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 INDIRECT_CALLABLE_SCOPE 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 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 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 #endif 83 84 /* Helper returning the inet6 address from a given tcp socket. 85 * It can be used in TCP stack instead of inet6_sk(sk). 86 * This avoids a dereference and allow compiler optimizations. 87 * It is a specialized version of inet6_sk_generic(). 88 */ 89 #define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \ 90 struct tcp6_sock, tcp)->inet6) 91 92 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) 93 { 94 struct dst_entry *dst = skb_dst(skb); 95 96 if (dst && dst_hold_safe(dst)) { 97 const struct rt6_info *rt = (const struct rt6_info *)dst; 98 99 rcu_assign_pointer(sk->sk_rx_dst, dst); 100 sk->sk_rx_dst_ifindex = skb->skb_iif; 101 sk->sk_rx_dst_cookie = rt6_get_cookie(rt); 102 } 103 } 104 105 static u32 tcp_v6_init_seq(const struct sk_buff *skb) 106 { 107 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32, 108 ipv6_hdr(skb)->saddr.s6_addr32, 109 tcp_hdr(skb)->dest, 110 tcp_hdr(skb)->source); 111 } 112 113 static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb) 114 { 115 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32, 116 ipv6_hdr(skb)->saddr.s6_addr32); 117 } 118 119 static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, 120 int addr_len) 121 { 122 /* This check is replicated from tcp_v6_connect() and intended to 123 * prevent BPF program called below from accessing bytes that are out 124 * of the bound specified by user in addr_len. 125 */ 126 if (addr_len < SIN6_LEN_RFC2133) 127 return -EINVAL; 128 129 sock_owned_by_me(sk); 130 131 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len); 132 } 133 134 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 135 int addr_len) 136 { 137 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 138 struct inet_connection_sock *icsk = inet_csk(sk); 139 struct in6_addr *saddr = NULL, *final_p, final; 140 struct inet_timewait_death_row *tcp_death_row; 141 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 142 struct inet_sock *inet = inet_sk(sk); 143 struct tcp_sock *tp = tcp_sk(sk); 144 struct net *net = sock_net(sk); 145 struct ipv6_txoptions *opt; 146 struct dst_entry *dst; 147 struct flowi6 fl6; 148 int addr_type; 149 int err; 150 151 if (addr_len < SIN6_LEN_RFC2133) 152 return -EINVAL; 153 154 if (usin->sin6_family != AF_INET6) 155 return -EAFNOSUPPORT; 156 157 memset(&fl6, 0, sizeof(fl6)); 158 159 if (inet6_test_bit(SNDFLOW, sk)) { 160 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; 161 IP6_ECN_flow_init(fl6.flowlabel); 162 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 163 struct ip6_flowlabel *flowlabel; 164 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 165 if (IS_ERR(flowlabel)) 166 return -EINVAL; 167 fl6_sock_release(flowlabel); 168 } 169 } 170 171 /* 172 * connect() to INADDR_ANY means loopback (BSD'ism). 173 */ 174 175 if (ipv6_addr_any(&usin->sin6_addr)) { 176 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) 177 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 178 &usin->sin6_addr); 179 else 180 usin->sin6_addr = in6addr_loopback; 181 } 182 183 addr_type = ipv6_addr_type(&usin->sin6_addr); 184 185 if (addr_type & IPV6_ADDR_MULTICAST) 186 return -ENETUNREACH; 187 188 if (addr_type&IPV6_ADDR_LINKLOCAL) { 189 if (addr_len >= sizeof(struct sockaddr_in6) && 190 usin->sin6_scope_id) { 191 /* If interface is set while binding, indices 192 * must coincide. 193 */ 194 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) 195 return -EINVAL; 196 197 sk->sk_bound_dev_if = usin->sin6_scope_id; 198 } 199 200 /* Connect to link-local address requires an interface */ 201 if (!sk->sk_bound_dev_if) 202 return -EINVAL; 203 } 204 205 if (tp->rx_opt.ts_recent_stamp && 206 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { 207 tp->rx_opt.ts_recent = 0; 208 tp->rx_opt.ts_recent_stamp = 0; 209 WRITE_ONCE(tp->write_seq, 0); 210 } 211 212 sk->sk_v6_daddr = usin->sin6_addr; 213 np->flow_label = fl6.flowlabel; 214 215 /* 216 * TCP over IPv4 217 */ 218 219 if (addr_type & IPV6_ADDR_MAPPED) { 220 u32 exthdrlen = icsk->icsk_ext_hdr_len; 221 struct sockaddr_in sin; 222 223 if (ipv6_only_sock(sk)) 224 return -ENETUNREACH; 225 226 sin.sin_family = AF_INET; 227 sin.sin_port = usin->sin6_port; 228 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 229 230 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ 231 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped); 232 if (sk_is_mptcp(sk)) 233 mptcpv6_handle_mapped(sk, true); 234 sk->sk_backlog_rcv = tcp_v4_do_rcv; 235 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 236 tp->af_specific = &tcp_sock_ipv6_mapped_specific; 237 #endif 238 239 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 240 241 if (err) { 242 icsk->icsk_ext_hdr_len = exthdrlen; 243 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */ 244 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific); 245 if (sk_is_mptcp(sk)) 246 mptcpv6_handle_mapped(sk, false); 247 sk->sk_backlog_rcv = tcp_v6_do_rcv; 248 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 249 tp->af_specific = &tcp_sock_ipv6_specific; 250 #endif 251 goto failure; 252 } 253 np->saddr = sk->sk_v6_rcv_saddr; 254 255 return err; 256 } 257 258 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 259 saddr = &sk->sk_v6_rcv_saddr; 260 261 fl6.flowi6_proto = IPPROTO_TCP; 262 fl6.daddr = sk->sk_v6_daddr; 263 fl6.saddr = saddr ? *saddr : np->saddr; 264 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label); 265 fl6.flowi6_oif = sk->sk_bound_dev_if; 266 fl6.flowi6_mark = sk->sk_mark; 267 fl6.fl6_dport = usin->sin6_port; 268 fl6.fl6_sport = inet->inet_sport; 269 fl6.flowi6_uid = sk->sk_uid; 270 271 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); 272 final_p = fl6_update_dst(&fl6, opt, &final); 273 274 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); 275 276 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p); 277 if (IS_ERR(dst)) { 278 err = PTR_ERR(dst); 279 goto failure; 280 } 281 282 tp->tcp_usec_ts = dst_tcp_usec_ts(dst); 283 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; 284 285 if (!saddr) { 286 saddr = &fl6.saddr; 287 288 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6); 289 if (err) 290 goto failure; 291 } 292 293 /* set the source address */ 294 np->saddr = *saddr; 295 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 296 297 sk->sk_gso_type = SKB_GSO_TCPV6; 298 ip6_dst_store(sk, dst, NULL, NULL); 299 300 icsk->icsk_ext_hdr_len = 0; 301 if (opt) 302 icsk->icsk_ext_hdr_len = opt->opt_flen + 303 opt->opt_nflen; 304 305 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); 306 307 inet->inet_dport = usin->sin6_port; 308 309 tcp_set_state(sk, TCP_SYN_SENT); 310 err = inet6_hash_connect(tcp_death_row, sk); 311 if (err) 312 goto late_failure; 313 314 sk_set_txhash(sk); 315 316 if (likely(!tp->repair)) { 317 if (!tp->write_seq) 318 WRITE_ONCE(tp->write_seq, 319 secure_tcpv6_seq(np->saddr.s6_addr32, 320 sk->sk_v6_daddr.s6_addr32, 321 inet->inet_sport, 322 inet->inet_dport)); 323 tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32, 324 sk->sk_v6_daddr.s6_addr32); 325 } 326 327 if (tcp_fastopen_defer_connect(sk, &err)) 328 return err; 329 if (err) 330 goto late_failure; 331 332 err = tcp_connect(sk); 333 if (err) 334 goto late_failure; 335 336 return 0; 337 338 late_failure: 339 tcp_set_state(sk, TCP_CLOSE); 340 inet_bhash2_reset_saddr(sk); 341 failure: 342 inet->inet_dport = 0; 343 sk->sk_route_caps = 0; 344 return err; 345 } 346 347 static void tcp_v6_mtu_reduced(struct sock *sk) 348 { 349 struct dst_entry *dst; 350 u32 mtu; 351 352 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) 353 return; 354 355 mtu = READ_ONCE(tcp_sk(sk)->mtu_info); 356 357 /* Drop requests trying to increase our current mss. 358 * Check done in __ip6_rt_update_pmtu() is too late. 359 */ 360 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache) 361 return; 362 363 dst = inet6_csk_update_pmtu(sk, mtu); 364 if (!dst) 365 return; 366 367 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { 368 