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   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                 if (err == -EREMOTE)
 270                         err = ip6_dst_blackhole(sk, &dst, &fl);
 271                 if (err < 0)
 272                         goto failure;
 273         }
 274
 275         if (saddr == NULL) {
 276                 saddr = &fl.fl6_src;
 277                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 278         }
 279
 280         /* set the source address */
 281         ipv6_addr_copy(&np->saddr, saddr);
 282         inet->rcv_saddr = LOOPBACK4_IPV6;
 283
 284         sk->sk_gso_type = SKB_GSO_TCPV6;
 285         __ip6_dst_store(sk, dst, NULL, NULL);
 286
 287         icsk->icsk_ext_hdr_len = 0;
 288         if (np->opt)
 289                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 290                                           np->opt->opt_nflen);
 291
 292         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 293
 294         inet->dport = usin->sin6_port;
 295
 296         tcp_set_state(sk, TCP_SYN_SENT);
 297         err = inet6_hash_connect(&tcp_death_row, sk);
 298         if (err)
 299                 goto late_failure;
 300
 301         if (!tp->write_seq)
 302                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 303                                                              np->daddr.s6_addr32,
 304                                                              inet->sport,
 305                                                              inet->dport);
 306
 307         err = tcp_connect(sk);
 308         if (err)
 309                 goto late_failure;
 310
 311         return 0;
 312
 313 late_failure:
 314         tcp_set_state(sk, TCP_CLOSE);
 315         __sk_dst_reset(sk);
 316 failure:
 317         inet->dport = 0;
 318         sk->sk_route_caps = 0;
 319         return err;
 320 }
 321
 322 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 323                 int type, int code, int offset, __be32 info)
 324 {
 325         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
 326         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 327         struct ipv6_pinfo *np;
 328         struct sock *sk;
 329         int err;
 330         struct tcp_sock *tp;
 331         __u32 seq;
 332
 333         sk = inet6_lookup(&tcp_hashinfo, &hdr->daddr, th->dest, &hdr->saddr,
 334                           th->source, skb->dev->ifindex);
 335
 336         if (sk == NULL) {
 337                 ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 338                 return;
 339         }
 340
 341         if (sk->sk_state == TCP_TIME_WAIT) {
 342                 inet_twsk_put(inet_twsk(sk));
 343                 return;
 344         }
 345
 346         bh_lock_sock(sk);
 347         if (sock_owned_by_user(sk))
 348                 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
 349
 350         if (sk->sk_state == TCP_CLOSE)
 351                 goto out;
 352
 353         tp = tcp_sk(sk);
 354         seq = ntohl(th->seq);
 355         if (sk->sk_state != TCP_LISTEN &&
 356             !between(seq, tp->snd_una, tp->snd_nxt)) {
 357                 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 358                 goto out;
 359         }
 360
 361         np = inet6_sk(sk);
 362
 363         if (type == ICMPV6_PKT_TOOBIG) {
 364                 struct dst_entry *dst = NULL;
 365
 366                 if (sock_owned_by_user(sk))
 367                         goto out;
 368                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 369                         goto out;
 370
 371                 /* icmp should have updated the destination cache entry */
 372                 dst = __sk_dst_check(sk, np->dst_cookie);
 373
 374                 if (dst == NULL) {
 375                         struct inet_sock *inet = inet_sk(sk);
 376                         struct flowi fl;
 377
 378                         /* BUGGG_FUTURE: Again, it is not clear how
 379                            to handle rthdr case. Ignore this complexity
 380                            for now.
 381                          */
 382                         memset(&fl, 0, sizeof(fl));
 383                         fl.proto = IPPROTO_TCP;
 384                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 385                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 386                         fl.oif = sk->sk_bound_dev_if;
 387                         fl.fl_ip_dport = inet->dport;
 388                         fl.fl_ip_sport = inet->sport;
 389                         security_skb_classify_flow(skb, &fl);
 390
 391                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
 392                                 sk->sk_err_soft = -err;
 393                                 goto out;
 394                         }
 395
 396                         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 397                                 sk->sk_err_soft = -err;
 398                                 goto out;
 399                         }
 400
 401                 } else
 402                         dst_hold(dst);
 403
 404                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 405                         tcp_sync_mss(sk, dst_mtu(dst));
 406                         tcp_simple_retransmit(sk);
 407                 } /* else let the usual retransmit timer handle it */
 408                 dst_release(dst);
 409                 goto out;
 410         }
 411
 412         icmpv6_err_convert(type, code, &err);
 413
 414         /* Might be for an request_sock */
 415         switch (sk->sk_state) {
 416                 struct request_sock *req, **prev;
 417         case TCP_LISTEN:
 418                 if (sock_owned_by_user(sk))
 419                         goto out;
 420
 421                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 422                                            &hdr->saddr, inet6_iif(skb));
 423                 if (!req)
 424                         goto out;
 425
 426                 /* ICMPs are not backlogged, hence we cannot get
 427                  * an established socket here.
 428                  */
 429                 BUG_TRAP(req->sk == NULL);
 430
 431                 if (seq != tcp_rsk(req)->snt_isn) {
 432                         NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 433                         goto out;
 434                 }
 435
 436                 inet_csk_reqsk_queue_drop(sk, req, prev);
 437                 goto out;
 438
 439         case TCP_SYN_SENT:
 440         case TCP_SYN_RECV:  /* Cannot happen.
 441                                It can, it SYNs are crossed. --ANK */
 442                 if (!sock_owned_by_user(sk)) {
 443                         sk->sk_err = err;
 444                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 445
 446                         tcp_done(sk);
 447                 } else
 448                         sk->sk_err_soft = err;
 449                 goto out;
 450         }
 451
 452         if (!sock_owned_by_user(sk) && np->recverr) {
 453                 sk->sk_err = err;
 454                 sk->sk_error_report(sk);
 455         } else
 456                 sk->sk_err_soft = err;
 457
 458 out:
 459         bh_unlock_sock(sk);
 460         sock_put(sk);
 461 }
 462
 463
 464 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
 465                               struct dst_entry *dst)
 466 {
 467         struct inet6_request_sock *treq = inet6_rsk(req);
 468         struct ipv6_pinfo *np = inet6_sk(sk);
 469         struct sk_buff * skb;
 470         struct ipv6_txoptions *opt = NULL;
 471         struct in6_addr * final_p = NULL, final;
 472         struct flowi fl;
 473         int err = -1;
 474
 475         memset(&fl, 0, sizeof(fl));
 476         fl.proto = IPPROTO_TCP;
 477         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 478         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
 479         fl.fl6_flowlabel = 0;
 480         fl.oif = treq->iif;
 481         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
 482         fl.fl_ip_sport = inet_sk(sk)->sport;
 483         security_req_classify_flow(req, &fl);
 484
 485         if (dst == NULL) {
 486                 opt = np->opt;
 487                 if (opt && opt->srcrt) {
 488                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
 489                         ipv6_addr_copy(&final, &fl.fl6_dst);
 490                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 491                         final_p = &final;
 492                 }
 493
 494                 err = ip6_dst_lookup(sk, &dst, &fl);
 495                 if (err)
 496                         goto done;
 497                 if (final_p)
 498                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 499                 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 500                         goto done;
 501         }
 502
 503         skb = tcp_make_synack(sk, dst, req);
 504         if (skb) {
 505                 struct tcphdr *th = tcp_hdr(skb);
 506
 507                 th->check = tcp_v6_check(th, skb->len,
 508                                          &treq->loc_addr, &treq->rmt_addr,
 509                                          csum_partial((char *)th, skb->len, skb->csum));
 510
 511                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 512                 err = ip6_xmit(sk, skb, &fl, opt, 0);
 513                 err = net_xmit_eval(err);
