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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/semaphore.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/timer.h>
  32 #include <linux/delay.h>
  33 #include <linux/poll.h>
  34
  35 #include "ccid.h"
  36 #include "dccp.h"
  37 #include "feat.h"
  38
  39 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
  40
  41 EXPORT_SYMBOL_GPL(dccp_statistics);
  42
  43 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
  44
  45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
  46
  47 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
  48         .lhash_lock     = RW_LOCK_UNLOCKED,
  49         .lhash_users    = ATOMIC_INIT(0),
  50         .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
  51 };
  52
  53 EXPORT_SYMBOL_GPL(dccp_hashinfo);
  54
  55 /* the maximum queue length for tx in packets. 0 is no limit */
  56 int sysctl_dccp_tx_qlen __read_mostly = 5;
  57
  58 void dccp_set_state(struct sock *sk, const int state)
  59 {
  60         const int oldstate = sk->sk_state;
  61
  62         dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
  63                       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_CLOSING || oldstate == DCCP_OPEN)
  75                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  76
  77                 sk->sk_prot->unhash(sk);
  78                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
  79                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
  80                         inet_put_port(&dccp_hashinfo, sk);
  81                 /* fall through */
  82         default:
  83                 if (oldstate == DCCP_OPEN)
  84                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
  85         }
  86
  87         /* Change state AFTER socket is unhashed to avoid closed
  88          * socket sitting in hash tables.
  89          */
  90         sk->sk_state = state;
  91 }
  92
  93 EXPORT_SYMBOL_GPL(dccp_set_state);
  94
  95 void dccp_done(struct sock *sk)
  96 {
  97         dccp_set_state(sk, DCCP_CLOSED);
  98         dccp_clear_xmit_timers(sk);
  99
 100         sk->sk_shutdown = SHUTDOWN_MASK;
 101
 102         if (!sock_flag(sk, SOCK_DEAD))
 103                 sk->sk_state_change(sk);
 104         else
 105                 inet_csk_destroy_sock(sk);
 106 }
 107
 108 EXPORT_SYMBOL_GPL(dccp_done);
 109
 110 const char *dccp_packet_name(const int type)
 111 {
 112         static const char *dccp_packet_names[] = {
 113                 [DCCP_PKT_REQUEST]  = "REQUEST",
 114                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 115                 [DCCP_PKT_DATA]     = "DATA",
 116                 [DCCP_PKT_ACK]      = "ACK",
 117                 [DCCP_PKT_DATAACK]  = "DATAACK",
 118                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 119                 [DCCP_PKT_CLOSE]    = "CLOSE",
 120                 [DCCP_PKT_RESET]    = "RESET",
 121                 [DCCP_PKT_SYNC]     = "SYNC",
 122                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 123         };
 124
 125         if (type >= DCCP_NR_PKT_TYPES)
 126                 return "INVALID";
 127         else
 128                 return dccp_packet_names[type];
 129 }
 130
 131 EXPORT_SYMBOL_GPL(dccp_packet_name);
 132
 133 const char *dccp_state_name(const int state)
 134 {
 135         static char *dccp_state_names[] = {
 136         [DCCP_OPEN]       = "OPEN",
 137         [DCCP_REQUESTING] = "REQUESTING",
 138         [DCCP_PARTOPEN]   = "PARTOPEN",
 139         [DCCP_LISTEN]     = "LISTEN",
 140         [DCCP_RESPOND]    = "RESPOND",
 141         [DCCP_CLOSING]    = "CLOSING",
 142         [DCCP_TIME_WAIT]  = "TIME_WAIT",
 143         [DCCP_CLOSED]     = "CLOSED",
 144         };
 145
 146         if (state >= DCCP_MAX_STATES)
 147                 return "INVALID STATE!";
 148         else
 149                 return dccp_state_names[state];
 150 }
 151
 152 EXPORT_SYMBOL_GPL(dccp_state_name);
 153
 154 void dccp_hash(struct sock *sk)
 155 {
 156         inet_hash(&dccp_hashinfo, sk);
 157 }
 158
 159 EXPORT_SYMBOL_GPL(dccp_hash);
 160
 161 void dccp_unhash(struct sock *sk)
 162 {
 163         inet_unhash(&dccp_hashinfo, sk);
 164 }
 165
 166 EXPORT_SYMBOL_GPL(dccp_unhash);
 167
 168 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 169 {
 170         struct dccp_sock *dp = dccp_sk(sk);
 171         struct dccp_minisock *dmsk = dccp_msk(sk);
 172         struct inet_connection_sock *icsk = inet_csk(sk);
 173
 174         dccp_minisock_init(&dp->dccps_minisock);
 175
 176         /*
 177          * FIXME: We're hardcoding the CCID, and doing this at this point makes
