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, sock_owned_by_user(sk));
 238         final_p = fl6_update_dst(&fl6, opt, &final);
 239
 240         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 241
 242         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 243         if (IS_ERR(dst)) {
 244                 err = PTR_ERR(dst);
 245                 goto failure;
 246         }
 247
 248         if (!saddr) {
 249                 saddr = &fl6.saddr;
 250                 sk->sk_v6_rcv_saddr = *saddr;
 251         }
 252
 253         /* set the source address */
 254         np->saddr = *saddr;
 255         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 256
 257         sk->sk_gso_type = SKB_GSO_TCPV6;
 258         ip6_dst_store(sk, dst, NULL, NULL);
 259
 260         if (tcp_death_row.sysctl_tw_recycle &&
 261             !tp->rx_opt.ts_recent_stamp &&
 262             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 263                 tcp_fetch_timewait_stamp(sk, dst);
 264
 265         icsk->icsk_ext_hdr_len = 0;
 266         if (opt)
 267                 icsk->icsk_ext_hdr_len = opt->opt_flen +
 268                                          opt->opt_nflen;
 269
 270         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 271
 272         inet->inet_dport = usin->sin6_port;
 273
 274         tcp_set_state(sk, TCP_SYN_SENT);
 275         err = inet6_hash_connect(&tcp_death_row, sk);
 276         if (err)
 277                 goto late_failure;
 278
 279         sk_set_txhash(sk);
 280
 281         if (!tp->write_seq && likely(!tp->repair))
 282                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 283                                                              sk->sk_v6_daddr.s6_addr32,
 284                                                              inet->inet_sport,
 285                                                              inet->inet_dport);
 286
 287         err = tcp_connect(sk);
 288         if (err)
 289                 goto late_failure;
 290
 291         return 0;
 292
 293 late_failure:
 294         tcp_set_state(sk, TCP_CLOSE);
 295         __sk_dst_reset(sk);
 296 failure:
 297         inet->inet_dport = 0;
 298         sk->sk_route_caps = 0;
 299         return err;
 300 }
 301
 302 static void tcp_v6_mtu_reduced(struct sock *sk)
 303 {
 304         struct dst_entry *dst;
 305
 306         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 307                 return;
 308
 309         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 310         if (!dst)
 311                 return;
 312
 313         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 314                 tcp_sync_mss(sk, dst_mtu(dst));
 315                 tcp_simple_retransmit(sk);
 316         }
 317 }
 318
 319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 320                 u8 type, u8 code, int offset, __be32 info)
 321 {
 322         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 324         struct net *net = dev_net(skb->dev);
 325         struct request_sock *fastopen;
 326         struct ipv6_pinfo *np;
 327         struct tcp_sock *tp;
 328         __u32 seq, snd_una;
 329         struct sock *sk;
 330         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_BH(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_BH(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_BH(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_BH(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                               bool attach_req)
 443 {
 444         struct inet_request_sock *ireq = inet_rsk(req);
 445         struct ipv6_pinfo *np = inet6_sk(sk);
 446         struct flowi6 *fl6 = &fl->u.ip6;
 447         struct sk_buff *skb;
 448         int err = -ENOMEM;
 449
 450         /* First, grab a route. */
 451         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
 452                                                IPPROTO_TCP)) == NULL)
 453                 goto done;
 454
 455         skb = tcp_make_synack(sk, dst, req, foc, attach_req);
 456
 457         if (skb) {
 458                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 459                                     &ireq->ir_v6_rmt_addr);
 460
 461                 fl6->daddr = ireq->ir_v6_rmt_addr;
 462                 if (np->repflow && ireq->pktopts)
 463                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 464
 465                 rcu_read_lock();
 466                 err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt),
 467                                np->tclass);
 468                 rcu_read_unlock();
 469                 err = net_xmit_eval(err);
 470         }
 471
 472 done:
 473         return err;
 474 }
 475
 476
 477 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 478 {
 479         kfree_skb(inet_rsk(req)->pktopts);
 480 }
 481
 482 #ifdef CONFIG_TCP_MD5SIG
 483 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 484                                                    const struct in6_addr *addr)
 485 {
 486         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 487 }
 488
 489 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 490                                                 const struct sock *addr_sk)
 491 {
 492         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 493 }
 494
 495 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 496                                  int optlen)
 497 {
 498         struct tcp_md5sig cmd;
 499         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 500
 501         if (optlen < sizeof(cmd))
 502                 return -EINVAL;
 503
 504         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 505                 return -EFAULT;
 506
 507         if (sin6->sin6_family != AF_INET6)
 508                 return -EINVAL;
 509
 510         if (!cmd.tcpm_keylen) {
 511                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 512                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 513                                               AF_INET);
 514                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 515                                       AF_INET6);
 516         }
 517
 518         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 519                 return -EINVAL;
 520
 521         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 522                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 523                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 524
 525         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 526                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 527 }
 528
 529 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 530                                         const struct in6_addr *daddr,
 531                                         const struct in6_addr *saddr, int nbytes)
 532 {
 533         struct tcp6_pseudohdr *bp;
 534         struct scatterlist sg;
 535
 536         bp = &hp->md5_blk.ip6;
 537         /* 1. TCP pseudo-header (RFC2460) */
 538         bp->saddr = *saddr;
 539         bp->daddr = *daddr;
 540         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 541         bp->len = cpu_to_be32(nbytes);
 542
 543         sg_init_one(&sg, bp, sizeof(*bp));
 544         ahash_request_set_crypt(hp->md5_req, &sg, NULL, sizeof(*bp));
 545         return crypto_ahash_update(hp->md5_req);
 546 }
 547
 548 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 549                                const struct in6_addr *daddr, struct in6_addr *saddr,
 550                                const struct tcphdr *th)
 551 {
 552         struct tcp_md5sig_pool *hp;
 553         struct ahash_request *req;
 554
 555         hp = tcp_get_md5sig_pool();
 556         if (!hp)
 557                 goto clear_hash_noput;
 558         req = hp->md5_req;
 559
 560         if (crypto_ahash_init(req))
 561                 goto clear_hash;
 562         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 563                 goto clear_hash;
 564         if (tcp_md5_hash_header(hp, th))
 565                 goto clear_hash;
 566         if (tcp_md5_hash_key(hp, key))
 567                 goto clear_hash;
 568         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 569         if (crypto_ahash_final(req))
 570                 goto clear_hash;
 571
 572         tcp_put_md5sig_pool();
 573         return 0;
 574
 575 clear_hash:
 576         tcp_put_md5sig_pool();
 577 clear_hash_noput:
 578         memset(md5_hash, 0, 16);
 579         return 1;
 580 }
 581
 582 static int tcp_v6_md5_hash_skb(char *md5_hash,
 583                                const struct tcp_md5sig_key *key,
 584                                const struct sock *sk,
 585                                const struct sk_buff *skb)
 586 {
 587         const struct in6_addr *saddr, *daddr;
