qemu/qemu-nbd.c

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/*\
* 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/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
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"
" -r, --read-only export read-only\n"
" -P, --partition=NUM only expose partition NUM\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);
}
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;
}
int main(int argc, char **argv)
{
BlockDriverState *bs;
off_t dev_offset = 0;
off_t offset = 0;
bool readonly = false;
const char *bindto = "0.0.0.0";
int port = 1024;
int sock, csock;
struct sockaddr_in addr;
socklen_t addr_len = sizeof(addr);
off_t fd_size;
const char *sopt = "hVbo:p:rsP:v";
struct option lopt[] = {
{ "help", 0, 0, 'h' },
{ "version", 0, 0, 'V' },
{ "bind", 1, 0, 'b' },
{ "port", 1, 0, 'p' },
{ "offset", 1, 0, 'o' },
{ "read-only", 0, 0, 'r' },
{ "partition", 1, 0, 'P' },
{ "snapshot", 0, 0, 's' },
{ "verbose", 0, 0, 'v' },
{ NULL, 0, 0, 0 }
};
int ch;
int opt_ind = 0;
int li;
char *end;
bool snapshot = false;
int partition = -1;
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 's':
snapshot = true;
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 '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]);
}
bdrv_init();
bs = bdrv_new("hda");
if (bs == NULL)
return 1;
if (bdrv_open(bs, argv[optind], snapshot) == -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);
sock = tcp_socket_incoming(bindto, port);
if (sock == -1)
return 1;
csock = accept(sock,
(struct sockaddr *)&addr,
&addr_len);
if (csock == -1)
return 1;
/* new fd_size is calculated by find_partition */
if (nbd_negotiate(bs, csock, fd_size) == -1)
return 1;
while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly) == 0);
close(csock);
close(sock);
bdrv_close(bs);
return 0;
}