#!/bin/bash

# Copyright (C) 2007-2015 X2Go Project - http://wiki.x2go.org
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
#
# Copyright (C) 2007-2015 Oleksandr Shneyder <oleksandr.shneyder@obviously-nice.de>
# Copyright (C) 2007-2015 Heinz-Markus Graesing <heinz-m.graesing@obviously-nice.de>

# rnowotny, <rnowotny@rotek.at>
# patch for SSH_PORT, not to use the same SSH port on each Server, what
# is a problem if You want to connect to different servers at the same time with the windows client.
# the problem was reported already here :  https://www.mail-archive.com/x2go-user@lists.berlios.de/msg00547.html

# get my Ip Adress - also works on mac osx
get_my_ip() 		
	{
    local _ip _line
    while IFS=$': \t' read -a _line ;do
        [ -z "${_line%inet}" ] &&
           _ip=${_line[${#_line[1]}>4?1:2]} &&
           [ "${_ip#127.0.0.1}" ] && echo $_ip && return 0
      done< <(LANG=C /sbin/ifconfig)
	}
# /get my Ip Adress

# get random port 
get_random_port() 		
	{
	local n_random
	local n_port
	n_random=$RANDOM
	let "n_random %= 2200"
	n_port=$((30000 + $n_random*16))
	echo $n_port
	}
# /get random port 


b_randomize_ssh_port=0						# if You use hosts on a class C network, You should select "0" here.
											# each hosts SSH_PORT will be set to 30.000 + (128 x last octet of IP Adress)
											# this results in no collosions on a class C network with at least 128 ports for each host available for different sessions
											# if You select "1" here, the SSH_PORT will be set to 30.000 + random(0..2220 * 16)
											# the chance for a collision is n(Hosts) : 2220, with at least 16 ports for each host available for different sessions 		

if [ "$b_randomize_ssh_port" = "0" ]; then
	my_ip=$(get_my_ip)						# my IP Adress, for instance 192.168.0.105
	my_ip_last_octet="${my_ip##*.}"			# last octet of IP Adress, for instance 105
	SSH_PORT=$((30000+$my_ip_last_octet*128))  	# first ssh port = 30001 + last octet of IP Adress * 128 to avoid collisions on multiple windows clients
else
	SSH_PORT=$(get_random_port)
fi


X2GO_LIB_PATH="$(x2gopath libexec)";

$X2GO_LIB_PATH/x2gosyslog "$0" "info" "$(basename $0) called with options: $@"

X2GO_PORT=49 	#First port for X2GO=50
# patched out by rnowotny
# SSH_PORT=3000  	# first ssh port = 30001 + last octet of IP Adress to avoid collisions on multiple windows clients


# some sanity checks before session startup...
if egrep "^backend[ ]*=[ ]*postgres" /etc/x2go/x2gosql/sql 1>/dev/null 2>/dev/null && [ "x$USER" = "xroot" ]; then
	msg="The super-user \"root\" is not allowed to launch X2Go sessions."
	echo "$msg"
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "$msg"
	exit -1
elif [ -z "$USER" ]; then
	msg="The \$USER environment variable is not set. Aborting session startup."
	echo "$msg"
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "$msg"
	exit -2
elif [ -z "$HOME" ]; then
	msg="The \$HOME environment variable is not set. Aborting session startup."
	echo "$msg"
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "$msg"
	exit -4
elif ! echo $HOME | iconv -f ASCII -t ASCII 1>/dev/null 2>/dev/null; then
	msg="Your home directory path contains non-ASCII characters. Aborting session startup."
	echo "$msg"
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "$msg"
	exit -5
fi

