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rust/dhcp: convert parser to nom7 functions

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pull/6581/head
Pierre Chifflier 4 years ago committed by Victor Julien
parent 17170c41aa
commit ebd5883da8
1 changed files with 131 additions and 126 deletions
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257
rust/src/dhcp/parser.rs
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@ -18,9 +18,11 @@
use std::cmp::min;
use crate::dhcp::dhcp::*;
use nom::IResult;
use nom::combinator::rest;
use nom::number::streaming::{be_u8, be_u16, be_u32};
use nom7::bytes::streaming::take;
use nom7::combinator::{complete, verify};
use nom7::multi::many0;
use nom7::number::streaming::{be_u16, be_u32, be_u8};
use nom7::IResult;
pub struct DHCPMessage {
pub header: DHCPHeader,
@ -81,120 +83,124 @@ pub struct DHCPOption {
pub option: DHCPOptionWrapper,
}
named!(pub parse_header<DHCPHeader>,
do_parse!(
opcode: be_u8
>> htype: be_u8
>> hlen: be_u8
>> hops: be_u8
>> txid: be_u32
>> seconds: be_u16
>> flags: be_u16
>> clientip: take!(4)
>> yourip: take!(4)
>> serverip: take!(4)
>> giaddr: take!(4)
>> clienthw: take!(16)
>> servername: take!(64)
>> bootfilename: take!(128)
>> magic: take!(4)
>> (
DHCPHeader{
opcode: opcode,
htype: htype,
hlen: hlen,
hops: hops,
txid: txid,
seconds: seconds,
flags: flags,
clientip: clientip.to_vec(),
yourip: yourip.to_vec(),
serverip: serverip.to_vec(),
giaddr: giaddr.to_vec(),
clienthw: clienthw[0..min(hlen as usize, 16)].to_vec(),
servername: servername.to_vec(),
bootfilename: bootfilename.to_vec(),
magic: magic.to_vec(),
}
)
)
);
pub fn parse_header(i: &[u8]) -> IResult<&[u8], DHCPHeader> {
let (i, opcode) = be_u8(i)?;
let (i, htype) = be_u8(i)?;
let (i, hlen) = be_u8(i)?;
let (i, hops) = be_u8(i)?;
let (i, txid) = be_u32(i)?;
let (i, seconds) = be_u16(i)?;
let (i, flags) = be_u16(i)?;
let (i, clientip) = take(4_usize)(i)?;
let (i, yourip) = take(4_usize)(i)?;
let (i, serverip) = take(4_usize)(i)?;
let (i, giaddr) = take(4_usize)(i)?;
let (i, clienthw) = take(16_usize)(i)?;
let (i, servername) = take(64_usize)(i)?;
let (i, bootfilename) = take(128_usize)(i)?;
let (i, magic) = take(4_usize)(i)?;
Ok((
i,
DHCPHeader {
opcode: opcode,
htype: htype,
hlen: hlen,
hops: hops,
txid: txid,
seconds: seconds,
flags: flags,
clientip: clientip.to_vec(),
yourip: yourip.to_vec(),
serverip: serverip.to_vec(),
giaddr: giaddr.to_vec(),
clienthw: clienthw[0..min(hlen as usize, 16)].to_vec(),
servername: servername.to_vec(),
bootfilename: bootfilename.to_vec(),
magic: magic.to_vec(),
},
))
}
named!(pub parse_clientid_option<DHCPOption>,
do_parse!(
code: be_u8 >>
len: verify!(be_u8, |&v| v > 1) >>
_htype: be_u8 >>
data: take!(len - 1) >>
(
DHCPOption{
code: code,
data: None,
option: DHCPOptionWrapper::ClientId(DHCPOptClientId{
htype: 1,
data: data.to_vec(),
}),
}
)
)
);
pub fn parse_clientid_option(i: &[u8]) -> IResult<&[u8], DHCPOption> {
let (i, code) = be_u8(i)?;
let (i, len) = verify(be_u8, |&v| v > 1)(i)?;
let (i, _htype) = be_u8(i)?;
let (i, data) = take(len - 1)(i)?;
Ok((
i,
DHCPOption {
code: code,
data: None,
option: DHCPOptionWrapper::ClientId(DHCPOptClientId {
htype: 1,
data: data.to_vec(),
}),
},
))
}
named!(pub parse_address_time_option<DHCPOption>,
do_parse!(
code: be_u8 >>
_len: be_u8 >>
seconds: be_u32 >>
(
DHCPOption{
code: code,
data: None,
option: DHCPOptionWrapper::TimeValue(DHCPOptTimeValue{
seconds: seconds,
}),
}
)
)
);
pub fn parse_address_time_option(i: &[u8]) -> IResult<&[u8], DHCPOption> {
let (i, code) = be_u8(i)?;
let (i, _len) = be_u8(i)?;
let (i, seconds) = be_u32(i)?;
Ok((
i,
DHCPOption {
code: code,
data: None,
option: DHCPOptionWrapper::TimeValue(DHCPOptTimeValue { seconds: seconds }),
},
))
}
named!(pub parse_generic_option<DHCPOption>,
do_parse!(
code: be_u8 >>
len: be_u8 >>
data: take!(len) >> (
DHCPOption{
code: code,
data: None,
option: DHCPOptionWrapper::Generic(DHCPOptGeneric{
data: data.to_vec(),
}),
}
))
);
pub fn parse_generic_option(i: &[u8]) -> IResult<&[u8], DHCPOption> {
let (i, code) = be_u8(i)?;
let (i, len) = be_u8(i)?;
let (i, data) = take(len)(i)?;
Ok((
i,
DHCPOption {
code: code,
data: None,
option: DHCPOptionWrapper::Generic(DHCPOptGeneric {
data: data.to_vec(),
}),
},
))
}
// Parse a single DHCP option. When option 255 (END) is parsed, the remaining
// data will be consumed.
