xref: /linux/net/tipc/socket.c (revision 6ab3d5624e172c553004ecc862bfeac16d9d68b7)
1 /*
2  * net/tipc/socket.c: TIPC socket API
3  *
4  * Copyright (c) 2001-2006, Ericsson AB
5  * Copyright (c) 2004-2005, 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 <linux/module.h>
38 #include <linux/types.h>
39 #include <linux/net.h>
40 #include <linux/socket.h>
41 #include <linux/errno.h>
42 #include <linux/mm.h>
43 #include <linux/slab.h>
44 #include <linux/poll.h>
45 #include <linux/fcntl.h>
46 #include <asm/semaphore.h>
47 #include <asm/string.h>
48 #include <asm/atomic.h>
49 #include <net/sock.h>
50 
51 #include <linux/tipc.h>
52 #include <linux/tipc_config.h>
53 #include <net/tipc/tipc_msg.h>
54 #include <net/tipc/tipc_port.h>
55 
56 #include "core.h"
57 
58 #define SS_LISTENING	-1	/* socket is listening */
59 #define SS_READY	-2	/* socket is connectionless */
60 
61 #define OVERLOAD_LIMIT_BASE    5000
62 
63 struct tipc_sock {
64 	struct sock sk;
65 	struct tipc_port *p;
66 	struct semaphore sem;
67 };
68 
69 #define tipc_sk(sk) ((struct tipc_sock*)sk)
70 
71 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
72 static void wakeupdispatch(struct tipc_port *tport);
73 
74 static struct proto_ops packet_ops;
75 static struct proto_ops stream_ops;
76 static struct proto_ops msg_ops;
77 
78 static struct proto tipc_proto;
79 
80 static int sockets_enabled = 0;
81 
82 static atomic_t tipc_queue_size = ATOMIC_INIT(0);
83 
84 
85 /*
86  * sock_lock(): Lock a port/socket pair. lock_sock() can
87  * not be used here, since the same lock must protect ports
88  * with non-socket interfaces.
89  * See net.c for description of locking policy.
90  */
91 static void sock_lock(struct tipc_sock* tsock)
92 {
93         spin_lock_bh(tsock->p->lock);
94 }
95 
96 /*
97  * sock_unlock(): Unlock a port/socket pair
98  */
99 static void sock_unlock(struct tipc_sock* tsock)
100 {
101         spin_unlock_bh(tsock->p->lock);
102 }
103 
104 /**
105  * pollmask - determine the current set of poll() events for a socket
106  * @sock: socket structure
107  *
108  * TIPC sets the returned events as follows:
109  * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
110  *    or if a connection-oriented socket is does not have an active connection
111  *    (i.e. a read operation will not block).
112  * b) POLLOUT is set except when a socket's connection has been terminated
113  *    (i.e. a write operation will not block).
114  * c) POLLHUP is set when a socket's connection has been terminated.
115  *
116  * IMPORTANT: The fact that a read or write operation will not block does NOT
117  * imply that the operation will succeed!
118  *
119  * Returns pollmask value
120  */
121 
122 static u32 pollmask(struct socket *sock)
123 {
124 	u32 mask;
125 
126 	if ((skb_queue_len(&sock->sk->sk_receive_queue) != 0) ||
127 	    (sock->state == SS_UNCONNECTED) ||
128 	    (sock->state == SS_DISCONNECTING))
129 		mask = (POLLRDNORM | POLLIN);
130 	else
131 		mask = 0;
132 
133 	if (sock->state == SS_DISCONNECTING)
134 		mask |= POLLHUP;
135 	else
136 		mask |= POLLOUT;
137 
138 	return mask;
139 }
140 
141 
142 /**
143  * advance_queue - discard first buffer in queue
144  * @tsock: TIPC socket
145  */
146 
147 static void advance_queue(struct tipc_sock *tsock)
148 {
149         sock_lock(tsock);
150 	buf_discard(skb_dequeue(&tsock->sk.sk_receive_queue));
151         sock_unlock(tsock);
152 	atomic_dec(&tipc_queue_size);
153 }
154 
155 /**
156  * tipc_create - create a TIPC socket
157  * @sock: pre-allocated socket structure
158  * @protocol: protocol indicator (must be 0)
159  *
160  * This routine creates and attaches a 'struct sock' to the 'struct socket',
161  * then create and attaches a TIPC port to the 'struct sock' part.
162  *
163  * Returns 0 on success, errno otherwise
164  */
165 static int tipc_create(struct socket *sock, int protocol)
166 {
167 	struct tipc_sock *tsock;
168 	struct tipc_port *port;
169 	struct sock *sk;
170         u32 ref;
171 
172 	if (unlikely(protocol != 0))
173 		return -EPROTONOSUPPORT;
174 
175 	ref = tipc_createport_raw(NULL, &dispatch, &wakeupdispatch, TIPC_LOW_IMPORTANCE);
176 	if (unlikely(!ref))
177 		return -ENOMEM;
178 
179 	sock->state = SS_UNCONNECTED;
180 
181 	switch (sock->type) {
182 	case SOCK_STREAM:
183 		sock->ops = &stream_ops;
184 		break;
185 	case SOCK_SEQPACKET:
186 		sock->ops = &packet_ops;
187 		break;
188 	case SOCK_DGRAM:
189 		tipc_set_portunreliable(ref, 1);
190 		/* fall through */
191 	case SOCK_RDM:
192 		tipc_set_portunreturnable(ref, 1);
193 		sock->ops = &msg_ops;
194 		sock->state = SS_READY;
195 		break;
196 	default:
197 		tipc_deleteport(ref);
198 		return -EPROTOTYPE;
199 	}
200 
201 	sk = sk_alloc(AF_TIPC, GFP_KERNEL, &tipc_proto, 1);
202 	if (!sk) {
203 		tipc_deleteport(ref);
204 		return -ENOMEM;
205 	}
206 
207 	sock_init_data(sock, sk);
208 	init_waitqueue_head(sk->sk_sleep);
209 	sk->sk_rcvtimeo = 8 * HZ;   /* default connect timeout = 8s */
210 
211 	tsock = tipc_sk(sk);
212 	port = tipc_get_port(ref);
213 
214 	tsock->p = port;
215 	port->usr_handle = tsock;
216 
217 	init_MUTEX(&tsock->sem);
218 
219 	dbg("sock_create: %x\n",tsock);
220 
221 	atomic_inc(&tipc_user_count);
222 
223 	return 0;
224 }
225 
226 /**
227  * release - destroy a TIPC socket
228  * @sock: socket to destroy
229  *
230  * This routine cleans up any messages that are still queued on the socket.
231  * For DGRAM and RDM socket types, all queued messages are rejected.
232  * For SEQPACKET and STREAM socket types, the first message is rejected
233  * and any others are discarded.  (If the first message on a STREAM socket
234  * is partially-read, it is discarded and the next one is rejected instead.)
235  *
236  * NOTE: Rejected messages are not necessarily returned to the sender!  They
237  * are returned or discarded according to the "destination droppable" setting
238  * specified for the message by the sender.
