1 /* 2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. 3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Jeffrey M. Hsu. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of The DragonFly Project nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific, prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 36 * The Regents of the University of California. All rights reserved. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the University of 49 * California, Berkeley and its contributors. 50 * 4. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 67 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $ 68 */ 69 70 #include "opt_compat.h" 71 #include "opt_inet.h" 72 #include "opt_inet6.h" 73 #include "opt_ipsec.h" 74 #include "opt_tcpdebug.h" 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/callout.h> 79 #include <sys/kernel.h> 80 #include <sys/sysctl.h> 81 #include <sys/malloc.h> 82 #include <sys/mpipe.h> 83 #include <sys/mbuf.h> 84 #ifdef INET6 85 #include <sys/domain.h> 86 #endif 87 #include <sys/proc.h> 88 #include <sys/priv.h> 89 #include <sys/socket.h> 90 #include <sys/socketops.h> 91 #include <sys/socketvar.h> 92 #include <sys/protosw.h> 93 #include <sys/random.h> 94 #include <sys/in_cksum.h> 95 #include <sys/ktr.h> 96 97 #include <net/route.h> 98 #include <net/if.h> 99 #include <net/netisr.h> 100 101 #define _IP_VHL 102 #include <netinet/in.h> 103 #include <netinet/in_systm.h> 104 #include <netinet/ip.h> 105 #include <netinet/ip6.h> 106 #include <netinet/in_pcb.h> 107 #include <netinet6/in6_pcb.h> 108 #include <netinet/in_var.h> 109 #include <netinet/ip_var.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet/ip_icmp.h> 112 #ifdef INET6 113 #include <netinet/icmp6.h> 114 #endif 115 #include <netinet/tcp.h> 116 #include <netinet/tcp_fsm.h> 117 #include <netinet/tcp_seq.h> 118 #include <netinet/tcp_timer.h> 119 #include <netinet/tcp_timer2.h> 120 #include <netinet/tcp_var.h> 121 #include <netinet6/tcp6_var.h> 122 #include <netinet/tcpip.h> 123 #ifdef TCPDEBUG 124 #include <netinet/tcp_debug.h> 125 #endif 126 #include <netinet6/ip6protosw.h> 127 128 #ifdef IPSEC 129 #include <netinet6/ipsec.h> 130 #include <netproto/key/key.h> 131 #ifdef INET6 132 #include <netinet6/ipsec6.h> 133 #endif 134 #endif 135 136 #ifdef FAST_IPSEC 137 #include <netproto/ipsec/ipsec.h> 138 #ifdef INET6 139 #include <netproto/ipsec/ipsec6.h> 140 #endif 141 #define IPSEC 142 #endif 143 144 #include <sys/md5.h> 145 #include <machine/smp.h> 146 147 #include <sys/msgport2.h> 148 #include <sys/mplock2.h> 149 #include <net/netmsg2.h> 150 151 #if !defined(KTR_TCP) 152 #define KTR_TCP KTR_ALL 153 #endif 154 /* 155 KTR_INFO_MASTER(tcp); 156 KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); 157 KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); 158 KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); 159 #define logtcp(name) KTR_LOG(tcp_ ## name) 160 */ 161 162 #define TCP_IW_MAXSEGS_DFLT 4 163 #define TCP_IW_CAPSEGS_DFLT 3 164 165 struct inpcbinfo tcbinfo[MAXCPU]; 166 struct tcpcbackqhead tcpcbackq[MAXCPU]; 167 168 static struct lwkt_token tcp_port_token = 169 LWKT_TOKEN_INITIALIZER(tcp_port_token); 170 171 int tcp_mssdflt = TCP_MSS; 172 SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, 173 &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); 174 175 #ifdef INET6 176 int tcp_v6mssdflt = TCP6_MSS; 177 SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, 178 &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); 179 #endif 180 181 /* 182 * Minimum MSS we accept and use. This prevents DoS attacks where 183 * we are forced to a ridiculous low MSS like 20 and send hundreds 184 * of packets instead of one. The effect scales with the available 185 * bandwidth and quickly saturates the CPU and network interface 186 * with packet generation and sending. Set to zero to disable MINMSS 187 * checking. This setting prevents us from sending too small packets. 188 */ 189 int tcp_minmss = TCP_MINMSS; 190 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, 191 &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); 192 193 #if 0 194 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 195 SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, 196 &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); 197 #endif 198 199 int tcp_do_rfc1323 = 1; 200 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, 201 &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); 202 203 static int tcp_tcbhashsize = 0; 204 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, 205 &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); 206 207 static int do_tcpdrain = 1; 208 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, 209 "Enable tcp_drain routine for extra help when low on mbufs"); 210 211 static int icmp_may_rst = 1; 212 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, 213 "Certain ICMP unreachable messages may abort connections in SYN_SENT"); 214 215 static int tcp_isn_reseed_interval = 0; 216 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, 217 &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); 218 219 /* 220 * TCP bandwidth limiting sysctls. The inflight limiter is now turned on 221 * by default, but with generous values which should allow maximal 222 * bandwidth. In particular, the slop defaults to 50 (5 packets). 223 * 224 * The reason for doing this is that the limiter is the only mechanism we 225 * have which seems to do a really good job preventing receiver RX rings 226 * on network interfaces from getting blown out. Even though GigE/10GigE 227 * is supposed to flow control it looks like either it doesn't actually 228 * do it or Open Source drivers do not properly enable it. 229 * 230 * People using the limiter to reduce bottlenecks on slower WAN connections 231 * should set the slop to 20 (2 packets). 232 */ 233 static int tcp_inflight_enable = 1; 234 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, 235 &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); 236 237 static int tcp_inflight_debug = 0; 238 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, 239 &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); 240 241 static int tcp_inflight_min = 6144; 242 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, 243 &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); 244 245 static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; 246 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, 247 &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); 248 249 static int tcp_inflight_stab = 50; 250 SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, 251 &tcp_inflight_stab, 0, "Slop in maximal packets / 10 (20 = 3 packets)"); 252 253 static int tcp_do_rfc3390 = 1; 254 SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW, 255 &tcp_do_rfc3390, 0, 256 "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)"); 257 258 static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 259 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW, 260 &tcp_iw_maxsegs, 0, "TCP IW segments max"); 261 262 static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 263 SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW, 264 &tcp_iw_capsegs, 0, "TCP IW segments"); 265 266 int tcp_low_rtobase = 1; 267 SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW, 268 &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)"); 269 270 static int tcp_do_ncr = 1; 271 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW, 272 &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)"); 273 274 static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); 275 static struct malloc_pipe tcptemp_mpipe; 276 277 static void tcp_willblock(void); 278 static void tcp_notify (struct inpcb *, int); 279 280 struct tcp_stats tcpstats_percpu[MAXCPU]; 281 282 static int 283 sysctl_tcpstats(SYSCTL_HANDLER_ARGS) 284 { 285 int cpu, error = 0; 286 287 for (cpu = 0; cpu < ncpus; ++cpu) { 288 if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], 289 sizeof(struct tcp_stats)))) 290 break; 291 if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], 292 sizeof(struct tcp_stats)))) 293 break; 294 } 295 296 return (error); 297 } 298 SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 299 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); 300 301 /* 302 * Target size of TCP PCB hash tables. Must be a power of two. 303 * 304 * Note that this can be overridden by the kernel environment 305 * variable net.inet.tcp.tcbhashsize 306 */ 307 #ifndef TCBHASHSIZE 308 #define TCBHASHSIZE 512 309 #endif 310 311 /* 312 * This is the actual shape of what we allocate using the zone 313 * allocator. Doing it this way allows us to protect both structures 314 * using the same generation count, and also eliminates the overhead 315 * of allocating tcpcbs separately. By hiding the structure here, 316 * we avoid changing most of the rest of the code (although it needs 317 * to be changed, eventually, for greater efficiency). 