X2GO_ROOT="${HOME}/.x2go"
export NX_ROOT=$X2GO_ROOT

X2GO_NXAGENT_DEFAULT_OPTIONS="-extension XFIXES -extension GLX -nolisten tcp"

if [ -r /etc/x2go/x2goagent.options ]; then
	source /etc/x2go/x2goagent.options
fi

if [ -z "$X2GO_NXAGENT_OPTIONS" ]; then
	X2GO_NXAGENT_OPTIONS="$X2GO_NXAGENT_DEFAULT_OPTIONS"
fi

REMOTE=localhost

# shadow sessions (via x2godesktopsharing) set the X2GO_CLIENT var in the process environment
# so either it is already set or we obtain it from SSH_CLIENT/SSH_CONNECTION
if [ -z "$X2GO_CLIENT" ] && [ -n "$SSH_CLIENT" ]; then
	X2GO_CLIENT=`echo $SSH_CLIENT | awk '{print $1}'`
elif [ -z "$X2GO_CLIENT" ] && [ -n "$SSH_CONNECTION" ]; then
	X2GO_CLIENT=`echo $SSH_CONNECTION | awk '{print $1}'`
fi
if [ -z "$X2GO_CLIENT" ]; then
	msg="The \$X2GO_CLIENT environment variable is not set. Possible reasons: \$SSH_CLIENT not set or \$SSH_CONNECTION not set. Or \$X2GO_CLIENT not set by ,,X2Go Desktop Sharing'' applet. Aborting session startup."
	echo "$msg"
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "$msg"
	exit -3
fi

$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "client announced itself as ,,$X2GO_CLIENT''"

X2GO_GEOMETRY="$1"; shift
X2GO_LINK="$1"; shift
X2GO_PACK="$1"; shift
X2GO_TYPE="$1"; shift
X2GO_KBD_LAYOUT="$1"; shift
X2GO_KBD_TYPE="$1"; shift
X2GO_SET_KBD="$1"; shift
X2GO_STYPE="$1"; shift
X2GO_CMD="$1"; shift
X2GO_RESIZE=1
X2GO_FULLSCREEN=0

X2GO_CLIPBOARD=""

XAUTHORITY=${XAUTHORITY:-"$HOME/.Xauthority"}


if [ "$X2GO_STYPE" == "S" ]; then

	SHADOW_MODE=`echo $X2GO_CMD |awk '{split($0,a,"XSHAD"); print a[1]}'`
	SHADOW_USER=`echo $X2GO_CMD |awk '{split($0,a,"XSHAD"); print a[2]}'`
	SHADOW_DESKTOP=`echo $X2GO_CMD |awk '{split($0,a,"XSHAD"); print a[3]}'`

	if [ -z "$1" ]; then

		# can this line be removed?
		#echo "suser $SHADOW_USER user $USER " >> /tmp/uagent

		$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "shadow session requested: mode $SHADOW_MODE, user: $SHADOW_USER, desktop: $SHADOW_DESKTOP"
	else
		SHADREQ_USER="$1"; shift
		$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "preparing shadow session request for user $SHADREQ_USER, agent starts for user ${USER}"
	fi

	if [ "$SHADOW_USER" != "$USER" ]; then

		$X2GO_LIB_PATH/x2gosyslog "$0" "notice" "user ,,$USER'' requests desktop sharing from user ,,$SHADOW_USER'' for desktop ,,$SHADOW_DESKTOP''"
		$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "executing command: x2godesktopsharing client $X2GO_CLIENT $X2GO_GEOMETRY $X2GO_LINK $X2GO_PACK $X2GO_TYPE $X2GO_KBD_LAYOUT $X2GO_KBD_TYPE $X2GO_SET_KBD $X2GO_STYPE $X2GO_CMD $USER"
		OUTPUT=`x2godesktopsharing client "$X2GO_CLIENT" "$X2GO_GEOMETRY" "$X2GO_LINK" "$X2GO_PACK" "$X2GO_TYPE" "$X2GO_KBD_LAYOUT" "$X2GO_KBD_TYPE" "$X2GO_SET_KBD" "$X2GO_STYPE" "$X2GO_CMD" "$USER"`
		$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "command result is: $OUTPUT"
		if [ "${OUTPUT:0:4}" == "DENY" ]; then
			echo "ACCESS DENIED" 1>&2
			DENIAL_REASON="${OUTPUT:5}"
			if [ -z "$DENIAL_REASON" ]; then
				DENIAL_REASON="the user ,,$SHADOW_USER'' does not seem to have desktop sharing activated"
			fi
			$X2GO_LIB_PATH/x2gosyslog "$0" "err" "ERROR: user $SHADOW_USER denied desktop sharing session"
			$X2GO_LIB_PATH/x2gosyslog "$0" "err" "ERROR: reason: for desktop sharing denial ${DENIAL_REASON}"
			exit -1
		fi
		X2GO_COOKIE=`echo $OUTPUT | awk '{print $2}'`
		X2GO_PORT=`echo $OUTPUT | awk '{print $1}'`

