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 struct sock *sk; 243 244 rc = sock_create_lite(AF_TIPC, type, 0, res); 245 if (rc < 0) { 246 pr_err("Failed to create kernel socket\n"); 247 return rc; 248 } 249 tipc_sk_create(&init_net, *res, 0, 1); 250 251 sk = (*res)->sk; 252 253 return 0; 254 } 255 256 /** 257 * tipc_sock_release_local - release socket created by tipc_sock_create_local 258 * @sock: the socket to be released. 259 * 260 * Module reference count is not incremented when such sockets are created, 261 * so we must keep it from being decremented when they are released. 262 */ 263 void tipc_sock_release_local(struct socket *sock) 264 { 265 release(sock); 266 sock->ops = NULL; 267 sock_release(sock); 268 } 269 270 /** 271 * tipc_sock_accept_local - accept a connection on a socket created 272 * with tipc_sock_create_local. Use this function to avoid that 273 * module reference count is inadvertently incremented. 274 * 275 * @sock: the accepting socket 276 * @newsock: reference to the new socket to be created 277 * @flags: socket flags 278 */ 279 280 int tipc_sock_accept_local(struct socket *sock, struct socket **newsock, 281 int flags) 282 { 283 struct sock *sk = sock->sk; 284 int ret; 285 286 ret = sock_create_lite(sk->sk_family, sk->sk_type, 287 sk->sk_protocol, newsock); 288 if (ret < 0) 289 return ret; 290 291 ret = accept(sock, *newsock, flags); 292 if (ret < 0) { 293 sock_release(*newsock); 294 return ret; 295 } 296 (*newsock)->ops = sock->ops; 297 return ret; 298 } 299 300 /** 301 * release - destroy a TIPC socket 302 * @sock: socket to destroy 303 * 304 * This routine cleans up any messages that are still queued on the socket. 305 * For DGRAM and RDM socket types, all queued messages are rejected. 306 * For SEQPACKET and STREAM socket types, the first message is rejected 307 * and any others are discarded. (If the first message on a STREAM socket 308 * is partially-read, it is discarded and the next one is rejected instead.) 309 * 310 * NOTE: Rejected messages are not necessarily returned to the sender! They 311 * are returned or discarded according to the "destination droppable" setting 312 * specified for the message by the sender. 313 * 314 * Returns 0 on success, errno otherwise 315 */ 316 static int release(struct socket *sock) 317 { 318 struct sock *sk = sock->sk; 319 struct tipc_port *tport; 320 struct sk_buff *buf; 321 int res; 322 323 /* 324 * Exit if socket isn't fully initialized (occurs when a failed accept() 325 * releases a pre-allocated child socket that was never used) 326 */ 327 if (sk == NULL) 328 return 0; 329 330 tport = tipc_sk_port(sk); 331 lock_sock(sk); 332 333 /* 334 * Reject all unreceived messages, except on an active connection 335 * (which disconnects locally & sends a 'FIN+' to peer) 336 */ 337 while (sock->state != SS_DISCONNECTING) { 338 buf = __skb_dequeue(&sk->sk_receive_queue); 339 if (buf == NULL) 340 break; 341 if (TIPC_SKB_CB(buf)->handle != NULL) 342 kfree_skb(buf); 343 else { 344 if ((sock->state == SS_CONNECTING) || 345 (sock->state == SS_CONNECTED)) { 346 sock->state = SS_DISCONNECTING; 347 tipc_disconnect(tport->ref); 348 } 349 tipc_reject_msg(buf, TIPC_ERR_NO_PORT); 350 } 351 } 352 353 /* 354 * Delete TIPC port; this ensures no more messages are queued 355 * (also disconnects an active connection & sends a 'FIN-' to peer) 356 */ 357 res = tipc_deleteport(tport->ref); 358 359 /* Discard any remaining (connection-based) messages in receive queue */ 360 __skb_queue_purge(&sk->sk_receive_queue); 361 362 /* Reject any messages that accumulated in backlog queue */ 363 sock->state = SS_DISCONNECTING; 364 release_sock(sk); 365 366 sock_put(sk); 367 sock->sk = NULL; 368 369 return res; 370 } 371 372 /** 373 * bind - associate or disassocate TIPC name(s) with a socket 374 * @sock: socket structure 375 * @uaddr: socket address describing name(s) and desired operation 376 * @uaddr_len: size of socket address data structure 377 * 378 * Name and name sequence binding is indicated using a positive scope value; 379 * a negative scope value unbinds the specified name. Specifying no name 380 * (i.e. a socket address length of 0) unbinds all names from the socket. 381 * 382 * Returns 0 on success, errno otherwise 383 * 384 * NOTE: This routine doesn't need to take the socket lock since it doesn't 385 * access any non-constant socket information. 386 */ 387 static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len) 388 { 389 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; 390 u32 portref = tipc_sk_port(sock->sk)->ref; 391 392 if (unlikely(!uaddr_len)) 393 return tipc_withdraw(portref, 0, NULL); 394 395 if (uaddr_len < sizeof(struct sockaddr_tipc)) 396 return -EINVAL; 397 if (addr->family != AF_TIPC) 398 return -EAFNOSUPPORT; 399 400 if (addr->addrtype == TIPC_ADDR_NAME) 401 addr->addr.nameseq.upper = addr->addr.nameseq.lower; 402 else if (addr->addrtype != TIPC_ADDR_NAMESEQ) 403 return -EAFNOSUPPORT; 404 405 if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) && 406 (addr->addr.nameseq.type != TIPC_TOP_SRV) && 407 (addr->addr.nameseq.type != TIPC_CFG_SRV)) 408 return -EACCES; 409 410 return (addr->scope > 0) ? 411 tipc_publish(portref, addr->scope, &addr->addr.nameseq) : 412 tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq); 413 } 414 415 /** 416 * get_name - get port ID of socket or peer socket 417 * @sock: socket structure 418 * @uaddr: area for returned socket address 419 * @uaddr_len: area for returned length of socket address 420 * @peer: 0 = own ID, 1 = current peer ID, 2 = current/former peer ID 421 * 422 * Returns 0 on success, errno otherwise 423 * 424 * NOTE: This routine doesn't need to take the socket lock since it only 425 * accesses socket information that is unchanging (or which changes in 426 * a completely predictable manner). 