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
 186         timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
 187
 188         /*
 189          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 190          * so that the trick in dccp_rcv_request_sent_state_process.
 191          */
 192         /* Wait for a connection to finish. */
 193         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
 194                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 195                         goto out_err;
 196
 197         size = sk->sk_prot->max_header + len;
 198         release_sock(sk);
 199         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 200         lock_sock(sk);
 201
 202         if (skb == NULL)
 203                 goto out_release;
 204
 205         skb_reserve(skb, sk->sk_prot->max_header);
 206         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 207         if (rc == 0) {
 208                 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 209                 const struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
 210                 long delay;
 211
 212                 /*
 213                  * XXX: This is just to match the Waikato tree CA interaction
 214                  * points, after the CCID3 code is stable and I have a better
 215                  * understanding of behaviour I'll change this to look more like
 216                  * TCP.
 217                  */
 218                 while (1) {
 219                         rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk,
 220                                                     skb, len, &delay);
 221                         if (rc == 0)
 222                                 break;
 223                         if (rc != -EAGAIN)
 224                                 goto out_discard;
 225                         if (delay > timeo)
 226                                 goto out_discard;
 227                         release_sock(sk);
 228                         delay = schedule_timeout(delay);
 229                         lock_sock(sk);
 230                         timeo -= delay;
 231                         if (signal_pending(current))
 232                                 goto out_interrupted;
 233                         rc = -EPIPE;
 234                         if (!(sk->sk_state == DCCP_PARTOPEN || sk->sk_state == DCCP_OPEN))
 235                                 goto out_discard;
 236                 }
 237
 238                 if (sk->sk_state == DCCP_PARTOPEN) {
 239                         /* See 8.1.5.  Handshake Completion */
 240                         inet_csk_schedule_ack(sk);
 241                         inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
 242                         dcb->dccpd_type = DCCP_PKT_DATAACK;
 243                         /* FIXME: we really should have a dccps_ack_pending or use icsk */
 244                 } else if (inet_csk_ack_scheduled(sk) ||
 245                            (dp->dccps_options.dccpo_send_ack_vector &&
 246                             ap->dccpap_buf_ackno != DCCP_MAX_SEQNO + 1 &&
 247                             ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1))
 248                         dcb->dccpd_type = DCCP_PKT_DATAACK;
 249                 else
 250                         dcb->dccpd_type = DCCP_PKT_DATA;
 251                 dccp_transmit_skb(sk, skb);
 252                 ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
 253         } else {
 254 out_discard:
 255                 kfree_skb(skb);
 256         }
 257 out_release:
 258         release_sock(sk);
 259         return rc ? : len;
 260 out_err:
 261         rc = sk_stream_error(sk, flags, rc);
 262         goto out_release;
 263 out_interrupted:
 264         rc = sock_intr_errno(timeo);
 265         goto out_discard;
 266 }
 267
 268 EXPORT_SYMBOL(dccp_sendmsg);
 269
 270 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 271                  size_t len, int nonblock, int flags, int *addr_len)
 272 {
 273         const struct dccp_hdr *dh;
 274         int copied = 0;
 275         unsigned long used;
 276         int err;
 277         int target;             /* Read at least this many bytes */
 278         long timeo;
 279
 280         lock_sock(sk);
 281
 282         err = -ENOTCONN;
 283         if (sk->sk_state == DCCP_LISTEN)
 284                 goto out;
 285
 286         timeo = sock_rcvtimeo(sk, nonblock);
 287
 288         /* Urgent data needs to be handled specially. */
 289         if (flags & MSG_OOB)
 290                 goto recv_urg;
 291
 292         /* FIXME */
 293 #if 0
 294         seq = &tp->copied_seq;
 295         if (flags & MSG_PEEK) {
 296                 peek_seq = tp->copied_seq;
 297                 seq = &peek_seq;
 298         }
 299 #endif
 300
 301         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 302
 303         do {
 304                 struct sk_buff *skb;
 305                 u32 offset;
 306
 307         /* FIXME */
 308 #if 0
 309                 /* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
 310                 if (tp->urg_data && tp->urg_seq == *seq) {
 311                         if (copied)
 312                                 break;
 313                         if (signal_pending(current)) {
 314                                 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 315                                 break;
 316                         }
 317                 }
 318 #endif
 319
 320                 /* Next get a buffer. */
 321
 322                 skb = skb_peek(&sk->sk_receive_queue);
 323                 do {
 324                         if (!skb)
 325                                 break;
 326
