1// SPDX-License-Identifier: GPL-2.0
  2/* net/atm/svc.c - ATM SVC sockets */
  3
  4/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  7
  8#include <linux/string.h>
  9#include <linux/net.h>		/* struct socket, struct proto_ops */
 10#include <linux/errno.h>	/* error codes */
 11#include <linux/kernel.h>	/* printk */
 12#include <linux/skbuff.h>
 13#include <linux/wait.h>
 14#include <linux/sched/signal.h>
 15#include <linux/fcntl.h>	/* O_NONBLOCK */
 16#include <linux/init.h>
 17#include <linux/atm.h>		/* ATM stuff */
 18#include <linux/atmsap.h>
 19#include <linux/atmsvc.h>
 20#include <linux/atmdev.h>
 21#include <linux/bitops.h>
 22#include <net/sock.h>		/* for sock_no_* */
 23#include <linux/uaccess.h>
 24#include <linux/export.h>
 25
 26#include "resources.h"
 27#include "common.h"		/* common for PVCs and SVCs */
 28#include "signaling.h"
 29#include "addr.h"
 30
 31static int svc_create(struct net *net, struct socket *sock, int protocol,
 32		      int kern);
 33
 34/*
 35 * Note: since all this is still nicely synchronized with the signaling demon,
 36 *       there's no need to protect sleep loops with clis. If signaling is
 37 *       moved into the kernel, that would change.
 38 */
 39
 40
 41static int svc_shutdown(struct socket *sock, int how)
 42{
 43	return 0;
 44}
 45
 46static void svc_disconnect(struct atm_vcc *vcc)
 47{
 48	DEFINE_WAIT(wait);
 49	struct sk_buff *skb;
 50	struct sock *sk = sk_atm(vcc);
 51
 52	pr_debug("%p\n", vcc);
 53	if (test_bit(ATM_VF_REGIS, &vcc->flags)) {
 54		sigd_enq(vcc, as_close, NULL, NULL, NULL);
 55		for (;;) {
 56			prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
 57			if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd)
 58				break;
 59			schedule();
 60		}
 61		finish_wait(sk_sleep(sk), &wait);
 62	}
 63	/* beware - socket is still in use by atmsigd until the last
 64	   as_indicate has been answered */
 65	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 66		atm_return(vcc, skb->truesize);
 67		pr_debug("LISTEN REL\n");
 68		sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0);
 69		dev_kfree_skb(skb);
 70	}
 71	clear_bit(ATM_VF_REGIS, &vcc->flags);
 72	/* ... may retry later */
 73}
 74
 75static int svc_release(struct socket *sock)
 76{
 77	struct sock *sk = sock->sk;
 78	struct atm_vcc *vcc;
 79
 80	if (sk) {
 81		vcc = ATM_SD(sock);
 82		pr_debug("%p\n", vcc);
 83		clear_bit(ATM_VF_READY, &vcc->flags);
 84		/*
 85		 * VCC pointer is used as a reference,
 86		 * so we must not free it (thereby subjecting it to re-use)
 87		 * before all pending connections are closed
 88		 */
 89		svc_disconnect(vcc);
 90		vcc_release(sock);
 91	}
 92	return 0;
 93}
 94
 95static int svc_bind(struct socket *sock, struct sockaddr *sockaddr,
 96		    int sockaddr_len)
 97{
 98	DEFINE_WAIT(wait);
 99	struct sock *sk = sock->sk;
100	struct sockaddr_atmsvc *addr;
101	struct atm_vcc *vcc;
102	int error;
103
104	if (sockaddr_len != sizeof(struct sockaddr_atmsvc))
105		return -EINVAL;
106	lock_sock(sk);
107	if (sock->state == SS_CONNECTED) {
108		error = -EISCONN;
109		goto out;
110	}
111	if (sock->state != SS_UNCONNECTED) {
112		error = -EINVAL;
113		goto out;
114	}
115	vcc = ATM_SD(sock);
116	addr = (struct sockaddr_atmsvc *) sockaddr;
117	if (addr->sas_family != AF_ATMSVC) {
118		error = -EAFNOSUPPORT;
119		goto out;
120	}
121	clear_bit(ATM_VF_BOUND, &vcc->flags);
122	    /* failing rebind will kill old binding */
123	/* @@@ check memory (de)allocation on rebind */
124	if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
125		error = -EBADFD;
126		goto out;
127	}
128	vcc->local = *addr;
129	set_bit(ATM_VF_WAITING, &vcc->flags);
130	sigd_enq(vcc, as_bind, NULL, NULL, &vcc->local);
131	for (;;) {
132		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
133		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
134			break;
135		schedule();
136	}
137	finish_wait(sk_sleep(sk), &wait);
138	clear_bit(ATM_VF_REGIS, &vcc->flags); /* doesn't count */
139	if (!sigd) {
140		error = -EUNATCH;
141		goto out;
142	}
143	if (!sk->sk_err)
144		set_bit(ATM_VF_BOUND, &vcc->flags);
145	error = -sk->sk_err;
146out:
147	release_sock(sk);
148	return error;
149}
150
151static int svc_connect(struct socket *sock, struct sockaddr *sockaddr,
152		       int sockaddr_len, int flags)
153{
154	DEFINE_WAIT(wait);
155	struct sock *sk = sock->sk;
156	struct sockaddr_atmsvc *addr;
157	struct atm_vcc *vcc = ATM_SD(sock);
158	int error;
159
160	pr_debug("%p\n", vcc);
161	lock_sock(sk);
162	if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) {
163		error = -EINVAL;
164		goto out;
165	}
166
167	switch (sock->state) {
168	default:
169		error = -EINVAL;
170		goto out;
171	case SS_CONNECTED:
172		error = -EISCONN;
173		goto out;
174	case SS_CONNECTING:
175		if (test_bit(ATM_VF_WAITING, &vcc->flags)) {
176			error = -EALREADY;
177			goto out;
178		}
179		sock->state = SS_UNCONNECTED;
