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/semaphore.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 39 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; 40 41 EXPORT_SYMBOL_GPL(dccp_statistics); 42 43 atomic_t dccp_orphan_count = ATOMIC_INIT(0); 44 45 EXPORT_SYMBOL_GPL(dccp_orphan_count); 46 47 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = { 48 .lhash_lock = RW_LOCK_UNLOCKED, 49 .lhash_users = ATOMIC_INIT(0), 50 .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait), 51 }; 52 53 EXPORT_SYMBOL_GPL(dccp_hashinfo); 54 55 /* the maximum queue length for tx in packets. 0 is no limit */ 56 int sysctl_dccp_tx_qlen __read_mostly = 5; 57 58 void dccp_set_state(struct sock *sk, const int state) 59 { 60 const int oldstate = sk->sk_state; 61 62 dccp_pr_debug("%s(%p) %-10.10s -> %s\n", 63 dccp_role(sk), sk, 64 dccp_state_name(oldstate), dccp_state_name(state)); 65 WARN_ON(state == oldstate); 66 67 switch (state) { 68 case DCCP_OPEN: 69 if (oldstate != DCCP_OPEN) 70 DCCP_INC_STATS(DCCP_MIB_CURRESTAB); 71 break; 72 73 case DCCP_CLOSED: 74 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN) 75 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); 76 77 sk->sk_prot->unhash(sk); 78 if (inet_csk(sk)->icsk_bind_hash != NULL && 79 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 80 inet_put_port(&dccp_hashinfo, sk); 81 /* fall through */ 82 default: 83 if (oldstate == DCCP_OPEN) 84 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); 85 } 86 87 /* Change state AFTER socket is unhashed to avoid closed 88 * socket sitting in hash tables. 89 */ 90 sk->sk_state = state; 91 } 92 93 EXPORT_SYMBOL_GPL(dccp_set_state); 94 95 void dccp_done(struct sock *sk) 96 { 97 dccp_set_state(sk, DCCP_CLOSED); 98 dccp_clear_xmit_timers(sk); 99 100 sk->sk_shutdown = SHUTDOWN_MASK; 101 102 if (!sock_flag(sk, SOCK_DEAD)) 103 sk->sk_state_change(sk); 104 else 105 inet_csk_destroy_sock(sk); 106 } 107 108 EXPORT_SYMBOL_GPL(dccp_done); 109 110 const char *dccp_packet_name(const int type) 111 { 112 static const char *dccp_packet_names[] = { 113 [DCCP_PKT_REQUEST] = "REQUEST", 114 [DCCP_PKT_RESPONSE] = "RESPONSE", 115 [DCCP_PKT_DATA] = "DATA", 116 [DCCP_PKT_ACK] = "ACK", 117 [DCCP_PKT_DATAACK] = "DATAACK", 118 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", 119 [DCCP_PKT_CLOSE] = "CLOSE", 120 [DCCP_PKT_RESET] = "RESET", 121 [DCCP_PKT_SYNC] = "SYNC", 122 [DCCP_PKT_SYNCACK] = "SYNCACK", 123 }; 124 125 if (type >= DCCP_NR_PKT_TYPES) 126 return "INVALID"; 127 else 128 return dccp_packet_names[type]; 129 } 130 131 EXPORT_SYMBOL_GPL(dccp_packet_name); 132 133 const char *dccp_state_name(const int state) 134 { 135 static char *dccp_state_names[] = { 136 [DCCP_OPEN] = "OPEN", 137 [DCCP_REQUESTING] = "REQUESTING", 138 [DCCP_PARTOPEN] = "PARTOPEN", 139 [DCCP_LISTEN] = "LISTEN", 140 [DCCP_RESPOND] = "RESPOND", 141 [DCCP_CLOSING] = "CLOSING", 142 [DCCP_TIME_WAIT] = "TIME_WAIT", 143 [DCCP_CLOSED] = "CLOSED", 144 }; 145 146 if (state >= DCCP_MAX_STATES) 147 return "INVALID STATE!"; 148 else 149 return dccp_state_names[state]; 150 } 151 152 EXPORT_SYMBOL_GPL(dccp_state_name); 153 154 void dccp_hash(struct sock *sk) 155 { 156 inet_hash(&dccp_hashinfo, sk); 157 } 158 159 EXPORT_SYMBOL_GPL(dccp_hash); 160 161 void dccp_unhash(struct sock *sk) 162 { 163 inet_unhash(&dccp_hashinfo, sk); 164 } 165 166 EXPORT_SYMBOL_GPL(dccp_unhash); 167 168 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) 169 { 170 struct dccp_sock *dp = dccp_sk(sk); 171 struct dccp_minisock *dmsk = dccp_msk(sk); 