xref: /linux/net/atm/common.c (revision d755d45bc08a57a3b845b850f8760de922a499bf)
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 
34 struct hlist_head vcc_hash[VCC_HTABLE_SIZE];
35 EXPORT_SYMBOL(vcc_hash);
36 
37 DEFINE_RWLOCK(vcc_sklist_lock);
38 EXPORT_SYMBOL(vcc_sklist_lock);
39 
40 static ATOMIC_NOTIFIER_HEAD(atm_dev_notify_chain);
41 
42 static void __vcc_insert_socket(struct sock *sk)
43 {
44 	struct atm_vcc *vcc = atm_sk(sk);
45 	struct hlist_head *head = &vcc_hash[vcc->vci & (VCC_HTABLE_SIZE - 1)];
46 	sk->sk_hash = vcc->vci & (VCC_HTABLE_SIZE - 1);
47 	sk_add_node(sk, head);
48 }
49 
50 void vcc_insert_socket(struct sock *sk)
51 {
52 	write_lock_irq(&vcc_sklist_lock);
53 	__vcc_insert_socket(sk);
54 	write_unlock_irq(&vcc_sklist_lock);
55 }
56 EXPORT_SYMBOL(vcc_insert_socket);
57 
58 static void vcc_remove_socket(struct sock *sk)
59 {
60 	write_lock_irq(&vcc_sklist_lock);
61 	sk_del_node_init(sk);
62 	write_unlock_irq(&vcc_sklist_lock);
63 }
64 
65 static bool vcc_tx_ready(struct atm_vcc *vcc, unsigned int size)
66 {
67 	struct sock *sk = sk_atm(vcc);
68 
69 	if (sk_wmem_alloc_get(sk) && !atm_may_send(vcc, size)) {
70 		pr_debug("Sorry: wmem_alloc = %d, size = %d, sndbuf = %d\n",
71 			 sk_wmem_alloc_get(sk), size, sk->sk_sndbuf);
72 		return false;
73 	}
74 	return true;
75 }
76 
77 static void vcc_sock_destruct(struct sock *sk)
78 {
79 	if (atomic_read(&sk->sk_rmem_alloc))
80 		printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
81 		       __func__, atomic_read(&sk->sk_rmem_alloc));
82 
83 	if (refcount_read(&sk->sk_wmem_alloc))
84 		printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
85 		       __func__, refcount_read(&sk->sk_wmem_alloc));
86 }
87 
88 static void vcc_def_wakeup(struct sock *sk)
89 {
90 	struct socket_wq *wq;
91 
92 	rcu_read_lock();
93 	wq = rcu_dereference(sk->sk_wq);
94 	if (skwq_has_sleeper(wq))
95 		wake_up(&wq->wait);
96 	rcu_read_unlock();
97 }
98 
99 static inline int vcc_writable(struct sock *sk)
100 {
101 	struct atm_vcc *vcc = atm_sk(sk);
102 
103 	return (vcc->qos.txtp.max_sdu +
104 		refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
105 }
106 
107 static void vcc_write_space(struct sock *sk)
108 {
109 	struct socket_wq *wq;
110 
111 	rcu_read_lock();
112 
113 	if (vcc_writable(sk)) {
114 		wq = rcu_dereference(sk->sk_wq);
115 		if (skwq_has_sleeper(wq))
116 			wake_up_interruptible(&wq->wait);
117 
118 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
119 	}
120 
121 	rcu_read_unlock();
122 }
123 
124 static void vcc_release_cb(struct sock *sk)
125 {
126 	struct atm_vcc *vcc = atm_sk(sk);
127 
128 	if (vcc->release_cb)
129 		vcc->release_cb(vcc);
130 }
131 
132 static struct proto vcc_proto = {
133 	.name	  = "VCC",
134 	.owner	  = THIS_MODULE,
135 	.obj_size = sizeof(struct atm_vcc),
136 	.release_cb = vcc_release_cb,
137 };
138 
139 int vcc_create(struct net *net, struct socket *sock, int protocol, int family, int kern)
140 {
141 	struct sock *sk;
142 	struct atm_vcc *vcc;
143 
144 	sock->sk = NULL;
145 	if (sock->type == SOCK_STREAM)
146 		return -EINVAL;
147 	sk = sk_alloc(net, family, GFP_KERNEL, &vcc_proto, kern);
148 	if (!sk)
149 		return -ENOMEM;
150 	sock_init_data(sock, sk);
151 	sk->sk_state_change = vcc_def_wakeup;
