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   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      $Id: tcp_ipv6.c,v 1.144 2002/02/01 22:01:04 davem Exp $
   9  *
  10  *      Based on:
  11  *      linux/net/ipv4/tcp.c
  12  *      linux/net/ipv4/tcp_input.c
  13  *      linux/net/ipv4/tcp_output.c
  14  *
  15  *      Fixes:
  16  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  17  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  18  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  19  *                                      a single port at the same time.
  20  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  21  *
  22  *      This program is free software; you can redistribute it and/or
  23  *      modify it under the terms of the GNU General Public License
  24  *      as published by the Free Software Foundation; either version
  25  *      2 of the License, or (at your option) any later version.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/types.h>
  31 #include <linux/socket.h>
  32 #include <linux/sockios.h>
  33 #include <linux/net.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/in.h>
  36 #include <linux/in6.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/init.h>
  39 #include <linux/jhash.h>
  40 #include <linux/ipsec.h>
  41 #include <linux/times.h>
  42
  43 #include <linux/ipv6.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/random.h>
  46
  47 #include <net/tcp.h>
  48 #include <net/ndisc.h>
  49 #include <net/inet6_hashtables.h>
  50 #include <net/inet6_connection_sock.h>
  51 #include <net/ipv6.h>
  52 #include <net/transp_v6.h>
  53 #include <net/addrconf.h>
  54 #include <net/ip6_route.h>
  55 #include <net/ip6_checksum.h>
  56 #include <net/inet_ecn.h>
  57 #include <net/protocol.h>
  58 #include <net/xfrm.h>
  59 #include <net/snmp.h>
  60 #include <net/dsfield.h>
  61 #include <net/timewait_sock.h>
  62 #include <net/netdma.h>
  63
  64 #include <asm/uaccess.h>
  65
  66 #include <linux/proc_fs.h>
  67 #include <linux/seq_file.h>
  68
  69 #include <linux/crypto.h>
  70 #include <linux/scatterlist.h>
  71
  72 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  73 static void     tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req);
  74 static void     tcp_v6_send_check(struct sock *sk, int len,
  75                                   struct sk_buff *skb);
  76
  77 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  78
  79 static struct inet_connection_sock_af_ops ipv6_mapped;
  80 static struct inet_connection_sock_af_ops ipv6_specific;
  81 #ifdef CONFIG_TCP_MD5SIG
  82 static struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  83 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  84 #endif
  85
  86 static void tcp_v6_hash(struct sock *sk)
  87 {
  88         if (sk->sk_state != TCP_CLOSE) {
  89                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
  90                         tcp_prot.hash(sk);
  91                         return;
  92                 }
  93                 local_bh_disable();
  94                 __inet6_hash(sk);
  95                 local_bh_enable();
  96         }
  97 }
  98
  99 static __inline__ __sum16 tcp_v6_check(struct tcphdr *th, int len,
 100                                    struct in6_addr *saddr,
 101                                    struct in6_addr *daddr,
 102                                    __wsum base)
 103 {
 104         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
 105 }
 106
 107 static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
 108 {
 109         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 110                                             ipv6_hdr(skb)->saddr.s6_addr32,
 111                                             tcp_hdr(skb)->dest,
 112                                             tcp_hdr(skb)->source);
 113 }
 114
 115 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 116                           int addr_len)
 117 {
 118         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 119         struct inet_sock *inet = inet_sk(sk);
 120         struct inet_connection_sock *icsk = inet_csk(sk);
 121         struct ipv6_pinfo *np = inet6_sk(sk);
 122         struct tcp_sock *tp = tcp_sk(sk);
 123         struct in6_addr *saddr = NULL, *final_p = NULL, final;
 124         struct flowi fl;
 125         struct dst_entry *dst;
 126         int addr_type;
 127         int err;
 128
 129         if (addr_len < SIN6_LEN_RFC2133)
 130                 return -EINVAL;
 131
 132         if (usin->sin6_family != AF_INET6)
 133                 return(-EAFNOSUPPORT);
 134
 135         memset(&fl, 0, sizeof(fl));
 136
 137         if (np->sndflow) {
 138                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 139                 IP6_ECN_flow_init(fl.fl6_flowlabel);
 140                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
 141                         struct ip6_flowlabel *flowlabel;
 142                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
 143                         if (flowlabel == NULL)
 144                                 return -EINVAL;
 145                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
 146                         fl6_sock_release(flowlabel);
 147                 }
 148         }
 149
 150         /*
 151          *      connect() to INADDR_ANY means loopback (BSD'ism).
 152          */
 153
 154         if(ipv6_addr_any(&usin->sin6_addr))
 155                 usin->sin6_addr.s6_addr[15] = 0x1;
 156
 157         addr_type = ipv6_addr_type(&usin->sin6_addr);
 158
 159         if(addr_type & IPV6_ADDR_MULTICAST)
 160                 return -ENETUNREACH;
 161
 162         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 163                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 164                     usin->sin6_scope_id) {
 165                         /* If interface is set while binding, indices
 166                          * must coincide.
 167                          */
 168                         if (sk->sk_bound_dev_if &&
 169                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 170                                 return -EINVAL;
 171
 172                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 173                 }
 174
 175                 /* Connect to link-local address requires an interface */
 176                 if (!sk->sk_bound_dev_if)
 177                         return -EINVAL;
 178         }
 179
 180         if (tp->rx_opt.ts_recent_stamp &&
 181             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 182                 tp->rx_opt.ts_recent = 0;
 183                 tp->rx_opt.ts_recent_stamp = 0;
 184                 tp->write_seq = 0;
 185         }
 186
 187         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
 188         np->flow_label = fl.fl6_flowlabel;
 189
 190         /*
 191          *      TCP over IPv4
 192          */
 193
 194         if (addr_type == IPV6_ADDR_MAPPED) {
 195                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 196                 struct sockaddr_in sin;
 197
 198                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 199
 200                 if (__ipv6_only_sock(sk))
 201                         return -ENETUNREACH;
 202
 203                 sin.sin_family = AF_INET;
 204                 sin.sin_port = usin->sin6_port;
 205                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 206
 207                 icsk->icsk_af_ops = &ipv6_mapped;
 208                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 209 #ifdef CONFIG_TCP_MD5SIG
 210                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 211 #endif
 212
 213                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 214
 215                 if (err) {
 216                         icsk->icsk_ext_hdr_len = exthdrlen;
 217                         icsk->icsk_af_ops = &ipv6_specific;
 218                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 219 #ifdef CONFIG_TCP_MD5SIG
 220                         tp->af_specific = &tcp_sock_ipv6_specific;
 221 #endif
 222                         goto failure;
 223                 } else {
 224                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
 225                                       inet->saddr);
 226                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
 227                                       inet->rcv_saddr);
 228                 }
 229
 230                 return err;
 231         }
 232
 233         if (!ipv6_addr_any(&np->rcv_saddr))
 234                 saddr = &np->rcv_saddr;
 235
 236         fl.proto = IPPROTO_TCP;
 237         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 238         ipv6_addr_copy(&fl.fl6_src,
 239                        (saddr ? saddr : &np->saddr));
 240         fl.oif = sk->sk_bound_dev_if;
 241         fl.fl_ip_dport = usin->sin6_port;
 242         fl.fl_ip_sport = inet->sport;
 243
 244         if (np->opt && np->opt->srcrt) {
 245                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 246                 ipv6_addr_copy(&final, &fl.fl6_dst);
 247                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 248                 final_p = &final;
 249         }
 250
 251         security_sk_classify_flow(sk, &fl);
 252
 253         err = ip6_dst_lookup(sk, &dst, &fl);
 254         if (err)
 255                 goto failure;
 256         if (final_p)
 257                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 258
 259         if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
 260                 if (err == -EREMOTE)
 261                         err = ip6_dst_blackhole(sk, &dst, &fl);
 262                 if (err < 0)
 263                         goto failure;
 264         }
 265
 266         if (saddr == NULL) {
 267                 saddr = &fl.fl6_src;
 268                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 269         }
 270
 271         /* set the source address */
 272         ipv6_addr_copy(&np->saddr, saddr);
 273         inet->rcv_saddr = LOOPBACK4_IPV6;
 274
 275         sk->sk_gso_type = SKB_GSO_TCPV6;
 276         __ip6_dst_store(sk, dst, NULL, NULL);
 277
 278         icsk->icsk_ext_hdr_len = 0;
 279         if (np->opt)
 280                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 281                                           np->opt->opt_nflen);
 282
 283         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 284
 285         inet->dport = usin->sin6_port;
 286
 287         tcp_set_state(sk, TCP_SYN_SENT);
 288         err = inet6_hash_connect(&tcp_death_row, sk);
 289         if (err)
 290                 goto late_failure;
 291
 292         if (!tp->write_seq)
 293                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 294                                                              np->daddr.s6_addr32,
 295                                                              inet->sport,
 296                                                              inet->dport);
 297
 298         err = tcp_connect(sk);
 299         if (err)
 300                 goto late_failure;
 301
 302         return 0;
 303
 304 late_failure:
 305         tcp_set_state(sk, TCP_CLOSE);
 306         __sk_dst_reset(sk);
 307 failure:
 308         inet->dport = 0;
 309         sk->sk_route_caps = 0;
 310         return err;
 311 }
 312
 313 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 314                 int type, int code, int offset, __be32 info)
 315 {
 316         struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
 317         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 318         struct ipv6_pinfo *np;
 319         struct sock *sk;
 320         int err;
 321         struct tcp_sock *tp;
 322         __u32 seq;
 323
 324         sk = inet6_lookup(skb->dev->nd_net, &tcp_hashinfo, &hdr->daddr,
 325                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 326
 327         if (sk == NULL) {
 328                 ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 329                 return;
 330         }
 331
 332         if (sk->sk_state == TCP_TIME_WAIT) {
 333                 inet_twsk_put(inet_twsk(sk));
 334                 return;
 335         }
 336
 337         bh_lock_sock(sk);
 338         if (sock_owned_by_user(sk))
 339                 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
 340
 341         if (sk->sk_state == TCP_CLOSE)
 342                 goto out;
 343
 344         tp = tcp_sk(sk);
 345         seq = ntohl(th->seq);
 346         if (sk->sk_state != TCP_LISTEN &&
 347             !between(seq, tp->snd_una, tp->snd_nxt)) {
 348                 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 349                 goto out;
 350         }
 351
 352         np = inet6_sk(sk);
 353
 354         if (type == ICMPV6_PKT_TOOBIG) {
 355                 struct dst_entry *dst = NULL;
 356
 357                 if (sock_owned_by_user(sk))
 358                         goto out;
 359                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 360                         goto out;
 361
 362                 /* icmp should have updated the destination cache entry */
 363                 dst = __sk_dst_check(sk, np->dst_cookie);
 364
 365                 if (dst == NULL) {
 366                         struct inet_sock *inet = inet_sk(sk);
 367                         struct flowi fl;
 368
 369                         /* BUGGG_FUTURE: Again, it is not clear how
 370                            to handle rthdr case. Ignore this complexity
 371                            for now.
