1 /* 2 * net/tipc/socket.c: TIPC socket API 3 * 4 * Copyright (c) 2001-2007, 2012 Ericsson AB 5 * Copyright (c) 2004-2008, 2010-2013, Wind River Systems 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the names of the copyright holders nor the names of its 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 20 * Alternatively, this software may be distributed under the terms of the 21 * GNU General Public License ("GPL") version 2 as published by the Free 22 * Software Foundation. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include "core.h" 38 #include "port.h" 39 40 #include <linux/export.h> 41 #include <net/sock.h> 42 43 #define SS_LISTENING -1 /* socket is listening */ 44 #define SS_READY -2 /* socket is connectionless */ 45 46 #define CONN_TIMEOUT_DEFAULT 8000 /* default connect timeout = 8s */ 47 48 struct tipc_sock { 49 struct sock sk; 50 struct tipc_port *p; 51 struct tipc_portid peer_name; 52 unsigned int conn_timeout; 53 }; 54 55 #define tipc_sk(sk) ((struct tipc_sock *)(sk)) 56 #define tipc_sk_port(sk) (tipc_sk(sk)->p) 57 58 #define tipc_rx_ready(sock) (!skb_queue_empty(&sock->sk->sk_receive_queue) || \ 59 (sock->state == SS_DISCONNECTING)) 60 61 static int backlog_rcv(struct sock *sk, struct sk_buff *skb); 62 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf); 63 static void wakeupdispatch(struct tipc_port *tport); 64 static void tipc_data_ready(struct sock *sk, int len); 65 static void tipc_write_space(struct sock *sk); 66 static int release(struct socket *sock); 67 static int accept(struct socket *sock, struct socket *new_sock, int flags); 68 69 static const struct proto_ops packet_ops; 70 static const struct proto_ops stream_ops; 71 static const struct proto_ops msg_ops; 72 73 static struct proto tipc_proto; 74 static struct proto tipc_proto_kern; 75 76 static int sockets_enabled; 77 78 /* 79 * Revised TIPC socket locking policy: 80 * 81 * Most socket operations take the standard socket lock when they start 82 * and hold it until they finish (or until they need to sleep). Acquiring 83 * this lock grants the owner exclusive access to the fields of the socket 84 * data structures, with the exception of the backlog queue. A few socket 85 * operations can be done without taking the socket lock because they only 86 * read socket information that never changes during the life of the socket. 87 * 88 * Socket operations may acquire the lock for the associated TIPC port if they 89 * need to perform an operation on the port. If any routine needs to acquire 90 * both the socket lock and the port lock it must take the socket lock first 91 * to avoid the risk of deadlock. 92 * 93 * The dispatcher handling incoming messages cannot grab the socket lock in 94 * the standard fashion, since invoked it runs at the BH level and cannot block. 95 * Instead, it checks to see if the socket lock is currently owned by someone, 96 * and either handles the message itself or adds it to the socket's backlog 97 * queue; in the latter case the queued message is processed once the process 98 * owning the socket lock releases it. 99 * 100 * NOTE: Releasing the socket lock while an operation is sleeping overcomes 101 * the problem of a blocked socket operation preventing any other operations 102 * from occurring. However, applications must be careful if they have 103 * multiple threads trying to send (or receive) on the same socket, as these 104 * operations might interfere with each other. For example, doing a connect 105 * and a receive at the same time might allow the receive to consume the 106 * ACK message meant for the connect. While additional work could be done 107 * to try and overcome this, it doesn't seem to be worthwhile at the present. 108 * 109 * NOTE: Releasing the socket lock while an operation is sleeping also ensures 110 * that another operation that must be performed in a non-blocking manner is 111 * not delayed for very long because the lock has already been taken. 112 * 113 * NOTE: This code assumes that certain fields of a port/socket pair are 114 * constant over its lifetime; such fields can be examined without taking 115 * the socket lock and/or port lock, and do not need to be re-read even 116 * after resuming processing after waiting. These fields include: 117 * - socket type 118 * - pointer to socket sk structure (aka tipc_sock structure) 119 * - pointer to port structure 120 * - port reference 121 */ 122 123 /** 124 * advance_rx_queue - discard first buffer in socket receive queue 125 * 126 * Caller must hold socket lock 127 */ 128 static void advance_rx_queue(struct sock *sk) 129 { 130 kfree_skb(__skb_dequeue(&sk->sk_receive_queue)); 131 } 132 133 /** 134 * reject_rx_queue - reject all buffers in socket receive queue 135 * 136 * Caller must hold socket lock 137 */ 138 static void reject_rx_queue(struct sock *sk) 139 { 140 struct sk_buff *buf; 141 142 while ((buf = __skb_dequeue(&sk->sk_receive_queue))) 143 tipc_reject_msg(buf, TIPC_ERR_NO_PORT); 144 } 145 146 /** 147 * tipc_sk_create - create a TIPC socket 148 * @net: network namespace (must be default network) 149 * @sock: pre-allocated socket structure 150 * @protocol: protocol indicator (must be 0) 151 * @kern: caused by kernel or by userspace? 152 * 153 * This routine creates additional data structures used by the TIPC socket, 154 * initializes them, and links them together. 155 * 156 * Returns 0 on success, errno otherwise 157 */ 158 static int tipc_sk_create(struct net *net, struct socket *sock, int protocol, 159 int kern) 160 { 161 const struct proto_ops *ops; 162 socket_state state; 163 struct sock *sk; 164 struct tipc_port *tp_ptr; 165 166 /* Validate arguments */ 167 if (unlikely(protocol != 0)) 168 return -EPROTONOSUPPORT; 169 170 switch (sock->type) { 171 case SOCK_STREAM: 172 ops = &stream_ops; 173 state = SS_UNCONNECTED; 174 break; 175 case SOCK_SEQPACKET: 176 ops = &packet_ops; 177 state = SS_UNCONNECTED; 178 break; 179 case SOCK_DGRAM: 180 case SOCK_RDM: 181 ops = &msg_ops; 182 state = SS_READY; 183 break; 184 default: 185 return -EPROTOTYPE; 186 } 187 188 /* Allocate socket's protocol area */ 189 if (!kern) 190 sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto); 191 else 192 sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto_kern); 193 194 if (sk == NULL) 195 return -ENOMEM; 196 197 /* Allocate TIPC port for socket to use */ 198 tp_ptr = tipc_createport(sk, &dispatch, &wakeupdispatch, 199 TIPC_LOW_IMPORTANCE); 200 if (unlikely(!tp_ptr)) { 201 sk_free(sk); 202 return -ENOMEM; 203 } 204 205 /* Finish initializing socket data structures */ 206 sock->ops = ops; 207 sock->state = state; 208 209 sock_init_data(sock, sk); 210 sk->sk_backlog_rcv = backlog_rcv; 211 sk->sk_rcvbuf = sysctl_tipc_rmem[1]; 212 sk->sk_data_ready = tipc_data_ready; 213 sk->sk_write_space = tipc_write_space; 214 tipc_sk(sk)->p = tp_ptr; 215 tipc_sk(sk)->conn_timeout = CONN_TIMEOUT_DEFAULT; 216 217 spin_unlock_bh(tp_ptr->lock); 218 219 if (sock->state == SS_READY) { 220 tipc_set_portunreturnable(tp_ptr->ref, 1); 221 if (sock->type == SOCK_DGRAM) 222 tipc_set_portunreliable(tp_ptr->ref, 1); 223 } 224 225 return 0; 226 } 227 228 /** 229 * tipc_sock_create_local - create TIPC socket from inside TIPC module 230 * @type: socket type - SOCK_RDM or SOCK_SEQPACKET 231 * 232 * We cannot use sock_creat_kern here because it bumps module user count. 