[PATCH RFC 29/31] net: Make AF_PACKET handle multiple network namespaces

["Eric W. Biederman" <ebiederm@xmission.com>]

From: Eric W. Biederman <ebiederm@xmission.com> - unquoted

This is done by making all of the relevant global variables
per network namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 net/packet/af_packet.c |  125 +++++++++++++++++++++++++++++++-----------------
 1 files changed, 81 insertions(+), 44 deletions(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 4ac9f9f..c772491 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -152,8 +152,8 @@ dev->hard_header == NULL (ll header is added by device, we cannot control it)
  */
 
 /* List of all packet sockets. */
-static HLIST_HEAD(packet_sklist);
-static DEFINE_RWLOCK(packet_sklist_lock);
+static DEFINE_PER_NET(rwlock_t, packet_sklist_lock);
+static DEFINE_PER_NET(struct hlist_head, packet_sklist);
 
 static atomic_t packet_socks_nr;
 
@@ -264,9 +264,6 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct packet_type *pt, struct n
 	struct sock *sk;
 	struct sockaddr_pkt *spkt;
 
-	if (!net_eq(dev->nd_net, init_net()))
-		goto out;
-
 	/*
 	 *	When we registered the protocol we saved the socket in the data
 	 *	field for just this event.
@@ -288,6 +285,9 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct packet_type *pt, struct n
 	if (skb->pkt_type == PACKET_LOOPBACK)
 		goto out;
 
+	if (!net_eq(dev->nd_net, sk->sk_net))
+		goto out;
+
 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 		goto oom;
 
@@ -359,7 +359,7 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
 	 */
 
 	saddr->spkt_device[13] = 0;
-	dev = dev_get_by_name(init_net(), saddr->spkt_device);
+	dev = dev_get_by_name(sk->sk_net, saddr->spkt_device);
 	err = -ENODEV;
 	if (dev == NULL)
 		goto out_unlock;
@@ -475,15 +475,15 @@ static int packet_rcv(struct sk_buff *skb, struct packet_type *pt, struct net_de
 	int skb_len = skb->len;
 	unsigned snaplen;
 
-	if (!net_eq(dev->nd_net, init_net()))
-		goto drop;
-
 	if (skb->pkt_type == PACKET_LOOPBACK)
 		goto drop;
 
 	sk = pt->af_packet_priv;
 	po = pkt_sk(sk);
 
+	if (!net_eq(dev->nd_net, sk->sk_net))
+		goto drop;
+
 	skb->dev = dev;
 
 	if (dev->hard_header) {
@@ -583,15 +583,15 @@ static int tpacket_rcv(struct sk_buff *skb, struct packet_type *pt, struct net_d
 	unsigned short macoff, netoff;
 	struct sk_buff *copy_skb = NULL;
 
-	if (!net_eq(dev->nd_net, init_net()))
-		goto drop;
-
 	if (skb->pkt_type == PACKET_LOOPBACK)
 		goto drop;
 
 	sk = pt->af_packet_priv;
 	po = pkt_sk(sk);
 
+	if (!net_eq(dev->nd_net, sk->sk_net))
+		goto drop;
+
 	if (dev->hard_header) {
 		if (sk->sk_type != SOCK_DGRAM)
 			skb_push(skb, skb->data - skb->mac.raw);
@@ -744,7 +744,7 @@ static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
 	}
 
 
-	dev = dev_get_by_index(init_net(), ifindex);
+	dev = dev_get_by_index(sk->sk_net, ifindex);
 	err = -ENXIO;
 	if (dev == NULL)
 		goto out_unlock;
@@ -817,15 +817,17 @@ static int packet_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 	struct packet_sock *po;
+	net_t net;
 
 	if (!sk)
 		return 0;
 
+	net = sk->sk_net;
 	po = pkt_sk(sk);
 
-	write_lock_bh(&packet_sklist_lock);
+	write_lock_bh(&per_net(packet_sklist_lock, net));
 	sk_del_node_init(sk);
-	write_unlock_bh(&packet_sklist_lock);
+	write_unlock_bh(&per_net(packet_sklist_lock, net));
 
