=> Modified vyatta_update_resolv.pl to update (i.e. add and remove) 'name-server' and 'domain-name-server' options

   in /etc/resolv.conf received by a dhcp client for an interface
=> Modified name-server/node.def so as to have the name-server set by our CLI on the top of
   /etc/resolv.conf to take priority over name-servers received from dhcp client

2 files changed, 107 insertions, 6 deletions

diff --git a/scripts/system/vyatta_update_resolv.pl b/scripts/system/vyatta_update_resolv.pl
index a725a16e..b35cae4a 100755
--- a/scripts/system/vyatta_update_resolv.pl
+++ b/scripts/system/vyatta_update_resolv.pl
@@ -30,7 +30,8 @@ use lib "/opt/vyatta/share/perl5/";
 use Getopt::Long;
 my $change_dir = '';
 my $modify_dir = '';
-GetOptions("change_dir=s" => \$change_dir, "modify_dir=s" => \$modify_dir);
+my $dhclient_script = 0;
+GetOptions("change_dir=s" => \$change_dir, "modify_dir=s" => \$modify_dir, "dhclient-script=i" => \$dhclient_script );
 
 
 use VyattaConfig;
@@ -45,11 +46,19 @@ if ($modify_dir ne '') {
 
 
 $vc->setLevel('system');
+my @domains;
+my $domain_name = undef;
+
+if ($dhclient_script == 1) {
+   $vc->{_active_dir_base} = "/opt/vyatta/config/active/";
+   @domains = $vc->returnOrigValues('domain-search domain');
+   $domain_name = $vc->returnOrigValue('domain-name');
+} else {
+   @domains = $vc->returnValues('domain-search domain');
+   $domain_name = $vc->returnValue('domain-name');
+}
 
-my @domains = $vc->returnValues('domain-search domain');
-my $domain_name = $vc->returnValue('domain-name');
-
-if (@domains > 0 && $domain_name && length($domain_name) > 0) {
+if ($dhclient_script == 0 && @domains > 0 && $domain_name && length($domain_name) > 0) {
 	print STDERR "System configuration error.  Both \'domain-name\' and \'domain-search\' are specified, but only one of these mutually exclusive parameters is allowed.\n";
 	print STDERR "System configuration commit aborted due to error(s).\n";
 	exit(1);
@@ -63,6 +72,24 @@ foreach my $domain (@domains) {
 	$doms .= $domain;
 }
 
+# add domain names received from dhcp client to domain search in /etc/resolv.conf if domain-name not set in CLI
+if (!defined($domain_name)) {
+  my @dhcp_interfaces_resolv_files = `ls /etc/ | grep dhclient.new`;
+  if ($#dhcp_interfaces_resolv_files >= 0) {
+    for my $each_file (@dhcp_interfaces_resolv_files) {
+       chomp $each_file;
+       my $find_search = `grep search /etc/$each_file 2> /dev/null | wc -l`;
+       if ($find_search == 1) {
+            my $search_string = `grep search /etc/$each_file`;
+            my @dhcp_domains = split(/ /, $search_string, 2);
+            my $dhcp_domain = $dhcp_domains[1];
+            chomp $dhcp_domain;
+            $doms .= ' ' . $dhcp_domain;
+       }
+    }
+  }
+}
+
 my $search = '';
 if (length($doms) > 0) {
 	$search = "search\t\t$doms\t\t#line generated by $0\n";
@@ -73,6 +100,78 @@ if ($domain_name && length($domain_name) > 0) {
 	$domain = "domain\t\t$domain_name\t\t#line generated by $0\n";
 }
 
