1025 lines
32 KiB
C
1025 lines
32 KiB
C
/*
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* Copyright (C) 2016-2017 Red Hat, Inc.
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device Client Side
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "qapi/error.h"
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#include "trace.h"
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#include "nbd-internal.h"
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/* Definitions for opaque data types */
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static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
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/* That's all folks */
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/* Basic flow for negotiation
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Server Client
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Negotiate
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or
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Server Client
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Negotiate #1
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Option
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Negotiate #2
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----
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followed by
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Server Client
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Request
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Response
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Request
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Response
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...
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...
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Request (type == 2)
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*/
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/* Send an option request.
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*
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* The request is for option @opt, with @data containing @len bytes of
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* additional payload for the request (@len may be -1 to treat @data as
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* a C string; and @data may be NULL if @len is 0).
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* Return 0 if successful, -1 with errp set if it is impossible to
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* continue. */
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static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
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uint32_t len, const char *data,
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Error **errp)
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{
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NBDOption req;
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QEMU_BUILD_BUG_ON(sizeof(req) != 16);
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if (len == -1) {
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req.length = len = strlen(data);
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}
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trace_nbd_send_option_request(opt, nbd_opt_lookup(opt), len);
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stq_be_p(&req.magic, NBD_OPTS_MAGIC);
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stl_be_p(&req.option, opt);
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stl_be_p(&req.length, len);
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if (nbd_write(ioc, &req, sizeof(req), errp) < 0) {
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error_prepend(errp, "Failed to send option request header: ");
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return -1;
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}
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if (len && nbd_write(ioc, (char *) data, len, errp) < 0) {
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error_prepend(errp, "Failed to send option request data: ");
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return -1;
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}
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return 0;
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}
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/* Send NBD_OPT_ABORT as a courtesy to let the server know that we are
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* not going to attempt further negotiation. */
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static void nbd_send_opt_abort(QIOChannel *ioc)
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{
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/* Technically, a compliant server is supposed to reply to us; but
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* older servers disconnected instead. At any rate, we're allowed
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* to disconnect without waiting for the server reply, so we don't
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* even care if the request makes it to the server, let alone
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* waiting around for whether the server replies. */
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nbd_send_option_request(ioc, NBD_OPT_ABORT, 0, NULL, NULL);
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}
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/* Receive the header of an option reply, which should match the given
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* opt. Read through the length field, but NOT the length bytes of
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* payload. Return 0 if successful, -1 with errp set if it is
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* impossible to continue. */
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static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
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NBDOptionReply *reply, Error **errp)
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{
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QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
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if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) {
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error_prepend(errp, "failed to read option reply: ");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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be64_to_cpus(&reply->magic);
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be32_to_cpus(&reply->option);
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be32_to_cpus(&reply->type);
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be32_to_cpus(&reply->length);
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trace_nbd_receive_option_reply(reply->option, nbd_opt_lookup(reply->option),
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reply->type, nbd_rep_lookup(reply->type),
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reply->length);
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if (reply->magic != NBD_REP_MAGIC) {
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error_setg(errp, "Unexpected option reply magic");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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if (reply->option != opt) {
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error_setg(errp, "Unexpected option type %x expected %x",
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reply->option, opt);
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nbd_send_opt_abort(ioc);
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return -1;
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}
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return 0;
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}
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/* If reply represents success, return 1 without further action.
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* If reply represents an error, consume the optional payload of
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* the packet on ioc. Then return 0 for unsupported (so the client
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* can fall back to other approaches), or -1 with errp set for other
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* errors.
