[openib-general] RFC: move SDP from AF_INET_SDP to IPPROTO_SDP

[Michael S. Tsirkin]

Hi!
Would it make sense to move SDP from using a separate address family to
a separate protocol under AF_INET and AF_INET6?
Something like IPPROTO_SDP?

The main advantages are
- IPv6 support will come more naturally and without further extending
  to a yet another address family
- We could use a protocol number > 64K (e.g. 70000) to avoid conflicting
  with any IP based protocol.
  There are much more free protocol numbers that free family numbers
  (which only go up to 32 in linux for now).
- I could reuse more code for creating connections from af_inet.c

I also have a hunch this might make getaddrinfo work better on sdp but I'm not
sure.

Comments? Are there disadvantages to this approach that someone can see?

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies