1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * net/dccp/proto.c 4 * 5 * An implementation of the DCCP protocol 6 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 7 */ 8 9 #include <linux/dccp.h> 10 #include <linux/module.h> 11 #include <linux/types.h> 12 #include <linux/sched.h> 13 #include <linux/kernel.h> 14 #include <linux/skbuff.h> 15 #include <linux/netdevice.h> 16 #include <linux/in.h> 17 #include <linux/if_arp.h> 18 #include <linux/init.h> 19 #include <linux/random.h> 20 #include <linux/slab.h> 21 #include <net/checksum.h> 22 23 #include <net/inet_sock.h> 24 #include <net/inet_common.h> 25 #include <net/sock.h> 26 #include <net/xfrm.h> 27 28 #include <asm/ioctls.h> 29 #include <linux/spinlock.h> 30 #include <linux/timer.h> 31 #include <linux/delay.h> 32 #include <linux/poll.h> 33 34 #include "ccid.h" 35 #include "dccp.h" 36 #include "feat.h" 37 38 #define CREATE_TRACE_POINTS 39 #include "trace.h" 40 41 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; 42 43 EXPORT_SYMBOL_GPL(dccp_statistics); 44 45 struct percpu_counter dccp_orphan_count; 46 EXPORT_SYMBOL_GPL(dccp_orphan_count); 47 48 struct inet_hashinfo dccp_hashinfo; 49 EXPORT_SYMBOL_GPL(dccp_hashinfo); 50 51 /* the maximum queue length for tx in packets. 0 is no limit */ 52 int sysctl_dccp_tx_qlen __read_mostly = 5; 53 54 #ifdef CONFIG_IP_DCCP_DEBUG 55 static const char *dccp_state_name(const int state) 56 { 57 static const char *const dccp_state_names[] = { 58 [DCCP_OPEN] = "OPEN", 59 [DCCP_REQUESTING] = "REQUESTING", 60 [DCCP_PARTOPEN] = "PARTOPEN", 61 [DCCP_LISTEN] = "LISTEN", 62 [DCCP_RESPOND] = "RESPOND", 63 [DCCP_CLOSING] = "CLOSING", 64 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ", 65 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE", 66 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ", 67 [DCCP_TIME_WAIT] = "TIME_WAIT", 68 [DCCP_CLOSED] = "CLOSED", 69 }; 70 71 if (state >= DCCP_MAX_STATES) 72 return "INVALID STATE!"; 73 else 74 return dccp_state_names[state]; 75 } 76 #endif 77 78 void dccp_set_state(struct sock *sk, const int state) 79 { 80 const int oldstate = sk->sk_state; 81 82 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk, 83 dccp_state_name(oldstate), dccp_state_name(state)); 84 WARN_ON(state == oldstate); 85 86 switch (state) { 87 case DCCP_OPEN: 88 if (oldstate != DCCP_OPEN) 89 DCCP_INC_STATS(DCCP_MIB_CURRESTAB); 90 /* Client retransmits all Confirm options until entering OPEN */ 91 if (oldstate == DCCP_PARTOPEN) 92 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); 93 break; 94 95 case DCCP_CLOSED: 96 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ || 97 oldstate == DCCP_CLOSING) 98 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); 99 100 sk->sk_prot->unhash(sk); 101 if (inet_csk(sk)->icsk_bind_hash != NULL && 102 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 103 inet_put_port(sk); 104 /* fall through */ 105 default: 106 if (oldstate == DCCP_OPEN) 107 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); 108 } 109 110 /* Change state AFTER socket is unhashed to avoid closed 111 * socket sitting in hash tables. 112 */ 113 inet_sk_set_state(sk, state); 114 } 115 116 EXPORT_SYMBOL_GPL(dccp_set_state); 117 118 static void dccp_finish_passive_close(struct sock *sk) 119 { 120 switch (sk->sk_state) { 121 case DCCP_PASSIVE_CLOSE: 122 /* Node (client or server) has received Close packet. */ 123 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); 124 dccp_set_state(sk, DCCP_CLOSED); 125 break; 126 case DCCP_PASSIVE_CLOSEREQ: 127 /* 128 * Client received CloseReq. We set the `active' flag so that 129 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3. 