 372                          */
 373                         memset(&fl, 0, sizeof(fl));
 374                         fl.proto = IPPROTO_TCP;
 375                         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 376                         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 377                         fl.oif = sk->sk_bound_dev_if;
 378                         fl.fl_ip_dport = inet->dport;
 379                         fl.fl_ip_sport = inet->sport;
 380                         security_skb_classify_flow(skb, &fl);
 381
 382                         if ((err = ip6_dst_lookup(sk, &dst, &fl))) {
 383                                 sk->sk_err_soft = -err;
 384                                 goto out;
 385                         }
 386
 387                         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 388                                 sk->sk_err_soft = -err;
 389                                 goto out;
 390                         }
 391
 392                 } else
 393                         dst_hold(dst);
 394
 395                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 396                         tcp_sync_mss(sk, dst_mtu(dst));
 397                         tcp_simple_retransmit(sk);
 398                 } /* else let the usual retransmit timer handle it */
 399                 dst_release(dst);
 400                 goto out;
 401         }
 402
 403         icmpv6_err_convert(type, code, &err);
 404
 405         /* Might be for an request_sock */
 406         switch (sk->sk_state) {
 407                 struct request_sock *req, **prev;
 408         case TCP_LISTEN:
 409                 if (sock_owned_by_user(sk))
 410                         goto out;
 411
 412                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 413                                            &hdr->saddr, inet6_iif(skb));
 414                 if (!req)
 415                         goto out;
 416
 417                 /* ICMPs are not backlogged, hence we cannot get
 418                  * an established socket here.
 419                  */
 420                 BUG_TRAP(req->sk == NULL);
 421
 422                 if (seq != tcp_rsk(req)->snt_isn) {
 423                         NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 424                         goto out;
 425                 }
 426
 427                 inet_csk_reqsk_queue_drop(sk, req, prev);
 428                 goto out;
 429
 430         case TCP_SYN_SENT:
 431         case TCP_SYN_RECV:  /* Cannot happen.
 432                                It can, it SYNs are crossed. --ANK */
 433                 if (!sock_owned_by_user(sk)) {
 434                         sk->sk_err = err;
 435                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 436
 437                         tcp_done(sk);
 438                 } else
 439                         sk->sk_err_soft = err;
 440                 goto out;
 441         }
 442
 443         if (!sock_owned_by_user(sk) && np->recverr) {
 444                 sk->sk_err = err;
 445                 sk->sk_error_report(sk);
 446         } else
 447                 sk->sk_err_soft = err;
 448
 449 out:
 450         bh_unlock_sock(sk);
 451         sock_put(sk);
 452 }
 453
 454
 455 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
 456 {
 457         struct inet6_request_sock *treq = inet6_rsk(req);
 458         struct ipv6_pinfo *np = inet6_sk(sk);
 459         struct sk_buff * skb;
 460         struct ipv6_txoptions *opt = NULL;
 461         struct in6_addr * final_p = NULL, final;
 462         struct flowi fl;
 463         struct dst_entry *dst;
 464         int err = -1;
 465
 466         memset(&fl, 0, sizeof(fl));
 467         fl.proto = IPPROTO_TCP;
 468         ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 469         ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
 470         fl.fl6_flowlabel = 0;
 471         fl.oif = treq->iif;
 472         fl.fl_ip_dport = inet_rsk(req)->rmt_port;
 473         fl.fl_ip_sport = inet_sk(sk)->sport;
 474         security_req_classify_flow(req, &fl);
 475
 476         opt = np->opt;
 477         if (opt && opt->srcrt) {
 478                 struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
 479                 ipv6_addr_copy(&final, &fl.fl6_dst);
 480                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 481                 final_p = &final;
 482         }
 483
 484         err = ip6_dst_lookup(sk, &dst, &fl);
 485         if (err)
 486                 goto done;
 487         if (final_p)
 488                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 489         if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
 490                 goto done;
 491
 492         skb = tcp_make_synack(sk, dst, req);
 493         if (skb) {
 494                 struct tcphdr *th = tcp_hdr(skb);
 495
 496                 th->check = tcp_v6_check(th, skb->len,
 497                                          &treq->loc_addr, &treq->rmt_addr,
 498                                          csum_partial((char *)th, skb->len, skb->csum));
 499
 500                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
 501                 err = ip6_xmit(sk, skb, &fl, opt, 0);
 502                 err = net_xmit_eval(err);
 503         }
 504
 505 done:
 506         if (opt && opt != np->opt)
 507                 sock_kfree_s(sk, opt, opt->tot_len);
 508         dst_release(dst);
 509         return err;
 510 }
 511
 512 static inline void syn_flood_warning(struct sk_buff *skb)
 513 {
 514 #ifdef CONFIG_SYN_COOKIES
 515         if (sysctl_tcp_syncookies)
 516                 printk(KERN_INFO
 517                        "TCPv6: Possible SYN flooding on port %d. "
 518                        "Sending cookies.\n", ntohs(tcp_hdr(skb)->dest));
 519         else
 520 #endif
 521                 printk(KERN_INFO
 522                        "TCPv6: Possible SYN flooding on port %d. "
 523                        "Dropping request.\n", ntohs(tcp_hdr(skb)->dest));
 524 }
 525
 526 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 527 {
 528         if (inet6_rsk(req)->pktopts)
 529                 kfree_skb(inet6_rsk(req)->pktopts);
 530 }
 531
 532 #ifdef CONFIG_TCP_MD5SIG
 533 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 534                                                    struct in6_addr *addr)
 535 {
 536         struct tcp_sock *tp = tcp_sk(sk);
 537         int i;
 538
 539         BUG_ON(tp == NULL);
 540
 541         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 542                 return NULL;
 543
 544         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 545                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, addr) == 0)
 546                         return &tp->md5sig_info->keys6[i].base;
 547         }
 548         return NULL;
 549 }
 550
 551 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 552                                                 struct sock *addr_sk)
 553 {
 554         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 555 }
 556
 557 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 558                                                       struct request_sock *req)
 559 {
 560         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 561 }
 562
 563 static int tcp_v6_md5_do_add(struct sock *sk, struct in6_addr *peer,
 564                              char *newkey, u8 newkeylen)
 565 {
 566         /* Add key to the list */
 567         struct tcp_md5sig_key *key;
 568         struct tcp_sock *tp = tcp_sk(sk);
 569         struct tcp6_md5sig_key *keys;
 570
 571         key = tcp_v6_md5_do_lookup(sk, peer);
 572         if (key) {
 573                 /* modify existing entry - just update that one */
 574                 kfree(key->key);
 575                 key->key = newkey;
 576                 key->keylen = newkeylen;
 577         } else {
 578                 /* reallocate new list if current one is full. */
 579                 if (!tp->md5sig_info) {
 580                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 581                         if (!tp->md5sig_info) {
 582                                 kfree(newkey);
 583                                 return -ENOMEM;
 584                         }
 585                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 586                 }
 587                 if (tcp_alloc_md5sig_pool() == NULL) {
 588                         kfree(newkey);
 589                         return -ENOMEM;
 590                 }
 591                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 592                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 593                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 594
 595                         if (!keys) {
 596                                 tcp_free_md5sig_pool();
 597                                 kfree(newkey);
 598                                 return -ENOMEM;
 599                         }
 600
 601                         if (tp->md5sig_info->entries6)
 602                                 memmove(keys, tp->md5sig_info->keys6,
 603                                         (sizeof (tp->md5sig_info->keys6[0]) *
 604                                          tp->md5sig_info->entries6));
 605
 606                         kfree(tp->md5sig_info->keys6);
 607                         tp->md5sig_info->keys6 = keys;
 608                         tp->md5sig_info->alloced6++;
 609                 }
 610
 611                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 612                                peer);
 613                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
 614                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
 615
 616                 tp->md5sig_info->entries6++;
 617         }
 618         return 0;
 619 }
 620
 621 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 622                                u8 *newkey, __u8 newkeylen)
 623 {
 624         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 625                                  newkey, newkeylen);
 626 }
 627
 628 static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
 629 {
 630         struct tcp_sock *tp = tcp_sk(sk);
 631         int i;
 632
 633         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 634                 if (ipv6_addr_cmp(&tp->md5sig_info->keys6[i].addr, peer) == 0) {
 635                         /* Free the key */
 636                         kfree(tp->md5sig_info->keys6[i].base.key);
 637                         tp->md5sig_info->entries6--;
