net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/inet_common.h>
  63 #include <net/secure_seq.h>
  64 #include <net/tcp_memcontrol.h>
  65 #include <net/busy_poll.h>
  66
  67 #include <linux/proc_fs.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <linux/crypto.h>
  71 #include <linux/scatterlist.h>
  72
  73 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  74 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  75                                       struct request_sock *req);
  76
  77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  78
  79 static const struct inet_connection_sock_af_ops ipv6_mapped;
  80 static const struct inet_connection_sock_af_ops ipv6_specific;
  81 #ifdef CONFIG_TCP_MD5SIG
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  83 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  84 #else
  85 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  86                                                    const struct in6_addr *addr)
  87 {
  88         return NULL;
  89 }
  90 #endif
  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) {
  97                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  98
  99                 dst_hold(dst);
 100                 sk->sk_rx_dst = dst;
 101                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 102                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 103         }
 104 }
 105
 106 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 107 {
 108         return secure_tcpv6_sequence_number(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 int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 115                           int addr_len)
 116 {
 117         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 118         struct inet_sock *inet = inet_sk(sk);
 119         struct inet_connection_sock *icsk = inet_csk(sk);
 120         struct ipv6_pinfo *np = inet6_sk(sk);
 121         struct tcp_sock *tp = tcp_sk(sk);
 122         struct in6_addr *saddr = NULL, *final_p, final;
 123         struct flowi6 fl6;
 124         struct dst_entry *dst;
 125         int addr_type;
 126         int err;
 127
 128         if (addr_len < SIN6_LEN_RFC2133)
 129                 return -EINVAL;
 130
 131         if (usin->sin6_family != AF_INET6)
 132                 return -EAFNOSUPPORT;
 133
 134         memset(&fl6, 0, sizeof(fl6));
 135
 136         if (np->sndflow) {
 137                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 138                 IP6_ECN_flow_init(fl6.flowlabel);
 139                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 140                         struct ip6_flowlabel *flowlabel;
 141                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 142                         if (!flowlabel)
 143                                 return -EINVAL;
 144                         fl6_sock_release(flowlabel);
 145                 }
 146         }
 147
 148         /*
 149          *      connect() to INADDR_ANY means loopback (BSD'ism).
 150          */
 151
 152         if (ipv6_addr_any(&usin->sin6_addr))
 153                 usin->sin6_addr.s6_addr[15] = 0x1;
 154
 155         addr_type = ipv6_addr_type(&usin->sin6_addr);
 156
 157         if (addr_type & IPV6_ADDR_MULTICAST)
 158                 return -ENETUNREACH;
 159
 160         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 161                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 162                     usin->sin6_scope_id) {
 163                         /* If interface is set while binding, indices
 164                          * must coincide.
 165                          */
 166                         if (sk->sk_bound_dev_if &&
 167                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 168                                 return -EINVAL;
 169
 170                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 171                 }
 172
 173                 /* Connect to link-local address requires an interface */
 174                 if (!sk->sk_bound_dev_if)
 175                         return -EINVAL;
 176         }
 177
 178         if (tp->rx_opt.ts_recent_stamp &&
 179             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 180                 tp->rx_opt.ts_recent = 0;
 181                 tp->rx_opt.ts_recent_stamp = 0;
 182                 tp->write_seq = 0;
 183         }
 184
 185         sk->sk_v6_daddr = usin->sin6_addr;
 186         np->flow_label = fl6.flowlabel;
 187
 188         /*
 189          *      TCP over IPv4
 190          */
 191
 192         if (addr_type == IPV6_ADDR_MAPPED) {
 193                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 194                 struct sockaddr_in sin;
 195
 196                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 197
 198                 if (__ipv6_only_sock(sk))
 199                         return -ENETUNREACH;
 200
 201                 sin.sin_family = AF_INET;
 202                 sin.sin_port = usin->sin6_port;
 203                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 204
 205                 icsk->icsk_af_ops = &ipv6_mapped;
 206                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 207 #ifdef CONFIG_TCP_MD5SIG
 208                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 209 #endif
 210
 211                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 212
 213                 if (err) {
 214                         icsk->icsk_ext_hdr_len = exthdrlen;
 215                         icsk->icsk_af_ops = &ipv6_specific;
 216                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 217 #ifdef CONFIG_TCP_MD5SIG
 218                         tp->af_specific = &tcp_sock_ipv6_specific;
 219 #endif
 220                         goto failure;
 221                 }
 222                 np->saddr = sk->sk_v6_rcv_saddr;
 223
 224                 return err;
 225         }
 226
 227         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 228                 saddr = &sk->sk_v6_rcv_saddr;
 229
 230         fl6.flowi6_proto = IPPROTO_TCP;
 231         fl6.daddr = sk->sk_v6_daddr;
 232         fl6.saddr = saddr ? *saddr : np->saddr;
 233         fl6.flowi6_oif = sk->sk_bound_dev_if;
 234         fl6.flowi6_mark = sk->sk_mark;
 235         fl6.fl6_dport = usin->sin6_port;
 236         fl6.fl6_sport = inet->inet_sport;
 237
 238         final_p = fl6_update_dst(&fl6, np->opt, &final);
 239
 240         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 241
 242         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 243         if (IS_ERR(dst)) {
 244                 err = PTR_ERR(dst);
 245                 goto failure;
 246         }
 247
 248         if (!saddr) {
 249                 saddr = &fl6.saddr;
 250                 sk->sk_v6_rcv_saddr = *saddr;
 251         }
 252
 253         /* set the source address */
 254         np->saddr = *saddr;
 255         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 256
 257         sk->sk_gso_type = SKB_GSO_TCPV6;
 258         __ip6_dst_store(sk, dst, NULL, NULL);
 259
 260         if (tcp_death_row.sysctl_tw_recycle &&
 261             !tp->rx_opt.ts_recent_stamp &&
 262             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 263                 tcp_fetch_timewait_stamp(sk, dst);
 264
 265         icsk->icsk_ext_hdr_len = 0;
 266         if (np->opt)
 267                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 268                                           np->opt->opt_nflen);
 269
 270         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 271
 272         inet->inet_dport = usin->sin6_port;
 273
 274         tcp_set_state(sk, TCP_SYN_SENT);
 275         err = inet6_hash_connect(&tcp_death_row, sk);
 276         if (err)
 277                 goto late_failure;
 278
 279         sk_set_txhash(sk);
 280
 281         if (!tp->write_seq && likely(!tp->repair))
 282                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 283                                                              sk->sk_v6_daddr.s6_addr32,
 284                                                              inet->inet_sport,
 285                                                              inet->inet_dport);
 286
 287         err = tcp_connect(sk);
 288         if (err)
 289                 goto late_failure;
 290
 291         return 0;
 292
 293 late_failure:
 294         tcp_set_state(sk, TCP_CLOSE);
 295         __sk_dst_reset(sk);
 296 failure:
 297         inet->inet_dport = 0;
 298         sk->sk_route_caps = 0;
 299         return err;
 300 }
 301
 302 static void tcp_v6_mtu_reduced(struct sock *sk)
 303 {
 304         struct dst_entry *dst;
 305
 306         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 307                 return;
 308
 309         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 310         if (!dst)
 311                 return;
 312
 313         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 314                 tcp_sync_mss(sk, dst_mtu(dst));
 315                 tcp_simple_retransmit(sk);
 316         }
 317 }
 318
 319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 320                 u8 type, u8 code, int offset, __be32 info)
 321 {
 322         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 324         struct net *net = dev_net(skb->dev);
 325         struct request_sock *fastopen;
 326         struct ipv6_pinfo *np;
 327         struct tcp_sock *tp;
 328         __u32 seq, snd_una;
 329         struct sock *sk;
 330         int err;
 331
 332         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 333                                         &hdr->daddr, th->dest,
 334                                         &hdr->saddr, ntohs(th->source),
 335                                         skb->dev->ifindex);
 336
 337         if (!sk) {
 338                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 339                                    ICMP6_MIB_INERRORS);
 340                 return;
 341         }
 342
 343         if (sk->sk_state == TCP_TIME_WAIT) {
 344                 inet_twsk_put(inet_twsk(sk));
 345                 return;
 346         }
 347         seq = ntohl(th->seq);
 348         if (sk->sk_state == TCP_NEW_SYN_RECV)
 349                 return tcp_req_err(sk, seq);
 350
 351         bh_lock_sock(sk);
 352         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 353                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 354
 355         if (sk->sk_state == TCP_CLOSE)
 356                 goto out;
 357
 358         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 359                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 360                 goto out;
 361         }
 362
 363         tp = tcp_sk(sk);
 364         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 365         fastopen = tp->fastopen_rsk;
 366         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 367         if (sk->sk_state != TCP_LISTEN &&
 368             !between(seq, snd_una, tp->snd_nxt)) {
 369                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 370                 goto out;
 371         }
 372
 373         np = inet6_sk(sk);
 374
 375         if (type == NDISC_REDIRECT) {
 376                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 377
 378                 if (dst)
 379                         dst->ops->redirect(dst, sk, skb);
 380                 goto out;
 381         }
 382
 383         if (type == ICMPV6_PKT_TOOBIG) {
 384                 /* We are not interested in TCP_LISTEN and open_requests
 385                  * (SYN-ACKs send out by Linux are always <576bytes so
 386                  * they should go through unfragmented).
