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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 *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 EXPORT_SYMBOL(dccp_sendmsg);
 218
 219 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 220                  size_t len, int nonblock, int flags, int *addr_len)
 221 {
 222         const struct dccp_hdr *dh;
 223         int copied = 0;
 224         unsigned long used;
 225         int err;
 226         int target;             /* Read at least this many bytes */
 227         long timeo;
 228
 229         lock_sock(sk);
 230
 231         err = -ENOTCONN;
 232         if (sk->sk_state == DCCP_LISTEN)
 233                 goto out;
 234
 235         timeo = sock_rcvtimeo(sk, nonblock);
 236
 237         /* Urgent data needs to be handled specially. */
 238         if (flags & MSG_OOB)
 239                 goto recv_urg;
 240
 241         /* FIXME */
 242 #if 0
 243         seq = &tp->copied_seq;
 244         if (flags & MSG_PEEK) {
 245                 peek_seq = tp->copied_seq;
 246                 seq = &peek_seq;
 247         }
 248 #endif
 249
 250         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 251
 252         do {
 253                 struct sk_buff *skb;
 254                 u32 offset;
 255
 256         /* FIXME */
 257 #if 0
 258                 /*
 259                  * Are we at urgent data? Stop if we have read anything or
 260                  * have SIGURG pending.
 261                  */
 262                 if (tp->urg_data && tp->urg_seq == *seq) {
 263                         if (copied)
 264                                 break;
 265                         if (signal_pending(current)) {
 266                                 copied = timeo ? sock_intr_errno(timeo) :
 267                                                  -EAGAIN;
 268                                 break;
 269                         }
 270                 }
 271 #endif
 272
 273                 /* Next get a buffer. */
 274
 275                 skb = skb_peek(&sk->sk_receive_queue);
 276                 do {
 277                         if (!skb)
 278                                 break;
 279
 280                         offset = 0;
 281                         dh = dccp_hdr(skb);
 282
 283                         if (dh->dccph_type == DCCP_PKT_DATA ||
 284                             dh->dccph_type == DCCP_PKT_DATAACK)
 285                                 goto found_ok_skb;
 286
 287                         if (dh->dccph_type == DCCP_PKT_RESET ||
 288                             dh->dccph_type == DCCP_PKT_CLOSE) {
 289                                 dccp_pr_debug("found fin ok!\n");
 290                                 goto found_fin_ok;
 291                         }
 292                         dccp_pr_debug("packet_type=%s\n",
 293                                       dccp_packet_name(dh->dccph_type));
 294                         BUG_TRAP(flags & MSG_PEEK);
 295                         skb = skb->next;
 296                 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
 297
 298                 /* Well, if we have backlog, try to process it now yet. */
 299                 if (copied >= target && !sk->sk_backlog.tail)
 300                         break;
 301
 302                 if (copied) {
 303                         if (sk->sk_err ||
 304                             sk->sk_state == DCCP_CLOSED ||
 305                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 306                             !timeo ||
 307                             signal_pending(current) ||
 308                             (flags & MSG_PEEK))
 309                                 break;
 310                 } else {
 311                         if (sock_flag(sk, SOCK_DONE))
 312                                 break;
 313
 314                         if (sk->sk_err) {
 315                                 copied = sock_error(sk);
 316                                 break;
 317                         }
 318
 319                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 320                                 break;
 321
 322                         if (sk->sk_state == DCCP_CLOSED) {
 323                                 if (!sock_flag(sk, SOCK_DONE)) {
 324                                         /* This occurs when user tries to read
 325                                          * from never connected socket.