 638
 639                         if (tp->md5sig_info->entries6 == 0) {
 640                                 kfree(tp->md5sig_info->keys6);
 641                                 tp->md5sig_info->keys6 = NULL;
 642                                 tp->md5sig_info->alloced6 = 0;
 643                         } else {
 644                                 /* shrink the database */
 645                                 if (tp->md5sig_info->entries6 != i)
 646                                         memmove(&tp->md5sig_info->keys6[i],
 647                                                 &tp->md5sig_info->keys6[i+1],
 648                                                 (tp->md5sig_info->entries6 - i)
 649                                                 * sizeof (tp->md5sig_info->keys6[0]));
 650                         }
 651                         tcp_free_md5sig_pool();
 652                         return 0;
 653                 }
 654         }
 655         return -ENOENT;
 656 }
 657
 658 static void tcp_v6_clear_md5_list (struct sock *sk)
 659 {
 660         struct tcp_sock *tp = tcp_sk(sk);
 661         int i;
 662
 663         if (tp->md5sig_info->entries6) {
 664                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 665                         kfree(tp->md5sig_info->keys6[i].base.key);
 666                 tp->md5sig_info->entries6 = 0;
 667                 tcp_free_md5sig_pool();
 668         }
 669
 670         kfree(tp->md5sig_info->keys6);
 671         tp->md5sig_info->keys6 = NULL;
 672         tp->md5sig_info->alloced6 = 0;
 673
 674         if (tp->md5sig_info->entries4) {
 675                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 676                         kfree(tp->md5sig_info->keys4[i].base.key);
 677                 tp->md5sig_info->entries4 = 0;
 678                 tcp_free_md5sig_pool();
 679         }
 680
 681         kfree(tp->md5sig_info->keys4);
 682         tp->md5sig_info->keys4 = NULL;
 683         tp->md5sig_info->alloced4 = 0;
 684 }
 685
 686 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 687                                   int optlen)
 688 {
 689         struct tcp_md5sig cmd;
 690         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 691         u8 *newkey;
 692
 693         if (optlen < sizeof(cmd))
 694                 return -EINVAL;
 695
 696         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 697                 return -EFAULT;
 698
 699         if (sin6->sin6_family != AF_INET6)
 700                 return -EINVAL;
 701
 702         if (!cmd.tcpm_keylen) {
 703                 if (!tcp_sk(sk)->md5sig_info)
 704                         return -ENOENT;
 705                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 706                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 707                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 708         }
 709
 710         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 711                 return -EINVAL;
 712
 713         if (!tcp_sk(sk)->md5sig_info) {
 714                 struct tcp_sock *tp = tcp_sk(sk);
 715                 struct tcp_md5sig_info *p;
 716
 717                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 718                 if (!p)
 719                         return -ENOMEM;
 720
 721                 tp->md5sig_info = p;
 722                 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 723         }
 724
 725         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 726         if (!newkey)
 727                 return -ENOMEM;
 728         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 729                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 730                                          newkey, cmd.tcpm_keylen);
 731         }
 732         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 733 }
 734
 735 static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 736                                    struct in6_addr *saddr,
 737                                    struct in6_addr *daddr,
 738                                    struct tcphdr *th, int protocol,
 739                                    unsigned int tcplen)
 740 {
 741         struct scatterlist sg[4];
 742         __u16 data_len;
 743         int block = 0;
 744         __sum16 cksum;
 745         struct tcp_md5sig_pool *hp;
 746         struct tcp6_pseudohdr *bp;
 747         struct hash_desc *desc;
 748         int err;
 749         unsigned int nbytes = 0;
 750
 751         hp = tcp_get_md5sig_pool();
 752         if (!hp) {
 753                 printk(KERN_WARNING "%s(): hash pool not found...\n", __func__);
 754                 goto clear_hash_noput;
 755         }
 756         bp = &hp->md5_blk.ip6;
 757         desc = &hp->md5_desc;
 758
 759         /* 1. TCP pseudo-header (RFC2460) */
 760         ipv6_addr_copy(&bp->saddr, saddr);
 761         ipv6_addr_copy(&bp->daddr, daddr);
 762         bp->len = htonl(tcplen);
 763         bp->protocol = htonl(protocol);
 764
 765         sg_init_table(sg, 4);
 766
 767         sg_set_buf(&sg[block++], bp, sizeof(*bp));
 768         nbytes += sizeof(*bp);
 769
 770         /* 2. TCP header, excluding options */
 771         cksum = th->check;
 772         th->check = 0;
 773         sg_set_buf(&sg[block++], th, sizeof(*th));
 774         nbytes += sizeof(*th);
 775
 776         /* 3. TCP segment data (if any) */
 777         data_len = tcplen - (th->doff << 2);
 778         if (data_len > 0) {
 779                 u8 *data = (u8 *)th + (th->doff << 2);
 780                 sg_set_buf(&sg[block++], data, data_len);
 781                 nbytes += data_len;
 782         }
 783
 784         /* 4. shared key */
 785         sg_set_buf(&sg[block++], key->key, key->keylen);
 786         nbytes += key->keylen;
 787
 788         sg_mark_end(&sg[block - 1]);
 789
 790         /* Now store the hash into the packet */
 791         err = crypto_hash_init(desc);
 792         if (err) {
 793                 printk(KERN_WARNING "%s(): hash_init failed\n", __func__);
 794                 goto clear_hash;
 795         }
 796         err = crypto_hash_update(desc, sg, nbytes);
 797         if (err) {
 798                 printk(KERN_WARNING "%s(): hash_update failed\n", __func__);
 799                 goto clear_hash;
 800         }
 801         err = crypto_hash_final(desc, md5_hash);
 802         if (err) {
 803                 printk(KERN_WARNING "%s(): hash_final failed\n", __func__);
 804                 goto clear_hash;
 805         }
 806
 807         /* Reset header, and free up the crypto */
 808         tcp_put_md5sig_pool();
 809         th->check = cksum;
 810 out:
 811         return 0;
 812 clear_hash:
 813         tcp_put_md5sig_pool();
 814 clear_hash_noput:
 815         memset(md5_hash, 0, 16);
 816         goto out;
 817 }
 818
 819 static int tcp_v6_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 820                                 struct sock *sk,
 821                                 struct dst_entry *dst,
 822                                 struct request_sock *req,
 823                                 struct tcphdr *th, int protocol,
 824                                 unsigned int tcplen)
 825 {
 826         struct in6_addr *saddr, *daddr;
 827
 828         if (sk) {
 829                 saddr = &inet6_sk(sk)->saddr;
 830                 daddr = &inet6_sk(sk)->daddr;
 831         } else {
 832                 saddr = &inet6_rsk(req)->loc_addr;
 833                 daddr = &inet6_rsk(req)->rmt_addr;
 834         }
 835         return tcp_v6_do_calc_md5_hash(md5_hash, key,
 836                                        saddr, daddr,
 837                                        th, protocol, tcplen);
 838 }
 839
 840 static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 841 {
 842         __u8 *hash_location = NULL;
 843         struct tcp_md5sig_key *hash_expected;
 844         struct ipv6hdr *ip6h = ipv6_hdr(skb);
 845         struct tcphdr *th = tcp_hdr(skb);
 846         int length = (th->doff << 2) - sizeof (*th);
 847         int genhash;
 848         u8 *ptr;
 849         u8 newhash[16];
 850
 851         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 852
 853         /* If the TCP option is too short, we can short cut */
 854         if (length < TCPOLEN_MD5SIG)
 855                 return hash_expected ? 1 : 0;
 856
 857         /* parse options */
 858         ptr = (u8*)(th + 1);
 859         while (length > 0) {
 860                 int opcode = *ptr++;
 861                 int opsize;
 862
 863                 switch(opcode) {
 864                 case TCPOPT_EOL:
 865                         goto done_opts;
 866                 case TCPOPT_NOP:
 867                         length--;
 868                         continue;
 869                 default:
 870                         opsize = *ptr++;
 871                         if (opsize < 2 || opsize > length)
 872                                 goto done_opts;
 873                         if (opcode == TCPOPT_MD5SIG) {
 874                                 hash_location = ptr;
 875                                 goto done_opts;
 876                         }
 877                 }
 878                 ptr += opsize - 2;
 879                 length -= opsize;
 880         }
 881
 882 done_opts:
 883         /* do we have a hash as expected? */
 884         if (!hash_expected) {
 885                 if (!hash_location)
 886                         return 0;
 887                 if (net_ratelimit()) {
 888                         printk(KERN_INFO "MD5 Hash NOT expected but found "
 889                                "(" NIP6_FMT ", %u)->"
 890                                "(" NIP6_FMT ", %u)\n",
 891                                NIP6(ip6h->saddr), ntohs(th->source),
 892                                NIP6(ip6h->daddr), ntohs(th->dest));
 893                 }
 894                 return 1;
 895         }
 896
 897         if (!hash_location) {
 898                 if (net_ratelimit()) {
 899                         printk(KERN_INFO "MD5 Hash expected but NOT found "
 900                                "(" NIP6_FMT ", %u)->"
 901                                "(" NIP6_FMT ", %u)\n",
 902                                NIP6(ip6h->saddr), ntohs(th->source),
 903                                NIP6(ip6h->daddr), ntohs(th->dest));
 904                 }
 905                 return 1;
 906         }
 907
 908         /* check the signature */
 909         genhash = tcp_v6_do_calc_md5_hash(newhash,
 910                                           hash_expected,
