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/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/types.h>
  29 #include <linux/socket.h>
  30 #include <linux/sockios.h>
  31 #include <linux/net.h>
  32 #include <linux/jiffies.h>
  33 #include <linux/in.h>
  34 #include <linux/in6.h>
  35 #include <linux/netdevice.h>
  36 #include <linux/init.h>
  37 #include <linux/jhash.h>
  38 #include <linux/ipsec.h>
  39 #include <linux/times.h>
  40
  41 #include <linux/ipv6.h>
  42 #include <linux/icmpv6.h>
  43 #include <linux/random.h>
  44
  45 #include <net/tcp.h>
  46 #include <net/ndisc.h>
  47 #include <net/inet6_hashtables.h>
  48 #include <net/inet6_connection_sock.h>
  49 #include <net/ipv6.h>
  50 #include <net/transp_v6.h>
  51 #include <net/addrconf.h>
  52 #include <net/ip6_route.h>
  53 #include <net/ip6_checksum.h>
  54 #include <net/inet_ecn.h>
  55 #include <net/protocol.h>
  56 #include <net/xfrm.h>
  57 #include <net/snmp.h>
  58 #include <net/dsfield.h>
  59 #include <net/timewait_sock.h>
  60 #include <net/netdma.h>
  61 #include <net/inet_common.h>
  62
  63 #include <asm/uaccess.h>
  64
  65 #include <linux/proc_fs.h>
  66 #include <linux/seq_file.h>
  67
  68 #include <linux/crypto.h>
  69 #include <linux/scatterlist.h>
  70
  71 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  72 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  73                                       struct request_sock *req);
  74
  75 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  76
  77 static struct inet_connection_sock_af_ops ipv6_mapped;
  78 static struct inet_connection_sock_af_ops ipv6_specific;
  79 #ifdef CONFIG_TCP_MD5SIG
  80 static struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  81 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  82 #else
  83 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  84                                                    struct in6_addr *addr)
  85 {
  86         return NULL;
  87 }
  88 #endif
  89
  90 static void tcp_v6_hash(struct sock *sk)
  91 {
  92         if (sk->sk_state != TCP_CLOSE) {
  93                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
  94                         tcp_prot.hash(sk);
  95                         return;
  96                 }
  97                 local_bh_disable();
  98                 __inet6_hash(sk);
  99                 local_bh_enable();
 100         }
 101 }
 102
 103 static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len,
 104                                    struct in6_addr *saddr,
 105                                    struct in6_addr *daddr,
 106                                    __wsum base)
 107 {
 108         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
 109 }
 110
 111 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
 112 {
 113         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 114                                             ipv6_hdr(skb)->saddr.s6_addr32,
 115                                             tcp_hdr(skb)->dest,
 116                                             tcp_hdr(skb)->source);
 117 }
 118
 119 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 120                           int addr_len)
 121 {
 122         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 123         struct inet_sock *inet = inet_sk(sk);
 124         struct inet_connection_sock *icsk = inet_csk(sk);
 125         struct ipv6_pinfo *np = inet6_sk(sk);
 126         struct tcp_sock *tp = tcp_sk(sk);
 127         struct in6_addr *saddr = NULL, *final_p = NULL, final;
 128         struct flowi fl;
 129         struct dst_entry *dst;
 130         int addr_type;
 131         int err;
 132
 133         if (addr_len < SIN6_LEN_RFC2133)
 134                 return -EINVAL;
 135
 136         if (usin->sin6_family != AF_INET6)
 137                 return(-EAFNOSUPPORT);
 138
 139         memset(&fl, 0, sizeof(fl));
 140
 141         if (np->sndflow) {
 142                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 143                 IP6_ECN_flow_init(fl.fl6_flowlabel);
 144                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
 145                         struct ip6_flowlabel *flowlabel;
 146                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
 147                         if (flowlabel == NULL)
 148                                 return -EINVAL;
 149                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
 150                         fl6_sock_release(flowlabel);
 151                 }
 152         }
 153
 154         /*
 155          *      connect() to INADDR_ANY means loopback (BSD'ism).
 156          */
 157
 158         if(ipv6_addr_any(&usin->sin6_addr))
 159                 usin->sin6_addr.s6_addr[15] = 0x1;
 160
 161         addr_type = ipv6_addr_type(&usin->sin6_addr);
 162
 163         if(addr_type & IPV6_ADDR_MULTICAST)
 164                 return -ENETUNREACH;
 165
 166         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 167                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 168                     usin->sin6_scope_id) {
 169                         /* If interface is set while binding, indices
 170                          * must coincide.
 171                          */
 172                         if (sk->sk_bound_dev_if &&
 173                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 174                                 return -EINVAL;
 175
 176                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 177                 }
 178
 179                 /* Connect to link-local address requires an interface */
 180                 if (!sk->sk_bound_dev_if)
 181                         return -EINVAL;
 182         }
 183
 184         if (tp->rx_opt.ts_recent_stamp &&
 185             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 186                 tp->rx_opt.ts_recent = 0;
 187                 tp->rx_opt.ts_recent_stamp = 0;
 188                 tp->write_seq = 0;
 189         }
 190
 191         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
 192         np->flow_label = fl.fl6_flowlabel;
 193
 194         /*
 195          *      TCP over IPv4
 196          */
 197
 198         if (addr_type == IPV6_ADDR_MAPPED) {
 199                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 200                 struct sockaddr_in sin;
 201
 202                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 203
 204                 if (__ipv6_only_sock(sk))
 205                         return -ENETUNREACH;
 206
 207                 sin.sin_family = AF_INET;
 208                 sin.sin_port = usin->sin6_port;
 209                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 210
 211                 icsk->icsk_af_ops = &ipv6_mapped;
 212                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 213 #ifdef CONFIG_TCP_MD5SIG
 214                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 215 #endif
 216
 217                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 218
 219                 if (err) {
 220                         icsk->icsk_ext_hdr_len = exthdrlen;
 221                         icsk->icsk_af_ops = &ipv6_specific;
 222                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 223 #ifdef CONFIG_TCP_MD5SIG
 224                         tp->af_specific = &tcp_sock_ipv6_specific;
 225 #endif
 226                         goto failure;
 227                 } else {
 228                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
 229                                       inet->saddr);
 230                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
 231                                       inet->rcv_saddr);
 232                 }
 233
 234                 return err;
 235         }
 236
 237         if (!ipv6_addr_any(&np->rcv_saddr))
 238                 saddr = &np->rcv_saddr;
 239
 240         fl.proto = IPPROTO_TCP;
 241         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 242         ipv6_addr_copy(&fl.fl6_src,
 243                        (saddr ? saddr : &np->saddr));
 244         fl.oif = sk->sk_bound_dev_if;
 245         fl.fl_ip_dport = usin->sin6_port;
 246         fl.fl_ip_sport = inet->sport;
 247
 248         if (np->opt && np->opt->srcrt) {
 249                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 250                 ipv6_addr_copy(&final, &fl.fl6_dst);
 251                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 252                 final_p = &final;
 253         }
 254
 255         security_sk_classify_flow(sk, &fl);
 256
 257         err = ip6_dst_lookup(sk, &dst, &fl);
 258         if (err)
 259                 goto failure;
 260         if (final_p)
 261                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 262
 263         if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
 264                 if (err == -EREMOTE)
 265                         err = ip6_dst_blackhole(sk, &dst, &fl);
 266                 if (err < 0)
 267                         goto failure;
 268         }
 269
 270         if (saddr == NULL) {
 271                 saddr = &fl.fl6_src;
 272                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 273         }
 274
 275         /* set the source address */
 276         ipv6_addr_copy(&np->saddr, saddr);
 277         inet->rcv_saddr = LOOPBACK4_IPV6;
 278
 279         sk->sk_gso_type = SKB_GSO_TCPV6;
 280         __ip6_dst_store(sk, dst, NULL, NULL);
 281
 282         icsk->icsk_ext_hdr_len = 0;
 283         if (np->opt)
 284                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 285                                           np->opt->opt_nflen);
 286
 287         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 288
 289         inet->dport = usin->sin6_port;
 290
 291         tcp_set_state(sk, TCP_SYN_SENT);
 292         err = inet6_hash_connect(&tcp_death_row, sk);
 293         if (err)
 294                 goto late_failure;
 295
 296         if (!tp->write_seq)
 297                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 298                                                              np->daddr.s6_addr32,
 299                                                              inet->sport,
 300                                                              inet->dport);
 301
 302         err = tcp_connect(sk);
 303         if (err)
 304                 goto late_failure;
 305
 306         return 0;
 307
 308 late_failure:
 309         tcp_set_state(sk, TCP_CLOSE);
 310         __sk_dst_reset(sk);
 311 failure:
 312         inet->dport = 0;
 313         sk->sk_route_caps = 0;
 314         return err;
 315 }
 316
 317 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 318                 int type, int code, int offset, __be32 info)
 319 {
 320         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
 321         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 322         struct ipv6_pinfo *np;
 323         struct sock *sk;
 324         int err;
 325         struct tcp_sock *tp;
 326         __u32 seq;
 327         struct net *net = dev_net(skb->dev);
 328
 329         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
 330                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 331
 332         if (sk == NULL) {
 333                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 334                                    ICMP6_MIB_INERRORS);
 335                 return;
 336         }
 337
 338         if (sk->sk_state == TCP_TIME_WAIT) {
 339                 inet_twsk_put(inet_twsk(sk));
 340                 return;
 341         }
 342
 343         bh_lock_sock(sk);
 344         if (sock_owned_by_user(sk))
 345                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 346
 347         if (sk->sk_state == TCP_CLOSE)
 348                 goto out;
 349
 350         tp = tcp_sk(sk);
 351         seq = ntohl(th->seq);
 352         if (sk->sk_state != TCP_LISTEN &&
 353             !between(seq, tp->snd_una, tp->snd_nxt)) {
 354                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 355                 goto out;
 356         }
 357
 358         np = inet6_sk(sk);
 359
 360         if (type == ICMPV6_PKT_TOOBIG) {
 361                 struct dst_entry *dst = NULL;
 362
 363                 if (sock_owned_by_user(sk))
 364                         goto out;
 365                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 366                         goto out;
 367
 368                 /* icmp should have updated the destination cache entry */
 369                 dst = __sk_dst_check(sk, np->dst_cookie);
 370
 371                 if (dst == NULL) {
 372                         struct inet_sock *inet = inet_sk(sk);
 373                         struct flowi fl;
 374
 375                         /* BUGGG_FUTURE: Again, it is not clear how
 376                            to handle rthdr case. Ignore this complexity
 377                            for now.
