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/hotdata.h> 62 #include <net/busy_poll.h> 63 #include <net/rstreason.h> 64 65 #include <linux/proc_fs.h> 66 #include <linux/seq_file.h> 67 68 #include <crypto/hash.h> 69 #include <linux/scatterlist.h> 70 71 #include <trace/events/tcp.h> 72 73 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb, 74 enum sk_rst_reason reason); 75 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 76 struct request_sock *req); 77 78 INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); 79 80 static const struct inet_connection_sock_af_ops ipv6_mapped; 81 const struct inet_connection_sock_af_ops ipv6_specific; 82 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 83 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; 84 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; 85 #endif 86 87 /* Helper returning the inet6 address from a given tcp socket. 88 * It can be used in TCP stack instead of inet6_sk(sk). 89 * This avoids a dereference and allow compiler optimizations. 90 * It is a specialized version of inet6_sk_generic(). 91 */ 92 #define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \ 93 struct tcp6_sock, tcp)->inet6) 94 95 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) 96 { 97 struct dst_entry *dst = skb_dst(skb); 98 99 if (dst && dst_hold_safe(dst)) { 100 rcu_assign_pointer(sk->sk_rx_dst, dst); 101 sk->sk_rx_dst_ifindex = skb->skb_iif; 102 sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst)); 103 } 104 } 105 106 static u32 tcp_v6_init_seq(const struct sk_buff *skb) 107 { 108 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32, 109 ipv6_hdr(skb)->saddr.s6_addr32, 110 tcp_hdr(skb)->dest, 111 tcp_hdr(skb)->source); 112 } 113 114 static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb) 115 { 116 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32, 117 ipv6_hdr(skb)->saddr.s6_addr32); 118 } 119 120 static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, 121 int addr_len) 122 { 123 /* This check is replicated from tcp_v6_connect() and intended to 124 * prevent BPF program called below from accessing bytes that are out 125 * of the bound specified by user in addr_len. 126 */ 127 if (addr_len < SIN6_LEN_RFC2133) 128 return -EINVAL; 129 130 sock_owned_by_me(sk); 131 132 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len); 133 } 134 135 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 136 int addr_len) 137 { 138 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 139 struct inet_connection_sock *icsk = inet_csk(sk); 140 struct in6_addr *saddr = NULL, *final_p, final; 141 struct inet_timewait_death_row *tcp_death_row; 142 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 143 struct inet_sock *inet = inet_sk(sk); 144 struct tcp_sock *tp = tcp_sk(sk); 145 struct net *net = sock_net(sk); 146 struct ipv6_txoptions *opt; 147 struct dst_entry *dst; 148 struct flowi6 fl6; 149 int addr_type; 150 int err; 151 152 if (addr_len < SIN6_LEN_RFC2133) 153 return -EINVAL; 154 155 if (usin->sin6_family != AF_INET6) 156 return -EAFNOSUPPORT; 157 158 memset(&fl6, 0, sizeof(fl6)); 159 160 if (inet6_test_bit(SNDFLOW, sk)) { 161 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; 162 IP6_ECN_flow_init(fl6.flowlabel); 163 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 164 struct ip6_flowlabel *flowlabel; 165 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 166 if (IS_ERR(flowlabel)) 167 return -EINVAL; 168 fl6_sock_release(flowlabel); 169 } 170 } 171 172 /* 173 * connect() to INADDR_ANY means loopback (BSD'ism). 174 */ 175 176 if (ipv6_addr_any(&usin->sin6_addr)) { 177 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) 178 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 179 &usin->sin6_addr); 180 else 181 usin->sin6_addr = in6addr_loopback; 182 } 183 184 addr_type = ipv6_addr_type(&usin->sin6_addr); 185 186 if (addr_type & IPV6_ADDR_MULTICAST) 187 return -ENETUNREACH; 188 189 if (addr_type&IPV6_ADDR_LINKLOCAL) { 190 if (addr_len >= sizeof(struct sockaddr_in6) && 191 usin->sin6_scope_id) { 192 /* If interface is set while binding, indices 193 * must coincide. 194 */ 195 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) 196 return -EINVAL; 197 198 sk->sk_bound_dev_if = usin->sin6_scope_id; 199 } 200 201 /* Connect to link-local address requires an interface */ 202 if (!sk->sk_bound_dev_if) 203 return -EINVAL; 204 } 205 206 if (tp->rx_opt.ts_recent_stamp && 207 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { 208 tp->rx_opt.ts_recent = 0; 209 tp->rx_opt.ts_recent_stamp = 0; 210 WRITE_ONCE(tp->write_seq, 0); 211 } 212 213 sk->sk_v6_daddr = usin->sin6_addr; 214 np->flow_label = fl6.flowlabel; 215 216 /* 217 * TCP over IPv4 218 */ 219 220 if (addr_type & IPV6_ADDR_MAPPED) { 221 u32 exthdrlen = icsk->icsk_ext_hdr_len; 222 struct sockaddr_in sin; 223 224 if (ipv6_only_sock(sk)) 225 return -ENETUNREACH; 226 227 sin.sin_family = AF_INET; 228 sin.sin_port = usin->sin6_port; 229 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 230 231 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ 232 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped); 233 if (sk_is_mptcp(sk)) 234 mptcpv6_handle_mapped(sk, true); 235 sk->sk_backlog_rcv = tcp_v4_do_rcv; 236 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 237 tp->af_specific = &tcp_sock_ipv6_mapped_specific; 238 #endif 239 240 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 241 242 if (err) { 243 icsk->icsk_ext_hdr_len = exthdrlen; 244 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ 245 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific); 246 if (sk_is_mptcp(sk)) 247 mptcpv6_handle_mapped(sk, false); 248 sk->sk_backlog_rcv = tcp_v6_do_rcv; 249 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 250 tp->af_specific = &tcp_sock_ipv6_specific; 251 #endif 252 goto failure; 253 } 254 np->saddr = sk->sk_v6_rcv_saddr; 255 256 return err; 257 } 258 259 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 260 saddr = &sk->sk_v6_rcv_saddr; 261 262 fl6.flowi6_proto = IPPROTO_TCP; 263 fl6.daddr = sk->sk_v6_daddr; 264 fl6.saddr = saddr ? *saddr : np->saddr; 265 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label); 266 fl6.flowi6_oif = sk->sk_bound_dev_if; 267 fl6.flowi6_mark = sk->sk_mark; 268 fl6.fl6_dport = usin->sin6_port; 269 fl6.fl6_sport = inet->inet_sport; 270 fl6.flowi6_uid = sk->sk_uid; 271 272 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); 273 final_p = fl6_update_dst(&fl6, opt, &final); 274 275 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); 276 277 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p); 278 if (IS_ERR(dst)) { 279 err = PTR_ERR(dst); 280 goto failure; 281 } 282 283 tp->tcp_usec_ts = dst_tcp_usec_ts(dst); 284 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; 285 286 if (!saddr) { 287 saddr = &fl6.saddr; 288 289 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6); 290 if (err) 291 goto failure; 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(net, np->saddr.s6_addr32, 325 sk->sk_v6_daddr.s6_addr32); 326 } 327 328 if (tcp_fastopen_defer_connect(sk, &err)) 329 return err; 330 if (err) 331 goto late_failure; 332 333 err = tcp_connect(sk); 334 if (err) 335 goto late_failure; 336 337 return 0; 338 339 late_failure: 340 tcp_set_state(sk, TCP_CLOSE); 341 inet_bhash2_reset_saddr(sk); 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 u32 mtu; 352 353 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) 354 return; 355 356 mtu = READ_ONCE(tcp_sk(sk)->mtu_info); 357 358 /* Drop requests trying to increase our current mss. 359 * Check done in __ip6_rt_update_pmtu() is too late. 360 */ 361 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache) 362 return; 363 364 dst = inet6_csk_update_pmtu(sk, mtu); 365 if (!dst) 366 return; 367 368 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { 369 tcp_sync_mss(sk, dst_mtu(dst)); 370 tcp_simple_retransmit(sk); 371 } 372 } 373 374 static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 375 u8 type, u8 code, int offset, __be32 info) 376 { 377 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 378 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); 379 struct net *net = dev_net(skb->dev); 380 struct request_sock *fastopen; 381 struct ipv6_pinfo *np; 382 struct tcp_sock *tp; 383 __u32 seq, snd_una; 384 struct sock *sk; 385 bool fatal; 386 int err; 387 388 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, 389 &hdr->daddr, th->dest, 390 &hdr->saddr, ntohs(th->source), 391 skb->dev->ifindex, inet6_sdif(skb)); 392 393 if (!sk) { 394 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 395 ICMP6_MIB_INERRORS); 396 return -ENOENT; 397 } 398 399 if (sk->sk_state == TCP_TIME_WAIT) { 400 /* To increase the counter of ignored icmps for TCP-AO */ 401 tcp_ao_ignore_icmp(sk, AF_INET6, type, code); 402 inet_twsk_put(inet_twsk(sk)); 403 return 0; 404 } 405 seq = ntohl(th->seq); 406 fatal = icmpv6_err_convert(type, code, &err); 407 if (sk->sk_state == TCP_NEW_SYN_RECV) { 408 tcp_req_err(sk, seq, fatal); 409 return 0; 410 } 411 412 if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) { 413 sock_put(sk); 414 return 0; 415 } 416 417 bh_lock_sock(sk); 418 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) 419 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); 420 421 if (sk->sk_state == TCP_CLOSE) 422 goto out; 423 424 if (static_branch_unlikely(&ip6_min_hopcount)) { 425 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ 426 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) { 427 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 428 goto out; 429 } 430 } 431 432 tp = tcp_sk(sk); 433 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ 434 fastopen = rcu_dereference(tp->fastopen_rsk); 435 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; 436 if (sk->sk_state != TCP_LISTEN && 437 !between(seq, snd_una, tp->snd_nxt)) { 438 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); 439 goto out; 440 } 441 442 np = tcp_inet6_sk(sk); 443 444 if (type == NDISC_REDIRECT) { 445 if (!sock_owned_by_user(sk)) { 446 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 447 448 if (dst) 449 dst->ops->redirect(dst, sk, skb); 450 } 451 goto out; 452 } 453 454 if (type == ICMPV6_PKT_TOOBIG) { 455 u32 mtu = ntohl(info); 456 457 /* We are not interested in TCP_LISTEN and open_requests 458 * (SYN-ACKs send out by Linux are always <576bytes so 459 * they should go through unfragmented). 460 */ 461 if (sk->sk_state == TCP_LISTEN) 462 goto out; 463 464 if (!ip6_sk_accept_pmtu(sk)) 465 goto out; 466 467 if (mtu < IPV6_MIN_MTU) 468 goto out; 469 470 WRITE_ONCE(tp->mtu_info, mtu); 471 472 if (!sock_owned_by_user(sk)) 473 tcp_v6_mtu_reduced(sk); 474 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, 475 &sk->sk_tsq_flags)) 476 sock_hold(sk); 477 goto out; 478 } 479 480 481 /* Might be for an request_sock */ 482 switch (sk->sk_state) { 483 case TCP_SYN_SENT: 484 case TCP_SYN_RECV: 485 /* Only in fast or simultaneous open. If a fast open socket is 486 * already accepted it is treated as a connected one below. 487 */ 488 if (fastopen && !fastopen->sk) 489 break; 490 491 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th); 492 493 if (!sock_owned_by_user(sk)) 494 tcp_done_with_error(sk, err); 495 else 496 WRITE_ONCE(sk->sk_err_soft, err); 497 goto out; 498 case TCP_LISTEN: 499 break; 500 default: 501 /* check if this ICMP message allows revert of backoff. 502 * (see RFC 6069) 503 */ 504 if (!fastopen && type == ICMPV6_DEST_UNREACH && 505 code == ICMPV6_NOROUTE) 506 tcp_ld_RTO_revert(sk, seq); 507 } 508 509 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) { 510 WRITE_ONCE(sk->sk_err, err); 511 sk_error_report(sk); 512 } else { 513 WRITE_ONCE(sk->sk_err_soft, err); 514 } 515 out: 516 bh_unlock_sock(sk); 517 sock_put(sk); 518 return 0; 519 } 520 521 522 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, 523 struct flowi *fl, 524 struct request_sock *req, 525 struct tcp_fastopen_cookie *foc, 526 enum tcp_synack_type synack_type, 527 struct sk_buff *syn_skb) 528 { 529 struct inet_request_sock *ireq = inet_rsk(req); 530 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 531 struct ipv6_txoptions *opt; 532 struct flowi6 *fl6 = &fl->u.ip6; 533 struct sk_buff *skb; 534 int err = -ENOMEM; 535 u8 tclass; 536 537 /* First, grab a route. */ 538 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req, 539 IPPROTO_TCP)) == NULL) 540 goto done; 541 542 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); 543 544 if (skb) { 545 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, 546 &ireq->ir_v6_rmt_addr); 547 548 fl6->daddr = ireq->ir_v6_rmt_addr; 549 if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts) 550 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); 551 552 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? 553 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | 554 (np->tclass & INET_ECN_MASK) : 555 np->tclass; 556 557 if (!INET_ECN_is_capable(tclass) && 558 tcp_bpf_ca_needs_ecn((struct sock *)req)) 559 tclass |= INET_ECN_ECT_0; 560 561 rcu_read_lock(); 562 opt = ireq->ipv6_opt; 563 if (!opt) 564 opt = rcu_dereference(np->opt); 565 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark), 566 opt, tclass, READ_ONCE(sk->sk_priority)); 567 rcu_read_unlock(); 568 err = net_xmit_eval(err); 569 } 570 571 done: 572 return err; 573 } 574 575 576 static void tcp_v6_reqsk_destructor(struct request_sock *req) 577 { 578 kfree(inet_rsk(req)->ipv6_opt); 579 consume_skb(inet_rsk(req)->pktopts); 580 } 581 582 #ifdef CONFIG_TCP_MD5SIG 583 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, 584 const struct in6_addr *addr, 585 int l3index) 586 { 587 return tcp_md5_do_lookup(sk, l3index, 588 (union tcp_md5_addr *)addr, AF_INET6); 589 } 590 591 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, 592 const struct sock *addr_sk) 593 { 594 int l3index; 595 596 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), 597 addr_sk->sk_bound_dev_if); 598 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr, 599 l3index); 600 } 601 602 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, 603 sockptr_t optval, int optlen) 604 { 605 struct tcp_md5sig cmd; 606 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; 607 union tcp_ao_addr *addr; 608 int l3index = 0; 609 u8 prefixlen; 610 bool l3flag; 611 u8 flags; 612 613 if (optlen < sizeof(cmd)) 614 return -EINVAL; 615 616 if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) 617 return -EFAULT; 618 619 if (sin6->sin6_family != AF_INET6) 620 return -EINVAL; 621 622 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; 623 l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; 624 625 if (optname == TCP_MD5SIG_EXT && 626 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { 627 prefixlen = cmd.tcpm_prefixlen; 628 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && 629 prefixlen > 32)) 630 return -EINVAL; 631 } else { 632 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; 633 } 634 635 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex && 636 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { 637 struct net_device *dev; 638 639 rcu_read_lock(); 640 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); 641 if (dev && netif_is_l3_master(dev)) 642 l3index = dev->ifindex; 643 rcu_read_unlock(); 644 645 /* ok to reference set/not set outside of rcu; 646 * right now device MUST be an L3 master 647 */ 648 if (!dev || !l3index) 649 return -EINVAL; 650 } 651 652 if (!cmd.tcpm_keylen) { 653 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 654 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 655 AF_INET, prefixlen, 656 l3index, flags); 657 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 658 AF_INET6, prefixlen, l3index, flags); 659 } 660 661 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) 662 return -EINVAL; 663 664 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { 665 addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3]; 666 667 /* Don't allow keys for peers that have a matching TCP-AO key. 668 * See the comment in tcp_ao_add_cmd() 669 */ 670 if (tcp_ao_required(sk, addr, AF_INET, 671 l3flag ? l3index : -1, false)) 672 return -EKEYREJECTED; 673 return tcp_md5_do_add(sk, addr, 674 AF_INET, prefixlen, l3index, flags, 675 cmd.tcpm_key, cmd.tcpm_keylen); 676 } 677 678 addr = (union tcp_md5_addr *)&sin6->sin6_addr; 679 680 /* Don't allow keys for peers that have a matching TCP-AO key. 681 * See the comment in tcp_ao_add_cmd() 682 */ 683 if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false)) 684 return -EKEYREJECTED; 685 686 return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags, 687 cmd.tcpm_key, cmd.tcpm_keylen); 688 } 689 690 static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp, 691 const struct in6_addr *daddr, 692 const struct in6_addr *saddr, 693 const struct tcphdr *th, int nbytes) 694 { 695 struct tcp6_pseudohdr *bp; 696 struct scatterlist sg; 697 struct tcphdr *_th; 698 699 bp = hp->scratch; 