239  *
240  * Returns 0 on success, errno otherwise
241  */
242 
243 static int release(struct socket *sock)
244 {
245 	struct tipc_sock *tsock = tipc_sk(sock->sk);
246 	struct sock *sk = sock->sk;
247 	int res = TIPC_OK;
248 	struct sk_buff *buf;
249 
250         dbg("sock_delete: %x\n",tsock);
251 	if (!tsock)
252 		return 0;
253 	down_interruptible(&tsock->sem);
254 	if (!sock->sk) {
255 		up(&tsock->sem);
256 		return 0;
257 	}
258 
259 	/* Reject unreceived messages, unless no longer connected */
260 
261 	while (sock->state != SS_DISCONNECTING) {
262 		sock_lock(tsock);
263 		buf = skb_dequeue(&sk->sk_receive_queue);
264 		if (!buf)
265 			tsock->p->usr_handle = NULL;
266 		sock_unlock(tsock);
267 		if (!buf)
268 			break;
269 		if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf)))
270 			buf_discard(buf);
271 		else
272 			tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
273 		atomic_dec(&tipc_queue_size);
274 	}
275 
276 	/* Delete TIPC port */
277 
278 	res = tipc_deleteport(tsock->p->ref);
279 	sock->sk = NULL;
280 
281 	/* Discard any remaining messages */
282 
283 	while ((buf = skb_dequeue(&sk->sk_receive_queue))) {
284 		buf_discard(buf);
285 		atomic_dec(&tipc_queue_size);
286 	}
287 
288 	up(&tsock->sem);
289 
290 	sock_put(sk);
291 
292         atomic_dec(&tipc_user_count);
293 	return res;
294 }
295 
296 /**
297  * bind - associate or disassocate TIPC name(s) with a socket
298  * @sock: socket structure
299  * @uaddr: socket address describing name(s) and desired operation
300  * @uaddr_len: size of socket address data structure
301  *
302  * Name and name sequence binding is indicated using a positive scope value;
303  * a negative scope value unbinds the specified name.  Specifying no name
304  * (i.e. a socket address length of 0) unbinds all names from the socket.
305  *
306  * Returns 0 on success, errno otherwise
307  */
308 
309 static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
310 {
311 	struct tipc_sock *tsock = tipc_sk(sock->sk);
312 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
313 	int res;
314 
315 	if (down_interruptible(&tsock->sem))
316 		return -ERESTARTSYS;
317 
318 	if (unlikely(!uaddr_len)) {
319 		res = tipc_withdraw(tsock->p->ref, 0, NULL);
320 		goto exit;
321 	}
322 
323 	if (uaddr_len < sizeof(struct sockaddr_tipc)) {
324 		res = -EINVAL;
325 		goto exit;
326 	}
327 
328 	if (addr->family != AF_TIPC) {
329 		res = -EAFNOSUPPORT;
330 		goto exit;
331 	}
332 	if (addr->addrtype == TIPC_ADDR_NAME)
333 		addr->addr.nameseq.upper = addr->addr.nameseq.lower;
334 	else if (addr->addrtype != TIPC_ADDR_NAMESEQ) {
335 		res = -EAFNOSUPPORT;
336 		goto exit;
337 	}
338 
339        	if (addr->scope > 0)
340 		res = tipc_publish(tsock->p->ref, addr->scope,
341 				   &addr->addr.nameseq);
342 	else
343 		res = tipc_withdraw(tsock->p->ref, -addr->scope,
344 				    &addr->addr.nameseq);
345 exit:
346 	up(&tsock->sem);
347 	return res;
348 }
349 
350 /**
351  * get_name - get port ID of socket or peer socket
352  * @sock: socket structure
353  * @uaddr: area for returned socket address
354  * @uaddr_len: area for returned length of socket address
355  * @peer: 0 to obtain socket name, 1 to obtain peer socket name
356  *
357  * Returns 0 on success, errno otherwise
358  */
359 
360 static int get_name(struct socket *sock, struct sockaddr *uaddr,
361 		    int *uaddr_len, int peer)
362 {
363 	struct tipc_sock *tsock = tipc_sk(sock->sk);
364 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
365 	u32 res;
366 
367 	if (down_interruptible(&tsock->sem))
368 		return -ERESTARTSYS;
369 
370 	*uaddr_len = sizeof(*addr);
371 	addr->addrtype = TIPC_ADDR_ID;
372 	addr->family = AF_TIPC;
373 	addr->scope = 0;
374 	if (peer)
375 		res = tipc_peer(tsock->p->ref, &addr->addr.id);
376 	else
377 		res = tipc_ownidentity(tsock->p->ref, &addr->addr.id);
378 	addr->addr.name.domain = 0;
379 
380 	up(&tsock->sem);
381 	return res;
382 }
383 
384 /**
385  * poll - read and possibly block on pollmask
386  * @file: file structure associated with the socket
387  * @sock: socket for which to calculate the poll bits
388  * @wait: ???
389  *
390  * Returns the pollmask
391  */
392 
393 static unsigned int poll(struct file *file, struct socket *sock,
394 			 poll_table *wait)
395 {
396 	poll_wait(file, sock->sk->sk_sleep, wait);
397 	/* NEED LOCK HERE? */
398 	return pollmask(sock);
399 }
400 
401 /**
402  * dest_name_check - verify user is permitted to send to specified port name
403  * @dest: destination address
404  * @m: descriptor for message to be sent
405  *
406  * Prevents restricted configuration commands from being issued by
407  * unauthorized users.
408  *
409  * Returns 0 if permission is granted, otherwise errno
410  */
411 
412 static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m)
413 {
414 	struct tipc_cfg_msg_hdr hdr;
415 
416         if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES))
417                 return 0;
418         if (likely(dest->addr.name.name.type == TIPC_TOP_SRV))
419                 return 0;
420 
421         if (likely(dest->addr.name.name.type != TIPC_CFG_SRV))
422                 return -EACCES;
423 
424         if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr)))
425 		return -EFAULT;
426 	if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN)))
427 		return -EACCES;
428 
429 	return 0;
430 }
431 
432 /**
433  * send_msg - send message in connectionless manner
434  * @iocb: (unused)
435  * @sock: socket structure
436  * @m: message to send
437  * @total_len: length of message
438  *
439  * Message must have an destination specified explicitly.
440  * Used for SOCK_RDM and SOCK_DGRAM messages,
441  * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections.
442  * (Note: 'SYN+' is prohibited on SOCK_STREAM.)
