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 ipv6_txoptions *opt;
 124         struct flowi6 fl6;
 125         struct dst_entry *dst;
 126         int addr_type;
 127         int err;
 128
 129         if (addr_len < SIN6_LEN_RFC2133)
 130                 return -EINVAL;
 131
 132         if (usin->sin6_family != AF_INET6)
 133                 return -EAFNOSUPPORT;
 134
 135         memset(&fl6, 0, sizeof(fl6));
 136
 137         if (np->sndflow) {
 138                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 139                 IP6_ECN_flow_init(fl6.flowlabel);
 140                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 141                         struct ip6_flowlabel *flowlabel;
 142                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 143                         if (!flowlabel)
 144                                 return -EINVAL;
 145                         fl6_sock_release(flowlabel);
 146                 }
 147         }
 148
 149         /*
 150          *      connect() to INADDR_ANY means loopback (BSD'ism).
 151          */
 152
 153         if (ipv6_addr_any(&usin->sin6_addr))
 154                 usin->sin6_addr.s6_addr[15] = 0x1;
 155
 156         addr_type = ipv6_addr_type(&usin->sin6_addr);
 157
 158         if (addr_type & IPV6_ADDR_MULTICAST)
 159                 return -ENETUNREACH;
 160
 161         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 162                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 163                     usin->sin6_scope_id) {
 164                         /* If interface is set while binding, indices
 165                          * must coincide.
 166                          */
 167                         if (sk->sk_bound_dev_if &&
 168                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 169                                 return -EINVAL;
 170
 171                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 172                 }
 173
 174                 /* Connect to link-local address requires an interface */
 175                 if (!sk->sk_bound_dev_if)
 176                         return -EINVAL;
 177         }
 178
 179         if (tp->rx_opt.ts_recent_stamp &&
 180             !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 181                 tp->rx_opt.ts_recent = 0;
 182                 tp->rx_opt.ts_recent_stamp = 0;
 183                 tp->write_seq = 0;
 184         }
 185
 186         sk->sk_v6_daddr = usin->sin6_addr;
 187         np->flow_label = fl6.flowlabel;
 188
 189         /*
 190          *      TCP over IPv4
 191          */
 192
 193         if (addr_type == IPV6_ADDR_MAPPED) {
 194                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 195                 struct sockaddr_in sin;
 196
 197                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 198
 199                 if (__ipv6_only_sock(sk))
 200                         return -ENETUNREACH;
 201
 202                 sin.sin_family = AF_INET;
 203                 sin.sin_port = usin->sin6_port;
 204                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 205
 206                 icsk->icsk_af_ops = &ipv6_mapped;
 207                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 208 #ifdef CONFIG_TCP_MD5SIG
 209                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 210 #endif
 211
 212                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 213
 214                 if (err) {
 215                         icsk->icsk_ext_hdr_len = exthdrlen;
 216                         icsk->icsk_af_ops = &ipv6_specific;
 217                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 218 #ifdef CONFIG_TCP_MD5SIG
 219                         tp->af_specific = &tcp_sock_ipv6_specific;
 220 #endif
 221                         goto failure;
 222                 }
 223                 np->saddr = sk->sk_v6_rcv_saddr;
 224
 225                 return err;
 226         }
 227
 228         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 229                 saddr = &sk->sk_v6_rcv_saddr;
 230
 231         fl6.flowi6_proto = IPPROTO_TCP;
 232         fl6.daddr = sk->sk_v6_daddr;
 233         fl6.saddr = saddr ? *saddr : np->saddr;
 234         fl6.flowi6_oif = sk->sk_bound_dev_if;
 235         fl6.flowi6_mark = sk->sk_mark;
 236         fl6.fl6_dport = usin->sin6_port;
 237         fl6.fl6_sport = inet->inet_sport;
 238
 239         opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
 240         final_p = fl6_update_dst(&fl6, opt, &final);
 241
 242         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 243
 244         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 245         if (IS_ERR(dst)) {
 246                 err = PTR_ERR(dst);
 247                 goto failure;
 248         }
 249
 250         if (!saddr) {
 251                 saddr = &fl6.saddr;
 252                 sk->sk_v6_rcv_saddr = *saddr;
 253         }
 254
 255         /* set the source address */
 256         np->saddr = *saddr;
 257         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 258
 259         sk->sk_gso_type = SKB_GSO_TCPV6;
 260         ip6_dst_store(sk, dst, NULL, NULL);
 261
 262         if (tcp_death_row.sysctl_tw_recycle &&
 263             !tp->rx_opt.ts_recent_stamp &&
 264             ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
 265                 tcp_fetch_timewait_stamp(sk, dst);
 266
 267         icsk->icsk_ext_hdr_len = 0;
 268         if (opt)
 269                 icsk->icsk_ext_hdr_len = opt->opt_flen +
 270                                          opt->opt_nflen;
 271
 272         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 273
 274         inet->inet_dport = usin->sin6_port;
 275
 276         tcp_set_state(sk, TCP_SYN_SENT);
 277         err = inet6_hash_connect(&tcp_death_row, sk);
 278         if (err)
 279                 goto late_failure;
 280
 281         sk_set_txhash(sk);
 282
 283         if (!tp->write_seq && likely(!tp->repair))
 284                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 285                                                              sk->sk_v6_daddr.s6_addr32,
 286                                                              inet->inet_sport,
 287                                                              inet->inet_dport);
 288
 289         err = tcp_connect(sk);
 290         if (err)
 291                 goto late_failure;
 292
 293         return 0;
 294
 295 late_failure:
 296         tcp_set_state(sk, TCP_CLOSE);
 297         __sk_dst_reset(sk);
 298 failure:
 299         inet->inet_dport = 0;
 300         sk->sk_route_caps = 0;
 301         return err;
 302 }
 303
 304 static void tcp_v6_mtu_reduced(struct sock *sk)
 305 {
 306         struct dst_entry *dst;
 307
 308         if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 309                 return;
 310
 311         dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
 312         if (!dst)
 313                 return;
 314
 315         if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 316                 tcp_sync_mss(sk, dst_mtu(dst));
 317                 tcp_simple_retransmit(sk);
 318         }
 319 }
 320
 321 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 322                 u8 type, u8 code, int offset, __be32 info)
 323 {
 324         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 325         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 326         struct net *net = dev_net(skb->dev);
 327         struct request_sock *fastopen;
 328         struct ipv6_pinfo *np;
 329         struct tcp_sock *tp;
 330         __u32 seq, snd_una;
 331         struct sock *sk;
 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_BH(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         if (sk->sk_state == TCP_NEW_SYN_RECV)
 351                 return tcp_req_err(sk, seq);
 352
 353         bh_lock_sock(sk);
 354         if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 355                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 356
 357         if (sk->sk_state == TCP_CLOSE)
 358                 goto out;
 359
 360         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 361                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 362                 goto out;
 363         }
 364
 365         tp = tcp_sk(sk);
 366         /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 367         fastopen = tp->fastopen_rsk;
 368         snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 369         if (sk->sk_state != TCP_LISTEN &&
 370             !between(seq, snd_una, tp->snd_nxt)) {
 371                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 372                 goto out;
 373         }
 374
 375         np = inet6_sk(sk);
 376
 377         if (type == NDISC_REDIRECT) {
 378                 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 379
 380                 if (dst)
 381                         dst->ops->redirect(dst, sk, skb);
 382                 goto out;
 383         }
 384
 385         if (type == ICMPV6_PKT_TOOBIG) {
 386                 /* We are not interested in TCP_LISTEN and open_requests
 387                  * (SYN-ACKs send out by Linux are always <576bytes so
 388                  * they should go through unfragmented).