700 /* 1. TCP pseudo-header (RFC2460) */ 701 bp->saddr = *saddr; 702 bp->daddr = *daddr; 703 bp->protocol = cpu_to_be32(IPPROTO_TCP); 704 bp->len = cpu_to_be32(nbytes); 705 706 _th = (struct tcphdr *)(bp + 1); 707 memcpy(_th, th, sizeof(*th)); 708 _th->check = 0; 709 710 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); 711 ahash_request_set_crypt(hp->req, &sg, NULL, 712 sizeof(*bp) + sizeof(*th)); 713 return crypto_ahash_update(hp->req); 714 } 715 716 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, 717 const struct in6_addr *daddr, struct in6_addr *saddr, 718 const struct tcphdr *th) 719 { 720 struct tcp_sigpool hp; 721 722 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) 723 goto clear_hash_nostart; 724 725 if (crypto_ahash_init(hp.req)) 726 goto clear_hash; 727 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2)) 728 goto clear_hash; 729 if (tcp_md5_hash_key(&hp, key)) 730 goto clear_hash; 731 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0); 732 if (crypto_ahash_final(hp.req)) 733 goto clear_hash; 734 735 tcp_sigpool_end(&hp); 736 return 0; 737 738 clear_hash: 739 tcp_sigpool_end(&hp); 740 clear_hash_nostart: 741 memset(md5_hash, 0, 16); 742 return 1; 743 } 744 745 static int tcp_v6_md5_hash_skb(char *md5_hash, 746 const struct tcp_md5sig_key *key, 747 const struct sock *sk, 748 const struct sk_buff *skb) 749 { 750 const struct tcphdr *th = tcp_hdr(skb); 751 const struct in6_addr *saddr, *daddr; 752 struct tcp_sigpool hp; 753 754 if (sk) { /* valid for establish/request sockets */ 755 saddr = &sk->sk_v6_rcv_saddr; 756 daddr = &sk->sk_v6_daddr; 757 } else { 758 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 759 saddr = &ip6h->saddr; 760 daddr = &ip6h->daddr; 761 } 762 763 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) 764 goto clear_hash_nostart; 765 766 if (crypto_ahash_init(hp.req)) 767 goto clear_hash; 768 769 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len)) 770 goto clear_hash; 771 if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2)) 772 goto clear_hash; 773 if (tcp_md5_hash_key(&hp, key)) 774 goto clear_hash; 775 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0); 776 if (crypto_ahash_final(hp.req)) 777 goto clear_hash; 778 779 tcp_sigpool_end(&hp); 780 return 0; 781 782 clear_hash: 783 tcp_sigpool_end(&hp); 784 clear_hash_nostart: 785 memset(md5_hash, 0, 16); 786 return 1; 787 } 788 #endif 789 790 static void tcp_v6_init_req(struct request_sock *req, 791 const struct sock *sk_listener, 792 struct sk_buff *skb, 793 u32 tw_isn) 794 { 795 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); 796 struct inet_request_sock *ireq = inet_rsk(req); 797 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener); 798 799 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 800 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 801 802 /* So that link locals have meaning */ 803 if ((!sk_listener->sk_bound_dev_if || l3_slave) && 804 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 805 ireq->ir_iif = tcp_v6_iif(skb); 806 807 if (!tw_isn && 808 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) || 809 np->rxopt.bits.rxinfo || 810 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || 811 np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) { 812 refcount_inc(&skb->users); 813 ireq->pktopts = skb; 814 } 815 } 816 817 static struct dst_entry *tcp_v6_route_req(const struct sock *sk, 818 struct sk_buff *skb, 819 struct flowi *fl, 820 struct request_sock *req, 821 u32 tw_isn) 822 { 823 tcp_v6_init_req(req, sk, skb, tw_isn); 824 825 if (security_inet_conn_request(sk, skb, req)) 826 return NULL; 827 828 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP); 829 } 830 831 struct request_sock_ops tcp6_request_sock_ops __read_mostly = { 832 .family = AF_INET6, 833 .obj_size = sizeof(struct tcp6_request_sock), 834 .rtx_syn_ack = tcp_rtx_synack, 835 .send_ack = tcp_v6_reqsk_send_ack, 836 .destructor = tcp_v6_reqsk_destructor, 837 .send_reset = tcp_v6_send_reset, 838 .syn_ack_timeout = tcp_syn_ack_timeout, 839 }; 840 841 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { 842 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - 843 sizeof(struct ipv6hdr), 844 #ifdef CONFIG_TCP_MD5SIG 845 .req_md5_lookup = tcp_v6_md5_lookup, 846 .calc_md5_hash = tcp_v6_md5_hash_skb, 847 #endif 848 #ifdef CONFIG_TCP_AO 849 .ao_lookup = tcp_v6_ao_lookup_rsk, 850 .ao_calc_key = tcp_v6_ao_calc_key_rsk, 851 .ao_synack_hash = tcp_v6_ao_synack_hash, 852 #endif 853 #ifdef CONFIG_SYN_COOKIES 854 .cookie_init_seq = cookie_v6_init_sequence, 855 #endif 856 .route_req = tcp_v6_route_req, 857 .init_seq = tcp_v6_init_seq, 858 .init_ts_off = tcp_v6_init_ts_off, 859 .send_synack = tcp_v6_send_synack, 860 }; 861 862 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, 863 u32 ack, u32 win, u32 tsval, u32 tsecr, 864 int oif, int rst, u8 tclass, __be32 label, 865 u32 priority, u32 txhash, struct tcp_key *key) 866 { 867 const struct tcphdr *th = tcp_hdr(skb); 868 struct tcphdr *t1; 869 struct sk_buff *buff; 870 struct flowi6 fl6; 871 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); 872 struct sock *ctl_sk = net->ipv6.tcp_sk; 873 unsigned int tot_len = sizeof(struct tcphdr); 874 __be32 mrst = 0, *topt; 875 struct dst_entry *dst; 876 __u32 mark = 0; 877 878 if (tsecr) 879 tot_len += TCPOLEN_TSTAMP_ALIGNED; 880 if (tcp_key_is_md5(key)) 881 tot_len += TCPOLEN_MD5SIG_ALIGNED; 882 if (tcp_key_is_ao(key)) 883 tot_len += tcp_ao_len_aligned(key->ao_key); 884 885 #ifdef CONFIG_MPTCP 886 if (rst && !tcp_key_is_md5(key)) { 887 mrst = mptcp_reset_option(skb); 888 889 if (mrst) 890 tot_len += sizeof(__be32); 891 } 892 #endif 893 894 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); 895 if (!buff) 896 return; 897 898 skb_reserve(buff, MAX_TCP_HEADER); 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 if (mrst) 924 *topt++ = mrst; 925 926 #ifdef CONFIG_TCP_MD5SIG 927 if (tcp_key_is_md5(key)) { 928 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 929 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); 930 tcp_v6_md5_hash_hdr((__u8 *)topt, key->md5_key, 931 &ipv6_hdr(skb)->saddr, 932 &ipv6_hdr(skb)->daddr, t1); 933 } 934 #endif 935 #ifdef CONFIG_TCP_AO 936 if (tcp_key_is_ao(key)) { 937 *topt++ = htonl((TCPOPT_AO << 24) | 938 (tcp_ao_len(key->ao_key) << 16) | 939 (key->ao_key->sndid << 8) | 940 (key->rcv_next)); 941 942 tcp_ao_hash_hdr(AF_INET6, (char *)topt, key->ao_key, 943 key->traffic_key, 944 (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr, 945 (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr, 946 t1, key->sne); 947 } 948 #endif 949 950 memset(&fl6, 0, sizeof(fl6)); 951 fl6.daddr = ipv6_hdr(skb)->saddr; 952 fl6.saddr = ipv6_hdr(skb)->daddr; 953 fl6.flowlabel = label; 954 955 buff->ip_summed = CHECKSUM_PARTIAL; 956 957 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); 958 959 fl6.flowi6_proto = IPPROTO_TCP; 960 if (rt6_need_strict(&fl6.daddr) && !oif) 961 fl6.flowi6_oif = tcp_v6_iif(skb); 962 else { 963 if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) 964 oif = skb->skb_iif; 965 966 fl6.flowi6_oif = oif; 967 } 968 969 if (sk) { 970 if (sk->sk_state == TCP_TIME_WAIT) 971 mark = inet_twsk(sk)->tw_mark; 972 else 973 mark = READ_ONCE(sk->sk_mark); 974 skb_set_delivery_time(buff, tcp_transmit_time(sk), SKB_CLOCK_MONOTONIC); 975 } 976 if (txhash) { 977 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */ 978 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4); 979 } 980 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; 981 fl6.fl6_dport = t1->dest; 982 fl6.fl6_sport = t1->source; 983 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); 984 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); 985 986 /* Pass a socket to ip6_dst_lookup either it is for RST 987 * Underlying function will use this to retrieve the network 988 * namespace 989 */ 990 if (sk && sk->sk_state != TCP_TIME_WAIT) 991 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/ 992 else 993 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL); 994 if (!IS_ERR(dst)) { 995 skb_dst_set(buff, dst); 996 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, 997 tclass & ~INET_ECN_MASK, priority); 998 TCP_INC_STATS(net, TCP_MIB_OUTSEGS); 999 if (rst) 1000 TCP_INC_STATS(net, TCP_MIB_OUTRSTS); 1001 return; 1002 } 1003 1004 kfree_skb(buff); 1005 } 1006 1007 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb, 1008 enum sk_rst_reason reason) 1009 { 1010 const struct tcphdr *th = tcp_hdr(skb); 