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qemu-nbd tool (Anthony Liguori) 

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4596 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2008-05-27 21:13:40 +00:00
parent e00c1e714e
commit 7a5ca8648b
7 changed files with 881 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Makefile
View File

@ -17,7 +17,7 @@ ifdef CONFIG_STATIC
LDFLAGS += -static
endif
ifdef BUILD_DOCS
DOCS=qemu-doc.html qemu-tech.html qemu.1 qemu-img.1
DOCS=qemu-doc.html qemu-tech.html qemu.1 qemu-img.1 qemu-nbd.8
else
DOCS=
endif
@ -159,6 +159,10 @@ qemu-img-%.o: %.c
%.o: %.c
$(CC) $(CFLAGS) $(CPPFLAGS) -c -o $@ $<
qemu-nbd$(EXESUF): qemu-nbd.o nbd.o qemu-img-block.o \
$(QEMU_IMG_BLOCK_OBJS)
$(CC) $(LDFLAGS) -o $@ $^ -lz $(LIBS)
# dyngen host tool
dyngen$(EXESUF): dyngen.c
$(HOST_CC) $(CFLAGS) $(CPPFLAGS) -o $@ $^
@ -191,6 +195,8 @@ install-doc: $(DOCS)
ifndef CONFIG_WIN32
mkdir -p "$(DESTDIR)$(mandir)/man1"
$(INSTALL) qemu.1 qemu-img.1 "$(DESTDIR)$(mandir)/man1"
mkdir -p "$(DESTDIR)$(mandir)/man8"
$(INSTALL) qemu-nbd.8 "$(DESTDIR)$(mandir)/man8"
endif
install: all $(if $(BUILD_DOCS),install-doc)
@ -244,6 +250,10 @@ qemu-img.1: qemu-img.texi
$(SRC_PATH)/texi2pod.pl $< qemu-img.pod
pod2man --section=1 --center=" " --release=" " qemu-img.pod > $@
qemu-nbd.8: qemu-nbd.texi
$(SRC_PATH)/texi2pod.pl $< qemu-nbd.pod
pod2man --section=8 --center=" " --release=" " qemu-nbd.pod > $@
info: qemu-doc.info qemu-tech.info
dvi: qemu-doc.dvi qemu-tech.dvi
@ -296,6 +306,7 @@ tarbin:
$(bindir)/qemu-sh4eb \
$(bindir)/qemu-cris \
$(bindir)/qemu-img \
$(bindir)/qemu-nbd \
$(datadir)/bios.bin \
$(datadir)/vgabios.bin \
$(datadir)/vgabios-cirrus.bin \
@ -309,6 +320,7 @@ tarbin:
$(docdir)/qemu-doc.html \
$(docdir)/qemu-tech.html \
$(mandir)/man1/qemu.1 $(mandir)/man1/qemu-img.1
$(mandir)/man8/qemu-nbd.8
# Include automatically generated dependency files
-include $(wildcard *.d audio/*.d slirp/*.d)

3
configure vendored
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@ -1105,6 +1105,9 @@ echo "#define CONFIG_UNAME_RELEASE \"$uname_release\"" >> $config_h
tools=
if test `expr "$target_list" : ".*softmmu.*"` != 0 ; then
tools="qemu-img\$(EXESUF) $tools"
if [ "$linux" = "yes" ] ; then
tools="qemu-nbd\$(EXESUF) $tools"
fi
fi
echo "TOOLS=$tools" >> $config_mak

2
exec-all.h
View File

@ -126,7 +126,7 @@ static inline int tlb_set_page(CPUState *env1, target_ulong vaddr,
#define CODE_GEN_BUFFER_SIZE (6 * 1024 * 1024)
#else
/* XXX: make it dynamic on x86 */
#define CODE_GEN_BUFFER_SIZE (16 * 1024 * 1024)
#define CODE_GEN_BUFFER_SIZE (64 * 1024 * 1024)
#endif
//#define CODE_GEN_BUFFER_SIZE (128 * 1024)

