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/inet_common.h> 28 #include <net/sock.h> 29 #include <net/xfrm.h> 30 31 #include <asm/ioctls.h> 32 #include <linux/spinlock.h> 33 #include <linux/timer.h> 34 #include <linux/delay.h> 35 #include <linux/poll.h> 36 37 #include "ccid.h" 38 #include "dccp.h" 39 #include "feat.h" 40 41 #define CREATE_TRACE_POINTS 42 #include "trace.h" 43 44 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; 45 46 EXPORT_SYMBOL_GPL(dccp_statistics); 47 48 struct percpu_counter dccp_orphan_count; 49 EXPORT_SYMBOL_GPL(dccp_orphan_count); 50 51 struct inet_hashinfo dccp_hashinfo; 52 EXPORT_SYMBOL_GPL(dccp_hashinfo); 53 54 /* the maximum queue length for tx in packets. 0 is no limit */ 55 int sysctl_dccp_tx_qlen __read_mostly = 5; 56 57 #ifdef CONFIG_IP_DCCP_DEBUG 58 static const char *dccp_state_name(const int state) 59 { 60 static const char *const dccp_state_names[] = { 61 [DCCP_OPEN] = "OPEN", 62 [DCCP_REQUESTING] = "REQUESTING", 63 [DCCP_PARTOPEN] = "PARTOPEN", 64 [DCCP_LISTEN] = "LISTEN", 65 [DCCP_RESPOND] = "RESPOND", 66 [DCCP_CLOSING] = "CLOSING", 67 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ", 68 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE", 69 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ", 70 [DCCP_TIME_WAIT] = "TIME_WAIT", 71 [DCCP_CLOSED] = "CLOSED", 72 }; 73 74 if (state >= DCCP_MAX_STATES) 75 return "INVALID STATE!"; 76 else 77 return dccp_state_names[state]; 78 } 79 #endif 80 81 void dccp_set_state(struct sock *sk, const int state) 82 { 83 const int oldstate = sk->sk_state; 84 85 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk, 86 dccp_state_name(oldstate), dccp_state_name(state)); 87 WARN_ON(state == oldstate); 88 89 switch (state) { 90 case DCCP_OPEN: 91 if (oldstate != DCCP_OPEN) 92 DCCP_INC_STATS(DCCP_MIB_CURRESTAB); 93 /* Client retransmits all Confirm options until entering OPEN */ 94 if (oldstate == DCCP_PARTOPEN) 95 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); 96 break; 97 98 case DCCP_CLOSED: 99 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ || 100 oldstate == DCCP_CLOSING) 101 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); 102 103 sk->sk_prot->unhash(sk); 104 if (inet_csk(sk)->icsk_bind_hash != NULL && 105 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 106 inet_put_port(sk); 107 /* fall through */ 108 default: 109 if (oldstate == DCCP_OPEN) 110 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); 111 } 112 113 /* Change state AFTER socket is unhashed to avoid closed 114 * socket sitting in hash tables. 115 */ 116 inet_sk_set_state(sk, state); 117 } 118 119 EXPORT_SYMBOL_GPL(dccp_set_state); 120 121 static void dccp_finish_passive_close(struct sock *sk) 122 { 123 switch (sk->sk_state) { 124 case DCCP_PASSIVE_CLOSE: 125 /* Node (client or server) has received Close packet. */ 126 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); 127 dccp_set_state(sk, DCCP_CLOSED); 128 break; 129 case DCCP_PASSIVE_CLOSEREQ: 130 /* 131 * Client received CloseReq. We set the `active' flag so that 132 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3. 133 */ 134 dccp_send_close(sk, 1); 135 dccp_set_state(sk, DCCP_CLOSING); 136 } 137 } 138 139 void dccp_done(struct sock *sk) 140 { 141 dccp_set_state(sk, DCCP_CLOSED); 142 dccp_clear_xmit_timers(sk); 143 144 sk->sk_shutdown = SHUTDOWN_MASK; 145 146 if (!sock_flag(sk, SOCK_DEAD)) 147 sk->sk_state_change(sk); 148 else 149 inet_csk_destroy_sock(sk); 150 } 151 152 EXPORT_SYMBOL_GPL(dccp_done); 153 154 const char *dccp_packet_name(const int type) 155 { 156 static const char *const dccp_packet_names[] = { 157 [DCCP_PKT_REQUEST] = "REQUEST", 158 [DCCP_PKT_RESPONSE] = "RESPONSE", 159 [DCCP_PKT_DATA] = "DATA", 160 [DCCP_PKT_ACK] = "ACK", 161 [DCCP_PKT_DATAACK] = "DATAACK", 162 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", 163 [DCCP_PKT_CLOSE] = "CLOSE", 164 [DCCP_PKT_RESET] = "RESET", 165 [DCCP_PKT_SYNC] = "SYNC", 166 [DCCP_PKT_SYNCACK] = "SYNCACK", 167 }; 168 169 if (type >= DCCP_NR_PKT_TYPES) 170 return "INVALID"; 171 else 172 return dccp_packet_names[type]; 173 } 174 175 EXPORT_SYMBOL_GPL(dccp_packet_name); 176 177 static void dccp_sk_destruct(struct