socket.c revision 9995a32b4d14dcda2f8df58030526bee91114c16 
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/kernel.h>
27#include <linux/net.h>
28#include <linux/poll.h>
29#include <net/sock.h>
30#include <net/tcp_states.h>
31
32#include <linux/phonet.h>
33#include <net/phonet/phonet.h>
34#include <net/phonet/pep.h>
35#include <net/phonet/pn_dev.h>
36
37static int pn_socket_release(struct socket *sock)
38{
39	struct sock *sk = sock->sk;
40
41	if (sk) {
42		sock->sk = NULL;
43		sk->sk_prot->close(sk, 0);
44	}
45	return 0;
46}
47
48static struct  {
49	struct hlist_head hlist;
50	spinlock_t lock;
51} pnsocks = {
52	.hlist = HLIST_HEAD_INIT,
53	.lock = __SPIN_LOCK_UNLOCKED(pnsocks.lock),
54};
55
56/*
57 * Find address based on socket address, match only certain fields.
58 * Also grab sock if it was found. Remember to sock_put it later.
59 */
60struct sock *pn_find_sock_by_sa(const struct sockaddr_pn *spn)
61{
62	struct hlist_node *node;
63	struct sock *sknode;
64	struct sock *rval = NULL;
65	u16 obj = pn_sockaddr_get_object(spn);
66	u8 res = spn->spn_resource;
67
68	spin_lock_bh(&pnsocks.lock);
69
70	sk_for_each(sknode, node, &pnsocks.hlist) {
71		struct pn_sock *pn = pn_sk(sknode);
72		BUG_ON(!pn->sobject); /* unbound socket */
73
74		if (pn_port(obj)) {
75			/* Look up socket by port */
76			if (pn_port(pn->sobject) != pn_port(obj))
77				continue;
78		} else {
79			/* If port is zero, look up by resource */
80			if (pn->resource != res)
81				continue;
82		}
83		if (pn_addr(pn->sobject)
84		 && pn_addr(pn->sobject) != pn_addr(obj))
85			continue;
86
87		rval = sknode;
88		sock_hold(sknode);
89		break;
90	}
91
92	spin_unlock_bh(&pnsocks.lock);
93
94	return rval;
95
96}
97
98void pn_sock_hash(struct sock *sk)
99{
100	spin_lock_bh(&pnsocks.lock);
101	sk_add_node(sk, &pnsocks.hlist);
102	spin_unlock_bh(&pnsocks.lock);
103}
104EXPORT_SYMBOL(pn_sock_hash);
105
106void pn_sock_unhash(struct sock *sk)
107{
108	spin_lock_bh(&pnsocks.lock);
109	sk_del_node_init(sk);
110	spin_unlock_bh(&pnsocks.lock);
111}
112EXPORT_SYMBOL(pn_sock_unhash);
113
114static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
115{
116	struct sock *sk = sock->sk;
117	struct pn_sock *pn = pn_sk(sk);
118	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
119	int err;
120	u16 handle;
121	u8 saddr;
122
123	if (sk->sk_prot->bind)
124		return sk->sk_prot->bind(sk, addr, len);
125
126	if (len < sizeof(struct sockaddr_pn))
127		return -EINVAL;
128	if (spn->spn_family != AF_PHONET)
129		return -EAFNOSUPPORT;
130
131	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
132	saddr = pn_addr(handle);
133	if (saddr && phonet_address_lookup(saddr))
134		return -EADDRNOTAVAIL;
135
136	lock_sock(sk);
137	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
138		err = -EINVAL; /* attempt to rebind */
139		goto out;
140	}
141	err = sk->sk_prot->get_port(sk, pn_port(handle));
142	if (err)
143		goto out;
144
145	/* get_port() sets the port, bind() sets the address if applicable */
146	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
147	pn->resource = spn->spn_resource;
148
149	/* Enable RX on the socket */
150	sk->sk_prot->hash(sk);
151out:
152	release_sock(sk);
153	return err;
154}
155
156static int pn_socket_autobind(struct socket *sock)
157{
158	struct sockaddr_pn sa;
