Updated remote URL for async-tftp-rs so that it can be checked out anomymously

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "vendor/async-tftp-rs"]
 	path = vendor/async-tftp-rs
-	url = git@github.com:thequux/async-tftp-rs.git
+	url = https://github.com/thequux/async-tftp-rs.git

Cargo.lock

@@ -635,6 +635,12 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
 [[package]]
 name = "hyper"
 version = "0.14.27"
@@ -1242,6 +1248,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8229b473baa5980ac72ef434c4415e70c4b5e71b423043adb4ba059f89c99a1"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.9"
@@ -1280,6 +1295,7 @@ dependencies = [
  "async-tftp",
  "fern",
  "futures",
+ "humantime",
  "libc",
  "listenfd",
  "log",
@@ -1288,6 +1304,7 @@ dependencies = [
  "structopt",
  "tokio",
  "tokio-util",
+ "users",
 ]
 
 [[package]]
@@ -1432,6 +1449,7 @@ dependencies = [
  "mio",
  "num_cpus",
  "pin-project-lite",
+ "signal-hook-registry",
  "socket2 0.5.5",
  "tokio-macros",
  "windows-sys",
@@ -1550,6 +1568,16 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "users"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24cc0f6d6f267b73e5a2cadf007ba8f9bc39c6a6f9666f8cf25ea809a153b032"
+dependencies = [
+ "libc",
+ "log",
+]
+
 [[package]]
 name = "uuid"
 version = "1.5.0"

Cargo.toml

@@ -13,9 +13,11 @@ anyhow = "1"
 fern = "0.6.2"
 log = "0.4.20"
 structopt = "0.3"
-tokio = { version = "1.32.0", features = ["rt-multi-thread", "macros", "rt"] }
+tokio = { version = "1.32.0", features = ["rt-multi-thread", "macros", "rt", "signal"] }
 tokio-util = { version = "0.7.10", features = ["io", "io-util", "rt", "compat"] }
 mlua = { version = "0.9.1", features = ["luau-jit", "vendored", "async", "send"] }
 reqwest = { version = "0.11.22", features = ["stream"] }
 listenfd = "1.0.1"
-libc = "0.2.150"
+libc = "0.2.150"
+users = "0.11.0"
+humantime = "2.1.0"

devenv.nix

@@ -5,7 +5,7 @@
   #env.GREET = "devenv";
 
   # https://devenv.sh/packages/
-  packages = [ pkgs.git pkgs.openssl ];
+  packages = [ pkgs.git pkgs.openssl pkgs.lua ];
 
   # https://devenv.sh/scripts/
   #scripts.hello.exec = "echo hello from $GREET";

src/engine.rs

@@ -1,15 +1,13 @@
+use std::fmt::{Display, Formatter};
 use std::future::Future;
-use mlua::{FromLua, IntoLua, Lua, UserData, UserDataFields, Value};
-use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::path::{Path, PathBuf};
+use mlua::{FromLua, FromLuaMulti, IntoLua, Lua, UserData, UserDataFields, UserDataMethods, Value};
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
+use std::path::PathBuf;
+use std::str::FromStr;
 use anyhow::anyhow;
 use async_tftp::packet::Error;
-use futures::TryFutureExt;
-use tokio::sync::oneshot::error::RecvError;
 
-pub struct LuaRunner {
-
-}
+mod ipaddr;
 
 #[derive(Clone, Debug)]
 pub struct Client {
@@ -32,6 +30,17 @@ pub enum Resource {
     Error(Error)
 }
 
+impl Display for Resource {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Resource::Http(url) => write!(f, "HTTP {url}"),
+            Resource::File(path) => write!(f, "FILE {path}"),
+            Resource::Data(data) => write!(f, "DATA ({} bytes)", data.len()),
+            Resource::Error(err) => write!(f, "ERR {err:?}")
+        }
+    }
+}
+
 impl Resource {
 }
 
@@ -40,7 +49,7 @@ impl UserData for Resource {
 }
 
 impl<'lua> FromLua<'lua> for Resource {
-    fn from_lua(value: Value<'lua>, _lua: &'lua Lua) -> mlua::Result<Self> {
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> mlua::Result<Self> {
         value.as_userdata().ok_or(mlua::Error::UserDataTypeMismatch).and_then(|value| value.take())
     }
 }
@@ -73,16 +82,12 @@ pub struct EngineImpl {
     chan: Option<tokio::sync::mpsc::Receiver<EngineReq>>,
 }
 
