xref: /linux/net/atm/common.c (revision 45079e00133ee78fd216ccc4285534044ea69173)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* net/atm/common.c - ATM sockets (common part for PVC and SVC) */
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/module.h>
9 #include <linux/kmod.h>
10 #include <linux/net.h>		/* struct socket, struct proto_ops */
11 #include <linux/atm.h>		/* ATM stuff */
12 #include <linux/atmdev.h>
13 #include <linux/socket.h>	/* SOL_SOCKET */
14 #include <linux/errno.h>	/* error codes */
15 #include <linux/capability.h>
16 #include <linux/mm.h>
17 #include <linux/sched/signal.h>
18 #include <linux/time64.h>	/* 64-bit time for seconds */
19 #include <linux/skbuff.h>
20 #include <linux/bitops.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <net/sock.h>		/* struct sock */
24 #include <linux/uaccess.h>
25 #include <linux/poll.h>
26 #include <linux/uio.h>
27 
28 #include <linux/atomic.h>
29 
30 #include "resources.h"		/* atm_find_dev */
31 #include "common.h"		/* prototypes */
32 #include "protocols.h"		/* atm_init_<transport> */
33 #include "addr.h"		/* address registry */
34 #include "signaling.h"		/* for WAITING and sigd_attach */
35 
36 struct hlist_head vcc_hash[VCC_HTABLE_SIZE];
37 EXPORT_SYMBOL(vcc_hash);
38 
39 DEFINE_RWLOCK(vcc_sklist_lock);
40 EXPORT_SYMBOL(vcc_sklist_lock);
41 
42 static ATOMIC_NOTIFIER_HEAD(atm_dev_notify_chain);
43 
44 static void __vcc_insert_socket(struct sock *sk)
45 {
46 	struct atm_vcc *vcc = atm_sk(sk);
47 	struct hlist_head *head = &vcc_hash[vcc->vci & (VCC_HTABLE_SIZE - 1)];
48 	sk->sk_hash = vcc->vci & (VCC_HTABLE_SIZE - 1);
49 	sk_add_node(sk, head);
50 }
51 
52 void vcc_insert_socket(struct sock *sk)
53 {
54 	write_lock_irq(&vcc_sklist_lock);
55 	__vcc_insert_socket(sk);
56 	write_unlock_irq(&vcc_sklist_lock);
57 }
58 EXPORT_SYMBOL(vcc_insert_socket);
59 
60 static void vcc_remove_socket(struct sock *sk)
61 {
62 	write_lock_irq(&vcc_sklist_lock);
63 	sk_del_node_init(sk);
64 	write_unlock_irq(&vcc_sklist_lock);
65 }
66 
67 static bool vcc_tx_ready(struct atm_vcc *vcc, unsigned int size)
68 {
69 	struct sock *sk = sk_atm(vcc);
70 
71 	if (sk_wmem_alloc_get(sk) && !atm_may_send(vcc, size)) {
72 		pr_debug("Sorry: wmem_alloc = %d, size = %d, sndbuf = %d\n",
73 			 sk_wmem_alloc_get(sk), size, sk->sk_sndbuf);
74 		return false;
75 	}
76 	return true;
77 }
78 
79 static void vcc_sock_destruct(struct sock *sk)
80 {
81 	if (atomic_read(&sk->sk_rmem_alloc))
82 		printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
83 		       __func__, atomic_read(&sk->sk_rmem_alloc));
84 
85 	if (refcount_read(&sk->sk_wmem_alloc))
86 		printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
87 		       __func__, refcount_read(&sk->sk_wmem_alloc));
88 }
89 
90 static void vcc_def_wakeup(struct sock *sk)
91 {
92 	struct socket_wq *wq;
93 
94 	rcu_read_lock();
95 	wq = rcu_dereference(sk->sk_wq);
96 	if (skwq_has_sleeper(wq))
97 		wake_up(&wq->wait);
98 	rcu_read_unlock();
99 }
100 
101 static inline int vcc_writable(struct sock *sk)
102 {
103 	struct atm_vcc *vcc = atm_sk(sk);
104 
105 	return (vcc->qos.txtp.max_sdu +
106 		refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
107 }
108 
109 static void vcc_write_space(struct sock *sk)
110 {