130 */ 131 dccp_send_close(sk, 1); 132 dccp_set_state(sk, DCCP_CLOSING); 133 } 134 } 135 136 void dccp_done(struct sock *sk) 137 { 138 dccp_set_state(sk, DCCP_CLOSED); 139 dccp_clear_xmit_timers(sk); 140 141 sk->sk_shutdown = SHUTDOWN_MASK; 142 143 if (!sock_flag(sk, SOCK_DEAD)) 144 sk->sk_state_change(sk); 145 else 146 inet_csk_destroy_sock(sk); 147 } 148 149 EXPORT_SYMBOL_GPL(dccp_done); 150 151 const char *dccp_packet_name(const int type) 152 { 153 static const char *const dccp_packet_names[] = { 154 [DCCP_PKT_REQUEST] = "REQUEST", 155 [DCCP_PKT_RESPONSE] = "RESPONSE", 156 [DCCP_PKT_DATA] = "DATA", 157 [DCCP_PKT_ACK] = "ACK", 158 [DCCP_PKT_DATAACK] = "DATAACK", 159 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", 160 [DCCP_PKT_CLOSE] = "CLOSE", 161 [DCCP_PKT_RESET] = "RESET", 162 [DCCP_PKT_SYNC] = "SYNC", 163 [DCCP_PKT_SYNCACK] = "SYNCACK", 164 }; 165 166 if (type >= DCCP_NR_PKT_TYPES) 167 return "INVALID"; 168 else 169 return dccp_packet_names[type]; 170 } 171 172 EXPORT_SYMBOL_GPL(dccp_packet_name); 173 174 static void dccp_sk_destruct(struct sock *sk) 175 { 176 struct dccp_sock *dp = dccp_sk(sk); 177 178 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); 179 dp->dccps_hc_tx_ccid = NULL; 180 inet_sock_destruct(sk); 181 } 182 183 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) 184 { 185 struct dccp_sock *dp = dccp_sk(sk); 186 struct inet_connection_sock *icsk = inet_csk(sk); 187 188 icsk->icsk_rto = DCCP_TIMEOUT_INIT; 189 icsk->icsk_syn_retries = sysctl_dccp_request_retries; 190 sk->sk_state = DCCP_CLOSED; 191 sk->sk_write_space = dccp_write_space; 192 sk->sk_destruct = dccp_sk_destruct; 193 icsk->icsk_sync_mss = dccp_sync_mss; 194 dp->dccps_mss_cache = 536; 195 dp->dccps_rate_last = jiffies; 196 dp->dccps_role = DCCP_ROLE_UNDEFINED; 197 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; 198 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen; 199 200 dccp_init_xmit_timers(sk); 201 202 INIT_LIST_HEAD(&dp->dccps_featneg); 203 /* control socket doesn't need feat nego */ 204 if (likely(ctl_sock_initialized)) 205 return dccp_feat_init(sk); 206 return 0; 207 } 208 209 EXPORT_SYMBOL_GPL(dccp_init_sock); 210 211 void dccp_destroy_sock(struct sock *sk) 212 { 213 struct dccp_sock *dp = dccp_sk(sk); 214 215 __skb_queue_purge(&sk->sk_write_queue); 216 if (sk->sk_send_head != NULL) { 217 kfree_skb(sk->sk_send_head); 218 sk->sk_send_head = NULL; 219 } 220 221 /* Clean up a referenced DCCP bind bucket. */ 222 if (inet_csk(sk)->icsk_bind_hash != NULL) 223 inet_put_port(sk); 224 225 kfree(dp->dccps_service_list); 226 dp->dccps_service_list = NULL; 227 228 if (dp->dccps_hc_rx_ackvec != NULL) { 229 dccp_ackvec_free(dp->dccps_hc_rx_ackvec); 230 dp->dccps_hc_rx_ackvec = NULL; 231 } 232 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 233 dp->dccps_hc_rx_ccid = NULL; 234 235 /* clean up feature negotiation state */ 236 dccp_feat_list_purge(&dp->dccps_featneg); 237 } 238 239 EXPORT_SYMBOL_GPL(dccp_destroy_sock); 240 241 static inline int dccp_listen_start(struct sock *sk, int backlog) 242 { 243 struct dccp_sock *dp = dccp_sk(sk); 244 245 dp->dccps_role = DCCP_ROLE_LISTEN; 246 /* do not start to listen if feature negotiation setup fails */ 247 if (dccp_feat_finalise_settings(dp)) 248 return -EPROTO; 249 return inet_csk_listen_start(sk, backlog); 250 } 251 252 static inline int dccp_need_reset(int state) 253 { 254 return state != DCCP_CLOSED && state != DCCP_LISTEN && 255 state != DCCP_REQUESTING; 256 } 257 258 int dccp_disconnect(struct sock *sk, int flags) 259 { 260 struct inet_connection_sock *icsk = inet_csk(sk); 261 struct inet_sock *inet = inet_sk(sk); 262 struct dccp_sock *dp = dccp_sk(sk); 263 const int old_state = sk->sk_state; 264 265 if (old_state != DCCP_CLOSED) 266 dccp_set_state(sk, DCCP_CLOSED); 267 268 /* 269 * This corresponds to the ABORT function of RFC793, sec. 3.8 270 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted". 271 */ 272 if (old_state == DCCP_LISTEN) { 273 inet_csk_listen_stop(sk); 274 } else if (dccp_need_reset(old_state)) { 275 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 276 sk->sk_err = ECONNRESET; 277 } else if (old_state == DCCP_REQUESTING) 278 sk->sk_err = ECONNRESET; 279 280 dccp_clear_xmit_timers(sk); 281 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); 282 dp->dccps_hc_rx_ccid = NULL; 283 284 __skb_queue_purge(&sk->sk_receive_queue); 285 __skb_queue_purge(&sk->sk_write_queue); 286 if (sk->sk_send_head != NULL) { 287 __kfree_skb(sk->sk_send_head); 288 sk->sk_send_head = NULL; 289 } 290 291 inet->inet_dport = 0; 292 293 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 294 inet_reset_saddr(sk); 295 296 sk->sk_shutdown = 0; 297 sock_reset_flag(sk, SOCK_DONE); 298 299 icsk->icsk_backoff = 0; 300 inet_csk_delack_init(sk); 301 __sk_dst_reset(sk); 302 303 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); 304 305 sk->sk_error_report(sk); 306 return 0; 307 } 308 309 EXPORT_SYMBOL_GPL(dccp_disconnect); 310 311 /* 312 * Wait for a DCCP event. 