180		if (sk->sk_err) {
181			error = -sk->sk_err;
182			goto out;
183		}
184		break;
185	case SS_UNCONNECTED:
186		addr = (struct sockaddr_atmsvc *) sockaddr;
187		if (addr->sas_family != AF_ATMSVC) {
188			error = -EAFNOSUPPORT;
189			goto out;
190		}
191		if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
192			error = -EBADFD;
193			goto out;
194		}
195		if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
196		    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS) {
197			error = -EINVAL;
198			goto out;
199		}
200		if (!vcc->qos.txtp.traffic_class &&
201		    !vcc->qos.rxtp.traffic_class) {
202			error = -EINVAL;
203			goto out;
204		}
205		vcc->remote = *addr;
206		set_bit(ATM_VF_WAITING, &vcc->flags);
207		sigd_enq(vcc, as_connect, NULL, NULL, &vcc->remote);
208		if (flags & O_NONBLOCK) {
209			sock->state = SS_CONNECTING;
210			error = -EINPROGRESS;
211			goto out;
212		}
213		error = 0;
214		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
215		while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
216			schedule();
217			if (!signal_pending(current)) {
218				prepare_to_wait(sk_sleep(sk), &wait,
219						TASK_INTERRUPTIBLE);
220				continue;
221			}
222			pr_debug("*ABORT*\n");
223			/*
224			 * This is tricky:
225			 *   Kernel ---close--> Demon
226			 *   Kernel <--close--- Demon
227			 * or
228			 *   Kernel ---close--> Demon
229			 *   Kernel <--error--- Demon
230			 * or
231			 *   Kernel ---close--> Demon
232			 *   Kernel <--okay---- Demon
233			 *   Kernel <--close--- Demon
234			 */
235			sigd_enq(vcc, as_close, NULL, NULL, NULL);
236			while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
237				prepare_to_wait(sk_sleep(sk), &wait,
238						TASK_INTERRUPTIBLE);
239				schedule();
240			}
241			if (!sk->sk_err)
242				while (!test_bit(ATM_VF_RELEASED, &vcc->flags) &&
243				       sigd) {
244					prepare_to_wait(sk_sleep(sk), &wait,
245							TASK_INTERRUPTIBLE);
246					schedule();
247				}
248			clear_bit(ATM_VF_REGIS, &vcc->flags);
249			clear_bit(ATM_VF_RELEASED, &vcc->flags);
250			clear_bit(ATM_VF_CLOSE, &vcc->flags);
251			    /* we're gone now but may connect later */
252			error = -EINTR;
253			break;
254		}
255		finish_wait(sk_sleep(sk), &wait);
256		if (error)
257			goto out;
258		if (!sigd) {
259			error = -EUNATCH;
260			goto out;
261		}
262		if (sk->sk_err) {
263			error = -sk->sk_err;
264			goto out;
265		}
266	}
267
268	vcc->qos.txtp.max_pcr = SELECT_TOP_PCR(vcc->qos.txtp);
269	vcc->qos.txtp.pcr = 0;
270	vcc->qos.txtp.min_pcr = 0;
271
272	error = vcc_connect(sock, vcc->itf, vcc->vpi, vcc->vci);
273	if (!error)
274		sock->state = SS_CONNECTED;
275	else
276		(void)svc_disconnect(vcc);
277out:
278	release_sock(sk);
279	return error;
280}
281
282static int svc_listen(struct socket *sock, int backlog)
283{
284	DEFINE_WAIT(wait);
285	struct sock *sk = sock->sk;
286	struct atm_vcc *vcc = ATM_SD(sock);
287	int error;
288
289	pr_debug("%p\n", vcc);
290	lock_sock(sk);
291	/* let server handle listen on unbound sockets */
292	if (test_bit(ATM_VF_SESSION, &vcc->flags)) {
293		error = -EINVAL;
294		goto out;
295	}
296	if (test_bit(ATM_VF_LISTEN, &vcc->flags)) {
297		error = -EADDRINUSE;
298		goto out;
299	}
300	set_bit(ATM_VF_WAITING, &vcc->flags);
301	sigd_enq(vcc, as_listen, NULL, NULL, &vcc->local);
302	for (;;) {
303		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
304		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
305			break;
306		schedule();
307	}
308	finish_wait(sk_sleep(sk), &wait);
309	if (!sigd) {
310		error = -EUNATCH;
311		goto out;
312	}
313	set_bit(ATM_VF_LISTEN, &vcc->flags);
314	vcc_insert_socket(sk);
315	sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT;
316	error = -sk->sk_err;
317out:
318	release_sock(sk);
319	return error;
320}
321
322static int svc_accept(struct socket *sock, struct socket *newsock, int flags,
323		      bool kern)
324{
325	struct sock *sk = sock->sk;
326	struct sk_buff *skb;
327	struct atmsvc_msg *msg;
328	struct atm_vcc *old_vcc = ATM_SD(sock);
329	struct atm_vcc *new_vcc;
330	int error;
331
332	lock_sock(sk);
333
334	error = svc_create(sock_net(sk), newsock, 0, kern);
335	if (error)
336		goto out;
337
338	new_vcc = ATM_SD(newsock);
339
340	pr_debug("%p -> %p\n", old_vcc, new_vcc);
341	while (1) {
342		DEFINE_WAIT(wait);
343
344		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
345		while (!(skb = skb_dequeue(&sk->sk_receive_queue)) &&
346		       sigd) {
347			if (test_bit(ATM_VF_RELEASED, &old_vcc->flags))
348				break;
349			if (test_bit(ATM_VF_CLOSE, &old_vcc->flags)) {
350				error = -sk->sk_err;
351				break;
352			}
353			if (flags & O_NONBLOCK) {
354				error = -EAGAIN;
355				break;
356			}
357			release_sock(sk);
358			schedule();
359			lock_sock(sk);
360			if (signal_pending(current)) {
361				error = -ERESTARTSYS;
362				break;
363			}
364			prepare_to_wait(sk_sleep(sk), &wait,