427 */ 428 static int get_name(struct socket *sock, struct sockaddr *uaddr, 429 int *uaddr_len, int peer) 430 { 431 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; 432 struct tipc_sock *tsock = tipc_sk(sock->sk); 433 434 memset(addr, 0, sizeof(*addr)); 435 if (peer) { 436 if ((sock->state != SS_CONNECTED) && 437 ((peer != 2) || (sock->state != SS_DISCONNECTING))) 438 return -ENOTCONN; 439 addr->addr.id.ref = tsock->peer_name.ref; 440 addr->addr.id.node = tsock->peer_name.node; 441 } else { 442 addr->addr.id.ref = tsock->p->ref; 443 addr->addr.id.node = tipc_own_addr; 444 } 445 446 *uaddr_len = sizeof(*addr); 447 addr->addrtype = TIPC_ADDR_ID; 448 addr->family = AF_TIPC; 449 addr->scope = 0; 450 addr->addr.name.domain = 0; 451 452 return 0; 453 } 454 455 /** 456 * poll - read and possibly block on pollmask 457 * @file: file structure associated with the socket 458 * @sock: socket for which to calculate the poll bits 459 * @wait: ??? 460 * 461 * Returns pollmask value 462 * 463 * COMMENTARY: 464 * It appears that the usual socket locking mechanisms are not useful here 465 * since the pollmask info is potentially out-of-date the moment this routine 466 * exits. TCP and other protocols seem to rely on higher level poll routines 467 * to handle any preventable race conditions, so TIPC will do the same ... 468 * 469 * TIPC sets the returned events as follows: 470 * 471 * socket state flags set 472 * ------------ --------- 473 * unconnected no read flags 474 * POLLOUT if port is not congested 475 * 476 * connecting POLLIN/POLLRDNORM if ACK/NACK in rx queue 477 * no write flags 478 * 479 * connected POLLIN/POLLRDNORM if data in rx queue 480 * POLLOUT if port is not congested 481 * 482 * disconnecting POLLIN/POLLRDNORM/POLLHUP 483 * no write flags 484 * 485 * listening POLLIN if SYN in rx queue 486 * no write flags 487 * 488 * ready POLLIN/POLLRDNORM if data in rx queue 489 * [connectionless] POLLOUT (since port cannot be congested) 490 * 491 * IMPORTANT: The fact that a read or write operation is indicated does NOT 492 * imply that the operation will succeed, merely that it should be performed 493 * and will not block. 494 */ 495 static unsigned int poll(struct file *file, struct socket *sock, 496 poll_table *wait) 497 { 498 struct sock *sk = sock->sk; 499 u32 mask = 0; 500 501 sock_poll_wait(file, sk_sleep(sk), wait); 502 503 switch ((int)sock->state) { 504 case SS_UNCONNECTED: 505 if (!tipc_sk_port(sk)->congested) 506 mask |= POLLOUT; 507 break; 508 case SS_READY: 509 case SS_CONNECTED: 510 if (!tipc_sk_port(sk)->congested) 511 mask |= POLLOUT; 512 /* fall thru' */ 513 case SS_CONNECTING: 514 case SS_LISTENING: 515 if (!skb_queue_empty(&sk->sk_receive_queue)) 516 mask |= (POLLIN | POLLRDNORM); 517 break; 518 case SS_DISCONNECTING: 519 mask = (POLLIN | POLLRDNORM | POLLHUP); 520 break; 521 } 522 523 return mask; 524 } 525 526 /** 527 * dest_name_check - verify user is permitted to send to specified port name 528 * @dest: destination address 529 * @m: descriptor for message to be sent 530 * 531 * Prevents restricted configuration commands from being issued by 532 * unauthorized users. 533 * 534 * Returns 0 if permission is granted, otherwise errno 535 */ 536 static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m) 537 { 538 struct tipc_cfg_msg_hdr hdr; 539 540 if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES)) 541 return 0; 542 if (likely(dest->addr.name.name.type == TIPC_TOP_SRV)) 543 return 0; 544 if (likely(dest->addr.name.name.type != TIPC_CFG_SRV)) 545 return -EACCES; 546 547 if (!m->msg_iovlen || (m->msg_iov[0].iov_len < sizeof(hdr))) 548 return -EMSGSIZE; 549 if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr))) 550 return -EFAULT; 551 if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN))) 552 return -EACCES; 553 554 return 0; 555 } 556 557 /** 558 * send_msg - send message in connectionless manner 559 * @iocb: if NULL, indicates that socket lock is already held 560 * @sock: socket structure 561 * @m: message to send 562 * @total_len: length of message 563 * 564 * Message must have an destination specified explicitly. 565 * Used for SOCK_RDM and SOCK_DGRAM messages, 566 * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections. 567 * (Note: 'SYN+' is prohibited on SOCK_STREAM.) 568 * 569 * Returns the number of bytes sent on success, or errno otherwise 570 */ 571 static int send_msg(struct kiocb *iocb, struct socket *sock, 572 struct msghdr *m, size_t total_len) 573 { 574 struct sock *sk = sock->sk; 575 struct tipc_port *tport = tipc_sk_port(sk); 576 struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; 577 int needs_conn; 578 long timeout_val; 579 int res = -EINVAL; 580 581 if (unlikely(!dest)) 582 return -EDESTADDRREQ; 583 if (unlikely((m->msg_namelen < sizeof(*dest)) || 584 (dest->family != AF_TIPC))) 585 return -EINVAL; 586 if (total_len > TIPC_MAX_USER_MSG_SIZE) 587 return -EMSGSIZE; 588 589 if (iocb) 590 lock_sock(sk); 591 592 needs_conn = (sock->state != SS_READY); 593 if (unlikely(needs_conn)) { 594 if (sock->state == SS_LISTENING) { 595 res = -EPIPE; 596 goto exit; 597 } 598 if (sock->state != SS_UNCONNECTED) { 599 res = -EISCONN; 600 goto exit; 601 } 602 if (tport->published) { 603 res = -EOPNOTSUPP; 604 goto exit; 605 } 606 if (dest->addrtype == TIPC_ADDR_NAME) { 607 tport->conn_type = dest->addr.name.name.type; 608 tport->conn_instance = dest->addr.name.name.instance; 609 } 610 611 /* Abort any pending connection attempts (very unlikely) */ 612 reject_rx_queue(sk); 613 } 614 615 timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT); 616 617 do { 618 if (dest->addrtype == TIPC_ADDR_NAME) { 619 res = dest_name_check(dest, m); 620 if (res) 621 break; 622 res = tipc_send2name(tport->ref, 623 &dest->addr.name.name, 624 dest->addr.name.domain, 625 m->msg_iov, 626 total_len); 627 } else if (dest->addrtype == TIPC_ADDR_ID) { 628 res = tipc_send2port(tport->ref, 629 &dest->addr.id, 630 m->msg_iov, 631 total_len); 