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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/dccp.h>
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/in.h>
  20 #include <linux/if_arp.h>
  21 #include <linux/init.h>
  22 #include <linux/random.h>
  23 #include <net/checksum.h>
  24
  25 #include <net/inet_sock.h>
  26 #include <net/sock.h>
  27 #include <net/xfrm.h>
  28
  29 #include <asm/ioctls.h>
  30 #include <asm/semaphore.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/timer.h>
  33 #include <linux/delay.h>
  34 #include <linux/poll.h>
  35
  36 #include "ccid.h"
  37 #include "dccp.h"
  38 #include "feat.h"
  39
  40 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
  41
  42 EXPORT_SYMBOL_GPL(dccp_statistics);
  43
  44 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
  45
  46 EXPORT_SYMBOL_GPL(dccp_orphan_count);
  47
  48 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
  49         .lhash_lock     = RW_LOCK_UNLOCKED,
  50         .lhash_users    = ATOMIC_INIT(0),
  51         .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
  52 };
  53
  54 EXPORT_SYMBOL_GPL(dccp_hashinfo);
  55
  56 /* the maximum queue length for tx in packets. 0 is no limit */
  57 int sysctl_dccp_tx_qlen __read_mostly = 5;
  58
  59 void dccp_set_state(struct sock *sk, const int state)
  60 {
  61         const int oldstate = sk->sk_state;
  62
  63         dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
  64                       dccp_state_name(oldstate), dccp_state_name(state));
  65         WARN_ON(state == oldstate);
  66
  67         switch (state) {
  68         case DCCP_OPEN:
  69                 if (oldstate != DCCP_OPEN)
  70                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  71                 break;
  72
  73         case DCCP_CLOSED:
  74                 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
  75                     oldstate == DCCP_CLOSING)
  76                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  77
  78                 sk->sk_prot->unhash(sk);
  79                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
  80                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
  81                         inet_put_port(sk);
  82                 /* fall through */
  83         default:
  84                 if (oldstate == DCCP_OPEN)
  85                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
  86         }
  87
  88         /* Change state AFTER socket is unhashed to avoid closed
  89          * socket sitting in hash tables.
  90          */
  91         sk->sk_state = state;
  92 }
  93
  94 EXPORT_SYMBOL_GPL(dccp_set_state);
  95
  96 static void dccp_finish_passive_close(struct sock *sk)
  97 {
  98         switch (sk->sk_state) {
  99         case DCCP_PASSIVE_CLOSE:
 100                 /* Node (client or server) has received Close packet. */
 101                 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
 102                 dccp_set_state(sk, DCCP_CLOSED);
 103                 break;
 104         case DCCP_PASSIVE_CLOSEREQ:
 105                 /*
 106                  * Client received CloseReq. We set the `active' flag so that
 107                  * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
 108                  */
 109                 dccp_send_close(sk, 1);
 110                 dccp_set_state(sk, DCCP_CLOSING);
 111         }
 112 }
 113
 114 void dccp_done(struct sock *sk)
 115 {
 116         dccp_set_state(sk, DCCP_CLOSED);
 117         dccp_clear_xmit_timers(sk);
 118
 119         sk->sk_shutdown = SHUTDOWN_MASK;
 120
 121         if (!sock_flag(sk, SOCK_DEAD))
 122                 sk->sk_state_change(sk);
 123         else
 124                 inet_csk_destroy_sock(sk);
 125 }
 126
 127 EXPORT_SYMBOL_GPL(dccp_done);
 128
 129 const char *dccp_packet_name(const int type)
 130 {
 131         static const char *dccp_packet_names[] = {
 132                 [DCCP_PKT_REQUEST]  = "REQUEST",
 133                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 134                 [DCCP_PKT_DATA]     = "DATA",
 135                 [DCCP_PKT_ACK]      = "ACK",
 136                 [DCCP_PKT_DATAACK]  = "DATAACK",
 137                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 138                 [DCCP_PKT_CLOSE]    = "CLOSE",
 139                 [DCCP_PKT_RESET]    = "RESET",
 140                 [DCCP_PKT_SYNC]     = "SYNC",
 141                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 142         };
 143
 144         if (type >= DCCP_NR_PKT_TYPES)
 145                 return "INVALID";
 146         else
 147                 return dccp_packet_names[type];
 148 }
 149
 150 EXPORT_SYMBOL_GPL(dccp_packet_name);
 151
 152 const char *dccp_state_name(const int state)
 153 {
 154         static char *dccp_state_names[] = {
 155         [DCCP_OPEN]             = "OPEN",
 156         [DCCP_REQUESTING]       = "REQUESTING",
 157         [DCCP_PARTOPEN]         = "PARTOPEN",
 158         [DCCP_LISTEN]           = "LISTEN",
 159         [DCCP_RESPOND]          = "RESPOND",
