Merge branch 'upstream-merge'
[qemu-kvm/markmc.git] / qemu-nbd.c
blob6cdb83473f9f215578d5ea61374a1075a389bee6
1 /*
2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
4 * Network Block Device
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; under version 2 of the License.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include <qemu-common.h>
20 #include "block_int.h"
21 #include "nbd.h"
23 #include <stdarg.h>
24 #include <stdio.h>
25 #include <getopt.h>
26 #include <err.h>
27 #include <sys/types.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30 #include <netinet/tcp.h>
31 #include <arpa/inet.h>
32 #include <signal.h>
34 #define SOCKET_PATH "/var/lock/qemu-nbd-%s"
36 #define NBD_BUFFER_SIZE (1024*1024)
38 static int verbose;
40 static void usage(const char *name)
42 printf(
43 "Usage: %s [OPTIONS] FILE\n"
44 "QEMU Disk Network Block Device Server\n"
45 "\n"
46 " -p, --port=PORT port to listen on (default `1024')\n"
47 " -o, --offset=OFFSET offset into the image\n"
48 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
49 " -k, --socket=PATH path to the unix socket\n"
50 " (default '"SOCKET_PATH"')\n"
51 " -r, --read-only export read-only\n"
52 " -P, --partition=NUM only expose partition NUM\n"
53 " -s, --snapshot use snapshot file\n"
54 " -n, --nocache disable host cache\n"
55 " -c, --connect=DEV connect FILE to the local NBD device DEV\n"
56 " -d, --disconnect disconnect the specified device\n"
57 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
58 " -t, --persistent don't exit on the last connection\n"
59 " -v, --verbose display extra debugging information\n"
60 " -h, --help display this help and exit\n"
61 " -V, --version output version information and exit\n"
62 "\n"
63 "Report bugs to <anthony@codemonkey.ws>\n"
64 , name, "DEVICE");
67 static void version(const char *name)
69 printf(
70 "%s version 0.0.1\n"
71 "Written by Anthony Liguori.\n"
72 "\n"
73 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
74 "This is free software; see the source for copying conditions. There is NO\n"
75 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
76 , name);
79 struct partition_record
81 uint8_t bootable;
82 uint8_t start_head;
83 uint32_t start_cylinder;
84 uint8_t start_sector;
85 uint8_t system;
86 uint8_t end_head;
87 uint8_t end_cylinder;
88 uint8_t end_sector;
89 uint32_t start_sector_abs;
90 uint32_t nb_sectors_abs;
93 static void read_partition(uint8_t *p, struct partition_record *r)
95 r->bootable = p[0];
96 r->start_head = p[1];
97 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
98 r->start_sector = p[2] & 0x3f;
99 r->system = p[4];
100 r->end_head = p[5];
101 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
102 r->end_sector = p[6] & 0x3f;
103 r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
104 r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
107 static int find_partition(BlockDriverState *bs, int partition,
108 off_t *offset, off_t *size)
110 struct partition_record mbr[4];
111 uint8_t data[512];
112 int i;
113 int ext_partnum = 4;
115 if (bdrv_read(bs, 0, data, 1))
116 errx(EINVAL, "error while reading");
118 if (data[510] != 0x55 || data[511] != 0xaa) {
119 errno = -EINVAL;
120 return -1;
123 for (i = 0; i < 4; i++) {
124 read_partition(&data[446 + 16 * i], &mbr[i]);
126 if (!mbr[i].nb_sectors_abs)
127 continue;
129 if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
130 struct partition_record ext[4];
131 uint8_t data1[512];
132 int j;
134 if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1))
135 errx(EINVAL, "error while reading");