500
nbd.c Normal file
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@ -0,0 +1,500 @@
/*\
* 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 "nbd.h"
#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>
#include <ctype.h>
#include <inttypes.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
extern int verbose;
#define LOG(msg, ...) do { \
fprintf(stderr, "%s:%s():L%d: " msg "\n", \
__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
} while(0)
#define TRACE(msg, ...) do { \
if (verbose) LOG(msg, ## __VA_ARGS__); \
} while(0)
/* This is all part of the "official" NBD API */
#define NBD_REQUEST_MAGIC 0x25609513
#define NBD_REPLY_MAGIC 0x67446698
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
#define NBD_SET_SIZE _IO(0xab, 2)
#define NBD_DO_IT _IO(0xab, 3)
#define NBD_CLEAR_SOCK _IO(0xab, 4)
#define NBD_CLEAR_QUE _IO(0xab, 5)
#define NBD_PRINT_DEBUG _IO(0xab, 6)
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
/* That's all folks */
#define read_sync(fd, buffer, size) wr_sync(fd, buffer, size, true)
#define write_sync(fd, buffer, size) wr_sync(fd, buffer, size, false)
static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read)
{
size_t offset = 0;
while (offset < size) {
ssize_t len;
if (do_read) {
len = read(fd, buffer + offset, size - offset);
} else {
len = write(fd, buffer + offset, size - offset);
}
/* recoverable error */
if (len == -1 && errno == EAGAIN) {
continue;
}
/* eof */
if (len == 0) {
break;
}
/* unrecoverable error */
if (len == -1) {
return 0;
}
offset += len;
}
return offset;
}
static int tcp_socket_outgoing(const char *address, uint16_t port)
{
int s;
struct in_addr in;
struct sockaddr_in addr;
int serrno;
s = socket(PF_INET, SOCK_STREAM, 0);
if (s == -1) {
return -1;
}
if (inet_aton(address, &in) == 0) {
struct hostent *ent;
ent = gethostbyname(address);
if (ent == NULL) {
goto error;
}
memcpy(&in, ent->h_addr, sizeof(in));
}
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
goto error;
}
return s;
error:
serrno = errno;
close(s);
errno = serrno;
return -1;
}
int tcp_socket_incoming(const char *address, uint16_t port)
{
int s;
struct in_addr in;
struct sockaddr_in addr;
int serrno;
int opt;
s = socket(PF_INET, SOCK_STREAM, 0);
if (s == -1) {
return -1;
}
if (inet_aton(address, &in) == 0) {
struct hostent *ent;
ent = gethostbyname(address);
if (ent == NULL) {
goto error;
}
memcpy(&in, ent->h_addr, sizeof(in));
}
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
opt = 1;
if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
goto error;
}
if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
goto error;
}
if (listen(s, 128) == -1) {
goto error;
}
return s;
error:
serrno = errno;
close(s);
errno = serrno;
return -1;
}
/* Basic flow
Server Client
Negotiate
Request
Response
Request
Response
...
...
Request (type == 2)
*/
int nbd_negotiate(BlockDriverState *bs, int csock, off_t size)
{
char buf[8 + 8 + 8 + 128];
/* Negotiate
[ 0 .. 7] passwd ("NBDMAGIC")
[ 8 .. 15] magic (0x00420281861253)
[16 .. 23] size
[24 .. 151] reserved (0)
*/
TRACE("Beginning negotiation.");
memcpy(buf, "NBDMAGIC", 8);
cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
cpu_to_be64w((uint64_t*)(buf + 16), size);
memset(buf + 24, 0, 128);
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
LOG("write failed");
errno = EINVAL;
return -1;
}
TRACE("Negotation succeeded.");
return 0;
}
int nbd_receive_negotiate(int fd, int csock)
{
char buf[8 + 8 + 8 + 128];
uint64_t magic;
off_t size;
size_t blocksize;
TRACE("Receiving negotation.");
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
LOG("read failed");
errno = EINVAL;
return -1;
}
magic = be64_to_cpup((uint64_t*)(buf + 8));
size = be64_to_cpup((uint64_t*)(buf + 16));
blocksize = 1024;
TRACE("Magic is %c%c%c%c%c%c%c%c",
isprint(buf[0]) ? buf[0] : '.',
isprint(buf[1]) ? buf[1] : '.',
isprint(buf[2]) ? buf[2] : '.',
isprint(buf[3]) ? buf[3] : '.',
isprint(buf[4]) ? buf[4] : '.',
isprint(buf[5]) ? buf[5] : '.',
isprint(buf[6]) ? buf[6] : '.',
isprint(buf[7]) ? buf[7] : '.');
TRACE("Magic is 0x%" PRIx64, magic);
TRACE("Size is %" PRIu64, size);
if (memcmp(buf, "NBDMAGIC", 8) != 0) {
LOG("Invalid magic received");
errno = EINVAL;
return -1;
}
TRACE("Checking magic");
if (magic != 0x00420281861253LL) {
LOG("Bad magic received");
errno = EINVAL;
return -1;
}
TRACE("Setting block size to %lu", (unsigned long)blocksize);
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
int serrno = errno;
LOG("Failed setting NBD block size");
errno = serrno;
return -1;
}
TRACE("Setting size to %llu block(s)",
(unsigned long long)(size / blocksize));
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
int serrno = errno;
LOG("Failed setting size (in blocks)");
errno = serrno;
return -1;
}
TRACE("Clearing NBD socket");
if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
int serrno = errno;
LOG("Failed clearing NBD socket");
errno = serrno;
return -1;
}
TRACE("Setting NBD socket");
if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
int serrno = errno;
LOG("Failed to set NBD socket");
errno = serrno;
return -1;
}
TRACE("Negotiation ended");
return 0;
}
int nbd_disconnect(int fd)
{
ioctl(fd, NBD_CLEAR_QUE);
ioctl(fd, NBD_DISCONNECT);
ioctl(fd, NBD_CLEAR_SOCK);
return 0;
}
int nbd_client(int fd, int csock)
{
int ret;
int serrno;
TRACE("Doing NBD loop");
ret = ioctl(fd, NBD_DO_IT);
serrno = errno;
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
TRACE("Clearing NBD queue");
ioctl(fd, NBD_CLEAR_QUE);
TRACE("Clearing NBD socket");
ioctl(fd, NBD_CLEAR_SOCK);
errno = serrno;
return ret;
}
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly)
{
#ifndef _REENTRANT
static uint8_t data[1024 * 1024]; // keep this off of the stack
#else
uint8_t data[1024 * 1024];
#endif
uint8_t buf[4 + 4 + 8 + 8 + 4];
uint32_t magic;
uint32_t type;
uint64_t from;
uint32_t len;
TRACE("Reading request.");
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
LOG("read failed");
errno = EINVAL;
return -1;
}
/* Request
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
[ 4 .. 7] type (0 == READ, 1 == WRITE)
[ 8 .. 15] handle
[16 .. 23] from
[24 .. 27] len
*/
magic = be32_to_cpup((uint32_t*)buf);
type = be32_to_cpup((uint32_t*)(buf + 4));
from = be64_to_cpup((uint64_t*)(buf + 16));
len = be32_to_cpup((uint32_t*)(buf + 24));
TRACE("Got request: "
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
magic, type, from, len);
if (magic != NBD_REQUEST_MAGIC) {
LOG("invalid magic (got 0x%x)", magic);
errno = EINVAL;
return -1;
}
if (len > sizeof(data)) {
LOG("len (%u) is larger than max len (%lu)",
len, sizeof(data));
errno = EINVAL;
return -1;
}
if ((from + len) < from) {
LOG("integer overflow detected! "
"you're probably being attacked");
errno = EINVAL;
return -1;
}
if ((from + len) > size) {
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
", Offset: %" PRIu64 "\n",
from, len, size, dev_offset);
LOG("requested operation past EOF--bad client?");
errno = EINVAL;
return -1;
}
/* Reply
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
[ 4 .. 7] error (0 == no error)
[ 7 .. 15] handle
*/
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
cpu_to_be32w((uint32_t*)(buf + 4), 0);
TRACE("Decoding type");
switch (type) {
case 0:
TRACE("Request type is READ");
if (bdrv_read(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
LOG("reading from file failed");
errno = EINVAL;
return -1;
}
*offset += len;
TRACE("Read %u byte(s)", len);
TRACE("Sending OK response");
if (write_sync(csock, buf, 16) != 16) {
LOG("writing to socket failed");
errno = EINVAL;
return -1;
}
TRACE("Sending data to client");
if (write_sync(csock, data, len) != len) {
LOG("writing to socket failed");
errno = EINVAL;
return -1;
}
break;
case 1:
TRACE("Request type is WRITE");
TRACE("Reading %u byte(s)", len);
if (read_sync(csock, data, len) != len) {
LOG("reading from socket failed");
errno = EINVAL;
return -1;
}
if (readonly) {
TRACE("Server is read-only, return error");
cpu_to_be32w((uint32_t*)(buf + 4), 1);
} else {
TRACE("Writing to device");
if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
LOG("writing to file failed");
errno = EINVAL;
return -1;
}
*offset += len;
}
TRACE("Sending response to client");
if (write_sync(csock, buf, 16) != 16) {
LOG("writing to socket failed");
errno = EINVAL;
return -1;
}
break;
case 2:
TRACE("Request type is DISCONNECT");
errno = 0;
return 1;
default:
LOG("invalid request type (%u) received", type);
errno = EINVAL;
return -1;
}
TRACE("Request/Reply complete");
return 0;
}

