net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/inet_common.h>
  63 #include <net/secure_seq.h>
  64 #include <net/tcp_memcontrol.h>
  65 #include <net/busy_poll.h>
  66
  67 #include <linux/proc_fs.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <linux/crypto.h>
  71 #include <linux/scatterlist.h>
  72
  73 static void     tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
  74 static void     tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
  75                                       struct request_sock *req);
  76
  77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  78
  79 static const struct inet_connection_sock_af_ops ipv6_mapped;
  80 static const struct inet_connection_sock_af_ops ipv6_specific;
  81 #ifdef CONFIG_TCP_MD5SIG
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  83 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  84 #else
  85 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  86                                                    const struct in6_addr *addr)
  87 {
  88         return NULL;
  89 }
  90 #endif
  91
  92 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  93 {
  94         struct dst_entry *dst = skb_dst(skb);
  95
  96         if (dst) {
  97                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  98
  99                 dst_hold(dst);
 100                 sk->sk_rx_dst = dst;
 101                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 102                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 103         }
 104 }
 105
 106 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 107 {
 108         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 109                                             ipv6_hdr(skb)->saddr.s6_addr32,
 110                                             tcp_hdr(skb)->dest,
 111                                             tcp_hdr(skb)->source);
 112 }
 113
 114 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 115                           int addr_len)
 116 {
 117         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 118         struct inet_sock *inet = inet_sk(sk);
 119         struct inet_connection_sock *icsk = inet_csk(sk);
 120         struct ipv6_pinfo *np = inet6_sk(sk);
 121         struct tcp_sock *tp = tcp_sk(sk);
 122         struct in6_addr *saddr = NULL, *final_p, final;
 123         struct flowi6 fl6;
 124         struct dst_entry *dst;
 125         int addr_type;
 126         int err;
 127
 128         if (addr_len < SIN6_LEN_RFC2133)
 129                 return -EINVAL;
 130
 131         if (usin->sin6_family != AF_INET6)
 132                 return -EAFNOSUPPORT;
 133
 134         memset(&fl6, 0, sizeof(fl6));
 135
 136         if (np->sndflow) {
 137                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 138                 IP6_ECN_flow_init(fl6.flowlabel);
 139                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 140                         struct ip6_flowlabel *flowlabel;
 141                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 142                         if (!flowlabel)
 143                                 return -EINVAL;
 144                         fl6_sock_release(flowlabel);
 145                 }
 146         }
 147
 148         /*
 149          *      connect() to INADDR_ANY means loopback (BSD'ism).
 150          */
 151
 152         if (ipv6_addr_any(&usin->sin6_addr))
 153                 usin->sin6_addr.s6_addr[15] = 0x1;
 154
 155         addr_type = ipv6_addr_type(&usin->sin6_addr);
 156
 157         if (addr_type & IPV6_ADDR_MULTICAST)
 158                 return -ENETUNREACH;
 159
 160         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 161                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 162                     usin->sin6_scope_id) {
 163                         /* If interface is set while binding, indices
 164                          * must coincide.
 165                          */
 166                         if (sk->sk_bound_dev_if &&
 167                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 168                                 return -EINVAL;
 169
 170                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 171                 }
 172
 173                 /* Connect to link-local address requires an interface */
 174                 if (!sk->sk_bound_dev_if)
 175                         return -EINVAL;
 176         }
 177
 178         if (tp->rx_opt.ts_recent_stamp &&
 179             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 180                 tp->rx_opt.ts_recent = 0;
 181                 tp->rx_opt.ts_recent_stamp = 0;
 182                 tp->write_seq = 0;
 183         }
 184
 185         sk->sk_v6_daddr = usin->sin6_addr;
 186         np->flow_label = fl6.flowlabel;
 187
 188         /*
 189          *      TCP over IPv4
 190          */
 191
 192         if (addr_type == IPV6_ADDR_MAPPED) {
 193                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 194                 struct sockaddr_in sin;
 195
 196                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 197
 198                 if (__ipv6_only_sock(sk))
 199                         return -ENETUNREACH;
 200
 201                 sin.sin_family = AF_INET;
 202                 sin.sin_port = usin->sin6_port;
 203                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 204
 205                 icsk->icsk_af_ops = &ipv6_mapped;
 206                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 207 #ifdef CONFIG_TCP_MD5SIG
 208                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 209 #endif
 210
 211                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 212
 213                 if (err) {
 214                         icsk->icsk_ext_hdr_len = exthdrlen;
 215                         icsk->icsk_af_ops = &ipv6_specific;
 216                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 217 #ifdef CONFIG_TCP_MD5SIG
 218                         tp->af_specific = &tcp_sock_ipv6_specific;
 219 #endif
 220                         goto failure;
 221                 }
 222                 np->saddr = sk->sk_v6_rcv_saddr;
 223
 224                 return err;
 225         }
 226
 227         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 228                 saddr = &sk->sk_v6_rcv_saddr;
 229
 230         fl6.flowi6_proto = IPPROTO_TCP;
 231         fl6.daddr = sk->sk_v6_daddr;
 232         fl6.saddr = saddr ? *saddr : np->saddr;
 233         fl6.flowi6_oif = sk->sk_bound_dev_if;
 234         fl6.flowi6_mark = sk->sk_mark;
 235         fl6.fl6_dport = usin->sin6_port;
 236         fl6.fl6_sport = inet->inet_sport;
 237
 238         final_p = fl6_update_dst(&fl6, np->opt, &final);
 239
 240         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 241
 242         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 243         if (IS_ERR(dst)) {
 244                 err = PTR_ERR(dst);
 245                 goto failure;
 246         }
 247
 248         if (!saddr) {
 249                 saddr = &fl6.saddr;
 250                 sk->sk_v6_rcv_saddr = *saddr;
 251         }
 252
 253         /* set the source address */
 254         np->saddr = *saddr;
 255         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 256
 257         sk->sk_gso_type = SKB_GSO_TCPV6;
 258         __ip6_dst_store(sk, dst, NULL, NULL);
 259
 260         if (tcp_death_row.sysctl_tw_recycle &&
 261             !tp->rx_opt.ts_recent_stamp &&
 262             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 263                 tcp_fetch_timewait_stamp(sk, dst);
 264
 265         icsk->icsk_ext_hdr_len = 0;
 266         if (np->opt)
 267                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 268                                           np->opt->opt_nflen);
 269
 270         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 271
 272         inet->inet_dport = usin->sin6_port;
 273
 274         tcp_set_state(sk, TCP_SYN_SENT);
 275         err = inet6_hash_connect(&tcp_death_row, sk);
 276         if (err)
 277                 goto late_failure;
 278
 279         sk_set_txhash(sk);
 280
 281         if (!tp->write_seq && likely(!tp->repair))
 282                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 283                                                              sk->sk_v6_daddr.s6_addr32,
 284                                                              inet->inet_sport,
 285                                                              inet->inet_dport);
 286
 287         err = tcp_connect(sk);
 288         if (err)
 289                 goto late_failure;
 290
 291         return 0;
 292
 293 late_failure:
 294         tcp_set_state(sk, TCP_CLOSE);
 295         __sk_dst_reset(sk);
 296 failure:
 297         inet->inet_dport = 0;
 298         sk->sk_route_caps = 0;
 299         return err;
 300 }
 301
 302 static void tcp_v6_mtu_reduced(struct sock *sk)
 303 {
 304         struct dst_entry *dst;
 305
 306         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 307                 return;
 308
 309         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 310         if (!dst)
 311                 return;
 312
 313         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 314                 tcp_sync_mss(sk, dst_mtu(dst));
 315                 tcp_simple_retransmit(sk);
 316         }
 317 }
 318
 319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 320                 u8 type, u8 code, int offset, __be32 info)
 321 {
 322         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 324         struct net *net = dev_net(skb->dev);
 325         struct request_sock *fastopen;
 326         struct ipv6_pinfo *np;
 327         struct tcp_sock *tp;
