dns: iterate over all configured nameservers

Previously if there were three nameservers configured and third one was
reachable via IPv6 we didn't sent query to it, since NSCOUNT6 was equal to
one. Clearly it was the original intention to sent query to all IPv6
nameservers.

Reported-by: Benedikt Gollatz <benedikt@gollatz.net>

Resolves: #966174

mtr-query-all-ipv6-nameservers.patch

@@ -0,0 +1,57 @@
+From eae1b58c5a9f074f79a0edfaeb1cf7a4e77a34cb Mon Sep 17 00:00:00 2001
+From: Michal Sekletar <sekletar.m@gmail.com>
+Date: Tue, 24 Sep 2013 12:56:11 +0200
+Subject: [PATCH] dns: iterate over all configured nameservers
+
+Previously if there were three nameservers configured and third one was
+reachable via IPv6 we didn't sent query to it, since NSCOUNT6 was equal to
+one. Clearly it was the original intention to sent query to all IPv6
+nameservers.
+
+Reported-by: Benedikt Gollatz <benedikt@gollatz.net>
+---
+ dns.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/dns.c b/dns.c
+index 221665d..e89fd4b 100644
+--- a/dns.c
++++ b/dns.c
+@@ -938,7 +938,7 @@ void dorequest(char *s,int type,word id)
+   hp->id = id;	/* htons() deliberately left out (redundant) */
+ #ifdef ENABLE_IPV6
+   if (resfd6 > 0) {
+-    for (i = 0;i < NSCOUNT6;i++) {
++    for (i = 0;i < myres.nscount;i++) {
+       if (!NSSOCKADDR6(i))
+ 	continue;
+       if (NSSOCKADDR6(i)->sin6_family == AF_INET6)
+@@ -1342,7 +1342,7 @@ void dns_ack6(void)
+     /* Check to see if this server is actually one we sent to */
+     if ( addrcmp( (void *) &(from6->sin6_addr), (void *) &localhost6,
+                   (int) AF_INET6 ) == 0 ) {
+-      for (i = 0;i < NSCOUNT6;i++) {
++      for (i = 0;i < myres.nscount;i++) {
+         if (!NSSOCKADDR6(i))
+           continue;
+ 
+@@ -1353,14 +1353,14 @@ void dns_ack6(void)
+ 	  break;
+       }
+     } else
+-      for (i = 0;i < NSCOUNT6;i++) {
++      for (i = 0;i < myres.nscount;i++) {
+         if (!NSSOCKADDR6(i))
+           continue;
+ 	if ( addrcmp( (void *) &(NSSOCKADDR6(i)->sin6_addr),
+ 		      (void *) &(from6->sin6_addr), AF_INET6 ) == 0 )
+ 	  break;
+       }
+-    if (i == NSCOUNT6) {
++    if (i == myres.nscount) {
+       snprintf(tempstring, sizeof(tempstring), 
+ 	       "Resolver error: Received reply from unknown source: %s",
+ 	       inet_ntop( AF_INET6, &(from6->sin6_addr), addrstr,
+-- 
+1.8.3.1
+

mtr.spec

@@ -20,6 +20,7 @@ Patch2: mtr-xml-format-fixes.patch
 Patch3: mtr-default-hostname.patch
 Patch4: mtr-ipv6-on-ipv4-only.patch
 Patch5: mtr-introduce-grace-period.patch
+Patch6: mtr-query-all-ipv6-nameservers.patch
 
 BuildRequires: ncurses-devel gtk2-devel desktop-file-utils
 BuildRequires: autoconf automake libtool
@@ -47,6 +48,7 @@ diagnostic tool.
 %patch3 -p1
 %patch4 -p1
 %patch5 -p1
+%patch6 -p1
 
 %build
 export CFLAGS="%{optflags} -fPIE"
@@ -95,6 +97,7 @@ desktop-file-install \
 - migrate from consolehelper to policykit (#502750)
 - specfile cleanup
 - introduce grace period (#1009051)
+- query all ipv6 nameservers (#966174)
 
 * Sat Sep 14 2013 Michal Sekletar <msekleta@redhat.com> - 2:0.85-3
 - enable hardened build