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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" |
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#include "block_int.h" |
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#include "nbd.h" |
22 |
|
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#include <stdarg.h> |
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#include <stdio.h> |
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#include <getopt.h> |
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#include <err.h> |
27 |
#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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#include <netinet/tcp.h> |
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#include <arpa/inet.h> |
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#include <signal.h> |
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#include <libgen.h> |
34 |
#include <pthread.h> |
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|
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#define SOCKET_PATH "/var/lock/qemu-nbd-%s" |
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|
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static NBDExport *exp;
|
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static int verbose; |
40 |
static char *device; |
41 |
static char *srcpath; |
42 |
static char *sockpath; |
43 |
static bool sigterm_reported; |
44 |
static bool nbd_started; |
45 |
static int shared = 1; |
46 |
static int nb_fds; |
47 |
|
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static void usage(const char *name) |
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{ |
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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" |
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" -r, --read-only export read-only\n"
|
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" -P, --partition=NUM only expose partition NUM\n"
|
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" -s, --snapshot use snapshot file\n"
|
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" -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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} |
74 |
|
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static void version(const char *name) |
76 |
{ |
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printf( |
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"%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); |
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} |
86 |
|
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struct partition_record
|
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{ |
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uint8_t bootable; |
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uint8_t start_head; |
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uint32_t start_cylinder; |
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uint8_t start_sector; |
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uint8_t system; |
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uint8_t end_head; |
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uint8_t end_cylinder; |
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uint8_t end_sector; |
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uint32_t start_sector_abs; |
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uint32_t nb_sectors_abs; |
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}; |
100 |
|
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static void read_partition(uint8_t *p, struct partition_record *r) |
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{ |
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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); |
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r->start_sector = p[2] & 0x3f; |
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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); |
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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; |
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r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24; |
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} |
114 |
|
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static int find_partition(BlockDriverState *bs, int partition, |
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off_t *offset, off_t *size) |
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{ |
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struct partition_record mbr[4]; |
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uint8_t data[512];
|
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int i;
|
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int ext_partnum = 4; |
122 |
int ret;
|
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|
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if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { |
125 |
errno = -ret; |
126 |
err(EXIT_FAILURE, "error while reading");
|
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} |
128 |
|
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if (data[510] != 0x55 || data[511] != 0xaa) { |
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errno = -EINVAL; |