172 struct inet_connection_sock *icsk = inet_csk(sk); 173 174 dccp_minisock_init(&dp->dccps_minisock); 175 do_gettimeofday(&dp->dccps_epoch); 176 177 /* 178 * FIXME: We're hardcoding the CCID, and doing this at this point makes 179 * the listening (master) sock get CCID control blocks, which is not 180 * necessary, but for now, to not mess with the test userspace apps, 181 * lets leave it here, later the real solution is to do this in a 182 * setsockopt(CCIDs-I-want/accept). -acme 183 */ 184 if (likely(ctl_sock_initialized)) { 185 int rc = dccp_feat_init(dmsk); 186 187 if (rc) 188 return rc; 189 190 if (dmsk->dccpms_send_ack_vector) { 191 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL); 192 if (dp->dccps_hc_rx_ackvec == NULL) 193 return -ENOMEM; 194 } 195 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid, 196 sk, GFP_KERNEL); 197 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid, 198 sk, GFP_KERNEL); 199 if (unlikely(dp->dccps_hc_rx_ccid == NULL || 200 dp->dccps_hc_tx_ccid == NULL)) { 201 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 202 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); 203 if (dmsk->dccpms_send_ack_vector) { 204 dccp_ackvec_free(dp->dccps_hc_rx_ackvec); 205 dp->dccps_hc_rx_ackvec = NULL; 206 } 207 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; 208 return -ENOMEM; 209 } 210 } else { 211 /* control socket doesn't need feat nego */ 212 INIT_LIST_HEAD(&dmsk->dccpms_pending); 213 INIT_LIST_HEAD(&dmsk->dccpms_conf); 214 } 215 216 dccp_init_xmit_timers(sk); 217 icsk->icsk_rto = DCCP_TIMEOUT_INIT; 218 icsk->icsk_syn_retries = sysctl_dccp_request_retries; 219 sk->sk_state = DCCP_CLOSED; 220 sk->sk_write_space = dccp_write_space; 221 icsk->icsk_sync_mss = dccp_sync_mss; 222 dp->dccps_mss_cache = 536; 223 dp->dccps_role = DCCP_ROLE_UNDEFINED; 224 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; 225 dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1; 226 227 return 0; 228 } 229 230 EXPORT_SYMBOL_GPL(dccp_init_sock); 231 232 int dccp_destroy_sock(struct sock *sk) 233 { 234 struct dccp_sock *dp = dccp_sk(sk); 235 struct dccp_minisock *dmsk = dccp_msk(sk); 236 237 /* 238 * DCCP doesn't use sk_write_queue, just sk_send_head 239 * for retransmissions 240 */ 241 if (sk->sk_send_head != NULL) { 242 kfree_skb(sk->sk_send_head); 243 sk->sk_send_head = NULL; 244 } 245 246 /* Clean up a referenced DCCP bind bucket. */ 247 if (inet_csk(sk)->icsk_bind_hash != NULL) 248 inet_put_port(&dccp_hashinfo, sk); 249 250 kfree(dp->dccps_service_list); 251 dp->dccps_service_list = NULL; 252 253 if (dmsk->dccpms_send_ack_vector) { 254 dccp_ackvec_free(dp->dccps_hc_rx_ackvec); 255 dp->dccps_hc_rx_ackvec = NULL; 256 } 257 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 258 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); 259 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; 260 261 /* clean up feature negotiation state */ 262 dccp_feat_clean(dmsk); 263 264 return 0; 265 } 266 267 EXPORT_SYMBOL_GPL(dccp_destroy_sock); 268 269 static inline int dccp_listen_start(struct sock *sk, int backlog) 270 { 271 struct dccp_sock *dp = dccp_sk(sk); 272 273 dp->dccps_role = DCCP_ROLE_LISTEN; 274 return inet_csk_listen_start(sk, backlog); 275 } 276 277 int dccp_disconnect(struct sock *sk, int flags) 278 { 279 struct inet_connection_sock *icsk = inet_csk(sk); 280 struct inet_sock *inet = inet_sk(sk); 281 int err = 0; 282 const int old_state = sk->sk_state; 283 284 if (old_state != DCCP_CLOSED) 285 dccp_set_state(sk, DCCP_CLOSED); 286 287 /* ABORT function of RFC793 */ 288 if (old_state == DCCP_LISTEN) { 289 inet_csk_listen_stop(sk); 290 /* FIXME: do the active reset thing */ 291 } else if (old_state == DCCP_REQUESTING) 292 sk->sk_err = ECONNRESET; 293 294 dccp_clear_xmit_timers(sk); 295 __skb_queue_purge(&sk->sk_receive_queue); 296 if (sk->sk_send_head != NULL) { 297 __kfree_skb(sk->sk_send_head); 298 sk->sk_send_head = NULL; 299 } 300 301 inet->dport = 0; 302 303 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 304 inet_reset_saddr(sk); 305 306 sk->sk_shutdown = 0; 307 sock_reset_flag(sk, SOCK_DONE); 308 309 icsk->icsk_backoff = 0; 310 inet_csk_delack_init(sk); 311 __sk_dst_reset(sk); 312 313 BUG_TRAP(!inet->num || icsk->icsk_bind_hash); 314 315 sk->sk_error_report(sk); 316 return err; 317 } 318 319 EXPORT_SYMBOL_GPL(dccp_disconnect); 320 321 /* 322 * Wait for a DCCP event. 323 * 324 * Note that we don't need to lock the socket, as the upper poll layers 325 * take care of normal races (between the test and the event) and we don't 326 * go look at any of the socket buffers directly. 327 */ 328 unsigned int dccp_poll(struct file *file, struct socket *sock, 329 poll_table *wait) 330 { 331 unsigned int mask; 332 struct sock *sk = sock->sk; 333 334 poll_wait(file, sk->sk_sleep, wait); 335 if (sk->sk_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 (sk->sk_err) 345 mask = POLLERR; 346 347 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED) 348 mask |= POLLHUP; 349 if (sk->sk_shutdown & RCV_SHUTDOWN) 350 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 351 352 /* Connected? */ 353 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { 354 if (atomic_read(&sk->sk_rmem_alloc) > 0) 355 mask |= POLLIN | POLLRDNORM; 356 357 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 358 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 359 mask |= POLLOUT | POLLWRNORM; 360 } else { /* send SIGIO later */ 361 set_bit(SOCK_ASYNC_NOSPACE, 362 &sk->sk_socket->flags); 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_wspace(sk) >= sk_stream_min_wspace(sk)) 370 mask |= POLLOUT | POLLWRNORM; 371 } 372 } 373 } 374 return mask; 375 } 376 377 EXPORT_SYMBOL_GPL(dccp_poll); 378 379 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) 380 { 381 dccp_pr_debug("entry\n"); 382 return -ENOIOCTLCMD; 383 } 384 385 EXPORT_SYMBOL_GPL(dccp_ioctl); 386 387 static int dccp_setsockopt_service(struct sock *sk, const __be32 service, 388 char __user *optval, int optlen) 389 { 390 struct dccp_sock *dp = dccp_sk(sk); 391 struct dccp_service_list *sl = NULL; 392 393 if (service == DCCP_SERVICE_INVALID_VALUE || 394 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) 395 return -EINVAL; 396 397 if (optlen > sizeof(service)) { 398 sl = kmalloc(optlen, GFP_KERNEL); 399 if (sl == NULL) 400 return -ENOMEM; 401 402 sl->dccpsl_nr = optlen / sizeof(u32) - 1; 403 if (copy_from_user(sl->dccpsl_list, 404 optval + sizeof(service), 405 optlen - sizeof(service)) || 406 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { 407 kfree(sl); 408 return -EFAULT; 409 } 410 } 411 412 lock_sock(sk); 413 dp->dccps_service = service; 414 415 kfree(dp->dccps_service_list); 416 417 dp->dccps_service_list = sl; 418 release_sock(sk); 419 return 0; 420 } 421 422 /* byte 1 is feature. the rest is the preference list */ 423 static int dccp_setsockopt_change(struct sock *sk, int type, 424 struct dccp_so_feat __user *optval) 425 { 426 struct dccp_so_feat opt; 427 u8 *val; 428 int rc; 429 430 if (copy_from_user(&opt, optval, sizeof(opt))) 431 return -EFAULT; 