		$X2GO_LIB_PATH/x2gosyslog "$0" "debug" "received shadow session information: cookie: $X2GO_COOKIE, port: $X2GO_PORT"
		xauth -f "$XAUTHORITY" add "${HOSTNAME}/unix:${X2GO_PORT}" MIT-MAGIC-COOKIE-1 "${X2GO_COOKIE}"
		xauth -f "$XAUTHORITY" add "${HOSTNAME}:${X2GO_PORT}" MIT-MAGIC-COOKIE-1 "${X2GO_COOKIE}"

		echo $X2GO_PORT
		echo $X2GO_COOKIE
		echo $OUTPUT | awk '{print $3}'
		echo $OUTPUT | awk '{print $4}'
		echo $OUTPUT | awk '{print $5}'
		echo $OUTPUT | awk '{print $6}'
		echo $OUTPUT | awk '{print $7}'
		exit 0
	else
		X2GO_CLIPBOARD="$1"; shift
	fi
fi

LIMIT=`x2gosessionlimit`
LWORD=`echo $LIMIT | awk '{print $1}'`

if [ "$LWORD" == "LIMIT" ]; then
	echo  $LIMIT 1>&2
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "session limit has been reached for user ,,$USER'', cannot start new session"
	exit -1
fi

export NX_CLIENT="$X2GO_LIB_PATH/x2gosuspend-agent"

COLORDEPTH=`echo $X2GO_TYPE | awk '{split($0,a,"-depth_"); print a[2]}'`

SESSION_TYPE="D"
NOEXITPARAM=""

if [ "$X2GO_STYPE" == "R" ]; then
	SESSION_TYPE="R"
elif  [ "$X2GO_STYPE" == "P" ]; then
	SESSION_TYPE="R"
	NOEXITPARAM="-norootlessexit"
elif  [ "$X2GO_STYPE" == "S" ]; then
	SESSION_TYPE="S"
fi

if [ "$X2GO_CLIENT" == "" ]; then
	X2GO_CLIENT="$HOSTNAME"
fi

# define the full path to the ss utility
ss=$(PATH="$PATH:/usr/sbin:/sbin" type -P ss);

while [ "$OUTPUT"  != "inserted" ]; do

	USED_DISPLAYS=`$X2GO_LIB_PATH/x2gogetdisplays $HOSTNAME`

	#Get all used in system ports from X2Go database and ss output
	USED_PORTS=$(
	    "$X2GO_LIB_PATH/x2gogetports" "$HOSTNAME";
	    "$ss" -nt -all |
	    awk '{ n=split($0,lines,"\n"); for(i=1;i<=n;i++){split (lines[i],words," ");delim=split(words[4],ports,":"); if(delim>1)printf ("|%s|\n",ports[delim])} }';
	);

	X2GO_PORT=$(($X2GO_PORT + 1))
	X2GO_PORT=`echo "for(\\$i=$X2GO_PORT;\\$br ne \"true\";\\$i++){ if(\"$USED_DISPLAYS\" =~ m/\\|\\$i\\|/){\\$br=\"false\";}else{\\$br=\"true\";print \\$i;}}"|perl`
	
