allow downloading individual files from bundle

src/download.rs

@@ -1,3 +1,4 @@
+use core::fmt;
 use std::{
     cmp,
     fs::File,
@@ -14,6 +15,8 @@ use futures_core::{ready, Stream};
 use inotify::{Inotify, WatchMask};
 use log::trace;
 use pin_project_lite::pin_project;
+use serde::{de, Deserialize, Deserializer};
+use time::OffsetDateTime;
 use std::{os::unix::fs::MetadataExt, time::SystemTime};
 
 use actix_web::{
@@ -30,7 +33,55 @@ use actix_web::{
 
 use actix_files::HttpRange;
 
-use crate::store::StoredFile;
+use crate::{store::StoredFile, upload::UploadedFile};
+
+#[derive(Clone, Copy)]
+pub enum DownloadSelection {
+    One(usize),
+    All,
+}
+
+impl fmt::Display for DownloadSelection {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            DownloadSelection::All => write!(f, "all"),
+            DownloadSelection::One(n) => n.fmt(f),
+        }
+    }
+}
+
+struct SelectionVisitor;
+
+impl<'de> de::Visitor<'de> for SelectionVisitor {
+    type Value = DownloadSelection;
+
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(formatter, r#"a nonnegative integer or the string "all""#)
+    }
+
+    fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E> {
+        Ok(DownloadSelection::One(v as usize))
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+    where E: de::Error {
+        if v == "all" {
+            Ok(DownloadSelection::All)
+        } else if let Ok(n) = v.parse::<usize>() {
+            Ok(DownloadSelection::One(n))
+        } else {
+            Err(de::Error::invalid_value(de::Unexpected::Str(v), &self))
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for DownloadSelection {
+    fn deserialize<D: Deserializer<'de>>(
+        de: D
+    ) -> Result<DownloadSelection, D::Error> {
+        de.deserialize_any(SelectionVisitor)
+    }
+}
 
 // This is copied substantially from actix-files, with some tweaks
 
@@ -38,24 +89,64 @@ pub(crate) struct DownloadingFile {
     pub(crate) file: File,
     pub(crate) storage_path: PathBuf,
     pub(crate) info: StoredFile,
+    pub(crate) selection: DownloadSelection,
 }
 
 impl DownloadingFile {
+    fn selected(&self) -> Option<&UploadedFile> {
+        match self.selection {
+            DownloadSelection::All => None,
+            DownloadSelection::One(n) => Some(self.info.contents.as_ref()?.get(n)?),
+        }
+    }
+
+    fn name(&self) -> &str {
+        match self.selected() {
+            None => &self.info.name,
+            Some(f) => &f.name,
+        }
+    }
+
+    fn size(&self) -> u64 {
+        match self.selected() {
+            None => self.info.size,
+            Some(f) => f.size,
+        }
+    }
+
+    fn modtime(&self) -> OffsetDateTime {
+        match self.selected() {
+            None => self.info.modtime,
+            Some(f) => f.modtime,
+        }
+    }
+
+    fn baseline_offset(&self) -> u64 {
+        if let (DownloadSelection::One(n), Some(files)) = (self.selection, self.info.contents.as_ref()) {
+            crate::zip::file_data_offset(&files, n)
+        } else {
+            0
+        }
+    }
+
     fn etag(&self) -> EntityTag {
         let ino = self.file.metadata().map(|md| md.ino()).unwrap_or_default();
+        let modtime = self.modtime();
         EntityTag::new_strong(format!(
-            "{:x}:{:x}:{:x}:{:x}",
+            "{:x}:{}:{:x}:{:x}:{:x}",
             ino,
-            self.info.size,
-            self.info.modtime.unix_timestamp() as u64,
-            self.info.modtime.nanosecond(),
+            self.selection,
+            self.size(),
+            modtime.unix_timestamp() as u64,
+            modtime.nanosecond(),
         ))
     }
 
     /// Creates an `HttpResponse` with file as a streaming body.
     pub fn into_response(self, req: &HttpRequest) -> HttpResponse<BoxBody> {
+        let total_size = self.size();
         let etag = self.etag();
-        let last_modified = HttpDate::from(SystemTime::from(self.info.modtime));
+        let last_modified = HttpDate::from(SystemTime::from(self.modtime()));
 
         let precondition_failed = precondition_failed(req, &etag, &last_modified);
         let not_modified = not_modified(req, &etag, &last_modified);
@@ -68,14 +159,14 @@ impl DownloadingFile {
             header::CONTENT_DISPOSITION,
             ContentDisposition {
                 disposition: DispositionType::Attachment,
-                parameters: vec![DispositionParam::Filename(self.info.name)],
+                parameters: vec![DispositionParam::Filename(self.name().to_string())],
             },
         ));
         res.insert_header((header::LAST_MODIFIED, last_modified));
         res.insert_header((header::ETAG, etag));
         res.insert_header((header::ACCEPT_RANGES, "bytes"));
 