313 * 314 * Note that we don't need to lock the socket, as the upper poll layers 315 * take care of normal races (between the test and the event) and we don't 316 * go look at any of the socket buffers directly. 317 */ 318 __poll_t dccp_poll(struct file *file, struct socket *sock, 319 poll_table *wait) 320 { 321 __poll_t mask; 322 struct sock *sk = sock->sk; 323 324 sock_poll_wait(file, sock, wait); 325 if (sk->sk_state == DCCP_LISTEN) 326 return inet_csk_listen_poll(sk); 327 328 /* Socket is not locked. We are protected from async events 329 by poll logic and correct handling of state changes 330 made by another threads is impossible in any case. 331 */ 332 333 mask = 0; 334 if (sk->sk_err) 335 mask = EPOLLERR; 336 337 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED) 338 mask |= EPOLLHUP; 339 if (sk->sk_shutdown & RCV_SHUTDOWN) 340 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; 341 342 /* Connected? */ 343 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { 344 if (atomic_read(&sk->sk_rmem_alloc) > 0) 345 mask |= EPOLLIN | EPOLLRDNORM; 346 347 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { 348 if (sk_stream_is_writeable(sk)) { 349 mask |= EPOLLOUT | EPOLLWRNORM; 350 } else { /* send SIGIO later */ 351 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 352 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 353 354 /* Race breaker. If space is freed after 355 * wspace test but before the flags are set, 356 * IO signal will be lost. 357 */ 358 if (sk_stream_is_writeable(sk)) 359 mask |= EPOLLOUT | EPOLLWRNORM; 360 } 361 } 362 } 363 return mask; 364 } 365 366 EXPORT_SYMBOL_GPL(dccp_poll); 367 368 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) 369 { 370 int rc = -ENOTCONN; 371 372 lock_sock(sk); 373 374 if (sk->sk_state == DCCP_LISTEN) 375 goto out; 376 377 switch (cmd) { 378 case SIOCOUTQ: { 379 int amount = sk_wmem_alloc_get(sk); 380 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and 381 * always 0, comparably to UDP. 382 */ 383 384 rc = put_user(amount, (int __user *)arg); 385 } 386 break; 387 case SIOCINQ: { 388 struct sk_buff *skb; 389 unsigned long amount = 0; 390 391 skb = skb_peek(&sk->sk_receive_queue); 392 if (skb != NULL) { 393 /* 394 * We will only return the amount of this packet since 395 * that is all that will be read. 396 */ 397 amount = skb->len; 398 } 399 rc = put_user(amount, (int __user *)arg); 400 } 401 break; 402 default: 403 rc = -ENOIOCTLCMD; 404 break; 405 } 406 out: 407 release_sock(sk); 408 return rc; 409 } 410 411 EXPORT_SYMBOL_GPL(dccp_ioctl); 412 413 static int dccp_setsockopt_service(struct sock *sk, const __be32 service, 414 sockptr_t optval, unsigned int optlen) 415 { 416 struct dccp_sock *dp = dccp_sk(sk); 417 struct dccp_service_list *sl = NULL; 418 419 if (service == DCCP_SERVICE_INVALID_VALUE || 420 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) 421 return -EINVAL; 422 423 if (optlen > sizeof(service)) { 424 sl = kmalloc(optlen, GFP_KERNEL); 425 if (sl == NULL) 426 return -ENOMEM; 427 428 sl->dccpsl_nr = optlen / sizeof(u32) - 1; 429 sockptr_advance(optval, sizeof(service)); 430 if (copy_from_sockptr(sl->dccpsl_list, optval, 431 optlen - sizeof(service)) || 432 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { 433 kfree(sl); 434 return -EFAULT; 435 } 436 } 437 438 lock_sock(sk); 439 dp->dccps_service = service; 440 441 kfree(dp->dccps_service_list); 442 443 dp->dccps_service_list = sl; 444 release_sock(sk); 445 return 0; 446 } 447 448 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) 449 { 450 u8 *list, len; 451 int i, rc; 452 453 if (cscov < 0 || cscov > 15) 454 return -EINVAL; 455 /* 456 * Populate a list of permissible values, in the range cscov...15. This 457 * is necessary since feature negotiation of single values only works if 458 * both sides incidentally choose the same value. Since the list starts 459 * lowest-value first, negotiation will pick the smallest shared value. 