 588         struct tcp_md5sig_pool *hp;
 589         struct ahash_request *req;
 590         const struct tcphdr *th = tcp_hdr(skb);
 591
 592         if (sk) { /* valid for establish/request sockets */
 593                 saddr = &sk->sk_v6_rcv_saddr;
 594                 daddr = &sk->sk_v6_daddr;
 595         } else {
 596                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 597                 saddr = &ip6h->saddr;
 598                 daddr = &ip6h->daddr;
 599         }
 600
 601         hp = tcp_get_md5sig_pool();
 602         if (!hp)
 603                 goto clear_hash_noput;
 604         req = hp->md5_req;
 605
 606         if (crypto_ahash_init(req))
 607                 goto clear_hash;
 608
 609         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 610                 goto clear_hash;
 611         if (tcp_md5_hash_header(hp, th))
 612                 goto clear_hash;
 613         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 614                 goto clear_hash;
 615         if (tcp_md5_hash_key(hp, key))
 616                 goto clear_hash;
 617         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 618         if (crypto_ahash_final(req))
 619                 goto clear_hash;
 620
 621         tcp_put_md5sig_pool();
 622         return 0;
 623
 624 clear_hash:
 625         tcp_put_md5sig_pool();
 626 clear_hash_noput:
 627         memset(md5_hash, 0, 16);
 628         return 1;
 629 }
 630
 631 #endif
 632
 633 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 634                                     const struct sk_buff *skb)
 635 {
 636 #ifdef CONFIG_TCP_MD5SIG
 637         const __u8 *hash_location = NULL;
 638         struct tcp_md5sig_key *hash_expected;
 639         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 640         const struct tcphdr *th = tcp_hdr(skb);
 641         int genhash;
 642         u8 newhash[16];
 643
 644         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 645         hash_location = tcp_parse_md5sig_option(th);
 646
 647         /* We've parsed the options - do we have a hash? */
 648         if (!hash_expected && !hash_location)
 649                 return false;
 650
 651         if (hash_expected && !hash_location) {
 652                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 653                 return true;
 654         }
 655
 656         if (!hash_expected && hash_location) {
 657                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 658                 return true;
 659         }
 660
 661         /* check the signature */
 662         genhash = tcp_v6_md5_hash_skb(newhash,
 663                                       hash_expected,
 664                                       NULL, skb);
 665
 666         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 667                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 668                                      genhash ? "failed" : "mismatch",
 669                                      &ip6h->saddr, ntohs(th->source),
 670                                      &ip6h->daddr, ntohs(th->dest));
 671                 return true;
 672         }
 673 #endif
 674         return false;
 675 }
 676
 677 static void tcp_v6_init_req(struct request_sock *req,
 678                             const struct sock *sk_listener,
 679                             struct sk_buff *skb)
 680 {
 681         struct inet_request_sock *ireq = inet_rsk(req);
 682         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 683
 684         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 685         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 686
 687         /* So that link locals have meaning */
 688         if (!sk_listener->sk_bound_dev_if &&
 689             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 690                 ireq->ir_iif = tcp_v6_iif(skb);
 691
 692         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 693             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 694              np->rxopt.bits.rxinfo ||
 695              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 696              np->rxopt.bits.rxohlim || np->repflow)) {
 697                 atomic_inc(&skb->users);
 698                 ireq->pktopts = skb;
 699         }
 700 }
 701
 702 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 703                                           struct flowi *fl,
 704                                           const struct request_sock *req,
 705                                           bool *strict)
 706 {
 707         if (strict)
 708                 *strict = true;
 709         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 710 }
 711
 712 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 713         .family         =       AF_INET6,
 714         .obj_size       =       sizeof(struct tcp6_request_sock),
 715         .rtx_syn_ack    =       tcp_rtx_synack,
 716         .send_ack       =       tcp_v6_reqsk_send_ack,
 717         .destructor     =       tcp_v6_reqsk_destructor,
 718         .send_reset     =       tcp_v6_send_reset,
 719         .syn_ack_timeout =      tcp_syn_ack_timeout,
 720 };
 721
 722 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 723         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 724                                 sizeof(struct ipv6hdr),
 725 #ifdef CONFIG_TCP_MD5SIG
 726         .req_md5_lookup =       tcp_v6_md5_lookup,
 727         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 728 #endif
 729         .init_req       =       tcp_v6_init_req,
 730 #ifdef CONFIG_SYN_COOKIES
 731         .cookie_init_seq =      cookie_v6_init_sequence,
 732 #endif
 733         .route_req      =       tcp_v6_route_req,
 734         .init_seq       =       tcp_v6_init_sequence,
 735         .send_synack    =       tcp_v6_send_synack,
 736 };
 737
 738 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 739                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 740                                  int oif, struct tcp_md5sig_key *key, int rst,
 741                                  u8 tclass, u32 label)
 742 {
 743         const struct tcphdr *th = tcp_hdr(skb);
 744         struct tcphdr *t1;
 745         struct sk_buff *buff;
 746         struct flowi6 fl6;
 747         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 748         struct sock *ctl_sk = net->ipv6.tcp_sk;
 749         unsigned int tot_len = sizeof(struct tcphdr);
 750         struct dst_entry *dst;
 751         __be32 *topt;
 752
 753         if (tsecr)
 754                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 755 #ifdef CONFIG_TCP_MD5SIG
 756         if (key)
 757                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 758 #endif
 759
 760         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 761                          GFP_ATOMIC);
 762         if (!buff)
 763                 return;
 764
 765         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 766
 767         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 768         skb_reset_transport_header(buff);
 769
 770         /* Swap the send and the receive. */
 771         memset(t1, 0, sizeof(*t1));
 772         t1->dest = th->source;
 773         t1->source = th->dest;
 774         t1->doff = tot_len / 4;
 775         t1->seq = htonl(seq);
 776         t1->ack_seq = htonl(ack);
 777         t1->ack = !rst || !th->ack;
 778         t1->rst = rst;
 779         t1->window = htons(win);
 780
 781         topt = (__be32 *)(t1 + 1);
 782
 783         if (tsecr) {
 784                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 785                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 786                 *topt++ = htonl(tsval);
 787                 *topt++ = htonl(tsecr);
 788         }
 789
 790 #ifdef CONFIG_TCP_MD5SIG
 791         if (key) {
 792                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 793                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 794                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 795                                     &ipv6_hdr(skb)->saddr,
 796                                     &ipv6_hdr(skb)->daddr, t1);
 797         }
 798 #endif
 799
 800         memset(&fl6, 0, sizeof(fl6));
 801         fl6.daddr = ipv6_hdr(skb)->saddr;
 802         fl6.saddr = ipv6_hdr(skb)->daddr;
 803         fl6.flowlabel = label;
 804
 805         buff->ip_summed = CHECKSUM_PARTIAL;
 806         buff->csum = 0;
 807
 808         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 809
 810         fl6.flowi6_proto = IPPROTO_TCP;
 811         if (rt6_need_strict(&fl6.daddr) && !oif)
 812                 fl6.flowi6_oif = tcp_v6_iif(skb);
 813         else
 814                 fl6.flowi6_oif = oif;
