[Buildroot] [PATCH v3] set simple network setup via the system configuration submenu

["André Erdmann" <dywi@mailerd.de>]

Hi,


2014/10/24 Jeremy Rosen <jeremy.rosen@openwide.fr>:
> diff --git a/support/scripts/generate-network-config.sh b/support/scripts/generate-network-config.sh
> new file mode 100755
> index 0000000..c09d165
> --- /dev/null
> +++ b/support/scripts/generate-network-config.sh
> @@ -0,0 +1,136 @@
> +#!/bin/sh
> +
> +#extract our parameters from the config file
> +# see comment in support/scripts/mkusers at to why we can't simply source
> +for PARAM in \
> +	BR2_PACKAGE_SYSTEMD_NETWORKD \
> +	BR2_SIMPLE_NETWORK_NONE \
> +	BR2_SIMPLE_NETWORK_IPV4_DHCP \
> +	BR2_SIMPLE_NETWORK_IPV4_MANUAL \
> +	; do
> +TMP=$(sed -r -e "/^$PARAM=(.*)$/!d;" -e 's//\1/;' $BR2_CONFIG)
> +export $PARAM=$TMP
> +done
> +
> +for PARAM in \
> +	BR2_SIMPLE_NETWORK_NAME \
> +	BR2_SIMPLE_NETWORK_IPV4_ADDRESS \
> +	BR2_SIMPLE_NETWORK_IPV4_NETMASK \
> +	BR2_SIMPLE_NETWORK_IPV4_BROADCAST \
> +	BR2_SIMPLE_NETWORK_IPV4_GATEWAY \
> +	; do
> +TMP=$(sed -r -e "/^$PARAM=\"(.*)\"$/!d;" -e 's//\1/;' $BR2_CONFIG)
> +export $PARAM="$TMP"
> +done
> +
> +check_configuration ()
> +{
> +	if [ -z "$BR2_SIMPLE_NETWORK_NONE" ] ; then
> +		if [ -z "$BR2_SIMPLE_NETWORK_NAME" ] ; then
> +			echo ERROR no name specified for first network interface
> +			exit 1
> +		fi
> +		if [ "$BR2_SIMPLE_NETWORK_IPV4_MANUAL" ] ; then
> +			if [ -z "$BR2_SIMPLE_NETWORK_IPV4_ADDRESS" ] ; then
> +				echo ERROR BR2_SIMPLE_NETWORK_IPV4_ADDRESS not set 1>&2
> +				exit 1
> +			fi
> +			if [ -z "$BR2_SIMPLE_NETWORK_IPV4_NETMASK" ] ; then
> +				echo ERROR BR2_SIMPLE_NETWORK_IPV4_NETMASK not set 1>&2
> +				exit 1
> +			fi

Not strictly necessary(*), but it's safer to back up the old field separator and
restore it later on:

OLDIFS="$IFS"; IFS=.


(*) otherwise, the script could misbehave if TARGET_DIR contains dot "." chars:

  TARGET_DIR="/tmp/br.foo/..."
  echo > $TARGET_DIR/x   =expands-to=>   echo > /tmp/br foo/.../x

> +			IFS=.
> +			for dec in $BR2_SIMPLE_NETWORK_IPV4_NETMASK ; do
> +				case $dec in
> +					255 | 254 | 252 |248 | 240 |224 | 192 | 128 | 0 );;
> +					*) echo "Error: $BR2_SIMPLE_NETWORK_IPV4_NETMASK is not a correct NETMASK" 1>&2; exit 1 ;;
> +				esac
> +			done

IFS="$OLDIFS"

> +		fi
> +	fi
> +}
> +
> +do_generate_interfaces ()
> +{

==START
> +	if [ "$BR2_PACKAGE_SYSTEMD_NETWORKD" ] ; then
> +		echo
> +		return
> +	fi
==END

Can be dropped, because you already check BR2_PACKAGE_SYSTEMD_NETWORKD
before calling do_generate_interfaces().

> +	echo "# interface file auto-generated by buildroot"
> +	echo
> +	echo "auto lo"
> +	echo "iface lo inet loopback"
> +	echo
> +
> +	if [ -z "$BR2_SIMPLE_NETWORK_NONE" ] ; then
> +		echo "auto $BR2_SIMPLE_NETWORK_NAME"
> +		if [ "$BR2_SIMPLE_NETWORK_IPV4_DHCP" ] ; then
> +			echo "iface $BR2_SIMPLE_NETWORK_NAME inet dhcp"
> +		elif [ "$BR2_SIMPLE_NETWORK_IPV4_MANUAL" ] ; then
> +			echo "iface $BR2_SIMPLE_NETWORK_NAME inet static"
> +			echo "	address $BR2_SIMPLE_NETWORK_IPV4_ADDRESS"
> +			echo "	netmask $BR2_SIMPLE_NETWORK_IPV4_NETMASK"
> +
> +			if [ "$BR2_SIMPLE_NETWORK_IPV4_BROADCAST" ] ; then
> +				echo "	broadcast $BR2_SIMPLE_NETWORK_IPV4_BROADCAST"
> +			fi
> +			if [ "$BR2_SIMPLE_NETWORK_IPV4_GATEWAY" ] ; then
> +				echo "	gateway $BR2_SIMPLE_NETWORK_IPV4_GATEWAY"
> +			fi
> +		fi
> +	fi
> +}
> +
> +do_generate_network_service ()
> +{
> +	if [ "$BR2_SIMPLE_NETWORK_NONE" ] ; then
> +		return
> +	fi
> +	echo "[Match]"
> +	echo "Name=$BR2_SIMPLE_NETWORK_NAME"
> +	echo

