Initial import of rusticata-macros-3.1.0
Bug: 193833713
Change-Id: I8c64a1f7a387fb4162d80d201b1cfcd7172ed0f3
diff --git a/src/macros.rs b/src/macros.rs
new file mode 100644
index 0000000..c74cb4e
--- /dev/null
+++ b/src/macros.rs
@@ -0,0 +1,406 @@
+//! Helper macros
+
+use nom::bytes::complete::take;
+use nom::combinator::map_res;
+use nom::combinator::rest;
+pub use nom::error::{make_error, ErrorKind, ParseError};
+use nom::HexDisplay;
+pub use nom::{IResult, Needed};
+
+#[doc(hidden)]
+pub mod export {
+ pub use core::{fmt, mem, ptr};
+}
+
+/// Helper macro for newtypes: declare associated constants and implement Display trait
+#[macro_export]
+macro_rules! newtype_enum (
+ (@collect_impl, $name:ident, $($key:ident = $val:expr),* $(,)*) => {
+ $( pub const $key : $name = $name($val); )*
+ };
+
+ (@collect_disp, $name:ident, $f:ident, $m:expr, $($key:ident = $val:expr),* $(,)*) => {
+ match $m {
+ $( $val => write!($f, stringify!{$key}), )*
+ n => write!($f, "{}({} / 0x{:x})", stringify!{$name}, n, n)
+ }
+ };
+
+ // entry
+ (impl $name:ident {$($body:tt)*}) => (
+ #[allow(non_upper_case_globals)]
+ impl $name {
+ newtype_enum!{@collect_impl, $name, $($body)*}
+ }
+ );
+
+ // entry with display
+ (impl display $name:ident {$($body:tt)*}) => (
+ newtype_enum!(impl $name { $($body)* });
+
+ impl $crate::export::fmt::Display for $name {
+ fn fmt(&self, f: &mut $crate::export::fmt::Formatter) -> $crate::export::fmt::Result {
+ newtype_enum!(@collect_disp, $name, f, self.0, $($body)*)
+ }
+ }
+ );
+
+ // entry with display and debug
+ (impl debug $name:ident {$($body:tt)*}) => (
+ newtype_enum!(impl display $name { $($body)* });
+
+ impl $crate::export::fmt::Debug for $name {
+ fn fmt(&self, f: &mut $crate::export::fmt::Formatter) -> $crate::export::fmt::Result {
+ write!(f, "{}", self)
+ }
+ }
+ );
+);
+
+/// Helper macro for nom parsers: raise error if the condition is true
+///
+/// This macro is used when using custom errors
+#[macro_export]
+macro_rules! custom_check (
+ ($i:expr, $cond:expr, $err:expr) => (
+ {
+ if $cond {
+ Err(::nom::Err::Error($err))
+ } else {
+ Ok(($i, ()))
+ }
+ }
+ );
+);
+
+/// Helper macro for nom parsers: raise error if the condition is true
+///
+/// This macro is used when using `ErrorKind`
+#[macro_export]
+macro_rules! error_if (
+ ($i:expr, $cond:expr, $err:expr) => (
+ {
+ use nom::error_position;
+ if $cond {
+ Err(::nom::Err::Error(error_position!($i, $err)))
+ } else {
+ Ok(($i, ()))
+ }
+ }
+ );
+);
+
+/// Helper macro for nom parsers: raise error if input is not empty
+///
+/// Deprecated - use `nom::eof`
+#[macro_export]
+#[deprecated(since = "2.0.0")]
+macro_rules! empty (
+ ($i:expr,) => (
+ {
+ use nom::eof;
+ eof!($i,)
+ }
+ );
+);
+
+/// Helper macro for nom parsers: run first parser if condition is true, else second parser
+#[macro_export]
+macro_rules! cond_else (
+ ($i:expr, $cond:expr, $expr_then:ident!($($args_then:tt)*), $expr_else:ident!($($args_else:tt)*)) => (
+ {
+ if $cond { $expr_then!($i, $($args_then)*) }
+ else { $expr_else!($i, $($args_else)*) }
+ }
+ );
+ ($i:expr, $cond:expr, $expr_then:expr, $expr_else:ident!($($args_else:tt)*)) => (
+ cond_else!($i, $cond, call!($expr_then), $expr_else!($($args_else)*))
+ );
+ ($i:expr, $cond:expr, $expr_then:ident!($($args_then:tt)*), $expr_else:expr) => (
+ cond_else!($i, $cond, $expr_then!($($args_then)*), call!($expr_else))
+ );
+ ($i:expr, $cond:expr, $expr_then:expr, $expr_else:expr) => (
+ cond_else!($i, $cond, call!($expr_then), call!($expr_else))
+ );
+);
+
+/// Dump the remaining bytes to stderr, formatted as hex
+pub fn dbg_dmp_rest(i: &[u8]) -> IResult<&[u8], ()> {
+ map!(i, peek!(call!(rest)), |r| eprintln!("\n{}\n", r.to_hex(16)))
+}
+
+#[deprecated(since = "3.0.1", note = "please use `be_var_u64` instead")]
+/// Read an entire slice as a big-endian value.
