#############################################################
# Document: ppp-vpn-howto
# Purpose : Document how I made a VPN work with Slackware
# Author..: Stuart Winter <stuart@polplex.co.uk>
# Date....: May-2004
# Version : 1.0
#############################################################
# Reference URLs
#  Kernel patches: http://www.polbox.com/h/hs001/
#  pptpd source:   http://www.poptop.org
#  http://poptop.sourceforge.net/dox/source-howto.html
#############################################################

1. Download & extract Linux Kernel source
   --------------------------------------

   Do the usual thing here.

2. Download kernel patches:
   ------------------------

   No longer required in Linux 2.6.20.

3. Set Kernel options:
   -------------------

   # make menuconfig
   Network device support
     * PPP (point-to-point protocol) support
     * Microsoft PPP compression/encryption (MPPC/MPPE)
   ( I compiled them all as modules - compile all PPP stuff as modules too)
   
   Under root menu:
   Cryptographic options
   -> SHA1 and RC4 algorithms in CryptoAPI's configuration menu,
   * These are included by default when you select the MPPE PPP modules *

4. Compile & install Kernel:
   -------------------------

   # make dep && make clean && make bzImage && make modules && make modules_install
   # mv -f System.map /boot
   # mv -f arch/i386/boot/bzImage /boot/vmlinuz
   # lilo
   # reboot

5. Download PPPd & the patch:
   --------------------------

   If you really want to you can grab the n/ppp source directory from Slackware,
   add the patch line into the build script, run ppp.SlackBuild and re-build
   the ppp package.

   # ( cd /usr/src
       # grab slackware-current/source/n/ppp 
       cd ppp
 #      wget http://mppe-mppc.alphacron.de/ppp-2.4.3-mppe-mppc-1.1.patch.gz
#http://bugs.lunar-linux.org/view.php?id=129
       wget http://www.nikhef.nl/~janjust/ppp/ppp-2.4.4-eaptls-mppe-0.9no_ifdefs.patch
       patch -p1 < $CWD/ppp-2.4.4-eaptls-mppe-0.9no_ifdefs.patch
       ./configure && make && make install )

6. Add module to /etc/modules.conf:
   --------------------------------

   cat << EOF >> /etc/modprobe.conf
alias char-major-108 ppp_generic
alias tty-ldisc-3 ppp_async 
alias tty-ldisc-14 ppp_synctty 
#alias ppp-compress-18 ppp_mppe
alias ppp-compress-18 ppp_mppe_mppc
alias ppp-compress-21 bsd_comp
alias ppp-compress-24 ppp_deflate
alias ppp-compress-26 ppp_deflate
alias net-pf-47 ip_gre
EOF
   # depmod -va

7. Download & build poptop (pptpd):
   --------------------------------

   # ( cd /usr/src/vpn
       wget http://puzzle.dl.sourceforge.net/sourceforge/poptop/pptpd-1.3.2.tar.gz
       tar zxf pptpd-1.3.2.tar.gz
       cd pptpd-*
       ./configure --prefix=/usr --sysconfdir=/etc
       mkdir -p /tmp/package-pptpd
       make -j3 && make install DESTDIR=/tmp/package-pptpd )   

8. Install config files:
   ---------------------

   # ( cd /usr/src/vpn
       mkdir pppconfig
       cd pppconfig
       wget http://poptop.sourceforge.net/dox/modules.conf.txt
       wget http://poptop.sourceforge.net/dox/pptpd.conf.txt
       wget http://poptop.sourceforge.net/dox/options.pptpd.txt
       wget http://poptop.sourceforge.net/dox/chap-secrets.txt
       mv -f pptpd.conf.txt    /etc/pptpd.conf
       mv -f options.pptpd.txt /etc/ppp/options.pptpd
       mv -f chap-secrets.txt /etc/ppp/chap-secrets
      ) 

9.  Modify config files:
    --------------------

    edit /etc/pptpd.conf
    [a] Change local IP from 192.168.0.1 to the LOCAL IP OF YOUR MACHINE
        (ie vpntest's IP is 10.0.50.250)
    [b] Change the IP range

    9.1 Update options.pptpd file:
        --------------------------

Put in your own DNS server at the bottom of this file:

cat << EOF > /etc/ppp/options.pptpd
name vpn
mtu 1450
mru 1450
proxyarp
auth
ipcp-accept-local
ipcp-accept-remote
lcp-echo-failure 3
lcp-echo-interval 5
mppe required,stateless
ms-dns 217.10.128.130
EOF

    9.2 Blank /etc/ppp/options:
        -----------------------

        # echo > /etc/ppp/options


    9.3 Create chap-secrets file:
        -------------------------

echo "myvpn          vpn     passwordfoo         *" > /etc/ppp/chap-secrets


10. Make pptpd start:
    ---------------- 

# cat << EOF >> /etc/rc.d/rc.local
/usr/sbin/pptpd -d
EOF


11.  Ensure pptp is allowed through the firewall
     --------------------------------------------

# Allow VPN
iptables -A INPUT -p tcp --dport pptp -j ACCEPT