Re: [Libguestfs] [libnbd PATCH 7/7] states: Capture NBD_REP_ERR message

Similar to the earlier patch for structured reply errors, it's worth logging (at least through debug) any error messages that the server sends alongside NBD_REP_ERR. And given our earlier changes, it doesn't really impact the size of struct nbd_handle. ---

+++ b/generator/states-newstyle.c @@ -77,6 +77,35 @@ prepare_for_reply_payload (struct nbd_handle *h, uint32_t opt) return 0; } +/* Check an unexpected server reply. If it is an error, log any + * message from the server and return 0; otherwise, return -1. + */ +static int +handle_reply_error (struct nbd_handle *h) +{ + uint32_t len; + uint32_t reply; + + len = be32toh (h->sbuf.or.option_reply.replylen); + reply = be32toh (h->sbuf.or.option_reply.reply); + if (!NBD_REP_IS_ERR (reply)) { + set_error (0, "handshake: unexpected option reply type %d", reply); + return -1; + } + + assert (NBD_MAX_STRING < sizeof h->sbuf.or.payload);