632 } else if (dest->addrtype == TIPC_ADDR_MCAST) { 633 if (needs_conn) { 634 res = -EOPNOTSUPP; 635 break; 636 } 637 res = dest_name_check(dest, m); 638 if (res) 639 break; 640 res = tipc_multicast(tport->ref, 641 &dest->addr.nameseq, 642 m->msg_iov, 643 total_len); 644 } 645 if (likely(res != -ELINKCONG)) { 646 if (needs_conn && (res >= 0)) 647 sock->state = SS_CONNECTING; 648 break; 649 } 650 if (timeout_val <= 0L) { 651 res = timeout_val ? timeout_val : -EWOULDBLOCK; 652 break; 653 } 654 release_sock(sk); 655 timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk), 656 !tport->congested, timeout_val); 657 lock_sock(sk); 658 } while (1); 659 660 exit: 661 if (iocb) 662 release_sock(sk); 663 return res; 664 } 665 666 /** 667 * send_packet - send a connection-oriented message 668 * @iocb: if NULL, indicates that socket lock is already held 669 * @sock: socket structure 670 * @m: message to send 671 * @total_len: length of message 672 * 673 * Used for SOCK_SEQPACKET messages and SOCK_STREAM data. 674 * 675 * Returns the number of bytes sent on success, or errno otherwise 676 */ 677 static int send_packet(struct kiocb *iocb, struct socket *sock, 678 struct msghdr *m, size_t total_len) 679 { 680 struct sock *sk = sock->sk; 681 struct tipc_port *tport = tipc_sk_port(sk); 682 struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name; 683 long timeout_val; 684 int res; 685 686 /* Handle implied connection establishment */ 687 if (unlikely(dest)) 688 return send_msg(iocb, sock, m, total_len); 689 690 if (total_len > TIPC_MAX_USER_MSG_SIZE) 691 return -EMSGSIZE; 692 693 if (iocb) 694 lock_sock(sk); 695 696 timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT); 697 698 do { 699 if (unlikely(sock->state != SS_CONNECTED)) { 700 if (sock->state == SS_DISCONNECTING) 701 res = -EPIPE; 702 else 703 res = -ENOTCONN; 704 break; 705 } 706 707 res = tipc_send(tport->ref, m->msg_iov, total_len); 708 if (likely(res != -ELINKCONG)) 709 break; 710 if (timeout_val <= 0L) { 711 res = timeout_val ? timeout_val : -EWOULDBLOCK; 712 break; 713 } 714 release_sock(sk); 715 timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk), 716 (!tport->congested || !tport->connected), timeout_val); 717 lock_sock(sk); 718 } while (1); 719 720 if (iocb) 721 release_sock(sk); 722 return res; 723 } 724 725 /** 726 * send_stream - send stream-oriented data 727 * @iocb: (unused) 728 * @sock: socket structure 729 * @m: data to send 730 * @total_len: total length of data to be sent 731 * 732 * Used for SOCK_STREAM data. 733 * 734 * Returns the number of bytes sent on success (or partial success), 735 * or errno if no data sent 736 */ 737 static int send_stream(struct kiocb *iocb, struct socket *sock, 738 struct msghdr *m, size_t total_len) 739 { 740 struct sock *sk = sock->sk; 741 struct tipc_port *tport = tipc_sk_port(sk); 742 struct msghdr my_msg; 743 struct iovec my_iov; 744 struct iovec *curr_iov; 745 int curr_iovlen; 746 char __user *curr_start; 747 u32 hdr_size; 748 int curr_left; 749 int bytes_to_send; 750 int bytes_sent; 751 int res; 752 753 lock_sock(sk); 754 755 /* Handle special cases where there is no connection */ 756 if (unlikely(sock->state != SS_CONNECTED)) { 757 if (sock->state == SS_UNCONNECTED) { 758 res = send_packet(NULL, sock, m, total_len); 759 goto exit; 760 } else if (sock->state == SS_DISCONNECTING) { 761 res = -EPIPE; 762 goto exit; 763 } else { 764 res = -ENOTCONN; 765 goto exit; 766 } 767 } 768 769 if (unlikely(m->msg_name)) { 770 res = -EISCONN; 771 goto exit; 772 } 773 774 if (total_len > (unsigned int)INT_MAX) { 775 res = -EMSGSIZE; 776 goto exit; 777 } 778 779 /* 780 * Send each iovec entry using one or more messages 781 * 782 * Note: This algorithm is good for the most likely case 783 * (i.e. one large iovec entry), but could be improved to pass sets 784 * of small iovec entries into send_packet(). 785 */ 786 curr_iov = m->msg_iov; 787 curr_iovlen = m->msg_iovlen; 788 my_msg.msg_iov = &my_iov; 789 my_msg.msg_iovlen = 1; 790 my_msg.msg_flags = m->msg_flags; 791 my_msg.msg_name = NULL; 792 bytes_sent = 0; 793 794 hdr_size = msg_hdr_sz(&tport->phdr); 795 796 while (curr_iovlen--) { 797 curr_start = curr_iov->iov_base; 798 curr_left = curr_iov->iov_len; 799 800 while (curr_left) { 801 bytes_to_send = tport->max_pkt - hdr_size; 802 if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE) 803 bytes_to_send = TIPC_MAX_USER_MSG_SIZE; 804 if (curr_left < bytes_to_send) 805 bytes_to_send = curr_left; 806 my_iov.iov_base = curr_start; 807 my_iov.iov_len = bytes_to_send; 808 res = send_packet(NULL, sock, &my_msg, bytes_to_send); 809 if (res < 0) { 810 if (bytes_sent) 811 res = bytes_sent; 812 goto exit; 813 } 814 curr_left -= bytes_to_send; 815 curr_start += bytes_to_send; 816 bytes_sent += bytes_to_send; 817 } 818 819 curr_iov++; 820 } 821 res = bytes_sent; 822 exit: 823 release_sock(sk); 824 return res; 825 } 826 827 /** 828 * auto_connect - complete connection setup to a remote port 829 * @sock: socket structure 830 * @msg: peer's response message 831 * 832 * Returns 0 on success, errno otherwise 833 */ 834 static int auto_connect(struct socket *sock, struct tipc_msg *msg) 835 { 836 struct tipc_sock *tsock = tipc_sk(sock->sk); 837 struct tipc_port *p_ptr; 838 839 tsock->peer_name.ref = msg_origport(msg); 840 tsock->peer_name.node = msg_orignode(msg); 841 p_ptr = tipc_port_deref(tsock->p->ref); 842 if (!p_ptr) 843 return -EINVAL; 844 845 __tipc_connect(tsock->p->ref, p_ptr, &tsock->peer_name); 846 847 if (msg_importance(msg) > TIPC_CRITICAL_IMPORTANCE) 848 return -EINVAL; 849 msg_set_importance(&p_ptr->phdr, (u32)msg_importance(msg)); 850 sock->state = SS_CONNECTED; 851 return 0; 852 } 853 854 /** 855 * set_orig_addr - capture sender's address for received message 856 * @m: descriptor for message info 857 * @msg: received message header 858 * 859 * Note: Address is not captured if not requested by receiver. 