qemu/block/nbd.c

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/*
* QEMU Block driver for NBD
*
* Copyright (C) 2008 Bull S.A.S.
* Author: Laurent Vivier <Laurent.Vivier@bull.net>
*
* Some parts:
* Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "block/nbd-client.h"
#include "qemu/uri.h"
#include "block/block_int.h"
#include "qemu/module.h"
#include "qemu/sockets.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/qint.h"
#include "qapi/qmp/qstring.h"
#include <sys/types.h>
#include <unistd.h>
#define EN_OPTSTR ":exportname="
typedef struct BDRVNBDState {
NbdClientSession client;
QemuOpts *socket_opts;
} BDRVNBDState;
static int nbd_parse_uri(const char *filename, QDict *options)
{
URI *uri;
const char *p;
QueryParams *qp = NULL;
int ret = 0;
bool is_unix;
uri = uri_parse(filename);
if (!uri) {
return -EINVAL;
}
/* transport */
if (!strcmp(uri->scheme, "nbd")) {
is_unix = false;
} else if (!strcmp(uri->scheme, "nbd+tcp")) {
is_unix = false;
} else if (!strcmp(uri->scheme, "nbd+unix")) {
is_unix = true;
} else {
ret = -EINVAL;
goto out;
}
p = uri->path ? uri->path : "/";
p += strspn(p, "/");
if (p[0]) {
qdict_put(options, "export", qstring_from_str(p));
}
qp = query_params_parse(uri->query);
if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
ret = -EINVAL;
goto out;
}
if (is_unix) {
/* nbd+unix:///export?socket=path */
if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {
ret = -EINVAL;
goto out;
}
qdict_put(options, "path", qstring_from_str(qp->p[0].value));
} else {
QString *host;
/* nbd[+tcp]://host[:port]/export */
if (!uri->server) {
ret = -EINVAL;
goto out;
}
/* strip braces from literal IPv6 address */
if (uri->server[0] == '[') {
host = qstring_from_substr(uri->server, 1,
strlen(uri->server) - 2);
} else {
host = qstring_from_str(uri->server);
}
qdict_put(options, "host", host);
if (uri->port) {
char* port_str = g_strdup_printf("%d", uri->port);
qdict_put(options, "port", qstring_from_str(port_str));
g_free(port_str);
}
}
out:
if (qp) {
query_params_free(qp);
}
uri_free(uri);
return ret;
}
static void nbd_parse_filename(const char *filename, QDict *options,
Error **errp)
{
char *file;
char *export_name;
const char *host_spec;
const char *unixpath;
if (qdict_haskey(options, "host")
|| qdict_haskey(options, "port")
|| qdict_haskey(options, "path"))
{
error_setg(errp, "host/port/path and a file name may not be specified "
"at the same time");
return;
}
if (strstr(filename, "://")) {
int ret = nbd_parse_uri(filename, options);
if (ret < 0) {
error_setg(errp, "No valid URL specified");
}
return;
}
file = g_strdup(filename);
export_name = strstr(file, EN_OPTSTR);
if (export_name) {
if (export_name[strlen(EN_OPTSTR)] == 0) {
goto out;
}
export_name[0] = 0; /* truncate 'file' */
export_name += strlen(EN_OPTSTR);
qdict_put(options, "export", qstring_from_str(export_name));
}
/* extract the host_spec - fail if it's not nbd:... */
if (!strstart(file, "nbd:", &host_spec)) {
error_setg(errp, "File name string for NBD must start with 'nbd:'");
goto out;
}
if (!*host_spec) {
goto out;
}
/* are we a UNIX or TCP socket? */
if (strstart(host_spec, "unix:", &unixpath)) {
qdict_put(options, "path", qstring_from_str(unixpath));
} else {
InetSocketAddress *addr = NULL;
addr = inet_parse(host_spec, errp);
if (!addr) {
goto out;
}
qdict_put(options, "host", qstring_from_str(addr->host));
qdict_put(options, "port", qstring_from_str(addr->port));
qapi_free_InetSocketAddress(addr);
}
out:
g_free(file);
}
static void nbd_config(BDRVNBDState *s, QDict *options, char **export,
Error **errp)
{
Error *local_err = NULL;
if (qdict_haskey(options, "path") == qdict_haskey(options, "host")) {
if (qdict_haskey(options, "path")) {
error_setg(errp, "path and host may not be used at the same time.");
} else {
error_setg(errp, "one of path and host must be specified.");
}
return;
}
s->client.is_unix = qdict_haskey(options, "path");
s->socket_opts = qemu_opts_create(&socket_optslist, NULL, 0,
&error_abort);
qemu_opts_absorb_qdict(s->socket_opts, options, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (!qemu_opt_get(s->socket_opts, "port")) {
qemu_opt_set_number(s->socket_opts, "port", NBD_DEFAULT_PORT,
&error_abort);
}
*export = g_strdup(qdict_get_try_str(options, "export"));
if (*export) {
qdict_del(options, "export");
}
}
NbdClientSession *nbd_get_client_session(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
return &s->client;
}
static int nbd_establish_connection(BlockDriverState *bs, Error **errp)
{
BDRVNBDState *s = bs->opaque;
int sock;
if (s->client.is_unix) {
sock = unix_connect_opts(s->socket_opts, errp, NULL, NULL);
} else {
sock = inet_connect_opts(s->socket_opts, errp, NULL, NULL);
if (sock >= 0) {
socket_set_nodelay(sock);
}
}
/* Failed to establish connection */
if (sock < 0) {
logout("Failed to establish connection to NBD server\n");
return -errno;
}
return sock;
}
static int nbd_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVNBDState *s = bs->opaque;
char *export = NULL;
int result, sock;
Error *local_err = NULL;
/* Pop the config into our state object. Exit if invalid. */
nbd_config(s, options, &export, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return -EINVAL;
}
/* establish TCP connection, return error if it fails
* TODO: Configurable retry-until-timeout behaviour.