365					TASK_INTERRUPTIBLE);
366		}
367		finish_wait(sk_sleep(sk), &wait);
368		if (error)
369			goto out;
370		if (!skb) {
371			error = -EUNATCH;
372			goto out;
373		}
374		msg = (struct atmsvc_msg *)skb->data;
375		new_vcc->qos = msg->qos;
376		set_bit(ATM_VF_HASQOS, &new_vcc->flags);
377		new_vcc->remote = msg->svc;
378		new_vcc->local = msg->local;
379		new_vcc->sap = msg->sap;
380		error = vcc_connect(newsock, msg->pvc.sap_addr.itf,
381				    msg->pvc.sap_addr.vpi,
382				    msg->pvc.sap_addr.vci);
383		dev_kfree_skb(skb);
384		sk->sk_ack_backlog--;
385		if (error) {
386			sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL,
387				  &old_vcc->qos, error);
388			error = error == -EAGAIN ? -EBUSY : error;
389			goto out;
390		}
391		/* wait should be short, so we ignore the non-blocking flag */
392		set_bit(ATM_VF_WAITING, &new_vcc->flags);
393		sigd_enq(new_vcc, as_accept, old_vcc, NULL, NULL);
394		for (;;) {
395			prepare_to_wait(sk_sleep(sk_atm(new_vcc)), &wait,
396					TASK_UNINTERRUPTIBLE);
397			if (!test_bit(ATM_VF_WAITING, &new_vcc->flags) || !sigd)
398				break;
399			release_sock(sk);
400			schedule();
401			lock_sock(sk);
402		}
403		finish_wait(sk_sleep(sk_atm(new_vcc)), &wait);
404		if (!sigd) {
405			error = -EUNATCH;
406			goto out;
407		}
408		if (!sk_atm(new_vcc)->sk_err)
409			break;
410		if (sk_atm(new_vcc)->sk_err != ERESTARTSYS) {
411			error = -sk_atm(new_vcc)->sk_err;
412			goto out;
413		}
414	}
415	newsock->state = SS_CONNECTED;
416out:
417	release_sock(sk);
418	return error;
419}
420
421static int svc_getname(struct socket *sock, struct sockaddr *sockaddr,
422		       int peer)
423{
424	struct sockaddr_atmsvc *addr;
425
426	addr = (struct sockaddr_atmsvc *) sockaddr;
427	memcpy(addr, peer ? &ATM_SD(sock)->remote : &ATM_SD(sock)->local,
428	       sizeof(struct sockaddr_atmsvc));
429	return sizeof(struct sockaddr_atmsvc);
430}
431
432int svc_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)
433{
434	struct sock *sk = sk_atm(vcc);
435	DEFINE_WAIT(wait);
436
437	set_bit(ATM_VF_WAITING, &vcc->flags);
438	sigd_enq2(vcc, as_modify, NULL, NULL, &vcc->local, qos, 0);
439	for (;;) {
440		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
441		if (!test_bit(ATM_VF_WAITING, &vcc->flags) ||
442		    test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) {
443			break;
444		}
445		schedule();
446	}
447	finish_wait(sk_sleep(sk), &wait);
448	if (!sigd)
449		return -EUNATCH;
450	return -sk->sk_err;
451}
452
453static int svc_setsockopt(struct socket *sock, int level, int optname,
454			  char __user *optval, unsigned int optlen)
455{
456	struct sock *sk = sock->sk;
457	struct atm_vcc *vcc = ATM_SD(sock);
458	int value, error = 0;
459
460	lock_sock(sk);
461	switch (optname) {
462	case SO_ATMSAP:
463		if (level != SOL_ATM || optlen != sizeof(struct atm_sap)) {
464			error = -EINVAL;
465			goto out;
466		}
467		if (copy_from_user(&vcc->sap, optval, optlen)) {
468			error = -EFAULT;
469			goto out;
470		}
471		set_bit(ATM_VF_HASSAP, &vcc->flags);
472		break;
473	case SO_MULTIPOINT:
474		if (level != SOL_ATM || optlen != sizeof(int)) {
475			error = -EINVAL;
476			goto out;
477		}
478		if (get_user(value, (int __user *)optval)) {
479			error = -EFAULT;
480			goto out;
481		}
482		if (value == 1)
483			set_bit(ATM_VF_SESSION, &vcc->flags);
484		else if (value == 0)
485			clear_bit(ATM_VF_SESSION, &vcc->flags);
486		else
487			error = -EINVAL;
488		break;
489	default:
490		error = vcc_setsockopt(sock, level, optname, optval, optlen);
491	}
492
493out:
494	release_sock(sk);
495	return error;
496}
497
498static int svc_getsockopt(struct socket *sock, int level, int optname,
499			  char __user *optval, int __user *optlen)
500{
501	struct sock *sk = sock->sk;
502	int error = 0, len;
503
504	lock_sock(sk);
505	if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) {
506		error = vcc_getsockopt(sock, level, optname, optval, optlen);
507		goto out;
508	}
509	if (get_user(len, optlen)) {
510		error = -EFAULT;
511		goto out;
512	}
513	if (len != sizeof(struct atm_sap)) {
514		error = -EINVAL;
515		goto out;
516	}
517	if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) {
518		error = -EFAULT;
519		goto out;
520	}
521out:
522	release_sock(sk);
523	return error;
524}
525
526static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr,
527			int sockaddr_len, int flags)
528{
529	DEFINE_WAIT(wait);
530	struct sock *sk = sock->sk;
531	struct atm_vcc *vcc = ATM_SD(sock);
532	int error;
533
534	lock_sock(sk);
535	set_bit(ATM_VF_WAITING, &vcc->flags);
536	sigd_enq(vcc, as_addparty, NULL, NULL,
537		 (struct sockaddr_atmsvc *) sockaddr);
538	if (flags & O_NONBLOCK) {
539		error = -EINPROGRESS;
540		goto out;
541	}
542	pr_debug("added wait queue\n");
543	for (;;) {
544		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
545		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
546			break;
