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/*
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu-common.h" |
20 |
#include "block_int.h" |
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#include "nbd.h" |
22 |
|
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#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 |
#include <pthread.h> |
35 |
|
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#define SOCKET_PATH "/var/lock/qemu-nbd-%s" |
37 |
|
38 |
#define NBD_BUFFER_SIZE (1024*1024) |
39 |
|
40 |
static int sigterm_wfd; |
41 |
static int verbose; |
42 |
static char *device; |
43 |
static char *srcpath; |
44 |
static char *sockpath; |
45 |
|
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static void usage(const char *name) |
47 |
{ |
48 |
printf( |
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"Usage: %s [OPTIONS] FILE\n"
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"QEMU Disk Network Block Device Server\n"
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"\n"
|
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" -p, --port=PORT port to listen on (default `%d')\n"
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" -o, --offset=OFFSET offset into the image\n"
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" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
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" -k, --socket=PATH path to the unix socket\n"
|
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" (default '"SOCKET_PATH"')\n" |
57 |
" -r, --read-only export read-only\n"
|
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" -P, --partition=NUM only expose partition NUM\n"
|
59 |
" -s, --snapshot use snapshot file\n"
|
60 |
" -n, --nocache disable host cache\n"
|
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" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
|
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" -d, --disconnect disconnect the specified device\n"
|
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" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
|
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" -t, --persistent don't exit on the last connection\n"
|
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" -v, --verbose display extra debugging information\n"
|
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" -h, --help display this help and exit\n"
|
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" -V, --version output version information and exit\n"
|
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"\n"
|
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"Report bugs to <anthony@codemonkey.ws>\n"
|
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, name, NBD_DEFAULT_PORT, "DEVICE");
|
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} |
72 |
|
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static void version(const char *name) |
74 |
{ |
75 |
printf( |
76 |
"%s version 0.0.1\n"
|
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"Written by Anthony Liguori.\n"
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"\n"
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"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
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"This is free software; see the source for copying conditions. There is NO\n"
|
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"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
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, name); |
83 |
} |
84 |
|
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struct partition_record
|
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{ |
87 |
uint8_t bootable; |
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uint8_t start_head; |
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uint32_t start_cylinder; |
90 |
uint8_t start_sector; |
91 |
uint8_t system; |
92 |
uint8_t end_head; |
93 |
uint8_t end_cylinder; |
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uint8_t end_sector; |
95 |
uint32_t start_sector_abs; |
96 |
uint32_t nb_sectors_abs; |
97 |
}; |
98 |
|
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static void read_partition(uint8_t *p, struct partition_record *r) |
100 |
{ |
101 |
r->bootable = p[0];
|
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r->start_head = p[1];
|
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r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); |
104 |
r->start_sector = p[2] & 0x3f; |
105 |
r->system = p[4];
|
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r->end_head = p[5];
|
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r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); |
108 |
r->end_sector = p[6] & 0x3f; |
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r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24; |
110 |
r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24; |
111 |
} |
112 |
|
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static int find_partition(BlockDriverState *bs, int partition, |
114 |
off_t *offset, off_t *size) |
115 |
{ |
116 |
struct partition_record mbr[4]; |
117 |
uint8_t data[512];
|
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int i;
|
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int ext_partnum = 4; |
120 |
int ret;
|
121 |
|
122 |
if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { |
123 |
errno = -ret; |
124 |
err(EXIT_FAILURE, "error while reading");
|
125 |
} |
126 |
|
127 |
if (data[510] != 0x55 || data[511] != 0xaa) { |
128 |
errno = -EINVAL; |
129 |
return -1; |
130 |
} |
131 |
|
132 |
for (i = 0; i < 4; i++) { |
133 |
read_partition(&data[446 + 16 * i], &mbr[i]); |
134 |
|
135 |
if (!mbr[i].nb_sectors_abs)
|
136 |
continue;
|
137 |
|
138 |
if (mbr[i].system == 0xF || mbr[i].system == 0x5) { |
139 |
struct partition_record ext[4]; |
140 |
uint8_t data1[512];
|
141 |
int j;
|
142 |
|
143 |
if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { |
144 |
errno = -ret; |
145 |
err(EXIT_FAILURE, "error while reading");
|
146 |
} |
147 |
|
148 |
for (j = 0; j < 4; j++) { |
149 |
read_partition(&data1[446 + 16 * j], &ext[j]); |
150 |
if (!ext[j].nb_sectors_abs)
|
151 |
continue;
|
152 |
|
153 |
if ((ext_partnum + j + 1) == partition) { |
154 |
*offset = (uint64_t)ext[j].start_sector_abs << 9;
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*size = (uint64_t)ext[j].nb_sectors_abs << 9;
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return 0; |
157 |
} |
158 |
} |
159 |
ext_partnum += 4;
|
160 |
} else if ((i + 1) == partition) { |
161 |
*offset = (uint64_t)mbr[i].start_sector_abs << 9;
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162 |
*size = (uint64_t)mbr[i].nb_sectors_abs << 9;
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163 |
return 0; |
164 |
} |
165 |
} |
166 |
|
167 |
errno = -ENOENT; |
168 |
return -1; |
169 |
} |
170 |
|
171 |
static void termsig_handler(int signum) |
172 |
{ |
173 |
static int sigterm_reported; |
174 |
if (!sigterm_reported) {
|
175 |
sigterm_reported = (write(sigterm_wfd, "", 1) == 1); |
176 |
} |
177 |
} |
178 |
|
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static void *show_parts(void *arg) |
180 |
{ |
181 |
int nbd;
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182 |
|
183 |
/* linux just needs an open() to trigger
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* the partition table update
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* but remember to load the module with max_part != 0 :
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* modprobe nbd max_part=63
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*/
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nbd = open(device, O_RDWR); |
189 |
if (nbd != -1) { |
190 |
close(nbd); |
191 |
} |
192 |
return NULL; |
193 |
} |
194 |
|
195 |
static void *nbd_client_thread(void *arg) |
196 |
{ |
197 |
int fd = *(int *)arg; |
198 |
off_t size; |
199 |
size_t blocksize; |
200 |
uint32_t nbdflags; |
201 |
int sock;
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int ret;
