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use crate::{err::*, *};
/// Slice containing laxly separated IPv4 or IPv6 headers & payload.
///
/// Compared to the normal [`IpSlice`] this slice allows the
/// payload to be incomplete/cut off and errors to be present in
/// the IpPayload.
///
/// The main usecases for "laxly" parsed slices are are:
///
/// * Parsing packets that have been cut off. This is, for example, useful to
/// parse packets returned via ICMP as these usually only contain the start.
/// * Parsing packets where the `total_len` (for IPv4) or `payload_len` (for IPv6)
/// have not yet been set. This can be useful when parsing packets which have
/// been recorded in a layer before the length field was set (e.g. before the
/// operating system set the length fields).
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum LaxIpSlice<'a> {
/// The ipv4 header & the decoded extension headers.
Ipv4(LaxIpv4Slice<'a>),
/// The ipv6 header & the decoded extension headers.
Ipv6(LaxIpv6Slice<'a>),
}
impl<'a> LaxIpSlice<'a> {
/// Returns a reference to the `Ipv4Slice` if `self` is a `IpSlice::Ipv4`.
pub fn ipv4(&self) -> Option<&LaxIpv4Slice> {
use LaxIpSlice::*;
match self {
Ipv4(slice) => Some(slice),
Ipv6(_) => None,
}
}
/// Returns a reference to the `Ipv6Slice` if `self` is a `IpSlice::Ipv6`.
pub fn ipv6(&self) -> Option<&LaxIpv6Slice> {
use LaxIpSlice::*;
match self {
Ipv4(_) => None,
Ipv6(slice) => Some(slice),
}
}
/// Returns true if the payload is fragmented.
pub fn is_fragmenting_payload(&self) -> bool {
match self {
LaxIpSlice::Ipv4(s) => s.is_payload_fragmented(),
LaxIpSlice::Ipv6(s) => s.is_payload_fragmented(),
}
}
/// Return the source address as an std::net::Ipvddr (requires
/// crate feature `std`).
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
pub fn source_addr(&self) -> std::net::IpAddr {
match self {
LaxIpSlice::Ipv4(s) => s.header().source_addr().into(),
LaxIpSlice::Ipv6(s) => s.header().source_addr().into(),
}
}
/// Return the destination address as an std::net::IpAddr (requires
/// crate feature `std`).
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
pub fn destination_addr(&self) -> std::net::IpAddr {
match self {
LaxIpSlice::Ipv4(s) => s.header().destination_addr().into(),
LaxIpSlice::Ipv6(s) => s.header().destination_addr().into(),
}
}
/// Returns a slice containing the data after the IP header
/// and IP extensions headers.
#[inline]
pub fn payload(&self) -> &LaxIpPayloadSlice<'a> {
use LaxIpSlice::*;
match self {
Ipv4(ipv4) => ipv4.payload(),
Ipv6(ipv6) => ipv6.payload(),
}
}
/// Returns the ip number the type of payload of the IP packet.
///
/// This function returns the ip number stored in the last
/// IP header or extension header.
#[inline]
pub fn payload_ip_number(&self) -> IpNumber {
use LaxIpSlice::*;
match self {
Ipv4(ipv4) => ipv4.payload().ip_number,
Ipv6(ipv6) => ipv6.payload().ip_number,
}
}
/// Separates IP headers (include extension headers) & the IP payload from the given slice
/// as far as possible without encountering an error and with less strict length checks.
/// This function is usefull for cut off packet or for packets with unset length fields.
///
/// If you want to only receive correct IpPayloads use [`IpSlice::from_ip_slice`]
/// instead.
///
/// The main usecases for this functions are:
///
/// * Parsing packets that have been cut off. This is, for example, useful to
/// parse packets returned via ICMP as these usually only contain the start.
/// * Parsing packets where the `total_len` (for IPv4) or `payload_length` (for IPv6)
/// have not yet been set. This can be useful when parsing packets which have been
/// recorded in a layer before the length field was set (e.g. before the operating
/// system set the length fields).
