net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/inet_common.h>
  63 #include <net/secure_seq.h>
  64 #include <net/tcp_memcontrol.h>
  65 #include <net/busy_poll.h>
  66
  67 #include <linux/proc_fs.h>
  68 #include <linux/seq_file.h>
  69
  70 #include <linux/crypto.h>
  71 #include <linux/scatterlist.h>
  72
  73 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  74 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  75                                       struct request_sock *req);
  76
  77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  78
  79 static const struct inet_connection_sock_af_ops ipv6_mapped;
  80 static const struct inet_connection_sock_af_ops ipv6_specific;
  81 #ifdef CONFIG_TCP_MD5SIG
  82 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  83 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  84 #else
  85 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  86                                                    const struct in6_addr *addr)
  87 {
  88         return NULL;
  89 }
  90 #endif
  91
  92 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  93 {
  94         struct dst_entry *dst = skb_dst(skb);
  95
  96         if (dst) {
  97                 const struct rt6_info *rt = (const struct rt6_info *)dst;
  98
  99                 dst_hold(dst);
 100                 sk->sk_rx_dst = dst;
 101                 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
 102                 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 rt6_info *rt;
 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         final_p = fl6_update_dst(&fl6, np->opt, &final);
 240
 241         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 242
 243         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 244         if (IS_ERR(dst)) {
 245                 err = PTR_ERR(dst);
 246                 goto failure;
 247         }
 248
 249         if (!saddr) {
 250                 saddr = &fl6.saddr;
 251                 sk->sk_v6_rcv_saddr = *saddr;
 252         }
 253
 254         /* set the source address */
 255         np->saddr = *saddr;
 256         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 257
 258         sk->sk_gso_type = SKB_GSO_TCPV6;
 259         __ip6_dst_store(sk, dst, NULL, NULL);
 260
 261         rt = (struct rt6_info *) dst;
 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 (np->opt)
 269                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 270                                           np->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         ip6_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(struct sock *sk, struct dst_entry *dst,
 440                               struct flowi *fl,
 441                               struct request_sock *req,
 442                               u16 queue_mapping,
 443                               struct tcp_fastopen_cookie *foc)
 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)) == NULL)
 453                 goto done;
 454
 455         skb = tcp_make_synack(sk, dst, req, foc);
 456
 457         if (skb) {
 458                 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 459                                     &ireq->ir_v6_rmt_addr);
 460
 461                 fl6->daddr = ireq->ir_v6_rmt_addr;
 462                 if (np->repflow && ireq->pktopts)
 463                         fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 464
 465                 skb_set_queue_mapping(skb, queue_mapping);
 466                 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
 467                 err = net_xmit_eval(err);
 468         }
 469
 470 done:
 471         return err;
 472 }
 473
 474
 475 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 476 {
 477         kfree_skb(inet_rsk(req)->pktopts);
 478 }
 479
 480 #ifdef CONFIG_TCP_MD5SIG
 481 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 482                                                    const struct in6_addr *addr)
 483 {
 484         return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
 485 }
 486
 487 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 488                                                 const struct sock *addr_sk)
 489 {
 490         return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 491 }
 492
 493 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 494                                  int optlen)
 495 {
 496         struct tcp_md5sig cmd;
 497         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 498
 499         if (optlen < sizeof(cmd))
 500                 return -EINVAL;
 501
 502         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 503                 return -EFAULT;
 504
 505         if (sin6->sin6_family != AF_INET6)
 506                 return -EINVAL;
 507
 508         if (!cmd.tcpm_keylen) {
 509                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 510                         return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 511                                               AF_INET);
 512                 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 513                                       AF_INET6);
 514         }
 515
 516         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 517                 return -EINVAL;
 518
 519         if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 520                 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 521                                       AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 522
 523         return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 524                               AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 525 }
 526
 527 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 528                                         const struct in6_addr *daddr,
 529                                         const struct in6_addr *saddr, int nbytes)
 530 {
 531         struct tcp6_pseudohdr *bp;
 532         struct scatterlist sg;
 533
 534         bp = &hp->md5_blk.ip6;
 535         /* 1. TCP pseudo-header (RFC2460) */
 536         bp->saddr = *saddr;
 537         bp->daddr = *daddr;
 538         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 539         bp->len = cpu_to_be32(nbytes);
 540
 541         sg_init_one(&sg, bp, sizeof(*bp));
 542         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 543 }
 544
 545 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 546                                const struct in6_addr *daddr, struct in6_addr *saddr,
 547                                const struct tcphdr *th)
 548 {
 549         struct tcp_md5sig_pool *hp;
 550         struct hash_desc *desc;
 551
 552         hp = tcp_get_md5sig_pool();
 553         if (!hp)
 554                 goto clear_hash_noput;
 555         desc = &hp->md5_desc;
 556
 557         if (crypto_hash_init(desc))
 558                 goto clear_hash;
 559         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 560                 goto clear_hash;
 561         if (tcp_md5_hash_header(hp, th))
 562                 goto clear_hash;
 563         if (tcp_md5_hash_key(hp, key))
 564                 goto clear_hash;
 565         if (crypto_hash_final(desc, md5_hash))
 566                 goto clear_hash;
 567
 568         tcp_put_md5sig_pool();
 569         return 0;
 570
 571 clear_hash:
 572         tcp_put_md5sig_pool();
 573 clear_hash_noput:
 574         memset(md5_hash, 0, 16);
 575         return 1;
 576 }
 577
 578 static int tcp_v6_md5_hash_skb(char *md5_hash,
 579                                const struct tcp_md5sig_key *key,
 580                                const struct sock *sk,
 581                                const struct sk_buff *skb)
 582 {
 583         const struct in6_addr *saddr, *daddr;
 584         struct tcp_md5sig_pool *hp;
 585         struct hash_desc *desc;
 586         const struct tcphdr *th = tcp_hdr(skb);
 587
 588         if (sk) { /* valid for establish/request sockets */
 589                 saddr = &sk->sk_v6_rcv_saddr;
 590                 daddr = &sk->sk_v6_daddr;
 591         } else {
 592                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 593                 saddr = &ip6h->saddr;
 594                 daddr = &ip6h->daddr;
 595         }
 596
 597         hp = tcp_get_md5sig_pool();
 598         if (!hp)
 599                 goto clear_hash_noput;
 600         desc = &hp->md5_desc;
 601
 602         if (crypto_hash_init(desc))
 603                 goto clear_hash;
 604
 605         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 606                 goto clear_hash;
 607         if (tcp_md5_hash_header(hp, th))
 608                 goto clear_hash;
 609         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 610                 goto clear_hash;
 611         if (tcp_md5_hash_key(hp, key))
 612                 goto clear_hash;
 613         if (crypto_hash_final(desc, md5_hash))
 614                 goto clear_hash;
 615
