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_tx_qlen = sysctl_dccp_tx_qlen; 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_is_writeable(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_is_writeable(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 case DCCP_SOCKOPT_QPOLICY_ID: 536 if (sk->sk_state != DCCP_CLOSED) 537 err = -EISCONN; 538 else if (val < 0 || val >= DCCPQ_POLICY_MAX) 539 err = -EINVAL; 540 else 541 dp->dccps_qpolicy = val; 542 break; 543 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 544 if (val < 0) 545 err = -EINVAL; 546 else 547 dp->dccps_tx_qlen = val; 548 break; 549 default: 550 err = -ENOPROTOOPT; 551 break; 552 } 553 release_sock(sk); 554 555 return err; 556 } 557 558 int dccp_setsockopt(struct sock *sk, int level, int optname, 559 char __user *optval, unsigned int optlen) 560 { 561 if (level != SOL_DCCP) 562 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, 563 optname, optval, 564 optlen); 565 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 566 } 567 568 EXPORT_SYMBOL_GPL(dccp_setsockopt); 569 570 #ifdef CONFIG_COMPAT 571 int compat_dccp_setsockopt(struct sock *sk, int level, int optname, 572 char __user *optval, unsigned int optlen) 573 { 574 if (level != SOL_DCCP) 575 return inet_csk_compat_setsockopt(sk, level, optname, 576 optval, optlen); 577 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 578 } 579 580 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt); 581 #endif 582 583 static int dccp_getsockopt_service(struct sock *sk, int len, 584 __be32 __user *optval, 585 int __user *optlen) 586 { 587 const struct dccp_sock *dp = dccp_sk(sk); 588 const struct dccp_service_list *sl; 589 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 590 591 lock_sock(sk); 592 if ((sl = dp->dccps_service_list) != NULL) { 593 slen = sl->dccpsl_nr * sizeof(u32); 594 total_len += slen; 595 } 596 597 err = -EINVAL; 598 if (total_len > len) 599 goto out; 600 601 err = 0; 602 if (put_user(total_len, optlen) || 603 put_user(dp->dccps_service, optval) || 604 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 605 err = -EFAULT; 606 out: 607 release_sock(sk); 608 return err; 609 } 610 611 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 612 char __user *optval, int __user *optlen) 613 { 614 struct dccp_sock *dp; 615 int val, len; 616 617 if (get_user(len, optlen)) 618 return -EFAULT; 619 620 if (len < (int)sizeof(int)) 621 return -EINVAL; 622 623 dp = dccp_sk(sk); 624 625 switch (optname) { 626 case DCCP_SOCKOPT_PACKET_SIZE: 627 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 628 return 0; 629 case DCCP_SOCKOPT_SERVICE: 630 return dccp_getsockopt_service(sk, len, 631 (__be32 __user *)optval, optlen); 632 case DCCP_SOCKOPT_GET_CUR_MPS: 633 val = dp->dccps_mss_cache; 634 break; 635 case DCCP_SOCKOPT_AVAILABLE_CCIDS: 636 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); 637 case DCCP_SOCKOPT_TX_CCID: 638 val = ccid_get_current_tx_ccid(dp); 639 if (val < 0) 640 return -ENOPROTOOPT; 641 break; 642 case DCCP_SOCKOPT_RX_CCID: 643 val = ccid_get_current_rx_ccid(dp); 644 if (val < 0) 645 return -ENOPROTOOPT; 646 break; 647 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 648 val = dp->dccps_server_timewait; 649 break; 650 case DCCP_SOCKOPT_SEND_CSCOV: 651 val = dp->dccps_pcslen; 652 break; 653 case DCCP_SOCKOPT_RECV_CSCOV: 654 val = dp->dccps_pcrlen; 655 break; 656 case DCCP_SOCKOPT_QPOLICY_ID: 657 val = dp->dccps_qpolicy; 658 break; 659 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 660 val = dp->dccps_tx_qlen; 661 break; 662 case 128 ... 191: 663 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 664 len, (u32 __user *)optval, optlen); 665 case 192 ... 