1513 lines
48 KiB
C
1513 lines
48 KiB
C
/*
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* Copyright (C) 2016-2019 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 "qemu/queue.h"
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#include "trace.h"
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#include "nbd-internal.h"
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#include "qemu/cutils.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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ERRP_GUARD();
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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), "option reply", errp) < 0) {
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nbd_send_opt_abort(ioc);
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return -1;
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}
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reply->magic = be64_to_cpu(reply->magic);
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reply->option = be32_to_cpu(reply->option);
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reply->type = be32_to_cpu(reply->type);
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reply->length = be32_to_cpu(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 %u (%s), expected %u (%s)",
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reply->option, nbd_opt_lookup(reply->option),
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opt, nbd_opt_lookup(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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/*
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* If reply represents success, return 1 without further action. If
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* reply represents an error, consume the optional payload of the
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* packet on ioc. Then return 0 for unsupported (so the client can
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* fall back to other approaches), where @strict determines if only
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* ERR_UNSUP or all errors fit that category, or -1 with errp set for
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* other errors.
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*/
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static int nbd_handle_reply_err(QIOChannel *ioc, NBDOptionReply *reply,
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bool strict, Error **errp)
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{
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ERRP_GUARD();
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g_autofree char *msg = NULL;
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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 %" PRIu32
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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 err;
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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, NULL, errp) < 0) {
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error_prepend(errp, "Failed to read option error %" PRIu32
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" (%s) message: ",
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reply->type, nbd_rep_lookup(reply->type));
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goto err;
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}
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msg[reply->length] = '\0';
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trace_nbd_server_error_msg(reply->type,
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nbd_reply_type_lookup(reply->type), msg);
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}
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if (reply->type == NBD_REP_ERR_UNSUP || !strict) {
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trace_nbd_reply_err_ignored(reply->option,
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nbd_opt_lookup(reply->option),
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reply->type, nbd_rep_lookup(reply->type));
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return 0;
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}
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switch (reply->type) {
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case NBD_REP_ERR_POLICY:
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error_setg(errp, "Denied by server for option %" PRIu32 " (%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 parameters for option %" PRIu32 " (%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 %" PRIu32 " (%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 %" PRIu32
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" (%s)", reply->option, nbd_opt_lookup(reply->option));
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error_append_hint(errp, "Did you forget a valid tls-creds?\n");
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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 %" PRIu32 " (%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 %" PRIu32
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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 %" PRIu32
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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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err:
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nbd_send_opt_abort(ioc);
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return -1;
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}
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/* nbd_receive_list:
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* Process another portion of the NBD_OPT_LIST reply, populating any
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* name received into *@name. If @description is non-NULL, and the
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* server provided a description, that is also populated. The caller
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* must eventually call g_free() on success.
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* Returns 1 if name and description were set and iteration must continue,
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* 0 if iteration is complete (including if OPT_LIST unsupported),
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* -1 with @errp set if an unrecoverable error occurred.
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*/
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static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,
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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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g_autofree char *local_name = NULL;
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g_autofree char *local_desc = NULL;
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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, true, 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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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 %u (%s), expected %u (%s)",
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reply.type, nbd_rep_lookup(reply.type),
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NBD_REP_SERVER, nbd_rep_lookup(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_read32(ioc, &namelen, "option name length", errp) < 0) {
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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(namelen);
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if (len < namelen || namelen > NBD_MAX_STRING_SIZE) {
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error_setg(errp, "incorrect name length in server's list response");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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local_name = g_malloc(namelen + 1);
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if (nbd_read(ioc, local_name, namelen, "export name", errp) < 0) {
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nbd_send_opt_abort(ioc);
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return -1;
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}
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local_name[namelen] = '\0';
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len -= namelen;
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if (len) {
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if (len > NBD_MAX_STRING_SIZE) {
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error_setg(errp, "incorrect description length in server's "
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"list response");
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nbd_send_opt_abort(ioc);
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return -1;
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}
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local_desc = g_malloc(len + 1);
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if (nbd_read(ioc, local_desc, len, "export description", errp) < 0) {
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nbd_send_opt_abort(ioc);
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return -1;
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}
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local_desc[len] = '\0';
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}
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trace_nbd_receive_list(local_name, local_desc ?: "");
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*name = g_steal_pointer(&local_name);
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if (description) {
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*description = g_steal_pointer(&local_desc);
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}
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return 1;
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}
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/*
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* nbd_opt_info_or_go:
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* Send option for NBD_OPT_INFO or NBD_OPT_GO and parse the reply.