 328         __u32 seq, snd_una;
 329         struct sock *sk;
 330         int err;
 331
 332         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 333                                         &hdr->daddr, th->dest,
 334                                         &hdr->saddr, ntohs(th->source),
 335                                         skb->dev->ifindex);
 336
 337         if (!sk) {
 338                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 339                                    ICMP6_MIB_INERRORS);
 340                 return;
 341         }
 342
 343         if (sk->sk_state == TCP_TIME_WAIT) {
 344                 inet_twsk_put(inet_twsk(sk));
 345                 return;
 346         }
 347         seq = ntohl(th->seq);
 348         if (sk->sk_state == TCP_NEW_SYN_RECV)
 349                 return tcp_req_err(sk, seq);
 350
 351         bh_lock_sock(sk);
 352         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 353                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 354
 355         if (sk->sk_state == TCP_CLOSE)
 356                 goto out;
 357
 358         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 359                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 360                 goto out;
 361         }
 362
 363         tp = tcp_sk(sk);
 364         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 365         fastopen = tp->fastopen_rsk;
 366         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 367         if (sk->sk_state != TCP_LISTEN &&
 368             !between(seq, snd_una, tp->snd_nxt)) {
 369                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 370                 goto out;
 371         }
 372
 373         np = inet6_sk(sk);
 374
 375         if (type == NDISC_REDIRECT) {
 376                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 377
 378                 if (dst)
 379                         dst->ops->redirect(dst, sk, skb);
 380                 goto out;
 381         }
 382
 383         if (type == ICMPV6_PKT_TOOBIG) {
 384                 /* We are not interested in TCP_LISTEN and open_requests
 385                  * (SYN-ACKs send out by Linux are always <576bytes so
 386                  * they should go through unfragmented).
 387                  */
 388                 if (sk->sk_state == TCP_LISTEN)
 389                         goto out;
 390
 391                 if (!ip6_sk_accept_pmtu(sk))
 392                         goto out;
 393
 394                 tp->mtu_info = ntohl(info);
 395                 if (!sock_owned_by_user(sk))
 396                         tcp_v6_mtu_reduced(sk);
 397                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 398                                            &tp->tsq_flags))
 399                         sock_hold(sk);
 400                 goto out;
 401         }
 402
 403         icmpv6_err_convert(type, code, &err);
 404
 405         /* Might be for an request_sock */
 406         switch (sk->sk_state) {
 407         case TCP_SYN_SENT:
 408         case TCP_SYN_RECV:
 409                 /* Only in fast or simultaneous open. If a fast open socket is
 410                  * is already accepted it is treated as a connected one below.
 411                  */
 412                 if (fastopen && !fastopen->sk)
 413                         break;
 414
 415                 if (!sock_owned_by_user(sk)) {
 416                         sk->sk_err = err;
 417                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 418
 419                         tcp_done(sk);
 420                 } else
 421                         sk->sk_err_soft = err;
 422                 goto out;
 423         }
 424
 425         if (!sock_owned_by_user(sk) && np->recverr) {
 426                 sk->sk_err = err;
 427                 sk->sk_error_report(sk);
 428         } else
 429                 sk->sk_err_soft = err;
 430
 431 out:
 432         bh_unlock_sock(sk);
 433         sock_put(sk);
 434 }
 435
 436
 437 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 438                               struct flowi *fl,
 439                               struct request_sock *req,
 440                               u16 queue_mapping,
 441                               struct tcp_fastopen_cookie *foc)
 442 {
 443         struct inet_request_sock *ireq = inet_rsk(req);
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct flowi6 *fl6 = &fl->u.ip6;
 446         struct sk_buff *skb;
 447         int err = -ENOMEM;
 448
 449         /* First, grab a route. */
 450         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
 451                 goto done;
 452
 453         skb = tcp_make_synack(sk, dst, req, foc);
 454
 455         if (skb) {
 456                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 457                                     &ireq->ir_v6_rmt_addr);
 458
 459                 fl6->daddr = ireq->ir_v6_rmt_addr;
 460                 if (np->repflow && ireq->pktopts)
 461                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 462
 463                 skb_set_queue_mapping(skb, queue_mapping);
 464                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 465                 err = net_xmit_eval(err);
 466         }
 467
 468 done:
 469         return err;
 470 }
 471
 472
 473 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 474 {
 475         kfree_skb(inet_rsk(req)->pktopts);
 476 }
 477
 478 #ifdef CONFIG_TCP_MD5SIG
 479 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 480                                                    const struct in6_addr *addr)
 481 {
 482         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 483 }
 484
 485 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 486                                                 const struct sock *addr_sk)
 487 {
 488         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 489 }
 490
 491 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 492                                  int optlen)
 493 {
 494         struct tcp_md5sig cmd;
 495         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 496
 497         if (optlen < sizeof(cmd))
 498                 return -EINVAL;
 499
 500         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 501                 return -EFAULT;
 502
 503         if (sin6->sin6_family != AF_INET6)
 504                 return -EINVAL;
 505
 506         if (!cmd.tcpm_keylen) {
 507                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 508                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 509                                               AF_INET);
 510                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 511                                       AF_INET6);
 512         }
 513
 514         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 515                 return -EINVAL;
 516
 517         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 518                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 519                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 520
 521         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 522                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 523 }
 524
 525 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 526                                         const struct in6_addr *daddr,
 527                                         const struct in6_addr *saddr, int nbytes)
 528 {
 529         struct tcp6_pseudohdr *bp;
 530         struct scatterlist sg;
 531
 532         bp = &hp->md5_blk.ip6;
 533         /* 1. TCP pseudo-header (RFC2460) */
 534         bp->saddr = *saddr;
 535         bp->daddr = *daddr;
 536         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 537         bp->len = cpu_to_be32(nbytes);
 538
 539         sg_init_one(&sg, bp, sizeof(*bp));
 540         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 541 }
 542
 543 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 544                                const struct in6_addr *daddr, struct in6_addr *saddr,
 545                                const struct tcphdr *th)
 546 {
 547         struct tcp_md5sig_pool *hp;
 548         struct hash_desc *desc;
 549
 550         hp = tcp_get_md5sig_pool();
 551         if (!hp)
 552                 goto clear_hash_noput;
 553         desc = &hp->md5_desc;
 554
 555         if (crypto_hash_init(desc))
 556                 goto clear_hash;
 557         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 558                 goto clear_hash;
 559         if (tcp_md5_hash_header(hp, th))
 560                 goto clear_hash;
 561         if (tcp_md5_hash_key(hp, key))
 562                 goto clear_hash;
 563         if (crypto_hash_final(desc, md5_hash))
 564                 goto clear_hash;
 565
 566         tcp_put_md5sig_pool();
 567         return 0;
 568
 569 clear_hash:
 570         tcp_put_md5sig_pool();
 571 clear_hash_noput:
 572         memset(md5_hash, 0, 16);
 573         return 1;
 574 }
 575
 576 static int tcp_v6_md5_hash_skb(char *md5_hash,
 577                                const struct tcp_md5sig_key *key,
 578                                const struct sock *sk,
 579                                const struct sk_buff *skb)
 580 {
 581         const struct in6_addr *saddr, *daddr;
 582         struct tcp_md5sig_pool *hp;
 583         struct hash_desc *desc;
 584         const struct tcphdr *th = tcp_hdr(skb);
 585
 586         if (sk) { /* valid for establish/request sockets */
 587                 saddr = &sk->sk_v6_rcv_saddr;
 588                 daddr = &sk->sk_v6_daddr;
 589         } else {
 590                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 591                 saddr = &ip6h->saddr;