255: 666 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 667 len, (u32 __user *)optval, optlen); 668 default: 669 return -ENOPROTOOPT; 670 } 671 672 len = sizeof(val); 673 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 674 return -EFAULT; 675 676 return 0; 677 } 678 679 int dccp_getsockopt(struct sock *sk, int level, int optname, 680 char __user *optval, int __user *optlen) 681 { 682 if (level != SOL_DCCP) 683 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, 684 optname, optval, 685 optlen); 686 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 687 } 688 689 EXPORT_SYMBOL_GPL(dccp_getsockopt); 690 691 #ifdef CONFIG_COMPAT 692 int compat_dccp_getsockopt(struct sock *sk, int level, int optname, 693 char __user *optval, int __user *optlen) 694 { 695 if (level != SOL_DCCP) 696 return inet_csk_compat_getsockopt(sk, level, optname, 697 optval, optlen); 698 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 699 } 700 701 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); 702 #endif 703 704 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) 705 { 706 struct cmsghdr *cmsg; 707 708 /* 709 * Assign an (opaque) qpolicy priority value to skb->priority. 710 * 711 * We are overloading this skb field for use with the qpolicy subystem. 712 * The skb->priority is normally used for the SO_PRIORITY option, which 713 * is initialised from sk_priority. Since the assignment of sk_priority 714 * to skb->priority happens later (on layer 3), we overload this field 715 * for use with queueing priorities as long as the skb is on layer 4. 716 * The default priority value (if nothing is set) is 0. 717 */ 718 skb->priority = 0; 719 720 for_each_cmsghdr(cmsg, msg) { 721 if (!CMSG_OK(msg, cmsg)) 722 return -EINVAL; 723 724 if (cmsg->cmsg_level != SOL_DCCP) 725 continue; 726 727 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && 728 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) 729 return -EINVAL; 730 731 switch (cmsg->cmsg_type) { 732 case DCCP_SCM_PRIORITY: 733 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) 734 return -EINVAL; 735 skb->priority = *(__u32 *)CMSG_DATA(cmsg); 736 break; 737 default: 738 return -EINVAL; 739 } 740 } 741 return 0; 742 } 743 744 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 745 { 746 const struct dccp_sock *dp = dccp_sk(sk); 747 const int flags = msg->msg_flags; 748 const int noblock = flags & MSG_DONTWAIT; 749 struct sk_buff *skb; 750 int rc, size; 751 long timeo; 752 753 if (len > dp->dccps_mss_cache) 754 return -EMSGSIZE; 755 756 lock_sock(sk); 757 758 if (dccp_qpolicy_full(sk)) { 759 rc = -EAGAIN; 760 goto out_release; 761 } 762 763 timeo = sock_sndtimeo(sk, noblock); 764 765 /* 766 * We have to use sk_stream_wait_connect here to set sk_write_pending, 767 * so that the trick in dccp_rcv_request_sent_state_process. 768 */ 769 /* Wait for a connection to finish. */ 770 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) 771 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 772 goto out_release; 773 774 size = sk->sk_prot->max_header + len; 775 release_sock(sk); 776 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 777 lock_sock(sk); 778 if (skb == NULL) 779 goto out_release; 780 781 skb_reserve(skb, sk->sk_prot->max_header); 782 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 783 if (rc != 0) 784 goto out_discard; 785 786 rc = dccp_msghdr_parse(msg, skb); 787 if (rc != 0) 788 goto out_discard; 789 790 dccp_qpolicy_push(sk, skb); 791 /* 792 * The xmit_timer is set if the TX CCID is rate-based and will expire 793 * when congestion control permits to release further packets into the 794 * network. Window-based CCIDs do not use this timer. 