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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 out_release:
 210         release_sock(sk);
 211         return rc ? : len;
 212 out_discard:
 213         kfree_skb(skb);
 214         goto out_release;
 215 }
 216
 217 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 218                  size_t len, int nonblock, int flags, int *addr_len)
 219 {
 220         const struct dccp_hdr *dh;
 221         long timeo;
 222
 223         lock_sock(sk);
 224
 225         if (sk->sk_state == DCCP_LISTEN) {
 226                 len = -ENOTCONN;
 227                 goto out;
 228         }
 229
 230         timeo = sock_rcvtimeo(sk, nonblock);
 231
 232         do {
 233                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 234
 235                 if (skb == NULL)
 236                         goto verify_sock_status;
 237
 238                 dh = dccp_hdr(skb);
 239
 240                 if (dh->dccph_type == DCCP_PKT_DATA ||
 241                     dh->dccph_type == DCCP_PKT_DATAACK)
 242                         goto found_ok_skb;
 243
 244                 if (dh->dccph_type == DCCP_PKT_RESET ||
 245                     dh->dccph_type == DCCP_PKT_CLOSE) {
 246                         dccp_pr_debug("found fin ok!\n");
 247                         len = 0;
 248                         goto found_fin_ok;
 249                 }
 250                 dccp_pr_debug("packet_type=%s\n",
 251                               dccp_packet_name(dh->dccph_type));
 252                 sk_eat_skb(sk, skb);
 253 verify_sock_status:
 254                 if (sock_flag(sk, SOCK_DONE)) {
 255                         len = 0;
 256                         break;
 257                 }
 258
 259                 if (sk->sk_err) {
 260                         len = sock_error(sk);
 261                         break;
 262                 }
 263
 264                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 265                         len = 0;
 266                         break;
 267                 }
 268
 269                 if (sk->sk_state == DCCP_CLOSED) {
 270                         if (!sock_flag(sk, SOCK_DONE)) {
 271                                 /* This occurs when user tries to read
 272                                  * from never connected socket.
 273                                  */
 274                                 len = -ENOTCONN;
 275                                 break;
 276                         }
 277                         len = 0;
 278                         break;
 279                 }
 280
 281                 if (!timeo) {
 282                         len = -EAGAIN;
 283                         break;
 284                 }
 285
 286                 if (signal_pending(current)) {
 287                         len = sock_intr_errno(timeo);
 288                         break;
 289                 }
 290
 291                 sk_wait_data(sk, &timeo);
 292                 continue;
 293         found_ok_skb:
 294                 if (len > skb->len)
 295                         len = skb->len;
 296                 else if (len < skb->len)
 297                         msg->msg_flags |= MSG_TRUNC;
 298
 299                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 300                         /* Exception. Bailout! */
 301                         len = -EFAULT;
 302                         break;
 303                 }
 304         found_fin_ok:
 305                 if (!(flags & MSG_PEEK))
 306                         sk_eat_skb(sk, skb);
 307                 break;
 308         } while (1);
 309 out:
 310         release_sock(sk);
 311         return len;
 312 }
 313
 314 static int inet_dccp_listen(struct socket *sock, int backlog)
 315 {
 316         struct sock *sk = sock->sk;
 317         unsigned char old_state;
 318         int err;
 319
 320         lock_sock(sk);
 321
 322         err = -EINVAL;
 323         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 324                 goto out;
 325
 326         old_state = sk->sk_state;
 327         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 328                 goto out;
 329
 330         /* Really, if the socket is already in listen state
 331          * we can only allow the backlog to be adjusted.
