aboutsummaryrefslogtreecommitdiff
path: root/qemu-nbd.c
diff options
context:
space:
mode:
Diffstat (limited to 'qemu-nbd.c')
-rw-r--r--qemu-nbd.c270
1 files changed, 223 insertions, 47 deletions
diff --git a/qemu-nbd.c b/qemu-nbd.c
index ff11cdc4b..45464a0c8 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1,4 +1,4 @@
-/*\
+/*
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
@@ -21,44 +21,22 @@
#include "block_int.h"
#include "nbd.h"
-#include <malloc.h>
#include <stdarg.h>
#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>
-int verbose;
-
-#ifdef _WIN32
-
-void *qemu_memalign(size_t alignment, size_t size)
-{
- return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
-}
-
-#else
+#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
-void *qemu_memalign(size_t alignment, size_t size)
-{
-#if defined(_POSIX_C_SOURCE)
- int ret;
- void *ptr;
- ret = posix_memalign(&ptr, alignment, size);
- if (ret != 0)
- return NULL;
- return ptr;
-#elif defined(_BSD)
- return valloc(size);
-#else
- return memalign(alignment, size);
-#endif
-}
+#define NBD_BUFFER_SIZE (1024*1024)
-#endif
+int verbose;
static void usage(const char *name)
{
@@ -69,14 +47,22 @@ 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"
+" -s, --snapshot use snapshot file\n"
+" -n, --nocache disable host cache\n"
+" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
+" -d, --disconnect disconnect the specified device\n"
+" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
+" -t, --persistent don't exit on the last connection\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)
@@ -172,41 +158,81 @@ 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:rsnP:c:dvk:e:t";
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' },
+ { "nocache", 0, 0, 'n' },
+ { "shared", 1, 0, 'e' },
+ { "persistent", 0, 0, 't' },
{ "verbose", 0, 0, 'v' },
+ { NULL, 0, 0, 0 }
};
int ch;
int opt_ind = 0;
int li;
char *end;
- bool snapshot = false;
+ int flags = 0;
int partition = -1;
+ int ret;
+ int shared = 1;
+ uint8_t *data;
+ fd_set fds;
+ int *sharing_fds;
+ int fd;
+ int i;
+ int nb_fds = 0;
+ int max_fd;
+ int persistent = 0;
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 's':
- snapshot = true;
+ flags |= BDRV_O_SNAPSHOT;
+ break;
+ case 'n':
+ flags |= BDRV_O_DIRECT;
break;
case 'b':
bindto = optarg;
@@ -240,6 +266,29 @@ 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 'e':
+ shared = strtol(optarg, &end, 0);
+ if (*end) {
+ errx(EINVAL, "Invalid shared device number '%s'", optarg);
+ }
+ if (shared < 1) {
+ errx(EINVAL, "Shared device number must be greater than 0\n");
+ }
+ break;
+ case 't':
+ persistent = 1;
+ break;
case 'v':
verbose = 1;
break;
@@ -263,13 +312,27 @@ 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");
if (bs == NULL)
return 1;
- if (bdrv_open(bs, argv[optind], snapshot) == -1)
+ if (bdrv_open(bs, argv[optind], flags) == -1)
return 1;
fd_size = bs->total_sectors * 512;
@@ -278,25 +341,138 @@ 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 (sock == -1)
- return 1;
+ if (device) {
+ pid_t pid;
+ int sock;
- csock = accept(sock,
- (struct sockaddr *)&addr,
- &addr_len);
- if (csock == -1)
- return 1;
+ if (!verbose)
+ daemon(0, 0); /* detach client and server */
- /* new fd_size is calculated by find_partition */
- if (nbd_negotiate(bs, csock, fd_size) == -1)
+ 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 */
+ }
+
+ sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
+ if (sharing_fds == NULL)
+ errx(ENOMEM, "Cannot allocate sharing fds");
+
+ if (socket) {
+ sharing_fds[0] = unix_socket_incoming(socket);
+ } else {
+ sharing_fds[0] = tcp_socket_incoming(bindto, port);
+ }
+
+ if (sharing_fds[0] == -1)
return 1;
+ max_fd = sharing_fds[0];
+ nb_fds++;
- while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly) == 0);
+ data = qemu_memalign(512, NBD_BUFFER_SIZE);
+ if (data == NULL)
+ errx(ENOMEM, "Cannot allocate data buffer");
+
+ do {
+
+ FD_ZERO(&fds);
+ for (i = 0; i < nb_fds; i++)
+ FD_SET(sharing_fds[i], &fds);
+
+ ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
+ if (ret == -1)
+ break;
+
+ if (FD_ISSET(sharing_fds[0], &fds))
+ ret--;
+ for (i = 1; i < nb_fds && ret; i++) {
+ if (FD_ISSET(sharing_fds[i], &fds)) {
+ if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset,
+ &offset, readonly, data, NBD_BUFFER_SIZE) != 0) {
+ close(sharing_fds[i]);
+ nb_fds--;
+ sharing_fds[i] = sharing_fds[nb_fds];
+ i--;
+ }
+ ret--;
+ }
+ }
+ /* new connection ? */
+ if (FD_ISSET(sharing_fds[0], &fds)) {
+ if (nb_fds < shared + 1) {
+ sharing_fds[nb_fds] = accept(sharing_fds[0],
+ (struct sockaddr *)&addr,
+ &addr_len);
+ if (sharing_fds[nb_fds] != -1 &&
+ nbd_negotiate(bs, sharing_fds[nb_fds], fd_size) != -1) {
+ if (sharing_fds[nb_fds] > max_fd)
+ max_fd = sharing_fds[nb_fds];
+ nb_fds++;
+ }
+ }
+ }
+ } while (persistent || nb_fds > 1);
+ qemu_free(data);
- close(csock);
- close(sock);
+ close(sharing_fds[0]);
bdrv_close(bs);
+ qemu_free(sharing_fds);
+ if (socket)
+ unlink(socket);
return 0;
}