233 * Since socket owner and creator is the same module we must make sure 234 * that module count remains zero for module local sockets, otherwise 235 * we cannot do rmmod. 236 * 237 * Returns 0 on success, errno otherwise 238 */ 239 int tipc_sock_create_local(int type, struct socket **res) 240 { 241 int rc; 242 243 rc = sock_create_lite(AF_TIPC, type, 0, res); 244 if (rc < 0) { 245 pr_err("Failed to create kernel socket\n"); 246 return rc; 247 } 248 tipc_sk_create(&init_net, *res, 0, 1); 249 250 return 0; 251 } 252 253 /** 254 * tipc_sock_release_local - release socket created by tipc_sock_create_local 255 * @sock: the socket to be released. 256 * 257 * Module reference count is not incremented when such sockets are created, 258 * so we must keep it from being decremented when they are released. 259 */ 260 void tipc_sock_release_local(struct socket *sock) 261 { 262 release(sock); 263 sock->ops = NULL; 264 sock_release(sock); 265 } 266 267 /** 268 * tipc_sock_accept_local - accept a connection on a socket created 269 * with tipc_sock_create_local. Use this function to avoid that 270 * module reference count is inadvertently incremented. 271 * 272 * @sock: the accepting socket 273 * @newsock: reference to the new socket to be created 274 * @flags: socket flags 275 */ 276 277 int tipc_sock_accept_local(struct socket *sock, struct socket **newsock, 278 int flags) 279 { 280 struct sock *sk = sock->sk; 281 int ret; 282 283 ret = sock_create_lite(sk->sk_family, sk->sk_type, 284 sk->sk_protocol, newsock); 285 if (ret < 0) 286 return ret; 287 288 ret = accept(sock, *newsock, flags); 289 if (ret < 0) { 290 sock_release(*newsock); 291 return ret; 292 } 293 (*newsock)->ops = sock->ops; 294 return ret; 295 } 296 297 /** 298 * release - destroy a TIPC socket 299 * @sock: socket to destroy 300 * 301 * This routine cleans up any messages that are still queued on the socket. 302 * For DGRAM and RDM socket types, all queued messages are rejected. 303 * For SEQPACKET and STREAM socket types, the first message is rejected 304 * and any others are discarded. (If the first message on a STREAM socket 305 * is partially-read, it is discarded and the next one is rejected instead.) 306 * 307 * NOTE: Rejected messages are not necessarily returned to the sender! They 308 * are returned or discarded according to the "destination droppable" setting 309 * specified for the message by the sender. 310 * 311 * Returns 0 on success, errno otherwise 312 */ 313 static int release(struct socket *sock) 314 { 315 struct sock *sk = sock->sk; 316 struct tipc_port *tport; 317 struct sk_buff *buf; 318 int res; 319 320 /* 321 * Exit if socket isn't fully initialized (occurs when a failed accept() 322 * releases a pre-allocated child socket that was never used) 323 */ 324 if (sk == NULL) 325 return 0; 326 327 tport = tipc_sk_port(sk); 328 lock_sock(sk); 329 330 /* 331 * Reject all unreceived messages, except on an active connection 332 * (which disconnects locally & sends a 'FIN+' to peer) 333 */ 334 while (sock->state != SS_DISCONNECTING) { 335 buf = __skb_dequeue(&sk->sk_receive_queue); 336 if (buf == NULL) 337 break; 338 if (TIPC_SKB_CB(buf)->handle != NULL) 339 kfree_skb(buf); 340 else { 341 if ((sock->state == SS_CONNECTING) || 342 (sock->state == SS_CONNECTED)) { 343 sock->state = SS_DISCONNECTING; 344 tipc_disconnect(tport->ref); 345 } 346 tipc_reject_msg(buf, TIPC_ERR_NO_PORT); 347 } 348 } 349 350 /* 351 * Delete TIPC port; this ensures no more messages are queued 352 * (also disconnects an active connection & sends a 'FIN-' to peer) 353 */ 354 res = tipc_deleteport(tport->ref); 355 356 /* Discard any remaining (connection-based) messages in receive queue */ 357 __skb_queue_purge(&sk->sk_receive_queue); 358 359 /* Reject any messages that accumulated in backlog queue */ 360 sock->state = SS_DISCONNECTING; 361 release_sock(sk); 362 363 sock_put(sk); 364 sock->sk = NULL; 365 366 return res; 367 } 368 369 /** 370 * bind - associate or disassocate TIPC name(s) with a socket 371 * @sock: socket structure 372 * @uaddr: socket address describing name(s) and desired operation 373 * @uaddr_len: size of socket address data structure 374 * 375 * Name and name sequence binding is indicated using a positive scope value; 376 * a negative scope value unbinds the specified name. Specifying no name 377 * (i.e. a socket address length of 0) unbinds all names from the socket. 378 * 379 * Returns 0 on success, errno otherwise 380 * 381 * NOTE: This routine doesn't need to take the socket lock since it doesn't 382 * access any non-constant socket information. 383 */ 384 static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len) 385 { 386 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; 387 u32 portref = tipc_sk_port(sock->sk)->ref; 388 389 if (unlikely(!uaddr_len)) 390 return tipc_withdraw(portref, 0, NULL); 391 392 if (uaddr_len < sizeof(struct sockaddr_tipc)) 393 return -EINVAL; 394 if (addr->family != AF_TIPC) 395 return -EAFNOSUPPORT; 396 397 if (addr->addrtype == TIPC_ADDR_NAME) 398 addr->addr.nameseq.upper = addr->addr.nameseq.lower; 399 else if (addr->addrtype != TIPC_ADDR_NAMESEQ) 400 return -EAFNOSUPPORT; 401 402 if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) && 403 (addr->addr.nameseq.type != TIPC_TOP_SRV) && 404 (addr->addr.nameseq.type != TIPC_CFG_SRV)) 405 return -EACCES; 406 407 return (addr->scope > 0) ? 408 tipc_publish(portref, addr->scope, &addr->addr.nameseq) : 409 tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq); 410 } 411 412 /** 413 * get_name - get port ID of socket or peer socket 414 * @sock: socket structure 415 * @uaddr: area for returned socket address 416 * @uaddr_len: area for returned length of socket address 417 * @peer: 0 = own ID, 1 = current peer ID, 2 = current/former peer ID 418 * 419 * Returns 0 on success, errno otherwise 420 * 421 * NOTE: This routine doesn't need to take the socket lock since it only 422 * accesses socket information that is unchanging (or which changes in 423 * a completely predictable manner). 