SRV lookup support (Bugzilla 2217)

[Mara Sophie Grosch]

Hi there,

I'm new on this list and on the contribution side to this project, so
please be gentle.

I want to tackle SRV lookup support in OpenSSH client, especially for
the use case of non-standard ports on the server - which is a part of
Bugzilla 2217 [1].

For that, I made a first implementation, hooking into `resolve_host` in
ssh.c, calling a new `resolve_srv` if no port is given on the command
line or config. Full patch is available as pull request on github[2]. I
figured, discussing this here is probably better, since it's not only a
change for non-OpenBSD OpenSSH.

I would love comments about my approach and about changes that would be
required for this to be merged - or discussion about how to better
approach this. Only invested an evening so far, so starting a new
wouldn't be a big problem if results are a lot better :)

Thanks and best regards
Mara Sophie Grosch


[1] https://bugzilla.mindrot.org/show_bug.cgi?id=2217
[2] https://github.com/openssh/openssh-portable/pull/228