37
nbd.h Normal file
View File

@ -0,0 +1,37 @@
/*\
* 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
\*/
#ifndef NBD_H
#define NBD_H
#include <sys/types.h>
#include <stdbool.h>
#include <qemu-common.h>
#include "block_int.h"
int tcp_socket_incoming(const char *address, uint16_t port);
int nbd_negotiate(BlockDriverState *bs, int csock, off_t size);
int nbd_receive_negotiate(int fd, int csock);
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly);
int nbd_client(int fd, int csock);
int nbd_disconnect(int fd);
#endif

275
qemu-nbd.c Normal file
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@ -0,0 +1,275 @@
/*\
* 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 <malloc.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' },
};
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;
}

52
qemu-nbd.texi Normal file
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@ -0,0 +1,52 @@
@example
@c man begin SYNOPSIS
usage: qemu-nbd [OPTION]... @var{filename}
@c man end
@end example
@c man begin DESCRIPTION
Export Qemu disk image using NBD protocol.
@c man end
@c man begin OPTIONS
@table @var
@item filename
is a disk image filename
@item -p, --port=PORT
port to listen on (default `1024')
@item -o, --offset=OFFSET
offset into the image
@item -b, --bind=IFACE
interface to bind to (default `0.0.0.0')
@item -r, --read-only
export read-only
@item -P, --partition=NUM
only expose partition NUM
@item -v, --verbose
display extra debugging information
@item -h, --help
display this help and exit
@item -V, --version
output version information and exit
@end table
@c man end
@ignore
@setfilename qemu-nbd
@settitle QEMU Disk Network Block Device Server
@c man begin AUTHOR
Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
@c man end
@c man begin SEEALSO
qemu-img(1)
@c man end
@end ignore