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 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 984 restart: 985 986 /* Look for a message in receive queue; wait if necessary */ 987 while (skb_queue_empty(&sk->sk_receive_queue)) { 988 if (sock->state == SS_DISCONNECTING) { 989 res = -ENOTCONN; 990 goto exit; 991 } 992 if (timeout <= 0L) { 993 res = timeout ? timeout : -EWOULDBLOCK; 994 goto exit; 995 } 996 release_sock(sk); 997 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 998 tipc_rx_ready(sock), 999 timeout); 1000 lock_sock(sk); 1001 } 1002 1003 /* Look at first message in receive queue */ 1004 buf = skb_peek(&sk->sk_receive_queue); 1005 msg = buf_msg(buf); 1006 sz = msg_data_sz(msg); 1007 err = msg_errcode(msg); 1008 1009 /* Discard an empty non-errored message & try again */ 1010 if ((!sz) && (!err)) { 1011 advance_rx_queue(sk); 1012 goto restart; 1013 } 1014 1015 /* Capture sender's address (optional) */ 1016 set_orig_addr(m, msg); 1017 1018 /* Capture ancillary data (optional) */ 1019 res = anc_data_recv(m, msg, tport); 1020 if (res) 1021 goto exit; 1022 1023 /* Capture message data (if valid) & compute return value (always) */ 1024 if (!err) { 1025 if (unlikely(buf_len < sz)) { 1026 sz = buf_len; 1027 m->msg_flags |= MSG_TRUNC; 1028 } 1029 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg), 1030 m->msg_iov, sz); 1031 if (res) 1032 goto exit; 1033 res = sz; 1034 } else { 1035 if ((sock->state == SS_READY) || 1036 ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)) 1037 res = 0; 1038 else 1039 res = -ECONNRESET; 1040 } 1041 1042 /* Consume received message (optional) */ 1043 if (likely(!(flags & MSG_PEEK))) { 1044 if ((sock->state != SS_READY) && 1045 (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1046 tipc_acknowledge(tport->ref, tport->conn_unacked); 1047 advance_rx_queue(sk); 1048 } 1049 exit: 1050 release_sock(sk); 1051 return res; 1052 } 1053 1054 /** 1055 * recv_stream - receive stream-oriented data 1056 * @iocb: (unused) 1057 * @m: descriptor for message info 1058 * @buf_len: total size of user buffer area 1059 * @flags: receive flags 1060 * 1061 * Used for SOCK_STREAM messages only. If not enough data is available 1062 * will optionally wait for more; never truncates data. 1063 * 1064 * Returns size of returned message data, errno otherwise 1065 */ 1066 static int recv_stream(struct kiocb *iocb, struct socket *sock, 1067 struct msghdr *m, size_t buf_len, int flags) 1068 { 1069 struct sock *sk = sock->sk; 1070 struct tipc_port *tport = tipc_sk_port(sk); 1071 struct sk_buff *buf; 1072 struct tipc_msg *msg; 1073 long timeout; 1074 unsigned int sz; 1075 int sz_to_copy, target, needed; 1076 int sz_copied = 0; 1077 u32 err; 1078 int res = 0; 1079 1080 /* Catch invalid receive attempts */ 1081 if (unlikely(!buf_len)) 1082 return -EINVAL; 1083 1084 lock_sock(sk); 1085 1086 if (unlikely((sock->state == SS_UNCONNECTED))) { 1087 res = -ENOTCONN; 1088 goto exit; 1089 } 1090 1091 target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len); 1092 timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1093 1094 restart: 1095 /* Look for a message in receive queue; wait if necessary */ 1096 while (skb_queue_empty(&sk->sk_receive_queue)) { 1097 if (sock->state == SS_DISCONNECTING) { 1098 res = -ENOTCONN; 1099 goto exit; 1100 } 1101 if (timeout <= 0L) { 1102 res = timeout ? timeout : -EWOULDBLOCK; 1103 goto exit; 1104 } 1105 release_sock(sk); 1106 timeout = wait_event_interruptible_timeout(*sk_sleep(sk), 1107 tipc_rx_ready(sock), 1108 timeout); 1109 lock_sock(sk); 1110 } 1111 1112 /* Look at first message in receive queue */ 1113 buf = skb_peek(&sk->sk_receive_queue); 1114 msg = buf_msg(buf); 1115 sz = msg_data_sz(msg); 1116 err = msg_errcode(msg); 1117 1118 /* Discard an empty non-errored message & try again */ 1119 if ((!sz) && (!err)) { 1120 advance_rx_queue(sk); 1121 goto restart; 1122 } 1123 1124 /* Optionally capture sender's address & ancillary data of first msg */ 1125 if (sz_copied == 0) { 1126 set_orig_addr(m, msg); 1127 res = anc_data_recv(m, msg, tport); 1128 if (res) 1129 goto exit; 1130 } 1131 1132 /* Capture message data (if valid) & compute return value (always) */ 1133 if (!err) { 1134 u32 offset = (u32)(unsigned long)(TIPC_SKB_CB(buf)->handle); 1135 1136 sz -= offset; 1137 needed = (buf_len - sz_copied); 1138 sz_to_copy = (sz <= needed) ? sz : needed; 1139 1140 res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg) + offset, 1141 m->msg_iov, sz_to_copy); 1142 if (res) 1143 goto exit; 1144 1145 sz_copied += sz_to_copy; 1146 1147 if (sz_to_copy < sz) { 1148 if (!(flags & MSG_PEEK)) 1149 TIPC_SKB_CB(buf)->handle = 1150 (void *)(unsigned long)(offset + sz_to_copy); 1151 goto exit; 1152 } 1153 } else { 1154 if (sz_copied != 0) 1155 goto exit; /* can't add error msg to valid data */ 1156 1157 if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control) 1158 res = 0; 1159 else 1160 res = -ECONNRESET; 1161 } 1162 1163 /* Consume received message (optional) */ 1164 if (likely(!(flags & MSG_PEEK))) { 1165 if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN)) 1166 tipc_acknowledge(tport->ref, tport->conn_unacked); 1167 advance_rx_queue(sk); 1168 } 1169 1170 /* Loop around if more data is required */ 1171 if ((sz_copied < buf_len) && /* didn't get all requested data */ 1172 (!skb_queue_empty(&sk->sk_receive_queue) || 1173 (sz_copied < target)) && /* and more is ready or required */ 1174 (!(flags & MSG_PEEK)) && /* and aren't just peeking at data */ 1175 (!err)) /* and haven't reached a FIN */ 1176 goto restart; 1177 1178 exit: 1179 release_sock(sk); 1180 return sz_copied ? sz_copied : res; 1181 } 1182 1183 /** 1184 * tipc_write_space - wake up thread if port congestion is released 1185 * @sk: socket 1186 */ 1187 static void tipc_write_space(struct sock *sk) 1188 { 1189 struct socket_wq *wq; 1190 1191 rcu_read_lock(); 1192 wq = rcu_dereference(sk->sk_wq); 1193 if (wq_has_sleeper(wq)) 1194 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | 1195 POLLWRNORM | POLLWRBAND); 1196 rcu_read_unlock(); 1197 } 1198 1199 /** 1200 * tipc_data_ready - wake up threads to indicate messages have been received 1201 * @sk: socket 1202 * @len: the length of messages 1203 */ 1204 static void tipc_data_ready(struct sock *sk, int len) 1205 { 1206 struct socket_wq *wq; 1207 1208 rcu_read_lock(); 1209 wq = rcu_dereference(sk->sk_wq); 1210 if (wq_has_sleeper(wq)) 1211 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | 1212 POLLRDNORM | POLLRDBAND); 1213 