 378                          */
 379                         memset(&fl, 0, sizeof(fl));
 380                         fl.proto = IPPROTO_TCP;
 381                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 382                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 383                         fl.oif = sk->sk_bound_dev_if;
 384                         fl.fl_ip_dport = inet->dport;
 385                         fl.fl_ip_sport = inet->sport;
 386                         security_skb_classify_flow(skb, &fl);
 387
 388                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
 389                                 sk->sk_err_soft = -err;
 390                                 goto out;
 391                         }
 392
 393                         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 394                                 sk->sk_err_soft = -err;
 395                                 goto out;
 396                         }
 397
 398                 } else
 399                         dst_hold(dst);
 400
 401                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 402                         tcp_sync_mss(sk, dst_mtu(dst));
 403                         tcp_simple_retransmit(sk);
 404                 } /* else let the usual retransmit timer handle it */
 405                 dst_release(dst);
 406                 goto out;
 407         }
 408
 409         icmpv6_err_convert(type, code, &err);
 410
 411         /* Might be for an request_sock */
 412         switch (sk->sk_state) {
 413                 struct request_sock *req, **prev;
 414         case TCP_LISTEN:
 415                 if (sock_owned_by_user(sk))
 416                         goto out;
 417
 418                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 419                                            &hdr->saddr, inet6_iif(skb));
 420                 if (!req)
 421                         goto out;
 422
 423                 /* ICMPs are not backlogged, hence we cannot get
 424                  * an established socket here.
 425                  */
 426                 WARN_ON(req->sk != NULL);
 427
 428                 if (seq != tcp_rsk(req)->snt_isn) {
 429                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 430                         goto out;
 431                 }
 432
 433                 inet_csk_reqsk_queue_drop(sk, req, prev);
 434                 goto out;
 435
 436         case TCP_SYN_SENT:
 437         case TCP_SYN_RECV:  /* Cannot happen.
 438                                It can, it SYNs are crossed. --ANK */
 439                 if (!sock_owned_by_user(sk)) {
 440                         sk->sk_err = err;
 441                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 442
 443                         tcp_done(sk);
 444                 } else
 445                         sk->sk_err_soft = err;
 446                 goto out;
 447         }
 448
 449         if (!sock_owned_by_user(sk) && np->recverr) {
 450                 sk->sk_err = err;
 451                 sk->sk_error_report(sk);
 452         } else
 453                 sk->sk_err_soft = err;
 454
 455 out:
 456         bh_unlock_sock(sk);
 457         sock_put(sk);
 458 }
 459
 460
 461 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
 462 {
 463         struct inet6_request_sock *treq = inet6_rsk(req);
 464         struct ipv6_pinfo *np = inet6_sk(sk);
 465         struct sk_buff * skb;
 466         struct ipv6_txoptions *opt = NULL;
 467         struct in6_addr * final_p = NULL, final;
 468         struct flowi fl;
 469         struct dst_entry *dst;
 470         int err = -1;
 471
 472         memset(&fl, 0, sizeof(fl));
 473         fl.proto = IPPROTO_TCP;
 474         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 475         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
 476         fl.fl6_flowlabel = 0;
 477         fl.oif = treq->iif;
 478         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
 479         fl.fl_ip_sport = inet_sk(sk)->sport;
 480         security_req_classify_flow(req, &fl);
 481
 482         opt = np->opt;
 483         if (opt && opt->srcrt) {
 484                 struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
 485                 ipv6_addr_copy(&final, &fl.fl6_dst);
 486                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 487                 final_p = &final;
 488         }
 489
 490         err = ip6_dst_lookup(sk, &dst, &fl);
 491         if (err)
 492                 goto done;
 493         if (final_p)
 494                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 495         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 496                 goto done;
 497
 498         skb = tcp_make_synack(sk, dst, req);
 499         if (skb) {
 500                 struct tcphdr *th = tcp_hdr(skb);
 501
 502                 th->check = tcp_v6_check(th, skb->len,
 503                                          &treq->loc_addr, &treq->rmt_addr,
 504                                          csum_partial((char *)th, skb->len, skb->csum));
 505
 506                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 507                 err = ip6_xmit(sk, skb, &fl, opt, 0);
 508                 err = net_xmit_eval(err);
 509         }
 510
 511 done:
 512         if (opt && opt != np->opt)
 513                 sock_kfree_s(sk, opt, opt->tot_len);
 514         dst_release(dst);
 515         return err;
 516 }
 517
 518 static inline void syn_flood_warning(struct sk_buff *skb)
 519 {
 520 #ifdef CONFIG_SYN_COOKIES
 521         if (sysctl_tcp_syncookies)
 522                 printk(KERN_INFO
 523                        "TCPv6: Possible SYN flooding on port %d. "
 524                        "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
 525         else
 526 #endif
 527                 printk(KERN_INFO
 528                        "TCPv6: Possible SYN flooding on port %d. "
 529                        "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
 530 }
 531
 532 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 533 {
 534         if (inet6_rsk(req)->pktopts)
 535                 kfree_skb(inet6_rsk(req)->pktopts);
 536 }
 537
 538 #ifdef CONFIG_TCP_MD5SIG
 539 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 540                                                    struct in6_addr *addr)
 541 {
 542         struct tcp_sock *tp = tcp_sk(sk);
 543         int i;
 544
 545         BUG_ON(tp == NULL);
 546
 547         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 548                 return NULL;
 549
 550         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 551                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
 552                         return &tp->md5sig_info->keys6[i].base;
 553         }
 554         return NULL;
 555 }
 556
 557 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 558                                                 struct sock *addr_sk)
 559 {
 560         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 561 }
 562
 563 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 564                                                       struct request_sock *req)
 565 {
 566         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 567 }
 568
 569 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
 570                              char *newkey, u8 newkeylen)
 571 {
 572         /* Add key to the list */
 573         struct tcp_md5sig_key *key;
 574         struct tcp_sock *tp = tcp_sk(sk);
 575         struct tcp6_md5sig_key *keys;
 576
 577         key = tcp_v6_md5_do_lookup(sk, peer);
 578         if (key) {
 579                 /* modify existing entry - just update that one */
 580                 kfree(key->key);
 581                 key->key = newkey;
 582                 key->keylen = newkeylen;
 583         } else {
 584                 /* reallocate new list if current one is full. */
 585                 if (!tp->md5sig_info) {
 586                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 587                         if (!tp->md5sig_info) {
 588                                 kfree(newkey);
 589                                 return -ENOMEM;
 590                         }
 591                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 592                 }
 593                 if (tcp_alloc_md5sig_pool() == NULL) {
 594                         kfree(newkey);
 595                         return -ENOMEM;
 596                 }
 597                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 598                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 599                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 600
 601                         if (!keys) {
 602                                 tcp_free_md5sig_pool();
 603                                 kfree(newkey);
 604                                 return -ENOMEM;
 605                         }
 606
 607                         if (tp->md5sig_info->entries6)
 608                                 memmove(keys, tp->md5sig_info->keys6,
 609                                         (sizeof (tp->md5sig_info->keys6[0]) *
 610                                          tp->md5sig_info->entries6));
 611
 612                         kfree(tp->md5sig_info->keys6);
 613                         tp->md5sig_info->keys6 = keys;
 614                         tp->md5sig_info->alloced6++;
 615                 }
 616
 617                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 618                                peer);
 619                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
 620                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
 621
 622                 tp->md5sig_info->entries6++;
 623         }
 624         return 0;
 625 }
 626
 627 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 628                                u8 *newkey, __u8 newkeylen)
 629 {
 630         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 631                                  newkey, newkeylen);
 632 }
 633
 634 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 635 {
 636         struct tcp_sock *tp = tcp_sk(sk);
 637         int i;
 638
