#!/bin/bash

#
# libseccomp syscall validation script
#
# Copyright (c) 2014 Red Hat <pmoore@redhat.com>
# Author: Paul Moore <paul@paul-moore.com>
#

#
# This library is free software; you can redistribute it and/or modify it
# under the terms of version 2.1 of the GNU Lesser General Public License as
# published by the Free Software Foundation.
#
# This library 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 Lesser General Public License
# for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library; if not, see <http://www.gnu.org/licenses>.
#

LIB_SYS_DUMP="./arch-syscall-dump"

####
# functions

#
# Dependency check
#
# Arguments:
#     1    Dependency to check for
#
function check_deps() {
	[[ -z "$1" ]] && return
	which "$1" >& /dev/null
	return $?
}

#
# Dependency verification
#
# Arguments:
#     1    Dependency to check for
#
function verify_deps() {
	[[ -z "$1" ]] && return
	if ! check_deps "$1"; then
		echo "error: install \"$1\" and include it in your \$PATH"
		exit 1
	fi
}

#
# Print out script usage details
#
function usage() {
cat << EOF
usage: arch-syscall-validate [-h] [-a <arch>] <kernel_directory>

libseccomp syscall validation script
optional arguments:
  -h             show this help message and exit
  -a             architecture
  -l             output the library's syscall definitions
  -s             output the system's syscall definitions
EOF
}

#
# Dump the library syscall table for a given architecture
#
# Arguments:
#     1    architecture
#     2    offset (optional)
#
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_arch() {
	local offset_str=""

	[[ -z $1 ]] && return

	[[ -n $2 ]] && offset_str="-o $2"
	$LIB_SYS_DUMP -a $1 $offset_str | sed -e '/[^\t]\+\t-[0-9]\+/d'
}

#
# Dump the x86 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_x86() {
	cat $1/arch/x86/entry/syscalls/syscall_32.tbl | \
		grep -v "^#" | awk '{ print $3"\t"$1 }' | sed '/^[ \t]*$/d' | \
		sort
}

#
# Dump the x86 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_x86() {
	dump_lib_arch x86
}

#
# Dump the x86_64 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_x86_64() {
	cat $1/arch/x86/entry/syscalls/syscall_64.tbl | \
		grep -v "^#" | awk '{ print $2,$3,$1 }' | sed -e '/^x32/d' | \
		awk '{ print $2"\t"$3 }' | sed '/^[ \t]*$/d' | sort
}

#
# Dump the x86_64 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_x86_64() {
	dump_lib_arch x86_64
}

#
# Dump the x32 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_x32() {
	cat $1/arch/x86/entry/syscalls/syscall_64.tbl | \
		grep -v "^#" | awk '{ print $2,$3,$1 }' | sed -e '/^64/d' | \
		awk '{ print $2"\t"$3 }' | sed '/^[ \t]*$/d' | sort
}

#
# Dump the x32 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_x32() {
	# 1073741824 == 0x40000000
	dump_lib_arch x32 1073741824
}

#
# Dump the arm system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_arm() {
	# NOTE: arm_sync_file_range() and sync_file_range2() share values
	gcc -E -dM -D__ARM_EABI__ $1/arch/arm/include/uapi/asm/unistd.h | \
		grep "^#define __\(ARM_\)*NR_" | \
		grep -v "^#define __NR_OABI_SYSCALL_BASE" | \
		grep -v "^#define __NR_SYSCALL_BASE" | \
		grep -v "^#define __ARM_NR_BASE" | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_SYSCALL_BASE[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t\2/;s/#define[ \t]\+__ARM_NR_\([^ \t]\+\)[ \t]\+(__ARM_NR_BASE[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t983040 + \2/' | \
		while read line; do \
			if echo "$line" | grep -q "+"; then \
				echo "$line" | awk '{ print $1"\t"$2+$4 }'; \
			else \
				echo "$line"; \
			fi; \
		done | \
		sed -e '/#define __NR_sync_file_range2[ \t]\+__NR_arm_sync_file_range/d' | \
		sort
}

#
# Dump the arm library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_arm() {
	# NOTE: arm_sync_file_range() and sync_file_range2() share values
	dump_lib_arch arm | sed -e '/sync_file_range2[ \t]\+341/d'
}

#
# Dump the aarch64 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_aarch64() {
	gcc -E -dM -I$1/include/uapi -D__BITS_PER_LONG=64 $1/include/uapi/asm-generic/unistd.h | \
		grep "^#define __NR_" | \
		sed -e '/__NR_syscalls/d' | \
		sed -e '/__NR_arch_specific_syscall/d' | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+\(.*\)/\1\t\2/' | \
		sed -e 's/__NR3264_statfs/43/' | \
		sed -e 's/__NR3264_ftruncate/46/' | \
		sed -e 's/__NR3264_truncate/45/' | \
		sed -e 's/__NR3264_lseek/62/' | \
		sed -e 's/__NR3264_sendfile/71/' | \
		sed -e 's/__NR3264_fstatat/79/' | \
		sed -e 's/__NR3264_fstatfs/44/' | \
		sed -e 's/__NR3264_fcntl/25/' | \
		sed -e 's/__NR3264_fadvise64/223/' | \
		sed -e 's/__NR3264_mmap/222/' | \
		sed -e 's/__NR3264_fstat/80/' | \
		sed -e 's/__NR3264_lstat/1039/' | \
		sed -e 's/__NR3264_stat/1038/' | \
		sort
}

