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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/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/netdma.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, XFRM_LOOKUP_WAIT)) < 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 &tp->md5sig_info->keys6[i].base;
 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 tcp_md5sig_key *key;
 565         struct tcp_sock *tp = tcp_sk(sk);
 566         struct tcp6_md5sig_key *keys;
 567
 568         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                 if (tcp_alloc_md5sig_pool() == NULL) {
 585                         kfree(newkey);
 586                         return -ENOMEM;
 587                 }
 588                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 589                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 590                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 591
 592                         if (!keys) {
 593                                 tcp_free_md5sig_pool();
 594                                 kfree(newkey);
 595                                 return -ENOMEM;
 596                         }
 597
 598                         if (tp->md5sig_info->entries6)
 599                                 memmove(keys, tp->md5sig_info->keys6,
 600                                         (sizeof (tp->md5sig_info->keys6[0]) *
 601                                          tp->md5sig_info->entries6));
 602
 603                         kfree(tp->md5sig_info->keys6);
 604                         tp->md5sig_info->keys6 = keys;
 605                         tp->md5sig_info->alloced6++;
 606                 }
 607
 608                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 609                                peer);
 610                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
 611                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
 612
 613                 tp->md5sig_info->entries6++;
 614         }
 615         return 0;
 616 }
 617
 618 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 619                                u8 *newkey, __u8 newkeylen)
 620 {
 621         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 622                                  newkey, newkeylen);
 623 }
 624
 625 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 626 {
 627         struct tcp_sock *tp = tcp_sk(sk);
 628         int i;
 629
 630         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 631                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, peer) == 0) {
 632                         /* Free the key */
 633                         kfree(tp->md5sig_info->keys6[i].base.key);
 634                         tp->md5sig_info->entries6--;
 635
 636                         if (tp->md5sig_info->entries6 == 0) {
 637                                 kfree(tp->md5sig_info->keys6);
 638                                 tp->md5sig_info->keys6 = NULL;
 639                                 tp->md5sig_info->alloced6 = 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                         tcp_free_md5sig_pool();
 649                         return 0;
 650                 }
 651         }
 652         return -ENOENT;
 653 }
 654
 655 static void tcp_v6_clear_md5_list (struct sock *sk)
 656 {
 657         struct tcp_sock *tp = tcp_sk(sk);
 658         int i;
 659
 660         if (tp->md5sig_info->entries6) {
 661                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 662                         kfree(tp->md5sig_info->keys6[i].base.key);
 663                 tp->md5sig_info->entries6 = 0;
 664                 tcp_free_md5sig_pool();
 665         }
 666
 667         kfree(tp->md5sig_info->keys6);
 668         tp->md5sig_info->keys6 = NULL;
 669         tp->md5sig_info->alloced6 = 0;
 670
 671         if (tp->md5sig_info->entries4) {
 672                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 673                         kfree(tp->md5sig_info->keys4[i].base.key);
 674                 tp->md5sig_info->entries4 = 0;
 675                 tcp_free_md5sig_pool();
 676         }
 677
 678         kfree(tp->md5sig_info->keys4);
 679         tp->md5sig_info->keys4 = NULL;
 680         tp->md5sig_info->alloced4 = 0;
 681 }
 682
 683 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 684                                   int optlen)
 685 {
 686         struct tcp_md5sig cmd;
 687         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 688         u8 *newkey;
 689
 690         if (optlen < sizeof(cmd))
 691                 return -EINVAL;
 692
 693         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 694                 return -EFAULT;
 695
 696         if (sin6->sin6_family != AF_INET6)
 697                 return -EINVAL;
 698
 699         if (!cmd.tcpm_keylen) {
 700                 if (!tcp_sk(sk)->md5sig_info)
 701                         return -ENOENT;
 702                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 703                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 704                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 705         }
 706
 707         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 708                 return -EINVAL;
 709
 710         if (!tcp_sk(sk)->md5sig_info) {
 711                 struct tcp_sock *tp = tcp_sk(sk);
 712                 struct tcp_md5sig_info *p;
 713
 714                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 715                 if (!p)
 716                         return -ENOMEM;
 717
 718                 tp->md5sig_info = p;
 719                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 720         }
 721
 722         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 723         if (!newkey)
 724                 return -ENOMEM;
 725         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 726                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 727                                          newkey, cmd.tcpm_keylen);
 728         }
 729         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 730 }
 731
 732 static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 733                                    struct in6_addr *saddr,
 734                                    struct in6_addr *daddr,
 735                                    struct tcphdr *th, int protocol,
 736                                    int tcplen)
 737 {
 738         struct scatterlist sg[4];
 739         __u16 data_len;
 740         int block = 0;
 741         __sum16 cksum;
 742         struct tcp_md5sig_pool *hp;
 743         struct tcp6_pseudohdr *bp;
 744         struct hash_desc *desc;
 745         int err;
 746         unsigned int nbytes = 0;
 747
 748         hp = tcp_get_md5sig_pool();
 749         if (!hp) {
 750                 printk(KERN_WARNING "%s(): hash pool not found...\n", __FUNCTION__);
 751                 goto clear_hash_noput;
 752         }
 753         bp = &hp->md5_blk.ip6;
 754         desc = &hp->md5_desc;
 755
 756         /* 1. TCP pseudo-header (RFC2460) */
 757         ipv6_addr_copy(&bp->saddr, saddr);
 758         ipv6_addr_copy(&bp->daddr, daddr);
 759         bp->len = htonl(tcplen);
 760         bp->protocol = htonl(protocol);
 761
 762         sg_init_table(sg, 4);
 763
 764         sg_set_buf(&sg[block++], bp, sizeof(*bp));
 765         nbytes += sizeof(*bp);
 766
 767         /* 2. TCP header, excluding options */
 768         cksum = th->check;
 769         th->check = 0;
 770         sg_set_buf(&sg[block++], th, sizeof(*th));
 771         nbytes += sizeof(*th);
 772
 773         /* 3. TCP segment data (if any) */
 774         data_len = tcplen - (th->doff << 2);
 775         if (data_len > 0) {
 776                 u8 *data = (u8 *)th + (th->doff << 2);
 777                 sg_set_buf(&sg[block++], data, data_len);
 778                 nbytes += data_len;
 779         }
 780
 781         /* 4. shared key */
 782         sg_set_buf(&sg[block++], key->key, key->keylen);
 783         nbytes += key->keylen;
 784
 785         sg_mark_end(&sg[block - 1]);
 786
 787         /* Now store the hash into the packet */
 788         err = crypto_hash_init(desc);
 789         if (err) {
 790                 printk(KERN_WARNING "%s(): hash_init failed\n", __FUNCTION__);
 791                 goto clear_hash;
 792         }