sock *sk) 178 { 179 struct dccp_sock *dp = dccp_sk(sk); 180 181 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); 182 dp->dccps_hc_tx_ccid = NULL; 183 inet_sock_destruct(sk); 184 } 185 186 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) 187 { 188 struct dccp_sock *dp = dccp_sk(sk); 189 struct inet_connection_sock *icsk = inet_csk(sk); 190 191 icsk->icsk_rto = DCCP_TIMEOUT_INIT; 192 icsk->icsk_syn_retries = sysctl_dccp_request_retries; 193 sk->sk_state = DCCP_CLOSED; 194 sk->sk_write_space = dccp_write_space; 195 sk->sk_destruct = dccp_sk_destruct; 196 icsk->icsk_sync_mss = dccp_sync_mss; 197 dp->dccps_mss_cache = 536; 198 dp->dccps_rate_last = jiffies; 199 dp->dccps_role = DCCP_ROLE_UNDEFINED; 200 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; 201 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen; 202 203 dccp_init_xmit_timers(sk); 204 205 INIT_LIST_HEAD(&dp->dccps_featneg); 206 /* control socket doesn't need feat nego */ 207 if (likely(ctl_sock_initialized)) 208 return dccp_feat_init(sk); 209 return 0; 210 } 211 212 EXPORT_SYMBOL_GPL(dccp_init_sock); 213 214 void dccp_destroy_sock(struct sock *sk) 215 { 216 struct dccp_sock *dp = dccp_sk(sk); 217 218 __skb_queue_purge(&sk->sk_write_queue); 219 if (sk->sk_send_head != NULL) { 220 kfree_skb(sk->sk_send_head); 221 sk->sk_send_head = NULL; 222 } 223 224 /* Clean up a referenced DCCP bind bucket. */ 225 if (inet_csk(sk)->icsk_bind_hash != NULL) 226 inet_put_port(sk); 227 228 kfree(dp->dccps_service_list); 229 dp->dccps_service_list = NULL; 230 231 if (dp->dccps_hc_rx_ackvec != NULL) { 232 dccp_ackvec_free(dp->dccps_hc_rx_ackvec); 233 dp->dccps_hc_rx_ackvec = NULL; 234 } 235 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 236 dp->dccps_hc_rx_ccid = NULL; 237 238 /* clean up feature negotiation state */ 239 dccp_feat_list_purge(&dp->dccps_featneg); 240 } 241 242 EXPORT_SYMBOL_GPL(dccp_destroy_sock); 243 244 static inline int dccp_listen_start(struct sock *sk, int backlog) 245 { 246 struct dccp_sock *dp = dccp_sk(sk); 247 248 dp->dccps_role = DCCP_ROLE_LISTEN; 249 /* do not start to listen if feature negotiation setup fails */ 250 if (dccp_feat_finalise_settings(dp)) 251 return -EPROTO; 252 return inet_csk_listen_start(sk, backlog); 253 } 254 255 static inline int dccp_need_reset(int state) 256 { 257 return state != DCCP_CLOSED && state != DCCP_LISTEN && 258 state != DCCP_REQUESTING; 259 } 260 261 int dccp_disconnect(struct sock *sk, int flags) 262 { 263 struct inet_connection_sock *icsk = inet_csk(sk); 264 struct inet_sock *inet = inet_sk(sk); 265 struct dccp_sock *dp = dccp_sk(sk); 266 int err = 0; 267 const int old_state = sk->sk_state; 268 269 if (old_state != DCCP_CLOSED) 270 dccp_set_state(sk, DCCP_CLOSED); 271 272 /* 273 * This corresponds to the ABORT function of RFC793, sec. 3.8 274 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted". 275 */ 276 if (old_state == DCCP_LISTEN) { 277 inet_csk_listen_stop(sk); 278 } else if (dccp_need_reset(old_state)) { 279 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 280 sk->sk_err = ECONNRESET; 281 } else if (old_state == DCCP_REQUESTING) 282 sk->sk_err = ECONNRESET; 283 284 dccp_clear_xmit_timers(sk); 285 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 286 dp->dccps_hc_rx_ccid = NULL; 287 288 __skb_queue_purge(&sk->sk_receive_queue); 289 __skb_queue_purge(&sk->sk_write_queue); 290 if (sk->sk_send_head != NULL) { 291 __kfree_skb(sk->sk_send_head); 292 sk->sk_send_head = NULL; 293 } 294 295 inet->inet_dport = 0; 296 297 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 298 inet_reset_saddr(sk); 299 300 sk->sk_shutdown = 0; 301 sock_reset_flag(sk, SOCK_DONE); 302 303 icsk->icsk_backoff = 0; 304 inet_csk_delack_init(sk); 305 __sk_dst_reset(sk); 306 307 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 308 309 sk->sk_error_report(sk); 310 return err; 311 } 312 313 EXPORT_SYMBOL_GPL(dccp_disconnect); 314 315 /* 316 * Wait for a DCCP event. 317 * 318 * Note that we don't need to lock the socket, as the upper poll layers 319 * take care of normal races (between the test and the event) and we don't 320 * go look at any of the socket buffers directly. 