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* Returns -1 if the option proves the export @info->name cannot be
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* used, 0 if the option 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 the rest of @info populated).
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*/
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static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,
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NBDExportInfo *info, Error **errp)
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{
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ERRP_GUARD();
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NBDOptionReply reply;
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uint32_t len = strlen(info->name);
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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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assert(opt == NBD_OPT_GO || opt == NBD_OPT_INFO);
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trace_nbd_opt_info_go_start(nbd_opt_lookup(opt), info->name);
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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, info->name, 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, opt,
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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, opt, &reply, errp) < 0) {
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return -1;
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}
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error = nbd_handle_reply_err(ioc, &reply, true, 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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/*
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* Server is done sending info, and moved into transmission
|
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* phase for NBD_OPT_GO, but make sure it sent flags
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*/
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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_info_go_success(nbd_opt_lookup(opt));
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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 %u (%s), expected %u (%s)",
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reply.type, nbd_rep_lookup(reply.type),
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NBD_REP_INFO, nbd_rep_lookup(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_read16(ioc, &type, "info type", errp) < 0) {
|
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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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switch (type) {
|
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case NBD_INFO_EXPORT:
|
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if (len != sizeof(info->size) + sizeof(info->flags)) {
|
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error_setg(errp, "remaining export info len %" PRIu32
|
|
" is unexpected size", len);
|
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nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
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if (nbd_read64(ioc, &info->size, "info size", errp) < 0) {
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read16(ioc, &info->flags, "info flags", errp) < 0) {
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (info->min_block &&
|
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!QEMU_IS_ALIGNED(info->size, info->min_block)) {
|
|
error_setg(errp, "export size %" PRIu64 " is not multiple of "
|
|
"minimum block size %" PRIu32, info->size,
|
|
info->min_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
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_read32(ioc, &info->min_block, "info minimum block size",
|
|
errp) < 0) {
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (!is_power_of_2(info->min_block)) {
|
|
error_setg(errp, "server minimum block size %" PRIu32
|
|
" is not a power of two", info->min_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read32(ioc, &info->opt_block, "info preferred block size",
|
|
errp) < 0)
|
|
{
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (!is_power_of_2(info->opt_block) ||
|
|
info->opt_block < info->min_block) {
|
|
error_setg(errp, "server preferred block size %" PRIu32
|
|
" is not valid", info->opt_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (nbd_read32(ioc, &info->max_block, "info maximum block size",
|
|
errp) < 0)
|
|
{
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
if (info->max_block < info->min_block) {
|
|
error_setg(errp, "server maximum block size %" PRIu32
|
|
" is not valid", info->max_block);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
trace_nbd_opt_info_block_size(info->min_block, info->opt_block,
|
|
info->max_block);
|
|
break;
|
|
|
|
default:
|
|
/*
|
|
* Not worth the bother to check if NBD_INFO_NAME or
|
|
* NBD_INFO_DESCRIPTION exceed NBD_MAX_STRING_SIZE.
|
|
*/
|
|
trace_nbd_opt_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 list_empty = true;
|
|
bool found_export = 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) {
|
|
char *name;
|
|
int ret = nbd_receive_list(ioc, &name, NULL, errp);
|
|
|
|
if (ret < 0) {
|
|
/* Server gave unexpected reply */
|
|
return -1;
|
|
} else if (ret == 0) {
|
|
/* Done iterating. */
|
|
if (list_empty) {
|
|
/*
|
|
* We don't have enough context to tell a server that
|
|
* sent an empty list apart from a server that does
|
|
* not support the list command; but as this function
|
|
* is just used to trigger a nicer error message
|
|
* before trying NBD_OPT_EXPORT_NAME, assume the
|
|
* export is available.
