net/ipv6/tcp_ipv6.c

   1 /*
   2  *      TCP over IPv6
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on:
   9  *      linux/net/ipv4/tcp.c
  10  *      linux/net/ipv4/tcp_input.c
  11  *      linux/net/ipv4/tcp_output.c
  12  *
  13  *      Fixes:
  14  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  15  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  16  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  17  *                                      a single port at the same time.
  18  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/tcp6 to seq_file.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  */
  25
  26 #include <linux/bottom_half.h>
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/types.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/in.h>
  35 #include <linux/in6.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/init.h>
  38 #include <linux/jhash.h>
  39 #include <linux/ipsec.h>
  40 #include <linux/times.h>
  41 #include <linux/slab.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 #include <net/inet_common.h>
  64 #include <net/secure_seq.h>
  65
  66 #include <asm/uaccess.h>
  67
  68 #include <linux/proc_fs.h>
  69 #include <linux/seq_file.h>
  70
  71 #include <linux/crypto.h>
  72 #include <linux/scatterlist.h>
  73
  74 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
  75 static void     tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  76                                       struct request_sock *req);
  77
  78 static int      tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  79 static void     __tcp_v6_send_check(struct sk_buff *skb,
  80                                     const struct in6_addr *saddr,
  81                                     const struct in6_addr *daddr);
  82
  83 static const struct inet_connection_sock_af_ops ipv6_mapped;
  84 static const struct inet_connection_sock_af_ops ipv6_specific;
  85 #ifdef CONFIG_TCP_MD5SIG
  86 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  87 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
  88 #else
  89 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
  90                                                    const struct in6_addr *addr)
  91 {
  92         return NULL;
  93 }
  94 #endif
  95
  96 static void tcp_v6_hash(struct sock *sk)
  97 {
  98         if (sk->sk_state != TCP_CLOSE) {
  99                 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
 100                         tcp_prot.hash(sk);
 101                         return;
 102                 }
 103                 local_bh_disable();
 104                 __inet6_hash(sk, NULL);
 105                 local_bh_enable();
 106         }
 107 }
 108
 109 static __inline__ __sum16 tcp_v6_check(int len,
 110                                    const struct in6_addr *saddr,
 111                                    const struct in6_addr *daddr,
 112                                    __wsum base)
 113 {
 114         return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
 115 }
 116
 117 static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
 118 {
 119         return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 120                                             ipv6_hdr(skb)->saddr.s6_addr32,
 121                                             tcp_hdr(skb)->dest,
 122                                             tcp_hdr(skb)->source);
 123 }
 124
 125 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 126                           int addr_len)
 127 {
 128         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 129         struct inet_sock *inet = inet_sk(sk);
 130         struct inet_connection_sock *icsk = inet_csk(sk);
 131         struct ipv6_pinfo *np = inet6_sk(sk);
 132         struct tcp_sock *tp = tcp_sk(sk);
 133         struct in6_addr *saddr = NULL, *final_p, final;
 134         struct rt6_info *rt;
 135         struct flowi6 fl6;
 136         struct dst_entry *dst;
 137         int addr_type;
 138         int err;
 139
 140         if (addr_len < SIN6_LEN_RFC2133)
 141                 return -EINVAL;
 142
 143         if (usin->sin6_family != AF_INET6)
 144                 return -EAFNOSUPPORT;
 145
 146         memset(&fl6, 0, sizeof(fl6));
 147
 148         if (np->sndflow) {
 149                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 150                 IP6_ECN_flow_init(fl6.flowlabel);
 151                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 152                         struct ip6_flowlabel *flowlabel;
 153                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 154                         if (flowlabel == NULL)
 155                                 return -EINVAL;
 156                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
 157                         fl6_sock_release(flowlabel);
 158                 }
 159         }
 160
 161         /*
 162          *      connect() to INADDR_ANY means loopback (BSD'ism).
 163          */
 164
 165         if(ipv6_addr_any(&usin->sin6_addr))
 166                 usin->sin6_addr.s6_addr[15] = 0x1;
 167
 168         addr_type = ipv6_addr_type(&usin->sin6_addr);
 169
 170         if(addr_type & IPV6_ADDR_MULTICAST)
 171                 return -ENETUNREACH;
 172
 173         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 174                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 175                     usin->sin6_scope_id) {
 176                         /* If interface is set while binding, indices
 177                          * must coincide.
 178                          */
 179                         if (sk->sk_bound_dev_if &&
 180                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 181                                 return -EINVAL;
 182
 183                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 184                 }
 185
 186                 /* Connect to link-local address requires an interface */
 187                 if (!sk->sk_bound_dev_if)
 188                         return -EINVAL;
 189         }
 190
 191         if (tp->rx_opt.ts_recent_stamp &&
 192             !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
 193                 tp->rx_opt.ts_recent = 0;
 194                 tp->rx_opt.ts_recent_stamp = 0;
 195                 tp->write_seq = 0;
 196         }
 197
 198         ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
 199         np->flow_label = fl6.flowlabel;
 200
 201         /*
 202          *      TCP over IPv4
 203          */
 204
 205         if (addr_type == IPV6_ADDR_MAPPED) {
 206                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 207                 struct sockaddr_in sin;
 208
 209                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 210
 211                 if (__ipv6_only_sock(sk))
 212                         return -ENETUNREACH;
 213
 214                 sin.sin_family = AF_INET;
 215                 sin.sin_port = usin->sin6_port;
 216                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 217
 218                 icsk->icsk_af_ops = &ipv6_mapped;
 219                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 220 #ifdef CONFIG_TCP_MD5SIG
 221                 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 222 #endif
 223
 224                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 225
 226                 if (err) {
 227                         icsk->icsk_ext_hdr_len = exthdrlen;
 228                         icsk->icsk_af_ops = &ipv6_specific;
 229                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
 230 #ifdef CONFIG_TCP_MD5SIG
 231                         tp->af_specific = &tcp_sock_ipv6_specific;
 232 #endif
 233                         goto failure;
 234                 } else {
 235                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 236                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 237                                                &np->rcv_saddr);
 238                 }
 239
 240                 return err;
 241         }
 242
 243         if (!ipv6_addr_any(&np->rcv_saddr))
 244                 saddr = &np->rcv_saddr;
 245
 246         fl6.flowi6_proto = IPPROTO_TCP;
 247         ipv6_addr_copy(&fl6.daddr, &np->daddr);
 248         ipv6_addr_copy(&fl6.saddr,
 249                        (saddr ? saddr : &np->saddr));
 250         fl6.flowi6_oif = sk->sk_bound_dev_if;
 251         fl6.flowi6_mark = sk->sk_mark;
 252         fl6.fl6_dport = usin->sin6_port;
 253         fl6.fl6_sport = inet->inet_sport;
 254
 255         final_p = fl6_update_dst(&fl6, np->opt, &final);
 256
 257         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 258
 259         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 260         if (IS_ERR(dst)) {
 261                 err = PTR_ERR(dst);
 262                 goto failure;
 263         }
 264
 265         if (saddr == NULL) {
 266                 saddr = &fl6.saddr;
 267                 ipv6_addr_copy(&np->rcv_saddr, saddr);
 268         }
 269
 270         /* set the source address */
 271         ipv6_addr_copy(&np->saddr, saddr);
 272         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 273
 274         sk->sk_gso_type = SKB_GSO_TCPV6;
 275         __ip6_dst_store(sk, dst, NULL, NULL);
 276
 277         rt = (struct rt6_info *) dst;
 278         if (tcp_death_row.sysctl_tw_recycle &&
 279             !tp->rx_opt.ts_recent_stamp &&
 280             ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
 281                 struct inet_peer *peer = rt6_get_peer(rt);
 282                 /*
 283                  * VJ's idea. We save last timestamp seen from
 284                  * the destination in peer table, when entering state
 285                  * TIME-WAIT * and initialize rx_opt.ts_recent from it,
 286                  * when trying new connection.
