET 1876 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1877 mapped = 1; 1878 else 1879 #endif 1880 return (EINVAL); 1881 } 1882 1883 #ifdef INET 1884 if (mapped == 1) 1885 inp = in_pcblookup(&V_tcbinfo, 1886 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1887 addrs[1].sin6_port, 1888 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1889 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL); 1890 else 1891 #endif 1892 inp = in6_pcblookup(&V_tcbinfo, 1893 &addrs[1].sin6_addr, addrs[1].sin6_port, 1894 &addrs[0].sin6_addr, addrs[0].sin6_port, 1895 INPLOOKUP_RLOCKPCB, NULL); 1896 if (inp != NULL) { 1897 if (inp->inp_socket == NULL) 1898 error = ENOENT; 1899 if (error == 0) 1900 error = cr_canseeinpcb(req->td->td_ucred, inp); 1901 if (error == 0) 1902 cru2x(inp->inp_cred, &xuc); 1903 INP_RUNLOCK(inp); 1904 } else 1905 error = ENOENT; 1906 if (error == 0) 1907 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1908 return (error); 1909 } 1910 1911 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1912 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1913 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1914 #endif /* INET6 */ 1915 1916 1917 #ifdef INET 1918 void 1919 tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1920 { 1921 struct ip *ip = vip; 1922 struct tcphdr *th; 1923 struct in_addr faddr; 1924 struct inpcb *inp; 1925 struct tcpcb *tp; 1926 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1927 struct icmp *icp; 1928 struct in_conninfo inc; 1929 tcp_seq icmp_tcp_seq; 1930 int mtu; 1931 1932 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1933 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1934 return; 1935 1936 if (cmd == PRC_MSGSIZE) 1937 notify = tcp_mtudisc_notify; 1938 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1939 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 1940 cmd == PRC_TIMXCEED_INTRANS) && ip) 1941 notify = tcp_drop_syn_sent; 1942 1943 /* 1944 * Hostdead is ugly because it goes linearly through all PCBs. 1945 * XXX: We never get this from ICMP, otherwise it makes an 1946 * excellent DoS attack on machines with many connections. 1947 */ 1948 else if (cmd == PRC_HOSTDEAD) 1949 ip = NULL; 1950 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1951 return; 1952 1953 if (ip == NULL) { 1954 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1955 return; 1956 } 1957 1958 icp = (struct icmp *)((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1959 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 1960 INP_INFO_RLOCK(&V_tcbinfo); 1961 inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport, ip->ip_src, 1962 th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 1963 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 1964 /* signal EHOSTDOWN, as it flushes the cached route */ 1965 inp = (*notify)(inp, EHOSTDOWN); 1966 if (inp != NULL) 1967 INP_WUNLOCK(inp); 1968 } else if (inp != NULL) { 1969 if (!(inp->inp_flags & INP_TIMEWAIT) && 1970 !(inp->inp_flags & INP_DROPPED) && 1971 !(inp->inp_socket == NULL)) { 1972 icmp_tcp_seq = ntohl(th->th_seq); 1973 tp = intotcpcb(inp); 1974 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1975 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1976 if (cmd == PRC_MSGSIZE) { 1977 /* 1978 * MTU discovery: 1979 * If we got a needfrag set the MTU 1980 * in the route to the suggested new 1981 * value (if given) and then notify. 