nameif bug reported in bug #75572

There is a bug in ifdown (I looking at initscripts-6.95-1).  When the interface
macaddr does not match the one in the config, ifdown looks for another config
file *with the same nonmatching macaddr*.  The following patch will fix this
little problem, but not the larger one.

--- ifdown.orig 2002-10-18 18:35:46.000000000 -0700
+++ ifdown      2002-10-18 18:37:57.000000000 -0700
@@ -52,7 +52,7 @@
     FOUNDMACADDR=`LC_ALL= LANG= ip -o link show ${REALDEVICE} | \
        sed 's/.*link\/ether \([[:alnum:]:]*\).*/\1/'`
     if [ "${FOUNDMACADDR}" != "${HWADDR}" ]; then
-        NEWCONFIG=`fgrep -l "HWADDR=${HWADDR}"
/etc/sysconfig/network-scripts/ifcfg-*`
+        NEWCONFIG=`fgrep -l "HWADDR=${FOUNDMACADDR}"
/etc/sysconfig/network-scripts/ifcfg-*`
        if [ -n "${NEWCONFIG}" -a "${NEWCONFIG}" != "${CONFIG}" ]; then
           exec /sbin/ifdown ${NEWCONFIG}
        else

Also we should probably decide on a standard for the case of HWADDR.  /sbin/ip
reports them lower case, but neat writes them uppercase in the config file. 
Optionally, we could just make the test case insensitive with something like

echo "$HWADDR" |fgrep -qix "$FOUNDMACADDR"

I ran into the same problem with the case of the HWADDR.  Fixing this solves the
problem for me.  I used this patch to make sure both are uppercase (allowing for
the fact that the config file might be lowercase too if hand-edited).

--- ifdown      2002-10-19 11:32:47.000000000 -0400
+++ ifdown.good 2002-10-19 11:31:43.000000000 -0400
@@ -51,6 +51,9 @@
 if [ -n "${HWADDR}" ]; then
     FOUNDMACADDR=`LC_ALL= LANG= ip -o link show ${REALDEVICE} | \
        sed 's/.*link\/ether \([[:alnum:]:]*\).*/\1/'`
+    # uppercase the mac address variables
+    FOUNDMACADDR=`echo ${FOUNDMACADDR} | tr a-f A-F`
+    HWADDR=`echo ${HWADDR} | tr a-f A-F`
     if [ "${FOUNDMACADDR}" != "${HWADDR}" ]; then
         NEWCONFIG=`fgrep -l "HWADDR=${HWADDR}"
/etc/sysconfig/network-scripts/ifcfg-*`
        if [ -n "${NEWCONFIG}" -a "${NEWCONFIG}" != "${CONFIG}" ]; then

*** Bug 76599 has been marked as a duplicate of this bug. ***

*** Bug 76598 has been marked as a duplicate of this bug. ***

Created attachment 91383 [details]
bash replacement for nameif(8)

This bug has bitten me on both RH8 and RH9 systems, and is particularly egregious
when using multiple interfaces driven by the same card -- since all interfaces get
named as soon as the module loads, nameif(8) refuses to rename (e.g.) eth2 to eth0
because eth0 already exists. I swore at this for some time and finally ended up
writing a more-or-less drop-in replacement for nameif in bash, using "ip link"
commands. This simplifies things greatly for me, and so far it works like a charm.
Attached; you can also find a copy at http://www.cs.umass.edu/~olc/pub/nameif.

Comment on attachment 91383 [details]
bash replacement for nameif(8)


#!/bin/bash

# Copyright (c) 2003 Ole Craig <olc.edu>, all rights
# reserved. This software may be freely redistributed under the terms
# of the GNU general public license. See (e.g.)
# http://www.gnu.org/licenses/gpl.txt for details. Although it is not
# required by the license terms, if you improve this script in any way
# the author would deeply appreciate seeing (and perhaps learning
# from) your changes.

# we use this script because regular nameif doesn't handle the case
# where we want to rename preexisting devices (e.g. swap eth0 <-->
# eth1) and sometimes segfaults anyway.