tcp_sync_mss(sk, dst_mtu(dst)); 369 tcp_simple_retransmit(sk); 370 } 371 } 372 373 static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 374 u8 type, u8 code, int offset, __be32 info) 375 { 376 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 377 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); 378 struct net *net = dev_net(skb->dev); 379 struct request_sock *fastopen; 380 struct ipv6_pinfo *np; 381 struct tcp_sock *tp; 382 __u32 seq, snd_una; 383 struct sock *sk; 384 bool fatal; 385 int err; 386 387 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, 388 &hdr->daddr, th->dest, 389 &hdr->saddr, ntohs(th->source), 390 skb->dev->ifindex, inet6_sdif(skb)); 391 392 if (!sk) { 393 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 394 ICMP6_MIB_INERRORS); 395 return -ENOENT; 396 } 397 398 if (sk->sk_state == TCP_TIME_WAIT) { 399 /* To increase the counter of ignored icmps for TCP-AO */ 400 tcp_ao_ignore_icmp(sk, AF_INET6, type, code); 401 inet_twsk_put(inet_twsk(sk)); 402 return 0; 403 } 404 seq = ntohl(th->seq); 405 fatal = icmpv6_err_convert(type, code, &err); 406 if (sk->sk_state == TCP_NEW_SYN_RECV) { 407 tcp_req_err(sk, seq, fatal); 408 return 0; 409 } 410 411 if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) { 412 sock_put(sk); 413 return 0; 414 } 415 416 bh_lock_sock(sk); 417 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) 418 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); 419 420 if (sk->sk_state == TCP_CLOSE) 421 goto out; 422 423 if (static_branch_unlikely(&ip6_min_hopcount)) { 424 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ 425 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) { 426 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 427 goto out; 428 } 429 } 430 431 tp = tcp_sk(sk); 432 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ 433 fastopen = rcu_dereference(tp->fastopen_rsk); 434 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; 435 if (sk->sk_state != TCP_LISTEN && 436 !between(seq, snd_una, tp->snd_nxt)) { 437 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); 438 goto out; 439 } 440 441 np = tcp_inet6_sk(sk); 442 443 if (type == NDISC_REDIRECT) { 444 if (!sock_owned_by_user(sk)) { 445 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 446 447 if (dst) 448 dst->ops->redirect(dst, sk, skb); 449 } 450 goto out; 451 } 452 453 if (type == ICMPV6_PKT_TOOBIG) { 454 u32 mtu = ntohl(info); 455 456 /* We are not interested in TCP_LISTEN and open_requests 457 * (SYN-ACKs send out by Linux are always <576bytes so 458 * they should go through unfragmented). 459 */ 460 if (sk->sk_state == TCP_LISTEN) 461 goto out; 462 463 if (!ip6_sk_accept_pmtu(sk)) 464 goto out; 465 466 if (mtu < IPV6_MIN_MTU) 467 goto out; 468 469 WRITE_ONCE(tp->mtu_info, mtu); 470 471 if (!sock_owned_by_user(sk)) 472 tcp_v6_mtu_reduced(sk); 473 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, 474 &sk->sk_tsq_flags)) 475 sock_hold(sk); 476 goto out; 477 } 478 479 480 /* Might be for an request_sock */ 481 switch (sk->sk_state) { 482 case TCP_SYN_SENT: 483 case TCP_SYN_RECV: 484 /* Only in fast or simultaneous open. If a fast open socket is 485 * already accepted it is treated as a connected one below. 486 */ 487 if (fastopen && !fastopen->sk) 488 break; 489 490 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th); 491 492 if (!sock_owned_by_user(sk)) { 493 WRITE_ONCE(sk->sk_err, err); 494 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ 495 496 tcp_done(sk); 497 } else { 498 WRITE_ONCE(sk->sk_err_soft, err); 499 } 500 goto out; 501 case TCP_LISTEN: 502 break; 503 default: 504 /* check if this ICMP message allows revert of backoff. 505 * (see RFC 6069) 506 */ 507 if (!fastopen && type == ICMPV6_DEST_UNREACH && 508 code == ICMPV6_NOROUTE) 509 tcp_ld_RTO_revert(sk, seq); 510 } 511 512 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) { 513 WRITE_ONCE(sk->sk_err, err); 514 sk_error_report(sk); 515 } else { 516 WRITE_ONCE(sk->sk_err_soft, err); 517 } 518 out: 519 bh_unlock_sock(sk); 520 sock_put(sk); 521 return 0; 522 } 523 524 525 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, 526 struct flowi *fl, 527 struct request_sock *req, 528 struct tcp_fastopen_cookie *foc, 529 enum tcp_synack_type synack_type, 530 struct sk_buff *syn_skb) 531 { 532 struct inet_request_sock *ireq = inet_rsk(req); 533 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 534 struct ipv6_txoptions *opt; 535 struct flowi6 *fl6 = &fl->u.ip6; 536 struct sk_buff *skb; 537 int err = -ENOMEM; 538 u8 tclass; 539 540 /* First, grab a route. */ 541 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req, 542 IPPROTO_TCP)) == NULL) 543 goto done; 544 545 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); 546 547 if (skb) { 548 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, 549 &ireq->ir_v6_rmt_addr); 550 551 fl6->daddr = ireq->ir_v6_rmt_addr; 552 if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts) 553 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); 554 555 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? 556 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | 557 (np->tclass & INET_ECN_MASK) : 558 np->tclass; 559 560 if (!INET_ECN_is_capable(tclass) && 561 tcp_bpf_ca_needs_ecn((struct sock *)req)) 562 tclass |= INET_ECN_ECT_0; 563 564 rcu_read_lock(); 565 opt = ireq->ipv6_opt; 566 if (!opt) 567 opt = rcu_dereference(np->opt); 568 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark), 569 opt, tclass, READ_ONCE(sk->sk_priority)); 570 rcu_read_unlock(); 571 err = net_xmit_eval(err); 572 } 573 574 done: 575 return err; 576 } 577 578 579 static void tcp_v6_reqsk_destructor(struct request_sock *req) 580 { 581 kfree(inet_rsk(req)->ipv6_opt); 582 consume_skb(inet_rsk(req)->pktopts); 583 } 584 585 #ifdef CONFIG_TCP_MD5SIG 586 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, 587 const struct in6_addr *addr, 588 int l3index) 589 { 590 return tcp_md5_do_lookup(sk, l3index, 591 (union tcp_md5_addr *)addr, AF_INET6); 592 } 593 594 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, 595 const struct sock *addr_sk) 596 { 597 int l3index; 598 599 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), 600 addr_sk->sk_bound_dev_if); 601 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr, 602 l3index); 603 } 604 605 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, 606 sockptr_t optval, int optlen) 607 { 608 struct tcp_md5sig cmd; 609 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; 610 union tcp_ao_addr *addr; 611 int l3index = 0; 612 u8 prefixlen; 613 bool l3flag; 614 u8 flags; 615 616 if (optlen < sizeof(cmd)) 617 return -EINVAL; 618 619 if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) 620 return -EFAULT; 621 622 if (sin6->sin6_family != AF_INET6) 623 return -EINVAL; 624 625 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; 626 l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; 627 628 if (optname == TCP_MD5SIG_EXT && 629 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { 630 prefixlen = cmd.tcpm_prefixlen; 631 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && 632 prefixlen > 32)) 633 return -EINVAL; 634 } else { 635 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; 636 } 637 638 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex && 639 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { 640 struct net_device *dev; 641 642 rcu_read_lock(); 643 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); 644 if (dev && netif_is_l3_master(dev)) 645 l3index = dev->ifindex; 646 rcu_read_unlock(); 647 648 /* ok to reference set/not set outside of rcu; 649 * right now device MUST be an L3 master 650 */ 651 if (!dev || !l3index) 652 return -EINVAL; 653 } 654 655 if (!cmd.tcpm_keylen) { 656 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) 657 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], 658 AF_INET, prefixlen, 659 l3index, flags); 660 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, 661 AF_INET6, prefixlen, l3index, flags); 662 } 663 664 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) 665 return -EINVAL; 666 667 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { 668 addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3]; 669 