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_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 = 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         default:
 536                 err = -ENOPROTOOPT;
 537                 break;
 538         }
 539         release_sock(sk);
 540
 541         return err;
 542 }
 543
 544 int dccp_setsockopt(struct sock *sk, int level, int optname,
 545                     char __user *optval, unsigned int optlen)
 546 {
 547         if (level != SOL_DCCP)
 548                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 549                                                              optname, optval,
 550                                                              optlen);
 551         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 552 }
 553
 554 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 555
 556 #ifdef CONFIG_COMPAT
 557 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 558                            char __user *optval, unsigned int optlen)
 559 {
 560         if (level != SOL_DCCP)
 561                 return inet_csk_compat_setsockopt(sk, level, optname,
 562                                                   optval, optlen);
 563         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 564 }
 565
 566 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 567 #endif
 568
 569 static int dccp_getsockopt_service(struct sock *sk, int len,
 570                                    __be32 __user *optval,
 571                                    int __user *optlen)
 572 {
 573         const struct dccp_sock *dp = dccp_sk(sk);
 574         const struct dccp_service_list *sl;
 575         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 576
 577         lock_sock(sk);
 578         if ((sl = dp->dccps_service_list) != NULL) {
 579                 slen = sl->dccpsl_nr * sizeof(u32);
 580                 total_len += slen;
 581         }
 582
 583         err = -EINVAL;
 584         if (total_len > len)
 585                 goto out;
 586
 587         err = 0;
 588         if (put_user(total_len, optlen) ||
 589             put_user(dp->dccps_service, optval) ||
 590             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 591                 err = -EFAULT;
 592 out:
 593         release_sock(sk);
 594         return err;
 595 }
 596
 597 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 598                     char __user *optval, int __user *optlen)
 599 {
 600         struct dccp_sock *dp;
 601         int val, len;
 602
 603         if (get_user(len, optlen))
 604                 return -EFAULT;
 605
 606         if (len < (int)sizeof(int))
 607                 return -EINVAL;
 608
 609         dp = dccp_sk(sk);
 610
 611         switch (optname) {
 612         case DCCP_SOCKOPT_PACKET_SIZE:
 613                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 614                 return 0;
 615         case DCCP_SOCKOPT_SERVICE:
 616                 return dccp_getsockopt_service(sk, len,
 617                                                (__be32 __user *)optval, optlen);
 618         case DCCP_SOCKOPT_GET_CUR_MPS:
 619                 val = dp->dccps_mss_cache;
 620                 break;
 621         case DCCP_SOCKOPT_AVAILABLE_CCIDS:
 622                 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
 623         case DCCP_SOCKOPT_TX_CCID:
 624                 val = ccid_get_current_tx_ccid(dp);
 625                 if (val < 0)
 626                         return -ENOPROTOOPT;
 627                 break;
 628         case DCCP_SOCKOPT_RX_CCID:
 629                 val = ccid_get_current_rx_ccid(dp);
 630                 if (val < 0)
 631                         return -ENOPROTOOPT;
 632                 break;
 633         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 634                 val = dp->dccps_server_timewait;
 635                 break;
 636         case DCCP_SOCKOPT_SEND_CSCOV:
 637                 val = dp->dccps_pcslen;
 638                 break;
 639         case DCCP_SOCKOPT_RECV_CSCOV:
 640                 val = dp->dccps_pcrlen;
 641                 break;
 642         case 128 ... 191:
 643                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 644                                              len, (u32 __user *)optval, optlen);
 645         case 192 ... 255:
 646                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 647                                              len, (u32 __user *)optval, optlen);
 648         default:
 649                 return -ENOPROTOOPT;
 650         }
 651
 652         len = sizeof(val);
 653         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 654                 return -EFAULT;
 655
 656         return 0;
 657 }
 658
 659 int dccp_getsockopt(struct sock *sk, int level, int optname,
 660                     char __user *optval, int __user *optlen)
 661 {
 662         if (level != SOL_DCCP)
 663                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 664                                                              optname, optval,
