net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <[email protected]>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/netdma.h>
  63 #include <net/inet_common.h>
  64 #include <net/secure_seq.h>
  65 #include <net/tcp_memcontrol.h>
  66
  67 #include <asm/uaccess.h>
  68
  69 #include <linux/proc_fs.h>
  70 #include <linux/seq_file.h>
  71
  72 #include <linux/crypto.h>
  73 #include <linux/scatterlist.h>
  74
  75 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  76 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  77                                       struct request_sock *req);
  78
  79 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  80
  81 static const struct inet_connection_sock_af_ops ipv6_mapped;
  82 static const struct inet_connection_sock_af_ops ipv6_specific;
  83 #ifdef CONFIG_TCP_MD5SIG
  84 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  85 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  86 #else
  87 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  88                                                    const struct in6_addr *addr)
  89 {
  90         return NULL;
  91 }
  92 #endif
  93
  94 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  95 {
  96         struct dst_entry *dst = skb_dst(skb);
  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         if (rt->rt6i_node)
 103                 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
 104 }
 105
 106 static void tcp_v6_hash(struct sock *sk)
 107 {
 108         if (sk->sk_state != TCP_CLOSE) {
 109                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
 110                         tcp_prot.hash(sk);
 111                         return;
 112                 }
 113                 local_bh_disable();
 114                 __inet6_hash(sk, NULL);
 115                 local_bh_enable();
 116         }
 117 }
 118
 119 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 120 {
 121         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 122                                             ipv6_hdr(skb)->saddr.s6_addr32,
 123                                             tcp_hdr(skb)->dest,
 124                                             tcp_hdr(skb)->source);
 125 }
 126
 127 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 128                           int addr_len)
 129 {
 130         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 131         struct inet_sock *inet = inet_sk(sk);
 132         struct inet_connection_sock *icsk = inet_csk(sk);
 133         struct ipv6_pinfo *np = inet6_sk(sk);
 134         struct tcp_sock *tp = tcp_sk(sk);
 135         struct in6_addr *saddr = NULL, *final_p, final;
 136         struct rt6_info *rt;
 137         struct flowi6 fl6;
 138         struct dst_entry *dst;
 139         int addr_type;
 140         int err;
 141
 142         if (addr_len < SIN6_LEN_RFC2133)
 143                 return -EINVAL;
 144
 145         if (usin->sin6_family != AF_INET6)
 146                 return -EAFNOSUPPORT;
 147
 148         memset(&fl6, 0, sizeof(fl6));
 149
 150         if (np->sndflow) {
 151                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 152                 IP6_ECN_flow_init(fl6.flowlabel);
 153                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 154                         struct ip6_flowlabel *flowlabel;
 155                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 156                         if (flowlabel == NULL)
 157                                 return -EINVAL;
 158                         usin->sin6_addr = flowlabel->dst;
 159                         fl6_sock_release(flowlabel);
 160                 }
 161         }
 162
 163         /*
 164          *      connect() to INADDR_ANY means loopback (BSD'ism).
 165          */
 166
 167         if(ipv6_addr_any(&usin->sin6_addr))
 168                 usin->sin6_addr.s6_addr[15] = 0x1;
 169
 170         addr_type = ipv6_addr_type(&usin->sin6_addr);
 171
 172         if(addr_type & IPV6_ADDR_MULTICAST)
 173                 return -ENETUNREACH;
 174
 175         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 176                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 177                     usin->sin6_scope_id) {
 178                         /* If interface is set while binding, indices
 179                          * must coincide.
 180                          */
 181                         if (sk->sk_bound_dev_if &&
 182                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 183                                 return -EINVAL;
 184
 185                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 186                 }
 187
 188                 /* Connect to link-local address requires an interface */
 189                 if (!sk->sk_bound_dev_if)
 190                         return -EINVAL;
 191         }
 192
 193         if (tp->rx_opt.ts_recent_stamp &&
 194             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 195                 tp->rx_opt.ts_recent = 0;
 196                 tp->rx_opt.ts_recent_stamp = 0;
 197                 tp->write_seq = 0;
 198         }
 199
 200         np->daddr = usin->sin6_addr;
 201         np->flow_label = fl6.flowlabel;
 202
 203         /*
 204          *      TCP over IPv4
 205          */
 206
 207         if (addr_type == IPV6_ADDR_MAPPED) {
 208                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 209                 struct sockaddr_in sin;
 210
 211                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 212
 213                 if (__ipv6_only_sock(sk))
 214                         return -ENETUNREACH;
 215
 216                 sin.sin_family = AF_INET;
 217                 sin.sin_port = usin->sin6_port;
 218                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 219
 220                 icsk->icsk_af_ops = &ipv6_mapped;
 221                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 222 #ifdef CONFIG_TCP_MD5SIG
 223                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 224 #endif
 225
 226                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 227
 228                 if (err) {
 229                         icsk->icsk_ext_hdr_len = exthdrlen;
 230                         icsk->icsk_af_ops = &ipv6_specific;
 231                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 232 #ifdef CONFIG_TCP_MD5SIG
 233                         tp->af_specific = &tcp_sock_ipv6_specific;
 234 #endif
 235                         goto failure;
 236                 } else {
 237                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 238                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 239                                                &np->rcv_saddr);
 240                 }
 241
 242                 return err;
 243         }
 244
 245         if (!ipv6_addr_any(&np->rcv_saddr))
 246                 saddr = &np->rcv_saddr;
 247
 248         fl6.flowi6_proto = IPPROTO_TCP;
 249         fl6.daddr = np->daddr;
 250         fl6.saddr = saddr ? *saddr : np->saddr;
 251         fl6.flowi6_oif = sk->sk_bound_dev_if;
 252         fl6.flowi6_mark = sk->sk_mark;
 253         fl6.fl6_dport = usin->sin6_port;
 254         fl6.fl6_sport = inet->inet_sport;
 255
 256         final_p = fl6_update_dst(&fl6, np->opt, &final);
 257
 258         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 259
 260         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 261         if (IS_ERR(dst)) {
 262                 err = PTR_ERR(dst);
 263                 goto failure;
 264         }
 265
 266         if (saddr == NULL) {
 267                 saddr = &fl6.saddr;
 268                 np->rcv_saddr = *saddr;
 269         }
 270
 271         /* set the source address */
 272         np->saddr = *saddr;
 273         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 274
 275         sk->sk_gso_type = SKB_GSO_TCPV6;
 276         __ip6_dst_store(sk, dst, NULL, NULL);
 277
 278         rt = (struct rt6_info *) dst;
 279         if (tcp_death_row.sysctl_tw_recycle &&
 280             !tp->rx_opt.ts_recent_stamp &&
 281             ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr))
 282                 tcp_fetch_timewait_stamp(sk, dst);
 283
 284         icsk->icsk_ext_hdr_len = 0;
 285         if (np->opt)
 286                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 287                                           np->opt->opt_nflen);
 288
 289         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 290
 291         inet->inet_dport = usin->sin6_port;
 292
 293         tcp_set_state(sk, TCP_SYN_SENT);
 294         err = inet6_hash_connect(&tcp_death_row, sk);
 295         if (err)
 296                 goto late_failure;
 297
 298         if (!tp->write_seq && likely(!tp->repair))
 299                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 300                                                              np->daddr.s6_addr32,
 301                                                              inet->inet_sport,
 302                                                              inet->inet_dport);
 303
 304         err = tcp_connect(sk);
 305         if (err)
 306                 goto late_failure;
 307
 308         return 0;
 309
 310 late_failure:
 311         tcp_set_state(sk, TCP_CLOSE);
 312         __sk_dst_reset(sk);
 313 failure:
 314         inet->inet_dport = 0;
 315         sk->sk_route_caps = 0;
 316         return err;
