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(const struct sock *sk, struct sk_buff *skb);
  74 static void     tcp_v6_reqsk_send_ack(const 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(const 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                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 103         }
 104 }
 105
 106 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 107 {
 108         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 109                                             ipv6_hdr(skb)->saddr.s6_addr32,
 110                                             tcp_hdr(skb)->dest,
 111                                             tcp_hdr(skb)->source);
 112 }
 113
 114 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 115                           int addr_len)
 116 {
 117         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 118         struct inet_sock *inet = inet_sk(sk);
 119         struct inet_connection_sock *icsk = inet_csk(sk);
 120         struct ipv6_pinfo *np = inet6_sk(sk);
 121         struct tcp_sock *tp = tcp_sk(sk);
 122         struct in6_addr *saddr = NULL, *final_p, final;
 123         struct flowi6 fl6;
 124         struct dst_entry *dst;
 125         int addr_type;
 126         int err;
 127
 128         if (addr_len < SIN6_LEN_RFC2133)
 129                 return -EINVAL;
 130
 131         if (usin->sin6_family != AF_INET6)
 132                 return -EAFNOSUPPORT;
 133
 134         memset(&fl6, 0, sizeof(fl6));
 135
 136         if (np->sndflow) {
 137                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 138                 IP6_ECN_flow_init(fl6.flowlabel);
 139                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 140                         struct ip6_flowlabel *flowlabel;
 141                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 142                         if (!flowlabel)
 143                                 return -EINVAL;
 144                         fl6_sock_release(flowlabel);
 145                 }
 146         }
 147
 148         /*
 149          *      connect() to INADDR_ANY means loopback (BSD'ism).
 150          */
 151
 152         if (ipv6_addr_any(&usin->sin6_addr))
 153                 usin->sin6_addr.s6_addr[15] = 0x1;
 154
 155         addr_type = ipv6_addr_type(&usin->sin6_addr);
 156
 157         if (addr_type & IPV6_ADDR_MULTICAST)
 158                 return -ENETUNREACH;
 159
 160         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 161                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 162                     usin->sin6_scope_id) {
 163                         /* If interface is set while binding, indices
 164                          * must coincide.
 165                          */
 166                         if (sk->sk_bound_dev_if &&
 167                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 168                                 return -EINVAL;
 169
 170                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 171                 }
 172
 173                 /* Connect to link-local address requires an interface */
 174                 if (!sk->sk_bound_dev_if)
 175                         return -EINVAL;
 176         }
 177
 178         if (tp->rx_opt.ts_recent_stamp &&
 179             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 180                 tp->rx_opt.ts_recent = 0;
 181                 tp->rx_opt.ts_recent_stamp = 0;
 182                 tp->write_seq = 0;
 183         }
 184
 185         sk->sk_v6_daddr = usin->sin6_addr;
 186         np->flow_label = fl6.flowlabel;
 187
 188         /*
 189          *      TCP over IPv4
 190          */
 191
 192         if (addr_type == IPV6_ADDR_MAPPED) {
 193                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 194                 struct sockaddr_in sin;
 195
 196                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 197
 198                 if (__ipv6_only_sock(sk))
 199                         return -ENETUNREACH;
 200
 201                 sin.sin_family = AF_INET;
 202                 sin.sin_port = usin->sin6_port;
 203                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 204
 205                 icsk->icsk_af_ops = &ipv6_mapped;
 206                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 207 #ifdef CONFIG_TCP_MD5SIG
 208                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 209 #endif
 210
 211                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 212
 213                 if (err) {
 214                         icsk->icsk_ext_hdr_len = exthdrlen;
 215                         icsk->icsk_af_ops = &ipv6_specific;
 216                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 217 #ifdef CONFIG_TCP_MD5SIG
 218                         tp->af_specific = &tcp_sock_ipv6_specific;
 219 #endif
 220                         goto failure;
 221                 }
 222                 np->saddr = sk->sk_v6_rcv_saddr;
 223
 224                 return err;
 225         }
 226
 227         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 228                 saddr = &sk->sk_v6_rcv_saddr;
 229
 230         fl6.flowi6_proto = IPPROTO_TCP;
 231         fl6.daddr = sk->sk_v6_daddr;
 232         fl6.saddr = saddr ? *saddr : np->saddr;
 233         fl6.flowi6_oif = sk->sk_bound_dev_if;
 234         fl6.flowi6_mark = sk->sk_mark;
 235         fl6.fl6_dport = usin->sin6_port;
 236         fl6.fl6_sport = inet->inet_sport;
 237
 238         final_p = fl6_update_dst(&fl6, np->opt, &final);
 239
 240         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 241
 242         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 243         if (IS_ERR(dst)) {
 244                 err = PTR_ERR(dst);
 245                 goto failure;
 246         }
 247
 248         if (!saddr) {
 249                 saddr = &fl6.saddr;
 250                 sk->sk_v6_rcv_saddr = *saddr;
 251         }
 252
 253         /* set the source address */
 254         np->saddr = *saddr;
 255         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 256
 257         sk->sk_gso_type = SKB_GSO_TCPV6;
 258         __ip6_dst_store(sk, dst, NULL, NULL);
 259
 260         if (tcp_death_row.sysctl_tw_recycle &&
 261             !tp->rx_opt.ts_recent_stamp &&
 262             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 263                 tcp_fetch_timewait_stamp(sk, dst);
 264
 265         icsk->icsk_ext_hdr_len = 0;
 266         if (np->opt)
 267                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 268                                           np->opt->opt_nflen);
 269
 270         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 271
 272         inet->inet_dport = usin->sin6_port;
 273
 274         tcp_set_state(sk, TCP_SYN_SENT);
 275         err = inet6_hash_connect(&tcp_death_row, sk);
 276         if (err)
 277                 goto late_failure;
 278
 279         sk_set_txhash(sk);
 280
 281         if (!tp->write_seq && likely(!tp->repair))
 282                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 283                                                              sk->sk_v6_daddr.s6_addr32,
 284                                                              inet->inet_sport,
 285                                                              inet->inet_dport);
 286
 287         err = tcp_connect(sk);
 288         if (err)
 289                 goto late_failure;
 290
 291         return 0;
 292
 293 late_failure:
 294         tcp_set_state(sk, TCP_CLOSE);
 295         __sk_dst_reset(sk);
 296 failure:
 297         inet->inet_dport = 0;
 298         sk->sk_route_caps = 0;
 299         return err;
 300 }
 301
 302 static void tcp_v6_mtu_reduced(struct sock *sk)
 303 {
 304         struct dst_entry *dst;
 305
 306         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 307                 return;
 308
 309         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 310         if (!dst)
 311                 return;
 312
 313         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 314                 tcp_sync_mss(sk, dst_mtu(dst));
 315                 tcp_simple_retransmit(sk);
 316         }
 317 }
 318
 319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 320                 u8 type, u8 code, int offset, __be32 info)
 321 {
 322         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 324         struct net *net = dev_net(skb->dev);
 325         struct request_sock *fastopen;
 326         struct ipv6_pinfo *np;
 327         struct tcp_sock *tp;
 328         __u32 seq, snd_una;
 329         struct sock *sk;
 330         int err;
 331
 332         sk = __inet6_lookup_established(net, &tcp_hashinfo,
 333                                         &hdr->daddr, th->dest,
 334                                         &hdr->saddr, ntohs(th->source),
 335                                         skb->dev->ifindex);
 336
 337         if (!sk) {
 338                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 339                                    ICMP6_MIB_INERRORS);
 340                 return;
 341         }
 342
 343         if (sk->sk_state == TCP_TIME_WAIT) {
 344                 inet_twsk_put(inet_twsk(sk));
 345                 return;
 346         }
 347         seq = ntohl(th->seq);
 348         if (sk->sk_state == TCP_NEW_SYN_RECV)
 349                 return tcp_req_err(sk, seq);
 350
 351         bh_lock_sock(sk);
 352         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 353                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 354
 355         if (sk->sk_state == TCP_CLOSE)
 356                 goto out;
 357
 358         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 359                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 360                 goto out;
 361         }
 362
 363         tp = tcp_sk(sk);
 364         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 365         fastopen = tp->fastopen_rsk;
 366         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 367         if (sk->sk_state != TCP_LISTEN &&
 368             !between(seq, snd_una, tp->snd_nxt)) {
 369                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 370                 goto out;
 371         }
 372
 373         np = inet6_sk(sk);
 374
 375         if (type == NDISC_REDIRECT) {
 376                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 377
 378                 if (dst)
 379                         dst->ops->redirect(dst, sk, skb);
 380                 goto out;
 381         }
 382
 383         if (type == ICMPV6_PKT_TOOBIG) {
 384                 /* We are not interested in TCP_LISTEN and open_requests
 385                  * (SYN-ACKs send out by Linux are always <576bytes so
 386                  * they should go through unfragmented).
