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 #ifdef CONFIG_IP_DCCP_DEBUG
  54 static const char *dccp_state_name(const int state)
  55 {
  56         static const char *const dccp_state_names[] = {
  57         [DCCP_OPEN]             = "OPEN",
  58         [DCCP_REQUESTING]       = "REQUESTING",
  59         [DCCP_PARTOPEN]         = "PARTOPEN",
  60         [DCCP_LISTEN]           = "LISTEN",
  61         [DCCP_RESPOND]          = "RESPOND",
  62         [DCCP_CLOSING]          = "CLOSING",
  63         [DCCP_ACTIVE_CLOSEREQ]  = "CLOSEREQ",
  64         [DCCP_PASSIVE_CLOSE]    = "PASSIVE_CLOSE",
  65         [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
  66         [DCCP_TIME_WAIT]        = "TIME_WAIT",
  67         [DCCP_CLOSED]           = "CLOSED",
  68         };
  69
  70         if (state >= DCCP_MAX_STATES)
  71                 return "INVALID STATE!";
  72         else
  73                 return dccp_state_names[state];
  74 }
  75 #endif
  76
  77 void dccp_set_state(struct sock *sk, const int state)
  78 {
  79         const int oldstate = sk->sk_state;
  80
  81         dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
  82                       dccp_state_name(oldstate), dccp_state_name(state));
  83         WARN_ON(state == oldstate);
  84
  85         switch (state) {
  86         case DCCP_OPEN:
  87                 if (oldstate != DCCP_OPEN)
  88                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  89                 /* Client retransmits all Confirm options until entering OPEN */
  90                 if (oldstate == DCCP_PARTOPEN)
  91                         dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
  92                 break;
  93
  94         case DCCP_CLOSED:
  95                 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
  96                     oldstate == DCCP_CLOSING)
  97                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  98
  99                 sk->sk_prot->unhash(sk);
 100                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
 101                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 102                         inet_put_port(sk);
 103                 /* fall through */
 104         default:
 105                 if (oldstate == DCCP_OPEN)
 106                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
 107         }
 108
 109         /* Change state AFTER socket is unhashed to avoid closed
 110          * socket sitting in hash tables.
 111          */
 112         sk->sk_state = state;
 113 }
 114
 115 EXPORT_SYMBOL_GPL(dccp_set_state);
 116
 117 static void dccp_finish_passive_close(struct sock *sk)
 118 {
 119         switch (sk->sk_state) {
 120         case DCCP_PASSIVE_CLOSE:
 121                 /* Node (client or server) has received Close packet. */
 122                 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
 123                 dccp_set_state(sk, DCCP_CLOSED);
 124                 break;
 125         case DCCP_PASSIVE_CLOSEREQ:
 126                 /*
 127                  * Client received CloseReq. We set the `active' flag so that
 128                  * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
 129                  */
 130                 dccp_send_close(sk, 1);
 131                 dccp_set_state(sk, DCCP_CLOSING);
 132         }
 133 }
 134
 135 void dccp_done(struct sock *sk)
 136 {
 137         dccp_set_state(sk, DCCP_CLOSED);
 138         dccp_clear_xmit_timers(sk);
 139
 140         sk->sk_shutdown = SHUTDOWN_MASK;
 141
 142         if (!sock_flag(sk, SOCK_DEAD))
 143                 sk->sk_state_change(sk);
 144         else
 145                 inet_csk_destroy_sock(sk);
 146 }
 147
 148 EXPORT_SYMBOL_GPL(dccp_done);
 149
 150 const char *dccp_packet_name(const int type)
 151 {
 152         static const char *const dccp_packet_names[] = {
 153                 [DCCP_PKT_REQUEST]  = "REQUEST",
 154                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 155                 [DCCP_PKT_DATA]     = "DATA",
 156                 [DCCP_PKT_ACK]      = "ACK",
 157                 [DCCP_PKT_DATAACK]  = "DATAACK",
 158                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 159                 [DCCP_PKT_CLOSE]    = "CLOSE",
 160                 [DCCP_PKT_RESET]    = "RESET",
 161                 [DCCP_PKT_SYNC]     = "SYNC",
 162                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 163         };
 164
 165         if (type >= DCCP_NR_PKT_TYPES)
 166                 return "INVALID";
 167         else
 168                 return dccp_packet_names[type];
 169 }
 170
 171 EXPORT_SYMBOL_GPL(dccp_packet_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_tx_qlen       = sysctl_dccp_tx_qlen;
