From: Witold Kręcicki <wpk@isc.org>
Date: Mon, 13 Jan 2020 19:22:23 +0000 (+0100)
Subject: Disable pktinfo for ipv6 on all unices
X-Git-Tag: v9.15.8~14^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=20c077afc58386354630fa983d43eb90b7f890f9;p=thirdparty%2Fbind9.git

Disable pktinfo for ipv6 on all unices

If pktinfo were supported then we could listen on :: for ipv6 and get
the information about the destination address from pktinfo structure passed
in recvmsg but this method is not portable and libuv doesn't support it - so
we need to listen on all interfaces.
We should verify that this doesn't impact performance (we already do it for
ipv4) and either remove all the ipv6pktinfo detection code or think of fixing
libuv.
---

diff --git a/lib/isc/unix/net.c b/lib/isc/unix/net.c
index c2573bd381b..8613b827dab 100644
--- a/lib/isc/unix/net.c
+++ b/lib/isc/unix/net.c
@@ -90,7 +90,9 @@
 #endif /* HAVE_SYSCTLBYNAME */
 
 static isc_once_t 	once_ipv6only = ISC_ONCE_INIT;
+#ifdef __notyet__
 static isc_once_t 	once_ipv6pktinfo = ISC_ONCE_INIT;
+#endif
 
 #ifndef ISC_CMSG_IP_TOS
 #ifdef __APPLE__
@@ -284,6 +286,7 @@ initialize_ipv6only(void) {
 				  try_ipv6only) == ISC_R_SUCCESS);
 }
 
+#ifdef __notyet__
 static void
 try_ipv6pktinfo(void) {
 	int s, on;
@@ -331,6 +334,7 @@ initialize_ipv6pktinfo(void) {
 	RUNTIME_CHECK(isc_once_do(&once_ipv6pktinfo,
 				  try_ipv6pktinfo) == ISC_R_SUCCESS);
 }
+#endif
 
 isc_result_t
 isc_net_probe_ipv6only(void) {
@@ -340,7 +344,18 @@ isc_net_probe_ipv6only(void) {
 
 isc_result_t
 isc_net_probe_ipv6pktinfo(void) {
+/*
+ * XXXWPK if pktinfo were supported then we could listen on :: for ipv6 and get
+ * the information about the destination address from pktinfo structure passed
+ * in recvmsg but this method is not portable and libuv doesn't support it - so
+ * we need to listen on all interfaces.
+ * We should verify that this doesn't impact performance (we already do it for
+ * ipv4) and either remove all the ipv6pktinfo detection code from above
+ * or think of fixing libuv.
+ */
+#ifdef __notyet__
 	initialize_ipv6pktinfo();
+#endif
 	return (ipv6pktinfo_result);
 }