net/dccp/proto.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  net/dccp/proto.c
   4  *
   5  *  An implementation of the DCCP protocol
   6  *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   7  */
   8
   9 #include <linux/dccp.h>
  10 #include <linux/module.h>
  11 #include <linux/types.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/in.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/init.h>
  19 #include <linux/random.h>
  20 #include <linux/slab.h>
  21 #include <net/checksum.h>
  22
  23 #include <net/inet_sock.h>
  24 #include <net/inet_common.h>
  25 #include <net/sock.h>
  26 #include <net/xfrm.h>
  27
  28 #include <asm/ioctls.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/timer.h>
  31 #include <linux/delay.h>
  32 #include <linux/poll.h>
  33
  34 #include "ccid.h"
  35 #include "dccp.h"
  36 #include "feat.h"
  37
  38 #define CREATE_TRACE_POINTS
  39 #include "trace.h"
  40
  41 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
  42
  43 EXPORT_SYMBOL_GPL(dccp_statistics);
  44
  45 DEFINE_PER_CPU(unsigned int, dccp_orphan_count);
  46 EXPORT_PER_CPU_SYMBOL_GPL(dccp_orphan_count);
  47
  48 struct inet_hashinfo dccp_hashinfo;
  49 EXPORT_SYMBOL_GPL(dccp_hashinfo);
  50
  51 /* the maximum queue length for tx in packets. 0 is no limit */
  52 int sysctl_dccp_tx_qlen __read_mostly = 5;
  53
  54 #ifdef CONFIG_IP_DCCP_DEBUG
  55 static const char *dccp_state_name(const int state)
  56 {
  57         static const char *const dccp_state_names[] = {
  58         [DCCP_OPEN]             = "OPEN",
  59         [DCCP_REQUESTING]       = "REQUESTING",
  60         [DCCP_PARTOPEN]         = "PARTOPEN",
  61         [DCCP_LISTEN]           = "LISTEN",
  62         [DCCP_RESPOND]          = "RESPOND",
  63         [DCCP_CLOSING]          = "CLOSING",
  64         [DCCP_ACTIVE_CLOSEREQ]  = "CLOSEREQ",
  65         [DCCP_PASSIVE_CLOSE]    = "PASSIVE_CLOSE",
  66         [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
  67         [DCCP_TIME_WAIT]        = "TIME_WAIT",
  68         [DCCP_CLOSED]           = "CLOSED",
  69         };
  70
  71         if (state >= DCCP_MAX_STATES)
  72                 return "INVALID STATE!";
  73         else
  74                 return dccp_state_names[state];
  75 }
  76 #endif
  77
  78 void dccp_set_state(struct sock *sk, const int state)
  79 {
  80         const int oldstate = sk->sk_state;
  81
  82         dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
  83                       dccp_state_name(oldstate), dccp_state_name(state));
  84         WARN_ON(state == oldstate);
  85
  86         switch (state) {
  87         case DCCP_OPEN:
  88                 if (oldstate != DCCP_OPEN)
  89                         DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  90                 /* Client retransmits all Confirm options until entering OPEN */
  91                 if (oldstate == DCCP_PARTOPEN)
  92                         dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
  93                 break;
  94
  95         case DCCP_CLOSED:
  96                 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
  97                     oldstate == DCCP_CLOSING)
  98                         DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  99
 100                 sk->sk_prot->unhash(sk);
 101                 if (inet_csk(sk)->icsk_bind_hash != NULL &&
 102                     !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
 103                         inet_put_port(sk);
 104                 fallthrough;
 105         default:
 106                 if (oldstate == DCCP_OPEN)
 107                         DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
 108         }
 109
 110         /* Change state AFTER socket is unhashed to avoid closed
 111          * socket sitting in hash tables.
