linux/net/dccp/proto.c
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   1/*
   2 *  net/dccp/proto.c
   3 *
   4 *  An implementation of the DCCP protocol
   5 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
   6 *
   7 *      This program is free software; you can redistribute it and/or modify it
   8 *      under the terms of the GNU General Public License version 2 as
   9 *      published by the Free Software Foundation.
  10 */
  11
  12#include <linux/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 <net/checksum.h>
  24
  25#include <net/inet_sock.h>
  26#include <net/sock.h>
  27#include <net/xfrm.h>
  28
  29#include <asm/ioctls.h>
  30#include <linux/spinlock.h>
  31#include <linux/timer.h>
  32#include <linux/delay.h>
  33#include <linux/poll.h>
  34
  35#include "ccid.h"
  36#include "dccp.h"
  37#include "feat.h"
  38
  39DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
  40
  41EXPORT_SYMBOL_GPL(dccp_statistics);
  42
  43struct percpu_counter dccp_orphan_count;
  44EXPORT_SYMBOL_GPL(dccp_orphan_count);
  45
  46struct inet_hashinfo dccp_hashinfo;
  47EXPORT_SYMBOL_GPL(dccp_hashinfo);
  48
  49/* the maximum queue length for tx in packets. 0 is no limit */
  50int sysctl_dccp_tx_qlen __read_mostly = 5;
  51
  52void dccp_set_state(struct sock *sk, const int state)
  53{
  54        const int oldstate = sk->sk_state;
  55
  56        dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
  57                      dccp_state_name(oldstate), dccp_state_name(state));
  58        WARN_ON(state == oldstate);
  59
  60        switch (state) {
  61        case DCCP_OPEN:
  62                if (oldstate != DCCP_OPEN)
  63                        DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
  64                /* Client retransmits all Confirm options until entering OPEN */
  65                if (oldstate == DCCP_PARTOPEN)
  66                        dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
  67                break;
  68
  69        case DCCP_CLOSED:
  70                if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
  71                    oldstate == DCCP_CLOSING)
  72                        DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
  73
  74                sk->sk_prot->unhash(sk);
  75                if (inet_csk(sk)->icsk_bind_hash != NULL &&
  76                    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
  77                        inet_put_port(sk);
  78                /* fall through */
  79        default:
  80                if (oldstate == DCCP_OPEN)
  81                        DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
  82        }
  83
  84        /* Change state AFTER socket is unhashed to avoid closed
  85         * socket sitting in hash tables.
  86         */
  87        sk->sk_state = state;
  88}
  89
  90EXPORT_SYMBOL_GPL(dccp_set_state);
  91
  92static void dccp_finish_passive_close(struct sock *sk)
  93{
  94        switch (sk->sk_state) {
  95        case DCCP_PASSIVE_CLOSE:
  96                /* Node (client or server) has received Close packet. */
  97                dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
  98                dccp_set_state(sk, DCCP_CLOSED);
  99                break;
 100        case DCCP_PASSIVE_CLOSEREQ:
 101                /*
 102                 * Client received CloseReq. We set the `active' flag so that
 103                 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
 104                 */
 105                dccp_send_close(sk, 1);
 106                dccp_set_state(sk, DCCP_CLOSING);
 107        }
 108}
 109
 110void dccp_done(struct sock *sk)
 111{
 112        dccp_set_state(sk, DCCP_CLOSED);
 113        dccp_clear_xmit_timers(sk);
 114
 115        sk->sk_shutdown = SHUTDOWN_MASK;
 116
 117        if (!sock_flag(sk, SOCK_DEAD))
 118                sk->sk_state_change(sk);
 119        else
 120                inet_csk_destroy_sock(sk);
 121}
 122
 123EXPORT_SYMBOL_GPL(dccp_done);
 124
 125const char *dccp_packet_name(const int type)
 126{
 127        static const char *dccp_packet_names[] = {
 128                [DCCP_PKT_REQUEST]  = "REQUEST",
 129                [DCCP_PKT_RESPONSE] = "RESPONSE",
 130                [DCCP_PKT_DATA]     = "DATA",
 131                [DCCP_PKT_ACK]      = "ACK",
 132                [DCCP_PKT_DATAACK]  = "DATAACK",
 133                [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
