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 void tcp_v6_hash(struct sock *sk)
 108 {
 109         if (sk->sk_state != TCP_CLOSE) {
 110                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
 111                         tcp_prot.hash(sk);
 112                         return;
 113                 }
 114                 local_bh_disable();
 115                 __inet6_hash(sk, NULL);
 116                 local_bh_enable();
 117         }
 118 }
 119
 120 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 121 {
 122         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 123                                             ipv6_hdr(skb)->saddr.s6_addr32,
 124                                             tcp_hdr(skb)->dest,
 125                                             tcp_hdr(skb)->source);
 126 }
 127
 128 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 129                           int addr_len)
 130 {
 131         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 132         struct inet_sock *inet = inet_sk(sk);
 133         struct inet_connection_sock *icsk = inet_csk(sk);
 134         struct ipv6_pinfo *np = inet6_sk(sk);
 135         struct tcp_sock *tp = tcp_sk(sk);
 136         struct in6_addr *saddr = NULL, *final_p, final;
 137         struct rt6_info *rt;
 138         struct flowi6 fl6;
 139         struct dst_entry *dst;
 140         int addr_type;
 141         int err;
 142
 143         if (addr_len < SIN6_LEN_RFC2133)
 144                 return -EINVAL;
 145
 146         if (usin->sin6_family != AF_INET6)
 147                 return -EAFNOSUPPORT;
 148
 149         memset(&fl6, 0, sizeof(fl6));
 150
 151         if (np->sndflow) {
 152                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 153                 IP6_ECN_flow_init(fl6.flowlabel);
 154                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 155                         struct ip6_flowlabel *flowlabel;
 156                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 157                         if (flowlabel == NULL)
 158                                 return -EINVAL;
 159                         fl6_sock_release(flowlabel);
 160                 }
 161         }
 162
 163         /*
 164          *      connect() to INADDR_ANY means loopback (BSD'ism).
 165          */
 166
 167         if (ipv6_addr_any(&usin->sin6_addr))
 168                 usin->sin6_addr.s6_addr[15] = 0x1;
 169
 170         addr_type = ipv6_addr_type(&usin->sin6_addr);
 171
 172         if (addr_type & IPV6_ADDR_MULTICAST)
 173                 return -ENETUNREACH;
 174
 175         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 176                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 177                     usin->sin6_scope_id) {
 178                         /* If interface is set while binding, indices
 179                          * must coincide.
 180                          */
 181                         if (sk->sk_bound_dev_if &&
 182                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 183                                 return -EINVAL;
 184
 185                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 186                 }
 187
 188                 /* Connect to link-local address requires an interface */
 189                 if (!sk->sk_bound_dev_if)
 190                         return -EINVAL;
 191         }
 192
 193         if (tp->rx_opt.ts_recent_stamp &&
 194             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 195                 tp->rx_opt.ts_recent = 0;
 196                 tp->rx_opt.ts_recent_stamp = 0;
 197                 tp->write_seq = 0;
 198         }
 199
 200         sk->sk_v6_daddr = usin->sin6_addr;
 201         np->flow_label = fl6.flowlabel;
 202
 203         /*
 204          *      TCP over IPv4
 205          */
 206
 207         if (addr_type == IPV6_ADDR_MAPPED) {
 208                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 209                 struct sockaddr_in sin;
 210
 211                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 212
 213                 if (__ipv6_only_sock(sk))
 214                         return -ENETUNREACH;
 215
 216                 sin.sin_family = AF_INET;
 217                 sin.sin_port = usin->sin6_port;
 218                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 219
 220                 icsk->icsk_af_ops = &ipv6_mapped;
 221                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 222 #ifdef CONFIG_TCP_MD5SIG
 223                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 224 #endif
 225
 226                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 227
 228                 if (err) {
 229                         icsk->icsk_ext_hdr_len = exthdrlen;
 230                         icsk->icsk_af_ops = &ipv6_specific;
 231                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 232 #ifdef CONFIG_TCP_MD5SIG
 233                         tp->af_specific = &tcp_sock_ipv6_specific;
 234 #endif
 235                         goto failure;
 236                 } else {
 237                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 238                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 239                                                &sk->sk_v6_rcv_saddr);
 240                 }
 241
 242                 return err;
 243         }
 244
 245         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 246                 saddr = &sk->sk_v6_rcv_saddr;
 247
 248         fl6.flowi6_proto = IPPROTO_TCP;
 249         fl6.daddr = sk->sk_v6_daddr;
 250         fl6.saddr = saddr ? *saddr : np->saddr;
 251         fl6.flowi6_oif = sk->sk_bound_dev_if;
 252         fl6.flowi6_mark = sk->sk_mark;
 253         fl6.fl6_dport = usin->sin6_port;
 254         fl6.fl6_sport = inet->inet_sport;
 255
 256         final_p = fl6_update_dst(&fl6, np->opt, &final);
 257
 258         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 259
 260         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 261         if (IS_ERR(dst)) {
 262                 err = PTR_ERR(dst);
 263                 goto failure;
 264         }
 265
 266         if (saddr == NULL) {
 267                 saddr = &fl6.saddr;
 268                 sk->sk_v6_rcv_saddr = *saddr;
 269         }
 270
 271         /* set the source address */
 272         np->saddr = *saddr;
 273         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 274
 275         sk->sk_gso_type = SKB_GSO_TCPV6;
 276         __ip6_dst_store(sk, dst, NULL, NULL);
 277
 278         rt = (struct rt6_info *) dst;
 279         if (tcp_death_row.sysctl_tw_recycle &&
 280             !tp->rx_opt.ts_recent_stamp &&
 281             ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
 282                 tcp_fetch_timewait_stamp(sk, dst);
 283
 284         icsk->icsk_ext_hdr_len = 0;
 285         if (np->opt)
 286                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 287                                           np->opt->opt_nflen);
 288
 289         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 290
 291         inet->inet_dport = usin->sin6_port;
 292
 293         tcp_set_state(sk, TCP_SYN_SENT);
 294         err = inet6_hash_connect(&tcp_death_row, sk);
 295         if (err)
 296                 goto late_failure;
 297
 298         ip6_set_txhash(sk);
 299
 300         if (!tp->write_seq && likely(!tp->repair))
 301                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 302                                                              sk->sk_v6_daddr.s6_addr32,
 303                                                              inet->inet_sport,
 304                                                              inet->inet_dport);
 305
 306         err = tcp_connect(sk);
 307         if (err)
 308                 goto late_failure;
 309
 310         return 0;
 311
 312 late_failure:
 313         tcp_set_state(sk, TCP_CLOSE);
 314         __sk_dst_reset(sk);
 315 failure:
 316         inet->inet_dport = 0;
 317         sk->sk_route_caps = 0;
 318         return err;
 319 }
 320
 321 static void tcp_v6_mtu_reduced(struct sock *sk)
 322 {
 323         struct dst_entry *dst;
 324
 325         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 326                 return;
 327
 328         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 329         if (!dst)
 330                 return;
 331
 332         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 333                 tcp_sync_mss(sk, dst_mtu(dst));
 334                 tcp_simple_retransmit(sk);
 335         }
 336 }
 337
 338 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 339                 u8 type, u8 code, int offset, __be32 info)
 340 {
 341         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 342         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 343         struct ipv6_pinfo *np;
 344         struct sock *sk;
 345         int err;
 346         struct tcp_sock *tp;
 347         struct request_sock *fastopen;
 348         __u32 seq, snd_una;
 349         struct net *net = dev_net(skb->dev);
 350
 351         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
 352                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 353
 354         if (sk == NULL) {
 355                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 356                                    ICMP6_MIB_INERRORS);
 357                 return;
 358         }
 359
 360         if (sk->sk_state == TCP_TIME_WAIT) {
 361                 inet_twsk_put(inet_twsk(sk));
 362                 return;
 363         }
 364
 365         bh_lock_sock(sk);
 366         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 367                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 368
 369         if (sk->sk_state == TCP_CLOSE)
 370                 goto out;
 371
 372         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 373                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 374                 goto out;
 375         }
 376
 377         tp = tcp_sk(sk);
 378         seq = ntohl(th->seq);
 379         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 380         fastopen = tp->fastopen_rsk;
 381         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 382         if (sk->sk_state != TCP_LISTEN &&
 383             !between(seq, snd_una, tp->snd_nxt)) {
 384                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 385                 goto out;
 386         }
 387
 388         np = inet6_sk(sk);
 389
 390         if (type == NDISC_REDIRECT) {
 391                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 392
 393                 if (dst)
 394                         dst->ops->redirect(dst, sk, skb);
 395                 goto out;
 396         }
 397
 398         if (type == ICMPV6_PKT_TOOBIG) {
 399                 /* We are not interested in TCP_LISTEN and open_requests
 400                  * (SYN-ACKs send out by Linux are always <576bytes so
 401                  * they should go through unfragmented).