 639         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 640                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
 641                         /* Free the key */
 642                         kfree(tp->md5sig_info->keys6[i].base.key);
 643                         tp->md5sig_info->entries6--;
 644
 645                         if (tp->md5sig_info->entries6 == 0) {
 646                                 kfree(tp->md5sig_info->keys6);
 647                                 tp->md5sig_info->keys6 = NULL;
 648                                 tp->md5sig_info->alloced6 = 0;
 649                         } else {
 650                                 /* shrink the database */
 651                                 if (tp->md5sig_info->entries6 != i)
 652                                         memmove(&tp->md5sig_info->keys6[i],
 653                                                 &tp->md5sig_info->keys6[i+1],
 654                                                 (tp->md5sig_info->entries6 - i)
 655                                                 * sizeof (tp->md5sig_info->keys6[0]));
 656                         }
 657                         tcp_free_md5sig_pool();
 658                         return 0;
 659                 }
 660         }
 661         return -ENOENT;
 662 }
 663
 664 static void tcp_v6_clear_md5_list (struct sock *sk)
 665 {
 666         struct tcp_sock *tp = tcp_sk(sk);
 667         int i;
 668
 669         if (tp->md5sig_info->entries6) {
 670                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 671                         kfree(tp->md5sig_info->keys6[i].base.key);
 672                 tp->md5sig_info->entries6 = 0;
 673                 tcp_free_md5sig_pool();
 674         }
 675
 676         kfree(tp->md5sig_info->keys6);
 677         tp->md5sig_info->keys6 = NULL;
 678         tp->md5sig_info->alloced6 = 0;
 679
 680         if (tp->md5sig_info->entries4) {
 681                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 682                         kfree(tp->md5sig_info->keys4[i].base.key);
 683                 tp->md5sig_info->entries4 = 0;
 684                 tcp_free_md5sig_pool();
 685         }
 686
 687         kfree(tp->md5sig_info->keys4);
 688         tp->md5sig_info->keys4 = NULL;
 689         tp->md5sig_info->alloced4 = 0;
 690 }
 691
 692 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 693                                   int optlen)
 694 {
 695         struct tcp_md5sig cmd;
 696         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 697         u8 *newkey;
 698
 699         if (optlen < sizeof(cmd))
 700                 return -EINVAL;
 701
 702         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 703                 return -EFAULT;
 704
 705         if (sin6->sin6_family != AF_INET6)
 706                 return -EINVAL;
 707
 708         if (!cmd.tcpm_keylen) {
 709                 if (!tcp_sk(sk)->md5sig_info)
 710                         return -ENOENT;
 711                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 712                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 713                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 714         }
 715
 716         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 717                 return -EINVAL;
 718
 719         if (!tcp_sk(sk)->md5sig_info) {
 720                 struct tcp_sock *tp = tcp_sk(sk);
 721                 struct tcp_md5sig_info *p;
 722
 723                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 724                 if (!p)
 725                         return -ENOMEM;
 726
 727                 tp->md5sig_info = p;
 728                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 729         }
 730
 731         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 732         if (!newkey)
 733                 return -ENOMEM;
 734         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 735                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 736                                          newkey, cmd.tcpm_keylen);
 737         }
 738         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 739 }
 740
 741 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 742                                         struct in6_addr *daddr,
 743                                         struct in6_addr *saddr, int nbytes)
 744 {
 745         struct tcp6_pseudohdr *bp;
 746         struct scatterlist sg;
 747
 748         bp = &hp->md5_blk.ip6;
 749         /* 1. TCP pseudo-header (RFC2460) */
 750         ipv6_addr_copy(&bp->saddr, saddr);
 751         ipv6_addr_copy(&bp->daddr, daddr);
 752         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 753         bp->len = cpu_to_be32(nbytes);
 754
 755         sg_init_one(&sg, bp, sizeof(*bp));
 756         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 757 }
 758
 759 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 760                                struct in6_addr *daddr, struct in6_addr *saddr,
 761                                struct tcphdr *th)
 762 {
 763         struct tcp_md5sig_pool *hp;
 764         struct hash_desc *desc;
 765
 766         hp = tcp_get_md5sig_pool();
 767         if (!hp)
 768                 goto clear_hash_noput;
 769         desc = &hp->md5_desc;
 770
 771         if (crypto_hash_init(desc))
 772                 goto clear_hash;
 773         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 774                 goto clear_hash;
 775         if (tcp_md5_hash_header(hp, th))
 776                 goto clear_hash;
 777         if (tcp_md5_hash_key(hp, key))
 778                 goto clear_hash;
 779         if (crypto_hash_final(desc, md5_hash))
 780                 goto clear_hash;
 781
 782         tcp_put_md5sig_pool();
 783         return 0;
 784
 785 clear_hash:
 786         tcp_put_md5sig_pool();
 787 clear_hash_noput:
 788         memset(md5_hash, 0, 16);
 789         return 1;
 790 }
 791
 792 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 793                                struct sock *sk, struct request_sock *req,
 794                                struct sk_buff *skb)
 795 {
 796         struct in6_addr *saddr, *daddr;
 797         struct tcp_md5sig_pool *hp;
 798         struct hash_desc *desc;
 799         struct tcphdr *th = tcp_hdr(skb);
 800
 801         if (sk) {
 802                 saddr = &inet6_sk(sk)->saddr;
 803                 daddr = &inet6_sk(sk)->daddr;
 804         } else if (req) {
 805                 saddr = &inet6_rsk(req)->loc_addr;
 806                 daddr = &inet6_rsk(req)->rmt_addr;
 807         } else {
 808                 struct ipv6hdr *ip6h = ipv6_hdr(skb);
 809                 saddr = &ip6h->saddr;
 810                 daddr = &ip6h->daddr;
 811         }
 812
 813         hp = tcp_get_md5sig_pool();
 814         if (!hp)
 815                 goto clear_hash_noput;
 816         desc = &hp->md5_desc;
 817
 818         if (crypto_hash_init(desc))
 819                 goto clear_hash;
 820
 821         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 822                 goto clear_hash;
 823         if (tcp_md5_hash_header(hp, th))
 824                 goto clear_hash;
 825         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 826                 goto clear_hash;
 827         if (tcp_md5_hash_key(hp, key))
 828                 goto clear_hash;
 829         if (crypto_hash_final(desc, md5_hash))
 830                 goto clear_hash;
 831
 832         tcp_put_md5sig_pool();
 833         return 0;
 834
 835 clear_hash:
 836         tcp_put_md5sig_pool();
 837 clear_hash_noput:
 838         memset(md5_hash, 0, 16);
 839         return 1;
 840 }
 841
 842 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 843 {
 844         __u8 *hash_location = NULL;
 845         struct tcp_md5sig_key *hash_expected;
 846         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 847         struct tcphdr *th = tcp_hdr(skb);
 848         int genhash;
 849         u8 newhash[16];
 850
 851         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 852         hash_location = tcp_parse_md5sig_option(th);
 853
 854         /* We've parsed the options - do we have a hash? */
 855         if (!hash_expected && !hash_location)
 856                 return 0;
 857
 858         if (hash_expected && !hash_location) {
 859                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 860                 return 1;
 861         }
 862
 863         if (!hash_expected && hash_location) {
 864                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 865                 return 1;
 866         }
 867
 868         /* check the signature */
 869         genhash = tcp_v6_md5_hash_skb(newhash,
 870                                       hash_expected,
 871                                       NULL, NULL, skb);
 872
 873         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 874                 if (net_ratelimit()) {
 875                         printk(KERN_INFO "MD5 Hash %s for "
 876                                "(" NIP6_FMT ", %u)->"
 877                                "(" NIP6_FMT ", %u)\n",
 878                                genhash ? "failed" : "mismatch",
 879                                NIP6(ip6h->saddr), ntohs(th->source),
 880                                NIP6(ip6h->daddr), ntohs(th->dest));
 881                 }
 882                 return 1;
 883         }
 884         return 0;
 885 }
 886 #endif
 887
 888 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 889         .family         =       AF_INET6,
 890         .obj_size       =       sizeof(struct tcp6_request_sock),
 891         .rtx_syn_ack    =       tcp_v6_send_synack,
 892         .send_ack       =       tcp_v6_reqsk_send_ack,
 893         .destructor     =       tcp_v6_reqsk_destructor,
 894         .send_reset     =       tcp_v6_send_reset
 895 };
 896
 897 #ifdef CONFIG_TCP_MD5SIG
 898 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 899         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 900 };
 901 #endif
 902
 903 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 904         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 905         .twsk_unique    = tcp_twsk_unique,
 906         .twsk_destructor= tcp_twsk_destructor,
 907 };
 908