 134                [DCCP_PKT_CLOSE]    = "CLOSE",
 135                [DCCP_PKT_RESET]    = "RESET",
 136                [DCCP_PKT_SYNC]     = "SYNC",
 137                [DCCP_PKT_SYNCACK]  = "SYNCACK",
 138        };
 139
 140        if (type >= DCCP_NR_PKT_TYPES)
 141                return "INVALID";
 142        else
 143                return dccp_packet_names[type];
 144}
 145
 146EXPORT_SYMBOL_GPL(dccp_packet_name);
 147
 148const char *dccp_state_name(const int state)
 149{
 150        static char *dccp_state_names[] = {
 151        [DCCP_OPEN]             = "OPEN",
 152        [DCCP_REQUESTING]       = "REQUESTING",
 153        [DCCP_PARTOPEN]         = "PARTOPEN",
 154        [DCCP_LISTEN]           = "LISTEN",
 155        [DCCP_RESPOND]          = "RESPOND",
 156        [DCCP_CLOSING]          = "CLOSING",
 157        [DCCP_ACTIVE_CLOSEREQ]  = "CLOSEREQ",
 158        [DCCP_PASSIVE_CLOSE]    = "PASSIVE_CLOSE",
 159        [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
 160        [DCCP_TIME_WAIT]        = "TIME_WAIT",
 161        [DCCP_CLOSED]           = "CLOSED",
 162        };
 163
 164        if (state >= DCCP_MAX_STATES)
 165                return "INVALID STATE!";
 166        else
 167                return dccp_state_names[state];
 168}
 169
 170EXPORT_SYMBOL_GPL(dccp_state_name);
 171
 172int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 173{
 174        struct dccp_sock *dp = dccp_sk(sk);
 175        struct inet_connection_sock *icsk = inet_csk(sk);
 176
 177        icsk->icsk_rto          = DCCP_TIMEOUT_INIT;
 178        icsk->icsk_syn_retries  = sysctl_dccp_request_retries;
 179        sk->sk_state            = DCCP_CLOSED;
 180        sk->sk_write_space      = dccp_write_space;
 181        icsk->icsk_sync_mss     = dccp_sync_mss;
 182        dp->dccps_mss_cache     = 536;
 183        dp->dccps_rate_last     = jiffies;
 184        dp->dccps_role          = DCCP_ROLE_UNDEFINED;
 185        dp->dccps_service       = DCCP_SERVICE_CODE_IS_ABSENT;
 186        dp->dccps_l_ack_ratio   = dp->dccps_r_ack_ratio = 1;
 187
 188        dccp_init_xmit_timers(sk);
 189
 190        INIT_LIST_HEAD(&dp->dccps_featneg);
 191        /* control socket doesn't need feat nego */
 192        if (likely(ctl_sock_initialized))
 193                return dccp_feat_init(sk);
 194        return 0;
 195}
 196
 197EXPORT_SYMBOL_GPL(dccp_init_sock);
 198
 199void dccp_destroy_sock(struct sock *sk)
 200{
 201        struct dccp_sock *dp = dccp_sk(sk);
 202
 203        /*
 204         * DCCP doesn't use sk_write_queue, just sk_send_head
 205         * for retransmissions
 206         */
 207        if (sk->sk_send_head != NULL) {
 208                kfree_skb(sk->sk_send_head);
 209                sk->sk_send_head = NULL;
 210        }
 211
 212        /* Clean up a referenced DCCP bind bucket. */
 213        if (inet_csk(sk)->icsk_bind_hash != NULL)
 214                inet_put_port(sk);
 215
 216        kfree(dp->dccps_service_list);
 217        dp->dccps_service_list = NULL;
 218
 219        if (dp->dccps_hc_rx_ackvec != NULL) {
 220                dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
 221                dp->dccps_hc_rx_ackvec = NULL;
 222        }
 223        ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
 224        ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 225        dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 226
 227        /* clean up feature negotiation state */
 228        dccp_feat_list_purge(&dp->dccps_featneg);
 229}
 230
 231EXPORT_SYMBOL_GPL(dccp_destroy_sock);
 232
 233static inline int dccp_listen_start(struct sock *sk, int backlog)
 234{
 235        struct dccp_sock *dp = dccp_sk(sk);
 236
 237        dp->dccps_role = DCCP_ROLE_LISTEN;
 238        /* do not start to listen if feature negotiation setup fails */
 239        if (dccp_feat_finalise_settings(dp))
 240                return -EPROTO;
 241        return inet_csk_listen_start(sk, backlog);
 242}
 243
 244static inline int dccp_need_reset(int state)
 245{
 246        return state != DCCP_CLOSED && state != DCCP_LISTEN &&
 247               state != DCCP_REQUESTING;
 248}
 249
 250int dccp_disconnect(struct sock *sk, int flags)
 251{
 252        struct inet_connection_sock *icsk = inet_csk(sk);
 253        struct inet_sock *inet = inet_sk(sk);
 254        int err = 0;
 255        const int old_state = sk->sk_state;
 256
 257        if (old_state != DCCP_CLOSED)
 258                dccp_set_state(sk, DCCP_CLOSED);
