xref: /openbmc/linux/net/tipc/socket.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * net/tipc/socket.c: TIPC socket API
3  *
4  * Copyright (c) 2001-2006, Ericsson AB
5  * Copyright (c) 2004-2006, 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 	if (unlikely(m->msg_name))
633 		return -EISCONN;
634 
635 	/*
636 	 * Send each iovec entry using one or more messages
637 	 *
638 	 * Note: This algorithm is good for the most likely case
639 	 * (i.e. one large iovec entry), but could be improved to pass sets
640 	 * of small iovec entries into send_packet().
641 	 */
642 
643 	curr_iov = m->msg_iov;
644 	curr_iovlen = m->msg_iovlen;
645 	my_msg.msg_iov = &my_iov;
646 	my_msg.msg_iovlen = 1;
647 	my_msg.msg_flags = m->msg_flags;
648 	my_msg.msg_name = NULL;
649 	bytes_sent = 0;
650 
651 	while (curr_iovlen--) {
652 		curr_start = curr_iov->iov_base;
653 		curr_left = curr_iov->iov_len;
654 
655 		while (curr_left) {
656 			bytes_to_send = (curr_left < TIPC_MAX_USER_MSG_SIZE)
657 				? curr_left : TIPC_MAX_USER_MSG_SIZE;
658 			my_iov.iov_base = curr_start;
659 			my_iov.iov_len = bytes_to_send;
660 			if ((res = send_packet(iocb, sock, &my_msg, 0)) < 0) {
661 				return bytes_sent ? bytes_sent : res;
662 			}
663 			curr_left -= bytes_to_send;
664 			curr_start += bytes_to_send;
665 			bytes_sent += bytes_to_send;
666 		}
667 
668 		curr_iov++;
669 	}
670 
671 	return bytes_sent;
672 }
673 
674 /**
675  * auto_connect - complete connection setup to a remote port
676  * @sock: socket structure
677  * @tsock: TIPC-specific socket structure
678  * @msg: peer's response message
679  *
680  * Returns 0 on success, errno otherwise
681  */
682 
683 static int auto_connect(struct socket *sock, struct tipc_sock *tsock,
684 			struct tipc_msg *msg)
685 {
686 	struct tipc_portid peer;
687 
688 	if (msg_errcode(msg)) {
689 		sock->state = SS_DISCONNECTING;
690 		return -ECONNREFUSED;
691 	}
692 
693 	peer.ref = msg_origport(msg);
694 	peer.node = msg_orignode(msg);
695 	tipc_connect2port(tsock->p->ref, &peer);
696 	tipc_set_portimportance(tsock->p->ref, msg_importance(msg));
697 	sock->state = SS_CONNECTED;
698 	return 0;
699 }
700 
701 /**
702  * set_orig_addr - capture sender's address for received message
703  * @m: descriptor for message info
704  * @msg: received message header
705  *
706  * Note: Address is not captured if not requested by receiver.
707  */
708 
709 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
710 {
711 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
712 
713 	if (addr) {
714 		addr->family = AF_TIPC;
715 		addr->addrtype = TIPC_ADDR_ID;
716 		addr->addr.id.ref = msg_origport(msg);
717 		addr->addr.id.node = msg_orignode(msg);
718 		addr->addr.name.domain = 0;   	/* could leave uninitialized */
719 		addr->scope = 0;   		/* could leave uninitialized */
720 		m->msg_namelen = sizeof(struct sockaddr_tipc);
721 	}
722 }
723 
724 /**
725  * anc_data_recv - optionally capture ancillary data for received message
726  * @m: descriptor for message info
727  * @msg: received message header
728  * @tport: TIPC port associated with message
729  *
730  * Note: Ancillary data is not captured if not requested by receiver.
