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 <crypto/hash.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, lockdep_sock_is_held(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         bool fatal;
 331         int err;
 332
 333         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 334                                         &hdr->daddr, th->dest,
 335                                         &hdr->saddr, ntohs(th->source),
 336                                         skb->dev->ifindex);
 337
 338         if (!sk) {
 339                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 340                                   ICMP6_MIB_INERRORS);
 341                 return;
 342         }
 343
 344         if (sk->sk_state == TCP_TIME_WAIT) {
 345                 inet_twsk_put(inet_twsk(sk));
 346                 return;
 347         }
 348         seq = ntohl(th->seq);
 349         fatal = icmpv6_err_convert(type, code, &err);
 350         if (sk->sk_state == TCP_NEW_SYN_RECV)
 351                 return tcp_req_err(sk, seq, fatal);
 352
 353         bh_lock_sock(sk);
 354         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 355                 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
 356
 357         if (sk->sk_state == TCP_CLOSE)
 358                 goto out;
 359
 360         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 361                 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
 362                 goto out;
 363         }
 364
 365         tp = tcp_sk(sk);
 366         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 367         fastopen = tp->fastopen_rsk;
 368         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 369         if (sk->sk_state != TCP_LISTEN &&
 370             !between(seq, snd_una, tp->snd_nxt)) {
 371                 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
 372                 goto out;
 373         }
 374
 375         np = inet6_sk(sk);
 376
 377         if (type == NDISC_REDIRECT) {
 378                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 379
 380                 if (dst)
 381                         dst->ops->redirect(dst, sk, skb);
 382                 goto out;
 383         }
 384
 385         if (type == ICMPV6_PKT_TOOBIG) {
 386                 /* We are not interested in TCP_LISTEN and open_requests
 387                  * (SYN-ACKs send out by Linux are always <576bytes so
 388                  * they should go through unfragmented).
 389                  */
 390                 if (sk->sk_state == TCP_LISTEN)
 391                         goto out;
 392
 393                 if (!ip6_sk_accept_pmtu(sk))
 394                         goto out;
 395
 396                 tp->mtu_info = ntohl(info);
 397                 if (!sock_owned_by_user(sk))
 398                         tcp_v6_mtu_reduced(sk);
 399                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 400                                            &tp->tsq_flags))
 401                         sock_hold(sk);
 402                 goto out;
 403         }
 404
 405
 406         /* Might be for an request_sock */
 407         switch (sk->sk_state) {
 408         case TCP_SYN_SENT:
 409         case TCP_SYN_RECV:
 410                 /* Only in fast or simultaneous open. If a fast open socket is
 411                  * is already accepted it is treated as a connected one below.
 412                  */
 413                 if (fastopen && !fastopen->sk)
 414                         break;
 415
 416                 if (!sock_owned_by_user(sk)) {
 417                         sk->sk_err = err;
 418                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 419
 420                         tcp_done(sk);
 421                 } else
 422                         sk->sk_err_soft = err;
 423                 goto out;
 424         }
 425
 426         if (!sock_owned_by_user(sk) && np->recverr) {
 427                 sk->sk_err = err;
 428                 sk->sk_error_report(sk);
 429         } else
 430                 sk->sk_err_soft = err;
 431
 432 out:
 433         bh_unlock_sock(sk);
 434         sock_put(sk);
 435 }
 436
 437
 438 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 439                               struct flowi *fl,
 440                               struct request_sock *req,
 441                               struct tcp_fastopen_cookie *foc,
 442                               enum tcp_synack_type synack_type)
 443 {
 444         struct inet_request_sock *ireq = inet_rsk(req);
 445         struct ipv6_pinfo *np = inet6_sk(sk);
 446         struct ipv6_txoptions *opt;
 447         struct flowi6 *fl6 = &fl->u.ip6;
 448         struct sk_buff *skb;
 449         int err = -ENOMEM;
 450
 451         /* First, grab a route. */
 452         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
 453                                                IPPROTO_TCP)) == NULL)
 454                 goto done;
 455
 456         skb = tcp_make_synack(sk, dst, req, foc, synack_type);
 457
 458         if (skb) {
 459                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 460                                     &ireq->ir_v6_rmt_addr);
 461
 462                 fl6->daddr = ireq->ir_v6_rmt_addr;
 463                 if (np->repflow && ireq->pktopts)
 464                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 465
 466                 rcu_read_lock();
 467                 opt = ireq->ipv6_opt;
 468                 if (!opt)
 469                         opt = rcu_dereference(np->opt);
 470                 err = ip6_xmit(sk, skb, fl6, opt, np->tclass);
 471                 rcu_read_unlock();
 472                 err = net_xmit_eval(err);
 473         }
 474
 475 done:
 476         return err;
 477 }
 478
 479
 480 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 481 {
 482         kfree(inet_rsk(req)->ipv6_opt);
 483         kfree_skb(inet_rsk(req)->pktopts);
 484 }
 485
 486 #ifdef CONFIG_TCP_MD5SIG
 487 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 488                                                    const struct in6_addr *addr)
 489 {
 490         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 491 }
 492
 493 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 494                                                 const struct sock *addr_sk)
 495 {
 496         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 497 }
 498
 499 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 500                                  int optlen)
 501 {
 502         struct tcp_md5sig cmd;
 503         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 504
 505         if (optlen < sizeof(cmd))
 506                 return -EINVAL;
 507
 508         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 509                 return -EFAULT;
 510
 511         if (sin6->sin6_family != AF_INET6)
 512                 return -EINVAL;
 513
 514         if (!cmd.tcpm_keylen) {
 515                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 516                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 517                                               AF_INET);
 518                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 519                                       AF_INET6);
 520         }
 521
 522         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 523                 return -EINVAL;
 524
 525         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 526                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 527                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 528
 529         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 530                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 531 }
 532
 533 static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
 534                                    const struct in6_addr *daddr,
 535                                    const struct in6_addr *saddr,
 536                                    const struct tcphdr *th, int nbytes)
 537 {
 538         struct tcp6_pseudohdr *bp;
 539         struct scatterlist sg;
 540         struct tcphdr *_th;
 541
 542         bp = hp->scratch;
 543         /* 1. TCP pseudo-header (RFC2460) */
 544         bp->saddr = *saddr;
 545         bp->daddr = *daddr;
 546         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 547         bp->len = cpu_to_be32(nbytes);
 548
 549         _th = (struct tcphdr *)(bp + 1);
 550         memcpy(_th, th, sizeof(*th));
 551         _th->check = 0;
 552
 553         sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
 554         ahash_request_set_crypt(hp->md5_req, &sg, NULL,
 555                                 sizeof(*bp) + sizeof(*th));
 556         return crypto_ahash_update(hp->md5_req);
 557 }
 558
 559 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 560                                const struct in6_addr *daddr, struct in6_addr *saddr,
 561                                const struct tcphdr *th)
 562 {
 563         struct tcp_md5sig_pool *hp;
 564         struct ahash_request *req;
 565
 566         hp = tcp_get_md5sig_pool();
 567         if (!hp)
 568                 goto clear_hash_noput;
 569         req = hp->md5_req;
 570
 571         if (crypto_ahash_init(req))
 572                 goto clear_hash;
 573         if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