rcu_read_unlock(); 1214 } 1215 1216 /** 1217 * filter_connect - Handle all incoming messages for a connection-based socket 1218 * @tsock: TIPC socket 1219 * @msg: message 1220 * 1221 * Returns TIPC error status code and socket error status code 1222 * once it encounters some errors 1223 */ 1224 static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf) 1225 { 1226 struct socket *sock = tsock->sk.sk_socket; 1227 struct tipc_msg *msg = buf_msg(*buf); 1228 struct sock *sk = &tsock->sk; 1229 u32 retval = TIPC_ERR_NO_PORT; 1230 int res; 1231 1232 if (msg_mcast(msg)) 1233 return retval; 1234 1235 switch ((int)sock->state) { 1236 case SS_CONNECTED: 1237 /* Accept only connection-based messages sent by peer */ 1238 if (msg_connected(msg) && tipc_port_peer_msg(tsock->p, msg)) { 1239 if (unlikely(msg_errcode(msg))) { 1240 sock->state = SS_DISCONNECTING; 1241 __tipc_disconnect(tsock->p); 1242 } 1243 retval = TIPC_OK; 1244 } 1245 break; 1246 case SS_CONNECTING: 1247 /* Accept only ACK or NACK message */ 1248 if (unlikely(msg_errcode(msg))) { 1249 sock->state = SS_DISCONNECTING; 1250 sk->sk_err = ECONNREFUSED; 1251 retval = TIPC_OK; 1252 break; 1253 } 1254 1255 if (unlikely(!msg_connected(msg))) 1256 break; 1257 1258 res = auto_connect(sock, msg); 1259 if (res) { 1260 sock->state = SS_DISCONNECTING; 1261 sk->sk_err = -res; 1262 retval = TIPC_OK; 1263 break; 1264 } 1265 1266 /* If an incoming message is an 'ACK-', it should be 1267 * discarded here because it doesn't contain useful 1268 * data. In addition, we should try to wake up 1269 * connect() routine if sleeping. 1270 */ 1271 if (msg_data_sz(msg) == 0) { 1272 kfree_skb(*buf); 1273 *buf = NULL; 1274 if (waitqueue_active(sk_sleep(sk))) 1275 wake_up_interruptible(sk_sleep(sk)); 1276 } 1277 retval = TIPC_OK; 1278 break; 1279 case SS_LISTENING: 1280 case SS_UNCONNECTED: 1281 /* Accept only SYN message */ 1282 if (!msg_connected(msg) && !(msg_errcode(msg))) 1283 retval = TIPC_OK; 1284 break; 1285 case SS_DISCONNECTING: 1286 break; 1287 default: 1288 pr_err("Unknown socket state %u\n", sock->state); 1289 } 1290 return retval; 1291 } 1292 1293 /** 1294 * rcvbuf_limit - get proper overload limit of socket receive queue 1295 * @sk: socket 1296 * @buf: message 1297 * 1298 * For all connection oriented messages, irrespective of importance, 1299 * the default overload value (i.e. 67MB) is set as limit. 1300 * 1301 * For all connectionless messages, by default new queue limits are 1302 * as belows: 1303 * 1304 * TIPC_LOW_IMPORTANCE (4 MB) 1305 * TIPC_MEDIUM_IMPORTANCE (8 MB) 1306 * TIPC_HIGH_IMPORTANCE (16 MB) 1307 * TIPC_CRITICAL_IMPORTANCE (32 MB) 1308 * 1309 * Returns overload limit according to corresponding message importance 1310 */ 1311 static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf) 1312 { 1313 struct tipc_msg *msg = buf_msg(buf); 1314 unsigned int limit; 1315 1316 if (msg_connected(msg)) 1317 limit = sysctl_tipc_rmem[2]; 1318 else 1319 limit = sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE << 1320 msg_importance(msg); 1321 return limit; 1322 } 1323 1324 /** 1325 * filter_rcv - validate incoming message 1326 * @sk: socket 1327 * @buf: message 1328 * 1329 * Enqueues message on receive queue if acceptable; optionally handles 1330 * disconnect indication for a connected socket. 