362 lines
15 KiB
Python
362 lines
15 KiB
Python
import os
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import select
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import time
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import uuid
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import subprocess
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import threading
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from flask import Blueprint, request, current_app, session
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from flask_socketio import Namespace, join_room, leave_room, emit, SocketIO, rooms, disconnect
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from threading import Thread
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import sys
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from ..extensions import socketio
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import pty
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import termios
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import struct
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import fcntl
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import psutil
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TERM_INIT_CONFIG = {
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# instead of local server runnning this web terminal service
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# "domain" is the target that you want to access through local server (with this web terminal)
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# and before doing so - make sure you have username and port (on the "domain") to implement remote access
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'domain': '127.0.0.1', # or ip address like 192.168.10.11
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'client_path': {
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'telnet': '/usr/bin/telnet', # confirmed location of your client binary (with cmd like 'which telnet')
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'ssh': '/usr/bin/ssh'
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}
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}
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terminal_bp = Blueprint('terminal', __name__, url_prefix='/vsc-like')
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def set_winsize(fd, row, col, xpix=0, ypix=0):
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try:
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winsize = struct.pack("HHHH", row, col, xpix, ypix)
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fcntl.ioctl(fd, termios.TIOCSWINSZ, winsize)
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except (OSError, IOError):
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# File descriptor closed or invalid, do nothing
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pass
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def read_and_forward_pty_output(fd=None, pid=None, room_id=None, namespace=None):
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"""
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read data on pty master from the pty slave, and emit to the web terminal visitor
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"""
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max_read_bytes = 1024 * 20
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# 初始超时时间设置为较短值，确保响应迅速
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timeout = 0.05
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# 最大超时时间，避免太频繁的检查
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max_timeout = 0.5
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# 成功读取数据后的重置超时时间
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reset_timeout = 0.05
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try:
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while True:
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# 等待一段时间，减少CPU占用
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socketio.sleep(timeout)
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# 使用指数退避算法调整超时时间，但不超过最大值
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timeout = min(timeout * 1.5, max_timeout)
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# 检查子进程状态
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try:
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child_process = psutil.Process(pid)
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except psutil.NoSuchProcess:
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# 进程已终止，清理僵尸进程
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try:
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os.waitpid(pid, os.WNOHANG)
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except Exception:
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pass
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return
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# 检查进程状态，如果不是运行或睡眠状态，则退出
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if child_process.status() not in ('running', 'sleeping'):
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try:
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# 等待进程终止
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child_process.wait(timeout=1)
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except Exception:
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try:
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os.waitpid(pid, os.WNOHANG)
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except Exception:
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pass
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return
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# 如果文件描述符有效，尝试读取数据
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if fd:
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try:
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# 使用非阻塞select检查是否有数据可读
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(data_ready, _, _) = select.select([fd], [], [], 0)
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if data_ready:
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# 有数据可读，重置超时时间
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timeout = reset_timeout
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try:
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# 读取数据
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output = os.read(fd, max_read_bytes).decode()
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except (OSError, IOError, EOFError):
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# 文件描述符已关闭或其他IO错误，优雅退出
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return
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except UnicodeDecodeError as err:
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# 处理编码错误
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output = f"""
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***AQUI WEB TERM ERR***
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Unicode decode error: {err}
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***********************
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"""
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# 发送数据到客户端
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try:
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namespace.emit("pty_output", {"output": output}, room=room_id)
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except Exception:
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# 如果发送失败，客户端可能已断开连接，退出
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return
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except (OSError, IOError):
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# 文件描述符无效，优雅退出
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return
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except Exception as e:
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# 捕获任何其他未预期的异常，防止服务器崩溃
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current_app.logger.error(f"Unexpected error in read_and_forward_pty_output: {e}")
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finally:
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# 清理文件描述符
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if fd:
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try:
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os.close(fd)
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except Exception:
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pass
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class VSCLikeNameSpace(Namespace):
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def on_connect(self):
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"""new client connected"""
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# 确保terminal_config存在于session中
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if 'terminal_config' not in session:
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session['terminal_config'] = TERM_INIT_CONFIG.copy()
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session.modified = True
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terminal_config = session['terminal_config']
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# 检查是否已经有运行中的子进程
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if terminal_config.get('child_pid'):
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try:
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# 验证进程是否真的存在
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child_process = psutil.Process(terminal_config['child_pid'])
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if child_process.status() in ('running', 'sleeping'):
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current_app.logger.debug("Already running child process: {}".format(terminal_config['child_pid']))
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return
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except psutil.NoSuchProcess:
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# 进程不存在，清理配置
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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# create child process attached to a pty we can read from and write to
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(child_pid, fd) = pty.fork()
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lesson_path = session.get('path')
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if child_pid == 0:
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# this is the child process fork.
