Archipelago » qemu

/*

 * 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/qjson.h"

#include "qapi/qmp/qint.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 (error_is_set(errp)) {

            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 int nbd_config(BDRVNBDState *s, QDict *options, char **export)

{

    Error *local_err = NULL;

    if (qdict_haskey(options, "path")) {

        if (qdict_haskey(options, "host")) {

            qerror_report(ERROR_CLASS_GENERIC_ERROR, "path and host may not "

                          "be used at the same time.");

            return -EINVAL;

        }

        s->client.is_unix = true;

    } else if (qdict_haskey(options, "host")) {

        s->client.is_unix = false;

    } else {

        return -EINVAL;

    }

    s->socket_opts = qemu_opts_create(&socket_optslist, NULL, 0,

                                      &error_abort);

    qemu_opts_absorb_qdict(s->socket_opts, options, &local_err);

    if (error_is_set(&local_err)) {

        qerror_report_err(local_err);

        error_free(local_err);

        return -EINVAL;

    }

    if (!qemu_opt_get(s->socket_opts, "port")) {

        qemu_opt_set_number(s->socket_opts, "port", NBD_DEFAULT_PORT);

    }

    *export = g_strdup(qdict_get_try_str(options, "export"));

    if (*export) {

        qdict_del(options, "export");

    }

    return 0;

}

static int nbd_establish_connection(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    int sock;

    if (s->client.is_unix) {

        sock = unix_socket_outgoing(qemu_opt_get(s->socket_opts, "path"));

    } else {

        sock = tcp_socket_outgoing_opts(s->socket_opts);

        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;

    /* Pop the config into our state object. Exit if invalid. */

    result = nbd_config(s, options, &export);

    if (result != 0) {

        return result;

    }

    /* establish TCP connection, return error if it fails

     * TODO: Configurable retry-until-timeout behaviour.

     */

    sock = nbd_establish_connection(bs);

    if (sock < 0) {

        return sock;

    }

    /* NBD handshake */

    result = nbd_client_session_init(&s->client, bs, sock, export);

    g_free(export);

    return result;

}

static int nbd_co_readv(BlockDriverState *bs, int64_t sector_num,

                        int nb_sectors, QEMUIOVector *qiov)

{

    BDRVNBDState *s = bs->opaque;

    return nbd_client_session_co_readv(&s->client, sector_num,

                                       nb_sectors, qiov);

}

static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,

                         int nb_sectors, QEMUIOVector *qiov)

{

    BDRVNBDState *s = bs->opaque;

    return nbd_client_session_co_writev(&s->client, sector_num,

                                        nb_sectors, qiov);

}

static int nbd_co_flush(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    return nbd_client_session_co_flush(&s->client);

}

static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,

                          int nb_sectors)

{

    BDRVNBDState *s = bs->opaque;

    return nbd_client_session_co_discard(&s->client, sector_num,

                                         nb_sectors);

}

static void nbd_close(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    qemu_opts_del(s->socket_opts);

    nbd_client_session_close(&s->client);

}

static int64_t nbd_getlength(BlockDriverState *bs)

{

    BDRVNBDState *s = bs->opaque;

    return s->client.size;

}

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_getlength      = nbd_getlength,

};

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_getlength      = nbd_getlength,

};

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_getlength      = nbd_getlength,

};

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);