 616         tcp_put_md5sig_pool();
 617         return 0;
 618
 619 clear_hash:
 620         tcp_put_md5sig_pool();
 621 clear_hash_noput:
 622         memset(md5_hash, 0, 16);
 623         return 1;
 624 }
 625
 626 static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 627 {
 628         const __u8 *hash_location = NULL;
 629         struct tcp_md5sig_key *hash_expected;
 630         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 631         const struct tcphdr *th = tcp_hdr(skb);
 632         int genhash;
 633         u8 newhash[16];
 634
 635         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 636         hash_location = tcp_parse_md5sig_option(th);
 637
 638         /* We've parsed the options - do we have a hash? */
 639         if (!hash_expected && !hash_location)
 640                 return false;
 641
 642         if (hash_expected && !hash_location) {
 643                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 644                 return true;
 645         }
 646
 647         if (!hash_expected && hash_location) {
 648                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 649                 return true;
 650         }
 651
 652         /* check the signature */
 653         genhash = tcp_v6_md5_hash_skb(newhash,
 654                                       hash_expected,
 655                                       NULL, skb);
 656
 657         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 658                 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 659                                      genhash ? "failed" : "mismatch",
 660                                      &ip6h->saddr, ntohs(th->source),
 661                                      &ip6h->daddr, ntohs(th->dest));
 662                 return true;
 663         }
 664         return false;
 665 }
 666 #endif
 667
 668 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
 669                             struct sk_buff *skb)
 670 {
 671         struct inet_request_sock *ireq = inet_rsk(req);
 672         struct ipv6_pinfo *np = inet6_sk(sk);
 673
 674         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 675         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 676
 677         /* So that link locals have meaning */
 678         if (!sk->sk_bound_dev_if &&
 679             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 680                 ireq->ir_iif = tcp_v6_iif(skb);
 681
 682         if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 683             (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
 684              np->rxopt.bits.rxinfo ||
 685              np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 686              np->rxopt.bits.rxohlim || np->repflow)) {
 687                 atomic_inc(&skb->users);
 688                 ireq->pktopts = skb;
 689         }
 690 }
 691
 692 static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl,
 693                                           const struct request_sock *req,
 694                                           bool *strict)
 695 {
 696         if (strict)
 697                 *strict = true;
 698         return inet6_csk_route_req(sk, &fl->u.ip6, req);
 699 }
 700
 701 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 702         .family         =       AF_INET6,
 703         .obj_size       =       sizeof(struct tcp6_request_sock),
 704         .rtx_syn_ack    =       tcp_rtx_synack,
 705         .send_ack       =       tcp_v6_reqsk_send_ack,
 706         .destructor     =       tcp_v6_reqsk_destructor,
 707         .send_reset     =       tcp_v6_send_reset,
 708         .syn_ack_timeout =      tcp_syn_ack_timeout,
 709 };
 710
 711 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 712         .mss_clamp      =       IPV6_MIN_MTU - sizeof(struct tcphdr) -
 713                                 sizeof(struct ipv6hdr),
 714 #ifdef CONFIG_TCP_MD5SIG
 715         .req_md5_lookup =       tcp_v6_md5_lookup,
 716         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 717 #endif
 718         .init_req       =       tcp_v6_init_req,
 719 #ifdef CONFIG_SYN_COOKIES
 720         .cookie_init_seq =      cookie_v6_init_sequence,
 721 #endif
 722         .route_req      =       tcp_v6_route_req,
 723         .init_seq       =       tcp_v6_init_sequence,
 724         .send_synack    =       tcp_v6_send_synack,
 725         .queue_hash_add =       inet6_csk_reqsk_queue_hash_add,
 726 };
 727
 728 static void tcp_v6_send_response(struct sock *sk, struct sk_buff *skb, u32 seq,
 729                                  u32 ack, u32 win, u32 tsval, u32 tsecr,
 730                                  int oif, struct tcp_md5sig_key *key, int rst,
 731                                  u8 tclass, u32 label)
 732 {
 733         const struct tcphdr *th = tcp_hdr(skb);
 734         struct tcphdr *t1;
 735         struct sk_buff *buff;
 736         struct flowi6 fl6;
 737         struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 738         struct sock *ctl_sk = net->ipv6.tcp_sk;
 739         unsigned int tot_len = sizeof(struct tcphdr);
 740         struct dst_entry *dst;
 741         __be32 *topt;
 742
 743         if (tsecr)
 744                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 745 #ifdef CONFIG_TCP_MD5SIG
 746         if (key)
 747                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 748 #endif
 749
 750         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 751                          GFP_ATOMIC);
 752         if (!buff)
 753                 return;
 754
 755         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 756
 757         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 758         skb_reset_transport_header(buff);
 759
 760         /* Swap the send and the receive. */
 761         memset(t1, 0, sizeof(*t1));
 762         t1->dest = th->source;
 763         t1->source = th->dest;
 764         t1->doff = tot_len / 4;
 765         t1->seq = htonl(seq);
 766         t1->ack_seq = htonl(ack);
 767         t1->ack = !rst || !th->ack;
 768         t1->rst = rst;
 769         t1->window = htons(win);
 770
 771         topt = (__be32 *)(t1 + 1);
 772
 773         if (tsecr) {
 774                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 775                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 776                 *topt++ = htonl(tsval);
 777                 *topt++ = htonl(tsecr);
 778         }
 779
 780 #ifdef CONFIG_TCP_MD5SIG
 781         if (key) {
 782                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 783                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 784                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
 785                                     &ipv6_hdr(skb)->saddr,
 786                                     &ipv6_hdr(skb)->daddr, t1);
 787         }
 788 #endif
 789
 790         memset(&fl6, 0, sizeof(fl6));
 791         fl6.daddr = ipv6_hdr(skb)->saddr;
 792         fl6.saddr = ipv6_hdr(skb)->daddr;
 793         fl6.flowlabel = label;
 794
 795         buff->ip_summed = CHECKSUM_PARTIAL;
 796         buff->csum = 0;
 797
 798         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 799
 800         fl6.flowi6_proto = IPPROTO_TCP;
 801         if (rt6_need_strict(&fl6.daddr) && !oif)
 802                 fl6.flowi6_oif = tcp_v6_iif(skb);
 803         else
 804                 fl6.flowi6_oif = oif;
 805         fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
 806         fl6.fl6_dport = t1->dest;
 807         fl6.fl6_sport = t1->source;
 808         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 809
 810         /* Pass a socket to ip6_dst_lookup either it is for RST
 811          * Underlying function will use this to retrieve the network
 812          * namespace
 813          */
 814         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
 815         if (!IS_ERR(dst)) {
 816                 skb_dst_set(buff, dst);
 817                 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
 818                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 819                 if (rst)
 820                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
 821                 return;
 822         }
 823
 824         kfree_skb(buff);
 825 }
 826
 827 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 828 {
 829         const struct tcphdr *th = tcp_hdr(skb);
 830         u32 seq = 0, ack_seq = 0;
 831         struct tcp_md5sig_key *key = NULL;
 832 #ifdef CONFIG_TCP_MD5SIG
 833         const __u8 *hash_location = NULL;
 834         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 835         unsigned char newhash[16];
 836         int genhash;
 837         struct sock *sk1 = NULL;
 838 #endif
 839         int oif;
 840
 841         if (th->rst)
 842                 return;
 843
 844         /* If sk not NULL, it means we did a successful lookup and incoming
 845          * route had to be correct. prequeue might have dropped our dst.