 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_is_writeable(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_is_writeable(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 = memdup_user(optval, optlen);
 477         if (IS_ERR(val))
 478                 return PTR_ERR(val);
 479
 480         lock_sock(sk);
 481         if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
 482                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
 483
 484         if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
 485                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
 486         release_sock(sk);
 487
 488         kfree(val);
 489         return rc;
 490 }
 491
 492 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 493                 char __user *optval, unsigned int optlen)
 494 {
 495         struct dccp_sock *dp = dccp_sk(sk);
 496         int val, err = 0;
 497
 498         switch (optname) {
 499         case DCCP_SOCKOPT_PACKET_SIZE:
 500                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 501                 return 0;
 502         case DCCP_SOCKOPT_CHANGE_L:
 503         case DCCP_SOCKOPT_CHANGE_R:
 504                 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
 505                 return 0;
 506         case DCCP_SOCKOPT_CCID:
 507         case DCCP_SOCKOPT_RX_CCID:
 508         case DCCP_SOCKOPT_TX_CCID:
 509                 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
 510         }
 511
 512         if (optlen < (int)sizeof(int))
 513                 return -EINVAL;
 514
 515         if (get_user(val, (int __user *)optval))
 516                 return -EFAULT;
 517
 518         if (optname == DCCP_SOCKOPT_SERVICE)
 519                 return dccp_setsockopt_service(sk, val, optval, optlen);
 520
 521         lock_sock(sk);
 522         switch (optname) {
 523         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 524                 if (dp->dccps_role != DCCP_ROLE_SERVER)
 525                         err = -EOPNOTSUPP;
 526                 else
 527                         dp->dccps_server_timewait = (val != 0);
 528                 break;
 529         case DCCP_SOCKOPT_SEND_CSCOV:
 530                 err = dccp_setsockopt_cscov(sk, val, false);
 531                 break;
 532         case DCCP_SOCKOPT_RECV_CSCOV:
 533                 err = dccp_setsockopt_cscov(sk, val, true);
 534                 break;
 535         case DCCP_SOCKOPT_QPOLICY_ID:
 536                 if (sk->sk_state != DCCP_CLOSED)
 537                         err = -EISCONN;
 538                 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
 539                         err = -EINVAL;
 540                 else
 541                         dp->dccps_qpolicy = val;
 542                 break;
 543         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
 544                 if (val < 0)
 545                         err = -EINVAL;
 546                 else
 547                         dp->dccps_tx_qlen = val;
 548                 break;
 549         default:
 550                 err = -ENOPROTOOPT;
 551                 break;
 552         }
 553         release_sock(sk);
 554
 555         return err;
 556 }
 557
 558 int dccp_setsockopt(struct sock *sk, int level, int optname,
 559                     char __user *optval, unsigned int optlen)
 560 {
 561         if (level != SOL_DCCP)
 562                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 563                                                              optname, optval,
 564                                                              optlen);
 565         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 566 }
 567
 568 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 569
 570 #ifdef CONFIG_COMPAT
 571 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 572                            char __user *optval, unsigned int optlen)
 573 {
 574         if (level != SOL_DCCP)
 575                 return inet_csk_compat_setsockopt(sk, level, optname,
 576                                                   optval, optlen);
 577         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 578 }
 579
 580 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 581 #endif
 582
 583 static int dccp_getsockopt_service(struct sock *sk, int len,
 584                                    __be32 __user *optval,
 585                                    int __user *optlen)
 586 {
 587         const struct dccp_sock *dp = dccp_sk(sk);
 588         const struct dccp_service_list *sl;
 589         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 590
 591         lock_sock(sk);
 592         if ((sl = dp->dccps_service_list) != NULL) {
 593                 slen = sl->dccpsl_nr * sizeof(u32);
 594                 total_len += slen;
 595         }
 596
 597         err = -EINVAL;
