avahi mdns integration

diff --git a/src/discovery.c b/src/discovery.c
index a57cfb838fdeba5951921ad2c29ae60681232f3d..834822aa341537bc26c33bac6991ca9ebf0e0031 100644 (file)
--- a/src/discovery.c
+++ b/src/discovery.c
@@ -13,8 +13,79 @@
 #include <avahi-common/error.h>
 
 #define MESHLINK_MDNS_SERVICE_TYPE "_meshlink._tcp"
-#define MESHLINK_MDNS_SERVICE_NAME "Meshlink"
+//#define MESHLINK_MDNS_SERVICE_NAME "Meshlink"
+#define MESHLINK_MDNS_FINGERPRINT_KEY "fingerprint"
+
+static void discovery_resolve_callback(
+    AvahiSServiceResolver *resolver,
+    AVAHI_GCC_UNUSED AvahiIfIndex interface,
+    AVAHI_GCC_UNUSED AvahiProtocol protocol,
+    AvahiResolverEvent event,
+    const char *name,
+    const char *type,
+    const char *domain,
+    const char *host_name,
+    const AvahiAddress *address,
+    uint16_t port,
+    AvahiStringList *txt,
+    AvahiLookupResultFlags flags,
+    AVAHI_GCC_UNUSED void* userdata)
+{
 
+    meshlink_handle_t *mesh = userdata;
+
+    /* Called whenever a service has been resolved successfully or timed out */
+
+    switch (event)
+    {
+        case AVAHI_RESOLVER_FAILURE:
+            fprintf(stderr, "(Resolver) Failed to resolve service '%s' of type '%s' in domain '%s': %s\n", name, type, domain, avahi_strerror(avahi_server_errno(mesh->avahi_server)));
+            break;
+
+        case AVAHI_RESOLVER_FOUND:
+        {
+            char straddr[AVAHI_ADDRESS_STR_MAX], *strtxt;
+
+            fprintf(stderr, "(Resolver) Service '%s' of type '%s' in domain '%s':\n", name, type, domain);
+
+            avahi_address_snprint(straddr, sizeof(straddr), address);
+            strtxt = avahi_string_list_to_string(txt);
+            fprintf(stderr,
+                    "\t%s:%u (%s)\n"
+                    "\tTXT=%s\n"
+                    "\tcookie is %u\n"
+                    "\tis_local: %i\n"
+                    "\twide_area: %i\n"
+                    "\tmulticast: %i\n"
+                    "\tcached: %i\n",
+                    host_name, port, straddr,
+                    strtxt,
+                    avahi_string_list_get_service_cookie(txt),
+                    !!(flags & AVAHI_LOOKUP_RESULT_LOCAL),
+                    !!(flags & AVAHI_LOOKUP_RESULT_WIDE_AREA),
+                    !!(flags & AVAHI_LOOKUP_RESULT_MULTICAST),
+                    !!(flags & AVAHI_LOOKUP_RESULT_CACHED));
+            avahi_free(strtxt);
+
+            // retrieve fingerprint
+            AvahiStringList *fgli = avahi_string_list_find(txt, MESHLINK_MDNS_FINGERPRINT_KEY);
+            meshlink_node_t *node = meshlink_get_node(mesh, name);
+
+            fprintf(stderr, "%p, %p, %s, %s\n", fgli, node, avahi_string_list_get_text(fgli), meshlink_get_fingerprint(mesh, node));
+
+            if( node && fgli && strcmp(avahi_string_list_get_text(fgli)+strlen(MESHLINK_MDNS_FINGERPRINT_KEY)+1, meshlink_get_fingerprint(mesh, node)) == 0 )
+            {
+                fprintf(stderr, "Node %s is part of the mesh network - updating ip address.\n", node->name);
+            }
+            else
+            {
+                fprintf(stderr, "Node %s is not part of the mesh network - ignoring ip address.\n", node->name);
+            }
+        }
+    }
+
+    avahi_s_service_resolver_free(resolver);
+}
 
