/* 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.h>
  #include <linux/time.h>		/* struct timeval */
  #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/atomic.h>

  
  #include "resources.h"		/* atm_find_dev */
  #include "common.h"		/* prototypes */
  #include "protocols.h"		/* atm_init_<transport> */
  #include "addr.h"		/* address registry */
  #include "signaling.h"		/* for WAITING and sigd_attach */

  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 struct sk_buff *alloc_tx(struct atm_vcc *vcc, unsigned int size)

  {
  	struct sk_buff *skb;
  	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
  ",

  			 sk_wmem_alloc_get(sk), size, sk->sk_sndbuf);

  		return NULL;
  	}

  	while (!(skb = alloc_skb(size, GFP_KERNEL)))
  		schedule();

  	pr_debug("%d += %d
  ", sk_wmem_alloc_get(sk), skb->truesize);

  	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
  	return skb;
  }

  static void vcc_sock_destruct(struct sock *sk)
  {
  	if (atomic_read(&sk->sk_rmem_alloc))

  		printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.
  ",
  		       __func__, atomic_read(&sk->sk_rmem_alloc));

  
  	if (atomic_read(&sk->sk_wmem_alloc))

  		printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.
  ",
  		       __func__, atomic_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 (wq_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 +

  		atomic_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 (wq_has_sleeper(wq))
  			wake_up_interruptible(&wq->wait);

  		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);

  	}

  	rcu_read_unlock();

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

  int vcc_create(struct net *net, struct socket *sock, int protocol, int family)

  {
  	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);

  	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;

  	memset(&vcc->local, 0, sizeof(struct sockaddr_atmsvc));
  	memset(&vcc->remote, 0, sizeof(struct sockaddr_atmsvc));

  	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */

  	atomic_set(&sk->sk_wmem_alloc, 1);

  	atomic_set(&sk->sk_rmem_alloc, 0);
  	vcc->push = NULL;
  	vcc->pop = NULL;
  	vcc->push_oam = 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) {
  		if (vcc->dev->ops->close)
  			vcc->dev->ops->close(vcc);
  		if (vcc->push)
  			vcc->push(vcc, NULL); /* atmarpd has no push */

  		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {

  			atm_return(vcc, skb->truesize);

  			kfree_skb(skb);
  		}
  
  		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;
  	clear_bit(ATM_VF_WAITING, &vcc->flags);
  	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
  ",
  		__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 *node, *tmp;
  		struct sock *s;
  		struct atm_vcc *vcc;
  
  		sk_for_each_safe(s, node, 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;
  	case ATM_AAL34:
  		max_sdu = ATM_MAX_AAL34_PDU;
  		break;
  	default:
  		pr_warning("AAL problems ... (%d)
  ", aal);
  		/* fall through */
  	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 hlist_node *node;
  	struct sock *s;
  	struct atm_vcc *walk;
  
  	sk_for_each(s, node, 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_AAL34:
  		error = atm_init_aal34(vcc);
  		vcc->stats = &dev->stats.aal34;
  		break;
  	case ATM_NO_AAL:
  		/* ATM_AAL5 is also used in the "0 for default" case */
  		vcc->qos.aal = ATM_AAL5;
  		/* fall through */
  	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
  ", vpi, vci, vcc->qos.aal);
  	pr_debug("  TX: %d, PCR %d..%d, SDU %d
  ",
  		 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
  ",
  		 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)
  ", 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)
  ",
  		 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 kiocb *iocb, 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_RELEASED, &vcc->flags) ||
  	    test_bit(ATM_VF_CLOSE, &vcc->flags) ||

  	    !test_bit(ATM_VF_READY, &vcc->flags))
  		return 0;
  
  	skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &error);
  	if (!skb)
  		return error;

  	copied = skb->len;

  	if (copied > size) {

  		copied = size;

  		msg->msg_flags |= MSG_TRUNC;
  	}

  	error = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
  	if (error)
  		return error;

  	sock_recv_ts_and_drops(msg, sk, skb);

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

  	skb_free_datagram(sk, skb);
  	return copied;

  }

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

  	int eff, error;

  	const void __user *buff;
  	int size;
  
  	lock_sock(sk);
  	if (sock->state != SS_CONNECTED) {
  		error = -ENOTCONN;
  		goto out;
  	}
  	if (m->msg_name) {
  		error = -EISCONN;
  		goto out;
  	}
  	if (m->msg_iovlen != 1) {
  		error = -ENOSYS; /* fix this later @@@ */
  		goto out;
  	}
  	buff = m->msg_iov->iov_base;
  	size = m->msg_iov->iov_len;
  	vcc = ATM_SD(sock);
  	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
  	    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 < 0 || 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 (!(skb = alloc_tx(vcc, eff))) {

  		if (m->msg_flags & MSG_DONTWAIT) {
  			error = -EAGAIN;
  			break;
  		}
  		schedule();
  		if (signal_pending(current)) {
  			error = -ERESTARTSYS;
  			break;
  		}

  		if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
  		    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->dev = NULL; /* for paths shared with net_device interfaces */
  	ATM_SKB(skb)->atm_options = vcc->atm_options;

  	if (copy_from_user(skb_put(skb, size), buff, size)) {

  		kfree_skb(skb);
  		error = -EFAULT;
  		goto out;
  	}

  	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;
  }

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

  	sock_poll_wait(file, sk_sleep(sk), wait);

  	mask = 0;
  
  	vcc = ATM_SD(sock);
  
