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 { 481 struct inet6_request_sock *treq = inet6_rsk(req); 482 struct ipv6_pinfo *np = inet6_sk(sk); 483 struct sk_buff * skb; 484 struct ipv6_txoptions *opt = NULL; 485 struct in6_addr * final_p, final; 486 struct flowi6 fl6; 487 struct dst_entry *dst; 488 int err; 489 490 memset(&fl6, 0, sizeof(fl6)); 491 fl6.flowi6_proto = IPPROTO_TCP; 492 fl6.daddr = treq->rmt_addr; 493 fl6.saddr = treq->loc_addr; 494 fl6.flowlabel = 0; 495 fl6.flowi6_oif = treq->iif; 496 fl6.flowi6_mark = sk->sk_mark; 497 fl6.fl6_dport = inet_rsk(req)->rmt_port; 498 fl6.fl6_sport = inet_rsk(req)->loc_port; 499 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 500 501 opt = np->opt; 502 final_p = fl6_update_dst(&fl6, opt, &final); 503 504 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false); 505 if (IS_ERR(dst)) { 506 err = PTR_ERR(dst); 507 dst = NULL; 508 goto done; 509 } 510 skb = tcp_make_synack(sk, dst, req, rvp); 511 err = -ENOMEM; 512 if (skb) { 513 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr); 514 515 fl6.daddr = treq->rmt_addr; 516 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass); 517 err = net_xmit_eval(err); 518 } 519 520 done: 521 if (opt && opt != np->opt) 522 sock_kfree_s(sk, opt, opt->tot_len); 523 dst_release(dst); 524 return err; 525 } 526 527 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req, 528 struct request_values *rvp) 529 { 530 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); 531 return tcp_v6_send_synack(sk, req, rvp); 532 } 533 534 static void tcp_v6_reqsk_destructor(struct request_sock *req) 535 { 536 kfree_skb(inet6_rsk(req)->pktopts); 537 } 538 539 #ifdef CONFIG_TCP_MD5SIG 540 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk, 541 const struct in6_addr *addr) 542 { 543 struct tcp_sock *tp = tcp_sk(sk); 544 int i; 545 546 BUG_ON(tp == NULL); 547 548 if (!tp->md5sig_info || !tp->md5sig_info->entries6) 549 return NULL; 550 551 for (i = 0; i < tp->md5sig_info->entries6; i++) { 552 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr)) 553 return &tp->md5sig_info->keys6[i].base; 554 } 555 return NULL; 556 } 557 558 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk, 559 struct sock *addr_sk) 560 { 561 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr); 562 } 563 564 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk, 565 struct request_sock *req) 566 { 567 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr); 568 } 569 570 static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer, 571 char *newkey, u8 newkeylen) 572 { 573 /* Add key to the list */ 574 struct tcp_md5sig_key *key; 575 struct tcp_sock *tp = tcp_sk(sk); 576 struct tcp6_md5sig_key *keys; 577 578 key = tcp_v6_md5_do_lookup(sk, peer); 579 if (key) { 580 /* modify existing entry - just update that one */ 581 kfree(key->key); 582 key->key = newkey; 583 key->keylen = newkeylen; 584 } else { 585 /* reallocate new list if current one is full. */ 586 if (!tp->md5sig_info) { 587 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC); 588 if (!tp->md5sig_info) { 589 kfree(newkey); 590 return -ENOMEM; 591 } 592 sk_nocaps_add(sk, NETIF_F_GSO_MASK); 593 } 594 if (tp->md5sig_info->entries6 == 0 && 595 tcp_alloc_md5sig_pool(sk) == NULL) { 596 kfree(newkey); 597 return -ENOMEM; 598 } 599 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) { 600 keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) * 601 (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC); 602 603 if (!keys) { 604 kfree(newkey); 605 if (tp->md5sig_info->entries6 == 0) 606 tcp_free_md5sig_pool(); 607 return -ENOMEM; 608 } 609 610 if (tp->md5sig_info->entries6) 611 memmove(keys, tp->md5sig_info->keys6, 612 (sizeof (tp->md5sig_info->keys6[0]) * 613 tp->md5sig_info->entries6)); 614 615 kfree(tp->md5sig_info->keys6); 616 tp->md5sig_info->keys6 = keys; 617 tp->md5sig_info->alloced6++; 618 } 619 620 tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr = *peer; 621 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey; 622 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen; 623 624 tp->md5sig_info->entries6++; 625 } 626 return 0; 627 } 628 629 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk, 630 u8 *newkey, __u8 newkeylen) 631 { 632 return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr, 633 newkey, newkeylen); 634 } 635 636 static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer) 637 { 638 struct tcp_sock *tp = tcp_sk(sk); 639 int i; 640 641 for (i = 0; i < tp->md5sig_info->entries6; i++) { 642 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) { 643 /* Free the key */ 644 kfree(tp->md5sig_info->keys6[i].base.key); 645 tp->md5sig_info->entries6--; 646 647 if (tp->md5sig_info->entries6 == 0) { 648 kfree(tp->md5sig_info->keys6); 649 tp->md5sig_info->keys6 = NULL; 650 tp->md5sig_info->alloced6 = 0; 651 tcp_free_md5sig_pool(); 652 } else { 653 /* shrink the database */ 654 if (tp->md5sig_info->entries6 != i) 655 memmove(&tp->md5sig_info->keys6[i], 656 &tp->md5sig_info->keys6[i+1], 657 (tp->md5sig_info->entries6 - i) 658 * sizeof (tp->md5sig_info->keys6[0])); 659 } 660 return 0; 661 } 662 } 663 return -ENOENT; 664 } 665 666 static void tcp_v6_clear_md5_list (struct sock *sk) 667 { 668 struct tcp_sock *tp = tcp_sk(sk); 669 int i; 670 671 if (tp->md5sig_info->entries6) { 672 for (i = 0; i < tp->md5sig_info->entries6; i++) 673 kfree(tp->md5sig_info->keys6[i].base.key); 674 tp->md5sig_info->entries6 = 0; 675 tcp_free_md5sig_pool(); 676 } 677 678 kfree(tp->md5sig_info->keys6); 679 tp->md5sig_info->keys6 = NULL; 680 tp->md5sig_info->alloced6 = 0; 681 682 if (tp->md5sig_info->entries4) { 683 for (i = 0; i < tp->md5sig_info->entries4; i++) 684 kfree(tp->md5sig_info->keys4[i].base.key); 685 tp->md5sig_info->entries4 = 0; 686 tcp_free_md5sig_pool(); 687 } 688 689 kfree(tp->md5sig_info->keys4); 690 tp->md5sig_info->keys4 = NULL; 691 tp->md5sig_info->alloced4 = 0; 692 } 693 694 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval, 695 int optlen) 696 { 697 struct tcp_md5sig cmd; 698 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; 699 u8 *newkey; 700 701 if (optlen < sizeof(cmd)) 702 return -EINVAL; 703 704 if (copy_from_user(&cmd, optval, sizeof(cmd))) 705 return -EFAULT; 706 707 if (sin6->sin6_family != AF_INET6) 708 return -EINVAL; 709 710 if (!cmd.tcpm_keylen) { 711 if (!tcp_sk(sk)->md5sig_info) 712 return -ENOENT; 713 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 714 return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]); 715 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr); 716 } 717 718 