added file expiration and fleshed out the API a bit

API.md

@@ -0,0 +1,53 @@
+# transbeam websocket api
+
+- After opening the connection, the client sends an upload manifest to
+  the server. This is a JSON object containing the following keys:
+  - `files`: a list of metadata objects for all the files to be
+    uploaded, in the exact order they will be sent.  This list must
+    contain at least 1 file and at most 256 files. Each file metadata
+    object has the following keys, all required:
+    - `name`: The name of the file. This will be sanitised on the
+      server side, but the sanitisation library isn't especially
+      restrictive; most Unicode code points will be allowed through
+      as-is.
+    - `size`: The exact size of the file, in bytes.
+    - `modtime`: The modification time of the file, as milliseconds
+      since the Unix epoch.
+  - `lifetime`: an integer number of days the files should be kept
+    for.
+
+- Once the server receives the metadata, it will respond with a
+  JSON-encoded object containing at least the field `type`, and
+  possibly other fields as well. The types of message, and their
+  associated extra fields if any, are as follows:
+  - `ready`: The server will accept the upload and is ready to receive
+    data.
+    - `code`: A code string that can be used to download the files,
+      starting now.
+  - `too_big`: The upload is rejected because the total size of the
+    files is bigger than the server is willing to accept.
+    - `max_size`: The maximum total upload size the server will
+      accept.  This is subject to change if the admin changes the
+      config, or if the server's storage space is filling up.
+  - `too_long`: The upload is rejected because the requested lifetime
+    is longer than the server will allow.
+    - `max_days`: The maximum number of days the client can request
+      files be kept for.
+  - `error`: A miscellaneous error has occurred.
+    - `details`: A string with more information about the error.
+
+  If the message type is anything other than `ready`, the connection
+  will be closed by the server.
+
+- If the server is ready to receive files, the client begins sending
+  chunks of data from the files, as raw binary blobs.  The client must
+  transmit each file's data in order from start to finish, and must
+  transmit the files in the same order they were listed in the
+  metadata.  The size of the chunks isn't currently specified, and
+  it's fine for a chunk to span the end of one file and the start of
+  the next.  After sending each chunk (that is, each complete
+  websocket message), the client must wait for the server to
+  acknowledge the chunk by sending back the string "ack", and then
+  send the next chunk if there is one. Once all chunks have been sent
+  and acknowledged, or once the server has sent a message other than
+  "ack" to indicate an error, the connection will be closed.

src/download.rs

@@ -30,14 +30,14 @@ use actix_web::{
 
 use actix_files::HttpRange;
 
-use crate::DownloadableFile;
+use crate::store::StoredFile;
 
 // This is copied substantially from actix-files, with some tweaks
 
 pub(crate) struct DownloadingFile {
     pub(crate) file: File,
     pub(crate) storage_path: PathBuf,
-    pub(crate) info: DownloadableFile,
+    pub(crate) info: StoredFile,
 }
 
 impl DownloadingFile {

src/main.rs

@@ -1,5 +1,5 @@
 mod download;
-mod state;
+mod store;
 mod upload;
 mod util;
 mod zip;
@@ -10,42 +10,13 @@ use actix_web::{
     get, middleware::Logger, web, App, HttpRequest, HttpResponse, HttpServer, Responder,
 };
 use actix_web_actors::ws;
-use serde::{Deserialize, Serialize};
+use log::error;
-use state::PersistentState;
+use store::FileStore;
-use time::OffsetDateTime;
 use tokio::sync::RwLock;
 
 const APP_NAME: &str = "transbeam";
 
-pub struct UploadedFile {
+type AppData = web::Data<RwLock<FileStore>>;
-    name: String,
-    size: u64,
-    modtime: OffsetDateTime,
-}
-
-impl UploadedFile {
-    fn new(name: &str, size: u64, modtime: OffsetDateTime) -> Self {
-        Self {
-            name: sanitise_file_name::sanitise(name),
-            size,
-            modtime,
-        }
-    }
-}
-
-#[derive(Clone, Deserialize, Serialize)]
-pub struct DownloadableFile {
-    name: String,
-    size: u64,
-    #[serde(with = "state::timestamp")]
-    modtime: OffsetDateTime,
-}
-
-type AppData = web::Data<RwLock<PersistentState>>;
-
-fn storage_dir() -> PathBuf {
-    PathBuf::from(std::env::var("STORAGE_DIR").unwrap_or_else(|_| String::from("storage")))
-}
 