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# anything printed here will show up in the pty, including the output
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# of this subprocess
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try:
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# 获取终端配置
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terminal_config = session.get('terminal_config', {})
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term_type = terminal_config.get('term_type')
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if not term_type:
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print("Terminal type not specified, exit")
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os._exit(1)
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path = TERM_INIT_CONFIG.get('client_path', {}).get(term_type, None)
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if not path or not os.path.exists(path):
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print("Can't locate {} binary at {}, exit".format(term_type, path))
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os._exit(1)
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# 获取连接参数
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username = terminal_config.get('username')
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domain = terminal_config.get('domain', TERM_INIT_CONFIG['domain'])
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port = terminal_config.get('port')
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if not username or not domain:
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print("Missing required connection parameters, exit")
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os._exit(1)
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if term_type == 'telnet':
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# 使用telnet连接
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if not port:
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print("Port not specified for telnet, exit")
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os._exit(1)
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os.execl(path, 'telnet', '-l', username, domain, str(port))
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elif term_type == 'ssh':
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# 使用ssh连接
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ssh_port = port if port else 22 # 默认端口22
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os.execl(path, 'ssh', '-p', str(ssh_port), '{}@{}'.format(username, domain))
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else:
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print("Wrong term type {}, exit".format(term_type))
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os._exit(1)
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except Exception as e:
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print("Error in child process: {}", str(e))
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os._exit(1)
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else:
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# 更新会话配置
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terminal_config['fd'] = fd
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terminal_config['child_pid'] = child_pid
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terminal_config['room_id'] = rooms()[0]
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session.modified = True
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# 设置初始窗口大小
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set_winsize(fd, 50, 50)
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# 记录日志
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current_app.logger.debug("child pid = {}".format(child_pid))
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current_app.logger.debug("rooms of this session = {}".format(rooms()))
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# 启动后台任务读取pty输出
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socketio.start_background_task(read_and_forward_pty_output, fd, child_pid, rooms()[0], self)
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current_app.logger.debug("background task running")
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def on_pty_input(self, data):
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"""write to the child pty, which now is the ssh process from this machine to the 'domain' configured
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"""
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# 输入验证
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if not isinstance(data, dict):
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current_app.logger.error("Invalid input format: expected dictionary")
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return
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input_data = data.get("input")
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if not isinstance(input_data, str):
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current_app.logger.error("Invalid input data: expected string")
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return
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# 限制输入长度，防止缓冲区溢出
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if len(input_data) > 1024:
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input_data = input_data[:1024]
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current_app.logger.warning("Input truncated due to length")
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try:
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terminal_config = session.get('terminal_config', {})
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child_pid = terminal_config.get('child_pid')
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if not child_pid:
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current_app.logger.error("No child process found")
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return
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child_process = psutil.Process(child_pid)
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if child_process.status() not in ('running', 'sleeping'):
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current_app.logger.debug("Child process not running, cleaning up")
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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return
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fd = terminal_config.get('fd')
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if fd:
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try:
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os.write(fd, input_data.encode())
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except (OSError, IOError) as e:
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# File descriptor closed or invalid, clean up
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current_app.logger.debug(f"Error writing to file descriptor: {e}")
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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except psutil.NoSuchProcess:
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# Process no longer exists, clean up
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terminal_config = session.get('terminal_config', {})
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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except Exception as e:
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current_app.logger.error(f"Error in pty_input handling: {e}")
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def on_resize(self, data):
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# 输入验证
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if not isinstance(data, dict):
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current_app.logger.error("Invalid resize data format: expected dictionary")
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return
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rows = data.get("rows")
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cols = data.get("cols")
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# 验证行和列的值是否为正整数
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if not (isinstance(rows, int) and isinstance(cols, int)):
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current_app.logger.error("Invalid resize dimensions: expected integers")
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return
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# 限制窗口大小范围，防止异常值
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if rows <= 0 or rows > 1000 or cols <= 0 or cols > 1000:
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current_app.logger.error(f"Invalid resize dimensions: {rows}x{cols} (out of range)")
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return
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try:
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terminal_config = session.get('terminal_config', {})
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child_pid = terminal_config.get('child_pid')
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if not child_pid:
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current_app.logger.error("No child process found for resize")
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return
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# 检查子进程是否存在且运行中
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child_process = psutil.Process(child_pid)
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if child_process.status() not in ('running', 'sleeping'):
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current_app.logger.debug("Child process not running, cleaning up resize")
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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return
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fd = terminal_config.get('fd')
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if fd:
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# 检查文件描述符是否有效
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try:
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os.fstat(fd)
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set_winsize(fd, rows, cols)
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except (OSError, IOError) as e:
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# 文件描述符无效，清理资源
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current_app.logger.debug(f"Error resizing terminal: {e}")
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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except psutil.NoSuchProcess:
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# 进程不存在，清理资源
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terminal_config = session.get('terminal_config', {})
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terminal_config.pop('child_pid', None)
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terminal_config.pop('fd', None)
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session.modified = True
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except Exception as e:
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current_app.logger.error(f"Error in resize handling: {e}")
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def on_disconnect(self):
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terminal_config = session.get('terminal_config', {})
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child_pid = terminal_config.get('child_pid')
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fd = terminal_config.get('fd')
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# 先关闭文件描述符，避免其他操作尝试使用无效的文件描述符
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if fd:
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try:
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os.close(fd)
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except Exception:
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pass
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if child_pid:
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try:
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child_process = psutil.Process(child_pid)
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if child_process.status() in ('running', 'sleeping'):
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# if visitor just close the browser tab then left alone the pty here
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# it should be terminated by the parent process after
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child_process.terminate()
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# Wait for the process to terminate and collect its exit status
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child_process.wait(timeout=2)
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current_app.logger.debug('user left the pty alone, terminated and waited')
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except psutil.NoSuchProcess as err:
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# Process already terminated, try to wait anyway to clean up any zombie
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try:
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os.waitpid(child_pid, os.WNOHANG)
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except Exception:
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pass
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except psutil.TimeoutExpired:
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# If process didn't terminate in time, kill it forcefully
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try:
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child_process.kill()
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child_process.wait(timeout=1)
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except Exception:
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pass
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except Exception as err:
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current_app.logger.error(f'Error terminating process: {err}')
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# Reset session config
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session['terminal_config'] = TERM_INIT_CONFIG
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current_app.logger.debug('Client disconnected') |