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) 719 return -EINVAL; 720 721 if (!tcp_sk(sk)->md5sig_info) { 722 struct tcp_sock *tp = tcp_sk(sk); 723 struct tcp_md5sig_info *p; 724 725 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL); 726 if (!p) 727 return -ENOMEM; 728 729 tp->md5sig_info = p; 730 sk_nocaps_add(sk, NETIF_F_GSO_MASK); 731 } 732 733 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); 734 if (!newkey) 735 return -ENOMEM; 736 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { 737 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3], 738 newkey, cmd.tcpm_keylen); 739 } 740 return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen); 741 } 742 743 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, 744 const struct in6_addr *daddr, 745 const struct in6_addr *saddr, int nbytes) 746 { 747 struct tcp6_pseudohdr *bp; 748 struct scatterlist sg; 749 750 bp = &hp->md5_blk.ip6; 751 /* 1. TCP pseudo-header (RFC2460) */ 752 bp->saddr = *saddr; 753 bp->daddr = *daddr; 754 bp->protocol = cpu_to_be32(IPPROTO_TCP); 755 bp->len = cpu_to_be32(nbytes); 756 757 sg_init_one(&sg, bp, sizeof(*bp)); 758 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); 759 } 760 761 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key, 762 const struct in6_addr *daddr, struct in6_addr *saddr, 763 const struct tcphdr *th) 764 { 765 struct tcp_md5sig_pool *hp; 766 struct hash_desc *desc; 767 768 hp = tcp_get_md5sig_pool(); 769 if (!hp) 770 goto clear_hash_noput; 771 desc = &hp->md5_desc; 772 773 if (crypto_hash_init(desc)) 774 goto clear_hash; 775 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) 776 goto clear_hash; 777 if (tcp_md5_hash_header(hp, th)) 778 goto clear_hash; 779 if (tcp_md5_hash_key(hp, key)) 780 goto clear_hash; 781 if (crypto_hash_final(desc, md5_hash)) 782 goto clear_hash; 783 784 tcp_put_md5sig_pool(); 785 return 0; 786 787 clear_hash: 788 tcp_put_md5sig_pool(); 789 clear_hash_noput: 790 memset(md5_hash, 0, 16); 791 return 1; 792 } 793 794 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, 795 const struct sock *sk, 796 const struct request_sock *req, 797 const struct sk_buff *skb) 798 { 799 const struct in6_addr *saddr, *daddr; 800 struct tcp_md5sig_pool *hp; 801 struct hash_desc *desc; 802 const struct tcphdr *th = tcp_hdr(skb); 803 804 if (sk) { 805 saddr = &inet6_sk(sk)->saddr; 806 daddr = &inet6_sk(sk)->daddr; 807 } else if (req) { 808 saddr = &inet6_rsk(req)->loc_addr; 809 daddr = &inet6_rsk(req)->rmt_addr; 810 } else { 811 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 812 saddr = &ip6h->saddr; 813 daddr = &ip6h->daddr; 814 } 815 816 hp = tcp_get_md5sig_pool(); 817 if (!hp) 818 goto clear_hash_noput; 819 desc = &hp->md5_desc; 820 821 if (crypto_hash_init(desc)) 822 goto clear_hash; 823 824 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) 825 goto clear_hash; 826 if (tcp_md5_hash_header(hp, th)) 827 goto clear_hash; 828 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) 829 goto clear_hash; 830 if (tcp_md5_hash_key(hp, key)) 831 goto clear_hash; 832 if (crypto_hash_final(desc, md5_hash)) 833 goto clear_hash; 834 835 tcp_put_md5sig_pool(); 836 return 0; 837 838 clear_hash: 839 tcp_put_md5sig_pool(); 840 clear_hash_noput: 841 memset(md5_hash, 0, 16); 842 return 1; 843 } 844 845 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb) 846 { 847 const __u8 *hash_location = NULL; 848 struct tcp_md5sig_key *hash_expected; 849 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 850 const struct tcphdr *th = tcp_hdr(skb); 851 int genhash; 852 u8 newhash[16]; 853 854 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr); 855 hash_location = tcp_parse_md5sig_option(th); 856 857 /* We've parsed the options - do we have a hash? */ 858 if (!hash_expected && !hash_location) 859 return 0; 860 861 if (hash_expected && !hash_location) { 862 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); 863 return 1; 864 } 865 866 if (!hash_expected && hash_location) { 867 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); 868 return 1; 869 } 870 871 /* check the signature */ 872 genhash = tcp_v6_md5_hash_skb(newhash, 873 hash_expected, 874 NULL, NULL, skb); 875 876 if (genhash || memcmp(hash_location, newhash, 16) != 0) { 877 if (net_ratelimit()) { 878 printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n", 879 genhash ? "failed" : "mismatch", 880 &ip6h->saddr, ntohs(th->source), 881 &ip6h->daddr, ntohs(th->dest)); 882 } 883 return 1; 884 } 885 return 0; 886 } 887 #endif 888 889 struct request_sock_ops tcp6_request_sock_ops __read_mostly = { 890 .family = AF_INET6, 891 .obj_size = sizeof(struct tcp6_request_sock), 892 .rtx_syn_ack = tcp_v6_rtx_synack, 893 .send_ack = tcp_v6_reqsk_send_ack, 894 .destructor = tcp_v6_reqsk_destructor, 895 .send_reset = tcp_v6_send_reset, 896 .syn_ack_timeout = tcp_syn_ack_timeout, 897 }; 898 899 #ifdef CONFIG_TCP_MD5SIG 900 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { 901 .md5_lookup = tcp_v6_reqsk_md5_lookup, 902 .calc_md5_hash = tcp_v6_md5_hash_skb, 903 }; 904 #endif 905 906 static void __tcp_v6_send_check(struct sk_buff *skb, 907 const struct in6_addr *saddr, const struct in6_addr *daddr) 908 { 909 struct tcphdr *th = tcp_hdr(skb); 910 911 if (skb->ip_summed == CHECKSUM_PARTIAL) { 912 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0); 913 skb->csum_start = skb_transport_header(skb) - skb->head; 914 skb->csum_offset = offsetof(struct tcphdr, check); 915 } else { 916 th->check = tcp_v6_check(skb->len, saddr, daddr, 917 csum_partial(th, th->doff << 2, 918 skb->csum)); 919 } 920 } 921 922 static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) 923 { 924 struct ipv6_pinfo *np = inet6_sk(sk); 925 926 __tcp_v6_send_check(skb, &np->saddr, &np->daddr); 927 } 928 929 static int tcp_v6_gso_send_check(struct sk_buff *skb) 930 { 931 const struct ipv6hdr *ipv6h; 932 struct tcphdr *th; 933 934 if (!pskb_may_pull(skb, sizeof(*th))) 935 return -EINVAL; 936 937 ipv6h = ipv6_hdr(skb); 938 th = tcp_hdr(skb); 939 940 th->check = 0; 941 skb->ip_summed = CHECKSUM_PARTIAL; 942 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr); 943 return 0; 944 } 945 946 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head, 947 struct sk_buff *skb) 948 { 949 const struct ipv6hdr *iph = skb_gro_network_header(skb); 950 951 switch (skb->ip_summed) { 952 case CHECKSUM_COMPLETE: 953 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr, 954 skb->csum)) { 955 skb->ip_summed = CHECKSUM_UNNECESSARY; 956 break; 957 } 958 959 /* fall through */ 960 case CHECKSUM_NONE: 961 NAPI_GRO_CB(skb)->flush = 1; 