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*/
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static int nbd_handle_reply_err(QIOChannel *ioc, NBDOptionReply *reply,
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Error **errp)
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{
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char *msg = NULL;
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int result = -1;
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if (!(reply->type & (1 << 31))) {
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return 1;
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}
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if (reply->length) {
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if (reply->length > NBD_MAX_BUFFER_SIZE) {
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error_setg(errp, "server error 0x%" PRIx32
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" (%s) message is too long",
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reply->type, nbd_rep_lookup(reply->type));
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goto cleanup;
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}
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msg = g_malloc(reply->length + 1);
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if (nbd_read(ioc, msg, reply->length, errp) < 0) {
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error_prepend(errp, "failed to read option error 0x%" PRIx32
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" (%s) message: ",
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reply->type, nbd_rep_lookup(reply->type));
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goto cleanup;
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}
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msg[reply->length] = '\0';
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}
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switch (reply->type) {
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case NBD_REP_ERR_UNSUP:
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trace_nbd_reply_err_unsup(reply->option, nbd_opt_lookup(reply->option));
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result = 0;
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goto cleanup;
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case NBD_REP_ERR_POLICY:
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error_setg(errp, "Denied by server for option %" PRIx32 " (%s)",
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reply->option, nbd_opt_lookup(reply->option));
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break;
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case NBD_REP_ERR_INVALID:
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error_setg(errp, "Invalid data length for option %" PRIx32 " (%s)",
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reply->option, nbd_opt_lookup(reply->option));
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break;
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case NBD_REP_ERR_PLATFORM:
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error_setg(errp, "Server lacks support for option %" PRIx32 " (%s)",
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reply->option, nbd_opt_lookup(reply->option));
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break;
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case NBD_REP_ERR_TLS_REQD:
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error_setg(errp, "TLS negotiation required before option %" PRIx32
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" (%s)", reply->option, nbd_opt_lookup(reply->option));
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break;
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case NBD_REP_ERR_UNKNOWN:
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error_setg(errp, "Requested export not available");
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break;
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case NBD_REP_ERR_SHUTDOWN:
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error_setg(errp, "Server shutting down before option %" PRIx32 " (%s)",
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reply->option, nbd_opt_lookup(reply->option));
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break;
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case NBD_REP_ERR_BLOCK_SIZE_REQD:
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error_setg(errp, "Server requires INFO_BLOCK_SIZE for option %" PRIx32
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" (%s)", reply->option, nbd_opt_lookup(reply->option));
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break;
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default:
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error_setg(errp, "Unknown error code when asking for option %" PRIx32
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" (%s)", reply->option, nbd_opt_lookup(reply->option));
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break;
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}
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if (msg) {
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error_append_hint(errp, "server reported: %s\n", msg);
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}
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cleanup:
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g_free(msg);
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if (result < 0) {
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nbd_send_opt_abort(ioc);
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}
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return result;
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}
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/* Process another portion of the NBD_OPT_LIST reply. Set *@match if
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* the current reply matches @want or if the server does not support
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* NBD_OPT_LIST, otherwise leave @match alone. Return 0 if iteration
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* is complete, positive if more replies are expected, or negative
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* with @errp set if an unrecoverable error occurred. */
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static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