 178          * the listening (master) sock get CCID control blocks, which is not
 179          * necessary, but for now, to not mess with the test userspace apps,
 180          * lets leave it here, later the real solution is to do this in a
 181          * setsockopt(CCIDs-I-want/accept). -acme
 182          */
 183         if (likely(ctl_sock_initialized)) {
 184                 int rc = dccp_feat_init(dmsk);
 185
 186                 if (rc)
 187                         return rc;
 188
 189                 if (dmsk->dccpms_send_ack_vector) {
 190                         dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
 191                         if (dp->dccps_hc_rx_ackvec == NULL)
 192                                 return -ENOMEM;
 193                 }
 194                 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
 195                                                       sk, GFP_KERNEL);
 196                 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
 197                                                       sk, GFP_KERNEL);
 198                 if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
 199                              dp->dccps_hc_tx_ccid == NULL)) {
 200                         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 201                         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 202                         if (dmsk->dccpms_send_ack_vector) {
 203                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 204                                 dp->dccps_hc_rx_ackvec = NULL;
 205                         }
 206                         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 207                         return -ENOMEM;
 208                 }
 209         } else {
 210                 /* control socket doesn't need feat nego */
 211                 INIT_LIST_HEAD(&dmsk->dccpms_pending);
 212                 INIT_LIST_HEAD(&dmsk->dccpms_conf);
 213         }
 214
 215         dccp_init_xmit_timers(sk);
 216         icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 217         icsk->icsk_syn_retries  = sysctl_dccp_request_retries;
 218         sk->sk_state            = DCCP_CLOSED;
 219         sk->sk_write_space      = dccp_write_space;
 220         icsk->icsk_sync_mss     = dccp_sync_mss;
 221         dp->dccps_mss_cache     = 536;
 222         dp->dccps_rate_last     = jiffies;
 223         dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 224         dp->dccps_service       = DCCP_SERVICE_CODE_IS_ABSENT;
 225         dp->dccps_l_ack_ratio   = dp->dccps_r_ack_ratio = 1;
 226
 227         return 0;
 228 }
 229
 230 EXPORT_SYMBOL_GPL(dccp_init_sock);
 231
 232 int dccp_destroy_sock(struct sock *sk)
 233 {
 234         struct dccp_sock *dp = dccp_sk(sk);
 235         struct dccp_minisock *dmsk = dccp_msk(sk);
 236
 237         /*
 238          * DCCP doesn't use sk_write_queue, just sk_send_head
 239          * for retransmissions
 240          */
 241         if (sk->sk_send_head != NULL) {
 242                 kfree_skb(sk->sk_send_head);
 243                 sk->sk_send_head = NULL;
 244         }
 245
 246         /* Clean up a referenced DCCP bind bucket. */
 247         if (inet_csk(sk)->icsk_bind_hash != NULL)
 248                 inet_put_port(&dccp_hashinfo, sk);
 249
 250         kfree(dp->dccps_service_list);
 251         dp->dccps_service_list = NULL;
 252
 253         if (dmsk->dccpms_send_ack_vector) {
 254                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 255                 dp->dccps_hc_rx_ackvec = NULL;
 256         }
 257         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 258         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 259         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 260
 261         /* clean up feature negotiation state */
 262         dccp_feat_clean(dmsk);
 263
 264         return 0;
 265 }
 266
 267 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 268
 269 static inline int dccp_listen_start(struct sock *sk, int backlog)
 270 {
 271         struct dccp_sock *dp = dccp_sk(sk);
 272
 273         dp->dccps_role = DCCP_ROLE_LISTEN;
 274         return inet_csk_listen_start(sk, backlog);
 275 }
 276
 277 int dccp_disconnect(struct sock *sk, int flags)
 278 {
 279         struct inet_connection_sock *icsk = inet_csk(sk);
 280         struct inet_sock *inet = inet_sk(sk);
 281         int err = 0;
 282         const int old_state = sk->sk_state;
 283
 284         if (old_state != DCCP_CLOSED)
 285                 dccp_set_state(sk, DCCP_CLOSED);
 286
 287         /* ABORT function of RFC793 */
 288         if (old_state == DCCP_LISTEN) {
 289                 inet_csk_listen_stop(sk);
