1 /* 2 * TCP over IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * Based on: 9 * linux/net/ipv4/tcp.c 10 * linux/net/ipv4/tcp_input.c 11 * linux/net/ipv4/tcp_output.c 12 * 13 * Fixes: 14 * Hideaki YOSHIFUJI : sin6_scope_id support 15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind 17 * a single port at the same time. 18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file. 19 * 20 * This program is free software; you can redistribute it and/or 21 * modify it under the terms of the GNU General Public License 22 * as published by the Free Software Foundation; either version 23 * 2 of the License, or (at your option) any later version. 24 */ 25 26 #include <linux/bottom_half.h> 27 #include <linux/module.h> 28 #include <linux/errno.h> 29 #include <linux/types.h> 30 #include <linux/socket.h> 31 #include <linux/sockios.h> 32 #include <linux/net.h> 33 #include <linux/jiffies.h> 34 #include <linux/in.h> 35 #include <linux/in6.h> 36 #include <linux/netdevice.h> 37 #include <linux/init.h> 38 #include <linux/jhash.h> 39 #include <linux/ipsec.h> 40 #include <linux/times.h> 41 #include <linux/slab.h> 42 43 #include <linux/ipv6.h> 44 #include <linux/icmpv6.h> 45 #include <linux/random.h> 46 47 #include <net/tcp.h> 48 #include <net/ndisc.h> 49 #include <net/inet6_hashtables.h> 50 #include <net/inet6_connection_sock.h> 51 #include <net/ipv6.h> 52 #include <net/transp_v6.h> 53 #include <net/addrconf.h> 54 #include <net/ip6_route.h> 55 #include <net/ip6_checksum.h> 56 #include <net/inet_ecn.h> 57 #include <net/protocol.h> 58 #include <net/xfrm.h> 59 #include <net/snmp.h> 60 #include <net/dsfield.h> 61 #include <net/timewait_sock.h> 62 #include <net/netdma.h> 63 #include <net/inet_common.h> 64 #include <net/secure_seq.h> 65 #include <net/tcp_memcontrol.h> 66 67 #include <asm/uaccess.h> 68 69 #include <linux/proc_fs.h> 70 #include <linux/seq_file.h> 71 72 #include <linux/crypto.h> 73 #include <linux/scatterlist.h> 74 75 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb); 76 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 77 struct request_sock *req); 78 79 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); 80 static void __tcp_v6_send_check(struct sk_buff *skb, 81 const struct in6_addr *saddr, 82 const struct in6_addr *daddr); 83 84 static const struct inet_connection_sock_af_ops ipv6_mapped; 85 static const struct inet_connection_sock_af_ops ipv6_specific; 86 #ifdef CONFIG_TCP_MD5SIG 87 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; 88 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; 89 #else 90 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk, 91 const struct in6_addr *addr) 92 { 93 return NULL; 94 } 95 #endif 96 97 static void tcp_v6_hash(struct sock *sk) 98 { 99 if (sk->sk_state != TCP_CLOSE) { 100 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) { 101 tcp_prot.hash(sk); 102 return; 103 } 104 local_bh_disable(); 105 __inet6_hash(sk, NULL); 106 local_bh_enable(); 107 } 108 } 109 110 static __inline__ __sum16 tcp_v6_check(int len, 111 const struct in6_addr *saddr, 112 const struct in6_addr *daddr, 113 __wsum base) 114 { 115 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base); 116 } 117 118 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb) 119 { 120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32, 121 ipv6_hdr(skb)->saddr.s6_addr32, 122 tcp_hdr(skb)->dest, 123 tcp_hdr(skb)->source); 124 } 125 126 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 127 int addr_len) 128 { 129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 130 struct inet_sock *inet = inet_sk(sk); 131 struct inet_connection_sock *icsk = inet_csk(sk); 132 struct ipv6_pinfo *np = inet6_sk(sk); 133 struct tcp_sock *tp = tcp_sk(sk); 134 struct in6_addr *saddr = NULL, *final_p, final; 135 struct rt6_info *rt; 136 struct flowi6 fl6; 137 struct dst_entry *dst; 138 int addr_type; 139 int err; 140 141 if (addr_len < SIN6_LEN_RFC2133) 142 return -EINVAL; 143 144 if (usin->sin6_family != AF_INET6) 145 return -EAFNOSUPPORT; 146 147 memset(&fl6, 0, sizeof(fl6)); 148 149 if (np->sndflow) { 150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; 151 IP6_ECN_flow_init(fl6.flowlabel); 152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 153 struct ip6_flowlabel *flowlabel; 154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 155 if (flowlabel == NULL) 156 return -EINVAL; 157 usin->sin6_addr = flowlabel->dst; 158 fl6_sock_release(flowlabel); 159 } 160 } 161 162 /* 163 * connect() to INADDR_ANY means loopback (BSD'ism). 164 */ 165 166 if(ipv6_addr_any(&usin->sin6_addr)) 167 usin->sin6_addr.s6_addr[15] = 0x1; 168 169 addr_type = ipv6_addr_type(&usin->sin6_addr); 170 171 if(addr_type & IPV6_ADDR_MULTICAST) 172 return -ENETUNREACH; 173 174 if (addr_type&IPV6_ADDR_LINKLOCAL) { 175 if (addr_len >= sizeof(struct sockaddr_in6) && 176 usin->sin6_scope_id) { 177 /* If interface is set while binding, indices 178 * must coincide. 179 */ 180 if (sk->sk_bound_dev_if && 181 sk->sk_bound_dev_if != usin->sin6_scope_id) 182 return -EINVAL; 183 184 sk->sk_bound_dev_if = usin->sin6_scope_id; 185 } 186 187 /* Connect to link-local address requires an interface */ 188 if (!sk->sk_bound_dev_if) 189 return -EINVAL; 190 } 191 192 if (tp->rx_opt.ts_recent_stamp && 193 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) { 194 tp->rx_opt.ts_recent = 0; 195 tp->rx_opt.ts_recent_stamp = 0; 196 tp->write_seq = 0; 197 } 198 199 np->daddr = usin->sin6_addr; 200 np->flow_label = fl6.flowlabel; 201 202 /* 203 * TCP over IPv4 204 */ 205 206 if (addr_type == IPV6_ADDR_MAPPED) { 207 u32 exthdrlen = icsk->icsk_ext_hdr_len; 208 struct sockaddr_in sin; 209 210 SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); 211 212 if (__ipv6_only_sock(sk)) 213 return -ENETUNREACH; 214 215 sin.sin_family = AF_INET; 216 sin.sin_port = usin->sin6_port; 217 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 218 219 icsk->icsk_af_ops = &ipv6_mapped; 220 sk->sk_backlog_rcv = tcp_v4_do_rcv; 221 #ifdef CONFIG_TCP_MD5SIG 222 tp->af_specific = &tcp_sock_ipv6_mapped_specific; 223 #endif 224 225 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 226 227 if (err) { 228 icsk->icsk_ext_hdr_len = exthdrlen; 229 icsk->icsk_af_ops = &ipv6_specific; 230 sk->sk_backlog_rcv = tcp_v6_do_rcv; 231 #ifdef CONFIG_TCP_MD5SIG 232 tp->af_specific = &tcp_sock_ipv6_specific; 233 #endif 234 goto failure; 235 } else { 236 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr); 237 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, 238 &np->rcv_saddr); 239 } 240 241 return err; 242 } 243 244 if (!ipv6_addr_any(&np->rcv_saddr)) 245 saddr = &np->rcv_saddr; 246 247 fl6.flowi6_proto = IPPROTO_TCP; 248 fl6.daddr = np->daddr; 249 fl6.saddr = saddr ? *saddr : np->saddr; 250 fl6.flowi6_oif = sk->sk_bound_dev_if; 251 fl6.flowi6_mark = sk->sk_mark; 252 fl6.fl6_dport = usin->sin6_port; 253 fl6.fl6_sport = inet->inet_sport; 254 255 final_p = fl6_update_dst(&fl6, np->opt, &final); 256 257 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 258 259 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true); 260 if (IS_ERR(dst)) { 261 err = PTR_ERR(dst); 262 goto failure; 263 } 264 265 if (saddr == NULL) { 266 saddr = &fl6.saddr; 267 np->rcv_saddr = *saddr; 268 } 269 270 /* set the source address */ 271 np->saddr = *saddr; 272 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 273 274 sk->sk_gso_type = SKB_GSO_TCPV6; 275 __ip6_dst_store(sk, dst, NULL, NULL); 276 277 rt = (struct rt6_info *) dst; 278 if (tcp_death_row.sysctl_tw_recycle && 279 !tp->rx_opt.ts_recent_stamp && 280 ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) { 281 struct inet_peer *peer = rt6_get_peer(rt); 282 /* 283 * VJ's idea. We save last timestamp seen from 284 * the destination in peer table, when entering state 285 * TIME-WAIT * and initialize rx_opt.ts_recent from it, 286 * when trying new connection. 