From 5bc318633fdf2c5bfea88bf2cf03e5aac2e78a1d Mon Sep 17 00:00:00 2001
From: Harald Hoyer <harald@redhat.com>
Date: Wed, 29 Jun 2016 17:26:17 +0200
Subject: [PATCH] network: dhcp before parsing specified dns through cmdline

I met a problem when passing kdump dns to dracut via "nameserver=x.x.x.x",
the dns I provided didn't appear in the "/etc/resolv.conf".

After some debugging, found that when setup dhcp DNS, in setup_interface()
and setup_interface6(), it has:
    echo "search $search $domain" > /tmp/net.$netif.resolv.conf

So if "$search $domain" isn't NULL(this is ture in my kdump environment),
the dns contents(that is, dns1, dns2, nameserver) in "ifup" before dhcp
will be discarded.

This patch addresses it by handling dhcp first. In fact this is also the
way the NetworkManager in 1st kernel works.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>

cherry-pick of commit cf376023e6d0d4abd9816fa954bb917fc2557713
---
 modules.d/40network/ifup.sh | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/modules.d/40network/ifup.sh b/modules.d/40network/ifup.sh
index 37f51b9..19b7bbd 100755
--- a/modules.d/40network/ifup.sh
+++ b/modules.d/40network/ifup.sh
@@ -350,16 +350,15 @@ fi
 ip=$(getarg ip)
 
 if [ -z "$ip" ]; then
-    for s in $(getargs nameserver); do
-        [ -n "$s" ] || continue
-        echo nameserver $s >> /tmp/net.$netif.resolv.conf
-    done
-
     if [ "$netroot" = "dhcp6" ]; then
         do_dhcp -6
     else
         do_dhcp -4
     fi
+    for s in $(getargs nameserver); do
+        [ -n "$s" ] || continue
+        echo nameserver $s >> /tmp/net.$netif.resolv.conf
+    done
 fi
 
 
@@ -386,17 +385,6 @@ for p in $(getargs ip=); do
     [ "$use_bridge" != 'true' ] && \
     [ "$use_vlan" != 'true' ] && continue
 
-    # setup nameserver
-    for s in "$dns1" "$dns2" $(getargs nameserver); do
-        [ -n "$s" ] || continue
-        echo nameserver $s >> /tmp/net.$netif.resolv.conf
-    done
-
-    # Store config for later use
-    for i in ip srv gw mask hostname macaddr dns1 dns2 mtu; do
-        eval '[ "$'$i'" ] && echo '$i'="$'$i'"'
-    done > /tmp/net.$netif.override
-
     for autoopt in $(str_replace "$autoconf" "," " "); do
         case $autoopt in
             dhcp|on|any)
@@ -412,6 +400,17 @@ for p in $(getargs ip=); do
     done
     ret=$?
 
+    # setup nameserver
+    for s in "$dns1" "$dns2" $(getargs nameserver); do
+        [ -n "$s" ] || continue
+        echo nameserver $s >> /tmp/net.$netif.resolv.conf
+    done
+
+    # Store config for later use
+    for i in ip srv gw mask hostname macaddr dns1 dns2 mtu; do
+        eval '[ "$'$i'" ] && echo '$i'="$'$i'"'
+    done > /tmp/net.$netif.override
+
     if [ $ret -eq 0 ]; then
         > /tmp/net.${netif}.up