962 return NULL; 963 } 964 965 return tcp_gro_receive(head, skb); 966 } 967 968 static int tcp6_gro_complete(struct sk_buff *skb) 969 { 970 const struct ipv6hdr *iph = ipv6_hdr(skb); 971 struct tcphdr *th = tcp_hdr(skb); 972 973 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb), 974 &iph->saddr, &iph->daddr, 0); 975 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; 976 977 return tcp_gro_complete(skb); 978 } 979 980 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, 981 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass) 982 { 983 const struct tcphdr *th = tcp_hdr(skb); 984 struct tcphdr *t1; 985 struct sk_buff *buff; 986 struct flowi6 fl6; 987 struct net *net = dev_net(skb_dst(skb)->dev); 988 struct sock *ctl_sk = net->ipv6.tcp_sk; 989 unsigned int tot_len = sizeof(struct tcphdr); 990 struct dst_entry *dst; 991 __be32 *topt; 992 993 if (ts) 994 tot_len += TCPOLEN_TSTAMP_ALIGNED; 995 #ifdef CONFIG_TCP_MD5SIG 996 if (key) 997 tot_len += TCPOLEN_MD5SIG_ALIGNED; 998 #endif 999 1000 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len, 1001 GFP_ATOMIC); 1002 if (buff == NULL) 1003 return; 1004 1005 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len); 1006 1007 t1 = (struct tcphdr *) skb_push(buff, tot_len); 1008 skb_reset_transport_header(buff); 1009 1010 /* Swap the send and the receive. */ 1011 memset(t1, 0, sizeof(*t1)); 1012 t1->dest = th->source; 1013 t1->source = th->dest; 1014 t1->doff = tot_len / 4; 1015 t1->seq = htonl(seq); 1016 t1->ack_seq = htonl(ack); 1017 t1->ack = !rst || !th->ack; 1018 t1->rst = rst; 1019 t1->window = htons(win); 1020 1021 topt = (__be32 *)(t1 + 1); 1022 1023 if (ts) { 1024 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 1025 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); 1026 *topt++ = htonl(tcp_time_stamp); 1027 *topt++ = htonl(ts); 1028 } 1029 1030 #ifdef CONFIG_TCP_MD5SIG 1031 if (key) { 1032 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 1033 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); 1034 tcp_v6_md5_hash_hdr((__u8 *)topt, key, 1035 &ipv6_hdr(skb)->saddr, 1036 &ipv6_hdr(skb)->daddr, t1); 1037 } 1038 #endif 1039 1040 memset(&fl6, 0, sizeof(fl6)); 1041 fl6.daddr = ipv6_hdr(skb)->saddr; 1042 fl6.saddr = ipv6_hdr(skb)->daddr; 1043 1044 buff->ip_summed = CHECKSUM_PARTIAL; 1045 buff->csum = 0; 1046 1047 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); 1048 1049 fl6.flowi6_proto = IPPROTO_TCP; 1050 fl6.flowi6_oif = inet6_iif(skb); 1051 fl6.fl6_dport = t1->dest; 1052 fl6.fl6_sport = t1->source; 1053 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); 1054 1055 /* Pass a socket to ip6_dst_lookup either it is for RST 1056 * Underlying function will use this to retrieve the network 1057 * namespace 1058 */ 1059 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false); 1060 if (!IS_ERR(dst)) { 1061 skb_dst_set(buff, dst); 1062 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass); 1063 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); 1064 if (rst) 1065 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); 1066 return; 1067 } 1068 1069 kfree_skb(buff); 1070 } 1071 1072 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb) 1073 { 1074 const struct tcphdr *th = tcp_hdr(skb); 1075 u32 seq = 0, ack_seq = 0; 1076 struct tcp_md5sig_key *key = NULL; 1077 1078 if (th->rst) 1079 return; 1080 1081 if (!ipv6_unicast_destination(skb)) 1082 return; 1083 1084 #ifdef CONFIG_TCP_MD5SIG 1085 if (sk) 1086 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr); 1087 #endif 1088 1089 if (th->ack) 1090 seq = ntohl(th->ack_seq); 1091 else 1092 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - 1093 (th->doff << 2); 1094 1095 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0); 1096 } 1097 1098 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts, 1099 struct tcp_md5sig_key *key, u8 tclass) 1100 { 1101 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass); 1102 } 1103 1104 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) 1105 { 1106 struct inet_timewait_sock *tw = inet_twsk(sk); 1107 struct tcp_timewait_sock *tcptw = tcp_twsk(sk); 1108 1109 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, 1110 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, 1111 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw), 1112 tw->tw_tclass); 1113 1114 inet_twsk_put(tw); 1115 } 1116 1117 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, 1118 struct request_sock *req) 1119 { 1120 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent, 1121 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0); 1122 } 1123 1124 1125 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb) 1126 { 1127 struct request_sock *req, **prev; 1128 const struct tcphdr *th = tcp_hdr(skb); 1129 struct sock *nsk; 1130 1131 /* Find possible connection requests. */ 1132 req = inet6_csk_search_req(sk, &prev, th->source, 1133 &ipv6_hdr(skb)->saddr, 1134 &ipv6_hdr(skb)->daddr, inet6_iif(skb)); 1135 if (req) 1136 return tcp_check_req(sk, skb, req, prev); 1137 1138 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo, 1139 &ipv6_hdr(skb)->saddr, th->source, 1140 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb)); 1141 1142 if (nsk) { 1143 if (nsk->sk_state != TCP_TIME_WAIT) { 1144 bh_lock_sock(nsk); 1145 return nsk; 1146 } 1147 inet_twsk_put(inet_twsk(nsk)); 1148 return NULL; 1149 } 1150 1151 #ifdef CONFIG_SYN_COOKIES 1152 if (!th->syn) 1153 sk = cookie_v6_check(sk, skb); 1154 #endif 1155 return sk; 1156 } 1157 1158 /* FIXME: this is substantially similar to the ipv4 code. 1159 * Can some kind of merge be done? -- erics 1160 */ 1161 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 1162 { 1163 struct tcp_extend_values tmp_ext; 1164 struct tcp_options_received tmp_opt; 1165 const u8 *hash_location; 1166 struct request_sock *req; 1167 struct inet6_request_sock *treq; 1168 struct ipv6_pinfo *np = inet6_sk(sk); 1169 struct tcp_sock *tp = tcp_sk(sk); 1170 __u32 isn = TCP_SKB_CB(skb)->when; 1171 struct dst_entry *dst = NULL; 1172 int want_cookie = 0; 1173 1174 if (skb->protocol == htons(ETH_P_IP)) 1175 return tcp_v4_conn_request(sk, skb); 1176 1177 if (!ipv6_unicast_destination(skb)) 1178 goto drop; 1179 1180 if (inet_csk_reqsk_queue_is_full(sk) && !isn) { 1181 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6"); 1182 if (!want_cookie) 1183 goto drop; 1184 } 1185 1186 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) 1187 goto drop; 1188 1189 req = inet6_reqsk_alloc(&tcp6_request_sock_ops); 1190 if (req == NULL) 1191 goto drop; 1192 1193 #ifdef CONFIG_TCP_MD5SIG 1194 