 static void discovery_entry_group_callback(AvahiServer *server, AvahiSEntryGroup *group, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata)
 {
@@ -25,11 +96,11 @@ static void discovery_entry_group_callback(AvahiServer *server, AvahiSEntryGroup
     {
         case AVAHI_ENTRY_GROUP_ESTABLISHED:
             /* The entry group has been established successfully */
-            fprintf(stderr, "Service '%s' successfully established.\n", MESHLINK_MDNS_SERVICE_NAME);
+            fprintf(stderr, "Service '%s' successfully established.\n", /*MESHLINK_MDNS_SERVICE_NAME*/ mesh->name);
             break;
 
         case AVAHI_ENTRY_GROUP_COLLISION:
-            fprintf(stderr, "Service name collision '%s'\n", MESHLINK_MDNS_SERVICE_NAME);
+            fprintf(stderr, "Service name collision '%s'\n", /*MESHLINK_MDNS_SERVICE_NAME*/ mesh->name);
             break;
 
         case AVAHI_ENTRY_GROUP_FAILURE :
@@ -48,22 +119,22 @@ static void discovery_entry_group_callback(AvahiServer *server, AvahiSEntryGroup
 
 static void discovery_create_services(meshlink_handle_t *mesh)
 {
+    fprintf(stderr, "Adding service '%s'\n", /*MESHLINK_MDNS_SERVICE_NAME*/ mesh->name);
+
     /* If this is the first time we're called, let's create a new entry group */
     if (!mesh->avahi_group)
-        if (!(mesh->avahi_group = avahi_s_entry_group_new(mesh->avahi_server, discovery_entry_group_callback, NULL))) {
+        if (!(mesh->avahi_group = avahi_s_entry_group_new(mesh->avahi_server, discovery_entry_group_callback, mesh))) {
             fprintf(stderr, "avahi_entry_group_new() failed: %s\n", avahi_strerror(avahi_server_errno(mesh->avahi_server)));
             goto fail;
         }
 
-    fprintf(stderr, "Adding service '%s'\n", MESHLINK_MDNS_SERVICE_NAME);
-
     /* Create some random TXT data */
-    char fingerprint[1024];
-    snprintf(fingerprint, sizeof(fingerprint), "fingerprint=%s", /*meshlink_get_fingerprint(mesh, mesh->self)*/ "");
+    char fingerprint[1024] = "";
+    snprintf(fingerprint, sizeof(fingerprint), "%s=%s", MESHLINK_MDNS_FINGERPRINT_KEY, meshlink_get_fingerprint(mesh, meshlink_get_node(mesh, mesh->name)));
 
     /* Add the service for IPP */
     int ret = 0;
-    if ((ret = avahi_server_add_service(mesh->avahi_server, mesh->avahi_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, MESHLINK_MDNS_SERVICE_NAME, MESHLINK_MDNS_SERVICE_TYPE, NULL, NULL, mesh->myport ? atoi(mesh->myport) : 655, fingerprint, NULL)) < 0) {
+    if ((ret = avahi_server_add_service(mesh->avahi_server, mesh->avahi_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, /*MESHLINK_MDNS_SERVICE_NAME*/ mesh->name, MESHLINK_MDNS_SERVICE_TYPE, NULL, NULL, mesh->myport ? atoi(mesh->myport) : 655, fingerprint, NULL)) < 0) {
         fprintf(stderr, "Failed to add _ipp._tcp service: %s\n", avahi_strerror(ret));
         goto fail;
     }
@@ -144,8 +215,8 @@ static void discovery_browse_callback(
                function we free it. If the server is terminated before
                the callback function is called the server will free
                the resolver for us. */
-            //if (!(avahi_s_service_resolver_new(s, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolve_callback, server)))
-            //    fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(server)));
+            if (!(avahi_s_service_resolver_new(mesh->avahi_server, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, discovery_resolve_callback, mesh)))
+                fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_server_errno(mesh->avahi_server)));
             break;
 
         case AVAHI_BROWSER_REMOVE:
@@ -184,7 +255,7 @@ bool discovery_start(meshlink_handle_t *mesh)
 
     /* Allocate a new server */
     int error;
-    mesh->avahi_server = avahi_server_new(avahi_simple_poll_get(mesh->avahi_poll), &config, discovery_server_callback, NULL, &error);
+    mesh->avahi_server = avahi_server_new(avahi_simple_poll_get(mesh->avahi_poll), &config, discovery_server_callback, mesh, &error);
 
     /* Free the configuration data */
     avahi_server_config_free(&config);