#
# Dump the aarch64 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_aarch64() {
	dump_lib_arch aarch64
}

#
# Dump the mips system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_mips() {
	# _MIPS_SIM values:
	#   _MIPS_SIM_ABI32 == 1
	#   _MIPS_SIM_NABI32 == 2
	#   _MIPS_SIM_ABI64 == 3
	gcc -E -dM -I$1/arch/mips/include/uapi -D_MIPS_SIM=1 $1/arch/mips/include/uapi/asm/unistd.h | \
		grep "^#define __NR_" | \
		grep -v "^#define __NR_O32_" | \
		grep -v "^#define __NR_N32_" | \
		grep -v "^#define __NR_64_" | \
		grep -v "^#define __NR_Linux" | \
		grep -v "^#define __NR_unused" | \
		grep -v "^#define __NR_reserved" | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_Linux[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t\2/' | \
		sort
}

#
# Dump the mips library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_mips() {
	dump_lib_arch mips 4000
}

#
# Dump the mips64 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_mips64() {
	# _MIPS_SIM values:
	#   _MIPS_SIM_ABI32 == 1
	#   _MIPS_SIM_NABI32 == 2
	#   _MIPS_SIM_ABI64 == 3
	gcc -E -dM -I$1/arch/mips/include/uapi -D_MIPS_SIM=3 $1/arch/mips/include/uapi/asm/unistd.h | \
		grep "^#define __NR_" | \
		grep -v "^#define __NR_O32_" | \
		grep -v "^#define __NR_N32_" | \
		grep -v "^#define __NR_64_" | \
		grep -v "^#define __NR_Linux" | \
		grep -v "^#define __NR_unused" | \
		grep -v "^#define __NR_reserved" | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_Linux[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t\2/' | \
		sort
}

#
# Dump the mips64 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_mips64() {
	dump_lib_arch mips64 5000
}

#
# Dump the mips64n32 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_mips64n32() {
	# _MIPS_SIM values:
	#   _MIPS_SIM_ABI32 == 1
	#   _MIPS_SIM_NABI32 == 2
	#   _MIPS_SIM_ABI64 == 3
	gcc -E -dM -I$1/arch/mips/include/uapi -D_MIPS_SIM=2 $1/arch/mips/include/uapi/asm/unistd.h | \
		grep "^#define __NR_" | \
		grep -v "^#define __NR_O32_" | \
		grep -v "^#define __NR_N32_" | \
		grep -v "^#define __NR_64_" | \
		grep -v "^#define __NR_Linux" | \
		grep -v "^#define __NR_unused" | \
		grep -v "^#define __NR_reserved" | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_Linux[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t\2/' | \
		sort
}

#
# Dump the mips64n32 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_mips64n32() {
	dump_lib_arch mips64n32 6000
}

#
# Dump the ppc system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_ppc() {
	gcc -E -dM $1/arch/powerpc/include/uapi/asm/unistd.h | \
		grep "^#define __NR_" | \
		sed -e 's/#define[ \t]\+__NR_\([a-z0-9_]\+\)[ \t]\+\([0-9]\+\)/\1\t\2/' | \
		sort
}

#
# Dump the ppc library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_ppc() {
	dump_lib_arch ppc
}

#
# Dump the ppc64 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_ppc64() {
	gcc -E -dM -D__powerpc64__ $1/arch/powerpc/include/uapi/asm/unistd.h | \
		grep "^#define __NR_" | \
		sed -e 's/#define[ \t]\+__NR_\([a-z0-9_]\+\)[ \t]\+\([0-9]\+\)/\1\t\2/' | \
		sort
}

#
# Dump the ppc64 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_ppc64() {
	dump_lib_arch ppc64
}

#
# Dump the s390 system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_s390() {
	gcc -E -dM $1/arch/s390/include/uapi/asm/unistd.h | grep __NR | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_timer_create[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t254 + \2/' | \
		while read line; do \
			if echo "$line" | grep -q "+"; then \
				echo "$line" | awk '{ print $1"\t"$2+$4 }'; \
			else \
				echo "$line"; \
			fi; \
		done | \
		sed 's/#define __NR_//g' | sed 's/ /\t/g' | sort
}

