From: mutantmonkey <mutantmonkey@mutantmonkey.in>
Date: Sun, 21 Apr 2013 19:56:59 +0000 (-0400)
Subject: Fix segfault with mixed IPv4/IPv6 nameservers
X-Git-Tag: v0.85~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F5%2Fhead;p=thirdparty%2Fmtr.git

Fix segfault with mixed IPv4/IPv6 nameservers

Fixes bug #1154432
---

diff --git a/dns.c b/dns.c
index 683a4aa..8ea48ba 100644
--- a/dns.c
+++ b/dns.c
@@ -934,6 +934,8 @@ void dorequest(char *s,int type,word id)
   hp->id = id;	/* htons() deliberately left out (redundant) */
 #ifdef ENABLE_IPV6
   for (i = 0;i < NSCOUNT6;i++) {
+    if (!NSSOCKADDR6(i))
+      continue;
     if (NSSOCKADDR6(i)->sin6_family == AF_INET6)
       (void)sendto(resfd6,buf,r,0,(struct sockaddr *) NSSOCKADDR6(i),
 		   sizeof(struct sockaddr_in6));
@@ -1340,6 +1342,8 @@ void dns_ack6(void)
       }
     } else
       for (i = 0;i < NSCOUNT6;i++) {
+        if (!NSSOCKADDR6(i))
+          continue;
 	if ( addrcmp( (void *) &(NSSOCKADDR6(i)->sin6_addr),
 		      (void *) &(from6->sin6_addr), AF_INET6 ) == 0 )
 	  break;