 387                  */
 388                 if (sk->sk_state == TCP_LISTEN)
 389                         goto out;
 390
 391                 if (!ip6_sk_accept_pmtu(sk))
 392                         goto out;
 393
 394                 tp->mtu_info = ntohl(info);
 395                 if (!sock_owned_by_user(sk))
 396                         tcp_v6_mtu_reduced(sk);
 397                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 398                                            &tp->tsq_flags))
 399                         sock_hold(sk);
 400                 goto out;
 401         }
 402
 403         icmpv6_err_convert(type, code, &err);
 404
 405         /* Might be for an request_sock */
 406         switch (sk->sk_state) {
 407         case TCP_SYN_SENT:
 408         case TCP_SYN_RECV:
 409                 /* Only in fast or simultaneous open. If a fast open socket is
 410                  * is already accepted it is treated as a connected one below.
 411                  */
 412                 if (fastopen && !fastopen->sk)
 413                         break;
 414
 415                 if (!sock_owned_by_user(sk)) {
 416                         sk->sk_err = err;
 417                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 418
 419                         tcp_done(sk);
 420                 } else
 421                         sk->sk_err_soft = err;
 422                 goto out;
 423         }
 424
 425         if (!sock_owned_by_user(sk) && np->recverr) {
 426                 sk->sk_err = err;
 427                 sk->sk_error_report(sk);
 428         } else
 429                 sk->sk_err_soft = err;
 430
 431 out:
 432         bh_unlock_sock(sk);
 433         sock_put(sk);
 434 }
 435
 436
 437 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 438                               struct flowi *fl,
 439                               struct request_sock *req,
 440                               u16 queue_mapping,
 441                               struct tcp_fastopen_cookie *foc)
 442 {
 443         struct inet_request_sock *ireq = inet_rsk(req);
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct flowi6 *fl6 = &fl->u.ip6;
 446         struct sk_buff *skb;
 447         int err = -ENOMEM;
 448
 449         /* First, grab a route. */
 450         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
 451                                                IPPROTO_TCP)) == NULL)
 452                 goto done;
 453
 454         skb = tcp_make_synack(sk, dst, req, foc);
 455
 456         if (skb) {
 457                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 458                                     &ireq->ir_v6_rmt_addr);
 459
 460                 fl6->daddr = ireq->ir_v6_rmt_addr;
 461                 if (np->repflow && ireq->pktopts)
 462                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 463
 464                 skb_set_queue_mapping(skb, queue_mapping);
 465                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 466                 err = net_xmit_eval(err);
 467         }
 468
 469 done:
 470         return err;
 471 }
 472
 473
 474 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 475 {
 476         kfree_skb(inet_rsk(req)->pktopts);
 477 }
 478
 479 #ifdef CONFIG_TCP_MD5SIG
 480 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 481                                                    const struct in6_addr *addr)
 482 {
 483         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 484 }
 485
 486 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 487                                                 const struct sock *addr_sk)
 488 {
 489         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 490 }
 491
 492 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 493                                  int optlen)
 494 {
 495         struct tcp_md5sig cmd;
 496         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 497
 498         if (optlen < sizeof(cmd))
 499                 return -EINVAL;
 500
 501         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 502                 return -EFAULT;
 503
 504         if (sin6->sin6_family != AF_INET6)
 505                 return -EINVAL;
 506
 507         if (!cmd.tcpm_keylen) {
 508                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 509                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 510                                               AF_INET);
 511                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 512                                       AF_INET6);
 513         }
 514
 515         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 516                 return -EINVAL;
 517
 518         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 519                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 520                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 521
 522         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 523                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 524 }
 525
 526 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 527                                         const struct in6_addr *daddr,
 528                                         const struct in6_addr *saddr, int nbytes)
 529 {
 530         struct tcp6_pseudohdr *bp;
 531         struct scatterlist sg;
 532
 533         bp = &hp->md5_blk.ip6;
 534         /* 1. TCP pseudo-header (RFC2460) */
 535         bp->saddr = *saddr;
 536         bp->daddr = *daddr;
 537         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 538         bp->len = cpu_to_be32(nbytes);
 539
 540         sg_init_one(&sg, bp, sizeof(*bp));
 541         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 542 }
 543
 544 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 545                                const struct in6_addr *daddr, struct in6_addr *saddr,
 546                                const struct tcphdr *th)
 547 {
 548         struct tcp_md5sig_pool *hp;
 549         struct hash_desc *desc;
 550
 551         hp = tcp_get_md5sig_pool();
 552         if (!hp)
 553                 goto clear_hash_noput;
 554         desc = &hp->md5_desc;
 555
 556         if (crypto_hash_init(desc))
 557                 goto clear_hash;
 558         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 559                 goto clear_hash;
 560         if (tcp_md5_hash_header(hp, th))
 561                 goto clear_hash;
 562         if (tcp_md5_hash_key(hp, key))
 563                 goto clear_hash;
 564         if (crypto_hash_final(desc, md5_hash))
 565                 goto clear_hash;
 566
 567         tcp_put_md5sig_pool();
 568         return 0;
 569
 570 clear_hash:
 571         tcp_put_md5sig_pool();
 572 clear_hash_noput:
 573         memset(md5_hash, 0, 16);
 574         return 1;
 575 }
 576
 577 static int tcp_v6_md5_hash_skb(char *md5_hash,
 578                                const struct tcp_md5sig_key *key,
 579                                const struct sock *sk,
 580                                const struct sk_buff *skb)
 581 {
 582         const struct in6_addr *saddr, *daddr;
 583         struct tcp_md5sig_pool *hp;
 584         struct hash_desc *desc;
 585         const struct tcphdr *th = tcp_hdr(skb);
 586
 587         if (sk) { /* valid for establish/request sockets */
 588                 saddr = &sk->sk_v6_rcv_saddr;
 589                 daddr = &sk->sk_v6_daddr;
 590         } else {
 591                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 592                 saddr = &ip6h->saddr;
 593                 daddr = &ip6h->daddr;
 594         }
 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
 604         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 605                 goto clear_hash;
 606         if (tcp_md5_hash_header(hp, th))
 607                 goto clear_hash;
 608         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 609                 goto clear_hash;
 610         if (tcp_md5_hash_key(hp, key))
 611                 goto clear_hash;
 612         if (crypto_hash_final(desc, md5_hash))
 613                 goto clear_hash;
 614
 615         tcp_put_md5sig_pool();
 616         return 0;
 617
 618 clear_hash:
 619         tcp_put_md5sig_pool();
 620 clear_hash_noput:
 621         memset(md5_hash, 0, 16);
 622         return 1;
 623 }
 624
 625 #endif
 626
 627 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 628                                     const struct sk_buff *skb)
 629 {
 630 #ifdef CONFIG_TCP_MD5SIG
 631         const __u8 *hash_location = NULL;
 632         struct tcp_md5sig_key *hash_expected;