731  *
732  * Returns 0 if successful, otherwise errno
733  */
734 
735 static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
736 				struct tipc_port *tport)
737 {
738 	u32 anc_data[3];
739 	u32 err;
740 	u32 dest_type;
741 	int has_name;
742 	int res;
743 
744 	if (likely(m->msg_controllen == 0))
745 		return 0;
746 
747 	/* Optionally capture errored message object(s) */
748 
749 	err = msg ? msg_errcode(msg) : 0;
750 	if (unlikely(err)) {
751 		anc_data[0] = err;
752 		anc_data[1] = msg_data_sz(msg);
753 		if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data)))
754 			return res;
755 		if (anc_data[1] &&
756 		    (res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
757 				    msg_data(msg))))
758 			return res;
759 	}
760 
761 	/* Optionally capture message destination object */
762 
763 	dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
764 	switch (dest_type) {
765 	case TIPC_NAMED_MSG:
766 		has_name = 1;
767 		anc_data[0] = msg_nametype(msg);
768 		anc_data[1] = msg_namelower(msg);
769 		anc_data[2] = msg_namelower(msg);
770 		break;
771 	case TIPC_MCAST_MSG:
772 		has_name = 1;
773 		anc_data[0] = msg_nametype(msg);
774 		anc_data[1] = msg_namelower(msg);
775 		anc_data[2] = msg_nameupper(msg);
776 		break;
777 	case TIPC_CONN_MSG:
778 		has_name = (tport->conn_type != 0);
779 		anc_data[0] = tport->conn_type;
780 		anc_data[1] = tport->conn_instance;
781 		anc_data[2] = tport->conn_instance;
782 		break;
783 	default:
784 		has_name = 0;
785 	}
786 	if (has_name &&
787 	    (res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data)))
788 		return res;
789 
790 	return 0;
791 }
792 
793 /**
794  * recv_msg - receive packet-oriented message
795  * @iocb: (unused)
796  * @m: descriptor for message info
797  * @buf_len: total size of user buffer area
798  * @flags: receive flags
799  *
800  * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
801  * If the complete message doesn't fit in user area, truncate it.
802  *
803  * Returns size of returned message data, errno otherwise
804  */
805 
806 static int recv_msg(struct kiocb *iocb, struct socket *sock,
807 		    struct msghdr *m, size_t buf_len, int flags)
808 {
809 	struct tipc_sock *tsock = tipc_sk(sock->sk);
810 	struct sk_buff *buf;
811 	struct tipc_msg *msg;
812 	unsigned int q_len;
813 	unsigned int sz;
814 	u32 err;
815 	int res;
816 
817 	/* Currently doesn't support receiving into multiple iovec entries */
818 
819 	if (m->msg_iovlen != 1)
820 		return -EOPNOTSUPP;
821 
822 	/* Catch invalid receive attempts */
823 
824 	if (unlikely(!buf_len))
825 		return -EINVAL;
826 
827 	if (sock->type == SOCK_SEQPACKET) {
828 		if (unlikely(sock->state == SS_UNCONNECTED))
829 			return -ENOTCONN;
830 		if (unlikely((sock->state == SS_DISCONNECTING) &&
831 			     (skb_queue_len(&sock->sk->sk_receive_queue) == 0)))
832 			return -ENOTCONN;
833 	}
834 
835 	/* Look for a message in receive queue; wait if necessary */
836 
837 	if (unlikely(down_interruptible(&tsock->sem)))
838 		return -ERESTARTSYS;
839 
840 restart:
841 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
842 		     (flags & MSG_DONTWAIT))) {
843 		res = -EWOULDBLOCK;
844 		goto exit;
845 	}
846 
847 	if ((res = wait_event_interruptible(
848 		*sock->sk->sk_sleep,
849 		((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
850 		 (sock->state == SS_DISCONNECTING))) )) {
851 		goto exit;
852 	}
853 
854 	/* Catch attempt to receive on an already terminated connection */
855 	/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
856 
857 	if (!q_len) {
858 		res = -ENOTCONN;
859 		goto exit;
860 	}
861 
862 	/* Get access to first message in receive queue */
863 
864 	buf = skb_peek(&sock->sk->sk_receive_queue);
865 	msg = buf_msg(buf);
866 	sz = msg_data_sz(msg);
867 	err = msg_errcode(msg);
868 
869 	/* Complete connection setup for an implied connect */
870 
871 	if (unlikely(sock->state == SS_CONNECTING)) {
872 		if ((res = auto_connect(sock, tsock, msg)))
873 			goto exit;
874 	}
875 
876 	/* Discard an empty non-errored message & try again */
877 
878 	if ((!sz) && (!err)) {
879 		advance_queue(tsock);
880 		goto restart;
881 	}
882 
883 	/* Capture sender's address (optional) */
884 
885 	set_orig_addr(m, msg);
886 
887 	/* Capture ancillary data (optional) */
888 
889 	if ((res = anc_data_recv(m, msg, tsock->p)))
890 		goto exit;
891 
892 	/* Capture message data (if valid) & compute return value (always) */
893 
894 	if (!err) {
895 		if (unlikely(buf_len < sz)) {
896 			sz = buf_len;
897 			m->msg_flags |= MSG_TRUNC;
898 		}
899 		if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg),
900 					  sz))) {
901 			res = -EFAULT;
902 			goto exit;
903 		}
904 		res = sz;
905 	} else {
906 		if ((sock->state == SS_READY) ||
907 		    ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
908 			res = 0;
909 		else
910 			res = -ECONNRESET;
911 	}
912 
913 	/* Consume received message (optional) */
914 
915 	if (likely(!(flags & MSG_PEEK))) {
916 		if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
917 			tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
918 		advance_queue(tsock);
919 	}
920 exit:
921 	up(&tsock->sem);
922 	return res;
923 }
924 
925 /**
926  * recv_stream - receive stream-oriented data
927  * @iocb: (unused)
928  * @m: descriptor for message info
929  * @buf_len: total size of user buffer area
930  * @flags: receive flags
931  *
932  * Used for SOCK_STREAM messages only.  If not enough data is available
933  * will optionally wait for more; never truncates data.