137 for (j = 0; j < 4; j++) {
138 read_partition(&data1[446 + 16 * j], &ext[j]);
139 if (!ext[j].nb_sectors_abs)
140 continue;
142 if ((ext_partnum + j + 1) == partition) {
143 *offset = (uint64_t)ext[j].start_sector_abs << 9;
144 *size = (uint64_t)ext[j].nb_sectors_abs << 9;
145 return 0;
148 ext_partnum += 4;
149 } else if ((i + 1) == partition) {
150 *offset = (uint64_t)mbr[i].start_sector_abs << 9;
151 *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
152 return 0;
156 errno = -ENOENT;
157 return -1;
160 static void show_parts(const char *device)
162 if (fork() == 0) {
163 int nbd;
165 /* linux just needs an open() to trigger
166 * the partition table update
167 * but remember to load the module with max_part != 0 :
168 * modprobe nbd max_part=63
170 nbd = open(device, O_RDWR);
171 if (nbd != -1)
172 close(nbd);
173 exit(0);
177 int main(int argc, char **argv)
179 BlockDriverState *bs;
180 off_t dev_offset = 0;
181 off_t offset = 0;
182 bool readonly = false;
183 bool disconnect = false;
184 const char *bindto = "0.0.0.0";
185 int port = 1024;
186 struct sockaddr_in addr;
187 socklen_t addr_len = sizeof(addr);
188 off_t fd_size;
189 char *device = NULL;
190 char *socket = NULL;
191 char sockpath[128];
192 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
193 struct option lopt[] = {
194 { "help", 0, NULL, 'h' },
195 { "version", 0, NULL, 'V' },
196 { "bind", 1, NULL, 'b' },
197 { "port", 1, NULL, 'p' },
198 { "socket", 1, NULL, 'k' },
199 { "offset", 1, NULL, 'o' },
200 { "read-only", 0, NULL, 'r' },
201 { "partition", 1, NULL, 'P' },
202 { "connect", 1, NULL, 'c' },
203 { "disconnect", 0, NULL, 'd' },
204 { "snapshot", 0, NULL, 's' },
205 { "nocache", 0, NULL, 'n' },
206 { "shared", 1, NULL, 'e' },
207 { "persistent", 0, NULL, 't' },
208 { "verbose", 0, NULL, 'v' },
209 { NULL, 0, NULL, 0 }
211 int ch;
212 int opt_ind = 0;
213 int li;
214 char *end;
215 int flags = 0;
216 int partition = -1;
217 int ret;
218 int shared = 1;
219 uint8_t *data;
220 fd_set fds;
221 int *sharing_fds;
222 int fd;
223 int i;
224 int nb_fds = 0;
225 int max_fd;
226 int persistent = 0;
228 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
229 switch (ch) {
230 case 's':
231 flags |= BDRV_O_SNAPSHOT;
232 break;
233 case 'n':
234 flags |= BDRV_O_NOCACHE;
235 break;
236 case 'b':
237 bindto = optarg;
238 break;
239 case 'p':
240 li = strtol(optarg, &end, 0);
241 if (*end) {
242 errx(EINVAL, "Invalid port `%s'", optarg);
244 if (li < 1 || li > 65535) {
245 errx(EINVAL, "Port out of range `%s'", optarg);
247 port = (uint16_t)li;
248 break;
249 case 'o':
250 dev_offset = strtoll (optarg, &end, 0);
251 if (*end) {
252 errx(EINVAL, "Invalid offset `%s'", optarg);
254 if (dev_offset < 0) {
255 errx(EINVAL, "Offset must be positive `%s'", optarg);
257 break;
258 case 'r':
259 readonly = true;
260 break;
261 case 'P':
262 partition = strtol(optarg, &end, 0);
263 if (*end)
264 errx(EINVAL, "Invalid partition `%s'", optarg);
265 if (partition < 1 || partition > 8)
266 errx(EINVAL, "Invalid partition %d", partition);
267 break;
268 case 'k':
269 socket = optarg;
270 if (socket[0] != '/')
271 errx(EINVAL, "socket path must be absolute\n");
272 break;
273 case 'd':
274 disconnect = true;
275 break;
276 case 'c':
277 device = optarg;
278 break;
279 case 'e':
280 shared = strtol(optarg, &end, 0);
281 if (*end) {
282 errx(EINVAL, "Invalid shared device number '%s'", optarg);
284 if (shared < 1) {
285 errx(EINVAL, "Shared device number must be greater than 0\n");
287 break;
288 case 't':
289 persistent = 1;
290 break;
291 case 'v':
292 verbose = 1;