860 */ 861 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg) 862 { 863 struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name; 864 865 if (addr) { 866 addr->family = AF_TIPC; 867 addr->addrtype = TIPC_ADDR_ID; 868 memset(&addr->addr, 0, sizeof(addr->addr)); 869 addr->addr.id.ref = msg_origport(msg); 870 addr->addr.id.node = msg_orignode(msg); 871 addr->addr.name.domain = 0; /* could leave uninitialized */ 872 addr->scope = 0; /* could leave uninitialized */ 873 m->msg_namelen = sizeof(struct sockaddr_tipc); 874 } 875 } 876 877 /** 878 * anc_data_recv - optionally capture ancillary data for received message 879 * @m: descriptor for message info 880 * @msg: received message header 881 * @tport: TIPC port associated with message 882 * 883 * Note: Ancillary data is not captured if not requested by receiver. 884 * 885 * Returns 0 if successful, otherwise errno 886 */ 887 static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg, 888 struct tipc_port *tport) 889 { 890 u32 anc_data[3]; 891 u32 err; 892 u32 dest_type; 893 int has_name; 894 int res; 895 896 if (likely(m->msg_controllen == 0)) 897 return 0; 898 899 /* Optionally capture errored message object(s) */ 900 err = msg ? msg_errcode(msg) : 0; 901 if (unlikely(err)) { 902 anc_data[0] = err; 903 anc_data[1] = msg_data_sz(msg); 904 res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data); 905 if (res) 906 return res; 907 if (anc_data[1]) { 908 res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1], 909 msg_data(msg)); 910 if (res) 911 return res; 912 } 913 } 914 915 /* Optionally capture message destination object */ 916 dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG; 917 switch (dest_type) { 918 case TIPC_NAMED_MSG: 919 has_name = 1; 920 anc_data[0] = msg_nametype(msg); 921 anc_data[1] = msg_namelower(msg); 922 anc_data[2] = msg_namelower(msg); 923 break; 924 case TIPC_MCAST_MSG: 925 has_name = 1; 926 anc_data[0] = msg_nametype(msg); 927 anc_data[1] = msg_namelower(msg); 928 anc_data[2] = msg_nameupper(msg); 929 break; 930 case TIPC_CONN_MSG: 931 has_name = (tport->conn_type != 0); 932 anc_data[0] = tport->conn_type; 933 anc_data[1] = tport->conn_instance; 934 anc_data[2] = tport->conn_instance; 935 break; 936 default: 937 has_name = 0; 938 } 939 if (has_name) { 940 res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data); 941 if (res) 942 return res; 943 } 944 945 return 0; 946 } 947 948 /** 949 * recv_msg - receive packet-oriented message 950 * @iocb: (unused) 951 * @m: descriptor for message info 952 * @buf_len: total size of user buffer area 953 * @flags: receive flags 954 * 955 * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages. 956 * If the complete message doesn't fit in user area, truncate it. 957 * 958 * Returns size of returned message data, errno otherwise 959 */ 960 static int recv_msg(struct kiocb *iocb, struct socket *sock, 961 struct msghdr *m, size_t buf_len, int flags) 962 { 963 struct sock *sk = sock->sk; 964 struct tipc_port *tport = tipc_sk_port(sk); 965 struct sk_buff *buf; 966 struct tipc_msg *msg; 967 long timeout; 968 unsigned int sz; 969 u32 err; 970 int res; 971 972 /* Catch invalid receive requests */ 973 if (unlikely(!buf_len)) 974 return -EINVAL; 975 976 lock_sock(sk); 977 978 if (unlikely(sock->state == SS_UNCONNECTED)) { 979 res = -ENOTCONN; 980 goto exit; 981 } 982 983 /* will be updated in set_orig_addr() if needed */ 984 m->msg_namelen = 0; 985 986 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 987 restart: 988 989 /* Look for a message in receive queue; wait if necessary */ 990 while (skb_queue_empty(&sk->sk_receive_queue)) { 991 if (sock->state == SS_DISCONNECTING) { 992 res = -ENOTCONN; 993 goto exit; 994 } 995 if (timeout <= 0L) { 996 res = timeout ? timeout : -EWOULDBLOCK; 997 goto exit; 998 } 999 release_sock(sk); 1000 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 1001 tipc_rx_ready(sock), 1002 timeout); 1003 lock_sock(sk); 1004 } 1005 1006 /* Look at first message in receive queue */ 1007 buf = skb_peek(&sk->sk_receive_queue); 1008 msg = buf_msg(buf); 1009 sz = msg_data_sz(msg); 1010 err = msg_errcode(msg); 1011 1012 /* Discard an empty non-errored message & try again */ 1013 if ((!sz) && (!err)) { 1014 advance_rx_queue(sk); 1015 goto restart; 1016 } 1017 1018 /* Capture sender's address (optional) */ 1019 set_orig_addr(m, msg); 1020 1021 /* Capture ancillary data (optional) */ 1022 res = anc_data_recv(m, msg, tport); 1023 if (res) 1024 goto exit; 1025 1026 /* Capture message data (if valid) & compute return value (always) */ 1027 if (!err) { 1028 if (unlikely(buf_len < sz)) { 1029 sz = buf_len; 1030 m->msg_flags |= MSG_TRUNC; 1031 } 1032 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg), 1033 m->msg_iov, sz); 1034 if (res) 1035 goto exit; 1036 res = sz; 1037 } else { 1038 if ((sock->state == SS_READY) || 1039 ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)) 1040 res = 0; 1041 else 1042 res = -ECONNRESET; 1043 } 1044 1045 /* Consume received message (optional) */ 1046 if (likely(!