Add caution subdirectory containing safety and liveness tests.

[libguestfs.git] / src / proto.c

diff --git a/src/proto.c b/src/proto.c
index a5d9d2b..490dcfd 100644 (file)
--- a/src/proto.c
+++ b/src/proto.c
@@ -404,8 +404,19 @@ guestfs___send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
     }
     if (FD_ISSET (g->sock, &rset2)) {
       r = check_for_daemon_cancellation_or_eof (g, g->sock);
-      if (r < 0)
-        return r;
+      if (r == -1)
+       return r;
+      if (r == -2) {
+       /* Daemon sent cancel message.  But to maintain
+        * synchronization we must write out the remainder of the
+        * write buffer before we return (RHBZ#576879).
+        */
+       if (xwrite (g->sock, buf, n) == -1) {
+         perrorf (g, "write");
+         return -1;
+       }
+       return -2; /* cancelled */
+      }
     }
     if (FD_ISSET (g->sock, &wset2)) {
       r = write (g->sock, buf, n);
@@ -448,6 +459,25 @@ guestfs___send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
  * will not see GUESTFS_PROGRESS_FLAG.
  */
 
+static inline void
+unexpected_end_of_file_from_daemon_error (guestfs_h *g)
+{
+#define UNEXPEOF_ERROR "unexpected end of file when reading from daemon.\n"
+#define UNEXPEOF_TEST_TOOL \
+  "Or you can run 'libguestfs-test-tool' and post the complete output into\n" \
+  "a bug report or message to the libguestfs mailing list."
+  if (!g->verbose)
+    error (g, _(UNEXPEOF_ERROR
+"This usually means the libguestfs appliance failed to start up.  Please\n"
+"enable debugging (LIBGUESTFS_DEBUG=1) and rerun the command, then look at\n"
+"the debug messages output prior to this error.\n"
+UNEXPEOF_TEST_TOOL));
+  else
+    error (g, _(UNEXPEOF_ERROR
+"See earlier debug messages.\n"
+UNEXPEOF_TEST_TOOL));
+}
+
 int
 guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
 {
@@ -516,7 +546,7 @@ guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
           return -1;
         }
         if (r == 0) {
-          error (g, _("unexpected end of file when reading from daemon"));
+          unexpected_end_of_file_from_daemon_error (g);
           child_cleanup (g);
           return -1;
         }
@@ -577,7 +607,7 @@ guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
         return -1;
       }
       if (r == 0) {
-        error (g, _("unexpected end of file when reading from daemon"));
+        unexpected_end_of_file_from_daemon_error (g);
         child_cleanup (g);
         free (*buf_rtn);
         *buf_rtn = NULL;
@@ -693,7 +723,8 @@ guestfs___accept_from_daemon (guestfs_h *g)
 }
 
 int
-guestfs___send (guestfs_h *g, int proc_nr, uint64_t progress_hint,
+guestfs___send (guestfs_h *g, int proc_nr,
+                uint64_t progress_hint, uint64_t optargs_bitmask,
                 xdrproc_t xdrp, char *args)
 {
   struct guestfs_message_header hdr;
@@ -726,7 +757,7 @@ guestfs___send (guestfs_h *g, int proc_nr, uint64_t progress_hint,
   hdr.serial = serial;
   hdr.status = GUESTFS_STATUS_OK;
   hdr.progress_hint = progress_hint;
-  hdr.optargs_bitmask = 0;
+  hdr.optargs_bitmask = optargs_bitmask;
 
   if (!xdr_guestfs_message_header (&xdr, &hdr)) {
     error (g, _("xdr_guestfs_message_header failed"));
@@ -792,9 +823,6 @@ 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;
   }
 
@@ -979,6 +1007,34 @@ 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 */