1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * TCP over IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Based on: 10 * linux/net/ipv4/tcp.c 11 * linux/net/ipv4/tcp_input.c 12 * linux/net/ipv4/tcp_output.c 13 * 14 * Fixes: 15 * Hideaki YOSHIFUJI : sin6_scope_id support 16 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 17 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind 18 * a single port at the same time. 19 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file. 20 */ 21 22 #include <linux/bottom_half.h> 23 #include <linux/module.h> 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/jiffies.h> 30 #include <linux/in.h> 31 #include <linux/in6.h> 32 #include <linux/netdevice.h> 33 #include <linux/init.h> 34 #include <linux/jhash.h> 35 #include <linux/ipsec.h> 36 #include <linux/times.h> 37 #include <linux/slab.h> 38 #include <linux/uaccess.h> 39 #include <linux/ipv6.h> 40 #include <linux/icmpv6.h> 41 #include <linux/random.h> 42 #include <linux/indirect_call_wrapper.h> 43 44 #include <net/tcp.h> 45 #include <net/ndisc.h> 46 #include <net/inet6_hashtables.h> 47 #include <net/inet6_connection_sock.h> 48 #include <net/ipv6.h> 49 #include <net/transp_v6.h> 50 #include <net/addrconf.h> 51 #include <net/ip6_route.h> 52 #include <net/ip6_checksum.h> 53 #include <net/inet_ecn.h> 54 #include <net/protocol.h> 55 #include <net/xfrm.h> 56 #include <net/snmp.h> 57 #include <net/dsfield.h> 58 #include <net/timewait_sock.h> 59 #include <net/inet_common.h> 60 #include <net/secure_seq.h> 61 #include <net/busy_poll.h> 62 63 #include <linux/proc_fs.h> 64 #include <linux/seq_file.h> 65 66 #include <crypto/hash.h> 67 #include <linux/scatterlist.h> 68 69 #include <trace/events/tcp.h> 70 71 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb); 72 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 73 struct request_sock *req); 74 75 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); 76 77 static const struct inet_connection_sock_af_ops ipv6_mapped; 78 const struct inet_connection_sock_af_ops ipv6_specific; 79 #ifdef CONFIG_TCP_MD5SIG 80 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; 81 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; 82 #else 83 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, 84 const struct in6_addr *addr, 85 int l3index) 86 { 87 return NULL; 88 } 89 #endif 90 91 /* Helper returning the inet6 address from a given tcp socket. 92 * It can be used in TCP stack instead of inet6_sk(sk). 93 * This avoids a dereference and allow compiler optimizations. 94 * It is a specialized version of inet6_sk_generic(). 95 */ 96 static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk) 97 { 98 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo); 99 100 return (struct ipv6_pinfo *)(((u8 *)sk) + offset); 101 } 102 103 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) 104 { 105 struct dst_entry *dst = skb_dst(skb); 106 107 if (dst && dst_hold_safe(dst)) { 108 const struct rt6_info *rt = (const struct rt6_info *)dst; 109 110 sk->sk_rx_dst = dst; 111 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; 112 tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); 113 } 114 } 115 116 static u32 tcp_v6_init_seq(const struct sk_buff *skb) 117 { 118 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32, 119 ipv6_hdr(skb)->saddr.s6_addr32, 120 tcp_hdr(skb)->dest, 121 tcp_hdr(skb)->source); 122 } 123 124 static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb) 125 { 126 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32, 127 ipv6_hdr(skb)->saddr.s6_addr32); 128 } 129 130 static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, 131 int addr_len) 132 { 133 /* This check is replicated from tcp_v6_connect() and intended to 134 * prevent BPF program called below from accessing bytes that are out 135 * of the bound specified by user in addr_len. 136 */ 137 if (addr_len < SIN6_LEN_RFC2133) 138 return -EINVAL; 139 140 sock_owned_by_me(sk); 141 142 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr); 143 } 144 145 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 146 int addr_len) 147 { 148 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 149 struct inet_sock *inet = inet_sk(sk); 150 struct inet_connection_sock *icsk = inet_csk(sk); 151 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 152 struct tcp_sock *tp = tcp_sk(sk); 153 struct in6_addr *saddr = NULL, *final_p, final; 154 struct ipv6_txoptions *opt; 155 struct flowi6 fl6; 156 struct dst_entry *dst; 157 int addr_type; 158 int err; 159 struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; 160 161 if (addr_len < SIN6_LEN_RFC2133) 162 return -EINVAL; 163 164 if (usin->sin6_family != AF_INET6) 165 return -EAFNOSUPPORT; 166 167 memset(&fl6, 0, sizeof(fl6)); 168 169 if (np->sndflow) { 170 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; 171 IP6_ECN_flow_init(fl6.flowlabel); 172 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 173 struct ip6_flowlabel *flowlabel; 174 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 175 if (IS_ERR(flowlabel)) 176 return -EINVAL; 177 fl6_sock_release(flowlabel); 178 } 179 } 180 181 /* 182 * connect() to INADDR_ANY means loopback (BSD'ism). 183 */ 184 185 if (ipv6_addr_any(&usin->sin6_addr)) { 186 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) 187 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 188 &usin->sin6_addr); 189 else 190 usin->sin6_addr = in6addr_loopback; 191 } 192 193 addr_type = ipv6_addr_type(&usin->sin6_addr); 194 195 if (addr_type & IPV6_ADDR_MULTICAST) 196 return -ENETUNREACH; 197 198 if (addr_type&IPV6_ADDR_LINKLOCAL) { 199 if (addr_len >= sizeof(struct sockaddr_in6) && 200 usin->sin6_scope_id) { 201 /* If interface is set while binding, indices 202 * must coincide. 203 */ 204 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) 205 return -EINVAL; 206 207 sk->sk_bound_dev_if = usin->sin6_scope_id; 208 } 209 210 /* Connect to link-local address requires an interface */ 211 if (!sk->sk_bound_dev_if) 212 return -EINVAL; 213 } 214 215 if (tp->rx_opt.ts_recent_stamp && 216 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { 217 tp->rx_opt.ts_recent = 0; 218 tp->rx_opt.ts_recent_stamp = 0; 219 WRITE_ONCE(tp->write_seq, 0); 220 } 221 222 sk->sk_v6_daddr = usin->sin6_addr; 223 np->flow_label = fl6.flowlabel; 224 225 /* 226 * TCP over IPv4 227 */ 228 229 if (addr_type & IPV6_ADDR_MAPPED) { 230 u32 exthdrlen = icsk->icsk_ext_hdr_len; 231 struct sockaddr_in sin; 232 233 if (__ipv6_only_sock(sk)) 234 return -ENETUNREACH; 235 236 sin.sin_family = AF_INET; 237 sin.sin_port = usin->sin6_port; 238 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 239 240 icsk->icsk_af_ops = &ipv6_mapped; 241 if (sk_is_mptcp(sk)) 242 mptcpv6_handle_mapped(sk, true); 243 sk->sk_backlog_rcv = tcp_v4_do_rcv; 244 #ifdef CONFIG_TCP_MD5SIG 245 tp->af_specific = &tcp_sock_ipv6_mapped_specific; 246 #endif 247 248 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 249 250 if (err) { 251 icsk->icsk_ext_hdr_len = exthdrlen; 252 icsk->icsk_af_ops = &ipv6_specific; 253 if (sk_is_mptcp(sk)) 254 mptcpv6_handle_mapped(sk, false); 255 sk->sk_backlog_rcv = tcp_v6_do_rcv; 256 #ifdef CONFIG_TCP_MD5SIG 257 tp->af_specific = &tcp_sock_ipv6_specific; 258 #endif 259 goto failure; 260 } 261 np->saddr = sk->sk_v6_rcv_saddr; 262 263 return err; 264 } 265 266 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 267 saddr = &sk->sk_v6_rcv_saddr; 268 269 fl6.flowi6_proto = IPPROTO_TCP; 270 fl6.daddr = sk->sk_v6_daddr; 271 fl6.saddr = saddr ? *saddr : np->saddr; 272 fl6.flowi6_oif = sk->sk_bound_dev_if; 273 fl6.flowi6_mark = sk->sk_mark; 274 fl6.fl6_dport = usin->sin6_port; 275 fl6.fl6_sport = inet->inet_sport; 276 fl6.flowi6_uid = sk->sk_uid; 277 278 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); 279 final_p = fl6_update_dst(&fl6, opt, &final); 280 281 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); 282 283 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); 