321 */ 322 __poll_t dccp_poll(struct file *file, struct socket *sock, 323 poll_table *wait) 324 { 325 __poll_t mask; 326 struct sock *sk = sock->sk; 327 328 sock_poll_wait(file, sock, wait); 329 if (sk->sk_state == DCCP_LISTEN) 330 return inet_csk_listen_poll(sk); 331 332 /* Socket is not locked. We are protected from async events 333 by poll logic and correct handling of state changes 334 made by another threads is impossible in any case. 335 */ 336 337 mask = 0; 338 if (sk->sk_err) 339 mask = EPOLLERR; 340 341 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED) 342 mask |= EPOLLHUP; 343 if (sk->sk_shutdown & RCV_SHUTDOWN) 344 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; 345 346 /* Connected? */ 347 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { 348 if (atomic_read(&sk->sk_rmem_alloc) > 0) 349 mask |= EPOLLIN | EPOLLRDNORM; 350 351 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 352 if (sk_stream_is_writeable(sk)) { 353 mask |= EPOLLOUT | EPOLLWRNORM; 354 } else { /* send SIGIO later */ 355 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 356 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 357 358 /* Race breaker. If space is freed after 359 * wspace test but before the flags are set, 360 * IO signal will be lost. 361 */ 362 if (sk_stream_is_writeable(sk)) 363 mask |= EPOLLOUT | EPOLLWRNORM; 364 } 365 } 366 } 367 return mask; 368 } 369 370 EXPORT_SYMBOL_GPL(dccp_poll); 371 372 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) 373 { 374 int rc = -ENOTCONN; 375 376 lock_sock(sk); 377 378 if (sk->sk_state == DCCP_LISTEN) 379 goto out; 380 381 switch (cmd) { 382 case SIOCINQ: { 383 struct sk_buff *skb; 384 unsigned long amount = 0; 385 386 skb = skb_peek(&sk->sk_receive_queue); 387 if (skb != NULL) { 388 /* 389 * We will only return the amount of this packet since 390 * that is all that will be read. 391 */ 392 amount = skb->len; 393 } 394 rc = put_user(amount, (int __user *)arg); 395 } 396 break; 397 default: 398 rc = -ENOIOCTLCMD; 399 break; 400 } 401 out: 402 release_sock(sk); 403 return rc; 404 } 405 406 EXPORT_SYMBOL_GPL(dccp_ioctl); 407 408 static int dccp_setsockopt_service(struct sock *sk, const __be32 service, 409 char __user *optval, unsigned int optlen) 410 { 411 struct dccp_sock *dp = dccp_sk(sk); 412 struct dccp_service_list *sl = NULL; 413 414 if (service == DCCP_SERVICE_INVALID_VALUE || 415 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) 416 return -EINVAL; 417 418 if (optlen > sizeof(service)) { 419 sl = kmalloc(optlen, GFP_KERNEL); 420 if (sl == NULL) 421 return -ENOMEM; 422 423 sl->dccpsl_nr = optlen / sizeof(u32) - 1; 424 if (copy_from_user(sl->dccpsl_list, 425 optval + sizeof(service), 426 optlen - sizeof(service)) || 427 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { 428 kfree(sl); 429 return -EFAULT; 430 } 431 } 432 433 lock_sock(sk); 434 dp->dccps_service = service; 435 436 kfree(dp->dccps_service_list); 437 438 dp->dccps_service_list = sl; 439 release_sock(sk); 440 return 0; 441 } 442 443 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) 444 { 445 u8 *list, len; 446 int i, rc; 447 448 if (cscov < 0 || cscov > 15) 449 return -EINVAL; 450 /* 451 * Populate a list of permissible values, in the range cscov...15. This 452 * is necessary since feature negotiation of single values only works if 453 * both sides incidentally choose the same value. Since the list starts 454 * lowest-value first, negotiation will pick the smallest shared value. 455 */ 456 if (cscov == 0) 457 return 0; 458 len = 16 - cscov; 459 460 list = kmalloc(len, GFP_KERNEL); 461 if (list == NULL) 462 return -ENOBUFS; 463 464 for (i = 0; i < len; i++) 465 list[i] = cscov++; 466 467 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); 468 469 if (rc == 0) { 470 if (rx) 471 dccp_sk(sk)->dccps_pcrlen = cscov; 472 else 473 dccp_sk(sk)->dccps_pcslen = cscov; 474 } 475 kfree(list); 476 return rc; 477 } 478 479 static int dccp_setsockopt_ccid(struct sock *sk, int type, 480 char __user *optval, unsigned int optlen) 481 { 482 u8 *val; 483 int rc = 0; 484 485 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) 486 return -EINVAL; 487 488 val = memdup_user(optval, optlen); 489 if (IS_ERR(val)) 