 387                  */
 388                 if (sk->sk_state == TCP_LISTEN)
 389                         goto out;
 390
 391                 if (!ip6_sk_accept_pmtu(sk))
 392                         goto out;
 393
 394                 tp->mtu_info = ntohl(info);
 395                 if (!sock_owned_by_user(sk))
 396                         tcp_v6_mtu_reduced(sk);
 397                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 398                                            &tp->tsq_flags))
 399                         sock_hold(sk);
 400                 goto out;
 401         }
 402
 403         icmpv6_err_convert(type, code, &err);
 404
 405         /* Might be for an request_sock */
 406         switch (sk->sk_state) {
 407         case TCP_SYN_SENT:
 408         case TCP_SYN_RECV:
 409                 /* Only in fast or simultaneous open. If a fast open socket is
 410                  * is already accepted it is treated as a connected one below.
 411                  */
 412                 if (fastopen && !fastopen->sk)
 413                         break;
 414
 415                 if (!sock_owned_by_user(sk)) {
 416                         sk->sk_err = err;
 417                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 418
 419                         tcp_done(sk);
 420                 } else
 421                         sk->sk_err_soft = err;
 422                 goto out;
 423         }
 424
 425         if (!sock_owned_by_user(sk) && np->recverr) {
 426                 sk->sk_err = err;
 427                 sk->sk_error_report(sk);
 428         } else
 429                 sk->sk_err_soft = err;
 430
 431 out:
 432         bh_unlock_sock(sk);
 433         sock_put(sk);
 434 }
 435
 436
 437 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
 438                               struct flowi *fl,
 439                               struct request_sock *req,
 440                               u16 queue_mapping,
 441                               struct tcp_fastopen_cookie *foc)
 442 {
 443         struct inet_request_sock *ireq = inet_rsk(req);
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct flowi6 *fl6 = &fl->u.ip6;
 446         struct sk_buff *skb;
 447         int err = -ENOMEM;
 448
 449         /* First, grab a route. */
 450         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
 451                 goto done;
 452
 453         skb = tcp_make_synack(sk, dst, req, foc);
 454
 455         if (skb) {
 456                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 457                                     &ireq->ir_v6_rmt_addr);
 458
 459                 fl6->daddr = ireq->ir_v6_rmt_addr;
 460                 if (np->repflow && ireq->pktopts)
 461                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 462
 463                 skb_set_queue_mapping(skb, queue_mapping);
 464                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 465                 err = net_xmit_eval(err);
 466         }
 467
 468 done:
 469         return err;
 470 }
 471
 472
 473 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 474 {
 475         kfree_skb(inet_rsk(req)->pktopts);
 476 }
 477
 478 #ifdef CONFIG_TCP_MD5SIG
 479 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 480                                                    const struct in6_addr *addr)
 481 {
 482         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 483 }
 484
 485 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 486                                                 const struct sock *addr_sk)
 487 {
 488         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 489 }
 490
 491 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 492                                  int optlen)
 493 {
 494         struct tcp_md5sig cmd;
 495         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 496
 497         if (optlen < sizeof(cmd))
 498                 return -EINVAL;
 499
 500         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 501                 return -EFAULT;
 502
 503         if (sin6->sin6_family != AF_INET6)
 504                 return -EINVAL;
 505
 506         if (!cmd.tcpm_keylen) {
 507                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 508                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 509                                               AF_INET);
 510                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 511                                       AF_INET6);
 512         }
 513
 514         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 515                 return -EINVAL;
 516
 517         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 518                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 519                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 520
 521         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 522                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 523 }
 524
 525 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 526                                         const struct in6_addr *daddr,
 527                                         const struct in6_addr *saddr, int nbytes)
 528 {
 529         struct tcp6_pseudohdr *bp;
 530         struct scatterlist sg;
 531
 532         bp = &hp->md5_blk.ip6;
 533         /* 1. TCP pseudo-header (RFC2460) */
 534         bp->saddr = *saddr;
 535         bp->daddr = *daddr;
 536         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 537         bp->len = cpu_to_be32(nbytes);
 538
 539         sg_init_one(&sg, bp, sizeof(*bp));
 540         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 541 }
 542
 543 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 544                                const struct in6_addr *daddr, struct in6_addr *saddr,
 545                                const struct tcphdr *th)
 546 {
 547         struct tcp_md5sig_pool *hp;
 548         struct hash_desc *desc;
 549
 550         hp = tcp_get_md5sig_pool();
 551         if (!hp)
 552                 goto clear_hash_noput;
 553         desc = &hp->md5_desc;
 554
 555         if (crypto_hash_init(desc))
 556                 goto clear_hash;
 557         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 558                 goto clear_hash;
 559         if (tcp_md5_hash_header(hp, th))
 560                 goto clear_hash;
 561         if (tcp_md5_hash_key(hp, key))
 562                 goto clear_hash;
 563         if (crypto_hash_final(desc, md5_hash))
 564                 goto clear_hash;
 565
 566         tcp_put_md5sig_pool();
 567         return 0;
 568
 569 clear_hash:
 570         tcp_put_md5sig_pool();
 571 clear_hash_noput:
 572         memset(md5_hash, 0, 16);
 573         return 1;
 574 }
 575
 576 static int tcp_v6_md5_hash_skb(char *md5_hash,
 577                                const struct tcp_md5sig_key *key,
 578                                const struct sock *sk,
 579                                const struct sk_buff *skb)
 580 {
 581         const struct in6_addr *saddr, *daddr;
 582         struct tcp_md5sig_pool *hp;
 583         struct hash_desc *desc;
 584         const struct tcphdr *th = tcp_hdr(skb);
 585
 586         if (sk) { /* valid for establish/request sockets */
 587                 saddr = &sk->sk_v6_rcv_saddr;
 588                 daddr = &sk->sk_v6_daddr;
 589         } else {
 590                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 591                 saddr = &ip6h->saddr;
 592                 daddr = &ip6h->daddr;
 593         }
 594
 595         hp = tcp_get_md5sig_pool();
 596         if (!hp)
 597                 goto clear_hash_noput;
 598         desc = &hp->md5_desc;
 599
 600         if (crypto_hash_init(desc))
 601                 goto clear_hash;
 602
 603         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 604                 goto clear_hash;
 605         if (tcp_md5_hash_header(hp, th))
 606                 goto clear_hash;
 607         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 608                 goto clear_hash;
 609         if (tcp_md5_hash_key(hp, key))
 610                 goto clear_hash;
 611         if (crypto_hash_final(desc, md5_hash))
 612                 goto clear_hash;
 613
 614         tcp_put_md5sig_pool();
 615         return 0;
 616
 617 clear_hash:
 618         tcp_put_md5sig_pool();
 619 clear_hash_noput:
 620         memset(md5_hash, 0, 16);
 621         return 1;
 622 }
 623
 624 static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 625 {
 626         const __u8 *hash_location = NULL;
