Merge pull request #3 from junderw/junderw/minor-fixes

Some minor fixes.
This commit is contained in:
pj1234678
2023-10-30 20:54:00 -07:00
committed by GitHub
7 changed files with 132 additions and 169 deletions

2
.gitignore vendored Normal file
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@@ -0,0 +1,2 @@
/target
Cargo.lock

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@@ -8,6 +8,7 @@ fn main() {
server::Server::serve(
UdpSocket::bind("0.0.0.0:67").unwrap(),
Ipv4Addr::new(0, 0, 0, 0),
Ipv4Addr::new(0, 0, 0, 0),
MyServer {},
);
}
@@ -24,7 +25,9 @@ impl server::Handler for MyServer {
};
println!(
"{}\t{}\t{}\tOnline",
time::OffsetDateTime::now_local().format("%Y-%m-%dT%H:%M:%S"),
time::OffsetDateTime::try_now_local()
.unwrap()
.format("%Y-%m-%dT%H:%M:%S"),
chaddr(&in_packet.chaddr),
Ipv4Addr::from(req_ip)
);

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@@ -1,12 +1,9 @@
#[macro_use(u32_bytes, bytes_u32)]
extern crate dhcp4r;
use std::collections::HashMap;
use std::fs::File;
use std::io::{BufRead, BufReader};
use std::net::{Ipv4Addr, UdpSocket};
use std::ops::Add;
use std::time::{Duration, Instant};
use std::fs::File;
use std::io::{BufRead, BufReader};
use dhcp4r::{options, packet, server};
@@ -24,10 +21,9 @@ const LEASE_DURATION_SECS: u32 = 86400;
const LEASE_NUM: u32 = 252;
// Derived constants
const IP_START_NUM: u32 = bytes_u32!(IP_START);
const IP_START_NUM: u32 = u32::from_be_bytes(IP_START);
const INFINITE_LEASE: Option<Instant> = None; // Special value for infinite lease
fn main() {
let socket = UdpSocket::bind("0.0.0.0:67").unwrap();
socket.set_broadcast(true).unwrap();
@@ -79,7 +75,6 @@ impl server::Handler for MyServer {
fn handle_request(&mut self, server: &server::Server, in_packet: packet::Packet) {
match in_packet.message_type() {
Ok(options::MessageType::Discover) => {
// Otherwise prefer existing (including expired if available)
if let Some(ip) = self.current_lease(&in_packet.chaddr) {
println!("Sending Reply to discover");
@@ -129,7 +124,13 @@ impl server::Handler for MyServer {
nak(server, in_packet, "Requested IP not available");
return;
}
self.leases.insert(req_ip, (in_packet.chaddr, Some(Instant::now().add(self.lease_duration))));
self.leases.insert(
req_ip,
(
in_packet.chaddr,
Some(Instant::now().add(self.lease_duration)),
),
);
println!("Sending Reply to Request");
reply(server, options::MessageType::Ack, in_packet, &req_ip);
}
@@ -163,7 +164,6 @@ impl MyServer {
}
}
fn current_lease(&self, chaddr: &[u8; 6]) -> Option<Ipv4Addr> {
for (i, v) in &self.leases {
if v.0 == *chaddr {
return Some(*i);

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@@ -1,33 +1,7 @@
pub mod options;
pub mod packet;
pub mod server;
/// Converts a u32 to 4 bytes (Big endian)
#[macro_export]
macro_rules! u32_bytes {
( $x:expr ) => {
[
($x >> 24) as u8,
($x >> 16) as u8,
($x >> 8) as u8,
$x as u8,
]
};
}
/// Converts 4 bytes to a u32 (Big endian)
#[macro_export]
macro_rules! bytes_u32 {
( $x:expr ) => {
($x[0] as u32) * (1 << 24)
+ ($x[1] as u32) * (1 << 16)
+ ($x[2] as u32) * (1 << 8)
+ ($x[3] as u32)
};
}
#[cfg(test)]
mod tests {
#[test]