152 	sk->sk_write_space = vcc_write_space;
153 
154 	vcc = atm_sk(sk);
155 	vcc->dev = NULL;
156 	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
157 	refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
158 	atomic_set(&sk->sk_rmem_alloc, 0);
159 	vcc->push = NULL;
160 	vcc->pop = NULL;
161 	vcc->owner = NULL;
162 	vcc->release_cb = NULL;
163 	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
164 	vcc->atm_options = vcc->aal_options = 0;
165 	sk->sk_destruct = vcc_sock_destruct;
166 	return 0;
167 }
168 
169 static void vcc_destroy_socket(struct sock *sk)
170 {
171 	struct atm_vcc *vcc = atm_sk(sk);
172 	struct sk_buff *skb;
173 
174 	set_bit(ATM_VF_CLOSE, &vcc->flags);
175 	clear_bit(ATM_VF_READY, &vcc->flags);
176 	if (vcc->dev && vcc->dev->ops->close)
177 		vcc->dev->ops->close(vcc);
178 	if (vcc->push)
179 		vcc->push(vcc, NULL); /* atmarpd has no push */
180 	module_put(vcc->owner);
181 
182 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
183 		atm_return(vcc, skb->truesize);
184 		kfree_skb(skb);
185 	}
186 
187 	if (vcc->dev && vcc->dev->ops->owner) {
188 		module_put(vcc->dev->ops->owner);
189 		atm_dev_put(vcc->dev);
190 	}
191 
192 	vcc_remove_socket(sk);
193 }
194 
195 int vcc_release(struct socket *sock)
196 {
197 	struct sock *sk = sock->sk;
198 
199 	if (sk) {
200 		lock_sock(sk);
201 		vcc_destroy_socket(sock->sk);
202 		release_sock(sk);
203 		sock_put(sk);
204 	}
205 
206 	return 0;
207 }
208 
209 void vcc_release_async(struct atm_vcc *vcc, int reply)
210 {
211 	struct sock *sk = sk_atm(vcc);
212 
213 	set_bit(ATM_VF_CLOSE, &vcc->flags);
214 	sk->sk_shutdown |= RCV_SHUTDOWN;
215 	sk->sk_err = -reply;
216 	sk->sk_state_change(sk);
217 }
218 EXPORT_SYMBOL(vcc_release_async);
219 
220 void vcc_process_recv_queue(struct atm_vcc *vcc)
221 {
222 	struct sk_buff_head queue, *rq;
223 	struct sk_buff *skb, *tmp;
224 	unsigned long flags;
225 
226 	__skb_queue_head_init(&queue);
227 	rq = &sk_atm(vcc)->sk_receive_queue;
228 
229 	spin_lock_irqsave(&rq->lock, flags);
230 	skb_queue_splice_init(rq, &queue);
231 	spin_unlock_irqrestore(&rq->lock, flags);
232 
233 	skb_queue_walk_safe(&queue, skb, tmp) {
234 		__skb_unlink(skb, &queue);
235 		vcc->push(vcc, skb);
236 	}
237 }
238 EXPORT_SYMBOL(vcc_process_recv_queue);
239 
240 void atm_dev_signal_change(struct atm_dev *dev, char signal)
241 {
242 	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
243 		__func__, signal, dev, dev->number, dev->signal);
244 
245 	/* atm driver sending invalid signal */
246 	WARN_ON(signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND);
247 
248 	if (dev->signal == signal)
249 		return; /* no change */
250 
251 	dev->signal = signal;
252 
253 	atomic_notifier_call_chain(&atm_dev_notify_chain, signal, dev);
254 }
255 EXPORT_SYMBOL(atm_dev_signal_change);
256 
257 void atm_dev_release_vccs(struct atm_dev *dev)
258 {
259 	int i;
260 
261 	write_lock_irq(&vcc_sklist_lock);
262 	for (i = 0; i < VCC_HTABLE_SIZE; i++) {
263 		struct hlist_head *head = &vcc_hash[i];
264 		struct hlist_node *tmp;
265 		struct sock *s;
266 		struct atm_vcc *vcc;
267 
268 		sk_for_each_safe(s, tmp, head) {
269 			vcc = atm_sk(s);
270 			if (vcc->dev == dev) {
