Teach osx-randmac to randomize everyday.

README.rst

@@ -91,8 +91,8 @@ to launchd control.::
     osx-ipfw.sh       Enable ipfw(8) with a default set of secure rules
     osx-noatime.sh    Enable noatime mounts on all disks
     osx-ramfs.sh      Put /tmp and /var/run under a RAMFS
-    osx-randmac.sh    Randomize your MAC address at every boot. Designed to auto-detect your wifi
-                      interface and use it with that.
+    osx-randmac.sh    Randomize your MAC address every day. Designed to auto-detect your wifi
+                      interface. Run it without any args to see usage.
     osx-tuntap.sh     Make your tun-tap driver persistent.
 
 

osx-randmac.sh

@@ -2,7 +2,13 @@
 
 #
 # Setup OS X with a random mac address for WiFi or a specific
-# interface.
+# interface. The MAC address on the specified iface is randomized
+# every day (24 hours). This script uses a systemwide LaunchAgent to
+# trigger the periodic MAC refresh.
+#
+# Author: Sudhi Herle <sudhi-at-herle-net>
+# (c) Sudhi Herle 2013-2016
+# License: GPLv2
 #
 # Order of doing things
 #  - disassociate from any network
@@ -16,10 +22,38 @@ airport=/System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport
 net=/usr/sbin/networksetup
 ipconfig=/usr/sbin/ipconfig
 Z=`basename $0`
+DATE=/bin/date
+STAT=/usr/bin/stat
+TOUCH=/usr/bin/touch
+PROG=$0
+Me=`id -u`
+
+# Debug hook
+#e=echo
+
+Installdir=/Library/LaunchDaemons
+Bindir=/usr/sbin
 
 PATH=/sbin:/usr/sbin:/bin:/usr/bin:$PATH
 export PATH
 
+
+function die {
+    echo "$Z: $@" 1>&2
+    exit 1
+}
+
+
+if [ $Me -ne 0 ]; then
+    echo "$Z: Need root privilege to install system-wide; switching to dry-run mode .."
+    Installdir=/tmp/LaunchAgents
+    Bindir=/tmp/bin
+    e=echo
+
+    mkdir -p $Installdir $Bindir
+fi
+
+
 #set -x
 
 # First dump existing config to stderr
@@ -29,15 +63,15 @@ function usage {
     cat 1>&2 <<EOF1
 $Z - Randomize MAC address of OS X WiFi (or any given interface).
 
-Usage: $Z start|update|stop|restartinstall [IFACE]
+Usage: $Z start|update|stop|restart|install [IFACE]
 
 If no interface is specified, the script automatically detects and
 uses the WiFi interface. Description of actions:
 
 start, update: Update MAC Address
 stop:    No Op
 restart: No op
-install: Creates a system startup file in /System/Library/LaunchDaemons/$FNAME.plist
+install: Creates a launchd file in /Library/LaunchDaemons
 EOF1
 
     exit 1
@@ -47,50 +81,25 @@ uname=`uname`
 case $uname in
     Darwin);;
 
-    *) echo "$0: This script is meant for Mac OS X only." 1>&2
-       exit 1
+    *) die "This script is meant for Mac OS X only."
        ;;
 esac
 
 action=$1
-if [ -z "$action" ]; then
-    usage
-    exit 1
-fi
+test -n "$action" || usage
 shift
 
-# Ideally, this should be installed at the system wide level.
-# If you install it on a per-user basis, make sure you tie it to laptop lid-wake events.
-# sleepwatcher is your friend.
-systemwide=1
-
-if [ -n "$systemwide" ]; then
-    installdir=/System/Library/LaunchDaemons
-    bindir=/usr/sbin
-else
-    installdir=/Library/LaunchDaemons
-    bindir=/etc
-fi
-
-
-
-me=`id -u`
-if [ $me -ne 0 ]; then
-    echo "$Z: Need root privilege to run; switching to dry-run mode .."
-    e=echo
-fi
+function writelog {
+    $e logger -p "daemon.info" -t "${FNAME}" "$@"
+}
 
-#set -x
 
 function grok_wifi_darwin {
     typeset iface=$1
 
     if [ -n "$iface" ]; then
         n=$(ifconfig $iface 2>/dev/null | wc -l)
-        if [ $n -eq 0 ]; then
-            echo "$Z: $iface is not a network interface?" 1>&2
-            exit 2
-        fi
+        test $n -gt 0 || die "$iface is not a network interface?"
     else
         # grok the wifi interface
 
@@ -99,25 +108,17 @@ function grok_wifi_darwin {
 
         if [ -z "$xx" ]; then
             echo list | scutil 1>&2
-            echo "$Z: Whoa. Can't find any WiFi interface!" 1>&2
-            exit 1
+            die "Whoa. Can't find any WiFi interface!"
         fi
 
         typeset dx=`dirname $xx`
         iface=`basename $dx`
-
-        if [ -z "$iface" ]; then
-            echo "$Z: Can't grok WiFi Interface. Are you connected via WiFi?" 1>&2
-            exit 1
-        fi
+        test -n "$iface" || die "Can't grok WiFi Interface. Are you connected via WiFi?"
     fi
 