 598         if (total_len > len)
 599                 goto out;
 600
 601         err = 0;
 602         if (put_user(total_len, optlen) ||
 603             put_user(dp->dccps_service, optval) ||
 604             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 605                 err = -EFAULT;
 606 out:
 607         release_sock(sk);
 608         return err;
 609 }
 610
 611 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 612                     char __user *optval, int __user *optlen)
 613 {
 614         struct dccp_sock *dp;
 615         int val, len;
 616
 617         if (get_user(len, optlen))
 618                 return -EFAULT;
 619
 620         if (len < (int)sizeof(int))
 621                 return -EINVAL;
 622
 623         dp = dccp_sk(sk);
 624
 625         switch (optname) {
 626         case DCCP_SOCKOPT_PACKET_SIZE:
 627                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 628                 return 0;
 629         case DCCP_SOCKOPT_SERVICE:
 630                 return dccp_getsockopt_service(sk, len,
 631                                                (__be32 __user *)optval, optlen);
 632         case DCCP_SOCKOPT_GET_CUR_MPS:
 633                 val = dp->dccps_mss_cache;
 634                 break;
 635         case DCCP_SOCKOPT_AVAILABLE_CCIDS:
 636                 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
 637         case DCCP_SOCKOPT_TX_CCID:
 638                 val = ccid_get_current_tx_ccid(dp);
 639                 if (val < 0)
 640                         return -ENOPROTOOPT;
 641                 break;
 642         case DCCP_SOCKOPT_RX_CCID:
 643                 val = ccid_get_current_rx_ccid(dp);
 644                 if (val < 0)
 645                         return -ENOPROTOOPT;
 646                 break;
 647         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 648                 val = dp->dccps_server_timewait;
 649                 break;
 650         case DCCP_SOCKOPT_SEND_CSCOV:
 651                 val = dp->dccps_pcslen;
 652                 break;
 653         case DCCP_SOCKOPT_RECV_CSCOV:
 654                 val = dp->dccps_pcrlen;
 655                 break;
 656         case DCCP_SOCKOPT_QPOLICY_ID:
 657                 val = dp->dccps_qpolicy;
 658                 break;
 659         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
 660                 val = dp->dccps_tx_qlen;
 661                 break;
 662         case 128 ... 191:
 663                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 664                                              len, (u32 __user *)optval, optlen);
 665         case 192 ... 255:
 666                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 667                                              len, (u32 __user *)optval, optlen);
 668         default:
 669                 return -ENOPROTOOPT;
 670         }
 671
 672         len = sizeof(val);
 673         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 674                 return -EFAULT;
 675
 676         return 0;
 677 }
 678
 679 int dccp_getsockopt(struct sock *sk, int level, int optname,
 680                     char __user *optval, int __user *optlen)
 681 {
 682         if (level != SOL_DCCP)
 683                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 684                                                              optname, optval,
 685                                                              optlen);
 686         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 687 }
 688
 689 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 690
 691 #ifdef CONFIG_COMPAT
 692 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 693                            char __user *optval, int __user *optlen)
 694 {
 695         if (level != SOL_DCCP)
 696                 return inet_csk_compat_getsockopt(sk, level, optname,
 697                                                   optval, optlen);
 698         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 699 }
 700
 701 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 702 #endif
 703
 704 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
 705 {
 706         struct cmsghdr *cmsg;
 707
 708         /*
 709          * Assign an (opaque) qpolicy priority value to skb->priority.
 710          *
 711          * We are overloading this skb field for use with the qpolicy subystem.
 712          * The skb->priority is normally used for the SO_PRIORITY option, which
 713          * is initialised from sk_priority. Since the assignment of sk_priority
 714          * to skb->priority happens later (on layer 3), we overload this field
 715          * for use with queueing priorities as long as the skb is on layer 4.
 716          * The default priority value (if nothing is set) is 0.