 290         /* FIXME: do the active reset thing */
 291         } else if (old_state == DCCP_REQUESTING)
 292                 sk->sk_err = ECONNRESET;
 293
 294         dccp_clear_xmit_timers(sk);
 295         __skb_queue_purge(&sk->sk_receive_queue);
 296         if (sk->sk_send_head != NULL) {
 297                 __kfree_skb(sk->sk_send_head);
 298                 sk->sk_send_head = NULL;
 299         }
 300
 301         inet->dport = 0;
 302
 303         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 304                 inet_reset_saddr(sk);
 305
 306         sk->sk_shutdown = 0;
 307         sock_reset_flag(sk, SOCK_DONE);
 308
 309         icsk->icsk_backoff = 0;
 310         inet_csk_delack_init(sk);
 311         __sk_dst_reset(sk);
 312
 313         BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
 314
 315         sk->sk_error_report(sk);
 316         return err;
 317 }
 318
 319 EXPORT_SYMBOL_GPL(dccp_disconnect);
 320
 321 /*
 322  *      Wait for a DCCP event.
 323  *
 324  *      Note that we don't need to lock the socket, as the upper poll layers
 325  *      take care of normal races (between the test and the event) and we don't
 326  *      go look at any of the socket buffers directly.
 327  */
 328 unsigned int dccp_poll(struct file *file, struct socket *sock,
 329                        poll_table *wait)
 330 {
 331         unsigned int mask;
 332         struct sock *sk = sock->sk;
 333
 334         poll_wait(file, sk->sk_sleep, wait);
 335         if (sk->sk_state == DCCP_LISTEN)
 336                 return inet_csk_listen_poll(sk);
 337
 338         /* Socket is not locked. We are protected from async events
 339            by poll logic and correct handling of state changes
 340            made by another threads is impossible in any case.
 341          */
 342
 343         mask = 0;
 344         if (sk->sk_err)
 345                 mask = POLLERR;
 346
 347         if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
 348                 mask |= POLLHUP;
 349         if (sk->sk_shutdown & RCV_SHUTDOWN)
 350                 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 351
 352         /* Connected? */
 353         if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 354                 if (atomic_read(&sk->sk_rmem_alloc) > 0)
 355                         mask |= POLLIN | POLLRDNORM;
 356
 357                 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 358                         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 359                                 mask |= POLLOUT | POLLWRNORM;
 360                         } else {  /* send SIGIO later */
 361                                 set_bit(SOCK_ASYNC_NOSPACE,
 362                                         &sk->sk_socket->flags);
 363                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 364
 365                                 /* Race breaker. If space is freed after
 366                                  * wspace test but before the flags are set,
 367                                  * IO signal will be lost.
 368                                  */
 369                                 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
 370                                         mask |= POLLOUT | POLLWRNORM;
 371                         }
 372                 }
 373         }
 374         return mask;
 375 }
 376
 377 EXPORT_SYMBOL_GPL(dccp_poll);
 378
 379 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 380 {
 381         dccp_pr_debug("entry\n");
 382         return -ENOIOCTLCMD;
 383 }
 384
 385 EXPORT_SYMBOL_GPL(dccp_ioctl);
 386
 387 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 388                                    char __user *optval, int optlen)
 389 {
 390         struct dccp_sock *dp = dccp_sk(sk);
 391         struct dccp_service_list *sl = NULL;
 392
 393         if (service == DCCP_SERVICE_INVALID_VALUE ||
 394             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 395                 return -EINVAL;
 396
 397         if (optlen > sizeof(service)) {
 398                 sl = kmalloc(optlen, GFP_KERNEL);
 399                 if (sl == NULL)
 400                         return -ENOMEM;
 401
 402                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 403                 if (copy_from_user(sl->dccpsl_list,
 404                                    optval + sizeof(service),
 405                                    optlen - sizeof(service)) ||
 406                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 407                         kfree(sl);
 408                         return -EFAULT;
 409                 }
 410         }
 411
 412         lock_sock(sk);
 413         dp->dccps_service = service;