|
|
*/
|
|
return 0;
|
|
} else if (!found_export) {
|
|
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;
|
|
}
|
|
list_empty = false;
|
|
if (!strcmp(name, wantname)) {
|
|
found_export = true;
|
|
}
|
|
g_free(name);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* nbd_request_simple_option: Send an option request, and parse the reply.
|
|
* @strict controls whether ERR_UNSUP or all errors produce 0 status.
|
|
* 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, bool strict,
|
|
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, strict, errp);
|
|
if (error <= 0) {
|
|
return error;
|
|
}
|
|
|
|
if (reply.type != NBD_REP_ACK) {
|
|
error_setg(errp, "Server answered option %d (%s) with unexpected "
|
|
"reply %" PRIu32 " (%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, true, 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,
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* nbd_send_meta_query:
|
|
* Send 0 or 1 set/list meta context queries.
|
|
* Return 0 on success, -1 with errp set for any error
|
|
*/
|
|
static int nbd_send_meta_query(QIOChannel *ioc, uint32_t opt,
|
|
const char *export, const char *query,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
uint32_t export_len = strlen(export);
|
|
uint32_t queries = !!query;
|
|
uint32_t query_len = 0;
|
|
uint32_t data_len;
|
|
char *data;
|
|
char *p;
|
|
|
|
data_len = sizeof(export_len) + export_len + sizeof(queries);
|
|
assert(export_len <= NBD_MAX_STRING_SIZE);
|
|
if (query) {
|
|
query_len = strlen(query);
|
|
data_len += sizeof(query_len) + query_len;
|
|
assert(query_len <= NBD_MAX_STRING_SIZE);
|
|
} else {
|
|
assert(opt == NBD_OPT_LIST_META_CONTEXT);
|
|
}
|
|
p = data = g_malloc(data_len);
|
|
|
|
trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export);
|
|
stl_be_p(p, export_len);
|
|
memcpy(p += sizeof(export_len), export, export_len);
|
|
stl_be_p(p += export_len, queries);
|
|
if (query) {
|
|
stl_be_p(p += sizeof(queries), query_len);
|
|
memcpy(p += sizeof(query_len), query, query_len);
|
|
}
|
|
|
|
ret = nbd_send_option_request(ioc, opt, data_len, data, errp);
|
|
g_free(data);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* nbd_receive_one_meta_context:
|
|
* Called in a loop to receive and trace one set/list meta context reply.
|
|
* Pass non-NULL @name or @id to collect results back to the caller, which
|
|
* must eventually call g_free().
|
|
* return 1 if name is set and iteration must continue,
|
|
* 0 if iteration is complete (including if option is unsupported),
|
|
* -1 with errp set for any error
|
|
*/
|
|
static int nbd_receive_one_meta_context(QIOChannel *ioc,
|
|
uint32_t opt,
|
|
char **name,
|
|
uint32_t *id,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
NBDOptionReply reply;
|
|
char *local_name = NULL;
|
|
uint32_t local_id;
|
|
|
|
if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
ret = nbd_handle_reply_err(ioc, &reply, false, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (reply.type == NBD_REP_ACK) {
|
|
if (reply.length != 0) {
|
|
error_setg(errp, "Unexpected length to ACK response");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
return 0;
|
|
} else if (reply.type != NBD_REP_META_CONTEXT) {
|
|
error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
|
|
reply.type, nbd_rep_lookup(reply.type),
|
|
NBD_REP_META_CONTEXT, nbd_rep_lookup(NBD_REP_META_CONTEXT));
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
|
|
if (reply.length <= sizeof(local_id) ||
|
|
reply.length > NBD_MAX_BUFFER_SIZE) {
|
|
error_setg(errp, "Failed to negotiate meta context, server "
|
|
"answered with unexpected length %" PRIu32,
|
|
reply.length);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
|
|
if (nbd_read32(ioc, &local_id, "context id", errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
reply.length -= sizeof(local_id);
|
|
local_name = g_malloc(reply.length + 1);
|
|
if (nbd_read(ioc, local_name, reply.length, "context name", errp) < 0) {
|
|
g_free(local_name);
|
|
return -1;
|
|
}
|
|
local_name[reply.length] = '\0';
|
|
trace_nbd_opt_meta_reply(nbd_opt_lookup(opt), local_name, local_id);
|
|
|
|
if (name) {
|
|
*name = local_name;
|
|
} else {
|
|
g_free(local_name);
|
|
}
|
|
if (id) {
|
|
*id = local_id;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* nbd_negotiate_simple_meta_context:
|
|
* Request the server to set the meta context for export @info->name
|
|
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
|
|
* setting @info->context_id to the resulting id. Fail if the server
|
|
* responds with more than one context or with a context different
|
|
* than the query.
