From c71c95cd2babc5df397798d01be13519e00535dd Mon Sep 17 00:00:00 2001
From: WebSTUMP <webstump@chiark.greenend.org.uk>
Date: Mon, 8 Apr 2024 10:42:43 +0100
Subject: [PATCH] choose only one at random

---
 probes/modrelays-probe | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/probes/modrelays-probe b/probes/modrelays-probe
index 28db476..7c6884c 100755
--- a/probes/modrelays-probe
+++ b/probes/modrelays-probe
@@ -67,6 +67,11 @@ record-success () { record-outcome "$1" ok ''; }
 record-tempfail () { record-outcome "$1" tempfail "$2"; }
 record-permfail () { record-outcome "$1" permfail "$2"; }
 
+choose () {
+	local all=$1
+	shuf -n1 -o $all.chosen $all
+}
+
 probe-addr () {
 	local mx=$1
 	local addr=$2
@@ -136,11 +141,14 @@ probe-domain () {
 	case $rc in
 	0)
 		# have a list of MX's
-		exec 3<$td/dns
+		choose $td/dns
+
 		local pref
 		local mx
 		local statustype
 		local rhs
+
+		exec 3<$td/dns.chosen
 		while read <&3 pref mx statustype statustypenum rhs; do
 			case $statustypenum in
 			0)
@@ -156,10 +164,16 @@ probe-domain () {
 				rhs=${rhs##* (}
 				rhs=${rhs% )}
 				local addr
+				exec 5>$td/dns-addrs
 				for addr in $rhs; do
 					case $addr in
 					INET|INET6) continue ;;
 					esac
+					echo >&5 $addr
+				done
+				choose $td/dns-addrs
+				exec 5<$td/dns-addrs.chosen
+				while read addr <&5; do
 					probe-addr $mx $addr
 				done
 				;;
@@ -190,7 +204,8 @@ probe-domain () {
 	case $rc in
 	0)
 		# have a list of A's (dealt with MXs above)
-		exec 3<$td/dns
+		choose $td/dns
+		exec 3<$td/dns.chosen
 		local addr
 		while read <&3 addr; do
 			probe-addr 'NONE' $addr
-- 
2.30.2