1011 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1012 const __u8 *md5_hash_location = NULL; 1013 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1014 bool allocated_traffic_key = false; 1015 #endif 1016 const struct tcp_ao_hdr *aoh; 1017 struct tcp_key key = {}; 1018 u32 seq = 0, ack_seq = 0; 1019 __be32 label = 0; 1020 u32 priority = 0; 1021 struct net *net; 1022 u32 txhash = 0; 1023 int oif = 0; 1024 #ifdef CONFIG_TCP_MD5SIG 1025 unsigned char newhash[16]; 1026 int genhash; 1027 struct sock *sk1 = NULL; 1028 #endif 1029 1030 if (th->rst) 1031 return; 1032 1033 /* If sk not NULL, it means we did a successful lookup and incoming 1034 * route had to be correct. prequeue might have dropped our dst. 1035 */ 1036 if (!sk && !ipv6_unicast_destination(skb)) 1037 return; 1038 1039 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); 1040 /* Invalid TCP option size or twice included auth */ 1041 if (tcp_parse_auth_options(th, &md5_hash_location, &aoh)) 1042 return; 1043 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1044 rcu_read_lock(); 1045 #endif 1046 #ifdef CONFIG_TCP_MD5SIG 1047 if (sk && sk_fullsock(sk)) { 1048 int l3index; 1049 1050 /* sdif set, means packet ingressed via a device 1051 * in an L3 domain and inet_iif is set to it. 1052 */ 1053 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1054 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index); 1055 if (key.md5_key) 1056 key.type = TCP_KEY_MD5; 1057 } else if (md5_hash_location) { 1058 int dif = tcp_v6_iif_l3_slave(skb); 1059 int sdif = tcp_v6_sdif(skb); 1060 int l3index; 1061 1062 /* 1063 * active side is lost. Try to find listening socket through 1064 * source port, and then find md5 key through listening socket. 1065 * we are not loose security here: 1066 * Incoming packet is checked with md5 hash with finding key, 1067 * no RST generated if md5 hash doesn't match. 1068 */ 1069 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, 1070 NULL, 0, &ipv6h->saddr, th->source, 1071 &ipv6h->daddr, ntohs(th->source), 1072 dif, sdif); 1073 if (!sk1) 1074 goto out; 1075 1076 /* sdif set, means packet ingressed via a device 1077 * in an L3 domain and dif is set to it. 1078 */ 1079 l3index = tcp_v6_sdif(skb) ? dif : 0; 1080 1081 key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index); 1082 if (!key.md5_key) 1083 goto out; 1084 key.type = TCP_KEY_MD5; 1085 1086 genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb); 1087 if (genhash || memcmp(md5_hash_location, newhash, 16) != 0) 1088 goto out; 1089 } 1090 #endif 1091 1092 if (th->ack) 1093 seq = ntohl(th->ack_seq); 1094 else 1095 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - 1096 (th->doff << 2); 1097 1098 #ifdef CONFIG_TCP_AO 1099 if (aoh) { 1100 int l3index; 1101 1102 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1103 if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq, 1104 &key.ao_key, &key.traffic_key, 1105 &allocated_traffic_key, 1106 &key.rcv_next, &key.sne)) 1107 goto out; 1108 key.type = TCP_KEY_AO; 1109 } 1110 #endif 1111 1112 if (sk) { 1113 oif = sk->sk_bound_dev_if; 1114 if (sk_fullsock(sk)) { 1115 if (inet6_test_bit(REPFLOW, sk)) 1116 label = ip6_flowlabel(ipv6h); 1117 priority = READ_ONCE(sk->sk_priority); 1118 txhash = sk->sk_txhash; 1119 } 1120 if (sk->sk_state == TCP_TIME_WAIT) { 1121 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); 1122 priority = inet_twsk(sk)->tw_priority; 1123 txhash = inet_twsk(sk)->tw_txhash; 1124 } 1125 } else { 1126 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) 1127 label = ip6_flowlabel(ipv6h); 1128 } 1129 1130 trace_tcp_send_reset(sk, skb, reason); 1131 1132 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1, 1133 ipv6_get_dsfield(ipv6h), label, priority, txhash, 1134 &key); 1135 1136 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1137 out: 1138 if (allocated_traffic_key) 1139 kfree(key.traffic_key); 1140 rcu_read_unlock(); 1141 #endif 1142 } 1143 1144 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, 1145 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, 1146 struct tcp_key *key, u8 tclass, 1147 __be32 label, u32 priority, u32 txhash) 1148 { 1149 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0, 1150 tclass, label, priority, txhash, key); 1151 } 1152 1153 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) 1154 { 1155 struct inet_timewait_sock *tw = inet_twsk(sk); 1156 struct tcp_timewait_sock *tcptw = tcp_twsk(sk); 1157 struct tcp_key key = {}; 1158 #ifdef CONFIG_TCP_AO 1159 struct tcp_ao_info *ao_info; 1160 1161 if (static_branch_unlikely(&tcp_ao_needed.key)) { 1162 1163 /* FIXME: the segment to-be-acked is not verified yet */ 1164 ao_info = rcu_dereference(tcptw->ao_info); 1165 if (ao_info) { 1166 const struct tcp_ao_hdr *aoh; 1167 1168 /* Invalid TCP option size or twice included auth */ 1169 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) 1170 goto out; 1171 if (aoh) 1172 key.ao_key = tcp_ao_established_key(ao_info, 1173 aoh->rnext_keyid, -1); 1174 } 1175 } 1176 if (key.ao_key) { 1177 struct tcp_ao_key *rnext_key; 1178 1179 key.traffic_key = snd_other_key(key.ao_key); 1180 /* rcv_next switches to our rcv_next */ 1181 rnext_key = READ_ONCE(ao_info->rnext_key); 1182 key.rcv_next = rnext_key->rcvid; 1183 key.sne = READ_ONCE(ao_info->snd_sne); 1184 key.type = TCP_KEY_AO; 1185 #else 1186 if (0) { 1187 #endif 1188 #ifdef CONFIG_TCP_MD5SIG 1189 } else if (static_branch_unlikely(&tcp_md5_needed.key)) { 1190 key.md5_key = tcp_twsk_md5_key(tcptw); 1191 if (key.md5_key) 1192 key.type = TCP_KEY_MD5; 1193 #endif 1194 } 1195 1196 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, 1197 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, 1198 tcp_tw_tsval(tcptw), 1199 READ_ONCE(tcptw->tw_ts_recent), tw->tw_bound_dev_if, 1200 &key, tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), 1201 tw->tw_priority, tw->tw_txhash); 1202 1203 #ifdef CONFIG_TCP_AO 1204 out: 1205 #endif 1206 inet_twsk_put(tw); 1207 } 1208 1209 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 1210 struct request_sock *req) 1211 { 1212 struct tcp_key key = {}; 1213 1214 #ifdef CONFIG_TCP_AO 1215 if (static_branch_unlikely(&tcp_ao_needed.key) && 1216 tcp_rsk_used_ao(req)) { 1217 const struct in6_addr *addr = &ipv6_hdr(skb)->saddr; 1218 const struct tcp_ao_hdr *aoh; 1219 int l3index; 1220 1221 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1222 /* Invalid TCP option size or twice included auth */ 1223 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) 1224 return; 1225 if (!aoh) 1226 return; 1227 key.ao_key = tcp_ao_do_lookup(sk, l3index, 1228 (union tcp_ao_addr *)addr, 1229 AF_INET6, aoh->rnext_keyid, -1); 1230 if (unlikely(!key.ao_key)) { 1231 /* Send ACK with any matching MKT for the peer */ 1232 key.ao_key = tcp_ao_do_lookup(sk, l3index, 1233 (union tcp_ao_addr *)addr, 1234 AF_INET6, -1, -1); 1235 /* Matching key disappeared (user removed the key?) 1236 * let the handshake timeout. 1237 */ 1238 if (!key.ao_key) { 1239 net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n", 1240 addr, 1241 ntohs(tcp_hdr(skb)->source), 1242 &ipv6_hdr(skb)->daddr, 1243 ntohs(tcp_hdr(skb)->dest)); 1244 return; 1245 } 1246 } 1247 key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC); 1248 if (!key.traffic_key) 1249 return; 1250 1251 key.type = TCP_KEY_AO; 1252 key.rcv_next = aoh->keyid; 1253 tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req); 1254 #else 1255 if (0) { 1256 #endif 1257 #ifdef CONFIG_TCP_MD5SIG 1258 } else if (static_branch_unlikely(&tcp_md5_needed.key)) { 1259 int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1260 1261 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, 1262 l3index); 1263 if (key.md5_key) 1264 key.type = TCP_KEY_MD5; 1265 #endif 1266 } 1267 1268 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV 1269 * sk->sk_state == TCP_SYN_RECV -> for Fast Open. 1270 */ 1271 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ? 