 514         }
 515
 516 done:
 517         if (opt && opt != np->opt)
 518                 sock_kfree_s(sk, opt, opt->tot_len);
 519         dst_release(dst);
 520         return err;
 521 }
 522
 523 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 524 {
 525         if (inet6_rsk(req)->pktopts)
 526                 kfree_skb(inet6_rsk(req)->pktopts);
 527 }
 528
 529 #ifdef CONFIG_TCP_MD5SIG
 530 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 531                                                    struct in6_addr *addr)
 532 {
 533         struct tcp_sock *tp = tcp_sk(sk);
 534         int i;
 535
 536         BUG_ON(tp == NULL);
 537
 538         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 539                 return NULL;
 540
 541         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 542                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, addr) == 0)
 543                         return (struct tcp_md5sig_key *)&tp->md5sig_info->keys6[i];
 544         }
 545         return NULL;
 546 }
 547
 548 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 549                                                 struct sock *addr_sk)
 550 {
 551         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 552 }
 553
 554 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 555                                                       struct request_sock *req)
 556 {
 557         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 558 }
 559
 560 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
 561                              char *newkey, u8 newkeylen)
 562 {
 563         /* Add key to the list */
 564         struct tcp6_md5sig_key *key;
 565         struct tcp_sock *tp = tcp_sk(sk);
 566         struct tcp6_md5sig_key *keys;
 567
 568         key = (struct tcp6_md5sig_key*) tcp_v6_md5_do_lookup(sk, peer);
 569         if (key) {
 570                 /* modify existing entry - just update that one */
 571                 kfree(key->key);
 572                 key->key = newkey;
 573                 key->keylen = newkeylen;
 574         } else {
 575                 /* reallocate new list if current one is full. */
 576                 if (!tp->md5sig_info) {
 577                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 578                         if (!tp->md5sig_info) {
 579                                 kfree(newkey);
 580                                 return -ENOMEM;
 581                         }
 582                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 583                 }
 584                 tcp_alloc_md5sig_pool();
 585                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 586                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 587                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 588
 589                         if (!keys) {
 590                                 tcp_free_md5sig_pool();
 591                                 kfree(newkey);
 592                                 return -ENOMEM;
 593                         }
 594
 595                         if (tp->md5sig_info->entries6)
 596                                 memmove(keys, tp->md5sig_info->keys6,
 597                                         (sizeof (tp->md5sig_info->keys6[0]) *
 598                                          tp->md5sig_info->entries6));
 599
 600                         kfree(tp->md5sig_info->keys6);
 601                         tp->md5sig_info->keys6 = keys;
 602                         tp->md5sig_info->alloced6++;
 603                 }
 604
 605                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 606                                peer);
 607                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].key = newkey;
 608                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].keylen = newkeylen;
 609
 610                 tp->md5sig_info->entries6++;
 611         }
 612         return 0;
 613 }
 614
 615 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 616                                u8 *newkey, __u8 newkeylen)
 617 {
 618         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 619                                  newkey, newkeylen);
 620 }
 621
 622 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 623 {
 624         struct tcp_sock *tp = tcp_sk(sk);
 625         int i;
 626
 627         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 628                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, peer) == 0) {
 629                         /* Free the key */
 630                         kfree(tp->md5sig_info->keys6[i].key);
 631                         tp->md5sig_info->entries6--;
 632
 633                         if (tp->md5sig_info->entries6 == 0) {
 634                                 kfree(tp->md5sig_info->keys6);
 635                                 tp->md5sig_info->keys6 = NULL;
 636
 637                                 tcp_free_md5sig_pool();
 638
 639                                 return 0;
 640                         } else {
 641                                 /* shrink the database */
 642                                 if (tp->md5sig_info->entries6 != i)
 643                                         memmove(&tp->md5sig_info->keys6[i],
 644                                                 &tp->md5sig_info->keys6[i+1],
 645                                                 (tp->md5sig_info->entries6 - i)
 646                                                 * sizeof (tp->md5sig_info->keys6[0]));
 647                         }
 648                 }
 649         }
 650         return -ENOENT;
 651 }
 652
 653 static void tcp_v6_clear_md5_list (struct sock *sk)
 654 {
 655         struct tcp_sock *tp = tcp_sk(sk);
 656         int i;
 657
 658         if (tp->md5sig_info->entries6) {
 659                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 660                         kfree(tp->md5sig_info->keys6[i].key);
 661                 tp->md5sig_info->entries6 = 0;
 662                 tcp_free_md5sig_pool();
 663         }
 664
 665         kfree(tp->md5sig_info->keys6);
 666         tp->md5sig_info->keys6 = NULL;
 667         tp->md5sig_info->alloced6 = 0;
 668
 669         if (tp->md5sig_info->entries4) {
 670                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 671                         kfree(tp->md5sig_info->keys4[i].key);
 672                 tp->md5sig_info->entries4 = 0;
 673                 tcp_free_md5sig_pool();
 674         }
 675
 676         kfree(tp->md5sig_info->keys4);
 677         tp->md5sig_info->keys4 = NULL;
 678         tp->md5sig_info->alloced4 = 0;
 679 }
 680
 681 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 682                                   int optlen)
 683 {
 684         struct tcp_md5sig cmd;
 685         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 686         u8 *newkey;
 687
 688         if (optlen < sizeof(cmd))
 689                 return -EINVAL;
 690
 691         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 692                 return -EFAULT;
 693
 694         if (sin6->sin6_family != AF_INET6)
 695                 return -EINVAL;
 696
 697         if (!cmd.tcpm_keylen) {
 698                 if (!tcp_sk(sk)->md5sig_info)
 699                         return -ENOENT;
 700                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 701                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 702                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 703         }
 704
 705         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 706                 return -EINVAL;
 707
 708         if (!tcp_sk(sk)->md5sig_info) {
 709                 struct tcp_sock *tp = tcp_sk(sk);
 710                 struct tcp_md5sig_info *p;
 711
 712                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 713                 if (!p)
 714                         return -ENOMEM;
 715
 716                 tp->md5sig_info = p;
 717                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 718         }
 719
 720         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 721         if (!newkey)
 722                 return -ENOMEM;
 723         if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED) {
 724                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 725                                          newkey, cmd.tcpm_keylen);
 726         }
 727         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 728 }
 729
 730 static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 731                                    struct in6_addr *saddr,
 732                                    struct in6_addr *daddr,
 733                                    struct tcphdr *th, int protocol,
 734                                    int tcplen)
 735 {
 736         struct scatterlist sg[4];
 737         __u16 data_len;
 738         int block = 0;
 739         __sum16 cksum;
 740         struct tcp_md5sig_pool *hp;
 741         struct tcp6_pseudohdr *bp;
 742         struct hash_desc *desc;
 743         int err;
 744         unsigned int nbytes = 0;
 745
 746         hp = tcp_get_md5sig_pool();
 747         if (!hp) {
 748                 printk(KERN_WARNING "%s(): hash pool not found...\n", __FUNCTION__);
 749                 goto clear_hash_noput;
 750         }
 751         bp = &hp->md5_blk.ip6;
 752         desc = &hp->md5_desc;
 753
 754         /* 1. TCP pseudo-header (RFC2460) */
 755         ipv6_addr_copy(&bp->saddr, saddr);