|
|
* return 1 for successful negotiation,
|
|
* 0 if operation is unsupported,
|
|
* -1 with errp set for any other error
|
|
*/
|
|
static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
|
|
NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
/*
|
|
* TODO: Removing the x_dirty_bitmap hack will mean refactoring
|
|
* this function to request and store ids for multiple contexts
|
|
* (both base:allocation and a dirty bitmap), at which point this
|
|
* function should lose the term _simple.
|
|
*/
|
|
int ret;
|
|
const char *context = info->x_dirty_bitmap ?: "base:allocation";
|
|
bool received = false;
|
|
char *name = NULL;
|
|
|
|
if (nbd_send_meta_query(ioc, NBD_OPT_SET_META_CONTEXT,
|
|
info->name, context, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
|
|
&name, &info->context_id, errp);
|
|
if (ret < 0) {
|
|
return -1;
|
|
}
|
|
if (ret == 1) {
|
|
if (strcmp(context, name)) {
|
|
error_setg(errp, "Failed to negotiate meta context '%s', server "
|
|
"answered with different context '%s'", context,
|
|
name);
|
|
g_free(name);
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
g_free(name);
|
|
received = true;
|
|
|
|
ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
|
|
NULL, NULL, errp);
|
|
if (ret < 0) {
|
|
return -1;
|
|
}
|
|
}
|
|
if (ret != 0) {
|
|
error_setg(errp, "Server answered with more than one context");
|
|
nbd_send_opt_abort(ioc);
|
|
return -1;
|
|
}
|
|
return received;
|
|
}
|
|
|
|
/*
|
|
* nbd_list_meta_contexts:
|
|
* Request the server to list all meta contexts for export @info->name.
|
|
* return 0 if list is complete (even if empty),
|
|
* -1 with errp set for any error
|
|
*/
|
|
static int nbd_list_meta_contexts(QIOChannel *ioc,
|
|
NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
int seen_any = false;
|
|
int seen_qemu = false;
|
|
|
|
if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
|
|
info->name, NULL, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
while (1) {
|
|
char *context;
|
|
|
|
ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
|
|
&context, NULL, errp);
|
|
if (ret == 0 && seen_any && !seen_qemu) {
|
|
/*
|
|
* Work around qemu 3.0 bug: the server forgot to send
|
|
* "qemu:" replies to 0 queries. If we saw at least one
|
|
* reply (probably base:allocation), but none of them were
|
|
* qemu:, then run a more specific query to make sure.
|
|
*/
|
|
seen_qemu = true;
|
|
if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
|
|
info->name, "qemu:", errp) < 0) {
|
|
return -1;
|
|
}
|
|
continue;
|
|
}
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
seen_any = true;
|
|
seen_qemu |= strstart(context, "qemu:", NULL);
|
|
info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
|
|
info->contexts[info->n_contexts - 1] = context;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* nbd_start_negotiate:
|
|
* Start the handshake to the server. After a positive return, the server
|
|
* is ready to accept additional NBD_OPT requests.
