hooks: reserver only high-ports to limit possibility of hitting port from rhodecode stack

rhodecode/lib/hooks_daemon.py

@@ -1,350 +1,357 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2010-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 import os
 import time
 import logging
 import tempfile
 import traceback
 import threading
 import socket
+import random
 
 from BaseHTTPServer import BaseHTTPRequestHandler
 from SocketServer import TCPServer
 
 import rhodecode
 from rhodecode.lib.exceptions import HTTPLockedRC, HTTPBranchProtected
 from rhodecode.model import meta
 from rhodecode.lib.base import bootstrap_request, bootstrap_config
 from rhodecode.lib import hooks_base
 from rhodecode.lib.utils2 import AttributeDict
 from rhodecode.lib.ext_json import json
 from rhodecode.lib import rc_cache
 
 log = logging.getLogger(__name__)
 
 
 class HooksHttpHandler(BaseHTTPRequestHandler):
 
     def do_POST(self):
         method, extras = self._read_request()
         txn_id = getattr(self.server, 'txn_id', None)
         if txn_id:
             log.debug('Computing TXN_ID based on `%s`:`%s`',
                       extras['repository'], extras['txn_id'])
             computed_txn_id = rc_cache.utils.compute_key_from_params(
                 extras['repository'], extras['txn_id'])
             if txn_id != computed_txn_id:
                 raise Exception(
                     'TXN ID fail: expected {} got {} instead'.format(
                         txn_id, computed_txn_id))
 
         try:
             result = self._call_hook(method, extras)
         except Exception as e:
             exc_tb = traceback.format_exc()
             result = {
                 'exception': e.__class__.__name__,
                 'exception_traceback': exc_tb,
                 'exception_args': e.args
             }
         self._write_response(result)
 
     def _read_request(self):
         length = int(self.headers['Content-Length'])
         body = self.rfile.read(length).decode('utf-8')
         data = json.loads(body)
         return data['method'], data['extras']
 
     def _write_response(self, result):
         self.send_response(200)
         self.send_header("Content-type", "text/json")
         self.end_headers()
         self.wfile.write(json.dumps(result))
 
     def _call_hook(self, method, extras):
         hooks = Hooks()
         try:
             result = getattr(hooks, method)(extras)
         finally:
             meta.Session.remove()
         return result
 
     def log_message(self, format, *args):
         """
         This is an overridden method of BaseHTTPRequestHandler which logs using
         logging library instead of writing directly to stderr.
         """
 
         message = format % args
 
         log.debug(
             "%s - - [%s] %s", self.client_address[0],
             self.log_date_time_string(), message)
 
 
 class DummyHooksCallbackDaemon(object):
     hooks_uri = ''
 
     def __init__(self):
         self.hooks_module = Hooks.__module__
 
     def __enter__(self):
         log.debug('Running `%s` callback daemon', self.__class__.__name__)
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         log.debug('Exiting `%s` callback daemon', self.__class__.__name__)
 
 
 class ThreadedHookCallbackDaemon(object):
 
     _callback_thread = None
     _daemon = None
     _done = False
 
     def __init__(self, txn_id=None, host=None, port=None):
         self._prepare(txn_id=txn_id, host=host, port=port)
 
     def __enter__(self):
         log.debug('Running `%s` callback daemon', self.__class__.__name__)
         self._run()
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         log.debug('Exiting `%s` callback daemon', self.__class__.__name__)
         self._stop()
 
     def _prepare(self, txn_id=None, host=None, port=None):
         raise NotImplementedError()
 
     def _run(self):
         raise NotImplementedError()
 
     def _stop(self):
         raise NotImplementedError()
 
 
 class HttpHooksCallbackDaemon(ThreadedHookCallbackDaemon):
     """
     Context manager which will run a callback daemon in a background thread.
     """
 
     hooks_uri = None
 
     # From Python docs: Polling reduces our responsiveness to a shutdown
     # request and wastes cpu at all other times.
     POLL_INTERVAL = 0.01
 
     def get_hostname(self):
         return socket.gethostname() or '127.0.0.1'
 
-    def get_available_port(self):
-        mysocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        mysocket.bind((self.get_hostname(), 0))
-        port = mysocket.getsockname()[1]
-        mysocket.close()
-        del mysocket
-        return port
+    def get_available_port(self, min_port=20000, max_port=65535):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        hostname = self.get_hostname()
+
+        for _ in range(min_port, max_port):
+            pick_port = random.randint(min_port, max_port)
+            try:
+                sock.bind((hostname, pick_port))
+                sock.close()
+                del sock
+                return pick_port
+            except OSError:
+                pass
 
     def _prepare(self, txn_id=None, host=None, port=None):
         if not host or host == "*":
             host = self.get_hostname()
         if not port:
             port = self.get_available_port()
 
         server_address = (host, port)
         self.hooks_uri = '{}:{}'.format(host, port)
         self.txn_id = txn_id
         self._done = False
 
         log.debug(
             "Preparing HTTP callback daemon at `%s` and registering hook object: %s",
             self.hooks_uri, HooksHttpHandler)
 
         self._daemon = TCPServer(server_address, HooksHttpHandler)
         # inject transaction_id for later verification
         self._daemon.txn_id = self.txn_id
 