 112          */
 113         inet_sk_set_state(sk, state);
 114 }
 115
 116 EXPORT_SYMBOL_GPL(dccp_set_state);
 117
 118 static void dccp_finish_passive_close(struct sock *sk)
 119 {
 120         switch (sk->sk_state) {
 121         case DCCP_PASSIVE_CLOSE:
 122                 /* Node (client or server) has received Close packet. */
 123                 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
 124                 dccp_set_state(sk, DCCP_CLOSED);
 125                 break;
 126         case DCCP_PASSIVE_CLOSEREQ:
 127                 /*
 128                  * Client received CloseReq. We set the `active' flag so that
 129                  * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
 130                  */
 131                 dccp_send_close(sk, 1);
 132                 dccp_set_state(sk, DCCP_CLOSING);
 133         }
 134 }
 135
 136 void dccp_done(struct sock *sk)
 137 {
 138         dccp_set_state(sk, DCCP_CLOSED);
 139         dccp_clear_xmit_timers(sk);
 140
 141         sk->sk_shutdown = SHUTDOWN_MASK;
 142
 143         if (!sock_flag(sk, SOCK_DEAD))
 144                 sk->sk_state_change(sk);
 145         else
 146                 inet_csk_destroy_sock(sk);
 147 }
 148
 149 EXPORT_SYMBOL_GPL(dccp_done);
 150
 151 const char *dccp_packet_name(const int type)
 152 {
 153         static const char *const dccp_packet_names[] = {
 154                 [DCCP_PKT_REQUEST]  = "REQUEST",
 155                 [DCCP_PKT_RESPONSE] = "RESPONSE",
 156                 [DCCP_PKT_DATA]     = "DATA",
 157                 [DCCP_PKT_ACK]      = "ACK",
 158                 [DCCP_PKT_DATAACK]  = "DATAACK",
 159                 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 160                 [DCCP_PKT_CLOSE]    = "CLOSE",
 161                 [DCCP_PKT_RESET]    = "RESET",
 162                 [DCCP_PKT_SYNC]     = "SYNC",
 163                 [DCCP_PKT_SYNCACK]  = "SYNCACK",
 164         };
 165
 166         if (type >= DCCP_NR_PKT_TYPES)
 167                 return "INVALID";
 168         else
 169                 return dccp_packet_names[type];
 170 }
 171
 172 EXPORT_SYMBOL_GPL(dccp_packet_name);
 173
 174 void dccp_destruct_common(struct sock *sk)
 175 {
 176         struct dccp_sock *dp = dccp_sk(sk);
 177
 178         ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 179         dp->dccps_hc_tx_ccid = NULL;
 180 }
 181 EXPORT_SYMBOL_GPL(dccp_destruct_common);
 182
 183 static void dccp_sk_destruct(struct sock *sk)
 184 {
 185         dccp_destruct_common(sk);
 186         inet_sock_destruct(sk);
 187 }
 188
 189 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 190 {
 191         struct dccp_sock *dp = dccp_sk(sk);
 192         struct inet_connection_sock *icsk = inet_csk(sk);
 193
 194         icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 195         icsk->icsk_syn_retries  = sysctl_dccp_request_retries;
 196         sk->sk_state            = DCCP_CLOSED;
 197         sk->sk_write_space      = dccp_write_space;
 198         sk->sk_destruct         = dccp_sk_destruct;
 199         icsk->icsk_sync_mss     = dccp_sync_mss;
 200         dp->dccps_mss_cache     = 536;
 201         dp->dccps_rate_last     = jiffies;
 202         dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 203         dp->dccps_service       = DCCP_SERVICE_CODE_IS_ABSENT;
 204         dp->dccps_tx_qlen       = sysctl_dccp_tx_qlen;
 205
 206         dccp_init_xmit_timers(sk);
 207
 208         INIT_LIST_HEAD(&dp->dccps_featneg);
 209         /* control socket doesn't need feat nego */
 210         if (likely(ctl_sock_initialized))
 211                 return dccp_feat_init(sk);
 212         return 0;
 213 }
 214
 215 EXPORT_SYMBOL_GPL(dccp_init_sock);
 216
 217 void dccp_destroy_sock(struct sock *sk)
 218 {
 219         struct dccp_sock *dp = dccp_sk(sk);
 220
 221         __skb_queue_purge(&sk->sk_write_queue);
 222         if (sk->sk_send_head != NULL) {
 223                 kfree_skb(sk->sk_send_head);
 224                 sk->sk_send_head = NULL;
 225         }
 226
 227         /* Clean up a referenced DCCP bind bucket. */
 228         if (inet_csk(sk)->icsk_bind_hash != NULL)
 229                 inet_put_port(sk);
 230
 231         kfree(dp->dccps_service_list);
 232         dp->dccps_service_list = NULL;
 233
 234         if (dp->dccps_hc_rx_ackvec != NULL) {
 235                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 236                 dp->dccps_hc_rx_ackvec = NULL;
 237         }
 238         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 239         dp->dccps_hc_rx_ccid = NULL;
 240
 241         /* clean up feature negotiation state */
 242         dccp_feat_list_purge(&dp->dccps_featneg);
 243 }
 244
 245 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 246
 247 static inline int dccp_listen_start(struct sock *sk, int backlog)
 248 {
 249         struct dccp_sock *dp = dccp_sk(sk);
 250
 251         dp->dccps_role = DCCP_ROLE_LISTEN;
 252         /* do not start to listen if feature negotiation setup fails */
 253         if (dccp_feat_finalise_settings(dp))
 254                 return -EPROTO;
 255         return inet_csk_listen_start(sk, backlog);
 256 }
 257
 258 static inline int dccp_need_reset(int state)
 259 {
 260         return state != DCCP_CLOSED && state != DCCP_LISTEN &&
 261                state != DCCP_REQUESTING;
 262 }
 263
 264 int dccp_disconnect(struct sock *sk, int flags)