 160         [DCCP_CLOSING]          = "CLOSING",
 161         [DCCP_ACTIVE_CLOSEREQ]  = "CLOSEREQ",
 162         [DCCP_PASSIVE_CLOSE]    = "PASSIVE_CLOSE",
 163         [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
 164         [DCCP_TIME_WAIT]        = "TIME_WAIT",
 165         [DCCP_CLOSED]           = "CLOSED",
 166         };
 167
 168         if (state >= DCCP_MAX_STATES)
 169                 return "INVALID STATE!";
 170         else
 171                 return dccp_state_names[state];
 172 }
 173
 174 EXPORT_SYMBOL_GPL(dccp_state_name);
 175
 176 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 177 {
 178         struct dccp_sock *dp = dccp_sk(sk);
 179         struct dccp_minisock *dmsk = dccp_msk(sk);
 180         struct inet_connection_sock *icsk = inet_csk(sk);
 181
 182         dccp_minisock_init(&dp->dccps_minisock);
 183
 184         icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 185         icsk->icsk_syn_retries  = sysctl_dccp_request_retries;
 186         sk->sk_state            = DCCP_CLOSED;
 187         sk->sk_write_space      = dccp_write_space;
 188         icsk->icsk_sync_mss     = dccp_sync_mss;
 189         dp->dccps_mss_cache     = 536;
 190         dp->dccps_rate_last     = jiffies;
 191         dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 192         dp->dccps_service       = DCCP_SERVICE_CODE_IS_ABSENT;
 193         dp->dccps_l_ack_ratio   = dp->dccps_r_ack_ratio = 1;
 194
 195         dccp_init_xmit_timers(sk);
 196
 197         /*
 198          * FIXME: We're hardcoding the CCID, and doing this at this point makes
 199          * the listening (master) sock get CCID control blocks, which is not
 200          * necessary, but for now, to not mess with the test userspace apps,
 201          * lets leave it here, later the real solution is to do this in a
 202          * setsockopt(CCIDs-I-want/accept). -acme
 203          */
 204         if (likely(ctl_sock_initialized)) {
 205                 int rc = dccp_feat_init(dmsk);
 206
 207                 if (rc)
 208                         return rc;
 209
 210                 if (dmsk->dccpms_send_ack_vector) {
 211                         dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
 212                         if (dp->dccps_hc_rx_ackvec == NULL)
 213                                 return -ENOMEM;
 214                 }
 215                 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
 216                                                       sk, GFP_KERNEL);
 217                 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
 218                                                       sk, GFP_KERNEL);
 219                 if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
 220                              dp->dccps_hc_tx_ccid == NULL)) {
 221                         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 222                         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 223                         if (dmsk->dccpms_send_ack_vector) {
 224                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 225                                 dp->dccps_hc_rx_ackvec = NULL;
 226                         }
 227                         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 228                         return -ENOMEM;
 229                 }
 230         } else {
 231                 /* control socket doesn't need feat nego */
 232                 INIT_LIST_HEAD(&dmsk->dccpms_pending);
 233                 INIT_LIST_HEAD(&dmsk->dccpms_conf);
 234         }
 235
 236         return 0;
 237 }
 238
 239 EXPORT_SYMBOL_GPL(dccp_init_sock);
 240
 241 int dccp_destroy_sock(struct sock *sk)
 242 {
 243         struct dccp_sock *dp = dccp_sk(sk);
 244         struct dccp_minisock *dmsk = dccp_msk(sk);
 245
 246         /*
 247          * DCCP doesn't use sk_write_queue, just sk_send_head
 248          * for retransmissions
 249          */
 250         if (sk->sk_send_head != NULL) {
 251                 kfree_skb(sk->sk_send_head);
 252                 sk->sk_send_head = NULL;
 253         }
 254
 255         /* Clean up a referenced DCCP bind bucket. */
 256         if (inet_csk(sk)->icsk_bind_hash != NULL)
 257                 inet_put_port(sk);
 258
 259         kfree(dp->dccps_service_list);
 260         dp->dccps_service_list = NULL;
 261
 262         if (dmsk->dccpms_send_ack_vector) {
 263                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 264                 dp->dccps_hc_rx_ackvec = NULL;
 265         }
 266         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 267         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 268         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 269
 270         /* clean up feature negotiation state */
 271         dccp_feat_clean(dmsk);
 272
 273         return 0;
 274 }
 275
 276 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 277
 278 static inline int dccp_listen_start(struct sock *sk, int backlog)
 279 {
 280         struct dccp_sock *dp = dccp_sk(sk);
 281