 911                                           &ip6h->saddr, &ip6h->daddr,
 912                                           th, sk->sk_protocol,
 913                                           skb->len);
 914         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 915                 if (net_ratelimit()) {
 916                         printk(KERN_INFO "MD5 Hash %s for "
 917                                "(" NIP6_FMT ", %u)->"
 918                                "(" NIP6_FMT ", %u)\n",
 919                                genhash ? "failed" : "mismatch",
 920                                NIP6(ip6h->saddr), ntohs(th->source),
 921                                NIP6(ip6h->daddr), ntohs(th->dest));
 922                 }
 923                 return 1;
 924         }
 925         return 0;
 926 }
 927 #endif
 928
 929 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 930         .family         =       AF_INET6,
 931         .obj_size       =       sizeof(struct tcp6_request_sock),
 932         .rtx_syn_ack    =       tcp_v6_send_synack,
 933         .send_ack       =       tcp_v6_reqsk_send_ack,
 934         .destructor     =       tcp_v6_reqsk_destructor,
 935         .send_reset     =       tcp_v6_send_reset
 936 };
 937
 938 #ifdef CONFIG_TCP_MD5SIG
 939 static struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 940         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 941 };
 942 #endif
 943
 944 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 945         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
 946         .twsk_unique    = tcp_twsk_unique,
 947         .twsk_destructor= tcp_twsk_destructor,
 948 };
 949
 950 static void tcp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb)
 951 {
 952         struct ipv6_pinfo *np = inet6_sk(sk);
 953         struct tcphdr *th = tcp_hdr(skb);
 954
 955         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 956                 th->check = ~csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,  0);
 957                 skb->csum_start = skb_transport_header(skb) - skb->head;
 958                 skb->csum_offset = offsetof(struct tcphdr, check);
 959         } else {
 960                 th->check = csum_ipv6_magic(&np->saddr, &np->daddr, len, IPPROTO_TCP,
 961                                             csum_partial((char *)th, th->doff<<2,
 962                                                          skb->csum));
 963         }
 964 }
 965
 966 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 967 {
 968         struct ipv6hdr *ipv6h;
 969         struct tcphdr *th;
 970
 971         if (!pskb_may_pull(skb, sizeof(*th)))
 972                 return -EINVAL;
 973
 974         ipv6h = ipv6_hdr(skb);
 975         th = tcp_hdr(skb);
 976
 977         th->check = 0;
 978         th->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
 979                                      IPPROTO_TCP, 0);
 980         skb->csum_start = skb_transport_header(skb) - skb->head;
 981         skb->csum_offset = offsetof(struct tcphdr, check);
 982         skb->ip_summed = CHECKSUM_PARTIAL;
 983         return 0;
 984 }
 985
 986 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 987 {
 988         struct tcphdr *th = tcp_hdr(skb), *t1;
 989         struct sk_buff *buff;
 990         struct flowi fl;
 991         unsigned int tot_len = sizeof(*th);
 992 #ifdef CONFIG_TCP_MD5SIG
 993         struct tcp_md5sig_key *key;
 994 #endif
 995
 996         if (th->rst)
 997                 return;
 998
 999         if (!ipv6_unicast_destination(skb))
1000                 return;
1001
1002 #ifdef CONFIG_TCP_MD5SIG
1003         if (sk)
1004                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1005         else
1006                 key = NULL;
1007
1008         if (key)
1009                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1010 #endif
1011
1012         /*
1013          * We need to grab some memory, and put together an RST,
1014          * and then put it into the queue to be sent.
1015          */
1016
1017         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1018                          GFP_ATOMIC);
1019         if (buff == NULL)
1020                 return;
1021
1022         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1023
1024         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1025
1026         /* Swap the send and the receive. */
1027         memset(t1, 0, sizeof(*t1));
1028         t1->dest = th->source;
1029         t1->source = th->dest;
1030         t1->doff = tot_len / 4;
1031         t1->rst = 1;
1032
1033         if(th->ack) {
1034                 t1->seq = th->ack_seq;
1035         } else {
1036                 t1->ack = 1;
1037                 t1->ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
1038                                     + skb->len - (th->doff<<2));
1039         }
1040
1041 #ifdef CONFIG_TCP_MD5SIG
1042         if (key) {
1043                 __be32 *opt = (__be32*)(t1 + 1);
1044                 opt[0] = htonl((TCPOPT_NOP << 24) |
1045                                (TCPOPT_NOP << 16) |
1046                                (TCPOPT_MD5SIG << 8) |
1047                                TCPOLEN_MD5SIG);
1048                 tcp_v6_do_calc_md5_hash((__u8 *)&opt[1], key,
1049                                         &ipv6_hdr(skb)->daddr,
1050                                         &ipv6_hdr(skb)->saddr,
1051                                         t1, IPPROTO_TCP, tot_len);
1052         }
1053 #endif
1054
1055         buff->csum = csum_partial((char *)t1, sizeof(*t1), 0);
1056
1057         memset(&fl, 0, sizeof(fl));
1058         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1059         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1060
1061         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1062                                     sizeof(*t1), IPPROTO_TCP,
1063                                     buff->csum);
1064
1065         fl.proto = IPPROTO_TCP;
1066         fl.oif = inet6_iif(skb);
1067         fl.fl_ip_dport = t1->dest;
1068         fl.fl_ip_sport = t1->source;
1069         security_skb_classify_flow(skb, &fl);
1070
1071         /* Pass a socket to ip6_dst_lookup either it is for RST
1072          * Underlying function will use this to retrieve the network
1073          * namespace
1074          */
1075         if (!ip6_dst_lookup(init_net.ipv6.tcp_sk, &buff->dst, &fl)) {
1076
1077                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1078                         ip6_xmit(init_net.ipv6.tcp_sk,
1079                                  buff, &fl, NULL, 0);
1080                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1081                         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
1082                         return;
1083                 }
1084         }
1085
1086         kfree_skb(buff);
1087 }
1088
1089 static void tcp_v6_send_ack(struct tcp_timewait_sock *tw,
1090                             struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
1091 {
1092         struct tcphdr *th = tcp_hdr(skb), *t1;
1093         struct sk_buff *buff;
1094         struct flowi fl;
1095         unsigned int tot_len = sizeof(struct tcphdr);
1096         __be32 *topt;
1097 #ifdef CONFIG_TCP_MD5SIG
1098         struct tcp_md5sig_key *key;
1099         struct tcp_md5sig_key tw_key;
1100 #endif
1101
1102 #ifdef CONFIG_TCP_MD5SIG
1103         if (!tw && skb->sk) {
1104                 key = tcp_v6_md5_do_lookup(skb->sk, &ipv6_hdr(skb)->daddr);
1105         } else if (tw && tw->tw_md5_keylen) {
1106                 tw_key.key = tw->tw_md5_key;
1107                 tw_key.keylen = tw->tw_md5_keylen;
1108                 key = &tw_key;
1109         } else {
1110                 key = NULL;
1111         }
1112 #endif
1113
1114         if (ts)
1115                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
1116 #ifdef CONFIG_TCP_MD5SIG
1117         if (key)
1118                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
1119 #endif
1120
1121         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1122                          GFP_ATOMIC);
1123         if (buff == NULL)
1124                 return;
1125
1126         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1127
1128         t1 = (struct tcphdr *) skb_push(buff,tot_len);
1129
1130         /* Swap the send and the receive. */
1131         memset(t1, 0, sizeof(*t1));
1132         t1->dest = th->source;
1133         t1->source = th->dest;
1134         t1->doff = tot_len/4;
1135         t1->seq = htonl(seq);
1136         t1->ack_seq = htonl(ack);
1137         t1->ack = 1;
1138         t1->window = htons(win);
1139
1140         topt = (__be32 *)(t1 + 1);
1141
1142         if (ts) {
1143                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1144                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1145                 *topt++ = htonl(tcp_time_stamp);
1146                 *topt = htonl(ts);
1147         }
1148
1149 #ifdef CONFIG_TCP_MD5SIG
1150         if (key) {
1151                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1152                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1153                 tcp_v6_do_calc_md5_hash((__u8 *)topt, key,
1154                                         &ipv6_hdr(skb)->daddr,
1155                                         &ipv6_hdr(skb)->saddr,
1156                                         t1, IPPROTO_TCP, tot_len);
1157         }
1158 #endif
1159
1160         buff->csum = csum_partial((char *)t1, tot_len, 0);
1161
1162         memset(&fl, 0, sizeof(fl));
1163         ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr);
1164         ipv6_addr_copy(&fl.fl6_src, &ipv6_hdr(skb)->daddr);
1165
1166         t1->check = csum_ipv6_magic(&fl.fl6_src, &fl.fl6_dst,
1167                                     tot_len, IPPROTO_TCP,
1168                                     buff->csum);
1169
1170         fl.proto = IPPROTO_TCP;
1171         fl.oif = inet6_iif(skb);
1172         fl.fl_ip_dport = t1->dest;
1173         fl.fl_ip_sport = t1->source;
1174         security_skb_classify_flow(skb, &fl);
1175
1176         if (!ip6_dst_lookup(init_net.ipv6.tcp_sk, &buff->dst, &fl)) {
1177                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
1178                         ip6_xmit(init_net.ipv6.tcp_sk,
1179                                  buff, &fl, NULL, 0);
1180                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
1181                         return;
1182                 }
1183         }
1184
1185         kfree_skb(buff);
1186 }
1187