443  *
444  * Returns the number of bytes sent on success, or errno otherwise
445  */
446 
447 static int send_msg(struct kiocb *iocb, struct socket *sock,
448 		    struct msghdr *m, size_t total_len)
449 {
450 	struct tipc_sock *tsock = tipc_sk(sock->sk);
451         struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
452 	struct sk_buff *buf;
453 	int needs_conn;
454 	int res = -EINVAL;
455 
456 	if (unlikely(!dest))
457 		return -EDESTADDRREQ;
458 	if (unlikely((m->msg_namelen < sizeof(*dest)) ||
459 		     (dest->family != AF_TIPC)))
460 		return -EINVAL;
461 
462 	needs_conn = (sock->state != SS_READY);
463 	if (unlikely(needs_conn)) {
464 		if (sock->state == SS_LISTENING)
465 			return -EPIPE;
466 		if (sock->state != SS_UNCONNECTED)
467 			return -EISCONN;
468 		if ((tsock->p->published) ||
469 		    ((sock->type == SOCK_STREAM) && (total_len != 0)))
470 			return -EOPNOTSUPP;
471 		if (dest->addrtype == TIPC_ADDR_NAME) {
472 			tsock->p->conn_type = dest->addr.name.name.type;
473 			tsock->p->conn_instance = dest->addr.name.name.instance;
474 		}
475 	}
476 
477 	if (down_interruptible(&tsock->sem))
478 		return -ERESTARTSYS;
479 
480 	if (needs_conn) {
481 
482 		/* Abort any pending connection attempts (very unlikely) */
483 
484 		while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
485 			tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
486 			atomic_dec(&tipc_queue_size);
487 		}
488 
489 		sock->state = SS_CONNECTING;
490 	}
491 
492         do {
493                 if (dest->addrtype == TIPC_ADDR_NAME) {
494                         if ((res = dest_name_check(dest, m)))
495                                 goto exit;
496                         res = tipc_send2name(tsock->p->ref,
497                                              &dest->addr.name.name,
498                                              dest->addr.name.domain,
499                                              m->msg_iovlen,
500                                              m->msg_iov);
501                 }
502                 else if (dest->addrtype == TIPC_ADDR_ID) {
503                         res = tipc_send2port(tsock->p->ref,
504                                              &dest->addr.id,
505                                              m->msg_iovlen,
506                                              m->msg_iov);
507                 }
508                 else if (dest->addrtype == TIPC_ADDR_MCAST) {
509 			if (needs_conn) {
510 				res = -EOPNOTSUPP;
511 				goto exit;
512 			}
513                         if ((res = dest_name_check(dest, m)))
514                                 goto exit;
515                         res = tipc_multicast(tsock->p->ref,
516                                              &dest->addr.nameseq,
517                                              0,
518                                              m->msg_iovlen,
519                                              m->msg_iov);
520                 }
521                 if (likely(res != -ELINKCONG)) {
522 exit:
523                         up(&tsock->sem);
524                         return res;
525                 }
526 		if (m->msg_flags & MSG_DONTWAIT) {
527 			res = -EWOULDBLOCK;
528 			goto exit;
529 		}
530                 if (wait_event_interruptible(*sock->sk->sk_sleep,
531                                              !tsock->p->congested)) {
532                     res = -ERESTARTSYS;
533                     goto exit;
534                 }
535         } while (1);
536 }
537 
538 /**
539  * send_packet - send a connection-oriented message
540  * @iocb: (unused)
541  * @sock: socket structure
542  * @m: message to send
543  * @total_len: length of message
544  *
545  * Used for SOCK_SEQPACKET messages and SOCK_STREAM data.
546  *
547  * Returns the number of bytes sent on success, or errno otherwise
548  */
549 
550 static int send_packet(struct kiocb *iocb, struct socket *sock,
551 		       struct msghdr *m, size_t total_len)
552 {
553 	struct tipc_sock *tsock = tipc_sk(sock->sk);
554         struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
555 	int res;
556 
557 	/* Handle implied connection establishment */
558 
559 	if (unlikely(dest))
560 		return send_msg(iocb, sock, m, total_len);
561 
562 	if (down_interruptible(&tsock->sem)) {
563 		return -ERESTARTSYS;
564         }
565 
566         do {
567 		if (unlikely(sock->state != SS_CONNECTED)) {
568 			if (sock->state == SS_DISCONNECTING)
569 				res = -EPIPE;
570 			else
571 				res = -ENOTCONN;
572 			goto exit;
573 		}
574 
575                 res = tipc_send(tsock->p->ref, m->msg_iovlen, m->msg_iov);
576                 if (likely(res != -ELINKCONG)) {
577 exit:
578                         up(&tsock->sem);
579                         return res;
580                 }
581 		if (m->msg_flags & MSG_DONTWAIT) {
582 			res = -EWOULDBLOCK;
583 			goto exit;
584 		}
585                 if (wait_event_interruptible(*sock->sk->sk_sleep,
586                                              !tsock->p->congested)) {
587                     res = -ERESTARTSYS;
588                     goto exit;
589                 }
590         } while (1);
591 }
592 
593 /**
594  * send_stream - send stream-oriented data
595  * @iocb: (unused)
596  * @sock: socket structure
597  * @m: data to send
598  * @total_len: total length of data to be sent
599  *
600  * Used for SOCK_STREAM data.
601  *
602  * Returns the number of bytes sent on success (or partial success),
603  * or errno if no data sent
604  */
605 
606 
607 static int send_stream(struct kiocb *iocb, struct socket *sock,
608 		       struct msghdr *m, size_t total_len)
609 {
610 	struct msghdr my_msg;
611 	struct iovec my_iov;
612 	struct iovec *curr_iov;
613 	int curr_iovlen;
614 	char __user *curr_start;
615 	int curr_left;
616 	int bytes_to_send;
617 	int bytes_sent;
618 	int res;
619 
620 	if (likely(total_len <= TIPC_MAX_USER_MSG_SIZE))
621 		return send_packet(iocb, sock, m, total_len);
622 
623 	/* Can only send large data streams if already connected */
624 
625         if (unlikely(sock->state != SS_CONNECTED)) {
626                 if (sock->state == SS_DISCONNECTING)
627                         return -EPIPE;
628                 else
629                         return -ENOTCONN;
630         }
631 
632 	/*
633 	 * Send each iovec entry using one or more messages
634 	 *
635 	 * Note: This algorithm is good for the most likely case
636 	 * (i.e. one large iovec entry), but could be improved to pass sets
637 	 * of small iovec entries into send_packet().
638 	 */
639 
640 	curr_iov = m->msg_iov;
641 	curr_iovlen = m->msg_iovlen;
642 	my_msg.msg_iov = &my_iov;
643 	my_msg.msg_iovlen = 1;
644 	bytes_sent = 0;
645 
646 	while (curr_iovlen--) {
647 		curr_start = curr_iov->iov_base;
648 		curr_left = curr_iov->iov_len;
649 
650 		while (curr_left) {
651 			bytes_to_send = (curr_left < TIPC_MAX_USER_MSG_SIZE)
652 				? curr_left : TIPC_MAX_USER_MSG_SIZE;
653 			my_iov.iov_base = curr_start;
654 			my_iov.iov_len = bytes_to_send;
655                         if ((res = send_packet(iocb, sock, &my_msg, 0)) < 0) {
656 				return bytes_sent ? bytes_sent : res;
657 			}
658 			curr_left -= bytes_to_send;
659 			curr_start += bytes_to_send;
660 			bytes_sent += bytes_to_send;
661 		}
662 
663 		curr_iov++;
664 	}
665 
666 	return bytes_sent;
667 }
668 
669 /**
670  * auto_connect - complete connection setup to a remote port
671  * @sock: socket structure
672  * @tsock: TIPC-specific socket structure
673  * @msg: peer's response message
674  *
675  * Returns 0 on success, errno otherwise
676  */
677 
678 static int auto_connect(struct socket *sock, struct tipc_sock *tsock,
679 			struct tipc_msg *msg)
680 {
681 	struct tipc_portid peer;
682 
683 	if (msg_errcode(msg)) {
684 		sock->state = SS_DISCONNECTING;
685 		return -ECONNREFUSED;
686 	}
687 
688 	peer.ref = msg_origport(msg);
689 	peer.node = msg_orignode(msg);
690 	tipc_connect2port(tsock->p->ref, &peer);
691 	tipc_set_portimportance(tsock->p->ref, msg_importance(msg));
692 	sock->state = SS_CONNECTED;
693 	return 0;
694 }
695 
696 /**
697  * set_orig_addr - capture sender's address for received message
698  * @m: descriptor for message info
699  * @msg: received message header
700  *
701  * Note: Address is not captured if not requested by receiver.
