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   1 /*
   2  *  net/dccp/proto.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 modify it
   8  *      under the terms of the GNU General Public License version 2 as
   9  *      published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/dccp.h>
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/in.h>
  21 #include <linux/if_arp.h>
  22 #include <linux/init.h>
  23 #include <linux/random.h>
  24 #include <net/checksum.h>
  25
  26 #include <net/inet_common.h>
  27 #include <net/ip.h>
  28 #include <net/protocol.h>
  29 #include <net/sock.h>
  30 #include <net/xfrm.h>
  31
  32 #include <asm/semaphore.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/timer.h>
  35 #include <linux/delay.h>
  36 #include <linux/poll.h>
  37 #include <linux/dccp.h>
  38
  39 #include "ccid.h"
  40 #include "dccp.h"
  41
  42 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics);
  43
  44 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
  45
  46 static struct net_protocol dccp_protocol = {
  47         .handler        = dccp_v4_rcv,
  48         .err_handler    = dccp_v4_err,
  49 };
  50
  51 const char *dccp_packet_name(const int type)
  52 {
  53         static const char *dccp_packet_names[] = {
  54                 [DCCP_PKT_REQUEST]  = "REQUEST",
  55                 [DCCP_PKT_RESPONSE] = "RESPONSE",
  56                 [DCCP_PKT_DATA]     = "DATA",
  57                 [DCCP_PKT_ACK]      = "ACK",
  58                 [DCCP_PKT_DATAACK]  = "DATAACK",
  59                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
  60                 [DCCP_PKT_CLOSE]    = "CLOSE",
  61                 [DCCP_PKT_RESET]    = "RESET",
  62                 [DCCP_PKT_SYNC]     = "SYNC",
  63                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
  64         };
  65
  66         if (type >= DCCP_NR_PKT_TYPES)
  67                 return "INVALID";
  68         else
  69                 return dccp_packet_names[type];
  70 }
  71
  72 EXPORT_SYMBOL_GPL(dccp_packet_name);
  73
  74 const char *dccp_state_name(const int state)
  75 {
  76         static char *dccp_state_names[] = {
  77         [DCCP_OPEN]       = "OPEN",
  78         [DCCP_REQUESTING] = "REQUESTING",
  79         [DCCP_PARTOPEN]   = "PARTOPEN",
  80         [DCCP_LISTEN]     = "LISTEN",
  81         [DCCP_RESPOND]    = "RESPOND",
  82         [DCCP_CLOSING]    = "CLOSING",
  83         [DCCP_TIME_WAIT]  = "TIME_WAIT",
  84         [DCCP_CLOSED]     = "CLOSED",
  85         };
  86
  87         if (state >= DCCP_MAX_STATES)
  88                 return "INVALID STATE!";
  89         else
  90                 return dccp_state_names[state];
  91 }
  92
  93 EXPORT_SYMBOL_GPL(dccp_state_name);
  94
  95 static inline int dccp_listen_start(struct sock *sk)
  96 {
  97         dccp_sk(sk)->dccps_role = DCCP_ROLE_LISTEN;
  98         return inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
  99 }
 100
 101 int dccp_disconnect(struct sock *sk, int flags)
 102 {
 103         struct inet_connection_sock *icsk = inet_csk(sk);
 104         struct inet_sock *inet = inet_sk(sk);
 105         int err = 0;
 106         const int old_state = sk->sk_state;
 107
 108         if (old_state != DCCP_CLOSED)
 109                 dccp_set_state(sk, DCCP_CLOSED);
 110
 111         /* ABORT function of RFC793 */
 112         if (old_state == DCCP_LISTEN) {
 113                 inet_csk_listen_stop(sk);
 114         /* FIXME: do the active reset thing */
