SAFE public projects git trees. - safe/jmp/linux-2.6/blob - net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41
  42 #include <linux/ipv6.h>
  43 #include <linux/icmpv6.h>
  44 #include <linux/random.h>
  45
  46 #include <net/tcp.h>
  47 #include <net/ndisc.h>
  48 #include <net/inet6_hashtables.h>
  49 #include <net/inet6_connection_sock.h>
  50 #include <net/ipv6.h>
  51 #include <net/transp_v6.h>
  52 #include <net/addrconf.h>
  53 #include <net/ip6_route.h>
  54 #include <net/ip6_checksum.h>
  55 #include <net/inet_ecn.h>
  56 #include <net/protocol.h>
  57 #include <net/xfrm.h>
  58 #include <net/snmp.h>
  59 #include <net/dsfield.h>
  60 #include <net/timewait_sock.h>
  61 #include <net/netdma.h>
  62 #include <net/inet_common.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 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  73 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  74                                       struct request_sock *req);
  75
  76 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  77
  78 static struct inet_connection_sock_af_ops ipv6_mapped;
  79 static struct inet_connection_sock_af_ops ipv6_specific;
  80 #ifdef CONFIG_TCP_MD5SIG
  81 static struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  82 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  83 #else
  84 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  85                                                    struct in6_addr *addr)
  86 {
  87         return NULL;
  88 }
  89 #endif
  90
  91 static void tcp_v6_hash(struct sock *sk)
  92 {
  93         if (sk->sk_state != TCP_CLOSE) {
  94                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
  95                         tcp_prot.hash(sk);
  96                         return;
  97                 }
  98                 local_bh_disable();
  99                 __inet6_hash(sk);
 100                 local_bh_enable();
 101         }
 102 }
 103
 104 static __inline__ __sum16 tcp_v6_check(int len,
 105                                    struct in6_addr *saddr,
 106                                    struct in6_addr *daddr,
 107                                    __wsum base)
 108 {
 109         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
 110 }
 111
 112 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
 113 {
 114         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 115                                             ipv6_hdr(skb)->saddr.s6_addr32,
 116                                             tcp_hdr(skb)->dest,
 117                                             tcp_hdr(skb)->source);
 118 }
 119
 120 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 121                           int addr_len)
 122 {
 123         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 124         struct inet_sock *inet = inet_sk(sk);
 125         struct inet_connection_sock *icsk = inet_csk(sk);
 126         struct ipv6_pinfo *np = inet6_sk(sk);
 127         struct tcp_sock *tp = tcp_sk(sk);
 128         struct in6_addr *saddr = NULL, *final_p = NULL, final;
 129         struct flowi fl;
 130         struct dst_entry *dst;
 131         int addr_type;
 132         int err;
 133
 134         if (addr_len < SIN6_LEN_RFC2133)
 135                 return -EINVAL;
 136
 137         if (usin->sin6_family != AF_INET6)
 138                 return(-EAFNOSUPPORT);
 139
 140         memset(&fl, 0, sizeof(fl));
 141
 142         if (np->sndflow) {
 143                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 144                 IP6_ECN_flow_init(fl.fl6_flowlabel);
 145                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
 146                         struct ip6_flowlabel *flowlabel;
 147                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
 148                         if (flowlabel == NULL)
 149                                 return -EINVAL;
 150                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
 151                         fl6_sock_release(flowlabel);
 152                 }
 153         }
 154
 155         /*
 156          *      connect() to INADDR_ANY means loopback (BSD'ism).
 157          */
 158
 159         if(ipv6_addr_any(&usin->sin6_addr))
 160                 usin->sin6_addr.s6_addr[15] = 0x1;
 161
 162         addr_type = ipv6_addr_type(&usin->sin6_addr);
 163
 164         if(addr_type & IPV6_ADDR_MULTICAST)
 165                 return -ENETUNREACH;
 166
 167         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 168                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 169                     usin->sin6_scope_id) {
 170                         /* If interface is set while binding, indices
 171                          * must coincide.
 172                          */
 173                         if (sk->sk_bound_dev_if &&
 174                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 175                                 return -EINVAL;
 176
 177                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 178                 }
 179
 180                 /* Connect to link-local address requires an interface */
 181                 if (!sk->sk_bound_dev_if)
 182                         return -EINVAL;
 183         }
 184
 185         if (tp->rx_opt.ts_recent_stamp &&
 186             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 187                 tp->rx_opt.ts_recent = 0;
 188                 tp->rx_opt.ts_recent_stamp = 0;
 189                 tp->write_seq = 0;
 190         }
 191
 192         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
 193         np->flow_label = fl.fl6_flowlabel;
 194
 195         /*
 196          *      TCP over IPv4
 197          */
 198
 199         if (addr_type == IPV6_ADDR_MAPPED) {
 200                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 201                 struct sockaddr_in sin;
 202
 203                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 204
 205                 if (__ipv6_only_sock(sk))
 206                         return -ENETUNREACH;
 207
 208                 sin.sin_family = AF_INET;
 209                 sin.sin_port = usin->sin6_port;
 210                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 211
 212                 icsk->icsk_af_ops = &ipv6_mapped;
 213                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 214 #ifdef CONFIG_TCP_MD5SIG
 215                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 216 #endif
 217
 218                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 219
 220                 if (err) {
 221                         icsk->icsk_ext_hdr_len = exthdrlen;
 222                         icsk->icsk_af_ops = &ipv6_specific;
 223                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 224 #ifdef CONFIG_TCP_MD5SIG
 225                         tp->af_specific = &tcp_sock_ipv6_specific;
 226 #endif
 227                         goto failure;
 228                 } else {
 229                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
 230                                       inet->saddr);
 231                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
 232                                       inet->rcv_saddr);
 233                 }
 234
 235                 return err;
 236         }
 237
 238         if (!ipv6_addr_any(&np->rcv_saddr))
 239                 saddr = &np->rcv_saddr;
 240
 241         fl.proto = IPPROTO_TCP;
 242         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 243         ipv6_addr_copy(&fl.fl6_src,
 244                        (saddr ? saddr : &np->saddr));
 245         fl.oif = sk->sk_bound_dev_if;
 246         fl.fl_ip_dport = usin->sin6_port;
 247         fl.fl_ip_sport = inet->sport;
 248
 249         if (np->opt && np->opt->srcrt) {
 250                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 251                 ipv6_addr_copy(&final, &fl.fl6_dst);
 252                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 253                 final_p = &final;
 254         }
 255
 256         security_sk_classify_flow(sk, &fl);
 257
 258         err = ip6_dst_lookup(sk, &dst, &fl);
 259         if (err)
 260                 goto failure;
 261         if (final_p)
 262                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 263
 264         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 265         if (err < 0) {
 266                 if (err == -EREMOTE)
 267                         err = ip6_dst_blackhole(sk, &dst, &fl);
 268                 if (err < 0)
 269                         goto failure;
 270         }
 271
 272         if (saddr == NULL) {
 273                 saddr = &fl.fl6_src;
 274                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 275         }
 276
 277         /* set the source address */
 278         ipv6_addr_copy(&np->saddr, saddr);
 279         inet->rcv_saddr = LOOPBACK4_IPV6;
 280
 281         sk->sk_gso_type = SKB_GSO_TCPV6;
 282         __ip6_dst_store(sk, dst, NULL, NULL);
 283
 284         icsk->icsk_ext_hdr_len = 0;
 285         if (np->opt)
 286                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 287                                           np->opt->opt_nflen);
 288
 289         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 290
 291         inet->dport = usin->sin6_port;
 292
 293         tcp_set_state(sk, TCP_SYN_SENT);
 294         err = inet6_hash_connect(&tcp_death_row, sk);
 295         if (err)
 296                 goto late_failure;
 297
 298         if (!tp->write_seq)
 299                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 300                                                              np->daddr.s6_addr32,
 301                                                              inet->sport,
 302                                                              inet->dport);
 303
 304         err = tcp_connect(sk);
 305         if (err)
 306                 goto late_failure;
 307
 308         return 0;
 309
 310 late_failure:
 311         tcp_set_state(sk, TCP_CLOSE);
 312         __sk_dst_reset(sk);
 313 failure:
 314         inet->dport = 0;
 315         sk->sk_route_caps = 0;
 316         return err;
 317 }
 318
 319 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 320                 int type, int code, int offset, __be32 info)
 321 {
 322         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
 323         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 324         struct ipv6_pinfo *np;
 325         struct sock *sk;
 326         int err;
 327         struct tcp_sock *tp;
 328         __u32 seq;
 329         struct net *net = dev_net(skb->dev);
 330
 331         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
 332                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 333
 334         if (sk == NULL) {
 335                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 336                                    ICMP6_MIB_INERRORS);
 337                 return;
 338         }
 339
 340         if (sk->sk_state == TCP_TIME_WAIT) {
 341                 inet_twsk_put(inet_twsk(sk));
 342                 return;
 343         }
 344
 345         bh_lock_sock(sk);
 346         if (sock_owned_by_user(sk))
 347                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 348
 349         if (sk->sk_state == TCP_CLOSE)
 350                 goto out;
 351
 352         tp = tcp_sk(sk);
 353         seq = ntohl(th->seq);
 354         if (sk->sk_state != TCP_LISTEN &&
 355             !between(seq, tp->snd_una, tp->snd_nxt)) {
 356                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 357                 goto out;
 358         }
 359
 360         np = inet6_sk(sk);
 361
 362         if (type == ICMPV6_PKT_TOOBIG) {
 363                 struct dst_entry *dst = NULL;
 364
 365                 if (sock_owned_by_user(sk))
 366                         goto out;
 367                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 368                         goto out;
 369
 370                 /* icmp should have updated the destination cache entry */
 371                 dst = __sk_dst_check(sk, np->dst_cookie);
 372
 373                 if (dst == NULL) {
 374                         struct inet_sock *inet = inet_sk(sk);
 375                         struct flowi fl;
 376
 377                         /* BUGGG_FUTURE: Again, it is not clear how
 378                            to handle rthdr case. Ignore this complexity
 379                            for now.
