dhcparse

A zero-copy DHCPv4 parser.

This crate is especially suitable for writing DHCP relay agents, which only need to read and write a few fields, set and possibly remove a couple of options, before forwarding an incoming DHCP message.

Examples

Basic usage:

```rust use dhcparse::{v4_options, dhcpv4::{Message, MessageType}}; use std::net::Ipv4Addr;

let mut msg = Message::new(EXAMPLEDISCOVERMSG)?;

// Read a field assert_eq!(msg.chaddr()?, [0x01, 0x02, 0x03, 0x04, 0x05, 0x06]);

// Set a field *msg.giaddr_mut() = Ipv4Addr::new(192, 168, 1, 50).into();

// Parse a set of options asserteq!( v4options!(msg; MessageType required, ServerIdentifier, RequestedIpAddress)?, ( MessageType::DISCOVER, None, Some(&Ipv4Addr::new(192, 168, 1, 100).into()) ) ); ```

Constructing a new message:

```rust use dhcparse::dhcpv4::{DhcpOption, Encode as , Encoder, Message, MessageType, OpCode}; // Create a copy of an empty message with the message type option added let mut msg = Encoder .appendoption(DhcpOption::MessageType(MessageType::DISCOVER)) .encodetoowned(&Message::default())?; msg.set_op(OpCode::BootRequest);

assert_eq!(msg.options()?.count(), 1); ```

Related projects

• [dhcproto] is another Rust crate that instead parses DHCP messages into an owned representation. This may be more convenient for some applications, but comes with the overhead of copying and heap allocations. For instance, the current set of dhcproto benchmarks would be no-ops with dhcparse.