net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/inet_common.h>
  63 #include <net/secure_seq.h>
  64 #include <net/tcp_memcontrol.h>
  65 #include <net/busy_poll.h>
  66
  67 #include <linux/proc_fs.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <linux/crypto.h>
  71 #include <linux/scatterlist.h>
  72
  73 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  74 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  75                                       struct request_sock *req);
  76
  77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  78
  79 static const struct inet_connection_sock_af_ops ipv6_mapped;
  80 static const struct inet_connection_sock_af_ops ipv6_specific;
  81 #ifdef CONFIG_TCP_MD5SIG
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  83 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  84 #else
  85 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  86                                                    const struct in6_addr *addr)
  87 {
  88         return NULL;
  89 }
  90 #endif
  91
  92 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  93 {
  94         struct dst_entry *dst = skb_dst(skb);
  95
  96         if (dst) {
  97                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  98
  99                 dst_hold(dst);
 100                 sk->sk_rx_dst = dst;
 101                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 102                 if (rt->rt6i_node)
 103                         inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
 104         }
 105 }
 106
 107 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 108 {
 109         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 110                                             ipv6_hdr(skb)->saddr.s6_addr32,
 111                                             tcp_hdr(skb)->dest,
 112                                             tcp_hdr(skb)->source);
 113 }
 114
 115 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 116                           int addr_len)
 117 {
 118         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 119         struct inet_sock *inet = inet_sk(sk);
 120         struct inet_connection_sock *icsk = inet_csk(sk);
 121         struct ipv6_pinfo *np = inet6_sk(sk);
 122         struct tcp_sock *tp = tcp_sk(sk);
 123         struct in6_addr *saddr = NULL, *final_p, final;
 124         struct rt6_info *rt;
 125         struct flowi6 fl6;
 126         struct dst_entry *dst;
 127         int addr_type;
 128         int err;
 129
 130         if (addr_len < SIN6_LEN_RFC2133)
 131                 return -EINVAL;
 132
 133         if (usin->sin6_family != AF_INET6)
 134                 return -EAFNOSUPPORT;
 135
 136         memset(&fl6, 0, sizeof(fl6));
 137
 138         if (np->sndflow) {
 139                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 140                 IP6_ECN_flow_init(fl6.flowlabel);
 141                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 142                         struct ip6_flowlabel *flowlabel;
 143                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 144                         if (flowlabel == NULL)
 145                                 return -EINVAL;
 146                         fl6_sock_release(flowlabel);
 147                 }
 148         }
 149
 150         /*
 151          *      connect() to INADDR_ANY means loopback (BSD'ism).
 152          */
 153
 154         if (ipv6_addr_any(&usin->sin6_addr))
 155                 usin->sin6_addr.s6_addr[15] = 0x1;
 156
 157         addr_type = ipv6_addr_type(&usin->sin6_addr);
 158
 159         if (addr_type & IPV6_ADDR_MULTICAST)
 160                 return -ENETUNREACH;
 161
 162         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 163                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 164                     usin->sin6_scope_id) {
 165                         /* If interface is set while binding, indices
 166                          * must coincide.
 167                          */
 168                         if (sk->sk_bound_dev_if &&
 169                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 170                                 return -EINVAL;
 171
 172                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 173                 }
 174
 175                 /* Connect to link-local address requires an interface */
 176                 if (!sk->sk_bound_dev_if)
 177                         return -EINVAL;
 178         }
 179
 180         if (tp->rx_opt.ts_recent_stamp &&
 181             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 182                 tp->rx_opt.ts_recent = 0;
 183                 tp->rx_opt.ts_recent_stamp = 0;
 184                 tp->write_seq = 0;
 185         }
 186
 187         sk->sk_v6_daddr = usin->sin6_addr;
 188         np->flow_label = fl6.flowlabel;
 189
 190         /*
 191          *      TCP over IPv4
 192          */
 193
 194         if (addr_type == IPV6_ADDR_MAPPED) {
 195                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 196                 struct sockaddr_in sin;
 197
 198                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 199
 200                 if (__ipv6_only_sock(sk))
 201                         return -ENETUNREACH;
 202
 203                 sin.sin_family = AF_INET;
 204                 sin.sin_port = usin->sin6_port;
 205                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 206
 207                 icsk->icsk_af_ops = &ipv6_mapped;
 208                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 209 #ifdef CONFIG_TCP_MD5SIG
 210                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 211 #endif
 212
 213                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 214
 215                 if (err) {
 216                         icsk->icsk_ext_hdr_len = exthdrlen;
 217                         icsk->icsk_af_ops = &ipv6_specific;
 218                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 219 #ifdef CONFIG_TCP_MD5SIG
 220                         tp->af_specific = &tcp_sock_ipv6_specific;
 221 #endif
 222                         goto failure;
 223                 }
 224                 np->saddr = sk->sk_v6_rcv_saddr;
 225
 226                 return err;
 227         }
 228
 229         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 230                 saddr = &sk->sk_v6_rcv_saddr;
 231
 232         fl6.flowi6_proto = IPPROTO_TCP;
 233         fl6.daddr = sk->sk_v6_daddr;
 234         fl6.saddr = saddr ? *saddr : np->saddr;
 235         fl6.flowi6_oif = sk->sk_bound_dev_if;
 236         fl6.flowi6_mark = sk->sk_mark;
 237         fl6.fl6_dport = usin->sin6_port;
 238         fl6.fl6_sport = inet->inet_sport;
 239
 240         final_p = fl6_update_dst(&fl6, np->opt, &final);
 241
 242         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 243
 244         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 245         if (IS_ERR(dst)) {
 246                 err = PTR_ERR(dst);
 247                 goto failure;
 248         }
 249
 250         if (saddr == NULL) {
 251                 saddr = &fl6.saddr;
 252                 sk->sk_v6_rcv_saddr = *saddr;
 253         }
 254
 255         /* set the source address */
 256         np->saddr = *saddr;
 257         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 258
 259         sk->sk_gso_type = SKB_GSO_TCPV6;
 260         __ip6_dst_store(sk, dst, NULL, NULL);
 261
 262         rt = (struct rt6_info *) dst;
 263         if (tcp_death_row.sysctl_tw_recycle &&
 264             !tp->rx_opt.ts_recent_stamp &&
 265             ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
 266                 tcp_fetch_timewait_stamp(sk, dst);
 267
 268         icsk->icsk_ext_hdr_len = 0;
 269         if (np->opt)
 270                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 271                                           np->opt->opt_nflen);
 272
 273         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 274
 275         inet->inet_dport = usin->sin6_port;
 276
 277         tcp_set_state(sk, TCP_SYN_SENT);
 278         err = inet6_hash_connect(&tcp_death_row, sk);
 279         if (err)
 280                 goto late_failure;
 281
 282         ip6_set_txhash(sk);
 283
 284         if (!tp->write_seq && likely(!tp->repair))
 285                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 286                                                              sk->sk_v6_daddr.s6_addr32,
 287                                                              inet->inet_sport,
 288                                                              inet->inet_dport);
 289
 290         err = tcp_connect(sk);
 291         if (err)
 292                 goto late_failure;
 293
 294         return 0;
 295
 296 late_failure:
 297         tcp_set_state(sk, TCP_CLOSE);
 298         __sk_dst_reset(sk);
 299 failure:
 300         inet->inet_dport = 0;
 301         sk->sk_route_caps = 0;
 302         return err;
 303 }
 304
 305 static void tcp_v6_mtu_reduced(struct sock *sk)
 306 {
 307         struct dst_entry *dst;
 308
 309         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 310                 return;
 311
 312         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 313         if (!dst)
 314                 return;
 315
 316         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 317                 tcp_sync_mss(sk, dst_mtu(dst));
 318                 tcp_simple_retransmit(sk);
 319         }
 320 }
 321
 322 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 323                 u8 type, u8 code, int offset, __be32 info)
 324 {
 325         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 326         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 327         struct net *net = dev_net(skb->dev);