287 */ 288 if (peer) { 289 inet_peer_refcheck(peer); 290 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) { 291 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp; 292 tp->rx_opt.ts_recent = peer->tcp_ts; 293 } 294 } 295 } 296 297 icsk->icsk_ext_hdr_len = 0; 298 if (np->opt) 299 icsk->icsk_ext_hdr_len = (np->opt->opt_flen + 300 np->opt->opt_nflen); 301 302 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); 303 304 inet->inet_dport = usin->sin6_port; 305 306 tcp_set_state(sk, TCP_SYN_SENT); 307 err = inet6_hash_connect(&tcp_death_row, sk); 308 if (err) 309 goto late_failure; 310 311 if (!tp->write_seq) 312 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32, 313 np->daddr.s6_addr32, 314 inet->inet_sport, 315 inet->inet_dport); 316 317 err = tcp_connect(sk); 318 if (err) 319 goto late_failure; 320 321 return 0; 322 323 late_failure: 324 tcp_set_state(sk, TCP_CLOSE); 325 __sk_dst_reset(sk); 326 failure: 327 inet->inet_dport = 0; 328 sk->sk_route_caps = 0; 329 return err; 330 } 331 332 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 333 u8 type, u8 code, int offset, __be32 info) 334 { 335 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data; 336 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); 337 struct ipv6_pinfo *np; 338 struct sock *sk; 339 int err; 340 struct tcp_sock *tp; 341 __u32 seq; 342 struct net *net = dev_net(skb->dev); 343 344 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr, 345 th->dest, &hdr->saddr, th->source, skb->dev->ifindex); 346 347 if (sk == NULL) { 348 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), 349 ICMP6_MIB_INERRORS); 350 return; 351 } 352 353 if (sk->sk_state == TCP_TIME_WAIT) { 354 inet_twsk_put(inet_twsk(sk)); 355 return; 356 } 357 358 bh_lock_sock(sk); 359 if (sock_owned_by_user(sk)) 360 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); 361 362 if (sk->sk_state == TCP_CLOSE) 363 goto out; 364 365 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) { 366 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); 367 goto out; 368 } 369 370 tp = tcp_sk(sk); 371 seq = ntohl(th->seq); 372 if (sk->sk_state != TCP_LISTEN && 373 !between(seq, tp->snd_una, tp->snd_nxt)) { 374 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); 375 goto out; 376 } 377 378 np = inet6_sk(sk); 379 380 if (type == ICMPV6_PKT_TOOBIG) { 381 struct dst_entry *dst; 382 383 if (sock_owned_by_user(sk)) 384 goto out; 385 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) 386 goto out; 387 388 /* icmp should have updated the destination cache entry */ 389 dst = __sk_dst_check(sk, np->dst_cookie); 390 391 if (dst == NULL) { 392 struct inet_sock *inet = inet_sk(sk); 393 struct flowi6 fl6; 394 395 /* BUGGG_FUTURE: Again, it is not clear how 396 to handle rthdr case. Ignore this complexity 397 for now. 398 */ 399 memset(&fl6, 0, sizeof(fl6)); 400 fl6.flowi6_proto = IPPROTO_TCP; 401 fl6.daddr = np->daddr; 402 fl6.saddr = np->saddr; 403 fl6.flowi6_oif = sk->sk_bound_dev_if; 404 fl6.flowi6_mark = sk->sk_mark; 405 fl6.fl6_dport = inet->inet_dport; 406 fl6.fl6_sport = inet->inet_sport; 407 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 408 409 dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false); 410 if (IS_ERR(dst)) { 411 sk->sk_err_soft = -PTR_ERR(dst); 412 goto out; 413 } 414 415 } else 416 dst_hold(dst); 417 418 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { 419 tcp_sync_mss(sk, dst_mtu(dst)); 420 tcp_simple_retransmit(sk); 421 } /* else let the usual retransmit timer handle it */ 422 dst_release(dst); 423 goto out; 424 } 425 426 icmpv6_err_convert(type, code, &err); 427 428 /* Might be for an request_sock */ 429 switch (sk->sk_state) { 430 struct request_sock *req, **prev; 431 case TCP_LISTEN: 432 if (sock_owned_by_user(sk)) 433 goto out; 434 435 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr, 436 &hdr->saddr, inet6_iif(skb)); 437 if (!req) 438 goto out; 439 440 /* ICMPs are not backlogged, hence we cannot get 441 * an established socket here. 442 */ 443 WARN_ON(req->sk != NULL); 444 445 if (seq != tcp_rsk(req)->snt_isn) { 446 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); 447 goto out; 448 } 449 450 inet_csk_reqsk_queue_drop(sk, req, prev); 451 goto out; 452 453 case TCP_SYN_SENT: 454 case TCP_SYN_RECV: /* Cannot happen. 455 It can, it SYNs are crossed. --ANK */ 456 if (!sock_owned_by_user(sk)) { 457 sk->sk_err = err; 458 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ 459 460 tcp_done(sk); 461 } else 462 sk->sk_err_soft = err; 463 goto out; 464 } 465 466 if (!sock_owned_by_user(sk) && np->recverr) { 467 sk->sk_err = err; 468 sk->sk_error_report(sk); 469 } else 470 sk->sk_err_soft = err; 471 472 out: 473 bh_unlock_sock(sk); 474 sock_put(sk); 475 } 476 477 478 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req, 479 struct request_values *rvp, 480 u16 queue_mapping) 481 { 482 struct inet6_request_sock *treq = inet6_rsk(req); 483 struct ipv6_pinfo *np = inet6_sk(sk); 484 struct sk_buff * skb; 485 struct ipv6_txoptions *opt = NULL; 486 struct in6_addr * final_p, final; 487 struct flowi6 fl6; 488 struct dst_entry *dst; 489 int err; 490 491 memset(&fl6, 0, sizeof(fl6)); 492 fl6.flowi6_proto = IPPROTO_TCP; 493 fl6.daddr = treq->rmt_addr; 494 fl6.saddr = treq->loc_addr; 495 fl6.flowlabel = 0; 496 fl6.flowi6_oif = treq->iif; 497 fl6.flowi6_mark = sk->sk_mark; 498 fl6.fl6_dport = inet_rsk(req)->rmt_port; 499 fl6.fl6_sport = inet_rsk(req)->loc_port; 500 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 501 502 opt = np->opt; 503 final_p = fl6_update_dst(&fl6, opt, &final); 504 505 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false); 506 if (IS_ERR(dst)) { 507 err = PTR_ERR(dst); 508 dst = NULL; 509 goto done; 510 } 511 skb = tcp_make_synack(sk, dst, req, rvp); 512 err = -ENOMEM; 513 if (skb) { 514 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr); 515 516 fl6.daddr = treq->rmt_addr; 517 skb_set_queue_mapping(skb, queue_mapping); 518 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass); 519 err = net_xmit_eval(err); 520 } 521 522 done: 523 if (opt && opt != np->opt) 524 sock_kfree_s(sk, opt, opt->tot_len); 525 dst_release(dst); 526 return err; 527 } 528 529 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req, 530 struct request_values *rvp) 531 { 532 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); 533 return tcp_v6_send_synack(sk, req, rvp, 0); 534 } 535 536 static void tcp_v6_reqsk_destructor(struct request_sock *req) 537 { 538 kfree_skb(inet6_rsk(req)->pktopts); 539 } 540 541 #ifdef CONFIG_TCP_MD5SIG 542 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk, 543 const struct in6_addr *addr) 544 { 545 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6); 546 } 547 548 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk, 549 struct sock *addr_sk) 550 { 551 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr); 552 } 553 554 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk, 555 struct request_sock *req) 556 { 557 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr); 558 } 559 560 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval, 561 int optlen) 562 { 563 struct tcp_md5sig cmd; 564 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; 565 566 if (optlen < sizeof(cmd)) 567 return -EINVAL; 568 569 if (copy_from_user(&cmd, optval, sizeof(cmd))) 570 return -EFAULT; 571 572 if (sin6->sin6_family != AF_INET6) 573 return -EINVAL; 574 575 if (!cmd.tcpm_keylen) { 576 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 577 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 578 AF_INET); 579 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 580 AF_INET6); 581 } 582 583 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) 584 return -EINVAL; 585 586 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 587 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 588 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); 589 590 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 591 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); 592 } 593 594 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, 595 const struct in6_addr *daddr, 596 const struct in6_addr *saddr, int nbytes) 597 { 598 struct tcp6_pseudohdr *bp; 599 struct scatterlist sg; 600 601 bp = &hp->md5_blk.ip6; 602 /* 1. TCP pseudo-header (RFC2460) */ 603 bp->saddr = *saddr; 604 bp->daddr = *daddr; 605 bp->protocol = cpu_to_be32(IPPROTO_TCP); 606 bp->len = cpu_to_be32(nbytes); 607 608 sg_init_one(&sg, bp, sizeof(*bp)); 609 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); 610 } 611 612 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key, 613 const struct in6_addr *daddr, struct in6_addr *saddr, 614 const struct tcphdr *th) 615 { 616 struct tcp_md5sig_pool *hp; 617 struct hash_desc *desc; 618 619 hp = tcp_get_md5sig_pool(); 620 if (!hp) 621 goto clear_hash_noput; 622 desc = &hp->md5_desc; 623 624 if (crypto_hash_init(desc)) 625 goto clear_hash; 626 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) 627 goto clear_hash; 628 if (tcp_md5_hash_header(hp, th)) 629 goto clear_hash; 630 if (tcp_md5_hash_key(hp, key)) 631 goto clear_hash; 632 if (crypto_hash_final(desc, md5_hash)) 633 goto clear_hash; 634 635 tcp_put_md5sig_pool(); 636 return 0; 637 638 clear_hash: 639 tcp_put_md5sig_pool(); 640 clear_hash_noput: 641 memset(md5_hash, 0, 16); 642 return 1; 643 } 644 645 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, 646 const struct sock *sk, 647 const struct request_sock *req, 648 const struct sk_buff *skb) 649 { 650 const struct in6_addr *saddr, *daddr; 651 struct tcp_md5sig_pool *hp; 652 struct hash_desc *desc; 653 const struct tcphdr *th = tcp_hdr(skb); 654 655 if (sk) { 656 saddr = &inet6_sk(sk)->saddr; 657 daddr = &inet6_sk(sk)->daddr; 658 } else if (req) { 659 saddr = &inet6_rsk(req)->loc_addr; 660 daddr = &inet6_rsk(req)->rmt_addr; 661 } else { 662 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 663 saddr = &ip6h->saddr; 664 daddr = &ip6h->daddr; 665 } 666 667 hp = tcp_get_md5sig_pool(); 668 if (!hp) 669 goto clear_hash_noput; 670 desc = &hp->md5_desc; 671 672 if (crypto_hash_init(desc)) 673 goto clear_hash; 674 675 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) 676 goto clear_hash; 677 if (tcp_md5_hash_header(hp, th)) 678 goto clear_hash; 679 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) 680 goto clear_hash; 681 if (tcp_md5_hash_key(hp, key)) 682 goto clear_hash; 683 if (crypto_hash_final(desc, md5_hash)) 684 goto clear_hash; 685 686 tcp_put_md5sig_pool(); 687 return 0; 688 689 clear_hash: 690 tcp_put_md5sig_pool(); 691 clear_hash_noput: 692 memset(md5_hash, 0, 16); 693 return 1; 694 } 695 696 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb) 697 { 698 const __u8 *hash_location = NULL; 699 struct tcp_md5sig_key *hash_expected; 700 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 701 const struct tcphdr *th = tcp_hdr(skb); 702 int genhash; 703 u8 newhash[16]; 704 705 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr); 706 hash_location = tcp_parse_md5sig_option(th); 707 708 /* We've parsed the options - do we have a hash? */ 709 if (!hash_expected && !hash_location) 710 return 0; 711 712 if (hash_expected && !hash_location) { 713 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); 714 return 1; 715 } 716 717 if (!hash_expected && hash_location) { 718 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); 719 return 1; 720 } 721 722 /* check the signature */ 723 genhash = tcp_v6_md5_hash_skb(newhash, 724 hash_expected, 725 NULL, NULL, skb); 726 727 if (genhash || memcmp(hash_location, newhash, 16) != 0) { 728 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n", 729 genhash ? "failed" : "mismatch", 730 &ip6h->saddr, ntohs(th->source), 731 &ip6h->daddr, ntohs(th->dest)); 732 return 1; 733 } 734 return 0; 735 } 736 #endif 737 738 struct request_sock_ops tcp6_request_sock_ops __read_mostly = { 739 .family = AF_INET6, 740 .obj_size = sizeof(struct tcp6_request_sock), 741 .rtx_syn_ack = tcp_v6_rtx_synack, 742 .send_ack = tcp_v6_reqsk_send_ack, 743 .destructor = tcp_v6_reqsk_destructor, 744 .send_reset = tcp_v6_send_reset, 745 .syn_ack_timeout = tcp_syn_ack_timeout, 746 }; 747 748 #ifdef CONFIG_TCP_MD5SIG 749 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { 750 .md5_lookup = tcp_v6_reqsk_md5_lookup, 751 .calc_md5_hash = tcp_v6_md5_hash_skb, 752 }; 753 #endif 754 755 static void __tcp_v6_send_check(struct sk_buff *skb, 756 const struct in6_addr *saddr, const struct in6_addr *daddr) 757 { 758 struct tcphdr *th = tcp_hdr(skb); 759 760 if (skb->ip_summed == CHECKSUM_PARTIAL) { 761 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0); 762 skb->csum_start = skb_transport_header(skb) - skb->head; 763 skb->csum_offset = offsetof(struct tcphdr, check); 764 } else { 765 th->check = tcp_v6_check(skb->len, saddr, daddr, 766 csum_partial(th, th->doff << 2, 767 skb->csum)); 768 } 769 } 770 771 static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) 772 { 773 struct ipv6_pinfo *np = inet6_sk(sk); 774 775 __tcp_v6_send_check(skb, &np->saddr, &np->daddr); 776 } 777 778 static int tcp_v6_gso_send_check(struct sk_buff *skb) 779 { 780 const struct ipv6hdr *ipv6h; 781 struct tcphdr *th; 782 783 if (!pskb_may_pull(skb, sizeof(*th))) 784 return -EINVAL; 785 786 ipv6h = ipv6_hdr(skb); 787 th = tcp_hdr(skb); 788 789 th->check = 0; 790 skb->ip_summed = CHECKSUM_PARTIAL; 791 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr); 792 return 0; 793 } 794 795 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head, 796 struct sk_buff *skb) 797 { 798 const struct ipv6hdr *iph = skb_gro_network_header(skb); 799 800 switch (skb->ip_summed) { 801 case CHECKSUM_COMPLETE: 802 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr, 803 skb->csum)) { 804 skb->ip_summed = CHECKSUM_UNNECESSARY; 805 break; 806 } 807 808 /* fall through */ 809 case CHECKSUM_NONE: 810 NAPI_GRO_CB(skb)->flush = 1; 811 return NULL; 812 } 813 814 return tcp_gro_receive(head, skb); 815 } 816 817 static int tcp6_gro_complete(struct sk_buff *skb) 818 { 819 const struct ipv6hdr *iph = ipv6_hdr(skb); 820 struct tcphdr *th = tcp_hdr(skb); 821 822 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb), 823 &iph->saddr, &iph->daddr, 0); 824 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 825 826 return tcp_gro_complete(skb); 827 } 828 829 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, 830 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass) 831 { 832 const struct tcphdr *th = tcp_hdr(skb); 833 struct tcphdr *t1; 834 struct sk_buff *buff; 835 struct flowi6 fl6; 836 struct net *net = dev_net(skb_dst(skb)->dev); 837 struct sock *ctl_sk = net->ipv6.tcp_sk; 838 unsigned int tot_len = sizeof(struct tcphdr); 839 struct dst_entry *dst; 840 __be32 *topt; 841 842 if (ts) 843 tot_len += TCPOLEN_TSTAMP_ALIGNED; 844 #ifdef CONFIG_TCP_MD5SIG 845 if (key) 846 tot_len += TCPOLEN_MD5SIG_ALIGNED; 847 #endif 848 849 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len, 850 GFP_ATOMIC); 