tun: socket filter support

This patch adds Linux Socket Filter support to tun driver. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
raspberrypi · Feb 18, 2010 · 9940516 · 9940516
1 parent 5ff3f07
commit 9940516
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diff --git a/drivers/net/tun.c b/drivers/net/tun.c
@@ -61,6 +61,7 @@
 #include <linux/crc32.h>
 #include <linux/nsproxy.h>
 #include <linux/virtio_net.h>
+#include <linux/rcupdate.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
@@ -366,6 +367,10 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
  if (!check_filter(&tun->txflt, skb))
  goto drop;
 
+ if (tun->socket.sk->sk_filter &&
+ sk_filter(tun->socket.sk, skb))
+ goto drop;
+
  if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
  if (!(tun->flags & TUN_ONE_QUEUE)) {
  /* Normal queueing mode. */
@@ -1162,6 +1167,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
  struct tun_file *tfile = file->private_data;
  struct tun_struct *tun;
  void __user* argp = (void __user*)arg;
+ struct sock_fprog fprog;
  struct ifreq ifr;
  int sndbuf;
  int ret;
@@ -1309,6 +1315,26 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
  tun->socket.sk->sk_sndbuf = sndbuf;
  break;
 
+ case TUNATTACHFILTER:
+ /* Can be set only for TAPs */
+ ret = -EINVAL;
+ if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+ break;
+ ret = -EFAULT;
+ if (copy_from_user(&fprog, argp, sizeof(fprog)))
+ break;
+
+ ret = sk_attach_filter(&fprog, tun->socket.sk);
+ break;
+
+ case TUNDETACHFILTER:
+ /* Can be set only for TAPs */
+ ret = -EINVAL;
+ if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
+ break;
+ ret = sk_detach_filter(tun->socket.sk);
+ break;
+
  default:
  ret = -EINVAL;
  break;

diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
@@ -18,6 +18,7 @@
 
 #include <linux/types.h>
 #include <linux/if_ether.h>
+#include <linux/filter.h>
 
 /* Read queue size */
 #define TUN_READQ_SIZE 500
@@ -48,6 +49,8 @@
 #define TUNGETIFF _IOR('T', 210, unsigned int)
 #define TUNGETSNDBUF _IOR('T', 211, int)
 #define TUNSETSNDBUF _IOW('T', 212, int)
+#define TUNATTACHFILTER _IOW('T', 213, struct sock_fprog)
+#define TUNDETACHFILTER _IOW('T', 214, struct sock_fprog)
 
 /* TUNSETIFF ifr flags */
 #define IFF_TUN 0x0001