named!(pub parse_option<DHCPOption>,
switch!(peek!(be_u8),
// End of options case. We consume the rest of the data
// so the parse is not called again. But is there a
// better way to "break"?
DHCP_OPT_END => do_parse!(
code: be_u8 >>
data: rest >> (DHCPOption{
code: code,
data: Some(data.to_vec()),
option: DHCPOptionWrapper::End,
})) |
DHCP_OPT_CLIENT_ID => call!(parse_clientid_option) |
DHCP_OPT_ADDRESS_TIME => call!(parse_address_time_option) |
DHCP_OPT_RENEWAL_TIME => call!(parse_address_time_option) |
DHCP_OPT_REBINDING_TIME => call!(parse_address_time_option) |
_ => call!(parse_generic_option)
));
pub fn parse_option(i: &[u8]) -> IResult<&[u8], DHCPOption> {
let (_, opt) = be_u8(i)?;
match opt {
DHCP_OPT_END => {
// End of options case. We consume the rest of the data
// so the parser is not called again. But is there a
// better way to "break"?
let (data, code) = be_u8(i)?;
Ok((
&[],
DHCPOption {
code,
data: Some(data.to_vec()),
option: DHCPOptionWrapper::End,
},
))
}
DHCP_OPT_CLIENT_ID => parse_clientid_option(i),
DHCP_OPT_ADDRESS_TIME => parse_address_time_option(i),
DHCP_OPT_RENEWAL_TIME => parse_address_time_option(i),
DHCP_OPT_REBINDING_TIME => parse_address_time_option(i),
_ => parse_generic_option(i),
}
}
// Parse and return all the options. Upon the end of option indicator
// all the data will be consumed.
named!(pub parse_all_options<Vec<DHCPOption>>, many0!(complete!(call!(parse_option))));
pub fn parse_all_options(i: &[u8]) -> IResult<&[u8], Vec<DHCPOption>> {
many0(complete(parse_option))(i)
}
pub fn dhcp_parse(input: &[u8]) -> IResult<&[u8], DHCPMessage> {
match parse_header(input) {
@ -257,8 +263,10 @@ mod tests {
assert_eq!(header.yourip, &[0, 0, 0, 0]);
assert_eq!(header.serverip, &[0, 0, 0, 0]);
assert_eq!(header.giaddr, &[0, 0, 0, 0]);
assert_eq!(&header.clienthw[..(header.hlen as usize)],
&[0x00, 0x0b, 0x82, 0x01, 0xfc, 0x42]);
assert_eq!(
&header.clienthw[..(header.hlen as usize)],
&[0x00, 0x0b, 0x82, 0x01, 0xfc, 0x42]
);
assert!(header.servername.iter().all(|&x| x == 0));
assert!(header.bootfilename.iter().all(|&x| x == 0));
assert_eq!(header.magic, &[0x63, 0x82, 0x53, 0x63]);
@ -283,37 +291,34 @@ mod tests {
fn test_parse_client_id_too_short() {
// Length field of 0.
let buf: &[u8] = &[
0x01,
0x00, // Length of 0.
0x01,
0x01, // Junk data start here.
0x02,
0x03,
0x01, 0x00, // Length of 0.
0x01, 0x01, // Junk data start here.
0x02, 0x03,
];
let r = parse_clientid_option(buf);
assert!(r.is_err());
// Length field of 1.
let buf: &[u8] = &[
0x01,
0x01, // Length of 1.
0x01,
0x41,
0x01, 0x01, // Length of 1.
0x01, 0x41,
];
let r = parse_clientid_option(buf);
assert!(r.is_err());
// Length field of 2 -- OK.
let buf: &[u8] = &[
0x01,
0x02, // Length of 2.
0x01,
0x41,
0x01, 0x02, // Length of 2.
0x01, 0x41,
];
let r = parse_clientid_option(buf);
match r {
Ok((rem, _)) => { assert_eq!(rem.len(), 0); },
_ => { panic!("failed"); }
Ok((rem, _)) => {
assert_eq!(rem.len(), 0);
}
_ => {
panic!("failed");
}
}
}
}

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