Commit 7d9f0b48 authored by Guillaume Nault's avatar Guillaume Nault Committed by David S. Miller
Browse files

ppp: define reusable device creation functions 



Move PPP device initialisation and registration out of
ppp_create_interface().
This prepares code for device registration with rtnetlink.

While there, simplify the prototype of ppp_create_interface():

  * Since ppp_dev_configure() takes care of setting file->private_data,
    there's no need to return a ppp structure to ppp_unattached_ioctl()
    anymore.

  * The unit parameter is made read/write so that ppp_create_interface()
    can tell which unit number has been assigned.

Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ac1f74a7

drivers/net/ppp/ppp_generic.c

+118 −88
Original line number Diff line number Diff line
@@ -183,6 +183,11 @@ struct channel { 
#endif /* CONFIG_PPP_MULTILINK */

};



struct ppp_config {

	struct file *file;

	s32 unit;

};



/*

 * SMP locking issues:

 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
@@ -269,8 +274,7 @@ static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 
static void ppp_ccp_closed(struct ppp *ppp);

static struct compressor *find_compressor(int type);

static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st);

static struct ppp *ppp_create_interface(struct net *net, int unit,

					struct file *file, int *retp);

static int ppp_create_interface(struct net *net, struct file *file, int *unit);

static void init_ppp_file(struct ppp_file *pf, int kind);

static void ppp_destroy_interface(struct ppp *ppp);

static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit);
@@ -853,12 +857,12 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 
		/* Create a new ppp unit */

		if (get_user(unit, p))

			break;

		ppp = ppp_create_interface(net, unit, file, &err);

		if (!ppp)

		err = ppp_create_interface(net, file, &unit);

		if (err < 0)

			break;

		file->private_data = &ppp->file;



		err = -EFAULT;

		if (put_user(ppp->file.index, p))

		if (put_user(unit, p))

			break;

		err = 0;

		break;
@@ -960,6 +964,94 @@ static struct pernet_operations ppp_net_ops = { 
	.size = sizeof(struct ppp_net),

};



static int ppp_unit_register(struct ppp *ppp, int unit)

{

	struct ppp_net *pn = ppp_pernet(ppp->ppp_net);

	int ret;



	mutex_lock(&pn->all_ppp_mutex);



	if (unit < 0) {

		ret = unit_get(&pn->units_idr, ppp);

		if (ret < 0)

			goto err;

	} else {

		/* Caller asked for a specific unit number. Fail with -EEXIST

		 * if unavailable. For backward compatibility, return -EEXIST

		 * too if idr allocation fails; this makes pppd retry without

		 * requesting a specific unit number.

		 */

		if (unit_find(&pn->units_idr, unit)) {

			ret = -EEXIST;

			goto err;

		}

		ret = unit_set(&pn->units_idr, ppp, unit);

		if (ret < 0) {

			/* Rewrite error for backward compatibility */

			ret = -EEXIST;

			goto err;

		}

	}

	ppp->file.index = ret;



	snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index);



	ret = register_netdevice(ppp->dev);

	if (ret < 0)

		goto err_unit;



	atomic_inc(&ppp_unit_count);



	mutex_unlock(&pn->all_ppp_mutex);



	return 0;



err_unit:

	unit_put(&pn->units_idr, ppp->file.index);

err:

	mutex_unlock(&pn->all_ppp_mutex);



	return ret;

}



static int ppp_dev_configure(struct net *src_net, struct net_device *dev,

			     const struct ppp_config *conf)

{

	struct ppp *ppp = netdev_priv(dev);

	int indx;

	int err;



	ppp->dev = dev;

	ppp->ppp_net = src_net;

	ppp->mru = PPP_MRU;

	ppp->owner = conf->file;



	init_ppp_file(&ppp->file, INTERFACE);

	ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */



	for (indx = 0; indx < NUM_NP; ++indx)

		ppp->npmode[indx] = NPMODE_PASS;

	INIT_LIST_HEAD(&ppp->channels);

	spin_lock_init(&ppp->rlock);

	spin_lock_init(&ppp->wlock);

