Update

Cargo.lock

@@ -61,6 +61,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
+
 [[package]]
 name = "bitflags"
 version = "2.10.0"
@@ -164,8 +170,10 @@ dependencies = [
 name = "header_proxy"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "clap",
  "env_logger",
+ "httparse",
  "lazy_static",
  "log",
  "rand",
@@ -178,6 +186,12 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "httparse"
+version = "1.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.2"

Cargo.toml

@@ -10,3 +10,5 @@ clap = { version = "4.5.53", features = ["env", "derive"] }
 tokio = { version = "1.48.0", features = ["full"] }
 rand = "0.9.2"
 lazy_static = "1.5.0"
+httparse = "1.10.1"
+anyhow = "1.0.100"

Dockerfile

@@ -0,0 +1,10 @@
+FROM debian:bookworm-slim
+
+RUN apt-get update \
+  && apt-get install -y libcurl4 \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY header_proxy /usr/local/bin/header_proxy
+
+ENTRYPOINT ["/usr/local/bin/header_proxy"]
+

build_docker_image.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+cargo build --release
+
+TEMP_DIR=$(mktemp -d)
+cp target/release/header_proxy "$TEMP_DIR"
+
+docker build -f Dockerfile "$TEMP_DIR" -t pierre42100/header_proxy
+
+rm -r $TEMP_DIR
+

src/main.rs

@@ -1,33 +1,28 @@
 use clap::Parser;
 use rand::distr::{Alphanumeric, SampleString};
-use rustls_pki_types::ServerName;
 use std::error::Error;
-use std::fs::OpenOptions;
-use std::io::Write;
-use std::path::Path;
-use std::sync::Arc;
-use std::time::{SystemTime, UNIX_EPOCH};
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpListener;
 use tokio::net::TcpStream;
-use tokio_rustls::TlsConnector;
-use tokio_rustls::rustls::{ClientConfig, RootCertStore};
 
 /// Simple program that redirect requests to a given server in request
 #[derive(Parser, Debug)]
 #[command(version, about, long_about = None)]
 struct Args {
     /// The address the server will listen to
-    #[arg(short, long, default_value = "0.0.0.0:8000")]
+    #[arg(short, long, env, default_value = "0.0.0.0:8000")]
     listen_address: String,
 
     /// The name of the header that contain target host and port
-    #[arg(short, long, default_value = "x-target-host")]
+    #[arg(short, long, env, default_value = "x-target-host")]
     target_host_port_header: String,
 
-    /// Name of optional header that contains path to add to the request
+    /// Name of optional header that contains path to add to the request.
-    #[arg(short, long, default_value = "x-path-prefix")]
+    ///
-    path_prefix_heder: String,
+    /// If this value is defined, all clients packets are inspected in research for path to
+    /// manipulate
+    #[arg(short, long, env)]
+    path_prefix_header: Option<String>,
 }
 
 lazy_static::lazy_static! {
@@ -56,61 +51,95 @@ async fn main() -> Result<(), Box<dyn Error>> {
         tokio::spawn(async move {
             let conn_id = rand_str(5);
 
-            log::debug!(
+            log::info!(
-                "Handle new connection from {}",
+                "[{conn_id}] Handle new connection from {}",
                 client_socket.peer_addr().unwrap()
             );
 
-
-            let stream = TcpStream::connect(TODO)
-                .await
-                .expect("Failed to connect to upstream");
-            let mut upstream = connector
-                .connect(dnsname, stream)
-                .await
-                .expect("Failed to establish TLS connection");
-
             let (mut client_read, mut client_write) = client_socket.split();
-
+            let mut buf_client = [0u8; 10000];
-            let mut buf_client = [0u8; 1024];
             let mut buf_server = [0u8; 1024];
 
-            let mut modified_headers = false;
+            // Perform first read operation manually to manipulate path and determine target server
+            let mut total = 0;
+            let headers_processed = loop {
+                let count = match client_read.read(&mut buf_client[total..]).await {
+                    Ok(count) => count,
+                    Err(e) => {
+                        log::error!(
+                            "[{conn_id}]  Failed to read initial data from client, closing connection! {e}"
+                        );
+                        return;
+                    }
+                };
 
+                if count == 0 {
+                    log::error!("[{conn_id}] read from client count is null, cannot continue!");
+                    let _ = client_write.write_all(ERR_NOT_PROXIFIALBE).await;
+                    return;
+                }
+
+                total += count;
+
+                match process_headers(&buf_client[..total]) {
+                    Ok(None) => {
+                        log::debug!("[{conn_id}] Insufficient amount of data, need to continue");
+                        continue;
+                    }
+                    Ok(Some(res)) => break res,
+                    Err(e) => {
+                        log::error!("[{conn_id}] failed to parse initial request headers! {e}");
+                        let _ = client_write.write_all(ERR_NOT_PROXIFIALBE).await;
+                        return;
+                    }
+                }
+            };
+
+            // Connect to upstream
+            let mut upstream = match TcpStream::connect(headers_processed.target_host).await {
+                Ok(upstream) => upstream,
+                Err(e) => {
+                    log::error!("[{conn_id}] Could not connect to upstream! {e}");
+                    let _ = client_write.write_all(ERR_NOT_PROXIFIALBE).await;
+                    return;
+                }
+            };
+
+            // Transfer modified headers to upstream
+            if let Err(e) = upstream.write_all(&headers_processed.buff).await {
+                log::error!("[{conn_id}] Could not forward initial bytes to upstream! {e}");
+                let _ = client_write.write_all(ERR_NOT_PROXIFIALBE).await;
+                return;
+            }
+
+            // Enter in loop to forward remaining data
             loop {
                 tokio::select! {
                     count = client_read.read(&mut buf_client) => {
                         let  count = match count{  Ok(count) => count, Err(e) => {
                             log::error!("[{conn_id}]  Failed to read data from client, closing connection! {e}");
-                            return;
+                            break;
                         }};
-                        log::info!("[{conn_id}]  Got a new client read {count} - {base_file_name}");
+                        log::debug!("[{conn_id}]  Got a new client read {count}");
 