 #[get("/download/{file_code}")]
 async fn handle_download(
@@ -60,7 +31,7 @@ async fn handle_download(
     let data = data.read().await;
     let info = data.lookup_file(&file_code);
     if let Some(info) = info {
-        let storage_path = storage_dir().join(file_code);
+        let storage_path = store::storage_dir().join(file_code);
         let file = File::open(&storage_path)?;
         Ok(download::DownloadingFile {
             file,
@@ -82,7 +53,8 @@ async fn handle_upload(req: HttpRequest, stream: web::Payload, data: AppData) ->
 async fn main() -> std::io::Result<()> {
     env_logger::init();
 
-    let data: AppData = web::Data::new(RwLock::new(PersistentState::load().await?));
+    let data: AppData = web::Data::new(RwLock::new(FileStore::load().await?));
+    start_reaper(data.clone());
 
     let static_dir =
         PathBuf::from(std::env::var("STATIC_DIR").unwrap_or_else(|_| String::from("static")));
@@ -104,3 +76,16 @@ async fn main() -> std::io::Result<()> {
     .await?;
     Ok(())
 }
+
+fn start_reaper(data: AppData) {
+    std::thread::spawn(move || {
+        actix_web::rt::System::new().block_on(async {
+            loop {
+                actix_web::rt::time::sleep(core::time::Duration::from_secs(86400)).await;
+                if let Err(e) = data.write().await.remove_expired_files().await {
+                    error!("Error reaping expired files: {}", e);
+                }
+            }
+        });
+    });
+}

src/store.rs

@@ -1,14 +1,50 @@
-use std::{collections::HashMap, io::ErrorKind};
+use std::{collections::HashMap, io::ErrorKind, path::PathBuf, str::FromStr};
 
 use log::{debug, error, info, warn};
+use serde::{Deserialize, Serialize};
+use time::OffsetDateTime;
 use tokio::{
     fs::File,
     io::{AsyncReadExt, AsyncWriteExt},
 };
 
-use crate::{storage_dir, DownloadableFile};
-
 const STATE_FILE_NAME: &str = "files.json";
+const DEFAULT_STORAGE_DIR: &str = "storage";
+const DEFAULT_MAX_LIFETIME: u32 = 30;
+const GIGA: u64 = 1024*1024*1024;
+const DEFAULT_MAX_SINGLE_SIZE: u64 = 16*GIGA;
+const DEFAULT_MAX_TOTAL_SIZE: u64 = 64*GIGA;
+
+
+pub(crate) fn storage_dir() -> PathBuf {
+    PathBuf::from(std::env::var("STORAGE_DIR").unwrap_or_else(|_| String::from(DEFAULT_STORAGE_DIR)))
+}
+
+fn parse_env_var<T: FromStr>(var: &str, default: T) -> T {
+    std::env::var(var).ok().and_then(|val| val.parse::<T>().ok()).unwrap_or(default)
+}
+
+pub(crate) fn max_lifetime() -> u32 {
+    parse_env_var("TRANSBEAM_MAX_LIFETIME", DEFAULT_MAX_LIFETIME)
+}
+
+pub(crate) fn max_single_size() -> u64 {
+    parse_env_var("TRANSBEAM_MAX_SINGLE_FILE_SIZE", DEFAULT_MAX_SINGLE_SIZE)
+}
+
+pub(crate) fn max_total_size() -> u64 {
+    parse_env_var("TRANSBEAM_MAX_TOTAL_FILE_SIZE", DEFAULT_MAX_TOTAL_SIZE)
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+pub struct StoredFile {
+    pub name: String,
+    pub size: u64,
+    #[serde(with = "timestamp")]
+    pub modtime: OffsetDateTime,
+    #[serde(with = "timestamp")]
+    pub expiry: OffsetDateTime,
+}
 
 pub(crate) mod timestamp {
     use core::fmt;
@@ -51,11 +87,12 @@ pub(crate) mod timestamp {
     }
 }
 
-async fn is_valid_entry(key: &str, info: &DownloadableFile) -> bool {
+async fn is_valid_entry(key: &str, info: &StoredFile) -> bool {
-    if !crate::util::is_ascii_alphanumeric(key) {
+    if info.expiry < OffsetDateTime::now_utc() {
-        error!("Invalid key in persistent storage: {}", key);
+        info!("File {} has expired", key);
         return false;
     }
+
     let file = if let Ok(f) = File::open(storage_dir().join(&key)).await {
         f
     } else {
@@ -81,24 +118,31 @@ async fn is_valid_entry(key: &str, info: &DownloadableFile) -> bool {
     true
 }
 