547		schedule();
548	}
549	finish_wait(sk_sleep(sk), &wait);
550	error = -xchg(&sk->sk_err_soft, 0);
551out:
552	release_sock(sk);
553	return error;
554}
555
556static int svc_dropparty(struct socket *sock, int ep_ref)
557{
558	DEFINE_WAIT(wait);
559	struct sock *sk = sock->sk;
560	struct atm_vcc *vcc = ATM_SD(sock);
561	int error;
562
563	lock_sock(sk);
564	set_bit(ATM_VF_WAITING, &vcc->flags);
565	sigd_enq2(vcc, as_dropparty, NULL, NULL, NULL, NULL, ep_ref);
566	for (;;) {
567		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
568		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
569			break;
570		schedule();
571	}
572	finish_wait(sk_sleep(sk), &wait);
573	if (!sigd) {
574		error = -EUNATCH;
575		goto out;
576	}
577	error = -xchg(&sk->sk_err_soft, 0);
578out:
579	release_sock(sk);
580	return error;
581}
582
583static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
584{
585	int error, ep_ref;
586	struct sockaddr_atmsvc sa;
587	struct atm_vcc *vcc = ATM_SD(sock);
588
589	switch (cmd) {
590	case ATM_ADDPARTY:
591		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
592			return -EINVAL;
593		if (copy_from_user(&sa, (void __user *) arg, sizeof(sa)))
594			return -EFAULT;
595		error = svc_addparty(sock, (struct sockaddr *)&sa, sizeof(sa),
596				     0);
597		break;
598	case ATM_DROPPARTY:
599		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
600			return -EINVAL;
601		if (copy_from_user(&ep_ref, (void __user *) arg, sizeof(int)))
602			return -EFAULT;
603		error = svc_dropparty(sock, ep_ref);
604		break;
605	default:
606		error = vcc_ioctl(sock, cmd, arg);
607	}
608
609	return error;
610}
611
612#ifdef CONFIG_COMPAT
613static int svc_compat_ioctl(struct socket *sock, unsigned int cmd,
614			    unsigned long arg)
615{
616	/* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf.
617	   But actually it takes a struct sockaddr_atmsvc, which doesn't need
618	   compat handling. So all we have to do is fix up cmd... */
619	if (cmd == COMPAT_ATM_ADDPARTY)
620		cmd = ATM_ADDPARTY;
621
622	if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY)
623		return svc_ioctl(sock, cmd, arg);
624	else
625		return vcc_compat_ioctl(sock, cmd, arg);
626}
627#endif /* CONFIG_COMPAT */
628
629static const struct proto_ops svc_proto_ops = {
630	.family =	PF_ATMSVC,
631	.owner =	THIS_MODULE,
632
633	.release =	svc_release,
634	.bind =		svc_bind,
635	.connect =	svc_connect,
636	.socketpair =	sock_no_socketpair,
637	.accept =	svc_accept,
638	.getname =	svc_getname,
639	.poll =		vcc_poll,
640	.ioctl =	svc_ioctl,
641#ifdef CONFIG_COMPAT
642	.compat_ioctl =	svc_compat_ioctl,
643#endif
 
644	.listen =	svc_listen,
645	.shutdown =	svc_shutdown,
646	.setsockopt =	svc_setsockopt,
647	.getsockopt =	svc_getsockopt,
648	.sendmsg =	vcc_sendmsg,
649	.recvmsg =	vcc_recvmsg,
650	.mmap =		sock_no_mmap,
651	.sendpage =	sock_no_sendpage,
652};
653
654
655static int svc_create(struct net *net, struct socket *sock, int protocol,
656		      int kern)
657{
658	int error;
659
660	if (!net_eq(net, &init_net))
661		return -EAFNOSUPPORT;
662
663	sock->ops = &svc_proto_ops;
664	error = vcc_create(net, sock, protocol, AF_ATMSVC, kern);
665	if (error)
666		return error;
667	ATM_SD(sock)->local.sas_family = AF_ATMSVC;
668	ATM_SD(sock)->remote.sas_family = AF_ATMSVC;
669	return 0;
670}
671
672static const struct net_proto_family svc_family_ops = {
673	.family = PF_ATMSVC,
674	.create = svc_create,
675	.owner = THIS_MODULE,
676};
677
678
679/*
680 *	Initialize the ATM SVC protocol family
681 */
682
683int __init atmsvc_init(void)
684{
685	return sock_register(&svc_family_ops);
686}
687
688void atmsvc_exit(void)
689{
690	sock_unregister(PF_ATMSVC);
691}

  1// SPDX-License-Identifier: GPL-2.0
  2/* net/atm/svc.c - ATM SVC sockets */
  3
  4/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  7
  8#include <linux/string.h>
  9#include <linux/net.h>		/* struct socket, struct proto_ops */
 10#include <linux/errno.h>	/* error codes */
 11#include <linux/kernel.h>	/* printk */
 12#include <linux/skbuff.h>
 13#include <linux/wait.h>
 14#include <linux/sched/signal.h>
 15#include <linux/fcntl.h>	/* O_NONBLOCK */
 16#include <linux/init.h>
 17#include <linux/atm.h>		/* ATM stuff */
 18#include <linux/atmsap.h>
 19#include <linux/atmsvc.h>
 20#include <linux/atmdev.h>
 21#include <linux/bitops.h>
 22#include <net/sock.h>		/* for sock_no_* */
 23#include <linux/uaccess.h>
 24#include <linux/export.h>
 25
 26#include "resources.h"
 27#include "common.h"		/* common for PVCs and SVCs */
 28#include "signaling.h"
 29#include "addr.h"
 30
 31static int svc_create(struct net *net, struct socket *sock, int protocol,
 32		      int kern);
 33
 34/*
 35 * Note: since all this is still nicely synchronized with the signaling demon,
 36 *       there's no need to protect sleep loops with clis. If signaling is
 37 *       moved into the kernel, that would change.
