1 /* 2 * net/dccp/proto.c 3 * 4 * An implementation of the DCCP protocol 5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/dccp.h> 13 #include <linux/module.h> 14 #include <linux/types.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/skbuff.h> 18 #include <linux/netdevice.h> 19 #include <linux/in.h> 20 #include <linux/if_arp.h> 21 #include <linux/init.h> 22 #include <linux/random.h> 23 #include <linux/slab.h> 24 #include <net/checksum.h> 25 26 #include <net/inet_sock.h> 27 #include <net/sock.h> 28 #include <net/xfrm.h> 29 30 #include <asm/ioctls.h> 31 #include <linux/spinlock.h> 32 #include <linux/timer.h> 33 #include <linux/delay.h> 34 #include <linux/poll.h> 35 36 #include "ccid.h" 37 #include "dccp.h" 38 #include "feat.h" 39 40 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; 41 42 EXPORT_SYMBOL_GPL(dccp_statistics); 43 44 struct percpu_counter dccp_orphan_count; 45 EXPORT_SYMBOL_GPL(dccp_orphan_count); 46 47 struct inet_hashinfo dccp_hashinfo; 48 EXPORT_SYMBOL_GPL(dccp_hashinfo); 49 50 /* the maximum queue length for tx in packets. 0 is no limit */ 51 int sysctl_dccp_tx_qlen __read_mostly = 5; 52 53 #ifdef CONFIG_IP_DCCP_DEBUG 54 static const char *dccp_state_name(const int state) 55 { 56 static const char *const dccp_state_names[] = { 57 [DCCP_OPEN] = "OPEN", 58 [DCCP_REQUESTING] = "REQUESTING", 59 [DCCP_PARTOPEN] = "PARTOPEN", 60 [DCCP_LISTEN] = "LISTEN", 61 [DCCP_RESPOND] = "RESPOND", 62 [DCCP_CLOSING] = "CLOSING", 63 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ", 64 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE", 65 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ", 66 [DCCP_TIME_WAIT] = "TIME_WAIT", 67 [DCCP_CLOSED] = "CLOSED", 68 }; 69 70 if (state >= DCCP_MAX_STATES) 71 return "INVALID STATE!"; 72 else 73 return dccp_state_names[state]; 74 } 75 #endif 76 77 void dccp_set_state(struct sock *sk, const int state) 78 { 79 const int oldstate = sk->sk_state; 80 81 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk, 82 dccp_state_name(oldstate), dccp_state_name(state)); 83 WARN_ON(state == oldstate); 84 85 switch (state) { 86 case DCCP_OPEN: 87 if (oldstate != DCCP_OPEN) 88 DCCP_INC_STATS(DCCP_MIB_CURRESTAB); 89 /* Client retransmits all Confirm options until entering OPEN */ 90 if (oldstate == DCCP_PARTOPEN) 91 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); 92 break; 93 94 case DCCP_CLOSED: 95 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ || 96 oldstate == DCCP_CLOSING) 97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); 98 99 sk->sk_prot->unhash(sk); 100 if (inet_csk(sk)->icsk_bind_hash != NULL && 101 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 102 inet_put_port(sk); 103 /* fall through */ 104 default: 105 if (oldstate == DCCP_OPEN) 106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); 107 } 108 109 /* Change state AFTER socket is unhashed to avoid closed 110 * socket sitting in hash tables. 111 */ 112 sk->sk_state = state; 113 } 114 115 EXPORT_SYMBOL_GPL(dccp_set_state); 116 117 static void dccp_finish_passive_close(struct sock *sk) 118 { 119 switch (sk->sk_state) { 120 case DCCP_PASSIVE_CLOSE: 121 /* Node (client or server) has received Close packet. */ 122 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); 123 dccp_set_state(sk, DCCP_CLOSED); 124 break; 125 case DCCP_PASSIVE_CLOSEREQ: 126 /* 127 * Client received CloseReq. We set the `active' flag so that 128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3. 