795 */ 796 if (!timer_pending(&dp->dccps_xmit_timer)) 797 dccp_write_xmit(sk); 798 out_release: 799 release_sock(sk); 800 return rc ? : len; 801 out_discard: 802 kfree_skb(skb); 803 goto out_release; 804 } 805 806 EXPORT_SYMBOL_GPL(dccp_sendmsg); 807 808 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 809 int flags, int *addr_len) 810 { 811 const struct dccp_hdr *dh; 812 long timeo; 813 814 lock_sock(sk); 815 816 if (sk->sk_state == DCCP_LISTEN) { 817 len = -ENOTCONN; 818 goto out; 819 } 820 821 timeo = sock_rcvtimeo(sk, nonblock); 822 823 do { 824 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 825 826 if (skb == NULL) 827 goto verify_sock_status; 828 829 dh = dccp_hdr(skb); 830 831 switch (dh->dccph_type) { 832 case DCCP_PKT_DATA: 833 case DCCP_PKT_DATAACK: 834 goto found_ok_skb; 835 836 case DCCP_PKT_CLOSE: 837 case DCCP_PKT_CLOSEREQ: 838 if (!(flags & MSG_PEEK)) 839 dccp_finish_passive_close(sk); 840 /* fall through */ 841 case DCCP_PKT_RESET: 842 dccp_pr_debug("found fin (%s) ok!\n", 843 dccp_packet_name(dh->dccph_type)); 844 len = 0; 845 goto found_fin_ok; 846 default: 847 dccp_pr_debug("packet_type=%s\n", 848 dccp_packet_name(dh->dccph_type)); 849 sk_eat_skb(sk, skb); 850 } 851 verify_sock_status: 852 if (sock_flag(sk, SOCK_DONE)) { 853 len = 0; 854 break; 855 } 856 857 if (sk->sk_err) { 858 len = sock_error(sk); 859 break; 860 } 861 862 if (sk->sk_shutdown & RCV_SHUTDOWN) { 863 len = 0; 864 break; 865 } 866 867 if (sk->sk_state == DCCP_CLOSED) { 868 if (!sock_flag(sk, SOCK_DONE)) { 869 /* This occurs when user tries to read 870 * from never connected socket. 871 */ 872 len = -ENOTCONN; 873 break; 874 } 875 len = 0; 876 break; 877 } 878 879 if (!timeo) { 880 len = -EAGAIN; 881 break; 882 } 883 884 if (signal_pending(current)) { 885 len = sock_intr_errno(timeo); 886 break; 887 } 888 889 sk_wait_data(sk, &timeo); 890 continue; 891 found_ok_skb: 892 if (len > skb->len) 893 len = skb->len; 894 else if (len < skb->len) 895 msg->msg_flags |= MSG_TRUNC; 896 897 if (skb_copy_datagram_msg(skb, 0, msg, len)) { 898 /* Exception. Bailout! */ 899 len = -EFAULT; 900 break; 901 } 902 if (flags & MSG_TRUNC) 903 len = skb->len; 904 found_fin_ok: 905 if (!(flags & MSG_PEEK)) 906 sk_eat_skb(sk, skb); 907 break; 908 } while (1); 909 out: 910 release_sock(sk); 911 return len; 912 } 913 914 EXPORT_SYMBOL_GPL(dccp_recvmsg); 915 916 int inet_dccp_listen(struct socket *sock, int backlog) 917 { 918 struct sock *sk = sock->sk; 919 unsigned char old_state; 920 int err; 921 922 lock_sock(sk); 923 924 err = -EINVAL; 925 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 926 goto out; 927 928 old_state = sk->sk_state; 929 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 930 goto out; 931 932 /* Really, if the socket is already in listen state 933 * we can only allow the backlog to be adjusted. 934 */ 935 if (old_state != DCCP_LISTEN) { 936 /* 937 * FIXME: here it probably should be sk->sk_prot->listen_start 938 * see tcp_listen_start 939 */ 940 err = dccp_listen_start(sk, backlog); 941 if (err) 942 goto out; 943 } 944 sk->sk_max_ack_backlog = backlog; 945 err = 0; 946 947 out: 948 release_sock(sk); 949 return err; 950 } 951 952 EXPORT_SYMBOL_GPL(inet_dccp_listen); 953 954 static void dccp_terminate_connection(struct sock *sk) 955 { 956 u8 next_state = DCCP_CLOSED; 957 958 switch (sk->sk_state) { 959 case DCCP_PASSIVE_CLOSE: 960 case DCCP_PASSIVE_CLOSEREQ: 961 dccp_finish_passive_close(sk); 962 break; 963 case DCCP_PARTOPEN: 964 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); 965 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); 966 /* fall through */ 967 case DCCP_OPEN: 968 dccp_send_close(sk, 1); 969 970 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && 971 !dccp_sk(sk)->dccps_server_timewait) 972 next_state = DCCP_ACTIVE_CLOSEREQ; 973 else 974 next_state = DCCP_CLOSING; 975 /* fall through */ 976 default: 977 dccp_set_state(sk, next_state); 978 } 979 } 980 981 void dccp_close(struct sock *sk, long timeout) 982 { 983 struct dccp_sock *dp = dccp_sk(sk); 984 struct sk_buff *skb; 985 u32 data_was_unread = 0; 986 int state; 987 988 lock_sock(sk); 989 990 sk->sk_shutdown = SHUTDOWN_MASK; 991 992 if (sk->sk_state == DCCP_LISTEN) { 993 dccp_set_state(sk, DCCP_CLOSED); 994 