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19#include <qemu-common.h>
20#include "block_int.h"
21#include "nbd.h"
22
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>
33#include <libgen.h>
34
35#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
36
37#define NBD_BUFFER_SIZE (1024*1024)
38
39static int verbose;
40
41static void usage(const char *name)
42{
43 printf(
44"Usage: %s [OPTIONS] FILE\n"
45"QEMU Disk Network Block Device Server\n"
46"\n"
47" -p, --port=PORT port to listen on (default `%d')\n"
48" -o, --offset=OFFSET offset into the image\n"
49" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
50" -k, --socket=PATH path to the unix socket\n"
51" (default '"SOCKET_PATH"')\n"
52" -r, --read-only export read-only\n"
53" -P, --partition=NUM only expose partition NUM\n"
54" -s, --snapshot use snapshot file\n"
55" -n, --nocache disable host cache\n"
56" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
57" -d, --disconnect disconnect the specified device\n"
58" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
59" -t, --persistent don't exit on the last connection\n"
60" -v, --verbose display extra debugging information\n"
61" -h, --help display this help and exit\n"
62" -V, --version output version information and exit\n"
63"\n"
64"Report bugs to <anthony@codemonkey.ws>\n"
65 , name, NBD_DEFAULT_PORT, "DEVICE");
66}
67
68static void version(const char *name)
69{
70 printf(
71"%s version 0.0.1\n"
72"Written by Anthony Liguori.\n"
73"\n"
74"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
75"This is free software; see the source for copying conditions. There is NO\n"
76"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
77 , name);
78}
79
80struct partition_record
81{
82 uint8_t bootable;
83 uint8_t start_head;
84 uint32_t start_cylinder;
85 uint8_t start_sector;
86 uint8_t system;
87 uint8_t end_head;
88 uint8_t end_cylinder;
89 uint8_t end_sector;
90 uint32_t start_sector_abs;
91 uint32_t nb_sectors_abs;
92};
93
94static void read_partition(uint8_t *p, struct partition_record *r)
95{
96 r->bootable = p[0];
97 r->start_head = p[1];
98 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);
99 r->start_sector = p[2] & 0x3f;
100 r->system = p[4];
101 r->end_head = p[5];
102 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);
103 r->end_sector = p[6] & 0x3f;
104 r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
105 r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
106}
107
108static int find_partition(BlockDriverState *bs, int partition,
109 off_t *offset, off_t *size)
110{
111 struct partition_record mbr[4];
112 uint8_t data[512];
113 int i;
114 int ext_partnum = 4;
115 int ret;
116
117 if ((ret = bdrv_read(bs, 0, data, 1)) < 0) {
118 errno = -ret;
119 err(EXIT_FAILURE, "error while reading");
120 }
121
122 if (data[510] != 0x55 || data[511] != 0xaa) {
123 errno = -EINVAL;
124 return -1;
125 }
126
127 for (i = 0; i < 4; i++) {
128 read_partition(&data[446 + 16 * i], &mbr[i]);
129
130 if (!mbr[i].nb_sectors_abs)
131 continue;
132
133 if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
134 struct partition_record ext[4];
135 uint8_t data1[512];
136 int j;
137
138 if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) {
139 errno = -ret;
140 err(EXIT_FAILURE, "error while reading");
141 }
142
143 for (j = 0; j < 4; j++) {
144 read_partition(&data1[446 + 16 * j], &ext[j]);
145 if (!ext[j].nb_sectors_abs)
146 continue;
147
148 if ((ext_partnum + j + 1) == partition) {
149 *offset = (uint64_t)ext[j].start_sector_abs << 9;
150 *size = (uint64_t)ext[j].nb_sectors_abs << 9;
151 return 0;
152 }
153 }
154 ext_partnum += 4;
155 } else if ((i + 1) == partition) {