432 433 val = kmalloc(opt.dccpsf_len, GFP_KERNEL); 434 if (!val) 435 return -ENOMEM; 436 437 if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) { 438 rc = -EFAULT; 439 goto out_free_val; 440 } 441 442 rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat, 443 val, opt.dccpsf_len, GFP_KERNEL); 444 if (rc) 445 goto out_free_val; 446 447 out: 448 return rc; 449 450 out_free_val: 451 kfree(val); 452 goto out; 453 } 454 455 static int do_dccp_setsockopt(struct sock *sk, int level, int optname, 456 char __user *optval, int optlen) 457 { 458 struct dccp_sock *dp = dccp_sk(sk); 459 int val, err = 0; 460 461 if (optlen < sizeof(int)) 462 return -EINVAL; 463 464 if (get_user(val, (int __user *)optval)) 465 return -EFAULT; 466 467 if (optname == DCCP_SOCKOPT_SERVICE) 468 return dccp_setsockopt_service(sk, val, optval, optlen); 469 470 lock_sock(sk); 471 switch (optname) { 472 case DCCP_SOCKOPT_PACKET_SIZE: 473 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 474 err = 0; 475 break; 476 case DCCP_SOCKOPT_CHANGE_L: 477 if (optlen != sizeof(struct dccp_so_feat)) 478 err = -EINVAL; 479 else 480 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L, 481 (struct dccp_so_feat __user *) 482 optval); 483 break; 484 case DCCP_SOCKOPT_CHANGE_R: 485 if (optlen != sizeof(struct dccp_so_feat)) 486 err = -EINVAL; 487 else 488 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R, 489 (struct dccp_so_feat __user *) 490 optval); 491 break; 492 case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */ 493 if (val < 0 || val > 15) 494 err = -EINVAL; 495 else 496 dp->dccps_pcslen = val; 497 break; 498 case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */ 499 if (val < 0 || val > 15) 500 err = -EINVAL; 501 else { 502 dp->dccps_pcrlen = val; 503 /* FIXME: add feature negotiation, 504 * ChangeL(MinimumChecksumCoverage, val) */ 505 } 506 break; 507 default: 508 err = -ENOPROTOOPT; 509 break; 510 } 511 512 release_sock(sk); 513 return err; 514 } 515 516 int dccp_setsockopt(struct sock *sk, int level, int optname, 517 char __user *optval, int optlen) 518 { 519 if (level != SOL_DCCP) 520 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, 521 optname, optval, 522 optlen); 523 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 524 } 525 526 EXPORT_SYMBOL_GPL(dccp_setsockopt); 527 528 #ifdef CONFIG_COMPAT 529 int compat_dccp_setsockopt(struct sock *sk, int level, int optname, 530 char __user *optval, int optlen) 531 { 532 if (level != SOL_DCCP) 533 return inet_csk_compat_setsockopt(sk, level, optname, 534 optval, optlen); 535 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 536 } 537 538 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt); 539 #endif 540 541 static int dccp_getsockopt_service(struct sock *sk, int len, 542 __be32 __user *optval, 543 int __user *optlen) 544 { 545 const struct dccp_sock *dp = dccp_sk(sk); 546 const struct dccp_service_list *sl; 547 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 548 549 lock_sock(sk); 550 if ((sl = dp->dccps_service_list) != NULL) { 551 slen = sl->dccpsl_nr * sizeof(u32); 552 total_len += slen; 553 } 554 555 err = -EINVAL; 556 if (total_len > len) 557 goto out; 558 559 err = 0; 560 if (put_user(total_len, optlen) || 561 put_user(dp->dccps_service, optval) || 562 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 563 err = -EFAULT; 564 out: 565 release_sock(sk); 566 return err; 567 } 568 569 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 570 char __user *optval, int __user *optlen) 571 { 572 struct dccp_sock *dp; 