net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/inet_common.h>
  63 #include <net/secure_seq.h>
  64 #include <net/busy_poll.h>
  65
  66 #include <linux/proc_fs.h>
  67 #include <linux/seq_file.h>
  68
  69 #include <crypto/hash.h>
  70 #include <linux/scatterlist.h>
  71
  72 static void     tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
  73 static void     tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
  74                                       struct request_sock *req);
  75
  76 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  77
  78 static const struct inet_connection_sock_af_ops ipv6_mapped;
  79 static const struct inet_connection_sock_af_ops ipv6_specific;
  80 #ifdef CONFIG_TCP_MD5SIG
  81 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  83 #else
  84 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
  85                                                    const struct in6_addr *addr)
  86 {
  87         return NULL;
  88 }
  89 #endif
  90
  91 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  92 {
  93         struct dst_entry *dst = skb_dst(skb);
  94
  95         if (dst && dst_hold_safe(dst)) {
  96                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  97
  98                 sk->sk_rx_dst = dst;
  99                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 100                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 101         }
 102 }
 103
 104 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 105 {
 106         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 107                                             ipv6_hdr(skb)->saddr.s6_addr32,
 108                                             tcp_hdr(skb)->dest,
 109                                             tcp_hdr(skb)->source);
 110 }
 111
 112 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 113                           int addr_len)
 114 {
 115         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 116         struct inet_sock *inet = inet_sk(sk);
 117         struct inet_connection_sock *icsk = inet_csk(sk);
 118         struct ipv6_pinfo *np = inet6_sk(sk);
 119         struct tcp_sock *tp = tcp_sk(sk);
 120         struct in6_addr *saddr = NULL, *final_p, final;
 121         struct ipv6_txoptions *opt;
 122         struct flowi6 fl6;
 123         struct dst_entry *dst;
 124         int addr_type;
 125         int err;
 126
 127         if (addr_len < SIN6_LEN_RFC2133)
 128                 return -EINVAL;
 129
 130         if (usin->sin6_family != AF_INET6)
 131                 return -EAFNOSUPPORT;
 132
 133         memset(&fl6, 0, sizeof(fl6));
 134
 135         if (np->sndflow) {
 136                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 137                 IP6_ECN_flow_init(fl6.flowlabel);
 138                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 139                         struct ip6_flowlabel *flowlabel;
 140                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 141                         if (!flowlabel)
 142                                 return -EINVAL;
 143                         fl6_sock_release(flowlabel);
 144                 }
 145         }
 146
 147         /*
 148          *      connect() to INADDR_ANY means loopback (BSD'ism).
 149          */
 150
 151         if (ipv6_addr_any(&usin->sin6_addr))
 152                 usin->sin6_addr.s6_addr[15] = 0x1;
 153
 154         addr_type = ipv6_addr_type(&usin->sin6_addr);
 155
 156         if (addr_type & IPV6_ADDR_MULTICAST)
 157                 return -ENETUNREACH;
 158
 159         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 160                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 161                     usin->sin6_scope_id) {
 162                         /* If interface is set while binding, indices
 163                          * must coincide.
 164                          */
 165                         if (sk->sk_bound_dev_if &&
 166                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 167                                 return -EINVAL;
 168
 169                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 170                 }
 171
 172                 /* Connect to link-local address requires an interface */
 173                 if (!sk->sk_bound_dev_if)
 174                         return -EINVAL;
 175         }
 176
 177         if (tp->rx_opt.ts_recent_stamp &&
 178             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 179                 tp->rx_opt.ts_recent = 0;
 180                 tp->rx_opt.ts_recent_stamp = 0;
 181                 tp->write_seq = 0;
 182         }
 183
 184         sk->sk_v6_daddr = usin->sin6_addr;
 185         np->flow_label = fl6.flowlabel;
 186
 187         /*
 188          *      TCP over IPv4
 189          */
 190
 191         if (addr_type == IPV6_ADDR_MAPPED) {
 192                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 193                 struct sockaddr_in sin;
 194
 195                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 196
 197                 if (__ipv6_only_sock(sk))
 198                         return -ENETUNREACH;
 199
 200                 sin.sin_family = AF_INET;
 201                 sin.sin_port = usin->sin6_port;
 202                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 203
 204                 icsk->icsk_af_ops = &ipv6_mapped;
 205                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 206 #ifdef CONFIG_TCP_MD5SIG
 207                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 208 #endif
 209
 210                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 211
 212                 if (err) {
 213                         icsk->icsk_ext_hdr_len = exthdrlen;
 214                         icsk->icsk_af_ops = &ipv6_specific;
 215                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 216 #ifdef CONFIG_TCP_MD5SIG
 217                         tp->af_specific = &tcp_sock_ipv6_specific;
 218 #endif
 219                         goto failure;
 220                 }
 221                 np->saddr = sk->sk_v6_rcv_saddr;
 222
 223                 return err;
 224         }
 225
 226         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 227                 saddr = &sk->sk_v6_rcv_saddr;
 228
 229         fl6.flowi6_proto = IPPROTO_TCP;
 230         fl6.daddr = sk->sk_v6_daddr;
 231         fl6.saddr = saddr ? *saddr : np->saddr;
 232         fl6.flowi6_oif = sk->sk_bound_dev_if;
 233         fl6.flowi6_mark = sk->sk_mark;
 234         fl6.fl6_dport = usin->sin6_port;
 235         fl6.fl6_sport = inet->inet_sport;
 236         fl6.flowi6_uid = sk->sk_uid;
 237
 238         opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
 239         final_p = fl6_update_dst(&fl6, opt, &final);
 240
 241         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 242
 243         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 244         if (IS_ERR(dst)) {
 245                 err = PTR_ERR(dst);
 246                 goto failure;
 247         }
 248
 249         if (!saddr) {
 250                 saddr = &fl6.saddr;
 251                 sk->sk_v6_rcv_saddr = *saddr;
 252         }
 253
 254         /* set the source address */
 255         np->saddr = *saddr;
 256         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 257
 258         sk->sk_gso_type = SKB_GSO_TCPV6;
 259         ip6_dst_store(sk, dst, NULL, NULL);
 260
 261         if (tcp_death_row.sysctl_tw_recycle &&
 262             !tp->rx_opt.ts_recent_stamp &&
 263             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 264                 tcp_fetch_timewait_stamp(sk, dst);
 265
 266         icsk->icsk_ext_hdr_len = 0;
 267         if (opt)
 268                 icsk->icsk_ext_hdr_len = opt->opt_flen +
 269                                          opt->opt_nflen;
 270
 271         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 272
 273         inet->inet_dport = usin->sin6_port;
 274
 275         tcp_set_state(sk, TCP_SYN_SENT);
 276         err = inet6_hash_connect(&tcp_death_row, sk);
 277         if (err)
 278                 goto late_failure;
 279
 280         sk_set_txhash(sk);
 281
 282         if (!tp->write_seq && likely(!tp->repair))
 283                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 284                                                              sk->sk_v6_daddr.s6_addr32,
 285                                                              inet->inet_sport,
 286                                                              inet->inet_dport);
 287
 288         err = tcp_connect(sk);
 289         if (err)
 290                 goto late_failure;
 291
 292         return 0;
 293
 294 late_failure:
 295         tcp_set_state(sk, TCP_CLOSE);
 296         __sk_dst_reset(sk);
 297 failure:
 298         inet->inet_dport = 0;
 299         sk->sk_route_caps = 0;
 300         return err;
 301 }
 302
 303 static void tcp_v6_mtu_reduced(struct sock *sk)
 304 {
 305         struct dst_entry *dst;
 306
 307         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 308                 return;
 309
 310         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 311         if (!dst)
 312                 return;
 313
 314         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 315                 tcp_sync_mss(sk, dst_mtu(dst));
 316                 tcp_simple_retransmit(sk);
 317         }
 318 }
 319
 320 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 321                 u8 type, u8 code, int offset, __be32 info)
 322 {
 323         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 324         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 325         struct net *net = dev_net(skb->dev);
 326         struct request_sock *fastopen;
 327         struct ipv6_pinfo *np;
 328         struct tcp_sock *tp;
 329         __u32 seq, snd_una;
 330         struct sock *sk;
 331         bool fatal;
 332         int err;
 333
 334         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 335                                         &hdr->daddr, th->dest,
 336                                         &hdr->saddr, ntohs(th->source),
 337                                         skb->dev->ifindex);
 338
 339         if (!sk) {
 340                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 341                                   ICMP6_MIB_INERRORS);
 342                 return;
 343         }
 344
 345         if (sk->sk_state == TCP_TIME_WAIT) {
 346                 inet_twsk_put(inet_twsk(sk));
 347                 return;
 348         }
 349         seq = ntohl(th->seq);
 350         fatal = icmpv6_err_convert(type, code, &err);
 351         if (sk->sk_state == TCP_NEW_SYN_RECV)
 352                 return tcp_req_err(sk, seq, fatal);
 353
 354         bh_lock_sock(sk);
 355         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 356                 __NET_INC_STATS(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(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(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
 407         /* Might be for an request_sock */
 408         switch (sk->sk_state) {
 409         case TCP_SYN_SENT:
 410         case TCP_SYN_RECV:
 411                 /* Only in fast or simultaneous open. If a fast open socket is
 412                  * is already accepted it is treated as a connected one below.
