cleaning dhcp

Cargo.lock

@@ -326,6 +326,18 @@ dependencies = [
  "defmt",
 ]
 
+[[package]]
+name = "dhcparse"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c1b7bc252945fef54ffa028dec6a3fcf7b1931968f4db476c93d0eab0d92d62"
+dependencies = [
+ "bitflags 1.3.2",
+ "byteorder",
+ "memchr",
+ "ref-cast",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1080,6 +1092,7 @@ dependencies = [
  "cyw43-pio",
  "defmt",
  "defmt-rtt",
+ "dhcparse",
  "embassy-executor",
  "embassy-net",
  "embassy-rp",
@@ -1226,6 +1239,26 @@ dependencies = [
  "bitflags 2.9.0",
 ]
 
+[[package]]
+name = "ref-cast"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a0ae411dbe946a674d89546582cea4ba2bb8defac896622d6496f14c23ba5cf"
+dependencies = [
+ "ref-cast-impl",
+]
+
+[[package]]
+name = "ref-cast-impl"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1165225c21bff1f3bbce98f5a1f889949bc902d3575308cc7b0de30b4f6d27c7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.100",
+]
+
 [[package]]
 name = "regex"
 version = "1.11.1"

Cargo.toml

@@ -4,8 +4,12 @@ version = "0.1.0"
 edition = "2024"
 
 [features]
-wifi-connect = ["dep:serde-json-core", "dep:serde"] # you need to add a wifi.conf file with your wifi credentials (for example : "Example Wifi name:pa$$w0rd")
-default = ["wifi-connect"]
+wifi-connect = [
+    "dep:serde-json-core",
+    "dep:serde",
+] # you need to add a wifi.conf file for this to work
+dhcp = ["dep:dhcparse"]
+default = ["dhcp"]
 
 [dependencies]
 embassy-executor = { git = "https://github.com/embassy-rs/embassy", features = [
@@ -22,19 +26,17 @@ embassy-rp = { git = "https://github.com/embassy-rs/embassy", features = [
     "time-driver",
     "critical-section-impl",
 ] }
-embassy-time = {git = "https://github.com/embassy-rs/embassy"}
-embassy-usb-logger = {git = "https://github.com/embassy-rs/embassy"}
+embassy-time = { git = "https://github.com/embassy-rs/embassy" }
+embassy-usb-logger = { git = "https://github.com/embassy-rs/embassy" }
 embassy-net = { git = "https://github.com/embassy-rs/embassy", features = [
     "defmt",
     "proto-ipv4",
     "tcp",
+    "udp",
     "dhcpv4",
-    # "dns",
-    # "icmp",
-    "packet-trace"
 ] }
-cyw43-pio = {git = "https://github.com/embassy-rs/embassy"}
-cyw43 = {git = "https://github.com/embassy-rs/embassy"}
+cyw43-pio = { git = "https://github.com/embassy-rs/embassy" }
+cyw43 = { git = "https://github.com/embassy-rs/embassy" }
 
 embedded-io-async = "*"
 defmt = "*"
@@ -48,5 +50,8 @@ heapless = "*"
 rand_core = "*"
 
 log = "*"
-serde-json-core = {version = "*", optional = true}
-serde = {version = "*", optional = true, default-features = false, features = ["derive"]}
+serde-json-core = { version = "*", optional = true }
+serde = { version = "*", optional = true, default-features = false, features = [
+    "derive",
+] }
+dhcparse = { version = "*", default-features = false, optional = true }