 909 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 910 {
 911         struct ipv6_pinfo *np = inet6_sk(sk);
 912         struct tcphdr *th = tcp_hdr(skb);
 913
 914         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 915                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 916                 skb->csum_start = skb_transport_header(skb) - skb->head;
 917                 skb->csum_offset = offsetof(struct tcphdr, check);
 918         } else {
 919                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 920                                             csum_partial((char *)th, th->doff<<2,
 921                                                          skb->csum));
 922         }
 923 }
 924
 925 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 926 {
 927         struct ipv6hdr *ipv6h;
 928         struct tcphdr *th;
 929
 930         if (!pskb_may_pull(skb, sizeof(*th)))
 931                 return -EINVAL;
 932
 933         ipv6h = ipv6_hdr(skb);
 934         th = tcp_hdr(skb);
 935
 936         th->check = 0;
 937         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 938                                      IPPROTO_TCP, 0);
 939         skb->csum_start = skb_transport_header(skb) - skb->head;
 940         skb->csum_offset = offsetof(struct tcphdr, check);
 941         skb->ip_summed = CHECKSUM_PARTIAL;
 942         return 0;
 943 }
 944
 945 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 946 {
 947         struct tcphdr *th = tcp_hdr(skb), *t1;
 948         struct sk_buff *buff;
 949         struct flowi fl;
 950         struct net *net = dev_net(skb->dst->dev);
 951         struct sock *ctl_sk = net->ipv6.tcp_sk;
 952         unsigned int tot_len = sizeof(*th);
 953 #ifdef CONFIG_TCP_MD5SIG
 954         struct tcp_md5sig_key *key;
 955 #endif
 956
 957         if (th->rst)
 958                 return;
 959
 960         if (!ipv6_unicast_destination(skb))
 961                 return;
 962
 963 #ifdef CONFIG_TCP_MD5SIG
 964         if (sk)
 965                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
 966         else
 967                 key = NULL;
 968
 969         if (key)
 970                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 971 #endif
 972
 973         /*
 974          * We need to grab some memory, and put together an RST,
 975          * and then put it into the queue to be sent.
 976          */
 977
 978         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
 979                          GFP_ATOMIC);
 980         if (buff == NULL)
 981                 return;
 982
 983         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
 984
 985         t1 = (struct tcphdr *) skb_push(buff, tot_len);
 986
 987         /* Swap the send and the receive. */
 988         memset(t1, 0, sizeof(*t1));
 989         t1->dest = th->source;
 990         t1->source = th->dest;
 991         t1->doff = tot_len / 4;
 992         t1->rst = 1;
 993
 994         if(th->ack) {
 995                 t1->seq = th->ack_seq;
 996         } else {
 997                 t1->ack = 1;
 998                 t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
 999                                     + skb->len - (th->doff<<2));
1000         }
1001
1002 #ifdef CONFIG_TCP_MD5SIG
1003         if (key) {
1004                 __be32 *opt = (__be32*)(t1 + 1);
1005                 opt[0] = htonl((TCPOPT_NOP << 24) |
1006                                (TCPOPT_NOP << 16) |
1007                                (TCPOPT_MD5SIG << 8) |
1008                                TCPOLEN_MD5SIG);
1009                 tcp_v6_md5_hash_hdr((__u8 *)&opt[1], key,
1010                                     &ipv6_hdr(skb)->saddr,
1011                                     &ipv6_hdr(skb)->daddr, t1);
1012         }
1013 #endif
1014
1015         buff->csum = csum_partial((char *)t1, tot_len, 0);
1016
1017         memset(&fl, 0, sizeof(fl));
1018         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1019         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1020
1021         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1022                                     tot_len, IPPROTO_TCP,
1023                                     buff->csum);
1024
1025         fl.proto = IPPROTO_TCP;
1026         fl.oif = inet6_iif(skb);
1027         fl.fl_ip_dport = t1->dest;
1028         fl.fl_ip_sport = t1->source;
1029         security_skb_classify_flow(skb, &fl);
1030
1031         /* Pass a socket to ip6_dst_lookup either it is for RST
1032          * Underlying function will use this to retrieve the network
1033          * namespace
1034          */
1035         if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
1036
1037                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1038                         ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1039                         TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1040                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1041                         return;
1042                 }
1043         }
1044
1045         kfree_skb(buff);
1046 }
1047
1048 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1049                             struct tcp_md5sig_key *key)
1050 {
1051         struct tcphdr *th = tcp_hdr(skb), *t1;
1052         struct sk_buff *buff;
1053         struct flowi fl;
1054         struct net *net = dev_net(skb->dst->dev);
1055         struct sock *ctl_sk = net->ipv6.tcp_sk;
1056         unsigned int tot_len = sizeof(struct tcphdr);
1057         __be32 *topt;
1058
1059         if (ts)
1060                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1061 #ifdef CONFIG_TCP_MD5SIG
1062         if (key)
1063                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1064 #endif
1065
1066         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1067                          GFP_ATOMIC);
1068         if (buff == NULL)
1069                 return;
1070
1071         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1072
1073         t1 = (struct tcphdr *) skb_push(buff,tot_len);
1074
1075         /* Swap the send and the receive. */
1076         memset(t1, 0, sizeof(*t1));
1077         t1->dest = th->source;
1078         t1->source = th->dest;
1079         t1->doff = tot_len/4;
1080         t1->seq = htonl(seq);
1081         t1->ack_seq = htonl(ack);
1082         t1->ack = 1;
1083         t1->window = htons(win);
1084
1085         topt = (__be32 *)(t1 + 1);
1086
1087         if (ts) {
1088                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1089                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1090                 *topt++ = htonl(tcp_time_stamp);
1091                 *topt++ = htonl(ts);
1092         }
1093
1094 #ifdef CONFIG_TCP_MD5SIG
1095         if (key) {
1096                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1097                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1098                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1099                                     &ipv6_hdr(skb)->saddr,
1100                                     &ipv6_hdr(skb)->daddr, t1);
1101         }
1102 #endif
1103
1104         buff->csum = csum_partial((char *)t1, tot_len, 0);
1105
1106         memset(&fl, 0, sizeof(fl));
1107         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1108         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1109
1110         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1111                                     tot_len, IPPROTO_TCP,
1112                                     buff->csum);
1113
1114         fl.proto = IPPROTO_TCP;
1115         fl.oif = inet6_iif(skb);
1116         fl.fl_ip_dport = t1->dest;
1117         fl.fl_ip_sport = t1->source;
1118         security_skb_classify_flow(skb, &fl);
1119
1120         if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
1121                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1122                         ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
1123                         TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1124                         return;
1125                 }
1126         }
1127
1128         kfree_skb(buff);
1129 }
1130
1131 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1132 {
1133         struct inet_timewait_sock *tw = inet_twsk(sk);
1134         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1135
1136         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1137                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1138                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1139
1140         inet_twsk_put(tw);
1141 }
1142
1143 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1144                                   struct request_sock *req)
1145 {
1146         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1147                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1148 }
1149
1150
1151 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1152 {
1153         struct request_sock *req, **prev;
1154         const struct tcphdr *th = tcp_hdr(skb);
1155         struct sock *nsk;
1156
1157         /* Find possible connection requests. */
1158         req = inet6_csk_search_req(sk, &prev, th->source,
1159                                    &ipv6_hdr(skb)->saddr,
1160                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1161         if (req)
1162                 return tcp_check_req(sk, skb, req, prev);
1163
1164         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1165                         &ipv6_hdr(skb)->saddr, th->source,
1166                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1167
1168         if (nsk) {
1169                 if (nsk->sk_state != TCP_TIME_WAIT) {
1170                         bh_lock_sock(nsk);
1171                         return nsk;
1172                 }
1173                 inet_twsk_put(inet_twsk(nsk));
1174                 return NULL;
1175         }
1176
1177 #ifdef CONFIG_SYN_COOKIES
1178         if (!th->rst && !th->syn && th->ack)
1179                 sk = cookie_v6_check(sk, skb);
1180 #endif
1181         return sk;
1182 }
1183
1184 /* FIXME: this is substantially similar to the ipv4 code.