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops; 1195 #endif 1196 1197 tcp_clear_options(&tmp_opt); 1198 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); 1199 tmp_opt.user_mss = tp->rx_opt.user_mss; 1200 tcp_parse_options(skb, &tmp_opt, &hash_location, 0); 1201 1202 if (tmp_opt.cookie_plus > 0 && 1203 tmp_opt.saw_tstamp && 1204 !tp->rx_opt.cookie_out_never && 1205 (sysctl_tcp_cookie_size > 0 || 1206 (tp->cookie_values != NULL && 1207 tp->cookie_values->cookie_desired > 0))) { 1208 u8 *c; 1209 u32 *d; 1210 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS]; 1211 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE; 1212 1213 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0) 1214 goto drop_and_free; 1215 1216 /* Secret recipe starts with IP addresses */ 1217 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0]; 1218 *mess++ ^= *d++; 1219 *mess++ ^= *d++; 1220 *mess++ ^= *d++; 1221 *mess++ ^= *d++; 1222 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0]; 1223 *mess++ ^= *d++; 1224 *mess++ ^= *d++; 1225 *mess++ ^= *d++; 1226 *mess++ ^= *d++; 1227 1228 /* plus variable length Initiator Cookie */ 1229 c = (u8 *)mess; 1230 while (l-- > 0) 1231 *c++ ^= *hash_location++; 1232 1233 want_cookie = 0; /* not our kind of cookie */ 1234 tmp_ext.cookie_out_never = 0; /* false */ 1235 tmp_ext.cookie_plus = tmp_opt.cookie_plus; 1236 } else if (!tp->rx_opt.cookie_in_always) { 1237 /* redundant indications, but ensure initialization. */ 1238 tmp_ext.cookie_out_never = 1; /* true */ 1239 tmp_ext.cookie_plus = 0; 1240 } else { 1241 goto drop_and_free; 1242 } 1243 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; 1244 1245 if (want_cookie && !tmp_opt.saw_tstamp) 1246 tcp_clear_options(&tmp_opt); 1247 1248 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; 1249 tcp_openreq_init(req, &tmp_opt, skb); 1250 1251 treq = inet6_rsk(req); 1252 treq->rmt_addr = ipv6_hdr(skb)->saddr; 1253 treq->loc_addr = ipv6_hdr(skb)->daddr; 1254 if (!want_cookie || tmp_opt.tstamp_ok) 1255 TCP_ECN_create_request(req, tcp_hdr(skb)); 1256 1257 treq->iif = sk->sk_bound_dev_if; 1258 1259 /* So that link locals have meaning */ 1260 if (!sk->sk_bound_dev_if && 1261 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL) 1262 treq->iif = inet6_iif(skb); 1263 1264 if (!isn) { 1265 struct inet_peer *peer = NULL; 1266 1267 if (ipv6_opt_accepted(sk, skb) || 1268 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 1269 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 1270 atomic_inc(&skb->users); 1271 treq->pktopts = skb; 1272 } 1273 1274 if (want_cookie) { 1275 isn = cookie_v6_init_sequence(sk, skb, &req->mss); 1276 req->cookie_ts = tmp_opt.tstamp_ok; 1277 goto have_isn; 1278 } 1279 1280 /* VJ's idea. We save last timestamp seen 1281 * from the destination in peer table, when entering 1282 * state TIME-WAIT, and check against it before 1283 * accepting new connection request. 1284 * 1285 * If "isn" is not zero, this request hit alive 1286 * timewait bucket, so that all the necessary checks 1287 * are made in the function processing timewait state. 1288 */ 1289 if (tmp_opt.saw_tstamp && 1290 tcp_death_row.sysctl_tw_recycle && 1291 (dst = inet6_csk_route_req(sk, req)) != NULL && 1292 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL && 1293 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6, 1294 &treq->rmt_addr)) { 1295 inet_peer_refcheck(peer); 1296 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL && 1297 (s32)(peer->tcp_ts - req->ts_recent) > 1298 TCP_PAWS_WINDOW) { 1299 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); 1300 goto drop_and_release; 1301 } 1302 } 1303 /* Kill the following clause, if you dislike this way. */ 1304 else if (!sysctl_tcp_syncookies && 1305 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < 1306 (sysctl_max_syn_backlog >> 2)) && 1307 (!peer || !peer->tcp_ts_stamp) && 1308 (!dst || !dst_metric(dst, RTAX_RTT))) { 1309 /* Without syncookies last quarter of 1310 * backlog is filled with destinations, 1311 * proven to be alive. 1312 * It means that we continue to communicate 1313 * to destinations, already remembered 1314 * to the moment of synflood. 1315 */ 1316 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n", 1317 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source)); 1318 goto drop_and_release; 1319 } 1320 1321 isn = tcp_v6_init_sequence(skb); 1322 } 1323 have_isn: 1324 tcp_rsk(req)->snt_isn = isn; 1325 tcp_rsk(req)->snt_synack = tcp_time_stamp; 1326 1327 security_inet_conn_request(sk, skb, req); 1328 1329 if (tcp_v6_send_synack(sk, req, 1330 (struct request_values *)&tmp_ext) || 1331 want_cookie) 1332 goto drop_and_free; 1333 1334 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); 1335 return 0; 1336 1337 drop_and_release: 1338 dst_release(dst); 1339 drop_and_free: 1340 reqsk_free(req); 1341 drop: 1342 return 0; /* don't send reset */ 1343 } 1344 1345 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, 1346 struct request_sock *req, 1347 struct dst_entry *dst) 1348 { 1349 struct inet6_request_sock *treq; 1350 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 1351 struct tcp6_sock *newtcp6sk; 1352 struct inet_sock *newinet; 1353 struct tcp_sock *newtp; 1354 struct sock *newsk; 1355 struct ipv6_txoptions *opt; 1356 #ifdef CONFIG_TCP_MD5SIG 1357 struct tcp_md5sig_key *key; 1358 #endif 1359 1360 if (skb->protocol == htons(ETH_P_IP)) { 1361 /* 1362 * v6 mapped 1363 */ 1364 1365 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst); 1366 1367 if (newsk == NULL) 1368 return NULL; 1369 1370 newtcp6sk = (struct tcp6_sock *)newsk; 1371 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6; 1372 1373 newinet = inet_sk(newsk); 1374 newnp = inet6_sk(newsk); 1375 newtp = tcp_sk(newsk); 1376 1377 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1378 1379 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr); 1380 1381 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr); 1382 1383 newnp->rcv_saddr = newnp->saddr; 1384 1385 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; 1386 newsk->sk_backlog_rcv = tcp_v4_do_rcv; 1387 #ifdef CONFIG_TCP_MD5SIG 1388 newtp->af_specific = &tcp_sock_ipv6_mapped_specific; 1389 #endif 1390 1391 newnp->ipv6_ac_list = NULL; 1392 newnp->ipv6_fl_list = NULL; 1393 newnp->pktoptions = NULL; 1394 newnp->opt = NULL; 1395 newnp->mcast_oif = inet6_iif(skb); 1396 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1397 1398 /* 1399 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 1400 * here, tcp_create_openreq_child now does this for us, see the comment in 1401 * that function for the