851 if (buff == NULL) 852 return; 853 854 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len); 855 856 t1 = (struct tcphdr *) skb_push(buff, tot_len); 857 skb_reset_transport_header(buff); 858 859 /* Swap the send and the receive. */ 860 memset(t1, 0, sizeof(*t1)); 861 t1->dest = th->source; 862 t1->source = th->dest; 863 t1->doff = tot_len / 4; 864 t1->seq = htonl(seq); 865 t1->ack_seq = htonl(ack); 866 t1->ack = !rst || !th->ack; 867 t1->rst = rst; 868 t1->window = htons(win); 869 870 topt = (__be32 *)(t1 + 1); 871 872 if (ts) { 873 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 874 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); 875 *topt++ = htonl(tcp_time_stamp); 876 *topt++ = htonl(ts); 877 } 878 879 #ifdef CONFIG_TCP_MD5SIG 880 if (key) { 881 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 882 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); 883 tcp_v6_md5_hash_hdr((__u8 *)topt, key, 884 &ipv6_hdr(skb)->saddr, 885 &ipv6_hdr(skb)->daddr, t1); 886 } 887 #endif 888 889 memset(&fl6, 0, sizeof(fl6)); 890 fl6.daddr = ipv6_hdr(skb)->saddr; 891 fl6.saddr = ipv6_hdr(skb)->daddr; 892 893 buff->ip_summed = CHECKSUM_PARTIAL; 894 buff->csum = 0; 895 896 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); 897 898 fl6.flowi6_proto = IPPROTO_TCP; 899 fl6.flowi6_oif = inet6_iif(skb); 900 fl6.fl6_dport = t1->dest; 901 fl6.fl6_sport = t1->source; 902 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 903 904 /* Pass a socket to ip6_dst_lookup either it is for RST 905 * Underlying function will use this to retrieve the network 906 * namespace 907 */ 908 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false); 909 if (!IS_ERR(dst)) { 910 skb_dst_set(buff, dst); 911 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass); 912 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); 913 if (rst) 914 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); 915 return; 916 } 917 918 kfree_skb(buff); 919 } 920 921 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 922 { 923 const struct tcphdr *th = tcp_hdr(skb); 924 u32 seq = 0, ack_seq = 0; 925 struct tcp_md5sig_key *key = NULL; 926 #ifdef CONFIG_TCP_MD5SIG 927 const __u8 *hash_location = NULL; 928 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 929 unsigned char newhash[16]; 930 int genhash; 931 struct sock *sk1 = NULL; 932 #endif 933 934 if (th->rst) 935 return; 936 937 if (!ipv6_unicast_destination(skb)) 938 return; 939 940 #ifdef CONFIG_TCP_MD5SIG 941 hash_location = tcp_parse_md5sig_option(th); 942 if (!sk && hash_location) { 943 /* 944 * active side is lost. Try to find listening socket through 945 * source port, and then find md5 key through listening socket. 946 * we are not loose security here: 947 * Incoming packet is checked with md5 hash with finding key, 948 * no RST generated if md5 hash doesn't match. 949 */ 950 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev), 951 &tcp_hashinfo, &ipv6h->daddr, 952 ntohs(th->source), inet6_iif(skb)); 953 if (!sk1) 954 return; 955 956 rcu_read_lock(); 957 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr); 958 if (!key) 959 goto release_sk1; 960 961 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb); 962 if (genhash || memcmp(hash_location, newhash, 16) != 0) 963 goto release_sk1; 964 } else { 965 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL; 966 } 967 #endif 968 969 if (th->ack) 970 seq = ntohl(th->ack_seq); 971 else 972 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - 973 (th->doff << 2); 974 975 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0); 976 977 #ifdef CONFIG_TCP_MD5SIG 978 release_sk1: 979 if (sk1) { 980 rcu_read_unlock(); 981 sock_put(sk1); 982 } 983 #endif 984 } 985 986 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts, 987 struct tcp_md5sig_key *key, u8 tclass) 988 { 989 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass); 990 } 991 992 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) 993 { 994 struct inet_timewait_sock *tw = inet_twsk(sk); 995 struct tcp_timewait_sock *tcptw = tcp_twsk(sk); 996 997 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, 998 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, 999 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw), 1000 tw->tw_tclass); 1001 1002 inet_twsk_put(tw); 1003 } 1004 1005 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 1006 struct request_sock *req) 1007 { 1008 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent, 1009 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0); 1010 } 1011 1012 1013 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb) 1014 { 1015 struct request_sock *req, **prev; 1016 const struct tcphdr *th = tcp_hdr(skb); 1017 struct sock *nsk; 1018 1019 /* Find possible connection requests. */ 1020 req = inet6_csk_search_req(sk, &prev, th->source, 1021 &ipv6_hdr(skb)->saddr, 1022 &ipv6_hdr(skb)->daddr, inet6_iif(skb)); 1023 if (req) 1024 return tcp_check_req(sk, skb, req, prev); 1025 1026 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo, 1027 &ipv6_hdr(skb)->saddr, th->source, 1028 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb)); 1029 1030 if (nsk) { 1031 if (nsk->sk_state != TCP_TIME_WAIT) { 1032 bh_lock_sock(nsk); 1033 return nsk; 1034 } 1035 inet_twsk_put(inet_twsk(nsk)); 1036 return NULL; 1037 } 1038 1039 #ifdef CONFIG_SYN_COOKIES 1040 if (!th->syn) 1041 sk = cookie_v6_check(sk, skb); 1042 #endif 1043 return sk; 1044 } 1045 1046 /* FIXME: this is substantially similar to the ipv4 code. 1047 * Can some kind of merge be done? -- erics 1048 */ 1049 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 1050 { 1051 struct tcp_extend_values tmp_ext; 1052 struct tcp_options_received tmp_opt; 1053 const u8 *hash_location; 1054 struct request_sock *req; 1055 struct inet6_request_sock *treq; 1056 struct ipv6_pinfo *np = inet6_sk(sk); 1057 struct tcp_sock *tp = tcp_sk(sk); 1058 __u32 isn = TCP_SKB_CB(skb)->when; 1059 struct dst_entry *dst = NULL; 1060 bool want_cookie = false; 1061 1062 if (skb->protocol == htons(ETH_P_IP)) 1063 return tcp_v4_conn_request(sk, skb); 1064 1065 if (!ipv6_unicast_destination(skb)) 1066 goto drop; 1067 1068 if (inet_csk_reqsk_queue_is_full(sk) && !isn) { 1069 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6"); 1070 if (!want_cookie) 1071 goto drop; 1072 } 1073 1074 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) 1075 goto drop; 1076 1077 req = inet6_reqsk_alloc(&tcp6_request_sock_ops); 1078 if (req == NULL) 1079 goto drop; 1080 1081 #ifdef CONFIG_TCP_MD5SIG 1082 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops; 1083 #endif 1084 1085 tcp_clear_options(&tmp_opt); 1086 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); 1087 tmp_opt.user_mss = tp->rx_opt.user_mss; 1088 tcp_parse_options(skb, &tmp_opt, &hash_location, 0); 1089 1090 if (tmp_opt.cookie_plus > 0 && 1091 tmp_opt.saw_tstamp && 1092 !tp->rx_opt.cookie_out_never && 1093 (sysctl_tcp_cookie_size > 0 || 1094 (tp->cookie_values != NULL && 1095 tp->cookie_values->cookie_desired > 0))) { 1096 u8 *c; 1097 u32 *d; 1098 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS]; 1099 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE; 1100 1101 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0) 1102 goto drop_and_free; 1103 1104 /* Secret recipe starts with IP addresses */ 1105 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0]; 1106 *mess++ ^= *d++; 1107 *mess++ ^= *d++; 1108 *mess++ ^= *d++; 1109 *mess++ ^= *d++; 1110 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0]; 1111 *mess++ ^= *d++; 1112 *mess++ ^= *d++; 1113 *mess++ ^= *d++; 1114 *mess++ ^= *d++; 