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/busy_poll.h>
  65
  66 #include <linux/proc_fs.h>
  67 #include <linux/seq_file.h>
  68
  69 #include <linux/crypto.h>
  70 #include <linux/scatterlist.h>
  71
  72 static void     tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
  73 static void     tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
  74                                       struct request_sock *req);
  75
  76 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  77
  78 static const struct inet_connection_sock_af_ops ipv6_mapped;
  79 static const struct inet_connection_sock_af_ops ipv6_specific;
  80 #ifdef CONFIG_TCP_MD5SIG
  81 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  83 #else
  84 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
  85                                                    const struct in6_addr *addr)
  86 {
  87         return NULL;
  88 }
  89 #endif
  90
  91 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  92 {
  93         struct dst_entry *dst = skb_dst(skb);
  94
  95         if (dst && dst_hold_safe(dst)) {
  96                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  97
  98                 sk->sk_rx_dst = dst;
  99                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 100                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 101         }
 102 }
 103
 104 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 105 {
 106         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 107                                             ipv6_hdr(skb)->saddr.s6_addr32,
 108                                             tcp_hdr(skb)->dest,
 109                                             tcp_hdr(skb)->source);
 110 }
 111
 112 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 113                           int addr_len)
 114 {
 115         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 116         struct inet_sock *inet = inet_sk(sk);
 117         struct inet_connection_sock *icsk = inet_csk(sk);
 118         struct ipv6_pinfo *np = inet6_sk(sk);
 119         struct tcp_sock *tp = tcp_sk(sk);
 120         struct in6_addr *saddr = NULL, *final_p, final;
 121         struct ipv6_txoptions *opt;
 122         struct flowi6 fl6;
 123         struct dst_entry *dst;
 124         int addr_type;
 125         int err;
 126
 127         if (addr_len < SIN6_LEN_RFC2133)
 128                 return -EINVAL;
 129
 130         if (usin->sin6_family != AF_INET6)
 131                 return -EAFNOSUPPORT;
 132
 133         memset(&fl6, 0, sizeof(fl6));
 134
 135         if (np->sndflow) {
 136                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 137                 IP6_ECN_flow_init(fl6.flowlabel);
 138                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 139                         struct ip6_flowlabel *flowlabel;
 140                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 141                         if (!flowlabel)
 142                                 return -EINVAL;
 143                         fl6_sock_release(flowlabel);
 144                 }
 145         }
 146
 147         /*
 148          *      connect() to INADDR_ANY means loopback (BSD'ism).
 149          */
 150
 151         if (ipv6_addr_any(&usin->sin6_addr))
 152                 usin->sin6_addr.s6_addr[15] = 0x1;
 153
 154         addr_type = ipv6_addr_type(&usin->sin6_addr);
 155
 156         if (addr_type & IPV6_ADDR_MULTICAST)
 157                 return -ENETUNREACH;
 158
 159         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 160                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 161                     usin->sin6_scope_id) {
 162                         /* If interface is set while binding, indices
 163                          * must coincide.
 164                          */
 165                         if (sk->sk_bound_dev_if &&
 166                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 167                                 return -EINVAL;
 168
 169                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 170                 }
 171
 172                 /* Connect to link-local address requires an interface */
 173                 if (!sk->sk_bound_dev_if)
 174                         return -EINVAL;
 175         }
 176
 177         if (tp->rx_opt.ts_recent_stamp &&
 178             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 179                 tp->rx_opt.ts_recent = 0;
 180                 tp->rx_opt.ts_recent_stamp = 0;
 181                 tp->write_seq = 0;
 182         }
 183
 184         sk->sk_v6_daddr = usin->sin6_addr;
 185         np->flow_label = fl6.flowlabel;
 186
 187         /*
 188          *      TCP over IPv4
 189          */
 190
 191         if (addr_type == IPV6_ADDR_MAPPED) {
 192                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 193                 struct sockaddr_in sin;
 194
 195                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 196
 197                 if (__ipv6_only_sock(sk))
 198                         return -ENETUNREACH;
 199
 200                 sin.sin_family = AF_INET;
 201                 sin.sin_port = usin->sin6_port;
 202                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 203
 204                 icsk->icsk_af_ops = &ipv6_mapped;
 205                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 206 #ifdef CONFIG_TCP_MD5SIG
 207                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 208 #endif
 209
 210                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 211
 212                 if (err) {
 213                         icsk->icsk_ext_hdr_len = exthdrlen;
 214                         icsk->icsk_af_ops = &ipv6_specific;
 215                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 216 #ifdef CONFIG_TCP_MD5SIG
 217                         tp->af_specific = &tcp_sock_ipv6_specific;
 218 #endif
 219                         goto failure;
 220                 }
 221                 np->saddr = sk->sk_v6_rcv_saddr;
 222
 223                 return err;
 224         }
 225
 226         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 227                 saddr = &sk->sk_v6_rcv_saddr;
 228
 229         fl6.flowi6_proto = IPPROTO_TCP;
 230         fl6.daddr = sk->sk_v6_daddr;
 231         fl6.saddr = saddr ? *saddr : np->saddr;
 232         fl6.flowi6_oif = sk->sk_bound_dev_if;
 233         fl6.flowi6_mark = sk->sk_mark;
 234         fl6.fl6_dport = usin->sin6_port;
 235         fl6.fl6_sport = inet->inet_sport;
 236
 237         opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
 238         final_p = fl6_update_dst(&fl6, 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 (opt)
 267                 icsk->icsk_ext_hdr_len = opt->opt_flen +
 268                                          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(const struct sock *sk, struct dst_entry *dst,
 438                               struct flowi *fl,
 439                               struct request_sock *req,
 440                               struct tcp_fastopen_cookie *foc,
 441                               bool attach_req)
 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,
 451                                                IPPROTO_TCP)) == NULL)
 452                 goto done;
 453
 454         skb = tcp_make_synack(sk, dst, req, foc, attach_req);
 455
 456         if (skb) {
 457                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 458                                     &ireq->ir_v6_rmt_addr);
 459
 460                 fl6->daddr = ireq->ir_v6_rmt_addr;
 461                 if (np->repflow && ireq->pktopts)