1982 */ 1983 mtu = ntohs(icp->icmp_nextmtu); 1984 /* 1985 * If no alternative MTU was 1986 * proposed, try the next smaller 1987 * one. 1988 */ 1989 if (!mtu) 1990 mtu = ip_next_mtu( 1991 ntohs(ip->ip_len), 1); 1992 if (mtu < V_tcp_minmss + 1993 sizeof(struct tcpiphdr)) 1994 mtu = V_tcp_minmss + 1995 sizeof(struct tcpiphdr); 1996 /* 1997 * Only process the offered MTU if it 1998 * is smaller than the current one. 1999 */ 2000 if (mtu < tp->t_maxseg + 2001 sizeof(struct tcpiphdr)) { 2002 bzero(&inc, sizeof(inc)); 2003 inc.inc_faddr = faddr; 2004 inc.inc_fibnum = 2005 inp->inp_inc.inc_fibnum; 2006 tcp_hc_updatemtu(&inc, mtu); 2007 tcp_mtudisc(inp, mtu); 2008 } 2009 } else 2010 inp = (*notify)(inp, 2011 inetctlerrmap[cmd]); 2012 } 2013 } 2014 if (inp != NULL) 2015 INP_WUNLOCK(inp); 2016 } else { 2017 bzero(&inc, sizeof(inc)); 2018 inc.inc_fport = th->th_dport; 2019 inc.inc_lport = th->th_sport; 2020 inc.inc_faddr = faddr; 2021 inc.inc_laddr = ip->ip_src; 2022 syncache_unreach(&inc, th); 2023 } 2024 INP_INFO_RUNLOCK(&V_tcbinfo); 2025 } 2026 #endif /* INET */ 2027 2028 #ifdef INET6 2029 void 2030 tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 2031 { 2032 struct in6_addr *dst; 2033 struct tcphdr *th; 2034 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 2035 struct ip6_hdr *ip6; 2036 struct mbuf *m; 2037 struct inpcb *inp; 2038 struct tcpcb *tp; 2039 struct icmp6_hdr *icmp6; 2040 struct ip6ctlparam *ip6cp = NULL; 2041 const struct sockaddr_in6 *sa6_src = NULL; 2042 struct in_conninfo inc; 2043 tcp_seq icmp_tcp_seq; 2044 unsigned int mtu; 2045 unsigned int off; 2046 2047 2048 if (sa->sa_family != AF_INET6 || 2049 sa->sa_len != sizeof(struct sockaddr_in6)) 2050 return; 2051 2052 /* if the parameter is from icmp6, decode it. */ 2053 if (d != NULL) { 2054 ip6cp = (struct ip6ctlparam *)d; 2055 icmp6 = ip6cp->ip6c_icmp6; 2056 m = ip6cp->ip6c_m; 2057 ip6 = ip6cp->ip6c_ip6; 2058 off = ip6cp->ip6c_off; 2059 sa6_src = ip6cp->ip6c_src; 2060 dst = ip6cp->ip6c_finaldst; 2061 } else { 2062 m = NULL; 2063 ip6 = NULL; 2064 off = 0; /* fool gcc */ 2065 sa6_src = &sa6_any; 2066 dst = NULL; 2067 } 2068 2069 if (cmd == PRC_MSGSIZE) 2070 notify = tcp_mtudisc_notify; 2071 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 2072 cmd == PRC_UNREACH_PORT || cmd == PRC_UNREACH_PROTOCOL || 2073 cmd == PRC_TIMXCEED_INTRANS) && ip6 != NULL) 2074 notify = tcp_drop_syn_sent; 2075 2076 /* 2077 * Hostdead is ugly because it goes linearly through all PCBs. 2078 * XXX: We never get this from ICMP, otherwise it makes an 2079 * excellent DoS attack on machines with many connections. 2080 */ 2081 else if (cmd == PRC_HOSTDEAD) 2082 ip6 = NULL; 2083 else if ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0) 2084 return; 2085 2086 if (ip6 == NULL) { 2087 in6_pcbnotify(&V_tcbinfo, sa, 0, 2088 (const struct sockaddr *)sa6_src, 2089 0, cmd, NULL, notify); 2090 return; 2091 } 2092 2093 /* Check if we can safely get the ports from the tcp hdr */ 2094 if (m == NULL || 2095 (m->m_pkthdr.len < 2096 (int32_t) (off + offsetof(struct tcphdr, th_seq)))) { 2097 return; 2098 } 2099 2100 th = (struct tcphdr *) mtodo(ip6cp->ip6c_m, ip6cp->ip6c_off); 2101 INP_INFO_RLOCK(&V_tcbinfo); 2102 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, th->th_dport, 2103 &ip6->ip6_src, th->th_sport, INPLOOKUP_WLOCKPCB, NULL); 2104 if (inp != NULL && PRC_IS_REDIRECT(cmd)) { 2105 /* signal EHOSTDOWN, as it flushes the cached route */ 2106 inp = (*notify)(inp, EHOSTDOWN); 2107 if (inp != NULL) 2108 INP_WUNLOCK(inp); 2109 } else if (inp != NULL) { 2110 if (!(inp->inp_flags & INP_TIMEWAIT) && 2111 !