670 /* Don't allow keys for peers that have a matching TCP-AO key. 671 * See the comment in tcp_ao_add_cmd() 672 */ 673 if (tcp_ao_required(sk, addr, AF_INET, 674 l3flag ? l3index : -1, false)) 675 return -EKEYREJECTED; 676 return tcp_md5_do_add(sk, addr, 677 AF_INET, prefixlen, l3index, flags, 678 cmd.tcpm_key, cmd.tcpm_keylen); 679 } 680 681 addr = (union tcp_md5_addr *)&sin6->sin6_addr; 682 683 /* Don't allow keys for peers that have a matching TCP-AO key. 684 * See the comment in tcp_ao_add_cmd() 685 */ 686 if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false)) 687 return -EKEYREJECTED; 688 689 return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags, 690 cmd.tcpm_key, cmd.tcpm_keylen); 691 } 692 693 static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp, 694 const struct in6_addr *daddr, 695 const struct in6_addr *saddr, 696 const struct tcphdr *th, int nbytes) 697 { 698 struct tcp6_pseudohdr *bp; 699 struct scatterlist sg; 700 struct tcphdr *_th; 701 702 bp = hp->scratch; 703 /* 1. TCP pseudo-header (RFC2460) */ 704 bp->saddr = *saddr; 705 bp->daddr = *daddr; 706 bp->protocol = cpu_to_be32(IPPROTO_TCP); 707 bp->len = cpu_to_be32(nbytes); 708 709 _th = (struct tcphdr *)(bp + 1); 710 memcpy(_th, th, sizeof(*th)); 711 _th->check = 0; 712 713 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); 714 ahash_request_set_crypt(hp->req, &sg, NULL, 715 sizeof(*bp) + sizeof(*th)); 716 return crypto_ahash_update(hp->req); 717 } 718 719 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, 720 const struct in6_addr *daddr, struct in6_addr *saddr, 721 const struct tcphdr *th) 722 { 723 struct tcp_sigpool hp; 724 725 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) 726 goto clear_hash_nostart; 727 728 if (crypto_ahash_init(hp.req)) 729 goto clear_hash; 730 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2)) 731 goto clear_hash; 732 if (tcp_md5_hash_key(&hp, key)) 733 goto clear_hash; 734 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0); 735 if (crypto_ahash_final(hp.req)) 736 goto clear_hash; 737 738 tcp_sigpool_end(&hp); 739 return 0; 740 741 clear_hash: 742 tcp_sigpool_end(&hp); 743 clear_hash_nostart: 744 memset(md5_hash, 0, 16); 745 return 1; 746 } 747 748 static int tcp_v6_md5_hash_skb(char *md5_hash, 749 const struct tcp_md5sig_key *key, 750 const struct sock *sk, 751 const struct sk_buff *skb) 752 { 753 const struct tcphdr *th = tcp_hdr(skb); 754 const struct in6_addr *saddr, *daddr; 755 struct tcp_sigpool hp; 756 757 if (sk) { /* valid for establish/request sockets */ 758 saddr = &sk->sk_v6_rcv_saddr; 759 daddr = &sk->sk_v6_daddr; 760 } else { 761 const struct ipv6hdr *ip6h = ipv6_hdr(skb); 762 saddr = &ip6h->saddr; 763 daddr = &ip6h->daddr; 764 } 765 766 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) 767 goto clear_hash_nostart; 768 769 if (crypto_ahash_init(hp.req)) 770 goto clear_hash; 771 772 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len)) 773 goto clear_hash; 774 if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2)) 775 goto clear_hash; 776 if (tcp_md5_hash_key(&hp, key)) 777 goto clear_hash; 778 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0); 779 if (crypto_ahash_final(hp.req)) 780 goto clear_hash; 781 782 tcp_sigpool_end(&hp); 783 return 0; 784 785 clear_hash: 786 tcp_sigpool_end(&hp); 787 clear_hash_nostart: 788 memset(md5_hash, 0, 16); 789 return 1; 790 } 791 #endif 792 793 static void tcp_v6_init_req(struct request_sock *req, 794 const struct sock *sk_listener, 795 struct sk_buff *skb) 796 { 797 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); 798 struct inet_request_sock *ireq = inet_rsk(req); 799 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener); 800 801 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 802 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 803 804 /* So that link locals have meaning */ 805 if ((!sk_listener->sk_bound_dev_if || l3_slave) && 806 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 807 ireq->ir_iif = tcp_v6_iif(skb); 808 809 if (!TCP_SKB_CB(skb)->tcp_tw_isn && 810 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) || 811 np->rxopt.bits.rxinfo || 812 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || 813 np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) { 814 refcount_inc(&skb->users); 815 ireq->pktopts = skb; 816 } 817 } 818 819 static struct dst_entry *tcp_v6_route_req(const struct sock *sk, 820 struct sk_buff *skb, 821 struct flowi *fl, 822 struct request_sock *req) 823 { 824 tcp_v6_init_req(req, sk, skb); 825 826 if (security_inet_conn_request(sk, skb, req)) 827 return NULL; 828 829 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP); 830 } 831 832 struct request_sock_ops tcp6_request_sock_ops __read_mostly = { 833 .family = AF_INET6, 834 .obj_size = sizeof(struct tcp6_request_sock), 835 .rtx_syn_ack = tcp_rtx_synack, 836 .send_ack = tcp_v6_reqsk_send_ack, 837 .destructor = tcp_v6_reqsk_destructor, 838 .send_reset = tcp_v6_send_reset, 839 .syn_ack_timeout = tcp_syn_ack_timeout, 840 }; 841 842 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { 843 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - 844 sizeof(struct ipv6hdr), 845 #ifdef CONFIG_TCP_MD5SIG 846 .req_md5_lookup = tcp_v6_md5_lookup, 847 .calc_md5_hash = tcp_v6_md5_hash_skb, 848 #endif 849 #ifdef CONFIG_TCP_AO 850 .ao_lookup = tcp_v6_ao_lookup_rsk, 851 .ao_calc_key = tcp_v6_ao_calc_key_rsk, 852 .ao_synack_hash = tcp_v6_ao_synack_hash, 853 #endif 854 #ifdef CONFIG_SYN_COOKIES 855 .cookie_init_seq = cookie_v6_init_sequence, 856 #endif 857 .route_req = tcp_v6_route_req, 858 .init_seq = tcp_v6_init_seq, 859 .init_ts_off = tcp_v6_init_ts_off, 860 .send_synack = tcp_v6_send_synack, 861 }; 862 863 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, 864 u32 ack, u32 win, u32 tsval, u32 tsecr, 865 int oif, int rst, u8 tclass, __be32 label, 866 u32 priority, u32 txhash, struct tcp_key *key) 867 { 868 const struct tcphdr *th = tcp_hdr(skb); 869 struct tcphdr *t1; 870 struct sk_buff *buff; 871 struct flowi6 fl6; 872 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); 873 struct sock *ctl_sk = net->ipv6.tcp_sk; 874 unsigned int tot_len = sizeof(struct tcphdr); 875 __be32 mrst = 0, *topt; 876 struct dst_entry *dst; 877 __u32 mark = 0; 878 879 if (tsecr) 880 tot_len += TCPOLEN_TSTAMP_ALIGNED; 881 if (tcp_key_is_md5(key)) 882 tot_len += TCPOLEN_MD5SIG_ALIGNED; 883 if (tcp_key_is_ao(key)) 884 tot_len += tcp_ao_len_aligned(key->ao_key); 885 886 #ifdef CONFIG_MPTCP 887 if (rst && !tcp_key_is_md5(key)) { 888 mrst = mptcp_reset_option(skb); 889 890 if (mrst) 891 tot_len += sizeof(__be32); 892 } 893 #endif 894 895 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC); 896 if (!buff) 897 return; 898 899 skb_reserve(buff, MAX_TCP_HEADER); 900 901 t1 = skb_push(buff, tot_len); 902 skb_reset_transport_header(buff); 903 904 /* Swap the send and the receive. */ 905 memset(t1, 0, sizeof(*t1)); 906 t1->dest = th->source; 907 t1->source = th->dest; 908 t1->doff = tot_len / 4; 909 t1->seq = htonl(seq); 910 t1->ack_seq = htonl(ack); 911 t1->ack = !rst || !th->ack; 912 t1->rst = rst; 913 t1->window = htons(win); 914 915 topt = (__be32 *)(t1 + 1); 916 917 if (tsecr) { 918 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 919 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); 920 *topt++ = htonl(tsval); 921 *topt++ = htonl(tsecr); 922 } 923 924 if (mrst) 925 *topt++ = mrst; 926 927 #ifdef CONFIG_TCP_MD5SIG 928 if (tcp_key_is_md5(key)) { 929 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | 930 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); 931 tcp_v6_md5_hash_hdr((__u8 *)topt, key->md5_key, 932 &ipv6_hdr(skb)->saddr, 933 &ipv6_hdr(skb)->daddr, t1); 934 } 935 #endif 936 #ifdef CONFIG_TCP_AO 937 if (tcp_key_is_ao(key)) { 938 *topt++ = htonl((TCPOPT_AO << 24) | 939 (tcp_ao_len(key->ao_key) << 16) | 940 (key->ao_key->sndid << 8) | 941 (key->rcv_next)); 942 943 tcp_ao_hash_hdr(AF_INET6, (char *)topt, key->ao_key, 944 key->traffic_key, 945 (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr, 946 (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr, 947 t1, key->sne); 948 } 949 #endif 950 951 memset(&fl6, 0, sizeof(fl6)); 952 fl6.daddr = ipv6_hdr(skb)->saddr; 