File Size Limit Middleware

Middleware that provides size limits for uploaded files in requests.

Use Cases

Size Limiter is primarily used in the following scenarios:

Preventing users from uploading files that are too large and consuming server resources
Avoiding malicious attacks where attackers upload large amounts of data causing server memory overflow
Setting different request size limit policies for different API endpoints
Improving the efficiency and stability of server request processing

Example Code

main.rs

Cargo.toml

size-limiter/src/main.rs

use std::fs::create_dir_all;
use std::path::Path;

use salvo::prelude::*;

#[handler]
async fn index(res: &mut Response) {
    res.render(Text::Html(INDEX_HTML));
}
#[handler]
async fn upload(req: &mut Request, res: &mut Response) {
    let file = req.file("file").await;
    if let Some(file) = file {
        let dest = format!("temp/{}", file.name().unwrap_or("file"));
        tracing::debug!(dest, "upload file");
        if let Err(e) = std::fs::copy(file.path(), Path::new(&dest)) {
            res.status_code(StatusCode::INTERNAL_SERVER_ERROR);
            res.render(Text::Plain(format!("file not found in request: {e}")));
        } else {
            res.render(Text::Plain(format!("File uploaded to {dest}")));
        }
    } else {
        res.status_code(StatusCode::BAD_REQUEST);
        res.render(Text::Plain("file not found in request"));
    }
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt().init();

    create_dir_all("temp").unwrap();
    let router = Router::new()
        .get(index)
        .push(
            Router::new()
                .hoop(max_size(1024 * 1024 * 10))
                .path("limited")
                .post(upload),
        )
        .push(Router::with_path("unlimit").post(upload));

    let acceptor = TcpListener::new("0.0.0.0:5800").bind().await;
    Server::new(acceptor).serve(router).await;
}

static INDEX_HTML: &str = r#"<!DOCTYPE html>
<html>
    <head>
        <title>Upload file</title>
    </head>
    <body>
        <h1>Upload file</h1>
        <form action="/unlimit" method="post" enctype="multipart/form-data">
            <h3>Unlimit</h3>
            <input type="file" name="file" />
            <input type="submit" value="upload" />
        </form>
        <form action="/limited" method="post" enctype="multipart/form-data">
            <h3>Limited 10MiB</h3>
            <input type="file" name="file" />
            <input type="submit" value="upload" />
        </form>
    </body>
</html>
"#;

On this page

#File Size Limit Middleware

#Use Cases

File Size Limit Middleware

Use Cases