-pub(crate) struct PersistentState(HashMap<String, DownloadableFile>);
+pub(crate) struct FileStore(HashMap<String, StoredFile>);
-impl PersistentState {
+impl FileStore {
     pub(crate) async fn load() -> std::io::Result<Self> {
         let open_result = File::open(storage_dir().join(STATE_FILE_NAME)).await;
         match open_result {
             Ok(mut f) => {
                 let mut buf = String::new();
                 f.read_to_string(&mut buf).await?;
-                let map: HashMap<String, DownloadableFile> = serde_json::from_str(&buf)?;
+                let map: HashMap<String, StoredFile> = serde_json::from_str(&buf)?;
                 info!("Loaded {} file entries from persistent storage", map.len());
-                let mut filtered: HashMap<String, DownloadableFile> = HashMap::new();
+                let mut filtered: HashMap<String, StoredFile> = HashMap::new();
                 for (key, info) in map.into_iter() {
+                    // Handle this case separately, because we don't
+                    // want to try to delete it if it's not the sort
+                    // of path we're expecting
+                    if !crate::util::is_ascii_alphanumeric(&key) {
+                        error!("Invalid key in persistent storage: {}", key);
+                        continue;
+                    }
                     if is_valid_entry(&key, &info).await {
                         filtered.insert(key, info);
                     } else {
-                        info!("Deleting invalid file {}", key);
+                        info!("Deleting file {}", key);
                         if let Err(e) = tokio::fs::remove_file(storage_dir().join(&key)).await {
-                            warn!("Failed to delete invalid file {}: {}", key, e);
+                            warn!("Failed to delete file {}: {}", key, e);
                         }
                     }
                 }
@@ -116,6 +160,10 @@ impl PersistentState {
         }
     }
 
+    fn total_size(&self) -> u64 {
+        self.0.iter().fold(0, |acc, (_, f)| acc + f.size)
+    }
+
     async fn save(&mut self) -> std::io::Result<()> {
         info!("saving updated state: {} entries", self.0.len());
         File::create(storage_dir().join(STATE_FILE_NAME))
@@ -124,16 +172,22 @@ impl PersistentState {
             .await
     }
 
+    /// Attempts to add a file to the store. Returns an I/O error if
+    /// something's broken, or a u64 of the maximum allowed file size
+    /// if the file was too big, or a unit if everything worked.
     pub(crate) async fn add_file(
         &mut self,
         key: String,
-        file: DownloadableFile,
+        file: StoredFile,
-    ) -> std::io::Result<()> {
+    ) -> std::io::Result<Result<(), u64>> {
+        let remaining_size = max_total_size().saturating_sub(self.total_size());
+        let allowed_size = std::cmp::min(remaining_size, max_single_size());
+        if file.size > allowed_size { return Ok(Err(allowed_size)); }
         self.0.insert(key, file);
-        self.save().await
+        self.save().await.map(Ok)
     }
 
-    pub(crate) fn lookup_file(&self, key: &str) -> Option<DownloadableFile> {
+    pub(crate) fn lookup_file(&self, key: &str) -> Option<StoredFile> {
         self.0.get(key).cloned()
     }
 
@@ -142,4 +196,20 @@ impl PersistentState {
         self.0.remove(key);
         self.save().await
     }
+
+    pub(crate) async fn remove_expired_files(&mut self) -> std::io::Result<()> {
+        info!("Checking for expired files");
+        let now = OffsetDateTime::now_utc();
+        for (key, file) in std::mem::replace(&mut self.0, HashMap::new()).into_iter() {
+            if file.expiry > now {
+                self.0.insert(key, file);
+            } else {
+                info!("Deleting expired file {}", key);
+                if let Err(e) = tokio::fs::remove_file(storage_dir().join(&key)).await {
+                    warn!("Failed to delete expired file {}: {}", key, e);
+                }
+            }
+        }
+        self.save().await
+    }
 }

src/upload.rs

@@ -6,10 +6,10 @@ use actix_web_actors::ws::{self, CloseCode};
 use bytes::Bytes;
 use log::{debug, error, info, trace};
 use rand::distributions::{Alphanumeric, DistString};
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
 
-use crate::{storage_dir, DownloadableFile, UploadedFile};
+use crate::store::{storage_dir, StoredFile, self};
 
 const MAX_FILES: usize = 256;
 const FILENAME_DATE_FORMAT: &[time::format_description::FormatItem] =
@@ -31,6 +31,10 @@ enum Error {
     NoFiles,
     #[error("Number of files submitted by client exceeded the maximum limit")]
     TooManyFiles,
+    #[error("Requested lifetime was too long")]
+    TooLong,
+    #[error("Upload size was too large, can be at most {0} bytes")]
+    TooBig(u64),
     #[error("Websocket was closed by client before completing transfer")]
     ClosedEarly(Option<CloseReason>),
     #[error("Client sent more data than they were supposed to")]
@@ -40,15 +44,17 @@ enum Error {
 impl Error {
     fn close_code(&self) -> CloseCode {
         match self {
-            Self::Parse(_) => CloseCode::Invalid,
+            Self::Storage(_)
-            Self::Storage(_) => CloseCode::Error,
+                | Self::TimeFormat(_) => CloseCode::Error,
-            Self::TimeFormat(_) => CloseCode::Error,
+            Self::Parse(_)
-            Self::DuplicateFilename => CloseCode::Policy,
+                | Self::UnexpectedMessageType
-            Self::UnexpectedMessageType => CloseCode::Invalid,
+                | Self::ClosedEarly(_)
-            Self::NoFiles => CloseCode::Policy,
+                | Self::UnexpectedExtraData => CloseCode::Invalid,
-            Self::TooManyFiles => CloseCode::Policy,
+            Self::DuplicateFilename
-            Self::ClosedEarly(_) => CloseCode::Invalid,
+                | Self::NoFiles
-            Self::UnexpectedExtraData => CloseCode::Invalid,
+                | Self::TooManyFiles
+                | Self::TooLong
+                | Self::TooBig(_) => CloseCode::Policy,
         }
     }
 }
@@ -64,7 +70,7 @@ impl Uploader {
     pub(crate) fn new(app_data: super::AppData) -> Self {
         Self {
             writer: None,
-            storage_filename: String::new(),
+            storage_filename: Alphanumeric.sample_string(&mut rand::thread_rng(), 8),
             app_data,
             bytes_remaining: 0,
         }
@@ -75,6 +81,22 @@ impl Actor for Uploader {
     type Context = ws::WebsocketContext<Self>;
 }
 
+pub struct UploadedFile {
+    pub name: String,
+    pub size: u64,
+    pub modtime: OffsetDateTime,
+}
+
+impl UploadedFile {
+    fn new(name: &str, size: u64, modtime: OffsetDateTime) -> Self {
+        Self {
+            name: sanitise_file_name::sanitise(name),
+            size,
+            modtime,
+        }
+    }
+}
+
 #[derive(Debug, Deserialize)]
 struct RawUploadedFile {
     name: String,
@@ -93,6 +115,31 @@ impl RawUploadedFile {
     }
 }
 
+#[derive(Deserialize)]
+struct UploadManifest {
+    files: Vec<RawUploadedFile>,
+    lifetime: u32,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "snake_case", tag = "type")]
+enum ServerMessage {
+    Ready { code: String },
+    TooBig { max_size: u64 },
+    TooLong { max_days: u32 },
+    Error { details: String },
+}
+
+impl From<&Error> for ServerMessage {
+    fn from(e: &Error) -> Self {
+        match e {
+            Error::TooBig(max_size) => ServerMessage::TooBig { max_size: *max_size },
+            Error::TooLong => ServerMessage::TooLong { max_days: store::max_lifetime() },
+            _ => ServerMessage::Error { details: e.to_string() },
+        }
+    }
+}
+
 fn stop_and_flush<T>(_: T, u: &mut Uploader, ctx: &mut <Uploader as Actor>::Context) {
     ctx.stop();
     if let Some(w) = u.writer.as_mut() {
@@ -115,12 +162,7 @@ impl StreamHandler<Result<ws::Message, ws::ProtocolError>> for Uploader {
 
         match self.handle_message(msg, ctx) {
             Err(e) => {
-                error!("{}", e);
+                self.notify_error_and_cleanup(e, ctx);
-                ctx.close(Some(ws::CloseReason {
-                    code: e.close_code(),
-                    description: Some(e.to_string()),
-                }));
-                self.cleanup_after_error(ctx);
             }
             Ok(true) => {
                 info!("Finished uploading data");
@@ -140,6 +182,16 @@ fn ack(ctx: &mut <Uploader as Actor>::Context) {
 }
 