 846          */
 847         if (!sk && !ipv6_unicast_destination(skb))
 848                 return;
 849
 850 #ifdef CONFIG_TCP_MD5SIG
 851         hash_location = tcp_parse_md5sig_option(th);
 852         if (!sk && hash_location) {
 853                 /*
 854                  * active side is lost. Try to find listening socket through
 855                  * source port, and then find md5 key through listening socket.
 856                  * we are not loose security here:
 857                  * Incoming packet is checked with md5 hash with finding key,
 858                  * no RST generated if md5 hash doesn't match.
 859                  */
 860                 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
 861                                            &tcp_hashinfo, &ipv6h->saddr,
 862                                            th->source, &ipv6h->daddr,
 863                                            ntohs(th->source), tcp_v6_iif(skb));
 864                 if (!sk1)
 865                         return;
 866
 867                 rcu_read_lock();
 868                 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
 869                 if (!key)
 870                         goto release_sk1;
 871
 872                 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 873                 if (genhash || memcmp(hash_location, newhash, 16) != 0)
 874                         goto release_sk1;
 875         } else {
 876                 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
 877         }
 878 #endif
 879
 880         if (th->ack)
 881                 seq = ntohl(th->ack_seq);
 882         else
 883                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
 884                           (th->doff << 2);
 885
 886         oif = sk ? sk->sk_bound_dev_if : 0;
 887         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 888
 889 #ifdef CONFIG_TCP_MD5SIG
 890 release_sk1:
 891         if (sk1) {
 892                 rcu_read_unlock();
 893                 sock_put(sk1);
 894         }
 895 #endif
 896 }
 897
 898 static void tcp_v6_send_ack(struct sock *sk, struct sk_buff *skb, u32 seq,
 899                             u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
 900                             struct tcp_md5sig_key *key, u8 tclass,
 901                             u32 label)
 902 {
 903         tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
 904                              tclass, label);
 905 }
 906
 907 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
 908 {
 909         struct inet_timewait_sock *tw = inet_twsk(sk);
 910         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
 911
 912         tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
 913                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
 914                         tcp_time_stamp + tcptw->tw_ts_offset,
 915                         tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
 916                         tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
 917
 918         inet_twsk_put(tw);
 919 }
 920
 921 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
 922                                   struct request_sock *req)
 923 {
 924         /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
 925          * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
 926          */
 927         tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
 928                         tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
 929                         tcp_rsk(req)->rcv_nxt, req->rcv_wnd,
 930                         tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
 931                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
 932                         0, 0);
 933 }
 934
 935
 936 static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
 937 {
 938         const struct tcphdr *th = tcp_hdr(skb);
 939         struct request_sock *req;
 940         struct sock *nsk;
 941
 942         /* Find possible connection requests. */
 943         req = inet6_csk_search_req(sk, th->source,
 944                                    &ipv6_hdr(skb)->saddr,
 945                                    &ipv6_hdr(skb)->daddr, tcp_v6_iif(skb));
 946         if (req) {
 947                 nsk = tcp_check_req(sk, skb, req, false);
 948                 if (!nsk)
 949                         reqsk_put(req);
 950                 return nsk;
 951         }
 952         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
 953                                          &ipv6_hdr(skb)->saddr, th->source,
 954                                          &ipv6_hdr(skb)->daddr, ntohs(th->dest),
 955                                          tcp_v6_iif(skb));
 956
 957         if (nsk) {
 958                 if (nsk->sk_state != TCP_TIME_WAIT) {
 959                         bh_lock_sock(nsk);
 960                         return nsk;
 961                 }
 962                 inet_twsk_put(inet_twsk(nsk));
 963                 return NULL;
 964         }
 965
 966 #ifdef CONFIG_SYN_COOKIES
 967         if (!th->syn)
 968                 sk = cookie_v6_check(sk, skb);
 969 #endif
 970         return sk;
 971 }
 972
 973 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 974 {
 975         if (skb->protocol == htons(ETH_P_IP))
 976                 return tcp_v4_conn_request(sk, skb);
 977
 978         if (!ipv6_unicast_destination(skb))
 979                 goto drop;
 980
 981         return tcp_conn_request(&tcp6_request_sock_ops,
 982                                 &tcp_request_sock_ipv6_ops, sk, skb);
 983
 984 drop:
 985         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 986         return 0; /* don't send reset */
 987 }
 988
 989 static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 990                                          struct request_sock *req,
 991                                          struct dst_entry *dst)
 992 {
 993         struct inet_request_sock *ireq;
 994         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 995         struct tcp6_sock *newtcp6sk;
 996         struct inet_sock *newinet;
 997         struct tcp_sock *newtp;
 998         struct sock *newsk;
 999 #ifdef CONFIG_TCP_MD5SIG
1000         struct tcp_md5sig_key *key;
1001 #endif
1002         struct flowi6 fl6;
1003
1004         if (skb->protocol == htons(ETH_P_IP)) {
1005                 /*
1006                  *      v6 mapped
1007                  */
1008
1009                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1010
1011                 if (!newsk)
1012                         return NULL;
1013
1014                 newtcp6sk = (struct tcp6_sock *)newsk;
1015                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1016
1017                 newinet = inet_sk(newsk);
1018                 newnp = inet6_sk(newsk);
1019                 newtp = tcp_sk(newsk);
1020
1021                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1022
1023                 newnp->saddr = newsk->sk_v6_rcv_saddr;
1024
1025                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1026                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1027 #ifdef CONFIG_TCP_MD5SIG
1028                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1029 #endif
1030
1031                 newnp->ipv6_ac_list = NULL;
1032                 newnp->ipv6_fl_list = NULL;
1033                 newnp->pktoptions  = NULL;
1034                 newnp->opt         = NULL;
1035                 newnp->mcast_oif   = tcp_v6_iif(skb);
1036                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1037                 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1038                 if (np->repflow)
1039                         newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1040
1041                 /*
1042                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1043                  * here, tcp_create_openreq_child now does this for us, see the comment in
1044                  * that function for the gory details. -acme
1045                  */
1046
1047                 /* It is tricky place. Until this moment IPv4 tcp
1048                    worked with IPv6 icsk.icsk_af_ops.
