#!/bin/bash
    #
    #                              Copyright (C) 2015 by Rafael Santiago
    #
    # This is free software. You can redistribute it and/or modify under
    # the terms of the GNU General Public License version 2.
    #
    # "snail.sh"
    #       by Rafael Santiago
    #
    # Description: a simple script which scans ELF dependencies.
    #

    SNAIL_TEMP_DIR=".snail"

    SNAIL_LD_32=""

    SNAIL_LD_64=""

    SHOULD_REMOVE_INTERP=0

    INTERP_PATH=""

    function snail_find_app_deps() {
        printf "\t\t@@@ - Inspecting %s's dependencies...\n" $1
        for libpath in $(LD_TRACE_LOADED_OBJECTS=1 $1 | grep ".*/" | sed s/.*=\>// | sed s/\(.*//)
        do
        filename=$(echo ${libpath} | sed s/.*\\///)
        file_exists=$(ls -1 ${SNAIL_TEMP_DIR}/${filename} 2>/dev/null | wc -l)
        if [ ${file_exists} -eq 0 ] ; then
            printf "\t\t\t@@@ - copying: %s... " ${filename}
                cp ${libpath} ${SNAIL_TEMP_DIR}/ &>/dev/null
                if [ $? -eq 0 ] ; then
                printf "copied.\n"
                else
                printf "copy error... aborting.\n"
                fini_snail
                exit 1
                fi
            else
                printf "\t\t\t@@@ - already copied: %s.\n" ${filename}
        fi
        done
        printf "\t\t@@@ - done.\n"
    }

    function snail_find_so_deps() {
        ld_so=${SNAIL_LD_32}
        if [ $(get_platform_arch) -eq 64 ] ; then
            ld_so=${SNAIL_LD_64}
        fi
        printf "\t\t@@@ - Inspecting %s's dependencies...\n" $1
        for libpath in $(LD_TRACE_LOADED_OBJECTS=1 ${ld_so} ./$1 | grep ".*/" | sed s/.*=\>// | sed s/\(.*//)
        do
            filename=$(echo ${libpath} | sed s/.*\\///)
            file_exists=$(ls -1 ${SNAIL_TEMP_DIR}/${filename} 2>/dev/null | wc -l)
            if [ ${file_exists} -eq 0 ] ; then
                printf "\t\t\t@@@ - copying: %s... " ${filename}
                cp ${libpath} ${SNAIL_TEMP_DIR}/ &>/dev/null
                if [ $? -eq 0 ] ; then
                    printf "copied.\n"
                else
                    printf "copy error... aborting.\n"
                    fini_snail
                    exit 1
                fi
            else
                printf "\t\t\t@@@ - already copied: %s.\n" ${filename}
            fi
        done
        printf "\t\t@@@ - done.\n"
        filename=$(echo ${ld_so} | sed s/.*\\///)
        file_exists=$(ls -1 ${SNAIL_TEMP_DIR}/${filename} 2>/dev/null | wc -l)
        if [ ${file_exists} -eq 0 ] ; then
            printf "\t\t@@@ - copying: %s... " ${filename}
            if [ $? -eq 0 ] ; then
                printf "copied.\n"
            else
                printf "copy error... aborting.\n"
                fini_snail
                exit 1
            fi
        fi
    }

    function is_a_so() {
        retval=0
        if [ $(file $1 | grep ".*: ELF.*shared object," | wc -l) -eq 1 ] ; then
            retval=1
        fi
        echo ${retval}
    }

    function get_elf_arch() {
        retval=32
        if [ $(file $1 | grep ".*: ELF 64-bit" | wc -l) -eq 1 ] ; then
            retval=64
        fi
        echo ${retval}
    }

    function find_ld_linux32() {
        SNAIL_LD_32=$(find / -name "ld-linux.so.2" -executable | tail -1)
    }

    function find_ld_linux64() {
        SNAIL_LD_64=$(find / -name "ld-linux-x86-64.so.2" -executable | tail -1)
    }

