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  *      $Id: tcp_ipv6.c,v 1.144 2002/02/01 22:01:04 davem Exp $
   9  *
  10  *      Based on:
  11  *      linux/net/ipv4/tcp.c
  12  *      linux/net/ipv4/tcp_input.c
  13  *      linux/net/ipv4/tcp_output.c
  14  *
  15  *      Fixes:
  16  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  17  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  18  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  19  *                                      a single port at the same time.
  20  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  21  *
  22  *      This program is free software; you can redistribute it and/or
  23  *      modify it under the terms of the GNU General Public License
  24  *      as published by the Free Software Foundation; either version
  25  *      2 of the License, or (at your option) any later version.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/types.h>
  31 #include <linux/socket.h>
  32 #include <linux/sockios.h>
  33 #include <linux/net.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/in.h>
  36 #include <linux/in6.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/init.h>
  39 #include <linux/jhash.h>
  40 #include <linux/ipsec.h>
  41 #include <linux/times.h>
  42
  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/addrconf.h>
  60 #include <net/snmp.h>
  61 #include <net/dsfield.h>
  62 #include <net/timewait_sock.h>
  63
  64 #include <asm/uaccess.h>
  65
  66 #include <linux/proc_fs.h>
  67 #include <linux/seq_file.h>
  68
  69 #include <linux/crypto.h>
  70 #include <linux/scatterlist.h>
  71
  72 /* Socket used for sending RSTs and ACKs */
  73 static struct socket *tcp6_socket;
  74
  75 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  76 static void     tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req);
  77 static void     tcp_v6_send_check(struct sock *sk, int len,
  78                                   struct sk_buff *skb);
  79
  80 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  81
  82 static struct inet_connection_sock_af_ops ipv6_mapped;
  83 static struct inet_connection_sock_af_ops ipv6_specific;
  84 #ifdef CONFIG_TCP_MD5SIG
  85 static struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  86 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  87 #endif
  88
  89 static int tcp_v6_get_port(struct sock *sk, unsigned short snum)
  90 {
  91         return inet_csk_get_port(&tcp_hashinfo, sk, snum,
  92                                  inet6_csk_bind_conflict);
  93 }
  94
  95 static void tcp_v6_hash(struct sock *sk)
  96 {
  97         if (sk->sk_state != TCP_CLOSE) {
  98                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
  99                         tcp_prot.hash(sk);
 100                         return;
 101                 }
 102                 local_bh_disable();
 103                 __inet6_hash(&tcp_hashinfo, sk);
 104                 local_bh_enable();
 105         }
 106 }
 107
 108 static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len,
 109                                    struct in6_addr *saddr,
 110                                    struct in6_addr *daddr,
 111                                    __wsum base)
 112 {
 113         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
 114 }
 115
 116 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
 117 {
 118         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 119                                             ipv6_hdr(skb)->saddr.s6_addr32,
 120                                             tcp_hdr(skb)->dest,
 121                                             tcp_hdr(skb)->source);
 122 }
 123
 124 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 125                           int addr_len)
 126 {
 127         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 128         struct inet_sock *inet = inet_sk(sk);
 129         struct inet_connection_sock *icsk = inet_csk(sk);
 130         struct ipv6_pinfo *np = inet6_sk(sk);
 131         struct tcp_sock *tp = tcp_sk(sk);
 132         struct in6_addr *saddr = NULL, *final_p = NULL, final;
 133         struct flowi fl;
 134         struct dst_entry *dst;
 135         int addr_type;
 136         int err;
 137
 138         if (addr_len < SIN6_LEN_RFC2133)
 139                 return -EINVAL;
 140
 141         if (usin->sin6_family != AF_INET6)
 142                 return(-EAFNOSUPPORT);
 143
 144         memset(&fl, 0, sizeof(fl));
 145
 146         if (np->sndflow) {
 147                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 148                 IP6_ECN_flow_init(fl.fl6_flowlabel);
 149                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
 150                         struct ip6_flowlabel *flowlabel;
 151                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
 152                         if (flowlabel == NULL)
 153                                 return -EINVAL;
 154                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
 155                         fl6_sock_release(flowlabel);
 156                 }
 157         }
 158
 159         /*
 160          *      connect() to INADDR_ANY means loopback (BSD'ism).
 161          */
 162
 163         if(ipv6_addr_any(&usin->sin6_addr))
 164                 usin->sin6_addr.s6_addr[15] = 0x1;
 165
 166         addr_type = ipv6_addr_type(&usin->sin6_addr);
 167
 168         if(addr_type & IPV6_ADDR_MULTICAST)
 169                 return -ENETUNREACH;
 170
 171         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 172                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 173                     usin->sin6_scope_id) {
 174                         /* If interface is set while binding, indices
 175                          * must coincide.
 176                          */
 177                         if (sk->sk_bound_dev_if &&
 178                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 179                                 return -EINVAL;
 180
 181                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 182                 }
 183
 184                 /* Connect to link-local address requires an interface */
 185                 if (!sk->sk_bound_dev_if)
 186                         return -EINVAL;
 187         }
 188
 189         if (tp->rx_opt.ts_recent_stamp &&
 190             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 191                 tp->rx_opt.ts_recent = 0;
 192                 tp->rx_opt.ts_recent_stamp = 0;
 193                 tp->write_seq = 0;
 194         }
 195
 196         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
 197         np->flow_label = fl.fl6_flowlabel;
 198
 199         /*
 200          *      TCP over IPv4
 201          */
 202
 203         if (addr_type == IPV6_ADDR_MAPPED) {
 204                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 205                 struct sockaddr_in sin;
 206
 207                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 208
 209                 if (__ipv6_only_sock(sk))
 210                         return -ENETUNREACH;
 211
 212                 sin.sin_family = AF_INET;
 213                 sin.sin_port = usin->sin6_port;
 214                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 215
 216                 icsk->icsk_af_ops = &ipv6_mapped;
 217                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 218 #ifdef CONFIG_TCP_MD5SIG
 219                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 220 #endif
 221
 222                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 223
 224                 if (err) {
 225                         icsk->icsk_ext_hdr_len = exthdrlen;
 226                         icsk->icsk_af_ops = &ipv6_specific;
 227                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 228 #ifdef CONFIG_TCP_MD5SIG
 229                         tp->af_specific = &tcp_sock_ipv6_specific;
 230 #endif
 231                         goto failure;
 232                 } else {
 233                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
 234                                       inet->saddr);
 235                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
 236                                       inet->rcv_saddr);
 237                 }
 238
 239                 return err;
 240         }
 241
 242         if (!ipv6_addr_any(&np->rcv_saddr))
 243                 saddr = &np->rcv_saddr;
 244
 245         fl.proto = IPPROTO_TCP;
 246         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 247         ipv6_addr_copy(&fl.fl6_src,
 248                        (saddr ? saddr : &np->saddr));
 249         fl.oif = sk->sk_bound_dev_if;
 250         fl.fl_ip_dport = usin->sin6_port;
 251         fl.fl_ip_sport = inet->sport;
 252
 253         if (np->opt && np->opt->srcrt) {
 254                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 255                 ipv6_addr_copy(&final, &fl.fl6_dst);
 256                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 257                 final_p = &final;
 258         }
 259
 260         security_sk_classify_flow(sk, &fl);
 261
 262         err = ip6_dst_lookup(sk, &dst, &fl);
 263         if (err)
 264                 goto failure;
 265         if (final_p)
 266                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 267
 268         if ((err = xfrm_lookup(&dst, &fl, sk, 1)) < 0)
 269                 goto failure;
 270
 271         if (saddr == NULL) {
 272                 saddr = &fl.fl6_src;
 273                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 274         }
 275
 276         /* set the source address */
 277         ipv6_addr_copy(&np->saddr, saddr);
 278         inet->rcv_saddr = LOOPBACK4_IPV6;
 279
 280         sk->sk_gso_type = SKB_GSO_TCPV6;
 281         __ip6_dst_store(sk, dst, NULL, NULL);
 282
 283         icsk->icsk_ext_hdr_len = 0;
 284         if (np->opt)
 285                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 286                                           np->opt->opt_nflen);
 287
 288         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 289
 290         inet->dport = usin->sin6_port;
 291
 292         tcp_set_state(sk, TCP_SYN_SENT);
 293         err = inet6_hash_connect(&tcp_death_row, sk);
 294         if (err)
 295                 goto late_failure;
 296
 297         if (!tp->write_seq)
 298                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 299                                                              np->daddr.s6_addr32,
 300                                                              inet->sport,
 301                                                              inet->dport);
 302
 303         err = tcp_connect(sk);
 304         if (err)
 305                 goto late_failure;
 306
 307         return 0;
 308
 309 late_failure:
 310         tcp_set_state(sk, TCP_CLOSE);
 311         __sk_dst_reset(sk);
 312 failure:
 313         inet->dport = 0;
 314         sk->sk_route_caps = 0;
 315         return err;
 316 }
 317
 318 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 319                 int type, int code, int offset, __be32 info)
 320 {
 321         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
 322         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 323         struct ipv6_pinfo *np;
 324         struct sock *sk;
 325         int err;
 326         struct tcp_sock *tp;
 327         __u32 seq;
 328
 329         sk = inet6_lookup(&tcp_hashinfo, &hdr->daddr, th->dest, &hdr->saddr,
 330                           th->source, skb->dev->ifindex);
 331
 332         if (sk == NULL) {
 333                 ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 334                 return;
 335         }
 336
 337         if (sk->sk_state == TCP_TIME_WAIT) {
 338                 inet_twsk_put(inet_twsk(sk));
 339                 return;
 340         }
 341
 342         bh_lock_sock(sk);
 343         if (sock_owned_by_user(sk))
 344                 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
 345
 346         if (sk->sk_state == TCP_CLOSE)
 347                 goto out;
 348
 349         tp = tcp_sk(sk);
 350         seq = ntohl(th->seq);
 351         if (sk->sk_state != TCP_LISTEN &&
 352             !between(seq, tp->snd_una, tp->snd_nxt)) {
 353                 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 354                 goto out;
 355         }
 356
 357         np = inet6_sk(sk);
 358
 359         if (type == ICMPV6_PKT_TOOBIG) {
 360                 struct dst_entry *dst = NULL;
 361
 362                 if (sock_owned_by_user(sk))
 363                         goto out;
 364                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 365                         goto out;
 366
 367                 /* icmp should have updated the destination cache entry */
 368                 dst = __sk_dst_check(sk, np->dst_cookie);
 369
 370                 if (dst == NULL) {
 371                         struct inet_sock *inet = inet_sk(sk);
 372                         struct flowi fl;
 373
 374                         /* BUGGG_FUTURE: Again, it is not clear how
 375                            to handle rthdr case. Ignore this complexity
 376                            for now.