 38 */
 39
 40
 41static int svc_shutdown(struct socket *sock, int how)
 42{
 43	return 0;
 44}
 45
 46static void svc_disconnect(struct atm_vcc *vcc)
 47{
 48	DEFINE_WAIT(wait);
 49	struct sk_buff *skb;
 50	struct sock *sk = sk_atm(vcc);
 51
 52	pr_debug("%p\n", vcc);
 53	if (test_bit(ATM_VF_REGIS, &vcc->flags)) {
 54		sigd_enq(vcc, as_close, NULL, NULL, NULL);
 55		for (;;) {
 56			prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
 57			if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd)
 58				break;
 59			schedule();
 60		}
 61		finish_wait(sk_sleep(sk), &wait);
 62	}
 63	/* beware - socket is still in use by atmsigd until the last
 64	   as_indicate has been answered */
 65	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 66		atm_return(vcc, skb->truesize);
 67		pr_debug("LISTEN REL\n");
 68		sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0);
 69		dev_kfree_skb(skb);
 70	}
 71	clear_bit(ATM_VF_REGIS, &vcc->flags);
 72	/* ... may retry later */
 73}
 74
 75static int svc_release(struct socket *sock)
 76{
 77	struct sock *sk = sock->sk;
 78	struct atm_vcc *vcc;
 79
 80	if (sk) {
 81		vcc = ATM_SD(sock);
 82		pr_debug("%p\n", vcc);
 83		clear_bit(ATM_VF_READY, &vcc->flags);
 84		/*
 85		 * VCC pointer is used as a reference,
 86		 * so we must not free it (thereby subjecting it to re-use)
 87		 * before all pending connections are closed
 88		 */
 89		svc_disconnect(vcc);
 90		vcc_release(sock);
 91	}
 92	return 0;
 93}
 94
 95static int svc_bind(struct socket *sock, struct sockaddr *sockaddr,
 96		    int sockaddr_len)
 97{
 98	DEFINE_WAIT(wait);
 99	struct sock *sk = sock->sk;
100	struct sockaddr_atmsvc *addr;
101	struct atm_vcc *vcc;
102	int error;
103
104	if (sockaddr_len != sizeof(struct sockaddr_atmsvc))
105		return -EINVAL;
106	lock_sock(sk);
107	if (sock->state == SS_CONNECTED) {
108		error = -EISCONN;
109		goto out;
110	}
111	if (sock->state != SS_UNCONNECTED) {
112		error = -EINVAL;
113		goto out;
114	}
115	vcc = ATM_SD(sock);
116	addr = (struct sockaddr_atmsvc *) sockaddr;
117	if (addr->sas_family != AF_ATMSVC) {
118		error = -EAFNOSUPPORT;
119		goto out;
120	}
121	clear_bit(ATM_VF_BOUND, &vcc->flags);
122	    /* failing rebind will kill old binding */
123	/* @@@ check memory (de)allocation on rebind */
124	if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
125		error = -EBADFD;
126		goto out;
127	}
128	vcc->local = *addr;
129	set_bit(ATM_VF_WAITING, &vcc->flags);
130	sigd_enq(vcc, as_bind, NULL, NULL, &vcc->local);
131	for (;;) {
132		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
133		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
134			break;
135		schedule();
136	}
137	finish_wait(sk_sleep(sk), &wait);
138	clear_bit(ATM_VF_REGIS, &vcc->flags); /* doesn't count */
139	if (!sigd) {
140		error = -EUNATCH;
141		goto out;
142	}
143	if (!sk->sk_err)
144		set_bit(ATM_VF_BOUND, &vcc->flags);
145	error = -sk->sk_err;
146out:
147	release_sock(sk);
148	return error;
149}
150
151static int svc_connect(struct socket *sock, struct sockaddr *sockaddr,
152		       int sockaddr_len, int flags)
153{
154	DEFINE_WAIT(wait);
155	struct sock *sk = sock->sk;
156	struct sockaddr_atmsvc *addr;
157	struct atm_vcc *vcc = ATM_SD(sock);
158	int error;
159
160	pr_debug("%p\n", vcc);
161	lock_sock(sk);
162	if (sockaddr_len != sizeof(struct sockaddr_atmsvc)) {
163		error = -EINVAL;
164		goto out;
165	}
166
167	switch (sock->state) {
168	default:
169		error = -EINVAL;
170		goto out;
171	case SS_CONNECTED:
172		error = -EISCONN;
173		goto out;
174	case SS_CONNECTING:
175		if (test_bit(ATM_VF_WAITING, &vcc->flags)) {
176			error = -EALREADY;
177			goto out;
178		}
179		sock->state = SS_UNCONNECTED;
180		if (sk->sk_err) {
181			error = -sk->sk_err;
182			goto out;
183		}
184		break;
185	case SS_UNCONNECTED:
186		addr = (struct sockaddr_atmsvc *) sockaddr;
187		if (addr->sas_family != AF_ATMSVC) {
188			error = -EAFNOSUPPORT;
189			goto out;
190		}
191		if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
192			error = -EBADFD;
193			goto out;
194		}
195		if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
196		    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS) {
197			error = -EINVAL;
198			goto out;
199		}
200		if (!vcc->qos.txtp.traffic_class &&
201		    !vcc->qos.rxtp.traffic_class) {
