net/dccp/proto.c

   1 /*
   2  *  net/dccp/proto.c
   3  *
   4  *  An implementation of the DCCP protocol
   5  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify it
   8  *      under the terms of the GNU General Public License version 2 as
   9  *      published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/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 <linux/slab.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/ioctls.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 struct percpu_counter dccp_orphan_count;
  45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
  46
  47 struct inet_hashinfo dccp_hashinfo;
  48 EXPORT_SYMBOL_GPL(dccp_hashinfo);
  49
  50 /* the maximum queue length for tx in packets. 0 is no limit */
  51 int sysctl_dccp_tx_qlen __read_mostly = 5;
  52
  53 void dccp_set_state(struct sock *sk, const int state)
  54 {
  55         const int oldstate = sk->sk_state;
  56
  57         dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
  58                       dccp_state_name(oldstate), dccp_state_name(state));
  59         WARN_ON(state == oldstate);
  60
  61         switch (state) {
  62         case DCCP_OPEN:
  63                 if (oldstate != DCCP_OPEN)
  64                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  65                 /* Client retransmits all Confirm options until entering OPEN */
  66                 if (oldstate == DCCP_PARTOPEN)
  67                         dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
  68                 break;
  69
  70         case DCCP_CLOSED:
  71                 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
  72                     oldstate == DCCP_CLOSING)
  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(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 static void dccp_finish_passive_close(struct sock *sk)
  94 {
  95         switch (sk->sk_state) {
  96         case DCCP_PASSIVE_CLOSE:
  97                 /* Node (client or server) has received Close packet. */
  98                 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
  99                 dccp_set_state(sk, DCCP_CLOSED);
 100                 break;
 101         case DCCP_PASSIVE_CLOSEREQ:
 102                 /*
 103                  * Client received CloseReq. We set the `active' flag so that
 104                  * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
 105                  */
 106                 dccp_send_close(sk, 1);
 107                 dccp_set_state(sk, DCCP_CLOSING);
 108         }
 109 }
 110
 111 void dccp_done(struct sock *sk)
 112 {
 113         dccp_set_state(sk, DCCP_CLOSED);
 114         dccp_clear_xmit_timers(sk);
 115
 116         sk->sk_shutdown = SHUTDOWN_MASK;
 117
 118         if (!sock_flag(sk, SOCK_DEAD))
 119                 sk->sk_state_change(sk);
 120         else
 121                 inet_csk_destroy_sock(sk);
 122 }
 123
 124 EXPORT_SYMBOL_GPL(dccp_done);
 125
 126 const char *dccp_packet_name(const int type)
 127 {
 128         static const char *const dccp_packet_names[] = {
 129                 [DCCP_PKT_REQUEST]  = "REQUEST",
 130                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 131                 [DCCP_PKT_DATA]     = "DATA",
 132                 [DCCP_PKT_ACK]      = "ACK",
 133                 [DCCP_PKT_DATAACK]  = "DATAACK",
 134                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 135                 [DCCP_PKT_CLOSE]    = "CLOSE",
 136                 [DCCP_PKT_RESET]    = "RESET",
 137                 [DCCP_PKT_SYNC]     = "SYNC",
 138                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 139         };
 140
 141         if (type >= DCCP_NR_PKT_TYPES)
 142                 return "INVALID";
 143         else
 144                 return dccp_packet_names[type];
 145 }
 146
 147 EXPORT_SYMBOL_GPL(dccp_packet_name);
 148
 149 const char *dccp_state_name(const int state)
 150 {
 151         static const char *const dccp_state_names[] = {
 152         [DCCP_OPEN]             = "OPEN",
 153         [DCCP_REQUESTING]       = "REQUESTING",
 154         [DCCP_PARTOPEN]         = "PARTOPEN",
 155         [DCCP_LISTEN]           = "LISTEN",
 156         [DCCP_RESPOND]          = "RESPOND",
 157         [DCCP_CLOSING]          = "CLOSING",
 158         [DCCP_ACTIVE_CLOSEREQ]  = "CLOSEREQ",
 159         [DCCP_PASSIVE_CLOSE]    = "PASSIVE_CLOSE",
 160         [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
 161         [DCCP_TIME_WAIT]        = "TIME_WAIT",
 162         [DCCP_CLOSED]           = "CLOSED",
 163         };
 164
 165         if (state >= DCCP_MAX_STATES)
 166                 return "INVALID STATE!";
 167         else
 168                 return dccp_state_names[state];
 169 }