-        let mut length = self.info.size;
+        let mut length = total_size;
         let mut offset = 0;
 
         // check for range header
@@ -97,7 +188,7 @@ impl DownloadingFile {
                             "bytes {}-{}/{}",
                             offset,
                             offset + length - 1,
-                            self.info.size
+                            total_size,
                         ),
                     ));
                 } else {
@@ -118,9 +209,9 @@ impl DownloadingFile {
                 .map_into_boxed_body();
         }
 
-        let reader = new_live_reader(length, offset, self.file, self.storage_path);
+        let reader = new_live_reader(length, self.baseline_offset() + offset, self.file, self.storage_path);
 
-        if offset != 0 || length != self.info.size {
+        if offset != 0 || length != total_size {
             res.status(StatusCode::PARTIAL_CONTENT);
         }
 

src/main.rs

@@ -1,9 +1,10 @@
 mod download;
 mod store;
+mod timestamp;
 mod upload;
 mod zip;
 
-use std::{fmt::Debug, fs::File, path::PathBuf, str::FromStr};
+use std::{fmt::Debug, path::PathBuf, str::FromStr};
 
 use actix_files::NamedFile;
 use actix_web::{
@@ -11,11 +12,12 @@ use actix_web::{
     HttpServer, Responder,
 };
 use actix_web_actors::ws;
+use askama::Template;
 use bytesize::ByteSize;
 use log::{error, warn};
 use serde::{Deserialize, Serialize};
-use store::FileStore;
-use tokio::sync::RwLock;
+use store::{FileStore, StoredFile};
+use tokio::{fs::File, sync::RwLock};
 
 const APP_NAME: &str = "transbeam";
 
@@ -49,9 +51,19 @@ pub fn log_auth_failure(ip_addr: &str) {
     warn!("Incorrect authentication attempt from {}", ip_addr);
 }
 
+
 #[derive(Deserialize)]
 struct DownloadRequest {
     code: String,
+    download: Option<download::DownloadSelection>,
+}
+
+#[derive(Template)]
+#[template(path = "download.html")]
+struct DownloadInfo<'a> {
+    file: StoredFile,
+    code: &'a str,
+    available: u64,
 }
 
 #[get("/download")]
@@ -62,29 +74,52 @@ async fn handle_download(
 ) -> actix_web::Result<HttpResponse> {
     let code = &download.code;
     if !store::is_valid_storage_code(code) {
-        return download_not_found(req, data);
+        return not_found(req, data, true);
     }
     let info = data.file_store.read().await.lookup_file(code);
-    if let Some(info) = info {
-        let storage_path = data.config.storage_dir.join(code);
-        let file = File::open(&storage_path)?;
+    let info = if let Some(i) = info {
+        i
+    } else {
+        return not_found(req, data, true)
+    };
+
+    let storage_path = data.config.storage_dir.join(code);
+    let file = File::open(&storage_path).await?;
+    if let Some(selection) = download.download {
+        if let download::DownloadSelection::One(n) = selection {
+            if let Some(ref files) = info.contents {
+                if n >= files.len() {
+                    return not_found(req, data, false);
+                }
+            } else {
+                return not_found(req, data, false);
+            }
+        }
         Ok(download::DownloadingFile {
-            file,
+            file: file.into_std().await,
             storage_path,
             info,
+            selection,
         }
-        .into_response(&req))
+           .into_response(&req))
     } else {
-        download_not_found(req, data)
+        Ok(HttpResponse::Ok().body(DownloadInfo {
+            file: info,
+            code,
+            available: file.metadata().await?.len(),
+        }.render().unwrap()))
     }
 }
 
-fn download_not_found(
+fn not_found(
     req: HttpRequest,
     data: web::Data<AppState>,
+    report: bool,
 ) -> actix_web::Result<HttpResponse> {
-    let ip_addr = get_ip_addr(&req, data.config.reverse_proxy);
-    log_auth_failure(&ip_addr);
+    if report {
+        let ip_addr = get_ip_addr(&req, data.config.reverse_proxy);
+        log_auth_failure(&ip_addr);
+    }
     Ok(NamedFile::open(data.config.static_dir.join("404.html"))?
         .set_status_code(StatusCode::NOT_FOUND)
         .into_response(&req))

src/store.rs

@@ -10,12 +10,15 @@ use rand::{
     thread_rng, Rng,
 };
 use serde::{Deserialize, Serialize};
+use serde_with::skip_serializing_none;
 use time::OffsetDateTime;
 use tokio::{
     fs::File,
     io::{AsyncReadExt, AsyncWriteExt},
 };
 