1115 1116 /* plus variable length Initiator Cookie */ 1117 c = (u8 *)mess; 1118 while (l-- > 0) 1119 *c++ ^= *hash_location++; 1120 1121 want_cookie = false; /* not our kind of cookie */ 1122 tmp_ext.cookie_out_never = 0; /* false */ 1123 tmp_ext.cookie_plus = tmp_opt.cookie_plus; 1124 } else if (!tp->rx_opt.cookie_in_always) { 1125 /* redundant indications, but ensure initialization. */ 1126 tmp_ext.cookie_out_never = 1; /* true */ 1127 tmp_ext.cookie_plus = 0; 1128 } else { 1129 goto drop_and_free; 1130 } 1131 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; 1132 1133 if (want_cookie && !tmp_opt.saw_tstamp) 1134 tcp_clear_options(&tmp_opt); 1135 1136 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; 1137 tcp_openreq_init(req, &tmp_opt, skb); 1138 1139 treq = inet6_rsk(req); 1140 treq->rmt_addr = ipv6_hdr(skb)->saddr; 1141 treq->loc_addr = ipv6_hdr(skb)->daddr; 1142 if (!want_cookie || tmp_opt.tstamp_ok) 1143 TCP_ECN_create_request(req, skb); 1144 1145 treq->iif = sk->sk_bound_dev_if; 1146 1147 /* So that link locals have meaning */ 1148 if (!sk->sk_bound_dev_if && 1149 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL) 1150 treq->iif = inet6_iif(skb); 1151 1152 if (!isn) { 1153 struct inet_peer *peer = NULL; 1154 1155 if (ipv6_opt_accepted(sk, skb) || 1156 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 1157 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 1158 atomic_inc(&skb->users); 1159 treq->pktopts = skb; 1160 } 1161 1162 if (want_cookie) { 1163 isn = cookie_v6_init_sequence(sk, skb, &req->mss); 1164 req->cookie_ts = tmp_opt.tstamp_ok; 1165 goto have_isn; 1166 } 1167 1168 /* VJ's idea. We save last timestamp seen 1169 * from the destination in peer table, when entering 1170 * state TIME-WAIT, and check against it before 1171 * accepting new connection request. 1172 * 1173 * If "isn" is not zero, this request hit alive 1174 * timewait bucket, so that all the necessary checks 1175 * are made in the function processing timewait state. 1176 */ 1177 if (tmp_opt.saw_tstamp && 1178 tcp_death_row.sysctl_tw_recycle && 1179 (dst = inet6_csk_route_req(sk, req)) != NULL && 1180 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL && 1181 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6, 1182 &treq->rmt_addr)) { 1183 inet_peer_refcheck(peer); 1184 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL && 1185 (s32)(peer->tcp_ts - req->ts_recent) > 1186 TCP_PAWS_WINDOW) { 1187 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); 1188 goto drop_and_release; 1189 } 1190 } 1191 /* Kill the following clause, if you dislike this way. */ 1192 else if (!sysctl_tcp_syncookies && 1193 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < 1194 (sysctl_max_syn_backlog >> 2)) && 1195 (!peer || !peer->tcp_ts_stamp) && 1196 (!dst || !dst_metric(dst, RTAX_RTT))) { 1197 /* Without syncookies last quarter of 1198 * backlog is filled with destinations, 1199 * proven to be alive. 1200 * It means that we continue to communicate 1201 * to destinations, already remembered 1202 * to the moment of synflood. 1203 */ 1204 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n", 1205 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source)); 1206 goto drop_and_release; 1207 } 1208 1209 isn = tcp_v6_init_sequence(skb); 1210 } 1211 have_isn: 1212 tcp_rsk(req)->snt_isn = isn; 1213 tcp_rsk(req)->snt_synack = tcp_time_stamp; 1214 1215 if (security_inet_conn_request(sk, skb, req)) 1216 goto drop_and_release; 1217 1218 if (tcp_v6_send_synack(sk, req, 1219 (struct request_values *)&tmp_ext, 1220 skb_get_queue_mapping(skb)) || 1221 want_cookie) 1222 goto drop_and_free; 1223 1224 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); 1225 return 0; 1226 1227 drop_and_release: 1228 dst_release(dst); 1229 drop_and_free: 1230 reqsk_free(req); 1231 drop: 1232 return 0; /* don't send reset */ 1233 } 1234 1235 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, 1236 struct request_sock *req, 1237 struct dst_entry *dst) 1238 { 1239 struct inet6_request_sock *treq; 1240 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 1241 struct tcp6_sock *newtcp6sk; 1242 struct inet_sock *newinet; 1243 struct tcp_sock *newtp; 1244 struct sock *newsk; 1245 struct ipv6_txoptions *opt; 1246 #ifdef CONFIG_TCP_MD5SIG 1247 struct tcp_md5sig_key *key; 1248 #endif 1249 1250 if (skb->protocol == htons(ETH_P_IP)) { 1251 /* 1252 * v6 mapped 1253 */ 1254 1255 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst); 1256 1257 if (newsk == NULL) 1258 return NULL; 1259 1260 newtcp6sk = (struct tcp6_sock *)newsk; 1261 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6; 1262 1263 newinet = inet_sk(newsk); 1264 newnp = inet6_sk(newsk); 1265 newtp = tcp_sk(newsk); 1266 1267 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1268 1269 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr); 1270 1271 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr); 1272 1273 newnp->rcv_saddr = newnp->saddr; 1274 1275 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; 1276 newsk->sk_backlog_rcv = tcp_v4_do_rcv; 1277 #ifdef CONFIG_TCP_MD5SIG 1278 newtp->af_specific = &tcp_sock_ipv6_mapped_specific; 1279 #endif 1280 1281 newnp->ipv6_ac_list = NULL; 1282 newnp->ipv6_fl_list = NULL; 1283 newnp->pktoptions = NULL; 1284 newnp->opt = NULL; 1285 newnp->mcast_oif = inet6_iif(skb); 1286 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1287 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb)); 1288 1289 /* 1290 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 1291 * here, tcp_create_openreq_child now does this for us, see the comment in 1292 * that function for the gory details. -acme 1293 */ 1294 1295 /* It is tricky place. Until this moment IPv4 tcp 1296 worked with IPv6 icsk.icsk_af_ops. 1297 Sync it now. 1298 */ 1299 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 1300 1301 return newsk; 1302 } 1303 1304 treq = inet6_rsk(req); 1305 opt = np->opt; 1306 1307 if (sk_acceptq_is_full(sk)) 1308 goto out_overflow; 1309 1310 if (!dst) { 1311 dst = inet6_csk_route_req(sk, req); 1312 if (!dst) 1313 goto out; 1314 } 1315 1316 newsk = tcp_create_openreq_child(sk, req, skb); 1317 if (newsk == NULL) 1318 goto out_nonewsk; 1319 1320 /* 1321 * No need to charge this sock to the relevant IPv6 refcnt debug socks 1322 * count here, tcp_create_openreq_child now does this for us, see the 1323 * comment in that function for the gory details. -acme 1324 */ 1325 1326 newsk->sk_gso_type = SKB_GSO_TCPV6; 1327 __ip6_dst_store(newsk, dst, NULL, NULL); 1328 1329 newtcp6sk = (struct tcp6_sock *)newsk; 1330 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6; 1331 1332 newtp = tcp_sk(newsk); 1333 newinet = inet_sk(newsk); 1334 newnp = inet6_sk(newsk); 1335 1336 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1337 1338 newnp->daddr = treq->rmt_addr; 1339 newnp->saddr = treq->loc_addr; 1340 newnp->rcv_saddr = treq->loc_addr; 1341 newsk->sk_bound_dev_if = treq->iif; 1342 1343 /* Now IPv6 options... 1344 1345 First: no IPv4 options. 1346 */ 1347 newinet->inet_opt = NULL; 1348 newnp->ipv6_ac_list = NULL; 1349 newnp->ipv6_fl_list = NULL; 1350 1351 /* Clone RX bits */ 1352 newnp->rxopt.all = np->rxopt.all; 1353 1354 /* Clone pktoptions received with SYN */ 1355 newnp->pktoptions = NULL; 1356 if (treq->pktopts != NULL) { 1357 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC); 1358 consume_skb(treq->pktopts); 1359 treq->pktopts = NULL; 1360 if (newnp->pktoptions) 1361 skb_set_owner_r(newnp->pktoptions, newsk); 1362 } 1363 newnp->opt = NULL; 1364 newnp->mcast_oif = inet6_iif(skb); 1365 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1366 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb)); 1367 1368 /* Clone native IPv6 options from listening socket (if any) 1369 1370 Yes, keeping reference count would be much more clever, 1371 but we make one more one thing there: reattach optmem 1372 to newsk. 