460 */ 461 if (cscov == 0) 462 return 0; 463 len = 16 - cscov; 464 465 list = kmalloc(len, GFP_KERNEL); 466 if (list == NULL) 467 return -ENOBUFS; 468 469 for (i = 0; i < len; i++) 470 list[i] = cscov++; 471 472 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); 473 474 if (rc == 0) { 475 if (rx) 476 dccp_sk(sk)->dccps_pcrlen = cscov; 477 else 478 dccp_sk(sk)->dccps_pcslen = cscov; 479 } 480 kfree(list); 481 return rc; 482 } 483 484 static int dccp_setsockopt_ccid(struct sock *sk, int type, 485 sockptr_t optval, unsigned int optlen) 486 { 487 u8 *val; 488 int rc = 0; 489 490 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) 491 return -EINVAL; 492 493 val = memdup_sockptr(optval, optlen); 494 if (IS_ERR(val)) 495 return PTR_ERR(val); 496 497 lock_sock(sk); 498 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) 499 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); 500 501 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) 502 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); 503 release_sock(sk); 504 505 kfree(val); 506 return rc; 507 } 508 509 static int do_dccp_setsockopt(struct sock *sk, int level, int optname, 510 sockptr_t optval, unsigned int optlen) 511 { 512 struct dccp_sock *dp = dccp_sk(sk); 513 int val, err = 0; 514 515 switch (optname) { 516 case DCCP_SOCKOPT_PACKET_SIZE: 517 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 518 return 0; 519 case DCCP_SOCKOPT_CHANGE_L: 520 case DCCP_SOCKOPT_CHANGE_R: 521 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); 522 return 0; 523 case DCCP_SOCKOPT_CCID: 524 case DCCP_SOCKOPT_RX_CCID: 525 case DCCP_SOCKOPT_TX_CCID: 526 return dccp_setsockopt_ccid(sk, optname, optval, optlen); 527 } 528 529 if (optlen < (int)sizeof(int)) 530 return -EINVAL; 531 532 if (copy_from_sockptr(&val, optval, sizeof(int))) 533 return -EFAULT; 534 535 if (optname == DCCP_SOCKOPT_SERVICE) 536 return dccp_setsockopt_service(sk, val, optval, optlen); 537 538 lock_sock(sk); 539 switch (optname) { 540 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 541 if (dp->dccps_role != DCCP_ROLE_SERVER) 542 err = -EOPNOTSUPP; 543 else 544 dp->dccps_server_timewait = (val != 0); 545 break; 546 case DCCP_SOCKOPT_SEND_CSCOV: 547 err = dccp_setsockopt_cscov(sk, val, false); 548 break; 549 case DCCP_SOCKOPT_RECV_CSCOV: 550 err = dccp_setsockopt_cscov(sk, val, true); 551 break; 552 case DCCP_SOCKOPT_QPOLICY_ID: 553 if (sk->sk_state != DCCP_CLOSED) 554 err = -EISCONN; 555 else if (val < 0 || val >= DCCPQ_POLICY_MAX) 556 err = -EINVAL; 557 else 558 dp->dccps_qpolicy = val; 559 break; 560 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 561 if (val < 0) 562 err = -EINVAL; 563 else 564 dp->dccps_tx_qlen = val; 565 break; 566 default: 567 err = -ENOPROTOOPT; 568 break; 569 } 570 release_sock(sk); 571 572 return err; 573 } 574 575 int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 576 unsigned int optlen) 577 { 578 if (level != SOL_DCCP) 579 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, 580 optname, optval, 581 optlen); 582 return do_dccp_setsockopt(sk, level, optname, optval, optlen); 583 } 584 585 EXPORT_SYMBOL_GPL(dccp_setsockopt); 586 587 static int dccp_getsockopt_service(struct sock *sk, int len, 588 __be32 __user *optval, 589 int __user *optlen) 590 { 591 const struct dccp_sock *dp = dccp_sk(sk); 592 const struct dccp_service_list *sl; 593 int err = -ENOENT, slen = 0, total_len = sizeof(u32); 594 595 lock_sock(sk); 596 if ((sl = dp->dccps_service_list) != NULL) { 597 slen = sl->dccpsl_nr * sizeof(u32); 598 total_len += slen; 599 } 600 601 err = -EINVAL; 602 if (total_len > len) 603 goto out; 604 605 err = 0; 606 if (put_user(total_len, optlen) || 607 put_user(dp->dccps_service, optval) || 608 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) 609 err = -EFAULT; 610 out: 611 release_sock(sk); 612 return err; 613 } 614 615 static int do_dccp_getsockopt(struct sock *sk, int level, int optname, 616 char __user *optval, int __user *optlen) 617 { 618 struct dccp_sock *dp; 619 int val, len; 620 621 if (get_user(len, optlen)) 622 return -EFAULT; 623 624 if (len < (int)sizeof(int)) 625 return -EINVAL; 626 627 dp = dccp_sk(sk); 628 629 switch (optname) { 630 case DCCP_SOCKOPT_PACKET_SIZE: 631 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); 632 return 0; 633 case DCCP_SOCKOPT_SERVICE: 634 return dccp_getsockopt_service(sk, len, 635 (__be32 __user *)optval, optlen); 636 case DCCP_SOCKOPT_GET_CUR_MPS: 637 val = dp->dccps_mss_cache; 638 break; 639 case DCCP_SOCKOPT_AVAILABLE_CCIDS: 640 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); 641 case DCCP_SOCKOPT_TX_CCID: 642 val = ccid_get_current_tx_ccid(dp); 643 if (val < 0) 644 return -ENOPROTOOPT; 645 break; 646 case DCCP_SOCKOPT_RX_CCID: 647 val = ccid_get_current_rx_ccid(dp); 648 if (val < 0) 649 return -ENOPROTOOPT; 650 break; 651 case DCCP_SOCKOPT_SERVER_TIMEWAIT: 652 val = dp->dccps_server_timewait; 653 break; 654 case DCCP_SOCKOPT_SEND_CSCOV: 655 val = dp->dccps_pcslen; 656 break; 657 case DCCP_SOCKOPT_RECV_CSCOV: 658 val = dp->dccps_pcrlen; 659 break; 660 case DCCP_SOCKOPT_QPOLICY_ID: 661 val = dp->dccps_qpolicy; 662 break; 663 case DCCP_SOCKOPT_QPOLICY_TXQLEN: 664 val = dp->dccps_tx_qlen; 665 break; 666 case 128 ... 191: 667 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, 668 len, (u32 __user *)optval, optlen); 669 case 192 ... 255: 670 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, 671 len, (u32 __user *)optval, optlen); 672 default: 673 return -ENOPROTOOPT; 674 } 675 676 len = sizeof(val); 677 if (put_user(len, optlen) || copy_to_user(optval, &val, len)) 678 return -EFAULT; 679 680 return 0; 681 } 682 683 int dccp_getsockopt(struct sock *sk, int level, int optname, 684 char __user *optval, int __user *optlen) 685 { 686 if (level != SOL_DCCP) 687 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, 688 optname, optval, 689 optlen); 690 return do_dccp_getsockopt(sk, level, optname, optval, optlen); 691 } 692 693 EXPORT_SYMBOL_GPL(dccp_getsockopt); 694 695 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) 696 { 697 struct cmsghdr *cmsg; 698 699 /* 700 * Assign an (opaque) qpolicy priority value to skb->priority. 701 * 702 * We are overloading this skb field for use with the qpolicy subystem. 703 * The skb->priority is normally used for the SO_PRIORITY option, which 704 * is initialised from sk_priority. Since the assignment of sk_priority 705 * to skb->priority happens later (on layer 3), we overload this field 706 * for use with queueing priorities as long as the skb is on layer 4. 707 * The default priority value (if nothing is set) is 0. 708 */ 709 skb->priority = 0; 710 711 for_each_cmsghdr(cmsg, msg) { 712 if (!CMSG_OK(msg, cmsg)) 713 return -EINVAL; 714 715 if (cmsg->cmsg_level != SOL_DCCP) 716 continue; 717 718 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && 719 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) 720 return -EINVAL; 721 722 switch (cmsg->cmsg_type) { 723 case DCCP_SCM_PRIORITY: 724 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) 725 return -EINVAL; 726 skb->priority = *(__u32 *)CMSG_DATA(cmsg); 727 break; 728 default: 729 return -EINVAL; 730 } 731 } 732 return 0; 733 } 734 735 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 736 { 737 const struct dccp_sock *dp = dccp_sk(sk); 738 const int flags = msg->msg_flags; 739 const int noblock = flags & MSG_DONTWAIT; 740 struct sk_buff *skb; 741 int rc, size; 742 long timeo; 743 744 trace_dccp_probe(sk, len); 745 746 if (len > dp->dccps_mss_cache) 747 return -EMSGSIZE; 748 749 lock_sock(sk); 750 751 if (dccp_qpolicy_full(sk)) { 752 rc = -EAGAIN; 753 goto out_release; 754 } 755 756 timeo = sock_sndtimeo(sk, noblock); 757 758 /* 759 * We have to use sk_stream_wait_connect here to set sk_write_pending, 760 * so that the trick in dccp_rcv_request_sent_state_process. 761 */ 762 /* Wait for a connection to finish. */ 763 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) 764 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) 765 goto out_release; 766 767 size = sk->sk_prot->max_header + len; 768 release_sock(sk); 769 skb = sock_alloc_send_skb(sk, size, noblock, &rc); 770 lock_sock(sk); 771 if (skb == NULL) 772 goto out_release; 773 774 if (sk->sk_state == DCCP_CLOSED) { 775 rc = -ENOTCONN; 776 goto out_discard; 777 } 778 779 skb_reserve(skb, sk->sk_prot->max_header); 780 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 781 if (rc != 0) 782 goto out_discard; 783 784 rc = dccp_msghdr_parse(msg, skb); 785 if (rc != 0) 786 goto out_discard; 787 788 dccp_qpolicy_push(sk, skb); 789 /* 790 * The xmit_timer is set if the TX CCID is rate-based and will expire 791 * when congestion control permits to release further packets into the 792 * network. Window-based CCIDs do not use this timer. 