 170
 171 EXPORT_SYMBOL_GPL(dccp_state_name);
 172
 173 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 174 {
 175         struct dccp_sock *dp = dccp_sk(sk);
 176         struct inet_connection_sock *icsk = inet_csk(sk);
 177
 178         icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 179         icsk->icsk_syn_retries  = sysctl_dccp_request_retries;
 180         sk->sk_state            = DCCP_CLOSED;
 181         sk->sk_write_space      = dccp_write_space;
 182         icsk->icsk_sync_mss     = dccp_sync_mss;
 183         dp->dccps_mss_cache     = 536;
 184         dp->dccps_rate_last     = jiffies;
 185         dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 186         dp->dccps_service       = DCCP_SERVICE_CODE_IS_ABSENT;
 187         dp->dccps_l_ack_ratio   = dp->dccps_r_ack_ratio = 1;
 188
 189         dccp_init_xmit_timers(sk);
 190
 191         INIT_LIST_HEAD(&dp->dccps_featneg);
 192         /* control socket doesn't need feat nego */
 193         if (likely(ctl_sock_initialized))
 194                 return dccp_feat_init(sk);
 195         return 0;
 196 }
 197
 198 EXPORT_SYMBOL_GPL(dccp_init_sock);
 199
 200 void dccp_destroy_sock(struct sock *sk)
 201 {
 202         struct dccp_sock *dp = dccp_sk(sk);
 203
 204         /*
 205          * DCCP doesn't use sk_write_queue, just sk_send_head
 206          * for retransmissions
 207          */
 208         if (sk->sk_send_head != NULL) {
 209                 kfree_skb(sk->sk_send_head);
 210                 sk->sk_send_head = NULL;
 211         }
 212
 213         /* Clean up a referenced DCCP bind bucket. */
 214         if (inet_csk(sk)->icsk_bind_hash != NULL)
 215                 inet_put_port(sk);
 216
 217         kfree(dp->dccps_service_list);
 218         dp->dccps_service_list = NULL;
 219
 220         if (dp->dccps_hc_rx_ackvec != NULL) {
 221                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 222                 dp->dccps_hc_rx_ackvec = NULL;
 223         }
 224         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 225         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 226         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 227
 228         /* clean up feature negotiation state */
 229         dccp_feat_list_purge(&dp->dccps_featneg);
 230 }
 231
 232 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 233
 234 static inline int dccp_listen_start(struct sock *sk, int backlog)
 235 {
 236         struct dccp_sock *dp = dccp_sk(sk);
 237
 238         dp->dccps_role = DCCP_ROLE_LISTEN;
 239         /* do not start to listen if feature negotiation setup fails */
 240         if (dccp_feat_finalise_settings(dp))
 241                 return -EPROTO;
 242         return inet_csk_listen_start(sk, backlog);
 243 }
 244
 245 static inline int dccp_need_reset(int state)
 246 {
 247         return state != DCCP_CLOSED && state != DCCP_LISTEN &&
 248                state != DCCP_REQUESTING;
 249 }
 250
 251 int dccp_disconnect(struct sock *sk, int flags)
 252 {
 253         struct inet_connection_sock *icsk = inet_csk(sk);
 254         struct inet_sock *inet = inet_sk(sk);
 255         int err = 0;
 256         const int old_state = sk->sk_state;
 257
 258         if (old_state != DCCP_CLOSED)
 259                 dccp_set_state(sk, DCCP_CLOSED);
 260
 261         /*
 262          * This corresponds to the ABORT function of RFC793, sec. 3.8
 263          * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
 264          */
 265         if (old_state == DCCP_LISTEN) {
 266                 inet_csk_listen_stop(sk);
 267         } else if (dccp_need_reset(old_state)) {
 268                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 269                 sk->sk_err = ECONNRESET;
 270         } else if (old_state == DCCP_REQUESTING)
 271                 sk->sk_err = ECONNRESET;
 272
 273         dccp_clear_xmit_timers(sk);
 274
 275         __skb_queue_purge(&sk->sk_receive_queue);
 276         __skb_queue_purge(&sk->sk_write_queue);
 277         if (sk->sk_send_head != NULL) {
 278                 __kfree_skb(sk->sk_send_head);
 279                 sk->sk_send_head = NULL;
 280         }
 281
 282         inet->inet_dport = 0;
 283
 284         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 285                 inet_reset_saddr(sk);
 286
 287         sk->sk_shutdown = 0;
 288         sock_reset_flag(sk, SOCK_DONE);
 289
 290         icsk->icsk_backoff = 0;
 291         inet_csk_delack_init(sk);
 292         __sk_dst_reset(sk);
 293
 294         WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
 295
 296         sk->sk_error_report(sk);
 297         return err;
 298 }
 299
 300 EXPORT_SYMBOL_GPL(dccp_disconnect);
 301
 302 /*
 303  *      Wait for a DCCP event.