202			error = -EINVAL;
203			goto out;
204		}
205		vcc->remote = *addr;
206		set_bit(ATM_VF_WAITING, &vcc->flags);
207		sigd_enq(vcc, as_connect, NULL, NULL, &vcc->remote);
208		if (flags & O_NONBLOCK) {
209			sock->state = SS_CONNECTING;
210			error = -EINPROGRESS;
211			goto out;
212		}
213		error = 0;
214		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
215		while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
216			schedule();
217			if (!signal_pending(current)) {
218				prepare_to_wait(sk_sleep(sk), &wait,
219						TASK_INTERRUPTIBLE);
220				continue;
221			}
222			pr_debug("*ABORT*\n");
223			/*
224			 * This is tricky:
225			 *   Kernel ---close--> Demon
226			 *   Kernel <--close--- Demon
227			 * or
228			 *   Kernel ---close--> Demon
229			 *   Kernel <--error--- Demon
230			 * or
231			 *   Kernel ---close--> Demon
232			 *   Kernel <--okay---- Demon
233			 *   Kernel <--close--- Demon
234			 */
235			sigd_enq(vcc, as_close, NULL, NULL, NULL);
236			while (test_bit(ATM_VF_WAITING, &vcc->flags) && sigd) {
237				prepare_to_wait(sk_sleep(sk), &wait,
238						TASK_INTERRUPTIBLE);
239				schedule();
240			}
241			if (!sk->sk_err)
242				while (!test_bit(ATM_VF_RELEASED, &vcc->flags) &&
243				       sigd) {
244					prepare_to_wait(sk_sleep(sk), &wait,
245							TASK_INTERRUPTIBLE);
246					schedule();
247				}
248			clear_bit(ATM_VF_REGIS, &vcc->flags);
249			clear_bit(ATM_VF_RELEASED, &vcc->flags);
250			clear_bit(ATM_VF_CLOSE, &vcc->flags);
251			    /* we're gone now but may connect later */
252			error = -EINTR;
253			break;
254		}
255		finish_wait(sk_sleep(sk), &wait);
256		if (error)
257			goto out;
258		if (!sigd) {
259			error = -EUNATCH;
260			goto out;
261		}
262		if (sk->sk_err) {
263			error = -sk->sk_err;
264			goto out;
265		}
266	}
267
268	vcc->qos.txtp.max_pcr = SELECT_TOP_PCR(vcc->qos.txtp);
269	vcc->qos.txtp.pcr = 0;
270	vcc->qos.txtp.min_pcr = 0;
271
272	error = vcc_connect(sock, vcc->itf, vcc->vpi, vcc->vci);
273	if (!error)
274		sock->state = SS_CONNECTED;
275	else
276		(void)svc_disconnect(vcc);
277out:
278	release_sock(sk);
279	return error;
280}
281
282static int svc_listen(struct socket *sock, int backlog)
283{
284	DEFINE_WAIT(wait);
285	struct sock *sk = sock->sk;
286	struct atm_vcc *vcc = ATM_SD(sock);
287	int error;
288
289	pr_debug("%p\n", vcc);
290	lock_sock(sk);
291	/* let server handle listen on unbound sockets */
292	if (test_bit(ATM_VF_SESSION, &vcc->flags)) {
293		error = -EINVAL;
294		goto out;
295	}
296	if (test_bit(ATM_VF_LISTEN, &vcc->flags)) {
297		error = -EADDRINUSE;
298		goto out;
299	}
300	set_bit(ATM_VF_WAITING, &vcc->flags);
301	sigd_enq(vcc, as_listen, NULL, NULL, &vcc->local);
302	for (;;) {
303		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
304		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
305			break;
306		schedule();
307	}
308	finish_wait(sk_sleep(sk), &wait);
309	if (!sigd) {
310		error = -EUNATCH;
311		goto out;
312	}
313	set_bit(ATM_VF_LISTEN, &vcc->flags);
314	vcc_insert_socket(sk);
315	sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT;
316	error = -sk->sk_err;
317out:
318	release_sock(sk);
319	return error;
320}
321
322static int svc_accept(struct socket *sock, struct socket *newsock, int flags,
323		      bool kern)
324{
325	struct sock *sk = sock->sk;
326	struct sk_buff *skb;
327	struct atmsvc_msg *msg;
328	struct atm_vcc *old_vcc = ATM_SD(sock);
329	struct atm_vcc *new_vcc;
330	int error;
331
332	lock_sock(sk);
333
334	error = svc_create(sock_net(sk), newsock, 0, kern);
335	if (error)
336		goto out;
337
338	new_vcc = ATM_SD(newsock);
339
340	pr_debug("%p -> %p\n", old_vcc, new_vcc);
341	while (1) {
342		DEFINE_WAIT(wait);
343
344		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
345		while (!(skb = skb_dequeue(&sk->sk_receive_queue)) &&
346		       sigd) {
347			if (test_bit(ATM_VF_RELEASED, &old_vcc->flags))
348				break;
349			if (test_bit(ATM_VF_CLOSE, &old_vcc->flags)) {
350				error = -sk->sk_err;
351				break;
352			}
353			if (flags & O_NONBLOCK) {
354				error = -EAGAIN;
355				break;
356			}
357			release_sock(sk);
358			schedule();
359			lock_sock(sk);
360			if (signal_pending(current)) {
361				error = -ERESTARTSYS;
362				break;
363			}
364			prepare_to_wait(sk_sleep(sk), &wait,
365					TASK_INTERRUPTIBLE);