 317 }
 318
 319 static void tcp_v6_mtu_reduced(struct sock *sk)
 320 {
 321         struct dst_entry *dst;
 322
 323         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 324                 return;
 325
 326         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 327         if (!dst)
 328                 return;
 329
 330         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 331                 tcp_sync_mss(sk, dst_mtu(dst));
 332                 tcp_simple_retransmit(sk);
 333         }
 334 }
 335
 336 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 337                 u8 type, u8 code, int offset, __be32 info)
 338 {
 339         const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
 340         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 341         struct ipv6_pinfo *np;
 342         struct sock *sk;
 343         int err;
 344         struct tcp_sock *tp;
 345         __u32 seq;
 346         struct net *net = dev_net(skb->dev);
 347
 348         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
 349                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 350
 351         if (sk == NULL) {
 352                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 353                                    ICMP6_MIB_INERRORS);
 354                 return;
 355         }
 356
 357         if (sk->sk_state == TCP_TIME_WAIT) {
 358                 inet_twsk_put(inet_twsk(sk));
 359                 return;
 360         }
 361
 362         bh_lock_sock(sk);
 363         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 364                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 365
 366         if (sk->sk_state == TCP_CLOSE)
 367                 goto out;
 368
 369         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 370                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 371                 goto out;
 372         }
 373
 374         tp = tcp_sk(sk);
 375         seq = ntohl(th->seq);
 376         if (sk->sk_state != TCP_LISTEN &&
 377             !between(seq, tp->snd_una, tp->snd_nxt)) {
 378                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 379                 goto out;
 380         }
 381
 382         np = inet6_sk(sk);
 383
 384         if (type == NDISC_REDIRECT) {
 385                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 386
 387                 if (dst)
 388                         dst->ops->redirect(dst, sk, skb);
 389         }
 390
 391         if (type == ICMPV6_PKT_TOOBIG) {
 392                 tp->mtu_info = ntohl(info);
 393                 if (!sock_owned_by_user(sk))
 394                         tcp_v6_mtu_reduced(sk);
 395                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 396                                            &tp->tsq_flags))
 397                         sock_hold(sk);
 398                 goto out;
 399         }
 400
 401         icmpv6_err_convert(type, code, &err);
 402
 403         /* Might be for an request_sock */
 404         switch (sk->sk_state) {
 405                 struct request_sock *req, **prev;
 406         case TCP_LISTEN:
 407                 if (sock_owned_by_user(sk))
 408                         goto out;
 409
 410                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 411                                            &hdr->saddr, inet6_iif(skb));
 412                 if (!req)
 413                         goto out;
 414
 415                 /* ICMPs are not backlogged, hence we cannot get
 416                  * an established socket here.
 417                  */
 418                 WARN_ON(req->sk != NULL);
 419
 420                 if (seq != tcp_rsk(req)->snt_isn) {
 421                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 422                         goto out;
 423                 }
 424
 425                 inet_csk_reqsk_queue_drop(sk, req, prev);
 426                 goto out;
 427
 428         case TCP_SYN_SENT:
 429         case TCP_SYN_RECV:  /* Cannot happen.
 430                                It can, it SYNs are crossed. --ANK */
 431                 if (!sock_owned_by_user(sk)) {
 432                         sk->sk_err = err;
 433                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 434
 435                         tcp_done(sk);
 436                 } else
 437                         sk->sk_err_soft = err;
 438                 goto out;
 439         }
 440
 441         if (!sock_owned_by_user(sk) && np->recverr) {
 442                 sk->sk_err = err;
 443                 sk->sk_error_report(sk);
 444         } else
 445                 sk->sk_err_soft = err;
 446
 447 out:
 448         bh_unlock_sock(sk);
 449         sock_put(sk);
 450 }
 451
 452
 453 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
 454                               struct flowi6 *fl6,
 455                               struct request_sock *req,
 456                               struct request_values *rvp,
 457                               u16 queue_mapping)
 458 {
 459         struct inet6_request_sock *treq = inet6_rsk(req);
 460         struct ipv6_pinfo *np = inet6_sk(sk);
 461         struct sk_buff * skb;
 462         int err = -ENOMEM;
 463
 464         /* First, grab a route. */
 465         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
 466                 goto done;
 467
 468         skb = tcp_make_synack(sk, dst, req, rvp, NULL);
 469
 470         if (skb) {
 471                 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
 472
 473                 fl6->daddr = treq->rmt_addr;
 474                 skb_set_queue_mapping(skb, queue_mapping);
 475                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 476                 err = net_xmit_eval(err);
 477         }
 478
 479 done:
 480         return err;
 481 }
 482
 483 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
 484                              struct request_values *rvp)
 485 {
 486         struct flowi6 fl6;
 487         int res;
 488
 489         res = tcp_v6_send_synack(sk, NULL, &fl6, req, rvp, 0);
 490         if (!res)
 491                 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
 492         return res;
 493 }
 494
 495 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 496 {
 497         kfree_skb(inet6_rsk(req)->pktopts);
 498 }
 499
 500 #ifdef CONFIG_TCP_MD5SIG
 501 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 502                                                    const struct in6_addr *addr)
 503 {
 504         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 505 }
 506
 507 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 508                                                 struct sock *addr_sk)
 509 {
 510         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 511 }
 512
 513 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 514                                                       struct request_sock *req)
 515 {
 516         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 517 }
 518
 519 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 520                                   int optlen)
 521 {
 522         struct tcp_md5sig cmd;
 523         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 524
 525         if (optlen < sizeof(cmd))
 526                 return -EINVAL;
 527
 528         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 529                 return -EFAULT;
 530
 531         if (sin6->sin6_family != AF_INET6)
 532                 return -EINVAL;
 533
 534         if (!cmd.tcpm_keylen) {
 535                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 536                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 537                                               AF_INET);
 538                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 539                                       AF_INET6);
 540         }
 541
 542         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 543                 return -EINVAL;
 544
 545         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 546                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 547                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 548
 549         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 550                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 551 }
 552
 553 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 554                                         const struct in6_addr *daddr,
 555                                         const struct in6_addr *saddr, int nbytes)
 556 {
 557         struct tcp6_pseudohdr *bp;
 558         struct scatterlist sg;
 559
 560         bp = &hp->md5_blk.ip6;
 561         /* 1. TCP pseudo-header (RFC2460) */
 562         bp->saddr = *saddr;
 563         bp->daddr = *daddr;
 564         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 565         bp->len = cpu_to_be32(nbytes);
 566
 567         sg_init_one(&sg, bp, sizeof(*bp));
 568         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 569 }
 570
 571 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 572                                const struct in6_addr *daddr, struct in6_addr *saddr,
 573                                const struct tcphdr *th)
 574 {
 575         struct tcp_md5sig_pool *hp;
 576         struct hash_desc *desc;
 577
 578         hp = tcp_get_md5sig_pool();
 579         if (!hp)
 580                 goto clear_hash_noput;
