remote_driver: Implement VIR_STREAM_RECV_STOP_AT_HOLE

This is fairly trivial now that we have everything in place.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/remote/remote_driver.c

@@ -5652,7 +5652,7 @@ remoteStreamRecvFlags(virStreamPtr st,
     virNetClientStreamPtr privst = st->privateData;
     int rv;
 
-    virCheckFlags(0, -1);
+    virCheckFlags(VIR_STREAM_RECV_STOP_AT_HOLE, -1);
 
     if (virNetClientStreamRaiseError(privst))
         return -1;

src/rpc/virnetclientstream.c

@@ -468,7 +468,7 @@ int virNetClientStreamRecvPacket(virNetClientStreamPtr st,
     VIR_DEBUG("st=%p client=%p data=%p nbytes=%zu nonblock=%d flags=%x",
               st, client, data, nbytes, nonblock, flags);
 
-    virCheckFlags(0, -1);
+    virCheckFlags(VIR_STREAM_RECV_STOP_AT_HOLE, -1);
 
     virObjectLock(st);
 
@@ -532,6 +532,13 @@ int virNetClientStreamRecvPacket(virNetClientStreamPtr st,
         /* Pretend holeLength zeroes was read from stream. */
         size_t len = want;
 
+        /* Yes, pretend unless we are asked not to. */
+        if (flags & VIR_STREAM_RECV_STOP_AT_HOLE) {
+            /* No error reporting here. Caller knows what they are doing. */
+            rv = -3;
+            goto cleanup;
+        }
+
         if (len > st->holeLength)
             len = st->holeLength;