 304  *
 305  *      Note that we don't need to lock the socket, as the upper poll layers
 306  *      take care of normal races (between the test and the event) and we don't
 307  *      go look at any of the socket buffers directly.
 308  */
 309 unsigned int dccp_poll(struct file *file, struct socket *sock,
 310                        poll_table *wait)
 311 {
 312         unsigned int mask;
 313         struct sock *sk = sock->sk;
 314
 315         sock_poll_wait(file, sk_sleep(sk), wait);
 316         if (sk->sk_state == DCCP_LISTEN)
 317                 return inet_csk_listen_poll(sk);
 318
 319         /* Socket is not locked. We are protected from async events
 320            by poll logic and correct handling of state changes
 321            made by another threads is impossible in any case.
 322          */
 323
 324         mask = 0;
 325         if (sk->sk_err)
 326                 mask = POLLERR;
 327
 328         if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
 329                 mask |= POLLHUP;
 330         if (sk->sk_shutdown & RCV_SHUTDOWN)
 331                 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 332
 333         /* Connected? */
 334         if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 335                 if (atomic_read(&sk->sk_rmem_alloc) > 0)
 336                         mask |= POLLIN | POLLRDNORM;
 337
 338                 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 339                         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 340                                 mask |= POLLOUT | POLLWRNORM;
 341                         } else {  /* send SIGIO later */
 342                                 set_bit(SOCK_ASYNC_NOSPACE,
 343                                         &sk->sk_socket->flags);
 344                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 345
 346                                 /* Race breaker. If space is freed after
 347                                  * wspace test but before the flags are set,
 348                                  * IO signal will be lost.
 349                                  */
 350                                 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
 351                                         mask |= POLLOUT | POLLWRNORM;
 352                         }
 353                 }
 354         }
 355         return mask;
 356 }
 357
 358 EXPORT_SYMBOL_GPL(dccp_poll);
 359
 360 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 361 {
 362         int rc = -ENOTCONN;
 363
 364         lock_sock(sk);
 365
 366         if (sk->sk_state == DCCP_LISTEN)
 367                 goto out;
 368
 369         switch (cmd) {
 370         case SIOCINQ: {
 371                 struct sk_buff *skb;
 372                 unsigned long amount = 0;
 373
 374                 skb = skb_peek(&sk->sk_receive_queue);
 375                 if (skb != NULL) {
 376                         /*
 377                          * We will only return the amount of this packet since
 378                          * that is all that will be read.
 379                          */
 380                         amount = skb->len;
 381                 }
 382                 rc = put_user(amount, (int __user *)arg);
 383         }
 384                 break;
 385         default:
 386                 rc = -ENOIOCTLCMD;
 387                 break;
 388         }
 389 out:
 390         release_sock(sk);
 391         return rc;
 392 }
 393
 394 EXPORT_SYMBOL_GPL(dccp_ioctl);
 395
 396 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 397                                    char __user *optval, unsigned int optlen)
 398 {
 399         struct dccp_sock *dp = dccp_sk(sk);
 400         struct dccp_service_list *sl = NULL;
 401
 402         if (service == DCCP_SERVICE_INVALID_VALUE ||
 403             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 404                 return -EINVAL;
 405
 406         if (optlen > sizeof(service)) {
 407                 sl = kmalloc(optlen, GFP_KERNEL);
 408                 if (sl == NULL)
 409                         return -ENOMEM;
 410
 411                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 412                 if (copy_from_user(sl->dccpsl_list,
 413                                    optval + sizeof(service),
 414                                    optlen - sizeof(service)) ||
 415                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 416                         kfree(sl);
 417                         return -EFAULT;
 418                 }
 419         }
 420
 421         lock_sock(sk);
 422         dp->dccps_service = service;
 423
 424         kfree(dp->dccps_service_list);
 425
 426         dp->dccps_service_list = sl;
 427         release_sock(sk);
 428         return 0;
 429 }
 430
 431 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
 432 {
 433         u8 *list, len;
 434         int i, rc;
 435
 436         if (cscov < 0 || cscov > 15)
 437                 return -EINVAL;
 438         /*
 439          * Populate a list of permissible values, in the range cscov...15. This
 440          * is necessary since feature negotiation of single values only works if
 441          * both sides incidentally choose the same value. Since the list starts
 442          * lowest-value first, negotiation will pick the smallest shared value.