 389                  */
 390                 if (sk->sk_state == TCP_LISTEN)
 391                         goto out;
 392
 393                 if (!ip6_sk_accept_pmtu(sk))
 394                         goto out;
 395
 396                 tp->mtu_info = ntohl(info);
 397                 if (!sock_owned_by_user(sk))
 398                         tcp_v6_mtu_reduced(sk);
 399                 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 400                                            &tp->tsq_flags))
 401                         sock_hold(sk);
 402                 goto out;
 403         }
 404
 405         icmpv6_err_convert(type, code, &err);
 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                               bool attach_req)
 444 {
 445         struct inet_request_sock *ireq = inet_rsk(req);
 446         struct ipv6_pinfo *np = inet6_sk(sk);
 447         struct flowi6 *fl6 = &fl->u.ip6;
 448         struct sk_buff *skb;
 449         int err = -ENOMEM;
 450
 451         /* First, grab a route. */
 452         if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
 453                                                IPPROTO_TCP)) == NULL)
 454                 goto done;
 455
 456         skb = tcp_make_synack(sk, dst, req, foc, attach_req);
 457
 458         if (skb) {
 459                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 460                                     &ireq->ir_v6_rmt_addr);
 461
 462                 fl6->daddr = ireq->ir_v6_rmt_addr;
 463                 if (np->repflow && ireq->pktopts)
 464                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 465
 466                 err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt),
 467                                np->tclass);
 468                 err = net_xmit_eval(err);
 469         }
 470
 471 done:
 472         return err;
 473 }
 474
 475
 476 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 477 {
 478         kfree_skb(inet_rsk(req)->pktopts);
 479 }
 480
 481 #ifdef CONFIG_TCP_MD5SIG
 482 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 483                                                    const struct in6_addr *addr)
 484 {
 485         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 486 }
 487
 488 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 489                                                 const struct sock *addr_sk)
 490 {
 491         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 492 }
 493
 494 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 495                                  int optlen)
 496 {
 497         struct tcp_md5sig cmd;
 498         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 499
 500         if (optlen < sizeof(cmd))
 501                 return -EINVAL;
 502
 503         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 504                 return -EFAULT;
 505
 506         if (sin6->sin6_family != AF_INET6)
 507                 return -EINVAL;
 508
 509         if (!cmd.tcpm_keylen) {
 510                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 511                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 512                                               AF_INET);
 513                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 514                                       AF_INET6);
 515         }
 516
 517         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 518                 return -EINVAL;
 519
 520         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 521                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 522                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 523
 524         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 525                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 526 }
 527
 528 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 529                                         const struct in6_addr *daddr,
 530                                         const struct in6_addr *saddr, int nbytes)
 531 {
 532         struct tcp6_pseudohdr *bp;
 533         struct scatterlist sg;
 534
 535         bp = &hp->md5_blk.ip6;
 536         /* 1. TCP pseudo-header (RFC2460) */
 537         bp->saddr = *saddr;
 538         bp->daddr = *daddr;
 539         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 540         bp->len = cpu_to_be32(nbytes);
 541
 542         sg_init_one(&sg, bp, sizeof(*bp));
 543         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 544 }
 545
 546 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 547                                const struct in6_addr *daddr, struct in6_addr *saddr,
 548                                const struct tcphdr *th)
 549 {
 550         struct tcp_md5sig_pool *hp;
 551         struct hash_desc *desc;
 552
 553         hp = tcp_get_md5sig_pool();
 554         if (!hp)
 555                 goto clear_hash_noput;
 556         desc = &hp->md5_desc;
 557
 558         if (crypto_hash_init(desc))
 559                 goto clear_hash;
 560         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 561                 goto clear_hash;
 562         if (tcp_md5_hash_header(hp, th))
 563                 goto clear_hash;
 564         if (tcp_md5_hash_key(hp, key))
 565                 goto clear_hash;
 566         if (crypto_hash_final(desc, md5_hash))
 567                 goto clear_hash;
 568
 569         tcp_put_md5sig_pool();
 570         return 0;
 571
 572 clear_hash:
 573         tcp_put_md5sig_pool();
 574 clear_hash_noput:
 575         memset(md5_hash, 0, 16);
 576         return 1;
 577 }
 578
 579 static int tcp_v6_md5_hash_skb(char *md5_hash,
 580                                const struct tcp_md5sig_key *key,
 581                                const struct sock *sk,
 582                                const struct sk_buff *skb)
 583 {
 584         const struct in6_addr *saddr, *daddr;
 585         struct tcp_md5sig_pool *hp;
 586         struct hash_desc *desc;
 587         const struct tcphdr *th = tcp_hdr(skb);
 588
 589         if (sk) { /* valid for establish/request sockets */
 590                 saddr = &sk->sk_v6_rcv_saddr;
 591                 daddr = &sk->sk_v6_daddr;
 592         } else {
 593                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 594                 saddr = &ip6h->saddr;
 595                 daddr = &ip6h->daddr;
 596         }
 597
 598         hp = tcp_get_md5sig_pool();
 599         if (!hp)
 600                 goto clear_hash_noput;
 601         desc = &hp->md5_desc;
 602
 603         if (crypto_hash_init(desc))
 604                 goto clear_hash;
 605
 606         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 607                 goto clear_hash;
 608         if (tcp_md5_hash_header(hp, th))
 609                 goto clear_hash;
 610         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 611                 goto clear_hash;
 612         if (tcp_md5_hash_key(hp, key))
 613                 goto clear_hash;
 614         if (crypto_hash_final(desc, md5_hash))
 615                 goto clear_hash;
 616
 617         tcp_put_md5sig_pool();
 618         return 0;
 619
 620 clear_hash:
 621         tcp_put_md5sig_pool();
 622 clear_hash_noput:
 623         memset(md5_hash, 0, 16);
 624         return 1;
 625 }
 626
 627 #endif
 628
 629 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
 630                                     const struct sk_buff *skb)
 631 {
 632 #ifdef CONFIG_TCP_MD5SIG
 633         const __u8 *hash_location = NULL;
 634         struct tcp_md5sig_key *hash_expected;
 635         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 636         const struct tcphdr *th = tcp_hdr(skb);
 637         int genhash;
 638         u8 newhash[16];
 639
 640         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 641         hash_location = tcp_parse_md5sig_option(th);
 642
 643         /* We've parsed the options - do we have a hash? */
 644         if (!hash_expected && !hash_location)
 645                 return false;
 646
 647         if (hash_expected && !hash_location) {
 648                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 649                 return true;
 650         }
 651
 652         if (!hash_expected && hash_location) {
 653                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 654                 return true;
