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 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 343 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 344 345 /* Race breaker. If space is freed after 346 * wspace test but before the flags are set, 347 * IO signal will be lost. 348 */ 349 if (sk_stream_is_writeable(sk)) 350 mask |= POLLOUT | POLLWRNORM; 351 } 352 } 353 } 354 return mask; 355 } 356 357 EXPORT_SYMBOL_GPL(dccp_poll); 358 359 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) 360 { 361 int rc = -ENOTCONN; 362 363 lock_sock(sk); 364 365 if (sk->sk_state == DCCP_LISTEN) 366 goto out; 367 368 switch (cmd) { 369 case SIOCINQ: { 370 struct sk_buff *skb; 371 unsigned long amount = 0; 372 373 skb = skb_peek(&sk->sk_receive_queue); 374 if (skb != NULL) { 375 /* 376 * We will only return the amount of this packet since 377 * that is all that will be read. 378 */ 379 amount = skb->len; 380 } 381 rc = put_user(amount, (int __user *)arg); 382 } 383 break; 384 default: 385 rc = -ENOIOCTLCMD; 386 break; 387 } 388 out: 389 release_sock(sk); 390 return rc; 391 } 392 393 EXPORT_SYMBOL_GPL(dccp_ioctl); 394 395 static int dccp_setsockopt_service(struct sock *sk, const __be32 service, 396 char __user *optval, unsigned int optlen) 397 { 398 struct dccp_sock *dp = dccp_sk(sk); 399 struct dccp_service_list *sl = NULL; 400 401 if (service == DCCP_SERVICE_INVALID_VALUE || 402 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) 403 return -EINVAL; 404 405 if (optlen > sizeof(service)) { 406 sl = kmalloc(optlen, GFP_KERNEL); 407 if (sl == NULL) 408 return -ENOMEM; 409 410 sl->dccpsl_nr = optlen / sizeof(u32) - 1; 411 if (copy_from_user(sl->dccpsl_list, 412 optval + sizeof(service), 413 optlen - sizeof(service)) || 414 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { 415 kfree(sl); 416 return -EFAULT; 417 } 418 } 419 420 lock_sock(sk); 421 dp->dccps_service = service; 422 423 kfree(dp->dccps_service_list); 424 425 dp->dccps_service_list = sl; 426 release_sock(sk); 427 return 0; 428 } 429 430 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) 431 { 432 u8 *list, len; 433 int i, rc; 434 435 if (cscov < 0 || cscov > 15) 436 return -EINVAL; 437 /* 438 * Populate a list of permissible values, in the range cscov...15. This 439 * is necessary since feature negotiation of single values only works if 440 * both sides incidentally choose the same value. Since the list starts 441 * lowest-value first, negotiation will pick the smallest shared value. 442 */ 443 if (cscov == 0) 444 return 0; 445 len = 16 - cscov; 446 447 list = kmalloc(len, GFP_KERNEL); 448 if (list == NULL) 449 return -ENOBUFS; 450 451 for (i = 0; i < len; i++) 452 list[i] = cscov++; 453 454 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); 455 456 if (rc == 0) { 457 if (rx) 458 dccp_sk(sk)->dccps_pcrlen = cscov; 459 else 460 dccp_sk(sk)->dccps_pcslen = cscov; 461 } 462 kfree(list); 463 return rc; 464 } 465 466 static int dccp_setsockopt_ccid(struct sock *sk, int type, 467 char __user *optval, unsigned int optlen) 468 { 469 u8 *val; 470 int rc = 0; 471 472 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) 473 return -EINVAL; 474 475 val = memdup_user(optval, optlen); 476 if (IS_ERR(val)) 477 return PTR_ERR(val); 478 479 lock_sock(sk); 480 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) 481 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); 482 483 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) 