From 78cc9b4b03bdd4f95c277391cac6e0951407072b Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Fri, 6 Feb 2026 23:20:39 -0600
Subject: [PATCH] Only pass the peer's local address if the host was wildcard
 bound

---
 host.c              |  2 ++
 include/enet/enet.h |  2 ++
 protocol.c          |  4 +++-
 unix.c              | 24 ++++++++++++++++++++++++
 win32.c             | 22 ++++++++++++++++++++++
 5 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/host.c b/host.c
index 1cf0c05..7668a4e 100644
--- a/host.c
+++ b/host.c
@@ -61,6 +61,8 @@ enet_host_create (int addressFamily, const ENetAddress * address, size_t peerCou
        return NULL;
     }
 
+    host -> wildcardBind = address && enet_address_wildcard (address);
+
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_NONBLOCK, 1);
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_RCVBUF, ENET_HOST_RECEIVE_BUFFER_SIZE);
     enet_socket_set_option (host -> socket, ENET_SOCKOPT_SNDBUF, ENET_HOST_SEND_BUFFER_SIZE);
diff --git a/include/enet/enet.h b/include/enet/enet.h
index 791e303..985b883 100644
--- a/include/enet/enet.h
+++ b/include/enet/enet.h
@@ -364,6 +364,7 @@ typedef int (ENET_CALLBACK * ENetInterceptCallback) (struct _ENetHost * host, st
 typedef struct _ENetHost
 {
    ENetSocket           socket;
+   int                  wildcardBind;
    ENetAddress          address;                     /**< Internet address of the host */
    enet_uint32          incomingBandwidth;           /**< downstream bandwidth of the host */
    enet_uint32          outgoingBandwidth;           /**< upstream bandwidth of the host */
@@ -527,6 +528,7 @@ ENET_API int        enet_socketset_select (ENetSocket, ENetSocketSet *, ENetSock
 ENET_API int enet_address_set_host (ENetAddress * address, const char * hostName);
 ENET_API int enet_address_set_address (ENetAddress * address, struct sockaddr * addr, socklen_t addrlen);
 ENET_API int enet_address_set_port (ENetAddress * address, enet_uint16 port);
+ENET_API int enet_address_wildcard (const ENetAddress * address);
 ENET_API int enet_address_equal (ENetAddress * address1, ENetAddress * address2);
 
 /** @} */
diff --git a/protocol.c b/protocol.c
index f5301fc..1fa4de0 100644
--- a/protocol.c
+++ b/protocol.c
@@ -1731,7 +1731,9 @@ enet_protocol_send_outgoing_commands (ENetHost * host, ENetEvent * event, int ch
             enet_socket_set_option (host -> socket, ENET_SOCKOPT_QOS, 0);
         }
 
-        sentLength = enet_socket_send (host -> socket, & currentPeer -> address, & currentPeer -> localAddress, host -> buffers, host -> bufferCount);
+        sentLength = enet_socket_send (host -> socket, & currentPeer -> address,
+                                       host -> wildcardBind ? (& currentPeer -> localAddress) : NULL,
+                                       host -> buffers, host -> bufferCount);
 
         enet_protocol_remove_sent_unreliable_commands (currentPeer, & sentUnreliableCommands);
 
diff --git a/unix.c b/unix.c
index f5563c0..251e144 100644
--- a/unix.c
+++ b/unix.c
@@ -269,6 +269,30 @@ enet_address_equal (ENetAddress * address1, ENetAddress * address2)
     }
 }
 
+int
+enet_address_wildcard (const ENetAddress * address)
+{
+    switch (address -> address.ss_family)
+    {
+    case AF_INET:
+    {
+        struct sockaddr_in *sin = (struct sockaddr_in *) & address -> address;
+        return sin -> sin_addr.s_addr == INADDR_ANY;
+    }
+#ifdef AF_INET6
+    case AF_INET6:
+    {
+        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) & address -> address;
+        return ! memcmp (& sin6 -> sin6_addr, & in6addr_any, sizeof (in6addr_any));
+    }
+#endif
+    default:
+    {
+        return 0;
+    }
+    }
+}
+
 int
 enet_address_set_port (ENetAddress * address, enet_uint16 port)
 {
diff --git a/win32.c b/win32.c
index b1b707c..a93594b 100644
--- a/win32.c
+++ b/win32.c
@@ -190,6 +190,28 @@ enet_address_equal (ENetAddress * address1, ENetAddress * address2)
     }
 }
 
+int
+enet_address_wildcard (const ENetAddress * address)
+{
+    switch (address -> address.ss_family)
+    {
+    case AF_INET:
+    {
+        struct sockaddr_in *sin = (struct sockaddr_in *) & address -> address;
+        return sin -> sin_addr.S_un.S_addr == INADDR_ANY;
+    }
+    case AF_INET6:
+    {
+        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) & address -> address;
+        return ! memcmp (& sin6 -> sin6_addr, & in6addr_any, sizeof (in6addr_any));
+    }
+    default:
+    {
+        return 0;
+    }
+    }
+}
+
 int
 enet_address_set_host (ENetAddress * address, const char * name)
 {