 815         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 816         fl6.fl6_dport = t1->dest;
 817         fl6.fl6_sport = t1->source;
 818         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 819
 820         /* Pass a socket to ip6_dst_lookup either it is for RST
 821          * Underlying function will use this to retrieve the network
 822          * namespace
 823          */
 824         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 825         if (!IS_ERR(dst)) {
 826                 skb_dst_set(buff, dst);
 827                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 828                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 829                 if (rst)
 830                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 831                 return;
 832         }
 833
 834         kfree_skb(buff);
 835 }
 836
 837 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 838 {
 839         const struct tcphdr *th = tcp_hdr(skb);
 840         u32 seq = 0, ack_seq = 0;
 841         struct tcp_md5sig_key *key = NULL;
 842 #ifdef CONFIG_TCP_MD5SIG
 843         const __u8 *hash_location = NULL;
 844         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 845         unsigned char newhash[16];
 846         int genhash;
 847         struct sock *sk1 = NULL;
 848 #endif
 849         int oif;
 850
 851         if (th->rst)
 852                 return;
 853
 854         /* If sk not NULL, it means we did a successful lookup and incoming
 855          * route had to be correct. prequeue might have dropped our dst.
 856          */
 857         if (!sk && !ipv6_unicast_destination(skb))
 858                 return;
 859
 860 #ifdef CONFIG_TCP_MD5SIG
 861         hash_location = tcp_parse_md5sig_option(th);
 862         if (sk && sk_fullsock(sk)) {
 863                 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
 864         } else if (hash_location) {
 865                 /*
 866                  * active side is lost. Try to find listening socket through
 867                  * source port, and then find md5 key through listening socket.
 868                  * we are not loose security here:
 869                  * Incoming packet is checked with md5 hash with finding key,
 870                  * no RST generated if md5 hash doesn't match.
 871                  */
 872                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 873                                            &tcp_hashinfo, &ipv6h->saddr,
 874                                            th->source, &ipv6h->daddr,
 875                                            ntohs(th->source), tcp_v6_iif(skb));
 876                 if (!sk1)
 877                         return;
 878
 879                 rcu_read_lock();
 880                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 881                 if (!key)
 882                         goto release_sk1;
 883
 884                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 885                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 886                         goto release_sk1;
 887         }
 888 #endif
 889
 890         if (th->ack)
 891                 seq = ntohl(th->ack_seq);
 892         else
 893                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 894                           (th->doff << 2);
 895
 896         oif = sk ? sk->sk_bound_dev_if : 0;
 897         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 898
 899 #ifdef CONFIG_TCP_MD5SIG
 900 release_sk1:
 901         if (sk1) {
 902                 rcu_read_unlock();
 903                 sock_put(sk1);
 904         }
 905 #endif
 906 }
 907
 908 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 909                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 910                             struct tcp_md5sig_key *key, u8 tclass,
 911                             u32 label)
 912 {
 913         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 914                              tclass, label);
 915 }
 916
 917 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 918 {
 919         struct inet_timewait_sock *tw = inet_twsk(sk);
 920         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 921
 922         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 923                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 924                         tcp_time_stamp + tcptw->tw_ts_offset,
 925                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 926                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 927
 928         inet_twsk_put(tw);
 929 }
 930
 931 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 932                                   struct request_sock *req)
 933 {
 934         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 935          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 936          */
 937         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 938                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 939                         tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd,
 940                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 941                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 942                         0, 0);
 943 }
 944
 945
 946 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
 947 {
 948 #ifdef CONFIG_SYN_COOKIES
 949         const struct tcphdr *th = tcp_hdr(skb);
 950
 951         if (!th->syn)
 952                 sk = cookie_v6_check(sk, skb);
 953 #endif
 954         return sk;
 955 }
 956
 957 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 958 {
 959         if (skb->protocol == htons(ETH_P_IP))
 960                 return tcp_v4_conn_request(sk, skb);
 961
 962         if (!ipv6_unicast_destination(skb))
 963                 goto drop;
 964
 965         return tcp_conn_request(&tcp6_request_sock_ops,
 966                                 &tcp_request_sock_ipv6_ops, sk, skb);
 967
 968 drop:
 969         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 970         return 0; /* don't send reset */
 971 }
 972
 973 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 974                                          struct request_sock *req,
 975                                          struct dst_entry *dst,
 976                                          struct request_sock *req_unhash,
 977                                          bool *own_req)
 978 {
 979         struct inet_request_sock *ireq;
 980         struct ipv6_pinfo *newnp;
 981         const struct ipv6_pinfo *np = inet6_sk(sk);
 982         struct ipv6_txoptions *opt;
 983         struct tcp6_sock *newtcp6sk;
 984         struct inet_sock *newinet;
 985         struct tcp_sock *newtp;
 986         struct sock *newsk;
 987 #ifdef CONFIG_TCP_MD5SIG
 988         struct tcp_md5sig_key *key;
 989 #endif
 990         struct flowi6 fl6;
 991
 992         if (skb->protocol == htons(ETH_P_IP)) {
 993                 /*
 994                  *      v6 mapped
 995                  */
 996
 997                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
 998                                              req_unhash, own_req);
 999
1000                 if (!newsk)
1001                         return NULL;
1002
1003                 newtcp6sk = (struct tcp6_sock *)newsk;
1004                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1005
1006                 newinet = inet_sk(newsk);
1007                 newnp = inet6_sk(newsk);
1008                 newtp = tcp_sk(newsk);
1009
1010                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1011
1012                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1013
1014                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1015                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1016 #ifdef CONFIG_TCP_MD5SIG
1017                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1018 #endif
1019
1020                 newnp->ipv6_ac_list = NULL;
1021                 newnp->ipv6_fl_list = NULL;
1022                 newnp->pktoptions  = NULL;
1023                 newnp->opt         = NULL;
1024                 newnp->mcast_oif   = tcp_v6_iif(skb);
1025                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1026                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1027                 if (np->repflow)
1028                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1029
1030                 /*
1031                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1032                  * here, tcp_create_openreq_child now does this for us, see the comment in
1033                  * that function for the gory details. -acme
1034                  */
1035
1036                 /* It is tricky place. Until this moment IPv4 tcp
1037                    worked with IPv6 icsk.icsk_af_ops.