 287                  */
 288                 if (peer) {
 289                         inet_peer_refcheck(peer);
 290                         if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
 291                                 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
 292                                 tp->rx_opt.ts_recent = peer->tcp_ts;
 293                         }
 294                 }
 295         }
 296
 297         icsk->icsk_ext_hdr_len = 0;
 298         if (np->opt)
 299                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 300                                           np->opt->opt_nflen);
 301
 302         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 303
 304         inet->inet_dport = usin->sin6_port;
 305
 306         tcp_set_state(sk, TCP_SYN_SENT);
 307         err = inet6_hash_connect(&tcp_death_row, sk);
 308         if (err)
 309                 goto late_failure;
 310
 311         if (!tp->write_seq)
 312                 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
 313                                                              np->daddr.s6_addr32,
 314                                                              inet->inet_sport,
 315                                                              inet->inet_dport);
 316
 317         err = tcp_connect(sk);
 318         if (err)
 319                 goto late_failure;
 320
 321         return 0;
 322
 323 late_failure:
 324         tcp_set_state(sk, TCP_CLOSE);
 325         __sk_dst_reset(sk);
 326 failure:
 327         inet->inet_dport = 0;
 328         sk->sk_route_caps = 0;
 329         return err;
 330 }
 331
 332 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 333                 u8 type, u8 code, int offset, __be32 info)
 334 {
 335         const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
 336         const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 337         struct ipv6_pinfo *np;
 338         struct sock *sk;
 339         int err;
 340         struct tcp_sock *tp;
 341         __u32 seq;
 342         struct net *net = dev_net(skb->dev);
 343
 344         sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
 345                         th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
 346
 347         if (sk == NULL) {
 348                 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 349                                    ICMP6_MIB_INERRORS);
 350                 return;
 351         }
 352
 353         if (sk->sk_state == TCP_TIME_WAIT) {
 354                 inet_twsk_put(inet_twsk(sk));
 355                 return;
 356         }
 357
 358         bh_lock_sock(sk);
 359         if (sock_owned_by_user(sk))
 360                 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
 361
 362         if (sk->sk_state == TCP_CLOSE)
 363                 goto out;
 364
 365         if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
 366                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
 367                 goto out;
 368         }
 369
 370         tp = tcp_sk(sk);
 371         seq = ntohl(th->seq);
 372         if (sk->sk_state != TCP_LISTEN &&
 373             !between(seq, tp->snd_una, tp->snd_nxt)) {
 374                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 375                 goto out;
 376         }
 377
 378         np = inet6_sk(sk);
 379
 380         if (type == ICMPV6_PKT_TOOBIG) {
 381                 struct dst_entry *dst;
 382
 383                 if (sock_owned_by_user(sk))
 384                         goto out;
 385                 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 386                         goto out;
 387
 388                 /* icmp should have updated the destination cache entry */
 389                 dst = __sk_dst_check(sk, np->dst_cookie);
 390
 391                 if (dst == NULL) {
 392                         struct inet_sock *inet = inet_sk(sk);
 393                         struct flowi6 fl6;
 394
 395                         /* BUGGG_FUTURE: Again, it is not clear how
 396                            to handle rthdr case. Ignore this complexity
 397                            for now.
 398                          */
 399                         memset(&fl6, 0, sizeof(fl6));
 400                         fl6.flowi6_proto = IPPROTO_TCP;
 401                         ipv6_addr_copy(&fl6.daddr, &np->daddr);
 402                         ipv6_addr_copy(&fl6.saddr, &np->saddr);
 403                         fl6.flowi6_oif = sk->sk_bound_dev_if;
 404                         fl6.flowi6_mark = sk->sk_mark;
 405                         fl6.fl6_dport = inet->inet_dport;
 406                         fl6.fl6_sport = inet->inet_sport;
 407                         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 408
 409                         dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
 410                         if (IS_ERR(dst)) {
 411                                 sk->sk_err_soft = -PTR_ERR(dst);
 412                                 goto out;
 413                         }
 414
 415                 } else
 416                         dst_hold(dst);
 417
 418                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 419                         tcp_sync_mss(sk, dst_mtu(dst));
 420                         tcp_simple_retransmit(sk);
 421                 } /* else let the usual retransmit timer handle it */
 422                 dst_release(dst);
 423                 goto out;
 424         }
 425
 426         icmpv6_err_convert(type, code, &err);
 427
 428         /* Might be for an request_sock */
 429         switch (sk->sk_state) {
 430                 struct request_sock *req, **prev;
 431         case TCP_LISTEN:
 432                 if (sock_owned_by_user(sk))
 433                         goto out;
 434
 435                 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
 436                                            &hdr->saddr, inet6_iif(skb));
 437                 if (!req)
 438                         goto out;
 439
 440                 /* ICMPs are not backlogged, hence we cannot get
 441                  * an established socket here.
 442                  */
 443                 WARN_ON(req->sk != NULL);
 444
 445                 if (seq != tcp_rsk(req)->snt_isn) {
 446                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 447                         goto out;
 448                 }
 449
 450                 inet_csk_reqsk_queue_drop(sk, req, prev);
 451                 goto out;
 452
 453         case TCP_SYN_SENT:
 454         case TCP_SYN_RECV:  /* Cannot happen.
 455                                It can, it SYNs are crossed. --ANK */
 456                 if (!sock_owned_by_user(sk)) {
 457                         sk->sk_err = err;
 458                         sk->sk_error_report(sk);                /* Wake people up to see the error (see connect in sock.c) */
 459
 460                         tcp_done(sk);
 461                 } else
 462                         sk->sk_err_soft = err;
 463                 goto out;
 464         }
 465
 466         if (!sock_owned_by_user(sk) && np->recverr) {
 467                 sk->sk_err = err;
 468                 sk->sk_error_report(sk);
 469         } else
 470                 sk->sk_err_soft = err;
 471
 472 out:
 473         bh_unlock_sock(sk);
 474         sock_put(sk);
 475 }
 476
 477
 478 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
 479                               struct request_values *rvp)
 480 {
 481         struct inet6_request_sock *treq = inet6_rsk(req);
 482         struct ipv6_pinfo *np = inet6_sk(sk);
 483         struct sk_buff * skb;
 484         struct ipv6_txoptions *opt = NULL;
 485         struct in6_addr * final_p, final;
 486         struct flowi6 fl6;
 487         struct dst_entry *dst;
 488         int err;
 489
 490         memset(&fl6, 0, sizeof(fl6));
 491         fl6.flowi6_proto = IPPROTO_TCP;
 492         ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
 493         ipv6_addr_copy(&fl6.saddr, &treq->loc_addr);
 494         fl6.flowlabel = 0;
 495         fl6.flowi6_oif = treq->iif;
 496         fl6.flowi6_mark = sk->sk_mark;
 497         fl6.fl6_dport = inet_rsk(req)->rmt_port;
 498         fl6.fl6_sport = inet_rsk(req)->loc_port;
 499         security_req_classify_flow(req, flowi6_to_flowi(&fl6));
 500
 501         opt = np->opt;
 502         final_p = fl6_update_dst(&fl6, opt, &final);
 503
 504         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
 505         if (IS_ERR(dst)) {
 506                 err = PTR_ERR(dst);
 507                 dst = NULL;
 508                 goto done;
 509         }
 510         skb = tcp_make_synack(sk, dst, req, rvp);
 511         err = -ENOMEM;
 512         if (skb) {
 513                 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
 514
 515                 ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
 516                 err = ip6_xmit(sk, skb, &fl6, opt);
 517                 err = net_xmit_eval(err);
 518         }
 519
 520 done:
 521         if (opt && opt != np->opt)
 522                 sock_kfree_s(sk, opt, opt->tot_len);
 523         dst_release(dst);
 524         return err;
 525 }
 526
 527 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
 528                              struct request_values *rvp)
 529 {
 530         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
 531         return tcp_v6_send_synack(sk, req, rvp);
 532 }
 533
 534 static void tcp_v6_reqsk_destructor(struct request_sock *req)
 535 {
 536         kfree_skb(inet6_rsk(req)->pktopts);
 537 }
 538
 539 #ifdef CONFIG_TCP_MD5SIG
 540 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 541                                                    const struct in6_addr *addr)
 542 {
 543         struct tcp_sock *tp = tcp_sk(sk);
 544         int i;
 545
 546         BUG_ON(tp == NULL);
 547
 548         if (!tp->md5sig_info || !tp->md5sig_info->entries6)
 549                 return NULL;
 550
 551         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 552                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
 553                         return &tp->md5sig_info->keys6[i].base;
 554         }
 555         return NULL;
 556 }
 557
 558 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
 559                                                 struct sock *addr_sk)
 560 {
 561         return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
 562 }
 563
 564 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
 565                                                       struct request_sock *req)
 566 {
 567         return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
 568 }
 569
 570 static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer,
 571                              char *newkey, u8 newkeylen)
 572 {
 573         /* Add key to the list */
 574         struct tcp_md5sig_key *key;
 575         struct tcp_sock *tp = tcp_sk(sk);
 576         struct tcp6_md5sig_key *keys;
 577
 578         key = tcp_v6_md5_do_lookup(sk, peer);
 579         if (key) {