///
/// # Differences to `IpSlice::from_slice`:
///
// There are two main differences:
///
/// * Errors in the expansion headers will only stop the parsing and return an `Ok`
/// with the successfully parsed parts and the error as optional. Only if an
/// unrecoverable error is encountered in the IP header itself an `Err` is returned.
/// In the normal `from_slice` function an `Err` is returned if an error is
/// encountered in an exteions header.
/// * `from_slice_lax` ignores inconsistent `total_len` (in IPv4 headers) and
/// inconsistent `payload_length` (in IPv6 headers) values. When these length
/// values in the IP header are inconsistant the length of the given slice is
/// used as a substitute.
///
/// You can check if the slice length was used as a substitude by checking
/// if `result.payload().len_source` is set to [`LenSource::Slice`].
/// If a substitution was not needed `len_source` is set to
/// [`LenSource::Ipv4HeaderTotalLen`] or [`LenSource::Ipv6HeaderPayloadLen`].
///
/// # When is the slice length used as a fallback?
///
/// For IPv4 packets the slice length is used as a fallback/substitude
/// if the `total_length` field in the IPv4 header is:
///
/// * Bigger then the given slice (payload cannot fully be seperated).
/// * Too small to contain at least the IPv4 header.
///
/// For IPv6 packet the slice length is used as a fallback/substitude
/// if the `payload_length` is
///
/// * Bigger then the given slice (payload cannot fully be seperated).
/// * The value `0`.
pub fn from_slice(
slice: &[u8],
) -> Result<
(
LaxIpSlice,
Option<(err::ipv6_exts::HeaderSliceError, err::Layer)>,
),
err::ip::LaxHeaderSliceError,
> {
use crate::ip_number::AUTH;
use err::ip::HeaderError::*;
use err::ip::LaxHeaderSliceError as E;
use err::ipv6_exts::HeaderError as SH;
use err::ipv6_exts::HeaderSliceError as S;
use LaxIpSlice::*;
if slice.is_empty() {
Err(E::Len(err::LenError {
required_len: 1,
len: slice.len(),
len_source: LenSource::Slice,
layer: err::Layer::IpHeader,
layer_start_offset: 0,
}))
} else {
// SAFETY: Safe as slice is not empty.
let first_byte = unsafe { slice.get_unchecked(0) };
match first_byte >> 4 {
4 => {
let ihl = first_byte & 0xf;
// check that the ihl has at least the length of the base IPv4 header
if ihl < 5 {
return Err(E::Content(Ipv4HeaderLengthSmallerThanHeader { ihl }));
}
// check there is enough data for the header
let header_len = (usize::from(ihl)) * 4;
if slice.len() < header_len {
return Err(E::Len(LenError {
required_len: header_len,
len: slice.len(),
len_source: LenSource::Slice,
layer: Layer::Ipv4Header,
layer_start_offset: 0,
}));
}
// SAFETY:
// Safe as the slice length is checked to be at least
// header_len or greater above.
let header = unsafe {
Ipv4HeaderSlice::from_slice_unchecked(core::slice::from_raw_parts(
slice.as_ptr(),
header_len,
))
};
// check the total_lenat least contains the header
let total_len = usize::from(header.total_len());
let (header_payload, len_source, incomplete) = if total_len < header_len {
// fallback to slice len
(
unsafe {
core::slice::from_raw_parts(
// SAFETY: Safe as slice.len() >= header_len was validated
// in a if statement above.
slice.as_ptr().add(header_len),
// SAFETY: Safe as slice.len() >= header_len was validated
// in a if statement above.
slice.len() - header_len,
)
},
LenSource::Slice,
false,
)
} else if slice.len() < total_len {
// fallback to slice len
(
unsafe {
core::slice::from_raw_parts(
// SAFETY: Safe as slice.len() >= header_len was validated
// in a if statement above.
slice.as_ptr().add(header_len),
// SAFETY: Safe as slice.len() >= header_len was validated
// in a if statement above.
slice.len() - header_len,
)
},
LenSource::Slice,
true, // flag payload as incomplete
)
} else {
(
unsafe {
core::slice::from_raw_parts(
// SAFETY: Safe as slice.len() >= header_len was validated
// in a if statement above.