 793         err = crypto_hash_update(desc, sg, nbytes);
 794         if (err) {
 795                 printk(KERN_WARNING "%s(): hash_update failed\n", __FUNCTION__);
 796                 goto clear_hash;
 797         }
 798         err = crypto_hash_final(desc, md5_hash);
 799         if (err) {
 800                 printk(KERN_WARNING "%s(): hash_final failed\n", __FUNCTION__);
 801                 goto clear_hash;
 802         }
 803
 804         /* Reset header, and free up the crypto */
 805         tcp_put_md5sig_pool();
 806         th->check = cksum;
 807 out:
 808         return 0;
 809 clear_hash:
 810         tcp_put_md5sig_pool();
 811 clear_hash_noput:
 812         memset(md5_hash, 0, 16);
 813         goto out;
 814 }
 815
 816 static int tcp_v6_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 817                                 struct sock *sk,
 818                                 struct dst_entry *dst,
 819                                 struct request_sock *req,
 820                                 struct tcphdr *th, int protocol,
 821                                 int tcplen)
 822 {
 823         struct in6_addr *saddr, *daddr;
 824
 825         if (sk) {
 826                 saddr = &inet6_sk(sk)->saddr;
 827                 daddr = &inet6_sk(sk)->daddr;
 828         } else {
 829                 saddr = &inet6_rsk(req)->loc_addr;
 830                 daddr = &inet6_rsk(req)->rmt_addr;
 831         }
 832         return tcp_v6_do_calc_md5_hash(md5_hash, key,
 833                                        saddr, daddr,
 834                                        th, protocol, tcplen);
 835 }
 836
 837 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 838 {
 839         __u8 *hash_location = NULL;
 840         struct tcp_md5sig_key *hash_expected;
 841         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 842         struct tcphdr *th = tcp_hdr(skb);
 843         int length = (th->doff << 2) - sizeof (*th);
 844         int genhash;
 845         u8 *ptr;
 846         u8 newhash[16];
 847
 848         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 849
 850         /* If the TCP option is too short, we can short cut */
 851         if (length < TCPOLEN_MD5SIG)
 852                 return hash_expected ? 1 : 0;
 853
 854         /* parse options */
 855         ptr = (u8*)(th + 1);
 856         while (length > 0) {
 857                 int opcode = *ptr++;
 858                 int opsize;
 859
 860                 switch(opcode) {
 861                 case TCPOPT_EOL:
 862                         goto done_opts;
 863                 case TCPOPT_NOP:
 864                         length--;
 865                         continue;
 866                 default:
 867                         opsize = *ptr++;
 868                         if (opsize < 2 || opsize > length)
 869                                 goto done_opts;
 870                         if (opcode == TCPOPT_MD5SIG) {
 871                                 hash_location = ptr;
 872                                 goto done_opts;
 873                         }
 874                 }
 875                 ptr += opsize - 2;
 876                 length -= opsize;
 877         }
 878
 879 done_opts:
 880         /* do we have a hash as expected? */
 881         if (!hash_expected) {
 882                 if (!hash_location)
 883                         return 0;
 884                 if (net_ratelimit()) {
 885                         printk(KERN_INFO "MD5 Hash NOT expected but found "
 886                                "(" NIP6_FMT ", %u)->"
 887                                "(" NIP6_FMT ", %u)\n",
 888                                NIP6(ip6h->saddr), ntohs(th->source),
 889                                NIP6(ip6h->daddr), ntohs(th->dest));
 890                 }
 891                 return 1;
 892         }
 893
 894         if (!hash_location) {
 895                 if (net_ratelimit()) {
 896                         printk(KERN_INFO "MD5 Hash expected but NOT found "
 897                                "(" NIP6_FMT ", %u)->"
 898                                "(" NIP6_FMT ", %u)\n",
 899                                NIP6(ip6h->saddr), ntohs(th->source),
 900                                NIP6(ip6h->daddr), ntohs(th->dest));
 901                 }
 902                 return 1;
 903         }
 904
 905         /* check the signature */
 906         genhash = tcp_v6_do_calc_md5_hash(newhash,
 907                                           hash_expected,
 908                                           &ip6h->saddr, &ip6h->daddr,
 909                                           th, sk->sk_protocol,
 910                                           skb->len);
 911         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 912                 if (net_ratelimit()) {
 913                         printk(KERN_INFO "MD5 Hash %s for "
 914                                "(" NIP6_FMT ", %u)->"
 915                                "(" NIP6_FMT ", %u)\n",
 916                                genhash ? "failed" : "mismatch",
 917                                NIP6(ip6h->saddr), ntohs(th->source),
 918                                NIP6(ip6h->daddr), ntohs(th->dest));
 919                 }
 920                 return 1;
 921         }
 922         return 0;
 923 }
 924 #endif
 925
 926 static struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 927         .family         =       AF_INET6,
 928         .obj_size       =       sizeof(struct tcp6_request_sock),
 929         .rtx_syn_ack    =       tcp_v6_send_synack,
 930         .send_ack       =       tcp_v6_reqsk_send_ack,
 931         .destructor     =       tcp_v6_reqsk_destructor,
 932         .send_reset     =       tcp_v6_send_reset
 933 };
 934
 935 #ifdef CONFIG_TCP_MD5SIG
 936 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 937         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 938 };
 939 #endif
 940
 941 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 942         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 943         .twsk_unique    = tcp_twsk_unique,
 944         .twsk_destructor= tcp_twsk_destructor,
 945 };
 946
 947 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 948 {
 949         struct ipv6_pinfo *np = inet6_sk(sk);
 950         struct tcphdr *th = tcp_hdr(skb);
 951
 952         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 953                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 954                 skb->csum_start = skb_transport_header(skb) - skb->head;
 955                 skb->csum_offset = offsetof(struct tcphdr, check);
 956         } else {
 957                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 958                                             csum_partial((char *)th, th->doff<<2,
 959                                                          skb->csum));
 960         }
 961 }
 962
 963 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 964 {
 965         struct ipv6hdr *ipv6h;
 966         struct tcphdr *th;
 967
 968         if (!pskb_may_pull(skb, sizeof(*th)))
 969                 return -EINVAL;
 970
 971         ipv6h = ipv6_hdr(skb);
 972         th = tcp_hdr(skb);
 973
 974         th->check = 0;
 975         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 976                                      IPPROTO_TCP, 0);
 977         skb->csum_start = skb_transport_header(skb) - skb->head;
 978         skb->csum_offset = offsetof(struct tcphdr, check);
 979         skb->ip_summed = CHECKSUM_PARTIAL;
 980         return 0;
 981 }
 982
 983 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 984 {
 985         struct tcphdr *th = tcp_hdr(skb), *t1;
 986         struct sk_buff *buff;
 987         struct flowi fl;
 988         int tot_len = sizeof(*th);
 989 #ifdef CONFIG_TCP_MD5SIG
 990         struct tcp_md5sig_key *key;
 991 #endif
 992
 993         if (th->rst)
 994                 return;
 995
 996         if (!ipv6_unicast_destination(skb))
 997                 return;
 998
 999 #ifdef CONFIG_TCP_MD5SIG
1000         if (sk)
1001                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1002         else
1003                 key = NULL;
1004
1005         if (key)
1006                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1007 #endif
1008
1009         /*
1010          * We need to grab some memory, and put together an RST,
1011          * and then put it into the queue to be sent.