(flags & MSG_PEEK))) { 1047 if ((sock->state != SS_READY) && 1048 (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1049 tipc_acknowledge(tport->ref, tport->conn_unacked); 1050 advance_rx_queue(sk); 1051 } 1052 exit: 1053 release_sock(sk); 1054 return res; 1055 } 1056 1057 /** 1058 * recv_stream - receive stream-oriented data 1059 * @iocb: (unused) 1060 * @m: descriptor for message info 1061 * @buf_len: total size of user buffer area 1062 * @flags: receive flags 1063 * 1064 * Used for SOCK_STREAM messages only. If not enough data is available 1065 * will optionally wait for more; never truncates data. 1066 * 1067 * Returns size of returned message data, errno otherwise 1068 */ 1069 static int recv_stream(struct kiocb *iocb, struct socket *sock, 1070 struct msghdr *m, size_t buf_len, int flags) 1071 { 1072 struct sock *sk = sock->sk; 1073 struct tipc_port *tport = tipc_sk_port(sk); 1074 struct sk_buff *buf; 1075 struct tipc_msg *msg; 1076 long timeout; 1077 unsigned int sz; 1078 int sz_to_copy, target, needed; 1079 int sz_copied = 0; 1080 u32 err; 1081 int res = 0; 1082 1083 /* Catch invalid receive attempts */ 1084 if (unlikely(!buf_len)) 1085 return -EINVAL; 1086 1087 lock_sock(sk); 1088 1089 if (unlikely((sock->state == SS_UNCONNECTED))) { 1090 res = -ENOTCONN; 1091 goto exit; 1092 } 1093 1094 /* will be updated in set_orig_addr() if needed */ 1095 m->msg_namelen = 0; 1096 1097 target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len); 1098 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1099 1100 restart: 1101 /* Look for a message in receive queue; wait if necessary */ 1102 while (skb_queue_empty(&sk->sk_receive_queue)) { 1103 if (sock->state == SS_DISCONNECTING) { 1104 res = -ENOTCONN; 1105 goto exit; 1106 } 1107 if (timeout <= 0L) { 1108 res = timeout ? timeout : -EWOULDBLOCK; 1109 goto exit; 1110 } 1111 release_sock(sk); 1112 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 1113 tipc_rx_ready(sock), 1114 timeout); 1115 lock_sock(sk); 1116 } 1117 1118 /* Look at first message in receive queue */ 1119 buf = skb_peek(&sk->sk_receive_queue); 1120 msg = buf_msg(buf); 1121 sz = msg_data_sz(msg); 1122 err = msg_errcode(msg); 1123 1124 /* Discard an empty non-errored message & try again */ 1125 if ((!sz) && (!err)) { 1126 advance_rx_queue(sk); 1127 goto restart; 1128 } 1129 1130 /* Optionally capture sender's address & ancillary data of first msg */ 1131 if (sz_copied == 0) { 1132 set_orig_addr(m, msg); 1133 res = anc_data_recv(m, msg, tport); 1134 if (res) 1135 goto exit; 1136 } 1137 1138 /* Capture message data (if valid) & compute return value (always) */ 1139 if (!err) { 1140 u32 offset = (u32)(unsigned long)(TIPC_SKB_CB(buf)->handle); 1141 1142 sz -= offset; 1143 needed = (buf_len - sz_copied); 1144 sz_to_copy = (sz <= needed) ? sz : needed; 1145 1146 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg) + offset, 1147 m->msg_iov, sz_to_copy); 1148 if (res) 1149 goto exit; 1150 1151 sz_copied += sz_to_copy; 1152 1153 if (sz_to_copy < sz) { 1154 if (!(flags & MSG_PEEK)) 1155 TIPC_SKB_CB(buf)->handle = 1156 (void *)(unsigned long)(offset + sz_to_copy); 1157 goto exit; 1158 } 1159 } else { 1160 if (sz_copied != 0) 1161 goto exit; /* can't add error msg to valid data */ 1162 1163 if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control) 1164 res = 0; 1165 else 1166 res = -ECONNRESET; 1167 } 1168 1169 /* Consume received message (optional) */ 1170 if (likely(!(flags & MSG_PEEK))) { 1171 if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1172 tipc_acknowledge(tport->ref, tport->conn_unacked); 1173 advance_rx_queue(sk); 1174 } 1175 1176 /* Loop around if more data is required */ 1177 if ((sz_copied < buf_len) && /* didn't get all requested data */ 1178 (!skb_queue_empty(&sk->sk_receive_queue) || 1179 (sz_copied < target)) && /* and more is ready or required */ 1180 (!(flags & MSG_PEEK)) && /* and aren't just peeking at data */ 1181 (!err)) /* and haven't reached a FIN */ 1182 goto restart; 1183 1184 exit: 1185 release_sock(sk); 1186 return sz_copied ? sz_copied : res; 1187 } 1188 1189 /** 1190 * tipc_write_space - wake up thread if port congestion is released 1191 * @sk: socket 1192 */ 1193 static void tipc_write_space(struct sock *sk) 1194 { 1195 struct socket_wq *wq; 1196 1197 rcu_read_lock(); 1198 wq = rcu_dereference(sk->sk_wq); 1199 if (wq_has_sleeper(wq)) 1200 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | 1201 POLLWRNORM | POLLWRBAND); 1202 rcu_read_unlock(); 1203 } 1204 1205 /** 1206 * tipc_data_ready - wake up threads to indicate messages have been received 1207 * @sk: socket 1208 * @len: the length of messages 1209 */ 1210 static void tipc_data_ready(struct sock *sk, int len) 1211 { 1212 struct socket_wq *wq; 1213 1214 rcu_read_lock(); 1215 wq = rcu_dereference(sk->sk_wq); 1216 if (wq_has_sleeper(wq)) 1217 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | 1218 POLLRDNORM | POLLRDBAND); 1219 rcu_read_unlock(); 1220 } 1221 1222 /** 1223 * filter_connect - Handle all incoming messages for a connection-based socket 1224 * @tsock: TIPC socket 1225 * @msg: message 1226 * 1227 * Returns TIPC error status code and socket error status code 1228 * once it encounters some errors 1229 */ 1230 static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf) 1231 { 1232 struct socket *sock = tsock->sk.sk_socket; 1233 struct tipc_msg *msg = buf_msg(*buf); 1234 struct sock *sk = &tsock->sk; 1235 u32 retval = TIPC_ERR_NO_PORT; 1236 int res; 1237 1238 if (msg_mcast(msg)) 1239 return retval; 1240 1241 switch ((int)sock->state) { 1242 case SS_CONNECTED: 1243 /* Accept only connection-based messages sent by peer */ 1244 if (msg_connected(msg) && tipc_port_peer_msg(tsock->p, msg)) { 1245 if (unlikely(msg_errcode(msg))) { 1246 sock->state = SS_DISCONNECTING; 1247 __tipc_disconnect(tsock->p); 1248 } 1249 retval = TIPC_OK; 1250 } 1251 break; 1252 case SS_CONNECTING: 1253 /* Accept only ACK or NACK message */ 1254 if (unlikely(msg_errcode(msg))) { 1255 sock->state = SS_DISCONNECTING; 1256 sk->sk_err = ECONNREFUSED; 1257 retval = TIPC_OK; 1258 break; 1259 } 1260 1261 if (unlikely(!msg_connected(msg))) 1262 break; 1263 1264 res = auto_connect(sock, msg); 1265 if (res) { 1266 sock->state = SS_DISCONNECTING; 1267 sk->sk_err = -res; 1268 retval = TIPC_OK; 1269 break; 1270 } 1271 1272 /* If an incoming message is an 'ACK-', it should be 1273 * discarded here because it doesn't contain useful 1274 * data. In addition, we should try to wake up 1275 * connect() routine if sleeping. 1276 */ 1277 if (msg_data_sz(msg) == 0) { 1278 kfree_skb(*buf); 1279 *buf = NULL; 1280 if (waitqueue_active(sk_sleep(sk))) 1281 wake_up_interruptible(sk_sleep(sk)); 1282 } 1283 retval = TIPC_OK; 1284 break; 1285 case SS_LISTENING: 1286 case SS_UNCONNECTED: 1287 /* Accept only SYN message */ 1288 if (!msg_connected(msg) && !