Name
dev_get_by_index_rcu — 
     find a device by its ifindex
 
Arguments
- net
- 
     the applicable net namespace
     
- ifindex
- 
     index of device
     
Description
   Search for an interface by index. Returns NULL if the device
   is not found or a pointer to the device. The device has not
   had its reference counter increased so the caller must be careful
   about locking. The caller must hold RCU lock.