271 				vcc_release_async(vcc, -EPIPE);
272 				sk_del_node_init(s);
273 			}
274 		}
275 	}
276 	write_unlock_irq(&vcc_sklist_lock);
277 }
278 EXPORT_SYMBOL(atm_dev_release_vccs);
279 
280 static int adjust_tp(struct atm_trafprm *tp, unsigned char aal)
281 {
282 	int max_sdu;
283 
284 	if (!tp->traffic_class)
285 		return 0;
286 	switch (aal) {
287 	case ATM_AAL0:
288 		max_sdu = ATM_CELL_SIZE-1;
289 		break;
290 	default:
291 		pr_warn("AAL problems ... (%d)\n", aal);
292 		fallthrough;
293 	case ATM_AAL5:
294 		max_sdu = ATM_MAX_AAL5_PDU;
295 	}
296 	if (!tp->max_sdu)
297 		tp->max_sdu = max_sdu;
298 	else if (tp->max_sdu > max_sdu)
299 		return -EINVAL;
300 	if (!tp->max_cdv)
301 		tp->max_cdv = ATM_MAX_CDV;
302 	return 0;
303 }
304 
305 static int check_ci(const struct atm_vcc *vcc, short vpi, int vci)
306 {
307 	struct hlist_head *head = &vcc_hash[vci & (VCC_HTABLE_SIZE - 1)];
308 	struct sock *s;
309 	struct atm_vcc *walk;
310 
311 	sk_for_each(s, head) {
312 		walk = atm_sk(s);
313 		if (walk->dev != vcc->dev)
314 			continue;
315 		if (test_bit(ATM_VF_ADDR, &walk->flags) && walk->vpi == vpi &&
316 		    walk->vci == vci && ((walk->qos.txtp.traffic_class !=
317 		    ATM_NONE && vcc->qos.txtp.traffic_class != ATM_NONE) ||
318 		    (walk->qos.rxtp.traffic_class != ATM_NONE &&
319 		    vcc->qos.rxtp.traffic_class != ATM_NONE)))
320 			return -EADDRINUSE;
321 	}
322 
323 	/* allow VCCs with same VPI/VCI iff they don't collide on
324 	   TX/RX (but we may refuse such sharing for other reasons,
325 	   e.g. if protocol requires to have both channels) */
326 
327 	return 0;
328 }
329 
330 static int find_ci(const struct atm_vcc *vcc, short *vpi, int *vci)
331 {
332 	static short p;        /* poor man's per-device cache */
333 	static int c;
334 	short old_p;
335 	int old_c;
336 	int err;
337 
338 	if (*vpi != ATM_VPI_ANY && *vci != ATM_VCI_ANY) {
339 		err = check_ci(vcc, *vpi, *vci);
340 		return err;
341 	}
342 	/* last scan may have left values out of bounds for current device */
343 	if (*vpi != ATM_VPI_ANY)
344 		p = *vpi;
345 	else if (p >= 1 << vcc->dev->ci_range.vpi_bits)
346 		p = 0;
347 	if (*vci != ATM_VCI_ANY)
348 		c = *vci;
349 	else if (c < ATM_NOT_RSV_VCI || c >= 1 << vcc->dev->ci_range.vci_bits)
350 			c = ATM_NOT_RSV_VCI;
351 	old_p = p;
352 	old_c = c;
353 	do {
354 		if (!check_ci(vcc, p, c)) {
355 			*vpi = p;
356 			*vci = c;
357 			return 0;
358 		}
359 		if (*vci == ATM_VCI_ANY) {
360 			c++;
361 			if (c >= 1 << vcc->dev->ci_range.vci_bits)
362 				c = ATM_NOT_RSV_VCI;
363 		}
364 		if ((c == ATM_NOT_RSV_VCI || *vci != ATM_VCI_ANY) &&
365 		    *vpi == ATM_VPI_ANY) {
366 			p++;
367 			if (p >= 1 << vcc->dev->ci_range.vpi_bits)
368 				p = 0;
369 		}
370 	} while (old_p != p || old_c != c);
371 	return -EADDRINUSE;
372 }
373 
374 static int __vcc_connect(struct atm_vcc *vcc, struct atm_dev *dev, short vpi,
375 			 int vci)
376 {
377 	struct sock *sk = sk_atm(vcc);
378 	int error;
379 
380 	if ((vpi != ATM_VPI_UNSPEC && vpi != ATM_VPI_ANY &&
381 	    vpi >> dev->ci_range.vpi_bits) || (vci != ATM_VCI_UNSPEC &&
382 	    vci != ATM_VCI_ANY && vci >> dev->ci_range.vci_bits))
383 		return -EINVAL;
384 	if (vci > 0 && vci < ATM_NOT_RSV_VCI && !capable(CAP_NET_BIND_SERVICE))