(inp->inp_flags & INP_DROPPED) && 2112 !(inp->inp_socket == NULL)) { 2113 icmp_tcp_seq = ntohl(th->th_seq); 2114 tp = intotcpcb(inp); 2115 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 2116 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 2117 if (cmd == PRC_MSGSIZE) { 2118 /* 2119 * MTU discovery: 2120 * If we got a needfrag set the MTU 2121 * in the route to the suggested new 2122 * value (if given) and then notify. 2123 */ 2124 mtu = ntohl(icmp6->icmp6_mtu); 2125 /* 2126 * If no alternative MTU was 2127 * proposed, or the proposed 2128 * MTU was too small, set to 2129 * the min. 2130 */ 2131 if (mtu < IPV6_MMTU) 2132 mtu = IPV6_MMTU - 8; 2133 2134 2135 bzero(&inc, sizeof(inc)); 2136 inc.inc_fibnum = M_GETFIB(m); 2137 inc.inc_flags |= INC_ISIPV6; 2138 inc.inc6_faddr = *dst; 2139 if (in6_setscope(&inc.inc6_faddr, 2140 m->m_pkthdr.rcvif, NULL)) 2141 goto unlock_inp; 2142 2143 /* 2144 * Only process the offered MTU if it 2145 * is smaller than the current one. 2146 */ 2147 if (mtu < tp->t_maxseg + 2148 (sizeof (*th) + sizeof (*ip6))) { 2149 tcp_hc_updatemtu(&inc, mtu); 2150 tcp_mtudisc(inp, mtu); 2151 ICMP6STAT_INC(icp6s_pmtuchg); 2152 } 2153 } else 2154 inp = (*notify)(inp, 2155 inet6ctlerrmap[cmd]); 2156 } 2157 } 2158 unlock_inp: 2159 if (inp != NULL) 2160 INP_WUNLOCK(inp); 2161 } else { 2162 bzero(&inc, sizeof(inc)); 2163 inc.inc_fibnum = M_GETFIB(m); 2164 inc.inc_flags |= INC_ISIPV6; 2165 inc.inc_fport = th->th_dport; 2166 inc.inc_lport = th->th_sport; 2167 inc.inc6_faddr = *dst; 2168 inc.inc6_laddr = ip6->ip6_src; 2169 syncache_unreach(&inc, th); 2170 } 2171 INP_INFO_RUNLOCK(&V_tcbinfo); 2172 } 2173 #endif /* INET6 */ 2174 2175 2176 /* 2177 * Following is where TCP initial sequence number generation occurs. 2178 * 2179 * There are two places where we must use initial sequence numbers: 2180 * 1. In SYN-ACK packets. 2181 * 2. In SYN packets. 2182 * 2183 * All ISNs for SYN-ACK packets are generated by the syncache. See 2184 * tcp_syncache.c for details. 2185 * 2186 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 2187 * depends on this property. In addition, these ISNs should be 2188 * unguessable so as to prevent connection hijacking. To satisfy 2189 * the requirements of this situation, the algorithm outlined in 2190 * RFC 1948 is used, with only small modifications. 2191 * 2192 * Implementation details: 2193 * 2194 * Time is based off the system timer, and is corrected so that it 2195 * increases by one megabyte per second. This allows for proper 2196 * recycling on high speed LANs while still leaving over an hour 2197 * before rollover. 2198 * 2199 * As reading the *exact* system time is too expensive to be done 2200 * whenever setting up a TCP connection, we increment the time 2201 * offset in two ways. First, a small random positive increment 2202 * is added to isn_offset for each connection that is set up. 2203 * Second, the function tcp_isn_tick fires once per clock tick 2204 * and increments isn_offset as necessary so that sequence numbers 2205 * are incremented at approximately ISN_BYTES_PER_SECOND. The 2206 * random positive increments serve only to ensure that the same 2207 * exact sequence number is never sent out twice (as could otherwise 2208 * happen when a port is recycled in less than the system tick 2209 * interval.) 2210 * 2211 * net.inet.tcp.isn_reseed_interval controls the number of seconds 2212 * between seeding of isn_secret. This is normally set to zero, 2213 * as reseeding should not be necessary. 