284 if (IS_ERR(dst)) { 285 err = PTR_ERR(dst); 286 goto failure; 287 } 288 289 if (!saddr) { 290 saddr = &fl6.saddr; 291 sk->sk_v6_rcv_saddr = *saddr; 292 } 293 294 /* set the source address */ 295 np->saddr = *saddr; 296 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 297 298 sk->sk_gso_type = SKB_GSO_TCPV6; 299 ip6_dst_store(sk, dst, NULL, NULL); 300 301 icsk->icsk_ext_hdr_len = 0; 302 if (opt) 303 icsk->icsk_ext_hdr_len = opt->opt_flen + 304 opt->opt_nflen; 305 306 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); 307 308 inet->inet_dport = usin->sin6_port; 309 310 tcp_set_state(sk, TCP_SYN_SENT); 311 err = inet6_hash_connect(tcp_death_row, sk); 312 if (err) 313 goto late_failure; 314 315 sk_set_txhash(sk); 316 317 if (likely(!tp->repair)) { 318 if (!tp->write_seq) 319 WRITE_ONCE(tp->write_seq, 320 secure_tcpv6_seq(np->saddr.s6_addr32, 321 sk->sk_v6_daddr.s6_addr32, 322 inet->inet_sport, 323 inet->inet_dport)); 324 tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk), 325 np->saddr.s6_addr32, 326 sk->sk_v6_daddr.s6_addr32); 327 } 328 329 if (tcp_fastopen_defer_connect(sk, &err)) 330 return err; 331 if (err) 332 goto late_failure; 333 334 err = tcp_connect(sk); 335 if (err) 336 goto late_failure; 337 338 return 0; 339 340 late_failure: 341 tcp_set_state(sk, TCP_CLOSE); 342 failure: 343 inet->inet_dport = 0; 344 sk->sk_route_caps = 0; 345 return err; 346 } 347 348 static void tcp_v6_mtu_reduced(struct sock *sk) 349 { 350 struct dst_entry *dst; 351 352 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) 353 return; 354 355 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info); 356 if (!dst) 357 return; 358 359 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { 360 tcp_sync_mss(sk, dst_mtu(dst)); 361 tcp_simple_retransmit(sk); 362 } 363 } 364 365 static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 366 u8 type, u8 code, int offset, __be32 info) 367 { 368 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 369 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); 370 struct net *net = dev_net(skb->dev); 371 struct request_sock *fastopen; 372 struct ipv6_pinfo *np; 373 struct tcp_sock *tp; 374 __u32 seq, snd_una; 375 struct sock *sk; 376 bool fatal; 377 int err; 378 379 sk = __inet6_lookup_established(net, &tcp_hashinfo, 380 &hdr->daddr, th->dest, 381 &hdr->saddr, ntohs(th->source), 382 skb->dev->ifindex, inet6_sdif(skb)); 383 384 if (!sk) { 385 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 386 ICMP6_MIB_INERRORS); 387 return -ENOENT; 388 } 389 390 if (sk->sk_state == TCP_TIME_WAIT) { 391 inet_twsk_put(inet_twsk(sk)); 392 return 0; 393 } 394 seq = ntohl(th->seq); 395 fatal = icmpv6_err_convert(type, code, &err); 396 if (sk->sk_state == TCP_NEW_SYN_RECV) { 397 tcp_req_err(sk, seq, fatal); 398 return 0; 399 } 400 401 bh_lock_sock(sk); 402 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) 403 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); 404 405 if (sk->sk_state == TCP_CLOSE) 406 goto out; 407 408 if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) { 409 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 410 goto out; 411 } 412 413 tp = tcp_sk(sk); 414 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ 415 fastopen = rcu_dereference(tp->fastopen_rsk); 416 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; 417 if (sk->sk_state != TCP_LISTEN && 418 !between(seq, snd_una, tp->snd_nxt)) { 419 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); 420 goto out; 421 } 422 423 np = tcp_inet6_sk(sk); 424 425 if (type == NDISC_REDIRECT) { 426 if (!sock_owned_by_user(sk)) { 427 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 428 429 if (dst) 430 dst->ops->redirect(dst, sk, skb); 431 } 432 goto out; 433 } 434 435 if (type == ICMPV6_PKT_TOOBIG) { 436 /* We are not interested in TCP_LISTEN and open_requests 437 * (SYN-ACKs send out by Linux are always <576bytes so 438 * they should go through unfragmented). 439 */ 440 if (sk->sk_state == TCP_LISTEN) 441 goto out; 442 443 if (!ip6_sk_accept_pmtu(sk)) 444 goto out; 445 446 tp->mtu_info = ntohl(info); 447 if (!sock_owned_by_user(sk)) 448 tcp_v6_mtu_reduced(sk); 449 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, 450 &sk->sk_tsq_flags)) 451 sock_hold(sk); 452 goto out; 453 } 454 455 456 /* Might be for an request_sock */ 457 switch (sk->sk_state) { 458 case TCP_SYN_SENT: 459 case TCP_SYN_RECV: 460 /* Only in fast or simultaneous open. If a fast open socket is 461 * already accepted it is treated as a connected one below. 462 */ 463 if (fastopen && !fastopen->sk) 464 break; 465 466 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th); 467 468 if (!sock_owned_by_user(sk)) { 469 sk->sk_err = err; 470 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ 471 472 tcp_done(sk); 473 } else 474 sk->sk_err_soft = err; 475 goto out; 476 case TCP_LISTEN: 477 break; 478 default: 479 /* check if this ICMP message allows revert of backoff. 480 * (see RFC 6069) 481 */ 482 if (!fastopen && type == ICMPV6_DEST_UNREACH && 483 code == ICMPV6_NOROUTE) 484 tcp_ld_RTO_revert(sk, seq); 485 } 486 487 if (!sock_owned_by_user(sk) && np->recverr) { 488 sk->sk_err = err; 489 sk->sk_error_report(sk); 490 } else 491 sk->sk_err_soft = err; 492 493 out: 494 bh_unlock_sock(sk); 495 sock_put(sk); 496 return 0; 497 } 498 499 500 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, 501 struct flowi *fl, 502 struct request_sock *req, 503 struct tcp_fastopen_cookie *foc, 504 enum tcp_synack_type synack_type, 505 struct sk_buff *syn_skb) 506 { 507 struct inet_request_sock *ireq = inet_rsk(req); 508 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 509 struct ipv6_txoptions *opt; 510 struct flowi6 *fl6 = &fl->u.ip6; 511 struct sk_buff *skb; 512 int err = -ENOMEM; 513 u8 tclass; 514 515 /* First, grab a route. */ 516 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req, 517 IPPROTO_TCP)) == NULL) 518 goto done; 519 520 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); 521 522 if (skb) { 523 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, 524 &ireq->ir_v6_rmt_addr); 525 526 fl6->daddr = ireq->ir_v6_rmt_addr; 527 if (np->repflow && ireq->pktopts) 528 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); 529 530 tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ? 531 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | 532 (np->tclass & INET_ECN_MASK) : 533 np->tclass; 534 535 if (!INET_ECN_is_capable(tclass) && 536 tcp_bpf_ca_needs_ecn((struct sock *)req)) 537 tclass |= INET_ECN_ECT_0; 538 539 rcu_read_lock(); 540 opt = ireq->ipv6_opt; 541 if (!opt) 542 opt = rcu_dereference(np->opt); 543 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, 544 tclass, sk->sk_priority); 545 rcu_read_unlock(); 546 err = net_xmit_eval(err); 547 } 548 549 done: 550 return err; 551 } 552 553 554 static void tcp_v6_reqsk_destructor(struct request_sock *req) 555 { 556 kfree(inet_rsk(req)->ipv6_opt); 557 kfree_skb(inet_rsk(req)->pktopts); 558 } 559 560 #ifdef CONFIG_TCP_MD5SIG 561 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, 562 const struct in6_addr *addr, 563 int l3index) 564 { 565 return tcp_md5_do_lookup(sk, l3index, 566 (union tcp_md5_addr *)addr, AF_INET6); 567 } 568 569 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, 570 const struct sock *addr_sk) 571 { 572 int l3index; 573 574 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), 575 addr_sk->sk_bound_dev_if); 576 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr, 577 l3index); 578 } 579 580 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, 581 sockptr_t optval, int optlen) 582 { 583 struct tcp_md5sig cmd; 584 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; 585 int l3index = 0; 586 u8 prefixlen; 587 588 if (optlen < sizeof(cmd)) 589 return -EINVAL; 590 591 if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) 592 return -EFAULT; 593 594 if (sin6->sin6_family != AF_INET6) 595 return -EINVAL; 596 597 if (optname == TCP_MD5SIG_EXT && 598 