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   1 /*
   2  *  net/dccp/proto.c
   3  *
   4  *  An implementation of the DCCP protocol
   5  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify it
   8  *      under the terms of the GNU General Public License version 2 as
   9  *      published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/dccp.h>
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/in.h>
  21 #include <linux/if_arp.h>
  22 #include <linux/init.h>
  23 #include <linux/random.h>
  24 #include <net/checksum.h>
  25
  26 #include <net/inet_sock.h>
  27 #include <net/sock.h>
  28 #include <net/xfrm.h>
  29
  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 void dccp_set_state(struct sock *sk, const int state)
  57 {
  58         const int oldstate = sk->sk_state;
  59
  60         dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
  61                       dccp_role(sk), sk,
  62                       dccp_state_name(oldstate), dccp_state_name(state));
  63         WARN_ON(state == oldstate);
  64
  65         switch (state) {
  66         case DCCP_OPEN:
  67                 if (oldstate != DCCP_OPEN)
  68                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  69                 break;
  70
  71         case DCCP_CLOSED:
  72                 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
  73                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  74
  75                 sk->sk_prot->unhash(sk);
  76                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
  77                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
  78                         inet_put_port(&dccp_hashinfo, sk);
  79                 /* fall through */
  80         default:
  81                 if (oldstate == DCCP_OPEN)
  82                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
  83         }
  84
  85         /* Change state AFTER socket is unhashed to avoid closed
  86          * socket sitting in hash tables.
  87          */
  88         sk->sk_state = state;
  89 }
  90
  91 EXPORT_SYMBOL_GPL(dccp_set_state);
  92
  93 void dccp_done(struct sock *sk)
  94 {
  95         dccp_set_state(sk, DCCP_CLOSED);
  96         dccp_clear_xmit_timers(sk);
  97
  98         sk->sk_shutdown = SHUTDOWN_MASK;
  99
 100         if (!sock_flag(sk, SOCK_DEAD))
 101                 sk->sk_state_change(sk);
 102         else
 103                 inet_csk_destroy_sock(sk);
 104 }
 105
 106 EXPORT_SYMBOL_GPL(dccp_done);
 107
 108 const char *dccp_packet_name(const int type)
 109 {
 110         static const char *dccp_packet_names[] = {
 111                 [DCCP_PKT_REQUEST]  = "REQUEST",
 112                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 113                 [DCCP_PKT_DATA]     = "DATA",
 114                 [DCCP_PKT_ACK]      = "ACK",
 115                 [DCCP_PKT_DATAACK]  = "DATAACK",
 116                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 117                 [DCCP_PKT_CLOSE]    = "CLOSE",
 118                 [DCCP_PKT_RESET]    = "RESET",
 119                 [DCCP_PKT_SYNC]     = "SYNC",
 120                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 121         };
 122
 123         if (type >= DCCP_NR_PKT_TYPES)
 124                 return "INVALID";
 125         else
 126                 return dccp_packet_names[type];
 127 }
 128
 129 EXPORT_SYMBOL_GPL(dccp_packet_name);
 130
 131 const char *dccp_state_name(const int state)
 132 {
 133         static char *dccp_state_names[] = {
 134         [DCCP_OPEN]       = "OPEN",
 135         [DCCP_REQUESTING] = "REQUESTING",
 136         [DCCP_PARTOPEN]   = "PARTOPEN",
 137         [DCCP_LISTEN]     = "LISTEN",
 138         [DCCP_RESPOND]    = "RESPOND",
 139         [DCCP_CLOSING]    = "CLOSING",
 140         [DCCP_TIME_WAIT]  = "TIME_WAIT",
 141         [DCCP_CLOSED]     = "CLOSED",
 142         };
 143
 144         if (state >= DCCP_MAX_STATES)
 145                 return "INVALID STATE!";
 146         else
 147                 return dccp_state_names[state];
 148 }
 149
 150 EXPORT_SYMBOL_GPL(dccp_state_name);
 151
 152 void dccp_hash(struct sock *sk)
 153 {
 154         inet_hash(&dccp_hashinfo, sk);
 155 }
 156
 157 EXPORT_SYMBOL_GPL(dccp_hash);