|
|
* Returns: negative errno: failure talking to server
|
|
* 0: server is oldstyle, must call nbd_negotiate_finish_oldstyle
|
|
* 1: server is newstyle, but can only accept EXPORT_NAME
|
|
* 2: server is newstyle, but lacks structured replies
|
|
* 3: server is newstyle and set up for structured replies
|
|
*/
|
|
static int nbd_start_negotiate(AioContext *aio_context, QIOChannel *ioc,
|
|
QCryptoTLSCreds *tlscreds,
|
|
const char *hostname, QIOChannel **outioc,
|
|
bool structured_reply, bool *zeroes,
|
|
Error **errp)
|
|
{
|
|
ERRP_GUARD();
|
|
uint64_t magic;
|
|
|
|
trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>");
|
|
|
|
if (zeroes) {
|
|
*zeroes = true;
|
|
}
|
|
if (outioc) {
|
|
*outioc = NULL;
|
|
}
|
|
if (tlscreds && !outioc) {
|
|
error_setg(errp, "Output I/O channel required for TLS");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read64(ioc, &magic, "initial magic", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
trace_nbd_receive_negotiate_magic(magic);
|
|
|
|
if (magic != NBD_INIT_MAGIC) {
|
|
error_setg(errp, "Bad initial magic received: 0x%" PRIx64, magic);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read64(ioc, &magic, "server magic", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
trace_nbd_receive_negotiate_magic(magic);
|
|
|
|
if (magic == NBD_OPTS_MAGIC) {
|
|
uint32_t clientflags = 0;
|
|
uint16_t globalflags;
|
|
bool fixedNewStyle = false;
|
|
|
|
if (nbd_read16(ioc, &globalflags, "server flags", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
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) {
|
|
if (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: ");
|
|
return -EINVAL;
|
|
}
|
|
if (tlscreds) {
|
|
if (fixedNewStyle) {
|
|
*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
|
|
if (!*outioc) {
|
|
return -EINVAL;
|
|
}
|
|
ioc = *outioc;
|
|
if (aio_context) {
|
|
qio_channel_set_blocking(ioc, false, NULL);
|
|
qio_channel_attach_aio_context(ioc, aio_context);
|
|
}
|
|
} else {
|
|
error_setg(errp, "Server does not support STARTTLS");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (fixedNewStyle) {
|
|
int result = 0;
|
|
|
|
if (structured_reply) {
|
|
result = nbd_request_simple_option(ioc,
|
|
NBD_OPT_STRUCTURED_REPLY,
|
|
false, errp);
|
|
if (result < 0) {
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
return 2 + result;
|
|
} else {
|
|
return 1;
|
|
}
|
|
} else if (magic == NBD_CLIENT_MAGIC) {
|
|
if (tlscreds) {
|
|
error_setg(errp, "Server does not support STARTTLS");
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
} else {
|
|
error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* nbd_negotiate_finish_oldstyle:
|
|
* Populate @info with the size and export flags from an oldstyle server,
|
|
* but does not consume 124 bytes of reserved zero padding.
|
|
* Returns 0 on success, -1 with @errp set on failure
|
|
*/
|
|
static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info,
|
|
Error **errp)
|
|
{
|
|
uint32_t oldflags;
|
|
|
|
if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read32(ioc, &oldflags, "export flags", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
if (oldflags & ~0xffff) {
|
|
error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
|
|
return -EINVAL;
|
|
}
|
|
info->flags = oldflags;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* nbd_receive_negotiate:
|
|
* Connect to server, complete negotiation, and move into transmission phase.