 462                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 463
 464                 rcu_read_lock();
 465                 err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt),
 466                                np->tclass);
 467                 rcu_read_unlock();
 468                 err = net_xmit_eval(err);
 469         }
 470
 471 done:
 472         return err;
 473 }
 474
 475
 476 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 477 {
 478         kfree_skb(inet_rsk(req)->pktopts);
 479 }
 480
 481 #ifdef CONFIG_TCP_MD5SIG
 482 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 483                                                    const struct in6_addr *addr)
 484 {
 485         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 486 }
 487
 488 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 489                                                 const struct sock *addr_sk)
 490 {
 491         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 492 }
 493
 494 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 495                                  int optlen)
 496 {
 497         struct tcp_md5sig cmd;
 498         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 499
 500         if (optlen < sizeof(cmd))
 501                 return -EINVAL;
 502
 503         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 504                 return -EFAULT;
 505
 506         if (sin6->sin6_family != AF_INET6)
 507                 return -EINVAL;
 508
 509         if (!cmd.tcpm_keylen) {
 510                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 511                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 512                                               AF_INET);
 513                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 514                                       AF_INET6);
 515         }
 516
 517         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 518                 return -EINVAL;
 519
 520         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 521                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 522                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 523
 524         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 525                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 526 }
 527
 528 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 529                                         const struct in6_addr *daddr,
 530                                         const struct in6_addr *saddr, int nbytes)
 531 {
 532         struct tcp6_pseudohdr *bp;
 533         struct scatterlist sg;
 534
 535         bp = &hp->md5_blk.ip6;
 536         /* 1. TCP pseudo-header (RFC2460) */
 537         bp->saddr = *saddr;
 538         bp->daddr = *daddr;
 539         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 540         bp->len = cpu_to_be32(nbytes);
 541
 542         sg_init_one(&sg, bp, sizeof(*bp));
 543         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 544 }
 545
 546 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 547                                const struct in6_addr *daddr, struct in6_addr *saddr,
 548                                const struct tcphdr *th)
 549 {
 550         struct tcp_md5sig_pool *hp;
 551         struct hash_desc *desc;
 552
 553         hp = tcp_get_md5sig_pool();
 554         if (!hp)
 555                 goto clear_hash_noput;
 556         desc = &hp->md5_desc;
 557
 558         if (crypto_hash_init(desc))
 559                 goto clear_hash;
 560         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 561                 goto clear_hash;
 562         if (tcp_md5_hash_header(hp, th))
 563                 goto clear_hash;
 564         if (tcp_md5_hash_key(hp, key))
 565                 goto clear_hash;
 566         if (crypto_hash_final(desc, md5_hash))
 567                 goto clear_hash;
 568
 569         tcp_put_md5sig_pool();
 570         return 0;
 571
 572 clear_hash:
 573         tcp_put_md5sig_pool();
 574 clear_hash_noput:
 575         memset(md5_hash, 0, 16);
 576         return 1;
 577 }
 578
 579 static int tcp_v6_md5_hash_skb(char *md5_hash,
 580                                const struct tcp_md5sig_key *key,
 581                                const struct sock *sk,
 582                                const struct sk_buff *skb)
 583 {
 584         const struct in6_addr *saddr, *daddr;
 585         struct tcp_md5sig_pool *hp;
 586         struct hash_desc *desc;
 587         const struct tcphdr *th = tcp_hdr(skb);
 588
 589         if (sk) { /* valid for establish/request sockets */
 590                 saddr = &sk->sk_v6_rcv_saddr;
 591                 daddr = &sk->sk_v6_daddr;
 592         } else {
 593                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 594                 saddr = &ip6h->saddr;
 595                 daddr = &ip6h->daddr;
 596         }
 597
 598         hp = tcp_get_md5sig_pool();
 599         if (!hp)
 600                 goto clear_hash_noput;
 601         desc = &hp->md5_desc;
 602
 603         if (crypto_hash_init(desc))
 604                 goto clear_hash;
 605
 606         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 607                 goto clear_hash;
 608         if (tcp_md5_hash_header(hp, th))
 609                 goto clear_hash;
 610         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 611                 goto clear_hash;
 612         if (tcp_md5_hash_key(hp, key))
 613                 goto clear_hash;
 614         if (crypto_hash_final(desc, md5_hash))
 615                 goto clear_hash;
 616
 617         tcp_put_md5sig_pool();
 618         return 0;
 619
 620 clear_hash:
 621         tcp_put_md5sig_pool();
 622 clear_hash_noput:
 623         memset(md5_hash, 0, 16);
 624         return 1;
 625 }
 626
 627 #endif
 628
 629 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 630                                     const struct sk_buff *skb)
 631 {
 632 #ifdef CONFIG_TCP_MD5SIG
 633         const __u8 *hash_location = NULL;
 634         struct tcp_md5sig_key *hash_expected;
 635         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 636         const struct tcphdr *th = tcp_hdr(skb);
 637         int genhash;
 638         u8 newhash[16];
 639
 640         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 641         hash_location = tcp_parse_md5sig_option(th);
 642
 643         /* We've parsed the options - do we have a hash? */
 644         if (!hash_expected && !hash_location)
 645                 return false;
 646
 647         if (hash_expected && !hash_location) {
 648                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 649                 return true;
 650         }
 651
 652         if (!hash_expected && hash_location) {
 653                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 654                 return true;
 655         }
 656
 657         /* check the signature */
 658         genhash = tcp_v6_md5_hash_skb(newhash,
 659                                       hash_expected,
 660                                       NULL, skb);
 661
 662         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 663                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 664                                      genhash ? "failed" : "mismatch",
 665                                      &ip6h->saddr, ntohs(th->source),
 666                                      &ip6h->daddr, ntohs(th->dest));
 667                 return true;
 668         }
 669 #endif
 670         return false;
 671 }
 672
 673 static void tcp_v6_init_req(struct request_sock *req,
 674                             const struct sock *sk_listener,
 675                             struct sk_buff *skb)
 676 {