 633         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 634         const struct tcphdr *th = tcp_hdr(skb);
 635         int genhash;
 636         u8 newhash[16];
 637
 638         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 639         hash_location = tcp_parse_md5sig_option(th);
 640
 641         /* We've parsed the options - do we have a hash? */
 642         if (!hash_expected && !hash_location)
 643                 return false;
 644
 645         if (hash_expected && !hash_location) {
 646                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 647                 return true;
 648         }
 649
 650         if (!hash_expected && hash_location) {
 651                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 652                 return true;
 653         }
 654
 655         /* check the signature */
 656         genhash = tcp_v6_md5_hash_skb(newhash,
 657                                       hash_expected,
 658                                       NULL, skb);
 659
 660         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 661                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 662                                      genhash ? "failed" : "mismatch",
 663                                      &ip6h->saddr, ntohs(th->source),
 664                                      &ip6h->daddr, ntohs(th->dest));
 665                 return true;
 666         }
 667 #endif
 668         return false;
 669 }
 670
 671 static void tcp_v6_init_req(struct request_sock *req,
 672                             const struct sock *sk_listener,
 673                             struct sk_buff *skb)
 674 {
 675         struct inet_request_sock *ireq = inet_rsk(req);
 676         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 677
 678         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 679         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 680
 681         /* So that link locals have meaning */
 682         if (!sk_listener->sk_bound_dev_if &&
 683             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 684                 ireq->ir_iif = tcp_v6_iif(skb);
 685
 686         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 687             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 688              np->rxopt.bits.rxinfo ||
 689              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 690              np->rxopt.bits.rxohlim || np->repflow)) {
 691                 atomic_inc(&skb->users);
 692                 ireq->pktopts = skb;
 693         }
 694 }
 695
 696 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 697                                           struct flowi *fl,
 698                                           const struct request_sock *req,
 699                                           bool *strict)
 700 {
 701         if (strict)
 702                 *strict = true;
 703         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 704 }
 705
 706 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 707         .family         =       AF_INET6,
 708         .obj_size       =       sizeof(struct tcp6_request_sock),
 709         .rtx_syn_ack    =       tcp_rtx_synack,
 710         .send_ack       =       tcp_v6_reqsk_send_ack,
 711         .destructor     =       tcp_v6_reqsk_destructor,
 712         .send_reset     =       tcp_v6_send_reset,
 713         .syn_ack_timeout =      tcp_syn_ack_timeout,
 714 };
 715
 716 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 717         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 718                                 sizeof(struct ipv6hdr),
 719 #ifdef CONFIG_TCP_MD5SIG
 720         .req_md5_lookup =       tcp_v6_md5_lookup,
 721         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 722 #endif
 723         .init_req       =       tcp_v6_init_req,
 724 #ifdef CONFIG_SYN_COOKIES
 725         .cookie_init_seq =      cookie_v6_init_sequence,
 726 #endif
 727         .route_req      =       tcp_v6_route_req,
 728         .init_seq       =       tcp_v6_init_sequence,
 729         .send_synack    =       tcp_v6_send_synack,
 730         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 731 };
 732
 733 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 734                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 735                                  int oif, struct tcp_md5sig_key *key, int rst,
 736                                  u8 tclass, u32 label)
 737 {
 738         const struct tcphdr *th = tcp_hdr(skb);
 739         struct tcphdr *t1;
 740         struct sk_buff *buff;
 741         struct flowi6 fl6;
 742         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 743         struct sock *ctl_sk = net->ipv6.tcp_sk;
 744         unsigned int tot_len = sizeof(struct tcphdr);
 745         struct dst_entry *dst;
 746         __be32 *topt;
 747
 748         if (tsecr)
 749                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 750 #ifdef CONFIG_TCP_MD5SIG
 751         if (key)
 752                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 753 #endif
 754
 755         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 756                          GFP_ATOMIC);
 757         if (!buff)
 758                 return;
 759
 760         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 761
 762         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 763         skb_reset_transport_header(buff);
 764
 765         /* Swap the send and the receive. */
 766         memset(t1, 0, sizeof(*t1));
 767         t1->dest = th->source;
 768         t1->source = th->dest;
 769         t1->doff = tot_len / 4;
 770         t1->seq = htonl(seq);
 771         t1->ack_seq = htonl(ack);
 772         t1->ack = !rst || !th->ack;
 773         t1->rst = rst;
 774         t1->window = htons(win);
 775
 776         topt = (__be32 *)(t1 + 1);
 777
 778         if (tsecr) {
 779                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 780                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 781                 *topt++ = htonl(tsval);
 782                 *topt++ = htonl(tsecr);
 783         }
 784
 785 #ifdef CONFIG_TCP_MD5SIG
 786         if (key) {
 787                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 788                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 789                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 790                                     &ipv6_hdr(skb)->saddr,
 791                                     &ipv6_hdr(skb)->daddr, t1);
 792         }
 793 #endif
 794
 795         memset(&fl6, 0, sizeof(fl6));
 796         fl6.daddr = ipv6_hdr(skb)->saddr;
 797         fl6.saddr = ipv6_hdr(skb)->daddr;
 798         fl6.flowlabel = label;
 799
 800         buff->ip_summed = CHECKSUM_PARTIAL;
 801         buff->csum = 0;
 802
 803         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 804
 805         fl6.flowi6_proto = IPPROTO_TCP;
 806         if (rt6_need_strict(&fl6.daddr) && !oif)
 807                 fl6.flowi6_oif = tcp_v6_iif(skb);
 808         else
 809                 fl6.flowi6_oif = oif;
 810         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 811         fl6.fl6_dport = t1->dest;
 812         fl6.fl6_sport = t1->source;
 813         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 814
 815         /* Pass a socket to ip6_dst_lookup either it is for RST
 816          * Underlying function will use this to retrieve the network
 817          * namespace
 818          */
 819         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 820         if (!IS_ERR(dst)) {
 821                 skb_dst_set(buff, dst);
 822                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 823                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 824                 if (rst)
 825                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 826                 return;
 827         }
 828
 829         kfree_skb(buff);
 830 }
 831
 832 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 833 {
 834         const struct tcphdr *th = tcp_hdr(skb);
 835         u32 seq = 0, ack_seq = 0;
 836         struct tcp_md5sig_key *key = NULL;
 837 #ifdef CONFIG_TCP_MD5SIG
 838         const __u8 *hash_location = NULL;
 839         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 840         unsigned char newhash[16];
 841         int genhash;
 842         struct sock *sk1 = NULL;
 843 #endif
 844         int oif;
 845
 846         if (th->rst)
 847                 return;
 848
 849         /* If sk not NULL, it means we did a successful lookup and incoming
 850          * route had to be correct. prequeue might have dropped our dst.
