mcp-infra

Instructions

Implementation Reference

• server.py:9-46 (handler)

  Implementation of the get_processes_by_ports MCP tool handler.

  @mcp.tool()
  def get_processes_by_ports(ports: list[int]) -> str:
      """Return all running processes listening on the given ports.
  
      Args:
          ports: List of port numbers to check.
      """
      results = {}
  
      for port in ports:
          try:
              output = subprocess.check_output(
                  ["ss", "-tlnp", f"sport = :{port}"],
                  stderr=subprocess.STDOUT,
                  text=True,
              )
              lines = [l for l in output.strip().splitlines() if str(port) in l]
              processes = []
              for line in lines:
                  # Extract PID/process name from ss output: users:(("name",pid=N,fd=N))
                  if "users:((" in line:
                      users_part = line.split("users:((")[1].rstrip(")")
                      for entry in users_part.split("),("):
                          entry = entry.strip('(")')
                          parts = entry.split(",")
                          name = parts[0].strip('"')
                          pid = next(
                              (p.split("=")[1] for p in parts if p.strip().startswith("pid=")),
                              None,
                          )
                          processes.append({"name": name, "pid": pid})
                  else:
                      processes.append({"raw": line})
              results[port] = processes if processes else []
          except subprocess.CalledProcessError as e:
              results[port] = {"error": e.output.strip()}
  
      return json.dumps(results, indent=2)