 265 {
 266         struct inet_connection_sock *icsk = inet_csk(sk);
 267         struct inet_sock *inet = inet_sk(sk);
 268         struct dccp_sock *dp = dccp_sk(sk);
 269         const int old_state = sk->sk_state;
 270
 271         if (old_state != DCCP_CLOSED)
 272                 dccp_set_state(sk, DCCP_CLOSED);
 273
 274         /*
 275          * This corresponds to the ABORT function of RFC793, sec. 3.8
 276          * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
 277          */
 278         if (old_state == DCCP_LISTEN) {
 279                 inet_csk_listen_stop(sk);
 280         } else if (dccp_need_reset(old_state)) {
 281                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 282                 sk->sk_err = ECONNRESET;
 283         } else if (old_state == DCCP_REQUESTING)
 284                 sk->sk_err = ECONNRESET;
 285
 286         dccp_clear_xmit_timers(sk);
 287         ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 288         dp->dccps_hc_rx_ccid = NULL;
 289
 290         __skb_queue_purge(&sk->sk_receive_queue);
 291         __skb_queue_purge(&sk->sk_write_queue);
 292         if (sk->sk_send_head != NULL) {
 293                 __kfree_skb(sk->sk_send_head);
 294                 sk->sk_send_head = NULL;
 295         }
 296
 297         inet->inet_dport = 0;
 298
 299         if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 300                 inet_reset_saddr(sk);
 301
 302         sk->sk_shutdown = 0;
 303         sock_reset_flag(sk, SOCK_DONE);
 304
 305         icsk->icsk_backoff = 0;
 306         inet_csk_delack_init(sk);
 307         __sk_dst_reset(sk);
 308
 309         WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
 310
 311         sk->sk_error_report(sk);
 312         return 0;
 313 }
 314
 315 EXPORT_SYMBOL_GPL(dccp_disconnect);
 316
 317 /*
 318  *      Wait for a DCCP event.
 319  *
 320  *      Note that we don't need to lock the socket, as the upper poll layers
 321  *      take care of normal races (between the test and the event) and we don't
 322  *      go look at any of the socket buffers directly.
 323  */
 324 __poll_t dccp_poll(struct file *file, struct socket *sock,
 325                        poll_table *wait)
 326 {
 327         struct sock *sk = sock->sk;
 328         __poll_t mask;
 329         u8 shutdown;
 330         int state;
 331
 332         sock_poll_wait(file, sock, wait);
 333
 334         state = inet_sk_state_load(sk);
 335         if (state == DCCP_LISTEN)
 336                 return inet_csk_listen_poll(sk);
 337
 338         /* Socket is not locked. We are protected from async events
 339            by poll logic and correct handling of state changes
 340            made by another threads is impossible in any case.
 341          */
 342
 343         mask = 0;
 344         if (READ_ONCE(sk->sk_err))
 345                 mask = EPOLLERR;
 346         shutdown = READ_ONCE(sk->sk_shutdown);
 347
 348         if (shutdown == SHUTDOWN_MASK || state == DCCP_CLOSED)
 349                 mask |= EPOLLHUP;
 350         if (shutdown & RCV_SHUTDOWN)
 351                 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
 352
 353         /* Connected? */
 354         if ((1 << state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 355                 if (atomic_read(&sk->sk_rmem_alloc) > 0)
 356                         mask |= EPOLLIN | EPOLLRDNORM;
 357
 358                 if (!(shutdown & SEND_SHUTDOWN)) {
 359                         if (sk_stream_is_writeable(sk)) {
 360                                 mask |= EPOLLOUT | EPOLLWRNORM;
 361                         } else {  /* send SIGIO later */
 362                                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 363                                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 364
 365                                 /* Race breaker. If space is freed after
 366                                  * wspace test but before the flags are set,
 367                                  * IO signal will be lost.
 368                                  */
 369                                 if (sk_stream_is_writeable(sk))
 370                                         mask |= EPOLLOUT | EPOLLWRNORM;
 371                         }
 372                 }
 373         }
 374         return mask;
 375 }
 376 EXPORT_SYMBOL_GPL(dccp_poll);
 377
 378 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 379 {
 380         int rc = -ENOTCONN;
 381
 382         lock_sock(sk);
 383
 384         if (sk->sk_state == DCCP_LISTEN)
 385                 goto out;
 386
 387         switch (cmd) {
 388         case SIOCOUTQ: {
 389                 int amount = sk_wmem_alloc_get(sk);
 390                 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
 391                  * always 0, comparably to UDP.
 392                  */
 393
 394                 rc = put_user(amount, (int __user *)arg);
 395         }
 396                 break;
 397         case SIOCINQ: {
 398                 struct sk_buff *skb;
 399                 unsigned long amount = 0;
 400
 401                 skb = skb_peek(&sk->sk_receive_queue);
 402                 if (skb != NULL) {
 403                         /*
 404                          * We will only return the amount of this packet since
 405                          * that is all that will be read.