131 |
return -1; |
132 |
} |
133 |
|
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for (i = 0; i < 4; i++) { |
135 |
read_partition(&data[446 + 16 * i], &mbr[i]); |
136 |
|
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if (!mbr[i].nb_sectors_abs)
|
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continue;
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139 |
|
140 |
if (mbr[i].system == 0xF || mbr[i].system == 0x5) { |
141 |
struct partition_record ext[4]; |
142 |
uint8_t data1[512];
|
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int j;
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144 |
|
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if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { |
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errno = -ret; |
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err(EXIT_FAILURE, "error while reading");
|
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} |
149 |
|
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for (j = 0; j < 4; j++) { |
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read_partition(&data1[446 + 16 * j], &ext[j]); |
152 |
if (!ext[j].nb_sectors_abs)
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continue;
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154 |
|
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if ((ext_partnum + j + 1) == partition) { |
156 |
*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; |
159 |
} |
160 |
} |
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ext_partnum += 4;
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} else if ((i + 1) == partition) { |
163 |
*offset = (uint64_t)mbr[i].start_sector_abs << 9;
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*size = (uint64_t)mbr[i].nb_sectors_abs << 9;
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return 0; |
166 |
} |
167 |
} |
168 |
|
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errno = -ENOENT; |
170 |
return -1; |
171 |
} |
172 |
|
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static void termsig_handler(int signum) |
174 |
{ |
175 |
sigterm_reported = true;
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qemu_notify_event(); |
177 |
} |
178 |
|
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static void *show_parts(void *arg) |
180 |
{ |
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int nbd;
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|
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/* 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 |
|
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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; |
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int sock;
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int ret;
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pthread_t show_parts_thread; |
204 |
|
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sock = unix_socket_outgoing(sockpath); |
206 |
if (sock == -1) { |
207 |
goto out;
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} |
209 |
|
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ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
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&size, &blocksize); |
212 |
if (ret == -1) { |
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goto out;
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} |
215 |
|
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ret = nbd_init(fd, sock, nbdflags, size, blocksize); |
217 |
if (ret == -1) { |
218 |
goto out;
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} |
220 |
|
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/* update partition table */
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pthread_create(&show_parts_thread, NULL, show_parts, NULL); |
223 |
|
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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); |
227 |
} else {
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/* Close stderr so that the qemu-nbd process exits. */
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dup2(STDOUT_FILENO, STDERR_FILENO); |
230 |
} |
231 |
|
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ret = nbd_client(fd); |
233 |
if (ret) {
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goto out;
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} |
236 |
close(fd); |
237 |
kill(getpid(), SIGTERM); |
238 |
return (void *) EXIT_SUCCESS; |
239 |
|
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out:
|
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kill(getpid(), SIGTERM); |
242 |
return (void *) EXIT_FAILURE; |
243 |
} |
244 |
|
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static int nbd_can_accept(void *opaque) |
246 |
{ |
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return nb_fds < shared;
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} |
249 |
|
250 |
static void nbd_client_closed(NBDClient *client) |
251 |
{ |
252 |
nb_fds--; |
253 |
qemu_notify_event(); |
254 |
} |
255 |
|
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static void nbd_accept(void *opaque) |
257 |
{ |
258 |
int server_fd = (uintptr_t) opaque;
|
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struct sockaddr_in addr;
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socklen_t addr_len = sizeof(addr);
