httppeer: always add x-hg* headers to Vary header
Before, we manually updated the Vary header value for each
header contributing to it.
All X-Hg* headers are reserved for the Mercurial protocol and
could have caching implications. So it makes sense to always add
these headers to Vary.
A test revealed that X-HgArgs-Post wasn't being added to Vary.
This is only sent on POST requests. POST requests generally
aren't cacheable. However, it is possible if the server sends
the appropriate headers. Mercurial shouldn't be sending those
headers. But let's not take any chances.
Differential Revision: https://phab.mercurial-scm.org/D3240
# httppeer.py - HTTP repository proxy classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.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 io
import os
import socket
import struct
import tempfile
from .i18n import _
from .thirdparty import (
cbor,
)
from . import (
bundle2,
error,
httpconnection,
pycompat,
statichttprepo,
url as urlmod,
util,
wireproto,
wireprotoframing,
wireprotov2server,
)
httplib = util.httplib
urlerr = util.urlerr
urlreq = util.urlreq
def encodevalueinheaders(value, header, limit):
"""Encode a string value into multiple HTTP headers.
``value`` will be encoded into 1 or more HTTP headers with the names
``header-<N>`` where ``<N>`` is an integer starting at 1. Each header
name + value will be at most ``limit`` bytes long.
Returns an iterable of 2-tuples consisting of header names and
values as native strings.
"""
# HTTP Headers are ASCII. Python 3 requires them to be unicodes,
# not bytes. This function always takes bytes in as arguments.
fmt = pycompat.strurl(header) + r'-%s'
# Note: it is *NOT* a bug that the last bit here is a bytestring
# and not a unicode: we're just getting the encoded length anyway,
# and using an r-string to make it portable between Python 2 and 3
# doesn't work because then the \r is a literal backslash-r
# instead of a carriage return.
valuelen = limit - len(fmt % r'000') - len(': \r\n')
result = []
n = 0
for i in xrange(0, len(value), valuelen):
n += 1
result.append((fmt % str(n), pycompat.strurl(value[i:i + valuelen])))
return result
def _wraphttpresponse(resp):
"""Wrap an HTTPResponse with common error handlers.
This ensures that any I/O from any consumer raises the appropriate
error and messaging.
"""
origread = resp.read
class readerproxy(resp.__class__):
def read(self, size=None):
try:
return origread(size)
except httplib.IncompleteRead as e:
# e.expected is an integer if length known or None otherwise.
if e.expected:
msg = _('HTTP request error (incomplete response; '
'expected %d bytes got %d)') % (e.expected,
len(e.partial))
else:
msg = _('HTTP request error (incomplete response)')
raise error.PeerTransportError(
msg,
hint=_('this may be an intermittent network failure; '
'if the error persists, consider contacting the '
'network or server operator'))
except httplib.HTTPException as e:
raise error.PeerTransportError(
_('HTTP request error (%s)') % e,
hint=_('this may be an intermittent network failure; '
'if the error persists, consider contacting the '
'network or server operator'))
resp.__class__ = readerproxy
class _multifile(object):
def __init__(self, *fileobjs):
for f in fileobjs:
if not util.safehasattr(f, 'length'):
raise ValueError(
'_multifile only supports file objects that '
'have a length but this one does not:', type(f), f)
self._fileobjs = fileobjs
self._index = 0
@property
def length(self):
return sum(f.length for f in self._fileobjs)
def read(self, amt=None):
if amt <= 0:
return ''.join(f.read() for f in self._fileobjs)
parts = []
while amt and self._index < len(self._fileobjs):
parts.append(self._fileobjs[self._index].read(amt))
got = len(parts[-1])
if got < amt:
self._index += 1
amt -= got
return ''.join(parts)
def seek(self, offset, whence=os.SEEK_SET):
if whence != os.SEEK_SET:
raise NotImplementedError(
'_multifile does not support anything other'
' than os.SEEK_SET for whence on seek()')
if offset != 0:
raise NotImplementedError(
'_multifile only supports seeking to start, but that '
'could be fixed if you need it')
for f in self._fileobjs:
f.seek(0)
self._index = 0
def makev1commandrequest(ui, requestbuilder, caps, capablefn,
repobaseurl, cmd, args):
"""Make an HTTP request to run a command for a version 1 client.
``caps`` is a set of known server capabilities. The value may be
None if capabilities are not yet known.
``capablefn`` is a function to evaluate a capability.
``cmd``, ``args``, and ``data`` define the command, its arguments, and
raw data to pass to it.