 380                          */
 381                         memset(&fl, 0, sizeof(fl));
 382                         fl.proto = IPPROTO_TCP;
 383                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 384                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 385                         fl.oif = sk->sk_bound_dev_if;
 386                         fl.fl_ip_dport = inet->dport;
 387                         fl.fl_ip_sport = inet->sport;
 388                         security_skb_classify_flow(skb, &fl);
 389
 390                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
 391                                 sk->sk_err_soft = -err;
 392                                 goto out;
 393                         }
 394
 395                         if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) {
 396                                 sk->sk_err_soft = -err;
 397                                 goto out;
 398                         }
 399
 400                 } else
 401                         dst_hold(dst);
 402
 403                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 404                         tcp_sync_mss(sk, dst_mtu(dst));
 405                         tcp_simple_retransmit(sk);
 406                 } /* else let the usual retransmit timer handle it */
 407                 dst_release(dst);
 408                 goto out;
 409         }
 410
 411         icmpv6_err_convert(type, code, &err);
 412
 413         /* Might be for an request_sock */
 414         switch (sk->sk_state) {
 415                 struct request_sock *req, **prev;
 416         case TCP_LISTEN:
 417                 if (sock_owned_by_user(sk))
 418                         goto out;
 419
 420                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 421                                            &hdr->saddr, inet6_iif(skb));
 422                 if (!req)
 423                         goto out;
 424
 425                 /* ICMPs are not backlogged, hence we cannot get
 426                  * an established socket here.
 427                  */
 428                 WARN_ON(req->sk != NULL);
 429
 430                 if (seq != tcp_rsk(req)->snt_isn) {
 431                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 432                         goto out;
 433                 }
 434
 435                 inet_csk_reqsk_queue_drop(sk, req, prev);
 436                 goto out;
 437
 438         case TCP_SYN_SENT:
 439         case TCP_SYN_RECV:  /* Cannot happen.
 440                                It can, it SYNs are crossed. --ANK */
 441                 if (!sock_owned_by_user(sk)) {
 442                         sk->sk_err = err;
 443                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 444
 445                         tcp_done(sk);
 446                 } else
 447                         sk->sk_err_soft = err;
 448                 goto out;
 449         }
 450
 451         if (!sock_owned_by_user(sk) && np->recverr) {
 452                 sk->sk_err = err;
 453                 sk->sk_error_report(sk);
 454         } else
 455                 sk->sk_err_soft = err;
 456
 457 out:
 458         bh_unlock_sock(sk);
 459         sock_put(sk);
 460 }
 461
 462
 463 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
 464 {
 465         struct inet6_request_sock *treq = inet6_rsk(req);
 466         struct ipv6_pinfo *np = inet6_sk(sk);
 467         struct sk_buff * skb;
 468         struct ipv6_txoptions *opt = NULL;
 469         struct in6_addr * final_p = NULL, final;
 470         struct flowi fl;
 471         struct dst_entry *dst;
 472         int err = -1;
 473
 474         memset(&fl, 0, sizeof(fl));
 475         fl.proto = IPPROTO_TCP;
 476         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 477         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
 478         fl.fl6_flowlabel = 0;
 479         fl.oif = treq->iif;
 480         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
 481         fl.fl_ip_sport = inet_rsk(req)->loc_port;
 482         security_req_classify_flow(req, &fl);
 483
 484         opt = np->opt;
 485         if (opt && opt->srcrt) {
 486                 struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
 487                 ipv6_addr_copy(&final, &fl.fl6_dst);
 488                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 489                 final_p = &final;
 490         }
 491
 492         err = ip6_dst_lookup(sk, &dst, &fl);
 493         if (err)
 494                 goto done;
 495         if (final_p)
 496                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 497         if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
 498                 goto done;
 499
 500         skb = tcp_make_synack(sk, dst, req);
 501         if (skb) {
 502                 struct tcphdr *th = tcp_hdr(skb);
 503
 504                 th->check = tcp_v6_check(skb->len,
 505                                          &treq->loc_addr, &treq->rmt_addr,
 506                                          csum_partial(th, skb->len, skb->csum));
 507
 508                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 509                 err = ip6_xmit(sk, skb, &fl, opt, 0);
 510                 err = net_xmit_eval(err);
 511         }
 512
 513 done:
 514         if (opt && opt != np->opt)
 515                 sock_kfree_s(sk, opt, opt->tot_len);
 516         dst_release(dst);
 517         return err;
 518 }
 519
 520 static inline void syn_flood_warning(struct sk_buff *skb)
 521 {
 522 #ifdef CONFIG_SYN_COOKIES
 523         if (sysctl_tcp_syncookies)
 524                 printk(KERN_INFO
 525                        "TCPv6: Possible SYN flooding on port %d. "
 526                        "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
 527         else
 528 #endif
 529                 printk(KERN_INFO
 530                        "TCPv6: Possible SYN flooding on port %d. "
 531                        "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
 532 }
 533
 534 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 535 {
 536         kfree_skb(inet6_rsk(req)->pktopts);
 537 }
 538
 539 #ifdef CONFIG_TCP_MD5SIG
 540 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 541                                                    struct in6_addr *addr)
 542 {
 543         struct tcp_sock *tp = tcp_sk(sk);
 544         int i;
 545
 546         BUG_ON(tp == NULL);
 547
 548         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 549                 return NULL;
 550
 551         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 552                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
 553                         return &tp->md5sig_info->keys6[i].base;
 554         }
 555         return NULL;
 556 }
 557
 558 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 559                                                 struct sock *addr_sk)
 560 {
 561         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 562 }
 563
 564 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 565                                                       struct request_sock *req)
 566 {
 567         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 568 }
 569
 570 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
 571                              char *newkey, u8 newkeylen)
 572 {
 573         /* Add key to the list */
 574         struct tcp_md5sig_key *key;
 575         struct tcp_sock *tp = tcp_sk(sk);
 576         struct tcp6_md5sig_key *keys;
 577
 578         key = tcp_v6_md5_do_lookup(sk, peer);
 579         if (key) {
 580                 /* modify existing entry - just update that one */
 581                 kfree(key->key);
 582                 key->key = newkey;
 583                 key->keylen = newkeylen;
 584         } else {
 585                 /* reallocate new list if current one is full. */
 586                 if (!tp->md5sig_info) {
 587                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 588                         if (!tp->md5sig_info) {
 589                                 kfree(newkey);
 590                                 return -ENOMEM;
 591                         }
 592                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 593                 }
 594                 if (tcp_alloc_md5sig_pool() == NULL) {
 595                         kfree(newkey);
 596                         return -ENOMEM;
 597                 }
 598                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 599                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 600                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 601
 602                         if (!keys) {
 603                                 tcp_free_md5sig_pool();
 604                                 kfree(newkey);
 605                                 return -ENOMEM;
 606                         }
 607
 608                         if (tp->md5sig_info->entries6)
 609                                 memmove(keys, tp->md5sig_info->keys6,
 610                                         (sizeof (tp->md5sig_info->keys6[0]) *
 611                                          tp->md5sig_info->entries6));
 612
 613                         kfree(tp->md5sig_info->keys6);
 614                         tp->md5sig_info->keys6 = keys;
 615                         tp->md5sig_info->alloced6++;
 616                 }
 617
 618                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 619                                peer);
 620                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
 621                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
 622
 623                 tp->md5sig_info->entries6++;
 624         }
 625         return 0;
 626 }
 627