 580                 /* modify existing entry - just update that one */
 581                 kfree(key->key);
 582                 key->key = newkey;
 583                 key->keylen = newkeylen;
 584         } else {
 585                 /* reallocate new list if current one is full. */
 586                 if (!tp->md5sig_info) {
 587                         tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
 588                         if (!tp->md5sig_info) {
 589                                 kfree(newkey);
 590                                 return -ENOMEM;
 591                         }
 592                         sk_nocaps_add(sk, NETIF_F_GSO_MASK);
 593                 }
 594                 if (tp->md5sig_info->entries6 == 0 &&
 595                         tcp_alloc_md5sig_pool(sk) == NULL) {
 596                         kfree(newkey);
 597                         return -ENOMEM;
 598                 }
 599                 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
 600                         keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
 601                                        (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 602
 603                         if (!keys) {
 604                                 kfree(newkey);
 605                                 if (tp->md5sig_info->entries6 == 0)
 606                                         tcp_free_md5sig_pool();
 607                                 return -ENOMEM;
 608                         }
 609
 610                         if (tp->md5sig_info->entries6)
 611                                 memmove(keys, tp->md5sig_info->keys6,
 612                                         (sizeof (tp->md5sig_info->keys6[0]) *
 613                                          tp->md5sig_info->entries6));
 614
 615                         kfree(tp->md5sig_info->keys6);
 616                         tp->md5sig_info->keys6 = keys;
 617                         tp->md5sig_info->alloced6++;
 618                 }
 619
 620                 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
 621                                peer);
 622                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
 623                 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
 624
 625                 tp->md5sig_info->entries6++;
 626         }
 627         return 0;
 628 }
 629
 630 static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
 631                                u8 *newkey, __u8 newkeylen)
 632 {
 633         return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
 634                                  newkey, newkeylen);
 635 }
 636
 637 static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer)
 638 {
 639         struct tcp_sock *tp = tcp_sk(sk);
 640         int i;
 641
 642         for (i = 0; i < tp->md5sig_info->entries6; i++) {
 643                 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
 644                         /* Free the key */
 645                         kfree(tp->md5sig_info->keys6[i].base.key);
 646                         tp->md5sig_info->entries6--;
 647
 648                         if (tp->md5sig_info->entries6 == 0) {
 649                                 kfree(tp->md5sig_info->keys6);
 650                                 tp->md5sig_info->keys6 = NULL;
 651                                 tp->md5sig_info->alloced6 = 0;
 652                                 tcp_free_md5sig_pool();
 653                         } else {
 654                                 /* shrink the database */
 655                                 if (tp->md5sig_info->entries6 != i)
 656                                         memmove(&tp->md5sig_info->keys6[i],
 657                                                 &tp->md5sig_info->keys6[i+1],
 658                                                 (tp->md5sig_info->entries6 - i)
 659                                                 * sizeof (tp->md5sig_info->keys6[0]));
 660                         }
 661                         return 0;
 662                 }
 663         }
 664         return -ENOENT;
 665 }
 666
 667 static void tcp_v6_clear_md5_list (struct sock *sk)
 668 {
 669         struct tcp_sock *tp = tcp_sk(sk);
 670         int i;
 671
 672         if (tp->md5sig_info->entries6) {
 673                 for (i = 0; i < tp->md5sig_info->entries6; i++)
 674                         kfree(tp->md5sig_info->keys6[i].base.key);
 675                 tp->md5sig_info->entries6 = 0;
 676                 tcp_free_md5sig_pool();
 677         }
 678
 679         kfree(tp->md5sig_info->keys6);
 680         tp->md5sig_info->keys6 = NULL;
 681         tp->md5sig_info->alloced6 = 0;
 682
 683         if (tp->md5sig_info->entries4) {
 684                 for (i = 0; i < tp->md5sig_info->entries4; i++)
 685                         kfree(tp->md5sig_info->keys4[i].base.key);
 686                 tp->md5sig_info->entries4 = 0;
 687                 tcp_free_md5sig_pool();
 688         }
 689
 690         kfree(tp->md5sig_info->keys4);
 691         tp->md5sig_info->keys4 = NULL;
 692         tp->md5sig_info->alloced4 = 0;
 693 }
 694
 695 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
 696                                   int optlen)
 697 {
 698         struct tcp_md5sig cmd;
 699         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 700         u8 *newkey;
 701
 702         if (optlen < sizeof(cmd))
 703                 return -EINVAL;
 704
 705         if (copy_from_user(&cmd, optval, sizeof(cmd)))
 706                 return -EFAULT;
 707
 708         if (sin6->sin6_family != AF_INET6)
 709                 return -EINVAL;
 710
 711         if (!cmd.tcpm_keylen) {
 712                 if (!tcp_sk(sk)->md5sig_info)
 713                         return -ENOENT;
 714                 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 715                         return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
 716                 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
 717         }
 718
 719         if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 720                 return -EINVAL;
 721
 722         if (!tcp_sk(sk)->md5sig_info) {
 723                 struct tcp_sock *tp = tcp_sk(sk);
 724                 struct tcp_md5sig_info *p;
 725
 726                 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
 727                 if (!p)
 728                         return -ENOMEM;
 729
 730                 tp->md5sig_info = p;
 731                 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
 732         }
 733
 734         newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
 735         if (!newkey)
 736                 return -ENOMEM;
 737         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 738                 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
 739                                          newkey, cmd.tcpm_keylen);
 740         }
 741         return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
 742 }
 743
 744 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
 745                                         const struct in6_addr *daddr,
 746                                         const struct in6_addr *saddr, int nbytes)
 747 {
 748         struct tcp6_pseudohdr *bp;
 749         struct scatterlist sg;
 750
 751         bp = &hp->md5_blk.ip6;
 752         /* 1. TCP pseudo-header (RFC2460) */
 753         ipv6_addr_copy(&bp->saddr, saddr);
 754         ipv6_addr_copy(&bp->daddr, daddr);
 755         bp->protocol = cpu_to_be32(IPPROTO_TCP);
 756         bp->len = cpu_to_be32(nbytes);
 757
 758         sg_init_one(&sg, bp, sizeof(*bp));
 759         return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
 760 }
 761
 762 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
 763                                const struct in6_addr *daddr, struct in6_addr *saddr,
 764                                const struct tcphdr *th)
 765 {
 766         struct tcp_md5sig_pool *hp;
 767         struct hash_desc *desc;
 768
 769         hp = tcp_get_md5sig_pool();
 770         if (!hp)
 771                 goto clear_hash_noput;
 772         desc = &hp->md5_desc;
 773
 774         if (crypto_hash_init(desc))
 775                 goto clear_hash;
 776         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
 777                 goto clear_hash;
 778         if (tcp_md5_hash_header(hp, th))
 779                 goto clear_hash;
 780         if (tcp_md5_hash_key(hp, key))
 781                 goto clear_hash;
 782         if (crypto_hash_final(desc, md5_hash))
 783                 goto clear_hash;
 784
 785         tcp_put_md5sig_pool();
 786         return 0;
 787
 788 clear_hash:
 789         tcp_put_md5sig_pool();
 790 clear_hash_noput:
 791         memset(md5_hash, 0, 16);
 792         return 1;
 793 }
 794
 795 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 796                                const struct sock *sk,
 797                                const struct request_sock *req,
 798                                const struct sk_buff *skb)
 799 {
 800         const struct in6_addr *saddr, *daddr;
 801         struct tcp_md5sig_pool *hp;
 802         struct hash_desc *desc;
 803         const struct tcphdr *th = tcp_hdr(skb);
 804
 805         if (sk) {
 806                 saddr = &inet6_sk(sk)->saddr;
 807                 daddr = &inet6_sk(sk)->daddr;
 808         } else if (req) {
 809                 saddr = &inet6_rsk(req)->loc_addr;
 810                 daddr = &inet6_rsk(req)->rmt_addr;
 811         } else {
 812                 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 813                 saddr = &ip6h->saddr;
 814                 daddr = &ip6h->daddr;
 815         }
 816
 817         hp = tcp_get_md5sig_pool();
 818         if (!hp)
 819                 goto clear_hash_noput;
 820         desc = &hp->md5_desc;
 821
 822         if (crypto_hash_init(desc))
 823                 goto clear_hash;
 824
 825         if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
 826                 goto clear_hash;
 827         if (tcp_md5_hash_header(hp, th))
 828                 goto clear_hash;
 829         if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
 830                 goto clear_hash;
 831         if (tcp_md5_hash_key(hp, key))
 832                 goto clear_hash;
 833         if (crypto_hash_final(desc, md5_hash))
 834                 goto clear_hash;
 835
 836         tcp_put_md5sig_pool();
 837         return 0;
 838
 839 clear_hash:
 840         tcp_put_md5sig_pool();
 841 clear_hash_noput:
 842         memset(md5_hash, 0, 16);
 843         return 1;
 844 }
 845
 846 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 847 {
 848         const __u8 *hash_location = NULL;
 849         struct tcp_md5sig_key *hash_expected;
 850         const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 851         const struct tcphdr *th = tcp_hdr(skb);
 852         int genhash;
 853         u8 newhash[16];
 854
 855         hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
 856         hash_location = tcp_parse_md5sig_option(th);
 857
 858         /* We've parsed the options - do we have a hash? */