793 */ 794 if (!timer_pending(&dp->dccps_xmit_timer)) 795 dccp_write_xmit(sk); 796 out_release: 797 release_sock(sk); 798 return rc ? : len; 799 out_discard: 800 kfree_skb(skb); 801 goto out_release; 802 } 803 804 EXPORT_SYMBOL_GPL(dccp_sendmsg); 805 806 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 807 int flags, int *addr_len) 808 { 809 const struct dccp_hdr *dh; 810 long timeo; 811 812 lock_sock(sk); 813 814 if (sk->sk_state == DCCP_LISTEN) { 815 len = -ENOTCONN; 816 goto out; 817 } 818 819 timeo = sock_rcvtimeo(sk, nonblock); 820 821 do { 822 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); 823 824 if (skb == NULL) 825 goto verify_sock_status; 826 827 dh = dccp_hdr(skb); 828 829 switch (dh->dccph_type) { 830 case DCCP_PKT_DATA: 831 case DCCP_PKT_DATAACK: 832 goto found_ok_skb; 833 834 case DCCP_PKT_CLOSE: 835 case DCCP_PKT_CLOSEREQ: 836 if (!(flags & MSG_PEEK)) 837 dccp_finish_passive_close(sk); 838 /* fall through */ 839 case DCCP_PKT_RESET: 840 dccp_pr_debug("found fin (%s) ok!\n", 841 dccp_packet_name(dh->dccph_type)); 842 len = 0; 843 goto found_fin_ok; 844 default: 845 dccp_pr_debug("packet_type=%s\n", 846 dccp_packet_name(dh->dccph_type)); 847 sk_eat_skb(sk, skb); 848 } 849 verify_sock_status: 850 if (sock_flag(sk, SOCK_DONE)) { 851 len = 0; 852 break; 853 } 854 855 if (sk->sk_err) { 856 len = sock_error(sk); 857 break; 858 } 859 860 if (sk->sk_shutdown & RCV_SHUTDOWN) { 861 len = 0; 862 break; 863 } 864 865 if (sk->sk_state == DCCP_CLOSED) { 866 if (!sock_flag(sk, SOCK_DONE)) { 867 /* This occurs when user tries to read 868 * from never connected socket. 869 */ 870 len = -ENOTCONN; 871 break; 872 } 873 len = 0; 874 break; 875 } 876 877 if (!timeo) { 878 len = -EAGAIN; 879 break; 880 } 881 882 if (signal_pending(current)) { 883 len = sock_intr_errno(timeo); 884 break; 885 } 886 887 sk_wait_data(sk, &timeo, NULL); 888 continue; 889 found_ok_skb: 890 if (len > skb->len) 891 len = skb->len; 892 else if (len < skb->len) 893 msg->msg_flags |= MSG_TRUNC; 894 895 if (skb_copy_datagram_msg(skb, 0, msg, len)) { 896 /* Exception. Bailout! */ 897 len = -EFAULT; 898 break; 899 } 900 if (flags & MSG_TRUNC) 901 len = skb->len; 902 found_fin_ok: 903 if (!(flags & MSG_PEEK)) 904 sk_eat_skb(sk, skb); 905 break; 906 } while (1); 907 out: 908 release_sock(sk); 909 return len; 910 } 911 912 EXPORT_SYMBOL_GPL(dccp_recvmsg); 913 914 int inet_dccp_listen(struct socket *sock, int backlog) 915 { 916 struct sock *sk = sock->sk; 917 unsigned char old_state; 918 int err; 919 920 lock_sock(sk); 921 922 err = -EINVAL; 923 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) 924 goto out; 925 926 old_state = sk->sk_state; 927 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) 928 goto out; 929 930 WRITE_ONCE(sk->sk_max_ack_backlog, backlog); 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 err = 0; 944 945 out: 946 release_sock(sk); 947 return err; 948 } 949 950 EXPORT_SYMBOL_GPL(inet_dccp_listen); 951 952 static void dccp_terminate_connection(struct sock *sk) 953 { 954 u8 next_state = DCCP_CLOSED; 955 956 switch (sk->sk_state) { 957 case DCCP_PASSIVE_CLOSE: 958 case DCCP_PASSIVE_CLOSEREQ: 959 dccp_finish_passive_close(sk); 960 break; 961 case DCCP_PARTOPEN: 962 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); 963 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); 964 /* fall through */ 965 case DCCP_OPEN: 966 dccp_send_close(sk, 1); 967 968 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && 969 !dccp_sk(sk)->dccps_server_timewait) 970 next_state = DCCP_ACTIVE_CLOSEREQ; 971 else 972 next_state = DCCP_CLOSING; 973 /* fall through */ 974 default: 975 dccp_set_state(sk, next_state); 976 } 977 } 978 979 void dccp_close(struct sock *sk, long timeout) 980 { 981 struct dccp_sock *dp = dccp_sk(sk); 982 struct sk_buff *skb; 983 u32 data_was_unread = 0; 984 int state; 985 986 lock_sock(sk); 987 988 sk->sk_shutdown = SHUTDOWN_MASK; 989 990 if (sk->sk_state == DCCP_LISTEN) { 991 dccp_set_state(sk, DCCP_CLOSED); 992 993 /* Special case. */ 994 inet_csk_listen_stop(sk); 995 996 goto adjudge_to_death; 997 } 998 999 sk_stop_timer(sk, &dp->dccps_xmit_timer); 1000 1001 /* 1002 * We need to flush the recv. buffs. We do this only on the 1003 * descriptor close, not protocol-sourced closes, because the 1004 *reader process may not have drained the data yet! 1005 */ 1006 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { 1007 data_was_unread += skb->len; 1008 __kfree_skb(skb); 1009 } 1010 1011 /* If socket has been already reset kill it. */ 1012 if (sk->sk_state == DCCP_CLOSED) 1013 goto adjudge_to_death; 1014 1015 if (data_was_unread) { 1016 /* Unread data was tossed, send an appropriate Reset Code */ 1017 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); 1018 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); 1019 dccp_set_state(sk, DCCP_CLOSED); 1020 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { 1021 /* Check zero linger _after_ checking for unread data. */ 1022 sk->sk_prot->disconnect(sk, 0); 1023 } else if (sk->sk_state != DCCP_CLOSED) { 1024 /* 1025 * Normal connection termination. May need to wait if there are 1026 * still packets in the TX queue that are delayed by the CCID. 1027 */ 1028 dccp_flush_write_queue(sk, &timeout); 1029 dccp_terminate_connection(sk); 1030 } 1031 1032 /* 1033 * Flush write queue. This may be necessary in several cases: 1034 * - we have been closed by the peer but still have application data; 1035 * - abortive termination (unread data or zero linger time), 1036 * - normal termination but queue could not be flushed within time limit 1037 */ 1038 __skb_queue_purge(&sk->sk_write_queue); 1039 1040 sk_stream_wait_close(sk, timeout); 1041 1042 adjudge_to_death: 1043 state = sk->sk_state; 1044 sock_hold(sk); 1045 sock_orphan(sk); 1046 1047 /* 1048 * It is the last release_sock in its life. It will remove backlog. 1049 */ 1050 release_sock(sk); 1051 /* 1052 * Now socket is owned by kernel and we acquire BH lock 1053 * to finish close. No need to check for user refs. 1054 */ 1055 local_bh_disable(); 1056 bh_lock_sock(sk); 1057 WARN_ON(sock_owned_by_user(sk)); 1058 1059 percpu_counter_inc(sk->sk_prot->orphan_count); 1060 1061 /* Have we already been destroyed by a softirq or backlog? */ 1062 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) 1063 goto out; 1064 1065 if (sk->sk_state == DCCP_CLOSED) 1066 inet_csk_destroy_sock(sk); 1067 1068 /* Otherwise, socket is reprieved until protocol close. */ 1069 1070 out: 1071 bh_unlock_sock(sk); 1072 local_bh_enable(); 1073 sock_put(sk); 1074 } 1075 1076 EXPORT_SYMBOL_GPL(dccp_close); 1077 1078 void dccp_shutdown(struct sock *sk, int how) 1079 { 1080 dccp_pr_debug("called shutdown(%x)\n", how); 1081 } 1082 1083 EXPORT_SYMBOL_GPL(dccp_shutdown); 1084 1085 static inline int __init dccp_mib_init(void) 1086 { 1087 dccp_statistics = alloc_percpu(struct dccp_mib); 1088 if (!dccp_statistics) 1089 return -ENOMEM; 1090 return 0; 1091 } 1092 1093 static inline void dccp_mib_exit(void) 1094 { 1095 free_percpu(dccp_statistics); 1096 } 1097 1098 static int thash_entries; 1099 module_param(thash_entries, int, 0444); 1100 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); 1101 1102 #ifdef CONFIG_IP_DCCP_DEBUG 1103 bool dccp_debug; 1104 module_param(dccp_debug, bool, 0644); 1105 MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); 1106 1107 EXPORT_SYMBOL_GPL(dccp_debug); 1108 #endif 1109 1110 static int __init dccp_init(void) 1111 { 1112 unsigned long goal; 1113 unsigned long nr_pages = totalram_pages(); 1114 int ehash_order, bhash_order, i; 1115 int rc; 1116 1117 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > 1118 sizeof_field(struct sk_buff, cb)); 1119 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL); 1120 if (rc) 1121 goto out_fail; 1122 inet_hashinfo_init(&dccp_hashinfo); 1123 rc = inet_hashinfo2_init_mod(&dccp_hashinfo); 1124 if (rc) 1125 goto out_free_percpu; 1126 rc = -ENOBUFS; 1127 dccp_hashinfo.bind_bucket_cachep = 1128 kmem_cache_create("dccp_bind_bucket", 1129 sizeof(struct inet_bind_bucket), 0, 1130 SLAB_HWCACHE_ALIGN, NULL); 1131 if (!dccp_hashinfo.bind_bucket_cachep) 1132 goto out_free_hashinfo2; 1133 1134 /* 1135 * Size and allocate the main established and bind bucket 1136 * hash tables. 