 677         struct inet_request_sock *ireq = inet_rsk(req);
 678         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 679
 680         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 681         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 682
 683         /* So that link locals have meaning */
 684         if (!sk_listener->sk_bound_dev_if &&
 685             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 686                 ireq->ir_iif = tcp_v6_iif(skb);
 687
 688         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 689             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 690              np->rxopt.bits.rxinfo ||
 691              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 692              np->rxopt.bits.rxohlim || np->repflow)) {
 693                 atomic_inc(&skb->users);
 694                 ireq->pktopts = skb;
 695         }
 696 }
 697
 698 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 699                                           struct flowi *fl,
 700                                           const struct request_sock *req,
 701                                           bool *strict)
 702 {
 703         if (strict)
 704                 *strict = true;
 705         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 706 }
 707
 708 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 709         .family         =       AF_INET6,
 710         .obj_size       =       sizeof(struct tcp6_request_sock),
 711         .rtx_syn_ack    =       tcp_rtx_synack,
 712         .send_ack       =       tcp_v6_reqsk_send_ack,
 713         .destructor     =       tcp_v6_reqsk_destructor,
 714         .send_reset     =       tcp_v6_send_reset,
 715         .syn_ack_timeout =      tcp_syn_ack_timeout,
 716 };
 717
 718 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 719         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 720                                 sizeof(struct ipv6hdr),
 721 #ifdef CONFIG_TCP_MD5SIG
 722         .req_md5_lookup =       tcp_v6_md5_lookup,
 723         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 724 #endif
 725         .init_req       =       tcp_v6_init_req,
 726 #ifdef CONFIG_SYN_COOKIES
 727         .cookie_init_seq =      cookie_v6_init_sequence,
 728 #endif
 729         .route_req      =       tcp_v6_route_req,
 730         .init_seq       =       tcp_v6_init_sequence,
 731         .send_synack    =       tcp_v6_send_synack,
 732 };
 733
 734 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 735                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 736                                  int oif, struct tcp_md5sig_key *key, int rst,
 737                                  u8 tclass, u32 label)
 738 {
 739         const struct tcphdr *th = tcp_hdr(skb);
 740         struct tcphdr *t1;
 741         struct sk_buff *buff;
 742         struct flowi6 fl6;
 743         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 744         struct sock *ctl_sk = net->ipv6.tcp_sk;
 745         unsigned int tot_len = sizeof(struct tcphdr);
 746         struct dst_entry *dst;
 747         __be32 *topt;
 748
 749         if (tsecr)
 750                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 751 #ifdef CONFIG_TCP_MD5SIG
 752         if (key)
 753                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 754 #endif
 755
 756         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 757                          GFP_ATOMIC);
 758         if (!buff)
 759                 return;
 760
 761         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 762
 763         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 764         skb_reset_transport_header(buff);
 765
 766         /* Swap the send and the receive. */
 767         memset(t1, 0, sizeof(*t1));
 768         t1->dest = th->source;
 769         t1->source = th->dest;
 770         t1->doff = tot_len / 4;
 771         t1->seq = htonl(seq);
 772         t1->ack_seq = htonl(ack);
 773         t1->ack = !rst || !th->ack;
 774         t1->rst = rst;
 775         t1->window = htons(win);
 776
 777         topt = (__be32 *)(t1 + 1);
 778
 779         if (tsecr) {
 780                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 781                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 782                 *topt++ = htonl(tsval);
 783                 *topt++ = htonl(tsecr);
 784         }
 785
 786 #ifdef CONFIG_TCP_MD5SIG
 787         if (key) {
 788                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 789                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 790                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 791                                     &ipv6_hdr(skb)->saddr,
 792                                     &ipv6_hdr(skb)->daddr, t1);
 793         }
 794 #endif
 795
 796         memset(&fl6, 0, sizeof(fl6));
 797         fl6.daddr = ipv6_hdr(skb)->saddr;
 798         fl6.saddr = ipv6_hdr(skb)->daddr;
 799         fl6.flowlabel = label;
 800
 801         buff->ip_summed = CHECKSUM_PARTIAL;
 802         buff->csum = 0;
 803
 804         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 805
 806         fl6.flowi6_proto = IPPROTO_TCP;
 807         if (rt6_need_strict(&fl6.daddr) && !oif)
 808                 fl6.flowi6_oif = tcp_v6_iif(skb);
 809         else
 810                 fl6.flowi6_oif = oif;
 811         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 812         fl6.fl6_dport = t1->dest;
 813         fl6.fl6_sport = t1->source;
 814         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 815
 816         /* Pass a socket to ip6_dst_lookup either it is for RST
 817          * Underlying function will use this to retrieve the network
 818          * namespace
 819          */
 820         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 821         if (!IS_ERR(dst)) {
 822                 skb_dst_set(buff, dst);
 823                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 824                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 825                 if (rst)
 826                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 827                 return;
 828         }
 829
 830         kfree_skb(buff);
 831 }
 832
 833 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 834 {
 835         const struct tcphdr *th = tcp_hdr(skb);
 836         u32 seq = 0, ack_seq = 0;
 837         struct tcp_md5sig_key *key = NULL;
 838 #ifdef CONFIG_TCP_MD5SIG
 839         const __u8 *hash_location = NULL;
 840         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 841         unsigned char newhash[16];
 842         int genhash;
 843         struct sock *sk1 = NULL;
 844 #endif
 845         int oif;
 846
 847         if (th->rst)
 848                 return;
 849
 850         /* If sk not NULL, it means we did a successful lookup and incoming
 851          * route had to be correct. prequeue might have dropped our dst.
 852          */
 853         if (!sk && !ipv6_unicast_destination(skb))
 854                 return;
 855
 856 #ifdef CONFIG_TCP_MD5SIG
 857         hash_location = tcp_parse_md5sig_option(th);
 858         if (sk && sk_fullsock(sk)) {
 859                 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
 860         } else if (hash_location) {
 861                 /*
 862                  * active side is lost. Try to find listening socket through
 863                  * source port, and then find md5 key through listening socket.
 864                  * we are not loose security here:
 865                  * Incoming packet is checked with md5 hash with finding key,
 866                  * no RST generated if md5 hash doesn't match.