 627         struct tcp_md5sig_key *hash_expected;
 628         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 629         const struct tcphdr *th = tcp_hdr(skb);
 630         int genhash;
 631         u8 newhash[16];
 632
 633         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 634         hash_location = tcp_parse_md5sig_option(th);
 635
 636         /* We've parsed the options - do we have a hash? */
 637         if (!hash_expected && !hash_location)
 638                 return false;
 639
 640         if (hash_expected && !hash_location) {
 641                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 642                 return true;
 643         }
 644
 645         if (!hash_expected && hash_location) {
 646                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 647                 return true;
 648         }
 649
 650         /* check the signature */
 651         genhash = tcp_v6_md5_hash_skb(newhash,
 652                                       hash_expected,
 653                                       NULL, skb);
 654
 655         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 656                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 657                                      genhash ? "failed" : "mismatch",
 658                                      &ip6h->saddr, ntohs(th->source),
 659                                      &ip6h->daddr, ntohs(th->dest));
 660                 return true;
 661         }
 662         return false;
 663 }
 664 #endif
 665
 666 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
 667                             struct sk_buff *skb)
 668 {
 669         struct inet_request_sock *ireq = inet_rsk(req);
 670         struct ipv6_pinfo *np = inet6_sk(sk);
 671
 672         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 673         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 674
 675         /* So that link locals have meaning */
 676         if (!sk->sk_bound_dev_if &&
 677             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 678                 ireq->ir_iif = tcp_v6_iif(skb);
 679
 680         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 681             (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
 682              np->rxopt.bits.rxinfo ||
 683              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 684              np->rxopt.bits.rxohlim || np->repflow)) {
 685                 atomic_inc(&skb->users);
 686                 ireq->pktopts = skb;
 687         }
 688 }
 689
 690 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 691                                           const struct request_sock *req,
 692                                           bool *strict)
 693 {
 694         if (strict)
 695                 *strict = true;
 696         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 697 }
 698
 699 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 700         .family         =       AF_INET6,
 701         .obj_size       =       sizeof(struct tcp6_request_sock),
 702         .rtx_syn_ack    =       tcp_rtx_synack,
 703         .send_ack       =       tcp_v6_reqsk_send_ack,
 704         .destructor     =       tcp_v6_reqsk_destructor,
 705         .send_reset     =       tcp_v6_send_reset,
 706         .syn_ack_timeout =      tcp_syn_ack_timeout,
 707 };
 708
 709 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 710         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 711                                 sizeof(struct ipv6hdr),
 712 #ifdef CONFIG_TCP_MD5SIG
 713         .req_md5_lookup =       tcp_v6_md5_lookup,
 714         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 715 #endif
 716         .init_req       =       tcp_v6_init_req,
 717 #ifdef CONFIG_SYN_COOKIES
 718         .cookie_init_seq =      cookie_v6_init_sequence,
 719 #endif
 720         .route_req      =       tcp_v6_route_req,
 721         .init_seq       =       tcp_v6_init_sequence,
 722         .send_synack    =       tcp_v6_send_synack,
 723         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 724 };
 725
 726 static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
 727                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 728                                  int oif, struct tcp_md5sig_key *key, int rst,
 729                                  u8 tclass, u32 label)
 730 {
 731         const struct tcphdr *th = tcp_hdr(skb);
 732         struct tcphdr *t1;
 733         struct sk_buff *buff;
 734         struct flowi6 fl6;
 735         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 736         struct sock *ctl_sk = net->ipv6.tcp_sk;
 737         unsigned int tot_len = sizeof(struct tcphdr);
 738         struct dst_entry *dst;
 739         __be32 *topt;
 740
 741         if (tsecr)
 742                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 743 #ifdef CONFIG_TCP_MD5SIG
 744         if (key)
 745                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 746 #endif
 747
 748         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 749                          GFP_ATOMIC);
 750         if (!buff)
 751                 return;
 752
 753         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 754
 755         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 756         skb_reset_transport_header(buff);
 757
 758         /* Swap the send and the receive. */
 759         memset(t1, 0, sizeof(*t1));
 760         t1->dest = th->source;
 761         t1->source = th->dest;
 762         t1->doff = tot_len / 4;
 763         t1->seq = htonl(seq);
 764         t1->ack_seq = htonl(ack);
 765         t1->ack = !rst || !th->ack;
 766         t1->rst = rst;
 767         t1->window = htons(win);
 768
 769         topt = (__be32 *)(t1 + 1);
 770
 771         if (tsecr) {
 772                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 773                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 774                 *topt++ = htonl(tsval);
 775                 *topt++ = htonl(tsecr);
 776         }
 777
 778 #ifdef CONFIG_TCP_MD5SIG
 779         if (key) {
 780                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 781                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 782                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 783                                     &ipv6_hdr(skb)->saddr,
 784                                     &ipv6_hdr(skb)->daddr, t1);
 785         }
 786 #endif
 787
 788         memset(&fl6, 0, sizeof(fl6));
 789         fl6.daddr = ipv6_hdr(skb)->saddr;
 790         fl6.saddr = ipv6_hdr(skb)->daddr;
 791         fl6.flowlabel = label;
 792
 793         buff->ip_summed = CHECKSUM_PARTIAL;
 794         buff->csum = 0;
 795
 796         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 797
 798         fl6.flowi6_proto = IPPROTO_TCP;
 799         if (rt6_need_strict(&fl6.daddr) && !oif)
 800                 fl6.flowi6_oif = tcp_v6_iif(skb);
 801         else
 802                 fl6.flowi6_oif = oif;
 803         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 804         fl6.fl6_dport = t1->dest;
 805         fl6.fl6_sport = t1->source;
 806         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 807
 808         /* Pass a socket to ip6_dst_lookup either it is for RST
 809          * Underlying function will use this to retrieve the network
 810          * namespace
 811          */
 812         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 813         if (!IS_ERR(dst)) {
 814                 skb_dst_set(buff, dst);
 815                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 816                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 817                 if (rst)
 818                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 819                 return;
 820         }
 821
 822         kfree_skb(buff);
 823 }
 824
 825 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 826 {
 827         const struct tcphdr *th = tcp_hdr(skb);
 828         u32 seq = 0, ack_seq = 0;
 829         struct tcp_md5sig_key *key = NULL;
 830 #ifdef CONFIG_TCP_MD5SIG
 831         const __u8 *hash_location = NULL;
 832         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 833         unsigned char newhash[16];
 834         int genhash;
 835         struct sock *sk1 = NULL;
 836 #endif
 837         int oif;
 838
 839         if (th->rst)
 840                 return;
 841
 842         /* If sk not NULL, it means we did a successful lookup and incoming
 843          * route had to be correct. prequeue might have dropped our dst.
