iproute2 fails to work with certain device names

["Leonhard Preis" <leonhard@pre.is>]

Hi!

iproute2’s ip utility fails to execute commands properly if one specifies  
any of the four device names h, he, hel, and help and only prints out  
usage information.

Expected behaviour for a non-existing device:

% ip link show dev  
hello                                                                                                                                                                      
:(
Device "hello" does not exist.

Expected behaviour for an existing device:

% ip link show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode  
DEFAULT group default
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

Behaviour observed for both existing and absent devices called either h,  
he, hel or help:

% ip link show dev  
hel                                                                                                                                                                      
:(
Usage: ip link add [link DEV] [ name ] NAME
                    [ txqueuelen PACKETS ]
                    [ address LLADDR ]
                    [ broadcast LLADDR ]
                    [ mtu MTU ] [index IDX ]
                    [ numtxqueues QUEUE_COUNT ]
                    [ numrxqueues QUEUE_COUNT ]
                    type TYPE [ ARGS ]
        ip link delete DEV type TYPE [ ARGS ]

        ip link set { dev DEVICE | group DEVGROUP } [ { up | down } ]
	                  [ arp { on | off } ]
	                  [ dynamic { on | off } ]
	                  [ multicast { on | off } ]
	                  [ allmulticast { on | off } ]
	                  [ promisc { on | off } ]
	                  [ trailers { on | off } ]
	                  [ txqueuelen PACKETS ]
	                  [ name NEWNAME ]
	                  [ address LLADDR ]
	                  [ broadcast LLADDR ]
	                  [ mtu MTU ]
	                  [ netns PID ]
	                  [ netns NAME ]
			  [ alias NAME ]
	                  [ vf NUM [ mac LLADDR ]
				   [ vlan VLANID [ qos VLAN-QOS ] ]
				   [ rate TXRATE ] ]
				   [ spoofchk { on | off} ] ]
				   [ state { auto | enable | disable} ] ]
			  [ master DEVICE ]
			  [ nomaster ]
			  [ addrgenmode { eui64 | none } ]
        ip link show [ DEVICE | group GROUP ] [up] [master DEV] [type TYPE]
        ip link help [ TYPE ]

TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | macvtap |
           bridge | bond | ipoib | ip6tnl | ipip | sit | vxlan |
           gre | gretap | ip6gre | ip6gretap | vti | nlmon |
           bond_slave }

I successfully reproduced this on Debian Wheezy (iproute2 version  
3.16.0-2~bpo70+1) and Arch Linux (iproute2 version 3.19.0-1).

While the general origin of this problem seems quite clear, I’m left to  
wonder whether this is on purpose or not. Since I did not hit any other  
obstacles with the device name I chose I came to the conclusion that this  
may be a bug and it would be terrific if it could be fixed. For now I’ll  
perhaps simply change my device name - another l at the end will do the  
job. ;)

Please let me know if I could be of any further assistance or if this  
report is missing vital information.

Thank you!

Cheers,
Leonhard

PS: I read in another thread that this mailing list is the "bug tracker"  
for iproute2. I hope that statement is still true. It was my best shot at  
the correct bug tracker.

-- 
Mit freundlichen Grüßen // Avec mes meilleures salutations // Best Regards
Leonhard Preis