Parses return values and returned errors properly.

[libguestfs.git] / src / guestfs.c

diff --git a/src/guestfs.c b/src/guestfs.c
index 309cd15..47af20a 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -170,6 +170,11 @@ guestfs_create (void)
   str = getenv ("LIBGUESTFS_DEBUG");
   g->verbose = str != NULL && strcmp (str, "1") == 0;
 
+  /* Start with large serial numbers so they are easy to spot
+   * inside the protocol.
+   */
+  g->msg_next_serial = 0x00123400;
+
   return g;
 }
 
@@ -492,7 +497,8 @@ guestfs_launch (guestfs_h *g)
              "console=ttyS0 guestfs=%s:%d", VMCHANNEL_ADDR, VMCHANNEL_PORT);
 
     add_cmdline (g, "-m");
-    add_cmdline (g, "384");    /* XXX Choose best size. */
+    add_cmdline (g, "384");      /* XXX Choose best size. */
+    add_cmdline (g, "-no-kqemu"); /* Avoids a warning. */
     add_cmdline (g, "-kernel");
     add_cmdline (g, (char *) kernel);
     add_cmdline (g, "-initrd");
@@ -862,13 +868,13 @@ sock_read_event (void *data, int watch, int fd, int events)
     goto cleanup;
   }
 
-  if (g->msg_in_size < len) return; /* Need more of this message. */
+  if (g->msg_in_size-4 < len) return; /* Need more of this message. */
 
   /* This should not happen, and if it does it probably means we've
    * lost all hope of synchronization.
    */
-  if (g->msg_in_size > len) {
-    error (g, "len = %d, but msg_in_size = %d", len, g->msg_in_size);
+  if (g->msg_in_size-4 > len) {
+    error (g, "len = %d, but msg_in_size-4 = %d", len, g->msg_in_size-4);
     goto cleanup;
   }
 
@@ -944,7 +950,7 @@ sock_write_event (void *data, int watch, int fd, int events)
     return;
 
   if (g->verbose)
-    fprintf (stderr, "sock_write_event: done writing, switching back to reading events\n", n);
+    fprintf (stderr, "sock_write_event: done writing, switching back to reading events\n");
 
   free (g->msg_out);
   g->msg_out_pos = g->msg_out_size = 0;
@@ -1047,6 +1053,38 @@ dispatch (guestfs_h *g, int proc_nr, xdrproc_t xdrp, char *args)
   return -1;
 }
 
+/* Check the return message from a call for validity. */
+static int
+check_reply_header (guestfs_h *g,
+                   const struct guestfs_message_header *hdr,
+                   int proc_nr, int serial)
+{
+  if (hdr->prog != GUESTFS_PROGRAM) {
+    error (g, "wrong program (%d/%d)", hdr->prog, GUESTFS_PROGRAM);
+    return -1;
+  }
+  if (hdr->vers != GUESTFS_PROTOCOL_VERSION) {
+    error (g, "wrong protocol version (%d/%d)",
+          hdr->vers, GUESTFS_PROTOCOL_VERSION);
+    return -1;
+  }
+  if (hdr->direction != GUESTFS_DIRECTION_REPLY) {
+    error (g, "unexpected message direction (%d/%d)",
+          hdr->direction, GUESTFS_DIRECTION_REPLY);
+    return -1;
+  }
+  if (hdr->proc != proc_nr) {
+    error (g, "unexpected procedure number (%d/%d)", hdr->proc, proc_nr);
+    return -1;
+  }
+  if (hdr->serial != serial) {
+    error (g, "unexpected serial (%d/%d)", hdr->serial, serial);
+    return -1;
+  }
+
+  return 0;
+}
+
 /* The high-level actions are autogenerated by generator.ml.  Include
  * them here.
  */