953 fl6.saddr = ipv6_hdr(skb)->daddr; 954 fl6.flowlabel = label; 955 956 buff->ip_summed = CHECKSUM_PARTIAL; 957 958 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); 959 960 fl6.flowi6_proto = IPPROTO_TCP; 961 if (rt6_need_strict(&fl6.daddr) && !oif) 962 fl6.flowi6_oif = tcp_v6_iif(skb); 963 else { 964 if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) 965 oif = skb->skb_iif; 966 967 fl6.flowi6_oif = oif; 968 } 969 970 if (sk) { 971 if (sk->sk_state == TCP_TIME_WAIT) 972 mark = inet_twsk(sk)->tw_mark; 973 else 974 mark = READ_ONCE(sk->sk_mark); 975 skb_set_delivery_time(buff, tcp_transmit_time(sk), true); 976 } 977 if (txhash) { 978 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */ 979 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4); 980 } 981 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; 982 fl6.fl6_dport = t1->dest; 983 fl6.fl6_sport = t1->source; 984 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); 985 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6)); 986 987 /* Pass a socket to ip6_dst_lookup either it is for RST 988 * Underlying function will use this to retrieve the network 989 * namespace 990 */ 991 if (sk && sk->sk_state != TCP_TIME_WAIT) 992 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/ 993 else 994 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL); 995 if (!IS_ERR(dst)) { 996 skb_dst_set(buff, dst); 997 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, 998 tclass & ~INET_ECN_MASK, priority); 999 TCP_INC_STATS(net, TCP_MIB_OUTSEGS); 1000 if (rst) 1001 TCP_INC_STATS(net, TCP_MIB_OUTRSTS); 1002 return; 1003 } 1004 1005 kfree_skb(buff); 1006 } 1007 1008 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 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 trace_tcp_send_reset(sk, skb); 1116 if (inet6_test_bit(REPFLOW, sk)) 1117 label = ip6_flowlabel(ipv6h); 1118 priority = READ_ONCE(sk->sk_priority); 1119 txhash = sk->sk_txhash; 1120 } 1121 if (sk->sk_state == TCP_TIME_WAIT) { 1122 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); 1123 priority = inet_twsk(sk)->tw_priority; 1124 txhash = inet_twsk(sk)->tw_txhash; 1125 } 1126 } else { 1127 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) 1128 label = ip6_flowlabel(ipv6h); 1129 } 1130 1131 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1, 1132 ipv6_get_dsfield(ipv6h), label, priority, txhash, 1133 &key); 1134 1135 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1136 out: 1137 if (allocated_traffic_key) 1138 kfree(key.traffic_key); 1139 rcu_read_unlock(); 1140 #endif 1141 } 1142 1143 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, 1144 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, 1145 struct tcp_key *key, u8 tclass, 1146 __be32 label, u32 priority, u32 txhash) 1147 { 1148 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0, 1149 tclass, label, priority, txhash, key); 1150 } 1151 1152 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) 1153 { 1154 struct inet_timewait_sock *tw = inet_twsk(sk); 1155 struct tcp_timewait_sock *tcptw = tcp_twsk(sk); 1156 struct tcp_key key = {}; 1157 #ifdef CONFIG_TCP_AO 1158 struct tcp_ao_info *ao_info; 1159 1160 if (static_branch_unlikely(&tcp_ao_needed.key)) { 1161 1162 /* FIXME: the segment to-be-acked is not verified yet */ 1163 ao_info = rcu_dereference(tcptw->ao_info); 1164 if (ao_info) { 1165 const struct tcp_ao_hdr *aoh; 1166 1167 /* Invalid TCP option size or twice included auth */ 1168 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) 1169 goto out; 1170 if (aoh) 1171 key.ao_key = tcp_ao_established_key(ao_info, 1172 aoh->rnext_keyid, -1); 1173 } 1174 } 1175 if (key.ao_key) { 1176 struct tcp_ao_key *rnext_key; 1177 1178 key.traffic_key = snd_other_key(key.ao_key); 1179 /* rcv_next switches to our rcv_next */ 1180 rnext_key = READ_ONCE(ao_info->rnext_key); 1181 key.rcv_next = rnext_key->rcvid; 1182 key.sne = READ_ONCE(ao_info->snd_sne); 1183 key.type = TCP_KEY_AO; 1184 #else 1185 if (0) { 1186 #endif 1187 #ifdef CONFIG_TCP_MD5SIG 1188 } else if (static_branch_unlikely(&tcp_md5_needed.key)) { 1189 key.md5_key = tcp_twsk_md5_key(tcptw); 1190 if (key.md5_key) 1191 key.type = TCP_KEY_MD5; 1192 #endif 1193 } 1194 1195 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, 1196 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, 1197 tcp_tw_tsval(tcptw), 1198 tcptw->tw_ts_recent, tw->tw_bound_dev_if, &key, 1199 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority, 1200 tw->tw_txhash); 1201 1202 #ifdef CONFIG_TCP_AO 1203 out: 1204 #endif 1205 inet_twsk_put(tw); 1206 } 1207 1208 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 1209 struct request_sock *req) 1210 { 1211 struct tcp_key key = {}; 1212 1213 #ifdef CONFIG_TCP_AO 1214 if (static_branch_unlikely(&tcp_ao_needed.key) && 1215 tcp_rsk_used_ao(req)) { 1216 const struct in6_addr *addr = &ipv6_hdr(skb)->saddr; 1217 const struct tcp_ao_hdr *aoh; 1218 int l3index; 1219 1220 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1221 /* Invalid TCP option size or twice included auth */ 1222 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) 1223 return; 1224 if (!aoh) 1225 return; 1226 key.ao_key = tcp_ao_do_lookup(sk, l3index, 1227 (union tcp_ao_addr *)addr, 1228 AF_INET6, aoh->rnext_keyid, -1); 1229 if (unlikely(!key.ao_key)) { 1230 /* Send ACK with any matching MKT for the peer */ 1231 key.ao_key = tcp_ao_do_lookup(sk, l3index, 1232 (union tcp_ao_addr *)addr, 1233 AF_INET6, -1, -1); 1234 /* Matching key disappeared (user removed the key?) 1235 * let the handshake timeout. 1236 */ 1237 if (!key.ao_key) { 1238 net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n", 1239 addr, 1240 ntohs(tcp_hdr(skb)->source), 1241 &ipv6_hdr(skb)->daddr, 1242 ntohs(tcp_hdr(skb)->dest)); 1243 return; 1244 } 1245 } 1246 key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC); 1247 if (!key.traffic_key) 1248 return; 1249 1250 key.type = TCP_KEY_AO; 1251 key.rcv_next = aoh->keyid; 1252 tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req); 1253 #else 1254 if (0) { 1255 #endif 1256 #ifdef CONFIG_TCP_MD5SIG 1257 } else if (static_branch_unlikely(&tcp_md5_needed.key)) { 1258 int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0; 1259 1260 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, 1261 l3index); 1262 if (key.md5_key) 1263 key.type = TCP_KEY_MD5; 1264 #endif 1265 } 1266 1267 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV 1268 * sk->sk_state == TCP_SYN_RECV -> for Fast Open. 1269 */ 1270 /* RFC 7323 2.3 1271 * The window field (SEG.WND) of every outgoing segment, with the 1272 * exception of <SYN> segments, MUST be right-shifted by 1273 * Rcv.Wind.Shift bits: 1274 */ 1275 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ? 1276 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, 1277 tcp_rsk(req)->rcv_nxt, 1278 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, 1279 tcp_rsk_tsval(tcp_rsk(req)), 1280 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if, 1281 &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0, 1282 READ_ONCE(sk->sk_priority), 1283 READ_ONCE(tcp_rsk(req)->txhash)); 1284 if (tcp_key_is_ao(&key)) 1285 kfree(key.traffic_key); 1286 } 1287 1288 1289 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb) 1290 { 1291 #ifdef CONFIG_SYN_COOKIES 1292 const struct tcphdr *th = tcp_hdr(skb); 1293 1294 if (!th->syn) 1295 sk = cookie_v6_check(sk, skb); 1296 #endif 1297 return sk; 1298 } 1299 1300 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, 1301 struct tcphdr *th, u32 *cookie) 1302 { 1303 u16 mss = 0; 1304 #ifdef CONFIG_SYN_COOKIES 1305 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops, 1306 &tcp_request_sock_ipv6_ops, sk, th); 1307 if (mss) { 1308 *cookie = __cookie_v6_init_sequence(iph, th, &mss); 1309 tcp_synq_overflow(sk); 1310 } 1311 #endif 1312 return mss; 1313 } 1314 1315 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 1316 { 1317 if (skb->protocol == htons(ETH_P_IP)) 1318 return tcp_v4_conn_request(sk, skb); 1319 1320 if (!ipv6_unicast_destination(skb)) 1321 goto drop; 1322 1323 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { 1324 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); 1325 return 0; 1326 } 1327 1328 return tcp_conn_request(&tcp6_request_sock_ops, 1329 &tcp_request_sock_ipv6_ops, sk, skb); 1330 1331 drop: 1332 tcp_listendrop(sk); 1333 return 0; /* don't send reset */ 1334 } 1335 1336 static void tcp_v6_restore_cb(struct sk_buff *skb) 1337 { 1338 /* We need to move header back to the beginning if xfrm6_policy_check() 1339 * and tcp_v6_fill_cb() are going to be called again. 