Coverity noted that 4 out of 5 calls to virNetClientStreamRaiseError
checked the return value. This case expects a particular value, so
warn if our expectations went wrong due to some bug elsewhere.
* src/rpc/virnetclient.c (virNetClientCallDispatchStream): Warn on
unexpected scenario.
Detected by Coverity. Both are instances of bad things happening
if pipe2 fails; the virNetClientNew failure could free garbage,
and virNetSocketNewConnectCommand could close random fds.
Note: POSIX doesn't guarantee the contents of fd[0] and fd[1]
after pipe failure: http://austingroupbugs.net/view.php?id=467
We may need to introduce a virPipe2 wrapper that guarantees
that on pipe failure, the fds are explicitly set to -1, rather
than our current state of assuming the fds are unchanged from
their value prior to the failed pipe call.
* src/rpc/virnetclient.c (virNetClientNew): Initialize variable.
* src/rpc/virnetsocket.c (virNetSocketNewConnectCommand):
Likewise.
When the remote client receives end of file on the stream
it never invokes the stream callback. Applications relying
on async event driven I/O will thus never see the EOF
condition on the stream
* src/rpc/virnetclient.c, src/rpc/virnetclientstream.c:
Ensure EOF is dispatched
If a streams error is raised, virNetClientIOEventLoop
returns 0, but an error is set. Check for this and
propagate it if present
* src/rpc/virnetclient.c: Propagate streams error
To facilitate creation of new clients using XDR RPC services,
pull alot of the remote driver code into a set of reusable
objects.
- virNetClient: Encapsulates a socket connection to a
remote RPC server. Handles all the network I/O for
reading/writing RPC messages. Delegates RPC encoding
and decoding to the registered programs
- virNetClientProgram: Handles processing and dispatch
of RPC messages for a single RPC (program,version).
A program can register to receive async events
from a client
- virNetClientStream: Handles generic I/O stream
integration to RPC layer
Each new client program now merely needs to define the list of
RPC procedures & events it wants and their handlers. It does
not need to deal with any of the network I/O functionality at
all.