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { 599 prefixlen = cmd.tcpm_prefixlen; 600 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && 601 prefixlen > 32)) 602 return -EINVAL; 603 } else { 604 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; 605 } 606 607 if (optname == TCP_MD5SIG_EXT && 608 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { 609 struct net_device *dev; 610 611 rcu_read_lock(); 612 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); 613 if (dev && netif_is_l3_master(dev)) 614 l3index = dev->ifindex; 615 rcu_read_unlock(); 616 617 /* ok to reference set/not set outside of rcu; 618 * right now device MUST be an L3 master 619 */ 620 if (!dev || !l3index) 621 return -EINVAL; 622 } 623 624 if (!cmd.tcpm_keylen) { 625 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 626 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 627 AF_INET, prefixlen, 628 l3index); 629 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 630 AF_INET6, prefixlen, l3index); 631 } 632 633 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) 634 return -EINVAL; 635 636 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 637 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 638 AF_INET, prefixlen, l3index, 639 cmd.tcpm_key, cmd.tcpm_keylen, 640 GFP_KERNEL); 641 642 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 643 AF_INET6, prefixlen, l3index, 644 cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL); 645 } 646 647 static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp, 648 const struct in6_addr *daddr, 649 const struct in6_addr *saddr, 650 const struct tcphdr *th, int nbytes) 651 { 652 struct tcp6_pseudohdr *bp; 653 struct scatterlist sg; 654 struct tcphdr *_th; 655 656 bp = hp->scratch; 657 /* 1. TCP pseudo-header (RFC2460) */ 658 bp->saddr = *saddr; 659 bp->daddr = *daddr; 660 bp->protocol = cpu_to_be32(IPPROTO_TCP); 661 bp->len = cpu_to_be32(nbytes); 662 663 _th = (struct tcphdr *)(bp + 1); 664 memcpy(_th, th, sizeof(*th)); 665 _th->check = 0; 666 667 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); 668 ahash_request_set_crypt(hp->md5_req, &sg, NULL, 669 sizeof(*bp) + sizeof(*th)); 670 return crypto_ahash_update(hp->md5_req); 671 } 672 673 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, 674 const struct in6_addr *daddr, struct in6_addr *saddr, 675 const struct tcphdr *th) 676 { 677 struct tcp_md5sig_pool *hp; 678 struct ahash_request *req; 679 680 hp = tcp_get_md5sig_pool(); 681 if (!hp) 682 goto clear_hash_noput; 683 req = hp->md5_req; 684 685 if (crypto_ahash_init(req)) 686 goto clear_hash; 687 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) 688 goto clear_hash; 689 if (tcp_md5_hash_key(hp, key)) 690 goto clear_hash; 691 ahash_request_set_crypt(req, NULL, md5_hash, 0); 692 if (crypto_ahash_final(req)) 693 goto clear_hash; 694 695 tcp_put_md5sig_pool(); 696 return 0; 697 698 clear_hash: 699 tcp_put_md5sig_pool(); 700 clear_hash_noput: 701 memset(md5_hash, 0, 16); 702 return 1; 703 } 704 705 static int tcp_v6_md5_hash_skb(char *md5_hash, 706 const struct tcp_md5sig_key *key, 707 const struct sock *sk, 708 const struct sk_buff *skb) 709 { 710 const struct in6_addr *saddr, *daddr; 711 struct tcp_md5sig_pool *hp; 712 struct ahash_request *req; 713 const struct tcphdr *th = tcp_hdr(skb); 714 715 if (sk) { /* valid for establish/request sockets */ 716 saddr = &sk->sk_v6_rcv_saddr; 717 daddr = &sk->sk_v6_daddr; 718 } else { 719 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 720 saddr = &ip6h->saddr; 721 daddr = &ip6h->daddr; 722 } 723 724 hp = tcp_get_md5sig_pool(); 725 if (!hp) 726 goto clear_hash_noput; 727 req = hp->md5_req; 728 729 if (crypto_ahash_init(req)) 730 goto clear_hash; 731 732 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len)) 733 goto clear_hash; 734 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) 735 goto clear_hash; 736 if (tcp_md5_hash_key(hp, key)) 737 goto clear_hash; 738 ahash_request_set_crypt(req, NULL, md5_hash, 0); 739 if (crypto_ahash_final(req)) 740 goto clear_hash; 741 742 tcp_put_md5sig_pool(); 743 return 0; 744 745 clear_hash: 746 tcp_put_md5sig_pool(); 747 clear_hash_noput: 748 memset(md5_hash, 0, 16); 749 return 1; 750 } 751 752 #endif 753 754 static bool tcp_v6_inbound_md5_hash(const struct sock *sk, 755 const struct sk_buff *skb, 756 int dif, int sdif) 757 { 758 #ifdef CONFIG_TCP_MD5SIG 759 const __u8 *hash_location = NULL; 760 struct tcp_md5sig_key *hash_expected; 761 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 762 const struct tcphdr *th = tcp_hdr(skb); 763 int genhash, l3index; 764 u8 newhash[16]; 765 766 /* sdif set, means packet ingressed via a device 767 * in an L3 domain and dif is set to the l3mdev 768 */ 769 l3index = sdif ? dif : 0; 770 771 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index); 772 hash_location = tcp_parse_md5sig_option(th); 773 774 /* We've parsed the options - do we have a hash? */ 775 if (!hash_expected && !hash_location) 776 return false; 777 778 if (hash_expected && !hash_location) { 779 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); 780 return true; 781 } 782 783 if (!hash_expected && hash_location) { 784 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); 785 return true; 786 } 787 788 /* check the signature */ 789 genhash = tcp_v6_md5_hash_skb(newhash, 790 hash_expected, 791 NULL, skb); 792 793 if (genhash || memcmp(hash_location, newhash, 16) != 0) { 794 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); 795 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n", 796 genhash ? "failed" : "mismatch", 797 &ip6h->saddr, ntohs(th->source), 798 &ip6h->daddr, ntohs(th->dest), l3index); 799 return true; 800 } 801 #endif 802 return false; 803 } 804 805 static void tcp_v6_init_req(struct request_sock *req, 806 const struct sock *sk_listener, 807 struct sk_buff *skb) 808 { 809 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); 810 struct inet_request_sock *ireq = inet_rsk(req); 811 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener); 812 813 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 814 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 815 816 /* So that link locals have meaning */ 817 if ((!sk_listener->sk_bound_dev_if || l3_slave) && 818 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 819 ireq->ir_iif = tcp_v6_iif(skb); 820 821 if (!TCP_SKB_CB(skb)->tcp_tw_isn && 822 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) || 823 np->rxopt.bits.rxinfo || 824 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || 825 np->rxopt.bits.rxohlim || np->repflow)) { 826 refcount_inc(&skb->users); 827 ireq->pktopts = skb; 828 } 829 } 830 831 static struct dst_entry *tcp_v6_route_req(const struct sock *sk, 832 struct sk_buff *skb, 833 struct flowi *fl, 834 struct request_sock *req) 835 { 836 tcp_v6_init_req(req, sk, skb); 837 838 if (security_inet_conn_request(sk, skb, req)) 839 return NULL; 840 841 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP); 842 } 843 844 struct request_sock_ops tcp6_request_sock_ops __read_mostly = { 845 .family = AF_INET6, 846 .obj_size = sizeof(struct tcp6_request_sock), 847 .rtx_syn_ack = tcp_rtx_synack, 848 .send_ack = tcp_v6_reqsk_send_ack, 849 .destructor = tcp_v6_reqsk_destructor, 850 .send_reset = tcp_v6_send_reset, 851 .syn_ack_timeout = tcp_syn_ack_timeout, 852 }; 853 854 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { 855 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - 856 sizeof(struct ipv6hdr), 857 #ifdef CONFIG_TCP_MD5SIG 858 .req_md5_lookup = tcp_v6_md5_lookup, 859 .calc_md5_hash = tcp_v6_md5_hash_skb, 860 #endif 861 #ifdef CONFIG_SYN_COOKIES 862 .cookie_init_seq = cookie_v6_init_sequence, 863 #endif 864 .route_req = tcp_v6_route_req, 865 .init_seq = tcp_v6_init_seq, 866 .init_ts_off = tcp_v6_init_ts_off, 867 .send_synack = tcp_v6_send_synack, 868 }; 869 870 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, 871 u32 ack, u32 win, u32 tsval, u32 tsecr, 872 int oif, struct