 859         if (!hash_expected && !hash_location)
 860                 return 0;
 861
 862         if (hash_expected && !hash_location) {
 863                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 864                 return 1;
 865         }
 866
 867         if (!hash_expected && hash_location) {
 868                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 869                 return 1;
 870         }
 871
 872         /* check the signature */
 873         genhash = tcp_v6_md5_hash_skb(newhash,
 874                                       hash_expected,
 875                                       NULL, NULL, skb);
 876
 877         if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 878                 if (net_ratelimit()) {
 879                         printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 880                                genhash ? "failed" : "mismatch",
 881                                &ip6h->saddr, ntohs(th->source),
 882                                &ip6h->daddr, ntohs(th->dest));
 883                 }
 884                 return 1;
 885         }
 886         return 0;
 887 }
 888 #endif
 889
 890 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 891         .family         =       AF_INET6,
 892         .obj_size       =       sizeof(struct tcp6_request_sock),
 893         .rtx_syn_ack    =       tcp_v6_rtx_synack,
 894         .send_ack       =       tcp_v6_reqsk_send_ack,
 895         .destructor     =       tcp_v6_reqsk_destructor,
 896         .send_reset     =       tcp_v6_send_reset,
 897         .syn_ack_timeout =      tcp_syn_ack_timeout,
 898 };
 899
 900 #ifdef CONFIG_TCP_MD5SIG
 901 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 902         .md5_lookup     =       tcp_v6_reqsk_md5_lookup,
 903         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
 904 };
 905 #endif
 906
 907 static void __tcp_v6_send_check(struct sk_buff *skb,
 908                                 const struct in6_addr *saddr, const struct in6_addr *daddr)
 909 {
 910         struct tcphdr *th = tcp_hdr(skb);
 911
 912         if (skb->ip_summed == CHECKSUM_PARTIAL) {
 913                 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
 914                 skb->csum_start = skb_transport_header(skb) - skb->head;
 915                 skb->csum_offset = offsetof(struct tcphdr, check);
 916         } else {
 917                 th->check = tcp_v6_check(skb->len, saddr, daddr,
 918                                          csum_partial(th, th->doff << 2,
 919                                                       skb->csum));
 920         }
 921 }
 922
 923 static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
 924 {
 925         struct ipv6_pinfo *np = inet6_sk(sk);
 926
 927         __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
 928 }
 929
 930 static int tcp_v6_gso_send_check(struct sk_buff *skb)
 931 {
 932         const struct ipv6hdr *ipv6h;
 933         struct tcphdr *th;
 934
 935         if (!pskb_may_pull(skb, sizeof(*th)))
 936                 return -EINVAL;
 937
 938         ipv6h = ipv6_hdr(skb);
 939         th = tcp_hdr(skb);
 940
 941         th->check = 0;
 942         skb->ip_summed = CHECKSUM_PARTIAL;
 943         __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
 944         return 0;
 945 }
 946
 947 static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
 948                                          struct sk_buff *skb)
 949 {
 950         const struct ipv6hdr *iph = skb_gro_network_header(skb);
 951
 952         switch (skb->ip_summed) {
 953         case CHECKSUM_COMPLETE:
 954                 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
 955                                   skb->csum)) {
 956                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 957                         break;
 958                 }
 959
 960                 /* fall through */
 961         case CHECKSUM_NONE:
 962                 NAPI_GRO_CB(skb)->flush = 1;
 963                 return NULL;
 964         }
 965
 966         return tcp_gro_receive(head, skb);
 967 }
 968
 969 static int tcp6_gro_complete(struct sk_buff *skb)
 970 {
 971         const struct ipv6hdr *iph = ipv6_hdr(skb);
 972         struct tcphdr *th = tcp_hdr(skb);
 973
 974         th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
 975                                   &iph->saddr, &iph->daddr, 0);
 976         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 977
 978         return tcp_gro_complete(skb);
 979 }
 980
 981 static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
 982                                  u32 ts, struct tcp_md5sig_key *key, int rst)
 983 {
 984         const struct tcphdr *th = tcp_hdr(skb);
 985         struct tcphdr *t1;
 986         struct sk_buff *buff;
 987         struct flowi6 fl6;
 988         struct net *net = dev_net(skb_dst(skb)->dev);
 989         struct sock *ctl_sk = net->ipv6.tcp_sk;
 990         unsigned int tot_len = sizeof(struct tcphdr);
 991         struct dst_entry *dst;
 992         __be32 *topt;
 993
 994         if (ts)
 995                 tot_len += TCPOLEN_TSTAMP_ALIGNED;
 996 #ifdef CONFIG_TCP_MD5SIG
 997         if (key)
 998                 tot_len += TCPOLEN_MD5SIG_ALIGNED;
 999 #endif
1000
1001         buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1002                          GFP_ATOMIC);
1003         if (buff == NULL)
1004                 return;
1005
1006         skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1007
1008         t1 = (struct tcphdr *) skb_push(buff, tot_len);
1009         skb_reset_transport_header(buff);
1010
1011         /* Swap the send and the receive. */
1012         memset(t1, 0, sizeof(*t1));
1013         t1->dest = th->source;
1014         t1->source = th->dest;
1015         t1->doff = tot_len / 4;
1016         t1->seq = htonl(seq);
1017         t1->ack_seq = htonl(ack);
1018         t1->ack = !rst || !th->ack;
1019         t1->rst = rst;
1020         t1->window = htons(win);
1021
1022         topt = (__be32 *)(t1 + 1);
1023
1024         if (ts) {
1025                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1026                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1027                 *topt++ = htonl(tcp_time_stamp);
1028                 *topt++ = htonl(ts);
1029         }
1030
1031 #ifdef CONFIG_TCP_MD5SIG
1032         if (key) {
1033                 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1034                                 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1035                 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1036                                     &ipv6_hdr(skb)->saddr,
1037                                     &ipv6_hdr(skb)->daddr, t1);
1038         }
1039 #endif
1040
1041         memset(&fl6, 0, sizeof(fl6));
1042         ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
1043         ipv6_addr_copy(&fl6.saddr, &ipv6_hdr(skb)->daddr);
1044
1045         buff->ip_summed = CHECKSUM_PARTIAL;
1046         buff->csum = 0;
1047
1048         __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
1049
1050         fl6.flowi6_proto = IPPROTO_TCP;
1051         fl6.flowi6_oif = inet6_iif(skb);
1052         fl6.fl6_dport = t1->dest;
1053         fl6.fl6_sport = t1->source;
1054         security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
1055
1056         /* Pass a socket to ip6_dst_lookup either it is for RST
1057          * Underlying function will use this to retrieve the network
1058          * namespace
1059          */
1060         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
1061         if (!IS_ERR(dst)) {
1062                 skb_dst_set(buff, dst);
1063                 ip6_xmit(ctl_sk, buff, &fl6, NULL);
1064                 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1065                 if (rst)
1066                         TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1067                 return;
1068         }
1069
1070         kfree_skb(buff);
1071 }
1072
1073 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1074 {
1075         const struct tcphdr *th = tcp_hdr(skb);
1076         u32 seq = 0, ack_seq = 0;
1077         struct tcp_md5sig_key *key = NULL;
1078
1079         if (th->rst)
1080                 return;
1081
1082         if (!ipv6_unicast_destination(skb))
1083                 return;
1084
1085 #ifdef CONFIG_TCP_MD5SIG
1086         if (sk)
1087                 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1088 #endif
1089
1090         if (th->ack)
1091                 seq = ntohl(th->ack_seq);
1092         else
1093                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1094                           (th->doff << 2);
1095
1096         tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1097 }
1098
1099 static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1100                             struct tcp_md5sig_key *key)
1101 {
1102         tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1103 }
1104
1105 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1106 {
1107         struct inet_timewait_sock *tw = inet_twsk(sk);
1108         struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1109
1110         tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1111                         tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1112                         tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1113
1114         inet_twsk_put(tw);
1115 }
1116
1117 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1118                                   struct request_sock *req)
1119 {
1120         tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1121                         tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1122 }
1123
1124
1125 static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1126 {
1127         struct request_sock *req, **prev;
1128         const struct tcphdr *th = tcp_hdr(skb);
1129         struct sock *nsk;
1130
1131         /* Find possible connection requests. */
1132         req = inet6_csk_search_req(sk, &prev, th->source,
1133                                    &ipv6_hdr(skb)->saddr,
1134                                    &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1135         if (req)
1136                 return tcp_check_req(sk, skb, req, prev);
1137
1138         nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1139                         &ipv6_hdr(skb)->saddr, th->source,
1140                         &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1141
1142         if (nsk) {
1143                 if (nsk->sk_state != TCP_TIME_WAIT) {
1144                         bh_lock_sock(nsk);
1145                         return nsk;
1146                 }
1147                 inet_twsk_put(inet_twsk(nsk));
1148                 return NULL;
1149         }
1150
1151 #ifdef CONFIG_SYN_COOKIES
1152         if (!th->syn)
1153                 sk = cookie_v6_check(sk, skb);
1154 #endif
1155         return sk;
1156 }
1157
1158 /* FIXME: this is substantially similar to the ipv4 code.