                         if count == 0 {
                             log::warn!("[{conn_id}] infinite loop (client), closing connection");
                             drop(upstream);
-                            return;
+                            break;
                         }
 
-                        // We need to modify some headers (if not done already) to adapt the request to the server
+                        // In case of connection reuse, we need to reanalyze data
-                        let buff = if !modified_headers {
+                        if ARGS.path_prefix_header.is_some() &&
-
+                            let Ok(Some(res))= process_headers(&buf_client[..count])
-                            // Check for URL prefix
+                            && let Err(e) = upstream.write_all(&res.buff).await {
-                            if let Some(prefix) = &args.prefix
+                                log::error!("[{conn_id}] Failed to write to upstream! {e}");
-                                && !String::from_utf8_lossy(&buf_client[..count]).split_once('\n').map(|l|l.0).unwrap_or("").contains(&format!(" {prefix}")) {
+                                break;
-                                    client_write.write_all(ERR_NOT_PROXIFIABLE).await.expect("Failed to respond to client");
-                                    client_write.flush().await.expect("Failed to flush response to client!");
-                                    return;
                         }
 
-                            modified_headers = true;
+                        if let Err(e)=upstream.write_all(&buf_client[..count]).await {
-                            manipulate_headers(&buf_client[..count], &args.upstream_dns)
+                            log::error!("[{conn_id}] Failed to write to upstream! {e}");
+                            break;
                         }
-                        else {
-                            buf_client[..count].to_vec()
-                        };
-
-                        upstream.write_all(&buff).await.unwrap_or_else(|_| panic!("[{conn_id}] Failed to write to upstream"));
                     }
 
                     count = upstream.read(&mut buf_server) => {
@@ -118,47 +147,88 @@ async fn main() -> Result<(), Box<dyn Error>> {
                             Ok(count) => count,
                             Err(e) => {
                                 log::error!("[{conn_id}] Failed to read from upstream! {e}");
-                                return;
+                                break;
                             }
                         };
 
                         if count == 0 {
                             log::warn!("[{conn_id}] infinite loop (upstream), closing connection");
                             drop(upstream);
-                            return;
+                            break;
                         }
 
-                        log::info!("[{conn_id}] Got a new upstream read {count} - {base_file_name}");
+                        log::debug!("[{conn_id}] Got a new upstream read {count}");
-                        client_write.write_all(&buf_server[..count]).await.expect("Failed to write to client");
+                        if let Err(e) = client_write.write_all(&buf_server[..count]).await {
+                            log::error!("Failed to write to upstream! {e}");
+                            break;
+                        };
                     }
                 }
             }
+
+            log::info!("[{conn_id}] Connection finished.");
         });
     }
 }
 
-fn manipulate_headers(buff: &[u8], host: &str) -> Vec<u8> {
+struct ProcessHeadersResult {
-    let mut out = Vec::with_capacity(buff.len());
+    buff: Vec<u8>,
-
+    target_host: String,
-    let mut i = 0;
-    while i < buff.len() {
-        if buff[i] != b'\n' || i + 1 == buff.len() || !buff[i + 1..].starts_with(b"Host:") {
-            out.push(buff[i]);
-            i += 1;
-            continue;
 }
 
-        i += 1;
+fn process_headers(buff: &[u8]) -> anyhow::Result<Option<ProcessHeadersResult>> {
-        out.push(b'\n');
+    let mut headers = [httparse::EMPTY_HEADER; 64];
+    let mut req = httparse::Request::new(&mut headers);
+    let parsing_res = req.parse(buff)?;
 
-        out.append(&mut format!("Host: {host}").as_bytes().to_vec());
+    let target_host = headers
+        .iter()
+        .find(|h| h.name.eq_ignore_ascii_case(&ARGS.target_host_port_header))
+        .map(|h| String::from_utf8_lossy(h.value));
 
-        while buff[i] != b'\r' && buff[i] != b'\n' {
+    log::debug!("Request headers: {:?}", headers);
-            i += 1;
+
+    let Some(target_host) = target_host else {
+        if parsing_res.is_partial() {
+            return Ok(None);
+        } else {
+            anyhow::bail!(
+                "Request is complete without header {}",
+                ARGS.target_host_port_header
+            )
+        }
+    };
+
+    // Check if path needs to be prefixed
+    let prefix_path = if let Some(hname) = &ARGS.path_prefix_header {
+        headers
+            .iter()
+            .find(|h| h.name.eq_ignore_ascii_case(hname))
+            .map(|h| String::from_utf8_lossy(h.value).replace(['\n', '\r', '\t', ' '], ""))
+    } else {
+        None
+    };
+
+    // Perform prefix injection
+    let mut buff = buff.to_vec();
+    if let Some(prefix) = prefix_path {
+        let pos = buff.iter().position(|c| c == &b' ');
+        log::debug!("Add path prefix to request {prefix}");
+        if let Some(pos) = pos {
+            for (num, c) in prefix.as_bytes().iter().enumerate() {
+                buff.insert(pos + 1 + num, *c);
+            }
+        } else {
+            log::warn!("Unable to inject prefix!");
         }
     }
 
-    out
+    log::trace!("Final request: {}", String::from_utf8_lossy(&buff));
+
+    Ok(Some(ProcessHeadersResult {
+        target_host: target_host.to_string(),
+        buff,
+    }))
 }
 
 #[cfg(test)]