702  */
703 
704 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
705 {
706         struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
707 
708         if (addr) {
709 		addr->family = AF_TIPC;
710 		addr->addrtype = TIPC_ADDR_ID;
711 		addr->addr.id.ref = msg_origport(msg);
712 		addr->addr.id.node = msg_orignode(msg);
713 		addr->addr.name.domain = 0;   	/* could leave uninitialized */
714 		addr->scope = 0;   		/* could leave uninitialized */
715 		m->msg_namelen = sizeof(struct sockaddr_tipc);
716 	}
717 }
718 
719 /**
720  * anc_data_recv - optionally capture ancillary data for received message
721  * @m: descriptor for message info
722  * @msg: received message header
723  * @tport: TIPC port associated with message
724  *
725  * Note: Ancillary data is not captured if not requested by receiver.
726  *
727  * Returns 0 if successful, otherwise errno
728  */
729 
730 static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
731 				struct tipc_port *tport)
732 {
733 	u32 anc_data[3];
734 	u32 err;
735 	u32 dest_type;
736 	int has_name;
737 	int res;
738 
739 	if (likely(m->msg_controllen == 0))
740 		return 0;
741 
742 	/* Optionally capture errored message object(s) */
743 
744 	err = msg ? msg_errcode(msg) : 0;
745 	if (unlikely(err)) {
746 		anc_data[0] = err;
747 		anc_data[1] = msg_data_sz(msg);
748 		if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data)))
749 			return res;
750 		if (anc_data[1] &&
751 		    (res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
752 				    msg_data(msg))))
753 			return res;
754 	}
755 
756 	/* Optionally capture message destination object */
757 
758 	dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
759 	switch (dest_type) {
760 	case TIPC_NAMED_MSG:
761 		has_name = 1;
762 		anc_data[0] = msg_nametype(msg);
763 		anc_data[1] = msg_namelower(msg);
764 		anc_data[2] = msg_namelower(msg);
765 		break;
766 	case TIPC_MCAST_MSG:
767 		has_name = 1;
768 		anc_data[0] = msg_nametype(msg);
769 		anc_data[1] = msg_namelower(msg);
770 		anc_data[2] = msg_nameupper(msg);
771 		break;
772 	case TIPC_CONN_MSG:
773 		has_name = (tport->conn_type != 0);
774 		anc_data[0] = tport->conn_type;
775 		anc_data[1] = tport->conn_instance;
776 		anc_data[2] = tport->conn_instance;
777 		break;
778 	default:
779 		has_name = 0;
780 	}
781 	if (has_name &&
782 	    (res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data)))
783 		return res;
784 
785 	return 0;
786 }
787 
788 /**
789  * recv_msg - receive packet-oriented message
790  * @iocb: (unused)
791  * @m: descriptor for message info
792  * @buf_len: total size of user buffer area
793  * @flags: receive flags
794  *
795  * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
796  * If the complete message doesn't fit in user area, truncate it.
797  *
798  * Returns size of returned message data, errno otherwise
799  */
800 
801 static int recv_msg(struct kiocb *iocb, struct socket *sock,
802 		    struct msghdr *m, size_t buf_len, int flags)
803 {
804 	struct tipc_sock *tsock = tipc_sk(sock->sk);
805 	struct sk_buff *buf;
806 	struct tipc_msg *msg;
807 	unsigned int q_len;
808 	unsigned int sz;
809 	u32 err;
810 	int res;
811 
812 	/* Currently doesn't support receiving into multiple iovec entries */
813 
814 	if (m->msg_iovlen != 1)
815 		return -EOPNOTSUPP;
816 
817 	/* Catch invalid receive attempts */
818 
819 	if (unlikely(!buf_len))
820 		return -EINVAL;
821 
822 	if (sock->type == SOCK_SEQPACKET) {
823 		if (unlikely(sock->state == SS_UNCONNECTED))
824 			return -ENOTCONN;
825 		if (unlikely((sock->state == SS_DISCONNECTING) &&
826 			     (skb_queue_len(&sock->sk->sk_receive_queue) == 0)))
827 		       	return -ENOTCONN;
828 	}
829 
830 	/* Look for a message in receive queue; wait if necessary */
831 
832 	if (unlikely(down_interruptible(&tsock->sem)))
833 		return -ERESTARTSYS;
834 
835 restart:
836 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
837 		     (flags & MSG_DONTWAIT))) {
838 		res = -EWOULDBLOCK;
839 		goto exit;
840 	}
841 
842 	if ((res = wait_event_interruptible(
843 		*sock->sk->sk_sleep,
844 		((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
845 		 (sock->state == SS_DISCONNECTING))) )) {
846 		goto exit;
847 	}
848 
849 	/* Catch attempt to receive on an already terminated connection */
850 	/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
851 
852 	if (!q_len) {
853 		res = -ENOTCONN;
854 		goto exit;
855 	}
856 
857 	/* Get access to first message in receive queue */
858 
859 	buf = skb_peek(&sock->sk->sk_receive_queue);
860 	msg = buf_msg(buf);
861 	sz = msg_data_sz(msg);
862 	err = msg_errcode(msg);
863 
864 	/* Complete connection setup for an implied connect */
865 
866 	if (unlikely(sock->state == SS_CONNECTING)) {
867 		if ((res = auto_connect(sock, tsock, msg)))
868 			goto exit;
869 	}
870 
871 	/* Discard an empty non-errored message & try again */
872 
873 	if ((!sz) && (!err)) {
874 		advance_queue(tsock);
875 		goto restart;
876 	}
877 
878 	/* Capture sender's address (optional) */
879 
880 	set_orig_addr(m, msg);
881 
882 	/* Capture ancillary data (optional) */
883 
884 	if ((res = anc_data_recv(m, msg, tsock->p)))
885 		goto exit;
886 
887 	/* Capture message data (if valid) & compute return value (always) */
888 
889 	if (!err) {
890 		if (unlikely(buf_len < sz)) {
891 			sz = buf_len;
892 			m->msg_flags |= MSG_TRUNC;
893 		}
894 		if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg),
895 					  sz))) {
896 			res = -EFAULT;
897 			goto exit;
898 		}
899 		res = sz;
900 	} else {
901 		if ((sock->state == SS_READY) ||
902 		    ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
903 			res = 0;
904 		else
905 			res = -ECONNRESET;
906 	}
907 
908 	/* Consume received message (optional) */
909 
910 	if (likely(!(flags & MSG_PEEK))) {
911                 if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
912                         tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
913 		advance_queue(tsock);
914         }
915 exit:
916 	up(&tsock->sem);
917 	return res;
918 }
919 
920 /**
921  * recv_stream - receive stream-oriented data
922  * @iocb: (unused)
923  * @m: descriptor for message info
924  * @buf_len: total size of user buffer area
925  * @flags: receive flags
926  *
927  * Used for SOCK_STREAM messages only.  If not enough data is available
928  * will optionally wait for more; never truncates data.