484 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); 485 release_sock(sk); 486 487 kfree(val); 488 return rc; 489 } 490 491 static int do_dccp_setsockopt(struct sock *sk, int level, int optname, 492 char __user *optval, unsigned int optlen) 493 { 494 struct dccp_sock *dp = dccp_sk(sk); 495 int val, err = 0; 496 497 switch (optname) { 498 case DCCP_SOCKOPT_PACKET_SIZE: 499 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 500 return 0; 501 case DCCP_SOCKOPT_CHANGE_L: 502 case DCCP_SOCKOPT_CHANGE_R: 503 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); 504 return 0; 505 case DCCP_SOCKOPT_CCID: 506 case DCCP_SOCKOPT_RX_CCID: 507 case DCCP_SOCKOPT_TX_CCID: 508 return dccp_setsockopt_ccid(sk, optname, optval, optlen); 509 } 510 511 if (optlen < (int)sizeof(int)) 512 return -EINVAL; 513 514 if (get_user(val, (int __user *)optval)) 515 return -EFAULT; 516 517 if (optname == DCCP_SOCKOPT_SERVICE) 518 return dccp_setsockopt_service(sk, val, optval, optlen); 519 520 lock_sock(sk); 521 switch (optname) { 522 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 523 if (dp->dccps_role != DCCP_ROLE_SERVER) 524 err = -EOPNOTSUPP; 525 else 526 dp->dccps_server_timewait = (val != 0); 527 break; 528 case DCCP_SOCKOPT_SEND_CSCOV: 529 err = dccp_setsockopt_cscov(sk, val, false); 530 break; 531 case DCCP_SOCKOPT_RECV_CSCOV: 532 err = dccp_setsockopt_cscov(sk, val, true); 533 break; 534 case DCCP_SOCKOPT_QPOLICY_ID: 535 if (sk->sk_state != DCCP_CLOSED) 536 err = -EISCONN; 537 else if (val < 0 || val >= DCCPQ_POLICY_MAX) 538 err = -EINVAL; 539 else 540 dp->dccps_qpolicy = val; 541 break; 542 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 543 if (val < 0) 544 err = -EINVAL; 545 else 546 dp->dccps_tx_qlen = val; 547 break; 548 default: 549 err = -ENOPROTOOPT; 550 break; 551 } 552 release_sock(sk); 553 554 return err; 555 } 556 557 int 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(sk)->icsk_af_ops->setsockopt(sk, level, 562 optname, optval, 563 optlen); 564 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 565 } 566 567 EXPORT_SYMBOL_GPL(dccp_setsockopt); 568 569 #ifdef CONFIG_COMPAT 570 int compat_dccp_setsockopt(struct sock *sk, int level, int optname, 571 char __user *optval, unsigned int optlen) 572 { 573 if (level != SOL_DCCP) 574 return inet_csk_compat_setsockopt(sk, level, optname, 575 optval, optlen); 576 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 577 } 578 579 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt); 580 #endif 581 582 static int dccp_getsockopt_service(struct sock *sk, int len, 583 __be32 __user *optval, 584 int __user *optlen) 585 { 586 const struct dccp_sock *dp = dccp_sk(sk); 587 const struct dccp_service_list *sl; 588 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 589 590 lock_sock(sk); 591 if ((sl = dp->dccps_service_list) != NULL) { 592 slen = sl->dccpsl_nr * sizeof(u32); 593 total_len += slen; 594 } 595 596 err = -EINVAL; 597 if (total_len > len) 598 goto out; 599 600 err = 0; 601 if (put_user(total_len, optlen) || 602 put_user(dp->dccps_service, optval) || 603 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 604 err = -EFAULT; 605 out: 606 release_sock(sk); 607 return err; 608 } 609 610 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 611 char __user *optval, int __user *optlen) 612 { 613 struct dccp_sock *dp; 614 int val, len; 615 616 if (get_user(len, optlen)) 617 return -EFAULT; 618 619 if (len < (int)sizeof(int)) 620 return -EINVAL; 621 622 dp = dccp_sk(sk); 623 624 switch (optname) { 625 case DCCP_SOCKOPT_PACKET_SIZE: 626 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 627 return 0; 628 case DCCP_SOCKOPT_SERVICE: 629 return dccp_getsockopt_service(sk, len, 630 (__be32 __user *)optval, optlen); 631 case DCCP_SOCKOPT_GET_CUR_MPS: 632 val = dp->dccps_mss_cache; 633 break; 634 case DCCP_SOCKOPT_AVAILABLE_CCIDS: 635 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); 636 case DCCP_SOCKOPT_TX_CCID: 637 val = ccid_get_current_tx_ccid(dp); 638 if (val < 0) 639 return -ENOPROTOOPT; 640 break; 641 case DCCP_SOCKOPT_RX_CCID: 642 val = ccid_get_current_rx_ccid(dp); 643 if (val < 0) 644 return -ENOPROTOOPT; 645 break; 646 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 647 val = dp->dccps_server_timewait; 648 break; 649 case DCCP_SOCKOPT_SEND_CSCOV: 650 val = dp->dccps_pcslen; 651 break; 652 case DCCP_SOCKOPT_RECV_CSCOV: 653 val = dp->dccps_pcrlen; 654 break; 655 case DCCP_SOCKOPT_QPOLICY_ID: 656 val = dp->dccps_qpolicy; 657 break; 658 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 659 val = dp->dccps_tx_qlen; 660 break; 661 case 128 ... 191: 662 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 663 len, (u32 __user *)optval, optlen); 664 case 192 ... 255: 665 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 666 len, (u32 __user *)optval, optlen); 667 default: 668 return -ENOPROTOOPT; 669 } 670 671 len = sizeof(val); 672 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 673 return -EFAULT; 674 675 return 0; 676 } 677 678 int dccp_getsockopt(struct sock *sk, int level, int optname, 679 char __user *optval, int __user *optlen) 680 { 681 if (level != SOL_DCCP) 682 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, 683 optname, optval, 684 optlen); 685 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 686 } 687 688 EXPORT_SYMBOL_GPL(dccp_getsockopt); 689 690 #ifdef CONFIG_COMPAT 691 int compat_dccp_getsockopt(struct sock *sk, int level, int optname, 692 char __user *optval, int __user *optlen) 693 { 694 if (level != SOL_DCCP) 695 return inet_csk_compat_getsockopt(sk, level, optname, 696 optval, optlen); 697 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 698 } 699 700 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); 701 #endif 702 703 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) 704 { 705 struct cmsghdr *cmsg; 706 707 /* 708 * Assign an (opaque) qpolicy priority value to skb->priority. 709 * 710 * We are overloading this skb field for use with the qpolicy subystem. 711 * The skb->priority is normally used for the SO_PRIORITY option, which 712 * is initialised from sk_priority. Since the assignment of sk_priority 713 * to skb->priority happens later (on layer 3), we overload this field 714 * for use with queueing priorities as long as the skb is on layer 4. 715 * The default priority value (if nothing is set) is 0. 