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203 |
pthread_t show_parts_thread; |
204 |
|
205 |
do {
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206 |
sock = unix_socket_outgoing(sockpath); |
207 |
if (sock == -1) { |
208 |
goto out;
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209 |
} |
210 |
} while (sock == -1); |
211 |
|
212 |
ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
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213 |
&size, &blocksize); |
214 |
if (ret == -1) { |
215 |
goto out;
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216 |
} |
217 |
|
218 |
ret = nbd_init(fd, sock, nbdflags, size, blocksize); |
219 |
if (ret == -1) { |
220 |
goto out;
|
221 |
} |
222 |
|
223 |
/* update partition table */
|
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pthread_create(&show_parts_thread, NULL, show_parts, NULL); |
225 |
|
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if (verbose) {
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fprintf(stderr, "NBD device %s is now connected to %s\n",
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device, srcpath); |
229 |
} else {
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230 |
/* Close stderr so that the qemu-nbd process exits. */
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dup2(STDOUT_FILENO, STDERR_FILENO); |
232 |
} |
233 |
|
234 |
ret = nbd_client(fd); |
235 |
if (ret) {
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goto out;
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237 |
} |
238 |
close(fd); |
239 |
kill(getpid(), SIGTERM); |
240 |
return (void *) EXIT_SUCCESS; |
241 |
|
242 |
out:
|
243 |
kill(getpid(), SIGTERM); |
244 |
return (void *) EXIT_FAILURE; |
245 |
} |
246 |
|
247 |
int main(int argc, char **argv) |
248 |
{ |
249 |
BlockDriverState *bs; |
250 |
off_t dev_offset = 0;
|
251 |
off_t offset = 0;
|
252 |
uint32_t nbdflags = 0;
|
253 |
bool disconnect = false; |
254 |
const char *bindto = "0.0.0.0"; |
255 |
int port = NBD_DEFAULT_PORT;
|
256 |
struct sockaddr_in addr;
|
257 |
socklen_t addr_len = sizeof(addr);
|
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off_t fd_size; |
259 |
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; |
260 |
struct option lopt[] = {
|
261 |
{ "help", 0, NULL, 'h' }, |
262 |
{ "version", 0, NULL, 'V' }, |
263 |
{ "bind", 1, NULL, 'b' }, |
264 |
{ "port", 1, NULL, 'p' }, |
265 |
{ "socket", 1, NULL, 'k' }, |
266 |
{ "offset", 1, NULL, 'o' }, |
267 |
{ "read-only", 0, NULL, 'r' }, |
268 |
{ "partition", 1, NULL, 'P' }, |
269 |
{ "connect", 1, NULL, 'c' }, |
270 |
{ "disconnect", 0, NULL, 'd' }, |
271 |
{ "snapshot", 0, NULL, 's' }, |
272 |
{ "nocache", 0, NULL, 'n' }, |
273 |
{ "shared", 1, NULL, 'e' }, |
274 |
{ "persistent", 0, NULL, 't' }, |
275 |
{ "verbose", 0, NULL, 'v' }, |
276 |
{ NULL, 0, NULL, 0 } |
277 |
}; |
278 |
int ch;
|
279 |
int opt_ind = 0; |
280 |
int li;
|
281 |
char *end;
|
282 |
int flags = BDRV_O_RDWR;
|
283 |
int partition = -1; |
284 |
int ret;
|
285 |
int shared = 1; |
286 |
uint8_t *data; |
287 |
fd_set fds; |
288 |
int *sharing_fds;
|
289 |
int fd;
|
290 |
int i;
|
291 |
int nb_fds = 0; |
292 |
int max_fd;
|
293 |
int persistent = 0; |
294 |
pthread_t client_thread; |
295 |
|
296 |
/* The client thread uses SIGTERM to interrupt the server. A signal
|
297 |
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
|
298 |
*/
|
299 |
struct sigaction sa_sigterm;
|
300 |
int sigterm_fd[2]; |
301 |
if (qemu_pipe(sigterm_fd) == -1) { |
302 |
err(EXIT_FAILURE, "Error setting up communication pipe");
|
303 |
} |
304 |
|
305 |
sigterm_wfd = sigterm_fd[1];
|
306 |
memset(&sa_sigterm, 0, sizeof(sa_sigterm)); |
307 |
sa_sigterm.sa_handler = termsig_handler; |
308 |
sigaction(SIGTERM, &sa_sigterm, NULL);
|
309 |
|
310 |
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { |
311 |
switch (ch) {
|
312 |
case 's': |
313 |
flags |= BDRV_O_SNAPSHOT; |
314 |
break;
|
315 |
case 'n': |
316 |
flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
317 |
break;
|
318 |
case 'b': |
319 |