1331 * 1332 * Called with socket lock already taken; port lock may also be taken. 1333 * 1334 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1335 */ 1336 static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) 1337 { 1338 struct socket *sock = sk->sk_socket; 1339 struct tipc_msg *msg = buf_msg(buf); 1340 unsigned int limit = rcvbuf_limit(sk, buf); 1341 u32 res = TIPC_OK; 1342 1343 /* Reject message if it is wrong sort of message for socket */ 1344 if (msg_type(msg) > TIPC_DIRECT_MSG) 1345 return TIPC_ERR_NO_PORT; 1346 1347 if (sock->state == SS_READY) { 1348 if (msg_connected(msg)) 1349 return TIPC_ERR_NO_PORT; 1350 } else { 1351 res = filter_connect(tipc_sk(sk), &buf); 1352 if (res != TIPC_OK || buf == NULL) 1353 return res; 1354 } 1355 1356 /* Reject message if there isn't room to queue it */ 1357 if (sk_rmem_alloc_get(sk) + buf->truesize >= limit) 1358 return TIPC_ERR_OVERLOAD; 1359 1360 /* Enqueue message */ 1361 TIPC_SKB_CB(buf)->handle = NULL; 1362 __skb_queue_tail(&sk->sk_receive_queue, buf); 1363 skb_set_owner_r(buf, sk); 1364 1365 sk->sk_data_ready(sk, 0); 1366 return TIPC_OK; 1367 } 1368 1369 /** 1370 * backlog_rcv - handle incoming message from backlog queue 1371 * @sk: socket 1372 * @buf: message 1373 * 1374 * Caller must hold socket lock, but not port lock. 1375 * 1376 * Returns 0 1377 */ 1378 static int backlog_rcv(struct sock *sk, struct sk_buff *buf) 1379 { 1380 u32 res; 1381 1382 res = filter_rcv(sk, buf); 1383 if (res) 1384 tipc_reject_msg(buf, res); 1385 return 0; 1386 } 1387 1388 /** 1389 * dispatch - handle incoming message 1390 * @tport: TIPC port that received message 1391 * @buf: message 1392 * 1393 * Called with port lock already taken. 1394 * 1395 * Returns TIPC error status code (TIPC_OK if message is not to be rejected) 1396 */ 1397 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf) 1398 { 1399 struct sock *sk = tport->sk; 1400 u32 res; 1401 1402 /* 1403 * Process message if socket is unlocked; otherwise add to backlog queue 1404 * 1405 * This code is based on sk_receive_skb(), but must be distinct from it 1406 * since a TIPC-specific filter/reject mechanism is utilized 1407 */ 1408 bh_lock_sock(sk); 1409 if (!sock_owned_by_user(sk)) { 1410 res = filter_rcv(sk, buf); 1411 } else { 1412 if (sk_add_backlog(sk, buf, rcvbuf_limit(sk, buf))) 1413 res = TIPC_ERR_OVERLOAD; 1414 else 1415 res = TIPC_OK; 1416 } 1417 bh_unlock_sock(sk); 1418 1419 return res; 1420 } 1421 1422 /** 1423 * wakeupdispatch - wake up port after congestion 1424 * @tport: port to wakeup 1425 * 1426 * Called with port lock already taken. 1427 */ 1428 static void wakeupdispatch(struct tipc_port *tport) 1429 { 1430 struct sock *sk = tport->sk; 1431 1432 sk->sk_write_space(sk); 1433 } 1434 1435 /** 1436 * connect - establish a connection to another TIPC port 1437 * @sock: socket structure 1438 * @dest: socket address for destination port 1439 * @destlen: size of socket address data structure 1440 * @flags: file-related flags associated with socket 1441 * 1442 * Returns 0 on success, errno otherwise 1443 */ 1444 static int connect(struct socket *sock, struct sockaddr *dest, int destlen, 1445 int flags) 1446 { 1447 struct sock *sk = sock->sk; 1448 struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest; 1449 struct msghdr m = {NULL,}; 1450 unsigned int timeout; 1451 int res; 1452 1453 lock_sock(sk); 1454 1455 /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */ 1456 if (sock->state == SS_READY) { 1457 res = -EOPNOTSUPP; 1458 goto exit; 1459 } 1460 1461 /* 1462 * Reject connection attempt using multicast address 1463 * 1464 * Note: send_msg() validates the rest of the address fields, 1465 * so there's no need to do it here 1466 */ 1467 if (dst->addrtype == TIPC_ADDR_MCAST) { 1468 res = -EINVAL; 1469 goto exit; 1470 } 1471 1472 timeout = (flags & O_NONBLOCK) ? 0 : tipc_sk(sk)->conn_timeout; 1473 1474 switch (sock->state) { 1475 case SS_UNCONNECTED: 1476 /* Send a 'SYN-' to destination */ 1477 m.msg_name = dest; 1478 m.msg_namelen = destlen; 1479 1480 /* If connect is in non-blocking case, set MSG_DONTWAIT to 1481 * indicate send_msg() is never blocked. 1482 */ 1483 if (!timeout) 1484 m.msg_flags = MSG_DONTWAIT; 1485 1486 res = send_msg(NULL, sock, &m, 0); 1487 if ((res < 0) && (res != -EWOULDBLOCK)) 1488 goto exit; 1489 1490 /* Just entered SS_CONNECTING state; the only 1491 * difference is that return value in non-blocking 1492 * case is EINPROGRESS, rather than EALREADY. 1493 */ 1494 res = -EINPROGRESS; 1495 break; 1496 case SS_CONNECTING: 1497 res = -EALREADY; 1498 break; 1499 case SS_CONNECTED: 1500 res = -EISCONN; 1501 break; 1502 default: 1503 res = -EINVAL; 1504 goto exit; 1505 } 1506 1507 if (sock->state == SS_CONNECTING) { 1508 if (!timeout) 1509 goto exit; 1510 1511 /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */ 1512 release_sock(sk); 1513 res = wait_event_interruptible_timeout(*sk_sleep(sk), 1514 sock->state != SS_CONNECTING, 1515 timeout ? (long)msecs_to_jiffies(timeout) 1516 : MAX_SCHEDULE_TIMEOUT); 1517 lock_sock(sk); 1518 if (res <= 0) { 1519 if (res == 0) 1520 res = -ETIMEDOUT; 1521 else 1522 ; /* leave "res" unchanged */ 1523 goto exit; 1524 } 1525 } 1526 1527 if (unlikely(sock->state == SS_DISCONNECTING)) 1528 res = sock_error(sk); 1529 else 1530 res = 0; 1531 1532 exit: 1533 release_sock(sk); 1534 return res; 1535 } 1536 1537 /** 1538 * listen - allow socket to listen for incoming connections 1539 * @sock: socket structure 1540 * @len: (unused) 1541 * 1542 * Returns 0 on success, errno otherwise 1543 */ 1544 static int listen(struct socket *sock, int len) 1545 { 1546 struct sock *sk = sock->sk; 1547 int res; 1548 1549 lock_sock(sk); 1550 1551 if (sock->state != SS_UNCONNECTED) 1552 res = -EINVAL; 1553 else { 1554 sock->state = SS_LISTENING; 1555 res = 0; 1556 } 1557 1558 release_sock(sk); 1559 return res; 1560 } 1561 1562 /** 1563 * accept - wait for connection request 1564 * @sock: listening socket 1565 * @newsock: new socket that is to be connected 1566 * @flags: file-related flags associated with socket 1567 * 1568 * Returns 0 on success, errno otherwise 1569 */ 1570 static int accept(struct socket *sock, struct socket *new_sock, int flags) 1571 { 1572 struct sock *new_sk, *sk = sock->sk; 1573 struct sk_buff *buf; 1574 struct tipc_sock *new_tsock; 1575 struct tipc_port *new_tport; 1576 struct tipc_msg *msg; 1577 u32 new_ref; 1578 1579 int res; 1580 1581 lock_sock(sk); 1582 1583 if (sock->state != SS_LISTENING) { 