 756         ipv6_addr_copy(&bp->daddr, daddr);
 757         bp->len = htonl(tcplen);
 758         bp->protocol = htonl(protocol);
 759
 760         sg_set_buf(&sg[block++], bp, sizeof(*bp));
 761         nbytes += sizeof(*bp);
 762
 763         /* 2. TCP header, excluding options */
 764         cksum = th->check;
 765         th->check = 0;
 766         sg_set_buf(&sg[block++], th, sizeof(*th));
 767         nbytes += sizeof(*th);
 768
 769         /* 3. TCP segment data (if any) */
 770         data_len = tcplen - (th->doff << 2);
 771         if (data_len > 0) {
 772                 u8 *data = (u8 *)th + (th->doff << 2);
 773                 sg_set_buf(&sg[block++], data, data_len);
 774                 nbytes += data_len;
 775         }
 776
 777         /* 4. shared key */
 778         sg_set_buf(&sg[block++], key->key, key->keylen);
 779         nbytes += key->keylen;
 780
 781         /* Now store the hash into the packet */
 782         err = crypto_hash_init(desc);
 783         if (err) {
 784                 printk(KERN_WARNING "%s(): hash_init failed\n", __FUNCTION__);
 785                 goto clear_hash;
 786         }
 787         err = crypto_hash_update(desc, sg, nbytes);
 788         if (err) {
 789                 printk(KERN_WARNING "%s(): hash_update failed\n", __FUNCTION__);
 790                 goto clear_hash;
 791         }
 792         err = crypto_hash_final(desc, md5_hash);
 793         if (err) {
 794                 printk(KERN_WARNING "%s(): hash_final failed\n", __FUNCTION__);
 795                 goto clear_hash;
 796         }
 797
 798         /* Reset header, and free up the crypto */
 799         tcp_put_md5sig_pool();
 800         th->check = cksum;
 801 out:
 802         return 0;
 803 clear_hash:
 804         tcp_put_md5sig_pool();
 805 clear_hash_noput:
 806         memset(md5_hash, 0, 16);
 807         goto out;
 808 }
 809
 810 static int tcp_v6_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 811                                 struct sock *sk,
 812                                 struct dst_entry *dst,
 813                                 struct request_sock *req,
 814                                 struct tcphdr *th, int protocol,
 815                                 int tcplen)
 816 {
 817         struct in6_addr *saddr, *daddr;
 818
 819         if (sk) {
 820                 saddr = &inet6_sk(sk)->saddr;
 821                 daddr = &inet6_sk(sk)->daddr;
 822         } else {
 823                 saddr = &inet6_rsk(req)->loc_addr;
 824                 daddr = &inet6_rsk(req)->rmt_addr;
 825         }
 826         return tcp_v6_do_calc_md5_hash(md5_hash, key,
 827                                        saddr, daddr,
 828                                        th, protocol, tcplen);
 829 }
 830
 831 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 832 {
 833         __u8 *hash_location = NULL;
 834         struct tcp_md5sig_key *hash_expected;
 835         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 836         struct tcphdr *th = tcp_hdr(skb);
 837         int length = (th->doff << 2) - sizeof (*th);
 838         int genhash;
 839         u8 *ptr;
 840         u8 newhash[16];
 841
 842         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 843
 844         /* If the TCP option is too short, we can short cut */
 845         if (length < TCPOLEN_MD5SIG)
 846                 return hash_expected ? 1 : 0;
 847
 848         /* parse options */
 849         ptr = (u8*)(th + 1);
 850         while (length > 0) {
 851                 int opcode = *ptr++;
 852                 int opsize;
 853
 854                 switch(opcode) {
 855                 case TCPOPT_EOL:
 856                         goto done_opts;
 857                 case TCPOPT_NOP:
 858                         length--;
 859                         continue;
 860                 default:
 861                         opsize = *ptr++;
 862                         if (opsize < 2 || opsize > length)
 863                                 goto done_opts;
 864                         if (opcode == TCPOPT_MD5SIG) {
 865                                 hash_location = ptr;
 866                                 goto done_opts;
 867                         }
 868                 }
 869                 ptr += opsize - 2;
 870                 length -= opsize;
 871         }
 872
 873 done_opts:
 874         /* do we have a hash as expected? */
 875         if (!hash_expected) {
 876                 if (!hash_location)
 877                         return 0;
 878                 if (net_ratelimit()) {
 879                         printk(KERN_INFO "MD5 Hash NOT expected but found "
 880                                "(" NIP6_FMT ", %u)->"
 881                                "(" NIP6_FMT ", %u)\n",
 882                                NIP6(ip6h->saddr), ntohs(th->source),
 883                                NIP6(ip6h->daddr), ntohs(th->dest));
 884                 }
 885                 return 1;
 886         }
 887
 888         if (!hash_location) {
 889                 if (net_ratelimit()) {
 890                         printk(KERN_INFO "MD5 Hash expected but NOT found "
 891                                "(" NIP6_FMT ", %u)->"
 892                                "(" NIP6_FMT ", %u)\n",
 893                                NIP6(ip6h->saddr), ntohs(th->source),
 894                                NIP6(ip6h->daddr), ntohs(th->dest));
 895                 }
 896                 return 1;
 897         }
 898
 899         /* check the signature */
 900         genhash = tcp_v6_do_calc_md5_hash(newhash,
 901                                           hash_expected,
 902                                           &ip6h->saddr, &ip6h->daddr,
 903                                           th, sk->sk_protocol,
 904                                           skb->len);
 905         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 906                 if (net_ratelimit()) {
 907                         printk(KERN_INFO "MD5 Hash %s for "
 908                                "(" NIP6_FMT ", %u)->"
 909                                "(" NIP6_FMT ", %u)\n",
 910                                genhash ? "failed" : "mismatch",
 911                                NIP6(ip6h->saddr), ntohs(th->source),
 912                                NIP6(ip6h->daddr), ntohs(th->dest));
 913                 }
 914                 return 1;
 915         }
 916         return 0;
 917 }
 918 #endif
 919
 920 static struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 921         .family         =       AF_INET6,
 922         .obj_size       =       sizeof(struct tcp6_request_sock),
 923         .rtx_syn_ack    =       tcp_v6_send_synack,
 924         .send_ack       =       tcp_v6_reqsk_send_ack,
 925         .destructor     =       tcp_v6_reqsk_destructor,
 926         .send_reset     =       tcp_v6_send_reset
 927 };
 928
 929 #ifdef CONFIG_TCP_MD5SIG
 930 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 931         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 932 };
 933 #endif
 934
 935 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 936         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 937         .twsk_unique    = tcp_twsk_unique,
 938         .twsk_destructor= tcp_twsk_destructor,
 939 };
 940
 941 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 942 {
 943         struct ipv6_pinfo *np = inet6_sk(sk);
 944         struct tcphdr *th = tcp_hdr(skb);
 945
 946         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 947                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 948                 skb->csum_start = skb_transport_header(skb) - skb->head;
 949                 skb->csum_offset = offsetof(struct tcphdr, check);
 950         } else {
 951                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 952                                             csum_partial((char *)th, th->doff<<2,
 953                                                          skb->csum));
 954         }
 955 }
 956
 957 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 958 {
 959         struct ipv6hdr *ipv6h;
 960         struct tcphdr *th;
 961
 962         if (!pskb_may_pull(skb, sizeof(*th)))
 963                 return -EINVAL;
 964
 965         ipv6h = ipv6_hdr(skb);
 966         th = tcp_hdr(skb);
 967
 968         th->check = 0;
 969         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 970                                      IPPROTO_TCP, 0);
 971         skb->csum_start = skb_transport_header(skb) - skb->head;
 972         skb->csum_offset = offsetof(struct tcphdr, check);
 973         skb->ip_summed = CHECKSUM_PARTIAL;
 974         return 0;
 975 }
 976
 977 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 978 {
 979         struct tcphdr *th = tcp_hdr(skb), *t1;
 980         struct sk_buff *buff;
 981         struct flowi fl;
 982         int tot_len = sizeof(*th);
 983 #ifdef CONFIG_TCP_MD5SIG
 984         struct tcp_md5sig_key *key;
 985 #endif
 986
 987         if (th->rst)
 988                 return;
 989
 990         if (!ipv6_unicast_destination(skb))
 991                 return;
 992
 993 #ifdef CONFIG_TCP_MD5SIG
 994         if (sk)
 995                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
 996         else
 997                 key = NULL;
 998
 999         if (key)
1000                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1001 #endif
1002
1003         /*
1004          * We need to grab some memory, and put together an RST,
1005          * and then put it into the queue to be sent.
