Add a new setting to specify the interface the service should be provided on.

1 files changed, 31 insertions, 25 deletions

diff --git a/mdns_tinysvcmdns.c b/mdns_tinysvcmdns.c
index 8d51d4b..57f41ae 100644
--- a/mdns_tinysvcmdns.c
+++ b/mdns_tinysvcmdns.c
@@ -70,17 +70,21 @@ static int mdns_tinysvcmdns_register(char *apname, int port) {
 
   // Look for an ipv4/ipv6 non-loopback interface to use as the main one.
   for (ifa = ifalist; ifa != NULL; ifa = ifa->ifa_next) {
-    if (!(ifa->ifa_flags & IFF_LOOPBACK) && ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
-      uint32_t main_ip = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
-
-      mdnsd_set_hostname(svr, hostname, main_ip); // TTL should be 120 seconds
-      break;
-    } else if (!(ifa->ifa_flags & IFF_LOOPBACK) && ifa->ifa_addr &&
-               ifa->ifa_addr->sa_family == AF_INET6) {
-      struct in6_addr *addr = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
-
-      mdnsd_set_hostname_v6(svr, hostname, addr); // TTL should be 120 seconds
-      break;
+    // only check for the named interface, if specified
+    if ((config.interface==NULL) || (strcmp(config.interface,ifa->ifa_name)==0)) {
+ 
+      if (!(ifa->ifa_flags & IFF_LOOPBACK) && ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
+        uint32_t main_ip = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
+
+        mdnsd_set_hostname(svr, hostname, main_ip); // TTL should be 120 seconds
+        break;
+      } else if (!(ifa->ifa_flags & IFF_LOOPBACK) && ifa->ifa_addr &&
+                 ifa->ifa_addr->sa_family == AF_INET6) {
+        struct in6_addr *addr = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
+
+        mdnsd_set_hostname_v6(svr, hostname, addr); // TTL should be 120 seconds
+        break;
+      }
     }
   }
 
@@ -92,20 +96,22 @@ static int mdns_tinysvcmdns_register(char *apname, int port) {
   // Skip the first one, it was already added by set_hostname
   for (ifa = ifa->ifa_next; ifa != NULL; ifa = ifa->ifa_next) {
     if (ifa->ifa_flags & IFF_LOOPBACK) // Skip loop-back interfaces
-      continue;
-
-    switch (ifa->ifa_addr->sa_family) {
-    case AF_INET: { // ipv4
-      uint32_t ip = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
-      struct rr_entry *a_e = rr_create_a(create_nlabel(hostname), ip); // TTL should be 120 seconds
-      mdnsd_add_rr(svr, a_e);
-    } break;
-    case AF_INET6: { // ipv6
-      struct in6_addr *addr = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
-      struct rr_entry *aaaa_e =
-          rr_create_aaaa(create_nlabel(hostname), addr); // TTL should be 120 seconds
-      mdnsd_add_rr(svr, aaaa_e);
-    } break;
+      continue;    
+    // only check for the named interface, if specified
+    if ((config.interface==NULL) || (strcmp(config.interface,ifa->ifa_name)==0)) {
+      switch (ifa->ifa_addr->sa_family) {
+        case AF_INET: { // ipv4
+          uint32_t ip = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
+          struct rr_entry *a_e = rr_create_a(create_nlabel(hostname), ip); // TTL should be 120 seconds
+          mdnsd_add_rr(svr, a_e);
+        } break;
+        case AF_INET6: { // ipv6
+          struct in6_addr *addr = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
+          struct rr_entry *aaaa_e =
+              rr_create_aaaa(create_nlabel(hostname), addr); // TTL should be 120 seconds
+          mdnsd_add_rr(svr, aaaa_e);
+        } break;
+      }
     }
   }