129 */ 130 dccp_send_close(sk, 1); 131 dccp_set_state(sk, DCCP_CLOSING); 132 } 133 } 134 135 void dccp_done(struct sock *sk) 136 { 137 dccp_set_state(sk, DCCP_CLOSED); 138 dccp_clear_xmit_timers(sk); 139 140 sk->sk_shutdown = SHUTDOWN_MASK; 141 142 if (!sock_flag(sk, SOCK_DEAD)) 143 sk->sk_state_change(sk); 144 else 145 inet_csk_destroy_sock(sk); 146 } 147 148 EXPORT_SYMBOL_GPL(dccp_done); 149 150 const char *dccp_packet_name(const int type) 151 { 152 static const char *const dccp_packet_names[] = { 153 [DCCP_PKT_REQUEST] = "REQUEST", 154 [DCCP_PKT_RESPONSE] = "RESPONSE", 155 [DCCP_PKT_DATA] = "DATA", 156 [DCCP_PKT_ACK] = "ACK", 157 [DCCP_PKT_DATAACK] = "DATAACK", 158 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", 159 [DCCP_PKT_CLOSE] = "CLOSE", 160 [DCCP_PKT_RESET] = "RESET", 161 [DCCP_PKT_SYNC] = "SYNC", 162 [DCCP_PKT_SYNCACK] = "SYNCACK", 163 }; 164 165 if (type >= DCCP_NR_PKT_TYPES) 166 return "INVALID"; 167 else 168 return dccp_packet_names[type]; 169 } 170 171 EXPORT_SYMBOL_GPL(dccp_packet_name); 172 173 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) 174 { 175 struct dccp_sock *dp = dccp_sk(sk); 176 struct inet_connection_sock *icsk = inet_csk(sk); 177 178 icsk->icsk_rto = DCCP_TIMEOUT_INIT; 179 icsk->icsk_syn_retries = sysctl_dccp_request_retries; 180 sk->sk_state = DCCP_CLOSED; 181 sk->sk_write_space = dccp_write_space; 182 icsk->icsk_sync_mss = dccp_sync_mss; 183 dp->dccps_mss_cache = 536; 184 dp->dccps_rate_last = jiffies; 185 dp->dccps_role = DCCP_ROLE_UNDEFINED; 186 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; 187 dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1; 188 189 dccp_init_xmit_timers(sk); 190 191 INIT_LIST_HEAD(&dp->dccps_featneg); 192 /* control socket doesn't need feat nego */ 193 if (likely(ctl_sock_initialized)) 194 return dccp_feat_init(sk); 195 return 0; 196 } 197 198 EXPORT_SYMBOL_GPL(dccp_init_sock); 199 200 void dccp_destroy_sock(struct sock *sk) 201 { 202 struct dccp_sock *dp = dccp_sk(sk); 203 204 /* 205 * DCCP doesn't use sk_write_queue, just sk_send_head 206 * for retransmissions 207 */ 208 if (sk->sk_send_head != NULL) { 209 kfree_skb(sk->sk_send_head); 210 sk->sk_send_head = NULL; 211 } 212 213 /* Clean up a referenced DCCP bind bucket. */ 214 if (inet_csk(sk)->icsk_bind_hash != NULL) 215 inet_put_port(sk); 216 217 kfree(dp->dccps_service_list); 218 dp->dccps_service_list = NULL; 219 220 if (dp->dccps_hc_rx_ackvec != NULL) { 221 dccp_ackvec_free(dp->dccps_hc_rx_ackvec); 222 dp->dccps_hc_rx_ackvec = NULL; 223 } 224 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 225 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); 226 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; 227 228 /* clean up feature negotiation state */ 229 dccp_feat_list_purge(&dp->dccps_featneg); 230 } 231 232 EXPORT_SYMBOL_GPL(dccp_destroy_sock); 233 234 static inline int dccp_listen_start(struct sock *sk, int backlog) 235 { 236 struct dccp_sock *dp = dccp_sk(sk); 237 238 dp->dccps_role = DCCP_ROLE_LISTEN; 239 /* do not start to listen if feature negotiation setup fails */ 240 if (dccp_feat_finalise_settings(dp)) 241 return -EPROTO; 242 return inet_csk_listen_start(sk, backlog); 243 } 244 245 static inline int dccp_need_reset(int state) 246 { 247 return state != DCCP_CLOSED && state != DCCP_LISTEN && 248 state != DCCP_REQUESTING; 249 } 250 251 int dccp_disconnect(struct sock *sk, int flags) 252 { 253 struct inet_connection_sock *icsk = inet_csk(sk); 254 struct inet_sock *inet = inet_sk(sk); 255 int err = 0; 256 const int old_state = sk->sk_state; 257 258 if (old_state != DCCP_CLOSED) 259 dccp_set_state(sk, DCCP_CLOSED); 260 261 /* 262 * This corresponds to the ABORT function of RFC793, sec. 3.8 263 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted". 264 */ 265 if (old_state == DCCP_LISTEN) { 266 inet_csk_listen_stop(sk); 267 } else if (dccp_need_reset(old_state)) { 268 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 269 sk->sk_err = ECONNRESET; 270 } else if (old_state == DCCP_REQUESTING) 271 sk->sk_err = ECONNRESET; 272 273 dccp_clear_xmit_timers(sk); 274 275 __skb_queue_purge(&sk->sk_receive_queue); 276 __skb_queue_purge(&sk->sk_write_queue); 277 if (sk->sk_send_head != NULL) { 278 __kfree_skb(sk->sk_send_head); 279 sk->sk_send_head = NULL; 280 } 281 282 inet->inet_dport = 0; 283 284 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 285 inet_reset_saddr(sk); 286 287 sk->sk_shutdown = 0; 288 sock_reset_flag(sk, SOCK_DONE); 289 290 icsk->icsk_backoff = 0; 291 inet_csk_delack_init(sk); 292 __sk_dst_reset(sk); 293 294 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 295 296 sk->sk_error_report(sk); 297 return err; 298 } 299 300 EXPORT_SYMBOL_GPL(dccp_disconnect); 301 302 /* 303 * Wait for a DCCP event. 