424 */ 425 static int get_name(struct socket *sock, struct sockaddr *uaddr, 426 int *uaddr_len, int peer) 427 { 428 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; 429 struct tipc_sock *tsock = tipc_sk(sock->sk); 430 431 memset(addr, 0, sizeof(*addr)); 432 if (peer) { 433 if ((sock->state != SS_CONNECTED) && 434 ((peer != 2) || (sock->state != SS_DISCONNECTING))) 435 return -ENOTCONN; 436 addr->addr.id.ref = tsock->peer_name.ref; 437 addr->addr.id.node = tsock->peer_name.node; 438 } else { 439 addr->addr.id.ref = tsock->p->ref; 440 addr->addr.id.node = tipc_own_addr; 441 } 442 443 *uaddr_len = sizeof(*addr); 444 addr->addrtype = TIPC_ADDR_ID; 445 addr->family = AF_TIPC; 446 addr->scope = 0; 447 addr->addr.name.domain = 0; 448 449 return 0; 450 } 451 452 /** 453 * poll - read and possibly block on pollmask 454 * @file: file structure associated with the socket 455 * @sock: socket for which to calculate the poll bits 456 * @wait: ??? 457 * 458 * Returns pollmask value 459 * 460 * COMMENTARY: 461 * It appears that the usual socket locking mechanisms are not useful here 462 * since the pollmask info is potentially out-of-date the moment this routine 463 * exits. TCP and other protocols seem to rely on higher level poll routines 464 * to handle any preventable race conditions, so TIPC will do the same ... 465 * 466 * TIPC sets the returned events as follows: 467 * 468 * socket state flags set 469 * ------------ --------- 470 * unconnected no read flags 471 * POLLOUT if port is not congested 472 * 473 * connecting POLLIN/POLLRDNORM if ACK/NACK in rx queue 474 * no write flags 475 * 476 * connected POLLIN/POLLRDNORM if data in rx queue 477 * POLLOUT if port is not congested 478 * 479 * disconnecting POLLIN/POLLRDNORM/POLLHUP 480 * no write flags 481 * 482 * listening POLLIN if SYN in rx queue 483 * no write flags 484 * 485 * ready POLLIN/POLLRDNORM if data in rx queue 486 * [connectionless] POLLOUT (since port cannot be congested) 487 * 488 * IMPORTANT: The fact that a read or write operation is indicated does NOT 489 * imply that the operation will succeed, merely that it should be performed 490 * and will not block. 491 */ 492 static unsigned int poll(struct file *file, struct socket *sock, 493 poll_table *wait) 494 { 495 struct sock *sk = sock->sk; 496 u32 mask = 0; 497 498 sock_poll_wait(file, sk_sleep(sk), wait); 499 500 switch ((int)sock->state) { 501 case SS_UNCONNECTED: 502 if (!tipc_sk_port(sk)->congested) 503 mask |= POLLOUT; 504 break; 505 case SS_READY: 506 case SS_CONNECTED: 507 if (!tipc_sk_port(sk)->congested) 508 mask |= POLLOUT; 509 /* fall thru' */ 510 case SS_CONNECTING: 511 case SS_LISTENING: 512 if (!skb_queue_empty(&sk->sk_receive_queue)) 513 mask |= (POLLIN | POLLRDNORM); 514 break; 515 case SS_DISCONNECTING: 516 mask = (POLLIN | POLLRDNORM | POLLHUP); 517 break; 518 } 519 520 return mask; 521 } 522 523 /** 524 * dest_name_check - verify user is permitted to send to specified port name 525 * @dest: destination address 526 * @m: descriptor for message to be sent 527 * 528 * Prevents restricted configuration commands from being issued by 529 * unauthorized users. 530 * 531 * Returns 0 if permission is granted, otherwise errno 532 */ 533 static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m) 534 { 535 struct tipc_cfg_msg_hdr hdr; 536 537 if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES)) 538 return 0; 539 if (likely(dest->addr.name.name.type == TIPC_TOP_SRV)) 540 return 0; 541 if (likely(dest->addr.name.name.type != TIPC_CFG_SRV)) 542 return -EACCES; 543 544 if (!m->msg_iovlen || (m->msg_iov[0].iov_len < sizeof(hdr))) 545 return -EMSGSIZE; 546 if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr))) 547 return -EFAULT; 548 if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN))) 549 return -EACCES; 550 551 return 0; 552 } 553 554 /** 555 * send_msg - send message in connectionless manner 556 * @iocb: if NULL, indicates that socket lock is already held 557 * @sock: socket structure 558 * @m: message to send 559 * @total_len: length of message 560 * 561 * Message must have an destination specified explicitly. 562 * Used for SOCK_RDM and SOCK_DGRAM messages, 563 * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections. 564 * (Note: 'SYN+' is prohibited on SOCK_STREAM.) 565 * 566 * Returns the number of bytes sent on success, or errno otherwise 567 */ 568 static int send_msg(struct kiocb *iocb, struct socket *sock, 569 struct msghdr *m, size_t total_len) 570 { 571 struct sock *sk = sock->sk; 572 struct tipc_port *tport = tipc_sk_port(sk); 573 struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; 574 int needs_conn; 575 long timeout_val; 576 int res = -EINVAL; 577 578 if (unlikely(!dest)) 579 return -EDESTADDRREQ; 580 if (unlikely((m->msg_namelen < sizeof(*dest)) || 581 (dest->family != AF_TIPC))) 582 return -EINVAL; 583 if (total_len > TIPC_MAX_USER_MSG_SIZE) 584 return -EMSGSIZE; 585 586 if (iocb) 587 lock_sock(sk); 588 589 needs_conn = (sock->state != SS_READY); 590 if (unlikely(needs_conn)) { 591 if (sock->state == SS_LISTENING) { 592 res = -EPIPE; 593 goto exit; 594 } 595 if (sock->state != SS_UNCONNECTED) { 596 res = -EISCONN; 597 goto exit; 598 } 599 if (tport->published) { 600 res = -EOPNOTSUPP; 601 goto exit; 602 } 603 if (dest->addrtype == TIPC_ADDR_NAME) { 604 tport->conn_type = dest->addr.name.name.type; 605 tport->conn_instance = dest->addr.name.name.instance; 606 } 607 608 /* Abort any pending connection attempts (very unlikely) */ 609 reject_rx_queue(sk); 610 } 611 612 timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT); 613 614 do { 615 if (dest->addrtype == TIPC_ADDR_NAME) { 616 res = dest_name_check(dest, m); 617 if (res) 618 break; 619 res = tipc_send2name(tport->ref, 620 &dest->addr.name.name, 621 dest->addr.name.domain, 622 m->msg_iov, 623 total_len); 624 } else if (dest->addrtype == TIPC_ADDR_ID) { 625 res = tipc_send2port(tport->ref, 626 &dest->addr.id, 627 m->msg_iov, 628 total_len); 629 } else if (dest->addrtype == TIPC_ADDR_MCAST) { 630 if (needs_conn) { 631 res = -EOPNOTSUPP; 632 break; 633 } 634 res = dest_name_check(dest, m); 635 if (res) 636 break; 637 res = tipc_multicast(tport->ref, 638 &dest->addr.nameseq, 639 m->msg_iov, 640 total_len); 641 } 642 if (likely(res != -ELINKCONG)) { 643 if (needs_conn && (res >= 0)) 644 sock->state = SS_CONNECTING; 645 break; 646 } 647 if (timeout_val <= 0L) { 648 res = timeout_val ? timeout_val : -EWOULDBLOCK; 649 break; 650 } 651 release_sock(sk); 652 timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk), 653 !tport->congested, timeout_val); 654 lock_sock(sk); 655 } while (1); 656 657 exit: 658 if (iocb) 659 release_sock(sk); 660 return res; 661 } 662 663 /** 664 * send_packet - send a connection-oriented message 665 * @iocb: if NULL, indicates that socket lock is already held 666 * @sock: socket structure 667 * @m: message to send 668 * @total_len: length of message 669 * 670 * Used for SOCK_SEQPACKET messages and SOCK_STREAM data. 671 * 672 * Returns the