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//! # DHCPv6
//!
//! This module provides types and utility functions for encoding/decoding a DHCPv4 message.
//!
//! ## Example - constructing messages
//!
//! ```rust
//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
//! use dhcproto::{v6, Encodable, Encoder};
//! // arbitrary DUID
//! let duid = vec![
//! 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,
//! ];
//! // construct a new Message with a random xid
//! let mut msg = v6::Message::new(v6::MessageType::Solicit);
//! // set an option
//! msg.opts_mut()
//! .push(v6::DhcpOption::ClientId(duid));
//!
//! // now encode to bytes
//! let mut buf = Vec::new();
//! let mut e = Encoder::new(&mut buf);
//! msg.encode(&mut e)?;
//!
//! // buf now has the contents of the encoded DHCP message
//! # Ok(()) }
//! ```
//!
//! ## Example - encoding/decoding messages
//!
//! ```rust
//! # fn solicit() -> Vec<u8> {
//! # vec![
//! # 0x01, 0x10, 0x08, 0x74, 0x00, 0x01, 0x00, 0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x39,
//! # 0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x06, 0x00, 0x04, 0x00, 0x17,
//! # 0x00, 0x18, 0x00, 0x08, 0x00, 0x02, 0x00, 0x00, 0x00, 0x19, 0x00, 0x0c, 0x27, 0xfe,
//! # 0x8f, 0x95, 0x00, 0x00, 0x0e, 0x10, 0x00, 0x00, 0x15, 0x18,
//! # ]
//! # }
//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
//! use dhcproto::{v6::Message, Decoder, Decodable, Encoder, Encodable};
//! // example message
//! let solicit = solicit();
//! // decode
//! let msg = Message::decode(&mut Decoder::new(&solicit))?;
//! // now encode
//! let mut buf = Vec::new();
//! let mut e = Encoder::new(&mut buf);
//! msg.encode(&mut e)?;
//!
//! assert_eq!(solicit, buf);
//! # Ok(()) }
//! ```
//!
mod options;
use std::convert::TryInto;
// re-export submodules from proto::msg
pub use self::options::*;
pub use crate::{
decoder::{Decodable, Decoder},
encoder::{Encodable, Encoder},
error::*,
};
/// default dhcpv6 server port
pub const SERVER_PORT: u16 = 547;
/// default dhcpv6 client port
pub const CLIENT_PORT: u16 = 546;
/// See RFC 8415 for updated DHCPv6 info
/// [DHCP for Ipv6](https://datatracker.ietf.org/doc/html/rfc8415)
///
/// All DHCP messages sent between clients and servers share an identical
/// fixed-format header and a variable-format area for options.
///
/// All values in the message header and in options are in network byte
/// order.
///
/// Options are stored serially in the "options" field, with no padding
/// between the options. Options are byte-aligned but are not aligned in
/// any other way (such as on 2-byte or 4-byte boundaries).
///
/// The following diagram illustrates the format of DHCP messages sent
/// between clients and servers:
///
/// ```text
/// 0 1 2 3
/// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/// | msg-type | transaction-id |
/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/// | |
/// . options .
/// . (variable number and length) .
/// | |
/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///
/// msg-type Identifies the DHCP message type; the
/// available message types are listed in
/// Section 7.3. A 1-octet field.
///
/// transaction-id The transaction ID for this message exchange.
/// A 3-octet field.
///
/// options Options carried in this message; options are
/// described in Section 21. A variable-length
/// field (4 octets less than the size of the
/// message).
/// ```
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Message {
/// message type
/// <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
msg_type: MessageType,
/// transaction id
/// trns id must be the same for all messages in a DHCP transaction
/// <https://datatracker.ietf.org/doc/html/rfc8415#section-16.1>
xid: [u8; 3],
/// Options
/// <https://datatracker.ietf.org/doc/html/rfc8415#section-21>
opts: DhcpOptions,
}
impl Default for Message {
fn default() -> Self {
Self {
msg_type: MessageType::Solicit,
xid: rand::random(),
opts: DhcpOptions::new(),
}
}
}
impl Message {
/// returns a new `Message` with a random xid and empty opt section
pub fn new(msg_type: MessageType) -> Self {
Self {
msg_type,
..Self::default()
}
}
/// returns a new `Message` with a given xid and message type and empty opt section
pub fn new_with_id(msg_type: MessageType, xid: [u8; 3]) -> Self {
Self {
msg_type,
xid,
..Self::default()
}
}
/// Get the message's message type.