 326                                          */
 327                                         copied = -ENOTCONN;
 328                                         break;
 329                                 }
 330                                 break;
 331                         }
 332
 333                         if (!timeo) {
 334                                 copied = -EAGAIN;
 335                                 break;
 336                         }
 337
 338                         if (signal_pending(current)) {
 339                                 copied = sock_intr_errno(timeo);
 340                                 break;
 341                         }
 342                 }
 343
 344                 /* FIXME: cleanup_rbuf(sk, copied); */
 345
 346                 if (copied >= target) {
 347                         /* Do not sleep, just process backlog. */
 348                         release_sock(sk);
 349                         lock_sock(sk);
 350                 } else
 351                         sk_wait_data(sk, &timeo);
 352
 353                 continue;
 354
 355         found_ok_skb:
 356                 /* Ok so how much can we use? */
 357                 used = skb->len - offset;
 358                 if (len < used)
 359                         used = len;
 360
 361                 if (!(flags & MSG_TRUNC)) {
 362                         err = skb_copy_datagram_iovec(skb, offset,
 363                                                       msg->msg_iov, used);
 364                         if (err) {
 365                                 /* Exception. Bailout! */
 366                                 if (!copied)
 367                                         copied = -EFAULT;
 368                                 break;
 369                         }
 370                 }
 371
 372                 copied += used;
 373                 len -= used;
 374
 375                 /* FIXME: tcp_rcv_space_adjust(sk); */
 376
 377 //skip_copy:
 378                 if (used + offset < skb->len)
 379                         continue;
 380
 381                 if (!(flags & MSG_PEEK))
 382                         sk_eat_skb(sk, skb);
 383                 continue;
 384         found_fin_ok:
 385                 if (!(flags & MSG_PEEK))
 386                         sk_eat_skb(sk, skb);
 387                 break;
 388
 389         } while (len > 0);
 390
 391         /* According to UNIX98, msg_name/msg_namelen are ignored
 392          * on connected socket. I was just happy when found this 8) --ANK
 393          */
 394
 395         /* Clean up data we have read: This will do ACK frames. */
 396         /* FIXME: cleanup_rbuf(sk, copied); */
 397
 398         release_sock(sk);
 399         return copied;
 400
 401 out:
 402         release_sock(sk);
 403         return err;
 404
 405 recv_urg:
 406         /* FIXME: err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); */
 407         goto out;
 408 }
 409
 410 static int inet_dccp_listen(struct socket *sock, int backlog)
 411 {
 412         struct sock *sk = sock->sk;
 413         unsigned char old_state;
 414         int err;
 415
 416         lock_sock(sk);
 417
 418         err = -EINVAL;
 419         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 420                 goto out;
 421
 422         old_state = sk->sk_state;
 423         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 424                 goto out;
 425
 426         /* Really, if the socket is already in listen state
 427          * we can only allow the backlog to be adjusted.
 428          */
 429         if (old_state != DCCP_LISTEN) {
 430                 /*
 431                  * FIXME: here it probably should be sk->sk_prot->listen_start
 432                  * see tcp_listen_start
 433                  */
 434                 err = dccp_listen_start(sk);
 435                 if (err)
 436                         goto out;
 437         }
 438         sk->sk_max_ack_backlog = backlog;
 439         err = 0;
 440
 441 out:
 442         release_sock(sk);
 443         return err;
 444 }
 445
 446 static const unsigned char dccp_new_state[] = {
 447         /* current state:   new state:      action:     */
 448         [0]               = DCCP_CLOSED,
 449         [DCCP_OPEN]       = DCCP_CLOSING | DCCP_ACTION_FIN,
 450         [DCCP_REQUESTING] = DCCP_CLOSED,
 451         [DCCP_PARTOPEN]   = DCCP_CLOSING | DCCP_ACTION_FIN,
 452         [DCCP_LISTEN]     = DCCP_CLOSED,
 453         [DCCP_RESPOND]    = DCCP_CLOSED,
 454         [DCCP_CLOSING]    = DCCP_CLOSED,
 455         [DCCP_TIME_WAIT]  = DCCP_CLOSED,
 456         [DCCP_CLOSED]     = DCCP_CLOSED,
 457 };
 458
 459 static int dccp_close_state(struct sock *sk)
 460 {
 461         const int next = dccp_new_state[sk->sk_state];
 462         const int ns = next & DCCP_STATE_MASK;
 463
 464         if (ns != sk->sk_state)
 465                 dccp_set_state(sk, ns);
 466
 467         return next & DCCP_ACTION_FIN;
 468 }
 469
 470 void dccp_close(struct sock *sk, long timeout)
 471 {
 472         struct sk_buff *skb;
 473
 474         lock_sock(sk);
 475
 476         sk->sk_shutdown = SHUTDOWN_MASK;
 477
 478         if (sk->sk_state == DCCP_LISTEN) {
 479                 dccp_set_state(sk, DCCP_CLOSED);
 480
 481                 /* Special case. */
 482                 inet_csk_listen_stop(sk);
 483
 484                 goto adjudge_to_death;
 485         }
 486
 487         /*
 488          * We need to flush the recv. buffs.  We do this only on the
 489          * descriptor close, not protocol-sourced closes, because the
 490           *reader process may not have drained the data yet!
