summaryrefslogtreecommitdiff
blob: 605d4e324bd1e27b2a2c68fcba6d9928bdfbac57 (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
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
/*
 *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
 *
 *  Network Block Device
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; under version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <qemu-common.h>
#include "block_int.h"
#include "nbd.h"

#include <stdarg.h>
#include <stdio.h>
#include <getopt.h>
#include <err.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <signal.h>

#define SOCKET_PATH    "/var/lock/qemu-nbd-%s"

#define NBD_BUFFER_SIZE (1024*1024)

int verbose;

static void usage(const char *name)
{
    printf(
"Usage: %s [OPTIONS] FILE\n"
"QEMU Disk Network Block Device Server\n"
"\n"
"  -p, --port=PORT      port to listen on (default `1024')\n"
"  -o, --offset=OFFSET  offset into the image\n"
"  -b, --bind=IFACE     interface to bind to (default `0.0.0.0')\n"
"  -k, --socket=PATH    path to the unix socket\n"
"                       (default '"SOCKET_PATH"')\n"
"  -r, --read-only      export read-only\n"
"  -P, --partition=NUM  only expose partition NUM\n"
"  -s, --snapshot       use snapshot file\n"
"  -n, --nocache        disable host cache\n"
"  -c, --connect=DEV    connect FILE to the local NBD device DEV\n"
"  -d, --disconnect     disconnect the specified device\n"
"  -e, --shared=NUM     device can be shared by NUM clients (default '1')\n"
"  -v, --verbose        display extra debugging information\n"
"  -h, --help           display this help and exit\n"
"  -V, --version        output version information and exit\n"
"\n"
"Report bugs to <anthony@codemonkey.ws>\n"
    , name, "DEVICE");
}

static void version(const char *name)
{
    printf(
"qemu-nbd version 0.0.1\n"
"Written by Anthony Liguori.\n"
"\n"
"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
"This is free software; see the source for copying conditions.  There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
    );
}

struct partition_record
{
    uint8_t bootable;
    uint8_t start_head;
    uint32_t start_cylinder;
    uint8_t start_sector;
    uint8_t system;
    uint8_t end_head;
    uint8_t end_cylinder;
    uint8_t end_sector;
    uint32_t start_sector_abs;
    uint32_t nb_sectors_abs;
};

static void read_partition(uint8_t *p, struct partition_record *r)
{
    r->bootable = p[0];
    r->start_head = p[1];
    r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
    r->start_sector = p[2] & 0x3f;
    r->system = p[4];
    r->end_head = p[5];
    r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
    r->end_sector = p[6] & 0x3f;
    r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
    r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
}

static int find_partition(BlockDriverState *bs, int partition,
                          off_t *offset, off_t *size)
{
    struct partition_record mbr[4];
    uint8_t data[512];
    int i;
    int ext_partnum = 4;

    if (bdrv_read(bs, 0, data, 1))
        errx(EINVAL, "error while reading");

    if (data[510] != 0x55 || data[511] != 0xaa) {
        errno = -EINVAL;
        return -1;
    }

    for (i = 0; i < 4; i++) {
        read_partition(&data[446 + 16 * i], &mbr[i]);

        if (!mbr[i].nb_sectors_abs)
            continue;

        if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
            struct partition_record ext[4];
            uint8_t data1[512];
            int j;

            if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1))
                errx(EINVAL, "error while reading");

            for (j = 0; j < 4; j++) {
                read_partition(&data1[446 + 16 * j], &ext[j]);
                if (!ext[j].nb_sectors_abs)
                    continue;

                if ((ext_partnum + j + 1) == partition) {
                    *offset = (uint64_t)ext[j].start_sector_abs << 9;
                    *size = (uint64_t)ext[j].nb_sectors_abs << 9;
                    return 0;
                }
            }
            ext_partnum += 4;
        } else if ((i + 1) == partition) {
            *offset = (uint64_t)mbr[i].start_sector_abs << 9;
            *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
            return 0;
        }
    }

    errno = -ENOENT;
    return -1;
}

static void show_parts(const char *device)
{
    if (fork() == 0) {
        int nbd;