2214 * 2215 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 2216 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 2217 * general, this means holding an exclusive (write) lock. 2218 */ 2219 2220 #define ISN_BYTES_PER_SECOND 1048576 2221 #define ISN_STATIC_INCREMENT 4096 2222 #define ISN_RANDOM_INCREMENT (4096 - 1) 2223 2224 static VNET_DEFINE(u_char, isn_secret[32]); 2225 static VNET_DEFINE(int, isn_last); 2226 static VNET_DEFINE(int, isn_last_reseed); 2227 static VNET_DEFINE(u_int32_t, isn_offset); 2228 static VNET_DEFINE(u_int32_t, isn_offset_old); 2229 2230 #define V_isn_secret VNET(isn_secret) 2231 #define V_isn_last VNET(isn_last) 2232 #define V_isn_last_reseed VNET(isn_last_reseed) 2233 #define V_isn_offset VNET(isn_offset) 2234 #define V_isn_offset_old VNET(isn_offset_old) 2235 2236 tcp_seq 2237 tcp_new_isn(struct tcpcb *tp) 2238 { 2239 MD5_CTX isn_ctx; 2240 u_int32_t md5_buffer[4]; 2241 tcp_seq new_isn; 2242 u_int32_t projected_offset; 2243 2244 INP_WLOCK_ASSERT(tp->t_inpcb); 2245 2246 ISN_LOCK(); 2247 /* Seed if this is the first use, reseed if requested. */ 2248 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 2249 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 2250 < (u_int)ticks))) { 2251 read_random(&V_isn_secret, sizeof(V_isn_secret)); 2252 V_isn_last_reseed = ticks; 2253 } 2254 2255 /* Compute the md5 hash and return the ISN. */ 2256 MD5Init(&isn_ctx); 2257 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 2258 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 2259 #ifdef INET6 2260 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 2261 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 2262 sizeof(struct in6_addr)); 2263 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 2264 sizeof(struct in6_addr)); 2265 } else 2266 #endif 2267 { 2268 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 2269 sizeof(struct in_addr)); 2270 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 2271 sizeof(struct in_addr)); 2272 } 2273 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 2274 MD5Final((u_char *) &md5_buffer, &isn_ctx); 2275 new_isn = (tcp_seq) md5_buffer[0]; 2276 V_isn_offset += ISN_STATIC_INCREMENT + 2277 (arc4random() & ISN_RANDOM_INCREMENT); 2278 if (ticks != V_isn_last) { 2279 projected_offset = V_isn_offset_old + 2280 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last); 2281 if (SEQ_GT(projected_offset, V_isn_offset)) 2282 V_isn_offset = projected_offset; 2283 V_isn_offset_old = V_isn_offset; 2284 V_isn_last = ticks; 2285 } 2286 new_isn += V_isn_offset; 2287 ISN_UNLOCK(); 2288 return (new_isn); 2289 } 2290 2291 /* 2292 * When a specific ICMP unreachable message is received and the 2293 * connection state is SYN-SENT, drop the connection. This behavior 2294 * is controlled by the icmp_may_rst sysctl. 2295 */ 2296 struct inpcb * 2297 tcp_drop_syn_sent(struct inpcb *inp, int errno) 2298 { 2299 struct tcpcb *tp; 2300 2301 INP_INFO_RLOCK_ASSERT(&V_tcbinfo); 2302 INP_WLOCK_ASSERT(inp); 2303 2304 if ((inp->inp_flags & INP_TIMEWAIT) || 2305 (inp->inp_flags & INP_DROPPED)) 2306 return (inp); 2307 2308 tp = intotcpcb(inp); 2309 if (tp->t_state != TCPS_SYN_SENT) 2310 return (inp); 2311 2312 tp = tcp_drop(tp, errno); 2313 if (tp != NULL) 2314 return (inp); 2315 else 2316 return (NULL); 2317 } 2318 2319 /* 2320 * When `need fragmentation' ICMP is received, update our idea of the MSS 2321 * based on the new value. Also nudge TCP to send something, since we 2322 * know the packet we just sent was dropped. 