 628 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 629                                u8 *newkey, __u8 newkeylen)
 630 {
 631         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 632                                  newkey, newkeylen);
 633 }
 634
 635 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 636 {
 637         struct tcp_sock *tp = tcp_sk(sk);
 638         int i;
 639
 640         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 641                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
 642                         /* Free the key */
 643                         kfree(tp->md5sig_info->keys6[i].base.key);
 644                         tp->md5sig_info->entries6--;
 645
 646                         if (tp->md5sig_info->entries6 == 0) {
 647                                 kfree(tp->md5sig_info->keys6);
 648                                 tp->md5sig_info->keys6 = NULL;
 649                                 tp->md5sig_info->alloced6 = 0;
 650                         } else {
 651                                 /* shrink the database */
 652                                 if (tp->md5sig_info->entries6 != i)
 653                                         memmove(&tp->md5sig_info->keys6[i],
 654                                                 &tp->md5sig_info->keys6[i+1],
 655                                                 (tp->md5sig_info->entries6 - i)
 656                                                 * sizeof (tp->md5sig_info->keys6[0]));
 657                         }
 658                         tcp_free_md5sig_pool();
 659                         return 0;
 660                 }
 661         }
 662         return -ENOENT;
 663 }
 664
 665 static void tcp_v6_clear_md5_list (struct sock *sk)
 666 {
 667         struct tcp_sock *tp = tcp_sk(sk);
 668         int i;
 669
 670         if (tp->md5sig_info->entries6) {
 671                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 672                         kfree(tp->md5sig_info->keys6[i].base.key);
 673                 tp->md5sig_info->entries6 = 0;
 674                 tcp_free_md5sig_pool();
 675         }
 676
 677         kfree(tp->md5sig_info->keys6);
 678         tp->md5sig_info->keys6 = NULL;
 679         tp->md5sig_info->alloced6 = 0;
 680
 681         if (tp->md5sig_info->entries4) {
 682                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 683                         kfree(tp->md5sig_info->keys4[i].base.key);
 684                 tp->md5sig_info->entries4 = 0;
 685                 tcp_free_md5sig_pool();
 686         }
 687
 688         kfree(tp->md5sig_info->keys4);
 689         tp->md5sig_info->keys4 = NULL;
 690         tp->md5sig_info->alloced4 = 0;
 691 }
 692
 693 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 694                                   int optlen)
 695 {
 696         struct tcp_md5sig cmd;
 697         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 698         u8 *newkey;
 699
 700         if (optlen < sizeof(cmd))
 701                 return -EINVAL;
 702
 703         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 704                 return -EFAULT;
 705
 706         if (sin6->sin6_family != AF_INET6)
 707                 return -EINVAL;
 708
 709         if (!cmd.tcpm_keylen) {
 710                 if (!tcp_sk(sk)->md5sig_info)
 711                         return -ENOENT;
 712                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 713                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 714                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 715         }
 716
 717         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 718                 return -EINVAL;
 719
 720         if (!tcp_sk(sk)->md5sig_info) {
 721                 struct tcp_sock *tp = tcp_sk(sk);
 722                 struct tcp_md5sig_info *p;
 723
 724                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 725                 if (!p)
 726                         return -ENOMEM;
 727
 728                 tp->md5sig_info = p;
 729                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 730         }
 731
 732         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 733         if (!newkey)
 734                 return -ENOMEM;
 735         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 736                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 737                                          newkey, cmd.tcpm_keylen);
 738         }
 739         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 740 }
 741
 742 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 743                                         struct in6_addr *daddr,
 744                                         struct in6_addr *saddr, int nbytes)
 745 {
 746         struct tcp6_pseudohdr *bp;
 747         struct scatterlist sg;
 748
 749         bp = &hp->md5_blk.ip6;
 750         /* 1. TCP pseudo-header (RFC2460) */
 751         ipv6_addr_copy(&bp->saddr, saddr);
 752         ipv6_addr_copy(&bp->daddr, daddr);
 753         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 754         bp->len = cpu_to_be32(nbytes);
 755
 756         sg_init_one(&sg, bp, sizeof(*bp));
 757         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 758 }
 759
 760 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 761                                struct in6_addr *daddr, struct in6_addr *saddr,
 762                                struct tcphdr *th)
 763 {
 764         struct tcp_md5sig_pool *hp;
 765         struct hash_desc *desc;
 766
 767         hp = tcp_get_md5sig_pool();
 768         if (!hp)
 769                 goto clear_hash_noput;
 770         desc = &hp->md5_desc;
 771
 772         if (crypto_hash_init(desc))
 773                 goto clear_hash;
 774         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 775                 goto clear_hash;
 776         if (tcp_md5_hash_header(hp, th))
 777                 goto clear_hash;
 778         if (tcp_md5_hash_key(hp, key))
 779                 goto clear_hash;
 780         if (crypto_hash_final(desc, md5_hash))
 781                 goto clear_hash;
 782
 783         tcp_put_md5sig_pool();
 784         return 0;
 785
 786 clear_hash:
 787         tcp_put_md5sig_pool();
 788 clear_hash_noput:
 789         memset(md5_hash, 0, 16);
 790         return 1;
 791 }
 792
 793 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 794                                struct sock *sk, struct request_sock *req,
 795                                struct sk_buff *skb)
 796 {
 797         struct in6_addr *saddr, *daddr;
 798         struct tcp_md5sig_pool *hp;
 799         struct hash_desc *desc;
 800         struct tcphdr *th = tcp_hdr(skb);
 801
 802         if (sk) {
 803                 saddr = &inet6_sk(sk)->saddr;
 804                 daddr = &inet6_sk(sk)->daddr;
 805         } else if (req) {
 806                 saddr = &inet6_rsk(req)->loc_addr;
 807                 daddr = &inet6_rsk(req)->rmt_addr;
 808         } else {
 809                 struct ipv6hdr *ip6h = ipv6_hdr(skb);
 810                 saddr = &ip6h->saddr;
 811                 daddr = &ip6h->daddr;
 812         }
 813
 814         hp = tcp_get_md5sig_pool();
 815         if (!hp)
 816                 goto clear_hash_noput;
 817         desc = &hp->md5_desc;
 818
 819         if (crypto_hash_init(desc))
 820                 goto clear_hash;
 821
 822         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 823                 goto clear_hash;
 824         if (tcp_md5_hash_header(hp, th))
 825                 goto clear_hash;
 826         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 827                 goto clear_hash;
 828         if (tcp_md5_hash_key(hp, key))
 829                 goto clear_hash;
 830         if (crypto_hash_final(desc, md5_hash))
 831                 goto clear_hash;
 832
 833         tcp_put_md5sig_pool();
 834         return 0;
 835
 836 clear_hash:
 837         tcp_put_md5sig_pool();
 838 clear_hash_noput:
 839         memset(md5_hash, 0, 16);
 840         return 1;
 841 }
 842
 843 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 844 {
 845         __u8 *hash_location = NULL;
 846         struct tcp_md5sig_key *hash_expected;
 847         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 848         struct tcphdr *th = tcp_hdr(skb);
 849         int genhash;
 850         u8 newhash[16];
 851
 852         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 853         hash_location = tcp_parse_md5sig_option(th);
 854
 855         /* We've parsed the options - do we have a hash? */
 856         if (!hash_expected && !hash_location)
 857                 return 0;
 858
 859         if (hash_expected && !hash_location) {
 860                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 861                 return 1;
 862         }
 863
 864         if (!hash_expected && hash_location) {
 865                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 866                 return 1;
 867         }
 868
 869         /* check the signature */
 870         genhash = tcp_v6_md5_hash_skb(newhash,
 871                                       hash_expected,
 872                                       NULL, NULL, skb);
 873
 874         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 875                 if (net_ratelimit()) {
 876                         printk(KERN_INFO "MD5 Hash %s for (%pI6, %u)->(%pI6, %u)\n",
 877                                genhash ? "failed" : "mismatch",
 878                                &ip6h->saddr, ntohs(th->source),
 879                                &ip6h->daddr, ntohs(th->dest));
 880                 }
 881                 return 1;
 882         }
 883         return 0;
 884 }
 885 #endif
 886
 887 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 888         .family         =       AF_INET6,