 665                                                              optlen);
 666         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 667 }
 668
 669 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 670
 671 #ifdef CONFIG_COMPAT
 672 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 673                            char __user *optval, int __user *optlen)
 674 {
 675         if (level != SOL_DCCP)
 676                 return inet_csk_compat_getsockopt(sk, level, optname,
 677                                                   optval, optlen);
 678         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 679 }
 680
 681 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 682 #endif
 683
 684 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 685                  size_t len)
 686 {
 687         const struct dccp_sock *dp = dccp_sk(sk);
 688         const int flags = msg->msg_flags;
 689         const int noblock = flags & MSG_DONTWAIT;
 690         struct sk_buff *skb;
 691         int rc, size;
 692         long timeo;
 693
 694         if (len > dp->dccps_mss_cache)
 695                 return -EMSGSIZE;
 696
 697         lock_sock(sk);
 698
 699         if (sysctl_dccp_tx_qlen &&
 700             (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
 701                 rc = -EAGAIN;
 702                 goto out_release;
 703         }
 704
 705         timeo = sock_sndtimeo(sk, noblock);
 706
 707         /*
 708          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 709          * so that the trick in dccp_rcv_request_sent_state_process.
 710          */
 711         /* Wait for a connection to finish. */
 712         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 713                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 714                         goto out_release;
 715
 716         size = sk->sk_prot->max_header + len;
 717         release_sock(sk);
 718         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 719         lock_sock(sk);
 720         if (skb == NULL)
 721                 goto out_release;
 722
 723         skb_reserve(skb, sk->sk_prot->max_header);
 724         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 725         if (rc != 0)
 726                 goto out_discard;
 727
 728         skb_queue_tail(&sk->sk_write_queue, skb);
 729         dccp_write_xmit(sk,0);
 730 out_release:
 731         release_sock(sk);
 732         return rc ? : len;
 733 out_discard:
 734         kfree_skb(skb);
 735         goto out_release;
 736 }
 737
 738 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 739
 740 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 741                  size_t len, int nonblock, int flags, int *addr_len)
 742 {
 743         const struct dccp_hdr *dh;
 744         long timeo;
 745
 746         lock_sock(sk);
 747
 748         if (sk->sk_state == DCCP_LISTEN) {
 749                 len = -ENOTCONN;
 750                 goto out;
 751         }
 752
 753         timeo = sock_rcvtimeo(sk, nonblock);
 754
 755         do {
 756                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 757
 758                 if (skb == NULL)
 759                         goto verify_sock_status;
 760
 761                 dh = dccp_hdr(skb);
 762
 763                 switch (dh->dccph_type) {
 764                 case DCCP_PKT_DATA:
 765                 case DCCP_PKT_DATAACK:
 766                         goto found_ok_skb;
 767
 768                 case DCCP_PKT_CLOSE:
 769                 case DCCP_PKT_CLOSEREQ:
 770                         if (!(flags & MSG_PEEK))
 771                                 dccp_finish_passive_close(sk);
 772                         /* fall through */
 773                 case DCCP_PKT_RESET:
 774                         dccp_pr_debug("found fin (%s) ok!\n",
 775                                       dccp_packet_name(dh->dccph_type));
 776                         len = 0;
 777                         goto found_fin_ok;
 778                 default:
 779                         dccp_pr_debug("packet_type=%s\n",
 780                                       dccp_packet_name(dh->dccph_type));
 781                         sk_eat_skb(sk, skb, 0);
 782                 }
 783 verify_sock_status:
 784                 if (sock_flag(sk, SOCK_DONE)) {
 785                         len = 0;
 786                         break;
 787                 }
 788
 789                 if (sk->sk_err) {
 790                         len = sock_error(sk);
 791                         break;
 792                 }
 793
 794                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 795                         len = 0;
 796                         break;
 797                 }
 798
 799                 if (sk->sk_state == DCCP_CLOSED) {
 800                         if (!sock_flag(sk, SOCK_DONE)) {
 801                                 /* This occurs when user tries to read
 802                                  * from never connected socket.