304 * 305 * Note that we don't need to lock the socket, as the upper poll layers 306 * take care of normal races (between the test and the event) and we don't 307 * go look at any of the socket buffers directly. 308 */ 309 unsigned int dccp_poll(struct file *file, struct socket *sock, 310 poll_table *wait) 311 { 312 unsigned int mask; 313 struct sock *sk = sock->sk; 314 315 sock_poll_wait(file, sk_sleep(sk), wait); 316 if (sk->sk_state == DCCP_LISTEN) 317 return inet_csk_listen_poll(sk); 318 319 /* Socket is not locked. We are protected from async events 320 by poll logic and correct handling of state changes 321 made by another threads is impossible in any case. 322 */ 323 324 mask = 0; 325 if (sk->sk_err) 326 mask = POLLERR; 327 328 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED) 329 mask |= POLLHUP; 330 if (sk->sk_shutdown & RCV_SHUTDOWN) 331 mask |= POLLIN | POLLRDNORM | POLLRDHUP; 332 333 /* Connected? */ 334 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { 335 if (atomic_read(&sk->sk_rmem_alloc) > 0) 336 mask |= POLLIN | POLLRDNORM; 337 338 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 339 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 340 mask |= POLLOUT | POLLWRNORM; 341 } else { /* send SIGIO later */ 342 set_bit(SOCK_ASYNC_NOSPACE, 343 &sk->sk_socket->flags); 344 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 345 346 /* Race breaker. If space is freed after 347 * wspace test but before the flags are set, 348 * IO signal will be lost. 349 */ 350 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) 351 mask |= POLLOUT | POLLWRNORM; 352 } 353 } 354 } 355 return mask; 356 } 357 358 EXPORT_SYMBOL_GPL(dccp_poll); 359 360 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) 361 { 362 int rc = -ENOTCONN; 363 364 lock_sock(sk); 365 366 if (sk->sk_state == DCCP_LISTEN) 367 goto out; 368 369 switch (cmd) { 370 case SIOCINQ: { 371 struct sk_buff *skb; 372 unsigned long amount = 0; 373 374 skb = skb_peek(&sk->sk_receive_queue); 375 if (skb != NULL) { 376 /* 377 * We will only return the amount of this packet since 378 * that is all that will be read. 379 */ 380 amount = skb->len; 381 } 382 rc = put_user(amount, (int __user *)arg); 383 } 384 break; 385 default: 386 rc = -ENOIOCTLCMD; 387 break; 388 } 389 out: 390 release_sock(sk); 391 return rc; 392 } 393 394 EXPORT_SYMBOL_GPL(dccp_ioctl); 395 396 static int dccp_setsockopt_service(struct sock *sk, const __be32 service, 397 char __user *optval, unsigned int optlen) 398 { 399 struct dccp_sock *dp = dccp_sk(sk); 400 struct dccp_service_list *sl = NULL; 401 402 if (service == DCCP_SERVICE_INVALID_VALUE || 403 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) 404 return -EINVAL; 405 406 if (optlen > sizeof(service)) { 407 sl = kmalloc(optlen, GFP_KERNEL); 408 if (sl == NULL) 409 return -ENOMEM; 410 411 sl->dccpsl_nr = optlen / sizeof(u32) - 1; 412 if (copy_from_user(sl->dccpsl_list, 413 optval + sizeof(service), 414 optlen - sizeof(service)) || 415 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { 416 kfree(sl); 417 return -EFAULT; 418 } 419 } 420 421 lock_sock(sk); 422 dp->dccps_service = service; 423 424 kfree(dp->dccps_service_list); 425 426 dp->dccps_service_list = sl; 427 release_sock(sk); 428 return 0; 429 } 430 431 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) 432 { 433 u8 *list, len; 434 int i, rc; 435 436 if (cscov < 0 || cscov > 15) 437 return -EINVAL; 438 /* 439 * Populate a list of permissible values, in the range cscov...15. This 440 * is necessary since feature negotiation of single values only works if 441 * both sides incidentally choose the same value. Since the list starts 442 * lowest-value first, negotiation will pick the smallest shared value. 