        /* linux just needs an open() to trigger
         * the partition table update
         * but remember to load the module with max_part != 0 :
         *     modprobe nbd max_part=63
         */
        nbd = open(device, O_RDWR);
        if (nbd != -1)
              close(nbd);
        exit(0);
    }
}

int main(int argc, char **argv)
{
    BlockDriverState *bs;
    off_t dev_offset = 0;
    off_t offset = 0;
    bool readonly = false;
    bool disconnect = false;
    const char *bindto = "0.0.0.0";
    int port = 1024;
    struct sockaddr_in addr;
    socklen_t addr_len = sizeof(addr);
    off_t fd_size;
    char *device = NULL;
    char *socket = NULL;
    char sockpath[128];
    const char *sopt = "hVbo:p:rsnP:c:dvk:e:";
    struct option lopt[] = {
        { "help", 0, 0, 'h' },
        { "version", 0, 0, 'V' },
        { "bind", 1, 0, 'b' },
        { "port", 1, 0, 'p' },
        { "socket", 1, 0, 'k' },
        { "offset", 1, 0, 'o' },
        { "read-only", 0, 0, 'r' },
        { "partition", 1, 0, 'P' },
        { "connect", 1, 0, 'c' },
        { "disconnect", 0, 0, 'd' },
        { "snapshot", 0, 0, 's' },
        { "nocache", 0, 0, 'n' },
        { "shared", 1, 0, 'e' },
        { "verbose", 0, 0, 'v' },
        { NULL, 0, 0, 0 }
    };
    int ch;
    int opt_ind = 0;
    int li;
    char *end;
    int flags = 0;
    int partition = -1;
    int ret;
    int shared = 1;
    uint8_t *data;
    fd_set fds;
    int *sharing_fds;
    int fd;
    int i;
    int nb_fds = 0;
    int max_fd;

    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
        switch (ch) {
        case 's':
            flags |= BDRV_O_SNAPSHOT;
            break;
        case 'n':
            flags |= BDRV_O_DIRECT;
            break;
        case 'b':
            bindto = optarg;
            break;
        case 'p':
            li = strtol(optarg, &end, 0);
            if (*end) {
                errx(EINVAL, "Invalid port `%s'", optarg);
            }
            if (li < 1 || li > 65535) {
                errx(EINVAL, "Port out of range `%s'", optarg);
            }
            port = (uint16_t)li;
            break;
        case 'o':
                dev_offset = strtoll (optarg, &end, 0);
            if (*end) {
                errx(EINVAL, "Invalid offset `%s'", optarg);
            }
            if (dev_offset < 0) {
                errx(EINVAL, "Offset must be positive `%s'", optarg);
            }
            break;
        case 'r':
            readonly = true;
            break;
        case 'P':
            partition = strtol(optarg, &end, 0);
            if (*end)
                errx(EINVAL, "Invalid partition `%s'", optarg);
            if (partition < 1 || partition > 8)
                errx(EINVAL, "Invalid partition %d", partition);
            break;
        case 'k':
            socket = optarg;
            if (socket[0] != '/')
                errx(EINVAL, "socket path must be absolute\n");
            break;
        case 'd':
            disconnect = true;
            break;
        case 'c':
            device = optarg;
            break;
        case 'e':
            shared = strtol(optarg, &end, 0);
            if (*end) {
                errx(EINVAL, "Invalid shared device number '%s'", optarg);
            }
            if (shared < 1) {
                errx(EINVAL, "Shared device number must be greater than 0\n");
            }
            break;
        case 'v':
            verbose = 1;
            break;
        case 'V':
            version(argv[0]);
            exit(0);
            break;
        case 'h':
            usage(argv[0]);
            exit(0);
            break;
        case '?':
            errx(EINVAL, "Try `%s --help' for more information.",
                 argv[0]);
        }
    }

    if ((argc - optind) != 1) {
        errx(EINVAL, "Invalid number of argument.\n"
             "Try `%s --help' for more information.",
             argv[0]);
    }