+///
+/// Returns the value as `u64`. This function checks for integer overflows, and returns a
+/// `Result::Err` value if the value is too big.
+pub fn bytes_to_u64(s: &[u8]) -> Result<u64, &'static str> {
+ let mut u: u64 = 0;
+
+ if s.is_empty() {
+ return Err("empty");
+ };
+ if s.len() > 8 {
+ return Err("overflow");
+ }
+ for &c in s {
+ let u1 = u << 8;
+ u = u1 | (c as u64);
+ }
+
+ Ok(u)
+}
+
+/// Read a slice as a big-endian value.
+#[macro_export]
+macro_rules! parse_hex_to_u64 (
+ ( $i:expr, $size:expr ) => {
+ map_res(take($size as usize), $crate::combinator::be_var_u64)($i)
+ };
+);
+
+/// Read 3 bytes as an unsigned integer
+#[deprecated(since = "0.5.0", note = "please use `be_u24` instead")]
+#[allow(deprecated)]
+#[inline]
+pub fn parse_uint24(i: &[u8]) -> IResult<&[u8], u64> {
+ map_res(take(3usize), bytes_to_u64)(i)
+}
+
+//named!(parse_hex4<&[u8], u64>, parse_hex_to_u64!(4));
+
+/// Parse a slice and return a fixed-sized array of bytes
+///
+/// This creates a copy of input data
+/// Uses unsafe code
+#[macro_export]
+macro_rules! slice_fixed(
+ ( $i:expr, $count:expr ) => (
+ {
+ let cnt = $count;
+ let ires: IResult<_,_> = if $i.len() < cnt {
+ Err(::nom::Err::Incomplete(Needed::new(cnt)))
+ } else {
+ let mut res: [u8; $count] = unsafe {
+ $crate::export::mem::MaybeUninit::uninit().assume_init()
+ };
+ unsafe{$crate::export::ptr::copy($i.as_ptr(), res.as_mut_ptr(), cnt)};
+ Ok((&$i[cnt..],res))
+ };
+ ires
+ }
+ );
+);
+
+/// Combination and flat_map! and take! as first combinator
+#[macro_export]
+macro_rules! flat_take (
+ ($i:expr, $len:expr, $f:ident) => ({
+ if $i.len() < $len { Err(::nom::Err::Incomplete(::nom::Needed::new($len))) }
+ else {
+ let taken = &$i[0..$len];
+ let rem = &$i[$len..];
+ match $f(taken) {
+ Ok((_,res)) => Ok((rem,res)),
+ Err(e) => Err(e)
+ }
+ }
+ });
+ ($i:expr, $len:expr, $submac:ident!( $($args:tt)*)) => ({
+ if $i.len() < $len { Err(::nom::Err::Incomplete(::nom::Needed::new($len))) }
+ else {
+ let taken = &$i[0..$len];
+ let rem = &$i[$len..];
+ match $submac!(taken, $($args)*) {
+ Ok((_,res)) => Ok((rem,res)),
+ Err(e) => Err(e)
+ }
+ }
+ });
+);
+
+/// Apply combinator, trying to "upgrade" error to next error type (using the `Into` or `From`
+/// traits).
+#[macro_export]
+macro_rules! upgrade_error (
+ ($i:expr, $submac:ident!( $($args:tt)*) ) => ({
+ upgrade_error!( $submac!( $i, $($args)* ) )
+ });
+ ($i:expr, $f:expr) => ({
+ upgrade_error!( call!($i, $f) )
+ });
+ ($e:expr) => ({
+ match $e {
+ Ok(o) => Ok(o),
+ Err(::nom::Err::Error(e)) => Err(::nom::Err::Error(e.into())),
+ Err(::nom::Err::Failure(e)) => Err(::nom::Err::Failure(e.into())),
+ Err(::nom::Err::Incomplete(i)) => Err(::nom::Err::Incomplete(i)),
+ }
+ });
+);
+
+/// Apply combinator, trying to "upgrade" error to next error type (using the `Into` or `From`
+/// traits).
+#[macro_export]
+macro_rules! upgrade_error_to (
+ ($i:expr, $ty:ty, $submac:ident!( $($args:tt)*) ) => ({
+ upgrade_error_to!( $ty, $submac!( $i, $($args)* ) )
+ });
+ ($i:expr, $ty:ty, $f:expr) => ({
+ upgrade_error_to!( $ty, call!($i, $f) )
+ });
+ ($ty:ty, $e:expr) => ({
+ match $e {
+ Ok(o) => Ok(o),
+ Err(::nom::Err::Error(e)) => Err(::nom::Err::Error(e.into::<$ty>())),
+ Err(::nom::Err::Failure(e)) => Err(::nom::Err::Failure(e.into::<$ty>())),
+ Err(::nom::Err::Incomplete(i)) => Err(::nom::Err::Incomplete(i)),
+ }
+ });
+);
+
+/// Nom combinator that returns the given expression unchanged
+#[macro_export]
+macro_rules! q {
+ ($i:expr, $x:expr) => {{
+ Ok(($i, $x))
+ }};
+}
+
+/// Align input value to the next multiple of n bytes
+/// Valid only if n is a power of 2
+#[macro_export]
+macro_rules! align_n2 {
+ ($x:expr, $n:expr) => {
+ ($x + ($n - 1)) & !($n - 1)
+ };
+}
+
+/// Align input value to the next multiple of 4 bytes
+#[macro_export]
+macro_rules! align32 {
+ ($x:expr) => {
+ $crate::align_n2!($x, 4)
+ };
+}
+
+#[cfg(test)]
+mod tests {
+ use nom::error::ErrorKind;
+ use nom::number::streaming::{be_u16, be_u32, be_u8};
+ use nom::{Err, IResult, Needed};
+
+ #[test]
+ #[allow(unsafe_code)]
+ fn test_slice_fixed() {
+ let empty = &b""[..];
+ let b = &[0x01, 0x02, 0x03, 0x04, 0x05];
+
+ let res = slice_fixed!(b, 4);
+ assert_eq!(res, Ok((&b[4..], [1, 2, 3, 4])));
+
+ // can we still use the result ?
