diff options
| -rw-r--r-- | nbd/client.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/nbd/client.c b/nbd/client.c index e78000a28a..651e08cd3a 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -111,6 +111,19 @@ static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt, return 0; } +/* Send NBD_OPT_ABORT as a courtesy to let the server know that we are + * not going to attempt further negotiation. */ +static void nbd_send_opt_abort(QIOChannel *ioc) +{ + /* Technically, a compliant server is supposed to reply to us; but + * older servers disconnected instead. At any rate, we're allowed + * to disconnect without waiting for the server reply, so we don't + * even care if the request makes it to the server, let alone + * waiting around for whether the server replies. */ + nbd_send_option_request(ioc, NBD_OPT_ABORT, 0, NULL, NULL); +} + + /* Receive the header of an option reply, which should match the given * opt. Read through the length field, but NOT the length bytes of * payload. Return 0 if successful, -1 with errp set if it is @@ -121,6 +134,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, QEMU_BUILD_BUG_ON(sizeof(*reply) != 20); if (read_sync(ioc, reply, sizeof(*reply)) != sizeof(*reply)) { error_setg(errp, "failed to read option reply"); + nbd_send_opt_abort(ioc); return -1; } be64_to_cpus(&reply->magic); @@ -133,11 +147,13 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, if (reply->magic != NBD_REP_MAGIC) { error_setg(errp, "Unexpected option reply magic"); + nbd_send_opt_abort(ioc); return -1; } if (reply->option != opt) { error_setg(errp, "Unexpected option type %x expected %x", reply->option, opt); + nbd_send_opt_abort(ioc); return -1; } return 0; @@ -206,6 +222,9 @@ static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply, cleanup: g_free(msg); + if (result < 0) { + nbd_send_opt_abort(ioc); + } return result; } @@ -229,25 +248,30 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) if (reply.type == NBD_REP_ACK) { if (len != 0) { error_setg(errp, "length too long for option end"); + nbd_send_opt_abort(ioc); return -1; } } else if (reply.type == NBD_REP_SERVER) { if (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "incorrect option length %" PRIu32, len); + nbd_send_opt_abort(ioc); return -1; } if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) { error_setg(errp, "failed to read option name length"); + nbd_send_opt_abort(ioc); return -1; } namelen = be32_to_cpu(namelen); len -= sizeof(namelen); if (len < namelen) { error_setg(errp, "incorrect option name length"); + nbd_send_opt_abort(ioc); return -1; } if (namelen > NBD_MAX_NAME_SIZE) { error_setg(errp, "export name length too long %" PRIu32, namelen); + nbd_send_opt_abort(ioc); return -1; } @@ -256,6 +280,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) error_setg(errp, "failed to read export name"); g_free(*name); *name = NULL; + nbd_send_opt_abort(ioc); return -1; } (*name)[namelen] = '\0'; @@ -267,6 +292,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) g_free(*name); g_free(buf); *name = NULL; + nbd_send_opt_abort(ioc); return -1; } buf[len] = '\0'; @@ -276,6 +302,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp) } else { error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x", reply.type, NBD_REP_SERVER); + nbd_send_opt_abort(ioc); return -1; } return 1; @@ -325,6 +352,7 @@ static int nbd_receive_query_exports(QIOChannel *ioc, if (!foundExport) { error_setg(errp, "No export with name '%s' available", wantname); + nbd_send_opt_abort(ioc); return -1; } @@ -352,12 +380,14 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc, if (reply.type != NBD_REP_ACK) { error_setg(errp, "Server rejected request to start TLS %" PRIx32, reply.type); + nbd_send_opt_abort(ioc); return NULL; } if (reply.length != 0) { error_setg(errp, "Start TLS response was not zero %" PRIu32, reply.length); + nbd_send_opt_abort(ioc); return NULL; } |