From f18a751f8956fb4f1696a4ec426846ff0d859852 Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Fri, 17 Jul 2026 15:07:11 +0300
Subject: [PATCH] define IPV6_BOUND_IF if not defined (for legacy MacOS
 10.x)

See: https://github.com/3proxy/3proxy/issues/1250
Upstream-Status: Backport [https://github.com/3proxy/3proxy/compare/f18a751f89%5E...afb2ec0696]
---
 src/common.c    | 3 +++
 src/proxymain.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/src/common.c b/src/common.c
index 3444dcd..f0eada7 100644
--- src/common.c.orig
+++ src/common.c
@@ -659,7 +659,9 @@ int doconnect(struct clientparam * param){
 	    if(!idx || (*SAFAMILY(&param->sinsl) == AF_INET && param->srv->so._setsockopt(param->sostate, param->remsock, IPPROTO_IP, IP_BOUND_IF, &idx, sizeof(idx))))
 			return 12;
 #ifndef NOIPV6
+#ifdef IPV6_BOUND_IF
 	    if(*SAFAMILY(&param->sinsl) == AF_INET6 && param->srv->so._setsockopt(param->sostate, param->remsock, IPPROTO_IPV6, IPV6_BOUND_IF, &idx, sizeof(idx))) return 12;
+#endif
 #endif
 	}
 #endif

diff --git a/src/proxymain.c b/src/proxymain.c
index fe938f8..08eef95 100644
--- src/proxymain.c.orig
+++ src/proxymain.c
@@ -772,10 +772,12 @@ int MODULEMAINFUNC (int argc, char** argv){
 			return -12;
 		    }
 #ifndef NOIPV6
+#ifdef IPV6_BOUND_IF
 	            if((*SAFAMILY(&srv.intsa) == AF_INET6 && srv.so._setsockopt(srv.so.state, sock, IPPROTO_IPV6, IPV6_BOUND_IF, &idx, sizeof(idx)))) {
 			dolog(&defparam, (unsigned char *)"failed to bind device");
 	        	return -12;
 	    	    }
+#endif
 #endif
 		}
 #endif
--
2.55.0