1584 res = -EINVAL; 1585 goto exit; 1586 } 1587 1588 while (skb_queue_empty(&sk->sk_receive_queue)) { 1589 if (flags & O_NONBLOCK) { 1590 res = -EWOULDBLOCK; 1591 goto exit; 1592 } 1593 release_sock(sk); 1594 res = wait_event_interruptible(*sk_sleep(sk), 1595 (!skb_queue_empty(&sk->sk_receive_queue))); 1596 lock_sock(sk); 1597 if (res) 1598 goto exit; 1599 } 1600 1601 buf = skb_peek(&sk->sk_receive_queue); 1602 1603 res = tipc_sk_create(sock_net(sock->sk), new_sock, 0, 1); 1604 if (res) 1605 goto exit; 1606 1607 new_sk = new_sock->sk; 1608 new_tsock = tipc_sk(new_sk); 1609 new_tport = new_tsock->p; 1610 new_ref = new_tport->ref; 1611 msg = buf_msg(buf); 1612 1613 /* we lock on new_sk; but lockdep sees the lock on sk */ 1614 lock_sock_nested(new_sk, SINGLE_DEPTH_NESTING); 1615 1616 /* 1617 * Reject any stray messages received by new socket 1618 * before the socket lock was taken (very, very unlikely) 1619 */ 1620 reject_rx_queue(new_sk); 1621 1622 /* Connect new socket to it's peer */ 1623 new_tsock->peer_name.ref = msg_origport(msg); 1624 new_tsock->peer_name.node = msg_orignode(msg); 1625 tipc_connect(new_ref, &new_tsock->peer_name); 1626 new_sock->state = SS_CONNECTED; 1627 1628 tipc_set_portimportance(new_ref, msg_importance(msg)); 1629 if (msg_named(msg)) { 1630 new_tport->conn_type = msg_nametype(msg); 1631 new_tport->conn_instance = msg_nameinst(msg); 1632 } 1633 1634 /* 1635 * Respond to 'SYN-' by discarding it & returning 'ACK'-. 1636 * Respond to 'SYN+' by queuing it on new socket. 1637 */ 1638 if (!msg_data_sz(msg)) { 1639 struct msghdr m = {NULL,}; 1640 1641 advance_rx_queue(sk); 1642 send_packet(NULL, new_sock, &m, 0); 1643 } else { 1644 __skb_dequeue(&sk->sk_receive_queue); 1645 __skb_queue_head(&new_sk->sk_receive_queue, buf); 1646 skb_set_owner_r(buf, new_sk); 1647 } 1648 release_sock(new_sk); 1649 1650 exit: 1651 release_sock(sk); 1652 return res; 1653 } 1654 1655 /** 1656 * shutdown - shutdown socket connection 1657 * @sock: socket structure 1658 * @how: direction to close (must be SHUT_RDWR) 1659 * 1660 * Terminates connection (if necessary), then purges socket's receive queue. 1661 * 1662 * Returns 0 on success, errno otherwise 1663 */ 1664 static int shutdown(struct socket *sock, int how) 1665 { 1666 struct sock *sk = sock->sk; 1667 struct tipc_port *tport = tipc_sk_port(sk); 1668 struct sk_buff *buf; 1669 int res; 1670 1671 if (how != SHUT_RDWR) 1672 return -EINVAL; 1673 1674 lock_sock(sk); 1675 1676 switch (sock->state) { 1677 case SS_CONNECTING: 1678 case SS_CONNECTED: 1679 1680 restart: 1681 /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */ 1682 buf = __skb_dequeue(&sk->sk_receive_queue); 1683 if (buf) { 1684 if (TIPC_SKB_CB(buf)->handle != NULL) { 1685 kfree_skb(buf); 1686 goto restart; 1687 } 1688 tipc_disconnect(tport->ref); 1689 tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); 1690 } else { 1691 tipc_shutdown(tport->ref); 1692 } 1693 1694 sock->state = SS_DISCONNECTING; 1695 1696 /* fall through */ 1697 1698 case SS_DISCONNECTING: 1699 1700 /* Discard any unreceived messages */ 1701 __skb_queue_purge(&sk->sk_receive_queue); 1702 1703 /* Wake up anyone sleeping in poll */ 1704 sk->sk_state_change(sk); 1705 res = 0; 1706 break; 1707 1708 default: 1709 res = -ENOTCONN; 1710 } 1711 1712 release_sock(sk); 1713 return res; 1714 } 1715 1716 /** 1717 * setsockopt - set socket option 1718 * @sock: socket structure 1719 * @lvl: option level 1720 * @opt: option identifier 1721 * @ov: pointer to new option value 1722 * @ol: length of option value 1723 * 1724 * For stream sockets only, accepts and ignores all IPPROTO_TCP options 1725 * (to ease compatibility). 