 402                  */
 403                 if (sk->sk_state == TCP_LISTEN)
 404                         goto out;
 405
 406                 if (!ip6_sk_accept_pmtu(sk))
 407                         goto out;
 408
 409                 tp->mtu_info = ntohl(info);
 410                 if (!sock_owned_by_user(sk))
 411                         tcp_v6_mtu_reduced(sk);
 412                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 413                                            &tp->tsq_flags))
 414                         sock_hold(sk);
 415                 goto out;
 416         }
 417
 418         icmpv6_err_convert(type, code, &err);
 419
 420         /* Might be for an request_sock */
 421         switch (sk->sk_state) {
 422                 struct request_sock *req, **prev;
 423         case TCP_LISTEN:
 424                 if (sock_owned_by_user(sk))
 425                         goto out;
 426
 427                 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
 428                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 429                                            &hdr->saddr, inet6_iif(skb));
 430                 if (!req)
 431                         goto out;
 432
 433                 /* ICMPs are not backlogged, hence we cannot get
 434                  * an established socket here.
 435                  */
 436                 WARN_ON(req->sk != NULL);
 437
 438                 if (seq != tcp_rsk(req)->snt_isn) {
 439                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 440                         goto out;
 441                 }
 442
 443                 inet_csk_reqsk_queue_drop(sk, req, prev);
 444                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 445                 goto out;
 446
 447         case TCP_SYN_SENT:
 448         case TCP_SYN_RECV:
 449                 /* Only in fast or simultaneous open. If a fast open socket is
 450                  * is already accepted it is treated as a connected one below.
 451                  */
 452                 if (fastopen && fastopen->sk == NULL)
 453                         break;
 454
 455                 if (!sock_owned_by_user(sk)) {
 456                         sk->sk_err = err;
 457                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 458
 459                         tcp_done(sk);
 460                 } else
 461                         sk->sk_err_soft = err;
 462                 goto out;
 463         }
 464
 465         if (!sock_owned_by_user(sk) && np->recverr) {
 466                 sk->sk_err = err;
 467                 sk->sk_error_report(sk);
 468         } else
 469                 sk->sk_err_soft = err;
 470
 471 out:
 472         bh_unlock_sock(sk);
 473         sock_put(sk);
 474 }
 475
 476
 477 static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
 478                               struct flowi *fl,
 479                               struct request_sock *req,
 480                               u16 queue_mapping,
 481                               struct tcp_fastopen_cookie *foc)
 482 {
 483         struct inet_request_sock *ireq = inet_rsk(req);
 484         struct ipv6_pinfo *np = inet6_sk(sk);
 485         struct flowi6 *fl6 = &fl->u.ip6;
 486         struct sk_buff *skb;
 487         int err = -ENOMEM;
 488
 489         /* First, grab a route. */
 490         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
 491                 goto done;
 492
 493         skb = tcp_make_synack(sk, dst, req, foc);
 494
 495         if (skb) {
 496                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 497                                     &ireq->ir_v6_rmt_addr);
 498
 499                 fl6->daddr = ireq->ir_v6_rmt_addr;
 500                 if (np->repflow && (ireq->pktopts != NULL))
 501                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 502
 503                 skb_set_queue_mapping(skb, queue_mapping);
 504                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 505                 err = net_xmit_eval(err);
 506         }
 507
 508 done:
 509         return err;
 510 }
 511
 512
 513 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 514 {
 515         kfree_skb(inet_rsk(req)->pktopts);
 516 }
 517
 518 #ifdef CONFIG_TCP_MD5SIG
 519 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 520                                                    const struct in6_addr *addr)
 521 {
 522         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 523 }
 524
 525 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 526                                                 struct sock *addr_sk)
 527 {
 528         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 529 }
 530
 531 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 532                                                       struct request_sock *req)
 533 {
 534         return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
 535 }
 536
 537 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 538                                  int optlen)
 539 {
 540         struct tcp_md5sig cmd;
 541         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 542
 543         if (optlen < sizeof(cmd))
 544                 return -EINVAL;
 545
 546         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 547                 return -EFAULT;
 548
 549         if (sin6->sin6_family != AF_INET6)
 550                 return -EINVAL;
 551
 552         if (!cmd.tcpm_keylen) {
 553                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 554                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 555                                               AF_INET);
 556                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 557                                       AF_INET6);
 558         }
 559
 560         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 561                 return -EINVAL;
 562
 563         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 564                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 565                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 566
 567         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 568                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 569 }
 570
 571 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 572                                         const struct in6_addr *daddr,
 573                                         const struct in6_addr *saddr, int nbytes)
 574 {
 575         struct tcp6_pseudohdr *bp;
 576         struct scatterlist sg;
 577
 578         bp = &hp->md5_blk.ip6;
 579         /* 1. TCP pseudo-header (RFC2460) */
 580         bp->saddr = *saddr;
 581         bp->daddr = *daddr;
 582         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 583         bp->len = cpu_to_be32(nbytes);
 584
 585         sg_init_one(&sg, bp, sizeof(*bp));
 586         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 587 }
 588
 589 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 590                                const struct in6_addr *daddr, struct in6_addr *saddr,
 591                                const struct tcphdr *th)
 592 {
 593         struct tcp_md5sig_pool *hp;
 594         struct hash_desc *desc;
 595
 596         hp = tcp_get_md5sig_pool();
 597         if (!hp)
 598                 goto clear_hash_noput;
 599         desc = &hp->md5_desc;
 600
 601         if (crypto_hash_init(desc))
 602                 goto clear_hash;
 603         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 604                 goto clear_hash;
 605         if (tcp_md5_hash_header(hp, th))
 606                 goto clear_hash;
 607         if (tcp_md5_hash_key(hp, key))
 608                 goto clear_hash;
 609         if (crypto_hash_final(desc, md5_hash))
 610                 goto clear_hash;
 611
 612         tcp_put_md5sig_pool();
 613         return 0;
 614
 615 clear_hash:
 616         tcp_put_md5sig_pool();
 617 clear_hash_noput:
 618         memset(md5_hash, 0, 16);
 619         return 1;
 620 }
 621
 622 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 623                                const struct sock *sk,
 624                                const struct request_sock *req,
 625                                const struct sk_buff *skb)
 626 {
 627         const struct in6_addr *saddr, *daddr;
 628         struct tcp_md5sig_pool *hp;
 629         struct hash_desc *desc;
 630         const struct tcphdr *th = tcp_hdr(skb);
 631
 632         if (sk) {
 633                 saddr = &inet6_sk(sk)->saddr;
 634                 daddr = &sk->sk_v6_daddr;
 635         } else if (req) {
 636                 saddr = &inet_rsk(req)->ir_v6_loc_addr;
 637                 daddr = &inet_rsk(req)->ir_v6_rmt_addr;
 638         } else {
 639                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 640                 saddr = &ip6h->saddr;
 641                 daddr = &ip6h->daddr;
 642         }
 643
 644         hp = tcp_get_md5sig_pool();
 645         if (!hp)
 646                 goto clear_hash_noput;
 647         desc = &hp->md5_desc;
 648
 649         if (crypto_hash_init(desc))
 650                 goto clear_hash;
 651
 652         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 653                 goto clear_hash;
 654         if (tcp_md5_hash_header(hp, th))
 655                 goto clear_hash;
 656         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 657                 goto clear_hash;