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Error **errp)
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{
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NBDOptionReply reply;
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uint32_t len;
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uint32_t namelen;
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char name[NBD_MAX_NAME_SIZE + 1];
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int error;
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if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, &reply, errp) < 0) {
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return -1;
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}
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error = nbd_handle_reply_err(ioc, &reply, errp);
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if (error <= 0) {
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/* The server did not support NBD_OPT_LIST, so set *match on
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* the assumption that any name will be accepted. */
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*match = true;
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return error;
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}
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len = reply.length;
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if (reply.type == NBD_REP_ACK) {
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if (len != 0) {
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error_setg(errp, "length too long for option end");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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return 0;
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} else if (reply.type != NBD_REP_SERVER) {
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error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x",
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reply.type, NBD_REP_SERVER);
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nbd_send_opt_abort(ioc);
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return -1;
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}
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if (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) {
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error_setg(errp, "incorrect option length %" PRIu32, len);
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nbd_send_opt_abort(ioc);
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return -1;
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}
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if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) {
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error_prepend(errp, "failed to read option name length: ");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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namelen = be32_to_cpu(namelen);
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len -= sizeof(namelen);
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if (len < namelen) {
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error_setg(errp, "incorrect option name length");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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if (namelen != strlen(want)) {
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if (nbd_drop(ioc, len, errp) < 0) {
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error_prepend(errp,
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"failed to skip export name with wrong length: ");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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return 1;
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}
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assert(namelen < sizeof(name));
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if (nbd_read(ioc, name, namelen, errp) < 0) {
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error_prepend(errp, "failed to read export name: ");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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name[namelen] = '\0';
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len -= namelen;
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if (nbd_drop(ioc, len, errp) < 0) {
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error_prepend(errp, "failed to read export description: ");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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if (!strcmp(name, want)) {
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*match = true;
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}
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return 1;
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}
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/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be
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* used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
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* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
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* go (with @info populated). */
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static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
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NBDExportInfo *info, Error **errp)
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{
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NBDOptionReply reply;
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uint32_t len = strlen(wantname);
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uint16_t type;
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int error;
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char *buf;
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/* The protocol requires that the server send NBD_INFO_EXPORT with
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* a non-zero flags (at least NBD_FLAG_HAS_FLAGS must be set); so
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* flags still 0 is a witness of a broken server. */
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info->flags = 0;
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trace_nbd_opt_go_start(wantname);
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buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