 328         struct request_sock *fastopen;
 329         struct ipv6_pinfo *np;
 330         struct tcp_sock *tp;
 331         __u32 seq, snd_una;
 332         struct sock *sk;
 333         int err;
 334
 335         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 336                                         &hdr->daddr, th->dest,
 337                                         &hdr->saddr, ntohs(th->source),
 338                                         skb->dev->ifindex);
 339
 340         if (!sk) {
 341                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 342                                    ICMP6_MIB_INERRORS);
 343                 return;
 344         }
 345
 346         if (sk->sk_state == TCP_TIME_WAIT) {
 347                 inet_twsk_put(inet_twsk(sk));
 348                 return;
 349         }
 350         seq = ntohl(th->seq);
 351         if (sk->sk_state == TCP_NEW_SYN_RECV)
 352                 return tcp_req_err(sk, seq);
 353
 354         bh_lock_sock(sk);
 355         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 356                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 357
 358         if (sk->sk_state == TCP_CLOSE)
 359                 goto out;
 360
 361         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 362                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 363                 goto out;
 364         }
 365
 366         tp = tcp_sk(sk);
 367         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 368         fastopen = tp->fastopen_rsk;
 369         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 370         if (sk->sk_state != TCP_LISTEN &&
 371             !between(seq, snd_una, tp->snd_nxt)) {
 372                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 373                 goto out;
 374         }
 375
 376         np = inet6_sk(sk);
 377
 378         if (type == NDISC_REDIRECT) {
 379                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 380
 381                 if (dst)
 382                         dst->ops->redirect(dst, sk, skb);
 383                 goto out;
 384         }
 385
 386         if (type == ICMPV6_PKT_TOOBIG) {
 387                 /* We are not interested in TCP_LISTEN and open_requests
 388                  * (SYN-ACKs send out by Linux are always <576bytes so
 389                  * they should go through unfragmented).
 390                  */
 391                 if (sk->sk_state == TCP_LISTEN)
 392                         goto out;
 393
 394                 if (!ip6_sk_accept_pmtu(sk))
 395                         goto out;
 396
 397                 tp->mtu_info = ntohl(info);
 398                 if (!sock_owned_by_user(sk))
 399                         tcp_v6_mtu_reduced(sk);
 400                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 401                                            &tp->tsq_flags))
 402                         sock_hold(sk);
 403                 goto out;
 404         }
 405
 406         icmpv6_err_convert(type, code, &err);
 407
 408         /* Might be for an request_sock */
 409         switch (sk->sk_state) {
 410         case TCP_SYN_SENT:
 411         case TCP_SYN_RECV:
 412                 /* Only in fast or simultaneous open. If a fast open socket is
 413                  * is already accepted it is treated as a connected one below.
 414                  */
 415                 if (fastopen && fastopen->sk == NULL)
 416                         break;
 417
 418                 if (!sock_owned_by_user(sk)) {
 419                         sk->sk_err = err;
 420                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 421
 422                         tcp_done(sk);
 423                 } else
 424                         sk->sk_err_soft = err;
 425                 goto out;
 426         }
 427
 428         if (!sock_owned_by_user(sk) && np->recverr) {
 429                 sk->sk_err = err;
 430                 sk->sk_error_report(sk);
 431         } else
 432                 sk->sk_err_soft = err;
 433
 434 out:
 435         bh_unlock_sock(sk);
 436         sock_put(sk);
 437 }
 438
 439
 440 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
 441                               struct flowi *fl,
 442                               struct request_sock *req,
 443                               u16 queue_mapping,
 444                               struct tcp_fastopen_cookie *foc)
 445 {
 446         struct inet_request_sock *ireq = inet_rsk(req);
 447         struct ipv6_pinfo *np = inet6_sk(sk);
 448         struct flowi6 *fl6 = &fl->u.ip6;
 449         struct sk_buff *skb;
 450         int err = -ENOMEM;
 451
 452         /* First, grab a route. */
 453         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
 454                 goto done;
 455
 456         skb = tcp_make_synack(sk, dst, req, foc);
 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 != NULL))
 464                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 465
 466                 skb_set_queue_mapping(skb, queue_mapping);
 467                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 468                 err = net_xmit_eval(err);
 469         }
 470
 471 done:
 472         return err;
 473 }
 474
 475
 476 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 477 {
 478         kfree_skb(inet_rsk(req)->pktopts);
 479 }
 480
 481 #ifdef CONFIG_TCP_MD5SIG
 482 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 483                                                    const struct in6_addr *addr)
 484 {
 485         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 486 }
 487
 488 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 489                                                 const struct sock *addr_sk)
 490 {
 491         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 492 }
 493
 494 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 495                                  int optlen)
 496 {
 497         struct tcp_md5sig cmd;
 498         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 499
 500         if (optlen < sizeof(cmd))
 501                 return -EINVAL;
 502
 503         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 504                 return -EFAULT;
 505
 506         if (sin6->sin6_family != AF_INET6)
 507                 return -EINVAL;
 508
 509         if (!cmd.tcpm_keylen) {
 510                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 511                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 512                                               AF_INET);
 513                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 514                                       AF_INET6);
 515         }
 516
 517         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 518                 return -EINVAL;
 519
 520         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 521                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 522                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 523
 524         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 525                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 526 }
 527
 528 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 529                                         const struct in6_addr *daddr,
 530                                         const struct in6_addr *saddr, int nbytes)
 531 {
 532         struct tcp6_pseudohdr *bp;
 533         struct scatterlist sg;
 534
 535         bp = &hp->md5_blk.ip6;
 536         /* 1. TCP pseudo-header (RFC2460) */
 537         bp->saddr = *saddr;
 538         bp->daddr = *daddr;
 539         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 540         bp->len = cpu_to_be32(nbytes);
 541
 542         sg_init_one(&sg, bp, sizeof(*bp));
 543         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 544 }
 545
 546 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 547                                const struct in6_addr *daddr, struct in6_addr *saddr,
 548                                const struct tcphdr *th)
 549 {
 550         struct tcp_md5sig_pool *hp;
 551         struct hash_desc *desc;
 552
 553         hp = tcp_get_md5sig_pool();
 554         if (!hp)
 555                 goto clear_hash_noput;
 556         desc = &hp->md5_desc;
 557
 558         if (crypto_hash_init(desc))
 559                 goto clear_hash;
 560         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 561                 goto clear_hash;
 562         if (tcp_md5_hash_header(hp, th))
 563                 goto clear_hash;
 564         if (tcp_md5_hash_key(hp, key))
 565                 goto clear_hash;
 566         if (crypto_hash_final(desc, md5_hash))
 567                 goto clear_hash;
 568
 569         tcp_put_md5sig_pool();
 570         return 0;
 571
 572 clear_hash:
 573         tcp_put_md5sig_pool();
 574 clear_hash_noput:
 575         memset(md5_hash, 0, 16);
 576         return 1;
 577 }
 578
 579 static int tcp_v6_md5_hash_skb(char *md5_hash,
 580                                const struct tcp_md5sig_key *key,
 581                                const struct sock *sk,
 582                                const struct sk_buff *skb)
 583 {
 584         const struct in6_addr *saddr, *daddr;
 585         struct tcp_md5sig_pool *hp;
 586         struct hash_desc *desc;
 587         const struct tcphdr *th = tcp_hdr(skb);
 588
 589         if (sk) { /* valid for establish/request sockets */
 590                 saddr = &sk->sk_v6_rcv_saddr;
 591                 daddr = &sk->sk_v6_daddr;
 592         } else {
 593                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 594                 saddr = &ip6h->saddr;