+
 impl EngineImpl {
     pub(crate) fn init(&mut self) -> anyhow::Result<()> {
-        let lua = &* self.lua;
+        let lua = self.lua;
         lua.load_from_std_lib(mlua::StdLib::ALL)?;
 
-
-        lua.register_userdata_type::<IpAddr>(|registry| {
-            registry.add_field_method_get("version", |_, ip| Ok(if ip.is_ipv4() { 4} else {6}));
-        })?;
-
         {
             // prepare resource types...
             let resources = lua.create_table()?;
@@ -104,11 +109,16 @@ impl EngineImpl {
             err_tbl.set("FileAlreadyExists", Resource::Error(Error::FileAlreadyExists))?;
             err_tbl.set("NoSuchUser", Resource::Error(Error::NoSuchUser))?;
             err_tbl.set("Message", err_fn)?;
+            err_tbl.set_readonly(true);
 
             resources.set("ERROR", err_tbl)?;
+            resources.set_readonly(true);
+
             lua.globals().set("resource", resources)?;
             lua.globals().set("state", lua.create_table()?)?;
 
+            // Construct data types
+            ipaddr::register(lua)?;
             //
         }
 
@@ -181,7 +191,7 @@ impl EngineImpl {
             .into_lua(lua)
             .map_err(|err| Error::Msg(err.to_string()))?;
         let path = path.to_str().ok_or(Error::FileNotFound)?.to_owned();
-        let (resource, size): (Resource, Option<u64>) = resolver
+        let resource: Resource = resolver
             .call_async((path, lua_client.clone(), size))
             .await
             .map_err(|err| Error::Msg(err.to_string()))?;
@@ -200,8 +210,6 @@ impl Engine {
     pub fn new() -> anyhow::Result<(Self, EngineImpl)> {
         let lua = Box::leak(Box::new(mlua::Lua::new()));
         // Add stdlib
-        let handler_fn = lua.create_registry_value(0)?;
-
         let (req_snd, req_rcv) = tokio::sync::mpsc::channel(1);
 