385 		return -EPERM;
386 	error = -ENODEV;
387 	if (!try_module_get(dev->ops->owner))
388 		return error;
389 	vcc->dev = dev;
390 	write_lock_irq(&vcc_sklist_lock);
391 	if (test_bit(ATM_DF_REMOVED, &dev->flags) ||
392 	    (error = find_ci(vcc, &vpi, &vci))) {
393 		write_unlock_irq(&vcc_sklist_lock);
394 		goto fail_module_put;
395 	}
396 	vcc->vpi = vpi;
397 	vcc->vci = vci;
398 	__vcc_insert_socket(sk);
399 	write_unlock_irq(&vcc_sklist_lock);
400 	switch (vcc->qos.aal) {
401 	case ATM_AAL0:
402 		error = atm_init_aal0(vcc);
403 		vcc->stats = &dev->stats.aal0;
404 		break;
405 	case ATM_NO_AAL:
406 		/* ATM_AAL5 is also used in the "0 for default" case */
407 		vcc->qos.aal = ATM_AAL5;
408 		fallthrough;
409 	case ATM_AAL5:
410 		error = atm_init_aal5(vcc);
411 		vcc->stats = &dev->stats.aal5;
412 		break;
413 	default:
414 		error = -EPROTOTYPE;
415 	}
416 	if (!error)
417 		error = adjust_tp(&vcc->qos.txtp, vcc->qos.aal);
418 	if (!error)
419 		error = adjust_tp(&vcc->qos.rxtp, vcc->qos.aal);
420 	if (error)
421 		goto fail;
422 	pr_debug("VCC %d.%d, AAL %d\n", vpi, vci, vcc->qos.aal);
423 	pr_debug("  TX: %d, PCR %d..%d, SDU %d\n",
424 		 vcc->qos.txtp.traffic_class,
425 		 vcc->qos.txtp.min_pcr,
426 		 vcc->qos.txtp.max_pcr,
427 		 vcc->qos.txtp.max_sdu);
428 	pr_debug("  RX: %d, PCR %d..%d, SDU %d\n",
429 		 vcc->qos.rxtp.traffic_class,
430 		 vcc->qos.rxtp.min_pcr,
431 		 vcc->qos.rxtp.max_pcr,
432 		 vcc->qos.rxtp.max_sdu);
433 
434 	if (dev->ops->open) {
435 		error = dev->ops->open(vcc);
436 		if (error)
437 			goto fail;
438 	}
439 	return 0;
440 
441 fail:
442 	vcc_remove_socket(sk);
443 fail_module_put:
444 	module_put(dev->ops->owner);
445 	/* ensure we get dev module ref count correct */
446 	vcc->dev = NULL;
447 	return error;
448 }
449 
450 int vcc_connect(struct socket *sock, int itf, short vpi, int vci)
451 {
452 	struct atm_dev *dev;
453 	struct atm_vcc *vcc = ATM_SD(sock);
454 	int error;
455 
456 	pr_debug("(vpi %d, vci %d)\n", vpi, vci);
457 	if (sock->state == SS_CONNECTED)
458 		return -EISCONN;
459 	if (sock->state != SS_UNCONNECTED)
460 		return -EINVAL;
461 	if (!(vpi || vci))
462 		return -EINVAL;
463 
464 	if (vpi != ATM_VPI_UNSPEC && vci != ATM_VCI_UNSPEC)
465 		clear_bit(ATM_VF_PARTIAL, &vcc->flags);
466 	else
467 		if (test_bit(ATM_VF_PARTIAL, &vcc->flags))
468 			return -EINVAL;
469 	pr_debug("(TX: cl %d,bw %d-%d,sdu %d; "
470 		 "RX: cl %d,bw %d-%d,sdu %d,AAL %s%d)\n",
471 		 vcc->qos.txtp.traffic_class, vcc->qos.txtp.min_pcr,
472 		 vcc->qos.txtp.max_pcr, vcc->qos.txtp.max_sdu,
473 		 vcc->qos.rxtp.traffic_class, vcc->qos.rxtp.min_pcr,
474 		 vcc->qos.rxtp.max_pcr, vcc->qos.rxtp.max_sdu,
475 		 vcc->qos.aal == ATM_AAL5 ? "" :
476 		 vcc->qos.aal == ATM_AAL0 ? "" : " ??? code ",
477 		 vcc->qos.aal == ATM_AAL0 ? 0 : vcc->qos.aal);
478 	if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
479 		return -EBADFD;
480 	if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
481 	    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS)
482 		return -EINVAL;
483 	if (likely(itf != ATM_ITF_ANY)) {
484 		dev = try_then_request_module(atm_dev_lookup(itf),
485 					      "atm-device-%d", itf);
486 	} else {
487 		dev = NULL;
488 		mutex_lock(&atm_dev_mutex);