293 break;
294 case 'V':
295 version(argv[0]);
296 exit(0);
297 break;
298 case 'h':
299 usage(argv[0]);
300 exit(0);
301 break;
302 case '?':
303 errx(EINVAL, "Try `%s --help' for more information.",
304 argv[0]);
308 if ((argc - optind) != 1) {
309 errx(EINVAL, "Invalid number of argument.\n"
310 "Try `%s --help' for more information.",
311 argv[0]);
314 if (disconnect) {
315 fd = open(argv[optind], O_RDWR);
316 if (fd == -1)
317 errx(errno, "Cannot open %s", argv[optind]);
319 nbd_disconnect(fd);
321 close(fd);
323 printf("%s disconnected\n", argv[optind]);
325 return 0;
328 bdrv_init();
330 bs = bdrv_new("hda");
331 if (bs == NULL)
332 return 1;
334 if (bdrv_open(bs, argv[optind], flags) == -1)
335 return 1;
337 fd_size = bs->total_sectors * 512;
339 if (partition != -1 &&
340 find_partition(bs, partition, &dev_offset, &fd_size))
341 errx(errno, "Could not find partition %d", partition);
343 if (device) {
344 pid_t pid;
345 int sock;
347 if (!verbose) {
348 /* detach client and server */
349 if (daemon(0, 0) == -1) {
350 errx(errno, "Failed to daemonize");
354 if (socket == NULL) {
355 sprintf(sockpath, SOCKET_PATH, basename(device));
356 socket = sockpath;
359 pid = fork();
360 if (pid < 0)
361 return 1;
362 if (pid != 0) {
363 off_t size;
364 size_t blocksize;
366 ret = 0;
367 bdrv_close(bs);
369 do {
370 sock = unix_socket_outgoing(socket);
371 if (sock == -1) {
372 if (errno != ENOENT && errno != ECONNREFUSED)
373 goto out;
374 sleep(1); /* wait children */
376 } while (sock == -1);
378 fd = open(device, O_RDWR);
379 if (fd == -1) {
380 ret = 1;
381 goto out;
384 ret = nbd_receive_negotiate(sock, &size, &blocksize);
385 if (ret == -1) {
386 ret = 1;
387 goto out;
390 ret = nbd_init(fd, sock, size, blocksize);
391 if (ret == -1) {
392 ret = 1;
393 goto out;
396 printf("NBD device %s is now connected to file %s\n",
397 device, argv[optind]);
399 /* update partition table */
401 show_parts(device);
403 nbd_client(fd, sock);
404 close(fd);
405 out:
406 kill(pid, SIGTERM);
407 unlink(socket);
409 return ret;
411 /* children */
414 sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
416 if (socket) {
417 sharing_fds[0] = unix_socket_incoming(socket);
418 } else {
419 sharing_fds[0] = tcp_socket_incoming(bindto, port);
422 if (sharing_fds[0] == -1)
423 return 1;
424 max_fd = sharing_fds[0];
425 nb_fds++;
427 data = qemu_memalign(512, NBD_BUFFER_SIZE);
428 if (data == NULL)
429 errx(ENOMEM, "Cannot allocate data buffer");
431 do {
433 FD_ZERO(&fds);
434 for (i = 0; i < nb_fds; i++)
435 FD_SET(sharing_fds[i], &fds);
437 ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
438 if (ret == -1)
439 break;
441 if (FD_ISSET(sharing_fds[0], &fds))
442 ret--;
443 for (i = 1; i < nb_fds && ret; i++) {
444 if (FD_ISSET(sharing_fds[i], &fds)) {
445 if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
446 &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
447 close(sharing_fds[i]);
448 nb_fds--;
449 sharing_fds[i] = sharing_fds[nb_fds];
450 i--;
452 ret--;
455 /* new connection ? */
456 if (FD_ISSET(sharing_fds[0], &fds)) {
457 if (nb_fds < shared + 1) {
458 sharing_fds[nb_fds] = accept(sharing_fds[0],
459 (struct sockaddr *)&addr,
460 &addr_len);
461 if (sharing_fds[nb_fds] != -1 &&
462 nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) {
463 if (sharing_fds[nb_fds] > max_fd)
464 max_fd = sharing_fds[nb_fds];
465 nb_fds++;
469 } while (persistent || nb_fds > 1);
470 qemu_free(data);
472 close(sharing_fds[0]);
473 bdrv_close(bs);
474 qemu_free(sharing_fds);
475 if (socket)
476 unlink(socket);
478 return 0;