 443          */
 444         if (cscov == 0)
 445                 return 0;
 446         len = 16 - cscov;
 447
 448         list = kmalloc(len, GFP_KERNEL);
 449         if (list == NULL)
 450                 return -ENOBUFS;
 451
 452         for (i = 0; i < len; i++)
 453                 list[i] = cscov++;
 454
 455         rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
 456
 457         if (rc == 0) {
 458                 if (rx)
 459                         dccp_sk(sk)->dccps_pcrlen = cscov;
 460                 else
 461                         dccp_sk(sk)->dccps_pcslen = cscov;
 462         }
 463         kfree(list);
 464         return rc;
 465 }
 466
 467 static int dccp_setsockopt_ccid(struct sock *sk, int type,
 468                                 char __user *optval, unsigned int optlen)
 469 {
 470         u8 *val;
 471         int rc = 0;
 472
 473         if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
 474                 return -EINVAL;
 475
 476         val = kmalloc(optlen, GFP_KERNEL);
 477         if (val == NULL)
 478                 return -ENOMEM;
 479
 480         if (copy_from_user(val, optval, optlen)) {
 481                 kfree(val);
 482                 return -EFAULT;
 483         }
 484
 485         lock_sock(sk);
 486         if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
 487                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
 488
 489         if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
 490                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
 491         release_sock(sk);
 492
 493         kfree(val);
 494         return rc;
 495 }
 496
 497 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 498                 char __user *optval, unsigned int optlen)
 499 {
 500         struct dccp_sock *dp = dccp_sk(sk);
 501         int val, err = 0;
 502
 503         switch (optname) {
 504         case DCCP_SOCKOPT_PACKET_SIZE:
 505                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 506                 return 0;
 507         case DCCP_SOCKOPT_CHANGE_L:
 508         case DCCP_SOCKOPT_CHANGE_R:
 509                 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
 510                 return 0;
 511         case DCCP_SOCKOPT_CCID:
 512         case DCCP_SOCKOPT_RX_CCID:
 513         case DCCP_SOCKOPT_TX_CCID:
 514                 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
 515         }
 516
 517         if (optlen < (int)sizeof(int))
 518                 return -EINVAL;
 519
 520         if (get_user(val, (int __user *)optval))
 521                 return -EFAULT;
 522
 523         if (optname == DCCP_SOCKOPT_SERVICE)
 524                 return dccp_setsockopt_service(sk, val, optval, optlen);
 525
 526         lock_sock(sk);
 527         switch (optname) {
 528         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 529                 if (dp->dccps_role != DCCP_ROLE_SERVER)
 530                         err = -EOPNOTSUPP;
 531                 else
 532                         dp->dccps_server_timewait = (val != 0);
 533                 break;
 534         case DCCP_SOCKOPT_SEND_CSCOV:
 535                 err = dccp_setsockopt_cscov(sk, val, false);
 536                 break;
 537         case DCCP_SOCKOPT_RECV_CSCOV:
 538                 err = dccp_setsockopt_cscov(sk, val, true);
 539                 break;
 540         default:
 541                 err = -ENOPROTOOPT;
 542                 break;
 543         }
 544         release_sock(sk);
 545
 546         return err;
 547 }
 548
 549 int dccp_setsockopt(struct sock *sk, int level, int optname,
 550                     char __user *optval, unsigned int optlen)
 551 {
 552         if (level != SOL_DCCP)
 553                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 554                                                              optname, optval,
 555                                                              optlen);
 556         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 557 }
 558
 559 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 560
 561 #ifdef CONFIG_COMPAT
 562 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 563                            char __user *optval, unsigned int optlen)
 564 {
 565         if (level != SOL_DCCP)
 566                 return inet_csk_compat_setsockopt(sk, level, optname,
 567                                                   optval, optlen);
 568         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 569 }
 570
 571 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 572 #endif
 573
 574 static int dccp_getsockopt_service(struct sock *sk, int len,
 575                                    __be32 __user *optval,
 576                                    int __user *optlen)
 577 {
 578         const struct dccp_sock *dp = dccp_sk(sk);
 579         const struct dccp_service_list *sl;
 580         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 581