1049                    Sync it now.
1050                  */
1051                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1052
1053                 return newsk;
1054         }
1055
1056         ireq = inet_rsk(req);
1057
1058         if (sk_acceptq_is_full(sk))
1059                 goto out_overflow;
1060
1061         if (!dst) {
1062                 dst = inet6_csk_route_req(sk, &fl6, req);
1063                 if (!dst)
1064                         goto out;
1065         }
1066
1067         newsk = tcp_create_openreq_child(sk, req, skb);
1068         if (!newsk)
1069                 goto out_nonewsk;
1070
1071         /*
1072          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1073          * count here, tcp_create_openreq_child now does this for us, see the
1074          * comment in that function for the gory details. -acme
1075          */
1076
1077         newsk->sk_gso_type = SKB_GSO_TCPV6;
1078         __ip6_dst_store(newsk, dst, NULL, NULL);
1079         inet6_sk_rx_dst_set(newsk, skb);
1080
1081         newtcp6sk = (struct tcp6_sock *)newsk;
1082         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1083
1084         newtp = tcp_sk(newsk);
1085         newinet = inet_sk(newsk);
1086         newnp = inet6_sk(newsk);
1087
1088         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1089
1090         newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1091         newnp->saddr = ireq->ir_v6_loc_addr;
1092         newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1093         newsk->sk_bound_dev_if = ireq->ir_iif;
1094
1095         ip6_set_txhash(newsk);
1096
1097         /* Now IPv6 options...
1098
1099            First: no IPv4 options.
1100          */
1101         newinet->inet_opt = NULL;
1102         newnp->ipv6_ac_list = NULL;
1103         newnp->ipv6_fl_list = NULL;
1104
1105         /* Clone RX bits */
1106         newnp->rxopt.all = np->rxopt.all;
1107
1108         /* Clone pktoptions received with SYN */
1109         newnp->pktoptions = NULL;
1110         if (ireq->pktopts) {
1111                 newnp->pktoptions = skb_clone(ireq->pktopts,
1112                                               sk_gfp_atomic(sk, GFP_ATOMIC));
1113                 consume_skb(ireq->pktopts);
1114                 ireq->pktopts = NULL;
1115                 if (newnp->pktoptions)
1116                         skb_set_owner_r(newnp->pktoptions, newsk);
1117         }
1118         newnp->opt        = NULL;
1119         newnp->mcast_oif  = tcp_v6_iif(skb);
1120         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1121         newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1122         if (np->repflow)
1123                 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1124
1125         /* Clone native IPv6 options from listening socket (if any)
1126
1127            Yes, keeping reference count would be much more clever,
1128            but we make one more one thing there: reattach optmem
1129            to newsk.
1130          */
1131         if (np->opt)
1132                 newnp->opt = ipv6_dup_options(newsk, np->opt);
1133
1134         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1135         if (newnp->opt)
1136                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1137                                                      newnp->opt->opt_flen);
1138
1139         tcp_ca_openreq_child(newsk, dst);
1140
1141         tcp_sync_mss(newsk, dst_mtu(dst));
1142         newtp->advmss = dst_metric_advmss(dst);
1143         if (tcp_sk(sk)->rx_opt.user_mss &&
1144             tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1145                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1146
1147         tcp_initialize_rcv_mss(newsk);
1148
1149         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1150         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1151
1152 #ifdef CONFIG_TCP_MD5SIG
1153         /* Copy over the MD5 key from the original socket */
1154         key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1155         if (key) {
1156                 /* We're using one, so create a matching key
1157                  * on the newsk structure. If we fail to get
1158                  * memory, then we end up not copying the key
1159                  * across. Shucks.
1160                  */
1161                 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1162                                AF_INET6, key->key, key->keylen,
1163                                sk_gfp_atomic(sk, GFP_ATOMIC));
1164         }
1165 #endif
1166
1167         if (__inet_inherit_port(sk, newsk) < 0) {
1168                 inet_csk_prepare_forced_close(newsk);
1169                 tcp_done(newsk);
1170                 goto out;
1171         }
1172         __inet_hash(newsk, NULL);
1173
1174         return newsk;
1175
1176 out_overflow:
1177         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1178 out_nonewsk:
1179         dst_release(dst);
1180 out:
1181         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1182         return NULL;
1183 }
1184
1185 /* The socket must have it's spinlock held when we get
1186  * here.
1187  *
1188  * We have a potential double-lock case here, so even when
1189  * doing backlog processing we use the BH locking scheme.
1190  * This is because we cannot sleep with the original spinlock
1191  * held.
1192  */
1193 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1194 {
1195         struct ipv6_pinfo *np = inet6_sk(sk);
1196         struct tcp_sock *tp;
1197         struct sk_buff *opt_skb = NULL;
1198
1199         /* Imagine: socket is IPv6. IPv4 packet arrives,
1200            goes to IPv4 receive handler and backlogged.