1340 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there. 1341 */ 1342 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6, 1343 sizeof(struct inet6_skb_parm)); 1344 } 1345 1346 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, 1347 struct request_sock *req, 1348 struct dst_entry *dst, 1349 struct request_sock *req_unhash, 1350 bool *own_req) 1351 { 1352 struct inet_request_sock *ireq; 1353 struct ipv6_pinfo *newnp; 1354 const struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1355 struct ipv6_txoptions *opt; 1356 struct inet_sock *newinet; 1357 bool found_dup_sk = false; 1358 struct tcp_sock *newtp; 1359 struct sock *newsk; 1360 #ifdef CONFIG_TCP_MD5SIG 1361 struct tcp_md5sig_key *key; 1362 int l3index; 1363 #endif 1364 struct flowi6 fl6; 1365 1366 if (skb->protocol == htons(ETH_P_IP)) { 1367 /* 1368 * v6 mapped 1369 */ 1370 1371 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst, 1372 req_unhash, own_req); 1373 1374 if (!newsk) 1375 return NULL; 1376 1377 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1378 1379 newnp = tcp_inet6_sk(newsk); 1380 newtp = tcp_sk(newsk); 1381 1382 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1383 1384 newnp->saddr = newsk->sk_v6_rcv_saddr; 1385 1386 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; 1387 if (sk_is_mptcp(newsk)) 1388 mptcpv6_handle_mapped(newsk, true); 1389 newsk->sk_backlog_rcv = tcp_v4_do_rcv; 1390 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 1391 newtp->af_specific = &tcp_sock_ipv6_mapped_specific; 1392 #endif 1393 1394 newnp->ipv6_mc_list = NULL; 1395 newnp->ipv6_ac_list = NULL; 1396 newnp->ipv6_fl_list = NULL; 1397 newnp->pktoptions = NULL; 1398 newnp->opt = NULL; 1399 newnp->mcast_oif = inet_iif(skb); 1400 newnp->mcast_hops = ip_hdr(skb)->ttl; 1401 newnp->rcv_flowinfo = 0; 1402 if (inet6_test_bit(REPFLOW, sk)) 1403 newnp->flow_label = 0; 1404 1405 /* 1406 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 1407 * here, tcp_create_openreq_child now does this for us, see the comment in 1408 * that function for the gory details. -acme 1409 */ 1410 1411 /* It is tricky place. Until this moment IPv4 tcp 1412 worked with IPv6 icsk.icsk_af_ops. 1413 Sync it now. 1414 */ 1415 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 1416 1417 return newsk; 1418 } 1419 1420 ireq = inet_rsk(req); 1421 1422 if (sk_acceptq_is_full(sk)) 1423 goto out_overflow; 1424 1425 if (!dst) { 1426 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP); 1427 if (!dst) 1428 goto out; 1429 } 1430 1431 newsk = tcp_create_openreq_child(sk, req, skb); 1432 if (!newsk) 1433 goto out_nonewsk; 1434 1435 /* 1436 * No need to charge this sock to the relevant IPv6 refcnt debug socks 1437 * count here, tcp_create_openreq_child now does this for us, see the 1438 * comment in that function for the gory details. -acme 1439 */ 1440 1441 newsk->sk_gso_type = SKB_GSO_TCPV6; 1442 ip6_dst_store(newsk, dst, NULL, NULL); 1443 inet6_sk_rx_dst_set(newsk, skb); 1444 1445 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); 1446 1447 newtp = tcp_sk(newsk); 1448 newinet = inet_sk(newsk); 1449 newnp = tcp_inet6_sk(newsk); 1450 1451 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 1452 1453 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 1454 newnp->saddr = ireq->ir_v6_loc_addr; 1455 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 1456 newsk->sk_bound_dev_if = ireq->ir_iif; 1457 1458 /* Now IPv6 options... 1459 1460 First: no IPv4 options. 1461 */ 1462 newinet->inet_opt = NULL; 1463 newnp->ipv6_mc_list = NULL; 1464 newnp->ipv6_ac_list = NULL; 1465 newnp->ipv6_fl_list = NULL; 1466 1467 /* Clone RX bits */ 1468 newnp->rxopt.all = np->rxopt.all; 1469 1470 newnp->pktoptions = NULL; 1471 newnp->opt = NULL; 1472 newnp->mcast_oif = tcp_v6_iif(skb); 1473 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 1474 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb)); 1475 if (inet6_test_bit(REPFLOW, sk)) 1476 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); 1477 1478 /* Set ToS of the new socket based upon the value of incoming SYN. 1479 * ECT bits are set later in tcp_init_transfer(). 1480 */ 1481 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) 1482 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; 1483 1484 /* Clone native IPv6 options from listening socket (if any) 1485 1486 Yes, keeping reference count would be much more clever, 1487 but we make one more one thing there: reattach optmem 1488 to newsk. 1489 */ 1490 opt = ireq->ipv6_opt; 1491 if (!opt) 1492 opt = rcu_dereference(np->opt); 1493 if (opt) { 1494 opt = ipv6_dup_options(newsk, opt); 1495 RCU_INIT_POINTER(newnp->opt, opt); 1496 } 1497 inet_csk(newsk)->icsk_ext_hdr_len = 0; 1498 if (opt) 1499 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + 1500 opt->opt_flen; 1501 1502 tcp_ca_openreq_child(newsk, dst); 1503 1504 tcp_sync_mss(newsk, dst_mtu(dst)); 1505 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); 1506 1507 tcp_initialize_rcv_mss(newsk); 1508 1509 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 1510 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 1511 1512 #ifdef CONFIG_TCP_MD5SIG 1513 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); 1514 1515 if (!tcp_rsk_used_ao(req)) { 1516 /* Copy over the MD5 key from the original socket */ 1517 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index); 1518 if (key) { 1519 const union tcp_md5_addr *addr; 1520 1521 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr; 1522 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) { 1523 inet_csk_prepare_forced_close(newsk); 1524 tcp_done(newsk); 1525 goto out; 1526 } 1527 } 1528 } 1529 #endif 1530 #ifdef CONFIG_TCP_AO 1531 /* Copy over tcp_ao_info if any */ 1532 if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6)) 1533 goto out; /* OOM */ 1534 #endif 1535 1536 if (__inet_inherit_port(sk, newsk) < 0) { 1537 inet_csk_prepare_forced_close(newsk); 1538 tcp_done(newsk); 1539 goto out; 1540 } 1541 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), 1542 &found_dup_sk); 1543 if (*own_req) { 1544 tcp_move_syn(newtp, req); 1545 1546 /* Clone pktoptions received with SYN, if we own the req */ 1547 if (ireq->pktopts) { 1548 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk); 1549 consume_skb(ireq->pktopts); 1550 ireq->pktopts = NULL; 1551 if (newnp->pktoptions) 1552 tcp_v6_restore_cb(newnp->pktoptions); 1553 } 1554 } else { 1555 if (!req_unhash && found_dup_sk) { 1556 /* This code path should only be executed in the 1557 * syncookie case only 1558 */ 1559 bh_unlock_sock(newsk); 1560 sock_put(newsk); 1561 newsk = NULL; 1562 } 1563 } 1564 1565 return newsk; 1566 1567 out_overflow: 1568 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 1569 out_nonewsk: 1570 dst_release(dst); 1571 out: 1572 tcp_listendrop(sk); 1573 return NULL; 1574 } 1575 1576 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, 1577 u32)); 1578 /* The socket must have it's spinlock held when we get 1579 * here, unless it is a TCP_LISTEN socket. 1580 * 1581 * We have a potential double-lock case here, so even when 1582 * doing backlog processing we use the BH locking scheme. 1583 * This is because we cannot sleep with the original spinlock 1584 * held. 1585 */ 1586 INDIRECT_CALLABLE_SCOPE 1587 int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 1588 { 1589 struct ipv6_pinfo *np = tcp_inet6_sk(sk); 1590 struct sk_buff *opt_skb = NULL; 1591 enum skb_drop_reason reason; 1592 struct tcp_sock *tp; 1593 1594 /* Imagine: socket is IPv6. IPv4 packet arrives, 1595 goes to IPv4 receive handler and backlogged. 1596 From backlog it always goes here. Kerboom... 1597 Fortunately, tcp_rcv_established and rcv_established 1598 handle them correctly, but it is not case with 1599 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK 1600 */ 1601 1602 if (skb->protocol == htons(ETH_P_IP)) 1603 return tcp_v4_do_rcv(sk, skb); 1604 1605 /* 1606 * socket locking is here for SMP purposes as backlog rcv 1607 * is currently called with bh processing disabled. 