#!/bin/bash
# Copyright (c) 2004-2005 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# void pppd_depend(void)
#
# Sets up the dependancies for the module
pppd_depend() {
	after interface
	before dhcp
	provide ppp
}

# bool pppd_check_installed(void)
#
# Returns 1 if pppd is installed, otherwise 0
pppd_check_installed() {
	if [[ ! -x /usr/sbin/pppd ]]; then
		${1:-false} && eerror "For PPP support, emerge net-dialup/ppp"
		return 1
	fi
	return 0
}

# char *pppd_regex_escape(char *string)
#
# Returns the supplied string with any special regex
# characters escaped so they don't provide regex intructions
# This may be a candidate for adding to /sbin/functions.sh or
# net-scripts functions at some point
pppd_regex_escape() {
	local escaped_result="$*"
	escaped_result="${escaped_result//\\/\\\\}"
	escaped_result="${escaped_result//./\\.}"
	escaped_result="${escaped_result//+/\\+}"
	escaped_result="${escaped_result//(/\\(}"
	escaped_result="${escaped_result//)/\\)}"
	escaped_result="${escaped_result//[/\\[}"
	escaped_result="${escaped_result//]/\\]}"
	escaped_result="${escaped_result//\{/\\\{}"
	escaped_result="${escaped_result//\}/\\\}}"
	escaped_result="${escaped_result//\?/\\\?}"
	escaped_result="${escaped_result//\*/\\\*}"
	escaped_result="${escaped_result//\//\\/}" 
	escaped_result="${escaped_result//|/\\|}"
	escaped_result="${escaped_result//&/\\&}"
	escaped_result="${escaped_result//~/\\~}"
	escaped_result="${escaped_result//^/\\^}"
	escaped_result="${escaped_result//$/\\$}"
	echo "${escaped_result}"
}

# bool pppd_update_secrets_file(char* filepath, char* username, \
#    char* remotename, char* password)
#
# Add/update PAP/CHAP authentication information 
pppd_update_secrets_file() {
	local filepath="$1" username="$2" remotename="$3" password="$4"
	if [[ ! -f ${filepath} ]]; then
		touch ${filepath} && \
		chmod 0600 ${filepath} || \
		return 1
	fi

	#escape username and remotename, used in following sed calls
	local regex_username=$(pppd_regex_escape ${username})
	local regex_remotename=$(pppd_regex_escape ${remotename})
	local regex_password
	local regex_filter="[ \t]*\"?${regex_username}\"?[ \t]*\"?${regex_remotename}\"?[ \t]*"

	#read old password, including " chars 
	#for being able to distinct when we need to add or update auth info
	local old_password=$(
	sed -r -e "/^${regex_filter}\".*\"[ \t]*\$/\
		{s/^${regex_filter}(\".*\")[ \t]*\$/\1/;q;};\
		d;" \
		${filepath}
	)

	if [[ -z "${old_password}" ]]; then
		regex_username="${username//\\/\\\\}"
		regex_remotename="${remotename//\\/\\\\}"
		regex_password="${password//\\/\\\\}"
		regex_password=${password//"/\\\\"}
		sed -r -i -e "\$a\"${regex_username}\" ${regex_remotename} \"${regex_password}\"" ${filepath}
		vewarn "Authentication info has been added to ${filepath}"
	elif [[ "\"${password//\"/\\\"}\"" != "${old_password}" ]]; then
		regex_password="${password//\\/\\\\}"
		regex_password="${regex_password//\//\\/}"
		regex_password="${regex_password//&/\\&}"
		regex_password=${regex_password//\"/\\\\\"}
		sed -r -i -e "s/^(${regex_filter}\").*(\"[ \t]*)\$/\1${regex_password}\2/" ${filepath}
		vewarn "Authentication info has been updated in ${filepath}"
	fi
	return 0
}

# bool pppd_start(char *iface)
#
# Start PPP on an interface by calling pppd
#
# Returns 0 (true) when successful, otherwise 1
pppd_start() {
	${IN_BACKGROUND} && return 0

	local iface="$1" ifvar=$( bash_variable "$1" ) opts="" link
	if [[ ${iface%%[0-9]*} != "ppp" ]]; then
		eerror "PPP can only be invoked from net.ppp[0-9]"
		return 1
	fi

	local unit="${iface#ppp}"
	if [[ -z ${unit} ]] ; then
		eerror "PPP requires a unit - use net.ppp[0-9] instead of net.ppp"
		return 1
	fi

	# PPP requires a link to communicate over - normally a serial port
	# PPPoE communicates over Ethernet
	# PPPoA communicates over ATM
	# In all cases, the link needs to be available before we start PPP
	link="link_${ifvar}"
	if [[ -z ${!link} ]]; then
		eerror "${link} has not been set in /etc/conf.d/net"
		return 1
	fi

	# Might or might not be set in conf.d/net
	local user password i
	username="username_${ifvar}"
	password="password_${ifvar}"

	#Add/update info in PAP/CHAP secrets files
	if [[ -n ${!username} && -n ${!password} ]]; then
		for i in chap pap ; do
			if ! pppd_update_secrets_file "/etc/ppp/${i}-secrets" \
					"${!username}" "${iface}" "${!password}" ; then
				eerror "Failed to update /etc/ppp/${i}-secrets"
				return 1
			fi
		done
	fi