 658         if (tcp_md5_hash_key(hp, key))
 659                 goto clear_hash;
 660         if (crypto_hash_final(desc, md5_hash))
 661                 goto clear_hash;
 662
 663         tcp_put_md5sig_pool();
 664         return 0;
 665
 666 clear_hash:
 667         tcp_put_md5sig_pool();
 668 clear_hash_noput:
 669         memset(md5_hash, 0, 16);
 670         return 1;
 671 }
 672
 673 static int __tcp_v6_inbound_md5_hash(struct sock *sk,
 674                                      const struct sk_buff *skb)
 675 {
 676         const __u8 *hash_location = NULL;
 677         struct tcp_md5sig_key *hash_expected;
 678         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 679         const struct tcphdr *th = tcp_hdr(skb);
 680         int genhash;
 681         u8 newhash[16];
 682
 683         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 684         hash_location = tcp_parse_md5sig_option(th);
 685
 686         /* We've parsed the options - do we have a hash? */
 687         if (!hash_expected && !hash_location)
 688                 return 0;
 689
 690         if (hash_expected && !hash_location) {
 691                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 692                 return 1;
 693         }
 694
 695         if (!hash_expected && hash_location) {
 696                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 697                 return 1;
 698         }
 699
 700         /* check the signature */
 701         genhash = tcp_v6_md5_hash_skb(newhash,
 702                                       hash_expected,
 703                                       NULL, NULL, skb);
 704
 705         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 706                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 707                                      genhash ? "failed" : "mismatch",
 708                                      &ip6h->saddr, ntohs(th->source),
 709                                      &ip6h->daddr, ntohs(th->dest));
 710                 return 1;
 711         }
 712         return 0;
 713 }
 714
 715 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 716 {
 717         int ret;
 718
 719         rcu_read_lock();
 720         ret = __tcp_v6_inbound_md5_hash(sk, skb);
 721         rcu_read_unlock();
 722
 723         return ret;
 724 }
 725
 726 #endif
 727
 728 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
 729                             struct sk_buff *skb)
 730 {
 731         struct inet_request_sock *ireq = inet_rsk(req);
 732         struct ipv6_pinfo *np = inet6_sk(sk);
 733
 734         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 735         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 736
 737         ireq->ir_iif = sk->sk_bound_dev_if;
 738
 739         /* So that link locals have meaning */
 740         if (!sk->sk_bound_dev_if &&
 741             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 742                 ireq->ir_iif = tcp_v6_iif(skb);
 743
 744         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 745             (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
 746              np->rxopt.bits.rxinfo ||
 747              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 748              np->rxopt.bits.rxohlim || np->repflow)) {
 749                 atomic_inc(&skb->users);
 750                 ireq->pktopts = skb;
 751         }
 752 }
 753
 754 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 755                                           const struct request_sock *req,
 756                                           bool *strict)
 757 {
 758         if (strict)
 759                 *strict = true;
 760         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 761 }
 762
 763 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 764         .family         =       AF_INET6,
 765         .obj_size       =       sizeof(struct tcp6_request_sock),
 766         .rtx_syn_ack    =       tcp_rtx_synack,
 767         .send_ack       =       tcp_v6_reqsk_send_ack,
 768         .destructor     =       tcp_v6_reqsk_destructor,
 769         .send_reset     =       tcp_v6_send_reset,
 770         .syn_ack_timeout =      tcp_syn_ack_timeout,
 771 };
 772
 773 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 774         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 775                                 sizeof(struct ipv6hdr),
 776 #ifdef CONFIG_TCP_MD5SIG
 777         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 778         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 779 #endif
 780         .init_req       =       tcp_v6_init_req,
 781 #ifdef CONFIG_SYN_COOKIES
 782         .cookie_init_seq =      cookie_v6_init_sequence,
 783 #endif
 784         .route_req      =       tcp_v6_route_req,
 785         .init_seq       =       tcp_v6_init_sequence,
 786         .send_synack    =       tcp_v6_send_synack,
 787         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 788 };
 789
 790 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
 791                                  u32 tsval, u32 tsecr, int oif,
 792                                  struct tcp_md5sig_key *key, int rst, u8 tclass,
 793                                  u32 label)
 794 {
 795         const struct tcphdr *th = tcp_hdr(skb);
 796         struct tcphdr *t1;
 797         struct sk_buff *buff;
 798         struct flowi6 fl6;
 799         struct net *net = dev_net(skb_dst(skb)->dev);
 800         struct sock *ctl_sk = net->ipv6.tcp_sk;
 801         unsigned int tot_len = sizeof(struct tcphdr);
 802         struct dst_entry *dst;
 803         __be32 *topt;
 804
 805         if (tsecr)
 806                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 807 #ifdef CONFIG_TCP_MD5SIG
 808         if (key)
 809                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 810 #endif
 811
 812         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 813                          GFP_ATOMIC);
 814         if (buff == NULL)
 815                 return;
 816
 817         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 818
 819         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 820         skb_reset_transport_header(buff);
 821
 822         /* Swap the send and the receive. */
 823         memset(t1, 0, sizeof(*t1));
 824         t1->dest = th->source;
 825         t1->source = th->dest;
 826         t1->doff = tot_len / 4;
 827         t1->seq = htonl(seq);
 828         t1->ack_seq = htonl(ack);
 829         t1->ack = !rst || !th->ack;
 830         t1->rst = rst;
 831         t1->window = htons(win);
 832
 833         topt = (__be32 *)(t1 + 1);
 834
 835         if (tsecr) {
 836                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 837                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 838                 *topt++ = htonl(tsval);
 839                 *topt++ = htonl(tsecr);
 840         }
 841
 842 #ifdef CONFIG_TCP_MD5SIG
 843         if (key) {
 844                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 845                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 846                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 847                                     &ipv6_hdr(skb)->saddr,
 848                                     &ipv6_hdr(skb)->daddr, t1);
 849         }
 850 #endif
 851
 852         memset(&fl6, 0, sizeof(fl6));
 853         fl6.daddr = ipv6_hdr(skb)->saddr;
 854         fl6.saddr = ipv6_hdr(skb)->daddr;
 855         fl6.flowlabel = label;
 856
 857         buff->ip_summed = CHECKSUM_PARTIAL;
 858         buff->csum = 0;
 859
 860         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 861
 862         fl6.flowi6_proto = IPPROTO_TCP;
 863         if (rt6_need_strict(&fl6.daddr) && !oif)
 864                 fl6.flowi6_oif = tcp_v6_iif(skb);
 865         else
 866                 fl6.flowi6_oif = oif;
 867         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 868         fl6.fl6_dport = t1->dest;
 869         fl6.fl6_sport = t1->source;
 870         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 871
 872         /* Pass a socket to ip6_dst_lookup either it is for RST
 873          * Underlying function will use this to retrieve the network
 874          * namespace
 875          */
 876         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 877         if (!IS_ERR(dst)) {
 878                 skb_dst_set(buff, dst);
 879                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 880                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 881                 if (rst)
 882                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 883                 return;
 884         }
 885
 886         kfree_skb(buff);
 887 }
 888
 889 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 890 {
 891         const struct tcphdr *th = tcp_hdr(skb);
 892         u32 seq = 0, ack_seq = 0;
 893         struct tcp_md5sig_key *key = NULL;
 894 #ifdef CONFIG_TCP_MD5SIG
 895         const __u8 *hash_location = NULL;
 896         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 897         unsigned char newhash[16];
 898         int genhash;
 899         struct sock *sk1 = NULL;
 900 #endif
 901         int oif;
 902
 903         if (th->rst)
 904                 return;
 905
 906         /* If sk not NULL, it means we did a successful lookup and incoming
 907          * route had to be correct. prequeue might have dropped our dst.
