[kexec-tools] module-setup: Use proper ethernet device name in 2nd kernel

[WANG Chao]

commit 08809fb0c7adf6b2ffd1a44228d0111c808b4b9f
Author: Minfei Huang <mhuang at redhat.com>
Date:   Fri Dec 5 14:46:15 2014 +0800

    module-setup: Use proper ethernet device name in 2nd kernel
    
    For ethX, it may fail to setup the network in the 2nd kernel due to the
    mapping of ethernet device name and MAC changes.
    
    The commit(ba7660f37e792be082b7e0c9e73b76647db5e902) has fixed this
    issue by add the prefix "kdump-" before ethX. But the network will fail
    to work in the static route mode because of this commit.
    
    Here is the config which is used to setup the static route:
    rd.route=192.168.201.215:192.168.200.137:eth1
    
    Obviously, the static route config comtains the ethX. But the network
    device names kdump-ethX in the 2nd kernel, so the static route config
    will fail to execute. To fix it, we should identify the network device.
    
    Add the prefix "kdump-" before the ethX in the static route config to
    setup it successfully in the 2nd kernel.
    
    Signed-off-by: Minfei Huang <mhuang at redhat.com>
    Acked-by: WANG Chao <chaowang at redhat.com>
    Acked-by: Baoquan He <bhe at redhat.com>

 dracut-module-setup.sh |   23 ++++++++++++++---------
 1 files changed, 14 insertions(+), 9 deletions(-)
---
diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index 9299b5d..f0d3311 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -209,20 +209,25 @@ kdump_setup_znet() {
 
 get_routes() {
     local _netdev="$1" _target="$2"
-    local _route
+    local _route _nexthop
 
     _route=`/sbin/ip route get to $_target 2>&1`
-    if /sbin/ip route get to $_target | grep -q "via";
-    then
+#
+# in the same subnet region, following is the route format
+# _route='192.168.200.137 dev eth1  src 192.168.200.129
+#   cache '
+#
+# in the different subnet region, following is the route format
+# _route='192.168.201.215 via 192.168.200.137 dev eth1  src 192.168.200.129
+#   cache '
+#
+    if `echo $_route | grep -q "via"`; then
         # route going to a different subnet via a router
-        echo $_route | awk '{printf("rd.route=%s:%s:%s\n", $1, $3, $5)}' \
-            >> ${initdir}/etc/cmdline.d/45route-static.conf
-    else
-        # route going to a different subnet though directly connected
-        echo $_route | awk '{printf("rd.route=%s::%s\n", $1, $3)}' \
-            >> ${initdir}/etc/cmdline.d/45route-static.conf
+        _nexthop=`echo $_route | awk '{print $3}'`
     fi
+    _netdev=$(kdump_setup_ifname $_netdev)
 
+    echo "rd.route=$_target:$_nexthop:$_netdev" >> ${initdir}/etc/cmdline.d/45route-static.conf
 }
 
 # Setup dracut to bringup a given network interface