net/dccp/proto.c

   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 *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 *optval, int *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);
 406         }
 407
 408         sk_stream_wait_close(sk, timeout);
 409
 410 adjudge_to_death:
 411         release_sock(sk);
 412         /*
 413          * Now socket is owned by kernel and we acquire BH lock
 414          * to finish close. No need to check for user refs.
 415          */
 416         local_bh_disable();
 417         bh_lock_sock(sk);
 418         BUG_TRAP(!sock_owned_by_user(sk));
 419
 420         sock_hold(sk);
 421         sock_orphan(sk);
 422
 423         if (sk->sk_state != DCCP_CLOSED)
 424                 dccp_set_state(sk, DCCP_CLOSED);
 425
 426         atomic_inc(&dccp_orphan_count);
 427         if (sk->sk_state == DCCP_CLOSED)
 428                 inet_csk_destroy_sock(sk);
 429
 430         /* Otherwise, socket is reprieved until protocol close. */
 431
 432         bh_unlock_sock(sk);
 433         local_bh_enable();
 434         sock_put(sk);
 435 }
 436
 437 void dccp_shutdown(struct sock *sk, int how)
 438 {
 439         dccp_pr_debug("entry\n");
 440 }
 441
 442 struct proto_ops inet_dccp_ops = {
 443         .family         = PF_INET,
 444         .owner          = THIS_MODULE,
 445         .release        = inet_release,
 446         .bind           = inet_bind,
 447         .connect        = inet_stream_connect,
 448         .socketpair     = sock_no_socketpair,
 449         .accept         = inet_accept,
 450         .getname        = inet_getname,
 451         .poll           = sock_no_poll,
 452         .ioctl          = inet_ioctl,
 453         /* FIXME: work on inet_listen to rename it to sock_common_listen */
 454         .listen         = inet_dccp_listen,
 455         .shutdown       = inet_shutdown,
 456         .setsockopt     = sock_common_setsockopt,
 457         .getsockopt     = sock_common_getsockopt,
 458         .sendmsg        = inet_sendmsg,
 459         .recvmsg        = sock_common_recvmsg,
 460         .mmap           = sock_no_mmap,
 461         .sendpage       = sock_no_sendpage,
 462 };
 463
 464 extern struct net_proto_family inet_family_ops;
 465
 466 static struct inet_protosw dccp_v4_protosw = {
 467         .type           = SOCK_DCCP,
 468         .protocol       = IPPROTO_DCCP,
 469         .prot           = &dccp_v4_prot,
 470         .ops            = &inet_dccp_ops,
 471         .capability     = -1,
 472         .no_check       = 0,
 473         .flags          = 0,
 474 };
 475
 476 /*
 477  * This is the global socket data structure used for responding to
 478  * the Out-of-the-blue (OOTB) packets. A control sock will be created
 479  * for this socket at the initialization time.
 480  */
 481 struct socket *dccp_ctl_socket;
 482
 483 static char dccp_ctl_socket_err_msg[] __initdata =
 484         KERN_ERR "DCCP: Failed to create the control socket.\n";
 485
 486 static int __init dccp_ctl_sock_init(void)
 487 {
 488         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
 489                                   &dccp_ctl_socket);
 490         if (rc < 0)
 491                 printk(dccp_ctl_socket_err_msg);
 492         else {
 493                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
 494                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
 495
 496                 /* Unhash it so that IP input processing does not even
 497                  * see it, we do not wish this socket to see incoming
 498                  * packets.
 499                  */
 500                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
 501         }
 502
 503         return rc;
 504 }
 505
 506 static void __exit dccp_ctl_sock_exit(void)
 507 {
 508         if (dccp_ctl_socket != NULL)
 509                 sock_release(dccp_ctl_socket);
 510 }
 511
 512 static int __init init_dccp_v4_mibs(void)
 513 {
 514         int rc = -ENOMEM;
 515
 516         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 517         if (dccp_statistics[0] == NULL)
 518                 goto out;
 519
 520         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 521         if (dccp_statistics[1] == NULL)
 522                 goto out_free_one;
 523
 524         rc = 0;
 525 out:
 526         return rc;
 527 out_free_one:
 528         free_percpu(dccp_statistics[0]);
 529         dccp_statistics[0] = NULL;
 530         goto out;
 531
 532 }
 533
 534 static int thash_entries;
 535 module_param(thash_entries, int, 0444);
 536 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 537
 538 int dccp_debug;
 539 module_param(dccp_debug, int, 0444);
 540 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 541
 542 static int __init dccp_init(void)
 543 {
 544         unsigned long goal;
 545         int ehash_order, bhash_order, i;
 546         int rc = proto_register(&dccp_v4_prot, 1);
 547
 548         if (rc)
 549                 goto out;
 550
 551         dccp_hashinfo.bind_bucket_cachep =
 552                 kmem_cache_create("dccp_bind_bucket",
 553                                   sizeof(struct inet_bind_bucket), 0,
 554                                   SLAB_HWCACHE_ALIGN, NULL, NULL);
 555         if (!dccp_hashinfo.bind_bucket_cachep)
 556                 goto out_proto_unregister;
 557
 558         /*
 559          * Size and allocate the main established and bind bucket
 560          * hash tables.