111 	struct socket_wq *wq;
112 
113 	rcu_read_lock();
114 
115 	if (vcc_writable(sk)) {
116 		wq = rcu_dereference(sk->sk_wq);
117 		if (skwq_has_sleeper(wq))
118 			wake_up_interruptible(&wq->wait);
119 
120 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
121 	}
122 
123 	rcu_read_unlock();
124 }
125 
126 static void vcc_release_cb(struct sock *sk)
127 {
128 	struct atm_vcc *vcc = atm_sk(sk);
129 
130 	if (vcc->release_cb)
131 		vcc->release_cb(vcc);
132 }
133 
134 static struct proto vcc_proto = {
135 	.name	  = "VCC",
136 	.owner	  = THIS_MODULE,
137 	.obj_size = sizeof(struct atm_vcc),
138 	.release_cb = vcc_release_cb,
139 };
140 
141 int vcc_create(struct net *net, struct socket *sock, int protocol, int family, int kern)
142 {
143 	struct sock *sk;
144 	struct atm_vcc *vcc;
145 
146 	sock->sk = NULL;
147 	if (sock->type == SOCK_STREAM)
148 		return -EINVAL;
149 	sk = sk_alloc(net, family, GFP_KERNEL, &vcc_proto, kern);
150 	if (!sk)
151 		return -ENOMEM;
152 	sock_init_data(sock, sk);
153 	sk->sk_state_change = vcc_def_wakeup;
154 	sk->sk_write_space = vcc_write_space;
155 
156 	vcc = atm_sk(sk);
157 	vcc->dev = NULL;
158 	memset(&vcc->local, 0, sizeof(struct sockaddr_atmsvc));
159 	memset(&vcc->remote, 0, sizeof(struct sockaddr_atmsvc));
160 	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
161 	refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
162 	atomic_set(&sk->sk_rmem_alloc, 0);
163 	vcc->push = NULL;
164 	vcc->pop = NULL;
165 	vcc->owner = NULL;
166 	vcc->push_oam = NULL;
167 	vcc->release_cb = NULL;
168 	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
169 	vcc->atm_options = vcc->aal_options = 0;
170 	sk->sk_destruct = vcc_sock_destruct;
171 	return 0;
172 }
173 
174 static void vcc_destroy_socket(struct sock *sk)
175 {
176 	struct atm_vcc *vcc = atm_sk(sk);
177 	struct sk_buff *skb;
178 
179 	set_bit(ATM_VF_CLOSE, &vcc->flags);
180 	clear_bit(ATM_VF_READY, &vcc->flags);
181 	if (vcc->dev && vcc->dev->ops->close)
182 		vcc->dev->ops->close(vcc);
183 	if (vcc->push)
184 		vcc->push(vcc, NULL); /* atmarpd has no push */
185 	module_put(vcc->owner);
186 
187 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
188 		atm_return(vcc, skb->truesize);
189 		kfree_skb(skb);
190 	}
191 
192 	if (vcc->dev && vcc->dev->ops->owner) {
193 		module_put(vcc->dev->ops->owner);
194 		atm_dev_put(vcc->dev);
195 	}
196 
197 	vcc_remove_socket(sk);
198 }
199 
200 int vcc_release(struct socket *sock)
201 {
202 	struct sock *sk = sock->sk;
203 
204 	if (sk) {
205 		lock_sock(sk);
206 		vcc_destroy_socket(sock->sk);
207 		release_sock(sk);
208 		sock_put(sk);
209 	}
210 
211 	return 0;
212 }
213 
214 void vcc_release_async(struct atm_vcc *vcc, int reply)
215 {
216 	struct sock *sk = sk_atm(vcc);
217 
218 	set_bit(ATM_VF_CLOSE, &vcc->flags);
219 	sk->sk_shutdown |= RCV_SHUTDOWN;
220 	sk->sk_err = -reply;
221 	clear_bit(ATM_VF_WAITING, &vcc->flags);
222 	sk->sk_state_change(sk);
223 }
224 EXPORT_SYMBOL(vcc_release_async);
225 
226 void vcc_process_recv_queue(struct atm_vcc *vcc)
227 {
228 	struct sk_buff_head queue, *rq;
229 	struct sk_buff *skb, *tmp;
230 	unsigned long flags;
231 
232 	__skb_queue_head_init(&queue);
233 	rq = &sk_atm(vcc)->sk_receive_queue;
234 
235 	spin_lock_irqsave(&rq->lock, flags);