 595                 daddr = &ip6h->daddr;
 596         }
 597
 598         hp = tcp_get_md5sig_pool();
 599         if (!hp)
 600                 goto clear_hash_noput;
 601         desc = &hp->md5_desc;
 602
 603         if (crypto_hash_init(desc))
 604                 goto clear_hash;
 605
 606         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 607                 goto clear_hash;
 608         if (tcp_md5_hash_header(hp, th))
 609                 goto clear_hash;
 610         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 611                 goto clear_hash;
 612         if (tcp_md5_hash_key(hp, key))
 613                 goto clear_hash;
 614         if (crypto_hash_final(desc, md5_hash))
 615                 goto clear_hash;
 616
 617         tcp_put_md5sig_pool();
 618         return 0;
 619
 620 clear_hash:
 621         tcp_put_md5sig_pool();
 622 clear_hash_noput:
 623         memset(md5_hash, 0, 16);
 624         return 1;
 625 }
 626
 627 static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 628 {
 629         const __u8 *hash_location = NULL;
 630         struct tcp_md5sig_key *hash_expected;
 631         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 632         const struct tcphdr *th = tcp_hdr(skb);
 633         int genhash;
 634         u8 newhash[16];
 635
 636         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 637         hash_location = tcp_parse_md5sig_option(th);
 638
 639         /* We've parsed the options - do we have a hash? */
 640         if (!hash_expected && !hash_location)
 641                 return false;
 642
 643         if (hash_expected && !hash_location) {
 644                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 645                 return true;
 646         }
 647
 648         if (!hash_expected && hash_location) {
 649                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 650                 return true;
 651         }
 652
 653         /* check the signature */
 654         genhash = tcp_v6_md5_hash_skb(newhash,
 655                                       hash_expected,
 656                                       NULL, skb);
 657
 658         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 659                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 660                                      genhash ? "failed" : "mismatch",
 661                                      &ip6h->saddr, ntohs(th->source),
 662                                      &ip6h->daddr, ntohs(th->dest));
 663                 return true;
 664         }
 665         return false;
 666 }
 667 #endif
 668
 669 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
 670                             struct sk_buff *skb)
 671 {
 672         struct inet_request_sock *ireq = inet_rsk(req);
 673         struct ipv6_pinfo *np = inet6_sk(sk);
 674
 675         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 676         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 677
 678         /* So that link locals have meaning */
 679         if (!sk->sk_bound_dev_if &&
 680             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 681                 ireq->ir_iif = tcp_v6_iif(skb);
 682
 683         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 684             (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
 685              np->rxopt.bits.rxinfo ||
 686              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 687              np->rxopt.bits.rxohlim || np->repflow)) {
 688                 atomic_inc(&skb->users);
 689                 ireq->pktopts = skb;
 690         }
 691         ireq->ireq_family = AF_INET6;
 692 }
 693
 694 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 695                                           const struct request_sock *req,
 696                                           bool *strict)
 697 {
 698         if (strict)
 699                 *strict = true;
 700         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 701 }
 702
 703 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 704         .family         =       AF_INET6,
 705         .obj_size       =       sizeof(struct tcp6_request_sock),
 706         .rtx_syn_ack    =       tcp_rtx_synack,
 707         .send_ack       =       tcp_v6_reqsk_send_ack,
 708         .destructor     =       tcp_v6_reqsk_destructor,
 709         .send_reset     =       tcp_v6_send_reset,
 710         .syn_ack_timeout =      tcp_syn_ack_timeout,
 711 };
 712
 713 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 714         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 715                                 sizeof(struct ipv6hdr),
 716 #ifdef CONFIG_TCP_MD5SIG
 717         .req_md5_lookup =       tcp_v6_md5_lookup,
 718         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 719 #endif
 720         .init_req       =       tcp_v6_init_req,
 721 #ifdef CONFIG_SYN_COOKIES
 722         .cookie_init_seq =      cookie_v6_init_sequence,
 723 #endif
 724         .route_req      =       tcp_v6_route_req,
 725         .init_seq       =       tcp_v6_init_sequence,
 726         .send_synack    =       tcp_v6_send_synack,
 727         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 728 };
 729
 730 static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
 731                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 732                                  int oif, struct tcp_md5sig_key *key, int rst,
 733                                  u8 tclass, u32 label)
 734 {
 735         const struct tcphdr *th = tcp_hdr(skb);
 736         struct tcphdr *t1;
 737         struct sk_buff *buff;
 738         struct flowi6 fl6;
 739         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 740         struct sock *ctl_sk = net->ipv6.tcp_sk;
 741         unsigned int tot_len = sizeof(struct tcphdr);
 742         struct dst_entry *dst;
 743         __be32 *topt;
 744
 745         if (tsecr)
 746                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 747 #ifdef CONFIG_TCP_MD5SIG
 748         if (key)
 749                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 750 #endif
 751
 752         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 753                          GFP_ATOMIC);
 754         if (buff == NULL)
 755                 return;
 756
 757         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 758
 759         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 760         skb_reset_transport_header(buff);
 761
 762         /* Swap the send and the receive. */
 763         memset(t1, 0, sizeof(*t1));
 764         t1->dest = th->source;
 765         t1->source = th->dest;
 766         t1->doff = tot_len / 4;
 767         t1->seq = htonl(seq);
 768         t1->ack_seq = htonl(ack);
 769         t1->ack = !rst || !th->ack;
 770         t1->rst = rst;
 771         t1->window = htons(win);
 772
 773         topt = (__be32 *)(t1 + 1);
 774
 775         if (tsecr) {
 776                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 777                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 778                 *topt++ = htonl(tsval);
 779                 *topt++ = htonl(tsecr);
 780         }
 781
 782 #ifdef CONFIG_TCP_MD5SIG
 783         if (key) {
 784                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 785                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 786                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 787                                     &ipv6_hdr(skb)->saddr,
 788                                     &ipv6_hdr(skb)->daddr, t1);
 789         }
 790 #endif
 791
 792         memset(&fl6, 0, sizeof(fl6));
 793         fl6.daddr = ipv6_hdr(skb)->saddr;
 794         fl6.saddr = ipv6_hdr(skb)->daddr;
 795         fl6.flowlabel = label;
 796
 797         buff->ip_summed = CHECKSUM_PARTIAL;
 798         buff->csum = 0;
 799
 800         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 801
 802         fl6.flowi6_proto = IPPROTO_TCP;
 803         if (rt6_need_strict(&fl6.daddr) && !oif)
 804                 fl6.flowi6_oif = tcp_v6_iif(skb);
 805         else
 806                 fl6.flowi6_oif = oif;
 807         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 808         fl6.fl6_dport = t1->dest;
 809         fl6.fl6_sport = t1->source;
 810         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 811
 812         /* Pass a socket to ip6_dst_lookup either it is for RST
 813          * Underlying function will use this to retrieve the network
 814          * namespace
 815          */
 816         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 817         if (!IS_ERR(dst)) {
 818                 skb_dst_set(buff, dst);
 819                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 820                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 821                 if (rst)
 822                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 823                 return;
 824         }
 825
 826         kfree_skb(buff);
 827 }
 828
 829 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 830 {
 831         const struct tcphdr *th = tcp_hdr(skb);
 832         u32 seq = 0, ack_seq = 0;
 833         struct tcp_md5sig_key *key = NULL;
 834 #ifdef CONFIG_TCP_MD5SIG
 835         const __u8 *hash_location = NULL;
 836         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 837         unsigned char newhash[16];
 838         int genhash;
 839         struct sock *sk1 = NULL;
 840 #endif
 841         int oif;
 842
 843         if (th->rst)
 844                 return;
 845
 846         /* If sk not NULL, it means we did a successful lookup and incoming
 847          * route had to be correct. prequeue might have dropped our dst.