 889         .obj_size       =       sizeof(struct tcp6_request_sock),
 890         .rtx_syn_ack    =       tcp_v6_send_synack,
 891         .send_ack       =       tcp_v6_reqsk_send_ack,
 892         .destructor     =       tcp_v6_reqsk_destructor,
 893         .send_reset     =       tcp_v6_send_reset
 894 };
 895
 896 #ifdef CONFIG_TCP_MD5SIG
 897 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 898         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 899 };
 900 #endif
 901
 902 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 903         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 904         .twsk_unique    = tcp_twsk_unique,
 905         .twsk_destructor= tcp_twsk_destructor,
 906 };
 907
 908 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 909 {
 910         struct ipv6_pinfo *np = inet6_sk(sk);
 911         struct tcphdr *th = tcp_hdr(skb);
 912
 913         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 914                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 915                 skb->csum_start = skb_transport_header(skb) - skb->head;
 916                 skb->csum_offset = offsetof(struct tcphdr, check);
 917         } else {
 918                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 919                                             csum_partial(th, th->doff<<2,
 920                                                          skb->csum));
 921         }
 922 }
 923
 924 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 925 {
 926         struct ipv6hdr *ipv6h;
 927         struct tcphdr *th;
 928
 929         if (!pskb_may_pull(skb, sizeof(*th)))
 930                 return -EINVAL;
 931
 932         ipv6h = ipv6_hdr(skb);
 933         th = tcp_hdr(skb);
 934
 935         th->check = 0;
 936         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 937                                      IPPROTO_TCP, 0);
 938         skb->csum_start = skb_transport_header(skb) - skb->head;
 939         skb->csum_offset = offsetof(struct tcphdr, check);
 940         skb->ip_summed = CHECKSUM_PARTIAL;
 941         return 0;
 942 }
 943
 944 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
 945                                          struct sk_buff *skb)
 946 {
 947         struct ipv6hdr *iph = skb_gro_network_header(skb);
 948
 949         switch (skb->ip_summed) {
 950         case CHECKSUM_COMPLETE:
 951                 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
 952                                   skb->csum)) {
 953                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 954                         break;
 955                 }
 956
 957                 /* fall through */
 958         case CHECKSUM_NONE:
 959                 NAPI_GRO_CB(skb)->flush = 1;
 960                 return NULL;
 961         }
 962
 963         return tcp_gro_receive(head, skb);
 964 }
 965
 966 static int tcp6_gro_complete(struct sk_buff *skb)
 967 {
 968         struct ipv6hdr *iph = ipv6_hdr(skb);
 969         struct tcphdr *th = tcp_hdr(skb);
 970
 971         th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
 972                                   &iph->saddr, &iph->daddr, 0);
 973         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 974
 975         return tcp_gro_complete(skb);
 976 }
 977
 978 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
 979                                  u32 ts, struct tcp_md5sig_key *key, int rst)
 980 {
 981         struct tcphdr *th = tcp_hdr(skb), *t1;
 982         struct sk_buff *buff;
 983         struct flowi fl;
 984         struct net *net = dev_net(skb->dst->dev);
 985         struct sock *ctl_sk = net->ipv6.tcp_sk;
 986         unsigned int tot_len = sizeof(struct tcphdr);
 987         __be32 *topt;
 988
 989         if (ts)
 990                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 991 #ifdef CONFIG_TCP_MD5SIG
 992         if (key)
 993                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 994 #endif
 995
 996         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 997                          GFP_ATOMIC);
 998         if (buff == NULL)
 999                 return;
1000
1001         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1002
1003         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1004
1005         /* Swap the send and the receive. */
1006         memset(t1, 0, sizeof(*t1));
1007         t1->dest = th->source;
1008         t1->source = th->dest;
1009         t1->doff = tot_len / 4;
1010         t1->seq = htonl(seq);
1011         t1->ack_seq = htonl(ack);
1012         t1->ack = !rst || !th->ack;
1013         t1->rst = rst;
1014         t1->window = htons(win);
1015
1016         topt = (__be32 *)(t1 + 1);
1017
1018         if (ts) {
1019                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1020                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1021                 *topt++ = htonl(tcp_time_stamp);
1022                 *topt++ = htonl(ts);
1023         }
1024
1025 #ifdef CONFIG_TCP_MD5SIG
1026         if (key) {
1027                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1028                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1029                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1030                                     &ipv6_hdr(skb)->saddr,
1031                                     &ipv6_hdr(skb)->daddr, t1);
1032         }
1033 #endif
1034
1035         buff->csum = csum_partial(t1, tot_len, 0);
1036
1037         memset(&fl, 0, sizeof(fl));
1038         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1039         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1040
1041         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1042                                     tot_len, IPPROTO_TCP,
1043                                     buff->csum);
1044
1045         fl.proto = IPPROTO_TCP;
1046         fl.oif = inet6_iif(skb);
1047         fl.fl_ip_dport = t1->dest;
1048         fl.fl_ip_sport = t1->source;
1049         security_skb_classify_flow(skb, &fl);
1050
1051         /* Pass a socket to ip6_dst_lookup either it is for RST
1052          * Underlying function will use this to retrieve the network
1053          * namespace
1054          */
1055         if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
1056                 if (xfrm_lookup(net, &buff->dst, &fl, NULL, 0) >= 0) {
1057                         ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1058                         TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1059                         if (rst)
1060                                 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1061                         return;
1062                 }
1063         }
1064
1065         kfree_skb(buff);
1066 }
1067
1068 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1069 {
1070         struct tcphdr *th = tcp_hdr(skb);
1071         u32 seq = 0, ack_seq = 0;
1072         struct tcp_md5sig_key *key = NULL;
1073
1074         if (th->rst)
1075                 return;
1076
1077         if (!ipv6_unicast_destination(skb))
1078                 return;
1079
1080 #ifdef CONFIG_TCP_MD5SIG
1081         if (sk)
1082                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1083 #endif
1084
1085         if (th->ack)
1086                 seq = ntohl(th->ack_seq);
1087         else
1088                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1089                           (th->doff << 2);
1090
1091         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1092 }
1093
1094 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1095                             struct tcp_md5sig_key *key)
1096 {
1097         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1098 }
1099
1100 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1101 {
1102         struct inet_timewait_sock *tw = inet_twsk(sk);
1103         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1104
1105         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1106                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1107                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1108
1109         inet_twsk_put(tw);
1110 }
1111
1112 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1113                                   struct request_sock *req)
1114 {
1115         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1116                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1117 }
1118
1119
1120 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1121 {
1122         struct request_sock *req, **prev;
1123         const struct tcphdr *th = tcp_hdr(skb);
1124         struct sock *nsk;
1125
1126         /* Find possible connection requests. */
1127         req = inet6_csk_search_req(sk, &prev, th->source,
1128                                    &ipv6_hdr(skb)->saddr,
1129                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1130         if (req)
1131                 return tcp_check_req(sk, skb, req, prev);
1132
1133         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1134                         &ipv6_hdr(skb)->saddr, th->source,
1135                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1136
1137         if (nsk) {
1138                 if (nsk->sk_state != TCP_TIME_WAIT) {
1139                         bh_lock_sock(nsk);
1140                         return nsk;
1141                 }
1142                 inet_twsk_put(inet_twsk(nsk));
1143                 return NULL;
1144         }
1145
1146 #ifdef CONFIG_SYN_COOKIES
1147         if (!th->rst && !th->syn && th->ack)
1148                 sk = cookie_v6_check(sk, skb);
1149 #endif
1150         return sk;
1151 }
1152
1153 /* FIXME: this is substantially similar to the ipv4 code.
