dnsmasq: steal resolvconf support from Ubuntu

Add support for resolvconf integration as done in Ubuntu. This implies
updates of start-scripts, resolvconf plugin (on nameserver update ...),
populate-volatiles control file for saved nameserver list.

Signed-off-by: Jens Rehsack <sno@netbsd.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

5 files changed, 167 insertions, 4 deletions

diff --git a/meta-networking/recipes-support/dnsmasq/dnsmasq.inc b/meta-networking/recipes-support/dnsmasq/dnsmasq.inc
index 7fec60678..622e63067 100644
--- a/meta-networking/recipes-support/dnsmasq/dnsmasq.inc
+++ b/meta-networking/recipes-support/dnsmasq/dnsmasq.inc
@@ -23,6 +23,7 @@ PACKAGECONFIG[dbus] = ",,dbus"
 PACKAGECONFIG[idn] = ",,libidn"
 PACKAGECONFIG[conntrack] = ",,libnetfilter-conntrack"
 PACKAGECONFIG[lua] = ",,lua"
+PACKAGECONFIG[resolvconf] = ",,,resolvconf"
 EXTRA_OEMAKE = "\
     'COPTS=${@base_contains('PACKAGECONFIG', 'dbus', '-DHAVE_DBUS', '', d)} \
            ${@base_contains('PACKAGECONFIG', 'idn', '-DHAVE_IDN', '', d)} \
@@ -32,6 +33,8 @@ EXTRA_OEMAKE = "\
     'LDFLAGS=${LDFLAGS}' \
 "
 
+SRC_URI += "${@bb.utils.contains('PACKAGECONFIG', 'resolvconf', 'file://dnsmasq.resolvconf file://99_dnsmasq', '', d)}"
+
 do_compile_append() {
     # build dhcp_release
     cd ${S}/contrib/wrt
@@ -56,6 +59,13 @@ do_install () {
         install -d ${D}${sysconfdir}/dbus-1/system.d
         install -m 644 dbus/dnsmasq.conf ${D}${sysconfdir}/dbus-1/system.d/
     fi
+    if [ "${@base_contains('PACKAGECONFIG', 'resolvconf', 'resolvconf', '', d)}" != "" ]; then
+        install -d ${D}${sysconfdir}/resolvconf/update.d/
+        install -m 0755 ${WORKDIR}/dnsmasq.resolvconf ${D}${sysconfdir}/resolvconf/update.d/dnsmasq
+
+        install -d ${D}${sysconfdir}/default/volatiles
+        install -m 0644 ${WORKDIR}/99_dnsmasq ${D}${sysconfdir}/default/volatiles
+    fi
 }
 
