- add xenstore watch.

1 files changed, 80 insertions, 19 deletions

diff --git a/mdns-publish-xendom.c b/mdns-publish-xendom.c
index 48bf2bd..1a16384 100644
--- a/mdns-publish-xendom.c
+++ b/mdns-publish-xendom.c
@@ -8,6 +8,7 @@
 #include <sys/types.h>
 #include <sys/utsname.h>
 #include <sys/stat.h>
+#include <sys/select.h>
 
 #include <xs.h>
 
@@ -15,19 +16,22 @@
 #include <avahi-client/publish.h>
 
 #include <avahi-common/alternative.h>
-#include <avahi-common/simple-watch.h>
+#include <avahi-common/thread-watch.h>
 #include <avahi-common/malloc.h>
 #include <avahi-common/error.h>
 
 /* --------------------------------------------------------------------- */
 
-static AvahiEntryGroup *group = NULL;
-static AvahiSimplePoll *simple_poll = NULL;
+static AvahiEntryGroup    *group = NULL;
+static AvahiThreadedPoll  *thread_poll = NULL;
+
+static struct xs_handle *xenstore;
 
 static int  debug        = 0;
 static int  have_tty     = 1;
 static int  have_syslog  = 0;
 static char *appname     = "mdns-publish-xendom";
+static int  app_quit     = 0;
 
 static char *name;
 static char *service     = "_xendom._tcp";
@@ -78,7 +82,7 @@ static void entry_group_callback(AvahiEntryGroup *g,
 	create_services(avahi_entry_group_get_client(g));
 	break;
     case AVAHI_ENTRY_GROUP_FAILURE:
-	avahi_simple_poll_quit(simple_poll);
+	app_quit = 1;
 	break;
     default:
 	break;
@@ -115,7 +119,7 @@ static void create_services(AvahiClient *c)
     return;
 
 fail:
-    avahi_simple_poll_quit(simple_poll);
+    app_quit = 1;
 }
 
 static void client_callback(AvahiClient *c,
@@ -144,7 +148,7 @@ static void client_callback(AvahiClient *c,
 	    group = NULL;
 
 	    log_printf(LOG_NOTICE, "disconnected from avahi daemon, reconnecting ...\n");
-	    c = avahi_client_new(avahi_simple_poll_get(simple_poll),
+	    c = avahi_client_new(avahi_threaded_poll_get(thread_poll),
 				 AVAHI_CLIENT_NO_FAIL,
 				 client_callback, NULL, &error);
 	    if (!c) {
@@ -166,14 +170,13 @@ static void client_callback(AvahiClient *c,
     return;
 
  fail:
-    avahi_simple_poll_quit(simple_poll);
+    app_quit = 1;
 }
 
-static int update_xendom_info(void)
+/* --------------------------------------------------------------------- */
+
+static int xen_init(void)
 {
-    struct xs_handle *xenstore;
-    xs_transaction_t xst;
-    char *xs_value;
     struct stat st;
 
     if (-1 == stat("/proc/xen", &st)) {
@@ -187,6 +190,16 @@ static int update_xendom_info(void)
 	return -1;
     }
 
+    xs_watch(xenstore, "vm",    "token");
+    xs_watch(xenstore, "domid", "token");
+    return 0;
+}
+
+static int xen_get_info(void)
+{
+    xs_transaction_t xst;
+    char *xs_value;
+
     if (!(xst = xs_transaction_start(xenstore))) {
 	log_printf(LOG_ERR, "can't start xenstore transaction\n");
 	goto out;
@@ -217,6 +230,21 @@ static int update_xendom_info(void)
     return -1;
 }
 
+static int xen_watch(void)
+{
+    char **vec = NULL;
+    unsigned int count;
+    
+    vec = xs_read_watch(xenstore, &count);
+    log_printf(LOG_DEBUG, "%s: \"%s\"\n", __FUNCTION__, vec[XS_WATCH_PATH]);
+
+    if (vec)
+	free(vec);
+    return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
 static void usage(FILE *fp)
 {
     fprintf(fp,
@@ -233,6 +261,20 @@ static void usage(FILE *fp)
 	    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);
+    return rc;
+}
+
 int main(int argc, char*argv[])
 {
     AvahiClient *client = NULL;
@@ -268,17 +310,18 @@ int main(int argc, char*argv[])
     name = avahi_strdup(buf);
 
     /* figure domain info */
-    if (0 != update_xendom_info())
+    if (0 != xen_init())
 	goto fail;
+    xen_get_info();
     
     /* prepare nDNS bits */
-    simple_poll = avahi_simple_poll_new();
-    if (!simple_poll) {
+    thread_poll = avahi_threaded_poll_new();
+    if (!thread_poll) {
         log_printf(LOG_ERR, "failed to create simple poll object\n");
         goto fail;
     }
     
-    client = avahi_client_new(avahi_simple_poll_get(simple_poll),
+    client = avahi_client_new(avahi_threaded_poll_get(thread_poll),
 			      AVAHI_CLIENT_NO_FAIL,
 			      client_callback, NULL, &error);
     if (!client) {
@@ -305,9 +348,27 @@ int main(int argc, char*argv[])
         }
    }
 
-    /* go ahead */
-    avahi_simple_poll_loop(simple_poll);
+    /* enter main loop */
     ret = 0;
+    avahi_threaded_poll_start(thread_poll);
+
+    for (;;) {
+	if (app_quit)
+	    break;
+	switch (wait_fd(xs_fileno(xenstore),1)) {
+	case -1:
+            log_printf(LOG_ERR, "select: %s", strerror(errno));
+	    app_quit = 1;
+	case 0:
+	    /* timeout */
+	    break;
+	default:
+	    /* data to read */
+	    xen_watch();
+	}
+    }
+
+    avahi_threaded_poll_stop(thread_poll);
     
 fail:
     log_printf(ret ? LOG_ERR : LOG_INFO, "exiting (%d)\n", ret);
@@ -316,8 +377,8 @@ fail:
     if (client)
         avahi_client_free(client);
 
-    if (simple_poll)
-        avahi_simple_poll_free(simple_poll);
+    if (thread_poll)
+        avahi_threaded_poll_free(thread_poll);
 
     avahi_free(name);
     return ret;