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authorbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2008-05-27 21:13:40 +0000
committerbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2008-05-27 21:13:40 +0000
commit7a5ca8648b6a3ecd359bc3029b2988de452494e9 (patch)
tree647cafb3d65d8fd45309ee0b8a9c08616c98329b
parente00c1e714e15ebb813d120906d789f9ef09f031b (diff)
qemu-nbd tool (Anthony Liguori)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4596 c046a42c-6fe2-441c-8c8c-71466251a162
-rw-r--r--Makefile14
-rwxr-xr-xconfigure3
-rw-r--r--exec-all.h2
-rw-r--r--nbd.c500
-rw-r--r--nbd.h37
-rw-r--r--qemu-nbd.c275
-rw-r--r--qemu-nbd.texi52
7 files changed, 881 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index 5bf9bbd34..742494367 100644
--- a/Makefile
+++ b/Makefile
@@ -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 $(wildcard *.d audio/*.d slirp/*.d)
diff --git a/configure b/configure
index c8868b7e2..b3d7fd864 100755
--- a/configure
+++ b/configure
@@ -1105,6 +1105,9 @@ echo "#define CONFIG_UNAME_RELEASE \"$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
diff --git a/exec-all.h b/exec-all.h
index 51b27b514..d1e581b10 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -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)
diff --git a/nbd.c b/nbd.c
new file mode 100644
index 000000000..fcf033929
--- /dev/null
+++ b/nbd.c
@@ -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;
+}
diff --git a/nbd.h b/nbd.h
new file mode 100644
index 000000000..5e583540a
--- /dev/null
+++ b/nbd.h
@@ -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
diff --git a/qemu-nbd.c b/qemu-nbd.c
new file mode 100644
index 000000000..3fb3d0c70
--- /dev/null
+++ b/qemu-nbd.c
@@ -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;
+}
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
new file mode 100644
index 000000000..7b6d0cbb5
--- /dev/null
+++ b/qemu-nbd.texi
@@ -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