236 	skb_queue_splice_init(rq, &queue);
237 	spin_unlock_irqrestore(&rq->lock, flags);
238 
239 	skb_queue_walk_safe(&queue, skb, tmp) {
240 		__skb_unlink(skb, &queue);
241 		vcc->push(vcc, skb);
242 	}
243 }
244 EXPORT_SYMBOL(vcc_process_recv_queue);
245 
246 void atm_dev_signal_change(struct atm_dev *dev, char signal)
247 {
248 	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
249 		__func__, signal, dev, dev->number, dev->signal);
250 
251 	/* atm driver sending invalid signal */
252 	WARN_ON(signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND);
253 
254 	if (dev->signal == signal)
255 		return; /* no change */
256 
257 	dev->signal = signal;
258 
259 	atomic_notifier_call_chain(&atm_dev_notify_chain, signal, dev);
260 }
261 EXPORT_SYMBOL(atm_dev_signal_change);
262 
263 void atm_dev_release_vccs(struct atm_dev *dev)
264 {
265 	int i;
266 
267 	write_lock_irq(&vcc_sklist_lock);
268 	for (i = 0; i < VCC_HTABLE_SIZE; i++) {
269 		struct hlist_head *head = &vcc_hash[i];
270 		struct hlist_node *tmp;
271 		struct sock *s;
272 		struct atm_vcc *vcc;
273 
274 		sk_for_each_safe(s, tmp, head) {
275 			vcc = atm_sk(s);
276 			if (vcc->dev == dev) {
277 				vcc_release_async(vcc, -EPIPE);
278 				sk_del_node_init(s);
279 			}
280 		}
281 	}
282 	write_unlock_irq(&vcc_sklist_lock);
283 }
284 EXPORT_SYMBOL(atm_dev_release_vccs);
285 
286 static int adjust_tp(struct atm_trafprm *tp, unsigned char aal)
287 {
288 	int max_sdu;
289 
290 	if (!tp->traffic_class)
291 		return 0;
292 	switch (aal) {
293 	case ATM_AAL0:
294 		max_sdu = ATM_CELL_SIZE-1;
295 		break;
296 	case ATM_AAL34:
297 		max_sdu = ATM_MAX_AAL34_PDU;
298 		break;
299 	default:
300 		pr_warn("AAL problems ... (%d)\n", aal);
301 		fallthrough;
302 	case ATM_AAL5:
303 		max_sdu = ATM_MAX_AAL5_PDU;
304 	}
305 	if (!tp->max_sdu)
306 		tp->max_sdu = max_sdu;
307 	else if (tp->max_sdu > max_sdu)
308 		return -EINVAL;
309 	if (!tp->max_cdv)
310 		tp->max_cdv = ATM_MAX_CDV;
311 	return 0;
312 }
313 
314 static int check_ci(const struct atm_vcc *vcc, short vpi, int vci)
315 {
316 	struct hlist_head *head = &vcc_hash[vci & (VCC_HTABLE_SIZE - 1)];
317 	struct sock *s;
318 	struct atm_vcc *walk;
319 
320 	sk_for_each(s, head) {
321 		walk = atm_sk(s);
322 		if (walk->dev != vcc->dev)
323 			continue;
324 		if (test_bit(ATM_VF_ADDR, &walk->flags) && walk->vpi == vpi &&
325 		    walk->vci == vci && ((walk->qos.txtp.traffic_class !=
326 		    ATM_NONE && vcc->qos.txtp.traffic_class != ATM_NONE) ||
327 		    (walk->qos.rxtp.traffic_class != ATM_NONE &&
328 		    vcc->qos.rxtp.traffic_class != ATM_NONE)))
329 			return -EADDRINUSE;
330 	}
331 
332 	/* allow VCCs with same VPI/VCI iff they don't collide on
333 	   TX/RX (but we may refuse such sharing for other reasons,
334 	   e.g. if protocol requires to have both channels) */
335 
336 	return 0;
337 }
338 
339 static int find_ci(const struct atm_vcc *vcc, short *vpi, int *vci)
340 {
341 	static short p;        /* poor man's per-device cache */
342 	static int c;
343 	short old_p;
344 	int old_c;
345 	int err;
346 
347 	if (*vpi != ATM_VPI_ANY && *vci != ATM_VCI_ANY) {
348 		err = check_ci(vcc, *vpi, *vci);
349 		return err;
350 	}
351 	/* last scan may have left values out of bounds for current device */
