#!/bin/bash

#####################################################################
## Purpose
# This file is executed by ifupdown in pre-up and post-down phases of
# network interface configuration. It allows ifup(8), and ifdown(8) to
# manage interfaces on WWAN cards like Ericsson F3507g
#####################################################################

# Copyright (C) 2009,2011 Bjørn Mork <bjorn@mork.no>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# On Debian GNU/Linux systems, the text of the GPL license can be
# found in /usr/share/common-licenses/GPL.


# Most of the commands in this script are documented in 
# Sony Ericsson Doc. No. 1206-6103.8 titled 
# "AT commands for Sony Ericsson phones"
# available for download from http://www.sonyericsson.com/developer


##FIXME:  should use AT&F to have control of the reported error messages
##FIXME:  maybe use AT+CMEE=1 and get more specific error codes?
##  example:
##    AT*E2NAP=1
##    +CME ERROR: 263
##    AT&F
##    OK
##    AT*E2NAP=1
##    ERROR
##   note the need to identify "+CME ERROR: *" as "ERROR"


## This one is also interesting:
## AT+CEER
## +CEER: Detach Cause: GMM10 (Implicitly detached)
## 
## OK

## Defaults which can be changed globally in /etc/default/wwan_ctl
## or locally per interface in /etc/network/interfaces

## List of supported VID:PID values
SUPPORTED="0bdb:1900"

## Timeout for the read commands
TMOUT=10

## Access Point Name
## Documented by Ericsson as
##<APN>: Access Point Name – a string parameter which is a logical name, used to
##       select the GGSN or the external packet data network.
##       If the value is null or omitted, then the subscription value will be requested.
##
## Note that this can be overriden on a per-interface basis by setting wwan_apn
## in /etc/network/interfaces
WWAN_APN="" 

## Whether to power off radio when interface goes down
## Note:  Do not set this if you use the GPS
WWAN_POWEROFF=1

## Maunally overriding GPS port
WWAN_GPSTTY=""

## Radio mode 1=auto, 5=GSM, 6=UTRAN
WWAN_MODE=1

## Disallow roaming by default
WWAN_ROAMING_OK=0

### for script testing:
WWAN_DEBUG=0


# source a configuration file to allow some settings, like e.g SIM PIN
# code or APN, to be configured in a common place
if [ -r /etc/default/wwan_ctl ]; then
    . /etc/default/wwan_ctl
fi

if [ $WWAN_DEBUG -ge 2 ]; then
    set -x
fi


wwan_checkdevice () {
    ## FIXME: Is readlink available?  There's an implementation in
    ## /etc/init.d/ifupdown if not...

    # get the usb device and vid:pid
    if [ -n "$IFACE" ]; then
	XCLASSDEV="/class/net/$IFACE"
    else 
	if [ -n "$WWAN_GPSTTY" ]; then
	    XCLASSDEV="/class/tty/$WWAN_GPSTTY"
	else
	    return 1
	fi
    fi
    USBDEV=`readlink -f /sys$XCLASSDEV/device/..`
    if [ -f "$USBDEV/idVendor" -a -f "$USBDEV/idProduct" ]; then
	VP=`cat $USBDEV/idVendor`:`cat $USBDEV/idProduct`
    else
    # just ignore any non-USB device
	return 1
    fi

    # check if the device is known to be supported
    for x in "$SUPPORTED"; do
	[ "$VP" = "$x" ] && return 0
    done

    # unsupported card - consider setting SUPPORTED in /etc/default/wwan_ctl 
    return 1
}

## search for the GPS port by simply grepping for it and testing with wwan_checkdevice()
wwan_getgpsport () {
    # try the configured value first, if any
    [ -n "$WWAN_GPSTTY" ] && wwan_checkdevice && return 0
    for f in `grep -l GPS /sys/class/{tty/*,tty:*}/device/interface 2>/dev/null`; do
	WWAN_GPSTTY=`dirname \`dirname $f\`|sed -e 's/.*[:/]//'`
	wwan_checkdevice && return 0
    done
    # no GPS port found
    WWAN_GPSTTY=""
    return 1
}

wwan_getmgmt () {

    # get the list of possible managment devices:
    #
    # We implement standard(?) serial port locking
    remove_lock () {
	rm $LOCK
    }

