Plumber both posts a service to /srv and sets a $plumbsrv environment
variable. Our libplumb no longer uses $plumbsrv and nothing else
does. It's a silly hack; rc doesn't update /env immediately, and
scripts, which for instance set up subrios, cannot rely on it to
clean up the plumber at the end.
Instead, add the option to specify a srvname, actually check for some
common errors and print a usage string.
Thanks to Ori for input and a preliminary patch.
version(5) says:
If the server does not understand the client's version
string, it should respond with an Rversion message (not
Rerror) with the version string the 7 characters
``unknown''.
Pre-lib9p file servers -- all except cwfs(4) -- do return Rerror.
lib9p(2) follows the above spec, although ignoring the next part
concerning comparison after period-stripping. It assumes an
Fcall.version starting with "9P" is correctly formed and returns
the only supported version of the protocol, which seems alright.
This patch brings pre-lib9p servers in accordance with the spec.
The mount() and bind() syscalls return -1 on error,
and the mountid sequence number on success.
The manpage states that the mountid sequence number
is a positive integer, but the kernels implementation
currently uses a unsigned 32-bit integer and does not
guarantee that the mountid will not become negative.
Most code just cares about the error, so test for
the -1 error value only.
when we get eof, stop the loop immidiately and do not
rely on the read to eventually return an error.
when convM2S() fails to decode the message, error out
and stop the loop. there is no point in continuing.