 158
 159 void dccp_unhash(struct sock *sk)
 160 {
 161         inet_unhash(&dccp_hashinfo, sk);
 162 }
 163
 164 EXPORT_SYMBOL_GPL(dccp_unhash);
 165
 166 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 167 {
 168         struct dccp_sock *dp = dccp_sk(sk);
 169         struct dccp_minisock *dmsk = dccp_msk(sk);
 170         struct inet_connection_sock *icsk = inet_csk(sk);
 171
 172         dccp_minisock_init(&dp->dccps_minisock);
 173         do_gettimeofday(&dp->dccps_epoch);
 174
 175         /*
 176          * FIXME: We're hardcoding the CCID, and doing this at this point makes
 177          * the listening (master) sock get CCID control blocks, which is not
 178          * necessary, but for now, to not mess with the test userspace apps,
 179          * lets leave it here, later the real solution is to do this in a
 180          * setsockopt(CCIDs-I-want/accept). -acme
 181          */
 182         if (likely(ctl_sock_initialized)) {
 183                 int rc = dccp_feat_init(dmsk);
 184
 185                 if (rc)
 186                         return rc;
 187
 188                 if (dmsk->dccpms_send_ack_vector) {
 189                         dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
 190                         if (dp->dccps_hc_rx_ackvec == NULL)
 191                                 return -ENOMEM;
 192                 }
 193                 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
 194                                                       sk, GFP_KERNEL);
 195                 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
 196                                                       sk, GFP_KERNEL);
 197                 if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
 198                              dp->dccps_hc_tx_ccid == NULL)) {
 199                         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 200                         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 201                         if (dmsk->dccpms_send_ack_vector) {
 202                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 203                                 dp->dccps_hc_rx_ackvec = NULL;
 204                         }
 205                         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 206                         return -ENOMEM;
 207                 }
 208         } else {
 209                 /* control socket doesn't need feat nego */
 210                 INIT_LIST_HEAD(&dmsk->dccpms_pending);
 211                 INIT_LIST_HEAD(&dmsk->dccpms_conf);
 212         }
 213
 214         dccp_init_xmit_timers(sk);
 215         icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 216         sk->sk_state            = DCCP_CLOSED;
 217         sk->sk_write_space      = dccp_write_space;
 218         icsk->icsk_sync_mss     = dccp_sync_mss;
 219         dp->dccps_mss_cache     = 536;
 220         dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 221         dp->dccps_service       = DCCP_SERVICE_INVALID_VALUE;
 222         dp->dccps_l_ack_ratio   = dp->dccps_r_ack_ratio = 1;
 223
 224         return 0;
 225 }
 226
 227 EXPORT_SYMBOL_GPL(dccp_init_sock);
 228
 229 int dccp_destroy_sock(struct sock *sk)
 230 {
 231         struct dccp_sock *dp = dccp_sk(sk);
 232         struct dccp_minisock *dmsk = dccp_msk(sk);
 233
 234         /*
 235          * DCCP doesn't use sk_write_queue, just sk_send_head
 236          * for retransmissions
 237          */
 238         if (sk->sk_send_head != NULL) {
 239                 kfree_skb(sk->sk_send_head);
 240                 sk->sk_send_head = NULL;
 241         }
 242
 243         /* Clean up a referenced DCCP bind bucket. */
 244         if (inet_csk(sk)->icsk_bind_hash != NULL)
 245                 inet_put_port(&dccp_hashinfo, sk);
 246
 247         kfree(dp->dccps_service_list);
 248         dp->dccps_service_list = NULL;
 249
 250         if (dmsk->dccpms_send_ack_vector) {
 251                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 252                 dp->dccps_hc_rx_ackvec = NULL;
 253         }
 254         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 255         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 256         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 257