         let engine = Self {

src/engine/ipaddr.rs

@@ -0,0 +1,238 @@
+use std::fmt::Display;
+use std::net::{IpAddr, Ipv6Addr};
+use std::str::FromStr;
+use std::fmt::Formatter;
+use mlua::{FromLua, FromLuaMulti, Lua, UserData, UserDataFields, UserDataMethods, Value};
+
+#[derive(Copy, Clone)]
+struct Cidr {
+    addr: IpAddr,
+    prefix: u8,
+}
+
+impl Display for Cidr {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}/{}", self.addr, self.prefix)
+    }
+}
+
+impl Cidr {
+    fn to_v6(&self) -> Self {
+        match self.addr {
+            IpAddr::V4(ip) => Cidr {
+                addr: IpAddr::V6(ip.to_ipv6_mapped()),
+                prefix: self.prefix + 96,
+            },
+            IpAddr::V6(_) => *self,
+        }
+    }
+}
+
+#[repr(transparent)]
+#[derive(Copy, Clone)]
+struct IpAddrWrapper(IpAddr);
+
+impl IpAddrWrapper {
+    fn octet_len(&self) -> usize {
+        match &self.0 {
+            IpAddr::V4(_) => 4,
+            IpAddr::V6(_) => 16,
+        }
+    }
+
+    fn to_v6(&self) -> Ipv6Addr {
+        match self.0 {
+            IpAddr::V4(v4) => v4.to_ipv6_mapped(),
+            IpAddr::V6(v6) => v6
+        }
+    }
+}
+
+impl UserData for IpAddrWrapper {
+    fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
+        fields.add_field_method_get("version", |_, ip| Ok(if ip.0.is_ipv4() { 4} else {6}));
+        fields.add_field_method_get("is_ipv4", |_, ip| Ok(ip.0.is_ipv4()));
+        fields.add_field_method_get("is_ipv6", |_, ip| Ok(ip.0.is_ipv6()));
+        fields.add_field_method_get("bytes", |lua, ip| match &ip.0 {
+            IpAddr::V4(v4) => lua.create_string(v4.octets()),
+            IpAddr::V6(v6) => lua.create_string(v6.octets()),
+        });
+        fields.add_meta_field("__name", "IpAddr");
+    }
+
+    fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+        methods.add_method("to_v6", |_, ip, ()| match &ip.0 {
+            IpAddr::V4(v4) => Ok(IpAddrWrapper(IpAddr::V6(v4.to_ipv6_mapped()))),
+            IpAddr::V6(v6) => Ok(IpAddrWrapper(IpAddr::V6(*v6))),
+        });
+        methods.add_meta_method("__index", |_, ip, index: usize| match &ip.0 {
+            IpAddr::V4(ip) if 1 <= index && index <= 4 => Ok(ip.octets()[index-1]),
+            IpAddr::V6(ip) if 1 <= index && index <= 16 => Ok(ip.octets()[index-1]),
+            _ => Err(mlua::Error::runtime("Index out of range")),
+        });
+        methods.add_meta_method_mut("__newindex", |_, ip, (index, value): (usize, u8)| {
+            match &mut ip.0 {
+                IpAddr::V4(ip) if 1 <= index && index <= 4 => {
+                    let mut octets = ip.octets();
+                    octets[index-1] = value;
+                    IpAddr::V4(octets.into());
+                },
+                IpAddr::V6(ip) if 1 <= index && index <= 16 => {
+                    let mut octets = ip.octets();
+                    octets[index-1] = value;
+                    IpAddr::V6(octets.into());
+                },
+                _ => return Err(mlua::Error::runtime("Index out of range")),
+            };
+            Ok(())
+        });
+        methods.add_meta_method("__tostring", |_, ip, ()|  Ok(ip.0.to_string()));
+        methods.add_meta_function("__call", |lua, args: mlua::MultiValue| Ok(IpAddrWrapper({
+            eprintln!("IpAddr __call Received {} args", args.len());
+            if args.len() == 4 {
+                // IPV4 direct bytes
+                let (a,b,c,d) = <(u8,u8,u8,u8)>::from_lua_args(args, 0, Some("sftpd.IpAddr"), lua)?;
+                IpAddr::V4([a,b,c,d].into())
+            } else if args.len() == 16 {
+                let mut octets = [0u8;16];
+                for i in 0..16 {
+                    octets[i] = u8::from_lua(args.get(i).unwrap().clone(), lua)?;
+                }
+                IpAddr::V6(octets.into())
+            } else if args.len() == 1 {
+                return IpAddrWrapper::from_lua(args[0].clone(), lua);
+            } else {
+                return Err(mlua::Error::runtime("Invalid arguments to stfptd.IpAddr"))
+            }
+        })));
+        methods.add_meta_method("__eq", |_, me, other: IpAddrWrapper| Ok(me.to_v6() == other.to_v6()))
+    }
+}
+
+impl<'lua> FromLua<'lua> for IpAddrWrapper {
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> mlua::Result<Self> {
+        return if let Some(ud) = value.as_userdata() {
+            Ok(ud.borrow::<IpAddrWrapper>()?.clone())
+        } else if let Some(s) = value.as_str() {
+            IpAddr::from_str(s)
