aboutsummaryrefslogtreecommitdiff
path: root/block/nbd.c
blob: 697c0219b4477eb141a77c75a2eb0b4aca732900 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
/*
 * 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);