 655         }
 656
 657         /* check the signature */
 658         genhash = tcp_v6_md5_hash_skb(newhash,
 659                                       hash_expected,
 660                                       NULL, skb);
 661
 662         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 663                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 664                                      genhash ? "failed" : "mismatch",
 665                                      &ip6h->saddr, ntohs(th->source),
 666                                      &ip6h->daddr, ntohs(th->dest));
 667                 return true;
 668         }
 669 #endif
 670         return false;
 671 }
 672
 673 static void tcp_v6_init_req(struct request_sock *req,
 674                             const struct sock *sk_listener,
 675                             struct sk_buff *skb)
 676 {
 677         struct inet_request_sock *ireq = inet_rsk(req);
 678         const struct ipv6_pinfo *np = inet6_sk(sk_listener);
 679
 680         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 681         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 682
 683         /* So that link locals have meaning */
 684         if (!sk_listener->sk_bound_dev_if &&
 685             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 686                 ireq->ir_iif = tcp_v6_iif(skb);
 687
 688         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 689             (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 690              np->rxopt.bits.rxinfo ||
 691              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 692              np->rxopt.bits.rxohlim || np->repflow)) {
 693                 atomic_inc(&skb->users);
 694                 ireq->pktopts = skb;
 695         }
 696 }
 697
 698 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 699                                           struct flowi *fl,
 700                                           const struct request_sock *req,
 701                                           bool *strict)
 702 {
 703         if (strict)
 704                 *strict = true;
 705         return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 706 }
 707
 708 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 709         .family         =       AF_INET6,
 710         .obj_size       =       sizeof(struct tcp6_request_sock),
 711         .rtx_syn_ack    =       tcp_rtx_synack,
 712         .send_ack       =       tcp_v6_reqsk_send_ack,
 713         .destructor     =       tcp_v6_reqsk_destructor,
 714         .send_reset     =       tcp_v6_send_reset,
 715         .syn_ack_timeout =      tcp_syn_ack_timeout,
 716 };
 717
 718 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 719         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 720                                 sizeof(struct ipv6hdr),
 721 #ifdef CONFIG_TCP_MD5SIG
 722         .req_md5_lookup =       tcp_v6_md5_lookup,
 723         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 724 #endif
 725         .init_req       =       tcp_v6_init_req,
 726 #ifdef CONFIG_SYN_COOKIES
 727         .cookie_init_seq =      cookie_v6_init_sequence,
 728 #endif
 729         .route_req      =       tcp_v6_route_req,
 730         .init_seq       =       tcp_v6_init_sequence,
 731         .send_synack    =       tcp_v6_send_synack,
 732 };
 733
 734 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 735                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 736                                  int oif, struct tcp_md5sig_key *key, int rst,
 737                                  u8 tclass, u32 label)
 738 {
 739         const struct tcphdr *th = tcp_hdr(skb);
 740         struct tcphdr *t1;
 741         struct sk_buff *buff;
 742         struct flowi6 fl6;
 743         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 744         struct sock *ctl_sk = net->ipv6.tcp_sk;
 745         unsigned int tot_len = sizeof(struct tcphdr);
 746         struct dst_entry *dst;
 747         __be32 *topt;
 748
 749         if (tsecr)
 750                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 751 #ifdef CONFIG_TCP_MD5SIG
 752         if (key)
 753                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 754 #endif
 755
 756         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 757                          GFP_ATOMIC);
 758         if (!buff)
 759                 return;
 760
 761         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 762
 763         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 764         skb_reset_transport_header(buff);
 765
 766         /* Swap the send and the receive. */
 767         memset(t1, 0, sizeof(*t1));
 768         t1->dest = th->source;
 769         t1->source = th->dest;
 770         t1->doff = tot_len / 4;
 771         t1->seq = htonl(seq);
 772         t1->ack_seq = htonl(ack);
 773         t1->ack = !rst || !th->ack;
 774         t1->rst = rst;
 775         t1->window = htons(win);
 776
 777         topt = (__be32 *)(t1 + 1);
 778
 779         if (tsecr) {
 780                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 781                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 782                 *topt++ = htonl(tsval);
 783                 *topt++ = htonl(tsecr);
 784         }
 785
 786 #ifdef CONFIG_TCP_MD5SIG
 787         if (key) {
 788                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 789                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 790                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 791                                     &ipv6_hdr(skb)->saddr,
 792                                     &ipv6_hdr(skb)->daddr, t1);
 793         }
 794 #endif
 795
 796         memset(&fl6, 0, sizeof(fl6));
 797         fl6.daddr = ipv6_hdr(skb)->saddr;
 798         fl6.saddr = ipv6_hdr(skb)->daddr;
 799         fl6.flowlabel = label;
 800
 801         buff->ip_summed = CHECKSUM_PARTIAL;
 802         buff->csum = 0;
 803
 804         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 805
 806         fl6.flowi6_proto = IPPROTO_TCP;
 807         if (rt6_need_strict(&fl6.daddr) && !oif)
 808                 fl6.flowi6_oif = tcp_v6_iif(skb);
 809         else
 810                 fl6.flowi6_oif = oif;
 811         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 812         fl6.fl6_dport = t1->dest;
 813         fl6.fl6_sport = t1->source;
 814         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 815
 816         /* Pass a socket to ip6_dst_lookup either it is for RST
 817          * Underlying function will use this to retrieve the network
 818          * namespace
 819          */
 820         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 821         if (!IS_ERR(dst)) {
 822                 skb_dst_set(buff, dst);
 823                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 824                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 825                 if (rst)
 826                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 827                 return;
 828         }
 829
 830         kfree_skb(buff);
 831 }
 832
 833 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 834 {
 835         const struct tcphdr *th = tcp_hdr(skb);
 836         u32 seq = 0, ack_seq = 0;
 837         struct tcp_md5sig_key *key = NULL;
 838 #ifdef CONFIG_TCP_MD5SIG
 839         const __u8 *hash_location = NULL;
 840         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 841         unsigned char newhash[16];
 842         int genhash;
 843         struct sock *sk1 = NULL;
 844 #endif
 845         int oif;
 846
 847         if (th->rst)
 848                 return;
 849
 850         /* If sk not NULL, it means we did a successful lookup and incoming
 851          * route had to be correct. prequeue might have dropped our dst.
 852          */
 853         if (!sk && !ipv6_unicast_destination(skb))
 854                 return;
 855
 856 #ifdef CONFIG_TCP_MD5SIG
 857         hash_location = tcp_parse_md5sig_option(th);
 858         if (!sk && hash_location) {
 859                 /*
 860                  * active side is lost. Try to find listening socket through
 861                  * source port, and then find md5 key through listening socket.
