##// END OF EJS Templates
wireproto: define and implement protocol for issuing requests...
wireproto: define and implement protocol for issuing requests The existing HTTP and SSH wire protocols suffer from a host of flaws and shortcomings. I've been wanting to rewrite the protocol for a while now. Supporting partial clone - which will require new wire protocol commands and capabilities - and other advanced server functionality will be much easier if we start from a clean slate and don't have to be constrained by limitations of the existing wire protocol. This commit starts to introduce a new data exchange format for use over the wire protocol. The new protocol is built on top of "frames," which are atomic units of metadata + data. Frames will make it easier to implement proxies and other mechanisms that want to inspect data without having to maintain state. The existing frame metadata is very minimal and it will evolve heavily. (We will eventually support things like concurrent requests, out-of-order responses, compression, side-channels for status updates, etc. Some of these will require additions to the frame header.) Another benefit of frames is that all reads are of a fixed size. A reader works by consuming a frame header, extracting the payload length, then reading that many bytes. No lookahead, buffering, or memory reallocations are needed. The new protocol attempts to be transport agnostic. I want all that's required to use the new protocol to be a pair of unidirectional, half-duplex pipes. (Yes, we will eventually make use of full-duplex pipes, but that's for another commit.) Notably, when the SSH transport switches to this new protocol, stderr will be unused. This is by design: the lack of stderr on HTTP harms protocol behavior there. By shoehorning everything into a pair of pipes, we can have more consistent behavior across transports. We currently only define the client side parts of the new protocol, specifically the bits for requesting that a command run. This keeps the new code and feature small and somewhat easy to review. We add support to `hg debugwireproto` for writing frames into HTTP request bodies. Our tests that issue commands to the new HTTP endpoint have been updated to transmit frames. The server bits haven't been touched to consume the frames yet. This will occur in the next commit... Astute readers may notice that the command name is transmitted in both the HTTP request URL and the command request frame. This is partially a kludge from me initially implementing the frame-based protocol for SSH first. But it is also a feature: I intend to eventually support issuing multiple commands per HTTP request. This will allow us to replace the abomination that is the "batch" wire protocol command with a protocol-level mechanism for performing multi-dispatch. Because I want the frame-based protocol to be as similar as possible across transports, I'd rather we (redundantly) include the command name in the frame than differ behavior between transports that have out-of-band routing information (like HTTP) readily available. Differential Revision: https://phab.mercurial-scm.org/D2851

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url.py
582 lines | 20.8 KiB | text/x-python | PythonLexer
# url.py - HTTP handling for mercurial
#
# 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>
#
# 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 base64
import os
import socket
from .i18n import _
from . import (
encoding,
error,
httpconnection as httpconnectionmod,
keepalive,
pycompat,
sslutil,
urllibcompat,
util,
)
httplib = util.httplib
stringio = util.stringio
urlerr = util.urlerr
urlreq = util.urlreq
def escape(s, quote=None):
'''Replace special characters "&", "<" and ">" to HTML-safe sequences.
If the optional flag quote is true, the quotation mark character (")
is also translated.
This is the same as cgi.escape in Python, but always operates on
bytes, whereas cgi.escape in Python 3 only works on unicodes.