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@@ -19,8 +19,6 @@ pub enum ErrorKind {
type IResult<I, O> = Result<(I, O), CustomErr<I>>;
/// DHCP Packet Structure
#[derive(Debug)]
pub struct Packet {
@@ -87,10 +85,12 @@ pub fn decode_option(input: &[u8]) -> IResult<&[u8], DhcpOption> {
let (input, len) = custom_be_u8(input)?;
let (input, data) = custom_take(len.into())(input)?;
let option = match code {
DHCP_MESSAGE_TYPE => DhcpOption::DhcpMessageType(match MessageType::from(custom_be_u8(data)?.1) {
DHCP_MESSAGE_TYPE => {
DhcpOption::DhcpMessageType(match MessageType::from(custom_be_u8(data)?.1) {
Ok(x) => x,
Err(_) => return Err(CustomErr::UnrecognizedMessageType),
}),
})
}
SERVER_IDENTIFIER => DhcpOption::ServerIdentifier(decode_ipv4(data)?.1),
PARAMETER_REQUEST_LIST => DhcpOption::ParameterRequestList(data.to_vec()),
REQUESTED_IP_ADDRESS => DhcpOption::RequestedIpAddress(decode_ipv4(data)?.1),
@@ -133,7 +133,7 @@ fn custom_tag<'a>(tag: &'static [u8]) -> impl Fn(&'a [u8]) -> IResult<&'a [u8],
}
}
fn custom_be_u8(input: &[u8]) -> IResult<&[u8], u8> {
if input.len() < 1 {
if input.is_empty() {
return Err(CustomErr::InvalidHlen);
}
@@ -174,7 +174,6 @@ fn decode(input: &[u8]) -> IResult<&[u8], Packet> {
let (input, giaddr) = decode_ipv4(input)?;
if hlen != 6 {
return Err(CustomErr::InvalidHlen);
}
let (_, chaddr) = custom_take(6usize)(input)?;
@@ -182,22 +181,16 @@ fn decode(input: &[u8]) -> IResult<&[u8], Packet> {
let input = options_input;
let (input, _) = custom_tag(&COOKIE)(input)?;
let mut options = Vec::new();
let mut rest = input;
loop {
match decode_option(rest) {
Ok((new_rest, option)) => {
while let Ok((new_rest, option)) = decode_option(rest) {
rest = new_rest;
options.push(option);
if rest.starts_with(&[END]) {
break;
}
}
Err(_) => break,
}
}
let input = rest.split_at(1).1; // Skip the END tag byte
@@ -223,18 +216,12 @@ fn decode(input: &[u8]) -> IResult<&[u8], Packet> {
impl Packet {
pub fn from(input: &[u8]) -> Result<Packet, CustomErr<&[u8]>> {
Ok(decode(input)?.1)
}
/// Extracts requested option payload from packet if available
pub fn option(&self, code: u8) -> Option<&DhcpOption> {
for option in &self.options {
if option.code() == code {
return Some(&option);
}
}
None
self.options.iter().find(|&option| option.code() == code)
}
/// Convenience function for extracting a packet's message type.

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@@ -1,3 +1,5 @@
//! This is a convenience module that simplifies the writing of a DHCP server service.
use std::cell::Cell;
use std::net::{IpAddr, Ipv4Addr, SocketAddr, UdpSocket};
@@ -5,8 +7,6 @@ use crate::options;
use crate::options::{DhcpOption, MessageType};
use crate::packet::*;
///! This is a convenience module that simplifies the writing of a DHCP server service.
pub struct Server {
out_buf: Cell<[u8; 1500]>,
socket: UdpSocket,
@@ -22,12 +22,12 @@ pub trait Handler {
pub fn filter_options_by_req(opts: &mut Vec<DhcpOption>, req_params: &[u8]) {
let mut pos = 0;
let h = &[
options::DHCP_MESSAGE_TYPE as u8,
options::SERVER_IDENTIFIER as u8,
options::SUBNET_MASK as u8,
options::IP_ADDRESS_LEASE_TIME as u8,
options::DOMAIN_NAME_SERVER as u8,
options::ROUTER as u8,
options::DHCP_MESSAGE_TYPE,
options::SERVER_IDENTIFIER,
options::SUBNET_MASK,
options::IP_ADDRESS_LEASE_TIME,
options::DOMAIN_NAME_SERVER,
options::ROUTER,
] as &[u8];
// Process options from req_params
@@ -84,7 +84,6 @@ impl Server {
server_ip,
broadcast_ip,
src: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0),
};
loop {
match s.socket.recv_from(&mut in_buf) {
@@ -133,7 +132,7 @@ impl Server {
if let Some(DhcpOption::ParameterRequestList(prl)) =
req_packet.option(options::PARAMETER_REQUEST_LIST)
{
filter_options_by_req(&mut opts, &prl);
filter_options_by_req(&mut opts, prl);
}
self.send(Packet {
@@ -154,9 +153,7 @@ impl Server {
/// Checks the packet see if it was intended for this DHCP server (as opposed to some other also on the network).
pub fn for_this_server(&self, packet: &Packet) -> bool {
match packet.option(options::SERVER_IDENTIFIER) {
Some(DhcpOption::ServerIdentifier(x)) => {
x == &self.server_ip
},
Some(DhcpOption::ServerIdentifier(x)) => x == &self.server_ip,
_ => false,
}
}