svc.c revision de713b57947a7a1b9cc605c0296ee14065cd86b6
1/* net/atm/svc.c - ATM SVC sockets */
2
3/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4
5#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
6
7#include <linux/string.h>
8#include <linux/net.h>		/* struct socket, struct proto_ops */
9#include <linux/errno.h>	/* error codes */
10#include <linux/kernel.h>	/* printk */
11#include <linux/skbuff.h>
12#include <linux/wait.h>
13#include <linux/sched.h>	/* jiffies and HZ */
14#include <linux/fcntl.h>	/* O_NONBLOCK */
15#include <linux/init.h>
16#include <linux/atm.h>		/* ATM stuff */
17#include <linux/atmsap.h>
18#include <linux/atmsvc.h>
19#include <linux/atmdev.h>
20#include <linux/bitops.h>
21#include <net/sock.h>		/* for sock_no_* */
22#include <linux/uaccess.h>
23#include <linux/export.h>
24
25#include "resources.h"
26#include "common.h"		/* common for PVCs and SVCs */
27#include "signaling.h"
28#include "addr.h"
29
30static int svc_create(struct net *net, struct socket *sock, int protocol,
31		      int kern);
32
33/*
34 * Note: since all this is still nicely synchronized with the signaling demon,
35 *       there's no need to protect sleep loops with clis. If signaling is
36 *       moved into the kernel, that would change.
37 */
38
39
40static int svc_shutdown(struct socket *sock, int how)
41{
42	return 0;
43}
44
45static void svc_disconnect(struct atm_vcc *vcc)
46{
47	DEFINE_WAIT(wait);
48	struct sk_buff *skb;
49	struct sock *sk = sk_atm(vcc);
50
51	pr_debug("%p\n", vcc);
52	if (test_bit(ATM_VF_REGIS, &vcc->flags)) {
53		sigd_enq(vcc, as_close, NULL, NULL, NULL);
54		for (;;) {
55			prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
56			if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd)
57				break;
58			schedule();
59		}
60		finish_wait(sk_sleep(sk), &wait);
61	}
62	/* beware - socket is still in use by atmsigd until the last
63	   as_indicate has been answered */
64	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
65		atm_return(vcc, skb->truesize);
66		pr_debug("LISTEN REL\n");
67		sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0);
68		dev_kfree_skb(skb);
69	}
70	clear_bit(ATM_VF_REGIS, &vcc->flags);
71	/* ... may retry later */
72}
73
74static int svc_release(struct socket *sock)
75{
76	struct sock *sk = sock->sk;
77	struct atm_vcc *vcc;
78
79	if (sk) {
80		vcc = ATM_SD(sock);
81		pr_debug("%p\n", vcc);
82		clear_bit(ATM_VF_READY, &vcc->flags);
83		/*
84		 * VCC pointer is used as a reference,
85		 * so we must not free it (thereby subjecting it to re-use)
86		 * before all pending connections are closed
87		 */
88		svc_disconnect(vcc);
89		vcc_release(sock);
90	}
91	return 0;
92}
93
94static int svc_bind(struct socket *sock, struct sockaddr *sockaddr,
95		    int sockaddr_len)
96{
97	DEFINE_WAIT(wait);
98	struct sock *sk = sock->sk;
99	struct sockaddr_atmsvc *addr;
100	struct atm_vcc *vcc;
101	int error;
102
103	if (sockaddr_len != sizeof(struct sockaddr_atmsvc))
104		return -EINVAL;
105	lock_sock(sk);
106	if (sock->state == SS_CONNECTED) {
107		error = -EISCONN;
108		goto out;
109	}
110	if (sock->state != SS_UNCONNECTED) {
111		error = -EINVAL;
112		goto out;
113	}
114	vcc = ATM_SD(sock);
115	addr = (struct sockaddr_atmsvc *) sockaddr;
116	if (addr->sas_family != AF_ATMSVC) {
117		error = -EAFNOSUPPORT;
118		goto out;
119	}
120	clear_bit(ATM_VF_BOUND, &vcc->flags);
121	    /* failing rebind will kill old binding */
122	/* @@@ check memory (de)allocation on rebind */
123	if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
124		error = -EBADFD;
125		goto out;
126	}
127	vcc->local = *addr;
128	set_bit(ATM_VF_WAITING, &vcc->flags);
129	sigd_enq(vcc, as_bind, NULL, NULL, &vcc->local);
