xref: /linux/net/phonet/socket.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb) 
1 /*
2  * File: socket.c
3  *
4  * Phonet sockets
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9  * Original author: Sakari Ailus <sakari.ailus@nokia.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * version 2 as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23  * 02110-1301 USA
24  */
25 
26 #include <linux/gfp.h>
27 #include <linux/kernel.h>
28 #include <linux/net.h>
29 #include <linux/poll.h>
30 #include <net/sock.h>
31 #include <net/tcp_states.h>
32 
33 #include <linux/phonet.h>
34 #include <net/phonet/phonet.h>
35 #include <net/phonet/pep.h>
36 #include <net/phonet/pn_dev.h>
37 
38 static int pn_socket_release(struct socket *sock)
39 {
40 	struct sock *sk = sock->sk;
41 
42 	if (sk) {
43 		sock->sk = NULL;
44 		sk->sk_prot->close(sk, 0);
45 	}
46 	return 0;
47 }
48 
49 #define PN_HASHSIZE	16
50 #define PN_HASHMASK	(PN_HASHSIZE-1)
51 
52 
53 static struct  {
54 	struct hlist_head hlist[PN_HASHSIZE];
55 	spinlock_t lock;
56 } pnsocks;
57 
58 void __init pn_sock_init(void)
59 {
60 	unsigned i;
61 
62 	for (i = 0; i < PN_HASHSIZE; i++)
63 		INIT_HLIST_HEAD(pnsocks.hlist + i);
64 	spin_lock_init(&pnsocks.lock);
65 }
66 
67 static struct hlist_head *pn_hash_list(u16 obj)
68 {
69 	return pnsocks.hlist + (obj & PN_HASHMASK);
70 }
71 
72 /*
73  * Find address based on socket address, match only certain fields.
74  * Also grab sock if it was found. Remember to sock_put it later.
75  */
76 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
77 {
78 	struct hlist_node *node;
79 	struct sock *sknode;
80 	struct sock *rval = NULL;
81 	u16 obj = pn_sockaddr_get_object(spn);
82 	u8 res = spn->spn_resource;
83 	struct hlist_head *hlist = pn_hash_list(obj);
84 
85 	spin_lock_bh(&pnsocks.lock);
86 
87 	sk_for_each(sknode, node, hlist) {
88 		struct pn_sock *pn = pn_sk(sknode);
89 		BUG_ON(!pn->sobject); /* unbound socket */
90 
91 		if (!net_eq(sock_net(sknode), net))
92 			continue;
93 		if (pn_port(obj)) {
94 			/* Look up socket by port */
95 			if (pn_port(pn->sobject) != pn_port(obj))
96 				continue;
97 		} else {
98 			/* If port is zero, look up by resource */
99 			if (pn->resource != res)
100 				continue;
101 		}
102 		if (pn_addr(pn->sobject) &&
103 		    pn_addr(pn->sobject) != pn_addr(obj))
104 			continue;
105 
106 		rval = sknode;
107 		sock_hold(sknode);
108 		break;
109 	}
110 
111 	spin_unlock_bh(&pnsocks.lock);
112 
113 	return rval;
114 }
115 
116 /* Deliver a broadcast packet (only in bottom-half) */
117 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
118 {
119 	struct hlist_head *hlist = pnsocks.hlist;
120 	unsigned h;
121 
122 	spin_lock(&pnsocks.lock);
123 	for (h = 0; h < PN_HASHSIZE; h++) {
124 		struct hlist_node *node;
125 		struct sock *sknode;
126 
127 		sk_for_each(sknode, node, hlist) {
128 			struct sk_buff *clone;
129 
130 			if (!net_eq(sock_net(sknode), net))
131 				continue;
132 			if (!sock_flag(sknode, SOCK_BROADCAST))
133 				continue;
134 
135 			clone = skb_clone(skb, GFP_ATOMIC);
136 			if (clone) {
137 				sock_hold(sknode);
138 				sk_receive_skb(sknode, clone, 0);
139 			}
140 		}
141 		hlist++;
142 	}
143 	spin_unlock(&pnsocks.lock);
144 }
145 
146 void pn_sock_hash(struct sock *sk)
147 {
148 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
149 
150 	spin_lock_bh(&pnsocks.lock);
151 	sk_add_node(sk, hlist);
152 	spin_unlock_bh(&pnsocks.lock);
153 }
154 EXPORT_SYMBOL(pn_sock_hash);
155 
156 void pn_sock_unhash(struct sock *sk)
157 {
158 	spin_lock_bh(&pnsocks.lock);
159 	sk_del_node_init(sk);
160 	spin_unlock_bh(&pnsocks.lock);