1608 */ 1609 1610 /* Do Stevens' IPV6_PKTOPTIONS. 1611 1612 Yes, guys, it is the only place in our code, where we 1613 may make it not affecting IPv4. 1614 The rest of code is protocol independent, 1615 and I do not like idea to uglify IPv4. 1616 1617 Actually, all the idea behind IPV6_PKTOPTIONS 1618 looks not very well thought. For now we latch 1619 options, received in the last packet, enqueued 1620 by tcp. Feel free to propose better solution. 1621 --ANK (980728) 1622 */ 1623 if (np->rxopt.all) 1624 opt_skb = skb_clone_and_charge_r(skb, sk); 1625 1626 reason = SKB_DROP_REASON_NOT_SPECIFIED; 1627 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ 1628 struct dst_entry *dst; 1629 1630 dst = rcu_dereference_protected(sk->sk_rx_dst, 1631 lockdep_sock_is_held(sk)); 1632 1633 sock_rps_save_rxhash(sk, skb); 1634 sk_mark_napi_id(sk, skb); 1635 if (dst) { 1636 if (sk->sk_rx_dst_ifindex != skb->skb_iif || 1637 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check, 1638 dst, sk->sk_rx_dst_cookie) == NULL) { 1639 RCU_INIT_POINTER(sk->sk_rx_dst, NULL); 1640 dst_release(dst); 1641 } 1642 } 1643 1644 tcp_rcv_established(sk, skb); 1645 if (opt_skb) 1646 goto ipv6_pktoptions; 1647 return 0; 1648 } 1649 1650 if (tcp_checksum_complete(skb)) 1651 goto csum_err; 1652 1653 if (sk->sk_state == TCP_LISTEN) { 1654 struct sock *nsk = tcp_v6_cookie_check(sk, skb); 1655 1656 if (!nsk) 1657 goto discard; 1658 1659 if (nsk != sk) { 1660 if (tcp_child_process(sk, nsk, skb)) 1661 goto reset; 1662 if (opt_skb) 1663 __kfree_skb(opt_skb); 1664 return 0; 1665 } 1666 } else 1667 sock_rps_save_rxhash(sk, skb); 1668 1669 if (tcp_rcv_state_process(sk, skb)) 1670 goto reset; 1671 if (opt_skb) 1672 goto ipv6_pktoptions; 1673 return 0; 1674 1675 reset: 1676 tcp_v6_send_reset(sk, skb); 1677 discard: 1678 if (opt_skb) 1679 __kfree_skb(opt_skb); 1680 kfree_skb_reason(skb, reason); 1681 return 0; 1682 csum_err: 1683 reason = SKB_DROP_REASON_TCP_CSUM; 1684 trace_tcp_bad_csum(skb); 1685 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); 1686 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); 1687 goto discard; 1688 1689 1690 ipv6_pktoptions: 1691 /* Do you ask, what is it? 1692 1693 1. skb was enqueued by tcp. 1694 2. skb is added to tail of read queue, rather than out of order. 1695 3. socket is not in passive state. 1696 4. Finally, it really contains options, which user wants to receive. 1697 */ 1698 tp = tcp_sk(sk); 1699 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && 1700 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { 1701 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) 1702 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb)); 1703 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) 1704 WRITE_ONCE(np->mcast_hops, 1705 ipv6_hdr(opt_skb)->hop_limit); 1706 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) 1707 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); 1708 if (inet6_test_bit(REPFLOW, sk)) 1709 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); 1710 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { 1711 tcp_v6_restore_cb(opt_skb); 1712 opt_skb = xchg(&np->pktoptions, opt_skb); 1713 } else { 1714 __kfree_skb(opt_skb); 1715 opt_skb = xchg(&np->pktoptions, NULL); 1716 } 1717 } 1718 1719 consume_skb(opt_skb); 1720 return 0; 1721 } 1722 1723 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, 1724 const struct tcphdr *th) 1725 { 1726 /* This is tricky: we move IP6CB at its correct location into 1727 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because 1728 * _decode_session6() uses IP6CB(). 1729 * barrier() makes sure compiler won't play aliasing games. 1730 */ 1731 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), 1732 sizeof(struct inet6_skb_parm)); 1733 barrier(); 1734 1735 TCP_SKB_CB(skb)->seq = ntohl(th->seq); 1736 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + 1737 skb->len - th->doff*4); 1738 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); 1739 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); 1740 TCP_SKB_CB(skb)->tcp_tw_isn = 0; 1741 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); 1742 TCP_SKB_CB(skb)->sacked = 0; 1743 TCP_SKB_CB(skb)->has_rxtstamp = 1744 skb->tstamp || skb_hwtstamps(skb)->hwtstamp; 1745 } 1746 1747 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) 1748 { 1749 enum skb_drop_reason drop_reason; 1750 int sdif = inet6_sdif(skb); 1751 int dif = inet6_iif(skb); 1752 const struct tcphdr *th; 1753 const struct ipv6hdr *hdr; 1754 bool refcounted; 1755 struct sock *sk; 1756 int ret; 1757 struct net *net = dev_net(skb->dev); 1758 1759 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; 1760 if (skb->pkt_type != PACKET_HOST) 1761 goto discard_it; 1762 1763 /* 1764 * Count it even if it's bad. 1765 */ 1766 __TCP_INC_STATS(net, TCP_MIB_INSEGS); 1767 1768 if (!pskb_may_pull(skb, sizeof(struct tcphdr))) 1769 goto discard_it; 1770 1771 th = (const struct tcphdr *)skb->data; 1772 1773 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { 1774 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; 1775 goto bad_packet; 1776 } 1777 if (!pskb_may_pull(skb, th->doff*4)) 1778 goto discard_it; 1779 1780 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo)) 1781 goto csum_error; 1782 1783 th = (const struct tcphdr *)skb->data; 1784 hdr = ipv6_hdr(skb); 1785 1786 lookup: 1787 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th), 1788 th->source, th->dest, inet6_iif(skb), sdif, 1789 &refcounted); 1790 if (!sk) 1791 goto no_tcp_socket; 1792 1793 process: 1794 if (sk->sk_state == TCP_TIME_WAIT) 1795 goto do_time_wait; 1796 1797 if (sk->sk_state == TCP_NEW_SYN_RECV) { 1798 struct request_sock *req = inet_reqsk(sk); 1799 bool req_stolen = false; 1800 struct sock *nsk; 1801 1802 sk = req->rsk_listener; 1803 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 1804 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1805 else 1806 drop_reason = tcp_inbound_hash(sk, req, skb, 1807 &hdr->saddr, &hdr->daddr, 1808 AF_INET6, dif, sdif); 1809 if (drop_reason) { 1810 sk_drops_add(sk, skb); 1811 reqsk_put(req); 1812 goto discard_it; 1813 } 1814 if (tcp_checksum_complete(skb)) { 1815 reqsk_put(req); 1816 goto csum_error; 1817 } 1818 if (unlikely(sk->sk_state != TCP_LISTEN)) { 1819 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb); 1820 if (!nsk) { 1821 inet_csk_reqsk_queue_drop_and_put(sk, req); 1822 goto lookup; 1823 } 1824 sk = nsk; 1825 /* reuseport_migrate_sock() has already held one sk_refcnt 1826 * before returning. 1827 */ 1828 } else { 1829 sock_hold(sk); 1830 } 1831 refcounted = true; 1832 nsk = NULL; 1833 if (!tcp_filter(sk, skb)) { 1834 th = (const struct tcphdr *)skb->data; 1835 hdr = ipv6_hdr(skb); 1836 tcp_v6_fill_cb(skb, hdr, th); 1837 nsk = tcp_check_req(sk, skb, req, false, &req_stolen); 1838 } else { 1839 drop_reason = SKB_DROP_REASON_SOCKET_FILTER; 1840 } 1841 if (!nsk) { 1842 reqsk_put(req); 1843 if (req_stolen) { 1844 /* Another cpu got exclusive access to req 1845 * and created a full blown socket. 