net/dccp/ipv4.c

   1 /*
   2  *  net/dccp/ipv4.c
   3  *
   4  *  An implementation of the DCCP protocol
   5  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/dccp.h>
  15 #include <linux/icmp.h>
  16 #include <linux/module.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/random.h>
  19
  20 #include <net/icmp.h>
  21 #include <net/inet_hashtables.h>
  22 #include <net/sock.h>
  23 #include <net/tcp_states.h>
  24 #include <net/xfrm.h>
  25
  26 #include "ackvec.h"
  27 #include "ccid.h"
  28 #include "dccp.h"
  29
  30 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
  31         .lhash_lock     = RW_LOCK_UNLOCKED,
  32         .lhash_users    = ATOMIC_INIT(0),
  33         .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
  34         .portalloc_lock = SPIN_LOCK_UNLOCKED,
  35         .port_rover     = 1024 - 1,
  36 };
  37
  38 EXPORT_SYMBOL_GPL(dccp_hashinfo);
  39
  40 static int dccp_v4_get_port(struct sock *sk, const unsigned short snum)
  41 {
  42         return inet_csk_get_port(&dccp_hashinfo, sk, snum);
  43 }
  44
  45 static void dccp_v4_hash(struct sock *sk)
  46 {
  47         inet_hash(&dccp_hashinfo, sk);
  48 }
  49
  50 static void dccp_v4_unhash(struct sock *sk)
  51 {
  52         inet_unhash(&dccp_hashinfo, sk);
  53 }
  54
  55 /* called with local bh disabled */
  56 static int __dccp_v4_check_established(struct sock *sk, const __u16 lport,
  57                                       struct inet_timewait_sock **twp)
  58 {
  59         struct inet_sock *inet = inet_sk(sk);
  60         const u32 daddr = inet->rcv_saddr;
  61         const u32 saddr = inet->daddr;
  62         const int dif = sk->sk_bound_dev_if;
  63         INET_ADDR_COOKIE(acookie, saddr, daddr)
  64         const __u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
  65         unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
  66         struct inet_ehash_bucket *head = inet_ehash_bucket(&dccp_hashinfo, hash);
  67         const struct sock *sk2;
  68         const struct hlist_node *node;
  69         struct inet_timewait_sock *tw;
  70
  71         prefetch(head->chain.first);
  72         write_lock(&head->lock);
  73
  74         /* Check TIME-WAIT sockets first. */
  75         sk_for_each(sk2, node, &(head + dccp_hashinfo.ehash_size)->chain) {
  76                 tw = inet_twsk(sk2);
  77
  78                 if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
  79                         goto not_unique;
  80         }
  81         tw = NULL;
  82
  83         /* And established part... */
  84         sk_for_each(sk2, node, &head->chain) {
  85                 if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
  86                         goto not_unique;
  87         }
  88
  89         /* Must record num and sport now. Otherwise we will see
  90          * in hash table socket with a funny identity. */
  91         inet->num = lport;
  92         inet->sport = htons(lport);
  93         sk->sk_hash = hash;
  94         BUG_TRAP(sk_unhashed(sk));
  95         __sk_add_node(sk, &head->chain);
  96         sock_prot_inc_use(sk->sk_prot);
  97         write_unlock(&head->lock);
  98
  99         if (twp != NULL) {
 100                 *twp = tw;
 101                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
 102         } else if (tw != NULL) {
 103                 /* Silly. Should hash-dance instead... */
 104                 inet_twsk_deschedule(tw, &dccp_death_row);
 105                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
 106
 107                 inet_twsk_put(tw);
 108         }
 109
 110         return 0;
 111
 112 not_unique:
 113         write_unlock(&head->lock);
 114         return -EADDRNOTAVAIL;
 115 }
 116
 117 /*
 118  * Bind a port for a connect operation and hash it.
 119  */
 120 static int dccp_v4_hash_connect(struct sock *sk)
 121 {
 122         const unsigned short snum = inet_sk(sk)->num;
 123         struct inet_bind_hashbucket *head;
 124         struct inet_bind_bucket *tb;
 125         int ret;
 126
 127         if (snum == 0) {
 128                 int rover;
 129                 int low = sysctl_local_port_range[0];
 130                 int high = sysctl_local_port_range[1];
 131                 int remaining = (high - low) + 1;
 132                 struct hlist_node *node;
 133                 struct inet_timewait_sock *tw = NULL;
 134
 135                 local_bh_disable();
 136
 137                 /* TODO. Actually it is not so bad idea to remove
 138                  * dccp_hashinfo.portalloc_lock before next submission to
 139                  * Linus.
 140                  * As soon as we touch this place at all it is time to think.
 141                  *
 142                  * Now it protects single _advisory_ variable
 143                  * dccp_hashinfo.port_rover, hence it is mostly useless.
 144                  * Code will work nicely if we just delete it, but
 145                  * I am afraid in contented case it will work not better or
 146                  * even worse: another cpu just will hit the same bucket
 147                  * and spin there.
 148                  * So some cpu salt could remove both contention and
 149                  * memory pingpong. Any ideas how to do this in a nice way?
 150                  */
 151                 spin_lock(&dccp_hashinfo.portalloc_lock);
 152                 rover = dccp_hashinfo.port_rover;
 153
 154                 do {
 155                         rover++;
 156                         if ((rover < low) || (rover > high))
 157                                 rover = low;
 158                         head = &dccp_hashinfo.bhash[inet_bhashfn(rover,
 159                                                     dccp_hashinfo.bhash_size)];
 160                         spin_lock(&head->lock);
 161
 162                         /* Does not bother with rcv_saddr checks,
 163                          * because the established check is already
 164                          * unique enough.