+use crate::upload::UploadedFile;
+
 const STATE_FILE_NAME: &str = "files.json";
 const MAX_STORAGE_FILES: usize = 1024;
 
@@ -33,55 +36,16 @@ pub fn is_valid_storage_code(s: &str) -> bool {
         .all(|c| c.is_ascii_alphanumeric() || c == &b'-')
 }
 
+#[skip_serializing_none]
 #[derive(Clone, Deserialize, Serialize)]
 pub struct StoredFile {
     pub name: String,
     pub size: u64,
-    #[serde(with = "timestamp")]
+    #[serde(with = "crate::timestamp")]
     pub modtime: OffsetDateTime,
-    #[serde(with = "timestamp")]
+    #[serde(with = "crate::timestamp")]
     pub expiry: OffsetDateTime,
-}
-
-pub(crate) mod timestamp {
-    use core::fmt;
-
-    use serde::{de::Visitor, Deserializer, Serializer};
-    use time::OffsetDateTime;
-
-    pub(crate) fn serialize<S: Serializer>(
-        time: &OffsetDateTime,
-        ser: S,
-    ) -> Result<S::Ok, S::Error> {
-        ser.serialize_i64(time.unix_timestamp())
-    }
-
-    struct I64Visitor;
-
-    impl<'de> Visitor<'de> for I64Visitor {
-        type Value = i64;
-
-        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-            write!(formatter, "an integer")
-        }
-
-        fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E> {
-            Ok(v)
-        }
-
-        fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E> {
-            Ok(v as i64)
-        }
-    }
-
-    pub(crate) fn deserialize<'de, D: Deserializer<'de>>(
-        de: D,
-    ) -> Result<OffsetDateTime, D::Error> {
-        Ok(
-            OffsetDateTime::from_unix_timestamp(de.deserialize_i64(I64Visitor)?)
-                .unwrap_or_else(|_| OffsetDateTime::now_utc()),
-        )
-    }
+    pub contents: Option<Vec<UploadedFile>>,
 }
 
 async fn is_valid_entry(key: &str, info: &StoredFile, storage_dir: &Path) -> bool {

src/timestamp.rs

@@ -0,0 +1,38 @@
+use core::fmt;
+
+use serde::{de::Visitor, Deserializer, Serializer};
+use time::OffsetDateTime;
+
+pub(crate) fn serialize<S: Serializer>(
+    time: &OffsetDateTime,
+    ser: S,
+) -> Result<S::Ok, S::Error> {
+    ser.serialize_i64(time.unix_timestamp())
+}
+
+struct I64Visitor;
+
+impl<'de> Visitor<'de> for I64Visitor {
+    type Value = i64;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        write!(formatter, "an integer")
+    }
+
+    fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E> {
+        Ok(v)
+    }
+
+    fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E> {
+        Ok(v as i64)
+    }
+}
+
+pub(crate) fn deserialize<'de, D: Deserializer<'de>>(
+    de: D,
+) -> Result<OffsetDateTime, D::Error> {
+    Ok(
+        OffsetDateTime::from_unix_timestamp(de.deserialize_i64(I64Visitor)?)
+            .unwrap_or_else(|_| OffsetDateTime::now_utc()),
+    )
+}

src/upload.rs

@@ -93,9 +93,11 @@ impl Actor for Uploader {
 
 type Context = <Uploader as Actor>::Context;
 
+#[derive(Clone, Deserialize, Serialize)]
 pub struct UploadedFile {
     pub name: String,
     pub size: u64,
+    #[serde(with = "crate::timestamp")]
     pub modtime: OffsetDateTime,
 }
 
@@ -273,7 +275,7 @@ impl Uploader {
                 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);
+                    let zip_writer = super::zip::ZipGenerator::new(files.clone(), writer);
                     let size = zip_writer.total_size();
                     let download_filename = super::APP_NAME.to_owned()
                         + &now.format(FILENAME_DATE_FORMAT).unwrap()
@@ -293,6 +295,7 @@ impl Uploader {
                     size,
                     modtime,
                     expiry: OffsetDateTime::now_utc() + lifetime * time::Duration::DAY,
+                    contents: if files.len() > 1 { Some(files) } else { None },
                 };
                 let state = self.app_state.clone();
                 let storage_filename = self.storage_filename.clone();

src/zip.rs

@@ -37,6 +37,12 @@ fn file_entries_size(files: &[UploadedFile]) -> u64 {
     total
 }
 
+pub fn file_data_offset(files: &[UploadedFile], idx: usize) -> u64 {
+    file_entries_size(&files[..idx])
+        + LOCAL_HEADER_SIZE_MINUS_FILENAME
+        + files[idx].name.len() as u64
+}
+
 fn central_directory_size(files: &[UploadedFile]) -> u64 {
     let mut total = 0;
     for file in files.iter() {