 406                          */
 407                         amount = skb->len;
 408                 }
 409                 rc = put_user(amount, (int __user *)arg);
 410         }
 411                 break;
 412         default:
 413                 rc = -ENOIOCTLCMD;
 414                 break;
 415         }
 416 out:
 417         release_sock(sk);
 418         return rc;
 419 }
 420
 421 EXPORT_SYMBOL_GPL(dccp_ioctl);
 422
 423 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 424                                    sockptr_t optval, unsigned int optlen)
 425 {
 426         struct dccp_sock *dp = dccp_sk(sk);
 427         struct dccp_service_list *sl = NULL;
 428
 429         if (service == DCCP_SERVICE_INVALID_VALUE ||
 430             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 431                 return -EINVAL;
 432
 433         if (optlen > sizeof(service)) {
 434                 sl = kmalloc(optlen, GFP_KERNEL);
 435                 if (sl == NULL)
 436                         return -ENOMEM;
 437
 438                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 439                 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
 440                                 sizeof(service), optlen - sizeof(service)) ||
 441                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 442                         kfree(sl);
 443                         return -EFAULT;
 444                 }
 445         }
 446
 447         lock_sock(sk);
 448         dp->dccps_service = service;
 449
 450         kfree(dp->dccps_service_list);
 451
 452         dp->dccps_service_list = sl;
 453         release_sock(sk);
 454         return 0;
 455 }
 456
 457 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
 458 {
 459         u8 *list, len;
 460         int i, rc;
 461
 462         if (cscov < 0 || cscov > 15)
 463                 return -EINVAL;
 464         /*
 465          * Populate a list of permissible values, in the range cscov...15. This
 466          * is necessary since feature negotiation of single values only works if
 467          * both sides incidentally choose the same value. Since the list starts
 468          * lowest-value first, negotiation will pick the smallest shared value.
 469          */
 470         if (cscov == 0)
 471                 return 0;
 472         len = 16 - cscov;
 473
 474         list = kmalloc(len, GFP_KERNEL);
 475         if (list == NULL)
 476                 return -ENOBUFS;
 477
 478         for (i = 0; i < len; i++)
 479                 list[i] = cscov++;
 480
 481         rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
 482
 483         if (rc == 0) {
 484                 if (rx)
 485                         dccp_sk(sk)->dccps_pcrlen = cscov;
 486                 else
 487                         dccp_sk(sk)->dccps_pcslen = cscov;
 488         }
 489         kfree(list);
 490         return rc;
 491 }
 492
 493 static int dccp_setsockopt_ccid(struct sock *sk, int type,
 494                                 sockptr_t optval, unsigned int optlen)
 495 {
 496         u8 *val;
 497         int rc = 0;
 498
 499         if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
 500                 return -EINVAL;
 501
 502         val = memdup_sockptr(optval, optlen);
 503         if (IS_ERR(val))
 504                 return PTR_ERR(val);
 505
 506         lock_sock(sk);
 507         if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
 508                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
 509
 510         if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
 511                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
 512         release_sock(sk);
 513
 514         kfree(val);
 515         return rc;
 516 }
 517
 518 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 519                 sockptr_t optval, unsigned int optlen)
 520 {
 521         struct dccp_sock *dp = dccp_sk(sk);
 522         int val, err = 0;
 523
 524         switch (optname) {
 525         case DCCP_SOCKOPT_PACKET_SIZE:
 526                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 527                 return 0;
 528         case DCCP_SOCKOPT_CHANGE_L:
 529         case DCCP_SOCKOPT_CHANGE_R:
 530                 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
 531                 return 0;
 532         case DCCP_SOCKOPT_CCID:
 533         case DCCP_SOCKOPT_RX_CCID:
 534         case DCCP_SOCKOPT_TX_CCID:
 535                 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
 536         }
 537
 538         if (optlen < (int)sizeof(int))
 539                 return -EINVAL;
 540
 541         if (copy_from_sockptr(&val, optval, sizeof(int)))
 542                 return -EFAULT;
 543
 544         if (optname == DCCP_SOCKOPT_SERVICE)
 545                 return dccp_setsockopt_service(sk, val, optval, optlen);
 546
 547         lock_sock(sk);
 548         switch (optname) {
 549         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 550                 if (dp->dccps_role != DCCP_ROLE_SERVER)
 551                         err = -EOPNOTSUPP;
 552                 else
 553                         dp->dccps_server_timewait = (val != 0);
 554                 break;
 555         case DCCP_SOCKOPT_SEND_CSCOV:
 556                 err = dccp_setsockopt_cscov(sk, val, false);
 557                 break;
 558         case DCCP_SOCKOPT_RECV_CSCOV:
 559                 err = dccp_setsockopt_cscov(sk, val, true);
 560                 break;
 561         case DCCP_SOCKOPT_QPOLICY_ID:
 562                 if (sk->sk_state != DCCP_CLOSED)
 563                         err = -EISCONN;
 564                 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
 565                         err = -EINVAL;
 566                 else
 567                         dp->dccps_qpolicy = val;
 568                 break;
 569         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
 570                 if (val < 0)
 571                         err = -EINVAL;
 572                 else
 573                         dp->dccps_tx_qlen = val;
 574                 break;
 575         default:
 576                 err = -ENOPROTOOPT;
 577                 break;
 578         }
 579         release_sock(sk);
 580
 581         return err;
 582 }
 583
 584 int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
 585                     unsigned int optlen)
 586 {
 587         if (level != SOL_DCCP)