716 */ 717 skb->priority = 0; 718 719 for_each_cmsghdr(cmsg, msg) { 720 if (!CMSG_OK(msg, cmsg)) 721 return -EINVAL; 722 723 if (cmsg->cmsg_level != SOL_DCCP) 724 continue; 725 726 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && 727 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) 728 return -EINVAL; 729 730 switch (cmsg->cmsg_type) { 731 case DCCP_SCM_PRIORITY: 732 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) 733 return -EINVAL; 734 skb->priority = *(__u32 *)CMSG_DATA(cmsg); 735 break; 736 default: 737 return -EINVAL; 738 } 739 } 740 return 0; 741 } 742 743 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 744 { 745 const struct dccp_sock *dp = dccp_sk(sk); 746 const int flags = msg->msg_flags; 747 const int noblock = flags & MSG_DONTWAIT; 748 struct sk_buff *skb; 749 int rc, size; 750 long timeo; 751 752 if (len > dp->dccps_mss_cache) 753 return -EMSGSIZE; 754 755 lock_sock(sk); 756 757 if (dccp_qpolicy_full(sk)) { 758 rc = -EAGAIN; 759 goto out_release; 760 } 761 762 timeo = sock_sndtimeo(sk, noblock); 763 764 /* 765 * We have to use sk_stream_wait_connect here to set sk_write_pending, 766 * so that the trick in dccp_rcv_request_sent_state_process. 767 */ 768 /* Wait for a connection to finish. */ 769 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) 770 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 771 goto out_release; 772 773 size = sk->sk_prot->max_header + len; 774 release_sock(sk); 775 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 776 lock_sock(sk); 777 if (skb == NULL) 778 goto out_release; 779 780 skb_reserve(skb, sk->sk_prot->max_header); 781 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 782 if (rc != 0) 783 goto out_discard; 784 785 rc = dccp_msghdr_parse(msg, skb); 786 if (rc != 0) 787 goto out_discard; 788 789 dccp_qpolicy_push(sk, skb); 790 /* 791 * The xmit_timer is set if the TX CCID is rate-based and will expire 792 * when congestion control permits to release further packets into the 793 * network. Window-based CCIDs do not use this timer. 794 */ 795 if (!timer_pending(&dp->dccps_xmit_timer)) 796 dccp_write_xmit(sk); 797 out_release: 798 release_sock(sk); 799 return rc ? : len; 800 out_discard: 801 kfree_skb(skb); 802 goto out_release; 803 } 804 805 EXPORT_SYMBOL_GPL(dccp_sendmsg); 806 807 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 808 int flags, int *addr_len) 809 { 810 const struct dccp_hdr *dh; 811 long timeo; 812 813 lock_sock(sk); 814 815 if (sk->sk_state == DCCP_LISTEN) { 816 len = -ENOTCONN; 817 goto out; 818 } 819 820 timeo = sock_rcvtimeo(sk, nonblock); 821 822 do { 823 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 824 825 if (skb == NULL) 826 goto verify_sock_status; 827 828 dh = dccp_hdr(skb); 829 830 switch (dh->dccph_type) { 831 case DCCP_PKT_DATA: 832 case DCCP_PKT_DATAACK: 833 goto found_ok_skb; 834 835 case DCCP_PKT_CLOSE: 836 case DCCP_PKT_CLOSEREQ: 837 if (!(flags & MSG_PEEK)) 838 dccp_finish_passive_close(sk); 839 /* fall through */ 840 case DCCP_PKT_RESET: 841 dccp_pr_debug("found fin (%s) ok!\n", 842 dccp_packet_name(dh->dccph_type)); 843 len = 0; 844 goto found_fin_ok; 845 default: 846 dccp_pr_debug("packet_type=%s\n", 847 dccp_packet_name(dh->dccph_type)); 848 sk_eat_skb(sk, skb); 849 } 850 verify_sock_status: 851 if (sock_flag(sk, SOCK_DONE)) { 852 len = 0; 853 break; 854 } 855 856 if (sk->sk_err) { 857 len = sock_error(sk); 858 break; 859 } 860 861 if (sk->sk_shutdown & RCV_SHUTDOWN) { 862 len = 0; 863 break; 864 } 865 866 if (sk->sk_state == DCCP_CLOSED) { 867 if (!sock_flag(sk, SOCK_DONE)) { 868 /* This occurs when user tries to read 869 * from never connected socket. 