318 */ 319 #define ALIGNMENT 32 320 #define ALIGNM1 (ALIGNMENT - 1) 321 struct inp_tp { 322 union { 323 struct inpcb inp; 324 char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; 325 } inp_tp_u; 326 struct tcpcb tcb; 327 struct tcp_callout inp_tp_rexmt; 328 struct tcp_callout inp_tp_persist; 329 struct tcp_callout inp_tp_keep; 330 struct tcp_callout inp_tp_2msl; 331 struct tcp_callout inp_tp_delack; 332 struct netmsg_tcp_timer inp_tp_timermsg; 333 }; 334 #undef ALIGNMENT 335 #undef ALIGNM1 336 337 /* 338 * Tcp initialization 339 */ 340 void 341 tcp_init(void) 342 { 343 struct inpcbporthead *porthashbase; 344 struct inpcbinfo *ticb; 345 u_long porthashmask; 346 int hashsize = TCBHASHSIZE; 347 int cpu; 348 349 /* 350 * note: tcptemp is used for keepalives, and it is ok for an 351 * allocation to fail so do not specify MPF_INT. 352 */ 353 mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 354 25, -1, 0, NULL, NULL, NULL); 355 356 tcp_delacktime = TCPTV_DELACK; 357 tcp_keepinit = TCPTV_KEEP_INIT; 358 tcp_keepidle = TCPTV_KEEP_IDLE; 359 tcp_keepintvl = TCPTV_KEEPINTVL; 360 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 361 tcp_msl = TCPTV_MSL; 362 tcp_rexmit_min = TCPTV_MIN; 363 tcp_rexmit_slop = TCPTV_CPU_VAR; 364 365 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); 366 if (!powerof2(hashsize)) { 367 kprintf("WARNING: TCB hash size not a power of 2\n"); 368 hashsize = 512; /* safe default */ 369 } 370 tcp_tcbhashsize = hashsize; 371 porthashbase = hashinit(hashsize, M_PCB, &porthashmask); 372 373 for (cpu = 0; cpu < ncpus2; cpu++) { 374 ticb = &tcbinfo[cpu]; 375 in_pcbinfo_init(ticb); 376 ticb->cpu = cpu; 377 ticb->hashbase = hashinit(hashsize, M_PCB, 378 &ticb->hashmask); 379 ticb->porthashbase = porthashbase; 380 ticb->porthashmask = porthashmask; 381 ticb->porttoken = &tcp_port_token; 382 #if 0 383 ticb->porthashbase = hashinit(hashsize, M_PCB, 384 &ticb->porthashmask); 385 #endif 386 ticb->wildcardhashbase = hashinit(hashsize, M_PCB, 387 &ticb->wildcardhashmask); 388 ticb->ipi_size = sizeof(struct inp_tp); 389 TAILQ_INIT(&tcpcbackq[cpu]); 390 } 391 392 tcp_reass_maxseg = nmbclusters / 16; 393 TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); 394 395 #ifdef INET6 396 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 397 #else 398 #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 399 #endif 400 if (max_protohdr < TCP_MINPROTOHDR) 401 max_protohdr = TCP_MINPROTOHDR; 402 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 403 panic("tcp_init"); 404 #undef TCP_MINPROTOHDR 405 406 /* 407 * Initialize TCP statistics counters for each CPU. 408 */ 409 for (cpu = 0; cpu < ncpus; ++cpu) { 410 bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); 411 } 412 413 syncache_init(); 414 netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP); 415 } 416 417 static void 418 tcp_willblock(void) 419 { 420 struct tcpcb *tp; 421 int cpu = mycpu->gd_cpuid; 422 423 while ((tp = TAILQ_FIRST(&tcpcbackq[cpu])) != NULL) { 424 KKASSERT(tp->t_flags & TF_ONOUTPUTQ); 425 tp->t_flags &= ~TF_ONOUTPUTQ; 426 TAILQ_REMOVE(&tcpcbackq[cpu], tp, t_outputq); 427 tcp_output(tp); 428 } 429 } 430 431 /* 432 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 433 * tcp_template used to store this data in mbufs, but we now recopy it out 434 * of the tcpcb each time to conserve mbufs. 435 */ 436 void 437 tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso) 438 { 439 struct inpcb *inp = tp->t_inpcb; 440 struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; 441 442 #ifdef INET6 443 if (inp->inp_vflag & INP_IPV6) { 444 struct ip6_hdr *ip6; 445 446 ip6 = (struct ip6_hdr *)ip_ptr; 447 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 448 (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); 449 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 450 (IPV6_VERSION & IPV6_VERSION_MASK); 451 ip6->ip6_nxt = IPPROTO_TCP; 452 ip6->ip6_plen = sizeof(struct tcphdr); 453 ip6->ip6_src = inp->in6p_laddr; 454 ip6->ip6_dst = inp->in6p_faddr; 455 tcp_hdr->th_sum = 0; 456 } else 457 #endif 458 { 459 struct ip *ip = (struct ip *) ip_ptr; 460 u_int plen; 461 462 ip->ip_vhl = IP_VHL_BORING; 463 ip->ip_tos = 0; 464 ip->ip_len = 0; 465 ip->ip_id = 0; 466 ip->ip_off = 0; 467 ip->ip_ttl = 0; 468 ip->ip_sum = 0; 469 ip->ip_p = IPPROTO_TCP; 470 ip->ip_src = inp->inp_laddr; 471 ip->ip_dst = inp->inp_faddr; 472 473 if (tso) 474 plen = htons(IPPROTO_TCP); 475 else 476 plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP); 477 tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, 478 ip->ip_dst.s_addr, plen); 479 } 480 481 tcp_hdr->th_sport = inp->inp_lport; 482 tcp_hdr->th_dport = inp->inp_fport; 483 tcp_hdr->th_seq = 0; 484 tcp_hdr->th_ack = 0; 485 tcp_hdr->th_x2 = 0; 486 tcp_hdr->th_off = 5; 487 tcp_hdr->th_flags = 0; 488 tcp_hdr->th_win = 0; 489 tcp_hdr->th_urp = 0; 490 } 491 492 /* 493 * Create template to be used to send tcp packets on a connection. 494 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 495 * use for this function is in keepalives, which use tcp_respond. 496 */ 497 struct tcptemp * 498 tcp_maketemplate(struct tcpcb *tp) 499 { 500 struct tcptemp *tmp; 501 502 if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) 503 return (NULL); 504 tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE); 505 return (tmp); 506 } 507 508 void 509 tcp_freetemplate(struct tcptemp *tmp) 510 { 511 mpipe_free(&tcptemp_mpipe, tmp); 512 } 513 514 /* 515 * Send a single message to the TCP at address specified by 516 * the given TCP/IP header. If m == NULL, then we make a copy 517 * of the tcpiphdr at ti and send directly to the addressed host. 518 * This is used to force keep alive messages out using the TCP 519 * template for a connection. If flags are given then we send 520 * a message back to the TCP which originated the * segment ti, 521 * and discard the mbuf containing it and any other attached mbufs. 522 * 523 * In any case the ack and sequence number of the transmitted 524 * segment are as specified by the parameters. 525 * 526 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 527 */ 528 void 529 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 530 tcp_seq ack, tcp_seq seq, int flags) 531 { 532 int tlen; 533 int win = 0; 534 struct route *ro = NULL; 535 struct route sro; 536 struct ip *ip = ipgen; 537 struct tcphdr *nth; 538 int ipflags = 0; 539 struct route_in6 *ro6 = NULL; 540 struct route_in6 sro6; 541 struct ip6_hdr *ip6 = ipgen; 542 boolean_t use_tmpro = TRUE; 543 #ifdef INET6 544 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); 545 #else 546 const boolean_t isipv6 = FALSE; 547 #endif 548 549 if (tp != NULL) { 550 if (!(flags & TH_RST)) { 551 win = ssb_space(&tp->t_inpcb->inp_socket->so_rcv); 552 if (win < 0) 553 win = 0; 554 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 555 win = (long)TCP_MAXWIN << tp->rcv_scale; 556 } 557 /* 558 * Don't use the route cache of a listen socket, 559 * it is not MPSAFE; use temporary route cache. 560 */ 561 if (tp->t_state != TCPS_LISTEN) { 562 if (isipv6) 563 ro6 = &tp->t_inpcb->in6p_route; 564 else 565 ro = &tp->t_inpcb->inp_route; 566 use_tmpro = FALSE; 567 } 568 } 569 if (use_tmpro) { 570 if (isipv6) { 571 ro6 = &sro6; 572 bzero(ro6, sizeof *ro6); 573 } else { 574 ro = &sro; 575 bzero(ro, sizeof *ro); 576 } 577 } 578 if (m == NULL) { 579 m = m_gethdr(MB_DONTWAIT, MT_HEADER); 580 if (m == NULL) 581 return; 582 tlen = 0; 583 m->m_data += max_linkhdr; 584 if (isipv6) { 585 bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); 586 ip6 = mtod(m, struct ip6_hdr *); 587 nth = (struct tcphdr *)(ip6 + 1); 588 } else { 589 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); 590 ip = mtod(m, struct ip *); 591 nth = (struct tcphdr *)(ip + 1); 592 } 593 bcopy(th, nth, sizeof(struct tcphdr)); 594 flags = TH_ACK; 595 } else { 596 m_freem(m->m_next); 597 m->m_next = NULL; 598 m->m_data = (caddr_t)ipgen; 599 /* m_len is set later */ 600 tlen = 0; 601 #define xchg(a, b, type) { type t; t = a; a = b; b = t; } 602 if (isipv6) { 603 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 604 nth = (struct tcphdr *)(ip6 + 1); 605 } else { 606 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); 607 nth = (struct tcphdr *)(ip + 1); 608 } 609 if (th != nth) { 610 /* 611 * this is usually a case when an extension header 612 * exists between the IPv6 header and the 613 * TCP header. 