- mdns server first cut done.

1 files changed, 96 insertions, 25 deletions

diff --git a/mdns-publish-xendom.c b/mdns-publish-xendom.c
index 3d69ab6..f2be81f 100644
--- a/mdns-publish-xendom.c
+++ b/mdns-publish-xendom.c
@@ -1,6 +1,8 @@
 #include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
 #include <sys/utsname.h>
 
 #include <xs.h>
@@ -16,9 +18,12 @@
 static AvahiEntryGroup *group = NULL;
 static AvahiSimplePoll *simple_poll = NULL;
 
+static int  debug = 0;
 static char *name;
 static char *service = "_xendom._tcp";
 static int  port     = 9;
+static char vm_uuid[256];
+static char dom_id[256];
 
 static void create_services(AvahiClient *c);
 
@@ -30,13 +35,15 @@ static void entry_group_callback(AvahiEntryGroup *g,
 
     switch (state) {
     case AVAHI_ENTRY_GROUP_ESTABLISHED:
-	fprintf(stderr, "Service '%s' successfully established.\n", name);
+	if (debug)
+	    fprintf(stderr, "Service '%s' successfully established.\n", name);
 	break;
     case AVAHI_ENTRY_GROUP_COLLISION:
 	n = avahi_alternative_service_name(name);
 	avahi_free(name);
 	name = n;
-	fprintf(stderr, "Service name collision, renaming service to '%s'\n", name);
+	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 :
@@ -49,35 +56,32 @@ static void entry_group_callback(AvahiEntryGroup *g,
 
 static void create_services(AvahiClient *c)
 {
-    char r[128];
     int ret;
 
     /* 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))) {
-            fprintf(stderr, "avahi_entry_group_new() failed: %s\n",
-		    avahi_strerror(avahi_client_errno(c)));
+	    if (debug)
+		fprintf(stderr, "avahi_entry_group_new() failed: %s\n",
+			avahi_strerror(avahi_client_errno(c)));
             goto fail;
         }
     }
     
-    fprintf(stderr, "Adding service '%s'\n", name);
-    
-    /* Create some random TXT data */
-    snprintf(r, sizeof(r), "random=%i", rand());
-
-    /* Add the service for IPP */
+    /* Add the service */
     ret = avahi_entry_group_add_service(group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0,
 					name, service, NULL, NULL, port,
-					"test=blah", r, NULL);
+					vm_uuid, dom_id, NULL);
     if (ret < 0) {
-        fprintf(stderr, "Failed to add %s service: %s\n", service, avahi_strerror(ret));
+	if (debug)
+	    fprintf(stderr, "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) {
-        fprintf(stderr, "Failed to commit entry_group: %s\n", avahi_strerror(ret));
+	if (debug)
+	    fprintf(stderr, "Failed to commit entry_group: %s\n", avahi_strerror(ret));
         goto fail;
     }
     return;
@@ -100,7 +104,8 @@ static void client_callback(AvahiClient *c,
 	    avahi_entry_group_reset(group);
 	break;
     case AVAHI_CLIENT_FAILURE:
-	fprintf(stderr, "Client failure: %s\n", avahi_strerror(avahi_client_errno(c)));
+	if (debug)
+	    fprintf(stderr, "Client failure: %s\n", avahi_strerror(avahi_client_errno(c)));
 	avahi_simple_poll_quit(simple_poll);
 	break;
     default:
@@ -108,30 +113,61 @@ static void client_callback(AvahiClient *c,
     }
 }
 
-static void xendom_info(void)
+static int xendom_info(void)
 {
     struct xs_handle *xenstore;
-    struct xs_transaction_handle *xst;
+    xs_transaction_t xst;
     char *xs_value;
 
     xenstore = xs_domain_open();
     if (NULL == xenstore) {
 	fprintf(stderr,"%s: can't connect to %s\n", __FUNCTION__,
 		xs_domain_dev());
-	return;
+	return -1;
     }
 
-    if (NULL == (xst = xs_transaction_start(xenstore)))
+    if (!(xst = xs_transaction_start(xenstore))) {
+	fprintf(stderr,"%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)
+    if (!xs_value) {
+	fprintf(stderr,"%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__);
+	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__);
 	goto out;
+    }
+    snprintf(dom_id,  sizeof(dom_id), "dom-id=%s", xs_value);
 
-    fprintf(stderr, "%s", xs_value);
+    return 0;
 
  out:
-    return;
+    return -1;
+}
+
+static void usage(FILE *fp)
+{
+    fprintf(fp,
+	    "This little daemon publishes xen domain info via mDNS.\n"
+	    "\n"
+	    "usage: mdns-publish-xendom [options]\n"
+	    "options:\n"
+	    "   -h  print this text\n"
+	    "   -d  enable debug mode\n"
+	    "\n"
+	    "-- \n"
+	    "(c) 2006 Gerd Hoffmann <kraxel@suse.de>\n");
 }
 
 int main(int argc, char*argv[])
@@ -139,18 +175,36 @@ int main(int argc, char*argv[])
     AvahiClient *client = NULL;
     char buf[128];
     struct utsname uts;
-    int error;
+    int error,c;
     int ret = 1;
 
+    /* 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);
     snprintf(buf, sizeof(buf), "Xen domain %s", uts.nodename);
     name = avahi_strdup(buf);
 
     /* figure domain info */
-    xendom_info();
+    if (0 != xendom_info())
+	exit(1);
     
-    /* go announce info */
+    /* prepare nDNS bits */
     simple_poll = avahi_simple_poll_new();
     if (!simple_poll) {
         fprintf(stderr, "Failed to create simple poll object.\n");
@@ -164,6 +218,23 @@ int main(int argc, char*argv[])
         goto fail;
     }
 
+    /* damonize */
+    if (!debug) {
+	switch (fork()) {
+        case -1:
+            perror("fork");
+            exit(1);
+        case 0:
+            close(0); close(1); close(2);
+            setsid();
+            open("/dev/null", O_RDWR); dup(0); dup(0);
+            break;
+        default:
+            exit(0);
+        }
+   }
+
+    /* go ahead */
     avahi_simple_poll_loop(simple_poll);
     ret = 0;