1185  * Can some kind of merge be done? -- erics
1186  */
1187 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1188 {
1189         struct inet6_request_sock *treq;
1190         struct ipv6_pinfo *np = inet6_sk(sk);
1191         struct tcp_options_received tmp_opt;
1192         struct tcp_sock *tp = tcp_sk(sk);
1193         struct request_sock *req = NULL;
1194         __u32 isn = TCP_SKB_CB(skb)->when;
1195 #ifdef CONFIG_SYN_COOKIES
1196         int want_cookie = 0;
1197 #else
1198 #define want_cookie 0
1199 #endif
1200
1201         if (skb->protocol == htons(ETH_P_IP))
1202                 return tcp_v4_conn_request(sk, skb);
1203
1204         if (!ipv6_unicast_destination(skb))
1205                 goto drop;
1206
1207         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1208                 if (net_ratelimit())
1209                         syn_flood_warning(skb);
1210 #ifdef CONFIG_SYN_COOKIES
1211                 if (sysctl_tcp_syncookies)
1212                         want_cookie = 1;
1213                 else
1214 #endif
1215                 goto drop;
1216         }
1217
1218         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1219                 goto drop;
1220
1221         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1222         if (req == NULL)
1223                 goto drop;
1224
1225 #ifdef CONFIG_TCP_MD5SIG
1226         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1227 #endif
1228
1229         tcp_clear_options(&tmp_opt);
1230         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1231         tmp_opt.user_mss = tp->rx_opt.user_mss;
1232
1233         tcp_parse_options(skb, &tmp_opt, 0);
1234
1235         if (want_cookie && !tmp_opt.saw_tstamp)
1236                 tcp_clear_options(&tmp_opt);
1237
1238         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1239         tcp_openreq_init(req, &tmp_opt, skb);
1240
1241         treq = inet6_rsk(req);
1242         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1243         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1244         if (!want_cookie)
1245                 TCP_ECN_create_request(req, tcp_hdr(skb));
1246
1247         if (want_cookie) {
1248                 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1249                 req->cookie_ts = tmp_opt.tstamp_ok;
1250         } else if (!isn) {
1251                 if (ipv6_opt_accepted(sk, skb) ||
1252                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1253                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1254                         atomic_inc(&skb->users);
1255                         treq->pktopts = skb;
1256                 }
1257                 treq->iif = sk->sk_bound_dev_if;
1258
1259                 /* So that link locals have meaning */
1260                 if (!sk->sk_bound_dev_if &&
1261                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1262                         treq->iif = inet6_iif(skb);
1263
1264                 isn = tcp_v6_init_sequence(skb);
1265         }
1266
1267         tcp_rsk(req)->snt_isn = isn;
1268
1269         security_inet_conn_request(sk, skb, req);
1270
1271         if (tcp_v6_send_synack(sk, req))
1272                 goto drop;
1273
1274         if (!want_cookie) {
1275                 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1276                 return 0;
1277         }
1278
1279 drop:
1280         if (req)
1281                 reqsk_free(req);
1282
1283         return 0; /* don't send reset */
1284 }
1285
1286 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1287                                           struct request_sock *req,
1288                                           struct dst_entry *dst)
1289 {
1290         struct inet6_request_sock *treq;
1291         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1292         struct tcp6_sock *newtcp6sk;
1293         struct inet_sock *newinet;
1294         struct tcp_sock *newtp;
1295         struct sock *newsk;
1296         struct ipv6_txoptions *opt;
1297 #ifdef CONFIG_TCP_MD5SIG
1298         struct tcp_md5sig_key *key;
1299 #endif
1300
1301         if (skb->protocol == htons(ETH_P_IP)) {
1302                 /*
1303                  *      v6 mapped
1304                  */
1305
1306                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1307
1308                 if (newsk == NULL)
1309                         return NULL;
1310
1311                 newtcp6sk = (struct tcp6_sock *)newsk;
1312                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1313
1314                 newinet = inet_sk(newsk);
1315                 newnp = inet6_sk(newsk);
1316                 newtp = tcp_sk(newsk);
1317
1318                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1319
1320                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1321                               newinet->daddr);
1322
1323                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1324                               newinet->saddr);
1325
1326                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1327
1328                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1329                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1330 #ifdef CONFIG_TCP_MD5SIG
1331                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1332 #endif
1333
1334                 newnp->pktoptions  = NULL;
1335                 newnp->opt         = NULL;
1336                 newnp->mcast_oif   = inet6_iif(skb);
1337                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1338
1339                 /*
1340                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1341                  * here, tcp_create_openreq_child now does this for us, see the comment in
1342                  * that function for the gory details. -acme
1343                  */
1344
1345                 /* It is tricky place. Until this moment IPv4 tcp
1346                    worked with IPv6 icsk.icsk_af_ops.
1347                    Sync it now.
1348                  */
1349                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1350
1351                 return newsk;
1352         }
1353
1354         treq = inet6_rsk(req);
1355         opt = np->opt;
1356
1357         if (sk_acceptq_is_full(sk))
1358                 goto out_overflow;
1359
1360         if (dst == NULL) {
1361                 struct in6_addr *final_p = NULL, final;
1362                 struct flowi fl;
1363
1364                 memset(&fl, 0, sizeof(fl));
1365                 fl.proto = IPPROTO_TCP;
1366                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1367                 if (opt && opt->srcrt) {
1368                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1369                         ipv6_addr_copy(&final, &fl.fl6_dst);
1370                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1371                         final_p = &final;
1372                 }
1373                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1374                 fl.oif = sk->sk_bound_dev_if;
1375                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1376                 fl.fl_ip_sport = inet_sk(sk)->sport;
1377                 security_req_classify_flow(req, &fl);
1378
1379                 if (ip6_dst_lookup(sk, &dst, &fl))
1380                         goto out;
1381
1382                 if (final_p)
1383                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1384
1385                 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
1386                         goto out;
1387         }
1388
1389         newsk = tcp_create_openreq_child(sk, req, skb);
1390         if (newsk == NULL)
1391                 goto out;
1392
1393         /*
1394          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1395          * count here, tcp_create_openreq_child now does this for us, see the
1396          * comment in that function for the gory details. -acme
1397          */
1398
1399         newsk->sk_gso_type = SKB_GSO_TCPV6;
1400         __ip6_dst_store(newsk, dst, NULL, NULL);
1401
1402         newtcp6sk = (struct tcp6_sock *)newsk;
1403         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1404
1405         newtp = tcp_sk(newsk);
1406         newinet = inet_sk(newsk);
1407         newnp = inet6_sk(newsk);
1408
1409         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1410
1411         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1412         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1413         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1414         newsk->sk_bound_dev_if = treq->iif;
1415
1416         /* Now IPv6 options...
