The various protocols were made static since there was no point in
exporting them in the past. Nowadays with QUIC relying on UDP we'll
significantly benefit from UDP being exported and more generally from
being able to declare some functions as being the same as other
protocols'.
In an ideal world it should not be these protocols which should be
exported, but the intermediary levels:
- socket layer (sock.c only right now), already exported as functions
but nothing structured at the moment ;
- family layer (sock_inet, sock_unix, sockpair etc): already structured
and exported
- binding layer (the part that relies on the receiver): currently fused
within the protocol
- connectiong layer (the part that manipulates connections): currently
fused within the protocol
- protocol (connection's control): shouldn't need to be exposed
ultimately once the elements above are in an easily sharable way.
We don't need to specify the handler anymore since it's set in the
receiver. Let's remove this argument from the function and clean up
the remains of code that were still setting it.
We need to specially handle protocol families which regroup common
functions used for a given address family. These functions include
bind(), addrcmp(), get_src() and get_dst() for now. Some fields are
also added about the address family, socket domain (protocol family
passed to the socket() syscall), and address length.
These protocol families are referenced from the protocols but not yet
used.
Note that for now we don't have a sockpair.c file to host that unusual
family, so the new function was placed directly into proto_sockpair.c.
It's no big deal given that this family is currently not shared with
multiple protocols.
The function does almost nothing but setting up the receiver. This is
normal as the socket the FDs are passed onto are supposed to have been
already created somewhere else, and the only usable identifier for such
a socket pair is the receiving FD itself.
The function was assigned to sockpair's ->bind() and is not used yet.
