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                                                 struct sock *addr_sk)
 490 {
 491         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 492 }
 493
 494 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 495                                                       struct request_sock *req)
 496 {
 497         return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
 498 }
 499
 500 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 501                                  int optlen)
 502 {
 503         struct tcp_md5sig cmd;
 504         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 505
 506         if (optlen < sizeof(cmd))
 507                 return -EINVAL;
 508
 509         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 510                 return -EFAULT;
 511
 512         if (sin6->sin6_family != AF_INET6)
 513                 return -EINVAL;
 514
 515         if (!cmd.tcpm_keylen) {
 516                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 517                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 518                                               AF_INET);
 519                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 520                                       AF_INET6);
 521         }
 522
 523         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 524                 return -EINVAL;
 525
 526         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 527                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 528                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 529
 530         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 531                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 532 }
 533
 534 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 535                                         const struct in6_addr *daddr,
 536                                         const struct in6_addr *saddr, int nbytes)
 537 {
 538         struct tcp6_pseudohdr *bp;
 539         struct scatterlist sg;
 540
 541         bp = &hp->md5_blk.ip6;
 542         /* 1. TCP pseudo-header (RFC2460) */
 543         bp->saddr = *saddr;
 544         bp->daddr = *daddr;
 545         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 546         bp->len = cpu_to_be32(nbytes);
 547
 548         sg_init_one(&sg, bp, sizeof(*bp));
 549         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 550 }
 551
 552 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 553                                const struct in6_addr *daddr, struct in6_addr *saddr,
 554                                const struct tcphdr *th)
 555 {
 556         struct tcp_md5sig_pool *hp;
 557         struct hash_desc *desc;
 558
 559         hp = tcp_get_md5sig_pool();
 560         if (!hp)
 561                 goto clear_hash_noput;
 562         desc = &hp->md5_desc;
 563
 564         if (crypto_hash_init(desc))
 565                 goto clear_hash;
 566         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 567                 goto clear_hash;
 568         if (tcp_md5_hash_header(hp, th))
 569                 goto clear_hash;
 570         if (tcp_md5_hash_key(hp, key))
 571                 goto clear_hash;
 572         if (crypto_hash_final(desc, md5_hash))
 573                 goto clear_hash;
 574
 575         tcp_put_md5sig_pool();
 576         return 0;
 577
 578 clear_hash:
 579         tcp_put_md5sig_pool();
 580 clear_hash_noput:
 581         memset(md5_hash, 0, 16);
 582         return 1;
 583 }
 584
 585 static int tcp_v6_md5_hash_skb(char *md5_hash,
 586                                const struct tcp_md5sig_key *key,
 587                                const struct sock *sk,
 588                                const struct sk_buff *skb)
 589 {
 590         const struct in6_addr *saddr, *daddr;
 591         struct tcp_md5sig_pool *hp;
 592         struct hash_desc *desc;
 593         const struct tcphdr *th = tcp_hdr(skb);
 594
 595         if (sk) { /* valid for establish/request sockets */
 596                 saddr = &sk->sk_v6_rcv_saddr;
 597                 daddr = &sk->sk_v6_daddr;
 598         } else {
 599                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 600                 saddr = &ip6h->saddr;
 601                 daddr = &ip6h->daddr;
 602         }
 603
 604         hp = tcp_get_md5sig_pool();
 605         if (!hp)
 606                 goto clear_hash_noput;
 607         desc = &hp->md5_desc;
 608
 609         if (crypto_hash_init(desc))
 610                 goto clear_hash;
 611
 612         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 613                 goto clear_hash;
 614         if (tcp_md5_hash_header(hp, th))
 615                 goto clear_hash;
 616         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 617                 goto clear_hash;
 618         if (tcp_md5_hash_key(hp, key))
 619                 goto clear_hash;
 620         if (crypto_hash_final(desc, md5_hash))
 621                 goto clear_hash;
 622
 623         tcp_put_md5sig_pool();
 624         return 0;
 625
 626 clear_hash:
 627         tcp_put_md5sig_pool();
 628 clear_hash_noput:
 629         memset(md5_hash, 0, 16);
 630         return 1;
 631 }
 632
 633 static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 634 {
 635         const __u8 *hash_location = NULL;
 636         struct tcp_md5sig_key *hash_expected;
 637         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 638         const struct tcphdr *th = tcp_hdr(skb);
 639         int genhash;
 640         u8 newhash[16];
 641
 642         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 643         hash_location = tcp_parse_md5sig_option(th);
 644
 645         /* We've parsed the options - do we have a hash? */
 646         if (!hash_expected && !hash_location)
 647                 return false;
 648
 649         if (hash_expected && !hash_location) {
 650                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 651                 return true;
 652         }
 653
 654         if (!hash_expected && hash_location) {
 655                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 656                 return true;
 657         }
 658
 659         /* check the signature */
 660         genhash = tcp_v6_md5_hash_skb(newhash,
 661                                       hash_expected,
 662                                       NULL, skb);
 663
 664         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 665                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 666                                      genhash ? "failed" : "mismatch",
 667                                      &ip6h->saddr, ntohs(th->source),
 668                                      &ip6h->daddr, ntohs(th->dest));
 669                 return true;
 670         }
 671         return false;
 672 }
 673 #endif
 674
 675 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
 676                             struct sk_buff *skb)
 677 {
 678         struct inet_request_sock *ireq = inet_rsk(req);
 679         struct ipv6_pinfo *np = inet6_sk(sk);
 680
 681         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 682         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 683
