From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 23 Sep 2006 22:03:44 +0000 (+0000)
Subject: add some notes about the network scripts
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8312ad091cad466e013de9056afeffcf445c4906;p=openwrt%2Fstaging%2Frmilecki.git

add some notes about the network scripts

SVN-Revision: 4848
---

diff --git a/openwrt/docs/network-scripts.txt b/openwrt/docs/network-scripts.txt
new file mode 100644
index 00000000000..30087cfcee7
--- /dev/null
+++ b/openwrt/docs/network-scripts.txt
@@ -0,0 +1,52 @@
+	Structure of the network scripts in buildroot-ng
+
+
+1) Usage
+
+To be able to access the network functions, you need to include
+the necessary shell scripts by running:
+
+. /etc/functions.sh      # common functions
+include network          # include /lib/network/*.sh
+scan_interfaces          # read and parse the network config
+
+Some protocols, such as PPP might change the configured interface names
+at run time (e.g. eth0 => ppp0 for PPPoE). That's why you have to run
+scan_interfaces instead of reading the values from the config directly.
+After running scan_interfaces, the 'ifname' option will always contain
+the effective interface name (which is used for IP traffic) and if the
+physical device name differs from it, it will be stored in the 'device'
+option.
+That means that running 'config_get lan ifname' after scan_interfaces
+might not return the same result as running it before.
+
+After running scan_interfaces, the following functions are available:
+
+- find_config <interface> looks for a network configuration that includes
+  the specified network interface.
+
+- setup_interface <interface> [<config>] [<protocol>] will set up the
+  specified interface, optionally overriding the network configuration
+  name or the protocol that it uses.
+
+
+
+2) Writing protocol handlers
+
+You can add custom protocol handlers by adding shell scripts to
+/lib/network. They provide the following two shell functions:
+
+scan_<protocolname>() {
+	local config="$1"
+	# change the interface names if necessary
+}
+
+setup_interface_<protocolname>() {
+	local interface="$1"
+	local config="$2"
+	# set up the interface
+}
+
+scan_<protocolname> is optional and only necessary if your protocol
+uses a custom device, e.g. a tunnel or a PPP device.
+