 588                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 589                                                              optname, optval,
 590                                                              optlen);
 591         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 592 }
 593
 594 EXPORT_SYMBOL_GPL(dccp_setsockopt);
 595
 596 static int dccp_getsockopt_service(struct sock *sk, int len,
 597                                    __be32 __user *optval,
 598                                    int __user *optlen)
 599 {
 600         const struct dccp_sock *dp = dccp_sk(sk);
 601         const struct dccp_service_list *sl;
 602         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 603
 604         lock_sock(sk);
 605         if ((sl = dp->dccps_service_list) != NULL) {
 606                 slen = sl->dccpsl_nr * sizeof(u32);
 607                 total_len += slen;
 608         }
 609
 610         err = -EINVAL;
 611         if (total_len > len)
 612                 goto out;
 613
 614         err = 0;
 615         if (put_user(total_len, optlen) ||
 616             put_user(dp->dccps_service, optval) ||
 617             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 618                 err = -EFAULT;
 619 out:
 620         release_sock(sk);
 621         return err;
 622 }
 623
 624 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 625                     char __user *optval, int __user *optlen)
 626 {
 627         struct dccp_sock *dp;
 628         int val, len;
 629
 630         if (get_user(len, optlen))
 631                 return -EFAULT;
 632
 633         if (len < (int)sizeof(int))
 634                 return -EINVAL;
 635
 636         dp = dccp_sk(sk);
 637
 638         switch (optname) {
 639         case DCCP_SOCKOPT_PACKET_SIZE:
 640                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 641                 return 0;
 642         case DCCP_SOCKOPT_SERVICE:
 643                 return dccp_getsockopt_service(sk, len,
 644                                                (__be32 __user *)optval, optlen);
 645         case DCCP_SOCKOPT_GET_CUR_MPS:
 646                 val = READ_ONCE(dp->dccps_mss_cache);
 647                 break;
 648         case DCCP_SOCKOPT_AVAILABLE_CCIDS:
 649                 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
 650         case DCCP_SOCKOPT_TX_CCID:
 651                 val = ccid_get_current_tx_ccid(dp);
 652                 if (val < 0)
 653                         return -ENOPROTOOPT;
 654                 break;
 655         case DCCP_SOCKOPT_RX_CCID:
 656                 val = ccid_get_current_rx_ccid(dp);
 657                 if (val < 0)
 658                         return -ENOPROTOOPT;
 659                 break;
 660         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 661                 val = dp->dccps_server_timewait;
 662                 break;
 663         case DCCP_SOCKOPT_SEND_CSCOV:
 664                 val = dp->dccps_pcslen;
 665                 break;
 666         case DCCP_SOCKOPT_RECV_CSCOV:
 667                 val = dp->dccps_pcrlen;
 668                 break;
 669         case DCCP_SOCKOPT_QPOLICY_ID:
 670                 val = dp->dccps_qpolicy;
 671                 break;
 672         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
 673                 val = dp->dccps_tx_qlen;
 674                 break;
 675         case 128 ... 191:
 676                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 677                                              len, (u32 __user *)optval, optlen);
 678         case 192 ... 255:
 679                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 680                                              len, (u32 __user *)optval, optlen);
 681         default:
 682                 return -ENOPROTOOPT;
 683         }
 684
 685         len = sizeof(val);
 686         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 687                 return -EFAULT;
 688
 689         return 0;
 690 }
 691
 692 int 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(sk)->icsk_af_ops->getsockopt(sk, level,
 697                                                              optname, optval,
 698                                                              optlen);
 699         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 700 }
 701
 702 EXPORT_SYMBOL_GPL(dccp_getsockopt);
 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         trace_dccp_probe(sk, len);
 754
 755         if (len > READ_ONCE(dp->dccps_mss_cache))
 756                 return -EMSGSIZE;
 757
 758         lock_sock(sk);
 759
 760         timeo = sock_sndtimeo(sk, noblock);
 761
 762         /*
 763          * We have to use sk_stream_wait_connect here to set sk_write_pending,
 764          * so that the trick in dccp_rcv_request_sent_state_process.
 765          */
 766         /* Wait for a connection to finish. */
 767         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 768                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 769                         goto out_release;
 770
 771         size = sk->sk_prot->max_header + len;
 772         release_sock(sk);
 773         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 774         lock_sock(sk);
 775         if (skb == NULL)
 776                 goto out_release;
 777
 778         if (dccp_qpolicy_full(sk)) {
 779                 rc = -EAGAIN;
 780                 goto out_discard;
 781         }
 782
 783         if (sk->sk_state == DCCP_CLOSED) {
 784                 rc = -ENOTCONN;
 785                 goto out_discard;
 786         }
 787
 788         /* We need to check dccps_mss_cache after socket is locked. */
 789         if (len > dp->dccps_mss_cache) {
 790                 rc = -EMSGSIZE;
 791                 goto out_discard;
 792         }
 793
 794         skb_reserve(skb, sk->sk_prot->max_header);
 795         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
 796         if (rc != 0)
 797                 goto out_discard;
 798
 799         rc = dccp_msghdr_parse(msg, skb);
 800         if (rc != 0)
 801                 goto out_discard;
 802
 803         dccp_qpolicy_push(sk, skb);
 804         /*
 805          * The xmit_timer is set if the TX CCID is rate-based and will expire
 806          * when congestion control permits to release further packets into the
 807          * network. Window-based CCIDs do not use this timer.