 582         lock_sock(sk);
 583         if ((sl = dp->dccps_service_list) != NULL) {
 584                 slen = sl->dccpsl_nr * sizeof(u32);
 585                 total_len += slen;
 586         }
 587
 588         err = -EINVAL;
 589         if (total_len > len)
 590                 goto out;
 591
 592         err = 0;
 593         if (put_user(total_len, optlen) ||
 594             put_user(dp->dccps_service, optval) ||
 595             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 596                 err = -EFAULT;
 597 out:
 598         release_sock(sk);
 599         return err;
 600 }
 601
 602 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 603                     char __user *optval, int __user *optlen)
 604 {
 605         struct dccp_sock *dp;
 606         int val, len;
 607
 608         if (get_user(len, optlen))
 609                 return -EFAULT;
 610
 611         if (len < (int)sizeof(int))
 612                 return -EINVAL;
 613
 614         dp = dccp_sk(sk);
 615
 616         switch (optname) {
 617         case DCCP_SOCKOPT_PACKET_SIZE:
 618                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 619                 return 0;
 620         case DCCP_SOCKOPT_SERVICE:
 621                 return dccp_getsockopt_service(sk, len,
 622                                                (__be32 __user *)optval, optlen);
 623         case DCCP_SOCKOPT_GET_CUR_MPS:
 624                 val = dp->dccps_mss_cache;
 625                 break;
 626         case DCCP_SOCKOPT_AVAILABLE_CCIDS:
 627                 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
 628         case DCCP_SOCKOPT_TX_CCID:
 629                 val = ccid_get_current_tx_ccid(dp);
 630                 if (val < 0)
 631                         return -ENOPROTOOPT;
 632                 break;
 633         case DCCP_SOCKOPT_RX_CCID:
 634                 val = ccid_get_current_rx_ccid(dp);
 635                 if (val < 0)
 636                         return -ENOPROTOOPT;
 637                 break;
 638         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 639                 val = dp->dccps_server_timewait;
 640                 break;
 641         case DCCP_SOCKOPT_SEND_CSCOV:
 642                 val = dp->dccps_pcslen;
 643                 break;
 644         case DCCP_SOCKOPT_RECV_CSCOV:
 645                 val = dp->dccps_pcrlen;
 646                 break;
 647         case 128 ... 191:
 648                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 649                                              len, (u32 __user *)optval, optlen);
 650         case 192 ... 255:
 651                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 652                                              len, (u32 __user *)optval, optlen);
 653         default:
 654                 return -ENOPROTOOPT;
 655         }
 656
 657         len = sizeof(val);
 658         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 659                 return -EFAULT;
 660
 661         return 0;
 662 }
 663
 664 int dccp_getsockopt(struct sock *sk, int level, int optname,
 665                     char __user *optval, int __user *optlen)
 666 {
 667         if (level != SOL_DCCP)
 668                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 669                                                              optname, optval,
 670                                                              optlen);
 671         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 672 }
 673
 674 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 675
 676 #ifdef CONFIG_COMPAT
 677 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 678                            char __user *optval, int __user *optlen)
 679 {
 680         if (level != SOL_DCCP)
 681                 return inet_csk_compat_getsockopt(sk, level, optname,
 682                                                   optval, optlen);
 683         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 684 }
 685
 686 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 687 #endif
 688
 689 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 690                  size_t len)
 691 {
 692         const struct dccp_sock *dp = dccp_sk(sk);
 693         const int flags = msg->msg_flags;
 694         const int noblock = flags & MSG_DONTWAIT;
 695         struct sk_buff *skb;
 696         int rc, size;
 697         long timeo;
 698
 699         if (len > dp->dccps_mss_cache)
 700                 return -EMSGSIZE;
 701
 702         lock_sock(sk);
 703
 704         if (sysctl_dccp_tx_qlen &&
 705             (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
 706                 rc = -EAGAIN;
 707                 goto out_release;
 708         }
 709
 710         timeo = sock_sndtimeo(sk, noblock);
 711
 712         /*
 713          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 714          * so that the trick in dccp_rcv_request_sent_state_process.