934  *
935  * Returns size of returned message data, errno otherwise
936  */
937 
938 static int recv_stream(struct kiocb *iocb, struct socket *sock,
939 		       struct msghdr *m, size_t buf_len, int flags)
940 {
941 	struct tipc_sock *tsock = tipc_sk(sock->sk);
942 	struct sk_buff *buf;
943 	struct tipc_msg *msg;
944 	unsigned int q_len;
945 	unsigned int sz;
946 	int sz_to_copy;
947 	int sz_copied = 0;
948 	int needed;
949 	char __user *crs = m->msg_iov->iov_base;
950 	unsigned char *buf_crs;
951 	u32 err;
952 	int res;
953 
954 	/* Currently doesn't support receiving into multiple iovec entries */
955 
956 	if (m->msg_iovlen != 1)
957 		return -EOPNOTSUPP;
958 
959 	/* Catch invalid receive attempts */
960 
961 	if (unlikely(!buf_len))
962 		return -EINVAL;
963 
964 	if (unlikely(sock->state == SS_DISCONNECTING)) {
965 		if (skb_queue_len(&sock->sk->sk_receive_queue) == 0)
966 			return -ENOTCONN;
967 	} else if (unlikely(sock->state != SS_CONNECTED))
968 		return -ENOTCONN;
969 
970 	/* Look for a message in receive queue; wait if necessary */
971 
972 	if (unlikely(down_interruptible(&tsock->sem)))
973 		return -ERESTARTSYS;
974 
975 restart:
976 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
977 		     (flags & MSG_DONTWAIT))) {
978 		res = -EWOULDBLOCK;
979 		goto exit;
980 	}
981 
982 	if ((res = wait_event_interruptible(
983 		*sock->sk->sk_sleep,
984 		((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
985 		 (sock->state == SS_DISCONNECTING))) )) {
986 		goto exit;
987 	}
988 
989 	/* Catch attempt to receive on an already terminated connection */
990 	/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
991 
992 	if (!q_len) {
993 		res = -ENOTCONN;
994 		goto exit;
995 	}
996 
997 	/* Get access to first message in receive queue */
998 
999 	buf = skb_peek(&sock->sk->sk_receive_queue);
1000 	msg = buf_msg(buf);
1001 	sz = msg_data_sz(msg);
1002 	err = msg_errcode(msg);
1003 
1004 	/* Discard an empty non-errored message & try again */
1005 
1006 	if ((!sz) && (!err)) {
1007 		advance_queue(tsock);
1008 		goto restart;
1009 	}
1010 
1011 	/* Optionally capture sender's address & ancillary data of first msg */
1012 
1013 	if (sz_copied == 0) {
1014 		set_orig_addr(m, msg);
1015 		if ((res = anc_data_recv(m, msg, tsock->p)))
1016 			goto exit;
1017 	}
1018 
1019 	/* Capture message data (if valid) & compute return value (always) */
1020 
1021 	if (!err) {
1022 		buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
1023 		sz = skb_tail_pointer(buf) - buf_crs;
1024 
1025 		needed = (buf_len - sz_copied);
1026 		sz_to_copy = (sz <= needed) ? sz : needed;
1027 		if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
1028 			res = -EFAULT;
1029 			goto exit;
1030 		}
1031 		sz_copied += sz_to_copy;
1032 
1033 		if (sz_to_copy < sz) {
1034 			if (!(flags & MSG_PEEK))
1035 				TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
1036 			goto exit;
1037 		}
1038 
1039 		crs += sz_to_copy;
1040 	} else {
1041 		if (sz_copied != 0)
1042 			goto exit; /* can't add error msg to valid data */
1043 
1044 		if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
1045 			res = 0;
1046 		else
1047 			res = -ECONNRESET;
1048 	}
1049 
1050 	/* Consume received message (optional) */
1051 
1052 	if (likely(!(flags & MSG_PEEK))) {
1053 		if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
1054 			tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
1055 		advance_queue(tsock);
1056 	}
1057 
1058 	/* Loop around if more data is required */
1059 
1060 	if ((sz_copied < buf_len)    /* didn't get all requested data */
1061 	    && (flags & MSG_WAITALL) /* ... and need to wait for more */
1062 	    && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */
1063 	    && (!err)                /* ... and haven't reached a FIN */
1064 	    )
1065 		goto restart;
1066 
1067 exit:
1068 	up(&tsock->sem);
1069 	return sz_copied ? sz_copied : res;
1070 }
1071 
1072 /**
1073  * queue_overloaded - test if queue overload condition exists
1074  * @queue_size: current size of queue
1075  * @base: nominal maximum size of queue
1076  * @msg: message to be added to queue
1077  *
1078  * Returns 1 if queue is currently overloaded, 0 otherwise
1079  */
1080 
1081 static int queue_overloaded(u32 queue_size, u32 base, struct tipc_msg *msg)