 908          */
 909         if (!sk && !ipv6_unicast_destination(skb))
 910                 return;
 911
 912 #ifdef CONFIG_TCP_MD5SIG
 913         hash_location = tcp_parse_md5sig_option(th);
 914         if (!sk && hash_location) {
 915                 /*
 916                  * active side is lost. Try to find listening socket through
 917                  * source port, and then find md5 key through listening socket.
 918                  * we are not loose security here:
 919                  * Incoming packet is checked with md5 hash with finding key,
 920                  * no RST generated if md5 hash doesn't match.
 921                  */
 922                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 923                                            &tcp_hashinfo, &ipv6h->saddr,
 924                                            th->source, &ipv6h->daddr,
 925                                            ntohs(th->source), tcp_v6_iif(skb));
 926                 if (!sk1)
 927                         return;
 928
 929                 rcu_read_lock();
 930                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 931                 if (!key)
 932                         goto release_sk1;
 933
 934                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
 935                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 936                         goto release_sk1;
 937         } else {
 938                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 939         }
 940 #endif
 941
 942         if (th->ack)
 943                 seq = ntohl(th->ack_seq);
 944         else
 945                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 946                           (th->doff << 2);
 947
 948         oif = sk ? sk->sk_bound_dev_if : 0;
 949         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 950
 951 #ifdef CONFIG_TCP_MD5SIG
 952 release_sk1:
 953         if (sk1) {
 954                 rcu_read_unlock();
 955                 sock_put(sk1);
 956         }
 957 #endif
 958 }
 959
 960 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
 961                             u32 win, u32 tsval, u32 tsecr, int oif,
 962                             struct tcp_md5sig_key *key, u8 tclass,
 963                             u32 label)
 964 {
 965         tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, oif, key, 0, tclass,
 966                              label);
 967 }
 968
 969 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 970 {
 971         struct inet_timewait_sock *tw = inet_twsk(sk);
 972         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 973
 974         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 975                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 976                         tcp_time_stamp + tcptw->tw_ts_offset,
 977                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 978                         tw->tw_tclass, (tw->tw_flowlabel << 12));
 979
 980         inet_twsk_put(tw);
 981 }
 982
 983 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 984                                   struct request_sock *req)
 985 {
 986         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 987          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 988          */
 989         tcp_v6_send_ack(skb, (sk->sk_state == TCP_LISTEN) ?
 990                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 991                         tcp_rsk(req)->rcv_nxt,
 992                         req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 993                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 994                         0, 0);
 995 }
 996
 997
 998 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 999 {
1000         struct request_sock *req, **prev;
1001         const struct tcphdr *th = tcp_hdr(skb);
1002         struct sock *nsk;
1003
1004         /* Find possible connection requests. */
1005         req = inet6_csk_search_req(sk, &prev, th->source,
1006                                    &ipv6_hdr(skb)->saddr,
1007                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
1008         if (req)
1009                 return tcp_check_req(sk, skb, req, prev, false);
1010
1011         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1012                                          &ipv6_hdr(skb)->saddr, th->source,
1013                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
1014                                          tcp_v6_iif(skb));
1015
1016         if (nsk) {
1017                 if (nsk->sk_state != TCP_TIME_WAIT) {
1018                         bh_lock_sock(nsk);
1019                         return nsk;
1020                 }
1021                 inet_twsk_put(inet_twsk(nsk));
1022                 return NULL;
1023         }
1024
1025 #ifdef CONFIG_SYN_COOKIES
1026         if (!th->syn)
1027                 sk = cookie_v6_check(sk, skb);
1028 #endif
1029         return sk;
1030 }
1031
1032 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1033 {
1034         if (skb->protocol == htons(ETH_P_IP))
1035                 return tcp_v4_conn_request(sk, skb);
1036
1037         if (!ipv6_unicast_destination(skb))
1038                 goto drop;
1039
1040         return tcp_conn_request(&tcp6_request_sock_ops,
1041                                 &tcp_request_sock_ipv6_ops, sk, skb);
1042
1043 drop:
1044         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1045         return 0; /* don't send reset */
1046 }
1047
1048 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1049                                          struct request_sock *req,
1050                                          struct dst_entry *dst)
1051 {
1052         struct inet_request_sock *ireq;
1053         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1054         struct tcp6_sock *newtcp6sk;
1055         struct inet_sock *newinet;
1056         struct tcp_sock *newtp;
1057         struct sock *newsk;
1058 #ifdef CONFIG_TCP_MD5SIG
1059         struct tcp_md5sig_key *key;
1060 #endif
1061         struct flowi6 fl6;
1062
1063         if (skb->protocol == htons(ETH_P_IP)) {
1064                 /*
1065                  *      v6 mapped
1066                  */
1067
1068                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1069
1070                 if (newsk == NULL)
1071                         return NULL;
1072
1073                 newtcp6sk = (struct tcp6_sock *)newsk;
1074                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1075
1076                 newinet = inet_sk(newsk);
1077                 newnp = inet6_sk(newsk);
1078                 newtp = tcp_sk(newsk);
1079
1080                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1081
1082                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
1083
1084                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1085
1086                 newsk->sk_v6_rcv_saddr = newnp->saddr;
1087
1088                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1089                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1090 #ifdef CONFIG_TCP_MD5SIG
1091                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1092 #endif
1093
1094                 newnp->ipv6_ac_list = NULL;
1095                 newnp->ipv6_fl_list = NULL;
1096                 newnp->pktoptions  = NULL;
1097                 newnp->opt         = NULL;
1098                 newnp->mcast_oif   = tcp_v6_iif(skb);
1099                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1100                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1101                 if (np->repflow)
1102                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1103
1104                 /*
1105                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1106                  * here, tcp_create_openreq_child now does this for us, see the comment in
1107                  * that function for the gory details. -acme
1108                  */
1109
1110                 /* It is tricky place. Until this moment IPv4 tcp
1111                    worked with IPv6 icsk.icsk_af_ops.