2323 * This duplicates some code in the tcp_mss() function in tcp_input.c. 2324 */ 2325 static struct inpcb * 2326 tcp_mtudisc_notify(struct inpcb *inp, int error) 2327 { 2328 2329 tcp_mtudisc(inp, -1); 2330 return (inp); 2331 } 2332 2333 static void 2334 tcp_mtudisc(struct inpcb *inp, int mtuoffer) 2335 { 2336 struct tcpcb *tp; 2337 struct socket *so; 2338 2339 INP_WLOCK_ASSERT(inp); 2340 if ((inp->inp_flags & INP_TIMEWAIT) || 2341 (inp->inp_flags & INP_DROPPED)) 2342 return; 2343 2344 tp = intotcpcb(inp); 2345 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 2346 2347 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL); 2348 2349 so = inp->inp_socket; 2350 SOCKBUF_LOCK(&so->so_snd); 2351 /* If the mss is larger than the socket buffer, decrease the mss. */ 2352 if (so->so_snd.sb_hiwat < tp->t_maxseg) 2353 tp->t_maxseg = so->so_snd.sb_hiwat; 2354 SOCKBUF_UNLOCK(&so->so_snd); 2355 2356 TCPSTAT_INC(tcps_mturesent); 2357 tp->t_rtttime = 0; 2358 tp->snd_nxt = tp->snd_una; 2359 tcp_free_sackholes(tp); 2360 tp->snd_recover = tp->snd_max; 2361 if (tp->t_flags & TF_SACK_PERMIT) 2362 EXIT_FASTRECOVERY(tp->t_flags); 2363 tp->t_fb->tfb_tcp_output(tp); 2364 } 2365 2366 #ifdef INET 2367 /* 2368 * Look-up the routing entry to the peer of this inpcb. If no route 2369 * is found and it cannot be allocated, then return 0. This routine 2370 * is called by TCP routines that access the rmx structure and by 2371 * tcp_mss_update to get the peer/interface MTU. 2372 */ 2373 uint32_t 2374 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) 2375 { 2376 struct nhop4_extended nh4; 2377 struct ifnet *ifp; 2378 uint32_t maxmtu = 0; 2379 2380 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 2381 2382 if (inc->inc_faddr.s_addr != INADDR_ANY) { 2383 2384 if (fib4_lookup_nh_ext(inc->inc_fibnum, inc->inc_faddr, 2385 NHR_REF, 0, &nh4) != 0) 2386 return (0); 2387 2388 ifp = nh4.nh_ifp; 2389 maxmtu = nh4.nh_mtu; 2390 2391 /* Report additional interface capabilities. */ 2392 if (cap != NULL) { 2393 if (ifp->if_capenable & IFCAP_TSO4 && 2394 ifp->if_hwassist & CSUM_TSO) { 2395 cap->ifcap |= CSUM_TSO; 2396 cap->tsomax = ifp->if_hw_tsomax; 2397 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2398 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2399 } 2400 } 2401 fib4_free_nh_ext(inc->inc_fibnum, &nh4); 2402 } 2403 return (maxmtu); 2404 } 2405 #endif /* INET */ 2406 2407 #ifdef INET6 2408 uint32_t 2409 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) 2410 { 2411 struct nhop6_extended nh6; 2412 struct in6_addr dst6; 2413 uint32_t scopeid; 2414 struct ifnet *ifp; 2415 uint32_t maxmtu = 0; 2416 2417 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 2418 2419 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 2420 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid); 2421 if (fib6_lookup_nh_ext(inc->inc_fibnum, &dst6, scopeid, 0, 2422 0, &nh6) != 0) 2423 return (0); 2424 2425 ifp = nh6.nh_ifp; 2426 maxmtu = nh6.nh_mtu; 2427 2428 /* Report additional interface capabilities. */ 2429 if (cap != NULL) { 2430 if (ifp->if_capenable & IFCAP_TSO6 && 2431 ifp->if_hwassist & CSUM_TSO) { 2432 cap->ifcap |= CSUM_TSO; 2433 cap->tsomax = ifp->if_hw_tsomax; 2434 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount; 2435 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize; 2436 } 2437 } 2438 fib6_free_nh_ext(inc->inc_fibnum, &nh6); 2439 } 2440 2441 return (maxmtu); 2442 } 2443 #endif /* INET6 */ 2444 2445 /* 2446 * Calculate effective SMSS per RFC5681 definition for a given TCP 2447 * connection at its current state, taking into account SACK and etc. 2448 */ 2449 u_int 2450 tcp_maxseg(const struct tcpcb *tp) 2451 { 2452 u_int optlen; 2453 2454 if (tp->t_flags & TF_NOOPT) 2455 return (tp->t_maxseg); 2456 2457 /* 2458 * Here we have a simplified code from tcp_addoptions(), 2459 * without a proper loop, and having most of paddings hardcoded. 