1082 {
1083 	u32 threshold;
1084 	u32 imp = msg_importance(msg);
1085 
1086 	if (imp == TIPC_LOW_IMPORTANCE)
1087 		threshold = base;
1088 	else if (imp == TIPC_MEDIUM_IMPORTANCE)
1089 		threshold = base * 2;
1090 	else if (imp == TIPC_HIGH_IMPORTANCE)
1091 		threshold = base * 100;
1092 	else
1093 		return 0;
1094 
1095 	if (msg_connected(msg))
1096 		threshold *= 4;
1097 
1098 	return (queue_size > threshold);
1099 }
1100 
1101 /**
1102  * async_disconnect - wrapper function used to disconnect port
1103  * @portref: TIPC port reference (passed as pointer-sized value)
1104  */
1105 
1106 static void async_disconnect(unsigned long portref)
1107 {
1108 	tipc_disconnect((u32)portref);
1109 }
1110 
1111 /**
1112  * dispatch - handle arriving message
1113  * @tport: TIPC port that received message
1114  * @buf: message
1115  *
1116  * Called with port locked.  Must not take socket lock to avoid deadlock risk.
1117  *
1118  * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1119  */
1120 
1121 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
1122 {
1123 	struct tipc_msg *msg = buf_msg(buf);
1124 	struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
1125 	struct socket *sock;
1126 	u32 recv_q_len;
1127 
1128 	/* Reject message if socket is closing */
1129 
1130 	if (!tsock)
1131 		return TIPC_ERR_NO_PORT;
1132 
1133 	/* Reject message if it is wrong sort of message for socket */
1134 
1135 	/*
1136 	 * WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD?
1137 	 * "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY
1138 	 * BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC
1139 	 */
1140 	sock = tsock->sk.sk_socket;
1141 	if (sock->state == SS_READY) {
1142 		if (msg_connected(msg)) {
1143 			msg_dbg(msg, "dispatch filter 1\n");
1144 			return TIPC_ERR_NO_PORT;
1145 		}
1146 	} else {
1147 		if (msg_mcast(msg)) {
1148 			msg_dbg(msg, "dispatch filter 2\n");
1149 			return TIPC_ERR_NO_PORT;
1150 		}
1151 		if (sock->state == SS_CONNECTED) {
1152 			if (!msg_connected(msg)) {
1153 				msg_dbg(msg, "dispatch filter 3\n");
1154 				return TIPC_ERR_NO_PORT;
1155 			}
1156 		}
1157 		else if (sock->state == SS_CONNECTING) {
1158 			if (!msg_connected(msg) && (msg_errcode(msg) == 0)) {
1159 				msg_dbg(msg, "dispatch filter 4\n");
1160 				return TIPC_ERR_NO_PORT;
1161 			}
1162 		}
1163 		else if (sock->state == SS_LISTENING) {
1164 			if (msg_connected(msg) || msg_errcode(msg)) {
1165 				msg_dbg(msg, "dispatch filter 5\n");
1166 				return TIPC_ERR_NO_PORT;
1167 			}
1168 		}
1169 		else if (sock->state == SS_DISCONNECTING) {
1170 			msg_dbg(msg, "dispatch filter 6\n");
1171 			return TIPC_ERR_NO_PORT;
1172 		}
1173 		else /* (sock->state == SS_UNCONNECTED) */ {
1174 			if (msg_connected(msg) || msg_errcode(msg)) {
1175 				msg_dbg(msg, "dispatch filter 7\n");
1176 				return TIPC_ERR_NO_PORT;
1177 			}
1178 		}
1179 	}
1180 
1181 	/* Reject message if there isn't room to queue it */
1182 
1183 	if (unlikely((u32)atomic_read(&tipc_queue_size) >
1184 		     OVERLOAD_LIMIT_BASE)) {
1185 		if (queue_overloaded(atomic_read(&tipc_queue_size),
1186 				     OVERLOAD_LIMIT_BASE, msg))
1187 			return TIPC_ERR_OVERLOAD;
1188 	}
1189 	recv_q_len = skb_queue_len(&tsock->sk.sk_receive_queue);
1190 	if (unlikely(recv_q_len > (OVERLOAD_LIMIT_BASE / 2))) {
1191 		if (queue_overloaded(recv_q_len,
1192 				     OVERLOAD_LIMIT_BASE / 2, msg))
1193 			return TIPC_ERR_OVERLOAD;
1194 	}
1195 
1196 	/* Initiate connection termination for an incoming 'FIN' */
1197 
1198 	if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
1199 		sock->state = SS_DISCONNECTING;
1200 		/* Note: Use signal since port lock is already taken! */
1201 		tipc_k_signal((Handler)async_disconnect, tport->ref);
1202 	}
1203 
1204 	/* Enqueue message (finally!) */
1205 
1206 	msg_dbg(msg,"<DISP<: ");
1207 	TIPC_SKB_CB(buf)->handle = msg_data(msg);
1208 	atomic_inc(&tipc_queue_size);
1209 	skb_queue_tail(&sock->sk->sk_receive_queue, buf);
1210 
1211 	if (waitqueue_active(sock->sk->sk_sleep))
1212 		wake_up_interruptible(sock->sk->sk_sleep);
1213 	return TIPC_OK;
1214 }
1215 
1216 /**
1217  * wakeupdispatch - wake up port after congestion
1218  * @tport: port to wakeup
1219  *
1220  * Called with port lock on.