614 */ 615 nth->th_sport = th->th_sport; 616 nth->th_dport = th->th_dport; 617 } 618 xchg(nth->th_dport, nth->th_sport, n_short); 619 #undef xchg 620 } 621 if (isipv6) { 622 ip6->ip6_flow = 0; 623 ip6->ip6_vfc = IPV6_VERSION; 624 ip6->ip6_nxt = IPPROTO_TCP; 625 ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); 626 tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 627 } else { 628 tlen += sizeof(struct tcpiphdr); 629 ip->ip_len = tlen; 630 ip->ip_ttl = ip_defttl; 631 } 632 m->m_len = tlen; 633 m->m_pkthdr.len = tlen; 634 m->m_pkthdr.rcvif = NULL; 635 nth->th_seq = htonl(seq); 636 nth->th_ack = htonl(ack); 637 nth->th_x2 = 0; 638 nth->th_off = sizeof(struct tcphdr) >> 2; 639 nth->th_flags = flags; 640 if (tp != NULL) 641 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 642 else 643 nth->th_win = htons((u_short)win); 644 nth->th_urp = 0; 645 if (isipv6) { 646 nth->th_sum = 0; 647 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 648 sizeof(struct ip6_hdr), 649 tlen - sizeof(struct ip6_hdr)); 650 ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, 651 (ro6 && ro6->ro_rt) ? 652 ro6->ro_rt->rt_ifp : NULL); 653 } else { 654 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 655 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 656 m->m_pkthdr.csum_flags = CSUM_TCP; 657 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 658 m->m_pkthdr.csum_thlen = sizeof(struct tcphdr); 659 } 660 #ifdef TCPDEBUG 661 if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 662 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 663 #endif 664 if (isipv6) { 665 ip6_output(m, NULL, ro6, ipflags, NULL, NULL, 666 tp ? tp->t_inpcb : NULL); 667 if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { 668 RTFREE(ro6->ro_rt); 669 ro6->ro_rt = NULL; 670 } 671 } else { 672 ipflags |= IP_DEBUGROUTE; 673 ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL); 674 if ((ro == &sro) && (ro->ro_rt != NULL)) { 675 RTFREE(ro->ro_rt); 676 ro->ro_rt = NULL; 677 } 678 } 679 } 680 681 /* 682 * Create a new TCP control block, making an 683 * empty reassembly queue and hooking it to the argument 684 * protocol control block. The `inp' parameter must have 685 * come from the zone allocator set up in tcp_init(). 686 */ 687 struct tcpcb * 688 tcp_newtcpcb(struct inpcb *inp) 689 { 690 struct inp_tp *it; 691 struct tcpcb *tp; 692 #ifdef INET6 693 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 694 #else 695 const boolean_t isipv6 = FALSE; 696 #endif 697 698 it = (struct inp_tp *)inp; 699 tp = &it->tcb; 700 bzero(tp, sizeof(struct tcpcb)); 701 TAILQ_INIT(&tp->t_segq); 702 tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; 703 tp->t_rxtthresh = tcprexmtthresh; 704 705 /* Set up our timeouts. */ 706 tp->tt_rexmt = &it->inp_tp_rexmt; 707 tp->tt_persist = &it->inp_tp_persist; 708 tp->tt_keep = &it->inp_tp_keep; 709 tp->tt_2msl = &it->inp_tp_2msl; 710 tp->tt_delack = &it->inp_tp_delack; 711 tcp_inittimers(tp); 712 713 /* 714 * Zero out timer message. We don't create it here, 715 * since the current CPU may not be the owner of this 716 * inpcb. 717 */ 718 tp->tt_msg = &it->inp_tp_timermsg; 719 bzero(tp->tt_msg, sizeof(*tp->tt_msg)); 720 721 tp->t_keepinit = tcp_keepinit; 722 tp->t_keepidle = tcp_keepidle; 723 tp->t_keepintvl = tcp_keepintvl; 724 tp->t_keepcnt = tcp_keepcnt; 725 tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt; 726 727 if (tcp_do_ncr) 728 tp->t_flags |= TF_NCR; 729 if (tcp_do_rfc1323) 730 tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP); 731 732 tp->t_inpcb = inp; /* XXX */ 733 tp->t_state = TCPS_CLOSED; 734 /* 735 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 736 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 737 * reasonable initial retransmit time. 738 */ 739 tp->t_srtt = TCPTV_SRTTBASE; 740 tp->t_rttvar = 741 ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 742 tp->t_rttmin = tcp_rexmit_min; 743 tp->t_rxtcur = TCPTV_RTOBASE; 744 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 745 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 746 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 747 tp->snd_last = ticks; 748 tp->t_rcvtime = ticks; 749 /* 750 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 751 * because the socket may be bound to an IPv6 wildcard address, 752 * which may match an IPv4-mapped IPv6 address. 753 */ 754 inp->inp_ip_ttl = ip_defttl; 755 inp->inp_ppcb = tp; 756 tcp_sack_tcpcb_init(tp); 757 return (tp); /* XXX */ 758 } 759 760 /* 761 * Drop a TCP connection, reporting the specified error. 762 * If connection is synchronized, then send a RST to peer. 763 */ 764 struct tcpcb * 765 tcp_drop(struct tcpcb *tp, int error) 766 { 767 struct socket *so = tp->t_inpcb->inp_socket; 768 769 if (TCPS_HAVERCVDSYN(tp->t_state)) { 770 tp->t_state = TCPS_CLOSED; 771 tcp_output(tp); 772 tcpstat.tcps_drops++; 773 } else 774 tcpstat.tcps_conndrops++; 775 if (error == ETIMEDOUT && tp->t_softerror) 776 error = tp->t_softerror; 777 so->so_error = error; 778 return (tcp_close(tp)); 779 } 780 781 struct netmsg_listen_detach { 782 struct netmsg_base base; 783 struct tcpcb *nm_tp; 784 }; 785 786 static void 787 tcp_listen_detach_handler(netmsg_t msg) 788 { 789 struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; 790 struct tcpcb *tp = nmsg->nm_tp; 791 int cpu = mycpuid, nextcpu; 792 793 if (tp->t_flags & TF_LISTEN) 794 syncache_destroy(tp); 795 796 in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); 797 798 nextcpu = cpu + 1; 799 if (nextcpu < ncpus2) 800 lwkt_forwardmsg(netisr_portfn(nextcpu), &nmsg->base.lmsg); 801 else 802 lwkt_replymsg(&nmsg->base.lmsg, 0); 803 } 804 805 /* 806 * Close a TCP control block: 807 * discard all space held by the tcp 808 * discard internet protocol block 809 * wake up any sleepers 810 */ 811 struct tcpcb * 812 tcp_close(struct tcpcb *tp) 813 { 814 struct tseg_qent *q; 815 struct inpcb *inp = tp->t_inpcb; 816 struct socket *so = inp->inp_socket; 817 struct rtentry *rt; 818 boolean_t dosavessthresh; 819 #ifdef INET6 820 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) != 0); 821 boolean_t isafinet6 = (INP_CHECK_SOCKAF(so, AF_INET6) != 0); 822 #else 823 const boolean_t isipv6 = FALSE; 824 #endif 825 826 /* 827 * INP_WILDCARD_MP indicates that listen(2) has been called on 828 * this socket. This implies: 829 * - A wildcard inp's hash is replicated for each protocol thread. 830 * - Syncache for this inp grows independently in each protocol 831 * thread. 832 * - There is more than one cpu 833 * 834 * We have to chain a message to the rest of the protocol threads 835 * to cleanup the wildcard hash and the syncache. The cleanup 836 * in the current protocol thread is defered till the end of this 837 * function. 838 * 839 * NOTE: 840 * After cleanup the inp's hash and syncache entries, this inp will 841 * no longer be available to the rest of the protocol threads, so we 842 * are safe to whack the inp in the following code. 843 */ 844 if (inp->inp_flags & INP_WILDCARD_MP) { 845 struct netmsg_listen_detach nmsg; 846 847 KKASSERT(so->so_port == netisr_portfn(0)); 848 KKASSERT(&curthread->td_msgport == netisr_portfn(0)); 849 KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); 850 851 netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, 852 MSGF_PRIORITY, tcp_listen_detach_handler); 853 nmsg.nm_tp = tp; 854 lwkt_domsg(netisr_portfn(1), &nmsg.base.lmsg, 0); 855 856 inp->inp_flags &= ~INP_WILDCARD_MP; 857 } 858 859 KKASSERT(tp->t_state != TCPS_TERMINATING); 860 tp->t_state = TCPS_TERMINATING; 861 862 /* 863 * Make sure that all of our timers are stopped before we 864 * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), 865 * timers are never used. If timer message is never created 866 * (tp->tt_msg->tt_tcb == NULL), timers are never used too. 867 */ 868 if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { 869 tcp_callout_stop(tp, tp->tt_rexmt); 870 tcp_callout_stop(tp, tp->tt_persist); 871 tcp_callout_stop(tp, tp->tt_keep); 872 tcp_callout_stop(tp, tp->tt_2msl); 873 tcp_callout_stop(tp, tp->tt_delack); 874 } 875 876 if (tp->t_flags & TF_ONOUTPUTQ) { 877 KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); 878 TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu], tp, t_outputq); 879 tp->t_flags &= ~TF_ONOUTPUTQ; 880 } 881 882 /* 883 * If we got enough samples through the srtt filter, 884 * save the rtt and rttvar in the routing entry. 885 * 'Enough' is arbitrarily defined as the 16 samples. 886 * 16 samples is enough for the srtt filter to converge 887 * to within 5% of the correct value; fewer samples and 888 * we could save a very bogus rtt. 889 * 890 * Don't update the default route's characteristics and don't 891 * update anything that the user "locked". 