NETCONF support for OpenWRT the OpenCPE way

The OpenCPE projects aims to provide NETCONF support in a non-intrusive way. It therefore does not replace OpenWRT uci framework, but build on top it.

NETCONF support consists of tree main parts:

• NETCONF model and data storage daemon (mand)
• NETCONF protocol frontend (freenetconfd)
• NETCONF to UCI bridge (mand-cfg)

For the Cisco Linksys EA4500 an additional component provides firmware upgrade support.

Building NETCONF support

Software needed on the Host system

1. xsltproc: should be available as package on all major linux distributions
2. pyang: download and install it with python setup.py install

Install Feed

• Add OpenCPE package feed to feeds.conf.default, like:

src-git opencpe https://github.com/opencpe/openwrt-packages.git

• Disable OpenWrt's management feed in feeds.conf.default, like:

# disable openwrt management feed
#src-git management https://github.com/openwrt-management/packages.git

Install all Packages

• Install all OpenCPE Packages:

% ./scripts/feeds install -a -p opencpe

opencpe is the alias in feeds.conf.default.

• libexpat is needed as a dependency. Installed it from OpenWrt's packages feed:

% ./scripts/feeds install -p packages libexpat

Configure OpenWrt Buildroot

• To select all packages from OpenCPE, run:

    % make menuconfig

• Now select all packages, namely:
  1. Utilities -> mand
  2. Utilities -> mand-cfgd
  3. Utilities -> freenetconfd
• same of this packages maybe already selected.

Build OpenWrt

Build OpenWrt as usual, like:

% make

Using NETCONF support

Setup and operation of a NETCONF server is out of the scope of this guide. It is expected that you have a running NETCONF server that supports the OpenCPE YANG models

If your OpenWRT was installed without the NETCONF packages, install and enable freenetconfd, mand and mand-cfg:

opkg install freenetconfd mand mand-cfg
/etc/init.d/freenetconfd enable
/etc/init.d/mand enable
/etc/init.d/mand-cfg enable

Adjust /etc/config/freenetconfd to point to the correct ssh-keys to permit your NETCONF server to connect to the device. Restart freenetconfd after changing the config.

Now try to connect to the device from the NETCONF server. The /system-state subtree should give you the OpenWRT version and release information.

Interfaces on device other than the Cisco Linksys EA4500 in OpenCPE configuration

Physical interface informations need to be mapped to logical interfaces for NETCONF. This is done through the default config of mand in /etc/dm/dm.xml. The shiped default if preconfigured for the Cisco Linksys EA4500 in OpenCPE configuration.

Each device interface needs a /OpenCPE/interfaces and /OpenCPE/interfaces-state section in this files. The structure of those entries is defined by the OpenCPE YANG models.

Sample:

<interface instance='2'>
    <name>lan</name>
    <description>LAN Interface</description>
    <type>ethernetCsmacd</type>
    <enabled>true</enabled>
    <link-up-down-trap-enable>enabled</link-up-down-trap-enable>
    <ipv4>
        <enabled>true</enabled>
        <forwarding>false</forwarding>
        <mtu>1500</mtu>
        <address instance='1'>
            <ip>192.168.1.1</ip>
            <prefix-length>24</prefix-length>
        </address>
    </ipv4>
    <ipv6>
        <enabled>true</enabled>
        <forwarding>false</forwarding>
        <mtu>1500</mtu>
        <address instance='1'>
            <ip>1::1</ip>
            <prefix-length>64</prefix-length>
        </address>
        <dup-addr-detect-transmits>0</dup-addr-detect-transmits>
        <autoconf>
            <create-global-addresses>false</create-global-addresses>
            <create-temporary-addresses>false</create-temporary-addresses>
            <temporary-valid-lifetime>0</temporary-valid-lifetime>
            <temporary-preferred-lifetime>0</temporary-preferred-lifetime>
        </autoconf>
    </ipv6>
</interface>

and:

<interface instance="2">
    <name>eth0</name>
    <type>ethernetCsmacd</type>
    <if-index>2</if-index>
    <higher-layer-if instance='1'>
        <higher-layer-if>interfaces-state.interface.5</higher-layer-if>
    </higher-layer-if>
</interface>