	# Load any commandline options
	opts="pppd_${ifvar}[@]"
	opts="${!opts}"

	# We don't work with these options set by the user
	for i in unit nodetach linkname maxfail persist ; do
		if [[ " ${opts} " == *" ${i} "* ]]; then
			eerror "The option \"${i}\" is not allowed"
			return 1
		fi
	done

	# Check for mtu/mru
	local mtu="mtu_${ifvar}"
	if [[ -n ${!mtu} ]]; then
		[[ " ${opts} " != *" mtu "* ]] && opts="${opts} mtu ${!mtu}"
		[[ " ${opts} " != *" mru "* ]] && opts="${opts} mru ${!mtu}"
	fi

	# Set linkname because we need /var/run/ppp-${linkname}.pid
	# This pidfile has the advantage of being there, even if ${iface} interface was never started
	opts="linkname ${iface} ${opts}"

	# Setup auth info
	[[ -n ${!username} ]] && opts="user '"${!username}"' ${opts}"
	opts="remotename ${iface} ${opts}"

	# Load a custom interface configuration file if it exists
	[[ -f "/etc/ppp/options.${iface}" ]] \
		&& opts="${opts} file /etc/ppp/options.${iface}"

	# Set forced options
	opts="unit ${unit} persist maxfail 0 ${opts}"

	# Setup connect script
	local chat="chat_${ifvar}[@]"
	if [[ -n "${!chat}" ]]; then
		opts="${opts} connect \"/usr/sbin/chat -e -E -v"

		local -a phone_number="phone_number_${ifvar}[@]"
		phone_number=( "${!phone_number}" )
		if [[ ${#phone_number[@]} -ge 1 ]]; then
			opts="${opts} -T '${phone_number[0]}'"
			if [[ ${#phone_number[@]} -ge 2 ]]; then
				opts="${opts} -U '${phone_number[1]}'"
			fi
		fi

		for i in "${!chat}"; do
			opts="${opts} '${i}'"
		done

		opts="${opts}\""
	fi

	# Add plugins
	local plugins="plugins_${ifvar}[@]"
	for i in "${!plugins}" ; do
		local -a plugin=( ${i} )
		# Bound to be some users who do this
		[[ ${plugin[0]} == "pppoe" ]] && plugin[0]="rp-pppoe"
		[[ ${plugin[0]} == "pppoa" ]] && plugin[0]="pppoatm"
		[[ ${plugin[0]} == "capi" ]] && plugin[0]="capiplugin"

		[[ ${plugin[0]} == "rp-pppoe" ]] && opts="${opts} connect true"
		opts="${opts} plugin ${plugin[0]}.so ${plugin[@]:1}"
		[[ ${plugin[0]} == "rp-pppoe" ]] && opts="${opts} ${!link}"
	done

	#Specialized stuff. Insert here actions particular to connection type (pppoe,pppoa,capi)
	local insert_link_in_opts=1
	if [[ " ${opts} " == *" plugin rp-pppoe.so "* ]]; then
		if [[ ! -e /proc/net/pppoe ]]; then
			# Load the PPPoE kernel module
			if ! modprobe pppoe ; then
				eerror "kernel does not support PPPoE"
				return 1
			fi
		fi

		# Ensure that the link exists and is up
		interface_exists "${!link}" true || return 1
		interface_up "${!link}"

		insert_link_in_opts=0
	fi

	if [[ " ${opts} " == *" plugin pppoatm.so "* ]]; then
		if [[ ! -d /proc/net/atm ]]; then
			# Load the PPPoA kernel module
			if ! modprobe pppoatm ; then
				eerror "kernel does not support PPPoATM"
				return 1
			fi
		fi
	fi
	[[ ${insert_link_in_opts} -eq 0 ]] || opts="${!link} ${opts}"

	ebegin "Running pppd"
	[[ " ${opts} " != *" updetach "* ]] && mark_service_inactive "net.${iface}"
	eval start-stop-daemon --start --exec /usr/sbin/pppd \
		--pidfile "/var/run/ppp-${iface}.pid" -- "${opts}" >/dev/null
	if [[ $? != "0" ]]; then
		eend $? "Failed to start PPP"
		mark_service_starting "net.${iface}"
		return $?
	fi

	if [[ " ${opts} " == *" updetach "* ]]; then
		local addr=$( interface_get_address "${iface}" )
		einfo "${iface} received address ${addr}"
	else
		einfo "Backgrounding ..."
		exit 0
	fi
	
	return 0
}

# bool pppd_stop(char *iface)
#
# Stop PPP link by killing the associated pppd process
#
# Returns 0 (true) if no process to kill or it terminates successfully,
# otherwise non-zero (false)
pppd_stop() {
	${IN_BACKGROUND} && return 0
	local iface="$1" pidfile="/var/run/ppp-$1.pid"

	[[ ! -s ${pidfile} ]] && return 0

	einfo "Stopping pppd on ${iface}"
	start-stop-daemon --stop --exec /usr/sbin/pppd --pidfile "${pidfile}"
	eend $?
}

# vim: ts=4