 258         /* clean up feature negotiation state */
 259         dccp_feat_clean(dmsk);
 260
 261         return 0;
 262 }
 263
 264 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 265
 266 static inline int dccp_listen_start(struct sock *sk)
 267 {
 268         struct dccp_sock *dp = dccp_sk(sk);
 269
 270         dp->dccps_role = DCCP_ROLE_LISTEN;
 271         /*
 272          * Apps need to use setsockopt(DCCP_SOCKOPT_SERVICE)
 273          * before calling listen()
 274          */
 275         if (dccp_service_not_initialized(sk))
 276                 return -EPROTO;
 277         return inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
 278 }
 279
 280 int dccp_disconnect(struct sock *sk, int flags)
 281 {
 282         struct inet_connection_sock *icsk = inet_csk(sk);
 283         struct inet_sock *inet = inet_sk(sk);
 284         int err = 0;
 285         const int old_state = sk->sk_state;
 286
 287         if (old_state != DCCP_CLOSED)
 288                 dccp_set_state(sk, DCCP_CLOSED);
 289
 290         /* ABORT function of RFC793 */
 291         if (old_state == DCCP_LISTEN) {
 292                 inet_csk_listen_stop(sk);
 293         /* FIXME: do the active reset thing */
 294         } else if (old_state == DCCP_REQUESTING)
 295                 sk->sk_err = ECONNRESET;
 296
 297         dccp_clear_xmit_timers(sk);
 298         __skb_queue_purge(&sk->sk_receive_queue);
 299         if (sk->sk_send_head != NULL) {
 300                 __kfree_skb(sk->sk_send_head);
 301                 sk->sk_send_head = NULL;
 302         }
 303
 304         inet->dport = 0;
 305
 306         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 307                 inet_reset_saddr(sk);
 308
 309         sk->sk_shutdown = 0;
 310         sock_reset_flag(sk, SOCK_DONE);
 311
 312         icsk->icsk_backoff = 0;
 313         inet_csk_delack_init(sk);
 314         __sk_dst_reset(sk);
 315
 316         BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
 317
 318         sk->sk_error_report(sk);
 319         return err;
 320 }
 321
 322 EXPORT_SYMBOL_GPL(dccp_disconnect);
 323
 324 /*
 325  *      Wait for a DCCP event.
 326  *
 327  *      Note that we don't need to lock the socket, as the upper poll layers
 328  *      take care of normal races (between the test and the event) and we don't
 329  *      go look at any of the socket buffers directly.
 330  */
 331 unsigned int dccp_poll(struct file *file, struct socket *sock,
 332                        poll_table *wait)
 333 {
 334         unsigned int mask;
 335         struct sock *sk = sock->sk;
 336
 337         poll_wait(file, sk->sk_sleep, wait);
 338         if (sk->sk_state == DCCP_LISTEN)
 339                 return inet_csk_listen_poll(sk);
 340
 341         /* Socket is not locked. We are protected from async events
 342            by poll logic and correct handling of state changes
 343            made by another threads is impossible in any case.
 344          */
 345
 346         mask = 0;
 347         if (sk->sk_err)
 348                 mask = POLLERR;
 349
 350         if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
 351                 mask |= POLLHUP;
 352         if (sk->sk_shutdown & RCV_SHUTDOWN)
 353                 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 354
 355         /* Connected? */
 356         if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 357                 if (atomic_read(&sk->sk_rmem_alloc) > 0)
 358                         mask |= POLLIN | POLLRDNORM;
 359
 360                 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 361                         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 362                                 mask |= POLLOUT | POLLWRNORM;
 363                         } else {  /* send SIGIO later */
 364                                 set_bit(SOCK_ASYNC_NOSPACE,
 365                                         &sk->sk_socket->flags);
 366                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 367
 368                                 /* Race breaker. If space is freed after
 369                                  * wspace test but before the flags are set,
 370                                  * IO signal will be lost.
