From: Chaos Eternal <ch...@shlug.org>
run qemu-nbd as an inetd service has some benefits
* more scriptable, such as serve multiple images to different clients
on one ip/port
* access control using tcpd
simple usage:
#!/bin/sh
# qemu-nbd wrapper, select image file according to client ip address
IMG_FILE=`sed -n "s/$REMOTE_HOST //p" /path/to/image_list.txt`
qemu-nbd -i 10 $IMG_FILE 10<&0- 1>/tmp/log 2>/tmp/log2
#end
#xinetd.conf
service nbd
{
flags = REUSE
socket_type = stream
wait = no
user = some_user
server = /path/to/qemu-nbd-wrapper.sh
log_on_failure += USERID
disable = no
}
Signed-off-by: Jun Sheng <chaoseter...@gmail.com>
---
qemu-nbd.c | 40 +++++++++++++++++++++++++++++++++-------
1 file changed, 33 insertions(+), 7 deletions(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index b524b34..13695e9 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -49,6 +49,7 @@ static NBDExport *exp;
static int verbose;
static char *srcpath;
static char *sockpath;
+static int use_inetd = 0;
static int persistent = 0;
static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;
static int shared = 1;
@@ -66,6 +67,7 @@ static void usage(const char *name)
"Connection properties:\n"
" -p, --port=PORT port to listen on (default `%d')\n"
" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
+" -i, --inetd=FD run as an inetd services on FD\n"
" -k, --socket=PATH path to the unix socket\n"
" (default '"SOCKET_PATH"')\n"
" -e, --shared=NUM device can be shared by NUM clients (default
'1')\n"
@@ -363,7 +365,13 @@ static void nbd_accept(void *opaque)
struct sockaddr_in addr;
socklen_t addr_len = sizeof(addr);
- int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
+
+ int fd ;
+ if (use_inetd == 0)
+ fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
+ else
+ fd = server_fd;
+
if (fd < 0) {
perror("accept");
return;
@@ -395,10 +403,11 @@ int main(int argc, char **argv)
off_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
- const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:";
+ const char *sopt = "hVi:b:o:p:rsnP:c:dvk:e:f:tl:";
struct option lopt[] = {
{ "help", 0, NULL, 'h' },
{ "version", 0, NULL, 'V' },
+ { "inetd", 1, NULL, 'i'},
{ "bind", 1, NULL, 'b' },
{ "port", 1, NULL, 'p' },
{ "socket", 1, NULL, 'k' },
@@ -430,6 +439,7 @@ int main(int argc, char **argv)
int partition = -1;
int ret;
int fd;
+ int inet_fd = 10;
bool seen_cache = false;
bool seen_discard = false;
#ifdef CONFIG_LINUX_AIO
@@ -510,6 +520,16 @@ int main(int argc, char **argv)
case 'b':
bindto = optarg;
break;
+ case 'i':
+ use_inetd = 1;
+ inet_fd = strtol(optarg, &end, 0);
+ if (*end) {
+ errx(EXIT_FAILURE, "Invalid inet fd `%s'", optarg);
+ }
+ if (inet_fd < 3 || inet_fd > 65535) {
+ errx(EXIT_FAILURE, "Inet fd out of range `%s', should be in
[3, 65535]", optarg);
+ }
+ break;
case 'p':
li = strtol(optarg, &end, 0);
if (*end) {
@@ -729,11 +749,15 @@ int main(int argc, char **argv)
}
exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed);
-
- if (sockpath) {
+
+ if (use_inetd == 0) {
+ if (sockpath) {
fd = unix_socket_incoming(sockpath);
- } else {
+ } else {
fd = tcp_socket_incoming(bindto, port);
+ }
+ } else {
+ fd = inet_fd;
}
if (fd < 0) {
@@ -752,9 +776,11 @@ int main(int argc, char **argv)
/* Shut up GCC warnings. */
memset(&client_thread, 0, sizeof(client_thread));
}
-
- qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
+ if (use_inetd == 0)
+ qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
(void *)(uintptr_t)fd);
+ else
+ nbd_accept((void *) (uintptr_t) fd);
/* now when the initialization is (almost) complete, chdir("/")
* to free any busy filesystems */
--
2.1.2
