xref: /openbmc/linux/net/phonet/socket.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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 #define PN_HASHSIZE	16
49 #define PN_HASHMASK	(PN_HASHSIZE-1)
50 
51 
52 static struct  {
53 	struct hlist_head hlist[PN_HASHSIZE];
54 	spinlock_t lock;
55 } pnsocks;
56 
57 void __init pn_sock_init(void)
58 {
59 	unsigned i;
60 
61 	for (i = 0; i < PN_HASHSIZE; i++)
62 		INIT_HLIST_HEAD(pnsocks.hlist + i);
63 	spin_lock_init(&pnsocks.lock);
64 }
65 
66 static struct hlist_head *pn_hash_list(u16 obj)
67 {
68 	return pnsocks.hlist + (obj & PN_HASHMASK);
69 }
70 
71 /*
72  * Find address based on socket address, match only certain fields.
73  * Also grab sock if it was found. Remember to sock_put it later.
74  */
75 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
76 {
77 	struct hlist_node *node;
78 	struct sock *sknode;
79 	struct sock *rval = NULL;
80 	u16 obj = pn_sockaddr_get_object(spn);
81 	u8 res = spn->spn_resource;
82 	struct hlist_head *hlist = pn_hash_list(obj);
83 
84 	spin_lock_bh(&pnsocks.lock);
85 
86 	sk_for_each(sknode, node, hlist) {
87 		struct pn_sock *pn = pn_sk(sknode);
88 		BUG_ON(!pn->sobject); /* unbound socket */
89 
90 		if (!net_eq(sock_net(sknode), net))
91 			continue;
92 		if (pn_port(obj)) {
93 			/* Look up socket by port */
94 			if (pn_port(pn->sobject) != pn_port(obj))
95 				continue;
96 		} else {
97 			/* If port is zero, look up by resource */
98 			if (pn->resource != res)
99 				continue;
100 		}
101 		if (pn_addr(pn->sobject) &&
102 		    pn_addr(pn->sobject) != pn_addr(obj))
103 			continue;
104 
105 		rval = sknode;
106 		sock_hold(sknode);
107 		break;
108 	}
109 
110 	spin_unlock_bh(&pnsocks.lock);
111 
112 	return rval;
113 }
114 
115 /* Deliver a broadcast packet (only in bottom-half) */
116 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
117 {
118 	struct hlist_head *hlist = pnsocks.hlist;
119 	unsigned h;
120 
121 	spin_lock(&pnsocks.lock);
122 	for (h = 0; h < PN_HASHSIZE; h++) {
123 		struct hlist_node *node;
124 		struct sock *sknode;
125 
126 		sk_for_each(sknode, node, hlist) {
127 			struct sk_buff *clone;
128 
129 			if (!net_eq(sock_net(sknode), net))
130 				continue;
131 			if (!sock_flag(sknode, SOCK_BROADCAST))
132 				continue;
133 
134 			clone = skb_clone(skb, GFP_ATOMIC);
135 			if (clone) {
136 				sock_hold(sknode);
137 				sk_receive_skb(sknode, clone, 0);
138 			}
139 		}
140 		hlist++;
141 	}
142 	spin_unlock(&pnsocks.lock);
143 }
144 
145 void pn_sock_hash(struct sock *sk)
146 {
147 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
148 
149 	spin_lock_bh(&pnsocks.lock);
150 	sk_add_node(sk, hlist);
151 	spin_unlock_bh(&pnsocks.lock);
152 }
153 EXPORT_SYMBOL(pn_sock_hash);
154 
155 void pn_sock_unhash(struct sock *sk)
156 {
157 	spin_lock_bh(&pnsocks.lock);
158 	sk_del_node_init(sk);
159 	spin_unlock_bh(&pnsocks.lock);
160 }
161 EXPORT_SYMBOL(pn_sock_unhash);
162 
163 static DEFINE_MUTEX(port_mutex);
164 
165 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
166 {
167 	struct sock *sk = sock->sk;
168 	struct pn_sock *pn = pn_sk(sk);
169 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
170 	int err;
171 	u16 handle;
172 	u8 saddr;
173 
174 	if (sk->sk_prot->bind)
175 		return sk->sk_prot->bind(sk, addr, len);
176 
177 	if (len < sizeof(struct sockaddr_pn))
178 		return -EINVAL;
179 	if (spn->spn_family != AF_PHONET)
180 		return -EAFNOSUPPORT;
181 