489 		if (!list_empty(&atm_devs)) {
490 			dev = list_entry(atm_devs.next,
491 					 struct atm_dev, dev_list);
492 			atm_dev_hold(dev);
493 		}
494 		mutex_unlock(&atm_dev_mutex);
495 	}
496 	if (!dev)
497 		return -ENODEV;
498 	error = __vcc_connect(vcc, dev, vpi, vci);
499 	if (error) {
500 		atm_dev_put(dev);
501 		return error;
502 	}
503 	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC)
504 		set_bit(ATM_VF_PARTIAL, &vcc->flags);
505 	if (test_bit(ATM_VF_READY, &ATM_SD(sock)->flags))
506 		sock->state = SS_CONNECTED;
507 	return 0;
508 }
509 
510 int vcc_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
511 		int flags)
512 {
513 	struct sock *sk = sock->sk;
514 	struct atm_vcc *vcc;
515 	struct sk_buff *skb;
516 	int copied, error = -EINVAL;
517 
518 	if (sock->state != SS_CONNECTED)
519 		return -ENOTCONN;
520 
521 	/* only handle MSG_DONTWAIT and MSG_PEEK */
522 	if (flags & ~(MSG_DONTWAIT | MSG_PEEK))
523 		return -EOPNOTSUPP;
524 
525 	vcc = ATM_SD(sock);
526 	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
527 	    !test_bit(ATM_VF_READY, &vcc->flags))
528 		return 0;
529 
530 	skb = skb_recv_datagram(sk, flags, &error);
531 	if (!skb)
532 		return error;
533 
534 	copied = skb->len;
535 	if (copied > size) {
536 		copied = size;
537 		msg->msg_flags |= MSG_TRUNC;
538 	}
539 
540 	error = skb_copy_datagram_msg(skb, 0, msg, copied);
541 	if (error)
542 		return error;
543 	sock_recv_cmsgs(msg, sk, skb);
544 
545 	if (!(flags & MSG_PEEK)) {
546 		pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc),
547 			 skb->truesize);
548 		atm_return(vcc, skb->truesize);
549 	}
550 
551 	skb_free_datagram(sk, skb);
552 	return copied;
553 }
554 
555 int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
556 {
557 	struct sock *sk = sock->sk;
558 	DEFINE_WAIT(wait);
559 	struct atm_vcc *vcc;
560 	struct sk_buff *skb;
561 	int eff, error;
562 
563 	lock_sock(sk);
564 	if (sock->state != SS_CONNECTED) {
565 		error = -ENOTCONN;
566 		goto out;
567 	}
568 	if (m->msg_name) {
569 		error = -EISCONN;
570 		goto out;
571 	}
572 	vcc = ATM_SD(sock);
573 	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
574 	    !test_bit(ATM_VF_READY, &vcc->flags)) {
575 		error = -EPIPE;
576 		send_sig(SIGPIPE, current, 0);
577 		goto out;
578 	}
579 	if (!size) {
580 		error = 0;
581 		goto out;
582 	}
583 	if (size > vcc->qos.txtp.max_sdu) {
584 		error = -EMSGSIZE;
585 		goto out;
586 	}
587 
588 	eff = (size+3) & ~3; /* align to word boundary */
589 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
590 	error = 0;
591 	while (!vcc_tx_ready(vcc, eff)) {
592 		if (m->msg_flags & MSG_DONTWAIT) {
593 			error = -EAGAIN;
594 			break;
595 		}
596 		schedule();
597 		if (signal_pending(current)) {
598 			error = -ERESTARTSYS;
599 			break;
600 		}
601 		if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
602 		    !test_bit(ATM_VF_READY, &vcc->flags)) {
603 			error = -EPIPE;
604 			send_sig(SIGPIPE, current, 0);
605 			break;
606 		}
607 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
608 	}
609 	finish_wait(sk_sleep(sk), &wait);
610 	if (error)
611 		goto out;
612 
613 	skb = alloc_skb(eff, GFP_KERNEL);
614 	if (!skb) {
615 		error = -ENOMEM;
616 		goto out;
617 	}