 574                 goto clear_hash;
 575         if (tcp_md5_hash_key(hp, key))
 576                 goto clear_hash;
 577         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 578         if (crypto_ahash_final(req))
 579                 goto clear_hash;
 580
 581         tcp_put_md5sig_pool();
 582         return 0;
 583
 584 clear_hash:
 585         tcp_put_md5sig_pool();
 586 clear_hash_noput:
 587         memset(md5_hash, 0, 16);
 588         return 1;
 589 }
 590
 591 static int tcp_v6_md5_hash_skb(char *md5_hash,
 592                                const struct tcp_md5sig_key *key,
 593                                const struct sock *sk,
 594                                const struct sk_buff *skb)
 595 {
 596         const struct in6_addr *saddr, *daddr;
 597         struct tcp_md5sig_pool *hp;
 598         struct ahash_request *req;
 599         const struct tcphdr *th = tcp_hdr(skb);
 600
 601         if (sk) { /* valid for establish/request sockets */
 602                 saddr = &sk->sk_v6_rcv_saddr;
 603                 daddr = &sk->sk_v6_daddr;
 604         } else {
 605                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 606                 saddr = &ip6h->saddr;
 607                 daddr = &ip6h->daddr;
 608         }
 609
 610         hp = tcp_get_md5sig_pool();
 611         if (!hp)
 612                 goto clear_hash_noput;
 613         req = hp->md5_req;
 614
 615         if (crypto_ahash_init(req))
 616                 goto clear_hash;
 617
 618         if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
 619                 goto clear_hash;
 620         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 621                 goto clear_hash;
 622         if (tcp_md5_hash_key(hp, key))
 623                 goto clear_hash;
 624         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 625         if (crypto_ahash_final(req))
 626                 goto clear_hash;
 627
 628         tcp_put_md5sig_pool();
 629         return 0;
 630
 631 clear_hash:
 632         tcp_put_md5sig_pool();
 633 clear_hash_noput:
 634         memset(md5_hash, 0, 16);
 635         return 1;
 636 }
 637
 638 #endif
 639
 640 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 641                                     const struct sk_buff *skb)
 642 {
 643 #ifdef CONFIG_TCP_MD5SIG
 644         const __u8 *hash_location = NULL;
 645         struct tcp_md5sig_key *hash_expected;
 646         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 647         const struct tcphdr *th = tcp_hdr(skb);
 648         int genhash;
 649         u8 newhash[16];
 650
 651         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 652         hash_location = tcp_parse_md5sig_option(th);
 653
 654         /* We've parsed the options - do we have a hash? */
 655         if (!hash_expected && !hash_location)
 656                 return false;
 657
 658         if (hash_expected && !hash_location) {
 659                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 660                 return true;
 661         }
 662
 663         if (!hash_expected && hash_location) {
 664                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 665                 return true;
 666         }
 667
 668         /* check the signature */
 669         genhash = tcp_v6_md5_hash_skb(newhash,
 670                                       hash_expected,
 671                                       NULL, skb);
 672
 673         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 674                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
 675                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 676                                      genhash ? "failed" : "mismatch",
 677                                      &ip6h->saddr, ntohs(th->source),
 678                                      &ip6h->daddr, ntohs(th->dest));
 679                 return true;
 680         }
 681 #endif
 682         return false;
 683 }
 684
 685 static void tcp_v6_init_req(struct request_sock *req,
 686                             const struct sock *sk_listener,
 687                             struct sk_buff *skb)
 688 {
 689         struct inet_request_sock *ireq = inet_rsk(req);
 690         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 691
 692         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 693         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 694
 695         /* So that link locals have meaning */
 696         if (!sk_listener->sk_bound_dev_if &&
 697             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 698                 ireq->ir_iif = tcp_v6_iif(skb);
 699
 700         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 701             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 702              np->rxopt.bits.rxinfo ||
 703              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 704              np->rxopt.bits.rxohlim || np->repflow)) {
 705                 atomic_inc(&skb->users);
 706                 ireq->pktopts = skb;
 707         }
 708 }
 709
 710 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 711                                           struct flowi *fl,
 712                                           const struct request_sock *req,
 713                                           bool *strict)
 714 {
 715         if (strict)
 716                 *strict = true;
 717         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 718 }
 719
 720 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 721         .family         =       AF_INET6,
 722         .obj_size       =       sizeof(struct tcp6_request_sock),
 723         .rtx_syn_ack    =       tcp_rtx_synack,
 724         .send_ack       =       tcp_v6_reqsk_send_ack,
 725         .destructor     =       tcp_v6_reqsk_destructor,
 726         .send_reset     =       tcp_v6_send_reset,
 727         .syn_ack_timeout =      tcp_syn_ack_timeout,
 728 };
 729
 730 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 731         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 732                                 sizeof(struct ipv6hdr),
 733 #ifdef CONFIG_TCP_MD5SIG
 734         .req_md5_lookup =       tcp_v6_md5_lookup,
 735         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 736 #endif
 737         .init_req       =       tcp_v6_init_req,
 738 #ifdef CONFIG_SYN_COOKIES
 739         .cookie_init_seq =      cookie_v6_init_sequence,
 740 #endif
 741         .route_req      =       tcp_v6_route_req,
 742         .init_seq       =       tcp_v6_init_sequence,
 743         .send_synack    =       tcp_v6_send_synack,
 744 };
 745
 746 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 747                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 748                                  int oif, struct tcp_md5sig_key *key, int rst,
 749                                  u8 tclass, __be32 label)
 750 {
 751         const struct tcphdr *th = tcp_hdr(skb);
 752         struct tcphdr *t1;
 753         struct sk_buff *buff;
 754         struct flowi6 fl6;
 755         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 756         struct sock *ctl_sk = net->ipv6.tcp_sk;
 757         unsigned int tot_len = sizeof(struct tcphdr);
 758         struct dst_entry *dst;
 759         __be32 *topt;
 760
 761         if (tsecr)
 762                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 763 #ifdef CONFIG_TCP_MD5SIG
 764         if (key)
 765                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 766 #endif
 767
 768         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 769                          GFP_ATOMIC);
 770         if (!buff)
 771                 return;
 772
 773         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 774
 775         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 776         skb_reset_transport_header(buff);
 777
 778         /* Swap the send and the receive. */
 779         memset(t1, 0, sizeof(*t1));
 780         t1->dest = th->source;
 781         t1->source = th->dest;
 782         t1->doff = tot_len / 4;
 783         t1->seq = htonl(seq);
 784         t1->ack_seq = htonl(ack);
 785         t1->ack = !rst || !th->ack;
 786         t1->rst = rst;
 787         t1->window = htons(win);
 788
 789         topt = (__be32 *)(t1 + 1);
 790
 791         if (tsecr) {
 792                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 793                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 794                 *topt++ = htonl(tsval);
 795                 *topt++ = htonl(tsecr);
 796         }
 797
 798 #ifdef CONFIG_TCP_MD5SIG
 799         if (key) {
 800                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 801                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 802                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 803                                     &ipv6_hdr(skb)->saddr,
 804                                     &ipv6_hdr(skb)->daddr, t1);
 805         }
 806 #endif
 807
 808         memset(&fl6, 0, sizeof(fl6));
 809         fl6.daddr = ipv6_hdr(skb)->saddr;
 810         fl6.saddr = ipv6_hdr(skb)->daddr;
 811         fl6.flowlabel = label;
 812
 813         buff->ip_summed = CHECKSUM_PARTIAL;
 814         buff->csum = 0;
 815
 816         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 817
 818         fl6.flowi6_proto = IPPROTO_TCP;