1373 */ 1374 if (opt) { 1375 newnp->opt = ipv6_dup_options(newsk, opt); 1376 if (opt != np->opt) 1377 sock_kfree_s(sk, opt, opt->tot_len); 1378 } 1379 1380 inet_csk(newsk)->icsk_ext_hdr_len = 0; 1381 if (newnp->opt) 1382 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen + 1383 newnp->opt->opt_flen); 1384 1385 tcp_mtup_init(newsk); 1386 tcp_sync_mss(newsk, dst_mtu(dst)); 1387 newtp->advmss = dst_metric_advmss(dst); 1388 if (tcp_sk(sk)->rx_opt.user_mss && 1389 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) 1390 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; 1391 1392 tcp_initialize_rcv_mss(newsk); 1393 if (tcp_rsk(req)->snt_synack) 1394 tcp_valid_rtt_meas(newsk, 1395 tcp_time_stamp - tcp_rsk(req)->snt_synack); 1396 newtp->total_retrans = req->retrans; 1397 1398 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 1399 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 1400 1401 #ifdef CONFIG_TCP_MD5SIG 1402 /* Copy over the MD5 key from the original socket */ 1403 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) { 1404 /* We're using one, so create a matching key 1405 * on the newsk structure. If we fail to get 1406 * memory, then we end up not copying the key 1407 * across. Shucks. 1408 */ 1409 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr, 1410 AF_INET6, key->key, key->keylen, GFP_ATOMIC); 1411 } 1412 #endif 1413 1414 if (__inet_inherit_port(sk, newsk) < 0) { 1415 sock_put(newsk); 1416 goto out; 1417 } 1418 __inet6_hash(newsk, NULL); 1419 1420 return newsk; 1421 1422 out_overflow: 1423 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 1424 out_nonewsk: 1425 if (opt && opt != np->opt) 1426 sock_kfree_s(sk, opt, opt->tot_len); 1427 dst_release(dst); 1428 out: 1429 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); 1430 return NULL; 1431 } 1432 1433 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb) 1434 { 1435 if (skb->ip_summed == CHECKSUM_COMPLETE) { 1436 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr, 1437 &ipv6_hdr(skb)->daddr, skb->csum)) { 1438 skb->ip_summed = CHECKSUM_UNNECESSARY; 1439 return 0; 1440 } 1441 } 1442 1443 skb->csum = ~csum_unfold(tcp_v6_check(skb->len, 1444 &ipv6_hdr(skb)->saddr, 1445 &ipv6_hdr(skb)->daddr, 0)); 1446 1447 if (skb->len <= 76) { 1448 return __skb_checksum_complete(skb); 1449 } 1450 return 0; 1451 } 1452 1453 /* The socket must have it's spinlock held when we get 1454 * here. 1455 * 1456 * We have a potential double-lock case here, so even when 1457 * doing backlog processing we use the BH locking scheme. 1458 * This is because we cannot sleep with the original spinlock 1459 * held. 1460 */ 1461 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 1462 { 1463 struct ipv6_pinfo *np = inet6_sk(sk); 1464 struct tcp_sock *tp; 1465 struct sk_buff *opt_skb = NULL; 1466 1467 /* Imagine: socket is IPv6. IPv4 packet arrives, 1468 goes to IPv4 receive handler and backlogged. 1469 From backlog it always goes here. Kerboom... 1470 Fortunately, tcp_rcv_established and rcv_established 1471 handle them correctly, but it is not case with 1472 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK 1473 */ 1474 1475 if (skb->protocol == htons(ETH_P_IP)) 1476 return tcp_v4_do_rcv(sk, skb); 1477 1478 #ifdef CONFIG_TCP_MD5SIG 1479 if (tcp_v6_inbound_md5_hash (sk, skb)) 1480 goto discard; 1481 #endif 1482 1483 if (sk_filter(sk, skb)) 1484 goto discard; 1485 1486 /* 1487 * socket locking is here for SMP purposes as backlog rcv 1488 * is currently called with bh processing disabled. 1489 */ 1490 1491 /* Do Stevens' IPV6_PKTOPTIONS. 1492 1493 Yes, guys, it is the only place in our code, where we 1494 may make it not affecting IPv4. 1495 The rest of code is protocol independent, 1496 and I do not like idea to uglify IPv4. 1497 1498 Actually, all the idea behind IPV6_PKTOPTIONS 1499 looks not very well thought. For now we latch 1500 options, received in the last packet, enqueued 1501 by tcp. Feel free to propose better solution. 1502 --ANK (980728) 1503 */ 1504 if (np->rxopt.all) 1505 opt_skb = skb_clone(skb, GFP_ATOMIC); 1506 1507 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ 1508 sock_rps_save_rxhash(sk, skb); 1509 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) 1510 goto reset; 1511 if (opt_skb) 1512 goto ipv6_pktoptions; 1513 return 0; 1514 } 1515 1516 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb)) 1517 goto csum_err; 1518 1519 if (sk->sk_state == TCP_LISTEN) { 1520 struct sock *nsk = tcp_v6_hnd_req(sk, skb); 1521 if (!nsk) 1522 goto discard; 1523 1524 /* 1525 * Queue it on the new socket if the new socket is active, 1526 * otherwise we just shortcircuit this and continue with 1527 * the new socket.. 1528 */ 1529 if(nsk != sk) { 1530 sock_rps_save_rxhash(nsk, skb); 1531 if (tcp_child_process(sk, nsk, skb)) 1532 goto reset; 1533 if (opt_skb) 1534 __kfree_skb(opt_skb); 1535 return 0; 1536 } 1537 } else 1538 sock_rps_save_rxhash(sk, skb); 1539 1540 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) 1541 goto reset; 1542 if (opt_skb) 1543 goto ipv6_pktoptions; 1544 return 0; 1545 1546 reset: 1547 tcp_v6_send_reset(sk, skb); 1548 discard: 1549 if (opt_skb) 1550 __kfree_skb(opt_skb); 1551 kfree_skb(skb); 1552 return 0; 1553 csum_err: 1554 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); 1555 goto discard; 1556 1557 1558 ipv6_pktoptions: 1559 /* Do you ask, what is it? 1560 1561 1. skb was enqueued by tcp. 1562 2. skb is added to tail of read queue, rather than out of order. 1563 3. socket is not in passive state. 1564 4. Finally, it really contains options, which user wants to receive. 1565 */ 1566 tp = tcp_sk(sk); 1567 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && 1568 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { 1569 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) 1570 np->mcast_oif = inet6_iif(opt_skb); 1571 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) 1572 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; 1573 if (np->rxopt.bits.rxtclass) 1574 np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb)); 1575 if (ipv6_opt_accepted(sk, opt_skb)) { 1576 skb_set_owner_r(opt_skb, sk); 1577 opt_skb = xchg(&np->pktoptions, opt_skb); 1578 } else { 1579 __kfree_skb(opt_skb); 1580 opt_skb = xchg(&np->pktoptions, NULL); 1581 } 1582 } 1583 1584 kfree_skb(opt_skb); 1585 return 0; 1586 } 1587 1588 static int tcp_v6_rcv(struct sk_buff *skb) 1589 { 1590 const struct tcphdr *th; 1591 const struct ipv6hdr *hdr; 1592 struct sock *sk; 1593 int ret; 1594 struct net *net = dev_net(skb->dev); 1595 1596 if (skb->pkt_type != PACKET_HOST) 1597 goto discard_it; 1598 1599 /* 1600 * Count it even if it's bad. 1601 */ 1602 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); 1603 1604 if (!pskb_may_pull(skb, sizeof(struct tcphdr))) 1605 goto discard_it; 1606 1607 th = tcp_hdr(skb); 1608 1609 if (th->doff < sizeof(struct tcphdr)/4) 1610 goto bad_packet; 1611 if (!pskb_may_pull(skb, th->doff*4)) 1612 goto discard_it; 1613 1614 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb)) 1615 goto bad_packet; 1616 1617 th = tcp_hdr(skb); 1618 hdr = ipv6_hdr(skb); 1619 TCP_SKB_CB(skb)->seq = ntohl(th->seq); 1620 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + 1621 skb->len - th->doff*4); 1622 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); 1623 TCP_SKB_CB(skb)->when = 0; 1624 