1188 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1189 {
1190         struct inet_timewait_sock *tw = inet_twsk(sk);
1191         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1192
1193         tcp_v6_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1194                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1195                         tcptw->tw_ts_recent);
1196
1197         inet_twsk_put(tw);
1198 }
1199
1200 static void tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
1201 {
1202         tcp_v6_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent);
1203 }
1204
1205
1206 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1207 {
1208         struct request_sock *req, **prev;
1209         const struct tcphdr *th = tcp_hdr(skb);
1210         struct sock *nsk;
1211
1212         /* Find possible connection requests. */
1213         req = inet6_csk_search_req(sk, &prev, th->source,
1214                                    &ipv6_hdr(skb)->saddr,
1215                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1216         if (req)
1217                 return tcp_check_req(sk, skb, req, prev);
1218
1219         nsk = __inet6_lookup_established(sk->sk_net, &tcp_hashinfo,
1220                         &ipv6_hdr(skb)->saddr, th->source,
1221                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1222
1223         if (nsk) {
1224                 if (nsk->sk_state != TCP_TIME_WAIT) {
1225                         bh_lock_sock(nsk);
1226                         return nsk;
1227                 }
1228                 inet_twsk_put(inet_twsk(nsk));
1229                 return NULL;
1230         }
1231
1232 #ifdef CONFIG_SYN_COOKIES
1233         if (!th->rst && !th->syn && th->ack)
1234                 sk = cookie_v6_check(sk, skb);
1235 #endif
1236         return sk;
1237 }
1238
1239 /* FIXME: this is substantially similar to the ipv4 code.
1240  * Can some kind of merge be done? -- erics
1241  */
1242 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1243 {
1244         struct inet6_request_sock *treq;
1245         struct ipv6_pinfo *np = inet6_sk(sk);
1246         struct tcp_options_received tmp_opt;
1247         struct tcp_sock *tp = tcp_sk(sk);
1248         struct request_sock *req = NULL;
1249         __u32 isn = TCP_SKB_CB(skb)->when;
1250 #ifdef CONFIG_SYN_COOKIES
1251         int want_cookie = 0;
1252 #else
1253 #define want_cookie 0
1254 #endif
1255
1256         if (skb->protocol == htons(ETH_P_IP))
1257                 return tcp_v4_conn_request(sk, skb);
1258
1259         if (!ipv6_unicast_destination(skb))
1260                 goto drop;
1261
1262         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1263                 if (net_ratelimit())
1264                         syn_flood_warning(skb);
1265 #ifdef CONFIG_SYN_COOKIES
1266                 if (sysctl_tcp_syncookies)
1267                         want_cookie = 1;
1268                 else
1269 #endif
1270                 goto drop;
1271         }
1272
1273         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1274                 goto drop;
1275
1276         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1277         if (req == NULL)
1278                 goto drop;
1279
1280 #ifdef CONFIG_TCP_MD5SIG
1281         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1282 #endif
1283
1284         tcp_clear_options(&tmp_opt);
1285         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1286         tmp_opt.user_mss = tp->rx_opt.user_mss;
1287
1288         tcp_parse_options(skb, &tmp_opt, 0);
1289
1290         if (want_cookie) {
1291                 tcp_clear_options(&tmp_opt);
1292                 tmp_opt.saw_tstamp = 0;
1293         }
1294
1295         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1296         tcp_openreq_init(req, &tmp_opt, skb);
1297
1298         treq = inet6_rsk(req);
1299         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1300         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1301         treq->pktopts = NULL;
1302         if (!want_cookie)
1303                 TCP_ECN_create_request(req, tcp_hdr(skb));
1304
1305         if (want_cookie) {
1306                 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1307         } else if (!isn) {
1308                 if (ipv6_opt_accepted(sk, skb) ||
1309                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1310                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1311                         atomic_inc(&skb->users);
1312                         treq->pktopts = skb;
1313                 }
1314                 treq->iif = sk->sk_bound_dev_if;
1315
1316                 /* So that link locals have meaning */
1317                 if (!sk->sk_bound_dev_if &&
1318                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1319                         treq->iif = inet6_iif(skb);
1320
1321                 isn = tcp_v6_init_sequence(skb);
1322         }
1323
1324         tcp_rsk(req)->snt_isn = isn;
1325
1326         security_inet_conn_request(sk, skb, req);
1327
1328         if (tcp_v6_send_synack(sk, req))
1329                 goto drop;
1330
1331         if (!want_cookie) {
1332                 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1333                 return 0;
1334         }
1335
1336 drop:
1337         if (req)
1338                 reqsk_free(req);
1339
1340         return 0; /* don't send reset */
1341 }
1342
1343 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1344                                           struct request_sock *req,
1345                                           struct dst_entry *dst)
1346 {
1347         struct inet6_request_sock *treq = inet6_rsk(req);
1348         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1349         struct tcp6_sock *newtcp6sk;
1350         struct inet_sock *newinet;
1351         struct tcp_sock *newtp;
1352         struct sock *newsk;
1353         struct ipv6_txoptions *opt;
1354 #ifdef CONFIG_TCP_MD5SIG
1355         struct tcp_md5sig_key *key;
1356 #endif
1357
1358         if (skb->protocol == htons(ETH_P_IP)) {
1359                 /*
1360                  *      v6 mapped
1361                  */
1362
1363                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1364
1365                 if (newsk == NULL)
1366                         return NULL;
1367
1368                 newtcp6sk = (struct tcp6_sock *)newsk;
1369                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1370
1371                 newinet = inet_sk(newsk);
1372                 newnp = inet6_sk(newsk);
1373                 newtp = tcp_sk(newsk);
1374
1375                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1376
1377                 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
1378                               newinet->daddr);
1379
1380                 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
1381                               newinet->saddr);
1382
1383                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1384
1385                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1386                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1387 #ifdef CONFIG_TCP_MD5SIG
1388                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1389 #endif
1390
1391                 newnp->pktoptions  = NULL;
1392                 newnp->opt         = NULL;
1393                 newnp->mcast_oif   = inet6_iif(skb);
1394                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1395
1396                 /*
1397                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1398                  * here, tcp_create_openreq_child now does this for us, see the comment in
1399                  * that function for the gory details. -acme
1400                  */
1401
1402                 /* It is tricky place. Until this moment IPv4 tcp
1403                    worked with IPv6 icsk.icsk_af_ops.
1404                    Sync it now.
1405                  */
1406                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1407
1408                 return newsk;
1409         }
1410
1411         opt = np->opt;
1412
1413         if (sk_acceptq_is_full(sk))
1414                 goto out_overflow;
1415
1416         if (dst == NULL) {
1417                 struct in6_addr *final_p = NULL, final;
1418                 struct flowi fl;
1419
1420                 memset(&fl, 0, sizeof(fl));
1421                 fl.proto = IPPROTO_TCP;
1422                 ipv6_addr_copy(&fl.fl6_dst, &treq->rmt_addr);
1423                 if (opt && opt->srcrt) {
1424                         struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1425                         ipv6_addr_copy(&final, &fl.fl6_dst);
1426                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1427                         final_p = &final;
1428                 }
1429                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
1430                 fl.oif = sk->sk_bound_dev_if;
1431                 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
1432                 fl.fl_ip_sport = inet_sk(sk)->sport;
1433                 security_req_classify_flow(req, &fl);
1434
1435                 if (ip6_dst_lookup(sk, &dst, &fl))
1436                         goto out;
1437
1438                 if (final_p)
1439                         ipv6_addr_copy(&fl.fl6_dst, final_p);
1440
1441                 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
1442                         goto out;
1443         }
1444
1445         newsk = tcp_create_openreq_child(sk, req, skb);
1446         if (newsk == NULL)
1447                 goto out;
1448
1449         /*
1450          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1451          * count here, tcp_create_openreq_child now does this for us, see the
1452          * comment in that function for the gory details. -acme
1453          */
1454
1455         newsk->sk_gso_type = SKB_GSO_TCPV6;
1456         __ip6_dst_store(newsk, dst, NULL, NULL);
1457
1458         newtcp6sk = (struct tcp6_sock *)newsk;
1459         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1460
1461         newtp = tcp_sk(newsk);
1462         newinet = inet_sk(newsk);
1463         newnp = inet6_sk(newsk);
1464
1465         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1466
1467         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1468         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1469         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1470         newsk->sk_bound_dev_if = treq->iif;
1471
1472         /* Now IPv6 options...