929  *
930  * Returns size of returned message data, errno otherwise
931  */
932 
933 static int recv_stream(struct kiocb *iocb, struct socket *sock,
934 		       struct msghdr *m, size_t buf_len, int flags)
935 {
936 	struct tipc_sock *tsock = tipc_sk(sock->sk);
937 	struct sk_buff *buf;
938 	struct tipc_msg *msg;
939 	unsigned int q_len;
940 	unsigned int sz;
941 	int sz_to_copy;
942 	int sz_copied = 0;
943 	int needed;
944 	char *crs = m->msg_iov->iov_base;
945 	unsigned char *buf_crs;
946 	u32 err;
947 	int res;
948 
949 	/* Currently doesn't support receiving into multiple iovec entries */
950 
951 	if (m->msg_iovlen != 1)
952 		return -EOPNOTSUPP;
953 
954 	/* Catch invalid receive attempts */
955 
956 	if (unlikely(!buf_len))
957 		return -EINVAL;
958 
959 	if (unlikely(sock->state == SS_DISCONNECTING)) {
960 		if (skb_queue_len(&sock->sk->sk_receive_queue) == 0)
961 			return -ENOTCONN;
962 	} else if (unlikely(sock->state != SS_CONNECTED))
963 		return -ENOTCONN;
964 
965 	/* Look for a message in receive queue; wait if necessary */
966 
967 	if (unlikely(down_interruptible(&tsock->sem)))
968 		return -ERESTARTSYS;
969 
970 restart:
971 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
972 		     (flags & MSG_DONTWAIT))) {
973 		res = -EWOULDBLOCK;
974 		goto exit;
975 	}
976 
977 	if ((res = wait_event_interruptible(
978 		*sock->sk->sk_sleep,
979 		((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
980 		 (sock->state == SS_DISCONNECTING))) )) {
981 		goto exit;
982 	}
983 
984 	/* Catch attempt to receive on an already terminated connection */
985 	/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
986 
987 	if (!q_len) {
988 		res = -ENOTCONN;
989 		goto exit;
990 	}
991 
992 	/* Get access to first message in receive queue */
993 
994 	buf = skb_peek(&sock->sk->sk_receive_queue);
995 	msg = buf_msg(buf);
996 	sz = msg_data_sz(msg);
997 	err = msg_errcode(msg);
998 
999 	/* Discard an empty non-errored message & try again */
1000 
1001 	if ((!sz) && (!err)) {
1002 		advance_queue(tsock);
1003 		goto restart;
1004 	}
1005 
1006 	/* Optionally capture sender's address & ancillary data of first msg */
1007 
1008 	if (sz_copied == 0) {
1009 		set_orig_addr(m, msg);
1010 		if ((res = anc_data_recv(m, msg, tsock->p)))
1011 			goto exit;
1012 	}
1013 
1014 	/* Capture message data (if valid) & compute return value (always) */
1015 
1016 	if (!err) {
1017 		buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
1018 		sz = buf->tail - buf_crs;
1019 
1020 		needed = (buf_len - sz_copied);
1021 		sz_to_copy = (sz <= needed) ? sz : needed;
1022 		if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
1023 			res = -EFAULT;
1024 			goto exit;
1025 		}
1026 		sz_copied += sz_to_copy;
1027 
1028 		if (sz_to_copy < sz) {
1029 			if (!(flags & MSG_PEEK))
1030 				TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
1031 			goto exit;
1032 		}
1033 
1034 		crs += sz_to_copy;
1035 	} else {
1036 		if (sz_copied != 0)
1037 			goto exit; /* can't add error msg to valid data */
1038 
1039 		if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
1040 			res = 0;
1041 		else
1042 			res = -ECONNRESET;
1043 	}
1044 
1045 	/* Consume received message (optional) */
1046 
1047 	if (likely(!(flags & MSG_PEEK))) {
1048                 if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
1049                         tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
1050 		advance_queue(tsock);
1051         }
1052 
1053 	/* Loop around if more data is required */
1054 
1055 	if ((sz_copied < buf_len)    /* didn't get all requested data */
1056 	    && (flags & MSG_WAITALL) /* ... and need to wait for more */
1057 	    && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */
1058 	    && (!err)                /* ... and haven't reached a FIN */
1059 	    )
1060 		goto restart;
1061 
1062 exit:
1063 	up(&tsock->sem);
1064 	return sz_copied ? sz_copied : res;
1065 }
1066 
1067 /**
1068  * queue_overloaded - test if queue overload condition exists
1069  * @queue_size: current size of queue
1070  * @base: nominal maximum size of queue
1071  * @msg: message to be added to queue
1072  *
1073  * Returns 1 if queue is currently overloaded, 0 otherwise
1074  */
1075 
1076 static int queue_overloaded(u32 queue_size, u32 base, struct tipc_msg *msg)
1077 {
1078 	u32 threshold;
1079 	u32 imp = msg_importance(msg);
1080 
1081 	if (imp == TIPC_LOW_IMPORTANCE)
1082 		threshold = base;
1083 	else if (imp == TIPC_MEDIUM_IMPORTANCE)
1084 		threshold = base * 2;
1085 	else if (imp == TIPC_HIGH_IMPORTANCE)
1086 		threshold = base * 100;
1087 	else
1088 		return 0;
1089 
1090 	if (msg_connected(msg))
1091 		threshold *= 4;
1092 
1093 	return (queue_size > threshold);
1094 }
1095 
1096 /**
1097  * async_disconnect - wrapper function used to disconnect port
1098  * @portref: TIPC port reference (passed as pointer-sized value)
1099  */
1100 
1101 static void async_disconnect(unsigned long portref)
1102 {
1103 	tipc_disconnect((u32)portref);
1104 }
1105 
1106 /**
1107  * dispatch - handle arriving message
1108  * @tport: TIPC port that received message
1109  * @buf: message
1110  *
1111  * Called with port locked.  Must not take socket lock to avoid deadlock risk.
1112  *
1113  * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1114  */
1115 
1116 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
1117 {
1118 	struct tipc_msg *msg = buf_msg(buf);
1119 	struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
1120 	struct socket *sock;
1121 	u32 recv_q_len;
1122 
1123 	/* Reject message if socket is closing */
1124 
1125 	if (!tsock)
1126 		return TIPC_ERR_NO_PORT;
1127 
1128 	/* Reject message if it is wrong sort of message for socket */
1129 
1130 	/*
1131 	 * WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD?