 851          */
 852         if (!sk && !ipv6_unicast_destination(skb))
 853                 return;
 854
 855 #ifdef CONFIG_TCP_MD5SIG
 856         hash_location = tcp_parse_md5sig_option(th);
 857         if (!sk && hash_location) {
 858                 /*
 859                  * active side is lost. Try to find listening socket through
 860                  * source port, and then find md5 key through listening socket.
 861                  * we are not loose security here:
 862                  * Incoming packet is checked with md5 hash with finding key,
 863                  * no RST generated if md5 hash doesn't match.
 864                  */
 865                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 866                                            &tcp_hashinfo, &ipv6h->saddr,
 867                                            th->source, &ipv6h->daddr,
 868                                            ntohs(th->source), tcp_v6_iif(skb));
 869                 if (!sk1)
 870                         return;
 871
 872                 rcu_read_lock();
 873                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 874                 if (!key)
 875                         goto release_sk1;
 876
 877                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 878                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 879                         goto release_sk1;
 880         } else {
 881                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 882         }
 883 #endif
 884
 885         if (th->ack)
 886                 seq = ntohl(th->ack_seq);
 887         else
 888                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 889                           (th->doff << 2);
 890
 891         oif = sk ? sk->sk_bound_dev_if : 0;
 892         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 893
 894 #ifdef CONFIG_TCP_MD5SIG
 895 release_sk1:
 896         if (sk1) {
 897                 rcu_read_unlock();
 898                 sock_put(sk1);
 899         }
 900 #endif
 901 }
 902
 903 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 904                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 905                             struct tcp_md5sig_key *key, u8 tclass,
 906                             u32 label)
 907 {
 908         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 909                              tclass, label);
 910 }
 911
 912 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 913 {
 914         struct inet_timewait_sock *tw = inet_twsk(sk);
 915         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 916
 917         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 918                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 919                         tcp_time_stamp + tcptw->tw_ts_offset,
 920                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 921                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 922
 923         inet_twsk_put(tw);
 924 }
 925
 926 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 927                                   struct request_sock *req)
 928 {
 929         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 930          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 931          */
 932         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 933                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 934                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 935                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 936                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 937                         0, 0);
 938 }
 939
 940
 941 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 942 {
 943         const struct tcphdr *th = tcp_hdr(skb);
 944         struct request_sock *req;
 945         struct sock *nsk;
 946
 947         /* Find possible connection requests. */
 948         req = inet6_csk_search_req(sk, th->source,
 949                                    &ipv6_hdr(skb)->saddr,
 950                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 951         if (req) {
 952                 nsk = tcp_check_req(sk, skb, req, false);
 953                 if (!nsk || nsk == sk)
 954                         reqsk_put(req);
 955                 return nsk;
 956         }
 957         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 958                                          &ipv6_hdr(skb)->saddr, th->source,
 959                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 960                                          tcp_v6_iif(skb));
 961
 962         if (nsk) {
 963                 if (nsk->sk_state != TCP_TIME_WAIT) {
 964                         bh_lock_sock(nsk);
 965                         return nsk;
 966                 }
 967                 inet_twsk_put(inet_twsk(nsk));
 968                 return NULL;
 969         }
 970
 971 #ifdef CONFIG_SYN_COOKIES
 972         if (!th->syn)
 973                 sk = cookie_v6_check(sk, skb);
 974 #endif
 975         return sk;
 976 }
 977
 978 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 979 {
 980         if (skb->protocol == htons(ETH_P_IP))
 981                 return tcp_v4_conn_request(sk, skb);
 982
 983         if (!ipv6_unicast_destination(skb))
 984                 goto drop;
 985
 986         return tcp_conn_request(&tcp6_request_sock_ops,
 987                                 &tcp_request_sock_ipv6_ops, sk, skb);
 988
 989 drop:
 990         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 991         return 0; /* don't send reset */
 992 }
 993
 994 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 995                                          struct request_sock *req,
 996                                          struct dst_entry *dst)
 997 {
 998         struct inet_request_sock *ireq;
 999         struct ipv6_pinfo *newnp;
1000         const struct ipv6_pinfo *np = inet6_sk(sk);
1001         struct tcp6_sock *newtcp6sk;
1002         struct inet_sock *newinet;
1003         struct tcp_sock *newtp;
1004         struct sock *newsk;
1005 #ifdef CONFIG_TCP_MD5SIG
1006         struct tcp_md5sig_key *key;
1007 #endif
1008         struct flowi6 fl6;
1009
1010         if (skb->protocol == htons(ETH_P_IP)) {
1011                 /*
1012                  *      v6 mapped
1013                  */
1014
1015                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1016
1017                 if (!newsk)
1018                         return NULL;
1019
1020                 newtcp6sk = (struct tcp6_sock *)newsk;
1021                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1022
1023                 newinet = inet_sk(newsk);
1024                 newnp = inet6_sk(newsk);
1025                 newtp = tcp_sk(newsk);
1026
1027                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1028
1029                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1030
1031                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1032                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1033 #ifdef CONFIG_TCP_MD5SIG
1034                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1035 #endif
1036
1037                 newnp->ipv6_ac_list = NULL;
1038                 newnp->ipv6_fl_list = NULL;
1039                 newnp->pktoptions  = NULL;
1040                 newnp->opt         = NULL;
1041                 newnp->mcast_oif   = tcp_v6_iif(skb);
1042                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1043                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1044                 if (np->repflow)
1045                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1046
1047                 /*
1048                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1049                  * here, tcp_create_openreq_child now does this for us, see the comment in
1050                  * that function for the gory details. -acme
1051                  */
1052
1053                 /* It is tricky place. Until this moment IPv4 tcp
1054                    worked with IPv6 icsk.icsk_af_ops.
