From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> namelen should be here, length is unrelated, and always 0 at this point. Broken in introduction in commit f37708f6, but mostly harmless (replying with '' as the name does not violate protocol, and does not confuse qemu as the nbd client since our implementation does not ask for the name; but might confuse some other client that does ask for the name especially if the default export is different than the export name being queried).
Adding an assert makes it obvious that we are not skipping any bytes in the client's message, as well as making it obvious that we were using the wrong variable. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> CC: qemu-sta...@nongnu.org Message-Id: <20171101154204.27146-1-vsement...@virtuozzo.com> [eblake: improve commit message, squash in assert addition] Signed-off-by: Eric Blake <ebl...@redhat.com> --- nbd/server.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/nbd/server.c b/nbd/server.c index 70b40ed27e..bcf0cdb47c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -423,6 +423,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint32_t length, break; } } + assert(length == 0); exp = nbd_export_find(name); if (!exp) { @@ -433,7 +434,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint32_t length, /* Don't bother sending NBD_INFO_NAME unless client requested it */ if (sendname) { - rc = nbd_negotiate_send_info(client, opt, NBD_INFO_NAME, length, name, + rc = nbd_negotiate_send_info(client, opt, NBD_INFO_NAME, namelen, name, errp); if (rc < 0) { return rc; -- 2.13.6