 377                          */
 378                         memset(&fl, 0, sizeof(fl));
 379                         fl.proto = IPPROTO_TCP;
 380                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 381                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 382                         fl.oif = sk->sk_bound_dev_if;
 383                         fl.fl_ip_dport = inet->dport;
 384                         fl.fl_ip_sport = inet->sport;
 385                         security_skb_classify_flow(skb, &fl);
 386
 387                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
 388                                 sk->sk_err_soft = -err;
 389                                 goto out;
 390                         }
 391
 392                         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 393                                 sk->sk_err_soft = -err;
 394                                 goto out;
 395                         }
 396
 397                 } else
 398                         dst_hold(dst);
 399
 400                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 401                         tcp_sync_mss(sk, dst_mtu(dst));
 402                         tcp_simple_retransmit(sk);
 403                 } /* else let the usual retransmit timer handle it */
 404                 dst_release(dst);
 405                 goto out;
 406         }
 407
 408         icmpv6_err_convert(type, code, &err);
 409
 410         /* Might be for an request_sock */
 411         switch (sk->sk_state) {
 412                 struct request_sock *req, **prev;
 413         case TCP_LISTEN:
 414                 if (sock_owned_by_user(sk))
 415                         goto out;
 416
 417                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 418                                            &hdr->saddr, inet6_iif(skb));
 419                 if (!req)
 420                         goto out;
 421
 422                 /* ICMPs are not backlogged, hence we cannot get
 423                  * an established socket here.
 424                  */
 425                 BUG_TRAP(req->sk == NULL);
 426
 427                 if (seq != tcp_rsk(req)->snt_isn) {
 428                         NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 429                         goto out;
 430                 }
 431
 432                 inet_csk_reqsk_queue_drop(sk, req, prev);
 433                 goto out;
 434
 435         case TCP_SYN_SENT:
 436         case TCP_SYN_RECV:  /* Cannot happen.
 437                                It can, it SYNs are crossed. --ANK */
 438                 if (!sock_owned_by_user(sk)) {
 439                         sk->sk_err = err;
 440                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 441
 442                         tcp_done(sk);
 443                 } else
 444                         sk->sk_err_soft = err;
 445                 goto out;
 446         }
 447
 448         if (!sock_owned_by_user(sk) && np->recverr) {
 449                 sk->sk_err = err;
 450                 sk->sk_error_report(sk);
 451         } else
 452                 sk->sk_err_soft = err;
 453
 454 out:
 455         bh_unlock_sock(sk);
 456         sock_put(sk);
 457 }
 458
 459
 460 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
 461                               struct dst_entry *dst)
 462 {
 463         struct inet6_request_sock *treq = inet6_rsk(req);
 464         struct ipv6_pinfo *np = inet6_sk(sk);
 465         struct sk_buff * skb;
 466         struct ipv6_txoptions *opt = NULL;
 467         struct in6_addr * final_p = NULL, final;
 468         struct flowi fl;
 469         int err = -1;
 470
 471         memset(&fl, 0, sizeof(fl));
 472         fl.proto = IPPROTO_TCP;
 473         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 474         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
 475         fl.fl6_flowlabel = 0;
 476         fl.oif = treq->iif;
 477         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
 478         fl.fl_ip_sport = inet_sk(sk)->sport;
 479         security_req_classify_flow(req, &fl);
 480
 481         if (dst == NULL) {
 482                 opt = np->opt;
 483                 if (opt == NULL &&
 484                     np->rxopt.bits.osrcrt == 2 &&
 485                     treq->pktopts) {
 486                         struct sk_buff *pktopts = treq->pktopts;
 487                         struct inet6_skb_parm *rxopt = IP6CB(pktopts);
 488                         if (rxopt->srcrt)
 489                                 opt = ipv6_invert_rthdr(sk,
 490                           (struct ipv6_rt_hdr *)(skb_network_header(pktopts) +
 491                                                  rxopt->srcrt));
 492                 }
 493
 494                 if (opt && opt->srcrt) {
 495                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
 496                         ipv6_addr_copy(&final, &fl.fl6_dst);
 497                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 498                         final_p = &final;
 499                 }
 500
 501                 err = ip6_dst_lookup(sk, &dst, &fl);
 502                 if (err)
 503                         goto done;
 504                 if (final_p)
 505                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 506                 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 507                         goto done;
 508         }
 509
 510         skb = tcp_make_synack(sk, dst, req);
 511         if (skb) {
 512                 struct tcphdr *th = tcp_hdr(skb);
 513
 514                 th->check = tcp_v6_check(th, skb->len,
 515                                          &treq->loc_addr, &treq->rmt_addr,
 516                                          csum_partial((char *)th, skb->len, skb->csum));
 517
 518                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 519                 err = ip6_xmit(sk, skb, &fl, opt, 0);
 520                 err = net_xmit_eval(err);
 521         }
 522
 523 done:
 524         if (opt && opt != np->opt)
 525                 sock_kfree_s(sk, opt, opt->tot_len);
 526         dst_release(dst);
 527         return err;
 528 }
 529
 530 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 531 {
 532         if (inet6_rsk(req)->pktopts)
 533                 kfree_skb(inet6_rsk(req)->pktopts);
 534 }
 535
 536 #ifdef CONFIG_TCP_MD5SIG
 537 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 538                                                    struct in6_addr *addr)
 539 {
 540         struct tcp_sock *tp = tcp_sk(sk);
 541         int i;
 542
 543         BUG_ON(tp == NULL);
 544
 545         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 546                 return NULL;
 547
 548         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 549                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, addr) == 0)
 550                         return (struct tcp_md5sig_key *)&tp->md5sig_info->keys6[i];
 551         }
 552         return NULL;
 553 }
 554
 555 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 556                                                 struct sock *addr_sk)
 557 {
 558         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 559 }
 560
 561 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 562                                                       struct request_sock *req)
 563 {
 564         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 565 }
 566
 567 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
 568                              char *newkey, u8 newkeylen)
 569 {
 570         /* Add key to the list */
 571         struct tcp6_md5sig_key *key;
 572         struct tcp_sock *tp = tcp_sk(sk);
 573         struct tcp6_md5sig_key *keys;
 574
 575         key = (struct tcp6_md5sig_key*) tcp_v6_md5_do_lookup(sk, peer);
 576         if (key) {
 577                 /* modify existing entry - just update that one */
 578                 kfree(key->key);
 579                 key->key = newkey;
 580                 key->keylen = newkeylen;
 581         } else {
 582                 /* reallocate new list if current one is full. */
 583                 if (!tp->md5sig_info) {
 584                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 585                         if (!tp->md5sig_info) {
 586                                 kfree(newkey);
 587                                 return -ENOMEM;
 588                         }
 589                 }
 590                 tcp_alloc_md5sig_pool();
 591                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 592                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 593                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 594
 595                         if (!keys) {
 596                                 tcp_free_md5sig_pool();
 597                                 kfree(newkey);
 598                                 return -ENOMEM;
 599                         }
 600
 601                         if (tp->md5sig_info->entries6)
 602                                 memmove(keys, tp->md5sig_info->keys6,
 603                                         (sizeof (tp->md5sig_info->keys6[0]) *
 604                                          tp->md5sig_info->entries6));
 605
 606                         kfree(tp->md5sig_info->keys6);
 607                         tp->md5sig_info->keys6 = keys;
 608                         tp->md5sig_info->alloced6++;
 609                 }
 610
 611                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 612                                peer);
 613                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].key = newkey;
 614                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].keylen = newkeylen;
 615
 616                 tp->md5sig_info->entries6++;
 617         }
 618         return 0;
 619 }
 620
 621 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 622                                u8 *newkey, __u8 newkeylen)
 623 {
 624         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 625                                  newkey, newkeylen);
 626 }
 627
 628 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 629 {
 630         struct tcp_sock *tp = tcp_sk(sk);
 631         int i;
 632
 633         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 634                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, peer) == 0) {
