xref: /linux/net/phonet/socket.c (revision 913df4453f85f1fe79b35ecf3c9a0c0b707d22a2)
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 
37 static 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 
48 static 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  */
60 struct sock *pn_find_sock_by_sa(struct net *net, 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 (!net_eq(sock_net(sknode), net))
75 			continue;
76 		if (pn_port(obj)) {
77 			/* Look up socket by port */
78 			if (pn_port(pn->sobject) != pn_port(obj))
79 				continue;
80 		} else {
81 			/* If port is zero, look up by resource */
82 			if (pn->resource != res)
83 				continue;
84 		}
85 		if (pn_addr(pn->sobject)
86 		 && pn_addr(pn->sobject) != pn_addr(obj))
87 			continue;
88 
89 		rval = sknode;
90 		sock_hold(sknode);
91 		break;
92 	}
93 
94 	spin_unlock_bh(&pnsocks.lock);
95 
96 	return rval;
97 
98 }
99 
100 void pn_sock_hash(struct sock *sk)
101 {
102 	spin_lock_bh(&pnsocks.lock);
103 	sk_add_node(sk, &pnsocks.hlist);
104 	spin_unlock_bh(&pnsocks.lock);
105 }
106 EXPORT_SYMBOL(pn_sock_hash);
107 
108 void pn_sock_unhash(struct sock *sk)
109 {
110 	spin_lock_bh(&pnsocks.lock);
111 	sk_del_node_init(sk);
112 	spin_unlock_bh(&pnsocks.lock);
113 }
114 EXPORT_SYMBOL(pn_sock_unhash);
115 
116 static DEFINE_MUTEX(port_mutex);
117 
118 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
119 {
120 	struct sock *sk = sock->sk;
121 	struct pn_sock *pn = pn_sk(sk);
122 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
123 	int err;
124 	u16 handle;
125 	u8 saddr;
126 
127 	if (sk->sk_prot->bind)
128 		return sk->sk_prot->bind(sk, addr, len);
129 
130 	if (len < sizeof(struct sockaddr_pn))
131 		return -EINVAL;
132 	if (spn->spn_family != AF_PHONET)
133 		return -EAFNOSUPPORT;
134 
135 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
136 	saddr = pn_addr(handle);
137 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
138 		return -EADDRNOTAVAIL;
139 
140 	lock_sock(sk);
141 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
142 		err = -EINVAL; /* attempt to rebind */
143 		goto out;
144 	}
145 	WARN_ON(sk_hashed(sk));
146 	mutex_lock(&port_mutex);
147 	err = sk->sk_prot->get_port(sk, pn_port(handle));
148 	if (err)
149 		goto out_port;
150 
151 	/* get_port() sets the port, bind() sets the address if applicable */
152 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
153 	pn->resource = spn->spn_resource;
154 
155 	/* Enable RX on the socket */
156 	sk->sk_prot->hash(sk);
157 out_port:
158 	mutex_unlock(&port_mutex);
159 out:
160 	release_sock(sk);
161 	return err;
162 }
163 
164 static int pn_socket_autobind(struct socket *sock)
165 {
166 	struct sockaddr_pn sa;
167 	int err;
168 
169 	memset(&sa, 0, sizeof(sa));
170 	sa.spn_family = AF_PHONET;
171 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
172 				sizeof(struct sockaddr_pn));
173 	if (err != -EINVAL)
174 		return err;
175 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
176 	return 0; /* socket was already bound */
177 }
178 
179 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
180 				int flags)
181 {
182 	struct sock *sk = sock->sk;
183 	struct sock *newsk;
184 	int err;
185 
186 	newsk = sk->sk_prot->accept(sk, flags, &err);
187 	if (!newsk)
188 		return err;
189 
190 	lock_sock(newsk);
191 	sock_graft(newsk, newsock);
192 	newsock->state = SS_CONNECTED;
193 	release_sock(newsk);
194 	return 0;
195 }
196 
197 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
198 				int *sockaddr_len, int peer)
199 {
200 	struct sock *sk = sock->sk;
201 	struct pn_sock *pn = pn_sk(sk);
202 
203 	memset(addr, 0, sizeof(struct sockaddr_pn));
204 	addr->sa_family = AF_PHONET;
205 	if (!peer) /* Race with bind() here is userland's problem. */
206 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
207 					pn->sobject);
208 
209 	*sockaddr_len = sizeof(struct sockaddr_pn);
210 	return 0;
211 }
212 
213 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
214 					poll_table *wait)
215 {
