proto: Fix both-ends-cancel case.

[libguestfs.git] / src / proto.c

diff --git a/src/proto.c b/src/proto.c
index 2ca24c2..cda731e 100644 (file)
--- a/src/proto.c
+++ b/src/proto.c
@@ -848,9 +848,6 @@ guestfs___send_file (guestfs_h *g, const char *filename)
   if (fd == -1) {
     perrorf (g, "open: %s", filename);
     send_file_cancellation (g);
-    /* Daemon sees cancellation and won't reply, so caller can
-     * just return here.
-     */
     return -1;
   }
 
@@ -1034,6 +1031,34 @@ guestfs___recv (guestfs_h *g, const char *fn,
   return 0;
 }
 
+/* Same as guestfs___recv, but it discards the reply message. */
+int
+guestfs___recv_discard (guestfs_h *g, const char *fn)
+{
+  void *buf;
+  uint32_t size;
+  int r;
+
+ again:
+  r = guestfs___recv_from_daemon (g, &size, &buf);
+  if (r == -1)
+    return -1;
+
+  /* This can happen if a cancellation happens right at the end
+   * of us sending a FileIn parameter to the daemon.  Discard.  The
+   * daemon should send us an error message next.
+   */
+  if (size == GUESTFS_CANCEL_FLAG)
+    goto again;
+
+  if (size == GUESTFS_LAUNCH_FLAG) {
+    error (g, "%s: received unexpected launch flag from daemon when expecting reply", fn);
+    return -1;
+  }
+
+  return 0;
+}
+
 /* Receive a file. */
 
 /* Returns -1 = error, 0 = EOF, > 0 = more data */