feat: Added ftfp server implementation

Signed-off-by: Release-plz <release-plz@noreply.huizinga.dev>

.gitea/workflows/ci.yaml

@@ -7,6 +7,10 @@ on:
       - "*"
   pull_request:
 
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+
 jobs:
   prek:
     name: prek

.gitea/workflows/committed.yaml

@@ -0,0 +1,19 @@
+name: Committed
+on:
+  pull_request:
+
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+
+jobs:
+  committed:
+    name: committed
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v6
+      with:
+        fetch-depth: 0
+    - uses: crate-ci/committed@master
+      with:
+        commits: "origin/${{ gitea.base_ref }}..HEAD"

.gitea/workflows/release-plz.yaml

@@ -32,11 +32,11 @@ jobs:
         run: |
           git config user.name "Release-plz"
           git config user.email "release-plz@noreply.huizinga.dev"
-          git config url.https://${{ gitea.actor }}:${{ secrets.GITEA_TOKEN }}@git.huizinga.dev/.insteadOf https://git.huizinga.dev/
+          git config url.https://${{ gitea.actor }}:${{ secrets.RELEASE_PLZ_TOKEN }}@git.huizinga.dev/.insteadOf https://git.huizinga.dev/
       - name: release-plz release
         env:
-          CARGO_REGISTRIES_INFRA_TOKEN: "Bearer ${{ secrets.REGISTRY_TOKEN }}"
+          CARGO_REGISTRIES_INFRA_TOKEN: "Bearer ${{ secrets.RELEASE_PLZ_TOKEN }}"
-        run: release-plz release --git-token "${{ secrets.GITEA_TOKEN }}" --forge gitea --dry-run
+        run: release-plz release --git-token "${{ secrets.RELEASE_PLZ_TOKEN }}" --forge gitea
 
   release-plz-pr:
     name: Release-plz PR
@@ -59,4 +59,4 @@ jobs:
           tool: release-plz
       - *git-setup
       - name: release-plz release-pr
-        run: release-plz release-pr --git-token "${{ secrets.GITEA_TOKEN }}" --forge gitea
+        run: release-plz release-pr --git-token "${{ secrets.RELEASE_PLZ_TOKEN }}" --forge gitea

.gitea/workflows/release.yaml

@@ -18,8 +18,8 @@ jobs:
         uses: https://git.huizinga.dev/infra/archlinux-package-action@v4
         with:
           path: .
-      - run: ls | grep -E 'crete-[0-9]+\.[0-9]+\.[0-9]+-[0-9]+-.*.pkg.tar.zst'
       - name: Upload package
-        run: curl --user ${{ gitea.actor }}:${{ secrets.GITEA_TOKEN }} \
+        run: |
-          --upload-file="$(ls | grep -E 'crete-[0-9]+\.[0-9]+\.[0-9]+-[0-9]+-.*.pkg.tar.zst')" \
+          curl --user ${{ gitea.actor }}:${{ secrets.REGISTRY_TOKEN }} \
+          --upload-file "$(ls | grep -E 'crete-[0-9]+\.[0-9]+\.[0-9]+-[0-9]+-.*.pkg.tar.zst')" \
           https://git.huizinga.dev/api/packages/infra/arch/core

.pre-commit-config.yaml

@@ -31,6 +31,7 @@ repos:
     rev: "1.0.0"
     hooks:
       - id: mdformat
+        exclude: "^CHANGELOG.md$"
 
   - repo: local
     hooks:

CHANGELOG.md

@@ -1 +1,53 @@
 # Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.1.2](https://git.huizinga.dev/infra/crete/compare/v0.1.1...v0.1.2) - 2026-04-17
+
+### <!-- 0 -->Features
+
+- Make dns optional
+- Allow more than two dns entries
+
+## [0.1.1](https://git.huizinga.dev/infra/crete/compare/v0.1.0...v0.1.1) - 2026-04-13
+
+### <!-- 2 -->Bug Fixes
+
+- No default value for advertise routes
+
+## [0.1.0](https://git.huizinga.dev/infra/crete/releases/tag/v0.1.0) - 2026-04-07
+
+### <!-- 0 -->Features
+
+- _(package)_ Added PKGBUILD
+- Set user agent
+- _(performance)_ Disable request features to reduce binary size
+- Generate talos configs
+- Show error if no clusters are found in repo
+- Initial rewrite of python render tool
+
+### <!-- 3 -->Refactor
+
+- Big internal refactor
+
+### <!-- 4 -->Testing
+
+- Disable building tests
+
+### <!-- 5 -->Miscellaneous Tasks
+
+- _(actions)_ Publish Arch Linux package
+- _(license)_ Add GPL license
+- _(actions)_ Name steps
+- _(actions)_ Renamed release-plz workflow file
+- _(actions)_ Use committed to check pr commits
+- _(actions)_ Cancel in-progress ci runs when pushing to pr
+- _(docs)_ Added README
+- _(actions)_ Setup workflows
+- Publish to gitea registry
+- _(pre-commit)_ Update pre commit config

Cargo.lock

@@ -214,12 +214,15 @@ dependencies = [
 
 [[package]]
 name = "crete"
-version = "0.1.0"
+version = "0.1.2"
 dependencies = [
+ "byteorder",
  "clap",
  "clap_complete",
  "gix-discover",
  "minijinja",
+ "netascii",
+ "num_enum",
  "optional_struct",
  "reqwest",
  "schemars",
@@ -228,6 +231,7 @@ dependencies = [
  "serde_json",
  "serde_yaml",
  "thiserror",
+ "tokio",
  "walkdir",
 ]
 
@@ -447,7 +451,7 @@ dependencies = [
  "bstr",
  "gix-date",
  "gix-error",
- "winnow",
+ "winnow 0.7.15",
 ]
 
 [[package]]
@@ -567,7 +571,7 @@ dependencies = [
  "itoa",
  "smallvec",
  "thiserror",
- "winnow",
+ "winnow 0.7.15",
 ]
 
 [[package]]
@@ -600,7 +604,7 @@ dependencies = [
  "gix-validate",
  "memmap2",
  "thiserror",
- "winnow",
+ "winnow 0.7.15",
 ]
 
 [[package]]
@@ -1125,6 +1129,34 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "netascii"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "205c45083b6725eb4671392c7c399510ad1498dd0275f1a2e68a70a34ebdf1b1"
+
+[[package]]
+name = "num_enum"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d0bca838442ec211fa11de3a8b0e0e8f3a4522575b5c4c06ed722e005036f26"
+dependencies = [
+ "num_enum_derive",
+ "rustversion",
+]
+
+[[package]]
+name = "num_enum_derive"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "680998035259dcfcafe653688bf2aa6d3e2dc05e98be6ab46afb089dc84f1df8"
+dependencies = [
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.4"
@@ -1277,6 +1309,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "proc-macro-crate"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e67ba7e9b2b56446f1d419b1d807906278ffa1a658a8a5d8a39dcb1f5a78614f"
+dependencies = [
+ "toml_edit",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.106"
@@ -1628,6 +1669,16 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4db69cba1110affc0e9f7bcd48bbf87b3f4fc7c61fc9155afd4c469eb3d6c1b"
+dependencies = [
+ "errno",
+ "libc",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.12"
@@ -1753,18 +1804,32 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "tokio"
-version = "1.50.0"
+version = "1.52.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "27ad5e34374e03cfffefc301becb44e9dc3c17584f414349ebe29ed26661822d"
+checksum = "b67dee974fe86fd92cc45b7a95fdd2f99a36a6d7b0d431a231178d3d670bbcc6"
 dependencies = [
  "bytes",
  "libc",
  "mio",
+ "parking_lot",
  "pin-project-lite",
+ "signal-hook-registry",
  "socket2",
+ "tokio-macros",
  "windows-sys",
 ]
 