(msg_errcode(msg))) 1289 retval = TIPC_OK; 1290 break; 1291 case SS_DISCONNECTING: 1292 break; 1293 default: 1294 pr_err("Unknown socket state %u\n", sock->state); 1295 } 1296 return retval; 1297 } 1298 1299 /** 1300 * rcvbuf_limit - get proper overload limit of socket receive queue 1301 * @sk: socket 1302 * @buf: message 1303 * 1304 * For all connection oriented messages, irrespective of importance, 1305 * the default overload value (i.e. 67MB) is set as limit. 1306 * 1307 * For all connectionless messages, by default new queue limits are 1308 * as belows: 1309 * 1310 * TIPC_LOW_IMPORTANCE (4 MB) 1311 * TIPC_MEDIUM_IMPORTANCE (8 MB) 1312 * TIPC_HIGH_IMPORTANCE (16 MB) 1313 * TIPC_CRITICAL_IMPORTANCE (32 MB) 1314 * 1315 * Returns overload limit according to corresponding message importance 1316 */ 1317 static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf) 1318 { 1319 struct tipc_msg *msg = buf_msg(buf); 1320 unsigned int limit; 1321 1322 if (msg_connected(msg)) 1323 limit = sysctl_tipc_rmem[2]; 1324 else 1325 limit = sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE << 1326 msg_importance(msg); 1327 return limit; 1328 } 1329 1330 /** 1331 * filter_rcv - validate incoming message 1332 * @sk: socket 1333 * @buf: message 1334 * 1335 * Enqueues message on receive queue if acceptable; optionally handles 1336 * disconnect indication for a connected socket. 1337 * 1338 * Called with socket lock already taken; port lock may also be taken. 1339 * 1340 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1341 */ 1342 static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) 1343 { 1344 struct socket *sock = sk->sk_socket; 1345 struct tipc_msg *msg = buf_msg(buf); 1346 unsigned int limit = rcvbuf_limit(sk, buf); 1347 u32 res = TIPC_OK; 1348 1349 /* Reject message if it is wrong sort of message for socket */ 1350 if (msg_type(msg) > TIPC_DIRECT_MSG) 1351 return TIPC_ERR_NO_PORT; 1352 1353 if (sock->state == SS_READY) { 1354 if (msg_connected(msg)) 1355 return TIPC_ERR_NO_PORT; 1356 } else { 1357 res = filter_connect(tipc_sk(sk), &buf); 1358 if (res != TIPC_OK || buf == NULL) 1359 return res; 1360 } 1361 1362 /* Reject message if there isn't room to queue it */ 1363 if (sk_rmem_alloc_get(sk) + buf->truesize >= limit) 1364 return TIPC_ERR_OVERLOAD; 1365 1366 /* Enqueue message */ 1367 TIPC_SKB_CB(buf)->handle = NULL; 1368 __skb_queue_tail(&sk->sk_receive_queue, buf); 1369 skb_set_owner_r(buf, sk); 1370 1371 sk->sk_data_ready(sk, 0); 1372 return TIPC_OK; 1373 } 1374 1375 /** 1376 * backlog_rcv - handle incoming message from backlog queue 1377 * @sk: socket 1378 * @buf: message 1379 * 1380 * Caller must hold socket lock, but not port lock. 1381 * 1382 * Returns 0 1383 */ 1384 static int backlog_rcv(struct sock *sk, struct sk_buff *buf) 1385 { 1386 u32 res; 1387 1388 res = filter_rcv(sk, buf); 1389 if (res) 1390 tipc_reject_msg(buf, res); 1391 return 0; 1392 } 1393 1394 /** 1395 * dispatch - handle incoming message 1396 * @tport: TIPC port that received message 1397 * @buf: message 1398 * 1399 * Called with port lock already taken. 1400 * 1401 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1402 */ 1403 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf) 1404 { 1405 struct sock *sk = tport->sk; 1406 u32 res; 1407 1408 /* 1409 * Process message if socket is unlocked; otherwise add to backlog queue 1410 * 1411 * This code is based on sk_receive_skb(), but must be distinct from it 1412 * since a TIPC-specific filter/reject mechanism is utilized 1413 */ 1414 bh_lock_sock(sk); 1415 if (!sock_owned_by_user(sk)) { 1416 res = filter_rcv(sk, buf); 1417 } else { 1418 if (sk_add_backlog(sk, buf, rcvbuf_limit(sk, buf))) 1419 res = TIPC_ERR_OVERLOAD; 1420 else 1421 res = TIPC_OK; 1422 } 1423 bh_unlock_sock(sk); 1424 1425 return res; 1426 } 1427 1428 /** 1429 * wakeupdispatch - wake up port after congestion 1430 * @tport: port to wakeup 1431 * 1432 * Called with port lock already taken. 1433 */ 1434 static void wakeupdispatch(struct tipc_port *tport) 1435 { 1436 struct sock *sk = tport->sk; 1437 1438 sk->sk_write_space(sk); 1439 } 1440 1441 /** 1442 * connect - establish a connection to another TIPC port 1443 * @sock: socket structure 1444 * @dest: socket address for destination port 1445 * @destlen: size of socket address data structure 1446 * @flags: file-related flags associated with socket 1447 * 1448 * Returns 0 on success, errno otherwise 1449 */ 1450 static int connect(struct socket *sock, struct sockaddr *dest, int destlen, 1451 int flags) 1452 { 1453 struct sock *sk = sock->sk; 1454 struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest; 1455 struct msghdr m = {NULL,}; 1456 unsigned int timeout; 1457 int res; 1458 1459 lock_sock(sk); 1460 1461 /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */ 1462 if (sock->state == SS_READY) { 1463 res = -EOPNOTSUPP; 1464 goto exit; 1465 } 1466 1467 /* 1468 * Reject connection attempt using multicast address 1469 * 1470 * Note: send_msg() validates the rest of the address fields, 1471 * so there's no need to do it here 1472 */ 1473 if (dst->addrtype == TIPC_ADDR_MCAST) { 1474 res = -EINVAL; 1475 goto exit; 1476 } 1477 1478 timeout = (flags & O_NONBLOCK) ? 0 : tipc_sk(sk)->conn_timeout; 1479 1480 switch (sock->state) { 1481 case SS_UNCONNECTED: 1482 /* Send a 'SYN-' to destination */ 1483 m.msg_name = dest; 1484 m.msg_namelen = destlen; 1485 1486 /* If connect is in non-blocking case, set MSG_DONTWAIT to 1487 * indicate send_msg() is never blocked. 1488 */ 1489 if (!timeout) 1490 m.msg_flags = MSG_DONTWAIT; 1491 1492 res = send_msg(NULL, sock, &m, 0); 1493 if ((res < 0) && (res != -EWOULDBLOCK)) 1494 goto exit; 1495 1496 /* Just entered SS_CONNECTING state; the only 1497 * difference is that return value in non-blocking 1498 * case is EINPROGRESS, rather than EALREADY. 