1473
1474            First: no IPv4 options.
1475          */
1476         newinet->opt = NULL;
1477         newnp->ipv6_fl_list = NULL;
1478
1479         /* Clone RX bits */
1480         newnp->rxopt.all = np->rxopt.all;
1481
1482         /* Clone pktoptions received with SYN */
1483         newnp->pktoptions = NULL;
1484         if (treq->pktopts != NULL) {
1485                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1486                 kfree_skb(treq->pktopts);
1487                 treq->pktopts = NULL;
1488                 if (newnp->pktoptions)
1489                         skb_set_owner_r(newnp->pktoptions, newsk);
1490         }
1491         newnp->opt        = NULL;
1492         newnp->mcast_oif  = inet6_iif(skb);
1493         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1494
1495         /* Clone native IPv6 options from listening socket (if any)
1496
1497            Yes, keeping reference count would be much more clever,
1498            but we make one more one thing there: reattach optmem
1499            to newsk.
1500          */
1501         if (opt) {
1502                 newnp->opt = ipv6_dup_options(newsk, opt);
1503                 if (opt != np->opt)
1504                         sock_kfree_s(sk, opt, opt->tot_len);
1505         }
1506
1507         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1508         if (newnp->opt)
1509                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1510                                                      newnp->opt->opt_flen);
1511
1512         tcp_mtup_init(newsk);
1513         tcp_sync_mss(newsk, dst_mtu(dst));
1514         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1515         tcp_initialize_rcv_mss(newsk);
1516
1517         newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
1518
1519 #ifdef CONFIG_TCP_MD5SIG
1520         /* Copy over the MD5 key from the original socket */
1521         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1522                 /* We're using one, so create a matching key
1523                  * on the newsk structure. If we fail to get
1524                  * memory, then we end up not copying the key
1525                  * across. Shucks.
1526                  */
1527                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1528                 if (newkey != NULL)
1529                         tcp_v6_md5_do_add(newsk, &inet6_sk(sk)->daddr,
1530                                           newkey, key->keylen);
1531         }
1532 #endif
1533
1534         __inet6_hash(newsk);
1535         inet_inherit_port(sk, newsk);
1536
1537         return newsk;
1538
1539 out_overflow:
1540         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
1541 out:
1542         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
1543         if (opt && opt != np->opt)
1544                 sock_kfree_s(sk, opt, opt->tot_len);
1545         dst_release(dst);
1546         return NULL;
1547 }
1548
1549 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1550 {
1551         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1552                 if (!tcp_v6_check(tcp_hdr(skb), skb->len, &ipv6_hdr(skb)->saddr,
1553                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1554                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1555                         return 0;
1556                 }
1557         }
1558
1559         skb->csum = ~csum_unfold(tcp_v6_check(tcp_hdr(skb), skb->len,
1560                                               &ipv6_hdr(skb)->saddr,
1561                                               &ipv6_hdr(skb)->daddr, 0));
1562
1563         if (skb->len <= 76) {
1564                 return __skb_checksum_complete(skb);
1565         }
1566         return 0;
1567 }
1568
1569 /* The socket must have it's spinlock held when we get
1570  * here.
1571  *
1572  * We have a potential double-lock case here, so even when
1573  * doing backlog processing we use the BH locking scheme.
1574  * This is because we cannot sleep with the original spinlock
1575  * held.
1576  */
1577 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1578 {
1579         struct ipv6_pinfo *np = inet6_sk(sk);
1580         struct tcp_sock *tp;
1581         struct sk_buff *opt_skb = NULL;
1582
1583         /* Imagine: socket is IPv6. IPv4 packet arrives,
1584            goes to IPv4 receive handler and backlogged.
1585            From backlog it always goes here. Kerboom...
1586            Fortunately, tcp_rcv_established and rcv_established
1587            handle them correctly, but it is not case with
1588            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1589          */
1590
1591         if (skb->protocol == htons(ETH_P_IP))
1592                 return tcp_v4_do_rcv(sk, skb);
1593
1594 #ifdef CONFIG_TCP_MD5SIG
1595         if (tcp_v6_inbound_md5_hash (sk, skb))
1596                 goto discard;
1597 #endif
1598
1599         if (sk_filter(sk, skb))
1600                 goto discard;
1601
1602         /*
1603          *      socket locking is here for SMP purposes as backlog rcv
1604          *      is currently called with bh processing disabled.
1605          */
1606
1607         /* Do Stevens' IPV6_PKTOPTIONS.
1608
1609            Yes, guys, it is the only place in our code, where we
1610            may make it not affecting IPv4.
1611            The rest of code is protocol independent,
1612            and I do not like idea to uglify IPv4.
1613
1614            Actually, all the idea behind IPV6_PKTOPTIONS
1615            looks not very well thought. For now we latch
1616            options, received in the last packet, enqueued
1617            by tcp. Feel free to propose better solution.
1618                                                --ANK (980728)
1619          */
1620         if (np->rxopt.all)
1621                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1622
1623         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1624                 TCP_CHECK_TIMER(sk);
1625                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1626                         goto reset;
1627                 TCP_CHECK_TIMER(sk);
1628                 if (opt_skb)
1629                         goto ipv6_pktoptions;
1630                 return 0;
1631         }
1632
1633         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1634                 goto csum_err;
1635
1636         if (sk->sk_state == TCP_LISTEN) {
1637                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1638                 if (!nsk)
1639                         goto discard;
1640
1641                 /*
1642                  * Queue it on the new socket if the new socket is active,
1643                  * otherwise we just shortcircuit this and continue with
1644                  * the new socket..
1645                  */
1646                 if(nsk != sk) {
1647                         if (tcp_child_process(sk, nsk, skb))
1648                                 goto reset;
1649                         if (opt_skb)
1650                                 __kfree_skb(opt_skb);
1651                         return 0;
1652                 }
1653         }
1654
1655         TCP_CHECK_TIMER(sk);
1656         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1657                 goto reset;
1658         TCP_CHECK_TIMER(sk);
1659         if (opt_skb)
1660                 goto ipv6_pktoptions;
1661         return 0;
1662
1663 reset:
1664         tcp_v6_send_reset(sk, skb);
1665 discard:
1666         if (opt_skb)
1667                 __kfree_skb(opt_skb);
1668         kfree_skb(skb);
1669         return 0;
1670 csum_err:
1671         TCP_INC_STATS_BH(TCP_MIB_INERRS);
1672         goto discard;
1673
1674
1675 ipv6_pktoptions:
1676         /* Do you ask, what is it?
1677
1678            1. skb was enqueued by tcp.
1679            2. skb is added to tail of read queue, rather than out of order.
1680            3. socket is not in passive state.
1681            4. Finally, it really contains options, which user wants to receive.
1682          */
1683         tp = tcp_sk(sk);
1684         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1685             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1686                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1687                         np->mcast_oif = inet6_iif(opt_skb);
1688                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1689                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1690                 if (ipv6_opt_accepted(sk, opt_skb)) {
1691                         skb_set_owner_r(opt_skb, sk);
1692                         opt_skb = xchg(&np->pktoptions, opt_skb);
1693                 } else {
1694                         __kfree_skb(opt_skb);
1695                         opt_skb = xchg(&np->pktoptions, NULL);
1696                 }
1697         }
1698
1699         if (opt_skb)
1700                 kfree_skb(opt_skb);
1701         return 0;
1702 }
1703
1704 static int tcp_v6_rcv(struct sk_buff *skb)
1705 {
1706         struct tcphdr *th;
1707         struct sock *sk;
1708         int ret;
1709
1710         if (skb->pkt_type != PACKET_HOST)
1711                 goto discard_it;
1712
1713         /*
1714          *      Count it even if it's bad.