156 *offset = (uint64_t)mbr[i].start_sector_abs << 9;
157 *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
158 return 0;
159 }
160 }
161
162 errno = -ENOENT;
163 return -1;
164}
165
166static void show_parts(const char *device)
167{
168 if (fork() == 0) {
169 int nbd;
170
171
172
173
174
175
176 nbd = open(device, O_RDWR);
177 if (nbd != -1)
178 close(nbd);
179 exit(0);
180 }
181}
182
183int main(int argc, char **argv)
184{
185 BlockDriverState *bs;
186 off_t dev_offset = 0;
187 off_t offset = 0;
188 bool readonly = false;
189 bool disconnect = false;
190 const char *bindto = "0.0.0.0";
191 int port = NBD_DEFAULT_PORT;
192 struct sockaddr_in addr;
193 socklen_t addr_len = sizeof(addr);
194 off_t fd_size;
195 char *device = NULL;
196 char *socket = NULL;
197 char sockpath[128];
198 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
199 struct option lopt[] = {
200 { "help", 0, NULL, 'h' },
201 { "version", 0, NULL, 'V' },
202 { "bind", 1, NULL, 'b' },
203 { "port", 1, NULL, 'p' },
204 { "socket", 1, NULL, 'k' },
205 { "offset", 1, NULL, 'o' },
206 { "read-only", 0, NULL, 'r' },
207 { "partition", 1, NULL, 'P' },
208 { "connect", 1, NULL, 'c' },
209 { "disconnect", 0, NULL, 'd' },
210 { "snapshot", 0, NULL, 's' },
211 { "nocache", 0, NULL, 'n' },
212 { "shared", 1, NULL, 'e' },
213 { "persistent", 0, NULL, 't' },
214 { "verbose", 0, NULL, 'v' },
215 { NULL, 0, NULL, 0 }
216 };
217 int ch;
218 int opt_ind = 0;
219 int li;
220 char *end;
221 int flags = BDRV_O_RDWR;
222 int partition = -1;
223 int ret;
224 int shared = 1;
225 uint8_t *data;
226 fd_set fds;
227 int *sharing_fds;
228 int fd;
229 int i;
230 int nb_fds = 0;
231 int max_fd;
232 int persistent = 0;
233 uint32_t nbdflags;
234
235 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
236 switch (ch) {
237 case 's':
238 flags |= BDRV_O_SNAPSHOT;
239 break;
240 case 'n':
241 flags |= BDRV_O_NOCACHE;
242 break;
243 case 'b':
244 bindto = optarg;
245 break;
246 case 'p':
247 li = strtol(optarg, &end, 0);
248 if (*end) {
249 errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
250 }
251 if (li < 1 || li > 65535) {
252 errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
253 }
254 port = (uint16_t)li;
255 break;
256 case 'o':
257 dev_offset = strtoll (optarg, &end, 0);
258 if (*end) {
259 errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
260 }
261 if (dev_offset < 0) {
262 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
263 }
264 break;
265 case 'r':
266 readonly = true;
267 flags &= ~BDRV_O_RDWR;
268 break;
269 case 'P':
270 partition = strtol(optarg, &end, 0);
271 if (*end)
272 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
273 if (partition < 1 || partition > 8)
274 errx(EXIT_FAILURE, "Invalid partition %d", partition);
275 break;
276 case 'k':
277 socket = optarg;
278 if (socket[0] != '/')
279 errx(EXIT_FAILURE, "socket path must be absolute\n");
280 break;
281 case 'd':
282 disconnect = true;
283 break;
284 case 'c':
285 device = optarg;
286 break;
287 case 'e':
288 shared = strtol(optarg, &end, 0);
289 if (*end) {
290 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
291 }
292 if (shared < 1) {
293 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
294 }
295 break;
296 case 't':
297 persistent = 1;
298 break;
299 case 'v':
300 verbose = 1;
301 break;
302 case 'V':
303 version(argv[0]);
304 exit(0);
305 break;
306 case 'h':
307 usage(argv[0]);
308 exit(0);
309 break;
310 case '?':
311 errx(EXIT_FAILURE, "Try `%s --help' for more information.",
312 argv[0]);
313 }
314 }
315
316 if ((argc - optind) != 1) {
317 errx(EXIT_FAILURE, "Invalid number of argument.\n"
318 "Try `%s --help' for more information.",