182 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
183 	saddr = pn_addr(handle);
184 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
185 		return -EADDRNOTAVAIL;
186 
187 	lock_sock(sk);
188 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
189 		err = -EINVAL; /* attempt to rebind */
190 		goto out;
191 	}
192 	WARN_ON(sk_hashed(sk));
193 	mutex_lock(&port_mutex);
194 	err = sk->sk_prot->get_port(sk, pn_port(handle));
195 	if (err)
196 		goto out_port;
197 
198 	/* get_port() sets the port, bind() sets the address if applicable */
199 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
200 	pn->resource = spn->spn_resource;
201 
202 	/* Enable RX on the socket */
203 	sk->sk_prot->hash(sk);
204 out_port:
205 	mutex_unlock(&port_mutex);
206 out:
207 	release_sock(sk);
208 	return err;
209 }
210 
211 static int pn_socket_autobind(struct socket *sock)
212 {
213 	struct sockaddr_pn sa;
214 	int err;
215 
216 	memset(&sa, 0, sizeof(sa));
217 	sa.spn_family = AF_PHONET;
218 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
219 				sizeof(struct sockaddr_pn));
220 	if (err != -EINVAL)
221 		return err;
222 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
223 	return 0; /* socket was already bound */
224 }
225 
226 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
227 				int flags)
228 {
229 	struct sock *sk = sock->sk;
230 	struct sock *newsk;
231 	int err;
232 
233 	newsk = sk->sk_prot->accept(sk, flags, &err);
234 	if (!newsk)
235 		return err;
236 
237 	lock_sock(newsk);
238 	sock_graft(newsk, newsock);
239 	newsock->state = SS_CONNECTED;
240 	release_sock(newsk);
241 	return 0;
242 }
243 
244 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
245 				int *sockaddr_len, int peer)
246 {
247 	struct sock *sk = sock->sk;
248 	struct pn_sock *pn = pn_sk(sk);
249 
250 	memset(addr, 0, sizeof(struct sockaddr_pn));
251 	addr->sa_family = AF_PHONET;
252 	if (!peer) /* Race with bind() here is userland's problem. */
253 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
254 					pn->sobject);
255 
256 	*sockaddr_len = sizeof(struct sockaddr_pn);
257 	return 0;
258 }
259 
260 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
261 					poll_table *wait)
262 {
263 	struct sock *sk = sock->sk;
264 	struct pep_sock *pn = pep_sk(sk);
265 	unsigned int mask = 0;
266 
267 	poll_wait(file, &sock->wait, wait);
268 
269 	switch (sk->sk_state) {
270 	case TCP_LISTEN:
271 		return hlist_empty(&pn->ackq) ? 0 : POLLIN;
272 	case TCP_CLOSE:
273 		return POLLERR;
274 	}
275 
276 	if (!skb_queue_empty(&sk->sk_receive_queue))
277 		mask |= POLLIN | POLLRDNORM;
278 	if (!skb_queue_empty(&pn->ctrlreq_queue))
279 		mask |= POLLPRI;
280 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
281 		return POLLHUP;
282 
283 	if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
284 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
285 
286 	return mask;
287 }
288 
289 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
290 				unsigned long arg)
291 {
292 	struct sock *sk = sock->sk;
293 	struct pn_sock *pn = pn_sk(sk);
294 
295 	if (cmd == SIOCPNGETOBJECT) {
296 		struct net_device *dev;
297 		u16 handle;
298 		u8 saddr;
299 
300 		if (get_user(handle, (__u16 __user *)arg))
301 			return -EFAULT;
302 
303 		lock_sock(sk);
304 		if (sk->sk_bound_dev_if)
305 			dev = dev_get_by_index(sock_net(sk),
306 						sk->sk_bound_dev_if);
307 		else
308 			dev = phonet_device_get(sock_net(sk));