 862                  * we are not loose security here:
 863                  * Incoming packet is checked with md5 hash with finding key,
 864                  * no RST generated if md5 hash doesn't match.
 865                  */
 866                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 867                                            &tcp_hashinfo, &ipv6h->saddr,
 868                                            th->source, &ipv6h->daddr,
 869                                            ntohs(th->source), tcp_v6_iif(skb));
 870                 if (!sk1)
 871                         return;
 872
 873                 rcu_read_lock();
 874                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 875                 if (!key)
 876                         goto release_sk1;
 877
 878                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 879                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 880                         goto release_sk1;
 881         } else {
 882                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 883         }
 884 #endif
 885
 886         if (th->ack)
 887                 seq = ntohl(th->ack_seq);
 888         else
 889                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 890                           (th->doff << 2);
 891
 892         oif = sk ? sk->sk_bound_dev_if : 0;
 893         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 894
 895 #ifdef CONFIG_TCP_MD5SIG
 896 release_sk1:
 897         if (sk1) {
 898                 rcu_read_unlock();
 899                 sock_put(sk1);
 900         }
 901 #endif
 902 }
 903
 904 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
 905                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 906                             struct tcp_md5sig_key *key, u8 tclass,
 907                             u32 label)
 908 {
 909         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 910                              tclass, label);
 911 }
 912
 913 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 914 {
 915         struct inet_timewait_sock *tw = inet_twsk(sk);
 916         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 917
 918         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 919                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 920                         tcp_time_stamp + tcptw->tw_ts_offset,
 921                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 922                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 923
 924         inet_twsk_put(tw);
 925 }
 926
 927 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
 928                                   struct request_sock *req)
 929 {
 930         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 931          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 932          */
 933         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 934                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 935                         tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd,
 936                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 937                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 938                         0, 0);
 939 }
 940
 941
 942 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
 943 {
 944 #ifdef CONFIG_SYN_COOKIES
 945         const struct tcphdr *th = tcp_hdr(skb);
 946
 947         if (!th->syn)
 948                 sk = cookie_v6_check(sk, skb);
 949 #endif
 950         return sk;
 951 }
 952
 953 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 954 {
 955         if (skb->protocol == htons(ETH_P_IP))
 956                 return tcp_v4_conn_request(sk, skb);
 957
 958         if (!ipv6_unicast_destination(skb))
 959                 goto drop;
 960
 961         return tcp_conn_request(&tcp6_request_sock_ops,
 962                                 &tcp_request_sock_ipv6_ops, sk, skb);
 963
 964 drop:
 965         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 966         return 0; /* don't send reset */
 967 }
 968
 969 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 970                                          struct request_sock *req,
 971                                          struct dst_entry *dst,
 972                                          struct request_sock *req_unhash,
 973                                          bool *own_req)
 974 {
 975         struct inet_request_sock *ireq;
 976         struct ipv6_pinfo *newnp;
 977         const struct ipv6_pinfo *np = inet6_sk(sk);
 978         struct ipv6_txoptions *opt;
 979         struct tcp6_sock *newtcp6sk;
 980         struct inet_sock *newinet;
 981         struct tcp_sock *newtp;
 982         struct sock *newsk;
 983 #ifdef CONFIG_TCP_MD5SIG
 984         struct tcp_md5sig_key *key;
 985 #endif
 986         struct flowi6 fl6;
 987
 988         if (skb->protocol == htons(ETH_P_IP)) {
 989                 /*
 990                  *      v6 mapped
 991                  */
 992
 993                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
 994                                              req_unhash, own_req);
 995
 996                 if (!newsk)
 997                         return NULL;
 998
 999                 newtcp6sk = (struct tcp6_sock *)newsk;
1000                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1001
1002                 newinet = inet_sk(newsk);
1003                 newnp = inet6_sk(newsk);
1004                 newtp = tcp_sk(newsk);
1005
1006                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1007
1008                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1009
1010                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1011                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1012 #ifdef CONFIG_TCP_MD5SIG
1013                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1014 #endif
1015
1016                 newnp->ipv6_ac_list = NULL;
1017                 newnp->ipv6_fl_list = NULL;
1018                 newnp->pktoptions  = NULL;
1019                 newnp->opt         = NULL;
1020                 newnp->mcast_oif   = tcp_v6_iif(skb);
1021                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1022                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1023                 if (np->repflow)
1024                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1025
1026                 /*
1027                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1028                  * here, tcp_create_openreq_child now does this for us, see the comment in
1029                  * that function for the gory details. -acme
1030                  */
1031
1032                 /* It is tricky place. Until this moment IPv4 tcp
1033                    worked with IPv6 icsk.icsk_af_ops.
1034                    Sync it now.
1035                  */
1036                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1037
1038                 return newsk;
1039         }
1040
1041         ireq = inet_rsk(req);
1042
1043         if (sk_acceptq_is_full(sk))
1044                 goto out_overflow;
1045
1046         if (!dst) {
1047                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1048                 if (!dst)
1049                         goto out;
1050         }
1051
1052         newsk = tcp_create_openreq_child(sk, req, skb);
1053         if (!newsk)
1054                 goto out_nonewsk;
1055
1056         /*
1057          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1058          * count here, tcp_create_openreq_child now does this for us, see the
1059          * comment in that function for the gory details. -acme
1060          */
1061
1062         newsk->sk_gso_type = SKB_GSO_TCPV6;
1063         ip6_dst_store(newsk, dst, NULL, NULL);
1064         inet6_sk_rx_dst_set(newsk, skb);
1065
1066         newtcp6sk = (struct tcp6_sock *)newsk;
1067         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1068
1069         newtp = tcp_sk(newsk);
1070         newinet = inet_sk(newsk);
1071         newnp = inet6_sk(newsk);
1072
1073         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1074
1075         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1076         newnp->saddr = ireq->ir_v6_loc_addr;
1077         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1078         newsk->sk_bound_dev_if = ireq->ir_iif;
1079
1080         /* Now IPv6 options...
1081
1082            First: no IPv4 options.
1083          */
1084         newinet->inet_opt = NULL;
1085         newnp->ipv6_ac_list = NULL;
1086         newnp->ipv6_fl_list = NULL;
1087
1088         /* Clone RX bits */
1089         newnp->rxopt.all = np->rxopt.all;
1090
1091         newnp->pktoptions = NULL;
1092         newnp->opt        = NULL;
1093         newnp->mcast_oif  = tcp_v6_iif(skb);
1094         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1095         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1096         if (np->repflow)
1097                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1098
1099         /* Clone native IPv6 options from listening socket (if any)
1100
1101            Yes, keeping reference count would be much more clever,
1102            but we make one more one thing there: reattach optmem
1103            to newsk.