1201            From backlog it always goes here. Kerboom...
1202            Fortunately, tcp_rcv_established and rcv_established
1203            handle them correctly, but it is not case with
1204            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1205          */
1206
1207         if (skb->protocol == htons(ETH_P_IP))
1208                 return tcp_v4_do_rcv(sk, skb);
1209
1210         if (sk_filter(sk, skb))
1211                 goto discard;
1212
1213         /*
1214          *      socket locking is here for SMP purposes as backlog rcv
1215          *      is currently called with bh processing disabled.
1216          */
1217
1218         /* Do Stevens' IPV6_PKTOPTIONS.
1219
1220            Yes, guys, it is the only place in our code, where we
1221            may make it not affecting IPv4.
1222            The rest of code is protocol independent,
1223            and I do not like idea to uglify IPv4.
1224
1225            Actually, all the idea behind IPV6_PKTOPTIONS
1226            looks not very well thought. For now we latch
1227            options, received in the last packet, enqueued
1228            by tcp. Feel free to propose better solution.
1229                                                --ANK (980728)
1230          */
1231         if (np->rxopt.all)
1232                 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1233
1234         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1235                 struct dst_entry *dst = sk->sk_rx_dst;
1236
1237                 sock_rps_save_rxhash(sk, skb);
1238                 sk_mark_napi_id(sk, skb);
1239                 if (dst) {
1240                         if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1241                             dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1242                                 dst_release(dst);
1243                                 sk->sk_rx_dst = NULL;
1244                         }
1245                 }
1246
1247                 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1248                 if (opt_skb)
1249                         goto ipv6_pktoptions;
1250                 return 0;
1251         }
1252
1253         if (tcp_checksum_complete(skb))
1254                 goto csum_err;
1255
1256         if (sk->sk_state == TCP_LISTEN) {
1257                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1258                 if (!nsk)
1259                         goto discard;
1260
1261                 /*
1262                  * Queue it on the new socket if the new socket is active,
1263                  * otherwise we just shortcircuit this and continue with
1264                  * the new socket..
1265                  */
1266                 if (nsk != sk) {
1267                         sock_rps_save_rxhash(nsk, skb);
1268                         sk_mark_napi_id(sk, skb);
1269                         if (tcp_child_process(sk, nsk, skb))
1270                                 goto reset;
1271                         if (opt_skb)
1272                                 __kfree_skb(opt_skb);
1273                         return 0;
1274                 }
1275         } else
1276                 sock_rps_save_rxhash(sk, skb);
1277
1278         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1279                 goto reset;
1280         if (opt_skb)
1281                 goto ipv6_pktoptions;
1282         return 0;
1283
1284 reset:
1285         tcp_v6_send_reset(sk, skb);
1286 discard:
1287         if (opt_skb)
1288                 __kfree_skb(opt_skb);
1289         kfree_skb(skb);
1290         return 0;
1291 csum_err:
1292         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1293         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1294         goto discard;
1295
1296
1297 ipv6_pktoptions:
1298         /* Do you ask, what is it?
1299
1300            1. skb was enqueued by tcp.
1301            2. skb is added to tail of read queue, rather than out of order.
1302            3. socket is not in passive state.
1303            4. Finally, it really contains options, which user wants to receive.
1304          */
1305         tp = tcp_sk(sk);
1306         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1307             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1308                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1309                         np->mcast_oif = tcp_v6_iif(opt_skb);
1310                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1311                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1312                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1313                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1314                 if (np->repflow)
1315                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1316                 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1317                         skb_set_owner_r(opt_skb, sk);
1318                         opt_skb = xchg(&np->pktoptions, opt_skb);
1319                 } else {
1320                         __kfree_skb(opt_skb);
1321                         opt_skb = xchg(&np->pktoptions, NULL);
1322                 }
1323         }
1324
1325         kfree_skb(opt_skb);
1326         return 0;
1327 }
1328
1329 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1330                            const struct tcphdr *th)
1331 {
1332         /* This is tricky: we move IP6CB at its correct location into
1333          * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1334          * _decode_session6() uses IP6CB().
1335          * barrier() makes sure compiler won't play aliasing games.
1336          */
1337         memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1338                 sizeof(struct inet6_skb_parm));
1339         barrier();
1340
1341         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1342         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1343                                     skb->len - th->doff*4);
1344         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1345         TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1346         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1347         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1348         TCP_SKB_CB(skb)->sacked = 0;
1349 }
1350
1351 static void tcp_v6_restore_cb(struct sk_buff *skb)
1352 {
1353         /* We need to move header back to the beginning if xfrm6_policy_check()
1354          * and tcp_v6_fill_cb() are going to be called again.
1355          */
1356         memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1357                 sizeof(struct inet6_skb_parm));
1358 }
1359
1360 static int tcp_v6_rcv(struct sk_buff *skb)
1361 {
1362         const struct tcphdr *th;
1363         const struct ipv6hdr *hdr;
1364         struct sock *sk;
1365         int ret;
1366         struct net *net = dev_net(skb->dev);
1367
1368         if (skb->pkt_type != PACKET_HOST)
1369                 goto discard_it;
1370
1371         /*
1372          *      Count it even if it's bad.