|
|
* Returns: negative errno: failure talking to server
|
|
* 0: server is connected
|
|
*/
|
|
int nbd_receive_negotiate(AioContext *aio_context, QIOChannel *ioc,
|
|
QCryptoTLSCreds *tlscreds,
|
|
const char *hostname, QIOChannel **outioc,
|
|
NBDExportInfo *info, Error **errp)
|
|
{
|
|
ERRP_GUARD();
|
|
int result;
|
|
bool zeroes;
|
|
bool base_allocation = info->base_allocation;
|
|
|
|
assert(info->name && strlen(info->name) <= NBD_MAX_STRING_SIZE);
|
|
trace_nbd_receive_negotiate_name(info->name);
|
|
|
|
result = nbd_start_negotiate(aio_context, ioc, tlscreds, hostname, outioc,
|
|
info->structured_reply, &zeroes, errp);
|
|
|
|
info->structured_reply = false;
|
|
info->base_allocation = false;
|
|
if (tlscreds && *outioc) {
|
|
ioc = *outioc;
|
|
}
|
|
|
|
switch (result) {
|
|
case 3: /* newstyle, with structured replies */
|
|
info->structured_reply = true;
|
|
if (base_allocation) {
|
|
result = nbd_negotiate_simple_meta_context(ioc, info, errp);
|
|
if (result < 0) {
|
|
return -EINVAL;
|
|
}
|
|
info->base_allocation = result == 1;
|
|
}
|
|
/* fall through */
|
|
case 2: /* newstyle, try OPT_GO */
|
|
/* 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_info_or_go(ioc, NBD_OPT_GO, info, errp);
|
|
if (result < 0) {
|
|
return -EINVAL;
|
|
}
|
|
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, info->name, errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
/* fall through */
|
|
case 1: /* newstyle, but limited to EXPORT_NAME */
|
|
/* write the export name request */
|
|
if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,
|
|
errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Read the response */
|
|
if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read16(ioc, &info->flags, "export flags", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
case 0: /* oldstyle, parse length and flags */
|
|
if (*info->name) {
|
|
error_setg(errp, "Server does not support non-empty export names");
|
|
return -EINVAL;
|
|
}
|
|
if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
default:
|
|
return result;
|
|
}
|
|
|
|
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: ");
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Clean up result of nbd_receive_export_list */
|
|
void nbd_free_export_list(NBDExportInfo *info, int count)
|
|
{
|
|
int i, j;
|
|
|
|
if (!info) {
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
g_free(info[i].name);
|
|
g_free(info[i].description);
|
|
for (j = 0; j < info[i].n_contexts; j++) {
|
|
g_free(info[i].contexts[j]);
|
|
}
|
|
g_free(info[i].contexts);
|
|
}
|
|
g_free(info);
|
|
}
|
|
|
|
/*
|
|
* nbd_receive_export_list:
|
|
* Query details about a server's exports, then disconnect without
|
|
* going into transmission phase. Return a count of the exports listed
|
|
* in @info by the server, or -1 on error. Caller must free @info using
|
|
* nbd_free_export_list().
|
|
*/
|
|
int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
|
|
const char *hostname, NBDExportInfo **info,
|
|
Error **errp)
|
|
{
|
|
int result;
|
|
int count = 0;
|
|
int i;
|
|
int rc;
|
|
int ret = -1;
|
|
NBDExportInfo *array = NULL;
|
|
QIOChannel *sioc = NULL;
|
|
|
|
*info = NULL;
|
|
result = nbd_start_negotiate(NULL, ioc, tlscreds, hostname, &sioc, true,
|
|
NULL, errp);
|
|
if (tlscreds && sioc) {
|
|
ioc = sioc;
|
|
}
|
|
|
|
switch (result) {
|
|
case 2:
|
|
case 3:
|
|
/* newstyle - use NBD_OPT_LIST to populate array, then try
|
|
* NBD_OPT_INFO on each array member. If structured replies
|
|
* are enabled, also try NBD_OPT_LIST_META_CONTEXT. */
|
|
if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
|
|
goto out;
|
|
}
|
|
while (1) {
|
|
char *name;
|
|
char *desc;
|
|
|
|
rc = nbd_receive_list(ioc, &name, &desc, errp);
|
|
if (rc < 0) {
|
|
goto out;
|
|
} else if (rc == 0) {
|
|
break;
|
|
}
|
|
array = g_renew(NBDExportInfo, array, ++count);
|
|
memset(&array[count - 1], 0, sizeof(*array));
|
|
array[count - 1].name = name;
|
|
array[count - 1].description = desc;
|
|