tcp_md5sig_key *key, int rst, 873 u8 tclass, __be32 label, u32 priority) 874 { 875 const struct tcphdr *th = tcp_hdr(skb); 876 struct tcphdr *t1; 877 struct sk_buff *buff; 878 struct flowi6 fl6; 879 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); 880 struct sock *ctl_sk = net->ipv6.tcp_sk; 881 unsigned int tot_len = sizeof(struct tcphdr); 882 struct dst_entry *dst; 883 __be32 *topt; 884 __u32 mark = 0; 885 886 if (tsecr) 887 tot_len += TCPOLEN_TSTAMP_ALIGNED; 888 #ifdef CONFIG_TCP_MD5SIG 889 if (key) 890 tot_len += TCPOLEN_MD5SIG_ALIGNED; 891 #endif 892 893 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len, 894 GFP_ATOMIC); 895 if (!buff) 896 return; 897 898 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len); 899 900 t1 = skb_push(buff, tot_len); 901 skb_reset_transport_header(buff); 902 903 /* Swap the send and the receive. */ 904 memset(t1, 0, sizeof(*t1)); 905 t1->dest = th->source; 906 t1->source = th->dest; 907 t1->doff = tot_len / 4; 908 t1->seq = htonl(seq); 909 t1->ack_seq = htonl(ack); 910 t1->ack = !rst || !th->ack; 911 t1->rst = rst; 912 t1->window = htons(win); 913 914 topt = (__be32 *)(t1 + 1); 915 916 if (tsecr) { 917 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 918 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); 919 *topt++ = htonl(tsval); 920 *topt++ = htonl(tsecr); 921 } 922 923 #ifdef CONFIG_TCP_MD5SIG 924 if (key) { 925 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 926 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); 927 tcp_v6_md5_hash_hdr((__u8 *)topt, key, 928 &ipv6_hdr(skb)->saddr, 929 &ipv6_hdr(skb)->daddr, t1); 930 } 931 #endif 932 933 memset(&fl6, 0, sizeof(fl6)); 934 fl6.daddr = ipv6_hdr(skb)->saddr; 935 fl6.saddr = ipv6_hdr(skb)->daddr; 936 fl6.flowlabel = label; 937 938 buff->ip_summed = CHECKSUM_PARTIAL; 939 buff->csum = 0; 940 941 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); 942 943 fl6.flowi6_proto = IPPROTO_TCP; 944 if (rt6_need_strict(&fl6.daddr) && !oif) 945 fl6.flowi6_oif = tcp_v6_iif(skb); 946 else { 947 if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) 948 oif = skb->skb_iif; 949 950 fl6.flowi6_oif = oif; 951 } 952 953 if (sk) { 954 if (sk->sk_state == TCP_TIME_WAIT) { 955 mark = inet_twsk(sk)->tw_mark; 956 /* autoflowlabel relies on buff->hash */ 957 skb_set_hash(buff, inet_twsk(sk)->tw_txhash, 958 PKT_HASH_TYPE_L4); 959 } else { 960 mark = sk->sk_mark; 961 } 962 buff->tstamp = tcp_transmit_time(sk); 963 } 964 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; 965 fl6.fl6_dport = t1->dest; 966 fl6.fl6_sport = t1->source; 967 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); 968 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); 969 970 /* Pass a socket to ip6_dst_lookup either it is for RST 971 * Underlying function will use this to retrieve the network 972 * namespace 973 */ 974 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL); 975 if (!IS_ERR(dst)) { 976 skb_dst_set(buff, dst); 977 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, 978 tclass & ~INET_ECN_MASK, priority); 979 TCP_INC_STATS(net, TCP_MIB_OUTSEGS); 980 if (rst) 981 TCP_INC_STATS(net, TCP_MIB_OUTRSTS); 982 return; 983 } 984 985 kfree_skb(buff); 986 } 987 988 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 989 { 990 const struct tcphdr *th = tcp_hdr(skb); 991 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 992 u32 seq = 0, ack_seq = 0; 993 struct tcp_md5sig_key *key = NULL; 994 #ifdef CONFIG_TCP_MD5SIG 995 const __u8 *hash_location = NULL; 996 unsigned char newhash[16]; 997 int genhash; 998 struct sock *sk1 = NULL; 999 #endif 1000 __be32 label = 0; 1001 u32 priority = 0; 1002 struct net *net; 1003 int oif = 0; 1004 1005 if (th->rst) 1006 return; 1007 1008 /* If sk not NULL, it means we did a successful lookup and incoming 1009 * route had to be correct. prequeue might have dropped our dst. 1010 */ 1011 if (!sk && !ipv6_unicast_destination(skb)) 1012 return; 1013 1014 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); 1015 #ifdef CONFIG_TCP_MD5SIG 1016 rcu_read_lock(); 1017 hash_location = tcp_parse_md5sig_option(th); 1018 if (sk && sk_fullsock(sk)) { 1019 int l3index; 1020 1021 /* sdif set, means packet ingressed via a device 1022 * in an L3 domain and inet_iif is set to it. 1023 */ 1024 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1025 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index); 1026 } else if (hash_location) { 1027 int dif = tcp_v6_iif_l3_slave(skb); 1028 int sdif = tcp_v6_sdif(skb); 1029 int l3index; 1030 1031 /* 1032 * active side is lost. Try to find listening socket through 1033 * source port, and then find md5 key through listening socket. 1034 * we are not loose security here: 1035 * Incoming packet is checked with md5 hash with finding key, 1036 * no RST generated if md5 hash doesn't match. 1037 */ 1038 sk1 = inet6_lookup_listener(net, 1039 &tcp_hashinfo, NULL, 0, 1040 &ipv6h->saddr, 1041 th->source, &ipv6h->daddr, 1042 ntohs(th->source), dif, sdif); 1043 if (!sk1) 1044 goto out; 1045 1046 /* sdif set, means packet ingressed via a device 1047 * in an L3 domain and dif is set to it. 1048 */ 1049 l3index = tcp_v6_sdif(skb) ? dif : 0; 1050 1051 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index); 1052 if (!key) 1053 goto out; 1054 1055 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb); 1056 if (genhash || memcmp(hash_location, newhash, 16) != 0) 1057 goto out; 1058 } 1059 #endif 1060 1061 if (th->ack) 1062 seq = ntohl(th->ack_seq); 1063 else 1064 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - 1065 (th->doff << 2); 1066 1067 if (sk) { 1068 oif = sk->sk_bound_dev_if; 1069 if (sk_fullsock(sk)) { 1070 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1071 1072 trace_tcp_send_reset(sk, skb); 1073 if (np->repflow) 1074 label = ip6_flowlabel(ipv6h); 1075 priority = sk->sk_priority; 1076 } 1077 if (sk->sk_state == TCP_TIME_WAIT) { 1078 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); 1079 priority = inet_twsk(sk)->tw_priority; 1080 } 1081 } else { 1082 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) 1083 label = ip6_flowlabel(ipv6h); 1084 } 1085 1086 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 1087 ipv6_get_dsfield(ipv6h), label, priority); 1088 1089 #ifdef CONFIG_TCP_MD5SIG 1090 out: 1091 rcu_read_unlock(); 1092 #endif 1093 } 1094 1095 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, 1096 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, 1097 struct tcp_md5sig_key *key, u8 tclass, 1098 __be32 label, u32 priority) 1099 { 1100 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0, 1101 tclass, label, priority); 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(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, 1110 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, 1111 tcp_time_stamp_raw() + tcptw->tw_ts_offset, 1112 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), 1113 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority); 1114 1115 inet_twsk_put(tw); 1116 } 1117 1118 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 1119 struct request_sock *req) 1120 { 1121 int l3index; 1122 1123 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1124 1125 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV 1126 * sk->sk_state == TCP_SYN_RECV -> for Fast Open. 1127 */ 1128 /* RFC 7323 2.3 1129 * The window field (SEG.WND) of every outgoing segment, with the 1130 * exception of <SYN> segments, MUST be right-shifted by 1131 * Rcv.Wind.Shift bits: 1132 */ 1133 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ? 