892 */ 893 if (tp->t_rttupdated >= 16) { 894 u_long i = 0; 895 896 if (isipv6) { 897 struct sockaddr_in6 *sin6; 898 899 if ((rt = inp->in6p_route.ro_rt) == NULL) 900 goto no_valid_rt; 901 sin6 = (struct sockaddr_in6 *)rt_key(rt); 902 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) 903 goto no_valid_rt; 904 } else 905 if ((rt = inp->inp_route.ro_rt) == NULL || 906 ((struct sockaddr_in *)rt_key(rt))-> 907 sin_addr.s_addr == INADDR_ANY) 908 goto no_valid_rt; 909 910 if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { 911 i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); 912 if (rt->rt_rmx.rmx_rtt && i) 913 /* 914 * filter this update to half the old & half 915 * the new values, converting scale. 916 * See route.h and tcp_var.h for a 917 * description of the scaling constants. 918 */ 919 rt->rt_rmx.rmx_rtt = 920 (rt->rt_rmx.rmx_rtt + i) / 2; 921 else 922 rt->rt_rmx.rmx_rtt = i; 923 tcpstat.tcps_cachedrtt++; 924 } 925 if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { 926 i = tp->t_rttvar * 927 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); 928 if (rt->rt_rmx.rmx_rttvar && i) 929 rt->rt_rmx.rmx_rttvar = 930 (rt->rt_rmx.rmx_rttvar + i) / 2; 931 else 932 rt->rt_rmx.rmx_rttvar = i; 933 tcpstat.tcps_cachedrttvar++; 934 } 935 /* 936 * The old comment here said: 937 * update the pipelimit (ssthresh) if it has been updated 938 * already or if a pipesize was specified & the threshhold 939 * got below half the pipesize. I.e., wait for bad news 940 * before we start updating, then update on both good 941 * and bad news. 942 * 943 * But we want to save the ssthresh even if no pipesize is 944 * specified explicitly in the route, because such 945 * connections still have an implicit pipesize specified 946 * by the global tcp_sendspace. In the absence of a reliable 947 * way to calculate the pipesize, it will have to do. 948 */ 949 i = tp->snd_ssthresh; 950 if (rt->rt_rmx.rmx_sendpipe != 0) 951 dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); 952 else 953 dosavessthresh = (i < so->so_snd.ssb_hiwat/2); 954 if (dosavessthresh || 955 (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && 956 (rt->rt_rmx.rmx_ssthresh != 0))) { 957 /* 958 * convert the limit from user data bytes to 959 * packets then to packet data bytes. 960 */ 961 i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 962 if (i < 2) 963 i = 2; 964 i *= tp->t_maxseg + 965 (isipv6 ? 966 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 967 sizeof(struct tcpiphdr)); 968 if (rt->rt_rmx.rmx_ssthresh) 969 rt->rt_rmx.rmx_ssthresh = 970 (rt->rt_rmx.rmx_ssthresh + i) / 2; 971 else 972 rt->rt_rmx.rmx_ssthresh = i; 973 tcpstat.tcps_cachedssthresh++; 974 } 975 } 976 977 no_valid_rt: 978 /* free the reassembly queue, if any */ 979 while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) { 980 TAILQ_REMOVE(&tp->t_segq, q, tqe_q); 981 m_freem(q->tqe_m); 982 kfree(q, M_TSEGQ); 983 atomic_add_int(&tcp_reass_qsize, -1); 984 } 985 /* throw away SACK blocks in scoreboard*/ 986 if (TCP_DO_SACK(tp)) 987 tcp_sack_destroy(&tp->scb); 988 989 inp->inp_ppcb = NULL; 990 soisdisconnected(so); 991 /* note: pcb detached later on */ 992 993 tcp_destroy_timermsg(tp); 994 995 if (tp->t_flags & TF_LISTEN) 996 syncache_destroy(tp); 997 998 so_async_rcvd_drop(so); 999 1000 /* 1001 * NOTE: 1002 * pcbdetach removes any wildcard hash entry on the current CPU. 1003 */ 1004 #ifdef INET6 1005 if (isafinet6) 1006 in6_pcbdetach(inp); 1007 else 1008 #endif 1009 in_pcbdetach(inp); 1010 1011 tcpstat.tcps_closed++; 1012 return (NULL); 1013 } 1014 1015 static __inline void 1016 tcp_drain_oncpu(struct inpcbhead *head) 1017 { 1018 struct inpcb *marker; 1019 struct inpcb *inpb; 1020 struct tcpcb *tcpb; 1021 struct tseg_qent *te; 1022 1023 /* 1024 * Allows us to block while running the list 1025 */ 1026 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1027 marker->inp_flags |= INP_PLACEMARKER; 1028 LIST_INSERT_HEAD(head, marker, inp_list); 1029 1030 while ((inpb = LIST_NEXT(marker, inp_list)) != NULL) { 1031 if ((inpb->inp_flags & INP_PLACEMARKER) == 0 && 1032 (tcpb = intotcpcb(inpb)) != NULL && 1033 (te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) { 1034 TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q); 1035 if (te->tqe_th->th_flags & TH_FIN) 1036 tcpb->t_flags &= ~TF_QUEDFIN; 1037 m_freem(te->tqe_m); 1038 kfree(te, M_TSEGQ); 1039 atomic_add_int(&tcp_reass_qsize, -1); 1040 /* retry */ 1041 } else { 1042 LIST_REMOVE(marker, inp_list); 1043 LIST_INSERT_AFTER(inpb, marker, inp_list); 1044 } 1045 } 1046 LIST_REMOVE(marker, inp_list); 1047 kfree(marker, M_TEMP); 1048 } 1049 1050 struct netmsg_tcp_drain { 1051 struct netmsg_base base; 1052 struct inpcbhead *nm_head; 1053 }; 1054 1055 static void 1056 tcp_drain_handler(netmsg_t msg) 1057 { 1058 struct netmsg_tcp_drain *nm = (void *)msg; 1059 1060 tcp_drain_oncpu(nm->nm_head); 1061 lwkt_replymsg(&nm->base.lmsg, 0); 1062 } 1063 1064 void 1065 tcp_drain(void) 1066 { 1067 int cpu; 1068 1069 if (!do_tcpdrain) 1070 return; 1071 1072 /* 1073 * Walk the tcpbs, if existing, and flush the reassembly queue, 1074 * if there is one... 1075 * XXX: The "Net/3" implementation doesn't imply that the TCP 1076 * reassembly queue should be flushed, but in a situation 1077 * where we're really low on mbufs, this is potentially 1078 * useful. 1079 */ 1080 for (cpu = 0; cpu < ncpus2; cpu++) { 1081 struct netmsg_tcp_drain *nm; 1082 1083 if (cpu == mycpu->gd_cpuid) { 1084 tcp_drain_oncpu(&tcbinfo[cpu].pcblisthead); 1085 } else { 1086 nm = kmalloc(sizeof(struct netmsg_tcp_drain), 1087 M_LWKTMSG, M_NOWAIT); 1088 if (nm == NULL) 1089 continue; 1090 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1091 0, tcp_drain_handler); 1092 nm->nm_head = &tcbinfo[cpu].pcblisthead; 1093 lwkt_sendmsg(netisr_portfn(cpu), &nm->base.lmsg); 1094 } 1095 } 1096 } 1097 1098 /* 1099 * Notify a tcp user of an asynchronous error; 1100 * store error as soft error, but wake up user 1101 * (for now, won't do anything until can select for soft error). 1102 * 1103 * Do not wake up user since there currently is no mechanism for 1104 * reporting soft errors (yet - a kqueue filter may be added). 1105 */ 1106 static void 1107 tcp_notify(struct inpcb *inp, int error) 1108 { 1109 struct tcpcb *tp = intotcpcb(inp); 1110 1111 /* 1112 * Ignore some errors if we are hooked up. 1113 * If connection hasn't completed, has retransmitted several times, 1114 * and receives a second error, give up now. This is better 1115 * than waiting a long time to establish a connection that 1116 * can never complete. 1117 */ 1118 if (tp->t_state == TCPS_ESTABLISHED && 1119 (error == EHOSTUNREACH || error == ENETUNREACH || 1120 error == EHOSTDOWN)) { 1121 return; 1122 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1123 tp->t_softerror) 1124 tcp_drop(tp, error); 1125 else 1126 tp->t_softerror = error; 1127 #if 0 1128 wakeup(&so->so_timeo); 1129 sorwakeup(so); 1130 sowwakeup(so); 1131 #endif 1132 } 1133 1134 static int 1135 tcp_pcblist(SYSCTL_HANDLER_ARGS) 1136 { 1137 int error, i, n; 1138 struct inpcb *marker; 1139 struct inpcb *inp; 1140 globaldata_t gd; 1141 int origcpu, ccpu; 1142 1143 error = 0; 1144 n = 0; 1145 1146 /* 1147 * The process of preparing the TCB list is too time-consuming and 1148 * resource-intensive to repeat twice on every request. 1149 */ 1150 if (req->oldptr == NULL) { 1151 for (ccpu = 0; ccpu < ncpus; ++ccpu) { 1152 gd = globaldata_find(ccpu); 1153 n += tcbinfo[gd->gd_cpuid].ipi_count; 1154 } 1155 req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); 1156 return (0); 1157 } 1158 1159 if (req->newptr != NULL) 1160 return (EPERM); 1161 1162 marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); 1163 marker->inp_flags |= INP_PLACEMARKER; 1164 1165 /* 1166 * OK, now we're committed to doing something. Run the inpcb list 1167 * for each cpu in the system and construct the output. Use a 1168 * list placemarker to deal with list changes occuring during 1169 * copyout blockages (but otherwise depend on being on the correct 1170 * cpu to avoid races). 1171 */ 1172 origcpu = mycpu->gd_cpuid; 1173 for (ccpu = 1; ccpu <= ncpus && error == 0; ++ccpu) { 1174 globaldata_t rgd; 1175 caddr_t inp_ppcb; 1176 struct xtcpcb xt; 1177 int cpu_id; 1178 1179 cpu_id = (origcpu + ccpu) % ncpus; 1180 if ((smp_active_mask & CPUMASK(cpu_id)) == 0) 1181 continue; 1182 rgd = globaldata_find(cpu_id); 1183 lwkt_setcpu_self(rgd); 1184 1185 n = tcbinfo[cpu_id].ipi_count; 1186 1187 LIST_INSERT_HEAD(&tcbinfo[cpu_id].pcblisthead, marker, inp_list); 1188 i = 0; 1189 while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { 1190 /* 1191 * process a snapshot of pcbs, ignoring placemarkers 1192 * and using our own to allow SYSCTL_OUT to block. 