Merge pull request #89 from HsuJv/v0_4_5

Version 0.4.5

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ssh-rs"
-version = "0.4.4"
+version = "0.4.5"
 edition = "2021"
 authors = [
     "Gao Xiang Kang <[email protected]>",

changelog

@@ -1,3 +1,7 @@
+v0.4.5 (2023-11-17)
+    1. Fix the high cpu usage caused by non_block tcp
+    2. Fix the failuer of version agreement if the server sends more than one lines
+
 v0.4.4 (2023-11-15)
     1. Remove some debug print
     2. Fix the panic when connect to non-ssh servers

src/config/version.rs

@@ -23,22 +23,58 @@ impl Default for SshVersion {
     }
 }
 
+/// <https://www.rfc-editor.org/rfc/rfc4253#section-4.2>
+
+// When the connection has been established, both sides MUST send an
+// identification string.  This identification string MUST be
+
+//    SSH-protoversion-softwareversion SP comments CR LF
+
+// Since the protocol being defined in this set of documents is version
+// 2.0, the 'protoversion' MUST be "2.0".  The 'comments' string is
+// OPTIONAL.  If the 'comments' string is included, a 'space' character
+// (denoted above as SP, ASCII 32) MUST separate the 'softwareversion'
+// and 'comments' strings.  The identification MUST be terminated by a
+// single Carriage Return (CR) and a single Line Feed (LF) character
+// (ASCII 13 and 10, respectively).
 fn read_version<S>(stream: &mut S, tm: Option<Duration>) -> SshResult<Vec<u8>>
 where
     S: Read,
 {
-    let mut buf = vec![0; 128];
-    let timeout = Timeout::new(tm);
+    let mut ch = vec![0; 1];
+    const LF: u8 = 0xa;
+    let crlf = vec![0xd, 0xa];
+    let mut outbuf = vec![];
+    let mut timeout = Timeout::new(tm);
     loop {
-        match stream.read(&mut buf) {
+        match stream.read(&mut ch) {
             Ok(i) => {
-                // MY TO DO: To Skip the other lines
-                buf.truncate(i);
-                return Ok(buf);
+                if 0 == i {
+                    // eof got, return
+                    return Ok(outbuf);
+                }
+
+                outbuf.extend_from_slice(&ch);
+
+                if LF == ch[0] && outbuf.len() > 1 && outbuf.ends_with(&crlf) {
+                    // The server MAY send other lines of data before sending the version
+                    // string.  Each line SHOULD be terminated by a Carriage Return and Line
+                    // Feed.  Such lines MUST NOT begin with "SSH-", and SHOULD be encoded
+                    // in ISO-10646 UTF-8 [RFC3629] (language is not specified).  Clients
+                    // MUST be able to process such lines.  Such lines MAY be silently
+                    // ignored, or MAY be displayed to the client user.
+                    if outbuf.len() < 4 || &outbuf[0..4] != SSH_MAGIC {
+                        // skip other lines
+                        // and start read for another line
+                        outbuf.clear();
+                        continue;
+                    }
+                    return Ok(outbuf);
+                }
             }
             Err(e) => {
                 if let std::io::ErrorKind::WouldBlock = e.kind() {
-                    timeout.test()?;
+                    timeout.till_next_tick()?;
                     continue;
                 } else {
                     return Err(e.into());

src/constant.rs

@@ -1,5 +1,5 @@
 /// The client version
-pub(crate) const CLIENT_VERSION: &str = "SSH-2.0-SSH_RS-0.4.4";
+pub(crate) const CLIENT_VERSION: &str = "SSH-2.0-SSH_RS-0.4.5";
 pub(crate) const SSH_MAGIC: &[u8] = b"SSH-";
 
 /// The constant strings that used for ssh communication

src/lib.rs

@@ -1,6 +1,6 @@
 //! Dependencies
 //! ```toml
-//! ssh-rs = "0.4.4"
+//! ssh-rs = "0.4.5"
 //! ```
 //!
 //!Rust implementation of ssh2.0 client.

src/model/packet.rs

@@ -70,7 +70,7 @@ where
             }
             Err(e) => {
                 if let std::io::ErrorKind::WouldBlock = e.kind() {
-                    timeout.test()?;
+                    timeout.till_next_tick()?;
                     continue;
                 } else {
                     return Err(e.into());
@@ -117,7 +117,7 @@ where
             }
             Err(e) => {
                 if let std::io::ErrorKind::WouldBlock = e.kind() {
-                    timeout.test()?;
+                    timeout.till_next_tick()?;
                     continue;
                 } else {
                     return Err(e.into());

src/model/timeout.rs

@@ -1,28 +1,47 @@
 use crate::{SshError, SshResult};
 use std::time::{Duration, Instant};
 
+#[cfg(not(target_arch = "wasm32"))]
+const NANOS_PER_SEC: u64 = 1_000_000_000;
+
 pub(crate) struct Timeout {
     instant: Instant,
     timeout: Option<Duration>,
+    wait_tick: u64,
 }
 
 impl Timeout {
     pub fn new(timeout: Option<Duration>) -> Self {
         Timeout {
             instant: Instant::now(),
             timeout,
+            wait_tick: 1,
+        }
+    }
+
+    fn wait(&mut self) -> u64 {
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            let sleep_time = Duration::from_nanos(self.wait_tick);
+            std::thread::sleep(sleep_time);
+            if self.wait_tick < NANOS_PER_SEC {
+                self.wait_tick <<= 1;
+            }
         }
+        self.wait_tick
     }
 
-    pub fn test(&self) -> SshResult<()> {
+    pub fn till_next_tick(&mut self) -> SshResult<()> {
         if let Some(t) = self.timeout {
             if self.instant.elapsed() > t {
                 tracing::error!("time out.");
                 Err(SshError::TimeoutError)
             } else {
+                self.wait();
                 Ok(())
             }
         } else {
+            self.wait();
             Ok(())
         }
     }

version

@@ -1 +1 @@
-0.4.4
+0.4.5