1132 	 * "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY
1133 	 * BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC
1134 	 */
1135 	sock = tsock->sk.sk_socket;
1136 	if (sock->state == SS_READY) {
1137 		if (msg_connected(msg)) {
1138 			msg_dbg(msg, "dispatch filter 1\n");
1139 			return TIPC_ERR_NO_PORT;
1140 		}
1141 	} else {
1142 		if (msg_mcast(msg)) {
1143 			msg_dbg(msg, "dispatch filter 2\n");
1144 			return TIPC_ERR_NO_PORT;
1145 		}
1146 		if (sock->state == SS_CONNECTED) {
1147 			if (!msg_connected(msg)) {
1148 				msg_dbg(msg, "dispatch filter 3\n");
1149 				return TIPC_ERR_NO_PORT;
1150 			}
1151 		}
1152 		else if (sock->state == SS_CONNECTING) {
1153 			if (!msg_connected(msg) && (msg_errcode(msg) == 0)) {
1154 				msg_dbg(msg, "dispatch filter 4\n");
1155 				return TIPC_ERR_NO_PORT;
1156 			}
1157 		}
1158 		else if (sock->state == SS_LISTENING) {
1159 			if (msg_connected(msg) || msg_errcode(msg)) {
1160 				msg_dbg(msg, "dispatch filter 5\n");
1161 				return TIPC_ERR_NO_PORT;
1162 			}
1163 		}
1164 		else if (sock->state == SS_DISCONNECTING) {
1165 			msg_dbg(msg, "dispatch filter 6\n");
1166 			return TIPC_ERR_NO_PORT;
1167 		}
1168 		else /* (sock->state == SS_UNCONNECTED) */ {
1169 			if (msg_connected(msg) || msg_errcode(msg)) {
1170 				msg_dbg(msg, "dispatch filter 7\n");
1171 				return TIPC_ERR_NO_PORT;
1172 			}
1173 		}
1174 	}
1175 
1176 	/* Reject message if there isn't room to queue it */
1177 
1178 	if (unlikely((u32)atomic_read(&tipc_queue_size) >
1179 		     OVERLOAD_LIMIT_BASE)) {
1180 		if (queue_overloaded(atomic_read(&tipc_queue_size),
1181 				     OVERLOAD_LIMIT_BASE, msg))
1182 			return TIPC_ERR_OVERLOAD;
1183         }
1184 	recv_q_len = skb_queue_len(&tsock->sk.sk_receive_queue);
1185 	if (unlikely(recv_q_len > (OVERLOAD_LIMIT_BASE / 2))) {
1186 		if (queue_overloaded(recv_q_len,
1187 				     OVERLOAD_LIMIT_BASE / 2, msg))
1188 			return TIPC_ERR_OVERLOAD;
1189         }
1190 
1191 	/* Initiate connection termination for an incoming 'FIN' */
1192 
1193 	if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
1194 		sock->state = SS_DISCONNECTING;
1195 		/* Note: Use signal since port lock is already taken! */
1196 		tipc_k_signal((Handler)async_disconnect, tport->ref);
1197 	}
1198 
1199 	/* Enqueue message (finally!) */
1200 
1201 	msg_dbg(msg,"<DISP<: ");
1202 	TIPC_SKB_CB(buf)->handle = msg_data(msg);
1203 	atomic_inc(&tipc_queue_size);
1204 	skb_queue_tail(&sock->sk->sk_receive_queue, buf);
1205 
1206         wake_up_interruptible(sock->sk->sk_sleep);
1207 	return TIPC_OK;
1208 }
1209 
1210 /**
1211  * wakeupdispatch - wake up port after congestion
1212  * @tport: port to wakeup
1213  *
1214  * Called with port lock on.
1215  */
1216 
1217 static void wakeupdispatch(struct tipc_port *tport)
1218 {
1219 	struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
1220 
1221         wake_up_interruptible(tsock->sk.sk_sleep);
1222 }
1223 
1224 /**
1225  * connect - establish a connection to another TIPC port
1226  * @sock: socket structure
1227  * @dest: socket address for destination port
1228  * @destlen: size of socket address data structure
1229  * @flags: (unused)
1230  *
1231  * Returns 0 on success, errno otherwise
1232  */
1233 
1234 static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
1235 		   int flags)
1236 {
1237    struct tipc_sock *tsock = tipc_sk(sock->sk);
1238    struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
1239    struct msghdr m = {NULL,};
1240    struct sk_buff *buf;
1241    struct tipc_msg *msg;
1242    int res;
1243 
1244    /* For now, TIPC does not allow use of connect() with DGRAM or RDM types */
1245 
1246    if (sock->state == SS_READY)
1247 	   return -EOPNOTSUPP;
1248 
1249    /* Issue Posix-compliant error code if socket is in the wrong state */
1250 
1251    if (sock->state == SS_LISTENING)
1252 	   return -EOPNOTSUPP;
1253    if (sock->state == SS_CONNECTING)
1254 	   return -EALREADY;
1255    if (sock->state != SS_UNCONNECTED)
1256            return -EISCONN;
1257 
1258    /*
1259     * Reject connection attempt using multicast address
1260     *
1261     * Note: send_msg() validates the rest of the address fields,
1262     *       so there's no need to do it here
1263     */
1264 
1265    if (dst->addrtype == TIPC_ADDR_MCAST)
1266            return -EINVAL;
1267 
1268    /* Send a 'SYN-' to destination */
1269 
1270    m.msg_name = dest;
1271    m.msg_namelen = destlen;
1272    if ((res = send_msg(NULL, sock, &m, 0)) < 0) {
1273 	   sock->state = SS_DISCONNECTING;
1274 	   return res;
1275    }
1276 
1277    if (down_interruptible(&tsock->sem))
1278            return -ERESTARTSYS;
1279 
1280    /* Wait for destination's 'ACK' response */
1281 
1282    res = wait_event_interruptible_timeout(*sock->sk->sk_sleep,
1283                                           skb_queue_len(&sock->sk->sk_receive_queue),
1284 					  sock->sk->sk_rcvtimeo);
1285    buf = skb_peek(&sock->sk->sk_receive_queue);
1286    if (res > 0) {
1287 	   msg = buf_msg(buf);
1288            res = auto_connect(sock, tsock, msg);
1289            if (!res) {
1290 		   if (!msg_data_sz(msg))
1291 			   advance_queue(tsock);
1292 	   }
1293    } else {
1294 	   if (res == 0) {
1295 		   res = -ETIMEDOUT;
1296 	   } else
1297 	           { /* leave "res" unchanged */ }
1298 	   sock->state = SS_DISCONNECTING;
1299    }
1300 
1301    up(&tsock->sem);
1302    return res;
1303 }
1304 
1305 /**
1306  * listen - allow socket to listen for incoming connections
1307  * @sock: socket structure
1308  * @len: (unused)
1309  *
1310  * Returns 0 on success, errno otherwise
1311  */
1312 
1313 static int listen(struct socket *sock, int len)
1314 {
1315 	/* REQUIRES SOCKET LOCKING OF SOME SORT? */
1316 
1317 	if (sock->state == SS_READY)
1318 		return -EOPNOTSUPP;
1319 	if (sock->state != SS_UNCONNECTED)
1320 		return -EINVAL;
1321 	sock->state = SS_LISTENING;
1322         return 0;
1323 }
1324 
1325 /**
1326  * accept - wait for connection request