 259
 260        /*
 261         * This corresponds to the ABORT function of RFC793, sec. 3.8
 262         * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
 263         */
 264        if (old_state == DCCP_LISTEN) {
 265                inet_csk_listen_stop(sk);
 266        } else if (dccp_need_reset(old_state)) {
 267                dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 268                sk->sk_err = ECONNRESET;
 269        } else if (old_state == DCCP_REQUESTING)
 270                sk->sk_err = ECONNRESET;
 271
 272        dccp_clear_xmit_timers(sk);
 273
 274        __skb_queue_purge(&sk->sk_receive_queue);
 275        __skb_queue_purge(&sk->sk_write_queue);
 276        if (sk->sk_send_head != NULL) {
 277                __kfree_skb(sk->sk_send_head);
 278                sk->sk_send_head = NULL;
 279        }
 280
 281        inet->dport = 0;
 282
 283        if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
 284                inet_reset_saddr(sk);
 285
 286        sk->sk_shutdown = 0;
 287        sock_reset_flag(sk, SOCK_DONE);
 288
 289        icsk->icsk_backoff = 0;
 290        inet_csk_delack_init(sk);
 291        __sk_dst_reset(sk);
 292
 293        WARN_ON(inet->num && !icsk->icsk_bind_hash);
 294
 295        sk->sk_error_report(sk);
 296        return err;
 297}
 298
 299EXPORT_SYMBOL_GPL(dccp_disconnect);
 300
 301/*
 302 *      Wait for a DCCP event.
 303 *
 304 *      Note that we don't need to lock the socket, as the upper poll layers
 305 *      take care of normal races (between the test and the event) and we don't
 306 *      go look at any of the socket buffers directly.
 307 */
 308unsigned int dccp_poll(struct file *file, struct socket *sock,
 309                       poll_table *wait)
 310{
 311        unsigned int mask;
 312        struct sock *sk = sock->sk;
 313
 314        poll_wait(file, sk->sk_sleep, wait);
 315        if (sk->sk_state == DCCP_LISTEN)
 316                return inet_csk_listen_poll(sk);
 317
 318        /* Socket is not locked. We are protected from async events
 319           by poll logic and correct handling of state changes
 320           made by another threads is impossible in any case.
 321         */
 322
 323        mask = 0;
 324        if (sk->sk_err)
 325                mask = POLLERR;
 326
 327        if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
 328                mask |= POLLHUP;
 329        if (sk->sk_shutdown & RCV_SHUTDOWN)
 330                mask |= POLLIN | POLLRDNORM | POLLRDHUP;
 331
 332        /* Connected? */
 333        if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
 334                if (atomic_read(&sk->sk_rmem_alloc) > 0)
 335                        mask |= POLLIN | POLLRDNORM;
 336
 337                if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
 338                        if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 339                                mask |= POLLOUT | POLLWRNORM;
 340                        } else {  /* send SIGIO later */
 341                                set_bit(SOCK_ASYNC_NOSPACE,
 342                                        &sk->sk_socket->flags);
 343                                set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 344
 345                                /* Race breaker. If space is freed after
 346                                 * wspace test but before the flags are set,
 347                                 * IO signal will be lost.
 348                                 */
 349                                if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
 350                                        mask |= POLLOUT | POLLWRNORM;
 351                        }
 352                }
 353        }
 354        return mask;
 355}
 356
 357EXPORT_SYMBOL_GPL(dccp_poll);
 358
 359int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 360{
 361        int rc = -ENOTCONN;
 362
 363        lock_sock(sk);
 364
 365        if (sk->sk_state == DCCP_LISTEN)
 366                goto out;
 367
 368        switch (cmd) {
 369        case SIOCINQ: {
 370                struct sk_buff *skb;
 371                unsigned long amount = 0;
 372
 373                skb = skb_peek(&sk->sk_receive_queue);
 374                if (skb != NULL) {
 375                        /*
 376                         * We will only return the amount of this packet since
 377                         * that is all that will be read.