1373          */
1374         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1375
1376         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1377                 goto discard_it;
1378
1379         th = tcp_hdr(skb);
1380
1381         if (th->doff < sizeof(struct tcphdr)/4)
1382                 goto bad_packet;
1383         if (!pskb_may_pull(skb, th->doff*4))
1384                 goto discard_it;
1385
1386         if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1387                 goto csum_error;
1388
1389         th = tcp_hdr(skb);
1390         hdr = ipv6_hdr(skb);
1391
1392         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
1393                                 inet6_iif(skb));
1394         if (!sk)
1395                 goto no_tcp_socket;
1396
1397 process:
1398         if (sk->sk_state == TCP_TIME_WAIT)
1399                 goto do_time_wait;
1400
1401         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1402                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1403                 goto discard_and_relse;
1404         }
1405
1406         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1407                 goto discard_and_relse;
1408
1409         tcp_v6_fill_cb(skb, hdr, th);
1410
1411 #ifdef CONFIG_TCP_MD5SIG
1412         if (tcp_v6_inbound_md5_hash(sk, skb))
1413                 goto discard_and_relse;
1414 #endif
1415
1416         if (sk_filter(sk, skb))
1417                 goto discard_and_relse;
1418
1419         sk_incoming_cpu_update(sk);
1420         skb->dev = NULL;
1421
1422         bh_lock_sock_nested(sk);
1423         tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);
1424         ret = 0;
1425         if (!sock_owned_by_user(sk)) {
1426                 if (!tcp_prequeue(sk, skb))
1427                         ret = tcp_v6_do_rcv(sk, skb);
1428         } else if (unlikely(sk_add_backlog(sk, skb,
1429                                            sk->sk_rcvbuf + sk->sk_sndbuf))) {
1430                 bh_unlock_sock(sk);
1431                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1432                 goto discard_and_relse;
1433         }
1434         bh_unlock_sock(sk);
1435
1436         sock_put(sk);
1437         return ret ? -1 : 0;
1438
1439 no_tcp_socket:
1440         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1441                 goto discard_it;
1442
1443         tcp_v6_fill_cb(skb, hdr, th);
1444
1445         if (tcp_checksum_complete(skb)) {
1446 csum_error:
1447                 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1448 bad_packet:
1449                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1450         } else {
1451                 tcp_v6_send_reset(NULL, skb);
1452         }
1453
1454 discard_it:
1455         kfree_skb(skb);
1456         return 0;
1457
1458 discard_and_relse:
1459         sock_put(sk);
1460         goto discard_it;
1461
1462 do_time_wait:
1463         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1464                 inet_twsk_put(inet_twsk(sk));
1465                 goto discard_it;
1466         }
1467
1468         tcp_v6_fill_cb(skb, hdr, th);
1469
1470         if (tcp_checksum_complete(skb)) {
1471                 inet_twsk_put(inet_twsk(sk));
1472                 goto csum_error;
1473         }
1474
1475         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1476         case TCP_TW_SYN:
1477         {
1478                 struct sock *sk2;
1479
1480                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1481                                             &ipv6_hdr(skb)->saddr, th->source,
1482                                             &ipv6_hdr(skb)->daddr,
1483                                             ntohs(th->dest), tcp_v6_iif(skb));
1484                 if (sk2) {
1485                         struct inet_timewait_sock *tw = inet_twsk(sk);
1486                         inet_twsk_deschedule(tw);
1487                         inet_twsk_put(tw);
1488                         sk = sk2;
1489                         tcp_v6_restore_cb(skb);
1490                         goto process;
1491                 }
1492                 /* Fall through to ACK */
1493         }
1494         case TCP_TW_ACK:
1495                 tcp_v6_timewait_ack(sk, skb);
1496                 break;
1497         case TCP_TW_RST:
1498                 tcp_v6_restore_cb(skb);
1499                 goto no_tcp_socket;
1500         case TCP_TW_SUCCESS:
1501                 ;
1502         }
1503         goto discard_it;
1504 }
1505
1506 static void tcp_v6_early_demux(struct sk_buff *skb)
1507 {
1508         const struct ipv6hdr *hdr;
1509         const struct tcphdr *th;
1510         struct sock *sk;
1511
1512         if (skb->pkt_type != PACKET_HOST)
1513                 return;
1514
1515         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1516                 return;
1517
1518         hdr = ipv6_hdr(skb);
1519         th = tcp_hdr(skb);
1520
1521         if (th->doff < sizeof(struct tcphdr) / 4)
1522                 return;
1523
1524         /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1525         sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1526                                         &hdr->saddr, th->source,
1527                                         &hdr->daddr, ntohs(th->dest),
1528                                         inet6_iif(skb));
1529         if (sk) {
1530                 skb->sk = sk;
1531                 skb->destructor = sock_edemux;
1532                 if (sk_fullsock(sk)) {
1533                         struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1534
1535                         if (dst)
1536                                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1537                         if (dst &&
1538                             inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1539                                 skb_dst_set_noref(skb, dst);
1540                 }
1541         }
1542 }
1543
1544 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1545         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1546         .twsk_unique    = tcp_twsk_unique,
1547         .twsk_destructor = tcp_twsk_destructor,
1548 };
1549
1550 static const struct inet_connection_sock_af_ops ipv6_specific = {
1551         .queue_xmit        = inet6_csk_xmit,
1552         .send_check        = tcp_v6_send_check,
1553         .rebuild_header    = inet6_sk_rebuild_header,
1554         .sk_rx_dst_set     = inet6_sk_rx_dst_set,
1555         .conn_request      = tcp_v6_conn_request,
1556         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1557         .net_header_len    = sizeof(struct ipv6hdr),
1558         .net_frag_header_len = sizeof(struct frag_hdr),
1559         .setsockopt        = ipv6_setsockopt,
1560         .getsockopt        = ipv6_getsockopt,
1561         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1562         .sockaddr_len      = sizeof(struct sockaddr_in6),
1563         .bind_conflict     = inet6_csk_bind_conflict,
1564 #ifdef CONFIG_COMPAT
1565         .compat_setsockopt = compat_ipv6_setsockopt,
1566         .compat_getsockopt = compat_ipv6_getsockopt,
1567 #endif
1568         .mtu_reduced       = tcp_v6_mtu_reduced,
1569 };
1570
1571 #ifdef CONFIG_TCP_MD5SIG
1572 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1573         .md5_lookup     =       tcp_v6_md5_lookup,
1574         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1575         .md5_parse      =       tcp_v6_parse_md5_keys,
1576 };
1577 #endif
1578
1579 /*
1580  *      TCP over IPv4 via INET6 API
1581  */
1582 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1583         .queue_xmit        = ip_queue_xmit,
1584         .send_check        = tcp_v4_send_check,
1585         .rebuild_header    = inet_sk_rebuild_header,
1586         .sk_rx_dst_set     = inet_sk_rx_dst_set,
1587         .conn_request      = tcp_v6_conn_request,
1588         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1589         .net_header_len    = sizeof(struct iphdr),
1590         .setsockopt        = ipv6_setsockopt,
1591         .getsockopt        = ipv6_getsockopt,
1592         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1593         .sockaddr_len      = sizeof(struct sockaddr_in6),
1594         .bind_conflict     = inet6_csk_bind_conflict,
1595 #ifdef CONFIG_COMPAT
1596         .compat_setsockopt = compat_ipv6_setsockopt,
1597         .compat_getsockopt = compat_ipv6_getsockopt,
1598 #endif
1599         .mtu_reduced       = tcp_v4_mtu_reduced,
1600 };
1601
1602 #ifdef CONFIG_TCP_MD5SIG
1603 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1604         .md5_lookup     =       tcp_v4_md5_lookup,
1605         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1606         .md5_parse      =       tcp_v6_parse_md5_keys,
1607 };
1608 #endif
1609
1610 /* NOTE: A lot of things set to zero explicitly by call to
1611  *       sk_alloc() so need not be done here.