pub fn msg_type(&self) -> MessageType {
self.msg_type
}
/// Set message type
pub fn set_msg_type(&mut self, msg_type: MessageType) -> &mut Self {
self.msg_type = msg_type;
self
}
/// Get the message's transaction id.
pub fn xid(&self) -> [u8; 3] {
self.xid
}
/// Set transaction id
pub fn set_xid(&mut self, xid: [u8; 3]) -> &mut Self {
self.xid = xid;
self
}
/// Set transaction id from u32, will only use first 3 bytes
pub fn set_xid_num(&mut self, xid: u32) -> &mut Self {
let arr = xid.to_be_bytes();
self.xid = arr[..3]
.try_into()
.expect("a u32 has 4 bytes so this shouldn't fail");
self
}
/// Get a reference to the message's options.
pub fn opts(&self) -> &DhcpOptions {
&self.opts
}
/// Set DHCP opts
pub fn set_opts(&mut self, opts: DhcpOptions) -> &mut Self {
self.opts = opts;
self
}
/// Get a mutable reference to the message's options.
pub fn opts_mut(&mut self) -> &mut DhcpOptions {
&mut self.opts
}
}
/// DHCPv6 message types
/// <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum MessageType {
// RFC 3315
/// client solicit - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Solicit,
/// server advertise - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Advertise,
/// request - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Request,
/// confirm - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Confirm,
/// renew - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Renew,
/// rebind - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Rebind,
/// reply - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Reply,
/// release message type - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Release,
/// decline - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Decline,
/// reconfigure - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
Reconfigure,
/// information request - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
InformationRequest,
/// relay forward - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
RelayForw,
/// relay reply - <https://datatracker.ietf.org/doc/html/rfc8415#section-7.3>
RelayRepl,
// RFC 5007
/// lease query - <https://datatracker.ietf.org/doc/html/rfc5007#section-4.2.1>
LeaseQuery,
/// lease query reply - <https://datatracker.ietf.org/doc/html/rfc5007#section-4.2.2>
LeaseQueryReply,
// RFC 5460
/// lease query done - <https://datatracker.ietf.org/doc/html/rfc5460#section-5.2.2>
LeaseQueryDone,
/// lease query data - <https://datatracker.ietf.org/doc/html/rfc5460#section-5.2.1>
LeaseQueryData,
// RFC 6977
/// reconfigure request - <https://datatracker.ietf.org/doc/html/rfc6977#section-6.2.1>
ReconfigureRequest,
/// reconfigure reply - <https://datatracker.ietf.org/doc/html/rfc6977#section-6.2.2>
ReconfigureReply,
// RFC 7341
/// dhcpv4 query - <https://datatracker.ietf.org/doc/html/rfc7341#section-6.2>
DHCPv4Query,
/// dhcpv4 response - <https://datatracker.ietf.org/doc/html/rfc7341#section-6.2>
DHCPv4Response,
/// unknown/unimplemented message type
Unknown(u8),
}
impl From<u8> for MessageType {
fn from(n: u8) -> Self {
use MessageType::*;
match n {
// RFC 3315
1 => Solicit,
2 => Advertise,
3 => Request,
4 => Confirm,
5 => Renew,
6 => Rebind,
7 => Reply,
8 => Release,
9 => Decline,
10 => Reconfigure,
11 => InformationRequest,
12 => RelayForw,
13 => RelayRepl,
// RFC 5007
14 => LeaseQuery,
15 => LeaseQueryReply,
// RFC 5460
16 => LeaseQueryDone,
17 => LeaseQueryData,
// RFC 6977
18 => ReconfigureRequest,
19 => ReconfigureReply,
// RFC 7341
20 => DHCPv4Query,
21 => DHCPv4Response,
n => Unknown(n),
}
}
}
impl From<MessageType> for u8 {
fn from(m: MessageType) -> Self {
use MessageType::*;
match m {
// RFC 3315
Solicit => 1,
Advertise => 2,
Request => 3,
Confirm => 4,
Renew => 5,
Rebind => 6,
Reply => 7,
Release => 8,
Decline => 9,