1417
1418            First: no IPv4 options.
1419          */
1420         newinet->opt = NULL;
1421         newnp->ipv6_fl_list = NULL;
1422
1423         /* Clone RX bits */
1424         newnp->rxopt.all = np->rxopt.all;
1425
1426         /* Clone pktoptions received with SYN */
1427         newnp->pktoptions = NULL;
1428         if (treq->pktopts != NULL) {
1429                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1430                 kfree_skb(treq->pktopts);
1431                 treq->pktopts = NULL;
1432                 if (newnp->pktoptions)
1433                         skb_set_owner_r(newnp->pktoptions, newsk);
1434         }
1435         newnp->opt        = NULL;
1436         newnp->mcast_oif  = inet6_iif(skb);
1437         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1438
1439         /* Clone native IPv6 options from listening socket (if any)
1440
1441            Yes, keeping reference count would be much more clever,
1442            but we make one more one thing there: reattach optmem
1443            to newsk.
1444          */
1445         if (opt) {
1446                 newnp->opt = ipv6_dup_options(newsk, opt);
1447                 if (opt != np->opt)
1448                         sock_kfree_s(sk, opt, opt->tot_len);
1449         }
1450
1451         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1452         if (newnp->opt)
1453                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1454                                                      newnp->opt->opt_flen);
1455
1456         tcp_mtup_init(newsk);
1457         tcp_sync_mss(newsk, dst_mtu(dst));
1458         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1459         tcp_initialize_rcv_mss(newsk);
1460
1461         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1462
1463 #ifdef CONFIG_TCP_MD5SIG
1464         /* Copy over the MD5 key from the original socket */
1465         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1466                 /* We're using one, so create a matching key
1467                  * on the newsk structure. If we fail to get
1468                  * memory, then we end up not copying the key
1469                  * across. Shucks.
1470                  */
1471                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1472                 if (newkey != NULL)
1473                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1474                                           newkey, key->keylen);
1475         }
1476 #endif
1477
1478         __inet6_hash(newsk);
1479         __inet_inherit_port(sk, newsk);
1480
1481         return newsk;
1482
1483 out_overflow:
1484         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1485 out:
1486         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1487         if (opt && opt != np->opt)
1488                 sock_kfree_s(sk, opt, opt->tot_len);
1489         dst_release(dst);
1490         return NULL;
1491 }
1492
1493 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1494 {
1495         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1496                 if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1497                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1498                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1499                         return 0;
1500                 }
1501         }
1502
1503         skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1504                                               &ipv6_hdr(skb)->saddr,
1505                                               &ipv6_hdr(skb)->daddr, 0));
1506
1507         if (skb->len <= 76) {
1508                 return __skb_checksum_complete(skb);
1509         }
1510         return 0;
1511 }
1512
1513 /* The socket must have it's spinlock held when we get
1514  * here.
1515  *
1516  * We have a potential double-lock case here, so even when
1517  * doing backlog processing we use the BH locking scheme.
1518  * This is because we cannot sleep with the original spinlock
1519  * held.
1520  */
1521 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1522 {
1523         struct ipv6_pinfo *np = inet6_sk(sk);
1524         struct tcp_sock *tp;
1525         struct sk_buff *opt_skb = NULL;
1526
1527         /* Imagine: socket is IPv6. IPv4 packet arrives,
1528            goes to IPv4 receive handler and backlogged.
1529            From backlog it always goes here. Kerboom...
1530            Fortunately, tcp_rcv_established and rcv_established
1531            handle them correctly, but it is not case with
1532            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1533          */
1534
1535         if (skb->protocol == htons(ETH_P_IP))
1536                 return tcp_v4_do_rcv(sk, skb);
1537
1538 #ifdef CONFIG_TCP_MD5SIG
1539         if (tcp_v6_inbound_md5_hash (sk, skb))
1540                 goto discard;
1541 #endif
1542
1543         if (sk_filter(sk, skb))
1544                 goto discard;
1545
1546         /*
1547          *      socket locking is here for SMP purposes as backlog rcv
1548          *      is currently called with bh processing disabled.
1549          */
1550
1551         /* Do Stevens' IPV6_PKTOPTIONS.
1552
1553            Yes, guys, it is the only place in our code, where we
1554            may make it not affecting IPv4.
1555            The rest of code is protocol independent,
1556            and I do not like idea to uglify IPv4.
1557
1558            Actually, all the idea behind IPV6_PKTOPTIONS
1559            looks not very well thought. For now we latch
1560            options, received in the last packet, enqueued
1561            by tcp. Feel free to propose better solution.
1562                                                --ANK (980728)
1563          */
1564         if (np->rxopt.all)
1565                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1566
1567         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1568                 TCP_CHECK_TIMER(sk);
1569                 if (tcp_rcv_established(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
1577         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1578                 goto csum_err;
1579
1580         if (sk->sk_state == TCP_LISTEN) {
1581                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1582                 if (!nsk)
1583                         goto discard;
1584
1585                 /*
1586                  * Queue it on the new socket if the new socket is active,
1587                  * otherwise we just shortcircuit this and continue with
1588                  * the new socket..
1589                  */
1590                 if(nsk != sk) {
1591                         if (tcp_child_process(sk, nsk, skb))
1592                                 goto reset;
1593                         if (opt_skb)
1594                                 __kfree_skb(opt_skb);
1595                         return 0;
1596                 }
1597         }
1598
1599         TCP_CHECK_TIMER(sk);
1600         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1601                 goto reset;
1602         TCP_CHECK_TIMER(sk);
1603         if (opt_skb)
1604                 goto ipv6_pktoptions;
1605         return 0;
1606
1607 reset:
1608         tcp_v6_send_reset(sk, skb);
1609 discard:
1610         if (opt_skb)
1611                 __kfree_skb(opt_skb);
1612         kfree_skb(skb);
1613         return 0;
1614 csum_err:
1615         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1616         goto discard;
1617
1618
1619 ipv6_pktoptions:
1620         /* Do you ask, what is it?
1621
1622            1. skb was enqueued by tcp.
1623            2. skb is added to tail of read queue, rather than out of order.
1624            3. socket is not in passive state.
1625            4. Finally, it really contains options, which user wants to receive.
1626          */
1627         tp = tcp_sk(sk);
1628         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1629             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1630                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1631                         np->mcast_oif = inet6_iif(opt_skb);
1632                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1633                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1634                 if (ipv6_opt_accepted(sk, opt_skb)) {
1635                         skb_set_owner_r(opt_skb, sk);
1636                         opt_skb = xchg(&np->pktoptions, opt_skb);
1637                 } else {
1638                         __kfree_skb(opt_skb);
1639                         opt_skb = xchg(&np->pktoptions, NULL);
1640                 }
1641         }
1642
1643         if (opt_skb)
1644                 kfree_skb(opt_skb);
1645         return 0;
1646 }
1647
1648 static int tcp_v6_rcv(struct sk_buff *skb)
1649 {
1650         struct tcphdr *th;
1651         struct sock *sk;
1652         int ret;
1653         struct net *net = dev_net(skb->dev);
1654
1655         if (skb->pkt_type != PACKET_HOST)
1656                 goto discard_it;
1657
1658         /*
1659          *      Count it even if it's bad.