+[[package]]
+name = "tokio-macros"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tokio-native-tls"
 version = "0.3.1"
@@ -1788,6 +1853,36 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "toml_datetime"
+version = "1.1.1+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3165f65f62e28e0115a00b2ebdd37eb6f3b641855f9d636d3cd4103767159ad7"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "toml_edit"
+version = "0.25.11+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b59c4d22ed448339746c59b905d24568fcbb3ab65a500494f7b8c3e97739f2b"
+dependencies = [
+ "indexmap",
+ "toml_datetime",
+ "toml_parser",
+ "winnow 1.0.2",
+]
+
+[[package]]
+name = "toml_parser"
+version = "1.1.2+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2abe9b86193656635d2411dc43050282ca48aa31c2451210f4202550afb7526"
+dependencies = [
+ "winnow 1.0.2",
+]
+
 [[package]]
 name = "tower"
 version = "0.5.3"
@@ -2115,6 +2210,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "winnow"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ee1708bef14716a11bae175f579062d4554d95be2c6829f518df847b7b3fdd0"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "wit-bindgen"
 version = "0.51.0"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "crete"
-version = "0.1.0"
+version = "0.1.2"
 edition = "2024"
 default-run = "crete"
 publish = ["infra"]
@@ -14,10 +14,13 @@ schemars = { version = "1.2.1", features = ["semver1"] }
 serde_json = "1.0.149"
 
 [dependencies]
+byteorder = "1.5.0"
 clap = { version = "4.6.0", features = ["derive"] }
 clap_complete = "4.6.0"
 gix-discover = { version = "0.49.0", features = ["sha1"] }
 minijinja = { version = "2.18.0", features = ["json", "loader"] }
+netascii = "0.1.0"
+num_enum = "0.7.6"
 optional_struct = "0.5.2"
 reqwest = { version = "0.13.2", default-features = false, features = [
   "blocking",
@@ -30,6 +33,7 @@ serde = { version = "1.0.228", features = ["derive"] }
 serde_json = { workspace = true }
 serde_yaml = "0.9.34"
 thiserror = "2.0.18"
+tokio = { version = "1.52.1", features = ["full"] }
 walkdir = "2.5.0"
 
 [lib]

schemas/cluster.json

@@ -140,12 +140,11 @@
             "array",
             "null"
           ],
+          "default": null,
           "items": {
             "type": "string",
             "format": "ipv4"
-          },
+          }
-          "maxItems": 2,
-          "minItems": 2
         },
         "gateway": {
           "type": [

schemas/node.json

@@ -136,12 +136,11 @@
             "array",
             "null"
           ],
+          "default": null,
           "items": {
             "type": "string",
             "format": "ipv4"
-          },
+          }
-          "maxItems": 2,
-          "minItems": 2
         },
         "gateway": {
           "type": [

src/environment.rs

@@ -1,8 +1,8 @@
 use std::net::Ipv4Addr;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
-use std::str::FromStr;
 
+use minijinja::value::ViaDeserialize;
 use minijinja::{AutoEscape, Environment, path_loader};
 use walkdir::WalkDir;
 
@@ -16,6 +16,13 @@ pub struct PathEnvironment<'a> {
     path: PathBuf,
 }
 
+fn apply_netmask(
+    ip: ViaDeserialize<Ipv4Addr>,
+    netmask: ViaDeserialize<Ipv4Addr>,
+) -> Result<String, minijinja::Error> {
+    Ok((*ip & *netmask).to_string())
+}
+
 impl<'a> PathEnvironment<'a> {
     pub fn new(path: &Path) -> Self {
         let mut env = Environment::new();
@@ -27,10 +34,7 @@ impl<'a> PathEnvironment<'a> {
         env.set_auto_escape_callback(|_| AutoEscape::None);
 
         // Add filters
-        env.add_filter("to_prefix", |netmask: String| {
+        env.add_filter("to_prefix", |netmask: ViaDeserialize<Ipv4Addr>| {
-            let netmask = Ipv4Addr::from_str(&netmask).map_err(|err| {
-                minijinja::Error::new(minijinja::ErrorKind::InvalidOperation, err.to_string())
-            })?;
             let mask = netmask.to_bits();
             let prefix = mask.leading_ones();
 