 165                          */
 166                         inet_bind_bucket_for_each(tb, node, &head->chain) {
 167                                 if (tb->port == rover) {
 168                                         BUG_TRAP(!hlist_empty(&tb->owners));
 169                                         if (tb->fastreuse >= 0)
 170                                                 goto next_port;
 171                                         if (!__dccp_v4_check_established(sk,
 172                                                                          rover,
 173                                                                          &tw))
 174                                                 goto ok;
 175                                         goto next_port;
 176                                 }
 177                         }
 178
 179                         tb = inet_bind_bucket_create(dccp_hashinfo.bind_bucket_cachep,
 180                                                      head, rover);
 181                         if (tb == NULL) {
 182                                 spin_unlock(&head->lock);
 183                                 break;
 184                         }
 185                         tb->fastreuse = -1;
 186                         goto ok;
 187
 188                 next_port:
 189                         spin_unlock(&head->lock);
 190                 } while (--remaining > 0);
 191                 dccp_hashinfo.port_rover = rover;
 192                 spin_unlock(&dccp_hashinfo.portalloc_lock);
 193
 194                 local_bh_enable();
 195
 196                 return -EADDRNOTAVAIL;
 197
 198 ok:
 199                 /* All locks still held and bhs disabled */
 200                 dccp_hashinfo.port_rover = rover;
 201                 spin_unlock(&dccp_hashinfo.portalloc_lock);
 202
 203                 inet_bind_hash(sk, tb, rover);
 204                 if (sk_unhashed(sk)) {
 205                         inet_sk(sk)->sport = htons(rover);
 206                         __inet_hash(&dccp_hashinfo, sk, 0);
 207                 }
 208                 spin_unlock(&head->lock);
 209
 210                 if (tw != NULL) {
 211                         inet_twsk_deschedule(tw, &dccp_death_row);
 212                         inet_twsk_put(tw);
 213                 }
 214
 215                 ret = 0;
 216                 goto out;
 217         }
 218
 219         head = &dccp_hashinfo.bhash[inet_bhashfn(snum,
 220                                                  dccp_hashinfo.bhash_size)];
 221         tb   = inet_csk(sk)->icsk_bind_hash;
 222         spin_lock_bh(&head->lock);
 223         if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
 224                 __inet_hash(&dccp_hashinfo, sk, 0);
 225                 spin_unlock_bh(&head->lock);
 226                 return 0;
 227         } else {
 228                 spin_unlock(&head->lock);
 229                 /* No definite answer... Walk to established hash table */
 230                 ret = __dccp_v4_check_established(sk, snum, NULL);
 231 out:
 232                 local_bh_enable();
 233                 return ret;
 234         }
 235 }
 236
 237 static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 238                            int addr_len)
 239 {
 240         struct inet_sock *inet = inet_sk(sk);
 241         struct dccp_sock *dp = dccp_sk(sk);
 242         const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
 243         struct rtable *rt;
 244         u32 daddr, nexthop;
 245         int tmp;
 246         int err;
 247
 248         dp->dccps_role = DCCP_ROLE_CLIENT;
 249
 250         if (dccp_service_not_initialized(sk))
 251                 return -EPROTO;
 252
 253         if (addr_len < sizeof(struct sockaddr_in))
 254                 return -EINVAL;
 255
 256         if (usin->sin_family != AF_INET)
 257                 return -EAFNOSUPPORT;
 258
 259         nexthop = daddr = usin->sin_addr.s_addr;
 260         if (inet->opt != NULL && inet->opt->srr) {
 261                 if (daddr == 0)
 262                         return -EINVAL;
 263                 nexthop = inet->opt->faddr;
 264         }
 265
 266         tmp = ip_route_connect(&rt, nexthop, inet->saddr,
 267                                RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
 268                                IPPROTO_DCCP,
 269                                inet->sport, usin->sin_port, sk);
 270         if (tmp < 0)
 271                 return tmp;
 272
 273         if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
 274                 ip_rt_put(rt);
 275                 return -ENETUNREACH;
 276         }
 277
 278         if (inet->opt == NULL || !inet->opt->srr)
 279                 daddr = rt->rt_dst;
 280
 281         if (inet->saddr == 0)
 282                 inet->saddr = rt->rt_src;
 283         inet->rcv_saddr = inet->saddr;
 284
 285         inet->dport = usin->sin_port;
 286         inet->daddr = daddr;
 287
 288         dp->dccps_ext_header_len = 0;
 289         if (inet->opt != NULL)
 290                 dp->dccps_ext_header_len = inet->opt->optlen;
 291         /*
 292          * Socket identity is still unknown (sport may be zero).
 293          * However we set state to DCCP_REQUESTING and not releasing socket
 294          * lock select source port, enter ourselves into the hash tables and
 295          * complete initialization after this.
 296          */
 297         dccp_set_state(sk, DCCP_REQUESTING);
 298         err = dccp_v4_hash_connect(sk);
 299         if (err != 0)
 300                 goto failure;
 301
 302         err = ip_route_newports(&rt, inet->sport, inet->dport, sk);
 303         if (err != 0)
 304                 goto failure;
 305
 306         /* OK, now commit destination to socket.  */
 307         sk_setup_caps(sk, &rt->u.dst);
 308
 309         dp->dccps_gar =
 310                 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
 311                                                             inet->daddr,
 312                                                             inet->sport,
 313                                                             usin->sin_port);
 314         dccp_update_gss(sk, dp->dccps_iss);
 315
 316         /*
 317          * SWL and AWL are initially adjusted so that they are not less than
 318          * the initial Sequence Numbers received and sent, respectively:
 319          *      SWL := max(GSR + 1 - floor(W/4), ISR),
 320          *      AWL := max(GSS - W' + 1, ISS).
 321          * These adjustments MUST be applied only at the beginning of the
 322          * connection.
 323          */
 324         dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
 325
 326         inet->id = dp->dccps_iss ^ jiffies;
 327
 328         err = dccp_connect(sk);
 329         rt = NULL;
 330         if (err != 0)
 331                 goto failure;
 332 out:
 333         return err;
 334 failure:
 335         /*
 336          * This unhashes the socket and releases the local port, if necessary.
