This is a forward-port of release/3.5 commit 566f4678
* Add generic direction enum for negotiation setup.
* Rename a rather long wrapper function to a shorter one consistent with
what it does.
* Rework context setup function.
* Don't check for handshake state before beginning handshaking.
The old backend began a handshake and then stepped into the callback
function if it was interrupted; the current one just jumps right into
it, so there is no need to check if it has previously succeeded,
because it hasn't been attempted yet.
* Add missing errno assignment to one of the handshake wrappers.
* Don't bother checking if SSL_P(F) is NULL when we already checked if
F->ssl is NULL -- this should be impossible.
* Don't bother checking if SSL_C(F) is NULL -- this was a no-op.
* Change the socket send and recv functions to not peer into a foreign
ratbox structure -- use the correct function to get the socket fd.
* Rewrap some lines and function arguments.
Other backends will be brought into line with this backend soon.
This will enable easier maintenance of the backends, by reducing the
diffs between them, which should make different behaviour easier to
spot.
c4acd427ac