1055                    Sync it now.
1056                  */
1057                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1058
1059                 return newsk;
1060         }
1061
1062         ireq = inet_rsk(req);
1063
1064         if (sk_acceptq_is_full(sk))
1065                 goto out_overflow;
1066
1067         if (!dst) {
1068                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1069                 if (!dst)
1070                         goto out;
1071         }
1072
1073         newsk = tcp_create_openreq_child(sk, req, skb);
1074         if (!newsk)
1075                 goto out_nonewsk;
1076
1077         /*
1078          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1079          * count here, tcp_create_openreq_child now does this for us, see the
1080          * comment in that function for the gory details. -acme
1081          */
1082
1083         newsk->sk_gso_type = SKB_GSO_TCPV6;
1084         __ip6_dst_store(newsk, dst, NULL, NULL);
1085         inet6_sk_rx_dst_set(newsk, skb);
1086
1087         newtcp6sk = (struct tcp6_sock *)newsk;
1088         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1089
1090         newtp = tcp_sk(newsk);
1091         newinet = inet_sk(newsk);
1092         newnp = inet6_sk(newsk);
1093
1094         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1095
1096         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1097         newnp->saddr = ireq->ir_v6_loc_addr;
1098         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1099         newsk->sk_bound_dev_if = ireq->ir_iif;
1100
1101         /* Now IPv6 options...
1102
1103            First: no IPv4 options.
1104          */
1105         newinet->inet_opt = NULL;
1106         newnp->ipv6_ac_list = NULL;
1107         newnp->ipv6_fl_list = NULL;
1108
1109         /* Clone RX bits */
1110         newnp->rxopt.all = np->rxopt.all;
1111
1112         /* Clone pktoptions received with SYN */
1113         newnp->pktoptions = NULL;
1114         if (ireq->pktopts) {
1115                 newnp->pktoptions = skb_clone(ireq->pktopts,
1116                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1117                 consume_skb(ireq->pktopts);
1118                 ireq->pktopts = NULL;
1119                 if (newnp->pktoptions)
1120                         skb_set_owner_r(newnp->pktoptions, newsk);
1121         }
1122         newnp->opt        = NULL;
1123         newnp->mcast_oif  = tcp_v6_iif(skb);
1124         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1125         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1126         if (np->repflow)
1127                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1128
1129         /* Clone native IPv6 options from listening socket (if any)
1130
1131            Yes, keeping reference count would be much more clever,
1132            but we make one more one thing there: reattach optmem
1133            to newsk.
1134          */
1135         if (np->opt)
1136                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1137
1138         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1139         if (newnp->opt)
1140                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1141                                                      newnp->opt->opt_flen);
1142
1143         tcp_ca_openreq_child(newsk, dst);
1144
1145         tcp_sync_mss(newsk, dst_mtu(dst));
1146         newtp->advmss = dst_metric_advmss(dst);
1147         if (tcp_sk(sk)->rx_opt.user_mss &&
1148             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1149                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1150
1151         tcp_initialize_rcv_mss(newsk);
1152
1153         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1154         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1155
1156 #ifdef CONFIG_TCP_MD5SIG
1157         /* Copy over the MD5 key from the original socket */
1158         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1159         if (key) {
1160                 /* We're using one, so create a matching key
1161                  * on the newsk structure. If we fail to get
1162                  * memory, then we end up not copying the key
1163                  * across. Shucks.
1164                  */
1165                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1166                                AF_INET6, key->key, key->keylen,
1167                                sk_gfp_atomic(sk, GFP_ATOMIC));
1168         }
1169 #endif
1170
1171         if (__inet_inherit_port(sk, newsk) < 0) {
1172                 inet_csk_prepare_forced_close(newsk);
1173                 tcp_done(newsk);
1174                 goto out;
1175         }
1176         __inet_hash(newsk, NULL);
1177
1178         return newsk;
1179
1180 out_overflow:
1181         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1182 out_nonewsk:
1183         dst_release(dst);
1184 out:
1185         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1186         return NULL;
1187 }
1188
1189 /* The socket must have it's spinlock held when we get
1190  * here.
1191  *
1192  * We have a potential double-lock case here, so even when
1193  * doing backlog processing we use the BH locking scheme.
1194  * This is because we cannot sleep with the original spinlock
1195  * held.
1196  */
1197 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1198 {
1199         struct ipv6_pinfo *np = inet6_sk(sk);
1200         struct tcp_sock *tp;
1201         struct sk_buff *opt_skb = NULL;
1202
1203         /* Imagine: socket is IPv6. IPv4 packet arrives,
1204            goes to IPv4 receive handler and backlogged.
1205            From backlog it always goes here. Kerboom...
1206            Fortunately, tcp_rcv_established and rcv_established
1207            handle them correctly, but it is not case with
1208            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1209          */
1210
1211         if (skb->protocol == htons(ETH_P_IP))
1212                 return tcp_v4_do_rcv(sk, skb);
1213
1214         if (sk_filter(sk, skb))
1215                 goto discard;
1216
1217         /*
1218          *      socket locking is here for SMP purposes as backlog rcv
1219          *      is currently called with bh processing disabled.
1220          */
1221
1222         /* Do Stevens' IPV6_PKTOPTIONS.
1223
1224            Yes, guys, it is the only place in our code, where we
1225            may make it not affecting IPv4.
1226            The rest of code is protocol independent,
1227            and I do not like idea to uglify IPv4.
1228
1229            Actually, all the idea behind IPV6_PKTOPTIONS
1230            looks not very well thought. For now we latch
1231            options, received in the last packet, enqueued
1232            by tcp. Feel free to propose better solution.
1233                                                --ANK (980728)
1234          */
1235         if (np->rxopt.all)
1236                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1237
1238         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1239                 struct dst_entry *dst = sk->sk_rx_dst;
1240
1241                 sock_rps_save_rxhash(sk, skb);
1242                 sk_mark_napi_id(sk, skb);
1243                 if (dst) {
1244                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1245                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1246                                 dst_release(dst);
1247                                 sk->sk_rx_dst = NULL;
1248                         }
1249                 }
1250
1251                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1252                 if (opt_skb)
1253                         goto ipv6_pktoptions;
1254                 return 0;
1255         }
1256
1257         if (tcp_checksum_complete(skb))
1258                 goto csum_err;
1259
1260         if (sk->sk_state == TCP_LISTEN) {
1261                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1262                 if (!nsk)
1263                         goto discard;
1264
1265                 /*
1266                  * Queue it on the new socket if the new socket is active,
1267                  * otherwise we just shortcircuit this and continue with
1268                  * the new socket..
1269                  */
1270                 if (nsk != sk) {
1271                         sock_rps_save_rxhash(nsk, skb);
1272                         sk_mark_napi_id(nsk, skb);
1273                         if (tcp_child_process(sk, nsk, skb))
1274                                 goto reset;
1275                         if (opt_skb)
1276                                 __kfree_skb(opt_skb);
1277                         return 0;
1278                 }
1279         } else
1280                 sock_rps_save_rxhash(sk, skb);
1281
1282         if (tcp_rcv_state_process(sk, skb))
1283                 goto reset;
1284         if (opt_skb)
1285                 goto ipv6_pktoptions;
1286         return 0;
1287
1288 reset:
1289         tcp_v6_send_reset(sk, skb);
1290 discard:
1291         if (opt_skb)
1292                 __kfree_skb(opt_skb);
1293         kfree_skb(skb);
1294         return 0;
1295 csum_err:
1296         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1297         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1298         goto discard;
1299
1300
1301 ipv6_pktoptions:
1302         /* Do you ask, what is it?