309 		if (dev && (dev->flags & IFF_UP))
310 			saddr = phonet_address_get(dev, pn_addr(handle));
311 		else
312 			saddr = PN_NO_ADDR;
313 		release_sock(sk);
314 
315 		if (dev)
316 			dev_put(dev);
317 		if (saddr == PN_NO_ADDR)
318 			return -EHOSTUNREACH;
319 
320 		handle = pn_object(saddr, pn_port(pn->sobject));
321 		return put_user(handle, (__u16 __user *)arg);
322 	}
323 
324 	return sk->sk_prot->ioctl(sk, cmd, arg);
325 }
326 
327 static int pn_socket_listen(struct socket *sock, int backlog)
328 {
329 	struct sock *sk = sock->sk;
330 	int err = 0;
331 
332 	if (sock->state != SS_UNCONNECTED)
333 		return -EINVAL;
334 	if (pn_socket_autobind(sock))
335 		return -ENOBUFS;
336 
337 	lock_sock(sk);
338 	if (sk->sk_state != TCP_CLOSE) {
339 		err = -EINVAL;
340 		goto out;
341 	}
342 
343 	sk->sk_state = TCP_LISTEN;
344 	sk->sk_ack_backlog = 0;
345 	sk->sk_max_ack_backlog = backlog;
346 out:
347 	release_sock(sk);
348 	return err;
349 }
350 
351 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
352 				struct msghdr *m, size_t total_len)
353 {
354 	struct sock *sk = sock->sk;
355 
356 	if (pn_socket_autobind(sock))
357 		return -EAGAIN;
358 
359 	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
360 }
361 
362 const struct proto_ops phonet_dgram_ops = {
363 	.family		= AF_PHONET,
364 	.owner		= THIS_MODULE,
365 	.release	= pn_socket_release,
366 	.bind		= pn_socket_bind,
367 	.connect	= sock_no_connect,
368 	.socketpair	= sock_no_socketpair,
369 	.accept		= sock_no_accept,
370 	.getname	= pn_socket_getname,
371 	.poll		= datagram_poll,
372 	.ioctl		= pn_socket_ioctl,
373 	.listen		= sock_no_listen,
374 	.shutdown	= sock_no_shutdown,
375 	.setsockopt	= sock_no_setsockopt,
376 	.getsockopt	= sock_no_getsockopt,
377 #ifdef CONFIG_COMPAT
378 	.compat_setsockopt = sock_no_setsockopt,
379 	.compat_getsockopt = sock_no_getsockopt,
380 #endif
381 	.sendmsg	= pn_socket_sendmsg,
382 	.recvmsg	= sock_common_recvmsg,
383 	.mmap		= sock_no_mmap,
384 	.sendpage	= sock_no_sendpage,
385 };
386 
387 const struct proto_ops phonet_stream_ops = {
388 	.family		= AF_PHONET,
389 	.owner		= THIS_MODULE,
390 	.release	= pn_socket_release,
391 	.bind		= pn_socket_bind,
392 	.connect	= sock_no_connect,
393 	.socketpair	= sock_no_socketpair,
394 	.accept		= pn_socket_accept,
395 	.getname	= pn_socket_getname,
396 	.poll		= pn_socket_poll,
397 	.ioctl		= pn_socket_ioctl,
398 	.listen		= pn_socket_listen,
399 	.shutdown	= sock_no_shutdown,
400 	.setsockopt	= sock_common_setsockopt,
401 	.getsockopt	= sock_common_getsockopt,
402 #ifdef CONFIG_COMPAT
403 	.compat_setsockopt = compat_sock_common_setsockopt,
404 	.compat_getsockopt = compat_sock_common_getsockopt,
405 #endif
406 	.sendmsg	= pn_socket_sendmsg,
407 	.recvmsg	= sock_common_recvmsg,
408 	.mmap		= sock_no_mmap,
409 	.sendpage	= sock_no_sendpage,
410 };
411 EXPORT_SYMBOL(phonet_stream_ops);
412 
413 /* allocate port for a socket */
414 int pn_sock_get_port(struct sock *sk, unsigned short sport)
415 {
416 	static int port_cur;
417 	struct net *net = sock_net(sk);
418 	struct pn_sock *pn = pn_sk(sk);
419 	struct sockaddr_pn try_sa;
420 	struct sock *tmpsk;
421 
422 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
423 	try_sa.spn_family = AF_PHONET;
424 	WARN_ON(!mutex_is_locked(&port_mutex));
425 	if (!sport) {
426 		/* search free port */
427 		int port, pmin, pmax;
428 
429 		phonet_get_local_port_range(&pmin, &pmax);
430 		for (port = pmin; port <= pmax; port++) {
