From 044ab6e57a3bfb46da351224b77d800857673348 Mon Sep 17 00:00:00 2001
From: James Cowan <jamesmcowan@googlemail.com>
Date: Thu, 10 Nov 2016 17:49:33 +0000
Subject: [PATCH] add multicast

---
 ios/UdpSocketClient.h | 16 ++++++++++++++++
 ios/UdpSocketClient.m | 18 ++++++++++++++++++
 ios/UdpSockets.m      | 14 ++++++++++++--
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/ios/UdpSocketClient.h b/ios/UdpSocketClient.h
index 5e72a63..db92994 100644
--- a/ios/UdpSocketClient.h
+++ b/ios/UdpSocketClient.h
@@ -65,6 +65,22 @@ typedef enum RCTUDPError RCTUDPError;
  */
 - (BOOL)bind:(u_int16_t) port address:(NSString*) address error:(NSError**)error;
 
+/**
+ * Join multicast groupt
+ *
+ * @param address
+ * @return true if joined, false if there was an error
+ */
+- (BOOL)joinMulticastGroup:(NSString *)address error:(NSError **) error;
+
+/**
+ * leave multicast groupt
+ *
+ * @param address
+ * @return true if joined, false if there was an error
+ */
+- (BOOL)leaveMulticastGroup:(NSString *)address error:(NSError **) error;
+
 /**
  * send data to another host and port
  *
diff --git a/ios/UdpSocketClient.m b/ios/UdpSocketClient.m
index 956053a..c814ad8 100644
--- a/ios/UdpSocketClient.m
+++ b/ios/UdpSocketClient.m
@@ -110,6 +110,24 @@ NSString *const RCTUDPErrorDomain = @"RCTUDPErrorDomain";
   return result && [_udpSocket beginReceiving:error];
 }
 
+- (BOOL)joinMulticastGroup:(NSString *)address error:(NSError **) error
+{
+    if(![_udpSocket joinMulticastGroup:address error:&error]){
+        NSLog(@"Error joining multicast group: %@", error);
+        return false;
+    }
+    return true;
+}
+
+- (BOOL)leaveMulticastGroup:(NSString *)address error:(NSError **) error
+{
+    if(![_udpSocket leaveMulticastGroup:address error:&error]){
+        NSLog(@"Error leaving multicast group: %@", error);
+        return false;
+    }
+    return true;
+}
+
 - (void)udpSocket:(GCDAsyncUdpSocket *)sock didSendDataWithTag:(long)msgTag
 {
   NSNumber* tagNum = [NSNumber numberWithLong:msgTag];
diff --git a/ios/UdpSockets.m b/ios/UdpSockets.m
index 16559e8..6f0f8ad 100644
--- a/ios/UdpSockets.m
+++ b/ios/UdpSockets.m
@@ -106,12 +106,22 @@ RCT_EXPORT_METHOD(setBroadcast:(nonnull NSNumber*)cId
 
 RCT_EXPORT_METHOD(addMembership:(nonnull NSNumber*)cId
                   multicastAddress:(NSString *)address) {
-    /* nop */
+     UdpSocketClient *client = _clients[cId];
+    
+    if (!client) return;
+    
+    NSError *error = nil;
+    [client joinMulticastGroup:address error:&error];
 }
 
 RCT_EXPORT_METHOD(dropMembership:(nonnull NSNumber*)cId
                   multicastAddress:(NSString *)address) {
-    /* nop */
+    UdpSocketClient *client = _clients[cId];
+    
+    if (!client) return;
+    
+    NSError *error = nil;
+    [client leaveMulticastGroup:address error:&error];
 }
 
 - (void) onData:(UdpSocketClient*) client data:(NSData *)data host:(NSString *)host port:(uint16_t)port