1159  * Can some kind of merge be done? -- erics
1160  */
1161 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1162 {
1163         struct tcp_extend_values tmp_ext;
1164         struct tcp_options_received tmp_opt;
1165         const u8 *hash_location;
1166         struct request_sock *req;
1167         struct inet6_request_sock *treq;
1168         struct ipv6_pinfo *np = inet6_sk(sk);
1169         struct tcp_sock *tp = tcp_sk(sk);
1170         __u32 isn = TCP_SKB_CB(skb)->when;
1171         struct dst_entry *dst = NULL;
1172         int want_cookie = 0;
1173
1174         if (skb->protocol == htons(ETH_P_IP))
1175                 return tcp_v4_conn_request(sk, skb);
1176
1177         if (!ipv6_unicast_destination(skb))
1178                 goto drop;
1179
1180         if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1181                 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
1182                 if (!want_cookie)
1183                         goto drop;
1184         }
1185
1186         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1187                 goto drop;
1188
1189         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1190         if (req == NULL)
1191                 goto drop;
1192
1193 #ifdef CONFIG_TCP_MD5SIG
1194         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1195 #endif
1196
1197         tcp_clear_options(&tmp_opt);
1198         tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1199         tmp_opt.user_mss = tp->rx_opt.user_mss;
1200         tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1201
1202         if (tmp_opt.cookie_plus > 0 &&
1203             tmp_opt.saw_tstamp &&
1204             !tp->rx_opt.cookie_out_never &&
1205             (sysctl_tcp_cookie_size > 0 ||
1206              (tp->cookie_values != NULL &&
1207               tp->cookie_values->cookie_desired > 0))) {
1208                 u8 *c;
1209                 u32 *d;
1210                 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1211                 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1212
1213                 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1214                         goto drop_and_free;
1215
1216                 /* Secret recipe starts with IP addresses */
1217                 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1218                 *mess++ ^= *d++;
1219                 *mess++ ^= *d++;
1220                 *mess++ ^= *d++;
1221                 *mess++ ^= *d++;
1222                 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1223                 *mess++ ^= *d++;
1224                 *mess++ ^= *d++;
1225                 *mess++ ^= *d++;
1226                 *mess++ ^= *d++;
1227
1228                 /* plus variable length Initiator Cookie */
1229                 c = (u8 *)mess;
1230                 while (l-- > 0)
1231                         *c++ ^= *hash_location++;
1232
1233                 want_cookie = 0;        /* not our kind of cookie */
1234                 tmp_ext.cookie_out_never = 0; /* false */
1235                 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1236         } else if (!tp->rx_opt.cookie_in_always) {
1237                 /* redundant indications, but ensure initialization. */
1238                 tmp_ext.cookie_out_never = 1; /* true */
1239                 tmp_ext.cookie_plus = 0;
1240         } else {
1241                 goto drop_and_free;
1242         }
1243         tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1244
1245         if (want_cookie && !tmp_opt.saw_tstamp)
1246                 tcp_clear_options(&tmp_opt);
1247
1248         tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1249         tcp_openreq_init(req, &tmp_opt, skb);
1250
1251         treq = inet6_rsk(req);
1252         ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1253         ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1254         if (!want_cookie || tmp_opt.tstamp_ok)
1255                 TCP_ECN_create_request(req, tcp_hdr(skb));
1256
1257         if (!isn) {
1258                 struct inet_peer *peer = NULL;
1259
1260                 if (ipv6_opt_accepted(sk, skb) ||
1261                     np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1262                     np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1263                         atomic_inc(&skb->users);
1264                         treq->pktopts = skb;
1265                 }
1266                 treq->iif = sk->sk_bound_dev_if;
1267
1268                 /* So that link locals have meaning */
1269                 if (!sk->sk_bound_dev_if &&
1270                     ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1271                         treq->iif = inet6_iif(skb);
1272
1273                 if (want_cookie) {
1274                         isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1275                         req->cookie_ts = tmp_opt.tstamp_ok;
1276                         goto have_isn;
1277                 }
1278
1279                 /* VJ's idea. We save last timestamp seen
1280                  * from the destination in peer table, when entering
1281                  * state TIME-WAIT, and check against it before
1282                  * accepting new connection request.
1283                  *
1284                  * If "isn" is not zero, this request hit alive
1285                  * timewait bucket, so that all the necessary checks
1286                  * are made in the function processing timewait state.
1287                  */
1288                 if (tmp_opt.saw_tstamp &&
1289                     tcp_death_row.sysctl_tw_recycle &&
1290                     (dst = inet6_csk_route_req(sk, req)) != NULL &&
1291                     (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1292                     ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1293                                     &treq->rmt_addr)) {
1294                         inet_peer_refcheck(peer);
1295                         if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1296                             (s32)(peer->tcp_ts - req->ts_recent) >
1297                                                         TCP_PAWS_WINDOW) {
1298                                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1299                                 goto drop_and_release;
1300                         }
1301                 }
1302                 /* Kill the following clause, if you dislike this way. */
1303                 else if (!sysctl_tcp_syncookies &&
1304                          (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1305                           (sysctl_max_syn_backlog >> 2)) &&
1306                          (!peer || !peer->tcp_ts_stamp) &&
1307                          (!dst || !dst_metric(dst, RTAX_RTT))) {
1308                         /* Without syncookies last quarter of
1309                          * backlog is filled with destinations,
1310                          * proven to be alive.
1311                          * It means that we continue to communicate
1312                          * to destinations, already remembered
1313                          * to the moment of synflood.
1314                          */
1315                         LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1316                                        &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1317                         goto drop_and_release;
1318                 }
1319
1320                 isn = tcp_v6_init_sequence(skb);
1321         }
1322 have_isn:
1323         tcp_rsk(req)->snt_isn = isn;
1324         tcp_rsk(req)->snt_synack = tcp_time_stamp;
1325
1326         security_inet_conn_request(sk, skb, req);
1327
1328         if (tcp_v6_send_synack(sk, req,
1329                                (struct request_values *)&tmp_ext) ||
1330             want_cookie)
1331                 goto drop_and_free;
1332
1333         inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1334         return 0;
1335
1336 drop_and_release:
1337         dst_release(dst);
1338 drop_and_free:
1339         reqsk_free(req);
1340 drop:
1341         return 0; /* don't send reset */
1342 }
1343
1344 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1345                                           struct request_sock *req,
1346                                           struct dst_entry *dst)
1347 {
1348         struct inet6_request_sock *treq;
1349         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1350         struct tcp6_sock *newtcp6sk;
1351         struct inet_sock *newinet;
1352         struct tcp_sock *newtp;
1353         struct sock *newsk;
1354         struct ipv6_txoptions *opt;
1355 #ifdef CONFIG_TCP_MD5SIG
1356         struct tcp_md5sig_key *key;
1357 #endif
1358
1359         if (skb->protocol == htons(ETH_P_IP)) {
1360                 /*
1361                  *      v6 mapped
1362                  */
1363
1364                 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1365
1366                 if (newsk == NULL)
1367                         return NULL;
1368
1369                 newtcp6sk = (struct tcp6_sock *)newsk;
1370                 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1371
1372                 newinet = inet_sk(newsk);
1373                 newnp = inet6_sk(newsk);
1374                 newtp = tcp_sk(newsk);
1375
1376                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1377
1378                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1379
1380                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1381
1382                 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1383
1384                 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1385                 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1386 #ifdef CONFIG_TCP_MD5SIG
1387                 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1388 #endif
1389
1390                 newnp->ipv6_ac_list = NULL;
1391                 newnp->ipv6_fl_list = NULL;
1392                 newnp->pktoptions  = NULL;
1393                 newnp->opt         = NULL;
1394                 newnp->mcast_oif   = inet6_iif(skb);
1395                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1396
1397                 /*
1398                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1399                  * here, tcp_create_openreq_child now does this for us, see the comment in
1400                  * that function for the gory details. -acme
1401                  */
1402
1403                 /* It is tricky place. Until this moment IPv4 tcp
1404                    worked with IPv6 icsk.icsk_af_ops.
1405                    Sync it now.
1406                  */
1407                 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1408
1409                 return newsk;
1410         }
1411
1412         treq = inet6_rsk(req);
1413         opt = np->opt;
1414
1415         if (sk_acceptq_is_full(sk))
1416                 goto out_overflow;
1417
1418         if (!dst) {
1419                 dst = inet6_csk_route_req(sk, req);
1420                 if (!dst)
1421                         goto out;
1422         }
1423
1424         newsk = tcp_create_openreq_child(sk, req, skb);
1425         if (newsk == NULL)
1426                 goto out_nonewsk;
1427
1428         /*
1429          * No need to charge this sock to the relevant IPv6 refcnt debug socks
1430          * count here, tcp_create_openreq_child now does this for us, see the
1431          * comment in that function for the gory details. -acme
1432          */
1433
1434         newsk->sk_gso_type = SKB_GSO_TCPV6;
1435         __ip6_dst_store(newsk, dst, NULL, NULL);
1436
1437         newtcp6sk = (struct tcp6_sock *)newsk;
1438         inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1439
1440         newtp = tcp_sk(newsk);
1441         newinet = inet_sk(newsk);
1442         newnp = inet6_sk(newsk);
1443
1444         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1445
1446         ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1447         ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1448         ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1449         newsk->sk_bound_dev_if = treq->iif;
1450
1451         /* Now IPv6 options...
1452
1453            First: no IPv4 options.
1454          */
1455         newinet->inet_opt = NULL;
1456         newnp->ipv6_ac_list = NULL;
1457         newnp->ipv6_fl_list = NULL;
1458
1459         /* Clone RX bits */
1460         newnp->rxopt.all = np->rxopt.all;
1461
1462         /* Clone pktoptions received with SYN */
1463         newnp->pktoptions = NULL;
1464         if (treq->pktopts != NULL) {
1465                 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1466                 kfree_skb(treq->pktopts);
1467                 treq->pktopts = NULL;
1468                 if (newnp->pktoptions)
1469                         skb_set_owner_r(newnp->pktoptions, newsk);
1470         }
1471         newnp->opt        = NULL;
1472         newnp->mcast_oif  = inet6_iif(skb);
1473         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1474
1475         /* Clone native IPv6 options from listening socket (if any)
1476
1477            Yes, keeping reference count would be much more clever,
1478            but we make one more one thing there: reattach optmem
1479            to newsk.