1715          */
1716         TCP_INC_STATS_BH(TCP_MIB_INSEGS);
1717
1718         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1719                 goto discard_it;
1720
1721         th = tcp_hdr(skb);
1722
1723         if (th->doff < sizeof(struct tcphdr)/4)
1724                 goto bad_packet;
1725         if (!pskb_may_pull(skb, th->doff*4))
1726                 goto discard_it;
1727
1728         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1729                 goto bad_packet;
1730
1731         th = tcp_hdr(skb);
1732         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1733         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1734                                     skb->len - th->doff*4);
1735         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1736         TCP_SKB_CB(skb)->when = 0;
1737         TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(ipv6_hdr(skb));
1738         TCP_SKB_CB(skb)->sacked = 0;
1739
1740         sk = __inet6_lookup(skb->dev->nd_net, &tcp_hashinfo,
1741                         &ipv6_hdr(skb)->saddr, th->source,
1742                         &ipv6_hdr(skb)->daddr, ntohs(th->dest),
1743                         inet6_iif(skb));
1744
1745         if (!sk)
1746                 goto no_tcp_socket;
1747
1748 process:
1749         if (sk->sk_state == TCP_TIME_WAIT)
1750                 goto do_time_wait;
1751
1752         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1753                 goto discard_and_relse;
1754
1755         if (sk_filter(sk, skb))
1756                 goto discard_and_relse;
1757
1758         skb->dev = NULL;
1759
1760         bh_lock_sock_nested(sk);
1761         ret = 0;
1762         if (!sock_owned_by_user(sk)) {
1763 #ifdef CONFIG_NET_DMA
1764                 struct tcp_sock *tp = tcp_sk(sk);
1765                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1766                         tp->ucopy.dma_chan = get_softnet_dma();
1767                 if (tp->ucopy.dma_chan)
1768                         ret = tcp_v6_do_rcv(sk, skb);
1769                 else
1770 #endif
1771                 {
1772                         if (!tcp_prequeue(sk, skb))
1773                                 ret = tcp_v6_do_rcv(sk, skb);
1774                 }
1775         } else
1776                 sk_add_backlog(sk, skb);
1777         bh_unlock_sock(sk);
1778
1779         sock_put(sk);
1780         return ret ? -1 : 0;
1781
1782 no_tcp_socket:
1783         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1784                 goto discard_it;
1785
1786         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1787 bad_packet:
1788                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1789         } else {
1790                 tcp_v6_send_reset(NULL, skb);
1791         }
1792
1793 discard_it:
1794
1795         /*
1796          *      Discard frame
1797          */
1798
1799         kfree_skb(skb);
1800         return 0;
1801
1802 discard_and_relse:
1803         sock_put(sk);
1804         goto discard_it;
1805
1806 do_time_wait:
1807         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1808                 inet_twsk_put(inet_twsk(sk));
1809                 goto discard_it;
1810         }
1811
1812         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1813                 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1814                 inet_twsk_put(inet_twsk(sk));
1815                 goto discard_it;
1816         }
1817
1818         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1819         case TCP_TW_SYN:
1820         {
1821                 struct sock *sk2;
1822
1823                 sk2 = inet6_lookup_listener(skb->dev->nd_net, &tcp_hashinfo,
1824                                             &ipv6_hdr(skb)->daddr,
1825                                             ntohs(th->dest), inet6_iif(skb));
1826                 if (sk2 != NULL) {
1827                         struct inet_timewait_sock *tw = inet_twsk(sk);
1828                         inet_twsk_deschedule(tw, &tcp_death_row);
1829                         inet_twsk_put(tw);
1830                         sk = sk2;
1831                         goto process;
1832                 }
1833                 /* Fall through to ACK */
1834         }
1835         case TCP_TW_ACK:
1836                 tcp_v6_timewait_ack(sk, skb);
1837                 break;
1838         case TCP_TW_RST:
1839                 goto no_tcp_socket;
1840         case TCP_TW_SUCCESS:;
1841         }
1842         goto discard_it;
1843 }
1844
1845 static int tcp_v6_remember_stamp(struct sock *sk)
1846 {
1847         /* Alas, not yet... */
1848         return 0;
1849 }
1850
1851 static struct inet_connection_sock_af_ops ipv6_specific = {
1852         .queue_xmit        = inet6_csk_xmit,
1853         .send_check        = tcp_v6_send_check,
1854         .rebuild_header    = inet6_sk_rebuild_header,
1855         .conn_request      = tcp_v6_conn_request,
1856         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1857         .remember_stamp    = tcp_v6_remember_stamp,
1858         .net_header_len    = sizeof(struct ipv6hdr),
1859         .setsockopt        = ipv6_setsockopt,
1860         .getsockopt        = ipv6_getsockopt,
1861         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1862         .sockaddr_len      = sizeof(struct sockaddr_in6),
1863         .bind_conflict     = inet6_csk_bind_conflict,
1864 #ifdef CONFIG_COMPAT
1865         .compat_setsockopt = compat_ipv6_setsockopt,
1866         .compat_getsockopt = compat_ipv6_getsockopt,
1867 #endif
1868 };
1869
1870 #ifdef CONFIG_TCP_MD5SIG
1871 static struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1872         .md5_lookup     =       tcp_v6_md5_lookup,
1873         .calc_md5_hash  =       tcp_v6_calc_md5_hash,
1874         .md5_add        =       tcp_v6_md5_add_func,
1875         .md5_parse      =       tcp_v6_parse_md5_keys,
1876 };
1877 #endif
1878
1879 /*
1880  *      TCP over IPv4 via INET6 API
1881  */
1882
1883 static struct inet_connection_sock_af_ops ipv6_mapped = {
1884         .queue_xmit        = ip_queue_xmit,
1885         .send_check        = tcp_v4_send_check,
1886         .rebuild_header    = inet_sk_rebuild_header,
1887         .conn_request      = tcp_v6_conn_request,
1888         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1889         .remember_stamp    = tcp_v4_remember_stamp,
1890         .net_header_len    = sizeof(struct iphdr),
1891         .setsockopt        = ipv6_setsockopt,
1892         .getsockopt        = ipv6_getsockopt,
1893         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1894         .sockaddr_len      = sizeof(struct sockaddr_in6),
1895         .bind_conflict     = inet6_csk_bind_conflict,
1896 #ifdef CONFIG_COMPAT
1897         .compat_setsockopt = compat_ipv6_setsockopt,
1898         .compat_getsockopt = compat_ipv6_getsockopt,
1899 #endif
1900 };
1901
1902 #ifdef CONFIG_TCP_MD5SIG
1903 static struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1904         .md5_lookup     =       tcp_v4_md5_lookup,
1905         .calc_md5_hash  =       tcp_v4_calc_md5_hash,
1906         .md5_add        =       tcp_v6_md5_add_func,
1907         .md5_parse      =       tcp_v6_parse_md5_keys,
1908 };
1909 #endif
1910
1911 /* NOTE: A lot of things set to zero explicitly by call to
1912  *       sk_alloc() so need not be done here.
1913  */
1914 static int tcp_v6_init_sock(struct sock *sk)
1915 {
1916         struct inet_connection_sock *icsk = inet_csk(sk);
1917         struct tcp_sock *tp = tcp_sk(sk);
1918
1919         skb_queue_head_init(&tp->out_of_order_queue);
1920         tcp_init_xmit_timers(sk);
1921         tcp_prequeue_init(tp);
1922
1923         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1924         tp->mdev = TCP_TIMEOUT_INIT;
1925
1926         /* So many TCP implementations out there (incorrectly) count the
1927          * initial SYN frame in their delayed-ACK and congestion control
1928          * algorithms that we must have the following bandaid to talk
1929          * efficiently to them.  -DaveM
1930          */
1931         tp->snd_cwnd = 2;
1932
1933         /* See draft-stevens-tcpca-spec-01 for discussion of the
1934          * initialization of these values.