618 	pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
619 	atm_account_tx(vcc, skb);
620 
621 	skb->dev = NULL; /* for paths shared with net_device interfaces */
622 	if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
623 		error = -EFAULT;
624 		goto free_skb;
625 	}
626 	if (eff != size)
627 		memset(skb->data + size, 0, eff-size);
628 
629 	error = vcc->dev->ops->send(vcc, skb);
630 	error = error ? error : size;
631 out:
632 	release_sock(sk);
633 	return error;
634 free_skb:
635 	atm_return_tx(vcc, skb);
636 	kfree_skb(skb);
637 	goto out;
638 }
639 
640 __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
641 {
642 	struct sock *sk = sock->sk;
643 	struct atm_vcc *vcc;
644 	__poll_t mask;
645 
646 	sock_poll_wait(file, sock, wait);
647 	mask = 0;
648 
649 	vcc = ATM_SD(sock);
650 
651 	/* exceptional events */
652 	if (sk->sk_err)
653 		mask = EPOLLERR;
654 
655 	if (test_bit(ATM_VF_CLOSE, &vcc->flags))
656 		mask |= EPOLLHUP;
657 
658 	/* readable? */
659 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
660 		mask |= EPOLLIN | EPOLLRDNORM;
661 
662 	/* writable? */
663 	if (vcc->qos.txtp.traffic_class != ATM_NONE &&
664 	    vcc_writable(sk))
665 		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
666 
667 	return mask;
668 }
669 
670 static int check_tp(const struct atm_trafprm *tp)
671 {
672 	/* @@@ Should be merged with adjust_tp */
673 	if (tp->traffic_class > ATM_ANYCLASS)
674 		return -EINVAL;
675 	if (!tp->traffic_class || tp->traffic_class == ATM_ANYCLASS)
676 		return 0;
677 	if (tp->traffic_class != ATM_UBR && !tp->min_pcr && !tp->pcr &&
678 	    !tp->max_pcr)
679 		return -EINVAL;
680 	if (tp->min_pcr == ATM_MAX_PCR)
681 		return -EINVAL;
682 	if (tp->min_pcr && tp->max_pcr && tp->max_pcr != ATM_MAX_PCR &&
683 	    tp->min_pcr > tp->max_pcr)
684 		return -EINVAL;
685 	/*
686 	 * We allow pcr to be outside [min_pcr,max_pcr], because later
687 	 * adjustment may still push it in the valid range.
688 	 */
689 	return 0;
690 }
691 
692 static int check_qos(const struct atm_qos *qos)
693 {
694 	int error;
695 
696 	if (!qos->txtp.traffic_class && !qos->rxtp.traffic_class)
697 		return -EINVAL;
698 	if (qos->txtp.traffic_class != qos->rxtp.traffic_class &&
699 	    qos->txtp.traffic_class && qos->rxtp.traffic_class &&
700 	    qos->txtp.traffic_class != ATM_ANYCLASS &&
701 	    qos->rxtp.traffic_class != ATM_ANYCLASS)
702 		return -EINVAL;
703 	error = check_tp(&qos->txtp);
704 	if (error)
705 		return error;
706 	return check_tp(&qos->rxtp);
707 }
708 
709 int vcc_setsockopt(struct socket *sock, int level, int optname,
710 		   sockptr_t optval, unsigned int optlen)
711 {
712 	struct atm_vcc *vcc;
713 	unsigned long value;
714 	int error;
715 
716 	if (__SO_LEVEL_MATCH(optname, level) && optlen != __SO_SIZE(optname))
717 		return -EINVAL;
718 
719 	vcc = ATM_SD(sock);
720 	switch (optname) {
721 	case SO_ATMQOS:
722 	{
723 		struct atm_qos qos;
724 
725 		if (copy_from_sockptr(&qos, optval, sizeof(qos)))
726 			return -EFAULT;
727 		error = check_qos(&qos);
728 		if (error)
729 			return error;
730 		/* QoS cannot be renegotiated on an already connected VCC. */
731 		if (sock->state == SS_CONNECTED)
732 			return -EOPNOTSUPP;
733 		if (sock->state != SS_UNCONNECTED)