 561          *
 562          * The methodology is similar to that of the buffer cache.
 563          */
 564         if (num_physpages >= (128 * 1024))
 565                 goal = num_physpages >> (21 - PAGE_SHIFT);
 566         else
 567                 goal = num_physpages >> (23 - PAGE_SHIFT);
 568
 569         if (thash_entries)
 570                 goal = (thash_entries *
 571                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
 572         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
 573                 ;
 574         do {
 575                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
 576                                         sizeof(struct inet_ehash_bucket);
 577                 dccp_hashinfo.ehash_size >>= 1;
 578                 while (dccp_hashinfo.ehash_size &
 579                        (dccp_hashinfo.ehash_size - 1))
 580                         dccp_hashinfo.ehash_size--;
 581                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
 582                         __get_free_pages(GFP_ATOMIC, ehash_order);
 583         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 584
 585         if (!dccp_hashinfo.ehash) {
 586                 printk(KERN_CRIT "Failed to allocate DCCP "
 587                                  "established hash table\n");
 588                 goto out_free_bind_bucket_cachep;
 589         }
 590
 591         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
 592                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
 593                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
 594         }
 595
 596         bhash_order = ehash_order;
 597
 598         do {
 599                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
 600                                         sizeof(struct inet_bind_hashbucket);
 601                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
 602                     bhash_order > 0)
 603                         continue;
 604                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
 605                         __get_free_pages(GFP_ATOMIC, bhash_order);
 606         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 607
 608         if (!dccp_hashinfo.bhash) {
 609                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
 610                 goto out_free_dccp_ehash;
 611         }
 612
 613         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 614                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 615                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
 616         }
 617
 618         if (init_dccp_v4_mibs())
 619                 goto out_free_dccp_bhash;
 620
 621         rc = -EAGAIN;
 622         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
 623                 goto out_free_dccp_v4_mibs;
 624
 625         inet_register_protosw(&dccp_v4_protosw);
 626
 627         rc = dccp_ctl_sock_init();
 628         if (rc)
 629                 goto out_unregister_protosw;
 630 out:
 631         return rc;
 632 out_unregister_protosw:
 633         inet_unregister_protosw(&dccp_v4_protosw);
 634         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
 635 out_free_dccp_v4_mibs:
 636         free_percpu(dccp_statistics[0]);
 637         free_percpu(dccp_statistics[1]);
 638         dccp_statistics[0] = dccp_statistics[1] = NULL;
 639 out_free_dccp_bhash:
 640         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 641         dccp_hashinfo.bhash = NULL;
 642 out_free_dccp_ehash:
 643         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 644         dccp_hashinfo.ehash = NULL;
 645 out_free_bind_bucket_cachep:
 646         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 647         dccp_hashinfo.bind_bucket_cachep = NULL;
 648 out_proto_unregister:
 649         proto_unregister(&dccp_v4_prot);
 650         goto out;
 651 }
 652
 653 static const char dccp_del_proto_err_msg[] __exitdata =
 654         KERN_ERR "can't remove dccp net_protocol\n";
 655
 656 static void __exit dccp_fini(void)
 657 {
 658         dccp_ctl_sock_exit();
 659
 660         inet_unregister_protosw(&dccp_v4_protosw);
 661
 662         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
 663                 printk(dccp_del_proto_err_msg);
 664
 665         /* Free the control endpoint.  */
 666         sock_release(dccp_ctl_socket);
 667
 668         proto_unregister(&dccp_v4_prot);
 669
 670         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 671 }
 672
 673 module_init(dccp_init);
 674 module_exit(dccp_fini);
 675
 676 /*
 677  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
 678  * values directly, Also cover the case where the protocol is not specified,
 679  * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
 680  */
 681 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
 682 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
 683 MODULE_LICENSE("GPL");
 684 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
 685 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");