1935          */
1936         tp->snd_ssthresh = 0x7fffffff;
1937         tp->snd_cwnd_clamp = ~0;
1938         tp->mss_cache = 536;
1939
1940         tp->reordering = sysctl_tcp_reordering;
1941
1942         sk->sk_state = TCP_CLOSE;
1943
1944         icsk->icsk_af_ops = &ipv6_specific;
1945         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1946         icsk->icsk_sync_mss = tcp_sync_mss;
1947         sk->sk_write_space = sk_stream_write_space;
1948         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1949
1950 #ifdef CONFIG_TCP_MD5SIG
1951         tp->af_specific = &tcp_sock_ipv6_specific;
1952 #endif
1953
1954         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1955         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1956
1957         atomic_inc(&tcp_sockets_allocated);
1958
1959         return 0;
1960 }
1961
1962 static int tcp_v6_destroy_sock(struct sock *sk)
1963 {
1964 #ifdef CONFIG_TCP_MD5SIG
1965         /* Clean up the MD5 key list */
1966         if (tcp_sk(sk)->md5sig_info)
1967                 tcp_v6_clear_md5_list(sk);
1968 #endif
1969         tcp_v4_destroy_sock(sk);
1970         return inet6_destroy_sock(sk);
1971 }
1972
1973 #ifdef CONFIG_PROC_FS
1974 /* Proc filesystem TCPv6 sock list dumping. */
1975 static void get_openreq6(struct seq_file *seq,
1976                          struct sock *sk, struct request_sock *req, int i, int uid)
1977 {
1978         int ttd = req->expires - jiffies;
1979         struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1980         struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1981
1982         if (ttd < 0)
1983                 ttd = 0;
1984
1985         seq_printf(seq,
1986                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1987                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
1988                    i,
1989                    src->s6_addr32[0], src->s6_addr32[1],
1990                    src->s6_addr32[2], src->s6_addr32[3],
1991                    ntohs(inet_sk(sk)->sport),
1992                    dest->s6_addr32[0], dest->s6_addr32[1],
1993                    dest->s6_addr32[2], dest->s6_addr32[3],
1994                    ntohs(inet_rsk(req)->rmt_port),
1995                    TCP_SYN_RECV,
1996                    0,0, /* could print option size, but that is af dependent. */
1997                    1,   /* timers active (only the expire timer) */
1998                    jiffies_to_clock_t(ttd),
1999                    req->retrans,
2000                    uid,
2001                    0,  /* non standard timer */
2002                    0, /* open_requests have no inode */
2003                    0, req);
2004 }
2005
2006 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2007 {
2008         struct in6_addr *dest, *src;
2009         __u16 destp, srcp;
2010         int timer_active;
2011         unsigned long timer_expires;
2012         struct inet_sock *inet = inet_sk(sp);
2013         struct tcp_sock *tp = tcp_sk(sp);
2014         const struct inet_connection_sock *icsk = inet_csk(sp);
2015         struct ipv6_pinfo *np = inet6_sk(sp);
2016
2017         dest  = &np->daddr;
2018         src   = &np->rcv_saddr;
2019         destp = ntohs(inet->dport);
2020         srcp  = ntohs(inet->sport);
2021
2022         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2023                 timer_active    = 1;
2024                 timer_expires   = icsk->icsk_timeout;
2025         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2026                 timer_active    = 4;
2027                 timer_expires   = icsk->icsk_timeout;
2028         } else if (timer_pending(&sp->sk_timer)) {
2029                 timer_active    = 2;
2030                 timer_expires   = sp->sk_timer.expires;
2031         } else {
2032                 timer_active    = 0;
2033                 timer_expires = jiffies;
2034         }
2035
2036         seq_printf(seq,
2037                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2038                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d\n",
2039                    i,
2040                    src->s6_addr32[0], src->s6_addr32[1],
2041                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2042                    dest->s6_addr32[0], dest->s6_addr32[1],
2043                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2044                    sp->sk_state,
2045                    tp->write_seq-tp->snd_una,
2046                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2047                    timer_active,
2048                    jiffies_to_clock_t(timer_expires - jiffies),
2049                    icsk->icsk_retransmits,
2050                    sock_i_uid(sp),
2051                    icsk->icsk_probes_out,
2052                    sock_i_ino(sp),
2053                    atomic_read(&sp->sk_refcnt), sp,
2054                    icsk->icsk_rto,
2055                    icsk->icsk_ack.ato,
2056                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2057                    tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
2058                    );
2059 }
2060
2061 static void get_timewait6_sock(struct seq_file *seq,
2062                                struct inet_timewait_sock *tw, int i)
2063 {
2064         struct in6_addr *dest, *src;
2065         __u16 destp, srcp;
2066         struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2067         int ttd = tw->tw_ttd - jiffies;
2068
2069         if (ttd < 0)
2070                 ttd = 0;
2071
2072         dest = &tw6->tw_v6_daddr;
2073         src  = &tw6->tw_v6_rcv_saddr;
2074         destp = ntohs(tw->tw_dport);
2075         srcp  = ntohs(tw->tw_sport);
2076
2077         seq_printf(seq,
2078                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2079                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p\n",
2080                    i,
2081                    src->s6_addr32[0], src->s6_addr32[1],
2082                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2083                    dest->s6_addr32[0], dest->s6_addr32[1],
2084                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2085                    tw->tw_substate, 0, 0,
2086                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2087                    atomic_read(&tw->tw_refcnt), tw);
2088 }
2089
2090 static int tcp6_seq_show(struct seq_file *seq, void *v)
2091 {
2092         struct tcp_iter_state *st;
2093
2094         if (v == SEQ_START_TOKEN) {
2095                 seq_puts(seq,
2096                          "  sl  "
2097                          "local_address                         "
2098                          "remote_address                        "
2099                          "st tx_queue rx_queue tr tm->when retrnsmt"
2100                          "   uid  timeout inode\n");
2101                 goto out;
2102         }
2103         st = seq->private;
2104
2105         switch (st->state) {
2106         case TCP_SEQ_STATE_LISTENING:
2107         case TCP_SEQ_STATE_ESTABLISHED:
2108                 get_tcp6_sock(seq, v, st->num);
2109                 break;
2110         case TCP_SEQ_STATE_OPENREQ:
2111                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2112                 break;
2113         case TCP_SEQ_STATE_TIME_WAIT:
2114                 get_timewait6_sock(seq, v, st->num);
2115                 break;
2116         }
2117 out:
2118         return 0;
2119 }
2120
2121 static struct file_operations tcp6_seq_fops;
2122 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2123         .owner          = THIS_MODULE,
2124         .name           = "tcp6",
2125         .family         = AF_INET6,
2126         .seq_show       = tcp6_seq_show,
2127         .seq_fops       = &tcp6_seq_fops,
2128 };
2129
2130 int __init tcp6_proc_init(void)
2131 {
2132         return tcp_proc_register(&tcp6_seq_afinfo);
2133 }
2134
2135 void tcp6_proc_exit(void)
2136 {
2137         tcp_proc_unregister(&tcp6_seq_afinfo);
2138 }
2139 #endif
2140
2141 DEFINE_PROTO_INUSE(tcpv6)
2142
2143 struct proto tcpv6_prot = {
2144         .name                   = "TCPv6",
2145         .owner                  = THIS_MODULE,
2146         .close                  = tcp_close,
2147         .connect                = tcp_v6_connect,
2148         .disconnect             = tcp_disconnect,
2149         .accept                 = inet_csk_accept,
2150         .ioctl                  = tcp_ioctl,
2151         .init                   = tcp_v6_init_sock,
2152         .destroy                = tcp_v6_destroy_sock,
2153         .shutdown               = tcp_shutdown,
2154         .setsockopt             = tcp_setsockopt,
2155         .getsockopt             = tcp_getsockopt,
2156         .recvmsg                = tcp_recvmsg,
2157         .backlog_rcv            = tcp_v6_do_rcv,
2158         .hash                   = tcp_v6_hash,
2159         .unhash                 = inet_unhash,
2160         .get_port               = inet_csk_get_port,
2161         .enter_memory_pressure  = tcp_enter_memory_pressure,
2162         .sockets_allocated      = &tcp_sockets_allocated,
2163         .memory_allocated       = &tcp_memory_allocated,
2164         .memory_pressure        = &tcp_memory_pressure,
2165         .orphan_count           = &tcp_orphan_count,
2166         .sysctl_mem             = sysctl_tcp_mem,
2167         .sysctl_wmem            = sysctl_tcp_wmem,
2168         .sysctl_rmem            = sysctl_tcp_rmem,
2169         .max_header             = MAX_TCP_HEADER,
2170         .obj_size               = sizeof(struct tcp6_sock),
2171         .twsk_prot              = &tcp6_timewait_sock_ops,
2172         .rsk_prot               = &tcp6_request_sock_ops,
2173         .hashinfo               = &tcp_hashinfo,
2174 #ifdef CONFIG_COMPAT
2175         .compat_setsockopt      = compat_tcp_setsockopt,
2176         .compat_getsockopt      = compat_tcp_getsockopt,
2177 #endif
2178         REF_PROTO_INUSE(tcpv6)
2179 };
2180
2181 static struct inet6_protocol tcpv6_protocol = {
2182         .handler        =       tcp_v6_rcv,
2183         .err_handler    =       tcp_v6_err,
2184         .gso_send_check =       tcp_v6_gso_send_check,
2185         .gso_segment    =       tcp_tso_segment,
2186         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2187 };
2188
2189 static struct inet_protosw tcpv6_protosw = {
2190         .type           =       SOCK_STREAM,
2191         .protocol       =       IPPROTO_TCP,
2192         .prot           =       &tcpv6_prot,
2193         .ops            =       &inet6_stream_ops,
2194         .capability     =       -1,
2195         .no_check       =       0,
2196         .flags          =       INET_PROTOSW_PERMANENT |
2197                                 INET_PROTOSW_ICSK,
2198 };
2199
2200 static int tcpv6_net_init(struct net *net)
2201 {
2202         int err;
2203         struct socket *sock;
2204         struct sock *sk;
2205
2206         err = inet_csk_ctl_sock_create(&sock, PF_INET6, SOCK_RAW, IPPROTO_TCP);
2207         if (err)
2208                 return err;
2209
2210         net->ipv6.tcp_sk = sk = sock->sk;
2211         sk_change_net(sk, net);
2212         return err;
2213 }
2214
2215 static void tcpv6_net_exit(struct net *net)
2216 {
2217         sk_release_kernel(net->ipv6.tcp_sk);
2218 }
2219
2220 static struct pernet_operations tcpv6_net_ops = {
2221         .init = tcpv6_net_init,
2222         .exit = tcpv6_net_exit,
2223 };
2224
2225 int __init tcpv6_init(void)
2226 {
2227         int ret;
2228
2229         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2230         if (ret)
2231                 goto out;
2232
2233         /* register inet6 protocol */
2234         ret = inet6_register_protosw(&tcpv6_protosw);
2235         if (ret)
2236                 goto out_tcpv6_protocol;
2237
2238         ret = register_pernet_subsys(&tcpv6_net_ops);
2239         if (ret)
2240                 goto out_tcpv6_protosw;
2241 out:
2242         return ret;
2243
2244 out_tcpv6_protocol:
2245         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2246 out_tcpv6_protosw:
2247         inet6_unregister_protosw(&tcpv6_protosw);
2248         goto out;
2249 }
2250
2251 void tcpv6_exit(void)
2252 {
2253         unregister_pernet_subsys(&tcpv6_net_ops);
2254         inet6_unregister_protosw(&tcpv6_protosw);
2255         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2256 }