 CONFFILES_${PN} = "${sysconfdir}/dnsmasq.conf"
diff --git a/meta-networking/recipes-support/dnsmasq/files/99_dnsmasq b/meta-networking/recipes-support/dnsmasq/files/99_dnsmasq
new file mode 100644
index 000000000..f52ce4e8f
--- /dev/null
+++ b/meta-networking/recipes-support/dnsmasq/files/99_dnsmasq
@@ -0,0 +1 @@
+d root root 0755 /run/dnsmasq none
diff --git a/meta-networking/recipes-support/dnsmasq/files/dnsmasq.resolvconf b/meta-networking/recipes-support/dnsmasq/files/dnsmasq.resolvconf
new file mode 100755
index 000000000..06cd25cec
--- /dev/null
+++ b/meta-networking/recipes-support/dnsmasq/files/dnsmasq.resolvconf
@@ -0,0 +1,84 @@
+#!/bin/sh
+#
+# Script to update the resolver list for dnsmasq
+#
+# N.B. Resolvconf may run us even if dnsmasq is not (yet) running.
+# If dnsmasq is installed then we go ahead and update the resolver list
+# in case dnsmasq is started later.
+#
+# Assumption: On entry, PWD contains the resolv.conf-type files.
+#
+# This file is part of the dnsmasq package.
+#
+
+set -e
+
+RUN_DIR="/run/dnsmasq"
+RSLVRLIST_FILE="${RUN_DIR}/resolv.conf"
+TMP_FILE="${RSLVRLIST_FILE}_new.$$"
+MY_NAME_FOR_RESOLVCONF="dnsmasq"
+
+[ -x /usr/bin/dnsmasq ] || exit 0
+[ -x /lib/resolvconf/list-records ] || exit 1
+
+PATH=/bin:/sbin
+
+report_err() { echo "$0: Error: $*" >&2 ; }
+
+# Stores arguments (minus duplicates) in RSLT, separated by spaces
+# Doesn't work properly if an argument itself contains whitespace
+uniquify()
+{
+        RSLT=""
+        while [ "$1" ] ; do
+                for E in $RSLT ; do
+                        [ "$1" = "$E" ] && { shift ; continue 2 ; }
+                done
+                RSLT="${RSLT:+$RSLT }$1"
+                shift
+        done
+}
+
+if [ ! -d "$RUN_DIR" ] && ! mkdir --parents --mode=0755 "$RUN_DIR" ; then
+        report_err "Failed trying to create directory $RUN_DIR"
+        exit 1
+fi
+
+RSLVCNFFILES=""
+for F in $(/lib/resolvconf/list-records --after "lo.$MY_NAME_FOR_RESOLVCONF") ; do
+        case "$F" in
+            "lo.$MY_NAME_FOR_RESOLVCONF")
+                # Omit own record
+                ;;
+            lo.*)
+                # Include no more records after one for a local nameserver
+                RSLVCNFFILES="${RSLVCNFFILES:+$RSLVCNFFILES }$F"
+                break
+                ;;
+          *)
+                RSLVCNFFILES="${RSLVCNFFILES:+$RSLVCNFFILES }$F"
+                ;;
+        esac
+done
+
+NMSRVRS=""
+if [ "$RSLVCNFFILES" ] ; then
+        uniquify $(sed -n -e 's/^[[:space:]]*nameserver[[:space:]]\+//p' $RSLVCNFFILES)
+        NMSRVRS="$RSLT"
+fi
+
+# Dnsmasq uses the mtime of $RSLVRLIST_FILE, with a resolution of one second,
+# to detect changes in the file. This means that if a resolvconf update occurs
+# within one second of the previous one then dnsmasq may fail to notice the
+# more recent change. To work around this problem we sleep one second here
+# if necessary in order to ensure that the new mtime is different.
+if [ -f "$RSLVRLIST_FILE" ] && [ "$(stat -c %X "$RSLVRLIST_FILE")" = "$(date +%s)" ] ; then
+        sleep 1
+fi
+
+clean_up() { rm -f "$TMP_FILE" ; }
+trap clean_up EXIT
+: >| "$TMP_FILE"
+for N in $NMSRVRS ; do echo "nameserver $N" >> "$TMP_FILE" ; done
+mv -f "$TMP_FILE" "$RSLVRLIST_FILE"
+
diff --git a/meta-networking/recipes-support/dnsmasq/files/dnsmasq.service b/meta-networking/recipes-support/dnsmasq/files/dnsmasq.service
index 549e15e2b..c3637e142 100644
--- a/meta-networking/recipes-support/dnsmasq/files/dnsmasq.service
+++ b/meta-networking/recipes-support/dnsmasq/files/dnsmasq.service
@@ -5,8 +5,11 @@ After=network.target
 [Service]
 Type=forking
 PIDFile=/run/dnsmasq.pid
-ExecStart=/usr/bin/dnsmasq -x /run/dnsmasq.pid
-ExecReload=/bin/kill -HUP $(/bin/cat /run/dnsmasq.pid)
+ExecStartPre=/usr/sbin/dnsmasq --test
+ExecStart=/etc/init.d/dnsmasq systemd-exec
+ExecStartPost=/etc/init.d/dnsmasq systemd-start-resolvconf
+ExecStopPre=/etc/init.d/dnsmasq systemd-stop-resolvconf
+ExecReload=/bin/kill -HUP $MAINPID
 