352 	if (*vpi != ATM_VPI_ANY)
353 		p = *vpi;
354 	else if (p >= 1 << vcc->dev->ci_range.vpi_bits)
355 		p = 0;
356 	if (*vci != ATM_VCI_ANY)
357 		c = *vci;
358 	else if (c < ATM_NOT_RSV_VCI || c >= 1 << vcc->dev->ci_range.vci_bits)
359 			c = ATM_NOT_RSV_VCI;
360 	old_p = p;
361 	old_c = c;
362 	do {
363 		if (!check_ci(vcc, p, c)) {
364 			*vpi = p;
365 			*vci = c;
366 			return 0;
367 		}
368 		if (*vci == ATM_VCI_ANY) {
369 			c++;
370 			if (c >= 1 << vcc->dev->ci_range.vci_bits)
371 				c = ATM_NOT_RSV_VCI;
372 		}
373 		if ((c == ATM_NOT_RSV_VCI || *vci != ATM_VCI_ANY) &&
374 		    *vpi == ATM_VPI_ANY) {
375 			p++;
376 			if (p >= 1 << vcc->dev->ci_range.vpi_bits)
377 				p = 0;
378 		}
379 	} while (old_p != p || old_c != c);
380 	return -EADDRINUSE;
381 }
382 
383 static int __vcc_connect(struct atm_vcc *vcc, struct atm_dev *dev, short vpi,
384 			 int vci)
385 {
386 	struct sock *sk = sk_atm(vcc);
387 	int error;
388 
389 	if ((vpi != ATM_VPI_UNSPEC && vpi != ATM_VPI_ANY &&
390 	    vpi >> dev->ci_range.vpi_bits) || (vci != ATM_VCI_UNSPEC &&
391 	    vci != ATM_VCI_ANY && vci >> dev->ci_range.vci_bits))
392 		return -EINVAL;
393 	if (vci > 0 && vci < ATM_NOT_RSV_VCI && !capable(CAP_NET_BIND_SERVICE))
394 		return -EPERM;
395 	error = -ENODEV;
396 	if (!try_module_get(dev->ops->owner))
397 		return error;
398 	vcc->dev = dev;
399 	write_lock_irq(&vcc_sklist_lock);
400 	if (test_bit(ATM_DF_REMOVED, &dev->flags) ||
401 	    (error = find_ci(vcc, &vpi, &vci))) {
402 		write_unlock_irq(&vcc_sklist_lock);
403 		goto fail_module_put;
404 	}
405 	vcc->vpi = vpi;
406 	vcc->vci = vci;
407 	__vcc_insert_socket(sk);
408 	write_unlock_irq(&vcc_sklist_lock);
409 	switch (vcc->qos.aal) {
410 	case ATM_AAL0:
411 		error = atm_init_aal0(vcc);
412 		vcc->stats = &dev->stats.aal0;
413 		break;
414 	case ATM_AAL34:
415 		error = atm_init_aal34(vcc);
416 		vcc->stats = &dev->stats.aal34;
417 		break;
418 	case ATM_NO_AAL:
419 		/* ATM_AAL5 is also used in the "0 for default" case */
420 		vcc->qos.aal = ATM_AAL5;
421 		fallthrough;
422 	case ATM_AAL5:
423 		error = atm_init_aal5(vcc);
424 		vcc->stats = &dev->stats.aal5;
425 		break;
426 	default:
427 		error = -EPROTOTYPE;
428 	}
429 	if (!error)
430 		error = adjust_tp(&vcc->qos.txtp, vcc->qos.aal);
431 	if (!error)
432 		error = adjust_tp(&vcc->qos.rxtp, vcc->qos.aal);
433 	if (error)
434 		goto fail;
435 	pr_debug("VCC %d.%d, AAL %d\n", vpi, vci, vcc->qos.aal);
436 	pr_debug("  TX: %d, PCR %d..%d, SDU %d\n",
437 		 vcc->qos.txtp.traffic_class,
438 		 vcc->qos.txtp.min_pcr,
439 		 vcc->qos.txtp.max_pcr,
440 		 vcc->qos.txtp.max_sdu);
441 	pr_debug("  RX: %d, PCR %d..%d, SDU %d\n",
442 		 vcc->qos.rxtp.traffic_class,
443 		 vcc->qos.rxtp.min_pcr,
444 		 vcc->qos.rxtp.max_pcr,
445 		 vcc->qos.rxtp.max_sdu);
446 
447 	if (dev->ops->open) {
448 		error = dev->ops->open(vcc);
449 		if (error)
450 			goto fail;
451 	}
452 	return 0;
453 
454 fail:
455 	vcc_remove_socket(sk);
456 fail_module_put:
457 	module_put(dev->ops->owner);
458 	/* ensure we get dev module ref count correct */
459 	vcc->dev = NULL;
460 	return error;
461 }
462 
463 int vcc_connect(struct socket *sock, int itf, short vpi, int vci)
464 {
465 	struct atm_dev *dev;
