From e401f4fcb9bf48e4efd04f9671a7c6cf44ff0439 Mon Sep 17 00:00:00 2001
From: Niklas Hofmann <niklas.hofmann@everbase.net>
Date: Thu, 31 Jul 2014 03:08:06 +0200
Subject: [PATCH] a first mdns discovery implementation

---
 src/discovery.c | 36 ++++++++++++++++++++++++++++++++++--
 src/meshlink.c  |  2 +-
 src/meshlink.h  |  2 +-
 src/node.c      |  2 +-
 src/node.h      |  2 +-
 5 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/src/discovery.c b/src/discovery.c
index 834822aa..a7b36c48 100644
--- a/src/discovery.c
+++ b/src/discovery.c
@@ -12,6 +12,8 @@
 #include <avahi-common/alternative.h>
 #include <avahi-common/error.h>
 
+#include <netinet/in.h>
+
 #define MESHLINK_MDNS_SERVICE_TYPE "_meshlink._tcp"
 //#define MESHLINK_MDNS_SERVICE_NAME "Meshlink"
 #define MESHLINK_MDNS_FINGERPRINT_KEY "fingerprint"
@@ -76,10 +78,40 @@ static void discovery_resolve_callback(
             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);
+
+                struct sockaddr_storage naddr;
+                memset(&naddr, 0, sizeof(naddr));
+
+                switch(address->proto)
+                {
+                    case AVAHI_PROTO_INET:
+                    {
+                        struct sockaddr_in* naddr_in = (struct sockaddr_in*)&naddr;
+                        naddr_in->sin_family = AF_INET;
+                        naddr_in->sin_port = port;
+                        naddr_in->sin_addr.s_addr = address->data.ipv4.address;
+                    }
+                    break;
+
+                    case AVAHI_PROTO_INET6:
+                    {
+                        struct sockaddr_in6* naddr_in = (struct sockaddr_in6*)&naddr;
+                        naddr_in->sin6_family = AF_INET6;
+                        naddr_in->sin6_port = port;
+                        memcpy(naddr_in->sin6_addr.s6_addr, address->data.ipv6.address, sizeof(naddr_in->sin6_addr.s6_addr));
+                    }
+                    break;
+
+                    default:
+                    naddr.ss_family = AF_UNKNOWN;
+                }
+
+                // @TODO: aquire mutex?
+                meshlink_hint_address(mesh, node->name, &naddr);
             }
             else
             {
-                fprintf(stderr, "Node %s is not part of the mesh network - ignoring ip address.\n", node->name);
+                fprintf(stderr, "Node %s is not part of the mesh network - ignoring ip address.\n", node ? node->name : "n/a");
             }
         }
     }
@@ -298,7 +330,7 @@ fail:
 
 void discovery_stop(meshlink_handle_t *mesh)
 {
-	// @TODO: Shut down 
+	// Shut down 
 	avahi_simple_poll_quit(mesh->avahi_poll);
 
 	// Wait for the discovery thread to finish
diff --git a/src/meshlink.c b/src/meshlink.c
index 8d120813..c25e08c5 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1660,7 +1660,7 @@ void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 /* Hint that a hostname may be found at an address
  * See header file for detailed comment.
  */
-extern void meshlink_hint_address(meshlink_handle_t *mesh, char *hostname, struct sockaddr *addr) {
+extern void meshlink_hint_address(meshlink_handle_t *mesh, const char *hostname, struct sockaddr *addr) {
 	if(!mesh || !hostname || !addr)
 		return;
 	
diff --git a/src/meshlink.h b/src/meshlink.h
index 8a101741..4468fd00 100644
--- a/src/meshlink.h
+++ b/src/meshlink.h
@@ -574,7 +574,7 @@ extern ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t
  *  			given hostname. The caller is free to overwrite or free
  *  			this memory once meshlink returns.
  */
-extern void meshlink_hint_address(meshlink_handle_t *mesh, char *hostname, struct sockaddr *addr);
+extern void meshlink_hint_address(meshlink_handle_t *mesh, const char *hostname, struct sockaddr *addr);
 
 #ifdef __cplusplus
 }
diff --git a/src/node.c b/src/node.c
index b7b39927..edf2c858 100644
--- a/src/node.c
+++ b/src/node.c
@@ -104,7 +104,7 @@ void node_del(meshlink_handle_t *mesh, node_t *n) {
 	pthread_mutex_unlock(&(mesh->nodes_mutex));
 }
 
-node_t *lookup_node(meshlink_handle_t *mesh, char *name) {
+node_t *lookup_node(meshlink_handle_t *mesh, const char *name) {
 	node_t n = {NULL};
 	node_t* result;
 
diff --git a/src/node.h b/src/node.h
index 4f0f1308..e9bc0538 100644
--- a/src/node.h
+++ b/src/node.h
@@ -97,7 +97,7 @@ extern node_t *new_node(void) __attribute__ ((__malloc__));
 extern void free_node(node_t *);
 extern void node_add(struct meshlink_handle *mesh, node_t *);
 extern void node_del(struct meshlink_handle *mesh, node_t *);
-extern node_t *lookup_node(struct meshlink_handle *mesh, char *);
+extern node_t *lookup_node(struct meshlink_handle *mesh, const char *);
 extern node_t *lookup_node_udp(struct meshlink_handle *mesh, const sockaddr_t *);
 extern void update_node_udp(struct meshlink_handle *mesh, node_t *, const sockaddr_t *);
 
-- 
2.39.2