1104          */
1105         opt = rcu_dereference(np->opt);
1106         if (opt) {
1107                 opt = ipv6_dup_options(newsk, opt);
1108                 RCU_INIT_POINTER(newnp->opt, opt);
1109         }
1110         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1111         if (opt)
1112                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1113                                                     opt->opt_flen;
1114
1115         tcp_ca_openreq_child(newsk, dst);
1116
1117         tcp_sync_mss(newsk, dst_mtu(dst));
1118         newtp->advmss = dst_metric_advmss(dst);
1119         if (tcp_sk(sk)->rx_opt.user_mss &&
1120             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1121                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1122
1123         tcp_initialize_rcv_mss(newsk);
1124
1125         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1126         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1127
1128 #ifdef CONFIG_TCP_MD5SIG
1129         /* Copy over the MD5 key from the original socket */
1130         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1131         if (key) {
1132                 /* We're using one, so create a matching key
1133                  * on the newsk structure. If we fail to get
1134                  * memory, then we end up not copying the key
1135                  * across. Shucks.
1136                  */
1137                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1138                                AF_INET6, key->key, key->keylen,
1139                                sk_gfp_atomic(sk, GFP_ATOMIC));
1140         }
1141 #endif
1142
1143         if (__inet_inherit_port(sk, newsk) < 0) {
1144                 inet_csk_prepare_forced_close(newsk);
1145                 tcp_done(newsk);
1146                 goto out;
1147         }
1148         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1149         if (*own_req) {
1150                 tcp_move_syn(newtp, req);
1151
1152                 /* Clone pktoptions received with SYN, if we own the req */
1153                 if (ireq->pktopts) {
1154                         newnp->pktoptions = skb_clone(ireq->pktopts,
1155                                                       sk_gfp_atomic(sk, GFP_ATOMIC));
1156                         consume_skb(ireq->pktopts);
1157                         ireq->pktopts = NULL;
1158                         if (newnp->pktoptions)
1159                                 skb_set_owner_r(newnp->pktoptions, newsk);
1160                 }
1161         }
1162
1163         return newsk;
1164
1165 out_overflow:
1166         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1167 out_nonewsk:
1168         dst_release(dst);
1169 out:
1170         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1171         return NULL;
1172 }
1173
1174 /* The socket must have it's spinlock held when we get
1175  * here, unless it is a TCP_LISTEN socket.
1176  *
1177  * We have a potential double-lock case here, so even when
1178  * doing backlog processing we use the BH locking scheme.
1179  * This is because we cannot sleep with the original spinlock
1180  * held.
1181  */
1182 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1183 {
1184         struct ipv6_pinfo *np = inet6_sk(sk);
1185         struct tcp_sock *tp;
1186         struct sk_buff *opt_skb = NULL;
1187
1188         /* Imagine: socket is IPv6. IPv4 packet arrives,
1189            goes to IPv4 receive handler and backlogged.
1190            From backlog it always goes here. Kerboom...
1191            Fortunately, tcp_rcv_established and rcv_established
1192            handle them correctly, but it is not case with
1193            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1194          */
1195
1196         if (skb->protocol == htons(ETH_P_IP))
1197                 return tcp_v4_do_rcv(sk, skb);
1198
1199         if (sk_filter(sk, skb))
1200                 goto discard;
1201
1202         /*
1203          *      socket locking is here for SMP purposes as backlog rcv
1204          *      is currently called with bh processing disabled.
1205          */
1206
1207         /* Do Stevens' IPV6_PKTOPTIONS.
1208
1209            Yes, guys, it is the only place in our code, where we
1210            may make it not affecting IPv4.
1211            The rest of code is protocol independent,
1212            and I do not like idea to uglify IPv4.
1213
1214            Actually, all the idea behind IPV6_PKTOPTIONS
1215            looks not very well thought. For now we latch
1216            options, received in the last packet, enqueued
1217            by tcp. Feel free to propose better solution.
1218                                                --ANK (980728)
1219          */
1220         if (np->rxopt.all)
1221                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1222
1223         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1224                 struct dst_entry *dst = sk->sk_rx_dst;
1225
1226                 sock_rps_save_rxhash(sk, skb);
1227                 sk_mark_napi_id(sk, skb);
1228                 if (dst) {
1229                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1230                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1231                                 dst_release(dst);
1232                                 sk->sk_rx_dst = NULL;
1233                         }
1234                 }
1235
1236                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1237                 if (opt_skb)
1238                         goto ipv6_pktoptions;
1239                 return 0;
1240         }
1241
1242         if (tcp_checksum_complete(skb))
1243                 goto csum_err;
1244
1245         if (sk->sk_state == TCP_LISTEN) {
1246                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1247
1248                 if (!nsk)
1249                         goto discard;
1250
1251                 if (nsk != sk) {
1252                         sock_rps_save_rxhash(nsk, skb);
1253                         sk_mark_napi_id(nsk, skb);
1254                         if (tcp_child_process(sk, nsk, skb))
1255                                 goto reset;
1256                         if (opt_skb)
1257                                 __kfree_skb(opt_skb);
1258                         return 0;
1259                 }
1260         } else
1261                 sock_rps_save_rxhash(sk, skb);
1262
1263         if (tcp_rcv_state_process(sk, skb))
1264                 goto reset;
1265         if (opt_skb)
1266                 goto ipv6_pktoptions;
1267         return 0;
1268
1269 reset:
1270         tcp_v6_send_reset(sk, skb);
1271 discard:
1272         if (opt_skb)
1273                 __kfree_skb(opt_skb);
1274         kfree_skb(skb);
1275         return 0;
1276 csum_err:
1277         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1278         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1279         goto discard;
1280
1281
1282 ipv6_pktoptions:
1283         /* Do you ask, what is it?
1284
1285            1. skb was enqueued by tcp.
1286            2. skb is added to tail of read queue, rather than out of order.
1287            3. socket is not in passive state.
1288            4. Finally, it really contains options, which user wants to receive.
1289          */
1290         tp = tcp_sk(sk);
1291         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1292             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1293                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1294                         np->mcast_oif = tcp_v6_iif(opt_skb);
1295                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1296                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1297                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1298                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1299                 if (np->repflow)
1300                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1301                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1302                         skb_set_owner_r(opt_skb, sk);
1303                         opt_skb = xchg(&np->pktoptions, opt_skb);
1304                 } else {
1305                         __kfree_skb(opt_skb);
1306                         opt_skb = xchg(&np->pktoptions, NULL);
1307                 }
1308         }
1309
1310         kfree_skb(opt_skb);
1311         return 0;
1312 }
1313
1314 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1315                            const struct tcphdr *th)
1316 {
1317         /* This is tricky: we move IP6CB at its correct location into
1318          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1319          * _decode_session6() uses IP6CB().
1320          * barrier() makes sure compiler won't play aliasing games.
1321          */
1322         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1323                 sizeof(struct inet6_skb_parm));
1324         barrier();
1325
1326         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1327         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1328                                     skb->len - th->doff*4);
1329         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1330         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1331         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1332         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1333         TCP_SKB_CB(skb)->sacked = 0;
1334 }
1335
1336 static void tcp_v6_restore_cb(struct sk_buff *skb)
1337 {
1338         /* We need to move header back to the beginning if xfrm6_policy_check()
1339          * and tcp_v6_fill_cb() are going to be called again.