 337          */
 338         dccp_set_state(sk, DCCP_CLOSED);
 339         ip_rt_put(rt);
 340         sk->sk_route_caps = 0;
 341         inet->dport = 0;
 342         goto out;
 343 }
 344
 345 /*
 346  * This routine does path mtu discovery as defined in RFC1191.
 347  */
 348 static inline void dccp_do_pmtu_discovery(struct sock *sk,
 349                                           const struct iphdr *iph,
 350                                           u32 mtu)
 351 {
 352         struct dst_entry *dst;
 353         const struct inet_sock *inet = inet_sk(sk);
 354         const struct dccp_sock *dp = dccp_sk(sk);
 355
 356         /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
 357          * send out by Linux are always < 576bytes so they should go through
 358          * unfragmented).
 359          */
 360         if (sk->sk_state == DCCP_LISTEN)
 361                 return;
 362
 363         /* We don't check in the destentry if pmtu discovery is forbidden
 364          * on this route. We just assume that no packet_to_big packets
 365          * are send back when pmtu discovery is not active.
 366          * There is a small race when the user changes this flag in the
 367          * route, but I think that's acceptable.
 368          */
 369         if ((dst = __sk_dst_check(sk, 0)) == NULL)
 370                 return;
 371
 372         dst->ops->update_pmtu(dst, mtu);
 373
 374         /* Something is about to be wrong... Remember soft error
 375          * for the case, if this connection will not able to recover.
 376          */
 377         if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
 378                 sk->sk_err_soft = EMSGSIZE;
 379
 380         mtu = dst_mtu(dst);
 381
 382         if (inet->pmtudisc != IP_PMTUDISC_DONT &&
 383             dp->dccps_pmtu_cookie > mtu) {
 384                 dccp_sync_mss(sk, mtu);
 385
 386                 /*
 387                  * From: draft-ietf-dccp-spec-11.txt
 388                  *
 389                  *      DCCP-Sync packets are the best choice for upward
 390                  *      probing, since DCCP-Sync probes do not risk application
 391                  *      data loss.
 392                  */
 393                 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
 394         } /* else let the usual retransmit timer handle it */
 395 }
 396
 397 static void dccp_v4_ctl_send_ack(struct sk_buff *rxskb)
 398 {
 399         int err;
 400         struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
 401         const int dccp_hdr_ack_len = sizeof(struct dccp_hdr) +
 402                                      sizeof(struct dccp_hdr_ext) +
 403                                      sizeof(struct dccp_hdr_ack_bits);
 404         struct sk_buff *skb;
 405
 406         if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
 407                 return;
 408
 409         skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC);
 410         if (skb == NULL)
 411                 return;
 412
 413         /* Reserve space for headers. */
 414         skb_reserve(skb, MAX_DCCP_HEADER);
 415
 416         skb->dst = dst_clone(rxskb->dst);
 417
 418         skb->h.raw = skb_push(skb, dccp_hdr_ack_len);
 419         dh = dccp_hdr(skb);
 420         memset(dh, 0, dccp_hdr_ack_len);
 421
 422         /* Build DCCP header and checksum it. */
 423         dh->dccph_type     = DCCP_PKT_ACK;
 424         dh->dccph_sport    = rxdh->dccph_dport;
 425         dh->dccph_dport    = rxdh->dccph_sport;
 426         dh->dccph_doff     = dccp_hdr_ack_len / 4;
 427         dh->dccph_x        = 1;
 428
 429         dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
 430         dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
 431                          DCCP_SKB_CB(rxskb)->dccpd_seq);
 432
 433         bh_lock_sock(dccp_ctl_socket->sk);
 434         err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk,
 435                                     rxskb->nh.iph->daddr,
 436                                     rxskb->nh.iph->saddr, NULL);
 437         bh_unlock_sock(dccp_ctl_socket->sk);
 438
 439         if (err == NET_XMIT_CN || err == 0) {
 440                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
 441                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
 442         }
 443 }
 444
 445 static void dccp_v4_reqsk_send_ack(struct sk_buff *skb,
 446                                    struct request_sock *req)
 447 {
 448         dccp_v4_ctl_send_ack(skb);
 449 }
 450
 451 static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
 452                                  struct dst_entry *dst)
 453 {
 454         int err = -1;
 455         struct sk_buff *skb;
 456
 457         /* First, grab a route. */
 458
 459         if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
 460                 goto out;
 461
 462         skb = dccp_make_response(sk, dst, req);
 463         if (skb != NULL) {
 464                 const struct inet_request_sock *ireq = inet_rsk(req);
 465
 466                 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 467                 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
 468                                             ireq->rmt_addr,
 469                                             ireq->opt);
 470                 if (err == NET_XMIT_CN)
 471                         err = 0;
 472         }
 473
 474 out:
 475         dst_release(dst);
 476         return err;
 477 }
 478
 479 /*
 480  * This routine is called by the ICMP module when it gets some sort of error
 481  * condition. If err < 0 then the socket should be closed and the error
 482  * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
 483  * After adjustment header points to the first 8 bytes of the tcp header. We
 484  * need to find the appropriate port.
 485  *
 486  * The locking strategy used here is very "optimistic". When someone else
 487  * accesses the socket the ICMP is just dropped and for some paths there is no
 488  * check at all. A more general error queue to queue errors for later handling
 489  * is probably better.
 490  */
 491 void dccp_v4_err(struct sk_buff *skb, u32 info)
 492 {
 493         const struct iphdr *iph = (struct iphdr *)skb->data;
 494         const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
 495                                                         (iph->ihl << 2));
 496         struct dccp_sock *dp;
 497         struct inet_sock *inet;
 498         const int type = skb->h.icmph->type;
 499         const int code = skb->h.icmph->code;
 500         struct sock *sk;
 501         __u64 seq;
 502         int err;
 503
 504         if (skb->len < (iph->ihl << 2) + 8) {
 505                 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
 506                 return;
 507         }
 508
 509         sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport,
 510                          iph->saddr, dh->dccph_sport, inet_iif(skb));
 511         if (sk == NULL) {
 512                 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
 513                 return;
 514         }
 515
 516         if (sk->sk_state == DCCP_TIME_WAIT) {
 517                 inet_twsk_put((struct inet_timewait_sock *)sk);
 518                 return;
 519         }
 520
 521         bh_lock_sock(sk);
 522         /* If too many ICMPs get dropped on busy
 523          * servers this needs to be solved differently.