130	for (;;) {
131		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
132		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
133			break;
134		schedule();
135	}
136	finish_wait(sk_sleep(sk), &wait);
137	clear_bit(ATM_VF_REGIS, &vcc->flags); /* doesn't count */
138	if (!sigd) {
139		error = -EUNATCH;
140		goto out;
141	}
142	if (!sk->sk_err)
143		set_bit(ATM_VF_BOUND, &vcc->flags);
144	error = -sk->sk_err;
145out:
146	release_sock(sk);
147	return error;
148}
149
150static int svc_connect(struct socket *sock, struct sockaddr *sockaddr,
151		       int sockaddr_len, int flags)
152{
153	DEFINE_WAIT(wait);
154	struct sock *sk = sock->sk;
155	struct sockaddr_atmsvc *addr;
156	struct atm_vcc *vcc = ATM_SD(sock);
157	int error;
158
159	pr_debug("%p\n", vcc);
160	lock_sock(sk);
161	if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) {
162		error = -EINVAL;
163		goto out;
164	}
165
166	switch (sock->state) {
167	default:
168		error = -EINVAL;
169		goto out;
170	case SS_CONNECTED:
171		error = -EISCONN;
172		goto out;
173	case SS_CONNECTING:
174		if (test_bit(ATM_VF_WAITING, &vcc->flags)) {
175			error = -EALREADY;
176			goto out;
177		}
178		sock->state = SS_UNCONNECTED;
179		if (sk->sk_err) {
180			error = -sk->sk_err;
181			goto out;
182		}
183		break;
184	case SS_UNCONNECTED:
185		addr = (struct sockaddr_atmsvc *) sockaddr;
186		if (addr->sas_family != AF_ATMSVC) {
187			error = -EAFNOSUPPORT;
188			goto out;
189		}
190		if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
191			error = -EBADFD;
192			goto out;
193		}
194		if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
195		    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS) {
196			error = -EINVAL;
197			goto out;
198		}
199		if (!vcc->qos.txtp.traffic_class &&
200		    !vcc->qos.rxtp.traffic_class) {
201			error = -EINVAL;
202			goto out;
203		}
204		vcc->remote = *addr;
205		set_bit(ATM_VF_WAITING, &vcc->flags);
206		sigd_enq(vcc, as_connect, NULL, NULL, &vcc->remote);
207		if (flags & O_NONBLOCK) {
208			sock->state = SS_CONNECTING;
209			error = -EINPROGRESS;
210			goto out;
211		}
212		error = 0;
213		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
214		while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
215			schedule();
216			if (!signal_pending(current)) {
217				prepare_to_wait(sk_sleep(sk), &wait,
218						TASK_INTERRUPTIBLE);
219				continue;
220			}
221			pr_debug("*ABORT*\n");
222			/*
223			 * This is tricky:
224			 *   Kernel ---close--> Demon
225			 *   Kernel <--close--- Demon
226			 * or
227			 *   Kernel ---close--> Demon
228			 *   Kernel <--error--- Demon
229			 * or
230			 *   Kernel ---close--> Demon
231			 *   Kernel <--okay---- Demon
232			 *   Kernel <--close--- Demon
233			 */
234			sigd_enq(vcc, as_close, NULL, NULL, NULL);
235			while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
236				prepare_to_wait(sk_sleep(sk), &wait,
237						TASK_INTERRUPTIBLE);
238				schedule();
239			}
240			if (!sk->sk_err)
241				while (!test_bit(ATM_VF_RELEASED, &vcc->flags) &&
242				       sigd) {
243					prepare_to_wait(sk_sleep(sk), &wait,
244							TASK_INTERRUPTIBLE);
245					schedule();
246				}
247			clear_bit(ATM_VF_REGIS, &vcc->flags);
248			clear_bit(ATM_VF_RELEASED, &vcc->flags);
249			clear_bit(ATM_VF_CLOSE, &vcc->flags);
250			    /* we're gone now but may connect later */
251			error = -EINTR;
252			break;
253		}
254		finish_wait(sk_sleep(sk), &wait);
255		if (error)
256			goto out;
257		if (!sigd) {
258			error = -EUNATCH;
259			goto out;
260		}
261		if (sk->sk_err) {
262			error = -sk->sk_err;
263			goto out;
264		}
265	}
266
267	vcc->qos.txtp.max_pcr = SELECT_TOP_PCR(vcc->qos.txtp);