1480          */
1481         if (opt) {
1482                 newnp->opt = ipv6_dup_options(newsk, opt);
1483                 if (opt != np->opt)
1484                         sock_kfree_s(sk, opt, opt->tot_len);
1485         }
1486
1487         inet_csk(newsk)->icsk_ext_hdr_len = 0;
1488         if (newnp->opt)
1489                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1490                                                      newnp->opt->opt_flen);
1491
1492         tcp_mtup_init(newsk);
1493         tcp_sync_mss(newsk, dst_mtu(dst));
1494         newtp->advmss = dst_metric_advmss(dst);
1495         tcp_initialize_rcv_mss(newsk);
1496         if (tcp_rsk(req)->snt_synack)
1497                 tcp_valid_rtt_meas(newsk,
1498                     tcp_time_stamp - tcp_rsk(req)->snt_synack);
1499         newtp->total_retrans = req->retrans;
1500
1501         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1502         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1503
1504 #ifdef CONFIG_TCP_MD5SIG
1505         /* Copy over the MD5 key from the original socket */
1506         if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1507                 /* We're using one, so create a matching key
1508                  * on the newsk structure. If we fail to get
1509                  * memory, then we end up not copying the key
1510                  * across. Shucks.
1511                  */
1512                 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1513                 if (newkey != NULL)
1514                         tcp_v6_md5_do_add(newsk, &newnp->daddr,
1515                                           newkey, key->keylen);
1516         }
1517 #endif
1518
1519         if (__inet_inherit_port(sk, newsk) < 0) {
1520                 sock_put(newsk);
1521                 goto out;
1522         }
1523         __inet6_hash(newsk, NULL);
1524
1525         return newsk;
1526
1527 out_overflow:
1528         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1529 out_nonewsk:
1530         if (opt && opt != np->opt)
1531                 sock_kfree_s(sk, opt, opt->tot_len);
1532         dst_release(dst);
1533 out:
1534         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1535         return NULL;
1536 }
1537
1538 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1539 {
1540         if (skb->ip_summed == CHECKSUM_COMPLETE) {
1541                 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1542                                   &ipv6_hdr(skb)->daddr, skb->csum)) {
1543                         skb->ip_summed = CHECKSUM_UNNECESSARY;
1544                         return 0;
1545                 }
1546         }
1547
1548         skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1549                                               &ipv6_hdr(skb)->saddr,
1550                                               &ipv6_hdr(skb)->daddr, 0));
1551
1552         if (skb->len <= 76) {
1553                 return __skb_checksum_complete(skb);
1554         }
1555         return 0;
1556 }
1557
1558 /* The socket must have it's spinlock held when we get
1559  * here.
1560  *
1561  * We have a potential double-lock case here, so even when
1562  * doing backlog processing we use the BH locking scheme.
1563  * This is because we cannot sleep with the original spinlock
1564  * held.
1565  */
1566 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1567 {
1568         struct ipv6_pinfo *np = inet6_sk(sk);
1569         struct tcp_sock *tp;
1570         struct sk_buff *opt_skb = NULL;
1571
1572         /* Imagine: socket is IPv6. IPv4 packet arrives,
1573            goes to IPv4 receive handler and backlogged.
1574            From backlog it always goes here. Kerboom...
1575            Fortunately, tcp_rcv_established and rcv_established
1576            handle them correctly, but it is not case with
1577            tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1578          */
1579
1580         if (skb->protocol == htons(ETH_P_IP))
1581                 return tcp_v4_do_rcv(sk, skb);
1582
1583 #ifdef CONFIG_TCP_MD5SIG
1584         if (tcp_v6_inbound_md5_hash (sk, skb))
1585                 goto discard;
1586 #endif
1587
1588         if (sk_filter(sk, skb))
1589                 goto discard;
1590
1591         /*
1592          *      socket locking is here for SMP purposes as backlog rcv
1593          *      is currently called with bh processing disabled.
1594          */
1595
1596         /* Do Stevens' IPV6_PKTOPTIONS.
1597
1598            Yes, guys, it is the only place in our code, where we
1599            may make it not affecting IPv4.
1600            The rest of code is protocol independent,
1601            and I do not like idea to uglify IPv4.
1602
1603            Actually, all the idea behind IPV6_PKTOPTIONS
1604            looks not very well thought. For now we latch
1605            options, received in the last packet, enqueued
1606            by tcp. Feel free to propose better solution.
1607                                                --ANK (980728)
1608          */
1609         if (np->rxopt.all)
1610                 opt_skb = skb_clone(skb, GFP_ATOMIC);
1611
1612         if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1613                 sock_rps_save_rxhash(sk, skb);
1614                 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1615                         goto reset;
1616                 if (opt_skb)
1617                         goto ipv6_pktoptions;
1618                 return 0;
1619         }
1620
1621         if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1622                 goto csum_err;
1623
1624         if (sk->sk_state == TCP_LISTEN) {
1625                 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1626                 if (!nsk)
1627                         goto discard;
1628
1629                 /*
1630                  * Queue it on the new socket if the new socket is active,
1631                  * otherwise we just shortcircuit this and continue with
1632                  * the new socket..
1633                  */
1634                 if(nsk != sk) {
1635                         sock_rps_save_rxhash(nsk, skb);
1636                         if (tcp_child_process(sk, nsk, skb))
1637                                 goto reset;
1638                         if (opt_skb)
1639                                 __kfree_skb(opt_skb);
1640                         return 0;
1641                 }
1642         } else
1643                 sock_rps_save_rxhash(sk, skb);
1644
1645         if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1646                 goto reset;
1647         if (opt_skb)
1648                 goto ipv6_pktoptions;
1649         return 0;
1650
1651 reset:
1652         tcp_v6_send_reset(sk, skb);
1653 discard:
1654         if (opt_skb)
1655                 __kfree_skb(opt_skb);
1656         kfree_skb(skb);
1657         return 0;
1658 csum_err:
1659         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1660         goto discard;
1661
1662
1663 ipv6_pktoptions:
1664         /* Do you ask, what is it?
1665
1666            1. skb was enqueued by tcp.
1667            2. skb is added to tail of read queue, rather than out of order.
1668            3. socket is not in passive state.
1669            4. Finally, it really contains options, which user wants to receive.
1670          */
1671         tp = tcp_sk(sk);
1672         if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1673             !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1674                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1675                         np->mcast_oif = inet6_iif(opt_skb);
1676                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1677                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1678                 if (ipv6_opt_accepted(sk, opt_skb)) {
1679                         skb_set_owner_r(opt_skb, sk);
1680                         opt_skb = xchg(&np->pktoptions, opt_skb);
1681                 } else {
1682                         __kfree_skb(opt_skb);
1683                         opt_skb = xchg(&np->pktoptions, NULL);
1684                 }
1685         }
1686
1687         kfree_skb(opt_skb);
1688         return 0;
1689 }
1690
1691 static int tcp_v6_rcv(struct sk_buff *skb)
1692 {
1693         const struct tcphdr *th;
1694         const struct ipv6hdr *hdr;
1695         struct sock *sk;
1696         int ret;
1697         struct net *net = dev_net(skb->dev);
1698
1699         if (skb->pkt_type != PACKET_HOST)
1700                 goto discard_it;
1701
1702         /*
1703          *      Count it even if it's bad.