 592                 daddr = &ip6h->daddr;
 593         }
 594
 595         hp = tcp_get_md5sig_pool();
 596         if (!hp)
 597                 goto clear_hash_noput;
 598         desc = &hp->md5_desc;
 599
 600         if (crypto_hash_init(desc))
 601                 goto clear_hash;
 602
 603         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 604                 goto clear_hash;
 605         if (tcp_md5_hash_header(hp, th))
 606                 goto clear_hash;
 607         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 608                 goto clear_hash;
 609         if (tcp_md5_hash_key(hp, key))
 610                 goto clear_hash;
 611         if (crypto_hash_final(desc, md5_hash))
 612                 goto clear_hash;
 613
 614         tcp_put_md5sig_pool();
 615         return 0;
 616
 617 clear_hash:
 618         tcp_put_md5sig_pool();
 619 clear_hash_noput:
 620         memset(md5_hash, 0, 16);
 621         return 1;
 622 }
 623
 624 static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 625 {
 626         const __u8 *hash_location = NULL;
 627         struct tcp_md5sig_key *hash_expected;
 628         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 629         const struct tcphdr *th = tcp_hdr(skb);
 630         int genhash;
 631         u8 newhash[16];
 632
 633         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 634         hash_location = tcp_parse_md5sig_option(th);
 635
 636         /* We've parsed the options - do we have a hash? */
 637         if (!hash_expected && !hash_location)
 638                 return false;
 639
 640         if (hash_expected && !hash_location) {
 641                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 642                 return true;
 643         }
 644
 645         if (!hash_expected && hash_location) {
 646                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 647                 return true;
 648         }
 649
 650         /* check the signature */
 651         genhash = tcp_v6_md5_hash_skb(newhash,
 652                                       hash_expected,
 653                                       NULL, skb);
 654
 655         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 656                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 657                                      genhash ? "failed" : "mismatch",
 658                                      &ip6h->saddr, ntohs(th->source),
 659                                      &ip6h->daddr, ntohs(th->dest));
 660                 return true;
 661         }
 662         return false;
 663 }
 664 #endif
 665
 666 static void tcp_v6_init_req(struct request_sock *req,
 667                             const struct sock *sk_listener,
 668                             struct sk_buff *skb)
 669 {
 670         struct inet_request_sock *ireq = inet_rsk(req);
 671         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 672
 673         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 674         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 675
 676         /* So that link locals have meaning */
 677         if (!sk_listener->sk_bound_dev_if &&
 678             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 679                 ireq->ir_iif = tcp_v6_iif(skb);
 680
 681         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 682             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 683              np->rxopt.bits.rxinfo ||
 684              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 685              np->rxopt.bits.rxohlim || np->repflow)) {
 686                 atomic_inc(&skb->users);
 687                 ireq->pktopts = skb;
 688         }
 689 }
 690
 691 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 692                                           const struct request_sock *req,
 693                                           bool *strict)
 694 {
 695         if (strict)
 696                 *strict = true;
 697         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 698 }
 699
 700 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 701         .family         =       AF_INET6,
 702         .obj_size       =       sizeof(struct tcp6_request_sock),
 703         .rtx_syn_ack    =       tcp_rtx_synack,
 704         .send_ack       =       tcp_v6_reqsk_send_ack,
 705         .destructor     =       tcp_v6_reqsk_destructor,
 706         .send_reset     =       tcp_v6_send_reset,
 707         .syn_ack_timeout =      tcp_syn_ack_timeout,
 708 };
 709
 710 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 711         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 712                                 sizeof(struct ipv6hdr),
 713 #ifdef CONFIG_TCP_MD5SIG
 714         .req_md5_lookup =       tcp_v6_md5_lookup,
 715         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 716 #endif
 717         .init_req       =       tcp_v6_init_req,
 718 #ifdef CONFIG_SYN_COOKIES
 719         .cookie_init_seq =      cookie_v6_init_sequence,
 720 #endif
 721         .route_req      =       tcp_v6_route_req,
 722         .init_seq       =       tcp_v6_init_sequence,
 723         .send_synack    =       tcp_v6_send_synack,
 724         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 725 };
 726
 727 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 728                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 729                                  int oif, struct tcp_md5sig_key *key, int rst,
 730                                  u8 tclass, u32 label)
 731 {
 732         const struct tcphdr *th = tcp_hdr(skb);
 733         struct tcphdr *t1;
 734         struct sk_buff *buff;
 735         struct flowi6 fl6;
 736         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 737         struct sock *ctl_sk = net->ipv6.tcp_sk;
 738         unsigned int tot_len = sizeof(struct tcphdr);
 739         struct dst_entry *dst;
 740         __be32 *topt;
 741
 742         if (tsecr)
 743                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 744 #ifdef CONFIG_TCP_MD5SIG
 745         if (key)
 746                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 747 #endif
 748
 749         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 750                          GFP_ATOMIC);
 751         if (!buff)
 752                 return;
 753
 754         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 755
 756         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 757         skb_reset_transport_header(buff);
 758
 759         /* Swap the send and the receive. */
 760         memset(t1, 0, sizeof(*t1));
 761         t1->dest = th->source;
 762         t1->source = th->dest;
 763         t1->doff = tot_len / 4;
 764         t1->seq = htonl(seq);
 765         t1->ack_seq = htonl(ack);
 766         t1->ack = !rst || !th->ack;
 767         t1->rst = rst;
 768         t1->window = htons(win);
 769
 770         topt = (__be32 *)(t1 + 1);
 771
 772         if (tsecr) {
 773                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 774                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 775                 *topt++ = htonl(tsval);
 776                 *topt++ = htonl(tsecr);
 777         }
 778
 779 #ifdef CONFIG_TCP_MD5SIG
 780         if (key) {
 781                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 782                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 783                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 784                                     &ipv6_hdr(skb)->saddr,
 785                                     &ipv6_hdr(skb)->daddr, t1);
 786         }
 787 #endif
 788
 789         memset(&fl6, 0, sizeof(fl6));
 790         fl6.daddr = ipv6_hdr(skb)->saddr;
 791         fl6.saddr = ipv6_hdr(skb)->daddr;
 792         fl6.flowlabel = label;
 793
 794         buff->ip_summed = CHECKSUM_PARTIAL;
 795         buff->csum = 0;
 796
 797         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 798
 799         fl6.flowi6_proto = IPPROTO_TCP;
 800         if (rt6_need_strict(&fl6.daddr) && !oif)
 801                 fl6.flowi6_oif = tcp_v6_iif(skb);
 802         else
 803                 fl6.flowi6_oif = oif;
 804         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 805         fl6.fl6_dport = t1->dest;
 806         fl6.fl6_sport = t1->source;
 807         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 808
 809         /* Pass a socket to ip6_dst_lookup either it is for RST
 810          * Underlying function will use this to retrieve the network
 811          * namespace
 812          */
 813         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 814         if (!IS_ERR(dst)) {
 815                 skb_dst_set(buff, dst);
 816                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 817                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 818                 if (rst)
 819                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 820                 return;
 821         }
 822
 823         kfree_skb(buff);
 824 }
 825
 826 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 827 {
 828         const struct tcphdr *th = tcp_hdr(skb);
 829         u32 seq = 0, ack_seq = 0;
 830         struct tcp_md5sig_key *key = NULL;
 831 #ifdef CONFIG_TCP_MD5SIG
 832         const __u8 *hash_location = NULL;
 833         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 834         unsigned char newhash[16];
 835         int genhash;
 836         struct sock *sk1 = NULL;
 837 #endif
 838         int oif;
 839
 840         if (th->rst)
 841                 return;
 842
 843         /* If sk not NULL, it means we did a successful lookup and incoming
 844          * route had to be correct. prequeue might have dropped our dst.