 413                  */
 414                 if (fastopen && !fastopen->sk)
 415                         break;
 416
 417                 if (!sock_owned_by_user(sk)) {
 418                         sk->sk_err = err;
 419                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 420
 421                         tcp_done(sk);
 422                 } else
 423                         sk->sk_err_soft = err;
 424                 goto out;
 425         }
 426
 427         if (!sock_owned_by_user(sk) && np->recverr) {
 428                 sk->sk_err = err;
 429                 sk->sk_error_report(sk);
 430         } else
 431                 sk->sk_err_soft = err;
 432
 433 out:
 434         bh_unlock_sock(sk);
 435         sock_put(sk);
 436 }
 437
 438
 439 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 440                               struct flowi *fl,
 441                               struct request_sock *req,
 442                               struct tcp_fastopen_cookie *foc,
 443                               enum tcp_synack_type synack_type)
 444 {
 445         struct inet_request_sock *ireq = inet_rsk(req);
 446         struct ipv6_pinfo *np = inet6_sk(sk);
 447         struct ipv6_txoptions *opt;
 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,
 454                                                IPPROTO_TCP)) == NULL)
 455                 goto done;
 456
 457         skb = tcp_make_synack(sk, dst, req, foc, synack_type);
 458
 459         if (skb) {
 460                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 461                                     &ireq->ir_v6_rmt_addr);
 462
 463                 fl6->daddr = ireq->ir_v6_rmt_addr;
 464                 if (np->repflow && ireq->pktopts)
 465                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 466
 467                 rcu_read_lock();
 468                 opt = ireq->ipv6_opt;
 469                 if (!opt)
 470                         opt = rcu_dereference(np->opt);
 471                 err = ip6_xmit(sk, skb, fl6, opt, np->tclass);
 472                 rcu_read_unlock();
 473                 err = net_xmit_eval(err);
 474         }
 475
 476 done:
 477         return err;
 478 }
 479
 480
 481 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 482 {
 483         kfree(inet_rsk(req)->ipv6_opt);
 484         kfree_skb(inet_rsk(req)->pktopts);
 485 }
 486
 487 #ifdef CONFIG_TCP_MD5SIG
 488 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 489                                                    const struct in6_addr *addr)
 490 {
 491         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 492 }
 493
 494 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 495                                                 const struct sock *addr_sk)
 496 {
 497         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 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_headers(struct tcp_md5sig_pool *hp,
 535                                    const struct in6_addr *daddr,
 536                                    const struct in6_addr *saddr,
 537                                    const struct tcphdr *th, int nbytes)
 538 {
 539         struct tcp6_pseudohdr *bp;
 540         struct scatterlist sg;
 541         struct tcphdr *_th;
 542
 543         bp = hp->scratch;
 544         /* 1. TCP pseudo-header (RFC2460) */
 545         bp->saddr = *saddr;
 546         bp->daddr = *daddr;
 547         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 548         bp->len = cpu_to_be32(nbytes);
 549
 550         _th = (struct tcphdr *)(bp + 1);
 551         memcpy(_th, th, sizeof(*th));
 552         _th->check = 0;
 553
 554         sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
 555         ahash_request_set_crypt(hp->md5_req, &sg, NULL,
 556                                 sizeof(*bp) + sizeof(*th));
 557         return crypto_ahash_update(hp->md5_req);
 558 }
 559
 560 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 561                                const struct in6_addr *daddr, struct in6_addr *saddr,
 562                                const struct tcphdr *th)
 563 {
 564         struct tcp_md5sig_pool *hp;
 565         struct ahash_request *req;
 566
 567         hp = tcp_get_md5sig_pool();
 568         if (!hp)
 569                 goto clear_hash_noput;
 570         req = hp->md5_req;
 571
 572         if (crypto_ahash_init(req))
 573                 goto clear_hash;
 574         if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
 575                 goto clear_hash;
 576         if (tcp_md5_hash_key(hp, key))
 577                 goto clear_hash;
 578         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 579         if (crypto_ahash_final(req))
 580                 goto clear_hash;
 581
 582         tcp_put_md5sig_pool();
 583         return 0;
 584
 585 clear_hash:
 586         tcp_put_md5sig_pool();
 587 clear_hash_noput:
 588         memset(md5_hash, 0, 16);
 589         return 1;
 590 }
 591
 592 static int tcp_v6_md5_hash_skb(char *md5_hash,
 593                                const struct tcp_md5sig_key *key,
 594                                const struct sock *sk,
 595                                const struct sk_buff *skb)
 596 {
 597         const struct in6_addr *saddr, *daddr;
 598         struct tcp_md5sig_pool *hp;
 599         struct ahash_request *req;
 600         const struct tcphdr *th = tcp_hdr(skb);
 601
 602         if (sk) { /* valid for establish/request sockets */
 603                 saddr = &sk->sk_v6_rcv_saddr;
 604                 daddr = &sk->sk_v6_daddr;
 605         } else {
 606                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 607                 saddr = &ip6h->saddr;
 608                 daddr = &ip6h->daddr;
 609         }
 610
 611         hp = tcp_get_md5sig_pool();
 612         if (!hp)
 613                 goto clear_hash_noput;
 614         req = hp->md5_req;
 615
 616         if (crypto_ahash_init(req))
 617                 goto clear_hash;
 618
 619         if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
 620                 goto clear_hash;
 621         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 622                 goto clear_hash;
 623         if (tcp_md5_hash_key(hp, key))
 624                 goto clear_hash;
 625         ahash_request_set_crypt(req, NULL, md5_hash, 0);
 626         if (crypto_ahash_final(req))
 627                 goto clear_hash;
 628
 629         tcp_put_md5sig_pool();
 630         return 0;
 631
 632 clear_hash:
 633         tcp_put_md5sig_pool();
 634 clear_hash_noput:
 635         memset(md5_hash, 0, 16);
 636         return 1;
 637 }
 638
 639 #endif
 640
 641 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 642                                     const struct sk_buff *skb)
 643 {
 644 #ifdef CONFIG_TCP_MD5SIG
 645         const __u8 *hash_location = NULL;
 646         struct tcp_md5sig_key *hash_expected;
 647         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 648         const struct tcphdr *th = tcp_hdr(skb);
 649         int genhash;
 650         u8 newhash[16];
 651
 652         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 653         hash_location = tcp_parse_md5sig_option(th);
 654
 655         /* We've parsed the options - do we have a hash? */
 656         if (!hash_expected && !hash_location)
 657                 return false;
 658
 659         if (hash_expected && !hash_location) {
 660                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 661                 return true;
 662         }
 663
 664         if (!hash_expected && hash_location) {
 665                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 666                 return true;
 667         }
 668
 669         /* check the signature */
 670         genhash = tcp_v6_md5_hash_skb(newhash,
 671                                       hash_expected,