 115         } else if (old_state == DCCP_REQUESTING)
 116                 sk->sk_err = ECONNRESET;
 117
 118         dccp_clear_xmit_timers(sk);
 119         __skb_queue_purge(&sk->sk_receive_queue);
 120         if (sk->sk_send_head != NULL) {
 121                 __kfree_skb(sk->sk_send_head);
 122                 sk->sk_send_head = NULL;
 123         }
 124
 125         inet->dport = 0;
 126
 127         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 128                 inet_reset_saddr(sk);
 129
 130         sk->sk_shutdown = 0;
 131         sock_reset_flag(sk, SOCK_DONE);
 132
 133         icsk->icsk_backoff = 0;
 134         inet_csk_delack_init(sk);
 135         __sk_dst_reset(sk);
 136
 137         BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
 138
 139         sk->sk_error_report(sk);
 140         return err;
 141 }
 142
 143 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 144 {
 145         dccp_pr_debug("entry\n");
 146         return -ENOIOCTLCMD;
 147 }
 148
 149 int dccp_setsockopt(struct sock *sk, int level, int optname,
 150                     char __user *optval, int optlen)
 151 {
 152         dccp_pr_debug("entry\n");
 153
 154         if (level != SOL_DCCP)
 155                 return ip_setsockopt(sk, level, optname, optval, optlen);
 156
 157         return -EOPNOTSUPP;
 158 }
 159
 160 int dccp_getsockopt(struct sock *sk, int level, int optname,
 161                     char __user *optval, int __user *optlen)
 162 {
 163         dccp_pr_debug("entry\n");
 164
 165         if (level != SOL_DCCP)
 166                 return ip_getsockopt(sk, level, optname, optval, optlen);
 167
 168         return -EOPNOTSUPP;
 169 }
 170
 171 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 172                  size_t len)
 173 {
 174         const struct dccp_sock *dp = dccp_sk(sk);
 175         const int flags = msg->msg_flags;
 176         const int noblock = flags & MSG_DONTWAIT;
 177         struct sk_buff *skb;
 178         int rc, size;
 179         long timeo;
 180
 181         if (len > dp->dccps_mss_cache)
 182                 return -EMSGSIZE;
 183
 184         lock_sock(sk);
 185         timeo = sock_sndtimeo(sk, noblock);
 186
 187         /*
 188          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 189          * so that the trick in dccp_rcv_request_sent_state_process.
 190          */
 191         /* Wait for a connection to finish. */
 192         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
 193                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 194                         goto out_release;
 195
 196         size = sk->sk_prot->max_header + len;
 197         release_sock(sk);
 198         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 199         lock_sock(sk);
 200         if (skb == NULL)
 201                 goto out_release;
 202
 203         skb_reserve(skb, sk->sk_prot->max_header);
 204         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 205         if (rc != 0)
 206                 goto out_discard;
 207
 208         rc = dccp_write_xmit(sk, skb, len);
 209         /*
 210          * XXX we don't use sk_write_queue, so just discard the packet.
 211          *     Current plan however is to _use_ sk_write_queue with
 212          *     an algorith similar to tcp_sendmsg, where the main difference
 213          *     is that in DCCP we have to respect packet boundaries, so
 214          *     no coalescing of skbs.