 717          */
 718         skb->priority = 0;
 719
 720         for_each_cmsghdr(cmsg, msg) {
 721                 if (!CMSG_OK(msg, cmsg))
 722                         return -EINVAL;
 723
 724                 if (cmsg->cmsg_level != SOL_DCCP)
 725                         continue;
 726
 727                 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
 728                     !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
 729                         return -EINVAL;
 730
 731                 switch (cmsg->cmsg_type) {
 732                 case DCCP_SCM_PRIORITY:
 733                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
 734                                 return -EINVAL;
 735                         skb->priority = *(__u32 *)CMSG_DATA(cmsg);
 736                         break;
 737                 default:
 738                         return -EINVAL;
 739                 }
 740         }
 741         return 0;
 742 }
 743
 744 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 745 {
 746         const struct dccp_sock *dp = dccp_sk(sk);
 747         const int flags = msg->msg_flags;
 748         const int noblock = flags & MSG_DONTWAIT;
 749         struct sk_buff *skb;
 750         int rc, size;
 751         long timeo;
 752
 753         if (len > dp->dccps_mss_cache)
 754                 return -EMSGSIZE;
 755
 756         lock_sock(sk);
 757
 758         if (dccp_qpolicy_full(sk)) {
 759                 rc = -EAGAIN;
 760                 goto out_release;
 761         }
 762
 763         timeo = sock_sndtimeo(sk, noblock);
 764
 765         /*
 766          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 767          * so that the trick in dccp_rcv_request_sent_state_process.
 768          */
 769         /* Wait for a connection to finish. */
 770         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 771                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 772                         goto out_release;
 773
 774         size = sk->sk_prot->max_header + len;
 775         release_sock(sk);
 776         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 777         lock_sock(sk);
 778         if (skb == NULL)
 779                 goto out_release;
 780
 781         skb_reserve(skb, sk->sk_prot->max_header);
 782         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 783         if (rc != 0)
 784                 goto out_discard;
 785
 786         rc = dccp_msghdr_parse(msg, skb);
 787         if (rc != 0)
 788                 goto out_discard;
 789
 790         dccp_qpolicy_push(sk, skb);
 791         /*
 792          * The xmit_timer is set if the TX CCID is rate-based and will expire
 793          * when congestion control permits to release further packets into the
 794          * network. Window-based CCIDs do not use this timer.
 795          */
 796         if (!timer_pending(&dp->dccps_xmit_timer))
 797                 dccp_write_xmit(sk);
 798 out_release:
 799         release_sock(sk);
 800         return rc ? : len;
 801 out_discard:
 802         kfree_skb(skb);
 803         goto out_release;
 804 }
 805
 806 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 807
 808 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 809                  int flags, int *addr_len)
 810 {
 811         const struct dccp_hdr *dh;
 812         long timeo;
 813
 814         lock_sock(sk);
 815
 816         if (sk->sk_state == DCCP_LISTEN) {
 817                 len = -ENOTCONN;
 818                 goto out;
 819         }
 820
 821         timeo = sock_rcvtimeo(sk, nonblock);
 822
 823         do {
 824                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 825
 826                 if (skb == NULL)
 827                         goto verify_sock_status;
 828
 829                 dh = dccp_hdr(skb);
 830
 831                 switch (dh->dccph_type) {
 832                 case DCCP_PKT_DATA:
 833                 case DCCP_PKT_DATAACK:
 834                         goto found_ok_skb;
 835
 836                 case DCCP_PKT_CLOSE:
 837                 case DCCP_PKT_CLOSEREQ:
 838                         if (!(flags & MSG_PEEK))
 839                                 dccp_finish_passive_close(sk);
 840                         /* fall through */
 841                 case DCCP_PKT_RESET:
 842                         dccp_pr_debug("found fin (%s) ok!\n",
 843                                       dccp_packet_name(dh->dccph_type));
 844                         len = 0;
 845                         goto found_fin_ok;
 846                 default:
 847                         dccp_pr_debug("packet_type=%s\n",
 848                                       dccp_packet_name(dh->dccph_type));
 849                         sk_eat_skb(sk, skb);
 850                 }
 851 verify_sock_status:
 852                 if (sock_flag(sk, SOCK_DONE)) {
 853                         len = 0;
 854                         break;
 855                 }
 856
 857                 if (sk->sk_err) {
 858                         len = sock_error(sk);
 859                         break;
 860                 }
 861
 862                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 863                         len = 0;
 864                         break;
 865                 }
 866
 867                 if (sk->sk_state == DCCP_CLOSED) {
 868                         if (!sock_flag(sk, SOCK_DONE)) {
 869                                 /* This occurs when user tries to read
 870                                  * from never connected socket.