216 	struct sock *sk = sock->sk;
217 	struct pep_sock *pn = pep_sk(sk);
218 	unsigned int mask = 0;
219 
220 	poll_wait(file, &sock->wait, wait);
221 
222 	switch (sk->sk_state) {
223 	case TCP_LISTEN:
224 		return hlist_empty(&pn->ackq) ? 0 : POLLIN;
225 	case TCP_CLOSE:
226 		return POLLERR;
227 	}
228 
229 	if (!skb_queue_empty(&sk->sk_receive_queue))
230 		mask |= POLLIN | POLLRDNORM;
231 	if (!skb_queue_empty(&pn->ctrlreq_queue))
232 		mask |= POLLPRI;
233 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
234 		return POLLHUP;
235 
236 	if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
237 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
238 
239 	return mask;
240 }
241 
242 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
243 				unsigned long arg)
244 {
245 	struct sock *sk = sock->sk;
246 	struct pn_sock *pn = pn_sk(sk);
247 
248 	if (cmd == SIOCPNGETOBJECT) {
249 		struct net_device *dev;
250 		u16 handle;
251 		u8 saddr;
252 
253 		if (get_user(handle, (__u16 __user *)arg))
254 			return -EFAULT;
255 
256 		lock_sock(sk);
257 		if (sk->sk_bound_dev_if)
258 			dev = dev_get_by_index(sock_net(sk),
259 						sk->sk_bound_dev_if);
260 		else
261 			dev = phonet_device_get(sock_net(sk));
262 		if (dev && (dev->flags & IFF_UP))
263 			saddr = phonet_address_get(dev, pn_addr(handle));
264 		else
265 			saddr = PN_NO_ADDR;
266 		release_sock(sk);
267 
268 		if (dev)
269 			dev_put(dev);
270 		if (saddr == PN_NO_ADDR)
271 			return -EHOSTUNREACH;
272 
273 		handle = pn_object(saddr, pn_port(pn->sobject));
274 		return put_user(handle, (__u16 __user *)arg);
275 	}
276 
277 	return sk->sk_prot->ioctl(sk, cmd, arg);
278 }
279 
280 static int pn_socket_listen(struct socket *sock, int backlog)
281 {
282 	struct sock *sk = sock->sk;
283 	int err = 0;
284 
285 	if (sock->state != SS_UNCONNECTED)
286 		return -EINVAL;
287 	if (pn_socket_autobind(sock))
288 		return -ENOBUFS;
289 
290 	lock_sock(sk);
291 	if (sk->sk_state != TCP_CLOSE) {
292 		err = -EINVAL;
293 		goto out;
294 	}
295 
296 	sk->sk_state = TCP_LISTEN;
297 	sk->sk_ack_backlog = 0;
298 	sk->sk_max_ack_backlog = backlog;
299 out:
300 	release_sock(sk);
301 	return err;
302 }
303 
304 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
305 				struct msghdr *m, size_t total_len)
306 {
307 	struct sock *sk = sock->sk;
308 
309 	if (pn_socket_autobind(sock))
310 		return -EAGAIN;
311 
312 	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
313 }
314 
315 const struct proto_ops phonet_dgram_ops = {
316 	.family		= AF_PHONET,
317 	.owner		= THIS_MODULE,
318 	.release	= pn_socket_release,
319 	.bind		= pn_socket_bind,
320 	.connect	= sock_no_connect,
321 	.socketpair	= sock_no_socketpair,
322 	.accept		= sock_no_accept,
323 	.getname	= pn_socket_getname,
324 	.poll		= datagram_poll,
325 	.ioctl		= pn_socket_ioctl,
326 	.listen		= sock_no_listen,
327 	.shutdown	= sock_no_shutdown,
328 	.setsockopt	= sock_no_setsockopt,
329 	.getsockopt	= sock_no_getsockopt,
330 #ifdef CONFIG_COMPAT
331 	.compat_setsockopt = sock_no_setsockopt,
332 	.compat_getsockopt = sock_no_getsockopt,
333 #endif
334 	.sendmsg	= pn_socket_sendmsg,
335 	.recvmsg	= sock_common_recvmsg,
336 	.mmap		= sock_no_mmap,
337 	.sendpage	= sock_no_sendpage,
338 };
339 
340 const struct proto_ops phonet_stream_ops = {
341 	.family		= AF_PHONET,
342 	.owner		= THIS_MODULE,
343 	.release	= pn_socket_release,
344 	.bind		= pn_socket_bind,
345 	.connect	= sock_no_connect,
346 	.socketpair	= sock_no_socketpair,
347 	.accept		= pn_socket_accept,
348 	.getname	= pn_socket_getname,
349 	.poll		= pn_socket_poll,
350 	.ioctl		= pn_socket_ioctl,
351 	.listen		= pn_socket_listen,
352 	.shutdown	= sock_no_shutdown,
353 	.setsockopt	= sock_common_setsockopt,
354 	.getsockopt	= sock_common_getsockopt,
355 #ifdef CONFIG_COMPAT
356 	.compat_setsockopt = compat_sock_common_setsockopt,
357 	.compat_getsockopt = compat_sock_common_getsockopt,
358 #endif
359 	.sendmsg	= pn_socket_sendmsg,
360 	.recvmsg	= sock_common_recvmsg,