slice.as_ptr().add(header_len),
// SAFETY: Safe as total_length >= header_len was verfied in an
// if statement above as well as that slice.len() >= total_length_usize.
total_len - header_len,
)
},
LenSource::Ipv4HeaderTotalLen,
false,
)
};
// slice extension headers
// decode the authentication header if needed
let fragmented = header.is_fragmenting_payload();
match header.protocol() {
AUTH => {
use crate::err::ip_auth::HeaderSliceError as A;
// parse extension headers
match IpAuthHeaderSlice::from_slice(header_payload) {
Ok(auth) => {
// remove the extension header from the payload
let payload = unsafe {
core::slice::from_raw_parts(
header_payload.as_ptr().add(auth.slice().len()),
header_payload.len() - auth.slice().len(),
)
};
Ok((
Ipv4(LaxIpv4Slice {
header,
exts: Ipv4ExtensionsSlice { auth: Some(auth) },
payload: LaxIpPayloadSlice {
incomplete,
ip_number: auth.next_header(),
fragmented,
len_source,
payload,
},
}),
None,
))
}
Err(err) => {
let ip_number = header.protocol();
Ok((
Ipv4(LaxIpv4Slice {
header,
exts: Ipv4ExtensionsSlice { auth: None },
payload: LaxIpPayloadSlice {
incomplete,
ip_number,
fragmented,
len_source,
payload: header_payload,
},
}),
match err {
A::Len(mut l) => Some((
S::Len({
l.len_source = len_source;
l.add_offset(header.slice().len())
}),
err::Layer::IpAuthHeader,
)),
A::Content(l) => Some((
S::Content(SH::IpAuth(l)),
err::Layer::IpAuthHeader,
)),
},
))
}
}
}
ip_number => Ok((
Ipv4(LaxIpv4Slice {
header,
exts: Ipv4ExtensionsSlice { auth: None },
payload: LaxIpPayloadSlice {
incomplete,
ip_number,
fragmented,
len_source,
payload: header_payload,
},
}),
None,
)),
}
}
6 => {
// check length
if slice.len() < Ipv6Header::LEN {
return Err(E::Len(LenError {
required_len: Ipv6Header::LEN,
len: slice.len(),
len_source: LenSource::Slice,
layer: Layer::Ipv6Header,
layer_start_offset: 0,
}));
}
let header = unsafe {
Ipv6HeaderSlice::from_slice_unchecked(core::slice::from_raw_parts(
slice.as_ptr(),
Ipv6Header::LEN,
))
};
// restrict slice by the length specified in the header (if possible)
let payload_len = usize::from(header.payload_length());
let (header_payload, len_source, incomplete) =
if 0 == payload_len && slice.len() > Ipv6Header::LEN {
// zero set as payload len, assume jumbograms or unitialized
// length and use the slice length as a fallback value
// TODO: Add payload length parsing from the jumbogram for the zero case
(
unsafe {
core::slice::from_raw_parts(
slice.as_ptr().add(Ipv6Header::LEN),
slice.len() - Ipv6Header::LEN,
)
},
LenSource::Slice,
false,
)
} else if slice.len() - Ipv6Header::LEN < payload_len {
// slice is smaller then the assumed payload length
(
unsafe {
core::slice::from_raw_parts(
slice.as_ptr().add(Ipv6Header::LEN),
slice.len() - Ipv6Header::LEN,
)
},
LenSource::Slice,
true, // incomplete
)
} else {
// all good, all data should be here
(
unsafe {
core::slice::from_raw_parts(
slice.as_ptr().add(Ipv6Header::LEN),
payload_len,
)
},
LenSource::Ipv6HeaderPayloadLen,
false,
)
};
// parse extension headers
let (exts, payload_ip_number, payload, mut ext_stop_err) =
Ipv6ExtensionsSlice::from_slice_lax(header.next_header(), header_payload);
// add len offset
if let Some((S::Len(l), _)) = ext_stop_err.as_mut() {
l.len_source = len_source;
l.layer_start_offset += header.header_len();
}