 215          *
 216          *     This bug was _quickly_ found & fixed by just looking at an OSTRA
 217          *     generated callgraph 8) -acme
 218          */
 219         if (rc != 0)
 220                 goto out_discard;
 221 out_release:
 222         release_sock(sk);
 223         return rc ? : len;
 224 out_discard:
 225         kfree_skb(skb);
 226         goto out_release;
 227 }
 228
 229 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 230                  size_t len, int nonblock, int flags, int *addr_len)
 231 {
 232         const struct dccp_hdr *dh;
 233         long timeo;
 234
 235         lock_sock(sk);
 236
 237         if (sk->sk_state == DCCP_LISTEN) {
 238                 len = -ENOTCONN;
 239                 goto out;
 240         }
 241
 242         timeo = sock_rcvtimeo(sk, nonblock);
 243
 244         do {
 245                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 246
 247                 if (skb == NULL)
 248                         goto verify_sock_status;
 249
 250                 dh = dccp_hdr(skb);
 251
 252                 if (dh->dccph_type == DCCP_PKT_DATA ||
 253                     dh->dccph_type == DCCP_PKT_DATAACK)
 254                         goto found_ok_skb;
 255
 256                 if (dh->dccph_type == DCCP_PKT_RESET ||
 257                     dh->dccph_type == DCCP_PKT_CLOSE) {
 258                         dccp_pr_debug("found fin ok!\n");
 259                         len = 0;
 260                         goto found_fin_ok;
 261                 }
 262                 dccp_pr_debug("packet_type=%s\n",
 263                               dccp_packet_name(dh->dccph_type));
 264                 sk_eat_skb(sk, skb);
 265 verify_sock_status:
 266                 if (sock_flag(sk, SOCK_DONE)) {
 267                         len = 0;
 268                         break;
 269                 }
 270
 271                 if (sk->sk_err) {
 272                         len = sock_error(sk);
 273                         break;
 274                 }
 275
 276                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 277                         len = 0;
 278                         break;
 279                 }
 280
 281                 if (sk->sk_state == DCCP_CLOSED) {
 282                         if (!sock_flag(sk, SOCK_DONE)) {
 283                                 /* This occurs when user tries to read
 284                                  * from never connected socket.
 285                                  */
 286                                 len = -ENOTCONN;
 287                                 break;
 288                         }
 289                         len = 0;
 290                         break;
 291                 }
 292
 293                 if (!timeo) {
 294                         len = -EAGAIN;
 295                         break;
 296                 }
 297
 298                 if (signal_pending(current)) {
 299                         len = sock_intr_errno(timeo);
 300                         break;
 301                 }
 302
 303                 sk_wait_data(sk, &timeo);
 304                 continue;
 305         found_ok_skb:
 306                 if (len > skb->len)
 307                         len = skb->len;
 308                 else if (len < skb->len)
 309                         msg->msg_flags |= MSG_TRUNC;
 310
 311                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 312                         /* Exception. Bailout! */
 313                         len = -EFAULT;
 314                         break;
 315                 }
 316         found_fin_ok:
 317                 if (!(flags & MSG_PEEK))
 318                         sk_eat_skb(sk, skb);
 319                 break;
 320         } while (1);
 321 out:
 322         release_sock(sk);
 323         return len;
 324 }
 325
 326 static int inet_dccp_listen(struct socket *sock, int backlog)
 327 {
 328         struct sock *sk = sock->sk;
 329         unsigned char old_state;
 330         int err;
 331
 332         lock_sock(sk);
 333
 334         err = -EINVAL;
 335         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 336                 goto out;
 337
 338         old_state = sk->sk_state;
 339         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 340                 goto out;
 341
 342         /* Really, if the socket is already in listen state
 343          * we can only allow the backlog to be adjusted.