870 */ 871 len = -ENOTCONN; 872 break; 873 } 874 len = 0; 875 break; 876 } 877 878 if (!timeo) { 879 len = -EAGAIN; 880 break; 881 } 882 883 if (signal_pending(current)) { 884 len = sock_intr_errno(timeo); 885 break; 886 } 887 888 sk_wait_data(sk, &timeo, NULL); 889 continue; 890 found_ok_skb: 891 if (len > skb->len) 892 len = skb->len; 893 else if (len < skb->len) 894 msg->msg_flags |= MSG_TRUNC; 895 896 if (skb_copy_datagram_msg(skb, 0, msg, len)) { 897 /* Exception. Bailout! */ 898 len = -EFAULT; 899 break; 900 } 901 if (flags & MSG_TRUNC) 902 len = skb->len; 903 found_fin_ok: 904 if (!(flags & MSG_PEEK)) 905 sk_eat_skb(sk, skb); 906 break; 907 } while (1); 908 out: 909 release_sock(sk); 910 return len; 911 } 912 913 EXPORT_SYMBOL_GPL(dccp_recvmsg); 914 915 int inet_dccp_listen(struct socket *sock, int backlog) 916 { 917 struct sock *sk = sock->sk; 918 unsigned char old_state; 919 int err; 920 921 lock_sock(sk); 922 923 err = -EINVAL; 924 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 925 goto out; 926 927 old_state = sk->sk_state; 928 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 929 goto out; 930 931 /* Really, if the socket is already in listen state 932 * we can only allow the backlog to be adjusted. 933 */ 934 if (old_state != DCCP_LISTEN) { 935 /* 936 * FIXME: here it probably should be sk->sk_prot->listen_start 937 * see tcp_listen_start 938 */ 939 err = dccp_listen_start(sk, backlog); 940 if (err) 941 goto out; 942 } 943 sk->sk_max_ack_backlog = backlog; 944 err = 0; 945 946 out: 947 release_sock(sk); 948 return err; 949 } 950 951 EXPORT_SYMBOL_GPL(inet_dccp_listen); 952 953 static void dccp_terminate_connection(struct sock *sk) 954 { 955 u8 next_state = DCCP_CLOSED; 956 957 switch (sk->sk_state) { 958 case DCCP_PASSIVE_CLOSE: 959 case DCCP_PASSIVE_CLOSEREQ: 960 dccp_finish_passive_close(sk); 961 break; 962 case DCCP_PARTOPEN: 963 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); 964 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); 965 /* fall through */ 966 case DCCP_OPEN: 967 dccp_send_close(sk, 1); 968 969 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && 970 !dccp_sk(sk)->dccps_server_timewait) 971 next_state = DCCP_ACTIVE_CLOSEREQ; 972 else 973 next_state = DCCP_CLOSING; 974 /* fall through */ 975 default: 976 dccp_set_state(sk, next_state); 977 } 978 } 979 980 void dccp_close(struct sock *sk, long timeout) 981 { 982 struct dccp_sock *dp = dccp_sk(sk); 983 struct sk_buff *skb; 984 u32 data_was_unread = 0; 985 int state; 986 987 lock_sock(sk); 988 989 sk->sk_shutdown = SHUTDOWN_MASK; 990 991 if (sk->sk_state == DCCP_LISTEN) { 992 dccp_set_state(sk, DCCP_CLOSED); 993 994 /* Special case. */ 995 inet_csk_listen_stop(sk); 996 997 goto adjudge_to_death; 998 } 999 1000 sk_stop_timer(sk, &dp->dccps_xmit_timer); 1001 1002 /* 1003 * We need to flush the recv. buffs. We do this only on the 1004 * descriptor close, not protocol-sourced closes, because the 1005 *reader process may not have drained the data yet! 1006 */ 1007 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1008 data_was_unread += skb->len; 1009 __kfree_skb(skb); 1010 } 1011 1012 /* If socket has been already reset kill it. */ 1013 if (sk->sk_state == DCCP_CLOSED) 1014 goto adjudge_to_death; 1015 1016 if (data_was_unread) { 1017 /* Unread data was tossed, send an appropriate Reset Code */ 1018 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); 1019 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 1020 dccp_set_state(sk, DCCP_CLOSED); 1021 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1022 /* Check zero linger _after_ checking for unread data. */ 1023 sk->sk_prot->disconnect(sk, 0); 1024 } else if (sk->sk_state != DCCP_CLOSED) { 1025 /* 1026 * Normal connection termination. May need to wait if there are 1027 * still packets in the TX queue that are delayed by the CCID. 1028 */ 1029 dccp_flush_write_queue(sk, &timeout); 1030 dccp_terminate_connection(sk); 1031 } 1032 1033 /* 1034 * Flush write queue. This may be necessary in several cases: 1035 * - we have been closed by the peer but still have application data; 1036 * - abortive termination (unread data or zero linger time), 1037 * - normal termination but queue could not be flushed within time limit 1038 */ 1039 __skb_queue_purge(&sk->sk_write_queue); 1040 1041 sk_stream_wait_close(sk, timeout); 1042 1043 adjudge_to_death: 1044 state = sk->sk_state; 1045 sock_hold(sk); 1046 sock_orphan(sk); 1047 1048 /* 1049 * It is the last release_sock in its life. It will remove backlog. 1050 */ 1051 release_sock(sk); 1052 /* 1053 * Now socket is owned by kernel and we acquire BH lock 1054 * to finish close. No need to check for user refs. 1055 */ 1056 local_bh_disable(); 1057 bh_lock_sock(sk); 1058 WARN_ON(sock_owned_by_user(sk)); 1059 1060 percpu_counter_inc(sk->sk_prot->orphan_count); 1061 1062 /* Have we already been destroyed by a softirq or backlog? */ 1063 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 1064 goto out; 1065 1066 if (sk->sk_state == DCCP_CLOSED) 1067 inet_csk_destroy_sock(sk); 1068 1069 /* Otherwise, socket is reprieved until protocol close. */ 1070 1071 out: 1072 bh_unlock_sock(sk); 1073 local_bh_enable(); 1074 sock_put(sk); 1075 } 1076 1077 EXPORT_SYMBOL_GPL(dccp_close); 1078 1079 void dccp_shutdown(struct sock *sk, int how) 1080 { 1081 dccp_pr_debug("called shutdown(%x)\n", how); 1082 } 1083 1084 EXPORT_SYMBOL_GPL(dccp_shutdown); 1085 1086 static inline int __init dccp_mib_init(void) 1087 { 1088 dccp_statistics = alloc_percpu(struct dccp_mib); 1089 if (!dccp_statistics) 1090 return -ENOMEM; 1091 return 0; 1092 } 1093 1094 static inline void dccp_mib_exit(void) 1095 { 1096 free_percpu(dccp_statistics); 1097 } 1098 1099 static int thash_entries; 1100 module_param(thash_entries, int, 0444); 1101 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 1102 1103 #ifdef CONFIG_IP_DCCP_DEBUG 1104 bool dccp_debug; 1105 module_param(dccp_debug, bool, 0644); 1106 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 1107 1108 EXPORT_SYMBOL_GPL(dccp_debug); 1109 #endif 1110 1111 static int __init dccp_init(void) 1112 { 1113 unsigned long goal; 1114 int ehash_order, bhash_order, i; 1115 int rc; 1116 1117 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > 1118 FIELD_SIZEOF(struct sk_buff, cb)); 1119 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL); 1120 if (rc) 1121 goto out_fail; 1122 rc = -ENOBUFS; 1123 inet_hashinfo_init(&dccp_hashinfo); 1124 dccp_hashinfo.bind_bucket_cachep = 1125 kmem_cache_create("dccp_bind_bucket", 1126 sizeof(struct inet_bind_bucket), 0, 1127 SLAB_HWCACHE_ALIGN, NULL); 1128 if (!dccp_hashinfo.bind_bucket_cachep) 1129 goto out_free_percpu; 1130 1131 /* 1132 * Size and allocate the main established and bind bucket 1133 * hash tables. 1134 * 1135 * The methodology is similar to that of the buffer cache. 