1660          */
1661         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1662
1663         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1664                 goto discard_it;
1665
1666         th = tcp_hdr(skb);
1667
1668         if (th->doff < sizeof(struct tcphdr)/4)
1669                 goto bad_packet;
1670         if (!pskb_may_pull(skb, th->doff*4))
1671                 goto discard_it;
1672
1673         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1674                 goto bad_packet;
1675
1676         th = tcp_hdr(skb);
1677         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1678         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1679                                     skb->len - th->doff*4);
1680         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1681         TCP_SKB_CB(skb)->when = 0;
1682         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1683         TCP_SKB_CB(skb)->sacked = 0;
1684
1685         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1686         if (!sk)
1687                 goto no_tcp_socket;
1688
1689 process:
1690         if (sk->sk_state == TCP_TIME_WAIT)
1691                 goto do_time_wait;
1692
1693         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1694                 goto discard_and_relse;
1695
1696         if (sk_filter(sk, skb))
1697                 goto discard_and_relse;
1698
1699         skb->dev = NULL;
1700
1701         bh_lock_sock_nested(sk);
1702         ret = 0;
1703         if (!sock_owned_by_user(sk)) {
1704 #ifdef CONFIG_NET_DMA
1705                 struct tcp_sock *tp = tcp_sk(sk);
1706                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1707                         tp->ucopy.dma_chan = get_softnet_dma();
1708                 if (tp->ucopy.dma_chan)
1709                         ret = tcp_v6_do_rcv(sk, skb);
1710                 else
1711 #endif
1712                 {
1713                         if (!tcp_prequeue(sk, skb))
1714                                 ret = tcp_v6_do_rcv(sk, skb);
1715                 }
1716         } else
1717                 sk_add_backlog(sk, skb);
1718         bh_unlock_sock(sk);
1719
1720         sock_put(sk);
1721         return ret ? -1 : 0;
1722
1723 no_tcp_socket:
1724         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1725                 goto discard_it;
1726
1727         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1728 bad_packet:
1729                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1730         } else {
1731                 tcp_v6_send_reset(NULL, skb);
1732         }
1733
1734 discard_it:
1735
1736         /*
1737          *      Discard frame
1738          */
1739
1740         kfree_skb(skb);
1741         return 0;
1742
1743 discard_and_relse:
1744         sock_put(sk);
1745         goto discard_it;
1746
1747 do_time_wait:
1748         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1749                 inet_twsk_put(inet_twsk(sk));
1750                 goto discard_it;
1751         }
1752
1753         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1754                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1755                 inet_twsk_put(inet_twsk(sk));
1756                 goto discard_it;
1757         }
1758
1759         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1760         case TCP_TW_SYN:
1761         {
1762                 struct sock *sk2;
1763
1764                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1765                                             &ipv6_hdr(skb)->daddr,
1766                                             ntohs(th->dest), inet6_iif(skb));
1767                 if (sk2 != NULL) {
1768                         struct inet_timewait_sock *tw = inet_twsk(sk);
1769                         inet_twsk_deschedule(tw, &tcp_death_row);
1770                         inet_twsk_put(tw);
1771                         sk = sk2;
1772                         goto process;
1773                 }
1774                 /* Fall through to ACK */
1775         }
1776         case TCP_TW_ACK:
1777                 tcp_v6_timewait_ack(sk, skb);
1778                 break;
1779         case TCP_TW_RST:
1780                 goto no_tcp_socket;
1781         case TCP_TW_SUCCESS:;
1782         }
1783         goto discard_it;
1784 }
1785
1786 static int tcp_v6_remember_stamp(struct sock *sk)
1787 {
1788         /* Alas, not yet... */
1789         return 0;
1790 }
1791
1792 static struct inet_connection_sock_af_ops ipv6_specific = {
1793         .queue_xmit        = inet6_csk_xmit,
1794         .send_check        = tcp_v6_send_check,
1795         .rebuild_header    = inet6_sk_rebuild_header,
1796         .conn_request      = tcp_v6_conn_request,
1797         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1798         .remember_stamp    = tcp_v6_remember_stamp,
1799         .net_header_len    = sizeof(struct ipv6hdr),
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_specific = {
1813         .md5_lookup     =       tcp_v6_md5_lookup,
1814         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1815         .md5_add        =       tcp_v6_md5_add_func,
1816         .md5_parse      =       tcp_v6_parse_md5_keys,
1817 };
1818 #endif
1819
1820 /*
1821  *      TCP over IPv4 via INET6 API
1822  */
1823
1824 static struct inet_connection_sock_af_ops ipv6_mapped = {
1825         .queue_xmit        = ip_queue_xmit,
1826         .send_check        = tcp_v4_send_check,
1827         .rebuild_header    = inet_sk_rebuild_header,
1828         .conn_request      = tcp_v6_conn_request,
1829         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1830         .remember_stamp    = tcp_v4_remember_stamp,
1831         .net_header_len    = sizeof(struct iphdr),
1832         .setsockopt        = ipv6_setsockopt,
1833         .getsockopt        = ipv6_getsockopt,
1834         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1835         .sockaddr_len      = sizeof(struct sockaddr_in6),
1836         .bind_conflict     = inet6_csk_bind_conflict,
1837 #ifdef CONFIG_COMPAT
1838         .compat_setsockopt = compat_ipv6_setsockopt,
1839         .compat_getsockopt = compat_ipv6_getsockopt,
1840 #endif
1841 };
1842
1843 #ifdef CONFIG_TCP_MD5SIG
1844 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1845         .md5_lookup     =       tcp_v4_md5_lookup,
1846         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1847         .md5_add        =       tcp_v6_md5_add_func,
1848         .md5_parse      =       tcp_v6_parse_md5_keys,
1849 };
1850 #endif
1851
1852 /* NOTE: A lot of things set to zero explicitly by call to
1853  *       sk_alloc() so need not be done here.
1854  */
1855 static int tcp_v6_init_sock(struct sock *sk)
1856 {
1857         struct inet_connection_sock *icsk = inet_csk(sk);
1858         struct tcp_sock *tp = tcp_sk(sk);
1859
1860         skb_queue_head_init(&tp->out_of_order_queue);
1861         tcp_init_xmit_timers(sk);
1862         tcp_prequeue_init(tp);
1863
1864         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1865         tp->mdev = TCP_TIMEOUT_INIT;
1866
1867         /* So many TCP implementations out there (incorrectly) count the
1868          * initial SYN frame in their delayed-ACK and congestion control
1869          * algorithms that we must have the following bandaid to talk
1870          * efficiently to them.  -DaveM
1871          */
1872         tp->snd_cwnd = 2;
1873
1874         /* See draft-stevens-tcpca-spec-01 for discussion of the
1875          * initialization of these values.
1876          */
1877         tp->snd_ssthresh = 0x7fffffff;
1878         tp->snd_cwnd_clamp = ~0;
1879         tp->mss_cache = 536;
1880
1881         tp->reordering = sysctl_tcp_reordering;
1882
1883         sk->sk_state = TCP_CLOSE;
1884
1885         icsk->icsk_af_ops = &ipv6_specific;
1886         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1887         icsk->icsk_sync_mss = tcp_sync_mss;
1888         sk->sk_write_space = sk_stream_write_space;
1889         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1890
1891 #ifdef CONFIG_TCP_MD5SIG
1892         tp->af_specific = &tcp_sock_ipv6_specific;
1893 #endif
1894
1895         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1896         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1897
1898         atomic_inc(&tcp_sockets_allocated);
1899
1900         return 0;
1901 }
1902
1903 static void tcp_v6_destroy_sock(struct sock *sk)
1904 {
1905 #ifdef CONFIG_TCP_MD5SIG
1906         /* Clean up the MD5 key list */
1907         if (tcp_sk(sk)->md5sig_info)
1908                 tcp_v6_clear_md5_list(sk);
1909 #endif
1910         tcp_v4_destroy_sock(sk);
1911         inet6_destroy_sock(sk);
1912 }
1913
1914 #ifdef CONFIG_PROC_FS
1915 /* Proc filesystem TCPv6 sock list dumping. */
1916 static void get_openreq6(struct seq_file *seq,
1917                          struct sock *sk, struct request_sock *req, int i, int uid)
1918 {
1919         int ttd = req->expires - jiffies;
1920         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1921         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1922
1923         if (ttd < 0)
1924                 ttd = 0;
1925
1926         seq_printf(seq,
1927                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1928                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1929                    i,
1930                    src->s6_addr32[0], src->s6_addr32[1],
1931                    src->s6_addr32[2], src->s6_addr32[3],
1932                    ntohs(inet_sk(sk)->sport),
1933                    dest->s6_addr32[0], dest->s6_addr32[1],
1934                    dest->s6_addr32[2], dest->s6_addr32[3],
1935                    ntohs(inet_rsk(req)->rmt_port),
1936                    TCP_SYN_RECV,
1937                    0,0, /* could print option size, but that is af dependent. */