1154  * Can some kind of merge be done? -- erics
1155  */
1156 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1157 {
1158         struct inet6_request_sock *treq;
1159         struct ipv6_pinfo *np = inet6_sk(sk);
1160         struct tcp_options_received tmp_opt;
1161         struct tcp_sock *tp = tcp_sk(sk);
1162         struct request_sock *req = NULL;
1163         __u32 isn = TCP_SKB_CB(skb)->when;
1164 #ifdef CONFIG_SYN_COOKIES
1165         int want_cookie = 0;
1166 #else
1167 #define want_cookie 0
1168 #endif
1169
1170         if (skb->protocol == htons(ETH_P_IP))
1171                 return tcp_v4_conn_request(sk, skb);
1172
1173         if (!ipv6_unicast_destination(skb))
1174                 goto drop;
1175
1176         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1177                 if (net_ratelimit())
1178                         syn_flood_warning(skb);
1179 #ifdef CONFIG_SYN_COOKIES
1180                 if (sysctl_tcp_syncookies)
1181                         want_cookie = 1;
1182                 else
1183 #endif
1184                 goto drop;
1185         }
1186
1187         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1188                 goto drop;
1189
1190         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1191         if (req == NULL)
1192                 goto drop;
1193
1194 #ifdef CONFIG_TCP_MD5SIG
1195         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1196 #endif
1197
1198         tcp_clear_options(&tmp_opt);
1199         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1200         tmp_opt.user_mss = tp->rx_opt.user_mss;
1201
1202         tcp_parse_options(skb, &tmp_opt, 0);
1203
1204         if (want_cookie && !tmp_opt.saw_tstamp)
1205                 tcp_clear_options(&tmp_opt);
1206
1207         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1208         tcp_openreq_init(req, &tmp_opt, skb);
1209
1210         treq = inet6_rsk(req);
1211         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1212         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1213         if (!want_cookie)
1214                 TCP_ECN_create_request(req, tcp_hdr(skb));
1215
1216         if (want_cookie) {
1217                 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1218                 req->cookie_ts = tmp_opt.tstamp_ok;
1219         } else if (!isn) {
1220                 if (ipv6_opt_accepted(sk, skb) ||
1221                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1222                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1223                         atomic_inc(&skb->users);
1224                         treq->pktopts = skb;
1225                 }
1226                 treq->iif = sk->sk_bound_dev_if;
1227
1228                 /* So that link locals have meaning */
1229                 if (!sk->sk_bound_dev_if &&
1230                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1231                         treq->iif = inet6_iif(skb);
1232
1233                 isn = tcp_v6_init_sequence(skb);
1234         }
1235
1236         tcp_rsk(req)->snt_isn = isn;
1237
1238         security_inet_conn_request(sk, skb, req);
1239
1240         if (tcp_v6_send_synack(sk, req))
1241                 goto drop;
1242
1243         if (!want_cookie) {
1244                 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1245                 return 0;
1246         }
1247
1248 drop:
1249         if (req)
1250                 reqsk_free(req);
1251
1252         return 0; /* don't send reset */
1253 }
1254
1255 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1256                                           struct request_sock *req,
1257                                           struct dst_entry *dst)
1258 {
1259         struct inet6_request_sock *treq;
1260         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1261         struct tcp6_sock *newtcp6sk;
1262         struct inet_sock *newinet;
1263         struct tcp_sock *newtp;
1264         struct sock *newsk;
1265         struct ipv6_txoptions *opt;
1266 #ifdef CONFIG_TCP_MD5SIG
1267         struct tcp_md5sig_key *key;
1268 #endif
1269
1270         if (skb->protocol == htons(ETH_P_IP)) {
1271                 /*
1272                  *      v6 mapped
1273                  */
1274
1275                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1276
1277                 if (newsk == NULL)
1278                         return NULL;
1279
1280                 newtcp6sk = (struct tcp6_sock *)newsk;
1281                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1282
1283                 newinet = inet_sk(newsk);
1284                 newnp = inet6_sk(newsk);
1285                 newtp = tcp_sk(newsk);
1286
1287                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1288
1289                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1290                               newinet->daddr);
1291
1292                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1293                               newinet->saddr);
1294
1295                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1296
1297                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1298                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1299 #ifdef CONFIG_TCP_MD5SIG
1300                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1301 #endif
1302
1303                 newnp->pktoptions  = NULL;
1304                 newnp->opt         = NULL;
1305                 newnp->mcast_oif   = inet6_iif(skb);
1306                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1307
1308                 /*
1309                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1310                  * here, tcp_create_openreq_child now does this for us, see the comment in
1311                  * that function for the gory details. -acme
1312                  */
1313
1314                 /* It is tricky place. Until this moment IPv4 tcp
1315                    worked with IPv6 icsk.icsk_af_ops.
1316                    Sync it now.
1317                  */
1318                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1319
1320                 return newsk;
1321         }
1322
1323         treq = inet6_rsk(req);
1324         opt = np->opt;
1325
1326         if (sk_acceptq_is_full(sk))
1327                 goto out_overflow;
1328
1329         if (dst == NULL) {
1330                 struct in6_addr *final_p = NULL, final;
1331                 struct flowi fl;
1332
1333                 memset(&fl, 0, sizeof(fl));
1334                 fl.proto = IPPROTO_TCP;
1335                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1336                 if (opt && opt->srcrt) {
1337                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1338                         ipv6_addr_copy(&final, &fl.fl6_dst);
1339                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1340                         final_p = &final;
1341                 }
1342                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1343                 fl.oif = sk->sk_bound_dev_if;
1344                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1345                 fl.fl_ip_sport = inet_rsk(req)->loc_port;
1346                 security_req_classify_flow(req, &fl);
1347
1348                 if (ip6_dst_lookup(sk, &dst, &fl))
1349                         goto out;
1350
1351                 if (final_p)
1352                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1353
1354                 if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
1355                         goto out;
1356         }
1357
1358         newsk = tcp_create_openreq_child(sk, req, skb);
1359         if (newsk == NULL)
1360                 goto out;
1361
1362         /*
1363          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1364          * count here, tcp_create_openreq_child now does this for us, see the
1365          * comment in that function for the gory details. -acme
1366          */
1367
1368         newsk->sk_gso_type = SKB_GSO_TCPV6;
1369         __ip6_dst_store(newsk, dst, NULL, NULL);
1370
1371         newtcp6sk = (struct tcp6_sock *)newsk;
1372         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1373
1374         newtp = tcp_sk(newsk);
1375         newinet = inet_sk(newsk);
1376         newnp = inet6_sk(newsk);
1377
1378         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1379
1380         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1381         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1382         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1383         newsk->sk_bound_dev_if = treq->iif;
1384
1385         /* Now IPv6 options...
1386
1387            First: no IPv4 options.
1388          */
1389         newinet->opt = NULL;
1390         newnp->ipv6_fl_list = NULL;
1391
1392         /* Clone RX bits */
1393         newnp->rxopt.all = np->rxopt.all;
1394
1395         /* Clone pktoptions received with SYN */
1396         newnp->pktoptions = NULL;
1397         if (treq->pktopts != NULL) {
1398                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1399                 kfree_skb(treq->pktopts);
1400                 treq->pktopts = NULL;
1401                 if (newnp->pktoptions)
1402                         skb_set_owner_r(newnp->pktoptions, newsk);
1403         }
1404         newnp->opt        = NULL;
1405         newnp->mcast_oif  = inet6_iif(skb);
1406         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1407
1408         /* Clone native IPv6 options from listening socket (if any)
1409
1410            Yes, keeping reference count would be much more clever,
1411            but we make one more one thing there: reattach optmem
1412            to newsk.
