Mercurial > hg
view mercurial/hgweb/server.py @ 40626:87a872555e90
revlog: detect incomplete revlog reads
_readsegment() is supposed to return N bytes of revlog revision
data starting at a file offset. Surprisingly, its behavior before
this patch never verified that it actually read and returned N
bytes! Instead, it would perform the read(), then return whatever
data was available. And even more surprisingly, nothing in the
call chain appears to have been validating that it received all
the data it was expecting.
This behavior could lead to partial or incomplete revision chunks
being operated on. This could result in e.g. cached deltas being
applied against incomplete base revisions. The delta application
process would happily perform this operation. Only hash
verification would detect the corruption and save us.
This commit changes the behavior of raw revlog reading to validate
that we actually read() the number of bytes that were requested.
We will raise a more specific error faster, rather than possibly
have it go undetected or manifest later in the call stack, at
delta application or hash verification.
Differential Revision: https://phab.mercurial-scm.org/D5266
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 13 Nov 2018 12:30:59 -0800 |
parents | 8c7ecd32ccce |
children | 348352658e4b 197f092b2cd9 |
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# hgweb/server.py - The standalone hg web server. # # Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import errno import os import socket import sys import traceback import wsgiref.validate from ..i18n import _ from .. import ( encoding, error, pycompat, util, ) httpservermod = util.httpserver socketserver = util.socketserver urlerr = util.urlerr urlreq = util.urlreq from . import ( common, ) def _splitURI(uri): """Return path and query that has been split from uri Just like CGI environment, the path is unquoted, the query is not. """ if r'?' in uri: path, query = uri.split(r'?', 1) else: path, query = uri, r'' return urlreq.unquote(path), query class _error_logger(object): def __init__(self, handler): self.handler = handler def flush(self): pass def write(self, str): self.writelines(str.split('\n')) def writelines(self, seq): for msg in seq: self.handler.log_error("HG error: %s", msg) class _httprequesthandler(httpservermod.basehttprequesthandler): url_scheme = 'http' @staticmethod def preparehttpserver(httpserver, ui): """Prepare .socket of new HTTPServer instance""" def __init__(self, *args, **kargs): self.protocol_version = r'HTTP/1.1' httpservermod.basehttprequesthandler.__init__(self, *args, **kargs) def _log_any(self, fp, format, *args): fp.write(pycompat.sysbytes( r"%s - - [%s] %s" % (self.client_address[0], self.log_date_time_string(), format % args)) + '\n') fp.flush() def log_error(self, format, *args): self._log_any(self.server.errorlog, format, *args) def log_message(self, format, *args): self._log_any(self.server.accesslog, format, *args) def log_request(self, code=r'-', size=r'-'): xheaders = [] if util.safehasattr(self, 'headers'): xheaders = [h for h in self.headers.items() if h[0].startswith(r'x-')] self.log_message(r'"%s" %s %s%s', self.requestline, str(code), str(size), r''.join([r' %s:%s' % h for h in sorted(xheaders)])) def do_write(self): try: self.do_hgweb() except socket.error as inst: if inst[0] != errno.EPIPE: raise def do_POST(self): try: self.do_write() except Exception: self._start_response(r"500 Internal Server Error", []) self._write(b"Internal Server Error") self._done() tb = r"".join(traceback.format_exception(*sys.exc_info())) # We need a native-string newline to poke in the log # message, because we won't get a newline when using an # r-string. This is the easy way out. newline = chr(10) self.log_error(r"Exception happened during processing " r"request '%s':%s%s", self.path, newline, tb) def do_PUT(self): self.do_POST() def do_GET(self): self.do_POST() def do_hgweb(self): self.sent_headers = False path, query = _splitURI(self.path) # Ensure the slicing of path below is valid if (path != self.server.prefix and not path.startswith(self.server.prefix + b'/')): self._start_response(pycompat.strurl(common.statusmessage(404)), []) self._write(b"Not Found") self._done() return env = {} env[r'GATEWAY_INTERFACE'] = r'CGI/1.1' env[r'REQUEST_METHOD'] = self.command env[r'SERVER_NAME'] = self.server.server_name env[r'SERVER_PORT'] = str(self.server.server_port) env[r'REQUEST_URI'] = self.path env[r'SCRIPT_NAME'] = pycompat.sysstr(self.server.prefix) env[r'PATH_INFO'] = pycompat.sysstr(path[len(self.server.prefix):]) env[r'REMOTE_HOST'] = self.client_address[0] env[r'REMOTE_ADDR'] = self.client_address[0] env[r'QUERY_STRING'] = query or r'' if pycompat.ispy3: if self.headers.get_content_type() is None: env[r'CONTENT_TYPE'] = self.headers.get_default_type() else: env[r'CONTENT_TYPE'] = self.headers.get_content_type() length = self.headers.get(r'content-length') else: if self.headers.typeheader is None: env[r'CONTENT_TYPE'] = self.headers.type else: env[r'CONTENT_TYPE'] = self.headers.typeheader length = self.headers.getheader(r'content-length') if length: env[r'CONTENT_LENGTH'] = length for header in [h for h in self.headers.keys() if h not in (r'content-type', r'content-length')]: hkey = r'HTTP_' + header.replace(r'-', r'_').upper() hval = self.headers.get(header) hval = hval.replace(r'\n', r'').strip() if hval: env[hkey] = hval env[r'SERVER_PROTOCOL'] = self.request_version env[r'wsgi.version'] = (1, 0) env[r'wsgi.url_scheme'] = pycompat.sysstr(self.url_scheme) if env.get(r'HTTP_EXPECT', '').lower() == '100-continue': self.rfile = common.continuereader(self.rfile, self.wfile.write) env[r'wsgi.input'] = self.rfile