 378                         */
 379                        amount = skb->len;
 380                }
 381                rc = put_user(amount, (int __user *)arg);
 382        }
 383                break;
 384        default:
 385                rc = -ENOIOCTLCMD;
 386                break;
 387        }
 388out:
 389        release_sock(sk);
 390        return rc;
 391}
 392
 393EXPORT_SYMBOL_GPL(dccp_ioctl);
 394
 395static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
 396                                   char __user *optval, int optlen)
 397{
 398        struct dccp_sock *dp = dccp_sk(sk);
 399        struct dccp_service_list *sl = NULL;
 400
 401        if (service == DCCP_SERVICE_INVALID_VALUE ||
 402            optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
 403                return -EINVAL;
 404
 405        if (optlen > sizeof(service)) {
 406                sl = kmalloc(optlen, GFP_KERNEL);
 407                if (sl == NULL)
 408                        return -ENOMEM;
 409
 410                sl->dccpsl_nr = optlen / sizeof(u32) - 1;
 411                if (copy_from_user(sl->dccpsl_list,
 412                                   optval + sizeof(service),
 413                                   optlen - sizeof(service)) ||
 414                    dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
 415                        kfree(sl);
 416                        return -EFAULT;
 417                }
 418        }
 419
 420        lock_sock(sk);
 421        dp->dccps_service = service;
 422
 423        kfree(dp->dccps_service_list);
 424
 425        dp->dccps_service_list = sl;
 426        release_sock(sk);
 427        return 0;
 428}
 429
 430static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
 431{
 432        u8 *list, len;
 433        int i, rc;
 434
 435        if (cscov < 0 || cscov > 15)
 436                return -EINVAL;
 437        /*
 438         * Populate a list of permissible values, in the range cscov...15. This
 439         * is necessary since feature negotiation of single values only works if
 440         * both sides incidentally choose the same value. Since the list starts
 441         * lowest-value first, negotiation will pick the smallest shared value.
 442         */
 443        if (cscov == 0)
 444                return 0;
 445        len = 16 - cscov;
 446
 447        list = kmalloc(len, GFP_KERNEL);
 448        if (list == NULL)
 449                return -ENOBUFS;
 450
 451        for (i = 0; i < len; i++)
 452                list[i] = cscov++;
 453
 454        rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
 455
 456        if (rc == 0) {
 457                if (rx)
 458                        dccp_sk(sk)->dccps_pcrlen = cscov;
 459                else
 460                        dccp_sk(sk)->dccps_pcslen = cscov;
 461        }
 462        kfree(list);
 463        return rc;
 464}
 465
 466static int dccp_setsockopt_ccid(struct sock *sk, int type,
 467                                char __user *optval, int optlen)
 468{
 469        u8 *val;
 470        int rc = 0;
 471
 472        if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
 473                return -EINVAL;
 474
 475        val = kmalloc(optlen, GFP_KERNEL);
 476        if (val == NULL)
 477                return -ENOMEM;
 478
 479        if (copy_from_user(val, optval, optlen)) {
 480                kfree(val);
 481                return -EFAULT;
 482        }
 483
 484        lock_sock(sk);
 485        if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
 486                rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
 487
 488        if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
 489                rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
 490        release_sock(sk);
 491
 492        kfree(val);
 493        return rc;
 494}
 495
 496static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
 497                char __user *optval, int optlen)
 498{
 499        struct dccp_sock *dp = dccp_sk(sk);
 500        int val, err = 0;
 501
 502        switch (optname) {
 503        case DCCP_SOCKOPT_PACKET_SIZE:
 504                DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 505                return 0;
 506        case DCCP_SOCKOPT_CHANGE_L:
 507        case DCCP_SOCKOPT_CHANGE_R:
 508                DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
 509                return 0;
 510        case DCCP_SOCKOPT_CCID:
 511        case DCCP_SOCKOPT_RX_CCID:
 512        case DCCP_SOCKOPT_TX_CCID:
 513                return dccp_setsockopt_ccid(sk, optname, optval, optlen);
 514        }
 515
 516        if (optlen < (int)sizeof(int))
 517                return -EINVAL;
 518
 519        if (get_user(val, (int __user *)optval))
 520                return -EFAULT;
 521
 522        if (optname == DCCP_SOCKOPT_SERVICE)
 523                return dccp_setsockopt_service(sk, val, optval, optlen);
 524
 525        lock_sock(sk);
 526        switch (optname) {
 527        case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 528                if (dp->dccps_role != DCCP_ROLE_SERVER)
 529                        err = -EOPNOTSUPP;
 530                else
 531                        dp->dccps_server_timewait = (val != 0);
 532                break;
 533        case DCCP_SOCKOPT_SEND_CSCOV:
 534                err = dccp_setsockopt_cscov(sk, val, false);
 535                break;
 536        case DCCP_SOCKOPT_RECV_CSCOV:
 537                err = dccp_setsockopt_cscov(sk, val, true);
 538                break;
 539        default:
 540                err = -ENOPROTOOPT;
 541                break;
 542        }
 543        release_sock(sk);
 544
 545        return err;
 546}
 547
 548int dccp_setsockopt(struct sock *sk, int level, int optname,
 549                    char __user *optval, int optlen)
 550{
 551        if (level != SOL_DCCP)
 552                return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