268	vcc->qos.txtp.pcr = 0;
269	vcc->qos.txtp.min_pcr = 0;
270
271	error = vcc_connect(sock, vcc->itf, vcc->vpi, vcc->vci);
272	if (!error)
273		sock->state = SS_CONNECTED;
274	else
275		(void)svc_disconnect(vcc);
276out:
277	release_sock(sk);
278	return error;
279}
280
281static int svc_listen(struct socket *sock, int backlog)
282{
283	DEFINE_WAIT(wait);
284	struct sock *sk = sock->sk;
285	struct atm_vcc *vcc = ATM_SD(sock);
286	int error;
287
288	pr_debug("%p\n", vcc);
289	lock_sock(sk);
290	/* let server handle listen on unbound sockets */
291	if (test_bit(ATM_VF_SESSION, &vcc->flags)) {
292		error = -EINVAL;
293		goto out;
294	}
295	if (test_bit(ATM_VF_LISTEN, &vcc->flags)) {
296		error = -EADDRINUSE;
297		goto out;
298	}
299	set_bit(ATM_VF_WAITING, &vcc->flags);
300	sigd_enq(vcc, as_listen, NULL, NULL, &vcc->local);
301	for (;;) {
302		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
303		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
304			break;
305		schedule();
306	}
307	finish_wait(sk_sleep(sk), &wait);
308	if (!sigd) {
309		error = -EUNATCH;
310		goto out;
311	}
312	set_bit(ATM_VF_LISTEN, &vcc->flags);
313	vcc_insert_socket(sk);
314	sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT;
315	error = -sk->sk_err;
316out:
317	release_sock(sk);
318	return error;
319}
320
321static int svc_accept(struct socket *sock, struct socket *newsock, int flags)
322{
323	struct sock *sk = sock->sk;
324	struct sk_buff *skb;
325	struct atmsvc_msg *msg;
326	struct atm_vcc *old_vcc = ATM_SD(sock);
327	struct atm_vcc *new_vcc;
328	int error;
329
330	lock_sock(sk);
331
332	error = svc_create(sock_net(sk), newsock, 0, 0);
333	if (error)
334		goto out;
335
336	new_vcc = ATM_SD(newsock);
337
338	pr_debug("%p -> %p\n", old_vcc, new_vcc);
339	while (1) {
340		DEFINE_WAIT(wait);
341
342		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
343		while (!(skb = skb_dequeue(&sk->sk_receive_queue)) &&
344		       sigd) {
345			if (test_bit(ATM_VF_RELEASED, &old_vcc->flags))
346				break;
347			if (test_bit(ATM_VF_CLOSE, &old_vcc->flags)) {
348				error = -sk->sk_err;
349				break;
350			}
351			if (flags & O_NONBLOCK) {
352				error = -EAGAIN;
353				break;
354			}
355			release_sock(sk);
356			schedule();
357			lock_sock(sk);
358			if (signal_pending(current)) {
359				error = -ERESTARTSYS;
360				break;
361			}
362			prepare_to_wait(sk_sleep(sk), &wait,
363					TASK_INTERRUPTIBLE);
364		}
365		finish_wait(sk_sleep(sk), &wait);
366		if (error)
367			goto out;
368		if (!skb) {
369			error = -EUNATCH;
370			goto out;
371		}
372		msg = (struct atmsvc_msg *)skb->data;
373		new_vcc->qos = msg->qos;
374		set_bit(ATM_VF_HASQOS, &new_vcc->flags);
375		new_vcc->remote = msg->svc;
376		new_vcc->local = msg->local;
377		new_vcc->sap = msg->sap;
378		error = vcc_connect(newsock, msg->pvc.sap_addr.itf,
379				    msg->pvc.sap_addr.vpi,
380				    msg->pvc.sap_addr.vci);
381		dev_kfree_skb(skb);
382		sk->sk_ack_backlog--;
383		if (error) {
384			sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL,
385				  &old_vcc->qos, error);
386			error = error == -EAGAIN ? -EBUSY : error;
387			goto out;
388		}
389		/* wait should be short, so we ignore the non-blocking flag */
390		set_bit(ATM_VF_WAITING, &new_vcc->flags);
391		sigd_enq(new_vcc, as_accept, old_vcc, NULL, NULL);
392		for (;;) {
393			prepare_to_wait(sk_sleep(sk_atm(new_vcc)), &wait,
394					TASK_UNINTERRUPTIBLE);
395			if (!test_bit(ATM_VF_WAITING, &new_vcc->flags) || !sigd)
396				break;
397			release_sock(sk);
398			schedule();
399			lock_sock(sk);
400		}
401		finish_wait(sk_sleep(sk_atm(new_vcc)), &wait);
402		if (!sigd) {
403			error = -EUNATCH;