 871                                  */
 872                                 len = -ENOTCONN;
 873                                 break;
 874                         }
 875                         len = 0;
 876                         break;
 877                 }
 878
 879                 if (!timeo) {
 880                         len = -EAGAIN;
 881                         break;
 882                 }
 883
 884                 if (signal_pending(current)) {
 885                         len = sock_intr_errno(timeo);
 886                         break;
 887                 }
 888
 889                 sk_wait_data(sk, &timeo);
 890                 continue;
 891         found_ok_skb:
 892                 if (len > skb->len)
 893                         len = skb->len;
 894                 else if (len < skb->len)
 895                         msg->msg_flags |= MSG_TRUNC;
 896
 897                 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
 898                         /* Exception. Bailout! */
 899                         len = -EFAULT;
 900                         break;
 901                 }
 902                 if (flags & MSG_TRUNC)
 903                         len = skb->len;
 904         found_fin_ok:
 905                 if (!(flags & MSG_PEEK))
 906                         sk_eat_skb(sk, skb);
 907                 break;
 908         } while (1);
 909 out:
 910         release_sock(sk);
 911         return len;
 912 }
 913
 914 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 915
 916 int inet_dccp_listen(struct socket *sock, int backlog)
 917 {
 918         struct sock *sk = sock->sk;
 919         unsigned char old_state;
 920         int err;
 921
 922         lock_sock(sk);
 923
 924         err = -EINVAL;
 925         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 926                 goto out;
 927
 928         old_state = sk->sk_state;
 929         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 930                 goto out;
 931
 932         /* Really, if the socket is already in listen state
 933          * we can only allow the backlog to be adjusted.
 934          */
 935         if (old_state != DCCP_LISTEN) {
 936                 /*
 937                  * FIXME: here it probably should be sk->sk_prot->listen_start
 938                  * see tcp_listen_start
 939                  */
 940                 err = dccp_listen_start(sk, backlog);
 941                 if (err)
 942                         goto out;
 943         }
 944         sk->sk_max_ack_backlog = backlog;
 945         err = 0;
 946
 947 out:
 948         release_sock(sk);
 949         return err;
 950 }
 951
 952 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 953
 954 static void dccp_terminate_connection(struct sock *sk)
 955 {
 956         u8 next_state = DCCP_CLOSED;
 957
 958         switch (sk->sk_state) {
 959         case DCCP_PASSIVE_CLOSE:
 960         case DCCP_PASSIVE_CLOSEREQ:
 961                 dccp_finish_passive_close(sk);
 962                 break;
 963         case DCCP_PARTOPEN:
 964                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 965                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 966                 /* fall through */
 967         case DCCP_OPEN:
 968                 dccp_send_close(sk, 1);
 969
 970                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 971                     !dccp_sk(sk)->dccps_server_timewait)
 972                         next_state = DCCP_ACTIVE_CLOSEREQ;
 973                 else
 974                         next_state = DCCP_CLOSING;
 975                 /* fall through */
 976         default:
 977                 dccp_set_state(sk, next_state);
 978         }
 979 }
 980
 981 void dccp_close(struct sock *sk, long timeout)
 982 {
 983         struct dccp_sock *dp = dccp_sk(sk);
 984         struct sk_buff *skb;
 985         u32 data_was_unread = 0;
 986         int state;
 987
 988         lock_sock(sk);
 989
 990         sk->sk_shutdown = SHUTDOWN_MASK;
 991
 992         if (sk->sk_state == DCCP_LISTEN) {
 993                 dccp_set_state(sk, DCCP_CLOSED);
 994
 995                 /* Special case. */
 996                 inet_csk_listen_stop(sk);
 997
 998                 goto adjudge_to_death;
 999         }
1000
1001         sk_stop_timer(sk, &dp->dccps_xmit_timer);
1002
1003         /*
1004          * We need to flush the recv. buffs.  We do this only on the
1005          * descriptor close, not protocol-sourced closes, because the
1006           *reader process may not have drained the data yet!
