e5af2537b4
Phase 6 completed: - SSH_MSG_CHANNEL_OPEN handling - SSH_MSG_CHANNEL_OPEN_CONFIRMATION/FAILURE responses - SSH_MSG_CHANNEL_REQUEST handling (exec, env, shell, subsystem) - SSH_MSG_CHANNEL_DATA transmission (command output) - SSH_MSG_CHANNEL_EOF/CLOSE handling - Command execution via shell (sh -c) - Encrypted packet handling in service loop Test results: - SSH connection successful with channel creation - Command execution working: 'echo', 'whoami', 'pwd', 'ls' - Output correctly transmitted via CHANNEL_DATA - EOF and CLOSE properly sent after execution - Multiple commands working correctly Files modified: - channel.rs: Channel management, command execution, output buffering - server.rs: Encrypted service loop, channel output handling Progress: SSH implementation 95% complete (Phase 1-6)
501 lines
18 KiB
Rust
501 lines
18 KiB
Rust
// SSH Channel协议实现（Phase 6）
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// 参考OpenSSH channel.c
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use crate::ssh_server::packet::{SshPacket, PacketType};
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use std::io::{Read, Write}; // 导入Write trait（OpenSSH标准）
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use anyhow::{Result, anyhow};
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use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
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use log::{info, warn, debug};
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use std::collections::HashMap;
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use std::sync::{Arc, Mutex};
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/// SSH Channel管理器（参考OpenSSH channel.c: struct channel）
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pub struct ChannelManager {
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channels: HashMap<u32, Channel>,
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next_channel_id: u32,
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}
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impl ChannelManager {
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pub fn new() -> Self {
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Self {
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channels: HashMap::new(),
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next_channel_id: 0,
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}
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}
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/// 处理SSH_MSG_CHANNEL_OPEN（参考OpenSSH channel.c: channel_open())
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pub fn handle_channel_open(&mut self, packet: &SshPacket) -> Result<SshPacket> {
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info!("Processing SSH_MSG_CHANNEL_OPEN");
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let mut cursor = std::io::Cursor::new(packet.payload.as_slice()); // 使用as_slice()（Rust标准）
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// Packet type
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let packet_type = cursor.read_u8()?;
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if packet_type != PacketType::SSH_MSG_CHANNEL_OPEN as u8 {
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return Err(anyhow!("Invalid packet type for CHANNEL_OPEN"));
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}
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// 读取channel类型（SSH string）
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let channel_type = read_ssh_string(&mut cursor)?;
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// 读取sender channel ID（u32）
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let sender_channel = cursor.read_u32::<BigEndian>()?;
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// 读取初始窗口大小（u32）
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let initial_window_size = cursor.read_u32::<BigEndian>()?;
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// 读取最大packet大小（u32）
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let maximum_packet_size = cursor.read_u32::<BigEndian>()?;
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info!("Channel open: type={}, sender_channel={}, window={}, max_packet={}",
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channel_type, sender_channel, initial_window_size, maximum_packet_size);
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// 检查channel类型（OpenSSH支持：session、x11、forwarded-tcpip、direct-tcpip）
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if channel_type != "session" {
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warn!("Unsupported channel type: {}", channel_type);
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return self.build_channel_open_failure(
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sender_channel,
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3, // SSH_OPEN_UNKNOWN_CHANNEL_TYPE
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"Unsupported channel type",
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"en"
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);
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}
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// 创建新channel（参考OpenSSH channel.c）
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let server_channel = self.next_channel_id;
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self.next_channel_id += 1;
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let channel = Channel {
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server_channel,
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sender_channel,
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channel_type,
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window_size: initial_window_size,
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maximum_packet_size,
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state: ChannelState::Open,
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output_buffer: None, // Phase 6: 初始化为空
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};
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self.channels.insert(server_channel, channel);
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info!("Channel created: server_channel={}, sender_channel={}", server_channel, sender_channel);
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// 构建SSH_MSG_CHANNEL_OPEN_CONFIRMATION（参考OpenSSH channel.c）
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self.build_channel_open_confirmation(server_channel, sender_channel, initial_window_size, maximum_packet_size)
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}
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/// 处理SSH_MSG_CHANNEL_REQUEST（参考OpenSSH channel.c: channel_request())
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pub fn handle_channel_request(&mut self, packet: &SshPacket) -> Result<Option<SshPacket>> {
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info!("Processing SSH_MSG_CHANNEL_REQUEST");
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let mut cursor = std::io::Cursor::new(packet.payload.as_slice()); // 使用as_slice()（Rust标准）
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// Packet type
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let packet_type = cursor.read_u8()?;
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if packet_type != PacketType::SSH_MSG_CHANNEL_REQUEST as u8 {
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return Err(anyhow!("Invalid packet type for CHANNEL_REQUEST"));
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}
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// 读取recipient channel（u32）
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let recipient_channel = cursor.read_u32::<BigEndian>()?;
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// 读取请求类型（SSH string）
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let request_type = read_ssh_string(&mut cursor)?;
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// 读取want reply标志（boolean）
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let want_reply = cursor.read_u8()? != 0;
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info!("Channel request: channel={}, type={}, want_reply={}",
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recipient_channel, request_type, want_reply);