 844          */
 845         if (!sk && !ipv6_unicast_destination(skb))
 846                 return;
 847
 848 #ifdef CONFIG_TCP_MD5SIG
 849         hash_location = tcp_parse_md5sig_option(th);
 850         if (!sk && hash_location) {
 851                 /*
 852                  * active side is lost. Try to find listening socket through
 853                  * source port, and then find md5 key through listening socket.
 854                  * we are not loose security here:
 855                  * Incoming packet is checked with md5 hash with finding key,
 856                  * no RST generated if md5 hash doesn't match.
 857                  */
 858                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 859                                            &tcp_hashinfo, &ipv6h->saddr,
 860                                            th->source, &ipv6h->daddr,
 861                                            ntohs(th->source), tcp_v6_iif(skb));
 862                 if (!sk1)
 863                         return;
 864
 865                 rcu_read_lock();
 866                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 867                 if (!key)
 868                         goto release_sk1;
 869
 870                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 871                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 872                         goto release_sk1;
 873         } else {
 874                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 875         }
 876 #endif
 877
 878         if (th->ack)
 879                 seq = ntohl(th->ack_seq);
 880         else
 881                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 882                           (th->doff << 2);
 883
 884         oif = sk ? sk->sk_bound_dev_if : 0;
 885         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 886
 887 #ifdef CONFIG_TCP_MD5SIG
 888 release_sk1:
 889         if (sk1) {
 890                 rcu_read_unlock();
 891                 sock_put(sk1);
 892         }
 893 #endif
 894 }
 895
 896 static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, u32 seq,
 897                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 898                             struct tcp_md5sig_key *key, u8 tclass,
 899                             u32 label)
 900 {
 901         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 902                              tclass, label);
 903 }
 904
 905 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 906 {
 907         struct inet_timewait_sock *tw = inet_twsk(sk);
 908         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 909
 910         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 911                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 912                         tcp_time_stamp + tcptw->tw_ts_offset,
 913                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 914                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 915
 916         inet_twsk_put(tw);
 917 }
 918
 919 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 920                                   struct request_sock *req)
 921 {
 922         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 923          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 924          */
 925         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 926                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 927                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 928                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 929                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 930                         0, 0);
 931 }
 932
 933
 934 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 935 {
 936         const struct tcphdr *th = tcp_hdr(skb);
 937         struct request_sock *req;
 938         struct sock *nsk;
 939
 940         /* Find possible connection requests. */
 941         req = inet6_csk_search_req(sk, th->source,
 942                                    &ipv6_hdr(skb)->saddr,
 943                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 944         if (req) {
 945                 nsk = tcp_check_req(sk, skb, req, false);
 946                 if (!nsk || nsk == sk)
 947                         reqsk_put(req);
 948                 return nsk;
 949         }
 950         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 951                                          &ipv6_hdr(skb)->saddr, th->source,
 952                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 953                                          tcp_v6_iif(skb));
 954
 955         if (nsk) {
 956                 if (nsk->sk_state != TCP_TIME_WAIT) {
 957                         bh_lock_sock(nsk);
 958                         return nsk;
 959                 }
 960                 inet_twsk_put(inet_twsk(nsk));
 961                 return NULL;
 962         }
 963
 964 #ifdef CONFIG_SYN_COOKIES
 965         if (!th->syn)
 966                 sk = cookie_v6_check(sk, skb);
 967 #endif
 968         return sk;
 969 }
 970
 971 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 972 {
 973         if (skb->protocol == htons(ETH_P_IP))
 974                 return tcp_v4_conn_request(sk, skb);
 975
 976         if (!ipv6_unicast_destination(skb))
 977                 goto drop;
 978
 979         return tcp_conn_request(&tcp6_request_sock_ops,
 980                                 &tcp_request_sock_ipv6_ops, sk, skb);
 981
 982 drop:
 983         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 984         return 0; /* don't send reset */
 985 }
 986
 987 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 988                                          struct request_sock *req,
 989                                          struct dst_entry *dst)
 990 {
 991         struct inet_request_sock *ireq;
 992         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 993         struct tcp6_sock *newtcp6sk;
 994         struct inet_sock *newinet;
 995         struct tcp_sock *newtp;
 996         struct sock *newsk;
 997 #ifdef CONFIG_TCP_MD5SIG
 998         struct tcp_md5sig_key *key;
 999 #endif
1000         struct flowi6 fl6;
1001
1002         if (skb->protocol == htons(ETH_P_IP)) {
1003                 /*
1004                  *      v6 mapped
1005                  */
1006
1007                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1008
1009                 if (!newsk)
1010                         return NULL;
1011
1012                 newtcp6sk = (struct tcp6_sock *)newsk;
1013                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1014
1015                 newinet = inet_sk(newsk);
1016                 newnp = inet6_sk(newsk);
1017                 newtp = tcp_sk(newsk);
1018
1019                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1020
1021                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1022
1023                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1024                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1025 #ifdef CONFIG_TCP_MD5SIG
1026                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1027 #endif
1028
1029                 newnp->ipv6_ac_list = NULL;
1030                 newnp->ipv6_fl_list = NULL;
1031                 newnp->pktoptions  = NULL;
1032                 newnp->opt         = NULL;
1033                 newnp->mcast_oif   = tcp_v6_iif(skb);
1034                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1035                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1036                 if (np->repflow)
1037                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1038
1039                 /*
1040                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1041                  * here, tcp_create_openreq_child now does this for us, see the comment in
1042                  * that function for the gory details. -acme
1043                  */
1044
1045                 /* It is tricky place. Until this moment IPv4 tcp
1046                    worked with IPv6 icsk.icsk_af_ops.