573 int val, len; 574 575 if (get_user(len, optlen)) 576 return -EFAULT; 577 578 if (len < (int)sizeof(int)) 579 return -EINVAL; 580 581 dp = dccp_sk(sk); 582 583 switch (optname) { 584 case DCCP_SOCKOPT_PACKET_SIZE: 585 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 586 return 0; 587 case DCCP_SOCKOPT_SERVICE: 588 return dccp_getsockopt_service(sk, len, 589 (__be32 __user *)optval, optlen); 590 case DCCP_SOCKOPT_SEND_CSCOV: 591 val = dp->dccps_pcslen; 592 len = sizeof(val); 593 break; 594 case DCCP_SOCKOPT_RECV_CSCOV: 595 val = dp->dccps_pcrlen; 596 len = sizeof(val); 597 break; 598 case 128 ... 191: 599 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 600 len, (u32 __user *)optval, optlen); 601 case 192 ... 255: 602 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 603 len, (u32 __user *)optval, optlen); 604 default: 605 return -ENOPROTOOPT; 606 } 607 608 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 609 return -EFAULT; 610 611 return 0; 612 } 613 614 int dccp_getsockopt(struct sock *sk, int level, int optname, 615 char __user *optval, int __user *optlen) 616 { 617 if (level != SOL_DCCP) 618 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, 619 optname, optval, 620 optlen); 621 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 622 } 623 624 EXPORT_SYMBOL_GPL(dccp_getsockopt); 625 626 #ifdef CONFIG_COMPAT 627 int compat_dccp_getsockopt(struct sock *sk, int level, int optname, 628 char __user *optval, int __user *optlen) 629 { 630 if (level != SOL_DCCP) 631 return inet_csk_compat_getsockopt(sk, level, optname, 632 optval, optlen); 633 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 634 } 635 636 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); 637 #endif 638 639 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 640 size_t len) 641 { 642 const struct dccp_sock *dp = dccp_sk(sk); 643 const int flags = msg->msg_flags; 644 const int noblock = flags & MSG_DONTWAIT; 645 struct sk_buff *skb; 646 int rc, size; 647 long timeo; 648 649 if (len > dp->dccps_mss_cache) 650 return -EMSGSIZE; 651 652 lock_sock(sk); 653 654 if (sysctl_dccp_tx_qlen && 655 (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) { 656 rc = -EAGAIN; 657 goto out_release; 658 } 659 660 timeo = sock_sndtimeo(sk, noblock); 661 662 /* 663 * We have to use sk_stream_wait_connect here to set sk_write_pending, 664 * so that the trick in dccp_rcv_request_sent_state_process. 665 */ 666 /* Wait for a connection to finish. */ 667 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING)) 668 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 669 goto out_release; 670 671 size = sk->sk_prot->max_header + len; 672 release_sock(sk); 673 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 674 lock_sock(sk); 675 if (skb == NULL) 676 goto out_release; 677 678 skb_reserve(skb, sk->sk_prot->max_header); 679 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 680 if (rc != 0) 681 goto out_discard; 682 683 skb_queue_tail(&sk->sk_write_queue, skb); 684 dccp_write_xmit(sk,0); 685 out_release: 686 release_sock(sk); 687 return rc ? : len; 688 out_discard: 689 kfree_skb(skb); 690 goto out_release; 691 } 692 693 EXPORT_SYMBOL_GPL(dccp_sendmsg); 694 695 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 696 size_t len, int nonblock, int flags, int *addr_len) 697 { 698 const struct dccp_hdr *dh; 699 long timeo; 700 701 lock_sock(sk); 702 703 if (sk->sk_state == DCCP_LISTEN) { 704 len = -ENOTCONN; 705 goto out; 706 } 707 708 timeo = sock_rcvtimeo(sk, nonblock); 709 710 do { 711 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 712 713 if (skb == NULL) 714 goto verify_sock_status; 715 716 dh = dccp_hdr(skb); 717 718 if (dh->dccph_type == DCCP_PKT_DATA || 719 dh->dccph_type == DCCP_PKT_DATAACK) 720 goto found_ok_skb; 721 722 if (dh->dccph_type == DCCP_PKT_RESET || 723 dh->dccph_type == DCCP_PKT_CLOSE) { 724 dccp_pr_debug("found fin ok!