summaryrefslogtreecommitdiffstats
path: root/net/phonet/socket.c
blob: 99a4945d565dcf89932d4ffc443a86702462a113 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/*
 * File: socket.c
 *
 * Phonet sockets
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/kernel.h>
#include <linux/net.h>
#include <net/sock.h>
#include <net/tcp_states.h>

#include <linux/phonet.h>
#include <net/phonet/phonet.h>
#include <net/phonet/pn_dev.h>

static int pn_socket_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	if (sk) {
		sock->sk = NULL;
		sk->sk_prot->close(sk, 0);
	}
	return 0;
}

static struct  {
	struct hlist_head hlist;
	spinlock_t lock;
} pnsocks = {
	.hlist = HLIST_HEAD_INIT,
	.lock = __SPIN_LOCK_UNLOCKED(pnsocks.lock),
};

/*
 * Find address based on socket address, match only certain fields.
 * Also grab sock if it was found. Remember to sock_put it later.
 */
struct sock *pn_find_sock_by_sa(const struct sockaddr_pn *spn)
{
	struct hlist_node *node;
	struct sock *sknode;
	struct sock *rval = NULL;
	u16 obj = pn_sockaddr_get_object(spn);
	u8 res = spn->spn_resource;

	spin_lock_bh(&pnsocks.lock);

	sk_for_each(sknode, node, &pnsocks.hlist) {
		struct pn_sock *pn = pn_sk(sknode);
		BUG_ON(!pn->sobject); /* unbound socket */

		if (pn_port(obj)) {
			/* Look up socket by port */
			if (pn_port(pn->sobject) != pn_port(obj))
				continue;
		} else {
			/* If port is zero, look up by resource */
			if (pn->resource != res)
				continue;
		}
		if (pn_addr(pn->sobject)
		 && pn_addr(pn->sobject) != pn_addr(obj))
			continue;

		rval = sknode;
		sock_hold(sknode);
		break;
	}

	spin_unlock_bh(&pnsocks.lock);

	return rval;

}

void pn_sock_hash(struct sock *sk)
{
	spin_lock_bh(&pnsocks.lock);
	sk_add_node(sk, &pnsocks.hlist);
	spin_unlock_bh(&pnsocks.lock);
}
EXPORT_SYMBOL(pn_sock_hash);

void pn_sock_unhash(struct sock *sk)
{
	spin_lock_bh(&pnsocks.lock);
	sk_del_node_init(sk);
	spin_unlock_bh(&pnsocks.lock);
}
EXPORT_SYMBOL(pn_sock_unhash);

static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);
	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
	int err;
	u16 handle;
	u8 saddr;

	if (sk->sk_prot->bind)
		return sk->sk_prot->bind(sk, addr, len);

	if (len < sizeof(struct sockaddr_pn))
		return -EINVAL;
	if (spn->spn_family != AF_PHONET)
		return -EAFNOSUPPORT;

	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
	saddr = pn_addr(handle);
	if (saddr && phonet_address_lookup(saddr))
		return -EADDRNOTAVAIL;

	lock_sock(sk);
	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
		err = -EINVAL; /* attempt to rebind */
		goto out;
	}
	err = sk->sk_prot->get_port(sk, pn_port(handle));
	if (err)
		goto out;

	/* get_port() sets the port, bind() sets the address if applicable */
	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
	pn->resource = spn->spn_resource;

	/* Enable RX on the socket */
	sk->sk_prot->hash(sk);
out:
	release_sock(sk);
	return err;
}

static int pn_socket_autobind(struct socket *sock)
{
	struct sockaddr_pn sa;
	int err;

	memset(&sa, 0, sizeof(sa));
	sa.spn_family = AF_PHONET;
	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
				sizeof(struct sockaddr_pn));
	if (err != -EINVAL)
		return err;
	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
	return 0; /* socket was already bound */
}

static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
				int *sockaddr_len, int peer)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);

	memset(addr, 0, sizeof(struct sockaddr_pn));
	addr->sa_family = AF_PHONET;
	if (!peer) /* Race with bind() here is userland's problem. */
		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
					pn->sobject);

	*sockaddr_len = sizeof(struct sockaddr_pn);
	return 0;
}

static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
				unsigned long arg)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);

	if (cmd == SIOCPNGETOBJECT) {
		struct net_device *dev;
		u16 handle;
		u8 saddr;

		if (get_user(handle, (__u16 __user *)arg))
			return -EFAULT;

		lock_sock(sk);
		if (sk->sk_bound_dev_if)
			dev = dev_get_by_index(sock_net(sk),
						sk->sk_bound_dev_if);
		else
			dev = phonet_device_get(sock_net(sk));
		if (dev && (dev->flags & IFF_UP))
			saddr = phonet_address_get(dev, pn_addr(handle));
		else
			saddr = PN_NO_ADDR;
		release_sock(sk);

		if (dev)
			dev_put(dev);
		if (saddr == PN_NO_ADDR)
			return -EHOSTUNREACH;

		handle = pn_object(saddr, pn_port(pn->sobject));
		return put_user(handle, (__u16 __user *)arg);
	}

	return sk->sk_prot->ioctl(sk, cmd, arg);
}

static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
				struct msghdr *m, size_t total_len)
{
	struct sock *sk = sock->sk;

	if (pn_socket_autobind(sock))
		return -EAGAIN;

	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
}

const struct proto_ops phonet_dgram_ops = {
	.family		= AF_PHONET,
	.owner		= THIS_MODULE,
	.release	= pn_socket_release,
	.bind		= pn_socket_bind,
	.connect	= sock_no_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= sock_no_accept,
	.getname	= pn_socket_getname,
	.poll		= datagram_poll,
	.ioctl		= pn_socket_ioctl,
	.listen		= sock_no_listen,
	.shutdown	= sock_no_shutdown,
	.setsockopt	= sock_no_setsockopt,
	.getsockopt	= sock_no_getsockopt,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = sock_no_setsockopt,
	.compat_getsockopt = sock_no_getsockopt,
#endif
	.sendmsg	= pn_socket_sendmsg,
	.recvmsg	= sock_common_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

static DEFINE_MUTEX(port_mutex);

/* allocate port for a socket */
int pn_sock_get_port(struct sock *sk, unsigned short sport)
{
	static int port_cur;
	struct pn_sock *pn = pn_sk(sk);
	struct sockaddr_pn try_sa;
	struct sock *tmpsk;

	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
	try_sa.spn_family = AF_PHONET;

	mutex_lock(&port_mutex);

	if (!sport) {
		/* search free port */
		int port, pmin = 0x40, pmax = 0x7f;

		for (port = pmin; port <= pmax; port++) {
			port_cur++;
			if (port_cur < pmin || port_cur > pmax)
				port_cur = pmin;

			pn_sockaddr_set_port(&try_sa, port_cur);
			tmpsk = pn_find_sock_by_sa(&try_sa);
			if (tmpsk == NULL) {
				sport = port_cur;
				goto found;
			} else
				sock_put(tmpsk);
		}
	} else {
		/* try to find specific port */
		pn_sockaddr_set_port(&try_sa, sport);
		tmpsk = pn_find_sock_by_sa(&try_sa);
		if (tmpsk == NULL)
			/* No sock there! We can use that port... */
			goto found;
		else
			sock_put(tmpsk);
	}
	mutex_unlock(&port_mutex);

	/* the port must be in use already */
	return -EADDRINUSE;

found:
	mutex_unlock(&port_mutex);
	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
	return 0;
}
EXPORT_SYMBOL(pn_sock_get_port);