#
# Dump the s390 library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_s390() {
	dump_lib_arch s390
}

#
# Dump the s390x system syscall table
#
# Arguments:
#     1    path to the kernel source
#
#  Dump the architecture's syscall table to stdout.
#
function dump_sys_s390x() {
	gcc -E -dM -D __s390x__ $1/arch/s390/include/uapi/asm/unistd.h | grep __NR | \
		sed -e 's/#define[ \t]\+__NR_\([^ \t]\+\)[ \t]\+(__NR_timer_create[ \t]*+[ \t]*\([0-9]\+\)).*/\1\t254 + \2/' | \
		while read line; do \
			if echo "$line" | grep -q "+"; then \
				echo "$line" | awk '{ print $1"\t"$2+$4 }'; \
			else \
				echo "$line"; \
			fi; \
		done | \
		sed 's/#define __NR_//g' | sed 's/ /\t/g' | sort
}

#
# Dump the s390x library syscall table
#
#  Dump the library's syscall table to stdout.
#
function dump_lib_s390x() {
	dump_lib_arch s390x
}

#
# Dump the system syscall table
#
# Arguments:
#     1    architecture
#     2    path to the kernel source
#
#  Dump the system's syscall table to stdout using the given architecture.
#
function dump_sys() {
	case $1 in
	x86)
		dump_sys_x86 "$2"
		;;
	x86_64)
		dump_sys_x86_64 "$2"
		;;
	x32)
		dump_sys_x32 "$2"
		;;
	arm)
		dump_sys_arm "$2"
		;;
	aarch64)
		dump_sys_aarch64 "$2"
		;;
	mips)
		dump_sys_mips "$2"
		;;
	mips64)
		dump_sys_mips64 "$2"
		;;
	mips64n32)
		dump_sys_mips64n32 "$2"
		;;
	ppc)
		dump_sys_ppc "$2"
		;;
	ppc64)
		dump_sys_ppc64 "$2"
		;;
	s390)
		dump_sys_s390 "$2"
		;;
	s390x)
		dump_sys_s390x "$2"
		;;
	*)
		echo ""
		return 1
		;;
	esac

	return 0
}

#
# Dump the library syscall table
#
# Arguments:
#     1    architecture
#
#  Dump the library's syscall table to stdout using the given architecture.
#
function dump_lib() {
	case $1 in
	x86)
		dump_lib_x86
		;;
	x86_64)
		dump_lib_x86_64
		;;
	x32)
		dump_lib_x32
		;;
	arm)
		dump_lib_arm
		;;
	aarch64)
		dump_lib_aarch64
		;;
	mips)
		dump_lib_mips
		;;
	mips64)
		dump_lib_mips64
		;;
	mips64n32)
		dump_lib_mips64n32
		;;
	ppc)
		dump_lib_ppc "$2"
		;;
	ppc64)
		dump_lib_ppc64 "$2"
		;;
	s390)
		dump_lib_s390 "$2"
		;;
	s390x)
		dump_lib_s390x "$2"
		;;
	*)
		echo ""
		return 1
		;;
	esac

	return 0
}

####
# main

verify_deps diff
verify_deps gcc
verify_deps grep
verify_deps mktemp
verify_deps sed
if [[ ! -x $LIB_SYS_DUMP ]]; then
	echo "error: \"$LIB_SYS_DUMP\" is not in the current working directory"
	exit 1
fi

opt_arches=""
opt_sys=""
opt_lib=""

while getopts "a:slh" opt; do
	case $opt in
	a)
		opt_arches+="$OPTARG "
		;;
	s)
		opt_sys=1
		opt_lib=0
		;;
	l)
		opt_sys=0
		opt_lib=1
		;;
	h|*)
		usage
		exit 1
		;;
	esac
done
shift $(($OPTIND - 1))

# defaults
if [[ $opt_arches == "" ]]; then
	opt_arches=" \
		x86 x86_64 x32 \
		arm aarch64 \
		mips mips64 mips64n32 \
		ppc ppc64 \
		s390 s390x"
fi

# sanity checks
kernel_dir="$1"
if [[ -z $kernel_dir ]]; then
	usage
	exit 1
fi
if [[ ! -d $kernel_dir ]]; then
	echo "error: \"$1\" is not a valid directory"
	exit 1
fi

# generate some temp files
tmp_lib=$(mktemp -t syscall_validate_XXXXXX)
tmp_sys=$(mktemp -t syscall_validate_XXXXXX)

# loop through the architectures and compare
for i in $opt_arches; do
	# dump the syscall tables
	dump_lib $i > $tmp_lib
	if [[ $? -ne 0 ]]; then
		echo "error: unknown arch $i"
		exit 1
	fi
	dump_sys $i "$kernel_dir" > $tmp_sys
	if [[ $? -ne 0 ]]; then
		echo "error: unknown arch $i"
		exit 1
	fi

	if [[ $opt_lib -eq 1 ]]; then
		cat $tmp_lib
	elif [[ $opt_sys -eq 1 ]]; then
		cat $tmp_sys
	else
		#  compare the lib and sys output
		diff -u --label="$i [library]" $tmp_lib \
			--label "$i [system]" $tmp_sys
	fi
done

# cleanup and exit
rm -f $tmp_lib $tmp_sys

exit 0