From fb9b3b62c02427b80657056805a9bac7756c98b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 7 Mar 2016 13:37:45 +0100
Subject: [PATCH] network: use `qubes-primary-dns` QubesDB entry if present

For a long time the DNS address was the same as default gateway. This is
still the case in R3.x, but using `qubes-gateway` configuration
parameter for it is misleading. It should be up to dom0 to provide DNS
address (whether the value is the same as gateway or not).

Fixes QubesOS/qubes-issues#1817
---
 network/setup-ip                  | 8 +++++---
 vm-init.d/qubes-core-netvm        | 3 ++-
 vm-systemd/network-proxy-setup.sh | 3 ++-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/network/setup-ip b/network/setup-ip
index 07071d7..5dbec79 100755
--- a/network/setup-ip
+++ b/network/setup-ip
@@ -13,6 +13,7 @@ ip=`/usr/bin/qubesdb-read /qubes-ip 2> /dev/null`
 if [ x$ip != x ]; then
     netmask=`/usr/bin/qubesdb-read /qubes-netmask`
     gateway=`/usr/bin/qubesdb-read /qubes-gateway`
+    primary_dns=`/usr/bin/qubesdb-read /qubes-primary-dns 2>/dev/null || echo $gateway`
     secondary_dns=`/usr/bin/qubesdb-read /qubes-secondary-dns`
     /sbin/ethtool -K $INTERFACE sg off
     /sbin/ethtool -K $INTERFACE tx off
@@ -39,7 +40,7 @@ method=manual
 may-fail=false
 __EOF__
         if [ "x$disabledns" != "x1" ]; then
-            echo "dns=$gateway;$secondary_dns" >> $nm_config
+            echo "dns=$primary_dns;$secondary_dns" >> $nm_config
         fi
         if [ "x$disablegw" != "x1" ]; then
             echo "addresses1=$ip;32;$gateway" >> $nm_config
@@ -58,7 +59,7 @@ __EOF__
         if ! grep -rq "^/etc/resolv[.]conf$" "${PROTECTED_FILE_LIST}" 2>/dev/null; then
         echo > /etc/resolv.conf
             if [ "x$disabledns" != "x1" ]; then
-                echo "nameserver $gateway" > /etc/resolv.conf
+                echo "nameserver $primary_dns" > /etc/resolv.conf
                 echo "nameserver $secondary_dns" >> /etc/resolv.conf
             fi
         fi
@@ -67,8 +68,9 @@ __EOF__
     if [ "x$network" != "x" ] && [ "x$disabledns" != "x1" ]; then
         gateway=$(qubesdb-read /qubes-netvm-gateway)
         netmask=$(qubesdb-read /qubes-netvm-netmask)
+        primary_dns=$(qubesdb-read /qubes-netvm-primary-dns 2>/dev/null || echo $gateway)
         secondary_dns=$(qubesdb-read /qubes-netvm-secondary-dns)
-        echo "NS1=$gateway" > /var/run/qubes/qubes-ns
+        echo "NS1=$primary_dns" > /var/run/qubes/qubes-ns
         echo "NS2=$secondary_dns" >> /var/run/qubes/qubes-ns
         /usr/lib/qubes/qubes-setup-dnat-to-ns
     fi
diff --git a/vm-init.d/qubes-core-netvm b/vm-init.d/qubes-core-netvm
index 61fdbd9..b3d7bd1 100755
--- a/vm-init.d/qubes-core-netvm
+++ b/vm-init.d/qubes-core-netvm
@@ -26,9 +26,10 @@ start()
 	if [ "x$network" != "x" ]; then
 		gateway=$(/usr/bin/qubesdb-read /qubes-netvm-gateway)
 		netmask=$(/usr/bin/qubesdb-read /qubes-netvm-netmask)
+		primary_dns=$(/usr/bin/qubesdb-read /qubes-netvm-primary-dns || echo $gateway)
 		secondary_dns=$(/usr/bin/qubesdb-read /qubes-netvm-secondary-dns)
 		modprobe netbk 2> /dev/null || modprobe xen-netback
-		echo "NS1=$gateway" > /var/run/qubes/qubes-ns
+		echo "NS1=$primary_dns" > /var/run/qubes/qubes-ns
 		echo "NS2=$secondary_dns" >> /var/run/qubes/qubes-ns
 		/usr/lib/qubes/qubes-setup-dnat-to-ns
 		echo "1" > /proc/sys/net/ipv4/ip_forward
diff --git a/vm-systemd/network-proxy-setup.sh b/vm-systemd/network-proxy-setup.sh
index 503c827..78512c9 100755
--- a/vm-systemd/network-proxy-setup.sh
+++ b/vm-systemd/network-proxy-setup.sh
@@ -12,9 +12,10 @@ if [ "x$network" != "x" ]; then
 
     gateway=$(qubesdb-read /qubes-netvm-gateway)
     netmask=$(qubesdb-read /qubes-netvm-netmask)
+    primary_dns=$(qubesdb-read /qubes-netvm-primary-dns 2>/dev/null || echo $gateway)
     secondary_dns=$(qubesdb-read /qubes-netvm-secondary-dns)
     modprobe netbk 2> /dev/null || modprobe xen-netback || "${modprobe_fail_cmd}"
-    echo "NS1=$gateway" > /var/run/qubes/qubes-ns
+    echo "NS1=$primary_dns" > /var/run/qubes/qubes-ns
     echo "NS2=$secondary_dns" >> /var/run/qubes/qubes-ns
     /usr/lib/qubes/qubes-setup-dnat-to-ns
     echo "1" > /proc/sys/net/ipv4/ip_forward