1047                    Sync it now.
1048                  */
1049                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1050
1051                 return newsk;
1052         }
1053
1054         ireq = inet_rsk(req);
1055
1056         if (sk_acceptq_is_full(sk))
1057                 goto out_overflow;
1058
1059         if (!dst) {
1060                 dst = inet6_csk_route_req(sk, &fl6, req);
1061                 if (!dst)
1062                         goto out;
1063         }
1064
1065         newsk = tcp_create_openreq_child(sk, req, skb);
1066         if (!newsk)
1067                 goto out_nonewsk;
1068
1069         /*
1070          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1071          * count here, tcp_create_openreq_child now does this for us, see the
1072          * comment in that function for the gory details. -acme
1073          */
1074
1075         newsk->sk_gso_type = SKB_GSO_TCPV6;
1076         __ip6_dst_store(newsk, dst, NULL, NULL);
1077         inet6_sk_rx_dst_set(newsk, skb);
1078
1079         newtcp6sk = (struct tcp6_sock *)newsk;
1080         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1081
1082         newtp = tcp_sk(newsk);
1083         newinet = inet_sk(newsk);
1084         newnp = inet6_sk(newsk);
1085
1086         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1087
1088         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1089         newnp->saddr = ireq->ir_v6_loc_addr;
1090         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1091         newsk->sk_bound_dev_if = ireq->ir_iif;
1092
1093         sk_set_txhash(newsk);
1094
1095         /* Now IPv6 options...
1096
1097            First: no IPv4 options.
1098          */
1099         newinet->inet_opt = NULL;
1100         newnp->ipv6_ac_list = NULL;
1101         newnp->ipv6_fl_list = NULL;
1102
1103         /* Clone RX bits */
1104         newnp->rxopt.all = np->rxopt.all;
1105
1106         /* Clone pktoptions received with SYN */
1107         newnp->pktoptions = NULL;
1108         if (ireq->pktopts) {
1109                 newnp->pktoptions = skb_clone(ireq->pktopts,
1110                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1111                 consume_skb(ireq->pktopts);
1112                 ireq->pktopts = NULL;
1113                 if (newnp->pktoptions)
1114                         skb_set_owner_r(newnp->pktoptions, newsk);
1115         }
1116         newnp->opt        = NULL;
1117         newnp->mcast_oif  = tcp_v6_iif(skb);
1118         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1119         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1120         if (np->repflow)
1121                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1122
1123         /* Clone native IPv6 options from listening socket (if any)
1124
1125            Yes, keeping reference count would be much more clever,
1126            but we make one more one thing there: reattach optmem
1127            to newsk.
1128          */
1129         if (np->opt)
1130                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1131
1132         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1133         if (newnp->opt)
1134                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1135                                                      newnp->opt->opt_flen);
1136
1137         tcp_ca_openreq_child(newsk, dst);
1138
1139         tcp_sync_mss(newsk, dst_mtu(dst));
1140         newtp->advmss = dst_metric_advmss(dst);
1141         if (tcp_sk(sk)->rx_opt.user_mss &&
1142             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1143                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1144
1145         tcp_initialize_rcv_mss(newsk);
1146
1147         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1148         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1149
1150 #ifdef CONFIG_TCP_MD5SIG
1151         /* Copy over the MD5 key from the original socket */
1152         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1153         if (key) {
1154                 /* We're using one, so create a matching key
1155                  * on the newsk structure. If we fail to get
1156                  * memory, then we end up not copying the key
1157                  * across. Shucks.
1158                  */
1159                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1160                                AF_INET6, key->key, key->keylen,
1161                                sk_gfp_atomic(sk, GFP_ATOMIC));
1162         }
1163 #endif
1164
1165         if (__inet_inherit_port(sk, newsk) < 0) {
1166                 inet_csk_prepare_forced_close(newsk);
1167                 tcp_done(newsk);
1168                 goto out;
1169         }
1170         __inet_hash(newsk, NULL);
1171
1172         return newsk;
1173
1174 out_overflow:
1175         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1176 out_nonewsk:
1177         dst_release(dst);
1178 out:
1179         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1180         return NULL;
1181 }
1182
1183 /* The socket must have it's spinlock held when we get
1184  * here.
1185  *
1186  * We have a potential double-lock case here, so even when
1187  * doing backlog processing we use the BH locking scheme.
1188  * This is because we cannot sleep with the original spinlock
1189  * held.
1190  */
1191 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1192 {
1193         struct ipv6_pinfo *np = inet6_sk(sk);
1194         struct tcp_sock *tp;
1195         struct sk_buff *opt_skb = NULL;
1196
1197         /* Imagine: socket is IPv6. IPv4 packet arrives,
1198            goes to IPv4 receive handler and backlogged.
1199            From backlog it always goes here. Kerboom...
1200            Fortunately, tcp_rcv_established and rcv_established
1201            handle them correctly, but it is not case with
1202            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1203          */
1204
1205         if (skb->protocol == htons(ETH_P_IP))
1206                 return tcp_v4_do_rcv(sk, skb);
1207
1208         if (sk_filter(sk, skb))
1209                 goto discard;
1210
1211         /*
1212          *      socket locking is here for SMP purposes as backlog rcv
1213          *      is currently called with bh processing disabled.
1214          */
1215
1216         /* Do Stevens' IPV6_PKTOPTIONS.
1217
1218            Yes, guys, it is the only place in our code, where we
1219            may make it not affecting IPv4.
1220            The rest of code is protocol independent,
1221            and I do not like idea to uglify IPv4.
1222
1223            Actually, all the idea behind IPV6_PKTOPTIONS
1224            looks not very well thought. For now we latch
1225            options, received in the last packet, enqueued
1226            by tcp. Feel free to propose better solution.
1227                                                --ANK (980728)
1228          */
1229         if (np->rxopt.all)
1230                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1231
1232         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1233                 struct dst_entry *dst = sk->sk_rx_dst;
1234
1235                 sock_rps_save_rxhash(sk, skb);
1236                 sk_mark_napi_id(sk, skb);
1237                 if (dst) {
1238                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1239                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1240                                 dst_release(dst);
1241                                 sk->sk_rx_dst = NULL;
1242                         }
1243                 }
1244
1245                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1246                 if (opt_skb)
1247                         goto ipv6_pktoptions;
1248                 return 0;
1249         }
1250
1251         if (tcp_checksum_complete(skb))
1252                 goto csum_err;
1253
1254         if (sk->sk_state == TCP_LISTEN) {
1255                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1256                 if (!nsk)
1257                         goto discard;
1258
1259                 /*
1260                  * Queue it on the new socket if the new socket is active,
1261                  * otherwise we just shortcircuit this and continue with
1262                  * the new socket..
1263                  */
1264                 if (nsk != sk) {
1265                         sock_rps_save_rxhash(nsk, skb);
1266                         sk_mark_napi_id(sk, skb);
1267                         if (tcp_child_process(sk, nsk, skb))
1268                                 goto reset;
1269                         if (opt_skb)
1270                                 __kfree_skb(opt_skb);
1271                         return 0;
1272                 }
1273         } else
1274                 sock_rps_save_rxhash(sk, skb);
1275
1276         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1277                 goto reset;
1278         if (opt_skb)
1279                 goto ipv6_pktoptions;
1280         return 0;
1281
1282 reset:
1283         tcp_v6_send_reset(sk, skb);
1284 discard:
1285         if (opt_skb)
1286                 __kfree_skb(opt_skb);
1287         kfree_skb(skb);
1288         return 0;
1289 csum_err:
1290         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1291         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1292         goto discard;
1293
1294
1295 ipv6_pktoptions:
1296         /* Do you ask, what is it?