 414
 415         kfree(dp->dccps_service_list);
 416
 417         dp->dccps_service_list = sl;
 418         release_sock(sk);
 419         return 0;
 420 }
 421
 422 /* byte 1 is feature.  the rest is the preference list */
 423 static int dccp_setsockopt_change(struct sock *sk, int type,
 424                                   struct dccp_so_feat __user *optval)
 425 {
 426         struct dccp_so_feat opt;
 427         u8 *val;
 428         int rc;
 429
 430         if (copy_from_user(&opt, optval, sizeof(opt)))
 431                 return -EFAULT;
 432
 433         val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
 434         if (!val)
 435                 return -ENOMEM;
 436
 437         if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
 438                 rc = -EFAULT;
 439                 goto out_free_val;
 440         }
 441
 442         rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
 443                               val, opt.dccpsf_len, GFP_KERNEL);
 444         if (rc)
 445                 goto out_free_val;
 446
 447 out:
 448         return rc;
 449
 450 out_free_val:
 451         kfree(val);
 452         goto out;
 453 }
 454
 455 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 456                 char __user *optval, int optlen)
 457 {
 458         struct dccp_sock *dp = dccp_sk(sk);
 459         int val, err = 0;
 460
 461         if (optlen < sizeof(int))
 462                 return -EINVAL;
 463
 464         if (get_user(val, (int __user *)optval))
 465                 return -EFAULT;
 466
 467         if (optname == DCCP_SOCKOPT_SERVICE)
 468                 return dccp_setsockopt_service(sk, val, optval, optlen);
 469
 470         lock_sock(sk);
 471         switch (optname) {
 472         case DCCP_SOCKOPT_PACKET_SIZE:
 473                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 474                 err = 0;
 475                 break;
 476         case DCCP_SOCKOPT_CHANGE_L:
 477                 if (optlen != sizeof(struct dccp_so_feat))
 478                         err = -EINVAL;
 479                 else
 480                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
 481                                                      (struct dccp_so_feat __user *)
 482                                                      optval);
 483                 break;
 484         case DCCP_SOCKOPT_CHANGE_R:
 485                 if (optlen != sizeof(struct dccp_so_feat))
 486                         err = -EINVAL;
 487                 else
 488                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
 489                                                      (struct dccp_so_feat __user *)
 490                                                      optval);
 491                 break;
 492         case DCCP_SOCKOPT_SEND_CSCOV:   /* sender side, RFC 4340, sec. 9.2 */
 493                 if (val < 0 || val > 15)
 494                         err = -EINVAL;
 495                 else
 496                         dp->dccps_pcslen = val;
 497                 break;
 498         case DCCP_SOCKOPT_RECV_CSCOV:   /* receiver side, RFC 4340 sec. 9.2.1 */
 499                 if (val < 0 || val > 15)
 500                         err = -EINVAL;
 501                 else {
 502                         dp->dccps_pcrlen = val;
 503                         /* FIXME: add feature negotiation,
 504                          * ChangeL(MinimumChecksumCoverage, val) */
 505                 }
 506                 break;
 507         default:
 508                 err = -ENOPROTOOPT;
 509                 break;
 510         }
 511
 512         release_sock(sk);
 513         return err;
 514 }
 515
 516 int dccp_setsockopt(struct sock *sk, int level, int optname,
 517                     char __user *optval, int optlen)
 518 {
 519         if (level != SOL_DCCP)
 520                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 521                                                              optname, optval,
 522                                                              optlen);
 523         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 524 }
 525
 526 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 527
 528 #ifdef CONFIG_COMPAT
 529 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 530                            char __user *optval, int optlen)
 531 {
 532         if (level != SOL_DCCP)
 533                 return inet_csk_compat_setsockopt(sk, level, optname,
 534                                                   optval, optlen);
 535         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 536 }
 537
 538 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 539 #endif
 540