"""
if cmd == 'pushkey':
args['data'] = ''
data = args.pop('data', None)
headers = args.pop('headers', {})
ui.debug("sending %s command\n" % cmd)
q = [('cmd', cmd)]
headersize = 0
# Important: don't use self.capable() here or else you end up
# with infinite recursion when trying to look up capabilities
# for the first time.
postargsok = caps is not None and 'httppostargs' in caps
# Send arguments via POST.
if postargsok and args:
strargs = urlreq.urlencode(sorted(args.items()))
if not data:
data = strargs
else:
if isinstance(data, bytes):
i = io.BytesIO(data)
i.length = len(data)
data = i
argsio = io.BytesIO(strargs)
argsio.length = len(strargs)
data = _multifile(argsio, data)
headers[r'X-HgArgs-Post'] = len(strargs)
elif args:
# Calling self.capable() can infinite loop if we are calling
# "capabilities". But that command should never accept wire
# protocol arguments. So this should never happen.
assert cmd != 'capabilities'
httpheader = capablefn('httpheader')
if httpheader:
headersize = int(httpheader.split(',', 1)[0])
# Send arguments via HTTP headers.
if headersize > 0:
# The headers can typically carry more data than the URL.
encargs = urlreq.urlencode(sorted(args.items()))
for header, value in encodevalueinheaders(encargs, 'X-HgArg',
headersize):
headers[header] = value
# Send arguments via query string (Mercurial <1.9).
else:
q += sorted(args.items())
qs = '?%s' % urlreq.urlencode(q)
cu = "%s%s" % (repobaseurl, qs)
size = 0
if util.safehasattr(data, 'length'):
size = data.length
elif data is not None:
size = len(data)
if data is not None and r'Content-Type' not in headers:
headers[r'Content-Type'] = r'application/mercurial-0.1'
# Tell the server we accept application/mercurial-0.2 and multiple
# compression formats if the server is capable of emitting those
# payloads.
protoparams = {'partial-pull'}
mediatypes = set()
if caps is not None:
mt = capablefn('httpmediatype')
if mt:
protoparams.add('0.1')
mediatypes = set(mt.split(','))
if '0.2tx' in mediatypes:
protoparams.add('0.2')
if '0.2tx' in mediatypes and capablefn('compression'):
# We /could/ compare supported compression formats and prune
# non-mutually supported or error if nothing is mutually supported.
# For now, send the full list to the server and have it error.
comps = [e.wireprotosupport().name for e in
util.compengines.supportedwireengines(util.CLIENTROLE)]
protoparams.add('comp=%s' % ','.join(comps))
if protoparams:
protoheaders = encodevalueinheaders(' '.join(sorted(protoparams)),
'X-HgProto',
headersize or 1024)
for header, value in protoheaders:
headers[header] = value
varyheaders = []
for header in headers:
if header.lower().startswith(r'x-hg'):
varyheaders.append(header)
if varyheaders:
headers[r'Vary'] = r','.join(sorted(varyheaders))
req = requestbuilder(pycompat.strurl(cu), data, headers)
if data is not None:
ui.debug("sending %d bytes\n" % size)
req.add_unredirected_header(r'Content-Length', r'%d' % size)
return req, cu, qs
def sendrequest(ui, opener, req):
"""Send a prepared HTTP request.
Returns the response object.
"""
if (ui.debugflag
and ui.configbool('devel', 'debug.peer-request')):
dbg = ui.debug
line = 'devel-peer-request: %s\n'
dbg(line % '%s %s' % (req.get_method(), req.get_full_url()))
hgargssize = None
for header, value in sorted(req.header_items()):
if header.startswith('X-hgarg-'):
if hgargssize is None:
hgargssize = 0
hgargssize += len(value)
else:
dbg(line % ' %s %s' % (header, value))
if hgargssize is not None:
dbg(line % ' %d bytes of commands arguments in headers'
% hgargssize)
if req.has_data():
data = req.get_data()
length = getattr(data, 'length', None)
if length is None:
length = len(data)
dbg(line % ' %d bytes of data' % length)
start = util.timer()
try:
res = opener.open(req)
except urlerr.httperror as inst:
if inst.code == 401:
raise error.Abort(_('authorization failed'))
raise
except httplib.HTTPException as inst:
ui.debug('http error requesting %s\n' %
util.hidepassword(req.get_full_url()))
ui.traceback()
raise IOError(None, inst)
finally:
if ui.configbool('devel', 'debug.peer-request'):
dbg(line % ' finished in %.4f seconds (%s)'
% (util.timer() - start, res.code))
