PPPoE, ppp over ethernet script, mostly for bridged mode adsl connections

 * Manage configuration and authentication files
 * start/stop connection
 * get status
 * get DNS list provided by the peer (though peer overwrites resolv.conf)

 It should be working, though not tested enough for error cases yet

betikler/pppoe.py

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import popen2
+import os
+
+class pppoe:
+	""" Functions to configure and run PPP over Ethernet connections  """
+
+	tmpl_pppoe_conf = """
+#***********************************************************************
+#
+# /etc/ppp/pppoe.conf
+#
+# Configuration file for rp-pppoe.
+#
+# NOTE: This file is used by the adsl-start, adsl-stop, adsl-connect and
+#       adsl-status shell scripts.  It is *not* used in any way by the
+#       "pppoe" executable.
+#
+#***********************************************************************
+
+# When you configure a variable, DO NOT leave spaces around the "=" sign.
+
+# Ethernet card connected to ADSL modem
+#
+# NB: Gentoo overrides ETH when adsl-start is called from the
+# networking scripts.  This setting has no effect in that case.
+ETH=\"%s\"
+
+# ADSL user name.  You may have to supply "@provider.com"  Sympatico
+# users in Canada do need to include "@sympatico.ca"
+# Sympatico uses PAP authentication.  Make sure /etc/ppp/pap-secrets
+# contains the right username/password combination.
+# For Magma, use xxyyzz@magma.ca
+USER=\"%s\"
+
+# Bring link up on demand?  Default is to leave link up all the time.
+# If you want the link to come up on demand, set DEMAND to a number indicating
+# the idle time after which the link is brought down.
+DEMAND=no
+#DEMAND=300
+
+# DNS type: SERVER=obtain from server; SPECIFY=use DNS1 and DNS2;
+# NOCHANGE=do not adjust.
+DNSTYPE=SERVER
+
+# Obtain DNS server addresses from the peer (recent versions of pppd only)
+# In old config files, this used to be called USEPEERDNS.  Changed to
+# PEERDNS for better Red Hat compatibility
+PEERDNS=yes
+
+DNS1=
+DNS2=
+
+# Make the PPPoE connection your default route.  Set to
+# DEFAULTROUTE=no if you don't want this.
+DEFAULTROUTE=yes
+
+### ONLY TOUCH THE FOLLOWING SETTINGS IF YOU'RE AN EXPERT
+
+# How long adsl-start waits for a new PPP interface to appear before
+# concluding something went wrong.  If you use 0, then adsl-start
+# exits immediately with a successful status and does not wait for the
+# link to come up.  Time is in seconds.
+#
+# WARNING WARNING WARNING:
+#
+# If you are using rp-pppoe on a physically-inaccessible host, set
+# CONNECT_TIMEOUT to 0.  This makes SURE that the machine keeps trying
+# to connect forever after adsl-start is called.  Otherwise, it will
+# give out after CONNECT_TIMEOUT seconds and will not attempt to
+# connect again, making it impossible to reach.
+CONNECT_TIMEOUT=30
+
+# How often in seconds adsl-start polls to check if link is up
+CONNECT_POLL=2
+
+# Specific desired AC Name
+ACNAME=
+
+# Specific desired service name
+SERVICENAME=
+
+# Character to echo at each poll.  Use PING="" if you don't want
+# anything echoed
+PING="."
+
+# File where the adsl-connect script writes its process-ID.
+# Three files are actually used:
+#   $PIDFILE       contains PID of adsl-connect script
+#   $PIDFILE.pppoe contains PID of pppoe process
+#   $PIDFILE.pppd  contains PID of pppd process
+#
+# NB: Gentoo overrides PIDFILE when adsl-start is run from the
+# networking scripts.  This setting has no effect in that case.
+# PIDFILE="/var/run/$CF_BASE-adsl.pid"
+PIDFILE="/var/run/adsl.pid"
+
+# Do you want to use synchronous PPP?  "yes" or "no".  "yes" is much
+# easier on CPU usage, but may not work for you.  It is safer to use
+# "no", but you may want to experiment with "yes".  "yes" is generally
+# safe on Linux machines with the n_hdlc line discipline; unsafe on others.
+SYNCHRONOUS=no
+
+# Do you want to clamp the MSS?  Here's how to decide:
+# - If you have only a SINGLE computer connected to the ADSL modem, choose
+#   "no".
+# - If you have a computer acting as a gateway for a LAN, choose "1412".