let fragmented = exts.is_fragmenting_payload();
Ok((
Ipv6(LaxIpv6Slice {
header,
exts,
payload: LaxIpPayloadSlice {
incomplete,
ip_number: payload_ip_number,
fragmented,
len_source,
payload,
},
}),
ext_stop_err,
))
}
version_number => Err(E::Content(UnsupportedIpVersion { version_number })),
}
}
}
}
impl<'a> From<LaxIpv4Slice<'a>> for LaxIpSlice<'a> {
fn from(value: LaxIpv4Slice<'a>) -> Self {
LaxIpSlice::Ipv4(value)
}
}
impl<'a> From<LaxIpv6Slice<'a>> for LaxIpSlice<'a> {
fn from(value: LaxIpv6Slice<'a>) -> Self {
LaxIpSlice::Ipv6(value)
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::test_gens::*;
use alloc::{format, vec::Vec};
use proptest::prelude::*;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
#[test]
fn debug_clone_eq() {
// ipv4
{
let mut header: Ipv4Header = Default::default();
header.protocol = ip_number::UDP;
header.set_payload_len(0).unwrap();
let buffer = header.to_bytes();
let ipv4 = LaxIpv4Slice::from_slice(&buffer).unwrap().0;
let slice = LaxIpSlice::Ipv4(ipv4.clone());
// clone & eq
assert_eq!(slice.clone(), slice);
// debug
assert_eq!(format!("{:?}", slice), format!("Ipv4({:?})", ipv4));
}
// ipv6
{
let header = Ipv6Header {
payload_length: 0,
next_header: ip_number::UDP,
..Default::default()
};
let buffer = header.to_bytes();
let ipv6 = LaxIpv6Slice::from_slice(&buffer).unwrap().0;
let slice = LaxIpSlice::Ipv6(ipv6.clone());
// clone & eq
assert_eq!(slice.clone(), slice);
// debug
assert_eq!(format!("{:?}", slice), format!("Ipv6({:?})", ipv6));
}
}
#[test]
fn is_fragmenting_payload() {
for fragment in [false, true] {
use ip_number::UDP;
// ipv4
{
let mut ipv4 = Ipv4Header::new(0, 1, UDP, [3, 4, 5, 6], [7, 8, 9, 10]).unwrap();
if fragment {
ipv4.fragment_offset = 123.try_into().unwrap();
}
let data = ipv4.to_bytes();
let ipv4_slice = LaxIpv4Slice::from_slice(&data).unwrap().0;
assert_eq!(
fragment,
LaxIpSlice::Ipv4(ipv4_slice).is_fragmenting_payload()
);
}
// ipv6
{
let ipv6_frag = Ipv6FragmentHeader {
next_header: UDP,
fragment_offset: IpFragOffset::ZERO,
more_fragments: fragment,
identification: 0,
};
let ipv6 = Ipv6Header {
traffic_class: 0,
flow_label: 1.try_into().unwrap(),
payload_length: ipv6_frag.header_len() as u16,
next_header: ip_number::IPV6_FRAG,
hop_limit: 4,
source: [1; 16],
destination: [2; 16],
};
let mut data = Vec::with_capacity(ipv6.header_len() + ipv6_frag.header_len());
data.extend_from_slice(&ipv6.to_bytes());
data.extend_from_slice(&ipv6_frag.to_bytes());
assert_eq!(
fragment,
LaxIpSlice::Ipv6(LaxIpv6Slice::from_slice(&data).unwrap().0)
.is_fragmenting_payload()
);
}
}
}
#[cfg(feature = "std")]
#[test]
fn source_addr() {
// ipv4
{
let data = Ipv4Header::new(0, 1, 2.into(), [3, 4, 5, 6], [7, 8, 9, 10])
.unwrap()
.to_bytes();
assert_eq!(
IpAddr::V4(Ipv4Addr::from([3, 4, 5, 6])),
LaxIpSlice::Ipv4(LaxIpv4Slice::from_slice(&data[..]).unwrap().0).source_addr()
);
}
// ipv6
{
let data = Ipv6Header {
traffic_class: 0,
flow_label: 1.try_into().unwrap(),
payload_length: 0,
next_header: ip_number::IGMP,
hop_limit: 4,
source: [1; 16],
destination: [2; 16],
}
.to_bytes();
assert_eq!(
IpAddr::V6(Ipv6Addr::from([1; 16])),
LaxIpSlice::Ipv6(LaxIpv6Slice::from_slice(&data[..]).unwrap().0).source_addr()
);
}
}
#[cfg(feature = "std")]
#[test]
fn destination_addr() {
use crate::ip_number::UDP;
// ipv4
{
