--- src/libcharon/plugins/socket_default/socket_default_socket.c.orig	2020-09-14 00:44:03.000000000 +0700
+++ src/libcharon/plugins/socket_default/socket_default_socket.c	2022-10-06 03:54:04.472789000 +0700
@@ -430,6 +430,7 @@ static ssize_t send_msg_v4(private_socke
 	struct in_addr *addr;
 	struct sockaddr_in *sin;
 
+    if (getenv("STRONGSWAN_BIND") == NULL) {
 	msg->msg_control = buf;
 	msg->msg_controllen = sizeof(buf);
 	cmsg = CMSG_FIRSTHDR(msg);
@@ -441,6 +442,7 @@ static ssize_t send_msg_v4(private_socke
 
 	sin = (struct sockaddr_in*)src->get_sockaddr(src);
 	memcpy(addr, &sin->sin_addr, sizeof(struct in_addr));
+    }
 	return send_msg_generic(skt, msg);
 }
 
@@ -663,6 +665,7 @@ static int open_socket(private_socket_de
 	socklen_t addrlen;
 	u_int sol, pktinfo = 0;
 	int skt;
+	char *s;
 
 	memset(&addr, 0, sizeof(addr));
 	addr.sockaddr.sa_family = family;
@@ -670,7 +673,9 @@ static int open_socket(private_socket_de
 	switch (family)
 	{
 		case AF_INET:
-			addr.sin.sin_addr.s_addr = htonl(INADDR_ANY);
+			s = getenv("STRONGSWAN_BIND");
+			if (s == NULL || inet_pton(AF_INET, s, &addr.sin.sin_addr) == 0)
+				addr.sin.sin_addr.s_addr = htonl(INADDR_ANY);
 			addr.sin.sin_port = htons(*port);
 			addrlen = sizeof(addr.sin);
 			sol = SOL_IP;
--- src/libcharon/plugins/socket_dynamic/socket_dynamic_socket.c.orig	2020-09-14 00:44:03.000000000 +0700
+++ src/libcharon/plugins/socket_dynamic/socket_dynamic_socket.c	2022-10-06 03:55:05.904883000 +0700
@@ -379,12 +379,16 @@ static int open_socket(private_socket_dy
 	socklen_t addrlen;
 	u_int sol, pktinfo = 0;
 	int fd;
+	char *s;
 
 	memset(&addr, 0, sizeof(addr));
 	/* precalculate constants depending on address family */
 	switch (family)
 	{
 		case AF_INET:
+			s = getenv("STRONGSWAN_BIND");
+			if (s == NULL || inet_pton(AF_INET, s, &addr.sin.sin_addr) == 0)
+				addr.sin.sin_addr.s_addr = htonl(INADDR_ANY);
 			addr.sin.sin_family = AF_INET;
 			addr.sin.sin_addr.s_addr = INADDR_ANY;
 			addr.sin.sin_port = htons(*port);
@@ -543,6 +547,7 @@ static ssize_t send_msg_v4(int skt, stru
 	struct in_pktinfo *pktinfo;
 	struct sockaddr_in *sin;
 
+    if (getenv("STRONGSWAN_BIND") == NULL) {
 	msg->msg_control = buf;
 	msg->msg_controllen = sizeof(buf);
 	cmsg = CMSG_FIRSTHDR(msg);
@@ -555,6 +560,7 @@ static ssize_t send_msg_v4(int skt, stru
 
 	sin = (struct sockaddr_in*)src->get_sockaddr(src);
 	memcpy(addr, &sin->sin_addr, sizeof(struct in_addr));
+    }
 	return send_msg_generic(skt, msg);
 }