1272 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, 1273 tcp_rsk(req)->rcv_nxt, 1274 tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale, 1275 tcp_rsk_tsval(tcp_rsk(req)), 1276 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if, 1277 &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0, 1278 READ_ONCE(sk->sk_priority), 1279 READ_ONCE(tcp_rsk(req)->txhash)); 1280 if (tcp_key_is_ao(&key)) 1281 kfree(key.traffic_key); 1282 } 1283 1284 1285 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb) 1286 { 1287 #ifdef CONFIG_SYN_COOKIES 1288 const struct tcphdr *th = tcp_hdr(skb); 1289 1290 if (!th->syn) 1291 sk = cookie_v6_check(sk, skb); 1292 #endif 1293 return sk; 1294 } 1295 1296 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, 1297 struct tcphdr *th, u32 *cookie) 1298 { 1299 u16 mss = 0; 1300 #ifdef CONFIG_SYN_COOKIES 1301 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops, 1302 &tcp_request_sock_ipv6_ops, sk, th); 1303 if (mss) { 1304 *cookie = __cookie_v6_init_sequence(iph, th, &mss); 1305 tcp_synq_overflow(sk); 1306 } 1307 #endif 1308 return mss; 1309 } 1310 1311 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 1312 { 1313 if (skb->protocol == htons(ETH_P_IP)) 1314 return tcp_v4_conn_request(sk, skb); 1315 1316 if (!ipv6_unicast_destination(skb)) 1317 goto drop; 1318 1319 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { 1320 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); 1321 return 0; 1322 } 1323 1324 return tcp_conn_request(&tcp6_request_sock_ops, 1325 &tcp_request_sock_ipv6_ops, sk, skb); 1326 1327 drop: 1328 tcp_listendrop(sk); 1329 return 0; /* don't send reset */ 1330 } 1331 1332 static void tcp_v6_restore_cb(struct sk_buff *skb) 1333 { 1334 /* We need to move header back to the beginning if xfrm6_policy_check() 1335 * and tcp_v6_fill_cb() are going to be called again. 1336 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there. 1337 */ 1338 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6, 1339 sizeof(struct inet6_skb_parm)); 1340 } 1341 1342 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, 1343 struct request_sock *req, 1344 struct dst_entry *dst, 1345 struct request_sock *req_unhash, 1346 bool *own_req) 1347 { 1348 struct inet_request_sock *ireq; 1349 struct ipv6_pinfo *newnp; 1350 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1351 struct ipv6_txoptions *opt; 1352 struct inet_sock *newinet; 1353 bool found_dup_sk = false; 1354 struct tcp_sock *newtp; 1355 struct sock *newsk; 1356 #ifdef CONFIG_TCP_MD5SIG 1357 struct tcp_md5sig_key *key; 1358 int l3index; 1359 #endif 1360 struct flowi6 fl6; 1361 1362 if (skb->protocol == htons(ETH_P_IP)) { 1363 /* 1364 * v6 mapped 1365 */ 1366 1367 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst, 1368 req_unhash, own_req); 1369 1370 if (!newsk) 1371 return NULL; 1372 1373 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1374 1375 newnp = tcp_inet6_sk(newsk); 1376 newtp = tcp_sk(newsk); 1377 1378 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1379 1380 newnp->saddr = newsk->sk_v6_rcv_saddr; 1381 1382 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; 1383 if (sk_is_mptcp(newsk)) 1384 mptcpv6_handle_mapped(newsk, true); 1385 newsk->sk_backlog_rcv = tcp_v4_do_rcv; 1386 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1387 newtp->af_specific = &tcp_sock_ipv6_mapped_specific; 1388 #endif 1389 1390 newnp->ipv6_mc_list = NULL; 1391 newnp->ipv6_ac_list = NULL; 1392 newnp->ipv6_fl_list = NULL; 1393 newnp->pktoptions = NULL; 1394 newnp->opt = NULL; 1395 newnp->mcast_oif = inet_iif(skb); 1396 newnp->mcast_hops = ip_hdr(skb)->ttl; 1397 newnp->rcv_flowinfo = 0; 1398 if (inet6_test_bit(REPFLOW, sk)) 1399 newnp->flow_label = 0; 1400 1401 /* 1402 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 1403 * here, tcp_create_openreq_child now does this for us, see the comment in 1404 * that function for the gory details. -acme 1405 */ 1406 1407 /* It is tricky place. Until this moment IPv4 tcp 1408 worked with IPv6 icsk.icsk_af_ops. 1409 Sync it now. 1410 */ 1411 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 1412 1413 return newsk; 1414 } 1415 1416 ireq = inet_rsk(req); 1417 1418 if (sk_acceptq_is_full(sk)) 1419 goto out_overflow; 1420 1421 if (!dst) { 1422 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP); 1423 if (!dst) 1424 goto out; 1425 } 1426 1427 newsk = tcp_create_openreq_child(sk, req, skb); 1428 if (!newsk) 1429 goto out_nonewsk; 1430 1431 /* 1432 * No need to charge this sock to the relevant IPv6 refcnt debug socks 1433 * count here, tcp_create_openreq_child now does this for us, see the 1434 * comment in that function for the gory details. -acme 1435 */ 1436 1437 newsk->sk_gso_type = SKB_GSO_TCPV6; 1438 ip6_dst_store(newsk, dst, NULL, NULL); 1439 inet6_sk_rx_dst_set(newsk, skb); 1440 1441 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1442 1443 newtp = tcp_sk(newsk); 1444 newinet = inet_sk(newsk); 1445 newnp = tcp_inet6_sk(newsk); 1446 1447 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1448 1449 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 1450 newnp->saddr = ireq->ir_v6_loc_addr; 1451 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 1452 newsk->sk_bound_dev_if = ireq->ir_iif; 1453 1454 /* Now IPv6 options... 1455 1456 First: no IPv4 options. 1457 */ 1458 newinet->inet_opt = NULL; 1459 newnp->ipv6_mc_list = NULL; 1460 newnp->ipv6_ac_list = NULL; 1461 newnp->ipv6_fl_list = NULL; 1462 1463 /* Clone RX bits */ 1464 newnp->rxopt.all = np->rxopt.all; 1465 1466 newnp->pktoptions = NULL; 1467 newnp->opt = NULL; 1468 newnp->mcast_oif = tcp_v6_iif(skb); 1469 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1470 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb)); 1471 if (inet6_test_bit(REPFLOW, sk)) 1472 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); 1473 1474 /* Set ToS of the new socket based upon the value of incoming SYN. 1475 * ECT bits are set later in tcp_init_transfer(). 1476 */ 1477 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) 1478 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; 1479 1480 /* Clone native IPv6 options from listening socket (if any) 1481 1482 Yes, keeping reference count would be much more clever, 1483 but we make one more one thing there: reattach optmem 1484 to newsk. 1485 */ 1486 opt = ireq->ipv6_opt; 1487 if (!opt) 1488 opt = rcu_dereference(np->opt); 1489 if (opt) { 1490 opt = ipv6_dup_options(newsk, opt); 1491 RCU_INIT_POINTER(newnp->opt, opt); 1492 } 1493 inet_csk(newsk)->icsk_ext_hdr_len = 0; 1494 if (opt) 1495 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + 1496 opt->opt_flen; 1497 1498 tcp_ca_openreq_child(newsk, dst); 1499 1500 tcp_sync_mss(newsk, dst_mtu(dst)); 1501 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); 1502 1503 tcp_initialize_rcv_mss(newsk); 1504 1505 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 1506 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 1507 1508 #ifdef CONFIG_TCP_MD5SIG 1509 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); 1510 1511 if (!tcp_rsk_used_ao(req)) { 1512 /* Copy over the MD5 key from the original socket */ 1513 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index); 1514 if (key) { 1515 const union tcp_md5_addr *addr; 1516 1517 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr; 1518 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) { 1519 inet_csk_prepare_forced_close(newsk); 1520 tcp_done(newsk); 1521 goto out; 1522 } 1523 } 1524 } 1525 #endif 1526 #ifdef CONFIG_TCP_AO 1527 /* Copy over tcp_ao_info if any */ 1528 if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6)) 1529 goto out; /* OOM */ 1530 #endif 1531 1532 if (__inet_inherit_port(sk, newsk) < 0) { 1533 inet_csk_prepare_forced_close(newsk); 1534 tcp_done(newsk); 1535 goto out; 1536 } 1537 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), 1538 &found_dup_sk); 1539 if (*own_req) { 1540 tcp_move_syn(newtp, req); 1541 1542 /* Clone pktoptions received with SYN, if we own the req */ 1543 if (ireq->pktopts) { 1544 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk); 1545 consume_skb(ireq->pktopts); 1546 ireq->pktopts = NULL; 1547 if (newnp->pktoptions) 1548 tcp_v6_restore_cb(newnp->pktoptions); 1549 } 1550 } else { 1551 if (!req_unhash && found_dup_sk) { 1552 /* This code path should only be executed in the 1553 * syncookie case only 1554 */ 1555 bh_unlock_sock(newsk); 1556 sock_put(newsk); 1557 newsk = NULL; 1558 } 1559 } 1560 1561 return newsk; 1562 1563 out_overflow: 1564 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 1565 out_nonewsk: 1566 dst_release(dst); 1567 out: 1568 tcp_listendrop(sk); 1569 return NULL; 1570 } 1571 1572 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, 1573 u32)); 1574 /* The socket must have it's spinlock held when we get 1575 * here, unless it is a TCP_LISTEN socket. 1576 * 1577 * We have a potential double-lock case here, so even when 1578 * doing backlog processing we use the BH locking scheme. 