 371                                  */
 372                                 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
 373                                         mask |= POLLOUT | POLLWRNORM;
 374                         }
 375                 }
 376         }
 377         return mask;
 378 }
 379
 380 EXPORT_SYMBOL_GPL(dccp_poll);
 381
 382 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 383 {
 384         dccp_pr_debug("entry\n");
 385         return -ENOIOCTLCMD;
 386 }
 387
 388 EXPORT_SYMBOL_GPL(dccp_ioctl);
 389
 390 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 391                                    char __user *optval, int optlen)
 392 {
 393         struct dccp_sock *dp = dccp_sk(sk);
 394         struct dccp_service_list *sl = NULL;
 395
 396         if (service == DCCP_SERVICE_INVALID_VALUE ||
 397             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 398                 return -EINVAL;
 399
 400         if (optlen > sizeof(service)) {
 401                 sl = kmalloc(optlen, GFP_KERNEL);
 402                 if (sl == NULL)
 403                         return -ENOMEM;
 404
 405                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 406                 if (copy_from_user(sl->dccpsl_list,
 407                                    optval + sizeof(service),
 408                                    optlen - sizeof(service)) ||
 409                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 410                         kfree(sl);
 411                         return -EFAULT;
 412                 }
 413         }
 414
 415         lock_sock(sk);
 416         dp->dccps_service = service;
 417
 418         kfree(dp->dccps_service_list);
 419
 420         dp->dccps_service_list = sl;
 421         release_sock(sk);
 422         return 0;
 423 }
 424
 425 /* byte 1 is feature.  the rest is the preference list */
 426 static int dccp_setsockopt_change(struct sock *sk, int type,
 427                                   struct dccp_so_feat __user *optval)
 428 {
 429         struct dccp_so_feat opt;
 430         u8 *val;
 431         int rc;
 432
 433         if (copy_from_user(&opt, optval, sizeof(opt)))
 434                 return -EFAULT;
 435
 436         val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
 437         if (!val)
 438                 return -ENOMEM;
 439
 440         if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
 441                 rc = -EFAULT;
 442                 goto out_free_val;
 443         }
 444
 445         rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
 446                               val, opt.dccpsf_len, GFP_KERNEL);
 447         if (rc)
 448                 goto out_free_val;
 449
 450 out:
 451         return rc;
 452
 453 out_free_val:
 454         kfree(val);
 455         goto out;
 456 }
 457
 458 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 459                 char __user *optval, int optlen)
 460 {
 461         struct dccp_sock *dp;
 462         int err;
 463         int val;
 464
 465         if (optlen < sizeof(int))
 466                 return -EINVAL;
 467
 468         if (get_user(val, (int __user *)optval))
 469                 return -EFAULT;
 470
 471         if (optname == DCCP_SOCKOPT_SERVICE)
 472                 return dccp_setsockopt_service(sk, val, optval, optlen);
 473
 474         lock_sock(sk);
 475         dp = dccp_sk(sk);
 476         err = 0;
 477
 478         switch (optname) {
 479         case DCCP_SOCKOPT_PACKET_SIZE:
 480                 dp->dccps_packet_size = val;
 481                 break;
 482
 483         case DCCP_SOCKOPT_CHANGE_L:
 484                 if (optlen != sizeof(struct dccp_so_feat))
 485                         err = -EINVAL;
 486                 else
 487                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
 488                                                      (struct dccp_so_feat *)
 489                                                      optval);
 490                 break;
 491
 492         case DCCP_SOCKOPT_CHANGE_R:
 493                 if (optlen != sizeof(struct dccp_so_feat))
 494                         err = -EINVAL;
 495                 else
 496                         err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
 497                                                      (struct dccp_so_feat *)
 498                                                      optval);
 499                 break;
 500
 501         default:
 502                 err = -ENOPROTOOPT;
 503                 break;
 504         }
 505
 506         release_sock(sk);
 507         return err;
 508 }
 509
 510 int dccp_setsockopt(struct sock *sk, int level, int optname,
 511                     char __user *optval, int optlen)
 512 {
 513         if (level != SOL_DCCP)
 514                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 515                                                              optname, optval,
 516                                                              optlen);
 517         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 518 }
 519
 520 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 521
 522 #ifdef CONFIG_COMPAT
 523 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 524                            char __user *optval, int optlen)
 525 {
 526         if (level != SOL_DCCP)
 527                 return inet_csk_compat_setsockopt(sk, level, optname,