 581         desc = &hp->md5_desc;
 582
 583         if (crypto_hash_init(desc))
 584                 goto clear_hash;
 585         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 586                 goto clear_hash;
 587         if (tcp_md5_hash_header(hp, th))
 588                 goto clear_hash;
 589         if (tcp_md5_hash_key(hp, key))
 590                 goto clear_hash;
 591         if (crypto_hash_final(desc, md5_hash))
 592                 goto clear_hash;
 593
 594         tcp_put_md5sig_pool();
 595         return 0;
 596
 597 clear_hash:
 598         tcp_put_md5sig_pool();
 599 clear_hash_noput:
 600         memset(md5_hash, 0, 16);
 601         return 1;
 602 }
 603
 604 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 605                                const struct sock *sk,
 606                                const struct request_sock *req,
 607                                const struct sk_buff *skb)
 608 {
 609         const struct in6_addr *saddr, *daddr;
 610         struct tcp_md5sig_pool *hp;
 611         struct hash_desc *desc;
 612         const struct tcphdr *th = tcp_hdr(skb);
 613
 614         if (sk) {
 615                 saddr = &inet6_sk(sk)->saddr;
 616                 daddr = &inet6_sk(sk)->daddr;
 617         } else if (req) {
 618                 saddr = &inet6_rsk(req)->loc_addr;
 619                 daddr = &inet6_rsk(req)->rmt_addr;
 620         } else {
 621                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 622                 saddr = &ip6h->saddr;
 623                 daddr = &ip6h->daddr;
 624         }
 625
 626         hp = tcp_get_md5sig_pool();
 627         if (!hp)
 628                 goto clear_hash_noput;
 629         desc = &hp->md5_desc;
 630
 631         if (crypto_hash_init(desc))
 632                 goto clear_hash;
 633
 634         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 635                 goto clear_hash;
 636         if (tcp_md5_hash_header(hp, th))
 637                 goto clear_hash;
 638         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 639                 goto clear_hash;
 640         if (tcp_md5_hash_key(hp, key))
 641                 goto clear_hash;
 642         if (crypto_hash_final(desc, md5_hash))
 643                 goto clear_hash;
 644
 645         tcp_put_md5sig_pool();
 646         return 0;
 647
 648 clear_hash:
 649         tcp_put_md5sig_pool();
 650 clear_hash_noput:
 651         memset(md5_hash, 0, 16);
 652         return 1;
 653 }
 654
 655 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 656 {
 657         const __u8 *hash_location = NULL;
 658         struct tcp_md5sig_key *hash_expected;
 659         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 660         const struct tcphdr *th = tcp_hdr(skb);
 661         int genhash;
 662         u8 newhash[16];
 663
 664         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 665         hash_location = tcp_parse_md5sig_option(th);
 666
 667         /* We've parsed the options - do we have a hash? */
 668         if (!hash_expected && !hash_location)
 669                 return 0;
 670
 671         if (hash_expected && !hash_location) {
 672                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 673                 return 1;
 674         }
 675
 676         if (!hash_expected && hash_location) {
 677                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 678                 return 1;
 679         }
 680
 681         /* check the signature */
 682         genhash = tcp_v6_md5_hash_skb(newhash,
 683                                       hash_expected,
 684                                       NULL, NULL, skb);
 685
 686         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 687                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 688                                      genhash ? "failed" : "mismatch",
 689                                      &ip6h->saddr, ntohs(th->source),
 690                                      &ip6h->daddr, ntohs(th->dest));
 691                 return 1;
 692         }
 693         return 0;
 694 }
 695 #endif
 696
 697 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 698         .family         =       AF_INET6,
 699         .obj_size       =       sizeof(struct tcp6_request_sock),
 700         .rtx_syn_ack    =       tcp_v6_rtx_synack,
 701         .send_ack       =       tcp_v6_reqsk_send_ack,
 702         .destructor     =       tcp_v6_reqsk_destructor,
 703         .send_reset     =       tcp_v6_send_reset,
 704         .syn_ack_timeout =      tcp_syn_ack_timeout,
 705 };
 706
 707 #ifdef CONFIG_TCP_MD5SIG
 708 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 709         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 710         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 711 };
 712 #endif
 713
 714 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
 715                                  u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
 716 {
 717         const struct tcphdr *th = tcp_hdr(skb);
 718         struct tcphdr *t1;
 719         struct sk_buff *buff;
 720         struct flowi6 fl6;
 721         struct net *net = dev_net(skb_dst(skb)->dev);
 722         struct sock *ctl_sk = net->ipv6.tcp_sk;
 723         unsigned int tot_len = sizeof(struct tcphdr);
 724         struct dst_entry *dst;
 725         __be32 *topt;
 726
 727         if (ts)
 728                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 729 #ifdef CONFIG_TCP_MD5SIG
 730         if (key)
 731                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 732 #endif
 733
 734         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 735                          GFP_ATOMIC);
 736         if (buff == NULL)
 737                 return;
 738
 739         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 740
 741         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 742         skb_reset_transport_header(buff);
 743
 744         /* Swap the send and the receive. */
 745         memset(t1, 0, sizeof(*t1));
 746         t1->dest = th->source;
 747         t1->source = th->dest;
 748         t1->doff = tot_len / 4;
 749         t1->seq = htonl(seq);
 750         t1->ack_seq = htonl(ack);
 751         t1->ack = !rst || !th->ack;
 752         t1->rst = rst;
 753         t1->window = htons(win);
 754
 755         topt = (__be32 *)(t1 + 1);
 756
 757         if (ts) {
 758                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 759                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 760                 *topt++ = htonl(tcp_time_stamp);
 761                 *topt++ = htonl(ts);
 762         }
 763
 764 #ifdef CONFIG_TCP_MD5SIG
 765         if (key) {
 766                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 767                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 768                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 769                                     &ipv6_hdr(skb)->saddr,
 770                                     &ipv6_hdr(skb)->daddr, t1);
 771         }
 772 #endif
 773
 774         memset(&fl6, 0, sizeof(fl6));
 775         fl6.daddr = ipv6_hdr(skb)->saddr;
 776         fl6.saddr = ipv6_hdr(skb)->daddr;
 777
 778         buff->ip_summed = CHECKSUM_PARTIAL;
 779         buff->csum = 0;
 780
 781         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 782
 783         fl6.flowi6_proto = IPPROTO_TCP;
 784         if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
 785                 fl6.flowi6_oif = inet6_iif(skb);
 786         fl6.fl6_dport = t1->dest;
 787         fl6.fl6_sport = t1->source;
 788         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 789
 790         /* Pass a socket to ip6_dst_lookup either it is for RST
 791          * Underlying function will use this to retrieve the network
 792          * namespace
 793          */
 794         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
 795         if (!IS_ERR(dst)) {
 796                 skb_dst_set(buff, dst);
 797                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 798                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 799                 if (rst)
 800                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 801                 return;
 802         }
 803
 804         kfree_skb(buff);
 805 }
 806
 807 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 808 {
 809         const struct tcphdr *th = tcp_hdr(skb);
 810         u32 seq = 0, ack_seq = 0;
 811         struct tcp_md5sig_key *key = NULL;
 812 #ifdef CONFIG_TCP_MD5SIG
 813         const __u8 *hash_location = NULL;
 814         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 815         unsigned char newhash[16];
 816         int genhash;
 817         struct sock *sk1 = NULL;
 818 #endif
 819
 820         if (th->rst)
 821                 return;
 822
 823         if (!ipv6_unicast_destination(skb))
 824                 return;
 825
 826 #ifdef CONFIG_TCP_MD5SIG
 827         hash_location = tcp_parse_md5sig_option(th);
 828         if (!sk && hash_location) {
 829                 /*
 830                  * active side is lost. Try to find listening socket through
 831                  * source port, and then find md5 key through listening socket.
 832                  * we are not loose security here:
 833                  * Incoming packet is checked with md5 hash with finding key,
 834                  * no RST generated if md5 hash doesn't match.