 344          */
 345         if (old_state != DCCP_LISTEN) {
 346                 /*
 347                  * FIXME: here it probably should be sk->sk_prot->listen_start
 348                  * see tcp_listen_start
 349                  */
 350                 err = dccp_listen_start(sk);
 351                 if (err)
 352                         goto out;
 353         }
 354         sk->sk_max_ack_backlog = backlog;
 355         err = 0;
 356
 357 out:
 358         release_sock(sk);
 359         return err;
 360 }
 361
 362 static const unsigned char dccp_new_state[] = {
 363         /* current state:   new state:      action:     */
 364         [0]               = DCCP_CLOSED,
 365         [DCCP_OPEN]       = DCCP_CLOSING | DCCP_ACTION_FIN,
 366         [DCCP_REQUESTING] = DCCP_CLOSED,
 367         [DCCP_PARTOPEN]   = DCCP_CLOSING | DCCP_ACTION_FIN,
 368         [DCCP_LISTEN]     = DCCP_CLOSED,
 369         [DCCP_RESPOND]    = DCCP_CLOSED,
 370         [DCCP_CLOSING]    = DCCP_CLOSED,
 371         [DCCP_TIME_WAIT]  = DCCP_CLOSED,
 372         [DCCP_CLOSED]     = DCCP_CLOSED,
 373 };
 374
 375 static int dccp_close_state(struct sock *sk)
 376 {
 377         const int next = dccp_new_state[sk->sk_state];
 378         const int ns = next & DCCP_STATE_MASK;
 379
 380         if (ns != sk->sk_state)
 381                 dccp_set_state(sk, ns);
 382
 383         return next & DCCP_ACTION_FIN;
 384 }
 385
 386 void dccp_close(struct sock *sk, long timeout)
 387 {
 388         struct sk_buff *skb;
 389
 390         lock_sock(sk);
 391
 392         sk->sk_shutdown = SHUTDOWN_MASK;
 393
 394         if (sk->sk_state == DCCP_LISTEN) {
 395                 dccp_set_state(sk, DCCP_CLOSED);
 396
 397                 /* Special case. */
 398                 inet_csk_listen_stop(sk);
 399
 400                 goto adjudge_to_death;
 401         }
 402
 403         /*
 404          * We need to flush the recv. buffs.  We do this only on the
 405          * descriptor close, not protocol-sourced closes, because the
 406           *reader process may not have drained the data yet!
 407          */
 408         /* FIXME: check for unread data */
 409         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 410                 __kfree_skb(skb);
 411         }
 412
 413         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 414                 /* Check zero linger _after_ checking for unread data. */
 415                 sk->sk_prot->disconnect(sk, 0);
 416         } else if (dccp_close_state(sk)) {
 417                 dccp_send_close(sk, 1);
 418         }
 419
 420         sk_stream_wait_close(sk, timeout);
 421
 422 adjudge_to_death:
 423         /*
 424          * It is the last release_sock in its life. It will remove backlog.
 425          */
 426         release_sock(sk);
 427         /*
 428          * Now socket is owned by kernel and we acquire BH lock
 429          * to finish close. No need to check for user refs.
 430          */
 431         local_bh_disable();
 432         bh_lock_sock(sk);
 433         BUG_TRAP(!sock_owned_by_user(sk));
 434
 435         sock_hold(sk);
 436         sock_orphan(sk);
 437
 438         /*
 439          * The last release_sock may have processed the CLOSE or RESET
 440          * packet moving sock to CLOSED state, if not we have to fire
 441          * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
 442          * in draft-ietf-dccp-spec-11. -acme
 443          */
 444         if (sk->sk_state == DCCP_CLOSING) {
 445                 /* FIXME: should start at 2 * RTT */
 446                 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
 447                 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 448                                           inet_csk(sk)->icsk_rto,
 449                                           DCCP_RTO_MAX);
 450 #if 0
 451                 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
 452                 dccp_set_state(sk, DCCP_CLOSED);
 453 #endif
 454         }
 455
 456         atomic_inc(sk->sk_prot->orphan_count);
 457         if (sk->sk_state == DCCP_CLOSED)
 458                 inet_csk_destroy_sock(sk);
 459
 460         /* Otherwise, socket is reprieved until protocol close. */
 461
 462         bh_unlock_sock(sk);
 463         local_bh_enable();
 464         sock_put(sk);
 465 }
 466
 467 void dccp_shutdown(struct sock *sk, int how)
 468 {
 469         dccp_pr_debug("entry\n");
 470 }
 471
 472 static struct proto_ops inet_dccp_ops = {
 473         .family         = PF_INET,
 474         .owner          = THIS_MODULE,
 475         .release        = inet_release,
 476         .bind           = inet_bind,
 477         .connect        = inet_stream_connect,
 478         .socketpair     = sock_no_socketpair,
 479         .accept         = inet_accept,
 480         .getname        = inet_getname,
 481         .poll           = sock_no_poll,
 482         .ioctl          = inet_ioctl,
 483         /* FIXME: work on inet_listen to rename it to sock_common_listen */
 484         .listen         = inet_dccp_listen,
 485         .shutdown       = inet_shutdown,
 486         .setsockopt     = sock_common_setsockopt,
 487         .getsockopt     = sock_common_getsockopt,
 488         .sendmsg        = inet_sendmsg,
 489         .recvmsg        = sock_common_recvmsg,
 490         .mmap           = sock_no_mmap,
 491         .sendpage       = sock_no_sendpage,
 492 };
 493
 494 extern struct net_proto_family inet_family_ops;
 495
 496 static struct inet_protosw dccp_v4_protosw = {
 497         .type           = SOCK_DCCP,
 498         .protocol       = IPPROTO_DCCP,
 499         .prot           = &dccp_v4_prot,
 500         .ops            = &inet_dccp_ops,
 501         .capability     = -1,
 502         .no_check       = 0,
 503         .flags          = 0,
 504 };
 505
 506 /*
 507  * This is the global socket data structure used for responding to
 508  * the Out-of-the-blue (OOTB) packets. A control sock will be created
 509  * for this socket at the initialization time.