    # We have a lockup problem with cdc-wdm devices in Linux 3.0
    ver=`uname -r`
    if [ ${ver%%-*} \> "2.6.32" ]; then
	echo "Enabling workaround for cdc-wdm problems in Linux $ver"
        devs="$USBDEV/*/tty/*" 
    else
        devs="$USBDEV/*/usb/* $USBDEV/*/usb:* $USBDEV/*/tty/* $USBDEV/*/tty:*" 
    fi

echo DEBUG: devs=\"$devs\"

    for d in $devs; do if [ -e $d ]; then 
	dev=`basename $d | sed -e 's/.*://'`
	echo "trying $dev"
	LOCK="/var/lock/LCK..$dev"
	if [ ! -e $LOCK ]; then
	    touch $LOCK
	    MGMT="/dev/$dev"
	    trap remove_lock EXIT
	    break
	else
	    echo "Device /dev/$dev is locked."
	fi
    fi; done
    desc=${IFACE:-GPS}
    if [ -z "$MGMT" ]; then
	echo "Cannot locate a management device for $desc"
	exit 1
    fi

    # setting mode may fix things a bit - these settings come from pppd...
    # NOTE: this fails with "Inappropriate ioctl for device" on cdc-wdm device
    #       as expected.  Ignore that.
    stty min 1 time 0 \
	-parenb -parodd cs8 -hupcl -cstopb cread clocal -crtscts \
	ignbrk -brkint ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany -imaxbel -iutf8 \
	-opost -olcuc -ocrnl -onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 \
	-isig -icanon -iexten -echo -echoe -echok -echonl -noflsh -xcase -tostop -echoprt -echoctl -echoke \
	115200 -F $MGMT   2>/dev/null

    echo "Selected $MGMT for management of $desc"

}


##
wwan_verify_pin () {
    # wait for card to get ready with short timeout
    local TMOUT=1
    while read x; do
	case "$x" in
	    \*EMRDY:*)
		if [ "${x#\*EMRDY: }" != "1" ]; then
		    echo "Unknown state: $x"
		else
		    echo "Card is ready for commands"
		fi
		;;
	    *)
		;;
	esac
    done <$MGMT
    
    local TMOUT=5
    pinsent="xxxx"
    echo -e "AT+CPIN?\r" >$MGMT
    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
            +CPIN:*)
		status=${x#+CPIN: }
		;;
            OK)
		case "$status" in
                    READY)
			return 0
			;;
                    SIM\ PIN)
			if [ "$pinsent" == "$WWAN_PIN" ]; then
			    echo "Refusing to enter the same PIN code twice!"
			    status="pinsent"
			else if [ -n "$WWAN_PIN" ]; then
                            echo -e "AT+CPIN=\"$WWAN_PIN\"\r" >$MGMT
			    status="pinsent"
			    pinsent=$WWAN_PIN
			    # give the card a chance to process the PIN before continuing...
			    sleep 1
			else
                            echo "SIM PIN code requested, but none configured"
			    return 3
			fi; fi
			;;
		    pinsent)
			echo -e "AT+CPIN?\r" >$MGMT
			;;
		    PH-SIM\ PIN)
			# FIMXE: What is this?  It's reported if
			# requesting AT+CPIN? immediately after
			# entering the PIN CODE
			# sleep and retry (global timeout applies)
			sleep 1
			echo -e "AT+CPIN?\r" >$MGMT
			;;
		    *)
                        # don't get by leftover OKs...
			if [ -n "$status" ]; then
			    echo "Card requested \"$status\" - bailing out"
			    return 4
			fi
			;;
		esac
		;;
            ERROR)
		if [ "$status" = "pinsent" ]; then
		    echo "Yay! I might use the wrong pincode - please fix before SIM is locked"
		else
		    echo "Card did not accept \"AT+CPIN?\" command - bailing out"
		fi
		return 1
		;;
            *)
	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}