 528                                                   optval, optlen);
 529         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 530 }
 531
 532 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 533 #endif
 534
 535 static int dccp_getsockopt_service(struct sock *sk, int len,
 536                                    __be32 __user *optval,
 537                                    int __user *optlen)
 538 {
 539         const struct dccp_sock *dp = dccp_sk(sk);
 540         const struct dccp_service_list *sl;
 541         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 542
 543         lock_sock(sk);
 544         if (dccp_service_not_initialized(sk))
 545                 goto out;
 546
 547         if ((sl = dp->dccps_service_list) != NULL) {
 548                 slen = sl->dccpsl_nr * sizeof(u32);
 549                 total_len += slen;
 550         }
 551
 552         err = -EINVAL;
 553         if (total_len > len)
 554                 goto out;
 555
 556         err = 0;
 557         if (put_user(total_len, optlen) ||
 558             put_user(dp->dccps_service, optval) ||
 559             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 560                 err = -EFAULT;
 561 out:
 562         release_sock(sk);
 563         return err;
 564 }
 565
 566 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 567                     char __user *optval, int __user *optlen)
 568 {
 569         struct dccp_sock *dp;
 570         int val, len;
 571
 572         if (get_user(len, optlen))
 573                 return -EFAULT;
 574
 575         if (len < sizeof(int))
 576                 return -EINVAL;
 577
 578         dp = dccp_sk(sk);
 579
 580         switch (optname) {
 581         case DCCP_SOCKOPT_PACKET_SIZE:
 582                 val = dp->dccps_packet_size;
 583                 len = sizeof(dp->dccps_packet_size);
 584                 break;
 585         case DCCP_SOCKOPT_SERVICE:
 586                 return dccp_getsockopt_service(sk, len,
 587                                                (__be32 __user *)optval, optlen);
 588         case 128 ... 191:
 589                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 590                                              len, (u32 __user *)optval, optlen);
 591         case 192 ... 255:
 592                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 593                                              len, (u32 __user *)optval, optlen);
 594         default:
 595                 return -ENOPROTOOPT;
 596         }
 597
 598         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 599                 return -EFAULT;
 600
 601         return 0;
 602 }
 603
 604 int dccp_getsockopt(struct sock *sk, int level, int optname,
 605                     char __user *optval, int __user *optlen)
 606 {
 607         if (level != SOL_DCCP)
 608                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 609                                                              optname, optval,
 610                                                              optlen);
 611         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 612 }
 613
 614 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 615
 616 #ifdef CONFIG_COMPAT
 617 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 618                            char __user *optval, int __user *optlen)
 619 {
 620         if (level != SOL_DCCP)
 621                 return inet_csk_compat_getsockopt(sk, level, optname,
 622                                                   optval, optlen);
 623         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 624 }
 625
 626 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 627 #endif
 628
 629 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 630                  size_t len)
 631 {
 632         const struct dccp_sock *dp = dccp_sk(sk);
 633         const int flags = msg->msg_flags;
 634         const int noblock = flags & MSG_DONTWAIT;
 635         struct sk_buff *skb;
 636         int rc, size;
 637         long timeo;
 638
 639         if (len > dp->dccps_mss_cache)
 640                 return -EMSGSIZE;
 641
 642         lock_sock(sk);
 643         timeo = sock_sndtimeo(sk, noblock);
 644
 645         /*
 646          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 647          * so that the trick in dccp_rcv_request_sent_state_process.
 648          */
 649         /* Wait for a connection to finish. */
 650         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
 651                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 652                         goto out_release;
 653
 654         size = sk->sk_prot->max_header + len;
 655         release_sock(sk);
 656         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 657         lock_sock(sk);
 658         if (skb == NULL)
 659                 goto out_release;
 660
 661         skb_reserve(skb, sk->sk_prot->max_header);
 662         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 663         if (rc != 0)
 664                 goto out_discard;
 665
 666         rc = dccp_write_xmit(sk, skb, &timeo);
 667         /*
 668          * XXX we don't use sk_write_queue, so just discard the packet.
 669          *     Current plan however is to _use_ sk_write_queue with
 670          *     an algorith similar to tcp_sendmsg, where the main difference
 671          *     is that in DCCP we have to respect packet boundaries, so
 672          *     no coalescing of skbs.
