Merge pull request #3 from freedelity/version

check that protocol version match between client and server

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 - New flag `--hash` which allow to specify the hash algorithm used for computing blocks checksums.
 
+- Server and client check that they are using the same version of the procotol before going on.
+
 # 1.0.0 (2024-02-01)
 
 Initial release

src/client.rs

@@ -1,7 +1,9 @@
 use crate::hash_file::hash_file;
 use crate::sync::Loan;
 use crate::HashAlgorithm;
-use crate::{check_status, write_string, ResumableReadString, ResumableWriteFileBlock};
+use crate::{
+    check_status, write_string, ResumableReadString, ResumableWriteFileBlock, PROTOCOL_VERSION,
+};
 use anyhow::anyhow;
 use futures::future::OptionFuture;
 use std::collections::VecDeque;
@@ -31,6 +33,10 @@ pub async fn new_process(options: ClientProcessOptions) -> Result<(), anyhow::Er
     stream.write_all(options.secret.as_bytes()).await?;
     check_status(&mut stream).await?;
 
+    // send protocol version
+    stream.write_u8(PROTOCOL_VERSION).await?;
+    check_status(&mut stream).await?;
+
     // send dest path
     write_string(
         &mut stream,

src/common.rs

@@ -3,6 +3,8 @@ use anyhow::{anyhow, bail};
 use int_enum::IntEnum;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
+pub const PROTOCOL_VERSION: u8 = 1;
+
 #[repr(u8)]
 #[derive(Debug, IntEnum)]
 pub enum StatusCode {
@@ -12,6 +14,7 @@ pub enum StatusCode {
     PermissionDenied = 3,
     ClientAlreadyConnected = 4,
     UnknownHashAlgorithm = 5,
+    UnsupportedProtocolVersion = 6,
 }
 
 pub async fn write_string<T: AsyncWriteExt + std::marker::Unpin, S: Into<String>>(
@@ -56,6 +59,7 @@ pub async fn check_status<T: AsyncReadExt + std::marker::Unpin>(
         StatusCode::UnknownHashAlgorithm => {
             Err(anyhow!("Hash algorithm is not supported on remote end"))
         }
+        StatusCode::UnsupportedProtocolVersion => Err(anyhow!("Protocol version mismatch")),
     }
 }
 

src/main.rs

@@ -19,7 +19,7 @@ mod utils;
 use common::{
     check_status, read_string, write_status, write_string, ResumableAsyncWriteAll,
     ResumableReadFileBlock, ResumableReadString, ResumableWriteFileBlock, ResumableWriteString,
-    StatusCode,
+    StatusCode, PROTOCOL_VERSION,
 };
 
 use remote_start::{remote_start_server, RemoteStartOptions};

src/server.rs

@@ -2,7 +2,7 @@ use crate::hash_file::hash_file;
 use crate::HashAlgorithm;
 use crate::{
     read_string, write_status, ResumableAsyncWriteAll, ResumableReadFileBlock,
-    ResumableWriteString, StatusCode,
+    ResumableWriteString, StatusCode, PROTOCOL_VERSION,
 };
 use futures::future::OptionFuture;
 use std::fs::File;
@@ -25,7 +25,13 @@ pub async fn process_new_client(
     if client_secret != secret.as_bytes() {
         return Ok(StatusCode::InvalidSecret);
     }
+    write_status(client, StatusCode::Ack).await?;
 
+    // check client protocol version
+    let client_protocol_version = client.read_u8().await?;
+    if client_protocol_version != PROTOCOL_VERSION {
+        return Ok(StatusCode::UnsupportedProtocolVersion);
+    }
     write_status(client, StatusCode::Ack).await?;
 
     // get dest path