summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--nbd.c74
-rw-r--r--nbd.h5
-rw-r--r--qemu-nbd.c139
-rw-r--r--qemu-nbd.texi6
4 files changed, 213 insertions, 11 deletions
diff --git a/nbd.c b/nbd.c
index c138d362e..9f8fda924 100644
--- a/nbd.c
+++ b/nbd.c
@@ -25,6 +25,7 @@
#include <ctype.h>
#include <inttypes.h>
#include <sys/socket.h>
+#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
@@ -183,6 +184,65 @@ error:
return -1;
}
+int unix_socket_incoming(const char *path)
+{
+ int s;
+ struct sockaddr_un addr;
+ int serrno;
+
+ s = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (s == -1) {
+ return -1;
+ }
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
+
+ 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;
+}
+
+int unix_socket_outgoing(const char *path)
+{
+ int s;
+ struct sockaddr_un addr;
+ int serrno;
+
+ s = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (s == -1) {
+ return -1;
+ }
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
+
+ if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+ goto error;
+ }
+
+ return s;
+error:
+ serrno = errno;
+ close(s);
+ errno = serrno;
+ return -1;
+}
+
+
/* Basic flow
Server Client
@@ -225,12 +285,10 @@ int nbd_negotiate(BlockDriverState *bs, int csock, off_t size)
return 0;
}
-int nbd_receive_negotiate(int fd, int csock)
+int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
{
char buf[8 + 8 + 8 + 128];
uint64_t magic;
- off_t size;
- size_t blocksize;
TRACE("Receiving negotation.");
@@ -241,8 +299,8 @@ int nbd_receive_negotiate(int fd, int csock)
}
magic = be64_to_cpup((uint64_t*)(buf + 8));
- size = be64_to_cpup((uint64_t*)(buf + 16));
- blocksize = 1024;
+ *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] : '.',
@@ -254,7 +312,7 @@ int nbd_receive_negotiate(int fd, int csock)
isprint(buf[6]) ? buf[6] : '.',
isprint(buf[7]) ? buf[7] : '.');
TRACE("Magic is 0x%" PRIx64, magic);
- TRACE("Size is %" PRIu64, size);
+ TRACE("Size is %" PRIu64, *size);
if (memcmp(buf, "NBDMAGIC", 8) != 0) {
LOG("Invalid magic received");
@@ -269,7 +327,11 @@ int nbd_receive_negotiate(int fd, int csock)
errno = EINVAL;
return -1;
}
+ return 0;
+}
+int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+{
TRACE("Setting block size to %lu", (unsigned long)blocksize);
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
diff --git a/nbd.h b/nbd.h
index 5e583540a..4bb185bf8 100644
--- a/nbd.h
+++ b/nbd.h
@@ -27,9 +27,12 @@
#include "block_int.h"
int tcp_socket_incoming(const char *address, uint16_t port);
+int unix_socket_outgoing(const char *path);
+int unix_socket_incoming(const char *path);
int nbd_negotiate(BlockDriverState *bs, int csock, off_t size);
-int nbd_receive_negotiate(int fd, int csock);
+int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize);
+int nbd_init(int fd, int csock, off_t size, size_t blocksize);
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);
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 0feafca08..3bcf87984 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1,4 +1,4 @@
-/*\
+/*
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
@@ -25,10 +25,14 @@
#include <stdio.h>
#include <getopt.h>
#include <err.h>
+#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
+#include <signal.h>
+
+#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
int verbose;
@@ -41,14 +45,18 @@ static void usage(const char *name)
" -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"
+" -k, --socket=PATH path to the unix socket\n"
+" (default '"SOCKET_PATH"')\n"
" -r, --read-only export read-only\n"
" -P, --partition=NUM only expose partition NUM\n"
+" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
+" -d, --disconnect disconnect the specified device\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);
+ , name, "DEVICE");
}
static void version(const char *name)
@@ -144,27 +152,51 @@ static int find_partition(BlockDriverState *bs, int partition,
return -1;
}
+static void show_parts(const char *device)