\n"); 725 len = 0; 726 goto found_fin_ok; 727 } 728 dccp_pr_debug("packet_type=%s\n", 729 dccp_packet_name(dh->dccph_type)); 730 sk_eat_skb(sk, skb, 0); 731 verify_sock_status: 732 if (sock_flag(sk, SOCK_DONE)) { 733 len = 0; 734 break; 735 } 736 737 if (sk->sk_err) { 738 len = sock_error(sk); 739 break; 740 } 741 742 if (sk->sk_shutdown & RCV_SHUTDOWN) { 743 len = 0; 744 break; 745 } 746 747 if (sk->sk_state == DCCP_CLOSED) { 748 if (!sock_flag(sk, SOCK_DONE)) { 749 /* This occurs when user tries to read 750 * from never connected socket. 751 */ 752 len = -ENOTCONN; 753 break; 754 } 755 len = 0; 756 break; 757 } 758 759 if (!timeo) { 760 len = -EAGAIN; 761 break; 762 } 763 764 if (signal_pending(current)) { 765 len = sock_intr_errno(timeo); 766 break; 767 } 768 769 sk_wait_data(sk, &timeo); 770 continue; 771 found_ok_skb: 772 if (len > skb->len) 773 len = skb->len; 774 else if (len < skb->len) 775 msg->msg_flags |= MSG_TRUNC; 776 777 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) { 778 /* Exception. Bailout! */ 779 len = -EFAULT; 780 break; 781 } 782 found_fin_ok: 783 if (!(flags & MSG_PEEK)) 784 sk_eat_skb(sk, skb, 0); 785 break; 786 } while (1); 787 out: 788 release_sock(sk); 789 return len; 790 } 791 792 EXPORT_SYMBOL_GPL(dccp_recvmsg); 793 794 int inet_dccp_listen(struct socket *sock, int backlog) 795 { 796 struct sock *sk = sock->sk; 797 unsigned char old_state; 798 int err; 799 800 lock_sock(sk); 801 802 err = -EINVAL; 803 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 804 goto out; 805 806 old_state = sk->sk_state; 807 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 808 goto out; 809 810 /* Really, if the socket is already in listen state 811 * we can only allow the backlog to be adjusted. 812 */ 813 if (old_state != DCCP_LISTEN) { 814 /* 815 * FIXME: here it probably should be sk->sk_prot->listen_start 816 * see tcp_listen_start 817 */ 818 err = dccp_listen_start(sk, backlog); 819 if (err) 820 goto out; 821 } 822 sk->sk_max_ack_backlog = backlog; 823 err = 0; 824 825 out: 826 release_sock(sk); 827 return err; 828 } 829 830 EXPORT_SYMBOL_GPL(inet_dccp_listen); 831 832 static const unsigned char dccp_new_state[] = { 833 /* current state: new state: action: */ 834 [0] = DCCP_CLOSED, 835 [DCCP_OPEN] = DCCP_CLOSING | DCCP_ACTION_FIN, 836 [DCCP_REQUESTING] = DCCP_CLOSED, 837 [DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN, 838 [DCCP_LISTEN] = DCCP_CLOSED, 839 [DCCP_RESPOND] = DCCP_CLOSED, 840 [DCCP_CLOSING] = DCCP_CLOSED, 841 [DCCP_TIME_WAIT] = DCCP_CLOSED, 842 [DCCP_CLOSED] = DCCP_CLOSED, 843 }; 844 845 static int dccp_close_state(struct sock *sk) 846 { 847 const int next = dccp_new_state[sk->sk_state]; 848 const int ns = next & DCCP_STATE_MASK; 849 850 if (ns != sk->sk_state) 851 dccp_set_state(sk, ns); 852 853 return next & DCCP_ACTION_FIN; 854 } 855 856 void dccp_close(struct sock *sk, long timeout) 857 { 858 struct dccp_sock *dp = dccp_sk(sk); 859 struct sk_buff *skb; 860 int state; 861 862 lock_sock(sk); 863 864 sk->sk_shutdown = SHUTDOWN_MASK; 865 866 if (sk->sk_state == DCCP_LISTEN) { 867 dccp_set_state(sk, DCCP_CLOSED); 868 869 /* Special case. */ 870 inet_csk_listen_stop(sk); 