number of bytes sent on success, or errno otherwise 673 */ 674 static int send_packet(struct kiocb *iocb, struct socket *sock, 675 struct msghdr *m, size_t total_len) 676 { 677 struct sock *sk = sock->sk; 678 struct tipc_port *tport = tipc_sk_port(sk); 679 struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; 680 long timeout_val; 681 int res; 682 683 /* Handle implied connection establishment */ 684 if (unlikely(dest)) 685 return send_msg(iocb, sock, m, total_len); 686 687 if (total_len > TIPC_MAX_USER_MSG_SIZE) 688 return -EMSGSIZE; 689 690 if (iocb) 691 lock_sock(sk); 692 693 timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT); 694 695 do { 696 if (unlikely(sock->state != SS_CONNECTED)) { 697 if (sock->state == SS_DISCONNECTING) 698 res = -EPIPE; 699 else 700 res = -ENOTCONN; 701 break; 702 } 703 704 res = tipc_send(tport->ref, m->msg_iov, total_len); 705 if (likely(res != -ELINKCONG)) 706 break; 707 if (timeout_val <= 0L) { 708 res = timeout_val ? timeout_val : -EWOULDBLOCK; 709 break; 710 } 711 release_sock(sk); 712 timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk), 713 (!tport->congested || !tport->connected), timeout_val); 714 lock_sock(sk); 715 } while (1); 716 717 if (iocb) 718 release_sock(sk); 719 return res; 720 } 721 722 /** 723 * send_stream - send stream-oriented data 724 * @iocb: (unused) 725 * @sock: socket structure 726 * @m: data to send 727 * @total_len: total length of data to be sent 728 * 729 * Used for SOCK_STREAM data. 730 * 731 * Returns the number of bytes sent on success (or partial success), 732 * or errno if no data sent 733 */ 734 static int send_stream(struct kiocb *iocb, struct socket *sock, 735 struct msghdr *m, size_t total_len) 736 { 737 struct sock *sk = sock->sk; 738 struct tipc_port *tport = tipc_sk_port(sk); 739 struct msghdr my_msg; 740 struct iovec my_iov; 741 struct iovec *curr_iov; 742 int curr_iovlen; 743 char __user *curr_start; 744 u32 hdr_size; 745 int curr_left; 746 int bytes_to_send; 747 int bytes_sent; 748 int res; 749 750 lock_sock(sk); 751 752 /* Handle special cases where there is no connection */ 753 if (unlikely(sock->state != SS_CONNECTED)) { 754 res = -ENOTCONN; 755 756 if (sock->state == SS_UNCONNECTED) 757 res = send_packet(NULL, sock, m, total_len); 758 else if (sock->state == SS_DISCONNECTING) 759 res = -EPIPE; 760 761 goto exit; 762 } 763 764 if (unlikely(m->msg_name)) { 765 res = -EISCONN; 766 goto exit; 767 } 768 769 if (total_len > (unsigned int)INT_MAX) { 770 res = -EMSGSIZE; 771 goto exit; 772 } 773 774 /* 775 * Send each iovec entry using one or more messages 776 * 777 * Note: This algorithm is good for the most likely case 778 * (i.e. one large iovec entry), but could be improved to pass sets 779 * of small iovec entries into send_packet(). 780 */ 781 curr_iov = m->msg_iov; 782 curr_iovlen = m->msg_iovlen; 783 my_msg.msg_iov = &my_iov; 784 my_msg.msg_iovlen = 1; 785 my_msg.msg_flags = m->msg_flags; 786 my_msg.msg_name = NULL; 787 bytes_sent = 0; 788 789 hdr_size = msg_hdr_sz(&tport->phdr); 790 791 while (curr_iovlen--) { 792 curr_start = curr_iov->iov_base; 793 curr_left = curr_iov->iov_len; 794 795 while (curr_left) { 796 bytes_to_send = tport->max_pkt - hdr_size; 797 if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE) 798 bytes_to_send = TIPC_MAX_USER_MSG_SIZE; 799 if (curr_left < bytes_to_send) 800 bytes_to_send = curr_left; 801 my_iov.iov_base = curr_start; 802 my_iov.iov_len = bytes_to_send; 803 res = send_packet(NULL, sock, &my_msg, bytes_to_send); 804 if (res < 0) { 805 if (bytes_sent) 806 res = bytes_sent; 807 goto exit; 808 } 809 curr_left -= bytes_to_send; 810 curr_start += bytes_to_send; 811 bytes_sent += bytes_to_send; 812 } 813 814 curr_iov++; 815 } 816 res = bytes_sent; 817 exit: 818 release_sock(sk); 819 return res; 820 } 821 822 /** 823 * auto_connect - complete connection setup to a remote port 824 * @sock: socket structure 825 * @msg: peer's response message 826 * 827 * Returns 0 on success, errno otherwise 828 */ 829 static int auto_connect(struct socket *sock, struct tipc_msg *msg) 830 { 831 struct tipc_sock *tsock = tipc_sk(sock->sk); 832 struct tipc_port *p_ptr; 833 834 tsock->peer_name.ref = msg_origport(msg); 835 tsock->peer_name.node = msg_orignode(msg); 836 p_ptr = tipc_port_deref(tsock->p->ref); 837 if (!p_ptr) 838 return -EINVAL; 839 840 __tipc_connect(tsock->p->ref, p_ptr, &tsock->peer_name); 841 842 if (msg_importance(msg) > TIPC_CRITICAL_IMPORTANCE) 843 return -EINVAL; 844 msg_set_importance(&p_ptr->phdr, (u32)msg_importance(msg)); 845 sock->state = SS_CONNECTED; 846 return 0; 847 } 848 849 /** 850 * set_orig_addr - capture sender's address for received message 851 * @m: descriptor for message info 852 * @msg: received message header 853 * 854 * Note: Address is not captured if not requested by receiver. 855 */ 856 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg) 857 { 858 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name; 859 860 if (addr) { 861 addr->family = AF_TIPC; 862 addr->addrtype = TIPC_ADDR_ID; 863 memset(&addr->addr, 0, sizeof(addr->addr)); 864 addr->addr.id.ref = msg_origport(msg); 865 addr->addr.id.node = msg_orignode(msg); 866 addr->addr.name.domain = 0; /* could leave uninitialized */ 867 addr->scope = 0; /* could leave uninitialized */ 868 m->msg_namelen = sizeof(struct sockaddr_tipc); 869 } 870 } 871 872 /** 873 * anc_data_recv - optionally capture ancillary data for received message 874 * @m: descriptor for message info 875 * @msg: received message header 876 * @tport: TIPC port associated with message 877 * 878 * Note: Ancillary data is not captured if not requested by receiver. 879 * 880 * Returns 0 if successful, otherwise errno 881 */ 882 static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg, 883 struct tipc_port *tport) 884 { 885 u32 anc_data[3]; 886 u32 err; 887 u32 dest_type; 888 int has_name; 889 int res; 890 891 if (likely(m->msg_controllen == 0)) 892 return 0; 893 894 /* Optionally capture errored message object(s) */ 895 err = msg ? msg_errcode(msg) : 0; 896 if (unlikely(err)) { 897 anc_data[0] = err; 898 anc_data[1] = msg_data_sz(msg); 899 res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data); 900 if (res) 901 return res; 902 if (anc_data[1]) { 903 res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1], 904 msg_data(msg)); 905 if (res) 906 return res; 907 } 908 } 909 910 /* Optionally capture message destination object */ 911 dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG; 912 switch (dest_type) { 913 case TIPC_NAMED_MSG: 914 has_name = 1; 915 anc_data[0] = msg_nametype(msg); 916 anc_data[1] = msg_namelower(msg); 917 anc_data[2] = msg_namelower(msg); 918 break; 919 case TIPC_MCAST_MSG: 920 has_name = 1; 921 anc_data[0] = msg_nametype(msg); 922 anc_data[1] = msg_namelower(msg); 