Patch-Source: https://src.fedoraproject.org/rpms/dnsmasq/blob/f36/f/0007-Retry-dhcp6-ping-on-interrupts.patch (backport from upstream)
--
From 467b621fb7da6e1318ac7204325b0adb01b3ff19 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
Date: Fri, 3 Sep 2021 16:48:50 +0200
Subject: [PATCH 07/15] Retry dhcp6 ping on interrupts

diff --git a/src/dhcp6.c b/src/dhcp6.c
index 2be877f..ae1f5c1 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -292,7 +292,7 @@ void get_client_mac(struct in6_addr *client, int iface, unsigned char *mac, unsi
       if ((maclen = find_mac(&addr, mac, 0, now)) != 0)
 	break;
 	  
-      sendto(daemon->icmp6fd, &neigh, sizeof(neigh), 0, &addr.sa, sizeof(addr));
+      while(retry_send(sendto(daemon->icmp6fd, &neigh, sizeof(neigh), 0, &addr.sa, sizeof(addr))));
       
       ts.tv_sec = 0;
       ts.tv_nsec = 100000000; /* 100ms */
-- 
2.31.1