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#define _GNU_SOURCE
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <string.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/signal.h>
#include <xs.h>
#include "mdns-publish.h"
/* --------------------------------------------------------------------- */
static struct xs_handle *xenstore;
static int debug = 0;
static char *appname = "mdns-publish-xendom";
static struct utsname uts;
static char *service = "_xendom._tcp";
static int port = 9;
static char vm_uuid[256];
static char dom_id[256];
static struct mdns_pub *mdns;
static struct mdns_pub_entry *entry;
/* --------------------------------------------------------------------- */
static int xen_init(void)
{
struct stat st;
if (-1 == stat("/proc/xen", &st)) {
mdns_log_printf(mdns, LOG_ERR,
"/proc/xen not found, running on bare metal?\n");
return -1;
}
xenstore = xs_domain_open();
if (NULL == xenstore) {
mdns_log_printf(mdns, LOG_ERR,
"can't connect to xenstore (%s)\n", xs_domain_dev());
return -1;
}
return 0;
}
static int xen_get_info(void)
{
xs_transaction_t xst;
char *xs_value;
if (!(xst = xs_transaction_start(xenstore))) {
mdns_log_printf(mdns, LOG_ERR, "can't start xenstore transaction\n");
goto out;
}
xs_value = xs_read(xenstore, xst, "vm", NULL);
xs_transaction_end(xenstore, xst, 0);
if (!xs_value) {
mdns_log_printf(mdns, LOG_ERR, "can't read 'vm' value from xenstore\n");
goto out;
}
snprintf(vm_uuid, sizeof(vm_uuid), "vm-uuid=%s", xs_value+4);
if (!(xst = xs_transaction_start(xenstore))) {
mdns_log_printf(mdns, LOG_ERR, "can't start xenstore transaction\n");
goto out;
}
xs_value = xs_read(xenstore, xst, "domid", NULL);
xs_transaction_end(xenstore, xst, 0);
if (!xs_value) {
mdns_log_printf(mdns, LOG_ERR, "can't read 'domid' value from xenstore\n");
goto out;
}
snprintf(dom_id, sizeof(dom_id), "dom-id=%s", xs_value);
return 0;
out:
return -1;
}
static int xen_watch_add(char *path)
{
int ret = 0;
/* Hmm, not working ... */
if (!xs_watch(xenstore, path, "token")) {
mdns_log_printf(mdns, LOG_ERR, "%s: xs_watch for \"%s\" failed\n",
__FUNCTION__, path);
ret = -1;
}
return ret;
}
static int xen_publish(void)
{
static int count = 1;
char buf[128];
if (debug)
snprintf(buf, sizeof(buf), "Xen domain %s (%d)", uts.nodename, count++);
else
snprintf(buf, sizeof(buf), "Xen domain %s", uts.nodename);
if (entry)
mdns_pub_del(entry);
entry = mdns_pub_add(mdns, buf, service, port,
vm_uuid, dom_id, NULL);
return 0;
}
static int xen_watch_data(void)
{
char **vec = NULL;
unsigned int count;
vec = xs_read_watch(xenstore, &count);
mdns_log_printf(mdns, LOG_DEBUG, "%s: \"%s\"\n", __FUNCTION__, vec[XS_WATCH_PATH]);
xen_get_info();
xen_publish();
if (vec)
free(vec);
return 0;
}
/* --------------------------------------------------------------------- */
static void usage(FILE *fp)
{
fprintf(fp,
"This little daemon publishes xen domain info,\n"
"via mDNS (using avahi), as service '_xendom._tcp'.\n"
"\n"
"usage: %s [options]\n"
"options:\n"
" -h print this text\n"
" -d enable debug mode\n"
"\n"
"-- \n"
"(c) 2006 Gerd Hoffmann <kraxel@redhat.com>\n",
appname);
}
static int wait_fd(int fd, int secs)
{
struct timeval tv;
fd_set rd;
int rc;
FD_ZERO(&rd);
FD_SET(fd,&rd);
tv.tv_sec = secs;
tv.tv_usec = 0;
rc = select(fd+1, &rd, NULL, NULL, &tv);
if (-1 == rc) {
if (EINTR == errno)
return 0;
}
return rc;
}
int main(int argc, char*argv[])
{
int ret = 1;
int c;
/* parse options */
for (;;) {
if (-1 == (c = getopt(argc, argv, "hd")))
break;
switch (c) {
case 'd':
debug = 1;
break;
case 'h':
usage(stdout);
exit(0);
default:
usage(stderr);
exit(1);
}
}
/* figure name */
uname(&uts);
mdns_pub_appname = appname;
if (!debug)
mdns_daemonize();
mdns = mdns_pub_init(debug);
if (NULL == mdns)
goto fail;
mdns_sigsetup(mdns);
/* figure domain info */
if (0 != xen_init())
goto fail;
xen_get_info();
xen_watch_add("vm");
xen_watch_add("domid");
/* enter main loop */
ret = 0;
mdns_pub_start(mdns);
xen_publish();
for (;;) {
if (mdns_pub_appquit)
break;
switch (wait_fd(xs_fileno(xenstore),1)) {
case -1:
mdns_log_printf(mdns, LOG_ERR, "select: %s\n", strerror(errno));
mdns_pub_appquit = 1;
case 0:
/* timeout */
break;
default:
/* data to read */
xen_watch_data();
}
}
mdns_pub_del_all(mdns);
mdns_pub_stop(mdns);
fail:
mdns_log_printf(mdns, ret ? LOG_ERR : LOG_INFO, "exiting (%d)%s%s\n", ret,
mdns_pub_termsig ? ", on signal " : "",
mdns_pub_termsig ? strsignal(mdns_pub_termsig) : "");
mdns_pub_fini(mdns);
return ret;
}
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