 808          */
 809         if (!timer_pending(&dp->dccps_xmit_timer))
 810                 dccp_write_xmit(sk);
 811 out_release:
 812         release_sock(sk);
 813         return rc ? : len;
 814 out_discard:
 815         kfree_skb(skb);
 816         goto out_release;
 817 }
 818
 819 EXPORT_SYMBOL_GPL(dccp_sendmsg);
 820
 821 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 822                  int flags, int *addr_len)
 823 {
 824         const struct dccp_hdr *dh;
 825         long timeo;
 826
 827         lock_sock(sk);
 828
 829         if (sk->sk_state == DCCP_LISTEN) {
 830                 len = -ENOTCONN;
 831                 goto out;
 832         }
 833
 834         timeo = sock_rcvtimeo(sk, nonblock);
 835
 836         do {
 837                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 838
 839                 if (skb == NULL)
 840                         goto verify_sock_status;
 841
 842                 dh = dccp_hdr(skb);
 843
 844                 switch (dh->dccph_type) {
 845                 case DCCP_PKT_DATA:
 846                 case DCCP_PKT_DATAACK:
 847                         goto found_ok_skb;
 848
 849                 case DCCP_PKT_CLOSE:
 850                 case DCCP_PKT_CLOSEREQ:
 851                         if (!(flags & MSG_PEEK))
 852                                 dccp_finish_passive_close(sk);
 853                         fallthrough;
 854                 case DCCP_PKT_RESET:
 855                         dccp_pr_debug("found fin (%s) ok!\n",
 856                                       dccp_packet_name(dh->dccph_type));
 857                         len = 0;
 858                         goto found_fin_ok;
 859                 default:
 860                         dccp_pr_debug("packet_type=%s\n",
 861                                       dccp_packet_name(dh->dccph_type));
 862                         sk_eat_skb(sk, skb);
 863                 }
 864 verify_sock_status:
 865                 if (sock_flag(sk, SOCK_DONE)) {
 866                         len = 0;
 867                         break;
 868                 }
 869
 870                 if (sk->sk_err) {
 871                         len = sock_error(sk);
 872                         break;
 873                 }
 874
 875                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
 876                         len = 0;
 877                         break;
 878                 }
 879
 880                 if (sk->sk_state == DCCP_CLOSED) {
 881                         if (!sock_flag(sk, SOCK_DONE)) {
 882                                 /* This occurs when user tries to read
 883                                  * from never connected socket.
 884                                  */
 885                                 len = -ENOTCONN;
 886                                 break;
 887                         }
 888                         len = 0;
 889                         break;
 890                 }
 891
 892                 if (!timeo) {
 893                         len = -EAGAIN;
 894                         break;
 895                 }
 896
 897                 if (signal_pending(current)) {
 898                         len = sock_intr_errno(timeo);
 899                         break;
 900                 }
 901
 902                 sk_wait_data(sk, &timeo, NULL);
 903                 continue;
 904         found_ok_skb:
 905                 if (len > skb->len)
 906                         len = skb->len;
 907                 else if (len < skb->len)
 908                         msg->msg_flags |= MSG_TRUNC;
 909
 910                 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
 911                         /* Exception. Bailout! */
 912                         len = -EFAULT;
 913                         break;
 914                 }
 915                 if (flags & MSG_TRUNC)
 916                         len = skb->len;
 917         found_fin_ok:
 918                 if (!(flags & MSG_PEEK))
 919                         sk_eat_skb(sk, skb);
 920                 break;
 921         } while (1);
 922 out:
 923         release_sock(sk);
 924         return len;
 925 }
 926
 927 EXPORT_SYMBOL_GPL(dccp_recvmsg);
 928
 929 int inet_dccp_listen(struct socket *sock, int backlog)
 930 {
 931         struct sock *sk = sock->sk;
 932         unsigned char old_state;
 933         int err;
 934
 935         lock_sock(sk);
 936
 937         err = -EINVAL;
 938         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 939                 goto out;
 940
 941         old_state = sk->sk_state;
 942         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 943                 goto out;
 944
 945         WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
 946         /* Really, if the socket is already in listen state
 947          * we can only allow the backlog to be adjusted.