wwan_enable_gps () {
    [ -n "$WWAN_GPSTTY" ] || return 3

    # get sane tty settings from pppd(!)
    stty min 1 time 0 \
	-parenb -parodd cs8 -hupcl -cstopb cread clocal -crtscts \
	ignbrk -brkint ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany -imaxbel -iutf8 \
	-opost -olcuc -ocrnl -onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 \
	-isig -icanon -iexten -echo -echoe -echok -echonl -noflsh -xcase -tostop -echoprt -echoctl -echoke \
	115200 -F /dev/$WWAN_GPSTTY

    echo -e "AT*E2GPSCTL=1,3,1\r" >$MGMT
    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
            OK)
		echo "Enabling GPS output on /dev/$WWAN_GPSTTY"
		echo -e "AT*E2GPSNPD\r" >/dev/$WWAN_GPSTTY
		 /lib/udev/gpsd.hotplug add /dev/$WWAN_GPSTTY
		#gpsd /dev/$WWAN_GPSTTY
		return 0
		;;
	    \+PACSP0)
		# probably means that our first attempt to connect was too early - retry
		echo -e "AT*E2GPSCTL=1,3,1\r" >$MGMT
		err_is_fatal=1  # flag next error as fatal
		;;
            ERROR)
	        if [ -n "$err_is_fatal" ]; then
		    return 1
		fi
		;;
            *)
   	        # silently ignore echoed command etc
		;;
	esac
	
    done <$MGMT
    return 2 # timeout
}

# Better just check whether we're already connected before continuing
wwan_connected () {
    echo -e "AT*ENAP?\r" >$MGMT
    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
	    \*ENAP:*)
		ENAP=${x#\*ENAP: }
		;;
            OK)
		if [ "$ENAP" = "1" ]; then
		    return 0
		else
		    return 1
		fi
		;;
            ERROR)
	        # this is expected at this point if the radio is powered down
                # => ignore silently
		return 1 # not connected
		;;
            *)
   	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}

# wwan_configure_account() will try to make smart account choices:
#  if APN is unset, then it will choose the first available account
#  or create a new with APN="" if no accounts were defined
#  if APN is set to something, then it will try to locate an
#  existing account with the same APN, or create a new account in
#  an empty slot


wwan_configure_account () {
## FIXME:  Support choosing specific account numbers
## FIXME:  Support multiple accounts for the same APN
## FIXME:  Take into account that we might have holes
##           in the account numbering

    ## use interface specific APN if specified
    WWAN_APN=${IF_WWAN_APN:-$WWAN_APN}

    HIGHEST_NUM=0
    echo -e "AT+CGDCONT?\r" >$MGMT
    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
	    
            +CGDCONT:*)
		oldifs=$IFS
		IFS=","
		tmp=(${x#+CGDCONT: })
		IFS=$oldifs
		if [ -z "$ACCOUNT_NUM" -a "\"$WWAN_APN\"" = "${tmp[2]}" ]; then
		    # found a matching account => use it
		    ACCOUNT_NUM=${tmp[0]}
		fi
		# keep track of accounts in use
		HIGHEST_NUM=${tmp[0]}
		;;
            OK)
		if [ -z "$ACCOUNT_NUM" ]; then
		    # create a new one
		    ACCOUNT_NUM=$((HIGHEST_NUM+1))
		    echo "Creating new account number $ACCOUNT_NUM for \"$WWAN_APN\""
		    echo -e "AT+CGDCONT=$ACCOUNT_NUM,\"IP\",\"$WWAN_APN\"\r" >$MGMT
		else
		    return 0
		fi
		;;
            ERROR)
		echo "Failed to create an account"
		return 1
		;;
            *)
	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}


wwan_power_radio_on () {
#  4) power on radio: 
#    AT+CFUN=1


##FIXME: The mode testing below should ensure that the radio is in the
##user selected mode

    # poll once in case the card was powered on
    # turn on power status reporting, making further polls unecessary
    # also turning on network reg status
    echo -e "AT+CFUN?;*E2CFUN=1;+CGREG=2\r" >$MGMT