 635                         /* Free the key */
 636                         kfree(tp->md5sig_info->keys6[i].key);
 637                         tp->md5sig_info->entries6--;
 638
 639                         if (tp->md5sig_info->entries6 == 0) {
 640                                 kfree(tp->md5sig_info->keys6);
 641                                 tp->md5sig_info->keys6 = NULL;
 642
 643                                 tcp_free_md5sig_pool();
 644
 645                                 return 0;
 646                         } else {
 647                                 /* shrink the database */
 648                                 if (tp->md5sig_info->entries6 != i)
 649                                         memmove(&tp->md5sig_info->keys6[i],
 650                                                 &tp->md5sig_info->keys6[i+1],
 651                                                 (tp->md5sig_info->entries6 - i)
 652                                                 * sizeof (tp->md5sig_info->keys6[0]));
 653                         }
 654                 }
 655         }
 656         return -ENOENT;
 657 }
 658
 659 static void tcp_v6_clear_md5_list (struct sock *sk)
 660 {
 661         struct tcp_sock *tp = tcp_sk(sk);
 662         int i;
 663
 664         if (tp->md5sig_info->entries6) {
 665                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 666                         kfree(tp->md5sig_info->keys6[i].key);
 667                 tp->md5sig_info->entries6 = 0;
 668                 tcp_free_md5sig_pool();
 669         }
 670
 671         kfree(tp->md5sig_info->keys6);
 672         tp->md5sig_info->keys6 = NULL;
 673         tp->md5sig_info->alloced6 = 0;
 674
 675         if (tp->md5sig_info->entries4) {
 676                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 677                         kfree(tp->md5sig_info->keys4[i].key);
 678                 tp->md5sig_info->entries4 = 0;
 679                 tcp_free_md5sig_pool();
 680         }
 681
 682         kfree(tp->md5sig_info->keys4);
 683         tp->md5sig_info->keys4 = NULL;
 684         tp->md5sig_info->alloced4 = 0;
 685 }
 686
 687 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 688                                   int optlen)
 689 {
 690         struct tcp_md5sig cmd;
 691         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 692         u8 *newkey;
 693
 694         if (optlen < sizeof(cmd))
 695                 return -EINVAL;
 696
 697         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 698                 return -EFAULT;
 699
 700         if (sin6->sin6_family != AF_INET6)
 701                 return -EINVAL;
 702
 703         if (!cmd.tcpm_keylen) {
 704                 if (!tcp_sk(sk)->md5sig_info)
 705                         return -ENOENT;
 706                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 707                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 708                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 709         }
 710
 711         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 712                 return -EINVAL;
 713
 714         if (!tcp_sk(sk)->md5sig_info) {
 715                 struct tcp_sock *tp = tcp_sk(sk);
 716                 struct tcp_md5sig_info *p;
 717
 718                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 719                 if (!p)
 720                         return -ENOMEM;
 721
 722                 tp->md5sig_info = p;
 723         }
 724
 725         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 726         if (!newkey)
 727                 return -ENOMEM;
 728         if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED) {
 729                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 730                                          newkey, cmd.tcpm_keylen);
 731         }
 732         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 733 }
 734
 735 static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 736                                    struct in6_addr *saddr,
 737                                    struct in6_addr *daddr,
 738                                    struct tcphdr *th, int protocol,
 739                                    int tcplen)
 740 {
 741         struct scatterlist sg[4];
 742         __u16 data_len;
 743         int block = 0;
 744         __sum16 cksum;
 745         struct tcp_md5sig_pool *hp;
 746         struct tcp6_pseudohdr *bp;
 747         struct hash_desc *desc;
 748         int err;
 749         unsigned int nbytes = 0;
 750
 751         hp = tcp_get_md5sig_pool();
 752         if (!hp) {
 753                 printk(KERN_WARNING "%s(): hash pool not found...\n", __FUNCTION__);
 754                 goto clear_hash_noput;
 755         }
 756         bp = &hp->md5_blk.ip6;
 757         desc = &hp->md5_desc;
 758
 759         /* 1. TCP pseudo-header (RFC2460) */
 760         ipv6_addr_copy(&bp->saddr, saddr);
 761         ipv6_addr_copy(&bp->daddr, daddr);
 762         bp->len = htonl(tcplen);
 763         bp->protocol = htonl(protocol);
 764
 765         sg_set_buf(&sg[block++], bp, sizeof(*bp));
 766         nbytes += sizeof(*bp);
 767
 768         /* 2. TCP header, excluding options */
 769         cksum = th->check;
 770         th->check = 0;
 771         sg_set_buf(&sg[block++], th, sizeof(*th));
 772         nbytes += sizeof(*th);
 773
 774         /* 3. TCP segment data (if any) */
 775         data_len = tcplen - (th->doff << 2);
 776         if (data_len > 0) {
 777                 u8 *data = (u8 *)th + (th->doff << 2);
 778                 sg_set_buf(&sg[block++], data, data_len);
 779                 nbytes += data_len;
 780         }
 781
 782         /* 4. shared key */
 783         sg_set_buf(&sg[block++], key->key, key->keylen);
 784         nbytes += key->keylen;
 785
 786         /* Now store the hash into the packet */
 787         err = crypto_hash_init(desc);
 788         if (err) {
 789                 printk(KERN_WARNING "%s(): hash_init failed\n", __FUNCTION__);
 790                 goto clear_hash;
 791         }
 792         err = crypto_hash_update(desc, sg, nbytes);
 793         if (err) {
 794                 printk(KERN_WARNING "%s(): hash_update failed\n", __FUNCTION__);
 795                 goto clear_hash;
 796         }
 797         err = crypto_hash_final(desc, md5_hash);
 798         if (err) {
 799                 printk(KERN_WARNING "%s(): hash_final failed\n", __FUNCTION__);
 800                 goto clear_hash;
 801         }
 802
 803         /* Reset header, and free up the crypto */
 804         tcp_put_md5sig_pool();
 805         th->check = cksum;
 806 out:
 807         return 0;
 808 clear_hash:
 809         tcp_put_md5sig_pool();
 810 clear_hash_noput:
 811         memset(md5_hash, 0, 16);
 812         goto out;
 813 }
 814
 815 static int tcp_v6_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 816                                 struct sock *sk,
 817                                 struct dst_entry *dst,
 818                                 struct request_sock *req,
 819                                 struct tcphdr *th, int protocol,
 820                                 int tcplen)
 821 {
 822         struct in6_addr *saddr, *daddr;
 823
 824         if (sk) {
 825                 saddr = &inet6_sk(sk)->saddr;
 826                 daddr = &inet6_sk(sk)->daddr;
 827         } else {
 828                 saddr = &inet6_rsk(req)->loc_addr;
 829                 daddr = &inet6_rsk(req)->rmt_addr;
 830         }
 831         return tcp_v6_do_calc_md5_hash(md5_hash, key,
 832                                        saddr, daddr,
 833                                        th, protocol, tcplen);
 834 }
 835
 836 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 837 {
 838         __u8 *hash_location = NULL;
 839         struct tcp_md5sig_key *hash_expected;
 840         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 841         struct tcphdr *th = tcp_hdr(skb);
 842         int length = (th->doff << 2) - sizeof (*th);
 843         int genhash;
 844         u8 *ptr;
 845         u8 newhash[16];
 846
 847         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 848
 849         /* If the TCP option is too short, we can short cut */
 850         if (length < TCPOLEN_MD5SIG)
 851                 return hash_expected ? 1 : 0;
 852
 853         /* parse options */
 854         ptr = (u8*)(th + 1);
 855         while (length > 0) {
 856                 int opcode = *ptr++;
 857                 int opsize;
 858
 859                 switch(opcode) {
 860                 case TCPOPT_EOL:
 861                         goto done_opts;
 862                 case TCPOPT_NOP:
 863                         length--;
 864                         continue;
 865                 default:
 866                         opsize = *ptr++;
 867                         if (opsize < 2 || opsize > length)
 868                                 goto done_opts;
 869                         if (opcode == TCPOPT_MD5SIG) {
 870                                 hash_location = ptr;
 871                                 goto done_opts;
 872                         }
 873                 }
 874                 ptr += opsize - 2;
 875                 length -= opsize;
 876         }
 877
 878 done_opts:
 879         /* do we have a hash as expected? */
 880         if (!hash_expected) {
 881                 if (!hash_location)
 882                         return 0;
 883                 if (net_ratelimit()) {
 884                         printk(KERN_INFO "MD5 Hash NOT expected but found "
 885                                "(" NIP6_FMT ", %u)->"
 886                                "(" NIP6_FMT ", %u)\n",
 887                                NIP6(ip6h->saddr), ntohs(th->source),
 888                                NIP6(ip6h->daddr), ntohs(th->dest));
 889                 }
 890                 return 1;
 891         }
 892
 893         if (!hash_location) {
 894                 if (net_ratelimit()) {
 895                         printk(KERN_INFO "MD5 Hash expected but NOT found "
 896                                "(" NIP6_FMT ", %u)->"
 897                                "(" NIP6_FMT ", %u)\n",
 898                                NIP6(ip6h->saddr), ntohs(th->source),
 899                                NIP6(ip6h->daddr), ntohs(th->dest));
 900                 }
 901                 return 1;
 902         }