 803                                  */
 804                                 len = -ENOTCONN;
 805                                 break;
 806                         }
 807                         len = 0;
 808                         break;
 809                 }
 810
 811                 if (!timeo) {
 812                         len = -EAGAIN;
 813                         break;
 814                 }
 815
 816                 if (signal_pending(current)) {
 817                         len = sock_intr_errno(timeo);
 818                         break;
 819                 }
 820
 821                 sk_wait_data(sk, &timeo);
 822                 continue;
 823         found_ok_skb:
 824                 if (len > skb->len)
 825                         len = skb->len;
 826                 else if (len < skb->len)
 827                         msg->msg_flags |= MSG_TRUNC;
 828
 829                 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 830                         /* Exception. Bailout! */
 831                         len = -EFAULT;
 832                         break;
 833                 }
 834                 if (flags & MSG_TRUNC)
 835                         len = skb->len;
 836         found_fin_ok:
 837                 if (!(flags & MSG_PEEK))
 838                         sk_eat_skb(sk, skb, 0);
 839                 break;
 840         } while (1);
 841 out:
 842         release_sock(sk);
 843         return len;
 844 }
 845
 846 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 847
 848 int inet_dccp_listen(struct socket *sock, int backlog)
 849 {
 850         struct sock *sk = sock->sk;
 851         unsigned char old_state;
 852         int err;
 853
 854         lock_sock(sk);
 855
 856         err = -EINVAL;
 857         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 858                 goto out;
 859
 860         old_state = sk->sk_state;
 861         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 862                 goto out;
 863
 864         /* Really, if the socket is already in listen state
 865          * we can only allow the backlog to be adjusted.
 866          */
 867         if (old_state != DCCP_LISTEN) {
 868                 /*
 869                  * FIXME: here it probably should be sk->sk_prot->listen_start
 870                  * see tcp_listen_start
 871                  */
 872                 err = dccp_listen_start(sk, backlog);
 873                 if (err)
 874                         goto out;
 875         }
 876         sk->sk_max_ack_backlog = backlog;
 877         err = 0;
 878
 879 out:
 880         release_sock(sk);
 881         return err;
 882 }
 883
 884 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 885
 886 static void dccp_terminate_connection(struct sock *sk)
 887 {
 888         u8 next_state = DCCP_CLOSED;
 889
 890         switch (sk->sk_state) {
 891         case DCCP_PASSIVE_CLOSE:
 892         case DCCP_PASSIVE_CLOSEREQ:
 893                 dccp_finish_passive_close(sk);
 894                 break;
 895         case DCCP_PARTOPEN:
 896                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 897                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 898                 /* fall through */
 899         case DCCP_OPEN:
 900                 dccp_send_close(sk, 1);
 901
 902                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 903                     !dccp_sk(sk)->dccps_server_timewait)
 904                         next_state = DCCP_ACTIVE_CLOSEREQ;
 905                 else
 906                         next_state = DCCP_CLOSING;
 907                 /* fall through */
 908         default:
 909                 dccp_set_state(sk, next_state);
 910         }
 911 }
 912
 913 void dccp_close(struct sock *sk, long timeout)
 914 {
 915         struct dccp_sock *dp = dccp_sk(sk);
 916         struct sk_buff *skb;
 917         u32 data_was_unread = 0;
 918         int state;
 919
 920         lock_sock(sk);
 921
 922         sk->sk_shutdown = SHUTDOWN_MASK;
 923
 924         if (sk->sk_state == DCCP_LISTEN) {
 925                 dccp_set_state(sk, DCCP_CLOSED);
 926
 927                 /* Special case. */
 928                 inet_csk_listen_stop(sk);
 929
 930                 goto adjudge_to_death;
 931         }
 932
 933         sk_stop_timer(sk, &dp->dccps_xmit_timer);
 934
 935         /*
 936          * We need to flush the recv. buffs.  We do this only on the
 937          * descriptor close, not protocol-sourced closes, because the
 938           *reader process may not have drained the data yet!