 684         /* So that link locals have meaning */
 685         if (!sk->sk_bound_dev_if &&
 686             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 687                 ireq->ir_iif = tcp_v6_iif(skb);
 688
 689         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 690             (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
 691              np->rxopt.bits.rxinfo ||
 692              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 693              np->rxopt.bits.rxohlim || np->repflow)) {
 694                 atomic_inc(&skb->users);
 695                 ireq->pktopts = skb;
 696         }
 697         ireq->ireq_family = AF_INET6;
 698 }
 699
 700 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 701                                           const struct request_sock *req,
 702                                           bool *strict)
 703 {
 704         if (strict)
 705                 *strict = true;
 706         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 707 }
 708
 709 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 710         .family         =       AF_INET6,
 711         .obj_size       =       sizeof(struct tcp6_request_sock),
 712         .rtx_syn_ack    =       tcp_rtx_synack,
 713         .send_ack       =       tcp_v6_reqsk_send_ack,
 714         .destructor     =       tcp_v6_reqsk_destructor,
 715         .send_reset     =       tcp_v6_send_reset,
 716         .syn_ack_timeout =      tcp_syn_ack_timeout,
 717 };
 718
 719 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 720         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 721                                 sizeof(struct ipv6hdr),
 722 #ifdef CONFIG_TCP_MD5SIG
 723         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 724         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 725 #endif
 726         .init_req       =       tcp_v6_init_req,
 727 #ifdef CONFIG_SYN_COOKIES
 728         .cookie_init_seq =      cookie_v6_init_sequence,
 729 #endif
 730         .route_req      =       tcp_v6_route_req,
 731         .init_seq       =       tcp_v6_init_sequence,
 732         .send_synack    =       tcp_v6_send_synack,
 733         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 734 };
 735
 736 static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
 737                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 738                                  int oif, struct tcp_md5sig_key *key, int rst,
 739                                  u8 tclass, u32 label)
 740 {
 741         const struct tcphdr *th = tcp_hdr(skb);
 742         struct tcphdr *t1;
 743         struct sk_buff *buff;
 744         struct flowi6 fl6;
 745         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 746         struct sock *ctl_sk = net->ipv6.tcp_sk;
 747         unsigned int tot_len = sizeof(struct tcphdr);
 748         struct dst_entry *dst;
 749         __be32 *topt;
 750
 751         if (tsecr)
 752                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 753 #ifdef CONFIG_TCP_MD5SIG
 754         if (key)
 755                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 756 #endif
 757
 758         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 759                          GFP_ATOMIC);
 760         if (buff == NULL)
 761                 return;
 762
 763         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 764
 765         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 766         skb_reset_transport_header(buff);
 767
 768         /* Swap the send and the receive. */
 769         memset(t1, 0, sizeof(*t1));
 770         t1->dest = th->source;
 771         t1->source = th->dest;
 772         t1->doff = tot_len / 4;
 773         t1->seq = htonl(seq);
 774         t1->ack_seq = htonl(ack);
 775         t1->ack = !rst || !th->ack;
 776         t1->rst = rst;
 777         t1->window = htons(win);
 778
 779         topt = (__be32 *)(t1 + 1);
 780
 781         if (tsecr) {
 782                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 783                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 784                 *topt++ = htonl(tsval);
 785                 *topt++ = htonl(tsecr);
 786         }
 787
 788 #ifdef CONFIG_TCP_MD5SIG
 789         if (key) {
 790                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 791                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 792                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 793                                     &ipv6_hdr(skb)->saddr,
 794                                     &ipv6_hdr(skb)->daddr, t1);
 795         }
 796 #endif
 797
 798         memset(&fl6, 0, sizeof(fl6));
 799         fl6.daddr = ipv6_hdr(skb)->saddr;
 800         fl6.saddr = ipv6_hdr(skb)->daddr;
 801         fl6.flowlabel = label;
 802
 803         buff->ip_summed = CHECKSUM_PARTIAL;
 804         buff->csum = 0;
 805
 806         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 807
 808         fl6.flowi6_proto = IPPROTO_TCP;
 809         if (rt6_need_strict(&fl6.daddr) && !oif)
 810                 fl6.flowi6_oif = tcp_v6_iif(skb);
 811         else
 812                 fl6.flowi6_oif = oif;
 813         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 814         fl6.fl6_dport = t1->dest;
 815         fl6.fl6_sport = t1->source;
 816         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 817
 818         /* Pass a socket to ip6_dst_lookup either it is for RST
 819          * Underlying function will use this to retrieve the network
 820          * namespace
 821          */
 822         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 823         if (!IS_ERR(dst)) {
 824                 skb_dst_set(buff, dst);
 825                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 826                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 827                 if (rst)
 828                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 829                 return;
 830         }
 831
 832         kfree_skb(buff);
 833 }
 834
 835 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 836 {
 837         const struct tcphdr *th = tcp_hdr(skb);
 838         u32 seq = 0, ack_seq = 0;
 839         struct tcp_md5sig_key *key = NULL;
 840 #ifdef CONFIG_TCP_MD5SIG
 841         const __u8 *hash_location = NULL;
 842         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 843         unsigned char newhash[16];
 844         int genhash;
 845         struct sock *sk1 = NULL;
 846 #endif
 847         int oif;
 848
 849         if (th->rst)
 850                 return;
 851
 852         /* If sk not NULL, it means we did a successful lookup and incoming
 853          * route had to be correct. prequeue might have dropped our dst.
 854          */
 855         if (!sk && !ipv6_unicast_destination(skb))
 856                 return;
 857
 858 #ifdef CONFIG_TCP_MD5SIG
 859         hash_location = tcp_parse_md5sig_option(th);
 860         if (!sk && hash_location) {
 861                 /*
 862                  * active side is lost. Try to find listening socket through
 863                  * source port, and then find md5 key through listening socket.