 327                         offset = 0;
 328                         dh = dccp_hdr(skb);
 329
 330                         if (dh->dccph_type == DCCP_PKT_DATA ||
 331                             dh->dccph_type == DCCP_PKT_DATAACK)
 332                                 goto found_ok_skb;
 333
 334                         if (dh->dccph_type == DCCP_PKT_RESET ||
 335                             dh->dccph_type == DCCP_PKT_CLOSE) {
 336                                 dccp_pr_debug("found fin ok!\n");
 337                                 goto found_fin_ok;
 338                         }
 339                         dccp_pr_debug("packet_type=%s\n", dccp_packet_name(dh->dccph_type));
 340                         BUG_TRAP(flags & MSG_PEEK);
 341                         skb = skb->next;
 342                 } while (skb != (struct sk_buff *)&sk->sk_receive_queue);
 343
 344                 /* Well, if we have backlog, try to process it now yet. */
 345                 if (copied >= target && !sk->sk_backlog.tail)
 346                         break;
 347
 348                 if (copied) {
 349                         if (sk->sk_err ||
 350                             sk->sk_state == DCCP_CLOSED ||
 351                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 352                             !timeo ||
 353                             signal_pending(current) ||
 354                             (flags & MSG_PEEK))
 355                                 break;
 356                 } else {
 357                         if (sock_flag(sk, SOCK_DONE))
 358                                 break;
 359
 360                         if (sk->sk_err) {
 361                                 copied = sock_error(sk);
 362                                 break;
 363                         }
 364
 365                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 366                                 break;
 367
 368                         if (sk->sk_state == DCCP_CLOSED) {
 369                                 if (!sock_flag(sk, SOCK_DONE)) {
 370                                         /* This occurs when user tries to read
 371                                          * from never connected socket.
 372                                          */
 373                                         copied = -ENOTCONN;
 374                                         break;
 375                                 }
 376                                 break;
 377                         }
 378
 379                         if (!timeo) {
 380                                 copied = -EAGAIN;
 381                                 break;
 382                         }
 383
 384                         if (signal_pending(current)) {
 385                                 copied = sock_intr_errno(timeo);
 386                                 break;
 387                         }
 388                 }
 389
 390                 /* FIXME: cleanup_rbuf(sk, copied); */
 391
 392                 if (copied >= target) {
 393                         /* Do not sleep, just process backlog. */
 394                         release_sock(sk);
 395                         lock_sock(sk);
 396                 } else
 397                         sk_wait_data(sk, &timeo);
 398
 399                 continue;
 400
 401         found_ok_skb:
 402                 /* Ok so how much can we use? */
 403                 used = skb->len - offset;
 404                 if (len < used)
 405                         used = len;
 406
 407                 if (!(flags & MSG_TRUNC)) {
 408                         err = skb_copy_datagram_iovec(skb, offset,
 409                                                       msg->msg_iov, used);
 410                         if (err) {
 411                                 /* Exception. Bailout! */
 412                                 if (!copied)
 413                                         copied = -EFAULT;
 414                                 break;
 415                         }
 416                 }
 417
 418                 copied += used;
 419                 len -= used;
 420
 421                 /* FIXME: tcp_rcv_space_adjust(sk); */
 422
 423 //skip_copy:
 424                 if (used + offset < skb->len)
 425                         continue;
 426
 427                 if (!(flags & MSG_PEEK))
 428                         sk_eat_skb(sk, skb);
 429                 continue;
 430         found_fin_ok:
 431                 if (!(flags & MSG_PEEK))
 432                         sk_eat_skb(sk, skb);
 433                 break;
 434
 435         } while (len > 0);
 436
 437         /* According to UNIX98, msg_name/msg_namelen are ignored
 438          * on connected socket. I was just happy when found this 8) --ANK
 439          */
 440
 441         /* Clean up data we have read: This will do ACK frames. */
 442         /* FIXME: cleanup_rbuf(sk, copied); */
 443
 444         release_sock(sk);
 445         return copied;
 446
 447 out:
 448         release_sock(sk);
 449         return err;
 450
 451 recv_urg:
 452         /* FIXME: err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len); */
 453         goto out;
 454 }
 455
 456 static int inet_dccp_listen(struct socket *sock, int backlog)
 457 {
 458         struct sock *sk = sock->sk;
 459         unsigned char old_state;
 460         int err;
 461
 462         lock_sock(sk);
 463
 464         err = -EINVAL;
 465         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 466                 goto out;
 467
 468         old_state = sk->sk_state;
 469         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 470                 goto out;
 471
 472         /* Really, if the socket is already in listen state
 473          * we can only allow the backlog to be adjusted.
