Bug 169749

Created attachment 119522 [details]
a proposed patch for network-functions (it makes things to work for me again)

I'm sorry, I'm not following in general - can you give some example configs of
yours that trip this up?

OK, for whatever reasons I have now a box with two profiles which can be
switched in between (plus a regular "Common", a.k.a. "default" which does not
"own" any interfaces as that would mess up switching very badly).

One of these profiles configures interfaces eth0, eth0:0, eth0:1 and eth1
with eth0 getting its address over DHCP and all other interfaces static.
Corresponding configuration files happen to be called 'ifcfg-eth0spare',
'ifcfg-eth0:0spare', 'ifcfg-eth0:1spare' and 'ifcfg-eth1spare' (although these
names could be something different but not like 'ifcfg-eth0' as these names
are already used by the other profile and all files in
/etc/sysconfig/networking/devices/ are different even if they refer to the
same interfaces)

Files 'ifcfg-eth0:0spare' and 'ifcfg-eth0:1spare' were created by "Copy"
operation in 'neat' and later by editing their content so, not quite naturally,
all of the share the same 'HWADDR=...' line.  Of course _none_ of these
three files would have to have that line but it happens to be there.

All of that works fine on starting, stopping and configuring all interfaces
if I am using 'need_config()' patched as above.  Otherwise I am seeing what
is described in the original report.

Also a trivial shell script which sources 'network-functions', runs 'need_config'
with an argument passed to it and echos resulting $CONFIG works correctly
with any interface argument and any profile.  Without that patch everything
is fine when config files used happen to have names like 'ifcfg-eth0',
'ifcfg-eth0:1', and so on (which is not very surprising) but I am getting
obviously wrong results otherwise.

Note that when you are searching for a configuration file by a hardware
address it would not help to do 'grep ... | head -1'.  You have no idea
that the file you want would come on the top.

OTOH somebody could have put some extra comments on 'DEVICE=...' line
so instead of using blindly grep it would be more prudent source these
files one by one in a subshell, so we will not mess up other assignments,
and echo a file name on a match.  Something like that:

  ( for f in /etc/sysconfig/network-scripts/ifcfg-* ; do
        [ -r $f ] || continue
        source $f
        if [ "$DEVICE" = "${1}" ]; then echo $f; break; fi
    done )

Similar would also be likely more robust if one has to resort to a search
by HWADDR but then I do not know of a simple way of a case independent string
comparison, even if bash has down(up)casing functions, without invoking some
external programs (and 'tr' is in /usr/bin although 'awk' is /bin/awk).
It is possible though, in shell, to split MACs and compare hexadecimal numbers.

So, the case you're talking about essentially boils down to:

ifcfg-$NAME where $NAME != $DEVICE.
and $HWADDR is in multiple of these files.

Correct?

> Correct?

Yes, that is what I indeed wrote in the original report but you wanted
a specific example.  Such configuration is neither incorrect nor unusual
(if not so frequent).

That could be even better for a search loop as it avoids a basename call.

  ( for f in /etc/sysconfig/network-scripts/ifcfg-* ; do
        [ -r $f ] || continue
        source $f
        if [ "$DEVICE" = "${1}" ]; then echo ${f##*/}; break; fi
    done )

When I started to look at 'network-functions' then I noticed that 'get_hwaddr'
can be simplified to:

    LC_ALL= LANG= ip -o link show ${1} 2>/dev/null | \
      awk '{ print toupper($(NF - 2)) }'

and if you do not want to count fields then you can do

      awk -F'link/[^ ]*  *' '{sub(/ .*/,"", $2); print toupper($2)}'

instead.  I think that the first version is fine.

Also in 'is_available' a line

 if [ -z "$alias" -o "$alias" = "off" -o "$alias" = "/bin/true" ]; then

should read

 if [ -z "$alias" -o "$alias" = "off" -o \
       "$alias" = "/bin/true" -o "$alias" = ":" ]; then

Fixed in CVS.  I have moved the grep for DEVICE= after the HWADDR lookup because
HWADDR is generally more specific than a device name, and alias configuration
files should not contain HWADDR.

Thanks for the patches!

*** Bug 196324 has been marked as a duplicate of this bug. ***