161 }
162 EXPORT_SYMBOL(pn_sock_unhash);
163 
164 static DEFINE_MUTEX(port_mutex);
165 
166 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
167 {
168 	struct sock *sk = sock->sk;
169 	struct pn_sock *pn = pn_sk(sk);
170 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
171 	int err;
172 	u16 handle;
173 	u8 saddr;
174 
175 	if (sk->sk_prot->bind)
176 		return sk->sk_prot->bind(sk, addr, len);
177 
178 	if (len < sizeof(struct sockaddr_pn))
179 		return -EINVAL;
180 	if (spn->spn_family != AF_PHONET)
181 		return -EAFNOSUPPORT;
182 
183 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
184 	saddr = pn_addr(handle);
185 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
186 		return -EADDRNOTAVAIL;
187 
188 	lock_sock(sk);
189 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
190 		err = -EINVAL; /* attempt to rebind */
191 		goto out;
192 	}
193 	WARN_ON(sk_hashed(sk));
194 	mutex_lock(&port_mutex);
195 	err = sk->sk_prot->get_port(sk, pn_port(handle));
196 	if (err)
197 		goto out_port;
198 
199 	/* get_port() sets the port, bind() sets the address if applicable */
200 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
201 	pn->resource = spn->spn_resource;
202 
203 	/* Enable RX on the socket */
204 	sk->sk_prot->hash(sk);
205 out_port:
206 	mutex_unlock(&port_mutex);
207 out:
208 	release_sock(sk);
209 	return err;
210 }
211 
212 static int pn_socket_autobind(struct socket *sock)
213 {
214 	struct sockaddr_pn sa;
215 	int err;
216 
217 	memset(&sa, 0, sizeof(sa));
218 	sa.spn_family = AF_PHONET;
219 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
220 				sizeof(struct sockaddr_pn));
221 	if (err != -EINVAL)
222 		return err;
223 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
224 	return 0; /* socket was already bound */
225 }
226 
227 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
228 				int flags)
229 {
230 	struct sock *sk = sock->sk;
231 	struct sock *newsk;
232 	int err;
233 
234 	newsk = sk->sk_prot->accept(sk, flags, &err);
235 	if (!newsk)
236 		return err;
237 
238 	lock_sock(newsk);
239 	sock_graft(newsk, newsock);
240 	newsock->state = SS_CONNECTED;
241 	release_sock(newsk);
242 	return 0;
243 }
244 
245 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
246 				int *sockaddr_len, int peer)
247 {
248 	struct sock *sk = sock->sk;
249 	struct pn_sock *pn = pn_sk(sk);
250 
251 	memset(addr, 0, sizeof(struct sockaddr_pn));
252 	addr->sa_family = AF_PHONET;
253 	if (!peer) /* Race with bind() here is userland's problem. */
254 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
255 					pn->sobject);
256 
257 	*sockaddr_len = sizeof(struct sockaddr_pn);
258 	return 0;
259 }
260 
261 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
262 					poll_table *wait)
263 {
264 	struct sock *sk = sock->sk;
265 	struct pep_sock *pn = pep_sk(sk);
266 	unsigned int mask = 0;
267 
268 	poll_wait(file, sk_sleep(sk), wait);
269 
270 	switch (sk->sk_state) {
271 	case TCP_LISTEN:
272 		return hlist_empty(&pn->ackq) ? 0 : POLLIN;
273 	case TCP_CLOSE:
274 		return POLLERR;
275 	}
276 
277 	if (!skb_queue_empty(&sk->sk_receive_queue))
278 		mask |= POLLIN | POLLRDNORM;
279 	if (!skb_queue_empty(&pn->ctrlreq_queue))
280 		mask |= POLLPRI;
281 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
282 		return POLLHUP;
283 
284 	if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
285 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
286 
287 	return mask;
288 }
289 
290 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
291 				unsigned long arg)
292 {
293 	struct sock *sk = sock->sk;
294 	struct pn_sock *pn = pn_sk(sk);
295 