1038                    Sync it now.
1039                  */
1040                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1041
1042                 return newsk;
1043         }
1044
1045         ireq = inet_rsk(req);
1046
1047         if (sk_acceptq_is_full(sk))
1048                 goto out_overflow;
1049
1050         if (!dst) {
1051                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1052                 if (!dst)
1053                         goto out;
1054         }
1055
1056         newsk = tcp_create_openreq_child(sk, req, skb);
1057         if (!newsk)
1058                 goto out_nonewsk;
1059
1060         /*
1061          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1062          * count here, tcp_create_openreq_child now does this for us, see the
1063          * comment in that function for the gory details. -acme
1064          */
1065
1066         newsk->sk_gso_type = SKB_GSO_TCPV6;
1067         ip6_dst_store(newsk, dst, NULL, NULL);
1068         inet6_sk_rx_dst_set(newsk, skb);
1069
1070         newtcp6sk = (struct tcp6_sock *)newsk;
1071         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1072
1073         newtp = tcp_sk(newsk);
1074         newinet = inet_sk(newsk);
1075         newnp = inet6_sk(newsk);
1076
1077         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1078
1079         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1080         newnp->saddr = ireq->ir_v6_loc_addr;
1081         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1082         newsk->sk_bound_dev_if = ireq->ir_iif;
1083
1084         /* Now IPv6 options...
1085
1086            First: no IPv4 options.
1087          */
1088         newinet->inet_opt = NULL;
1089         newnp->ipv6_ac_list = NULL;
1090         newnp->ipv6_fl_list = NULL;
1091
1092         /* Clone RX bits */
1093         newnp->rxopt.all = np->rxopt.all;
1094
1095         newnp->pktoptions = NULL;
1096         newnp->opt        = NULL;
1097         newnp->mcast_oif  = tcp_v6_iif(skb);
1098         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1099         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1100         if (np->repflow)
1101                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1102
1103         /* Clone native IPv6 options from listening socket (if any)
1104
1105            Yes, keeping reference count would be much more clever,
1106            but we make one more one thing there: reattach optmem
1107            to newsk.
1108          */
1109         opt = rcu_dereference(np->opt);
1110         if (opt) {
1111                 opt = ipv6_dup_options(newsk, opt);
1112                 RCU_INIT_POINTER(newnp->opt, opt);
1113         }
1114         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1115         if (opt)
1116                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1117                                                     opt->opt_flen;
1118
1119         tcp_ca_openreq_child(newsk, dst);
1120
1121         tcp_sync_mss(newsk, dst_mtu(dst));
1122         newtp->advmss = dst_metric_advmss(dst);
1123         if (tcp_sk(sk)->rx_opt.user_mss &&
1124             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1125                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1126
1127         tcp_initialize_rcv_mss(newsk);
1128
1129         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1130         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1131
1132 #ifdef CONFIG_TCP_MD5SIG
1133         /* Copy over the MD5 key from the original socket */
1134         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1135         if (key) {
1136                 /* We're using one, so create a matching key
1137                  * on the newsk structure. If we fail to get
1138                  * memory, then we end up not copying the key
1139                  * across. Shucks.
1140                  */
1141                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1142                                AF_INET6, key->key, key->keylen,
1143                                sk_gfp_mask(sk, GFP_ATOMIC));
1144         }
1145 #endif
1146
1147         if (__inet_inherit_port(sk, newsk) < 0) {
1148                 inet_csk_prepare_forced_close(newsk);
1149                 tcp_done(newsk);
1150                 goto out;
1151         }
1152         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1153         if (*own_req) {
1154                 tcp_move_syn(newtp, req);
1155
1156                 /* Clone pktoptions received with SYN, if we own the req */
1157                 if (ireq->pktopts) {
1158                         newnp->pktoptions = skb_clone(ireq->pktopts,
1159                                                       sk_gfp_mask(sk, GFP_ATOMIC));
1160                         consume_skb(ireq->pktopts);
1161                         ireq->pktopts = NULL;
1162                         if (newnp->pktoptions)
1163                                 skb_set_owner_r(newnp->pktoptions, newsk);
1164                 }
1165         }
1166
1167         return newsk;
1168
1169 out_overflow:
1170         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1171 out_nonewsk:
1172         dst_release(dst);
1173 out:
1174         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1175         return NULL;
1176 }
1177
1178 /* The socket must have it's spinlock held when we get
1179  * here, unless it is a TCP_LISTEN socket.
1180  *
1181  * We have a potential double-lock case here, so even when
1182  * doing backlog processing we use the BH locking scheme.
1183  * This is because we cannot sleep with the original spinlock
1184  * held.
1185  */
1186 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1187 {
1188         struct ipv6_pinfo *np = inet6_sk(sk);
1189         struct tcp_sock *tp;
1190         struct sk_buff *opt_skb = NULL;
1191
1192         /* Imagine: socket is IPv6. IPv4 packet arrives,
1193            goes to IPv4 receive handler and backlogged.