 541 static int dccp_getsockopt_service(struct sock *sk, int len,
 542                                    __be32 __user *optval,
 543                                    int __user *optlen)
 544 {
 545         const struct dccp_sock *dp = dccp_sk(sk);
 546         const struct dccp_service_list *sl;
 547         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 548
 549         lock_sock(sk);
 550         if ((sl = dp->dccps_service_list) != NULL) {
 551                 slen = sl->dccpsl_nr * sizeof(u32);
 552                 total_len += slen;
 553         }
 554
 555         err = -EINVAL;
 556         if (total_len > len)
 557                 goto out;
 558
 559         err = 0;
 560         if (put_user(total_len, optlen) ||
 561             put_user(dp->dccps_service, optval) ||
 562             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 563                 err = -EFAULT;
 564 out:
 565         release_sock(sk);
 566         return err;
 567 }
 568
 569 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 570                     char __user *optval, int __user *optlen)
 571 {
 572         struct dccp_sock *dp;
 573         int val, len;
 574
 575         if (get_user(len, optlen))
 576                 return -EFAULT;
 577
 578         if (len < (int)sizeof(int))
 579                 return -EINVAL;
 580
 581         dp = dccp_sk(sk);
 582
 583         switch (optname) {
 584         case DCCP_SOCKOPT_PACKET_SIZE:
 585                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 586                 return 0;
 587         case DCCP_SOCKOPT_SERVICE:
 588                 return dccp_getsockopt_service(sk, len,
 589                                                (__be32 __user *)optval, optlen);
 590         case DCCP_SOCKOPT_GET_CUR_MPS:
 591                 val = dp->dccps_mss_cache;
 592                 len = sizeof(val);
 593                 break;
 594         case DCCP_SOCKOPT_SEND_CSCOV:
 595                 val = dp->dccps_pcslen;
 596                 len = sizeof(val);
 597                 break;
 598         case DCCP_SOCKOPT_RECV_CSCOV:
 599                 val = dp->dccps_pcrlen;
 600                 len = sizeof(val);
 601                 break;
 602         case 128 ... 191:
 603                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 604                                              len, (u32 __user *)optval, optlen);
 605         case 192 ... 255:
 606                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 607                                              len, (u32 __user *)optval, optlen);
 608         default:
 609                 return -ENOPROTOOPT;
 610         }
 611
 612         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 613                 return -EFAULT;
 614
 615         return 0;
 616 }
 617
 618 int dccp_getsockopt(struct sock *sk, int level, int optname,
 619                     char __user *optval, int __user *optlen)
 620 {
 621         if (level != SOL_DCCP)
 622                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 623                                                              optname, optval,
 624                                                              optlen);
 625         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 626 }
 627
 628 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 629
 630 #ifdef CONFIG_COMPAT
 631 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 632                            char __user *optval, int __user *optlen)
 633 {
 634         if (level != SOL_DCCP)
 635                 return inet_csk_compat_getsockopt(sk, level, optname,
 636                                                   optval, optlen);
 637         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 638 }
 639
 640 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 641 #endif
 642
 643 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 644                  size_t len)
 645 {
 646         const struct dccp_sock *dp = dccp_sk(sk);
 647         const int flags = msg->msg_flags;
 648         const int noblock = flags & MSG_DONTWAIT;
 649         struct sk_buff *skb;
 650         int rc, size;
 651         long timeo;
 652
 653         if (len > dp->dccps_mss_cache)
 654                 return -EMSGSIZE;
 655
 656         lock_sock(sk);
 657
 658         if (sysctl_dccp_tx_qlen &&
 659             (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
 660                 rc = -EAGAIN;
 661                 goto out_release;
 662         }
 663
 664         timeo = sock_sndtimeo(sk, noblock);
 665
 666         /*
 667          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 668          * so that the trick in dccp_rcv_request_sent_state_process.