1340          */
1341         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1342                 sizeof(struct inet6_skb_parm));
1343 }
1344
1345 static int tcp_v6_rcv(struct sk_buff *skb)
1346 {
1347         const struct tcphdr *th;
1348         const struct ipv6hdr *hdr;
1349         struct sock *sk;
1350         int ret;
1351         struct net *net = dev_net(skb->dev);
1352
1353         if (skb->pkt_type != PACKET_HOST)
1354                 goto discard_it;
1355
1356         /*
1357          *      Count it even if it's bad.
1358          */
1359         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1360
1361         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1362                 goto discard_it;
1363
1364         th = tcp_hdr(skb);
1365
1366         if (th->doff < sizeof(struct tcphdr)/4)
1367                 goto bad_packet;
1368         if (!pskb_may_pull(skb, th->doff*4))
1369                 goto discard_it;
1370
1371         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1372                 goto csum_error;
1373
1374         th = tcp_hdr(skb);
1375         hdr = ipv6_hdr(skb);
1376
1377 lookup:
1378         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1379                                 inet6_iif(skb));
1380         if (!sk)
1381                 goto no_tcp_socket;
1382
1383 process:
1384         if (sk->sk_state == TCP_TIME_WAIT)
1385                 goto do_time_wait;
1386
1387         if (sk->sk_state == TCP_NEW_SYN_RECV) {
1388                 struct request_sock *req = inet_reqsk(sk);
1389                 struct sock *nsk = NULL;
1390
1391                 sk = req->rsk_listener;
1392                 tcp_v6_fill_cb(skb, hdr, th);
1393                 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1394                         reqsk_put(req);
1395                         goto discard_it;
1396                 }
1397                 if (likely(sk->sk_state == TCP_LISTEN)) {
1398                         nsk = tcp_check_req(sk, skb, req, false);
1399                 } else {
1400                         inet_csk_reqsk_queue_drop_and_put(sk, req);
1401                         goto lookup;
1402                 }
1403                 if (!nsk) {
1404                         reqsk_put(req);
1405                         goto discard_it;
1406                 }
1407                 if (nsk == sk) {
1408                         sock_hold(sk);
1409                         reqsk_put(req);
1410                         tcp_v6_restore_cb(skb);
1411                 } else if (tcp_child_process(sk, nsk, skb)) {
1412                         tcp_v6_send_reset(nsk, skb);
1413                         goto discard_it;
1414                 } else {
1415                         return 0;
1416                 }
1417         }
1418         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1419                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1420                 goto discard_and_relse;
1421         }
1422
1423         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1424                 goto discard_and_relse;
1425
1426         tcp_v6_fill_cb(skb, hdr, th);
1427
1428         if (tcp_v6_inbound_md5_hash(sk, skb))
1429                 goto discard_and_relse;
1430
1431         if (sk_filter(sk, skb))
1432                 goto discard_and_relse;
1433
1434         skb->dev = NULL;
1435
1436         if (sk->sk_state == TCP_LISTEN) {
1437                 ret = tcp_v6_do_rcv(sk, skb);
1438                 goto put_and_return;
1439         }
1440
1441         sk_incoming_cpu_update(sk);
1442
1443         bh_lock_sock_nested(sk);
1444         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1445         ret = 0;
1446         if (!sock_owned_by_user(sk)) {
1447                 if (!tcp_prequeue(sk, skb))
1448                         ret = tcp_v6_do_rcv(sk, skb);
1449         } else if (unlikely(sk_add_backlog(sk, skb,
1450                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1451                 bh_unlock_sock(sk);
1452                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1453                 goto discard_and_relse;
1454         }
1455         bh_unlock_sock(sk);
1456
1457 put_and_return:
1458         sock_put(sk);
1459         return ret ? -1 : 0;
1460
1461 no_tcp_socket:
1462         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1463                 goto discard_it;
1464
1465         tcp_v6_fill_cb(skb, hdr, th);
1466
1467         if (tcp_checksum_complete(skb)) {
1468 csum_error:
1469                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1470 bad_packet:
1471                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1472         } else {
1473                 tcp_v6_send_reset(NULL, skb);
1474         }
1475
1476 discard_it:
1477         kfree_skb(skb);
1478         return 0;
1479
1480 discard_and_relse:
1481         sock_put(sk);
1482         goto discard_it;
1483
1484 do_time_wait:
1485         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1486                 inet_twsk_put(inet_twsk(sk));
1487                 goto discard_it;
1488         }
1489
1490         tcp_v6_fill_cb(skb, hdr, th);
1491
1492         if (tcp_checksum_complete(skb)) {
1493                 inet_twsk_put(inet_twsk(sk));
1494                 goto csum_error;
1495         }
1496
1497         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1498         case TCP_TW_SYN:
1499         {
1500                 struct sock *sk2;
1501
1502                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1503                                             &ipv6_hdr(skb)->saddr, th->source,
1504                                             &ipv6_hdr(skb)->daddr,
1505                                             ntohs(th->dest), tcp_v6_iif(skb));
1506                 if (sk2) {
1507                         struct inet_timewait_sock *tw = inet_twsk(sk);
1508                         inet_twsk_deschedule_put(tw);
1509                         sk = sk2;
1510                         tcp_v6_restore_cb(skb);
1511                         goto process;
1512                 }
1513                 /* Fall through to ACK */
1514         }
1515         case TCP_TW_ACK:
1516                 tcp_v6_timewait_ack(sk, skb);
1517                 break;
1518         case TCP_TW_RST:
1519                 tcp_v6_restore_cb(skb);
1520                 goto no_tcp_socket;
1521         case TCP_TW_SUCCESS:
1522                 ;
1523         }
1524         goto discard_it;
1525 }
1526
1527 static void tcp_v6_early_demux(struct sk_buff *skb)
1528 {
1529         const struct ipv6hdr *hdr;
1530         const struct tcphdr *th;
1531         struct sock *sk;
1532
1533         if (skb->pkt_type != PACKET_HOST)
1534                 return;
1535
1536         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1537                 return;
1538
1539         hdr = ipv6_hdr(skb);
1540         th = tcp_hdr(skb);
1541
1542         if (th->doff < sizeof(struct tcphdr) / 4)
1543                 return;
1544
1545         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1546         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1547                                         &hdr->saddr, th->source,
1548                                         &hdr->daddr, ntohs(th->dest),
1549                                         inet6_iif(skb));
1550         if (sk) {
1551                 skb->sk = sk;
1552                 skb->destructor = sock_edemux;
1553                 if (sk_fullsock(sk)) {
1554                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1555
1556                         if (dst)
1557                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1558                         if (dst &&
1559                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1560                                 skb_dst_set_noref(skb, dst);
1561                 }
1562         }
1563 }
1564
1565 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1566         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1567         .twsk_unique    = tcp_twsk_unique,
1568         .twsk_destructor = tcp_twsk_destructor,
1569 };
1570
1571 static const struct inet_connection_sock_af_ops ipv6_specific = {
1572         .queue_xmit        = inet6_csk_xmit,
1573         .send_check        = tcp_v6_send_check,
1574         .rebuild_header    = inet6_sk_rebuild_header,
1575         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1576         .conn_request      = tcp_v6_conn_request,
1577         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1578         .net_header_len    = sizeof(struct ipv6hdr),
1579         .net_frag_header_len = sizeof(struct frag_hdr),
1580         .setsockopt        = ipv6_setsockopt,
1581         .getsockopt        = ipv6_getsockopt,
1582         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1583         .sockaddr_len      = sizeof(struct sockaddr_in6),
1584         .bind_conflict     = inet6_csk_bind_conflict,
1585 #ifdef CONFIG_COMPAT
1586         .compat_setsockopt = compat_ipv6_setsockopt,
1587         .compat_getsockopt = compat_ipv6_getsockopt,
1588 #endif
1589         .mtu_reduced       = tcp_v6_mtu_reduced,
1590 };
1591
1592 #ifdef CONFIG_TCP_MD5SIG
1593 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1594         .md5_lookup     =       tcp_v6_md5_lookup,
1595         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1596         .md5_parse      =       tcp_v6_parse_md5_keys,
1597 };
1598 #endif
1599
1600 /*
1601  *      TCP over IPv4 via INET6 API
1602  */
1603 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1604         .queue_xmit        = ip_queue_xmit,
1605         .send_check        = tcp_v4_send_check,
1606         .rebuild_header    = inet_sk_rebuild_header,
1607         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1608         .conn_request      = tcp_v6_conn_request,
1609         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1610         .net_header_len    = sizeof(struct iphdr),
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_v4_mtu_reduced,
1621 };
1622
1623 #ifdef CONFIG_TCP_MD5SIG
1624 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1625         .md5_lookup     =       tcp_v4_md5_lookup,
1626         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1627         .md5_parse      =       tcp_v6_parse_md5_keys,
1628 };
1629 #endif
1630
1631 /* NOTE: A lot of things set to zero explicitly by call to
1632  *       sk_alloc() so need not be done here.