 282         dp->dccps_role = DCCP_ROLE_LISTEN;
 283         return inet_csk_listen_start(sk, backlog);
 284 }
 285
 286 static inline int dccp_need_reset(int state)
 287 {
 288         return state != DCCP_CLOSED && state != DCCP_LISTEN &&
 289                state != DCCP_REQUESTING;
 290 }
 291
 292 int dccp_disconnect(struct sock *sk, int flags)
 293 {
 294         struct inet_connection_sock *icsk = inet_csk(sk);
 295         struct inet_sock *inet = inet_sk(sk);
 296         int err = 0;
 297         const int old_state = sk->sk_state;
 298
 299         if (old_state != DCCP_CLOSED)
 300                 dccp_set_state(sk, DCCP_CLOSED);
 301
 302         /*
 303          * This corresponds to the ABORT function of RFC793, sec. 3.8
 304          * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
 305          */
 306         if (old_state == DCCP_LISTEN) {
 307                 inet_csk_listen_stop(sk);
 308         } else if (dccp_need_reset(old_state)) {
 309                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 310                 sk->sk_err = ECONNRESET;
 311         } else if (old_state == DCCP_REQUESTING)
 312                 sk->sk_err = ECONNRESET;
 313
 314         dccp_clear_xmit_timers(sk);
 315         __skb_queue_purge(&sk->sk_receive_queue);
 316         if (sk->sk_send_head != NULL) {
 317                 __kfree_skb(sk->sk_send_head);
 318                 sk->sk_send_head = NULL;
 319         }
 320
 321         inet->dport = 0;
 322
 323         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 324                 inet_reset_saddr(sk);
 325
 326         sk->sk_shutdown = 0;
 327         sock_reset_flag(sk, SOCK_DONE);
 328
 329         icsk->icsk_backoff = 0;
 330         inet_csk_delack_init(sk);
 331         __sk_dst_reset(sk);
 332
 333         BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
 334
 335         sk->sk_error_report(sk);
 336         return err;
 337 }
 338
 339 EXPORT_SYMBOL_GPL(dccp_disconnect);
 340
 341 /*
 342  *      Wait for a DCCP event.
 343  *
 344  *      Note that we don't need to lock the socket, as the upper poll layers
 345  *      take care of normal races (between the test and the event) and we don't
 346  *      go look at any of the socket buffers directly.
 347  */
 348 unsigned int dccp_poll(struct file *file, struct socket *sock,
 349                        poll_table *wait)
 350 {
 351         unsigned int mask;
 352         struct sock *sk = sock->sk;
 353
 354         poll_wait(file, sk->sk_sleep, wait);
 355         if (sk->sk_state == DCCP_LISTEN)
 356                 return inet_csk_listen_poll(sk);
 357
 358         /* Socket is not locked. We are protected from async events
 359            by poll logic and correct handling of state changes
 360            made by another threads is impossible in any case.
 361          */
 362
 363         mask = 0;
 364         if (sk->sk_err)
 365                 mask = POLLERR;
 366
 367         if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
 368                 mask |= POLLHUP;
 369         if (sk->sk_shutdown & RCV_SHUTDOWN)
 370                 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 371
 372         /* Connected? */
 373         if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 374                 if (atomic_read(&sk->sk_rmem_alloc) > 0)
 375                         mask |= POLLIN | POLLRDNORM;
 376
 377                 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 378                         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 379                                 mask |= POLLOUT | POLLWRNORM;
 380                         } else {  /* send SIGIO later */
 381                                 set_bit(SOCK_ASYNC_NOSPACE,
 382                                         &sk->sk_socket->flags);
 383                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 384
 385                                 /* Race breaker. If space is freed after
 386                                  * wspace test but before the flags are set,
 387                                  * IO signal will be lost.
 388                                  */
 389                                 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
 390                                         mask |= POLLOUT | POLLWRNORM;
 391                         }
 392                 }
 393         }
 394         return mask;
 395 }
 396
 397 EXPORT_SYMBOL_GPL(dccp_poll);
 398
 399 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 400 {
 401         int rc = -ENOTCONN;
 402
 403         lock_sock(sk);
 404
 405         if (sk->sk_state == DCCP_LISTEN)
 406                 goto out;
 407
 408         switch (cmd) {
 409         case SIOCINQ: {
 410                 struct sk_buff *skb;
 411                 unsigned long amount = 0;
 412
 413                 skb = skb_peek(&sk->sk_receive_queue);
 414                 if (skb != NULL) {
 415                         /*
 416                          * We will only return the amount of this packet since
 417                          * that is all that will be read.