 673          *
 674          *     This bug was _quickly_ found & fixed by just looking at an OSTRA
 675          *     generated callgraph 8) -acme
 676          */
 677 out_release:
 678         release_sock(sk);
 679         return rc ? : len;
 680 out_discard:
 681         kfree_skb(skb);
 682         goto out_release;
 683 }
 684
 685 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 686
 687 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 688                  size_t len, int nonblock, int flags, int *addr_len)
 689 {
 690         const struct dccp_hdr *dh;
 691         long timeo;
 692
 693         lock_sock(sk);
 694
 695         if (sk->sk_state == DCCP_LISTEN) {
 696                 len = -ENOTCONN;
 697                 goto out;
 698         }
 699
 700         timeo = sock_rcvtimeo(sk, nonblock);
 701
 702         do {
 703                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 704
 705                 if (skb == NULL)
 706                         goto verify_sock_status;
 707
 708                 dh = dccp_hdr(skb);
 709
 710                 if (dh->dccph_type == DCCP_PKT_DATA ||
 711                     dh->dccph_type == DCCP_PKT_DATAACK)
 712                         goto found_ok_skb;
 713
 714                 if (dh->dccph_type == DCCP_PKT_RESET ||
 715                     dh->dccph_type == DCCP_PKT_CLOSE) {
 716                         dccp_pr_debug("found fin ok!\n");
 717                         len = 0;
 718                         goto found_fin_ok;
 719                 }
 720                 dccp_pr_debug("packet_type=%s\n",
 721                               dccp_packet_name(dh->dccph_type));
 722                 sk_eat_skb(sk, skb);
 723 verify_sock_status:
 724                 if (sock_flag(sk, SOCK_DONE)) {
 725                         len = 0;
 726                         break;
 727                 }
 728
 729                 if (sk->sk_err) {
 730                         len = sock_error(sk);
 731                         break;
 732                 }
 733
 734                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 735                         len = 0;
 736                         break;
 737                 }
 738
 739                 if (sk->sk_state == DCCP_CLOSED) {
 740                         if (!sock_flag(sk, SOCK_DONE)) {
 741                                 /* This occurs when user tries to read
 742                                  * from never connected socket.
 743                                  */
 744                                 len = -ENOTCONN;
 745                                 break;
 746                         }
 747                         len = 0;
 748                         break;
 749                 }
 750
 751                 if (!timeo) {
 752                         len = -EAGAIN;
 753                         break;
 754                 }
 755
 756                 if (signal_pending(current)) {
 757                         len = sock_intr_errno(timeo);
 758                         break;
 759                 }
 760
 761                 sk_wait_data(sk, &timeo);
 762                 continue;
 763         found_ok_skb:
 764                 if (len > skb->len)
 765                         len = skb->len;
 766                 else if (len < skb->len)
 767                         msg->msg_flags |= MSG_TRUNC;
 768
 769                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 770                         /* Exception. Bailout! */
 771                         len = -EFAULT;
 772                         break;
 773                 }
 774         found_fin_ok:
 775                 if (!(flags & MSG_PEEK))
 776                         sk_eat_skb(sk, skb);
 777                 break;
 778         } while (1);
 779 out:
 780         release_sock(sk);
 781         return len;
 782 }
 783
 784 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 785
 786 int inet_dccp_listen(struct socket *sock, int backlog)
 787 {
 788         struct sock *sk = sock->sk;
 789         unsigned char old_state;
 790         int err;
 791
 792         lock_sock(sk);
 793
 794         err = -EINVAL;
 795         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 796                 goto out;
 797
 798         old_state = sk->sk_state;
 799         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 800                 goto out;
 801
 802         /* Really, if the socket is already in listen state
 803          * we can only allow the backlog to be adjusted.
 804          */
 805         if (old_state != DCCP_LISTEN) {
 806                 /*
 807                  * FIXME: here it probably should be sk->sk_prot->listen_start
 808                  * see tcp_listen_start
 809                  */
 810                 err = dccp_listen_start(sk);
 811                 if (err)
 812                         goto out;
 813         }
 814         sk->sk_max_ack_backlog = backlog;
 815         err = 0;
 816
 817 out:
 818         release_sock(sk);
 819         return err;
 820 }
 821
 822 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 823
 824 static const unsigned char dccp_new_state[] = {
 825         /* current state:   new state:      action:     */
 826         [0]               = DCCP_CLOSED,
 827         [DCCP_OPEN]       = DCCP_CLOSING | DCCP_ACTION_FIN,
 828         [DCCP_REQUESTING] = DCCP_CLOSED,
 829         [DCCP_PARTOPEN]   = DCCP_CLOSING | DCCP_ACTION_FIN,
 830         [DCCP_LISTEN]     = DCCP_CLOSED,
 831         [DCCP_RESPOND]    = DCCP_CLOSED,
 832         [DCCP_CLOSING]    = DCCP_CLOSED,
 833         [DCCP_TIME_WAIT]  = DCCP_CLOSED,
 834         [DCCP_CLOSED]     = DCCP_CLOSED,
 835 };
 836
 837 static int dccp_close_state(struct sock *sk)
 838 {
 839         const int next = dccp_new_state[sk->sk_state];
 840         const int ns = next & DCCP_STATE_MASK;
 841
 842         if (ns != sk->sk_state)
 843                 dccp_set_state(sk, ns);
 844
 845         return next & DCCP_ACTION_FIN;
 846 }
 847
 848 void dccp_close(struct sock *sk, long timeout)
 849 {
 850         struct sk_buff *skb;
 851
 852         lock_sock(sk);
 853
 854         sk->sk_shutdown = SHUTDOWN_MASK;
 855
 856         if (sk->sk_state == DCCP_LISTEN) {
 857                 dccp_set_state(sk, DCCP_CLOSED);
 858
 859                 /* Special case. */
 860                 inet_csk_listen_stop(sk);
 861
 862                 goto adjudge_to_death;
 863         }
 864
 865         /*
 866          * We need to flush the recv. buffs.  We do this only on the
 867          * descriptor close, not protocol-sourced closes, because the
 868           *reader process may not have drained the data yet!