1134 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, 1135 tcp_rsk(req)->rcv_nxt, 1136 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, 1137 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, 1138 req->ts_recent, sk->sk_bound_dev_if, 1139 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index), 1140 ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority); 1141 } 1142 1143 1144 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb) 1145 { 1146 #ifdef CONFIG_SYN_COOKIES 1147 const struct tcphdr *th = tcp_hdr(skb); 1148 1149 if (!th->syn) 1150 sk = cookie_v6_check(sk, skb); 1151 #endif 1152 return sk; 1153 } 1154 1155 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, 1156 struct tcphdr *th, u32 *cookie) 1157 { 1158 u16 mss = 0; 1159 #ifdef CONFIG_SYN_COOKIES 1160 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops, 1161 &tcp_request_sock_ipv6_ops, sk, th); 1162 if (mss) { 1163 *cookie = __cookie_v6_init_sequence(iph, th, &mss); 1164 tcp_synq_overflow(sk); 1165 } 1166 #endif 1167 return mss; 1168 } 1169 1170 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 1171 { 1172 if (skb->protocol == htons(ETH_P_IP)) 1173 return tcp_v4_conn_request(sk, skb); 1174 1175 if (!ipv6_unicast_destination(skb)) 1176 goto drop; 1177 1178 return tcp_conn_request(&tcp6_request_sock_ops, 1179 &tcp_request_sock_ipv6_ops, sk, skb); 1180 1181 drop: 1182 tcp_listendrop(sk); 1183 return 0; /* don't send reset */ 1184 } 1185 1186 static void tcp_v6_restore_cb(struct sk_buff *skb) 1187 { 1188 /* We need to move header back to the beginning if xfrm6_policy_check() 1189 * and tcp_v6_fill_cb() are going to be called again. 1190 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there. 1191 */ 1192 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6, 1193 sizeof(struct inet6_skb_parm)); 1194 } 1195 1196 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, 1197 struct request_sock *req, 1198 struct dst_entry *dst, 1199 struct request_sock *req_unhash, 1200 bool *own_req) 1201 { 1202 struct inet_request_sock *ireq; 1203 struct ipv6_pinfo *newnp; 1204 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1205 struct ipv6_txoptions *opt; 1206 struct inet_sock *newinet; 1207 bool found_dup_sk = false; 1208 struct tcp_sock *newtp; 1209 struct sock *newsk; 1210 #ifdef CONFIG_TCP_MD5SIG 1211 struct tcp_md5sig_key *key; 1212 int l3index; 1213 #endif 1214 struct flowi6 fl6; 1215 1216 if (skb->protocol == htons(ETH_P_IP)) { 1217 /* 1218 * v6 mapped 1219 */ 1220 1221 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst, 1222 req_unhash, own_req); 1223 1224 if (!newsk) 1225 return NULL; 1226 1227 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1228 1229 newinet = inet_sk(newsk); 1230 newnp = tcp_inet6_sk(newsk); 1231 newtp = tcp_sk(newsk); 1232 1233 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1234 1235 newnp->saddr = newsk->sk_v6_rcv_saddr; 1236 1237 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; 1238 if (sk_is_mptcp(newsk)) 1239 mptcpv6_handle_mapped(newsk, true); 1240 newsk->sk_backlog_rcv = tcp_v4_do_rcv; 1241 #ifdef CONFIG_TCP_MD5SIG 1242 newtp->af_specific = &tcp_sock_ipv6_mapped_specific; 1243 #endif 1244 1245 newnp->ipv6_mc_list = NULL; 1246 newnp->ipv6_ac_list = NULL; 1247 newnp->ipv6_fl_list = NULL; 1248 newnp->pktoptions = NULL; 1249 newnp->opt = NULL; 1250 newnp->mcast_oif = inet_iif(skb); 1251 newnp->mcast_hops = ip_hdr(skb)->ttl; 1252 newnp->rcv_flowinfo = 0; 1253 if (np->repflow) 1254 newnp->flow_label = 0; 1255 1256 /* 1257 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 1258 * here, tcp_create_openreq_child now does this for us, see the comment in 1259 * that function for the gory details. -acme 1260 */ 1261 1262 /* It is tricky place. Until this moment IPv4 tcp 1263 worked with IPv6 icsk.icsk_af_ops. 1264 Sync it now. 1265 */ 1266 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 1267 1268 return newsk; 1269 } 1270 1271 ireq = inet_rsk(req); 1272 1273 if (sk_acceptq_is_full(sk)) 1274 goto out_overflow; 1275 1276 if (!dst) { 1277 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP); 1278 if (!dst) 1279 goto out; 1280 } 1281 1282 newsk = tcp_create_openreq_child(sk, req, skb); 1283 if (!newsk) 1284 goto out_nonewsk; 1285 1286 /* 1287 * No need to charge this sock to the relevant IPv6 refcnt debug socks 1288 * count here, tcp_create_openreq_child now does this for us, see the 1289 * comment in that function for the gory details. -acme 1290 */ 1291 1292 newsk->sk_gso_type = SKB_GSO_TCPV6; 1293 ip6_dst_store(newsk, dst, NULL, NULL); 1294 inet6_sk_rx_dst_set(newsk, skb); 1295 1296 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1297 1298 newtp = tcp_sk(newsk); 1299 newinet = inet_sk(newsk); 1300 newnp = tcp_inet6_sk(newsk); 1301 1302 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1303 1304 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 1305 newnp->saddr = ireq->ir_v6_loc_addr; 1306 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 1307 newsk->sk_bound_dev_if = ireq->ir_iif; 1308 1309 /* Now IPv6 options... 1310 1311 First: no IPv4 options. 1312 */ 1313 newinet->inet_opt = NULL; 1314 newnp->ipv6_mc_list = NULL; 1315 newnp->ipv6_ac_list = NULL; 1316 newnp->ipv6_fl_list = NULL; 1317 1318 /* Clone RX bits */ 1319 newnp->rxopt.all = np->rxopt.all; 1320 1321 newnp->pktoptions = NULL; 1322 newnp->opt = NULL; 1323 newnp->mcast_oif = tcp_v6_iif(skb); 1324 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1325 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb)); 1326 if (np->repflow) 1327 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); 1328 1329 /* Set ToS of the new socket based upon the value of incoming SYN. 1330 * ECT bits are set later in tcp_init_transfer(). 1331 */ 1332 if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) 1333 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; 1334 1335 /* Clone native IPv6 options from listening socket (if any) 1336 1337 Yes, keeping reference count would be much more clever, 1338 but we make one more one thing there: reattach optmem 1339 to newsk. 1340 */ 1341 opt = ireq->ipv6_opt; 1342 if (!opt) 1343 opt = rcu_dereference(np->opt); 1344 if (opt) { 1345 opt = ipv6_dup_options(newsk, opt); 1346 RCU_INIT_POINTER(newnp->opt, opt); 1347 } 1348 inet_csk(newsk)->icsk_ext_hdr_len = 0; 1349 if (opt) 1350 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + 1351 opt->opt_flen; 1352 1353 tcp_ca_openreq_child(newsk, dst); 1354 1355 tcp_sync_mss(newsk, dst_mtu(dst)); 1356 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); 1357 1358 tcp_initialize_rcv_mss(newsk); 1359 1360 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 1361 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 1362 1363 #ifdef CONFIG_TCP_MD5SIG 1364 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); 1365 1366 /* Copy over the MD5 key from the original socket */ 1367 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index); 1368 if (key) { 1369 /* We're using one, so create a matching key 1370 * on the newsk structure. If we fail to get 1371 * memory, then we end up not copying the key 1372 * across. Shucks. 1373 */ 1374 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr, 1375 AF_INET6, 128, l3index, key->key, key->keylen, 1376 sk_gfp_mask(sk, GFP_ATOMIC)); 1377 } 1378 #endif 1379 1380 if (__inet_inherit_port(sk, newsk) < 0) { 1381 inet_csk_prepare_forced_close(newsk); 1382 tcp_done(newsk); 1383 goto out; 1384 } 1385 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), 1386 &found_dup_sk); 1387 if (*own_req) { 1388 tcp_move_syn(newtp, req); 1389 1390 /* Clone pktoptions received with SYN, if we own the req */ 1391 if (ireq->pktopts) { 1392 newnp->pktoptions = skb_clone(ireq->pktopts, 1393 sk_gfp_mask(sk, GFP_ATOMIC)); 1394 consume_skb(ireq->pktopts); 1395 ireq->pktopts = NULL; 1396 if (newnp->pktoptions) { 1397 tcp_v6_restore_cb(newnp->pktoptions); 1398 skb_set_owner_r(newnp->pktoptions, newsk); 1399 } 1400 } 1401 } else { 1402 if (!req_unhash && found_dup_sk) { 1403 /* This code path should only be executed in the 1404 * syncookie case only 1405 */ 1406 bh_unlock_sock(newsk); 1407 sock_put(newsk); 1408 newsk = NULL; 1409 } 1410 } 1411 1412 return newsk; 1413 1414 out_overflow: 1415 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 1416 out_nonewsk: 1417 dst_release(dst); 1418 out: 1419 tcp_listendrop(sk); 1420 return NULL; 1421 } 1422 1423 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, 1424 u32)); 1425 /* The socket must have it's spinlock held when we get 1426 * here, unless it is a TCP_LISTEN socket. 