 672                                       NULL, skb);
 673
 674         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 675                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
 676                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 677                                      genhash ? "failed" : "mismatch",
 678                                      &ip6h->saddr, ntohs(th->source),
 679                                      &ip6h->daddr, ntohs(th->dest));
 680                 return true;
 681         }
 682 #endif
 683         return false;
 684 }
 685
 686 static void tcp_v6_init_req(struct request_sock *req,
 687                             const struct sock *sk_listener,
 688                             struct sk_buff *skb)
 689 {
 690         struct inet_request_sock *ireq = inet_rsk(req);
 691         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 692
 693         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 694         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 695
 696         /* So that link locals have meaning */
 697         if (!sk_listener->sk_bound_dev_if &&
 698             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 699                 ireq->ir_iif = tcp_v6_iif(skb);
 700
 701         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 702             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 703              np->rxopt.bits.rxinfo ||
 704              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 705              np->rxopt.bits.rxohlim || np->repflow)) {
 706                 atomic_inc(&skb->users);
 707                 ireq->pktopts = skb;
 708         }
 709 }
 710
 711 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 712                                           struct flowi *fl,
 713                                           const struct request_sock *req,
 714                                           bool *strict)
 715 {
 716         if (strict)
 717                 *strict = true;
 718         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 719 }
 720
 721 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 722         .family         =       AF_INET6,
 723         .obj_size       =       sizeof(struct tcp6_request_sock),
 724         .rtx_syn_ack    =       tcp_rtx_synack,
 725         .send_ack       =       tcp_v6_reqsk_send_ack,
 726         .destructor     =       tcp_v6_reqsk_destructor,
 727         .send_reset     =       tcp_v6_send_reset,
 728         .syn_ack_timeout =      tcp_syn_ack_timeout,
 729 };
 730
 731 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 732         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 733                                 sizeof(struct ipv6hdr),
 734 #ifdef CONFIG_TCP_MD5SIG
 735         .req_md5_lookup =       tcp_v6_md5_lookup,
 736         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 737 #endif
 738         .init_req       =       tcp_v6_init_req,
 739 #ifdef CONFIG_SYN_COOKIES
 740         .cookie_init_seq =      cookie_v6_init_sequence,
 741 #endif
 742         .route_req      =       tcp_v6_route_req,
 743         .init_seq       =       tcp_v6_init_sequence,
 744         .send_synack    =       tcp_v6_send_synack,
 745 };
 746
 747 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 748                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 749                                  int oif, struct tcp_md5sig_key *key, int rst,
 750                                  u8 tclass, __be32 label)
 751 {
 752         const struct tcphdr *th = tcp_hdr(skb);
 753         struct tcphdr *t1;
 754         struct sk_buff *buff;
 755         struct flowi6 fl6;
 756         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 757         struct sock *ctl_sk = net->ipv6.tcp_sk;
 758         unsigned int tot_len = sizeof(struct tcphdr);
 759         struct dst_entry *dst;
 760         __be32 *topt;
 761
 762         if (tsecr)
 763                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 764 #ifdef CONFIG_TCP_MD5SIG
 765         if (key)
 766                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 767 #endif
 768
 769         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 770                          GFP_ATOMIC);
 771         if (!buff)
 772                 return;
 773
 774         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 775
 776         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 777         skb_reset_transport_header(buff);
 778
 779         /* Swap the send and the receive. */
 780         memset(t1, 0, sizeof(*t1));
 781         t1->dest = th->source;
 782         t1->source = th->dest;
 783         t1->doff = tot_len / 4;
 784         t1->seq = htonl(seq);
 785         t1->ack_seq = htonl(ack);
 786         t1->ack = !rst || !th->ack;
 787         t1->rst = rst;
 788         t1->window = htons(win);
 789
 790         topt = (__be32 *)(t1 + 1);
 791
 792         if (tsecr) {
 793                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 794                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 795                 *topt++ = htonl(tsval);
 796                 *topt++ = htonl(tsecr);
 797         }
 798
 799 #ifdef CONFIG_TCP_MD5SIG
 800         if (key) {
 801                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 802                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 803                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 804                                     &ipv6_hdr(skb)->saddr,
 805                                     &ipv6_hdr(skb)->daddr, t1);
 806         }
 807 #endif
 808
 809         memset(&fl6, 0, sizeof(fl6));
 810         fl6.daddr = ipv6_hdr(skb)->saddr;
 811         fl6.saddr = ipv6_hdr(skb)->daddr;
 812         fl6.flowlabel = label;
 813
 814         buff->ip_summed = CHECKSUM_PARTIAL;
 815         buff->csum = 0;
 816
 817         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 818
 819         fl6.flowi6_proto = IPPROTO_TCP;
 820         if (rt6_need_strict(&fl6.daddr) && !oif)
 821                 fl6.flowi6_oif = tcp_v6_iif(skb);
 822         else
 823                 fl6.flowi6_oif = oif ? : skb->skb_iif;
 824
 825         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 826         fl6.fl6_dport = t1->dest;
 827         fl6.fl6_sport = t1->source;
 828         fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
 829         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 830
 831         /* Pass a socket to ip6_dst_lookup either it is for RST
 832          * Underlying function will use this to retrieve the network
 833          * namespace
 834          */
 835         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 836         if (!IS_ERR(dst)) {
 837                 skb_dst_set(buff, dst);
 838                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 839                 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 840                 if (rst)
 841                         TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
 842                 return;
 843         }
 844
 845         kfree_skb(buff);
 846 }
 847
 848 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 849 {
 850         const struct tcphdr *th = tcp_hdr(skb);
 851         u32 seq = 0, ack_seq = 0;
 852         struct tcp_md5sig_key *key = NULL;
 853 #ifdef CONFIG_TCP_MD5SIG
 854         const __u8 *hash_location = NULL;
 855         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 856         unsigned char newhash[16];
 857         int genhash;
 858         struct sock *sk1 = NULL;
 859 #endif
 860         int oif;
 861
 862         if (th->rst)
 863                 return;
 864
 865         /* If sk not NULL, it means we did a successful lookup and incoming
 866          * route had to be correct. prequeue might have dropped our dst.