1413          */
1414         if (opt) {
1415                 newnp->opt = ipv6_dup_options(newsk, opt);
1416                 if (opt != np->opt)
1417                         sock_kfree_s(sk, opt, opt->tot_len);
1418         }
1419
1420         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1421         if (newnp->opt)
1422                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1423                                                      newnp->opt->opt_flen);
1424
1425         tcp_mtup_init(newsk);
1426         tcp_sync_mss(newsk, dst_mtu(dst));
1427         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1428         tcp_initialize_rcv_mss(newsk);
1429
1430         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1431
1432 #ifdef CONFIG_TCP_MD5SIG
1433         /* Copy over the MD5 key from the original socket */
1434         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1435                 /* We're using one, so create a matching key
1436                  * on the newsk structure. If we fail to get
1437                  * memory, then we end up not copying the key
1438                  * across. Shucks.
1439                  */
1440                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1441                 if (newkey != NULL)
1442                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1443                                           newkey, key->keylen);
1444         }
1445 #endif
1446
1447         __inet6_hash(newsk);
1448         __inet_inherit_port(sk, newsk);
1449
1450         return newsk;
1451
1452 out_overflow:
1453         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1454 out:
1455         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1456         if (opt && opt != np->opt)
1457                 sock_kfree_s(sk, opt, opt->tot_len);
1458         dst_release(dst);
1459         return NULL;
1460 }
1461
1462 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1463 {
1464         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1465                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1466                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1467                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1468                         return 0;
1469                 }
1470         }
1471
1472         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1473                                               &ipv6_hdr(skb)->saddr,
1474                                               &ipv6_hdr(skb)->daddr, 0));
1475
1476         if (skb->len <= 76) {
1477                 return __skb_checksum_complete(skb);
1478         }
1479         return 0;
1480 }
1481
1482 /* The socket must have it's spinlock held when we get
1483  * here.
1484  *
1485  * We have a potential double-lock case here, so even when
1486  * doing backlog processing we use the BH locking scheme.
1487  * This is because we cannot sleep with the original spinlock
1488  * held.
1489  */
1490 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1491 {
1492         struct ipv6_pinfo *np = inet6_sk(sk);
1493         struct tcp_sock *tp;
1494         struct sk_buff *opt_skb = NULL;
1495
1496         /* Imagine: socket is IPv6. IPv4 packet arrives,
1497            goes to IPv4 receive handler and backlogged.
1498            From backlog it always goes here. Kerboom...
1499            Fortunately, tcp_rcv_established and rcv_established
1500            handle them correctly, but it is not case with
1501            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1502          */
1503
1504         if (skb->protocol == htons(ETH_P_IP))
1505                 return tcp_v4_do_rcv(sk, skb);
1506
1507 #ifdef CONFIG_TCP_MD5SIG
1508         if (tcp_v6_inbound_md5_hash (sk, skb))
1509                 goto discard;
1510 #endif
1511
1512         if (sk_filter(sk, skb))
1513                 goto discard;
1514
1515         /*
1516          *      socket locking is here for SMP purposes as backlog rcv
1517          *      is currently called with bh processing disabled.
1518          */
1519
1520         /* Do Stevens' IPV6_PKTOPTIONS.
1521
1522            Yes, guys, it is the only place in our code, where we
1523            may make it not affecting IPv4.
1524            The rest of code is protocol independent,
1525            and I do not like idea to uglify IPv4.
1526
1527            Actually, all the idea behind IPV6_PKTOPTIONS
1528            looks not very well thought. For now we latch
1529            options, received in the last packet, enqueued
1530            by tcp. Feel free to propose better solution.
1531                                                --ANK (980728)
1532          */
1533         if (np->rxopt.all)
1534                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1535
1536         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1537                 TCP_CHECK_TIMER(sk);
1538                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1539                         goto reset;
1540                 TCP_CHECK_TIMER(sk);
1541                 if (opt_skb)
1542                         goto ipv6_pktoptions;
1543                 return 0;
1544         }
1545
1546         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1547                 goto csum_err;
1548
1549         if (sk->sk_state == TCP_LISTEN) {
1550                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1551                 if (!nsk)
1552                         goto discard;
1553
1554                 /*
1555                  * Queue it on the new socket if the new socket is active,
1556                  * otherwise we just shortcircuit this and continue with
1557                  * the new socket..
1558                  */
1559                 if(nsk != sk) {
1560                         if (tcp_child_process(sk, nsk, skb))
1561                                 goto reset;
1562                         if (opt_skb)
1563                                 __kfree_skb(opt_skb);
1564                         return 0;
1565                 }
1566         }
1567
1568         TCP_CHECK_TIMER(sk);
1569         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1570                 goto reset;
1571         TCP_CHECK_TIMER(sk);
1572         if (opt_skb)
1573                 goto ipv6_pktoptions;
1574         return 0;
1575
1576 reset:
1577         tcp_v6_send_reset(sk, skb);
1578 discard:
1579         if (opt_skb)
1580                 __kfree_skb(opt_skb);
1581         kfree_skb(skb);
1582         return 0;
1583 csum_err:
1584         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1585         goto discard;
1586
1587
1588 ipv6_pktoptions:
1589         /* Do you ask, what is it?
1590
1591            1. skb was enqueued by tcp.
1592            2. skb is added to tail of read queue, rather than out of order.
1593            3. socket is not in passive state.
1594            4. Finally, it really contains options, which user wants to receive.
1595          */
1596         tp = tcp_sk(sk);
1597         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1598             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1599                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1600                         np->mcast_oif = inet6_iif(opt_skb);
1601                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1602                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1603                 if (ipv6_opt_accepted(sk, opt_skb)) {
1604                         skb_set_owner_r(opt_skb, sk);
1605                         opt_skb = xchg(&np->pktoptions, opt_skb);
1606                 } else {
1607                         __kfree_skb(opt_skb);
1608                         opt_skb = xchg(&np->pktoptions, NULL);
1609                 }
1610         }
1611
1612         kfree_skb(opt_skb);
1613         return 0;
1614 }
1615
1616 static int tcp_v6_rcv(struct sk_buff *skb)
1617 {
1618         struct tcphdr *th;
1619         struct sock *sk;
1620         int ret;
1621         struct net *net = dev_net(skb->dev);
1622
1623         if (skb->pkt_type != PACKET_HOST)
1624                 goto discard_it;
1625
1626         /*
1627          *      Count it even if it's bad.
