[TUNTAP]: Allow setting the linktype of the tap device from userspace
Currently tun/tap only supports the EN10MB ARP type. For use with
wireless and other networking types it should be possible to set the
ARP type via an ioctl.
Patch v2: Included check that the tap interface is down before changing the
link type out from underneath it
Signed-off-by: Mike Kershaw <dragorn@kismetwireless.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index effab0b..50b8c67 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -18,6 +18,9 @@
/*
* Changes:
*
+ * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
+ * Add TUNSETLINK ioctl to set the link encapsulation
+ *
* Mark Smith <markzzzsmith@yahoo.com.au>
* Use random_ether_addr() for tap MAC address.
*
@@ -612,6 +615,18 @@
DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
break;
+ case TUNSETLINK:
+ /* Only allow setting the type when the interface is down */
+ if (tun->dev->flags & IFF_UP) {
+ DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
+ tun->dev->name);
+ return -EBUSY;
+ } else {
+ tun->dev->type = (int) arg;
+ DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
+ }
+ break;
+
#ifdef TUN_DEBUG
case TUNSETDEBUG:
tun->debug = arg;
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 096a85a..88aef7b 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -77,6 +77,7 @@
#define TUNSETIFF _IOW('T', 202, int)
#define TUNSETPERSIST _IOW('T', 203, int)
#define TUNSETOWNER _IOW('T', 204, int)
+#define TUNSETLINK _IOW('T', 205, int)
/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001