bindto = optarg; |
320 |
break;
|
321 |
case 'p': |
322 |
li = strtol(optarg, &end, 0);
|
323 |
if (*end) {
|
324 |
errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
|
325 |
} |
326 |
if (li < 1 || li > 65535) { |
327 |
errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
|
328 |
} |
329 |
port = (uint16_t)li; |
330 |
break;
|
331 |
case 'o': |
332 |
dev_offset = strtoll (optarg, &end, 0);
|
333 |
if (*end) {
|
334 |
errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
|
335 |
} |
336 |
if (dev_offset < 0) { |
337 |
errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
|
338 |
} |
339 |
break;
|
340 |
case 'r': |
341 |
nbdflags |= NBD_FLAG_READ_ONLY; |
342 |
flags &= ~BDRV_O_RDWR; |
343 |
break;
|
344 |
case 'P': |
345 |
partition = strtol(optarg, &end, 0);
|
346 |
if (*end)
|
347 |
errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
|
348 |
if (partition < 1 || partition > 8) |
349 |
errx(EXIT_FAILURE, "Invalid partition %d", partition);
|
350 |
break;
|
351 |
case 'k': |
352 |
sockpath = optarg; |
353 |
if (sockpath[0] != '/') |
354 |
errx(EXIT_FAILURE, "socket path must be absolute\n");
|
355 |
break;
|
356 |
case 'd': |
357 |
disconnect = true;
|
358 |
break;
|
359 |
case 'c': |
360 |
device = optarg; |
361 |
break;
|
362 |
case 'e': |
363 |
shared = strtol(optarg, &end, 0);
|
364 |
if (*end) {
|
365 |
errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
|
366 |
} |
367 |
if (shared < 1) { |
368 |
errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
|
369 |
} |
370 |
break;
|
371 |
case 't': |
372 |
persistent = 1;
|
373 |
break;
|
374 |
case 'v': |
375 |
verbose = 1;
|
376 |
break;
|
377 |
case 'V': |
378 |
version(argv[0]);
|
379 |
exit(0);
|
380 |
break;
|
381 |
case 'h': |
382 |
usage(argv[0]);
|
383 |
exit(0);
|
384 |
break;
|
385 |
case '?': |
386 |
errx(EXIT_FAILURE, "Try `%s --help' for more information.",
|
387 |
argv[0]);
|
388 |
} |
389 |
} |
390 |
|
391 |
if ((argc - optind) != 1) { |
392 |
errx(EXIT_FAILURE, "Invalid number of argument.\n"
|
393 |
"Try `%s --help' for more information.",
|
394 |
argv[0]);
|
395 |
} |
396 |
|
397 |
if (disconnect) {
|
398 |
fd = open(argv[optind], O_RDWR); |
399 |
if (fd == -1) |
400 |
err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
|
401 |
|
402 |
nbd_disconnect(fd); |
403 |
|
404 |
close(fd); |
405 |
|
406 |
printf("%s disconnected\n", argv[optind]);
|
407 |
|
408 |
return 0; |
409 |
} |
410 |
|
411 |
if (device && !verbose) {
|
412 |
int stderr_fd[2]; |
413 |
pid_t pid; |
414 |
int ret;
|
415 |
|
416 |
if (qemu_pipe(stderr_fd) == -1) { |
417 |
err(EXIT_FAILURE, "Error setting up communication pipe");
|
418 |
} |
419 |
|
420 |
/* Now daemonize, but keep a communication channel open to
|
421 |
* print errors and exit with the proper status code.
|
422 |
*/
|
423 |
pid = fork(); |
424 |
if (pid == 0) { |
425 |
close(stderr_fd[0]);
|
426 |
ret = qemu_daemon(0, 0); |
427 |
|
428 |
/* Temporarily redirect stderr to the parent's pipe... */
|
429 |
dup2(stderr_fd[1], STDERR_FILENO);
|
430 |
if (ret == -1) { |
431 |
err(EXIT_FAILURE, "Failed to daemonize");
|
432 |
} |
433 |
|
434 |
/* ... close the descriptor we inherited and go on. */
|
435 |
close(stderr_fd[1]);
|
436 |
} else {
|
437 |
bool errors = false; |
438 |
char *buf;
|
439 |
|
440 |
/* In the parent. Print error messages from the child until
|
441 |
* it closes the pipe.
|
442 |
*/
|
443 |
close(stderr_fd[1]);
|
444 |
buf = g_malloc(1024);
|
445 |
while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { |
446 |
errors = true;
|
447 |
ret = qemu_write_full(STDERR_FILENO, buf, ret); |
448 |
if (ret == -1) { |
449 |
exit(EXIT_FAILURE); |
450 |
} |
451 |
} |
452 |
if (ret == -1) { |
453 |
err(EXIT_FAILURE, "Cannot read from daemon");
|
454 |
} |
455 |
|
456 |
/* Usually the daemon should not print any message.
|
457 |
* Exit with zero status in that case.
|
458 |
*/
|
459 |
exit(errors); |
460 |
} |
461 |
} |
462 |
|
463 |
if (device) {
|
464 |
/* Open before spawning new threads. In the future, we may
|
465 |
* drop privileges after opening.