 867          */
 868         if (!sk && !ipv6_unicast_destination(skb))
 869                 return;
 870
 871 #ifdef CONFIG_TCP_MD5SIG
 872         rcu_read_lock();
 873         hash_location = tcp_parse_md5sig_option(th);
 874         if (sk && sk_fullsock(sk)) {
 875                 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
 876         } else if (hash_location) {
 877                 /*
 878                  * active side is lost. Try to find listening socket through
 879                  * source port, and then find md5 key through listening socket.
 880                  * we are not loose security here:
 881                  * Incoming packet is checked with md5 hash with finding key,
 882                  * no RST generated if md5 hash doesn't match.
 883                  */
 884                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 885                                            &tcp_hashinfo, NULL, 0,
 886                                            &ipv6h->saddr,
 887                                            th->source, &ipv6h->daddr,
 888                                            ntohs(th->source), tcp_v6_iif(skb));
 889                 if (!sk1)
 890                         goto out;
 891
 892                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 893                 if (!key)
 894                         goto out;
 895
 896                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 897                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 898                         goto out;
 899         }
 900 #endif
 901
 902         if (th->ack)
 903                 seq = ntohl(th->ack_seq);
 904         else
 905                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 906                           (th->doff << 2);
 907
 908         oif = sk ? sk->sk_bound_dev_if : 0;
 909         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 910
 911 #ifdef CONFIG_TCP_MD5SIG
 912 out:
 913         rcu_read_unlock();
 914 #endif
 915 }
 916
 917 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 918                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 919                             struct tcp_md5sig_key *key, u8 tclass,
 920                             __be32 label)
 921 {
 922         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 923                              tclass, label);
 924 }
 925
 926 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 927 {
 928         struct inet_timewait_sock *tw = inet_twsk(sk);
 929         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 930
 931         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 932                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 933                         tcp_time_stamp + tcptw->tw_ts_offset,
 934                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 935                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 936
 937         inet_twsk_put(tw);
 938 }
 939
 940 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 941                                   struct request_sock *req)
 942 {
 943         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 944          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 945          */
 946         /* RFC 7323 2.3
 947          * The window field (SEG.WND) of every outgoing segment, with the
 948          * exception of <SYN> segments, MUST be right-shifted by
 949          * Rcv.Wind.Shift bits:
 950          */
 951         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 952                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 953                         tcp_rsk(req)->rcv_nxt,
 954                         req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
 955                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 956                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 957                         0, 0);
 958 }
 959
 960
 961 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
 962 {
 963 #ifdef CONFIG_SYN_COOKIES
 964         const struct tcphdr *th = tcp_hdr(skb);
 965
 966         if (!th->syn)
 967                 sk = cookie_v6_check(sk, skb);
 968 #endif
 969         return sk;
 970 }
 971
 972 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 973 {
 974         if (skb->protocol == htons(ETH_P_IP))
 975                 return tcp_v4_conn_request(sk, skb);
 976
 977         if (!ipv6_unicast_destination(skb))
 978                 goto drop;
 979
 980         return tcp_conn_request(&tcp6_request_sock_ops,
 981                                 &tcp_request_sock_ipv6_ops, sk, skb);
 982
 983 drop:
 984         tcp_listendrop(sk);
 985         return 0; /* don't send reset */
 986 }
 987
 988 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 989                                          struct request_sock *req,
 990                                          struct dst_entry *dst,
 991                                          struct request_sock *req_unhash,
 992                                          bool *own_req)
 993 {
 994         struct inet_request_sock *ireq;
 995         struct ipv6_pinfo *newnp;
 996         const struct ipv6_pinfo *np = inet6_sk(sk);
 997         struct ipv6_txoptions *opt;
 998         struct tcp6_sock *newtcp6sk;
 999         struct inet_sock *newinet;
1000         struct tcp_sock *newtp;
1001         struct sock *newsk;
1002 #ifdef CONFIG_TCP_MD5SIG
1003         struct tcp_md5sig_key *key;
1004 #endif
1005         struct flowi6 fl6;
1006
1007         if (skb->protocol == htons(ETH_P_IP)) {
1008                 /*
1009                  *      v6 mapped
1010                  */
1011
1012                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1013                                              req_unhash, own_req);
1014
1015                 if (!newsk)
1016                         return NULL;
1017
1018                 newtcp6sk = (struct tcp6_sock *)newsk;
1019                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1020
1021                 newinet = inet_sk(newsk);
1022                 newnp = inet6_sk(newsk);
1023                 newtp = tcp_sk(newsk);
1024
1025                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1026
1027                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1028
1029                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1030                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1031 #ifdef CONFIG_TCP_MD5SIG
1032                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1033 #endif
1034
1035                 newnp->ipv6_ac_list = NULL;
1036                 newnp->ipv6_fl_list = NULL;
1037                 newnp->pktoptions  = NULL;
1038                 newnp->opt         = NULL;
1039                 newnp->mcast_oif   = tcp_v6_iif(skb);
1040                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1041                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1042                 if (np->repflow)
1043                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1044
1045                 /*
1046                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1047                  * here, tcp_create_openreq_child now does this for us, see the comment in
1048                  * that function for the gory details. -acme
1049                  */
1050
1051                 /* It is tricky place. Until this moment IPv4 tcp
1052                    worked with IPv6 icsk.icsk_af_ops.
1053                    Sync it now.
1054                  */
1055                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1056
1057                 return newsk;
1058         }
1059
1060         ireq = inet_rsk(req);
1061
1062         if (sk_acceptq_is_full(sk))
1063                 goto out_overflow;
1064
1065         if (!dst) {
1066                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1067                 if (!dst)
1068                         goto out;
1069         }
1070
1071         newsk = tcp_create_openreq_child(sk, req, skb);
1072         if (!newsk)
1073                 goto out_nonewsk;
1074
1075         /*
1076          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1077          * count here, tcp_create_openreq_child now does this for us, see the
1078          * comment in that function for the gory details. -acme
1079          */
1080
1081         newsk->sk_gso_type = SKB_GSO_TCPV6;
1082         ip6_dst_store(newsk, dst, NULL, NULL);
1083         inet6_sk_rx_dst_set(newsk, skb);
1084
1085         newtcp6sk = (struct tcp6_sock *)newsk;
1086         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1087
1088         newtp = tcp_sk(newsk);
1089         newinet = inet_sk(newsk);
1090         newnp = inet6_sk(newsk);
1091
1092         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1093
1094         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1095         newnp->saddr = ireq->ir_v6_loc_addr;
1096         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1097         newsk->sk_bound_dev_if = ireq->ir_iif;
1098
1099         /* Now IPv6 options...