 524          */
 525         if (sock_owned_by_user(sk))
 526                 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
 527
 528         if (sk->sk_state == DCCP_CLOSED)
 529                 goto out;
 530
 531         dp = dccp_sk(sk);
 532         seq = dccp_hdr_seq(skb);
 533         if (sk->sk_state != DCCP_LISTEN &&
 534             !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
 535                 NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS);
 536                 goto out;
 537         }
 538
 539         switch (type) {
 540         case ICMP_SOURCE_QUENCH:
 541                 /* Just silently ignore these. */
 542                 goto out;
 543         case ICMP_PARAMETERPROB:
 544                 err = EPROTO;
 545                 break;
 546         case ICMP_DEST_UNREACH:
 547                 if (code > NR_ICMP_UNREACH)
 548                         goto out;
 549
 550                 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
 551                         if (!sock_owned_by_user(sk))
 552                                 dccp_do_pmtu_discovery(sk, iph, info);
 553                         goto out;
 554                 }
 555
 556                 err = icmp_err_convert[code].errno;
 557                 break;
 558         case ICMP_TIME_EXCEEDED:
 559                 err = EHOSTUNREACH;
 560                 break;
 561         default:
 562                 goto out;
 563         }
 564
 565         switch (sk->sk_state) {
 566                 struct request_sock *req , **prev;
 567         case DCCP_LISTEN:
 568                 if (sock_owned_by_user(sk))
 569                         goto out;
 570                 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
 571                                           iph->daddr, iph->saddr);
 572                 if (!req)
 573                         goto out;
 574
 575                 /*
 576                  * ICMPs are not backlogged, hence we cannot get an established
 577                  * socket here.
 578                  */
 579                 BUG_TRAP(!req->sk);
 580
 581                 if (seq != dccp_rsk(req)->dreq_iss) {
 582                         NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 583                         goto out;
 584                 }
 585                 /*
 586                  * Still in RESPOND, just remove it silently.
 587                  * There is no good way to pass the error to the newly
 588                  * created socket, and POSIX does not want network
 589                  * errors returned from accept().
 590                  */
 591                 inet_csk_reqsk_queue_drop(sk, req, prev);
 592                 goto out;
 593
 594         case DCCP_REQUESTING:
 595         case DCCP_RESPOND:
 596                 if (!sock_owned_by_user(sk)) {
 597                         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
 598                         sk->sk_err = err;
 599
 600                         sk->sk_error_report(sk);
 601
 602                         dccp_done(sk);
 603                 } else
 604                         sk->sk_err_soft = err;
 605                 goto out;
 606         }
 607
 608         /* If we've already connected we will keep trying
 609          * until we time out, or the user gives up.
 610          *
 611          * rfc1122 4.2.3.9 allows to consider as hard errors
 612          * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
 613          * but it is obsoleted by pmtu discovery).
 614          *
 615          * Note, that in modern internet, where routing is unreliable
 616          * and in each dark corner broken firewalls sit, sending random
 617          * errors ordered by their masters even this two messages finally lose
 618          * their original sense (even Linux sends invalid PORT_UNREACHs)
 619          *
 620          * Now we are in compliance with RFCs.
 621          *                                                      --ANK (980905)
 622          */
 623
 624         inet = inet_sk(sk);
 625         if (!sock_owned_by_user(sk) && inet->recverr) {
 626                 sk->sk_err = err;
 627                 sk->sk_error_report(sk);
 628         } else /* Only an error on timeout */
 629                 sk->sk_err_soft = err;
 630 out:
 631         bh_unlock_sock(sk);
 632         sock_put(sk);
 633 }
 634
 635 int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code)
 636 {
 637         struct sk_buff *skb;
 638         /*
 639          * FIXME: what if rebuild_header fails?
 640          * Should we be doing a rebuild_header here?
 641          */
 642         int err = inet_sk_rebuild_header(sk);
 643
 644         if (err != 0)
 645                 return err;
 646
 647         skb = dccp_make_reset(sk, sk->sk_dst_cache, code);
 648         if (skb != NULL) {
 649                 const struct inet_sock *inet = inet_sk(sk);
 650
 651                 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 652                 err = ip_build_and_send_pkt(skb, sk,
 653                                             inet->saddr, inet->daddr, NULL);
 654                 if (err == NET_XMIT_CN)
 655                         err = 0;
 656         }
 657
 658         return err;
 659 }
 660
 661 static inline u64 dccp_v4_init_sequence(const struct sock *sk,
 662                                         const struct sk_buff *skb)
 663 {
 664         return secure_dccp_sequence_number(skb->nh.iph->daddr,
 665                                            skb->nh.iph->saddr,
 666                                            dccp_hdr(skb)->dccph_dport,
 667                                            dccp_hdr(skb)->dccph_sport);
 668 }
 669
 670 static inline int dccp_bad_service_code(const struct sock *sk,
 671                                         const __u32 service)
 672 {
 673         const struct dccp_sock *dp = dccp_sk(sk);
 674
 675         if (dp->dccps_service == service)
 676                 return 0;
 677         return !dccp_list_has_service(dp->dccps_service_list, service);
 678 }
 679
 680 int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 681 {
 682         struct inet_request_sock *ireq;
 683         struct dccp_sock dp;
 684         struct request_sock *req;
 685         struct dccp_request_sock *dreq;
 686         const __u32 saddr = skb->nh.iph->saddr;
 687         const __u32 daddr = skb->nh.iph->daddr;
 688         const __u32 service = dccp_hdr_request(skb)->dccph_req_service;
 689         struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 690         __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
 691         struct dst_entry *dst = NULL;
 692
 693         /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
 694         if (((struct rtable *)skb->dst)->rt_flags &
 695             (RTCF_BROADCAST | RTCF_MULTICAST)) {
 696                 reset_code = DCCP_RESET_CODE_NO_CONNECTION;
 697                 goto drop;
 698         }
 699
 700         if (dccp_bad_service_code(sk, service)) {
 701                 reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 702                 goto drop;
 703         }
 704         /*
 705          * TW buckets are converted to open requests without
 706          * limitations, they conserve resources and peer is
 707          * evidently real one.