1303
1304            1. skb was enqueued by tcp.
1305            2. skb is added to tail of read queue, rather than out of order.
1306            3. socket is not in passive state.
1307            4. Finally, it really contains options, which user wants to receive.
1308          */
1309         tp = tcp_sk(sk);
1310         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1311             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1312                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1313                         np->mcast_oif = tcp_v6_iif(opt_skb);
1314                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1315                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1316                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1317                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1318                 if (np->repflow)
1319                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1320                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1321                         skb_set_owner_r(opt_skb, sk);
1322                         opt_skb = xchg(&np->pktoptions, opt_skb);
1323                 } else {
1324                         __kfree_skb(opt_skb);
1325                         opt_skb = xchg(&np->pktoptions, NULL);
1326                 }
1327         }
1328
1329         kfree_skb(opt_skb);
1330         return 0;
1331 }
1332
1333 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1334                            const struct tcphdr *th)
1335 {
1336         /* This is tricky: we move IP6CB at its correct location into
1337          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1338          * _decode_session6() uses IP6CB().
1339          * barrier() makes sure compiler won't play aliasing games.
1340          */
1341         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1342                 sizeof(struct inet6_skb_parm));
1343         barrier();
1344
1345         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1346         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1347                                     skb->len - th->doff*4);
1348         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1349         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1350         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1351         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1352         TCP_SKB_CB(skb)->sacked = 0;
1353 }
1354
1355 static void tcp_v6_restore_cb(struct sk_buff *skb)
1356 {
1357         /* We need to move header back to the beginning if xfrm6_policy_check()
1358          * and tcp_v6_fill_cb() are going to be called again.
1359          */
1360         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1361                 sizeof(struct inet6_skb_parm));
1362 }
1363
1364 static int tcp_v6_rcv(struct sk_buff *skb)
1365 {
1366         const struct tcphdr *th;
1367         const struct ipv6hdr *hdr;
1368         struct sock *sk;
1369         int ret;
1370         struct net *net = dev_net(skb->dev);
1371
1372         if (skb->pkt_type != PACKET_HOST)
1373                 goto discard_it;
1374
1375         /*
1376          *      Count it even if it's bad.
1377          */
1378         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1379
1380         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1381                 goto discard_it;
1382
1383         th = tcp_hdr(skb);
1384
1385         if (th->doff < sizeof(struct tcphdr)/4)
1386                 goto bad_packet;
1387         if (!pskb_may_pull(skb, th->doff*4))
1388                 goto discard_it;
1389
1390         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1391                 goto csum_error;
1392
1393         th = tcp_hdr(skb);
1394         hdr = ipv6_hdr(skb);
1395
1396         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1397                                 inet6_iif(skb));
1398         if (!sk)
1399                 goto no_tcp_socket;
1400
1401 process:
1402         if (sk->sk_state == TCP_TIME_WAIT)
1403                 goto do_time_wait;
1404
1405         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1406                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1407                 goto discard_and_relse;
1408         }
1409
1410         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1411                 goto discard_and_relse;
1412
1413         tcp_v6_fill_cb(skb, hdr, th);
1414
1415         if (tcp_v6_inbound_md5_hash(sk, skb))
1416                 goto discard_and_relse;
1417
1418         if (sk_filter(sk, skb))
1419                 goto discard_and_relse;
1420
1421         sk_incoming_cpu_update(sk);
1422         skb->dev = NULL;
1423
1424         bh_lock_sock_nested(sk);
1425         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1426         ret = 0;
1427         if (!sock_owned_by_user(sk)) {
1428                 if (!tcp_prequeue(sk, skb))
1429                         ret = tcp_v6_do_rcv(sk, skb);
1430         } else if (unlikely(sk_add_backlog(sk, skb,
1431                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1432                 bh_unlock_sock(sk);
1433                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1434                 goto discard_and_relse;
1435         }
1436         bh_unlock_sock(sk);
1437
1438         sock_put(sk);
1439         return ret ? -1 : 0;
1440
1441 no_tcp_socket:
1442         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1443                 goto discard_it;
1444
1445         tcp_v6_fill_cb(skb, hdr, th);
1446
1447         if (tcp_checksum_complete(skb)) {
1448 csum_error:
1449                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1450 bad_packet:
1451                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1452         } else {
1453                 tcp_v6_send_reset(NULL, skb);
1454         }
1455
1456 discard_it:
1457         kfree_skb(skb);
1458         return 0;
1459
1460 discard_and_relse:
1461         sock_put(sk);
1462         goto discard_it;
1463
1464 do_time_wait:
1465         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1466                 inet_twsk_put(inet_twsk(sk));
1467                 goto discard_it;
1468         }
1469
1470         tcp_v6_fill_cb(skb, hdr, th);
1471
1472         if (tcp_checksum_complete(skb)) {
1473                 inet_twsk_put(inet_twsk(sk));
1474                 goto csum_error;
1475         }
1476
1477         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1478         case TCP_TW_SYN:
1479         {
1480                 struct sock *sk2;
1481
1482                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1483                                             &ipv6_hdr(skb)->saddr, th->source,
1484                                             &ipv6_hdr(skb)->daddr,
1485                                             ntohs(th->dest), tcp_v6_iif(skb));
1486                 if (sk2) {
1487                         struct inet_timewait_sock *tw = inet_twsk(sk);
1488                         inet_twsk_deschedule_put(tw);
1489                         sk = sk2;
1490                         tcp_v6_restore_cb(skb);
1491                         goto process;
1492                 }
1493                 /* Fall through to ACK */
1494         }
1495         case TCP_TW_ACK:
1496                 tcp_v6_timewait_ack(sk, skb);
1497                 break;
1498         case TCP_TW_RST:
1499                 tcp_v6_restore_cb(skb);
1500                 goto no_tcp_socket;
1501         case TCP_TW_SUCCESS:
1502                 ;
1503         }
1504         goto discard_it;
1505 }
1506
1507 static void tcp_v6_early_demux(struct sk_buff *skb)
1508 {
1509         const struct ipv6hdr *hdr;
1510         const struct tcphdr *th;
1511         struct sock *sk;
1512
1513         if (skb->pkt_type != PACKET_HOST)
1514                 return;
1515
1516         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1517                 return;
1518
1519         hdr = ipv6_hdr(skb);
1520         th = tcp_hdr(skb);
1521
1522         if (th->doff < sizeof(struct tcphdr) / 4)
1523                 return;
1524
1525         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1526         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1527                                         &hdr->saddr, th->source,