 418                          */
 419                         amount = skb->len;
 420                 }
 421                 rc = put_user(amount, (int __user *)arg);
 422         }
 423                 break;
 424         default:
 425                 rc = -ENOIOCTLCMD;
 426                 break;
 427         }
 428 out:
 429         release_sock(sk);
 430         return rc;
 431 }
 432
 433 EXPORT_SYMBOL_GPL(dccp_ioctl);
 434
 435 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 436                                    char __user *optval, int optlen)
 437 {
 438         struct dccp_sock *dp = dccp_sk(sk);
 439         struct dccp_service_list *sl = NULL;
 440
 441         if (service == DCCP_SERVICE_INVALID_VALUE ||
 442             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 443                 return -EINVAL;
 444
 445         if (optlen > sizeof(service)) {
 446                 sl = kmalloc(optlen, GFP_KERNEL);
 447                 if (sl == NULL)
 448                         return -ENOMEM;
 449
 450                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 451                 if (copy_from_user(sl->dccpsl_list,
 452                                    optval + sizeof(service),
 453                                    optlen - sizeof(service)) ||
 454                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 455                         kfree(sl);
 456                         return -EFAULT;
 457                 }
 458         }
 459
 460         lock_sock(sk);
 461         dp->dccps_service = service;
 462
 463         kfree(dp->dccps_service_list);
 464
 465         dp->dccps_service_list = sl;
 466         release_sock(sk);
 467         return 0;
 468 }
 469
 470 /* byte 1 is feature.  the rest is the preference list */
 471 static int dccp_setsockopt_change(struct sock *sk, int type,
 472                                   struct dccp_so_feat __user *optval)
 473 {
 474         struct dccp_so_feat opt;
 475         u8 *val;
 476         int rc;
 477
 478         if (copy_from_user(&opt, optval, sizeof(opt)))
 479                 return -EFAULT;
 480
 481         val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
 482         if (!val)
 483                 return -ENOMEM;
 484
 485         if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
 486                 rc = -EFAULT;
 487                 goto out_free_val;
 488         }
 489
 490         rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
 491                               val, opt.dccpsf_len, GFP_KERNEL);
 492         if (rc)
 493                 goto out_free_val;
 494
 495 out:
 496         return rc;
 497
 498 out_free_val:
 499         kfree(val);
 500         goto out;
 501 }
 502
 503 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 504                 char __user *optval, int optlen)
 505 {
 506         struct dccp_sock *dp = dccp_sk(sk);
 507         int val, err = 0;
 508
 509         if (optlen < sizeof(int))
 510                 return -EINVAL;
 511
 512         if (get_user(val, (int __user *)optval))
 513                 return -EFAULT;
 514
 515         if (optname == DCCP_SOCKOPT_SERVICE)
 516                 return dccp_setsockopt_service(sk, val, optval, optlen);
 517
 518         lock_sock(sk);
 519         switch (optname) {
 520         case DCCP_SOCKOPT_PACKET_SIZE:
 521                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 522                 err = 0;
 523                 break;
 524         case DCCP_SOCKOPT_CHANGE_L:
 525                 if (optlen != sizeof(struct dccp_so_feat))
 526                         err = -EINVAL;
 527                 else
 528                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
 529                                                      (struct dccp_so_feat __user *)
 530                                                      optval);
 531                 break;
 532         case DCCP_SOCKOPT_CHANGE_R:
 533                 if (optlen != sizeof(struct dccp_so_feat))
 534                         err = -EINVAL;
 535                 else
 536                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
 537                                                      (struct dccp_so_feat __user *)
 538                                                      optval);
 539                 break;
 540         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 541                 if (dp->dccps_role != DCCP_ROLE_SERVER)
 542                         err = -EOPNOTSUPP;
 543                 else
 544                         dp->dccps_server_timewait = (val != 0);
 545                 break;
 546         case DCCP_SOCKOPT_SEND_CSCOV:   /* sender side, RFC 4340, sec. 9.2 */
 547                 if (val < 0 || val > 15)
 548                         err = -EINVAL;
 549                 else
 550                         dp->dccps_pcslen = val;
 551                 break;
 552         case DCCP_SOCKOPT_RECV_CSCOV:   /* receiver side, RFC 4340 sec. 9.2.1 */
 553                 if (val < 0 || val > 15)
 554                         err = -EINVAL;
 555                 else {
 556                         dp->dccps_pcrlen = val;
 557                         /* FIXME: add feature negotiation,
 558                          * ChangeL(MinimumChecksumCoverage, val) */
 559                 }
 560                 break;
 561         default:
 562                 err = -ENOPROTOOPT;
 563                 break;
 564         }
 565
 566         release_sock(sk);
 567         return err;
 568 }
 569
 570 int dccp_setsockopt(struct sock *sk, int level, int optname,
 571                     char __user *optval, int optlen)
 572 {