src/dhcp.rs

@@ -0,0 +1,173 @@
+use core::net::Ipv4Addr;
+
+use dhcparse::{
+    dhcpv4::{self, DhcpOption, MessageType as DhcpMsgType},
+    v4_options,
+};
+use embassy_net::{
+    IpEndpoint, Stack,
+    udp::{PacketMetadata, UdpMetadata, UdpSocket},
+};
+use embassy_time::Timer;
+use heapless::Vec;
+use log::{info, warn};
+use pico_website::unwrap;
+
+#[embassy_executor::task(pool_size = 1)]
+pub async fn dhcp_server(stack: Stack<'static>) {
+    let mut rx_buffer = [0; 4096];
+    let mut tx_buffer = [0; 4096];
+    let mut rx_meta = [PacketMetadata::EMPTY; 16];
+    let mut tx_meta = [PacketMetadata::EMPTY; 16];
+    let mut buf = [0; 4096];
+    let mut res_buf = Vec::<u8, 4096>::new();
+    let mut opts = Vec::<u8, 255>::new();
+    let mut current_ip = 10_u8; // add one at each new connection, loop at 250, hope not to get on occupied ip
+
+    'listen: loop {
+        let mut socket = UdpSocket::new(
+            stack,
+            &mut rx_meta,
+            &mut rx_buffer,
+            &mut tx_meta,
+            &mut tx_buffer,
+        );
+        unwrap(socket.bind(67)).await;
+
+        info!("Starting DHCP server");
+        loop {
+            let (n, _) = unwrap(socket.recv_from(&mut buf).await).await;
+
+            let msg = unwrap(dhcpv4::Message::new(&buf[..n])).await;
+
+            let msg_type = unwrap(v4_options!(msg; MessageType required)).await;
+            let mut rapid_commit = false;
+            if unwrap(msg.options())
+                .await
+                .any(|opt| matches!(opt, Ok((DhcpOption::Unknown(80, _), _))))
+            {
+                if msg_type != DhcpMsgType::DISCOVER {
+                    warn!("WARN : dhcp rapid commit option on {:?} message", msg_type);
+                    continue 'listen;
+                }
+                rapid_commit = true;
+            }
+            info!("Dhcp: received {:?} message", msg_type);
+            Timer::after_secs(0).await;
+
+            match msg_type {
+                DhcpMsgType::DISCOVER | DhcpMsgType::REQUEST => {
+                    res_buf.clear();
+                    res_buf.push(2).unwrap(); // op
+                    res_buf.push(1).unwrap(); // htype
+                    res_buf.push(6).unwrap(); // hlen
+                    res_buf.push(0).unwrap(); // hops
+                    res_buf.extend_from_slice(&buf[4..8]).unwrap(); // xid
+                    res_buf.extend_from_slice(&[0; 2]).unwrap(); // secs
+                    res_buf.extend_from_slice(&[0x80, 0x00]).unwrap(); // flags
+                    res_buf.extend_from_slice(&buf[12..16]).unwrap(); // ciaddr
+                    res_buf
+                        .extend_from_slice(&[192, 254, 0, current_ip])
+                        .unwrap(); // yiaddr
+                    res_buf.extend_from_slice(&[0; 4]).unwrap(); // siaddr
+                    res_buf.extend_from_slice(&buf[24..28]).unwrap(); // giaddr
+                    res_buf.extend_from_slice(&buf[28..44]).unwrap(); // chaddr
+                    res_buf.extend_from_slice(&[0; 192]).unwrap(); // sname/file
+                    res_buf.extend_from_slice(&[99, 130, 83, 99]).unwrap(); // magic cookie
+
+                    res_buf
+                        .extend_from_slice(&[
+                            53,
+                            1,
+                            match (msg_type, rapid_commit) {
+                                (DhcpMsgType::DISCOVER, false) => 2, // DHCP_OFFER
+                                _ => 5,                              // DHCP_ACK
+                            },
+                        ])
+                        .unwrap(); // opt message type
+
+                    opts.clear();
+                    opts.extend_from_slice(
+                        unwrap(v4_options!(msg; ParameterRequestList))