366		}
367		finish_wait(sk_sleep(sk), &wait);
368		if (error)
369			goto out;
370		if (!skb) {
371			error = -EUNATCH;
372			goto out;
373		}
374		msg = (struct atmsvc_msg *)skb->data;
375		new_vcc->qos = msg->qos;
376		set_bit(ATM_VF_HASQOS, &new_vcc->flags);
377		new_vcc->remote = msg->svc;
378		new_vcc->local = msg->local;
379		new_vcc->sap = msg->sap;
380		error = vcc_connect(newsock, msg->pvc.sap_addr.itf,
381				    msg->pvc.sap_addr.vpi,
382				    msg->pvc.sap_addr.vci);
383		dev_kfree_skb(skb);
384		sk->sk_ack_backlog--;
385		if (error) {
386			sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL,
387				  &old_vcc->qos, error);
388			error = error == -EAGAIN ? -EBUSY : error;
389			goto out;
390		}
391		/* wait should be short, so we ignore the non-blocking flag */
392		set_bit(ATM_VF_WAITING, &new_vcc->flags);
393		sigd_enq(new_vcc, as_accept, old_vcc, NULL, NULL);
394		for (;;) {
395			prepare_to_wait(sk_sleep(sk_atm(new_vcc)), &wait,
396					TASK_UNINTERRUPTIBLE);
397			if (!test_bit(ATM_VF_WAITING, &new_vcc->flags) || !sigd)
398				break;
399			release_sock(sk);
400			schedule();
401			lock_sock(sk);
402		}
403		finish_wait(sk_sleep(sk_atm(new_vcc)), &wait);
404		if (!sigd) {
405			error = -EUNATCH;
406			goto out;
407		}
408		if (!sk_atm(new_vcc)->sk_err)
409			break;
410		if (sk_atm(new_vcc)->sk_err != ERESTARTSYS) {
411			error = -sk_atm(new_vcc)->sk_err;
412			goto out;
413		}
414	}
415	newsock->state = SS_CONNECTED;
416out:
417	release_sock(sk);
418	return error;
419}
420
421static int svc_getname(struct socket *sock, struct sockaddr *sockaddr,
422		       int peer)
423{
424	struct sockaddr_atmsvc *addr;
425
426	addr = (struct sockaddr_atmsvc *) sockaddr;
427	memcpy(addr, peer ? &ATM_SD(sock)->remote : &ATM_SD(sock)->local,
428	       sizeof(struct sockaddr_atmsvc));
429	return sizeof(struct sockaddr_atmsvc);
430}
431
432int svc_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)
433{
434	struct sock *sk = sk_atm(vcc);
435	DEFINE_WAIT(wait);
436
437	set_bit(ATM_VF_WAITING, &vcc->flags);
438	sigd_enq2(vcc, as_modify, NULL, NULL, &vcc->local, qos, 0);
439	for (;;) {
440		prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);
441		if (!test_bit(ATM_VF_WAITING, &vcc->flags) ||
442		    test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd) {
443			break;
444		}
445		schedule();
446	}
447	finish_wait(sk_sleep(sk), &wait);
448	if (!sigd)
449		return -EUNATCH;
450	return -sk->sk_err;
451}
452
453static int svc_setsockopt(struct socket *sock, int level, int optname,
454			  char __user *optval, unsigned int optlen)
455{
456	struct sock *sk = sock->sk;
457	struct atm_vcc *vcc = ATM_SD(sock);
458	int value, error = 0;
459
460	lock_sock(sk);
461	switch (optname) {
462	case SO_ATMSAP:
463		if (level != SOL_ATM || optlen != sizeof(struct atm_sap)) {
464			error = -EINVAL;
465			goto out;
466		}
467		if (copy_from_user(&vcc->sap, optval, optlen)) {
468			error = -EFAULT;
469			goto out;
470		}
471		set_bit(ATM_VF_HASSAP, &vcc->flags);
472		break;
473	case SO_MULTIPOINT:
474		if (level != SOL_ATM || optlen != sizeof(int)) {
475			error = -EINVAL;
476			goto out;
477		}
478		if (get_user(value, (int __user *)optval)) {
479			error = -EFAULT;
480			goto out;
481		}
482		if (value == 1)
483			set_bit(ATM_VF_SESSION, &vcc->flags);
484		else if (value == 0)
485			clear_bit(ATM_VF_SESSION, &vcc->flags);
486		else
487			error = -EINVAL;
488		break;
489	default:
490		error = vcc_setsockopt(sock, level, optname, optval, optlen);
491	}
492
493out:
494	release_sock(sk);
495	return error;
496}
497
498static int svc_getsockopt(struct socket *sock, int level, int optname,
499			  char __user *optval, int __user *optlen)
500{
501	struct sock *sk = sock->sk;
502	int error = 0, len;
503
504	lock_sock(sk);
505	if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) {
506		error = vcc_getsockopt(sock, level, optname, optval, optlen);
507		goto out;
508	}
509	if (get_user(len, optlen)) {
510		error = -EFAULT;
511		goto out;
512	}
513	if (len != sizeof(struct atm_sap)) {
514		error = -EINVAL;
515		goto out;
516	}
517	if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) {
518		error = -EFAULT;
519		goto out;
520	}
521out:
522	release_sock(sk);
523	return error;
524}
525
526static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr,