 819         if (rt6_need_strict(&fl6.daddr) && !oif)
 820                 fl6.flowi6_oif = tcp_v6_iif(skb);
 821         else {
 822                 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
 823                         oif = skb->skb_iif;
 824
 825                 fl6.flowi6_oif = oif;
 826         }
 827
 828         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 829         fl6.fl6_dport = t1->dest;
 830         fl6.fl6_sport = t1->source;
 831         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 832
 833         /* Pass a socket to ip6_dst_lookup either it is for RST
 834          * Underlying function will use this to retrieve the network
 835          * namespace
 836          */
 837         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 838         if (!IS_ERR(dst)) {
 839                 skb_dst_set(buff, dst);
 840                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 841                 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 842                 if (rst)
 843                         TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
 844                 return;
 845         }
 846
 847         kfree_skb(buff);
 848 }
 849
 850 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 851 {
 852         const struct tcphdr *th = tcp_hdr(skb);
 853         u32 seq = 0, ack_seq = 0;
 854         struct tcp_md5sig_key *key = NULL;
 855 #ifdef CONFIG_TCP_MD5SIG
 856         const __u8 *hash_location = NULL;
 857         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 858         unsigned char newhash[16];
 859         int genhash;
 860         struct sock *sk1 = NULL;
 861 #endif
 862         int oif;
 863
 864         if (th->rst)
 865                 return;
 866
 867         /* If sk not NULL, it means we did a successful lookup and incoming
 868          * route had to be correct. prequeue might have dropped our dst.
 869          */
 870         if (!sk && !ipv6_unicast_destination(skb))
 871                 return;
 872
 873 #ifdef CONFIG_TCP_MD5SIG
 874         rcu_read_lock();
 875         hash_location = tcp_parse_md5sig_option(th);
 876         if (sk && sk_fullsock(sk)) {
 877                 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
 878         } else if (hash_location) {
 879                 /*
 880                  * active side is lost. Try to find listening socket through
 881                  * source port, and then find md5 key through listening socket.
 882                  * we are not loose security here:
 883                  * Incoming packet is checked with md5 hash with finding key,
 884                  * no RST generated if md5 hash doesn't match.
 885                  */
 886                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 887                                            &tcp_hashinfo, NULL, 0,
 888                                            &ipv6h->saddr,
 889                                            th->source, &ipv6h->daddr,
 890                                            ntohs(th->source), tcp_v6_iif(skb));
 891                 if (!sk1)
 892                         goto out;
 893
 894                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 895                 if (!key)
 896                         goto out;
 897
 898                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 899                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 900                         goto out;
 901         }
 902 #endif
 903
 904         if (th->ack)
 905                 seq = ntohl(th->ack_seq);
 906         else
 907                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 908                           (th->doff << 2);
 909
 910         oif = sk ? sk->sk_bound_dev_if : 0;
 911         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 912
 913 #ifdef CONFIG_TCP_MD5SIG
 914 out:
 915         rcu_read_unlock();
 916 #endif
 917 }
 918
 919 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 920                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 921                             struct tcp_md5sig_key *key, u8 tclass,
 922                             __be32 label)
 923 {
 924         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 925                              tclass, label);
 926 }
 927
 928 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 929 {
 930         struct inet_timewait_sock *tw = inet_twsk(sk);
 931         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 932
 933         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 934                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 935                         tcp_time_stamp + tcptw->tw_ts_offset,
 936                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 937                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 938
 939         inet_twsk_put(tw);
 940 }
 941
 942 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 943                                   struct request_sock *req)
 944 {
 945         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 946          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 947          */
 948         /* RFC 7323 2.3
 949          * The window field (SEG.WND) of every outgoing segment, with the
 950          * exception of <SYN> segments, MUST be right-shifted by
 951          * Rcv.Wind.Shift bits:
 952          */
 953         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 954                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 955                         tcp_rsk(req)->rcv_nxt,
 956                         req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
 957                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 958                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 959                         0, 0);
 960 }
 961
 962
 963 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
 964 {
 965 #ifdef CONFIG_SYN_COOKIES
 966         const struct tcphdr *th = tcp_hdr(skb);
 967
 968         if (!th->syn)
 969                 sk = cookie_v6_check(sk, skb);
 970 #endif
 971         return sk;
 972 }
 973
 974 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 975 {
 976         if (skb->protocol == htons(ETH_P_IP))
 977                 return tcp_v4_conn_request(sk, skb);
 978
 979         if (!ipv6_unicast_destination(skb))
 980                 goto drop;
 981
 982         return tcp_conn_request(&tcp6_request_sock_ops,
 983                                 &tcp_request_sock_ipv6_ops, sk, skb);
 984
 985 drop:
 986         tcp_listendrop(sk);
 987         return 0; /* don't send reset */
 988 }
 989
 990 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 991                                          struct request_sock *req,
 992                                          struct dst_entry *dst,
 993                                          struct request_sock *req_unhash,
 994                                          bool *own_req)
 995 {
 996         struct inet_request_sock *ireq;
 997         struct ipv6_pinfo *newnp;
 998         const struct ipv6_pinfo *np = inet6_sk(sk);
 999         struct ipv6_txoptions *opt;
1000         struct tcp6_sock *newtcp6sk;
1001         struct inet_sock *newinet;
1002         struct tcp_sock *newtp;
1003         struct sock *newsk;
1004 #ifdef CONFIG_TCP_MD5SIG
1005         struct tcp_md5sig_key *key;
1006 #endif
1007         struct flowi6 fl6;
1008
1009         if (skb->protocol == htons(ETH_P_IP)) {
1010                 /*
1011                  *      v6 mapped
1012                  */
1013
1014                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1015                                              req_unhash, own_req);
1016
1017                 if (!newsk)
1018                         return NULL;
1019
1020                 newtcp6sk = (struct tcp6_sock *)newsk;
1021                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1022
1023                 newinet = inet_sk(newsk);
1024                 newnp = inet6_sk(newsk);
1025                 newtp = tcp_sk(newsk);
1026
1027                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1028
1029                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1030
1031                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1032                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1033 #ifdef CONFIG_TCP_MD5SIG
1034                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1035 #endif
1036
1037                 newnp->ipv6_ac_list = NULL;
1038                 newnp->ipv6_fl_list = NULL;
1039                 newnp->pktoptions  = NULL;
1040                 newnp->opt         = NULL;
1041                 newnp->mcast_oif   = tcp_v6_iif(skb);
1042                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1043                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1044                 if (np->repflow)
1045                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1046
1047                 /*
1048                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1049                  * here, tcp_create_openreq_child now does this for us, see the comment in
1050                  * that function for the gory details. -acme
1051                  */
1052
1053                 /* It is tricky place. Until this moment IPv4 tcp
1054                    worked with IPv6 icsk.icsk_af_ops.