1633  */
1634 static int tcp_v6_init_sock(struct sock *sk)
1635 {
1636         struct inet_connection_sock *icsk = inet_csk(sk);
1637
1638         tcp_init_sock(sk);
1639
1640         icsk->icsk_af_ops = &ipv6_specific;
1641
1642 #ifdef CONFIG_TCP_MD5SIG
1643         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1644 #endif
1645
1646         return 0;
1647 }
1648
1649 static void tcp_v6_destroy_sock(struct sock *sk)
1650 {
1651         tcp_v4_destroy_sock(sk);
1652         inet6_destroy_sock(sk);
1653 }
1654
1655 #ifdef CONFIG_PROC_FS
1656 /* Proc filesystem TCPv6 sock list dumping. */
1657 static void get_openreq6(struct seq_file *seq,
1658                          const struct request_sock *req, int i)
1659 {
1660         long ttd = req->rsk_timer.expires - jiffies;
1661         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1662         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1663
1664         if (ttd < 0)
1665                 ttd = 0;
1666
1667         seq_printf(seq,
1668                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1669                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1670                    i,
1671                    src->s6_addr32[0], src->s6_addr32[1],
1672                    src->s6_addr32[2], src->s6_addr32[3],
1673                    inet_rsk(req)->ir_num,
1674                    dest->s6_addr32[0], dest->s6_addr32[1],
1675                    dest->s6_addr32[2], dest->s6_addr32[3],
1676                    ntohs(inet_rsk(req)->ir_rmt_port),
1677                    TCP_SYN_RECV,
1678                    0, 0, /* could print option size, but that is af dependent. */
1679                    1,   /* timers active (only the expire timer) */
1680                    jiffies_to_clock_t(ttd),
1681                    req->num_timeout,
1682                    from_kuid_munged(seq_user_ns(seq),
1683                                     sock_i_uid(req->rsk_listener)),
1684                    0,  /* non standard timer */
1685                    0, /* open_requests have no inode */
1686                    0, req);
1687 }
1688
1689 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1690 {
1691         const struct in6_addr *dest, *src;
1692         __u16 destp, srcp;
1693         int timer_active;
1694         unsigned long timer_expires;
1695         const struct inet_sock *inet = inet_sk(sp);
1696         const struct tcp_sock *tp = tcp_sk(sp);
1697         const struct inet_connection_sock *icsk = inet_csk(sp);
1698         const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1699         int rx_queue;
1700         int state;
1701
1702         dest  = &sp->sk_v6_daddr;
1703         src   = &sp->sk_v6_rcv_saddr;
1704         destp = ntohs(inet->inet_dport);
1705         srcp  = ntohs(inet->inet_sport);
1706
1707         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1708                 timer_active    = 1;
1709                 timer_expires   = icsk->icsk_timeout;
1710         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1711                 timer_active    = 4;
1712                 timer_expires   = icsk->icsk_timeout;
1713         } else if (timer_pending(&sp->sk_timer)) {
1714                 timer_active    = 2;
1715                 timer_expires   = sp->sk_timer.expires;
1716         } else {
1717                 timer_active    = 0;
1718                 timer_expires = jiffies;
1719         }
1720
1721         state = sk_state_load(sp);
1722         if (state == TCP_LISTEN)
1723                 rx_queue = sp->sk_ack_backlog;
1724         else
1725                 /* Because we don't lock the socket,
1726                  * we might find a transient negative value.
1727                  */
1728                 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1729
1730         seq_printf(seq,
1731                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1732                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1733                    i,
1734                    src->s6_addr32[0], src->s6_addr32[1],
1735                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1736                    dest->s6_addr32[0], dest->s6_addr32[1],
1737                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1738                    state,
1739                    tp->write_seq - tp->snd_una,
1740                    rx_queue,
1741                    timer_active,
1742                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1743                    icsk->icsk_retransmits,
1744                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1745                    icsk->icsk_probes_out,
1746                    sock_i_ino(sp),
1747                    atomic_read(&sp->sk_refcnt), sp,
1748                    jiffies_to_clock_t(icsk->icsk_rto),
1749                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1750                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1751                    tp->snd_cwnd,
1752                    state == TCP_LISTEN ?