1499 */ 1500 res = -EINPROGRESS; 1501 break; 1502 case SS_CONNECTING: 1503 res = -EALREADY; 1504 break; 1505 case SS_CONNECTED: 1506 res = -EISCONN; 1507 break; 1508 default: 1509 res = -EINVAL; 1510 goto exit; 1511 } 1512 1513 if (sock->state == SS_CONNECTING) { 1514 if (!timeout) 1515 goto exit; 1516 1517 /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */ 1518 release_sock(sk); 1519 res = wait_event_interruptible_timeout(*sk_sleep(sk), 1520 sock->state != SS_CONNECTING, 1521 timeout ? (long)msecs_to_jiffies(timeout) 1522 : MAX_SCHEDULE_TIMEOUT); 1523 lock_sock(sk); 1524 if (res <= 0) { 1525 if (res == 0) 1526 res = -ETIMEDOUT; 1527 else 1528 ; /* leave "res" unchanged */ 1529 goto exit; 1530 } 1531 } 1532 1533 if (unlikely(sock->state == SS_DISCONNECTING)) 1534 res = sock_error(sk); 1535 else 1536 res = 0; 1537 1538 exit: 1539 release_sock(sk); 1540 return res; 1541 } 1542 1543 /** 1544 * listen - allow socket to listen for incoming connections 1545 * @sock: socket structure 1546 * @len: (unused) 1547 * 1548 * Returns 0 on success, errno otherwise 1549 */ 1550 static int listen(struct socket *sock, int len) 1551 { 1552 struct sock *sk = sock->sk; 1553 int res; 1554 1555 lock_sock(sk); 1556 1557 if (sock->state != SS_UNCONNECTED) 1558 res = -EINVAL; 1559 else { 1560 sock->state = SS_LISTENING; 1561 res = 0; 1562 } 1563 1564 release_sock(sk); 1565 return res; 1566 } 1567 1568 /** 1569 * accept - wait for connection request 1570 * @sock: listening socket 1571 * @newsock: new socket that is to be connected 1572 * @flags: file-related flags associated with socket 1573 * 1574 * Returns 0 on success, errno otherwise 1575 */ 1576 static int accept(struct socket *sock, struct socket *new_sock, int flags) 1577 { 1578 struct sock *new_sk, *sk = sock->sk; 1579 struct sk_buff *buf; 1580 struct tipc_sock *new_tsock; 1581 struct tipc_port *new_tport; 1582 struct tipc_msg *msg; 1583 u32 new_ref; 1584 1585 int res; 1586 1587 lock_sock(sk); 1588 1589 if (sock->state != SS_LISTENING) { 1590 res = -EINVAL; 1591 goto exit; 1592 } 1593 1594 while (skb_queue_empty(&sk->sk_receive_queue)) { 1595 if (flags & O_NONBLOCK) { 1596 res = -EWOULDBLOCK; 1597 goto exit; 1598 } 1599 release_sock(sk); 1600 res = wait_event_interruptible(*sk_sleep(sk), 1601 (!skb_queue_empty(&sk->sk_receive_queue))); 1602 lock_sock(sk); 1603 if (res) 1604 goto exit; 1605 } 1606 1607 buf = skb_peek(&sk->sk_receive_queue); 1608 1609 res = tipc_sk_create(sock_net(sock->sk), new_sock, 0, 1); 1610 if (res) 1611 goto exit; 1612 1613 new_sk = new_sock->sk; 1614 new_tsock = tipc_sk(new_sk); 1615 new_tport = new_tsock->p; 1616 new_ref = new_tport->ref; 1617 msg = buf_msg(buf); 1618 1619 /* we lock on new_sk; but lockdep sees the lock on sk */ 1620 lock_sock_nested(new_sk, SINGLE_DEPTH_NESTING); 1621 1622 /* 1623 * Reject any stray messages received by new socket 1624 * before the socket lock was taken (very, very unlikely) 1625 */ 1626 reject_rx_queue(new_sk); 1627 1628 /* Connect new socket to it's peer */ 1629 new_tsock->peer_name.ref = msg_origport(msg); 1630 new_tsock->peer_name.node = msg_orignode(msg); 1631 tipc_connect(new_ref, &new_tsock->peer_name); 1632 new_sock->state = SS_CONNECTED; 1633 1634 tipc_set_portimportance(new_ref, msg_importance(msg)); 1635 if (msg_named(msg)) { 1636 new_tport->conn_type = msg_nametype(msg); 1637 new_tport->conn_instance = msg_nameinst(msg); 1638 } 1639 1640 /* 1641 * Respond to 'SYN-' by discarding it & returning 'ACK'-. 1642 * Respond to 'SYN+' by queuing it on new socket. 1643 */ 1644 if (!msg_data_sz(msg)) { 1645 struct msghdr m = {NULL,}; 1646 1647 advance_rx_queue(sk); 1648 send_packet(NULL, new_sock, &m, 0); 1649 } else { 1650 __skb_dequeue(&sk->sk_receive_queue); 1651 __skb_queue_head(&new_sk->sk_receive_queue, buf); 1652 skb_set_owner_r(buf, new_sk); 1653 } 1654 release_sock(new_sk); 1655 1656 exit: 1657 release_sock(sk); 1658 return res; 1659 } 1660 1661 /** 1662 * shutdown - shutdown socket connection 1663 * @sock: socket structure 1664 * @how: direction to close (must be SHUT_RDWR) 1665 * 1666 * Terminates connection (if necessary), then purges socket's receive queue. 1667 * 1668 * Returns 0 on success, errno otherwise 1669 */ 1670 static int shutdown(struct socket *sock, int how) 1671 { 1672 struct sock *sk = sock->sk; 1673 struct tipc_port *tport = tipc_sk_port(sk); 1674 struct sk_buff *buf; 1675 int res; 1676 1677 if (how != SHUT_RDWR) 1678 return -EINVAL; 1679 1680 lock_sock(sk); 1681 1682 switch (sock->state) { 1683 case SS_CONNECTING: 1684 case SS_CONNECTED: 1685 1686 restart: 1687 /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */ 1688 buf = __skb_dequeue(&sk->sk_receive_queue); 1689 if (buf) { 1690 if (TIPC_SKB_CB(buf)->handle != NULL) { 1691 kfree_skb(buf); 1692 goto restart; 1693 } 1694 tipc_disconnect(tport->ref); 1695 tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); 1696 } else { 1697 tipc_shutdown(tport->ref); 1698 } 1699 1700 sock->state = SS_DISCONNECTING; 1701 1702 /* fall through */ 1703 1704 case SS_DISCONNECTING: 1705 1706 /* Discard any unreceived messages */ 1707 __skb_queue_purge(&sk->sk_receive_queue); 1708 1709 /* Wake up anyone sleeping in poll */ 1710 sk->sk_state_change(sk); 1711 res = 0; 1712 break; 1713 1714 default: 1715 res = -ENOTCONN; 1716 } 1717 1718 release_sock(sk); 1719 return res; 1720 } 1721 1722 /** 1723 * setsockopt - set socket option 1724 * @sock: socket structure 1725 * @lvl: option level 1726 * @opt: option identifier 1727 * @ov: pointer to new option value 1728 * @ol: length of option value 1729 * 1730 * For stream sockets only, accepts and ignores all IPPROTO_TCP options 1731 * (to ease compatibility). 