gory details. -acme 1402 */ 1403 1404 /* It is tricky place. Until this moment IPv4 tcp 1405 worked with IPv6 icsk.icsk_af_ops. 1406 Sync it now. 1407 */ 1408 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 1409 1410 return newsk; 1411 } 1412 1413 treq = inet6_rsk(req); 1414 opt = np->opt; 1415 1416 if (sk_acceptq_is_full(sk)) 1417 goto out_overflow; 1418 1419 if (!dst) { 1420 dst = inet6_csk_route_req(sk, req); 1421 if (!dst) 1422 goto out; 1423 } 1424 1425 newsk = tcp_create_openreq_child(sk, req, skb); 1426 if (newsk == NULL) 1427 goto out_nonewsk; 1428 1429 /* 1430 * No need to charge this sock to the relevant IPv6 refcnt debug socks 1431 * count here, tcp_create_openreq_child now does this for us, see the 1432 * comment in that function for the gory details. -acme 1433 */ 1434 1435 newsk->sk_gso_type = SKB_GSO_TCPV6; 1436 __ip6_dst_store(newsk, dst, NULL, NULL); 1437 1438 newtcp6sk = (struct tcp6_sock *)newsk; 1439 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6; 1440 1441 newtp = tcp_sk(newsk); 1442 newinet = inet_sk(newsk); 1443 newnp = inet6_sk(newsk); 1444 1445 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1446 1447 newnp->daddr = treq->rmt_addr; 1448 newnp->saddr = treq->loc_addr; 1449 newnp->rcv_saddr = treq->loc_addr; 1450 newsk->sk_bound_dev_if = treq->iif; 1451 1452 /* Now IPv6 options... 1453 1454 First: no IPv4 options. 1455 */ 1456 newinet->inet_opt = NULL; 1457 newnp->ipv6_ac_list = NULL; 1458 newnp->ipv6_fl_list = NULL; 1459 1460 /* Clone RX bits */ 1461 newnp->rxopt.all = np->rxopt.all; 1462 1463 /* Clone pktoptions received with SYN */ 1464 newnp->pktoptions = NULL; 1465 if (treq->pktopts != NULL) { 1466 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC); 1467 kfree_skb(treq->pktopts); 1468 treq->pktopts = NULL; 1469 if (newnp->pktoptions) 1470 skb_set_owner_r(newnp->pktoptions, newsk); 1471 } 1472 newnp->opt = NULL; 1473 newnp->mcast_oif = inet6_iif(skb); 1474 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1475 1476 /* Clone native IPv6 options from listening socket (if any) 1477 1478 Yes, keeping reference count would be much more clever, 1479 but we make one more one thing there: reattach optmem 1480 to newsk. 1481 */ 1482 if (opt) { 1483 newnp->opt = ipv6_dup_options(newsk, opt); 1484 if (opt != np->opt) 1485 sock_kfree_s(sk, opt, opt->tot_len); 1486 } 1487 1488 inet_csk(newsk)->icsk_ext_hdr_len = 0; 1489 if (newnp->opt) 1490 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen + 1491 newnp->opt->opt_flen); 1492 1493 tcp_mtup_init(newsk); 1494 tcp_sync_mss(newsk, dst_mtu(dst)); 1495 newtp->advmss = dst_metric_advmss(dst); 1496 tcp_initialize_rcv_mss(newsk); 1497 if (tcp_rsk(req)->snt_synack) 1498 tcp_valid_rtt_meas(newsk, 1499 tcp_time_stamp - tcp_rsk(req)->snt_synack); 1500 newtp->total_retrans = req->retrans; 1501 1502 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 1503 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 1504 1505 #ifdef CONFIG_TCP_MD5SIG 1506 /* Copy over the MD5 key from the original socket */ 1507 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) { 1508 /* We're using one, so create a matching key 1509 * on the newsk structure. If we fail to get 1510 * memory, then we end up not copying the key 1511 * across. Shucks. 1512 */ 1513 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC); 1514 if (newkey != NULL) 1515 tcp_v6_md5_do_add(newsk, &newnp->daddr, 1516 newkey, key->keylen); 1517 } 1518 #endif 1519 1520 if (__inet_inherit_port(sk, newsk) < 0) { 1521 sock_put(newsk); 1522 goto out; 1523 } 1524 __inet6_hash(newsk, NULL); 1525 1526 return newsk; 1527 1528 out_overflow: 1529 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 1530 out_nonewsk: 1531 if (opt && opt != np->opt) 1532 sock_kfree_s(sk, opt, opt->tot_len); 1533 dst_release(dst); 1534 out: 1535 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); 1536 return NULL; 1537 } 1538 1539 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb) 1540 { 1541 if (skb->ip_summed == CHECKSUM_COMPLETE) { 1542 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr, 1543 &ipv6_hdr(skb)->daddr, skb->csum)) { 1544 skb->ip_summed = CHECKSUM_UNNECESSARY; 1545 return 0; 1546 } 1547 } 1548 1549 skb->csum = ~csum_unfold(tcp_v6_check(skb->len, 1550 &ipv6_hdr(skb)->saddr, 1551 &ipv6_hdr(skb)->daddr, 0)); 1552 1553 if (skb->len <= 76) { 1554 return __skb_checksum_complete(skb); 1555 } 1556 return 0; 1557 } 1558 1559 /* The socket must have it's spinlock held when we get 1560 * here. 1561 * 1562 * We have a potential double-lock case here, so even when 1563 * doing backlog processing we use the BH locking scheme. 1564 * This is because we cannot sleep with the original spinlock 1565 * held. 1566 */ 1567 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 1568 { 1569 struct ipv6_pinfo *np = inet6_sk(sk); 1570 struct tcp_sock *tp; 1571 struct sk_buff *opt_skb = NULL; 1572 1573 /* Imagine: socket is IPv6. IPv4 packet arrives, 1574 goes to IPv4 receive handler and backlogged. 1575 From backlog it always goes here. Kerboom... 1576 Fortunately, tcp_rcv_established and rcv_established 1577 handle them correctly, but it is not case with 1578 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK 1579 */ 1580 1581 if (skb->protocol == htons(ETH_P_IP)) 1582 return tcp_v4_do_rcv(sk, skb); 1583 1584 #ifdef CONFIG_TCP_MD5SIG 1585 if (tcp_v6_inbound_md5_hash (sk, skb)) 1586 goto discard; 1587 #endif 1588 1589 if (sk_filter(sk, skb)) 1590 goto discard; 1591 1592 /* 1593 * socket locking is here for SMP purposes as backlog rcv 1594 * is currently called with bh processing disabled. 1595 */ 1596 1597 /* Do Stevens' IPV6_PKTOPTIONS. 1598 1599 Yes, guys, it is the only place in our code, where we 1600 may make it not affecting IPv4. 1601 The rest of code is protocol independent, 1602 and I do not like idea to uglify IPv4. 1603 1604 Actually, all the idea behind IPV6_PKTOPTIONS 1605 looks not very well thought. For now we latch 1606 options, received in the last packet, enqueued 1607 by tcp. Feel free to propose better solution. 1608 --ANK (980728) 1609 */ 1610 if (np->rxopt.all) 1611 opt_skb = skb_clone(skb, GFP_ATOMIC); 1612 1613 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ 1614 sock_rps_save_rxhash(sk, skb); 1615 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) 1616 goto reset; 1617 if (opt_skb) 1618 goto ipv6_pktoptions; 1619 return 0; 1620 } 1621 1622 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb)) 1623 goto csum_err; 1624 1625 if (sk->sk_state == TCP_LISTEN) { 1626 struct sock *nsk = tcp_v6_hnd_req(sk, skb); 1627 if (!nsk) 1628 goto discard; 1629 1630 /* 1631 * Queue it on the new socket if the new socket is active, 1632 * otherwise we just shortcircuit this and continue with 1633 * the new socket.. 