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|
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int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); |
263 |
nbd_started = true;
|
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if (fd != -1 && nbd_client_new(exp, fd, nbd_client_closed)) { |
265 |
nb_fds++; |
266 |
} |
267 |
} |
268 |
|
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int main(int argc, char **argv) |
270 |
{ |
271 |
BlockDriverState *bs; |
272 |
off_t dev_offset = 0;
|
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uint32_t nbdflags = 0;
|
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bool disconnect = false; |
275 |
const char *bindto = "0.0.0.0"; |
276 |
int port = NBD_DEFAULT_PORT;
|
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off_t fd_size; |
278 |
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; |
279 |
struct option lopt[] = {
|
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{ "help", 0, NULL, 'h' }, |
281 |
{ "version", 0, NULL, 'V' }, |
282 |
{ "bind", 1, NULL, 'b' }, |
283 |
{ "port", 1, NULL, 'p' }, |
284 |
{ "socket", 1, NULL, 'k' }, |
285 |
{ "offset", 1, NULL, 'o' }, |
286 |
{ "read-only", 0, NULL, 'r' }, |
287 |
{ "partition", 1, NULL, 'P' }, |
288 |
{ "connect", 1, NULL, 'c' }, |
289 |
{ "disconnect", 0, NULL, 'd' }, |
290 |
{ "snapshot", 0, NULL, 's' }, |
291 |
{ "nocache", 0, NULL, 'n' }, |
292 |
{ "shared", 1, NULL, 'e' }, |
293 |
{ "persistent", 0, NULL, 't' }, |
294 |
{ "verbose", 0, NULL, 'v' }, |
295 |
{ NULL, 0, NULL, 0 } |
296 |
}; |
297 |
int ch;
|
298 |
int opt_ind = 0; |
299 |
int li;
|
300 |
char *end;
|
301 |
int flags = BDRV_O_RDWR;
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302 |
int partition = -1; |
303 |
int ret;
|
304 |
int fd;
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305 |
int persistent = 0; |
306 |
pthread_t client_thread; |
307 |
|
308 |
/* The client thread uses SIGTERM to interrupt the server. A signal
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309 |
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
|
310 |
*/
|
311 |
struct sigaction sa_sigterm;
|
312 |
memset(&sa_sigterm, 0, sizeof(sa_sigterm)); |
313 |
sa_sigterm.sa_handler = termsig_handler; |
314 |
sigaction(SIGTERM, &sa_sigterm, NULL);
|
315 |
|
316 |
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { |
317 |
switch (ch) {
|
318 |
case 's': |
319 |
flags |= BDRV_O_SNAPSHOT; |
320 |
break;
|
321 |
case 'n': |
322 |
flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
323 |
break;
|
324 |
case 'b': |
325 |
bindto = optarg; |
326 |
break;
|
327 |
case 'p': |
328 |
li = strtol(optarg, &end, 0);
|
329 |
if (*end) {
|
330 |
errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
|
331 |
} |
332 |
if (li < 1 || li > 65535) { |
333 |
errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
|
334 |
} |
335 |
port = (uint16_t)li; |
336 |
break;
|
337 |
case 'o': |
338 |
dev_offset = strtoll (optarg, &end, 0);
|
339 |
if (*end) {
|
340 |
errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
|
341 |
} |
342 |
if (dev_offset < 0) { |
343 |
errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
|
344 |
} |
345 |
break;
|
346 |
case 'r': |
347 |
nbdflags |= NBD_FLAG_READ_ONLY; |
348 |
flags &= ~BDRV_O_RDWR; |
349 |
break;
|
350 |
case 'P': |
351 |
partition = strtol(optarg, &end, 0);
|
352 |
if (*end)
|
353 |
errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
|
354 |
if (partition < 1 || partition > 8) |
355 |
errx(EXIT_FAILURE, "Invalid partition %d", partition);
|
356 |
break;
|
357 |
case 'k': |
358 |
sockpath = optarg; |
359 |
if (sockpath[0] != '/') |
360 |
errx(EXIT_FAILURE, "socket path must be absolute\n");
|
361 |
break;
|
362 |
case 'd': |
363 |
disconnect = true;
|
364 |
break;
|
365 |
case 'c': |
366 |
device = optarg; |
367 |
break;
|
368 |
case 'e': |
369 |
shared = strtol(optarg, &end, 0);
|
370 |
if (*end) {
|
371 |
errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
|
372 |
} |
373 |
if (shared < 1) { |
374 |
errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
|
375 |
} |
376 |
break;
|
377 |
case 't': |
378 |
persistent = 1;
|
379 |
break;
|
380 |
case 'v': |
381 |
verbose = 1;
|
382 |
break;
|
383 |
case 'V': |
384 |
version(argv[0]);
|
385 |
exit(0);
|
386 |
break;
|
387 |
case 'h': |
388 |
usage(argv[0]);
|
389 |
exit(0);
|
390 |
break;
|
391 |
case '?': |
392 |
errx(EXIT_FAILURE, "Try `%s --help' for more information.",
|
393 |
argv[0]);
|
394 |
} |
395 |
} |
396 |
|
397 |
if ((argc - optind) != 1) { |
398 |
errx(EXIT_FAILURE, "Invalid number of argument.\n"
|
399 |
"Try `%s --help' for more information.",
|
400 |
argv[0]);
|
401 |
} |
402 |
|
403 |
if (disconnect) {
|
404 |
fd = open(argv[optind], O_RDWR); |
405 |
if (fd == -1) |
406 |
err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
|
407 |
|
408 |
nbd_disconnect(fd); |
409 |
|
410 |
close(fd); |
411 |
|
412 |
printf("%s disconnected\n", argv[optind]);
|
413 |
|
414 |
return 0; |
415 |
} |
416 |
|
417 |
if (device && !verbose) {
|
418 |
int stderr_fd[2]; |
419 |
pid_t pid; |
420 |
int ret;
|
421 |
|
422 |
if (qemu_pipe(stderr_fd) == -1) { |
423 |
err(EXIT_FAILURE, "Error setting up communication pipe");
|
424 |
} |
425 |
|
426 |
/* Now daemonize, but keep a communication channel open to
|
427 |
* print errors and exit with the proper status code.