995 /* Special case. */ 996 inet_csk_listen_stop(sk); 997 998 goto adjudge_to_death; 999 } 1000 1001 sk_stop_timer(sk, &dp->dccps_xmit_timer); 1002 1003 /* 1004 * We need to flush the recv. buffs. We do this only on the 1005 * descriptor close, not protocol-sourced closes, because the 1006 *reader process may not have drained the data yet! 1007 */ 1008 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1009 data_was_unread += skb->len; 1010 __kfree_skb(skb); 1011 } 1012 1013 if (data_was_unread) { 1014 /* Unread data was tossed, send an appropriate Reset Code */ 1015 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); 1016 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 1017 dccp_set_state(sk, DCCP_CLOSED); 1018 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1019 /* Check zero linger _after_ checking for unread data. */ 1020 sk->sk_prot->disconnect(sk, 0); 1021 } else if (sk->sk_state != DCCP_CLOSED) { 1022 /* 1023 * Normal connection termination. May need to wait if there are 1024 * still packets in the TX queue that are delayed by the CCID. 1025 */ 1026 dccp_flush_write_queue(sk, &timeout); 1027 dccp_terminate_connection(sk); 1028 } 1029 1030 /* 1031 * Flush write queue. This may be necessary in several cases: 1032 * - we have been closed by the peer but still have application data; 1033 * - abortive termination (unread data or zero linger time), 1034 * - normal termination but queue could not be flushed within time limit 1035 */ 1036 __skb_queue_purge(&sk->sk_write_queue); 1037 1038 sk_stream_wait_close(sk, timeout); 1039 1040 adjudge_to_death: 1041 state = sk->sk_state; 1042 sock_hold(sk); 1043 sock_orphan(sk); 1044 1045 /* 1046 * It is the last release_sock in its life. It will remove backlog. 1047 */ 1048 release_sock(sk); 1049 /* 1050 * Now socket is owned by kernel and we acquire BH lock 1051 * to finish close. No need to check for user refs. 1052 */ 1053 local_bh_disable(); 1054 bh_lock_sock(sk); 1055 WARN_ON(sock_owned_by_user(sk)); 1056 1057 percpu_counter_inc(sk->sk_prot->orphan_count); 1058 1059 /* Have we already been destroyed by a softirq or backlog? */ 1060 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 1061 goto out; 1062 1063 if (sk->sk_state == DCCP_CLOSED) 1064 inet_csk_destroy_sock(sk); 1065 1066 /* Otherwise, socket is reprieved until protocol close. */ 1067 1068 out: 1069 bh_unlock_sock(sk); 1070 local_bh_enable(); 1071 sock_put(sk); 1072 } 1073 1074 EXPORT_SYMBOL_GPL(dccp_close); 1075 1076 void dccp_shutdown(struct sock *sk, int how) 1077 { 1078 dccp_pr_debug("called shutdown(%x)\n", how); 1079 } 1080 1081 EXPORT_SYMBOL_GPL(dccp_shutdown); 1082 1083 static inline int __init dccp_mib_init(void) 1084 { 1085 dccp_statistics = alloc_percpu(struct dccp_mib); 1086 if (!dccp_statistics) 1087 return -ENOMEM; 1088 return 0; 1089 } 1090 1091 static inline void dccp_mib_exit(void) 1092 { 1093 free_percpu(dccp_statistics); 1094 } 1095 1096 static int thash_entries; 1097 module_param(thash_entries, int, 0444); 1098 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 1099 1100 #ifdef CONFIG_IP_DCCP_DEBUG 1101 bool dccp_debug; 1102 module_param(dccp_debug, bool, 0644); 1103 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 1104 1105 EXPORT_SYMBOL_GPL(dccp_debug); 1106 #endif 1107 1108 static int __init dccp_init(void) 1109 { 1110 unsigned long goal; 1111 int ehash_order, bhash_order, i; 1112 int rc; 1113 1114 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > 1115 FIELD_SIZEOF(struct sk_buff, cb)); 1116 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL); 1117 if (rc) 1118 goto out_fail; 1119 rc = -ENOBUFS; 1120 inet_hashinfo_init(&dccp_hashinfo); 1121 dccp_hashinfo.bind_bucket_cachep = 1122 kmem_cache_create("dccp_bind_bucket", 1123 sizeof(struct inet_bind_bucket), 0, 1124 SLAB_HWCACHE_ALIGN, NULL); 1125 if (!dccp_hashinfo.bind_bucket_cachep) 1126 goto out_free_percpu; 1127 1128 /* 1129 * Size and allocate the main established and bind bucket 1130 * hash tables. 