Hi all, I hope this finds you well.
In commit b977dd1ea5fbc2df3f1279330be4d089322eb2cf [1], the check
if (hdr->nlmsg_len < sizeof(struct nlmsghdr) + sizeof(struct
ifaddrmsg))
return (EBADMSG);
in `sys/compat/linux/linux_netlink.c:97` was added and caused glibc's
getaddrinfo(3) to break. This, as one might think, causes quite a few
programs in the linuxulator to stop work. After looking into it, glibc
is indeed not sending what we're expecting. Not only are they not
including the space of the header, but they're also using the seemingly
depreciated (i.e no documentation [i could find] speaking of it)
`rtgenmsg` format. [2] While indeed we also have this in our codebase
`sys/netlink/route/route.h:363`, it's used nowhere except in
`crypto/heimdal/lib/roken/getifaddrs.c:275`; however, even in that code,
they make sure to include the space of the header with the
`NLMSG_LENGTH` macro. Obliviously, please take this with a large grain
of salt as I'm quite inexperienced. That being said, I believe our best
bet would be to contact upstream, and in the meantime, implement this
functionality. On the latter half, I would be more than happy to do said
implementing, all I would need are some pointers to relevant
documentation.
Cheers!
[1]
https://cgit.freebsd.org/src/commit?id=b977dd1ea5fbc2df3f1279330be4d089322eb2cf
[2]
https://elixir.bootlin.com/glibc/latest/source/sysdeps/unix/sysv/linux/check_pf.c#L92