 573         if (level != SOL_DCCP)
 574                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 575                                                              optname, optval,
 576                                                              optlen);
 577         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 578 }
 579
 580 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 581
 582 #ifdef CONFIG_COMPAT
 583 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 584                            char __user *optval, int optlen)
 585 {
 586         if (level != SOL_DCCP)
 587                 return inet_csk_compat_setsockopt(sk, level, optname,
 588                                                   optval, optlen);
 589         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 590 }
 591
 592 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 593 #endif
 594
 595 static int dccp_getsockopt_service(struct sock *sk, int len,
 596                                    __be32 __user *optval,
 597                                    int __user *optlen)
 598 {
 599         const struct dccp_sock *dp = dccp_sk(sk);
 600         const struct dccp_service_list *sl;
 601         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 602
 603         lock_sock(sk);
 604         if ((sl = dp->dccps_service_list) != NULL) {
 605                 slen = sl->dccpsl_nr * sizeof(u32);
 606                 total_len += slen;
 607         }
 608
 609         err = -EINVAL;
 610         if (total_len > len)
 611                 goto out;
 612
 613         err = 0;
 614         if (put_user(total_len, optlen) ||
 615             put_user(dp->dccps_service, optval) ||
 616             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 617                 err = -EFAULT;
 618 out:
 619         release_sock(sk);
 620         return err;
 621 }
 622
 623 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 624                     char __user *optval, int __user *optlen)
 625 {
 626         struct dccp_sock *dp;
 627         int val, len;
 628
 629         if (get_user(len, optlen))
 630                 return -EFAULT;
 631
 632         if (len < (int)sizeof(int))
 633                 return -EINVAL;
 634
 635         dp = dccp_sk(sk);
 636
 637         switch (optname) {
 638         case DCCP_SOCKOPT_PACKET_SIZE:
 639                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 640                 return 0;
 641         case DCCP_SOCKOPT_SERVICE:
 642                 return dccp_getsockopt_service(sk, len,
 643                                                (__be32 __user *)optval, optlen);
 644         case DCCP_SOCKOPT_GET_CUR_MPS:
 645                 val = dp->dccps_mss_cache;
 646                 break;
 647         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 648                 val = dp->dccps_server_timewait;
 649                 break;
 650         case DCCP_SOCKOPT_SEND_CSCOV:
 651                 val = dp->dccps_pcslen;
 652                 break;
 653         case DCCP_SOCKOPT_RECV_CSCOV:
 654                 val = dp->dccps_pcrlen;
 655                 break;
 656         case 128 ... 191:
 657                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 658                                              len, (u32 __user *)optval, optlen);
 659         case 192 ... 255:
 660                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 661                                              len, (u32 __user *)optval, optlen);
 662         default:
 663                 return -ENOPROTOOPT;
 664         }
 665
 666         len = sizeof(val);
 667         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 668                 return -EFAULT;
 669
 670         return 0;
 671 }
 672
 673 int dccp_getsockopt(struct sock *sk, int level, int optname,
 674                     char __user *optval, int __user *optlen)
 675 {
 676         if (level != SOL_DCCP)
 677                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 678                                                              optname, optval,
 679                                                              optlen);
 680         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 681 }
 682
 683 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 684
 685 #ifdef CONFIG_COMPAT
 686 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 687                            char __user *optval, int __user *optlen)
 688 {
 689         if (level != SOL_DCCP)
 690                 return inet_csk_compat_getsockopt(sk, level, optname,
 691                                                   optval, optlen);
 692         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 693 }
 694
 695 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 696 #endif
 697
 698 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 699                  size_t len)
 700 {
 701         const struct dccp_sock *dp = dccp_sk(sk);
 702         const int flags = msg->msg_flags;
 703         const int noblock = flags & MSG_DONTWAIT;
 704         struct sk_buff *skb;
 705         int rc, size;
 706         long timeo;
 707
 708         if (len > dp->dccps_mss_cache)
 709                 return -EMSGSIZE;
 710
 711         lock_sock(sk);
 712
 713         if (sysctl_dccp_tx_qlen &&
 714             (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
 715                 rc = -EAGAIN;
 716                 goto out_release;
 717         }
 718
 719         timeo = sock_sndtimeo(sk, noblock);
 720
 721         /*
 722          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 723          * so that the trick in dccp_rcv_request_sent_state_process.