 903
 904         /* check the signature */
 905         genhash = tcp_v6_do_calc_md5_hash(newhash,
 906                                           hash_expected,
 907                                           &ip6h->saddr, &ip6h->daddr,
 908                                           th, sk->sk_protocol,
 909                                           skb->len);
 910         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 911                 if (net_ratelimit()) {
 912                         printk(KERN_INFO "MD5 Hash %s for "
 913                                "(" NIP6_FMT ", %u)->"
 914                                "(" NIP6_FMT ", %u)\n",
 915                                genhash ? "failed" : "mismatch",
 916                                NIP6(ip6h->saddr), ntohs(th->source),
 917                                NIP6(ip6h->daddr), ntohs(th->dest));
 918                 }
 919                 return 1;
 920         }
 921         return 0;
 922 }
 923 #endif
 924
 925 static struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 926         .family         =       AF_INET6,
 927         .obj_size       =       sizeof(struct tcp6_request_sock),
 928         .rtx_syn_ack    =       tcp_v6_send_synack,
 929         .send_ack       =       tcp_v6_reqsk_send_ack,
 930         .destructor     =       tcp_v6_reqsk_destructor,
 931         .send_reset     =       tcp_v6_send_reset
 932 };
 933
 934 #ifdef CONFIG_TCP_MD5SIG
 935 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 936         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 937 };
 938 #endif
 939
 940 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 941         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 942         .twsk_unique    = tcp_twsk_unique,
 943         .twsk_destructor= tcp_twsk_destructor,
 944 };
 945
 946 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 947 {
 948         struct ipv6_pinfo *np = inet6_sk(sk);
 949         struct tcphdr *th = tcp_hdr(skb);
 950
 951         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 952                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 953                 skb->csum_offset = offsetof(struct tcphdr, check);
 954         } else {
 955                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 956                                             csum_partial((char *)th, th->doff<<2,
 957                                                          skb->csum));
 958         }
 959 }
 960
 961 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 962 {
 963         struct ipv6hdr *ipv6h;
 964         struct tcphdr *th;
 965
 966         if (!pskb_may_pull(skb, sizeof(*th)))
 967                 return -EINVAL;
 968
 969         ipv6h = ipv6_hdr(skb);
 970         th = tcp_hdr(skb);
 971
 972         th->check = 0;
 973         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 974                                      IPPROTO_TCP, 0);
 975         skb->csum_offset = offsetof(struct tcphdr, check);
 976         skb->ip_summed = CHECKSUM_PARTIAL;
 977         return 0;
 978 }
 979
 980 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 981 {
 982         struct tcphdr *th = tcp_hdr(skb), *t1;
 983         struct sk_buff *buff;
 984         struct flowi fl;
 985         int tot_len = sizeof(*th);
 986 #ifdef CONFIG_TCP_MD5SIG
 987         struct tcp_md5sig_key *key;
 988 #endif
 989
 990         if (th->rst)
 991                 return;
 992
 993         if (!ipv6_unicast_destination(skb))
 994                 return;
 995
 996 #ifdef CONFIG_TCP_MD5SIG
 997         if (sk)
 998                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
 999         else
1000                 key = NULL;
1001
1002         if (key)
1003                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1004 #endif
1005
1006         /*
1007          * We need to grab some memory, and put together an RST,
1008          * and then put it into the queue to be sent.
1009          */
1010
1011         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1012                          GFP_ATOMIC);
1013         if (buff == NULL)
1014                 return;
1015
1016         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1017
1018         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1019
1020         /* Swap the send and the receive. */
1021         memset(t1, 0, sizeof(*t1));
1022         t1->dest = th->source;
1023         t1->source = th->dest;
1024         t1->doff = tot_len / 4;
1025         t1->rst = 1;
1026
1027         if(th->ack) {
1028                 t1->seq = th->ack_seq;
1029         } else {
1030                 t1->ack = 1;
1031                 t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
1032                                     + skb->len - (th->doff<<2));
1033         }
1034
1035 #ifdef CONFIG_TCP_MD5SIG
1036         if (key) {
1037                 __be32 *opt = (__be32*)(t1 + 1);
1038                 opt[0] = htonl((TCPOPT_NOP << 24) |
1039                                (TCPOPT_NOP << 16) |
1040                                (TCPOPT_MD5SIG << 8) |
1041                                TCPOLEN_MD5SIG);
1042                 tcp_v6_do_calc_md5_hash((__u8 *)&opt[1], key,
1043                                         &ipv6_hdr(skb)->daddr,
1044                                         &ipv6_hdr(skb)->saddr,
1045                                         t1, IPPROTO_TCP, tot_len);
1046         }
1047 #endif
1048
1049         buff->csum = csum_partial((char *)t1, sizeof(*t1), 0);
1050
1051         memset(&fl, 0, sizeof(fl));
1052         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1053         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1054
1055         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1056                                     sizeof(*t1), IPPROTO_TCP,
1057                                     buff->csum);
1058
1059         fl.proto = IPPROTO_TCP;
1060         fl.oif = inet6_iif(skb);
1061         fl.fl_ip_dport = t1->dest;
1062         fl.fl_ip_sport = t1->source;
1063         security_skb_classify_flow(skb, &fl);
1064
1065         /* sk = NULL, but it is safe for now. RST socket required. */
1066         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1067
1068                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1069                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1070                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1071                         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
1072                         return;
1073                 }
1074         }
1075
1076         kfree_skb(buff);
1077 }
1078
1079 static void tcp_v6_send_ack(struct tcp_timewait_sock *tw,
1080                             struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
1081 {
1082         struct tcphdr *th = tcp_hdr(skb), *t1;
1083         struct sk_buff *buff;
1084         struct flowi fl;
1085         int tot_len = sizeof(struct tcphdr);
1086         __be32 *topt;
1087 #ifdef CONFIG_TCP_MD5SIG
1088         struct tcp_md5sig_key *key;
1089         struct tcp_md5sig_key tw_key;
1090 #endif
1091
1092 #ifdef CONFIG_TCP_MD5SIG
1093         if (!tw && skb->sk) {
1094                 key = tcp_v6_md5_do_lookup(skb->sk, &ipv6_hdr(skb)->daddr);
1095         } else if (tw && tw->tw_md5_keylen) {
1096                 tw_key.key = tw->tw_md5_key;
1097                 tw_key.keylen = tw->tw_md5_keylen;
1098                 key = &tw_key;
1099         } else {
1100                 key = NULL;
1101         }
1102 #endif
1103
1104         if (ts)
1105                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1106 #ifdef CONFIG_TCP_MD5SIG
1107         if (key)
1108                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1109 #endif
1110
1111         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1112                          GFP_ATOMIC);
1113         if (buff == NULL)
1114                 return;
1115
1116         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1117
1118         t1 = (struct tcphdr *) skb_push(buff,tot_len);
1119
1120         /* Swap the send and the receive. */
1121         memset(t1, 0, sizeof(*t1));
1122         t1->dest = th->source;
1123         t1->source = th->dest;
1124         t1->doff = tot_len/4;
1125         t1->seq = htonl(seq);
1126         t1->ack_seq = htonl(ack);
1127         t1->ack = 1;
1128         t1->window = htons(win);
1129
1130         topt = (__be32 *)(t1 + 1);
1131
1132         if (ts) {
1133                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1134                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1135                 *topt++ = htonl(tcp_time_stamp);
1136                 *topt = htonl(ts);
1137         }
1138
1139 #ifdef CONFIG_TCP_MD5SIG
1140         if (key) {
1141                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1142                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1143                 tcp_v6_do_calc_md5_hash((__u8 *)topt, key,
1144                                         &ipv6_hdr(skb)->daddr,
1145                                         &ipv6_hdr(skb)->saddr,
1146                                         t1, IPPROTO_TCP, tot_len);
1147         }
1148 #endif
1149
1150         buff->csum = csum_partial((char *)t1, tot_len, 0);
1151
1152         memset(&fl, 0, sizeof(fl));
1153         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1154         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1155
1156         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1157                                     tot_len, IPPROTO_TCP,
1158                                     buff->csum);
1159
1160         fl.proto = IPPROTO_TCP;
1161         fl.oif = inet6_iif(skb);
1162         fl.fl_ip_dport = t1->dest;
1163         fl.fl_ip_sport = t1->source;
1164         security_skb_classify_flow(skb, &fl);
1165
1166         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1167                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1168                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1169                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1170                         return;
1171                 }
1172         }
1173
1174         kfree_skb(buff);
1175 }
1176
1177 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1178 {
1179         struct inet_timewait_sock *tw = inet_twsk(sk);