 669          */
 670         /* Wait for a connection to finish. */
 671         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 672                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 673                         goto out_release;
 674
 675         size = sk->sk_prot->max_header + len;
 676         release_sock(sk);
 677         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 678         lock_sock(sk);
 679         if (skb == NULL)
 680                 goto out_release;
 681
 682         skb_reserve(skb, sk->sk_prot->max_header);
 683         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 684         if (rc != 0)
 685                 goto out_discard;
 686
 687         skb_queue_tail(&sk->sk_write_queue, skb);
 688         dccp_write_xmit(sk,0);
 689 out_release:
 690         release_sock(sk);
 691         return rc ? : len;
 692 out_discard:
 693         kfree_skb(skb);
 694         goto out_release;
 695 }
 696
 697 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 698
 699 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 700                  size_t len, int nonblock, int flags, int *addr_len)
 701 {
 702         const struct dccp_hdr *dh;
 703         long timeo;
 704
 705         lock_sock(sk);
 706
 707         if (sk->sk_state == DCCP_LISTEN) {
 708                 len = -ENOTCONN;
 709                 goto out;
 710         }
 711
 712         timeo = sock_rcvtimeo(sk, nonblock);
 713
 714         do {
 715                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 716
 717                 if (skb == NULL)
 718                         goto verify_sock_status;
 719
 720                 dh = dccp_hdr(skb);
 721
 722                 if (dh->dccph_type == DCCP_PKT_DATA ||
 723                     dh->dccph_type == DCCP_PKT_DATAACK)
 724                         goto found_ok_skb;
 725
 726                 if (dh->dccph_type == DCCP_PKT_RESET ||
 727                     dh->dccph_type == DCCP_PKT_CLOSE) {
 728                         dccp_pr_debug("found fin ok!\n");
 729                         len = 0;
 730                         goto found_fin_ok;
 731                 }
 732                 dccp_pr_debug("packet_type=%s\n",
 733                               dccp_packet_name(dh->dccph_type));
 734                 sk_eat_skb(sk, skb, 0);
 735 verify_sock_status:
 736                 if (sock_flag(sk, SOCK_DONE)) {
 737                         len = 0;
 738                         break;
 739                 }
 740
 741                 if (sk->sk_err) {
 742                         len = sock_error(sk);
 743                         break;
 744                 }
 745
 746                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 747                         len = 0;
 748                         break;
 749                 }
 750
 751                 if (sk->sk_state == DCCP_CLOSED) {
 752                         if (!sock_flag(sk, SOCK_DONE)) {
 753                                 /* This occurs when user tries to read
 754                                  * from never connected socket.
 755                                  */
 756                                 len = -ENOTCONN;
 757                                 break;
 758                         }
 759                         len = 0;
 760                         break;
 761                 }
 762
 763                 if (!timeo) {
 764                         len = -EAGAIN;
 765                         break;
 766                 }
 767
 768                 if (signal_pending(current)) {
 769                         len = sock_intr_errno(timeo);
 770                         break;
 771                 }
 772
 773                 sk_wait_data(sk, &timeo);
 774                 continue;
 775         found_ok_skb:
 776                 if (len > skb->len)
 777                         len = skb->len;
 778                 else if (len < skb->len)
 779                         msg->msg_flags |= MSG_TRUNC;
 780
 781                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 782                         /* Exception. Bailout! */
 783                         len = -EFAULT;
 784                         break;
 785                 }
 786         found_fin_ok:
 787                 if (!(flags & MSG_PEEK))
 788                         sk_eat_skb(sk, skb, 0);
 789                 break;
 790         } while (1);
 791 out:
 792         release_sock(sk);
 793         return len;
 794 }
 795
 796 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 797
 798 int inet_dccp_listen(struct socket *sock, int backlog)
 799 {
 800         struct sock *sk = sock->sk;
 801         unsigned char old_state;
 802         int err;
 803
 804         lock_sock(sk);
 805
 806         err = -EINVAL;
 807         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 808                 goto out;
 809
 810         old_state = sk->sk_state;
 811         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 812                 goto out;
 813
 814         /* Really, if the socket is already in listen state
 815          * we can only allow the backlog to be adjusted.
 816          */
 817         if (old_state != DCCP_LISTEN) {
 818                 /*
 819                  * FIXME: here it probably should be sk->sk_prot->listen_start
 820                  * see tcp_listen_start
 821                  */
 822                 err = dccp_listen_start(sk, backlog);
 823                 if (err)
 824                         goto out;
 825         }
 826         sk->sk_max_ack_backlog = backlog;
 827         err = 0;
 828
 829 out:
 830         release_sock(sk);
 831         return err;
 832 }
 833
 834 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 835
 836 static const unsigned char dccp_new_state[] = {
 837         /* current state:   new state:      action:     */
 838         [0]               = DCCP_CLOSED,
 839         [DCCP_OPEN]       = DCCP_CLOSING | DCCP_ACTION_FIN,
 840         [DCCP_REQUESTING] = DCCP_CLOSED,
 841         [DCCP_PARTOPEN]   = DCCP_CLOSING | DCCP_ACTION_FIN,
 842         [DCCP_LISTEN]     = DCCP_CLOSED,
 843         [DCCP_RESPOND]    = DCCP_CLOSED,
 844         [DCCP_CLOSING]    = DCCP_CLOSED,
 845         [DCCP_TIME_WAIT]  = DCCP_CLOSED,
 846         [DCCP_CLOSED]     = DCCP_CLOSED,
 847 };
 848
 849 static int dccp_close_state(struct sock *sk)
 850 {
 851         const int next = dccp_new_state[sk->sk_state];
 852         const int ns = next & DCCP_STATE_MASK;
 853
 854         if (ns != sk->sk_state)
 855                 dccp_set_state(sk, ns);
 856
 857         return next & DCCP_ACTION_FIN;
 858 }
 859
 860 void dccp_close(struct sock *sk, long timeout)
 861 {
 862         struct dccp_sock *dp = dccp_sk(sk);
 863         struct sk_buff *skb;
 864         int state;
 865
 866         lock_sock(sk);
 867
 868         sk->sk_shutdown = SHUTDOWN_MASK;
 869
 870         if (sk->sk_state == DCCP_LISTEN) {
 871                 dccp_set_state(sk, DCCP_CLOSED);
 872
 873                 /* Special case. */
 874                 inet_csk_listen_stop(sk);
 875
 876                 goto adjudge_to_death;
 877         }
 878
 879         sk_stop_timer(sk, &dp->dccps_xmit_timer);
 880
 881         /*
 882          * We need to flush the recv. buffs.  We do this only on the
 883          * descriptor close, not protocol-sourced closes, because the
 884           *reader process may not have drained the data yet!