Reconfigure => 10,
InformationRequest => 11,
RelayForw => 12,
RelayRepl => 13,
// RFC 5007
LeaseQuery => 14,
LeaseQueryReply => 15,
// RFC 5460
LeaseQueryDone => 16,
LeaseQueryData => 17,
// RFC 6977
ReconfigureRequest => 18,
ReconfigureReply => 19,
// RFC 7341
DHCPv4Query => 20,
DHCPv4Response => 21,
Unknown(n) => n,
}
}
}
impl Decodable for Message {
fn decode(decoder: &mut Decoder<'_>) -> DecodeResult<Self> {
Ok(Message {
msg_type: decoder.read_u8()?.into(),
xid: decoder.read::<3>()?,
opts: DhcpOptions::decode(decoder)?,
})
}
}
impl Encodable for Message {
fn encode(&self, e: &mut Encoder<'_>) -> EncodeResult<()> {
e.write_u8(self.msg_type.into())?;
e.write(self.xid)?;
self.opts.encode(e)?;
Ok(())
}
}
#[cfg(test)]
mod tests {
use super::*;
type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
fn decode_ipv6(input: Vec<u8>, mtype: MessageType) -> Result<()> {
// decode
let msg = Message::decode(&mut Decoder::new(&input))?;
dbg!(&msg);
assert_eq!(mtype, msg.msg_type);
// now encode
let mut buf = Vec::new();
let mut e = Encoder::new(&mut buf);
msg.encode(&mut e)?;
println!("{:?}", buf);
println!("{:?}", input);
// no PAD bytes or hashmap with ipv6 so the lens will be exact
assert_eq!(buf.len(), input.len());
assert_eq!(buf, input);
// decode again
let res = Message::decode(&mut Decoder::new(&buf))?;
// check Messages are equal after decoding/encoding
assert_eq!(msg, res);
Ok(())
}
#[test]
fn decode_solicit() -> Result<()> {
decode_ipv6(solicit(), MessageType::Solicit)?;
Ok(())
}
#[test]
fn decode_advertise() -> Result<()> {
decode_ipv6(advertise(), MessageType::Advertise)?;
Ok(())
}
#[test]
fn decode_request() -> Result<()> {
decode_ipv6(request(), MessageType::Request)?;
Ok(())
}
#[test]
fn decode_reply() -> Result<()> {
decode_ipv6(reply(), MessageType::Reply)?;
Ok(())
}
fn solicit() -> Vec<u8> {
vec![
0x01, 0x10, 0x08, 0x74, 0x00, 0x01, 0x00, 0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x39,
0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x06, 0x00, 0x04, 0x00, 0x17,
0x00, 0x18, 0x00, 0x08, 0x00, 0x02, 0x00, 0x00, 0x00, 0x19, 0x00, 0x0c, 0x27, 0xfe,
0x8f, 0x95, 0x00, 0x00, 0x0e, 0x10, 0x00, 0x00, 0x15, 0x18,
]
}
fn advertise() -> Vec<u8> {
vec![
0x02, 0x10, 0x08, 0x74, 0x00, 0x19, 0x00, 0x29, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1a, 0x00, 0x19, 0x00, 0x00, 0x11, 0x94,
0x00, 0x00, 0x1c, 0x20, 0x40, 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x0e, 0x00, 0x01, 0x00,
0x01, 0x1c, 0x39, 0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x02, 0x00,
0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x38, 0x25, 0xe8, 0x08, 0x00, 0x27, 0xd4, 0x10,
0xbb,
]
}
fn request() -> Vec<u8> {
vec![
0x03, 0x49, 0x17, 0x4e, 0x00, 0x01, 0x00, 0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x39,
0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x02, 0x00, 0x0e, 0x00, 0x01,
0x00, 0x01, 0x1c, 0x38, 0x25, 0xe8, 0x08, 0x00, 0x27, 0xd4, 0x10, 0xbb, 0x00, 0x06,
0x00, 0x04, 0x00, 0x17, 0x00, 0x18, 0x00, 0x08, 0x00, 0x02, 0x00, 0x00, 0x00, 0x19,
0x00, 0x29, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x00, 0x0e, 0x10, 0x00, 0x00, 0x15, 0x18,
0x00, 0x1a, 0x00, 0x19, 0x00, 0x00, 0x1c, 0x20, 0x00, 0x00, 0x1d, 0x4c, 0x40, 0x20,
0x01, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00,
]
}
fn reply() -> Vec<u8> {
vec![
0x07, 0x49, 0x17, 0x4e, 0x00, 0x19, 0x00, 0x29, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1a, 0x00, 0x19, 0x00, 0x00, 0x11, 0x94,
0x00, 0x00, 0x1c, 0x20, 0x40, 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x0e, 0x00, 0x01, 0x00,
0x01, 0x1c, 0x39, 0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x02, 0x00,
0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x38, 0x25, 0xe8, 0x08, 0x00, 0x27, 0xd4, 0x10,
0xbb,
]
}
}