1297
1298            1. skb was enqueued by tcp.
1299            2. skb is added to tail of read queue, rather than out of order.
1300            3. socket is not in passive state.
1301            4. Finally, it really contains options, which user wants to receive.
1302          */
1303         tp = tcp_sk(sk);
1304         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1305             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1306                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1307                         np->mcast_oif = tcp_v6_iif(opt_skb);
1308                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1309                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1310                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1311                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1312                 if (np->repflow)
1313                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1314                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1315                         skb_set_owner_r(opt_skb, sk);
1316                         opt_skb = xchg(&np->pktoptions, opt_skb);
1317                 } else {
1318                         __kfree_skb(opt_skb);
1319                         opt_skb = xchg(&np->pktoptions, NULL);
1320                 }
1321         }
1322
1323         kfree_skb(opt_skb);
1324         return 0;
1325 }
1326
1327 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1328                            const struct tcphdr *th)
1329 {
1330         /* This is tricky: we move IP6CB at its correct location into
1331          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1332          * _decode_session6() uses IP6CB().
1333          * barrier() makes sure compiler won't play aliasing games.
1334          */
1335         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1336                 sizeof(struct inet6_skb_parm));
1337         barrier();
1338
1339         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1340         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1341                                     skb->len - th->doff*4);
1342         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1343         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1344         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1345         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1346         TCP_SKB_CB(skb)->sacked = 0;
1347 }
1348
1349 static void tcp_v6_restore_cb(struct sk_buff *skb)
1350 {
1351         /* We need to move header back to the beginning if xfrm6_policy_check()
1352          * and tcp_v6_fill_cb() are going to be called again.
1353          */
1354         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1355                 sizeof(struct inet6_skb_parm));
1356 }
1357
1358 static int tcp_v6_rcv(struct sk_buff *skb)
1359 {
1360         const struct tcphdr *th;
1361         const struct ipv6hdr *hdr;
1362         struct sock *sk;
1363         int ret;
1364         struct net *net = dev_net(skb->dev);
1365
1366         if (skb->pkt_type != PACKET_HOST)
1367                 goto discard_it;
1368
1369         /*
1370          *      Count it even if it's bad.
1371          */
1372         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1373
1374         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1375                 goto discard_it;
1376
1377         th = tcp_hdr(skb);
1378
1379         if (th->doff < sizeof(struct tcphdr)/4)
1380                 goto bad_packet;
1381         if (!pskb_may_pull(skb, th->doff*4))
1382                 goto discard_it;
1383
1384         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1385                 goto csum_error;
1386
1387         th = tcp_hdr(skb);
1388         hdr = ipv6_hdr(skb);
1389
1390         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1391                                 inet6_iif(skb));
1392         if (!sk)
1393                 goto no_tcp_socket;
1394
1395 process:
1396         if (sk->sk_state == TCP_TIME_WAIT)
1397                 goto do_time_wait;
1398
1399         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1400                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1401                 goto discard_and_relse;
1402         }
1403
1404         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1405                 goto discard_and_relse;
1406
1407         tcp_v6_fill_cb(skb, hdr, th);
1408
1409 #ifdef CONFIG_TCP_MD5SIG
1410         if (tcp_v6_inbound_md5_hash(sk, skb))
1411                 goto discard_and_relse;
1412 #endif
1413
1414         if (sk_filter(sk, skb))
1415                 goto discard_and_relse;
1416
1417         sk_incoming_cpu_update(sk);
1418         skb->dev = NULL;
1419
1420         bh_lock_sock_nested(sk);
1421         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1422         ret = 0;
1423         if (!sock_owned_by_user(sk)) {
1424                 if (!tcp_prequeue(sk, skb))
1425                         ret = tcp_v6_do_rcv(sk, skb);
1426         } else if (unlikely(sk_add_backlog(sk, skb,
1427                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1428                 bh_unlock_sock(sk);
1429                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1430                 goto discard_and_relse;
1431         }
1432         bh_unlock_sock(sk);
1433
1434         sock_put(sk);
1435         return ret ? -1 : 0;
1436
1437 no_tcp_socket:
1438         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1439                 goto discard_it;
1440
1441         tcp_v6_fill_cb(skb, hdr, th);
1442
1443         if (tcp_checksum_complete(skb)) {
1444 csum_error:
1445                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1446 bad_packet:
1447                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1448         } else {
1449                 tcp_v6_send_reset(NULL, skb);
1450         }
1451
1452 discard_it:
1453         kfree_skb(skb);
1454         return 0;
1455
1456 discard_and_relse:
1457         sock_put(sk);
1458         goto discard_it;
1459
1460 do_time_wait:
1461         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1462                 inet_twsk_put(inet_twsk(sk));
1463                 goto discard_it;
1464         }
1465
1466         tcp_v6_fill_cb(skb, hdr, th);
1467
1468         if (tcp_checksum_complete(skb)) {
1469                 inet_twsk_put(inet_twsk(sk));
1470                 goto csum_error;
1471         }
1472
1473         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1474         case TCP_TW_SYN:
1475         {
1476                 struct sock *sk2;
1477
1478                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1479                                             &ipv6_hdr(skb)->saddr, th->source,
1480                                             &ipv6_hdr(skb)->daddr,
1481                                             ntohs(th->dest), tcp_v6_iif(skb));
1482                 if (sk2) {
1483                         struct inet_timewait_sock *tw = inet_twsk(sk);
1484                         inet_twsk_deschedule_put(tw);
1485                         sk = sk2;
1486                         tcp_v6_restore_cb(skb);
1487                         goto process;
1488                 }
1489                 /* Fall through to ACK */
1490         }
1491         case TCP_TW_ACK:
1492                 tcp_v6_timewait_ack(sk, skb);
1493                 break;
1494         case TCP_TW_RST:
1495                 tcp_v6_restore_cb(skb);
1496                 goto no_tcp_socket;
1497         case TCP_TW_SUCCESS:
1498                 ;
1499         }
1500         goto discard_it;
1501 }
1502
1503 static void tcp_v6_early_demux(struct sk_buff *skb)
1504 {
1505         const struct ipv6hdr *hdr;
1506         const struct tcphdr *th;
1507         struct sock *sk;
1508
1509         if (skb->pkt_type != PACKET_HOST)
1510                 return;
1511
1512         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1513                 return;
1514
1515         hdr = ipv6_hdr(skb);
1516         th = tcp_hdr(skb);
1517
1518         if (th->doff < sizeof(struct tcphdr) / 4)
1519                 return;
1520
1521         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1522         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1523                                         &hdr->saddr, th->source,