1846 * Try to feed this packet to this socket 1847 * instead of discarding it. 1848 */ 1849 tcp_v6_restore_cb(skb); 1850 sock_put(sk); 1851 goto lookup; 1852 } 1853 goto discard_and_relse; 1854 } 1855 nf_reset_ct(skb); 1856 if (nsk == sk) { 1857 reqsk_put(req); 1858 tcp_v6_restore_cb(skb); 1859 } else if (tcp_child_process(sk, nsk, skb)) { 1860 tcp_v6_send_reset(nsk, skb); 1861 goto discard_and_relse; 1862 } else { 1863 sock_put(sk); 1864 return 0; 1865 } 1866 } 1867 1868 if (static_branch_unlikely(&ip6_min_hopcount)) { 1869 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */ 1870 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) { 1871 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); 1872 drop_reason = SKB_DROP_REASON_TCP_MINTTL; 1873 goto discard_and_relse; 1874 } 1875 } 1876 1877 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) { 1878 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1879 goto discard_and_relse; 1880 } 1881 1882 drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr, 1883 AF_INET6, dif, sdif); 1884 if (drop_reason) 1885 goto discard_and_relse; 1886 1887 nf_reset_ct(skb); 1888 1889 if (tcp_filter(sk, skb)) { 1890 drop_reason = SKB_DROP_REASON_SOCKET_FILTER; 1891 goto discard_and_relse; 1892 } 1893 th = (const struct tcphdr *)skb->data; 1894 hdr = ipv6_hdr(skb); 1895 tcp_v6_fill_cb(skb, hdr, th); 1896 1897 skb->dev = NULL; 1898 1899 if (sk->sk_state == TCP_LISTEN) { 1900 ret = tcp_v6_do_rcv(sk, skb); 1901 goto put_and_return; 1902 } 1903 1904 sk_incoming_cpu_update(sk); 1905 1906 bh_lock_sock_nested(sk); 1907 tcp_segs_in(tcp_sk(sk), skb); 1908 ret = 0; 1909 if (!sock_owned_by_user(sk)) { 1910 ret = tcp_v6_do_rcv(sk, skb); 1911 } else { 1912 if (tcp_add_backlog(sk, skb, &drop_reason)) 1913 goto discard_and_relse; 1914 } 1915 bh_unlock_sock(sk); 1916 put_and_return: 1917 if (refcounted) 1918 sock_put(sk); 1919 return ret ? -1 : 0; 1920 1921 no_tcp_socket: 1922 drop_reason = SKB_DROP_REASON_NO_SOCKET; 1923 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 1924 goto discard_it; 1925 1926 tcp_v6_fill_cb(skb, hdr, th); 1927 1928 if (tcp_checksum_complete(skb)) { 1929 csum_error: 1930 drop_reason = SKB_DROP_REASON_TCP_CSUM; 1931 trace_tcp_bad_csum(skb); 1932 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); 1933 bad_packet: 1934 __TCP_INC_STATS(net, TCP_MIB_INERRS); 1935 } else { 1936 tcp_v6_send_reset(NULL, skb); 1937 } 1938 1939 discard_it: 1940 SKB_DR_OR(drop_reason, NOT_SPECIFIED); 1941 kfree_skb_reason(skb, drop_reason); 1942 return 0; 1943 1944 discard_and_relse: 1945 sk_drops_add(sk, skb); 1946 if (refcounted) 1947 sock_put(sk); 1948 goto discard_it; 1949 1950 do_time_wait: 1951 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 1952 drop_reason = SKB_DROP_REASON_XFRM_POLICY; 1953 inet_twsk_put(inet_twsk(sk)); 1954 goto discard_it; 1955 } 1956 1957 tcp_v6_fill_cb(skb, hdr, th); 1958 1959 if (tcp_checksum_complete(skb)) { 1960 inet_twsk_put(inet_twsk(sk)); 1961 goto csum_error; 1962 } 1963 1964 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { 1965 case TCP_TW_SYN: 1966 { 1967 struct sock *sk2; 1968 1969 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, 1970 skb, __tcp_hdrlen(th), 1971 &ipv6_hdr(skb)->saddr, th->source, 1972 &ipv6_hdr(skb)->daddr, 1973 ntohs(th->dest), 1974 tcp_v6_iif_l3_slave(skb), 1975 sdif); 1976 if (sk2) { 1977 struct inet_timewait_sock *tw = inet_twsk(sk); 1978 inet_twsk_deschedule_put(tw); 1979 sk = sk2; 1980 tcp_v6_restore_cb(skb); 1981 refcounted = false; 1982 goto process; 1983 } 1984 } 1985 /* to ACK */ 1986 fallthrough; 1987 case TCP_TW_ACK: 1988 tcp_v6_timewait_ack(sk, skb); 1989 break; 1990 case TCP_TW_RST: 1991 tcp_v6_send_reset(sk, skb); 1992 inet_twsk_deschedule_put(inet_twsk(sk)); 1993 goto discard_it; 1994 case TCP_TW_SUCCESS: 1995 ; 1996 } 1997 goto discard_it; 1998 } 1999 2000 void tcp_v6_early_demux(struct sk_buff *skb) 2001 { 2002 struct net *net = dev_net(skb->dev); 2003 const struct ipv6hdr *hdr; 2004 const struct tcphdr *th; 2005 struct sock *sk; 2006 2007 if (skb->pkt_type != PACKET_HOST) 2008 return; 2009 2010 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) 2011 return; 2012 2013 hdr = ipv6_hdr(skb); 2014 th = tcp_hdr(skb); 2015 2016 if (th->doff < sizeof(struct tcphdr) / 4) 2017 return; 2018 2019 /* Note : We use inet6_iif() here, not tcp_v6_iif() */ 2020 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, 2021 &hdr->saddr, th->source, 2022 &hdr->daddr, ntohs(th->dest), 2023 inet6_iif(skb), inet6_sdif(skb)); 2024 if (sk) { 2025 skb->sk = sk; 2026 skb->destructor = sock_edemux; 2027 if (sk_fullsock(sk)) { 2028 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); 2029 2030 if (dst) 2031 dst = dst_check(dst, sk->sk_rx_dst_cookie); 2032 if (dst && 2033 sk->sk_rx_dst_ifindex == skb->skb_iif) 2034 skb_dst_set_noref(skb, dst); 2035 } 2036 } 2037 } 2038 2039 static struct timewait_sock_ops tcp6_timewait_sock_ops = { 2040 .twsk_obj_size = sizeof(struct tcp6_timewait_sock), 2041 .twsk_unique = tcp_twsk_unique, 2042 .twsk_destructor = tcp_twsk_destructor, 2043 }; 2044 2045 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb) 2046 { 2047 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr); 2048 } 2049 2050 const struct inet_connection_sock_af_ops ipv6_specific = { 2051 .queue_xmit = inet6_csk_xmit, 2052 .send_check = tcp_v6_send_check, 2053 .rebuild_header = inet6_sk_rebuild_header, 2054 .sk_rx_dst_set = inet6_sk_rx_dst_set, 2055 .conn_request = tcp_v6_conn_request, 2056 .syn_recv_sock = tcp_v6_syn_recv_sock, 2057 .net_header_len = sizeof(struct ipv6hdr), 2058 .setsockopt = ipv6_setsockopt, 2059 .getsockopt = ipv6_getsockopt, 2060 .addr2sockaddr = inet6_csk_addr2sockaddr, 2061 .sockaddr_len = sizeof(struct sockaddr_in6), 2062 .mtu_reduced = tcp_v6_mtu_reduced, 2063 }; 2064 2065 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2066 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { 2067 #ifdef CONFIG_TCP_MD5SIG 2068 .md5_lookup = tcp_v6_md5_lookup, 2069 .calc_md5_hash = tcp_v6_md5_hash_skb, 2070 .md5_parse = tcp_v6_parse_md5_keys, 2071 #endif 2072 #ifdef CONFIG_TCP_AO 2073 .ao_lookup = tcp_v6_ao_lookup, 2074 .calc_ao_hash = tcp_v6_ao_hash_skb, 2075 .ao_parse = tcp_v6_parse_ao, 2076 .ao_calc_key_sk = tcp_v6_ao_calc_key_sk, 2077 #endif 2078 }; 2079 #endif 2080 2081 /* 2082 * TCP over IPv4 via INET6 API 2083 */ 2084 static const struct inet_connection_sock_af_ops ipv6_mapped = { 2085 .queue_xmit = ip_queue_xmit, 2086 .send_check = tcp_v4_send_check, 2087 .rebuild_header = inet_sk_rebuild_header, 2088 .sk_rx_dst_set = inet_sk_rx_dst_set, 2089 .conn_request = tcp_v6_conn_request, 2090 .syn_recv_sock = tcp_v6_syn_recv_sock, 2091 .net_header_len = sizeof(struct iphdr), 2092 .setsockopt = ipv6_setsockopt, 2093 .getsockopt = ipv6_getsockopt, 2094 .addr2sockaddr = inet6_csk_addr2sockaddr, 2095 .sockaddr_len = sizeof(struct sockaddr_in6), 2096 .mtu_reduced = tcp_v4_mtu_reduced, 2097 }; 2098 2099 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2100 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { 2101 #ifdef CONFIG_TCP_MD5SIG 2102 .md5_lookup = tcp_v4_md5_lookup, 2103 .calc_md5_hash = tcp_v4_md5_hash_skb, 2104 .md5_parse = tcp_v6_parse_md5_keys, 2105 #endif 2106 #ifdef CONFIG_TCP_AO 2107 .ao_lookup = tcp_v6_ao_lookup, 2108 .calc_ao_hash = tcp_v4_ao_hash_skb, 2109 .ao_parse = tcp_v6_parse_ao, 2110 .ao_calc_key_sk = tcp_v4_ao_calc_key_sk, 2111 #endif 2112 }; 2113 #endif 2114 2115 /* NOTE: A lot of things set to zero explicitly by call to 2116 * sk_alloc() so need not be done here. 2117 */ 2118 static int tcp_v6_init_sock(struct sock *sk) 2119 { 2120 struct inet_connection_sock *icsk = inet_csk(sk); 2121 2122 tcp_init_sock(sk); 2123 2124 icsk->icsk_af_ops = &ipv6_specific; 2125 2126 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 2127 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; 2128 #endif 2129 2130 return 0; 2131 } 2132 2133 #ifdef CONFIG_PROC_FS 2134 /* Proc filesystem TCPv6 sock list dumping. */ 2135 static void get_openreq6(struct seq_file *seq, 2136 const struct request_sock *req, int i) 2137 { 2138 long ttd = req->rsk_timer.expires - jiffies; 2139 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr; 2140 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr; 2141 2142 if (ttd < 0) 2143 ttd = 0; 2144 2145 seq_printf(seq, 2146 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2147 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n", 2148 i, 2149 src->s6_addr32[0], src->s6_addr32[1], 2150 src->s6_addr32[2], src->s6_addr32[3], 2151 inet_rsk(req)->ir_num, 2152 dest->s6_addr32[0], dest->s6_addr32[1], 2153 dest->s6_addr32[2], dest->s6_addr32[3], 2154 ntohs(inet_rsk(req)->ir_rmt_port), 2155 TCP_SYN_RECV, 2156 0, 0, /* could print option size, but that is af dependent. */ 2157 1, /* timers active (only the expire timer) */ 2158 jiffies_to_clock_t(ttd), 2159 req->num_timeout, 2160 from_kuid_munged(seq_user_ns(seq), 2161 sock_i_uid(req->rsk_listener)), 2162 0, /* non standard timer */ 2163 0, /* open_requests have no inode */ 2164 0, req); 2165 } 2166 2167 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) 2168 { 2169 const struct in6_addr *dest, *src; 2170 __u16 destp, srcp; 2171 int timer_active; 2172 unsigned long timer_expires; 2173 const struct inet_sock *inet = inet_sk(sp); 2174 const struct tcp_sock *tp = tcp_sk(sp); 2175 const struct inet_connection_sock *icsk = inet_csk(sp); 2176 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; 2177 int rx_queue; 2178 int state; 2179 2180 dest = &sp->sk_v6_daddr; 2181 src = &sp->sk_v6_rcv_saddr; 2182 destp = ntohs(inet->inet_dport); 2183 srcp = ntohs(inet->inet_sport); 2184 2185 if (icsk->icsk_pending == ICSK_TIME_RETRANS || 2186 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || 2187 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { 2188 timer_active = 1; 2189 timer_expires = icsk->icsk_timeout; 2190 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 2191 timer_active = 4; 2192 timer_expires = icsk->icsk_timeout; 2193 } else if (timer_pending(&sp->sk_timer)) { 2194 timer_active = 2; 2195 timer_expires = sp->sk_timer.expires; 2196 } else { 2197 timer_active = 0; 2198 timer_expires = jiffies; 2199 } 2200 2201 state = inet_sk_state_load(sp); 2202 if (state == TCP_LISTEN) 2203 rx_queue = READ_ONCE(sp->sk_ack_backlog); 2204 else 2205 /* Because we don't lock the socket, 2206 * we might find a transient negative value. 