1528                                         &hdr->daddr, ntohs(th->dest),
1529                                         inet6_iif(skb));
1530         if (sk) {
1531                 skb->sk = sk;
1532                 skb->destructor = sock_edemux;
1533                 if (sk_fullsock(sk)) {
1534                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1535
1536                         if (dst)
1537                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1538                         if (dst &&
1539                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1540                                 skb_dst_set_noref(skb, dst);
1541                 }
1542         }
1543 }
1544
1545 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1546         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1547         .twsk_unique    = tcp_twsk_unique,
1548         .twsk_destructor = tcp_twsk_destructor,
1549 };
1550
1551 static const struct inet_connection_sock_af_ops ipv6_specific = {
1552         .queue_xmit        = inet6_csk_xmit,
1553         .send_check        = tcp_v6_send_check,
1554         .rebuild_header    = inet6_sk_rebuild_header,
1555         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1556         .conn_request      = tcp_v6_conn_request,
1557         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1558         .net_header_len    = sizeof(struct ipv6hdr),
1559         .net_frag_header_len = sizeof(struct frag_hdr),
1560         .setsockopt        = ipv6_setsockopt,
1561         .getsockopt        = ipv6_getsockopt,
1562         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1563         .sockaddr_len      = sizeof(struct sockaddr_in6),
1564         .bind_conflict     = inet6_csk_bind_conflict,
1565 #ifdef CONFIG_COMPAT
1566         .compat_setsockopt = compat_ipv6_setsockopt,
1567         .compat_getsockopt = compat_ipv6_getsockopt,
1568 #endif
1569         .mtu_reduced       = tcp_v6_mtu_reduced,
1570 };
1571
1572 #ifdef CONFIG_TCP_MD5SIG
1573 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1574         .md5_lookup     =       tcp_v6_md5_lookup,
1575         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1576         .md5_parse      =       tcp_v6_parse_md5_keys,
1577 };
1578 #endif
1579
1580 /*
1581  *      TCP over IPv4 via INET6 API
1582  */
1583 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1584         .queue_xmit        = ip_queue_xmit,
1585         .send_check        = tcp_v4_send_check,
1586         .rebuild_header    = inet_sk_rebuild_header,
1587         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1588         .conn_request      = tcp_v6_conn_request,
1589         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1590         .net_header_len    = sizeof(struct iphdr),
1591         .setsockopt        = ipv6_setsockopt,
1592         .getsockopt        = ipv6_getsockopt,
1593         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1594         .sockaddr_len      = sizeof(struct sockaddr_in6),
1595         .bind_conflict     = inet6_csk_bind_conflict,
1596 #ifdef CONFIG_COMPAT
1597         .compat_setsockopt = compat_ipv6_setsockopt,
1598         .compat_getsockopt = compat_ipv6_getsockopt,
1599 #endif
1600         .mtu_reduced       = tcp_v4_mtu_reduced,
1601 };
1602
1603 #ifdef CONFIG_TCP_MD5SIG
1604 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1605         .md5_lookup     =       tcp_v4_md5_lookup,
1606         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1607         .md5_parse      =       tcp_v6_parse_md5_keys,
1608 };
1609 #endif
1610
1611 /* NOTE: A lot of things set to zero explicitly by call to
1612  *       sk_alloc() so need not be done here.
1613  */
1614 static int tcp_v6_init_sock(struct sock *sk)
1615 {
1616         struct inet_connection_sock *icsk = inet_csk(sk);
1617
1618         tcp_init_sock(sk);
1619
1620         icsk->icsk_af_ops = &ipv6_specific;
1621
1622 #ifdef CONFIG_TCP_MD5SIG
1623         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1624 #endif
1625
1626         return 0;
1627 }
1628
1629 static void tcp_v6_destroy_sock(struct sock *sk)
1630 {
1631         tcp_v4_destroy_sock(sk);
1632         inet6_destroy_sock(sk);
1633 }
1634
1635 #ifdef CONFIG_PROC_FS
1636 /* Proc filesystem TCPv6 sock list dumping. */
1637 static void get_openreq6(struct seq_file *seq,
1638                          struct request_sock *req, int i, kuid_t uid)
1639 {
1640         long ttd = req->rsk_timer.expires - jiffies;
1641         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1642         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1643
1644         if (ttd < 0)
1645                 ttd = 0;
1646
1647         seq_printf(seq,
1648                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1649                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1650                    i,
1651                    src->s6_addr32[0], src->s6_addr32[1],
1652                    src->s6_addr32[2], src->s6_addr32[3],
1653                    inet_rsk(req)->ir_num,
1654                    dest->s6_addr32[0], dest->s6_addr32[1],
1655                    dest->s6_addr32[2], dest->s6_addr32[3],
1656                    ntohs(inet_rsk(req)->ir_rmt_port),
1657                    TCP_SYN_RECV,
1658                    0, 0, /* could print option size, but that is af dependent. */
1659                    1,   /* timers active (only the expire timer) */
1660                    jiffies_to_clock_t(ttd),
1661                    req->num_timeout,
1662                    from_kuid_munged(seq_user_ns(seq), uid),
1663                    0,  /* non standard timer */
1664                    0, /* open_requests have no inode */
1665                    0, req);
1666 }
1667
1668 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1669 {
1670         const struct in6_addr *dest, *src;
1671         __u16 destp, srcp;
1672         int timer_active;
1673         unsigned long timer_expires;
1674         const struct inet_sock *inet = inet_sk(sp);
1675         const struct tcp_sock *tp = tcp_sk(sp);
1676         const struct inet_connection_sock *icsk = inet_csk(sp);
1677         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1678
1679         dest  = &sp->sk_v6_daddr;
1680         src   = &sp->sk_v6_rcv_saddr;
1681         destp = ntohs(inet->inet_dport);
1682         srcp  = ntohs(inet->inet_sport);
1683
1684         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1685                 timer_active    = 1;
1686                 timer_expires   = icsk->icsk_timeout;
1687         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1688                 timer_active    = 4;
1689                 timer_expires   = icsk->icsk_timeout;
1690         } else if (timer_pending(&sp->sk_timer)) {
1691                 timer_active    = 2;
1692                 timer_expires   = sp->sk_timer.expires;
1693         } else {
1694                 timer_active    = 0;
1695                 timer_expires = jiffies;
1696         }
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 %lu %d %pK %lu %lu %u %u %d\n",
1701                    i,
1702                    src->s6_addr32[0], src->s6_addr32[1],
1703                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1704                    dest->s6_addr32[0], dest->s6_addr32[1],
1705                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1706                    sp->sk_state,
1707                    tp->write_seq-tp->snd_una,
1708                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1709                    timer_active,
1710                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1711                    icsk->icsk_retransmits,
1712                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1713                    icsk->icsk_probes_out,
1714                    sock_i_ino(sp),
1715                    atomic_read(&sp->sk_refcnt), sp,
1716                    jiffies_to_clock_t(icsk->icsk_rto),
1717                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1718                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1719                    tp->snd_cwnd,
1720                    sp->sk_state == TCP_LISTEN ?