1012          */
1013
1014         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1015                          GFP_ATOMIC);
1016         if (buff == NULL)
1017                 return;
1018
1019         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1020
1021         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1022
1023         /* Swap the send and the receive. */
1024         memset(t1, 0, sizeof(*t1));
1025         t1->dest = th->source;
1026         t1->source = th->dest;
1027         t1->doff = tot_len / 4;
1028         t1->rst = 1;
1029
1030         if(th->ack) {
1031                 t1->seq = th->ack_seq;
1032         } else {
1033                 t1->ack = 1;
1034                 t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
1035                                     + skb->len - (th->doff<<2));
1036         }
1037
1038 #ifdef CONFIG_TCP_MD5SIG
1039         if (key) {
1040                 __be32 *opt = (__be32*)(t1 + 1);
1041                 opt[0] = htonl((TCPOPT_NOP << 24) |
1042                                (TCPOPT_NOP << 16) |
1043                                (TCPOPT_MD5SIG << 8) |
1044                                TCPOLEN_MD5SIG);
1045                 tcp_v6_do_calc_md5_hash((__u8 *)&opt[1], key,
1046                                         &ipv6_hdr(skb)->daddr,
1047                                         &ipv6_hdr(skb)->saddr,
1048                                         t1, IPPROTO_TCP, tot_len);
1049         }
1050 #endif
1051
1052         buff->csum = csum_partial((char *)t1, sizeof(*t1), 0);
1053
1054         memset(&fl, 0, sizeof(fl));
1055         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1056         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1057
1058         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1059                                     sizeof(*t1), IPPROTO_TCP,
1060                                     buff->csum);
1061
1062         fl.proto = IPPROTO_TCP;
1063         fl.oif = inet6_iif(skb);
1064         fl.fl_ip_dport = t1->dest;
1065         fl.fl_ip_sport = t1->source;
1066         security_skb_classify_flow(skb, &fl);
1067
1068         /* sk = NULL, but it is safe for now. RST socket required. */
1069         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1070
1071                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1072                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1073                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1074                         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
1075                         return;
1076                 }
1077         }
1078
1079         kfree_skb(buff);
1080 }
1081
1082 static void tcp_v6_send_ack(struct tcp_timewait_sock *tw,
1083                             struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
1084 {
1085         struct tcphdr *th = tcp_hdr(skb), *t1;
1086         struct sk_buff *buff;
1087         struct flowi fl;
1088         int tot_len = sizeof(struct tcphdr);
1089         __be32 *topt;
1090 #ifdef CONFIG_TCP_MD5SIG
1091         struct tcp_md5sig_key *key;
1092         struct tcp_md5sig_key tw_key;
1093 #endif
1094
1095 #ifdef CONFIG_TCP_MD5SIG
1096         if (!tw && skb->sk) {
1097                 key = tcp_v6_md5_do_lookup(skb->sk, &ipv6_hdr(skb)->daddr);
1098         } else if (tw && tw->tw_md5_keylen) {
1099                 tw_key.key = tw->tw_md5_key;
1100                 tw_key.keylen = tw->tw_md5_keylen;
1101                 key = &tw_key;
1102         } else {
1103                 key = NULL;
1104         }
1105 #endif
1106
1107         if (ts)
1108                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1109 #ifdef CONFIG_TCP_MD5SIG
1110         if (key)
1111                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1112 #endif
1113
1114         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1115                          GFP_ATOMIC);
1116         if (buff == NULL)
1117                 return;
1118
1119         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1120
1121         t1 = (struct tcphdr *) skb_push(buff,tot_len);
1122
1123         /* Swap the send and the receive. */
1124         memset(t1, 0, sizeof(*t1));
1125         t1->dest = th->source;
1126         t1->source = th->dest;
1127         t1->doff = tot_len/4;
1128         t1->seq = htonl(seq);
1129         t1->ack_seq = htonl(ack);
1130         t1->ack = 1;
1131         t1->window = htons(win);
1132
1133         topt = (__be32 *)(t1 + 1);
1134
1135         if (ts) {
1136                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1137                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1138                 *topt++ = htonl(tcp_time_stamp);
1139                 *topt = htonl(ts);
1140         }
1141
1142 #ifdef CONFIG_TCP_MD5SIG
1143         if (key) {
1144                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1145                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1146                 tcp_v6_do_calc_md5_hash((__u8 *)topt, key,
1147                                         &ipv6_hdr(skb)->daddr,
1148                                         &ipv6_hdr(skb)->saddr,
1149                                         t1, IPPROTO_TCP, tot_len);
1150         }
1151 #endif
1152
1153         buff->csum = csum_partial((char *)t1, tot_len, 0);
1154
1155         memset(&fl, 0, sizeof(fl));
1156         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1157         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1158
1159         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1160                                     tot_len, IPPROTO_TCP,
1161                                     buff->csum);
1162
1163         fl.proto = IPPROTO_TCP;
1164         fl.oif = inet6_iif(skb);
1165         fl.fl_ip_dport = t1->dest;
1166         fl.fl_ip_sport = t1->source;
1167         security_skb_classify_flow(skb, &fl);
1168
1169         if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {
1170                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1171                         ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
1172                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1173                         return;
1174                 }
1175         }
1176
1177         kfree_skb(buff);
1178 }
1179
1180 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1181 {
1182         struct inet_timewait_sock *tw = inet_twsk(sk);
1183         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1184
1185         tcp_v6_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1186                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1187                         tcptw->tw_ts_recent);
1188
1189         inet_twsk_put(tw);
1190 }
1191
1192 static void tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
1193 {
1194         tcp_v6_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent);
1195 }
1196
1197
1198 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1199 {
1200         struct request_sock *req, **prev;
1201         const struct tcphdr *th = tcp_hdr(skb);
1202         struct sock *nsk;
1203
1204         /* Find possible connection requests. */
1205         req = inet6_csk_search_req(sk, &prev, th->source,
1206                                    &ipv6_hdr(skb)->saddr,
1207                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1208         if (req)
1209                 return tcp_check_req(sk, skb, req, prev);
1210
1211         nsk = __inet6_lookup_established(&tcp_hashinfo, &ipv6_hdr(skb)->saddr,
1212                                          th->source, &ipv6_hdr(skb)->daddr,
1213                                          ntohs(th->dest), inet6_iif(skb));
1214
1215         if (nsk) {
1216                 if (nsk->sk_state != TCP_TIME_WAIT) {
1217                         bh_lock_sock(nsk);
1218                         return nsk;
1219                 }
1220                 inet_twsk_put(inet_twsk(nsk));
1221                 return NULL;
1222         }
1223
1224 #if 0 /*def CONFIG_SYN_COOKIES*/
1225         if (!th->rst && !th->syn && th->ack)
1226                 sk = cookie_v6_check(sk, skb, &(IPCB(skb)->opt));
1227 #endif
1228         return sk;
1229 }
1230
1231 /* FIXME: this is substantially similar to the ipv4 code.