 835                  */
 836                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 837                                            &tcp_hashinfo, &ipv6h->daddr,
 838                                            ntohs(th->source), inet6_iif(skb));
 839                 if (!sk1)
 840                         return;
 841
 842                 rcu_read_lock();
 843                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 844                 if (!key)
 845                         goto release_sk1;
 846
 847                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
 848                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 849                         goto release_sk1;
 850         } else {
 851                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 852         }
 853 #endif
 854
 855         if (th->ack)
 856                 seq = ntohl(th->ack_seq);
 857         else
 858                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 859                           (th->doff << 2);
 860
 861         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
 862
 863 #ifdef CONFIG_TCP_MD5SIG
 864 release_sk1:
 865         if (sk1) {
 866                 rcu_read_unlock();
 867                 sock_put(sk1);
 868         }
 869 #endif
 870 }
 871
 872 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
 873                             struct tcp_md5sig_key *key, u8 tclass)
 874 {
 875         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
 876 }
 877
 878 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 879 {
 880         struct inet_timewait_sock *tw = inet_twsk(sk);
 881         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 882
 883         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 884                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 885                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
 886                         tw->tw_tclass);
 887
 888         inet_twsk_put(tw);
 889 }
 890
 891 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 892                                   struct request_sock *req)
 893 {
 894         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
 895                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
 896 }
 897
 898
 899 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
 900 {
 901         struct request_sock *req, **prev;
 902         const struct tcphdr *th = tcp_hdr(skb);
 903         struct sock *nsk;
 904
 905         /* Find possible connection requests. */
 906         req = inet6_csk_search_req(sk, &prev, th->source,
 907                                    &ipv6_hdr(skb)->saddr,
 908                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
 909         if (req)
 910                 return tcp_check_req(sk, skb, req, prev, false);
 911
 912         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 913                         &ipv6_hdr(skb)->saddr, th->source,
 914                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
 915
 916         if (nsk) {
 917                 if (nsk->sk_state != TCP_TIME_WAIT) {
 918                         bh_lock_sock(nsk);
 919                         return nsk;
 920                 }
 921                 inet_twsk_put(inet_twsk(nsk));
 922                 return NULL;
 923         }
 924
 925 #ifdef CONFIG_SYN_COOKIES
 926         if (!th->syn)
 927                 sk = cookie_v6_check(sk, skb);
 928 #endif
 929         return sk;
 930 }
 931
 932 /* FIXME: this is substantially similar to the ipv4 code.
 933  * Can some kind of merge be done? -- erics
 934  */
 935 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 936 {
 937         struct tcp_extend_values tmp_ext;
 938         struct tcp_options_received tmp_opt;
 939         const u8 *hash_location;
 940         struct request_sock *req;
 941         struct inet6_request_sock *treq;
 942         struct ipv6_pinfo *np = inet6_sk(sk);
 943         struct tcp_sock *tp = tcp_sk(sk);
 944         __u32 isn = TCP_SKB_CB(skb)->when;
 945         struct dst_entry *dst = NULL;
 946         struct flowi6 fl6;
 947         bool want_cookie = false;
 948
 949         if (skb->protocol == htons(ETH_P_IP))
 950                 return tcp_v4_conn_request(sk, skb);
 951
 952         if (!ipv6_unicast_destination(skb))
 953                 goto drop;
 954
 955         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
 956                 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
 957                 if (!want_cookie)
 958                         goto drop;
 959         }
 960
 961         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
 962                 goto drop;
 963
 964         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
 965         if (req == NULL)
 966                 goto drop;
 967
 968 #ifdef CONFIG_TCP_MD5SIG
 969         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
 970 #endif
 971
 972         tcp_clear_options(&tmp_opt);
 973         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 974         tmp_opt.user_mss = tp->rx_opt.user_mss;
 975         tcp_parse_options(skb, &tmp_opt, &hash_location, 0, NULL);
 976
 977         if (tmp_opt.cookie_plus > 0 &&
 978             tmp_opt.saw_tstamp &&
 979             !tp->rx_opt.cookie_out_never &&
 980             (sysctl_tcp_cookie_size > 0 ||
 981              (tp->cookie_values != NULL &&
 982               tp->cookie_values->cookie_desired > 0))) {
 983                 u8 *c;
 984                 u32 *d;
 985                 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
 986                 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
 987
 988                 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
 989                         goto drop_and_free;
 990
 991                 /* Secret recipe starts with IP addresses */
 992                 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
 993                 *mess++ ^= *d++;
 994                 *mess++ ^= *d++;
 995                 *mess++ ^= *d++;
 996                 *mess++ ^= *d++;
 997                 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
 998                 *mess++ ^= *d++;
 999                 *mess++ ^= *d++;
1000                 *mess++ ^= *d++;
1001                 *mess++ ^= *d++;
1002
1003                 /* plus variable length Initiator Cookie */
1004                 c = (u8 *)mess;
1005                 while (l-- > 0)
1006                         *c++ ^= *hash_location++;
1007
1008                 want_cookie = false;    /* not our kind of cookie */
1009                 tmp_ext.cookie_out_never = 0; /* false */
1010                 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1011         } else if (!tp->rx_opt.cookie_in_always) {
1012                 /* redundant indications, but ensure initialization. */
1013                 tmp_ext.cookie_out_never = 1; /* true */
1014                 tmp_ext.cookie_plus = 0;
1015         } else {
1016                 goto drop_and_free;
1017         }
1018         tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1019
1020         if (want_cookie && !tmp_opt.saw_tstamp)
1021                 tcp_clear_options(&tmp_opt);
1022
1023         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1024         tcp_openreq_init(req, &tmp_opt, skb);
1025
1026         treq = inet6_rsk(req);
1027         treq->rmt_addr = ipv6_hdr(skb)->saddr;
1028         treq->loc_addr = ipv6_hdr(skb)->daddr;
1029         if (!want_cookie || tmp_opt.tstamp_ok)
1030                 TCP_ECN_create_request(req, skb);
1031
1032         treq->iif = sk->sk_bound_dev_if;
1033
1034         /* So that link locals have meaning */
1035         if (!sk->sk_bound_dev_if &&
1036             ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1037                 treq->iif = inet6_iif(skb);
1038
1039         if (!isn) {
1040                 if (ipv6_opt_accepted(sk, skb) ||
1041                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1042                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1043                         atomic_inc(&skb->users);
1044                         treq->pktopts = skb;
1045                 }
1046
1047                 if (want_cookie) {
1048                         isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1049                         req->cookie_ts = tmp_opt.tstamp_ok;
1050                         goto have_isn;
1051                 }
1052
1053                 /* VJ's idea. We save last timestamp seen
1054                  * from the destination in peer table, when entering
1055                  * state TIME-WAIT, and check against it before
1056                  * accepting new connection request.
1057                  *
1058                  * If "isn" is not zero, this request hit alive
1059                  * timewait bucket, so that all the necessary checks
1060                  * are made in the function processing timewait state.
1061                  */
1062                 if (tmp_opt.saw_tstamp &&
1063                     tcp_death_row.sysctl_tw_recycle &&
1064                     (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1065                         if (!tcp_peer_is_proven(req, dst, true)) {
1066                                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1067                                 goto drop_and_release;
1068                         }
1069                 }
1070                 /* Kill the following clause, if you dislike this way. */
1071                 else if (!sysctl_tcp_syncookies &&
1072                          (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1073                           (sysctl_max_syn_backlog >> 2)) &&
1074                          !tcp_peer_is_proven(req, dst, false)) {
1075                         /* Without syncookies last quarter of
1076                          * backlog is filled with destinations,
1077                          * proven to be alive.
1078                          * It means that we continue to communicate
1079                          * to destinations, already remembered
1080                          * to the moment of synflood.