 708          */
 709         if (inet_csk_reqsk_queue_is_full(sk))
 710                 goto drop;
 711
 712         /*
 713          * Accept backlog is full. If we have already queued enough
 714          * of warm entries in syn queue, drop request. It is better than
 715          * clogging syn queue with openreqs with exponentially increasing
 716          * timeout.
 717          */
 718         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
 719                 goto drop;
 720
 721         req = reqsk_alloc(sk->sk_prot->rsk_prot);
 722         if (req == NULL)
 723                 goto drop;
 724
 725         /* FIXME: process options */
 726
 727         dccp_openreq_init(req, &dp, skb);
 728
 729         ireq = inet_rsk(req);
 730         ireq->loc_addr = daddr;
 731         ireq->rmt_addr = saddr;
 732         /* FIXME: Merge Aristeu's option parsing code when ready */
 733         req->rcv_wnd    = 100; /* Fake, option parsing will get the
 734                                   right value */
 735         ireq->opt       = NULL;
 736
 737         /*
 738          * Step 3: Process LISTEN state
 739          *
 740          * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
 741          *
 742          * In fact we defer setting S.GSR, S.SWL, S.SWH to
 743          * dccp_create_openreq_child.
 744          */
 745         dreq = dccp_rsk(req);
 746         dreq->dreq_isr     = dcb->dccpd_seq;
 747         dreq->dreq_iss     = dccp_v4_init_sequence(sk, skb);
 748         dreq->dreq_service = service;
 749
 750         if (dccp_v4_send_response(sk, req, dst))
 751                 goto drop_and_free;
 752
 753         inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
 754         return 0;
 755
 756 drop_and_free:
 757         /*
 758          * FIXME: should be reqsk_free after implementing req->rsk_ops
 759          */
 760         __reqsk_free(req);
 761 drop:
 762         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
 763         dcb->dccpd_reset_code = reset_code;
 764         return -1;
 765 }
 766
 767 /*
 768  * The three way handshake has completed - we got a valid ACK or DATAACK -
 769  * now create the new socket.
 770  *
 771  * This is the equivalent of TCP's tcp_v4_syn_recv_sock
 772  */
 773 struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
 774                                        struct request_sock *req,
 775                                        struct dst_entry *dst)
 776 {
 777         struct inet_request_sock *ireq;
 778         struct inet_sock *newinet;
 779         struct dccp_sock *newdp;
 780         struct sock *newsk;
 781
 782         if (sk_acceptq_is_full(sk))
 783                 goto exit_overflow;
 784
 785         if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
 786                 goto exit;
 787
 788         newsk = dccp_create_openreq_child(sk, req, skb);
 789         if (newsk == NULL)
 790                 goto exit;
 791
 792         sk_setup_caps(newsk, dst);
 793
 794         newdp              = dccp_sk(newsk);
 795         newinet            = inet_sk(newsk);
 796         ireq               = inet_rsk(req);
 797         newinet->daddr     = ireq->rmt_addr;
 798         newinet->rcv_saddr = ireq->loc_addr;
 799         newinet->saddr     = ireq->loc_addr;
 800         newinet->opt       = ireq->opt;
 801         ireq->opt          = NULL;
 802         newinet->mc_index  = inet_iif(skb);
 803         newinet->mc_ttl    = skb->nh.iph->ttl;
 804         newinet->id        = jiffies;
 805
 806         dccp_sync_mss(newsk, dst_mtu(dst));
 807
 808         __inet_hash(&dccp_hashinfo, newsk, 0);
 809         __inet_inherit_port(&dccp_hashinfo, sk, newsk);
 810
 811         return newsk;
 812
 813 exit_overflow:
 814         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
 815 exit:
 816         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
 817         dst_release(dst);
 818         return NULL;
 819 }
 820
 821 static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
 822 {
 823         const struct dccp_hdr *dh = dccp_hdr(skb);
 824         const struct iphdr *iph = skb->nh.iph;
 825         struct sock *nsk;
 826         struct request_sock **prev;
 827         /* Find possible connection requests. */
 828         struct request_sock *req = inet_csk_search_req(sk, &prev,
 829                                                        dh->dccph_sport,
 830                                                        iph->saddr, iph->daddr);
 831         if (req != NULL)
 832                 return dccp_check_req(sk, skb, req, prev);
 833
 834         nsk = __inet_lookup_established(&dccp_hashinfo,
 835                                         iph->saddr, dh->dccph_sport,
 836                                         iph->daddr, ntohs(dh->dccph_dport),
 837                                         inet_iif(skb));
 838         if (nsk != NULL) {
 839                 if (nsk->sk_state != DCCP_TIME_WAIT) {
 840                         bh_lock_sock(nsk);
 841                         return nsk;
 842                 }
 843                 inet_twsk_put((struct inet_timewait_sock *)nsk);
 844                 return NULL;
 845         }
 846
 847         return sk;
 848 }
 849
 850 int dccp_v4_checksum(const struct sk_buff *skb, const u32 saddr,
 851                      const u32 daddr)
 852 {
 853         const struct dccp_hdr* dh = dccp_hdr(skb);
 854         int checksum_len;
 855         u32 tmp;
 856
 857         if (dh->dccph_cscov == 0)
 858                 checksum_len = skb->len;
 859         else {
 860                 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
 861                 checksum_len = checksum_len < skb->len ? checksum_len :
 862                                                          skb->len;
 863         }
 864
 865         tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
 866         return csum_tcpudp_magic(saddr, daddr, checksum_len,
 867                                  IPPROTO_DCCP, tmp);
 868 }
 869
 870 static int dccp_v4_verify_checksum(struct sk_buff *skb,
 871                                    const u32 saddr, const u32 daddr)
 872 {
 873         struct dccp_hdr *dh = dccp_hdr(skb);
 874         int checksum_len;
 875         u32 tmp;
 876
 877         if (dh->dccph_cscov == 0)
 878                 checksum_len = skb->len;
 879         else {
 880                 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