1180         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1181
1182         tcp_v6_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1183                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1184                         tcptw->tw_ts_recent);
1185
1186         inet_twsk_put(tw);
1187 }
1188
1189 static void tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
1190 {
1191         tcp_v6_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent);
1192 }
1193
1194
1195 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1196 {
1197         struct request_sock *req, **prev;
1198         const struct tcphdr *th = tcp_hdr(skb);
1199         struct sock *nsk;
1200
1201         /* Find possible connection requests. */
1202         req = inet6_csk_search_req(sk, &prev, th->source,
1203                                    &ipv6_hdr(skb)->saddr,
1204                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1205         if (req)
1206                 return tcp_check_req(sk, skb, req, prev);
1207
1208         nsk = __inet6_lookup_established(&tcp_hashinfo, &ipv6_hdr(skb)->saddr,
1209                                          th->source, &ipv6_hdr(skb)->daddr,
1210                                          ntohs(th->dest), inet6_iif(skb));
1211
1212         if (nsk) {
1213                 if (nsk->sk_state != TCP_TIME_WAIT) {
1214                         bh_lock_sock(nsk);
1215                         return nsk;
1216                 }
1217                 inet_twsk_put(inet_twsk(nsk));
1218                 return NULL;
1219         }
1220
1221 #if 0 /*def CONFIG_SYN_COOKIES*/
1222         if (!th->rst && !th->syn && th->ack)
1223                 sk = cookie_v6_check(sk, skb, &(IPCB(skb)->opt));
1224 #endif
1225         return sk;
1226 }
1227
1228 /* FIXME: this is substantially similar to the ipv4 code.
1229  * Can some kind of merge be done? -- erics
1230  */
1231 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1232 {
1233         struct inet6_request_sock *treq;
1234         struct ipv6_pinfo *np = inet6_sk(sk);
1235         struct tcp_options_received tmp_opt;
1236         struct tcp_sock *tp = tcp_sk(sk);
1237         struct request_sock *req = NULL;
1238         __u32 isn = TCP_SKB_CB(skb)->when;
1239
1240         if (skb->protocol == htons(ETH_P_IP))
1241                 return tcp_v4_conn_request(sk, skb);
1242
1243         if (!ipv6_unicast_destination(skb))
1244                 goto drop;
1245
1246         /*
1247          *      There are no SYN attacks on IPv6, yet...
1248          */
1249         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1250                 if (net_ratelimit())
1251                         printk(KERN_INFO "TCPv6: dropping request, synflood is possible\n");
1252                 goto drop;
1253         }
1254
1255         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1256                 goto drop;
1257
1258         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1259         if (req == NULL)
1260                 goto drop;
1261
1262 #ifdef CONFIG_TCP_MD5SIG
1263         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1264 #endif
1265
1266         tcp_clear_options(&tmp_opt);
1267         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1268         tmp_opt.user_mss = tp->rx_opt.user_mss;
1269
1270         tcp_parse_options(skb, &tmp_opt, 0);
1271
1272         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1273         tcp_openreq_init(req, &tmp_opt, skb);
1274
1275         treq = inet6_rsk(req);
1276         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1277         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1278         TCP_ECN_create_request(req, tcp_hdr(skb));
1279         treq->pktopts = NULL;
1280         if (ipv6_opt_accepted(sk, skb) ||
1281             np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1282             np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1283                 atomic_inc(&skb->users);
1284                 treq->pktopts = skb;
1285         }
1286         treq->iif = sk->sk_bound_dev_if;
1287
1288         /* So that link locals have meaning */
1289         if (!sk->sk_bound_dev_if &&
1290             ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1291                 treq->iif = inet6_iif(skb);
1292
1293         if (isn == 0)
1294                 isn = tcp_v6_init_sequence(skb);
1295
1296         tcp_rsk(req)->snt_isn = isn;
1297
1298         security_inet_conn_request(sk, skb, req);
1299
1300         if (tcp_v6_send_synack(sk, req, NULL))
1301                 goto drop;
1302
1303         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1304         return 0;
1305
1306 drop:
1307         if (req)
1308                 reqsk_free(req);
1309
1310         return 0; /* don't send reset */
1311 }
1312
1313 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1314                                           struct request_sock *req,
1315                                           struct dst_entry *dst)
1316 {
1317         struct inet6_request_sock *treq = inet6_rsk(req);
1318         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1319         struct tcp6_sock *newtcp6sk;
1320         struct inet_sock *newinet;
1321         struct tcp_sock *newtp;
1322         struct sock *newsk;
1323         struct ipv6_txoptions *opt;
1324 #ifdef CONFIG_TCP_MD5SIG
1325         struct tcp_md5sig_key *key;
1326 #endif
1327
1328         if (skb->protocol == htons(ETH_P_IP)) {
1329                 /*
1330                  *      v6 mapped
1331                  */
1332
1333                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1334
1335                 if (newsk == NULL)
1336                         return NULL;
1337
1338                 newtcp6sk = (struct tcp6_sock *)newsk;
1339                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1340
1341                 newinet = inet_sk(newsk);
1342                 newnp = inet6_sk(newsk);
1343                 newtp = tcp_sk(newsk);
1344
1345                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1346
1347                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1348                               newinet->daddr);
1349
1350                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1351                               newinet->saddr);
1352
1353                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1354
1355                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1356                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1357 #ifdef CONFIG_TCP_MD5SIG
1358                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1359 #endif
1360
1361                 newnp->pktoptions  = NULL;
1362                 newnp->opt         = NULL;
1363                 newnp->mcast_oif   = inet6_iif(skb);
1364                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1365
1366                 /*
1367                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1368                  * here, tcp_create_openreq_child now does this for us, see the comment in
1369                  * that function for the gory details. -acme
1370                  */
1371
1372                 /* It is tricky place. Until this moment IPv4 tcp
1373                    worked with IPv6 icsk.icsk_af_ops.
1374                    Sync it now.
1375                  */
1376                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1377
1378                 return newsk;
1379         }
1380
1381         opt = np->opt;
1382
1383         if (sk_acceptq_is_full(sk))
1384                 goto out_overflow;
1385
1386         if (np->rxopt.bits.osrcrt == 2 &&
1387             opt == NULL && treq->pktopts) {
1388                 struct inet6_skb_parm *rxopt = IP6CB(treq->pktopts);
1389                 if (rxopt->srcrt)
1390                         opt = ipv6_invert_rthdr(sk,
1391                    (struct ipv6_rt_hdr *)(skb_network_header(treq->pktopts) +
1392                                           rxopt->srcrt));
1393         }
1394
1395         if (dst == NULL) {
1396                 struct in6_addr *final_p = NULL, final;
1397                 struct flowi fl;
1398
1399                 memset(&fl, 0, sizeof(fl));
1400                 fl.proto = IPPROTO_TCP;
1401                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1402                 if (opt && opt->srcrt) {
1403                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1404                         ipv6_addr_copy(&final, &fl.fl6_dst);
1405                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1406                         final_p = &final;
1407                 }
1408                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1409                 fl.oif = sk->sk_bound_dev_if;
1410                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1411                 fl.fl_ip_sport = inet_sk(sk)->sport;
1412                 security_req_classify_flow(req, &fl);
1413
1414                 if (ip6_dst_lookup(sk, &dst, &fl))
1415                         goto out;
1416
1417                 if (final_p)
1418                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1419
1420                 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
1421                         goto out;
1422         }
1423
1424         newsk = tcp_create_openreq_child(sk, req, skb);
1425         if (newsk == NULL)
1426                 goto out;
1427
1428         /*
1429          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1430          * count here, tcp_create_openreq_child now does this for us, see the
1431          * comment in that function for the gory details. -acme
1432          */
1433
1434         newsk->sk_gso_type = SKB_GSO_TCPV6;
1435         __ip6_dst_store(newsk, dst, NULL, NULL);
1436
1437         newtcp6sk = (struct tcp6_sock *)newsk;
1438         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1439
1440         newtp = tcp_sk(newsk);
1441         newinet = inet_sk(newsk);
1442         newnp = inet6_sk(newsk);
1443
1444         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1445
1446         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1447         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1448         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1449         newsk->sk_bound_dev_if = treq->iif;
1450
1451         /* Now IPv6 options...