1055                    Sync it now.
1056                  */
1057                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1058
1059                 return newsk;
1060         }
1061
1062         ireq = inet_rsk(req);
1063
1064         if (sk_acceptq_is_full(sk))
1065                 goto out_overflow;
1066
1067         if (!dst) {
1068                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1069                 if (!dst)
1070                         goto out;
1071         }
1072
1073         newsk = tcp_create_openreq_child(sk, req, skb);
1074         if (!newsk)
1075                 goto out_nonewsk;
1076
1077         /*
1078          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1079          * count here, tcp_create_openreq_child now does this for us, see the
1080          * comment in that function for the gory details. -acme
1081          */
1082
1083         newsk->sk_gso_type = SKB_GSO_TCPV6;
1084         ip6_dst_store(newsk, dst, NULL, NULL);
1085         inet6_sk_rx_dst_set(newsk, skb);
1086
1087         newtcp6sk = (struct tcp6_sock *)newsk;
1088         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1089
1090         newtp = tcp_sk(newsk);
1091         newinet = inet_sk(newsk);
1092         newnp = inet6_sk(newsk);
1093
1094         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1095
1096         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1097         newnp->saddr = ireq->ir_v6_loc_addr;
1098         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1099         newsk->sk_bound_dev_if = ireq->ir_iif;
1100
1101         /* Now IPv6 options...
1102
1103            First: no IPv4 options.
1104          */
1105         newinet->inet_opt = NULL;
1106         newnp->ipv6_ac_list = NULL;
1107         newnp->ipv6_fl_list = NULL;
1108
1109         /* Clone RX bits */
1110         newnp->rxopt.all = np->rxopt.all;
1111
1112         newnp->pktoptions = NULL;
1113         newnp->opt        = NULL;
1114         newnp->mcast_oif  = tcp_v6_iif(skb);
1115         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1116         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1117         if (np->repflow)
1118                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1119
1120         /* Clone native IPv6 options from listening socket (if any)
1121
1122            Yes, keeping reference count would be much more clever,
1123            but we make one more one thing there: reattach optmem
1124            to newsk.
1125          */
1126         opt = ireq->ipv6_opt;
1127         if (!opt)
1128                 opt = rcu_dereference(np->opt);
1129         if (opt) {
1130                 opt = ipv6_dup_options(newsk, opt);
1131                 RCU_INIT_POINTER(newnp->opt, opt);
1132         }
1133         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1134         if (opt)
1135                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1136                                                     opt->opt_flen;
1137
1138         tcp_ca_openreq_child(newsk, dst);
1139
1140         tcp_sync_mss(newsk, dst_mtu(dst));
1141         newtp->advmss = dst_metric_advmss(dst);
1142         if (tcp_sk(sk)->rx_opt.user_mss &&
1143             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1144                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1145
1146         tcp_initialize_rcv_mss(newsk);
1147
1148         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1149         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1150
1151 #ifdef CONFIG_TCP_MD5SIG
1152         /* Copy over the MD5 key from the original socket */
1153         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1154         if (key) {
1155                 /* We're using one, so create a matching key
1156                  * on the newsk structure. If we fail to get
1157                  * memory, then we end up not copying the key
1158                  * across. Shucks.
1159                  */
1160                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1161                                AF_INET6, key->key, key->keylen,
1162                                sk_gfp_mask(sk, GFP_ATOMIC));
1163         }
1164 #endif
1165
1166         if (__inet_inherit_port(sk, newsk) < 0) {
1167                 inet_csk_prepare_forced_close(newsk);
1168                 tcp_done(newsk);
1169                 goto out;
1170         }
1171         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1172         if (*own_req) {
1173                 tcp_move_syn(newtp, req);
1174
1175                 /* Clone pktoptions received with SYN, if we own the req */
1176                 if (ireq->pktopts) {
1177                         newnp->pktoptions = skb_clone(ireq->pktopts,
1178                                                       sk_gfp_mask(sk, GFP_ATOMIC));
1179                         consume_skb(ireq->pktopts);
1180                         ireq->pktopts = NULL;
1181                         if (newnp->pktoptions)
1182                                 skb_set_owner_r(newnp->pktoptions, newsk);
1183                 }
1184         }
1185
1186         return newsk;
1187
1188 out_overflow:
1189         __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1190 out_nonewsk:
1191         dst_release(dst);
1192 out:
1193         tcp_listendrop(sk);
1194         return NULL;
1195 }
1196
1197 static void tcp_v6_restore_cb(struct sk_buff *skb)
1198 {
1199         /* We need to move header back to the beginning if xfrm6_policy_check()
1200          * and tcp_v6_fill_cb() are going to be called again.