+# update /etc/resolv.conf for name-servers received from dhcp client, only done when dhclient-script calls this script
+if ($dhclient_script == 1) {
+  my @current_dhcp_nameservers;
+  my $restart_ntp = 0;
+
+  # code below to add new name-servers received from dhcp client
+
+  my @dhcp_interfaces_resolv_files = `ls /etc/ | grep dhclient.new`;
+  if ($#dhcp_interfaces_resolv_files >= 0) {
+    my $ns_count = 0;
+    for my $each_file (@dhcp_interfaces_resolv_files) {
+       chomp $each_file;
+       my $find_nameserver = `grep nameserver /etc/$each_file 2> /dev/null | wc -l`;
+       if ($find_nameserver > 0) {
+            my @nameservers = `grep nameserver /etc/$each_file`;
+            for my $each_nameserver (@nameservers) {
+               my @nameserver = split(/ /, $each_nameserver, 2);
+               my $ns = $nameserver[1];
+               chomp $ns;
+               $current_dhcp_nameservers[$ns_count] = $ns;
+               $ns_count++;
+               my $search_ns_in_resolvconf = `grep $ns /etc/resolv.conf 2> /dev/null | wc -l`;
+               if ($search_ns_in_resolvconf == 0) {
+                 open (APPEND, ">>/etc/resolv.conf") or die "$! error trying to overwrite";
+                 print APPEND "nameserver\t$ns\t\t#nameserver written by $0\n";
+                 close (APPEND);
+                 $restart_ntp = 1;
+               }
+            }
+       }
+    }
+  }
+
+  # code below to remove old name-servers from /etc/resolv.conf that were not received in this response from dhcp-server
+
+  my @nameservers_dhcp_in_resolvconf = `grep 'nameserver written' /etc/resolv.conf`;
+  my @dhcp_nameservers_in_resolvconf;
+  my $count_nameservers_in_resolvconf = 0;
+  for my $count_dhcp_nameserver (@nameservers_dhcp_in_resolvconf) {
+     my @dhcp_nameserver = split(/\t/, $count_dhcp_nameserver, 3);
+     $dhcp_nameservers_in_resolvconf[$count_nameservers_in_resolvconf] = $dhcp_nameserver[1];
+     $count_nameservers_in_resolvconf++;
+  }
+  if ($#current_dhcp_nameservers < 0) {
+    for my $dhcpnameserver (@dhcp_nameservers_in_resolvconf) {
+        my $cmd = "sed -i '/$dhcpnameserver/d' /etc/resolv.conf";
+        system($cmd);
+        $restart_ntp = 1;
+    }
+  } else {
+         for my $dhcpnameserver (@dhcp_nameservers_in_resolvconf) {
+            my $found = 0;
+            for my $currentnameserver (@current_dhcp_nameservers) {
+               if ($dhcpnameserver eq $currentnameserver){
+                  $found = 1;
+               }
+            }
+            if ($found == 0) {
+              my $cmd = "sed -i '/$dhcpnameserver/d' /etc/resolv.conf";
+              system($cmd);
+              $restart_ntp = 1;
+            }
+
+        }
+   }
+ if ($restart_ntp == 1) {
+     # this corresponds to what is done in name-server/node.def as a fix for bug 1300
+     my $cmd_ntp_restart = "if [ -f /etc/ntp.conf ] && grep -q 'server' /etc/ntp.conf; then /usr/sbin/invoke-rc.d ntp restart >&/dev/null; fi &";
+     system($cmd_ntp_restart);
+ }
+}
+
 
 # The following will re-write '/etc/resolv.conf' line by line,
 # replacing the 'search' specifier with the latest values,
diff --git a/templates/system/name-server/node.def b/templates/system/name-server/node.def
index 0ed43351..3866e82c 100644
--- a/templates/system/name-server/node.def
+++ b/templates/system/name-server/node.def
@@ -5,7 +5,9 @@ update:expression: "sudo sh -c \"touch /etc/resolv.conf && \
 if grep -q '$VAR(@)' /etc/resolv.conf; then \
   exit 0; \
 else \
-  echo \\\"nameserver\t $VAR(@)\\\" >> /etc/resolv.conf; \
+  mv -f /etc/resolv.conf /etc/old_resolv.conf && \
+  echo \\\"nameserver\t $VAR(@)\\\" >> /etc/resolv.conf && \
+  cat /etc/old_resolv.conf >>  /etc/resolv.conf; \
 fi && \
 if [ -f /etc/ntp.conf ] && grep -q 'server' /etc/ntp.conf; then \
   /usr/sbin/invoke-rc.d ntp restart >&/dev/null; \