923 anc_data[2] = msg_nameupper(msg); 924 break; 925 case TIPC_CONN_MSG: 926 has_name = (tport->conn_type != 0); 927 anc_data[0] = tport->conn_type; 928 anc_data[1] = tport->conn_instance; 929 anc_data[2] = tport->conn_instance; 930 break; 931 default: 932 has_name = 0; 933 } 934 if (has_name) { 935 res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data); 936 if (res) 937 return res; 938 } 939 940 return 0; 941 } 942 943 /** 944 * recv_msg - receive packet-oriented message 945 * @iocb: (unused) 946 * @m: descriptor for message info 947 * @buf_len: total size of user buffer area 948 * @flags: receive flags 949 * 950 * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages. 951 * If the complete message doesn't fit in user area, truncate it. 952 * 953 * Returns size of returned message data, errno otherwise 954 */ 955 static int recv_msg(struct kiocb *iocb, struct socket *sock, 956 struct msghdr *m, size_t buf_len, int flags) 957 { 958 struct sock *sk = sock->sk; 959 struct tipc_port *tport = tipc_sk_port(sk); 960 struct sk_buff *buf; 961 struct tipc_msg *msg; 962 long timeout; 963 unsigned int sz; 964 u32 err; 965 int res; 966 967 /* Catch invalid receive requests */ 968 if (unlikely(!buf_len)) 969 return -EINVAL; 970 971 lock_sock(sk); 972 973 if (unlikely(sock->state == SS_UNCONNECTED)) { 974 res = -ENOTCONN; 975 goto exit; 976 } 977 978 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 979 restart: 980 981 /* Look for a message in receive queue; wait if necessary */ 982 while (skb_queue_empty(&sk->sk_receive_queue)) { 983 if (sock->state == SS_DISCONNECTING) { 984 res = -ENOTCONN; 985 goto exit; 986 } 987 if (timeout <= 0L) { 988 res = timeout ? timeout : -EWOULDBLOCK; 989 goto exit; 990 } 991 release_sock(sk); 992 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 993 tipc_rx_ready(sock), 994 timeout); 995 lock_sock(sk); 996 } 997 998 /* Look at first message in receive queue */ 999 buf = skb_peek(&sk->sk_receive_queue); 1000 msg = buf_msg(buf); 1001 sz = msg_data_sz(msg); 1002 err = msg_errcode(msg); 1003 1004 /* Discard an empty non-errored message & try again */ 1005 if ((!sz) && (!err)) { 1006 advance_rx_queue(sk); 1007 goto restart; 1008 } 1009 1010 /* Capture sender's address (optional) */ 1011 set_orig_addr(m, msg); 1012 1013 /* Capture ancillary data (optional) */ 1014 res = anc_data_recv(m, msg, tport); 1015 if (res) 1016 goto exit; 1017 1018 /* Capture message data (if valid) & compute return value (always) */ 1019 if (!err) { 1020 if (unlikely(buf_len < sz)) { 1021 sz = buf_len; 1022 m->msg_flags |= MSG_TRUNC; 1023 } 1024 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg), 1025 m->msg_iov, sz); 1026 if (res) 1027 goto exit; 1028 res = sz; 1029 } else { 1030 if ((sock->state == SS_READY) || 1031 ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)) 1032 res = 0; 1033 else 1034 res = -ECONNRESET; 1035 } 1036 1037 /* Consume received message (optional) */ 1038 if (likely(!(flags & MSG_PEEK))) { 1039 if ((sock->state != SS_READY) && 1040 (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1041 tipc_acknowledge(tport->ref, tport->conn_unacked); 1042 advance_rx_queue(sk); 1043 } 1044 exit: 1045 release_sock(sk); 1046 return res; 1047 } 1048 1049 /** 1050 * recv_stream - receive stream-oriented data 1051 * @iocb: (unused) 1052 * @m: descriptor for message info 1053 * @buf_len: total size of user buffer area 1054 * @flags: receive flags 1055 * 1056 * Used for SOCK_STREAM messages only. If not enough data is available 1057 * will optionally wait for more; never truncates data. 1058 * 1059 * Returns size of returned message data, errno otherwise 1060 */ 1061 static int recv_stream(struct kiocb *iocb, struct socket *sock, 1062 struct msghdr *m, size_t buf_len, int flags) 1063 { 1064 struct sock *sk = sock->sk; 1065 struct tipc_port *tport = tipc_sk_port(sk); 1066 struct sk_buff *buf; 1067 struct tipc_msg *msg; 1068 long timeout; 1069 unsigned int sz; 1070 int sz_to_copy, target, needed; 1071 int sz_copied = 0; 1072 u32 err; 1073 int res = 0; 1074 1075 /* Catch invalid receive attempts */ 1076 if (unlikely(!buf_len)) 1077 return -EINVAL; 1078 1079 lock_sock(sk); 1080 1081 if (unlikely((sock->state == SS_UNCONNECTED))) { 1082 res = -ENOTCONN; 1083 goto exit; 1084 } 1085 1086 target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len); 1087 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1088 1089 restart: 1090 /* Look for a message in receive queue; wait if necessary */ 1091 while (skb_queue_empty(&sk->sk_receive_queue)) { 1092 if (sock->state == SS_DISCONNECTING) { 1093 res = -ENOTCONN; 1094 goto exit; 1095 } 1096 if (timeout <= 0L) { 1097 res = timeout ? timeout : -EWOULDBLOCK; 1098 goto exit; 1099 } 1100 release_sock(sk); 1101 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 1102 tipc_rx_ready(sock), 1103 timeout); 1104 lock_sock(sk); 1105 } 1106 1107 /* Look at first message in receive queue */ 1108 buf = skb_peek(&sk->sk_receive_queue); 1109 msg = buf_msg(buf); 1110 sz = msg_data_sz(msg); 1111 err = msg_errcode(msg); 1112 1113 /* Discard an empty non-errored message & try again */ 1114 if ((!sz) && (!err)) { 1115 advance_rx_queue(sk); 1116 goto restart; 1117 } 1118 1119 /* Optionally capture sender's address & ancillary data of first msg */ 1120 if (sz_copied == 0) { 1121 set_orig_addr(m, msg); 1122 res = anc_data_recv(m, msg, tport); 1123 if (res) 1124 goto exit; 1125 } 1126 1127 /* Capture message data (if valid) & compute return value (always) */ 1128 if (!err) { 1129 u32 offset = (u32)(unsigned long)(TIPC_SKB_CB(buf)->handle); 1130 1131 sz -= offset; 1132 needed = (buf_len - sz_copied); 1133 sz_to_copy = (sz <= needed) ? sz : needed; 1134 1135 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg) + offset, 1136 m->msg_iov, sz_to_copy); 1137 if (res) 1138 goto exit; 1139 1140 sz_copied += sz_to_copy; 1141 1142 if (sz_to_copy < sz) { 1143 if (!(flags & MSG_PEEK)) 1144 TIPC_SKB_CB(buf)->handle = 1145 (void *)(unsigned long)(offset + sz_to_copy); 1146 goto exit; 1147 } 1148 } else { 1149 if (sz_copied != 0) 1150 goto exit; /* can't add error msg to valid data */ 1151 1152 if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control) 1153 res = 0; 1154 else 1155 res = -ECONNRESET; 1156 } 1157 1158 /* Consume received message (optional) */ 1159 if (likely(!(flags & MSG_PEEK))) { 1160 if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1161 tipc_acknowledge(tport->ref, tport->conn_unacked); 1162 advance_rx_queue(sk); 1163 } 1164 1165 /* Loop around if more data is required */ 1166 if ((sz_copied < buf_len) && /* didn't get all requested data */ 1167 (!skb_queue_empty(&sk->sk_receive_queue) || 1168 (sz_copied < target)) && /* and more is ready or required */ 1169 (!