1232  * Can some kind of merge be done? -- erics
1233  */
1234 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1235 {
1236         struct inet6_request_sock *treq;
1237         struct ipv6_pinfo *np = inet6_sk(sk);
1238         struct tcp_options_received tmp_opt;
1239         struct tcp_sock *tp = tcp_sk(sk);
1240         struct request_sock *req = NULL;
1241         __u32 isn = TCP_SKB_CB(skb)->when;
1242
1243         if (skb->protocol == htons(ETH_P_IP))
1244                 return tcp_v4_conn_request(sk, skb);
1245
1246         if (!ipv6_unicast_destination(skb))
1247                 goto drop;
1248
1249         /*
1250          *      There are no SYN attacks on IPv6, yet...
1251          */
1252         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1253                 if (net_ratelimit())
1254                         printk(KERN_INFO "TCPv6: dropping request, synflood is possible\n");
1255                 goto drop;
1256         }
1257
1258         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1259                 goto drop;
1260
1261         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1262         if (req == NULL)
1263                 goto drop;
1264
1265 #ifdef CONFIG_TCP_MD5SIG
1266         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1267 #endif
1268
1269         tcp_clear_options(&tmp_opt);
1270         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1271         tmp_opt.user_mss = tp->rx_opt.user_mss;
1272
1273         tcp_parse_options(skb, &tmp_opt, 0);
1274
1275         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1276         tcp_openreq_init(req, &tmp_opt, skb);
1277
1278         treq = inet6_rsk(req);
1279         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1280         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1281         TCP_ECN_create_request(req, tcp_hdr(skb));
1282         treq->pktopts = NULL;
1283         if (ipv6_opt_accepted(sk, skb) ||
1284             np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1285             np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1286                 atomic_inc(&skb->users);
1287                 treq->pktopts = skb;
1288         }
1289         treq->iif = sk->sk_bound_dev_if;
1290
1291         /* So that link locals have meaning */
1292         if (!sk->sk_bound_dev_if &&
1293             ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1294                 treq->iif = inet6_iif(skb);
1295
1296         if (isn == 0)
1297                 isn = tcp_v6_init_sequence(skb);
1298
1299         tcp_rsk(req)->snt_isn = isn;
1300
1301         security_inet_conn_request(sk, skb, req);
1302
1303         if (tcp_v6_send_synack(sk, req, NULL))
1304                 goto drop;
1305
1306         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1307         return 0;
1308
1309 drop:
1310         if (req)
1311                 reqsk_free(req);
1312
1313         return 0; /* don't send reset */
1314 }
1315
1316 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1317                                           struct request_sock *req,
1318                                           struct dst_entry *dst)
1319 {
1320         struct inet6_request_sock *treq = inet6_rsk(req);
1321         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1322         struct tcp6_sock *newtcp6sk;
1323         struct inet_sock *newinet;
1324         struct tcp_sock *newtp;
1325         struct sock *newsk;
1326         struct ipv6_txoptions *opt;
1327 #ifdef CONFIG_TCP_MD5SIG
1328         struct tcp_md5sig_key *key;
1329 #endif
1330
1331         if (skb->protocol == htons(ETH_P_IP)) {
1332                 /*
1333                  *      v6 mapped
1334                  */
1335
1336                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1337
1338                 if (newsk == NULL)
1339                         return NULL;
1340
1341                 newtcp6sk = (struct tcp6_sock *)newsk;
1342                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1343
1344                 newinet = inet_sk(newsk);
1345                 newnp = inet6_sk(newsk);
1346                 newtp = tcp_sk(newsk);
1347
1348                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1349
1350                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1351                               newinet->daddr);
1352
1353                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1354                               newinet->saddr);
1355
1356                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1357
1358                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1359                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1360 #ifdef CONFIG_TCP_MD5SIG
1361                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1362 #endif
1363
1364                 newnp->pktoptions  = NULL;
1365                 newnp->opt         = NULL;
1366                 newnp->mcast_oif   = inet6_iif(skb);
1367                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1368
1369                 /*
1370                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1371                  * here, tcp_create_openreq_child now does this for us, see the comment in
1372                  * that function for the gory details. -acme
1373                  */
1374
1375                 /* It is tricky place. Until this moment IPv4 tcp
1376                    worked with IPv6 icsk.icsk_af_ops.
1377                    Sync it now.
1378                  */
1379                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1380
1381                 return newsk;
1382         }
1383
1384         opt = np->opt;
1385
1386         if (sk_acceptq_is_full(sk))
1387                 goto out_overflow;
1388
1389         if (dst == NULL) {
1390                 struct in6_addr *final_p = NULL, final;
1391                 struct flowi fl;
1392
1393                 memset(&fl, 0, sizeof(fl));
1394                 fl.proto = IPPROTO_TCP;
1395                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1396                 if (opt && opt->srcrt) {
1397                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1398                         ipv6_addr_copy(&final, &fl.fl6_dst);
1399                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1400                         final_p = &final;
1401                 }
1402                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1403                 fl.oif = sk->sk_bound_dev_if;
1404                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1405                 fl.fl_ip_sport = inet_sk(sk)->sport;
1406                 security_req_classify_flow(req, &fl);
1407
1408                 if (ip6_dst_lookup(sk, &dst, &fl))
1409                         goto out;
1410
1411                 if (final_p)
1412                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1413
1414                 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
1415                         goto out;
1416         }
1417
1418         newsk = tcp_create_openreq_child(sk, req, skb);
1419         if (newsk == NULL)
1420                 goto out;
1421
1422         /*
1423          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1424          * count here, tcp_create_openreq_child now does this for us, see the
1425          * comment in that function for the gory details. -acme
1426          */
1427
1428         newsk->sk_gso_type = SKB_GSO_TCPV6;
1429         __ip6_dst_store(newsk, dst, NULL, NULL);
1430
1431         newtcp6sk = (struct tcp6_sock *)newsk;
1432         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1433
1434         newtp = tcp_sk(newsk);
1435         newinet = inet_sk(newsk);
1436         newnp = inet6_sk(newsk);
1437
1438         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1439
1440         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1441         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1442         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1443         newsk->sk_bound_dev_if = treq->iif;
1444
1445         /* Now IPv6 options...
