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extend dhcp sample packet and separate file and server_name parsing in preparation for overloaded options parsing

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fuckwit 2023-05-24 20:47:33 +02:00
parent e0cc79198f
commit 0bf69237b9
2 changed files with 38 additions and 30 deletions
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BIN
dhcp_discover.bin
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68
src/lib.rs
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@ -86,17 +86,15 @@ fn parse_client_hardware_address(i: &[u8], hardware_address_length: u8) -> IResu
}
fn parse_server_name(i: &[u8]) -> IResult<&[u8], &str> {
let (i, val) = take(64usize)(i)?;
let nullbyte_position = val.iter().position(|v| *v == b'\0').unwrap_or(64);
let val = unsafe { std::str::from_utf8_unchecked(&val[..nullbyte_position]) };
let nullbyte_position = i.iter().position(|v| *v == b'\0').unwrap_or(64);
let val = unsafe { std::str::from_utf8_unchecked(&i[..nullbyte_position]) };
Ok((i, val))
}
fn parse_file(i: &[u8]) -> IResult<&[u8], &Path> {
let (i, val) = take(128usize)(i)?;
let nullbyte_position = val.iter().position(|v| *v == b'\0').unwrap_or(128);
let val = unsafe { std::str::from_utf8_unchecked(&val[..nullbyte_position]) };
let nullbyte_position = i.iter().position(|v| *v == b'\0').unwrap_or(128);
let val = unsafe { std::str::from_utf8_unchecked(&i[..nullbyte_position]) };
Ok((i, Path::new(val)))
}
@ -114,10 +112,11 @@ fn parse_dhcp_packet(packet: &[u8]) -> IResult<&[u8], DhcpMessage> {
let (packet, gateway_address) = parse_ipv4_address(packet)?;
let (packet, client_hardware_address) =
parse_client_hardware_address(packet, hardware_address_length)?;
let potential_options = packet;
let (packet, server_name) = parse_server_name(packet)?;
let (packet, file_name) = parse_file(packet)?;
let (packet, server_name_bytes) = take(64usize)(packet)?;
let (packet, file_name_bytes) = take(128usize)(packet)?;
let (_, server_name) = parse_server_name(server_name_bytes)?;
let (_, file_name) = parse_file(file_name_bytes)?;
Ok((
packet,
@ -141,30 +140,39 @@ fn parse_dhcp_packet(packet: &[u8]) -> IResult<&[u8], DhcpMessage> {
#[cfg(test)]
mod tests {
static DHCP_PACKET: &'static [u8] = include_bytes!("../dhcp_discover.bin");
static DHCP_PACKET2: &'static [u8] = &[
0x01, 0x01, 0x06, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x7f, 0x00, 0x00,
0x01, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00, 0x01, 0x54, 0x05, 0xdb, 0xa6, 0x96, 0xd0,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //CHADDR padding
0x49, 0x20, 0x62, 0x69, 0x6D, 0x73, 0x20, 0x31, 0x20, 0x44, 0x48, 0x43, 0x50, 0x20, 0x53,
0x65, 0x72, 0x76, 0x65, 0x72, 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, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, // server name with padding
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, 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, 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, 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, // file with padding
#[rustfmt::skip]
static DHCP_PACKET: &'static [u8] = &[
0x01, // op
0x01, // htype
0x06, // hlen
0x05, // hops
0x00, 0x00, 0x00, 0x01, // xid
0x00, 0x02, // secs
0x00, 0x01, // flags
0x7f, 0x00, 0x00, 0x01, // ciaddr
0x7f, 0x00, 0x00, 0x01, // siaddr
0x7f, 0x00, 0x00, 0x01, // giaddr
// chaddr
0x54, 0x05, 0xdb, 0xa6, 0x96, 0xd0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
// server name
0x49, 0x20, 0x62, 0x69, 0x6D, 0x73, 0x20, 0x31, 0x20, 0x44, 0x48, 0x43, 0x50, 0x20, 0x53, 0x65,
0x72, 0x76, 0x65, 0x72, 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, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
// file
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,
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,
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,
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,
];
#[test]
fn parses() {
let res = super::parse_dhcp_packet(DHCP_PACKET2).unwrap();
let res = super::parse_dhcp_packet(DHCP_PACKET).unwrap();
dbg!(res);
}
}