feat: icmp extensions (#33)

Cargo.toml

@@ -74,6 +74,7 @@ windows-sys = { version = "0.48.0", features = [
 ] }
 
 [dev-dependencies]
+hex-literal = "0.4.1"
 rand = "0.8.5"
 test-case = "3.2.1"
 

src/tracing/net/ipv4.rs

@@ -5,6 +5,10 @@ use crate::tracing::net::platform;
 use crate::tracing::net::platform::Socket;
 use crate::tracing::net::socket::TracerSocket as _;
 use crate::tracing::packet::checksum::{icmp_ipv4_checksum, udp_ipv4_checksum};
+use crate::tracing::packet::icmp_extension::extension_header::ExtensionHeader;
+use crate::tracing::packet::icmp_extension::extension_object::ClassNum;
+use crate::tracing::packet::icmp_extension::extension_structure::ExtensionStructure;
+use crate::tracing::packet::icmp_extension::mpls_label_stack::MplsLabelStack;
 use crate::tracing::packet::icmpv4::destination_unreachable::DestinationUnreachablePacket;
 use crate::tracing::packet::icmpv4::echo_reply::EchoReplyPacket;
 use crate::tracing::packet::icmpv4::echo_request::EchoRequestPacket;
@@ -13,7 +17,7 @@ use crate::tracing::packet::icmpv4::{IcmpCode, IcmpPacket, IcmpType};
 use crate::tracing::packet::ipv4::Ipv4Packet;
 use crate::tracing::packet::tcp::TcpPacket;
 use crate::tracing::packet::udp::UdpPacket;
-use crate::tracing::packet::IpProtocol;
+use crate::tracing::packet::{fmt_payload, IpProtocol};
 use crate::tracing::probe::{
  ProbeResponse, ProbeResponseData, ProbeResponseSeq, ProbeResponseSeqIcmp, ProbeResponseSeqTcp,
  ProbeResponseSeqUdp,
@@ -332,14 +336,70 @@ fn extract_probe_resp(
  Ok(match icmp_v4.get_icmp_type() {
  IcmpType::TimeExceeded => {
  let packet = TimeExceededPacket::new_view(icmp_v4.packet()).req()?;
- let resp_seq = extract_probe_resp_seq(packet.payload(), protocol)?;
+ let payload = packet.payload();
+ let extension = packet.extension();
+ if let Some(ext) = extension {
+ let extensions = ExtensionStructure::new_view(ext).req()?;
+ let ext_header = ExtensionHeader::new_view(extensions.header()).req()?;
+ println!(
+ "extension header: version={}, checksum={}",
+ ext_header.get_version(),
+ ext_header.get_checksum()
+ );
+ for obj in extensions.iter() {
+ if obj.get_class_num() == ClassNum::MultiProtocolLabelSwitchingLabelStack {
+ let mpls = MplsLabelStack::new_view(obj.payload()).unwrap();
+ for (i, label) in mpls.iter().enumerate() {
+ println!(
+ "mpls extension object [{}]: label={}, exp={}, bos={}, ttl={}",
+ i,
+ label.get_label(),
+ label.get_exp(),
+ label.get_bos(),
+ label.get_ttl()
+ );
+ }
+ } else {
+ println!("unknown extension object: length={:?}, class_num={:?}, class_subtype={:?}, payload={}", obj.get_length(), obj.get_class_num(), obj.get_class_subtype(), fmt_payload(obj.payload()));
+ }
+ }
+ }
+ let resp_seq = extract_probe_resp_seq(payload, protocol)?;
  Some(ProbeResponse::TimeExceeded(ProbeResponseData::new(
  recv, src, resp_seq,
  )))
  }
  IcmpType::DestinationUnreachable => {
  let packet = DestinationUnreachablePacket::new_view(icmp_v4.packet()).req()?;
- let resp_seq = extract_probe_resp_seq(packet.payload(), protocol)?;
+ let payload = packet.payload();
+ let extension = packet.extension();
+ if let Some(ext) = extension {
+ let extensions = ExtensionStructure::new_view(ext).req()?;
+ let ext_header = ExtensionHeader::new_view(extensions.header()).req()?;
+ println!(
+ "extension header: version={}, checksum={}",
+ ext_header.get_version(),
+ ext_header.get_checksum()
+ );
+ for obj in extensions.iter() {
+ if obj.get_class_num() == ClassNum::MultiProtocolLabelSwitchingLabelStack {
+ let mpls = MplsLabelStack::new_view(obj.payload()).unwrap();
+ for (i, label) in mpls.iter().enumerate() {
+ println!(
+ "mpls extension object [{}]: label={}, exp={}, bos={}, ttl={}",
+ i,
+ label.get_label(),
+ label.get_exp(),
+ label.get_bos(),
+ label.get_ttl()
+ );
+ }
+ } else {
+ println!("unknown extension object: length={:?}, class_num={:?}, class_subtype={:?}, payload={}", obj.get_length(), obj.get_class_num(), obj.get_class_subtype(), fmt_payload(obj.payload()));
+ }
+ }
+ }
+ let resp_seq = extract_probe_resp_seq(payload, protocol)?;
  Some(ProbeResponse::DestinationUnreachable(
  ProbeResponseData::new(recv, src, resp_seq),
  ))

src/tracing/packet.rs

@@ -9,6 +9,9 @@ pub mod icmpv4;
 /// `ICMPv6` packets.
 pub mod icmpv6;
 
+/// ICMP extensions
+pub mod icmp_extension;
+
 /// `IPv4` packets.
 pub mod ipv4;
 
@@ -21,7 +24,8 @@ pub mod udp;
 /// `TCP` packets.
 pub mod tcp;
 
-fn fmt_payload(bytes: &[u8]) -> String {
+#[must_use]
+pub fn fmt_payload(bytes: &[u8]) -> String {
  use itertools::Itertools as _;
  format!("{:02x}", bytes.iter().format(" "))
 }