1100
1101            First: no IPv4 options.
1102          */
1103         newinet->inet_opt = NULL;
1104         newnp->ipv6_ac_list = NULL;
1105         newnp->ipv6_fl_list = NULL;
1106
1107         /* Clone RX bits */
1108         newnp->rxopt.all = np->rxopt.all;
1109
1110         newnp->pktoptions = NULL;
1111         newnp->opt        = NULL;
1112         newnp->mcast_oif  = tcp_v6_iif(skb);
1113         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1114         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1115         if (np->repflow)
1116                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1117
1118         /* Clone native IPv6 options from listening socket (if any)
1119
1120            Yes, keeping reference count would be much more clever,
1121            but we make one more one thing there: reattach optmem
1122            to newsk.
1123          */
1124         opt = ireq->ipv6_opt;
1125         if (!opt)
1126                 opt = rcu_dereference(np->opt);
1127         if (opt) {
1128                 opt = ipv6_dup_options(newsk, opt);
1129                 RCU_INIT_POINTER(newnp->opt, opt);
1130         }
1131         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1132         if (opt)
1133                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1134                                                     opt->opt_flen;
1135
1136         tcp_ca_openreq_child(newsk, dst);
1137
1138         tcp_sync_mss(newsk, dst_mtu(dst));
1139         newtp->advmss = dst_metric_advmss(dst);
1140         if (tcp_sk(sk)->rx_opt.user_mss &&
1141             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1142                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1143
1144         tcp_initialize_rcv_mss(newsk);
1145
1146         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1147         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1148
1149 #ifdef CONFIG_TCP_MD5SIG
1150         /* Copy over the MD5 key from the original socket */
1151         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1152         if (key) {
1153                 /* We're using one, so create a matching key
1154                  * on the newsk structure. If we fail to get
1155                  * memory, then we end up not copying the key
1156                  * across. Shucks.
1157                  */
1158                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1159                                AF_INET6, key->key, key->keylen,
1160                                sk_gfp_mask(sk, GFP_ATOMIC));
1161         }
1162 #endif
1163
1164         if (__inet_inherit_port(sk, newsk) < 0) {
1165                 inet_csk_prepare_forced_close(newsk);
1166                 tcp_done(newsk);
1167                 goto out;
1168         }
1169         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1170         if (*own_req) {
1171                 tcp_move_syn(newtp, req);
1172
1173                 /* Clone pktoptions received with SYN, if we own the req */
1174                 if (ireq->pktopts) {
1175                         newnp->pktoptions = skb_clone(ireq->pktopts,
1176                                                       sk_gfp_mask(sk, GFP_ATOMIC));
1177                         consume_skb(ireq->pktopts);
1178                         ireq->pktopts = NULL;
1179                         if (newnp->pktoptions)
1180                                 skb_set_owner_r(newnp->pktoptions, newsk);
1181                 }
1182         }
1183
1184         return newsk;
1185
1186 out_overflow:
1187         __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1188 out_nonewsk:
1189         dst_release(dst);
1190 out:
1191         tcp_listendrop(sk);
1192         return NULL;
1193 }
1194
1195 static void tcp_v6_restore_cb(struct sk_buff *skb)
1196 {
1197         /* We need to move header back to the beginning if xfrm6_policy_check()
1198          * and tcp_v6_fill_cb() are going to be called again.
1199          * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1200          */
1201         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1202                 sizeof(struct inet6_skb_parm));
1203 }
1204
1205 /* The socket must have it's spinlock held when we get
1206  * here, unless it is a TCP_LISTEN socket.
1207  *
1208  * We have a potential double-lock case here, so even when
1209  * doing backlog processing we use the BH locking scheme.
1210  * This is because we cannot sleep with the original spinlock
1211  * held.
1212  */
1213 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1214 {
1215         struct ipv6_pinfo *np = inet6_sk(sk);
1216         struct tcp_sock *tp;
1217         struct sk_buff *opt_skb = NULL;
1218
1219         /* Imagine: socket is IPv6. IPv4 packet arrives,
1220            goes to IPv4 receive handler and backlogged.
1221            From backlog it always goes here. Kerboom...
1222            Fortunately, tcp_rcv_established and rcv_established
1223            handle them correctly, but it is not case with
1224            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1225          */
1226
1227         if (skb->protocol == htons(ETH_P_IP))
1228                 return tcp_v4_do_rcv(sk, skb);
1229
1230         if (sk_filter(sk, skb))
1231                 goto discard;
1232
1233         /*
1234          *      socket locking is here for SMP purposes as backlog rcv
1235          *      is currently called with bh processing disabled.
1236          */
1237
1238         /* Do Stevens' IPV6_PKTOPTIONS.
1239
1240            Yes, guys, it is the only place in our code, where we
1241            may make it not affecting IPv4.
1242            The rest of code is protocol independent,
1243            and I do not like idea to uglify IPv4.
1244
1245            Actually, all the idea behind IPV6_PKTOPTIONS
1246            looks not very well thought. For now we latch
1247            options, received in the last packet, enqueued
1248            by tcp. Feel free to propose better solution.
1249                                                --ANK (980728)
1250          */
1251         if (np->rxopt.all)
1252                 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1253
1254         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1255                 struct dst_entry *dst = sk->sk_rx_dst;
1256
1257                 sock_rps_save_rxhash(sk, skb);
1258                 sk_mark_napi_id(sk, skb);
1259                 if (dst) {
1260                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1261                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1262                                 dst_release(dst);
1263                                 sk->sk_rx_dst = NULL;
1264                         }
1265                 }
1266
1267                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1268                 if (opt_skb)
1269                         goto ipv6_pktoptions;
1270                 return 0;
1271         }
1272
1273         if (tcp_checksum_complete(skb))
1274                 goto csum_err;
1275
1276         if (sk->sk_state == TCP_LISTEN) {
1277                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1278
1279                 if (!nsk)
1280                         goto discard;
1281
1282                 if (nsk != sk) {
1283                         sock_rps_save_rxhash(nsk, skb);
1284                         sk_mark_napi_id(nsk, skb);
1285                         if (tcp_child_process(sk, nsk, skb))
1286                                 goto reset;
1287                         if (opt_skb)
1288                                 __kfree_skb(opt_skb);
1289                         return 0;
1290                 }
1291         } else
1292                 sock_rps_save_rxhash(sk, skb);
1293
1294         if (tcp_rcv_state_process(sk, skb))
1295                 goto reset;
1296         if (opt_skb)
1297                 goto ipv6_pktoptions;
1298         return 0;
1299
1300 reset:
1301         tcp_v6_send_reset(sk, skb);
1302 discard:
1303         if (opt_skb)
1304                 __kfree_skb(opt_skb);
1305         kfree_skb(skb);
1306         return 0;
1307 csum_err:
1308         TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1309         TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1310         goto discard;
1311
1312
1313 ipv6_pktoptions:
1314         /* Do you ask, what is it?
1315
1316            1. skb was enqueued by tcp.
1317            2. skb is added to tail of read queue, rather than out of order.
1318            3. socket is not in passive state.
1319            4. Finally, it really contains options, which user wants to receive.
1320          */
1321         tp = tcp_sk(sk);
1322         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1323             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1324                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1325                         np->mcast_oif = tcp_v6_iif(opt_skb);
1326                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1327                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1328                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1329                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1330                 if (np->repflow)
1331                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1332                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1333                         skb_set_owner_r(opt_skb, sk);
1334                         tcp_v6_restore_cb(opt_skb);
1335                         opt_skb = xchg(&np->pktoptions, opt_skb);
1336                 } else {
1337                         __kfree_skb(opt_skb);
1338                         opt_skb = xchg(&np->pktoptions, NULL);
1339                 }
1340         }
1341
1342         kfree_skb(opt_skb);
1343         return 0;
1344 }
1345
1346 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1347                            const struct tcphdr *th)
1348 {
1349         /* This is tricky: we move IP6CB at its correct location into
1350          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1351          * _decode_session6() uses IP6CB().