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); 1625 TCP_SKB_CB(skb)->sacked = 0; 1626 1627 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); 1628 if (!sk) 1629 goto no_tcp_socket; 1630 1631 process: 1632 if (sk->sk_state == TCP_TIME_WAIT) 1633 goto do_time_wait; 1634 1635 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) { 1636 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); 1637 goto discard_and_relse; 1638 } 1639 1640 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 1641 goto discard_and_relse; 1642 1643 if (sk_filter(sk, skb)) 1644 goto discard_and_relse; 1645 1646 skb->dev = NULL; 1647 1648 bh_lock_sock_nested(sk); 1649 ret = 0; 1650 if (!sock_owned_by_user(sk)) { 1651 #ifdef CONFIG_NET_DMA 1652 struct tcp_sock *tp = tcp_sk(sk); 1653 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1654 tp->ucopy.dma_chan = net_dma_find_channel(); 1655 if (tp->ucopy.dma_chan) 1656 ret = tcp_v6_do_rcv(sk, skb); 1657 else 1658 #endif 1659 { 1660 if (!tcp_prequeue(sk, skb)) 1661 ret = tcp_v6_do_rcv(sk, skb); 1662 } 1663 } else if (unlikely(sk_add_backlog(sk, skb, 1664 sk->sk_rcvbuf + sk->sk_sndbuf))) { 1665 bh_unlock_sock(sk); 1666 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); 1667 goto discard_and_relse; 1668 } 1669 bh_unlock_sock(sk); 1670 1671 sock_put(sk); 1672 return ret ? -1 : 0; 1673 1674 no_tcp_socket: 1675 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 1676 goto discard_it; 1677 1678 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { 1679 bad_packet: 1680 TCP_INC_STATS_BH(net, TCP_MIB_INERRS); 1681 } else { 1682 tcp_v6_send_reset(NULL, skb); 1683 } 1684 1685 discard_it: 1686 1687 /* 1688 * Discard frame 1689 */ 1690 1691 kfree_skb(skb); 1692 return 0; 1693 1694 discard_and_relse: 1695 sock_put(sk); 1696 goto discard_it; 1697 1698 do_time_wait: 1699 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1700 inet_twsk_put(inet_twsk(sk)); 1701 goto discard_it; 1702 } 1703 1704 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { 1705 TCP_INC_STATS_BH(net, TCP_MIB_INERRS); 1706 inet_twsk_put(inet_twsk(sk)); 1707 goto discard_it; 1708 } 1709 1710 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { 1711 case TCP_TW_SYN: 1712 { 1713 struct sock *sk2; 1714 1715 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, 1716 &ipv6_hdr(skb)->daddr, 1717 ntohs(th->dest), inet6_iif(skb)); 1718 if (sk2 != NULL) { 1719 struct inet_timewait_sock *tw = inet_twsk(sk); 1720 inet_twsk_deschedule(tw, &tcp_death_row); 1721 inet_twsk_put(tw); 1722 sk = sk2; 1723 goto process; 1724 } 1725 /* Fall through to ACK */ 1726 } 1727 case TCP_TW_ACK: 1728 tcp_v6_timewait_ack(sk, skb); 1729 break; 1730 case TCP_TW_RST: 1731 goto no_tcp_socket; 1732 case TCP_TW_SUCCESS:; 1733 } 1734 goto discard_it; 1735 } 1736 1737 static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it) 1738 { 1739 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk); 1740 struct ipv6_pinfo *np = inet6_sk(sk); 1741 struct inet_peer *peer; 1742 1743 if (!rt || 1744 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) { 1745 peer = inet_getpeer_v6(&np->daddr, 1); 1746 *release_it = true; 1747 } else { 1748 if (!rt->rt6i_peer) 1749 rt6_bind_peer(rt, 1); 1750 peer = rt->rt6i_peer; 1751 *release_it = false; 1752 } 1753 1754 return peer; 1755 } 1756 1757 static void *tcp_v6_tw_get_peer(struct sock *sk) 1758 { 1759 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk); 1760 const struct inet_timewait_sock *tw = inet_twsk(sk); 1761 1762 if (tw->tw_family == AF_INET) 1763 return tcp_v4_tw_get_peer(sk); 1764 1765 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1); 1766 } 1767 1768 static struct timewait_sock_ops tcp6_timewait_sock_ops = { 1769 .twsk_obj_size = sizeof(struct tcp6_timewait_sock), 1770 .twsk_unique = tcp_twsk_unique, 1771 .twsk_destructor= tcp_twsk_destructor, 1772 .twsk_getpeer = tcp_v6_tw_get_peer, 1773 }; 1774 1775 static const struct inet_connection_sock_af_ops ipv6_specific = { 1776 .queue_xmit = inet6_csk_xmit, 1777 .send_check = tcp_v6_send_check, 1778 .rebuild_header = inet6_sk_rebuild_header, 1779 .conn_request = tcp_v6_conn_request, 1780 .syn_recv_sock = tcp_v6_syn_recv_sock, 1781 .get_peer = tcp_v6_get_peer, 1782 .net_header_len = sizeof(struct ipv6hdr), 1783 .net_frag_header_len = sizeof(struct frag_hdr), 1784 .setsockopt = ipv6_setsockopt, 1785 .getsockopt = ipv6_getsockopt, 1786 .addr2sockaddr = inet6_csk_addr2sockaddr, 1787 .sockaddr_len = sizeof(struct sockaddr_in6), 1788 .bind_conflict = inet6_csk_bind_conflict, 1789 #ifdef CONFIG_COMPAT 1790 .compat_setsockopt = compat_ipv6_setsockopt, 1791 .compat_getsockopt = compat_ipv6_getsockopt, 1792 #endif 1793 }; 1794 1795 #ifdef CONFIG_TCP_MD5SIG 1796 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { 1797 .md5_lookup = tcp_v6_md5_lookup, 1798 .calc_md5_hash = tcp_v6_md5_hash_skb, 1799 .md5_parse = tcp_v6_parse_md5_keys, 1800 }; 1801 #endif 1802 1803 /* 1804 * TCP over IPv4 via INET6 API 1805 */ 1806 1807 static const struct inet_connection_sock_af_ops ipv6_mapped = { 1808 .queue_xmit = ip_queue_xmit, 1809 .send_check = tcp_v4_send_check, 1810 .rebuild_header = inet_sk_rebuild_header, 1811 .conn_request = tcp_v6_conn_request, 1812 .syn_recv_sock = tcp_v6_syn_recv_sock, 1813 .get_peer = tcp_v4_get_peer, 1814 .net_header_len = sizeof(struct iphdr), 1815 .setsockopt = ipv6_setsockopt, 1816 .getsockopt = ipv6_getsockopt, 1817 .addr2sockaddr = inet6_csk_addr2sockaddr, 1818 .sockaddr_len = sizeof(struct sockaddr_in6), 1819 .bind_conflict = inet6_csk_bind_conflict, 1820 #ifdef CONFIG_COMPAT 1821 .compat_setsockopt = compat_ipv6_setsockopt, 1822 .compat_getsockopt = compat_ipv6_getsockopt, 1823 #endif 1824 }; 1825 1826 #ifdef CONFIG_TCP_MD5SIG 1827 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { 1828 .md5_lookup = tcp_v4_md5_lookup, 1829 .calc_md5_hash = tcp_v4_md5_hash_skb, 1830 .md5_parse = tcp_v6_parse_md5_keys, 1831 }; 1832 #endif 1833 1834 /* NOTE: A lot of things set to zero explicitly by call to 1835 * sk_alloc() so need not be done here. 1836 */ 1837 static int tcp_v6_init_sock(struct sock *sk) 1838 { 1839 struct inet_connection_sock *icsk = inet_csk(sk); 1840 1841 tcp_init_sock(sk); 1842 1843 icsk->icsk_af_ops = &ipv6_specific; 1844 1845 #ifdef CONFIG_TCP_MD5SIG 1846 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; 1847 #endif 1848 1849 return 0; 1850 } 1851 1852 static void tcp_v6_destroy_sock(struct sock *sk) 1853 { 1854 tcp_v4_destroy_sock(sk); 1855 inet6_destroy_sock(sk); 1856 } 1857 1858 #ifdef CONFIG_PROC_FS 1859 /* Proc filesystem TCPv6 sock list dumping. */ 1860 static void get_openreq6(struct seq_file *seq, 1861 const struct sock *sk, struct request_sock *req, int i, int uid) 1862 { 1863 int ttd = req->expires - jiffies; 1864 const struct in6_addr *src = &inet6_rsk(req)->loc_addr; 1865 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr; 1866 1867 if (ttd < 0) 1868 ttd = 0; 1869 1870 seq_printf(seq, 1871 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 1872 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 1873 i, 1874 src->s6_addr32[0], src->s6_addr32[1], 1875 src->s6_addr32[2], src->s6_addr32[3], 1876 ntohs(inet_rsk(req)->loc_port), 1877 dest->s6_addr32[0], dest->s6_addr32[1], 1878 dest->s6_addr32[2], dest->s6_addr32[3], 1879 ntohs(inet_rsk(req)->rmt_port), 1880 TCP_SYN_RECV, 1881 0,0, /* could print option size, but that is af dependent. */ 1882 1, /* timers active (only the expire timer) */ 1883 jiffies_to_clock_t(ttd), 1884 req->retrans, 1885 uid, 1886 0, /* non standard timer */ 1887 0, /* open_requests have no inode */ 1888 0, req); 1889 } 1890 1891 