431 			port_cur++;
432 			if (port_cur < pmin || port_cur > pmax)
433 				port_cur = pmin;
434 
435 			pn_sockaddr_set_port(&try_sa, port_cur);
436 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
437 			if (tmpsk == NULL) {
438 				sport = port_cur;
439 				goto found;
440 			} else
441 				sock_put(tmpsk);
442 		}
443 	} else {
444 		/* try to find specific port */
445 		pn_sockaddr_set_port(&try_sa, sport);
446 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
447 		if (tmpsk == NULL)
448 			/* No sock there! We can use that port... */
449 			goto found;
450 		else
451 			sock_put(tmpsk);
452 	}
453 	/* the port must be in use already */
454 	return -EADDRINUSE;
455 
456 found:
457 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
458 	return 0;
459 }
460 EXPORT_SYMBOL(pn_sock_get_port);
461 
462 #ifdef CONFIG_PROC_FS
463 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
464 {
465 	struct net *net = seq_file_net(seq);
466 	struct hlist_head *hlist = pnsocks.hlist;
467 	struct hlist_node *node;
468 	struct sock *sknode;
469 	unsigned h;
470 
471 	for (h = 0; h < PN_HASHSIZE; h++) {
472 		sk_for_each(sknode, node, hlist) {
473 			if (!net_eq(net, sock_net(sknode)))
474 				continue;
475 			if (!pos)
476 				return sknode;
477 			pos--;
478 		}
479 		hlist++;
480 	}
481 	return NULL;
482 }
483 
484 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
485 {
486 	struct net *net = seq_file_net(seq);
487 
488 	do
489 		sk = sk_next(sk);
490 	while (sk && !net_eq(net, sock_net(sk)));
491 
492 	return sk;
493 }
494 
495 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
496 	__acquires(pnsocks.lock)
497 {
498 	spin_lock_bh(&pnsocks.lock);
499 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
500 }
501 
502 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
503 {
504 	struct sock *sk;
505 
506 	if (v == SEQ_START_TOKEN)
507 		sk = pn_sock_get_idx(seq, 0);
508 	else
509 		sk = pn_sock_get_next(seq, v);
510 	(*pos)++;
511 	return sk;
512 }
513 
514 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
515 	__releases(pnsocks.lock)
516 {
517 	spin_unlock_bh(&pnsocks.lock);
518 }
519 
520 static int pn_sock_seq_show(struct seq_file *seq, void *v)
521 {
522 	int len;
523 
524 	if (v == SEQ_START_TOKEN)
525 		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
526 			"  uid inode ref pointer drops", &len);
527 	else {
528 		struct sock *sk = v;
529 		struct pn_sock *pn = pn_sk(sk);
530 
531 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
532 			"%d %p %d%n",
533 			sk->sk_protocol, pn->sobject, 0, pn->resource,
534 			sk->sk_state,
535 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
536 			sock_i_uid(sk), sock_i_ino(sk),
537 			atomic_read(&sk->sk_refcnt), sk,
538 			atomic_read(&sk->sk_drops), &len);
539 	}
540 	seq_printf(seq, "%*s\n", 127 - len, "");
541 	return 0;
542 }
543 
544 static const struct seq_operations pn_sock_seq_ops = {
545 	.start = pn_sock_seq_start,
546 	.next = pn_sock_seq_next,
547 	.stop = pn_sock_seq_stop,
548 	.show = pn_sock_seq_show,
549 };
550 
551 static int pn_sock_open(struct inode *inode, struct file *file)
552 {
553 	return seq_open_net(inode, file, &pn_sock_seq_ops,
554 				sizeof(struct seq_net_private));
555 }
556 
557 const struct file_operations pn_sock_seq_fops = {
558 	.owner = THIS_MODULE,
559 	.open = pn_sock_open,
560 	.read = seq_read,
561 	.llseek = seq_lseek,
562 	.release = seq_release_net,
563 };
564 #endif
565