	#Test if the session is already in use. nxagent uses 6000+DISPLAY to open a port. Therefore this must be tested, too.
	NX_PORT=$(($X2GO_PORT + 6000))
	if $ss -lxs 2>/dev/null | egrep "(@|)/tmp/.X11-unix/X${X2GO_PORT}(|-lock) " 1>/dev/null ||
		grep -q "|${NX_PORT}|" <<<$USED_PORTS ; then
		OUTPUT="XXX"
	else
		SESSION_NAME="${USER}-${X2GO_PORT}-`date +\"%s\"`"
		if [ "$COLORDEPTH" != "" ]; then
			SESSION_NAME="${SESSION_NAME}_st${SESSION_TYPE}${X2GO_CMD}_dp${COLORDEPTH}"
			SESSION_NAME=`echo "$SESSION_NAME" | perl -pe  "s/:/PP/g"`
		fi
		# sanitize session name
		SESSION_NAME=`echo "$SESSION_NAME" | perl -pe  "s/[^a-zA-Z0-9\.\_\-\@]//g"`

		OUTPUT=`$X2GO_LIB_PATH/x2goinsertsession "$X2GO_PORT" "$HOSTNAME" "$SESSION_NAME"`
	fi 
done


while [ "$GR_PORT" == "" ] || [ "$SOUND_PORT" == "" ] || [ "$FS_PORT" == "" ]; do
	OUTPUT=""
	while [ "$OUTPUT"  != "inserted" ]; do
		SSH_PORT=$(($SSH_PORT + 1))

		#Get all used in system ports from X2Go database and ss output
		USED_PORTS=$(
		    "$X2GO_LIB_PATH/x2gogetports" "$HOSTNAME";
		    "$ss" -nt -all |
		    awk '{ n=split($0,lines,"\n"); for(i=1;i<=n;i++){split (lines[i],words," ");delim=split(words[4],ports,":"); if(delim>1)printf ("|%s|\n",ports[delim])} }';
		);

		#get free port
		SSH_PORT=`echo "for(\\$i=$SSH_PORT;\\$br ne \"true\";\\$i++){ if(\"$USED_PORTS\" =~ m/\\|\\$i\\|/){\\$br=\"false\";}else{\\$br=\"true\";print \\$i;}}"|perl`

		#check if port in /etc/services
		SERV=`grep $SSH_PORT /etc/services`
		if [ "$SERV" == "" ]; then
			OUTPUT=`$X2GO_LIB_PATH/x2goinsertport "$HOSTNAME" "$SESSION_NAME" "$SSH_PORT"`
		fi
	done

	if [ "$GR_PORT" == "" ]; then
		GR_PORT="$SSH_PORT"
	elif [ "$SOUND_PORT" == "" ]; then
		SOUND_PORT="$SSH_PORT"
	else
		FS_PORT="$SSH_PORT"
	fi
done

# rootless sessions of geometry fullscreen are invalid
if [ "$X2GO_GEOMETRY" == "fullscreen" ] && [ "$SESSION_TYPE" == "R" ]; then
	X2GO_GEOMETRY=""
fi

# no geometry for desktop sessions shall result in fullscreen desktop sessions
if [ "$X2GO_GEOMETRY" == "" ] && [ "$SESSION_TYPE" == "D" ]; then
	X2GO_GEOMETRY="fullscreen"
fi
if [ "$X2GO_GEOMETRY" == "fullscreen" ]; then
	X2GO_FULLSCREEN=1
fi

# shadow sessions are never fullscreen session and adopt the original session's geometry
if [ "$X2GO_STYPE" == "S" ]; then
	X2GO_GEOMETRY=`DISPLAY="$SHADOW_DESKTOP" xwininfo -root | grep geometry`
	X2GO_GEOMETRY=`echo "$X2GO_GEOMETRY" | sed  -e  "s/ //g"`
	X2GO_GEOMETRY=`echo "$X2GO_GEOMETRY" | sed  -e  "s/-geometry//"`
fi


if [ ! -d "$X2GO_ROOT" ]; then
	mkdir "$X2GO_ROOT"
fi

X2GO_TMP_ROOT="/tmp/.x2go-${USER}"
if [ ! -d "$X2GO_TMP_ROOT" ]; then
    mkdir "$X2GO_TMP_ROOT"
fi