1327  * @sock: listening socket
1328  * @newsock: new socket that is to be connected
1329  * @flags: file-related flags associated with socket
1330  *
1331  * Returns 0 on success, errno otherwise
1332  */
1333 
1334 static int accept(struct socket *sock, struct socket *newsock, int flags)
1335 {
1336 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1337 	struct sk_buff *buf;
1338 	int res = -EFAULT;
1339 
1340 	if (sock->state == SS_READY)
1341 		return -EOPNOTSUPP;
1342 	if (sock->state != SS_LISTENING)
1343 		return -EINVAL;
1344 
1345 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
1346 		     (flags & O_NONBLOCK)))
1347 		return -EWOULDBLOCK;
1348 
1349 	if (down_interruptible(&tsock->sem))
1350 		return -ERESTARTSYS;
1351 
1352 	if (wait_event_interruptible(*sock->sk->sk_sleep,
1353 				     skb_queue_len(&sock->sk->sk_receive_queue))) {
1354 		res = -ERESTARTSYS;
1355 		goto exit;
1356 	}
1357 	buf = skb_peek(&sock->sk->sk_receive_queue);
1358 
1359 	res = tipc_create(newsock, 0);
1360 	if (!res) {
1361 		struct tipc_sock *new_tsock = tipc_sk(newsock->sk);
1362 		struct tipc_portid id;
1363 		struct tipc_msg *msg = buf_msg(buf);
1364 		u32 new_ref = new_tsock->p->ref;
1365 
1366 		id.ref = msg_origport(msg);
1367 		id.node = msg_orignode(msg);
1368 		tipc_connect2port(new_ref, &id);
1369 		newsock->state = SS_CONNECTED;
1370 
1371 		tipc_set_portimportance(new_ref, msg_importance(msg));
1372 		if (msg_named(msg)) {
1373 			new_tsock->p->conn_type = msg_nametype(msg);
1374 			new_tsock->p->conn_instance = msg_nameinst(msg);
1375 		}
1376 
1377                /*
1378 		 * Respond to 'SYN-' by discarding it & returning 'ACK'-.
1379 		 * Respond to 'SYN+' by queuing it on new socket.
1380 		 */
1381 
1382 		msg_dbg(msg,"<ACC<: ");
1383                 if (!msg_data_sz(msg)) {
1384                         struct msghdr m = {NULL,};
1385 
1386                         send_packet(NULL, newsock, &m, 0);
1387                         advance_queue(tsock);
1388                 } else {
1389 			sock_lock(tsock);
1390 			skb_dequeue(&sock->sk->sk_receive_queue);
1391 			sock_unlock(tsock);
1392 			skb_queue_head(&newsock->sk->sk_receive_queue, buf);
1393 		}
1394 	}
1395 exit:
1396 	up(&tsock->sem);
1397 	return res;
1398 }
1399 
1400 /**
1401  * shutdown - shutdown socket connection
1402  * @sock: socket structure
1403  * @how: direction to close (unused; always treated as read + write)
1404  *
1405  * Terminates connection (if necessary), then purges socket's receive queue.
1406  *
1407  * Returns 0 on success, errno otherwise
1408  */
1409 
1410 static int shutdown(struct socket *sock, int how)
1411 {
1412 	struct tipc_sock* tsock = tipc_sk(sock->sk);
1413 	struct sk_buff *buf;
1414 	int res;
1415 
1416 	/* Could return -EINVAL for an invalid "how", but why bother? */
1417 
1418 	if (down_interruptible(&tsock->sem))
1419 		return -ERESTARTSYS;
1420 
1421 	sock_lock(tsock);
1422 
1423 	switch (sock->state) {
1424 	case SS_CONNECTED:
1425 
1426 		/* Send 'FIN+' or 'FIN-' message to peer */
1427 
1428 		sock_unlock(tsock);
1429 restart:
1430 		if ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
1431 			atomic_dec(&tipc_queue_size);
1432 			if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) {
1433 				buf_discard(buf);
1434 				goto restart;
1435 			}
1436 			tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
1437 		}
1438 		else {
1439 			tipc_shutdown(tsock->p->ref);
1440 		}
1441 		sock_lock(tsock);
1442 
1443 		/* fall through */
1444 
1445 	case SS_DISCONNECTING:
1446 
1447 		/* Discard any unreceived messages */
1448 
1449 		while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
1450 			atomic_dec(&tipc_queue_size);
1451 			buf_discard(buf);
1452 		}
1453 		tsock->p->conn_unacked = 0;
1454 
1455 		/* fall through */
1456 
1457 	case SS_CONNECTING:
1458 		sock->state = SS_DISCONNECTING;
1459 		res = 0;
1460 		break;
1461 
1462 	default:
1463 		res = -ENOTCONN;
1464 	}
1465 
1466 	sock_unlock(tsock);
1467 
1468 	up(&tsock->sem);
1469 	return res;
1470 }
1471 
1472 /**
1473  * setsockopt - set socket option
1474  * @sock: socket structure
1475  * @lvl: option level
1476  * @opt: option identifier
1477  * @ov: pointer to new option value
1478  * @ol: length of option value
1479  *
1480  * For stream sockets only, accepts and ignores all IPPROTO_TCP options
1481  * (to ease compatibility).
1482  *
1483  * Returns 0 on success, errno otherwise
1484  */
1485 
1486 static int setsockopt(struct socket *sock,
1487 		      int lvl, int opt, char __user *ov, int ol)
1488 {
1489 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1490 	u32 value;
1491 	int res;
1492 
1493         if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1494                 return 0;
1495 	if (lvl != SOL_TIPC)
1496 		return -ENOPROTOOPT;
1497 	if (ol < sizeof(value))
1498 		return -EINVAL;
1499         if ((res = get_user(value, (u32 *)ov)))
1500 		return res;
1501 
1502 	if (down_interruptible(&tsock->sem))
1503 		return -ERESTARTSYS;
1504 
1505 	switch (opt) {
1506 	case TIPC_IMPORTANCE:
1507 		res = tipc_set_portimportance(tsock->p->ref, value);
1508 		break;
1509 	case TIPC_SRC_DROPPABLE:
1510 		if (sock->type != SOCK_STREAM)
1511 			res = tipc_set_portunreliable(tsock->p->ref, value);
1512 		else
1513 			res = -ENOPROTOOPT;
1514 		break;
1515 	case TIPC_DEST_DROPPABLE:
1516 		res = tipc_set_portunreturnable(tsock->p->ref, value);
1517 		break;
1518 	case TIPC_CONN_TIMEOUT:
1519 		sock->sk->sk_rcvtimeo = (value * HZ / 1000);
1520 		break;
1521 	default:
1522 		res = -EINVAL;
1523 	}
1524 
1525 	up(&tsock->sem);
1526 	return res;
1527 }
1528 
1529 /**
1530  * getsockopt - get socket option
1531  * @sock: socket structure
1532  * @lvl: option level
1533  * @opt: option identifier
1534  * @ov: receptacle for option value
1535  * @ol: receptacle for length of option value
1536  *
1537  * For stream sockets only, returns 0 length result for all IPPROTO_TCP options
1538  * (to ease compatibility).