1427 * 1428 * We have a potential double-lock case here, so even when 1429 * doing backlog processing we use the BH locking scheme. 1430 * This is because we cannot sleep with the original spinlock 1431 * held. 1432 */ 1433 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 1434 { 1435 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1436 struct sk_buff *opt_skb = NULL; 1437 struct tcp_sock *tp; 1438 1439 /* Imagine: socket is IPv6. IPv4 packet arrives, 1440 goes to IPv4 receive handler and backlogged. 1441 From backlog it always goes here. Kerboom... 1442 Fortunately, tcp_rcv_established and rcv_established 1443 handle them correctly, but it is not case with 1444 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK 1445 */ 1446 1447 if (skb->protocol == htons(ETH_P_IP)) 1448 return tcp_v4_do_rcv(sk, skb); 1449 1450 /* 1451 * socket locking is here for SMP purposes as backlog rcv 1452 * is currently called with bh processing disabled. 1453 */ 1454 1455 /* Do Stevens' IPV6_PKTOPTIONS. 1456 1457 Yes, guys, it is the only place in our code, where we 1458 may make it not affecting IPv4. 1459 The rest of code is protocol independent, 1460 and I do not like idea to uglify IPv4. 1461 1462 Actually, all the idea behind IPV6_PKTOPTIONS 1463 looks not very well thought. For now we latch 1464 options, received in the last packet, enqueued 1465 by tcp. Feel free to propose better solution. 1466 --ANK (980728) 1467 */ 1468 if (np->rxopt.all) 1469 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC)); 1470 1471 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ 1472 struct dst_entry *dst = sk->sk_rx_dst; 1473 1474 sock_rps_save_rxhash(sk, skb); 1475 sk_mark_napi_id(sk, skb); 1476 if (dst) { 1477 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || 1478 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check, 1479 dst, np->rx_dst_cookie) == NULL) { 1480 dst_release(dst); 1481 sk->sk_rx_dst = NULL; 1482 } 1483 } 1484 1485 tcp_rcv_established(sk, skb); 1486 if (opt_skb) 1487 goto ipv6_pktoptions; 1488 return 0; 1489 } 1490 1491 if (tcp_checksum_complete(skb)) 1492 goto csum_err; 1493 1494 if (sk->sk_state == TCP_LISTEN) { 1495 struct sock *nsk = tcp_v6_cookie_check(sk, skb); 1496 1497 if (!nsk) 1498 goto discard; 1499 1500 if (nsk != sk) { 1501 if (tcp_child_process(sk, nsk, skb)) 1502 goto reset; 1503 if (opt_skb) 1504 __kfree_skb(opt_skb); 1505 return 0; 1506 } 1507 } else 1508 sock_rps_save_rxhash(sk, skb); 1509 1510 if (tcp_rcv_state_process(sk, skb)) 1511 goto reset; 1512 if (opt_skb) 1513 goto ipv6_pktoptions; 1514 return 0; 1515 1516 reset: 1517 tcp_v6_send_reset(sk, skb); 1518 discard: 1519 if (opt_skb) 1520 __kfree_skb(opt_skb); 1521 kfree_skb(skb); 1522 return 0; 1523 csum_err: 1524 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); 1525 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); 1526 goto discard; 1527 1528 1529 ipv6_pktoptions: 1530 /* Do you ask, what is it? 1531 1532 1. skb was enqueued by tcp. 1533 2. skb is added to tail of read queue, rather than out of order. 1534 3. socket is not in passive state. 1535 4. Finally, it really contains options, which user wants to receive. 1536 */ 1537 tp = tcp_sk(sk); 1538 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && 1539 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { 1540 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) 1541 np->mcast_oif = tcp_v6_iif(opt_skb); 1542 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) 1543 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; 1544 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) 1545 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); 1546 if (np->repflow) 1547 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); 1548 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { 1549 skb_set_owner_r(opt_skb, sk); 1550 tcp_v6_restore_cb(opt_skb); 1551 opt_skb = xchg(&np->pktoptions, opt_skb); 1552 } else { 1553 __kfree_skb(opt_skb); 1554 opt_skb = xchg(&np->pktoptions, NULL); 1555 } 1556 } 1557 1558 kfree_skb(opt_skb); 1559 return 0; 1560 } 1561 1562 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, 1563 const struct tcphdr *th) 1564 { 1565 /* This is tricky: we move IP6CB at its correct location into 1566 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because 1567 * _decode_session6() uses IP6CB(). 1568 * barrier() makes sure compiler won't play aliasing games. 1569 */ 1570 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), 1571 sizeof(struct inet6_skb_parm)); 1572 barrier(); 1573 1574 TCP_SKB_CB(skb)->seq = ntohl(th->seq); 1575 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + 1576 skb->len - th->doff*4); 1577 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); 1578 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); 1579 TCP_SKB_CB(skb)->tcp_tw_isn = 0; 1580 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); 1581 TCP_SKB_CB(skb)->sacked = 0; 1582 TCP_SKB_CB(skb)->has_rxtstamp = 1583 skb->tstamp || skb_hwtstamps(skb)->hwtstamp; 1584 } 1585 1586 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) 1587 { 1588 struct sk_buff *skb_to_free; 1589 int sdif = inet6_sdif(skb); 1590 int dif = inet6_iif(skb); 1591 const struct tcphdr *th; 1592 const struct ipv6hdr *hdr; 1593 bool refcounted; 1594 struct sock *sk; 1595 int ret; 1596 struct net *net = dev_net(skb->dev); 1597 1598 if (skb->pkt_type != PACKET_HOST) 1599 goto discard_it; 1600 1601 /* 1602 * Count it even if it's bad. 1603 */ 1604 __TCP_INC_STATS(net, TCP_MIB_INSEGS); 1605 1606 if (!pskb_may_pull(skb, sizeof(struct tcphdr))) 1607 goto discard_it; 1608 1609 th = (const struct tcphdr *)skb->data; 1610 1611 if (unlikely(th->doff < sizeof(struct tcphdr)/4)) 1612 goto bad_packet; 1613 if (!pskb_may_pull(skb, th->doff*4)) 1614 goto discard_it; 1615 1616 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo)) 1617 goto csum_error; 1618 1619 th = (const struct tcphdr *)skb->data; 1620 hdr = ipv6_hdr(skb); 1621 1622 lookup: 1623 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), 1624 th->source, th->dest, inet6_iif(skb), sdif, 1625 &refcounted); 1626 if (!sk) 1627 goto no_tcp_socket; 1628 1629 process: 1630 if (sk->sk_state == TCP_TIME_WAIT) 1631 goto do_time_wait; 1632 1633 if (sk->sk_state == TCP_NEW_SYN_RECV) { 1634 struct request_sock *req = inet_reqsk(sk); 1635 bool req_stolen = false; 1636 struct sock *nsk; 1637 1638 sk = req->rsk_listener; 1639 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) { 1640 sk_drops_add(sk, skb); 1641 reqsk_put(req); 1642 goto discard_it; 1643 } 1644 if (tcp_checksum_complete(skb)) { 1645 reqsk_put(req); 1646 goto csum_error; 1647 } 1648 if (unlikely(sk->sk_state != TCP_LISTEN)) { 1649 inet_csk_reqsk_queue_drop_and_put(sk, req); 1650 goto lookup; 1651 } 1652 sock_hold(sk); 1653 refcounted = true; 1654 nsk = NULL; 1655 if (!tcp_filter(sk, skb)) { 1656 th = (const struct tcphdr *)skb->data; 1657 hdr = ipv6_hdr(skb); 1658 tcp_v6_fill_cb(skb, hdr, th); 1659 nsk = tcp_check_req(sk, skb, req, false, &req_stolen); 1660 } 1661 if (!nsk) { 1662 reqsk_put(req); 1663 if (req_stolen) { 1664 /* Another cpu got exclusive access to req 1665 * and created a full blown socket. 