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stl_be_p(buf, len);
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memcpy(buf + 4, wantname, len);
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/* At most one request, everything else up to server */
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stw_be_p(buf + 4 + len, info->request_sizes);
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if (info->request_sizes) {
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stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);
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}
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error = nbd_send_option_request(ioc, NBD_OPT_GO,
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4 + len + 2 + 2 * info->request_sizes,
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buf, errp);
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g_free(buf);
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if (error < 0) {
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return -1;
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}
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while (1) {
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if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {
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return -1;
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}
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error = nbd_handle_reply_err(ioc, &reply, errp);
|
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if (error <= 0) {
|
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return error;
|
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}
|
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len = reply.length;
|
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|
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if (reply.type == NBD_REP_ACK) {
|
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/* Server is done sending info and moved into transmission
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phase, but make sure it sent flags */
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if (len) {
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error_setg(errp, "server sent invalid NBD_REP_ACK");
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return -1;
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}
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if (!info->flags) {
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error_setg(errp, "broken server omitted NBD_INFO_EXPORT");
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return -1;
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}
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trace_nbd_opt_go_success();
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return 1;
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}
|
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if (reply.type != NBD_REP_INFO) {
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error_setg(errp, "unexpected reply type %" PRIx32
|
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" (%s), expected %x",
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reply.type, nbd_rep_lookup(reply.type), NBD_REP_INFO);
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nbd_send_opt_abort(ioc);
|
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return -1;
|
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}
|
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if (len < sizeof(type)) {
|
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error_setg(errp, "NBD_REP_INFO length %" PRIu32 " is too short",
|
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len);
|
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nbd_send_opt_abort(ioc);
|
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return -1;
|
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}
|
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if (nbd_read(ioc, &type, sizeof(type), errp) < 0) {
|
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error_prepend(errp, "failed to read info type: ");
|
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nbd_send_opt_abort(ioc);
|
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return -1;
|
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}
|
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len -= sizeof(type);
|
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be16_to_cpus(&type);
|
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switch (type) {
|
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case NBD_INFO_EXPORT:
|
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if (len != sizeof(info->size) + sizeof(info->flags)) {
|
|
error_setg(errp, "remaining export info len %" PRIu32
|
|
" is unexpected size", len);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
|
|
error_prepend(errp, "failed to read info size: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
be64_to_cpus(&info->size);
|
|
if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
|
|
error_prepend(errp, "failed to read info flags: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
be16_to_cpus(&info->flags);
|
|
trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
|
|
break;
|
|
|
|
case NBD_INFO_BLOCK_SIZE:
|
|
if (len != sizeof(info->min_block) * 3) {
|
|
error_setg(errp, "remaining export info len %" PRIu32
|
|
" is unexpected size", len);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read(ioc, &info->min_block, sizeof(info->min_block),
|
|
errp) < 0) {
|
|
error_prepend(errp, "failed to read info minimum block size: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
be32_to_cpus(&info->min_block);
|
|
if (!is_power_of_2(info->min_block)) {
|
|
error_setg(errp, "server minimum block size %" PRId32
|
|
"is not a power of two", info->min_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block),
|
|
errp) < 0) {
|
|
error_prepend(errp,
|
|
"failed to read info preferred block size: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
be32_to_cpus(&info->opt_block);
|
|
if (!is_power_of_2(info->opt_block) ||
|
|
info->opt_block < info->min_block) {
|
|
error_setg(errp, "server preferred block size %" PRId32
|
|
"is not valid", info->opt_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read(ioc, &info->max_block, sizeof(info->max_block),
|
|
errp) < 0) {
|
|
error_prepend(errp, "failed to read info maximum block size: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
be32_to_cpus(&info->max_block);
|
|
trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,
|
|
info->max_block);
|
|
break;
|
|
|
|
default:
|
|
trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));
|
|
if (nbd_drop(ioc, len, errp) < 0) {
|
|
error_prepend(errp, "Failed to read info payload: ");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return -1 on failure, 0 if wantname is an available export. */
|
|
static int nbd_receive_query_exports(QIOChannel *ioc,
|
|
const char *wantname,
|
|
Error **errp)
|
|
{
|
|
bool foundExport = false;
|
|
|
|
trace_nbd_receive_query_exports_start(wantname);
|
|
if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
while (1) {
|
|
int ret = nbd_receive_list(ioc, wantname, &foundExport, errp);
|
|
|
|
if (ret < 0) {
|
|
/* Server gave unexpected reply */
|
|
return -1;
|
|
} else if (ret == 0) {
|
|
/* Done iterating. */
|
|
if (!foundExport) {
|
|
error_setg(errp, "No export with name '%s' available",
|
|
wantname);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
trace_nbd_receive_query_exports_success(wantname);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* nbd_request_simple_option: Send an option request, and parse the reply
|
|
* return 1 for successful negotiation,
|
|
* 0 if operation is unsupported,
|
|
* -1 with errp set for any other error
|
|
*/
|
|
static int nbd_request_simple_option(QIOChannel *ioc, int opt, Error **errp)
|
|
{
|
|
NBDOptionReply reply;
|
|
int error;
|
|
|
|
if (nbd_send_option_request(ioc, opt, 0, NULL, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
|
|
return -1;
|
|
}
|
|
error = nbd_handle_reply_err(ioc, &reply, errp);
|
|
if (error <= 0) {
|
|
return error;
|
|
}
|
|
|
|
if (reply.type != NBD_REP_ACK) {
|
|
error_setg(errp, "Server answered option %d (%s) with unexpected "
|
|
"reply %" PRIx32 " (%s)", opt, nbd_opt_lookup(opt),
|
|
reply.type, nbd_rep_lookup(reply.type));
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
|
|
if (reply.length != 0) {
|
|
error_setg(errp, "Option %d ('%s') response length is %" PRIu32
|
|
" (it should be zero)", opt, nbd_opt_lookup(opt),
|
|
reply.length);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
|
|
QCryptoTLSCreds *tlscreds,
|
|
const char *hostname, Error **errp)
|
|
{
|
|
int ret;
|
|
QIOChannelTLS *tioc;
|
|
struct NBDTLSHandshakeData data = { 0 };
|
|
|
|
ret = nbd_request_simple_option(ioc, NBD_OPT_STARTTLS, errp);
|
|
if (ret <= 0) {
|
|
if (ret == 0) {
|
|
error_setg(errp, "Server don't support STARTTLS option");
|
|
nbd_send_opt_abort(ioc);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
trace_nbd_receive_starttls_new_client();
|
|
tioc = qio_channel_tls_new_client(ioc, tlscreds, hostname, errp);
|
|
if (!tioc) {
|
|
return NULL;
|
|
}
|
|
qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-client-tls");
|
|
data.loop = g_main_loop_new(g_main_context_default(), FALSE);
|
|
trace_nbd_receive_starttls_tls_handshake();
|
|
qio_channel_tls_handshake(tioc,
|
|
nbd_tls_handshake,
|
|
&data,
|
|
NULL);
|
|
|
|
if (!data.complete) {
|
|
g_main_loop_run(data.loop);
|
|
}
|
|
g_main_loop_unref(data.loop);
|
|
if (data.error) {
|
|
error_propagate(errp, data.error);
|
|
object_unref(OBJECT(tioc));
|
|
return NULL;
|
|
}
|
|
|
|
return QIO_CHANNEL(tioc);
|
|
}
|
|
|
|
|
|
int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
|
|
QCryptoTLSCreds *tlscreds, const char *hostname,
|
|
QIOChannel **outioc, NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
char buf[256];
|
|
uint64_t magic;
|
|
int rc;
|
|
bool zeroes = true;
|
|
bool structured_reply = info->structured_reply;
|
|
|
|
trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>");
|
|
|
|
info->structured_reply = false;
|
|
rc = -EINVAL;
|
|
|
|
if (outioc) {
|
|
*outioc = NULL;
|
|
}
|
|
if (tlscreds && !outioc) {
|
|
error_setg(errp, "Output I/O channel required for TLS");
|
|
goto fail;
|
|
}
|
|
|
|
if (nbd_read(ioc, buf, 8, errp) < 0) {
|
|
error_prepend(errp, "Failed to read data: ");
|
|
goto fail;
|
|
}
|
|
|
|
buf[8] = '\0';
|
|
if (strlen(buf) == 0) {
|
|
error_setg(errp, "Server connection closed unexpectedly");
|
|
goto fail;
|
|
}
|
|
|
|
magic = ldq_be_p(buf);
|
|
trace_nbd_receive_negotiate_magic(magic);
|
|
|
|
if (memcmp(buf, "NBDMAGIC", 8) != 0) {
|
|
error_setg(errp, "Invalid magic received");
|
|
goto fail;
|
|
}
|
|
|
|
if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
|
|
error_prepend(errp, "Failed to read magic: ");
|
|
goto fail;
|
|
}
|
|
magic = be64_to_cpu(magic);
|
|
trace_nbd_receive_negotiate_magic(magic);
|
|
|
|
if (magic == NBD_OPTS_MAGIC) {
|
|
uint32_t clientflags = 0;
|
|
uint16_t globalflags;
|
|
bool fixedNewStyle = false;
|
|
|
|
if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
|
|
error_prepend(errp, "Failed to read server flags: ");
|
|
goto fail;
|
|
}
|
|
globalflags = be16_to_cpu(globalflags);
|
|
trace_nbd_receive_negotiate_server_flags(globalflags);
|
|
if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
|
|
fixedNewStyle = true;
|
|
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
|
|
}
|
|
if (globalflags & NBD_FLAG_NO_ZEROES) {
|
|
zeroes = false;
|
|
clientflags |= NBD_FLAG_C_NO_ZEROES;
|
|
}
|
|
/* client requested flags */
|
|
clientflags = cpu_to_be32(clientflags);
|
|
if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
|
|
error_prepend(errp, "Failed to send clientflags field: ");
|
|
goto fail;
|
|
}
|
|
if (tlscreds) {
|
|
if (fixedNewStyle) {
|
|
*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
|
|
if (!*outioc) {
|
|
goto fail;
|
|
}
|
|
ioc = *outioc;
|
|
} else {
|
|
error_setg(errp, "Server does not support STARTTLS");
|
|
goto fail;
|
|
}
|
|
}
|
|
if (!name) {
|
|
trace_nbd_receive_negotiate_default_name();
|
|
name = "";
|
|
}
|
|
if (fixedNewStyle) {
|
|
int result;
|
|
|
|
if (structured_reply) {
|
|
result = nbd_request_simple_option(ioc,
|
|
NBD_OPT_STRUCTURED_REPLY,
|
|
errp);
|
|
if (result < 0) {
|
|
goto fail;
|
|
}
|
|
info->structured_reply = result == 1;
|
|
}
|
|
|
|
/* Try NBD_OPT_GO first - if it works, we are done (it
|
|
* also gives us a good message if the server requires
|
|
* TLS). If it is not available, fall back to
|
|
* NBD_OPT_LIST for nicer error messages about a missing
|
|
* export, then use NBD_OPT_EXPORT_NAME. */
|
|
result = nbd_opt_go(ioc, name, info, errp);
|
|
if (result < 0) {
|
|
goto fail;
|
|
}
|
|
if (result > 0) {
|
|
return 0;
|
|
}
|
|
/* Check our desired export is present in the
|
|
* server export list. Since NBD_OPT_EXPORT_NAME
|
|
* cannot return an error message, running this
|
|
* query gives us better error reporting if the
|
|
* export name is not available.