array[count - 1].structured_reply = result == 3;
|
|
}
|
|
|
|
for (i = 0; i < count; i++) {
|
|
array[i].request_sizes = true;
|
|
rc = nbd_opt_info_or_go(ioc, NBD_OPT_INFO, &array[i], errp);
|
|
if (rc < 0) {
|
|
goto out;
|
|
} else if (rc == 0) {
|
|
/*
|
|
* Pointless to try rest of loop. If OPT_INFO doesn't work,
|
|
* it's unlikely that meta contexts work either
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if (result == 3 &&
|
|
nbd_list_meta_contexts(ioc, &array[i], errp) < 0) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Send NBD_OPT_ABORT as a courtesy before hanging up */
|
|
nbd_send_opt_abort(ioc);
|
|
break;
|
|
case 1: /* newstyle, but limited to EXPORT_NAME */
|
|
error_setg(errp, "Server does not support export lists");
|
|
/* We can't even send NBD_OPT_ABORT, so merely hang up */
|
|
goto out;
|
|
case 0: /* oldstyle, parse length and flags */
|
|
array = g_new0(NBDExportInfo, 1);
|
|
array->name = g_strdup("");
|
|
count = 1;
|
|
|
|
if (nbd_negotiate_finish_oldstyle(ioc, array, errp) < 0) {
|
|
goto out;
|
|
}
|
|
|
|
/* Send NBD_CMD_DISC as a courtesy to the server, but ignore all
|
|
* errors now that we have the information we wanted. */
|
|
if (nbd_drop(ioc, 124, NULL) == 0) {
|
|
NBDRequest request = { .type = NBD_CMD_DISC };
|
|
|
|
nbd_send_request(ioc, &request);
|
|
}
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
*info = array;
|
|
array = NULL;
|
|
ret = count;
|
|
|
|
out:
|
|
qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
|
|
qio_channel_close(ioc, NULL);
|
|
object_unref(OBJECT(sioc));
|
|
nbd_free_export_list(array, count);
|
|
return ret;
|
|
}
|
|
|
|
#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;
|
|
}
|
|
|
|
#endif /* __linux__ */
|
|
|
|
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), "reply", errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
reply->error = be32_to_cpu(reply->error);
|
|
reply->handle = be64_to_cpu(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), "structured chunk",
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
chunk->flags = be16_to_cpu(chunk->flags);
|
|
chunk->type = be16_to_cpu(chunk->type);
|
|
chunk->handle = be64_to_cpu(chunk->handle);
|
|
chunk->length = be32_to_cpu(chunk->length);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_read_eof
|
|
* Tries to read @size bytes from @ioc.
|
|
* Returns 1 on success
|
|
* 0 on eof, when no data was read (errp is not set)
|
|
* negative errno on failure (errp is set)
|
|
*/
|
|
static inline int coroutine_fn
|
|
nbd_read_eof(BlockDriverState *bs, QIOChannel *ioc, void *buffer, size_t size,
|
|
Error **errp)
|
|
{
|
|
bool partial = false;
|
|
|
|
assert(size);
|
|
while (size > 0) {
|
|
struct iovec iov = { .iov_base = buffer, .iov_len = size };
|
|
ssize_t len;
|
|
|
|
len = qio_channel_readv(ioc, &iov, 1, errp);
|
|
if (len == QIO_CHANNEL_ERR_BLOCK) {
|
|
qio_channel_yield(ioc, G_IO_IN);
|
|
continue;
|
|
} else if (len < 0) {
|
|
return -EIO;
|
|
} else if (len == 0) {
|
|
if (partial) {
|
|
error_setg(errp,
|
|
"Unexpected end-of-file before all bytes were read");
|
|
return -EIO;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
partial = true;
|
|
size -= len;
|
|
buffer = (uint8_t*) buffer + len;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* nbd_receive_reply
|
|
*
|
|
* Decreases bs->in_flight while waiting for a new reply. This yield is where
|
|
* we wait indefinitely and the coroutine must be able to be safely reentered
|
|
* for nbd_client_attach_aio_context().
|
|
*
|
|
* Returns 1 on success
|
|
* 0 on eof, when no data was read (errp is not set)
|
|
* negative errno on failure (errp is set)
|
|
*/
|
|
int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc,
|
|
NBDReply *reply, Error **errp)
|
|
{
|
|
int ret;
|
|
const char *type;
|
|
|
|
ret = nbd_read_eof(bs, ioc, &reply->magic, sizeof(reply->magic), errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
|
|
reply->magic = be32_to_cpu(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;
|
|
}
|
|
|