1112                    Sync it now.
1113                  */
1114                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1115
1116                 return newsk;
1117         }
1118
1119         ireq = inet_rsk(req);
1120
1121         if (sk_acceptq_is_full(sk))
1122                 goto out_overflow;
1123
1124         if (!dst) {
1125                 dst = inet6_csk_route_req(sk, &fl6, req);
1126                 if (!dst)
1127                         goto out;
1128         }
1129
1130         newsk = tcp_create_openreq_child(sk, req, skb);
1131         if (newsk == NULL)
1132                 goto out_nonewsk;
1133
1134         /*
1135          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1136          * count here, tcp_create_openreq_child now does this for us, see the
1137          * comment in that function for the gory details. -acme
1138          */
1139
1140         newsk->sk_gso_type = SKB_GSO_TCPV6;
1141         __ip6_dst_store(newsk, dst, NULL, NULL);
1142         inet6_sk_rx_dst_set(newsk, skb);
1143
1144         newtcp6sk = (struct tcp6_sock *)newsk;
1145         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1146
1147         newtp = tcp_sk(newsk);
1148         newinet = inet_sk(newsk);
1149         newnp = inet6_sk(newsk);
1150
1151         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1152
1153         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1154         newnp->saddr = ireq->ir_v6_loc_addr;
1155         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1156         newsk->sk_bound_dev_if = ireq->ir_iif;
1157
1158         ip6_set_txhash(newsk);
1159
1160         /* Now IPv6 options...
1161
1162            First: no IPv4 options.
1163          */
1164         newinet->inet_opt = NULL;
1165         newnp->ipv6_ac_list = NULL;
1166         newnp->ipv6_fl_list = NULL;
1167
1168         /* Clone RX bits */
1169         newnp->rxopt.all = np->rxopt.all;
1170
1171         /* Clone pktoptions received with SYN */
1172         newnp->pktoptions = NULL;
1173         if (ireq->pktopts != NULL) {
1174                 newnp->pktoptions = skb_clone(ireq->pktopts,
1175                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1176                 consume_skb(ireq->pktopts);
1177                 ireq->pktopts = NULL;
1178                 if (newnp->pktoptions)
1179                         skb_set_owner_r(newnp->pktoptions, newsk);
1180         }
1181         newnp->opt        = NULL;
1182         newnp->mcast_oif  = tcp_v6_iif(skb);
1183         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1184         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1185         if (np->repflow)
1186                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1187
1188         /* Clone native IPv6 options from listening socket (if any)
1189
1190            Yes, keeping reference count would be much more clever,
1191            but we make one more one thing there: reattach optmem
1192            to newsk.
1193          */
1194         if (np->opt)
1195                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1196
1197         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1198         if (newnp->opt)
1199                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1200                                                      newnp->opt->opt_flen);
1201
1202         tcp_sync_mss(newsk, dst_mtu(dst));
1203         newtp->advmss = dst_metric_advmss(dst);
1204         if (tcp_sk(sk)->rx_opt.user_mss &&
1205             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1206                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1207
1208         tcp_initialize_rcv_mss(newsk);
1209
1210         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1211         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1212
1213 #ifdef CONFIG_TCP_MD5SIG
1214         /* Copy over the MD5 key from the original socket */
1215         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1216         if (key != NULL) {
1217                 /* We're using one, so create a matching key
1218                  * on the newsk structure. If we fail to get
1219                  * memory, then we end up not copying the key
1220                  * across. Shucks.
1221                  */
1222                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1223                                AF_INET6, key->key, key->keylen,
1224                                sk_gfp_atomic(sk, GFP_ATOMIC));
1225         }
1226 #endif
1227
1228         if (__inet_inherit_port(sk, newsk) < 0) {
1229                 inet_csk_prepare_forced_close(newsk);
1230                 tcp_done(newsk);
1231                 goto out;
1232         }
1233         __inet6_hash(newsk, NULL);
1234
1235         return newsk;
1236
1237 out_overflow:
1238         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1239 out_nonewsk:
1240         dst_release(dst);
1241 out:
1242         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1243         return NULL;
1244 }
1245
1246 /* The socket must have it's spinlock held when we get
1247  * here.
1248  *
1249  * We have a potential double-lock case here, so even when
1250  * doing backlog processing we use the BH locking scheme.
1251  * This is because we cannot sleep with the original spinlock
1252  * held.
1253  */
1254 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1255 {
1256         struct ipv6_pinfo *np = inet6_sk(sk);
1257         struct tcp_sock *tp;
1258         struct sk_buff *opt_skb = NULL;
1259
1260         /* Imagine: socket is IPv6. IPv4 packet arrives,
1261            goes to IPv4 receive handler and backlogged.
1262            From backlog it always goes here. Kerboom...
1263            Fortunately, tcp_rcv_established and rcv_established
1264            handle them correctly, but it is not case with
1265            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1266          */
1267
1268         if (skb->protocol == htons(ETH_P_IP))
1269                 return tcp_v4_do_rcv(sk, skb);
1270
1271         if (sk_filter(sk, skb))
1272                 goto discard;
1273
1274         /*
1275          *      socket locking is here for SMP purposes as backlog rcv
1276          *      is currently called with bh processing disabled.
1277          */
1278
1279         /* Do Stevens' IPV6_PKTOPTIONS.
1280
1281            Yes, guys, it is the only place in our code, where we
1282            may make it not affecting IPv4.
1283            The rest of code is protocol independent,
1284            and I do not like idea to uglify IPv4.
1285
1286            Actually, all the idea behind IPV6_PKTOPTIONS
1287            looks not very well thought. For now we latch
1288            options, received in the last packet, enqueued
1289            by tcp. Feel free to propose better solution.
1290                                                --ANK (980728)
1291          */
1292         if (np->rxopt.all)
1293                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1294
1295         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1296                 struct dst_entry *dst = sk->sk_rx_dst;
1297
1298                 sock_rps_save_rxhash(sk, skb);
1299                 if (dst) {
1300                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1301                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1302                                 dst_release(dst);
1303                                 sk->sk_rx_dst = NULL;
1304                         }
1305                 }
1306
1307                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1308                 if (opt_skb)
1309                         goto ipv6_pktoptions;
1310                 return 0;
1311         }
1312
1313         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1314                 goto csum_err;
1315
1316         if (sk->sk_state == TCP_LISTEN) {
1317                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1318                 if (!nsk)
1319                         goto discard;
1320
1321                 /*
1322                  * Queue it on the new socket if the new socket is active,
1323                  * otherwise we just shortcircuit this and continue with
1324                  * the new socket..