1081                          */
1082                         LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1083                                        &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1084                         goto drop_and_release;
1085                 }
1086
1087                 isn = tcp_v6_init_sequence(skb);
1088         }
1089 have_isn:
1090         tcp_rsk(req)->snt_isn = isn;
1091
1092         if (security_inet_conn_request(sk, skb, req))
1093                 goto drop_and_release;
1094
1095         if (tcp_v6_send_synack(sk, dst, &fl6, req,
1096                                (struct request_values *)&tmp_ext,
1097                                skb_get_queue_mapping(skb)) ||
1098             want_cookie)
1099                 goto drop_and_free;
1100
1101         tcp_rsk(req)->snt_synack = tcp_time_stamp;
1102         tcp_rsk(req)->listener = NULL;
1103         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1104         return 0;
1105
1106 drop_and_release:
1107         dst_release(dst);
1108 drop_and_free:
1109         reqsk_free(req);
1110 drop:
1111         return 0; /* don't send reset */
1112 }
1113
1114 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1115                                           struct request_sock *req,
1116                                           struct dst_entry *dst)
1117 {
1118         struct inet6_request_sock *treq;
1119         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1120         struct tcp6_sock *newtcp6sk;
1121         struct inet_sock *newinet;
1122         struct tcp_sock *newtp;
1123         struct sock *newsk;
1124 #ifdef CONFIG_TCP_MD5SIG
1125         struct tcp_md5sig_key *key;
1126 #endif
1127         struct flowi6 fl6;
1128
1129         if (skb->protocol == htons(ETH_P_IP)) {
1130                 /*
1131                  *      v6 mapped
1132                  */
1133
1134                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1135
1136                 if (newsk == NULL)
1137                         return NULL;
1138
1139                 newtcp6sk = (struct tcp6_sock *)newsk;
1140                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1141
1142                 newinet = inet_sk(newsk);
1143                 newnp = inet6_sk(newsk);
1144                 newtp = tcp_sk(newsk);
1145
1146                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1147
1148                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1149
1150                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1151
1152                 newnp->rcv_saddr = newnp->saddr;
1153
1154                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1155                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1156 #ifdef CONFIG_TCP_MD5SIG
1157                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1158 #endif
1159
1160                 newnp->ipv6_ac_list = NULL;
1161                 newnp->ipv6_fl_list = NULL;
1162                 newnp->pktoptions  = NULL;
1163                 newnp->opt         = NULL;
1164                 newnp->mcast_oif   = inet6_iif(skb);
1165                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1166                 newnp->rcv_tclass  = ipv6_tclass(ipv6_hdr(skb));
1167
1168                 /*
1169                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1170                  * here, tcp_create_openreq_child now does this for us, see the comment in
1171                  * that function for the gory details. -acme
1172                  */
1173
1174                 /* It is tricky place. Until this moment IPv4 tcp
1175                    worked with IPv6 icsk.icsk_af_ops.
1176                    Sync it now.
1177                  */
1178                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1179
1180                 return newsk;
1181         }
1182
1183         treq = inet6_rsk(req);
1184
1185         if (sk_acceptq_is_full(sk))
1186                 goto out_overflow;
1187
1188         if (!dst) {
1189                 dst = inet6_csk_route_req(sk, &fl6, req);
1190                 if (!dst)
1191                         goto out;
1192         }
1193
1194         newsk = tcp_create_openreq_child(sk, req, skb);
1195         if (newsk == NULL)
1196                 goto out_nonewsk;
1197
1198         /*
1199          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1200          * count here, tcp_create_openreq_child now does this for us, see the
1201          * comment in that function for the gory details. -acme
1202          */
1203
1204         newsk->sk_gso_type = SKB_GSO_TCPV6;
1205         __ip6_dst_store(newsk, dst, NULL, NULL);
1206         inet6_sk_rx_dst_set(newsk, skb);
1207
1208         newtcp6sk = (struct tcp6_sock *)newsk;
1209         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1210
1211         newtp = tcp_sk(newsk);
1212         newinet = inet_sk(newsk);
1213         newnp = inet6_sk(newsk);
1214
1215         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1216
1217         newnp->daddr = treq->rmt_addr;
1218         newnp->saddr = treq->loc_addr;
1219         newnp->rcv_saddr = treq->loc_addr;
1220         newsk->sk_bound_dev_if = treq->iif;
1221
1222         /* Now IPv6 options...
1223
1224            First: no IPv4 options.
1225          */
1226         newinet->inet_opt = NULL;
1227         newnp->ipv6_ac_list = NULL;
1228         newnp->ipv6_fl_list = NULL;
1229
1230         /* Clone RX bits */
1231         newnp->rxopt.all = np->rxopt.all;
1232
1233         /* Clone pktoptions received with SYN */
1234         newnp->pktoptions = NULL;
1235         if (treq->pktopts != NULL) {
1236                 newnp->pktoptions = skb_clone(treq->pktopts,
1237                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1238                 consume_skb(treq->pktopts);
1239                 treq->pktopts = NULL;
1240                 if (newnp->pktoptions)
1241                         skb_set_owner_r(newnp->pktoptions, newsk);
1242         }
1243         newnp->opt        = NULL;
1244         newnp->mcast_oif  = inet6_iif(skb);
1245         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1246         newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1247
1248         /* Clone native IPv6 options from listening socket (if any)
1249
1250            Yes, keeping reference count would be much more clever,
1251            but we make one more one thing there: reattach optmem
1252            to newsk.
1253          */
1254         if (np->opt)
1255                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1256
1257         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1258         if (newnp->opt)
1259                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1260                                                      newnp->opt->opt_flen);
1261
1262         tcp_mtup_init(newsk);
1263         tcp_sync_mss(newsk, dst_mtu(dst));
1264         newtp->advmss = dst_metric_advmss(dst);
1265         if (tcp_sk(sk)->rx_opt.user_mss &&
1266             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1267                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1268
1269         tcp_initialize_rcv_mss(newsk);
1270         tcp_synack_rtt_meas(newsk, req);
1271         newtp->total_retrans = req->num_retrans;
1272
1273         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1274         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1275
1276 #ifdef CONFIG_TCP_MD5SIG
1277         /* Copy over the MD5 key from the original socket */
1278         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1279                 /* We're using one, so create a matching key
1280                  * on the newsk structure. If we fail to get
1281                  * memory, then we end up not copying the key
1282                  * across. Shucks.
1283                  */
1284                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1285                                AF_INET6, key->key, key->keylen,
1286                                sk_gfp_atomic(sk, GFP_ATOMIC));
1287         }
1288 #endif
1289
1290         if (__inet_inherit_port(sk, newsk) < 0) {
1291                 sock_put(newsk);
1292                 goto out;
1293         }
1294         __inet6_hash(newsk, NULL);
1295
1296         return newsk;
1297
1298 out_overflow:
1299         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1300 out_nonewsk:
1301         dst_release(dst);
1302 out:
1303         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1304         return NULL;
1305 }
1306
1307 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1308 {
1309         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1310                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1311                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1312                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1313                         return 0;
1314                 }
1315         }
1316
1317         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1318                                               &ipv6_hdr(skb)->saddr,
1319                                               &ipv6_hdr(skb)->daddr, 0));
1320
1321         if (skb->len <= 76) {
1322                 return __skb_checksum_complete(skb);
1323         }
1324         return 0;
1325 }
1326
1327 /* The socket must have it's spinlock held when we get
1328  * here.
1329  *
1330  * We have a potential double-lock case here, so even when
1331  * doing backlog processing we use the BH locking scheme.
1332  * This is because we cannot sleep with the original spinlock
1333  * held.
1334  */
1335 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1336 {
1337         struct ipv6_pinfo *np = inet6_sk(sk);
1338         struct tcp_sock *tp;
1339         struct sk_buff *opt_skb = NULL;
1340
1341         /* Imagine: socket is IPv6. IPv4 packet arrives,
1342            goes to IPv4 receive handler and backlogged.