871 872 goto adjudge_to_death; 873 } 874 875 sk_stop_timer(sk, &dp->dccps_xmit_timer); 876 877 /* 878 * We need to flush the recv. buffs. We do this only on the 879 * descriptor close, not protocol-sourced closes, because the 880 *reader process may not have drained the data yet! 881 */ 882 /* FIXME: check for unread data */ 883 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 884 __kfree_skb(skb); 885 } 886 887 if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 888 /* Check zero linger _after_ checking for unread data. */ 889 sk->sk_prot->disconnect(sk, 0); 890 } else if (dccp_close_state(sk)) { 891 dccp_send_close(sk, 1); 892 } 893 894 sk_stream_wait_close(sk, timeout); 895 896 adjudge_to_death: 897 state = sk->sk_state; 898 sock_hold(sk); 899 sock_orphan(sk); 900 atomic_inc(sk->sk_prot->orphan_count); 901 902 /* 903 * It is the last release_sock in its life. It will remove backlog. 904 */ 905 release_sock(sk); 906 /* 907 * Now socket is owned by kernel and we acquire BH lock 908 * to finish close. No need to check for user refs. 909 */ 910 local_bh_disable(); 911 bh_lock_sock(sk); 912 BUG_TRAP(!sock_owned_by_user(sk)); 913 914 /* Have we already been destroyed by a softirq or backlog? */ 915 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 916 goto out; 917 918 /* 919 * The last release_sock may have processed the CLOSE or RESET 920 * packet moving sock to CLOSED state, if not we have to fire 921 * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination" 922 * in draft-ietf-dccp-spec-11. -acme 923 */ 924 if (sk->sk_state == DCCP_CLOSING) { 925 /* FIXME: should start at 2 * RTT */ 926 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */ 927 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, 928 inet_csk(sk)->icsk_rto, 929 DCCP_RTO_MAX); 930 #if 0 931 /* Yeah, we should use sk->sk_prot->orphan_count, etc */ 932 dccp_set_state(sk, DCCP_CLOSED); 933 #endif 934 } 935 936 if (sk->sk_state == DCCP_CLOSED) 937 inet_csk_destroy_sock(sk); 938 939 /* Otherwise, socket is reprieved until protocol close. */ 940 941 out: 942 bh_unlock_sock(sk); 943 local_bh_enable(); 944 sock_put(sk); 945 } 946 947 EXPORT_SYMBOL_GPL(dccp_close); 948 949 void dccp_shutdown(struct sock *sk, int how) 950 { 951 dccp_pr_debug("entry\n"); 952 } 953 954 EXPORT_SYMBOL_GPL(dccp_shutdown); 955 956 static int __init dccp_mib_init(void) 957 { 958 int rc = -ENOMEM; 959 960 dccp_statistics[0] = alloc_percpu(struct dccp_mib); 961 if (dccp_statistics[0] == NULL) 962 goto out; 963 964 dccp_statistics[1] = alloc_percpu(struct dccp_mib); 965 if (dccp_statistics[1] == NULL) 966 goto out_free_one; 967 968 rc = 0; 969 out: 970 return rc; 971 out_free_one: 972 free_percpu(dccp_statistics[0]); 973 dccp_statistics[0] = NULL; 974 goto out; 975 976 } 977 978 static void dccp_mib_exit(void) 979 { 980 free_percpu(dccp_statistics[0]); 981 free_percpu(dccp_statistics[1]); 982 dccp_statistics[0] = dccp_statistics[1] = NULL; 983 } 984 985 static int thash_entries; 986 module_param(thash_entries, int, 0444); 987 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 988 989 #ifdef CONFIG_IP_DCCP_DEBUG 990 int dccp_debug; 991 module_param(dccp_debug, int, 0444); 992 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 993 994 EXPORT_SYMBOL_GPL(dccp_debug); 995 #endif 996 997 static int __init dccp_init(void) 998 { 999 unsigned long goal; 1000 int ehash_order, bhash_order, i; 1001 int rc = -ENOBUFS; 1002 1003 dccp_hashinfo.bind_bucket_cachep = 1004 kmem_cache_create("dccp_bind_bucket", 1005 sizeof(struct inet_bind_bucket), 0, 1006 SLAB_HWCACHE_ALIGN, NULL, NULL); 1007 if (!dccp_hashinfo.bind_bucket_cachep) 1008 goto out; 1009 1010 /* 1011 * Size and allocate the main established and bind bucket 1012 * hash tables. 