[PATCH] connman: get the correct network interface name from dmesg during NFS booting

[Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>]

Following are the drawbacks with the current logic:
1. If ip=dhcp in the boot command line, then the
current code makes connman to ignore "eth0" network interface
from managing internet connections. This can cause NFS boot
failure, if the network interface used for NFS booting 
is other than "eth0".

2. If ip=bootp in the boot command line, then none of the
network interfaces are ignored. This makes connman to manage
internet connections on every active network interfaces
(including the network interface used for NFS booting), resulting
hang during NFS boot.

This patch finds the network interface used for NFS booting via dmesg.
It searches for "device=" string from dmesg output and finds
name of network interface used for NFS. The "device=" string
is printed from dmesg, if IPCONFIG_SILENT macro is disabled
in the kernel, and this macro is disabled by default.

If "device=" string is not found, then falls back to earlier logic.
The earlier logic of detecting NFS network interface is retained, as
we cannot determine the exact network interface name used during
NFS bootup.

Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>
---
 meta/recipes-connectivity/connman/connman/connman | 35 +++++++++++++----------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/meta/recipes-connectivity/connman/connman/connman b/meta/recipes-connectivity/connman/connman/connman
index c64fa0d..aae2ca6 100644
--- a/meta/recipes-connectivity/connman/connman/connman
+++ b/meta/recipes-connectivity/connman/connman/connman
@@ -29,23 +29,28 @@ done
 do_start() {
 	EXTRA_PARAM=""
 	if test $nfsroot -eq 1 ; then
-	    NET_DEVS=`cat /proc/net/dev | sed -ne 's/^\([a-zA-Z0-9 ]*\):.*$/\1/p'`
-	    NET_ADDR=`cat /proc/cmdline | sed -ne 's/^.*ip=\([^ :]*\).*$/\1/p'`
+	    ethn_from_dmesg=`dmesg | grep "device="| sed "s|\(.*\)device=\(.*\), hwaddr=\(.*\)|\2|g"`
+	    if [ ! -z "$ethn_from_dmesg" ]; then
+		EXTRA_PARAM="-I $ethn_from_dmesg"
+	    else
+		NET_DEVS=`cat /proc/net/dev | sed -ne 's/^\([a-zA-Z0-9 ]*\):.*$/\1/p'`
+		NET_ADDR=`cat /proc/cmdline | sed -ne 's/^.*ip=\([^ :]*\).*$/\1/p'`
 
-	    if [ ! -z "$NET_ADDR" ]; then
-		if [ "$NET_ADDR" = dhcp ]; then
-		    ethn=`ifconfig | grep "^eth" | sed -e "s/\(eth[0-9]\)\(.*\)/\1/"`
-		    if [ ! -z "$ethn" ]; then
-			EXTRA_PARAM="-I $ethn"
-		    fi
-		else
-		    for i in $NET_DEVS; do
-			ADDR=`ifconfig $i | sed 's/addr://g' | sed -ne 's/^.*inet \([0-9.]*\) .*$/\1/p'`
-			if [ "$NET_ADDR" = "$ADDR" ]; then
-			    EXTRA_PARAM="-I $i"
-			    break
+		if [ ! -z "$NET_ADDR" ]; then
+		    if [ "$NET_ADDR" = dhcp ]; then
+			ethn=`ifconfig | grep "^eth" | sed -e "s/\(eth[0-9]\)\(.*\)/\1/"`
+			if [ ! -z "$ethn" ]; then
+			    EXTRA_PARAM="-I $ethn"
 			fi
-		    done
+		    else
+			for i in $NET_DEVS; do
+			    ADDR=`ifconfig $i | sed 's/addr://g' | sed -ne 's/^.*inet \([0-9.]*\) .*$/\1/p'`
+			    if [ "$NET_ADDR" = "$ADDR" ]; then
+				EXTRA_PARAM="-I $i"
+				break
+			    fi
+			done
+		    fi
 		fi
 	    fi
 	fi
-- 
2.7.4