1343            From backlog it always goes here. Kerboom...
1344            Fortunately, tcp_rcv_established and rcv_established
1345            handle them correctly, but it is not case with
1346            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1347          */
1348
1349         if (skb->protocol == htons(ETH_P_IP))
1350                 return tcp_v4_do_rcv(sk, skb);
1351
1352 #ifdef CONFIG_TCP_MD5SIG
1353         if (tcp_v6_inbound_md5_hash (sk, skb))
1354                 goto discard;
1355 #endif
1356
1357         if (sk_filter(sk, skb))
1358                 goto discard;
1359
1360         /*
1361          *      socket locking is here for SMP purposes as backlog rcv
1362          *      is currently called with bh processing disabled.
1363          */
1364
1365         /* Do Stevens' IPV6_PKTOPTIONS.
1366
1367            Yes, guys, it is the only place in our code, where we
1368            may make it not affecting IPv4.
1369            The rest of code is protocol independent,
1370            and I do not like idea to uglify IPv4.
1371
1372            Actually, all the idea behind IPV6_PKTOPTIONS
1373            looks not very well thought. For now we latch
1374            options, received in the last packet, enqueued
1375            by tcp. Feel free to propose better solution.
1376                                                --ANK (980728)
1377          */
1378         if (np->rxopt.all)
1379                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1380
1381         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1382                 struct dst_entry *dst = sk->sk_rx_dst;
1383
1384                 sock_rps_save_rxhash(sk, skb);
1385                 if (dst) {
1386                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1387                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1388                                 dst_release(dst);
1389                                 sk->sk_rx_dst = NULL;
1390                         }
1391                 }
1392
1393                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1394                         goto reset;
1395                 if (opt_skb)
1396                         goto ipv6_pktoptions;
1397                 return 0;
1398         }
1399
1400         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1401                 goto csum_err;
1402
1403         if (sk->sk_state == TCP_LISTEN) {
1404                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1405                 if (!nsk)
1406                         goto discard;
1407
1408                 /*
1409                  * Queue it on the new socket if the new socket is active,
1410                  * otherwise we just shortcircuit this and continue with
1411                  * the new socket..
1412                  */
1413                 if(nsk != sk) {
1414                         sock_rps_save_rxhash(nsk, skb);
1415                         if (tcp_child_process(sk, nsk, skb))
1416                                 goto reset;
1417                         if (opt_skb)
1418                                 __kfree_skb(opt_skb);
1419                         return 0;
1420                 }
1421         } else
1422                 sock_rps_save_rxhash(sk, skb);
1423
1424         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1425                 goto reset;
1426         if (opt_skb)
1427                 goto ipv6_pktoptions;
1428         return 0;
1429
1430 reset:
1431         tcp_v6_send_reset(sk, skb);
1432 discard:
1433         if (opt_skb)
1434                 __kfree_skb(opt_skb);
1435         kfree_skb(skb);
1436         return 0;
1437 csum_err:
1438         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1439         goto discard;
1440
1441
1442 ipv6_pktoptions:
1443         /* Do you ask, what is it?
1444
1445            1. skb was enqueued by tcp.
1446            2. skb is added to tail of read queue, rather than out of order.
1447            3. socket is not in passive state.
1448            4. Finally, it really contains options, which user wants to receive.
1449          */
1450         tp = tcp_sk(sk);
1451         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1452             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1453                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1454                         np->mcast_oif = inet6_iif(opt_skb);
1455                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1456                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1457                 if (np->rxopt.bits.rxtclass)
1458                         np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1459                 if (ipv6_opt_accepted(sk, opt_skb)) {
1460                         skb_set_owner_r(opt_skb, sk);
1461                         opt_skb = xchg(&np->pktoptions, opt_skb);
1462                 } else {
1463                         __kfree_skb(opt_skb);
1464                         opt_skb = xchg(&np->pktoptions, NULL);
1465                 }
1466         }
1467
1468         kfree_skb(opt_skb);
1469         return 0;
1470 }
1471
1472 static int tcp_v6_rcv(struct sk_buff *skb)
1473 {
1474         const struct tcphdr *th;
1475         const struct ipv6hdr *hdr;
1476         struct sock *sk;
1477         int ret;
1478         struct net *net = dev_net(skb->dev);
1479
1480         if (skb->pkt_type != PACKET_HOST)
1481                 goto discard_it;
1482
1483         /*
1484          *      Count it even if it's bad.
1485          */
1486         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1487
1488         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1489                 goto discard_it;
1490
1491         th = tcp_hdr(skb);
1492
1493         if (th->doff < sizeof(struct tcphdr)/4)
1494                 goto bad_packet;
1495         if (!pskb_may_pull(skb, th->doff*4))
1496                 goto discard_it;
1497
1498         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1499                 goto bad_packet;
1500
1501         th = tcp_hdr(skb);
1502         hdr = ipv6_hdr(skb);
1503         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1504         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1505                                     skb->len - th->doff*4);
1506         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1507         TCP_SKB_CB(skb)->when = 0;
1508         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1509         TCP_SKB_CB(skb)->sacked = 0;
1510
1511         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1512         if (!sk)
1513                 goto no_tcp_socket;
1514
1515 process:
1516         if (sk->sk_state == TCP_TIME_WAIT)
1517                 goto do_time_wait;
1518
1519         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1520                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1521                 goto discard_and_relse;
1522         }
1523
1524         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1525                 goto discard_and_relse;
1526
1527         if (sk_filter(sk, skb))
1528                 goto discard_and_relse;
1529
1530         skb->dev = NULL;
1531
1532         bh_lock_sock_nested(sk);
1533         ret = 0;
1534         if (!sock_owned_by_user(sk)) {
1535 #ifdef CONFIG_NET_DMA
1536                 struct tcp_sock *tp = tcp_sk(sk);
1537                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1538                         tp->ucopy.dma_chan = net_dma_find_channel();
1539                 if (tp->ucopy.dma_chan)
1540                         ret = tcp_v6_do_rcv(sk, skb);
1541                 else
1542 #endif
1543                 {
1544                         if (!tcp_prequeue(sk, skb))
1545                                 ret = tcp_v6_do_rcv(sk, skb);
1546                 }
1547         } else if (unlikely(sk_add_backlog(sk, skb,
1548                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1549                 bh_unlock_sock(sk);
1550                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1551                 goto discard_and_relse;
1552         }
1553         bh_unlock_sock(sk);
1554
1555         sock_put(sk);
1556         return ret ? -1 : 0;
1557
1558 no_tcp_socket:
1559         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1560                 goto discard_it;
1561
1562         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1563 bad_packet:
1564                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1565         } else {
1566                 tcp_v6_send_reset(NULL, skb);
1567         }
1568
1569 discard_it:
1570
1571         /*
1572          *      Discard frame
1573          */
1574
1575         kfree_skb(skb);
1576         return 0;
1577
1578 discard_and_relse:
1579         sock_put(sk);
1580         goto discard_it;
1581
1582 do_time_wait:
1583         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1584                 inet_twsk_put(inet_twsk(sk));