466 	struct atm_vcc *vcc = ATM_SD(sock);
467 	int error;
468 
469 	pr_debug("(vpi %d, vci %d)\n", vpi, vci);
470 	if (sock->state == SS_CONNECTED)
471 		return -EISCONN;
472 	if (sock->state != SS_UNCONNECTED)
473 		return -EINVAL;
474 	if (!(vpi || vci))
475 		return -EINVAL;
476 
477 	if (vpi != ATM_VPI_UNSPEC && vci != ATM_VCI_UNSPEC)
478 		clear_bit(ATM_VF_PARTIAL, &vcc->flags);
479 	else
480 		if (test_bit(ATM_VF_PARTIAL, &vcc->flags))
481 			return -EINVAL;
482 	pr_debug("(TX: cl %d,bw %d-%d,sdu %d; "
483 		 "RX: cl %d,bw %d-%d,sdu %d,AAL %s%d)\n",
484 		 vcc->qos.txtp.traffic_class, vcc->qos.txtp.min_pcr,
485 		 vcc->qos.txtp.max_pcr, vcc->qos.txtp.max_sdu,
486 		 vcc->qos.rxtp.traffic_class, vcc->qos.rxtp.min_pcr,
487 		 vcc->qos.rxtp.max_pcr, vcc->qos.rxtp.max_sdu,
488 		 vcc->qos.aal == ATM_AAL5 ? "" :
489 		 vcc->qos.aal == ATM_AAL0 ? "" : " ??? code ",
490 		 vcc->qos.aal == ATM_AAL0 ? 0 : vcc->qos.aal);
491 	if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
492 		return -EBADFD;
493 	if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
494 	    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS)
495 		return -EINVAL;
496 	if (likely(itf != ATM_ITF_ANY)) {
497 		dev = try_then_request_module(atm_dev_lookup(itf),
498 					      "atm-device-%d", itf);
499 	} else {
500 		dev = NULL;
501 		mutex_lock(&atm_dev_mutex);
502 		if (!list_empty(&atm_devs)) {
503 			dev = list_entry(atm_devs.next,
504 					 struct atm_dev, dev_list);
505 			atm_dev_hold(dev);
506 		}
507 		mutex_unlock(&atm_dev_mutex);
508 	}
509 	if (!dev)
510 		return -ENODEV;
511 	error = __vcc_connect(vcc, dev, vpi, vci);
512 	if (error) {
513 		atm_dev_put(dev);
514 		return error;
515 	}
516 	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC)
517 		set_bit(ATM_VF_PARTIAL, &vcc->flags);
518 	if (test_bit(ATM_VF_READY, &ATM_SD(sock)->flags))
519 		sock->state = SS_CONNECTED;
520 	return 0;
521 }
522 
523 int vcc_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
524 		int flags)
525 {
526 	struct sock *sk = sock->sk;
527 	struct atm_vcc *vcc;
528 	struct sk_buff *skb;
529 	int copied, error = -EINVAL;
530 
531 	if (sock->state != SS_CONNECTED)
532 		return -ENOTCONN;
533 
534 	/* only handle MSG_DONTWAIT and MSG_PEEK */
535 	if (flags & ~(MSG_DONTWAIT | MSG_PEEK))
536 		return -EOPNOTSUPP;
537 
538 	vcc = ATM_SD(sock);
539 	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
540 	    test_bit(ATM_VF_CLOSE, &vcc->flags) ||
541 	    !test_bit(ATM_VF_READY, &vcc->flags))
542 		return 0;
543 
544 	skb = skb_recv_datagram(sk, flags, &error);
545 	if (!skb)
546 		return error;
547 
548 	copied = skb->len;
549 	if (copied > size) {
550 		copied = size;
551 		msg->msg_flags |= MSG_TRUNC;
552 	}
553 
554 	error = skb_copy_datagram_msg(skb, 0, msg, copied);
555 	if (error)
556 		return error;
557 	sock_recv_cmsgs(msg, sk, skb);
558 
559 	if (!(flags & MSG_PEEK)) {
560 		pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc),
561 			 skb->truesize);
562 		atm_return(vcc, skb->truesize);
563 	}
564 
565 	skb_free_datagram(sk, skb);
566 	return copied;
567 }
568 
569 int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
570 {
571 	struct sock *sk = sock->sk;
572 	DEFINE_WAIT(wait);
573 	struct atm_vcc *vcc;
574 	struct sk_buff *skb;