361 	.mmap		= sock_no_mmap,
362 	.sendpage	= sock_no_sendpage,
363 };
364 EXPORT_SYMBOL(phonet_stream_ops);
365 
366 /* allocate port for a socket */
367 int pn_sock_get_port(struct sock *sk, unsigned short sport)
368 {
369 	static int port_cur;
370 	struct net *net = sock_net(sk);
371 	struct pn_sock *pn = pn_sk(sk);
372 	struct sockaddr_pn try_sa;
373 	struct sock *tmpsk;
374 
375 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
376 	try_sa.spn_family = AF_PHONET;
377 	WARN_ON(!mutex_is_locked(&port_mutex));
378 	if (!sport) {
379 		/* search free port */
380 		int port, pmin, pmax;
381 
382 		phonet_get_local_port_range(&pmin, &pmax);
383 		for (port = pmin; port <= pmax; port++) {
384 			port_cur++;
385 			if (port_cur < pmin || port_cur > pmax)
386 				port_cur = pmin;
387 
388 			pn_sockaddr_set_port(&try_sa, port_cur);
389 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
390 			if (tmpsk == NULL) {
391 				sport = port_cur;
392 				goto found;
393 			} else
394 				sock_put(tmpsk);
395 		}
396 	} else {
397 		/* try to find specific port */
398 		pn_sockaddr_set_port(&try_sa, sport);
399 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
400 		if (tmpsk == NULL)
401 			/* No sock there! We can use that port... */
402 			goto found;
403 		else
404 			sock_put(tmpsk);
405 	}
406 	/* the port must be in use already */
407 	return -EADDRINUSE;
408 
409 found:
410 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
411 	return 0;
412 }
413 EXPORT_SYMBOL(pn_sock_get_port);
414 
415 #ifdef CONFIG_PROC_FS
416 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
417 {
418 	struct net *net = seq_file_net(seq);
419 	struct hlist_node *node;
420 	struct sock *sknode;
421 
422 	sk_for_each(sknode, node, &pnsocks.hlist) {
423 		if (!net_eq(net, sock_net(sknode)))
424 			continue;
425 		if (!pos)
426 			return sknode;
427 		pos--;
428 	}
429 	return NULL;
430 }
431 
432 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
433 {
434 	struct net *net = seq_file_net(seq);
435 
436 	do
437 		sk = sk_next(sk);
438 	while (sk && !net_eq(net, sock_net(sk)));
439 
440 	return sk;
441 }
442 
443 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
444 	__acquires(pnsocks.lock)
445 {
446 	spin_lock_bh(&pnsocks.lock);
447 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
448 }
449 
450 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
451 {
452 	struct sock *sk;
453 
454 	if (v == SEQ_START_TOKEN)
455 		sk = pn_sock_get_idx(seq, 0);
456 	else
457 		sk = pn_sock_get_next(seq, v);
458 	(*pos)++;
459 	return sk;
460 }
461 
462 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
463 	__releases(pnsocks.lock)
464 {
465 	spin_unlock_bh(&pnsocks.lock);
466 }
467 
468 static int pn_sock_seq_show(struct seq_file *seq, void *v)
469 {
470 	int len;
471 
472 	if (v == SEQ_START_TOKEN)
473 		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
474 			"  uid inode ref pointer drops", &len);
475 	else {
476 		struct sock *sk = v;
477 		struct pn_sock *pn = pn_sk(sk);
478 
479 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
480 			"%d %p %d%n",
481 			sk->sk_protocol, pn->sobject, 0, pn->resource,
482 			sk->sk_state,
483 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
484 			sock_i_uid(sk), sock_i_ino(sk),
485 			atomic_read(&sk->sk_refcnt), sk,
486 			atomic_read(&sk->sk_drops), &len);
487 	}
488 	seq_printf(seq, "%*s\n", 127 - len, "");
489 	return 0;
490 }
491 
492 static const struct seq_operations pn_sock_seq_ops = {
493 	.start = pn_sock_seq_start,
494 	.next = pn_sock_seq_next,
495 	.stop = pn_sock_seq_stop,
496 	.show = pn_sock_seq_show,
497 };
498 
499 static int pn_sock_open(struct inode *inode, struct file *file)
500 {
501 	return seq_open_net(inode, file, &pn_sock_seq_ops,
502 				sizeof(struct seq_net_private));
503 }
504 
505 const struct file_operations pn_sock_seq_fops = {
506 	.owner = THIS_MODULE,
507 	.open = pn_sock_open,
508 	.read = seq_read,
509 	.llseek = seq_lseek,
510 	.release = seq_release_net,
511 };
512 #endif
513