1585                 goto discard_it;
1586         }
1587
1588         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1589                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1590                 inet_twsk_put(inet_twsk(sk));
1591                 goto discard_it;
1592         }
1593
1594         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1595         case TCP_TW_SYN:
1596         {
1597                 struct sock *sk2;
1598
1599                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1600                                             &ipv6_hdr(skb)->daddr,
1601                                             ntohs(th->dest), inet6_iif(skb));
1602                 if (sk2 != NULL) {
1603                         struct inet_timewait_sock *tw = inet_twsk(sk);
1604                         inet_twsk_deschedule(tw, &tcp_death_row);
1605                         inet_twsk_put(tw);
1606                         sk = sk2;
1607                         goto process;
1608                 }
1609                 /* Fall through to ACK */
1610         }
1611         case TCP_TW_ACK:
1612                 tcp_v6_timewait_ack(sk, skb);
1613                 break;
1614         case TCP_TW_RST:
1615                 goto no_tcp_socket;
1616         case TCP_TW_SUCCESS:;
1617         }
1618         goto discard_it;
1619 }
1620
1621 static void tcp_v6_early_demux(struct sk_buff *skb)
1622 {
1623         const struct ipv6hdr *hdr;
1624         const struct tcphdr *th;
1625         struct sock *sk;
1626
1627         if (skb->pkt_type != PACKET_HOST)
1628                 return;
1629
1630         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1631                 return;
1632
1633         hdr = ipv6_hdr(skb);
1634         th = tcp_hdr(skb);
1635
1636         if (th->doff < sizeof(struct tcphdr) / 4)
1637                 return;
1638
1639         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1640                                         &hdr->saddr, th->source,
1641                                         &hdr->daddr, ntohs(th->dest),
1642                                         inet6_iif(skb));
1643         if (sk) {
1644                 skb->sk = sk;
1645                 skb->destructor = sock_edemux;
1646                 if (sk->sk_state != TCP_TIME_WAIT) {
1647                         struct dst_entry *dst = sk->sk_rx_dst;
1648
1649                         if (dst)
1650                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1651                         if (dst &&
1652                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1653                                 skb_dst_set_noref(skb, dst);
1654                 }
1655         }
1656 }
1657
1658 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1659         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1660         .twsk_unique    = tcp_twsk_unique,
1661         .twsk_destructor= tcp_twsk_destructor,
1662 };
1663
1664 static const struct inet_connection_sock_af_ops ipv6_specific = {
1665         .queue_xmit        = inet6_csk_xmit,
1666         .send_check        = tcp_v6_send_check,
1667         .rebuild_header    = inet6_sk_rebuild_header,
1668         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1669         .conn_request      = tcp_v6_conn_request,
1670         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1671         .net_header_len    = sizeof(struct ipv6hdr),
1672         .net_frag_header_len = sizeof(struct frag_hdr),
1673         .setsockopt        = ipv6_setsockopt,
1674         .getsockopt        = ipv6_getsockopt,
1675         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1676         .sockaddr_len      = sizeof(struct sockaddr_in6),
1677         .bind_conflict     = inet6_csk_bind_conflict,
1678 #ifdef CONFIG_COMPAT
1679         .compat_setsockopt = compat_ipv6_setsockopt,
1680         .compat_getsockopt = compat_ipv6_getsockopt,
1681 #endif
1682 };
1683
1684 #ifdef CONFIG_TCP_MD5SIG
1685 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1686         .md5_lookup     =       tcp_v6_md5_lookup,
1687         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1688         .md5_parse      =       tcp_v6_parse_md5_keys,
1689 };
1690 #endif
1691
1692 /*
1693  *      TCP over IPv4 via INET6 API
1694  */
1695
1696 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1697         .queue_xmit        = ip_queue_xmit,
1698         .send_check        = tcp_v4_send_check,
1699         .rebuild_header    = inet_sk_rebuild_header,
1700         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1701         .conn_request      = tcp_v6_conn_request,
1702         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1703         .net_header_len    = sizeof(struct iphdr),
1704         .setsockopt        = ipv6_setsockopt,
1705         .getsockopt        = ipv6_getsockopt,
1706         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1707         .sockaddr_len      = sizeof(struct sockaddr_in6),
1708         .bind_conflict     = inet6_csk_bind_conflict,
1709 #ifdef CONFIG_COMPAT
1710         .compat_setsockopt = compat_ipv6_setsockopt,
1711         .compat_getsockopt = compat_ipv6_getsockopt,
1712 #endif
1713 };
1714
1715 #ifdef CONFIG_TCP_MD5SIG
1716 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1717         .md5_lookup     =       tcp_v4_md5_lookup,
1718         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1719         .md5_parse      =       tcp_v6_parse_md5_keys,
1720 };
1721 #endif
1722
1723 /* NOTE: A lot of things set to zero explicitly by call to
1724  *       sk_alloc() so need not be done here.
1725  */
1726 static int tcp_v6_init_sock(struct sock *sk)
1727 {
1728         struct inet_connection_sock *icsk = inet_csk(sk);
1729
1730         tcp_init_sock(sk);
1731
1732         icsk->icsk_af_ops = &ipv6_specific;
1733
1734 #ifdef CONFIG_TCP_MD5SIG
1735         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1736 #endif
1737
1738         return 0;
1739 }
1740
1741 static void tcp_v6_destroy_sock(struct sock *sk)
1742 {
1743         tcp_v4_destroy_sock(sk);
1744         inet6_destroy_sock(sk);
1745 }
1746
1747 #ifdef CONFIG_PROC_FS
1748 /* Proc filesystem TCPv6 sock list dumping. */
1749 static void get_openreq6(struct seq_file *seq,
1750                          const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1751 {
1752         int ttd = req->expires - jiffies;
1753         const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1754         const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1755
1756         if (ttd < 0)
1757                 ttd = 0;
1758
1759         seq_printf(seq,
1760                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1761                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1762                    i,
1763                    src->s6_addr32[0], src->s6_addr32[1],
1764                    src->s6_addr32[2], src->s6_addr32[3],
1765                    ntohs(inet_rsk(req)->loc_port),
1766                    dest->s6_addr32[0], dest->s6_addr32[1],
1767                    dest->s6_addr32[2], dest->s6_addr32[3],
1768                    ntohs(inet_rsk(req)->rmt_port),
1769                    TCP_SYN_RECV,
1770                    0,0, /* could print option size, but that is af dependent. */
1771                    1,   /* timers active (only the expire timer) */
1772                    jiffies_to_clock_t(ttd),
1773                    req->num_timeout,
1774                    from_kuid_munged(seq_user_ns(seq), uid),
1775                    0,  /* non standard timer */
1776                    0, /* open_requests have no inode */
1777                    0, req);
1778 }
1779
1780 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1781 {
1782         const struct in6_addr *dest, *src;
1783         __u16 destp, srcp;
1784         int timer_active;
1785         unsigned long timer_expires;
1786         const struct inet_sock *inet = inet_sk(sp);
1787         const struct tcp_sock *tp = tcp_sk(sp);
1788         const struct inet_connection_sock *icsk = inet_csk(sp);
1789         const struct ipv6_pinfo *np = inet6_sk(sp);
1790
1791         dest  = &np->daddr;
1792         src   = &np->rcv_saddr;
1793         destp = ntohs(inet->inet_dport);
1794         srcp  = ntohs(inet->inet_sport);
1795
1796         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1797                 timer_active    = 1;
1798                 timer_expires   = icsk->icsk_timeout;
1799         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1800                 timer_active    = 4;
1801                 timer_expires   = icsk->icsk_timeout;
1802         } else if (timer_pending(&sp->sk_timer)) {
1803                 timer_active    = 2;
1804                 timer_expires   = sp->sk_timer.expires;
1805         } else {
1806                 timer_active    = 0;
1807                 timer_expires = jiffies;
1808         }
1809
1810         seq_printf(seq,