 724          */
 725         /* Wait for a connection to finish. */
 726         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 727                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 728                         goto out_release;
 729
 730         size = sk->sk_prot->max_header + len;
 731         release_sock(sk);
 732         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 733         lock_sock(sk);
 734         if (skb == NULL)
 735                 goto out_release;
 736
 737         skb_reserve(skb, sk->sk_prot->max_header);
 738         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 739         if (rc != 0)
 740                 goto out_discard;
 741
 742         skb_queue_tail(&sk->sk_write_queue, skb);
 743         dccp_write_xmit(sk,0);
 744 out_release:
 745         release_sock(sk);
 746         return rc ? : len;
 747 out_discard:
 748         kfree_skb(skb);
 749         goto out_release;
 750 }
 751
 752 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 753
 754 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 755                  size_t len, int nonblock, int flags, int *addr_len)
 756 {
 757         const struct dccp_hdr *dh;
 758         long timeo;
 759
 760         lock_sock(sk);
 761
 762         if (sk->sk_state == DCCP_LISTEN) {
 763                 len = -ENOTCONN;
 764                 goto out;
 765         }
 766
 767         timeo = sock_rcvtimeo(sk, nonblock);
 768
 769         do {
 770                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 771
 772                 if (skb == NULL)
 773                         goto verify_sock_status;
 774
 775                 dh = dccp_hdr(skb);
 776
 777                 switch (dh->dccph_type) {
 778                 case DCCP_PKT_DATA:
 779                 case DCCP_PKT_DATAACK:
 780                         goto found_ok_skb;
 781
 782                 case DCCP_PKT_CLOSE:
 783                 case DCCP_PKT_CLOSEREQ:
 784                         if (!(flags & MSG_PEEK))
 785                                 dccp_finish_passive_close(sk);
 786                         /* fall through */
 787                 case DCCP_PKT_RESET:
 788                         dccp_pr_debug("found fin (%s) ok!\n",
 789                                       dccp_packet_name(dh->dccph_type));
 790                         len = 0;
 791                         goto found_fin_ok;
 792                 default:
 793                         dccp_pr_debug("packet_type=%s\n",
 794                                       dccp_packet_name(dh->dccph_type));
 795                         sk_eat_skb(sk, skb, 0);
 796                 }
 797 verify_sock_status:
 798                 if (sock_flag(sk, SOCK_DONE)) {
 799                         len = 0;
 800                         break;
 801                 }
 802
 803                 if (sk->sk_err) {
 804                         len = sock_error(sk);
 805                         break;
 806                 }
 807
 808                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 809                         len = 0;
 810                         break;
 811                 }
 812
 813                 if (sk->sk_state == DCCP_CLOSED) {
 814                         if (!sock_flag(sk, SOCK_DONE)) {
 815                                 /* This occurs when user tries to read
 816                                  * from never connected socket.
 817                                  */
 818                                 len = -ENOTCONN;
 819                                 break;
 820                         }
 821                         len = 0;
 822                         break;
 823                 }
 824
 825                 if (!timeo) {
 826                         len = -EAGAIN;
 827                         break;
 828                 }
 829
 830                 if (signal_pending(current)) {
 831                         len = sock_intr_errno(timeo);
 832                         break;
 833                 }
 834
 835                 sk_wait_data(sk, &timeo);
 836                 continue;
 837         found_ok_skb:
 838                 if (len > skb->len)
 839                         len = skb->len;
 840                 else if (len < skb->len)
 841                         msg->msg_flags |= MSG_TRUNC;
 842
 843                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 844                         /* Exception. Bailout! */
 845                         len = -EFAULT;
 846                         break;
 847                 }
 848         found_fin_ok:
 849                 if (!(flags & MSG_PEEK))
 850                         sk_eat_skb(sk, skb, 0);
 851                 break;
 852         } while (1);
 853 out:
 854         release_sock(sk);
 855         return len;
 856 }
 857
 858 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 859
 860 int inet_dccp_listen(struct socket *sock, int backlog)
 861 {
 862         struct sock *sk = sock->sk;
 863         unsigned char old_state;
 864         int err;
 865
 866         lock_sock(sk);
 867
 868         err = -EINVAL;
 869         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 870                 goto out;
 871
 872         old_state = sk->sk_state;
 873         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 874                 goto out;
 875
 876         /* Really, if the socket is already in listen state
 877          * we can only allow the backlog to be adjusted.