1634 */ 1635 if(nsk != sk) { 1636 sock_rps_save_rxhash(nsk, skb); 1637 if (tcp_child_process(sk, nsk, skb)) 1638 goto reset; 1639 if (opt_skb) 1640 __kfree_skb(opt_skb); 1641 return 0; 1642 } 1643 } else 1644 sock_rps_save_rxhash(sk, skb); 1645 1646 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) 1647 goto reset; 1648 if (opt_skb) 1649 goto ipv6_pktoptions; 1650 return 0; 1651 1652 reset: 1653 tcp_v6_send_reset(sk, skb); 1654 discard: 1655 if (opt_skb) 1656 __kfree_skb(opt_skb); 1657 kfree_skb(skb); 1658 return 0; 1659 csum_err: 1660 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); 1661 goto discard; 1662 1663 1664 ipv6_pktoptions: 1665 /* Do you ask, what is it? 1666 1667 1. skb was enqueued by tcp. 1668 2. skb is added to tail of read queue, rather than out of order. 1669 3. socket is not in passive state. 1670 4. Finally, it really contains options, which user wants to receive. 1671 */ 1672 tp = tcp_sk(sk); 1673 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && 1674 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { 1675 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) 1676 np->mcast_oif = inet6_iif(opt_skb); 1677 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) 1678 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; 1679 if (ipv6_opt_accepted(sk, opt_skb)) { 1680 skb_set_owner_r(opt_skb, sk); 1681 opt_skb = xchg(&np->pktoptions, opt_skb); 1682 } else { 1683 __kfree_skb(opt_skb); 1684 opt_skb = xchg(&np->pktoptions, NULL); 1685 } 1686 } 1687 1688 kfree_skb(opt_skb); 1689 return 0; 1690 } 1691 1692 static int tcp_v6_rcv(struct sk_buff *skb) 1693 { 1694 const struct tcphdr *th; 1695 const struct ipv6hdr *hdr; 1696 struct sock *sk; 1697 int ret; 1698 struct net *net = dev_net(skb->dev); 1699 1700 if (skb->pkt_type != PACKET_HOST) 1701 goto discard_it; 1702 1703 /* 1704 * Count it even if it's bad. 1705 */ 1706 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); 1707 1708 if (!pskb_may_pull(skb, sizeof(struct tcphdr))) 1709 goto discard_it; 1710 1711 th = tcp_hdr(skb); 1712 1713 if (th->doff < sizeof(struct tcphdr)/4) 1714 goto bad_packet; 1715 if (!pskb_may_pull(skb, th->doff*4)) 1716 goto discard_it; 1717 1718 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb)) 1719 goto bad_packet; 1720 1721 th = tcp_hdr(skb); 1722 hdr = ipv6_hdr(skb); 1723 TCP_SKB_CB(skb)->seq = ntohl(th->seq); 1724 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + 1725 skb->len - th->doff*4); 1726 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); 1727 TCP_SKB_CB(skb)->when = 0; 1728 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); 1729 TCP_SKB_CB(skb)->sacked = 0; 1730 1731 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); 1732 if (!sk) 1733 goto no_tcp_socket; 1734 1735 process: 1736 if (sk->sk_state == TCP_TIME_WAIT) 1737 goto do_time_wait; 1738 1739 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) { 1740 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); 1741 goto discard_and_relse; 1742 } 1743 1744 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 1745 goto discard_and_relse; 1746 1747 if (sk_filter(sk, skb)) 1748 goto discard_and_relse; 1749 1750 skb->dev = NULL; 1751 1752 bh_lock_sock_nested(sk); 1753 ret = 0; 1754 if (!sock_owned_by_user(sk)) { 1755 #ifdef CONFIG_NET_DMA 1756 struct tcp_sock *tp = tcp_sk(sk); 1757 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) 1758 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); 1759 if (tp->ucopy.dma_chan) 1760 ret = tcp_v6_do_rcv(sk, skb); 1761 else 1762 #endif 1763 { 1764 if (!tcp_prequeue(sk, skb)) 1765 ret = tcp_v6_do_rcv(sk, skb); 1766 } 1767 } else if (unlikely(sk_add_backlog(sk, skb))) { 1768 bh_unlock_sock(sk); 1769 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); 1770 goto discard_and_relse; 1771 } 1772 bh_unlock_sock(sk); 1773 1774 sock_put(sk); 1775 return ret ? -1 : 0; 1776 1777 no_tcp_socket: 1778 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 1779 goto discard_it; 1780 1781 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { 1782 bad_packet: 1783 TCP_INC_STATS_BH(net, TCP_MIB_INERRS); 1784 } else { 1785 tcp_v6_send_reset(NULL, skb); 1786 } 1787 1788 discard_it: 1789 1790 /* 1791 * Discard frame 1792 */ 1793 1794 kfree_skb(skb); 1795 return 0; 1796 1797 discard_and_relse: 1798 sock_put(sk); 1799 goto discard_it; 1800 1801 do_time_wait: 1802 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1803 inet_twsk_put(inet_twsk(sk)); 1804 goto discard_it; 1805 } 1806 1807 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) { 1808 TCP_INC_STATS_BH(net, TCP_MIB_INERRS); 1809 inet_twsk_put(inet_twsk(sk)); 1810 goto discard_it; 1811 } 1812 1813 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { 1814 case TCP_TW_SYN: 1815 { 1816 struct sock *sk2; 1817 1818 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, 1819 &ipv6_hdr(skb)->daddr, 1820 ntohs(th->dest), inet6_iif(skb)); 1821 if (sk2 != NULL) { 1822 struct inet_timewait_sock *tw = inet_twsk(sk); 1823 inet_twsk_deschedule(tw, &tcp_death_row); 1824 inet_twsk_put(tw); 1825 sk = sk2; 1826 goto process; 1827 } 1828 /* Fall through to ACK */ 1829 } 1830 case TCP_TW_ACK: 1831 tcp_v6_timewait_ack(sk, skb); 1832 break; 1833 case TCP_TW_RST: 1834 goto no_tcp_socket; 1835 case TCP_TW_SUCCESS:; 1836 } 1837 goto discard_it; 1838 } 1839 1840 static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it) 1841 { 1842 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk); 1843 struct ipv6_pinfo *np = inet6_sk(sk); 1844 struct inet_peer *peer; 1845 1846 if (!rt || 1847 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) { 1848 peer = inet_getpeer_v6(&np->daddr, 1); 1849 *release_it = true; 1850 } else { 1851 if (!rt->rt6i_peer) 1852 rt6_bind_peer(rt, 1); 1853 peer = rt->rt6i_peer; 1854 *release_it = false; 1855 } 1856 1857 return peer; 1858 } 1859 1860 static void *tcp_v6_tw_get_peer(struct sock *sk) 1861 { 1862 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk); 1863 const struct inet_timewait_sock *tw = inet_twsk(sk); 1864 1865 if (tw->tw_family == AF_INET) 1866 return tcp_v4_tw_get_peer(sk); 1867 1868 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1); 1869 } 1870 1871 static struct timewait_sock_ops tcp6_timewait_sock_ops = { 1872 .twsk_obj_size = sizeof(struct tcp6_timewait_sock), 1873 .twsk_unique = tcp_twsk_unique, 1874 .twsk_destructor= tcp_twsk_destructor, 1875 .twsk_getpeer = tcp_v6_tw_get_peer, 1876 }; 1877 1878 static const struct inet_connection_sock_af_ops ipv6_specific = { 1879 .queue_xmit = inet6_csk_xmit, 1880 .send_check = tcp_v6_send_check, 1881 .rebuild_header = inet6_sk_rebuild_header, 1882 .conn_request = tcp_v6_conn_request, 1883 .syn_recv_sock = tcp_v6_syn_recv_sock, 1884 .get_peer = tcp_v6_get_peer, 1885 .net_header_len = sizeof(struct ipv6hdr), 1886 .setsockopt = ipv6_setsockopt, 1887 .getsockopt = ipv6_getsockopt, 1888 .addr2sockaddr = inet6_csk_addr2sockaddr, 1889 .sockaddr_len = sizeof(struct sockaddr_in6), 1890 .bind_conflict = inet6_csk_bind_conflict, 1891 #ifdef CONFIG_COMPAT 1892 .compat_setsockopt = compat_ipv6_setsockopt, 1893 .compat_getsockopt = compat_ipv6_getsockopt, 1894 #endif 1895 }; 1896 1897 #ifdef CONFIG_TCP_MD5SIG 1898 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { 1899 .md5_lookup = tcp_v6_md5_lookup, 1900 .calc_md5_hash = tcp_v6_md5_hash_skb, 1901 .md5_add = tcp_v6_md5_add_func, 1902 .md5_parse = tcp_v6_parse_md5_keys, 1903 }; 1904 #endif 1905 1906 /* 1907 * TCP over IPv4 via INET6 API 1908 */ 1909 1910 static const struct inet_connection_sock_af_ops ipv6_mapped = { 1911 .queue_xmit = ip_queue_xmit, 1912 .send_check = tcp_v4_send_check, 1913 .rebuild_header = inet_sk_rebuild_header, 1914 .conn_request = tcp_v6_conn_request, 1915 .syn_recv_sock = tcp_v6_syn_recv_sock, 1916 .get_peer = tcp_v4_get_peer, 1917 .net_header_len = sizeof(struct iphdr), 1918 .setsockopt = ipv6_setsockopt, 1919 .getsockopt = ipv6_getsockopt, 1920 .addr2sockaddr = inet6_csk_addr2sockaddr, 1921 .sockaddr_len = sizeof(struct sockaddr_in6), 1922 .bind_conflict = inet6_csk_bind_conflict, 1923 #ifdef CONFIG_COMPAT 1924 .compat_setsockopt = compat_ipv6_setsockopt, 1925 .compat_getsockopt = compat_ipv6_getsockopt, 1926 #endif 1927 }; 1928 1929 #ifdef CONFIG_TCP_MD5SIG 1930 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { 1931 .md5_lookup = tcp_v4_md5_lookup, 1932 .calc_md5_hash = tcp_v4_md5_hash_skb, 1933 .md5_add = tcp_v6_md5_add_func, 1934 .md5_parse = tcp_v6_parse_md5_keys, 1935 }; 1936 #endif 1937 1938 /* NOTE: A lot of things set to zero explicitly by call to 1939 * sk_alloc() so need not be done here. 1940 */ 1941 static int tcp_v6_init_sock(struct sock *sk) 1942 { 1943 struct inet_connection_sock *icsk = inet_csk(sk); 1944 struct tcp_sock *tp = tcp_sk(sk); 1945 1946 skb_queue_head_init(&tp->out_of_order_queue); 1947 tcp_init_xmit_timers(sk); 1948 tcp_prequeue_init(tp); 1949 1950 icsk->icsk_rto = TCP_TIMEOUT_INIT; 1951 tp->mdev = TCP_TIMEOUT_INIT; 1952 1953 /* So many TCP implementations out there (incorrectly) count the 1954 * initial SYN frame in their delayed-ACK and congestion control 1955 * algorithms that we must have the following bandaid to talk 1956 * efficiently to them. -DaveM 1957 */ 1958 tp->snd_cwnd = 2; 1959 1960 /* See draft-stevens-tcpca-spec-01 for discussion of the 1961 * initialization of these values. 1962 */ 1963 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; 1964 tp->snd_cwnd_clamp = ~0; 1965 tp->mss_cache = TCP_MSS_DEFAULT; 1966 1967 tp->reordering = sysctl_tcp_reordering; 1968 1969 sk->sk_state = TCP_CLOSE; 1970 1971 icsk->icsk_af_ops = &ipv6_specific; 1972 icsk->icsk_ca_ops = &tcp_init_congestion_ops; 1973 icsk->icsk_sync_mss = tcp_sync_mss; 1974 sk->sk_write_space = sk_stream_write_space; 1975 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); 1976 1977 #ifdef CONFIG_TCP_MD5SIG 1978 tp->af_specific = &tcp_sock_ipv6_specific; 1979 #endif 1980 1981 /* TCP Cookie Transactions */ 1982 if (sysctl_tcp_cookie_size > 0) { 1983 /* Default, cookies without s_data_payload. */ 1984 tp->cookie_values = 1985 kzalloc(sizeof(*tp->cookie_values), 1986 sk->sk_allocation); 1987 if (tp->cookie_values != NULL) 1988 kref_init(&tp->cookie_values->kref); 1989 } 1990 /* Presumed zeroed, in order of appearance: 1991 * cookie_in_always, cookie_out_never, 1992 * s_data_constant, s_data_in, s_data_out 1993 */ 1994 sk->sk_sndbuf = sysctl_tcp_wmem[1]; 1995 sk->sk_rcvbuf = sysctl_tcp_rmem[1]; 1996 1997 local_bh_disable(); 1998 sock_update_memcg(sk); 1999 sk_sockets_allocated_inc(sk); 2000 local_bh_enable(); 2001 2002 return 0; 2003 } 2004 2005 static void tcp_v6_destroy_sock(struct sock *sk) 2006 { 2007 #ifdef CONFIG_TCP_MD5SIG 2008 /* Clean up the MD5 key list */ 2009 if (tcp_sk(sk)->md5sig_info) 2010 tcp_v6_clear_md5_list(sk); 2011 #endif 2012 tcp_v4_destroy_sock(sk); 2013 inet6_destroy_sock(sk); 2014 } 2015 2016 #ifdef CONFIG_PROC_FS 2017 /* Proc filesystem TCPv6 sock list dumping. */ 2018 static void get_openreq6(struct seq_file *seq, 2019 const struct sock *sk, struct request_sock *req, int i, int uid) 2020 { 2021 int ttd = req->expires - jiffies; 2022 const struct in6_addr *src = &inet6_rsk(req)->loc_addr; 2023 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr; 2024 2025 if (ttd < 0) 2026 ttd = 0; 2027 2028 seq_printf(seq, 2029 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2030 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 2031 i, 2032 src->s6_addr32[0], src->s6_addr32[1], 2033 src->s6_addr32[2], src->s6_addr32[3], 2034 ntohs(inet_rsk(req)->loc_port), 2035 dest->s6_addr32[0], dest->s6_addr32[1], 2036 dest->s6_addr32[2], dest->s6_addr32[3], 2037 ntohs(inet_rsk(req)->rmt_port), 2038 TCP_SYN_RECV, 2039 0,0, /* could print option size, but that is af dependent. */ 2040 1, /* timers active (only the expire timer) */ 2041 jiffies_to_clock_t(ttd), 2042 req->retrans, 2043 uid, 2044 0, /* non standard timer */ 2045 0, /* open_requests have no inode */ 2046 0, req); 2047 } 2048 2049 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 2050 { 2051 const struct in6_addr *dest, *src; 2052 __u16 destp, srcp; 2053 int timer_active; 2054 unsigned long timer_expires; 2055 const struct inet_sock *inet = inet_sk(sp); 2056 const struct tcp_sock *tp = tcp_sk(sp); 2057 const struct inet_connection_sock *icsk = inet_csk(sp); 2058 const struct ipv6_pinfo *np = inet6_sk(sp); 2059 2060 dest = &np->daddr; 2061 src = &np->rcv_saddr; 2062 destp = ntohs(inet->inet_dport); 2063 srcp = ntohs(inet->inet_sport); 2064 2065 if (icsk->icsk_pending == ICSK_TIME_RETRANS) { 2066 timer_active = 1; 2067 timer_expires = icsk->icsk_timeout; 2068 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 2069 timer_active = 4; 2070 timer_expires = icsk->icsk_timeout; 2071 } else if (timer_pending(&sp->sk_timer)) { 2072 timer_active = 2; 2073 timer_expires = sp->sk_timer.expires; 2074 } else { 2075 timer_active = 0; 2076 timer_expires = jiffies; 2077 } 2078 2079 seq_printf(seq, 2080 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2081 