1136 */ 1137 if (totalram_pages >= (128 * 1024)) 1138 goal = totalram_pages >> (21 - PAGE_SHIFT); 1139 else 1140 goal = totalram_pages >> (23 - PAGE_SHIFT); 1141 1142 if (thash_entries) 1143 goal = (thash_entries * 1144 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1145 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1146 ; 1147 do { 1148 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / 1149 sizeof(struct inet_ehash_bucket); 1150 1151 while (hash_size & (hash_size - 1)) 1152 hash_size--; 1153 dccp_hashinfo.ehash_mask = hash_size - 1; 1154 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1155 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); 1156 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1157 1158 if (!dccp_hashinfo.ehash) { 1159 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1160 goto out_free_bind_bucket_cachep; 1161 } 1162 1163 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) 1164 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); 1165 1166 if (inet_ehash_locks_alloc(&dccp_hashinfo)) 1167 goto out_free_dccp_ehash; 1168 1169 bhash_order = ehash_order; 1170 1171 do { 1172 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1173 sizeof(struct inet_bind_hashbucket); 1174 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1175 bhash_order > 0) 1176 continue; 1177 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1178 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); 1179 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1180 1181 if (!dccp_hashinfo.bhash) { 1182 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1183 goto out_free_dccp_locks; 1184 } 1185 1186 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1187 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1188 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1189 } 1190 1191 rc = dccp_mib_init(); 1192 if (rc) 1193 goto out_free_dccp_bhash; 1194 1195 rc = dccp_ackvec_init(); 1196 if (rc) 1197 goto out_free_dccp_mib; 1198 1199 rc = dccp_sysctl_init(); 1200 if (rc) 1201 goto out_ackvec_exit; 1202 1203 rc = ccid_initialize_builtins(); 1204 if (rc) 1205 goto out_sysctl_exit; 1206 1207 dccp_timestamping_init(); 1208 1209 return 0; 1210 1211 out_sysctl_exit: 1212 dccp_sysctl_exit(); 1213 out_ackvec_exit: 1214 dccp_ackvec_exit(); 1215 out_free_dccp_mib: 1216 dccp_mib_exit(); 1217 out_free_dccp_bhash: 1218 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1219 out_free_dccp_locks: 1220 inet_ehash_locks_free(&dccp_hashinfo); 1221 out_free_dccp_ehash: 1222 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1223 out_free_bind_bucket_cachep: 1224 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1225 out_free_percpu: 1226 percpu_counter_destroy(&dccp_orphan_count); 1227 out_fail: 1228 dccp_hashinfo.bhash = NULL; 1229 dccp_hashinfo.ehash = NULL; 1230 dccp_hashinfo.bind_bucket_cachep = NULL; 1231 return rc; 1232 } 1233 1234 static void __exit dccp_fini(void) 1235 { 1236 ccid_cleanup_builtins(); 1237 dccp_mib_exit(); 1238 free_pages((unsigned long)dccp_hashinfo.bhash, 1239 get_order(dccp_hashinfo.bhash_size * 1240 sizeof(struct inet_bind_hashbucket))); 1241 free_pages((unsigned long)dccp_hashinfo.ehash, 1242 get_order((dccp_hashinfo.ehash_mask + 1) * 1243 sizeof(struct inet_ehash_bucket))); 1244 inet_ehash_locks_free(&dccp_hashinfo); 1245 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1246 dccp_ackvec_exit(); 1247 dccp_sysctl_exit(); 1248 percpu_counter_destroy(&dccp_orphan_count); 1249 } 1250 1251 module_init(dccp_init); 1252 module_exit(dccp_fini); 1253 1254 MODULE_LICENSE("GPL"); 1255 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1256 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1257