 474          */
 475         if (old_state != DCCP_LISTEN) {
 476                 /*
 477                  * FIXME: here it probably should be sk->sk_prot->listen_start
 478                  * see tcp_listen_start
 479                  */
 480                 err = dccp_listen_start(sk);
 481                 if (err)
 482                         goto out;
 483         }
 484         sk->sk_max_ack_backlog = backlog;
 485         err = 0;
 486
 487 out:
 488         release_sock(sk);
 489         return err;
 490 }
 491
 492 static const unsigned char dccp_new_state[] = {
 493         /* current state:        new state:      action:        */
 494         [0]                     = DCCP_CLOSED,
 495         [DCCP_OPEN]             = DCCP_CLOSING | DCCP_ACTION_FIN,
 496         [DCCP_REQUESTING]       = DCCP_CLOSED,
 497         [DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
 498         [DCCP_LISTEN]           = DCCP_CLOSED,
 499         [DCCP_RESPOND]  = DCCP_CLOSED,
 500         [DCCP_CLOSING]  = DCCP_CLOSED,
 501         [DCCP_TIME_WAIT]        = DCCP_CLOSED,
 502         [DCCP_CLOSED]   = DCCP_CLOSED,
 503 };
 504
 505 static int dccp_close_state(struct sock *sk)
 506 {
 507         const int next = dccp_new_state[sk->sk_state];
 508         const int ns = next & DCCP_STATE_MASK;
 509
 510         if (ns != sk->sk_state)
 511                 dccp_set_state(sk, ns);
 512
 513         return next & DCCP_ACTION_FIN;
 514 }
 515
 516 void dccp_close(struct sock *sk, long timeout)
 517 {
 518         struct sk_buff *skb;
 519
 520         lock_sock(sk);
 521
 522         sk->sk_shutdown = SHUTDOWN_MASK;
 523
 524         if (sk->sk_state == DCCP_LISTEN) {
 525                 dccp_set_state(sk, DCCP_CLOSED);
 526
 527                 /* Special case. */
 528                 inet_csk_listen_stop(sk);
 529
 530                 goto adjudge_to_death;
 531         }
 532
 533         /*
 534          * We need to flush the recv. buffs.  We do this only on the
 535          * descriptor close, not protocol-sourced closes, because the
 536           *reader process may not have drained the data yet!
 537          */
 538         /* FIXME: check for unread data */
 539         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 540                 __kfree_skb(skb);
 541         }
 542
 543         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 544                 /* Check zero linger _after_ checking for unread data. */
 545                 sk->sk_prot->disconnect(sk, 0);
 546         } else if (dccp_close_state(sk)) {
 547                 dccp_send_close(sk);
 548         }
 549
 550         sk_stream_wait_close(sk, timeout);
 551
 552 adjudge_to_death:
 553         release_sock(sk);
 554         /*
 555          * Now socket is owned by kernel and we acquire BH lock
 556          * to finish close. No need to check for user refs.