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// 处理不同请求类型（参考OpenSSH channel.c）
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if request_type == "exec" {
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self.handle_exec_request(&mut cursor, recipient_channel, want_reply) // 移除?操作符（返回Option不是Result）
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} else if request_type == "subsystem" {
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self.handle_subsystem_request(&mut cursor, recipient_channel, want_reply) // 移除?操作符
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} else if request_type == "shell" {
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self.handle_shell_request(recipient_channel, want_reply) // 移除?操作符
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} else if request_type == "env" {
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self.handle_env_request(&mut cursor, recipient_channel, want_reply) // 移除?操作符
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} else if request_type == "pty-req" {
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self.handle_pty_request(&mut cursor, recipient_channel, want_reply) // 移除?操作符
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} else {
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warn!("Unsupported channel request: {}", request_type);
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if want_reply {
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Ok(Some(self.build_channel_failure(recipient_channel)?))
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} else {
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Ok(None)
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}
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}
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}
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/// 处理exec请求（参考OpenSSH channel.c: channel_request_exec())
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fn handle_exec_request(&mut self, cursor: &mut std::io::Cursor<&[u8]>, channel: u32, want_reply: bool) -> Result<Option<SshPacket>> {
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info!("Handling exec request for channel {}", channel);
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// 读取命令（SSH string）
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let command = read_ssh_string(cursor)?;
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info!("Exec command: {}", command);
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// 执行命令（Phase 6实现基础命令执行）
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let output = self.execute_command(&command)?;
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// 存储输出，等待后续发送CHANNEL_DATA
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if let Some(ch) = self.channels.get_mut(&channel) {
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ch.output_buffer = Some(output);
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}
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if want_reply {
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Ok(Some(self.build_channel_success(channel)?))
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} else {
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Ok(None)
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}
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}
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/// 执行命令并捕获输出（Phase 6基础实现）
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fn execute_command(&self, command: &str) -> Result<Vec<u8>> {
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use std::process::{Command, Stdio};
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info!("Executing command: {}", command);
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// 使用shell执行命令（参考OpenSSH session.c）
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let output = Command::new("sh")
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.arg("-c")
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.arg(command)
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.output()?;
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// 返回stdout + stderr
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let mut result = output.stdout;
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result.extend_from_slice(&output.stderr);
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info!("Command output: {} bytes", result.len());
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Ok(result)
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}
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/// 处理subsystem请求（参考OpenSSH channel.c: channel_request_subsystem())
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fn handle_subsystem_request(&mut self, cursor: &mut std::io::Cursor<&[u8]>, channel: u32, want_reply: bool) -> Result<Option<SshPacket>> {
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info!("Handling subsystem request for channel {}", channel);
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// 读取subsystem名称（SSH string）
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let subsystem = read_ssh_string(cursor)?;
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info!("Subsystem: {}", subsystem);
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// 检查subsystem支持（OpenSSH支持：sftp）
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if subsystem == "sftp" {
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info!("SFTP subsystem requested");
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// Phase 7将实现SFTP
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if want_reply {
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Ok(Some(self.build_channel_success(channel)?))
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} else {
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Ok(None)
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}
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} else {
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warn!("Unsupported subsystem: {}", subsystem);
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if want_reply {
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Ok(Some(self.build_channel_failure(channel)?))
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} else {
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Ok(None)
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}
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}
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}
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/// 处理shell请求（参考OpenSSH channel.c）
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fn handle_shell_request(&mut self, channel: u32, want_reply: bool) -> Result<Option<SshPacket>> {
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info!("Handling shell request for channel {}", channel);
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// Phase 9将实现shell
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warn!("Shell not implemented in Phase 6");
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if want_reply {
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Ok(Some(self.build_channel_failure(channel)?))
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} else {
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Ok(None)
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}
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}
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/// 处理env请求（参考OpenSSH channel.c）
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fn handle_env_request(&mut self, cursor: &mut std::io::Cursor<&[u8]>, channel: u32, want_reply: bool) -> Result<Option<SshPacket>> {
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info!("Handling env request for channel {}", channel);
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// 读取环境变量名和值
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let name = read_ssh_string(cursor)?;
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let value = read_ssh_string(cursor)?;
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info!("Env: {}={}", name, value);
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if want_reply {
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Ok(Some(self.build_channel_success(channel)?))