1352          * barrier() makes sure compiler won't play aliasing games.
1353          */
1354         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1355                 sizeof(struct inet6_skb_parm));
1356         barrier();
1357
1358         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1359         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1360                                     skb->len - th->doff*4);
1361         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1362         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1363         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1364         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1365         TCP_SKB_CB(skb)->sacked = 0;
1366 }
1367
1368 static int tcp_v6_rcv(struct sk_buff *skb)
1369 {
1370         const struct tcphdr *th;
1371         const struct ipv6hdr *hdr;
1372         bool refcounted;
1373         struct sock *sk;
1374         int ret;
1375         struct net *net = dev_net(skb->dev);
1376
1377         if (skb->pkt_type != PACKET_HOST)
1378                 goto discard_it;
1379
1380         /*
1381          *      Count it even if it's bad.
1382          */
1383         __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1384
1385         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1386                 goto discard_it;
1387
1388         th = (const struct tcphdr *)skb->data;
1389
1390         if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1391                 goto bad_packet;
1392         if (!pskb_may_pull(skb, th->doff*4))
1393                 goto discard_it;
1394
1395         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1396                 goto csum_error;
1397
1398         th = (const struct tcphdr *)skb->data;
1399         hdr = ipv6_hdr(skb);
1400
1401 lookup:
1402         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1403                                 th->source, th->dest, inet6_iif(skb),
1404                                 &refcounted);
1405         if (!sk)
1406                 goto no_tcp_socket;
1407
1408 process:
1409         if (sk->sk_state == TCP_TIME_WAIT)
1410                 goto do_time_wait;
1411
1412         if (sk->sk_state == TCP_NEW_SYN_RECV) {
1413                 struct request_sock *req = inet_reqsk(sk);
1414                 struct sock *nsk;
1415
1416                 sk = req->rsk_listener;
1417                 tcp_v6_fill_cb(skb, hdr, th);
1418                 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1419                         sk_drops_add(sk, skb);
1420                         reqsk_put(req);
1421                         goto discard_it;
1422                 }
1423                 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1424                         inet_csk_reqsk_queue_drop_and_put(sk, req);
1425                         goto lookup;
1426                 }
1427                 sock_hold(sk);
1428                 refcounted = true;
1429                 nsk = tcp_check_req(sk, skb, req, false);
1430                 if (!nsk) {
1431                         reqsk_put(req);
1432                         goto discard_and_relse;
1433                 }
1434                 if (nsk == sk) {
1435                         reqsk_put(req);
1436                         tcp_v6_restore_cb(skb);
1437                 } else if (tcp_child_process(sk, nsk, skb)) {
1438                         tcp_v6_send_reset(nsk, skb);
1439                         goto discard_and_relse;
1440                 } else {
1441                         sock_put(sk);
1442                         return 0;
1443                 }
1444         }
1445         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1446                 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1447                 goto discard_and_relse;
1448         }
1449
1450         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1451                 goto discard_and_relse;
1452
1453         tcp_v6_fill_cb(skb, hdr, th);
1454
1455         if (tcp_v6_inbound_md5_hash(sk, skb))
1456                 goto discard_and_relse;
1457
1458         if (sk_filter(sk, skb))
1459                 goto discard_and_relse;
1460
1461         skb->dev = NULL;
1462
1463         if (sk->sk_state == TCP_LISTEN) {
1464                 ret = tcp_v6_do_rcv(sk, skb);
1465                 goto put_and_return;
1466         }
1467
1468         sk_incoming_cpu_update(sk);
1469
1470         bh_lock_sock_nested(sk);
1471         tcp_segs_in(tcp_sk(sk), skb);
1472         ret = 0;
1473         if (!sock_owned_by_user(sk)) {
1474                 if (!tcp_prequeue(sk, skb))
1475                         ret = tcp_v6_do_rcv(sk, skb);
1476         } else if (tcp_add_backlog(sk, skb)) {
1477                 goto discard_and_relse;
1478         }
1479         bh_unlock_sock(sk);
1480
1481 put_and_return:
1482         if (refcounted)
1483                 sock_put(sk);
1484         return ret ? -1 : 0;
1485
1486 no_tcp_socket:
1487         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1488                 goto discard_it;
1489
1490         tcp_v6_fill_cb(skb, hdr, th);
1491
1492         if (tcp_checksum_complete(skb)) {
1493 csum_error:
1494                 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1495 bad_packet:
1496                 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1497         } else {
1498                 tcp_v6_send_reset(NULL, skb);
1499         }
1500
1501 discard_it:
1502         kfree_skb(skb);
1503         return 0;
1504
1505 discard_and_relse:
1506         sk_drops_add(sk, skb);
1507         if (refcounted)
1508                 sock_put(sk);
1509         goto discard_it;
1510
1511 do_time_wait:
1512         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1513                 inet_twsk_put(inet_twsk(sk));
1514                 goto discard_it;
1515         }
1516
1517         tcp_v6_fill_cb(skb, hdr, th);
1518
1519         if (tcp_checksum_complete(skb)) {
1520                 inet_twsk_put(inet_twsk(sk));
1521                 goto csum_error;
1522         }
1523
1524         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1525         case TCP_TW_SYN:
1526         {
1527                 struct sock *sk2;
1528
1529                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1530                                             skb, __tcp_hdrlen(th),
1531                                             &ipv6_hdr(skb)->saddr, th->source,
1532                                             &ipv6_hdr(skb)->daddr,
1533                                             ntohs(th->dest), tcp_v6_iif(skb));
1534                 if (sk2) {
1535                         struct inet_timewait_sock *tw = inet_twsk(sk);
1536                         inet_twsk_deschedule_put(tw);
1537                         sk = sk2;
1538                         tcp_v6_restore_cb(skb);
1539                         refcounted = false;
1540                         goto process;
1541                 }
1542                 /* Fall through to ACK */
1543         }
1544         case TCP_TW_ACK:
1545                 tcp_v6_timewait_ack(sk, skb);
1546                 break;
1547         case TCP_TW_RST:
1548                 tcp_v6_restore_cb(skb);
1549                 tcp_v6_send_reset(sk, skb);
1550                 inet_twsk_deschedule_put(inet_twsk(sk));
1551                 goto discard_it;
1552         case TCP_TW_SUCCESS:
1553                 ;
1554         }
1555         goto discard_it;
1556 }
1557
1558 static void tcp_v6_early_demux(struct sk_buff *skb)
1559 {
1560         const struct ipv6hdr *hdr;
1561         const struct tcphdr *th;
1562         struct sock *sk;
1563
1564         if (skb->pkt_type != PACKET_HOST)
1565                 return;
1566
1567         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1568                 return;
1569
1570         hdr = ipv6_hdr(skb);
1571         th = tcp_hdr(skb);
1572
1573         if (th->doff < sizeof(struct tcphdr) / 4)
1574                 return;
1575
1576         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1577         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1578                                         &hdr->saddr, th->source,
1579                                         &hdr->daddr, ntohs(th->dest),
1580                                         inet6_iif(skb));
1581         if (sk) {
1582                 skb->sk = sk;
1583                 skb->destructor = sock_edemux;
1584                 if (sk_fullsock(sk)) {
1585                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1586