1579 * This is because we cannot sleep with the original spinlock 1580 * held. 1581 */ 1582 INDIRECT_CALLABLE_SCOPE 1583 int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 1584 { 1585 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1586 struct sk_buff *opt_skb = NULL; 1587 enum skb_drop_reason reason; 1588 struct tcp_sock *tp; 1589 1590 /* Imagine: socket is IPv6. IPv4 packet arrives, 1591 goes to IPv4 receive handler and backlogged. 1592 From backlog it always goes here. Kerboom... 1593 Fortunately, tcp_rcv_established and rcv_established 1594 handle them correctly, but it is not case with 1595 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK 1596 */ 1597 1598 if (skb->protocol == htons(ETH_P_IP)) 1599 return tcp_v4_do_rcv(sk, skb); 1600 1601 /* 1602 * socket locking is here for SMP purposes as backlog rcv 1603 * is currently called with bh processing disabled. 1604 */ 1605 1606 /* Do Stevens' IPV6_PKTOPTIONS. 1607 1608 Yes, guys, it is the only place in our code, where we 1609 may make it not affecting IPv4. 1610 The rest of code is protocol independent, 1611 and I do not like idea to uglify IPv4. 1612 1613 Actually, all the idea behind IPV6_PKTOPTIONS 1614 looks not very well thought. For now we latch 1615 options, received in the last packet, enqueued 1616 by tcp. Feel free to propose better solution. 1617 --ANK (980728) 1618 */ 1619 if (np->rxopt.all) 1620 opt_skb = skb_clone_and_charge_r(skb, sk); 1621 1622 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ 1623 struct dst_entry *dst; 1624 1625 dst = rcu_dereference_protected(sk->sk_rx_dst, 1626 lockdep_sock_is_held(sk)); 1627 1628 sock_rps_save_rxhash(sk, skb); 1629 sk_mark_napi_id(sk, skb); 1630 if (dst) { 1631 if (sk->sk_rx_dst_ifindex != skb->skb_iif || 1632 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check, 1633 dst, sk->sk_rx_dst_cookie) == NULL) { 1634 RCU_INIT_POINTER(sk->sk_rx_dst, NULL); 1635 dst_release(dst); 1636 } 1637 } 1638 1639 tcp_rcv_established(sk, skb); 1640 if (opt_skb) 1641 goto ipv6_pktoptions; 1642 return 0; 1643 } 1644 1645 if (tcp_checksum_complete(skb)) 1646 goto csum_err; 1647 1648 if (sk->sk_state == TCP_LISTEN) { 1649 struct sock *nsk = tcp_v6_cookie_check(sk, skb); 1650 1651 if (nsk != sk) { 1652 if (nsk) { 1653 reason = tcp_child_process(sk, nsk, skb); 1654 if (reason) 1655 goto reset; 1656 } 1657 if (opt_skb) 1658 __kfree_skb(opt_skb); 1659 return 0; 1660 } 1661 } else 1662 sock_rps_save_rxhash(sk, skb); 1663 1664 reason = tcp_rcv_state_process(sk, skb); 1665 if (reason) 1666 goto reset; 1667 if (opt_skb) 1668 goto ipv6_pktoptions; 1669 return 0; 1670 1671 reset: 1672 tcp_v6_send_reset(sk, skb, sk_rst_convert_drop_reason(reason)); 1673 discard: 1674 if (opt_skb) 1675 __kfree_skb(opt_skb); 1676 kfree_skb_reason(skb, reason); 1677 return 0; 1678 csum_err: 1679 reason = SKB_DROP_REASON_TCP_CSUM; 1680 trace_tcp_bad_csum(skb); 1681 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); 1682 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); 1683 goto discard; 1684 1685 1686 ipv6_pktoptions: 1687 /* Do you ask, what is it? 1688 1689 1. skb was enqueued by tcp. 1690 2. skb is added to tail of read queue, rather than out of order. 1691 3. socket is not in passive state. 1692 4. Finally, it really contains options, which user wants to receive. 1693 */ 1694 tp = tcp_sk(sk); 1695 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && 1696 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { 1697 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) 1698 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb)); 1699 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) 1700 WRITE_ONCE(np->mcast_hops, 1701 ipv6_hdr(opt_skb)->hop_limit); 1702 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) 1703 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); 1704 if (inet6_test_bit(REPFLOW, sk)) 1705 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); 1706 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { 1707 tcp_v6_restore_cb(opt_skb); 1708 opt_skb = xchg(&np->pktoptions, opt_skb); 1709 } else { 1710 __kfree_skb(opt_skb); 1711 opt_skb = xchg(&np->pktoptions, NULL); 1712 } 1713 } 1714 1715 consume_skb(opt_skb); 1716 return 0; 1717 } 1718 1719 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, 1720 const struct tcphdr *th) 1721 { 1722 /* This is tricky: we move IP6CB at its correct location into 1723 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because 1724 * _decode_session6() uses IP6CB(). 1725 * barrier() makes sure compiler won't play aliasing games. 1726 */ 1727 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), 1728 sizeof(struct inet6_skb_parm)); 1729 barrier(); 1730 1731 TCP_SKB_CB(skb)->seq = ntohl(th->seq); 1732 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + 1733 skb->len - th->doff*4); 1734 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); 1735 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); 1736 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); 1737 TCP_SKB_CB(skb)->sacked = 0; 1738 TCP_SKB_CB(skb)->has_rxtstamp = 1739 skb->tstamp || skb_hwtstamps(skb)->hwtstamp; 1740 } 1741 1742 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) 1743 { 1744 enum skb_drop_reason drop_reason; 1745 int sdif = inet6_sdif(skb); 1746 int dif = inet6_iif(skb); 1747 const struct tcphdr *th; 1748 const struct ipv6hdr *hdr; 1749 bool refcounted; 1750 struct sock *sk; 1751 int ret; 1752 u32 isn; 1753 struct net *net = dev_net(skb->dev); 1754 1755 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; 1756 if (skb->pkt_type != PACKET_HOST) 1757 goto discard_it; 1758 1759 /* 1760 * Count it even if it's bad. 1761 */ 1762 __TCP_INC_STATS(net, TCP_MIB_INSEGS); 1763 1764 if (!pskb_may_pull(skb, sizeof(struct tcphdr))) 1765 goto discard_it; 1766 1767 th = (const struct tcphdr *)skb->data; 1768 1769 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { 1770 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; 1771 goto bad_packet; 1772 } 1773 if (!pskb_may_pull(skb, th->doff*4)) 1774 goto discard_it; 1775 1776 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo)) 1777 goto csum_error; 1778 1779 th = (const struct tcphdr *)skb->data; 1780 hdr = ipv6_hdr(skb); 1781 1782 lookup: 1783 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th), 1784 th->source, th->dest, inet6_iif(skb), sdif, 1785 &refcounted); 1786 if (!sk) 1787 goto no_tcp_socket; 1788 1789 if (sk->sk_state == TCP_TIME_WAIT) 1790 goto do_time_wait; 1791 1792 if (sk->sk_state == TCP_NEW_SYN_RECV) { 1793 struct request_sock *req = inet_reqsk(sk); 1794 bool req_stolen = false; 1795 struct sock *nsk; 1796 1797 sk = req->rsk_listener; 1798 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 1799 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1800 else 1801 drop_reason = tcp_inbound_hash(sk, req, skb, 1802 &hdr->saddr, &hdr->daddr, 1803 AF_INET6, dif, sdif); 1804 if (drop_reason) { 1805 sk_drops_add(sk, skb); 1806 reqsk_put(req); 1807 goto discard_it; 1808 } 1809 if (tcp_checksum_complete(skb)) { 1810 reqsk_put(req); 1811 goto csum_error; 1812 } 1813 if (unlikely(sk->sk_state != TCP_LISTEN)) { 1814 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb); 1815 if (!nsk) { 1816 inet_csk_reqsk_queue_drop_and_put(sk, req); 1817 goto lookup; 1818 } 1819 sk = nsk; 1820 /* reuseport_migrate_sock() has already held one sk_refcnt 1821 * before returning. 1822 */ 1823 } else { 1824 sock_hold(sk); 1825 } 1826 refcounted = true; 1827 nsk = NULL; 1828 if (!tcp_filter(sk, skb)) { 1829 th = (const struct tcphdr *)skb->data; 1830 hdr = ipv6_hdr(skb); 1831 tcp_v6_fill_cb(skb, hdr, th); 1832 nsk = tcp_check_req(sk, skb, req, false, &req_stolen); 1833 } else { 1834 drop_reason = SKB_DROP_REASON_SOCKET_FILTER; 1835 } 1836 if (!nsk) { 1837 reqsk_put(req); 1838 if (req_stolen) { 1839 /* Another cpu got exclusive access to req 1840 * and created a full blown socket. 