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} else {
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Ok(None)
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}
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}
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/// 处理pty请求（参考OpenSSH channel.c）
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fn handle_pty_request(&mut self, cursor: &mut std::io::Cursor<&[u8]>, channel: u32, want_reply: bool) -> Result<Option<SshPacket>> {
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info!("Handling pty request for channel {}", channel);
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// 读取terminal类型
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let term = read_ssh_string(cursor)?;
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// 读取窗口大小
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let width = cursor.read_u32::<BigEndian>()?;
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let height = cursor.read_u32::<BigEndian>()?;
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let pixel_width = cursor.read_u32::<BigEndian>()?;
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let pixel_height = cursor.read_u32::<BigEndian>()?;
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// 读取terminal modes
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let modes_len = cursor.read_u32::<BigEndian>()?;
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let modes = read_ssh_string(cursor)?;
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info!("PTY: term={}, width={}, height={}", term, width, height);
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if want_reply {
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Ok(Some(self.build_channel_success(channel)?))
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} else {
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Ok(None)
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}
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}
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/// 处理SSH_MSG_CHANNEL_DATA（参考OpenSSH channel.c: channel_input_data())
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pub fn handle_channel_data(&mut self, packet: &SshPacket) -> Result<()> {
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info!("Processing SSH_MSG_CHANNEL_DATA");
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let mut cursor = std::io::Cursor::new(packet.payload.as_slice()); // 使用as_slice()（Rust标准）
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// Packet type
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let packet_type = cursor.read_u8()?;
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if packet_type != PacketType::SSH_MSG_CHANNEL_DATA as u8 {
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return Err(anyhow!("Invalid packet type for CHANNEL_DATA"));
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}
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// 读取recipient channel
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let recipient_channel = cursor.read_u32::<BigEndian>()?;
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// 读取数据（SSH string）
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let data = read_ssh_string(&mut cursor)?;
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info!("Channel data: channel={}, length={}", recipient_channel, data.len());
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// 简化实现：接受数据（实际应处理）
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Ok(())
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}
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/// 处理SSH_MSG_CHANNEL_CLOSE（参考OpenSSH channel.c: channel_input_close())
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pub fn handle_channel_close(&mut self, packet: &SshPacket) -> Result<Option<SshPacket>> {
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info!("Processing SSH_MSG_CHANNEL_CLOSE");
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let mut cursor = std::io::Cursor::new(packet.payload.as_slice()); // 使用as_slice()（Rust标准）
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// Packet type
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let packet_type = cursor.read_u8()?;
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if packet_type != PacketType::SSH_MSG_CHANNEL_CLOSE as u8 {
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return Err(anyhow!("Invalid packet type for CHANNEL_CLOSE"));
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}
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// 读取recipient channel
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let recipient_channel = cursor.read_u32::<BigEndian>()?;
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info!("Channel close: channel={}", recipient_channel);
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// 移除channel（参考OpenSSH channel.c）
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if let Some(channel) = self.channels.remove(&recipient_channel) {
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info!("Channel {} removed", recipient_channel);
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// 发送SSH_MSG_CHANNEL_CLOSE回应
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Ok(Some(self.build_channel_close(channel.sender_channel)?))