    if (disconnect) {
        fd = open(argv[optind], O_RDWR);
        if (fd == -1)
            errx(errno, "Cannot open %s", argv[optind]);

        nbd_disconnect(fd);

        close(fd);

        printf("%s disconnected\n", argv[optind]);

	return 0;
    }

    bdrv_init();

    bs = bdrv_new("hda");
    if (bs == NULL)
        return 1;

    if (bdrv_open(bs, argv[optind], flags) == -1)
        return 1;

    fd_size = bs->total_sectors * 512;

    if (partition != -1 &&
        find_partition(bs, partition, &dev_offset, &fd_size))
        errx(errno, "Could not find partition %d", partition);

    if (device) {
        pid_t pid;
        int sock;

        if (!verbose)
            daemon(0, 0);	/* detach client and server */

        if (socket == NULL) {
            sprintf(sockpath, SOCKET_PATH, basename(device));
            socket = sockpath;
        }

        pid = fork();
        if (pid < 0)
            return 1;
        if (pid != 0) {
            off_t size;
            size_t blocksize;

            ret = 0;
            bdrv_close(bs);

            do {
                sock = unix_socket_outgoing(socket);
                if (sock == -1) {
                    if (errno != ENOENT && errno != ECONNREFUSED)
                        goto out;
                    sleep(1);	/* wait children */
                }
            } while (sock == -1);

            fd = open(device, O_RDWR);
            if (fd == -1) {
                ret = 1;
                goto out;
            }

            ret = nbd_receive_negotiate(sock, &size, &blocksize);
            if (ret == -1) {
                ret = 1;
                goto out;
            }

            ret = nbd_init(fd, sock, size, blocksize);
            if (ret == -1) {
                ret = 1;
                goto out;
            }

            printf("NBD device %s is now connected to file %s\n",
                    device, argv[optind]);

	    /* update partition table */

            show_parts(device);

            nbd_client(fd, sock);
            close(fd);
 out:
            kill(pid, SIGTERM);
            unlink(socket);

            return ret;
        }
        /* children */
    }

    sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
    if (sharing_fds == NULL)
        errx(ENOMEM, "Cannot allocate sharing fds");

    if (socket) {
        sharing_fds[0] = unix_socket_incoming(socket);
    } else {
        sharing_fds[0] = tcp_socket_incoming(bindto, port);
    }

    if (sharing_fds[0] == -1)
        return 1;
    max_fd = sharing_fds[0];
    nb_fds++;

    data = qemu_memalign(512, NBD_BUFFER_SIZE);
    if (data == NULL)
        errx(ENOMEM, "Cannot allocate data buffer");

    do {

        FD_ZERO(&fds);
        for (i = 0; i < nb_fds; i++)
            FD_SET(sharing_fds[i], &fds);

        ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
        if (ret == -1)
            break;

        if (FD_ISSET(sharing_fds[0], &fds))
            ret--;
        for (i = 1; i < nb_fds && ret; i++) {
            if (FD_ISSET(sharing_fds[i], &fds)) {
                if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
                    &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
                    close(sharing_fds[i]);
                    nb_fds--;
                    sharing_fds[i] = sharing_fds[nb_fds];
                    i--;
                }
                ret--;
            }
        }
        /* new connection ? */
        if (FD_ISSET(sharing_fds[0], &fds)) {
            if (nb_fds < shared + 1) {
                sharing_fds[nb_fds] = accept(sharing_fds[0],
                                             (struct sockaddr *)&addr,
                                             &addr_len);
                if (sharing_fds[nb_fds] != -1 &&
                    nbd_negotiate(bs, sharing_fds[nb_fds], fd_size) != -1) {
                        if (sharing_fds[nb_fds] > max_fd)
                            max_fd = sharing_fds[nb_fds];
                        nb_fds++;
                }
            }
        }
    } while (nb_fds > 1);
    qemu_free(data);

    close(sharing_fds[0]);
    bdrv_close(bs);
    qemu_free(sharing_fds);
    if (socket)
        unlink(socket);

    return 0;
}