 848          */
 849         if (!sk && !ipv6_unicast_destination(skb))
 850                 return;
 851
 852 #ifdef CONFIG_TCP_MD5SIG
 853         hash_location = tcp_parse_md5sig_option(th);
 854         if (!sk && hash_location) {
 855                 /*
 856                  * active side is lost. Try to find listening socket through
 857                  * source port, and then find md5 key through listening socket.
 858                  * we are not loose security here:
 859                  * Incoming packet is checked with md5 hash with finding key,
 860                  * no RST generated if md5 hash doesn't match.
 861                  */
 862                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 863                                            &tcp_hashinfo, &ipv6h->saddr,
 864                                            th->source, &ipv6h->daddr,
 865                                            ntohs(th->source), tcp_v6_iif(skb));
 866                 if (!sk1)
 867                         return;
 868
 869                 rcu_read_lock();
 870                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 871                 if (!key)
 872                         goto release_sk1;
 873
 874                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 875                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 876                         goto release_sk1;
 877         } else {
 878                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 879         }
 880 #endif
 881
 882         if (th->ack)
 883                 seq = ntohl(th->ack_seq);
 884         else
 885                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 886                           (th->doff << 2);
 887
 888         oif = sk ? sk->sk_bound_dev_if : 0;
 889         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 890
 891 #ifdef CONFIG_TCP_MD5SIG
 892 release_sk1:
 893         if (sk1) {
 894                 rcu_read_unlock();
 895                 sock_put(sk1);
 896         }
 897 #endif
 898 }
 899
 900 static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, u32 seq,
 901                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 902                             struct tcp_md5sig_key *key, u8 tclass,
 903                             u32 label)
 904 {
 905         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 906                              tclass, label);
 907 }
 908
 909 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 910 {
 911         struct inet_timewait_sock *tw = inet_twsk(sk);
 912         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 913
 914         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 915                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 916                         tcp_time_stamp + tcptw->tw_ts_offset,
 917                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 918                         tw->tw_tclass, (tw->tw_flowlabel << 12));
 919
 920         inet_twsk_put(tw);
 921 }
 922
 923 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 924                                   struct request_sock *req)
 925 {
 926         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 927          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 928          */
 929         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 930                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 931                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 932                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 933                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 934                         0, 0);
 935 }
 936
 937
 938 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 939 {
 940         const struct tcphdr *th = tcp_hdr(skb);
 941         struct request_sock *req;
 942         struct sock *nsk;
 943
 944         /* Find possible connection requests. */
 945         req = inet6_csk_search_req(sk, th->source,
 946                                    &ipv6_hdr(skb)->saddr,
 947                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 948         if (req) {
 949                 nsk = tcp_check_req(sk, skb, req, false);
 950                 reqsk_put(req);
 951                 return nsk;
 952         }
 953         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 954                                          &ipv6_hdr(skb)->saddr, th->source,
 955                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 956                                          tcp_v6_iif(skb));
 957
 958         if (nsk) {
 959                 if (nsk->sk_state != TCP_TIME_WAIT) {
 960                         bh_lock_sock(nsk);
 961                         return nsk;
 962                 }
 963                 inet_twsk_put(inet_twsk(nsk));
 964                 return NULL;
 965         }
 966
 967 #ifdef CONFIG_SYN_COOKIES
 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         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 987         return 0; /* don't send reset */
 988 }
 989
 990 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 991                                          struct request_sock *req,
 992                                          struct dst_entry *dst)
 993 {
 994         struct inet_request_sock *ireq;
 995         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 996         struct tcp6_sock *newtcp6sk;
 997         struct inet_sock *newinet;
 998         struct tcp_sock *newtp;
 999         struct sock *newsk;
1000 #ifdef CONFIG_TCP_MD5SIG
1001         struct tcp_md5sig_key *key;
1002 #endif
1003         struct flowi6 fl6;
1004
1005         if (skb->protocol == htons(ETH_P_IP)) {
1006                 /*
1007                  *      v6 mapped
1008                  */
1009
1010                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1011
1012                 if (newsk == NULL)
1013                         return NULL;
1014
1015                 newtcp6sk = (struct tcp6_sock *)newsk;
1016                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1017
1018                 newinet = inet_sk(newsk);
1019                 newnp = inet6_sk(newsk);
1020                 newtp = tcp_sk(newsk);
1021
1022                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1023
1024                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1025
1026                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1027                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1028 #ifdef CONFIG_TCP_MD5SIG
1029                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1030 #endif
1031
1032                 newnp->ipv6_ac_list = NULL;
1033                 newnp->ipv6_fl_list = NULL;
1034                 newnp->pktoptions  = NULL;
1035                 newnp->opt         = NULL;
1036                 newnp->mcast_oif   = tcp_v6_iif(skb);
1037                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1038                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1039                 if (np->repflow)
1040                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1041
1042                 /*
1043                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1044                  * here, tcp_create_openreq_child now does this for us, see the comment in
1045                  * that function for the gory details. -acme
1046                  */
1047
1048                 /* It is tricky place. Until this moment IPv4 tcp
1049                    worked with IPv6 icsk.icsk_af_ops.