1131 * 1132 * The methodology is similar to that of the buffer cache. 1133 */ 1134 if (totalram_pages >= (128 * 1024)) 1135 goal = totalram_pages >> (21 - PAGE_SHIFT); 1136 else 1137 goal = totalram_pages >> (23 - PAGE_SHIFT); 1138 1139 if (thash_entries) 1140 goal = (thash_entries * 1141 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1142 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1143 ; 1144 do { 1145 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / 1146 sizeof(struct inet_ehash_bucket); 1147 1148 while (hash_size & (hash_size - 1)) 1149 hash_size--; 1150 dccp_hashinfo.ehash_mask = hash_size - 1; 1151 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1152 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); 1153 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1154 1155 if (!dccp_hashinfo.ehash) { 1156 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1157 goto out_free_bind_bucket_cachep; 1158 } 1159 1160 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) 1161 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); 1162 1163 if (inet_ehash_locks_alloc(&dccp_hashinfo)) 1164 goto out_free_dccp_ehash; 1165 1166 bhash_order = ehash_order; 1167 1168 do { 1169 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1170 sizeof(struct inet_bind_hashbucket); 1171 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1172 bhash_order > 0) 1173 continue; 1174 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1175 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); 1176 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1177 1178 if (!dccp_hashinfo.bhash) { 1179 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1180 goto out_free_dccp_locks; 1181 } 1182 1183 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1184 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1185 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1186 } 1187 1188 rc = dccp_mib_init(); 1189 if (rc) 1190 goto out_free_dccp_bhash; 1191 1192 rc = dccp_ackvec_init(); 1193 if (rc) 1194 goto out_free_dccp_mib; 1195 1196 rc = dccp_sysctl_init(); 1197 if (rc) 1198 goto out_ackvec_exit; 1199 1200 rc = ccid_initialize_builtins(); 1201 if (rc) 1202 goto out_sysctl_exit; 1203 1204 dccp_timestamping_init(); 1205 1206 return 0; 1207 1208 out_sysctl_exit: 1209 dccp_sysctl_exit(); 1210 out_ackvec_exit: 1211 dccp_ackvec_exit(); 1212 out_free_dccp_mib: 1213 dccp_mib_exit(); 1214 out_free_dccp_bhash: 1215 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1216 out_free_dccp_locks: 1217 inet_ehash_locks_free(&dccp_hashinfo); 1218 out_free_dccp_ehash: 1219 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1220 out_free_bind_bucket_cachep: 1221 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1222 out_free_percpu: 1223 percpu_counter_destroy(&dccp_orphan_count); 1224 out_fail: 1225 dccp_hashinfo.bhash = NULL; 1226 dccp_hashinfo.ehash = NULL; 1227 dccp_hashinfo.bind_bucket_cachep = NULL; 1228 return rc; 1229 } 1230 1231 static void __exit dccp_fini(void) 1232 { 1233 ccid_cleanup_builtins(); 1234 dccp_mib_exit(); 1235 free_pages((unsigned long)dccp_hashinfo.bhash, 1236 get_order(dccp_hashinfo.bhash_size * 1237 sizeof(struct inet_bind_hashbucket))); 1238 free_pages((unsigned long)dccp_hashinfo.ehash, 1239 get_order((dccp_hashinfo.ehash_mask + 1) * 1240 sizeof(struct inet_ehash_bucket))); 1241 inet_ehash_locks_free(&dccp_hashinfo); 1242 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1243 dccp_ackvec_exit(); 1244 dccp_sysctl_exit(); 1245 percpu_counter_destroy(&dccp_orphan_count); 1246 } 1247 1248 module_init(dccp_init); 1249 module_exit(dccp_fini); 1250 1251 MODULE_LICENSE("GPL"); 1252 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1253 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1254