443 */ 444 if (cscov == 0) 445 return 0; 446 len = 16 - cscov; 447 448 list = kmalloc(len, GFP_KERNEL); 449 if (list == NULL) 450 return -ENOBUFS; 451 452 for (i = 0; i < len; i++) 453 list[i] = cscov++; 454 455 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); 456 457 if (rc == 0) { 458 if (rx) 459 dccp_sk(sk)->dccps_pcrlen = cscov; 460 else 461 dccp_sk(sk)->dccps_pcslen = cscov; 462 } 463 kfree(list); 464 return rc; 465 } 466 467 static int dccp_setsockopt_ccid(struct sock *sk, int type, 468 char __user *optval, unsigned int optlen) 469 { 470 u8 *val; 471 int rc = 0; 472 473 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) 474 return -EINVAL; 475 476 val = memdup_user(optval, optlen); 477 if (IS_ERR(val)) 478 return PTR_ERR(val); 479 480 lock_sock(sk); 481 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) 482 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); 483 484 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) 485 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); 486 release_sock(sk); 487 488 kfree(val); 489 return rc; 490 } 491 492 static int do_dccp_setsockopt(struct sock *sk, int level, int optname, 493 char __user *optval, unsigned int optlen) 494 { 495 struct dccp_sock *dp = dccp_sk(sk); 496 int val, err = 0; 497 498 switch (optname) { 499 case DCCP_SOCKOPT_PACKET_SIZE: 500 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 501 return 0; 502 case DCCP_SOCKOPT_CHANGE_L: 503 case DCCP_SOCKOPT_CHANGE_R: 504 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); 505 return 0; 506 case DCCP_SOCKOPT_CCID: 507 case DCCP_SOCKOPT_RX_CCID: 508 case DCCP_SOCKOPT_TX_CCID: 509 return dccp_setsockopt_ccid(sk, optname, optval, optlen); 510 } 511 512 if (optlen < (int)sizeof(int)) 513 return -EINVAL; 514 515 if (get_user(val, (int __user *)optval)) 516 return -EFAULT; 517 518 if (optname == DCCP_SOCKOPT_SERVICE) 519 return dccp_setsockopt_service(sk, val, optval, optlen); 520 521 lock_sock(sk); 522 switch (optname) { 523 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 524 if (dp->dccps_role != DCCP_ROLE_SERVER) 525 err = -EOPNOTSUPP; 526 else 527 dp->dccps_server_timewait = (val != 0); 528 break; 529 case DCCP_SOCKOPT_SEND_CSCOV: 530 err = dccp_setsockopt_cscov(sk, val, false); 531 break; 532 case DCCP_SOCKOPT_RECV_CSCOV: 533 err = dccp_setsockopt_cscov(sk, val, true); 534 break; 535 default: 536 err = -ENOPROTOOPT; 537 break; 538 } 539 release_sock(sk); 540 541 return err; 542 } 543 544 int dccp_setsockopt(struct sock *sk, int level, int optname, 545 char __user *optval, unsigned int optlen) 546 { 547 if (level != SOL_DCCP) 548 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, 549 optname, optval, 550 optlen); 551 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 552 } 553 554 EXPORT_SYMBOL_GPL(dccp_setsockopt); 555 556 #ifdef CONFIG_COMPAT 557 int compat_dccp_setsockopt(struct sock *sk, int level, int optname, 558 char __user *optval, unsigned int optlen) 559 { 560 if (level != SOL_DCCP) 561 return inet_csk_compat_setsockopt(sk, level, optname, 562 optval, optlen); 563 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 564 } 565 566 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt); 567 #endif 568 569 static int dccp_getsockopt_service(struct sock *sk, int len, 570 __be32 __user *optval, 571 int __user *optlen) 572 { 573 const struct dccp_sock *dp = dccp_sk(sk); 574 const struct dccp_service_list *sl; 575 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 576 577 lock_sock(sk); 578 if ((sl = dp->dccps_service_list) != NULL) { 579 slen = sl->dccpsl_nr * sizeof(u32); 580 total_len += slen; 581 } 582 583 err = -EINVAL; 584 if (total_len > len) 585 goto out; 586 587 err = 0; 588 if (put_user(total_len, optlen) || 589 put_user(dp->dccps_service, optval) || 590 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 591 err = -EFAULT; 592 out: 593 release_sock(sk); 594 return err; 595 } 596 597 