 878          */
 879         if (old_state != DCCP_LISTEN) {
 880                 /*
 881                  * FIXME: here it probably should be sk->sk_prot->listen_start
 882                  * see tcp_listen_start
 883                  */
 884                 err = dccp_listen_start(sk, backlog);
 885                 if (err)
 886                         goto out;
 887         }
 888         sk->sk_max_ack_backlog = backlog;
 889         err = 0;
 890
 891 out:
 892         release_sock(sk);
 893         return err;
 894 }
 895
 896 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 897
 898 static void dccp_terminate_connection(struct sock *sk)
 899 {
 900         u8 next_state = DCCP_CLOSED;
 901
 902         switch (sk->sk_state) {
 903         case DCCP_PASSIVE_CLOSE:
 904         case DCCP_PASSIVE_CLOSEREQ:
 905                 dccp_finish_passive_close(sk);
 906                 break;
 907         case DCCP_PARTOPEN:
 908                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 909                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 910                 /* fall through */
 911         case DCCP_OPEN:
 912                 dccp_send_close(sk, 1);
 913
 914                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 915                     !dccp_sk(sk)->dccps_server_timewait)
 916                         next_state = DCCP_ACTIVE_CLOSEREQ;
 917                 else
 918                         next_state = DCCP_CLOSING;
 919                 /* fall through */
 920         default:
 921                 dccp_set_state(sk, next_state);
 922         }
 923 }
 924
 925 void dccp_close(struct sock *sk, long timeout)
 926 {
 927         struct dccp_sock *dp = dccp_sk(sk);
 928         struct sk_buff *skb;
 929         u32 data_was_unread = 0;
 930         int state;
 931
 932         lock_sock(sk);
 933
 934         sk->sk_shutdown = SHUTDOWN_MASK;
 935
 936         if (sk->sk_state == DCCP_LISTEN) {
 937                 dccp_set_state(sk, DCCP_CLOSED);
 938
 939                 /* Special case. */
 940                 inet_csk_listen_stop(sk);
 941
 942                 goto adjudge_to_death;
 943         }
 944
 945         sk_stop_timer(sk, &dp->dccps_xmit_timer);
 946
 947         /*
 948          * We need to flush the recv. buffs.  We do this only on the
 949          * descriptor close, not protocol-sourced closes, because the
 950           *reader process may not have drained the data yet!
 951          */
 952         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 953                 data_was_unread += skb->len;
 954                 __kfree_skb(skb);
 955         }
 956
 957         if (data_was_unread) {
 958                 /* Unread data was tossed, send an appropriate Reset Code */
 959                 DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
 960                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 961                 dccp_set_state(sk, DCCP_CLOSED);
 962         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 963                 /* Check zero linger _after_ checking for unread data. */
 964                 sk->sk_prot->disconnect(sk, 0);
 965         } else if (sk->sk_state != DCCP_CLOSED) {
 966                 dccp_terminate_connection(sk);
 967         }
 968
 969         sk_stream_wait_close(sk, timeout);
 970
 971 adjudge_to_death:
 972         state = sk->sk_state;
 973         sock_hold(sk);
 974         sock_orphan(sk);
 975         atomic_inc(sk->sk_prot->orphan_count);
 976
 977         /*
 978          * It is the last release_sock in its life. It will remove backlog.
 979          */
 980         release_sock(sk);
 981         /*
 982          * Now socket is owned by kernel and we acquire BH lock
 983          * to finish close. No need to check for user refs.
 984          */
 985         local_bh_disable();
 986         bh_lock_sock(sk);
 987         BUG_TRAP(!sock_owned_by_user(sk));
 988
 989         /* Have we already been destroyed by a softirq or backlog? */
 990         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
 991                 goto out;
 992
 993         if (sk->sk_state == DCCP_CLOSED)
 994                 inet_csk_destroy_sock(sk);
 995
 996         /* Otherwise, socket is reprieved until protocol close. */
 997
 998 out:
 999         bh_unlock_sock(sk);
1000         local_bh_enable();
1001         sock_put(sk);
1002 }
1003
1004 EXPORT_SYMBOL_GPL(dccp_close);
1005
1006 void dccp_shutdown(struct sock *sk, int how)
1007 {
1008         dccp_pr_debug("called shutdown(%x)\n", how);
1009 }
1010
1011 EXPORT_SYMBOL_GPL(dccp_shutdown);
1012
1013 static int __init dccp_mib_init(void)
1014 {
1015         int rc = -ENOMEM;
1016
1017         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
1018         if (dccp_statistics[0] == NULL)
1019                 goto out;
1020
1021         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
1022         if (dccp_statistics[1] == NULL)
1023                 goto out_free_one;
1024
1025         rc = 0;
1026 out:
1027         return rc;
1028 out_free_one:
1029         free_percpu(dccp_statistics[0]);
1030         dccp_statistics[0] = NULL;
1031         goto out;
1032
1033 }
1034
1035 static void dccp_mib_exit(void)
1036 {
1037         free_percpu(dccp_statistics[0]);
1038         free_percpu(dccp_statistics[1]);
1039         dccp_statistics[0] = dccp_statistics[1] = NULL;
1040 }
1041
1042 static int thash_entries;
1043 module_param(thash_entries, int, 0444);
1044 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1045
1046 #ifdef CONFIG_IP_DCCP_DEBUG
1047 int dccp_debug;
1048 module_param(dccp_debug, bool, 0444);
1049 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1050
1051 EXPORT_SYMBOL_GPL(dccp_debug);
1052 #endif
1053
1054 static int __init dccp_init(void)
1055 {
1056         unsigned long goal;
1057         int ehash_order, bhash_order, i;
1058         int rc = -ENOBUFS;
1059
1060         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1061                      FIELD_SIZEOF(struct sk_buff, cb));
1062
1063         dccp_hashinfo.bind_bucket_cachep =
1064                 kmem_cache_create("dccp_bind_bucket",
1065                                   sizeof(struct inet_bind_bucket), 0,
1066                                   SLAB_HWCACHE_ALIGN, NULL);
1067         if (!dccp_hashinfo.bind_bucket_cachep)
1068                 goto out;
1069
1070         /*
1071          * Size and allocate the main established and bind bucket
1072          * hash tables.