404			goto out;
405		}
406		if (!sk_atm(new_vcc)->sk_err)
407			break;
408		if (sk_atm(new_vcc)->sk_err != ERESTARTSYS) {
409			error = -sk_atm(new_vcc)->sk_err;
410			goto out;
411		}
412	}
413	newsock->state = SS_CONNECTED;
414out:
415	release_sock(sk);
416	return error;
417}
418
419static int svc_getname(struct socket *sock, struct sockaddr *sockaddr,
420		       int *sockaddr_len, int peer)
421{
422	struct sockaddr_atmsvc *addr;
423
424	*sockaddr_len = sizeof(struct sockaddr_atmsvc);
425	addr = (struct sockaddr_atmsvc *) sockaddr;
426	memcpy(addr, peer ? &ATM_SD(sock)->remote : &ATM_SD(sock)->local,
427	       sizeof(struct sockaddr_atmsvc));
428	return 0;
429}
430
431int svc_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)
432{
433	struct sock *sk = sk_atm(vcc);
434	DEFINE_WAIT(wait);
435
436	set_bit(ATM_VF_WAITING, &vcc->flags);
437	sigd_enq2(vcc, as_modify, NULL, NULL, &vcc->local, qos, 0);
438	for (;;) {
439		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
440		if (!test_bit(ATM_VF_WAITING, &vcc->flags) ||
441		    test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) {
442			break;
443		}
444		schedule();
445	}
446	finish_wait(sk_sleep(sk), &wait);
447	if (!sigd)
448		return -EUNATCH;
449	return -sk->sk_err;
450}
451
452static int svc_setsockopt(struct socket *sock, int level, int optname,
453			  char __user *optval, unsigned int optlen)
454{
455	struct sock *sk = sock->sk;
456	struct atm_vcc *vcc = ATM_SD(sock);
457	int value, error = 0;
458
459	lock_sock(sk);
460	switch (optname) {
461	case SO_ATMSAP:
462		if (level != SOL_ATM || optlen != sizeof(struct atm_sap)) {
463			error = -EINVAL;
464			goto out;
465		}
466		if (copy_from_user(&vcc->sap, optval, optlen)) {
467			error = -EFAULT;
468			goto out;
469		}
470		set_bit(ATM_VF_HASSAP, &vcc->flags);
471		break;
472	case SO_MULTIPOINT:
473		if (level != SOL_ATM || optlen != sizeof(int)) {
474			error = -EINVAL;
475			goto out;
476		}
477		if (get_user(value, (int __user *)optval)) {
478			error = -EFAULT;
479			goto out;
480		}
481		if (value == 1)
482			set_bit(ATM_VF_SESSION, &vcc->flags);
483		else if (value == 0)
484			clear_bit(ATM_VF_SESSION, &vcc->flags);
485		else
486			error = -EINVAL;
487		break;
488	default:
489		error = vcc_setsockopt(sock, level, optname, optval, optlen);
490	}
491
492out:
493	release_sock(sk);
494	return error;
495}
496
497static int svc_getsockopt(struct socket *sock, int level, int optname,
498			  char __user *optval, int __user *optlen)
499{
500	struct sock *sk = sock->sk;
501	int error = 0, len;
502
503	lock_sock(sk);
504	if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) {
505		error = vcc_getsockopt(sock, level, optname, optval, optlen);
506		goto out;
507	}
508	if (get_user(len, optlen)) {
509		error = -EFAULT;
510		goto out;
511	}
512	if (len != sizeof(struct atm_sap)) {
513		error = -EINVAL;
514		goto out;
515	}
516	if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) {
517		error = -EFAULT;
518		goto out;
519	}
520out:
521	release_sock(sk);
522	return error;
523}
524
525static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr,
526			int sockaddr_len, int flags)
527{
528	DEFINE_WAIT(wait);
529	struct sock *sk = sock->sk;
530	struct atm_vcc *vcc = ATM_SD(sock);
531	int error;
532
533	lock_sock(sk);
534	set_bit(ATM_VF_WAITING, &vcc->flags);
535	sigd_enq(vcc, as_addparty, NULL, NULL,
536		 (struct sockaddr_atmsvc *) sockaddr);
537	if (flags & O_NONBLOCK) {
538		error = -EINPROGRESS;
539		goto out;
540	}
541	pr_debug("added wait queue\n");
542	for (;;) {
543		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
544		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
545			break;