(flags & MSG_PEEK)) && /* and aren't just peeking at data */ 1170 (!err)) /* and haven't reached a FIN */ 1171 goto restart; 1172 1173 exit: 1174 release_sock(sk); 1175 return sz_copied ? sz_copied : res; 1176 } 1177 1178 /** 1179 * tipc_write_space - wake up thread if port congestion is released 1180 * @sk: socket 1181 */ 1182 static void tipc_write_space(struct sock *sk) 1183 { 1184 struct socket_wq *wq; 1185 1186 rcu_read_lock(); 1187 wq = rcu_dereference(sk->sk_wq); 1188 if (wq_has_sleeper(wq)) 1189 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | 1190 POLLWRNORM | POLLWRBAND); 1191 rcu_read_unlock(); 1192 } 1193 1194 /** 1195 * tipc_data_ready - wake up threads to indicate messages have been received 1196 * @sk: socket 1197 * @len: the length of messages 1198 */ 1199 static void tipc_data_ready(struct sock *sk, int len) 1200 { 1201 struct socket_wq *wq; 1202 1203 rcu_read_lock(); 1204 wq = rcu_dereference(sk->sk_wq); 1205 if (wq_has_sleeper(wq)) 1206 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | 1207 POLLRDNORM | POLLRDBAND); 1208 rcu_read_unlock(); 1209 } 1210 1211 /** 1212 * filter_connect - Handle all incoming messages for a connection-based socket 1213 * @tsock: TIPC socket 1214 * @msg: message 1215 * 1216 * Returns TIPC error status code and socket error status code 1217 * once it encounters some errors 1218 */ 1219 static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf) 1220 { 1221 struct socket *sock = tsock->sk.sk_socket; 1222 struct tipc_msg *msg = buf_msg(*buf); 1223 struct sock *sk = &tsock->sk; 1224 u32 retval = TIPC_ERR_NO_PORT; 1225 int res; 1226 1227 if (msg_mcast(msg)) 1228 return retval; 1229 1230 switch ((int)sock->state) { 1231 case SS_CONNECTED: 1232 /* Accept only connection-based messages sent by peer */ 1233 if (msg_connected(msg) && tipc_port_peer_msg(tsock->p, msg)) { 1234 if (unlikely(msg_errcode(msg))) { 1235 sock->state = SS_DISCONNECTING; 1236 __tipc_disconnect(tsock->p); 1237 } 1238 retval = TIPC_OK; 1239 } 1240 break; 1241 case SS_CONNECTING: 1242 /* Accept only ACK or NACK message */ 1243 if (unlikely(msg_errcode(msg))) { 1244 sock->state = SS_DISCONNECTING; 1245 sk->sk_err = ECONNREFUSED; 1246 retval = TIPC_OK; 1247 break; 1248 } 1249 1250 if (unlikely(!msg_connected(msg))) 1251 break; 1252 1253 res = auto_connect(sock, msg); 1254 if (res) { 1255 sock->state = SS_DISCONNECTING; 1256 sk->sk_err = -res; 1257 retval = TIPC_OK; 1258 break; 1259 } 1260 1261 /* If an incoming message is an 'ACK-', it should be 1262 * discarded here because it doesn't contain useful 1263 * data. In addition, we should try to wake up 1264 * connect() routine if sleeping. 1265 */ 1266 if (msg_data_sz(msg) == 0) { 1267 kfree_skb(*buf); 1268 *buf = NULL; 1269 if (waitqueue_active(sk_sleep(sk))) 1270 wake_up_interruptible(sk_sleep(sk)); 1271 } 1272 retval = TIPC_OK; 1273 break; 1274 case SS_LISTENING: 1275 case SS_UNCONNECTED: 1276 /* Accept only SYN message */ 1277 if (!msg_connected(msg) && !(msg_errcode(msg))) 1278 retval = TIPC_OK; 1279 break; 1280 case SS_DISCONNECTING: 1281 break; 1282 default: 1283 pr_err("Unknown socket state %u\n", sock->state); 1284 } 1285 return retval; 1286 } 1287 1288 /** 1289 * rcvbuf_limit - get proper overload limit of socket receive queue 1290 * @sk: socket 1291 * @buf: message 1292 * 1293 * For all connection oriented messages, irrespective of importance, 1294 * the default overload value (i.e. 67MB) is set as limit. 1295 * 1296 * For all connectionless messages, by default new queue limits are 1297 * as belows: 1298 * 1299 * TIPC_LOW_IMPORTANCE (4 MB) 1300 * TIPC_MEDIUM_IMPORTANCE (8 MB) 1301 * TIPC_HIGH_IMPORTANCE (16 MB) 1302 * TIPC_CRITICAL_IMPORTANCE (32 MB) 1303 * 1304 * Returns overload limit according to corresponding message importance 1305 */ 1306 static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf) 1307 { 1308 struct tipc_msg *msg = buf_msg(buf); 1309 1310 if (msg_connected(msg)) 1311 return sysctl_tipc_rmem[2]; 1312 1313 return sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE << 1314 msg_importance(msg); 1315 } 1316 1317 /** 1318 * filter_rcv - validate incoming message 1319 * @sk: socket 1320 * @buf: message 1321 * 1322 * Enqueues message on receive queue if acceptable; optionally handles 1323 * disconnect indication for a connected socket. 1324 * 1325 * Called with socket lock already taken; port lock may also be taken. 1326 * 1327 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1328 */ 1329 static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) 1330 { 1331 struct socket *sock = sk->sk_socket; 1332 struct tipc_msg *msg = buf_msg(buf); 1333 unsigned int limit = rcvbuf_limit(sk, buf); 1334 u32 res = TIPC_OK; 1335 1336 /* Reject message if it is wrong sort of message for socket */ 1337 if (msg_type(msg) > TIPC_DIRECT_MSG) 1338 return TIPC_ERR_NO_PORT; 1339 1340 if (sock->state == SS_READY) { 1341 if (msg_connected(msg)) 1342 return TIPC_ERR_NO_PORT; 1343 } else { 1344 res = filter_connect(tipc_sk(sk), &buf); 1345 if (res != TIPC_OK || buf == NULL) 1346 return res; 1347 } 1348 1349 /* Reject message if there isn't room to queue it */ 1350 if (sk_rmem_alloc_get(sk) + buf->truesize >= limit) 1351 return TIPC_ERR_OVERLOAD; 1352 1353 /* Enqueue message */ 1354 TIPC_SKB_CB(buf)->handle = NULL; 1355 __skb_queue_tail(&sk->sk_receive_queue, buf); 1356 skb_set_owner_r(buf, sk); 1357 1358 sk->sk_data_ready(sk, 0); 1359 return TIPC_OK; 1360 } 1361 1362 /** 1363 * backlog_rcv - handle incoming message from backlog queue 1364 * @sk: socket 1365 * @buf: message 1366 * 1367 * Caller must hold socket lock, but not port lock. 1368 * 1369 * Returns 0 1370 */ 1371 static int backlog_rcv(struct sock *sk, struct sk_buff *buf) 1372 { 1373 u32 res; 1374 1375 res = filter_rcv(sk, buf); 1376 if (res) 1377 tipc_reject_msg(buf, res); 1378 return 0; 1379 } 1380 1381 /** 1382 * dispatch - handle incoming message 1383 * @tport: TIPC port that received message 1384 * @buf: message 1385 * 1386 * Called with port lock already taken. 1387 * 1388 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1389 */ 1390 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf) 1391 { 1392 struct sock *sk = tport->sk; 1393 u32 res; 1394 1395 /* 1396 * Process message if socket is unlocked; otherwise add to backlog queue 1397 * 1398 * This code is based on sk_receive_skb(), but must be distinct from it 1399 * since a TIPC-specific filter/reject mechanism is utilized 1400 */ 1401 bh_lock_sock(sk); 1402 if (!sock_owned_by_user(sk)) { 1403 res = filter_rcv(sk, buf); 1404 } else { 1405 if (sk_add_backlog(sk, buf, rcvbuf_limit(sk, buf))) 1406 res = TIPC_ERR_OVERLOAD; 1407 else 1408 res = TIPC_OK; 1409 } 1410 bh_unlock_sock(sk); 1411 1412 return res; 1413 } 1414 1415 /** 1416 * wakeupdispatch - wake up port after congestion 1417 * @tport: port to wakeup 1418 * 1419 * Called with port lock already taken. 