 491          */
 492         /* FIXME: check for unread data */
 493         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 494                 __kfree_skb(skb);
 495         }
 496
 497         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 498                 /* Check zero linger _after_ checking for unread data. */
 499                 sk->sk_prot->disconnect(sk, 0);
 500         } else if (dccp_close_state(sk)) {
 501                 dccp_send_close(sk);
 502         }
 503
 504         sk_stream_wait_close(sk, timeout);
 505
 506 adjudge_to_death:
 507         release_sock(sk);
 508         /*
 509          * Now socket is owned by kernel and we acquire BH lock
 510          * to finish close. No need to check for user refs.
 511          */
 512         local_bh_disable();
 513         bh_lock_sock(sk);
 514         BUG_TRAP(!sock_owned_by_user(sk));
 515
 516         sock_hold(sk);
 517         sock_orphan(sk);
 518
 519         if (sk->sk_state != DCCP_CLOSED)
 520                 dccp_set_state(sk, DCCP_CLOSED);
 521
 522         atomic_inc(&dccp_orphan_count);
 523         if (sk->sk_state == DCCP_CLOSED)
 524                 inet_csk_destroy_sock(sk);
 525
 526         /* Otherwise, socket is reprieved until protocol close. */
 527
 528         bh_unlock_sock(sk);
 529         local_bh_enable();
 530         sock_put(sk);
 531 }
 532
 533 void dccp_shutdown(struct sock *sk, int how)
 534 {
 535         dccp_pr_debug("entry\n");
 536 }
 537
 538 struct proto_ops inet_dccp_ops = {
 539         .family         = PF_INET,
 540         .owner          = THIS_MODULE,
 541         .release        = inet_release,
 542         .bind           = inet_bind,
 543         .connect        = inet_stream_connect,
 544         .socketpair     = sock_no_socketpair,
 545         .accept         = inet_accept,
 546         .getname        = inet_getname,
 547         .poll           = sock_no_poll,
 548         .ioctl          = inet_ioctl,
 549         /* FIXME: work on inet_listen to rename it to sock_common_listen */
 550         .listen         = inet_dccp_listen,
 551         .shutdown       = inet_shutdown,
 552         .setsockopt     = sock_common_setsockopt,
 553         .getsockopt     = sock_common_getsockopt,
 554         .sendmsg        = inet_sendmsg,
 555         .recvmsg        = sock_common_recvmsg,
 556         .mmap           = sock_no_mmap,
 557         .sendpage       = sock_no_sendpage,
 558 };
 559
 560 extern struct net_proto_family inet_family_ops;
 561
 562 static struct inet_protosw dccp_v4_protosw = {
 563         .type           = SOCK_DCCP,
 564         .protocol       = IPPROTO_DCCP,
 565         .prot           = &dccp_v4_prot,
 566         .ops            = &inet_dccp_ops,
 567         .capability     = -1,
 568         .no_check       = 0,
 569         .flags          = 0,
 570 };
 571
 572 /*
 573  * This is the global socket data structure used for responding to
 574  * the Out-of-the-blue (OOTB) packets. A control sock will be created
 575  * for this socket at the initialization time.
 576  */
 577 struct socket *dccp_ctl_socket;
 578
 579 static char dccp_ctl_socket_err_msg[] __initdata =
 580         KERN_ERR "DCCP: Failed to create the control socket.\n";
 581
 582 static int __init dccp_ctl_sock_init(void)
 583 {
 584         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
 585                                   &dccp_ctl_socket);
 586         if (rc < 0)
 587                 printk(dccp_ctl_socket_err_msg);
 588         else {
 589                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
 590                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
 591
 592                 /* Unhash it so that IP input processing does not even
 593                  * see it, we do not wish this socket to see incoming
 594                  * packets.
 595                  */
 596                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
 597         }
 598
 599         return rc;
 600 }
 601
 602 static void __exit dccp_ctl_sock_exit(void)
 603 {
 604         if (dccp_ctl_socket != NULL)
 605                 sock_release(dccp_ctl_socket);
 606 }
 607
 608 static int __init init_dccp_v4_mibs(void)
 609 {
 610         int rc = -ENOMEM;
 611
 612         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 613         if (dccp_statistics[0] == NULL)
 614                 goto out;
 615
 616         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 617         if (dccp_statistics[1] == NULL)
 618                 goto out_free_one;
 619
 620         rc = 0;
 621 out:
 622         return rc;
 623 out_free_one:
 624         free_percpu(dccp_statistics[0]);
 625         dccp_statistics[0] = NULL;
 626         goto out;
 627
 628 }
 629
 630 static int thash_entries;
 631 module_param(thash_entries, int, 0444);
 632 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 633
 634 int dccp_debug;
 635 module_param(dccp_debug, int, 0444);
 636 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 637
 638 static int __init dccp_init(void)
 639 {
 640         unsigned long goal;
 641         int ehash_order, bhash_order, i;
 642         int rc = proto_register(&dccp_v4_prot, 1);
 643
 644         if (rc)
 645                 goto out;
 646
 647         dccp_hashinfo.bind_bucket_cachep =
 648                 kmem_cache_create("dccp_bind_bucket",
 649                                   sizeof(struct inet_bind_bucket), 0,
 650                                   SLAB_HWCACHE_ALIGN, NULL, NULL);
 651         if (!dccp_hashinfo.bind_bucket_cachep)
 652                 goto out_proto_unregister;
 653
 654         /*
 655          * Size and allocate the main established and bind bucket
 656          * hash tables.