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 598 char __user *optval, int __user *optlen) 599 { 600 struct dccp_sock *dp; 601 int val, len; 602 603 if (get_user(len, optlen)) 604 return -EFAULT; 605 606 if (len < (int)sizeof(int)) 607 return -EINVAL; 608 609 dp = dccp_sk(sk); 610 611 switch (optname) { 612 case DCCP_SOCKOPT_PACKET_SIZE: 613 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 614 return 0; 615 case DCCP_SOCKOPT_SERVICE: 616 return dccp_getsockopt_service(sk, len, 617 (__be32 __user *)optval, optlen); 618 case DCCP_SOCKOPT_GET_CUR_MPS: 619 val = dp->dccps_mss_cache; 620 break; 621 case DCCP_SOCKOPT_AVAILABLE_CCIDS: 622 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); 623 case DCCP_SOCKOPT_TX_CCID: 624 val = ccid_get_current_tx_ccid(dp); 625 if (val < 0) 626 return -ENOPROTOOPT; 627 break; 628 case DCCP_SOCKOPT_RX_CCID: 629 val = ccid_get_current_rx_ccid(dp); 630 if (val < 0) 631 return -ENOPROTOOPT; 632 break; 633 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 634 val = dp->dccps_server_timewait; 635 break; 636 case DCCP_SOCKOPT_SEND_CSCOV: 637 val = dp->dccps_pcslen; 638 break; 639 case DCCP_SOCKOPT_RECV_CSCOV: 640 val = dp->dccps_pcrlen; 641 break; 642 case 128 ... 191: 643 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 644 len, (u32 __user *)optval, optlen); 645 case 192 ... 255: 646 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 647 len, (u32 __user *)optval, optlen); 648 default: 649 return -ENOPROTOOPT; 650 } 651 652 len = sizeof(val); 653 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 654 return -EFAULT; 655 656 return 0; 657 } 658 659 int dccp_getsockopt(struct sock *sk, int level, int optname, 660 char __user *optval, int __user *optlen) 661 { 662 if (level != SOL_DCCP) 663 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, 664 optname, optval, 665 optlen); 666 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 667 } 668 669 EXPORT_SYMBOL_GPL(dccp_getsockopt); 670 671 #ifdef CONFIG_COMPAT 672 int compat_dccp_getsockopt(struct sock *sk, int level, int optname, 673 char __user *optval, int __user *optlen) 674 { 675 if (level != SOL_DCCP) 676 return inet_csk_compat_getsockopt(sk, level, optname, 677 optval, optlen); 678 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 679 } 680 681 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); 682 #endif 683 684 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 685 size_t len) 686 { 687 const struct dccp_sock *dp = dccp_sk(sk); 688 const int flags = msg->msg_flags; 689 const int noblock = flags & MSG_DONTWAIT; 690 struct sk_buff *skb; 691 int rc, size; 692 long timeo; 693 694 if (len > dp->dccps_mss_cache) 695 return -EMSGSIZE; 696 697 lock_sock(sk); 698 699 if (sysctl_dccp_tx_qlen && 700 (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) { 701 rc = -EAGAIN; 702 goto out_release; 703 } 704 705 timeo = sock_sndtimeo(sk, noblock); 706 707 /* 708 * We have to use sk_stream_wait_connect here to set sk_write_pending, 709 * so that the trick in dccp_rcv_request_sent_state_process. 710 */ 711 /* Wait for a connection to finish. */ 712 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) 713 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 714 goto out_release; 715 716 size = sk->sk_prot->max_header + len; 717 release_sock(sk); 718 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 719 lock_sock(sk); 720 if (skb == NULL) 721 goto out_release; 722 723 skb_reserve(skb, sk->sk_prot->max_header); 724 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 725 if (rc != 0) 726 goto out_discard; 727 728 skb_queue_tail(&sk->sk_write_queue, skb); 729 /* 730 * The xmit_timer is set if the TX CCID is rate-based and will expire 731 * when congestion control permits to release further packets into the 732 * network. Window-based CCIDs do not use this timer. 