1726 * 1727 * Returns 0 on success, errno otherwise 1728 */ 1729 static int setsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1730 unsigned int ol) 1731 { 1732 struct sock *sk = sock->sk; 1733 struct tipc_port *tport = tipc_sk_port(sk); 1734 u32 value; 1735 int res; 1736 1737 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1738 return 0; 1739 if (lvl != SOL_TIPC) 1740 return -ENOPROTOOPT; 1741 if (ol < sizeof(value)) 1742 return -EINVAL; 1743 res = get_user(value, (u32 __user *)ov); 1744 if (res) 1745 return res; 1746 1747 lock_sock(sk); 1748 1749 switch (opt) { 1750 case TIPC_IMPORTANCE: 1751 res = tipc_set_portimportance(tport->ref, value); 1752 break; 1753 case TIPC_SRC_DROPPABLE: 1754 if (sock->type != SOCK_STREAM) 1755 res = tipc_set_portunreliable(tport->ref, value); 1756 else 1757 res = -ENOPROTOOPT; 1758 break; 1759 case TIPC_DEST_DROPPABLE: 1760 res = tipc_set_portunreturnable(tport->ref, value); 1761 break; 1762 case TIPC_CONN_TIMEOUT: 1763 tipc_sk(sk)->conn_timeout = value; 1764 /* no need to set "res", since already 0 at this point */ 1765 break; 1766 default: 1767 res = -EINVAL; 1768 } 1769 1770 release_sock(sk); 1771 1772 return res; 1773 } 1774 1775 /** 1776 * getsockopt - get socket option 1777 * @sock: socket structure 1778 * @lvl: option level 1779 * @opt: option identifier 1780 * @ov: receptacle for option value 1781 * @ol: receptacle for length of option value 1782 * 1783 * For stream sockets only, returns 0 length result for all IPPROTO_TCP options 1784 * (to ease compatibility). 1785 * 1786 * Returns 0 on success, errno otherwise 1787 */ 1788 static int getsockopt(struct socket *sock, int lvl, int opt, char __user *ov, 1789 int __user *ol) 1790 { 1791 struct sock *sk = sock->sk; 1792 struct tipc_port *tport = tipc_sk_port(sk); 1793 int len; 1794 u32 value; 1795 int res; 1796 1797 if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM)) 1798 return put_user(0, ol); 1799 if (lvl != SOL_TIPC) 1800 return -ENOPROTOOPT; 1801 res = get_user(len, ol); 1802 if (res) 1803 return res; 1804 1805 lock_sock(sk); 1806 1807 switch (opt) { 1808 case TIPC_IMPORTANCE: 1809 res = tipc_portimportance(tport->ref, &value); 1810 break; 1811 case TIPC_SRC_DROPPABLE: 1812 res = tipc_portunreliable(tport->ref, &value); 1813 break; 1814 case TIPC_DEST_DROPPABLE: 1815 res = tipc_portunreturnable(tport->ref, &value); 1816 break; 1817 case TIPC_CONN_TIMEOUT: 1818 value = tipc_sk(sk)->conn_timeout; 1819 /* no need to set "res", since already 0 at this point */ 1820 break; 1821 case TIPC_NODE_RECVQ_DEPTH: 1822 value = 0; /* was tipc_queue_size, now obsolete */ 1823 break; 1824 case TIPC_SOCK_RECVQ_DEPTH: 1825 value = skb_queue_len(&sk->sk_receive_queue); 1826 break; 1827 default: 1828 res = -EINVAL; 1829 } 1830 1831 release_sock(sk); 1832 1833 if (res) 1834 return res; /* "get" failed */ 