Use BSD's upstream if_ether.h

[lamaral]

Hello,

While trying to build lldpd on FreeBSD 14-CURRENT, I ran into an issue where a struct was being redefined:

--- liblldpd_la-interfaces-bsd.lo ---
In file included from interfaces-bsd.c:33:
In file included from /usr/include/net/if_bridgevar.h:84:
/usr/include/net/ethernet.h:62:8: fatal error: redefinition of 'ether_header'
struct ether_header {
       ^
../../include/netinet/if_ether.h:72:8: note: previous definition is here
struct  ether_header {
        ^
1 error generated.
*** [liblldpd_la-interfaces-bsd.lo] Error code 1

The build was working on FreeBSD 13.0-RELEASE, but started failing on CURRENT.

I was able to pinpoint it to FreeBSD including net/ethernet.h on this commit.

I included sys/socket.h in order to have the sockaddr struct defined and moved netinet/if_ether.h after netinet/in.h in order to have in_addr defined before it's used in if_ether.h.

With these changes, I was able to build it on FreeBSD 13.0 as well as on CURRENT. Let me know what you think.

Thanks,
Luiz.

[vincentbernat]

Unfortunately, this header is also used by other platforms. All the headers are a bit of a mess. They were definitely needed for older versions of Linux, but maybe this is not the case anymore. I am trying to add CI for BSD in #504. After that, I'll try to check if all these headers are still needed on Linux and MacOS. I don't think the BSD ever needed them.

Alternatively, the headers could be included only on Linux and MacOS.

[vincentbernat]

So, I was able to remove non-OS specific headers. I have applied your patch and made a few tweaks. It works on OpenBSD and FreeBSD, as well as old Linux distros.

[lamaral]

Awesome :)
Thanks for the fix