1006          */
1007
1008         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1009                          GFP_ATOMIC);
1010         if (buff == NULL)
1011                 return;
1012
1013         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1014
1015         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1016
1017         /* Swap the send and the receive. */
1018         memset(t1, 0, sizeof(*t1));
1019         t1->dest = th->source;
1020         t1->source = th->dest;
1021         t1->doff = tot_len / 4;
1022         t1->rst = 1;
1023
1024         if(th->ack) {
1025                 t1->seq = th->ack_seq;
1026         } else {
1027                 t1->ack = 1;
1028                 t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
1029                                     + skb->len - (th->doff<<2));
1030         }
1031
1032 #ifdef CONFIG_TCP_MD5SIG
1033         if (key) {
1034                 __be32 *opt = (__be32*)(t1 + 1);
1035                 opt[0] = htonl((TCPOPT_NOP << 24) |
1036                                (TCPOPT_NOP << 16) |
1037                                (TCPOPT_MD5SIG << 8) |
1038                                TCPOLEN_MD5SIG);
1039                 tcp_v6_do_calc_md5_hash((__u8 *)&opt[1], key,
1040                                         &ipv6_hdr(skb)->daddr,
1041                                         &ipv6_hdr(skb)->saddr,
1042                                         t1, IPPROTO_TCP, tot_len);
1043         }
1044 #endif
1045
1046         buff->csum = csum_partial((char *)t1, sizeof(*t1), 0);
1047
1048         memset(&fl, 0, sizeof(fl));
1049         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1050         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1051
1052         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1053                                     sizeof(*t1), IPPROTO_TCP,
1054                                     buff->csum);
1055
1056         fl.proto = IPPROTO_TCP;
1057         fl.oif = inet6_iif(skb);
1058         fl.fl_ip_dport = t1->dest;
1059         fl.fl_ip_sport = t1->source;
1060         security_skb_classify_flow(skb, &fl);
1061
1062         /* sk = NULL, but it is safe for now. RST socket required. */
1063         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1064
1065                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1066                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1067                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1068                         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
1069                         return;
1070                 }
1071         }
1072
1073         kfree_skb(buff);
1074 }
1075
1076 static void tcp_v6_send_ack(struct tcp_timewait_sock *tw,
1077                             struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
1078 {
1079         struct tcphdr *th = tcp_hdr(skb), *t1;
1080         struct sk_buff *buff;
1081         struct flowi fl;
1082         int tot_len = sizeof(struct tcphdr);
1083         __be32 *topt;
1084 #ifdef CONFIG_TCP_MD5SIG
1085         struct tcp_md5sig_key *key;
1086         struct tcp_md5sig_key tw_key;
1087 #endif
1088
1089 #ifdef CONFIG_TCP_MD5SIG
1090         if (!tw && skb->sk) {
1091                 key = tcp_v6_md5_do_lookup(skb->sk, &ipv6_hdr(skb)->daddr);
1092         } else if (tw && tw->tw_md5_keylen) {
1093                 tw_key.key = tw->tw_md5_key;
1094                 tw_key.keylen = tw->tw_md5_keylen;
1095                 key = &tw_key;
1096         } else {
1097                 key = NULL;
1098         }
1099 #endif
1100
1101         if (ts)
1102                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1103 #ifdef CONFIG_TCP_MD5SIG
1104         if (key)
1105                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1106 #endif
1107
1108         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1109                          GFP_ATOMIC);
1110         if (buff == NULL)
1111                 return;
1112
1113         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1114
1115         t1 = (struct tcphdr *) skb_push(buff,tot_len);
1116
1117         /* Swap the send and the receive. */
1118         memset(t1, 0, sizeof(*t1));
1119         t1->dest = th->source;
1120         t1->source = th->dest;
1121         t1->doff = tot_len/4;
1122         t1->seq = htonl(seq);
1123         t1->ack_seq = htonl(ack);
1124         t1->ack = 1;
1125         t1->window = htons(win);
1126
1127         topt = (__be32 *)(t1 + 1);
1128
1129         if (ts) {
1130                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1131                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1132                 *topt++ = htonl(tcp_time_stamp);
1133                 *topt = htonl(ts);
1134         }
1135
1136 #ifdef CONFIG_TCP_MD5SIG
1137         if (key) {
1138                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1139                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1140                 tcp_v6_do_calc_md5_hash((__u8 *)topt, key,
1141                                         &ipv6_hdr(skb)->daddr,
1142                                         &ipv6_hdr(skb)->saddr,
1143                                         t1, IPPROTO_TCP, tot_len);
1144         }
1145 #endif
1146
1147         buff->csum = csum_partial((char *)t1, tot_len, 0);
1148
1149         memset(&fl, 0, sizeof(fl));
1150         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1151         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1152
1153         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1154                                     tot_len, IPPROTO_TCP,
1155                                     buff->csum);
1156
1157         fl.proto = IPPROTO_TCP;
1158         fl.oif = inet6_iif(skb);
1159         fl.fl_ip_dport = t1->dest;
1160         fl.fl_ip_sport = t1->source;
1161         security_skb_classify_flow(skb, &fl);
1162
1163         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1164                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1165                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1166                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1167                         return;
1168                 }
1169         }
1170
1171         kfree_skb(buff);
1172 }
1173
1174 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1175 {
1176         struct inet_timewait_sock *tw = inet_twsk(sk);
1177         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1178
1179         tcp_v6_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1180                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1181                         tcptw->tw_ts_recent);
1182
1183         inet_twsk_put(tw);
1184 }
1185
1186 static void tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
1187 {
1188         tcp_v6_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent);
1189 }
1190
1191
1192 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1193 {
1194         struct request_sock *req, **prev;
1195         const struct tcphdr *th = tcp_hdr(skb);
1196         struct sock *nsk;
1197
1198         /* Find possible connection requests. */
1199         req = inet6_csk_search_req(sk, &prev, th->source,
1200                                    &ipv6_hdr(skb)->saddr,
1201                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1202         if (req)
1203                 return tcp_check_req(sk, skb, req, prev);
1204
1205         nsk = __inet6_lookup_established(&tcp_hashinfo, &ipv6_hdr(skb)->saddr,
1206                                          th->source, &ipv6_hdr(skb)->daddr,
1207                                          ntohs(th->dest), inet6_iif(skb));
1208
1209         if (nsk) {
1210                 if (nsk->sk_state != TCP_TIME_WAIT) {
1211                         bh_lock_sock(nsk);
1212                         return nsk;
1213                 }
1214                 inet_twsk_put(inet_twsk(nsk));
1215                 return NULL;
1216         }
1217
1218 #if 0 /*def CONFIG_SYN_COOKIES*/
1219         if (!th->rst && !th->syn && th->ack)
1220                 sk = cookie_v6_check(sk, skb, &(IPCB(skb)->opt));
1221 #endif
1222         return sk;
1223 }
1224
1225 /* FIXME: this is substantially similar to the ipv4 code.
1226  * Can some kind of merge be done? -- erics
1227  */
1228 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1229 {
1230         struct inet6_request_sock *treq;
1231         struct ipv6_pinfo *np = inet6_sk(sk);
1232         struct tcp_options_received tmp_opt;
1233         struct tcp_sock *tp = tcp_sk(sk);
1234         struct request_sock *req = NULL;
1235         __u32 isn = TCP_SKB_CB(skb)->when;
1236
1237         if (skb->protocol == htons(ETH_P_IP))
1238                 return tcp_v4_conn_request(sk, skb);
1239
1240         if (!ipv6_unicast_destination(skb))
1241                 goto drop;
1242
1243         /*
1244          *      There are no SYN attacks on IPv6, yet...
