// SPDX-License-Identifier: GPL-2.0-only
/* net/atm/common.c - ATM sockets (common part for PVC and SVC) */

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/net.h>		/* struct socket, struct proto_ops */
#include <linux/atm.h>		/* ATM stuff */
#include <linux/atmdev.h>
#include <linux/socket.h>	/* SOL_SOCKET */
#include <linux/errno.h>	/* error codes */
#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/sched/signal.h>
#include <linux/time64.h>	/* 64-bit time for seconds */
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/sock.h>		/* struct sock */
#include <linux/uaccess.h>
#include <linux/poll.h>
#include <linux/uio.h>

#include <linux/atomic.h>

#include "resources.h"		/* atm_find_dev */
#include "common.h"		/* prototypes */
#include "protocols.h"		/* atm_init_<transport> */

struct hlist_head vcc_hash[VCC_HTABLE_SIZE];
EXPORT_SYMBOL(vcc_hash);

DEFINE_RWLOCK(vcc_sklist_lock);
EXPORT_SYMBOL(vcc_sklist_lock);

static ATOMIC_NOTIFIER_HEAD(atm_dev_notify_chain);

static void __vcc_insert_socket(struct sock *sk)
{
	struct atm_vcc *vcc = atm_sk(sk);
	struct hlist_head *head = &vcc_hash[vcc->vci & (VCC_HTABLE_SIZE - 1)];
	sk->sk_hash = vcc->vci & (VCC_HTABLE_SIZE - 1);
	sk_add_node(sk, head);
}

void vcc_insert_socket(struct sock *sk)
{
	write_lock_irq(&vcc_sklist_lock);
	__vcc_insert_socket(sk);
	write_unlock_irq(&vcc_sklist_lock);
}
EXPORT_SYMBOL(vcc_insert_socket);

static void vcc_remove_socket(struct sock *sk)
{
	write_lock_irq(&vcc_sklist_lock);
	sk_del_node_init(sk);
	write_unlock_irq(&vcc_sklist_lock);
}

static bool vcc_tx_ready(struct atm_vcc *vcc, unsigned int size)
{
	struct sock *sk = sk_atm(vcc);

	if (sk_wmem_alloc_get(sk) && !atm_may_send(vcc, size)) {
		pr_debug("Sorry: wmem_alloc = %d, size = %d, sndbuf = %d\n",
			 sk_wmem_alloc_get(sk), size, sk->sk_sndbuf);
		return false;
	}
	return true;
}

static void vcc_sock_destruct(struct sock *sk)
{
	if (atomic_read(&sk->sk_rmem_alloc))
		printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
		       __func__, atomic_read(&sk->sk_rmem_alloc));

	if (refcount_read(&sk->sk_wmem_alloc))
		printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
		       __func__, refcount_read(&sk->sk_wmem_alloc));
}

static void vcc_def_wakeup(struct sock *sk)
{
	struct socket_wq *wq;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
	if (skwq_has_sleeper(wq))
		wake_up(&wq->wait);
	rcu_read_unlock();
}

static inline int vcc_writable(struct sock *sk)
{
	struct atm_vcc *vcc = atm_sk(sk);

	return (vcc->qos.txtp.max_sdu +
		refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
}

static void vcc_write_space(struct sock *sk)
{
	struct socket_wq *wq;

	rcu_read_lock();

	if (vcc_writable(sk)) {
		wq = rcu_dereference(sk->sk_wq);
		if (skwq_has_sleeper(wq))
			wake_up_interruptible(&wq->wait);

		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
	}

	rcu_read_unlock();
}

static void vcc_release_cb(struct sock *sk)
{
	struct atm_vcc *vcc = atm_sk(sk);

	if (vcc->release_cb)
		vcc->release_cb(vcc);
}

static struct proto vcc_proto = {
	.name	  = "VCC",
	.owner	  = THIS_MODULE,
	.obj_size = sizeof(struct atm_vcc),
	.release_cb = vcc_release_cb,
};

int vcc_create(struct net *net, struct socket *sock, int protocol, int family, int kern)
{
	struct sock *sk;
	struct atm_vcc *vcc;

	sock->sk = NULL;
	if (sock->type == SOCK_STREAM)
		return -EINVAL;
	sk = sk_alloc(net, family, GFP_KERNEL, &vcc_proto, kern);
	if (!sk)
		return -ENOMEM;
	sock_init_data(sock, sk);
	sk->sk_state_change = vcc_def_wakeup;
	sk->sk_write_space = vcc_write_space;

