- add xenstuff to mdns bits.

1 files changed, 86 insertions, 29 deletions

diff --git a/mdns-publish-xendom.c b/mdns-publish-xendom.c
index f2be81f..69eccb4 100644
--- a/mdns-publish-xendom.c
+++ b/mdns-publish-xendom.c
@@ -3,6 +3,8 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <syslog.h>
+#include <string.h>
 #include <sys/utsname.h>
 
 #include <xs.h>
@@ -18,13 +20,38 @@
 static AvahiEntryGroup *group = NULL;
 static AvahiSimplePoll *simple_poll = NULL;
 
-static int  debug = 0;
+static int  debug        = 0;
+static int  have_tty     = 1;
+static int  have_syslog  = 0;
+
 static char *name;
-static char *service = "_xendom._tcp";
-static int  port     = 9;
+static char *service     = "_xendom._tcp";
+static int  port         = 9;
 static char vm_uuid[256];
 static char dom_id[256];
 
+/* --------------------------------------------------------------------- */
+
+static int __attribute__ ((format (printf, 2, 0)))
+log_printf(int priority, char *fmt, ...)
+{
+    va_list args;
+    char msgbuf[1024];
+    int rc;
+
+    va_start(args, fmt);
+    rc = vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
+    va_end(args);
+
+    if (have_tty)
+	fprintf(stderr, "%s", msgbuf);
+    if (have_syslog)
+	syslog(priority, "%s", msgbuf);
+    return rc;
+}
+
+/* --------------------------------------------------------------------- */
+
 static void create_services(AvahiClient *c);
 
 static void entry_group_callback(AvahiEntryGroup *g,
@@ -35,15 +62,14 @@ static void entry_group_callback(AvahiEntryGroup *g,
 
     switch (state) {
     case AVAHI_ENTRY_GROUP_ESTABLISHED:
-	if (debug)
-	    fprintf(stderr, "Service '%s' successfully established.\n", name);
+	log_printf(LOG_INFO, "Service '%s' successfully established.\n", name);
 	break;
     case AVAHI_ENTRY_GROUP_COLLISION:
 	n = avahi_alternative_service_name(name);
+	log_printf(LOG_NOTICE, "Service name collision, renaming '%s' to '%s'\n",
+		   name, n);
 	avahi_free(name);
 	name = n;
-	if (debug)
-	    fprintf(stderr, "Service name collision, renaming service to '%s'\n", name);
 	create_services(avahi_entry_group_get_client(g));
 	break;
     case AVAHI_ENTRY_GROUP_FAILURE :
@@ -61,9 +87,8 @@ static void create_services(AvahiClient *c)
     /* If this is the first time we're called, let's create a new entry group */
     if (!group) {
         if (!(group = avahi_entry_group_new(c, entry_group_callback, NULL))) {
-	    if (debug)
-		fprintf(stderr, "avahi_entry_group_new() failed: %s\n",
-			avahi_strerror(avahi_client_errno(c)));
+	    log_printf(LOG_ERR, "avahi_entry_group_new() failed: %s\n",
+		       avahi_strerror(avahi_client_errno(c)));
             goto fail;
         }
     }
@@ -73,15 +98,13 @@ static void create_services(AvahiClient *c)
 					name, service, NULL, NULL, port,
 					vm_uuid, dom_id, NULL);
     if (ret < 0) {
-	if (debug)
-	    fprintf(stderr, "Failed to add %s service: %s\n", service, avahi_strerror(ret));
+	log_printf(LOG_ERR, "Failed to add '%s' service: %s\n", service, avahi_strerror(ret));
         goto fail;
     }
 
     /* Tell the server to register the service */
     if ((ret = avahi_entry_group_commit(group)) < 0) {
-	if (debug)
-	    fprintf(stderr, "Failed to commit entry_group: %s\n", avahi_strerror(ret));
+	log_printf(LOG_ERR, "Failed to commit entry_group: %s\n", avahi_strerror(ret));
         goto fail;
     }
     return;
@@ -94,7 +117,12 @@ static void client_callback(AvahiClient *c,
 			    AvahiClientState state,
 			    void * userdata)
 {
+    int error;
+    
     switch (state) {
+    case AVAHI_CLIENT_CONNECTING:
+	log_printf(LOG_NOTICE, "avahi not running (yet), I'll keep trying ...\n");
+	break;
     case AVAHI_CLIENT_S_RUNNING:
 	if (!group)
 	    create_services(c);
@@ -104,16 +132,39 @@ static void client_callback(AvahiClient *c,
 	    avahi_entry_group_reset(group);
 	break;
     case AVAHI_CLIENT_FAILURE:
-	if (debug)
-	    fprintf(stderr, "Client failure: %s\n", avahi_strerror(avahi_client_errno(c)));
-	avahi_simple_poll_quit(simple_poll);
+	switch (avahi_client_errno(c)) {
+	case AVAHI_ERR_DISCONNECTED:
+	    avahi_entry_group_free(group);
+	    avahi_client_free(c);
+	    group = NULL;
+
+	    log_printf(LOG_NOTICE, "disconnected from avahi, reconnecting ...\n");
+	    c = avahi_client_new(avahi_simple_poll_get(simple_poll),
+				 AVAHI_CLIENT_NO_FAIL,
+				 client_callback, NULL, &error);
+	    if (!c) {
+		log_printf(LOG_ERR, "Failed to create client: %s\n",
+			   avahi_strerror(error));
+		goto fail;
+	    }
+	    break;
+	default:
+	    log_printf(LOG_ERR, "Client failure: %s\n",
+		       avahi_strerror(avahi_client_errno(c)));
+	    goto fail;
+	    break;
+	}
 	break;
     default:
 	break;
     }
+    return;
+
+ fail:
+    avahi_simple_poll_quit(simple_poll);
 }
 