|
428 |
*/
|
429 |
pid = fork(); |
430 |
if (pid == 0) { |
431 |
close(stderr_fd[0]);
|
432 |
ret = qemu_daemon(0, 0); |
433 |
|
434 |
/* Temporarily redirect stderr to the parent's pipe... */
|
435 |
dup2(stderr_fd[1], STDERR_FILENO);
|
436 |
if (ret == -1) { |
437 |
err(EXIT_FAILURE, "Failed to daemonize");
|
438 |
} |
439 |
|
440 |
/* ... close the descriptor we inherited and go on. */
|
441 |
close(stderr_fd[1]);
|
442 |
} else {
|
443 |
bool errors = false; |
444 |
char *buf;
|
445 |
|
446 |
/* In the parent. Print error messages from the child until
|
447 |
* it closes the pipe.
|
448 |
*/
|
449 |
close(stderr_fd[1]);
|
450 |
buf = g_malloc(1024);
|
451 |
while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { |
452 |
errors = true;
|
453 |
ret = qemu_write_full(STDERR_FILENO, buf, ret); |
454 |
if (ret == -1) { |
455 |
exit(EXIT_FAILURE); |
456 |
} |
457 |
} |
458 |
if (ret == -1) { |
459 |
err(EXIT_FAILURE, "Cannot read from daemon");
|
460 |
} |
461 |
|
462 |
/* Usually the daemon should not print any message.
|
463 |
* Exit with zero status in that case.
|
464 |
*/
|
465 |
exit(errors); |
466 |
} |
467 |
} |
468 |
|
469 |
if (device) {
|
470 |
/* Open before spawning new threads. In the future, we may
|
471 |
* drop privileges after opening.
|
472 |
*/
|
473 |
fd = open(device, O_RDWR); |
474 |
if (fd == -1) { |
475 |
err(EXIT_FAILURE, "Failed to open %s", device);
|
476 |
} |
477 |
|
478 |
if (sockpath == NULL) { |
479 |
sockpath = g_malloc(128);
|
480 |
snprintf(sockpath, 128, SOCKET_PATH, basename(device));
|
481 |
} |
482 |
} |
483 |
|
484 |
bdrv_init(); |
485 |
atexit(bdrv_close_all); |
486 |
|
487 |
bs = bdrv_new("hda");
|
488 |
srcpath = argv[optind]; |
489 |
if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) { |
490 |
errno = -ret; |
491 |
err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
|
492 |
} |
493 |
|
494 |
fd_size = bs->total_sectors * 512;
|
495 |
|
496 |
if (partition != -1 && |
497 |
find_partition(bs, partition, &dev_offset, &fd_size)) { |
498 |
err(EXIT_FAILURE, "Could not find partition %d", partition);
|
499 |
} |
500 |
|
501 |
exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags); |
502 |
|
503 |
if (sockpath) {
|
504 |
fd = unix_socket_incoming(sockpath); |
505 |
} else {
|
506 |
fd = tcp_socket_incoming(bindto, port); |
507 |
} |
508 |
|
509 |
if (fd == -1) { |
510 |
return 1; |
511 |
} |
512 |
|
513 |
if (device) {
|
514 |
int ret;
|
515 |
|
516 |
ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd);
|
517 |
if (ret != 0) { |
518 |
errx(EXIT_FAILURE, "Failed to create client thread: %s",
|
519 |
strerror(ret)); |
520 |
} |
521 |
} else {
|
522 |
/* Shut up GCC warnings. */
|
523 |
memset(&client_thread, 0, sizeof(client_thread)); |
524 |
} |
525 |
|
526 |
qemu_init_main_loop(); |
527 |
qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
|
528 |
(void *)(uintptr_t)fd);
|
529 |
|
530 |
do {
|
531 |
main_loop_wait(false);
|
532 |
} while (!sigterm_reported && (persistent || !nbd_started || nb_fds > 0)); |
533 |
|
534 |
nbd_export_close(exp); |
535 |
if (sockpath) {
|
536 |
unlink(sockpath); |
537 |
} |
538 |
|
539 |
if (device) {
|
540 |
void *ret;
|
541 |
pthread_join(client_thread, &ret); |
542 |
exit(ret != NULL);
|
543 |
} else {
|
544 |
exit(EXIT_SUCCESS); |
545 |
} |
546 |
} |