 715          */
 716         /* Wait for a connection to finish. */
 717         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 718                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 719                         goto out_release;
 720
 721         size = sk->sk_prot->max_header + len;
 722         release_sock(sk);
 723         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 724         lock_sock(sk);
 725         if (skb == NULL)
 726                 goto out_release;
 727
 728         skb_reserve(skb, sk->sk_prot->max_header);
 729         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 730         if (rc != 0)
 731                 goto out_discard;
 732
 733         skb_queue_tail(&sk->sk_write_queue, skb);
 734         dccp_write_xmit(sk,0);
 735 out_release:
 736         release_sock(sk);
 737         return rc ? : len;
 738 out_discard:
 739         kfree_skb(skb);
 740         goto out_release;
 741 }
 742
 743 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 744
 745 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 746                  size_t len, int nonblock, int flags, int *addr_len)
 747 {
 748         const struct dccp_hdr *dh;
 749         long timeo;
 750
 751         lock_sock(sk);
 752
 753         if (sk->sk_state == DCCP_LISTEN) {
 754                 len = -ENOTCONN;
 755                 goto out;
 756         }
 757
 758         timeo = sock_rcvtimeo(sk, nonblock);
 759
 760         do {
 761                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 762
 763                 if (skb == NULL)
 764                         goto verify_sock_status;
 765
 766                 dh = dccp_hdr(skb);
 767
 768                 switch (dh->dccph_type) {
 769                 case DCCP_PKT_DATA:
 770                 case DCCP_PKT_DATAACK:
 771                         goto found_ok_skb;
 772
 773                 case DCCP_PKT_CLOSE:
 774                 case DCCP_PKT_CLOSEREQ:
 775                         if (!(flags & MSG_PEEK))
 776                                 dccp_finish_passive_close(sk);
 777                         /* fall through */
 778                 case DCCP_PKT_RESET:
 779                         dccp_pr_debug("found fin (%s) ok!\n",
 780                                       dccp_packet_name(dh->dccph_type));
 781                         len = 0;
 782                         goto found_fin_ok;
 783                 default:
 784                         dccp_pr_debug("packet_type=%s\n",
 785                                       dccp_packet_name(dh->dccph_type));
 786                         sk_eat_skb(sk, skb, 0);
 787                 }
 788 verify_sock_status:
 789                 if (sock_flag(sk, SOCK_DONE)) {
 790                         len = 0;
 791                         break;
 792                 }
 793
 794                 if (sk->sk_err) {
 795                         len = sock_error(sk);
 796                         break;
 797                 }
 798
 799                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 800                         len = 0;
 801                         break;
 802                 }
 803
 804                 if (sk->sk_state == DCCP_CLOSED) {
 805                         if (!sock_flag(sk, SOCK_DONE)) {
 806                                 /* This occurs when user tries to read
 807                                  * from never connected socket.
 808                                  */
 809                                 len = -ENOTCONN;
 810                                 break;
 811                         }
 812                         len = 0;
 813                         break;
 814                 }
 815
 816                 if (!timeo) {
 817                         len = -EAGAIN;
 818                         break;
 819                 }
 820
 821                 if (signal_pending(current)) {
 822                         len = sock_intr_errno(timeo);
 823                         break;
 824                 }
 825
 826                 sk_wait_data(sk, &timeo);
 827                 continue;
 828         found_ok_skb:
 829                 if (len > skb->len)
 830                         len = skb->len;
 831                 else if (len < skb->len)
 832                         msg->msg_flags |= MSG_TRUNC;
 833
 834                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 835                         /* Exception. Bailout! */
 836                         len = -EFAULT;
 837                         break;
 838                 }
 839                 if (flags & MSG_TRUNC)
 840                         len = skb->len;
 841         found_fin_ok:
 842                 if (!(flags & MSG_PEEK))
 843                         sk_eat_skb(sk, skb, 0);
 844                 break;
 845         } while (1);
 846 out:
 847         release_sock(sk);
 848         return len;
 849 }
 850
 851 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 852
 853 int inet_dccp_listen(struct socket *sock, int backlog)
 854 {
 855         struct sock *sk = sock->sk;
 856         unsigned char old_state;
 857         int err;
 858
 859         lock_sock(sk);
 860
 861         err = -EINVAL;
 862         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 863                 goto out;
 864
 865         old_state = sk->sk_state;
 866         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 867                 goto out;
 868
 869         /* Really, if the socket is already in listen state
 870          * we can only allow the backlog to be adjusted.