1201          * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1202          */
1203         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1204                 sizeof(struct inet6_skb_parm));
1205 }
1206
1207 /* The socket must have it's spinlock held when we get
1208  * here, unless it is a TCP_LISTEN socket.
1209  *
1210  * We have a potential double-lock case here, so even when
1211  * doing backlog processing we use the BH locking scheme.
1212  * This is because we cannot sleep with the original spinlock
1213  * held.
1214  */
1215 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1216 {
1217         struct ipv6_pinfo *np = inet6_sk(sk);
1218         struct tcp_sock *tp;
1219         struct sk_buff *opt_skb = NULL;
1220
1221         /* Imagine: socket is IPv6. IPv4 packet arrives,
1222            goes to IPv4 receive handler and backlogged.
1223            From backlog it always goes here. Kerboom...
1224            Fortunately, tcp_rcv_established and rcv_established
1225            handle them correctly, but it is not case with
1226            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1227          */
1228
1229         if (skb->protocol == htons(ETH_P_IP))
1230                 return tcp_v4_do_rcv(sk, skb);
1231
1232         if (tcp_filter(sk, skb))
1233                 goto discard;
1234
1235         /*
1236          *      socket locking is here for SMP purposes as backlog rcv
1237          *      is currently called with bh processing disabled.
1238          */
1239
1240         /* Do Stevens' IPV6_PKTOPTIONS.
1241
1242            Yes, guys, it is the only place in our code, where we
1243            may make it not affecting IPv4.
1244            The rest of code is protocol independent,
1245            and I do not like idea to uglify IPv4.
1246
1247            Actually, all the idea behind IPV6_PKTOPTIONS
1248            looks not very well thought. For now we latch
1249            options, received in the last packet, enqueued
1250            by tcp. Feel free to propose better solution.
1251                                                --ANK (980728)
1252          */
1253         if (np->rxopt.all)
1254                 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1255
1256         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1257                 struct dst_entry *dst = sk->sk_rx_dst;
1258
1259                 sock_rps_save_rxhash(sk, skb);
1260                 sk_mark_napi_id(sk, skb);
1261                 if (dst) {
1262                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1263                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1264                                 dst_release(dst);
1265                                 sk->sk_rx_dst = NULL;
1266                         }
1267                 }
1268
1269                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1270                 if (opt_skb)
1271                         goto ipv6_pktoptions;
1272                 return 0;
1273         }
1274
1275         if (tcp_checksum_complete(skb))
1276                 goto csum_err;
1277
1278         if (sk->sk_state == TCP_LISTEN) {
1279                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1280
1281                 if (!nsk)
1282                         goto discard;
1283
1284                 if (nsk != sk) {
1285                         sock_rps_save_rxhash(nsk, skb);
1286                         sk_mark_napi_id(nsk, skb);
1287                         if (tcp_child_process(sk, nsk, skb))
1288                                 goto reset;
1289                         if (opt_skb)
1290                                 __kfree_skb(opt_skb);
1291                         return 0;
1292                 }
1293         } else
1294                 sock_rps_save_rxhash(sk, skb);
1295
1296         if (tcp_rcv_state_process(sk, skb))
1297                 goto reset;
1298         if (opt_skb)
1299                 goto ipv6_pktoptions;
1300         return 0;
1301
1302 reset:
1303         tcp_v6_send_reset(sk, skb);
1304 discard:
1305         if (opt_skb)
1306                 __kfree_skb(opt_skb);
1307         kfree_skb(skb);
1308         return 0;
1309 csum_err:
1310         TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1311         TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1312         goto discard;
1313
1314
1315 ipv6_pktoptions:
1316         /* Do you ask, what is it?
1317
1318            1. skb was enqueued by tcp.
1319            2. skb is added to tail of read queue, rather than out of order.
1320            3. socket is not in passive state.
1321            4. Finally, it really contains options, which user wants to receive.
1322          */
1323         tp = tcp_sk(sk);
1324         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1325             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1326                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1327                         np->mcast_oif = tcp_v6_iif(opt_skb);
1328                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1329                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1330                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1331                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1332                 if (np->repflow)
1333                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1334                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1335                         skb_set_owner_r(opt_skb, sk);
1336                         tcp_v6_restore_cb(opt_skb);
1337                         opt_skb = xchg(&np->pktoptions, opt_skb);
1338                 } else {
1339                         __kfree_skb(opt_skb);
1340                         opt_skb = xchg(&np->pktoptions, NULL);
1341                 }
1342         }
1343
1344         kfree_skb(opt_skb);
1345         return 0;
1346 }
1347
1348 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1349                            const struct tcphdr *th)
1350 {
1351         /* This is tricky: we move IP6CB at its correct location into
1352          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1353          * _decode_session6() uses IP6CB().
1354          * barrier() makes sure compiler won't play aliasing games.
1355          */
1356         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1357                 sizeof(struct inet6_skb_parm));
1358         barrier();
1359
1360         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1361         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1362                                     skb->len - th->doff*4);
1363         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1364         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1365         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1366         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1367         TCP_SKB_CB(skb)->sacked = 0;
1368 }
1369
1370 static int tcp_v6_rcv(struct sk_buff *skb)
1371 {
1372         const struct tcphdr *th;
1373         const struct ipv6hdr *hdr;
1374         bool refcounted;
1375         struct sock *sk;
1376         int ret;
1377         struct net *net = dev_net(skb->dev);
1378
1379         if (skb->pkt_type != PACKET_HOST)
1380                 goto discard_it;
1381
1382         /*
1383          *      Count it even if it's bad.