+                .map(IpAddrWrapper)
+                .map_err(mlua::Error::external)
+        } else {
+            Err(mlua::Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: "IpAddr",
+                message: None,
+            })
+        }
+    }
+}
+
+impl UserData for Cidr {
+    fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
+        fields.add_field_method_get("addr", |_lua, cidr| Ok(IpAddrWrapper(cidr.addr)));
+        fields.add_field_method_set("addr", |_lua, cidr, value: IpAddrWrapper| {
+            if cidr.addr.is_ipv4() ^ value.0.is_ipv4() {
+                return Err(mlua::Error::runtime(format!(
+                    "Cannot assign v{} addr to v{} CIDR",
+                    if value.0.is_ipv4() { 4 } else { 6 },
+                    if cidr.addr.is_ipv4() { 4 } else { 6 },
+                )));
+            }
+            cidr.addr = value.0;
+            Ok(())
+        });
+        fields.add_field_method_get("prefix", |_lua, cidr| Ok(cidr.prefix));
+        fields.add_field_method_set("prefix", |_lua, cidr, value: u8| {
+            if value >= if cidr.addr.is_ipv4() { 32 } else { 128 } {
+                return Err(mlua::Error::runtime("Invalid prefix length"));
+            }
+            cidr.prefix = value;
+            Ok(())
+        });
+    }
+
+    fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+        methods.add_method("contains", |_, cidr, addr: IpAddrWrapper| {
+            let addr = u128::from_be_bytes(addr.to_v6().octets());
+            let cidr = cidr.to_v6();
+            if cidr.prefix == 0 {
+                // Global network
+                return Ok(true)
+            }
+            let mask = (!0u128) << (128 - cidr.prefix);
+            let network = u128::from_be_bytes(IpAddrWrapper(cidr.addr).to_v6().octets());
+
+            Ok(addr & mask == network & mask)
+        });
+
+        methods.add_meta_method("__tostring", |_, cidr, ()| Ok(cidr.to_string()));
+        methods.add_meta_method("__eq", |_, cidr, other: Cidr| {
+            let cidr = cidr.to_v6();
+            let other = other.to_v6();
+            Ok(cidr.prefix == other.prefix && cidr.addr == other.addr)
+        });
+
+        methods.add_meta_function("__call", |lua, args: mlua::MultiValue| {
+            if args.len() == 0 {
+                Ok(Cidr{addr: IpAddr::V6(Ipv6Addr::UNSPECIFIED), prefix: 0})
+            } else if args.len() == 1 {
+                Cidr::from_lua_args(args, 0, Some("stftpd.Cidr"), lua)
+            } else {
+                let (IpAddrWrapper(addr), prefix) = <(IpAddrWrapper, u8)>::from_lua_args(args, 0, Some("stftpd.Cidr"), lua)?;
+                let max_prefix = if addr.is_ipv4() { 32 } else { 64 };
+                if prefix > max_prefix {
+                    return Err(mlua::Error::runtime("Invalid prefix"));
+                }
+                Ok(Cidr{addr, prefix})
+            }
+        });
+    }
+}
+
+impl<'lua> FromLua<'lua> for Cidr {
+    fn from_lua(value: Value<'lua>, _: &'lua Lua) -> mlua::Result<Self> {
+        return if let Some(ud) = value.as_userdata() {
+            Ok(ud.borrow::<Cidr>()?.clone())
+        } else if let Some(s) = value.as_str() {
+            let (addr, prefix) = s.split_once("/")
+                .map(|(a,p)| (a,Some(p)))
+                .unwrap_or((s, None));
+            let addr = IpAddr::from_str(addr)?;
+            let prefix = prefix.map(u8::from_str)
+                .transpose()
+                .map_err(mlua::Error::external)?;
+
+            let max_prefix = if addr.is_ipv4() { 32 } else { 128 };
+            let prefix = prefix.unwrap_or(max_prefix);
+            if prefix > max_prefix {
+                return Err(mlua::Error::runtime("CIDR prefix to long"))
+            }
+
+            Ok(Cidr {
+                addr, prefix
+            })
+        } else {
+            Err(mlua::Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: "Cidr",
+                message: None,
+            })
+        }
+    }
+}
+
+pub fn register(lua: &'static Lua) -> anyhow::Result<()> {
+    let globals = lua.globals();
+    let stftpd: Value = globals.get("stftpd")?;
+    let stftpd = if stftpd.is_nil() {
+        let newtab = lua.create_table()?;
+        globals.set("stftpd", newtab.clone())?;
+        newtab
+    } else {
+        stftpd.as_table().unwrap().clone()
+    };
+    stftpd.set("Cidr", lua.create_proxy::<Cidr>()?)?;
+    stftpd.set("IpAddr", lua.create_proxy::<IpAddrWrapper>()?)?;
+
+    Ok(())
+}