+#   The setting of 1412 is safe for either setup, but uses slightly more
+#   CPU power.
+CLAMPMSS=1412
+#CLAMPMSS=no
+
+# LCP echo interval and failure count.
+LCP_INTERVAL=20
+LCP_FAILURE=3
+
+# PPPOE_TIMEOUT should be about 4*LCP_INTERVAL
+PPPOE_TIMEOUT=80
+
+# Firewalling: One of NONE, STANDALONE or MASQUERADE
+FIREWALL=NONE
+
+# Linux kernel-mode plugin for pppd.  If you want to try the kernel-mode
+# plugin, use LINUX_PLUGIN=rp-pppoe.so
+LINUX_PLUGIN=
+
+# Any extra arguments to pass to pppoe.  Normally, use a blank string
+# like this:
+PPPOE_EXTRA=""
+
+# Rumour has it that "Citizen's Communications" with a 3Com
+# HomeConnect ADSL Modem DualLink requires these extra options:
+# PPPOE_EXTRA="-f 3c12:3c13 -S ISP"
+
+# Any extra arguments to pass to pppd.  Normally, use a blank string
+# like this:
+PPPD_EXTRA=""
+
+
+########## DON'T CHANGE BELOW UNLESS YOU KNOW WHAT YOU ARE DOING
+# If you wish to COMPLETELY overrride the pppd invocation:
+# Example:
+# OVERRIDE_PPPD_COMMAND="pppd call dsl"
+
+# If you want adsl-connect to exit when connection drops:
+# RETRY_ON_FAILURE=no
+"""
+	
+	tmpl_options = """
+noipdefault
+hide-password
+defaultroute
+persist
+lock
+"""
+
+	def silentUnlink(self, path):
+		""" Try to unlink a file, if exists """
+
+		try:
+			os.unlink(path)
+		except:
+			pass
+
+	def capture(self, cmd):
+		""" Run a command and capture the output """
+
+		out = []
+		a = popen2.Popen4(cmd)
+		while 1:
+			b = a.fromchild.readline()
+			if b == None or b == "":
+				break
+			out.append(b)
+		return (a.wait(), out)
+
+	def getDNS(self):
+		""" Try to get DNS server adress provided by remote peer """
+
+		list = []
+		try:
+		    f = file("/etc/ppp/resolv.conf", "r")
+		    for line in f.readlines():
+		        if line.strip().startswith("nameserver"):
+		            list.append(line[line.find("nameserver") + 10:].rstrip('\n').strip())
+		    f.close()
+		except IOError:
+		    return None
+
+		return list
+
+	def createConf(self, dev, user):
+		""" Create configuration file for pppoe connections """
+
+		self.silentUnlink("/etc/ppp/pppoe.conf")
+		try:
+			f = open("/etc/ppp/pppoe.conf", "w")
+			f.write(self.tmpl_pppoe_conf % (dev, user))
+			f.close()
+		except:
+			return True
+
+		return None
+
+	def createOptions(self):
+		""" Create options file for pppoe connections """
+
+		self.silentUnlink("/etc/ppp/options-pppoe")
+		try:
+			f = open("/etc/ppp/options-pppoe", "w")
+			f.write(self.tmpl_options)
+			f.close()
+		except:
+			return True
+
+		return None
+
+	def createSecrets(self, user, pwd):
+		""" Create authentication files """
+
+		try:
+			# Ugly way to clean up secrets and recreate
+			self.silentUnlink("/etc/ppp/pap-secrets")
+			self.silentUnlink("/etc/ppp/chap-secrets")
+			f = os.open("/etc/ppp/pap-secrets", os.O_CREAT, 0600)
+			os.close(f)
+			os.symlink("/etc/ppp/pap-secrets", "/etc/ppp/chap-secrets")
+		except:
+			return True
+			
+		f = open("/etc/ppp/pap-secrets", "w")
+		data = "\"%s\" * \"%s\"\n" % (user, pwd)
+		f.write(data)
+		f.close()
+
+		return None
+
+	def getStatus(self):
+		""" Stop the pppoe connection """
+
+		cmd = "/usr/sbin/adsl-status"
+		i, output = self.capture(cmd)
+
+		return output
+
+	def stopPPPD(self):
+		""" Stop the pppoe connection """
+
+		cmd = "/usr/sbin/adsl-stop"
+		i, output = self.capture(cmd)
+
+		return output
+
+	def startPPPD(self):
+		""" Start the PPP daemon """
+
+		cmd = "/usr/sbin/adsl-start"
+		i, output = self.capture(cmd)
+
+		return output
+
+	def connect(self, dev, user, pwd):
+		""" Try to start a pppoe connection through dev and login """
+	
+		if self.createConf(dev, user) is True:
+			return "Could not manage pppoe configuration"
+
+		if self.createOptions() is True:
+			return "Could not manage pppd parameters"
+
+		if self.createSecrets(user, pwd) is True:
+			return "Could not manage authentication files"
+
+		output = self.startPPPD()
+		return output
+
+if __name__ == "__main__":
+	rp = pppoe()
+	rp.connect("eth0", "parbusman@uludag", "pek gizli")
+