490 return PTR_ERR(val); 491 492 lock_sock(sk); 493 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) 494 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); 495 496 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) 497 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); 498 release_sock(sk); 499 500 kfree(val); 501 return rc; 502 } 503 504 static int do_dccp_setsockopt(struct sock *sk, int level, int optname, 505 char __user *optval, unsigned int optlen) 506 { 507 struct dccp_sock *dp = dccp_sk(sk); 508 int val, err = 0; 509 510 switch (optname) { 511 case DCCP_SOCKOPT_PACKET_SIZE: 512 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 513 return 0; 514 case DCCP_SOCKOPT_CHANGE_L: 515 case DCCP_SOCKOPT_CHANGE_R: 516 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); 517 return 0; 518 case DCCP_SOCKOPT_CCID: 519 case DCCP_SOCKOPT_RX_CCID: 520 case DCCP_SOCKOPT_TX_CCID: 521 return dccp_setsockopt_ccid(sk, optname, optval, optlen); 522 } 523 524 if (optlen < (int)sizeof(int)) 525 return -EINVAL; 526 527 if (get_user(val, (int __user *)optval)) 528 return -EFAULT; 529 530 if (optname == DCCP_SOCKOPT_SERVICE) 531 return dccp_setsockopt_service(sk, val, optval, optlen); 532 533 lock_sock(sk); 534 switch (optname) { 535 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 536 if (dp->dccps_role != DCCP_ROLE_SERVER) 537 err = -EOPNOTSUPP; 538 else 539 dp->dccps_server_timewait = (val != 0); 540 break; 541 case DCCP_SOCKOPT_SEND_CSCOV: 542 err = dccp_setsockopt_cscov(sk, val, false); 543 break; 544 case DCCP_SOCKOPT_RECV_CSCOV: 545 err = dccp_setsockopt_cscov(sk, val, true); 546 break; 547 case DCCP_SOCKOPT_QPOLICY_ID: 548 if (sk->sk_state != DCCP_CLOSED) 549 err = -EISCONN; 550 else if (val < 0 || val >= DCCPQ_POLICY_MAX) 551 err = -EINVAL; 552 else 553 dp->dccps_qpolicy = val; 554 break; 555 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 556 if (val < 0) 557 err = -EINVAL; 558 else 559 dp->dccps_tx_qlen = val; 560 break; 561 default: 562 err = -ENOPROTOOPT; 563 break; 564 } 565 release_sock(sk); 566 567 return err; 568 } 569 570 int 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(sk)->icsk_af_ops->setsockopt(sk, level, 575 optname, optval, 576 optlen); 577 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 578 } 579 580 EXPORT_SYMBOL_GPL(dccp_setsockopt); 581 582 #ifdef CONFIG_COMPAT 583 int compat_dccp_setsockopt(struct sock *sk, int level, int optname, 584 char __user *optval, unsigned int optlen) 585 { 586 if (level != SOL_DCCP) 587 return inet_csk_compat_setsockopt(sk, level, optname, 588 optval, optlen); 589 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 590 } 591 592 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt); 593 #endif 594 595 static int dccp_getsockopt_service(struct sock *sk, int len, 596 __be32 __user *optval, 597 int __user *optlen) 598 { 599 const struct dccp_sock *dp = dccp_sk(sk); 600 const struct dccp_service_list *sl; 601 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 602 603 lock_sock(sk); 604 if ((sl = dp->dccps_service_list) != NULL) { 605 slen = sl->dccpsl_nr * sizeof(u32); 606 total_len += slen; 607 } 608 609 err = -EINVAL; 610 if (total_len > len) 611 goto out; 612 613 err = 0; 614 if (put_user(total_len, optlen) || 615 put_user(dp->dccps_service, optval) || 616 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 617 err = -EFAULT; 618 out: 619 release_sock(sk); 620 return err; 621 } 622 623 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 624 char __user *optval, int __user *optlen) 625 { 626 struct dccp_sock *dp; 627 int val, len; 628 629 if (get_user(len, optlen)) 630 return -EFAULT; 631 632 if (len < (int)sizeof(int)) 633 return -EINVAL; 634 635 dp = dccp_sk(sk); 636 637 switch (optname) { 638 case DCCP_SOCKOPT_PACKET_SIZE: 639 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 640 return 0; 641 case DCCP_SOCKOPT_SERVICE: 642 return dccp_getsockopt_service(sk, len, 643 (__be32 __user *)optval, optlen); 644 case DCCP_SOCKOPT_GET_CUR_MPS: 645 val = dp->dccps_mss_cache; 646 break; 647 case DCCP_SOCKOPT_AVAILABLE_CCIDS: 648 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); 649 case DCCP_SOCKOPT_TX_CCID: 650 