let data = Ipv4Header::new(0, 1, UDP, [3, 4, 5, 6], [7, 8, 9, 10])
.unwrap()
.to_bytes();
assert_eq!(
IpAddr::V4(Ipv4Addr::from([7, 8, 9, 10])),
LaxIpSlice::Ipv4(LaxIpv4Slice::from_slice(&data[..]).unwrap().0).destination_addr()
);
}
// ipv6
{
let data = Ipv6Header {
traffic_class: 0,
flow_label: 1.try_into().unwrap(),
payload_length: 0,
next_header: ip_number::IGMP,
hop_limit: 4,
source: [1; 16],
destination: [2; 16],
}
.to_bytes();
assert_eq!(
IpAddr::V6(Ipv6Addr::from([2; 16])),
LaxIpSlice::Ipv6(LaxIpv6Slice::from_slice(&data).unwrap().0).destination_addr()
);
}
}
#[test]
fn ip_payload() {
let payload: [u8; 4] = [1, 2, 3, 4];
// ipv4
{
let header = Ipv4Header::new(
payload.len() as u16,
1,
ip_number::UDP,
[3, 4, 5, 6],
[7, 8, 9, 10],
)
.unwrap();
let mut data = Vec::with_capacity(header.header_len() + payload.len());
data.extend_from_slice(&header.to_bytes());
data.extend_from_slice(&payload);
assert_eq!(
LaxIpSlice::Ipv4(LaxIpv4Slice::from_slice(&data[..]).unwrap().0).payload(),
&LaxIpPayloadSlice {
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: header.is_fragmenting_payload(),
len_source: LenSource::Ipv4HeaderTotalLen,
payload: &payload,
}
);
}
// ipv6
{
let header = Ipv6Header {
traffic_class: 0,
flow_label: 1.try_into().unwrap(),
payload_length: payload.len() as u16,
next_header: ip_number::UDP,
hop_limit: 4,
source: [1; 16],
destination: [2; 16],
};
let mut data = Vec::with_capacity(header.header_len() + payload.len());
data.extend_from_slice(&header.to_bytes());
data.extend_from_slice(&payload);
assert_eq!(
LaxIpSlice::Ipv6(LaxIpv6Slice::from_slice(&data[..]).unwrap().0).payload(),
&LaxIpPayloadSlice {
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: false,
len_source: LenSource::Ipv6HeaderPayloadLen,
payload: &payload,
}
);
}
}
#[test]
fn payload_ip_number() {
use crate::ip_number::{IGMP, UDP};
// ipv4
{
let data = Ipv4Header::new(0, 1, UDP, [3, 4, 5, 6], [7, 8, 9, 10])
.unwrap()
.to_bytes();
assert_eq!(
UDP,
LaxIpSlice::Ipv4(LaxIpv4Slice::from_slice(&data[..]).unwrap().0)
.payload_ip_number()
);
}
// ipv6
{
let data = Ipv6Header {
traffic_class: 0,
flow_label: 1.try_into().unwrap(),
payload_length: 0,
next_header: IGMP,
hop_limit: 4,
source: [1; 16],
destination: [2; 16],
}
.to_bytes();
assert_eq!(
IGMP,
LaxIpSlice::Ipv6(LaxIpv6Slice::from_slice(&data).unwrap().0).payload_ip_number()
);
}
}
proptest! {
#[test]
fn from_ip_slice(
ipv4_header in ipv4_any(),
ipv4_exts in ipv4_extensions_with(ip_number::UDP),
ipv6_header in ipv6_any(),
mut ipv6_exts in ipv6_extensions_with(ip_number::UDP)
) {
use err::ip::HeaderError::*;
use err::ip::LaxHeaderSliceError as E;
use err::ipv6_exts::HeaderSliceError as S;
use err::ip_auth::HeaderError::*;
use crate::IpHeaders;
// zero payload
assert_eq!(
LaxIpSlice::from_slice(&[]),
Err(E::Len(LenError{
required_len: 1,
len: 0,
len_source: LenSource::Slice,
layer: Layer::IpHeader,
layer_start_offset: 0,
}))
);
// unknown version number
for bad_version in 0..0xfu8 {
if bad_version != 4 && bad_version != 6 {
assert_eq!(
LaxIpSlice::from_slice(&[bad_version << 4]),
Err(E::Content(UnsupportedIpVersion {
version_number: bad_version,
}))
);
}
}
let payload = [1,2,3,4];
// IPv4
{
// setup header length & fields
let ipv4_header = {
let mut header = ipv4_header;
header.protocol = if ipv4_exts.auth.is_some() {