1007          */
1008         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1009                 data_was_unread += skb->len;
1010                 __kfree_skb(skb);
1011         }
1012
1013         if (data_was_unread) {
1014                 /* Unread data was tossed, send an appropriate Reset Code */
1015                 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1016                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1017                 dccp_set_state(sk, DCCP_CLOSED);
1018         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1019                 /* Check zero linger _after_ checking for unread data. */
1020                 sk->sk_prot->disconnect(sk, 0);
1021         } else if (sk->sk_state != DCCP_CLOSED) {
1022                 /*
1023                  * Normal connection termination. May need to wait if there are
1024                  * still packets in the TX queue that are delayed by the CCID.
1025                  */
1026                 dccp_flush_write_queue(sk, &timeout);
1027                 dccp_terminate_connection(sk);
1028         }
1029
1030         /*
1031          * Flush write queue. This may be necessary in several cases:
1032          * - we have been closed by the peer but still have application data;
1033          * - abortive termination (unread data or zero linger time),
1034          * - normal termination but queue could not be flushed within time limit
1035          */
1036         __skb_queue_purge(&sk->sk_write_queue);
1037
1038         sk_stream_wait_close(sk, timeout);
1039
1040 adjudge_to_death:
1041         state = sk->sk_state;
1042         sock_hold(sk);
1043         sock_orphan(sk);
1044
1045         /*
1046          * It is the last release_sock in its life. It will remove backlog.
1047          */
1048         release_sock(sk);
1049         /*
1050          * Now socket is owned by kernel and we acquire BH lock
1051          * to finish close. No need to check for user refs.
1052          */
1053         local_bh_disable();
1054         bh_lock_sock(sk);
1055         WARN_ON(sock_owned_by_user(sk));
1056
1057         percpu_counter_inc(sk->sk_prot->orphan_count);
1058
1059         /* Have we already been destroyed by a softirq or backlog? */
1060         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1061                 goto out;
1062
1063         if (sk->sk_state == DCCP_CLOSED)
1064                 inet_csk_destroy_sock(sk);
1065
1066         /* Otherwise, socket is reprieved until protocol close. */
1067
1068 out:
1069         bh_unlock_sock(sk);
1070         local_bh_enable();
1071         sock_put(sk);
1072 }
1073
1074 EXPORT_SYMBOL_GPL(dccp_close);
1075
1076 void dccp_shutdown(struct sock *sk, int how)
1077 {
1078         dccp_pr_debug("called shutdown(%x)\n", how);
1079 }
1080
1081 EXPORT_SYMBOL_GPL(dccp_shutdown);
1082
1083 static inline int __init dccp_mib_init(void)
1084 {
1085         dccp_statistics = alloc_percpu(struct dccp_mib);
1086         if (!dccp_statistics)
1087                 return -ENOMEM;
1088         return 0;
1089 }
1090
1091 static inline void dccp_mib_exit(void)
1092 {
1093         free_percpu(dccp_statistics);
1094 }
1095
1096 static int thash_entries;
1097 module_param(thash_entries, int, 0444);
1098 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1099
1100 #ifdef CONFIG_IP_DCCP_DEBUG
1101 bool dccp_debug;
1102 module_param(dccp_debug, bool, 0644);
1103 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1104
1105 EXPORT_SYMBOL_GPL(dccp_debug);
1106 #endif
1107
1108 static int __init dccp_init(void)
1109 {
1110         unsigned long goal;
1111         int ehash_order, bhash_order, i;
1112         int rc;
1113
1114         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1115                      FIELD_SIZEOF(struct sk_buff, cb));
1116         rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1117         if (rc)
1118                 goto out_fail;
1119         rc = -ENOBUFS;
1120         inet_hashinfo_init(&dccp_hashinfo);
1121         dccp_hashinfo.bind_bucket_cachep =
1122                 kmem_cache_create("dccp_bind_bucket",
1123                                   sizeof(struct inet_bind_bucket), 0,
1124                                   SLAB_HWCACHE_ALIGN, NULL);
1125         if (!dccp_hashinfo.bind_bucket_cachep)
1126                 goto out_free_percpu;
1127
1128         /*
1129          * Size and allocate the main established and bind bucket
1130          * hash tables.