1446
1447            First: no IPv4 options.
1448          */
1449         newinet->opt = NULL;
1450         newnp->ipv6_fl_list = NULL;
1451
1452         /* Clone RX bits */
1453         newnp->rxopt.all = np->rxopt.all;
1454
1455         /* Clone pktoptions received with SYN */
1456         newnp->pktoptions = NULL;
1457         if (treq->pktopts != NULL) {
1458                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1459                 kfree_skb(treq->pktopts);
1460                 treq->pktopts = NULL;
1461                 if (newnp->pktoptions)
1462                         skb_set_owner_r(newnp->pktoptions, newsk);
1463         }
1464         newnp->opt        = NULL;
1465         newnp->mcast_oif  = inet6_iif(skb);
1466         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1467
1468         /* Clone native IPv6 options from listening socket (if any)
1469
1470            Yes, keeping reference count would be much more clever,
1471            but we make one more one thing there: reattach optmem
1472            to newsk.
1473          */
1474         if (opt) {
1475                 newnp->opt = ipv6_dup_options(newsk, opt);
1476                 if (opt != np->opt)
1477                         sock_kfree_s(sk, opt, opt->tot_len);
1478         }
1479
1480         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1481         if (newnp->opt)
1482                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1483                                                      newnp->opt->opt_flen);
1484
1485         tcp_mtup_init(newsk);
1486         tcp_sync_mss(newsk, dst_mtu(dst));
1487         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1488         tcp_initialize_rcv_mss(newsk);
1489
1490         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1491
1492 #ifdef CONFIG_TCP_MD5SIG
1493         /* Copy over the MD5 key from the original socket */
1494         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1495                 /* We're using one, so create a matching key
1496                  * on the newsk structure. If we fail to get
1497                  * memory, then we end up not copying the key
1498                  * across. Shucks.
1499                  */
1500                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1501                 if (newkey != NULL)
1502                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1503                                           newkey, key->keylen);
1504         }
1505 #endif
1506
1507         __inet6_hash(&tcp_hashinfo, newsk);
1508         inet_inherit_port(&tcp_hashinfo, sk, newsk);
1509
1510         return newsk;
1511
1512 out_overflow:
1513         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
1514 out:
1515         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
1516         if (opt && opt != np->opt)
1517                 sock_kfree_s(sk, opt, opt->tot_len);
1518         dst_release(dst);
1519         return NULL;
1520 }
1521
1522 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1523 {
1524         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1525                 if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1526                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1527                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1528                         return 0;
1529                 }
1530         }
1531
1532         skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1533                                               &ipv6_hdr(skb)->saddr,
1534                                               &ipv6_hdr(skb)->daddr, 0));
1535
1536         if (skb->len <= 76) {
1537                 return __skb_checksum_complete(skb);
1538         }
1539         return 0;
1540 }
1541
1542 /* The socket must have it's spinlock held when we get
1543  * here.
1544  *
1545  * We have a potential double-lock case here, so even when
1546  * doing backlog processing we use the BH locking scheme.
1547  * This is because we cannot sleep with the original spinlock
1548  * held.
1549  */
1550 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1551 {
1552         struct ipv6_pinfo *np = inet6_sk(sk);
1553         struct tcp_sock *tp;
1554         struct sk_buff *opt_skb = NULL;
1555
1556         /* Imagine: socket is IPv6. IPv4 packet arrives,
1557            goes to IPv4 receive handler and backlogged.
1558            From backlog it always goes here. Kerboom...
1559            Fortunately, tcp_rcv_established and rcv_established
1560            handle them correctly, but it is not case with
1561            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1562          */
1563
1564         if (skb->protocol == htons(ETH_P_IP))
1565                 return tcp_v4_do_rcv(sk, skb);
1566
1567 #ifdef CONFIG_TCP_MD5SIG
1568         if (tcp_v6_inbound_md5_hash (sk, skb))
1569                 goto discard;
1570 #endif
1571
1572         if (sk_filter(sk, skb))
1573                 goto discard;
1574
1575         /*
1576          *      socket locking is here for SMP purposes as backlog rcv
1577          *      is currently called with bh processing disabled.
1578          */
1579
1580         /* Do Stevens' IPV6_PKTOPTIONS.
1581
1582            Yes, guys, it is the only place in our code, where we
1583            may make it not affecting IPv4.
1584            The rest of code is protocol independent,
1585            and I do not like idea to uglify IPv4.
1586
1587            Actually, all the idea behind IPV6_PKTOPTIONS
1588            looks not very well thought. For now we latch
1589            options, received in the last packet, enqueued
1590            by tcp. Feel free to propose better solution.
1591                                                --ANK (980728)
1592          */
1593         if (np->rxopt.all)
1594                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1595
1596         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1597                 TCP_CHECK_TIMER(sk);
1598                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1599                         goto reset;
1600                 TCP_CHECK_TIMER(sk);
1601                 if (opt_skb)
1602                         goto ipv6_pktoptions;
1603                 return 0;
1604         }
1605
1606         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1607                 goto csum_err;
1608
1609         if (sk->sk_state == TCP_LISTEN) {
1610                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1611                 if (!nsk)
1612                         goto discard;
1613
1614                 /*
1615                  * Queue it on the new socket if the new socket is active,
1616                  * otherwise we just shortcircuit this and continue with
1617                  * the new socket..
1618                  */
1619                 if(nsk != sk) {
1620                         if (tcp_child_process(sk, nsk, skb))
1621                                 goto reset;
1622                         if (opt_skb)
1623                                 __kfree_skb(opt_skb);
1624                         return 0;
1625                 }
1626         }
1627
1628         TCP_CHECK_TIMER(sk);
1629         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1630                 goto reset;
1631         TCP_CHECK_TIMER(sk);
1632         if (opt_skb)
1633                 goto ipv6_pktoptions;
1634         return 0;
1635
1636 reset:
1637         tcp_v6_send_reset(sk, skb);
1638 discard:
1639         if (opt_skb)
1640                 __kfree_skb(opt_skb);
1641         kfree_skb(skb);
1642         return 0;
1643 csum_err:
1644         TCP_INC_STATS_BH(TCP_MIB_INERRS);
1645         goto discard;
1646
1647
1648 ipv6_pktoptions:
1649         /* Do you ask, what is it?