1384          */
1385         __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1386
1387         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1388                 goto discard_it;
1389
1390         th = (const struct tcphdr *)skb->data;
1391
1392         if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1393                 goto bad_packet;
1394         if (!pskb_may_pull(skb, th->doff*4))
1395                 goto discard_it;
1396
1397         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1398                 goto csum_error;
1399
1400         th = (const struct tcphdr *)skb->data;
1401         hdr = ipv6_hdr(skb);
1402
1403 lookup:
1404         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1405                                 th->source, th->dest, inet6_iif(skb),
1406                                 &refcounted);
1407         if (!sk)
1408                 goto no_tcp_socket;
1409
1410 process:
1411         if (sk->sk_state == TCP_TIME_WAIT)
1412                 goto do_time_wait;
1413
1414         if (sk->sk_state == TCP_NEW_SYN_RECV) {
1415                 struct request_sock *req = inet_reqsk(sk);
1416                 struct sock *nsk;
1417
1418                 sk = req->rsk_listener;
1419                 tcp_v6_fill_cb(skb, hdr, th);
1420                 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1421                         sk_drops_add(sk, skb);
1422                         reqsk_put(req);
1423                         goto discard_it;
1424                 }
1425                 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1426                         inet_csk_reqsk_queue_drop_and_put(sk, req);
1427                         goto lookup;
1428                 }
1429                 sock_hold(sk);
1430                 refcounted = true;
1431                 nsk = tcp_check_req(sk, skb, req, false);
1432                 if (!nsk) {
1433                         reqsk_put(req);
1434                         goto discard_and_relse;
1435                 }
1436                 if (nsk == sk) {
1437                         reqsk_put(req);
1438                         tcp_v6_restore_cb(skb);
1439                 } else if (tcp_child_process(sk, nsk, skb)) {
1440                         tcp_v6_send_reset(nsk, skb);
1441                         goto discard_and_relse;
1442                 } else {
1443                         sock_put(sk);
1444                         return 0;
1445                 }
1446         }
1447         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1448                 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1449                 goto discard_and_relse;
1450         }
1451
1452         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1453                 goto discard_and_relse;
1454
1455         tcp_v6_fill_cb(skb, hdr, th);
1456
1457         if (tcp_v6_inbound_md5_hash(sk, skb))
1458                 goto discard_and_relse;
1459
1460         if (tcp_filter(sk, skb))
1461                 goto discard_and_relse;
1462         th = (const struct tcphdr *)skb->data;
1463         hdr = ipv6_hdr(skb);
1464
1465         skb->dev = NULL;
1466
1467         if (sk->sk_state == TCP_LISTEN) {
1468                 ret = tcp_v6_do_rcv(sk, skb);
1469                 goto put_and_return;
1470         }
1471
1472         sk_incoming_cpu_update(sk);
1473
1474         bh_lock_sock_nested(sk);
1475         tcp_segs_in(tcp_sk(sk), skb);
1476         ret = 0;
1477         if (!sock_owned_by_user(sk)) {
1478                 if (!tcp_prequeue(sk, skb))
1479                         ret = tcp_v6_do_rcv(sk, skb);
1480         } else if (tcp_add_backlog(sk, skb)) {
1481                 goto discard_and_relse;
1482         }
1483         bh_unlock_sock(sk);
1484
1485 put_and_return:
1486         if (refcounted)
1487                 sock_put(sk);
1488         return ret ? -1 : 0;
1489
1490 no_tcp_socket:
1491         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1492                 goto discard_it;
1493
1494         tcp_v6_fill_cb(skb, hdr, th);
1495
1496         if (tcp_checksum_complete(skb)) {
1497 csum_error:
1498                 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1499 bad_packet:
1500                 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1501         } else {
1502                 tcp_v6_send_reset(NULL, skb);
1503         }
1504
1505 discard_it:
1506         kfree_skb(skb);
1507         return 0;
1508
1509 discard_and_relse:
1510         sk_drops_add(sk, skb);
1511         if (refcounted)
1512                 sock_put(sk);
1513         goto discard_it;
1514
1515 do_time_wait:
1516         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1517                 inet_twsk_put(inet_twsk(sk));
1518                 goto discard_it;
1519         }
1520
1521         tcp_v6_fill_cb(skb, hdr, th);
1522
1523         if (tcp_checksum_complete(skb)) {
1524                 inet_twsk_put(inet_twsk(sk));
1525                 goto csum_error;
1526         }
1527
1528         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1529         case TCP_TW_SYN:
1530         {
1531                 struct sock *sk2;
1532
1533                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1534                                             skb, __tcp_hdrlen(th),
1535                                             &ipv6_hdr(skb)->saddr, th->source,
1536                                             &ipv6_hdr(skb)->daddr,
1537                                             ntohs(th->dest), tcp_v6_iif(skb));
1538                 if (sk2) {
1539                         struct inet_timewait_sock *tw = inet_twsk(sk);
1540                         inet_twsk_deschedule_put(tw);
1541                         sk = sk2;
1542                         tcp_v6_restore_cb(skb);
1543                         refcounted = false;
1544                         goto process;
1545                 }
1546                 /* Fall through to ACK */
1547         }
1548         case TCP_TW_ACK:
1549                 tcp_v6_timewait_ack(sk, skb);
1550                 break;
1551         case TCP_TW_RST:
1552                 tcp_v6_restore_cb(skb);
1553                 tcp_v6_send_reset(sk, skb);
1554                 inet_twsk_deschedule_put(inet_twsk(sk));
1555                 goto discard_it;
1556         case TCP_TW_SUCCESS:
1557                 ;
1558         }
1559         goto discard_it;
1560 }
1561
1562 static void tcp_v6_early_demux(struct sk_buff *skb)
1563 {
1564         const struct ipv6hdr *hdr;
1565         const struct tcphdr *th;
1566         struct sock *sk;
1567
1568         if (skb->pkt_type != PACKET_HOST)
1569                 return;
1570
1571         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1572                 return;
1573
1574         hdr = ipv6_hdr(skb);
1575         th = tcp_hdr(skb);
1576
1577         if (th->doff < sizeof(struct tcphdr) / 4)
1578                 return;
1579
1580         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1581         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1582                                         &hdr->saddr, th->source,
1583                                         &hdr->daddr, ntohs(th->dest),
1584                                         inet6_iif(skb));
1585         if (sk) {
1586                 skb->sk = sk;
1587                 skb->destructor = sock_edemux;
1588                 if (sk_fullsock(sk)) {
1589                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1590
1591                         if (dst)
1592                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1593                         if (dst &&
1594                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1595                                 skb_dst_set_noref(skb, dst);
1596                 }
1597         }
1598 }
1599
1600 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1601         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1602         .twsk_unique    = tcp_twsk_unique,
1603         .twsk_destructor = tcp_twsk_destructor,
1604 };
1605
1606 static const struct inet_connection_sock_af_ops ipv6_specific = {
1607         .queue_xmit        = inet6_csk_xmit,
1608         .send_check        = tcp_v6_send_check,
1609         .rebuild_header    = inet6_sk_rebuild_header,
1610         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1611         .conn_request      = tcp_v6_conn_request,
1612         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1613         .net_header_len    = sizeof(struct ipv6hdr),
1614         .net_frag_header_len = sizeof(struct frag_hdr),
1615         .setsockopt        = ipv6_setsockopt,
1616         .getsockopt        = ipv6_getsockopt,
1617         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1618         .sockaddr_len      = sizeof(struct sockaddr_in6),
1619         .bind_conflict     = inet6_csk_bind_conflict,
1620 #ifdef CONFIG_COMPAT
1621         .compat_setsockopt = compat_ipv6_setsockopt,
1622         .compat_getsockopt = compat_ipv6_getsockopt,
1623 #endif
1624         .mtu_reduced       = tcp_v6_mtu_reduced,
1625 };
1626
1627 #ifdef CONFIG_TCP_MD5SIG
1628 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1629         .md5_lookup     =       tcp_v6_md5_lookup,
1630         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1631         .md5_parse      =       tcp_v6_parse_md5_keys,
1632 };
1633 #endif
1634
1635 /*
1636  *      TCP over IPv4 via INET6 API
1637  */
1638 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1639         .queue_xmit        = ip_queue_xmit,
1640         .send_check        = tcp_v4_send_check,
1641         .rebuild_header    = inet_sk_rebuild_header,
1642         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1643         .conn_request      = tcp_v6_conn_request,
1644         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1645         .net_header_len    = sizeof(struct iphdr),
1646         .setsockopt        = ipv6_setsockopt,
1647         .getsockopt        = ipv6_getsockopt,
1648         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1649         .sockaddr_len      = sizeof(struct sockaddr_in6),
1650         .bind_conflict     = inet6_csk_bind_conflict,
1651 #ifdef CONFIG_COMPAT
1652         .compat_setsockopt = compat_ipv6_setsockopt,
1653         .compat_getsockopt = compat_ipv6_getsockopt,
1654 #endif
1655         .mtu_reduced       = tcp_v4_mtu_reduced,
1656 };
1657
1658 #ifdef CONFIG_TCP_MD5SIG
1659 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1660         .md5_lookup     =       tcp_v4_md5_lookup,
1661         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1662         .md5_parse      =       tcp_v6_parse_md5_keys,
1663 };
1664 #endif
1665
1666 /* NOTE: A lot of things set to zero explicitly by call to
1667  *       sk_alloc() so need not be done here.