val = ccid_get_current_tx_ccid(dp); 651 if (val < 0) 652 return -ENOPROTOOPT; 653 break; 654 case DCCP_SOCKOPT_RX_CCID: 655 val = ccid_get_current_rx_ccid(dp); 656 if (val < 0) 657 return -ENOPROTOOPT; 658 break; 659 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 660 val = dp->dccps_server_timewait; 661 break; 662 case DCCP_SOCKOPT_SEND_CSCOV: 663 val = dp->dccps_pcslen; 664 break; 665 case DCCP_SOCKOPT_RECV_CSCOV: 666 val = dp->dccps_pcrlen; 667 break; 668 case DCCP_SOCKOPT_QPOLICY_ID: 669 val = dp->dccps_qpolicy; 670 break; 671 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 672 val = dp->dccps_tx_qlen; 673 break; 674 case 128 ... 191: 675 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 676 len, (u32 __user *)optval, optlen); 677 case 192 ... 255: 678 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 679 len, (u32 __user *)optval, optlen); 680 default: 681 return -ENOPROTOOPT; 682 } 683 684 len = sizeof(val); 685 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 686 return -EFAULT; 687 688 return 0; 689 } 690 691 int 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(sk)->icsk_af_ops->getsockopt(sk, level, 696 optname, optval, 697 optlen); 698 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 699 } 700 701 EXPORT_SYMBOL_GPL(dccp_getsockopt); 702 703 #ifdef CONFIG_COMPAT 704 int compat_dccp_getsockopt(struct sock *sk, int level, int optname, 705 char __user *optval, int __user *optlen) 706 { 707 if (level != SOL_DCCP) 708 return inet_csk_compat_getsockopt(sk, level, optname, 709 optval, optlen); 710 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 711 } 712 713 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); 714 #endif 715 716 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) 717 { 718 struct cmsghdr *cmsg; 719 720 /* 721 * Assign an (opaque) qpolicy priority value to skb->priority. 722 * 723 * We are overloading this skb field for use with the qpolicy subystem. 724 * The skb->priority is normally used for the SO_PRIORITY option, which 725 * is initialised from sk_priority. Since the assignment of sk_priority 726 * to skb->priority happens later (on layer 3), we overload this field 727 * for use with queueing priorities as long as the skb is on layer 4. 728 * The default priority value (if nothing is set) is 0. 729 */ 730 skb->priority = 0; 731 732 for_each_cmsghdr(cmsg, msg) { 733 if (!CMSG_OK(msg, cmsg)) 734 return -EINVAL; 735 736 if (cmsg->cmsg_level != SOL_DCCP) 737 continue; 738 739 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && 740 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) 741 return -EINVAL; 742 743 switch (cmsg->cmsg_type) { 744 case DCCP_SCM_PRIORITY: 745 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) 746 return -EINVAL; 747 skb->priority = *(__u32 *)CMSG_DATA(cmsg); 748 break; 749 default: 750 return -EINVAL; 751 } 752 } 753 return 0; 754 } 755 756 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 757 { 758 const struct dccp_sock *dp = dccp_sk(sk); 759 const int flags = msg->msg_flags; 760 const int noblock = flags & MSG_DONTWAIT; 761 struct sk_buff *skb; 762 int rc, size; 763 long timeo; 764 765 trace_dccp_probe(sk, len); 766 767 if (len > dp->dccps_mss_cache) 768 return -EMSGSIZE; 769 770 lock_sock(sk); 771 772 if (dccp_qpolicy_full(sk)) { 773 rc = -EAGAIN; 774 goto out_release; 775 } 776 777 timeo = sock_sndtimeo(sk, noblock); 778 779 /* 780 * We have to use sk_stream_wait_connect here to set sk_write_pending, 781 * so that the trick in dccp_rcv_request_sent_state_process. 782 */ 783 /* Wait for a connection to finish. */ 784 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) 785 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 786 goto out_release; 787 788 size = sk->sk_prot->max_header + len; 789 release_sock(sk); 790 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 791 lock_sock(sk); 792 if (skb == NULL) 793 goto out_release; 794 795 if (sk->sk_state == DCCP_CLOSED) { 796 rc = -ENOTCONN; 797 goto out_discard; 798 } 799 800 skb_reserve(skb, sk->sk_prot->max_header); 801 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 802 if (rc != 0) 803 goto out_discard; 804 805 rc = dccp_msghdr_parse(msg, skb); 806 if (rc != 0) 807 goto out_discard; 808 809 dccp_qpolicy_push(sk, skb); 810 /* 811 * The xmit_timer is set if the TX CCID is rate-based and will expire 812 * when congestion control permits to release further packets into the 813 * network. Window-based CCIDs do not use this timer. 