 845          */
 846         if (!sk && !ipv6_unicast_destination(skb))
 847                 return;
 848
 849 #ifdef CONFIG_TCP_MD5SIG
 850         hash_location = tcp_parse_md5sig_option(th);
 851         if (!sk && hash_location) {
 852                 /*
 853                  * active side is lost. Try to find listening socket through
 854                  * source port, and then find md5 key through listening socket.
 855                  * we are not loose security here:
 856                  * Incoming packet is checked with md5 hash with finding key,
 857                  * no RST generated if md5 hash doesn't match.
 858                  */
 859                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 860                                            &tcp_hashinfo, &ipv6h->saddr,
 861                                            th->source, &ipv6h->daddr,
 862                                            ntohs(th->source), tcp_v6_iif(skb));
 863                 if (!sk1)
 864                         return;
 865
 866                 rcu_read_lock();
 867                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 868                 if (!key)
 869                         goto release_sk1;
 870
 871                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 872                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 873                         goto release_sk1;
 874         } else {
 875                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 876         }
 877 #endif
 878
 879         if (th->ack)
 880                 seq = ntohl(th->ack_seq);
 881         else
 882                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 883                           (th->doff << 2);
 884
 885         oif = sk ? sk->sk_bound_dev_if : 0;
 886         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 887
 888 #ifdef CONFIG_TCP_MD5SIG
 889 release_sk1:
 890         if (sk1) {
 891                 rcu_read_unlock();
 892                 sock_put(sk1);
 893         }
 894 #endif
 895 }
 896
 897 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 898                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 899                             struct tcp_md5sig_key *key, u8 tclass,
 900                             u32 label)
 901 {
 902         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 903                              tclass, label);
 904 }
 905
 906 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 907 {
 908         struct inet_timewait_sock *tw = inet_twsk(sk);
 909         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 910
 911         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 912                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 913                         tcp_time_stamp + tcptw->tw_ts_offset,
 914                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 915                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 916
 917         inet_twsk_put(tw);
 918 }
 919
 920 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 921                                   struct request_sock *req)
 922 {
 923         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 924          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 925          */
 926         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 927                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 928                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 929                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 930                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 931                         0, 0);
 932 }
 933
 934
 935 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 936 {
 937         const struct tcphdr *th = tcp_hdr(skb);
 938         struct request_sock *req;
 939         struct sock *nsk;
 940
 941         /* Find possible connection requests. */
 942         req = inet6_csk_search_req(sk, th->source,
 943                                    &ipv6_hdr(skb)->saddr,
 944                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 945         if (req) {
 946                 nsk = tcp_check_req(sk, skb, req, false);
 947                 if (!nsk || nsk == sk)
 948                         reqsk_put(req);
 949                 return nsk;
 950         }
 951         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 952                                          &ipv6_hdr(skb)->saddr, th->source,
 953                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 954                                          tcp_v6_iif(skb));
 955
 956         if (nsk) {
 957                 if (nsk->sk_state != TCP_TIME_WAIT) {
 958                         bh_lock_sock(nsk);
 959                         return nsk;
 960                 }
 961                 inet_twsk_put(inet_twsk(nsk));
 962                 return NULL;
 963         }
 964
 965 #ifdef CONFIG_SYN_COOKIES
 966         if (!th->syn)
 967                 sk = cookie_v6_check(sk, skb);
 968 #endif
 969         return sk;
 970 }
 971
 972 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 973 {
 974         if (skb->protocol == htons(ETH_P_IP))
 975                 return tcp_v4_conn_request(sk, skb);
 976
 977         if (!ipv6_unicast_destination(skb))
 978                 goto drop;
 979
 980         return tcp_conn_request(&tcp6_request_sock_ops,
 981                                 &tcp_request_sock_ipv6_ops, sk, skb);
 982
 983 drop:
 984         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 985         return 0; /* don't send reset */
 986 }
 987
 988 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 989                                          struct request_sock *req,
 990                                          struct dst_entry *dst)
 991 {
 992         struct inet_request_sock *ireq;
 993         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 994         struct tcp6_sock *newtcp6sk;
 995         struct inet_sock *newinet;
 996         struct tcp_sock *newtp;
 997         struct sock *newsk;
 998 #ifdef CONFIG_TCP_MD5SIG
 999         struct tcp_md5sig_key *key;
1000 #endif
1001         struct flowi6 fl6;
1002
1003         if (skb->protocol == htons(ETH_P_IP)) {
1004                 /*
1005                  *      v6 mapped
1006                  */
1007
1008                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1009
1010                 if (!newsk)
1011                         return NULL;
1012
1013                 newtcp6sk = (struct tcp6_sock *)newsk;
1014                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1015
1016                 newinet = inet_sk(newsk);
1017                 newnp = inet6_sk(newsk);
1018                 newtp = tcp_sk(newsk);
1019
1020                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1021
1022                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1023
1024                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1025                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1026 #ifdef CONFIG_TCP_MD5SIG
1027                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1028 #endif
1029
1030                 newnp->ipv6_ac_list = NULL;
1031                 newnp->ipv6_fl_list = NULL;
1032                 newnp->pktoptions  = NULL;
1033                 newnp->opt         = NULL;
1034                 newnp->mcast_oif   = tcp_v6_iif(skb);
1035                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1036                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1037                 if (np->repflow)
1038                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1039
1040                 /*
1041                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1042                  * here, tcp_create_openreq_child now does this for us, see the comment in
1043                  * that function for the gory details. -acme
1044                  */
1045
1046                 /* It is tricky place. Until this moment IPv4 tcp
1047                    worked with IPv6 icsk.icsk_af_ops.