 510  */
 511 struct socket *dccp_ctl_socket;
 512
 513 static char dccp_ctl_socket_err_msg[] __initdata =
 514         KERN_ERR "DCCP: Failed to create the control socket.\n";
 515
 516 static int __init dccp_ctl_sock_init(void)
 517 {
 518         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
 519                                   &dccp_ctl_socket);
 520         if (rc < 0)
 521                 printk(dccp_ctl_socket_err_msg);
 522         else {
 523                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
 524                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
 525
 526                 /* Unhash it so that IP input processing does not even
 527                  * see it, we do not wish this socket to see incoming
 528                  * packets.
 529                  */
 530                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
 531         }
 532
 533         return rc;
 534 }
 535
 536 #ifdef CONFIG_IP_DCCP_UNLOAD_HACK
 537 void dccp_ctl_sock_exit(void)
 538 {
 539         if (dccp_ctl_socket != NULL) {
 540                 sock_release(dccp_ctl_socket);
 541                 dccp_ctl_socket = NULL;
 542         }
 543 }
 544
 545 EXPORT_SYMBOL_GPL(dccp_ctl_sock_exit);
 546 #endif
 547
 548 static int __init init_dccp_v4_mibs(void)
 549 {
 550         int rc = -ENOMEM;
 551
 552         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 553         if (dccp_statistics[0] == NULL)
 554                 goto out;
 555
 556         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 557         if (dccp_statistics[1] == NULL)
 558                 goto out_free_one;
 559
 560         rc = 0;
 561 out:
 562         return rc;
 563 out_free_one:
 564         free_percpu(dccp_statistics[0]);
 565         dccp_statistics[0] = NULL;
 566         goto out;
 567
 568 }
 569
 570 static int thash_entries;
 571 module_param(thash_entries, int, 0444);
 572 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 573
 574 #ifdef CONFIG_IP_DCCP_DEBUG
 575 int dccp_debug;
 576 module_param(dccp_debug, int, 0444);
 577 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 578 #endif
 579
 580 static int __init dccp_init(void)
 581 {
 582         unsigned long goal;
 583         int ehash_order, bhash_order, i;
 584         int rc = proto_register(&dccp_v4_prot, 1);
 585
 586         if (rc)
 587                 goto out;
 588
 589         dccp_hashinfo.bind_bucket_cachep =
 590                 kmem_cache_create("dccp_bind_bucket",
 591                                   sizeof(struct inet_bind_bucket), 0,
 592                                   SLAB_HWCACHE_ALIGN, NULL, NULL);
 593         if (!dccp_hashinfo.bind_bucket_cachep)
 594                 goto out_proto_unregister;
 595
 596         /*
 597          * Size and allocate the main established and bind bucket
 598          * hash tables.
 599          *
 600          * The methodology is similar to that of the buffer cache.