319 argv[0]);
320 }
321
322 if (disconnect) {
323 fd = open(argv[optind], O_RDWR);
324 if (fd == -1)
325 err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
326
327 nbd_disconnect(fd);
328
329 close(fd);
330
331 printf("%s disconnected\n", argv[optind]);
332
333 return 0;
334 }
335
336 bdrv_init();
337
338 bs = bdrv_new("hda");
339
340 if ((ret = bdrv_open(bs, argv[optind], flags, NULL)) < 0) {
341 errno = -ret;
342 err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
343 }
344
345 fd_size = bs->total_sectors * 512;
346
347 if (partition != -1 &&
348 find_partition(bs, partition, &dev_offset, &fd_size))
349 err(EXIT_FAILURE, "Could not find partition %d", partition);
350
351 if (device) {
352 pid_t pid;
353 int sock;
354
355
356 if (access(device, R_OK|W_OK) == -1) {
357 err(EXIT_FAILURE, "Could not access '%s'", device);
358 }
359
360 if (!verbose) {
361
362 if (daemon(0, 0) == -1) {
363 err(EXIT_FAILURE, "Failed to daemonize");
364 }
365 }
366
367 if (socket == NULL) {
368 snprintf(sockpath, sizeof(sockpath), SOCKET_PATH,
369 basename(device));
370 socket = sockpath;
371 }
372
373 pid = fork();
374 if (pid < 0)
375 return 1;
376 if (pid != 0) {
377 off_t size;
378 size_t blocksize;
379
380 ret = 0;
381 bdrv_close(bs);
382
383 do {
384 sock = unix_socket_outgoing(socket);
385 if (sock == -1) {
386 if (errno != ENOENT && errno != ECONNREFUSED) {
387 ret = 1;
388 goto out;
389 }
390 sleep(1);
391 }
392 } while (sock == -1);
393
394 fd = open(device, O_RDWR);
395 if (fd == -1) {
396 ret = 1;
397 goto out;
398 }
399
400 ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
401 &size, &blocksize);
402 if (ret == -1) {
403 ret = 1;
404 goto out;
405 }
406
407 ret = nbd_init(fd, sock, size, blocksize);
408 if (ret == -1) {
409 ret = 1;
410 goto out;
411 }
412
413 printf("NBD device %s is now connected to file %s\n",
414 device, argv[optind]);
415
416
417
418 show_parts(device);
419
420 ret = nbd_client(fd);
421 if (ret) {
422 ret = 1;
423 }
424 close(fd);
425 out:
426 kill(pid, SIGTERM);
427 unlink(socket);
428
429 return ret;
430 }
431
432 }
433
434 sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
435
436 if (socket) {
437 sharing_fds[0] = unix_socket_incoming(socket);
438 } else {
439 sharing_fds[0] = tcp_socket_incoming(bindto, port);
440 }
441
442 if (sharing_fds[0] == -1)
443 return 1;
444 max_fd = sharing_fds[0];
445 nb_fds++;
446
447 data = qemu_blockalign(bs, NBD_BUFFER_SIZE);
448 if (data == NULL)
449 errx(EXIT_FAILURE, "Cannot allocate data buffer");
450
451 do {
452
453 FD_ZERO(&fds);
454 for (i = 0; i < nb_fds; i++)
455 FD_SET(sharing_fds[i], &fds);
456
457 ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
458 if (ret == -1)
459 break;
460
461 if (FD_ISSET(sharing_fds[0], &fds))
462 ret--;
463 for (i = 1; i < nb_fds && ret; i++) {
464 if (FD_ISSET(sharing_fds[i], &fds)) {
465 if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
466 &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
467 close(sharing_fds[i]);
468 nb_fds--;
469 sharing_fds[i] = sharing_fds[nb_fds];
470 i--;
471 }
472 ret--;
473 }
474 }
475
476 if (FD_ISSET(sharing_fds[0], &fds)) {
477 if (nb_fds < shared + 1) {
478 sharing_fds[nb_fds] = accept(sharing_fds[0],
479 (struct sockaddr *)&addr,
480 &addr_len);
481 if (sharing_fds[nb_fds] != -1 &&
482 nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) {
483 if (sharing_fds[nb_fds] > max_fd)
484 max_fd = sharing_fds[nb_fds];
485 nb_fds++;
486 }
487 }
488 }
489 } while (persistent || nb_fds > 1);
490 qemu_vfree(data);
491
492 close(sharing_fds[0]);
493 bdrv_close(bs);
494 qemu_free(sharing_fds);
495 if (socket)
496 unlink(socket);
497
498 return 0;
499}
500