@@ -44,6 +48,8 @@ impl<'a> PathEnvironment<'a> {
             }
         });
 
+        env.add_function("apply_netmask", apply_netmask);
+
         // Helper function for getting the path to kubeconfig files
         env.add_filter("kubeconfig", move |names: Vec<String>| {
             names

src/lib.rs

@@ -8,6 +8,7 @@ pub mod node;
 pub mod patch;
 pub mod schematic;
 pub mod secret;
+pub mod tftp;
 
 pub(crate) static REPO_PATH: OnceLock<PathBuf> = OnceLock::new();
 

src/node.rs

@@ -53,7 +53,8 @@ struct Network {
     ip: Ipv4Addr,
     netmask: Ipv4Addr,
     gateway: Ipv4Addr,
-    dns: [Ipv4Addr; 2],
+    #[serde(default)]
+    dns: Option<Vec<Ipv4Addr>>,
     #[optional_rename(OptionalTailscale)]
     #[optional_wrap]
     tailscale: Tailscale,
@@ -128,6 +129,13 @@ impl Node {
         // Sadly we have to this manually
         // TODO: Find a better way of doing this
         let default = OptionalNodeDeserialize {
+            network: Some(OptionalNetwork {
+                tailscale: Some(OptionalTailscale {
+                    advertise_routes: Some(false),
+                    ..Default::default()
+                }),
+                ..Default::default()
+            }),
             patches: Some(OptionalPatches {
                 all: Some(vec![]),
                 control_plane: Some(vec![]),

src/schematic.rs

@@ -11,7 +11,15 @@ where
     let path = get_talos_path().join("schematics").join(name);
     let content = std::fs::read_to_string(path).unwrap().trim().to_owned();
 
-    let client = reqwest::blocking::Client::new();
+    let client = reqwest::blocking::ClientBuilder::new()
+        .user_agent(format!(
+            "{}/{}",
+            std::env!("CARGO_PKG_NAME"),
+            std::env!("CARGO_PKG_VERSION")
+        ))
+        .build()
+        .unwrap();
+
     let res = client
         .post("https://factory.talos.dev/schematics")
         .body(content)

src/tftp/error.rs

@@ -0,0 +1,20 @@
+use std::io;
+use std::string::FromUtf8Error;
+
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("Invalid op code '{0}'")]
+    InvalidOpCode(u16),
+    #[error("Invalid error code '{0}'")]
+    InvalidErrorCode(u16),
+    #[error("Invalid mode '{0}'")]
+    InvalidMode(String),
+    #[error("String contains invalid characters")]
+    InvalidString(#[from] FromUtf8Error),
+    #[error("Unterminated string")]
+    UnterminatedString,
+    #[error("Io error: {0}")]
+    Io(#[from] io::Error),
+}

src/tftp/mod.rs

@@ -0,0 +1,7 @@
+mod error;
+mod packet;
+mod server;
+
+pub use error::Error;
+pub use packet::Packet;
+pub use server::{Error as ServerError, serve};