	vcc = atm_sk(sk);
	vcc->dev = NULL;
	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
	refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
	atomic_set(&sk->sk_rmem_alloc, 0);
	vcc->push = NULL;
	vcc->pop = NULL;
	vcc->owner = NULL;
	vcc->release_cb = NULL;
	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
	vcc->atm_options = vcc->aal_options = 0;
	sk->sk_destruct = vcc_sock_destruct;
	return 0;
}

static void vcc_destroy_socket(struct sock *sk)
{
	struct atm_vcc *vcc = atm_sk(sk);
	struct sk_buff *skb;

	set_bit(ATM_VF_CLOSE, &vcc->flags);
	clear_bit(ATM_VF_READY, &vcc->flags);
	if (vcc->dev && vcc->dev->ops->close)
		vcc->dev->ops->close(vcc);
	if (vcc->push)
		vcc->push(vcc, NULL); /* atmarpd has no push */
	module_put(vcc->owner);

	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
		atm_return(vcc, skb->truesize);
		kfree_skb(skb);
	}

	if (vcc->dev && vcc->dev->ops->owner) {
		module_put(vcc->dev->ops->owner);
		atm_dev_put(vcc->dev);
	}

	vcc_remove_socket(sk);
}

int vcc_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	if (sk) {
		lock_sock(sk);
		vcc_destroy_socket(sock->sk);
		release_sock(sk);
		sock_put(sk);
	}

	return 0;
}

void vcc_release_async(struct atm_vcc *vcc, int reply)
{
	struct sock *sk = sk_atm(vcc);

	set_bit(ATM_VF_CLOSE, &vcc->flags);
	sk->sk_shutdown |= RCV_SHUTDOWN;
	sk->sk_err = -reply;
	sk->sk_state_change(sk);
}
EXPORT_SYMBOL(vcc_release_async);

void vcc_process_recv_queue(struct atm_vcc *vcc)
{
	struct sk_buff_head queue, *rq;
	struct sk_buff *skb, *tmp;
	unsigned long flags;

	__skb_queue_head_init(&queue);
	rq = &sk_atm(vcc)->sk_receive_queue;

	spin_lock_irqsave(&rq->lock, flags);
	skb_queue_splice_init(rq, &queue);
	spin_unlock_irqrestore(&rq->lock, flags);

	skb_queue_walk_safe(&queue, skb, tmp) {
		__skb_unlink(skb, &queue);
		vcc->push(vcc, skb);
	}
}
EXPORT_SYMBOL(vcc_process_recv_queue);

void atm_dev_signal_change(struct atm_dev *dev, char signal)
{
	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
		__func__, signal, dev, dev->number, dev->signal);

	/* atm driver sending invalid signal */
	WARN_ON(signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND);

	if (dev->signal == signal)
		return; /* no change */

	dev->signal = signal;

	atomic_notifier_call_chain(&atm_dev_notify_chain, signal, dev);
}
EXPORT_SYMBOL(atm_dev_signal_change);

void atm_dev_release_vccs(struct atm_dev *dev)
{
	int i;

	write_lock_irq(&vcc_sklist_lock);
	for (i = 0; i < VCC_HTABLE_SIZE; i++) {
		struct hlist_head *head = &vcc_hash[i];
		struct hlist_node *tmp;
		struct sock *s;
		struct atm_vcc *vcc;

		sk_for_each_safe(s, tmp, head) {
			vcc = atm_sk(s);
			if (vcc->dev == dev) {
				vcc_release_async(vcc, -EPIPE);
				sk_del_node_init(s);
			}
		}
	}
	write_unlock_irq(&vcc_sklist_lock);
}
EXPORT_SYMBOL(atm_dev_release_vccs);

static int adjust_tp(struct atm_trafprm *tp, unsigned char aal)
{
	int max_sdu;

	if (!tp->traffic_class)
		return 0;
	switch (aal) {
	case ATM_AAL0:
		max_sdu = ATM_CELL_SIZE-1;
		break;
	default:
		pr_warn("AAL problems ... (%d)\n", aal);
		fallthrough;
	case ATM_AAL5:
		max_sdu = ATM_MAX_AAL5_PDU;
	}
	if (!tp->max_sdu)
		tp->max_sdu = max_sdu;
	else if (tp->max_sdu > max_sdu)
		return -EINVAL;
	if (!tp->max_cdv)
		tp->max_cdv = ATM_MAX_CDV;
	return 0;
}