1650
1651            1. skb was enqueued by tcp.
1652            2. skb is added to tail of read queue, rather than out of order.
1653            3. socket is not in passive state.
1654            4. Finally, it really contains options, which user wants to receive.
1655          */
1656         tp = tcp_sk(sk);
1657         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1658             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1659                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1660                         np->mcast_oif = inet6_iif(opt_skb);
1661                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1662                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1663                 if (ipv6_opt_accepted(sk, opt_skb)) {
1664                         skb_set_owner_r(opt_skb, sk);
1665                         opt_skb = xchg(&np->pktoptions, opt_skb);
1666                 } else {
1667                         __kfree_skb(opt_skb);
1668                         opt_skb = xchg(&np->pktoptions, NULL);
1669                 }
1670         }
1671
1672         if (opt_skb)
1673                 kfree_skb(opt_skb);
1674         return 0;
1675 }
1676
1677 static int tcp_v6_rcv(struct sk_buff *skb)
1678 {
1679         struct tcphdr *th;
1680         struct sock *sk;
1681         int ret;
1682
1683         if (skb->pkt_type != PACKET_HOST)
1684                 goto discard_it;
1685
1686         /*
1687          *      Count it even if it's bad.
1688          */
1689         TCP_INC_STATS_BH(TCP_MIB_INSEGS);
1690
1691         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1692                 goto discard_it;
1693
1694         th = tcp_hdr(skb);
1695
1696         if (th->doff < sizeof(struct tcphdr)/4)
1697                 goto bad_packet;
1698         if (!pskb_may_pull(skb, th->doff*4))
1699                 goto discard_it;
1700
1701         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1702                 goto bad_packet;
1703
1704         th = tcp_hdr(skb);
1705         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1706         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1707                                     skb->len - th->doff*4);
1708         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1709         TCP_SKB_CB(skb)->when = 0;
1710         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1711         TCP_SKB_CB(skb)->sacked = 0;
1712
1713         sk = __inet6_lookup(&tcp_hashinfo, &ipv6_hdr(skb)->saddr, th->source,
1714                             &ipv6_hdr(skb)->daddr, ntohs(th->dest),
1715                             inet6_iif(skb));
1716
1717         if (!sk)
1718                 goto no_tcp_socket;
1719
1720 process:
1721         if (sk->sk_state == TCP_TIME_WAIT)
1722                 goto do_time_wait;
1723
1724         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1725                 goto discard_and_relse;
1726
1727         if (sk_filter(sk, skb))
1728                 goto discard_and_relse;
1729
1730         skb->dev = NULL;
1731
1732         bh_lock_sock_nested(sk);
1733         ret = 0;
1734         if (!sock_owned_by_user(sk)) {
1735 #ifdef CONFIG_NET_DMA
1736                 struct tcp_sock *tp = tcp_sk(sk);
1737                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1738                         tp->ucopy.dma_chan = get_softnet_dma();
1739                 if (tp->ucopy.dma_chan)
1740                         ret = tcp_v6_do_rcv(sk, skb);
1741                 else
1742 #endif
1743                 {
1744                         if (!tcp_prequeue(sk, skb))
1745                                 ret = tcp_v6_do_rcv(sk, skb);
1746                 }
1747         } else
1748                 sk_add_backlog(sk, skb);
1749         bh_unlock_sock(sk);
1750
1751         sock_put(sk);
1752         return ret ? -1 : 0;
1753
1754 no_tcp_socket:
1755         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1756                 goto discard_it;
1757
1758         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1759 bad_packet:
1760                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1761         } else {
1762                 tcp_v6_send_reset(NULL, skb);
1763         }
1764
1765 discard_it:
1766
1767         /*
1768          *      Discard frame
1769          */
1770
1771         kfree_skb(skb);
1772         return 0;
1773
1774 discard_and_relse:
1775         sock_put(sk);
1776         goto discard_it;
1777
1778 do_time_wait:
1779         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1780                 inet_twsk_put(inet_twsk(sk));
1781                 goto discard_it;
1782         }
1783
1784         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1785                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1786                 inet_twsk_put(inet_twsk(sk));
1787                 goto discard_it;
1788         }
1789
1790         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1791         case TCP_TW_SYN:
1792         {
1793                 struct sock *sk2;
1794
1795                 sk2 = inet6_lookup_listener(&tcp_hashinfo,
1796                                             &ipv6_hdr(skb)->daddr,
1797                                             ntohs(th->dest), inet6_iif(skb));
1798                 if (sk2 != NULL) {
1799                         struct inet_timewait_sock *tw = inet_twsk(sk);
1800                         inet_twsk_deschedule(tw, &tcp_death_row);
1801                         inet_twsk_put(tw);
1802                         sk = sk2;
1803                         goto process;
1804                 }
1805                 /* Fall through to ACK */
1806         }
1807         case TCP_TW_ACK:
1808                 tcp_v6_timewait_ack(sk, skb);
1809                 break;
1810         case TCP_TW_RST:
1811                 goto no_tcp_socket;
1812         case TCP_TW_SUCCESS:;
1813         }
1814         goto discard_it;
1815 }
1816
1817 static int tcp_v6_remember_stamp(struct sock *sk)
1818 {
1819         /* Alas, not yet... */
1820         return 0;
1821 }
1822
1823 static struct inet_connection_sock_af_ops ipv6_specific = {
1824         .queue_xmit        = inet6_csk_xmit,
1825         .send_check        = tcp_v6_send_check,
1826         .rebuild_header    = inet6_sk_rebuild_header,
1827         .conn_request      = tcp_v6_conn_request,
1828         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1829         .remember_stamp    = tcp_v6_remember_stamp,
1830         .net_header_len    = sizeof(struct ipv6hdr),
1831         .setsockopt        = ipv6_setsockopt,
1832         .getsockopt        = ipv6_getsockopt,
1833         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1834         .sockaddr_len      = sizeof(struct sockaddr_in6),
1835 #ifdef CONFIG_COMPAT
1836         .compat_setsockopt = compat_ipv6_setsockopt,
1837         .compat_getsockopt = compat_ipv6_getsockopt,
1838 #endif
1839 };
1840
1841 #ifdef CONFIG_TCP_MD5SIG
1842 static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1843         .md5_lookup     =       tcp_v6_md5_lookup,
1844         .calc_md5_hash  =       tcp_v6_calc_md5_hash,
1845         .md5_add        =       tcp_v6_md5_add_func,
1846         .md5_parse      =       tcp_v6_parse_md5_keys,
1847 };
1848 #endif
1849
1850 /*
1851  *      TCP over IPv4 via INET6 API
1852  */
1853
1854 static struct inet_connection_sock_af_ops ipv6_mapped = {
1855         .queue_xmit        = ip_queue_xmit,
1856         .send_check        = tcp_v4_send_check,
1857         .rebuild_header    = inet_sk_rebuild_header,
1858         .conn_request      = tcp_v6_conn_request,
1859         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1860         .remember_stamp    = tcp_v4_remember_stamp,
1861         .net_header_len    = sizeof(struct iphdr),
1862         .setsockopt        = ipv6_setsockopt,
1863         .getsockopt        = ipv6_getsockopt,
1864         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1865         .sockaddr_len      = sizeof(struct sockaddr_in6),
1866 #ifdef CONFIG_COMPAT
1867         .compat_setsockopt = compat_ipv6_setsockopt,
1868         .compat_getsockopt = compat_ipv6_getsockopt,
1869 #endif
1870 };
1871
1872 #ifdef CONFIG_TCP_MD5SIG
1873 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1874         .md5_lookup     =       tcp_v4_md5_lookup,
1875         .calc_md5_hash  =       tcp_v4_calc_md5_hash,
1876         .md5_add        =       tcp_v6_md5_add_func,
1877         .md5_parse      =       tcp_v6_parse_md5_keys,
1878 };
1879 #endif
1880
1881 /* NOTE: A lot of things set to zero explicitly by call to
1882  *       sk_alloc() so need not be done here.