+{
+ if (fork() == 0) {
+ int nbd;
+
+ /* linux just needs an open() to trigger
+ * the partition table update
+ * but remember to load the module with max_part != 0 :
+ * modprobe nbd max_part=63
+ */
+ nbd = open(device, O_RDWR);
+ if (nbd != -1)
+ close(nbd);
+ exit(0);
+ }
+}
+
int main(int argc, char **argv)
{
BlockDriverState *bs;
off_t dev_offset = 0;
off_t offset = 0;
bool readonly = false;
+ bool disconnect = 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";
+ char *device = NULL;
+ char *socket = NULL;
+ char sockpath[128];
+ const char *sopt = "hVbo:p:rsP:c:dvk:";
struct option lopt[] = {
{ "help", 0, 0, 'h' },
{ "version", 0, 0, 'V' },
{ "bind", 1, 0, 'b' },
{ "port", 1, 0, 'p' },
+ { "socket", 1, 0, 'k' },
{ "offset", 1, 0, 'o' },
{ "read-only", 0, 0, 'r' },
{ "partition", 1, 0, 'P' },
+ { "connect", 1, 0, 'c' },
+ { "disconnect", 0, 0, 'd' },
{ "snapshot", 0, 0, 's' },
{ "verbose", 0, 0, 'v' },
{ NULL, 0, 0, 0 }
@@ -175,6 +207,8 @@ int main(int argc, char **argv)
char *end;
bool snapshot = false;
int partition = -1;
+ int fd;
+ int ret;
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
@@ -213,6 +247,17 @@ int main(int argc, char **argv)
if (partition < 1 || partition > 8)
errx(EINVAL, "Invalid partition %d", partition);
break;
+ case 'k':
+ socket = optarg;
+ if (socket[0] != '/')
+ errx(EINVAL, "socket path must be absolute\n");
+ break;
+ case 'd':
+ disconnect = true;
+ break;
+ case 'c':
+ device = optarg;
+ break;
case 'v':
verbose = 1;
break;
@@ -236,6 +281,20 @@ int main(int argc, char **argv)
argv[0]);
}
+ if (disconnect) {
+ fd = open(argv[optind], O_RDWR);
+ if (fd == -1)
+ errx(errno, "Cannot open %s", argv[optind]);
+
+ nbd_disconnect(fd);
+
+ close(fd);
+
+ printf("%s disconnected\n", argv[optind]);
+
+ return 0;
+ }
+
bdrv_init();
bs = bdrv_new("hda");
@@ -251,7 +310,77 @@ int main(int argc, char **argv)
find_partition(bs, partition, &dev_offset, &fd_size))
errx(errno, "Could not find partition %d", partition);
- sock = tcp_socket_incoming(bindto, port);
+ if (device) {
+ pid_t pid;
+ if (!verbose)
+ daemon(0, 0); /* detach client and server */
+
+ if (socket == NULL) {
+ sprintf(sockpath, SOCKET_PATH, basename(device));
+ socket = sockpath;
+ }
+
+ pid = fork();
+ if (pid < 0)
+ return 1;
+ if (pid != 0) {
+ off_t size;
+ size_t blocksize;
+
+ ret = 0;
+ bdrv_close(bs);
+
+ do {
+ sock = unix_socket_outgoing(socket);
+ if (sock == -1) {
+ if (errno != ENOENT && errno != ECONNREFUSED)
+ goto out;
+ sleep(1); /* wait children */
+ }
+ } while (sock == -1);
+
+ fd = open(device, O_RDWR);
+ if (fd == -1) {
+ ret = 1;
+ goto out;
+ }
+
+ ret = nbd_receive_negotiate(sock, &size, &blocksize);
+ if (ret == -1) {
+ ret = 1;
+ goto out;
+ }
+
+ ret = nbd_init(fd, sock, size, blocksize);
+ if (ret == -1) {
+ ret = 1;
+ goto out;
+ }
+
+ printf("NBD device %s is now connected to file %s\n",
+ device, argv[optind]);
+
+ /* update partition table */
+
+ show_parts(device);
+
+ nbd_client(fd, sock);
+ close(fd);
+ out:
+ kill(pid, SIGTERM);
+ unlink(socket);
+
+ return ret;
+ }
+ /* children */
+ }
+
+ if (socket) {
+ sock = unix_socket_incoming(socket);
+ } else {
+ sock = tcp_socket_incoming(bindto, port);
+ }
+
if (sock == -1)
return 1;
@@ -270,6 +399,8 @@ int main(int argc, char **argv)
close(csock);
close(sock);
bdrv_close(bs);
+ if (socket)
+ unlink(socket);
return 0;
}
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 7b6d0cbb5..37b68f5fc 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -20,10 +20,16 @@ Export Qemu disk image using NBD protocol.
offset into the image
@item -b, --bind=IFACE
interface to bind to (default `0.0.0.0')
+@item -k, --socket=PATH
+ Use a unix socket with path PATH
@item -r, --read-only
export read-only
@item -P, --partition=NUM
only expose partition NUM
+@item -c, --connect
+ connect FILE to NBD device DEV
+@item -d, --disconnect
+ disconnect the specified device
@item -v, --verbose
display extra debugging information
@item -h, --help