Always passing 0 to reconnect_disconnected() means that it uses a generic
log message ("connection dropped"). By passing the error code, as done by
this commit, reconnect_disconnected() can log a more specific message.
Sometimes, when a user asks me to help debug a problem, it turns out that
an SSL connection was being made on a TCP port, or vice versa, or that an
OpenFlow connection was being made on a JSON-RPC port, or vice versa, and
so on. This commit adds log messages that diagnose this kind of problem,
e.g. "tcp:127.0.0.1:6633: received JSON-RPC data on OpenFlow channel".
The fatal-signal library notices and records fatal signals (e.g. SIGTERM)
and terminates the process on the next trip through poll_block(). But
some special utilities do not always invoke poll_block() promptly, e.g.
"ovs-ofctl monitor" does not call poll_block() as long as OpenFlow messages
are available. But these special cases seem like they are all likely to
call into functions that themselves block (those with "_block" in their
names). So make a new rule that such functions should always call
fatal_signal_run(), either directly or through poll_block(). This commit
implements and documents that rule.
Bug #2625.
This is unlikely to occur very often in practice, because s->stream
usually gets stuffed into s->rpc before long, but it is still a good idea
to fix it.
Some upcoming code wants to serialize JSON into a "struct ds" dynamic
string buffer, so expose an interface to do this.
This commit doesn't change much, but it renames some functions internal
to json.c to make the naming more consistent.
Also, make jsonrpc_log_msg() use this new function, since it is a more
straightforward way to do what it wants.
jsonrpc_session_connect() indirectly called reconnect_disconnected(), which
told the reconnect object that the connection had failed, before it told it
that the connection attempt had started. When the connection didn't
complete immediately, this caused the connection to time out immediately,
without any backoff.
Reported by Jeremy Stribling.
SSL, which will be added in an upcoming commit, requires some background
processing, which is best done in a "run" function in our architecture.
This commit adds stream_run() and stream_run_wait() and calls to them from
the places where they will be required.
