Cargo.lock

@@ -1154,7 +1154,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
  "cfg-if",
- "serde",
 ]
 
 [[package]]

Cargo.toml

@@ -26,7 +26,7 @@ ctrlc = "3"
 dotenv = "0.15"
 futures = "0.3"
 once_cell = "1"
-log = { version = "0.4", features = [ "serde" ] }
+log = "0.4"
 lfu_cache = "1"
 lru = "0.6"
 parking_lot = "0.11"

src/cache/disk.rs

@@ -6,6 +6,7 @@ use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::Arc;
 
 use async_trait::async_trait;
+use bytes::Bytes;
 use futures::StreamExt;
 use log::{error, warn, LevelFilter};
 use sqlx::sqlite::SqliteConnectOptions;
@@ -14,8 +15,6 @@ use tokio::fs::remove_file;
 use tokio::sync::mpsc::{channel, Receiver, Sender};
 use tokio_stream::wrappers::ReceiverStream;
 
-use crate::units::Bytes;
-
 use super::{
     BoxedImageStream, Cache, CacheError, CacheKey, CacheStream, CallbackCache, ImageMetadata,
 };
@@ -35,7 +34,7 @@ impl DiskCache {
     /// Constructs a new low memory cache at the provided path and capacity.
     /// This internally spawns a task that will wait for filesystem
     /// notifications when a file has been written.
-    pub async fn new(disk_max_size: Bytes, disk_path: PathBuf) -> Arc<Self> {
+    pub async fn new(disk_max_size: u64, disk_path: PathBuf) -> Arc<Self> {
         let (db_tx, db_rx) = channel(128);
         let db_pool = {
             let db_url = format!("sqlite:{}/metadata.sqlite", disk_path.to_string_lossy());
@@ -76,7 +75,7 @@ impl DiskCache {
             Arc::clone(&new_self),
             db_rx,
             db_pool,
-            disk_max_size.get() as u64 / 20 * 19,
+            disk_max_size / 20 * 19,
         ));
 
         new_self
@@ -238,7 +237,7 @@ impl CallbackCache for DiskCache {
         key: CacheKey,
         image: BoxedImageStream,
         metadata: ImageMetadata,
-        on_complete: Sender<(CacheKey, bytes::Bytes, ImageMetadata, u64)>,
+        on_complete: Sender<(CacheKey, Bytes, ImageMetadata, u64)>,
     ) -> Result<CacheStream, CacheError> {
         let channel = self.db_update_channel_sender.clone();
 

src/cache/mem.rs

@@ -86,7 +86,7 @@ where
     MemoryCacheImpl: 'static + InternalMemoryCache,
     ColdCache: 'static + Cache,
 {
-    pub async fn new(inner: ColdCache, max_mem_size: crate::units::Bytes) -> Arc<Self> {
+    pub async fn new(inner: ColdCache, max_mem_size: u64) -> Arc<Self> {
         let (tx, mut rx) = channel(100);
         let new_self = Arc::new(Self {
             inner,
@@ -98,7 +98,7 @@ where
         let new_self_0 = Arc::clone(&new_self);
         tokio::spawn(async move {
             let new_self = new_self_0;
-            let max_mem_size = max_mem_size.get() / 20 * 19;
+            let max_mem_size = max_mem_size / 20 * 19;
             while let Some((key, bytes, metadata, size)) = rx.recv().await {
                 // Add to memory cache
                 // We can add first because we constrain our memory usage to 95%
@@ -112,7 +112,7 @@ where
                     .push(key, (bytes, metadata, size));
 
                 // Pop if too large
-                while new_self.cur_mem_size.load(Ordering::Acquire) >= max_mem_size as u64 {
+                while new_self.cur_mem_size.load(Ordering::Acquire) >= max_mem_size {
                     let popped = new_self
                         .mem_cache
                         .lock()

src/config.rs

@@ -1,104 +1,50 @@
 use std::fmt::{Display, Formatter};
 use std::fs::{File, OpenOptions};
-use std::hint::unreachable_unchecked;
 use std::io::{ErrorKind, Write};
-use std::net::{IpAddr, SocketAddr};
+use std::net::IpAddr;
 use std::num::{NonZeroU16, NonZeroU64};
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 use std::str::FromStr;
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::AtomicBool;
 
 use clap::{crate_authors, crate_description, crate_version, Clap};
-use log::LevelFilter;
 use serde::{Deserialize, Serialize};
 use url::Url;
 
-use crate::units::{KilobitsPerSecond, Mebibytes, Port};
+use crate::units::{Kilobits, Mebibytes, Port};
 
 // Validate tokens is an atomic because it's faster than locking on rwlock.
 pub static VALIDATE_TOKENS: AtomicBool = AtomicBool::new(false);
+// We use an atomic here because it's better for us to not pass the config
+// everywhere.
+pub static SEND_SERVER_VERSION: AtomicBool = AtomicBool::new(false);
+
 pub static OFFLINE_MODE: AtomicBool = AtomicBool::new(false);
 
-pub fn load_config() -> Result<Config, serde_yaml::Error> {
-    // Load cli args first
-    let cli_args: CliArgs = CliArgs::parse();
-
-    // Load yaml file next
-    let config_file: Result<YamlArgs, _> = {
-        let config_path = cli_args
-            .config_path
-            .as_deref()
-            .unwrap_or_else(|| Path::new("./settings.yaml"));
-        match File::open(config_path) {
+pub fn load_config() -> Config {
+    const CONFIG_PATH: &str = "./settings.yaml";
+    let config_file: Result<YamlArgs, _> = match File::open(CONFIG_PATH) {
         Ok(file) => serde_yaml::from_reader(file),
         Err(e) if e.kind() == ErrorKind::NotFound => {
             let mut file = OpenOptions::new()
                 .write(true)
                 .create_new(true)
-                    .open(config_path)
+                .open(CONFIG_PATH)
                 .unwrap();
 
-                let default_config = include_str!("../settings.sample.yaml");
-                file.write_all(default_config.as_bytes()).unwrap();
-                serde_yaml::from_str(default_config)
-            }
-            e => panic!(
-                "Failed to open file at {}: {:?}",
-                config_path.to_string_lossy(),
-                e
-            ),
+            file.write_all(include_bytes!("../settings.sample.yaml"))
+                .unwrap();
+
+            return load_config();
         }
+        _ => panic!(),
     };
 
-    // generate config
-    let config = Config::from_cli_and_file(cli_args, config_file?);
-
-    // initialize globals
-    OFFLINE_MODE.store(
-        config
-            .unstable_options
-            .contains(&UnstableOptions::OfflineMode),
-        Ordering::Release,
-    );
-
-    Ok(config)
-}
-
-/// Represents a fully parsed config file.
-pub struct Config {
-    pub cache_type: CacheType,
-    pub cache_path: PathBuf,
-    pub shutdown_timeout: NonZeroU16,
-    pub log_level: LevelFilter,
-    pub client_secret: ClientSecret,
-    pub port: Port,
-    pub bind_address: SocketAddr,
-    pub external_address: Option<SocketAddr>,
-    pub ephemeral_disk_encryption: bool,
-    pub unstable_options: Vec<UnstableOptions>,
-    pub network_speed: KilobitsPerSecond,
-    pub disk_quota: Mebibytes,
-    pub memory_quota: Mebibytes,
-    pub override_upstream: Option<Url>,
-}
-
-impl Config {
-    fn from_cli_and_file(cli_args: CliArgs, file_args: YamlArgs) -> Self {
-        let log_level = match (cli_args.quiet, cli_args.verbose) {
-            (n, _) if n > 2 => LevelFilter::Off,
-            (2, _) => LevelFilter::Error,
-            (1, _) => LevelFilter::Warn,
-            // Use log level from file if no flags were provided to CLI
-            (0, 0) => file_args.extended_options.logging_level,
-            (_, 1) => LevelFilter::Debug,
-            (_, n) if n > 1 => LevelFilter::Trace,
-            // compiler can't figure it out
-            _ => unsafe { unreachable_unchecked() },
-        };
     todo!()
-    }
 }
 
+pub struct Config {}
+
 #[derive(Deserialize)]
 struct YamlArgs {
     // Naming is legacy
@@ -113,7 +59,7 @@ struct YamlArgs {
 struct YamlServerSettings {
     secret: ClientSecret,
     port: Port,
-    external_max_kilobits_per_second: KilobitsPerSecond,
+    external_max_kilobits_per_second: Kilobits,
     external_port: Option<Port>,
     graceful_shutdown_wait_seconds: Option<NonZeroU16>,
     hostname: Option<IpAddr>,
@@ -122,47 +68,29 @@ struct YamlServerSettings {
 
 // this intentionally does not implement display or debug
 #[derive(Deserialize, Serialize)]
-pub struct ClientSecret(String);
+struct ClientSecret(String);
 
 #[derive(Deserialize)]
 struct YamlExtendedOptions {
     memory_quota: Option<NonZeroU64>,
     #[serde(default)]
-    cache_type: CacheType,
+    send_server_string: bool,
+    #[serde(default)]
+    cache_type: YamlCacheType,
     #[serde(default)]
     ephemeral_disk_encryption: bool,
     #[serde(default)]
     enable_metrics: bool,
-    #[serde(default = "default_logging_level")]
-    logging_level: LevelFilter,
 }
 
-const fn default_logging_level() -> LevelFilter {
-    LevelFilter::Info
-}
-
-#[derive(Deserialize, Copy, Clone)]
-#[serde(rename_all = "snake_case")]
-pub enum CacheType {
+#[derive(Deserialize)]
+enum YamlCacheType {
     OnDisk,
     Lru,
     Lfu,
 }
 
-impl FromStr for CacheType {
-    type Err = String;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        match s {
-            "on_disk" => Ok(Self::OnDisk),
-            "lru" => Ok(Self::Lru),
-            "lfu" => Ok(Self::Lfu),
-            _ => Err(format!("Unknown option: {}", s)),
-        }
-    }
-}
-
-impl Default for CacheType {
+impl Default for YamlCacheType {
     fn default() -> Self {
         Self::OnDisk
     }
@@ -170,13 +98,13 @@ impl Default for CacheType {
 
 #[derive(Clap, Clone)]
 #[clap(version = crate_version!(), author = crate_authors!(), about = crate_description!())]
-struct CliArgs {
+pub struct CliArgs {
     /// The port to listen on.
     #[clap(short, long, default_value = "42069")]
     pub port: Port,
     /// How large, in bytes, the in-memory cache should be. Note that this does
     /// not include runtime memory usage.
-    #[clap(long)]
+    #[clap(long, conflicts_with = "low-memory")]
     pub memory_quota: Option<NonZeroU64>,
     /// How large, in bytes, the on-disk cache should be. Note that actual
     /// values may be larger for metadata information.
@@ -188,6 +116,16 @@ struct CliArgs {
     /// The network speed to advertise to Mangadex@Home control server.
     #[clap(long)]
     pub network_speed: NonZeroU64,
+    /// Whether or not to provide the Server HTTP header to clients. This is
+    /// useful for debugging, but is generally not recommended for security
+    /// reasons.
+    #[clap(long, takes_value = false)]
+    pub send_server_string: bool,
+    /// Changes the caching behavior to avoid buffering images in memory, and
+    /// instead use the filesystem as the buffer backing. This is useful for
+    /// clients in low (< 1GB) RAM environments.
+    #[clap(short, long, conflicts_with("memory-quota"), takes_value = false)]
+    pub low_memory: bool,
     /// Changes verbosity. Default verbosity is INFO, while increasing counts of
     /// verbose flags increases the verbosity to DEBUG and TRACE, respectively.
     #[clap(short, long, parse(from_occurrences))]
@@ -208,8 +146,6 @@ struct CliArgs {
     pub ephemeral_disk_encryption: bool,
     #[clap(short, long)]
     pub config_path: Option<PathBuf>,
-    #[clap(default_value = "on_disk")]
-    pub cache_type: CacheType,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -218,6 +154,10 @@ pub enum UnstableOptions {
     /// you know what you're dealing with.
     OverrideUpstream,
 
+    /// Use an LFU implementation for the in-memory cache instead of the default
+    /// LRU implementation.
+    UseLfu,
+
     /// Disables token validation. Don't use this unless you know the
     /// ramifications of this command.
     DisableTokenValidation,
@@ -235,6 +175,7 @@ impl FromStr for UnstableOptions {
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s {
             "override-upstream" => Ok(Self::OverrideUpstream),
+            "use-lfu" => Ok(Self::UseLfu),
             "disable-token-validation" => Ok(Self::DisableTokenValidation),
             "offline-mode" => Ok(Self::OfflineMode),
             "disable-tls" => Ok(Self::DisableTls),
@@ -247,6 +188,7 @@ impl Display for UnstableOptions {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::OverrideUpstream => write!(f, "override-upstream"),
+            Self::UseLfu => write!(f, "use-lfu"),
             Self::DisableTokenValidation => write!(f, "disable-token-validation"),
             Self::OfflineMode => write!(f, "offline-mode"),
             Self::DisableTls => write!(f, "disable-tls"),

src/main.rs

@@ -5,7 +5,8 @@
 use std::env::{self, VarError};
 use std::error::Error;
 use std::fmt::Display;
-use std::num::ParseIntError;
+use std::hint::unreachable_unchecked;
+use std::num::{NonZeroU64, ParseIntError};
 use std::process;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
@@ -15,8 +16,9 @@ use actix_web::rt::{spawn, time, System};
 use actix_web::web::{self, Data};
 use actix_web::{App, HttpResponse, HttpServer};
 use cache::{Cache, DiskCache};
-use config::Config;
-use log::{debug, error, info, warn};
+use clap::Clap;
+use config::CliArgs;
+use log::{debug, error, info, warn, LevelFilter};
 use parking_lot::RwLock;
 use rustls::{NoClientAuth, ServerConfig};
 use simple_logger::SimpleLogger;
@@ -27,7 +29,7 @@ use thiserror::Error;
 
 use crate::cache::mem::{Lfu, Lru};
 use crate::cache::{MemoryCache, ENCRYPTION_KEY};
-use crate::config::{CacheType, UnstableOptions, OFFLINE_MODE};
+use crate::config::{UnstableOptions, OFFLINE_MODE};
 use crate::state::DynamicServerCert;
 
 mod cache;
@@ -39,7 +41,12 @@ mod state;
 mod stop;
 mod units;
 
-const CLIENT_API_VERSION: usize = 31;
+#[macro_export]
+macro_rules! client_api_version {
+    () => {
+        "31"
+    };
+}
 
 #[derive(Error, Debug)]
 enum ServerError {
@@ -59,23 +66,46 @@ async fn main() -> Result<(), Box<dyn Error>> {
     // Config loading
     //
 
-    let config = config::load_config()?;
-    let memory_quota = config.memory_quota;
-    let disk_quota = config.disk_quota;
-    let cache_type = config.cache_type;
-    let cache_path = config.cache_path.clone();
-    let disable_tls = config
+    let config = config::load_config();
+
+    let cli_args = CliArgs::parse();
+    let port = cli_args.port;
+    let memory_max_size = cli_args
+        .memory_quota
+        .map(NonZeroU64::get)
+        .unwrap_or_default();
+    let disk_quota = cli_args.disk_quota;
+    let cache_path = cli_args.cache_path.clone();
+    let low_mem_mode = cli_args.low_memory;
+    let use_lfu = cli_args.unstable_options.contains(&UnstableOptions::UseLfu);
+    let disable_tls = cli_args
         .unstable_options
         .contains(&UnstableOptions::DisableTls);
-    let bind_address = config.bind_address;
+    OFFLINE_MODE.store(
+        cli_args
+            .unstable_options
+            .contains(&UnstableOptions::OfflineMode),
+        Ordering::Release,
+    );
 
     //
     // Logging and warnings
     //
 
-    SimpleLogger::new().with_level(config.log_level).init()?;
+    let log_level = match (cli_args.quiet, cli_args.verbose) {
+        (n, _) if n > 2 => LevelFilter::Off,
+        (2, _) => LevelFilter::Error,
+        (1, _) => LevelFilter::Warn,
+        (0, 0) => LevelFilter::Info,
+        (_, 1) => LevelFilter::Debug,
+        (_, n) if n > 1 => LevelFilter::Trace,
+        // compiler can't figure it out
+        _ => unsafe { unreachable_unchecked() },
+    };
 
-    if let Err(e) = print_preamble_and_warnings(&config) {
+    SimpleLogger::new().with_level(log_level).init()?;
+
+    if let Err(e) = print_preamble_and_warnings(&cli_args) {
         error!("{}", e);
         return Err(e);
     }
@@ -88,7 +118,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
     };
     let client_secret_1 = client_secret.clone();
 
-    if config.ephemeral_disk_encryption {
+    if cli_args.ephemeral_disk_encryption {
         info!("Running with at-rest encryption!");
         ENCRYPTION_KEY.set(gen_key()).unwrap();
     }
@@ -100,11 +130,18 @@ async fn main() -> Result<(), Box<dyn Error>> {
     let server = if OFFLINE_MODE.load(Ordering::Acquire) {
         ServerState::init_offline()
     } else {
-        ServerState::init(&client_secret, &config).await?
+        ServerState::init(&client_secret, &cli_args).await?
     };
     let data_0 = Arc::new(RwLockServerState(RwLock::new(server)));
     let data_1 = Arc::clone(&data_0);
 
+    // Rustls only supports TLS 1.2 and 1.3.
+    let tls_config = {
+        let mut tls_config = ServerConfig::new(NoClientAuth::new());
+        tls_config.cert_resolver = Arc::new(DynamicServerCert);
+        tls_config
+    };
+
     //
     // At this point, the server is ready to start, and starts the necessary
     // threads.
@@ -140,17 +177,18 @@ async fn main() -> Result<(), Box<dyn Error>> {
             loop {
                 interval.tick().await;
                 debug!("Sending ping!");
-                ping::update_server_state(&client_secret_1, &config, &mut data).await;
+                ping::update_server_state(&client_secret_1, &cli_args, &mut data).await;
             }
         });
     }
 
-    let memory_max_size = memory_quota.into();
-    let cache = DiskCache::new(disk_quota.into(), cache_path.clone()).await;
-    let cache: Arc<dyn Cache> = match cache_type {
-        CacheType::OnDisk => cache,
-        CacheType::Lru => MemoryCache::<Lfu, _>::new(cache, memory_max_size).await,
-        CacheType::Lfu => MemoryCache::<Lru, _>::new(cache, memory_max_size).await,
+    let cache = DiskCache::new(disk_quota, cache_path.clone()).await;
+    let cache: Arc<dyn Cache> = if low_mem_mode {
+        cache
+    } else if use_lfu {
+        MemoryCache::<Lfu, _>::new(cache, memory_max_size).await
+    } else {
+        MemoryCache::<Lru, _>::new(cache, memory_max_size).await
     };
 
     let cache_0 = Arc::clone(&cache);
@@ -176,17 +214,14 @@ async fn main() -> Result<(), Box<dyn Error>> {
     })
     .shutdown_timeout(60);
 
+    let server_bind_address = format!("0.0.0.0:{}", port);
     if disable_tls {
-        server.bind(bind_address)?.run().await?;
+        server.bind(server_bind_address)?.run().await?;
     } else {
-        // Rustls only supports TLS 1.2 and 1.3.
-        let tls_config = {
-            let mut tls_config = ServerConfig::new(NoClientAuth::new());
-            tls_config.cert_resolver = Arc::new(DynamicServerCert);
-            tls_config
-        };
-
-        server.bind_rustls(bind_address, tls_config)?.run().await?;
+        server
+            .bind_rustls(server_bind_address, tls_config)?
+            .run()
+            .await?;
     }
 
     // Waiting for us to finish sending stop message
@@ -218,7 +253,7 @@ impl Display for InvalidCombination {
 
 impl Error for InvalidCombination {}
 
-fn print_preamble_and_warnings(args: &Config) -> Result<(), Box<dyn Error>> {
+fn print_preamble_and_warnings(args: &CliArgs) -> Result<(), Box<dyn Error>> {
     println!(concat!(
         env!("CARGO_PKG_NAME"),
         " ",

src/ping.rs

@@ -1,3 +1,4 @@
+use std::num::NonZeroU64;
 use std::sync::atomic::Ordering;
 use std::{io::BufReader, sync::Arc};
 
@@ -11,13 +12,13 @@ use serde_repr::Deserialize_repr;
 use sodiumoxide::crypto::box_::PrecomputedKey;
 use url::Url;
 
-use crate::config::{Config, UnstableOptions, VALIDATE_TOKENS};
+use crate::config::{CliArgs, VALIDATE_TOKENS};
 use crate::state::{
     RwLockServerState, PREVIOUSLY_COMPROMISED, PREVIOUSLY_PAUSED, TLS_CERTS,
     TLS_PREVIOUSLY_CREATED, TLS_SIGNING_KEY,
 };
-use crate::units::{BytesPerSecond, Mebibytes, Port};
-use crate::CLIENT_API_VERSION;
+use crate::units::Port;
+use crate::{client_api_version, config::UnstableOptions};
 
 pub const CONTROL_CENTER_PING_URL: &str = "https://api.mangadex.network/ping";
 
@@ -25,20 +26,22 @@ pub const CONTROL_CENTER_PING_URL: &str = "https://api.mangadex.network/ping";
 pub struct Request<'a> {
     secret: &'a str,
     port: Port,
-    disk_space: Mebibytes,
-    network_speed: BytesPerSecond,
-    build_version: usize,
+    disk_space: u64,
+    network_speed: NonZeroU64,
+    build_version: u64,
     tls_created_at: Option<String>,
 }
 
 impl<'a> Request<'a> {
-    fn from_config_and_state(secret: &'a str, config: &Config) -> Self {
+    fn from_config_and_state(secret: &'a str, config: &CliArgs) -> Self {
         Self {
             secret,
             port: config.port,
             disk_space: config.disk_quota,
-            network_speed: config.network_speed.into(),
-            build_version: CLIENT_API_VERSION,
+            network_speed: config.network_speed,
+            build_version: client_api_version!()
+                .parse()
+                .expect("to parse the build version"),
             tls_created_at: TLS_PREVIOUSLY_CREATED
                 .get()
                 .map(|v| v.load().as_ref().clone()),
@@ -46,14 +49,17 @@ impl<'a> Request<'a> {
     }
 }
 
-impl<'a> From<(&'a str, &Config)> for Request<'a> {
-    fn from((secret, config): (&'a str, &Config)) -> Self {
+#[allow(clippy::fallible_impl_from)]
+impl<'a> From<(&'a str, &CliArgs)> for Request<'a> {
+    fn from((secret, config): (&'a str, &CliArgs)) -> Self {
         Self {
             secret,
             port: config.port,
             disk_space: config.disk_quota,
-            network_speed: config.network_speed.into(),
-            build_version: CLIENT_API_VERSION,
+            network_speed: config.network_speed,
+            build_version: client_api_version!()
+                .parse()
+                .expect("to parse the build version"),
             tls_created_at: None,
         }
     }
@@ -161,7 +167,7 @@ impl std::fmt::Debug for Tls {
     }
 }
 
-pub async fn update_server_state(secret: &str, cli: &Config, data: &mut Arc<RwLockServerState>) {
+pub async fn update_server_state(secret: &str, cli: &CliArgs, data: &mut Arc<RwLockServerState>) {
     let req = Request::from_config_and_state(secret, cli);
     let client = reqwest::Client::new();
     let resp = client.post(CONTROL_CENTER_PING_URL).json(&req).send().await;

src/routes.rs

@@ -22,14 +22,15 @@ use sodiumoxide::crypto::box_::{open_precomputed, Nonce, PrecomputedKey, NONCEBY
 use thiserror::Error;
 
 use crate::cache::{Cache, CacheKey, ImageMetadata, UpstreamError};
-use crate::config::{OFFLINE_MODE, VALIDATE_TOKENS};
+use crate::client_api_version;
+use crate::config::{OFFLINE_MODE, SEND_SERVER_VERSION, VALIDATE_TOKENS};
 use crate::metrics::{
     CACHE_HIT_COUNTER, CACHE_MISS_COUNTER, REQUESTS_DATA_COUNTER, REQUESTS_DATA_SAVER_COUNTER,
     REQUESTS_OTHER_COUNTER, REQUESTS_TOTAL_COUNTER,
 };
 use crate::state::RwLockServerState;
 
