OpenVPN-devel package for OpenWrt

OpenWrt is a very small Linux distribution for routers, initially the Cisco/Linksys? "WRT 54 GL", thus the name.

OpenWrt (stable) comes with an OpenVPN package based on the mainstream 2.1 release (as of 2010/06/27).

Update: 2014/02/23: Latest unstable (trunk) release of OpenWRT includes OpenVPN 2.3.2. IPv6 support is included. The below documentation is obsolete because there is no openvpn-devel package anymore.

If you want IPv6 support or any of the other features in the development tree, you have to build your own package, based on the openvpn-devel sources. Given that OpenWrt packages are not for standard i386/amd64 CPUs but usually some sort of MIPS system, you need a cross-compilation environment and special tools - but that's all already provided by the OpenWrt folks, so you just need to add a few bits to add your own package.

Update: 2010/08/03: there is an openvpn-devel package in the official OpenWrt package tree. So far it's not available as binary, so this document explains how to checkout the source tree and build from there.

how to build

  1. get the OpenWrt source tree from OpenWrt SVN (do this on a Linux system, as a normal user, no root permissions needed) - this is for OpenWrt 10.03 ("backfire"), adapt for other branches as needed:
    svn co svn://
  1. get the OpenWrt package tree from SVN and "install" (put all the symlinks where they are needed):
    cd backfire
    ./scripts/feeds update
    ./scripts/feeds install -a
  1. check that the openvpn-devel version that is included is the one that you want to build
backfire$ cd package/feeds/packages/openvpn-devel
backfire/package/feeds/packages/openvpn-devel$ grep ^PKG_VERSION Makefile

this number is the "week 26 of the year 2010", which is the tarball that we're building from. If you change that, do not forget to update the PKG_MD5SUM line in the Makefile, otherwise building will fail (checksum error). If you're lazy, just remove the PKG_MD5SUM line (this will disable checksumming the downloaded tar archive).

  1. go back to the top level directory and run the config scripts:
    backfire/package/feeds/packages/openvpn-devel$ cd ../../../..
    backfire$ make defconfig
    backfire$ make menuconfig
  • in the "Target System" menu, select the correct OpenWrt version for your hardware (check the pages for your router type, one example would be "TP-Link TL1043ND -> ar71xx -> Atheros AR71xx/AR7240/AR913x"). Since we do not want to build a bootable OpenWrt itself, just an OpenWrt package, it's not important to get this 100% right - having the right CPU version (ar71xx in this example) is what counts. The output of "opkg install $somepackage" on your OpenWrt installation will tell you the architecture type, in the .ipk file name.
  • go to "Network" -> "VPN" and check <M> "openvpn-devel" (prerequisites like lzo and zlib will be autoselected)
  • then "exit" -> "exit" -> "exit" -> "save config -> yes"
  1. run "make" and wait... - this will take a long time, building the C compiler (for cross-building to MIPS cpu) and the target system's C library etc. first.
backfire$ make
 make[1] world
 make[2] target/compile
 make[3] -C target/linux compile
 make[3] -C feeds/packages/libs/lzo compile
 make[3] -C package/iptables compile
 make[3] -C package/opkg compile
 make[3] -C package/firewall compile
 make[3] -C package/crda compile
 make[3] -C package/hostapd compile
 make[3] -C feeds/packages/net/openvpn-devel compile   <<<<< :-)
 make[3] package/preconfig
 make[2] target/install
 make[3] -C target/linux install
 make[2] package/index
  1. now you have an openvpn-devel package in ./bin/ar71xx/packages/
backfire$ ls -l bin/ar71xx/packages/
-rw-r--r-- 1 gert users 182075 27. Jun 16:03 openvpn-devel_201026-1_ar71xx.ipk

Installing the package

Login to your OpenWrt router, ftp/wget the package to /tmp, and run "opkg install":

root@OpenWrt:/tmp# opkg update
Updated list of available packages in /var/opkg-lists/packages.
root@openwrt:/tmp# wget http:<myserver>/openvpn-devel_201026-1_ar71xx.ipk
root@openwrt:/tmp$ opkg install openvpn*ipk
Installing openvpn_devel (201026-1) to root...
Installing kmod-tun ( to root...
Installing kmod-ipv6 ( to root...
Installing libopenssl (0.9.8m-3) to root...
Installing zlib (1.2.3-5) to root...
Installing liblzo (2.03-3) to root...
Installing ip (2.6.29-1-2) to root...
Configuring ip.
Configuring kmod-tun.
Configuring kmod-ipv6.
Configuring zlib.
Configuring libopenssl.
Configuring liblzo.
Configuring openvpn-devel.
root@OpenWrt:/tmp# openvpn |head -2
OpenVPN testing-f0b02a9dfab6 mips-openwrt-linux [SSL] [LZO2] [MH] [PF_INET6] [IPv6 payload 20100307-1] built on Jun 27 2010

Last modified 8 years ago Last modified on 02/23/14 19:27:37