 [Install]
 WantedBy=multi-user.target
diff --git a/meta-networking/recipes-support/dnsmasq/files/init b/meta-networking/recipes-support/dnsmasq/files/init
index d1aa9e517..51c95dfed 100644
--- a/meta-networking/recipes-support/dnsmasq/files/init
+++ b/meta-networking/recipes-support/dnsmasq/files/init
@@ -8,15 +8,68 @@ test -f $DAEMON || exit 0
 
 set -e
 
+if [ -r /etc/default/$NAME ]
+then
+        . /etc/default/$NAME
+fi
+
+DNSMASQ_CONF="/etc/dnsmasq.conf"
+test "/etc/dnsmasq.d/*" != '/etc/dnsmasq.d/*' && DNSMASQ_CONF="${DNSMASQ_CONF} /etc/dnsmasq.d/*"
+
+test -z "${PIDFILE}" && PIFILE="/run/dnsmasq.pid"
+
+if [ -z "$IGNORE_RESOLVCONF" ]
+then
+        egrep -h -q '^no-resolv' ${DNSMASQ_CONF} && IGNORE_RESOLVCONF="yes"
+fi
+
+# RESOLV_CONF:
+# If the resolvconf package is installed then use the resolv conf file
+# that it provides as the default.  Otherwise use /etc/resolv.conf as
+# the default.
+#
+# If IGNORE_RESOLVCONF is set in /etc/default/dnsmasq or an explicit
+# filename is set there then this inhibits the use of the resolvconf-provided
+# information.
+#
+# Note that if the resolvconf package is installed it is not possible to
+# override it just by configuration in /etc/dnsmasq.conf, it is necessary
+# to set IGNORE_RESOLVCONF=yes in /etc/default/dnsmasq.
+
+test -z "$RESOLV_CONF" -a "$IGNORE_RESOLVCONF" != "yes" -a -x /sbin/resolvconf && \
+        RESOLV_CONF=/run/dnsmasq/resolv.conf
+
+start_resolvconf()
+{
+        if [ "$IGNORE_RESOLVCONF" != "yes" -a -x /sbin/resolvconf ]
+        then
+                echo "nameserver 127.0.0.1" | /sbin/resolvconf -a lo.$NAME
+        fi
+        :
+}
+
+stop_resolvconf()
+{
+        if [ "$IGNORE_RESOLVCONF" != "yes" -a -x /sbin/resolvconf ]
+        then
+                /sbin/resolvconf -d lo.$NAME
+        fi
+        :
+}
+
 case "$1" in
     start)
         echo -n "starting $DESC: $NAME... "
         test -d /var/lib/misc/ || mkdir /var/lib/misc/
-        start-stop-daemon -S -x $DAEMON -- $ARGS
+        start-stop-daemon -S -x $DAEMON -- $ARGS \
+                ${RESOLV_CONF:+ -r $RESOLV_CONF} \
+                ${PIDFILE:+ -x $PIDFILE}
+        test $? -eq 0 && start_resolvconf
         echo "done."
         ;;
     stop)
         echo -n "stopping $DESC: $NAME... "
+        stop_resolvconf
         start-stop-daemon -K -x $DAEMON
         echo "done."
         ;;
@@ -25,7 +78,7 @@ case "$1" in
         start-stop-daemon -q -K -t -x $DAEMON
         RET=$?
         if [ "$RET" = "0" ]; then
-                PID=`cat /var/run/dnsmasq.pid`
+                PID=`cat ${PIDFILE}`
                 echo "($PID) is running"
         else
                 echo "is not running"
@@ -43,6 +96,18 @@ case "$1" in
         killall -HUP $(basename ${DAEMON})
         echo "done."
         ;;
+    systemd-start-resolvconf)
+        start_resolvconf
+        ;;
+    systemd-stop-resolvconf)
+        stop_resolvconf
+        ;;
+    systemd-exec)
+        test -d /var/lib/misc/ || mkdir /var/lib/misc/
+        exec $DAEMON --keep-in-foreground $ARGS \
+                ${RESOLV_CONF:+ -r $RESOLV_CONF} \
+                ${PIDFILE:+ -x $PIDFILE}
+        ;;
     *)
         echo "Usage: $0 {start|stop|status|restart|reload}"
         exit 1