1452
1453            First: no IPv4 options.
1454          */
1455         newinet->opt = NULL;
1456         newnp->ipv6_fl_list = NULL;
1457
1458         /* Clone RX bits */
1459         newnp->rxopt.all = np->rxopt.all;
1460
1461         /* Clone pktoptions received with SYN */
1462         newnp->pktoptions = NULL;
1463         if (treq->pktopts != NULL) {
1464                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1465                 kfree_skb(treq->pktopts);
1466                 treq->pktopts = NULL;
1467                 if (newnp->pktoptions)
1468                         skb_set_owner_r(newnp->pktoptions, newsk);
1469         }
1470         newnp->opt        = NULL;
1471         newnp->mcast_oif  = inet6_iif(skb);
1472         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1473
1474         /* Clone native IPv6 options from listening socket (if any)
1475
1476            Yes, keeping reference count would be much more clever,
1477            but we make one more one thing there: reattach optmem
1478            to newsk.
1479          */
1480         if (opt) {
1481                 newnp->opt = ipv6_dup_options(newsk, opt);
1482                 if (opt != np->opt)
1483                         sock_kfree_s(sk, opt, opt->tot_len);
1484         }
1485
1486         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1487         if (newnp->opt)
1488                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1489                                                      newnp->opt->opt_flen);
1490
1491         tcp_mtup_init(newsk);
1492         tcp_sync_mss(newsk, dst_mtu(dst));
1493         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1494         tcp_initialize_rcv_mss(newsk);
1495
1496         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1497
1498 #ifdef CONFIG_TCP_MD5SIG
1499         /* Copy over the MD5 key from the original socket */
1500         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1501                 /* We're using one, so create a matching key
1502                  * on the newsk structure. If we fail to get
1503                  * memory, then we end up not copying the key
1504                  * across. Shucks.
1505                  */
1506                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1507                 if (newkey != NULL)
1508                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1509                                           newkey, key->keylen);
1510         }
1511 #endif
1512
1513         __inet6_hash(&tcp_hashinfo, newsk);
1514         inet_inherit_port(&tcp_hashinfo, sk, newsk);
1515
1516         return newsk;
1517
1518 out_overflow:
1519         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
1520 out:
1521         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
1522         if (opt && opt != np->opt)
1523                 sock_kfree_s(sk, opt, opt->tot_len);
1524         dst_release(dst);
1525         return NULL;
1526 }
1527
1528 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1529 {
1530         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1531                 if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1532                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1533                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1534                         return 0;
1535                 }
1536         }
1537
1538         skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1539                                               &ipv6_hdr(skb)->saddr,
1540                                               &ipv6_hdr(skb)->daddr, 0));
1541
1542         if (skb->len <= 76) {
1543                 return __skb_checksum_complete(skb);
1544         }
1545         return 0;
1546 }
1547
1548 /* The socket must have it's spinlock held when we get
1549  * here.
1550  *
1551  * We have a potential double-lock case here, so even when
1552  * doing backlog processing we use the BH locking scheme.
1553  * This is because we cannot sleep with the original spinlock
1554  * held.
1555  */
1556 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1557 {
1558         struct ipv6_pinfo *np = inet6_sk(sk);
1559         struct tcp_sock *tp;
1560         struct sk_buff *opt_skb = NULL;
1561
1562         /* Imagine: socket is IPv6. IPv4 packet arrives,
1563            goes to IPv4 receive handler and backlogged.
1564            From backlog it always goes here. Kerboom...
1565            Fortunately, tcp_rcv_established and rcv_established
1566            handle them correctly, but it is not case with
1567            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1568          */
1569
1570         if (skb->protocol == htons(ETH_P_IP))
1571                 return tcp_v4_do_rcv(sk, skb);
1572
1573 #ifdef CONFIG_TCP_MD5SIG
1574         if (tcp_v6_inbound_md5_hash (sk, skb))
1575                 goto discard;
1576 #endif
1577
1578         if (sk_filter(sk, skb))
1579                 goto discard;
1580
1581         /*
1582          *      socket locking is here for SMP purposes as backlog rcv
1583          *      is currently called with bh processing disabled.
1584          */
1585
1586         /* Do Stevens' IPV6_PKTOPTIONS.
1587
1588            Yes, guys, it is the only place in our code, where we
1589            may make it not affecting IPv4.
1590            The rest of code is protocol independent,
1591            and I do not like idea to uglify IPv4.
1592
1593            Actually, all the idea behind IPV6_PKTOPTIONS
1594            looks not very well thought. For now we latch
1595            options, received in the last packet, enqueued
1596            by tcp. Feel free to propose better solution.
1597                                                --ANK (980728)
1598          */
1599         if (np->rxopt.all)
1600                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1601
1602         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1603                 TCP_CHECK_TIMER(sk);
1604                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1605                         goto reset;
1606                 TCP_CHECK_TIMER(sk);
1607                 if (opt_skb)
1608                         goto ipv6_pktoptions;
1609                 return 0;
1610         }
1611
1612         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1613                 goto csum_err;
1614
1615         if (sk->sk_state == TCP_LISTEN) {
1616                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1617                 if (!nsk)
1618                         goto discard;
1619
1620                 /*
1621                  * Queue it on the new socket if the new socket is active,
1622                  * otherwise we just shortcircuit this and continue with
1623                  * the new socket..
1624                  */
1625                 if(nsk != sk) {
1626                         if (tcp_child_process(sk, nsk, skb))
1627                                 goto reset;
1628                         if (opt_skb)
1629                                 __kfree_skb(opt_skb);
1630                         return 0;
1631                 }
1632         }
1633
1634         TCP_CHECK_TIMER(sk);
1635         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1636                 goto reset;
1637         TCP_CHECK_TIMER(sk);
1638         if (opt_skb)
1639                 goto ipv6_pktoptions;
1640         return 0;
1641
1642 reset:
1643         tcp_v6_send_reset(sk, skb);
1644 discard:
1645         if (opt_skb)
1646                 __kfree_skb(opt_skb);
1647         kfree_skb(skb);
1648         return 0;
1649 csum_err:
1650         TCP_INC_STATS_BH(TCP_MIB_INERRS);
1651         goto discard;
1652
1653
1654 ipv6_pktoptions:
1655         /* Do you ask, what is it?
1656
1657            1. skb was enqueued by tcp.
1658            2. skb is added to tail of read queue, rather than out of order.
1659            3. socket is not in passive state.
1660            4. Finally, it really contains options, which user wants to receive.
1661          */
1662         tp = tcp_sk(sk);
1663         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1664             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1665                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1666                         np->mcast_oif = inet6_iif(opt_skb);
1667                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1668                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1669                 if (ipv6_opt_accepted(sk, opt_skb)) {
1670                         skb_set_owner_r(opt_skb, sk);
1671                         opt_skb = xchg(&np->pktoptions, opt_skb);
1672                 } else {
1673                         __kfree_skb(opt_skb);
1674                         opt_skb = xchg(&np->pktoptions, NULL);
1675                 }
1676         }
1677
1678         if (opt_skb)
1679                 kfree_skb(opt_skb);
1680         return 0;
1681 }
1682
1683 static int tcp_v6_rcv(struct sk_buff **pskb)
1684 {
1685         struct sk_buff *skb = *pskb;
1686         struct tcphdr *th;
1687         struct sock *sk;
1688         int ret;
1689
1690         if (skb->pkt_type != PACKET_HOST)
1691                 goto discard_it;
1692
1693         /*
1694          *      Count it even if it's bad.
