Index: dnsrbl.c
diff -u -p dnsrbl.c.orig dnsrbl.c
--- dnsrbl.c.orig	2013-01-20 01:01:15.000000000 +0900
+++ dnsrbl.c	2015-12-24 11:17:32.566399930 +0900
@@ -113,7 +113,6 @@ dnsrbl_check_source(ad, stage, ap, priv)
 #ifdef HAVE_RES_NINIT
 	struct __res_state res;
 #endif
-	sockaddr_t ss;
 	char req[NS_MAXDNAME + 1];
 	unsigned char *ans = NULL;
 	int anslen;
@@ -138,9 +137,15 @@ dnsrbl_check_source(ad, stage, ap, priv)
 	if (dnsrbl_matched(priv, source))
 		return 1;
 
-	/* No IPv6 DNSRBL exists right now */
-	if (sa->sa_family != AF_INET)
+	switch (sa->sa_family) {
+	case AF_INET:
+#ifdef AF_INET6
+	case AF_INET6:
+#endif
+		break;
+	default:
 		return 0;
+	}
 
 	blacklisted = SA(&source->d_blacklisted);
 
@@ -172,10 +177,8 @@ dnsrbl_check_source(ad, stage, ap, priv)
 		return 0;
 	}
 
-	reverse_endian(SA(&ss), sa);
-
-	if ((iptostring(SA(&ss), salen, req, NS_MAXDNAME)) == NULL){
-		mg_log(LOG_ERR, "iptostring failed: %s", strerror(errno));
+	if ((iptorevstr(sa, salen, req, NS_MAXDNAME)) == NULL){
+		mg_log(LOG_ERR, "iptorevstr failed: %s", strerror(errno));
 		goto end;
 	}
 
@@ -276,45 +279,41 @@ end:
 	return retval;
 }
 
-
-/* XXX this code is probably broken with IPv6 */
-void
-reverse_endian(dst, src)
-	struct sockaddr *src;
-	struct sockaddr *dst;
+char *
+iptorevstr(sa, salen, buf, buflen)
+	struct sockaddr *sa;
+	socklen_t salen;
+	char *buf;
+	size_t buflen;
 {
-	int i, len;
-	char *src_start;
-	char *dst_start;
+	struct in_addr abuf;
+	char *addr;
+	int i;
 
-	switch (src->sa_family) {
+	switch (sa->sa_family) {
 	case AF_INET:
-		src_start = (char *)SADDR4(src);
-		dst_start = (char *)SADDR4(dst);
-		len = sizeof(*SADDR4(src));
+		addr = (char *)SADDR4(sa);
+		for (i = 0; i < sizeof(abuf); ++i)
+			((char *)&abuf)[sizeof(abuf) - 1 - i] = addr[i];
+		if (inet_ntop(sa->sa_family, &abuf, buf, buflen) != NULL)
+			return buf;
 		break;
 #ifdef AF_INET6
 	case AF_INET6:
-		src_start = (char *)SADDR6(src);
-		dst_start = (char *)SADDR6(dst);
-		len = sizeof(*SADDR6(src));
-		break;
+		if (buflen < sizeof(struct in6_addr) * 4)
+			break;
+		addr = (char *)SADDR6(sa);
+		i = sizeof(struct in6_addr) - 1;
+		sprintf(buf, "%x.%x", addr[i] & 0x0f, (addr[i] & 0xf0) >> 4);
+		for (--i; i >= 0; --i)
+			sprintf(buf + (sizeof(struct in6_addr) - i) * 4 - 5,
+			    ".%x.%x", addr[i] & 0x0f, (addr[i] & 0xf0) >> 4);
+		return buf;
 #endif
 	default:
-		mg_log(LOG_ERR, "invalid address family %d", src->sa_family);
-		exit(EX_SOFTWARE);
-		break;
+		return NULL;
 	}
-
-	dst->sa_family = src->sa_family;
-#ifdef HAVE_SA_LEN
-	dst->sa_len = src->sa_len;
-#endif
-
-	for (i = 0; i < len; i++)
-		dst_start[len - 1 - i] = src_start[i];
-
-	return;
+	return NULL;
 }
 
 void	/* acllist must be write locked */
Index: dnsrbl.h
diff -u dnsrbl.h.orig dnsrbl.h
--- dnsrbl.h.orig	2007-11-07 09:02:27.000000000 +0900
+++ dnsrbl.h	2015-12-24 11:18:01.304930037 +0900
@@ -54,7 +54,7 @@
 void dnsrbl_init(void);
 int dnsrbl_check_source(acl_data_t *, acl_stage_t,
 			struct acl_param *, struct mlfi_priv *);
-void reverse_endian(struct sockaddr *, struct sockaddr *);
+char *iptorevstr(struct sockaddr *, socklen_t, char *, size_t);
 void dnsrbl_source_add(char *, char *, struct sockaddr *, int);
 struct dnsrbl_entry *dnsrbl_byname(char *);
 void dnsrbl_clear(void);