    # be careful not to send new commands before getting the OK from the last one...
    nextcmd=""

    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
	    \*E2CFUN:*)   # "*E2CFUN: 1,4,0" means power status = 4 
		oldifs=$IFS
		IFS=","
		tmp=(${x#\*E2CFUN: })
		IFS=$oldifs
		case "${tmp[1]}" in
		    "1") 
			echo "Powered on (auto mode)"
			# dont. wait until registered
			# return 0
			;;
		    "4")
			echo "Radio is off"
			;;
		    "5")
			echo "Powered on (GSM only mode)"
			# dont. wait until registered
			# return 0
			;;
		    "6")
			echo "Powered on (UTRAN only mode)"
			# dont. wait until registered
			# return 0
			;;
		    *)
			echo "Unknown status report: \"$x\""
			;;
		esac
		;;

	    ## NOTE: The format of the unsolicited and solicited command differ
	    ## solicited:
	    ## AT+CGREG?
	    ## +CGREG: 2,1,"4EE9","00C9A2D6",2
	    ## OK
	    ##
	    ## unsolicited:

	    ## +CGREG: 0
	    ## +CGREG: 0
	    ## +CGREG: 4
	    ## *E2CFUN: 1,6,0
	    ## +CGREG: 4
	    ## +CGREG: 1,"4EE9","00C9A2D6",2

            +CGREG:*)
		oldifs=$IFS
		IFS=","
		tmp=(${x#+CGREG: })
		IFS=$oldifs

		# look at the second value if we got a 5 element result
		if [ ${#tmp[@]} -ge 5 ]; then
		    stat=${tmp[1]}
		else
		    stat=${tmp[0]}
		fi

		case "$stat" in
		    "0")
			# we get these while waiting, so maybe just silently ignore?
			echo "Not registered"
		     ;;
		    "1")
			##FIXME:  Look at CI to guess GSM (<=FFFF) or UTRAN (>FFFF)
			echo "Registered to home network"
			return 0
			;;
		    "2")
			echo "Searching for network..."
			;;
		    "3")
			echo "Network regstration denied - contact operator"
			;;
		    "4")
			## FIXME: Documented as Unknown, but obviously has some meaning
			echo "Registering..."
			;;
		    "5")
			##FIXME: Report which network/operator using AT+COPS?
			if [ "$WWAN_ROAMING_OK" = "1" ]; then
			    echo "Roaming.  Be aware that this can be expensive"
			    return 0
			else
			    echo "Roaming.  Denied by policy.  Please see documentation"
			    return 3
			fi
			;;
		    *) 
			echo "A rather unexpected +CGREG status code: ${tmp[0]}"
			return 3
		esac
		;;
            +CFUN:*)
		CFUN=${x#+CFUN: }
		case "$CFUN" in
		    "1"|"5"|"6") 
			nextcmd="AT+CGREG?"
			echo "Already on"
			##FIXME: verify network registration
			;;
		    "4")
			nextcmd="AT+CFUN=$WWAN_MODE"
			echo "Powering on radio"
			;;
		    *)
			echo "Unknown radio status: \"$x\""
			ret=3
			;;
		esac
		;;
            OK)
		if [ -n "$nextcmd" ]; then
		    echo -e "$nextcmd\r" >$MGMT
		    nextcmd=""
		fi
		# note: we don't return here, as the success will be flagged by a +CGREG: 1,... line
		;;
            ERROR)
		echo "Failed to power on radio"
		return 1
		;;
            *)
	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}



wwan_connect () {

## Well, it may fail else too.  We'd better be prepared, and should probably add
## better error reporting

##FIXME: Had an incident where the card had to be reset before I got this working
##   again.  AT*ENAP=1,x just gave ERROR although AT*ENAP=? succeeded


    # Note:  we may have to flush a few +CGREG: 1 lines first
    local TMOUT=1
    while read x; do
	case "$x" in
	    *)
		;;
	esac
    done <$MGMT

    # this needs higher timeout values....
    local TMOUT=30

    # turn on status reporting
    echo -e "AT*E2NAP=1;+CMEE=2\r" >$MGMT

    # repeat turning on status reporting as well, as that will fail too if not fully powered up
    nextcmd="AT*E2NAP=1;+CMEE=2;*ENAP=1,$ACCOUNT_NUM"