1811                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1812                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1813                    i,
1814                    src->s6_addr32[0], src->s6_addr32[1],
1815                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1816                    dest->s6_addr32[0], dest->s6_addr32[1],
1817                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1818                    sp->sk_state,
1819                    tp->write_seq-tp->snd_una,
1820                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1821                    timer_active,
1822                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1823                    icsk->icsk_retransmits,
1824                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1825                    icsk->icsk_probes_out,
1826                    sock_i_ino(sp),
1827                    atomic_read(&sp->sk_refcnt), sp,
1828                    jiffies_to_clock_t(icsk->icsk_rto),
1829                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1830                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1831                    tp->snd_cwnd,
1832                    tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1833                    );
1834 }
1835
1836 static void get_timewait6_sock(struct seq_file *seq,
1837                                struct inet_timewait_sock *tw, int i)
1838 {
1839         const struct in6_addr *dest, *src;
1840         __u16 destp, srcp;
1841         const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1842         long delta = tw->tw_ttd - jiffies;
1843
1844         dest = &tw6->tw_v6_daddr;
1845         src  = &tw6->tw_v6_rcv_saddr;
1846         destp = ntohs(tw->tw_dport);
1847         srcp  = ntohs(tw->tw_sport);
1848
1849         seq_printf(seq,
1850                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1851                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1852                    i,
1853                    src->s6_addr32[0], src->s6_addr32[1],
1854                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1855                    dest->s6_addr32[0], dest->s6_addr32[1],
1856                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1857                    tw->tw_substate, 0, 0,
1858                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1859                    atomic_read(&tw->tw_refcnt), tw);
1860 }
1861
1862 static int tcp6_seq_show(struct seq_file *seq, void *v)
1863 {
1864         struct tcp_iter_state *st;
1865
1866         if (v == SEQ_START_TOKEN) {
1867                 seq_puts(seq,
1868                          "  sl  "
1869                          "local_address                         "
1870                          "remote_address                        "
1871                          "st tx_queue rx_queue tr tm->when retrnsmt"
1872                          "   uid  timeout inode\n");
1873                 goto out;
1874         }
1875         st = seq->private;
1876
1877         switch (st->state) {
1878         case TCP_SEQ_STATE_LISTENING:
1879         case TCP_SEQ_STATE_ESTABLISHED:
1880                 get_tcp6_sock(seq, v, st->num);
1881                 break;
1882         case TCP_SEQ_STATE_OPENREQ:
1883                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1884                 break;
1885         case TCP_SEQ_STATE_TIME_WAIT:
1886                 get_timewait6_sock(seq, v, st->num);
1887                 break;
1888         }
1889 out:
1890         return 0;
1891 }
1892
1893 static const struct file_operations tcp6_afinfo_seq_fops = {
1894         .owner   = THIS_MODULE,
1895         .open    = tcp_seq_open,
1896         .read    = seq_read,
1897         .llseek  = seq_lseek,
1898         .release = seq_release_net
1899 };
1900
1901 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1902         .name           = "tcp6",
1903         .family         = AF_INET6,
1904         .seq_fops       = &tcp6_afinfo_seq_fops,
1905         .seq_ops        = {
1906                 .show           = tcp6_seq_show,
1907         },
1908 };
1909
1910 int __net_init tcp6_proc_init(struct net *net)
1911 {
1912         return tcp_proc_register(net, &tcp6_seq_afinfo);
1913 }
1914
1915 void tcp6_proc_exit(struct net *net)
1916 {
1917         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1918 }
1919 #endif
1920
1921 struct proto tcpv6_prot = {
1922         .name                   = "TCPv6",
1923         .owner                  = THIS_MODULE,
1924         .close                  = tcp_close,
1925         .connect                = tcp_v6_connect,
1926         .disconnect             = tcp_disconnect,
1927         .accept                 = inet_csk_accept,
1928         .ioctl                  = tcp_ioctl,
1929         .init                   = tcp_v6_init_sock,
1930         .destroy                = tcp_v6_destroy_sock,
1931         .shutdown               = tcp_shutdown,
1932         .setsockopt             = tcp_setsockopt,
1933         .getsockopt             = tcp_getsockopt,
1934         .recvmsg                = tcp_recvmsg,
1935         .sendmsg                = tcp_sendmsg,
1936         .sendpage               = tcp_sendpage,
1937         .backlog_rcv            = tcp_v6_do_rcv,
1938         .release_cb             = tcp_release_cb,
1939         .mtu_reduced            = tcp_v6_mtu_reduced,
1940         .hash                   = tcp_v6_hash,
1941         .unhash                 = inet_unhash,
1942         .get_port               = inet_csk_get_port,
1943         .enter_memory_pressure  = tcp_enter_memory_pressure,
1944         .sockets_allocated      = &tcp_sockets_allocated,
1945         .memory_allocated       = &tcp_memory_allocated,
1946         .memory_pressure        = &tcp_memory_pressure,
1947         .orphan_count           = &tcp_orphan_count,
1948         .sysctl_wmem            = sysctl_tcp_wmem,
1949         .sysctl_rmem            = sysctl_tcp_rmem,
1950         .max_header             = MAX_TCP_HEADER,
1951         .obj_size               = sizeof(struct tcp6_sock),
1952         .slab_flags             = SLAB_DESTROY_BY_RCU,
1953         .twsk_prot              = &tcp6_timewait_sock_ops,
1954         .rsk_prot               = &tcp6_request_sock_ops,
1955         .h.hashinfo             = &tcp_hashinfo,
1956         .no_autobind            = true,
1957 #ifdef CONFIG_COMPAT
1958         .compat_setsockopt      = compat_tcp_setsockopt,
1959         .compat_getsockopt      = compat_tcp_getsockopt,
1960 #endif
1961 #ifdef CONFIG_MEMCG_KMEM
1962         .proto_cgroup           = tcp_proto_cgroup,
1963 #endif
1964 };
1965
1966 static const struct inet6_protocol tcpv6_protocol = {
1967         .early_demux    =       tcp_v6_early_demux,
1968         .handler        =       tcp_v6_rcv,
1969         .err_handler    =       tcp_v6_err,
1970         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1971 };
1972
1973 static struct inet_protosw tcpv6_protosw = {
1974         .type           =       SOCK_STREAM,
1975         .protocol       =       IPPROTO_TCP,
1976         .prot           =       &tcpv6_prot,
1977         .ops            =       &inet6_stream_ops,
1978         .no_check       =       0,
1979         .flags          =       INET_PROTOSW_PERMANENT |
1980                                 INET_PROTOSW_ICSK,
1981 };
1982
1983 static int __net_init tcpv6_net_init(struct net *net)
1984 {
1985         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1986                                     SOCK_RAW, IPPROTO_TCP, net);
1987 }
1988
1989 static void __net_exit tcpv6_net_exit(struct net *net)
1990 {
1991         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1992 }
1993
1994 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1995 {
1996         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1997 }
1998
1999 static struct pernet_operations tcpv6_net_ops = {
2000         .init       = tcpv6_net_init,
2001         .exit       = tcpv6_net_exit,
2002         .exit_batch = tcpv6_net_exit_batch,
2003 };
2004
2005 int __init tcpv6_init(void)
2006 {
2007         int ret;
2008
2009         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2010         if (ret)
2011                 goto out;
2012
2013         /* register inet6 protocol */
2014         ret = inet6_register_protosw(&tcpv6_protosw);
2015         if (ret)
2016                 goto out_tcpv6_protocol;
2017
2018         ret = register_pernet_subsys(&tcpv6_net_ops);
2019         if (ret)
2020                 goto out_tcpv6_protosw;
2021 out:
2022         return ret;
2023
2024 out_tcpv6_protosw:
2025         inet6_unregister_protosw(&tcpv6_protosw);
2026 out_tcpv6_protocol:
2027         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2028         goto out;
2029 }
2030
2031 void tcpv6_exit(void)
2032 {
2033         unregister_pernet_subsys(&tcpv6_net_ops);
2034         inet6_unregister_protosw(&tcpv6_protosw);
2035         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2036 }