1221  */
1222 
1223 static void wakeupdispatch(struct tipc_port *tport)
1224 {
1225 	struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
1226 
1227 	if (waitqueue_active(tsock->sk.sk_sleep))
1228 		wake_up_interruptible(tsock->sk.sk_sleep);
1229 }
1230 
1231 /**
1232  * connect - establish a connection to another TIPC port
1233  * @sock: socket structure
1234  * @dest: socket address for destination port
1235  * @destlen: size of socket address data structure
1236  * @flags: (unused)
1237  *
1238  * Returns 0 on success, errno otherwise
1239  */
1240 
1241 static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
1242 		   int flags)
1243 {
1244    struct tipc_sock *tsock = tipc_sk(sock->sk);
1245    struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
1246    struct msghdr m = {NULL,};
1247    struct sk_buff *buf;
1248    struct tipc_msg *msg;
1249    int res;
1250 
1251    /* For now, TIPC does not allow use of connect() with DGRAM or RDM types */
1252 
1253    if (sock->state == SS_READY)
1254 	   return -EOPNOTSUPP;
1255 
1256    /* Issue Posix-compliant error code if socket is in the wrong state */
1257 
1258    if (sock->state == SS_LISTENING)
1259 	   return -EOPNOTSUPP;
1260    if (sock->state == SS_CONNECTING)
1261 	   return -EALREADY;
1262    if (sock->state != SS_UNCONNECTED)
1263 	   return -EISCONN;
1264 
1265    /*
1266     * Reject connection attempt using multicast address
1267     *
1268     * Note: send_msg() validates the rest of the address fields,
1269     *       so there's no need to do it here
1270     */
1271 
1272    if (dst->addrtype == TIPC_ADDR_MCAST)
1273 	   return -EINVAL;
1274 
1275    /* Send a 'SYN-' to destination */
1276 
1277    m.msg_name = dest;
1278    m.msg_namelen = destlen;
1279    if ((res = send_msg(NULL, sock, &m, 0)) < 0) {
1280 	   sock->state = SS_DISCONNECTING;
1281 	   return res;
1282    }
1283 
1284    if (down_interruptible(&tsock->sem))
1285 	   return -ERESTARTSYS;
1286 
1287    /* Wait for destination's 'ACK' response */
1288 
1289    res = wait_event_interruptible_timeout(*sock->sk->sk_sleep,
1290 					  skb_queue_len(&sock->sk->sk_receive_queue),
1291 					  sock->sk->sk_rcvtimeo);
1292    buf = skb_peek(&sock->sk->sk_receive_queue);
1293    if (res > 0) {
1294 	   msg = buf_msg(buf);
1295 	   res = auto_connect(sock, tsock, msg);
1296 	   if (!res) {
1297 		   if (!msg_data_sz(msg))
1298 			   advance_queue(tsock);
1299 	   }
1300    } else {
1301 	   if (res == 0) {
1302 		   res = -ETIMEDOUT;
1303 	   } else
1304 		   { /* leave "res" unchanged */ }
1305 	   sock->state = SS_DISCONNECTING;
1306    }
1307 
1308    up(&tsock->sem);
1309    return res;
1310 }
1311 
1312 /**
1313  * listen - allow socket to listen for incoming connections
1314  * @sock: socket structure
1315  * @len: (unused)
1316  *
1317  * Returns 0 on success, errno otherwise
1318  */
1319 
1320 static int listen(struct socket *sock, int len)
1321 {
1322 	/* REQUIRES SOCKET LOCKING OF SOME SORT? */
1323 
1324 	if (sock->state == SS_READY)
1325 		return -EOPNOTSUPP;
1326 	if (sock->state != SS_UNCONNECTED)
1327 		return -EINVAL;
1328 	sock->state = SS_LISTENING;
1329 	return 0;
1330 }
1331 
1332 /**
1333  * accept - wait for connection request
1334  * @sock: listening socket
1335  * @newsock: new socket that is to be connected
1336  * @flags: file-related flags associated with socket
1337  *
1338  * Returns 0 on success, errno otherwise
1339  */
1340 
1341 static int accept(struct socket *sock, struct socket *newsock, int flags)
1342 {
1343 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1344 	struct sk_buff *buf;
1345 	int res = -EFAULT;
1346 
1347 	if (sock->state == SS_READY)
1348 		return -EOPNOTSUPP;
1349 	if (sock->state != SS_LISTENING)
1350 		return -EINVAL;