1245          */
1246         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1247                 if (net_ratelimit())
1248                         printk(KERN_INFO "TCPv6: dropping request, synflood is possible\n");
1249                 goto drop;
1250         }
1251
1252         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1253                 goto drop;
1254
1255         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1256         if (req == NULL)
1257                 goto drop;
1258
1259 #ifdef CONFIG_TCP_MD5SIG
1260         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1261 #endif
1262
1263         tcp_clear_options(&tmp_opt);
1264         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1265         tmp_opt.user_mss = tp->rx_opt.user_mss;
1266
1267         tcp_parse_options(skb, &tmp_opt, 0);
1268
1269         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1270         tcp_openreq_init(req, &tmp_opt, skb);
1271
1272         treq = inet6_rsk(req);
1273         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1274         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1275         TCP_ECN_create_request(req, tcp_hdr(skb));
1276         treq->pktopts = NULL;
1277         if (ipv6_opt_accepted(sk, skb) ||
1278             np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1279             np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1280                 atomic_inc(&skb->users);
1281                 treq->pktopts = skb;
1282         }
1283         treq->iif = sk->sk_bound_dev_if;
1284
1285         /* So that link locals have meaning */
1286         if (!sk->sk_bound_dev_if &&
1287             ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1288                 treq->iif = inet6_iif(skb);
1289
1290         if (isn == 0)
1291                 isn = tcp_v6_init_sequence(skb);
1292
1293         tcp_rsk(req)->snt_isn = isn;
1294
1295         security_inet_conn_request(sk, skb, req);
1296
1297         if (tcp_v6_send_synack(sk, req, NULL))
1298                 goto drop;
1299
1300         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1301         return 0;
1302
1303 drop:
1304         if (req)
1305                 reqsk_free(req);
1306
1307         return 0; /* don't send reset */
1308 }
1309
1310 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1311                                           struct request_sock *req,
1312                                           struct dst_entry *dst)
1313 {
1314         struct inet6_request_sock *treq = inet6_rsk(req);
1315         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1316         struct tcp6_sock *newtcp6sk;
1317         struct inet_sock *newinet;
1318         struct tcp_sock *newtp;
1319         struct sock *newsk;
1320         struct ipv6_txoptions *opt;
1321 #ifdef CONFIG_TCP_MD5SIG
1322         struct tcp_md5sig_key *key;
1323 #endif
1324
1325         if (skb->protocol == htons(ETH_P_IP)) {
1326                 /*
1327                  *      v6 mapped
1328                  */
1329
1330                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1331
1332                 if (newsk == NULL)
1333                         return NULL;
1334
1335                 newtcp6sk = (struct tcp6_sock *)newsk;
1336                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1337
1338                 newinet = inet_sk(newsk);
1339                 newnp = inet6_sk(newsk);
1340                 newtp = tcp_sk(newsk);
1341
1342                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1343
1344                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1345                               newinet->daddr);
1346
1347                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1348                               newinet->saddr);
1349
1350                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1351
1352                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1353                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1354 #ifdef CONFIG_TCP_MD5SIG
1355                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1356 #endif
1357
1358                 newnp->pktoptions  = NULL;
1359                 newnp->opt         = NULL;
1360                 newnp->mcast_oif   = inet6_iif(skb);
1361                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1362
1363                 /*
1364                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1365                  * here, tcp_create_openreq_child now does this for us, see the comment in
1366                  * that function for the gory details. -acme
1367                  */
1368
1369                 /* It is tricky place. Until this moment IPv4 tcp
1370                    worked with IPv6 icsk.icsk_af_ops.
1371                    Sync it now.
1372                  */
1373                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1374
1375                 return newsk;
1376         }
1377
1378         opt = np->opt;
1379
1380         if (sk_acceptq_is_full(sk))
1381                 goto out_overflow;
1382
1383         if (dst == NULL) {
1384                 struct in6_addr *final_p = NULL, final;
1385                 struct flowi fl;
1386
1387                 memset(&fl, 0, sizeof(fl));
1388                 fl.proto = IPPROTO_TCP;
1389                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1390                 if (opt && opt->srcrt) {
1391                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1392                         ipv6_addr_copy(&final, &fl.fl6_dst);
1393                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1394                         final_p = &final;
1395                 }
1396                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1397                 fl.oif = sk->sk_bound_dev_if;
1398                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1399                 fl.fl_ip_sport = inet_sk(sk)->sport;
1400                 security_req_classify_flow(req, &fl);
1401
1402                 if (ip6_dst_lookup(sk, &dst, &fl))
1403                         goto out;
1404
1405                 if (final_p)
1406                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1407
1408                 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
1409                         goto out;
1410         }
1411
1412         newsk = tcp_create_openreq_child(sk, req, skb);
1413         if (newsk == NULL)
1414                 goto out;
1415
1416         /*
1417          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1418          * count here, tcp_create_openreq_child now does this for us, see the
1419          * comment in that function for the gory details. -acme
1420          */
1421
1422         newsk->sk_gso_type = SKB_GSO_TCPV6;
1423         __ip6_dst_store(newsk, dst, NULL, NULL);
1424
1425         newtcp6sk = (struct tcp6_sock *)newsk;
1426         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1427
1428         newtp = tcp_sk(newsk);
1429         newinet = inet_sk(newsk);
1430         newnp = inet6_sk(newsk);
1431
1432         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1433
1434         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1435         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1436         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1437         newsk->sk_bound_dev_if = treq->iif;
1438
1439         /* Now IPv6 options...
1440
1441            First: no IPv4 options.
1442          */
1443         newinet->opt = NULL;
1444         newnp->ipv6_fl_list = NULL;
1445
1446         /* Clone RX bits */
1447         newnp->rxopt.all = np->rxopt.all;
1448
1449         /* Clone pktoptions received with SYN */
1450         newnp->pktoptions = NULL;
1451         if (treq->pktopts != NULL) {
1452                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1453                 kfree_skb(treq->pktopts);
1454                 treq->pktopts = NULL;
1455                 if (newnp->pktoptions)
1456                         skb_set_owner_r(newnp->pktoptions, newsk);
1457         }
1458         newnp->opt        = NULL;
1459         newnp->mcast_oif  = inet6_iif(skb);
1460         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1461
1462         /* Clone native IPv6 options from listening socket (if any)
1463
1464            Yes, keeping reference count would be much more clever,
1465            but we make one more one thing there: reattach optmem
1466            to newsk.
1467          */
1468         if (opt) {
1469                 newnp->opt = ipv6_dup_options(newsk, opt);
1470                 if (opt != np->opt)
1471                         sock_kfree_s(sk, opt, opt->tot_len);
1472         }
1473
1474         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1475         if (newnp->opt)
1476                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1477                                                      newnp->opt->opt_flen);
1478
1479         tcp_mtup_init(newsk);
1480         tcp_sync_mss(newsk, dst_mtu(dst));
1481         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1482         tcp_initialize_rcv_mss(newsk);
1483
1484         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1485
1486 #ifdef CONFIG_TCP_MD5SIG
1487         /* Copy over the MD5 key from the original socket */
1488         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1489                 /* We're using one, so create a matching key
1490                  * on the newsk structure. If we fail to get
1491                  * memory, then we end up not copying the key
1492                  * across. Shucks.