src/handler.rs

@@ -1,15 +1,13 @@
 // SPDX-License-Identifier: MIT
-use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::future::Future;
-use std::path::{Path, PathBuf};
+use std::net::SocketAddr;
+use std::path::Path;
 use std::sync::Arc;
-use async_lock::Mutex;
 use async_tftp::async_trait;
 use async_tftp::packet::Error;
 use async_tftp::server::handlers::{DirHandler, DirHandlerMode};
 use futures::{AsyncRead, AsyncWrite, TryStreamExt};
-use mlua::{FromLua, UserDataFields};
-use reqwest::Body;
+use log::info;
+use reqwest::{Body, StatusCode};
 use tokio_util::compat::TokioAsyncWriteCompatExt;
 use crate::engine::{Client, Engine, Resource};
 
@@ -47,12 +45,21 @@ impl async_tftp::server::Handler for Handler {
         // .to_str().ok_or(Error::FileNotFound)?.to_owned()
         let resource: Resource = self.engine.resolve(path.to_owned(), &mut lua_client, None).await?;
 
+        info!("GET {path:?} from {client:?} -> {resource}");
+
         match resource {
             Resource::Http(url) => {
                 // TODO: Add headers describing client
-                let req = self.http.get(url).send().await.map_err(|err| Error::Msg(err.to_string()))?;
-                let size = req.content_length();
-                let stream = req.bytes_stream()
+                let resp = self.http.get(url).send().await.map_err(|err| Error::Msg(err.to_string()))?;
+                match resp.status() {
+                    StatusCode::OK => {},
+                    StatusCode::NOT_FOUND => return Err(Error::FileNotFound),
+                    StatusCode::UNAUTHORIZED => return Err(Error::PermissionDenied),
+                    x => return Err(Error::Msg(x.to_string()))
+                }
+
+                let size = resp.content_length();
+                let stream = resp.bytes_stream()
                     .map_err(|e| futures::io::Error::new(futures::io::ErrorKind::Other, e))
                     .into_async_read();
 
@@ -79,6 +86,7 @@ impl async_tftp::server::Handler for Handler {
             for_write: false,
         };
         let resource: Resource = self.engine.resolve(path.to_owned(), &mut lua_client, size).await?;
+        info!("PUT {path:?} from {client:?} -> {resource}");
 
         match resource {
             Resource::Http(url) => {

src/main.rs

@@ -3,8 +3,10 @@ use std::ffi::c_void;
 use std::net;
 use std::net::{Ipv4Addr, Ipv6Addr};
 use std::path::{Path, PathBuf};
+use std::time::SystemTime;
 use anyhow::anyhow;
 use structopt::StructOpt;
+use tokio::signal::unix::SignalKind;
 
 mod handler;
 mod engine;
@@ -35,6 +37,42 @@ struct Options {
 async fn main() -> anyhow::Result<()> {
     let opts = Options::from_args();
 
+    // Configure logging
+    fern::Dispatch::new()
+        .format(|out, message, record| {
+            out.finish(format_args!(
+                "[{} {} {}] {}",
+                humantime::format_rfc3339_seconds(SystemTime::now()),
+                record.level(),
+                record.target(),
+                message
+            ))
+        })
+        .level(log::LevelFilter::Debug)
+        .chain(std::io::stdout())
+        .chain(fern::log_file("output.log")?)
+        .apply()?;
+
+    let group = opts.group.map(|name| {
+        if let Ok(gid) = libc::gid_t::from_str_radix(name.as_str(), 10) {
+            Ok(gid)
+        } else {
+            users::get_group_by_name(name.as_str())
+                .ok_or(anyhow!("Error dropping privileges: No such group"))
+                .map(|group| group.gid())
+        }
+    }).transpose()?;
+    let user = opts.user.map(|name| {
+        if let Ok(uid) = libc::gid_t::from_str_radix(name.as_str(), 10) {
+            Ok(uid)
+        } else {
+            users::get_user_by_name(name.as_str())
+                .ok_or(anyhow!("Error dropping privileges: No such user"))
+                .map(|user| user.uid())
+        }
+    }).transpose()?;
+
+
     let local_set = tokio::task::LocalSet::new();
 
     let (engine, mut engine_impl) = engine::Engine::new()?;
@@ -42,8 +80,17 @@ async fn main() -> anyhow::Result<()> {
     engine_impl.load_script(opts.script.clone()).await?;
 
     local_set.spawn_local(engine_impl.run());
-
-    let mut handler = handler::Handler::new(
+    {
+        let engine = engine.clone();
+        let script = opts.script.clone();
+        let mut hup_stream = tokio::signal::unix::signal(SignalKind::hangup())?;
+        local_set.spawn_local(async move {
+            while let Some(_) = hup_stream.recv().await {
+                engine.load_script(script.clone()).await.ok();
+            }
+        });
+    }
+    let handler = handler::Handler::new(
         engine.clone(),
         opts.serve.as_ref()
             .map(PathBuf::as_path)
@@ -106,15 +153,31 @@ async fn main() -> anyhow::Result<()> {
         } else {
             net::UdpSocket::bind((host, port))?
         }
-
     };
 
+
+    let server = async_tftp::server::TftpServerBuilder::with_handler(handler.clone())
+        .std_socket(sock)?
+        .build().await?;
+
+    // Drop privileges
+    if let Some(group) = group {
+        unsafe {
+            if libc::setgid(group) < 0 {
+                return Err(std::io::Error::last_os_error().into())
+            }
+        }
+    }
+
+    if let Some(uid) = user {
+        unsafe {
+            if libc::setuid(uid) < 0 {
+                return Err(std::io::Error::last_os_error().into())
+            }
+        }
+    }
+
     let main_task = async move {
-
-        let server = async_tftp::server::TftpServerBuilder::with_handler(handler.clone())
-            .std_socket(sock)?
-            .build().await?;
-
         server.serve().await?;
         Ok::<(), anyhow::Error>(())
     };