1325                  */
1326                 if (nsk != sk) {
1327                         sock_rps_save_rxhash(nsk, skb);
1328                         if (tcp_child_process(sk, nsk, skb))
1329                                 goto reset;
1330                         if (opt_skb)
1331                                 __kfree_skb(opt_skb);
1332                         return 0;
1333                 }
1334         } else
1335                 sock_rps_save_rxhash(sk, skb);
1336
1337         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1338                 goto reset;
1339         if (opt_skb)
1340                 goto ipv6_pktoptions;
1341         return 0;
1342
1343 reset:
1344         tcp_v6_send_reset(sk, skb);
1345 discard:
1346         if (opt_skb)
1347                 __kfree_skb(opt_skb);
1348         kfree_skb(skb);
1349         return 0;
1350 csum_err:
1351         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1352         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1353         goto discard;
1354
1355
1356 ipv6_pktoptions:
1357         /* Do you ask, what is it?
1358
1359            1. skb was enqueued by tcp.
1360            2. skb is added to tail of read queue, rather than out of order.
1361            3. socket is not in passive state.
1362            4. Finally, it really contains options, which user wants to receive.
1363          */
1364         tp = tcp_sk(sk);
1365         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1366             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1367                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1368                         np->mcast_oif = tcp_v6_iif(opt_skb);
1369                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1370                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1371                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1372                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1373                 if (np->repflow)
1374                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1375                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1376                         skb_set_owner_r(opt_skb, sk);
1377                         opt_skb = xchg(&np->pktoptions, opt_skb);
1378                 } else {
1379                         __kfree_skb(opt_skb);
1380                         opt_skb = xchg(&np->pktoptions, NULL);
1381                 }
1382         }
1383
1384         kfree_skb(opt_skb);
1385         return 0;
1386 }
1387
1388 static int tcp_v6_rcv(struct sk_buff *skb)
1389 {
1390         const struct tcphdr *th;
1391         const struct ipv6hdr *hdr;
1392         struct sock *sk;
1393         int ret;
1394         struct net *net = dev_net(skb->dev);
1395
1396         if (skb->pkt_type != PACKET_HOST)
1397                 goto discard_it;
1398
1399         /*
1400          *      Count it even if it's bad.
1401          */
1402         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1403
1404         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1405                 goto discard_it;
1406
1407         th = tcp_hdr(skb);
1408
1409         if (th->doff < sizeof(struct tcphdr)/4)
1410                 goto bad_packet;
1411         if (!pskb_may_pull(skb, th->doff*4))
1412                 goto discard_it;
1413
1414         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1415                 goto csum_error;
1416
1417         th = tcp_hdr(skb);
1418         hdr = ipv6_hdr(skb);
1419         /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
1420          * barrier() makes sure compiler wont play fool^Waliasing games.
1421          */
1422         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1423                 sizeof(struct inet6_skb_parm));
1424         barrier();
1425
1426         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1427         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1428                                     skb->len - th->doff*4);
1429         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1430         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1431         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1432         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1433         TCP_SKB_CB(skb)->sacked = 0;
1434
1435         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1436                                 tcp_v6_iif(skb));
1437         if (!sk)
1438                 goto no_tcp_socket;
1439
1440 process:
1441         if (sk->sk_state == TCP_TIME_WAIT)
1442                 goto do_time_wait;
1443
1444         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1445                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1446                 goto discard_and_relse;
1447         }
1448
1449         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1450                 goto discard_and_relse;
1451
1452 #ifdef CONFIG_TCP_MD5SIG
1453         if (tcp_v6_inbound_md5_hash(sk, skb))
1454                 goto discard_and_relse;
1455 #endif
1456
1457         if (sk_filter(sk, skb))
1458                 goto discard_and_relse;
1459
1460         sk_mark_napi_id(sk, skb);
1461         skb->dev = NULL;
1462
1463         bh_lock_sock_nested(sk);
1464         ret = 0;
1465         if (!sock_owned_by_user(sk)) {
1466                 if (!tcp_prequeue(sk, skb))
1467                         ret = tcp_v6_do_rcv(sk, skb);
1468         } else if (unlikely(sk_add_backlog(sk, skb,
1469                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1470                 bh_unlock_sock(sk);
1471                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1472                 goto discard_and_relse;
1473         }
1474         bh_unlock_sock(sk);
1475
1476         sock_put(sk);
1477         return ret ? -1 : 0;
1478
1479 no_tcp_socket:
1480         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1481                 goto discard_it;
1482
1483         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1484 csum_error:
1485                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1486 bad_packet:
1487                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1488         } else {
1489                 tcp_v6_send_reset(NULL, skb);
1490         }
1491
1492 discard_it:
1493         kfree_skb(skb);
1494         return 0;
1495
1496 discard_and_relse:
1497         sock_put(sk);
1498         goto discard_it;
1499
1500 do_time_wait:
1501         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1502                 inet_twsk_put(inet_twsk(sk));
1503                 goto discard_it;
1504         }
1505
1506         if (skb->len < (th->doff<<2)) {
1507                 inet_twsk_put(inet_twsk(sk));
1508                 goto bad_packet;
1509         }
1510         if (tcp_checksum_complete(skb)) {
1511                 inet_twsk_put(inet_twsk(sk));
1512                 goto csum_error;
1513         }
1514
1515         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1516         case TCP_TW_SYN:
1517         {
1518                 struct sock *sk2;
1519
1520                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1521                                             &ipv6_hdr(skb)->saddr, th->source,
1522                                             &ipv6_hdr(skb)->daddr,
1523                                             ntohs(th->dest), tcp_v6_iif(skb));
1524                 if (sk2 != NULL) {
1525                         struct inet_timewait_sock *tw = inet_twsk(sk);
1526                         inet_twsk_deschedule(tw, &tcp_death_row);
1527                         inet_twsk_put(tw);
1528                         sk = sk2;
1529                         goto process;
1530                 }
1531                 /* Fall through to ACK */
1532         }
1533         case TCP_TW_ACK:
1534                 tcp_v6_timewait_ack(sk, skb);
1535                 break;
1536         case TCP_TW_RST:
1537                 goto no_tcp_socket;
1538         case TCP_TW_SUCCESS:
1539                 ;
1540         }
1541         goto discard_it;
1542 }
1543
1544 static void tcp_v6_early_demux(struct sk_buff *skb)
1545 {
1546         const struct ipv6hdr *hdr;
1547         const struct tcphdr *th;
1548         struct sock *sk;
1549
1550         if (skb->pkt_type != PACKET_HOST)
1551                 return;
1552
1553         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1554                 return;
1555
1556         hdr = ipv6_hdr(skb);
1557         th = tcp_hdr(skb);
1558