1704          */
1705         TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1706
1707         if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1708                 goto discard_it;
1709
1710         th = tcp_hdr(skb);
1711
1712         if (th->doff < sizeof(struct tcphdr)/4)
1713                 goto bad_packet;
1714         if (!pskb_may_pull(skb, th->doff*4))
1715                 goto discard_it;
1716
1717         if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1718                 goto bad_packet;
1719
1720         th = tcp_hdr(skb);
1721         hdr = ipv6_hdr(skb);
1722         TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1723         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1724                                     skb->len - th->doff*4);
1725         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1726         TCP_SKB_CB(skb)->when = 0;
1727         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1728         TCP_SKB_CB(skb)->sacked = 0;
1729
1730         sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1731         if (!sk)
1732                 goto no_tcp_socket;
1733
1734 process:
1735         if (sk->sk_state == TCP_TIME_WAIT)
1736                 goto do_time_wait;
1737
1738         if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1739                 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1740                 goto discard_and_relse;
1741         }
1742
1743         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1744                 goto discard_and_relse;
1745
1746         if (sk_filter(sk, skb))
1747                 goto discard_and_relse;
1748
1749         skb->dev = NULL;
1750
1751         bh_lock_sock_nested(sk);
1752         ret = 0;
1753         if (!sock_owned_by_user(sk)) {
1754 #ifdef CONFIG_NET_DMA
1755                 struct tcp_sock *tp = tcp_sk(sk);
1756                 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1757                         tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1758                 if (tp->ucopy.dma_chan)
1759                         ret = tcp_v6_do_rcv(sk, skb);
1760                 else
1761 #endif
1762                 {
1763                         if (!tcp_prequeue(sk, skb))
1764                                 ret = tcp_v6_do_rcv(sk, skb);
1765                 }
1766         } else if (unlikely(sk_add_backlog(sk, skb))) {
1767                 bh_unlock_sock(sk);
1768                 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1769                 goto discard_and_relse;
1770         }
1771         bh_unlock_sock(sk);
1772
1773         sock_put(sk);
1774         return ret ? -1 : 0;
1775
1776 no_tcp_socket:
1777         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1778                 goto discard_it;
1779
1780         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1781 bad_packet:
1782                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1783         } else {
1784                 tcp_v6_send_reset(NULL, skb);
1785         }
1786
1787 discard_it:
1788
1789         /*
1790          *      Discard frame
1791          */
1792
1793         kfree_skb(skb);
1794         return 0;
1795
1796 discard_and_relse:
1797         sock_put(sk);
1798         goto discard_it;
1799
1800 do_time_wait:
1801         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1802                 inet_twsk_put(inet_twsk(sk));
1803                 goto discard_it;
1804         }
1805
1806         if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1807                 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1808                 inet_twsk_put(inet_twsk(sk));
1809                 goto discard_it;
1810         }
1811
1812         switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1813         case TCP_TW_SYN:
1814         {
1815                 struct sock *sk2;
1816
1817                 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1818                                             &ipv6_hdr(skb)->daddr,
1819                                             ntohs(th->dest), inet6_iif(skb));
1820                 if (sk2 != NULL) {
1821                         struct inet_timewait_sock *tw = inet_twsk(sk);
1822                         inet_twsk_deschedule(tw, &tcp_death_row);
1823                         inet_twsk_put(tw);
1824                         sk = sk2;
1825                         goto process;
1826                 }
1827                 /* Fall through to ACK */
1828         }
1829         case TCP_TW_ACK:
1830                 tcp_v6_timewait_ack(sk, skb);
1831                 break;
1832         case TCP_TW_RST:
1833                 goto no_tcp_socket;
1834         case TCP_TW_SUCCESS:;
1835         }
1836         goto discard_it;
1837 }
1838
1839 static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1840 {
1841         struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1842         struct ipv6_pinfo *np = inet6_sk(sk);
1843         struct inet_peer *peer;
1844
1845         if (!rt ||
1846             !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1847                 peer = inet_getpeer_v6(&np->daddr, 1);
1848                 *release_it = true;
1849         } else {
1850                 if (!rt->rt6i_peer)
1851                         rt6_bind_peer(rt, 1);
1852                 peer = rt->rt6i_peer;
1853                 *release_it = false;
1854         }
1855
1856         return peer;
1857 }
1858
1859 static void *tcp_v6_tw_get_peer(struct sock *sk)
1860 {
1861         const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1862         const struct inet_timewait_sock *tw = inet_twsk(sk);
1863
1864         if (tw->tw_family == AF_INET)
1865                 return tcp_v4_tw_get_peer(sk);
1866
1867         return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1868 }
1869
1870 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1871         .twsk_obj_size  = sizeof(struct tcp6_timewait_sock),
1872         .twsk_unique    = tcp_twsk_unique,
1873         .twsk_destructor= tcp_twsk_destructor,
1874         .twsk_getpeer   = tcp_v6_tw_get_peer,
1875 };
1876
1877 static const struct inet_connection_sock_af_ops ipv6_specific = {
1878         .queue_xmit        = inet6_csk_xmit,
1879         .send_check        = tcp_v6_send_check,
1880         .rebuild_header    = inet6_sk_rebuild_header,
1881         .conn_request      = tcp_v6_conn_request,
1882         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1883         .get_peer          = tcp_v6_get_peer,
1884         .net_header_len    = sizeof(struct ipv6hdr),
1885         .setsockopt        = ipv6_setsockopt,
1886         .getsockopt        = ipv6_getsockopt,
1887         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1888         .sockaddr_len      = sizeof(struct sockaddr_in6),
1889         .bind_conflict     = inet6_csk_bind_conflict,
1890 #ifdef CONFIG_COMPAT
1891         .compat_setsockopt = compat_ipv6_setsockopt,
1892         .compat_getsockopt = compat_ipv6_getsockopt,
1893 #endif
1894 };
1895
1896 #ifdef CONFIG_TCP_MD5SIG
1897 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1898         .md5_lookup     =       tcp_v6_md5_lookup,
1899         .calc_md5_hash  =       tcp_v6_md5_hash_skb,
1900         .md5_add        =       tcp_v6_md5_add_func,
1901         .md5_parse      =       tcp_v6_parse_md5_keys,
1902 };
1903 #endif
1904
1905 /*
1906  *      TCP over IPv4 via INET6 API
1907  */
1908
1909 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1910         .queue_xmit        = ip_queue_xmit,
1911         .send_check        = tcp_v4_send_check,
1912         .rebuild_header    = inet_sk_rebuild_header,
1913         .conn_request      = tcp_v6_conn_request,
1914         .syn_recv_sock     = tcp_v6_syn_recv_sock,
1915         .get_peer          = tcp_v4_get_peer,
1916         .net_header_len    = sizeof(struct iphdr),
1917         .setsockopt        = ipv6_setsockopt,
1918         .getsockopt        = ipv6_getsockopt,
1919         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1920         .sockaddr_len      = sizeof(struct sockaddr_in6),
1921         .bind_conflict     = inet6_csk_bind_conflict,
1922 #ifdef CONFIG_COMPAT
1923         .compat_setsockopt = compat_ipv6_setsockopt,
1924         .compat_getsockopt = compat_ipv6_getsockopt,
1925 #endif
1926 };
1927
1928 #ifdef CONFIG_TCP_MD5SIG
1929 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1930         .md5_lookup     =       tcp_v4_md5_lookup,
1931         .calc_md5_hash  =       tcp_v4_md5_hash_skb,
1932         .md5_add        =       tcp_v6_md5_add_func,
1933         .md5_parse      =       tcp_v6_parse_md5_keys,
1934 };
1935 #endif
1936
1937 /* NOTE: A lot of things set to zero explicitly by call to
1938  *       sk_alloc() so need not be done here.
1939  */
1940 static int tcp_v6_init_sock(struct sock *sk)
1941 {
1942         struct inet_connection_sock *icsk = inet_csk(sk);
1943         struct tcp_sock *tp = tcp_sk(sk);
1944
1945         skb_queue_head_init(&tp->out_of_order_queue);
1946         tcp_init_xmit_timers(sk);
1947         tcp_prequeue_init(tp);
1948
1949         icsk->icsk_rto = TCP_TIMEOUT_INIT;
1950         tp->mdev = TCP_TIMEOUT_INIT;
1951
1952         /* So many TCP implementations out there (incorrectly) count the
1953          * initial SYN frame in their delayed-ACK and congestion control
1954          * algorithms that we must have the following bandaid to talk
1955          * efficiently to them.  -DaveM
1956          */
1957         tp->snd_cwnd = 2;
1958
1959         /* See draft-stevens-tcpca-spec-01 for discussion of the
1960          * initialization of these values.
1961          */
1962         tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1963         tp->snd_cwnd_clamp = ~0;
1964         tp->mss_cache = TCP_MSS_DEFAULT;
1965
1966         tp->reordering = sysctl_tcp_reordering;
1967
1968         sk->sk_state = TCP_CLOSE;
1969
1970         icsk->icsk_af_ops = &ipv6_specific;
1971         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1972         icsk->icsk_sync_mss = tcp_sync_mss;
1973         sk->sk_write_space = sk_stream_write_space;
1974         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1975
1976 #ifdef CONFIG_TCP_MD5SIG
1977         tp->af_specific = &tcp_sock_ipv6_specific;
1978 #endif
1979
1980         /* TCP Cookie Transactions */
1981         if (sysctl_tcp_cookie_size > 0) {
1982                 /* Default, cookies without s_data_payload. */
1983                 tp->cookie_values =
1984                         kzalloc(sizeof(*tp->cookie_values),
1985                                 sk->sk_allocation);
1986                 if (tp->cookie_values != NULL)
1987                         kref_init(&tp->cookie_values->kref);
1988         }
1989         /* Presumed zeroed, in order of appearance:
1990          *      cookie_in_always, cookie_out_never,
1991          *      s_data_constant, s_data_in, s_data_out
1992          */
1993         sk->sk_sndbuf = sysctl_tcp_wmem[1];
1994         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1995
1996         local_bh_disable();
1997         percpu_counter_inc(&tcp_sockets_allocated);
1998         local_bh_enable();
1999
2000         return 0;
2001 }
2002
2003 static void tcp_v6_destroy_sock(struct sock *sk)
2004 {
2005 #ifdef CONFIG_TCP_MD5SIG
2006         /* Clean up the MD5 key list */
2007         if (tcp_sk(sk)->md5sig_info)
2008                 tcp_v6_clear_md5_list(sk);