1013 * 1014 * The methodology is similar to that of the buffer cache. 1015 */ 1016 if (num_physpages >= (128 * 1024)) 1017 goal = num_physpages >> (21 - PAGE_SHIFT); 1018 else 1019 goal = num_physpages >> (23 - PAGE_SHIFT); 1020 1021 if (thash_entries) 1022 goal = (thash_entries * 1023 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1024 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1025 ; 1026 do { 1027 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE / 1028 sizeof(struct inet_ehash_bucket); 1029 while (dccp_hashinfo.ehash_size & 1030 (dccp_hashinfo.ehash_size - 1)) 1031 dccp_hashinfo.ehash_size--; 1032 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1033 __get_free_pages(GFP_ATOMIC, ehash_order); 1034 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1035 1036 if (!dccp_hashinfo.ehash) { 1037 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1038 goto out_free_bind_bucket_cachep; 1039 } 1040 1041 for (i = 0; i < dccp_hashinfo.ehash_size; i++) { 1042 rwlock_init(&dccp_hashinfo.ehash[i].lock); 1043 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain); 1044 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].twchain); 1045 } 1046 1047 bhash_order = ehash_order; 1048 1049 do { 1050 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1051 sizeof(struct inet_bind_hashbucket); 1052 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1053 bhash_order > 0) 1054 continue; 1055 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1056 __get_free_pages(GFP_ATOMIC, bhash_order); 1057 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1058 1059 if (!dccp_hashinfo.bhash) { 1060 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1061 goto out_free_dccp_ehash; 1062 } 1063 1064 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1065 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1066 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1067 } 1068 1069 rc = dccp_mib_init(); 1070 if (rc) 1071 goto out_free_dccp_bhash; 1072 1073 rc = dccp_ackvec_init(); 1074 if (rc) 1075 goto out_free_dccp_mib; 1076 1077 rc = dccp_sysctl_init(); 1078 if (rc) 1079 goto out_ackvec_exit; 1080 out: 1081 return rc; 1082 out_ackvec_exit: 1083 dccp_ackvec_exit(); 1084 out_free_dccp_mib: 1085 dccp_mib_exit(); 1086 out_free_dccp_bhash: 1087 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1088 dccp_hashinfo.bhash = NULL; 1089 out_free_dccp_ehash: 1090 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1091 dccp_hashinfo.ehash = NULL; 1092 out_free_bind_bucket_cachep: 1093 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1094 dccp_hashinfo.bind_bucket_cachep = NULL; 1095 goto out; 1096 } 1097 1098 static void __exit dccp_fini(void) 1099 { 1100 dccp_mib_exit(); 1101 free_pages((unsigned long)dccp_hashinfo.bhash, 1102 get_order(dccp_hashinfo.bhash_size * 1103 sizeof(struct inet_bind_hashbucket))); 1104 free_pages((unsigned long)dccp_hashinfo.ehash, 1105 get_order(dccp_hashinfo.ehash_size * 1106 sizeof(struct inet_ehash_bucket))); 1107 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1108 dccp_ackvec_exit(); 1109 dccp_sysctl_exit(); 1110 } 1111 1112 module_init(dccp_init); 1113 module_exit(dccp_fini); 1114 1115 MODULE_LICENSE("GPL"); 1116 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1117 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1118