 553                                                             optname, optval,
 554                                                             optlen);
 555        return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 556}
 557
 558EXPORT_SYMBOL_GPL(dccp_setsockopt);
 559
 560#ifdef CONFIG_COMPAT
 561int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
 562                           char __user *optval, int optlen)
 563{
 564        if (level != SOL_DCCP)
 565                return inet_csk_compat_setsockopt(sk, level, optname,
 566                                                  optval, optlen);
 567        return do_dccp_setsockopt(sk, level, optname, optval, optlen);
 568}
 569
 570EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
 571#endif
 572
 573static int dccp_getsockopt_service(struct sock *sk, int len,
 574                                   __be32 __user *optval,
 575                                   int __user *optlen)
 576{
 577        const struct dccp_sock *dp = dccp_sk(sk);
 578        const struct dccp_service_list *sl;
 579        int err = -ENOENT, slen = 0, total_len = sizeof(u32);
 580
 581        lock_sock(sk);
 582        if ((sl = dp->dccps_service_list) != NULL) {
 583                slen = sl->dccpsl_nr * sizeof(u32);
 584                total_len += slen;
 585        }
 586
 587        err = -EINVAL;
 588        if (total_len > len)
 589                goto out;
 590
 591        err = 0;
 592        if (put_user(total_len, optlen) ||
 593            put_user(dp->dccps_service, optval) ||
 594            (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
 595                err = -EFAULT;
 596out:
 597        release_sock(sk);
 598        return err;
 599}
 600
 601static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
 602                    char __user *optval, int __user *optlen)
 603{
 604        struct dccp_sock *dp;
 605        int val, len;
 606
 607        if (get_user(len, optlen))
 608                return -EFAULT;
 609
 610        if (len < (int)sizeof(int))
 611                return -EINVAL;
 612
 613        dp = dccp_sk(sk);
 614
 615        switch (optname) {
 616        case DCCP_SOCKOPT_PACKET_SIZE:
 617                DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
 618                return 0;
 619        case DCCP_SOCKOPT_SERVICE:
 620                return dccp_getsockopt_service(sk, len,
 621                                               (__be32 __user *)optval, optlen);
 622        case DCCP_SOCKOPT_GET_CUR_MPS:
 623                val = dp->dccps_mss_cache;
 624                break;
 625        case DCCP_SOCKOPT_AVAILABLE_CCIDS:
 626                return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
 627        case DCCP_SOCKOPT_TX_CCID:
 628                val = ccid_get_current_tx_ccid(dp);
 629                if (val < 0)
 630                        return -ENOPROTOOPT;
 631                break;
 632        case DCCP_SOCKOPT_RX_CCID:
 633                val = ccid_get_current_rx_ccid(dp);
 634                if (val < 0)
 635                        return -ENOPROTOOPT;
 636                break;
 637        case DCCP_SOCKOPT_SERVER_TIMEWAIT:
 638                val = dp->dccps_server_timewait;
 639                break;
 640        case DCCP_SOCKOPT_SEND_CSCOV:
 641                val = dp->dccps_pcslen;
 642                break;
 643        case DCCP_SOCKOPT_RECV_CSCOV:
 644                val = dp->dccps_pcrlen;
 645                break;
 646        case 128 ... 191:
 647                return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
 648                                             len, (u32 __user *)optval, optlen);
 649        case 192 ... 255:
 650                return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
 651                                             len, (u32 __user *)optval, optlen);
 652        default:
 653                return -ENOPROTOOPT;
 654        }
 655
 656        len = sizeof(val);
 657        if (put_user(len, optlen) || copy_to_user(optval, &val, len))
 658                return -EFAULT;
 659
 660        return 0;
 661}
 662
 663int dccp_getsockopt(struct sock *sk, int level, int optname,
 664                    char __user *optval, int __user *optlen)
 665{
 666        if (level != SOL_DCCP)
 667                return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
 668                                                             optname, optval,
 669                                                             optlen);
 670        return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 671}
 672
 673EXPORT_SYMBOL_GPL(dccp_getsockopt);
 674
 675#ifdef CONFIG_COMPAT
 676int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
 677                           char __user *optval, int __user *optlen)
 678{
 679        if (level != SOL_DCCP)
 680                return inet_csk_compat_getsockopt(sk, level, optname,
 681                                                  optval, optlen);
 682        return do_dccp_getsockopt(sk, level, optname, optval, optlen);
 683}
 684
 685EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
 686#endif
 687
 688int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 689                 size_t len)
 690{
 691        const struct dccp_sock *dp = dccp_sk(sk);
 692        const int flags = msg->msg_flags;
 693        const int noblock = flags & MSG_DONTWAIT;
 694        struct sk_buff *skb;
 695        int rc, size;
 696        long timeo;
 697
 698        if (len > dp->dccps_mss_cache)
 699                return -EMSGSIZE;
 700
 701        lock_sock(sk);
 702
 703        if (sysctl_dccp_tx_qlen &&
 704            (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
 705                rc = -EAGAIN;
 706                goto out_release;
 707        }
 708
 709        timeo = sock_sndtimeo(sk, noblock);
 710
 711        /*
 712         * We have to use sk_stream_wait_connect here to set sk_write_pending,
 713         * so that the trick in dccp_rcv_request_sent_state_process.