src/tftp/packet.rs

@@ -0,0 +1,353 @@
+use std::io::{BufRead, BufReader, BufWriter, Cursor, Read, Write};
+use std::net::SocketAddr;
+
+use byteorder::{NetworkEndian, ReadBytesExt, WriteBytesExt};
+use num_enum::{IntoPrimitive, TryFromPrimitive};
+use tokio::net::UdpSocket;
+
+use crate::tftp::Error;
+
+// 2 bytes op code + 2 bytes block number + max 512 bytes data
+pub(crate) const PACKET_SIZE: usize = 2 + 2 + 512;
+
+fn decode_null_terminated<R>(reader: &mut BufReader<R>) -> Result<String, Error>
+where
+    R: Read + ?Sized,
+{
+    let mut text = Vec::new();
+    reader.read_until(0, &mut text)?;
+
+    // Make sure we ended with a null terminator
+    match text.pop() {
+        Some(0) => {}
+        None | Some(_) => return Err(Error::UnterminatedString),
+    }
+
+    Ok(String::from_utf8(text)?)
+}
+
+fn encode_null_terminated<W>(writer: &mut BufWriter<W>, text: impl AsRef<str>) -> Result<(), Error>
+where
+    W: Write + ?Sized,
+{
+    let text = text.as_ref().as_bytes();
+    writer.write_all(text)?;
+
+    // Add null terminator
+    writer.write_u8(0)?;
+
+    Ok(())
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Mode {
+    NetAscii,
+    Octet,
+    Mail,
+}
+
+impl Mode {
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let mut mode = decode_null_terminated(reader)?;
+        mode.make_ascii_lowercase();
+        let mode = mode;
+
+        Ok(match mode.as_str() {
+            "netascii" => Self::NetAscii,
+            "octet" => Self::Octet,
+            "mail" => Self::Mail,
+            _ => return Err(Error::InvalidMode(mode)),
+        })
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        let mode = match &self {
+            Mode::NetAscii => "netascii",
+            Mode::Octet => "octet",
+            Mode::Mail => "mail",
+        };
+
+        encode_null_terminated(writer, mode)?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Request {
+    filename: String,
+    mode: Mode,
+}
+
+impl Request {
+    pub fn filename(&self) -> &str {
+        &self.filename
+    }
+
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let filename = decode_null_terminated(reader)?;
+        let mode = Mode::decode(reader)?;
+
+        Ok(Self { filename, mode })
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        encode_null_terminated(writer, &self.filename)?;
+        self.mode.encode(writer)?;
+
+        Ok(())
+    }
+
+    pub fn mode(&self) -> Mode {
+        self.mode
+    }
+}
+
+#[derive(Debug)]
+pub struct Data {
+    block: u16,
+    data: Vec<u8>,
+}
+
+impl Data {
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let block = reader.read_u16::<NetworkEndian>()?;
+
+        let mut data = Vec::new();
+        reader.read_to_end(&mut data)?;
+
+        Ok(Self { data, block })
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        writer.write_u16::<NetworkEndian>(self.block)?;
+        writer.write_all(&self.data)?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+pub struct Ack(u16);
+
+impl Ack {
+    pub fn block(&self) -> u16 {
+        self.0
+    }
+
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let number = reader.read_u16::<NetworkEndian>()?;
+
+        Ok(Self(number))
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        writer.write_u16::<NetworkEndian>(self.0)?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, TryFromPrimitive, IntoPrimitive, Clone, Copy)]
+#[repr(u16)]
+pub enum ErrorCode {
+    NotDefined,
+    FileNotFound,
+    AccessViolation,
+    DiskFull,
+    Illegal,
+    UnknownTransferId,
+    FileAlreadyExists,
+    NoSuchUser,
+}
+
+impl ErrorCode {
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let code = reader.read_u16::<NetworkEndian>()?;
+        Self::try_from_primitive(code).map_err(|err| Error::InvalidErrorCode(err.number))
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        let code: u16 = (*self).into();