 impl Uploader {
+    fn notify_error_and_cleanup(&mut self, e: Error, ctx: &mut <Self as Actor>::Context) {
+        error!("{}", e);
+        ctx.text(serde_json::to_string(&ServerMessage::from(&e)).unwrap());
+        ctx.close(Some(ws::CloseReason {
+            code: e.close_code(),
+            description: Some(e.to_string()),
+        }));
+        self.cleanup_after_error(ctx);
+    }
+
     fn handle_message(
         &mut self,
         msg: ws::Message,
@@ -151,12 +203,18 @@ impl Uploader {
                 if self.writer.is_some() {
                     return Err(Error::UnexpectedMessageType);
                 }
-                let raw_files: Vec<RawUploadedFile> = serde_json::from_slice(text.as_bytes())?;
+                let UploadManifest { files: raw_files, lifetime, } = serde_json::from_slice(text.as_bytes())?;
+                if lifetime > store::max_lifetime() {
+                    return Err(Error::TooLong);
+                }
                 info!("Received file list: {} files", raw_files.len());
                 debug!("{:?}", raw_files);
                 if raw_files.len() > MAX_FILES {
                     return Err(Error::TooManyFiles);
                 }
+                if raw_files.is_empty() {
+                    return Err(Error::NoFiles);
+                }
                 let mut filenames: HashSet<String> = HashSet::new();
                 let mut files = Vec::new();
                 for raw_file in raw_files.iter() {
@@ -172,18 +230,13 @@ impl Uploader {
                     self.bytes_remaining += file.size;
                     files.push(file);
                 }
-                if files.is_empty() {
+                let storage_path = storage_dir().join(self.storage_filename.clone());
-                    return Err(Error::NoFiles);
-                }
-                let storage_filename = Alphanumeric.sample_string(&mut rand::thread_rng(), 8);
-                self.storage_filename = storage_filename.clone();
-                let storage_path = storage_dir().join(storage_filename.clone());
                 info!("storing to: {:?}", storage_path);
                 let writer = File::options()
                     .write(true)
                     .create_new(true)
                     .open(&storage_path)?;
-                let (writer, downloadable_file): (Box<dyn Write>, _) = if files.len() > 1 {
+                let (writer, name, size, modtime): (Box<dyn Write>,_,_,_) = if files.len() > 1 {
                     info!("Wrapping in zipfile generator");
                     let now = OffsetDateTime::now_utc();
                     let zip_writer = super::zip::ZipGenerator::new(files, writer);
@@ -192,33 +245,40 @@ impl Uploader {
                         super::APP_NAME.to_owned() + &now.format(FILENAME_DATE_FORMAT)? + ".zip";
                     (
                         Box::new(zip_writer),
-                        DownloadableFile {
+                        download_filename,
-                            name: download_filename,
                         size,
-                            modtime: now,
+                        now,
-                        },
                     )
                 } else {
                     (
                         Box::new(writer),
-                        DownloadableFile {
+                        files[0].name.clone(),
-                            name: files[0].name.clone(),
+                        files[0].size,
-                            size: files[0].size,
+                        files[0].modtime,
-                            modtime: files[0].modtime,
-                        },
                     )
                 };
                 self.writer = Some(writer);
+                let stored_file = StoredFile {
+                    name,
+                    size,
+                    modtime,
+                    expiry: OffsetDateTime::now_utc() + lifetime*time::Duration::DAY,
+                };
                 let data = self.app_data.clone();
+                let storage_filename = self.storage_filename.clone();
                 ctx.spawn(actix::fut::wrap_future(async move {
                     debug!("Spawned future to add entry {} to state", storage_filename);
                     data.write()
                         .await
-                        .add_file(storage_filename, downloadable_file)
+                        .add_file(storage_filename, stored_file)
                         .await
-                        .unwrap();
+                }).map(|res, u: &mut Self, ctx: &mut <Self as Actor>::Context| {
+                    match res {
+                        Ok(Ok(())) => ctx.text(serde_json::to_string(&ServerMessage::Ready { code: u.storage_filename.clone() }).unwrap()),
+                        Ok(Err(size)) => u.notify_error_and_cleanup(Error::TooBig(size), ctx),
+                        Err(e) => u.notify_error_and_cleanup(Error::from(e), ctx)
+                    }
                 }));
-                ctx.text(self.storage_filename.as_str());
             }
             ws::Message::Binary(data) | ws::Message::Continuation(Item::Last(data)) => {
                 let result = self.handle_data(data)?;

src/zip.rs

@@ -4,7 +4,7 @@ use crc32fast::Hasher;
 use log::debug;
 use time::OffsetDateTime;
 
