e9syscall

#!/bin/bash
#
# Copyright (C) 2023 National University of Singapore
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

if [ -t 1 ]
then
    RED="\033[31m"
    GREEN="\033[32m"
    YELLOW="\033[33m"
    BOLD="\033[1m"
    OFF="\033[0m"
else
    RED=
    GREEN=
    YELLOW=
    BOLD=
    OFF=
fi

usage()
{
    echo -e "${RED}usage${OFF}: $0 [OPTIONS] hook.c" >&2
    echo >&2
    echo "OPTIONS:" >&2
    echo "    -l FILE" >&2
    echo "        Use FILE as the libc.so [default: /lib/x86_64-linux-gnu/libc.so.6]" >&2
    echo >&2
    exit 1
}

LIBC=/lib/x86_64-linux-gnu/libc.so.6

while getopts "l:" OPTION
do
    case "$OPTION"
    in
        l)
            LIBC=$OPTARG
            ;;
        *)
            usage
            ;;
    esac
done

shift $((OPTIND-1))
if [ $# != 1 ]
then
    usage
fi

HOOK=$1
HOOKNAME=`basename "$HOOK" .c`

set -e

# STEP (1): check if e9patch is installed:
if [ ! -x ./e9patch ]
then
    echo -e "${RED}error${OFF}: e9patch is not installed (run ./build.sh first) " >&2
fi

# STEP (2): build the hook code:
echo -e "${GREEN}$0${OFF}: building hook ($HOOK)..."
./e9compile.sh e9syscall-rt.c -O2 -Werror -include "$HOOK" -I "$PWD"
mv e9syscall-rt "e9syscall_hook_$HOOKNAME"

# STEP (3): patch libc:
echo -e "${GREEN}$0${OFF}: patching libc ($LIBC)..."
echo "./e9tool -M 'asm=\"syscall\"' -P 'if intercept(&rax,rdi,rsi,rdx,r10,r8,r9)@'\"e9syscall_hook_$HOOKNAME break\" "$LIBC" -o "libc-$HOOKNAME.so""
./e9tool \
    -M  'asm="syscall"' \
    -P 'if intercept(&rax,rdi,rsi,rdx,r10,r8,r9)@'"e9syscall_hook_$HOOKNAME break" \
    "$LIBC" -o "libc-$HOOKNAME.so" | tee "e9patch-$HOOKNAME.log"

echo -e "${GREEN}$0${OFF}: done!"
echo

echo -e "${YELLOW}        ___                          _ _ "
echo -e "   ___ / _ \\ ___ _   _ ___  ___ __ _| | |"
echo -e "  / _ \\ (_) / __| | | / __|/ __/ _\` | | |"
echo -e " |  __/\\__, \\__ \\ |_| \\__ \\ (_| (_| | | |"
echo -e "  \\___|  /_/|___/\\__, |___/\\___\\__,_|_|_|"
echo -e "                 |___/${OFF}"
echo

if grep -e 'num_patched .*(100.00%)' "e9patch-$HOOKNAME.log" > /dev/null
then
    echo -e "${GREEN}SUCCESS${OFF}!"
    echo
    echo -e "Successfully built the patched library ${YELLOW}libc-$HOOKNAME.so${OFF}."
else
    echo -e "${RED}WARNING${OFF}!"
    echo
    echo -e "Built the patched library ${YELLOW}libc-$HOOKNAME.so${OFF}, however 100% coverage was not"
    echo "achieved.  This means that some system calls will not be intercepted."
fi

echo
echo "To use, run the following command:"
echo
echo "    LD_PRELOAD=\"$PWD/libc-$HOOKNAME.so\" command ..."
echo
echo "For example:"
echo
echo "    LD_PRELOAD=\"$PWD/libc-$HOOKNAME.so\" ls -l"
echo