1732 * 1733 * Returns 0 on success, errno otherwise 1734 */ 1735 static int setsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1736 unsigned int ol) 1737 { 1738 struct sock *sk = sock->sk; 1739 struct tipc_port *tport = tipc_sk_port(sk); 1740 u32 value; 1741 int res; 1742 1743 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1744 return 0; 1745 if (lvl != SOL_TIPC) 1746 return -ENOPROTOOPT; 1747 if (ol < sizeof(value)) 1748 return -EINVAL; 1749 res = get_user(value, (u32 __user *)ov); 1750 if (res) 1751 return res; 1752 1753 lock_sock(sk); 1754 1755 switch (opt) { 1756 case TIPC_IMPORTANCE: 1757 res = tipc_set_portimportance(tport->ref, value); 1758 break; 1759 case TIPC_SRC_DROPPABLE: 1760 if (sock->type != SOCK_STREAM) 1761 res = tipc_set_portunreliable(tport->ref, value); 1762 else 1763 res = -ENOPROTOOPT; 1764 break; 1765 case TIPC_DEST_DROPPABLE: 1766 res = tipc_set_portunreturnable(tport->ref, value); 1767 break; 1768 case TIPC_CONN_TIMEOUT: 1769 tipc_sk(sk)->conn_timeout = value; 1770 /* no need to set "res", since already 0 at this point */ 1771 break; 1772 default: 1773 res = -EINVAL; 1774 } 1775 1776 release_sock(sk); 1777 1778 return res; 1779 } 1780 1781 /** 1782 * getsockopt - get socket option 1783 * @sock: socket structure 1784 * @lvl: option level 1785 * @opt: option identifier 1786 * @ov: receptacle for option value 1787 * @ol: receptacle for length of option value 1788 * 1789 * For stream sockets only, returns 0 length result for all IPPROTO_TCP options 1790 * (to ease compatibility). 1791 * 1792 * Returns 0 on success, errno otherwise 1793 */ 1794 static int getsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1795 int __user *ol) 1796 { 1797 struct sock *sk = sock->sk; 1798 struct tipc_port *tport = tipc_sk_port(sk); 1799 int len; 1800 u32 value; 1801 int res; 1802 1803 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1804 return put_user(0, ol); 1805 if (lvl != SOL_TIPC) 1806 return -ENOPROTOOPT; 1807 res = get_user(len, ol); 1808 if (res) 1809 return res; 1810 1811 lock_sock(sk); 1812 1813 switch (opt) { 1814 case TIPC_IMPORTANCE: 1815 res = tipc_portimportance(tport->ref, &value); 1816 break; 1817 case TIPC_SRC_DROPPABLE: 1818 res = tipc_portunreliable(tport->ref, &value); 1819 break; 1820 case TIPC_DEST_DROPPABLE: 1821 res = tipc_portunreturnable(tport->ref, &value); 1822 break; 1823 case TIPC_CONN_TIMEOUT: 1824 value = tipc_sk(sk)->conn_timeout; 1825 /* no need to set "res", since already 0 at this point */ 1826 break; 1827 case TIPC_NODE_RECVQ_DEPTH: 1828 value = 0; /* was tipc_queue_size, now obsolete */ 1829 break; 1830 case TIPC_SOCK_RECVQ_DEPTH: 1831 value = skb_queue_len(&sk->sk_receive_queue); 1832 break; 1833 default: 1834 res = -EINVAL; 1835 } 1836 1837 release_sock(sk); 1838 1839 if (res) 1840 return res; /* "get" failed */ 1841 1842 if (len < sizeof(value)) 1843 return -EINVAL; 1844 1845 if (copy_to_user(ov, &value, sizeof(value))) 1846 return -EFAULT; 1847 1848 return put_user(sizeof(value), ol); 1849 } 1850 1851 /* Protocol switches for the various types of TIPC sockets */ 1852 1853 static const struct proto_ops msg_ops = { 1854 .owner = THIS_MODULE, 1855 .family = AF_TIPC, 1856 .release = release, 1857 .bind = bind, 1858 .connect = connect, 1859 .socketpair = sock_no_socketpair, 1860 .accept = sock_no_accept, 1861 .getname = get_name, 1862 .poll = poll, 1863 .ioctl = sock_no_ioctl, 1864 .listen = sock_no_listen, 1865 .shutdown = shutdown, 1866 .setsockopt = setsockopt, 1867 .getsockopt = getsockopt, 1868 .sendmsg = send_msg, 1869 .recvmsg = recv_msg, 1870 .mmap = sock_no_mmap, 1871 .sendpage = sock_no_sendpage 1872 }; 1873 1874 static const struct proto_ops packet_ops = { 1875 .owner = THIS_MODULE, 1876 .family = AF_TIPC, 1877 .release = release, 1878 .bind = bind, 1879 .connect = connect, 1880 .socketpair = sock_no_socketpair, 1881 .accept = accept, 1882 .getname = get_name, 1883 .poll = poll, 1884 .ioctl = sock_no_ioctl, 1885 .listen = listen, 1886 .shutdown = shutdown, 1887 .setsockopt = setsockopt, 1888 .getsockopt = getsockopt, 1889 .sendmsg = send_packet, 1890 .recvmsg = recv_msg, 1891 .mmap = sock_no_mmap, 1892 .sendpage = sock_no_sendpage 1893 }; 1894 1895 static const struct proto_ops stream_ops = { 1896 .owner = THIS_MODULE, 1897 .family = AF_TIPC, 1898 .release = release, 1899 .bind = bind, 1900 .connect = connect, 1901 .socketpair = sock_no_socketpair, 1902 .accept = accept, 1903 .getname = get_name, 1904 .poll = poll, 1905 .ioctl = sock_no_ioctl, 1906 .listen = listen, 1907 .shutdown = shutdown, 1908 .setsockopt = setsockopt, 1909 .getsockopt = getsockopt, 1910 .sendmsg = send_stream, 1911 .recvmsg = recv_stream, 1912 .mmap = sock_no_mmap, 1913 .sendpage = sock_no_sendpage 1914 }; 1915 1916 static const struct net_proto_family tipc_family_ops = { 1917 .owner = THIS_MODULE, 1918 .family = AF_TIPC, 1919 .create = tipc_sk_create 1920 }; 1921 1922 static struct proto tipc_proto = { 1923 .name = "TIPC", 1924 .owner = THIS_MODULE, 1925 .obj_size = sizeof(struct tipc_sock), 1926 .sysctl_rmem = sysctl_tipc_rmem 1927 }; 1928 1929 static struct proto tipc_proto_kern = { 1930 .name = "TIPC", 1931 .obj_size = sizeof(struct tipc_sock), 1932 .sysctl_rmem = sysctl_tipc_rmem 1933 }; 1934 1935 /** 1936 * tipc_socket_init - initialize TIPC socket interface 1937 * 1938 * Returns 0 on success, errno otherwise 1939 */ 1940 int tipc_socket_init(void) 1941 { 1942 int res; 1943 1944 res = proto_register(&tipc_proto, 1); 1945 if (res) { 1946 pr_err("Failed to register TIPC protocol type\n"); 1947 goto out; 1948 } 1949 1950 res = sock_register(&tipc_family_ops); 1951 if (res) { 1952 pr_err("Failed to register TIPC socket type\n"); 1953 proto_unregister(&tipc_proto); 1954 goto out; 1955 } 1956 1957 sockets_enabled = 1; 1958 out: 1959 return res; 1960 } 1961 1962 /** 1963 * tipc_socket_stop - stop TIPC socket interface 1964 */ 1965 void tipc_socket_stop(void) 1966 { 1967 if (!sockets_enabled) 1968 return; 1969 1970 sockets_enabled = 0; 1971 sock_unregister(tipc_family_ops.family); 1972 proto_unregister(&tipc_proto); 1973 } 1974