 332          */
 333         if (old_state != DCCP_LISTEN) {
 334                 /*
 335                  * FIXME: here it probably should be sk->sk_prot->listen_start
 336                  * see tcp_listen_start
 337                  */
 338                 err = dccp_listen_start(sk);
 339                 if (err)
 340                         goto out;
 341         }
 342         sk->sk_max_ack_backlog = backlog;
 343         err = 0;
 344
 345 out:
 346         release_sock(sk);
 347         return err;
 348 }
 349
 350 static const unsigned char dccp_new_state[] = {
 351         /* current state:   new state:      action:     */
 352         [0]               = DCCP_CLOSED,
 353         [DCCP_OPEN]       = DCCP_CLOSING | DCCP_ACTION_FIN,
 354         [DCCP_REQUESTING] = DCCP_CLOSED,
 355         [DCCP_PARTOPEN]   = DCCP_CLOSING | DCCP_ACTION_FIN,
 356         [DCCP_LISTEN]     = DCCP_CLOSED,
 357         [DCCP_RESPOND]    = DCCP_CLOSED,
 358         [DCCP_CLOSING]    = DCCP_CLOSED,
 359         [DCCP_TIME_WAIT]  = DCCP_CLOSED,
 360         [DCCP_CLOSED]     = DCCP_CLOSED,
 361 };
 362
 363 static int dccp_close_state(struct sock *sk)
 364 {
 365         const int next = dccp_new_state[sk->sk_state];
 366         const int ns = next & DCCP_STATE_MASK;
 367
 368         if (ns != sk->sk_state)
 369                 dccp_set_state(sk, ns);
 370
 371         return next & DCCP_ACTION_FIN;
 372 }
 373
 374 void dccp_close(struct sock *sk, long timeout)
 375 {
 376         struct sk_buff *skb;
 377
 378         lock_sock(sk);
 379
 380         sk->sk_shutdown = SHUTDOWN_MASK;
 381
 382         if (sk->sk_state == DCCP_LISTEN) {
 383                 dccp_set_state(sk, DCCP_CLOSED);
 384
 385                 /* Special case. */
 386                 inet_csk_listen_stop(sk);
 387
 388                 goto adjudge_to_death;
 389         }
 390
 391         /*
 392          * We need to flush the recv. buffs.  We do this only on the
 393          * descriptor close, not protocol-sourced closes, because the
 394           *reader process may not have drained the data yet!
 395          */
 396         /* FIXME: check for unread data */
 397         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 398                 __kfree_skb(skb);
 399         }
 400
 401         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 402                 /* Check zero linger _after_ checking for unread data. */
 403                 sk->sk_prot->disconnect(sk, 0);
 404         } else if (dccp_close_state(sk)) {
 405                 dccp_send_close(sk, 1);
 406         }
 407
 408         sk_stream_wait_close(sk, timeout);
 409
 410 adjudge_to_death:
 411         /*
 412          * It is the last release_sock in its life. It will remove backlog.
 413          */
 414         release_sock(sk);
 415         /*
 416          * Now socket is owned by kernel and we acquire BH lock
 417          * to finish close. No need to check for user refs.
 418          */
 419         local_bh_disable();
 420         bh_lock_sock(sk);
 421         BUG_TRAP(!sock_owned_by_user(sk));
 422
 423         sock_hold(sk);
 424         sock_orphan(sk);
 425
 426         /*
 427          * The last release_sock may have processed the CLOSE or RESET
 428          * packet moving sock to CLOSED state, if not we have to fire
 429          * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
 430          * in draft-ietf-dccp-spec-11. -acme
 431          */
 432         if (sk->sk_state == DCCP_CLOSING) {
 433                 /* FIXME: should start at 2 * RTT */
 434                 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
 435                 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 436                                           inet_csk(sk)->icsk_rto,
 437                                           DCCP_RTO_MAX);
 438 #if 0
 439                 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
 440                 dccp_set_state(sk, DCCP_CLOSED);
 441 #endif
 442         }
 443
 444         atomic_inc(sk->sk_prot->orphan_count);
 445         if (sk->sk_state == DCCP_CLOSED)
 446                 inet_csk_destroy_sock(sk);
 447
 448         /* Otherwise, socket is reprieved until protocol close. */
 449
 450         bh_unlock_sock(sk);
 451         local_bh_enable();
 452         sock_put(sk);
 453 }
 454
 455 void dccp_shutdown(struct sock *sk, int how)
 456 {
 457         dccp_pr_debug("entry\n");
 458 }
 459