1048                    Sync it now.
1049                  */
1050                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1051
1052                 return newsk;
1053         }
1054
1055         ireq = inet_rsk(req);
1056
1057         if (sk_acceptq_is_full(sk))
1058                 goto out_overflow;
1059
1060         if (!dst) {
1061                 dst = inet6_csk_route_req(sk, &fl6, req);
1062                 if (!dst)
1063                         goto out;
1064         }
1065
1066         newsk = tcp_create_openreq_child(sk, req, skb);
1067         if (!newsk)
1068                 goto out_nonewsk;
1069
1070         /*
1071          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1072          * count here, tcp_create_openreq_child now does this for us, see the
1073          * comment in that function for the gory details. -acme
1074          */
1075
1076         newsk->sk_gso_type = SKB_GSO_TCPV6;
1077         __ip6_dst_store(newsk, dst, NULL, NULL);
1078         inet6_sk_rx_dst_set(newsk, skb);
1079
1080         newtcp6sk = (struct tcp6_sock *)newsk;
1081         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1082
1083         newtp = tcp_sk(newsk);
1084         newinet = inet_sk(newsk);
1085         newnp = inet6_sk(newsk);
1086
1087         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1088
1089         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1090         newnp->saddr = ireq->ir_v6_loc_addr;
1091         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1092         newsk->sk_bound_dev_if = ireq->ir_iif;
1093
1094         /* Now IPv6 options...
1095
1096            First: no IPv4 options.
1097          */
1098         newinet->inet_opt = NULL;
1099         newnp->ipv6_ac_list = NULL;
1100         newnp->ipv6_fl_list = NULL;
1101
1102         /* Clone RX bits */
1103         newnp->rxopt.all = np->rxopt.all;
1104
1105         /* Clone pktoptions received with SYN */
1106         newnp->pktoptions = NULL;
1107         if (ireq->pktopts) {
1108                 newnp->pktoptions = skb_clone(ireq->pktopts,
1109                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1110                 consume_skb(ireq->pktopts);
1111                 ireq->pktopts = NULL;
1112                 if (newnp->pktoptions)
1113                         skb_set_owner_r(newnp->pktoptions, newsk);
1114         }
1115         newnp->opt        = NULL;
1116         newnp->mcast_oif  = tcp_v6_iif(skb);
1117         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1118         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1119         if (np->repflow)
1120                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1121
1122         /* Clone native IPv6 options from listening socket (if any)
1123
1124            Yes, keeping reference count would be much more clever,
1125            but we make one more one thing there: reattach optmem
1126            to newsk.
1127          */
1128         if (np->opt)
1129                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1130
1131         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1132         if (newnp->opt)
1133                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1134                                                      newnp->opt->opt_flen);
1135
1136         tcp_ca_openreq_child(newsk, dst);
1137
1138         tcp_sync_mss(newsk, dst_mtu(dst));
1139         newtp->advmss = dst_metric_advmss(dst);
1140         if (tcp_sk(sk)->rx_opt.user_mss &&
1141             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1142                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1143
1144         tcp_initialize_rcv_mss(newsk);
1145
1146         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1147         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1148
1149 #ifdef CONFIG_TCP_MD5SIG
1150         /* Copy over the MD5 key from the original socket */
1151         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1152         if (key) {
1153                 /* We're using one, so create a matching key
1154                  * on the newsk structure. If we fail to get
1155                  * memory, then we end up not copying the key
1156                  * across. Shucks.
1157                  */
1158                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1159                                AF_INET6, key->key, key->keylen,
1160                                sk_gfp_atomic(sk, GFP_ATOMIC));
1161         }
1162 #endif
1163
1164         if (__inet_inherit_port(sk, newsk) < 0) {
1165                 inet_csk_prepare_forced_close(newsk);
1166                 tcp_done(newsk);
1167                 goto out;
1168         }
1169         __inet_hash(newsk, NULL);
1170
1171         return newsk;
1172
1173 out_overflow:
1174         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1175 out_nonewsk:
1176         dst_release(dst);
1177 out:
1178         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1179         return NULL;
1180 }
1181
1182 /* The socket must have it's spinlock held when we get
1183  * here.
1184  *
1185  * We have a potential double-lock case here, so even when
1186  * doing backlog processing we use the BH locking scheme.
1187  * This is because we cannot sleep with the original spinlock
1188  * held.
1189  */
1190 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1191 {
1192         struct ipv6_pinfo *np = inet6_sk(sk);
1193         struct tcp_sock *tp;
1194         struct sk_buff *opt_skb = NULL;
1195
1196         /* Imagine: socket is IPv6. IPv4 packet arrives,
1197            goes to IPv4 receive handler and backlogged.
1198            From backlog it always goes here. Kerboom...
1199            Fortunately, tcp_rcv_established and rcv_established
1200            handle them correctly, but it is not case with
1201            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1202          */
1203
1204         if (skb->protocol == htons(ETH_P_IP))
1205                 return tcp_v4_do_rcv(sk, skb);
1206
1207         if (sk_filter(sk, skb))
1208                 goto discard;
1209
1210         /*
1211          *      socket locking is here for SMP purposes as backlog rcv
1212          *      is currently called with bh processing disabled.
1213          */
1214
1215         /* Do Stevens' IPV6_PKTOPTIONS.
1216
1217            Yes, guys, it is the only place in our code, where we
1218            may make it not affecting IPv4.
1219            The rest of code is protocol independent,
1220            and I do not like idea to uglify IPv4.
1221
1222            Actually, all the idea behind IPV6_PKTOPTIONS
1223            looks not very well thought. For now we latch
1224            options, received in the last packet, enqueued
1225            by tcp. Feel free to propose better solution.
1226                                                --ANK (980728)
1227          */
1228         if (np->rxopt.all)
1229                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1230
1231         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1232                 struct dst_entry *dst = sk->sk_rx_dst;
1233
1234                 sock_rps_save_rxhash(sk, skb);
1235                 sk_mark_napi_id(sk, skb);
1236                 if (dst) {
1237                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1238                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1239                                 dst_release(dst);
1240                                 sk->sk_rx_dst = NULL;
1241                         }
1242                 }
1243
1244                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1245                 if (opt_skb)
1246                         goto ipv6_pktoptions;
1247                 return 0;
1248         }
1249
1250         if (tcp_checksum_complete(skb))
1251                 goto csum_err;
1252
1253         if (sk->sk_state == TCP_LISTEN) {
1254                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1255                 if (!nsk)
1256                         goto discard;
1257
1258                 /*
1259                  * Queue it on the new socket if the new socket is active,
1260                  * otherwise we just shortcircuit this and continue with
1261                  * the new socket..
1262                  */
1263                 if (nsk != sk) {
1264                         sock_rps_save_rxhash(nsk, skb);
1265                         sk_mark_napi_id(sk, skb);
1266                         if (tcp_child_process(sk, nsk, skb))
1267                                 goto reset;
1268                         if (opt_skb)
1269                                 __kfree_skb(opt_skb);
1270                         return 0;
1271                 }
1272         } else
1273                 sock_rps_save_rxhash(sk, skb);
1274
1275         if (tcp_rcv_state_process(sk, skb))
1276                 goto reset;
1277         if (opt_skb)
1278                 goto ipv6_pktoptions;
1279         return 0;
1280
1281 reset:
1282         tcp_v6_send_reset(sk, skb);
1283 discard:
1284         if (opt_skb)
1285                 __kfree_skb(opt_skb);
1286         kfree_skb(skb);
1287         return 0;
1288 csum_err:
1289         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1290         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1291         goto discard;
1292
1293
1294 ipv6_pktoptions:
1295         /* Do you ask, what is it?