1587                         if (dst)
1588                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1589                         if (dst &&
1590                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1591                                 skb_dst_set_noref(skb, dst);
1592                 }
1593         }
1594 }
1595
1596 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1597         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1598         .twsk_unique    = tcp_twsk_unique,
1599         .twsk_destructor = tcp_twsk_destructor,
1600 };
1601
1602 static const struct inet_connection_sock_af_ops ipv6_specific = {
1603         .queue_xmit        = inet6_csk_xmit,
1604         .send_check        = tcp_v6_send_check,
1605         .rebuild_header    = inet6_sk_rebuild_header,
1606         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1607         .conn_request      = tcp_v6_conn_request,
1608         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1609         .net_header_len    = sizeof(struct ipv6hdr),
1610         .net_frag_header_len = sizeof(struct frag_hdr),
1611         .setsockopt        = ipv6_setsockopt,
1612         .getsockopt        = ipv6_getsockopt,
1613         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1614         .sockaddr_len      = sizeof(struct sockaddr_in6),
1615         .bind_conflict     = inet6_csk_bind_conflict,
1616 #ifdef CONFIG_COMPAT
1617         .compat_setsockopt = compat_ipv6_setsockopt,
1618         .compat_getsockopt = compat_ipv6_getsockopt,
1619 #endif
1620         .mtu_reduced       = tcp_v6_mtu_reduced,
1621 };
1622
1623 #ifdef CONFIG_TCP_MD5SIG
1624 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1625         .md5_lookup     =       tcp_v6_md5_lookup,
1626         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1627         .md5_parse      =       tcp_v6_parse_md5_keys,
1628 };
1629 #endif
1630
1631 /*
1632  *      TCP over IPv4 via INET6 API
1633  */
1634 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1635         .queue_xmit        = ip_queue_xmit,
1636         .send_check        = tcp_v4_send_check,
1637         .rebuild_header    = inet_sk_rebuild_header,
1638         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1639         .conn_request      = tcp_v6_conn_request,
1640         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1641         .net_header_len    = sizeof(struct iphdr),
1642         .setsockopt        = ipv6_setsockopt,
1643         .getsockopt        = ipv6_getsockopt,
1644         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1645         .sockaddr_len      = sizeof(struct sockaddr_in6),
1646         .bind_conflict     = inet6_csk_bind_conflict,
1647 #ifdef CONFIG_COMPAT
1648         .compat_setsockopt = compat_ipv6_setsockopt,
1649         .compat_getsockopt = compat_ipv6_getsockopt,
1650 #endif
1651         .mtu_reduced       = tcp_v4_mtu_reduced,
1652 };
1653
1654 #ifdef CONFIG_TCP_MD5SIG
1655 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1656         .md5_lookup     =       tcp_v4_md5_lookup,
1657         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1658         .md5_parse      =       tcp_v6_parse_md5_keys,
1659 };
1660 #endif
1661
1662 /* NOTE: A lot of things set to zero explicitly by call to
1663  *       sk_alloc() so need not be done here.
1664  */
1665 static int tcp_v6_init_sock(struct sock *sk)
1666 {
1667         struct inet_connection_sock *icsk = inet_csk(sk);
1668
1669         tcp_init_sock(sk);
1670
1671         icsk->icsk_af_ops = &ipv6_specific;
1672
1673 #ifdef CONFIG_TCP_MD5SIG
1674         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1675 #endif
1676
1677         return 0;
1678 }
1679
1680 static void tcp_v6_destroy_sock(struct sock *sk)
1681 {
1682         tcp_v4_destroy_sock(sk);
1683         inet6_destroy_sock(sk);
1684 }
1685
1686 #ifdef CONFIG_PROC_FS
1687 /* Proc filesystem TCPv6 sock list dumping. */
1688 static void get_openreq6(struct seq_file *seq,
1689                          const struct request_sock *req, int i)
1690 {
1691         long ttd = req->rsk_timer.expires - jiffies;
1692         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1693         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1694
1695         if (ttd < 0)
1696                 ttd = 0;
1697
1698         seq_printf(seq,
1699                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1700                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1701                    i,
1702                    src->s6_addr32[0], src->s6_addr32[1],
1703                    src->s6_addr32[2], src->s6_addr32[3],
1704                    inet_rsk(req)->ir_num,
1705                    dest->s6_addr32[0], dest->s6_addr32[1],
1706                    dest->s6_addr32[2], dest->s6_addr32[3],
1707                    ntohs(inet_rsk(req)->ir_rmt_port),
1708                    TCP_SYN_RECV,
1709                    0, 0, /* could print option size, but that is af dependent. */
1710                    1,   /* timers active (only the expire timer) */
1711                    jiffies_to_clock_t(ttd),
1712                    req->num_timeout,
1713                    from_kuid_munged(seq_user_ns(seq),
1714                                     sock_i_uid(req->rsk_listener)),
1715                    0,  /* non standard timer */
1716                    0, /* open_requests have no inode */
1717                    0, req);
1718 }
1719
1720 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1721 {
1722         const struct in6_addr *dest, *src;
1723         __u16 destp, srcp;
1724         int timer_active;
1725         unsigned long timer_expires;
1726         const struct inet_sock *inet = inet_sk(sp);
1727         const struct tcp_sock *tp = tcp_sk(sp);
1728         const struct inet_connection_sock *icsk = inet_csk(sp);
1729         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1730         int rx_queue;
1731         int state;
1732
1733         dest  = &sp->sk_v6_daddr;
1734         src   = &sp->sk_v6_rcv_saddr;
1735         destp = ntohs(inet->inet_dport);
1736         srcp  = ntohs(inet->inet_sport);
1737
1738         if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1739             icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
1740             icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1741                 timer_active    = 1;
1742                 timer_expires   = icsk->icsk_timeout;
1743         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1744                 timer_active    = 4;
1745                 timer_expires   = icsk->icsk_timeout;
1746         } else if (timer_pending(&sp->sk_timer)) {
1747                 timer_active    = 2;
1748                 timer_expires   = sp->sk_timer.expires;
1749         } else {
1750                 timer_active    = 0;
1751                 timer_expires = jiffies;
1752         }
1753
1754         state = sk_state_load(sp);
1755         if (state == TCP_LISTEN)
1756                 rx_queue = sp->sk_ack_backlog;
1757         else
1758                 /* Because we don't lock the socket,
1759                  * we might find a transient negative value.
1760                  */
1761                 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1762
1763         seq_printf(seq,
1764                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1765                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1766                    i,
1767                    src->s6_addr32[0], src->s6_addr32[1],
1768                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1769                    dest->s6_addr32[0], dest->s6_addr32[1],
1770                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1771                    state,
1772                    tp->write_seq - tp->snd_una,
1773                    rx_queue,
1774                    timer_active,
1775                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1776                    icsk->icsk_retransmits,
1777                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1778                    icsk->icsk_probes_out,
1779                    sock_i_ino(sp),
1780                    atomic_read(&sp->sk_refcnt), sp,
1781                    jiffies_to_clock_t(icsk->icsk_rto),
1782                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1783                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1784                    tp->snd_cwnd,
1785                    state == TCP_LISTEN ?