 864                  * we are not loose security here:
 865                  * Incoming packet is checked with md5 hash with finding key,
 866                  * no RST generated if md5 hash doesn't match.
 867                  */
 868                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 869                                            &tcp_hashinfo, &ipv6h->saddr,
 870                                            th->source, &ipv6h->daddr,
 871                                            ntohs(th->source), tcp_v6_iif(skb));
 872                 if (!sk1)
 873                         return;
 874
 875                 rcu_read_lock();
 876                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 877                 if (!key)
 878                         goto release_sk1;
 879
 880                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 881                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 882                         goto release_sk1;
 883         } else {
 884                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 885         }
 886 #endif
 887
 888         if (th->ack)
 889                 seq = ntohl(th->ack_seq);
 890         else
 891                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 892                           (th->doff << 2);
 893
 894         oif = sk ? sk->sk_bound_dev_if : 0;
 895         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 896
 897 #ifdef CONFIG_TCP_MD5SIG
 898 release_sk1:
 899         if (sk1) {
 900                 rcu_read_unlock();
 901                 sock_put(sk1);
 902         }
 903 #endif
 904 }
 905
 906 static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, u32 seq,
 907                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 908                             struct tcp_md5sig_key *key, u8 tclass,
 909                             u32 label)
 910 {
 911         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 912                              tclass, label);
 913 }
 914
 915 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 916 {
 917         struct inet_timewait_sock *tw = inet_twsk(sk);
 918         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 919
 920         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 921                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 922                         tcp_time_stamp + tcptw->tw_ts_offset,
 923                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 924                         tw->tw_tclass, (tw->tw_flowlabel << 12));
 925
 926         inet_twsk_put(tw);
 927 }
 928
 929 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 930                                   struct request_sock *req)
 931 {
 932         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 933          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 934          */
 935         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 936                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 937                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 938                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 939                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 940                         0, 0);
 941 }
 942
 943
 944 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 945 {
 946         const struct tcphdr *th = tcp_hdr(skb);
 947         struct request_sock *req;
 948         struct sock *nsk;
 949
 950         /* Find possible connection requests. */
 951         req = inet6_csk_search_req(sk, th->source,
 952                                    &ipv6_hdr(skb)->saddr,
 953                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 954         if (req) {
 955                 nsk = tcp_check_req(sk, skb, req, false);
 956                 reqsk_put(req);
 957                 return nsk;
 958         }
 959         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 960                                          &ipv6_hdr(skb)->saddr, th->source,
 961                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 962                                          tcp_v6_iif(skb));
 963
 964         if (nsk) {
 965                 if (nsk->sk_state != TCP_TIME_WAIT) {
 966                         bh_lock_sock(nsk);
 967                         return nsk;
 968                 }
 969                 inet_twsk_put(inet_twsk(nsk));
 970                 return NULL;
 971         }
 972
 973 #ifdef CONFIG_SYN_COOKIES
 974         if (!th->syn)
 975                 sk = cookie_v6_check(sk, skb);
 976 #endif
 977         return sk;
 978 }
 979
 980 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 981 {
 982         if (skb->protocol == htons(ETH_P_IP))
 983                 return tcp_v4_conn_request(sk, skb);
 984
 985         if (!ipv6_unicast_destination(skb))
 986                 goto drop;
 987
 988         return tcp_conn_request(&tcp6_request_sock_ops,
 989                                 &tcp_request_sock_ipv6_ops, sk, skb);
 990
 991 drop:
 992         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 993         return 0; /* don't send reset */
 994 }
 995
 996 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 997                                          struct request_sock *req,
 998                                          struct dst_entry *dst)
 999 {
1000         struct inet_request_sock *ireq;
1001         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1002         struct tcp6_sock *newtcp6sk;
1003         struct inet_sock *newinet;
1004         struct tcp_sock *newtp;
1005         struct sock *newsk;
1006 #ifdef CONFIG_TCP_MD5SIG
1007         struct tcp_md5sig_key *key;
1008 #endif
1009         struct flowi6 fl6;
1010
1011         if (skb->protocol == htons(ETH_P_IP)) {
1012                 /*
1013                  *      v6 mapped
1014                  */
1015
1016                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1017
1018                 if (newsk == NULL)
1019                         return NULL;
1020
1021                 newtcp6sk = (struct tcp6_sock *)newsk;
1022                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1023
1024                 newinet = inet_sk(newsk);
1025                 newnp = inet6_sk(newsk);
1026                 newtp = tcp_sk(newsk);
1027
1028                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1029
1030                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1031
1032                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1033                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1034 #ifdef CONFIG_TCP_MD5SIG
1035                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1036 #endif
1037
1038                 newnp->ipv6_ac_list = NULL;
1039                 newnp->ipv6_fl_list = NULL;
1040                 newnp->pktoptions  = NULL;
1041                 newnp->opt         = NULL;
1042                 newnp->mcast_oif   = tcp_v6_iif(skb);
1043                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1044                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1045                 if (np->repflow)
1046                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1047
1048                 /*
1049                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1050                  * here, tcp_create_openreq_child now does this for us, see the comment in
1051                  * that function for the gory details. -acme
1052                  */
1053
1054                 /* It is tricky place. Until this moment IPv4 tcp
1055                    worked with IPv6 icsk.icsk_af_ops.