733 */ 734 if (!timer_pending(&dp->dccps_xmit_timer)) 735 dccp_write_xmit(sk); 736 out_release: 737 release_sock(sk); 738 return rc ? : len; 739 out_discard: 740 kfree_skb(skb); 741 goto out_release; 742 } 743 744 EXPORT_SYMBOL_GPL(dccp_sendmsg); 745 746 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 747 size_t len, int nonblock, int flags, int *addr_len) 748 { 749 const struct dccp_hdr *dh; 750 long timeo; 751 752 lock_sock(sk); 753 754 if (sk->sk_state == DCCP_LISTEN) { 755 len = -ENOTCONN; 756 goto out; 757 } 758 759 timeo = sock_rcvtimeo(sk, nonblock); 760 761 do { 762 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 763 764 if (skb == NULL) 765 goto verify_sock_status; 766 767 dh = dccp_hdr(skb); 768 769 switch (dh->dccph_type) { 770 case DCCP_PKT_DATA: 771 case DCCP_PKT_DATAACK: 772 goto found_ok_skb; 773 774 case DCCP_PKT_CLOSE: 775 case DCCP_PKT_CLOSEREQ: 776 if (!(flags & MSG_PEEK)) 777 dccp_finish_passive_close(sk); 778 /* fall through */ 779 case DCCP_PKT_RESET: 780 dccp_pr_debug("found fin (%s) ok!\n", 781 dccp_packet_name(dh->dccph_type)); 782 len = 0; 783 goto found_fin_ok; 784 default: 785 dccp_pr_debug("packet_type=%s\n", 786 dccp_packet_name(dh->dccph_type)); 787 sk_eat_skb(sk, skb, 0); 788 } 789 verify_sock_status: 790 if (sock_flag(sk, SOCK_DONE)) { 791 len = 0; 792 break; 793 } 794 795 if (sk->sk_err) { 796 len = sock_error(sk); 797 break; 798 } 799 800 if (sk->sk_shutdown & RCV_SHUTDOWN) { 801 len = 0; 802 break; 803 } 804 805 if (sk->sk_state == DCCP_CLOSED) { 806 if (!sock_flag(sk, SOCK_DONE)) { 807 /* This occurs when user tries to read 808 * from never connected socket. 809 */ 810 len = -ENOTCONN; 811 break; 812 } 813 len = 0; 814 break; 815 } 816 817 if (!timeo) { 818 len = -EAGAIN; 819 break; 820 } 821 822 if (signal_pending(current)) { 823 len = sock_intr_errno(timeo); 824 break; 825 } 826 827 sk_wait_data(sk, &timeo); 828 continue; 829 found_ok_skb: 830 if (len > skb->len) 831 len = skb->len; 832 else if (len < skb->len) 833 msg->msg_flags |= MSG_TRUNC; 834 835 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) { 836 /* Exception. Bailout! */ 837 len = -EFAULT; 838 break; 839 } 840 if (flags & MSG_TRUNC) 841 len = skb->len; 842 found_fin_ok: 843 if (!(flags & MSG_PEEK)) 844 sk_eat_skb(sk, skb, 0); 845 break; 846 } while (1); 847 out: 848 release_sock(sk); 849 return len; 850 } 851 852 EXPORT_SYMBOL_GPL(dccp_recvmsg); 853 854 int inet_dccp_listen(struct socket *sock, int backlog) 855 { 856 struct sock *sk = sock->sk; 857 unsigned char old_state; 858 int err; 859 860 lock_sock(sk); 861 862 err = -EINVAL; 863 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 864 goto out; 865 866 old_state = sk->sk_state; 867 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 868 goto out; 869 870 /* Really, if the socket is already in listen state 871 * we can only allow the backlog to be adjusted. 872 */ 873 if (old_state != DCCP_LISTEN) { 874 /* 875 * FIXME: here it probably should be sk->sk_prot->listen_start 876 * see tcp_listen_start 877 */ 878 err = dccp_listen_start(sk, backlog); 879 if (err) 880 goto out; 881 } 882 sk->sk_max_ack_backlog = backlog; 883 err = 0; 884 885 out: 886 release_sock(sk); 887 return err; 888 } 889 890 EXPORT_SYMBOL_GPL(inet_dccp_listen); 891 892 static void dccp_terminate_connection(struct sock *sk) 893 { 894 u8 next_state = DCCP_CLOSED; 895 896 switch (sk->sk_state) { 897 case DCCP_PASSIVE_CLOSE: 898 case DCCP_PASSIVE_CLOSEREQ: 899 dccp_finish_passive_close(sk); 900 break; 901 case DCCP_PARTOPEN: 902 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); 903 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); 904 /* fall through */ 905 case DCCP_OPEN: 906 dccp_send_close(sk, 1); 907 908 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && 909 !dccp_sk(sk)->dccps_server_timewait) 910 next_state = DCCP_ACTIVE_CLOSEREQ; 911 else 912 next_state = DCCP_CLOSING; 913 /* fall through */ 914 default: 915 dccp_set_state(sk, next_state); 916 } 917 } 918 919 void dccp_close(struct sock *sk, long timeout) 920 { 921 struct dccp_sock *dp = dccp_sk(sk); 922 struct sk_buff *skb; 923 u32 data_was_unread = 0; 924 int state; 925 926 lock_sock(sk); 927 928 sk->sk_shutdown = SHUTDOWN_MASK; 929 930 if (sk->sk_state == DCCP_LISTEN) { 931 dccp_set_state(sk, DCCP_CLOSED); 932 933 /* Special case. */ 934 inet_csk_listen_stop(sk); 935 936 goto adjudge_to_death; 937 } 938 939 sk_stop_timer(sk, &dp->dccps_xmit_timer); 940 941 /* 942 * We need to flush the recv. buffs. We do this only on the 943 * descriptor close, not protocol-sourced closes, because the 944 *reader process may not have drained the data yet! 945 */ 946 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 947 data_was_unread += skb->len; 948 __kfree_skb(skb); 949 } 950 951 if (data_was_unread) { 952 /* Unread data was tossed, send an appropriate Reset Code */ 953 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); 954 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 955 dccp_set_state(sk, DCCP_CLOSED); 956 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 957 /* Check zero linger _after_ checking for unread data. */ 958 sk->sk_prot->disconnect(sk, 0); 959 } else if (sk->sk_state != DCCP_CLOSED) { 960 /* 961 * Normal connection termination. May need to wait if there are 962 * still packets in the TX queue that are delayed by the CCID. 963 */ 964 dccp_flush_write_queue(sk, &timeout); 965 dccp_terminate_connection(sk); 966 } 967 968 /* 969 * Flush write queue. This may be necessary in several cases: 970 * - we have been closed by the peer but still have application data; 971 * - abortive termination (unread data or zero linger time), 972 * - normal termination but queue could not be flushed within time limit 973 */ 974 __skb_queue_purge(&sk->sk_write_queue); 975 976 sk_stream_wait_close(sk, timeout); 977 978 adjudge_to_death: 979 state = sk->sk_state; 980 sock_hold(sk); 981 sock_orphan(sk); 982 983 /* 984 * It is the last release_sock in its life. It will remove backlog. 985 */ 986 release_sock(sk); 987 /* 988 * Now socket is owned by kernel and we acquire BH lock 989 * to finish close. No need to check for user refs. 990 */ 991 local_bh_disable(); 992 bh_lock_sock(sk); 993 WARN_ON(sock_owned_by_user(sk)); 994 995 percpu_counter_inc(sk->sk_prot->orphan_count); 996 997 /* Have we already been destroyed by a softirq or backlog? */ 998 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 999 goto out; 1000 1001 if (sk->sk_state == DCCP_CLOSED) 1002 inet_csk_destroy_sock(sk); 1003 1004 /* Otherwise, socket is reprieved until protocol close. */ 1005 1006 out: 1007 bh_unlock_sock(sk); 1008 local_bh_enable(); 1009 sock_put(sk); 1010 } 1011 1012 EXPORT_SYMBOL_GPL(dccp_close); 1013 1014 void dccp_shutdown(struct sock *sk, int how) 1015 { 1016 dccp_pr_debug("called shutdown(%x)\n", how); 1017 } 1018 1019 EXPORT_SYMBOL_GPL(dccp_shutdown); 1020 1021 static inline int dccp_mib_init(void) 1022 { 1023 return snmp_mib_init((void __percpu **)dccp_statistics, 1024 sizeof(struct dccp_mib), 1025 __alignof__(struct dccp_mib)); 1026 } 1027 1028 static inline void dccp_mib_exit(void) 1029 { 1030 snmp_mib_free((void __percpu **)dccp_statistics); 1031 } 1032 1033 static int thash_entries; 1034 module_param(thash_entries, int, 0444); 1035 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 1036 1037 #ifdef CONFIG_IP_DCCP_DEBUG 1038 int dccp_debug; 1039 module_param(dccp_debug, bool, 0644); 1040 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 1041 1042 EXPORT_SYMBOL_GPL(dccp_debug); 1043 #endif 1044 1045 static int __init dccp_init(void) 1046 { 1047 unsigned long goal; 1048 int ehash_order, bhash_order, i; 1049 int rc; 1050 1051 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > 1052 FIELD_SIZEOF(struct sk_buff, cb)); 1053 rc = percpu_counter_init(&dccp_orphan_count, 0); 1054 if (rc) 1055 goto out_fail; 1056 rc = -ENOBUFS; 1057 inet_hashinfo_init(&dccp_hashinfo); 1058 dccp_hashinfo.bind_bucket_cachep = 1059 kmem_cache_create("dccp_bind_bucket", 1060 sizeof(struct inet_bind_bucket), 0, 1061 SLAB_HWCACHE_ALIGN, NULL); 1062 if (!dccp_hashinfo.bind_bucket_cachep) 1063 goto out_free_percpu; 1064 1065 /* 1066 * Size and allocate the main established and bind bucket 1067 * hash tables. 