SESSION_DIR="${X2GO_TMP_ROOT}/C-${SESSION_NAME}"
STATE_FILE="${X2GO_ROOT}/C-${SESSION_NAME}/state"

# do not use $TMP or $TEMP here, the session.log file location has to be accessible by root
SESSION_LOG="${SESSION_DIR}/session.log"
mkdir -p "${SESSION_DIR}"
if [ "x$X2GO_STYPE" = "xS" ]; then
	chmod -f 0710 "${SESSION_DIR}"
	if groups "$USER" | grep x2godesktopsharing 1>/dev/null 2>/dev/null; then
		$X2GO_LIB_PATH/x2gosyslog "$0" "info" "user ,,$USER'' grants access to ${SESSION_DIR} for group ,,x2godesktopsharing''"
		chown :x2godesktopsharing "${SESSION_DIR}"
	fi
else
	chmod -f 0700 "${SESSION_DIR}"
fi
touch "${SESSION_LOG}"
chmod -f 0600 "${SESSION_LOG}"


if [ ! -d "$X2GO_ROOT/ssh" ]; then
    mkdir "$X2GO_ROOT/ssh"
fi

grep PPid /proc/$PPID/status > ${SESSION_DIR}/sshd.pid



X2GO_COOKIE=`mcookie`


PATH="${PATH}:${X2GO_BIN}/"
export PATH


xauth -f "$XAUTHORITY" add "${HOSTNAME}/unix:${X2GO_PORT}" MIT-MAGIC-COOKIE-1 "${X2GO_COOKIE}"
xauth -f "$XAUTHORITY" add "${HOSTNAME}:${X2GO_PORT}" MIT-MAGIC-COOKIE-1 "${X2GO_COOKIE}"


option_geometry=""
if [ -n "$X2GO_GEOMETRY" ] && [ "$X2GO_GEOMETRY" != "fullscreen" ]; then
	option_geometry="geometry=${X2GO_GEOMETRY},"
fi

if [ -n "$X2GO_CLIPBOARD" ] && [ -z "`echo $X2GO_CLIPBOARD | sed -re 's/(0|none|client|server|both|1)//'`" ]; then
	clipboard=",clipboard=$X2GO_CLIPBOARD"
else
	clipboard=",clipboard=both"
fi

if [ "$X2GO_SET_KBD" == "0" ] || [ "$X2GO_KBD_TYPE" == "auto" ];then
    X2GO_HOST="nx/nx,link=${X2GO_LINK},pack=${X2GO_PACK},limit=0,root=${SESSION_DIR},cache=8M,images=32M,type=${X2GO_TYPE},id=${SESSION_NAME},cookie=$X2GO_COOKIE,errors=${SESSION_LOG},kbtype=null/null,${option_geometry}resize=${X2GO_RESIZE},fullscreen=${X2GO_FULLSCREEN},accept=${REMOTE},listen=${GR_PORT}${clipboard},client=linux,menu=0,state=${STATE_FILE}"
else
    X2GO_HOST="nx/nx,link=${X2GO_LINK},pack=${X2GO_PACK},limit=0,root=${SESSION_DIR},cache=8M,images=32M,type=${X2GO_TYPE},id=${SESSION_NAME},cookie=$X2GO_COOKIE,errors=${SESSION_LOG},kbtype=${X2GO_KBD_TYPE},${option_geometry}resize=${X2GO_RESIZE},fullscreen=${X2GO_FULLSCREEN},accept=${REMOTE},listen=${GR_PORT}${clipboard},client=linux,menu=0,state=${STATE_FILE}"
fi


echo "${X2GO_HOST}:${X2GO_PORT}" >"${SESSION_DIR}/options"

NX_AGENT=":${X2GO_PORT}"
SAVED_DISPLAY="$DISPLAY"
DISPLAY="nx/nx,options=${SESSION_DIR}/options:${X2GO_PORT}"
export DISPLAY


if [ "$X2GODPI" == "" ]; then
	X2GODPIOPTION_=""
else
	X2GODPIOPTION_="-dpi $X2GODPI"
fi