1056                    Sync it now.
1057                  */
1058                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1059
1060                 return newsk;
1061         }
1062
1063         ireq = inet_rsk(req);
1064
1065         if (sk_acceptq_is_full(sk))
1066                 goto out_overflow;
1067
1068         if (!dst) {
1069                 dst = inet6_csk_route_req(sk, &fl6, req);
1070                 if (!dst)
1071                         goto out;
1072         }
1073
1074         newsk = tcp_create_openreq_child(sk, req, skb);
1075         if (newsk == NULL)
1076                 goto out_nonewsk;
1077
1078         /*
1079          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1080          * count here, tcp_create_openreq_child now does this for us, see the
1081          * comment in that function for the gory details. -acme
1082          */
1083
1084         newsk->sk_gso_type = SKB_GSO_TCPV6;
1085         __ip6_dst_store(newsk, dst, NULL, NULL);
1086         inet6_sk_rx_dst_set(newsk, skb);
1087
1088         newtcp6sk = (struct tcp6_sock *)newsk;
1089         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1090
1091         newtp = tcp_sk(newsk);
1092         newinet = inet_sk(newsk);
1093         newnp = inet6_sk(newsk);
1094
1095         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1096
1097         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1098         newnp->saddr = ireq->ir_v6_loc_addr;
1099         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1100         newsk->sk_bound_dev_if = ireq->ir_iif;
1101
1102         ip6_set_txhash(newsk);
1103
1104         /* Now IPv6 options...
1105
1106            First: no IPv4 options.
1107          */
1108         newinet->inet_opt = NULL;
1109         newnp->ipv6_ac_list = NULL;
1110         newnp->ipv6_fl_list = NULL;
1111
1112         /* Clone RX bits */
1113         newnp->rxopt.all = np->rxopt.all;
1114
1115         /* Clone pktoptions received with SYN */
1116         newnp->pktoptions = NULL;
1117         if (ireq->pktopts != NULL) {
1118                 newnp->pktoptions = skb_clone(ireq->pktopts,
1119                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1120                 consume_skb(ireq->pktopts);
1121                 ireq->pktopts = NULL;
1122                 if (newnp->pktoptions)
1123                         skb_set_owner_r(newnp->pktoptions, newsk);
1124         }
1125         newnp->opt        = NULL;
1126         newnp->mcast_oif  = tcp_v6_iif(skb);
1127         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1128         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1129         if (np->repflow)
1130                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1131
1132         /* Clone native IPv6 options from listening socket (if any)
1133
1134            Yes, keeping reference count would be much more clever,
1135            but we make one more one thing there: reattach optmem
1136            to newsk.
1137          */
1138         if (np->opt)
1139                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1140
1141         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1142         if (newnp->opt)
1143                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1144                                                      newnp->opt->opt_flen);
1145
1146         tcp_ca_openreq_child(newsk, dst);
1147
1148         tcp_sync_mss(newsk, dst_mtu(dst));
1149         newtp->advmss = dst_metric_advmss(dst);
1150         if (tcp_sk(sk)->rx_opt.user_mss &&
1151             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1152                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1153
1154         tcp_initialize_rcv_mss(newsk);
1155
1156         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1157         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1158
1159 #ifdef CONFIG_TCP_MD5SIG
1160         /* Copy over the MD5 key from the original socket */
1161         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1162         if (key != NULL) {
1163                 /* We're using one, so create a matching key
1164                  * on the newsk structure. If we fail to get
1165                  * memory, then we end up not copying the key
1166                  * across. Shucks.
1167                  */
1168                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1169                                AF_INET6, key->key, key->keylen,
1170                                sk_gfp_atomic(sk, GFP_ATOMIC));
1171         }
1172 #endif
1173
1174         if (__inet_inherit_port(sk, newsk) < 0) {
1175                 inet_csk_prepare_forced_close(newsk);
1176                 tcp_done(newsk);
1177                 goto out;
1178         }
1179         __inet_hash(newsk, NULL);
1180
1181         return newsk;
1182
1183 out_overflow:
1184         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1185 out_nonewsk:
1186         dst_release(dst);
1187 out:
1188         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1189         return NULL;
1190 }
1191
1192 /* The socket must have it's spinlock held when we get
1193  * here.
1194  *
1195  * We have a potential double-lock case here, so even when
1196  * doing backlog processing we use the BH locking scheme.
1197  * This is because we cannot sleep with the original spinlock
1198  * held.
1199  */
1200 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1201 {
1202         struct ipv6_pinfo *np = inet6_sk(sk);
1203         struct tcp_sock *tp;
1204         struct sk_buff *opt_skb = NULL;
1205
1206         /* Imagine: socket is IPv6. IPv4 packet arrives,
1207            goes to IPv4 receive handler and backlogged.
1208            From backlog it always goes here. Kerboom...
1209            Fortunately, tcp_rcv_established and rcv_established
1210            handle them correctly, but it is not case with
1211            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1212          */
1213
1214         if (skb->protocol == htons(ETH_P_IP))
1215                 return tcp_v4_do_rcv(sk, skb);
1216
1217         if (sk_filter(sk, skb))
1218                 goto discard;
1219
1220         /*
1221          *      socket locking is here for SMP purposes as backlog rcv
1222          *      is currently called with bh processing disabled.
1223          */
1224
1225         /* Do Stevens' IPV6_PKTOPTIONS.
1226
1227            Yes, guys, it is the only place in our code, where we
1228            may make it not affecting IPv4.
1229            The rest of code is protocol independent,
1230            and I do not like idea to uglify IPv4.
1231
1232            Actually, all the idea behind IPV6_PKTOPTIONS
1233            looks not very well thought. For now we latch
1234            options, received in the last packet, enqueued
1235            by tcp. Feel free to propose better solution.