 871          */
 872         if (old_state != DCCP_LISTEN) {
 873                 /*
 874                  * FIXME: here it probably should be sk->sk_prot->listen_start
 875                  * see tcp_listen_start
 876                  */
 877                 err = dccp_listen_start(sk, backlog);
 878                 if (err)
 879                         goto out;
 880         }
 881         sk->sk_max_ack_backlog = backlog;
 882         err = 0;
 883
 884 out:
 885         release_sock(sk);
 886         return err;
 887 }
 888
 889 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 890
 891 static void dccp_terminate_connection(struct sock *sk)
 892 {
 893         u8 next_state = DCCP_CLOSED;
 894
 895         switch (sk->sk_state) {
 896         case DCCP_PASSIVE_CLOSE:
 897         case DCCP_PASSIVE_CLOSEREQ:
 898                 dccp_finish_passive_close(sk);
 899                 break;
 900         case DCCP_PARTOPEN:
 901                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 902                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 903                 /* fall through */
 904         case DCCP_OPEN:
 905                 dccp_send_close(sk, 1);
 906
 907                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 908                     !dccp_sk(sk)->dccps_server_timewait)
 909                         next_state = DCCP_ACTIVE_CLOSEREQ;
 910                 else
 911                         next_state = DCCP_CLOSING;
 912                 /* fall through */
 913         default:
 914                 dccp_set_state(sk, next_state);
 915         }
 916 }
 917
 918 void dccp_close(struct sock *sk, long timeout)
 919 {
 920         struct dccp_sock *dp = dccp_sk(sk);
 921         struct sk_buff *skb;
 922         u32 data_was_unread = 0;
 923         int state;
 924
 925         lock_sock(sk);
 926
 927         sk->sk_shutdown = SHUTDOWN_MASK;
 928
 929         if (sk->sk_state == DCCP_LISTEN) {
 930                 dccp_set_state(sk, DCCP_CLOSED);
 931
 932                 /* Special case. */
 933                 inet_csk_listen_stop(sk);
 934
 935                 goto adjudge_to_death;
 936         }
 937
 938         sk_stop_timer(sk, &dp->dccps_xmit_timer);
 939
 940         /*
 941          * We need to flush the recv. buffs.  We do this only on the
 942          * descriptor close, not protocol-sourced closes, because the
 943           *reader process may not have drained the data yet!
 944          */
 945         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 946                 data_was_unread += skb->len;
 947                 __kfree_skb(skb);
 948         }
 949
 950         if (data_was_unread) {
 951                 /* Unread data was tossed, send an appropriate Reset Code */
 952                 DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
 953                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 954                 dccp_set_state(sk, DCCP_CLOSED);
 955         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 956                 /* Check zero linger _after_ checking for unread data. */
 957                 sk->sk_prot->disconnect(sk, 0);
 958         } else if (sk->sk_state != DCCP_CLOSED) {
 959                 dccp_terminate_connection(sk);
 960         }
 961
 962         sk_stream_wait_close(sk, timeout);
 963
 964 adjudge_to_death:
 965         state = sk->sk_state;
 966         sock_hold(sk);
 967         sock_orphan(sk);
 968
 969         /*
 970          * It is the last release_sock in its life. It will remove backlog.
 971          */
 972         release_sock(sk);
 973         /*
 974          * Now socket is owned by kernel and we acquire BH lock
 975          * to finish close. No need to check for user refs.
 976          */
 977         local_bh_disable();
 978         bh_lock_sock(sk);
 979         WARN_ON(sock_owned_by_user(sk));
 980
 981         percpu_counter_inc(sk->sk_prot->orphan_count);
 982
 983         /* Have we already been destroyed by a softirq or backlog? */
 984         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
 985                 goto out;
 986
 987         if (sk->sk_state == DCCP_CLOSED)
 988                 inet_csk_destroy_sock(sk);
 989
 990         /* Otherwise, socket is reprieved until protocol close. */
 991
 992 out:
 993         bh_unlock_sock(sk);
 994         local_bh_enable();
 995         sock_put(sk);
 996 }
 997
 998 EXPORT_SYMBOL_GPL(dccp_close);
 999
1000 void dccp_shutdown(struct sock *sk, int how)
1001 {
1002         dccp_pr_debug("called shutdown(%x)\n", how);
1003 }
1004
1005 EXPORT_SYMBOL_GPL(dccp_shutdown);
1006
1007 static inline int dccp_mib_init(void)
1008 {
1009         return snmp_mib_init((void __percpu **)dccp_statistics,
1010                              sizeof(struct dccp_mib));
1011 }
1012
1013 static inline void dccp_mib_exit(void)
1014 {
1015         snmp_mib_free((void __percpu **)dccp_statistics);
1016 }
1017
1018 static int thash_entries;
1019 module_param(thash_entries, int, 0444);
1020 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1021
1022 #ifdef CONFIG_IP_DCCP_DEBUG
1023 int dccp_debug;
1024 module_param(dccp_debug, bool, 0644);
1025 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1026
1027 EXPORT_SYMBOL_GPL(dccp_debug);
1028 #endif
1029
1030 static int __init dccp_init(void)
1031 {
1032         unsigned long goal;
1033         int ehash_order, bhash_order, i;
1034         int rc;
1035
1036         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1037                      FIELD_SIZEOF(struct sk_buff, cb));
1038         rc = percpu_counter_init(&dccp_orphan_count, 0);
1039         if (rc)
1040                 goto out_fail;
1041         rc = -ENOBUFS;
1042         inet_hashinfo_init(&dccp_hashinfo);
1043         dccp_hashinfo.bind_bucket_cachep =
1044                 kmem_cache_create("dccp_bind_bucket",
1045                                   sizeof(struct inet_bind_bucket), 0,
1046                                   SLAB_HWCACHE_ALIGN, NULL);
1047         if (!dccp_hashinfo.bind_bucket_cachep)
1048                 goto out_free_percpu;
1049
1050         /*
1051          * Size and allocate the main established and bind bucket
1052          * hash tables.