1420 */ 1421 static void wakeupdispatch(struct tipc_port *tport) 1422 { 1423 struct sock *sk = tport->sk; 1424 1425 sk->sk_write_space(sk); 1426 } 1427 1428 /** 1429 * connect - establish a connection to another TIPC port 1430 * @sock: socket structure 1431 * @dest: socket address for destination port 1432 * @destlen: size of socket address data structure 1433 * @flags: file-related flags associated with socket 1434 * 1435 * Returns 0 on success, errno otherwise 1436 */ 1437 static int connect(struct socket *sock, struct sockaddr *dest, int destlen, 1438 int flags) 1439 { 1440 struct sock *sk = sock->sk; 1441 struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest; 1442 struct msghdr m = {NULL,}; 1443 unsigned int timeout; 1444 int res; 1445 1446 lock_sock(sk); 1447 1448 /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */ 1449 if (sock->state == SS_READY) { 1450 res = -EOPNOTSUPP; 1451 goto exit; 1452 } 1453 1454 /* 1455 * Reject connection attempt using multicast address 1456 * 1457 * Note: send_msg() validates the rest of the address fields, 1458 * so there's no need to do it here 1459 */ 1460 if (dst->addrtype == TIPC_ADDR_MCAST) { 1461 res = -EINVAL; 1462 goto exit; 1463 } 1464 1465 timeout = (flags & O_NONBLOCK) ? 0 : tipc_sk(sk)->conn_timeout; 1466 1467 switch (sock->state) { 1468 case SS_UNCONNECTED: 1469 /* Send a 'SYN-' to destination */ 1470 m.msg_name = dest; 1471 m.msg_namelen = destlen; 1472 1473 /* If connect is in non-blocking case, set MSG_DONTWAIT to 1474 * indicate send_msg() is never blocked. 1475 */ 1476 if (!timeout) 1477 m.msg_flags = MSG_DONTWAIT; 1478 1479 res = send_msg(NULL, sock, &m, 0); 1480 if ((res < 0) && (res != -EWOULDBLOCK)) 1481 goto exit; 1482 1483 /* Just entered SS_CONNECTING state; the only 1484 * difference is that return value in non-blocking 1485 * case is EINPROGRESS, rather than EALREADY. 1486 */ 1487 res = -EINPROGRESS; 1488 break; 1489 case SS_CONNECTING: 1490 res = -EALREADY; 1491 break; 1492 case SS_CONNECTED: 1493 res = -EISCONN; 1494 break; 1495 default: 1496 res = -EINVAL; 1497 goto exit; 1498 } 1499 1500 if (sock->state == SS_CONNECTING) { 1501 if (!timeout) 1502 goto exit; 1503 1504 /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */ 1505 release_sock(sk); 1506 res = wait_event_interruptible_timeout(*sk_sleep(sk), 1507 sock->state != SS_CONNECTING, 1508 timeout ? (long)msecs_to_jiffies(timeout) 1509 : MAX_SCHEDULE_TIMEOUT); 1510 if (res <= 0) { 1511 if (res == 0) 1512 res = -ETIMEDOUT; 1513 return res; 1514 } 1515 lock_sock(sk); 1516 } 1517 1518 if (unlikely(sock->state == SS_DISCONNECTING)) 1519 res = sock_error(sk); 1520 else 1521 res = 0; 1522 1523 exit: 1524 release_sock(sk); 1525 return res; 1526 } 1527 1528 /** 1529 * listen - allow socket to listen for incoming connections 1530 * @sock: socket structure 1531 * @len: (unused) 1532 * 1533 * Returns 0 on success, errno otherwise 1534 */ 1535 static int listen(struct socket *sock, int len) 1536 { 1537 struct sock *sk = sock->sk; 1538 int res; 1539 1540 lock_sock(sk); 1541 1542 if (sock->state != SS_UNCONNECTED) 1543 res = -EINVAL; 1544 else { 1545 sock->state = SS_LISTENING; 1546 res = 0; 1547 } 1548 1549 release_sock(sk); 1550 return res; 1551 } 1552 1553 /** 1554 * accept - wait for connection request 1555 * @sock: listening socket 1556 * @newsock: new socket that is to be connected 1557 * @flags: file-related flags associated with socket 1558 * 1559 * Returns 0 on success, errno otherwise 1560 */ 1561 static int accept(struct socket *sock, struct socket *new_sock, int flags) 1562 { 1563 struct sock *new_sk, *sk = sock->sk; 1564 struct sk_buff *buf; 1565 struct tipc_sock *new_tsock; 1566 struct tipc_port *new_tport; 1567 struct tipc_msg *msg; 1568 u32 new_ref; 1569 1570 int res; 1571 1572 lock_sock(sk); 1573 1574 if (sock->state != SS_LISTENING) { 1575 res = -EINVAL; 1576 goto exit; 1577 } 1578 1579 while (skb_queue_empty(&sk->sk_receive_queue)) { 1580 if (flags & O_NONBLOCK) { 1581 res = -EWOULDBLOCK; 1582 goto exit; 1583 } 1584 release_sock(sk); 1585 res = wait_event_interruptible(*sk_sleep(sk), 1586 (!skb_queue_empty(&sk->sk_receive_queue))); 1587 lock_sock(sk); 1588 if (res) 1589 goto exit; 1590 } 1591 1592 buf = skb_peek(&sk->sk_receive_queue); 1593 1594 res = tipc_sk_create(sock_net(sock->sk), new_sock, 0, 1); 1595 if (res) 1596 goto exit; 1597 1598 new_sk = new_sock->sk; 1599 new_tsock = tipc_sk(new_sk); 1600 new_tport = new_tsock->p; 1601 new_ref = new_tport->ref; 1602 msg = buf_msg(buf); 1603 1604 /* we lock on new_sk; but lockdep sees the lock on sk */ 1605 lock_sock_nested(new_sk, SINGLE_DEPTH_NESTING); 1606 1607 /* 1608 * Reject any stray messages received by new socket 1609 * before the socket lock was taken (very, very unlikely) 1610 */ 1611 reject_rx_queue(new_sk); 1612 1613 /* Connect new socket to it's peer */ 1614 new_tsock->peer_name.ref = msg_origport(msg); 1615 new_tsock->peer_name.node = msg_orignode(msg); 1616 tipc_connect(new_ref, &new_tsock->peer_name); 1617 new_sock->state = SS_CONNECTED; 1618 1619 tipc_set_portimportance(new_ref, msg_importance(msg)); 1620 if (msg_named(msg)) { 1621 new_tport->conn_type = msg_nametype(msg); 1622 new_tport->conn_instance = msg_nameinst(msg); 1623 } 1624 1625 /* 1626 * Respond to 'SYN-' by discarding it & returning 'ACK'-. 1627 * Respond to 'SYN+' by queuing it on new socket. 1628 */ 1629 if (!msg_data_sz(msg)) { 1630 struct msghdr m = {NULL,}; 1631 1632 advance_rx_queue(sk); 1633 send_packet(NULL, new_sock, &m, 0); 1634 } else { 1635 __skb_dequeue(&sk->sk_receive_queue); 1636 __skb_queue_head(&new_sk->sk_receive_queue, buf); 1637 skb_set_owner_r(buf, new_sk); 1638 } 1639 release_sock(new_sk); 1640 1641 exit: 1642 release_sock(sk); 1643 return res; 1644 } 1645 1646 /** 1647 * shutdown - shutdown socket connection 1648 * @sock: socket structure 1649 * @how: direction to close (must be SHUT_RDWR) 1650 * 1651 * Terminates connection (if necessary), then purges socket's receive queue. 1652 * 1653 * Returns 0 on success, errno otherwise 1654 */ 1655 static int shutdown(struct socket *sock, int how) 1656 { 1657 struct sock *sk = sock->sk; 1658 struct tipc_port *tport = tipc_sk_port(sk); 1659 struct sk_buff *buf; 1660 int res; 1661 1662 if (how != SHUT_RDWR) 1663 return -EINVAL; 1664 1665 lock_sock(sk); 1666 1667 switch (sock->state) { 1668 case SS_CONNECTING: 1669 case SS_CONNECTED: 1670 1671 restart: 1672 /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */ 1673 buf = __skb_dequeue(&sk->sk_receive_queue); 1674 if (buf) { 1675 if (TIPC_SKB_CB(buf)->handle != NULL) { 1676 kfree_skb(buf); 1677 goto restart; 1678 } 1679 tipc_disconnect(tport->ref); 1680 tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); 1681 } else { 1682 tipc_shutdown(tport->ref); 1683 } 1684 1685 sock->state = SS_DISCONNECTING; 1686 1687 /* fall through */ 1688 1689 case SS_DISCONNECTING: 1690 1691 /* Discard any unreceived messages */ 1692 __skb_queue_purge(&sk->sk_receive_queue); 1693 1694 /* Wake up anyone sleeping in poll */ 1695 sk->sk_state_change(sk); 1696 res = 0; 1697 break; 1698 1699 default: 1700 res = -ENOTCONN; 1701 } 1702 1703 release_sock(sk); 1704 return res; 1705 } 1706 1707 /** 1708 * setsockopt - set socket option 1709 * @sock: socket structure 1710 * @lvl: option level 1711 * @opt: option identifier 1712 * @ov: pointer to new option value 1713 * @ol: length of option value 1714 * 1715 * For stream sockets only, accepts and ignores all IPPROTO_TCP options 1716 * (to ease compatibility). 