-static int xendom_info(void)
+static int update_xendom_info(void)
 {
     struct xs_handle *xenstore;
     xs_transaction_t xst;
@@ -121,31 +172,31 @@ static int xendom_info(void)
 
     xenstore = xs_domain_open();
     if (NULL == xenstore) {
-	fprintf(stderr,"%s: can't connect to %s\n", __FUNCTION__,
-		xs_domain_dev());
+	log_printf(LOG_ERR, "%s: can't connect to %s\n", __FUNCTION__,
+		   xs_domain_dev());
 	return -1;
     }
 
     if (!(xst = xs_transaction_start(xenstore))) {
-	fprintf(stderr,"%s: can't start transaction\n", __FUNCTION__);
+	log_printf(LOG_ERR, "%s: can't start transaction\n", __FUNCTION__);
 	goto out;
     }
     xs_value = xs_read(xenstore, xst, "vm", NULL);
     xs_transaction_end(xenstore, xst, 0);
     if (!xs_value) {
-	fprintf(stderr,"%s: can't read \"vm\" value\n", __FUNCTION__);
+	log_printf(LOG_ERR, "%s: can't read \"vm\" value\n", __FUNCTION__);
 	goto out;
     }
     snprintf(vm_uuid, sizeof(vm_uuid), "vm-uuid=%s", xs_value+4);
 
     if (!(xst = xs_transaction_start(xenstore))) {
-	fprintf(stderr,"%s: can't start transaction\n", __FUNCTION__);
+	log_printf(LOG_ERR, "%s: can't start transaction\n", __FUNCTION__);
 	goto out;
     }
     xs_value = xs_read(xenstore, xst, "domid", NULL);
     xs_transaction_end(xenstore, xst, 0);
     if (!xs_value) {
-	fprintf(stderr,"%s: can't read \"domid\" value\n", __FUNCTION__);
+	log_printf(LOG_ERR, "%s: can't read \"domid\" value\n", __FUNCTION__);
 	goto out;
     }
     snprintf(dom_id,  sizeof(dom_id), "dom-id=%s", xs_value);
@@ -195,26 +246,31 @@ int main(int argc, char*argv[])
         }
     }
 
+    /* open syslog */
+    openlog("mdns-publish-xendom", 0, LOG_LOCAL0);
+    have_syslog = 1;
+
     /* figure name */
     uname(&uts);
     snprintf(buf, sizeof(buf), "Xen domain %s", uts.nodename);
     name = avahi_strdup(buf);
 
     /* figure domain info */
-    if (0 != xendom_info())
+    if (0 != update_xendom_info())
 	exit(1);
     
     /* prepare nDNS bits */
     simple_poll = avahi_simple_poll_new();
     if (!simple_poll) {
-        fprintf(stderr, "Failed to create simple poll object.\n");
+        log_printf(LOG_ERR, "Failed to create simple poll object.\n");
         goto fail;
     }
     
-    client = avahi_client_new(avahi_simple_poll_get(simple_poll), 0,
+    client = avahi_client_new(avahi_simple_poll_get(simple_poll),
+			      AVAHI_CLIENT_NO_FAIL,
 			      client_callback, NULL, &error);
     if (!client) {
-        fprintf(stderr, "Failed to create client: %s\n", avahi_strerror(error));
+        log_printf(LOG_ERR, "Failed to create client: %s\n", avahi_strerror(error));
         goto fail;
     }
 
@@ -222,12 +278,13 @@ int main(int argc, char*argv[])
     if (!debug) {
 	switch (fork()) {
         case -1:
-            perror("fork");
+            log_printf(LOG_ERR, "fork: %s", strerror(errno));
             exit(1);
         case 0:
             close(0); close(1); close(2);
             setsid();
             open("/dev/null", O_RDWR); dup(0); dup(0);
+	    have_tty = 0;
             break;
         default:
             exit(0);