|
|
*/
|
|
if (nbd_receive_query_exports(ioc, name, errp) < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
/* write the export name request */
|
|
if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name,
|
|
errp) < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Read the response */
|
|
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
|
|
error_prepend(errp, "Failed to read export length: ");
|
|
goto fail;
|
|
}
|
|
be64_to_cpus(&info->size);
|
|
|
|
if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
|
|
error_prepend(errp, "Failed to read export flags: ");
|
|
goto fail;
|
|
}
|
|
be16_to_cpus(&info->flags);
|
|
} else if (magic == NBD_CLIENT_MAGIC) {
|
|
uint32_t oldflags;
|
|
|
|
if (name) {
|
|
error_setg(errp, "Server does not support export names");
|
|
goto fail;
|
|
}
|
|
if (tlscreds) {
|
|
error_setg(errp, "Server does not support STARTTLS");
|
|
goto fail;
|
|
}
|
|
|
|
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
|
|
error_prepend(errp, "Failed to read export length: ");
|
|
goto fail;
|
|
}
|
|
be64_to_cpus(&info->size);
|
|
|
|
if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
|
|
error_prepend(errp, "Failed to read export flags: ");
|
|
goto fail;
|
|
}
|
|
be32_to_cpus(&oldflags);
|
|
if (oldflags & ~0xffff) {
|
|
error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
|
|
goto fail;
|
|
}
|
|
info->flags = oldflags;
|
|
} else {
|
|
error_setg(errp, "Bad magic received");
|
|
goto fail;
|
|
}
|
|
|
|
trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
|
|
if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
|
|
error_prepend(errp, "Failed to read reserved block: ");
|
|
goto fail;
|
|
}
|
|
rc = 0;
|
|
|
|
fail:
|
|
return rc;
|
|
}
|
|
|
|
#ifdef __linux__
|
|
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
unsigned long sector_size = MAX(BDRV_SECTOR_SIZE, info->min_block);
|
|
unsigned long sectors = info->size / sector_size;
|
|
|
|
/* FIXME: Once the kernel module is patched to honor block sizes,
|
|
* and to advertise that fact to user space, we should update the
|
|
* hand-off to the kernel to use any block sizes we learned. */
|
|
assert(!info->request_sizes);
|
|
if (info->size / sector_size != sectors) {
|
|
error_setg(errp, "Export size %" PRIu64 " too large for 32-bit kernel",
|
|
info->size);
|
|
return -E2BIG;
|
|
}
|
|
|
|
trace_nbd_init_set_socket();
|
|
|
|
if (ioctl(fd, NBD_SET_SOCK, (unsigned long) sioc->fd) < 0) {
|
|
int serrno = errno;
|
|
error_setg(errp, "Failed to set NBD socket");
|
|
return -serrno;
|
|
}
|
|
|
|
trace_nbd_init_set_block_size(sector_size);
|
|
|
|
if (ioctl(fd, NBD_SET_BLKSIZE, sector_size) < 0) {
|
|
int serrno = errno;
|
|
error_setg(errp, "Failed setting NBD block size");
|
|
return -serrno;
|
|
}
|
|
|
|
trace_nbd_init_set_size(sectors);
|
|
if (info->size % sector_size) {
|
|
trace_nbd_init_trailing_bytes(info->size % sector_size);
|
|
}
|
|
|
|
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, sectors) < 0) {
|
|
int serrno = errno;
|
|
error_setg(errp, "Failed setting size (in blocks)");
|
|
return -serrno;
|
|
}
|
|
|
|
if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) info->flags) < 0) {
|
|
if (errno == ENOTTY) {
|
|
int read_only = (info->flags & NBD_FLAG_READ_ONLY) != 0;
|
|
trace_nbd_init_set_readonly();
|
|
|
|
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
|
|
int serrno = errno;
|
|
error_setg(errp, "Failed setting read-only attribute");
|
|
return -serrno;
|
|
}
|
|
} else {
|
|
int serrno = errno;
|
|
error_setg(errp, "Failed setting flags");
|
|
return -serrno;
|
|
}
|
|
}
|
|
|
|
trace_nbd_init_finish();
|
|
|
|
return 0;
|
|
}
|
|
|
|
int nbd_client(int fd)
|
|
{
|
|
int ret;
|
|
int serrno;
|
|
|
|
trace_nbd_client_loop();
|
|
|
|
ret = ioctl(fd, NBD_DO_IT);
|
|
if (ret < 0 && errno == EPIPE) {
|
|
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
|
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
|
* that case.