1841 * Try to feed this packet to this socket 1842 * instead of discarding it. 1843 */ 1844 tcp_v6_restore_cb(skb); 1845 sock_put(sk); 1846 goto lookup; 1847 } 1848 goto discard_and_relse; 1849 } 1850 nf_reset_ct(skb); 1851 if (nsk == sk) { 1852 reqsk_put(req); 1853 tcp_v6_restore_cb(skb); 1854 } else { 1855 drop_reason = tcp_child_process(sk, nsk, skb); 1856 if (drop_reason) { 1857 enum sk_rst_reason rst_reason; 1858 1859 rst_reason = sk_rst_convert_drop_reason(drop_reason); 1860 tcp_v6_send_reset(nsk, skb, rst_reason); 1861 goto discard_and_relse; 1862 } 1863 sock_put(sk); 1864 return 0; 1865 } 1866 } 1867 1868 process: 1869 if (static_branch_unlikely(&ip6_min_hopcount)) { 1870 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ 1871 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) { 1872 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 1873 drop_reason = SKB_DROP_REASON_TCP_MINTTL; 1874 goto discard_and_relse; 1875 } 1876 } 1877 1878 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) { 1879 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1880 goto discard_and_relse; 1881 } 1882 1883 drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr, 1884 AF_INET6, dif, sdif); 1885 if (drop_reason) 1886 goto discard_and_relse; 1887 1888 nf_reset_ct(skb); 1889 1890 if (tcp_filter(sk, skb)) { 1891 drop_reason = SKB_DROP_REASON_SOCKET_FILTER; 1892 goto discard_and_relse; 1893 } 1894 th = (const struct tcphdr *)skb->data; 1895 hdr = ipv6_hdr(skb); 1896 tcp_v6_fill_cb(skb, hdr, th); 1897 1898 skb->dev = NULL; 1899 1900 if (sk->sk_state == TCP_LISTEN) { 1901 ret = tcp_v6_do_rcv(sk, skb); 1902 goto put_and_return; 1903 } 1904 1905 sk_incoming_cpu_update(sk); 1906 1907 bh_lock_sock_nested(sk); 1908 tcp_segs_in(tcp_sk(sk), skb); 1909 ret = 0; 1910 if (!sock_owned_by_user(sk)) { 1911 ret = tcp_v6_do_rcv(sk, skb); 1912 } else { 1913 if (tcp_add_backlog(sk, skb, &drop_reason)) 1914 goto discard_and_relse; 1915 } 1916 bh_unlock_sock(sk); 1917 put_and_return: 1918 if (refcounted) 1919 sock_put(sk); 1920 return ret ? -1 : 0; 1921 1922 no_tcp_socket: 1923 drop_reason = SKB_DROP_REASON_NO_SOCKET; 1924 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 1925 goto discard_it; 1926 1927 tcp_v6_fill_cb(skb, hdr, th); 1928 1929 if (tcp_checksum_complete(skb)) { 1930 csum_error: 1931 drop_reason = SKB_DROP_REASON_TCP_CSUM; 1932 trace_tcp_bad_csum(skb); 1933 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); 1934 bad_packet: 1935 __TCP_INC_STATS(net, TCP_MIB_INERRS); 1936 } else { 1937 tcp_v6_send_reset(NULL, skb, sk_rst_convert_drop_reason(drop_reason)); 1938 } 1939 1940 discard_it: 1941 SKB_DR_OR(drop_reason, NOT_SPECIFIED); 1942 kfree_skb_reason(skb, drop_reason); 1943 return 0; 1944 1945 discard_and_relse: 1946 sk_drops_add(sk, skb); 1947 if (refcounted) 1948 sock_put(sk); 1949 goto discard_it; 1950 1951 do_time_wait: 1952 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1953 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1954 inet_twsk_put(inet_twsk(sk)); 1955 goto discard_it; 1956 } 1957 1958 tcp_v6_fill_cb(skb, hdr, th); 1959 1960 if (tcp_checksum_complete(skb)) { 1961 inet_twsk_put(inet_twsk(sk)); 1962 goto csum_error; 1963 } 1964 1965 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, &isn)) { 1966 case TCP_TW_SYN: 1967 { 1968 struct sock *sk2; 1969 1970 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, 1971 skb, __tcp_hdrlen(th), 1972 &ipv6_hdr(skb)->saddr, th->source, 1973 &ipv6_hdr(skb)->daddr, 1974 ntohs(th->dest), 1975 tcp_v6_iif_l3_slave(skb), 1976 sdif); 1977 if (sk2) { 1978 struct inet_timewait_sock *tw = inet_twsk(sk); 1979 inet_twsk_deschedule_put(tw); 1980 sk = sk2; 1981 tcp_v6_restore_cb(skb); 1982 refcounted = false; 1983 __this_cpu_write(tcp_tw_isn, isn); 1984 goto process; 1985 } 1986 } 1987 /* to ACK */ 1988 fallthrough; 1989 case TCP_TW_ACK: 1990 tcp_v6_timewait_ack(sk, skb); 1991 break; 1992 case TCP_TW_RST: 1993 tcp_v6_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET); 1994 inet_twsk_deschedule_put(inet_twsk(sk)); 1995 goto discard_it; 1996 case TCP_TW_SUCCESS: 1997 ; 1998 } 1999 goto discard_it; 2000 } 2001 2002 void tcp_v6_early_demux(struct sk_buff *skb) 2003 { 2004 struct net *net = dev_net(skb->dev); 2005 const struct ipv6hdr *hdr; 2006 const struct tcphdr *th; 2007 struct sock *sk; 2008 2009 if (skb->pkt_type != PACKET_HOST) 2010 return; 2011 2012 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) 2013 return; 2014 2015 hdr = ipv6_hdr(skb); 2016 th = tcp_hdr(skb); 2017 2018 if (th->doff < sizeof(struct tcphdr) / 4) 2019 return; 2020 2021 /* Note : We use inet6_iif() here, not tcp_v6_iif() */ 2022 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, 2023 &hdr->saddr, th->source, 2024 &hdr->daddr, ntohs(th->dest), 2025 inet6_iif(skb), inet6_sdif(skb)); 2026 if (sk) { 2027 skb->sk = sk; 2028 skb->destructor = sock_edemux; 2029 if (sk_fullsock(sk)) { 2030 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); 2031 2032 if (dst) 2033 dst = dst_check(dst, sk->sk_rx_dst_cookie); 2034 if (dst && 2035 sk->sk_rx_dst_ifindex == skb->skb_iif) 2036 skb_dst_set_noref(skb, dst); 2037 } 2038 } 2039 } 2040 2041 static struct timewait_sock_ops tcp6_timewait_sock_ops = { 2042 .twsk_obj_size = sizeof(struct tcp6_timewait_sock), 2043 .twsk_destructor = tcp_twsk_destructor, 2044 }; 2045 2046 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) 2047 { 2048 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr); 2049 } 2050 2051 const struct inet_connection_sock_af_ops ipv6_specific = { 2052 .queue_xmit = inet6_csk_xmit, 2053 .send_check = tcp_v6_send_check, 2054 .rebuild_header = inet6_sk_rebuild_header, 2055 .sk_rx_dst_set = inet6_sk_rx_dst_set, 2056 .conn_request = tcp_v6_conn_request, 2057 .syn_recv_sock = tcp_v6_syn_recv_sock, 2058 .net_header_len = sizeof(struct ipv6hdr), 2059 .setsockopt = ipv6_setsockopt, 2060 .getsockopt = ipv6_getsockopt, 2061 .addr2sockaddr = inet6_csk_addr2sockaddr, 2062 .sockaddr_len = sizeof(struct sockaddr_in6), 2063 .mtu_reduced = tcp_v6_mtu_reduced, 2064 }; 2065 2066 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2067 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { 2068 #ifdef CONFIG_TCP_MD5SIG 2069 .md5_lookup = tcp_v6_md5_lookup, 2070 .calc_md5_hash = tcp_v6_md5_hash_skb, 2071 .md5_parse = tcp_v6_parse_md5_keys, 2072 #endif 2073 #ifdef CONFIG_TCP_AO 2074 .ao_lookup = tcp_v6_ao_lookup, 2075 .calc_ao_hash = tcp_v6_ao_hash_skb, 2076 .ao_parse = tcp_v6_parse_ao, 2077 .ao_calc_key_sk = tcp_v6_ao_calc_key_sk, 2078 #endif 2079 }; 2080 #endif 2081 2082 /* 2083 * TCP over IPv4 via INET6 API 2084 */ 2085 static const struct inet_connection_sock_af_ops ipv6_mapped = { 2086 .queue_xmit = ip_queue_xmit, 2087 .send_check = tcp_v4_send_check, 2088 .rebuild_header = inet_sk_rebuild_header, 2089 .sk_rx_dst_set = inet_sk_rx_dst_set, 2090 .conn_request = tcp_v6_conn_request, 2091 .syn_recv_sock = tcp_v6_syn_recv_sock, 2092 .net_header_len = sizeof(struct iphdr), 2093 .setsockopt = ipv6_setsockopt, 2094 .getsockopt = ipv6_getsockopt, 2095 .addr2sockaddr = inet6_csk_addr2sockaddr, 2096 .sockaddr_len = sizeof(struct sockaddr_in6), 2097 .mtu_reduced = tcp_v4_mtu_reduced, 2098 }; 2099 2100 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2101 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { 2102 #ifdef CONFIG_TCP_MD5SIG 2103 .md5_lookup = tcp_v4_md5_lookup, 2104 .calc_md5_hash = tcp_v4_md5_hash_skb, 2105 .md5_parse = tcp_v6_parse_md5_keys, 2106 #endif 2107 #ifdef CONFIG_TCP_AO 2108 .ao_lookup = tcp_v6_ao_lookup, 2109 .calc_ao_hash = tcp_v4_ao_hash_skb, 2110 .ao_parse = tcp_v6_parse_ao, 2111 .ao_calc_key_sk = tcp_v4_ao_calc_key_sk, 2112 #endif 2113 }; 2114 #endif 2115 2116 /* NOTE: A lot of things set to zero explicitly by call to 2117 * sk_alloc() so need not be done here. 2118 */ 2119 static int tcp_v6_init_sock(struct sock *sk) 2120 { 2121 struct inet_connection_sock *icsk = inet_csk(sk); 2122 2123 tcp_init_sock(sk); 2124 2125 icsk->icsk_af_ops = &ipv6_specific; 2126 2127 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2128 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; 2129 #endif 2130 2131 return 0; 2132 } 2133 2134 #ifdef CONFIG_PROC_FS 2135 /* Proc filesystem TCPv6 sock list dumping. */ 2136 static void get_openreq6(struct seq_file *seq, 2137 const struct request_sock *req, int i) 2138 { 2139 long ttd = req->rsk_timer.expires - jiffies; 2140 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr; 2141 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr; 2142 2143 if (ttd < 0) 2144 ttd = 0; 2145 2146 seq_printf(seq, 2147 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2148 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n", 2149 i, 2150 src->s6_addr32[0], src->s6_addr32[1], 2151 src->s6_addr32[2], src->s6_addr32[3], 2152 inet_rsk(req)->ir_num, 2153 dest->s6_addr32[0], dest->s6_addr32[1], 2154 dest->s6_addr32[2], dest->s6_addr32[3], 2155 ntohs(inet_rsk(req)->ir_rmt_port), 2156 TCP_SYN_RECV, 2157 0, 0, /* could print option size, but that is af dependent. */ 2158 1, /* timers active (only the expire timer) */ 2159 jiffies_to_clock_t(ttd), 2160 req->num_timeout, 2161 from_kuid_munged(seq_user_ns(seq), 