1050                    Sync it now.
1051                  */
1052                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1053
1054                 return newsk;
1055         }
1056
1057         ireq = inet_rsk(req);
1058
1059         if (sk_acceptq_is_full(sk))
1060                 goto out_overflow;
1061
1062         if (!dst) {
1063                 dst = inet6_csk_route_req(sk, &fl6, req);
1064                 if (!dst)
1065                         goto out;
1066         }
1067
1068         newsk = tcp_create_openreq_child(sk, req, skb);
1069         if (newsk == NULL)
1070                 goto out_nonewsk;
1071
1072         /*
1073          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1074          * count here, tcp_create_openreq_child now does this for us, see the
1075          * comment in that function for the gory details. -acme
1076          */
1077
1078         newsk->sk_gso_type = SKB_GSO_TCPV6;
1079         __ip6_dst_store(newsk, dst, NULL, NULL);
1080         inet6_sk_rx_dst_set(newsk, skb);
1081
1082         newtcp6sk = (struct tcp6_sock *)newsk;
1083         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1084
1085         newtp = tcp_sk(newsk);
1086         newinet = inet_sk(newsk);
1087         newnp = inet6_sk(newsk);
1088
1089         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1090
1091         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1092         newnp->saddr = ireq->ir_v6_loc_addr;
1093         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1094         newsk->sk_bound_dev_if = ireq->ir_iif;
1095
1096         ip6_set_txhash(newsk);
1097
1098         /* Now IPv6 options...
1099
1100            First: no IPv4 options.
1101          */
1102         newinet->inet_opt = NULL;
1103         newnp->ipv6_ac_list = NULL;
1104         newnp->ipv6_fl_list = NULL;
1105
1106         /* Clone RX bits */
1107         newnp->rxopt.all = np->rxopt.all;
1108
1109         /* Clone pktoptions received with SYN */
1110         newnp->pktoptions = NULL;
1111         if (ireq->pktopts != NULL) {
1112                 newnp->pktoptions = skb_clone(ireq->pktopts,
1113                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1114                 consume_skb(ireq->pktopts);
1115                 ireq->pktopts = NULL;
1116                 if (newnp->pktoptions)
1117                         skb_set_owner_r(newnp->pktoptions, newsk);
1118         }
1119         newnp->opt        = NULL;
1120         newnp->mcast_oif  = tcp_v6_iif(skb);
1121         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1122         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1123         if (np->repflow)
1124                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1125
1126         /* Clone native IPv6 options from listening socket (if any)
1127
1128            Yes, keeping reference count would be much more clever,
1129            but we make one more one thing there: reattach optmem
1130            to newsk.
1131          */
1132         if (np->opt)
1133                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1134
1135         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1136         if (newnp->opt)
1137                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1138                                                      newnp->opt->opt_flen);
1139
1140         tcp_ca_openreq_child(newsk, dst);
1141
1142         tcp_sync_mss(newsk, dst_mtu(dst));
1143         newtp->advmss = dst_metric_advmss(dst);
1144         if (tcp_sk(sk)->rx_opt.user_mss &&
1145             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1146                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1147
1148         tcp_initialize_rcv_mss(newsk);
1149
1150         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1151         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1152
1153 #ifdef CONFIG_TCP_MD5SIG
1154         /* Copy over the MD5 key from the original socket */
1155         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1156         if (key != NULL) {
1157                 /* We're using one, so create a matching key
1158                  * on the newsk structure. If we fail to get
1159                  * memory, then we end up not copying the key
1160                  * across. Shucks.
1161                  */
1162                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1163                                AF_INET6, key->key, key->keylen,
1164                                sk_gfp_atomic(sk, GFP_ATOMIC));
1165         }
1166 #endif
1167
1168         if (__inet_inherit_port(sk, newsk) < 0) {
1169                 inet_csk_prepare_forced_close(newsk);
1170                 tcp_done(newsk);
1171                 goto out;
1172         }
1173         __inet_hash(newsk, NULL);
1174
1175         return newsk;
1176
1177 out_overflow:
1178         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1179 out_nonewsk:
1180         dst_release(dst);
1181 out:
1182         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1183         return NULL;
1184 }
1185
1186 /* The socket must have it's spinlock held when we get
1187  * here.
1188  *
1189  * We have a potential double-lock case here, so even when
1190  * doing backlog processing we use the BH locking scheme.
1191  * This is because we cannot sleep with the original spinlock
1192  * held.
1193  */
1194 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1195 {
1196         struct ipv6_pinfo *np = inet6_sk(sk);
1197         struct tcp_sock *tp;
1198         struct sk_buff *opt_skb = NULL;
1199
1200         /* Imagine: socket is IPv6. IPv4 packet arrives,
1201            goes to IPv4 receive handler and backlogged.
1202            From backlog it always goes here. Kerboom...
1203            Fortunately, tcp_rcv_established and rcv_established
1204            handle them correctly, but it is not case with
1205            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1206          */
1207
1208         if (skb->protocol == htons(ETH_P_IP))
1209                 return tcp_v4_do_rcv(sk, skb);
1210
1211         if (sk_filter(sk, skb))
1212                 goto discard;
1213
1214         /*
1215          *      socket locking is here for SMP purposes as backlog rcv
1216          *      is currently called with bh processing disabled.
1217          */
1218
1219         /* Do Stevens' IPV6_PKTOPTIONS.
1220
1221            Yes, guys, it is the only place in our code, where we
1222            may make it not affecting IPv4.
1223            The rest of code is protocol independent,
1224            and I do not like idea to uglify IPv4.
1225
1226            Actually, all the idea behind IPV6_PKTOPTIONS
1227            looks not very well thought. For now we latch
1228            options, received in the last packet, enqueued
1229            by tcp. Feel free to propose better solution.
1230                                                --ANK (980728)
1231          */
1232         if (np->rxopt.all)
1233                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1234
1235         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1236                 struct dst_entry *dst = sk->sk_rx_dst;
1237
1238                 sock_rps_save_rxhash(sk, skb);
1239                 sk_mark_napi_id(sk, skb);
1240                 if (dst) {
1241                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1242                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1243                                 dst_release(dst);
1244                                 sk->sk_rx_dst = NULL;
1245                         }
1246                 }
1247
1248                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1249                 if (opt_skb)
1250                         goto ipv6_pktoptions;
1251                 return 0;
1252         }
1253
1254         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1255                 goto csum_err;
1256
1257         if (sk->sk_state == TCP_LISTEN) {
1258                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1259                 if (!nsk)
1260                         goto discard;
1261
1262                 /*
1263                  * Queue it on the new socket if the new socket is active,
1264                  * otherwise we just shortcircuit this and continue with
1265                  * the new socket..
1266                  */
1267                 if (nsk != sk) {
1268                         sock_rps_save_rxhash(nsk, skb);
1269                         sk_mark_napi_id(sk, skb);
1270                         if (tcp_child_process(sk, nsk, skb))
1271                                 goto reset;
1272                         if (opt_skb)
1273                                 __kfree_skb(opt_skb);
1274                         return 0;
1275                 }
1276         } else
1277                 sock_rps_save_rxhash(sk, skb);
1278
1279         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1280                 goto reset;
1281         if (opt_skb)
1282                 goto ipv6_pktoptions;
1283         return 0;
1284
1285 reset:
1286         tcp_v6_send_reset(sk, skb);
1287 discard:
1288         if (opt_skb)
1289                 __kfree_skb(opt_skb);
1290         kfree_skb(skb);
1291         return 0;
1292 csum_err:
1293         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1294         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1295         goto discard;
1296
1297
1298 ipv6_pktoptions:
1299         /* Do you ask, what is it?