1559         if (th->doff < sizeof(struct tcphdr) / 4)
1560                 return;
1561
1562         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1563         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1564                                         &hdr->saddr, th->source,
1565                                         &hdr->daddr, ntohs(th->dest),
1566                                         inet6_iif(skb));
1567         if (sk) {
1568                 skb->sk = sk;
1569                 skb->destructor = sock_edemux;
1570                 if (sk->sk_state != TCP_TIME_WAIT) {
1571                         struct dst_entry *dst = sk->sk_rx_dst;
1572
1573                         if (dst)
1574                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1575                         if (dst &&
1576                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1577                                 skb_dst_set_noref(skb, dst);
1578                 }
1579         }
1580 }
1581
1582 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1583         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1584         .twsk_unique    = tcp_twsk_unique,
1585         .twsk_destructor = tcp_twsk_destructor,
1586 };
1587
1588 static const struct inet_connection_sock_af_ops ipv6_specific = {
1589         .queue_xmit        = inet6_csk_xmit,
1590         .send_check        = tcp_v6_send_check,
1591         .rebuild_header    = inet6_sk_rebuild_header,
1592         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1593         .conn_request      = tcp_v6_conn_request,
1594         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1595         .net_header_len    = sizeof(struct ipv6hdr),
1596         .net_frag_header_len = sizeof(struct frag_hdr),
1597         .setsockopt        = ipv6_setsockopt,
1598         .getsockopt        = ipv6_getsockopt,
1599         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1600         .sockaddr_len      = sizeof(struct sockaddr_in6),
1601         .bind_conflict     = inet6_csk_bind_conflict,
1602 #ifdef CONFIG_COMPAT
1603         .compat_setsockopt = compat_ipv6_setsockopt,
1604         .compat_getsockopt = compat_ipv6_getsockopt,
1605 #endif
1606         .mtu_reduced       = tcp_v6_mtu_reduced,
1607 };
1608
1609 #ifdef CONFIG_TCP_MD5SIG
1610 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1611         .md5_lookup     =       tcp_v6_md5_lookup,
1612         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1613         .md5_parse      =       tcp_v6_parse_md5_keys,
1614 };
1615 #endif
1616
1617 /*
1618  *      TCP over IPv4 via INET6 API
1619  */
1620 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1621         .queue_xmit        = ip_queue_xmit,
1622         .send_check        = tcp_v4_send_check,
1623         .rebuild_header    = inet_sk_rebuild_header,
1624         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1625         .conn_request      = tcp_v6_conn_request,
1626         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1627         .net_header_len    = sizeof(struct iphdr),
1628         .setsockopt        = ipv6_setsockopt,
1629         .getsockopt        = ipv6_getsockopt,
1630         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1631         .sockaddr_len      = sizeof(struct sockaddr_in6),
1632         .bind_conflict     = inet6_csk_bind_conflict,
1633 #ifdef CONFIG_COMPAT
1634         .compat_setsockopt = compat_ipv6_setsockopt,
1635         .compat_getsockopt = compat_ipv6_getsockopt,
1636 #endif
1637         .mtu_reduced       = tcp_v4_mtu_reduced,
1638 };
1639
1640 #ifdef CONFIG_TCP_MD5SIG
1641 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1642         .md5_lookup     =       tcp_v4_md5_lookup,
1643         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1644         .md5_parse      =       tcp_v6_parse_md5_keys,
1645 };
1646 #endif
1647
1648 /* NOTE: A lot of things set to zero explicitly by call to
1649  *       sk_alloc() so need not be done here.
1650  */
1651 static int tcp_v6_init_sock(struct sock *sk)
1652 {
1653         struct inet_connection_sock *icsk = inet_csk(sk);
1654
1655         tcp_init_sock(sk);
1656
1657         icsk->icsk_af_ops = &ipv6_specific;
1658
1659 #ifdef CONFIG_TCP_MD5SIG
1660         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1661 #endif
1662
1663         return 0;
1664 }
1665
1666 static void tcp_v6_destroy_sock(struct sock *sk)
1667 {
1668         tcp_v4_destroy_sock(sk);
1669         inet6_destroy_sock(sk);
1670 }
1671
1672 #ifdef CONFIG_PROC_FS
1673 /* Proc filesystem TCPv6 sock list dumping. */
1674 static void get_openreq6(struct seq_file *seq,
1675                          const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1676 {
1677         int ttd = req->expires - jiffies;
1678         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1679         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1680
1681         if (ttd < 0)
1682                 ttd = 0;
1683
1684         seq_printf(seq,
1685                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1686                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1687                    i,
1688                    src->s6_addr32[0], src->s6_addr32[1],
1689                    src->s6_addr32[2], src->s6_addr32[3],
1690                    inet_rsk(req)->ir_num,
1691                    dest->s6_addr32[0], dest->s6_addr32[1],
1692                    dest->s6_addr32[2], dest->s6_addr32[3],
1693                    ntohs(inet_rsk(req)->ir_rmt_port),
1694                    TCP_SYN_RECV,
1695                    0, 0, /* could print option size, but that is af dependent. */
1696                    1,   /* timers active (only the expire timer) */
1697                    jiffies_to_clock_t(ttd),
1698                    req->num_timeout,
1699                    from_kuid_munged(seq_user_ns(seq), uid),
1700                    0,  /* non standard timer */
1701                    0, /* open_requests have no inode */
1702                    0, req);
1703 }
1704
1705 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1706 {
1707         const struct in6_addr *dest, *src;
1708         __u16 destp, srcp;
1709         int timer_active;
1710         unsigned long timer_expires;
1711         const struct inet_sock *inet = inet_sk(sp);
1712         const struct tcp_sock *tp = tcp_sk(sp);
1713         const struct inet_connection_sock *icsk = inet_csk(sp);
1714         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1715
1716         dest  = &sp->sk_v6_daddr;
1717         src   = &sp->sk_v6_rcv_saddr;
1718         destp = ntohs(inet->inet_dport);
1719         srcp  = ntohs(inet->inet_sport);
1720
1721         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1722                 timer_active    = 1;
1723                 timer_expires   = icsk->icsk_timeout;
1724         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1725                 timer_active    = 4;
1726                 timer_expires   = icsk->icsk_timeout;
1727         } else if (timer_pending(&sp->sk_timer)) {
1728                 timer_active    = 2;
1729                 timer_expires   = sp->sk_timer.expires;
1730         } else {
1731                 timer_active    = 0;
1732                 timer_expires = jiffies;
1733         }
1734
1735         seq_printf(seq,
1736                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1737                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1738                    i,
1739                    src->s6_addr32[0], src->s6_addr32[1],
1740                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1741                    dest->s6_addr32[0], dest->s6_addr32[1],
1742                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1743                    sp->sk_state,
1744                    tp->write_seq-tp->snd_una,
1745                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1746                    timer_active,
1747                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1748                    icsk->icsk_retransmits,
1749                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1750                    icsk->icsk_probes_out,
1751                    sock_i_ino(sp),
1752                    atomic_read(&sp->sk_refcnt), sp,
1753                    jiffies_to_clock_t(icsk->icsk_rto),
1754                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1755                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1756                    tp->snd_cwnd,
1757                    sp->sk_state == TCP_LISTEN ?