 867                  */
 868                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 869                                            &tcp_hashinfo, &ipv6h->saddr,
 870                                            th->source, &ipv6h->daddr,
 871                                            ntohs(th->source), tcp_v6_iif(skb));
 872                 if (!sk1)
 873                         return;
 874
 875                 rcu_read_lock();
 876                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 877                 if (!key)
 878                         goto release_sk1;
 879
 880                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 881                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 882                         goto release_sk1;
 883         }
 884 #endif
 885
 886         if (th->ack)
 887                 seq = ntohl(th->ack_seq);
 888         else
 889                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 890                           (th->doff << 2);
 891
 892         oif = sk ? sk->sk_bound_dev_if : 0;
 893         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 894
 895 #ifdef CONFIG_TCP_MD5SIG
 896 release_sk1:
 897         if (sk1) {
 898                 rcu_read_unlock();
 899                 sock_put(sk1);
 900         }
 901 #endif
 902 }
 903
 904 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 905                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 906                             struct tcp_md5sig_key *key, u8 tclass,
 907                             u32 label)
 908 {
 909         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 910                              tclass, label);
 911 }
 912
 913 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 914 {
 915         struct inet_timewait_sock *tw = inet_twsk(sk);
 916         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 917
 918         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 919                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 920                         tcp_time_stamp + tcptw->tw_ts_offset,
 921                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 922                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 923
 924         inet_twsk_put(tw);
 925 }
 926
 927 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 928                                   struct request_sock *req)
 929 {
 930         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 931          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 932          */
 933         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 934                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 935                         tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd,
 936                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 937                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 938                         0, 0);
 939 }
 940
 941
 942 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
 943 {
 944 #ifdef CONFIG_SYN_COOKIES
 945         const struct tcphdr *th = tcp_hdr(skb);
 946
 947         if (!th->syn)
 948                 sk = cookie_v6_check(sk, skb);
 949 #endif
 950         return sk;
 951 }
 952
 953 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 954 {
 955         if (skb->protocol == htons(ETH_P_IP))
 956                 return tcp_v4_conn_request(sk, skb);
 957
 958         if (!ipv6_unicast_destination(skb))
 959                 goto drop;
 960
 961         return tcp_conn_request(&tcp6_request_sock_ops,
 962                                 &tcp_request_sock_ipv6_ops, sk, skb);
 963
 964 drop:
 965         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 966         return 0; /* don't send reset */
 967 }
 968
 969 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 970                                          struct request_sock *req,
 971                                          struct dst_entry *dst,
 972                                          struct request_sock *req_unhash,
 973                                          bool *own_req)
 974 {
 975         struct inet_request_sock *ireq;
 976         struct ipv6_pinfo *newnp;
 977         const struct ipv6_pinfo *np = inet6_sk(sk);
 978         struct ipv6_txoptions *opt;
 979         struct tcp6_sock *newtcp6sk;
 980         struct inet_sock *newinet;
 981         struct tcp_sock *newtp;
 982         struct sock *newsk;
 983 #ifdef CONFIG_TCP_MD5SIG
 984         struct tcp_md5sig_key *key;
 985 #endif
 986         struct flowi6 fl6;
 987
 988         if (skb->protocol == htons(ETH_P_IP)) {
 989                 /*
 990                  *      v6 mapped
 991                  */
 992
 993                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
 994                                              req_unhash, own_req);
 995
 996                 if (!newsk)
 997                         return NULL;
 998
 999                 newtcp6sk = (struct tcp6_sock *)newsk;
1000                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1001
1002                 newinet = inet_sk(newsk);
1003                 newnp = inet6_sk(newsk);
1004                 newtp = tcp_sk(newsk);
1005
1006                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1007
1008                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1009
1010                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1011                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1012 #ifdef CONFIG_TCP_MD5SIG
1013                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1014 #endif
1015
1016                 newnp->ipv6_ac_list = NULL;
1017                 newnp->ipv6_fl_list = NULL;
1018                 newnp->pktoptions  = NULL;
1019                 newnp->opt         = NULL;
1020                 newnp->mcast_oif   = tcp_v6_iif(skb);
1021                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1022                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1023                 if (np->repflow)
1024                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1025
1026                 /*
1027                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1028                  * here, tcp_create_openreq_child now does this for us, see the comment in
1029                  * that function for the gory details. -acme
1030                  */
1031
1032                 /* It is tricky place. Until this moment IPv4 tcp
1033                    worked with IPv6 icsk.icsk_af_ops.
1034                    Sync it now.
1035                  */
1036                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1037
1038                 return newsk;
1039         }
1040
1041         ireq = inet_rsk(req);
1042
1043         if (sk_acceptq_is_full(sk))
1044                 goto out_overflow;
1045
1046         if (!dst) {
1047                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1048                 if (!dst)
1049                         goto out;
1050         }
1051
1052         newsk = tcp_create_openreq_child(sk, req, skb);
1053         if (!newsk)
1054                 goto out_nonewsk;
1055
1056         /*
1057          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1058          * count here, tcp_create_openreq_child now does this for us, see the
1059          * comment in that function for the gory details. -acme
1060          */
1061
1062         newsk->sk_gso_type = SKB_GSO_TCPV6;
1063         ip6_dst_store(newsk, dst, NULL, NULL);
1064         inet6_sk_rx_dst_set(newsk, skb);
1065
1066         newtcp6sk = (struct tcp6_sock *)newsk;
1067         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1068
1069         newtp = tcp_sk(newsk);
1070         newinet = inet_sk(newsk);
1071         newnp = inet6_sk(newsk);
1072
1073         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1074
1075         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1076         newnp->saddr = ireq->ir_v6_loc_addr;
1077         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1078         newsk->sk_bound_dev_if = ireq->ir_iif;
1079
1080         /* Now IPv6 options...
1081
1082            First: no IPv4 options.
1083          */
1084         newinet->inet_opt = NULL;
1085         newnp->ipv6_ac_list = NULL;
1086         newnp->ipv6_fl_list = NULL;
1087
1088         /* Clone RX bits */
1089         newnp->rxopt.all = np->rxopt.all;
1090
1091         newnp->pktoptions = NULL;
1092         newnp->opt        = NULL;
1093         newnp->mcast_oif  = tcp_v6_iif(skb);
1094         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1095         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1096         if (np->repflow)
1097                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1098
1099         /* Clone native IPv6 options from listening socket (if any)
1100
1101            Yes, keeping reference count would be much more clever,
1102            but we make one more one thing there: reattach optmem
1103            to newsk.
1104          */
1105         opt = rcu_dereference(np->opt);
1106         if (opt) {
1107                 opt = ipv6_dup_options(newsk, opt);
1108                 RCU_INIT_POINTER(newnp->opt, opt);
1109         }
1110         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1111         if (opt)
1112                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1113                                                     opt->opt_flen;
1114
1115         tcp_ca_openreq_child(newsk, dst);
1116
1117         tcp_sync_mss(newsk, dst_mtu(dst));
1118         newtp->advmss = dst_metric_advmss(dst);
1119         if (tcp_sk(sk)->rx_opt.user_mss &&
1120             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1121                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1122
1123         tcp_initialize_rcv_mss(newsk);
1124
1125         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1126         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1127
1128 #ifdef CONFIG_TCP_MD5SIG
1129         /* Copy over the MD5 key from the original socket */
1130         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1131         if (key) {
1132                 /* We're using one, so create a matching key
1133                  * on the newsk structure. If we fail to get
1134                  * memory, then we end up not copying the key
1135                  * across. Shucks.
1136                  */
1137                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1138                                AF_INET6, key->key, key->keylen,
1139                                sk_gfp_mask(sk, GFP_ATOMIC));
1140         }
1141 #endif
1142
1143         if (__inet_inherit_port(sk, newsk) < 0) {
1144                 inet_csk_prepare_forced_close(newsk);
1145                 tcp_done(newsk);
1146                 goto out;
1147         }
1148         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1149         if (*own_req) {
1150                 tcp_move_syn(newtp, req);
1151
1152                 /* Clone pktoptions received with SYN, if we own the req */
1153                 if (ireq->pktopts) {
1154                         newnp->pktoptions = skb_clone(ireq->pktopts,
1155                                                       sk_gfp_mask(sk, GFP_ATOMIC));
1156                         consume_skb(ireq->pktopts);
1157                         ireq->pktopts = NULL;
1158                         if (newnp->pktoptions)
1159                                 skb_set_owner_r(newnp->pktoptions, newsk);
1160                 }
1161         }
1162
1163         return newsk;
1164
1165 out_overflow:
1166         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1167 out_nonewsk:
1168         dst_release(dst);
1169 out:
1170         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1171         return NULL;
1172 }
1173
1174 /* The socket must have it's spinlock held when we get
1175  * here, unless it is a TCP_LISTEN socket.