2460 * We might make mistakes with padding here in some edge cases, 2461 * but this is harmless, since result of tcp_maxseg() is used 2462 * only in cwnd and ssthresh estimations. 2463 */ 2464 #define PAD(len) ((((len) / 4) + !!((len) % 4)) * 4) 2465 if (TCPS_HAVEESTABLISHED(tp->t_state)) { 2466 if (tp->t_flags & TF_RCVD_TSTMP) 2467 optlen = TCPOLEN_TSTAMP_APPA; 2468 else 2469 optlen = 0; 2470 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2471 if (tp->t_flags & TF_SIGNATURE) 2472 optlen += PAD(TCPOLEN_SIGNATURE); 2473 #endif 2474 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) { 2475 optlen += TCPOLEN_SACKHDR; 2476 optlen += tp->rcv_numsacks * TCPOLEN_SACK; 2477 optlen = PAD(optlen); 2478 } 2479 } else { 2480 if (tp->t_flags & TF_REQ_TSTMP) 2481 optlen = TCPOLEN_TSTAMP_APPA; 2482 else 2483 optlen = PAD(TCPOLEN_MAXSEG); 2484 if (tp->t_flags & TF_REQ_SCALE) 2485 optlen += PAD(TCPOLEN_WINDOW); 2486 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE) 2487 if (tp->t_flags & TF_SIGNATURE) 2488 optlen += PAD(TCPOLEN_SIGNATURE); 2489 #endif 2490 if (tp->t_flags & TF_SACK_PERMIT) 2491 optlen += PAD(TCPOLEN_SACK_PERMITTED); 2492 } 2493 #undef PAD 2494 optlen = min(optlen, TCP_MAXOLEN); 2495 return (tp->t_maxseg - optlen); 2496 } 2497 2498 static int 2499 sysctl_drop(SYSCTL_HANDLER_ARGS) 2500 { 2501 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2502 struct sockaddr_storage addrs[2]; 2503 struct inpcb *inp; 2504 struct tcpcb *tp; 2505 struct tcptw *tw; 2506 struct sockaddr_in *fin, *lin; 2507 #ifdef INET6 2508 struct sockaddr_in6 *fin6, *lin6; 2509 #endif 2510 int error; 2511 2512 inp = NULL; 2513 fin = lin = NULL; 2514 #ifdef INET6 2515 fin6 = lin6 = NULL; 2516 #endif 2517 error = 0; 2518 2519 if (req->oldptr != NULL || req->oldlen != 0) 2520 return (EINVAL); 2521 if (req->newptr == NULL) 2522 return (EPERM); 2523 if (req->newlen < sizeof(addrs)) 2524 return (ENOMEM); 2525 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2526 if (error) 2527 return (error); 2528 2529 switch (addrs[0].ss_family) { 2530 #ifdef INET6 2531 case AF_INET6: 2532 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2533 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2534 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2535 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2536 return (EINVAL); 2537 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2538 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2539 return (EINVAL); 2540 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2541 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2542 fin = (struct sockaddr_in *)&addrs[0]; 2543 lin = (struct sockaddr_in *)&addrs[1]; 2544 break; 2545 } 2546 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2547 if (error) 2548 return (error); 2549 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2550 if (error) 2551 return (error); 2552 break; 2553 #endif 2554 #ifdef INET 2555 case AF_INET: 2556 fin = (struct sockaddr_in *)&addrs[0]; 2557 lin = (struct sockaddr_in *)&addrs[1]; 2558 if (fin->sin_len != sizeof(struct sockaddr_in) || 2559 lin->sin_len != sizeof(struct sockaddr_in)) 2560 return (EINVAL); 2561 break; 2562 #endif 2563 default: 2564 return (EINVAL); 2565 } 2566 INP_INFO_RLOCK(&V_tcbinfo); 2567 switch (addrs[0].ss_family) { 2568 #ifdef INET6 2569 case AF_INET6: 2570 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr, 2571 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 2572 INPLOOKUP_WLOCKPCB, NULL); 2573 break; 2574 #endif 2575 #ifdef INET 2576 case AF_INET: 2577 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port, 2578 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL); 2579 break; 2580 #endif 2581 } 2582 if (inp != NULL) { 2583 if (inp->inp_flags & INP_TIMEWAIT) { 2584 /* 2585 * XXXRW: There currently exists a state where an 2586 * inpcb is present, but its timewait state has been 2587 * discarded. For now, don't allow dropping of this 2588 * type of inpcb. 2589 */ 2590 tw = intotw(inp); 2591 if (tw != NULL) 2592 tcp_twclose(tw, 0); 2593 else 2594 INP_WUNLOCK(inp); 2595 } else if (!(inp->inp_flags & INP_DROPPED) && 2596 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2597 tp = intotcpcb(inp); 2598 tp = tcp_drop(tp, ECONNABORTED); 2599 if (tp != NULL) 2600 INP_WUNLOCK(inp); 2601 } else 2602 INP_WUNLOCK(inp); 2603 } else 2604 error = ESRCH; 2605 INP_INFO_RUNLOCK(&V_tcbinfo); 2606 return (error); 2607 } 2608 2609 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2610 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 2611 0, sysctl_drop, "", "Drop TCP connection"); 2612 2613 /* 2614 * Generate a standardized TCP log line for use throughout the 2615 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2616 * allow use in the interrupt context. 2617 * 2618 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2619 * NB: The function may return NULL if memory allocation failed. 2620 * 2621 * Due to header inclusion and ordering limitations the struct ip 2622 * and ip6_hdr pointers have to be passed as void pointers. 2623 */ 2624 char * 2625 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2626 const void *ip6hdr) 2627 { 2628 2629 /* Is logging enabled? */ 2630 if (tcp_log_in_vain == 0) 2631 return (NULL); 2632 2633 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2634 } 2635 2636 char * 2637 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2638 const void *ip6hdr) 2639 { 2640 2641 /* Is logging enabled? */ 2642 if (tcp_log_debug == 0) 2643 return (NULL); 2644 2645 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr)); 2646 } 2647 2648 static char * 2649 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2650 const void *ip6hdr) 2651 { 2652 char *s, *sp; 2653 size_t size; 2654 struct ip *ip; 2655 #ifdef INET6 2656 const struct ip6_hdr *ip6; 2657 2658 ip6 = (const struct ip6_hdr *)ip6hdr; 2659 #endif /* INET6 */ 2660 ip = (struct ip *)ip4hdr; 2661 2662 /* 2663 * The log line looks like this: 2664 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2665 */ 2666 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2667 sizeof(PRINT_TH_FLAGS) + 1 + 2668 #ifdef INET6 2669 2 * INET6_ADDRSTRLEN; 2670 #else 2671 2 * INET_ADDRSTRLEN; 2672 #endif /* INET6 */ 2673 2674 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2675 if (s == NULL) 2676 return (NULL); 2677 2678 strcat(s, "TCP: ["); 2679 sp = s + strlen(s); 2680 2681 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2682 inet_ntoa_r(inc->inc_faddr, sp); 2683 sp = s + strlen(s); 2684 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2685 sp = s + strlen(s); 2686 inet_ntoa_r(inc->inc_laddr, sp); 