1300
1301            1. skb was enqueued by tcp.
1302            2. skb is added to tail of read queue, rather than out of order.
1303            3. socket is not in passive state.
1304            4. Finally, it really contains options, which user wants to receive.
1305          */
1306         tp = tcp_sk(sk);
1307         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1308             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1309                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1310                         np->mcast_oif = tcp_v6_iif(opt_skb);
1311                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1312                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1313                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1314                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1315                 if (np->repflow)
1316                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1317                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1318                         skb_set_owner_r(opt_skb, sk);
1319                         opt_skb = xchg(&np->pktoptions, opt_skb);
1320                 } else {
1321                         __kfree_skb(opt_skb);
1322                         opt_skb = xchg(&np->pktoptions, NULL);
1323                 }
1324         }
1325
1326         kfree_skb(opt_skb);
1327         return 0;
1328 }
1329
1330 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1331                            const struct tcphdr *th)
1332 {
1333         /* This is tricky: we move IP6CB at its correct location into
1334          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1335          * _decode_session6() uses IP6CB().
1336          * barrier() makes sure compiler won't play aliasing games.
1337          */
1338         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1339                 sizeof(struct inet6_skb_parm));
1340         barrier();
1341
1342         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1343         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1344                                     skb->len - th->doff*4);
1345         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1346         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1347         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1348         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1349         TCP_SKB_CB(skb)->sacked = 0;
1350 }
1351
1352 static int tcp_v6_rcv(struct sk_buff *skb)
1353 {
1354         const struct tcphdr *th;
1355         const struct ipv6hdr *hdr;
1356         struct sock *sk;
1357         int ret;
1358         struct net *net = dev_net(skb->dev);
1359
1360         if (skb->pkt_type != PACKET_HOST)
1361                 goto discard_it;
1362
1363         /*
1364          *      Count it even if it's bad.
1365          */
1366         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1367
1368         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1369                 goto discard_it;
1370
1371         th = tcp_hdr(skb);
1372
1373         if (th->doff < sizeof(struct tcphdr)/4)
1374                 goto bad_packet;
1375         if (!pskb_may_pull(skb, th->doff*4))
1376                 goto discard_it;
1377
1378         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1379                 goto csum_error;
1380
1381         th = tcp_hdr(skb);
1382         hdr = ipv6_hdr(skb);
1383
1384         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1385                                 inet6_iif(skb));
1386         if (!sk)
1387                 goto no_tcp_socket;
1388
1389 process:
1390         if (sk->sk_state == TCP_TIME_WAIT)
1391                 goto do_time_wait;
1392
1393         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1394                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1395                 goto discard_and_relse;
1396         }
1397
1398         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1399                 goto discard_and_relse;
1400
1401         tcp_v6_fill_cb(skb, hdr, th);
1402
1403 #ifdef CONFIG_TCP_MD5SIG
1404         if (tcp_v6_inbound_md5_hash(sk, skb))
1405                 goto discard_and_relse;
1406 #endif
1407
1408         if (sk_filter(sk, skb))
1409                 goto discard_and_relse;
1410
1411         sk_incoming_cpu_update(sk);
1412         skb->dev = NULL;
1413
1414         bh_lock_sock_nested(sk);
1415         ret = 0;
1416         if (!sock_owned_by_user(sk)) {
1417                 if (!tcp_prequeue(sk, skb))
1418                         ret = tcp_v6_do_rcv(sk, skb);
1419         } else if (unlikely(sk_add_backlog(sk, skb,
1420                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1421                 bh_unlock_sock(sk);
1422                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1423                 goto discard_and_relse;
1424         }
1425         bh_unlock_sock(sk);
1426
1427         sock_put(sk);
1428         return ret ? -1 : 0;
1429
1430 no_tcp_socket:
1431         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1432                 goto discard_it;
1433
1434         tcp_v6_fill_cb(skb, hdr, th);
1435
1436         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1437 csum_error:
1438                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1439 bad_packet:
1440                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1441         } else {
1442                 tcp_v6_send_reset(NULL, skb);
1443         }
1444
1445 discard_it:
1446         kfree_skb(skb);
1447         return 0;
1448
1449 discard_and_relse:
1450         sock_put(sk);
1451         goto discard_it;
1452
1453 do_time_wait:
1454         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1455                 inet_twsk_put(inet_twsk(sk));
1456                 goto discard_it;
1457         }
1458
1459         tcp_v6_fill_cb(skb, hdr, th);
1460
1461         if (skb->len < (th->doff<<2)) {
1462                 inet_twsk_put(inet_twsk(sk));
1463                 goto bad_packet;
1464         }
1465         if (tcp_checksum_complete(skb)) {
1466                 inet_twsk_put(inet_twsk(sk));
1467                 goto csum_error;
1468         }
1469
1470         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1471         case TCP_TW_SYN:
1472         {
1473                 struct sock *sk2;
1474
1475                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1476                                             &ipv6_hdr(skb)->saddr, th->source,
1477                                             &ipv6_hdr(skb)->daddr,
1478                                             ntohs(th->dest), tcp_v6_iif(skb));
1479                 if (sk2 != NULL) {
1480                         struct inet_timewait_sock *tw = inet_twsk(sk);
1481                         inet_twsk_deschedule(tw, &tcp_death_row);
1482                         inet_twsk_put(tw);
1483                         sk = sk2;
1484                         goto process;
1485                 }
1486                 /* Fall through to ACK */
1487         }
1488         case TCP_TW_ACK:
1489                 tcp_v6_timewait_ack(sk, skb);
1490                 break;
1491         case TCP_TW_RST:
1492                 goto no_tcp_socket;
1493         case TCP_TW_SUCCESS:
1494                 ;
1495         }
1496         goto discard_it;
1497 }
1498
1499 static void tcp_v6_early_demux(struct sk_buff *skb)
1500 {
1501         const struct ipv6hdr *hdr;
1502         const struct tcphdr *th;
1503         struct sock *sk;
1504
1505         if (skb->pkt_type != PACKET_HOST)
1506                 return;
1507
1508         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1509                 return;
1510
1511         hdr = ipv6_hdr(skb);
1512         th = tcp_hdr(skb);
1513
1514         if (th->doff < sizeof(struct tcphdr) / 4)
1515                 return;
1516
1517         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1518         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1519                                         &hdr->saddr, th->source,
1520                                         &hdr->daddr, ntohs(th->dest),