# Insert error handlers for common I/O failures.
_wraphttpresponse(res)
return res
def parsev1commandresponse(ui, baseurl, requrl, qs, resp, compressible):
# record the url we got redirected to
respurl = pycompat.bytesurl(resp.geturl())
if respurl.endswith(qs):
respurl = respurl[:-len(qs)]
if baseurl.rstrip('/') != respurl.rstrip('/'):
if not ui.quiet:
ui.warn(_('real URL is %s\n') % respurl)
try:
proto = pycompat.bytesurl(resp.getheader(r'content-type', r''))
except AttributeError:
proto = pycompat.bytesurl(resp.headers.get(r'content-type', r''))
safeurl = util.hidepassword(baseurl)
if proto.startswith('application/hg-error'):
raise error.OutOfBandError(resp.read())
# Pre 1.0 versions of Mercurial used text/plain and
# application/hg-changegroup. We don't support such old servers.
if not proto.startswith('application/mercurial-'):
ui.debug("requested URL: '%s'\n" % util.hidepassword(requrl))
raise error.RepoError(
_("'%s' does not appear to be an hg repository:\n"
"---%%<--- (%s)\n%s\n---%%<---\n")
% (safeurl, proto or 'no content-type', resp.read(1024)))
try:
version = proto.split('-', 1)[1]
version_info = tuple([int(n) for n in version.split('.')])
except ValueError:
raise error.RepoError(_("'%s' sent a broken Content-Type "
"header (%s)") % (safeurl, proto))
# TODO consider switching to a decompression reader that uses
# generators.
if version_info == (0, 1):
if compressible:
resp = util.compengines['zlib'].decompressorreader(resp)
elif version_info == (0, 2):
# application/mercurial-0.2 always identifies the compression
# engine in the payload header.
elen = struct.unpack('B', resp.read(1))[0]
ename = resp.read(elen)
engine = util.compengines.forwiretype(ename)
resp = engine.decompressorreader(resp)
else:
raise error.RepoError(_("'%s' uses newer protocol %s") %
(safeurl, version))
return respurl, resp
class httppeer(wireproto.wirepeer):
def __init__(self, ui, path, url, opener, requestbuilder, caps):
self.ui = ui
self._path = path
self._url = url
self._caps = caps
self._urlopener = opener
self._requestbuilder = requestbuilder
def __del__(self):
for h in self._urlopener.handlers:
h.close()
getattr(h, "close_all", lambda: None)()
# Begin of ipeerconnection interface.
def url(self):
return self._path
def local(self):
return None
def peer(self):
return self
def canpush(self):
return True
def close(self):
pass
# End of ipeerconnection interface.
# Begin of ipeercommands interface.
def capabilities(self):
return self._caps
# End of ipeercommands interface.
# look up capabilities only when needed
def _callstream(self, cmd, _compressible=False, **args):
args = pycompat.byteskwargs(args)
req, cu, qs = makev1commandrequest(self.ui, self._requestbuilder,
self._caps, self.capable,
self._url, cmd, args)
resp = sendrequest(self.ui, self._urlopener, req)
self._url, resp = parsev1commandresponse(self.ui, self._url, cu, qs,
resp, _compressible)
return resp
def _call(self, cmd, **args):
fp = self._callstream(cmd, **args)
try:
return fp.read()
finally:
# if using keepalive, allow connection to be reused
fp.close()
def _callpush(self, cmd, cg, **args):
# have to stream bundle to a temp file because we do not have
# http 1.1 chunked transfer.
types = self.capable('unbundle')
try:
types = types.split(',')
except AttributeError:
# servers older than d1b16a746db6 will send 'unbundle' as a
# boolean capability. They only support headerless/uncompressed
# bundles.
types = [""]
for x in types:
if x in bundle2.bundletypes:
type = x
break
tempname = bundle2.writebundle(self.ui, cg, None, type)
fp = httpconnection.httpsendfile(self.ui, tempname, "rb")
headers = {r'Content-Type': r'application/mercurial-0.1'}
try:
r = self._call(cmd, data=fp, headers=headers, **args)
vals = r.split('\n', 1)
if len(vals) < 2:
raise error.ResponseError(_("unexpected response:"), r)
return vals
except urlerr.httperror:
# Catch and re-raise these so we don't try and treat them
# like generic socket errors. They lack any values in
# .args on Python 3 which breaks our socket.error block.
raise
except socket.error as err:
if err.args[0] in (errno.ECONNRESET, errno.EPIPE):
raise error.Abort(_('push failed: %s') % err.args[1])
raise error.Abort(err.args[1])
finally:
fp.close()
os.unlink(tempname)
def _calltwowaystream(self, cmd, fp, **args):
fh = None
fp_ = None
filename = None
try:
# dump bundle to disk
fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
fh = os.fdopen(fd, r"wb")
d = fp.read(4096)
while d:
fh.write(d)
d = fp.read(4096)
fh.close()
# start http push
fp_ = httpconnection.httpsendfile(self.ui, filename, "rb")
headers = {r'Content-Type': r'application/mercurial-0.1'}
return self._callstream(cmd, data=fp_, headers=headers, **args)
finally:
if fp_ is not None:
fp_.close()
if fh is not None:
fh.close()
os.unlink(filename)
def _callcompressable(self, cmd, **args):
return self._callstream(cmd, _compressible=True, **args)
def _abort(self, exception):
raise exception
# TODO implement interface for version 2 peers
class httpv2peer(object):
def __init__(self, ui, repourl, opener):
self.ui = ui
if repourl.endswith('/'):
repourl = repourl[:-1]