1786                         fastopenq->max_qlen :
1787                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1788                    );
1789 }
1790
1791 static void get_timewait6_sock(struct seq_file *seq,
1792                                struct inet_timewait_sock *tw, int i)
1793 {
1794         long delta = tw->tw_timer.expires - jiffies;
1795         const struct in6_addr *dest, *src;
1796         __u16 destp, srcp;
1797
1798         dest = &tw->tw_v6_daddr;
1799         src  = &tw->tw_v6_rcv_saddr;
1800         destp = ntohs(tw->tw_dport);
1801         srcp  = ntohs(tw->tw_sport);
1802
1803         seq_printf(seq,
1804                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1805                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1806                    i,
1807                    src->s6_addr32[0], src->s6_addr32[1],
1808                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1809                    dest->s6_addr32[0], dest->s6_addr32[1],
1810                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1811                    tw->tw_substate, 0, 0,
1812                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1813                    atomic_read(&tw->tw_refcnt), tw);
1814 }
1815
1816 static int tcp6_seq_show(struct seq_file *seq, void *v)
1817 {
1818         struct tcp_iter_state *st;
1819         struct sock *sk = v;
1820
1821         if (v == SEQ_START_TOKEN) {
1822                 seq_puts(seq,
1823                          "  sl  "
1824                          "local_address                         "
1825                          "remote_address                        "
1826                          "st tx_queue rx_queue tr tm->when retrnsmt"
1827                          "   uid  timeout inode\n");
1828                 goto out;
1829         }
1830         st = seq->private;
1831
1832         if (sk->sk_state == TCP_TIME_WAIT)
1833                 get_timewait6_sock(seq, v, st->num);
1834         else if (sk->sk_state == TCP_NEW_SYN_RECV)
1835                 get_openreq6(seq, v, st->num);
1836         else
1837                 get_tcp6_sock(seq, v, st->num);
1838 out:
1839         return 0;
1840 }
1841
1842 static const struct file_operations tcp6_afinfo_seq_fops = {
1843         .owner   = THIS_MODULE,
1844         .open    = tcp_seq_open,
1845         .read    = seq_read,
1846         .llseek  = seq_lseek,
1847         .release = seq_release_net
1848 };
1849
1850 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1851         .name           = "tcp6",
1852         .family         = AF_INET6,
1853         .seq_fops       = &tcp6_afinfo_seq_fops,
1854         .seq_ops        = {
1855                 .show           = tcp6_seq_show,
1856         },
1857 };
1858
1859 int __net_init tcp6_proc_init(struct net *net)
1860 {
1861         return tcp_proc_register(net, &tcp6_seq_afinfo);
1862 }
1863
1864 void tcp6_proc_exit(struct net *net)
1865 {
1866         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1867 }
1868 #endif
1869
1870 struct proto tcpv6_prot = {
1871         .name                   = "TCPv6",
1872         .owner                  = THIS_MODULE,
1873         .close                  = tcp_close,
1874         .connect                = tcp_v6_connect,
1875         .disconnect             = tcp_disconnect,
1876         .accept                 = inet_csk_accept,
1877         .ioctl                  = tcp_ioctl,
1878         .init                   = tcp_v6_init_sock,
1879         .destroy                = tcp_v6_destroy_sock,
1880         .shutdown               = tcp_shutdown,
1881         .setsockopt             = tcp_setsockopt,
1882         .getsockopt             = tcp_getsockopt,
1883         .recvmsg                = tcp_recvmsg,
1884         .sendmsg                = tcp_sendmsg,
1885         .sendpage               = tcp_sendpage,
1886         .backlog_rcv            = tcp_v6_do_rcv,
1887         .release_cb             = tcp_release_cb,
1888         .hash                   = inet6_hash,
1889         .unhash                 = inet_unhash,
1890         .get_port               = inet_csk_get_port,
1891         .enter_memory_pressure  = tcp_enter_memory_pressure,
1892         .stream_memory_free     = tcp_stream_memory_free,
1893         .sockets_allocated      = &tcp_sockets_allocated,
1894         .memory_allocated       = &tcp_memory_allocated,
1895         .memory_pressure        = &tcp_memory_pressure,
1896         .orphan_count           = &tcp_orphan_count,
1897         .sysctl_mem             = sysctl_tcp_mem,
1898         .sysctl_wmem            = sysctl_tcp_wmem,
1899         .sysctl_rmem            = sysctl_tcp_rmem,
1900         .max_header             = MAX_TCP_HEADER,
1901         .obj_size               = sizeof(struct tcp6_sock),
1902         .slab_flags             = SLAB_DESTROY_BY_RCU,
1903         .twsk_prot              = &tcp6_timewait_sock_ops,
1904         .rsk_prot               = &tcp6_request_sock_ops,
1905         .h.hashinfo             = &tcp_hashinfo,
1906         .no_autobind            = true,
1907 #ifdef CONFIG_COMPAT
1908         .compat_setsockopt      = compat_tcp_setsockopt,
1909         .compat_getsockopt      = compat_tcp_getsockopt,
1910 #endif
1911         .diag_destroy           = tcp_abort,
1912 };
1913
1914 static const struct inet6_protocol tcpv6_protocol = {
1915         .early_demux    =       tcp_v6_early_demux,
1916         .handler        =       tcp_v6_rcv,
1917         .err_handler    =       tcp_v6_err,
1918         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1919 };
1920
1921 static struct inet_protosw tcpv6_protosw = {
1922         .type           =       SOCK_STREAM,
1923         .protocol       =       IPPROTO_TCP,
1924         .prot           =       &tcpv6_prot,
1925         .ops            =       &inet6_stream_ops,
1926         .flags          =       INET_PROTOSW_PERMANENT |
1927                                 INET_PROTOSW_ICSK,
1928 };
1929
1930 static int __net_init tcpv6_net_init(struct net *net)
1931 {
1932         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1933                                     SOCK_RAW, IPPROTO_TCP, net);
1934 }
1935
1936 static void __net_exit tcpv6_net_exit(struct net *net)
1937 {
1938         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1939 }
1940
1941 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1942 {
1943         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1944 }
1945
1946 static struct pernet_operations tcpv6_net_ops = {
1947         .init       = tcpv6_net_init,
1948         .exit       = tcpv6_net_exit,
1949         .exit_batch = tcpv6_net_exit_batch,
1950 };
1951
1952 int __init tcpv6_init(void)
1953 {
1954         int ret;
1955
1956         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1957         if (ret)
1958                 goto out;
1959
1960         /* register inet6 protocol */
1961         ret = inet6_register_protosw(&tcpv6_protosw);
1962         if (ret)
1963                 goto out_tcpv6_protocol;
1964
1965         ret = register_pernet_subsys(&tcpv6_net_ops);
1966         if (ret)
1967                 goto out_tcpv6_protosw;
1968 out:
1969         return ret;
1970
1971 out_tcpv6_protosw:
1972         inet6_unregister_protosw(&tcpv6_protosw);
1973 out_tcpv6_protocol:
1974         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1975         goto out;
1976 }
1977
1978 void tcpv6_exit(void)
1979 {
1980         unregister_pernet_subsys(&tcpv6_net_ops);
1981         inet6_unregister_protosw(&tcpv6_protosw);
1982         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1983 }