1521                                         inet6_iif(skb));
1522         if (sk) {
1523                 skb->sk = sk;
1524                 skb->destructor = sock_edemux;
1525                 if (sk_fullsock(sk)) {
1526                         struct dst_entry *dst = sk->sk_rx_dst;
1527
1528                         if (dst)
1529                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1530                         if (dst &&
1531                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1532                                 skb_dst_set_noref(skb, dst);
1533                 }
1534         }
1535 }
1536
1537 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1538         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1539         .twsk_unique    = tcp_twsk_unique,
1540         .twsk_destructor = tcp_twsk_destructor,
1541 };
1542
1543 static const struct inet_connection_sock_af_ops ipv6_specific = {
1544         .queue_xmit        = inet6_csk_xmit,
1545         .send_check        = tcp_v6_send_check,
1546         .rebuild_header    = inet6_sk_rebuild_header,
1547         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1548         .conn_request      = tcp_v6_conn_request,
1549         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1550         .net_header_len    = sizeof(struct ipv6hdr),
1551         .net_frag_header_len = sizeof(struct frag_hdr),
1552         .setsockopt        = ipv6_setsockopt,
1553         .getsockopt        = ipv6_getsockopt,
1554         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1555         .sockaddr_len      = sizeof(struct sockaddr_in6),
1556         .bind_conflict     = inet6_csk_bind_conflict,
1557 #ifdef CONFIG_COMPAT
1558         .compat_setsockopt = compat_ipv6_setsockopt,
1559         .compat_getsockopt = compat_ipv6_getsockopt,
1560 #endif
1561         .mtu_reduced       = tcp_v6_mtu_reduced,
1562 };
1563
1564 #ifdef CONFIG_TCP_MD5SIG
1565 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1566         .md5_lookup     =       tcp_v6_md5_lookup,
1567         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1568         .md5_parse      =       tcp_v6_parse_md5_keys,
1569 };
1570 #endif
1571
1572 /*
1573  *      TCP over IPv4 via INET6 API
1574  */
1575 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1576         .queue_xmit        = ip_queue_xmit,
1577         .send_check        = tcp_v4_send_check,
1578         .rebuild_header    = inet_sk_rebuild_header,
1579         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1580         .conn_request      = tcp_v6_conn_request,
1581         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1582         .net_header_len    = sizeof(struct iphdr),
1583         .setsockopt        = ipv6_setsockopt,
1584         .getsockopt        = ipv6_getsockopt,
1585         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1586         .sockaddr_len      = sizeof(struct sockaddr_in6),
1587         .bind_conflict     = inet6_csk_bind_conflict,
1588 #ifdef CONFIG_COMPAT
1589         .compat_setsockopt = compat_ipv6_setsockopt,
1590         .compat_getsockopt = compat_ipv6_getsockopt,
1591 #endif
1592         .mtu_reduced       = tcp_v4_mtu_reduced,
1593 };
1594
1595 #ifdef CONFIG_TCP_MD5SIG
1596 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1597         .md5_lookup     =       tcp_v4_md5_lookup,
1598         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1599         .md5_parse      =       tcp_v6_parse_md5_keys,
1600 };
1601 #endif
1602
1603 /* NOTE: A lot of things set to zero explicitly by call to
1604  *       sk_alloc() so need not be done here.
1605  */
1606 static int tcp_v6_init_sock(struct sock *sk)
1607 {
1608         struct inet_connection_sock *icsk = inet_csk(sk);
1609
1610         tcp_init_sock(sk);
1611
1612         icsk->icsk_af_ops = &ipv6_specific;
1613
1614 #ifdef CONFIG_TCP_MD5SIG
1615         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1616 #endif
1617
1618         return 0;
1619 }
1620
1621 static void tcp_v6_destroy_sock(struct sock *sk)
1622 {
1623         tcp_v4_destroy_sock(sk);
1624         inet6_destroy_sock(sk);
1625 }
1626
1627 #ifdef CONFIG_PROC_FS
1628 /* Proc filesystem TCPv6 sock list dumping. */
1629 static void get_openreq6(struct seq_file *seq,
1630                          struct request_sock *req, int i, kuid_t uid)
1631 {
1632         long ttd = req->rsk_timer.expires - jiffies;
1633         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1634         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1635
1636         if (ttd < 0)
1637                 ttd = 0;
1638
1639         seq_printf(seq,
1640                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1641                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1642                    i,
1643                    src->s6_addr32[0], src->s6_addr32[1],
1644                    src->s6_addr32[2], src->s6_addr32[3],
1645                    inet_rsk(req)->ir_num,
1646                    dest->s6_addr32[0], dest->s6_addr32[1],
1647                    dest->s6_addr32[2], dest->s6_addr32[3],
1648                    ntohs(inet_rsk(req)->ir_rmt_port),
1649                    TCP_SYN_RECV,
1650                    0, 0, /* could print option size, but that is af dependent. */
1651                    1,   /* timers active (only the expire timer) */
1652                    jiffies_to_clock_t(ttd),
1653                    req->num_timeout,
1654                    from_kuid_munged(seq_user_ns(seq), uid),
1655                    0,  /* non standard timer */
1656                    0, /* open_requests have no inode */
1657                    0, req);
1658 }
1659
1660 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1661 {
1662         const struct in6_addr *dest, *src;
1663         __u16 destp, srcp;
1664         int timer_active;
1665         unsigned long timer_expires;
1666         const struct inet_sock *inet = inet_sk(sp);
1667         const struct tcp_sock *tp = tcp_sk(sp);
1668         const struct inet_connection_sock *icsk = inet_csk(sp);
1669         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1670
1671         dest  = &sp->sk_v6_daddr;
1672         src   = &sp->sk_v6_rcv_saddr;
1673         destp = ntohs(inet->inet_dport);
1674         srcp  = ntohs(inet->inet_sport);
1675
1676         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1677                 timer_active    = 1;
1678                 timer_expires   = icsk->icsk_timeout;
1679         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1680                 timer_active    = 4;
1681                 timer_expires   = icsk->icsk_timeout;
1682         } else if (timer_pending(&sp->sk_timer)) {
1683                 timer_active    = 2;
1684                 timer_expires   = sp->sk_timer.expires;
1685         } else {
1686                 timer_active    = 0;
1687                 timer_expires = jiffies;
1688         }
1689
1690         seq_printf(seq,
1691                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1692                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1693                    i,
1694                    src->s6_addr32[0], src->s6_addr32[1],
1695                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1696                    dest->s6_addr32[0], dest->s6_addr32[1],
1697                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1698                    sp->sk_state,
1699                    tp->write_seq-tp->snd_una,
1700                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1701                    timer_active,
1702                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1703                    icsk->icsk_retransmits,
1704                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1705                    icsk->icsk_probes_out,
1706                    sock_i_ino(sp),
1707                    atomic_read(&sp->sk_refcnt), sp,
1708                    jiffies_to_clock_t(icsk->icsk_rto),
1709                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1710                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1711                    tp->snd_cwnd,
1712                    sp->sk_state == TCP_LISTEN ?