 939          */
 940         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 941                 data_was_unread += skb->len;
 942                 __kfree_skb(skb);
 943         }
 944
 945         if (data_was_unread) {
 946                 /* Unread data was tossed, send an appropriate Reset Code */
 947                 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
 948                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 949                 dccp_set_state(sk, DCCP_CLOSED);
 950         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 951                 /* Check zero linger _after_ checking for unread data. */
 952                 sk->sk_prot->disconnect(sk, 0);
 953         } else if (sk->sk_state != DCCP_CLOSED) {
 954                 dccp_terminate_connection(sk);
 955         }
 956
 957         sk_stream_wait_close(sk, timeout);
 958
 959 adjudge_to_death:
 960         state = sk->sk_state;
 961         sock_hold(sk);
 962         sock_orphan(sk);
 963
 964         /*
 965          * It is the last release_sock in its life. It will remove backlog.
 966          */
 967         release_sock(sk);
 968         /*
 969          * Now socket is owned by kernel and we acquire BH lock
 970          * to finish close. No need to check for user refs.
 971          */
 972         local_bh_disable();
 973         bh_lock_sock(sk);
 974         WARN_ON(sock_owned_by_user(sk));
 975
 976         percpu_counter_inc(sk->sk_prot->orphan_count);
 977
 978         /* Have we already been destroyed by a softirq or backlog? */
 979         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
 980                 goto out;
 981
 982         if (sk->sk_state == DCCP_CLOSED)
 983                 inet_csk_destroy_sock(sk);
 984
 985         /* Otherwise, socket is reprieved until protocol close. */
 986
 987 out:
 988         bh_unlock_sock(sk);
 989         local_bh_enable();
 990         sock_put(sk);
 991 }
 992
 993 EXPORT_SYMBOL_GPL(dccp_close);
 994
 995 void dccp_shutdown(struct sock *sk, int how)
 996 {
 997         dccp_pr_debug("called shutdown(%x)\n", how);
 998 }
 999
1000 EXPORT_SYMBOL_GPL(dccp_shutdown);
1001
1002 static inline int dccp_mib_init(void)
1003 {
1004         return snmp_mib_init((void __percpu **)dccp_statistics,
1005                              sizeof(struct dccp_mib),
1006                              __alignof__(struct dccp_mib));
1007 }
1008
1009 static inline void dccp_mib_exit(void)
1010 {
1011         snmp_mib_free((void __percpu **)dccp_statistics);
1012 }
1013
1014 static int thash_entries;
1015 module_param(thash_entries, int, 0444);
1016 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1017
1018 #ifdef CONFIG_IP_DCCP_DEBUG
1019 int dccp_debug;
1020 module_param(dccp_debug, bool, 0644);
1021 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1022
1023 EXPORT_SYMBOL_GPL(dccp_debug);
1024 #endif
1025
1026 static int __init dccp_init(void)
1027 {
1028         unsigned long goal;
1029         int ehash_order, bhash_order, i;
1030         int rc;
1031
1032         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1033                      FIELD_SIZEOF(struct sk_buff, cb));
1034         rc = percpu_counter_init(&dccp_orphan_count, 0);
1035         if (rc)
1036                 goto out_fail;
1037         rc = -ENOBUFS;
1038         inet_hashinfo_init(&dccp_hashinfo);
1039         dccp_hashinfo.bind_bucket_cachep =
1040                 kmem_cache_create("dccp_bind_bucket",
1041                                   sizeof(struct inet_bind_bucket), 0,
1042                                   SLAB_HWCACHE_ALIGN, NULL);
1043         if (!dccp_hashinfo.bind_bucket_cachep)
1044                 goto out_free_percpu;
1045
1046         /*
1047          * Size and allocate the main established and bind bucket
1048          * hash tables.
