Bug#812886: net-tools: ifconfig doesn't show interface

[Andrey Melnikov]

2016-01-28 15:48 GMT+03:00 Martín Ferrari <tincho at tincho.org>:
> On 27/01/16 16:53, Andrey Melnikov wrote:
>
>> ifconfig doesn't show interface (lxcbr0 on my config).
>
> Does it show it if you run 'ifconfig -a'? And if you configure ip addresses?
No.

# brctl addbr testbr && ip link set dev testbr up
# brctl addbr testbr0 && ip link set dev testbr0 up
# brctl addbr testbr1 && ip link set dev testbr1 up

# ./ifconfig  -a | grep testbr
testbr0   Link encap:Ethernet  HWaddr b2:d0:d7:30:d2:02
testbr1   Link encap:Ethernet  HWaddr 5a:4f:05:b8:68:bc

# ip link  | grep testbr
73: testbr: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN mode DEFAULT group default qlen 1000
74: testbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN mode DEFAULT group default qlen 1000
75: testbr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN mode DEFAULT group default qlen 1000

# ip add add 10.1.0.1/24 dev testbr
# ip add add 10.2.0.1/24 dev testbr0
# ip add add 10.3.0.1/24 dev testbr1

# ./ifconfig  -a | grep testbr
testbr0   Link encap:Ethernet  HWaddr b2:d0:d7:30:d2:02
testbr1   Link encap:Ethernet  HWaddr 5a:4f:05:b8:68:bc

# ip -4 add | grep testbr
73: testbr: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN group default qlen 1000
    inet 10.1.0.1/24 scope global testbr
74: testbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN group default qlen 1000
    inet 10.2.0.1/24 scope global testbr0
75: testbr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UNKNOWN group default qlen 1000
    inet 10.3.0.1/24 scope global testbr1

# ./ifconfig testbr
testbr0   Link encap:Ethernet  HWaddr b2:d0:d7:30:d2:02
          inet addr:10.2.0.1  Bcast:0.0.0.0  Mask:255.255.255.0
          inet6 addr: fe80::b0d0:d7ff:fe30:d202/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:648 (648.0 B)

total mess. But "./ifconfig testbr 10.4.0.1 netmask 255.255.255.0"
configure right interface, this is good.


> In any case, this bug does not seem to be severity:important, nor
> deserving an upload to stable, which usually only happens for security
> issues.

If some user scripts parse output of this broken ifconfig - it may
configure firewall with wrong IP address or any other service.

This bug fixed 2 year ago in net-tools git:

commit 12f5a0c5db56f035350330a4fe7081f6b61deb37
Author: Jiri Popelka <jpopelka at redhat.com>
Date:   Mon Oct 21 10:58:56 2013 +0200

    Fix nstrcmp() to prevent ifconfig from showing duplicate interfaces.

    Patch from TAKADA Yoshihito
    https://bugzilla.redhat.com/show_bug.cgi?id=1021109