1668  */
1669 static int tcp_v6_init_sock(struct sock *sk)
1670 {
1671         struct inet_connection_sock *icsk = inet_csk(sk);
1672
1673         tcp_init_sock(sk);
1674
1675         icsk->icsk_af_ops = &ipv6_specific;
1676
1677 #ifdef CONFIG_TCP_MD5SIG
1678         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1679 #endif
1680
1681         return 0;
1682 }
1683
1684 static void tcp_v6_destroy_sock(struct sock *sk)
1685 {
1686         tcp_v4_destroy_sock(sk);
1687         inet6_destroy_sock(sk);
1688 }
1689
1690 #ifdef CONFIG_PROC_FS
1691 /* Proc filesystem TCPv6 sock list dumping. */
1692 static void get_openreq6(struct seq_file *seq,
1693                          const struct request_sock *req, int i)
1694 {
1695         long ttd = req->rsk_timer.expires - jiffies;
1696         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1697         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1698
1699         if (ttd < 0)
1700                 ttd = 0;
1701
1702         seq_printf(seq,
1703                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1704                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1705                    i,
1706                    src->s6_addr32[0], src->s6_addr32[1],
1707                    src->s6_addr32[2], src->s6_addr32[3],
1708                    inet_rsk(req)->ir_num,
1709                    dest->s6_addr32[0], dest->s6_addr32[1],
1710                    dest->s6_addr32[2], dest->s6_addr32[3],
1711                    ntohs(inet_rsk(req)->ir_rmt_port),
1712                    TCP_SYN_RECV,
1713                    0, 0, /* could print option size, but that is af dependent. */
1714                    1,   /* timers active (only the expire timer) */
1715                    jiffies_to_clock_t(ttd),
1716                    req->num_timeout,
1717                    from_kuid_munged(seq_user_ns(seq),
1718                                     sock_i_uid(req->rsk_listener)),
1719                    0,  /* non standard timer */
1720                    0, /* open_requests have no inode */
1721                    0, req);
1722 }
1723
1724 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1725 {
1726         const struct in6_addr *dest, *src;
1727         __u16 destp, srcp;
1728         int timer_active;
1729         unsigned long timer_expires;
1730         const struct inet_sock *inet = inet_sk(sp);
1731         const struct tcp_sock *tp = tcp_sk(sp);
1732         const struct inet_connection_sock *icsk = inet_csk(sp);
1733         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1734         int rx_queue;
1735         int state;
1736
1737         dest  = &sp->sk_v6_daddr;
1738         src   = &sp->sk_v6_rcv_saddr;
1739         destp = ntohs(inet->inet_dport);
1740         srcp  = ntohs(inet->inet_sport);
1741
1742         if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1743             icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
1744             icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1745                 timer_active    = 1;
1746                 timer_expires   = icsk->icsk_timeout;
1747         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1748                 timer_active    = 4;
1749                 timer_expires   = icsk->icsk_timeout;
1750         } else if (timer_pending(&sp->sk_timer)) {
1751                 timer_active    = 2;
1752                 timer_expires   = sp->sk_timer.expires;
1753         } else {
1754                 timer_active    = 0;
1755                 timer_expires = jiffies;
1756         }
1757
1758         state = sk_state_load(sp);
1759         if (state == TCP_LISTEN)
1760                 rx_queue = sp->sk_ack_backlog;
1761         else
1762                 /* Because we don't lock the socket,
1763                  * we might find a transient negative value.
1764                  */
1765                 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1766
1767         seq_printf(seq,
1768                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1769                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1770                    i,
1771                    src->s6_addr32[0], src->s6_addr32[1],
1772                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1773                    dest->s6_addr32[0], dest->s6_addr32[1],
1774                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1775                    state,
1776                    tp->write_seq - tp->snd_una,
1777                    rx_queue,
1778                    timer_active,
1779                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1780                    icsk->icsk_retransmits,
1781                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1782                    icsk->icsk_probes_out,
1783                    sock_i_ino(sp),
1784                    atomic_read(&sp->sk_refcnt), sp,
1785                    jiffies_to_clock_t(icsk->icsk_rto),
1786                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1787                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1788                    tp->snd_cwnd,
1789                    state == TCP_LISTEN ?