296 	if (cmd == SIOCPNGETOBJECT) {
297 		struct net_device *dev;
298 		u16 handle;
299 		u8 saddr;
300 
301 		if (get_user(handle, (__u16 __user *)arg))
302 			return -EFAULT;
303 
304 		lock_sock(sk);
305 		if (sk->sk_bound_dev_if)
306 			dev = dev_get_by_index(sock_net(sk),
307 						sk->sk_bound_dev_if);
308 		else
309 			dev = phonet_device_get(sock_net(sk));
310 		if (dev && (dev->flags & IFF_UP))
311 			saddr = phonet_address_get(dev, pn_addr(handle));
312 		else
313 			saddr = PN_NO_ADDR;
314 		release_sock(sk);
315 
316 		if (dev)
317 			dev_put(dev);
318 		if (saddr == PN_NO_ADDR)
319 			return -EHOSTUNREACH;
320 
321 		handle = pn_object(saddr, pn_port(pn->sobject));
322 		return put_user(handle, (__u16 __user *)arg);
323 	}
324 
325 	return sk->sk_prot->ioctl(sk, cmd, arg);
326 }
327 
328 static int pn_socket_listen(struct socket *sock, int backlog)
329 {
330 	struct sock *sk = sock->sk;
331 	int err = 0;
332 
333 	if (sock->state != SS_UNCONNECTED)
334 		return -EINVAL;
335 	if (pn_socket_autobind(sock))
336 		return -ENOBUFS;
337 
338 	lock_sock(sk);
339 	if (sk->sk_state != TCP_CLOSE) {
340 		err = -EINVAL;
341 		goto out;
342 	}
343 
344 	sk->sk_state = TCP_LISTEN;
345 	sk->sk_ack_backlog = 0;
346 	sk->sk_max_ack_backlog = backlog;
347 out:
348 	release_sock(sk);
349 	return err;
350 }
351 
352 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
353 				struct msghdr *m, size_t total_len)
354 {
355 	struct sock *sk = sock->sk;
356 
357 	if (pn_socket_autobind(sock))
358 		return -EAGAIN;
359 
360 	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
361 }
362 
363 const struct proto_ops phonet_dgram_ops = {
364 	.family		= AF_PHONET,
365 	.owner		= THIS_MODULE,
366 	.release	= pn_socket_release,
367 	.bind		= pn_socket_bind,
368 	.connect	= sock_no_connect,
369 	.socketpair	= sock_no_socketpair,
370 	.accept		= sock_no_accept,
371 	.getname	= pn_socket_getname,
372 	.poll		= datagram_poll,
373 	.ioctl		= pn_socket_ioctl,
374 	.listen		= sock_no_listen,
375 	.shutdown	= sock_no_shutdown,
376 	.setsockopt	= sock_no_setsockopt,
377 	.getsockopt	= sock_no_getsockopt,
378 #ifdef CONFIG_COMPAT
379 	.compat_setsockopt = sock_no_setsockopt,
380 	.compat_getsockopt = sock_no_getsockopt,
381 #endif
382 	.sendmsg	= pn_socket_sendmsg,
383 	.recvmsg	= sock_common_recvmsg,
384 	.mmap		= sock_no_mmap,
385 	.sendpage	= sock_no_sendpage,
386 };
387 
388 const struct proto_ops phonet_stream_ops = {
389 	.family		= AF_PHONET,
390 	.owner		= THIS_MODULE,
391 	.release	= pn_socket_release,
392 	.bind		= pn_socket_bind,
393 	.connect	= sock_no_connect,
394 	.socketpair	= sock_no_socketpair,
395 	.accept		= pn_socket_accept,
396 	.getname	= pn_socket_getname,
397 	.poll		= pn_socket_poll,
398 	.ioctl		= pn_socket_ioctl,
399 	.listen		= pn_socket_listen,
400 	.shutdown	= sock_no_shutdown,
401 	.setsockopt	= sock_common_setsockopt,
402 	.getsockopt	= sock_common_getsockopt,
403 #ifdef CONFIG_COMPAT
404 	.compat_setsockopt = compat_sock_common_setsockopt,
405 	.compat_getsockopt = compat_sock_common_getsockopt,
406 #endif
407 	.sendmsg	= pn_socket_sendmsg,
408 	.recvmsg	= sock_common_recvmsg,
409 	.mmap		= sock_no_mmap,
410 	.sendpage	= sock_no_sendpage,
411 };
412 EXPORT_SYMBOL(phonet_stream_ops);
413 
414 /* allocate port for a socket */
415 int pn_sock_get_port(struct sock *sk, unsigned short sport)
416 {
417 	static int port_cur;
418 	struct net *net = sock_net(sk);
419 	struct pn_sock *pn = pn_sk(sk);
420 	struct sockaddr_pn try_sa;
421 	struct sock *tmpsk;
422 
423 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
424 	try_sa.spn_family = AF_PHONET;
425 	WARN_ON(!mutex_is_locked(&port_mutex));