1053          *
1054          * The methodology is similar to that of the buffer cache.
1055          */
1056         if (totalram_pages >= (128 * 1024))
1057                 goal = totalram_pages >> (21 - PAGE_SHIFT);
1058         else
1059                 goal = totalram_pages >> (23 - PAGE_SHIFT);
1060
1061         if (thash_entries)
1062                 goal = (thash_entries *
1063                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1064         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1065                 ;
1066         do {
1067                 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1068                                         sizeof(struct inet_ehash_bucket);
1069
1070                 while (hash_size & (hash_size - 1))
1071                         hash_size--;
1072                 dccp_hashinfo.ehash_mask = hash_size - 1;
1073                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1074                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1075         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1076
1077         if (!dccp_hashinfo.ehash) {
1078                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1079                 goto out_free_bind_bucket_cachep;
1080         }
1081
1082         for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1083                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1084                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1085         }
1086
1087         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1088                         goto out_free_dccp_ehash;
1089
1090         bhash_order = ehash_order;
1091
1092         do {
1093                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1094                                         sizeof(struct inet_bind_hashbucket);
1095                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1096                     bhash_order > 0)
1097                         continue;
1098                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1099                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1100         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1101
1102         if (!dccp_hashinfo.bhash) {
1103                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1104                 goto out_free_dccp_locks;
1105         }
1106
1107         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1108                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1109                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1110         }
1111
1112         rc = dccp_mib_init();
1113         if (rc)
1114                 goto out_free_dccp_bhash;
1115
1116         rc = dccp_ackvec_init();
1117         if (rc)
1118                 goto out_free_dccp_mib;
1119
1120         rc = dccp_sysctl_init();
1121         if (rc)
1122                 goto out_ackvec_exit;
1123
1124         rc = ccid_initialize_builtins();
1125         if (rc)
1126                 goto out_sysctl_exit;
1127
1128         dccp_timestamping_init();
1129
1130         return 0;
1131
1132 out_sysctl_exit:
1133         dccp_sysctl_exit();
1134 out_ackvec_exit:
1135         dccp_ackvec_exit();
1136 out_free_dccp_mib:
1137         dccp_mib_exit();
1138 out_free_dccp_bhash:
1139         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1140 out_free_dccp_locks:
1141         inet_ehash_locks_free(&dccp_hashinfo);
1142 out_free_dccp_ehash:
1143         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1144 out_free_bind_bucket_cachep:
1145         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1146 out_free_percpu:
1147         percpu_counter_destroy(&dccp_orphan_count);
1148 out_fail:
1149         dccp_hashinfo.bhash = NULL;
1150         dccp_hashinfo.ehash = NULL;
1151         dccp_hashinfo.bind_bucket_cachep = NULL;
1152         return rc;
1153 }
1154
1155 static void __exit dccp_fini(void)
1156 {
1157         ccid_cleanup_builtins();
1158         dccp_mib_exit();
1159         free_pages((unsigned long)dccp_hashinfo.bhash,
1160                    get_order(dccp_hashinfo.bhash_size *
1161                              sizeof(struct inet_bind_hashbucket)));
1162         free_pages((unsigned long)dccp_hashinfo.ehash,
1163                    get_order((dccp_hashinfo.ehash_mask + 1) *
1164                              sizeof(struct inet_ehash_bucket)));
1165         inet_ehash_locks_free(&dccp_hashinfo);
1166         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1167         dccp_ackvec_exit();
1168         dccp_sysctl_exit();
1169         percpu_counter_destroy(&dccp_orphan_count);
1170 }
1171
1172 module_init(dccp_init);
1173 module_exit(dccp_fini);
1174
1175 MODULE_LICENSE("GPL");
1176 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1177 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");