[DCO] [MIPS] [BUG] OpenVPN 2.7.0 server fails to load DCO

Tried to use OpenVPN 2.7.0 with latest master branch of ovpn-dco on **Big Endian** MIPS router. Faced with error: ``` Cannot find ovpn_dco netlink component: Object not found Note: Kernel support for ovpn-dco missing, disabling data channel offload. ``` Does it allowed to use master branch of ovpn-dco together with OpenVPN 2.7.0 ? Found that my previous version (which works well and does not fail) 2.6.14 has #define OVPN_NL_NAME "ovpn-dco-v2" in **_ovpn_dco_linux.h_** but new version 2.7.0 has changed definition name and value: #define OVPN_FAMILY_NAME "ovpn" **_ovpn_dco_linux.h_** After tried to change the value in OpenVPN 2.7 sources (**_ovpn_dco_linux.h_**) from ovpn to ovpn-dco-v2 got another error: ``` 2026-02-23 17:17:06 us=318510 ovpn_dco_register 2026-02-23 17:17:06 us=319640 ovpn-dco: received netlink message type=16 cmd=1 flags=0000 2026-02-23 17:17:06 us=320038 ovpn-dco: received CTRLID message 2026-02-23 17:17:06 us=320714 open_tun_dco: ovpn-udp 2026-02-23 17:17:06 us=321109 net_iface_new: add ovpn-udp type ovpn-dco-v2 2026-02-23 17:17:06 us=402318 sitnl_send: checking for received messages 2026-02-23 17:17:06 us=402930 sitnl_send: rtnl: received 88 bytes 2026-02-23 17:17:06 us=403324 sitnl_send: rtnl: generic error (-122): Not supported 2026-02-23 17:17:06 us=403855 Cannot create DCO interface ovpn-udp: -122 2026-02-23 17:17:06 us=404257 Cannot open DCO device ovpn-udp: Not supported (-122): No such file or directory (errno=2) 2026-02-23 17:17:06 us=404560 Exiting due to fatal error ``` That perfectly WORKS with OpenVPN 2.6.14: ``` #openvpn --version OpenVPN 2.6.14 mips-openwrt-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [MH/PKTINFO] [AEAD] [DCO] library versions: OpenSSL 3.6.1 27 Jan 2026, LZO 2.10 DCO version: N/A Originally developed by James Yonan Copyright (C) 2002-2024 OpenVPN Inc <sales@openvpn.net> root@openwrt:~# ip link show | grep ovpn 21: ovpn-tcp: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1400 qdisc noqueue state UNKNOWN qlen 2000 22: ovpn-udp: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1420 qdisc noqueue state UNKNOWN qlen 2000 2026-02-23 17:18:06 us=6517 sitnl_send: checking for received messages 2026-02-23 17:18:06 us=6972 sitnl_send: rtnl: received 36 bytes 2026-02-23 17:18:06 us=7461 net_iface_up: set ovpn-udp up 2026-02-23 17:18:06 us=7998 sitnl_send: checking for received messages 2026-02-23 17:18:06 us=8442 sitnl_send: rtnl: received 36 bytes ``` ``` Linux openwrt 6.6.119 #0 Wed Dec 17 21:08:22 2025 mips GNU/Linux DISTRIB_ID='OpenWrt' DISTRIB_RELEASE='24.10.5' DISTRIB_REVISION='r29087-d9c5716d1d' DISTRIB_TARGET='ath79/generic' DISTRIB_ARCH='mips_24kc' DISTRIB_DESCRIPTION='OpenWrt 24.10.5 r29087-d9c5716d1d' DISTRIB_TAINTS='' root@openwrt:/tmp# cat /etc/openwrt_version r29087-d9c5716d1d ovpn-dco installed from master (2026-02-23): git ls-remote https://github.com/OpenVPN/ovpn-dco.git master | cut -f1 fd3dac4b07933d39e0b2c2fc7e2f4fb8ae79532c OpenVPN version: 2.7.0 2f0e10eb272be61e8fb25fe1cfa20875ff30ac857ef1418000c02290bd6dfa45 #openvpn --version OpenVPN 2.7.0 mips-openwrt-linux-gnu [SSL (OpenSSL)] [EPOLL] [MH/PKTINFO] [AEAD] [DCO] library versions: OpenSSL 3.6.1 27 Jan 2026 DCO version: N/A Originally developed by James Yonan Copyright (C) 2002-2026 OpenVPN Inc <sales@openvpn.net> Installed: kmod-cryptodev - 6.6.119.1.14-r1 kmod-ovpn-dco-v2 - 6.6.119.0.2.20260223-r1 libcap-ng - 0.8.5-r1 libcap-ng-bin - 0.8.5-r1 libnl-cli200 - 3.12.0-r1 libnl-core200 - 3.12.0-r1 libnl-genl200 - 3.12.0-r1 libnl-nf200 - 3.12.0-r1 libnl-route200 - 3.12.0-r1 libnl-tiny1 - 2025.03.19~c0df580a-r1 libnl200 - 3.12.0-r1 libopenssl-afalg - 3.6.1-r1 libopenssl-conf - 3.6.1-r1 libopenssl-devcrypto - 3.6.1-r1 libopenssl-legacy - 3.6.1-r1 libopenssl3 - 3.0.19-r1 openvpn-easy-rsa - 3.1.3-r1 openvpn-openssl - 2.7.0-r2 root@openwrt:~# modinfo ovpn-dco-v2 filename: /lib/modules/6.6.119/ovpn-dco-v2.ko alias: net-pf-16-proto-16-family-ovpn-dco-v2 alias: rtnl-link-ovpn-dco license: GPL depends: ip6_udp_tunnel,udp_tunnel name: ovpn_dco_v2 vermagic: 6.6.119 mod_unload MIPS32_R2 32BIT root@openwrt:~# logread | grep -i dco Mon Feb 23 16:08:36 2026 kern.info kernel: [ 21.494853] OpenVPN data channel offload (ovpn-dco) 2.0.0 -- (C) 2020- OpenVPN, Inc. root@openwrt:~# lsmod | grep ovpn ip6_udp_tunnel 12288 1 ovpn_dco_v2 ovpn_dco_v2 53248 0 udp_tunnel 20480 1 ovpn_dco_v2 root@openwrt:~# opkg list-installed | grep kmod-ovpn-dco kmod-ovpn-dco-v2 - 6.6.119.0.2.20260223-r1 ```