====== OpenWRT ======

Linux distribution for embedded devices


===== Installation =====

search for your router model in:  http://wiki.openwrt.org to find specific instructions 


===== Config =====

==== Install LUCI web interface ====

  opkg update
  opkg install luci
  /etc/init.d/uhttpd enable
  /etc/init.d/uhttpd start

reach the webiface at http://router_IP/


==== Install Bash & setup .bashrc ====

  opkg update
  opkg install bash


edit **/etc/passwd** and replace **/bin/ash** for **/bin/bash** in the line starting with **root:**

  echo ". $HOME/.bashrc" > /root/.bash_profile


put your custom .bashrc in **/root/.bashrc**


==== SSH publickey authentication ====

you can do this in the webiface or manually:

copy your key from your desktop to the router's /tmp/ dir:

  scp ~/.ssh/id_rsa.pub root@<router IP>:/tmp

log in to the router and move the key:
  cat /tmp/id_rsa.pub >> /etc/dropbear/authorized_keys
  chmod 0600 authorized_keys


==== Reverse SSH publickey authentication - from router to desktop ====

a private key is autogenerated by dropbear in /etc/dropbear/dropbear_rsa_host_key 

extract id_rsa.pub public key on the router:
  dropbearkey -y -f /etc/dropbear/dropbear_rsa_host_key | grep ssh-rsa > /tmp/dropbear_rsa_host_key.pub

add the content of this file to '~/.ssh/authorized_keys' on the remote box

log in with
  ssh -i /etc/dropbear/dopbear_rsa_host_key user@remotebox


==== USB storage ====

**USB2.0 kernel module installation:**

http://wiki.openwrt.org/doc/howto/usb.essentials

  opkg update
  opkg install kmod-usb2
  insmod ehci-hcd


**package & filesystem modules installation:**

http://wiki.openwrt.org/doc/howto/usb.storage#required.packages

  opkg update
  opkg install kmod-usb-storage kmod-usb-storage-extras kmod-scsi-generic e2fsprogs kmod-fs-ext4 kmod-fs-vfat 
  opkg install block-mount block-extroot block-hotplug 


**format usb drive:**

FIXME testing ext4 options from https://blogofterje.wordpress.com/2012/01/14/optimizing-fs-on-sd-card/


"Ext4 with block size of 4k, without journaling, but with additional parameters to encourage Ext4 to do the right thing with respect to the erasure block:"

  mkfs.ext4 -O ^has_journal -E stride=2,stripe-width=1024 -b 4096 -L usbdata /dev/sdXY


**auto mount on boot:**

http://wiki.openwrt.org/doc/howto/usb.storage#configuration

block-mount and block-hotplug will take care of boot and automount. 

edit config in /etc/config/fstab - example with swap and data partition:

  config global automount
        option from_fstab 1
        option anon_mount 1
  
  config global autoswap
        option from_fstab 1
        option anon_swap 1
  
  config mount
        option target   /mnt/sd
        option device   /dev/sdc2
        option fstype   ext4
        option options  rw,sync,noatime,nodiratime
        option enabled  1
        option enabled_fsck 1
  
  config swap
        option device   /dev/sdc1
        option enabled  1