    function get_platform_arch() {
        retval=32
        if [ $(uname -a | grep ".*x86_64" | wc -l) -eq 1 ] ; then
            retval=64
        fi
        echo ${retval}
    }

    function init_snail() {
        rm -rf ${SNAIL_TEMP_DIR}
        mkdir ${SNAIL_TEMP_DIR}
        find_ld_linux32
        if [ $(get_platform_arch) -eq 64 ] ; then
            find_ld_linux64
        fi
        setup_interp $1
    }

    function setup_interp() {
        interp_path=""
        for filename in $(ls -1 $1)
        do
            if [ $(file $1/${filename} | grep ".*: ELF" | wc -l) -eq 1 ] ; then
                if [ $(is_a_so $1/${filename}) -ne 1 ] ; then
                    interp_path=$(readelf -l $1/${filename} | grep "\\[.*:.*\\]" | sed s/.*\\[// | sed s/.*:// | sed s/\\].*//)
                fi
            fi
        done
        if [ ! -z ${interp_path} ] ; then
            filename=$(echo ${interp_path} | sed s/.*\\///)
            INTERP_PATH=$(echo ${interp_path} | sed s/${filename}//)
            if [ -f ${interp_path} ] ; then
                SHOULD_REMOVE_INTERP=0
            else
                SHOULD_REMOVE_INTERP=1
                mkdir -p ${INTERP_PATH}
                if [ $(get_platform_arch) -eq 32 ] ; then
                    cp ${SNAIL_LD_32} ${filepath} &>/dev/null
                else
                    cp ${SNAIL_LD_64} ${filepath} &>/dev/null
                fi
            fi
        fi
    }

    function fini_snail() {
        rm -rf ${SNAIL_TEMP_DIR}
        if [ ${SHOULD_REMOVE_INTERP} -eq 1 ] ; then
            rm -rf ${INTERP_PATH} &>/dev/null
        fi
    }

    function zip_deps() {
        printf "@@@ - Zipping all collected dependencies into %s... " $1
        rm $1 &>/dev/null
        zip -j $1 ${SNAIL_TEMP_DIR}/* &>/dev/null
        if [ $? -eq 0 ] ; then
            printf "ok.\n"
        else
            printf "zip error... aborting.\n"
            fini_snail
            exit 1
        fi
        printf "@@@ - done.\n"
    }

    function snail() {
        printf "@@@@@@@@@@@@@@@@@@@@@\n"
        printf "@@@ - S n a i l - @@@\n"
        printf "@@@@@@@@@@@@@@@@@@@@@\n\n"
        printf "@@@ - Initialising...\n"
        init_snail $1
        printf "@@@ - done.\n\n"
        printf "@@@ - Now, looking for ELFs in directory %s...\n" $1
        for filename in $(ls -1 $1)
        do
            if [ $(file $1/${filename} | grep ".*: ELF" | wc -l) -eq 1 ] ; then
                if [ $(is_a_so $1/${filename}) -eq 1 ] ; then
                    printf "\t@@@ - Shared object: %s\n" $1/${filename}
                    snail_find_so_deps $1/${filename}
                else
                    printf "\t@@@ - Executable found: %s\n" $1/${filename}
                    snail_find_app_deps $1/${filename}
                fi
            fi
        done
        printf "@@@ - done.\n"
        zip_deps $2
        fini_snail

    }

    # main() {

    directory=""
    output=""

    while test -n "$1"
    do
        case "$1" in
            -d | --directory)
                shift
                directory="$1"
                ;;

            -o | --output)
                shift
                output="$1"
                ;;

            -h | --help)
                printf "use: $0 --directory <directory containing your binaries> --output <output file path>\n"
                exit 1
                ;;
        esac
        shift
    done

    if [ -z ${directory} ] ; then
        printf "error: --directory option is missing.\n"
        exit 1
    fi

    if [ -z ${output} ] ; then
        printf "error: --output option is missing.\n"
        exit 1
    fi

    snail ${directory} ${output}

    # }