575 	int eff, error;
576 
577 	lock_sock(sk);
578 	if (sock->state != SS_CONNECTED) {
579 		error = -ENOTCONN;
580 		goto out;
581 	}
582 	if (m->msg_name) {
583 		error = -EISCONN;
584 		goto out;
585 	}
586 	vcc = ATM_SD(sock);
587 	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
588 	    test_bit(ATM_VF_CLOSE, &vcc->flags) ||
589 	    !test_bit(ATM_VF_READY, &vcc->flags)) {
590 		error = -EPIPE;
591 		send_sig(SIGPIPE, current, 0);
592 		goto out;
593 	}
594 	if (!size) {
595 		error = 0;
596 		goto out;
597 	}
598 	if (size > vcc->qos.txtp.max_sdu) {
599 		error = -EMSGSIZE;
600 		goto out;
601 	}
602 
603 	eff = (size+3) & ~3; /* align to word boundary */
604 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
605 	error = 0;
606 	while (!vcc_tx_ready(vcc, eff)) {
607 		if (m->msg_flags & MSG_DONTWAIT) {
608 			error = -EAGAIN;
609 			break;
610 		}
611 		schedule();
612 		if (signal_pending(current)) {
613 			error = -ERESTARTSYS;
614 			break;
615 		}
616 		if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
617 		    test_bit(ATM_VF_CLOSE, &vcc->flags) ||
618 		    !test_bit(ATM_VF_READY, &vcc->flags)) {
619 			error = -EPIPE;
620 			send_sig(SIGPIPE, current, 0);
621 			break;
622 		}
623 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
624 	}
625 	finish_wait(sk_sleep(sk), &wait);
626 	if (error)
627 		goto out;
628 
629 	skb = alloc_skb(eff, GFP_KERNEL);
630 	if (!skb) {
631 		error = -ENOMEM;
632 		goto out;
633 	}
634 	pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
635 	atm_account_tx(vcc, skb);
636 
637 	skb->dev = NULL; /* for paths shared with net_device interfaces */
638 	if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
639 		error = -EFAULT;
640 		goto free_skb;
641 	}
642 	if (eff != size)
643 		memset(skb->data + size, 0, eff-size);
644 
645 	if (vcc->dev->ops->pre_send) {
646 		error = vcc->dev->ops->pre_send(vcc, skb);
647 		if (error)
648 			goto free_skb;
649 	}
650 
651 	error = vcc->dev->ops->send(vcc, skb);
652 	error = error ? error : size;
653 out:
654 	release_sock(sk);
655 	return error;
656 free_skb:
657 	atm_return_tx(vcc, skb);
658 	kfree_skb(skb);
659 	goto out;
660 }
661 
662 __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
663 {
664 	struct sock *sk = sock->sk;
665 	struct atm_vcc *vcc;
666 	__poll_t mask;
667 
668 	sock_poll_wait(file, sock, wait);
669 	mask = 0;
670 
671 	vcc = ATM_SD(sock);
672 
673 	/* exceptional events */
674 	if (sk->sk_err)
675 		mask = EPOLLERR;
676 
677 	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
678 	    test_bit(ATM_VF_CLOSE, &vcc->flags))
679 		mask |= EPOLLHUP;
680 
681 	/* readable? */
682 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
683 		mask |= EPOLLIN | EPOLLRDNORM;
684 
685 	/* writable? */
686 	if (sock->state == SS_CONNECTING &&
687 	    test_bit(ATM_VF_WAITING, &vcc->flags))
688 		return mask;
689 
690 	if (vcc->qos.txtp.traffic_class != ATM_NONE &&
691 	    vcc_writable(sk))
692 		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
693 
694 	return mask;
695 }
696 
697 static int atm_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)
698 {
699 	int error;
700 
701 	/*
702 	 * Don't let the QoS change the already connected AAL type nor the
703 	 * traffic class.