1612  */
1613 static int tcp_v6_init_sock(struct sock *sk)
1614 {
1615         struct inet_connection_sock *icsk = inet_csk(sk);
1616
1617         tcp_init_sock(sk);
1618
1619         icsk->icsk_af_ops = &ipv6_specific;
1620
1621 #ifdef CONFIG_TCP_MD5SIG
1622         tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1623 #endif
1624
1625         return 0;
1626 }
1627
1628 static void tcp_v6_destroy_sock(struct sock *sk)
1629 {
1630         tcp_v4_destroy_sock(sk);
1631         inet6_destroy_sock(sk);
1632 }
1633
1634 #ifdef CONFIG_PROC_FS
1635 /* Proc filesystem TCPv6 sock list dumping. */
1636 static void get_openreq6(struct seq_file *seq,
1637                          struct request_sock *req, int i, kuid_t uid)
1638 {
1639         long ttd = req->rsk_timer.expires - jiffies;
1640         const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1641         const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1642
1643         if (ttd < 0)
1644                 ttd = 0;
1645
1646         seq_printf(seq,
1647                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1648                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1649                    i,
1650                    src->s6_addr32[0], src->s6_addr32[1],
1651                    src->s6_addr32[2], src->s6_addr32[3],
1652                    inet_rsk(req)->ir_num,
1653                    dest->s6_addr32[0], dest->s6_addr32[1],
1654                    dest->s6_addr32[2], dest->s6_addr32[3],
1655                    ntohs(inet_rsk(req)->ir_rmt_port),
1656                    TCP_SYN_RECV,
1657                    0, 0, /* could print option size, but that is af dependent. */
1658                    1,   /* timers active (only the expire timer) */
1659                    jiffies_to_clock_t(ttd),
1660                    req->num_timeout,
1661                    from_kuid_munged(seq_user_ns(seq), uid),
1662                    0,  /* non standard timer */
1663                    0, /* open_requests have no inode */
1664                    0, req);
1665 }
1666
1667 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1668 {
1669         const struct in6_addr *dest, *src;
1670         __u16 destp, srcp;
1671         int timer_active;
1672         unsigned long timer_expires;
1673         const struct inet_sock *inet = inet_sk(sp);
1674         const struct tcp_sock *tp = tcp_sk(sp);
1675         const struct inet_connection_sock *icsk = inet_csk(sp);
1676         struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
1677
1678         dest  = &sp->sk_v6_daddr;
1679         src   = &sp->sk_v6_rcv_saddr;
1680         destp = ntohs(inet->inet_dport);
1681         srcp  = ntohs(inet->inet_sport);
1682
1683         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1684                 timer_active    = 1;
1685                 timer_expires   = icsk->icsk_timeout;
1686         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1687                 timer_active    = 4;
1688                 timer_expires   = icsk->icsk_timeout;
1689         } else if (timer_pending(&sp->sk_timer)) {
1690                 timer_active    = 2;
1691                 timer_expires   = sp->sk_timer.expires;
1692         } else {
1693                 timer_active    = 0;
1694                 timer_expires = jiffies;
1695         }
1696
1697         seq_printf(seq,
1698                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1699                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1700                    i,
1701                    src->s6_addr32[0], src->s6_addr32[1],
1702                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1703                    dest->s6_addr32[0], dest->s6_addr32[1],
1704                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1705                    sp->sk_state,
1706                    tp->write_seq-tp->snd_una,
1707                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1708                    timer_active,
1709                    jiffies_delta_to_clock_t(timer_expires - jiffies),
1710                    icsk->icsk_retransmits,
1711                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1712                    icsk->icsk_probes_out,
1713                    sock_i_ino(sp),
1714                    atomic_read(&sp->sk_refcnt), sp,
1715                    jiffies_to_clock_t(icsk->icsk_rto),
1716                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1717                    (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1718                    tp->snd_cwnd,
1719                    sp->sk_state == TCP_LISTEN ?