|
|
*/
|
|
ret = 0;
|
|
}
|
|
serrno = errno;
|
|
|
|
trace_nbd_client_loop_ret(ret, strerror(serrno));
|
|
|
|
trace_nbd_client_clear_queue();
|
|
ioctl(fd, NBD_CLEAR_QUE);
|
|
|
|
trace_nbd_client_clear_socket();
|
|
ioctl(fd, NBD_CLEAR_SOCK);
|
|
|
|
errno = serrno;
|
|
return ret;
|
|
}
|
|
|
|
int nbd_disconnect(int fd)
|
|
{
|
|
ioctl(fd, NBD_CLEAR_QUE);
|
|
ioctl(fd, NBD_DISCONNECT);
|
|
ioctl(fd, NBD_CLEAR_SOCK);
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
int nbd_init(int fd, QIOChannelSocket *ioc, NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
error_setg(errp, "nbd_init is only supported on Linux");
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int nbd_client(int fd)
|
|
{
|
|
return -ENOTSUP;
|
|
}
|
|
int nbd_disconnect(int fd)
|
|
{
|
|
return -ENOTSUP;
|
|
}
|
|
#endif
|
|
|
|
int nbd_send_request(QIOChannel *ioc, NBDRequest *request)
|
|
{
|
|
uint8_t buf[NBD_REQUEST_SIZE];
|
|
|
|
trace_nbd_send_request(request->from, request->len, request->handle,
|
|
request->flags, request->type,
|
|
nbd_cmd_lookup(request->type));
|
|
|
|
stl_be_p(buf, NBD_REQUEST_MAGIC);
|
|
stw_be_p(buf + 4, request->flags);
|
|
stw_be_p(buf + 6, request->type);
|
|
stq_be_p(buf + 8, request->handle);
|
|
stq_be_p(buf + 16, request->from);
|
|
stl_be_p(buf + 24, request->len);
|
|
|
|
return nbd_write(ioc, buf, sizeof(buf), NULL);
|
|
}
|
|
|
|
/* nbd_receive_simple_reply
|
|
* Read simple reply except magic field (which should be already read).
|
|
* Payload is not read (payload is possible for CMD_READ, but here we even
|
|
* don't know whether it take place or not).
|
|
*/
|
|
static int nbd_receive_simple_reply(QIOChannel *ioc, NBDSimpleReply *reply,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
assert(reply->magic == NBD_SIMPLE_REPLY_MAGIC);
|
|
|
|
ret = nbd_read(ioc, (uint8_t *)reply + sizeof(reply->magic),
|
|
sizeof(*reply) - sizeof(reply->magic), errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
be32_to_cpus(&reply->error);
|
|
be64_to_cpus(&reply->handle);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_receive_structured_reply_chunk
|
|
* Read structured reply chunk except magic field (which should be already
|
|
* read).
|
|
* Payload is not read.
|
|
*/
|
|
static int nbd_receive_structured_reply_chunk(QIOChannel *ioc,
|
|
NBDStructuredReplyChunk *chunk,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
assert(chunk->magic == NBD_STRUCTURED_REPLY_MAGIC);
|
|
|
|
ret = nbd_read(ioc, (uint8_t *)chunk + sizeof(chunk->magic),
|
|
sizeof(*chunk) - sizeof(chunk->magic), errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
be16_to_cpus(&chunk->flags);
|
|
be16_to_cpus(&chunk->type);
|
|
be64_to_cpus(&chunk->handle);
|
|
be32_to_cpus(&chunk->length);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_receive_reply
|
|
* Returns 1 on success
|
|
* 0 on eof, when no data was read (errp is not set)
|
|
* negative errno on failure (errp is set)
|
|
*/
|
|
int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
|
|
{
|
|
int ret;
|
|
const char *type;
|
|
|
|
ret = nbd_read_eof(ioc, &reply->magic, sizeof(reply->magic), errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
|
|
be32_to_cpus(&reply->magic);
|
|
|
|
switch (reply->magic) {
|
|
case NBD_SIMPLE_REPLY_MAGIC:
|
|
ret = nbd_receive_simple_reply(ioc, &reply->simple, errp);
|
|
if (ret < 0) {
|
|
break;
|
|
}
|
|
trace_nbd_receive_simple_reply(reply->simple.error,
|
|
nbd_err_lookup(reply->simple.error),
|
|
reply->handle);
|
|
break;
|
|
case NBD_STRUCTURED_REPLY_MAGIC:
|
|
ret = nbd_receive_structured_reply_chunk(ioc, &reply->structured, errp);
|
|
if (ret < 0) {
|
|
break;
|
|
}
|
|
type = nbd_reply_type_lookup(reply->structured.type);
|
|
trace_nbd_receive_structured_reply_chunk(reply->structured.flags,
|
|
reply->structured.type, type,
|
|
reply->structured.handle,
|
|
reply->structured.length);
|
|
break;
|
|
default:
|
|
error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", reply->magic);
|
|
return -EINVAL;
|
|
}
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|