ip_number::AUTH
} else {
ip_number::UDP
};
header.total_len = (header.header_len() + ipv4_exts.header_len() + payload.len()) as u16;
header.header_checksum = header.calc_header_checksum();
header
};
let ipv4 = IpHeaders::Ipv4(
ipv4_header.clone(),
ipv4_exts.clone()
);
// build packet
let mut buffer = Vec::with_capacity(ipv4.header_len() + payload.len());
ipv4.write(&mut buffer).unwrap();
buffer.extend_from_slice(&payload);
// happy path v4
{
// run test
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
assert!(actual.ipv6().is_none());
let actual = actual.ipv4().unwrap().clone();
assert_eq!(actual.header.to_header(), ipv4_header);
assert_eq!(actual.extensions().to_header(), ipv4_exts);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: ipv4_header.is_fragmenting_payload(),
len_source: LenSource::Ipv4HeaderTotalLen,
payload: &payload
}
);
}
// ihl smaller then 5 error
for bad_ihl in 0..5u8 {
let mut buffer = buffer.clone();
// inject bad IHL
buffer[0] = (buffer[0] & 0xf0u8) | bad_ihl;
assert_eq!(
LaxIpSlice::from_slice(&buffer),
Err(E::Content(Ipv4HeaderLengthSmallerThanHeader { ihl: bad_ihl }))
);
}
// slice smaller then header error
for bad_len in 1..ipv4_header.header_len() {
assert_eq!(
LaxIpSlice::from_slice(&buffer[..bad_len]),
Err(E::Len(LenError{
required_len: ipv4_header.header_len(),
len: bad_len,
len_source: LenSource::Slice,
layer: Layer::Ipv4Header,
layer_start_offset: 0,
}))
);
}
// total len smaller then header
for bad_len in 1..ipv4_header.header_len() {
let mut buffer = buffer.clone();
// inject bad total length
let bad_len_be = (bad_len as u16).to_be_bytes();
buffer[2] = bad_len_be[0];
buffer[3] = bad_len_be[1];
// expect a valid parse with length source "slice"
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
let actual = actual.ipv4().unwrap().clone();
let mut expected_header = ipv4_header.clone();
expected_header.total_len = bad_len as u16;
assert_eq!(actual.header.to_header(), expected_header);
assert_eq!(actual.extensions().to_header(), ipv4_exts);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: ipv4_header.is_fragmenting_payload(),
len_source: LenSource::Slice,
payload: &payload
}
);
}
// total len bigger then slice
{
let bad_len = (buffer.len() + 1) as u16;
let mut buffer = buffer.clone();
// inject bad total length
let bad_len_be = (bad_len as u16).to_be_bytes();
buffer[2] = bad_len_be[0];
buffer[3] = bad_len_be[1];
// expect a valid parse with length source "slice" & incomplete set
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
let actual = actual.ipv4().unwrap().clone();
let mut expected_header = ipv4_header.clone();
expected_header.total_len = bad_len as u16;
assert_eq!(actual.header.to_header(), expected_header);
assert_eq!(actual.extensions().to_header(), ipv4_exts);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: true,
ip_number: ip_number::UDP.into(),
fragmented: ipv4_header.is_fragmenting_payload(),
len_source: LenSource::Slice,
payload: &payload
}
);
}
// auth ext header len error
if ipv4_exts.auth.is_some() {
let bad_len = ipv4_header.header_len() + ipv4_exts.header_len() - 1;
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer[..bad_len]).unwrap();
assert_eq!(
actual_stop_err,
Some((
S::Len(LenError{
required_len: ipv4_exts.header_len(),
len: bad_len - ipv4_header.header_len(),
