Allow for xrdp not being able to delete PID file

If xrdp is running with dropped privileges it won't be able to delete
the PID file it's created. Places where xrdp is stopped need to cater
for this.

It's prefereable to do this than make the PID file writeable by xrdp
with dropped privileges, as this can still lead to DoS attacks if an
attacker manages to modify the PID file from a compromised xrdp
process.

instfiles/Makefile.am

@@ -98,6 +98,9 @@ endif
 if FREEBSD
 # must be tab below
 install-data-hook:
-	sed -i '' 's|%%PREFIX%%|$(prefix)|g' $(DESTDIR)$(sysconfdir)/rc.d/xrdp \
-                                         $(DESTDIR)$(sysconfdir)/rc.d/xrdp-sesman
+	sed -e 's|%%PREFIX%%|$(prefix)|g' \
+	    -e 's|%%LOCALSTATEDIR%%|$(localstatedir)|g' \
+		-i '' \
+		$(DESTDIR)$(sysconfdir)/rc.d/xrdp \
+		$(DESTDIR)$(sysconfdir)/rc.d/xrdp-sesman
 endif

instfiles/init.d/xrdp

@@ -116,7 +116,7 @@ case "$1" in
         log_progress_msg $NAME
         if pidofproc -p  $PIDDIR/$NAME.pid $DAEMON  > /dev/null; then
             start-stop-daemon --stop --quiet --oknodo --pidfile $PIDDIR/$NAME.pid \
-	    --exec $DAEMON
+	    --remove-pidfile --exec $DAEMON
             value=$?
             [ $value -gt 0 ] && exitval=$value
         else

instfiles/rc.d/xrdp

@@ -48,6 +48,7 @@ command="%%PREFIX%%/sbin/xrdp"
 allstart_cmd="xrdp_allstart"
 allstop_cmd="xrdp_allstop"
 allrestart_cmd="xrdp_allrestart"
+stop_postcmd="xrdp_poststop"
 
 xrdp_allstart()
 {
@@ -79,4 +80,10 @@ xrdp_allrestart()
     run_rc_command "restart"
 }
 
+xrdp_poststop()
+{
+    # If running with dropped privileges, xrdp can't delete its own
+    # PID file
+    rm -f %%LOCALSTATEDIR%%/run/xrdp.pid
+}
 run_rc_command "$1"