static int check_ci(const struct atm_vcc *vcc, short vpi, int vci)
{
	struct hlist_head *head = &vcc_hash[vci & (VCC_HTABLE_SIZE - 1)];
	struct sock *s;
	struct atm_vcc *walk;

	sk_for_each(s, head) {
		walk = atm_sk(s);
		if (walk->dev != vcc->dev)
			continue;
		if (test_bit(ATM_VF_ADDR, &walk->flags) && walk->vpi == vpi &&
		    walk->vci == vci && ((walk->qos.txtp.traffic_class !=
		    ATM_NONE && vcc->qos.txtp.traffic_class != ATM_NONE) ||
		    (walk->qos.rxtp.traffic_class != ATM_NONE &&
		    vcc->qos.rxtp.traffic_class != ATM_NONE)))
			return -EADDRINUSE;
	}

	/* allow VCCs with same VPI/VCI iff they don't collide on
	   TX/RX (but we may refuse such sharing for other reasons,
	   e.g. if protocol requires to have both channels) */

	return 0;
}

static int find_ci(const struct atm_vcc *vcc, short *vpi, int *vci)
{
	static short p;        /* poor man's per-device cache */
	static int c;
	short old_p;
	int old_c;
	int err;

	if (*vpi != ATM_VPI_ANY && *vci != ATM_VCI_ANY) {
		err = check_ci(vcc, *vpi, *vci);
		return err;
	}
	/* last scan may have left values out of bounds for current device */
	if (*vpi != ATM_VPI_ANY)
		p = *vpi;
	else if (p >= 1 << vcc->dev->ci_range.vpi_bits)
		p = 0;
	if (*vci != ATM_VCI_ANY)
		c = *vci;
	else if (c < ATM_NOT_RSV_VCI || c >= 1 << vcc->dev->ci_range.vci_bits)
			c = ATM_NOT_RSV_VCI;
	old_p = p;
	old_c = c;
	do {
		if (!check_ci(vcc, p, c)) {
			*vpi = p;
			*vci = c;
			return 0;
		}
		if (*vci == ATM_VCI_ANY) {
			c++;
			if (c >= 1 << vcc->dev->ci_range.vci_bits)
				c = ATM_NOT_RSV_VCI;
		}
		if ((c == ATM_NOT_RSV_VCI || *vci != ATM_VCI_ANY) &&
		    *vpi == ATM_VPI_ANY) {
			p++;
			if (p >= 1 << vcc->dev->ci_range.vpi_bits)
				p = 0;
		}
	} while (old_p != p || old_c != c);
	return -EADDRINUSE;
}

static int __vcc_connect(struct atm_vcc *vcc, struct atm_dev *dev, short vpi,
			 int vci)
{
	struct sock *sk = sk_atm(vcc);
	int error;

	if ((vpi != ATM_VPI_UNSPEC && vpi != ATM_VPI_ANY &&
	    vpi >> dev->ci_range.vpi_bits) || (vci != ATM_VCI_UNSPEC &&
	    vci != ATM_VCI_ANY && vci >> dev->ci_range.vci_bits))
		return -EINVAL;
	if (vci > 0 && vci < ATM_NOT_RSV_VCI && !capable(CAP_NET_BIND_SERVICE))
		return -EPERM;
	error = -ENODEV;
	if (!try_module_get(dev->ops->owner))
		return error;
	vcc->dev = dev;
	write_lock_irq(&vcc_sklist_lock);
	if (test_bit(ATM_DF_REMOVED, &dev->flags) ||
	    (error = find_ci(vcc, &vpi, &vci))) {
		write_unlock_irq(&vcc_sklist_lock);
		goto fail_module_put;
	}
	vcc->vpi = vpi;
	vcc->vci = vci;
	__vcc_insert_socket(sk);
	write_unlock_irq(&vcc_sklist_lock);
	switch (vcc->qos.aal) {
	case ATM_AAL0:
		error = atm_init_aal0(vcc);
		vcc->stats = &dev->stats.aal0;
		break;
	case ATM_NO_AAL:
		/* ATM_AAL5 is also used in the "0 for default" case */
		vcc->qos.aal = ATM_AAL5;
		fallthrough;
	case ATM_AAL5:
		error = atm_init_aal5(vcc);
		vcc->stats = &dev->stats.aal5;
		break;
	default:
		error = -EPROTOTYPE;
	}
	if (!error)
		error = adjust_tp(&vcc->qos.txtp, vcc->qos.aal);
	if (!error)
		error = adjust_tp(&vcc->qos.rxtp, vcc->qos.aal);
	if (error)
		goto fail;
	pr_debug("VCC %d.%d, AAL %d\n", vpi, vci, vcc->qos.aal);
	pr_debug("  TX: %d, PCR %d..%d, SDU %d\n",
		 vcc->qos.txtp.traffic_class,
		 vcc->qos.txtp.min_pcr,
		 vcc->qos.txtp.max_pcr,
		 vcc->qos.txtp.max_sdu);
	pr_debug("  RX: %d, PCR %d..%d, SDU %d\n",
		 vcc->qos.rxtp.traffic_class,
		 vcc->qos.rxtp.min_pcr,
		 vcc->qos.rxtp.max_pcr,
		 vcc->qos.rxtp.max_sdu);