1296
1297            1. skb was enqueued by tcp.
1298            2. skb is added to tail of read queue, rather than out of order.
1299            3. socket is not in passive state.
1300            4. Finally, it really contains options, which user wants to receive.
1301          */
1302         tp = tcp_sk(sk);
1303         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1304             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1305                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1306                         np->mcast_oif = tcp_v6_iif(opt_skb);
1307                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1308                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1309                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1310                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1311                 if (np->repflow)
1312                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1313                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1314                         skb_set_owner_r(opt_skb, sk);
1315                         opt_skb = xchg(&np->pktoptions, opt_skb);
1316                 } else {
1317                         __kfree_skb(opt_skb);
1318                         opt_skb = xchg(&np->pktoptions, NULL);
1319                 }
1320         }
1321
1322         kfree_skb(opt_skb);
1323         return 0;
1324 }
1325
1326 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1327                            const struct tcphdr *th)
1328 {
1329         /* This is tricky: we move IP6CB at its correct location into
1330          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1331          * _decode_session6() uses IP6CB().
1332          * barrier() makes sure compiler won't play aliasing games.
1333          */
1334         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1335                 sizeof(struct inet6_skb_parm));
1336         barrier();
1337
1338         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1339         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1340                                     skb->len - th->doff*4);
1341         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1342         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1343         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1344         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1345         TCP_SKB_CB(skb)->sacked = 0;
1346 }
1347
1348 static void tcp_v6_restore_cb(struct sk_buff *skb)
1349 {
1350         /* We need to move header back to the beginning if xfrm6_policy_check()
1351          * and tcp_v6_fill_cb() are going to be called again.
1352          */
1353         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1354                 sizeof(struct inet6_skb_parm));
1355 }
1356
1357 static int tcp_v6_rcv(struct sk_buff *skb)
1358 {
1359         const struct tcphdr *th;
1360         const struct ipv6hdr *hdr;
1361         struct sock *sk;
1362         int ret;
1363         struct net *net = dev_net(skb->dev);
1364
1365         if (skb->pkt_type != PACKET_HOST)
1366                 goto discard_it;
1367
1368         /*
1369          *      Count it even if it's bad.
1370          */
1371         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1372
1373         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1374                 goto discard_it;
1375
1376         th = tcp_hdr(skb);
1377
1378         if (th->doff < sizeof(struct tcphdr)/4)
1379                 goto bad_packet;
1380         if (!pskb_may_pull(skb, th->doff*4))
1381                 goto discard_it;
1382
1383         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1384                 goto csum_error;
1385
1386         th = tcp_hdr(skb);
1387         hdr = ipv6_hdr(skb);
1388
1389         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1390                                 inet6_iif(skb));
1391         if (!sk)
1392                 goto no_tcp_socket;
1393
1394 process:
1395         if (sk->sk_state == TCP_TIME_WAIT)
1396                 goto do_time_wait;
1397
1398         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1399                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1400                 goto discard_and_relse;
1401         }
1402
1403         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1404                 goto discard_and_relse;
1405
1406         tcp_v6_fill_cb(skb, hdr, th);
1407
1408 #ifdef CONFIG_TCP_MD5SIG
1409         if (tcp_v6_inbound_md5_hash(sk, skb))
1410                 goto discard_and_relse;
1411 #endif
1412
1413         if (sk_filter(sk, skb))
1414                 goto discard_and_relse;
1415
1416         sk_incoming_cpu_update(sk);
1417         skb->dev = NULL;
1418
1419         bh_lock_sock_nested(sk);
1420         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1421         ret = 0;
1422         if (!sock_owned_by_user(sk)) {
1423                 if (!tcp_prequeue(sk, skb))
1424                         ret = tcp_v6_do_rcv(sk, skb);
1425         } else if (unlikely(sk_add_backlog(sk, skb,
1426                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1427                 bh_unlock_sock(sk);
1428                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1429                 goto discard_and_relse;
1430         }
1431         bh_unlock_sock(sk);
1432
1433         sock_put(sk);
1434         return ret ? -1 : 0;
1435
1436 no_tcp_socket:
1437         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1438                 goto discard_it;
1439
1440         tcp_v6_fill_cb(skb, hdr, th);
1441
1442         if (tcp_checksum_complete(skb)) {
1443 csum_error:
1444                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1445 bad_packet:
1446                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1447         } else {
1448                 tcp_v6_send_reset(NULL, skb);
1449         }
1450
1451 discard_it:
1452         kfree_skb(skb);
1453         return 0;
1454
1455 discard_and_relse:
1456         sock_put(sk);
1457         goto discard_it;
1458
1459 do_time_wait:
1460         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1461                 inet_twsk_put(inet_twsk(sk));
1462                 goto discard_it;
1463         }
1464
1465         tcp_v6_fill_cb(skb, hdr, th);
1466
1467         if (tcp_checksum_complete(skb)) {
1468                 inet_twsk_put(inet_twsk(sk));
1469                 goto csum_error;
1470         }
1471
1472         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1473         case TCP_TW_SYN:
1474         {
1475                 struct sock *sk2;
1476
1477                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1478                                             &ipv6_hdr(skb)->saddr, th->source,
1479                                             &ipv6_hdr(skb)->daddr,
1480                                             ntohs(th->dest), tcp_v6_iif(skb));
1481                 if (sk2) {
1482                         struct inet_timewait_sock *tw = inet_twsk(sk);
1483                         inet_twsk_deschedule_put(tw);
1484                         sk = sk2;
1485                         tcp_v6_restore_cb(skb);
1486                         goto process;
1487                 }
1488                 /* Fall through to ACK */
1489         }
1490         case TCP_TW_ACK:
1491                 tcp_v6_timewait_ack(sk, skb);
1492                 break;
1493         case TCP_TW_RST:
1494                 tcp_v6_restore_cb(skb);
1495                 goto no_tcp_socket;
1496         case TCP_TW_SUCCESS:
1497                 ;
1498         }
1499         goto discard_it;
1500 }
1501
1502 static void tcp_v6_early_demux(struct sk_buff *skb)
1503 {
1504         const struct ipv6hdr *hdr;
1505         const struct tcphdr *th;
1506         struct sock *sk;
1507
1508         if (skb->pkt_type != PACKET_HOST)
1509                 return;
1510
1511         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1512                 return;
1513
1514         hdr = ipv6_hdr(skb);
1515         th = tcp_hdr(skb);
1516
1517         if (th->doff < sizeof(struct tcphdr) / 4)
1518                 return;
1519
1520         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1521         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1522                                         &hdr->saddr, th->source,