env[r'wsgi.errors'] = _error_logger(self) env[r'wsgi.multithread'] = isinstance(self.server, socketserver.ThreadingMixIn) if util.safehasattr(socketserver, 'ForkingMixIn'): env[r'wsgi.multiprocess'] = isinstance(self.server, socketserver.ForkingMixIn) else: env[r'wsgi.multiprocess'] = False env[r'wsgi.run_once'] = 0 wsgiref.validate.check_environ(env) self.saved_status = None self.saved_headers = [] self.length = None self._chunked = None for chunk in self.server.application(env, self._start_response): self._write(chunk) if not self.sent_headers: self.send_headers() self._done() def send_headers(self): if not self.saved_status: raise AssertionError("Sending headers before " "start_response() called") saved_status = self.saved_status.split(None, 1) saved_status[0] = int(saved_status[0]) self.send_response(*saved_status) self.length = None self._chunked = False for h in self.saved_headers: self.send_header(*h) if h[0].lower() == r'content-length': self.length = int(h[1]) if (self.length is None and saved_status[0] != common.HTTP_NOT_MODIFIED): self._chunked = (not self.close_connection and self.request_version == r'HTTP/1.1') if self._chunked: self.send_header(r'Transfer-Encoding', r'chunked') else: self.send_header(r'Connection', r'close') self.end_headers() self.sent_headers = True def _start_response(self, http_status, headers, exc_info=None): assert isinstance(http_status, str) code, msg = http_status.split(None, 1) code = int(code) self.saved_status = http_status bad_headers = (r'connection', r'transfer-encoding') self.saved_headers = [h for h in headers if h[0].lower() not in bad_headers] return self._write def _write(self, data): if not self.saved_status: raise AssertionError("data written before start_response() called") elif not self.sent_headers: self.send_headers() if self.length is not None: if len(data) > self.length: raise AssertionError("Content-length header sent, but more " "bytes than specified are being written.") self.length = self.length - len(data) elif self._chunked and data: data = '%x\r\n%s\r\n' % (len(data), data) self.wfile.write(data) self.wfile.flush() def _done(self): if self._chunked: self.wfile.write('0\r\n\r\n') self.wfile.flush() def version_string(self): if self.server.serverheader: return encoding.strfromlocal(self.server.serverheader) return httpservermod.basehttprequesthandler.version_string(self) class _httprequesthandlerssl(_httprequesthandler): """HTTPS handler based on Python's ssl module""" url_scheme = 'https' @staticmethod def preparehttpserver(httpserver, ui): try: from .. import sslutil sslutil.modernssl except ImportError: raise error.Abort(_("SSL support is unavailable")) certfile = ui.config('web', 'certificate') # These config options are currently only meant for testing. Use # at your own risk. cafile = ui.config('devel', 'servercafile') reqcert = ui.configbool('devel', 'serverrequirecert') httpserver.socket = sslutil.wrapserversocket(httpserver.socket, ui, certfile=certfile, cafile=cafile, requireclientcert=reqcert) def setup(self): self.connection = self.request self.rfile = self.request.makefile(r"rb", self.rbufsize) self.wfile = self.request.makefile(r"wb", self.wbufsize) try: import threading threading.activeCount() # silence pyflakes and bypass demandimport _mixin = socketserver.ThreadingMixIn except ImportError: if util.safehasattr(os, "fork"): _mixin = socketserver.ForkingMixIn else: class _mixin(object): pass def openlog(opt, default): if opt and opt != '-': return open(opt, 'ab') return default class MercurialHTTPServer(_mixin, httpservermod.httpserver, object): # SO_REUSEADDR has broken semantics on windows if pycompat.iswindows: allow_reuse_address = 0 def __init__(self, ui, app, addr, handler, **kwargs): httpservermod.httpserver.__init__(self, addr, handler, **kwargs) self.daemon_threads = True self.application = app handler.preparehttpserver(self, ui) prefix = ui.config('web', 'prefix') if prefix: prefix = '/' + prefix.strip('/') self.prefix = prefix alog = openlog(ui.config('web', 'accesslog'), ui.fout) elog = openlog(ui.config('web', 'errorlog'), ui.ferr) self.accesslog = alog self.errorlog = elog self.addr, self.port = self.socket.getsockname()[0:2] self.fqaddr = socket.getfqdn(addr[0]) self.serverheader = ui.config('web', 'server-header') class IPv6HTTPServer(MercurialHTTPServer): address_family = getattr(socket, 'AF_INET6', None) def __init__(self, *args, **kwargs): if self.address_family is None: raise error.RepoError(_('IPv6 is not available on this system')) super(IPv6HTTPServer, self).__init__(*args, **kwargs) def create_server(ui, app): if ui.config('web', 'certificate'): handler = _httprequesthandlerssl else: handler = _httprequesthandler if ui.configbool('web', 'ipv6'): cls = IPv6HTTPServer else: cls = MercurialHTTPServer # ugly hack due to python issue5853 (for threaded use) try: import mimetypes mimetypes.init() except UnicodeDecodeError: # Python 2.x's mimetypes module attempts to decode strings # from Windows' ANSI APIs as ascii (fail), then re-encode them # as ascii (clown fail), because the default Python Unicode # codec is hardcoded as ascii. sys.argv # unwrap demand-loader so that reload() works reload(sys) # resurrect sys.setdefaultencoding() oldenc = sys.getdefaultencoding() sys.setdefaultencoding("latin1") # or any full 8-bit encoding mimetypes.init() sys.setdefaultencoding(oldenc) address = ui.config('web', 'address') port = util.getport(ui.config('web', 'port')) try: return cls(ui, app, (address, port), handler) except socket.error as inst: raise error.Abort(_("cannot start server at '%s:%d': %s") % (address, port, encoding.strtolocal(inst.args[1])))