2009 #endif
2010         tcp_v4_destroy_sock(sk);
2011         inet6_destroy_sock(sk);
2012 }
2013
2014 #ifdef CONFIG_PROC_FS
2015 /* Proc filesystem TCPv6 sock list dumping. */
2016 static void get_openreq6(struct seq_file *seq,
2017                          const struct sock *sk, struct request_sock *req, int i, int uid)
2018 {
2019         int ttd = req->expires - jiffies;
2020         const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
2021         const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
2022
2023         if (ttd < 0)
2024                 ttd = 0;
2025
2026         seq_printf(seq,
2027                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2028                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2029                    i,
2030                    src->s6_addr32[0], src->s6_addr32[1],
2031                    src->s6_addr32[2], src->s6_addr32[3],
2032                    ntohs(inet_rsk(req)->loc_port),
2033                    dest->s6_addr32[0], dest->s6_addr32[1],
2034                    dest->s6_addr32[2], dest->s6_addr32[3],
2035                    ntohs(inet_rsk(req)->rmt_port),
2036                    TCP_SYN_RECV,
2037                    0,0, /* could print option size, but that is af dependent. */
2038                    1,   /* timers active (only the expire timer) */
2039                    jiffies_to_clock_t(ttd),
2040                    req->retrans,
2041                    uid,
2042                    0,  /* non standard timer */
2043                    0, /* open_requests have no inode */
2044                    0, req);
2045 }
2046
2047 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2048 {
2049         const struct in6_addr *dest, *src;
2050         __u16 destp, srcp;
2051         int timer_active;
2052         unsigned long timer_expires;
2053         const struct inet_sock *inet = inet_sk(sp);
2054         const struct tcp_sock *tp = tcp_sk(sp);
2055         const struct inet_connection_sock *icsk = inet_csk(sp);
2056         const struct ipv6_pinfo *np = inet6_sk(sp);
2057
2058         dest  = &np->daddr;
2059         src   = &np->rcv_saddr;
2060         destp = ntohs(inet->inet_dport);
2061         srcp  = ntohs(inet->inet_sport);
2062
2063         if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2064                 timer_active    = 1;
2065                 timer_expires   = icsk->icsk_timeout;
2066         } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2067                 timer_active    = 4;
2068                 timer_expires   = icsk->icsk_timeout;
2069         } else if (timer_pending(&sp->sk_timer)) {
2070                 timer_active    = 2;
2071                 timer_expires   = sp->sk_timer.expires;
2072         } else {
2073                 timer_active    = 0;
2074                 timer_expires = jiffies;
2075         }
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 %lu %d %pK %lu %lu %u %u %d\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                    sp->sk_state,
2086                    tp->write_seq-tp->snd_una,
2087                    (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2088                    timer_active,
2089                    jiffies_to_clock_t(timer_expires - jiffies),
2090                    icsk->icsk_retransmits,
2091                    sock_i_uid(sp),
2092                    icsk->icsk_probes_out,
2093                    sock_i_ino(sp),
2094                    atomic_read(&sp->sk_refcnt), sp,
2095                    jiffies_to_clock_t(icsk->icsk_rto),
2096                    jiffies_to_clock_t(icsk->icsk_ack.ato),
2097                    (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2098                    tp->snd_cwnd,
2099                    tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
2100                    );
2101 }
2102
2103 static void get_timewait6_sock(struct seq_file *seq,
2104                                struct inet_timewait_sock *tw, int i)
2105 {
2106         const struct in6_addr *dest, *src;
2107         __u16 destp, srcp;
2108         const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2109         int ttd = tw->tw_ttd - jiffies;
2110
2111         if (ttd < 0)
2112                 ttd = 0;
2113
2114         dest = &tw6->tw_v6_daddr;
2115         src  = &tw6->tw_v6_rcv_saddr;
2116         destp = ntohs(tw->tw_dport);
2117         srcp  = ntohs(tw->tw_sport);
2118
2119         seq_printf(seq,
2120                    "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2121                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2122                    i,
2123                    src->s6_addr32[0], src->s6_addr32[1],
2124                    src->s6_addr32[2], src->s6_addr32[3], srcp,
2125                    dest->s6_addr32[0], dest->s6_addr32[1],
2126                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
2127                    tw->tw_substate, 0, 0,
2128                    3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2129                    atomic_read(&tw->tw_refcnt), tw);
2130 }
2131
2132 static int tcp6_seq_show(struct seq_file *seq, void *v)
2133 {
2134         struct tcp_iter_state *st;
2135
2136         if (v == SEQ_START_TOKEN) {
2137                 seq_puts(seq,
2138                          "  sl  "
2139                          "local_address                         "
2140                          "remote_address                        "
2141                          "st tx_queue rx_queue tr tm->when retrnsmt"
2142                          "   uid  timeout inode\n");
2143                 goto out;
2144         }
2145         st = seq->private;
2146
2147         switch (st->state) {
2148         case TCP_SEQ_STATE_LISTENING:
2149         case TCP_SEQ_STATE_ESTABLISHED:
2150                 get_tcp6_sock(seq, v, st->num);
2151                 break;
2152         case TCP_SEQ_STATE_OPENREQ:
2153                 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2154                 break;
2155         case TCP_SEQ_STATE_TIME_WAIT:
2156                 get_timewait6_sock(seq, v, st->num);
2157                 break;
2158         }
2159 out:
2160         return 0;
2161 }
2162
2163 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2164         .name           = "tcp6",
2165         .family         = AF_INET6,
2166         .seq_fops       = {
2167                 .owner          = THIS_MODULE,
2168         },
2169         .seq_ops        = {
2170                 .show           = tcp6_seq_show,
2171         },
2172 };
2173
2174 int __net_init tcp6_proc_init(struct net *net)
2175 {
2176         return tcp_proc_register(net, &tcp6_seq_afinfo);
2177 }
2178
2179 void tcp6_proc_exit(struct net *net)
2180 {
2181         tcp_proc_unregister(net, &tcp6_seq_afinfo);
2182 }
2183 #endif
2184
2185 struct proto tcpv6_prot = {
2186         .name                   = "TCPv6",
2187         .owner                  = THIS_MODULE,
2188         .close                  = tcp_close,
2189         .connect                = tcp_v6_connect,
2190         .disconnect             = tcp_disconnect,
2191         .accept                 = inet_csk_accept,
2192         .ioctl                  = tcp_ioctl,
2193         .init                   = tcp_v6_init_sock,
2194         .destroy                = tcp_v6_destroy_sock,
2195         .shutdown               = tcp_shutdown,
2196         .setsockopt             = tcp_setsockopt,
2197         .getsockopt             = tcp_getsockopt,
2198         .recvmsg                = tcp_recvmsg,
2199         .sendmsg                = tcp_sendmsg,
2200         .sendpage               = tcp_sendpage,
2201         .backlog_rcv            = tcp_v6_do_rcv,
2202         .hash                   = tcp_v6_hash,
2203         .unhash                 = inet_unhash,
2204         .get_port               = inet_csk_get_port,
2205         .enter_memory_pressure  = tcp_enter_memory_pressure,
2206         .sockets_allocated      = &tcp_sockets_allocated,
2207         .memory_allocated       = &tcp_memory_allocated,
2208         .memory_pressure        = &tcp_memory_pressure,
2209         .orphan_count           = &tcp_orphan_count,
2210         .sysctl_mem             = sysctl_tcp_mem,
2211         .sysctl_wmem            = sysctl_tcp_wmem,
2212         .sysctl_rmem            = sysctl_tcp_rmem,
2213         .max_header             = MAX_TCP_HEADER,
2214         .obj_size               = sizeof(struct tcp6_sock),
2215         .slab_flags             = SLAB_DESTROY_BY_RCU,
2216         .twsk_prot              = &tcp6_timewait_sock_ops,
2217         .rsk_prot               = &tcp6_request_sock_ops,
2218         .h.hashinfo             = &tcp_hashinfo,
2219         .no_autobind            = true,
2220 #ifdef CONFIG_COMPAT
2221         .compat_setsockopt      = compat_tcp_setsockopt,
2222         .compat_getsockopt      = compat_tcp_getsockopt,
2223 #endif
2224 };
2225
2226 static const struct inet6_protocol tcpv6_protocol = {
2227         .handler        =       tcp_v6_rcv,
2228         .err_handler    =       tcp_v6_err,
2229         .gso_send_check =       tcp_v6_gso_send_check,
2230         .gso_segment    =       tcp_tso_segment,
2231         .gro_receive    =       tcp6_gro_receive,
2232         .gro_complete   =       tcp6_gro_complete,
2233         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2234 };
2235
2236 static struct inet_protosw tcpv6_protosw = {
2237         .type           =       SOCK_STREAM,
2238         .protocol       =       IPPROTO_TCP,
2239         .prot           =       &tcpv6_prot,
2240         .ops            =       &inet6_stream_ops,
2241         .no_check       =       0,
2242         .flags          =       INET_PROTOSW_PERMANENT |
2243                                 INET_PROTOSW_ICSK,
2244 };
2245
2246 static int __net_init tcpv6_net_init(struct net *net)
2247 {
2248         return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2249                                     SOCK_RAW, IPPROTO_TCP, net);
2250 }
2251
2252 static void __net_exit tcpv6_net_exit(struct net *net)
2253 {
2254         inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2255 }
2256
2257 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2258 {
2259         inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2260 }
2261
2262 static struct pernet_operations tcpv6_net_ops = {
2263         .init       = tcpv6_net_init,
2264         .exit       = tcpv6_net_exit,
2265         .exit_batch = tcpv6_net_exit_batch,
2266 };
2267
2268 int __init tcpv6_init(void)
2269 {
2270         int ret;
2271
2272         ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2273         if (ret)
2274                 goto out;
2275
2276         /* register inet6 protocol */
2277         ret = inet6_register_protosw(&tcpv6_protosw);
2278         if (ret)
2279                 goto out_tcpv6_protocol;
2280
2281         ret = register_pernet_subsys(&tcpv6_net_ops);
2282         if (ret)
2283                 goto out_tcpv6_protosw;
2284 out:
2285         return ret;
2286
2287 out_tcpv6_protocol:
2288         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2289 out_tcpv6_protosw:
2290         inet6_unregister_protosw(&tcpv6_protosw);
2291         goto out;
2292 }
2293
2294 void tcpv6_exit(void)
2295 {
2296         unregister_pernet_subsys(&tcpv6_net_ops);
2297         inet6_unregister_protosw(&tcpv6_protosw);
2298         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2299 }