NOLISTOPT=""
if [ "$X2GOXDMCP" == "" ] ;then
	XDMCPOPT=""
	if [ "x${X2GO_NXAGENT_OPTIONS}" != "x${X2GO_NXAGENT_OPTIONS/' -nolisten tcp'/''}" ]; then
		NOLISTOPT="-nolisten tcp"
	fi
else
	XDMCPOPT="-query $X2GOXDMCP"
fi

# run x2goserver-extensions for pre-start
x2gofeature X2GO_RUN_EXTENSIONS &>/dev/null && x2goserver-run-extensions "$SESSION_NAME" pre-start || true

SESSION_WINDOW_TITLE="X2GO-${SESSION_NAME}"
agent_geometry=""
if [ -n "$X2GO_GEOMETRY" ] && [ "$X2GO_GEOMETRY" != "fullscreen" ]; then
	agent_geometry="-geometry ${X2GO_GEOMETRY}"
fi

if  [ "$X2GO_STYPE" == "S" ]; then
	# set NX_TEMP to /tmp, make sure x2goagent starts when pam_tmpdir.so is in use
	NX_TEMP=/tmp x2goagent $X2GO_NXAGENT_OPTIONS $NOLISTOPT $X2GODPIOPTION_ -$SESSION_TYPE -auth "$XAUTHORITY" -shadow $SHADOW_DESKTOP -shadowmode $SHADOW_MODE $agent_geometry -name "${SESSION_WINDOW_TITLE}"  "${NX_AGENT}" 2>"${SESSION_LOG}" &
else
	# set NX_TEMP to /tmp, make sure x2goagent starts when pam_tmpdir.so is in use
	NX_TEMP=/tmp x2goagent $X2GO_NXAGENT_OPTIONS $NOLISTOPT $X2GODPIOPTION_ $XDMCPOPT -$SESSION_TYPE $NOEXITPARAM -auth "$XAUTHORITY" $agent_geometry -name "${SESSION_WINDOW_TITLE}"  "${NX_AGENT}" 2>"${SESSION_LOG}" &
fi

ln -s "${SESSION_DIR}" "${X2GO_ROOT}/C-${SESSION_NAME}"

X2GO_AGENT_PID=$!
X2GO_AGENT_RETVAL=$?
test $X2GO_AGENT_RETVAL && {
	$X2GO_LIB_PATH/x2gosyslog "$0" "notice" "successfully started X2Go agent session with ID $SESSION_NAME"

	# run x2goserver-extensions for post-start
	x2gofeature X2GO_RUN_EXTENSIONS &>/dev/null && x2goserver-run-extensions "$SESSION_NAME" post-start || true

} || {
	$X2GO_LIB_PATH/x2gosyslog "$0" "err" "ERROR: failed to start X2Go agent session with ID $SESSION_NAME"

	# run x2goserver-extensions for fail-start
	x2gofeature X2GO_RUN_EXTENSIONS &>/dev/null && x2goserver-run-extensions "$SESSION_NAME" fail-start || true

}

X2GO_SND_PORT=1024

$X2GO_LIB_PATH/x2gocreatesession "$X2GO_COOKIE" "$X2GO_AGENT_PID" "$X2GO_CLIENT" "$GR_PORT" "$SOUND_PORT" "$FS_PORT" "$SESSION_NAME" > /dev/null

if [ "$X2GO_SET_KBD" == "0" ] || [ "$X2GO_KBD_TYPE" != "auto" ]; then
	$X2GO_LIB_PATH/x2gosyslog "$0" "info" "blocking creation of agent's keyboard file ${SESSION_DIR}/keyboard as requested by session startup command"
	mkdir -p ${SESSION_DIR}/keyboard
fi

echo $X2GO_PORT
echo $X2GO_COOKIE
echo $X2GO_AGENT_PID
echo $SESSION_NAME
echo $GR_PORT
echo $SOUND_PORT
echo $FS_PORT