	if (dev->ops->open) {
		error = dev->ops->open(vcc);
		if (error)
			goto fail;
	}
	return 0;

fail:
	vcc_remove_socket(sk);
fail_module_put:
	module_put(dev->ops->owner);
	/* ensure we get dev module ref count correct */
	vcc->dev = NULL;
	return error;
}

int vcc_connect(struct socket *sock, int itf, short vpi, int vci)
{
	struct atm_dev *dev;
	struct atm_vcc *vcc = ATM_SD(sock);
	int error;

	pr_debug("(vpi %d, vci %d)\n", vpi, vci);
	if (sock->state == SS_CONNECTED)
		return -EISCONN;
	if (sock->state != SS_UNCONNECTED)
		return -EINVAL;
	if (!(vpi || vci))
		return -EINVAL;

	if (vpi != ATM_VPI_UNSPEC && vci != ATM_VCI_UNSPEC)
		clear_bit(ATM_VF_PARTIAL, &vcc->flags);
	else
		if (test_bit(ATM_VF_PARTIAL, &vcc->flags))
			return -EINVAL;
	pr_debug("(TX: cl %d,bw %d-%d,sdu %d; "
		 "RX: cl %d,bw %d-%d,sdu %d,AAL %s%d)\n",
		 vcc->qos.txtp.traffic_class, vcc->qos.txtp.min_pcr,
		 vcc->qos.txtp.max_pcr, vcc->qos.txtp.max_sdu,
		 vcc->qos.rxtp.traffic_class, vcc->qos.rxtp.min_pcr,
		 vcc->qos.rxtp.max_pcr, vcc->qos.rxtp.max_sdu,
		 vcc->qos.aal == ATM_AAL5 ? "" :
		 vcc->qos.aal == ATM_AAL0 ? "" : " ??? code ",
		 vcc->qos.aal == ATM_AAL0 ? 0 : vcc->qos.aal);
	if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
		return -EBADFD;
	if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
	    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS)
		return -EINVAL;
	if (likely(itf != ATM_ITF_ANY)) {
		dev = try_then_request_module(atm_dev_lookup(itf),
					      "atm-device-%d", itf);
	} else {
		dev = NULL;
		mutex_lock(&atm_dev_mutex);
		if (!list_empty(&atm_devs)) {
			dev = list_entry(atm_devs.next,
					 struct atm_dev, dev_list);
			atm_dev_hold(dev);
		}
		mutex_unlock(&atm_dev_mutex);
	}
	if (!dev)
		return -ENODEV;
	error = __vcc_connect(vcc, dev, vpi, vci);
	if (error) {
		atm_dev_put(dev);
		return error;
	}
	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC)
		set_bit(ATM_VF_PARTIAL, &vcc->flags);
	if (test_bit(ATM_VF_READY, &ATM_SD(sock)->flags))
		sock->state = SS_CONNECTED;
	return 0;
}

int vcc_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
		int flags)
{
	struct sock *sk = sock->sk;
	struct atm_vcc *vcc;
	struct sk_buff *skb;
	int copied, error = -EINVAL;

	if (sock->state != SS_CONNECTED)
		return -ENOTCONN;

