modem.sh: warn users if executing without root permissions

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/networking/modem/device-files/modem.sh b/networking/modem/device-files/modem.sh
index 626593b..b27aadd 100755
--- a/networking/modem/device-files/modem.sh
+++ b/networking/modem/device-files/modem.sh
@@ -34,10 +34,50 @@ usage()
 	exit 1
 }
 
+check_permissions()
+{
+	modem_command="$1"
+	root_access="$(getprop persist.sys.root_access)"
+	uid="$(id -u)"
+
+	# 0: Root access: Disabled, 2: Root access: ADB only
+	#    For both the terminal application and ADB we have something
+	#    like that:
+	#        shell@i9100:/ $ su
+	#        255|shell@i9100:/ $
+	# 1: Root access: Apps only
+	#    From ADB:
+	#        shell@i9100:/ $ su
+	#        Permission denied
+	#        1|shell@i9100:/ $
+	#    From the terminal application
+	#        u0_a51@i9100:/ $ su
+	#        root@i9100:/ #
+	if [ "${uid}" != "0" ] ; then
+	    echo ""
+	    echo "This script requires root."
+	    echo "To give it root:"
+	    case "${root_access}" in
+		"0"|"1"|"2")
+		    echo "- Go in Settings"
+		    echo "- Go in Developer options"
+		    echo "- Select Root access"
+		    echo "- Set it to \"Apps and ADB\""
+		    ;;
+	    esac
+	    echo "- Run these 2 commands:"
+	    echo "  su"
+	    echo "  modem.sh ${modem_command}"
+	    exit 1
+	fi
+}
+
 modem()
 {
 	command="$1"
 
+	check_permissions "${command}"
+
 	echo "Remounting system partition as writable..."
 	mount -o rw,remount /system