 948          */
 949         if (old_state != DCCP_LISTEN) {
 950                 /*
 951                  * FIXME: here it probably should be sk->sk_prot->listen_start
 952                  * see tcp_listen_start
 953                  */
 954                 err = dccp_listen_start(sk, backlog);
 955                 if (err)
 956                         goto out;
 957         }
 958         err = 0;
 959
 960 out:
 961         release_sock(sk);
 962         return err;
 963 }
 964
 965 EXPORT_SYMBOL_GPL(inet_dccp_listen);
 966
 967 static void dccp_terminate_connection(struct sock *sk)
 968 {
 969         u8 next_state = DCCP_CLOSED;
 970
 971         switch (sk->sk_state) {
 972         case DCCP_PASSIVE_CLOSE:
 973         case DCCP_PASSIVE_CLOSEREQ:
 974                 dccp_finish_passive_close(sk);
 975                 break;
 976         case DCCP_PARTOPEN:
 977                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 978                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 979                 fallthrough;
 980         case DCCP_OPEN:
 981                 dccp_send_close(sk, 1);
 982
 983                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 984                     !dccp_sk(sk)->dccps_server_timewait)
 985                         next_state = DCCP_ACTIVE_CLOSEREQ;
 986                 else
 987                         next_state = DCCP_CLOSING;
 988                 fallthrough;
 989         default:
 990                 dccp_set_state(sk, next_state);
 991         }
 992 }
 993
 994 void dccp_close(struct sock *sk, long timeout)
 995 {
 996         struct dccp_sock *dp = dccp_sk(sk);
 997         struct sk_buff *skb;
 998         u32 data_was_unread = 0;
 999         int state;
1000
1001         lock_sock(sk);
1002
1003         sk->sk_shutdown = SHUTDOWN_MASK;
1004
1005         if (sk->sk_state == DCCP_LISTEN) {
1006                 dccp_set_state(sk, DCCP_CLOSED);
1007
1008                 /* Special case. */
1009                 inet_csk_listen_stop(sk);
1010
1011                 goto adjudge_to_death;
1012         }
1013
1014         sk_stop_timer(sk, &dp->dccps_xmit_timer);
1015
1016         /*
1017          * We need to flush the recv. buffs.  We do this only on the
1018          * descriptor close, not protocol-sourced closes, because the
1019           *reader process may not have drained the data yet!
1020          */
1021         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1022                 data_was_unread += skb->len;
1023                 __kfree_skb(skb);
1024         }
1025
1026         /* If socket has been already reset kill it. */
1027         if (sk->sk_state == DCCP_CLOSED)
1028                 goto adjudge_to_death;
1029
1030         if (data_was_unread) {
1031                 /* Unread data was tossed, send an appropriate Reset Code */
1032                 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1033                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1034                 dccp_set_state(sk, DCCP_CLOSED);
1035         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1036                 /* Check zero linger _after_ checking for unread data. */
1037                 sk->sk_prot->disconnect(sk, 0);
1038         } else if (sk->sk_state != DCCP_CLOSED) {
1039                 /*
1040                  * Normal connection termination. May need to wait if there are
1041                  * still packets in the TX queue that are delayed by the CCID.
1042                  */
1043                 dccp_flush_write_queue(sk, &timeout);
1044                 dccp_terminate_connection(sk);
1045         }
1046
1047         /*
1048          * Flush write queue. This may be necessary in several cases:
1049          * - we have been closed by the peer but still have application data;
1050          * - abortive termination (unread data or zero linger time),
1051          * - normal termination but queue could not be flushed within time limit
1052          */
1053         __skb_queue_purge(&sk->sk_write_queue);
1054
1055         sk_stream_wait_close(sk, timeout);
1056
1057 adjudge_to_death:
1058         state = sk->sk_state;
1059         sock_hold(sk);
1060         sock_orphan(sk);
1061
1062         /*
1063          * It is the last release_sock in its life. It will remove backlog.
1064          */
1065         release_sock(sk);
1066         /*
1067          * Now socket is owned by kernel and we acquire BH lock
1068          * to finish close. No need to check for user refs.
1069          */
1070         local_bh_disable();
1071         bh_lock_sock(sk);
1072         WARN_ON(sock_owned_by_user(sk));
1073
1074         this_cpu_inc(dccp_orphan_count);
1075
1076         /* Have we already been destroyed by a softirq or backlog? */
1077         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1078                 goto out;
1079
1080         if (sk->sk_state == DCCP_CLOSED)
1081                 inet_csk_destroy_sock(sk);
1082
1083         /* Otherwise, socket is reprieved until protocol close. */
1084
1085 out:
1086         bh_unlock_sock(sk);
1087         local_bh_enable();
1088         sock_put(sk);
1089 }
1090
1091 EXPORT_SYMBOL_GPL(dccp_close);
1092
1093 void dccp_shutdown(struct sock *sk, int how)
1094 {
1095         dccp_pr_debug("called shutdown(%x)\n", how);
1096 }
1097
1098 EXPORT_SYMBOL_GPL(dccp_shutdown);
1099
1100 static inline int __init dccp_mib_init(void)
1101 {
1102         dccp_statistics = alloc_percpu(struct dccp_mib);
1103         if (!dccp_statistics)
1104                 return -ENOMEM;
1105         return 0;
1106 }
1107
1108 static inline void dccp_mib_exit(void)
1109 {
1110         free_percpu(dccp_statistics);
1111 }
1112
1113 static int thash_entries;
1114 module_param(thash_entries, int, 0444);
1115 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1116
1117 #ifdef CONFIG_IP_DCCP_DEBUG
1118 bool dccp_debug;
1119 module_param(dccp_debug, bool, 0644);
1120 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1121
1122 EXPORT_SYMBOL_GPL(dccp_debug);
1123 #endif
1124
1125 static int __init dccp_init(void)
1126 {
1127         unsigned long goal;
1128         unsigned long nr_pages = totalram_pages();
1129         int ehash_order, bhash_order, i;
1130         int rc;
1131
1132         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1133                      sizeof_field(struct sk_buff, cb));
1134         inet_hashinfo_init(&dccp_hashinfo);
1135         rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1136         if (rc)
1137                 goto out_fail;
1138         rc = -ENOBUFS;
1139         dccp_hashinfo.bind_bucket_cachep =
1140                 kmem_cache_create("dccp_bind_bucket",
1141                                   sizeof(struct inet_bind_bucket), 0,
1142                                   SLAB_HWCACHE_ALIGN, NULL);
1143         if (!dccp_hashinfo.bind_bucket_cachep)
1144                 goto out_free_hashinfo2;
1145
1146         /*
1147          * Size and allocate the main established and bind bucket
1148          * hash tables.