1176  *
1177  * We have a potential double-lock case here, so even when
1178  * doing backlog processing we use the BH locking scheme.
1179  * This is because we cannot sleep with the original spinlock
1180  * held.
1181  */
1182 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1183 {
1184         struct ipv6_pinfo *np = inet6_sk(sk);
1185         struct tcp_sock *tp;
1186         struct sk_buff *opt_skb = NULL;
1187
1188         /* Imagine: socket is IPv6. IPv4 packet arrives,
1189            goes to IPv4 receive handler and backlogged.
1190            From backlog it always goes here. Kerboom...
1191            Fortunately, tcp_rcv_established and rcv_established
1192            handle them correctly, but it is not case with
1193            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1194          */
1195
1196         if (skb->protocol == htons(ETH_P_IP))
1197                 return tcp_v4_do_rcv(sk, skb);
1198
1199         if (sk_filter(sk, skb))
1200                 goto discard;
1201
1202         /*
1203          *      socket locking is here for SMP purposes as backlog rcv
1204          *      is currently called with bh processing disabled.
1205          */
1206
1207         /* Do Stevens' IPV6_PKTOPTIONS.
1208
1209            Yes, guys, it is the only place in our code, where we
1210            may make it not affecting IPv4.
1211            The rest of code is protocol independent,
1212            and I do not like idea to uglify IPv4.
1213
1214            Actually, all the idea behind IPV6_PKTOPTIONS
1215            looks not very well thought. For now we latch
1216            options, received in the last packet, enqueued
1217            by tcp. Feel free to propose better solution.
1218                                                --ANK (980728)
1219          */
1220         if (np->rxopt.all)
1221                 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1222
1223         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1224                 struct dst_entry *dst = sk->sk_rx_dst;
1225
1226                 sock_rps_save_rxhash(sk, skb);
1227                 sk_mark_napi_id(sk, skb);
1228                 if (dst) {
1229                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1230                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1231                                 dst_release(dst);
1232                                 sk->sk_rx_dst = NULL;
1233                         }
1234                 }
1235
1236                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1237                 if (opt_skb)
1238                         goto ipv6_pktoptions;
1239                 return 0;
1240         }
1241
1242         if (tcp_checksum_complete(skb))
1243                 goto csum_err;
1244
1245         if (sk->sk_state == TCP_LISTEN) {
1246                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1247
1248                 if (!nsk)
1249                         goto discard;
1250
1251                 if (nsk != sk) {
1252                         sock_rps_save_rxhash(nsk, skb);
1253                         sk_mark_napi_id(nsk, skb);
1254                         if (tcp_child_process(sk, nsk, skb))
1255                                 goto reset;
1256                         if (opt_skb)
1257                                 __kfree_skb(opt_skb);
1258                         return 0;
1259                 }
1260         } else
1261                 sock_rps_save_rxhash(sk, skb);
1262
1263         if (tcp_rcv_state_process(sk, skb))
1264                 goto reset;
1265         if (opt_skb)
1266                 goto ipv6_pktoptions;
1267         return 0;
1268
1269 reset:
1270         tcp_v6_send_reset(sk, skb);
1271 discard:
1272         if (opt_skb)
1273                 __kfree_skb(opt_skb);
1274         kfree_skb(skb);
1275         return 0;
1276 csum_err:
1277         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1278         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1279         goto discard;
1280
1281
1282 ipv6_pktoptions:
1283         /* Do you ask, what is it?
1284
1285            1. skb was enqueued by tcp.
1286            2. skb is added to tail of read queue, rather than out of order.
1287            3. socket is not in passive state.
1288            4. Finally, it really contains options, which user wants to receive.
1289          */
1290         tp = tcp_sk(sk);
1291         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1292             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1293                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1294                         np->mcast_oif = tcp_v6_iif(opt_skb);
1295                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1296                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1297                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1298                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1299                 if (np->repflow)
1300                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1301                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1302                         skb_set_owner_r(opt_skb, sk);
1303                         opt_skb = xchg(&np->pktoptions, opt_skb);
1304                 } else {
1305                         __kfree_skb(opt_skb);
1306                         opt_skb = xchg(&np->pktoptions, NULL);
1307                 }
1308         }
1309
1310         kfree_skb(opt_skb);
1311         return 0;
1312 }
1313
1314 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1315                            const struct tcphdr *th)
1316 {
1317         /* This is tricky: we move IP6CB at its correct location into
1318          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1319          * _decode_session6() uses IP6CB().
1320          * barrier() makes sure compiler won't play aliasing games.
1321          */
1322         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1323                 sizeof(struct inet6_skb_parm));
1324         barrier();
1325
1326         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1327         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1328                                     skb->len - th->doff*4);
1329         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1330         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1331         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1332         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1333         TCP_SKB_CB(skb)->sacked = 0;
1334 }
1335
1336 static void tcp_v6_restore_cb(struct sk_buff *skb)
1337 {
1338         /* We need to move header back to the beginning if xfrm6_policy_check()
1339          * and tcp_v6_fill_cb() are going to be called again.
1340          */
1341         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1342                 sizeof(struct inet6_skb_parm));
1343 }
1344
1345 static int tcp_v6_rcv(struct sk_buff *skb)
1346 {
1347         const struct tcphdr *th;
1348         const struct ipv6hdr *hdr;
1349         struct sock *sk;
1350         int ret;
1351         struct net *net = dev_net(skb->dev);
1352
1353         if (skb->pkt_type != PACKET_HOST)
1354                 goto discard_it;
1355
1356         /*
1357          *      Count it even if it's bad.
