From: Wouter Wijngaards <wouter@nlnetlabs.nl>
Date: Fri, 6 Jul 2018 14:40:35 +0000 (+0000)
Subject: - Fix round robin for failed addresses with prefer-ip6: yes
X-Git-Tag: release-1.8.0rc1~106
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5e3c30beac726e0a7d712864929ac325e1f44ff4;p=thirdparty%2Funbound.git

- Fix round robin for failed addresses with prefer-ip6: yes


git-svn-id: file:///svn/unbound/trunk@4776 be551aaa-1e26-0410-a405-d3ace91eadb9
---

diff --git a/doc/Changelog b/doc/Changelog
index 52ede2978..c4c1e1864 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -4,6 +4,7 @@
 	- iana port update.
 	- Note RFC8162 support.  SMIMEA record type can be read in by the
 	  zone record parser.
+	- Fix round robin for failed addresses with prefer-ip6: yes
 
 4 July 2018: Wouter
 	- Fix #4112: Fix that unbound-anchor -f /etc/resolv.conf will not pass
diff --git a/iterator/iter_utils.c b/iterator/iter_utils.c
index df66776ae..90c8cf114 100644
--- a/iterator/iter_utils.c
+++ b/iterator/iter_utils.c
@@ -378,17 +378,32 @@ iter_filter_order(struct iter_env* iter_env, struct module_env* env,
 		int attempt = -1; /* filter to make sure addresses have
 		  less attempts on them than the first, to force round
 		  robin when all the IPv6 addresses fail */
+		int num4ok = 0; /* number ip4 at low attempt count */
+		int num4_lowrtt = 0;
 		prev = NULL;
 		a = dp->result_list;
 		for(i = 0; i < got_num; i++) {
 			swap_to_front = 0;
-			if(a->addr.ss_family != AF_INET6 && attempt == -1)
+			if(a->addr.ss_family != AF_INET6 && attempt == -1) {
+				/* if we only have ip4 at low attempt count,
+				 * then ip6 is failing, and we need to
+				 * select one of the remaining IPv4 addrs */
 				attempt = a->attempts;
-			if(a->addr.ss_family == AF_INET6 &&
-				(attempt==-1 || a->attempts<=attempt)) {
-				got_num6++;
-				if(attempt == -1)
+				num4ok++;
+				num4_lowrtt = a->sel_rtt;
+			} else if(a->addr.ss_family != AF_INET6 && attempt == a->attempts) {
+				num4ok++;
+				if(num4_lowrtt == 0 || a->sel_rtt < num4_lowrtt) {
+					num4_lowrtt = a->sel_rtt;
+				}
+			}
+			if(a->addr.ss_family == AF_INET6) {
+				if(attempt == -1) {
 					attempt = a->attempts;
+				} else if(a->attempts > attempt) {
+					break;
+				}
+				got_num6++;
 				swap_to_front = 1;
 				if(low_rtt6 == 0 || a->sel_rtt < low_rtt6) {
 					low_rtt6 = a->sel_rtt;
@@ -409,6 +424,9 @@ iter_filter_order(struct iter_env* iter_env, struct module_env* env,
 		if(got_num6 > 0) {
 			got_num = got_num6;
 			*selected_rtt = low_rtt6;
+		} else if(num4ok > 0) {
+			got_num = num4ok;
+			*selected_rtt = num4_lowrtt;
 		}
 	}
 	return got_num;