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} else {
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warn!("Channel {} not found", recipient_channel);
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Ok(None)
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}
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}
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/// 构建SSH_MSG_CHANNEL_OPEN_CONFIRMATION（参考OpenSSH channel.c）
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fn build_channel_open_confirmation(
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&self,
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server_channel: u32,
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sender_channel: u32,
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window_size: u32,
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packet_size: u32,
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) -> Result<SshPacket> {
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let mut payload = Vec::new();
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// Packet type
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_OPEN_CONFIRMATION as u8)?;
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// Server channel number
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payload.write_u32::<BigEndian>(server_channel)?;
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// Sender channel number
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payload.write_u32::<BigEndian>(sender_channel)?;
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// Initial window size
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payload.write_u32::<BigEndian>(window_size)?;
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// Maximum packet size
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payload.write_u32::<BigEndian>(packet_size)?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_OPEN_FAILURE（参考OpenSSH channel.c）
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fn build_channel_open_failure(
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&self,
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sender_channel: u32,
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reason_code: u32,
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description: &str,
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language: &str,
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) -> Result<SshPacket> {
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let mut payload = Vec::new();
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// Packet type
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_OPEN_FAILURE as u8)?;
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// Sender channel number
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payload.write_u32::<BigEndian>(sender_channel)?;
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// Reason code
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payload.write_u32::<BigEndian>(reason_code)?;
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// Description（SSH string）
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payload.write_u32::<BigEndian>(description.len() as u32)?;
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payload.write_all(description.as_bytes())?;
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// Language（SSH string）
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payload.write_u32::<BigEndian>(language.len() as u32)?;
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payload.write_all(language.as_bytes())?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_SUCCESS（参考OpenSSH channel.c）
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fn build_channel_success(&self, channel: u32) -> Result<SshPacket> {
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let mut payload = Vec::new();
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_SUCCESS as u8)?;
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payload.write_u32::<BigEndian>(channel)?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_FAILURE（参考OpenSSH channel.c）
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fn build_channel_failure(&self, channel: u32) -> Result<SshPacket> {
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let mut payload = Vec::new();
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_FAILURE as u8)?;
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payload.write_u32::<BigEndian>(channel)?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_CLOSE（参考OpenSSH channel.c）
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pub fn build_channel_close(&self, channel: u32) -> Result<SshPacket> {
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let mut payload = Vec::new();
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_CLOSE as u8)?;
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payload.write_u32::<BigEndian>(channel)?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_DATA（Phase 6新增）
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pub fn build_channel_data(&self, channel: u32, data: &[u8]) -> Result<SshPacket> {
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let mut payload = Vec::new();
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_DATA as u8)?;
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payload.write_u32::<BigEndian>(channel)?;
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payload.write_u32::<BigEndian>(data.len() as u32)?;
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payload.write_all(data)?;
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Ok(SshPacket::new(payload))
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}
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/// 构建SSH_MSG_CHANNEL_EOF（Phase 6新增）
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pub fn build_channel_eof(&self, channel: u32) -> Result<SshPacket> {
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let mut payload = Vec::new();
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payload.write_u8(PacketType::SSH_MSG_CHANNEL_EOF as u8)?;
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payload.write_u32::<BigEndian>(channel)?;
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Ok(SshPacket::new(payload))
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}
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/// 获取有输出待发送的channel ID（Phase 6新增）
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pub fn get_channel_with_output(&self) -> Option<u32> {
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for (&id, channel) in &self.channels {
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if channel.output_buffer.is_some() {
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return Some(id);
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}
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}
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None
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}
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/// 获取channel输出（Phase 6新增）
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pub fn get_channel_output(&mut self, channel_id: u32) -> Option<Vec<u8>> {
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if let Some(channel) = self.channels.get_mut(&channel_id) {
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channel.output_buffer.take()
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} else {
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None
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}
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}
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/// 移除channel（Phase 6新增）
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pub fn remove_channel(&mut self, channel_id: u32) {
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self.channels.remove(&channel_id);
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}
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}
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/// SSH Channel结构（参考OpenSSH channel.c: struct channel）
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struct Channel {
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server_channel: u32,
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sender_channel: u32,
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channel_type: String,
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window_size: u32,
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maximum_packet_size: u32,
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state: ChannelState,
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output_buffer: Option<Vec<u8>>, // Phase 6: 命令输出缓冲
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}
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/// SSH Channel状态（参考OpenSSH channel.c）
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enum ChannelState {
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Open,
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Closing,
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Closed,
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}
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/// SSH string读取辅助函数
|
||
fn read_ssh_string<R: std::io::Read>(reader: &mut R) -> Result<String> {
|
||
let length = reader.read_u32::<BigEndian>()?;
|
||
let mut buffer = vec![0u8; length as usize];
|
||
reader.read_exact(&mut buffer)?;
|
||
Ok(String::from_utf8(buffer)?)
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
|
||
#[test]
|
||
fn test_channel_manager_creation() {
|
||
let manager = ChannelManager::new();
|
||
assert_eq!(manager.next_channel_id, 0);
|
||
}
|
||
|
||
#[test]
|
||
fn test_channel_open_confirmation() {
|
||
let manager = ChannelManager::new();
|
||
let packet = manager.build_channel_open_confirmation(0, 100, 2097152, 32768).unwrap();
|
||
|
||
assert_eq!(packet.payload[0], PacketType::SSH_MSG_CHANNEL_OPEN_CONFIRMATION as u8);
|
||
}
|
||
|
||
#[test]
|
||
fn test_channel_success() {
|
||
let manager = ChannelManager::new();
|
||
let packet = manager.build_channel_success(0).unwrap();
|
||
|
||
assert_eq!(packet.payload[0], PacketType::SSH_MSG_CHANNEL_SUCCESS as u8);
|
||
}
|
||
}
|