 601          */
 602         if (num_physpages >= (128 * 1024))
 603                 goal = num_physpages >> (21 - PAGE_SHIFT);
 604         else
 605                 goal = num_physpages >> (23 - PAGE_SHIFT);
 606
 607         if (thash_entries)
 608                 goal = (thash_entries *
 609                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
 610         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
 611                 ;
 612         do {
 613                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
 614                                         sizeof(struct inet_ehash_bucket);
 615                 dccp_hashinfo.ehash_size >>= 1;
 616                 while (dccp_hashinfo.ehash_size &
 617                        (dccp_hashinfo.ehash_size - 1))
 618                         dccp_hashinfo.ehash_size--;
 619                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
 620                         __get_free_pages(GFP_ATOMIC, ehash_order);
 621         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 622
 623         if (!dccp_hashinfo.ehash) {
 624                 printk(KERN_CRIT "Failed to allocate DCCP "
 625                                  "established hash table\n");
 626                 goto out_free_bind_bucket_cachep;
 627         }
 628
 629         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
 630                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
 631                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
 632         }
 633
 634         bhash_order = ehash_order;
 635
 636         do {
 637                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
 638                                         sizeof(struct inet_bind_hashbucket);
 639                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
 640                     bhash_order > 0)
 641                         continue;
 642                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
 643                         __get_free_pages(GFP_ATOMIC, bhash_order);
 644         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 645
 646         if (!dccp_hashinfo.bhash) {
 647                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
 648                 goto out_free_dccp_ehash;
 649         }
 650
 651         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 652                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 653                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
 654         }
 655
 656         if (init_dccp_v4_mibs())
 657                 goto out_free_dccp_bhash;
 658
 659         rc = -EAGAIN;
 660         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
 661                 goto out_free_dccp_v4_mibs;
 662
 663         inet_register_protosw(&dccp_v4_protosw);
 664
 665         rc = dccp_ctl_sock_init();
 666         if (rc)
 667                 goto out_unregister_protosw;
 668 out:
 669         return rc;
 670 out_unregister_protosw:
 671         inet_unregister_protosw(&dccp_v4_protosw);
 672         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
 673 out_free_dccp_v4_mibs:
 674         free_percpu(dccp_statistics[0]);
 675         free_percpu(dccp_statistics[1]);
 676         dccp_statistics[0] = dccp_statistics[1] = NULL;
 677 out_free_dccp_bhash:
 678         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 679         dccp_hashinfo.bhash = NULL;
 680 out_free_dccp_ehash:
 681         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 682         dccp_hashinfo.ehash = NULL;
 683 out_free_bind_bucket_cachep:
 684         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 685         dccp_hashinfo.bind_bucket_cachep = NULL;
 686 out_proto_unregister:
 687         proto_unregister(&dccp_v4_prot);
 688         goto out;
 689 }
 690
 691 static const char dccp_del_proto_err_msg[] __exitdata =
 692         KERN_ERR "can't remove dccp net_protocol\n";
 693
 694 static void __exit dccp_fini(void)
 695 {
 696         inet_unregister_protosw(&dccp_v4_protosw);
 697
 698         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
 699                 printk(dccp_del_proto_err_msg);
 700
 701         free_percpu(dccp_statistics[0]);
 702         free_percpu(dccp_statistics[1]);
 703         free_pages((unsigned long)dccp_hashinfo.bhash,
 704                    get_order(dccp_hashinfo.bhash_size *
 705                              sizeof(struct inet_bind_hashbucket)));
 706         free_pages((unsigned long)dccp_hashinfo.ehash,
 707                    get_order(dccp_hashinfo.ehash_size *
 708                              sizeof(struct inet_ehash_bucket)));
 709         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 710         proto_unregister(&dccp_v4_prot);
 711 }
 712
 713 module_init(dccp_init);
 714 module_exit(dccp_fini);
 715
 716 /*
 717  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
 718  * values directly, Also cover the case where the protocol is not specified,
 719  * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
 720  */
 721 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
 722 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
 723 MODULE_LICENSE("GPL");
 724 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
 725 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");