1721                         fastopenq->max_qlen :
1722                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1723                    );
1724 }
1725
1726 static void get_timewait6_sock(struct seq_file *seq,
1727                                struct inet_timewait_sock *tw, int i)
1728 {
1729         long delta = tw->tw_timer.expires - jiffies;
1730         const struct in6_addr *dest, *src;
1731         __u16 destp, srcp;
1732
1733         dest = &tw->tw_v6_daddr;
1734         src  = &tw->tw_v6_rcv_saddr;
1735         destp = ntohs(tw->tw_dport);
1736         srcp  = ntohs(tw->tw_sport);
1737
1738         seq_printf(seq,
1739                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1740                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1741                    i,
1742                    src->s6_addr32[0], src->s6_addr32[1],
1743                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1744                    dest->s6_addr32[0], dest->s6_addr32[1],
1745                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1746                    tw->tw_substate, 0, 0,
1747                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1748                    atomic_read(&tw->tw_refcnt), tw);
1749 }
1750
1751 static int tcp6_seq_show(struct seq_file *seq, void *v)
1752 {
1753         struct tcp_iter_state *st;
1754         struct sock *sk = v;
1755
1756         if (v == SEQ_START_TOKEN) {
1757                 seq_puts(seq,
1758                          "  sl  "
1759                          "local_address                         "
1760                          "remote_address                        "
1761                          "st tx_queue rx_queue tr tm->when retrnsmt"
1762                          "   uid  timeout inode\n");
1763                 goto out;
1764         }
1765         st = seq->private;
1766
1767         switch (st->state) {
1768         case TCP_SEQ_STATE_LISTENING:
1769         case TCP_SEQ_STATE_ESTABLISHED:
1770                 if (sk->sk_state == TCP_TIME_WAIT)
1771                         get_timewait6_sock(seq, v, st->num);
1772                 else
1773                         get_tcp6_sock(seq, v, st->num);
1774                 break;
1775         case TCP_SEQ_STATE_OPENREQ:
1776                 get_openreq6(seq, v, st->num, st->uid);
1777                 break;
1778         }
1779 out:
1780         return 0;
1781 }
1782
1783 static const struct file_operations tcp6_afinfo_seq_fops = {
1784         .owner   = THIS_MODULE,
1785         .open    = tcp_seq_open,
1786         .read    = seq_read,
1787         .llseek  = seq_lseek,
1788         .release = seq_release_net
1789 };
1790
1791 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1792         .name           = "tcp6",
1793         .family         = AF_INET6,
1794         .seq_fops       = &tcp6_afinfo_seq_fops,
1795         .seq_ops        = {
1796                 .show           = tcp6_seq_show,
1797         },
1798 };
1799
1800 int __net_init tcp6_proc_init(struct net *net)
1801 {
1802         return tcp_proc_register(net, &tcp6_seq_afinfo);
1803 }
1804
1805 void tcp6_proc_exit(struct net *net)
1806 {
1807         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1808 }
1809 #endif
1810
1811 static void tcp_v6_clear_sk(struct sock *sk, int size)
1812 {
1813         struct inet_sock *inet = inet_sk(sk);
1814
1815         /* we do not want to clear pinet6 field, because of RCU lookups */
1816         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1817
1818         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1819         memset(&inet->pinet6 + 1, 0, size);
1820 }
1821
1822 struct proto tcpv6_prot = {
1823         .name                   = "TCPv6",
1824         .owner                  = THIS_MODULE,
1825         .close                  = tcp_close,
1826         .connect                = tcp_v6_connect,
1827         .disconnect             = tcp_disconnect,
1828         .accept                 = inet_csk_accept,
1829         .ioctl                  = tcp_ioctl,
1830         .init                   = tcp_v6_init_sock,
1831         .destroy                = tcp_v6_destroy_sock,
1832         .shutdown               = tcp_shutdown,
1833         .setsockopt             = tcp_setsockopt,
1834         .getsockopt             = tcp_getsockopt,
1835         .recvmsg                = tcp_recvmsg,
1836         .sendmsg                = tcp_sendmsg,
1837         .sendpage               = tcp_sendpage,
1838         .backlog_rcv            = tcp_v6_do_rcv,
1839         .release_cb             = tcp_release_cb,
1840         .hash                   = inet_hash,
1841         .unhash                 = inet_unhash,
1842         .get_port               = inet_csk_get_port,
1843         .enter_memory_pressure  = tcp_enter_memory_pressure,
1844         .stream_memory_free     = tcp_stream_memory_free,
1845         .sockets_allocated      = &tcp_sockets_allocated,
1846         .memory_allocated       = &tcp_memory_allocated,
1847         .memory_pressure        = &tcp_memory_pressure,
1848         .orphan_count           = &tcp_orphan_count,
1849         .sysctl_mem             = sysctl_tcp_mem,
1850         .sysctl_wmem            = sysctl_tcp_wmem,
1851         .sysctl_rmem            = sysctl_tcp_rmem,
1852         .max_header             = MAX_TCP_HEADER,
1853         .obj_size               = sizeof(struct tcp6_sock),
1854         .slab_flags             = SLAB_DESTROY_BY_RCU,
1855         .twsk_prot              = &tcp6_timewait_sock_ops,
1856         .rsk_prot               = &tcp6_request_sock_ops,
1857         .h.hashinfo             = &tcp_hashinfo,
1858         .no_autobind            = true,
1859 #ifdef CONFIG_COMPAT
1860         .compat_setsockopt      = compat_tcp_setsockopt,
1861         .compat_getsockopt      = compat_tcp_getsockopt,
1862 #endif
1863 #ifdef CONFIG_MEMCG_KMEM
1864         .proto_cgroup           = tcp_proto_cgroup,
1865 #endif
1866         .clear_sk               = tcp_v6_clear_sk,
1867 };
1868
1869 static const struct inet6_protocol tcpv6_protocol = {
1870         .early_demux    =       tcp_v6_early_demux,
1871         .handler        =       tcp_v6_rcv,
1872         .err_handler    =       tcp_v6_err,
1873         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1874 };
1875
1876 static struct inet_protosw tcpv6_protosw = {
1877         .type           =       SOCK_STREAM,
1878         .protocol       =       IPPROTO_TCP,
1879         .prot           =       &tcpv6_prot,
1880         .ops            =       &inet6_stream_ops,
1881         .flags          =       INET_PROTOSW_PERMANENT |
1882                                 INET_PROTOSW_ICSK,
1883 };
1884
1885 static int __net_init tcpv6_net_init(struct net *net)
1886 {
1887         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1888                                     SOCK_RAW, IPPROTO_TCP, net);
1889 }
1890
1891 static void __net_exit tcpv6_net_exit(struct net *net)
1892 {
1893         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1894 }
1895
1896 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1897 {
1898         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1899 }
1900
1901 static struct pernet_operations tcpv6_net_ops = {
1902         .init       = tcpv6_net_init,
1903         .exit       = tcpv6_net_exit,
1904         .exit_batch = tcpv6_net_exit_batch,
1905 };
1906
1907 int __init tcpv6_init(void)
1908 {
1909         int ret;
1910
1911         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1912         if (ret)
1913                 goto out;
1914
1915         /* register inet6 protocol */
1916         ret = inet6_register_protosw(&tcpv6_protosw);
1917         if (ret)
1918                 goto out_tcpv6_protocol;
1919
1920         ret = register_pernet_subsys(&tcpv6_net_ops);
1921         if (ret)
1922                 goto out_tcpv6_protosw;
1923 out:
1924         return ret;
1925
1926 out_tcpv6_protosw:
1927         inet6_unregister_protosw(&tcpv6_protosw);
1928 out_tcpv6_protocol:
1929         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1930         goto out;
1931 }
1932
1933 void tcpv6_exit(void)
1934 {
1935         unregister_pernet_subsys(&tcpv6_net_ops);
1936         inet6_unregister_protosw(&tcpv6_protosw);
1937         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1938 }