1351 
1352 	if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
1353 		     (flags & O_NONBLOCK)))
1354 		return -EWOULDBLOCK;
1355 
1356 	if (down_interruptible(&tsock->sem))
1357 		return -ERESTARTSYS;
1358 
1359 	if (wait_event_interruptible(*sock->sk->sk_sleep,
1360 				     skb_queue_len(&sock->sk->sk_receive_queue))) {
1361 		res = -ERESTARTSYS;
1362 		goto exit;
1363 	}
1364 	buf = skb_peek(&sock->sk->sk_receive_queue);
1365 
1366 	res = tipc_create(newsock, 0);
1367 	if (!res) {
1368 		struct tipc_sock *new_tsock = tipc_sk(newsock->sk);
1369 		struct tipc_portid id;
1370 		struct tipc_msg *msg = buf_msg(buf);
1371 		u32 new_ref = new_tsock->p->ref;
1372 
1373 		id.ref = msg_origport(msg);
1374 		id.node = msg_orignode(msg);
1375 		tipc_connect2port(new_ref, &id);
1376 		newsock->state = SS_CONNECTED;
1377 
1378 		tipc_set_portimportance(new_ref, msg_importance(msg));
1379 		if (msg_named(msg)) {
1380 			new_tsock->p->conn_type = msg_nametype(msg);
1381 			new_tsock->p->conn_instance = msg_nameinst(msg);
1382 		}
1383 
1384 	       /*
1385 		 * Respond to 'SYN-' by discarding it & returning 'ACK'-.
1386 		 * Respond to 'SYN+' by queuing it on new socket.
1387 		 */
1388 
1389 		msg_dbg(msg,"<ACC<: ");
1390 		if (!msg_data_sz(msg)) {
1391 			struct msghdr m = {NULL,};
1392 
1393 			send_packet(NULL, newsock, &m, 0);
1394 			advance_queue(tsock);
1395 		} else {
1396 			sock_lock(tsock);
1397 			skb_dequeue(&sock->sk->sk_receive_queue);
1398 			sock_unlock(tsock);
1399 			skb_queue_head(&newsock->sk->sk_receive_queue, buf);
1400 		}
1401 	}
1402 exit:
1403 	up(&tsock->sem);
1404 	return res;
1405 }
1406 
1407 /**
1408  * shutdown - shutdown socket connection
1409  * @sock: socket structure
1410  * @how: direction to close (unused; always treated as read + write)
1411  *
1412  * Terminates connection (if necessary), then purges socket's receive queue.
1413  *
1414  * Returns 0 on success, errno otherwise
1415  */
1416 
1417 static int shutdown(struct socket *sock, int how)
1418 {
1419 	struct tipc_sock* tsock = tipc_sk(sock->sk);
1420 	struct sk_buff *buf;
1421 	int res;
1422 
1423 	/* Could return -EINVAL for an invalid "how", but why bother? */
1424 
1425 	if (down_interruptible(&tsock->sem))
1426 		return -ERESTARTSYS;
1427 
1428 	sock_lock(tsock);
1429 
1430 	switch (sock->state) {
1431 	case SS_CONNECTED:
1432 
1433 		/* Send 'FIN+' or 'FIN-' message to peer */
1434 
1435 		sock_unlock(tsock);
1436 restart:
1437 		if ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
1438 			atomic_dec(&tipc_queue_size);
1439 			if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) {
1440 				buf_discard(buf);
1441 				goto restart;
1442 			}
1443 			tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
1444 		}
1445 		else {
1446 			tipc_shutdown(tsock->p->ref);
1447 		}
1448 		sock_lock(tsock);
1449 
1450 		/* fall through */
1451 
1452 	case SS_DISCONNECTING:
1453 
1454 		/* Discard any unreceived messages */
1455 
1456 		while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
1457 			atomic_dec(&tipc_queue_size);
1458 			buf_discard(buf);
1459 		}
1460 		tsock->p->conn_unacked = 0;
1461 
1462 		/* fall through */
1463 
1464 	case SS_CONNECTING:
1465 		sock->state = SS_DISCONNECTING;
1466 		res = 0;
1467 		break;
1468 
1469 	default:
1470 		res = -ENOTCONN;
1471 	}
1472 
1473 	sock_unlock(tsock);
1474 
1475 	up(&tsock->sem);
1476 	return res;
1477 }
1478 
1479 /**
1480  * setsockopt - set socket option
1481  * @sock: socket structure
1482  * @lvl: option level
1483  * @opt: option identifier
1484  * @ov: pointer to new option value
1485  * @ol: length of option value
1486  *
1487  * For stream sockets only, accepts and ignores all IPPROTO_TCP options
1488  * (to ease compatibility).