1358          */
1359         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1360
1361         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1362                 goto discard_it;
1363
1364         th = tcp_hdr(skb);
1365
1366         if (th->doff < sizeof(struct tcphdr)/4)
1367                 goto bad_packet;
1368         if (!pskb_may_pull(skb, th->doff*4))
1369                 goto discard_it;
1370
1371         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1372                 goto csum_error;
1373
1374         th = tcp_hdr(skb);
1375         hdr = ipv6_hdr(skb);
1376
1377 lookup:
1378         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1379                                 inet6_iif(skb));
1380         if (!sk)
1381                 goto no_tcp_socket;
1382
1383 process:
1384         if (sk->sk_state == TCP_TIME_WAIT)
1385                 goto do_time_wait;
1386
1387         if (sk->sk_state == TCP_NEW_SYN_RECV) {
1388                 struct request_sock *req = inet_reqsk(sk);
1389                 struct sock *nsk = NULL;
1390
1391                 sk = req->rsk_listener;
1392                 tcp_v6_fill_cb(skb, hdr, th);
1393                 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1394                         reqsk_put(req);
1395                         goto discard_it;
1396                 }
1397                 if (likely(sk->sk_state == TCP_LISTEN)) {
1398                         nsk = tcp_check_req(sk, skb, req, false);
1399                 } else {
1400                         inet_csk_reqsk_queue_drop_and_put(sk, req);
1401                         goto lookup;
1402                 }
1403                 if (!nsk) {
1404                         reqsk_put(req);
1405                         goto discard_it;
1406                 }
1407                 if (nsk == sk) {
1408                         sock_hold(sk);
1409                         reqsk_put(req);
1410                         tcp_v6_restore_cb(skb);
1411                 } else if (tcp_child_process(sk, nsk, skb)) {
1412                         tcp_v6_send_reset(nsk, skb);
1413                         goto discard_it;
1414                 } else {
1415                         return 0;
1416                 }
1417         }
1418         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1419                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1420                 goto discard_and_relse;
1421         }
1422
1423         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1424                 goto discard_and_relse;
1425
1426         tcp_v6_fill_cb(skb, hdr, th);
1427
1428         if (tcp_v6_inbound_md5_hash(sk, skb))
1429                 goto discard_and_relse;
1430
1431         if (sk_filter(sk, skb))
1432                 goto discard_and_relse;
1433
1434         skb->dev = NULL;
1435
1436         if (sk->sk_state == TCP_LISTEN) {
1437                 ret = tcp_v6_do_rcv(sk, skb);
1438                 goto put_and_return;
1439         }
1440
1441         sk_incoming_cpu_update(sk);
1442
1443         bh_lock_sock_nested(sk);
1444         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1445         ret = 0;
1446         if (!sock_owned_by_user(sk)) {
1447                 if (!tcp_prequeue(sk, skb))
1448                         ret = tcp_v6_do_rcv(sk, skb);
1449         } else if (unlikely(sk_add_backlog(sk, skb,
1450                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1451                 bh_unlock_sock(sk);
1452                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1453                 goto discard_and_relse;
1454         }
1455         bh_unlock_sock(sk);
1456
1457 put_and_return:
1458         sock_put(sk);
1459         return ret ? -1 : 0;
1460
1461 no_tcp_socket:
1462         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1463                 goto discard_it;
1464
1465         tcp_v6_fill_cb(skb, hdr, th);
1466
1467         if (tcp_checksum_complete(skb)) {
1468 csum_error:
1469                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1470 bad_packet:
1471                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1472         } else {
1473                 tcp_v6_send_reset(NULL, skb);
1474         }
1475
1476 discard_it:
1477         kfree_skb(skb);
1478         return 0;
1479
1480 discard_and_relse:
1481         sock_put(sk);
1482         goto discard_it;
1483
1484 do_time_wait:
1485         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1486                 inet_twsk_put(inet_twsk(sk));
1487                 goto discard_it;
1488         }
1489
1490         tcp_v6_fill_cb(skb, hdr, th);
1491
1492         if (tcp_checksum_complete(skb)) {
1493                 inet_twsk_put(inet_twsk(sk));
1494                 goto csum_error;
1495         }
1496
1497         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1498         case TCP_TW_SYN:
1499         {
1500                 struct sock *sk2;
1501
1502                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1503                                             &ipv6_hdr(skb)->saddr, th->source,
1504                                             &ipv6_hdr(skb)->daddr,
1505                                             ntohs(th->dest), tcp_v6_iif(skb));
1506                 if (sk2) {
1507                         struct inet_timewait_sock *tw = inet_twsk(sk);
1508                         inet_twsk_deschedule_put(tw);
1509                         sk = sk2;
1510                         tcp_v6_restore_cb(skb);
1511                         goto process;
1512                 }
1513                 /* Fall through to ACK */
1514         }
1515         case TCP_TW_ACK:
1516                 tcp_v6_timewait_ack(sk, skb);
1517                 break;
1518         case TCP_TW_RST:
1519                 tcp_v6_restore_cb(skb);
1520                 tcp_v6_send_reset(sk, skb);
1521                 inet_twsk_deschedule_put(inet_twsk(sk));
1522                 goto discard_it;
1523         case TCP_TW_SUCCESS:
1524                 ;
1525         }
1526         goto discard_it;
1527 }
1528
1529 static void tcp_v6_early_demux(struct sk_buff *skb)
1530 {
1531         const struct ipv6hdr *hdr;
1532         const struct tcphdr *th;
1533         struct sock *sk;
1534
1535         if (skb->pkt_type != PACKET_HOST)
1536                 return;
1537
1538         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1539                 return;
1540
1541         hdr = ipv6_hdr(skb);
1542         th = tcp_hdr(skb);
1543
1544         if (th->doff < sizeof(struct tcphdr) / 4)
1545                 return;
1546
1547         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1548         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1549                                         &hdr->saddr, th->source,
1550                                         &hdr->daddr, ntohs(th->dest),
1551                                         inet6_iif(skb));
1552         if (sk) {
1553                 skb->sk = sk;
1554                 skb->destructor = sock_edemux;
1555                 if (sk_fullsock(sk)) {
1556                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1557
1558                         if (dst)
1559                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1560                         if (dst &&
1561                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1562                                 skb_dst_set_noref(skb, dst);
1563                 }
1564         }
1565 }
1566
1567 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1568         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1569         .twsk_unique    = tcp_twsk_unique,
1570         .twsk_destructor = tcp_twsk_destructor,
1571 };
1572
1573 static const struct inet_connection_sock_af_ops ipv6_specific = {
1574         .queue_xmit        = inet6_csk_xmit,
1575         .send_check        = tcp_v6_send_check,
1576         .rebuild_header    = inet6_sk_rebuild_header,
1577         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1578         .conn_request      = tcp_v6_conn_request,
1579         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1580         .net_header_len    = sizeof(struct ipv6hdr),
1581         .net_frag_header_len = sizeof(struct frag_hdr),
1582         .setsockopt        = ipv6_setsockopt,
1583         .getsockopt        = ipv6_getsockopt,
1584         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1585         .sockaddr_len      = sizeof(struct sockaddr_in6),
1586         .bind_conflict     = inet6_csk_bind_conflict,
1587 #ifdef CONFIG_COMPAT
1588         .compat_setsockopt = compat_ipv6_setsockopt,
1589         .compat_getsockopt = compat_ipv6_getsockopt,
1590 #endif
1591         .mtu_reduced       = tcp_v6_mtu_reduced,
1592 };
1593
1594 #ifdef CONFIG_TCP_MD5SIG
1595 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1596         .md5_lookup     =       tcp_v6_md5_lookup,
1597         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1598         .md5_parse      =       tcp_v6_parse_md5_keys,
1599 };
1600 #endif
1601
1602 /*
1603  *      TCP over IPv4 via INET6 API
1604  */
1605 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1606         .queue_xmit        = ip_queue_xmit,
1607         .send_check        = tcp_v4_send_check,
1608         .rebuild_header    = inet_sk_rebuild_header,
1609         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1610         .conn_request      = tcp_v6_conn_request,
1611         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1612         .net_header_len    = sizeof(struct iphdr),
1613         .setsockopt        = ipv6_setsockopt,
1614         .getsockopt        = ipv6_getsockopt,
1615         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1616         .sockaddr_len      = sizeof(struct sockaddr_in6),
1617         .bind_conflict     = inet6_csk_bind_conflict,
1618 #ifdef CONFIG_COMPAT
1619         .compat_setsockopt = compat_ipv6_setsockopt,
1620         .compat_getsockopt = compat_ipv6_getsockopt,
1621 #endif
1622         .mtu_reduced       = tcp_v4_mtu_reduced,
1623 };
1624
1625 #ifdef CONFIG_TCP_MD5SIG
1626 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1627         .md5_lookup     =       tcp_v4_md5_lookup,
1628         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1629         .md5_parse      =       tcp_v6_parse_md5_keys,
1630 };
1631 #endif
1632
1633 /* NOTE: A lot of things set to zero explicitly by call to
1634  *       sk_alloc() so need not be done here.