 885          */
 886         /* FIXME: check for unread data */
 887         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 888                 __kfree_skb(skb);
 889         }
 890
 891         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 892                 /* Check zero linger _after_ checking for unread data. */
 893                 sk->sk_prot->disconnect(sk, 0);
 894         } else if (dccp_close_state(sk)) {
 895                 dccp_send_close(sk, 1);
 896         }
 897
 898         sk_stream_wait_close(sk, timeout);
 899
 900 adjudge_to_death:
 901         state = sk->sk_state;
 902         sock_hold(sk);
 903         sock_orphan(sk);
 904         atomic_inc(sk->sk_prot->orphan_count);
 905
 906         /*
 907          * It is the last release_sock in its life. It will remove backlog.
 908          */
 909         release_sock(sk);
 910         /*
 911          * Now socket is owned by kernel and we acquire BH lock
 912          * to finish close. No need to check for user refs.
 913          */
 914         local_bh_disable();
 915         bh_lock_sock(sk);
 916         BUG_TRAP(!sock_owned_by_user(sk));
 917
 918         /* Have we already been destroyed by a softirq or backlog? */
 919         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
 920                 goto out;
 921
 922         /*
 923          * The last release_sock may have processed the CLOSE or RESET
 924          * packet moving sock to CLOSED state, if not we have to fire
 925          * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
 926          * in draft-ietf-dccp-spec-11. -acme
 927          */
 928         if (sk->sk_state == DCCP_CLOSING) {
 929                 /* FIXME: should start at 2 * RTT */
 930                 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
 931                 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 932                                           inet_csk(sk)->icsk_rto,
 933                                           DCCP_RTO_MAX);
 934 #if 0
 935                 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
 936                 dccp_set_state(sk, DCCP_CLOSED);
 937 #endif
 938         }
 939
 940         if (sk->sk_state == DCCP_CLOSED)
 941                 inet_csk_destroy_sock(sk);
 942
 943         /* Otherwise, socket is reprieved until protocol close. */
 944
 945 out:
 946         bh_unlock_sock(sk);
 947         local_bh_enable();
 948         sock_put(sk);
 949 }
 950
 951 EXPORT_SYMBOL_GPL(dccp_close);
 952
 953 void dccp_shutdown(struct sock *sk, int how)
 954 {
 955         dccp_pr_debug("entry\n");
 956 }
 957
 958 EXPORT_SYMBOL_GPL(dccp_shutdown);
 959
 960 static int __init dccp_mib_init(void)
 961 {
 962         int rc = -ENOMEM;
 963
 964         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 965         if (dccp_statistics[0] == NULL)
 966                 goto out;
 967
 968         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 969         if (dccp_statistics[1] == NULL)
 970                 goto out_free_one;
 971
 972         rc = 0;
 973 out:
 974         return rc;
 975 out_free_one:
 976         free_percpu(dccp_statistics[0]);
 977         dccp_statistics[0] = NULL;
 978         goto out;
 979
 980 }
 981
 982 static void dccp_mib_exit(void)
 983 {
 984         free_percpu(dccp_statistics[0]);
 985         free_percpu(dccp_statistics[1]);
 986         dccp_statistics[0] = dccp_statistics[1] = NULL;
 987 }
 988
 989 static int thash_entries;
 990 module_param(thash_entries, int, 0444);
 991 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 992
 993 #ifdef CONFIG_IP_DCCP_DEBUG
 994 int dccp_debug;
 995 module_param(dccp_debug, bool, 0444);
 996 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 997
 998 EXPORT_SYMBOL_GPL(dccp_debug);
 999 #endif
1000
1001 static int __init dccp_init(void)
1002 {
1003         unsigned long goal;
1004         int ehash_order, bhash_order, i;
1005         int rc = -ENOBUFS;
1006
1007         dccp_hashinfo.bind_bucket_cachep =
1008                 kmem_cache_create("dccp_bind_bucket",
1009                                   sizeof(struct inet_bind_bucket), 0,
1010                                   SLAB_HWCACHE_ALIGN, NULL);
1011         if (!dccp_hashinfo.bind_bucket_cachep)
1012                 goto out;
1013
1014         /*
1015          * Size and allocate the main established and bind bucket
1016          * hash tables.