1068 * 1069 * The methodology is similar to that of the buffer cache. 1070 */ 1071 if (totalram_pages >= (128 * 1024)) 1072 goal = totalram_pages >> (21 - PAGE_SHIFT); 1073 else 1074 goal = totalram_pages >> (23 - PAGE_SHIFT); 1075 1076 if (thash_entries) 1077 goal = (thash_entries * 1078 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1079 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1080 ; 1081 do { 1082 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / 1083 sizeof(struct inet_ehash_bucket); 1084 1085 while (hash_size & (hash_size - 1)) 1086 hash_size--; 1087 dccp_hashinfo.ehash_mask = hash_size - 1; 1088 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1089 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); 1090 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1091 1092 if (!dccp_hashinfo.ehash) { 1093 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1094 goto out_free_bind_bucket_cachep; 1095 } 1096 1097 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) { 1098 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); 1099 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i); 1100 } 1101 1102 if (inet_ehash_locks_alloc(&dccp_hashinfo)) 1103 goto out_free_dccp_ehash; 1104 1105 bhash_order = ehash_order; 1106 1107 do { 1108 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1109 sizeof(struct inet_bind_hashbucket); 1110 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1111 bhash_order > 0) 1112 continue; 1113 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1114 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); 1115 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1116 1117 if (!dccp_hashinfo.bhash) { 1118 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1119 goto out_free_dccp_locks; 1120 } 1121 1122 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1123 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1124 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1125 } 1126 1127 rc = dccp_mib_init(); 1128 if (rc) 1129 goto out_free_dccp_bhash; 1130 1131 rc = dccp_ackvec_init(); 1132 if (rc) 1133 goto out_free_dccp_mib; 1134 1135 rc = dccp_sysctl_init(); 1136 if (rc) 1137 goto out_ackvec_exit; 1138 1139 rc = ccid_initialize_builtins(); 1140 if (rc) 1141 goto out_sysctl_exit; 1142 1143 dccp_timestamping_init(); 1144 1145 return 0; 1146 1147 out_sysctl_exit: 1148 dccp_sysctl_exit(); 1149 out_ackvec_exit: 1150 dccp_ackvec_exit(); 1151 out_free_dccp_mib: 1152 dccp_mib_exit(); 1153 out_free_dccp_bhash: 1154 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1155 out_free_dccp_locks: 1156 inet_ehash_locks_free(&dccp_hashinfo); 1157 out_free_dccp_ehash: 1158 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1159 out_free_bind_bucket_cachep: 1160 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1161 out_free_percpu: 1162 percpu_counter_destroy(&dccp_orphan_count); 1163 out_fail: 1164 dccp_hashinfo.bhash = NULL; 1165 dccp_hashinfo.ehash = NULL; 1166 dccp_hashinfo.bind_bucket_cachep = NULL; 1167 return rc; 1168 } 1169 1170 static void __exit dccp_fini(void) 1171 { 1172 ccid_cleanup_builtins(); 1173 dccp_mib_exit(); 1174 free_pages((unsigned long)dccp_hashinfo.bhash, 1175 get_order(dccp_hashinfo.bhash_size * 1176 sizeof(struct inet_bind_hashbucket))); 1177 free_pages((unsigned long)dccp_hashinfo.ehash, 1178 get_order((dccp_hashinfo.ehash_mask + 1) * 1179 sizeof(struct inet_ehash_bucket))); 1180 inet_ehash_locks_free(&dccp_hashinfo); 1181 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1182 dccp_ackvec_exit(); 1183 dccp_sysctl_exit(); 1184 percpu_counter_destroy(&dccp_orphan_count); 1185 } 1186 1187 module_init(dccp_init); 1188 module_exit(dccp_fini); 1189 1190 MODULE_LICENSE("GPL"); 1191 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1192 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1193