1524                                         &hdr->daddr, ntohs(th->dest),
1525                                         inet6_iif(skb));
1526         if (sk) {
1527                 skb->sk = sk;
1528                 skb->destructor = sock_edemux;
1529                 if (sk_fullsock(sk)) {
1530                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1531
1532                         if (dst)
1533                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1534                         if (dst &&
1535                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1536                                 skb_dst_set_noref(skb, dst);
1537                 }
1538         }
1539 }
1540
1541 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1542         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1543         .twsk_unique    = tcp_twsk_unique,
1544         .twsk_destructor = tcp_twsk_destructor,
1545 };
1546
1547 static const struct inet_connection_sock_af_ops ipv6_specific = {
1548         .queue_xmit        = inet6_csk_xmit,
1549         .send_check        = tcp_v6_send_check,
1550         .rebuild_header    = inet6_sk_rebuild_header,
1551         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1552         .conn_request      = tcp_v6_conn_request,
1553         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1554         .net_header_len    = sizeof(struct ipv6hdr),
1555         .net_frag_header_len = sizeof(struct frag_hdr),
1556         .setsockopt        = ipv6_setsockopt,
1557         .getsockopt        = ipv6_getsockopt,
1558         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1559         .sockaddr_len      = sizeof(struct sockaddr_in6),
1560         .bind_conflict     = inet6_csk_bind_conflict,
1561 #ifdef CONFIG_COMPAT
1562         .compat_setsockopt = compat_ipv6_setsockopt,
1563         .compat_getsockopt = compat_ipv6_getsockopt,
1564 #endif
1565         .mtu_reduced       = tcp_v6_mtu_reduced,
1566 };
1567
1568 #ifdef CONFIG_TCP_MD5SIG
1569 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1570         .md5_lookup     =       tcp_v6_md5_lookup,
1571         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1572         .md5_parse      =       tcp_v6_parse_md5_keys,
1573 };
1574 #endif
1575
1576 /*
1577  *      TCP over IPv4 via INET6 API
1578  */
1579 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1580         .queue_xmit        = ip_queue_xmit,
1581         .send_check        = tcp_v4_send_check,
1582         .rebuild_header    = inet_sk_rebuild_header,
1583         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1584         .conn_request      = tcp_v6_conn_request,
1585         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1586         .net_header_len    = sizeof(struct iphdr),
1587         .setsockopt        = ipv6_setsockopt,
1588         .getsockopt        = ipv6_getsockopt,
1589         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1590         .sockaddr_len      = sizeof(struct sockaddr_in6),
1591         .bind_conflict     = inet6_csk_bind_conflict,
1592 #ifdef CONFIG_COMPAT
1593         .compat_setsockopt = compat_ipv6_setsockopt,
1594         .compat_getsockopt = compat_ipv6_getsockopt,
1595 #endif
1596         .mtu_reduced       = tcp_v4_mtu_reduced,
1597 };
1598
1599 #ifdef CONFIG_TCP_MD5SIG
1600 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1601         .md5_lookup     =       tcp_v4_md5_lookup,
1602         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1603         .md5_parse      =       tcp_v6_parse_md5_keys,
1604 };
1605 #endif
1606
1607 /* NOTE: A lot of things set to zero explicitly by call to
1608  *       sk_alloc() so need not be done here.
1609  */
1610 static int tcp_v6_init_sock(struct sock *sk)
1611 {
1612         struct inet_connection_sock *icsk = inet_csk(sk);
1613
1614         tcp_init_sock(sk);
1615
1616         icsk->icsk_af_ops = &ipv6_specific;
1617
1618 #ifdef CONFIG_TCP_MD5SIG
1619         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1620 #endif
1621
1622         return 0;
1623 }
1624
1625 static void tcp_v6_destroy_sock(struct sock *sk)
1626 {
1627         tcp_v4_destroy_sock(sk);
1628         inet6_destroy_sock(sk);
1629 }
1630
1631 #ifdef CONFIG_PROC_FS
1632 /* Proc filesystem TCPv6 sock list dumping. */
1633 static void get_openreq6(struct seq_file *seq,
1634                          struct request_sock *req, int i, kuid_t uid)
1635 {
1636         long ttd = req->rsk_timer.expires - jiffies;
1637         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1638         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1639
1640         if (ttd < 0)
1641                 ttd = 0;
1642
1643         seq_printf(seq,
1644                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1645                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1646                    i,
1647                    src->s6_addr32[0], src->s6_addr32[1],
1648                    src->s6_addr32[2], src->s6_addr32[3],
1649                    inet_rsk(req)->ir_num,
1650                    dest->s6_addr32[0], dest->s6_addr32[1],
1651                    dest->s6_addr32[2], dest->s6_addr32[3],
1652                    ntohs(inet_rsk(req)->ir_rmt_port),
1653                    TCP_SYN_RECV,
1654                    0, 0, /* could print option size, but that is af dependent. */
1655                    1,   /* timers active (only the expire timer) */
1656                    jiffies_to_clock_t(ttd),
1657                    req->num_timeout,
1658                    from_kuid_munged(seq_user_ns(seq), uid),
1659                    0,  /* non standard timer */
1660                    0, /* open_requests have no inode */
1661                    0, req);
1662 }
1663
1664 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1665 {
1666         const struct in6_addr *dest, *src;
1667         __u16 destp, srcp;
1668         int timer_active;
1669         unsigned long timer_expires;
1670         const struct inet_sock *inet = inet_sk(sp);
1671         const struct tcp_sock *tp = tcp_sk(sp);
1672         const struct inet_connection_sock *icsk = inet_csk(sp);
1673         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1674
1675         dest  = &sp->sk_v6_daddr;
1676         src   = &sp->sk_v6_rcv_saddr;
1677         destp = ntohs(inet->inet_dport);
1678         srcp  = ntohs(inet->inet_sport);
1679
1680         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1681                 timer_active    = 1;
1682                 timer_expires   = icsk->icsk_timeout;
1683         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1684                 timer_active    = 4;
1685                 timer_expires   = icsk->icsk_timeout;
1686         } else if (timer_pending(&sp->sk_timer)) {
1687                 timer_active    = 2;
1688                 timer_expires   = sp->sk_timer.expires;
1689         } else {
1690                 timer_active    = 0;
1691                 timer_expires = jiffies;
1692         }
1693
1694         seq_printf(seq,
1695                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1696                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1697                    i,
1698                    src->s6_addr32[0], src->s6_addr32[1],
1699                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1700                    dest->s6_addr32[0], dest->s6_addr32[1],
1701                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1702                    sp->sk_state,
1703                    tp->write_seq-tp->snd_una,
1704                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1705                    timer_active,
1706                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1707                    icsk->icsk_retransmits,
1708                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1709                    icsk->icsk_probes_out,
1710                    sock_i_ino(sp),
1711                    atomic_read(&sp->sk_refcnt), sp,
1712                    jiffies_to_clock_t(icsk->icsk_rto),
1713                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1714                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1715                    tp->snd_cwnd,
1716                    sp->sk_state == TCP_LISTEN ?