1193 */ 1194 LIST_REMOVE(marker, inp_list); 1195 LIST_INSERT_AFTER(inp, marker, inp_list); 1196 1197 if (inp->inp_flags & INP_PLACEMARKER) 1198 continue; 1199 if (prison_xinpcb(req->td, inp)) 1200 continue; 1201 1202 xt.xt_len = sizeof xt; 1203 bcopy(inp, &xt.xt_inp, sizeof *inp); 1204 inp_ppcb = inp->inp_ppcb; 1205 if (inp_ppcb != NULL) 1206 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1207 else 1208 bzero(&xt.xt_tp, sizeof xt.xt_tp); 1209 if (inp->inp_socket) 1210 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1211 if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) 1212 break; 1213 ++i; 1214 } 1215 LIST_REMOVE(marker, inp_list); 1216 if (error == 0 && i < n) { 1217 bzero(&xt, sizeof xt); 1218 xt.xt_len = sizeof xt; 1219 while (i < n) { 1220 error = SYSCTL_OUT(req, &xt, sizeof xt); 1221 if (error) 1222 break; 1223 ++i; 1224 } 1225 } 1226 } 1227 1228 /* 1229 * Make sure we are on the same cpu we were on originally, since 1230 * higher level callers expect this. Also don't pollute caches with 1231 * migrated userland data by (eventually) returning to userland 1232 * on a different cpu. 1233 */ 1234 lwkt_setcpu_self(globaldata_find(origcpu)); 1235 kfree(marker, M_TEMP); 1236 return (error); 1237 } 1238 1239 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1240 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1241 1242 static int 1243 tcp_getcred(SYSCTL_HANDLER_ARGS) 1244 { 1245 struct sockaddr_in addrs[2]; 1246 struct inpcb *inp; 1247 int cpu; 1248 int error; 1249 1250 error = priv_check(req->td, PRIV_ROOT); 1251 if (error != 0) 1252 return (error); 1253 error = SYSCTL_IN(req, addrs, sizeof addrs); 1254 if (error != 0) 1255 return (error); 1256 crit_enter(); 1257 cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, 1258 addrs[0].sin_addr.s_addr, addrs[0].sin_port); 1259 inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, 1260 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1261 if (inp == NULL || inp->inp_socket == NULL) { 1262 error = ENOENT; 1263 goto out; 1264 } 1265 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1266 out: 1267 crit_exit(); 1268 return (error); 1269 } 1270 1271 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1272 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); 1273 1274 #ifdef INET6 1275 static int 1276 tcp6_getcred(SYSCTL_HANDLER_ARGS) 1277 { 1278 struct sockaddr_in6 addrs[2]; 1279 struct inpcb *inp; 1280 int error; 1281 boolean_t mapped = FALSE; 1282 1283 error = priv_check(req->td, PRIV_ROOT); 1284 if (error != 0) 1285 return (error); 1286 error = SYSCTL_IN(req, addrs, sizeof addrs); 1287 if (error != 0) 1288 return (error); 1289 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1290 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1291 mapped = TRUE; 1292 else 1293 return (EINVAL); 1294 } 1295 crit_enter(); 1296 if (mapped) { 1297 inp = in_pcblookup_hash(&tcbinfo[0], 1298 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1299 addrs[1].sin6_port, 1300 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1301 addrs[0].sin6_port, 1302 0, NULL); 1303 } else { 1304 inp = in6_pcblookup_hash(&tcbinfo[0], 1305 &addrs[1].sin6_addr, addrs[1].sin6_port, 1306 &addrs[0].sin6_addr, addrs[0].sin6_port, 1307 0, NULL); 1308 } 1309 if (inp == NULL || inp->inp_socket == NULL) { 1310 error = ENOENT; 1311 goto out; 1312 } 1313 error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); 1314 out: 1315 crit_exit(); 1316 return (error); 1317 } 1318 1319 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 1320 0, 0, 1321 tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); 1322 #endif 1323 1324 struct netmsg_tcp_notify { 1325 struct netmsg_base base; 1326 void (*nm_notify)(struct inpcb *, int); 1327 struct in_addr nm_faddr; 1328 int nm_arg; 1329 }; 1330 1331 static void 1332 tcp_notifyall_oncpu(netmsg_t msg) 1333 { 1334 struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; 1335 int nextcpu; 1336 1337 in_pcbnotifyall(&tcbinfo[mycpuid].pcblisthead, nm->nm_faddr, 1338 nm->nm_arg, nm->nm_notify); 1339 1340 nextcpu = mycpuid + 1; 1341 if (nextcpu < ncpus2) 1342 lwkt_forwardmsg(netisr_portfn(nextcpu), &nm->base.lmsg); 1343 else 1344 lwkt_replymsg(&nm->base.lmsg, 0); 1345 } 1346 1347 void 1348 tcp_ctlinput(netmsg_t msg) 1349 { 1350 int cmd = msg->ctlinput.nm_cmd; 1351 struct sockaddr *sa = msg->ctlinput.nm_arg; 1352 struct ip *ip = msg->ctlinput.nm_extra; 1353 struct tcphdr *th; 1354 struct in_addr faddr; 1355 struct inpcb *inp; 1356 struct tcpcb *tp; 1357 void (*notify)(struct inpcb *, int) = tcp_notify; 1358 tcp_seq icmpseq; 1359 int arg, cpu; 1360 1361 if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { 1362 goto done; 1363 } 1364 1365 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1366 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1367 goto done; 1368 1369 arg = inetctlerrmap[cmd]; 1370 if (cmd == PRC_QUENCH) { 1371 notify = tcp_quench; 1372 } else if (icmp_may_rst && 1373 (cmd == PRC_UNREACH_ADMIN_PROHIB || 1374 cmd == PRC_UNREACH_PORT || 1375 cmd == PRC_TIMXCEED_INTRANS) && 1376 ip != NULL) { 1377 notify = tcp_drop_syn_sent; 1378 } else if (cmd == PRC_MSGSIZE) { 1379 struct icmp *icmp = (struct icmp *) 1380 ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); 1381 1382 arg = ntohs(icmp->icmp_nextmtu); 1383 notify = tcp_mtudisc; 1384 } else if (PRC_IS_REDIRECT(cmd)) { 1385 ip = NULL; 1386 notify = in_rtchange; 1387 } else if (cmd == PRC_HOSTDEAD) { 1388 ip = NULL; 1389 } 1390 1391 if (ip != NULL) { 1392 crit_enter(); 1393 th = (struct tcphdr *)((caddr_t)ip + 1394 (IP_VHL_HL(ip->ip_vhl) << 2)); 1395 cpu = tcp_addrcpu(faddr.s_addr, th->th_dport, 1396 ip->ip_src.s_addr, th->th_sport); 1397 inp = in_pcblookup_hash(&tcbinfo[cpu], faddr, th->th_dport, 1398 ip->ip_src, th->th_sport, 0, NULL); 1399 if ((inp != NULL) && (inp->inp_socket != NULL)) { 1400 icmpseq = htonl(th->th_seq); 1401 tp = intotcpcb(inp); 1402 if (SEQ_GEQ(icmpseq, tp->snd_una) && 1403 SEQ_LT(icmpseq, tp->snd_max)) 1404 (*notify)(inp, arg); 1405 } else { 1406 struct in_conninfo inc; 1407 1408 inc.inc_fport = th->th_dport; 1409 inc.inc_lport = th->th_sport; 1410 inc.inc_faddr = faddr; 1411 inc.inc_laddr = ip->ip_src; 1412 #ifdef INET6 1413 inc.inc_isipv6 = 0; 1414 #endif 1415 syncache_unreach(&inc, th); 1416 } 1417 crit_exit(); 1418 } else { 1419 struct netmsg_tcp_notify *nm; 1420 1421 KKASSERT(&curthread->td_msgport == netisr_portfn(0)); 1422 nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); 1423 netmsg_init(&nm->base, NULL, &netisr_afree_rport, 1424 0, tcp_notifyall_oncpu); 1425 nm->nm_faddr = faddr; 1426 nm->nm_arg = arg; 1427 nm->nm_notify = notify; 1428 1429 lwkt_sendmsg(netisr_portfn(0), &nm->base.lmsg); 1430 } 1431 done: 1432 lwkt_replymsg(&msg->lmsg, 0); 1433 } 1434 1435 #ifdef INET6 1436 1437 void 1438 tcp6_ctlinput(netmsg_t msg) 1439 { 1440 int cmd = msg->ctlinput.nm_cmd; 1441 struct sockaddr *sa = msg->ctlinput.nm_arg; 1442 void *d = msg->ctlinput.nm_extra; 1443 struct tcphdr th; 1444 void (*notify) (struct inpcb *, int) = tcp_notify; 1445 struct ip6_hdr *ip6; 1446 struct mbuf *m; 1447 struct ip6ctlparam *ip6cp = NULL; 1448 const struct sockaddr_in6 *sa6_src = NULL; 1449 int off; 1450 struct tcp_portonly { 1451 u_int16_t th_sport; 1452 u_int16_t th_dport; 1453 } *thp; 1454 int arg; 1455 1456 if (sa->sa_family != AF_INET6 || 1457 sa->sa_len != sizeof(struct sockaddr_in6)) { 1458 goto out; 1459 } 1460 1461 arg = 0; 1462 if (cmd == PRC_QUENCH) 1463 notify = tcp_quench; 1464 else if (cmd == PRC_MSGSIZE) { 1465 struct ip6ctlparam *ip6cp = d; 1466 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; 1467 1468 arg = ntohl(icmp6->icmp6_mtu); 1469 notify = tcp_mtudisc; 1470 } else if (!PRC_IS_REDIRECT(cmd) && 1471 ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { 1472 goto out; 1473 } 1474 1475 /* if the parameter is from icmp6, decode it. */ 1476 if (d != NULL) { 1477 ip6cp = (struct ip6ctlparam *)d; 1478 m = ip6cp->ip6c_m; 1479 ip6 = ip6cp->ip6c_ip6; 1480 off = ip6cp->ip6c_off; 1481 sa6_src = ip6cp->ip6c_src; 1482 } else { 1483 m = NULL; 1484 ip6 = NULL; 1485 off = 0; /* fool gcc */ 1486 sa6_src = &sa6_any; 1487 } 1488 1489 if (ip6 != NULL) { 1490 struct in_conninfo inc; 1491 /* 1492 * XXX: We assume that when IPV6 is non NULL, 1493 * M and OFF are valid. 