1149          *
1150          * The methodology is similar to that of the buffer cache.
1151          */
1152         if (nr_pages >= (128 * 1024))
1153                 goal = nr_pages >> (21 - PAGE_SHIFT);
1154         else
1155                 goal = nr_pages >> (23 - PAGE_SHIFT);
1156
1157         if (thash_entries)
1158                 goal = (thash_entries *
1159                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1160         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1161                 ;
1162         do {
1163                 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1164                                         sizeof(struct inet_ehash_bucket);
1165
1166                 while (hash_size & (hash_size - 1))
1167                         hash_size--;
1168                 dccp_hashinfo.ehash_mask = hash_size - 1;
1169                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1170                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1171         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1172
1173         if (!dccp_hashinfo.ehash) {
1174                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1175                 goto out_free_bind_bucket_cachep;
1176         }
1177
1178         for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1179                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1180
1181         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1182                         goto out_free_dccp_ehash;
1183
1184         bhash_order = ehash_order;
1185
1186         do {
1187                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1188                                         sizeof(struct inet_bind_hashbucket);
1189                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1190                     bhash_order > 0)
1191                         continue;
1192                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1193                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1194         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1195
1196         if (!dccp_hashinfo.bhash) {
1197                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1198                 goto out_free_dccp_locks;
1199         }
1200
1201         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1202                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1203                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1204         }
1205
1206         rc = dccp_mib_init();
1207         if (rc)
1208                 goto out_free_dccp_bhash;
1209
1210         rc = dccp_ackvec_init();
1211         if (rc)
1212                 goto out_free_dccp_mib;
1213
1214         rc = dccp_sysctl_init();
1215         if (rc)
1216                 goto out_ackvec_exit;
1217
1218         rc = ccid_initialize_builtins();
1219         if (rc)
1220                 goto out_sysctl_exit;
1221
1222         dccp_timestamping_init();
1223
1224         return 0;
1225
1226 out_sysctl_exit:
1227         dccp_sysctl_exit();
1228 out_ackvec_exit:
1229         dccp_ackvec_exit();
1230 out_free_dccp_mib:
1231         dccp_mib_exit();
1232 out_free_dccp_bhash:
1233         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1234 out_free_dccp_locks:
1235         inet_ehash_locks_free(&dccp_hashinfo);
1236 out_free_dccp_ehash:
1237         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1238 out_free_bind_bucket_cachep:
1239         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1240 out_free_hashinfo2:
1241         inet_hashinfo2_free_mod(&dccp_hashinfo);
1242 out_fail:
1243         dccp_hashinfo.bhash = NULL;
1244         dccp_hashinfo.ehash = NULL;
1245         dccp_hashinfo.bind_bucket_cachep = NULL;
1246         return rc;
1247 }
1248
1249 static void __exit dccp_fini(void)
1250 {
1251         ccid_cleanup_builtins();
1252         dccp_mib_exit();
1253         free_pages((unsigned long)dccp_hashinfo.bhash,
1254                    get_order(dccp_hashinfo.bhash_size *
1255                              sizeof(struct inet_bind_hashbucket)));
1256         free_pages((unsigned long)dccp_hashinfo.ehash,
1257                    get_order((dccp_hashinfo.ehash_mask + 1) *
1258                              sizeof(struct inet_ehash_bucket)));
1259         inet_ehash_locks_free(&dccp_hashinfo);
1260         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1261         dccp_ackvec_exit();
1262         dccp_sysctl_exit();
1263         inet_hashinfo2_free_mod(&dccp_hashinfo);
1264 }
1265
1266 module_init(dccp_init);
1267 module_exit(dccp_fini);
1268
1269 MODULE_LICENSE("GPL");
1270 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1271 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");