 881                 checksum_len = checksum_len < skb->len ? checksum_len :
 882                                                          skb->len;
 883         }
 884         tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
 885         return csum_tcpudp_magic(saddr, daddr, checksum_len,
 886                                  IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
 887 }
 888
 889 static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
 890                                            struct sk_buff *skb)
 891 {
 892         struct rtable *rt;
 893         struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif,
 894                             .nl_u = { .ip4_u =
 895                                       { .daddr = skb->nh.iph->saddr,
 896                                         .saddr = skb->nh.iph->daddr,
 897                                         .tos = RT_CONN_FLAGS(sk) } },
 898                             .proto = sk->sk_protocol,
 899                             .uli_u = { .ports =
 900                                        { .sport = dccp_hdr(skb)->dccph_dport,
 901                                          .dport = dccp_hdr(skb)->dccph_sport }
 902                                      }
 903                           };
 904
 905         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 906                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
 907                 return NULL;
 908         }
 909
 910         return &rt->u.dst;
 911 }
 912
 913 static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
 914 {
 915         int err;
 916         struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
 917         const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
 918                                        sizeof(struct dccp_hdr_ext) +
 919                                        sizeof(struct dccp_hdr_reset);
 920         struct sk_buff *skb;
 921         struct dst_entry *dst;
 922         u64 seqno;
 923
 924         /* Never send a reset in response to a reset. */
 925         if (rxdh->dccph_type == DCCP_PKT_RESET)
 926                 return;
 927
 928         if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
 929                 return;
 930
 931         dst = dccp_v4_route_skb(dccp_ctl_socket->sk, rxskb);
 932         if (dst == NULL)
 933                 return;
 934
 935         skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC);
 936         if (skb == NULL)
 937                 goto out;
 938
 939         /* Reserve space for headers. */
 940         skb_reserve(skb, MAX_DCCP_HEADER);
 941         skb->dst = dst_clone(dst);
 942
 943         skb->h.raw = skb_push(skb, dccp_hdr_reset_len);
 944         dh = dccp_hdr(skb);
 945         memset(dh, 0, dccp_hdr_reset_len);
 946
 947         /* Build DCCP header and checksum it. */
 948         dh->dccph_type     = DCCP_PKT_RESET;
 949         dh->dccph_sport    = rxdh->dccph_dport;
 950         dh->dccph_dport    = rxdh->dccph_sport;
 951         dh->dccph_doff     = dccp_hdr_reset_len / 4;
 952         dh->dccph_x        = 1;
 953         dccp_hdr_reset(skb)->dccph_reset_code =
 954                                 DCCP_SKB_CB(rxskb)->dccpd_reset_code;
 955
 956         /* See "8.3.1. Abnormal Termination" in draft-ietf-dccp-spec-11 */
 957         seqno = 0;
 958         if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
 959                 dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
 960
 961         dccp_hdr_set_seq(dh, seqno);
 962         dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
 963                          DCCP_SKB_CB(rxskb)->dccpd_seq);
 964
 965         dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
 966                                               rxskb->nh.iph->daddr);
 967
 968         bh_lock_sock(dccp_ctl_socket->sk);
 969         err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk,
 970                                     rxskb->nh.iph->daddr,
 971                                     rxskb->nh.iph->saddr, NULL);
 972         bh_unlock_sock(dccp_ctl_socket->sk);
 973
 974         if (err == NET_XMIT_CN || err == 0) {
 975                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
 976                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
 977         }
 978 out:
 979          dst_release(dst);
 980 }
 981
 982 int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 983 {
 984         struct dccp_hdr *dh = dccp_hdr(skb);
 985
 986         if (sk->sk_state == DCCP_OPEN) { /* Fast path */
 987                 if (dccp_rcv_established(sk, skb, dh, skb->len))
 988                         goto reset;
 989                 return 0;
 990         }
 991
 992         /*
 993          *  Step 3: Process LISTEN state
 994          *     If S.state == LISTEN,
 995          *        If P.type == Request or P contains a valid Init Cookie
 996          *              option,
 997          *           * Must scan the packet's options to check for an Init
 998          *              Cookie.  Only the Init Cookie is processed here,
 999          *              however; other options are processed in Step 8.  This
1000          *              scan need only be performed if the endpoint uses Init
1001          *              Cookies *
1002          *           * Generate a new socket and switch to that socket *
1003          *           Set S := new socket for this port pair
1004          *           S.state = RESPOND
1005          *           Choose S.ISS (initial seqno) or set from Init Cookie
1006          *           Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
1007          *           Continue with S.state == RESPOND
1008          *           * A Response packet will be generated in Step 11 *
1009          *        Otherwise,
1010          *           Generate Reset(No Connection) unless P.type == Reset
1011          *           Drop packet and return
1012          *
1013          * NOTE: the check for the packet types is done in
1014          *       dccp_rcv_state_process
1015          */
1016         if (sk->sk_state == DCCP_LISTEN) {
1017                 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
1018
1019                 if (nsk == NULL)
1020                         goto discard;
1021
1022                 if (nsk != sk) {
1023                         if (dccp_child_process(sk, nsk, skb))
1024                                 goto reset;