426 	if (!sport) {
427 		/* search free port */
428 		int port, pmin, pmax;
429 
430 		phonet_get_local_port_range(&pmin, &pmax);
431 		for (port = pmin; port <= pmax; port++) {
432 			port_cur++;
433 			if (port_cur < pmin || port_cur > pmax)
434 				port_cur = pmin;
435 
436 			pn_sockaddr_set_port(&try_sa, port_cur);
437 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
438 			if (tmpsk == NULL) {
439 				sport = port_cur;
440 				goto found;
441 			} else
442 				sock_put(tmpsk);
443 		}
444 	} else {
445 		/* try to find specific port */
446 		pn_sockaddr_set_port(&try_sa, sport);
447 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
448 		if (tmpsk == NULL)
449 			/* No sock there! We can use that port... */
450 			goto found;
451 		else
452 			sock_put(tmpsk);
453 	}
454 	/* the port must be in use already */
455 	return -EADDRINUSE;
456 
457 found:
458 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
459 	return 0;
460 }
461 EXPORT_SYMBOL(pn_sock_get_port);
462 
463 #ifdef CONFIG_PROC_FS
464 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
465 {
466 	struct net *net = seq_file_net(seq);
467 	struct hlist_head *hlist = pnsocks.hlist;
468 	struct hlist_node *node;
469 	struct sock *sknode;
470 	unsigned h;
471 
472 	for (h = 0; h < PN_HASHSIZE; h++) {
473 		sk_for_each(sknode, node, hlist) {
474 			if (!net_eq(net, sock_net(sknode)))
475 				continue;
476 			if (!pos)
477 				return sknode;
478 			pos--;
479 		}
480 		hlist++;
481 	}
482 	return NULL;
483 }
484 
485 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
486 {
487 	struct net *net = seq_file_net(seq);
488 
489 	do
490 		sk = sk_next(sk);
491 	while (sk && !net_eq(net, sock_net(sk)));
492 
493 	return sk;
494 }
495 
496 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
497 	__acquires(pnsocks.lock)
498 {
499 	spin_lock_bh(&pnsocks.lock);
500 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
501 }
502 
503 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
504 {
505 	struct sock *sk;
506 
507 	if (v == SEQ_START_TOKEN)
508 		sk = pn_sock_get_idx(seq, 0);
509 	else
510 		sk = pn_sock_get_next(seq, v);
511 	(*pos)++;
512 	return sk;
513 }
514 
515 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
516 	__releases(pnsocks.lock)
517 {
518 	spin_unlock_bh(&pnsocks.lock);
519 }
520 
521 static int pn_sock_seq_show(struct seq_file *seq, void *v)
522 {
523 	int len;
524 
525 	if (v == SEQ_START_TOKEN)
526 		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
527 			"  uid inode ref pointer drops", &len);
528 	else {
529 		struct sock *sk = v;
530 		struct pn_sock *pn = pn_sk(sk);
531 
532 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
533 			"%d %p %d%n",
534 			sk->sk_protocol, pn->sobject, 0, pn->resource,
535 			sk->sk_state,
536 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
537 			sock_i_uid(sk), sock_i_ino(sk),
538 			atomic_read(&sk->sk_refcnt), sk,
539 			atomic_read(&sk->sk_drops), &len);
540 	}
541 	seq_printf(seq, "%*s\n", 127 - len, "");
542 	return 0;
543 }
544 
545 static const struct seq_operations pn_sock_seq_ops = {
546 	.start = pn_sock_seq_start,
547 	.next = pn_sock_seq_next,
548 	.stop = pn_sock_seq_stop,
549 	.show = pn_sock_seq_show,
550 };
551 
552 static int pn_sock_open(struct inode *inode, struct file *file)
553 {
554 	return seq_open_net(inode, file, &pn_sock_seq_ops,
555 				sizeof(struct seq_net_private));
556 }
557 
558 const struct file_operations pn_sock_seq_fops = {
559 	.owner = THIS_MODULE,
560 	.open = pn_sock_open,
561 	.read = seq_read,
562 	.llseek = seq_lseek,
563 	.release = seq_release_net,
564 };
565 #endif
566