 	/*
 	 *	Unhook packet receive handler.
@@ -943,7 +945,7 @@ static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, int add
 		return -EINVAL;
 	strlcpy(name,uaddr->sa_data,sizeof(name));
 
-	dev = dev_get_by_name(init_net(), name);
+	dev = dev_get_by_name(sk->sk_net, name);
 	if (dev) {
 		err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
 		dev_put(dev);
@@ -971,7 +973,7 @@ static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len
 
 	if (sll->sll_ifindex) {
 		err = -ENODEV;
-		dev = dev_get_by_index(init_net(), sll->sll_ifindex);
+		dev = dev_get_by_index(sk->sk_net, sll->sll_ifindex);
 		if (dev == NULL)
 			goto out;
 	}
@@ -1000,9 +1002,6 @@ static int packet_create(net_t net, struct socket *sock, int protocol)
 	__be16 proto = (__force __be16)protocol; /* weird, but documented */
 	int err;
 
-	if (!net_eq(net, init_net()))
-		return -EAFNOSUPPORT;
-
 	if (!capable(CAP_NET_RAW))
 		return -EPERM;
 	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW
@@ -1052,9 +1051,9 @@ static int packet_create(net_t net, struct socket *sock, int protocol)
 		po->running = 1;
 	}
 
-	write_lock_bh(&packet_sklist_lock);
-	sk_add_node(sk, &packet_sklist);
-	write_unlock_bh(&packet_sklist_lock);
+	write_lock_bh(&per_net(packet_sklist_lock, net));
+	sk_add_node(sk, &per_net(packet_sklist, net));
+	write_unlock_bh(&per_net(packet_sklist_lock, net));
 	return(0);
 out:
 	return err;
@@ -1158,7 +1157,7 @@ static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
 		return -EOPNOTSUPP;
 
 	uaddr->sa_family = AF_PACKET;
-	dev = dev_get_by_index(init_net(), pkt_sk(sk)->ifindex);
+	dev = dev_get_by_index(sk->sk_net, pkt_sk(sk)->ifindex);
 	if (dev) {
 		strlcpy(uaddr->sa_data, dev->name, 15);
 		dev_put(dev);
@@ -1184,7 +1183,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
 	sll->sll_family = AF_PACKET;
 	sll->sll_ifindex = po->ifindex;
 	sll->sll_protocol = po->num;
-	dev = dev_get_by_index(init_net(), po->ifindex);
+	dev = dev_get_by_index(sk->sk_net, po->ifindex);
 	if (dev) {
 		sll->sll_hatype = dev->type;
 		sll->sll_halen = dev->addr_len;
@@ -1237,7 +1236,7 @@ static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
 	rtnl_lock();
 
 	err = -ENODEV;
-	dev = __dev_get_by_index(init_net(), mreq->mr_ifindex);
+	dev = __dev_get_by_index(sk->sk_net, mreq->mr_ifindex);
 	if (!dev)
 		goto done;
 
@@ -1291,7 +1290,7 @@ static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
 			if (--ml->count == 0) {
 				struct net_device *dev;
 				*mlp = ml->next;
-				dev = dev_get_by_index(init_net(), ml->ifindex);
+				dev = dev_get_by_index(sk->sk_net, ml->ifindex);
 				if (dev) {
 					packet_dev_mc(dev, ml, -1);
 					dev_put(dev);
@@ -1319,7 +1318,7 @@ static void packet_flush_mclist(struct sock *sk)
 		struct net_device *dev;
 
 		po->mclist = ml->next;
-		if ((dev = dev_get_by_index(init_net(), ml->ifindex)) != NULL) {
+		if ((dev = dev_get_by_index(sk->sk_net, ml->ifindex)) != NULL) {
 			packet_dev_mc(dev, ml, -1);
 			dev_put(dev);
 		}
@@ -1438,12 +1437,10 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
 	struct sock *sk;
 	struct hlist_node *node;
 	struct net_device *dev = (struct net_device*)data;
+	net_t net = dev->nd_net;
 