+
+        writer.write_u16::<NetworkEndian>(code)?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+pub struct ErrorMessage {
+    code: ErrorCode,
+    message: String,
+}
+
+impl ErrorMessage {
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let code = ErrorCode::decode(reader)?;
+        let message = decode_null_terminated(reader)?;
+
+        Ok(Self { code, message })
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        self.code.encode(writer)?;
+
+        encode_null_terminated(writer, &self.message)?;
+
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+pub enum Packet {
+    Read(Request),
+    Write(Request),
+    Data(Data),
+    Ack(Ack),
+    Error(ErrorMessage),
+}
+
+impl Packet {
+    pub fn data(block: u16, data: &[u8]) -> Self {
+        Self::Data(Data {
+            block,
+            data: data.into(),
+        })
+    }
+
+    pub fn ack(block: u16) -> Self {
+        Self::Ack(Ack(block))
+    }
+
+    pub fn error(code: ErrorCode, message: impl Into<String>) -> Self {
+        Self::Error(ErrorMessage {
+            code,
+            message: message.into(),
+        })
+    }
+
+    fn decode<R>(reader: &mut BufReader<R>) -> Result<Self, Error>
+    where
+        R: Read + ?Sized,
+    {
+        let op_code = reader.read_u16::<NetworkEndian>()?;
+
+        Ok(match op_code {
+            1 => Self::Read(Request::decode(reader)?),
+            2 => Self::Write(Request::decode(reader)?),
+            3 => Self::Data(Data::decode(reader)?),
+            4 => Self::Ack(Ack::decode(reader)?),
+            5 => Self::Error(ErrorMessage::decode(reader)?),
+            _ => return Err(Error::InvalidOpCode(op_code)),
+        })
+    }
+
+    fn encode<W>(&self, writer: &mut BufWriter<W>) -> Result<(), Error>
+    where
+        W: Write + ?Sized,
+    {
+        match &self {
+            Self::Read(inner) => {
+                writer.write_u16::<NetworkEndian>(1)?;
+                inner.encode(writer)?;
+            }
+            Self::Write(inner) => {
+                writer.write_u16::<NetworkEndian>(2)?;
+                inner.encode(writer)?;
+            }
+            Self::Data(inner) => {
+                writer.write_u16::<NetworkEndian>(3)?;
+                inner.encode(writer)?;
+            }
+            Self::Ack(inner) => {
+                writer.write_u16::<NetworkEndian>(4)?;
+                inner.encode(writer)?;
+            }
+            Self::Error(inner) => {
+                writer.write_u16::<NetworkEndian>(5)?;
+                inner.encode(writer)?;
+            }
+        };
+
+        Ok(())
+    }
+
+    pub async fn recv_from(socket: &UdpSocket) -> Result<(Self, SocketAddr), Error> {
+        let mut buf = Vec::with_capacity(PACKET_SIZE);
+        let (_, src) = socket.recv_buf_from(&mut buf).await?;
+
+        let packet = buf.try_into()?;
+
+        Ok((packet, src))
+    }
+
+    pub async fn send_to(&self, socket: &UdpSocket, src: &SocketAddr) -> Result<(), Error> {
+        let buf: Vec<_> = self.try_into()?;
+        socket.send_to(&buf, src).await?;
+
+        Ok(())
+    }
+}
+
+impl TryFrom<&Packet> for Vec<u8> {
+    type Error = Error;
+
+    fn try_from(packet: &Packet) -> Result<Self, Self::Error> {
+        let mut buf = Vec::with_capacity(PACKET_SIZE);
+        let mut writer = BufWriter::new(Cursor::new(&mut buf));
+        packet.encode(&mut writer)?;
+
+        // Normally the writer would get dropped after we return, but since it has a mutable
+        // borrow in buf we have to drop it first.
+        drop(writer);
+
+        Ok(buf)
+    }
+}
+
+impl TryFrom<Vec<u8>> for Packet {
+    type Error = Error;
+
+    fn try_from(buf: Vec<u8>) -> Result<Self, <Packet as TryFrom<Vec<u8>>>::Error> {
+        let mut reader = BufReader::new(Cursor::new(buf));
+
+        Packet::decode(&mut reader)
+    }
+}