1194            From backlog it always goes here. Kerboom...
1195            Fortunately, tcp_rcv_established and rcv_established
1196            handle them correctly, but it is not case with
1197            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1198          */
1199
1200         if (skb->protocol == htons(ETH_P_IP))
1201                 return tcp_v4_do_rcv(sk, skb);
1202
1203         if (sk_filter(sk, skb))
1204                 goto discard;
1205
1206         /*
1207          *      socket locking is here for SMP purposes as backlog rcv
1208          *      is currently called with bh processing disabled.
1209          */
1210
1211         /* Do Stevens' IPV6_PKTOPTIONS.
1212
1213            Yes, guys, it is the only place in our code, where we
1214            may make it not affecting IPv4.
1215            The rest of code is protocol independent,
1216            and I do not like idea to uglify IPv4.
1217
1218            Actually, all the idea behind IPV6_PKTOPTIONS
1219            looks not very well thought. For now we latch
1220            options, received in the last packet, enqueued
1221            by tcp. Feel free to propose better solution.
1222                                                --ANK (980728)
1223          */
1224         if (np->rxopt.all)
1225                 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1226
1227         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1228                 struct dst_entry *dst = sk->sk_rx_dst;
1229
1230                 sock_rps_save_rxhash(sk, skb);
1231                 sk_mark_napi_id(sk, skb);
1232                 if (dst) {
1233                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1234                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1235                                 dst_release(dst);
1236                                 sk->sk_rx_dst = NULL;
1237                         }
1238                 }
1239
1240                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1241                 if (opt_skb)
1242                         goto ipv6_pktoptions;
1243                 return 0;
1244         }
1245
1246         if (tcp_checksum_complete(skb))
1247                 goto csum_err;
1248
1249         if (sk->sk_state == TCP_LISTEN) {
1250                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1251
1252                 if (!nsk)
1253                         goto discard;
1254
1255                 if (nsk != sk) {
1256                         sock_rps_save_rxhash(nsk, skb);
1257                         sk_mark_napi_id(nsk, skb);
1258                         if (tcp_child_process(sk, nsk, skb))
1259                                 goto reset;
1260                         if (opt_skb)
1261                                 __kfree_skb(opt_skb);
1262                         return 0;
1263                 }
1264         } else
1265                 sock_rps_save_rxhash(sk, skb);
1266
1267         if (tcp_rcv_state_process(sk, skb))
1268                 goto reset;
1269         if (opt_skb)
1270                 goto ipv6_pktoptions;
1271         return 0;
1272
1273 reset:
1274         tcp_v6_send_reset(sk, skb);
1275 discard:
1276         if (opt_skb)
1277                 __kfree_skb(opt_skb);
1278         kfree_skb(skb);
1279         return 0;
1280 csum_err:
1281         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1282         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1283         goto discard;
1284
1285
1286 ipv6_pktoptions:
1287         /* Do you ask, what is it?
1288
1289            1. skb was enqueued by tcp.
1290            2. skb is added to tail of read queue, rather than out of order.
1291            3. socket is not in passive state.
1292            4. Finally, it really contains options, which user wants to receive.
1293          */
1294         tp = tcp_sk(sk);
1295         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1296             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1297                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1298                         np->mcast_oif = tcp_v6_iif(opt_skb);
1299                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1300                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1301                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1302                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1303                 if (np->repflow)
1304                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1305                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1306                         skb_set_owner_r(opt_skb, sk);
1307                         opt_skb = xchg(&np->pktoptions, opt_skb);
1308                 } else {
1309                         __kfree_skb(opt_skb);
1310                         opt_skb = xchg(&np->pktoptions, NULL);
1311                 }
1312         }
1313
1314         kfree_skb(opt_skb);
1315         return 0;
1316 }
1317
1318 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1319                            const struct tcphdr *th)
1320 {
1321         /* This is tricky: we move IP6CB at its correct location into
1322          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1323          * _decode_session6() uses IP6CB().
1324          * barrier() makes sure compiler won't play aliasing games.
1325          */
1326         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1327                 sizeof(struct inet6_skb_parm));
1328         barrier();
1329
1330         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1331         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1332                                     skb->len - th->doff*4);
1333         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1334         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1335         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1336         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1337         TCP_SKB_CB(skb)->sacked = 0;
1338 }
1339
1340 static void tcp_v6_restore_cb(struct sk_buff *skb)
1341 {
1342         /* We need to move header back to the beginning if xfrm6_policy_check()
1343          * and tcp_v6_fill_cb() are going to be called again.
1344          */
1345         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1346                 sizeof(struct inet6_skb_parm));
1347 }
1348
1349 static int tcp_v6_rcv(struct sk_buff *skb)
1350 {
1351         const struct tcphdr *th;
1352         const struct ipv6hdr *hdr;
1353         struct sock *sk;
1354         int ret;
1355         struct net *net = dev_net(skb->dev);
1356
1357         if (skb->pkt_type != PACKET_HOST)
1358                 goto discard_it;
1359
1360         /*
1361          *      Count it even if it's bad.