 714         */
 715        /* Wait for a connection to finish. */
 716        if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
 717                if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
 718                        goto out_release;
 719
 720        size = sk->sk_prot->max_header + len;
 721        release_sock(sk);
 722        skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 723        lock_sock(sk);
 724        if (skb == NULL)
 725                goto out_release;
 726
 727        skb_reserve(skb, sk->sk_prot->max_header);
 728        rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 729        if (rc != 0)
 730                goto out_discard;
 731
 732        skb_queue_tail(&sk->sk_write_queue, skb);
 733        dccp_write_xmit(sk,0);
 734out_release:
 735        release_sock(sk);
 736        return rc ? : len;
 737out_discard:
 738        kfree_skb(skb);
 739        goto out_release;
 740}
 741
 742EXPORT_SYMBOL_GPL(dccp_sendmsg);
 743
 744int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 745                 size_t len, int nonblock, int flags, int *addr_len)
 746{
 747        const struct dccp_hdr *dh;
 748        long timeo;
 749
 750        lock_sock(sk);
 751
 752        if (sk->sk_state == DCCP_LISTEN) {
 753                len = -ENOTCONN;
 754                goto out;
 755        }
 756
 757        timeo = sock_rcvtimeo(sk, nonblock);
 758
 759        do {
 760                struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 761
 762                if (skb == NULL)
 763                        goto verify_sock_status;
 764
 765                dh = dccp_hdr(skb);
 766
 767                switch (dh->dccph_type) {
 768                case DCCP_PKT_DATA:
 769                case DCCP_PKT_DATAACK:
 770                        goto found_ok_skb;
 771
 772                case DCCP_PKT_CLOSE:
 773                case DCCP_PKT_CLOSEREQ:
 774                        if (!(flags & MSG_PEEK))
 775                                dccp_finish_passive_close(sk);
 776                        /* fall through */
 777                case DCCP_PKT_RESET:
 778                        dccp_pr_debug("found fin (%s) ok!\n",
 779                                      dccp_packet_name(dh->dccph_type));
 780                        len = 0;
 781                        goto found_fin_ok;
 782                default:
 783                        dccp_pr_debug("packet_type=%s\n",
 784                                      dccp_packet_name(dh->dccph_type));
 785                        sk_eat_skb(sk, skb, 0);
 786                }
 787verify_sock_status:
 788                if (sock_flag(sk, SOCK_DONE)) {
 789                        len = 0;
 790                        break;
 791                }
 792
 793                if (sk->sk_err) {
 794                        len = sock_error(sk);
 795                        break;
 796                }
 797
 798                if (sk->sk_shutdown & RCV_SHUTDOWN) {
 799                        len = 0;
 800                        break;
 801                }
 802
 803                if (sk->sk_state == DCCP_CLOSED) {
 804                        if (!sock_flag(sk, SOCK_DONE)) {
 805                                /* This occurs when user tries to read
 806                                 * from never connected socket.
 807                                 */
 808                                len = -ENOTCONN;
 809                                break;
 810                        }
 811                        len = 0;
 812                        break;
 813                }
 814
 815                if (!timeo) {
 816                        len = -EAGAIN;
 817                        break;
 818                }
 819
 820                if (signal_pending(current)) {
 821                        len = sock_intr_errno(timeo);
 822                        break;
 823                }
 824
 825                sk_wait_data(sk, &timeo);
 826                continue;
 827        found_ok_skb:
 828                if (len > skb->len)
 829                        len = skb->len;
 830                else if (len < skb->len)
 831                        msg->msg_flags |= MSG_TRUNC;
 832
 833                if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
 834                        /* Exception. Bailout! */
 835                        len = -EFAULT;
 836                        break;
 837                }
 838        found_fin_ok:
 839                if (!(flags & MSG_PEEK))
 840                        sk_eat_skb(sk, skb, 0);
 841                break;
 842        } while (1);
 843out:
 844        release_sock(sk);
 845        return len;
 846}
 847
 848EXPORT_SYMBOL_GPL(dccp_recvmsg);
 849
 850int inet_dccp_listen(struct socket *sock, int backlog)
 851{
 852        struct sock *sk = sock->sk;
 853        unsigned char old_state;
 854        int err;
 855
 856        lock_sock(sk);
 857
 858        err = -EINVAL;
 859        if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
 860                goto out;
 861
 862        old_state = sk->sk_state;
 863        if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
 864                goto out;
 865
 866        /* Really, if the socket is already in listen state
 867         * we can only allow the backlog to be adjusted.