*/
sock = nbd_establish_connection(bs, errp);
if (sock < 0) {
return sock;
}
/* NBD handshake */
result = nbd_client_init(bs, sock, export, errp);
g_free(export);
return result;
}
static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
return nbd_client_co_readv(bs, sector_num, nb_sectors, qiov);
}
static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
return nbd_client_co_writev(bs, sector_num, nb_sectors, qiov);
}
static int nbd_co_flush(BlockDriverState *bs)
{
return nbd_client_co_flush(bs);
}
static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
{
bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
}
static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
int nb_sectors)
{
return nbd_client_co_discard(bs, sector_num, nb_sectors);
}
static void nbd_close(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
qemu_opts_del(s->socket_opts);
nbd_client_close(bs);
}
static int64_t nbd_getlength(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
return s->client.size;
}
static void nbd_detach_aio_context(BlockDriverState *bs)
{
nbd_client_detach_aio_context(bs);
}
static void nbd_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
nbd_client_attach_aio_context(bs, new_context);
}
static void nbd_refresh_filename(BlockDriverState *bs)
{
QDict *opts = qdict_new();
const char *path = qdict_get_try_str(bs->options, "path");
const char *host = qdict_get_try_str(bs->options, "host");
const char *port = qdict_get_try_str(bs->options, "port");
const char *export = qdict_get_try_str(bs->options, "export");
qdict_put_obj(opts, "driver", QOBJECT(qstring_from_str("nbd")));
if (path && export) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd+unix:///%s?socket=%s", export, path);
} else if (path && !export) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd+unix://?socket=%s", path);
} else if (!path && export && port) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd://%s:%s/%s", host, port, export);
} else if (!path && export && !port) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd://%s/%s", host, export);
} else if (!path && !export && port) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd://%s:%s", host, port);
} else if (!path && !export && !port) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"nbd://%s", host);
}
if (path) {
qdict_put_obj(opts, "path", QOBJECT(qstring_from_str(path)));
} else if (port) {
qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
qdict_put_obj(opts, "port", QOBJECT(qstring_from_str(port)));
} else {
qdict_put_obj(opts, "host", QOBJECT(qstring_from_str(host)));
}
if (export) {
qdict_put_obj(opts, "export", QOBJECT(qstring_from_str(export)));
}
bs->full_open_options = opts;
}
static BlockDriver bdrv_nbd = {
.format_name = "nbd",
.protocol_name = "nbd",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
.bdrv_file_open = nbd_open,
.bdrv_co_readv = nbd_co_readv,
.bdrv_co_writev = nbd_co_writev,
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
};
static BlockDriver bdrv_nbd_tcp = {
.format_name = "nbd",
.protocol_name = "nbd+tcp",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
.bdrv_file_open = nbd_open,
.bdrv_co_readv = nbd_co_readv,
.bdrv_co_writev = nbd_co_writev,
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
};
static BlockDriver bdrv_nbd_unix = {
.format_name = "nbd",
.protocol_name = "nbd+unix",
.instance_size = sizeof(BDRVNBDState),
.bdrv_parse_filename = nbd_parse_filename,
.bdrv_file_open = nbd_open,
.bdrv_co_readv = nbd_co_readv,
.bdrv_co_writev = nbd_co_writev,
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
};
static void bdrv_nbd_init(void)
{
bdrv_register(&bdrv_nbd);
bdrv_register(&bdrv_nbd_tcp);
bdrv_register(&bdrv_nbd_unix);
}
block_init(bdrv_nbd_init);