704 	 */
705 	if (qos->aal != vcc->qos.aal ||
706 	    qos->rxtp.traffic_class != vcc->qos.rxtp.traffic_class ||
707 	    qos->txtp.traffic_class != vcc->qos.txtp.traffic_class)
708 		return -EINVAL;
709 	error = adjust_tp(&qos->txtp, qos->aal);
710 	if (!error)
711 		error = adjust_tp(&qos->rxtp, qos->aal);
712 	if (error)
713 		return error;
714 	if (!vcc->dev->ops->change_qos)
715 		return -EOPNOTSUPP;
716 	if (sk_atm(vcc)->sk_family == AF_ATMPVC)
717 		return vcc->dev->ops->change_qos(vcc, qos, ATM_MF_SET);
718 	return svc_change_qos(vcc, qos);
719 }
720 
721 static int check_tp(const struct atm_trafprm *tp)
722 {
723 	/* @@@ Should be merged with adjust_tp */
724 	if (!tp->traffic_class || tp->traffic_class == ATM_ANYCLASS)
725 		return 0;
726 	if (tp->traffic_class != ATM_UBR && !tp->min_pcr && !tp->pcr &&
727 	    !tp->max_pcr)
728 		return -EINVAL;
729 	if (tp->min_pcr == ATM_MAX_PCR)
730 		return -EINVAL;
731 	if (tp->min_pcr && tp->max_pcr && tp->max_pcr != ATM_MAX_PCR &&
732 	    tp->min_pcr > tp->max_pcr)
733 		return -EINVAL;
734 	/*
735 	 * We allow pcr to be outside [min_pcr,max_pcr], because later
736 	 * adjustment may still push it in the valid range.
737 	 */
738 	return 0;
739 }
740 
741 static int check_qos(const struct atm_qos *qos)
742 {
743 	int error;
744 
745 	if (!qos->txtp.traffic_class && !qos->rxtp.traffic_class)
746 		return -EINVAL;
747 	if (qos->txtp.traffic_class != qos->rxtp.traffic_class &&
748 	    qos->txtp.traffic_class && qos->rxtp.traffic_class &&
749 	    qos->txtp.traffic_class != ATM_ANYCLASS &&
750 	    qos->rxtp.traffic_class != ATM_ANYCLASS)
751 		return -EINVAL;
752 	error = check_tp(&qos->txtp);
753 	if (error)
754 		return error;
755 	return check_tp(&qos->rxtp);
756 }
757 
758 int vcc_setsockopt(struct socket *sock, int level, int optname,
759 		   sockptr_t optval, unsigned int optlen)
760 {
761 	struct atm_vcc *vcc;
762 	unsigned long value;
763 	int error;
764 
765 	if (__SO_LEVEL_MATCH(optname, level) && optlen != __SO_SIZE(optname))
766 		return -EINVAL;
767 
768 	vcc = ATM_SD(sock);
769 	switch (optname) {
770 	case SO_ATMQOS:
771 	{
772 		struct atm_qos qos;
773 
774 		if (copy_from_sockptr(&qos, optval, sizeof(qos)))
775 			return -EFAULT;
776 		error = check_qos(&qos);
777 		if (error)
778 			return error;
779 		if (sock->state == SS_CONNECTED)
780 			return atm_change_qos(vcc, &qos);
781 		if (sock->state != SS_UNCONNECTED)
782 			return -EBADFD;
783 		vcc->qos = qos;
784 		set_bit(ATM_VF_HASQOS, &vcc->flags);
785 		return 0;
786 	}
787 	case SO_SETCLP:
788 		if (copy_from_sockptr(&value, optval, sizeof(value)))
789 			return -EFAULT;
790 		if (value)
791 			vcc->atm_options |= ATM_ATMOPT_CLP;
792 		else
793 			vcc->atm_options &= ~ATM_ATMOPT_CLP;
794 		return 0;
795 	default:
796 		return -EINVAL;
797 	}
798 }
799 
800 int vcc_getsockopt(struct socket *sock, int level, int optname,
801 		   sockopt_t *opt)
802 {
803 	struct atm_vcc *vcc;