1628          */
1629         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1630
1631         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1632                 goto discard_it;
1633
1634         th = tcp_hdr(skb);
1635
1636         if (th->doff < sizeof(struct tcphdr)/4)
1637                 goto bad_packet;
1638         if (!pskb_may_pull(skb, th->doff*4))
1639                 goto discard_it;
1640
1641         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1642                 goto bad_packet;
1643
1644         th = tcp_hdr(skb);
1645         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1646         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1647                                     skb->len - th->doff*4);
1648         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1649         TCP_SKB_CB(skb)->when = 0;
1650         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1651         TCP_SKB_CB(skb)->sacked = 0;
1652
1653         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1654         if (!sk)
1655                 goto no_tcp_socket;
1656
1657 process:
1658         if (sk->sk_state == TCP_TIME_WAIT)
1659                 goto do_time_wait;
1660
1661         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1662                 goto discard_and_relse;
1663
1664         if (sk_filter(sk, skb))
1665                 goto discard_and_relse;
1666
1667         skb->dev = NULL;
1668
1669         bh_lock_sock_nested(sk);
1670         ret = 0;
1671         if (!sock_owned_by_user(sk)) {
1672 #ifdef CONFIG_NET_DMA
1673                 struct tcp_sock *tp = tcp_sk(sk);
1674                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1675                         tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1676                 if (tp->ucopy.dma_chan)
1677                         ret = tcp_v6_do_rcv(sk, skb);
1678                 else
1679 #endif
1680                 {
1681                         if (!tcp_prequeue(sk, skb))
1682                                 ret = tcp_v6_do_rcv(sk, skb);
1683                 }
1684         } else
1685                 sk_add_backlog(sk, skb);
1686         bh_unlock_sock(sk);
1687
1688         sock_put(sk);
1689         return ret ? -1 : 0;
1690
1691 no_tcp_socket:
1692         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1693                 goto discard_it;
1694
1695         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1696 bad_packet:
1697                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1698         } else {
1699                 tcp_v6_send_reset(NULL, skb);
1700         }
1701
1702 discard_it:
1703
1704         /*
1705          *      Discard frame
1706          */
1707
1708         kfree_skb(skb);
1709         return 0;
1710
1711 discard_and_relse:
1712         sock_put(sk);
1713         goto discard_it;
1714
1715 do_time_wait:
1716         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1717                 inet_twsk_put(inet_twsk(sk));
1718                 goto discard_it;
1719         }
1720
1721         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1722                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1723                 inet_twsk_put(inet_twsk(sk));
1724                 goto discard_it;
1725         }
1726
1727         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1728         case TCP_TW_SYN:
1729         {
1730                 struct sock *sk2;
1731
1732                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1733                                             &ipv6_hdr(skb)->daddr,
1734                                             ntohs(th->dest), inet6_iif(skb));
1735                 if (sk2 != NULL) {
1736                         struct inet_timewait_sock *tw = inet_twsk(sk);
1737                         inet_twsk_deschedule(tw, &tcp_death_row);
1738                         inet_twsk_put(tw);
1739                         sk = sk2;
1740                         goto process;
1741                 }
1742                 /* Fall through to ACK */
1743         }
1744         case TCP_TW_ACK:
1745                 tcp_v6_timewait_ack(sk, skb);
1746                 break;
1747         case TCP_TW_RST:
1748                 goto no_tcp_socket;
1749         case TCP_TW_SUCCESS:;
1750         }
1751         goto discard_it;
1752 }
1753
1754 static int tcp_v6_remember_stamp(struct sock *sk)
1755 {
1756         /* Alas, not yet... */
1757         return 0;
1758 }
1759
1760 static struct inet_connection_sock_af_ops ipv6_specific = {
1761         .queue_xmit        = inet6_csk_xmit,
1762         .send_check        = tcp_v6_send_check,
1763         .rebuild_header    = inet6_sk_rebuild_header,
1764         .conn_request      = tcp_v6_conn_request,
1765         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1766         .remember_stamp    = tcp_v6_remember_stamp,
1767         .net_header_len    = sizeof(struct ipv6hdr),
1768         .setsockopt        = ipv6_setsockopt,
1769         .getsockopt        = ipv6_getsockopt,
1770         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1771         .sockaddr_len      = sizeof(struct sockaddr_in6),
1772         .bind_conflict     = inet6_csk_bind_conflict,
1773 #ifdef CONFIG_COMPAT
1774         .compat_setsockopt = compat_ipv6_setsockopt,
1775         .compat_getsockopt = compat_ipv6_getsockopt,
1776 #endif
1777 };
1778
1779 #ifdef CONFIG_TCP_MD5SIG
1780 static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1781         .md5_lookup     =       tcp_v6_md5_lookup,
1782         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1783         .md5_add        =       tcp_v6_md5_add_func,
1784         .md5_parse      =       tcp_v6_parse_md5_keys,
1785 };
1786 #endif
1787
1788 /*
1789  *      TCP over IPv4 via INET6 API
1790  */
1791
1792 static struct inet_connection_sock_af_ops ipv6_mapped = {
1793         .queue_xmit        = ip_queue_xmit,
1794         .send_check        = tcp_v4_send_check,
1795         .rebuild_header    = inet_sk_rebuild_header,
1796         .conn_request      = tcp_v6_conn_request,
1797         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1798         .remember_stamp    = tcp_v4_remember_stamp,
1799         .net_header_len    = sizeof(struct iphdr),
1800         .setsockopt        = ipv6_setsockopt,
1801         .getsockopt        = ipv6_getsockopt,
1802         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1803         .sockaddr_len      = sizeof(struct sockaddr_in6),
1804         .bind_conflict     = inet6_csk_bind_conflict,
1805 #ifdef CONFIG_COMPAT
1806         .compat_setsockopt = compat_ipv6_setsockopt,
1807         .compat_getsockopt = compat_ipv6_getsockopt,
1808 #endif
1809 };
1810
1811 #ifdef CONFIG_TCP_MD5SIG
1812 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1813         .md5_lookup     =       tcp_v4_md5_lookup,
1814         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1815         .md5_add        =       tcp_v6_md5_add_func,
1816         .md5_parse      =       tcp_v6_parse_md5_keys,
1817 };
1818 #endif
1819
1820 /* NOTE: A lot of things set to zero explicitly by call to
1821  *       sk_alloc() so need not be done here.
1822  */
1823 static int tcp_v6_init_sock(struct sock *sk)
1824 {
1825         struct inet_connection_sock *icsk = inet_csk(sk);
1826         struct tcp_sock *tp = tcp_sk(sk);
1827
1828         skb_queue_head_init(&tp->out_of_order_queue);
1829         tcp_init_xmit_timers(sk);
1830         tcp_prequeue_init(tp);
1831
1832         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1833         tp->mdev = TCP_TIMEOUT_INIT;
1834
1835         /* So many TCP implementations out there (incorrectly) count the
1836          * initial SYN frame in their delayed-ACK and congestion control
1837          * algorithms that we must have the following bandaid to talk
1838          * efficiently to them.  -DaveM
1839          */
1840         tp->snd_cwnd = 2;
1841
1842         /* See draft-stevens-tcpca-spec-01 for discussion of the
1843          * initialization of these values.
1844          */
1845         tp->snd_ssthresh = 0x7fffffff;
1846         tp->snd_cwnd_clamp = ~0;
1847         tp->mss_cache = 536;
1848
1849         tp->reordering = sysctl_tcp_reordering;
1850
1851         sk->sk_state = TCP_CLOSE;
1852
1853         icsk->icsk_af_ops = &ipv6_specific;
1854         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1855         icsk->icsk_sync_mss = tcp_sync_mss;
1856         sk->sk_write_space = sk_stream_write_space;
1857         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1858
1859 #ifdef CONFIG_TCP_MD5SIG
1860         tp->af_specific = &tcp_sock_ipv6_specific;
1861 #endif
1862
1863         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1864         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1865
1866         local_bh_disable();
1867         percpu_counter_inc(&tcp_sockets_allocated);
1868         local_bh_enable();
1869
1870         return 0;
1871 }
1872
1873 static void tcp_v6_destroy_sock(struct sock *sk)
1874 {
1875 #ifdef CONFIG_TCP_MD5SIG
1876         /* Clean up the MD5 key list */
1877         if (tcp_sk(sk)->md5sig_info)
1878                 tcp_v6_clear_md5_list(sk);
1879 #endif
1880         tcp_v4_destroy_sock(sk);
1881         inet6_destroy_sock(sk);
1882 }
1883
1884 #ifdef CONFIG_PROC_FS
1885 /* Proc filesystem TCPv6 sock list dumping. */
1886 static void get_openreq6(struct seq_file *seq,
1887                          struct sock *sk, struct request_sock *req, int i, int uid)
1888 {
1889         int ttd = req->expires - jiffies;
1890         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1891         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1892
1893         if (ttd < 0)
1894                 ttd = 0;
1895
1896         seq_printf(seq,
1897                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1898                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1899                    i,
1900                    src->s6_addr32[0], src->s6_addr32[1],
1901                    src->s6_addr32[2], src->s6_addr32[3],
1902                    ntohs(inet_rsk(req)->loc_port),
1903                    dest->s6_addr32[0], dest->s6_addr32[1],
1904                    dest->s6_addr32[2], dest->s6_addr32[3],