len_source: LenSource::Slice,
layer: Layer::IpAuthHeader,
layer_start_offset: ipv4_header.header_len(),
}),
Layer::IpAuthHeader
))
);
assert_eq!(actual.ipv4().unwrap().clone().header().to_header(), ipv4_header);
assert_eq!(
actual.payload(),
&LaxIpPayloadSlice{
incomplete: true,
ip_number: ip_number::AUTH,
fragmented: ipv4_header.is_fragmenting_payload(),
len_source: LenSource::Slice,
payload: &buffer[ipv4_header.header_len()..bad_len],
}
);
}
// auth ext header content error
if ipv4_exts.auth.is_some() {
let mut buffer = buffer.clone();
buffer[ipv4_header.header_len() + 1] = 0;
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(
actual_stop_err,
Some((
S::Content(ipv6_exts::HeaderError::IpAuth(ZeroPayloadLen)),
Layer::IpAuthHeader
))
);
assert_eq!(actual.ipv4().unwrap().clone().header().to_header(), ipv4_header);
assert_eq!(
actual.payload(),
&LaxIpPayloadSlice{
incomplete: false,
ip_number: ip_number::AUTH,
fragmented: ipv4_header.is_fragmenting_payload(),
len_source: LenSource::Ipv4HeaderTotalLen,
payload: &buffer[ipv4_header.header_len()..],
}
);
}
}
// IPv6
{
let ipv6_header = {
let mut header = ipv6_header;
header.next_header = ipv6_exts.set_next_headers(ip_number::UDP);
header.payload_length = (ipv6_exts.header_len() + payload.len()) as u16;
header
};
let ipv6 = IpHeaders::Ipv6(
ipv6_header.clone(),
ipv6_exts.clone()
);
// build packet
let mut buffer = Vec::with_capacity(ipv6.header_len() + payload.len());
ipv6.write(&mut buffer).unwrap();
buffer.extend_from_slice(&payload);
// happy path v6
{
// run test
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
assert!(actual.ipv4().is_none());
let actual = actual.ipv6().unwrap().clone();
assert_eq!(actual.header.to_header(), ipv6_header);
assert_eq!(
Ipv6Extensions::from_slice(
ipv6_header.next_header,
actual.extensions().slice()
).unwrap().0,
ipv6_exts
);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: ipv6_exts.is_fragmenting_payload(),
len_source: LenSource::Ipv6HeaderPayloadLen,
payload: &payload
}
);
}
// len error when parsing header
for bad_len in 1..ipv6_header.header_len() {
assert_eq!(
LaxIpSlice::from_slice(&buffer[..bad_len]),
Err(E::Len(LenError{
required_len: ipv6_header.header_len(),
len: bad_len,
len_source: LenSource::Slice,
layer: Layer::Ipv6Header,
layer_start_offset: 0,
}))
);
}
// ipv6 with zero payload length (should fallback to the slice length)
{
let mut buffer = buffer.clone();
// inject 0 as payload len
buffer[4] = 0;
buffer[5] = 0;
// run test
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
let actual = actual.ipv6().unwrap().clone();
let mut expected_header = ipv6_header.clone();
expected_header.payload_length = 0;
assert_eq!(actual.header.to_header(), expected_header);
assert_eq!(
Ipv6Extensions::from_slice(
ipv6_header.next_header,
actual.extensions().slice()
).unwrap().0,
ipv6_exts
);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: false,
ip_number: ip_number::UDP.into(),
fragmented: ipv6_exts.is_fragmenting_payload(),
len_source: LenSource::Slice,
payload: &payload
}
);
}
// payload len bigger then slice
{
let mut buffer = buffer.clone();
// inject 0 as payload len
let bad_payload_len = (buffer.len() - ipv6_header.header_len() + 1) as u16;
let bad_payload_len_be = bad_payload_len.to_be_bytes();
buffer[4] = bad_payload_len_be[0];