 460 static struct proto_ops inet_dccp_ops = {
 461         .family         = PF_INET,
 462         .owner          = THIS_MODULE,
 463         .release        = inet_release,
 464         .bind           = inet_bind,
 465         .connect        = inet_stream_connect,
 466         .socketpair     = sock_no_socketpair,
 467         .accept         = inet_accept,
 468         .getname        = inet_getname,
 469         .poll           = sock_no_poll,
 470         .ioctl          = inet_ioctl,
 471         /* FIXME: work on inet_listen to rename it to sock_common_listen */
 472         .listen         = inet_dccp_listen,
 473         .shutdown       = inet_shutdown,
 474         .setsockopt     = sock_common_setsockopt,
 475         .getsockopt     = sock_common_getsockopt,
 476         .sendmsg        = inet_sendmsg,
 477         .recvmsg        = sock_common_recvmsg,
 478         .mmap           = sock_no_mmap,
 479         .sendpage       = sock_no_sendpage,
 480 };
 481
 482 extern struct net_proto_family inet_family_ops;
 483
 484 static struct inet_protosw dccp_v4_protosw = {
 485         .type           = SOCK_DCCP,
 486         .protocol       = IPPROTO_DCCP,
 487         .prot           = &dccp_v4_prot,
 488         .ops            = &inet_dccp_ops,
 489         .capability     = -1,
 490         .no_check       = 0,
 491         .flags          = 0,
 492 };
 493
 494 /*
 495  * This is the global socket data structure used for responding to
 496  * the Out-of-the-blue (OOTB) packets. A control sock will be created
 497  * for this socket at the initialization time.
 498  */
 499 struct socket *dccp_ctl_socket;
 500
 501 static char dccp_ctl_socket_err_msg[] __initdata =
 502         KERN_ERR "DCCP: Failed to create the control socket.\n";
 503
 504 static int __init dccp_ctl_sock_init(void)
 505 {
 506         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
 507                                   &dccp_ctl_socket);
 508         if (rc < 0)
 509                 printk(dccp_ctl_socket_err_msg);
 510         else {
 511                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
 512                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
 513
 514                 /* Unhash it so that IP input processing does not even
 515                  * see it, we do not wish this socket to see incoming
 516                  * packets.
 517                  */
 518                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
 519         }
 520
 521         return rc;
 522 }
 523
 524 #ifdef CONFIG_IP_DCCP_UNLOAD_HACK
 525 void dccp_ctl_sock_exit(void)
 526 {
 527         if (dccp_ctl_socket != NULL) {
 528                 sock_release(dccp_ctl_socket);
 529                 dccp_ctl_socket = NULL;
 530         }
 531 }
 532
 533 EXPORT_SYMBOL_GPL(dccp_ctl_sock_exit);
 534 #endif
 535
 536 static int __init init_dccp_v4_mibs(void)
 537 {
 538         int rc = -ENOMEM;
 539
 540         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 541         if (dccp_statistics[0] == NULL)
 542                 goto out;
 543
 544         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 545         if (dccp_statistics[1] == NULL)
 546                 goto out_free_one;
 547
 548         rc = 0;
 549 out:
 550         return rc;
 551 out_free_one:
 552         free_percpu(dccp_statistics[0]);
 553         dccp_statistics[0] = NULL;
 554         goto out;
 555
 556 }
 557
 558 static int thash_entries;
 559 module_param(thash_entries, int, 0444);
 560 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 561
 562 #ifdef CONFIG_IP_DCCP_DEBUG
 563 int dccp_debug;
 564 module_param(dccp_debug, int, 0444);
 565 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 566 #endif
 567
 568 static int __init dccp_init(void)
 569 {
 570         unsigned long goal;
 571         int ehash_order, bhash_order, i;
 572         int rc = proto_register(&dccp_v4_prot, 1);
 573
 574         if (rc)
 575                 goto out;
 576
 577         dccp_hashinfo.bind_bucket_cachep =
 578                 kmem_cache_create("dccp_bind_bucket",
 579                                   sizeof(struct inet_bind_bucket), 0,
 580                                   SLAB_HWCACHE_ALIGN, NULL, NULL);
 581         if (!dccp_hashinfo.bind_bucket_cachep)
 582                 goto out_proto_unregister;
 583
 584         /*
 585          * Size and allocate the main established and bind bucket
 586          * hash tables.