1905                    ntohs(inet_rsk(req)->rmt_port),
1906                    TCP_SYN_RECV,
1907                    0,0, /* could print option size, but that is af dependent. */
1908                    1,   /* timers active (only the expire timer) */
1909                    jiffies_to_clock_t(ttd),
1910                    req->retrans,
1911                    uid,
1912                    0,  /* non standard timer */
1913                    0, /* open_requests have no inode */
1914                    0, req);
1915 }
1916
1917 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1918 {
1919         struct in6_addr *dest, *src;
1920         __u16 destp, srcp;
1921         int timer_active;
1922         unsigned long timer_expires;
1923         struct inet_sock *inet = inet_sk(sp);
1924         struct tcp_sock *tp = tcp_sk(sp);
1925         const struct inet_connection_sock *icsk = inet_csk(sp);
1926         struct ipv6_pinfo *np = inet6_sk(sp);
1927
1928         dest  = &np->daddr;
1929         src   = &np->rcv_saddr;
1930         destp = ntohs(inet->dport);
1931         srcp  = ntohs(inet->sport);
1932
1933         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1934                 timer_active    = 1;
1935                 timer_expires   = icsk->icsk_timeout;
1936         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1937                 timer_active    = 4;
1938                 timer_expires   = icsk->icsk_timeout;
1939         } else if (timer_pending(&sp->sk_timer)) {
1940                 timer_active    = 2;
1941                 timer_expires   = sp->sk_timer.expires;
1942         } else {
1943                 timer_active    = 0;
1944                 timer_expires = jiffies;
1945         }
1946
1947         seq_printf(seq,
1948                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1949                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %lu %lu %u %u %d\n",
1950                    i,
1951                    src->s6_addr32[0], src->s6_addr32[1],
1952                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1953                    dest->s6_addr32[0], dest->s6_addr32[1],
1954                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1955                    sp->sk_state,
1956                    tp->write_seq-tp->snd_una,
1957                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1958                    timer_active,
1959                    jiffies_to_clock_t(timer_expires - jiffies),
1960                    icsk->icsk_retransmits,
1961                    sock_i_uid(sp),
1962                    icsk->icsk_probes_out,
1963                    sock_i_ino(sp),
1964                    atomic_read(&sp->sk_refcnt), sp,
1965                    jiffies_to_clock_t(icsk->icsk_rto),
1966                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1967                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1968                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
1969                    );
1970 }
1971
1972 static void get_timewait6_sock(struct seq_file *seq,
1973                                struct inet_timewait_sock *tw, int i)
1974 {
1975         struct in6_addr *dest, *src;
1976         __u16 destp, srcp;
1977         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1978         int ttd = tw->tw_ttd - jiffies;
1979
1980         if (ttd < 0)
1981                 ttd = 0;
1982
1983         dest = &tw6->tw_v6_daddr;
1984         src  = &tw6->tw_v6_rcv_saddr;
1985         destp = ntohs(tw->tw_dport);
1986         srcp  = ntohs(tw->tw_sport);
1987
1988         seq_printf(seq,
1989                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1990                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1991                    i,
1992                    src->s6_addr32[0], src->s6_addr32[1],
1993                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1994                    dest->s6_addr32[0], dest->s6_addr32[1],
1995                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1996                    tw->tw_substate, 0, 0,
1997                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
1998                    atomic_read(&tw->tw_refcnt), tw);
1999 }
2000
2001 static int tcp6_seq_show(struct seq_file *seq, void *v)
2002 {
2003         struct tcp_iter_state *st;
2004
2005         if (v == SEQ_START_TOKEN) {
2006                 seq_puts(seq,
2007                          "  sl  "
2008                          "local_address                         "
2009                          "remote_address                        "
2010                          "st tx_queue rx_queue tr tm->when retrnsmt"
2011                          "   uid  timeout inode\n");
2012                 goto out;
2013         }
2014         st = seq->private;
2015
2016         switch (st->state) {
2017         case TCP_SEQ_STATE_LISTENING:
2018         case TCP_SEQ_STATE_ESTABLISHED:
2019                 get_tcp6_sock(seq, v, st->num);
2020                 break;
2021         case TCP_SEQ_STATE_OPENREQ:
2022                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2023                 break;
2024         case TCP_SEQ_STATE_TIME_WAIT:
2025                 get_timewait6_sock(seq, v, st->num);
2026                 break;
2027         }
2028 out:
2029         return 0;
2030 }
2031
2032 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2033         .name           = "tcp6",
2034         .family         = AF_INET6,
2035         .seq_fops       = {
2036                 .owner          = THIS_MODULE,
2037         },
2038         .seq_ops        = {
2039                 .show           = tcp6_seq_show,
2040         },
2041 };
2042
2043 int tcp6_proc_init(struct net *net)
2044 {
2045         return tcp_proc_register(net, &tcp6_seq_afinfo);
2046 }
2047
2048 void tcp6_proc_exit(struct net *net)
2049 {
2050         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2051 }
2052 #endif
2053
2054 struct proto tcpv6_prot = {
2055         .name                   = "TCPv6",
2056         .owner                  = THIS_MODULE,
2057         .close                  = tcp_close,
2058         .connect                = tcp_v6_connect,
2059         .disconnect             = tcp_disconnect,
2060         .accept                 = inet_csk_accept,
2061         .ioctl                  = tcp_ioctl,
2062         .init                   = tcp_v6_init_sock,
2063         .destroy                = tcp_v6_destroy_sock,
2064         .shutdown               = tcp_shutdown,
2065         .setsockopt             = tcp_setsockopt,
2066         .getsockopt             = tcp_getsockopt,
2067         .recvmsg                = tcp_recvmsg,
2068         .backlog_rcv            = tcp_v6_do_rcv,
2069         .hash                   = tcp_v6_hash,
2070         .unhash                 = inet_unhash,
2071         .get_port               = inet_csk_get_port,
2072         .enter_memory_pressure  = tcp_enter_memory_pressure,
2073         .sockets_allocated      = &tcp_sockets_allocated,
2074         .memory_allocated       = &tcp_memory_allocated,
2075         .memory_pressure        = &tcp_memory_pressure,
2076         .orphan_count           = &tcp_orphan_count,
2077         .sysctl_mem             = sysctl_tcp_mem,
2078         .sysctl_wmem            = sysctl_tcp_wmem,
2079         .sysctl_rmem            = sysctl_tcp_rmem,
2080         .max_header             = MAX_TCP_HEADER,
2081         .obj_size               = sizeof(struct tcp6_sock),
2082         .slab_flags             = SLAB_DESTROY_BY_RCU,
2083         .twsk_prot              = &tcp6_timewait_sock_ops,
2084         .rsk_prot               = &tcp6_request_sock_ops,
2085         .h.hashinfo             = &tcp_hashinfo,
2086 #ifdef CONFIG_COMPAT
2087         .compat_setsockopt      = compat_tcp_setsockopt,
2088         .compat_getsockopt      = compat_tcp_getsockopt,
2089 #endif
2090 };
2091
2092 static struct inet6_protocol tcpv6_protocol = {
2093         .handler        =       tcp_v6_rcv,
2094         .err_handler    =       tcp_v6_err,
2095         .gso_send_check =       tcp_v6_gso_send_check,
2096         .gso_segment    =       tcp_tso_segment,
2097         .gro_receive    =       tcp6_gro_receive,
2098         .gro_complete   =       tcp6_gro_complete,
2099         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2100 };
2101
2102 static struct inet_protosw tcpv6_protosw = {
2103         .type           =       SOCK_STREAM,
2104         .protocol       =       IPPROTO_TCP,
2105         .prot           =       &tcpv6_prot,
2106         .ops            =       &inet6_stream_ops,
2107         .capability     =       -1,
2108         .no_check       =       0,
2109         .flags          =       INET_PROTOSW_PERMANENT |
2110                                 INET_PROTOSW_ICSK,
2111 };
2112
2113 static int tcpv6_net_init(struct net *net)
2114 {
2115         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2116                                     SOCK_RAW, IPPROTO_TCP, net);
2117 }
2118
2119 static void tcpv6_net_exit(struct net *net)
2120 {
2121         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2122         inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET6);
2123 }
2124
2125 static struct pernet_operations tcpv6_net_ops = {
2126         .init = tcpv6_net_init,
2127         .exit = tcpv6_net_exit,
2128 };
2129
2130 int __init tcpv6_init(void)
2131 {
2132         int ret;
2133
2134         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2135         if (ret)
2136                 goto out;
2137
2138         /* register inet6 protocol */
2139         ret = inet6_register_protosw(&tcpv6_protosw);
2140         if (ret)
2141                 goto out_tcpv6_protocol;
2142
2143         ret = register_pernet_subsys(&tcpv6_net_ops);
2144         if (ret)
2145                 goto out_tcpv6_protosw;
2146 out:
2147         return ret;
2148
2149 out_tcpv6_protocol:
2150         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2151 out_tcpv6_protosw:
2152         inet6_unregister_protosw(&tcpv6_protosw);
2153         goto out;
2154 }
2155
2156 void tcpv6_exit(void)
2157 {
2158         unregister_pernet_subsys(&tcpv6_net_ops);
2159         inet6_unregister_protosw(&tcpv6_protosw);
2160         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2161 }