804 	int val;
805 	int len;
806 
807 	len = opt->optlen;
808 	if (__SO_LEVEL_MATCH(optname, level) && len != __SO_SIZE(optname))
809 		return -EINVAL;
810 
811 	vcc = ATM_SD(sock);
812 	switch (optname) {
813 	case SO_ATMQOS:
814 		if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
815 			return -EINVAL;
816 		return copy_to_iter(&vcc->qos, sizeof(vcc->qos),
817 				    &opt->iter_out) != sizeof(vcc->qos)
818 			? -EFAULT : 0;
819 	case SO_SETCLP:
820 		val = vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0;
821 		return copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
822 		       sizeof(val) ? -EFAULT : 0;
823 	case SO_ATMPVC:
824 	{
825 		struct sockaddr_atmpvc pvc;
826 
827 		if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
828 			return -ENOTCONN;
829 		memset(&pvc, 0, sizeof(pvc));
830 		pvc.sap_family = AF_ATMPVC;
831 		pvc.sap_addr.itf = vcc->dev->number;
832 		pvc.sap_addr.vpi = vcc->vpi;
833 		pvc.sap_addr.vci = vcc->vci;
834 		return copy_to_iter(&pvc, sizeof(pvc), &opt->iter_out) !=
835 		       sizeof(pvc) ? -EFAULT : 0;
836 	}
837 	default:
838 		return -EINVAL;
839 	}
840 }
841 
842 int register_atmdevice_notifier(struct notifier_block *nb)
843 {
844 	return atomic_notifier_chain_register(&atm_dev_notify_chain, nb);
845 }
846 EXPORT_SYMBOL_GPL(register_atmdevice_notifier);
847 
848 void unregister_atmdevice_notifier(struct notifier_block *nb)
849 {
850 	atomic_notifier_chain_unregister(&atm_dev_notify_chain, nb);
851 }
852 EXPORT_SYMBOL_GPL(unregister_atmdevice_notifier);
853 
854 static int __init atm_init(void)
855 {
856 	int error;
857 
858 	error = proto_register(&vcc_proto, 0);
859 	if (error < 0)
860 		goto out;
861 	error = atmpvc_init();
862 	if (error < 0) {
863 		pr_err("atmpvc_init() failed with %d\n", error);
864 		goto out_unregister_vcc_proto;
865 	}
866 	error = atmsvc_init();
867 	if (error < 0) {
868 		pr_err("atmsvc_init() failed with %d\n", error);
869 		goto out_atmpvc_exit;
870 	}
871 	error = atm_proc_init();
872 	if (error < 0) {
873 		pr_err("atm_proc_init() failed with %d\n", error);
874 		goto out_atmsvc_exit;
875 	}
876 	error = atm_sysfs_init();
877 	if (error < 0) {
878 		pr_err("atm_sysfs_init() failed with %d\n", error);
879 		goto out_atmproc_exit;
880 	}
881 out:
882 	return error;
883 out_atmproc_exit:
884 	atm_proc_exit();
885 out_atmsvc_exit:
886 	atmsvc_exit();
887 out_atmpvc_exit:
888 	atmpvc_exit();
889 out_unregister_vcc_proto:
890 	proto_unregister(&vcc_proto);
891 	goto out;
892 }
893 
894 static void __exit atm_exit(void)
895 {
896 	atm_proc_exit();
897 	atm_sysfs_exit();
898 	atmsvc_exit();
899 	atmpvc_exit();
900 	proto_unregister(&vcc_proto);
901 }
902 
903 subsys_initcall(atm_init);
904 
905 module_exit(atm_exit);
906 
907 MODULE_DESCRIPTION("Asynchronous Transfer Mode (ATM) networking core");
908 MODULE_LICENSE("GPL");
909 MODULE_ALIAS_NETPROTO(PF_ATMPVC);
910 MODULE_ALIAS_NETPROTO(PF_ATMSVC);
911