1753                         fastopenq->max_qlen :
1754                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1755                    );
1756 }
1757
1758 static void get_timewait6_sock(struct seq_file *seq,
1759                                struct inet_timewait_sock *tw, int i)
1760 {
1761         long delta = tw->tw_timer.expires - jiffies;
1762         const struct in6_addr *dest, *src;
1763         __u16 destp, srcp;
1764
1765         dest = &tw->tw_v6_daddr;
1766         src  = &tw->tw_v6_rcv_saddr;
1767         destp = ntohs(tw->tw_dport);
1768         srcp  = ntohs(tw->tw_sport);
1769
1770         seq_printf(seq,
1771                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1772                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1773                    i,
1774                    src->s6_addr32[0], src->s6_addr32[1],
1775                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1776                    dest->s6_addr32[0], dest->s6_addr32[1],
1777                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1778                    tw->tw_substate, 0, 0,
1779                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1780                    atomic_read(&tw->tw_refcnt), tw);
1781 }
1782
1783 static int tcp6_seq_show(struct seq_file *seq, void *v)
1784 {
1785         struct tcp_iter_state *st;
1786         struct sock *sk = v;
1787
1788         if (v == SEQ_START_TOKEN) {
1789                 seq_puts(seq,
1790                          "  sl  "
1791                          "local_address                         "
1792                          "remote_address                        "
1793                          "st tx_queue rx_queue tr tm->when retrnsmt"
1794                          "   uid  timeout inode\n");
1795                 goto out;
1796         }
1797         st = seq->private;
1798
1799         if (sk->sk_state == TCP_TIME_WAIT)
1800                 get_timewait6_sock(seq, v, st->num);
1801         else if (sk->sk_state == TCP_NEW_SYN_RECV)
1802                 get_openreq6(seq, v, st->num);
1803         else
1804                 get_tcp6_sock(seq, v, st->num);
1805 out:
1806         return 0;
1807 }
1808
1809 static const struct file_operations tcp6_afinfo_seq_fops = {
1810         .owner   = THIS_MODULE,
1811         .open    = tcp_seq_open,
1812         .read    = seq_read,
1813         .llseek  = seq_lseek,
1814         .release = seq_release_net
1815 };
1816
1817 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1818         .name           = "tcp6",
1819         .family         = AF_INET6,
1820         .seq_fops       = &tcp6_afinfo_seq_fops,
1821         .seq_ops        = {
1822                 .show           = tcp6_seq_show,
1823         },
1824 };
1825
1826 int __net_init tcp6_proc_init(struct net *net)
1827 {
1828         return tcp_proc_register(net, &tcp6_seq_afinfo);
1829 }
1830
1831 void tcp6_proc_exit(struct net *net)
1832 {
1833         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1834 }
1835 #endif
1836
1837 static void tcp_v6_clear_sk(struct sock *sk, int size)
1838 {
1839         struct inet_sock *inet = inet_sk(sk);
1840
1841         /* we do not want to clear pinet6 field, because of RCU lookups */
1842         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1843
1844         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1845         memset(&inet->pinet6 + 1, 0, size);
1846 }
1847
1848 struct proto tcpv6_prot = {
1849         .name                   = "TCPv6",
1850         .owner                  = THIS_MODULE,
1851         .close                  = tcp_close,
1852         .connect                = tcp_v6_connect,
1853         .disconnect             = tcp_disconnect,
1854         .accept                 = inet_csk_accept,
1855         .ioctl                  = tcp_ioctl,
1856         .init                   = tcp_v6_init_sock,
1857         .destroy                = tcp_v6_destroy_sock,
1858         .shutdown               = tcp_shutdown,
1859         .setsockopt             = tcp_setsockopt,
1860         .getsockopt             = tcp_getsockopt,
1861         .recvmsg                = tcp_recvmsg,
1862         .sendmsg                = tcp_sendmsg,
1863         .sendpage               = tcp_sendpage,
1864         .backlog_rcv            = tcp_v6_do_rcv,
1865         .release_cb             = tcp_release_cb,
1866         .hash                   = inet_hash,
1867         .unhash                 = inet_unhash,
1868         .get_port               = inet_csk_get_port,
1869         .enter_memory_pressure  = tcp_enter_memory_pressure,
1870         .stream_memory_free     = tcp_stream_memory_free,
1871         .sockets_allocated      = &tcp_sockets_allocated,
1872         .memory_allocated       = &tcp_memory_allocated,
1873         .memory_pressure        = &tcp_memory_pressure,
1874         .orphan_count           = &tcp_orphan_count,
1875         .sysctl_mem             = sysctl_tcp_mem,
1876         .sysctl_wmem            = sysctl_tcp_wmem,
1877         .sysctl_rmem            = sysctl_tcp_rmem,
1878         .max_header             = MAX_TCP_HEADER,
1879         .obj_size               = sizeof(struct tcp6_sock),
1880         .slab_flags             = SLAB_DESTROY_BY_RCU,
1881         .twsk_prot              = &tcp6_timewait_sock_ops,
1882         .rsk_prot               = &tcp6_request_sock_ops,
1883         .h.hashinfo             = &tcp_hashinfo,
1884         .no_autobind            = true,
1885 #ifdef CONFIG_COMPAT
1886         .compat_setsockopt      = compat_tcp_setsockopt,
1887         .compat_getsockopt      = compat_tcp_getsockopt,
1888 #endif
1889 #ifdef CONFIG_MEMCG_KMEM
1890         .proto_cgroup           = tcp_proto_cgroup,
1891 #endif
1892         .clear_sk               = tcp_v6_clear_sk,
1893 };
1894
1895 static const struct inet6_protocol tcpv6_protocol = {
1896         .early_demux    =       tcp_v6_early_demux,
1897         .handler        =       tcp_v6_rcv,
1898         .err_handler    =       tcp_v6_err,
1899         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1900 };
1901
1902 static struct inet_protosw tcpv6_protosw = {
1903         .type           =       SOCK_STREAM,
1904         .protocol       =       IPPROTO_TCP,
1905         .prot           =       &tcpv6_prot,
1906         .ops            =       &inet6_stream_ops,
1907         .flags          =       INET_PROTOSW_PERMANENT |
1908                                 INET_PROTOSW_ICSK,
1909 };
1910
1911 static int __net_init tcpv6_net_init(struct net *net)
1912 {
1913         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1914                                     SOCK_RAW, IPPROTO_TCP, net);
1915 }
1916
1917 static void __net_exit tcpv6_net_exit(struct net *net)
1918 {
1919         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1920 }
1921
1922 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1923 {
1924         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1925 }
1926
1927 static struct pernet_operations tcpv6_net_ops = {
1928         .init       = tcpv6_net_init,
1929         .exit       = tcpv6_net_exit,
1930         .exit_batch = tcpv6_net_exit_batch,
1931 };
1932
1933 int __init tcpv6_init(void)
1934 {
1935         int ret;
1936
1937         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1938         if (ret)
1939                 goto out;
1940
1941         /* register inet6 protocol */
1942         ret = inet6_register_protosw(&tcpv6_protosw);
1943         if (ret)
1944                 goto out_tcpv6_protocol;
1945
1946         ret = register_pernet_subsys(&tcpv6_net_ops);
1947         if (ret)
1948                 goto out_tcpv6_protosw;
1949 out:
1950         return ret;
1951
1952 out_tcpv6_protosw:
1953         inet6_unregister_protosw(&tcpv6_protosw);
1954 out_tcpv6_protocol:
1955         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1956         goto out;
1957 }
1958
1959 void tcpv6_exit(void)
1960 {
1961         unregister_pernet_subsys(&tcpv6_net_ops);
1962         inet6_unregister_protosw(&tcpv6_protosw);
1963         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1964 }