1717 * 1718 * Returns 0 on success, errno otherwise 1719 */ 1720 static int setsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1721 unsigned int ol) 1722 { 1723 struct sock *sk = sock->sk; 1724 struct tipc_port *tport = tipc_sk_port(sk); 1725 u32 value; 1726 int res; 1727 1728 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1729 return 0; 1730 if (lvl != SOL_TIPC) 1731 return -ENOPROTOOPT; 1732 if (ol < sizeof(value)) 1733 return -EINVAL; 1734 res = get_user(value, (u32 __user *)ov); 1735 if (res) 1736 return res; 1737 1738 lock_sock(sk); 1739 1740 switch (opt) { 1741 case TIPC_IMPORTANCE: 1742 res = tipc_set_portimportance(tport->ref, value); 1743 break; 1744 case TIPC_SRC_DROPPABLE: 1745 if (sock->type != SOCK_STREAM) 1746 res = tipc_set_portunreliable(tport->ref, value); 1747 else 1748 res = -ENOPROTOOPT; 1749 break; 1750 case TIPC_DEST_DROPPABLE: 1751 res = tipc_set_portunreturnable(tport->ref, value); 1752 break; 1753 case TIPC_CONN_TIMEOUT: 1754 tipc_sk(sk)->conn_timeout = value; 1755 /* no need to set "res", since already 0 at this point */ 1756 break; 1757 default: 1758 res = -EINVAL; 1759 } 1760 1761 release_sock(sk); 1762 1763 return res; 1764 } 1765 1766 /** 1767 * getsockopt - get socket option 1768 * @sock: socket structure 1769 * @lvl: option level 1770 * @opt: option identifier 1771 * @ov: receptacle for option value 1772 * @ol: receptacle for length of option value 1773 * 1774 * For stream sockets only, returns 0 length result for all IPPROTO_TCP options 1775 * (to ease compatibility). 1776 * 1777 * Returns 0 on success, errno otherwise 1778 */ 1779 static int getsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1780 int __user *ol) 1781 { 1782 struct sock *sk = sock->sk; 1783 struct tipc_port *tport = tipc_sk_port(sk); 1784 int len; 1785 u32 value; 1786 int res; 1787 1788 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1789 return put_user(0, ol); 1790 if (lvl != SOL_TIPC) 1791 return -ENOPROTOOPT; 1792 res = get_user(len, ol); 1793 if (res) 1794 return res; 1795 1796 lock_sock(sk); 1797 1798 switch (opt) { 1799 case TIPC_IMPORTANCE: 1800 res = tipc_portimportance(tport->ref, &value); 1801 break; 1802 case TIPC_SRC_DROPPABLE: 1803 res = tipc_portunreliable(tport->ref, &value); 1804 break; 1805 case TIPC_DEST_DROPPABLE: 1806 res = tipc_portunreturnable(tport->ref, &value); 1807 break; 1808 case TIPC_CONN_TIMEOUT: 1809 value = tipc_sk(sk)->conn_timeout; 1810 /* no need to set "res", since already 0 at this point */ 1811 break; 1812 case TIPC_NODE_RECVQ_DEPTH: 1813 value = 0; /* was tipc_queue_size, now obsolete */ 1814 break; 1815 case TIPC_SOCK_RECVQ_DEPTH: 1816 value = skb_queue_len(&sk->sk_receive_queue); 1817 break; 1818 default: 1819 res = -EINVAL; 1820 } 1821 1822 release_sock(sk); 1823 1824 if (res) 1825 return res; /* "get" failed */ 1826 1827 if (len < sizeof(value)) 1828 return -EINVAL; 1829 1830 if (copy_to_user(ov, &value, sizeof(value))) 1831 return -EFAULT; 1832 1833 return put_user(sizeof(value), ol); 1834 } 1835 1836 /* Protocol switches for the various types of TIPC sockets */ 1837 1838 static const struct proto_ops msg_ops = { 1839 .owner = THIS_MODULE, 1840 .family = AF_TIPC, 1841 .release = release, 1842 .bind = bind, 1843 .connect = connect, 1844 .socketpair = sock_no_socketpair, 1845 .accept = sock_no_accept, 1846 .getname = get_name, 1847 .poll = poll, 1848 .ioctl = sock_no_ioctl, 1849 .listen = sock_no_listen, 1850 .shutdown = shutdown, 1851 .setsockopt = setsockopt, 1852 .getsockopt = getsockopt, 1853 .sendmsg = send_msg, 1854 .recvmsg = recv_msg, 1855 .mmap = sock_no_mmap, 1856 .sendpage = sock_no_sendpage 1857 }; 1858 1859 static const struct proto_ops packet_ops = { 1860 .owner = THIS_MODULE, 1861 .family = AF_TIPC, 1862 .release = release, 1863 .bind = bind, 1864 .connect = connect, 1865 .socketpair = sock_no_socketpair, 1866 .accept = accept, 1867 .getname = get_name, 1868 .poll = poll, 1869 .ioctl = sock_no_ioctl, 1870 .listen = listen, 1871 .shutdown = shutdown, 1872 .setsockopt = setsockopt, 1873 .getsockopt = getsockopt, 1874 .sendmsg = send_packet, 1875 .recvmsg = recv_msg, 1876 .mmap = sock_no_mmap, 1877 .sendpage = sock_no_sendpage 1878 }; 1879 1880 static const struct proto_ops stream_ops = { 1881 .owner = THIS_MODULE, 1882 .family = AF_TIPC, 1883 .release = release, 1884 .bind = bind, 1885 .connect = connect, 1886 .socketpair = sock_no_socketpair, 1887 .accept = accept, 1888 .getname = get_name, 1889 .poll = poll, 1890 .ioctl = sock_no_ioctl, 1891 .listen = listen, 1892 .shutdown = shutdown, 1893 .setsockopt = setsockopt, 1894 .getsockopt = getsockopt, 1895 .sendmsg = send_stream, 1896 .recvmsg = recv_stream, 1897 .mmap = sock_no_mmap, 1898 .sendpage = sock_no_sendpage 1899 }; 1900 1901 static const struct net_proto_family tipc_family_ops = { 1902 .owner = THIS_MODULE, 1903 .family = AF_TIPC, 1904 .create = tipc_sk_create 1905 }; 1906 1907 static struct proto tipc_proto = { 1908 .name = "TIPC", 1909 .owner = THIS_MODULE, 1910 .obj_size = sizeof(struct tipc_sock), 1911 .sysctl_rmem = sysctl_tipc_rmem 1912 }; 1913 1914 static struct proto tipc_proto_kern = { 1915 .name = "TIPC", 1916 .obj_size = sizeof(struct tipc_sock), 1917 .sysctl_rmem = sysctl_tipc_rmem 1918 }; 1919 1920 /** 1921 * tipc_socket_init - initialize TIPC socket interface 1922 * 1923 * Returns 0 on success, errno otherwise 1924 */ 1925 int tipc_socket_init(void) 1926 { 1927 int res; 1928 1929 res = proto_register(&tipc_proto, 1); 1930 if (res) { 1931 pr_err("Failed to register TIPC protocol type\n"); 1932 goto out; 1933 } 1934 1935 res = sock_register(&tipc_family_ops); 1936 if (res) { 1937 pr_err("Failed to register TIPC socket type\n"); 1938 proto_unregister(&tipc_proto); 1939 goto out; 1940 } 1941 1942 sockets_enabled = 1; 1943 out: 1944 return res; 1945 } 1946 1947 /** 1948 * tipc_socket_stop - stop TIPC socket interface 1949 */ 1950 void tipc_socket_stop(void) 1951 { 1952 if (!sockets_enabled) 1953 return; 1954 1955 sockets_enabled = 0; 1956 sock_unregister(tipc_family_ops.family); 1957 proto_unregister(&tipc_proto); 1958 } 1959