1236                                                --ANK (980728)
1237          */
1238         if (np->rxopt.all)
1239                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1240
1241         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1242                 struct dst_entry *dst = sk->sk_rx_dst;
1243
1244                 sock_rps_save_rxhash(sk, skb);
1245                 sk_mark_napi_id(sk, skb);
1246                 if (dst) {
1247                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1248                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1249                                 dst_release(dst);
1250                                 sk->sk_rx_dst = NULL;
1251                         }
1252                 }
1253
1254                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1255                 if (opt_skb)
1256                         goto ipv6_pktoptions;
1257                 return 0;
1258         }
1259
1260         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1261                 goto csum_err;
1262
1263         if (sk->sk_state == TCP_LISTEN) {
1264                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1265                 if (!nsk)
1266                         goto discard;
1267
1268                 /*
1269                  * Queue it on the new socket if the new socket is active,
1270                  * otherwise we just shortcircuit this and continue with
1271                  * the new socket..
1272                  */
1273                 if (nsk != sk) {
1274                         sock_rps_save_rxhash(nsk, skb);
1275                         sk_mark_napi_id(sk, skb);
1276                         if (tcp_child_process(sk, nsk, skb))
1277                                 goto reset;
1278                         if (opt_skb)
1279                                 __kfree_skb(opt_skb);
1280                         return 0;
1281                 }
1282         } else
1283                 sock_rps_save_rxhash(sk, skb);
1284
1285         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1286                 goto reset;
1287         if (opt_skb)
1288                 goto ipv6_pktoptions;
1289         return 0;
1290
1291 reset:
1292         tcp_v6_send_reset(sk, skb);
1293 discard:
1294         if (opt_skb)
1295                 __kfree_skb(opt_skb);
1296         kfree_skb(skb);
1297         return 0;
1298 csum_err:
1299         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1300         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1301         goto discard;
1302
1303
1304 ipv6_pktoptions:
1305         /* Do you ask, what is it?
1306
1307            1. skb was enqueued by tcp.
1308            2. skb is added to tail of read queue, rather than out of order.
1309            3. socket is not in passive state.
1310            4. Finally, it really contains options, which user wants to receive.
1311          */
1312         tp = tcp_sk(sk);
1313         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1314             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1315                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1316                         np->mcast_oif = tcp_v6_iif(opt_skb);
1317                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1318                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1319                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1320                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1321                 if (np->repflow)
1322                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1323                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1324                         skb_set_owner_r(opt_skb, sk);
1325                         opt_skb = xchg(&np->pktoptions, opt_skb);
1326                 } else {
1327                         __kfree_skb(opt_skb);
1328                         opt_skb = xchg(&np->pktoptions, NULL);
1329                 }
1330         }
1331
1332         kfree_skb(opt_skb);
1333         return 0;
1334 }
1335
1336 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1337                            const struct tcphdr *th)
1338 {
1339         /* This is tricky: we move IP6CB at its correct location into
1340          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1341          * _decode_session6() uses IP6CB().
1342          * barrier() makes sure compiler won't play aliasing games.
1343          */
1344         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1345                 sizeof(struct inet6_skb_parm));
1346         barrier();
1347
1348         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1349         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1350                                     skb->len - th->doff*4);
1351         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1352         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1353         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1354         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1355         TCP_SKB_CB(skb)->sacked = 0;
1356 }
1357
1358 static int tcp_v6_rcv(struct sk_buff *skb)
1359 {
1360         const struct tcphdr *th;
1361         const struct ipv6hdr *hdr;
1362         struct sock *sk;
1363         int ret;
1364         struct net *net = dev_net(skb->dev);
1365
1366         if (skb->pkt_type != PACKET_HOST)
1367                 goto discard_it;
1368
1369         /*
1370          *      Count it even if it's bad.
1371          */
1372         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1373
1374         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1375                 goto discard_it;
1376
1377         th = tcp_hdr(skb);
1378
1379         if (th->doff < sizeof(struct tcphdr)/4)
1380                 goto bad_packet;
1381         if (!pskb_may_pull(skb, th->doff*4))
1382                 goto discard_it;
1383
1384         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1385                 goto csum_error;
1386
1387         th = tcp_hdr(skb);
1388         hdr = ipv6_hdr(skb);
1389
1390         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1391                                 inet6_iif(skb));
1392         if (!sk)
1393                 goto no_tcp_socket;
1394
1395 process:
1396         if (sk->sk_state == TCP_TIME_WAIT)
1397                 goto do_time_wait;
1398
1399         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1400                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1401                 goto discard_and_relse;
1402         }
1403
1404         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1405                 goto discard_and_relse;
1406
1407         tcp_v6_fill_cb(skb, hdr, th);
1408
1409 #ifdef CONFIG_TCP_MD5SIG
1410         if (tcp_v6_inbound_md5_hash(sk, skb))
1411                 goto discard_and_relse;
1412 #endif
1413
1414         if (sk_filter(sk, skb))
1415                 goto discard_and_relse;
1416
1417         sk_incoming_cpu_update(sk);
1418         skb->dev = NULL;
1419
1420         bh_lock_sock_nested(sk);
1421         ret = 0;
1422         if (!sock_owned_by_user(sk)) {
1423                 if (!tcp_prequeue(sk, skb))