==START
> +	if [ $BR2_SIMPLE_NETWORK_IPV4_DHCP ] ; then
> +		echo "[Network]"
> +		echo "DHCP=v4"
> +	elif [ $BR2_SIMPLE_NETWORK_IPV4_MANUAL ] ; then
> +		nbits=0
> +		IFS=.
> +		for dec in $BR2_SIMPLE_NETWORK_IPV4_NETMASK ; do
> +			case $dec in
> +				255) let nbits+=8;;
> +				254) let nbits+=7;;
> +				252) let nbits+=6;;
> +				248) let nbits+=5;;
> +				240) let nbits+=4;;
> +				224) let nbits+=3;;
> +				192) let nbits+=2;;
> +				128) let nbits+=1;;
> +				0);;
> +			esac
> +		done
> +
> +		if [ "$BR2_SIMPLE_NETWORK_IPV4_ADDRESS" != "0.0.0.0" ] ; then
> +			if [ "$BR2_SIMPLE_NETWORK_IPV4_GATEWAY" ] ; then
> +				echo "[Network]"
> +				echo "Gateway=$BR2_SIMPLE_NETWORK_IPV4_GATEWAY"
> +				echo "Description=buildroot-configured interface"
> +				echo
> +			fi
> +			echo "[Address]"
> +			echo "Address=$BR2_SIMPLE_NETWORK_IPV4_ADDRESS/$nbits"
> +			if [ "$BR2_SIMPLE_NETWORK_IPV4_BROADCAST" ] ; then
> +				echo "Broadcast=$BR2_SIMPLE_NETWORK_IPV4_BROADCAST"
> +			fi
> +		fi
> +	fi
==END

What happens here is that "Description=" is only printed if a gateway is configured,
plus you can optimize the control flow a bit:


echo "[Network]"
echo "Description=buildroot-configured interface"

if [ $BR2_SIMPLE_NETWORK_IPV4_DHCP ] ; then
	echo "DHCP=v4"
elif \
	[ $BR2_SIMPLE_NETWORK_IPV4_MANUAL ] && \
	[ "$BR2_SIMPLE_NETWORK_IPV4_ADDRESS" != "0.0.0.0" ]
then
	OLDIFS="$IFS"; IFS=.            ## save IFS
	for ... case ... esac ... done  ## nbits
	IFS="$OLDIFS"                   ## restore IFS

	if [ "$BR2_SIMPLE_NETWORK_IPV4_GATEWAY" ]; then
		echo "Gateway=$BR2_SIMPLE_NETWORK_IPV4_GATEWAY"
	fi
	echo
	echo "[Address]"
	echo "Address=$BR2_SIMPLE_NETWORK_IPV4_ADDRESS/$nbits"
	if [ "$BR2_SIMPLE_NETWORK_IPV4_BROADCAST" ] ; then
		echo "Broadcast=$BR2_SIMPLE_NETWORK_IPV4_BROADCAST"
	fi
fi


> +}
> +
> +check_configuration
> +mkdir -p $TARGET_DIR/etc/network/

Need an "mkdir -p $TARGET_DIR/etc/systemd/network" here.
However, this would also create it for non-systemd systems, which is useless,
so rather remove the systemd file if it exists:

rm -f -- $TARGET_DIR/etc/systemd/network/80-buildroot.network


> +if [ "$BR2_PACKAGE_SYSTEMD_NETWORKD" ] ; then

and create the directory here:

	mkdir -p $TARGET_DIR/etc/systemd/network

> +	echo > $TARGET_DIR/etc/network/interfaces
> +	do_generate_network_service > $TARGET_DIR/etc/systemd/network/80-buildroot.network
> +else
> +	do_generate_interfaces > $TARGET_DIR/etc/network/interfaces

and drop this echo:

> +	echo > $TARGET_DIR/etc/systemd/network/80-buildroot.network

> +fi
> diff --git a/system/Config.in b/system/Config.in
> index 2465f79..3683edf 100644
> --- a/system/Config.in
[snip]


-- 
Andr?