1666 * Try to feed this packet to this socket 1667 * instead of discarding it. 1668 */ 1669 tcp_v6_restore_cb(skb); 1670 sock_put(sk); 1671 goto lookup; 1672 } 1673 goto discard_and_relse; 1674 } 1675 if (nsk == sk) { 1676 reqsk_put(req); 1677 tcp_v6_restore_cb(skb); 1678 } else if (tcp_child_process(sk, nsk, skb)) { 1679 tcp_v6_send_reset(nsk, skb); 1680 goto discard_and_relse; 1681 } else { 1682 sock_put(sk); 1683 return 0; 1684 } 1685 } 1686 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) { 1687 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 1688 goto discard_and_relse; 1689 } 1690 1691 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 1692 goto discard_and_relse; 1693 1694 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) 1695 goto discard_and_relse; 1696 1697 if (tcp_filter(sk, skb)) 1698 goto discard_and_relse; 1699 th = (const struct tcphdr *)skb->data; 1700 hdr = ipv6_hdr(skb); 1701 tcp_v6_fill_cb(skb, hdr, th); 1702 1703 skb->dev = NULL; 1704 1705 if (sk->sk_state == TCP_LISTEN) { 1706 ret = tcp_v6_do_rcv(sk, skb); 1707 goto put_and_return; 1708 } 1709 1710 sk_incoming_cpu_update(sk); 1711 1712 bh_lock_sock_nested(sk); 1713 tcp_segs_in(tcp_sk(sk), skb); 1714 ret = 0; 1715 if (!sock_owned_by_user(sk)) { 1716 skb_to_free = sk->sk_rx_skb_cache; 1717 sk->sk_rx_skb_cache = NULL; 1718 ret = tcp_v6_do_rcv(sk, skb); 1719 } else { 1720 if (tcp_add_backlog(sk, skb)) 1721 goto discard_and_relse; 1722 skb_to_free = NULL; 1723 } 1724 bh_unlock_sock(sk); 1725 if (skb_to_free) 1726 __kfree_skb(skb_to_free); 1727 put_and_return: 1728 if (refcounted) 1729 sock_put(sk); 1730 return ret ? -1 : 0; 1731 1732 no_tcp_socket: 1733 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 1734 goto discard_it; 1735 1736 tcp_v6_fill_cb(skb, hdr, th); 1737 1738 if (tcp_checksum_complete(skb)) { 1739 csum_error: 1740 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); 1741 bad_packet: 1742 __TCP_INC_STATS(net, TCP_MIB_INERRS); 1743 } else { 1744 tcp_v6_send_reset(NULL, skb); 1745 } 1746 1747 discard_it: 1748 kfree_skb(skb); 1749 return 0; 1750 1751 discard_and_relse: 1752 sk_drops_add(sk, skb); 1753 if (refcounted) 1754 sock_put(sk); 1755 goto discard_it; 1756 1757 do_time_wait: 1758 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1759 inet_twsk_put(inet_twsk(sk)); 1760 goto discard_it; 1761 } 1762 1763 tcp_v6_fill_cb(skb, hdr, th); 1764 1765 if (tcp_checksum_complete(skb)) { 1766 inet_twsk_put(inet_twsk(sk)); 1767 goto csum_error; 1768 } 1769 1770 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { 1771 case TCP_TW_SYN: 1772 { 1773 struct sock *sk2; 1774 1775 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, 1776 skb, __tcp_hdrlen(th), 1777 &ipv6_hdr(skb)->saddr, th->source, 1778 &ipv6_hdr(skb)->daddr, 1779 ntohs(th->dest), 1780 tcp_v6_iif_l3_slave(skb), 1781 sdif); 1782 if (sk2) { 1783 struct inet_timewait_sock *tw = inet_twsk(sk); 1784 inet_twsk_deschedule_put(tw); 1785 sk = sk2; 1786 tcp_v6_restore_cb(skb); 1787 refcounted = false; 1788 goto process; 1789 } 1790 } 1791 /* to ACK */ 1792 fallthrough; 1793 case TCP_TW_ACK: 1794 tcp_v6_timewait_ack(sk, skb); 1795 break; 1796 case TCP_TW_RST: 1797 tcp_v6_send_reset(sk, skb); 1798 inet_twsk_deschedule_put(inet_twsk(sk)); 1799 goto discard_it; 1800 case TCP_TW_SUCCESS: 1801 ; 1802 } 1803 goto discard_it; 1804 } 1805 1806 INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb) 1807 { 1808 const struct ipv6hdr *hdr; 1809 const struct tcphdr *th; 1810 struct sock *sk; 1811 1812 if (skb->pkt_type != PACKET_HOST) 1813 return; 1814 1815 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) 1816 return; 1817 1818 hdr = ipv6_hdr(skb); 1819 th = tcp_hdr(skb); 1820 1821 if (th->doff < sizeof(struct tcphdr) / 4) 1822 return; 1823 1824 /* Note : We use inet6_iif() here, not tcp_v6_iif() */ 1825 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo, 1826 &hdr->saddr, th->source, 1827 &hdr->daddr, ntohs(th->dest), 1828 inet6_iif(skb), inet6_sdif(skb)); 1829 if (sk) { 1830 skb->sk = sk; 1831 skb->destructor = sock_edemux; 1832 if (sk_fullsock(sk)) { 1833 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst); 1834 1835 if (dst) 1836 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie); 1837 if (dst && 1838 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif) 1839 skb_dst_set_noref(skb, dst); 1840 } 1841 } 1842 } 1843 1844 static struct timewait_sock_ops tcp6_timewait_sock_ops = { 1845 .twsk_obj_size = sizeof(struct tcp6_timewait_sock), 1846 .twsk_unique = tcp_twsk_unique, 1847 .twsk_destructor = tcp_twsk_destructor, 1848 }; 1849 1850 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) 1851 { 1852 struct ipv6_pinfo *np = inet6_sk(sk); 1853 1854 __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr); 1855 } 1856 1857 const struct inet_connection_sock_af_ops ipv6_specific = { 1858 .queue_xmit = inet6_csk_xmit, 1859 .send_check = tcp_v6_send_check, 1860 .rebuild_header = inet6_sk_rebuild_header, 1861 .sk_rx_dst_set = inet6_sk_rx_dst_set, 1862 .conn_request = tcp_v6_conn_request, 1863 .syn_recv_sock = tcp_v6_syn_recv_sock, 1864 .net_header_len = sizeof(struct ipv6hdr), 1865 .net_frag_header_len = sizeof(struct frag_hdr), 1866 .setsockopt = ipv6_setsockopt, 1867 .getsockopt = ipv6_getsockopt, 1868 .addr2sockaddr = inet6_csk_addr2sockaddr, 1869 .sockaddr_len = sizeof(struct sockaddr_in6), 1870 .mtu_reduced = tcp_v6_mtu_reduced, 1871 }; 1872 1873 #ifdef CONFIG_TCP_MD5SIG 1874 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { 1875 .md5_lookup = tcp_v6_md5_lookup, 1876 .calc_md5_hash = tcp_v6_md5_hash_skb, 1877 .md5_parse = tcp_v6_parse_md5_keys, 1878 }; 1879 #endif 1880 1881 /* 1882 * TCP over IPv4 via INET6 API 1883 */ 1884 static const struct inet_connection_sock_af_ops ipv6_mapped = { 1885 .queue_xmit = ip_queue_xmit, 1886 .send_check = tcp_v4_send_check, 1887 .rebuild_header = inet_sk_rebuild_header, 1888 .sk_rx_dst_set = inet_sk_rx_dst_set, 1889 .conn_request = tcp_v6_conn_request, 1890 .syn_recv_sock = tcp_v6_syn_recv_sock, 1891 .net_header_len = sizeof(struct iphdr), 1892 .setsockopt = ipv6_setsockopt, 1893 .getsockopt = ipv6_getsockopt, 1894 .addr2sockaddr = inet6_csk_addr2sockaddr, 1895 .sockaddr_len = sizeof(struct sockaddr_in6), 1896 .mtu_reduced = tcp_v4_mtu_reduced, 1897 }; 1898 1899 #ifdef CONFIG_TCP_MD5SIG 1900 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { 1901 .md5_lookup = tcp_v4_md5_lookup, 1902 .calc_md5_hash = tcp_v4_md5_hash_skb, 1903 .md5_parse = tcp_v6_parse_md5_keys, 1904 }; 1905 #endif 1906 1907 /* NOTE: A lot of things set to zero explicitly by call to 1908 * sk_alloc() so need not be done here. 1909 */ 1910 static int tcp_v6_init_sock(struct sock *sk) 1911 { 1912 struct inet_connection_sock *icsk = inet_csk(sk); 1913 1914 tcp_init_sock(sk); 1915 1916 icsk->icsk_af_ops = &ipv6_specific; 1917 1918 #ifdef CONFIG_TCP_MD5SIG 1919 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; 1920 #endif 1921 1922 return 0; 1923 } 1924 1925 static void tcp_v6_destroy_sock(struct sock *sk) 1926 { 1927 tcp_v4_destroy_sock(sk); 1928 inet6_destroy_sock(sk); 1929 } 1930 1931 #ifdef CONFIG_PROC_FS 1932 /* Proc filesystem TCPv6 sock list dumping. */ 1933 static void get_openreq6(struct seq_file *seq, 1934 const struct request_sock *req, int i) 1935 { 1936 long ttd = req->rsk_timer.expires - jiffies; 1937 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr; 1938 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr; 1939 1940 if (ttd < 0) 1941 ttd = 0; 1942 1943 seq_printf(seq, 1944 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 1945 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n", 1946 i, 1947 src->s6_addr32[0], src->s6_addr32[1], 1948 src->s6_addr32[2], src->s6_addr32[3], 1949 inet_rsk(req)->ir_num, 1950 dest->s6_addr32[0], dest->s6_addr32[1], 1951 dest->s6_addr32[2], dest->s6_addr32[3], 1952 ntohs(inet_rsk(req)->ir_rmt_port), 1953 TCP_SYN_RECV, 1954 0, 0, /* could print option size, but that is af dependent. */ 1955 1, /* timers active (only the expire timer) */ 1956 jiffies_to_clock_t(ttd), 1957 req->num_timeout, 1958 from_kuid_munged(seq_user_ns(seq), 1959 sock_i_uid(req->rsk_listener)), 1960 0, /* non standard timer */ 1961 0, /* open_requests have no inode */ 1962 0, req); 1963 } 1964 1965 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 1966 { 1967 const struct in6_addr *dest, *src; 1968 __u16 destp, srcp; 1969 int timer_active; 1970 unsigned long timer_expires; 1971 const struct inet_sock *inet = inet_sk(sp); 1972 const struct tcp_sock *tp = tcp_sk(sp); 1973 const struct inet_connection_sock *icsk = inet_csk(sp); 1974 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; 1975 int rx_queue; 1976 int state; 1977 1978 dest = &sp->sk_v6_daddr; 1979 src = &sp->sk_v6_rcv_saddr; 1980 destp = ntohs(inet->inet_dport); 1981 srcp = ntohs(inet->inet_sport); 1982 1983 if (icsk->icsk_pending == ICSK_TIME_RETRANS || 1984 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || 1985 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { 1986 timer_active = 1; 1987 timer_expires = icsk->icsk_timeout; 1988 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 1989 timer_active = 4; 1990 timer_expires = icsk->icsk_timeout; 1991 } else if (timer_pending(&sp->sk_timer)) { 1992 timer_active = 2; 1993 timer_expires = sp->sk_timer.expires; 1994 } else { 1995 timer_active = 0; 1996 timer_expires = jiffies; 1997 } 1998 1999 state = inet_sk_state_load(sp); 2000 if (state == TCP_LISTEN) 2001 rx_queue = READ_ONCE(sp->sk_ack_backlog); 2002 else 2003 /* Because we don't lock the socket, 2004 * we might find a transient negative value. 