1493                  */
1494                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1495                 if (newkey != NULL)
1496                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1497                                           newkey, key->keylen);
1498         }
1499 #endif
1500
1501         __inet6_hash(&tcp_hashinfo, newsk);
1502         inet_inherit_port(&tcp_hashinfo, sk, newsk);
1503
1504         return newsk;
1505
1506 out_overflow:
1507         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
1508 out:
1509         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
1510         if (opt && opt != np->opt)
1511                 sock_kfree_s(sk, opt, opt->tot_len);
1512         dst_release(dst);
1513         return NULL;
1514 }
1515
1516 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1517 {
1518         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1519                 if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1520                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1521                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1522                         return 0;
1523                 }
1524         }
1525
1526         skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1527                                               &ipv6_hdr(skb)->saddr,
1528                                               &ipv6_hdr(skb)->daddr, 0));
1529
1530         if (skb->len <= 76) {
1531                 return __skb_checksum_complete(skb);
1532         }
1533         return 0;
1534 }
1535
1536 /* The socket must have it's spinlock held when we get
1537  * here.
1538  *
1539  * We have a potential double-lock case here, so even when
1540  * doing backlog processing we use the BH locking scheme.
1541  * This is because we cannot sleep with the original spinlock
1542  * held.
1543  */
1544 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1545 {
1546         struct ipv6_pinfo *np = inet6_sk(sk);
1547         struct tcp_sock *tp;
1548         struct sk_buff *opt_skb = NULL;
1549
1550         /* Imagine: socket is IPv6. IPv4 packet arrives,
1551            goes to IPv4 receive handler and backlogged.
1552            From backlog it always goes here. Kerboom...
1553            Fortunately, tcp_rcv_established and rcv_established
1554            handle them correctly, but it is not case with
1555            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1556          */
1557
1558         if (skb->protocol == htons(ETH_P_IP))
1559                 return tcp_v4_do_rcv(sk, skb);
1560
1561 #ifdef CONFIG_TCP_MD5SIG
1562         if (tcp_v6_inbound_md5_hash (sk, skb))
1563                 goto discard;
1564 #endif
1565
1566         if (sk_filter(sk, skb))
1567                 goto discard;
1568
1569         /*
1570          *      socket locking is here for SMP purposes as backlog rcv
1571          *      is currently called with bh processing disabled.
1572          */
1573
1574         /* Do Stevens' IPV6_PKTOPTIONS.
1575
1576            Yes, guys, it is the only place in our code, where we
1577            may make it not affecting IPv4.
1578            The rest of code is protocol independent,
1579            and I do not like idea to uglify IPv4.
1580
1581            Actually, all the idea behind IPV6_PKTOPTIONS
1582            looks not very well thought. For now we latch
1583            options, received in the last packet, enqueued
1584            by tcp. Feel free to propose better solution.
1585                                                --ANK (980728)
1586          */
1587         if (np->rxopt.all)
1588                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1589
1590         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1591                 TCP_CHECK_TIMER(sk);
1592                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1593                         goto reset;
1594                 TCP_CHECK_TIMER(sk);
1595                 if (opt_skb)
1596                         goto ipv6_pktoptions;
1597                 return 0;
1598         }
1599
1600         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1601                 goto csum_err;
1602
1603         if (sk->sk_state == TCP_LISTEN) {
1604                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1605                 if (!nsk)
1606                         goto discard;
1607
1608                 /*
1609                  * Queue it on the new socket if the new socket is active,
1610                  * otherwise we just shortcircuit this and continue with
1611                  * the new socket..
1612                  */
1613                 if(nsk != sk) {
1614                         if (tcp_child_process(sk, nsk, skb))
1615                                 goto reset;
1616                         if (opt_skb)
1617                                 __kfree_skb(opt_skb);
1618                         return 0;
1619                 }
1620         }
1621
1622         TCP_CHECK_TIMER(sk);
1623         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1624                 goto reset;
1625         TCP_CHECK_TIMER(sk);
1626         if (opt_skb)
1627                 goto ipv6_pktoptions;
1628         return 0;
1629
1630 reset:
1631         tcp_v6_send_reset(sk, skb);
1632 discard:
1633         if (opt_skb)
1634                 __kfree_skb(opt_skb);
1635         kfree_skb(skb);
1636         return 0;
1637 csum_err:
1638         TCP_INC_STATS_BH(TCP_MIB_INERRS);
1639         goto discard;
1640
1641
1642 ipv6_pktoptions:
1643         /* Do you ask, what is it?
1644
1645            1. skb was enqueued by tcp.
1646            2. skb is added to tail of read queue, rather than out of order.
1647            3. socket is not in passive state.
1648            4. Finally, it really contains options, which user wants to receive.
1649          */
1650         tp = tcp_sk(sk);
1651         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1652             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1653                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1654                         np->mcast_oif = inet6_iif(opt_skb);
1655                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1656                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1657                 if (ipv6_opt_accepted(sk, opt_skb)) {
1658                         skb_set_owner_r(opt_skb, sk);
1659                         opt_skb = xchg(&np->pktoptions, opt_skb);
1660                 } else {
1661                         __kfree_skb(opt_skb);
1662                         opt_skb = xchg(&np->pktoptions, NULL);
1663                 }
1664         }
1665
1666         if (opt_skb)
1667                 kfree_skb(opt_skb);
1668         return 0;
1669 }
1670
1671 static int tcp_v6_rcv(struct sk_buff **pskb)
1672 {
1673         struct sk_buff *skb = *pskb;
1674         struct tcphdr *th;
1675         struct sock *sk;
1676         int ret;
1677
1678         if (skb->pkt_type != PACKET_HOST)
1679                 goto discard_it;
1680
1681         /*
1682          *      Count it even if it's bad.
1683          */
1684         TCP_INC_STATS_BH(TCP_MIB_INSEGS);
1685
1686         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1687                 goto discard_it;
1688
1689         th = tcp_hdr(skb);
1690
1691         if (th->doff < sizeof(struct tcphdr)/4)
1692                 goto bad_packet;
1693         if (!pskb_may_pull(skb, th->doff*4))
1694                 goto discard_it;
1695
1696         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1697                 goto bad_packet;
1698
1699         th = tcp_hdr(skb);
1700         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1701         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1702                                     skb->len - th->doff*4);
1703         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1704         TCP_SKB_CB(skb)->when = 0;
1705         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1706         TCP_SKB_CB(skb)->sacked = 0;
1707
1708         sk = __inet6_lookup(&tcp_hashinfo, &ipv6_hdr(skb)->saddr, th->source,
1709                             &ipv6_hdr(skb)->daddr, ntohs(th->dest),
1710                             inet6_iif(skb));
1711
1712         if (!sk)
1713                 goto no_tcp_socket;
1714
1715 process:
1716         if (sk->sk_state == TCP_TIME_WAIT)
1717                 goto do_time_wait;
1718
1719         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1720                 goto discard_and_relse;
1721
1722         if (sk_filter(sk, skb))
1723                 goto discard_and_relse;
1724
1725         skb->dev = NULL;
1726
1727         bh_lock_sock_nested(sk);