1539  *
1540  * Returns 0 on success, errno otherwise
1541  */
1542 
1543 static int getsockopt(struct socket *sock,
1544 		      int lvl, int opt, char __user *ov, int *ol)
1545 {
1546 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1547         int len;
1548 	u32 value;
1549         int res;
1550 
1551         if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1552                 return put_user(0, ol);
1553 	if (lvl != SOL_TIPC)
1554 		return -ENOPROTOOPT;
1555         if ((res = get_user(len, ol)))
1556                 return res;
1557 
1558 	if (down_interruptible(&tsock->sem))
1559 		return -ERESTARTSYS;
1560 
1561 	switch (opt) {
1562 	case TIPC_IMPORTANCE:
1563 		res = tipc_portimportance(tsock->p->ref, &value);
1564 		break;
1565 	case TIPC_SRC_DROPPABLE:
1566 		res = tipc_portunreliable(tsock->p->ref, &value);
1567 		break;
1568 	case TIPC_DEST_DROPPABLE:
1569 		res = tipc_portunreturnable(tsock->p->ref, &value);
1570 		break;
1571 	case TIPC_CONN_TIMEOUT:
1572 		value = (sock->sk->sk_rcvtimeo * 1000) / HZ;
1573 		break;
1574 	default:
1575 		res = -EINVAL;
1576 	}
1577 
1578 	if (res) {
1579 		/* "get" failed */
1580 	}
1581 	else if (len < sizeof(value)) {
1582 		res = -EINVAL;
1583 	}
1584 	else if ((res = copy_to_user(ov, &value, sizeof(value)))) {
1585 		/* couldn't return value */
1586 	}
1587 	else {
1588 		res = put_user(sizeof(value), ol);
1589 	}
1590 
1591         up(&tsock->sem);
1592 	return res;
1593 }
1594 
1595 /**
1596  * Placeholders for non-implemented functionality
1597  *
1598  * Returns error code (POSIX-compliant where defined)
1599  */
1600 
1601 static int ioctl(struct socket *s, u32 cmd, unsigned long arg)
1602 {
1603         return -EINVAL;
1604 }
1605 
1606 static int no_mmap(struct file *file, struct socket *sock,
1607                    struct vm_area_struct *vma)
1608 {
1609         return -EINVAL;
1610 }
1611 static ssize_t no_sendpage(struct socket *sock, struct page *page,
1612                            int offset, size_t size, int flags)
1613 {
1614         return -EINVAL;
1615 }
1616 
1617 static int no_skpair(struct socket *s1, struct socket *s2)
1618 {
1619 	return -EOPNOTSUPP;
1620 }
1621 
1622 /**
1623  * Protocol switches for the various types of TIPC sockets
1624  */
1625 
1626 static struct proto_ops msg_ops = {
1627 	.owner 		= THIS_MODULE,
1628 	.family		= AF_TIPC,
1629 	.release	= release,
1630 	.bind		= bind,
1631 	.connect	= connect,
1632 	.socketpair	= no_skpair,
1633 	.accept		= accept,
1634 	.getname	= get_name,
1635 	.poll		= poll,
1636 	.ioctl		= ioctl,
1637 	.listen		= listen,
1638 	.shutdown	= shutdown,
1639 	.setsockopt	= setsockopt,
1640 	.getsockopt	= getsockopt,
1641 	.sendmsg	= send_msg,
1642 	.recvmsg	= recv_msg,
1643         .mmap		= no_mmap,
1644         .sendpage	= no_sendpage
1645 };
1646 
1647 static struct proto_ops packet_ops = {
1648 	.owner 		= THIS_MODULE,
1649 	.family		= AF_TIPC,
1650 	.release	= release,
1651 	.bind		= bind,
1652 	.connect	= connect,
1653 	.socketpair	= no_skpair,
1654 	.accept		= accept,
1655 	.getname	= get_name,
1656 	.poll		= poll,
1657 	.ioctl		= ioctl,
1658 	.listen		= listen,
1659 	.shutdown	= shutdown,
1660 	.setsockopt	= setsockopt,
1661 	.getsockopt	= getsockopt,
1662 	.sendmsg	= send_packet,
1663 	.recvmsg	= recv_msg,
1664         .mmap		= no_mmap,
1665         .sendpage	= no_sendpage
1666 };
1667 
1668 static struct proto_ops stream_ops = {
1669 	.owner 		= THIS_MODULE,
1670 	.family		= AF_TIPC,
1671 	.release	= release,
1672 	.bind		= bind,
1673 	.connect	= connect,
1674 	.socketpair	= no_skpair,
1675 	.accept		= accept,
1676 	.getname	= get_name,
1677 	.poll		= poll,
1678 	.ioctl		= ioctl,
1679 	.listen		= listen,
1680 	.shutdown	= shutdown,
1681 	.setsockopt	= setsockopt,
1682 	.getsockopt	= getsockopt,
1683 	.sendmsg	= send_stream,
1684 	.recvmsg	= recv_stream,
1685         .mmap		= no_mmap,
1686         .sendpage	= no_sendpage
1687 };
1688 
1689 static struct net_proto_family tipc_family_ops = {
1690 	.owner 		= THIS_MODULE,
1691 	.family		= AF_TIPC,
1692 	.create		= tipc_create
1693 };
1694 
1695 static struct proto tipc_proto = {
1696 	.name		= "TIPC",
1697 	.owner		= THIS_MODULE,
1698 	.obj_size	= sizeof(struct tipc_sock)
1699 };
1700 
1701 /**
1702  * tipc_socket_init - initialize TIPC socket interface
1703  *
1704  * Returns 0 on success, errno otherwise
1705  */
1706 int tipc_socket_init(void)
1707 {
1708 	int res;
1709 
1710         res = proto_register(&tipc_proto, 1);
1711 	if (res) {
1712 		err("Failed to register TIPC protocol type\n");
1713 		goto out;
1714 	}
1715 
1716 	res = sock_register(&tipc_family_ops);
1717 	if (res) {
1718 		err("Failed to register TIPC socket type\n");
1719 		proto_unregister(&tipc_proto);
1720 		goto out;
1721 	}
1722 
1723 	sockets_enabled = 1;
1724  out:
1725 	return res;
1726 }
1727 
1728 /**
1729  * tipc_socket_stop - stop TIPC socket interface
1730  */
1731 void tipc_socket_stop(void)
1732 {
1733 	if (!sockets_enabled)
1734 		return;
1735 
1736 	sockets_enabled = 0;
1737 	sock_unregister(tipc_family_ops.family);
1738 	proto_unregister(&tipc_proto);
1739 }
1740 
1741