Unable to build ovpn-dco kernel module Centos Stream 9

[vasilko]

Good day,
last few days I want to build kernel module ovpn-dco for my OpenVPN server.
I have no success with native package (dnf install kmod-ovpn-dco) version 0.2.20240619.
Now, I am trying to build it by hand and built against more kernels and with no success.
Tried kernels: 5.14.0-536.el9.x86_64, 5.14.0-539.el9.x86_64, 5.14.0-542.el9.x86_64, 5.14.0-547.el9.x86_64.
When I try build (make command), I got error:

make KERNEL_SRC=/usr/src/kernels/5.14.0-536.el9.x86_64/
/root/ovpn-dco/gen-compat-autoconf.sh /root/ovpn-dco/compat-autoconf.h
make -C /usr/src/kernels/5.14.0-536.el9.x86_64/ M=/root/ovpn-dco PWD=/root/ovpn-dco REVISION=0.2.20241216 CONFIG_OVPN_DCO_V2=m INSTALL_MOD_DIR=updates/ modules
make[1]: Entering directory '/usr/src/kernels/5.14.0-536.el9.x86_64'
CC [M] /root/ovpn-dco/drivers/net/ovpn-dco/main.o
In file included from :
./include/linux/skbuff.h: In function ‘skb_needs_linearize’:
/root/ovpn-dco/linux-compat.h:66:37: error: ‘NETIF_F_LLTX’ undeclared (first use in this function); did you mean ‘NETIF_F_LRO’?
66 | #define NETIF_F_SG (__NETIF_F(SG) | NETIF_F_LLTX)
| ^~~~~~~~~~~~
./include/linux/skbuff.h:4033:60: note: in expansion of macro ‘NETIF_F_SG’
4033 | (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
| ^~~~~~~~~~
/root/ovpn-dco/linux-compat.h:66:37: note: each undeclared identifier is reported only once for each function it appears in
66 | #define NETIF_F_SG (__NETIF_F(SG) | NETIF_F_LLTX)
| ^~~~~~~~~~~~
./include/linux/skbuff.h:4033:60: note: in expansion of macro ‘NETIF_F_SG’
4033 | (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
| ^~~~~~~~~~
In file included from ./include/net/sock.h:46,
from ./include/linux/tcp.h:19,
from ./include/linux/ipv6.h:112,
from /root/ovpn-dco/drivers/net/ovpn-dco/main.h:14,
from /root/ovpn-dco/drivers/net/ovpn-dco/main.c:10:
./include/linux/netdevice.h: At top level:
./include/linux/netdevice.h:2379:14: error: duplicate member ‘needs_free_netdev’
2379 | bool needs_free_netdev;
| ^~~~~~~~~~~~~~~~~
In file included from :
./include/linux/if_vlan.h: In function ‘vlan_features_check’:
/root/ovpn-dco/linux-compat.h:66:37: error: ‘NETIF_F_LLTX’ undeclared (first use in this function); did you mean ‘NETIF_F_LRO’?
66 | #define NETIF_F_SG (__NETIF_F(SG) | NETIF_F_LLTX)
| ^~~~~~~~~~~~
./include/linux/if_vlan.h:770:29: note: in expansion of macro ‘NETIF_F_SG’
770 | features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
| ^~~~~~~~~~
/root/ovpn-dco/drivers/net/ovpn-dco/main.c: In function ‘ovpn_setup’:
/root/ovpn-dco/linux-compat.h:66:37: error: ‘NETIF_F_LLTX’ undeclared (first use in this function); did you mean ‘NETIF_F_LRO’?
66 | #define NETIF_F_SG (__NETIF_F(SG) | NETIF_F_LLTX)
| ^~~~~~~~~~~~
/root/ovpn-dco/drivers/net/ovpn-dco/main.c:130:34: note: in expansion of macro ‘NETIF_F_SG’
130 | netdev_features_t feat = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM |
| ^~~~~~~~~~
make[3]: *** [scripts/Makefile.build:249: /root/ovpn-dco/drivers/net/ovpn-dco/main.o] Error 1
make[2]: *** [scripts/Makefile.build:478: /root/ovpn-dco/drivers/net/ovpn-dco] Error 2
make[1]: *** [Makefile:1942: /root/ovpn-dco] Error 2
make[1]: Leaving directory '/usr/src/kernels/5.14.0-536.el9.x86_64'
make: *** [Makefile:51: all] Error 2

Can anobody help me with this?
Thank for answer.

[ordex]

Again, it's RedHat backporting new features to older kernels and thus breaking all kind of version checks.
This needs to be explicitly fixed.

[vasilko]

Oooh, I find my old comment about similar problem.
Thank you for answer! and sorry for this.
I will migrate to Centos Stream 10, there it is OK.
Have a nice day.