814 */ 815 if (!timer_pending(&dp->dccps_xmit_timer)) 816 dccp_write_xmit(sk); 817 out_release: 818 release_sock(sk); 819 return rc ? : len; 820 out_discard: 821 kfree_skb(skb); 822 goto out_release; 823 } 824 825 EXPORT_SYMBOL_GPL(dccp_sendmsg); 826 827 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 828 int flags, int *addr_len) 829 { 830 const struct dccp_hdr *dh; 831 long timeo; 832 833 lock_sock(sk); 834 835 if (sk->sk_state == DCCP_LISTEN) { 836 len = -ENOTCONN; 837 goto out; 838 } 839 840 timeo = sock_rcvtimeo(sk, nonblock); 841 842 do { 843 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 844 845 if (skb == NULL) 846 goto verify_sock_status; 847 848 dh = dccp_hdr(skb); 849 850 switch (dh->dccph_type) { 851 case DCCP_PKT_DATA: 852 case DCCP_PKT_DATAACK: 853 goto found_ok_skb; 854 855 case DCCP_PKT_CLOSE: 856 case DCCP_PKT_CLOSEREQ: 857 if (!(flags & MSG_PEEK)) 858 dccp_finish_passive_close(sk); 859 /* fall through */ 860 case DCCP_PKT_RESET: 861 dccp_pr_debug("found fin (%s) ok!\n", 862 dccp_packet_name(dh->dccph_type)); 863 len = 0; 864 goto found_fin_ok; 865 default: 866 dccp_pr_debug("packet_type=%s\n", 867 dccp_packet_name(dh->dccph_type)); 868 sk_eat_skb(sk, skb); 869 } 870 verify_sock_status: 871 if (sock_flag(sk, SOCK_DONE)) { 872 len = 0; 873 break; 874 } 875 876 if (sk->sk_err) { 877 len = sock_error(sk); 878 break; 879 } 880 881 if (sk->sk_shutdown & RCV_SHUTDOWN) { 882 len = 0; 883 break; 884 } 885 886 if (sk->sk_state == DCCP_CLOSED) { 887 if (!sock_flag(sk, SOCK_DONE)) { 888 /* This occurs when user tries to read 889 * from never connected socket. 890 */ 891 len = -ENOTCONN; 892 break; 893 } 894 len = 0; 895 break; 896 } 897 898 if (!timeo) { 899 len = -EAGAIN; 900 break; 901 } 902 903 if (signal_pending(current)) { 904 len = sock_intr_errno(timeo); 905 break; 906 } 907 908 sk_wait_data(sk, &timeo, NULL); 909 continue; 910 found_ok_skb: 911 if (len > skb->len) 912 len = skb->len; 913 else if (len < skb->len) 914 msg->msg_flags |= MSG_TRUNC; 915 916 if (skb_copy_datagram_msg(skb, 0, msg, len)) { 917 /* Exception. Bailout! */ 918 len = -EFAULT; 919 break; 920 } 921 if (flags & MSG_TRUNC) 922 len = skb->len; 923 found_fin_ok: 924 if (!(flags & MSG_PEEK)) 925 sk_eat_skb(sk, skb); 926 break; 927 } while (1); 928 out: 929 release_sock(sk); 930 return len; 931 } 932 933 EXPORT_SYMBOL_GPL(dccp_recvmsg); 934 935 int inet_dccp_listen(struct socket *sock, int backlog) 936 { 937 struct sock *sk = sock->sk; 938 unsigned char old_state; 939 int err; 940 941 lock_sock(sk); 942 943 err = -EINVAL; 944 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 945 goto out; 946 947 old_state = sk->sk_state; 948 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 949 goto out; 950 951 sk->sk_max_ack_backlog = backlog; 952 /* Really, if the socket is already in listen state 953 * we can only allow the backlog to be adjusted. 954 */ 955 if (old_state != DCCP_LISTEN) { 956 /* 957 * FIXME: here it probably should be sk->sk_prot->listen_start 958 * see tcp_listen_start 959 */ 960 err = dccp_listen_start(sk, backlog); 961 if (err) 962 goto out; 963 } 964 err = 0; 965 966 out: 967 release_sock(sk); 968 return err; 969 } 970 971 EXPORT_SYMBOL_GPL(inet_dccp_listen); 972 973 static void dccp_terminate_connection(struct sock *sk) 974 { 975 u8 next_state = DCCP_CLOSED; 976 977 switch (sk->sk_state) { 978 case DCCP_PASSIVE_CLOSE: 979 case DCCP_PASSIVE_CLOSEREQ: 980 dccp_finish_passive_close(sk); 981 break; 982 case DCCP_PARTOPEN: 983 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); 984 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); 985 /* fall through */ 986 case DCCP_OPEN: 987 dccp_send_close(sk, 1); 988 989 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && 990 !dccp_sk(sk)->dccps_server_timewait) 991 next_state = DCCP_ACTIVE_CLOSEREQ; 992 else 993 next_state = DCCP_CLOSING; 994 /* fall through */ 995 default: 