+ match res {
+ Ok((rem, _)) => {
+ let res2: IResult<&[u8], u8> = be_u8(rem);
+ assert_eq!(res2, Ok((empty, 5)));
+ }
+ _ => (),
+ }
+ }
+
+ #[test]
+ #[allow(unsafe_code)]
+ fn test_slice_fixed_incomplete() {
+ let b = &[0x01, 0x02, 0x03, 0x04, 0x05];
+ let res = slice_fixed!(b, 8);
+ assert_eq!(res, Err(Err::Incomplete(Needed::new(8))));
+ }
+
+ #[test]
+ fn test_error_if() {
+ let empty = &b""[..];
+ let res: IResult<&[u8], ()> = error_if!(empty, true, ErrorKind::Tag);
+ assert_eq!(res, Err(Err::Error(error_position!(empty, ErrorKind::Tag))));
+ }
+
+ #[test]
+ fn test_cond_else() {
+ let input = &[0x01][..];
+ let empty = &b""[..];
+ let a = 1;
+ fn parse_u8(i: &[u8]) -> IResult<&[u8], u8> {
+ be_u8(i)
+ }
+ assert_eq!(
+ cond_else!(input, a == 1, call!(parse_u8), value!(0x02)),
+ Ok((empty, 0x01))
+ );
+ assert_eq!(
+ cond_else!(input, a == 1, parse_u8, value!(0x02)),
+ Ok((empty, 0x01))
+ );
+ assert_eq!(
+ cond_else!(input, a == 2, parse_u8, value!(0x02)),
+ Ok((input, 0x02))
+ );
+ assert_eq!(
+ cond_else!(input, a == 1, value!(0x02), parse_u8),
+ Ok((input, 0x02))
+ );
+ let res: IResult<&[u8], u8> = cond_else!(input, a == 1, parse_u8, parse_u8);
+ assert_eq!(res, Ok((empty, 0x01)));
+ }
+
+ #[test]
+ fn test_newtype_enum() {
+ #[derive(Debug, PartialEq, Eq)]
+ struct MyType(pub u8);
+
+ newtype_enum! {
+ impl display MyType {
+ Val1 = 0,
+ Val2 = 1
+ }
+ }
+
+ assert_eq!(MyType(0), MyType::Val1);
+ assert_eq!(MyType(1), MyType::Val2);
+
+ assert_eq!(format!("{}", MyType(0)), "Val1");
+ assert_eq!(format!("{}", MyType(4)), "MyType(4 / 0x4)");
+ }
+ #[test]
+ fn test_flat_take() {
+ let input = &[0x00, 0x01, 0xff];
+ // read first 2 bytes and use correct combinator: OK
+ let res: IResult<&[u8], u16> = flat_take!(input, 2, be_u16);
+ assert_eq!(res, Ok((&input[2..], 0x0001)));
+ // read 3 bytes and use 2: OK (some input is just lost)
+ let res: IResult<&[u8], u16> = flat_take!(input, 3, be_u16);
+ assert_eq!(res, Ok((&b""[..], 0x0001)));
+ // read 2 bytes and a combinator requiring more bytes
+ let res: IResult<&[u8], u32> = flat_take!(input, 2, be_u32);
+ assert_eq!(res, Err(Err::Incomplete(Needed::new(2))));
+ // test with macro as sub-combinator
+ let res: IResult<&[u8], u16> = flat_take!(input, 2, be_u16);
+ assert_eq!(res, Ok((&input[2..], 0x0001)));
+ }
+
+ #[test]
+ fn test_q() {
+ let empty = &b""[..];
+ let res: IResult<&[u8], &str, ErrorKind> = q!(empty, "test");
+ assert_eq!(res, Ok((empty, "test")));
+ }
+
+ #[test]
+ fn test_align32() {
+ assert_eq!(align32!(3), 4);
+ assert_eq!(align32!(4), 4);
+ assert_eq!(align32!(5), 8);
+ assert_eq!(align32!(5u32), 8);
+ assert_eq!(align32!(5i32), 8);
+ assert_eq!(align32!(5usize), 8);
+ }
+}