546		schedule();
547	}
548	finish_wait(sk_sleep(sk), &wait);
549	error = xchg(&sk->sk_err_soft, 0);
550out:
551	release_sock(sk);
552	return error;
553}
554
555static int svc_dropparty(struct socket *sock, int ep_ref)
556{
557	DEFINE_WAIT(wait);
558	struct sock *sk = sock->sk;
559	struct atm_vcc *vcc = ATM_SD(sock);
560	int error;
561
562	lock_sock(sk);
563	set_bit(ATM_VF_WAITING, &vcc->flags);
564	sigd_enq2(vcc, as_dropparty, NULL, NULL, NULL, NULL, ep_ref);
565	for (;;) {
566		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
567		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
568			break;
569		schedule();
570	}
571	finish_wait(sk_sleep(sk), &wait);
572	if (!sigd) {
573		error = -EUNATCH;
574		goto out;
575	}
576	error = xchg(&sk->sk_err_soft, 0);
577out:
578	release_sock(sk);
579	return error;
580}
581
582static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
583{
584	int error, ep_ref;
585	struct sockaddr_atmsvc sa;
586	struct atm_vcc *vcc = ATM_SD(sock);
587
588	switch (cmd) {
589	case ATM_ADDPARTY:
590		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
591			return -EINVAL;
592		if (copy_from_user(&sa, (void __user *) arg, sizeof(sa)))
593			return -EFAULT;
594		error = svc_addparty(sock, (struct sockaddr *)&sa, sizeof(sa),
595				     0);
596		break;
597	case ATM_DROPPARTY:
598		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
599			return -EINVAL;
600		if (copy_from_user(&ep_ref, (void __user *) arg, sizeof(int)))
601			return -EFAULT;
602		error = svc_dropparty(sock, ep_ref);
603		break;
604	default:
605		error = vcc_ioctl(sock, cmd, arg);
606	}
607
608	return error;
609}
610
611#ifdef CONFIG_COMPAT
612static int svc_compat_ioctl(struct socket *sock, unsigned int cmd,
613			    unsigned long arg)
614{
615	/* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf.
616	   But actually it takes a struct sockaddr_atmsvc, which doesn't need
617	   compat handling. So all we have to do is fix up cmd... */
618	if (cmd == COMPAT_ATM_ADDPARTY)
619		cmd = ATM_ADDPARTY;
620
621	if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY)
622		return svc_ioctl(sock, cmd, arg);
623	else
624		return vcc_compat_ioctl(sock, cmd, arg);
625}
626#endif /* CONFIG_COMPAT */
627
628static const struct proto_ops svc_proto_ops = {
629	.family =	PF_ATMSVC,
630	.owner =	THIS_MODULE,
631
632	.release =	svc_release,
633	.bind =		svc_bind,
634	.connect =	svc_connect,
635	.socketpair =	sock_no_socketpair,
636	.accept =	svc_accept,
637	.getname =	svc_getname,
638	.poll =		vcc_poll,
639	.ioctl =	svc_ioctl,
640#ifdef CONFIG_COMPAT
641	.compat_ioctl =	svc_compat_ioctl,
642#endif
643	.listen =	svc_listen,
644	.shutdown =	svc_shutdown,
645	.setsockopt =	svc_setsockopt,
646	.getsockopt =	svc_getsockopt,
647	.sendmsg =	vcc_sendmsg,
648	.recvmsg =	vcc_recvmsg,
649	.mmap =		sock_no_mmap,
650	.sendpage =	sock_no_sendpage,
651};
652
653
654static int svc_create(struct net *net, struct socket *sock, int protocol,
655		      int kern)
656{
657	int error;
658
659	if (!net_eq(net, &init_net))
660		return -EAFNOSUPPORT;
661
662	sock->ops = &svc_proto_ops;
663	error = vcc_create(net, sock, protocol, AF_ATMSVC);
664	if (error)
665		return error;
666	ATM_SD(sock)->local.sas_family = AF_ATMSVC;
667	ATM_SD(sock)->remote.sas_family = AF_ATMSVC;
668	return 0;
669}
670
671static const struct net_proto_family svc_family_ops = {
672	.family = PF_ATMSVC,
673	.create = svc_create,
674	.owner = THIS_MODULE,
675};
676
677
678/*
679 *	Initialize the ATM SVC protocol family
680 */
681
682int __init atmsvc_init(void)
683{
684	return sock_register(&svc_family_ops);
685}
686
687void atmsvc_exit(void)
688{
689	sock_unregister(PF_ATMSVC);
690}
691