996 dccp_set_state(sk, next_state); 997 } 998 } 999 1000 void dccp_close(struct sock *sk, long timeout) 1001 { 1002 struct dccp_sock *dp = dccp_sk(sk); 1003 struct sk_buff *skb; 1004 u32 data_was_unread = 0; 1005 int state; 1006 1007 lock_sock(sk); 1008 1009 sk->sk_shutdown = SHUTDOWN_MASK; 1010 1011 if (sk->sk_state == DCCP_LISTEN) { 1012 dccp_set_state(sk, DCCP_CLOSED); 1013 1014 /* Special case. */ 1015 inet_csk_listen_stop(sk); 1016 1017 goto adjudge_to_death; 1018 } 1019 1020 sk_stop_timer(sk, &dp->dccps_xmit_timer); 1021 1022 /* 1023 * We need to flush the recv. buffs. We do this only on the 1024 * descriptor close, not protocol-sourced closes, because the 1025 *reader process may not have drained the data yet! 1026 */ 1027 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1028 data_was_unread += skb->len; 1029 __kfree_skb(skb); 1030 } 1031 1032 /* If socket has been already reset kill it. */ 1033 if (sk->sk_state == DCCP_CLOSED) 1034 goto adjudge_to_death; 1035 1036 if (data_was_unread) { 1037 /* Unread data was tossed, send an appropriate Reset Code */ 1038 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); 1039 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 1040 dccp_set_state(sk, DCCP_CLOSED); 1041 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1042 /* Check zero linger _after_ checking for unread data. */ 1043 sk->sk_prot->disconnect(sk, 0); 1044 } else if (sk->sk_state != DCCP_CLOSED) { 1045 /* 1046 * Normal connection termination. May need to wait if there are 1047 * still packets in the TX queue that are delayed by the CCID. 1048 */ 1049 dccp_flush_write_queue(sk, &timeout); 1050 dccp_terminate_connection(sk); 1051 } 1052 1053 /* 1054 * Flush write queue. This may be necessary in several cases: 1055 * - we have been closed by the peer but still have application data; 1056 * - abortive termination (unread data or zero linger time), 1057 * - normal termination but queue could not be flushed within time limit 1058 */ 1059 __skb_queue_purge(&sk->sk_write_queue); 1060 1061 sk_stream_wait_close(sk, timeout); 1062 1063 adjudge_to_death: 1064 state = sk->sk_state; 1065 sock_hold(sk); 1066 sock_orphan(sk); 1067 1068 /* 1069 * It is the last release_sock in its life. It will remove backlog. 1070 */ 1071 release_sock(sk); 1072 /* 1073 * Now socket is owned by kernel and we acquire BH lock 1074 * to finish close. No need to check for user refs. 1075 */ 1076 local_bh_disable(); 1077 bh_lock_sock(sk); 1078 WARN_ON(sock_owned_by_user(sk)); 1079 1080 percpu_counter_inc(sk->sk_prot->orphan_count); 1081 1082 /* Have we already been destroyed by a softirq or backlog? */ 1083 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 1084 goto out; 1085 1086 if (sk->sk_state == DCCP_CLOSED) 1087 inet_csk_destroy_sock(sk); 1088 1089 /* Otherwise, socket is reprieved until protocol close. */ 1090 1091 out: 1092 bh_unlock_sock(sk); 1093 local_bh_enable(); 1094 sock_put(sk); 1095 } 1096 1097 EXPORT_SYMBOL_GPL(dccp_close); 1098 1099 void dccp_shutdown(struct sock *sk, int how) 1100 { 1101 dccp_pr_debug("called shutdown(%x)\n", how); 1102 } 1103 1104 EXPORT_SYMBOL_GPL(dccp_shutdown); 1105 1106 static inline int __init dccp_mib_init(void) 1107 { 1108 dccp_statistics = alloc_percpu(struct dccp_mib); 1109 if (!dccp_statistics) 1110 return -ENOMEM; 1111 return 0; 1112 } 1113 1114 static inline void dccp_mib_exit(void) 1115 { 1116 free_percpu(dccp_statistics); 1117 } 1118 1119 static int thash_entries; 1120 module_param(thash_entries, int, 0444); 1121 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 1122 1123 #ifdef CONFIG_IP_DCCP_DEBUG 1124 bool dccp_debug; 1125 module_param(dccp_debug, bool, 0644); 1126 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 1127 1128 EXPORT_SYMBOL_GPL(dccp_debug); 1129 #endif 1130 1131 static int __init dccp_init(void) 1132 { 1133 unsigned long goal; 1134 unsigned long nr_pages = totalram_pages(); 1135 int ehash_order, bhash_order, i; 1136 int rc; 1137 1138 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > 1139 FIELD_SIZEOF(struct sk_buff, cb)); 1140 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL); 1141 if (rc) 1142 goto out_fail; 1143 inet_hashinfo_init(&dccp_hashinfo); 1144 rc = inet_hashinfo2_init_mod(&dccp_hashinfo); 1145 if (rc) 1146 goto out_fail; 1147 rc = -ENOBUFS; 1148 dccp_hashinfo.bind_bucket_cachep = 1149 kmem_cache_create("dccp_bind_bucket", 1150 sizeof(struct inet_bind_bucket), 0, 1151 SLAB_HWCACHE_ALIGN, NULL); 1152 if (!dccp_hashinfo.bind_bucket_cachep) 1153 goto out_free_percpu; 1154 1155 /* 1156 * Size and allocate the main established and bind bucket 1157 * hash tables. 