2207 */ 2208 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - 2209 READ_ONCE(tp->copied_seq), 0); 2210 2211 seq_printf(seq, 2212 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2213 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n", 2214 i, 2215 src->s6_addr32[0], src->s6_addr32[1], 2216 src->s6_addr32[2], src->s6_addr32[3], srcp, 2217 dest->s6_addr32[0], dest->s6_addr32[1], 2218 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2219 state, 2220 READ_ONCE(tp->write_seq) - tp->snd_una, 2221 rx_queue, 2222 timer_active, 2223 jiffies_delta_to_clock_t(timer_expires - jiffies), 2224 icsk->icsk_retransmits, 2225 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), 2226 icsk->icsk_probes_out, 2227 sock_i_ino(sp), 2228 refcount_read(&sp->sk_refcnt), sp, 2229 jiffies_to_clock_t(icsk->icsk_rto), 2230 jiffies_to_clock_t(icsk->icsk_ack.ato), 2231 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), 2232 tcp_snd_cwnd(tp), 2233 state == TCP_LISTEN ? 2234 fastopenq->max_qlen : 2235 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) 2236 ); 2237 } 2238 2239 static void get_timewait6_sock(struct seq_file *seq, 2240 struct inet_timewait_sock *tw, int i) 2241 { 2242 long delta = tw->tw_timer.expires - jiffies; 2243 const struct in6_addr *dest, *src; 2244 __u16 destp, srcp; 2245 2246 dest = &tw->tw_v6_daddr; 2247 src = &tw->tw_v6_rcv_saddr; 2248 destp = ntohs(tw->tw_dport); 2249 srcp = ntohs(tw->tw_sport); 2250 2251 seq_printf(seq, 2252 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " 2253 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 2254 i, 2255 src->s6_addr32[0], src->s6_addr32[1], 2256 src->s6_addr32[2], src->s6_addr32[3], srcp, 2257 dest->s6_addr32[0], dest->s6_addr32[1], 2258 dest->s6_addr32[2], dest->s6_addr32[3], destp, 2259 tw->tw_substate, 0, 0, 2260 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, 2261 refcount_read(&tw->tw_refcnt), tw); 2262 } 2263 2264 static int tcp6_seq_show(struct seq_file *seq, void *v) 2265 { 2266 struct tcp_iter_state *st; 2267 struct sock *sk = v; 2268 2269 if (v == SEQ_START_TOKEN) { 2270 seq_puts(seq, 2271 " sl " 2272 "local_address " 2273 "remote_address " 2274 "st tx_queue rx_queue tr tm->when retrnsmt" 2275 " uid timeout inode\n"); 2276 goto out; 2277 } 2278 st = seq->private; 2279 2280 if (sk->sk_state == TCP_TIME_WAIT) 2281 get_timewait6_sock(seq, v, st->num); 2282 else if (sk->sk_state == TCP_NEW_SYN_RECV) 2283 get_openreq6(seq, v, st->num); 2284 else 2285 get_tcp6_sock(seq, v, st->num); 2286 out: 2287 return 0; 2288 } 2289 2290 static const struct seq_operations tcp6_seq_ops = { 2291 .show = tcp6_seq_show, 2292 .start = tcp_seq_start, 2293 .next = tcp_seq_next, 2294 .stop = tcp_seq_stop, 2295 }; 2296 2297 static struct tcp_seq_afinfo tcp6_seq_afinfo = { 2298 .family = AF_INET6, 2299 }; 2300 2301 int __net_init tcp6_proc_init(struct net *net) 2302 { 2303 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops, 2304 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo)) 2305 return -ENOMEM; 2306 return 0; 2307 } 2308 2309 void tcp6_proc_exit(struct net *net) 2310 { 2311 remove_proc_entry("tcp6", net->proc_net); 2312 } 2313 #endif 2314 2315 struct proto tcpv6_prot = { 2316 .name = "TCPv6", 2317 .owner = THIS_MODULE, 2318 .close = tcp_close, 2319 .pre_connect = tcp_v6_pre_connect, 2320 .connect = tcp_v6_connect, 2321 .disconnect = tcp_disconnect, 2322 .accept = inet_csk_accept, 2323 .ioctl = tcp_ioctl, 2324 .init = tcp_v6_init_sock, 2325 .destroy = tcp_v4_destroy_sock, 2326 .shutdown = tcp_shutdown, 2327 .setsockopt = tcp_setsockopt, 2328 .getsockopt = tcp_getsockopt, 2329 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, 2330 .keepalive = tcp_set_keepalive, 2331 .recvmsg = tcp_recvmsg, 2332 .sendmsg = tcp_sendmsg, 2333 .splice_eof = tcp_splice_eof, 2334 .backlog_rcv = tcp_v6_do_rcv, 2335 .release_cb = tcp_release_cb, 2336 .hash = inet6_hash, 2337 .unhash = inet_unhash, 2338 .get_port = inet_csk_get_port, 2339 .put_port = inet_put_port, 2340 #ifdef CONFIG_BPF_SYSCALL 2341 .psock_update_sk_prot = tcp_bpf_update_proto, 2342 #endif 2343 .enter_memory_pressure = tcp_enter_memory_pressure, 2344 .leave_memory_pressure = tcp_leave_memory_pressure, 2345 .stream_memory_free = tcp_stream_memory_free, 2346 .sockets_allocated = &tcp_sockets_allocated, 2347 2348 .memory_allocated = &tcp_memory_allocated, 2349 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, 2350 2351 .memory_pressure = &tcp_memory_pressure, 2352 .orphan_count = &tcp_orphan_count, 2353 .sysctl_mem = sysctl_tcp_mem, 2354 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), 2355 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), 2356 .max_header = MAX_TCP_HEADER, 2357 .obj_size = sizeof(struct tcp6_sock), 2358 .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6), 2359 .slab_flags = SLAB_TYPESAFE_BY_RCU, 2360 .twsk_prot = &tcp6_timewait_sock_ops, 2361 .rsk_prot = &tcp6_request_sock_ops, 2362 .h.hashinfo = NULL, 2363 .no_autobind = true, 2364 .diag_destroy = tcp_abort, 2365 }; 2366 EXPORT_SYMBOL_GPL(tcpv6_prot); 2367 2368 static const struct inet6_protocol tcpv6_protocol = { 2369 .handler = tcp_v6_rcv, 2370 .err_handler = tcp_v6_err, 2371 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 2372 }; 2373 2374 static struct inet_protosw tcpv6_protosw = { 2375 .type = SOCK_STREAM, 2376 .protocol = IPPROTO_TCP, 2377 .prot = &tcpv6_prot, 2378 .ops = &inet6_stream_ops, 2379 .flags = INET_PROTOSW_PERMANENT | 2380 INET_PROTOSW_ICSK, 2381 }; 2382 2383 static int __net_init tcpv6_net_init(struct net *net) 2384 { 2385 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, 2386 SOCK_RAW, IPPROTO_TCP, net); 2387 } 2388 2389 static void __net_exit tcpv6_net_exit(struct net *net) 2390 { 2391 inet_ctl_sock_destroy(net->ipv6.tcp_sk); 2392 } 2393 2394 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) 2395 { 2396 tcp_twsk_purge(net_exit_list, AF_INET6); 2397 } 2398 2399 static struct pernet_operations tcpv6_net_ops = { 2400 .init = tcpv6_net_init, 2401 .exit = tcpv6_net_exit, 2402 .exit_batch = tcpv6_net_exit_batch, 2403 }; 2404 2405 int __init tcpv6_init(void) 2406 { 2407 int ret; 2408 2409 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); 2410 if (ret) 2411 goto out; 2412 2413 /* register inet6 protocol */ 2414 ret = inet6_register_protosw(&tcpv6_protosw); 2415 if (ret) 2416 goto out_tcpv6_protocol; 2417 2418 ret = register_pernet_subsys(&tcpv6_net_ops); 2419 if (ret) 2420 goto out_tcpv6_protosw; 2421 2422 ret = mptcpv6_init(); 2423 if (ret) 2424 goto out_tcpv6_pernet_subsys; 2425 2426 out: 2427 return ret; 2428 2429 out_tcpv6_pernet_subsys: 2430 unregister_pernet_subsys(&tcpv6_net_ops); 2431 out_tcpv6_protosw: 2432 inet6_unregister_protosw(&tcpv6_protosw); 2433 out_tcpv6_protocol: 2434 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2435 goto out; 2436 } 2437 2438 void tcpv6_exit(void) 2439 { 2440 unregister_pernet_subsys(&tcpv6_net_ops); 2441 inet6_unregister_protosw(&tcpv6_protosw); 2442 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); 2443 } 2444