+ unsigned len;
+ int sent;
+ guestfs_chunk chunk;
+ XDR xdr;
+ guestfs_main_loop *ml = guestfs_get_main_loop (g);
+
+ if (g->state != BUSY) {
+ error (g, "send_file_chunk_sync: state %d != READY", g->state);
+ return -1;
+ }
+
+ /* This is probably an internal error. Or perhaps we should just
+ * free the buffer anyway?
+ */
+ if (g->msg_out != NULL) {
+ error (g, "guestfs__send_sync: msg_out should be NULL");
+ return -1;
+ }
+
+ /* Did the daemon send a cancellation message? */
+ if (check_for_daemon_cancellation (g)) {
+ if (g->verbose)
+ fprintf (stderr, "got daemon cancellation\n");
+ return -2;
+ }
+
+ /* Allocate the chunk buffer. Don't use the stack to avoid
+ * excessive stack usage and unnecessary copies.
+ */
+ g->msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48);
+ xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE);
+
+ /* Serialize the chunk. */
+ chunk.cancel = cancel;
+ chunk.data.data_len = buflen;
+ chunk.data.data_val = (char *) buf;
+
+ if (!xdr_guestfs_chunk (&xdr, &chunk)) {
+ error (g, "xdr_guestfs_chunk failed (buf = %p, buflen = %zu)",
+ buf, buflen);
+ xdr_destroy (&xdr);
+ goto cleanup1;
+ }
+
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ /* Reduce the size of the outgoing message buffer to the real length. */
+ g->msg_out = safe_realloc (g, g->msg_out, len + 4);
+ g->msg_out_size = len + 4;
+ g->msg_out_pos = 0;
+
+ xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE);
+ xdr_uint32_t (&xdr, &len);
+
+ if (guestfs__switch_to_sending (g) == -1)
+ goto cleanup1;
+
+ sent = 0;
+ guestfs_set_send_callback (g, send_cb, &sent);
+ if (ml->main_loop_run (ml, g) == -1)
+ goto cleanup1;
+ if (sent != 1) {
+ error (g, "send file chunk failed, see earlier error messages");
+ goto cleanup1;
+ }
+
+ return 0;
+
+ cleanup1:
+ free (g->msg_out);
+ g->msg_out = NULL;
+ g->msg_out_size = 0;
+ return -1;