1494 */ 1495 1496 /* check if we can safely examine src and dst ports */ 1497 if (m->m_pkthdr.len < off + sizeof *thp) 1498 goto out; 1499 1500 bzero(&th, sizeof th); 1501 m_copydata(m, off, sizeof *thp, (caddr_t)&th); 1502 1503 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, th.th_dport, 1504 (struct sockaddr *)ip6cp->ip6c_src, 1505 th.th_sport, cmd, arg, notify); 1506 1507 inc.inc_fport = th.th_dport; 1508 inc.inc_lport = th.th_sport; 1509 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1510 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1511 inc.inc_isipv6 = 1; 1512 syncache_unreach(&inc, &th); 1513 } else { 1514 in6_pcbnotify(&tcbinfo[0].pcblisthead, sa, 0, 1515 (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); 1516 } 1517 out: 1518 lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); 1519 } 1520 1521 #endif 1522 1523 /* 1524 * Following is where TCP initial sequence number generation occurs. 1525 * 1526 * There are two places where we must use initial sequence numbers: 1527 * 1. In SYN-ACK packets. 1528 * 2. In SYN packets. 1529 * 1530 * All ISNs for SYN-ACK packets are generated by the syncache. See 1531 * tcp_syncache.c for details. 1532 * 1533 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1534 * depends on this property. In addition, these ISNs should be 1535 * unguessable so as to prevent connection hijacking. To satisfy 1536 * the requirements of this situation, the algorithm outlined in 1537 * RFC 1948 is used to generate sequence numbers. 1538 * 1539 * Implementation details: 1540 * 1541 * Time is based off the system timer, and is corrected so that it 1542 * increases by one megabyte per second. This allows for proper 1543 * recycling on high speed LANs while still leaving over an hour 1544 * before rollover. 1545 * 1546 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1547 * between seeding of isn_secret. This is normally set to zero, 1548 * as reseeding should not be necessary. 1549 * 1550 */ 1551 1552 #define ISN_BYTES_PER_SECOND 1048576 1553 1554 u_char isn_secret[32]; 1555 int isn_last_reseed; 1556 MD5_CTX isn_ctx; 1557 1558 tcp_seq 1559 tcp_new_isn(struct tcpcb *tp) 1560 { 1561 u_int32_t md5_buffer[4]; 1562 tcp_seq new_isn; 1563 1564 /* Seed if this is the first use, reseed if requested. */ 1565 if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) && 1566 (((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz) 1567 < (u_int)ticks))) { 1568 read_random_unlimited(&isn_secret, sizeof isn_secret); 1569 isn_last_reseed = ticks; 1570 } 1571 1572 /* Compute the md5 hash and return the ISN. */ 1573 MD5Init(&isn_ctx); 1574 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_fport, sizeof(u_short)); 1575 MD5Update(&isn_ctx, (u_char *)&tp->t_inpcb->inp_lport, sizeof(u_short)); 1576 #ifdef INET6 1577 if (tp->t_inpcb->inp_vflag & INP_IPV6) { 1578 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1579 sizeof(struct in6_addr)); 1580 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1581 sizeof(struct in6_addr)); 1582 } else 1583 #endif 1584 { 1585 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1586 sizeof(struct in_addr)); 1587 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1588 sizeof(struct in_addr)); 1589 } 1590 MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret)); 1591 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1592 new_isn = (tcp_seq) md5_buffer[0]; 1593 new_isn += ticks * (ISN_BYTES_PER_SECOND / hz); 1594 return (new_isn); 1595 } 1596 1597 /* 1598 * When a source quench is received, close congestion window 1599 * to one segment. We will gradually open it again as we proceed. 1600 */ 1601 void 1602 tcp_quench(struct inpcb *inp, int error) 1603 { 1604 struct tcpcb *tp = intotcpcb(inp); 1605 1606 if (tp != NULL) { 1607 tp->snd_cwnd = tp->t_maxseg; 1608 tp->snd_wacked = 0; 1609 } 1610 } 1611 1612 /* 1613 * When a specific ICMP unreachable message is received and the 1614 * connection state is SYN-SENT, drop the connection. This behavior 1615 * is controlled by the icmp_may_rst sysctl. 1616 */ 1617 void 1618 tcp_drop_syn_sent(struct inpcb *inp, int error) 1619 { 1620 struct tcpcb *tp = intotcpcb(inp); 1621 1622 if ((tp != NULL) && (tp->t_state == TCPS_SYN_SENT)) 1623 tcp_drop(tp, error); 1624 } 1625 1626 /* 1627 * When a `need fragmentation' ICMP is received, update our idea of the MSS 1628 * based on the new value in the route. Also nudge TCP to send something, 1629 * since we know the packet we just sent was dropped. 1630 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1631 */ 1632 void 1633 tcp_mtudisc(struct inpcb *inp, int mtu) 1634 { 1635 struct tcpcb *tp = intotcpcb(inp); 1636 struct rtentry *rt; 1637 struct socket *so = inp->inp_socket; 1638 int maxopd, mss; 1639 #ifdef INET6 1640 boolean_t isipv6 = ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0); 1641 #else 1642 const boolean_t isipv6 = FALSE; 1643 #endif 1644 1645 if (tp == NULL) 1646 return; 1647 1648 /* 1649 * If no MTU is provided in the ICMP message, use the 1650 * next lower likely value, as specified in RFC 1191. 1651 */ 1652 if (mtu == 0) { 1653 int oldmtu; 1654 1655 oldmtu = tp->t_maxopd + 1656 (isipv6 ? 1657 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1658 sizeof(struct tcpiphdr)); 1659 mtu = ip_next_mtu(oldmtu, 0); 1660 } 1661 1662 if (isipv6) 1663 rt = tcp_rtlookup6(&inp->inp_inc); 1664 else 1665 rt = tcp_rtlookup(&inp->inp_inc); 1666 if (rt != NULL) { 1667 if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) 1668 mtu = rt->rt_rmx.rmx_mtu; 1669 1670 maxopd = mtu - 1671 (isipv6 ? 1672 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1673 sizeof(struct tcpiphdr)); 1674 1675 /* 1676 * XXX - The following conditional probably violates the TCP 1677 * spec. The problem is that, since we don't know the 1678 * other end's MSS, we are supposed to use a conservative 1679 * default. But, if we do that, then MTU discovery will 1680 * never actually take place, because the conservative 1681 * default is much less than the MTUs typically seen 1682 * on the Internet today. For the moment, we'll sweep 1683 * this under the carpet. 1684 * 1685 * The conservative default might not actually be a problem 1686 * if the only case this occurs is when sending an initial 1687 * SYN with options and data to a host we've never talked 1688 * to before. Then, they will reply with an MSS value which 1689 * will get recorded and the new parameters should get 1690 * recomputed. For Further Study. 1691 */ 1692 if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) 1693 maxopd = rt->rt_rmx.rmx_mssopt; 1694 } else 1695 maxopd = mtu - 1696 (isipv6 ? 1697 sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : 1698 sizeof(struct tcpiphdr)); 1699 1700 if (tp->t_maxopd <= maxopd) 1701 return; 1702 tp->t_maxopd = maxopd; 1703 1704 mss = maxopd; 1705 if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == 1706 (TF_REQ_TSTMP | TF_RCVD_TSTMP)) 1707 mss -= TCPOLEN_TSTAMP_APPA; 1708 1709 /* round down to multiple of MCLBYTES */ 1710 #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ 1711 if (mss > MCLBYTES) 1712 mss &= ~(MCLBYTES - 1); 1713 #else 1714 if (mss > MCLBYTES) 1715 mss = (mss / MCLBYTES) * MCLBYTES; 1716 #endif 1717 1718 if (so->so_snd.ssb_hiwat < mss) 1719 mss = so->so_snd.ssb_hiwat; 1720 1721 tp->t_maxseg = mss; 1722 tp->t_rtttime = 0; 1723 tp->snd_nxt = tp->snd_una; 1724 tcp_output(tp); 1725 tcpstat.tcps_mturesent++; 1726 } 1727 1728 /* 1729 * Look-up the routing entry to the peer of this inpcb. If no route 1730 * is found and it cannot be allocated the return NULL. This routine 1731 * is called by TCP routines that access the rmx structure and by tcp_mss 1732 * to get the interface MTU. 1733 */ 1734 struct rtentry * 1735 tcp_rtlookup(struct in_conninfo *inc) 1736 { 1737 struct route *ro = &inc->inc_route; 1738 1739 if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { 1740 /* No route yet, so try to acquire one */ 1741 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1742 /* 1743 * unused portions of the structure MUST be zero'd 1744 * out because rtalloc() treats it as opaque data 1745 */ 1746 bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); 1747 ro->ro_dst.sa_family = AF_INET; 1748 ro->ro_dst.sa_len = sizeof(struct sockaddr_in); 1749 ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 1750 inc->inc_faddr; 1751 rtalloc(ro); 1752 } 1753 } 1754 return (ro->ro_rt); 1755 } 1756 1757 #ifdef INET6 1758 struct rtentry * 1759 tcp_rtlookup6(struct in_conninfo *inc) 1760 { 1761 struct route_in6 *ro6 = &inc->inc6_route; 1762 1763 if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { 1764 /* No route yet, so try to acquire one */ 1765 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1766 /* 1767 * unused portions of the structure MUST be zero'd 1768 * out because rtalloc() treats it as opaque data 1769 */ 1770 bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); 1771 ro6->ro_dst.sin6_family = AF_INET6; 1772 ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1773 ro6->ro_dst.sin6_addr = inc->inc6_faddr; 1774 rtalloc((struct route *)ro6); 1775 } 1776 } 1777 return (ro6->ro_rt); 1778 } 1779 #endif 1780 1781 #ifdef IPSEC 1782 /* compute ESP/AH header size for TCP, including outer IP header. */ 1783 size_t 1784 ipsec_hdrsiz_tcp(struct tcpcb *tp) 1785 { 1786 struct inpcb *inp; 1787 struct mbuf *m; 1788 size_t hdrsiz; 1789 struct ip *ip; 1790 struct tcphdr *th; 1791 1792 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1793 return (0); 1794 MGETHDR(m, MB_DONTWAIT, MT_DATA); 1795 if (!m) 1796 return (0); 1797 1798 #ifdef INET6 1799 if (inp->inp_vflag & INP_IPV6) { 1800 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 1801 1802 th = (struct tcphdr *)(ip6 + 1); 1803 m->m_pkthdr.len = m->m_len = 1804 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1805 tcp_fillheaders(tp, ip6, th, FALSE); 1806 hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1807 } else 1808 #endif 1809 { 1810 ip = mtod(m, struct ip *); 1811 th = (struct tcphdr *)(ip + 1); 1812 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1813 tcp_fillheaders(tp, ip, th, FALSE); 1814 hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1815 } 1816 1817 m_free(m); 1818 return (hdrsiz); 1819 } 1820 #endif 1821 1822 /* 1823 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1824 * 1825 * This code attempts to calculate the bandwidth-delay product as a 1826 * means of determining the optimal window size to maximize bandwidth, 1827 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1828 * routers. This code also does a fairly good job keeping RTTs in check 1829 * across slow links like modems. We implement an algorithm which is very 1830 * similar (but not meant to be) TCP/Vegas. The code operates on the 1831 * transmitter side of a TCP connection and so only effects the transmit 1832 * side of the connection. 1833 * 1834 * BACKGROUND: TCP makes no provision for the management of buffer space 1835 * at the end points or at the intermediate routers and switches. A TCP 1836 * stream, whether using NewReno or not, will eventually buffer as 1837 * many packets as it is able and the only reason this typically works is 1838 * due to the fairly small default buffers made available for a connection 1839 * (typicaly 16K or 32K). As machines use larger windows and/or window 1840 * scaling it is now fairly easy for even a single TCP connection to blow-out 1841 * all available buffer space not only on the local interface, but on 1842 * intermediate routers and switches as well. NewReno makes a misguided 1843 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1844 * then backing off, then steadily increasing the window again until another 1845 * failure occurs, ad-infinitum. This results in terrible oscillation that 1846 * is only made worse as network loads increase and the idea of intentionally 1847 * blowing out network buffers is, frankly, a terrible way to manage network 1848 * resources. 1849 * 1850 * It is far better to limit the transmit window prior to the failure 1851 * condition being achieved. There are two general ways to do this: First 1852 * you can 'scan' through different transmit window sizes and locate the 1853 * point where the RTT stops increasing, indicating that you have filled the 1854 * pipe, then scan backwards until you note that RTT stops decreasing, then 1855 * repeat ad-infinitum. This method works in principle but has severe 1856 * implementation issues due to RTT variances, timer granularity, and 1857 * instability in the algorithm which can lead to many false positives and 1858 * create oscillations as well as interact badly with other TCP streams 1859 * implementing the same algorithm. 1860 * 1861 * The second method is to limit the window to the bandwidth delay product 1862 * of the link. This is the method we implement. RTT variances and our 1863 * own manipulation of the congestion window, bwnd, can potentially 1864 * destabilize the algorithm. For this reason we have to stabilize the 1865 * elements used to calculate the window. We do this by using the minimum 1866 * observed RTT, the long term average of the observed bandwidth, and 1867 * by adding two segments worth of slop. It isn't perfect but it is able 1868 * to react to changing conditions and gives us a very stable basis on 1869 * which to extend the algorithm. 1870 */ 1871 void 1872 tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1873 { 1874 u_long bw; 1875 u_long bwnd; 1876 int save_ticks; 1877 int delta_ticks; 1878 1879 /* 1880 * If inflight_enable is disabled in the middle of a tcp connection, 1881 * make sure snd_bwnd is effectively disabled. 1882 */ 1883 if (!tcp_inflight_enable) { 1884 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1885 tp->snd_bandwidth = 0; 1886 return; 1887 } 1888 1889 /* 1890 * Validate the delta time. If a connection is new or has been idle 1891 * a long time we have to reset the bandwidth calculator. 1892 */ 1893 save_ticks = ticks; 1894 delta_ticks = save_ticks - tp->t_bw_rtttime; 1895 if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { 1896 tp->t_bw_rtttime = ticks; 1897 tp->t_bw_rtseq = ack_seq; 1898 if (tp->snd_bandwidth == 0) 1899 tp->snd_bandwidth = tcp_inflight_min; 1900 return; 1901 } 1902 if (delta_ticks == 0) 1903 return; 1904 1905 /* 1906 * Sanity check, plus ignore pure window update acks. 1907 */ 1908 if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) 1909 return; 1910 1911 /* 1912 * Figure out the bandwidth. Due to the tick granularity this 1913 * is a very rough number and it MUST be averaged over a fairly 1914 * long period of time. XXX we need to take into account a link 1915 * that is not using all available bandwidth, but for now our 1916 * slop will ramp us up if this case occurs and the bandwidth later 1917 * increases. 1918 */ 1919 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; 1920 tp->t_bw_rtttime = save_ticks; 1921 tp->t_bw_rtseq = ack_seq; 1922 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1923 1924 tp->snd_bandwidth = bw; 1925 1926 /* 1927 * Calculate the semi-static bandwidth delay product, plus two maximal 1928 * segments. The additional slop puts us squarely in the sweet 1929 * spot and also handles the bandwidth run-up case. Without the 1930 * slop we could be locking ourselves into a lower bandwidth. 1931 * 1932 * Situations Handled: 1933 * (1) Prevents over-queueing of packets on LANs, especially on 1934 * high speed LANs, allowing larger TCP buffers to be 1935 * specified, and also does a good job preventing 1936 * over-queueing of packets over choke points like modems 1937 * (at least for the transmit side). 1938 * 1939 * (2) Is able to handle changing network loads (bandwidth 1940 * drops so bwnd drops, bandwidth increases so bwnd 1941 * increases). 1942 * 1943 * (3) Theoretically should stabilize in the face of multiple 1944 * connections implementing the same algorithm (this may need 1945 * a little work). 1946 * 1947 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1948 * be adjusted with a sysctl but typically only needs to be on 1949 * very slow connections. A value no smaller then 5 should 1950 * be used, but only reduce this default if you have no other 1951 * choice. 1952 */ 1953 1954 #define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1955 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + 1956 tcp_inflight_stab * (int)tp->t_maxseg / 10; 1957 #undef USERTT 1958 1959 if (tcp_inflight_debug > 0) { 1960 static int ltime; 1961 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1962 ltime = ticks; 1963 kprintf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1964 tp, bw, tp->t_rttbest, tp->t_srtt, bwnd); 1965 } 1966 } 1967 if ((long)bwnd < tcp_inflight_min) 1968 bwnd = tcp_inflight_min; 1969 if (bwnd > tcp_inflight_max) 1970 bwnd = tcp_inflight_max; 1971 if ((long)bwnd < tp->t_maxseg * 2) 1972 bwnd = tp->t_maxseg * 2; 1973 tp->snd_bwnd = bwnd; 1974 } 1975 1976 static void 1977 tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs) 1978 { 1979 struct rtentry *rt; 1980 struct inpcb *inp = tp->t_inpcb; 1981 #ifdef INET6 1982 boolean_t isipv6 = ((inp->inp_vflag & INP_IPV6) ? TRUE : FALSE); 1983 #else 1984 const boolean_t isipv6 = FALSE; 1985 #endif 1986 1987 /* XXX */ 1988 if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT) 1989 tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; 1990 if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT) 1991 tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; 1992 1993 if (isipv6) 1994 rt = tcp_rtlookup6(&inp->inp_inc); 1995 else 1996 rt = tcp_rtlookup(&inp->inp_inc); 1997 if (rt == NULL || 1998 rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT || 1999 rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) { 2000 *maxsegs = tcp_iw_maxsegs; 2001 *capsegs = tcp_iw_capsegs; 2002 return; 2003 } 2004 *maxsegs = rt->rt_rmx.rmx_iwmaxsegs; 2005 *capsegs = rt->rt_rmx.rmx_iwcapsegs; 2006 } 2007 2008 u_long 2009 tcp_initial_window(struct tcpcb *tp) 2010 { 2011 if (tcp_do_rfc3390) { 2012 /* 2013 * RFC3390: 2014 * "If the SYN or SYN/ACK is lost, the initial window 2015 * used by a sender after a correctly transmitted SYN 2016 * MUST be one segment consisting of MSS bytes." 