1362          */
1363         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1364
1365         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1366                 goto discard_it;
1367
1368         th = tcp_hdr(skb);
1369
1370         if (th->doff < sizeof(struct tcphdr)/4)
1371                 goto bad_packet;
1372         if (!pskb_may_pull(skb, th->doff*4))
1373                 goto discard_it;
1374
1375         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1376                 goto csum_error;
1377
1378         th = tcp_hdr(skb);
1379         hdr = ipv6_hdr(skb);
1380
1381 lookup:
1382         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1383                                 inet6_iif(skb));
1384         if (!sk)
1385                 goto no_tcp_socket;
1386
1387 process:
1388         if (sk->sk_state == TCP_TIME_WAIT)
1389                 goto do_time_wait;
1390
1391         if (sk->sk_state == TCP_NEW_SYN_RECV) {
1392                 struct request_sock *req = inet_reqsk(sk);
1393                 struct sock *nsk = NULL;
1394
1395                 sk = req->rsk_listener;
1396                 tcp_v6_fill_cb(skb, hdr, th);
1397                 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1398                         reqsk_put(req);
1399                         goto discard_it;
1400                 }
1401                 if (likely(sk->sk_state == TCP_LISTEN)) {
1402                         nsk = tcp_check_req(sk, skb, req, false);
1403                 } else {
1404                         inet_csk_reqsk_queue_drop_and_put(sk, req);
1405                         goto lookup;
1406                 }
1407                 if (!nsk) {
1408                         reqsk_put(req);
1409                         goto discard_it;
1410                 }
1411                 if (nsk == sk) {
1412                         sock_hold(sk);
1413                         reqsk_put(req);
1414                         tcp_v6_restore_cb(skb);
1415                 } else if (tcp_child_process(sk, nsk, skb)) {
1416                         tcp_v6_send_reset(nsk, skb);
1417                         goto discard_it;
1418                 } else {
1419                         return 0;
1420                 }
1421         }
1422         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1423                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1424                 goto discard_and_relse;
1425         }
1426
1427         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1428                 goto discard_and_relse;
1429
1430         tcp_v6_fill_cb(skb, hdr, th);
1431
1432         if (tcp_v6_inbound_md5_hash(sk, skb))
1433                 goto discard_and_relse;
1434
1435         if (sk_filter(sk, skb))
1436                 goto discard_and_relse;
1437
1438         skb->dev = NULL;
1439
1440         if (sk->sk_state == TCP_LISTEN) {
1441                 ret = tcp_v6_do_rcv(sk, skb);
1442                 goto put_and_return;
1443         }
1444
1445         sk_incoming_cpu_update(sk);
1446
1447         bh_lock_sock_nested(sk);
1448         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1449         ret = 0;
1450         if (!sock_owned_by_user(sk)) {
1451                 if (!tcp_prequeue(sk, skb))
1452                         ret = tcp_v6_do_rcv(sk, skb);
1453         } else if (unlikely(sk_add_backlog(sk, skb,
1454                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1455                 bh_unlock_sock(sk);
1456                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1457                 goto discard_and_relse;
1458         }
1459         bh_unlock_sock(sk);
1460
1461 put_and_return:
1462         sock_put(sk);
1463         return ret ? -1 : 0;
1464
1465 no_tcp_socket:
1466         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1467                 goto discard_it;
1468
1469         tcp_v6_fill_cb(skb, hdr, th);
1470
1471         if (tcp_checksum_complete(skb)) {
1472 csum_error:
1473                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1474 bad_packet:
1475                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1476         } else {
1477                 tcp_v6_send_reset(NULL, skb);
1478         }
1479
1480 discard_it:
1481         kfree_skb(skb);
1482         return 0;
1483
1484 discard_and_relse:
1485         sock_put(sk);
1486         goto discard_it;
1487
1488 do_time_wait:
1489         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1490                 inet_twsk_put(inet_twsk(sk));
1491                 goto discard_it;
1492         }
1493
1494         tcp_v6_fill_cb(skb, hdr, th);
1495
1496         if (tcp_checksum_complete(skb)) {
1497                 inet_twsk_put(inet_twsk(sk));
1498                 goto csum_error;
1499         }
1500
1501         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1502         case TCP_TW_SYN:
1503         {
1504                 struct sock *sk2;
1505
1506                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1507                                             &ipv6_hdr(skb)->saddr, th->source,
1508                                             &ipv6_hdr(skb)->daddr,
1509                                             ntohs(th->dest), tcp_v6_iif(skb));
1510                 if (sk2) {
1511                         struct inet_timewait_sock *tw = inet_twsk(sk);
1512                         inet_twsk_deschedule_put(tw);
1513                         sk = sk2;
1514                         tcp_v6_restore_cb(skb);
1515                         goto process;
1516                 }
1517                 /* Fall through to ACK */
1518         }
1519         case TCP_TW_ACK:
1520                 tcp_v6_timewait_ack(sk, skb);
1521                 break;
1522         case TCP_TW_RST:
1523                 tcp_v6_restore_cb(skb);
1524                 tcp_v6_send_reset(sk, skb);
1525                 inet_twsk_deschedule_put(inet_twsk(sk));
1526                 goto discard_it;
1527         case TCP_TW_SUCCESS:
1528                 ;
1529         }
1530         goto discard_it;
1531 }
1532
1533 static void tcp_v6_early_demux(struct sk_buff *skb)
1534 {
1535         const struct ipv6hdr *hdr;
1536         const struct tcphdr *th;
1537         struct sock *sk;
1538
1539         if (skb->pkt_type != PACKET_HOST)
1540                 return;
1541
1542         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1543                 return;
1544
1545         hdr = ipv6_hdr(skb);
1546         th = tcp_hdr(skb);
1547
1548         if (th->doff < sizeof(struct tcphdr) / 4)
1549                 return;
1550
1551         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1552         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1553                                         &hdr->saddr, th->source,
1554                                         &hdr->daddr, ntohs(th->dest),
1555                                         inet6_iif(skb));
1556         if (sk) {
1557                 skb->sk = sk;
1558                 skb->destructor = sock_edemux;
1559                 if (sk_fullsock(sk)) {
1560                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1561
1562                         if (dst)
1563                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1564                         if (dst &&
1565                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1566                                 skb_dst_set_noref(skb, dst);
1567                 }
1568         }
1569 }
1570
1571 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1572         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1573         .twsk_unique    = tcp_twsk_unique,
1574         .twsk_destructor = tcp_twsk_destructor,
1575 };
1576
1577 static const struct inet_connection_sock_af_ops ipv6_specific = {
1578         .queue_xmit        = inet6_csk_xmit,
1579         .send_check        = tcp_v6_send_check,
1580         .rebuild_header    = inet6_sk_rebuild_header,
1581         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1582         .conn_request      = tcp_v6_conn_request,
1583         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1584         .net_header_len    = sizeof(struct ipv6hdr),
1585         .net_frag_header_len = sizeof(struct frag_hdr),
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_v6_mtu_reduced,
1596 };
1597
1598 #ifdef CONFIG_TCP_MD5SIG
1599 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1600         .md5_lookup     =       tcp_v6_md5_lookup,
1601         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1602         .md5_parse      =       tcp_v6_parse_md5_keys,
1603 };
1604 #endif
1605
1606 /*
1607  *      TCP over IPv4 via INET6 API
1608  */
1609 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1610         .queue_xmit        = ip_queue_xmit,
1611         .send_check        = tcp_v4_send_check,
1612         .rebuild_header    = inet_sk_rebuild_header,
1613         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1614         .conn_request      = tcp_v6_conn_request,
1615         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1616         .net_header_len    = sizeof(struct iphdr),
1617         .setsockopt        = ipv6_setsockopt,
1618         .getsockopt        = ipv6_getsockopt,
1619         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1620         .sockaddr_len      = sizeof(struct sockaddr_in6),
1621         .bind_conflict     = inet6_csk_bind_conflict,
1622 #ifdef CONFIG_COMPAT
1623         .compat_setsockopt = compat_ipv6_setsockopt,
1624         .compat_getsockopt = compat_ipv6_getsockopt,
1625 #endif
1626         .mtu_reduced       = tcp_v4_mtu_reduced,
1627 };
1628
1629 #ifdef CONFIG_TCP_MD5SIG
1630 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1631         .md5_lookup     =       tcp_v4_md5_lookup,
1632         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1633         .md5_parse      =       tcp_v6_parse_md5_keys,
1634 };
1635 #endif
1636
1637 /* NOTE: A lot of things set to zero explicitly by call to
1638  *       sk_alloc() so need not be done here.