1523                                         &hdr->daddr, ntohs(th->dest),
1524                                         inet6_iif(skb));
1525         if (sk) {
1526                 skb->sk = sk;
1527                 skb->destructor = sock_edemux;
1528                 if (sk_fullsock(sk)) {
1529                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1530
1531                         if (dst)
1532                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1533                         if (dst &&
1534                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1535                                 skb_dst_set_noref(skb, dst);
1536                 }
1537         }
1538 }
1539
1540 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1541         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1542         .twsk_unique    = tcp_twsk_unique,
1543         .twsk_destructor = tcp_twsk_destructor,
1544 };
1545
1546 static const struct inet_connection_sock_af_ops ipv6_specific = {
1547         .queue_xmit        = inet6_csk_xmit,
1548         .send_check        = tcp_v6_send_check,
1549         .rebuild_header    = inet6_sk_rebuild_header,
1550         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1551         .conn_request      = tcp_v6_conn_request,
1552         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1553         .net_header_len    = sizeof(struct ipv6hdr),
1554         .net_frag_header_len = sizeof(struct frag_hdr),
1555         .setsockopt        = ipv6_setsockopt,
1556         .getsockopt        = ipv6_getsockopt,
1557         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1558         .sockaddr_len      = sizeof(struct sockaddr_in6),
1559         .bind_conflict     = inet6_csk_bind_conflict,
1560 #ifdef CONFIG_COMPAT
1561         .compat_setsockopt = compat_ipv6_setsockopt,
1562         .compat_getsockopt = compat_ipv6_getsockopt,
1563 #endif
1564         .mtu_reduced       = tcp_v6_mtu_reduced,
1565 };
1566
1567 #ifdef CONFIG_TCP_MD5SIG
1568 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1569         .md5_lookup     =       tcp_v6_md5_lookup,
1570         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1571         .md5_parse      =       tcp_v6_parse_md5_keys,
1572 };
1573 #endif
1574
1575 /*
1576  *      TCP over IPv4 via INET6 API
1577  */
1578 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1579         .queue_xmit        = ip_queue_xmit,
1580         .send_check        = tcp_v4_send_check,
1581         .rebuild_header    = inet_sk_rebuild_header,
1582         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1583         .conn_request      = tcp_v6_conn_request,
1584         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1585         .net_header_len    = sizeof(struct iphdr),
1586         .setsockopt        = ipv6_setsockopt,
1587         .getsockopt        = ipv6_getsockopt,
1588         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1589         .sockaddr_len      = sizeof(struct sockaddr_in6),
1590         .bind_conflict     = inet6_csk_bind_conflict,
1591 #ifdef CONFIG_COMPAT
1592         .compat_setsockopt = compat_ipv6_setsockopt,
1593         .compat_getsockopt = compat_ipv6_getsockopt,
1594 #endif
1595         .mtu_reduced       = tcp_v4_mtu_reduced,
1596 };
1597
1598 #ifdef CONFIG_TCP_MD5SIG
1599 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1600         .md5_lookup     =       tcp_v4_md5_lookup,
1601         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1602         .md5_parse      =       tcp_v6_parse_md5_keys,
1603 };
1604 #endif
1605
1606 /* NOTE: A lot of things set to zero explicitly by call to
1607  *       sk_alloc() so need not be done here.
1608  */
1609 static int tcp_v6_init_sock(struct sock *sk)
1610 {
1611         struct inet_connection_sock *icsk = inet_csk(sk);
1612
1613         tcp_init_sock(sk);
1614
1615         icsk->icsk_af_ops = &ipv6_specific;
1616
1617 #ifdef CONFIG_TCP_MD5SIG
1618         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1619 #endif
1620
1621         return 0;
1622 }
1623
1624 static void tcp_v6_destroy_sock(struct sock *sk)
1625 {
1626         tcp_v4_destroy_sock(sk);
1627         inet6_destroy_sock(sk);
1628 }
1629
1630 #ifdef CONFIG_PROC_FS
1631 /* Proc filesystem TCPv6 sock list dumping. */
1632 static void get_openreq6(struct seq_file *seq,
1633                          struct request_sock *req, int i, kuid_t uid)
1634 {
1635         long ttd = req->rsk_timer.expires - jiffies;
1636         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1637         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1638
1639         if (ttd < 0)
1640                 ttd = 0;
1641
1642         seq_printf(seq,
1643                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1644                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1645                    i,
1646                    src->s6_addr32[0], src->s6_addr32[1],
1647                    src->s6_addr32[2], src->s6_addr32[3],
1648                    inet_rsk(req)->ir_num,
1649                    dest->s6_addr32[0], dest->s6_addr32[1],
1650                    dest->s6_addr32[2], dest->s6_addr32[3],
1651                    ntohs(inet_rsk(req)->ir_rmt_port),
1652                    TCP_SYN_RECV,
1653                    0, 0, /* could print option size, but that is af dependent. */
1654                    1,   /* timers active (only the expire timer) */
1655                    jiffies_to_clock_t(ttd),
1656                    req->num_timeout,
1657                    from_kuid_munged(seq_user_ns(seq), uid),
1658                    0,  /* non standard timer */
1659                    0, /* open_requests have no inode */
1660                    0, req);
1661 }
1662
1663 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1664 {
1665         const struct in6_addr *dest, *src;
1666         __u16 destp, srcp;
1667         int timer_active;
1668         unsigned long timer_expires;
1669         const struct inet_sock *inet = inet_sk(sp);
1670         const struct tcp_sock *tp = tcp_sk(sp);
1671         const struct inet_connection_sock *icsk = inet_csk(sp);
1672         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1673
1674         dest  = &sp->sk_v6_daddr;
1675         src   = &sp->sk_v6_rcv_saddr;
1676         destp = ntohs(inet->inet_dport);
1677         srcp  = ntohs(inet->inet_sport);
1678
1679         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1680                 timer_active    = 1;
1681                 timer_expires   = icsk->icsk_timeout;
1682         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1683                 timer_active    = 4;
1684                 timer_expires   = icsk->icsk_timeout;
1685         } else if (timer_pending(&sp->sk_timer)) {
1686                 timer_active    = 2;
1687                 timer_expires   = sp->sk_timer.expires;
1688         } else {
1689                 timer_active    = 0;
1690                 timer_expires = jiffies;
1691         }
1692
1693         seq_printf(seq,
1694                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1695                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1696                    i,
1697                    src->s6_addr32[0], src->s6_addr32[1],
1698                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1699                    dest->s6_addr32[0], dest->s6_addr32[1],
1700                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1701                    sp->sk_state,
1702                    tp->write_seq-tp->snd_una,
1703                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1704                    timer_active,
1705                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1706                    icsk->icsk_retransmits,
1707                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1708                    icsk->icsk_probes_out,
1709                    sock_i_ino(sp),
1710                    atomic_read(&sp->sk_refcnt), sp,
1711                    jiffies_to_clock_t(icsk->icsk_rto),
1712                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1713                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1714                    tp->snd_cwnd,
1715                    sp->sk_state == TCP_LISTEN ?