# quick'n'dirty method for dealing with errout (overrideable with -s)
logger="echo `basename $0[$$]`: "

function usage() {
    echo "usage: `basename $0` [-c configurationfile] [-s] {ifname macaddress}"
    exit -1
}

function loggit() {
    $logger "$*"
}

function die () {
    loggit $*
    exit -1
}
function namer() {
# this is where we do the work on a given IF
# expect 2 inputs: current name targetname
    err=`ip link set $1 name $2`
    status=$?
    if [ "$err" != "" ]; then
	$logger $err
    fi
    return $status
}

function isup() {
    # check to see if interface is active
    ip link show $1 2>&1 | cut -f3 -d" " | grep -qw UP
    return $?
}

# main body
if [ ${#*} == 0 ]; then
    # we get our parameters from /etc/mactab unless otherwise specified
    CONFFILE=/etc/mactab
else
    while [ ${#*} -gt 0 ]; do
	case $1 in
	    -s)
	    logger="logger -i -t `basename $0`"
	    shift
	    ;;
	    -c)
		if [ "$2" == "" -o ! -r $2 ]; then
		    usage
		else
		    CONFFILE=$2
		    shift
		    shift
		fi
		;;
	    *)
# we assume anything else is an interface name
		if [ "$2" == "" -o "$3" != "" ]; then
		    usage
		else
		    DES_IFNAME=$1
		    # attempt to sanitize input a bit
		    DES_MAC=`echo $2 | tr 'a-f-' 'A-F:'`
		    shift
		    shift
		fi


	esac
    done

    i=0
    BLOCKED=0
fi
if [ "$DES_IFNAME" = "" ]; then
# if we're processing a table (/etc/mactab by default) then we iterate
# through...

    itab=0
    for q in `cat $CONFFILE`; do
	MACTABLE[$itab]=$q
	let itab++
    done

# ...and recurse
    for (( q=0 ; $q < $itab ; q++)); do
	$0 ${MACTABLE[((q++))]} ${MACTABLE[$q]}
# note nasty increment of counter within loop. Ugh.
    done
else # we were given an argument, use it

# Build table of current IFs and their associated MAC addresses. While
# we're at it, grab current values for IF name and IF/MAC of blocking
# name, if any.  If we only have one MAC address as input, then we
# scan the table of available IFs for a match. If that MAC is
# currently in use by another IF name, we swap. Otherwise, we just
# name it. (Or leave it alone, as may be the case.)

# DES_IFNAME is the desired name for the mac address supplied on commandline.

    i=0
    GETMAC=0
    for q in `ifconfig -a | grep -E ^eth | awk '{ print $1" "$5 }'`; do
	MACDESK[$i]=$q
	if [ "$GETMAC" != "0" ]; then
	    CUR_MAC=$q
	    GETMAC=0
	fi
	if [ "$q" == "$DES_MAC" ]; then
	    CUR_IFNAME=${MACDESK[$i-1]}
	fi
	if [ "$q" == "$DES_IFNAME" ]; then
	    BLOCKED=1
	    GETMAC=1
	fi
	let i++
    done

# CUR_IFNAME is the current name for the mac address supplied on commandline.
# if $CUR_IFNAME is empty at this point, then we don't have an
# interface with this MAC address

if [ "$CUR_IFNAME" == "" ]; then
    die "no interface found with requested MAC address \"$DES_MAC\""
fi

# swap "blocked" names
    isup $DES_IFNAME && die "$DES_IFNAME ($CUR_MAC) already active"
    isup $CUR_IFNAME && die "$CUR_IFNAME ($DES_MAC) already active"
    if [ "$CUR_IFNAME" == "$DES_IFNAME" ]; then
	exit 0 # everything's jake, current and desired IF names are the same
    fi
    if [ $BLOCKED == 1 ]; then
	namer $DES_IFNAME nameif_tmp$DES_IFNAME
	namer $CUR_IFNAME $DES_IFNAME
	namer nameif_tmp$DES_IFNAME $CUR_IFNAME
    else
	namer $CUR_IFNAME $DES_IFNAME
    fi

fi

Comment on attachment 91383 [details]
bash replacement for nameif(8)


#!/bin/bash

# Copyright (c) 2003 Ole Craig <olc.edu>, all rights
# reserved. This software may be freely redistributed under the terms
# of the GNU general public license. See (e.g.)
# http://www.gnu.org/licenses/gpl.txt for details. Although it is not
# required by the license terms, if you improve this script in any way
# the author would deeply appreciate seeing (and perhaps learning
# from) your changes.

# we use this script because regular nameif doesn't handle the case
# where we want to rename preexisting devices (e.g. swap eth0 <-->
# eth1) and sometimes segfaults anyway.