 557          */
 558         local_bh_disable();
 559         bh_lock_sock(sk);
 560         BUG_TRAP(!sock_owned_by_user(sk));
 561
 562         sock_hold(sk);
 563         sock_orphan(sk);
 564
 565         if (sk->sk_state != DCCP_CLOSED)
 566                 dccp_set_state(sk, DCCP_CLOSED);
 567
 568         atomic_inc(&dccp_orphan_count);
 569         if (sk->sk_state == DCCP_CLOSED)
 570                 inet_csk_destroy_sock(sk);
 571
 572         /* Otherwise, socket is reprieved until protocol close. */
 573
 574         bh_unlock_sock(sk);
 575         local_bh_enable();
 576         sock_put(sk);
 577 }
 578
 579 void dccp_shutdown(struct sock *sk, int how)
 580 {
 581         dccp_pr_debug("entry\n");
 582 }
 583
 584 struct proto_ops inet_dccp_ops = {
 585         .family         = PF_INET,
 586         .owner          = THIS_MODULE,
 587         .release        = inet_release,
 588         .bind           = inet_bind,
 589         .connect        = inet_stream_connect,
 590         .socketpair     = sock_no_socketpair,
 591         .accept         = inet_accept,
 592         .getname        = inet_getname,
 593         .poll           = sock_no_poll,
 594         .ioctl          = inet_ioctl,
 595         .listen         = inet_dccp_listen, /* FIXME: work on inet_listen to rename it to sock_common_listen */
 596         .shutdown       = inet_shutdown,
 597         .setsockopt     = sock_common_setsockopt,
 598         .getsockopt     = sock_common_getsockopt,
 599         .sendmsg        = inet_sendmsg,
 600         .recvmsg        = sock_common_recvmsg,
 601         .mmap           = sock_no_mmap,
 602         .sendpage       = sock_no_sendpage,
 603 };
 604
 605 extern struct net_proto_family inet_family_ops;
 606
 607 static struct inet_protosw dccp_v4_protosw = {
 608         .type           = SOCK_DCCP,
 609         .protocol       = IPPROTO_DCCP,
 610         .prot           = &dccp_v4_prot,
 611         .ops            = &inet_dccp_ops,
 612         .capability     = -1,
 613         .no_check       = 0,
 614         .flags          = 0,
 615 };
 616
 617 /*
 618  * This is the global socket data structure used for responding to
 619  * the Out-of-the-blue (OOTB) packets. A control sock will be created
 620  * for this socket at the initialization time.
 621  */
 622 struct socket *dccp_ctl_socket;
 623
 624 static char dccp_ctl_socket_err_msg[] __initdata =
 625         KERN_ERR "DCCP: Failed to create the control socket.\n";
 626
 627 static int __init dccp_ctl_sock_init(void)
 628 {
 629         int rc = sock_create_kern(PF_INET, SOCK_DCCP, IPPROTO_DCCP,
 630                                   &dccp_ctl_socket);
 631         if (rc < 0)
 632                 printk(dccp_ctl_socket_err_msg);
 633         else {
 634                 dccp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
 635                 inet_sk(dccp_ctl_socket->sk)->uc_ttl = -1;
 636
 637                 /* Unhash it so that IP input processing does not even
 638                  * see it, we do not wish this socket to see incoming
 639                  * packets.
 640                  */
 641                 dccp_ctl_socket->sk->sk_prot->unhash(dccp_ctl_socket->sk);
 642         }
 643
 644         return rc;
 645 }
 646
 647 static void __exit dccp_ctl_sock_exit(void)
 648 {
 649         if (dccp_ctl_socket != NULL)
 650                 sock_release(dccp_ctl_socket);
 651 }
 652
 653 static int __init init_dccp_v4_mibs(void)
 654 {
 655         int rc = -ENOMEM;
 656
 657         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 658         if (dccp_statistics[0] == NULL)
 659                 goto out;
 660
 661         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 662         if (dccp_statistics[1] == NULL)
 663                 goto out_free_one;
 664
 665         rc = 0;
 666 out:
 667         return rc;
 668 out_free_one:
 669         free_percpu(dccp_statistics[0]);
 670         dccp_statistics[0] = NULL;
 671         goto out;
 672
 673 }
 674
 675 static int thash_entries;
 676 module_param(thash_entries, int, 0444);
 677 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 678
 679 int dccp_debug;
 680 module_param(dccp_debug, int, 0444);
 681 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 682
 683 static int __init dccp_init(void)
 684 {
 685         unsigned long goal;
 686         int ehash_order, bhash_order, i;
 687         int rc = proto_register(&dccp_v4_prot, 1);
 688
 689         if (rc)
 690                 goto out;
 691
 692         dccp_hashinfo.bind_bucket_cachep = kmem_cache_create("dccp_bind_bucket",
 693                                                sizeof(struct inet_bind_bucket),
 694                                                0, SLAB_HWCACHE_ALIGN,
 695                                                NULL, NULL);
 696         if (!dccp_hashinfo.bind_bucket_cachep)
 697                 goto out_proto_unregister;
 698
 699         /*
 700          * Size and allocate the main established and bind bucket
 701          * hash tables.