1716                         (fastopenq ? fastopenq->max_qlen : 0) :
1717                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1718                    );
1719 }
1720
1721 static void get_timewait6_sock(struct seq_file *seq,
1722                                struct inet_timewait_sock *tw, int i)
1723 {
1724         long delta = tw->tw_timer.expires - jiffies;
1725         const struct in6_addr *dest, *src;
1726         __u16 destp, srcp;
1727
1728         dest = &tw->tw_v6_daddr;
1729         src  = &tw->tw_v6_rcv_saddr;
1730         destp = ntohs(tw->tw_dport);
1731         srcp  = ntohs(tw->tw_sport);
1732
1733         seq_printf(seq,
1734                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1735                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1736                    i,
1737                    src->s6_addr32[0], src->s6_addr32[1],
1738                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1739                    dest->s6_addr32[0], dest->s6_addr32[1],
1740                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1741                    tw->tw_substate, 0, 0,
1742                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1743                    atomic_read(&tw->tw_refcnt), tw);
1744 }
1745
1746 static int tcp6_seq_show(struct seq_file *seq, void *v)
1747 {
1748         struct tcp_iter_state *st;
1749         struct sock *sk = v;
1750
1751         if (v == SEQ_START_TOKEN) {
1752                 seq_puts(seq,
1753                          "  sl  "
1754                          "local_address                         "
1755                          "remote_address                        "
1756                          "st tx_queue rx_queue tr tm->when retrnsmt"
1757                          "   uid  timeout inode\n");
1758                 goto out;
1759         }
1760         st = seq->private;
1761
1762         switch (st->state) {
1763         case TCP_SEQ_STATE_LISTENING:
1764         case TCP_SEQ_STATE_ESTABLISHED:
1765                 if (sk->sk_state == TCP_TIME_WAIT)
1766                         get_timewait6_sock(seq, v, st->num);
1767                 else
1768                         get_tcp6_sock(seq, v, st->num);
1769                 break;
1770         case TCP_SEQ_STATE_OPENREQ:
1771                 get_openreq6(seq, v, st->num, st->uid);
1772                 break;
1773         }
1774 out:
1775         return 0;
1776 }
1777
1778 static const struct file_operations tcp6_afinfo_seq_fops = {
1779         .owner   = THIS_MODULE,
1780         .open    = tcp_seq_open,
1781         .read    = seq_read,
1782         .llseek  = seq_lseek,
1783         .release = seq_release_net
1784 };
1785
1786 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1787         .name           = "tcp6",
1788         .family         = AF_INET6,
1789         .seq_fops       = &tcp6_afinfo_seq_fops,
1790         .seq_ops        = {
1791                 .show           = tcp6_seq_show,
1792         },
1793 };
1794
1795 int __net_init tcp6_proc_init(struct net *net)
1796 {
1797         return tcp_proc_register(net, &tcp6_seq_afinfo);
1798 }
1799
1800 void tcp6_proc_exit(struct net *net)
1801 {
1802         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1803 }
1804 #endif
1805
1806 static void tcp_v6_clear_sk(struct sock *sk, int size)
1807 {
1808         struct inet_sock *inet = inet_sk(sk);
1809
1810         /* we do not want to clear pinet6 field, because of RCU lookups */
1811         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1812
1813         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1814         memset(&inet->pinet6 + 1, 0, size);
1815 }
1816
1817 struct proto tcpv6_prot = {
1818         .name                   = "TCPv6",
1819         .owner                  = THIS_MODULE,
1820         .close                  = tcp_close,
1821         .connect                = tcp_v6_connect,
1822         .disconnect             = tcp_disconnect,
1823         .accept                 = inet_csk_accept,
1824         .ioctl                  = tcp_ioctl,
1825         .init                   = tcp_v6_init_sock,
1826         .destroy                = tcp_v6_destroy_sock,
1827         .shutdown               = tcp_shutdown,
1828         .setsockopt             = tcp_setsockopt,
1829         .getsockopt             = tcp_getsockopt,
1830         .recvmsg                = tcp_recvmsg,
1831         .sendmsg                = tcp_sendmsg,
1832         .sendpage               = tcp_sendpage,
1833         .backlog_rcv            = tcp_v6_do_rcv,
1834         .release_cb             = tcp_release_cb,
1835         .hash                   = inet_hash,
1836         .unhash                 = inet_unhash,
1837         .get_port               = inet_csk_get_port,
1838         .enter_memory_pressure  = tcp_enter_memory_pressure,
1839         .stream_memory_free     = tcp_stream_memory_free,
1840         .sockets_allocated      = &tcp_sockets_allocated,
1841         .memory_allocated       = &tcp_memory_allocated,
1842         .memory_pressure        = &tcp_memory_pressure,
1843         .orphan_count           = &tcp_orphan_count,
1844         .sysctl_mem             = sysctl_tcp_mem,
1845         .sysctl_wmem            = sysctl_tcp_wmem,
1846         .sysctl_rmem            = sysctl_tcp_rmem,
1847         .max_header             = MAX_TCP_HEADER,
1848         .obj_size               = sizeof(struct tcp6_sock),
1849         .slab_flags             = SLAB_DESTROY_BY_RCU,
1850         .twsk_prot              = &tcp6_timewait_sock_ops,
1851         .rsk_prot               = &tcp6_request_sock_ops,
1852         .h.hashinfo             = &tcp_hashinfo,
1853         .no_autobind            = true,
1854 #ifdef CONFIG_COMPAT
1855         .compat_setsockopt      = compat_tcp_setsockopt,
1856         .compat_getsockopt      = compat_tcp_getsockopt,
1857 #endif
1858 #ifdef CONFIG_MEMCG_KMEM
1859         .proto_cgroup           = tcp_proto_cgroup,
1860 #endif
1861         .clear_sk               = tcp_v6_clear_sk,
1862 };
1863
1864 static const struct inet6_protocol tcpv6_protocol = {
1865         .early_demux    =       tcp_v6_early_demux,
1866         .handler        =       tcp_v6_rcv,
1867         .err_handler    =       tcp_v6_err,
1868         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1869 };
1870
1871 static struct inet_protosw tcpv6_protosw = {
1872         .type           =       SOCK_STREAM,
1873         .protocol       =       IPPROTO_TCP,
1874         .prot           =       &tcpv6_prot,
1875         .ops            =       &inet6_stream_ops,
1876         .flags          =       INET_PROTOSW_PERMANENT |
1877                                 INET_PROTOSW_ICSK,
1878 };
1879
1880 static int __net_init tcpv6_net_init(struct net *net)
1881 {
1882         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1883                                     SOCK_RAW, IPPROTO_TCP, net);
1884 }
1885
1886 static void __net_exit tcpv6_net_exit(struct net *net)
1887 {
1888         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1889 }
1890
1891 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1892 {
1893         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1894 }
1895
1896 static struct pernet_operations tcpv6_net_ops = {
1897         .init       = tcpv6_net_init,
1898         .exit       = tcpv6_net_exit,
1899         .exit_batch = tcpv6_net_exit_batch,
1900 };
1901
1902 int __init tcpv6_init(void)
1903 {
1904         int ret;
1905
1906         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1907         if (ret)
1908                 goto out;
1909
1910         /* register inet6 protocol */
1911         ret = inet6_register_protosw(&tcpv6_protosw);
1912         if (ret)
1913                 goto out_tcpv6_protocol;
1914
1915         ret = register_pernet_subsys(&tcpv6_net_ops);
1916         if (ret)
1917                 goto out_tcpv6_protosw;
1918 out:
1919         return ret;
1920
1921 out_tcpv6_protosw:
1922         inet6_unregister_protosw(&tcpv6_protosw);
1923 out_tcpv6_protocol:
1924         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1925         goto out;
1926 }
1927
1928 void tcpv6_exit(void)
1929 {
1930         unregister_pernet_subsys(&tcpv6_net_ops);
1931         inet6_unregister_protosw(&tcpv6_protosw);
1932         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1933 }