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#![allow(dead_code)]
#[macro_use]
extern crate bitfield;
use std::net::Ipv4Addr;
bitfield! {
struct IpV4Header(MSB0 [u8]);
impl Debug;
u32;
get_version, _: 3, 0;
get_ihl, _: 7, 4;
get_dscp, _: 13, 8;
get_ecn, _: 15, 14;
get_total_length, _: 31, 16;
get_identification, _: 47, 32;
get_df, _: 49;
get_mf, _: 50;
get_fragment_offset, _: 63, 51;
get_time_to_live, _: 71, 64;
get_protocol, _: 79, 72;
get_header_checksum, _: 95, 80;
u8, get_source_address, _: 103, 96, 4;
u32, into Ipv4Addr, get_destination_address, _: 159, 128;
}
impl<T: AsRef<[u8]>> IpV4Header<T> {
fn get_source_as_ip_addr(&self) -> Ipv4Addr {
let mut src = [0; 4];
for (i, src) in src.iter_mut().enumerate() {
*src = self.get_source_address(i);
}
src.into()
}
}
fn main() {
let data = [
0x45, 0x00, 0x00, 0x40, 0x69, 0x27, 0x40, 0x00, 0x40, 0x11, 0x4d, 0x0d, 0xc0, 0xa8, 0x01,
0x2a, 0xc0, 0xa8, 0x01, 0xfe,
];
let header = IpV4Header(data);
assert_eq!(header.get_version(), 4);
assert_eq!(header.get_total_length(), 64);
assert_eq!(header.get_identification(), 0x6927);
assert!(header.get_df());
assert!(!header.get_mf());
assert_eq!(header.get_fragment_offset(), 0);
assert_eq!(header.get_protocol(), 0x11);
println!(
"from {} to {}",
header.get_source_as_ip_addr(),
header.get_destination_address()
);
println!("{:#?}", header);
}
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