1720                         (fastopenq ? fastopenq->max_qlen : 0) :
1721                         (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1722                    );
1723 }
1724
1725 static void get_timewait6_sock(struct seq_file *seq,
1726                                struct inet_timewait_sock *tw, int i)
1727 {
1728         long delta = tw->tw_timer.expires - jiffies;
1729         const struct in6_addr *dest, *src;
1730         __u16 destp, srcp;
1731
1732         dest = &tw->tw_v6_daddr;
1733         src  = &tw->tw_v6_rcv_saddr;
1734         destp = ntohs(tw->tw_dport);
1735         srcp  = ntohs(tw->tw_sport);
1736
1737         seq_printf(seq,
1738                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1739                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1740                    i,
1741                    src->s6_addr32[0], src->s6_addr32[1],
1742                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1743                    dest->s6_addr32[0], dest->s6_addr32[1],
1744                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1745                    tw->tw_substate, 0, 0,
1746                    3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1747                    atomic_read(&tw->tw_refcnt), tw);
1748 }
1749
1750 static int tcp6_seq_show(struct seq_file *seq, void *v)
1751 {
1752         struct tcp_iter_state *st;
1753         struct sock *sk = v;
1754
1755         if (v == SEQ_START_TOKEN) {
1756                 seq_puts(seq,
1757                          "  sl  "
1758                          "local_address                         "
1759                          "remote_address                        "
1760                          "st tx_queue rx_queue tr tm->when retrnsmt"
1761                          "   uid  timeout inode\n");
1762                 goto out;
1763         }
1764         st = seq->private;
1765
1766         switch (st->state) {
1767         case TCP_SEQ_STATE_LISTENING:
1768         case TCP_SEQ_STATE_ESTABLISHED:
1769                 if (sk->sk_state == TCP_TIME_WAIT)
1770                         get_timewait6_sock(seq, v, st->num);
1771                 else
1772                         get_tcp6_sock(seq, v, st->num);
1773                 break;
1774         case TCP_SEQ_STATE_OPENREQ:
1775                 get_openreq6(seq, v, st->num, st->uid);
1776                 break;
1777         }
1778 out:
1779         return 0;
1780 }
1781
1782 static const struct file_operations tcp6_afinfo_seq_fops = {
1783         .owner   = THIS_MODULE,
1784         .open    = tcp_seq_open,
1785         .read    = seq_read,
1786         .llseek  = seq_lseek,
1787         .release = seq_release_net
1788 };
1789
1790 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1791         .name           = "tcp6",
1792         .family         = AF_INET6,
1793         .seq_fops       = &tcp6_afinfo_seq_fops,
1794         .seq_ops        = {
1795                 .show           = tcp6_seq_show,
1796         },
1797 };
1798
1799 int __net_init tcp6_proc_init(struct net *net)
1800 {
1801         return tcp_proc_register(net, &tcp6_seq_afinfo);
1802 }
1803
1804 void tcp6_proc_exit(struct net *net)
1805 {
1806         tcp_proc_unregister(net, &tcp6_seq_afinfo);
1807 }
1808 #endif
1809
1810 static void tcp_v6_clear_sk(struct sock *sk, int size)
1811 {
1812         struct inet_sock *inet = inet_sk(sk);
1813
1814         /* we do not want to clear pinet6 field, because of RCU lookups */
1815         sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1816
1817         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1818         memset(&inet->pinet6 + 1, 0, size);
1819 }
1820
1821 struct proto tcpv6_prot = {
1822         .name                   = "TCPv6",
1823         .owner                  = THIS_MODULE,
1824         .close                  = tcp_close,
1825         .connect                = tcp_v6_connect,
1826         .disconnect             = tcp_disconnect,
1827         .accept                 = inet_csk_accept,
1828         .ioctl                  = tcp_ioctl,
1829         .init                   = tcp_v6_init_sock,
1830         .destroy                = tcp_v6_destroy_sock,
1831         .shutdown               = tcp_shutdown,
1832         .setsockopt             = tcp_setsockopt,
1833         .getsockopt             = tcp_getsockopt,
1834         .recvmsg                = tcp_recvmsg,
1835         .sendmsg                = tcp_sendmsg,
1836         .sendpage               = tcp_sendpage,
1837         .backlog_rcv            = tcp_v6_do_rcv,
1838         .release_cb             = tcp_release_cb,
1839         .hash                   = inet_hash,
1840         .unhash                 = inet_unhash,
1841         .get_port               = inet_csk_get_port,
1842         .enter_memory_pressure  = tcp_enter_memory_pressure,
1843         .stream_memory_free     = tcp_stream_memory_free,
1844         .sockets_allocated      = &tcp_sockets_allocated,
1845         .memory_allocated       = &tcp_memory_allocated,
1846         .memory_pressure        = &tcp_memory_pressure,
1847         .orphan_count           = &tcp_orphan_count,
1848         .sysctl_mem             = sysctl_tcp_mem,
1849         .sysctl_wmem            = sysctl_tcp_wmem,
1850         .sysctl_rmem            = sysctl_tcp_rmem,
1851         .max_header             = MAX_TCP_HEADER,
1852         .obj_size               = sizeof(struct tcp6_sock),
1853         .slab_flags             = SLAB_DESTROY_BY_RCU,
1854         .twsk_prot              = &tcp6_timewait_sock_ops,
1855         .rsk_prot               = &tcp6_request_sock_ops,
1856         .h.hashinfo             = &tcp_hashinfo,
1857         .no_autobind            = true,
1858 #ifdef CONFIG_COMPAT
1859         .compat_setsockopt      = compat_tcp_setsockopt,
1860         .compat_getsockopt      = compat_tcp_getsockopt,
1861 #endif
1862 #ifdef CONFIG_MEMCG_KMEM
1863         .proto_cgroup           = tcp_proto_cgroup,
1864 #endif
1865         .clear_sk               = tcp_v6_clear_sk,
1866 };
1867
1868 static const struct inet6_protocol tcpv6_protocol = {
1869         .early_demux    =       tcp_v6_early_demux,
1870         .handler        =       tcp_v6_rcv,
1871         .err_handler    =       tcp_v6_err,
1872         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1873 };
1874
1875 static struct inet_protosw tcpv6_protosw = {
1876         .type           =       SOCK_STREAM,
1877         .protocol       =       IPPROTO_TCP,
1878         .prot           =       &tcpv6_prot,
1879         .ops            =       &inet6_stream_ops,
1880         .flags          =       INET_PROTOSW_PERMANENT |
1881                                 INET_PROTOSW_ICSK,
1882 };
1883
1884 static int __net_init tcpv6_net_init(struct net *net)
1885 {
1886         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1887                                     SOCK_RAW, IPPROTO_TCP, net);
1888 }
1889
1890 static void __net_exit tcpv6_net_exit(struct net *net)
1891 {
1892         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1893 }
1894
1895 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1896 {
1897         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1898 }
1899
1900 static struct pernet_operations tcpv6_net_ops = {
1901         .init       = tcpv6_net_init,
1902         .exit       = tcpv6_net_exit,
1903         .exit_batch = tcpv6_net_exit_batch,
1904 };
1905
1906 int __init tcpv6_init(void)
1907 {
1908         int ret;
1909
1910         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1911         if (ret)
1912                 goto out;
1913
1914         /* register inet6 protocol */
1915         ret = inet6_register_protosw(&tcpv6_protosw);
1916         if (ret)
1917                 goto out_tcpv6_protocol;
1918
1919         ret = register_pernet_subsys(&tcpv6_net_ops);
1920         if (ret)
1921                 goto out_tcpv6_protosw;
1922 out:
1923         return ret;
1924
1925 out_tcpv6_protosw:
1926         inet6_unregister_protosw(&tcpv6_protosw);
1927 out_tcpv6_protocol:
1928         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1929         goto out;
1930 }
1931
1932 void tcpv6_exit(void)
1933 {
1934         unregister_pernet_subsys(&tcpv6_net_ops);
1935         inet6_unregister_protosw(&tcpv6_protosw);
1936         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1937 }