     def _run(self):
         log.debug("Running event loop of callback daemon in background thread")
         callback_thread = threading.Thread(
             target=self._daemon.serve_forever,
             kwargs={'poll_interval': self.POLL_INTERVAL})
         callback_thread.daemon = True
         callback_thread.start()
         self._callback_thread = callback_thread
 
     def _stop(self):
         log.debug("Waiting for background thread to finish.")
         self._daemon.shutdown()
         self._callback_thread.join()
         self._daemon = None
         self._callback_thread = None
         if self.txn_id:
             txn_id_file = get_txn_id_data_path(self.txn_id)
             log.debug('Cleaning up TXN ID %s', txn_id_file)
             if os.path.isfile(txn_id_file):
                 os.remove(txn_id_file)
 
         log.debug("Background thread done.")
 
 
 def get_txn_id_data_path(txn_id):
     import rhodecode
 
     root = rhodecode.CONFIG.get('cache_dir') or tempfile.gettempdir()
     final_dir = os.path.join(root, 'svn_txn_id')
 
     if not os.path.isdir(final_dir):
         os.makedirs(final_dir)
     return os.path.join(final_dir, 'rc_txn_id_{}'.format(txn_id))
 
 
 def store_txn_id_data(txn_id, data_dict):
     if not txn_id:
         log.warning('Cannot store txn_id because it is empty')
         return
 
     path = get_txn_id_data_path(txn_id)
     try:
         with open(path, 'wb') as f:
             f.write(json.dumps(data_dict))
     except Exception:
         log.exception('Failed to write txn_id metadata')
 
 
 def get_txn_id_from_store(txn_id):
     """
     Reads txn_id from store and if present returns the data for callback manager
     """
     path = get_txn_id_data_path(txn_id)
     try:
         with open(path, 'rb') as f:
             return json.loads(f.read())
     except Exception:
         return {}
 
 
 def prepare_callback_daemon(extras, protocol, host, use_direct_calls, txn_id=None):
     txn_details = get_txn_id_from_store(txn_id)
     port = txn_details.get('port', 0)
     if use_direct_calls:
         callback_daemon = DummyHooksCallbackDaemon()
         extras['hooks_module'] = callback_daemon.hooks_module
     else:
         if protocol == 'http':
             callback_daemon = HttpHooksCallbackDaemon(
                 txn_id=txn_id, host=host, port=port)
         else:
             log.error('Unsupported callback daemon protocol "%s"', protocol)
             raise Exception('Unsupported callback daemon protocol.')
 
     extras['hooks_uri'] = callback_daemon.hooks_uri
     extras['hooks_protocol'] = protocol
     extras['time'] = time.time()
 
     # register txn_id
     extras['txn_id'] = txn_id
     log.debug('Prepared a callback daemon: %s at url `%s`',
               callback_daemon.__class__.__name__, callback_daemon.hooks_uri)
     return callback_daemon, extras
 
 
 class Hooks(object):
     """
     Exposes the hooks for remote call backs
     """
 
     def repo_size(self, extras):
         log.debug("Called repo_size of %s object", self)
         return self._call_hook(hooks_base.repo_size, extras)
 
     def pre_pull(self, extras):
         log.debug("Called pre_pull of %s object", self)
         return self._call_hook(hooks_base.pre_pull, extras)
 
     def post_pull(self, extras):
         log.debug("Called post_pull of %s object", self)
         return self._call_hook(hooks_base.post_pull, extras)
 
     def pre_push(self, extras):
         log.debug("Called pre_push of %s object", self)
         return self._call_hook(hooks_base.pre_push, extras)
 
     def post_push(self, extras):
         log.debug("Called post_push of %s object", self)
         return self._call_hook(hooks_base.post_push, extras)
 
     def _call_hook(self, hook, extras):
         extras = AttributeDict(extras)
         server_url = extras['server_url']
         request = bootstrap_request(application_url=server_url)
 
         bootstrap_config(request)  # inject routes and other interfaces
 
         # inject the user for usage in hooks
         request.user = AttributeDict({'username': extras.username,
                                       'ip_addr': extras.ip,
                                       'user_id': extras.user_id})
 
         extras.request = request
 
         try:
             result = hook(extras)
             if result is None:
                 raise Exception(
                     'Failed to obtain hook result from func: {}'.format(hook))
         except HTTPBranchProtected as handled_error:
             # Those special cases doesn't need error reporting. It's a case of
             # locked repo or protected branch
             result = AttributeDict({
                 'status': handled_error.code,
                 'output': handled_error.explanation
             })
         except (HTTPLockedRC, Exception) as error:
             # locked needs different handling since we need to also
             # handle PULL operations
             exc_tb = ''
             if not isinstance(error, HTTPLockedRC):
                 exc_tb = traceback.format_exc()
                 log.exception('Exception when handling hook %s', hook)
             error_args = error.args
             return {
                 'status': 128,
                 'output': '',
                 'exception': type(error).__name__,
                 'exception_traceback': exc_tb,
                 'exception_args': error_args,
             }
         finally:
             meta.Session.remove()
 
         log.debug('Got hook call response %s', result)
         return {
             'status': result.status,
             'output': result.output,
         }
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         pass