[Buildroot] [PATCH v5 1/1] set simple network setup via the system configuration submenu

Jérémy Rosen jeremy.rosen at openwide.fr
Tue Dec 9 08:48:44 UTC 2014


This patch allows the setup of simple /etc/network/interfaces (or
/etc/systemd/network/80-buildroot.network if networkd is enabled) via the
configuration menus instead of using an overlay

* supports disabling the interface
* supports manual ipv4 configuration
* supports dhcp configuration


Signed-off-by: Jérémy Rosen <jeremy.rosen at openwide.fr>
---

This patch is here to avoid having to do an overlay for the most common
cases (ipv4 with fixed IP or DHCP)

This is reduced to the bare minimum to cover the most common case. Anything
more complex can be done by using overlays instead.

I have not added the option to (de)activate persistant naming when networkd
is enabled because it logically belongs to the networkd package and not to
the simple network configuration
---
v5:
* remove use of "let" which is not supported by all shells
v4:
* correctly create /etc/systemd/networkd
* rework logic to simplify a bit
v3 :
* rename the script to a more generic name
* reorganized script to separate param verification from generation
* quoted params properly to protect against faulty params
* removed /etc/network/interfaces from skeleton
* reorganized options in configuration menu
* added networkd configuration support

v2 :
* moved to TARGET_FINALIZE
* removed support for lo. It should always be on.
* reworked default parameters
---
 support/scripts/generate-network-config.sh | 132 +++++++++++++++++++++++++++++
 system/Config.in                           |  60 +++++++++++++
 system/skeleton/etc/network/interfaces     |   4 -
 system/system.mk                           |   5 ++
 4 files changed, 197 insertions(+), 4 deletions(-)
 create mode 100755 support/scripts/generate-network-config.sh
 delete mode 100644 system/skeleton/etc/network/interfaces

diff --git a/support/scripts/generate-network-config.sh b/support/scripts/generate-network-config.sh
new file mode 100755
index 0000000..31156c4
--- /dev/null
+++ b/support/scripts/generate-network-config.sh
@@ -0,0 +1,132 @@
+#!/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 "$BR2_SIMPLE_NETWORK_IPV4_NETMASK" ] ; then
+				echo ERROR BR2_SIMPLE_NETWORK_IPV4_NETMASK not set 1>&2
+				exit 1
+			fi
+			OLDIFS="$IFS"; 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 ()
+{
+	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
+	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
+		nbits=0
+		OLDIFS="$IFS"; IFS=.
+		for dec in $BR2_SIMPLE_NETWORK_IPV4_NETMASK ; do
+			case $dec in
+				255) nbits = $((nbits+=8));;
+				254) nbits = $((nbits+=7));;
+				252) nbits = $((nbits+=6));;
+				248) nbits = $((nbits+=5));;
+				240) nbits = $((nbits+=4));;
+				224) nbits = $((nbits+=3));;
+				192) nbits = $((nbits+=2));;
+				128) nbits = $((nbits+=1));;
+			esac
+		done
+		IFS="$OLDIFS"
+
+		if [ "$BR2_SIMPLE_NETWORK_IPV4_GATEWAY" ] ; then
+			echo "Gateway=$BR2_SIMPLE_NETWORK_IPV4_GATEWAY"
+			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
+}
+
+check_configuration
+mkdir -p $TARGET_DIR/etc/network/
+rm -f -- $TARGET_DIR/etc/systemd/network/80-buildroot.network
+if [ "$BR2_PACKAGE_SYSTEMD_NETWORKD" ] ; then
+	echo > $TARGET_DIR/etc/network/interfaces
+	mkdir -p $TARGET_DIR/etc/systemd/network/
+	do_generate_network_service > $TARGET_DIR/etc/systemd/network/80-buildroot.network
+else
+	do_generate_interfaces > $TARGET_DIR/etc/network/interfaces
+fi
diff --git a/system/Config.in b/system/Config.in
index 39f27c7..46f2014 100644
--- a/system/Config.in
+++ b/system/Config.in
@@ -324,6 +324,66 @@ config BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW
 
 endif # BR2_ROOTFS_SKELETON_DEFAULT
 
+choice
+	prompt 'Simple network configuration'
+	default BR2_SIMPLE_NETWORK_NONE
+	help
+	  buildroot will create a simple network configuration for a network
+	  interface. This will generate the corresponding lines in
+	  /etc/network/interfaces which is used by ifupdown.
+
+	  The simple network configuration only supports a single network
+	  interface using a static or DHCP-allocated IPv4 address. If you
+	  need something more complicate, create your own configuration file
+	  in the BR2_ROOTFS_OVERLAY.
+
+config BR2_SIMPLE_NETWORK_NONE
+	bool "No configured network interface"
+	help
+	  Do not configure the network interface, only configure the
+	  loopback device
+
+config BR2_SIMPLE_NETWORK_IPV4_DHCP
+	bool "IPv4 with DHCP"
+	help
+	  Use DHCP to configure this interface using the IPv4 protocol
+
+config BR2_SIMPLE_NETWORK_IPV4_MANUAL
+	bool "IPv4 with static IP address"
+	help
+	  Configure IPv4 by specifying each parameter separately
+
+endchoice
+
+if !BR2_SIMPLE_NETWORK_NONE
+
+config BR2_SIMPLE_NETWORK_NAME
+	string "name of the physical network interface"
+	default "eth0"
+	help
+	  The name used to recognise the network interface as reported
+	  by the kernel
+
+if BR2_SIMPLE_NETWORK_IPV4_MANUAL
+config BR2_SIMPLE_NETWORK_IPV4_ADDRESS
+	string "IP Address of the network interface"
+	default "0.0.0.0"
+
+config BR2_SIMPLE_NETWORK_IPV4_NETMASK
+	string "Netmask of the network interface"
+	default "255.255.255.255"
+
+config BR2_SIMPLE_NETWORK_IPV4_BROADCAST
+	string "Broadcast Address of the network interface"
+
+config BR2_SIMPLE_NETWORK_IPV4_GATEWAY
+	string "Address of the gateway for the network interface"
+
+endif # BR2_SIMPLE_NETWORK_IPV4_MANUAL
+
+endif # !BR2_SIMPLE_NETWORK_NONE
+
+
 config BR2_TARGET_TZ_INFO
 	bool "Install timezone info"
 	# No timezone for musl; only for uClibc or (e)glibc.
diff --git a/system/skeleton/etc/network/interfaces b/system/skeleton/etc/network/interfaces
deleted file mode 100644
index 218b82c..0000000
--- a/system/skeleton/etc/network/interfaces
+++ /dev/null
@@ -1,4 +0,0 @@
-# Configure Loopback
-auto lo
-iface lo inet loopback
-
diff --git a/system/system.mk b/system/system.mk
index e4a3160..bb933f6 100644
--- a/system/system.mk
+++ b/system/system.mk
@@ -38,6 +38,11 @@ ifneq ($(TARGET_GENERIC_ROOT_PASSWD),)
 TARGETS += host-mkpasswd
 endif
 
+define SIMPLE_NETWORK
+	$(TOPDIR)/support/scripts/generate-network-config.sh $(TARGET_DIR)
+endef
+TARGET_FINALIZE_HOOKS += SIMPLE_NETWORK
+
 ifeq ($(BR2_ROOTFS_SKELETON_DEFAULT),y)
 
 define SYSTEM_ROOT_PASSWD
-- 
2.1.3



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