734 			return -EBADFD;
735 		vcc->qos = qos;
736 		set_bit(ATM_VF_HASQOS, &vcc->flags);
737 		return 0;
738 	}
739 	case SO_SETCLP:
740 		if (copy_from_sockptr(&value, optval, sizeof(value)))
741 			return -EFAULT;
742 		if (value)
743 			vcc->atm_options |= ATM_ATMOPT_CLP;
744 		else
745 			vcc->atm_options &= ~ATM_ATMOPT_CLP;
746 		return 0;
747 	default:
748 		return -EINVAL;
749 	}
750 }
751 
752 int vcc_getsockopt(struct socket *sock, int level, int optname,
753 		   sockopt_t *opt)
754 {
755 	struct atm_vcc *vcc;
756 	int val;
757 	int len;
758 
759 	len = opt->optlen;
760 	if (__SO_LEVEL_MATCH(optname, level) && len != __SO_SIZE(optname))
761 		return -EINVAL;
762 
763 	vcc = ATM_SD(sock);
764 	switch (optname) {
765 	case SO_ATMQOS:
766 		if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
767 			return -EINVAL;
768 		return copy_to_iter(&vcc->qos, sizeof(vcc->qos),
769 				    &opt->iter_out) != sizeof(vcc->qos)
770 			? -EFAULT : 0;
771 	case SO_SETCLP:
772 		val = vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0;
773 		return copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
774 		       sizeof(val) ? -EFAULT : 0;
775 	case SO_ATMPVC:
776 	{
777 		struct sockaddr_atmpvc pvc;
778 
779 		if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
780 			return -ENOTCONN;
781 		memset(&pvc, 0, sizeof(pvc));
782 		pvc.sap_family = AF_ATMPVC;
783 		pvc.sap_addr.itf = vcc->dev->number;
784 		pvc.sap_addr.vpi = vcc->vpi;
785 		pvc.sap_addr.vci = vcc->vci;
786 		return copy_to_iter(&pvc, sizeof(pvc), &opt->iter_out) !=
787 		       sizeof(pvc) ? -EFAULT : 0;
788 	}
789 	default:
790 		return -EINVAL;
791 	}
792 }
793 
794 int register_atmdevice_notifier(struct notifier_block *nb)
795 {
796 	return atomic_notifier_chain_register(&atm_dev_notify_chain, nb);
797 }
798 EXPORT_SYMBOL_GPL(register_atmdevice_notifier);
799 
800 void unregister_atmdevice_notifier(struct notifier_block *nb)
801 {
802 	atomic_notifier_chain_unregister(&atm_dev_notify_chain, nb);
803 }
804 EXPORT_SYMBOL_GPL(unregister_atmdevice_notifier);
805 
806 static int __init atm_init(void)
807 {
808 	int error;
809 
810 	error = proto_register(&vcc_proto, 0);
811 	if (error < 0)
812 		goto out;
813 	error = atmpvc_init();
814 	if (error < 0) {
815 		pr_err("atmpvc_init() failed with %d\n", error);
816 		goto out_unregister_vcc_proto;
817 	}
818 	error = atm_proc_init();
819 	if (error < 0) {
820 		pr_err("atm_proc_init() failed with %d\n", error);
821 		goto out_atmpvc_exit;
822 	}
823 	error = atm_sysfs_init();
824 	if (error < 0) {
825 		pr_err("atm_sysfs_init() failed with %d\n", error);
826 		goto out_atmproc_exit;
827 	}
828 out:
829 	return error;
830 out_atmproc_exit:
831 	atm_proc_exit();
832 out_atmpvc_exit:
833 	atmpvc_exit();
834 out_unregister_vcc_proto:
835 	proto_unregister(&vcc_proto);
836 	goto out;
837 }
838 
839 static void __exit atm_exit(void)
840 {
841 	atm_proc_exit();
842 	atm_sysfs_exit();
843 	atmpvc_exit();
844 	proto_unregister(&vcc_proto);
845 }
846 
847 subsys_initcall(atm_init);
848 
849 module_exit(atm_exit);
850 
851 MODULE_DESCRIPTION("Asynchronous Transfer Mode (ATM) networking core");
852 MODULE_LICENSE("GPL");
853 MODULE_ALIAS_NETPROTO(PF_ATMPVC);
854