1713                         (fastopenq ? fastopenq->max_qlen : 0) :
1714                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1715                    );
1716 }
1717
1718 static void get_timewait6_sock(struct seq_file *seq,
1719                                struct inet_timewait_sock *tw, int i)
1720 {
1721         const struct in6_addr *dest, *src;
1722         __u16 destp, srcp;
1723         s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1724
1725         dest = &tw->tw_v6_daddr;
1726         src  = &tw->tw_v6_rcv_saddr;
1727         destp = ntohs(tw->tw_dport);
1728         srcp  = ntohs(tw->tw_sport);
1729
1730         seq_printf(seq,
1731                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1732                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1733                    i,
1734                    src->s6_addr32[0], src->s6_addr32[1],
1735                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1736                    dest->s6_addr32[0], dest->s6_addr32[1],
1737                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1738                    tw->tw_substate, 0, 0,
1739                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1740                    atomic_read(&tw->tw_refcnt), tw);
1741 }
1742
1743 static int tcp6_seq_show(struct seq_file *seq, void *v)
1744 {
1745         struct tcp_iter_state *st;
1746         struct sock *sk = v;
1747
1748         if (v == SEQ_START_TOKEN) {
1749                 seq_puts(seq,
1750                          "  sl  "
1751                          "local_address                         "
1752                          "remote_address                        "
1753                          "st tx_queue rx_queue tr tm->when retrnsmt"
1754                          "   uid  timeout inode\n");
1755                 goto out;
1756         }
1757         st = seq->private;
1758
1759         switch (st->state) {
1760         case TCP_SEQ_STATE_LISTENING:
1761         case TCP_SEQ_STATE_ESTABLISHED:
1762                 if (sk->sk_state == TCP_TIME_WAIT)
1763                         get_timewait6_sock(seq, v, st->num);
1764                 else
1765                         get_tcp6_sock(seq, v, st->num);
1766                 break;
1767         case TCP_SEQ_STATE_OPENREQ:
1768                 get_openreq6(seq, v, st->num, st->uid);
1769                 break;
1770         }
1771 out:
1772         return 0;
1773 }
1774
1775 static const struct file_operations tcp6_afinfo_seq_fops = {
1776         .owner   = THIS_MODULE,
1777         .open    = tcp_seq_open,
1778         .read    = seq_read,
1779         .llseek  = seq_lseek,
1780         .release = seq_release_net
1781 };
1782
1783 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1784         .name           = "tcp6",
1785         .family         = AF_INET6,
1786         .seq_fops       = &tcp6_afinfo_seq_fops,
1787         .seq_ops        = {
1788                 .show           = tcp6_seq_show,
1789         },
1790 };
1791
1792 int __net_init tcp6_proc_init(struct net *net)
1793 {
1794         return tcp_proc_register(net, &tcp6_seq_afinfo);
1795 }
1796
1797 void tcp6_proc_exit(struct net *net)
1798 {
1799         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1800 }
1801 #endif
1802
1803 static void tcp_v6_clear_sk(struct sock *sk, int size)
1804 {
1805         struct inet_sock *inet = inet_sk(sk);
1806
1807         /* we do not want to clear pinet6 field, because of RCU lookups */
1808         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1809
1810         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1811         memset(&inet->pinet6 + 1, 0, size);
1812 }
1813
1814 struct proto tcpv6_prot = {
1815         .name                   = "TCPv6",
1816         .owner                  = THIS_MODULE,
1817         .close                  = tcp_close,
1818         .connect                = tcp_v6_connect,
1819         .disconnect             = tcp_disconnect,
1820         .accept                 = inet_csk_accept,
1821         .ioctl                  = tcp_ioctl,
1822         .init                   = tcp_v6_init_sock,
1823         .destroy                = tcp_v6_destroy_sock,
1824         .shutdown               = tcp_shutdown,
1825         .setsockopt             = tcp_setsockopt,
1826         .getsockopt             = tcp_getsockopt,
1827         .recvmsg                = tcp_recvmsg,
1828         .sendmsg                = tcp_sendmsg,
1829         .sendpage               = tcp_sendpage,
1830         .backlog_rcv            = tcp_v6_do_rcv,
1831         .release_cb             = tcp_release_cb,
1832         .hash                   = inet_hash,
1833         .unhash                 = inet_unhash,
1834         .get_port               = inet_csk_get_port,
1835         .enter_memory_pressure  = tcp_enter_memory_pressure,
1836         .stream_memory_free     = tcp_stream_memory_free,
1837         .sockets_allocated      = &tcp_sockets_allocated,
1838         .memory_allocated       = &tcp_memory_allocated,
1839         .memory_pressure        = &tcp_memory_pressure,
1840         .orphan_count           = &tcp_orphan_count,
1841         .sysctl_mem             = sysctl_tcp_mem,
1842         .sysctl_wmem            = sysctl_tcp_wmem,
1843         .sysctl_rmem            = sysctl_tcp_rmem,
1844         .max_header             = MAX_TCP_HEADER,
1845         .obj_size               = sizeof(struct tcp6_sock),
1846         .slab_flags             = SLAB_DESTROY_BY_RCU,
1847         .twsk_prot              = &tcp6_timewait_sock_ops,
1848         .rsk_prot               = &tcp6_request_sock_ops,
1849         .h.hashinfo             = &tcp_hashinfo,
1850         .no_autobind            = true,
1851 #ifdef CONFIG_COMPAT
1852         .compat_setsockopt      = compat_tcp_setsockopt,
1853         .compat_getsockopt      = compat_tcp_getsockopt,
1854 #endif
1855 #ifdef CONFIG_MEMCG_KMEM
1856         .proto_cgroup           = tcp_proto_cgroup,
1857 #endif
1858         .clear_sk               = tcp_v6_clear_sk,
1859 };
1860
1861 static const struct inet6_protocol tcpv6_protocol = {
1862         .early_demux    =       tcp_v6_early_demux,
1863         .handler        =       tcp_v6_rcv,
1864         .err_handler    =       tcp_v6_err,
1865         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1866 };
1867
1868 static struct inet_protosw tcpv6_protosw = {
1869         .type           =       SOCK_STREAM,
1870         .protocol       =       IPPROTO_TCP,
1871         .prot           =       &tcpv6_prot,
1872         .ops            =       &inet6_stream_ops,
1873         .flags          =       INET_PROTOSW_PERMANENT |
1874                                 INET_PROTOSW_ICSK,
1875 };
1876
1877 static int __net_init tcpv6_net_init(struct net *net)
1878 {
1879         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1880                                     SOCK_RAW, IPPROTO_TCP, net);
1881 }
1882
1883 static void __net_exit tcpv6_net_exit(struct net *net)
1884 {
1885         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1886 }
1887
1888 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1889 {
1890         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1891 }
1892
1893 static struct pernet_operations tcpv6_net_ops = {
1894         .init       = tcpv6_net_init,
1895         .exit       = tcpv6_net_exit,
1896         .exit_batch = tcpv6_net_exit_batch,
1897 };
1898
1899 int __init tcpv6_init(void)
1900 {
1901         int ret;
1902
1903         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1904         if (ret)
1905                 goto out;
1906
1907         /* register inet6 protocol */
1908         ret = inet6_register_protosw(&tcpv6_protosw);
1909         if (ret)
1910                 goto out_tcpv6_protocol;
1911
1912         ret = register_pernet_subsys(&tcpv6_net_ops);
1913         if (ret)
1914                 goto out_tcpv6_protosw;
1915 out:
1916         return ret;
1917
1918 out_tcpv6_protosw:
1919         inet6_unregister_protosw(&tcpv6_protosw);
1920 out_tcpv6_protocol:
1921         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1922         goto out;
1923 }
1924
1925 void tcpv6_exit(void)
1926 {
1927         unregister_pernet_subsys(&tcpv6_net_ops);
1928         inet6_unregister_protosw(&tcpv6_protosw);
1929         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1930 }