 702          *
 703          * The methodology is similar to that of the buffer cache.
 704          */
 705         if (num_physpages >= (128 * 1024))
 706                 goal = num_physpages >> (21 - PAGE_SHIFT);
 707         else
 708                 goal = num_physpages >> (23 - PAGE_SHIFT);
 709
 710         if (thash_entries)
 711                 goal = (thash_entries * sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
 712         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
 713                 ;
 714         do {
 715                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
 716                                         sizeof(struct inet_ehash_bucket);
 717                 dccp_hashinfo.ehash_size >>= 1;
 718                 while (dccp_hashinfo.ehash_size & (dccp_hashinfo.ehash_size - 1))
 719                         dccp_hashinfo.ehash_size--;
 720                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
 721                         __get_free_pages(GFP_ATOMIC, ehash_order);
 722         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
 723
 724         if (!dccp_hashinfo.ehash) {
 725                 printk(KERN_CRIT "Failed to allocate DCCP "
 726                                  "established hash table\n");
 727                 goto out_free_bind_bucket_cachep;
 728         }
 729
 730         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
 731                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
 732                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
 733         }
 734
 735         bhash_order = ehash_order;
 736
 737         do {
 738                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
 739                                         sizeof(struct inet_bind_hashbucket);
 740                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && bhash_order > 0)
 741                         continue;
 742                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
 743                         __get_free_pages(GFP_ATOMIC, bhash_order);
 744         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
 745
 746         if (!dccp_hashinfo.bhash) {
 747                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
 748                 goto out_free_dccp_ehash;
 749         }
 750
 751         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 752                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 753                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
 754         }
 755
 756         if (init_dccp_v4_mibs())
 757                 goto out_free_dccp_bhash;
 758
 759         rc = -EAGAIN;
 760         if (inet_add_protocol(&dccp_protocol, IPPROTO_DCCP))
 761                 goto out_free_dccp_v4_mibs;
 762
 763         inet_register_protosw(&dccp_v4_protosw);
 764
 765         rc = dccp_ctl_sock_init();
 766         if (rc)
 767                 goto out_unregister_protosw;
 768 out:
 769         return rc;
 770 out_unregister_protosw:
 771         inet_unregister_protosw(&dccp_v4_protosw);
 772         inet_del_protocol(&dccp_protocol, IPPROTO_DCCP);
 773 out_free_dccp_v4_mibs:
 774         free_percpu(dccp_statistics[0]);
 775         free_percpu(dccp_statistics[1]);
 776         dccp_statistics[0] = dccp_statistics[1] = NULL;
 777 out_free_dccp_bhash:
 778         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 779         dccp_hashinfo.bhash = NULL;
 780 out_free_dccp_ehash:
 781         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 782         dccp_hashinfo.ehash = NULL;
 783 out_free_bind_bucket_cachep:
 784         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 785         dccp_hashinfo.bind_bucket_cachep = NULL;
 786 out_proto_unregister:
 787         proto_unregister(&dccp_v4_prot);
 788         goto out;
 789 }
 790
 791 static const char dccp_del_proto_err_msg[] __exitdata =
 792         KERN_ERR "can't remove dccp net_protocol\n";
 793
 794 static void __exit dccp_fini(void)
 795 {
 796         dccp_ctl_sock_exit();
 797
 798         inet_unregister_protosw(&dccp_v4_protosw);
 799
 800         if (inet_del_protocol(&dccp_protocol, IPPROTO_DCCP) < 0)
 801                 printk(dccp_del_proto_err_msg);
 802
 803         /* Free the control endpoint.  */
 804         sock_release(dccp_ctl_socket);
 805
 806         proto_unregister(&dccp_v4_prot);
 807
 808         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 809 }
 810
 811 module_init(dccp_init);
 812 module_exit(dccp_fini);
 813
 814 /* __stringify doesn't likes enums, so use SOCK_DCCP (6) value directly  */
 815 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-6");
 816 MODULE_LICENSE("GPL");
 817 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
 818 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");