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 1892 { 1893 const struct in6_addr *dest, *src; 1894 __u16 destp, srcp; 1895 int timer_active; 1896 unsigned long timer_expires; 1897 const struct inet_sock *inet = inet_sk(sp); 1898 const struct tcp_sock *tp = tcp_sk(sp); 1899 const struct inet_connection_sock *icsk = inet_csk(sp); 1900 const struct ipv6_pinfo *np = inet6_sk(sp); 1901 1902 dest = &np->daddr; 1903 src = &np->rcv_saddr; 1904 destp = ntohs(inet->inet_dport); 1905 srcp = ntohs(inet->inet_sport); 1906 1907 if (icsk->icsk_pending == ICSK_TIME_RETRANS) { 1908 timer_active = 1; 1909 timer_expires = icsk->icsk_timeout; 1910 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 1911 timer_active = 4; 1912 timer_expires = icsk->icsk_timeout; 1913 } else if (timer_pending(&sp->sk_timer)) { 1914 timer_active = 2; 1915 timer_expires = sp->sk_timer.expires; 1916 } else { 1917 timer_active = 0; 1918 timer_expires = jiffies; 1919 } 1920 1921 seq_printf(seq, 1922 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 1923 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n", 1924 i, 1925 src->s6_addr32[0], src->s6_addr32[1], 1926 src->s6_addr32[2], src->s6_addr32[3], srcp, 1927 dest->s6_addr32[0], dest->s6_addr32[1], 1928 dest->s6_addr32[2], dest->s6_addr32[3], destp, 1929 sp->sk_state, 1930 tp->write_seq-tp->snd_una, 1931 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq), 1932 timer_active, 1933 jiffies_to_clock_t(timer_expires - jiffies), 1934 icsk->icsk_retransmits, 1935 sock_i_uid(sp), 1936 icsk->icsk_probes_out, 1937 sock_i_ino(sp), 1938 atomic_read(&sp->sk_refcnt), sp, 1939 jiffies_to_clock_t(icsk->icsk_rto), 1940 jiffies_to_clock_t(icsk->icsk_ack.ato), 1941 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong, 1942 tp->snd_cwnd, 1943 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh 1944 ); 1945 } 1946 1947 static void get_timewait6_sock(struct seq_file *seq, 1948 struct inet_timewait_sock *tw, int i) 1949 { 1950 const struct in6_addr *dest, *src; 1951 __u16 destp, srcp; 1952 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw); 1953 int ttd = tw->tw_ttd - jiffies; 1954 1955 if (ttd < 0) 1956 ttd = 0; 1957 1958 dest = &tw6->tw_v6_daddr; 1959 src = &tw6->tw_v6_rcv_saddr; 1960 destp = ntohs(tw->tw_dport); 1961 srcp = ntohs(tw->tw_sport); 1962 1963 seq_printf(seq, 1964 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 1965 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 1966 i, 1967 src->s6_addr32[0], src->s6_addr32[1], 1968 src->s6_addr32[2], src->s6_addr32[3], srcp, 1969 dest->s6_addr32[0], dest->s6_addr32[1], 1970 dest->s6_addr32[2], dest->s6_addr32[3], destp, 1971 tw->tw_substate, 0, 0, 1972 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, 1973 atomic_read(&tw->tw_refcnt), tw); 1974 } 1975 1976 static int tcp6_seq_show(struct seq_file *seq, void *v) 1977 { 1978 struct tcp_iter_state *st; 1979 1980 if (v == SEQ_START_TOKEN) { 1981 seq_puts(seq, 1982 " sl " 1983 "local_address " 1984 "remote_address " 1985 "st tx_queue rx_queue tr tm->when retrnsmt" 1986 " uid timeout inode\n"); 1987 goto out; 1988 } 1989 st = seq->private; 1990 1991 switch (st->state) { 1992 case TCP_SEQ_STATE_LISTENING: 1993 case TCP_SEQ_STATE_ESTABLISHED: 1994 get_tcp6_sock(seq, v, st->num); 1995 break; 1996 case TCP_SEQ_STATE_OPENREQ: 1997 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid); 1998 break; 1999 case TCP_SEQ_STATE_TIME_WAIT: 2000 get_timewait6_sock(seq, v, st->num); 2001 break; 2002 } 2003 out: 2004 return 0; 2005 } 2006 2007 static const struct file_operations tcp6_afinfo_seq_fops = { 2008 .owner = THIS_MODULE, 2009 .open = tcp_seq_open, 2010 .read = seq_read, 2011 .llseek = seq_lseek, 2012 .release = seq_release_net 2013 }; 2014 2015 static struct tcp_seq_afinfo tcp6_seq_afinfo = { 2016 .name = "tcp6", 2017 .family = AF_INET6, 2018 .seq_fops = &tcp6_afinfo_seq_fops, 2019 .seq_ops = { 2020 .show = tcp6_seq_show, 2021 }, 2022 }; 2023 2024 int __net_init tcp6_proc_init(struct net *net) 2025 { 2026 return tcp_proc_register(net, &tcp6_seq_afinfo); 2027 } 2028 2029 void tcp6_proc_exit(struct net *net) 2030 { 2031 tcp_proc_unregister(net, &tcp6_seq_afinfo); 2032 } 2033 #endif 2034 2035 struct proto tcpv6_prot = { 2036 .name = "TCPv6", 2037 .owner = THIS_MODULE, 2038 .close = tcp_close, 2039 .connect = tcp_v6_connect, 2040 .disconnect = tcp_disconnect, 2041 .accept = inet_csk_accept, 2042 .ioctl = tcp_ioctl, 2043 .init = tcp_v6_init_sock, 2044 .destroy = tcp_v6_destroy_sock, 2045 .shutdown = tcp_shutdown, 2046 .setsockopt = tcp_setsockopt, 2047 .getsockopt = tcp_getsockopt, 2048 .recvmsg = tcp_recvmsg, 2049 .sendmsg = tcp_sendmsg, 2050 .sendpage = tcp_sendpage, 2051 .backlog_rcv = tcp_v6_do_rcv, 2052 .hash = tcp_v6_hash, 2053 .unhash = inet_unhash, 2054 .get_port = inet_csk_get_port, 2055 .enter_memory_pressure = tcp_enter_memory_pressure, 2056 .sockets_allocated = &tcp_sockets_allocated, 2057 .memory_allocated = &tcp_memory_allocated, 2058 .memory_pressure = &tcp_memory_pressure, 2059 .orphan_count = &tcp_orphan_count, 2060 .sysctl_wmem = sysctl_tcp_wmem, 2061 .sysctl_rmem = sysctl_tcp_rmem, 2062 .max_header = MAX_TCP_HEADER, 2063 .obj_size = sizeof(struct tcp6_sock), 2064 .slab_flags = SLAB_DESTROY_BY_RCU, 2065 .twsk_prot = &tcp6_timewait_sock_ops, 2066 .rsk_prot = &tcp6_request_sock_ops, 2067 .h.hashinfo = &tcp_hashinfo, 2068 .no_autobind = true, 2069 #ifdef CONFIG_COMPAT 2070 .compat_setsockopt = compat_tcp_setsockopt, 2071 .compat_getsockopt = compat_tcp_getsockopt, 2072 #endif 2073 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM 2074 .proto_cgroup = tcp_proto_cgroup, 2075 #endif 2076 }; 2077 2078 static const struct inet6_protocol tcpv6_protocol = { 2079 .handler = tcp_v6_rcv, 2080 .err_handler = tcp_v6_err, 2081 .gso_send_check = tcp_v6_gso_send_check, 2082 .gso_segment = tcp_tso_segment, 2083 .gro_receive = tcp6_gro_receive, 2084 .gro_complete = tcp6_gro_complete, 2085 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 2086 }; 2087 2088 static struct inet_protosw tcpv6_protosw = { 2089 .type = SOCK_STREAM, 2090 .protocol = IPPROTO_TCP, 2091 .prot = &tcpv6_prot, 2092 .ops = &inet6_stream_ops, 2093 .no_check = 0, 2094 .flags = INET_PROTOSW_PERMANENT | 2095 INET_PROTOSW_ICSK, 2096 }; 2097 2098 static int __net_init tcpv6_net_init(struct net *net) 2099 { 2100 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, 2101 SOCK_RAW, IPPROTO_TCP, net); 2102 } 2103 2104 static void __net_exit tcpv6_net_exit(struct net *net) 2105 { 2106 inet_ctl_sock_destroy(net->ipv6.tcp_sk); 2107 } 2108 2109 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) 2110 { 2111 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6); 2112 } 2113 2114 static struct pernet_operations tcpv6_net_ops = { 2115 .init = tcpv6_net_init, 2116 .exit = tcpv6_net_exit, 2117 .exit_batch = tcpv6_net_exit_batch, 2118 }; 2119 2120 int __init tcpv6_init(void) 2121 { 2122 int ret; 2123 2124 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); 2125 if (ret) 2126 goto out; 2127 2128 /* register inet6 protocol */ 2129 ret = inet6_register_protosw(&tcpv6_protosw); 2130 if (ret) 2131 goto out_tcpv6_protocol; 2132 2133 ret = register_pernet_subsys(&tcpv6_net_ops); 2134 if (ret) 2135 goto out_tcpv6_protosw; 2136 out: 2137 return ret; 2138 2139 out_tcpv6_protocol: 2140 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2141 out_tcpv6_protosw: 2142 inet6_unregister_protosw(&tcpv6_protosw); 2143 goto out; 2144 } 2145 2146 void tcpv6_exit(void) 2147 { 2148 unregister_pernet_subsys(&tcpv6_net_ops); 2149 inet6_unregister_protosw(&tcpv6_protosw); 2150 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2151 } 2152