'''
s = s.replace(b"&", b"&amp;")
s = s.replace(b"<", b"&lt;")
s = s.replace(b">", b"&gt;")
if quote:
s = s.replace(b'"', b"&quot;")
return s
class passwordmgr(object):
def __init__(self, ui, passwddb):
self.ui = ui
self.passwddb = passwddb
def add_password(self, realm, uri, user, passwd):
return self.passwddb.add_password(realm, uri, user, passwd)
def find_user_password(self, realm, authuri):
authinfo = self.passwddb.find_user_password(realm, authuri)
user, passwd = authinfo
if user and passwd:
self._writedebug(user, passwd)
return (user, passwd)
if not user or not passwd:
res = httpconnectionmod.readauthforuri(self.ui, authuri, user)
if res:
group, auth = res
user, passwd = auth.get('username'), auth.get('password')
self.ui.debug("using auth.%s.* for authentication\n" % group)
if not user or not passwd:
u = util.url(pycompat.bytesurl(authuri))
u.query = None
if not self.ui.interactive():
raise error.Abort(_('http authorization required for %s') %
util.hidepassword(bytes(u)))
self.ui.write(_("http authorization required for %s\n") %
util.hidepassword(bytes(u)))
self.ui.write(_("realm: %s\n") % pycompat.bytesurl(realm))
if user:
self.ui.write(_("user: %s\n") % user)
else:
user = self.ui.prompt(_("user:"), default=None)
if not passwd:
passwd = self.ui.getpass()
self.passwddb.add_password(realm, authuri, user, passwd)
self._writedebug(user, passwd)
return (user, passwd)
def _writedebug(self, user, passwd):
msg = _('http auth: user %s, password %s\n')
self.ui.debug(msg % (user, passwd and '*' * len(passwd) or 'not set'))
def find_stored_password(self, authuri):
return self.passwddb.find_user_password(None, authuri)
class proxyhandler(urlreq.proxyhandler):
def __init__(self, ui):
proxyurl = (ui.config("http_proxy", "host") or
encoding.environ.get('http_proxy'))
# XXX proxyauthinfo = None
if proxyurl:
# proxy can be proper url or host[:port]
if not (proxyurl.startswith('http:') or
proxyurl.startswith('https:')):
proxyurl = 'http://' + proxyurl + '/'
proxy = util.url(proxyurl)
if not proxy.user:
proxy.user = ui.config("http_proxy", "user")
proxy.passwd = ui.config("http_proxy", "passwd")
# see if we should use a proxy for this url
no_list = ["localhost", "127.0.0.1"]
no_list.extend([p.lower() for
p in ui.configlist("http_proxy", "no")])
no_list.extend([p.strip().lower() for
p in encoding.environ.get("no_proxy", '').split(',')
if p.strip()])
# "http_proxy.always" config is for running tests on localhost
if ui.configbool("http_proxy", "always"):
self.no_list = []
else:
self.no_list = no_list
proxyurl = bytes(proxy)
proxies = {'http': proxyurl, 'https': proxyurl}
ui.debug('proxying through %s\n' % util.hidepassword(proxyurl))
else:
proxies = {}
urlreq.proxyhandler.__init__(self, proxies)
self.ui = ui
def proxy_open(self, req, proxy, type_):
host = urllibcompat.gethost(req).split(':')[0]
for e in self.no_list:
if host == e:
return None
if e.startswith('*.') and host.endswith(e[2:]):
return None
if e.startswith('.') and host.endswith(e[1:]):
return None
return urlreq.proxyhandler.proxy_open(self, req, proxy, type_)
def _gen_sendfile(orgsend):
def _sendfile(self, data):
# send a file
if isinstance(data, httpconnectionmod.httpsendfile):
# if auth required, some data sent twice, so rewind here
data.seek(0)
for chunk in util.filechunkiter(data):
orgsend(self, chunk)
else:
orgsend(self, data)
return _sendfile
has_https = util.safehasattr(urlreq, 'httpshandler')
class httpconnection(keepalive.HTTPConnection):
# must be able to send big bundle as stream.
send = _gen_sendfile(keepalive.HTTPConnection.send)
def getresponse(self):
proxyres = getattr(self, 'proxyres', None)
if proxyres:
if proxyres.will_close:
self.close()
self.proxyres = None
return proxyres
return keepalive.HTTPConnection.getresponse(self)