1635  */
1636 static int tcp_v6_init_sock(struct sock *sk)
1637 {
1638         struct inet_connection_sock *icsk = inet_csk(sk);
1639
1640         tcp_init_sock(sk);
1641
1642         icsk->icsk_af_ops = &ipv6_specific;
1643
1644 #ifdef CONFIG_TCP_MD5SIG
1645         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1646 #endif
1647
1648         return 0;
1649 }
1650
1651 static void tcp_v6_destroy_sock(struct sock *sk)
1652 {
1653         tcp_v4_destroy_sock(sk);
1654         inet6_destroy_sock(sk);
1655 }
1656
1657 #ifdef CONFIG_PROC_FS
1658 /* Proc filesystem TCPv6 sock list dumping. */
1659 static void get_openreq6(struct seq_file *seq,
1660                          const struct request_sock *req, int i)
1661 {
1662         long ttd = req->rsk_timer.expires - jiffies;
1663         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1664         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1665
1666         if (ttd < 0)
1667                 ttd = 0;
1668
1669         seq_printf(seq,
1670                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1671                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1672                    i,
1673                    src->s6_addr32[0], src->s6_addr32[1],
1674                    src->s6_addr32[2], src->s6_addr32[3],
1675                    inet_rsk(req)->ir_num,
1676                    dest->s6_addr32[0], dest->s6_addr32[1],
1677                    dest->s6_addr32[2], dest->s6_addr32[3],
1678                    ntohs(inet_rsk(req)->ir_rmt_port),
1679                    TCP_SYN_RECV,
1680                    0, 0, /* could print option size, but that is af dependent. */
1681                    1,   /* timers active (only the expire timer) */
1682                    jiffies_to_clock_t(ttd),
1683                    req->num_timeout,
1684                    from_kuid_munged(seq_user_ns(seq),
1685                                     sock_i_uid(req->rsk_listener)),
1686                    0,  /* non standard timer */
1687                    0, /* open_requests have no inode */
1688                    0, req);
1689 }
1690
1691 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1692 {
1693         const struct in6_addr *dest, *src;
1694         __u16 destp, srcp;
1695         int timer_active;
1696         unsigned long timer_expires;
1697         const struct inet_sock *inet = inet_sk(sp);
1698         const struct tcp_sock *tp = tcp_sk(sp);
1699         const struct inet_connection_sock *icsk = inet_csk(sp);
1700         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1701         int rx_queue;
1702         int state;
1703
1704         dest  = &sp->sk_v6_daddr;
1705         src   = &sp->sk_v6_rcv_saddr;
1706         destp = ntohs(inet->inet_dport);
1707         srcp  = ntohs(inet->inet_sport);
1708
1709         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1710                 timer_active    = 1;
1711                 timer_expires   = icsk->icsk_timeout;
1712         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1713                 timer_active    = 4;
1714                 timer_expires   = icsk->icsk_timeout;
1715         } else if (timer_pending(&sp->sk_timer)) {
1716                 timer_active    = 2;
1717                 timer_expires   = sp->sk_timer.expires;
1718         } else {
1719                 timer_active    = 0;
1720                 timer_expires = jiffies;
1721         }
1722
1723         state = sk_state_load(sp);
1724         if (state == TCP_LISTEN)
1725                 rx_queue = sp->sk_ack_backlog;
1726         else
1727                 /* Because we don't lock the socket,
1728                  * we might find a transient negative value.
1729                  */
1730                 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1731
1732         seq_printf(seq,
1733                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1734                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1735                    i,
1736                    src->s6_addr32[0], src->s6_addr32[1],
1737                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1738                    dest->s6_addr32[0], dest->s6_addr32[1],
1739                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1740                    state,
1741                    tp->write_seq - tp->snd_una,
1742                    rx_queue,
1743                    timer_active,
1744                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1745                    icsk->icsk_retransmits,
1746                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1747                    icsk->icsk_probes_out,
1748                    sock_i_ino(sp),
1749                    atomic_read(&sp->sk_refcnt), sp,
1750                    jiffies_to_clock_t(icsk->icsk_rto),
1751                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1752                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1753                    tp->snd_cwnd,
1754                    state == TCP_LISTEN ?