1695          */
1696         TCP_INC_STATS_BH(TCP_MIB_INSEGS);
1697
1698         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1699                 goto discard_it;
1700
1701         th = tcp_hdr(skb);
1702
1703         if (th->doff < sizeof(struct tcphdr)/4)
1704                 goto bad_packet;
1705         if (!pskb_may_pull(skb, th->doff*4))
1706                 goto discard_it;
1707
1708         if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
1709              tcp_v6_checksum_init(skb)))
1710                 goto bad_packet;
1711
1712         th = tcp_hdr(skb);
1713         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1714         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1715                                     skb->len - th->doff*4);
1716         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1717         TCP_SKB_CB(skb)->when = 0;
1718         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1719         TCP_SKB_CB(skb)->sacked = 0;
1720
1721         sk = __inet6_lookup(&tcp_hashinfo, &ipv6_hdr(skb)->saddr, th->source,
1722                             &ipv6_hdr(skb)->daddr, ntohs(th->dest),
1723                             inet6_iif(skb));
1724
1725         if (!sk)
1726                 goto no_tcp_socket;
1727
1728 process:
1729         if (sk->sk_state == TCP_TIME_WAIT)
1730                 goto do_time_wait;
1731
1732         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1733                 goto discard_and_relse;
1734
1735         if (sk_filter(sk, skb))
1736                 goto discard_and_relse;
1737
1738         skb->dev = NULL;
1739
1740         bh_lock_sock_nested(sk);
1741         ret = 0;
1742         if (!sock_owned_by_user(sk)) {
1743 #ifdef CONFIG_NET_DMA
1744                 struct tcp_sock *tp = tcp_sk(sk);
1745                 if (tp->ucopy.dma_chan)
1746                         ret = tcp_v6_do_rcv(sk, skb);
1747                 else
1748 #endif
1749                 {
1750                         if (!tcp_prequeue(sk, skb))
1751                                 ret = tcp_v6_do_rcv(sk, skb);
1752                 }
1753         } else
1754                 sk_add_backlog(sk, skb);
1755         bh_unlock_sock(sk);
1756
1757         sock_put(sk);
1758         return ret ? -1 : 0;
1759
1760 no_tcp_socket:
1761         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1762                 goto discard_it;
1763
1764         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1765 bad_packet:
1766                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1767         } else {
1768                 tcp_v6_send_reset(NULL, skb);
1769         }
1770
1771 discard_it:
1772
1773         /*
1774          *      Discard frame
1775          */
1776
1777         kfree_skb(skb);
1778         return 0;
1779
1780 discard_and_relse:
1781         sock_put(sk);
1782         goto discard_it;
1783
1784 do_time_wait:
1785         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1786                 inet_twsk_put(inet_twsk(sk));
1787                 goto discard_it;
1788         }
1789
1790         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1791                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1792                 inet_twsk_put(inet_twsk(sk));
1793                 goto discard_it;
1794         }
1795
1796         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1797         case TCP_TW_SYN:
1798         {
1799                 struct sock *sk2;
1800
1801                 sk2 = inet6_lookup_listener(&tcp_hashinfo,
1802                                             &ipv6_hdr(skb)->daddr,
1803                                             ntohs(th->dest), inet6_iif(skb));
1804                 if (sk2 != NULL) {
1805                         struct inet_timewait_sock *tw = inet_twsk(sk);
1806                         inet_twsk_deschedule(tw, &tcp_death_row);
1807                         inet_twsk_put(tw);
1808                         sk = sk2;
1809                         goto process;
1810                 }
1811                 /* Fall through to ACK */
1812         }
1813         case TCP_TW_ACK:
1814                 tcp_v6_timewait_ack(sk, skb);
1815                 break;
1816         case TCP_TW_RST:
1817                 goto no_tcp_socket;
1818         case TCP_TW_SUCCESS:;
1819         }
1820         goto discard_it;
1821 }
1822
1823 static int tcp_v6_remember_stamp(struct sock *sk)
1824 {
1825         /* Alas, not yet... */
1826         return 0;
1827 }
1828
1829 static struct inet_connection_sock_af_ops ipv6_specific = {
1830         .queue_xmit        = inet6_csk_xmit,
1831         .send_check        = tcp_v6_send_check,
1832         .rebuild_header    = inet6_sk_rebuild_header,
1833         .conn_request      = tcp_v6_conn_request,
1834         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1835         .remember_stamp    = tcp_v6_remember_stamp,
1836         .net_header_len    = sizeof(struct ipv6hdr),
1837         .setsockopt        = ipv6_setsockopt,
1838         .getsockopt        = ipv6_getsockopt,
1839         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1840         .sockaddr_len      = sizeof(struct sockaddr_in6),
1841 #ifdef CONFIG_COMPAT
1842         .compat_setsockopt = compat_ipv6_setsockopt,
1843         .compat_getsockopt = compat_ipv6_getsockopt,
1844 #endif
1845 };
1846
1847 #ifdef CONFIG_TCP_MD5SIG
1848 static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1849         .md5_lookup     =       tcp_v6_md5_lookup,
1850         .calc_md5_hash  =       tcp_v6_calc_md5_hash,
1851         .md5_add        =       tcp_v6_md5_add_func,
1852         .md5_parse      =       tcp_v6_parse_md5_keys,
1853 };
1854 #endif
1855
1856 /*
1857  *      TCP over IPv4 via INET6 API
1858  */
1859
1860 static struct inet_connection_sock_af_ops ipv6_mapped = {
1861         .queue_xmit        = ip_queue_xmit,
1862         .send_check        = tcp_v4_send_check,
1863         .rebuild_header    = inet_sk_rebuild_header,
1864         .conn_request      = tcp_v6_conn_request,
1865         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1866         .remember_stamp    = tcp_v4_remember_stamp,
1867         .net_header_len    = sizeof(struct iphdr),
1868         .setsockopt        = ipv6_setsockopt,
1869         .getsockopt        = ipv6_getsockopt,
1870         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1871         .sockaddr_len      = sizeof(struct sockaddr_in6),
1872 #ifdef CONFIG_COMPAT
1873         .compat_setsockopt = compat_ipv6_setsockopt,
1874         .compat_getsockopt = compat_ipv6_getsockopt,
1875 #endif
1876 };
1877
1878 #ifdef CONFIG_TCP_MD5SIG
1879 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1880         .md5_lookup     =       tcp_v4_md5_lookup,
1881         .calc_md5_hash  =       tcp_v4_calc_md5_hash,
1882         .md5_add        =       tcp_v6_md5_add_func,
1883         .md5_parse      =       tcp_v6_parse_md5_keys,
1884 };
1885 #endif
1886
1887 /* NOTE: A lot of things set to zero explicitly by call to
1888  *       sk_alloc() so need not be done here.
1889  */
1890 static int tcp_v6_init_sock(struct sock *sk)
1891 {
1892         struct inet_connection_sock *icsk = inet_csk(sk);
1893         struct tcp_sock *tp = tcp_sk(sk);
1894
1895         skb_queue_head_init(&tp->out_of_order_queue);
1896         tcp_init_xmit_timers(sk);
1897         tcp_prequeue_init(tp);
1898
1899         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1900         tp->mdev = TCP_TIMEOUT_INIT;
1901
1902         /* So many TCP implementations out there (incorrectly) count the
1903          * initial SYN frame in their delayed-ACK and congestion control
1904          * algorithms that we must have the following bandaid to talk
1905          * efficiently to them.  -DaveM
1906          */
1907         tp->snd_cwnd = 2;
1908
1909         /* See draft-stevens-tcpca-spec-01 for discussion of the
1910          * initialization of these values.