1883  */
1884 static int tcp_v6_init_sock(struct sock *sk)
1885 {
1886         struct inet_connection_sock *icsk = inet_csk(sk);
1887         struct tcp_sock *tp = tcp_sk(sk);
1888
1889         skb_queue_head_init(&tp->out_of_order_queue);
1890         tcp_init_xmit_timers(sk);
1891         tcp_prequeue_init(tp);
1892
1893         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1894         tp->mdev = TCP_TIMEOUT_INIT;
1895
1896         /* So many TCP implementations out there (incorrectly) count the
1897          * initial SYN frame in their delayed-ACK and congestion control
1898          * algorithms that we must have the following bandaid to talk
1899          * efficiently to them.  -DaveM
1900          */
1901         tp->snd_cwnd = 2;
1902
1903         /* See draft-stevens-tcpca-spec-01 for discussion of the
1904          * initialization of these values.
1905          */
1906         tp->snd_ssthresh = 0x7fffffff;
1907         tp->snd_cwnd_clamp = ~0;
1908         tp->mss_cache = 536;
1909
1910         tp->reordering = sysctl_tcp_reordering;
1911
1912         sk->sk_state = TCP_CLOSE;
1913
1914         icsk->icsk_af_ops = &ipv6_specific;
1915         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1916         icsk->icsk_sync_mss = tcp_sync_mss;
1917         sk->sk_write_space = sk_stream_write_space;
1918         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1919
1920 #ifdef CONFIG_TCP_MD5SIG
1921         tp->af_specific = &tcp_sock_ipv6_specific;
1922 #endif
1923
1924         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1925         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1926
1927         atomic_inc(&tcp_sockets_allocated);
1928
1929         return 0;
1930 }
1931
1932 static int tcp_v6_destroy_sock(struct sock *sk)
1933 {
1934 #ifdef CONFIG_TCP_MD5SIG
1935         /* Clean up the MD5 key list */
1936         if (tcp_sk(sk)->md5sig_info)
1937                 tcp_v6_clear_md5_list(sk);
1938 #endif
1939         tcp_v4_destroy_sock(sk);
1940         return inet6_destroy_sock(sk);
1941 }
1942
1943 #ifdef CONFIG_PROC_FS
1944 /* Proc filesystem TCPv6 sock list dumping. */
1945 static void get_openreq6(struct seq_file *seq,
1946                          struct sock *sk, struct request_sock *req, int i, int uid)
1947 {
1948         int ttd = req->expires - jiffies;
1949         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1950         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1951
1952         if (ttd < 0)
1953                 ttd = 0;
1954
1955         seq_printf(seq,
1956                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1957                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1958                    i,
1959                    src->s6_addr32[0], src->s6_addr32[1],
1960                    src->s6_addr32[2], src->s6_addr32[3],
1961                    ntohs(inet_sk(sk)->sport),
1962                    dest->s6_addr32[0], dest->s6_addr32[1],
1963                    dest->s6_addr32[2], dest->s6_addr32[3],
1964                    ntohs(inet_rsk(req)->rmt_port),
1965                    TCP_SYN_RECV,
1966                    0,0, /* could print option size, but that is af dependent. */
1967                    1,   /* timers active (only the expire timer) */
1968                    jiffies_to_clock_t(ttd),
1969                    req->retrans,
1970                    uid,
1971                    0,  /* non standard timer */
1972                    0, /* open_requests have no inode */
1973                    0, req);
1974 }
1975
1976 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1977 {
1978         struct in6_addr *dest, *src;
1979         __u16 destp, srcp;
1980         int timer_active;
1981         unsigned long timer_expires;
1982         struct inet_sock *inet = inet_sk(sp);
1983         struct tcp_sock *tp = tcp_sk(sp);
1984         const struct inet_connection_sock *icsk = inet_csk(sp);
1985         struct ipv6_pinfo *np = inet6_sk(sp);
1986
1987         dest  = &np->daddr;
1988         src   = &np->rcv_saddr;
1989         destp = ntohs(inet->dport);
1990         srcp  = ntohs(inet->sport);
1991
1992         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1993                 timer_active    = 1;
1994                 timer_expires   = icsk->icsk_timeout;
1995         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1996                 timer_active    = 4;
1997                 timer_expires   = icsk->icsk_timeout;
1998         } else if (timer_pending(&sp->sk_timer)) {
1999                 timer_active    = 2;
2000                 timer_expires   = sp->sk_timer.expires;
2001         } else {
2002                 timer_active    = 0;
2003                 timer_expires = jiffies;
2004         }
2005
2006         seq_printf(seq,
2007                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2008                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d\n",
2009                    i,
2010                    src->s6_addr32[0], src->s6_addr32[1],
2011                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2012                    dest->s6_addr32[0], dest->s6_addr32[1],
2013                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2014                    sp->sk_state,
2015                    tp->write_seq-tp->snd_una,
2016                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2017                    timer_active,
2018                    jiffies_to_clock_t(timer_expires - jiffies),
2019                    icsk->icsk_retransmits,
2020                    sock_i_uid(sp),
2021                    icsk->icsk_probes_out,
2022                    sock_i_ino(sp),
2023                    atomic_read(&sp->sk_refcnt), sp,
2024                    icsk->icsk_rto,
2025                    icsk->icsk_ack.ato,
2026                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2027                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
2028                    );
2029 }
2030
2031 static void get_timewait6_sock(struct seq_file *seq,
2032                                struct inet_timewait_sock *tw, int i)
2033 {
2034         struct in6_addr *dest, *src;
2035         __u16 destp, srcp;
2036         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2037         int ttd = tw->tw_ttd - jiffies;