1728         ret = 0;
1729         if (!sock_owned_by_user(sk)) {
1730 #ifdef CONFIG_NET_DMA
1731                 struct tcp_sock *tp = tcp_sk(sk);
1732                 if (tp->ucopy.dma_chan)
1733                         ret = tcp_v6_do_rcv(sk, skb);
1734                 else
1735 #endif
1736                 {
1737                         if (!tcp_prequeue(sk, skb))
1738                                 ret = tcp_v6_do_rcv(sk, skb);
1739                 }
1740         } else
1741                 sk_add_backlog(sk, skb);
1742         bh_unlock_sock(sk);
1743
1744         sock_put(sk);
1745         return ret ? -1 : 0;
1746
1747 no_tcp_socket:
1748         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1749                 goto discard_it;
1750
1751         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1752 bad_packet:
1753                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1754         } else {
1755                 tcp_v6_send_reset(NULL, skb);
1756         }
1757
1758 discard_it:
1759
1760         /*
1761          *      Discard frame
1762          */
1763
1764         kfree_skb(skb);
1765         return 0;
1766
1767 discard_and_relse:
1768         sock_put(sk);
1769         goto discard_it;
1770
1771 do_time_wait:
1772         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1773                 inet_twsk_put(inet_twsk(sk));
1774                 goto discard_it;
1775         }
1776
1777         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1778                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1779                 inet_twsk_put(inet_twsk(sk));
1780                 goto discard_it;
1781         }
1782
1783         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1784         case TCP_TW_SYN:
1785         {
1786                 struct sock *sk2;
1787
1788                 sk2 = inet6_lookup_listener(&tcp_hashinfo,
1789                                             &ipv6_hdr(skb)->daddr,
1790                                             ntohs(th->dest), inet6_iif(skb));
1791                 if (sk2 != NULL) {
1792                         struct inet_timewait_sock *tw = inet_twsk(sk);
1793                         inet_twsk_deschedule(tw, &tcp_death_row);
1794                         inet_twsk_put(tw);
1795                         sk = sk2;
1796                         goto process;
1797                 }
1798                 /* Fall through to ACK */
1799         }
1800         case TCP_TW_ACK:
1801                 tcp_v6_timewait_ack(sk, skb);
1802                 break;
1803         case TCP_TW_RST:
1804                 goto no_tcp_socket;
1805         case TCP_TW_SUCCESS:;
1806         }
1807         goto discard_it;
1808 }
1809
1810 static int tcp_v6_remember_stamp(struct sock *sk)
1811 {
1812         /* Alas, not yet... */
1813         return 0;
1814 }
1815
1816 static struct inet_connection_sock_af_ops ipv6_specific = {
1817         .queue_xmit        = inet6_csk_xmit,
1818         .send_check        = tcp_v6_send_check,
1819         .rebuild_header    = inet6_sk_rebuild_header,
1820         .conn_request      = tcp_v6_conn_request,
1821         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1822         .remember_stamp    = tcp_v6_remember_stamp,
1823         .net_header_len    = sizeof(struct ipv6hdr),
1824         .setsockopt        = ipv6_setsockopt,
1825         .getsockopt        = ipv6_getsockopt,
1826         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1827         .sockaddr_len      = sizeof(struct sockaddr_in6),
1828 #ifdef CONFIG_COMPAT
1829         .compat_setsockopt = compat_ipv6_setsockopt,
1830         .compat_getsockopt = compat_ipv6_getsockopt,
1831 #endif
1832 };
1833
1834 #ifdef CONFIG_TCP_MD5SIG
1835 static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1836         .md5_lookup     =       tcp_v6_md5_lookup,
1837         .calc_md5_hash  =       tcp_v6_calc_md5_hash,
1838         .md5_add        =       tcp_v6_md5_add_func,
1839         .md5_parse      =       tcp_v6_parse_md5_keys,
1840 };
1841 #endif
1842
1843 /*
1844  *      TCP over IPv4 via INET6 API
1845  */
1846
1847 static struct inet_connection_sock_af_ops ipv6_mapped = {
1848         .queue_xmit        = ip_queue_xmit,
1849         .send_check        = tcp_v4_send_check,
1850         .rebuild_header    = inet_sk_rebuild_header,
1851         .conn_request      = tcp_v6_conn_request,
1852         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1853         .remember_stamp    = tcp_v4_remember_stamp,
1854         .net_header_len    = sizeof(struct iphdr),
1855         .setsockopt        = ipv6_setsockopt,
1856         .getsockopt        = ipv6_getsockopt,
1857         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1858         .sockaddr_len      = sizeof(struct sockaddr_in6),
1859 #ifdef CONFIG_COMPAT
1860         .compat_setsockopt = compat_ipv6_setsockopt,
1861         .compat_getsockopt = compat_ipv6_getsockopt,
1862 #endif
1863 };
1864
1865 #ifdef CONFIG_TCP_MD5SIG
1866 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1867         .md5_lookup     =       tcp_v4_md5_lookup,
1868         .calc_md5_hash  =       tcp_v4_calc_md5_hash,
1869         .md5_add        =       tcp_v6_md5_add_func,
1870         .md5_parse      =       tcp_v6_parse_md5_keys,
1871 };
1872 #endif
1873
1874 /* NOTE: A lot of things set to zero explicitly by call to
1875  *       sk_alloc() so need not be done here.
1876  */
1877 static int tcp_v6_init_sock(struct sock *sk)
1878 {
1879         struct inet_connection_sock *icsk = inet_csk(sk);
1880         struct tcp_sock *tp = tcp_sk(sk);
1881
1882         skb_queue_head_init(&tp->out_of_order_queue);
1883         tcp_init_xmit_timers(sk);
1884         tcp_prequeue_init(tp);
1885
1886         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1887         tp->mdev = TCP_TIMEOUT_INIT;
1888
1889         /* So many TCP implementations out there (incorrectly) count the
1890          * initial SYN frame in their delayed-ACK and congestion control
1891          * algorithms that we must have the following bandaid to talk
1892          * efficiently to them.  -DaveM
1893          */
1894         tp->snd_cwnd = 2;
1895
1896         /* See draft-stevens-tcpca-spec-01 for discussion of the
1897          * initialization of these values.
1898          */
1899         tp->snd_ssthresh = 0x7fffffff;
1900         tp->snd_cwnd_clamp = ~0;
1901         tp->mss_cache = 536;
1902
1903         tp->reordering = sysctl_tcp_reordering;
1904
1905         sk->sk_state = TCP_CLOSE;
1906
1907         icsk->icsk_af_ops = &ipv6_specific;
1908         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1909         icsk->icsk_sync_mss = tcp_sync_mss;
1910         sk->sk_write_space = sk_stream_write_space;
1911         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1912
1913 #ifdef CONFIG_TCP_MD5SIG
1914         tp->af_specific = &tcp_sock_ipv6_specific;
1915 #endif
1916
1917         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1918         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1919
1920         atomic_inc(&tcp_sockets_allocated);
1921
1922         return 0;
1923 }
1924
1925 static int tcp_v6_destroy_sock(struct sock *sk)
1926 {
1927 #ifdef CONFIG_TCP_MD5SIG
1928         /* Clean up the MD5 key list */
1929         if (tcp_sk(sk)->md5sig_info)
1930                 tcp_v6_clear_md5_list(sk);
1931 #endif
1932         tcp_v4_destroy_sock(sk);
1933         return inet6_destroy_sock(sk);
1934 }
1935
1936 #ifdef CONFIG_PROC_FS
1937 /* Proc filesystem TCPv6 sock list dumping. */
1938 static void get_openreq6(struct seq_file *seq,
1939                          struct sock *sk, struct request_sock *req, int i, int uid)
1940 {
1941         int ttd = req->expires - jiffies;
1942         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1943         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1944
1945         if (ttd < 0)
1946                 ttd = 0;
1947
1948         seq_printf(seq,
1949                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1950                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1951                    i,
1952                    src->s6_addr32[0], src->s6_addr32[1],
1953                    src->s6_addr32[2], src->s6_addr32[3],
1954                    ntohs(inet_sk(sk)->sport),
1955                    dest->s6_addr32[0], dest->s6_addr32[1],
1956                    dest->s6_addr32[2], dest->s6_addr32[3],
1957                    ntohs(inet_rsk(req)->rmt_port),
1958                    TCP_SYN_RECV,
1959                    0,0, /* could print option size, but that is af dependent. */
1960                    1,   /* timers active (only the expire timer) */
1961                    jiffies_to_clock_t(ttd),
