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use nom::{be_i8,be_u8,be_u16,be_u32,be_u64};
use enum_primitive::FromPrimitive;
enum_from_primitive! {
#[derive(Debug,PartialEq)]
#[repr(u8)]
pub enum NtpMode {
Reserved = 0,
SymmetricActive = 1,
SymmetricPassive = 2,
Client = 3,
Server = 4,
Broadcast = 5,
NtpControlMessage = 6,
Private = 7,
}
}
#[derive(Debug,PartialEq)]
pub struct NtpPacket<'a> {
pub li: u8,
pub version: u8,
pub mode: u8,
pub stratum: u8,
pub poll: i8,
pub precision: i8,
pub root_delay: u32,
pub root_dispersion: u32,
pub ref_id:u32,
pub ts_ref:u64,
pub ts_orig:u64,
pub ts_recv:u64,
pub ts_xmit:u64,
pub ext_and_auth:Option<(Vec<NtpExtension<'a>>, (u32, &'a[u8]))>,
pub auth: Option<(u32,&'a[u8])>,
}
impl<'a> NtpPacket<'a> {
#[inline]
pub fn get_mode(&self) -> Option<NtpMode> {
NtpMode::from_u8(self.mode)
}
pub fn get_precision(&self) -> f32 {
2.0_f32.powf(self.precision as f32)
}
}
#[derive(Debug,PartialEq)]
pub struct NtpExtension<'a> {
pub field_type: u16,
pub length: u16,
pub value: &'a[u8],
}
named!(pub parse_ntp_extension<NtpExtension>,
do_parse!(
ty: be_u16
>> len: be_u16
>> data: take!(len)
>> (
NtpExtension{
field_type:ty,
length:len,
value:data,
}
))
);
named!(pub parse_ntp_key_mac<(u32,&[u8])>,
complete!(pair!(be_u32,take!(16)))
);
named!(pub parse_ntp<NtpPacket>,
do_parse!(
b0: bits!(
tuple!(take_bits!(u8,2),take_bits!(u8,3),take_bits!(u8,3))
)
>> st: be_u8
>> pl: be_i8
>> pr: be_i8
>> rde: be_u32
>> rdi: be_u32
>> rid: be_u32
>> tsr: be_u64
>> tso: be_u64
>> tsv: be_u64
>> tsx: be_u64
>> extn: opt!(complete!(pair!(many0!(complete!(parse_ntp_extension)),parse_ntp_key_mac)))
>> auth: opt!(parse_ntp_key_mac)
>> (
NtpPacket {
li:b0.0,
version:b0.1,
mode:b0.2,
stratum:st,
poll:pl,
precision:pr,
root_delay:rde,
root_dispersion:rdi,
ref_id:rid,
ts_ref:tsr,
ts_orig:tso,
ts_recv:tsv,
ts_xmit:tsx,
ext_and_auth:extn,
auth:auth,
}
))
);
#[cfg(test)]
mod tests {
use ntp::*;
use nom::IResult;
static NTP_REQ1: &'static [u8] = &[
0xd9, 0x00, 0x0a, 0xfa, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x90,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0xc5, 0x02, 0x04, 0xec, 0xec, 0x42, 0xee, 0x92
];
#[test]
fn test_ntp_packet1() {
let empty = &b""[..];
let bytes = NTP_REQ1;
let expected = IResult::Done(empty,NtpPacket{
li:3,
version:3,
mode:1,
stratum:0,
poll:10,
precision:-6,
root_delay:0,
root_dispersion:0x010290,
ref_id:0,
ts_ref:0,
ts_orig:0,
ts_recv:0,
ts_xmit:14195914391047827090u64,
ext_and_auth:None,
auth:None,
});
let res = parse_ntp(&bytes);
assert_eq!(res, expected);
}
static NTP_REQ2: &'static [u8] = &[
0x23, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0xcc, 0x25, 0xcc, 0x13, 0x2b, 0x02, 0x10, 0x00,
0x00, 0x00, 0x00, 0x01, 0x52, 0x80, 0x0c, 0x2b, 0x59, 0x00, 0x64, 0x66,
0x84, 0xf4, 0x4c, 0xa4, 0xee, 0xce, 0x12, 0xb8
];
#[test]
fn test_ntp_packet2() {
let empty = &b""[..];
let bytes = NTP_REQ2;
let expected = IResult::Done(empty,NtpPacket{
li:0,
version:4,
mode:3,
stratum:0,
poll:0,
precision:0,
root_delay:12,
root_dispersion:0,
ref_id:0,
ts_ref:0,
ts_orig:0,
ts_recv:0,
ts_xmit:14710388140573593600,
ext_and_auth:None,
auth:Some((1,&bytes[52..])),
});
let res = parse_ntp(&bytes);
assert_eq!(res, expected);
}
}