2687 sp = s + strlen(s); 2688 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2689 #ifdef INET6 2690 } else if (inc) { 2691 ip6_sprintf(sp, &inc->inc6_faddr); 2692 sp = s + strlen(s); 2693 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2694 sp = s + strlen(s); 2695 ip6_sprintf(sp, &inc->inc6_laddr); 2696 sp = s + strlen(s); 2697 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2698 } else if (ip6 && th) { 2699 ip6_sprintf(sp, &ip6->ip6_src); 2700 sp = s + strlen(s); 2701 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2702 sp = s + strlen(s); 2703 ip6_sprintf(sp, &ip6->ip6_dst); 2704 sp = s + strlen(s); 2705 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2706 #endif /* INET6 */ 2707 #ifdef INET 2708 } else if (ip && th) { 2709 inet_ntoa_r(ip->ip_src, sp); 2710 sp = s + strlen(s); 2711 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2712 sp = s + strlen(s); 2713 inet_ntoa_r(ip->ip_dst, sp); 2714 sp = s + strlen(s); 2715 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2716 #endif /* INET */ 2717 } else { 2718 free(s, M_TCPLOG); 2719 return (NULL); 2720 } 2721 sp = s + strlen(s); 2722 if (th) 2723 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2724 if (*(s + size - 1) != '\0') 2725 panic("%s: string too long", __func__); 2726 return (s); 2727 } 2728 2729 /* 2730 * A subroutine which makes it easy to track TCP state changes with DTrace. 2731 * This function shouldn't be called for t_state initializations that don't 2732 * correspond to actual TCP state transitions. 2733 */ 2734 void 2735 tcp_state_change(struct tcpcb *tp, int newstate) 2736 { 2737 #if defined(KDTRACE_HOOKS) 2738 int pstate = tp->t_state; 2739 #endif 2740 2741 TCPSTATES_DEC(tp->t_state); 2742 TCPSTATES_INC(newstate); 2743 tp->t_state = newstate; 2744 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate); 2745 } 2746 2747 /* 2748 * Create an external-format (``xtcpcb'') structure using the information in 2749 * the kernel-format tcpcb structure pointed to by tp. This is done to 2750 * reduce the spew of irrelevant information over this interface, to isolate 2751 * user code from changes in the kernel structure, and potentially to provide 2752 * information-hiding if we decide that some of this information should be 2753 * hidden from users. 2754 */ 2755 void 2756 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt) 2757 { 2758 struct tcpcb *tp = intotcpcb(inp); 2759 sbintime_t now; 2760 2761 if (inp->inp_flags & INP_TIMEWAIT) { 2762 bzero(xt, sizeof(struct xtcpcb)); 2763 xt->t_state = TCPS_TIME_WAIT; 2764 } else { 2765 xt->t_state = tp->t_state; 2766 xt->t_flags = tp->t_flags; 2767 xt->t_sndzerowin = tp->t_sndzerowin; 2768 xt->t_sndrexmitpack = tp->t_sndrexmitpack; 2769 xt->t_rcvoopack = tp->t_rcvoopack; 2770 2771 now = getsbinuptime(); 2772 #define COPYTIMER(ttt) do { \ 2773 if (callout_active(&tp->t_timers->ttt)) \ 2774 xt->ttt = (tp->t_timers->ttt.c_time - now) / \ 2775 SBT_1MS; \ 2776 else \ 2777 xt->ttt = 0; \ 2778 } while (0) 2779 COPYTIMER(tt_delack); 2780 COPYTIMER(tt_rexmt); 2781 COPYTIMER(tt_persist); 2782 COPYTIMER(tt_keep); 2783 COPYTIMER(tt_2msl); 2784 #undef COPYTIMER 2785 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz; 2786 2787 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack, 2788 TCP_FUNCTION_NAME_LEN_MAX); 2789 } 2790 2791 xt->xt_len = sizeof(struct xtcpcb); 2792 in_pcbtoxinpcb(inp, &xt->xt_inp); 2793 if (inp->inp_socket == NULL) 2794 xt->xt_inp.xi_socket.xso_protocol = IPPROTO_TCP; 2795 } 2796