buffer[5] = bad_payload_len_be[1];
// run test
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
assert_eq!(None, actual_stop_err);
let actual = actual.ipv6().unwrap().clone();
let mut expected_header = ipv6_header.clone();
expected_header.payload_length = bad_payload_len;
assert_eq!(actual.header.to_header(), expected_header);
assert_eq!(
Ipv6Extensions::from_slice(
ipv6_header.next_header,
actual.extensions().slice()
).unwrap().0,
ipv6_exts
);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: true,
ip_number: ip_number::UDP.into(),
fragmented: ipv6_exts.is_fragmenting_payload(),
len_source: LenSource::Slice,
payload: &payload
}
);
}
// extension length error
if ipv6_exts.hop_by_hop_options.is_some() {
let bad_len = Ipv6Header::LEN + 1;
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer[..bad_len]).unwrap();
let actual = actual.ipv6().unwrap().clone();
assert_eq!(actual.header.to_header(), ipv6_header);
assert_eq!(
actual_stop_err,
Some((
S::Len(LenError{
required_len: 8,
len: bad_len - ipv6_header.header_len(),
len_source: LenSource::Slice,
layer: Layer::Ipv6ExtHeader,
layer_start_offset: ipv6_header.header_len(),
}),
Layer::Ipv6HopByHopHeader
))
);
assert_eq!(
actual.payload,
LaxIpPayloadSlice{
incomplete: true,
ip_number: ip_number::IPV6_HOP_BY_HOP,
fragmented: false, // fragment header will not be able to be read
len_source: LenSource::Slice,
payload: &buffer[ipv6_header.header_len()..bad_len]
}
);
}
// extension content error
if ipv6_exts.auth.is_some() {
// introduce a auth header zero payload error
let mut buffer = buffer.clone();
let auth_offset = ipv6_header.header_len() +
ipv6_exts.hop_by_hop_options.as_ref().map(|h| h.header_len()).unwrap_or(0) +
ipv6_exts.destination_options.as_ref().map(|h| h.header_len()).unwrap_or(0) +
ipv6_exts.routing.as_ref().map(|h| h.routing.header_len()).unwrap_or(0) +
// routing.final_destination_options skiped, as after auth
ipv6_exts.fragment.as_ref().map(|h| h.header_len()).unwrap_or(0);
// inject length zero into auth header (not valid, will
// trigger a content error)
buffer[auth_offset + 1] = 0;
let (actual, actual_stop_err) = LaxIpSlice::from_slice(&buffer).unwrap();
let actual = actual.ipv6().unwrap().clone();
assert_eq!(actual.header.to_header(), ipv6_header);
assert_eq!(
actual_stop_err,
Some((
S::Content(ipv6_exts::HeaderError::IpAuth(ZeroPayloadLen)),
Layer::IpAuthHeader,
))
);
}
}
}
}
proptest! {
#[test]
fn from_ipv4_slice(
ipv4_header in ipv4_unknown()
) {
let mut header = ipv4_header.clone();
header.total_len = (header.header_len() + 4) as u16;
let mut buffer = Vec::with_capacity(header.total_len.into());
buffer.extend_from_slice(&header.to_bytes()[..]);
buffer.extend_from_slice(&[1,2,3,4]);
let s = LaxIpv4Slice::from_slice(&buffer).unwrap().0;
let actual: LaxIpSlice = s.clone().into();
assert_eq!(LaxIpSlice::Ipv4(s), actual);
}
}
proptest! {
#[test]
fn from_ipv6_slice(
ipv6_header in ipv6_unknown()
) {
let mut header = ipv6_header.clone();
header.payload_length = 4;
let mut buffer = Vec::with_capacity(header.header_len() + 4);
buffer.extend_from_slice(&header.to_bytes()[..]);
buffer.extend_from_slice(&[1,2,3,4]);
let s = LaxIpv6Slice::from_slice(&buffer).unwrap().0;
let actual: LaxIpSlice = s.clone().into();
assert_eq!(LaxIpSlice::Ipv6(s), actual);
}
}
}