-use crate::UploadedFile;
+use crate::upload::UploadedFile;
 
 const SIGNATURE_SIZE: u64 = 4;
 const SHARED_FIELDS_SIZE: u64 = 26;

static/index.html

@@ -18,6 +18,17 @@
       <noscript>This page requires Javascript :(</noscript>
 
       <button id="upload">Upload</button>
+      <div id="lifetime_container" style="display: none;">
+        <label>
+          Keep files for:
+          <select id="lifetime">
+            <option value="1">1 day</option>
+            <option value="7">1 week</option>
+            <option value="14" selected>2 weeks</option>
+            <option value="30">1 month</option>
+          </select>
+        </label>
+      </div>
       <div id="download_link_container" style="display: none;">
         <div id="download_link_main">
           <div>Download link: <span id="download_link"></span></div><div class="copy_button"></div>

static/transbeam.css

@@ -133,6 +133,10 @@ button:disabled, input:disabled + .fake_button {
     cursor: not-allowed;
 }
 
+#lifetime_container {
+    margin-top: 10px;
+}
+
 #footer {
     margin-top: 30px;
 }

static/transbeam.js

@@ -8,6 +8,9 @@ const fileInputMessage = document.getElementById('file_input_message');
 const fileListContainer = document.getElementById('file_list_container');
 const fileList = document.getElementById('file_list');
 
+const lifetimeContainer = document.getElementById('lifetime_container');
+const lifetimeInput = document.getElementById('lifetime');
+
 const uploadButton = document.getElementById('upload');
 
 const downloadLinkContainer = document.getElementById('download_link_container');
@@ -27,13 +30,13 @@ let byteIndex = 0;
 let bytesSent = 0;
 let totalBytes = 0;
 
-function sendMetadata() {
+function sendManifest(lifetime) {
-    const metadata = files.map((file) => ({
+    const fileMetadata = files.map((file) => ({
         name: file.name,
         size: file.size,
         modtime: file.lastModified,
     }));
-    socket.send(JSON.stringify(metadata));
+    socket.send(JSON.stringify({ lifetime, files: fileMetadata }));
 }
 
 function finishSending() {
@@ -95,11 +98,13 @@ function updateFiles() {
         fileInputMessage.textContent = 'Select files to upload...';
         fileListContainer.style.display = 'none';
         uploadButton.style.display = 'none';
+        lifetimeContainer.style.display = 'none';
     } else {
         fileInputMessage.textContent = 'Select more files to upload...';
         fileListContainer.style.display = '';
         uploadButton.textContent = `Upload ${files.length} file${files.length > 1 ? 's' : ''} (${displaySize(totalBytes)})`;
         uploadButton.style.display = '';
+        lifetimeContainer.style.display = '';
     }
     fileInput.disabled = (files.length >= MAX_FILES);
 }
@@ -156,20 +161,25 @@ fileInput.addEventListener('input', (e) => {
 uploadButton.addEventListener('click', (e) => {
     if (files.length === 0) { return; }
 
+    const lifetime = parseInt(lifetimeInput.value);
+    lifetimeContainer.remove();
     fileInputContainer.remove();
     for (const button of Array.from(document.getElementsByTagName('button')).concat(...document.getElementsByClassName('file_delete'))) {
         button.remove();
     }
 
     socket = new WebSocket(`${window.location.protocol === 'http:' ? 'ws' : 'wss'}://${window.location.host}/upload`);
-    socket.addEventListener('open', sendMetadata);
+    socket.addEventListener('open', () => sendManifest(lifetime));
     socket.addEventListener('message', (msg) => {
-        if (bytesSent === 0 && msg.data.match(/^[A-Za-z0-9]+$/)) {
+        if (bytesSent === 0) {
-            downloadLink.textContent = `${window.location.origin}/download/${msg.data}`;
+            const reply = JSON.parse(msg.data);
+            if (reply.type === 'ready' && reply.code.match(/^[A-Za-z0-9]+$/)) {
+                downloadLink.textContent = `${window.location.origin}/download/${reply.code}`;
                 downloadLinkContainer.style.display = '';
                 updateProgress();
                 progressContainer.style.display = '';
                 sendData();
+            }
         } else if (msg.data === 'ack') {
             sendData();
         }