1639  */
1640 static int tcp_v6_init_sock(struct sock *sk)
1641 {
1642         struct inet_connection_sock *icsk = inet_csk(sk);
1643
1644         tcp_init_sock(sk);
1645
1646         icsk->icsk_af_ops = &ipv6_specific;
1647
1648 #ifdef CONFIG_TCP_MD5SIG
1649         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1650 #endif
1651
1652         return 0;
1653 }
1654
1655 static void tcp_v6_destroy_sock(struct sock *sk)
1656 {
1657         tcp_v4_destroy_sock(sk);
1658         inet6_destroy_sock(sk);
1659 }
1660
1661 #ifdef CONFIG_PROC_FS
1662 /* Proc filesystem TCPv6 sock list dumping. */
1663 static void get_openreq6(struct seq_file *seq,
1664                          const struct request_sock *req, int i)
1665 {
1666         long ttd = req->rsk_timer.expires - jiffies;
1667         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1668         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1669
1670         if (ttd < 0)
1671                 ttd = 0;
1672
1673         seq_printf(seq,
1674                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1675                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1676                    i,
1677                    src->s6_addr32[0], src->s6_addr32[1],
1678                    src->s6_addr32[2], src->s6_addr32[3],
1679                    inet_rsk(req)->ir_num,
1680                    dest->s6_addr32[0], dest->s6_addr32[1],
1681                    dest->s6_addr32[2], dest->s6_addr32[3],
1682                    ntohs(inet_rsk(req)->ir_rmt_port),
1683                    TCP_SYN_RECV,
1684                    0, 0, /* could print option size, but that is af dependent. */
1685                    1,   /* timers active (only the expire timer) */
1686                    jiffies_to_clock_t(ttd),
1687                    req->num_timeout,
1688                    from_kuid_munged(seq_user_ns(seq),
1689                                     sock_i_uid(req->rsk_listener)),
1690                    0,  /* non standard timer */
1691                    0, /* open_requests have no inode */
1692                    0, req);
1693 }
1694
1695 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1696 {
1697         const struct in6_addr *dest, *src;
1698         __u16 destp, srcp;
1699         int timer_active;
1700         unsigned long timer_expires;
1701         const struct inet_sock *inet = inet_sk(sp);
1702         const struct tcp_sock *tp = tcp_sk(sp);
1703         const struct inet_connection_sock *icsk = inet_csk(sp);
1704         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1705         int rx_queue;
1706         int state;
1707
1708         dest  = &sp->sk_v6_daddr;
1709         src   = &sp->sk_v6_rcv_saddr;
1710         destp = ntohs(inet->inet_dport);
1711         srcp  = ntohs(inet->inet_sport);
1712
1713         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1714                 timer_active    = 1;
1715                 timer_expires   = icsk->icsk_timeout;
1716         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1717                 timer_active    = 4;
1718                 timer_expires   = icsk->icsk_timeout;
1719         } else if (timer_pending(&sp->sk_timer)) {
1720                 timer_active    = 2;
1721                 timer_expires   = sp->sk_timer.expires;
1722         } else {
1723                 timer_active    = 0;
1724                 timer_expires = jiffies;
1725         }
1726
1727         state = sk_state_load(sp);
1728         if (state == TCP_LISTEN)
1729                 rx_queue = sp->sk_ack_backlog;
1730         else
1731                 /* Because we don't lock the socket,
1732                  * we might find a transient negative value.
1733                  */
1734                 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1735
1736         seq_printf(seq,
1737                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1738                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1739                    i,
1740                    src->s6_addr32[0], src->s6_addr32[1],
1741                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1742                    dest->s6_addr32[0], dest->s6_addr32[1],
1743                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1744                    state,
1745                    tp->write_seq - tp->snd_una,
1746                    rx_queue,
1747                    timer_active,
1748                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1749                    icsk->icsk_retransmits,
1750                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1751                    icsk->icsk_probes_out,
1752                    sock_i_ino(sp),
1753                    atomic_read(&sp->sk_refcnt), sp,
1754                    jiffies_to_clock_t(icsk->icsk_rto),
1755                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1756                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1757                    tp->snd_cwnd,
1758                    state == TCP_LISTEN ?