1790                         fastopenq->max_qlen :
1791                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1792                    );
1793 }
1794
1795 static void get_timewait6_sock(struct seq_file *seq,
1796                                struct inet_timewait_sock *tw, int i)
1797 {
1798         long delta = tw->tw_timer.expires - jiffies;
1799         const struct in6_addr *dest, *src;
1800         __u16 destp, srcp;
1801
1802         dest = &tw->tw_v6_daddr;
1803         src  = &tw->tw_v6_rcv_saddr;
1804         destp = ntohs(tw->tw_dport);
1805         srcp  = ntohs(tw->tw_sport);
1806
1807         seq_printf(seq,
1808                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1809                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1810                    i,
1811                    src->s6_addr32[0], src->s6_addr32[1],
1812                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1813                    dest->s6_addr32[0], dest->s6_addr32[1],
1814                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1815                    tw->tw_substate, 0, 0,
1816                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1817                    atomic_read(&tw->tw_refcnt), tw);
1818 }
1819
1820 static int tcp6_seq_show(struct seq_file *seq, void *v)
1821 {
1822         struct tcp_iter_state *st;
1823         struct sock *sk = v;
1824
1825         if (v == SEQ_START_TOKEN) {
1826                 seq_puts(seq,
1827                          "  sl  "
1828                          "local_address                         "
1829                          "remote_address                        "
1830                          "st tx_queue rx_queue tr tm->when retrnsmt"
1831                          "   uid  timeout inode\n");
1832                 goto out;
1833         }
1834         st = seq->private;
1835
1836         if (sk->sk_state == TCP_TIME_WAIT)
1837                 get_timewait6_sock(seq, v, st->num);
1838         else if (sk->sk_state == TCP_NEW_SYN_RECV)
1839                 get_openreq6(seq, v, st->num);
1840         else
1841                 get_tcp6_sock(seq, v, st->num);
1842 out:
1843         return 0;
1844 }
1845
1846 static const struct file_operations tcp6_afinfo_seq_fops = {
1847         .owner   = THIS_MODULE,
1848         .open    = tcp_seq_open,
1849         .read    = seq_read,
1850         .llseek  = seq_lseek,
1851         .release = seq_release_net
1852 };
1853
1854 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1855         .name           = "tcp6",
1856         .family         = AF_INET6,
1857         .seq_fops       = &tcp6_afinfo_seq_fops,
1858         .seq_ops        = {
1859                 .show           = tcp6_seq_show,
1860         },
1861 };
1862
1863 int __net_init tcp6_proc_init(struct net *net)
1864 {
1865         return tcp_proc_register(net, &tcp6_seq_afinfo);
1866 }
1867
1868 void tcp6_proc_exit(struct net *net)
1869 {
1870         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1871 }
1872 #endif
1873
1874 struct proto tcpv6_prot = {
1875         .name                   = "TCPv6",
1876         .owner                  = THIS_MODULE,
1877         .close                  = tcp_close,
1878         .connect                = tcp_v6_connect,
1879         .disconnect             = tcp_disconnect,
1880         .accept                 = inet_csk_accept,
1881         .ioctl                  = tcp_ioctl,
1882         .init                   = tcp_v6_init_sock,
1883         .destroy                = tcp_v6_destroy_sock,
1884         .shutdown               = tcp_shutdown,
1885         .setsockopt             = tcp_setsockopt,
1886         .getsockopt             = tcp_getsockopt,
1887         .recvmsg                = tcp_recvmsg,
1888         .sendmsg                = tcp_sendmsg,
1889         .sendpage               = tcp_sendpage,
1890         .backlog_rcv            = tcp_v6_do_rcv,
1891         .release_cb             = tcp_release_cb,
1892         .hash                   = inet6_hash,
1893         .unhash                 = inet_unhash,
1894         .get_port               = inet_csk_get_port,
1895         .enter_memory_pressure  = tcp_enter_memory_pressure,
1896         .stream_memory_free     = tcp_stream_memory_free,
1897         .sockets_allocated      = &tcp_sockets_allocated,
1898         .memory_allocated       = &tcp_memory_allocated,
1899         .memory_pressure        = &tcp_memory_pressure,
1900         .orphan_count           = &tcp_orphan_count,
1901         .sysctl_mem             = sysctl_tcp_mem,
1902         .sysctl_wmem            = sysctl_tcp_wmem,
1903         .sysctl_rmem            = sysctl_tcp_rmem,
1904         .max_header             = MAX_TCP_HEADER,
1905         .obj_size               = sizeof(struct tcp6_sock),
1906         .slab_flags             = SLAB_DESTROY_BY_RCU,
1907         .twsk_prot              = &tcp6_timewait_sock_ops,
1908         .rsk_prot               = &tcp6_request_sock_ops,
1909         .h.hashinfo             = &tcp_hashinfo,
1910         .no_autobind            = true,
1911 #ifdef CONFIG_COMPAT
1912         .compat_setsockopt      = compat_tcp_setsockopt,
1913         .compat_getsockopt      = compat_tcp_getsockopt,
1914 #endif
1915         .diag_destroy           = tcp_abort,
1916 };
1917
1918 static const struct inet6_protocol tcpv6_protocol = {
1919         .early_demux    =       tcp_v6_early_demux,
1920         .handler        =       tcp_v6_rcv,
1921         .err_handler    =       tcp_v6_err,
1922         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1923 };
1924
1925 static struct inet_protosw tcpv6_protosw = {
1926         .type           =       SOCK_STREAM,
1927         .protocol       =       IPPROTO_TCP,
1928         .prot           =       &tcpv6_prot,
1929         .ops            =       &inet6_stream_ops,
1930         .flags          =       INET_PROTOSW_PERMANENT |
1931                                 INET_PROTOSW_ICSK,
1932 };
1933
1934 static int __net_init tcpv6_net_init(struct net *net)
1935 {
1936         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1937                                     SOCK_RAW, IPPROTO_TCP, net);
1938 }
1939
1940 static void __net_exit tcpv6_net_exit(struct net *net)
1941 {
1942         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1943 }
1944
1945 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1946 {
1947         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1948 }
1949
1950 static struct pernet_operations tcpv6_net_ops = {
1951         .init       = tcpv6_net_init,
1952         .exit       = tcpv6_net_exit,
1953         .exit_batch = tcpv6_net_exit_batch,
1954 };
1955
1956 int __init tcpv6_init(void)
1957 {
1958         int ret;
1959
1960         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1961         if (ret)
1962                 goto out;
1963
1964         /* register inet6 protocol */
1965         ret = inet6_register_protosw(&tcpv6_protosw);
1966         if (ret)
1967                 goto out_tcpv6_protocol;
1968
1969         ret = register_pernet_subsys(&tcpv6_net_ops);
1970         if (ret)
1971                 goto out_tcpv6_protosw;
1972 out:
1973         return ret;
1974
1975 out_tcpv6_protosw:
1976         inet6_unregister_protosw(&tcpv6_protosw);
1977 out_tcpv6_protocol:
1978         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1979         goto out;
1980 }
1981
1982 void tcpv6_exit(void)
1983 {
1984         unregister_pernet_subsys(&tcpv6_net_ops);
1985         inet6_unregister_protosw(&tcpv6_protosw);
1986         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1987 }