src/tftp/server.rs

@@ -0,0 +1,162 @@
+use std::io;
+use std::net::SocketAddr;
+use std::time::Duration;
+
+use thiserror::Error;
+use tokio::net::UdpSocket;
+
+use crate::tftp::packet::{ErrorCode, Mode};
+use crate::tftp::{self, Packet};
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("{0}")]
+    Tftp(#[from] tftp::Error),
+    #[error("Io error: {0}")]
+    Io(#[from] io::Error),
+    #[error("Unsupported operation: {0:#?}")]
+    UnsupportedOperation(Packet),
+    #[error("File not found: {0}")]
+    FileNotFound(String),
+    #[error("Unsupported mode: {0:?}")]
+    UnsupportedMode(Mode),
+    #[error("Source changed: {0}")]
+    SourceChanged(SocketAddr),
+    #[error("UnexpectedPacket: {0:#?}")]
+    UnexpectedPacket(Packet),
+    #[error("Timeout")]
+    Timeout,
+}
+
+pub async fn handle_connection(
+    src: SocketAddr,
+    packet: Packet,
+    callback: impl (Fn(&str) -> Option<Vec<u8>>) + Send + Clone + 'static,
+) -> Result<(), Error> {
+    let socket = UdpSocket::bind("127.0.0.1:0").await?;
+    println!(
+        "{src}: Connecting from {}",
+        socket.local_addr().expect("Socket is bound")
+    );
+
+    let Packet::Read(request) = packet else {
+        Packet::error(ErrorCode::NotDefined, "Operation not supported")
+            .send_to(&socket, &src)
+            .await?;
+
+        return Err(Error::UnsupportedOperation(packet));
+    };
+
+    let filename = request.filename();
+    println!("{src}: {filename} [{:?}]", request.mode());
+
+    let Some(data) = callback(filename) else {
+        Packet::error(ErrorCode::FileNotFound, "Unknown file")
+            .send_to(&socket, &src)
+            .await?;
+
+        return Err(Error::FileNotFound(filename.into()));
+    };
+
+    let mode = request.mode();
+    let data = match mode {
+        // In case of netascii mode we need to re-encode to escape certain sequences
+        Mode::NetAscii => netascii::Netascii::from_bytes(data).collect(),
+        Mode::Octet => data,
+        _ => {
+            Packet::error(
+                ErrorCode::NotDefined,
+                format!("Mode {mode:?} is not supported"),
+            )
+            .send_to(&socket, &src)
+            .await?;
+
+            return Err(Error::UnsupportedMode(mode));
+        }
+    };
+
+    let mut chunks = data.chunks(512).enumerate();
+    let mut chunk = chunks.next();
+
+    let mut timeout = 0;
+
+    loop {
+        // Send the first byte
+        if let Some((index, chunk)) = chunk {
+            Packet::data((index + 1) as u16, chunk)
+                .send_to(&socket, &src)
+                .await?;
+        }
+
+        tokio::select! {
+            recv = Packet::recv_from(&socket) => {
+                timeout = 0;
+                let (packet, new_src) = recv?;
+
+                // I think this is might technically be possible and fine, but I don't
+                // really know how to test it properly so we don't support it.
+                if new_src != src {
+                    Packet::error(ErrorCode::Illegal, "Source changed")
+                        .send_to(&socket, &src)
+                        .await?;
+
+                    return Err(Error::SourceChanged(new_src));
+                }
+
+                match packet {
+                    Packet::Ack(ack) => {
+                        // If we receive an ack for the current chunk go to the next one
+                        if let Some((index, _)) = chunk
+                            && (index + 1) as u16 == ack.block()
+                        {
+                            chunk = chunks.next();
+                        }
+
+                        if chunk.is_none() {
+                            break;
+                        }
+                    }
+                    _ => {
+                        Packet::error(ErrorCode::Illegal, "Unexpected packet")
+                            .send_to(&socket, &src)
+                            .await?;
+
+
+                        return Err(Error::UnexpectedPacket(packet));
+                    }
+                }
+            },
+            _ = tokio::time::sleep(Duration::from_secs(1)) => {
+                timeout += 1;
+
+                if timeout == 5 {
+                    return Err(Error::Timeout);
+                }
+            }
+        }
+    }
+
+    println!("{src}: Transmission complete");
+
+    Ok(())
+}
+
+pub async fn serve(
+    callback: impl (Fn(&str) -> Option<Vec<u8>>) + Send + Clone + 'static,
+) -> Result<(), Error> {
+    let socket = UdpSocket::bind("127.0.0.1:69").await?;
+
+    println!("Server started");
+    loop {
+        let (packet, src) = Packet::recv_from(&socket).await?;
+
+        let callback = callback.clone();
+        tokio::spawn({
+            async move {
+                if let Err(err) = handle_connection(src, packet, callback).await {
+                    println!("{src}: {err}")
+                }
+            }
+        });
+    }
+}