 869          */
 870         /* FIXME: check for unread data */
 871         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 872                 __kfree_skb(skb);
 873         }
 874
 875         if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 876                 /* Check zero linger _after_ checking for unread data. */
 877                 sk->sk_prot->disconnect(sk, 0);
 878         } else if (dccp_close_state(sk)) {
 879                 dccp_send_close(sk, 1);
 880         }
 881
 882         sk_stream_wait_close(sk, timeout);
 883
 884 adjudge_to_death:
 885         /*
 886          * It is the last release_sock in its life. It will remove backlog.
 887          */
 888         release_sock(sk);
 889         /*
 890          * Now socket is owned by kernel and we acquire BH lock
 891          * to finish close. No need to check for user refs.
 892          */
 893         local_bh_disable();
 894         bh_lock_sock(sk);
 895         BUG_TRAP(!sock_owned_by_user(sk));
 896
 897         sock_hold(sk);
 898         sock_orphan(sk);
 899
 900         /*
 901          * The last release_sock may have processed the CLOSE or RESET
 902          * packet moving sock to CLOSED state, if not we have to fire
 903          * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
 904          * in draft-ietf-dccp-spec-11. -acme
 905          */
 906         if (sk->sk_state == DCCP_CLOSING) {
 907                 /* FIXME: should start at 2 * RTT */
 908                 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
 909                 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 910                                           inet_csk(sk)->icsk_rto,
 911                                           DCCP_RTO_MAX);
 912 #if 0
 913                 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
 914                 dccp_set_state(sk, DCCP_CLOSED);
 915 #endif
 916         }
 917
 918         atomic_inc(sk->sk_prot->orphan_count);
 919         if (sk->sk_state == DCCP_CLOSED)
 920                 inet_csk_destroy_sock(sk);
 921
 922         /* Otherwise, socket is reprieved until protocol close. */
 923
 924         bh_unlock_sock(sk);
 925         local_bh_enable();
 926         sock_put(sk);
 927 }
 928
 929 EXPORT_SYMBOL_GPL(dccp_close);
 930
 931 void dccp_shutdown(struct sock *sk, int how)
 932 {
 933         dccp_pr_debug("entry\n");
 934 }
 935
 936 EXPORT_SYMBOL_GPL(dccp_shutdown);
 937
 938 static int __init dccp_mib_init(void)
 939 {
 940         int rc = -ENOMEM;
 941
 942         dccp_statistics[0] = alloc_percpu(struct dccp_mib);
 943         if (dccp_statistics[0] == NULL)
 944                 goto out;
 945
 946         dccp_statistics[1] = alloc_percpu(struct dccp_mib);
 947         if (dccp_statistics[1] == NULL)
 948                 goto out_free_one;
 949
 950         rc = 0;
 951 out:
 952         return rc;
 953 out_free_one:
 954         free_percpu(dccp_statistics[0]);
 955         dccp_statistics[0] = NULL;
 956         goto out;
 957
 958 }
 959
 960 static void dccp_mib_exit(void)
 961 {
 962         free_percpu(dccp_statistics[0]);
 963         free_percpu(dccp_statistics[1]);
 964         dccp_statistics[0] = dccp_statistics[1] = NULL;
 965 }
 966
 967 static int thash_entries;
 968 module_param(thash_entries, int, 0444);
 969 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 970
 971 #ifdef CONFIG_IP_DCCP_DEBUG
 972 int dccp_debug;
 973 module_param(dccp_debug, int, 0444);
 974 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 975
 976 EXPORT_SYMBOL_GPL(dccp_debug);
 977 #endif
 978
 979 static int __init dccp_init(void)
 980 {
 981         unsigned long goal;
 982         int ehash_order, bhash_order, i;
 983         int rc = -ENOBUFS;
 984
 985         dccp_hashinfo.bind_bucket_cachep =
 986                 kmem_cache_create("dccp_bind_bucket",
 987                                   sizeof(struct inet_bind_bucket), 0,
 988                                   SLAB_HWCACHE_ALIGN, NULL, NULL);
 989         if (!dccp_hashinfo.bind_bucket_cachep)
 990                 goto out;
 991
 992         /*
 993          * Size and allocate the main established and bind bucket
 994          * hash tables.