1424                         ret = tcp_v6_do_rcv(sk, skb);
1425         } else if (unlikely(sk_add_backlog(sk, skb,
1426                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1427                 bh_unlock_sock(sk);
1428                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1429                 goto discard_and_relse;
1430         }
1431         bh_unlock_sock(sk);
1432
1433         sock_put(sk);
1434         return ret ? -1 : 0;
1435
1436 no_tcp_socket:
1437         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1438                 goto discard_it;
1439
1440         tcp_v6_fill_cb(skb, hdr, th);
1441
1442         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1443 csum_error:
1444                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1445 bad_packet:
1446                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1447         } else {
1448                 tcp_v6_send_reset(NULL, skb);
1449         }
1450
1451 discard_it:
1452         kfree_skb(skb);
1453         return 0;
1454
1455 discard_and_relse:
1456         sock_put(sk);
1457         goto discard_it;
1458
1459 do_time_wait:
1460         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1461                 inet_twsk_put(inet_twsk(sk));
1462                 goto discard_it;
1463         }
1464
1465         tcp_v6_fill_cb(skb, hdr, th);
1466
1467         if (skb->len < (th->doff<<2)) {
1468                 inet_twsk_put(inet_twsk(sk));
1469                 goto bad_packet;
1470         }
1471         if (tcp_checksum_complete(skb)) {
1472                 inet_twsk_put(inet_twsk(sk));
1473                 goto csum_error;
1474         }
1475
1476         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1477         case TCP_TW_SYN:
1478         {
1479                 struct sock *sk2;
1480
1481                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1482                                             &ipv6_hdr(skb)->saddr, th->source,
1483                                             &ipv6_hdr(skb)->daddr,
1484                                             ntohs(th->dest), tcp_v6_iif(skb));
1485                 if (sk2 != NULL) {
1486                         struct inet_timewait_sock *tw = inet_twsk(sk);
1487                         inet_twsk_deschedule(tw, &tcp_death_row);
1488                         inet_twsk_put(tw);
1489                         sk = sk2;
1490                         goto process;
1491                 }
1492                 /* Fall through to ACK */
1493         }
1494         case TCP_TW_ACK:
1495                 tcp_v6_timewait_ack(sk, skb);
1496                 break;
1497         case TCP_TW_RST:
1498                 goto no_tcp_socket;
1499         case TCP_TW_SUCCESS:
1500                 ;
1501         }
1502         goto discard_it;
1503 }
1504
1505 static void tcp_v6_early_demux(struct sk_buff *skb)
1506 {
1507         const struct ipv6hdr *hdr;
1508         const struct tcphdr *th;
1509         struct sock *sk;
1510
1511         if (skb->pkt_type != PACKET_HOST)
1512                 return;
1513
1514         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1515                 return;
1516
1517         hdr = ipv6_hdr(skb);
1518         th = tcp_hdr(skb);
1519
1520         if (th->doff < sizeof(struct tcphdr) / 4)
1521                 return;
1522
1523         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1524         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1525                                         &hdr->saddr, th->source,
1526                                         &hdr->daddr, ntohs(th->dest),
1527                                         inet6_iif(skb));
1528         if (sk) {
1529                 skb->sk = sk;
1530                 skb->destructor = sock_edemux;
1531                 if (sk_fullsock(sk)) {
1532                         struct dst_entry *dst = sk->sk_rx_dst;
1533
1534                         if (dst)
1535                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1536                         if (dst &&
1537                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1538                                 skb_dst_set_noref(skb, dst);
1539                 }
1540         }
1541 }
1542
1543 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1544         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1545         .twsk_unique    = tcp_twsk_unique,
1546         .twsk_destructor = tcp_twsk_destructor,
1547 };
1548
1549 static const struct inet_connection_sock_af_ops ipv6_specific = {
1550         .queue_xmit        = inet6_csk_xmit,
1551         .send_check        = tcp_v6_send_check,
1552         .rebuild_header    = inet6_sk_rebuild_header,
1553         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1554         .conn_request      = tcp_v6_conn_request,
1555         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1556         .net_header_len    = sizeof(struct ipv6hdr),
1557         .net_frag_header_len = sizeof(struct frag_hdr),
1558         .setsockopt        = ipv6_setsockopt,
1559         .getsockopt        = ipv6_getsockopt,
1560         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1561         .sockaddr_len      = sizeof(struct sockaddr_in6),
1562         .bind_conflict     = inet6_csk_bind_conflict,
1563 #ifdef CONFIG_COMPAT
1564         .compat_setsockopt = compat_ipv6_setsockopt,
1565         .compat_getsockopt = compat_ipv6_getsockopt,
1566 #endif
1567         .mtu_reduced       = tcp_v6_mtu_reduced,
1568 };
1569
1570 #ifdef CONFIG_TCP_MD5SIG
1571 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1572         .md5_lookup     =       tcp_v6_md5_lookup,
1573         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1574         .md5_parse      =       tcp_v6_parse_md5_keys,
1575 };
1576 #endif
1577
1578 /*
1579  *      TCP over IPv4 via INET6 API
1580  */
1581 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1582         .queue_xmit        = ip_queue_xmit,
1583         .send_check        = tcp_v4_send_check,
1584         .rebuild_header    = inet_sk_rebuild_header,
1585         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1586         .conn_request      = tcp_v6_conn_request,
1587         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1588         .net_header_len    = sizeof(struct iphdr),
1589         .setsockopt        = ipv6_setsockopt,
1590         .getsockopt        = ipv6_getsockopt,
1591         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1592         .sockaddr_len      = sizeof(struct sockaddr_in6),
1593         .bind_conflict     = inet6_csk_bind_conflict,
1594 #ifdef CONFIG_COMPAT
1595         .compat_setsockopt = compat_ipv6_setsockopt,
1596         .compat_getsockopt = compat_ipv6_getsockopt,
1597 #endif
1598         .mtu_reduced       = tcp_v4_mtu_reduced,
1599 };
1600
1601 #ifdef CONFIG_TCP_MD5SIG
1602 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1603         .md5_lookup     =       tcp_v4_md5_lookup,
1604         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1605         .md5_parse      =       tcp_v6_parse_md5_keys,
1606 };
1607 #endif
1608
1609 /* NOTE: A lot of things set to zero explicitly by call to
1610  *       sk_alloc() so need not be done here.