1073          *
1074          * The methodology is similar to that of the buffer cache.
1075          */
1076         if (num_physpages >= (128 * 1024))
1077                 goal = num_physpages >> (21 - PAGE_SHIFT);
1078         else
1079                 goal = num_physpages >> (23 - PAGE_SHIFT);
1080
1081         if (thash_entries)
1082                 goal = (thash_entries *
1083                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1084         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1085                 ;
1086         do {
1087                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1088                                         sizeof(struct inet_ehash_bucket);
1089                 while (dccp_hashinfo.ehash_size &
1090                        (dccp_hashinfo.ehash_size - 1))
1091                         dccp_hashinfo.ehash_size--;
1092                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1093                         __get_free_pages(GFP_ATOMIC, ehash_order);
1094         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1095
1096         if (!dccp_hashinfo.ehash) {
1097                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1098                 goto out_free_bind_bucket_cachep;
1099         }
1100
1101         for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
1102                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
1103                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].twchain);
1104         }
1105
1106         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1107                         goto out_free_dccp_ehash;
1108
1109         bhash_order = ehash_order;
1110
1111         do {
1112                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1113                                         sizeof(struct inet_bind_hashbucket);
1114                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1115                     bhash_order > 0)
1116                         continue;
1117                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1118                         __get_free_pages(GFP_ATOMIC, bhash_order);
1119         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1120
1121         if (!dccp_hashinfo.bhash) {
1122                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1123                 goto out_free_dccp_locks;
1124         }
1125
1126         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1127                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1128                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1129         }
1130
1131         rc = dccp_mib_init();
1132         if (rc)
1133                 goto out_free_dccp_bhash;
1134
1135         rc = dccp_ackvec_init();
1136         if (rc)
1137                 goto out_free_dccp_mib;
1138
1139         rc = dccp_sysctl_init();
1140         if (rc)
1141                 goto out_ackvec_exit;
1142
1143         dccp_timestamping_init();
1144 out:
1145         return rc;
1146 out_ackvec_exit:
1147         dccp_ackvec_exit();
1148 out_free_dccp_mib:
1149         dccp_mib_exit();
1150 out_free_dccp_bhash:
1151         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1152         dccp_hashinfo.bhash = NULL;
1153 out_free_dccp_locks:
1154         inet_ehash_locks_free(&dccp_hashinfo);
1155 out_free_dccp_ehash:
1156         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1157         dccp_hashinfo.ehash = NULL;
1158 out_free_bind_bucket_cachep:
1159         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1160         dccp_hashinfo.bind_bucket_cachep = NULL;
1161         goto out;
1162 }
1163
1164 static void __exit dccp_fini(void)
1165 {
1166         dccp_mib_exit();
1167         free_pages((unsigned long)dccp_hashinfo.bhash,
1168                    get_order(dccp_hashinfo.bhash_size *
1169                              sizeof(struct inet_bind_hashbucket)));
1170         free_pages((unsigned long)dccp_hashinfo.ehash,
1171                    get_order(dccp_hashinfo.ehash_size *
1172                              sizeof(struct inet_ehash_bucket)));
1173         inet_ehash_locks_free(&dccp_hashinfo);
1174         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1175         dccp_ackvec_exit();
1176         dccp_sysctl_exit();
1177 }
1178
1179 module_init(dccp_init);
1180 module_exit(dccp_fini);
1181
1182 MODULE_LICENSE("GPL");
1183 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1184 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");