	/* only handle MSG_DONTWAIT and MSG_PEEK */
	if (flags & ~(MSG_DONTWAIT | MSG_PEEK))
		return -EOPNOTSUPP;

	vcc = ATM_SD(sock);
	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
	    !test_bit(ATM_VF_READY, &vcc->flags))
		return 0;

	skb = skb_recv_datagram(sk, flags, &error);
	if (!skb)
		return error;

	copied = skb->len;
	if (copied > size) {
		copied = size;
		msg->msg_flags |= MSG_TRUNC;
	}

	error = skb_copy_datagram_msg(skb, 0, msg, copied);
	if (error)
		return error;
	sock_recv_cmsgs(msg, sk, skb);

	if (!(flags & MSG_PEEK)) {
		pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc),
			 skb->truesize);
		atm_return(vcc, skb->truesize);
	}

	skb_free_datagram(sk, skb);
	return copied;
}

int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
{
	struct sock *sk = sock->sk;
	DEFINE_WAIT(wait);
	struct atm_vcc *vcc;
	struct sk_buff *skb;
	int eff, error;

	lock_sock(sk);
	if (sock->state != SS_CONNECTED) {
		error = -ENOTCONN;
		goto out;
	}
	if (m->msg_name) {
		error = -EISCONN;
		goto out;
	}
	vcc = ATM_SD(sock);
	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
	    !test_bit(ATM_VF_READY, &vcc->flags)) {
		error = -EPIPE;
		send_sig(SIGPIPE, current, 0);
		goto out;
	}
	if (!size) {
		error = 0;
		goto out;
	}
	if (size > vcc->qos.txtp.max_sdu) {
		error = -EMSGSIZE;
		goto out;
	}

	eff = (size+3) & ~3; /* align to word boundary */
	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
	error = 0;
	while (!vcc_tx_ready(vcc, eff)) {
		if (m->msg_flags & MSG_DONTWAIT) {
			error = -EAGAIN;
			break;
		}
		schedule();
		if (signal_pending(current)) {
			error = -ERESTARTSYS;
			break;
		}
		if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
		    !test_bit(ATM_VF_READY, &vcc->flags)) {
			error = -EPIPE;
			send_sig(SIGPIPE, current, 0);
			break;
		}
		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
	}
	finish_wait(sk_sleep(sk), &wait);
	if (error)
		goto out;

	skb = alloc_skb(eff, GFP_KERNEL);
	if (!skb) {
		error = -ENOMEM;
		goto out;
	}
	pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
	atm_account_tx(vcc, skb);

	skb->dev = NULL; /* for paths shared with net_device interfaces */
	if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
		error = -EFAULT;
		goto free_skb;
	}
	if (eff != size)
		memset(skb->data + size, 0, eff-size);

	error = vcc->dev->ops->send(vcc, skb);
	error = error ? error : size;
out:
	release_sock(sk);
	return error;
free_skb:
	atm_return_tx(vcc, skb);
	kfree_skb(skb);
	goto out;
}

__poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	struct atm_vcc *vcc;
	__poll_t mask;

	sock_poll_wait(file, sock, wait);
	mask = 0;

	vcc = ATM_SD(sock);

	/* exceptional events */
	if (sk->sk_err)
		mask = EPOLLERR;

	if (test_bit(ATM_VF_CLOSE, &vcc->flags))
		mask |= EPOLLHUP;

	/* readable? */
	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
		mask |= EPOLLIN | EPOLLRDNORM;

	/* writable? */
	if (vcc->qos.txtp.traffic_class != ATM_NONE &&
	    vcc_writable(sk))
		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;

	return mask;
}

static int check_tp(const struct atm_trafprm *tp)
{
	/* @@@ Should be merged with adjust_tp */
	if (tp->traffic_class > ATM_ANYCLASS)
		return -EINVAL;
	if (!tp->traffic_class || tp->traffic_class == ATM_ANYCLASS)
		return 0;
	if (tp->traffic_class != ATM_UBR && !tp->min_pcr && !tp->pcr &&
	    !tp->max_pcr)
		return -EINVAL;
	if (tp->min_pcr == ATM_MAX_PCR)
		return -EINVAL;
	if (tp->min_pcr && tp->max_pcr && tp->max_pcr != ATM_MAX_PCR &&
	    tp->min_pcr > tp->max_pcr)
		return -EINVAL;
	/*
	 * We allow pcr to be outside [min_pcr,max_pcr], because later
	 * adjustment may still push it in the valid range.
	 */
	return 0;
}

static int check_qos(const struct atm_qos *qos)
{
	int error;

	if (!qos->txtp.traffic_class && !qos->rxtp.traffic_class)
		return -EINVAL;
	if (qos->txtp.traffic_class != qos->rxtp.traffic_class &&
	    qos->txtp.traffic_class && qos->rxtp.traffic_class &&
	    qos->txtp.traffic_class != ATM_ANYCLASS &&
	    qos->rxtp.traffic_class != ATM_ANYCLASS)
		return -EINVAL;
	error = check_tp(&qos->txtp);
	if (error)
		return error;
	return check_tp(&qos->rxtp);
}