# quick'n'dirty method for dealing with errout (overrideable with -s)
logger="echo `basename $0[$$]`: "

function usage() {
    echo "usage: `basename $0` [-c configurationfile] [-s] {ifname macaddress}"
    exit -1
}

function loggit() {
    $logger "$*"
}

function die () {
    loggit $*
    exit -1
}
function namer() {
# this is where we do the work on a given IF
# expect 2 inputs: current name targetname
    err=`ip link set $1 name $2`
    status=$?
    if [ "$err" != "" ]; then
	$logger $err
    fi
    return $status
}

function isup() {
    # check to see if interface is active
    ip link show $1 2>&1 | cut -f3 -d" " | grep -qw UP
    return $?
}

# main body
if [ ${#*} == 0 ]; then
    # we get our parameters from /etc/mactab unless otherwise specified
    CONFFILE=/etc/mactab
else
    while [ ${#*} -gt 0 ]; do
	case $1 in
	    -s)
	    logger="logger -i -t `basename $0`"
	    shift
	    ;;
	    -c)
		if [ "$2" == "" -o ! -r $2 ]; then
		    usage
		else
		    CONFFILE=$2
		    shift
		    shift
		fi
		;;
	    *)
# we assume anything else is an interface name
		if [ "$2" == "" -o "$3" != "" ]; then
		    usage
		else
		    DES_IFNAME=$1
		    # attempt to sanitize input a bit
		    DES_MAC=`echo $2 | tr 'a-f-' 'A-F:'`
		    shift
		    shift
		fi


	esac
    done

    i=0
    BLOCKED=0
fi
if [ "$DES_IFNAME" = "" ]; then
# if we're processing a table (/etc/mactab by default) then we iterate
# through...

    itab=0
    for q in `cat $CONFFILE`; do
	MACTABLE[$itab]=$q
	let itab++
    done

# ...and recurse
    for (( q=0 ; $q < $itab ; q++)); do
	$0 ${MACTABLE[((q++))]} ${MACTABLE[$q]}
# note nasty increment of counter within loop. Ugh.
    done
else # we were given an argument, use it

# Build table of current IFs and their associated MAC addresses. While
# we're at it, grab current values for IF name and IF/MAC of blocking
# name, if any.  If we only have one MAC address as input, then we
# scan the table of available IFs for a match. If that MAC is
# currently in use by another IF name, we swap. Otherwise, we just
# name it. (Or leave it alone, as may be the case.)

# DES_IFNAME is the desired name for the mac address supplied on commandline.

    i=0
    GETMAC=0
    for q in `ifconfig -a | grep -E ^eth | awk '{ print $1" "$5 }'`; do
	MACDESK[$i]=$q
	if [ "$GETMAC" != "0" ]; then
	    CUR_MAC=$q
	    GETMAC=0
	fi
	if [ "$q" == "$DES_MAC" ]; then
	    CUR_IFNAME=${MACDESK[$i-1]}
	fi
	if [ "$q" == "$DES_IFNAME" ]; then
	    BLOCKED=1
	    GETMAC=1
	fi
	let i++
    done

# CUR_IFNAME is the current name for the mac address supplied on commandline.
# if $CUR_IFNAME is empty at this point, then we don't have an
# interface with this MAC address

if [ "$CUR_IFNAME" == "" ]; then
    die "no interface found with requested MAC address \"$DES_MAC\""
fi

# swap "blocked" names
    isup $DES_IFNAME && die "$DES_IFNAME ($CUR_MAC) already active"
    isup $CUR_IFNAME && die "$CUR_IFNAME ($DES_MAC) already active"
    if [ "$CUR_IFNAME" == "$DES_IFNAME" ]; then
	exit 0 # everything's jake, current and desired IF names are the same
    fi
    if [ $BLOCKED == 1 ]; then
	namer $DES_IFNAME nameif_tmp$DES_IFNAME
	namer $CUR_IFNAME $DES_IFNAME
	namer nameif_tmp$DES_IFNAME $CUR_IFNAME
    else
	namer $CUR_IFNAME $DES_IFNAME
    fi

fi

Aaaah!

Sorry about that. The original attachment was bogus -- I grabbed the old nameif
instead of my replacement. Then, misunderstanding some bugzilla functionality
that I don't often use, I tried to rectify my mistake by replacing the attachment
with the correct file... Sigh. Compound that with a cached POST operation, and 

Anyway, there it is. Sorry for the extra pagefiller.

Created attachment 91386 [details]
drop-in replacement for nameif(8)

The real bashful nameif...

I was burned by this bug, too. The source of my problem was the configuration 
files /etc/sysconfig/network-scripts/ifcfg-eth? and /etc/sysconfig/networking.

I upgraded my system, replacing a NIC with an ethernet driver built into the 
motherboard. This made the MAC addresses in the configuration files incorrect. 
Also, redhat-config-network put DEVICE=eth1 in my eth0 file and vice versa.

After upgrading, the MAC confusion failed the weak FOUNDMACADDR test, and the 
swapped device assignments assured that the script would invoke itself forever 
through exec.

Any of the suggestions in this bug report would have caught my problems.

Something similar to this (but different) is in both RHEL3 and Fedora Core.