2162 sock_i_uid(req->rsk_listener)), 2163 0, /* non standard timer */ 2164 0, /* open_requests have no inode */ 2165 0, req); 2166 } 2167 2168 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 2169 { 2170 const struct in6_addr *dest, *src; 2171 __u16 destp, srcp; 2172 int timer_active; 2173 unsigned long timer_expires; 2174 const struct inet_sock *inet = inet_sk(sp); 2175 const struct tcp_sock *tp = tcp_sk(sp); 2176 const struct inet_connection_sock *icsk = inet_csk(sp); 2177 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; 2178 int rx_queue; 2179 int state; 2180 2181 dest = &sp->sk_v6_daddr; 2182 src = &sp->sk_v6_rcv_saddr; 2183 destp = ntohs(inet->inet_dport); 2184 srcp = ntohs(inet->inet_sport); 2185 2186 if (icsk->icsk_pending == ICSK_TIME_RETRANS || 2187 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || 2188 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { 2189 timer_active = 1; 2190 timer_expires = icsk->icsk_timeout; 2191 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 2192 timer_active = 4; 2193 timer_expires = icsk->icsk_timeout; 2194 } else if (timer_pending(&sp->sk_timer)) { 2195 timer_active = 2; 2196 timer_expires = sp->sk_timer.expires; 2197 } else { 2198 timer_active = 0; 2199 timer_expires = jiffies; 2200 } 2201 2202 state = inet_sk_state_load(sp); 2203 if (state == TCP_LISTEN) 2204 rx_queue = READ_ONCE(sp->sk_ack_backlog); 2205 else 2206 /* Because we don't lock the socket, 2207 * we might find a transient negative value. 2208 */ 2209 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - 2210 READ_ONCE(tp->copied_seq), 0); 2211 2212 seq_printf(seq, 2213 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2214 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n", 2215 i, 2216 src->s6_addr32[0], src->s6_addr32[1], 2217 src->s6_addr32[2], src->s6_addr32[3], srcp, 2218 dest->s6_addr32[0], dest->s6_addr32[1], 2219 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2220 state, 2221 READ_ONCE(tp->write_seq) - tp->snd_una, 2222 rx_queue, 2223 timer_active, 2224 jiffies_delta_to_clock_t(timer_expires - jiffies), 2225 icsk->icsk_retransmits, 2226 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), 2227 icsk->icsk_probes_out, 2228 sock_i_ino(sp), 2229 refcount_read(&sp->sk_refcnt), sp, 2230 jiffies_to_clock_t(icsk->icsk_rto), 2231 jiffies_to_clock_t(icsk->icsk_ack.ato), 2232 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), 2233 tcp_snd_cwnd(tp), 2234 state == TCP_LISTEN ? 2235 fastopenq->max_qlen : 2236 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) 2237 ); 2238 } 2239 2240 static void get_timewait6_sock(struct seq_file *seq, 2241 struct inet_timewait_sock *tw, int i) 2242 { 2243 long delta = tw->tw_timer.expires - jiffies; 2244 const struct in6_addr *dest, *src; 2245 __u16 destp, srcp; 2246 2247 dest = &tw->tw_v6_daddr; 2248 src = &tw->tw_v6_rcv_saddr; 2249 destp = ntohs(tw->tw_dport); 2250 srcp = ntohs(tw->tw_sport); 2251 2252 seq_printf(seq, 2253 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2254 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 2255 i, 2256 src->s6_addr32[0], src->s6_addr32[1], 2257 src->s6_addr32[2], src->s6_addr32[3], srcp, 2258 dest->s6_addr32[0], dest->s6_addr32[1], 2259 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2260 tw->tw_substate, 0, 0, 2261 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, 2262 refcount_read(&tw->tw_refcnt), tw); 2263 } 2264 2265 static int tcp6_seq_show(struct seq_file *seq, void *v) 2266 { 2267 struct tcp_iter_state *st; 2268 struct sock *sk = v; 2269 2270 if (v == SEQ_START_TOKEN) { 2271 seq_puts(seq, 2272 " sl " 2273 "local_address " 2274 "remote_address " 2275 "st tx_queue rx_queue tr tm->when retrnsmt" 2276 " uid timeout inode\n"); 2277 goto out; 2278 } 2279 st = seq->private; 2280 2281 if (sk->sk_state == TCP_TIME_WAIT) 2282 get_timewait6_sock(seq, v, st->num); 2283 else if (sk->sk_state == TCP_NEW_SYN_RECV) 2284 get_openreq6(seq, v, st->num); 2285 else 2286 get_tcp6_sock(seq, v, st->num); 2287 out: 2288 return 0; 2289 } 2290 2291 static const struct seq_operations tcp6_seq_ops = { 2292 .show = tcp6_seq_show, 2293 .start = tcp_seq_start, 2294 .next = tcp_seq_next, 2295 .stop = tcp_seq_stop, 2296 }; 2297 2298 static struct tcp_seq_afinfo tcp6_seq_afinfo = { 2299 .family = AF_INET6, 2300 }; 2301 2302 int __net_init tcp6_proc_init(struct net *net) 2303 { 2304 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops, 2305 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo)) 2306 return -ENOMEM; 2307 return 0; 2308 } 2309 2310 void tcp6_proc_exit(struct net *net) 2311 { 2312 remove_proc_entry("tcp6", net->proc_net); 2313 } 2314 #endif 2315 2316 struct proto tcpv6_prot = { 2317 .name = "TCPv6", 2318 .owner = THIS_MODULE, 2319 .close = tcp_close, 2320 .pre_connect = tcp_v6_pre_connect, 2321 .connect = tcp_v6_connect, 2322 .disconnect = tcp_disconnect, 2323 .accept = inet_csk_accept, 2324 .ioctl = tcp_ioctl, 2325 .init = tcp_v6_init_sock, 2326 .destroy = tcp_v4_destroy_sock, 2327 .shutdown = tcp_shutdown, 2328 .setsockopt = tcp_setsockopt, 2329 .getsockopt = tcp_getsockopt, 2330 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, 2331 .keepalive = tcp_set_keepalive, 2332 .recvmsg = tcp_recvmsg, 2333 .sendmsg = tcp_sendmsg, 2334 .splice_eof = tcp_splice_eof, 2335 .backlog_rcv = tcp_v6_do_rcv, 2336 .release_cb = tcp_release_cb, 2337 .hash = inet6_hash, 2338 .unhash = inet_unhash, 2339 .get_port = inet_csk_get_port, 2340 .put_port = inet_put_port, 2341 #ifdef CONFIG_BPF_SYSCALL 2342 .psock_update_sk_prot = tcp_bpf_update_proto, 2343 #endif 2344 .enter_memory_pressure = tcp_enter_memory_pressure, 2345 .leave_memory_pressure = tcp_leave_memory_pressure, 2346 .stream_memory_free = tcp_stream_memory_free, 2347 .sockets_allocated = &tcp_sockets_allocated, 2348 2349 .memory_allocated = &tcp_memory_allocated, 2350 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, 2351 2352 .memory_pressure = &tcp_memory_pressure, 2353 .orphan_count = &tcp_orphan_count, 2354 .sysctl_mem = sysctl_tcp_mem, 2355 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), 2356 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), 2357 .max_header = MAX_TCP_HEADER, 2358 .obj_size = sizeof(struct tcp6_sock), 2359 .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6), 2360 .slab_flags = SLAB_TYPESAFE_BY_RCU, 2361 .twsk_prot = &tcp6_timewait_sock_ops, 2362 .rsk_prot = &tcp6_request_sock_ops, 2363 .h.hashinfo = NULL, 2364 .no_autobind = true, 2365 .diag_destroy = tcp_abort, 2366 }; 2367 EXPORT_SYMBOL_GPL(tcpv6_prot); 2368 2369 2370 static struct inet_protosw tcpv6_protosw = { 2371 .type = SOCK_STREAM, 2372 .protocol = IPPROTO_TCP, 2373 .prot = &tcpv6_prot, 2374 .ops = &inet6_stream_ops, 2375 .flags = INET_PROTOSW_PERMANENT | 2376 INET_PROTOSW_ICSK, 2377 }; 2378 2379 static int __net_init tcpv6_net_init(struct net *net) 2380 { 2381 int res; 2382 2383 res = inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, 2384 SOCK_RAW, IPPROTO_TCP, net); 2385 if (!res) 2386 net->ipv6.tcp_sk->sk_clockid = CLOCK_MONOTONIC; 2387 2388 return res; 2389 } 2390 2391 static void __net_exit tcpv6_net_exit(struct net *net) 2392 { 2393 inet_ctl_sock_destroy(net->ipv6.tcp_sk); 2394 } 2395 2396 static struct pernet_operations tcpv6_net_ops = { 2397 .init = tcpv6_net_init, 2398 .exit = tcpv6_net_exit, 2399 }; 2400 2401 int __init tcpv6_init(void) 2402 { 2403 int ret; 2404 2405 net_hotdata.tcpv6_protocol = (struct inet6_protocol) { 2406 .handler = tcp_v6_rcv, 2407 .err_handler = tcp_v6_err, 2408 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 2409 }; 2410 ret = inet6_add_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP); 2411 if (ret) 2412 goto out; 2413 2414 /* register inet6 protocol */ 2415 ret = inet6_register_protosw(&tcpv6_protosw); 2416 if (ret) 2417 goto out_tcpv6_protocol; 2418 2419 ret = register_pernet_subsys(&tcpv6_net_ops); 2420 if (ret) 2421 goto out_tcpv6_protosw; 2422 2423 ret = mptcpv6_init(); 2424 if (ret) 2425 goto out_tcpv6_pernet_subsys; 2426 2427 out: 2428 return ret; 2429 2430 out_tcpv6_pernet_subsys: 2431 unregister_pernet_subsys(&tcpv6_net_ops); 2432 out_tcpv6_protosw: 2433 inet6_unregister_protosw(&tcpv6_protosw); 2434 out_tcpv6_protocol: 2435 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP); 2436 goto out; 2437 } 2438 2439 void tcpv6_exit(void) 2440 { 2441 unregister_pernet_subsys(&tcpv6_net_ops); 2442 inet6_unregister_protosw(&tcpv6_protosw); 2443 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP); 2444 } 2445