 995          *
 996          * The methodology is similar to that of the buffer cache.
 997          */
 998         if (num_physpages >= (128 * 1024))
 999                 goal = num_physpages >> (21 - PAGE_SHIFT);
1000         else
1001                 goal = num_physpages >> (23 - PAGE_SHIFT);
1002
1003         if (thash_entries)
1004                 goal = (thash_entries *
1005                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1006         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1007                 ;
1008         do {
1009                 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1010                                         sizeof(struct inet_ehash_bucket);
1011                 dccp_hashinfo.ehash_size >>= 1;
1012                 while (dccp_hashinfo.ehash_size &
1013                        (dccp_hashinfo.ehash_size - 1))
1014                         dccp_hashinfo.ehash_size--;
1015                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1016                         __get_free_pages(GFP_ATOMIC, ehash_order);
1017         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1018
1019         if (!dccp_hashinfo.ehash) {
1020                 printk(KERN_CRIT "Failed to allocate DCCP "
1021                                  "established hash table\n");
1022                 goto out_free_bind_bucket_cachep;
1023         }
1024
1025         for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
1026                 rwlock_init(&dccp_hashinfo.ehash[i].lock);
1027                 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
1028         }
1029
1030         bhash_order = ehash_order;
1031
1032         do {
1033                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1034                                         sizeof(struct inet_bind_hashbucket);
1035                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1036                     bhash_order > 0)
1037                         continue;
1038                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1039                         __get_free_pages(GFP_ATOMIC, bhash_order);
1040         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1041
1042         if (!dccp_hashinfo.bhash) {
1043                 printk(KERN_CRIT "Failed to allocate DCCP bind hash table\n");
1044                 goto out_free_dccp_ehash;
1045         }
1046
1047         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1048                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1049                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1050         }
1051
1052         rc = dccp_mib_init();
1053         if (rc)
1054                 goto out_free_dccp_bhash;
1055
1056         rc = dccp_ackvec_init();
1057         if (rc)
1058                 goto out_free_dccp_mib;
1059
1060         rc = dccp_sysctl_init();
1061         if (rc)
1062                 goto out_ackvec_exit;
1063 out:
1064         return rc;
1065 out_ackvec_exit:
1066         dccp_ackvec_exit();
1067 out_free_dccp_mib:
1068         dccp_mib_exit();
1069 out_free_dccp_bhash:
1070         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1071         dccp_hashinfo.bhash = NULL;
1072 out_free_dccp_ehash:
1073         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1074         dccp_hashinfo.ehash = NULL;
1075 out_free_bind_bucket_cachep:
1076         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1077         dccp_hashinfo.bind_bucket_cachep = NULL;
1078         goto out;
1079 }
1080
1081 static void __exit dccp_fini(void)
1082 {
1083         dccp_mib_exit();
1084         free_pages((unsigned long)dccp_hashinfo.bhash,
1085                    get_order(dccp_hashinfo.bhash_size *
1086                              sizeof(struct inet_bind_hashbucket)));
1087         free_pages((unsigned long)dccp_hashinfo.ehash,
1088                    get_order(dccp_hashinfo.ehash_size *
1089                              sizeof(struct inet_ehash_bucket)));
1090         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1091         dccp_ackvec_exit();
1092         dccp_sysctl_exit();
1093 }
1094
1095 module_init(dccp_init);
1096 module_exit(dccp_fini);
1097
1098 MODULE_LICENSE("GPL");
1099 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1100 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");