-const BASE64_CONFIG: base64::Config = base64::Config::new(base64::CharacterSet::UrlSafe, false);
+pub const BASE64_CONFIG: base64::Config = base64::Config::new(base64::CharacterSet::UrlSafe, false);
 
 static HTTP_CLIENT: Lazy<Client> = Lazy::new(|| {
     Client::builder()
@@ -40,6 +41,15 @@ static HTTP_CLIENT: Lazy<Client> = Lazy::new(|| {
         .expect("Client initialization to work")
 });
 
+const SERVER_ID_STRING: &str = concat!(
+    env!("CARGO_CRATE_NAME"),
+    " ",
+    env!("CARGO_PKG_VERSION"),
+    " (",
+    client_api_version!(),
+    ") - Conforming to spec revision b82043289",
+);
+
 enum ServerResponse {
     TokenValidationError(TokenValidationError),
     HttpResponse(HttpResponse),
@@ -216,6 +226,10 @@ fn push_headers(builder: &mut HttpResponseBuilder) -> &mut HttpResponseBuilder {
         .insert_header((CACHE_CONTROL, "public, max-age=1209600"))
         .insert_header(("Timing-Allow-Origin", "https://mangadex.org"));
 
+    if SEND_SERVER_VERSION.load(Ordering::Acquire) {
+        builder.insert_header(("Server", SERVER_ID_STRING));
+    }
+
     builder
 }
 

src/state.rs

@@ -1,7 +1,7 @@
 use std::str::FromStr;
 use std::sync::atomic::{AtomicBool, Ordering};
 
-use crate::config::{Config, UnstableOptions, OFFLINE_MODE, VALIDATE_TOKENS};
+use crate::config::{CliArgs, UnstableOptions, OFFLINE_MODE, SEND_SERVER_VERSION, VALIDATE_TOKENS};
 use crate::ping::{Request, Response, CONTROL_CENTER_PING_URL};
 use arc_swap::ArcSwap;
 use log::{error, info, warn};
@@ -45,13 +45,18 @@ pub enum ServerInitError {
 }
 
 impl ServerState {
-    pub async fn init(secret: &str, config: &Config) -> Result<Self, ServerInitError> {
+    pub async fn init(secret: &str, config: &CliArgs) -> Result<Self, ServerInitError> {
         let resp = reqwest::Client::new()
             .post(CONTROL_CENTER_PING_URL)
             .json(&Request::from((secret, config)))
             .send()
             .await;
 
+        if config.send_server_string {
+            warn!("Client will send Server header in responses. This is not recommended!");
+            SEND_SERVER_VERSION.store(true, Ordering::Release);
+        }
+
         match resp {
             Ok(resp) => match resp.json::<Response>().await {
                 Ok(Response::Ok(mut resp)) => {

src/units.rs

@@ -22,37 +22,18 @@ impl Display for Port {
     }
 }
 
-#[derive(Copy, Clone, Serialize, Deserialize, Default, Debug, Hash, Eq, PartialEq)]
+#[derive(Copy, Clone, Deserialize, Default, Debug, Hash, Eq, PartialEq)]
 pub struct Mebibytes(usize);
 
 impl Mebibytes {
-    pub const fn get(self) -> usize {
-        self.0
+    pub const fn as_bytes(&self) -> usize {
+        self.0 << 20
     }
-}
 
-pub struct Bytes(usize);
-
-impl Bytes {
     pub const fn get(&self) -> usize {
         self.0
     }
 }
 
-impl From<Mebibytes> for Bytes {
-    fn from(mib: Mebibytes) -> Self {
-        Self(mib.0 << 20)
-    }
-}
-
 #[derive(Copy, Clone, Deserialize, Debug, Hash, Eq, PartialEq)]
-pub struct KilobitsPerSecond(NonZeroU64);
-
-#[derive(Copy, Clone, Serialize, Debug, Hash, Eq, PartialEq)]
-pub struct BytesPerSecond(NonZeroU64);
-
-impl From<KilobitsPerSecond> for BytesPerSecond {
-    fn from(kbps: KilobitsPerSecond) -> Self {
-        Self(unsafe { NonZeroU64::new_unchecked(kbps.0.get() * 125) })
-    }
-}
+pub struct Kilobits(NonZeroU64);