1938                    1,   /* timers active (only the expire timer) */
1939                    jiffies_to_clock_t(ttd),
1940                    req->retrans,
1941                    uid,
1942                    0,  /* non standard timer */
1943                    0, /* open_requests have no inode */
1944                    0, req);
1945 }
1946
1947 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1948 {
1949         struct in6_addr *dest, *src;
1950         __u16 destp, srcp;
1951         int timer_active;
1952         unsigned long timer_expires;
1953         struct inet_sock *inet = inet_sk(sp);
1954         struct tcp_sock *tp = tcp_sk(sp);
1955         const struct inet_connection_sock *icsk = inet_csk(sp);
1956         struct ipv6_pinfo *np = inet6_sk(sp);
1957
1958         dest  = &np->daddr;
1959         src   = &np->rcv_saddr;
1960         destp = ntohs(inet->dport);
1961         srcp  = ntohs(inet->sport);
1962
1963         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1964                 timer_active    = 1;
1965                 timer_expires   = icsk->icsk_timeout;
1966         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1967                 timer_active    = 4;
1968                 timer_expires   = icsk->icsk_timeout;
1969         } else if (timer_pending(&sp->sk_timer)) {
1970                 timer_active    = 2;
1971                 timer_expires   = sp->sk_timer.expires;
1972         } else {
1973                 timer_active    = 0;
1974                 timer_expires = jiffies;
1975         }
1976
1977         seq_printf(seq,
1978                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1979                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %lu %lu %u %u %d\n",
1980                    i,
1981                    src->s6_addr32[0], src->s6_addr32[1],
1982                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1983                    dest->s6_addr32[0], dest->s6_addr32[1],
1984                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1985                    sp->sk_state,
1986                    tp->write_seq-tp->snd_una,
1987                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1988                    timer_active,
1989                    jiffies_to_clock_t(timer_expires - jiffies),
1990                    icsk->icsk_retransmits,
1991                    sock_i_uid(sp),
1992                    icsk->icsk_probes_out,
1993                    sock_i_ino(sp),
1994                    atomic_read(&sp->sk_refcnt), sp,
1995                    jiffies_to_clock_t(icsk->icsk_rto),
1996                    jiffies_to_clock_t(icsk->icsk_ack.ato),
1997                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1998                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
1999                    );
2000 }
2001
2002 static void get_timewait6_sock(struct seq_file *seq,
2003                                struct inet_timewait_sock *tw, int i)
2004 {
2005         struct in6_addr *dest, *src;
2006         __u16 destp, srcp;
2007         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2008         int ttd = tw->tw_ttd - jiffies;
2009
2010         if (ttd < 0)
2011                 ttd = 0;
2012
2013         dest = &tw6->tw_v6_daddr;
2014         src  = &tw6->tw_v6_rcv_saddr;
2015         destp = ntohs(tw->tw_dport);
2016         srcp  = ntohs(tw->tw_sport);
2017
2018         seq_printf(seq,
2019                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2020                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2021                    i,
2022                    src->s6_addr32[0], src->s6_addr32[1],
2023                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2024                    dest->s6_addr32[0], dest->s6_addr32[1],
2025                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2026                    tw->tw_substate, 0, 0,
2027                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2028                    atomic_read(&tw->tw_refcnt), tw);
2029 }
2030
2031 static int tcp6_seq_show(struct seq_file *seq, void *v)
2032 {
2033         struct tcp_iter_state *st;
2034
2035         if (v == SEQ_START_TOKEN) {
2036                 seq_puts(seq,
2037                          "  sl  "
2038                          "local_address                         "
2039                          "remote_address                        "
2040                          "st tx_queue rx_queue tr tm->when retrnsmt"
2041                          "   uid  timeout inode\n");
2042                 goto out;
2043         }
2044         st = seq->private;
2045
2046         switch (st->state) {
2047         case TCP_SEQ_STATE_LISTENING:
2048         case TCP_SEQ_STATE_ESTABLISHED:
2049                 get_tcp6_sock(seq, v, st->num);
2050                 break;
2051         case TCP_SEQ_STATE_OPENREQ:
2052                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2053                 break;
2054         case TCP_SEQ_STATE_TIME_WAIT:
2055                 get_timewait6_sock(seq, v, st->num);
2056                 break;
2057         }
2058 out:
2059         return 0;
2060 }
2061
2062 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2063         .name           = "tcp6",
2064         .family         = AF_INET6,
2065         .seq_fops       = {
2066                 .owner          = THIS_MODULE,
2067         },
2068         .seq_ops        = {
2069                 .show           = tcp6_seq_show,
2070         },
2071 };
2072
2073 int tcp6_proc_init(struct net *net)
2074 {
2075         return tcp_proc_register(net, &tcp6_seq_afinfo);
2076 }
2077
2078 void tcp6_proc_exit(struct net *net)
2079 {
2080         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2081 }
2082 #endif
2083
2084 struct proto tcpv6_prot = {
2085         .name                   = "TCPv6",
2086         .owner                  = THIS_MODULE,
2087         .close                  = tcp_close,
2088         .connect                = tcp_v6_connect,
2089         .disconnect             = tcp_disconnect,
2090         .accept                 = inet_csk_accept,
2091         .ioctl                  = tcp_ioctl,
2092         .init                   = tcp_v6_init_sock,
2093         .destroy                = tcp_v6_destroy_sock,
2094         .shutdown               = tcp_shutdown,
2095         .setsockopt             = tcp_setsockopt,
2096         .getsockopt             = tcp_getsockopt,
2097         .recvmsg                = tcp_recvmsg,
2098         .backlog_rcv            = tcp_v6_do_rcv,
2099         .hash                   = tcp_v6_hash,
2100         .unhash                 = inet_unhash,
2101         .get_port               = inet_csk_get_port,
2102         .enter_memory_pressure  = tcp_enter_memory_pressure,
2103         .sockets_allocated      = &tcp_sockets_allocated,
2104         .memory_allocated       = &tcp_memory_allocated,
2105         .memory_pressure        = &tcp_memory_pressure,
2106         .orphan_count           = &tcp_orphan_count,
2107         .sysctl_mem             = sysctl_tcp_mem,
2108         .sysctl_wmem            = sysctl_tcp_wmem,
2109         .sysctl_rmem            = sysctl_tcp_rmem,
2110         .max_header             = MAX_TCP_HEADER,
2111         .obj_size               = sizeof(struct tcp6_sock),
2112         .twsk_prot              = &tcp6_timewait_sock_ops,
2113         .rsk_prot               = &tcp6_request_sock_ops,
2114         .h.hashinfo             = &tcp_hashinfo,
2115 #ifdef CONFIG_COMPAT
2116         .compat_setsockopt      = compat_tcp_setsockopt,
2117         .compat_getsockopt      = compat_tcp_getsockopt,
2118 #endif
2119 };
2120
2121 static struct inet6_protocol tcpv6_protocol = {
2122         .handler        =       tcp_v6_rcv,
2123         .err_handler    =       tcp_v6_err,
2124         .gso_send_check =       tcp_v6_gso_send_check,
2125         .gso_segment    =       tcp_tso_segment,
2126         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2127 };
2128
2129 static struct inet_protosw tcpv6_protosw = {
2130         .type           =       SOCK_STREAM,
2131         .protocol       =       IPPROTO_TCP,
2132         .prot           =       &tcpv6_prot,
2133         .ops            =       &inet6_stream_ops,
2134         .capability     =       -1,
2135         .no_check       =       0,
2136         .flags          =       INET_PROTOSW_PERMANENT |
2137                                 INET_PROTOSW_ICSK,
2138 };
2139
2140 static int tcpv6_net_init(struct net *net)
2141 {
2142         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2143                                     SOCK_RAW, IPPROTO_TCP, net);
2144 }
2145
2146 static void tcpv6_net_exit(struct net *net)
2147 {
2148         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2149         inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET6);
2150 }
2151
2152 static struct pernet_operations tcpv6_net_ops = {
2153         .init = tcpv6_net_init,
2154         .exit = tcpv6_net_exit,
2155 };
2156
2157 int __init tcpv6_init(void)
2158 {
2159         int ret;
2160
2161         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2162         if (ret)
2163                 goto out;
2164
2165         /* register inet6 protocol */
2166         ret = inet6_register_protosw(&tcpv6_protosw);
2167         if (ret)
2168                 goto out_tcpv6_protocol;
2169
2170         ret = register_pernet_subsys(&tcpv6_net_ops);
2171         if (ret)
2172                 goto out_tcpv6_protosw;
2173 out:
2174         return ret;
2175
2176 out_tcpv6_protocol:
2177         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2178 out_tcpv6_protosw:
2179         inet6_unregister_protosw(&tcpv6_protosw);
2180         goto out;
2181 }
2182
2183 void tcpv6_exit(void)
2184 {
2185         unregister_pernet_subsys(&tcpv6_net_ops);
2186         inet6_unregister_protosw(&tcpv6_protosw);
2187         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2188 }