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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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66
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> { fn parse_server_name(i: &[u8]) -> IResult<&[u8], &str> {
let (i, val) = take(64usize)(i)?; let nullbyte_position = i.iter().position(|v| *v == b'\0').unwrap_or(64);
let nullbyte_position = val.iter().position(|v| *v == b'\0').unwrap_or(64); let val = unsafe { std::str::from_utf8_unchecked(&i[..nullbyte_position]) };
let val = unsafe { std::str::from_utf8_unchecked(&val[..nullbyte_position]) };
Ok((i, val)) Ok((i, val))
} }
fn parse_file(i: &[u8]) -> IResult<&[u8], &Path> { fn parse_file(i: &[u8]) -> IResult<&[u8], &Path> {
let (i, val) = take(128usize)(i)?; let nullbyte_position = i.iter().position(|v| *v == b'\0').unwrap_or(128);
let nullbyte_position = val.iter().position(|v| *v == b'\0').unwrap_or(128); let val = unsafe { std::str::from_utf8_unchecked(&i[..nullbyte_position]) };
let val = unsafe { std::str::from_utf8_unchecked(&val[..nullbyte_position]) };
Ok((i, Path::new(val))) 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, gateway_address) = parse_ipv4_address(packet)?;
let (packet, client_hardware_address) = let (packet, client_hardware_address) =
parse_client_hardware_address(packet, hardware_address_length)?; parse_client_hardware_address(packet, hardware_address_length)?;
let potential_options = packet; let (packet, server_name_bytes) = take(64usize)(packet)?;
let (packet, file_name_bytes) = take(128usize)(packet)?;
let (packet, server_name) = parse_server_name(packet)?; let (_, server_name) = parse_server_name(server_name_bytes)?;
let (packet, file_name) = parse_file(packet)?; let (_, file_name) = parse_file(file_name_bytes)?;
Ok(( Ok((
packet, packet,
@ -141,30 +140,39 @@ fn parse_dhcp_packet(packet: &[u8]) -> IResult<&[u8], DhcpMessage> {
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
static DHCP_PACKET: &'static [u8] = include_bytes!("../dhcp_discover.bin"); #[rustfmt::skip]
static DHCP_PACKET2: &'static [u8] = &[ static DHCP_PACKET: &'static [u8] = &[
0x01, 0x01, 0x06, 0x05, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x7f, 0x00, 0x00, 0x01, // op
0x01, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00, 0x01, 0x54, 0x05, 0xdb, 0xa6, 0x96, 0xd0, 0x01, // htype
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //CHADDR padding 0x06, // hlen
0x49, 0x20, 0x62, 0x69, 0x6D, 0x73, 0x20, 0x31, 0x20, 0x44, 0x48, 0x43, 0x50, 0x20, 0x53, 0x05, // hops
0x65, 0x72, 0x76, 0x65, 0x72, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // xid
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, // secs
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // flags
0x00, 0x00, 0x00, 0x00, // server name with padding 0x7f, 0x00, 0x00, 0x01, // ciaddr
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x00, 0x00, 0x01, // siaddr
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x00, 0x00, 0x01, // giaddr
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // chaddr
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x05, 0xdb, 0xa6, 0x96, 0xd0, 0x00, 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
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x49, 0x20, 0x62, 0x69, 0x6D, 0x73, 0x20, 0x31, 0x20, 0x44, 0x48, 0x43, 0x50, 0x20, 0x53, 0x65,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 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, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // file with padding 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] #[test]
fn parses() { fn parses() {
let res = super::parse_dhcp_packet(DHCP_PACKET2).unwrap(); let res = super::parse_dhcp_packet(DHCP_PACKET).unwrap();
dbg!(res); dbg!(res);
} }
} }