1131          *
1132          * The methodology is similar to that of the buffer cache.
1133          */
1134         if (totalram_pages >= (128 * 1024))
1135                 goal = totalram_pages >> (21 - PAGE_SHIFT);
1136         else
1137                 goal = totalram_pages >> (23 - PAGE_SHIFT);
1138
1139         if (thash_entries)
1140                 goal = (thash_entries *
1141                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1142         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1143                 ;
1144         do {
1145                 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1146                                         sizeof(struct inet_ehash_bucket);
1147
1148                 while (hash_size & (hash_size - 1))
1149                         hash_size--;
1150                 dccp_hashinfo.ehash_mask = hash_size - 1;
1151                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1152                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1153         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1154
1155         if (!dccp_hashinfo.ehash) {
1156                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1157                 goto out_free_bind_bucket_cachep;
1158         }
1159
1160         for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1161                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1162
1163         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1164                         goto out_free_dccp_ehash;
1165
1166         bhash_order = ehash_order;
1167
1168         do {
1169                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1170                                         sizeof(struct inet_bind_hashbucket);
1171                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1172                     bhash_order > 0)
1173                         continue;
1174                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1175                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1176         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1177
1178         if (!dccp_hashinfo.bhash) {
1179                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1180                 goto out_free_dccp_locks;
1181         }
1182
1183         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1184                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1185                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1186         }
1187
1188         rc = dccp_mib_init();
1189         if (rc)
1190                 goto out_free_dccp_bhash;
1191
1192         rc = dccp_ackvec_init();
1193         if (rc)
1194                 goto out_free_dccp_mib;
1195
1196         rc = dccp_sysctl_init();
1197         if (rc)
1198                 goto out_ackvec_exit;
1199
1200         rc = ccid_initialize_builtins();
1201         if (rc)
1202                 goto out_sysctl_exit;
1203
1204         dccp_timestamping_init();
1205
1206         return 0;
1207
1208 out_sysctl_exit:
1209         dccp_sysctl_exit();
1210 out_ackvec_exit:
1211         dccp_ackvec_exit();
1212 out_free_dccp_mib:
1213         dccp_mib_exit();
1214 out_free_dccp_bhash:
1215         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1216 out_free_dccp_locks:
1217         inet_ehash_locks_free(&dccp_hashinfo);
1218 out_free_dccp_ehash:
1219         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1220 out_free_bind_bucket_cachep:
1221         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1222 out_free_percpu:
1223         percpu_counter_destroy(&dccp_orphan_count);
1224 out_fail:
1225         dccp_hashinfo.bhash = NULL;
1226         dccp_hashinfo.ehash = NULL;
1227         dccp_hashinfo.bind_bucket_cachep = NULL;
1228         return rc;
1229 }
1230
1231 static void __exit dccp_fini(void)
1232 {
1233         ccid_cleanup_builtins();
1234         dccp_mib_exit();
1235         free_pages((unsigned long)dccp_hashinfo.bhash,
1236                    get_order(dccp_hashinfo.bhash_size *
1237                              sizeof(struct inet_bind_hashbucket)));
1238         free_pages((unsigned long)dccp_hashinfo.ehash,
1239                    get_order((dccp_hashinfo.ehash_mask + 1) *
1240                              sizeof(struct inet_ehash_bucket)));
1241         inet_ehash_locks_free(&dccp_hashinfo);
1242         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1243         dccp_ackvec_exit();
1244         dccp_sysctl_exit();
1245         percpu_counter_destroy(&dccp_orphan_count);
1246 }
1247
1248 module_init(dccp_init);
1249 module_exit(dccp_fini);
1250
1251 MODULE_LICENSE("GPL");
1252 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1253 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");