159	int err;
160
161	memset(&sa, 0, sizeof(sa));
162	sa.spn_family = AF_PHONET;
163	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
164				sizeof(struct sockaddr_pn));
165	if (err != -EINVAL)
166		return err;
167	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
168	return 0; /* socket was already bound */
169}
170
171static int pn_socket_accept(struct socket *sock, struct socket *newsock,
172				int flags)
173{
174	struct sock *sk = sock->sk;
175	struct sock *newsk;
176	int err;
177
178	newsk = sk->sk_prot->accept(sk, flags, &err);
179	if (!newsk)
180		return err;
181
182	lock_sock(newsk);
183	sock_graft(newsk, newsock);
184	newsock->state = SS_CONNECTED;
185	release_sock(newsk);
186	return 0;
187}
188
189static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
190				int *sockaddr_len, int peer)
191{
192	struct sock *sk = sock->sk;
193	struct pn_sock *pn = pn_sk(sk);
194
195	memset(addr, 0, sizeof(struct sockaddr_pn));
196	addr->sa_family = AF_PHONET;
197	if (!peer) /* Race with bind() here is userland's problem. */
198		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
199					pn->sobject);
200
201	*sockaddr_len = sizeof(struct sockaddr_pn);
202	return 0;
203}
204
205static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
206					poll_table *wait)
207{
208	struct sock *sk = sock->sk;
209	struct pep_sock *pn = pep_sk(sk);
210	unsigned int mask = 0;
211
212	poll_wait(file, &sock->wait, wait);
213
214	switch (sk->sk_state) {
215	case TCP_LISTEN:
216		return hlist_empty(&pn->ackq) ? 0 : POLLIN;
217	case TCP_CLOSE:
218		return POLLERR;
219	}
220
221	if (!skb_queue_empty(&sk->sk_receive_queue))
222		mask |= POLLIN | POLLRDNORM;
223	else if (sk->sk_state == TCP_CLOSE_WAIT)
224		return POLLHUP;
225
226	if (sk->sk_state == TCP_ESTABLISHED && pn->tx_credits)
227		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
228
229	return mask;
230}
231
232static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
233				unsigned long arg)
234{
235	struct sock *sk = sock->sk;
236	struct pn_sock *pn = pn_sk(sk);
237
238	if (cmd == SIOCPNGETOBJECT) {
239		struct net_device *dev;
240		u16 handle;
241		u8 saddr;
242
243		if (get_user(handle, (__u16 __user *)arg))
244			return -EFAULT;
245
246		lock_sock(sk);
247		if (sk->sk_bound_dev_if)
248			dev = dev_get_by_index(sock_net(sk),
249						sk->sk_bound_dev_if);
250		else
251			dev = phonet_device_get(sock_net(sk));
252		if (dev && (dev->flags & IFF_UP))
253			saddr = phonet_address_get(dev, pn_addr(handle));
254		else
255			saddr = PN_NO_ADDR;
256		release_sock(sk);
257
258		if (dev)
259			dev_put(dev);
260		if (saddr == PN_NO_ADDR)
261			return -EHOSTUNREACH;
262
263		handle = pn_object(saddr, pn_port(pn->sobject));
264		return put_user(handle, (__u16 __user *)arg);
265	}
266
267	return sk->sk_prot->ioctl(sk, cmd, arg);
268}
269
270static int pn_socket_listen(struct socket *sock, int backlog)
271{
272	struct sock *sk = sock->sk;
273	int err = 0;
274
275	if (sock->state != SS_UNCONNECTED)
276		return -EINVAL;
277	if (pn_socket_autobind(sock))
278		return -ENOBUFS;
279
280	lock_sock(sk);
281	if (sk->sk_state != TCP_CLOSE) {
282		err = -EINVAL;
283		goto out;
284	}
285
286	sk->sk_state = TCP_LISTEN;
287	sk->sk_ack_backlog = 0;
288	sk->sk_max_ack_backlog = backlog;
289out:
290	release_sock(sk);
291	return err;
292}
293
294static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
295				struct msghdr *m, size_t total_len)
296{
297	struct sock *sk = sock->sk;
298
299	if (pn_socket_autobind(sock))
300		return -EAGAIN;
301
302	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
303}
304
305const struct proto_ops phonet_dgram_ops = {
306	.family		= AF_PHONET,
307	.owner		= THIS_MODULE,
308	.release	= pn_socket_release,
309	.bind		= pn_socket_bind,
310	.connect	= sock_no_connect,
311	.socketpair	= sock_no_socketpair,
312	.accept		= sock_no_accept,
313	.getname	= pn_socket_getname,
314	.poll		= datagram_poll,
315	.ioctl		= pn_socket_ioctl,
316	.listen		= sock_no_listen,
317	.shutdown	= sock_no_shutdown,
318	.setsockopt	= sock_no_setsockopt,
319	.getsockopt	= sock_no_getsockopt,
320#ifdef CONFIG_COMPAT
321	.compat_setsockopt = sock_no_setsockopt,
322	.compat_getsockopt = sock_no_getsockopt,
323#endif
324	.sendmsg	= pn_socket_sendmsg,
325	.recvmsg	= sock_common_recvmsg,
326	.mmap		= sock_no_mmap,
327	.sendpage	= sock_no_sendpage,
328};
329
330const struct proto_ops phonet_stream_ops = {
331	.family		= AF_PHONET,
332	.owner		= THIS_MODULE,
333	.release	= pn_socket_release,
334	.bind		= pn_socket_bind,
335	.connect	= sock_no_connect,
336	.socketpair	= sock_no_socketpair,
337	.accept		= pn_socket_accept,
338	.getname	= pn_socket_getname,
339	.poll		= pn_socket_poll,
340	.ioctl		= pn_socket_ioctl,
341	.listen		= pn_socket_listen,
342	.shutdown	= sock_no_shutdown,
343	.setsockopt	= sock_no_setsockopt,
344	.getsockopt	= sock_no_getsockopt,
345#ifdef CONFIG_COMPAT
346	.compat_setsockopt = sock_no_setsockopt,
347	.compat_getsockopt = compat_sock_no_getsockopt,
348#endif
349	.sendmsg	= pn_socket_sendmsg,
350	.recvmsg	= sock_common_recvmsg,
351	.mmap		= sock_no_mmap,
352	.sendpage	= sock_no_sendpage,
353};
354EXPORT_SYMBOL(phonet_stream_ops);
355
356static DEFINE_MUTEX(port_mutex);
357
358/* allocate port for a socket */
359int pn_sock_get_port(struct sock *sk, unsigned short sport)
360{
361	static int port_cur;
362	struct pn_sock *pn = pn_sk(sk);
363	struct sockaddr_pn try_sa;
364	struct sock *tmpsk;
365
366	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
367	try_sa.spn_family = AF_PHONET;
368
369	mutex_lock(&port_mutex);
370
371	if (!sport) {
372		/* search free port */
373		int port, pmin, pmax;
374
375		phonet_get_local_port_range(&pmin, &pmax);
376		for (port = pmin; port <= pmax; port++) {
377			port_cur++;
378			if (port_cur < pmin || port_cur > pmax)
379				port_cur = pmin;
380
381			pn_sockaddr_set_port(&try_sa, port_cur);
382			tmpsk = pn_find_sock_by_sa(&try_sa);
383			if (tmpsk == NULL) {
384				sport = port_cur;
385				goto found;
386			} else
387				sock_put(tmpsk);
388		}
389	} else {
390		/* try to find specific port */
391		pn_sockaddr_set_port(&try_sa, sport);
392		tmpsk = pn_find_sock_by_sa(&try_sa);
393		if (tmpsk == NULL)
394			/* No sock there! We can use that port... */
395			goto found;
396		else
397			sock_put(tmpsk);
398	}
399	mutex_unlock(&port_mutex);
400
401	/* the port must be in use already */
402	return -EADDRINUSE;
403
404found:
405	mutex_unlock(&port_mutex);
406	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
407	return 0;
408}
409EXPORT_SYMBOL(pn_sock_get_port);
410