}
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);
* 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)
{
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;
}
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;
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;
}
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 */