1835 1836 if (len < sizeof(value)) 1837 return -EINVAL; 1838 1839 if (copy_to_user(ov, &value, sizeof(value))) 1840 return -EFAULT; 1841 1842 return put_user(sizeof(value), ol); 1843 } 1844 1845 /* Protocol switches for the various types of TIPC sockets */ 1846 1847 static const struct proto_ops msg_ops = { 1848 .owner = THIS_MODULE, 1849 .family = AF_TIPC, 1850 .release = release, 1851 .bind = bind, 1852 .connect = connect, 1853 .socketpair = sock_no_socketpair, 1854 .accept = sock_no_accept, 1855 .getname = get_name, 1856 .poll = poll, 1857 .ioctl = sock_no_ioctl, 1858 .listen = sock_no_listen, 1859 .shutdown = shutdown, 1860 .setsockopt = setsockopt, 1861 .getsockopt = getsockopt, 1862 .sendmsg = send_msg, 1863 .recvmsg = recv_msg, 1864 .mmap = sock_no_mmap, 1865 .sendpage = sock_no_sendpage 1866 }; 1867 1868 static const struct proto_ops packet_ops = { 1869 .owner = THIS_MODULE, 1870 .family = AF_TIPC, 1871 .release = release, 1872 .bind = bind, 1873 .connect = connect, 1874 .socketpair = sock_no_socketpair, 1875 .accept = accept, 1876 .getname = get_name, 1877 .poll = poll, 1878 .ioctl = sock_no_ioctl, 1879 .listen = listen, 1880 .shutdown = shutdown, 1881 .setsockopt = setsockopt, 1882 .getsockopt = getsockopt, 1883 .sendmsg = send_packet, 1884 .recvmsg = recv_msg, 1885 .mmap = sock_no_mmap, 1886 .sendpage = sock_no_sendpage 1887 }; 1888 1889 static const struct proto_ops stream_ops = { 1890 .owner = THIS_MODULE, 1891 .family = AF_TIPC, 1892 .release = release, 1893 .bind = bind, 1894 .connect = connect, 1895 .socketpair = sock_no_socketpair, 1896 .accept = accept, 1897 .getname = get_name, 1898 .poll = poll, 1899 .ioctl = sock_no_ioctl, 1900 .listen = listen, 1901 .shutdown = shutdown, 1902 .setsockopt = setsockopt, 1903 .getsockopt = getsockopt, 1904 .sendmsg = send_stream, 1905 .recvmsg = recv_stream, 1906 .mmap = sock_no_mmap, 1907 .sendpage = sock_no_sendpage 1908 }; 1909 1910 static const struct net_proto_family tipc_family_ops = { 1911 .owner = THIS_MODULE, 1912 .family = AF_TIPC, 1913 .create = tipc_sk_create 1914 }; 1915 1916 static struct proto tipc_proto = { 1917 .name = "TIPC", 1918 .owner = THIS_MODULE, 1919 .obj_size = sizeof(struct tipc_sock), 1920 .sysctl_rmem = sysctl_tipc_rmem 1921 }; 1922 1923 static struct proto tipc_proto_kern = { 1924 .name = "TIPC", 1925 .obj_size = sizeof(struct tipc_sock), 1926 .sysctl_rmem = sysctl_tipc_rmem 1927 }; 1928 1929 /** 1930 * tipc_socket_init - initialize TIPC socket interface 1931 * 1932 * Returns 0 on success, errno otherwise 1933 */ 1934 int tipc_socket_init(void) 1935 { 1936 int res; 1937 1938 res = proto_register(&tipc_proto, 1); 1939 if (res) { 1940 pr_err("Failed to register TIPC protocol type\n"); 1941 goto out; 1942 } 1943 1944 res = sock_register(&tipc_family_ops); 1945 if (res) { 1946 pr_err("Failed to register TIPC socket type\n"); 1947 proto_unregister(&tipc_proto); 1948 goto out; 1949 } 1950 1951 sockets_enabled = 1; 1952 out: 1953 return res; 1954 } 1955 1956 /** 1957 * tipc_socket_stop - stop TIPC socket interface 1958 */ 1959 void tipc_socket_stop(void) 1960 { 1961 if (!sockets_enabled) 1962 return; 1963 1964 sockets_enabled = 0; 1965 sock_unregister(tipc_family_ops.family); 1966 proto_unregister(&tipc_proto); 1967 } 1968