1489  *
1490  * Returns 0 on success, errno otherwise
1491  */
1492 
1493 static int setsockopt(struct socket *sock,
1494 		      int lvl, int opt, char __user *ov, int ol)
1495 {
1496 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1497 	u32 value;
1498 	int res;
1499 
1500 	if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1501 		return 0;
1502 	if (lvl != SOL_TIPC)
1503 		return -ENOPROTOOPT;
1504 	if (ol < sizeof(value))
1505 		return -EINVAL;
1506 	if ((res = get_user(value, (u32 __user *)ov)))
1507 		return res;
1508 
1509 	if (down_interruptible(&tsock->sem))
1510 		return -ERESTARTSYS;
1511 
1512 	switch (opt) {
1513 	case TIPC_IMPORTANCE:
1514 		res = tipc_set_portimportance(tsock->p->ref, value);
1515 		break;
1516 	case TIPC_SRC_DROPPABLE:
1517 		if (sock->type != SOCK_STREAM)
1518 			res = tipc_set_portunreliable(tsock->p->ref, value);
1519 		else
1520 			res = -ENOPROTOOPT;
1521 		break;
1522 	case TIPC_DEST_DROPPABLE:
1523 		res = tipc_set_portunreturnable(tsock->p->ref, value);
1524 		break;
1525 	case TIPC_CONN_TIMEOUT:
1526 		sock->sk->sk_rcvtimeo = (value * HZ / 1000);
1527 		break;
1528 	default:
1529 		res = -EINVAL;
1530 	}
1531 
1532 	up(&tsock->sem);
1533 	return res;
1534 }
1535 
1536 /**
1537  * getsockopt - get socket option
1538  * @sock: socket structure
1539  * @lvl: option level
1540  * @opt: option identifier
1541  * @ov: receptacle for option value
1542  * @ol: receptacle for length of option value
1543  *
1544  * For stream sockets only, returns 0 length result for all IPPROTO_TCP options
1545  * (to ease compatibility).
1546  *
1547  * Returns 0 on success, errno otherwise
1548  */
1549 
1550 static int getsockopt(struct socket *sock,
1551 		      int lvl, int opt, char __user *ov, int __user *ol)
1552 {
1553 	struct tipc_sock *tsock = tipc_sk(sock->sk);
1554 	int len;
1555 	u32 value;
1556 	int res;
1557 
1558 	if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1559 		return put_user(0, ol);
1560 	if (lvl != SOL_TIPC)
1561 		return -ENOPROTOOPT;
1562 	if ((res = get_user(len, ol)))
1563 		return res;
1564 
1565 	if (down_interruptible(&tsock->sem))
1566 		return -ERESTARTSYS;
1567 
1568 	switch (opt) {
1569 	case TIPC_IMPORTANCE:
1570 		res = tipc_portimportance(tsock->p->ref, &value);
1571 		break;
1572 	case TIPC_SRC_DROPPABLE:
1573 		res = tipc_portunreliable(tsock->p->ref, &value);
1574 		break;
1575 	case TIPC_DEST_DROPPABLE:
1576 		res = tipc_portunreturnable(tsock->p->ref, &value);
1577 		break;
1578 	case TIPC_CONN_TIMEOUT:
1579 		value = (sock->sk->sk_rcvtimeo * 1000) / HZ;
1580 		break;
1581 	default:
1582 		res = -EINVAL;
1583 	}
1584 
1585 	if (res) {
1586 		/* "get" failed */
1587 	}
1588 	else if (len < sizeof(value)) {
1589 		res = -EINVAL;
1590 	}
1591 	else if ((res = copy_to_user(ov, &value, sizeof(value)))) {
1592 		/* couldn't return value */
1593 	}
1594 	else {
1595 		res = put_user(sizeof(value), ol);
1596 	}
1597 
1598 	up(&tsock->sem);
1599 	return res;
1600 }
1601 
1602 /**
1603  * Placeholders for non-implemented functionality
1604  *
1605  * Returns error code (POSIX-compliant where defined)
1606  */
1607 
1608 static int ioctl(struct socket *s, u32 cmd, unsigned long arg)
1609 {
1610 	return -EINVAL;
1611 }
1612 