1717                         (fastopenq ? fastopenq->max_qlen : 0) :
1718                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1719                    );
1720 }
1721
1722 static void get_timewait6_sock(struct seq_file *seq,
1723                                struct inet_timewait_sock *tw, int i)
1724 {
1725         long delta = tw->tw_timer.expires - jiffies;
1726         const struct in6_addr *dest, *src;
1727         __u16 destp, srcp;
1728
1729         dest = &tw->tw_v6_daddr;
1730         src  = &tw->tw_v6_rcv_saddr;
1731         destp = ntohs(tw->tw_dport);
1732         srcp  = ntohs(tw->tw_sport);
1733
1734         seq_printf(seq,
1735                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1736                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1737                    i,
1738                    src->s6_addr32[0], src->s6_addr32[1],
1739                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1740                    dest->s6_addr32[0], dest->s6_addr32[1],
1741                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1742                    tw->tw_substate, 0, 0,
1743                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1744                    atomic_read(&tw->tw_refcnt), tw);
1745 }
1746
1747 static int tcp6_seq_show(struct seq_file *seq, void *v)
1748 {
1749         struct tcp_iter_state *st;
1750         struct sock *sk = v;
1751
1752         if (v == SEQ_START_TOKEN) {
1753                 seq_puts(seq,
1754                          "  sl  "
1755                          "local_address                         "
1756                          "remote_address                        "
1757                          "st tx_queue rx_queue tr tm->when retrnsmt"
1758                          "   uid  timeout inode\n");
1759                 goto out;
1760         }
1761         st = seq->private;
1762
1763         switch (st->state) {
1764         case TCP_SEQ_STATE_LISTENING:
1765         case TCP_SEQ_STATE_ESTABLISHED:
1766                 if (sk->sk_state == TCP_TIME_WAIT)
1767                         get_timewait6_sock(seq, v, st->num);
1768                 else
1769                         get_tcp6_sock(seq, v, st->num);
1770                 break;
1771         case TCP_SEQ_STATE_OPENREQ:
1772                 get_openreq6(seq, v, st->num, st->uid);
1773                 break;
1774         }
1775 out:
1776         return 0;
1777 }
1778
1779 static const struct file_operations tcp6_afinfo_seq_fops = {
1780         .owner   = THIS_MODULE,
1781         .open    = tcp_seq_open,
1782         .read    = seq_read,
1783         .llseek  = seq_lseek,
1784         .release = seq_release_net
1785 };
1786
1787 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1788         .name           = "tcp6",
1789         .family         = AF_INET6,
1790         .seq_fops       = &tcp6_afinfo_seq_fops,
1791         .seq_ops        = {
1792                 .show           = tcp6_seq_show,
1793         },
1794 };
1795
1796 int __net_init tcp6_proc_init(struct net *net)
1797 {
1798         return tcp_proc_register(net, &tcp6_seq_afinfo);
1799 }
1800
1801 void tcp6_proc_exit(struct net *net)
1802 {
1803         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1804 }
1805 #endif
1806
1807 static void tcp_v6_clear_sk(struct sock *sk, int size)
1808 {
1809         struct inet_sock *inet = inet_sk(sk);
1810
1811         /* we do not want to clear pinet6 field, because of RCU lookups */
1812         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1813
1814         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1815         memset(&inet->pinet6 + 1, 0, size);
1816 }
1817
1818 struct proto tcpv6_prot = {
1819         .name                   = "TCPv6",
1820         .owner                  = THIS_MODULE,
1821         .close                  = tcp_close,
1822         .connect                = tcp_v6_connect,
1823         .disconnect             = tcp_disconnect,
1824         .accept                 = inet_csk_accept,
1825         .ioctl                  = tcp_ioctl,
1826         .init                   = tcp_v6_init_sock,
1827         .destroy                = tcp_v6_destroy_sock,
1828         .shutdown               = tcp_shutdown,
1829         .setsockopt             = tcp_setsockopt,
1830         .getsockopt             = tcp_getsockopt,
1831         .recvmsg                = tcp_recvmsg,
1832         .sendmsg                = tcp_sendmsg,
1833         .sendpage               = tcp_sendpage,
1834         .backlog_rcv            = tcp_v6_do_rcv,
1835         .release_cb             = tcp_release_cb,
1836         .hash                   = inet_hash,
1837         .unhash                 = inet_unhash,
1838         .get_port               = inet_csk_get_port,
1839         .enter_memory_pressure  = tcp_enter_memory_pressure,
1840         .stream_memory_free     = tcp_stream_memory_free,
1841         .sockets_allocated      = &tcp_sockets_allocated,
1842         .memory_allocated       = &tcp_memory_allocated,
1843         .memory_pressure        = &tcp_memory_pressure,
1844         .orphan_count           = &tcp_orphan_count,
1845         .sysctl_mem             = sysctl_tcp_mem,
1846         .sysctl_wmem            = sysctl_tcp_wmem,
1847         .sysctl_rmem            = sysctl_tcp_rmem,
1848         .max_header             = MAX_TCP_HEADER,
1849         .obj_size               = sizeof(struct tcp6_sock),
1850         .slab_flags             = SLAB_DESTROY_BY_RCU,
1851         .twsk_prot              = &tcp6_timewait_sock_ops,
1852         .rsk_prot               = &tcp6_request_sock_ops,
1853         .h.hashinfo             = &tcp_hashinfo,
1854         .no_autobind            = true,
1855 #ifdef CONFIG_COMPAT
1856         .compat_setsockopt      = compat_tcp_setsockopt,
1857         .compat_getsockopt      = compat_tcp_getsockopt,
1858 #endif
1859 #ifdef CONFIG_MEMCG_KMEM
1860         .proto_cgroup           = tcp_proto_cgroup,
1861 #endif
1862         .clear_sk               = tcp_v6_clear_sk,
1863 };
1864
1865 static const struct inet6_protocol tcpv6_protocol = {
1866         .early_demux    =       tcp_v6_early_demux,
1867         .handler        =       tcp_v6_rcv,
1868         .err_handler    =       tcp_v6_err,
1869         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1870 };
1871
1872 static struct inet_protosw tcpv6_protosw = {
1873         .type           =       SOCK_STREAM,
1874         .protocol       =       IPPROTO_TCP,
1875         .prot           =       &tcpv6_prot,
1876         .ops            =       &inet6_stream_ops,
1877         .flags          =       INET_PROTOSW_PERMANENT |
1878                                 INET_PROTOSW_ICSK,
1879 };
1880
1881 static int __net_init tcpv6_net_init(struct net *net)
1882 {
1883         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1884                                     SOCK_RAW, IPPROTO_TCP, net);
1885 }
1886
1887 static void __net_exit tcpv6_net_exit(struct net *net)
1888 {
1889         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1890 }
1891
1892 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1893 {
1894         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1895 }
1896
1897 static struct pernet_operations tcpv6_net_ops = {
1898         .init       = tcpv6_net_init,
1899         .exit       = tcpv6_net_exit,
1900         .exit_batch = tcpv6_net_exit_batch,
1901 };
1902
1903 int __init tcpv6_init(void)
1904 {
1905         int ret;
1906
1907         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1908         if (ret)
1909                 goto out;
1910
1911         /* register inet6 protocol */
1912         ret = inet6_register_protosw(&tcpv6_protosw);
1913         if (ret)
1914                 goto out_tcpv6_protocol;
1915
1916         ret = register_pernet_subsys(&tcpv6_net_ops);
1917         if (ret)
1918                 goto out_tcpv6_protosw;
1919 out:
1920         return ret;
1921
1922 out_tcpv6_protosw:
1923         inet6_unregister_protosw(&tcpv6_protosw);
1924 out_tcpv6_protocol:
1925         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1926         goto out;
1927 }
1928
1929 void tcpv6_exit(void)
1930 {
1931         unregister_pernet_subsys(&tcpv6_net_ops);
1932         inet6_unregister_protosw(&tcpv6_protosw);
1933         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1934 }