1962                    req->retrans,
1963                    uid,
1964                    0,  /* non standard timer */
1965                    0, /* open_requests have no inode */
1966                    0, req);
1967 }
1968
1969 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1970 {
1971         struct in6_addr *dest, *src;
1972         __u16 destp, srcp;
1973         int timer_active;
1974         unsigned long timer_expires;
1975         struct inet_sock *inet = inet_sk(sp);
1976         struct tcp_sock *tp = tcp_sk(sp);
1977         const struct inet_connection_sock *icsk = inet_csk(sp);
1978         struct ipv6_pinfo *np = inet6_sk(sp);
1979
1980         dest  = &np->daddr;
1981         src   = &np->rcv_saddr;
1982         destp = ntohs(inet->dport);
1983         srcp  = ntohs(inet->sport);
1984
1985         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1986                 timer_active    = 1;
1987                 timer_expires   = icsk->icsk_timeout;
1988         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1989                 timer_active    = 4;
1990                 timer_expires   = icsk->icsk_timeout;
1991         } else if (timer_pending(&sp->sk_timer)) {
1992                 timer_active    = 2;
1993                 timer_expires   = sp->sk_timer.expires;
1994         } else {
1995                 timer_active    = 0;
1996                 timer_expires = jiffies;
1997         }
1998
1999         seq_printf(seq,
2000                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2001                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d\n",
2002                    i,
2003                    src->s6_addr32[0], src->s6_addr32[1],
2004                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2005                    dest->s6_addr32[0], dest->s6_addr32[1],
2006                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2007                    sp->sk_state,
2008                    tp->write_seq-tp->snd_una,
2009                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2010                    timer_active,
2011                    jiffies_to_clock_t(timer_expires - jiffies),
2012                    icsk->icsk_retransmits,
2013                    sock_i_uid(sp),
2014                    icsk->icsk_probes_out,
2015                    sock_i_ino(sp),
2016                    atomic_read(&sp->sk_refcnt), sp,
2017                    icsk->icsk_rto,
2018                    icsk->icsk_ack.ato,
2019                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2020                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
2021                    );
2022 }
2023
2024 static void get_timewait6_sock(struct seq_file *seq,
2025                                struct inet_timewait_sock *tw, int i)
2026 {
2027         struct in6_addr *dest, *src;
2028         __u16 destp, srcp;
2029         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2030         int ttd = tw->tw_ttd - jiffies;
2031
2032         if (ttd < 0)
2033                 ttd = 0;
2034
2035         dest = &tw6->tw_v6_daddr;
2036         src  = &tw6->tw_v6_rcv_saddr;
2037         destp = ntohs(tw->tw_dport);
2038         srcp  = ntohs(tw->tw_sport);
2039
2040         seq_printf(seq,
2041                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2042                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2043                    i,
2044                    src->s6_addr32[0], src->s6_addr32[1],
2045                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2046                    dest->s6_addr32[0], dest->s6_addr32[1],
2047                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2048                    tw->tw_substate, 0, 0,
2049                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2050                    atomic_read(&tw->tw_refcnt), tw);
2051 }
2052
2053 static int tcp6_seq_show(struct seq_file *seq, void *v)
2054 {
2055         struct tcp_iter_state *st;
2056
2057         if (v == SEQ_START_TOKEN) {
2058                 seq_puts(seq,
2059                          "  sl  "
2060                          "local_address                         "
2061                          "remote_address                        "
2062                          "st tx_queue rx_queue tr tm->when retrnsmt"
2063                          "   uid  timeout inode\n");
2064                 goto out;
2065         }
2066         st = seq->private;
2067
2068         switch (st->state) {
2069         case TCP_SEQ_STATE_LISTENING:
2070         case TCP_SEQ_STATE_ESTABLISHED:
2071                 get_tcp6_sock(seq, v, st->num);
2072                 break;
2073         case TCP_SEQ_STATE_OPENREQ:
2074                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2075                 break;
2076         case TCP_SEQ_STATE_TIME_WAIT:
2077                 get_timewait6_sock(seq, v, st->num);
2078                 break;
2079         }
2080 out:
2081         return 0;
2082 }
2083
2084 static struct file_operations tcp6_seq_fops;
2085 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2086         .owner          = THIS_MODULE,
2087         .name           = "tcp6",
2088         .family         = AF_INET6,
2089         .seq_show       = tcp6_seq_show,
2090         .seq_fops       = &tcp6_seq_fops,
2091 };
2092
2093 int __init tcp6_proc_init(void)
2094 {
2095         return tcp_proc_register(&tcp6_seq_afinfo);
2096 }
2097
2098 void tcp6_proc_exit(void)
2099 {
2100         tcp_proc_unregister(&tcp6_seq_afinfo);
2101 }
2102 #endif
2103
2104 struct proto tcpv6_prot = {
2105         .name                   = "TCPv6",
2106         .owner                  = THIS_MODULE,
2107         .close                  = tcp_close,
2108         .connect                = tcp_v6_connect,
2109         .disconnect             = tcp_disconnect,
2110         .accept                 = inet_csk_accept,
2111         .ioctl                  = tcp_ioctl,
2112         .init                   = tcp_v6_init_sock,
2113         .destroy                = tcp_v6_destroy_sock,
2114         .shutdown               = tcp_shutdown,
2115         .setsockopt             = tcp_setsockopt,
2116         .getsockopt             = tcp_getsockopt,
2117         .sendmsg                = tcp_sendmsg,
2118         .recvmsg                = tcp_recvmsg,
2119         .backlog_rcv            = tcp_v6_do_rcv,
2120         .hash                   = tcp_v6_hash,
2121         .unhash                 = tcp_unhash,
2122         .get_port               = tcp_v6_get_port,
2123         .enter_memory_pressure  = tcp_enter_memory_pressure,
2124         .sockets_allocated      = &tcp_sockets_allocated,
2125         .memory_allocated       = &tcp_memory_allocated,
2126         .memory_pressure        = &tcp_memory_pressure,
2127         .orphan_count           = &tcp_orphan_count,
2128         .sysctl_mem             = sysctl_tcp_mem,
2129         .sysctl_wmem            = sysctl_tcp_wmem,
2130         .sysctl_rmem            = sysctl_tcp_rmem,
2131         .max_header             = MAX_TCP_HEADER,
2132         .obj_size               = sizeof(struct tcp6_sock),
2133         .twsk_prot              = &tcp6_timewait_sock_ops,
2134         .rsk_prot               = &tcp6_request_sock_ops,
2135 #ifdef CONFIG_COMPAT
2136         .compat_setsockopt      = compat_tcp_setsockopt,
2137         .compat_getsockopt      = compat_tcp_getsockopt,
2138 #endif
2139 };
2140
2141 static struct inet6_protocol tcpv6_protocol = {
2142         .handler        =       tcp_v6_rcv,
2143         .err_handler    =       tcp_v6_err,
2144         .gso_send_check =       tcp_v6_gso_send_check,
2145         .gso_segment    =       tcp_tso_segment,
2146         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2147 };
2148
2149 static struct inet_protosw tcpv6_protosw = {
2150         .type           =       SOCK_STREAM,
2151         .protocol       =       IPPROTO_TCP,
2152         .prot           =       &tcpv6_prot,
2153         .ops            =       &inet6_stream_ops,
2154         .capability     =       -1,
2155         .no_check       =       0,
2156         .flags          =       INET_PROTOSW_PERMANENT |
2157                                 INET_PROTOSW_ICSK,
2158 };
2159
2160 void __init tcpv6_init(void)
2161 {
2162         /* register inet6 protocol */
2163         if (inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP) < 0)
2164                 printk(KERN_ERR "tcpv6_init: Could not register protocol\n");
2165         inet6_register_protosw(&tcpv6_protosw);
2166
2167         if (inet_csk_ctl_sock_create(&tcp6_socket, PF_INET6, SOCK_RAW,
2168                                      IPPROTO_TCP) < 0)
2169                 panic("Failed to create the TCPv6 control socket.\n");
2170 }