2005 */ 2006 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - 2007 READ_ONCE(tp->copied_seq), 0); 2008 2009 seq_printf(seq, 2010 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2011 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n", 2012 i, 2013 src->s6_addr32[0], src->s6_addr32[1], 2014 src->s6_addr32[2], src->s6_addr32[3], srcp, 2015 dest->s6_addr32[0], dest->s6_addr32[1], 2016 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2017 state, 2018 READ_ONCE(tp->write_seq) - tp->snd_una, 2019 rx_queue, 2020 timer_active, 2021 jiffies_delta_to_clock_t(timer_expires - jiffies), 2022 icsk->icsk_retransmits, 2023 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), 2024 icsk->icsk_probes_out, 2025 sock_i_ino(sp), 2026 refcount_read(&sp->sk_refcnt), sp, 2027 jiffies_to_clock_t(icsk->icsk_rto), 2028 jiffies_to_clock_t(icsk->icsk_ack.ato), 2029 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), 2030 tp->snd_cwnd, 2031 state == TCP_LISTEN ? 2032 fastopenq->max_qlen : 2033 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) 2034 ); 2035 } 2036 2037 static void get_timewait6_sock(struct seq_file *seq, 2038 struct inet_timewait_sock *tw, int i) 2039 { 2040 long delta = tw->tw_timer.expires - jiffies; 2041 const struct in6_addr *dest, *src; 2042 __u16 destp, srcp; 2043 2044 dest = &tw->tw_v6_daddr; 2045 src = &tw->tw_v6_rcv_saddr; 2046 destp = ntohs(tw->tw_dport); 2047 srcp = ntohs(tw->tw_sport); 2048 2049 seq_printf(seq, 2050 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2051 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 2052 i, 2053 src->s6_addr32[0], src->s6_addr32[1], 2054 src->s6_addr32[2], src->s6_addr32[3], srcp, 2055 dest->s6_addr32[0], dest->s6_addr32[1], 2056 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2057 tw->tw_substate, 0, 0, 2058 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, 2059 refcount_read(&tw->tw_refcnt), tw); 2060 } 2061 2062 static int tcp6_seq_show(struct seq_file *seq, void *v) 2063 { 2064 struct tcp_iter_state *st; 2065 struct sock *sk = v; 2066 2067 if (v == SEQ_START_TOKEN) { 2068 seq_puts(seq, 2069 " sl " 2070 "local_address " 2071 "remote_address " 2072 "st tx_queue rx_queue tr tm->when retrnsmt" 2073 " uid timeout inode\n"); 2074 goto out; 2075 } 2076 st = seq->private; 2077 2078 if (sk->sk_state == TCP_TIME_WAIT) 2079 get_timewait6_sock(seq, v, st->num); 2080 else if (sk->sk_state == TCP_NEW_SYN_RECV) 2081 get_openreq6(seq, v, st->num); 2082 else 2083 get_tcp6_sock(seq, v, st->num); 2084 out: 2085 return 0; 2086 } 2087 2088 static const struct seq_operations tcp6_seq_ops = { 2089 .show = tcp6_seq_show, 2090 .start = tcp_seq_start, 2091 .next = tcp_seq_next, 2092 .stop = tcp_seq_stop, 2093 }; 2094 2095 static struct tcp_seq_afinfo tcp6_seq_afinfo = { 2096 .family = AF_INET6, 2097 }; 2098 2099 int __net_init tcp6_proc_init(struct net *net) 2100 { 2101 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops, 2102 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo)) 2103 return -ENOMEM; 2104 return 0; 2105 } 2106 2107 void tcp6_proc_exit(struct net *net) 2108 { 2109 remove_proc_entry("tcp6", net->proc_net); 2110 } 2111 #endif 2112 2113 struct proto tcpv6_prot = { 2114 .name = "TCPv6", 2115 .owner = THIS_MODULE, 2116 .close = tcp_close, 2117 .pre_connect = tcp_v6_pre_connect, 2118 .connect = tcp_v6_connect, 2119 .disconnect = tcp_disconnect, 2120 .accept = inet_csk_accept, 2121 .ioctl = tcp_ioctl, 2122 .init = tcp_v6_init_sock, 2123 .destroy = tcp_v6_destroy_sock, 2124 .shutdown = tcp_shutdown, 2125 .setsockopt = tcp_setsockopt, 2126 .getsockopt = tcp_getsockopt, 2127 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, 2128 .keepalive = tcp_set_keepalive, 2129 .recvmsg = tcp_recvmsg, 2130 .sendmsg = tcp_sendmsg, 2131 .sendpage = tcp_sendpage, 2132 .backlog_rcv = tcp_v6_do_rcv, 2133 .release_cb = tcp_release_cb, 2134 .hash = inet6_hash, 2135 .unhash = inet_unhash, 2136 .get_port = inet_csk_get_port, 2137 .enter_memory_pressure = tcp_enter_memory_pressure, 2138 .leave_memory_pressure = tcp_leave_memory_pressure, 2139 .stream_memory_free = tcp_stream_memory_free, 2140 .sockets_allocated = &tcp_sockets_allocated, 2141 .memory_allocated = &tcp_memory_allocated, 2142 .memory_pressure = &tcp_memory_pressure, 2143 .orphan_count = &tcp_orphan_count, 2144 .sysctl_mem = sysctl_tcp_mem, 2145 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), 2146 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), 2147 .max_header = MAX_TCP_HEADER, 2148 .obj_size = sizeof(struct tcp6_sock), 2149 .slab_flags = SLAB_TYPESAFE_BY_RCU, 2150 .twsk_prot = &tcp6_timewait_sock_ops, 2151 .rsk_prot = &tcp6_request_sock_ops, 2152 .h.hashinfo = &tcp_hashinfo, 2153 .no_autobind = true, 2154 .diag_destroy = tcp_abort, 2155 }; 2156 EXPORT_SYMBOL_GPL(tcpv6_prot); 2157 2158 /* thinking of making this const? Don't. 2159 * early_demux can change based on sysctl. 2160 */ 2161 static struct inet6_protocol tcpv6_protocol = { 2162 .early_demux = tcp_v6_early_demux, 2163 .early_demux_handler = tcp_v6_early_demux, 2164 .handler = tcp_v6_rcv, 2165 .err_handler = tcp_v6_err, 2166 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 2167 }; 2168 2169 static struct inet_protosw tcpv6_protosw = { 2170 .type = SOCK_STREAM, 2171 .protocol = IPPROTO_TCP, 2172 .prot = &tcpv6_prot, 2173 .ops = &inet6_stream_ops, 2174 .flags = INET_PROTOSW_PERMANENT | 2175 INET_PROTOSW_ICSK, 2176 }; 2177 2178 static int __net_init tcpv6_net_init(struct net *net) 2179 { 2180 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, 2181 SOCK_RAW, IPPROTO_TCP, net); 2182 } 2183 2184 static void __net_exit tcpv6_net_exit(struct net *net) 2185 { 2186 inet_ctl_sock_destroy(net->ipv6.tcp_sk); 2187 } 2188 2189 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) 2190 { 2191 inet_twsk_purge(&tcp_hashinfo, AF_INET6); 2192 } 2193 2194 static struct pernet_operations tcpv6_net_ops = { 2195 .init = tcpv6_net_init, 2196 .exit = tcpv6_net_exit, 2197 .exit_batch = tcpv6_net_exit_batch, 2198 }; 2199 2200 int __init tcpv6_init(void) 2201 { 2202 int ret; 2203 2204 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); 2205 if (ret) 2206 goto out; 2207 2208 /* register inet6 protocol */ 2209 ret = inet6_register_protosw(&tcpv6_protosw); 2210 if (ret) 2211 goto out_tcpv6_protocol; 2212 2213 ret = register_pernet_subsys(&tcpv6_net_ops); 2214 if (ret) 2215 goto out_tcpv6_protosw; 2216 2217 ret = mptcpv6_init(); 2218 if (ret) 2219 goto out_tcpv6_pernet_subsys; 2220 2221 out: 2222 return ret; 2223 2224 out_tcpv6_pernet_subsys: 2225 unregister_pernet_subsys(&tcpv6_net_ops); 2226 out_tcpv6_protosw: 2227 inet6_unregister_protosw(&tcpv6_protosw); 2228 out_tcpv6_protocol: 2229 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2230 goto out; 2231 } 2232 2233 void tcpv6_exit(void) 2234 { 2235 unregister_pernet_subsys(&tcpv6_net_ops); 2236 inet6_unregister_protosw(&tcpv6_protosw); 2237 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2238 } 2239