1017          *
1018          * The methodology is similar to that of the buffer cache.
1019          */
1020         if (num_physpages >= (128 * 1024))
1021                 goal = num_physpages >> (21 - PAGE_SHIFT);
1022         else
1023                 goal = num_physpages >> (23 - PAGE_SHIFT);
1024
1025         if (thash_entries)
1026                 goal = (thash_entries *
1027                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1028         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1029                 ;
1030         do {
1031                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1032                                         sizeof(struct inet_ehash_bucket);
1033                 while (dccp_hashinfo.ehash_size &
1034                        (dccp_hashinfo.ehash_size - 1))
1035                         dccp_hashinfo.ehash_size--;
1036                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1037                         __get_free_pages(GFP_ATOMIC, ehash_order);
1038         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1039
1040         if (!dccp_hashinfo.ehash) {
1041                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1042                 goto out_free_bind_bucket_cachep;
1043         }
1044
1045         for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
1046                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
1047                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
1048                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].twchain);
1049         }
1050
1051         bhash_order = ehash_order;
1052
1053         do {
1054                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1055                                         sizeof(struct inet_bind_hashbucket);
1056                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1057                     bhash_order > 0)
1058                         continue;
1059                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1060                         __get_free_pages(GFP_ATOMIC, bhash_order);
1061         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1062
1063         if (!dccp_hashinfo.bhash) {
1064                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1065                 goto out_free_dccp_ehash;
1066         }
1067
1068         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1069                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1070                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1071         }
1072
1073         rc = dccp_mib_init();
1074         if (rc)
1075                 goto out_free_dccp_bhash;
1076
1077         rc = dccp_ackvec_init();
1078         if (rc)
1079                 goto out_free_dccp_mib;
1080
1081         rc = dccp_sysctl_init();
1082         if (rc)
1083                 goto out_ackvec_exit;
1084
1085         dccp_timestamping_init();
1086 out:
1087         return rc;
1088 out_ackvec_exit:
1089         dccp_ackvec_exit();
1090 out_free_dccp_mib:
1091         dccp_mib_exit();
1092 out_free_dccp_bhash:
1093         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1094         dccp_hashinfo.bhash = NULL;
1095 out_free_dccp_ehash:
1096         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1097         dccp_hashinfo.ehash = NULL;
1098 out_free_bind_bucket_cachep:
1099         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1100         dccp_hashinfo.bind_bucket_cachep = NULL;
1101         goto out;
1102 }
1103
1104 static void __exit dccp_fini(void)
1105 {
1106         dccp_mib_exit();
1107         free_pages((unsigned long)dccp_hashinfo.bhash,
1108                    get_order(dccp_hashinfo.bhash_size *
1109                              sizeof(struct inet_bind_hashbucket)));
1110         free_pages((unsigned long)dccp_hashinfo.ehash,
1111                    get_order(dccp_hashinfo.ehash_size *
1112                              sizeof(struct inet_ehash_bucket)));
1113         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1114         dccp_ackvec_exit();
1115         dccp_sysctl_exit();
1116 }
1117
1118 module_init(dccp_init);
1119 module_exit(dccp_fini);
1120
1121 MODULE_LICENSE("GPL");
1122 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1123 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");