1611  */
1612 static int tcp_v6_init_sock(struct sock *sk)
1613 {
1614         struct inet_connection_sock *icsk = inet_csk(sk);
1615
1616         tcp_init_sock(sk);
1617
1618         icsk->icsk_af_ops = &ipv6_specific;
1619
1620 #ifdef CONFIG_TCP_MD5SIG
1621         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1622 #endif
1623
1624         return 0;
1625 }
1626
1627 static void tcp_v6_destroy_sock(struct sock *sk)
1628 {
1629         tcp_v4_destroy_sock(sk);
1630         inet6_destroy_sock(sk);
1631 }
1632
1633 #ifdef CONFIG_PROC_FS
1634 /* Proc filesystem TCPv6 sock list dumping. */
1635 static void get_openreq6(struct seq_file *seq,
1636                          struct request_sock *req, int i, kuid_t uid)
1637 {
1638         long ttd = req->rsk_timer.expires - jiffies;
1639         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1640         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1641
1642         if (ttd < 0)
1643                 ttd = 0;
1644
1645         seq_printf(seq,
1646                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1647                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1648                    i,
1649                    src->s6_addr32[0], src->s6_addr32[1],
1650                    src->s6_addr32[2], src->s6_addr32[3],
1651                    inet_rsk(req)->ir_num,
1652                    dest->s6_addr32[0], dest->s6_addr32[1],
1653                    dest->s6_addr32[2], dest->s6_addr32[3],
1654                    ntohs(inet_rsk(req)->ir_rmt_port),
1655                    TCP_SYN_RECV,
1656                    0, 0, /* could print option size, but that is af dependent. */
1657                    1,   /* timers active (only the expire timer) */
1658                    jiffies_to_clock_t(ttd),
1659                    req->num_timeout,
1660                    from_kuid_munged(seq_user_ns(seq), uid),
1661                    0,  /* non standard timer */
1662                    0, /* open_requests have no inode */
1663                    0, req);
1664 }
1665
1666 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1667 {
1668         const struct in6_addr *dest, *src;
1669         __u16 destp, srcp;
1670         int timer_active;
1671         unsigned long timer_expires;
1672         const struct inet_sock *inet = inet_sk(sp);
1673         const struct tcp_sock *tp = tcp_sk(sp);
1674         const struct inet_connection_sock *icsk = inet_csk(sp);
1675         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1676
1677         dest  = &sp->sk_v6_daddr;
1678         src   = &sp->sk_v6_rcv_saddr;
1679         destp = ntohs(inet->inet_dport);
1680         srcp  = ntohs(inet->inet_sport);
1681
1682         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1683                 timer_active    = 1;
1684                 timer_expires   = icsk->icsk_timeout;
1685         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1686                 timer_active    = 4;
1687                 timer_expires   = icsk->icsk_timeout;
1688         } else if (timer_pending(&sp->sk_timer)) {
1689                 timer_active    = 2;
1690                 timer_expires   = sp->sk_timer.expires;
1691         } else {
1692                 timer_active    = 0;
1693                 timer_expires = jiffies;
1694         }
1695
1696         seq_printf(seq,
1697                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1698                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1699                    i,
1700                    src->s6_addr32[0], src->s6_addr32[1],
1701                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1702                    dest->s6_addr32[0], dest->s6_addr32[1],
1703                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1704                    sp->sk_state,
1705                    tp->write_seq-tp->snd_una,
1706                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1707                    timer_active,
1708                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1709                    icsk->icsk_retransmits,
1710                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1711                    icsk->icsk_probes_out,
1712                    sock_i_ino(sp),
1713                    atomic_read(&sp->sk_refcnt), sp,
1714                    jiffies_to_clock_t(icsk->icsk_rto),
1715                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1716                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1717                    tp->snd_cwnd,
1718                    sp->sk_state == TCP_LISTEN ?
1719                         (fastopenq ? fastopenq->max_qlen : 0) :
1720                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1721                    );
1722 }
1723
1724 static void get_timewait6_sock(struct seq_file *seq,
1725                                struct inet_timewait_sock *tw, int i)
1726 {
1727         const struct in6_addr *dest, *src;
1728         __u16 destp, srcp;
1729         s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1730
1731         dest = &tw->tw_v6_daddr;
1732         src  = &tw->tw_v6_rcv_saddr;
1733         destp = ntohs(tw->tw_dport);
1734         srcp  = ntohs(tw->tw_sport);
1735
1736         seq_printf(seq,
1737                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1738                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\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                    tw->tw_substate, 0, 0,
1745                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1746                    atomic_read(&tw->tw_refcnt), tw);
1747 }
1748
1749 static int tcp6_seq_show(struct seq_file *seq, void *v)
1750 {
1751         struct tcp_iter_state *st;
1752         struct sock *sk = v;
1753
1754         if (v == SEQ_START_TOKEN) {
1755                 seq_puts(seq,
1756                          "  sl  "
1757                          "local_address                         "
1758                          "remote_address                        "
1759                          "st tx_queue rx_queue tr tm->when retrnsmt"
1760                          "   uid  timeout inode\n");
1761                 goto out;
1762         }
1763         st = seq->private;
1764
1765         switch (st->state) {
1766         case TCP_SEQ_STATE_LISTENING:
1767         case TCP_SEQ_STATE_ESTABLISHED:
1768                 if (sk->sk_state == TCP_TIME_WAIT)
1769                         get_timewait6_sock(seq, v, st->num);
1770                 else
1771                         get_tcp6_sock(seq, v, st->num);
1772                 break;
1773         case TCP_SEQ_STATE_OPENREQ:
1774                 get_openreq6(seq, v, st->num, st->uid);
1775                 break;
1776         }
1777 out:
1778         return 0;
1779 }
1780
1781 static const struct file_operations tcp6_afinfo_seq_fops = {
1782         .owner   = THIS_MODULE,
1783         .open    = tcp_seq_open,
1784         .read    = seq_read,
1785         .llseek  = seq_lseek,
1786         .release = seq_release_net
1787 };
1788
1789 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1790         .name           = "tcp6",
1791         .family         = AF_INET6,
1792         .seq_fops       = &tcp6_afinfo_seq_fops,
1793         .seq_ops        = {
1794                 .show           = tcp6_seq_show,
1795         },
1796 };
1797
1798 int __net_init tcp6_proc_init(struct net *net)
1799 {
1800         return tcp_proc_register(net, &tcp6_seq_afinfo);
1801 }
1802
1803 void tcp6_proc_exit(struct net *net)
1804 {
1805         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1806 }
1807 #endif
1808
1809 static void tcp_v6_clear_sk(struct sock *sk, int size)
1810 {
1811         struct inet_sock *inet = inet_sk(sk);
1812
1813         /* we do not want to clear pinet6 field, because of RCU lookups */
1814         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1815
1816         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1817         memset(&inet->pinet6 + 1, 0, size);
1818 }
1819
1820 struct proto tcpv6_prot = {
1821         .name                   = "TCPv6",
1822         .owner                  = THIS_MODULE,
1823         .close                  = tcp_close,
1824         .connect                = tcp_v6_connect,
1825         .disconnect             = tcp_disconnect,
1826         .accept                 = inet_csk_accept,
1827         .ioctl                  = tcp_ioctl,
1828         .init                   = tcp_v6_init_sock,
1829         .destroy                = tcp_v6_destroy_sock,
1830         .shutdown               = tcp_shutdown,
1831         .setsockopt             = tcp_setsockopt,
1832         .getsockopt             = tcp_getsockopt,
1833         .recvmsg                = tcp_recvmsg,
1834         .sendmsg                = tcp_sendmsg,
1835         .sendpage               = tcp_sendpage,
1836         .backlog_rcv            = tcp_v6_do_rcv,
1837         .release_cb             = tcp_release_cb,
1838         .hash                   = inet_hash,
1839         .unhash                 = inet_unhash,
1840         .get_port               = inet_csk_get_port,
1841         .enter_memory_pressure  = tcp_enter_memory_pressure,
1842         .stream_memory_free     = tcp_stream_memory_free,
1843         .sockets_allocated      = &tcp_sockets_allocated,
1844         .memory_allocated       = &tcp_memory_allocated,
1845         .memory_pressure        = &tcp_memory_pressure,
1846         .orphan_count           = &tcp_orphan_count,
1847         .sysctl_mem             = sysctl_tcp_mem,
1848         .sysctl_wmem            = sysctl_tcp_wmem,
1849         .sysctl_rmem            = sysctl_tcp_rmem,
1850         .max_header             = MAX_TCP_HEADER,
1851         .obj_size               = sizeof(struct tcp6_sock),
1852         .slab_flags             = SLAB_DESTROY_BY_RCU,
1853         .twsk_prot              = &tcp6_timewait_sock_ops,
1854         .rsk_prot               = &tcp6_request_sock_ops,
1855         .h.hashinfo             = &tcp_hashinfo,
1856         .no_autobind            = true,
1857 #ifdef CONFIG_COMPAT
1858         .compat_setsockopt      = compat_tcp_setsockopt,
1859         .compat_getsockopt      = compat_tcp_getsockopt,
1860 #endif
1861 #ifdef CONFIG_MEMCG_KMEM
1862         .proto_cgroup           = tcp_proto_cgroup,
1863 #endif
1864         .clear_sk               = tcp_v6_clear_sk,
1865 };
1866
1867 static const struct inet6_protocol tcpv6_protocol = {
1868         .early_demux    =       tcp_v6_early_demux,
1869         .handler        =       tcp_v6_rcv,
1870         .err_handler    =       tcp_v6_err,
1871         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1872 };
1873
1874 static struct inet_protosw tcpv6_protosw = {
1875         .type           =       SOCK_STREAM,
1876         .protocol       =       IPPROTO_TCP,
1877         .prot           =       &tcpv6_prot,
1878         .ops            =       &inet6_stream_ops,
1879         .flags          =       INET_PROTOSW_PERMANENT |
1880                                 INET_PROTOSW_ICSK,
1881 };
1882
1883 static int __net_init tcpv6_net_init(struct net *net)
1884 {
1885         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1886                                     SOCK_RAW, IPPROTO_TCP, net);
1887 }
1888
1889 static void __net_exit tcpv6_net_exit(struct net *net)
1890 {
1891         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1892 }
1893
1894 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1895 {
1896         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1897 }
1898
1899 static struct pernet_operations tcpv6_net_ops = {
1900         .init       = tcpv6_net_init,
1901         .exit       = tcpv6_net_exit,
1902         .exit_batch = tcpv6_net_exit_batch,
1903 };
1904
1905 int __init tcpv6_init(void)
1906 {
1907         int ret;
1908
1909         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1910         if (ret)
1911                 goto out;
1912
1913         /* register inet6 protocol */
1914         ret = inet6_register_protosw(&tcpv6_protosw);
1915         if (ret)
1916                 goto out_tcpv6_protocol;
1917
1918         ret = register_pernet_subsys(&tcpv6_net_ops);
1919         if (ret)
1920                 goto out_tcpv6_protosw;
1921 out:
1922         return ret;
1923
1924 out_tcpv6_protosw:
1925         inet6_unregister_protosw(&tcpv6_protosw);
1926 out_tcpv6_protocol:
1927         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1928         goto out;
1929 }
1930
1931 void tcpv6_exit(void)
1932 {
1933         unregister_pernet_subsys(&tcpv6_net_ops);
1934         inet6_unregister_protosw(&tcpv6_protosw);
1935         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1936 }