[NET]: Make AF_PACKET handle multiple network namespaces

This is done by making packet_sklist_lock and packet_sklist per
network namespace and adding an additional filter condition on
received packets to ensure they came from the proper network
namespace.

Changes from v1:
- prohibit to call inet_dgram_ops.ioctl in other than init_net

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 89 insertions, 46 deletions

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 90802a668c23..4d0d6349aa7e 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -32,6 +32,10 @@ struct net {
         struct hlist_head       *dev_index_head;
 
         struct sock             *rtnl;                  /* rtnetlink socket */
+
+        /* List of all packet sockets. */
+        rwlock_t                packet_sklist_lock;
+        struct hlist_head       packet_sklist;
 };
 
 #ifdef CONFIG_NET
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 8a7807dbba01..45e3cbcb2763 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -135,10 +135,6 @@ dev->hard_header == NULL (ll header is added by device, we cannot control it)
    packet classifier depends on it.
  */
 
-/* List of all packet sockets. */
-static HLIST_HEAD(packet_sklist);
-static DEFINE_RWLOCK(packet_sklist_lock);
-
 /* Private packet socket structures. */
 
 struct packet_mclist
@@ -246,9 +242,6 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,  struct
         struct sock *sk;
         struct sockaddr_pkt *spkt;
 
-        if (dev->nd_net != &init_net)
-                goto out;
-
         /*
          *      When we registered the protocol we saved the socket in the data
          *      field for just this event.
@@ -270,6 +263,9 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,  struct
         if (skb->pkt_type == PACKET_LOOPBACK)
                 goto out;
 
+        if (dev->nd_net != sk->sk_net)
+                goto out;
+
         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
                 goto oom;
 
@@ -341,7 +337,7 @@ 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;
@@ -449,15 +445,15 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet
         int skb_len = skb->len;
         unsigned int snaplen, res;
 
-        if (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 (dev->nd_net != sk->sk_net)
+                goto drop;
+
         skb->dev = dev;
 
         if (dev->header_ops) {
@@ -566,15 +562,15 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
         struct sk_buff *copy_skb = NULL;
         struct timeval tv;
 
-        if (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 (dev->nd_net != sk->sk_net)
+                goto drop;
+
         if (dev->header_ops) {
                 if (sk->sk_type != SOCK_DGRAM)
                         skb_push(skb, skb->data - skb_mac_header(skb));
@@ -732,7 +728,7 @@ 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;
@@ -799,15 +795,17 @@ static int packet_release(struct socket *sock)
 {
         struct sock *sk = sock->sk;
         struct packet_sock *po;
+        struct net *net;
 
         if (!sk)
                 return 0;
 
+        net = sk->sk_net;
         po = pkt_sk(sk);
 
-        write_lock_bh(&packet_sklist_lock);
+        write_lock_bh(&net->packet_sklist_lock);
         sk_del_node_init(sk);
-        write_unlock_bh(&packet_sklist_lock);
+        write_unlock_bh(&net->packet_sklist_lock);
 
         /*
          *      Unhook packet receive handler.
@@ -916,7 +914,7 @@ 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);
@@ -943,7 +941,7 @@ 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;
         }
@@ -972,9 +970,6 @@ static int packet_create(struct net *net, struct socket *sock, int protocol)
         __be16 proto = (__force __be16)protocol; /* weird, but documented */
         int err;
 
-        if (net != &init_net)
-                return -EAFNOSUPPORT;
-
         if (!capable(CAP_NET_RAW))
                 return -EPERM;
         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
@@ -1020,9 +1015,9 @@ static int packet_create(struct net *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(&net->packet_sklist_lock);
+        sk_add_node(sk, &net->packet_sklist);
+        write_unlock_bh(&net->packet_sklist_lock);
         return(0);
 out:
         return err;
@@ -1140,7 +1135,7 @@ 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);
@@ -1165,7 +1160,7 @@ 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;
@@ -1217,7 +1212,7 @@ 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;
 
@@ -1271,7 +1266,7 @@ 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);
@@ -1299,7 +1294,7 @@ 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);
                 }
@@ -1455,12 +1450,10 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
         struct sock *sk;
         struct hlist_node *node;
         struct net_device *dev = data;
+        struct net *net = dev->nd_net;
 
-        if (dev->nd_net != &init_net)
-                return NOTIFY_DONE;
-
-        read_lock(&packet_sklist_lock);
-        sk_for_each(sk, node, &packet_sklist) {
+        read_lock(&net->packet_sklist_lock);
+        sk_for_each(sk, node, &net->packet_sklist) {
                 struct packet_sock *po = pkt_sk(sk);
 
                 switch (msg) {
@@ -1499,7 +1492,7 @@ static int packet_notifier(struct notifier_block *this, unsigned long msg, void
                         break;
                 }
         }
-        read_unlock(&packet_sklist_lock);
+        read_unlock(&net->packet_sklist_lock);
         return NOTIFY_DONE;
 }
 
@@ -1547,6 +1540,8 @@ static int packet_ioctl(struct socket *sock, unsigned int cmd,
                 case SIOCGIFDSTADDR:
                 case SIOCSIFDSTADDR:
                 case SIOCSIFFLAGS:
+                        if (sk->sk_net != &init_net)
+                                return -ENOIOCTLCMD;
                         return inet_dgram_ops.ioctl(sock, cmd, arg);
 #endif
 
@@ -1862,12 +1857,12 @@ 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(struct net *net, loff_t off)
 {
         struct sock *s;
         struct hlist_node *node;
 
-        sk_for_each(s, node, &packet_sklist) {
+        sk_for_each(s, node, &net->packet_sklist) {
                 if (!off--)
                         return s;
         }
@@ -1876,21 +1871,24 @@ 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;
+        struct net *net = seq->private;
+        read_lock(&net->packet_sklist_lock);
+        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)
 {
+        struct net *net = seq->private;
         ++*pos;
         return  (v == SEQ_START_TOKEN)
-                ? sk_head(&packet_sklist)
+                ? sk_head(&net->packet_sklist)
                 : sk_next((struct sock*)v) ;
 }
 
 static void packet_seq_stop(struct seq_file *seq, void *v)
 {
-        read_unlock(&packet_sklist_lock);
+        struct net *net = seq->private;
+        read_unlock(&net->packet_sklist_lock);
 }
 
 static int packet_seq_show(struct seq_file *seq, void *v)
@@ -1926,7 +1924,26 @@ static const 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 = get_proc_net(inode);
+                if (!seq->private) {
+                        seq_release(inode, file);
+                        res = -ENXIO;
+                }
+        }
+        return res;
+}
+
+static int packet_seq_release(struct inode *inode, struct file *file)
+{
+        struct seq_file *seq=  file->private_data;
+        struct net *net = seq->private;
+        put_net(net);
+        return seq_release(inode, file);
 }
 
 static const struct file_operations packet_seq_fops = {
@@ -1934,15 +1951,37 @@ static const 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(struct net *net)
+{
+        rwlock_init(&net->packet_sklist_lock);
+        INIT_HLIST_HEAD(&net->packet_sklist);
+
+        if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
+                return -ENOMEM;
+
+        return 0;
+}
+
+static void packet_net_exit(struct net *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);
 }
@@ -1955,8 +1994,8 @@ 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;
 }