1911          */
1912         tp->snd_ssthresh = 0x7fffffff;
1913         tp->snd_cwnd_clamp = ~0;
1914         tp->mss_cache = 536;
1915
1916         tp->reordering = sysctl_tcp_reordering;
1917
1918         sk->sk_state = TCP_CLOSE;
1919
1920         icsk->icsk_af_ops = &ipv6_specific;
1921         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1922         icsk->icsk_sync_mss = tcp_sync_mss;
1923         sk->sk_write_space = sk_stream_write_space;
1924         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1925
1926 #ifdef CONFIG_TCP_MD5SIG
1927         tp->af_specific = &tcp_sock_ipv6_specific;
1928 #endif
1929
1930         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1931         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1932
1933         atomic_inc(&tcp_sockets_allocated);
1934
1935         return 0;
1936 }
1937
1938 static int tcp_v6_destroy_sock(struct sock *sk)
1939 {
1940 #ifdef CONFIG_TCP_MD5SIG
1941         /* Clean up the MD5 key list */
1942         if (tcp_sk(sk)->md5sig_info)
1943                 tcp_v6_clear_md5_list(sk);
1944 #endif
1945         tcp_v4_destroy_sock(sk);
1946         return inet6_destroy_sock(sk);
1947 }
1948
1949 /* Proc filesystem TCPv6 sock list dumping. */
1950 static void get_openreq6(struct seq_file *seq,
1951                          struct sock *sk, struct request_sock *req, int i, int uid)
1952 {
1953         int ttd = req->expires - jiffies;
1954         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1955         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1956
1957         if (ttd < 0)
1958                 ttd = 0;
1959
1960         seq_printf(seq,
1961                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1962                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1963                    i,
1964                    src->s6_addr32[0], src->s6_addr32[1],
1965                    src->s6_addr32[2], src->s6_addr32[3],
1966                    ntohs(inet_sk(sk)->sport),
1967                    dest->s6_addr32[0], dest->s6_addr32[1],
1968                    dest->s6_addr32[2], dest->s6_addr32[3],
1969                    ntohs(inet_rsk(req)->rmt_port),
1970                    TCP_SYN_RECV,
1971                    0,0, /* could print option size, but that is af dependent. */
1972                    1,   /* timers active (only the expire timer) */
1973                    jiffies_to_clock_t(ttd),
1974                    req->retrans,
1975                    uid,
1976                    0,  /* non standard timer */
1977                    0, /* open_requests have no inode */
1978                    0, req);
1979 }
1980
1981 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1982 {
1983         struct in6_addr *dest, *src;
1984         __u16 destp, srcp;
1985         int timer_active;
1986         unsigned long timer_expires;
1987         struct inet_sock *inet = inet_sk(sp);
1988         struct tcp_sock *tp = tcp_sk(sp);
1989         const struct inet_connection_sock *icsk = inet_csk(sp);
1990         struct ipv6_pinfo *np = inet6_sk(sp);
1991
1992         dest  = &np->daddr;
1993         src   = &np->rcv_saddr;
1994         destp = ntohs(inet->dport);
1995         srcp  = ntohs(inet->sport);
1996
1997         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1998                 timer_active    = 1;
1999                 timer_expires   = icsk->icsk_timeout;
2000         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2001                 timer_active    = 4;
2002                 timer_expires   = icsk->icsk_timeout;
2003         } else if (timer_pending(&sp->sk_timer)) {
2004                 timer_active    = 2;
2005                 timer_expires   = sp->sk_timer.expires;
2006         } else {
2007                 timer_active    = 0;
2008                 timer_expires = jiffies;
2009         }
2010
2011         seq_printf(seq,
2012                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2013                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d\n",
2014                    i,
2015                    src->s6_addr32[0], src->s6_addr32[1],
2016                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2017                    dest->s6_addr32[0], dest->s6_addr32[1],
2018                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2019                    sp->sk_state,
2020                    tp->write_seq-tp->snd_una,
2021                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2022                    timer_active,
2023                    jiffies_to_clock_t(timer_expires - jiffies),
2024                    icsk->icsk_retransmits,
2025                    sock_i_uid(sp),
2026                    icsk->icsk_probes_out,
2027                    sock_i_ino(sp),
2028                    atomic_read(&sp->sk_refcnt), sp,
2029                    icsk->icsk_rto,
2030                    icsk->icsk_ack.ato,
2031                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2032                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
2033                    );
2034 }
2035
2036 static void get_timewait6_sock(struct seq_file *seq,
2037                                struct inet_timewait_sock *tw, int i)
2038 {
2039         struct in6_addr *dest, *src;
2040         __u16 destp, srcp;
2041         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2042         int ttd = tw->tw_ttd - jiffies;
2043
2044         if (ttd < 0)
2045                 ttd = 0;
2046
2047         dest = &tw6->tw_v6_daddr;
2048         src  = &tw6->tw_v6_rcv_saddr;
2049         destp = ntohs(tw->tw_dport);
2050         srcp  = ntohs(tw->tw_sport);
2051
2052         seq_printf(seq,
2053                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2054                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2055                    i,
2056                    src->s6_addr32[0], src->s6_addr32[1],
2057                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2058                    dest->s6_addr32[0], dest->s6_addr32[1],
2059                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2060                    tw->tw_substate, 0, 0,
2061                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2062                    atomic_read(&tw->tw_refcnt), tw);
2063 }
2064
2065 #ifdef CONFIG_PROC_FS
2066 static int tcp6_seq_show(struct seq_file *seq, void *v)
2067 {
2068         struct tcp_iter_state *st;
2069
2070         if (v == SEQ_START_TOKEN) {
2071                 seq_puts(seq,
2072                          "  sl  "
2073                          "local_address                         "
2074                          "remote_address                        "
2075                          "st tx_queue rx_queue tr tm->when retrnsmt"
2076                          "   uid  timeout inode\n");
2077                 goto out;
2078         }
2079         st = seq->private;
2080
2081         switch (st->state) {
2082         case TCP_SEQ_STATE_LISTENING:
2083         case TCP_SEQ_STATE_ESTABLISHED:
2084                 get_tcp6_sock(seq, v, st->num);
2085                 break;
2086         case TCP_SEQ_STATE_OPENREQ:
2087                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2088                 break;
2089         case TCP_SEQ_STATE_TIME_WAIT:
2090                 get_timewait6_sock(seq, v, st->num);
2091                 break;
2092         }
2093 out:
2094         return 0;
2095 }
2096
2097 static struct file_operations tcp6_seq_fops;
2098 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2099         .owner          = THIS_MODULE,
2100         .name           = "tcp6",
2101         .family         = AF_INET6,
2102         .seq_show       = tcp6_seq_show,
2103         .seq_fops       = &tcp6_seq_fops,
2104 };
2105
2106 int __init tcp6_proc_init(void)
2107 {
2108         return tcp_proc_register(&tcp6_seq_afinfo);
2109 }
2110
2111 void tcp6_proc_exit(void)
2112 {
2113         tcp_proc_unregister(&tcp6_seq_afinfo);
2114 }
2115 #endif
2116
2117 struct proto tcpv6_prot = {
2118         .name                   = "TCPv6",
2119         .owner                  = THIS_MODULE,
2120         .close                  = tcp_close,
2121         .connect                = tcp_v6_connect,
2122         .disconnect             = tcp_disconnect,
2123         .accept                 = inet_csk_accept,
2124         .ioctl                  = tcp_ioctl,
2125         .init                   = tcp_v6_init_sock,
2126         .destroy                = tcp_v6_destroy_sock,
2127         .shutdown               = tcp_shutdown,
2128         .setsockopt             = tcp_setsockopt,
2129         .getsockopt             = tcp_getsockopt,
2130         .sendmsg                = tcp_sendmsg,
2131         .recvmsg                = tcp_recvmsg,
2132         .backlog_rcv            = tcp_v6_do_rcv,
2133         .hash                   = tcp_v6_hash,
2134         .unhash                 = tcp_unhash,
2135         .get_port               = tcp_v6_get_port,
2136         .enter_memory_pressure  = tcp_enter_memory_pressure,
2137         .sockets_allocated      = &tcp_sockets_allocated,
2138         .memory_allocated       = &tcp_memory_allocated,
2139         .memory_pressure        = &tcp_memory_pressure,
2140         .orphan_count           = &tcp_orphan_count,
2141         .sysctl_mem             = sysctl_tcp_mem,
2142         .sysctl_wmem            = sysctl_tcp_wmem,
2143         .sysctl_rmem            = sysctl_tcp_rmem,
2144         .max_header             = MAX_TCP_HEADER,
2145         .obj_size               = sizeof(struct tcp6_sock),
2146         .twsk_prot              = &tcp6_timewait_sock_ops,
2147         .rsk_prot               = &tcp6_request_sock_ops,
2148 #ifdef CONFIG_COMPAT
2149         .compat_setsockopt      = compat_tcp_setsockopt,
2150         .compat_getsockopt      = compat_tcp_getsockopt,
2151 #endif
2152 };
2153
2154 static struct inet6_protocol tcpv6_protocol = {
2155         .handler        =       tcp_v6_rcv,
2156         .err_handler    =       tcp_v6_err,
2157         .gso_send_check =       tcp_v6_gso_send_check,
2158         .gso_segment    =       tcp_tso_segment,
2159         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2160 };
2161
2162 static struct inet_protosw tcpv6_protosw = {
2163         .type           =       SOCK_STREAM,
2164         .protocol       =       IPPROTO_TCP,
2165         .prot           =       &tcpv6_prot,
2166         .ops            =       &inet6_stream_ops,
2167         .capability     =       -1,
2168         .no_check       =       0,
2169         .flags          =       INET_PROTOSW_PERMANENT |
2170                                 INET_PROTOSW_ICSK,
2171 };
2172
2173 void __init tcpv6_init(void)
2174 {
2175         /* register inet6 protocol */
2176         if (inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP) < 0)
2177                 printk(KERN_ERR "tcpv6_init: Could not register protocol\n");
2178         inet6_register_protosw(&tcpv6_protosw);
2179
2180         if (inet_csk_ctl_sock_create(&tcp6_socket, PF_INET6, SOCK_RAW,
2181                                      IPPROTO_TCP) < 0)
2182                 panic("Failed to create the TCPv6 control socket.\n");
2183 }