-	if (!net_eq(dev->nd_net, init_net()))
-		return NOTIFY_DONE;
-
-	read_lock(&packet_sklist_lock);
-	sk_for_each(sk, node, &packet_sklist) {
+	read_lock(&per_net(packet_sklist_lock, net));
+	sk_for_each(sk, node, &per_net(packet_sklist, net)) {
 		struct packet_sock *po = pkt_sk(sk);
 
 		switch (msg) {
@@ -1483,7 +1480,7 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
 			break;
 		}
 	}
-	read_unlock(&packet_sklist_lock);
+	read_unlock(&per_net(packet_sklist_lock, net));
 	return NOTIFY_DONE;
 }
 
@@ -1851,12 +1848,12 @@ static struct notifier_block packet_netdev_notifier = {
 };
 
 #ifdef CONFIG_PROC_FS
-static inline struct sock *packet_seq_idx(loff_t off)
+static inline struct sock *packet_seq_idx(net_t net, loff_t off)
 {
 	struct sock *s;
 	struct hlist_node *node;
 
-	sk_for_each(s, node, &packet_sklist) {
+	sk_for_each(s, node, &per_net(packet_sklist, net)) {
 		if (!off--)
 			return s;
 	}
@@ -1865,21 +1862,24 @@ static inline struct sock *packet_seq_idx(loff_t off)
 
 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	read_lock(&packet_sklist_lock);
-	return *pos ? packet_seq_idx(*pos - 1) : SEQ_START_TOKEN;
+	net_t net = net_from_voidp(seq->private);
+	read_lock(&per_net(packet_sklist_lock, net));
+	return *pos ? packet_seq_idx(net, *pos - 1) : SEQ_START_TOKEN;
 }
 
 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
+	net_t net = net_from_voidp(seq->private);
 	++*pos;
 	return  (v == SEQ_START_TOKEN) 
-		? sk_head(&packet_sklist) 
+		? sk_head(&per_net(packet_sklist, net)) 
 		: sk_next((struct sock*)v) ;
 }
 
 static void packet_seq_stop(struct seq_file *seq, void *v)
 {
-	read_unlock(&packet_sklist_lock);		
+	net_t net = net_from_voidp(seq->private);
+	read_unlock(&per_net(packet_sklist_lock, net));
 }
 
 static int packet_seq_show(struct seq_file *seq, void *v) 
@@ -1915,7 +1915,22 @@ static struct seq_operations packet_seq_ops = {
 
 static int packet_seq_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &packet_seq_ops);
+	struct seq_file *seq;
+	int res;
+	res = seq_open(file, &packet_seq_ops);
+	if (!res) {
+		seq = file->private_data;
+		seq->private = net_to_voidp(get_net(PROC_NET(inode)));
+	}
+	return res;
+}
+
+static int packet_seq_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq=  file->private_data;
+	net_t net = net_from_voidp(seq->private);
+	put_net(net);
+	return seq_release(inode, file);
 }
 
 static struct file_operations packet_seq_fops = {
@@ -1923,15 +1938,37 @@ static struct file_operations packet_seq_fops = {
 	.open		= packet_seq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= seq_release,
+	.release	= packet_seq_release,
 };
 
 #endif
 
+static int packet_net_init(net_t net)
+{
+	rwlock_init(&per_net(packet_sklist_lock, net));
+	INIT_HLIST_HEAD(&per_net(packet_sklist, net));
+
+	if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void packet_net_exit(net_t net)
+{
+	proc_net_remove(net, "packet");
+}
+
+static struct pernet_operations packet_net_ops = {
+	.init = packet_net_init,
+	.exit = packet_net_exit,
+};
+
+
 static void __exit packet_exit(void)
 {
-	proc_net_remove(init_net(), "packet");
 	unregister_netdevice_notifier(&packet_netdev_notifier);
+	unregister_pernet_subsys(&packet_net_ops);
 	sock_unregister(PF_PACKET);
 	proto_unregister(&packet_proto);
 }
@@ -1944,8 +1981,8 @@ static int __init packet_init(void)
 		goto out;
 
 	sock_register(&packet_family_ops);
+	register_pernet_subsys(&packet_net_ops);
 	register_netdevice_notifier(&packet_netdev_notifier);
-	proc_net_fops_create(init_net(), "packet", 0, &packet_seq_fops);
 out:
 	return rc;
 }
-- 
1.4.4.1.g278f