#ifdef CONFIG_PPP_MULTILINK

	ppp->minseq = -1;

	skb_queue_head_init(&ppp->mrq);

#endif /* CONFIG_PPP_MULTILINK */

#ifdef CONFIG_PPP_FILTER

	ppp->pass_filter = NULL;

	ppp->active_filter = NULL;

#endif /* CONFIG_PPP_FILTER */



	err = ppp_unit_register(ppp, conf->unit);

	if (err < 0)

		return err;



	conf->file->private_data = &ppp->file;



	return 0;

}



#define PPP_MAJOR	108



/* Called at boot time if ppp is compiled into the kernel,
@@ -2732,102 +2824,40 @@ ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 
 * or if there is already a unit with the requested number.

 * unit == -1 means allocate a new number.

 */

static struct ppp *ppp_create_interface(struct net *net, int unit,

					struct file *file, int *retp)

static int ppp_create_interface(struct net *net, struct file *file, int *unit)

{

	struct ppp_config conf = {

		.file = file,

		.unit = *unit,

	};

	struct net_device *dev;

	struct ppp *ppp;

	struct ppp_net *pn;

	struct net_device *dev = NULL;

	int ret = -ENOMEM;

	int i;

	int err;



	dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup);

	if (!dev)

		goto out1;



	pn = ppp_pernet(net);



	ppp = netdev_priv(dev);

	ppp->dev = dev;

	ppp->mru = PPP_MRU;

	init_ppp_file(&ppp->file, INTERFACE);

	ppp->file.hdrlen = PPP_HDRLEN - 2;	/* don't count proto bytes */

	ppp->owner = file;

	for (i = 0; i < NUM_NP; ++i)

		ppp->npmode[i] = NPMODE_PASS;

	INIT_LIST_HEAD(&ppp->channels);

	spin_lock_init(&ppp->rlock);

	spin_lock_init(&ppp->wlock);

#ifdef CONFIG_PPP_MULTILINK

	ppp->minseq = -1;

	skb_queue_head_init(&ppp->mrq);

#endif /* CONFIG_PPP_MULTILINK */

#ifdef CONFIG_PPP_FILTER

	ppp->pass_filter = NULL;

	ppp->active_filter = NULL;

#endif /* CONFIG_PPP_FILTER */



	/*

	 * drum roll: don't forget to set

	 * the net device is belong to

	 */

	if (!dev) {

		err = -ENOMEM;

		goto err;

	}

	dev_net_set(dev, net);



	rtnl_lock();

	mutex_lock(&pn->all_ppp_mutex);



	if (unit < 0) {

		unit = unit_get(&pn->units_idr, ppp);

		if (unit < 0) {

			ret = unit;

			goto out2;

		}

	} else {

		ret = -EEXIST;

		if (unit_find(&pn->units_idr, unit))

			goto out2; /* unit already exists */

		/*

		 * if caller need a specified unit number

		 * lets try to satisfy him, otherwise --

		 * he should better ask us for new unit number

		 *

		 * NOTE: yes I know that returning EEXIST it's not

		 * fair but at least pppd will ask us to allocate

		 * new unit in this case so user is happy :)

		 */

		unit = unit_set(&pn->units_idr, ppp, unit);

		if (unit < 0)

			goto out2;

	}



	/* Initialize the new ppp unit */

	ppp->file.index = unit;

	sprintf(dev->name, "ppp%d", unit);



	ret = register_netdevice(dev);

	if (ret != 0) {

		unit_put(&pn->units_idr, unit);

		netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",

			   dev->name, ret);

		goto out2;

	}



	ppp->ppp_net = net;

	err = ppp_dev_configure(net, dev, &conf);

	if (err < 0)

		goto err_dev;

	ppp = netdev_priv(dev);

	*unit = ppp->file.index;



	atomic_inc(&ppp_unit_count);

	mutex_unlock(&pn->all_ppp_mutex);

	rtnl_unlock();



	*retp = 0;

	return ppp;

	return 0;



out2:

	mutex_unlock(&pn->all_ppp_mutex);

err_dev:

	rtnl_unlock();

	free_netdev(dev);

out1:

	*retp = ret;

	return NULL;

err:

	return err;

}



/*

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