self.url = repourl
self._opener = opener
# This is an its own attribute to facilitate extensions overriding
# the default type.
self._requestbuilder = urlreq.request
def close(self):
pass
# TODO require to be part of a batched primitive, use futures.
def _call(self, name, **args):
"""Call a wire protocol command with arguments."""
# Having this early has a side-effect of importing wireprotov2server,
# which has the side-effect of ensuring commands are registered.
# TODO modify user-agent to reflect v2.
headers = {
r'Accept': wireprotov2server.FRAMINGTYPE,
r'Content-Type': wireprotov2server.FRAMINGTYPE,
}
# TODO permissions should come from capabilities results.
permission = wireproto.commandsv2[name].permission
if permission not in ('push', 'pull'):
raise error.ProgrammingError('unknown permission type: %s' %
permission)
permission = {
'push': 'rw',
'pull': 'ro',
}[permission]
url = '%s/api/%s/%s/%s' % (self.url, wireprotov2server.HTTPV2,
permission, name)
# TODO this should be part of a generic peer for the frame-based
# protocol.
reactor = wireprotoframing.clientreactor(hasmultiplesend=False,
buffersends=True)
request, action, meta = reactor.callcommand(name, args)
assert action == 'noop'
action, meta = reactor.flushcommands()
assert action == 'sendframes'
body = b''.join(map(bytes, meta['framegen']))
req = self._requestbuilder(pycompat.strurl(url), body, headers)
req.add_unredirected_header(r'Content-Length', r'%d' % len(body))
# TODO unify this code with httppeer.
try:
res = self._opener.open(req)
except urlerr.httperror as e:
if e.code == 401:
raise error.Abort(_('authorization failed'))
raise
except httplib.HTTPException as e:
self.ui.traceback()
raise IOError(None, e)
# TODO validate response type, wrap response to handle I/O errors.
# TODO more robust frame receiver.
results = []
while True:
frame = wireprotoframing.readframe(res)
if frame is None:
break
self.ui.note(_('received %r\n') % frame)
action, meta = reactor.onframerecv(frame)
if action == 'responsedata':
if meta['cbor']:
payload = util.bytesio(meta['data'])
decoder = cbor.CBORDecoder(payload)
while payload.tell() + 1 < len(meta['data']):
results.append(decoder.decode())
else:
results.append(meta['data'])
else:
error.ProgrammingError('unhandled action: %s' % action)
return results
def performhandshake(ui, url, opener, requestbuilder):
# The handshake is a request to the capabilities command.
caps = None
def capable(x):
raise error.ProgrammingError('should not be called')
req, requrl, qs = makev1commandrequest(ui, requestbuilder, caps,
capable, url, 'capabilities',
{})
resp = sendrequest(ui, opener, req)
respurl, resp = parsev1commandresponse(ui, url, requrl, qs, resp,
compressible=False)
try:
rawcaps = resp.read()
finally:
resp.close()
return respurl, set(rawcaps.split())
def makepeer(ui, path, opener=None, requestbuilder=urlreq.request):
"""Construct an appropriate HTTP peer instance.
``opener`` is an ``url.opener`` that should be used to establish
connections, perform HTTP requests.
``requestbuilder`` is the type used for constructing HTTP requests.
It exists as an argument so extensions can override the default.
"""
u = util.url(path)
if u.query or u.fragment:
raise error.Abort(_('unsupported URL component: "%s"') %
(u.query or u.fragment))
# urllib cannot handle URLs with embedded user or passwd.
url, authinfo = u.authinfo()
ui.debug('using %s\n' % url)
opener = opener or urlmod.opener(ui, authinfo)
respurl, caps = performhandshake(ui, url, opener, requestbuilder)
return httppeer(ui, path, respurl, opener, requestbuilder, caps)
def instance(ui, path, create):
if create:
raise error.Abort(_('cannot create new http repository'))
try:
if path.startswith('https:') and not urlmod.has_https:
raise error.Abort(_('Python support for SSL and HTTPS '
'is not installed'))
inst = makepeer(ui, path)
return inst
except error.RepoError as httpexception:
try:
r = statichttprepo.instance(ui, "static-" + path, create)
ui.note(_('(falling back to static-http)\n'))
return r
except error.RepoError:
raise httpexception # use the original http RepoError instead