527			int sockaddr_len, int flags)
528{
529	DEFINE_WAIT(wait);
530	struct sock *sk = sock->sk;
531	struct atm_vcc *vcc = ATM_SD(sock);
532	int error;
533
534	lock_sock(sk);
535	set_bit(ATM_VF_WAITING, &vcc->flags);
536	sigd_enq(vcc, as_addparty, NULL, NULL,
537		 (struct sockaddr_atmsvc *) sockaddr);
538	if (flags & O_NONBLOCK) {
539		error = -EINPROGRESS;
540		goto out;
541	}
542	pr_debug("added wait queue\n");
543	for (;;) {
544		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
545		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
546			break;
547		schedule();
548	}
549	finish_wait(sk_sleep(sk), &wait);
550	error = -xchg(&sk->sk_err_soft, 0);
551out:
552	release_sock(sk);
553	return error;
554}
555
556static int svc_dropparty(struct socket *sock, int ep_ref)
557{
558	DEFINE_WAIT(wait);
559	struct sock *sk = sock->sk;
560	struct atm_vcc *vcc = ATM_SD(sock);
561	int error;
562
563	lock_sock(sk);
564	set_bit(ATM_VF_WAITING, &vcc->flags);
565	sigd_enq2(vcc, as_dropparty, NULL, NULL, NULL, NULL, ep_ref);
566	for (;;) {
567		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
568		if (!test_bit(ATM_VF_WAITING, &vcc->flags) || !sigd)
569			break;
570		schedule();
571	}
572	finish_wait(sk_sleep(sk), &wait);
573	if (!sigd) {
574		error = -EUNATCH;
575		goto out;
576	}
577	error = -xchg(&sk->sk_err_soft, 0);
578out:
579	release_sock(sk);
580	return error;
581}
582
583static int svc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
584{
585	int error, ep_ref;
586	struct sockaddr_atmsvc sa;
587	struct atm_vcc *vcc = ATM_SD(sock);
588
589	switch (cmd) {
590	case ATM_ADDPARTY:
591		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
592			return -EINVAL;
593		if (copy_from_user(&sa, (void __user *) arg, sizeof(sa)))
594			return -EFAULT;
595		error = svc_addparty(sock, (struct sockaddr *)&sa, sizeof(sa),
596				     0);
597		break;
598	case ATM_DROPPARTY:
599		if (!test_bit(ATM_VF_SESSION, &vcc->flags))
600			return -EINVAL;
601		if (copy_from_user(&ep_ref, (void __user *) arg, sizeof(int)))
602			return -EFAULT;
603		error = svc_dropparty(sock, ep_ref);
604		break;
605	default:
606		error = vcc_ioctl(sock, cmd, arg);
607	}
608
609	return error;
610}
611
612#ifdef CONFIG_COMPAT
613static int svc_compat_ioctl(struct socket *sock, unsigned int cmd,
614			    unsigned long arg)
615{
616	/* The definition of ATM_ADDPARTY uses the size of struct atm_iobuf.
617	   But actually it takes a struct sockaddr_atmsvc, which doesn't need
618	   compat handling. So all we have to do is fix up cmd... */
619	if (cmd == COMPAT_ATM_ADDPARTY)
620		cmd = ATM_ADDPARTY;
621
622	if (cmd == ATM_ADDPARTY || cmd == ATM_DROPPARTY)
623		return svc_ioctl(sock, cmd, arg);
624	else
625		return vcc_compat_ioctl(sock, cmd, arg);
626}
627#endif /* CONFIG_COMPAT */
628
629static const struct proto_ops svc_proto_ops = {
630	.family =	PF_ATMSVC,
631	.owner =	THIS_MODULE,
632
633	.release =	svc_release,
634	.bind =		svc_bind,
635	.connect =	svc_connect,
636	.socketpair =	sock_no_socketpair,
637	.accept =	svc_accept,
638	.getname =	svc_getname,
639	.poll =		vcc_poll,
640	.ioctl =	svc_ioctl,
641#ifdef CONFIG_COMPAT
642	.compat_ioctl =	svc_compat_ioctl,
643#endif
644	.gettstamp =	sock_gettstamp,
645	.listen =	svc_listen,
646	.shutdown =	svc_shutdown,
647	.setsockopt =	svc_setsockopt,
648	.getsockopt =	svc_getsockopt,
649	.sendmsg =	vcc_sendmsg,
650	.recvmsg =	vcc_recvmsg,
651	.mmap =		sock_no_mmap,
652	.sendpage =	sock_no_sendpage,
653};
654
655
656static int svc_create(struct net *net, struct socket *sock, int protocol,
657		      int kern)
658{
659	int error;
660
661	if (!net_eq(net, &init_net))
662		return -EAFNOSUPPORT;
663
664	sock->ops = &svc_proto_ops;
665	error = vcc_create(net, sock, protocol, AF_ATMSVC, kern);
666	if (error)
667		return error;
668	ATM_SD(sock)->local.sas_family = AF_ATMSVC;
669	ATM_SD(sock)->remote.sas_family = AF_ATMSVC;
670	return 0;
671}
672
673static const struct net_proto_family svc_family_ops = {
674	.family = PF_ATMSVC,
675	.create = svc_create,
676	.owner = THIS_MODULE,
677};
678
679
680/*
681 *	Initialize the ATM SVC protocol family
682 */
683
684int __init atmsvc_init(void)
685{
686	return sock_register(&svc_family_ops);
687}
688
689void atmsvc_exit(void)
690{
691	sock_unregister(PF_ATMSVC);
692}