1755                         fastopenq->max_qlen :
1756                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1757                    );
1758 }
1759
1760 static void get_timewait6_sock(struct seq_file *seq,
1761                                struct inet_timewait_sock *tw, int i)
1762 {
1763         long delta = tw->tw_timer.expires - jiffies;
1764         const struct in6_addr *dest, *src;
1765         __u16 destp, srcp;
1766
1767         dest = &tw->tw_v6_daddr;
1768         src  = &tw->tw_v6_rcv_saddr;
1769         destp = ntohs(tw->tw_dport);
1770         srcp  = ntohs(tw->tw_sport);
1771
1772         seq_printf(seq,
1773                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1774                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1775                    i,
1776                    src->s6_addr32[0], src->s6_addr32[1],
1777                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1778                    dest->s6_addr32[0], dest->s6_addr32[1],
1779                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1780                    tw->tw_substate, 0, 0,
1781                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1782                    atomic_read(&tw->tw_refcnt), tw);
1783 }
1784
1785 static int tcp6_seq_show(struct seq_file *seq, void *v)
1786 {
1787         struct tcp_iter_state *st;
1788         struct sock *sk = v;
1789
1790         if (v == SEQ_START_TOKEN) {
1791                 seq_puts(seq,
1792                          "  sl  "
1793                          "local_address                         "
1794                          "remote_address                        "
1795                          "st tx_queue rx_queue tr tm->when retrnsmt"
1796                          "   uid  timeout inode\n");
1797                 goto out;
1798         }
1799         st = seq->private;
1800
1801         if (sk->sk_state == TCP_TIME_WAIT)
1802                 get_timewait6_sock(seq, v, st->num);
1803         else if (sk->sk_state == TCP_NEW_SYN_RECV)
1804                 get_openreq6(seq, v, st->num);
1805         else
1806                 get_tcp6_sock(seq, v, st->num);
1807 out:
1808         return 0;
1809 }
1810
1811 static const struct file_operations tcp6_afinfo_seq_fops = {
1812         .owner   = THIS_MODULE,
1813         .open    = tcp_seq_open,
1814         .read    = seq_read,
1815         .llseek  = seq_lseek,
1816         .release = seq_release_net
1817 };
1818
1819 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1820         .name           = "tcp6",
1821         .family         = AF_INET6,
1822         .seq_fops       = &tcp6_afinfo_seq_fops,
1823         .seq_ops        = {
1824                 .show           = tcp6_seq_show,
1825         },
1826 };
1827
1828 int __net_init tcp6_proc_init(struct net *net)
1829 {
1830         return tcp_proc_register(net, &tcp6_seq_afinfo);
1831 }
1832
1833 void tcp6_proc_exit(struct net *net)
1834 {
1835         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1836 }
1837 #endif
1838
1839 static void tcp_v6_clear_sk(struct sock *sk, int size)
1840 {
1841         struct inet_sock *inet = inet_sk(sk);
1842
1843         /* we do not want to clear pinet6 field, because of RCU lookups */
1844         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1845
1846         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1847         memset(&inet->pinet6 + 1, 0, size);
1848 }
1849
1850 struct proto tcpv6_prot = {
1851         .name                   = "TCPv6",
1852         .owner                  = THIS_MODULE,
1853         .close                  = tcp_close,
1854         .connect                = tcp_v6_connect,
1855         .disconnect             = tcp_disconnect,
1856         .accept                 = inet_csk_accept,
1857         .ioctl                  = tcp_ioctl,
1858         .init                   = tcp_v6_init_sock,
1859         .destroy                = tcp_v6_destroy_sock,
1860         .shutdown               = tcp_shutdown,
1861         .setsockopt             = tcp_setsockopt,
1862         .getsockopt             = tcp_getsockopt,
1863         .recvmsg                = tcp_recvmsg,
1864         .sendmsg                = tcp_sendmsg,
1865         .sendpage               = tcp_sendpage,
1866         .backlog_rcv            = tcp_v6_do_rcv,
1867         .release_cb             = tcp_release_cb,
1868         .hash                   = inet6_hash,
1869         .unhash                 = inet_unhash,
1870         .get_port               = inet_csk_get_port,
1871         .enter_memory_pressure  = tcp_enter_memory_pressure,
1872         .stream_memory_free     = tcp_stream_memory_free,
1873         .sockets_allocated      = &tcp_sockets_allocated,
1874         .memory_allocated       = &tcp_memory_allocated,
1875         .memory_pressure        = &tcp_memory_pressure,
1876         .orphan_count           = &tcp_orphan_count,
1877         .sysctl_mem             = sysctl_tcp_mem,
1878         .sysctl_wmem            = sysctl_tcp_wmem,
1879         .sysctl_rmem            = sysctl_tcp_rmem,
1880         .max_header             = MAX_TCP_HEADER,
1881         .obj_size               = sizeof(struct tcp6_sock),
1882         .slab_flags             = SLAB_DESTROY_BY_RCU,
1883         .twsk_prot              = &tcp6_timewait_sock_ops,
1884         .rsk_prot               = &tcp6_request_sock_ops,
1885         .h.hashinfo             = &tcp_hashinfo,
1886         .no_autobind            = true,
1887 #ifdef CONFIG_COMPAT
1888         .compat_setsockopt      = compat_tcp_setsockopt,
1889         .compat_getsockopt      = compat_tcp_getsockopt,
1890 #endif
1891         .clear_sk               = tcp_v6_clear_sk,
1892         .diag_destroy           = tcp_abort,
1893 };
1894
1895 static const struct inet6_protocol tcpv6_protocol = {
1896         .early_demux    =       tcp_v6_early_demux,
1897         .handler        =       tcp_v6_rcv,
1898         .err_handler    =       tcp_v6_err,
1899         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1900 };
1901
1902 static struct inet_protosw tcpv6_protosw = {
1903         .type           =       SOCK_STREAM,
1904         .protocol       =       IPPROTO_TCP,
1905         .prot           =       &tcpv6_prot,
1906         .ops            =       &inet6_stream_ops,
1907         .flags          =       INET_PROTOSW_PERMANENT |
1908                                 INET_PROTOSW_ICSK,
1909 };
1910
1911 static int __net_init tcpv6_net_init(struct net *net)
1912 {
1913         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1914                                     SOCK_RAW, IPPROTO_TCP, net);
1915 }
1916
1917 static void __net_exit tcpv6_net_exit(struct net *net)
1918 {
1919         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1920 }
1921
1922 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1923 {
1924         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1925 }
1926
1927 static struct pernet_operations tcpv6_net_ops = {
1928         .init       = tcpv6_net_init,
1929         .exit       = tcpv6_net_exit,
1930         .exit_batch = tcpv6_net_exit_batch,
1931 };
1932
1933 int __init tcpv6_init(void)
1934 {
1935         int ret;
1936
1937         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1938         if (ret)
1939                 goto out;
1940
1941         /* register inet6 protocol */
1942         ret = inet6_register_protosw(&tcpv6_protosw);
1943         if (ret)
1944                 goto out_tcpv6_protocol;
1945
1946         ret = register_pernet_subsys(&tcpv6_net_ops);
1947         if (ret)
1948                 goto out_tcpv6_protosw;
1949 out:
1950         return ret;
1951
1952 out_tcpv6_protosw:
1953         inet6_unregister_protosw(&tcpv6_protosw);
1954 out_tcpv6_protocol:
1955         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1956         goto out;
1957 }
1958
1959 void tcpv6_exit(void)
1960 {
1961         unregister_pernet_subsys(&tcpv6_net_ops);
1962         inet6_unregister_protosw(&tcpv6_protosw);
1963         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1964 }