1759                         fastopenq->max_qlen :
1760                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1761                    );
1762 }
1763
1764 static void get_timewait6_sock(struct seq_file *seq,
1765                                struct inet_timewait_sock *tw, int i)
1766 {
1767         long delta = tw->tw_timer.expires - jiffies;
1768         const struct in6_addr *dest, *src;
1769         __u16 destp, srcp;
1770
1771         dest = &tw->tw_v6_daddr;
1772         src  = &tw->tw_v6_rcv_saddr;
1773         destp = ntohs(tw->tw_dport);
1774         srcp  = ntohs(tw->tw_sport);
1775
1776         seq_printf(seq,
1777                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1778                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1779                    i,
1780                    src->s6_addr32[0], src->s6_addr32[1],
1781                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1782                    dest->s6_addr32[0], dest->s6_addr32[1],
1783                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1784                    tw->tw_substate, 0, 0,
1785                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1786                    atomic_read(&tw->tw_refcnt), tw);
1787 }
1788
1789 static int tcp6_seq_show(struct seq_file *seq, void *v)
1790 {
1791         struct tcp_iter_state *st;
1792         struct sock *sk = v;
1793
1794         if (v == SEQ_START_TOKEN) {
1795                 seq_puts(seq,
1796                          "  sl  "
1797                          "local_address                         "
1798                          "remote_address                        "
1799                          "st tx_queue rx_queue tr tm->when retrnsmt"
1800                          "   uid  timeout inode\n");
1801                 goto out;
1802         }
1803         st = seq->private;
1804
1805         if (sk->sk_state == TCP_TIME_WAIT)
1806                 get_timewait6_sock(seq, v, st->num);
1807         else if (sk->sk_state == TCP_NEW_SYN_RECV)
1808                 get_openreq6(seq, v, st->num);
1809         else
1810                 get_tcp6_sock(seq, v, st->num);
1811 out:
1812         return 0;
1813 }
1814
1815 static const struct file_operations tcp6_afinfo_seq_fops = {
1816         .owner   = THIS_MODULE,
1817         .open    = tcp_seq_open,
1818         .read    = seq_read,
1819         .llseek  = seq_lseek,
1820         .release = seq_release_net
1821 };
1822
1823 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1824         .name           = "tcp6",
1825         .family         = AF_INET6,
1826         .seq_fops       = &tcp6_afinfo_seq_fops,
1827         .seq_ops        = {
1828                 .show           = tcp6_seq_show,
1829         },
1830 };
1831
1832 int __net_init tcp6_proc_init(struct net *net)
1833 {
1834         return tcp_proc_register(net, &tcp6_seq_afinfo);
1835 }
1836
1837 void tcp6_proc_exit(struct net *net)
1838 {
1839         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1840 }
1841 #endif
1842
1843 static void tcp_v6_clear_sk(struct sock *sk, int size)
1844 {
1845         struct inet_sock *inet = inet_sk(sk);
1846
1847         /* we do not want to clear pinet6 field, because of RCU lookups */
1848         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1849
1850         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1851         memset(&inet->pinet6 + 1, 0, size);
1852 }
1853
1854 struct proto tcpv6_prot = {
1855         .name                   = "TCPv6",
1856         .owner                  = THIS_MODULE,
1857         .close                  = tcp_close,
1858         .connect                = tcp_v6_connect,
1859         .disconnect             = tcp_disconnect,
1860         .accept                 = inet_csk_accept,
1861         .ioctl                  = tcp_ioctl,
1862         .init                   = tcp_v6_init_sock,
1863         .destroy                = tcp_v6_destroy_sock,
1864         .shutdown               = tcp_shutdown,
1865         .setsockopt             = tcp_setsockopt,
1866         .getsockopt             = tcp_getsockopt,
1867         .recvmsg                = tcp_recvmsg,
1868         .sendmsg                = tcp_sendmsg,
1869         .sendpage               = tcp_sendpage,
1870         .backlog_rcv            = tcp_v6_do_rcv,
1871         .release_cb             = tcp_release_cb,
1872         .hash                   = inet_hash,
1873         .unhash                 = inet_unhash,
1874         .get_port               = inet_csk_get_port,
1875         .enter_memory_pressure  = tcp_enter_memory_pressure,
1876         .stream_memory_free     = tcp_stream_memory_free,
1877         .sockets_allocated      = &tcp_sockets_allocated,
1878         .memory_allocated       = &tcp_memory_allocated,
1879         .memory_pressure        = &tcp_memory_pressure,
1880         .orphan_count           = &tcp_orphan_count,
1881         .sysctl_mem             = sysctl_tcp_mem,
1882         .sysctl_wmem            = sysctl_tcp_wmem,
1883         .sysctl_rmem            = sysctl_tcp_rmem,
1884         .max_header             = MAX_TCP_HEADER,
1885         .obj_size               = sizeof(struct tcp6_sock),
1886         .slab_flags             = SLAB_DESTROY_BY_RCU,
1887         .twsk_prot              = &tcp6_timewait_sock_ops,
1888         .rsk_prot               = &tcp6_request_sock_ops,
1889         .h.hashinfo             = &tcp_hashinfo,
1890         .no_autobind            = true,
1891 #ifdef CONFIG_COMPAT
1892         .compat_setsockopt      = compat_tcp_setsockopt,
1893         .compat_getsockopt      = compat_tcp_getsockopt,
1894 #endif
1895         .clear_sk               = tcp_v6_clear_sk,
1896         .diag_destroy           = tcp_abort,
1897 };
1898
1899 static const struct inet6_protocol tcpv6_protocol = {
1900         .early_demux    =       tcp_v6_early_demux,
1901         .handler        =       tcp_v6_rcv,
1902         .err_handler    =       tcp_v6_err,
1903         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1904 };
1905
1906 static struct inet_protosw tcpv6_protosw = {
1907         .type           =       SOCK_STREAM,
1908         .protocol       =       IPPROTO_TCP,
1909         .prot           =       &tcpv6_prot,
1910         .ops            =       &inet6_stream_ops,
1911         .flags          =       INET_PROTOSW_PERMANENT |
1912                                 INET_PROTOSW_ICSK,
1913 };
1914
1915 static int __net_init tcpv6_net_init(struct net *net)
1916 {
1917         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1918                                     SOCK_RAW, IPPROTO_TCP, net);
1919 }
1920
1921 static void __net_exit tcpv6_net_exit(struct net *net)
1922 {
1923         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1924 }
1925
1926 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1927 {
1928         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1929 }
1930
1931 static struct pernet_operations tcpv6_net_ops = {
1932         .init       = tcpv6_net_init,
1933         .exit       = tcpv6_net_exit,
1934         .exit_batch = tcpv6_net_exit_batch,
1935 };
1936
1937 int __init tcpv6_init(void)
1938 {
1939         int ret;
1940
1941         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1942         if (ret)
1943                 goto out;
1944
1945         /* register inet6 protocol */
1946         ret = inet6_register_protosw(&tcpv6_protosw);
1947         if (ret)
1948                 goto out_tcpv6_protocol;
1949
1950         ret = register_pernet_subsys(&tcpv6_net_ops);
1951         if (ret)
1952                 goto out_tcpv6_protosw;
1953 out:
1954         return ret;
1955
1956 out_tcpv6_protosw:
1957         inet6_unregister_protosw(&tcpv6_protosw);
1958 out_tcpv6_protocol:
1959         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1960         goto out;
1961 }
1962
1963 void tcpv6_exit(void)
1964 {
1965         unregister_pernet_subsys(&tcpv6_net_ops);
1966         inet6_unregister_protosw(&tcpv6_protosw);
1967         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1968 }