1137 * 1138 * The methodology is similar to that of the buffer cache. 1139 */ 1140 if (nr_pages >= (128 * 1024)) 1141 goal = nr_pages >> (21 - PAGE_SHIFT); 1142 else 1143 goal = nr_pages >> (23 - PAGE_SHIFT); 1144 1145 if (thash_entries) 1146 goal = (thash_entries * 1147 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; 1148 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) 1149 ; 1150 do { 1151 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / 1152 sizeof(struct inet_ehash_bucket); 1153 1154 while (hash_size & (hash_size - 1)) 1155 hash_size--; 1156 dccp_hashinfo.ehash_mask = hash_size - 1; 1157 dccp_hashinfo.ehash = (struct inet_ehash_bucket *) 1158 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); 1159 } while (!dccp_hashinfo.ehash && --ehash_order > 0); 1160 1161 if (!dccp_hashinfo.ehash) { 1162 DCCP_CRIT("Failed to allocate DCCP established hash table"); 1163 goto out_free_bind_bucket_cachep; 1164 } 1165 1166 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) 1167 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); 1168 1169 if (inet_ehash_locks_alloc(&dccp_hashinfo)) 1170 goto out_free_dccp_ehash; 1171 1172 bhash_order = ehash_order; 1173 1174 do { 1175 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / 1176 sizeof(struct inet_bind_hashbucket); 1177 if ((dccp_hashinfo.bhash_size > (64 * 1024)) && 1178 bhash_order > 0) 1179 continue; 1180 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) 1181 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); 1182 } while (!dccp_hashinfo.bhash && --bhash_order >= 0); 1183 1184 if (!dccp_hashinfo.bhash) { 1185 DCCP_CRIT("Failed to allocate DCCP bind hash table"); 1186 goto out_free_dccp_locks; 1187 } 1188 1189 for (i = 0; i < dccp_hashinfo.bhash_size; i++) { 1190 spin_lock_init(&dccp_hashinfo.bhash[i].lock); 1191 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); 1192 } 1193 1194 rc = dccp_mib_init(); 1195 if (rc) 1196 goto out_free_dccp_bhash; 1197 1198 rc = dccp_ackvec_init(); 1199 if (rc) 1200 goto out_free_dccp_mib; 1201 1202 rc = dccp_sysctl_init(); 1203 if (rc) 1204 goto out_ackvec_exit; 1205 1206 rc = ccid_initialize_builtins(); 1207 if (rc) 1208 goto out_sysctl_exit; 1209 1210 dccp_timestamping_init(); 1211 1212 return 0; 1213 1214 out_sysctl_exit: 1215 dccp_sysctl_exit(); 1216 out_ackvec_exit: 1217 dccp_ackvec_exit(); 1218 out_free_dccp_mib: 1219 dccp_mib_exit(); 1220 out_free_dccp_bhash: 1221 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); 1222 out_free_dccp_locks: 1223 inet_ehash_locks_free(&dccp_hashinfo); 1224 out_free_dccp_ehash: 1225 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); 1226 out_free_bind_bucket_cachep: 1227 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1228 out_free_hashinfo2: 1229 inet_hashinfo2_free_mod(&dccp_hashinfo); 1230 out_free_percpu: 1231 percpu_counter_destroy(&dccp_orphan_count); 1232 out_fail: 1233 dccp_hashinfo.bhash = NULL; 1234 dccp_hashinfo.ehash = NULL; 1235 dccp_hashinfo.bind_bucket_cachep = NULL; 1236 return rc; 1237 } 1238 1239 static void __exit dccp_fini(void) 1240 { 1241 ccid_cleanup_builtins(); 1242 dccp_mib_exit(); 1243 free_pages((unsigned long)dccp_hashinfo.bhash, 1244 get_order(dccp_hashinfo.bhash_size * 1245 sizeof(struct inet_bind_hashbucket))); 1246 free_pages((unsigned long)dccp_hashinfo.ehash, 1247 get_order((dccp_hashinfo.ehash_mask + 1) * 1248 sizeof(struct inet_ehash_bucket))); 1249 inet_ehash_locks_free(&dccp_hashinfo); 1250 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); 1251 dccp_ackvec_exit(); 1252 dccp_sysctl_exit(); 1253 inet_hashinfo2_free_mod(&dccp_hashinfo); 1254 percpu_counter_destroy(&dccp_orphan_count); 1255 } 1256 1257 module_init(dccp_init); 1258 module_exit(dccp_fini); 1259 1260 MODULE_LICENSE("GPL"); 1261 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>"); 1262 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); 1263