1049          *
1050          * The methodology is similar to that of the buffer cache.
1051          */
1052         if (totalram_pages >= (128 * 1024))
1053                 goal = totalram_pages >> (21 - PAGE_SHIFT);
1054         else
1055                 goal = totalram_pages >> (23 - PAGE_SHIFT);
1056
1057         if (thash_entries)
1058                 goal = (thash_entries *
1059                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1060         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1061                 ;
1062         do {
1063                 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1064                                         sizeof(struct inet_ehash_bucket);
1065
1066                 while (hash_size & (hash_size - 1))
1067                         hash_size--;
1068                 dccp_hashinfo.ehash_mask = hash_size - 1;
1069                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1070                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1071         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1072
1073         if (!dccp_hashinfo.ehash) {
1074                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1075                 goto out_free_bind_bucket_cachep;
1076         }
1077
1078         for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1079                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1080                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1081         }
1082
1083         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1084                         goto out_free_dccp_ehash;
1085
1086         bhash_order = ehash_order;
1087
1088         do {
1089                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1090                                         sizeof(struct inet_bind_hashbucket);
1091                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1092                     bhash_order > 0)
1093                         continue;
1094                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1095                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1096         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1097
1098         if (!dccp_hashinfo.bhash) {
1099                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1100                 goto out_free_dccp_locks;
1101         }
1102
1103         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1104                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1105                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1106         }
1107
1108         rc = dccp_mib_init();
1109         if (rc)
1110                 goto out_free_dccp_bhash;
1111
1112         rc = dccp_ackvec_init();
1113         if (rc)
1114                 goto out_free_dccp_mib;
1115
1116         rc = dccp_sysctl_init();
1117         if (rc)
1118                 goto out_ackvec_exit;
1119
1120         rc = ccid_initialize_builtins();
1121         if (rc)
1122                 goto out_sysctl_exit;
1123
1124         dccp_timestamping_init();
1125
1126         return 0;
1127
1128 out_sysctl_exit:
1129         dccp_sysctl_exit();
1130 out_ackvec_exit:
1131         dccp_ackvec_exit();
1132 out_free_dccp_mib:
1133         dccp_mib_exit();
1134 out_free_dccp_bhash:
1135         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1136 out_free_dccp_locks:
1137         inet_ehash_locks_free(&dccp_hashinfo);
1138 out_free_dccp_ehash:
1139         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1140 out_free_bind_bucket_cachep:
1141         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1142 out_free_percpu:
1143         percpu_counter_destroy(&dccp_orphan_count);
1144 out_fail:
1145         dccp_hashinfo.bhash = NULL;
1146         dccp_hashinfo.ehash = NULL;
1147         dccp_hashinfo.bind_bucket_cachep = NULL;
1148         return rc;
1149 }
1150
1151 static void __exit dccp_fini(void)
1152 {
1153         ccid_cleanup_builtins();
1154         dccp_mib_exit();
1155         free_pages((unsigned long)dccp_hashinfo.bhash,
1156                    get_order(dccp_hashinfo.bhash_size *
1157                              sizeof(struct inet_bind_hashbucket)));
1158         free_pages((unsigned long)dccp_hashinfo.ehash,
1159                    get_order((dccp_hashinfo.ehash_mask + 1) *
1160                              sizeof(struct inet_ehash_bucket)));
1161         inet_ehash_locks_free(&dccp_hashinfo);
1162         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1163         dccp_ackvec_exit();
1164         dccp_sysctl_exit();
1165         percpu_counter_destroy(&dccp_orphan_count);
1166 }
1167
1168 module_init(dccp_init);
1169 module_exit(dccp_fini);
1170
1171 MODULE_LICENSE("GPL");
1172 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1173 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");