# HG changeset patch
# User jbe
# Date 1609729775 -3600
# Node ID fb8f86d3703ed0c7cd26e7e72d09d347794b970b
# Parent  86121074cd91ffaa2692a5d089c75ad09fbcc225
Make moonbridge_io.tcplisten(nil, port) accept both IPv6 and IPv4 connections independently of operating system setting; if first argument is non-nil and resolves to an IPv6 address, never accept IPv4 connections

diff -r 86121074cd91 -r fb8f86d3703e moonbridge_io.c
--- a/moonbridge_io.c	Sun Dec 20 20:59:40 2020 +0100
+++ b/moonbridge_io.c	Mon Jan 04 04:09:35 2021 +0100
@@ -1345,6 +1345,17 @@
       return 2;
     }
   }
+  if (addrinfo->ai_family == AF_INET6) {
+    const int ipv6onlyval = (host != NULL) ? 1 : 0;
+    if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6onlyval, sizeof(ipv6onlyval))) {
+      moonbr_io_prepare_errmsg();
+      freeaddrinfo(res);
+      close(sock);
+      lua_pushnil(L);
+      lua_pushfstring(L, "Error while setting IPV6_V6ONLY with setsockopt: %s", errmsg);
+      return 2;
+    }
+  }
   if (bind(sock, addrinfo->ai_addr, addrinfo->ai_addrlen)) {
     moonbr_io_prepare_errmsg();
     freeaddrinfo(res);