1158 * 1159 * The methodology is similar to that of the buffer cache. 1160 */ 1161 if (nr_pages >= (128 * 1024)) 1162 goal = nr_pages >> (21 - PAGE_SHIFT); 1163 else 1164 goal = nr_pages >> (23 - PAGE_SHIFT); 1165 1166 if (thash_entries) 1167 goal = (thash_entries * 1168 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1169 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1170 ; 1171 do { 1172 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / 1173 sizeof(struct inet_ehash_bucket); 1174 1175 while (hash_size & (hash_size - 1)) 1176 hash_size--; 1177 dccp_hashinfo.ehash_mask = hash_size - 1; 1178 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1179 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); 1180 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1181 1182 if (!dccp_hashinfo.ehash) { 1183 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1184 goto out_free_bind_bucket_cachep; 1185 } 1186 1187 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) 1188 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); 1189 1190 if (inet_ehash_locks_alloc(&dccp_hashinfo)) 1191 goto out_free_dccp_ehash; 1192 1193 bhash_order = ehash_order; 1194 1195 do { 1196 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1197 sizeof(struct inet_bind_hashbucket); 1198 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1199 bhash_order > 0) 1200 continue; 1201 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1202 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); 1203 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1204 1205 if (!dccp_hashinfo.bhash) { 1206 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1207 goto out_free_dccp_locks; 1208 } 1209 1210 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1211 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1212 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1213 } 1214 1215 rc = dccp_mib_init(); 1216 if (rc) 1217 goto out_free_dccp_bhash; 1218 1219 rc = dccp_ackvec_init(); 1220 if (rc) 1221 goto out_free_dccp_mib; 1222 1223 rc = dccp_sysctl_init(); 1224 if (rc) 1225 goto out_ackvec_exit; 1226 1227 rc = ccid_initialize_builtins(); 1228 if (rc) 1229 goto out_sysctl_exit; 1230 1231 dccp_timestamping_init(); 1232 1233 return 0; 1234 1235 out_sysctl_exit: 1236 dccp_sysctl_exit(); 1237 out_ackvec_exit: 1238 dccp_ackvec_exit(); 1239 out_free_dccp_mib: 1240 dccp_mib_exit(); 1241 out_free_dccp_bhash: 1242 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1243 out_free_dccp_locks: 1244 inet_ehash_locks_free(&dccp_hashinfo); 1245 out_free_dccp_ehash: 1246 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1247 out_free_bind_bucket_cachep: 1248 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1249 out_free_percpu: 1250 percpu_counter_destroy(&dccp_orphan_count); 1251 out_fail: 1252 dccp_hashinfo.bhash = NULL; 1253 dccp_hashinfo.ehash = NULL; 1254 dccp_hashinfo.bind_bucket_cachep = NULL; 1255 return rc; 1256 } 1257 1258 static void __exit dccp_fini(void) 1259 { 1260 ccid_cleanup_builtins(); 1261 dccp_mib_exit(); 1262 free_pages((unsigned long)dccp_hashinfo.bhash, 1263 get_order(dccp_hashinfo.bhash_size * 1264 sizeof(struct inet_bind_hashbucket))); 1265 free_pages((unsigned long)dccp_hashinfo.ehash, 1266 get_order((dccp_hashinfo.ehash_mask + 1) * 1267 sizeof(struct inet_ehash_bucket))); 1268 inet_ehash_locks_free(&dccp_hashinfo); 1269 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1270 dccp_ackvec_exit(); 1271 dccp_sysctl_exit(); 1272 percpu_counter_destroy(&dccp_orphan_count); 1273 } 1274 1275 module_init(dccp_init); 1276 module_exit(dccp_fini); 1277 1278 MODULE_LICENSE("GPL"); 1279 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1280 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1281