+                            .await
+                            .unwrap_or(&[]),
+                    )
+                    .unwrap();
+
+                    let default_opts: &[u8] = match (msg_type, rapid_commit) {
+                        (DhcpMsgType::DISCOVER, false) => &[54],
+                        (DhcpMsgType::DISCOVER, true) => &[54, 80],
+                        (DhcpMsgType::REQUEST, false) => &[1, 3, 51, 6, 54],
+                        _ => unreachable!(),
+                    };
+                    for o in default_opts {
+                        if !opts.contains(o) {
+                            opts.push(*o).unwrap();
+                        }
+                    }
+
+                    unwrap(write_dhcp_opts(&mut res_buf, &opts).await).await;
+                    res_buf.push(255).unwrap(); // end option
+
+                    unwrap(
+                        socket
+                            .send_to(
+                                &res_buf,
+                                UdpMetadata {
+                                    endpoint: IpEndpoint::new(
+                                        Ipv4Addr::new(255, 255, 255, 255).into(),
+                                        68,
+                                    ),
+                                    local_address: Some(Ipv4Addr::new(192, 254, 0, 2).into()),
+                                    meta: Default::default(),
+                                },
+                            )
+                            .await,
+                    )
+                    .await;
+                    info!("Dhcp: offer/ack sent for ip 192.254.0.{}", current_ip);
+                    Timer::after_secs(0).await;
+
+                    if msg_type == DhcpMsgType::REQUEST || rapid_commit {
+                        current_ip += 1;
+                        if current_ip > 250 {
+                            current_ip = 10;
+                        }
+                    }
+                }
+                _ => {}
+            }
+
+            // unwrap(socket.send_to(&buf[..n], ep).await).await;
+        }
+    }
+}
+
+async fn write_dhcp_opts<const N: usize>(buf: &mut Vec<u8, N>, op_codes: &[u8]) -> Result<(), ()> {
+    for o in op_codes {
+        let (opt_len, opt): (u8, &[u8]) = match o {
+            1 => (4, &[255, 255, 255, 0]), // DhcpOption::SubnetMask(&dhcpv4::Addr([255, 255, 255, 0])),
+            2 => (4, &3600_i32.to_be_bytes()), // DhcpOption::TimeOffset(3600),
+            3 => (4, &[192, 254, 0, 2]),   // DhcpOption::Router(&[dhcpv4::Addr([192, 254, 0, 2])]),
+            6 => (4, &[0, 0, 0, 0]), // DhcpOption::DomainNameServer(&[dhcpv4::Addr([0, 0, 0, 0])]),
+            12 => (4, b"blue"),      // DhcpOption::HostName(b"blue"),
+            15 => (11, b"LocalDomain"), // DhcpOption::DomainName(b"LocalDomain"),
+            26 => (2, &1514_u16.to_be_bytes()), // DhcpOption::Unknown(26, &[0x5, 0xEA]), // mtu
+            28 => (4, &[192, 254, 0, 255]), // DhcpOption::Unknown(28, &[192, 254, 0, 255]), // broadcast
+            51 => (4, &700_u32.to_be_bytes()), // DhcpOption::AddressLeaseTime(700),
+            54 => (4, &[192, 254, 0, 2]), // DhcpOption::ServerIdentifier(&dhcpv4::Addr([192, 254, 0, 2])),
+            58 => (4, &500_u32.to_be_bytes()), // DhcpOption::Unknown(58, &[0, 0, 0x1, 0xF4]), // renewal time = 500s
+            59 => (4, &600_u32.to_be_bytes()), // DhcpOption::Unknown(59, &[0, 0, 0x2, 0x58]), // rebinding time = 600s
+            80 => (0, &[]),
+            _ => {
+                info!("Dhcp: unhandled requested option {}", o);
+                Timer::after_secs(0).await;
+                continue;
+            }
+        };
+        buf.push(*o).map_err(|_| ())?;
+        buf.push(opt_len).map_err(|_| ())?;
+        buf.extend_from_slice(opt)?;
+    }
+    Ok(())
+}