2038
2039         if (ttd < 0)
2040                 ttd = 0;
2041
2042         dest = &tw6->tw_v6_daddr;
2043         src  = &tw6->tw_v6_rcv_saddr;
2044         destp = ntohs(tw->tw_dport);
2045         srcp  = ntohs(tw->tw_sport);
2046
2047         seq_printf(seq,
2048                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2049                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2050                    i,
2051                    src->s6_addr32[0], src->s6_addr32[1],
2052                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2053                    dest->s6_addr32[0], dest->s6_addr32[1],
2054                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2055                    tw->tw_substate, 0, 0,
2056                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2057                    atomic_read(&tw->tw_refcnt), tw);
2058 }
2059
2060 static int tcp6_seq_show(struct seq_file *seq, void *v)
2061 {
2062         struct tcp_iter_state *st;
2063
2064         if (v == SEQ_START_TOKEN) {
2065                 seq_puts(seq,
2066                          "  sl  "
2067                          "local_address                         "
2068                          "remote_address                        "
2069                          "st tx_queue rx_queue tr tm->when retrnsmt"
2070                          "   uid  timeout inode\n");
2071                 goto out;
2072         }
2073         st = seq->private;
2074
2075         switch (st->state) {
2076         case TCP_SEQ_STATE_LISTENING:
2077         case TCP_SEQ_STATE_ESTABLISHED:
2078                 get_tcp6_sock(seq, v, st->num);
2079                 break;
2080         case TCP_SEQ_STATE_OPENREQ:
2081                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2082                 break;
2083         case TCP_SEQ_STATE_TIME_WAIT:
2084                 get_timewait6_sock(seq, v, st->num);
2085                 break;
2086         }
2087 out:
2088         return 0;
2089 }
2090
2091 static struct file_operations tcp6_seq_fops;
2092 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2093         .owner          = THIS_MODULE,
2094         .name           = "tcp6",
2095         .family         = AF_INET6,
2096         .seq_show       = tcp6_seq_show,
2097         .seq_fops       = &tcp6_seq_fops,
2098 };
2099
2100 int __init tcp6_proc_init(void)
2101 {
2102         return tcp_proc_register(&tcp6_seq_afinfo);
2103 }
2104
2105 void tcp6_proc_exit(void)
2106 {
2107         tcp_proc_unregister(&tcp6_seq_afinfo);
2108 }
2109 #endif
2110
2111 DEFINE_PROTO_INUSE(tcpv6)
2112
2113 struct proto tcpv6_prot = {
2114         .name                   = "TCPv6",
2115         .owner                  = THIS_MODULE,
2116         .close                  = tcp_close,
2117         .connect                = tcp_v6_connect,
2118         .disconnect             = tcp_disconnect,
2119         .accept                 = inet_csk_accept,
2120         .ioctl                  = tcp_ioctl,
2121         .init                   = tcp_v6_init_sock,
2122         .destroy                = tcp_v6_destroy_sock,
2123         .shutdown               = tcp_shutdown,
2124         .setsockopt             = tcp_setsockopt,
2125         .getsockopt             = tcp_getsockopt,
2126         .recvmsg                = tcp_recvmsg,
2127         .backlog_rcv            = tcp_v6_do_rcv,
2128         .hash                   = tcp_v6_hash,
2129         .unhash                 = tcp_unhash,
2130         .get_port               = tcp_v6_get_port,
2131         .enter_memory_pressure  = tcp_enter_memory_pressure,
2132         .sockets_allocated      = &tcp_sockets_allocated,
2133         .memory_allocated       = &tcp_memory_allocated,
2134         .memory_pressure        = &tcp_memory_pressure,
2135         .orphan_count           = &tcp_orphan_count,
2136         .sysctl_mem             = sysctl_tcp_mem,
2137         .sysctl_wmem            = sysctl_tcp_wmem,
2138         .sysctl_rmem            = sysctl_tcp_rmem,
2139         .max_header             = MAX_TCP_HEADER,
2140         .obj_size               = sizeof(struct tcp6_sock),
2141         .twsk_prot              = &tcp6_timewait_sock_ops,
2142         .rsk_prot               = &tcp6_request_sock_ops,
2143 #ifdef CONFIG_COMPAT
2144         .compat_setsockopt      = compat_tcp_setsockopt,
2145         .compat_getsockopt      = compat_tcp_getsockopt,
2146 #endif
2147         REF_PROTO_INUSE(tcpv6)
2148 };
2149
2150 static struct inet6_protocol tcpv6_protocol = {
2151         .handler        =       tcp_v6_rcv,
2152         .err_handler    =       tcp_v6_err,
2153         .gso_send_check =       tcp_v6_gso_send_check,
2154         .gso_segment    =       tcp_tso_segment,
2155         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2156 };
2157
2158 static struct inet_protosw tcpv6_protosw = {
2159         .type           =       SOCK_STREAM,
2160         .protocol       =       IPPROTO_TCP,
2161         .prot           =       &tcpv6_prot,
2162         .ops            =       &inet6_stream_ops,
2163         .capability     =       -1,
2164         .no_check       =       0,
2165         .flags          =       INET_PROTOSW_PERMANENT |
2166                                 INET_PROTOSW_ICSK,
2167 };
2168
2169 int __init tcpv6_init(void)
2170 {
2171         int ret;
2172
2173         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2174         if (ret)
2175                 goto out;
2176
2177         /* register inet6 protocol */
2178         ret = inet6_register_protosw(&tcpv6_protosw);
2179         if (ret)
2180                 goto out_tcpv6_protocol;
2181
2182         ret = inet_csk_ctl_sock_create(&tcp6_socket, PF_INET6,
2183                                        SOCK_RAW, IPPROTO_TCP);
2184         if (ret)
2185                 goto out_tcpv6_protosw;
2186 out:
2187         return ret;
2188
2189 out_tcpv6_protocol:
2190         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2191 out_tcpv6_protosw:
2192         inet6_unregister_protosw(&tcpv6_protosw);
2193         goto out;
2194 }
2195
2196 void __exit tcpv6_exit(void)
2197 {
2198         sock_release(tcp6_socket);
2199         inet6_unregister_protosw(&tcpv6_protosw);
2200         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2201 }