1613 static int no_mmap(struct file *file, struct socket *sock,
1614 		   struct vm_area_struct *vma)
1615 {
1616 	return -EINVAL;
1617 }
1618 static ssize_t no_sendpage(struct socket *sock, struct page *page,
1619 			   int offset, size_t size, int flags)
1620 {
1621 	return -EINVAL;
1622 }
1623 
1624 static int no_skpair(struct socket *s1, struct socket *s2)
1625 {
1626 	return -EOPNOTSUPP;
1627 }
1628 
1629 /**
1630  * Protocol switches for the various types of TIPC sockets
1631  */
1632 
1633 static struct proto_ops msg_ops = {
1634 	.owner 		= THIS_MODULE,
1635 	.family		= AF_TIPC,
1636 	.release	= release,
1637 	.bind		= bind,
1638 	.connect	= connect,
1639 	.socketpair	= no_skpair,
1640 	.accept		= accept,
1641 	.getname	= get_name,
1642 	.poll		= poll,
1643 	.ioctl		= ioctl,
1644 	.listen		= listen,
1645 	.shutdown	= shutdown,
1646 	.setsockopt	= setsockopt,
1647 	.getsockopt	= getsockopt,
1648 	.sendmsg	= send_msg,
1649 	.recvmsg	= recv_msg,
1650 	.mmap		= no_mmap,
1651 	.sendpage	= no_sendpage
1652 };
1653 
1654 static struct proto_ops packet_ops = {
1655 	.owner 		= THIS_MODULE,
1656 	.family		= AF_TIPC,
1657 	.release	= release,
1658 	.bind		= bind,
1659 	.connect	= connect,
1660 	.socketpair	= no_skpair,
1661 	.accept		= accept,
1662 	.getname	= get_name,
1663 	.poll		= poll,
1664 	.ioctl		= ioctl,
1665 	.listen		= listen,
1666 	.shutdown	= shutdown,
1667 	.setsockopt	= setsockopt,
1668 	.getsockopt	= getsockopt,
1669 	.sendmsg	= send_packet,
1670 	.recvmsg	= recv_msg,
1671 	.mmap		= no_mmap,
1672 	.sendpage	= no_sendpage
1673 };
1674 
1675 static struct proto_ops stream_ops = {
1676 	.owner 		= THIS_MODULE,
1677 	.family		= AF_TIPC,
1678 	.release	= release,
1679 	.bind		= bind,
1680 	.connect	= connect,
1681 	.socketpair	= no_skpair,
1682 	.accept		= accept,
1683 	.getname	= get_name,
1684 	.poll		= poll,
1685 	.ioctl		= ioctl,
1686 	.listen		= listen,
1687 	.shutdown	= shutdown,
1688 	.setsockopt	= setsockopt,
1689 	.getsockopt	= getsockopt,
1690 	.sendmsg	= send_stream,
1691 	.recvmsg	= recv_stream,
1692 	.mmap		= no_mmap,
1693 	.sendpage	= no_sendpage
1694 };
1695 
1696 static struct net_proto_family tipc_family_ops = {
1697 	.owner 		= THIS_MODULE,
1698 	.family		= AF_TIPC,
1699 	.create		= tipc_create
1700 };
1701 
1702 static struct proto tipc_proto = {
1703 	.name		= "TIPC",
1704 	.owner		= THIS_MODULE,
1705 	.obj_size	= sizeof(struct tipc_sock)
1706 };
1707 
1708 /**
1709  * tipc_socket_init - initialize TIPC socket interface
1710  *
1711  * Returns 0 on success, errno otherwise
1712  */
1713 int tipc_socket_init(void)
1714 {
1715 	int res;
1716 
1717 	res = proto_register(&tipc_proto, 1);
1718 	if (res) {
1719 		err("Failed to register TIPC protocol type\n");
1720 		goto out;
1721 	}
1722 
1723 	res = sock_register(&tipc_family_ops);
1724 	if (res) {
1725 		err("Failed to register TIPC socket type\n");
1726 		proto_unregister(&tipc_proto);
1727 		goto out;
1728 	}
1729 
1730 	sockets_enabled = 1;
1731  out:
1732 	return res;
1733 }
1734 
1735 /**
1736  * tipc_socket_stop - stop TIPC socket interface
1737  */
1738 void tipc_socket_stop(void)
1739 {
1740 	if (!sockets_enabled)
1741 		return;
1742 
1743 	sockets_enabled = 0;
1744 	sock_unregister(tipc_family_ops.family);
1745 	proto_unregister(&tipc_proto);
1746 }
1747 
1748