2017 * 2018 * However, we do something a little bit more aggressive 2019 * then RFC3390 here: 2020 * - Only if time spent in the SYN or SYN|ACK retransmition 2021 * >= 3 seconds, the IW is reduced. We do this mainly 2022 * because when RFC3390 is published, the initial RTO is 2023 * still 3 seconds (the threshold we test here), while 2024 * after RFC6298, the initial RTO is 1 second. This 2025 * behaviour probably still falls within the spirit of 2026 * RFC3390. 2027 * - When IW is reduced, 2*MSS is used instead of 1*MSS. 2028 * Mainly to avoid sender and receiver deadlock until 2029 * delayed ACK timer expires. And even RFC2581 does not 2030 * try to reduce IW upon SYN or SYN|ACK retransmition 2031 * timeout. 2032 * 2033 * See also: 2034 * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03 2035 */ 2036 if (tp->t_rxtsyn >= TCPTV_RTOBASE3) { 2037 return (2 * tp->t_maxseg); 2038 } else { 2039 u_long maxsegs, capsegs; 2040 2041 tcp_rmx_iwsegs(tp, &maxsegs, &capsegs); 2042 return min(maxsegs * tp->t_maxseg, 2043 max(2 * tp->t_maxseg, capsegs * 1460)); 2044 } 2045 } else { 2046 /* 2047 * Even RFC2581 (back to 1999) allows 2*SMSS IW. 2048 * 2049 * Mainly to avoid sender and receiver deadlock 2050 * until delayed ACK timer expires. 2051 */ 2052 return (2 * tp->t_maxseg); 2053 } 2054 } 2055 2056 #ifdef TCP_SIGNATURE 2057 /* 2058 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 2059 * 2060 * We do this over ip, tcphdr, segment data, and the key in the SADB. 2061 * When called from tcp_input(), we can be sure that th_sum has been 2062 * zeroed out and verified already. 2063 * 2064 * Return 0 if successful, otherwise return -1. 2065 * 2066 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2067 * search with the destination IP address, and a 'magic SPI' to be 2068 * determined by the application. This is hardcoded elsewhere to 1179 2069 * right now. Another branch of this code exists which uses the SPD to 2070 * specify per-application flows but it is unstable. 2071 */ 2072 int 2073 tcpsignature_compute( 2074 struct mbuf *m, /* mbuf chain */ 2075 int len, /* length of TCP data */ 2076 int optlen, /* length of TCP options */ 2077 u_char *buf, /* storage for MD5 digest */ 2078 u_int direction) /* direction of flow */ 2079 { 2080 struct ippseudo ippseudo; 2081 MD5_CTX ctx; 2082 int doff; 2083 struct ip *ip; 2084 struct ipovly *ipovly; 2085 struct secasvar *sav; 2086 struct tcphdr *th; 2087 #ifdef INET6 2088 struct ip6_hdr *ip6; 2089 struct in6_addr in6; 2090 uint32_t plen; 2091 uint16_t nhdr; 2092 #endif /* INET6 */ 2093 u_short savecsum; 2094 2095 KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); 2096 KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); 2097 /* 2098 * Extract the destination from the IP header in the mbuf. 2099 */ 2100 ip = mtod(m, struct ip *); 2101 #ifdef INET6 2102 ip6 = NULL; /* Make the compiler happy. */ 2103 #endif /* INET6 */ 2104 /* 2105 * Look up an SADB entry which matches the address found in 2106 * the segment. 2107 */ 2108 switch (IP_VHL_V(ip->ip_vhl)) { 2109 case IPVERSION: 2110 sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, 2111 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2112 break; 2113 #ifdef INET6 2114 case (IPV6_VERSION >> 4): 2115 ip6 = mtod(m, struct ip6_hdr *); 2116 sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, 2117 IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2118 break; 2119 #endif /* INET6 */ 2120 default: 2121 return (EINVAL); 2122 /* NOTREACHED */ 2123 break; 2124 } 2125 if (sav == NULL) { 2126 kprintf("%s: SADB lookup failed\n", __func__); 2127 return (EINVAL); 2128 } 2129 MD5Init(&ctx); 2130 2131 /* 2132 * Step 1: Update MD5 hash with IP pseudo-header. 2133 * 2134 * XXX The ippseudo header MUST be digested in network byte order, 2135 * or else we'll fail the regression test. Assume all fields we've 2136 * been doing arithmetic on have been in host byte order. 2137 * XXX One cannot depend on ipovly->ih_len here. When called from 2138 * tcp_output(), the underlying ip_len member has not yet been set. 2139 */ 2140 switch (IP_VHL_V(ip->ip_vhl)) { 2141 case IPVERSION: 2142 ipovly = (struct ipovly *)ip; 2143 ippseudo.ippseudo_src = ipovly->ih_src; 2144 ippseudo.ippseudo_dst = ipovly->ih_dst; 2145 ippseudo.ippseudo_pad = 0; 2146 ippseudo.ippseudo_p = IPPROTO_TCP; 2147 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); 2148 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2149 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2150 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2151 break; 2152 #ifdef INET6 2153 /* 2154 * RFC 2385, 2.0 Proposal 2155 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2156 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2157 * extended next header value (to form 32 bits), and 32-bit segment 2158 * length. 2159 * Note: Upper-Layer Packet Length comes before Next Header. 2160 */ 2161 case (IPV6_VERSION >> 4): 2162 in6 = ip6->ip6_src; 2163 in6_clearscope(&in6); 2164 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2165 in6 = ip6->ip6_dst; 2166 in6_clearscope(&in6); 2167 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2168 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2169 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2170 nhdr = 0; 2171 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2172 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2173 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2174 nhdr = IPPROTO_TCP; 2175 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2176 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2177 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2178 break; 2179 #endif /* INET6 */ 2180 default: 2181 return (EINVAL); 2182 /* NOTREACHED */ 2183 break; 2184 } 2185 /* 2186 * Step 2: Update MD5 hash with TCP header, excluding options. 2187 * The TCP checksum must be set to zero. 2188 */ 2189 savecsum = th->th_sum; 2190 th->th_sum = 0; 2191 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2192 th->th_sum = savecsum; 2193 /* 2194 * Step 3: Update MD5 hash with TCP segment data. 2195 * Use m_apply() to avoid an early m_pullup(). 2196 */ 2197 if (len > 0) 2198 m_apply(m, doff, len, tcpsignature_apply, &ctx); 2199 /* 2200 * Step 4: Update MD5 hash with shared secret. 2201 */ 2202 MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 2203 MD5Final(buf, &ctx); 2204 key_sa_recordxfer(sav, m); 2205 key_freesav(sav); 2206 return (0); 2207 } 2208 2209 int 2210 tcpsignature_apply(void *fstate, void *data, unsigned int len) 2211 { 2212 2213 MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); 2214 return (0); 2215 } 2216 #endif /* TCP_SIGNATURE */ 2217 2218 boolean_t 2219 tcp_tso_pullup(struct mbuf **mp, int hoff, struct ip **ip0, int *iphlen0, 2220 struct tcphdr **th0, int *thoff0) 2221 { 2222 struct mbuf *m = *mp; 2223 struct ip *ip; 2224 int len, iphlen; 2225 struct tcphdr *th; 2226 int thoff; 2227 2228 len = hoff + sizeof(struct ip); 2229 2230 /* The fixed IP header must reside completely in the first mbuf. */ 2231 if (m->m_len < len) { 2232 m = m_pullup(m, len); 2233 if (m == NULL) 2234 goto fail; 2235 } 2236 2237 ip = mtodoff(m, struct ip *, hoff); 2238 iphlen = IP_VHL_HL(ip->ip_vhl) << 2; 2239 2240 /* The full IP header must reside completely in the one mbuf. */ 2241 if (m->m_len < hoff + iphlen) { 2242 m = m_pullup(m, hoff + iphlen); 2243 if (m == NULL) 2244 goto fail; 2245 ip = mtodoff(m, struct ip *, hoff); 2246 } 2247 2248 KASSERT(ip->ip_p == IPPROTO_TCP, ("not tcp %d", ip->ip_p)); 2249 2250 if (m->m_len < hoff + iphlen + sizeof(struct tcphdr)) { 2251 m = m_pullup(m, hoff + iphlen + sizeof(struct tcphdr)); 2252 if (m == NULL) 2253 goto fail; 2254 ip = mtodoff(m, struct ip *, hoff); 2255 } 2256 2257 th = (struct tcphdr *)((caddr_t)ip + iphlen); 2258 thoff = th->th_off << 2; 2259 2260 if (m->m_len < hoff + iphlen + thoff) { 2261 m = m_pullup(m, hoff + iphlen + thoff); 2262 if (m == NULL) 2263 goto fail; 2264 ip = mtodoff(m, struct ip *, hoff); 2265 th = (struct tcphdr *)((caddr_t)ip + iphlen); 2266 } 2267 2268 *mp = m; 2269 *ip0 = ip; 2270 *iphlen0 = iphlen; 2271 *th0 = th; 2272 *thoff0 = thoff; 2273 return TRUE; 2274 2275 fail: 2276 if (m != NULL) 2277 m_freem(m); 2278 *mp = NULL; 2279 return FALSE; 2280 } 2281