src/lib.rs

@@ -2,15 +2,16 @@
 
 use core::fmt::Debug;
 use embassy_time::Timer;
-use log::error;
+use log::info;
 
 pub async fn unwrap<T, E: Debug>(res: Result<T, E>) -> T {
     match res {
         Ok(v) => v,
         Err(e) => {
-            error!("FATAL ERROR : {:?}", e);
+            info!("FATAL ERROR : {:?}", e);
             loop {
-                Timer::after_millis(0).await;
+                info!("FATAL ERROR : {:?}", e);
+                Timer::after_secs(5).await;
             }
         }
     }

src/main.rs

@@ -4,10 +4,9 @@
 #![feature(impl_trait_in_assoc_type)]
 #![feature(slice_split_once)]
 
-use core::net::Ipv4Addr;
 use cyw43_pio::{DEFAULT_CLOCK_DIVIDER, PioSpi};
 use embassy_executor::Spawner;
-use embassy_net::{Config, DhcpConfig, StackResources};
+use embassy_net::{Config, StackResources};
 use embassy_rp::bind_interrupts;
 use embassy_rp::clocks::RoscRng;
 use embassy_rp::gpio::{Level, Output};
@@ -15,14 +14,16 @@ use embassy_rp::peripherals::USB;
 use embassy_rp::peripherals::{DMA_CH0, PIO0};
 use embassy_rp::pio::{InterruptHandler as PioInterruptHandler, Pio};
 use embassy_rp::usb::{Driver, InterruptHandler as UsbInterruptHandler};
-use log::info;
+use pico_website::unwrap;
 use rand_core::RngCore;
 use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
-use pico_website::unwrap;
 
-mod socket;
+#[cfg(feature = "dhcp")]
+mod dhcp;
+
 mod game;
+mod socket;
 
 bind_interrupts!(struct Irqs {
     USBCTRL_IRQ => UsbInterruptHandler<USB>;
@@ -82,26 +83,31 @@ async fn main(spawner: Spawner) {
     #[cfg(not(feature = "wifi-connect"))]
     // Use a link-local address for communication without DHCP server
     let config = Config::ipv4_static(embassy_net::StaticConfigV4 {
-        address: embassy_net::Ipv4Cidr::new(embassy_net::Ipv4Address::new(192, 254, 0, 2), 16),
+        address: embassy_net::Ipv4Cidr::new(embassy_net::Ipv4Address::new(192, 254, 0, 2), 24),
         dns_servers: heapless::Vec::new(),
         gateway: None,
     });
 
     #[cfg(feature = "wifi-connect")]
-    let wifi_conf = unwrap(serde_json_core::from_slice::<WifiConnectConf>(include_bytes!("../wifi.json"))).await.0;
-    // Use a link-local address for communication without DHCP server
-    // let config = Config::dhcpv4(embassy_net::DhcpConfig::default());
-    #[cfg(feature = "wifi-connect")]
-    let config = match wifi_conf.ip {
-        Some(ip) => Config::ipv4_static(embassy_net::StaticConfigV4 {
-            address: embassy_net::Ipv4Cidr::new(ip, 24),
-            dns_servers: heapless::Vec::new(),
-            gateway: None,
-        }),
-        None => Config::dhcpv4(DhcpConfig::default())
+    let (wifi_conf, config) = {
+        let wifi_conf = unwrap(serde_json_core::from_slice::<WifiConnectConf>(
+            include_bytes!("../wifi.json"),
+        ))
+        .await
+        .0;
+        // Use a link-local address for communication without DHCP server
+        // let config = Config::dhcpv4(embassy_net::DhcpConfig::default());
+        let config = match wifi_conf.ip {
+            Some(ip) => Config::ipv4_static(embassy_net::StaticConfigV4 {
+                address: embassy_net::Ipv4Cidr::new(ip, 24),
+                dns_servers: heapless::Vec::new(),
+                gateway: None,
+            }),
+            None => Config::dhcpv4(DhcpConfig::default()),
+        };
+        (wifi_conf, config)
     };
 
-
     // Generate random seed
     let seed = rng.next_u64();
 
@@ -124,7 +130,10 @@ async fn main(spawner: Spawner) {
     {
         loop {
             match control
-                .join(wifi_conf.name, cyw43::JoinOptions::new(wifi_conf.password.as_bytes()))
+                .join(
+                    wifi_conf.name,
+                    cyw43::JoinOptions::new(wifi_conf.password.as_bytes()),
+                )
                 .await
             {
                 Ok(_) => break,
@@ -151,14 +160,17 @@ async fn main(spawner: Spawner) {
         )
     }
 
+    #[cfg(feature = "dhcp")]
+    unwrap(spawner.spawn(dhcp::dhcp_server(stack))).await;
+
     unwrap(spawner.spawn(socket::listen_task(stack, game::Team::Zero, 80))).await;
     unwrap(spawner.spawn(socket::listen_task(stack, game::Team::One, 81))).await;
 }
 
-#[cfg(feature="wifi-connect")]
+#[cfg(feature = "wifi-connect")]
 #[derive(serde::Deserialize)]
 struct WifiConnectConf<'a> {
     name: &'a str,
     password: &'a str,
-    ip: Option<Ipv4Addr>
+    ip: Option<Ipv4Addr>,
 }