  	/* exceptional events */
  	if (sk->sk_err)
  		mask = POLLERR;
  
  	if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
  	    test_bit(ATM_VF_CLOSE, &vcc->flags))
  		mask |= POLLHUP;
  
  	/* readable? */
  	if (!skb_queue_empty(&sk->sk_receive_queue))
  		mask |= POLLIN | POLLRDNORM;
  
  	/* writable? */
  	if (sock->state == SS_CONNECTING &&
  	    test_bit(ATM_VF_WAITING, &vcc->flags))
  		return mask;
  
  	if (vcc->qos.txtp.traffic_class != ATM_NONE &&
  	    vcc_writable(sk))
  		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
  
  	return mask;
  }

  static int atm_change_qos(struct atm_vcc *vcc, struct atm_qos *qos)

  {
  	int error;
  
  	/*
  	 * Don't let the QoS change the already connected AAL type nor the
  	 * traffic class.
  	 */
  	if (qos->aal != vcc->qos.aal ||
  	    qos->rxtp.traffic_class != vcc->qos.rxtp.traffic_class ||
  	    qos->txtp.traffic_class != vcc->qos.txtp.traffic_class)
  		return -EINVAL;

  	error = adjust_tp(&qos->txtp, qos->aal);
  	if (!error)
  		error = adjust_tp(&qos->rxtp, qos->aal);
  	if (error)
  		return error;
  	if (!vcc->dev->ops->change_qos)
  		return -EOPNOTSUPP;

  	if (sk_atm(vcc)->sk_family == AF_ATMPVC)

  		return vcc->dev->ops->change_qos(vcc, qos, ATM_MF_SET);
  	return svc_change_qos(vcc, qos);

  }

  static int check_tp(const struct atm_trafprm *tp)

  {
  	/* @@@ Should be merged with adjust_tp */

  	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,

  		   char __user *optval, unsigned int optlen)

  {
  	struct atm_vcc *vcc;
  	unsigned long 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;
  
  		if (copy_from_user(&qos, optval, sizeof(qos)))
  			return -EFAULT;
  		error = check_qos(&qos);
  		if (error)
  			return error;
  		if (sock->state == SS_CONNECTED)
  			return atm_change_qos(vcc, &qos);
  		if (sock->state != SS_UNCONNECTED)
  			return -EBADFD;
  		vcc->qos = qos;
  		set_bit(ATM_VF_HASQOS, &vcc->flags);
  		return 0;

  	}

  	case SO_SETCLP:
  		if (get_user(value, (unsigned long __user *)optval))
  			return -EFAULT;
  		if (value)
  			vcc->atm_options |= ATM_ATMOPT_CLP;
  		else
  			vcc->atm_options &= ~ATM_ATMOPT_CLP;
  		return 0;
  	default:
  		if (level == SOL_SOCKET)
  			return -EINVAL;
  		break;
  	}
  	if (!vcc->dev || !vcc->dev->ops->setsockopt)
  		return -EINVAL;
  	return vcc->dev->ops->setsockopt(vcc, level, optname, optval, optlen);

  }

  int vcc_getsockopt(struct socket *sock, int level, int optname,
  		   char __user *optval, int __user *optlen)
  {
  	struct atm_vcc *vcc;
  	int len;
  
  	if (get_user(len, optlen))
  		return -EFAULT;
  	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_user(optval, &vcc->qos, sizeof(vcc->qos))
  			? -EFAULT : 0;
  	case SO_SETCLP:
  		return put_user(vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0,
  				(unsigned long __user *)optval) ? -EFAULT : 0;
  	case SO_ATMPVC:
  	{
  		struct sockaddr_atmpvc pvc;
  
  		if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
  			return -ENOTCONN;
  		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_user(optval, &pvc, sizeof(pvc)) ? -EFAULT : 0;
  	}
  	default:
  		if (level == SOL_SOCKET)
  			return -EINVAL;

  		break;

  	}

  	if (!vcc->dev || !vcc->dev->ops->getsockopt)
  		return -EINVAL;

  	return vcc->dev->ops->getsockopt(vcc, level, optname, optval, len);
  }

  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
  ", error);

  		goto out_unregister_vcc_proto;
  	}

  	error = atmsvc_init();
  	if (error < 0) {

  		pr_err("atmsvc_init() failed with %d
  ", error);

  		goto out_atmpvc_exit;
  	}

  	error = atm_proc_init();
  	if (error < 0) {

  		pr_err("atm_proc_init() failed with %d
  ", error);

  		goto out_atmsvc_exit;
  	}

  	error = atm_sysfs_init();
  	if (error < 0) {

  		pr_err("atm_sysfs_init() failed with %d
  ", error);

  		goto out_atmproc_exit;
  	}

  out:
  	return error;

  out_atmproc_exit:
  	atm_proc_exit();

  out_atmsvc_exit:
  	atmsvc_exit();
  out_atmpvc_exit:
  	atmsvc_exit();
  out_unregister_vcc_proto:
  	proto_unregister(&vcc_proto);
  	goto out;
  }
  
  static void __exit atm_exit(void)
  {
  	atm_proc_exit();

  	atm_sysfs_exit();

  	atmsvc_exit();
  	atmpvc_exit();
  	proto_unregister(&vcc_proto);
  }

  subsys_initcall(atm_init);

  module_exit(atm_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_NETPROTO(PF_ATMPVC);
  MODULE_ALIAS_NETPROTO(PF_ATMSVC);