1025                         return 0;
1026                 }
1027         }
1028
1029         if (dccp_rcv_state_process(sk, skb, dh, skb->len))
1030                 goto reset;
1031         return 0;
1032
1033 reset:
1034         dccp_v4_ctl_send_reset(skb);
1035 discard:
1036         kfree_skb(skb);
1037         return 0;
1038 }
1039
1040 static inline int dccp_invalid_packet(struct sk_buff *skb)
1041 {
1042         const struct dccp_hdr *dh;
1043
1044         if (skb->pkt_type != PACKET_HOST)
1045                 return 1;
1046
1047         if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
1048                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n");
1049                 return 1;
1050         }
1051
1052         dh = dccp_hdr(skb);
1053
1054         /* If the packet type is not understood, drop packet and return */
1055         if (dh->dccph_type >= DCCP_PKT_INVALID) {
1056                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n");
1057                 return 1;
1058         }
1059
1060         /*
1061          * If P.Data Offset is too small for packet type, or too large for
1062          * packet, drop packet and return
1063          */
1064         if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
1065                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
1066                                             "too small 1\n",
1067                                dh->dccph_doff);
1068                 return 1;
1069         }
1070
1071         if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
1072                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
1073                                             "too small 2\n",
1074                                dh->dccph_doff);
1075                 return 1;
1076         }
1077
1078         dh = dccp_hdr(skb);
1079
1080         /*
1081          * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
1082          * has short sequence numbers), drop packet and return
1083          */
1084         if (dh->dccph_x == 0 &&
1085             dh->dccph_type != DCCP_PKT_DATA &&
1086             dh->dccph_type != DCCP_PKT_ACK &&
1087             dh->dccph_type != DCCP_PKT_DATAACK) {
1088                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack "
1089                                             "nor DataAck and P.X == 0\n",
1090                                dccp_packet_name(dh->dccph_type));
1091                 return 1;
1092         }
1093
1094         /* If the header checksum is incorrect, drop packet and return */
1095         if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
1096                                     skb->nh.iph->daddr) < 0) {
1097                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: header checksum is "
1098                                             "incorrect\n");
1099                 return 1;
1100         }
1101
1102         return 0;
1103 }
1104
1105 /* this is called when real data arrives */
1106 int dccp_v4_rcv(struct sk_buff *skb)
1107 {
1108         const struct dccp_hdr *dh;
1109         struct sock *sk;
1110         int rc;
1111
1112         /* Step 1: Check header basics: */
1113
1114         if (dccp_invalid_packet(skb))
1115                 goto discard_it;
1116
1117         dh = dccp_hdr(skb);
1118
1119         DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(skb);
1120         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
1121
1122         dccp_pr_debug("%8.8s "
1123                       "src=%u.%u.%u.%u@%-5d "
1124                       "dst=%u.%u.%u.%u@%-5d seq=%llu",
1125                       dccp_packet_name(dh->dccph_type),
1126                       NIPQUAD(skb->nh.iph->saddr), ntohs(dh->dccph_sport),
1127                       NIPQUAD(skb->nh.iph->daddr), ntohs(dh->dccph_dport),
1128                       (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
1129
1130         if (dccp_packet_without_ack(skb)) {
1131                 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
1132                 dccp_pr_debug_cat("\n");
1133         } else {
1134                 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
1135                 dccp_pr_debug_cat(", ack=%llu\n",
1136                                   (unsigned long long)
1137                                   DCCP_SKB_CB(skb)->dccpd_ack_seq);
1138         }
1139
1140         /* Step 2:
1141          *      Look up flow ID in table and get corresponding socket */
1142         sk = __inet_lookup(&dccp_hashinfo,
1143                            skb->nh.iph->saddr, dh->dccph_sport,
1144                            skb->nh.iph->daddr, ntohs(dh->dccph_dport),
1145                            inet_iif(skb));
1146
1147         /*
1148          * Step 2:
1149          *      If no socket ...
1150          *              Generate Reset(No Connection) unless P.type == Reset
1151          *              Drop packet and return
1152          */
1153         if (sk == NULL) {
1154                 dccp_pr_debug("failed to look up flow ID in table and "
1155                               "get corresponding socket\n");
1156                 goto no_dccp_socket;
1157         }
1158
1159         /*
1160          * Step 2:
1161          *      ... or S.state == TIMEWAIT,
1162          *              Generate Reset(No Connection) unless P.type == Reset
1163          *              Drop packet and return
1164          */
1165
1166         if (sk->sk_state == DCCP_TIME_WAIT) {
1167                 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: "
1168                               "do_time_wait\n");
1169                 goto do_time_wait;
1170         }
1171
1172         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
1173                 dccp_pr_debug("xfrm4_policy_check failed\n");
1174                 goto discard_and_relse;
1175         }
1176
1177         if (sk_filter(sk, skb, 0)) {
1178                 dccp_pr_debug("sk_filter failed\n");
1179                 goto discard_and_relse;
1180         }
1181
1182         skb->dev = NULL;
1183
1184         bh_lock_sock(sk);
1185         rc = 0;
1186         if (!sock_owned_by_user(sk))
1187                 rc = dccp_v4_do_rcv(sk, skb);
1188         else
1189                 sk_add_backlog(sk, skb);
1190         bh_unlock_sock(sk);
1191
1192         sock_put(sk);
1193         return rc;
1194
1195 no_dccp_socket:
1196         if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1197                 goto discard_it;
1198         /*
1199          * Step 2:
1200          *              Generate Reset(No Connection) unless P.type == Reset
1201          *              Drop packet and return
1202          */
1203         if (dh->dccph_type != DCCP_PKT_RESET) {
1204                 DCCP_SKB_CB(skb)->dccpd_reset_code =
1205                                         DCCP_RESET_CODE_NO_CONNECTION;
1206                 dccp_v4_ctl_send_reset(skb);
1207         }
1208
1209 discard_it:
1210         /* Discard frame. */
1211         kfree_skb(skb);
1212         return 0;
1213
1214 discard_and_relse:
1215         sock_put(sk);
1216         goto discard_it;
1217
1218 do_time_wait:
1219         inet_twsk_put((struct inet_timewait_sock *)sk);
1220         goto no_dccp_socket;
1221 }
1222
1223 static int dccp_v4_init_sock(struct sock *sk)
1224 {
1225         struct dccp_sock *dp = dccp_sk(sk);
1226         static int dccp_ctl_socket_init = 1;
1227
1228         dccp_options_init(&dp->dccps_options);
1229         do_gettimeofday(&dp->dccps_epoch);
1230
1231         if (dp->dccps_options.dccpo_send_ack_vector) {
1232                 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(DCCP_MAX_ACKVEC_LEN,
1233                                                            GFP_KERNEL);
1234                 if (dp->dccps_hc_rx_ackvec == NULL)
1235                         return -ENOMEM;
1236         }
1237
1238         /*
1239          * FIXME: We're hardcoding the CCID, and doing this at this point makes
1240          * the listening (master) sock get CCID control blocks, which is not
1241          * necessary, but for now, to not mess with the test userspace apps,
1242          * lets leave it here, later the real solution is to do this in a
1243          * setsockopt(CCIDs-I-want/accept). -acme
1244          */
1245         if (likely(!dccp_ctl_socket_init)) {
1246                 dp->dccps_hc_rx_ccid = ccid_init(dp->dccps_options.dccpo_rx_ccid,
1247                                                  sk);
1248                 dp->dccps_hc_tx_ccid = ccid_init(dp->dccps_options.dccpo_tx_ccid,
1249                                                  sk);
1250                 if (dp->dccps_hc_rx_ccid == NULL ||
1251                     dp->dccps_hc_tx_ccid == NULL) {
1252                         ccid_exit(dp->dccps_hc_rx_ccid, sk);
1253                         ccid_exit(dp->dccps_hc_tx_ccid, sk);
1254                         if (dp->dccps_options.dccpo_send_ack_vector) {
1255                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
1256                                 dp->dccps_hc_rx_ackvec = NULL;
1257                         }
1258                         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1259                         return -ENOMEM;
1260                 }
1261         } else
1262                 dccp_ctl_socket_init = 0;
1263
1264         dccp_init_xmit_timers(sk);
1265         inet_csk(sk)->icsk_rto = DCCP_TIMEOUT_INIT;
1266         sk->sk_state = DCCP_CLOSED;
1267         sk->sk_write_space = dccp_write_space;
1268         dp->dccps_mss_cache = 536;
1269         dp->dccps_role = DCCP_ROLE_UNDEFINED;
1270         dp->dccps_service = DCCP_SERVICE_INVALID_VALUE;
1271
1272         return 0;
1273 }
1274
1275 static int dccp_v4_destroy_sock(struct sock *sk)
1276 {
1277         struct dccp_sock *dp = dccp_sk(sk);
1278
1279         /*
1280          * DCCP doesn't use sk_qrite_queue, just sk_send_head
1281          * for retransmissions
1282          */
1283         if (sk->sk_send_head != NULL) {
1284                 kfree_skb(sk->sk_send_head);
1285                 sk->sk_send_head = NULL;
1286         }
1287
1288         /* Clean up a referenced DCCP bind bucket. */
1289         if (inet_csk(sk)->icsk_bind_hash != NULL)
1290                 inet_put_port(&dccp_hashinfo, sk);
1291
1292         if (dp->dccps_service_list != NULL) {
1293                 kfree(dp->dccps_service_list);
1294                 dp->dccps_service_list = NULL;
1295         }
1296
1297         ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
1298         ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
1299         if (dp->dccps_options.dccpo_send_ack_vector) {
1300                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
1301                 dp->dccps_hc_rx_ackvec = NULL;
1302         }
1303         ccid_exit(dp->dccps_hc_rx_ccid, sk);
1304         ccid_exit(dp->dccps_hc_tx_ccid, sk);
1305         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1306
1307         return 0;
1308 }
1309
1310 static void dccp_v4_reqsk_destructor(struct request_sock *req)
1311 {
1312         kfree(inet_rsk(req)->opt);
1313 }
1314
1315 static struct request_sock_ops dccp_request_sock_ops = {
1316         .family         = PF_INET,
1317         .obj_size       = sizeof(struct dccp_request_sock),
1318         .rtx_syn_ack    = dccp_v4_send_response,
1319         .send_ack       = dccp_v4_reqsk_send_ack,
1320         .destructor     = dccp_v4_reqsk_destructor,
1321         .send_reset     = dccp_v4_ctl_send_reset,
1322 };
1323
1324 struct proto dccp_v4_prot = {
1325         .name                   = "DCCP",
1326         .owner                  = THIS_MODULE,
1327         .close                  = dccp_close,
1328         .connect                = dccp_v4_connect,
1329         .disconnect             = dccp_disconnect,
1330         .ioctl                  = dccp_ioctl,
1331         .init                   = dccp_v4_init_sock,
1332         .setsockopt             = dccp_setsockopt,
1333         .getsockopt             = dccp_getsockopt,
1334         .sendmsg                = dccp_sendmsg,
1335         .recvmsg                = dccp_recvmsg,
1336         .backlog_rcv            = dccp_v4_do_rcv,
1337         .hash                   = dccp_v4_hash,
1338         .unhash                 = dccp_v4_unhash,
1339         .accept                 = inet_csk_accept,
1340         .get_port               = dccp_v4_get_port,
1341         .shutdown               = dccp_shutdown,
1342         .destroy                = dccp_v4_destroy_sock,
1343         .orphan_count           = &dccp_orphan_count,
1344         .max_header             = MAX_DCCP_HEADER,
1345         .obj_size               = sizeof(struct dccp_sock),
1346         .rsk_prot               = &dccp_request_sock_ops,
1347         .twsk_obj_size          = sizeof(struct inet_timewait_sock),
1348 };