Make Your Laptop Settings Roam with Laptop-net

Kyle Rankin

Quinstreet Inc.

Author of Knoppix Hacks, Knoppix Pocket Reference, Linux Multimedia Hacks, and Ubuntu Hacks

The Problem

• Laptops becoming more powerful
• Laptop commonly primary computer
• The Network is everywhere!
• but...
• Your settings are often network-specific:
• Network printer
• Hosts file
• Firewall
• Browser/Email
• Etc.

A Solution: Laptop-net

Laptop-net allows you to:

• Use settings on a per-network basis:
• Default printer
• /etc/hosts
• NFS/SMB mount points
• Firewall
• Browser (proxy vs. no proxy)
• Email + MTA settings
• Run scripts on a per-network basis:
• Automatically sync/backup files
• Set up tunnels/proxies
• Mount/umount network filesystems
• Change desktop background :)
• Pretty much anything

How Laptop-net Works

• Activates after you get an IP
• Compares the IP with pre-configured IP patterns for a match
• Copies config files for the matching profile to system
• Executes a script in the matching profile

Install Laptop-net

• Debian-based distributions only
• Install Laptop-net package
  # apt-get install laptop-net laptop-net-doc
• Reconfigure laptop-net to disable MII (especially for NetworkManager):
  # dpkg-reconfigure laptop-net
• Use DHCP
• Don't use MII (even if supported)
• Restart laptop-net:
  # /etc/init.d/laptop-net restart

Write DHCP Script

Use DHCP script to automatically launch laptop-net when getting/releasing a lease

• Create a file named /etc/dhcp3/dhclient-exit-hooks.d/laptop-net:

if [ $reason = 'BOUND' ]; then
   /usr/share/laptop-net/profile-change $interface
fi
if [ $reason = 'RELEASE' ]; then
   /usr/share/laptop-net/profile-change $interface down
fi

Fix Possible Bug

If /var/run/laptop-net isn't being created:

• Edit /etc/init.d/laptop-net and change:
  

  case "${1}" in
      ("start")
          [ $# -eq 1 ] || usage
  	clean_state
  	start_ifd
  	;;
  

• to:
  

  case "${1}" in
      ("start")
          [ $# -eq 1 ] || usage
  	mkdir -p /var/run/laptop-net
  	clean_state
  	start_ifd
  	;;
  

Configure laptop-net Profiles

Profiles have a few important files/directories:

• patterns
• files.d/
• after-select
• before-deselect

Configure laptop-net Profiles

Offline Profile

• # mkdir /etc/laptop-net/profiles/offline
• # cd /etc/laptop-net/profiles/offline
• Create a file in this dir called patterns:
  

  down
  unknown
  

• Create files.d dir to contain config file defaults
• Create after-select file and make it executable:
  

  #!/bin/sh
  echo "offline" > /tmp/laptop-net-state
  

Configure laptop-net Profiles

Default Network Profile

• # mkdir /etc/laptop-net/profiles/zzz-default
• # cd /etc/laptop-net/profiles/zzz-default
• Create a file in this dir called patterns:
  

  *.*.*.*
  

• Create files.d dir to contain default network config files
• Create after-select file and make it executable:
  

  #!/bin/sh
  echo "zzz-default" > /tmp/laptop-net-state
  

• Option: add restrictive firewall to after-select

Configure laptop-net Profiles

Test Your Profiles

• Deactivate network connection and cat /tmp/laptop-net-state (should say "offline")
• Activate network connection and cat /tmp/laptop-net-state (should say "zzz-default")
• Monitor laptop-net in /var/log/syslog:

Mar  4 16:12:56 ubuntu laptop-net: Selecting network profile "zzz-default"
Mar  4 15:19:42 ubuntu laptop-net: Deselecting network profile "zzz-default"
Mar  4 15:19:42 ubuntu laptop-net: Selecting network profile "offline"
Mar  4 15:24:06 ubuntu laptop-net: Deselecting network profile "offline"
Mar  4 15:24:07 ubuntu laptop-net: Selecting network profile "zzz-default"

Configure laptop-net Profiles

Home Profile

• # cd /etc/laptop-net/profiles/
• # cp -a zzz-default home
• Create the home profile patterns file:
  

  192.168.0.*
  

• Create files.d dir to contain config files for each profile
• Create after-select file and make it executable:
  

  #!/bin/sh
  echo "home" > /tmp/laptop-net-state
  

Configure laptop-net Profiles

Work Profile

• # cd /etc/laptop-net/profiles/
• # cp -a zzz-default work
• Create the work profile patterns file:
  

  10.1.1.50
  10.1.1.100
  

• Create files.d dir to contain config files for each profile
• Create after-select file and make it executable:
  

  #!/bin/sh
  echo "work" > /tmp/laptop-net-state
  

Make Your Default Printer Roam

1. Configure printer settings and set the default printer for a profile
2. copy /etc/cups/printers.conf to /etc/laptop-net/profiles/profilename/files.d/etc/cups/printers.conf
3. Edit after-select script for the profile and add:
   /etc/init.d/cupsys restart
4. Copy above steps for any other profiles you want to have a default printer

Questions?