 868         */
 869        if (old_state != DCCP_LISTEN) {
 870                /*
 871                 * FIXME: here it probably should be sk->sk_prot->listen_start
 872                 * see tcp_listen_start
 873                 */
 874                err = dccp_listen_start(sk, backlog);
 875                if (err)
 876                        goto out;
 877        }
 878        sk->sk_max_ack_backlog = backlog;
 879        err = 0;
 880
 881out:
 882        release_sock(sk);
 883        return err;
 884}
 885
 886EXPORT_SYMBOL_GPL(inet_dccp_listen);
 887
 888static void dccp_terminate_connection(struct sock *sk)
 889{
 890        u8 next_state = DCCP_CLOSED;
 891
 892        switch (sk->sk_state) {
 893        case DCCP_PASSIVE_CLOSE:
 894        case DCCP_PASSIVE_CLOSEREQ:
 895                dccp_finish_passive_close(sk);
 896                break;
 897        case DCCP_PARTOPEN:
 898                dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
 899                inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 900                /* fall through */
 901        case DCCP_OPEN:
 902                dccp_send_close(sk, 1);
 903
 904                if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
 905                    !dccp_sk(sk)->dccps_server_timewait)
 906                        next_state = DCCP_ACTIVE_CLOSEREQ;
 907                else
 908                        next_state = DCCP_CLOSING;
 909                /* fall through */
 910        default:
 911                dccp_set_state(sk, next_state);
 912        }
 913}
 914
 915void dccp_close(struct sock *sk, long timeout)
 916{
 917        struct dccp_sock *dp = dccp_sk(sk);
 918        struct sk_buff *skb;
 919        u32 data_was_unread = 0;
 920        int state;
 921
 922        lock_sock(sk);
 923
 924        sk->sk_shutdown = SHUTDOWN_MASK;
 925
 926        if (sk->sk_state == DCCP_LISTEN) {
 927                dccp_set_state(sk, DCCP_CLOSED);
 928
 929                /* Special case. */
 930                inet_csk_listen_stop(sk);
 931
 932                goto adjudge_to_death;
 933        }
 934
 935        sk_stop_timer(sk, &dp->dccps_xmit_timer);
 936
 937        /*
 938         * We need to flush the recv. buffs.  We do this only on the
 939         * descriptor close, not protocol-sourced closes, because the
 940          *reader process may not have drained the data yet!
 941         */
 942        while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 943                data_was_unread += skb->len;
 944                __kfree_skb(skb);
 945        }
 946
 947        if (data_was_unread) {
 948                /* Unread data was tossed, send an appropriate Reset Code */
 949                DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
 950                dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
 951                dccp_set_state(sk, DCCP_CLOSED);
 952        } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
 953                /* Check zero linger _after_ checking for unread data. */
 954                sk->sk_prot->disconnect(sk, 0);
 955        } else if (sk->sk_state != DCCP_CLOSED) {
 956                dccp_terminate_connection(sk);
 957        }
 958
 959        sk_stream_wait_close(sk, timeout);
 960
 961adjudge_to_death:
 962        state = sk->sk_state;
 963        sock_hold(sk);
 964        sock_orphan(sk);
 965
 966        /*
 967         * It is the last release_sock in its life. It will remove backlog.
 968         */
 969        release_sock(sk);
 970        /*
 971         * Now socket is owned by kernel and we acquire BH lock
 972         * to finish close. No need to check for user refs.