|
466 |
*/
|
467 |
fd = open(device, O_RDWR); |
468 |
if (fd == -1) { |
469 |
err(EXIT_FAILURE, "Failed to open %s", device);
|
470 |
} |
471 |
|
472 |
if (sockpath == NULL) { |
473 |
sockpath = g_malloc(128);
|
474 |
snprintf(sockpath, 128, SOCKET_PATH, basename(device));
|
475 |
} |
476 |
} |
477 |
|
478 |
bdrv_init(); |
479 |
atexit(bdrv_close_all); |
480 |
|
481 |
bs = bdrv_new("hda");
|
482 |
srcpath = argv[optind]; |
483 |
if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) { |
484 |
errno = -ret; |
485 |
err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
|
486 |
} |
487 |
|
488 |
fd_size = bs->total_sectors * 512;
|
489 |
|
490 |
if (partition != -1 && |
491 |
find_partition(bs, partition, &dev_offset, &fd_size)) { |
492 |
err(EXIT_FAILURE, "Could not find partition %d", partition);
|
493 |
} |
494 |
|
495 |
sharing_fds = g_malloc((shared + 1) * sizeof(int)); |
496 |
|
497 |
if (sockpath) {
|
498 |
sharing_fds[0] = unix_socket_incoming(sockpath);
|
499 |
} else {
|
500 |
sharing_fds[0] = tcp_socket_incoming(bindto, port);
|
501 |
} |
502 |
|
503 |
if (sharing_fds[0] == -1) |
504 |
return 1; |
505 |
|
506 |
if (device) {
|
507 |
int ret;
|
508 |
|
509 |
ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd);
|
510 |
if (ret != 0) { |
511 |
errx(EXIT_FAILURE, "Failed to create client thread: %s",
|
512 |
strerror(ret)); |
513 |
} |
514 |
} else {
|
515 |
/* Shut up GCC warnings. */
|
516 |
memset(&client_thread, 0, sizeof(client_thread)); |
517 |
} |
518 |
|
519 |
max_fd = sharing_fds[0];
|
520 |
nb_fds++; |
521 |
|
522 |
data = qemu_blockalign(bs, NBD_BUFFER_SIZE); |
523 |
if (data == NULL) { |
524 |
errx(EXIT_FAILURE, "Cannot allocate data buffer");
|
525 |
} |
526 |
|
527 |
do {
|
528 |
FD_ZERO(&fds); |
529 |
FD_SET(sigterm_fd[0], &fds);
|
530 |
for (i = 0; i < nb_fds; i++) |
531 |
FD_SET(sharing_fds[i], &fds); |
532 |
|
533 |
do {
|
534 |
ret = select(max_fd + 1, &fds, NULL, NULL, NULL); |
535 |
} while (ret == -1 && errno == EINTR); |
536 |
if (ret == -1 || FD_ISSET(sigterm_fd[0], &fds)) { |
537 |
break;
|
538 |
} |
539 |
|
540 |
if (FD_ISSET(sharing_fds[0], &fds)) |
541 |
ret--; |
542 |
for (i = 1; i < nb_fds && ret; i++) { |
543 |
if (FD_ISSET(sharing_fds[i], &fds)) {
|
544 |
if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
|
545 |
&offset, nbdflags, data, NBD_BUFFER_SIZE) != 0) {
|
546 |
close(sharing_fds[i]); |
547 |
nb_fds--; |
548 |
sharing_fds[i] = sharing_fds[nb_fds]; |
549 |
i--; |
550 |
} |
551 |
ret--; |
552 |
} |
553 |
} |
554 |
/* new connection ? */
|
555 |
if (FD_ISSET(sharing_fds[0], &fds)) { |
556 |
if (nb_fds < shared + 1) { |
557 |
sharing_fds[nb_fds] = accept(sharing_fds[0],
|
558 |
(struct sockaddr *)&addr,
|
559 |
&addr_len); |
560 |
if (sharing_fds[nb_fds] != -1 && |
561 |
nbd_negotiate(sharing_fds[nb_fds], fd_size, nbdflags) != -1) {
|
562 |
if (sharing_fds[nb_fds] > max_fd)
|
563 |
max_fd = sharing_fds[nb_fds]; |
564 |
nb_fds++; |
565 |
} |
566 |
} |
567 |
} |
568 |
} while (persistent || nb_fds > 1); |
569 |
qemu_vfree(data); |
570 |
|
571 |
close(sharing_fds[0]);
|
572 |
g_free(sharing_fds); |
573 |
if (sockpath) {
|
574 |
unlink(sockpath); |
575 |
} |
576 |
|
577 |
if (device) {
|
578 |
void *ret;
|
579 |
pthread_join(client_thread, &ret); |
580 |
exit(ret != NULL);
|
581 |
} else {
|
582 |
exit(EXIT_SUCCESS); |
583 |
} |
584 |
} |