     # Now, lets make sure this is really a wireless interface
     xx=`$net -getairportnetwork $iface`
-    if [ $? -ne 0 ]; then
-        echo "$Z: $iface doesn't look like a WiFi interface.." 1>&2
-        exit 1
-    fi
+    test $? -eq 0 || die "$iface doesn't look like a WiFi interface.."
 
     echo $iface
 }
@@ -151,18 +152,14 @@ function wait_wifi_darwin {
 
         # Now, lets make sure this is really a wireless interface
         xx=`$net -getairportnetwork $iface`
-        if [ $? -ne 0 ]; then
-            echo "$Z: $iface doesn't look like a WiFi interface.." 1>&2
-            exit 1
-        fi
+        test $? -eq 0 || die "$iface doesn't look like a WiFi interface.."
 
         echo $iface
         return 0
 
     done
 
-    echo "$Z: Can't grok WiFi interface after 10 tries!" 1>&2
-    exit 1
+    die "Can't grok WiFi interface after 10 tries!"
 }
 
 
@@ -171,10 +168,7 @@ function verify_wifi_Darwin {
     typeset iface=$1
     typeset x=`echo list | scutil | grep "State:/Network/Interface/$iface/AirPort"`
 
-    if [ -z "$x" ]; then
-        echo "$Z: $iface is not a WiFi interface" 1>&2
-        return 1
-    fi
+    test -n "$x" || die "$iface is not a WiFi interface"
     $e ifconfig $iface down
     return 0
 }
@@ -205,6 +199,7 @@ function _randmac {
     echo "$pref:$a1:$a2:$a3"
 }
 
+
 function update_mac {
     typeset iface=$1
     typeset mac=$(_randmac)
@@ -225,28 +220,28 @@ function update_mac {
 
     $e $net -detectnewhardware
 
+    $e writelog "$iface: MAC updated to $mac"
+
     return 0
 }
 
 
 # Installs a startup service
 function install_service {
+    typeset iface=$1
+    typeset fname=${2}.$iface
     typeset bn=`basename $Z`
-    typeset prog=$bindir/$bn
+    typeset prog=$Bindir/$bn
 
-    if [ $me -ne 0 ]; then
-        installdir=/tmp
-    fi
-
-    typeset file=$installdir/${FNAME}.plist
+    typeset file=$Installdir/${fname}.plist
 
     cat > $file <<EOF2
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
     <key>Label</key>
-    <string>$FNAME</string>
+    <string>$fname</string>
 
     <key>Disabled</key>
     <false/>
@@ -260,55 +255,72 @@ function install_service {
     <key>KeepAlive</key>
     <false/>
 
+    <key>Debug</key>
+    <false/>
+
     <key>RunAtLoad</key>
     <true/>
 
+    <key>AbandonProcessGroup</key>
+    <true/>
+
+    <!-- Randomize the MAC at 0600 every day -->
+
+    <key>StartCalendarInterval</key>
+    <dict>
+        <key>Minute</key>
+        <integer>0</integer>
+
+        <key>Hour</key>
+        <integer>6</integer>
+    </dict>
+
     <key>ProgramArguments</key>
     <array>
         <string>$prog</string>
-        <string>start</string>
+        <string>update</string>
         <string>$iface</string>
     </array>
-
 </dict>
 </plist>
 EOF2
 
-    $e cp $0 $prog
+    test -d $Bindir || $e mkdir -p $Bindir
+    $e cp $PROG $prog
     $e chmod a+rx,og-w $prog
 
+    $e launchctl load $file
+    $e launchctl enable system/$fname
+
     echo "Installed to $file and $prog .."
 
     return 0
 }
 
+# -- start of main() --
 
 iface=$1
 if [ -z "$iface" ]; then
     iface=`wait_wifi_darwin`
-
-    if [ -z "$iface" ]; then
-      echo "$Z: Can't figure out the WiFi interface. Aborting..." 1>&2
-      exit 1
-    fi
+    test -n "$iface" || die "Can't figure out the WiFi interface. Aborting..."
 else
     verify_wifi_Darwin $iface
-    if [ $? -ne 0 ]; then
-        exit 1
-    fi
+    test $? -eq 0 || exit 1
 fi
-FNAME=${FNAME}.$iface
 
-$e ifconfig $iface down
 
 case $action in
     start|update)
-        #echo "Setting MAC Address for $iface .."
+        if [ $Me -ne 0 ]; then
+            die "Need root privileges to set/update MAC address"
+        fi
+
+        $e ifconfig $iface down
         update_mac $iface
         ;;
 
     install)
-        install_service
+        install_service ${iface} ${FNAME}
         ;;
 
     stop|restart)