 657          *
 658          * The methodology is similar to that of the buffer cache.
 659          */
 660         if (num_physpages >= (128 * 1024))
 661                 goal = num_physpages >> (21 - PAGE_SHIFT);
 662         else
 663                 goal = num_physpages >> (23 - PAGE_SHIFT);
 664
 665         if (thash_entries)
 666                 goal = (thash_entries *
 667                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
 668         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
 669                 ;
 670         do {
 671                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
 672                                         sizeof(struct inet_ehash_bucket);
 673                 dccp_hashinfo.ehash_size >>= 1;
 674                 while (dccp_hashinfo.ehash_size &
 675                        (dccp_hashinfo.ehash_size - 1))
 676                         dccp_hashinfo.ehash_size--;
 677                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
 678                         __get_free_pages(GFP_ATOMIC, ehash_order);
 679         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 680
 681         if (!dccp_hashinfo.ehash) {
 682                 printk(KERN_CRIT "Failed to allocate DCCP "
 683                                  "established hash table\n");
 684                 goto out_free_bind_bucket_cachep;
 685         }
 686
 687         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
 688                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
 689                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
 690         }
 691
 692         bhash_order = ehash_order;
 693
 694         do {
 695                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
 696                                         sizeof(struct inet_bind_hashbucket);
 697                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
 698                     bhash_order > 0)
 699                         continue;
 700                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
 701                         __get_free_pages(GFP_ATOMIC, bhash_order);
 702         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 703
 704         if (!dccp_hashinfo.bhash) {
 705                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
 706                 goto out_free_dccp_ehash;
 707         }
 708
 709         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 710                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 711                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
 712         }
 713
 714         if (init_dccp_v4_mibs())
 715                 goto out_free_dccp_bhash;
 716
 717         rc = -EAGAIN;
 718         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
 719                 goto out_free_dccp_v4_mibs;
 720
 721         inet_register_protosw(&dccp_v4_protosw);
 722
 723         rc = dccp_ctl_sock_init();
 724         if (rc)
 725                 goto out_unregister_protosw;
 726 out:
 727         return rc;
 728 out_unregister_protosw:
 729         inet_unregister_protosw(&dccp_v4_protosw);
 730         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
 731 out_free_dccp_v4_mibs:
 732         free_percpu(dccp_statistics[0]);
 733         free_percpu(dccp_statistics[1]);
 734         dccp_statistics[0] = dccp_statistics[1] = NULL;
 735 out_free_dccp_bhash:
 736         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 737         dccp_hashinfo.bhash = NULL;
 738 out_free_dccp_ehash:
 739         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 740         dccp_hashinfo.ehash = NULL;
 741 out_free_bind_bucket_cachep:
 742         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 743         dccp_hashinfo.bind_bucket_cachep = NULL;
 744 out_proto_unregister:
 745         proto_unregister(&dccp_v4_prot);
 746         goto out;
 747 }
 748
 749 static const char dccp_del_proto_err_msg[] __exitdata =
 750         KERN_ERR "can't remove dccp net_protocol\n";
 751
 752 static void __exit dccp_fini(void)
 753 {
 754         dccp_ctl_sock_exit();
 755
 756         inet_unregister_protosw(&dccp_v4_protosw);
 757
 758         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
 759                 printk(dccp_del_proto_err_msg);
 760
 761         /* Free the control endpoint.  */
 762         sock_release(dccp_ctl_socket);
 763
 764         proto_unregister(&dccp_v4_prot);
 765
 766         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 767 }
 768
 769 module_init(dccp_init);
 770 module_exit(dccp_fini);
 771
 772 /*
 773  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
 774  * values directly, Also cover the case where the protocol is not specified,
 775  * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
 776  */
 777 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
 778 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
 779 MODULE_LICENSE("GPL");
 780 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
 781 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");