 587          *
 588          * The methodology is similar to that of the buffer cache.
 589          */
 590         if (num_physpages >= (128 * 1024))
 591                 goal = num_physpages >> (21 - PAGE_SHIFT);
 592         else
 593                 goal = num_physpages >> (23 - PAGE_SHIFT);
 594
 595         if (thash_entries)
 596                 goal = (thash_entries *
 597                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
 598         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
 599                 ;
 600         do {
 601                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
 602                                         sizeof(struct inet_ehash_bucket);
 603                 dccp_hashinfo.ehash_size >>= 1;
 604                 while (dccp_hashinfo.ehash_size &
 605                        (dccp_hashinfo.ehash_size - 1))
 606                         dccp_hashinfo.ehash_size--;
 607                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
 608                         __get_free_pages(GFP_ATOMIC, ehash_order);
 609         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 610
 611         if (!dccp_hashinfo.ehash) {
 612                 printk(KERN_CRIT "Failed to allocate DCCP "
 613                                  "established hash table\n");
 614                 goto out_free_bind_bucket_cachep;
 615         }
 616
 617         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
 618                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
 619                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
 620         }
 621
 622         bhash_order = ehash_order;
 623
 624         do {
 625                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
 626                                         sizeof(struct inet_bind_hashbucket);
 627                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
 628                     bhash_order > 0)
 629                         continue;
 630                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
 631                         __get_free_pages(GFP_ATOMIC, bhash_order);
 632         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 633
 634         if (!dccp_hashinfo.bhash) {
 635                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
 636                 goto out_free_dccp_ehash;
 637         }
 638
 639         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 640                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 641                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
 642         }
 643
 644         if (init_dccp_v4_mibs())
 645                 goto out_free_dccp_bhash;
 646
 647         rc = -EAGAIN;
 648         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
 649                 goto out_free_dccp_v4_mibs;
 650
 651         inet_register_protosw(&dccp_v4_protosw);
 652
 653         rc = dccp_ctl_sock_init();
 654         if (rc)
 655                 goto out_unregister_protosw;
 656 out:
 657         return rc;
 658 out_unregister_protosw:
 659         inet_unregister_protosw(&dccp_v4_protosw);
 660         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
 661 out_free_dccp_v4_mibs:
 662         free_percpu(dccp_statistics[0]);
 663         free_percpu(dccp_statistics[1]);
 664         dccp_statistics[0] = dccp_statistics[1] = NULL;
 665 out_free_dccp_bhash:
 666         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 667         dccp_hashinfo.bhash = NULL;
 668 out_free_dccp_ehash:
 669         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 670         dccp_hashinfo.ehash = NULL;
 671 out_free_bind_bucket_cachep:
 672         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 673         dccp_hashinfo.bind_bucket_cachep = NULL;
 674 out_proto_unregister:
 675         proto_unregister(&dccp_v4_prot);
 676         goto out;
 677 }
 678
 679 static const char dccp_del_proto_err_msg[] __exitdata =
 680         KERN_ERR "can't remove dccp net_protocol\n";
 681
 682 static void __exit dccp_fini(void)
 683 {
 684         inet_unregister_protosw(&dccp_v4_protosw);
 685
 686         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
 687                 printk(dccp_del_proto_err_msg);
 688
 689         free_percpu(dccp_statistics[0]);
 690         free_percpu(dccp_statistics[1]);
 691         free_pages((unsigned long)dccp_hashinfo.bhash,
 692                    get_order(dccp_hashinfo.bhash_size *
 693                              sizeof(struct inet_bind_hashbucket)));
 694         free_pages((unsigned long)dccp_hashinfo.ehash,
 695                    get_order(dccp_hashinfo.ehash_size *
 696                              sizeof(struct inet_ehash_bucket)));
 697         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 698         proto_unregister(&dccp_v4_prot);
 699 }
 700
 701 module_init(dccp_init);
 702 module_exit(dccp_fini);
 703
 704 /*
 705  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
 706  * values directly, Also cover the case where the protocol is not specified,
 707  * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
 708  */
 709 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
 710 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
 711 MODULE_LICENSE("GPL");
 712 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
 713 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");