int vcc_setsockopt(struct socket *sock, int level, int optname,
		   sockptr_t optval, unsigned int optlen)
{
	struct atm_vcc *vcc;
	int value;
	int error;

	if (__SO_LEVEL_MATCH(optname, level) && optlen != __SO_SIZE(optname))
		return -EINVAL;

	vcc = ATM_SD(sock);
	switch (optname) {
	case SO_ATMQOS:
	{
		struct atm_qos qos;

		error = copy_safe_from_sockptr(&qos, sizeof(qos), optval,
					       optlen);
		if (error)
			return error;
		error = check_qos(&qos);
		if (error)
			return error;
		/* QoS cannot be renegotiated on an already connected VCC. */
		if (sock->state == SS_CONNECTED)
			return -EOPNOTSUPP;
		if (sock->state != SS_UNCONNECTED)
			return -EBADFD;
		vcc->qos = qos;
		set_bit(ATM_VF_HASQOS, &vcc->flags);
		return 0;
	}
	case SO_SETCLP:
		error = copy_safe_from_sockptr(&value, sizeof(value), optval,
					       optlen);
		if (error)
			return error;
		if (value)
			vcc->atm_options |= ATM_ATMOPT_CLP;
		else
			vcc->atm_options &= ~ATM_ATMOPT_CLP;
		return 0;
	default:
		return -EINVAL;
	}
}

int vcc_getsockopt(struct socket *sock, int level, int optname,
		   sockopt_t *opt)
{
	struct atm_vcc *vcc;
	int val;
	int len;

	len = opt->optlen;
	if (__SO_LEVEL_MATCH(optname, level) && len != __SO_SIZE(optname))
		return -EINVAL;

	vcc = ATM_SD(sock);
	switch (optname) {
	case SO_ATMQOS:
		if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
			return -EINVAL;
		return copy_to_iter(&vcc->qos, sizeof(vcc->qos),
				    &opt->iter_out) != sizeof(vcc->qos)
			? -EFAULT : 0;
	case SO_SETCLP:
		val = vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0;
		return copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
		       sizeof(val) ? -EFAULT : 0;
	case SO_ATMPVC:
	{
		struct sockaddr_atmpvc pvc;

		if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
			return -ENOTCONN;
		memset(&pvc, 0, sizeof(pvc));
		pvc.sap_family = AF_ATMPVC;
		pvc.sap_addr.itf = vcc->dev->number;
		pvc.sap_addr.vpi = vcc->vpi;
		pvc.sap_addr.vci = vcc->vci;
		return copy_to_iter(&pvc, sizeof(pvc), &opt->iter_out) !=
		       sizeof(pvc) ? -EFAULT : 0;
	}
	default:
		return -EINVAL;
	}
}

int register_atmdevice_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_register(&atm_dev_notify_chain, nb);
}
EXPORT_SYMBOL_GPL(register_atmdevice_notifier);

void unregister_atmdevice_notifier(struct notifier_block *nb)
{
	atomic_notifier_chain_unregister(&atm_dev_notify_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_atmdevice_notifier);

static int __init atm_init(void)
{
	int error;

	error = proto_register(&vcc_proto, 0);
	if (error < 0)
		goto out;
	error = atmpvc_init();
	if (error < 0) {
		pr_err("atmpvc_init() failed with %d\n", error);
		goto out_unregister_vcc_proto;
	}
	error = atm_proc_init();
	if (error < 0) {
		pr_err("atm_proc_init() failed with %d\n", error);
		goto out_atmpvc_exit;
	}
	error = atm_sysfs_init();
	if (error < 0) {
		pr_err("atm_sysfs_init() failed with %d\n", error);
		goto out_atmproc_exit;
	}
out:
	return error;
out_atmproc_exit:
	atm_proc_exit();
out_atmpvc_exit:
	atmpvc_exit();
out_unregister_vcc_proto:
	proto_unregister(&vcc_proto);
	goto out;
}

static void __exit atm_exit(void)
{
	atm_proc_exit();
	atm_sysfs_exit();
	atmpvc_exit();
	proto_unregister(&vcc_proto);
}

subsys_initcall(atm_init);

module_exit(atm_exit);

MODULE_DESCRIPTION("Asynchronous Transfer Mode (ATM) networking core");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_ATMPVC);