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n", 2082 i, 2083 src->s6_addr32[0], src->s6_addr32[1], 2084 src->s6_addr32[2], src->s6_addr32[3], srcp, 2085 dest->s6_addr32[0], dest->s6_addr32[1], 2086 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2087 sp->sk_state, 2088 tp->write_seq-tp->snd_una, 2089 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq), 2090 timer_active, 2091 jiffies_to_clock_t(timer_expires - jiffies), 2092 icsk->icsk_retransmits, 2093 sock_i_uid(sp), 2094 icsk->icsk_probes_out, 2095 sock_i_ino(sp), 2096 atomic_read(&sp->sk_refcnt), sp, 2097 jiffies_to_clock_t(icsk->icsk_rto), 2098 jiffies_to_clock_t(icsk->icsk_ack.ato), 2099 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong, 2100 tp->snd_cwnd, 2101 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh 2102 ); 2103 } 2104 2105 static void get_timewait6_sock(struct seq_file *seq, 2106 struct inet_timewait_sock *tw, int i) 2107 { 2108 const struct in6_addr *dest, *src; 2109 __u16 destp, srcp; 2110 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw); 2111 int ttd = tw->tw_ttd - jiffies; 2112 2113 if (ttd < 0) 2114 ttd = 0; 2115 2116 dest = &tw6->tw_v6_daddr; 2117 src = &tw6->tw_v6_rcv_saddr; 2118 destp = ntohs(tw->tw_dport); 2119 srcp = ntohs(tw->tw_sport); 2120 2121 seq_printf(seq, 2122 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2123 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 2124 i, 2125 src->s6_addr32[0], src->s6_addr32[1], 2126 src->s6_addr32[2], src->s6_addr32[3], srcp, 2127 dest->s6_addr32[0], dest->s6_addr32[1], 2128 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2129 tw->tw_substate, 0, 0, 2130 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, 2131 atomic_read(&tw->tw_refcnt), tw); 2132 } 2133 2134 static int tcp6_seq_show(struct seq_file *seq, void *v) 2135 { 2136 struct tcp_iter_state *st; 2137 2138 if (v == SEQ_START_TOKEN) { 2139 seq_puts(seq, 2140 " sl " 2141 "local_address " 2142 "remote_address " 2143 "st tx_queue rx_queue tr tm->when retrnsmt" 2144 " uid timeout inode\n"); 2145 goto out; 2146 } 2147 st = seq->private; 2148 2149 switch (st->state) { 2150 case TCP_SEQ_STATE_LISTENING: 2151 case TCP_SEQ_STATE_ESTABLISHED: 2152 get_tcp6_sock(seq, v, st->num); 2153 break; 2154 case TCP_SEQ_STATE_OPENREQ: 2155 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid); 2156 break; 2157 case TCP_SEQ_STATE_TIME_WAIT: 2158 get_timewait6_sock(seq, v, st->num); 2159 break; 2160 } 2161 out: 2162 return 0; 2163 } 2164 2165 static const struct file_operations tcp6_afinfo_seq_fops = { 2166 .owner = THIS_MODULE, 2167 .open = tcp_seq_open, 2168 .read = seq_read, 2169 .llseek = seq_lseek, 2170 .release = seq_release_net 2171 }; 2172 2173 static struct tcp_seq_afinfo tcp6_seq_afinfo = { 2174 .name = "tcp6", 2175 .family = AF_INET6, 2176 .seq_fops = &tcp6_afinfo_seq_fops, 2177 .seq_ops = { 2178 .show = tcp6_seq_show, 2179 }, 2180 }; 2181 2182 int __net_init tcp6_proc_init(struct net *net) 2183 { 2184 return tcp_proc_register(net, &tcp6_seq_afinfo); 2185 } 2186 2187 void tcp6_proc_exit(struct net *net) 2188 { 2189 tcp_proc_unregister(net, &tcp6_seq_afinfo); 2190 } 2191 #endif 2192 2193 struct proto tcpv6_prot = { 2194 .name = "TCPv6", 2195 .owner = THIS_MODULE, 2196 .close = tcp_close, 2197 .connect = tcp_v6_connect, 2198 .disconnect = tcp_disconnect, 2199 .accept = inet_csk_accept, 2200 .ioctl = tcp_ioctl, 2201 .init = tcp_v6_init_sock, 2202 .destroy = tcp_v6_destroy_sock, 2203 .shutdown = tcp_shutdown, 2204 .setsockopt = tcp_setsockopt, 2205 .getsockopt = tcp_getsockopt, 2206 .recvmsg = tcp_recvmsg, 2207 .sendmsg = tcp_sendmsg, 2208 .sendpage = tcp_sendpage, 2209 .backlog_rcv = tcp_v6_do_rcv, 2210 .hash = tcp_v6_hash, 2211 .unhash = inet_unhash, 2212 .get_port = inet_csk_get_port, 2213 .enter_memory_pressure = tcp_enter_memory_pressure, 2214 .sockets_allocated = &tcp_sockets_allocated, 2215 .memory_allocated = &tcp_memory_allocated, 2216 .memory_pressure = &tcp_memory_pressure, 2217 .orphan_count = &tcp_orphan_count, 2218 .sysctl_wmem = sysctl_tcp_wmem, 2219 .sysctl_rmem = sysctl_tcp_rmem, 2220 .max_header = MAX_TCP_HEADER, 2221 .obj_size = sizeof(struct tcp6_sock), 2222 .slab_flags = SLAB_DESTROY_BY_RCU, 2223 .twsk_prot = &tcp6_timewait_sock_ops, 2224 .rsk_prot = &tcp6_request_sock_ops, 2225 .h.hashinfo = &tcp_hashinfo, 2226 .no_autobind = true, 2227 #ifdef CONFIG_COMPAT 2228 .compat_setsockopt = compat_tcp_setsockopt, 2229 .compat_getsockopt = compat_tcp_getsockopt, 2230 #endif 2231 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM 2232 .proto_cgroup = tcp_proto_cgroup, 2233 #endif 2234 }; 2235 2236 static const struct inet6_protocol tcpv6_protocol = { 2237 .handler = tcp_v6_rcv, 2238 .err_handler = tcp_v6_err, 2239 .gso_send_check = tcp_v6_gso_send_check, 2240 .gso_segment = tcp_tso_segment, 2241 .gro_receive = tcp6_gro_receive, 2242 .gro_complete = tcp6_gro_complete, 2243 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 2244 }; 2245 2246 static struct inet_protosw tcpv6_protosw = { 2247 .type = SOCK_STREAM, 2248 .protocol = IPPROTO_TCP, 2249 .prot = &tcpv6_prot, 2250 .ops = &inet6_stream_ops, 2251 .no_check = 0, 2252 .flags = INET_PROTOSW_PERMANENT | 2253 INET_PROTOSW_ICSK, 2254 }; 2255 2256 static int __net_init tcpv6_net_init(struct net *net) 2257 { 2258 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, 2259 SOCK_RAW, IPPROTO_TCP, net); 2260 } 2261 2262 static void __net_exit tcpv6_net_exit(struct net *net) 2263 { 2264 inet_ctl_sock_destroy(net->ipv6.tcp_sk); 2265 } 2266 2267 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) 2268 { 2269 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6); 2270 } 2271 2272 static struct pernet_operations tcpv6_net_ops = { 2273 .init = tcpv6_net_init, 2274 .exit = tcpv6_net_exit, 2275 .exit_batch = tcpv6_net_exit_batch, 2276 }; 2277 2278 int __init tcpv6_init(void) 2279 { 2280 int ret; 2281 2282 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); 2283 if (ret) 2284 goto out; 2285 2286 /* register inet6 protocol */ 2287 ret = inet6_register_protosw(&tcpv6_protosw); 2288 if (ret) 2289 goto out_tcpv6_protocol; 2290 2291 ret = register_pernet_subsys(&tcpv6_net_ops); 2292 if (ret) 2293 goto out_tcpv6_protosw; 2294 out: 2295 return ret; 2296 2297 out_tcpv6_protocol: 2298 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2299 out_tcpv6_protosw: 2300 inet6_unregister_protosw(&tcpv6_protosw); 2301 goto out; 2302 } 2303 2304 void tcpv6_exit(void) 2305 { 2306 unregister_pernet_subsys(&tcpv6_net_ops); 2307 inet6_unregister_protosw(&tcpv6_protosw); 2308 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2309 } 2310