    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
	    \*E2NAP:*)
		case "${x#\*E2NAP: }" in
		    0)
			##FIXME:  This must be handled. It *does* happen
			echo "Not connected. Retrying..."
			sleep 2  # better make it wait a bit
			echo -e "AT*ENAP=1,$ACCOUNT_NUM\r" >$MGMT
			;;
		    1) 
			echo "Connected"
			return 0
			;;
		    2)
			echo "Connection in progress..."
			;;
		    *)
			echo "Unknown status: \"$x\""
			;;
		esac
		;;
	    \*ENAP:*)
		;;
	    OK|\+PACSP0)
		# +PACSP0 probably means that our first attempt to connect was too early - retry
		if [ -n "$nextcmd" ]; then
		    echo -e "$nextcmd\r" >$MGMT
		    nextcmd=""
		    err_is_fatal=1  # flag next error as fatal
		fi
		;;
	    ERROR|\+CME\ ERROR:*)
	        if [ -n "$err_is_fatal" ]; then
		    return 1
		fi
		;;
            *)
	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}




wwan_disconnect () {
## FIXME:  Should we power down radio here?  What if someone else is using
## the GPS or one of the ACM tty's (e.g. a SMS service daemon)?
## How do we know?
##
## Let's make it a configuration issue while we're thinkin

    # remove the GPS device from gpsd 
    if [ "$WWAN_POWEROFF" == "1" -a -n "$WWAN_GPSTTY" ]; then
	/lib/udev/gpsd.hotplug remove /dev/$WWAN_GPSTTY
    fi

    # Note:  we may have to flush a bit here
    local TMOUT=1
    while read x; do
	case "$x" in
	    *)
		;;
	esac
    done <$MGMT

    # the disconnect often takes some time
    local TMOUT=30
    if ! wwan_connected; then
	if [ "$WWAN_POWEROFF" == "1" ]; then
	    echo "Powering down radio"
	    echo -e "AT+CFUN=4;*E2CFUN=1\r" >$MGMT
	else
	    return 0
	fi
    else
        # go ahead disconnect
	echo -e "AT*ENAP=0;*E2NAP=1;*E2CFUN=1\r" >$MGMT
    fi


    while read x; do
        # strip \r's so we can use this for output
        # are there better ways to do multiline stripping? longest match doesn't
        # seem to catch on the \r's
	until [ "$x" = "$y" ]; do y=$x; x=${y%$'\r'}; done
	[ -n "$WWAN_DEBUG" ] && echo $x

	case "$x" in
	    \*E2NAP:*)
		E2NAP=${x#\*E2NAP: }
		case "$E2NAP" in
		    0)
			echo "Disconnected"
			if [ "$WWAN_POWEROFF" == "1" ]; then
			    echo "Powering down radio"
			    echo -e "AT+CFUN=4\r" >$MGMT
			else
			    return 0
			fi
			;;
		esac
		;;
	    \*E2CFUN:*)   # "*E2CFUN: 1,4,0" means power status = 4 
		oldifs=$IFS
		IFS=","
		tmp=(${x#\*E2CFUN: })
		IFS=$oldifs
		case "${tmp[1]}" in
		    "4")
			echo "Radio is off"
			return 0
			;;
		esac
		;;
	    OK)
		;;
            ERROR)
		return 1
		;;
            *)
	        # silently ignore echoed command etc
		;;
	esac
    done <$MGMT
    return 2 # timeout
}


do_start () {
     wwan_verify_pin || exit 1
     wwan_connected && exit 0
     wwan_configure_account || exit 1
     wwan_power_radio_on || exit 1
     wwan_connect || exit 1
}

do_stop () {
    wwan_verify_pin || exit 1
    wwan_disconnect || exit 1
    # wait to ensure status message resception before interface goes down
    sleep 2
}

do_gps () {
     wwan_verify_pin || exit 1
     wwan_connected
     wwan_power_radio_on || exit 1
     wwan_enable_gps || exit 1
}
    
wwan_getgpsport
wwan_checkdevice || exit 0
wwan_getmgmt || exit 0

case "$1" in
    gps)
	do_gps
	;;
    stop)
	do_stop
	;;
esac
	

case "$PHASE" in
    pre-up)
	do_start
        ;;
    post-down)
	do_stop
        ;;
esac

exit 0