 973         */
 974        local_bh_disable();
 975        bh_lock_sock(sk);
 976        WARN_ON(sock_owned_by_user(sk));
 977
 978        percpu_counter_inc(sk->sk_prot->orphan_count);
 979
 980        /* Have we already been destroyed by a softirq or backlog? */
 981        if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
 982                goto out;
 983
 984        if (sk->sk_state == DCCP_CLOSED)
 985                inet_csk_destroy_sock(sk);
 986
 987        /* Otherwise, socket is reprieved until protocol close. */
 988
 989out:
 990        bh_unlock_sock(sk);
 991        local_bh_enable();
 992        sock_put(sk);
 993}
 994
 995EXPORT_SYMBOL_GPL(dccp_close);
 996
 997void dccp_shutdown(struct sock *sk, int how)
 998{
 999        dccp_pr_debug("called shutdown(%x)\n", how);
1000}
1001
1002EXPORT_SYMBOL_GPL(dccp_shutdown);
1003
1004static inline int dccp_mib_init(void)
1005{
1006        return snmp_mib_init((void**)dccp_statistics, sizeof(struct dccp_mib));
1007}
1008
1009static inline void dccp_mib_exit(void)
1010{
1011        snmp_mib_free((void**)dccp_statistics);
1012}
1013
1014static int thash_entries;
1015module_param(thash_entries, int, 0444);
1016MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1017
1018#ifdef CONFIG_IP_DCCP_DEBUG
1019int dccp_debug;
1020module_param(dccp_debug, bool, 0644);
1021MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1022
1023EXPORT_SYMBOL_GPL(dccp_debug);
1024#endif
1025
1026static 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;
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 (num_physpages >= (128 * 1024))
1053                goal = num_physpages >> (21 - PAGE_SHIFT);
1054        else
1055                goal = num_physpages >> (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                dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1064                                        sizeof(struct inet_ehash_bucket);
1065                while (dccp_hashinfo.ehash_size &
1066                       (dccp_hashinfo.ehash_size - 1))
1067                        dccp_hashinfo.ehash_size--;
1068                dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1069                        __get_free_pages(GFP_ATOMIC, ehash_order);
1070        } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1071
1072        if (!dccp_hashinfo.ehash) {
1073                DCCP_CRIT("Failed to allocate DCCP established hash table");
1074                goto out_free_bind_bucket_cachep;
1075        }
1076
1077        for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
1078                INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1079                INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1080        }
1081
1082        if (inet_ehash_locks_alloc(&dccp_hashinfo))
1083                        goto out_free_dccp_ehash;
1084
1085        bhash_order = ehash_order;
1086
1087        do {
1088                dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1089                                        sizeof(struct inet_bind_hashbucket);
1090                if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1091                    bhash_order > 0)
1092                        continue;
1093                dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1094                        __get_free_pages(GFP_ATOMIC, bhash_order);
1095        } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1096
1097        if (!dccp_hashinfo.bhash) {
1098                DCCP_CRIT("Failed to allocate DCCP bind hash table");
1099                goto out_free_dccp_locks;
1100        }
1101
1102        for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1103                spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1104                INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1105        }
1106
1107        rc = dccp_mib_init();
1108        if (rc)
1109                goto out_free_dccp_bhash;
1110
1111        rc = dccp_ackvec_init();
1112        if (rc)
1113                goto out_free_dccp_mib;
1114
1115        rc = dccp_sysctl_init();
1116        if (rc)
1117                goto out_ackvec_exit;
1118
1119        rc = ccid_initialize_builtins();
1120        if (rc)
1121                goto out_sysctl_exit;
1122
1123        dccp_timestamping_init();
1124out:
1125        return rc;
1126out_sysctl_exit:
1127        dccp_sysctl_exit();
1128out_ackvec_exit:
1129        dccp_ackvec_exit();
1130out_free_dccp_mib:
1131        dccp_mib_exit();
1132out_free_dccp_bhash:
1133        free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1134        dccp_hashinfo.bhash = NULL;
1135out_free_dccp_locks:
1136        inet_ehash_locks_free(&dccp_hashinfo);
1137out_free_dccp_ehash:
1138        free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1139        dccp_hashinfo.ehash = NULL;
1140out_free_bind_bucket_cachep:
1141        kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1142        dccp_hashinfo.bind_bucket_cachep = NULL;
1143out_free_percpu:
1144        percpu_counter_destroy(&dccp_orphan_count);
1145        goto out;
1146}
1147
1148static void __exit dccp_fini(void)
1149{
1150        ccid_cleanup_builtins();
1151        dccp_mib_exit();
1152        free_pages((unsigned long)dccp_hashinfo.bhash,
1153                   get_order(dccp_hashinfo.bhash_size *
1154                             sizeof(struct inet_bind_hashbucket)));
1155        free_pages((unsigned long)dccp_hashinfo.ehash,
1156                   get_order(dccp_hashinfo.ehash_size *
1157                             sizeof(struct inet_ehash_bucket)));
1158        inet_ehash_locks_free(&dccp_hashinfo);
1159        kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1160        dccp_ackvec_exit();
1161        dccp_sysctl_exit();
1162}
1163
1164module_init(dccp_init);
1165module_exit(dccp_fini);
1166
1167MODULE_LICENSE("GPL");
1168MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1169MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
1170