Mercurial > hg
view mercurial/httpconnection.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 | 5f9d436cd3b7 |
children | c53f0ead5781 |
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# httpconnection.py - urllib2 handler for new http support # # Copyright 2005, 2006, 2007, 2008 Matt Mackall <mpm@selenic.com> # Copyright 2006, 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br> # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com> # Copyright 2011 Google, Inc. # # 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 os from .i18n import _ from . import ( pycompat, util, ) urlerr = util.urlerr urlreq = util.urlreq # moved here from url.py to avoid a cycle class httpsendfile(object): """This is a wrapper around the objects returned by python's "open". Its purpose is to send file-like objects via HTTP. It do however not define a __len__ attribute because the length might be more than Py_ssize_t can handle. """ def __init__(self, ui, *args, **kwargs): self.ui = ui self._data = open(*args, **kwargs) self.seek = self._data.seek self.close = self._data.close self.write = self._data.write self.length = os.fstat(self._data.fileno()).st_size self._pos = 0 # We pass double the max for total because we currently have # to send the bundle twice in the case of a server that # requires authentication. Since we can't know until we try # once whether authentication will be required, just lie to # the user and maybe the push succeeds suddenly at 50%. self._progress = ui.makeprogress(_('sending'), unit=_('kb'), total=(self.length // 1024 * 2)) def read(self, *args, **kwargs): ret = self._data.read(*args, **kwargs) if not ret: self._progress.complete() return ret self._pos += len(ret) self._progress.update(self._pos // 1024) return ret def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() # moved here from url.py to avoid a cycle def readauthforuri(ui, uri, user): uri = pycompat.bytesurl(uri) # Read configuration groups = {} for key, val in ui.configitems('auth'): if key in ('cookiefile',): continue if '.' not in key: ui.warn(_("ignoring invalid [auth] key '%s'\n") % key) continue group, setting = key.rsplit('.', 1) gdict = groups.setdefault(group, {}) if setting in ('username', 'cert', 'key'): val = util.expandpath(val) gdict[setting] = val # Find the best match scheme, hostpath = uri.split('://', 1) bestuser = None bestlen = 0 bestauth = None for group, auth in groups.iteritems(): if user and user != auth.get('username', user): # If a username was set in the URI, the entry username # must either match it or be unset continue prefix = auth.get('prefix') if not prefix: continue p = prefix.split('://', 1) if len(p) > 1: schemes, prefix = [p[0]], p[1] else: schemes = (auth.get('schemes') or 'https').split() if (prefix == '*' or hostpath.startswith(prefix)) and \ (len(prefix) > bestlen or (len(prefix) == bestlen and \ not bestuser and 'username' in auth)) \ and scheme in schemes: bestlen = len(prefix) bestauth = group, auth bestuser = auth.get('username') if user and not bestuser: auth['username'] = user return bestauth