1 files changed, 230 insertions, 90 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index f572b31a2..a30ee427e 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -46,6 +46,7 @@
 #include <linux/device.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/file.h>
 #include <asm/unaligned.h>
 #include <net/slhc_vj.h>
 #include <linux/atomic.h>
@@ -183,6 +184,12 @@ struct channel {
 #endif /* CONFIG_PPP_MULTILINK */
 };
 
+struct ppp_config {
+	struct file *file;
+	s32 unit;
+	bool ifname_is_set;
+};
+
 /*
  * SMP locking issues:
  * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels
@@ -269,8 +276,7 @@ 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);
@@ -282,6 +288,7 @@ static int unit_get(struct idr *p, void *ptr);
 static int unit_set(struct idr *p, void *ptr, int n);
 static void unit_put(struct idr *p, int n);
 static void *unit_find(struct idr *p, int n);
+static void ppp_setup(struct net_device *dev);
 
 static const struct net_device_ops ppp_netdev_ops;
 
@@ -853,12 +860,12 @@ 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 +967,188 @@ static struct pernet_operations ppp_net_ops = {
 	.size = sizeof(struct ppp_net),
 };
 
+static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)
+{
+	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;
+
+	if (!ifname_is_set)
+		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, conf->ifname_is_set);
+	if (err < 0)
+		return err;
+
+	conf->file->private_data = &ppp->file;
+
+	return 0;
+}
+
+static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
+	[IFLA_PPP_DEV_FD]	= { .type = NLA_S32 },
+};
+
+static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	if (!data)
+		return -EINVAL;
+
+	if (!data[IFLA_PPP_DEV_FD])
+		return -EINVAL;
+	if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0)
+		return -EBADF;
+
+	return 0;
+}
+
+static int ppp_nl_newlink(struct net *src_net, struct net_device *dev,
+			  struct nlattr *tb[], struct nlattr *data[])
+{
+	struct ppp_config conf = {
+		.unit = -1,
+		.ifname_is_set = true,
+	};
+	struct file *file;
+	int err;
+
+	file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD]));
+	if (!file)
+		return -EBADF;
+
+	/* rtnl_lock is already held here, but ppp_create_interface() locks
+	 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids
+	 * possible deadlock due to lock order inversion, at the cost of
+	 * pushing the problem back to userspace.
+	 */
+	if (!mutex_trylock(&ppp_mutex)) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	if (file->f_op != &ppp_device_fops || file->private_data) {
+		err = -EBADF;
+		goto out_unlock;
+	}
+
+	conf.file = file;
+	err = ppp_dev_configure(src_net, dev, &conf);
+
+out_unlock:
+	mutex_unlock(&ppp_mutex);
+out:
+	fput(file);
+
+	return err;
+}
+
+static void ppp_nl_dellink(struct net_device *dev, struct list_head *head)
+{
+	unregister_netdevice_queue(dev, head);
+}
+
+static size_t ppp_nl_get_size(const struct net_device *dev)
+{
+	return 0;
+}
+
+static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	return 0;
+}
+
+static struct net *ppp_nl_get_link_net(const struct net_device *dev)
+{
+	struct ppp *ppp = netdev_priv(dev);
+
+	return ppp->ppp_net;
+}
+
+static struct rtnl_link_ops ppp_link_ops __read_mostly = {
+	.kind		= "ppp",
+	.maxtype	= IFLA_PPP_MAX,
+	.policy		= ppp_nl_policy,
+	.priv_size	= sizeof(struct ppp),
+	.setup		= ppp_setup,
+	.validate	= ppp_nl_validate,
+	.newlink	= ppp_nl_newlink,
+	.dellink	= ppp_nl_dellink,
+	.get_size	= ppp_nl_get_size,
+	.fill_info	= ppp_nl_fill_info,
+	.get_link_net	= ppp_nl_get_link_net,
+};
+
 #define PPP_MAJOR	108
 
 /* Called at boot time if ppp is compiled into the kernel,
@@ -988,11 +1177,19 @@ static int __init ppp_init(void)
 		goto out_chrdev;
 	}
 
+	err = rtnl_link_register(&ppp_link_ops);
+	if (err) {
+		pr_err("failed to register rtnetlink PPP handler\n");
+		goto out_class;
+	}
+
 	/* not a big deal if we fail here :-) */
 	device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
 
 	return 0;
 
+out_class:
+	class_destroy(ppp_class);
 out_chrdev:
 	unregister_chrdev(PPP_MAJOR, "ppp");
 out_net:
@@ -2404,8 +2601,6 @@ ppp_unregister_channel(struct ppp_channel *chan)
 	spin_lock_bh(&pn->all_channels_lock);
 	list_del(&pch->list);
 	spin_unlock_bh(&pn->all_channels_lock);
-	put_net(pch->chan_net);
-	pch->chan_net = NULL;
 
 	pch->file.dead = 1;
 	wake_up_interruptible(&pch->file.rwait);
@@ -2732,102 +2927,42 @@ 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,
+		.ifname_is_set = false,
+	};
+	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);
+	dev->rtnl_link_ops = &ppp_link_ops;
 
 	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;
 }
 
 /*
@@ -2999,6 +3134,9 @@ ppp_disconnect_channel(struct channel *pch)
  */
 static void ppp_destroy_channel(struct channel *pch)
 {
+	put_net(pch->chan_net);
+	pch->chan_net = NULL;
+
 	atomic_dec(&channel_count);
 
 	if (!pch->file.dead) {
@@ -3016,6 +3154,7 @@ static void __exit ppp_cleanup(void)
 	/* should never happen */
 	if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
 		pr_err("PPP: removing module but units remain!\n");
+	rtnl_link_unregister(&ppp_link_ops);
 	unregister_chrdev(PPP_MAJOR, "ppp");
 	device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
 	class_destroy(ppp_class);
@@ -3074,4 +3213,5 @@ EXPORT_SYMBOL(ppp_register_compressor);
 EXPORT_SYMBOL(ppp_unregister_compressor);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0);
+MODULE_ALIAS_RTNL_LINK("ppp");
 MODULE_ALIAS("devname:ppp");