1758                         (fastopenq ? fastopenq->max_qlen : 0) :
1759                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1760                    );
1761 }
1762
1763 static void get_timewait6_sock(struct seq_file *seq,
1764                                struct inet_timewait_sock *tw, int i)
1765 {
1766         const struct in6_addr *dest, *src;
1767         __u16 destp, srcp;
1768         s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1769
1770         dest = &tw->tw_v6_daddr;
1771         src  = &tw->tw_v6_rcv_saddr;
1772         destp = ntohs(tw->tw_dport);
1773         srcp  = ntohs(tw->tw_sport);
1774
1775         seq_printf(seq,
1776                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1777                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1778                    i,
1779                    src->s6_addr32[0], src->s6_addr32[1],
1780                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1781                    dest->s6_addr32[0], dest->s6_addr32[1],
1782                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1783                    tw->tw_substate, 0, 0,
1784                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1785                    atomic_read(&tw->tw_refcnt), tw);
1786 }
1787
1788 static int tcp6_seq_show(struct seq_file *seq, void *v)
1789 {
1790         struct tcp_iter_state *st;
1791         struct sock *sk = v;
1792
1793         if (v == SEQ_START_TOKEN) {
1794                 seq_puts(seq,
1795                          "  sl  "
1796                          "local_address                         "
1797                          "remote_address                        "
1798                          "st tx_queue rx_queue tr tm->when retrnsmt"
1799                          "   uid  timeout inode\n");
1800                 goto out;
1801         }
1802         st = seq->private;
1803
1804         switch (st->state) {
1805         case TCP_SEQ_STATE_LISTENING:
1806         case TCP_SEQ_STATE_ESTABLISHED:
1807                 if (sk->sk_state == TCP_TIME_WAIT)
1808                         get_timewait6_sock(seq, v, st->num);
1809                 else
1810                         get_tcp6_sock(seq, v, st->num);
1811                 break;
1812         case TCP_SEQ_STATE_OPENREQ:
1813                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1814                 break;
1815         }
1816 out:
1817         return 0;
1818 }
1819
1820 static const struct file_operations tcp6_afinfo_seq_fops = {
1821         .owner   = THIS_MODULE,
1822         .open    = tcp_seq_open,
1823         .read    = seq_read,
1824         .llseek  = seq_lseek,
1825         .release = seq_release_net
1826 };
1827
1828 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1829         .name           = "tcp6",
1830         .family         = AF_INET6,
1831         .seq_fops       = &tcp6_afinfo_seq_fops,
1832         .seq_ops        = {
1833                 .show           = tcp6_seq_show,
1834         },
1835 };
1836
1837 int __net_init tcp6_proc_init(struct net *net)
1838 {
1839         return tcp_proc_register(net, &tcp6_seq_afinfo);
1840 }
1841
1842 void tcp6_proc_exit(struct net *net)
1843 {
1844         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1845 }
1846 #endif
1847
1848 static void tcp_v6_clear_sk(struct sock *sk, int size)
1849 {
1850         struct inet_sock *inet = inet_sk(sk);
1851
1852         /* we do not want to clear pinet6 field, because of RCU lookups */
1853         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1854
1855         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1856         memset(&inet->pinet6 + 1, 0, size);
1857 }
1858
1859 struct proto tcpv6_prot = {
1860         .name                   = "TCPv6",
1861         .owner                  = THIS_MODULE,
1862         .close                  = tcp_close,
1863         .connect                = tcp_v6_connect,
1864         .disconnect             = tcp_disconnect,
1865         .accept                 = inet_csk_accept,
1866         .ioctl                  = tcp_ioctl,
1867         .init                   = tcp_v6_init_sock,
1868         .destroy                = tcp_v6_destroy_sock,
1869         .shutdown               = tcp_shutdown,
1870         .setsockopt             = tcp_setsockopt,
1871         .getsockopt             = tcp_getsockopt,
1872         .recvmsg                = tcp_recvmsg,
1873         .sendmsg                = tcp_sendmsg,
1874         .sendpage               = tcp_sendpage,
1875         .backlog_rcv            = tcp_v6_do_rcv,
1876         .release_cb             = tcp_release_cb,
1877         .hash                   = tcp_v6_hash,
1878         .unhash                 = inet_unhash,
1879         .get_port               = inet_csk_get_port,
1880         .enter_memory_pressure  = tcp_enter_memory_pressure,
1881         .stream_memory_free     = tcp_stream_memory_free,
1882         .sockets_allocated      = &tcp_sockets_allocated,
1883         .memory_allocated       = &tcp_memory_allocated,
1884         .memory_pressure        = &tcp_memory_pressure,
1885         .orphan_count           = &tcp_orphan_count,
1886         .sysctl_mem             = sysctl_tcp_mem,
1887         .sysctl_wmem            = sysctl_tcp_wmem,
1888         .sysctl_rmem            = sysctl_tcp_rmem,
1889         .max_header             = MAX_TCP_HEADER,
1890         .obj_size               = sizeof(struct tcp6_sock),
1891         .slab_flags             = SLAB_DESTROY_BY_RCU,
1892         .twsk_prot              = &tcp6_timewait_sock_ops,
1893         .rsk_prot               = &tcp6_request_sock_ops,
1894         .h.hashinfo             = &tcp_hashinfo,
1895         .no_autobind            = true,
1896 #ifdef CONFIG_COMPAT
1897         .compat_setsockopt      = compat_tcp_setsockopt,
1898         .compat_getsockopt      = compat_tcp_getsockopt,
1899 #endif
1900 #ifdef CONFIG_MEMCG_KMEM
1901         .proto_cgroup           = tcp_proto_cgroup,
1902 #endif
1903         .clear_sk               = tcp_v6_clear_sk,
1904 };
1905
1906 static const struct inet6_protocol tcpv6_protocol = {
1907         .early_demux    =       tcp_v6_early_demux,
1908         .handler        =       tcp_v6_rcv,
1909         .err_handler    =       tcp_v6_err,
1910         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1911 };
1912
1913 static struct inet_protosw tcpv6_protosw = {
1914         .type           =       SOCK_STREAM,
1915         .protocol       =       IPPROTO_TCP,
1916         .prot           =       &tcpv6_prot,
1917         .ops            =       &inet6_stream_ops,
1918         .flags          =       INET_PROTOSW_PERMANENT |
1919                                 INET_PROTOSW_ICSK,
1920 };
1921
1922 static int __net_init tcpv6_net_init(struct net *net)
1923 {
1924         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1925                                     SOCK_RAW, IPPROTO_TCP, net);
1926 }
1927
1928 static void __net_exit tcpv6_net_exit(struct net *net)
1929 {
1930         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1931 }
1932
1933 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1934 {
1935         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1936 }
1937
1938 static struct pernet_operations tcpv6_net_ops = {
1939         .init       = tcpv6_net_init,
1940         .exit       = tcpv6_net_exit,
1941         .exit_batch = tcpv6_net_exit_batch,
1942 };
1943
1944 int __init tcpv6_init(void)
1945 {
1946         int ret;
1947
1948         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1949         if (ret)
1950                 goto out;
1951
1952         /* register inet6 protocol */
1953         ret = inet6_register_protosw(&tcpv6_protosw);
1954         if (ret)
1955                 goto out_tcpv6_protocol;
1956
1957         ret = register_pernet_subsys(&tcpv6_net_ops);
1958         if (ret)
1959                 goto out_tcpv6_protosw;
1960 out:
1961         return ret;
1962
1963 out_tcpv6_protosw:
1964         inet6_unregister_protosw(&tcpv6_protosw);
1965 out_tcpv6_protocol:
1966         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1967         goto out;
1968 }
1969
1970 void tcpv6_exit(void)
1971 {
1972         unregister_pernet_subsys(&tcpv6_net_ops);
1973         inet6_unregister_protosw(&tcpv6_protosw);
1974         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1975 }