# general transaction handler to support different ways to handle
# HTTPS proxying before and after Python 2.6.3.
def _generic_start_transaction(handler, h, req):
tunnel_host = getattr(req, '_tunnel_host', None)
if tunnel_host:
if tunnel_host[:7] not in ['http://', 'https:/']:
tunnel_host = 'https://' + tunnel_host
new_tunnel = True
else:
tunnel_host = urllibcompat.getselector(req)
new_tunnel = False
if new_tunnel or tunnel_host == urllibcompat.getfullurl(req): # has proxy
u = util.url(tunnel_host)
if new_tunnel or u.scheme == 'https': # only use CONNECT for HTTPS
h.realhostport = ':'.join([u.host, (u.port or '443')])
h.headers = req.headers.copy()
h.headers.update(handler.parent.addheaders)
return
h.realhostport = None
h.headers = None
def _generic_proxytunnel(self):
proxyheaders = dict(
[(x, self.headers[x]) for x in self.headers
if x.lower().startswith('proxy-')])
self.send('CONNECT %s HTTP/1.0\r\n' % self.realhostport)
for header in proxyheaders.iteritems():
self.send('%s: %s\r\n' % header)
self.send('\r\n')
# majority of the following code is duplicated from
# httplib.HTTPConnection as there are no adequate places to
# override functions to provide the needed functionality
res = self.response_class(self.sock,
strict=self.strict,
method=self._method)
while True:
version, status, reason = res._read_status()
if status != httplib.CONTINUE:
break
# skip lines that are all whitespace
list(iter(lambda: res.fp.readline().strip(), ''))
res.status = status
res.reason = reason.strip()
if res.status == 200:
# skip lines until we find a blank line
list(iter(res.fp.readline, '\r\n'))
return True
if version == 'HTTP/1.0':
res.version = 10
elif version.startswith('HTTP/1.'):
res.version = 11
elif version == 'HTTP/0.9':
res.version = 9
else:
raise httplib.UnknownProtocol(version)
if res.version == 9:
res.length = None
res.chunked = 0
res.will_close = 1
res.msg = httplib.HTTPMessage(stringio())
return False
res.msg = httplib.HTTPMessage(res.fp)
res.msg.fp = None
# are we using the chunked-style of transfer encoding?
trenc = res.msg.getheader('transfer-encoding')
if trenc and trenc.lower() == "chunked":
res.chunked = 1
res.chunk_left = None
else:
res.chunked = 0
# will the connection close at the end of the response?
res.will_close = res._check_close()
# do we have a Content-Length?
# NOTE: RFC 2616, section 4.4, #3 says we ignore this if
# transfer-encoding is "chunked"
length = res.msg.getheader('content-length')
if length and not res.chunked:
try:
res.length = int(length)
except ValueError:
res.length = None
else:
if res.length < 0: # ignore nonsensical negative lengths
res.length = None
else:
res.length = None
# does the body have a fixed length? (of zero)
if (status == httplib.NO_CONTENT or status == httplib.NOT_MODIFIED or
100 <= status < 200 or # 1xx codes
res._method == 'HEAD'):
res.length = 0
# if the connection remains open, and we aren't using chunked, and
# a content-length was not provided, then assume that the connection
# WILL close.
if (not res.will_close and
not res.chunked and
res.length is None):
res.will_close = 1
self.proxyres = res
return False
class httphandler(keepalive.HTTPHandler):
def http_open(self, req):
return self.do_open(httpconnection, req)
def _start_transaction(self, h, req):
_generic_start_transaction(self, h, req)
return keepalive.HTTPHandler._start_transaction(self, h, req)
class logginghttpconnection(keepalive.HTTPConnection):
def __init__(self, createconn, *args, **kwargs):
keepalive.HTTPConnection.__init__(self, *args, **kwargs)
self._create_connection = createconn
class logginghttphandler(httphandler):
"""HTTP handler that logs socket I/O."""
def __init__(self, logfh, name, observeropts):
super(logginghttphandler, self).__init__()
self._logfh = logfh
self._logname = name
self._observeropts = observeropts
# do_open() calls the passed class to instantiate an HTTPConnection. We
# pass in a callable method that creates a custom HTTPConnection instance
# whose callback to create the socket knows how to proxy the socket.
def http_open(self, req):
return self.do_open(self._makeconnection, req)
def _makeconnection(self, *args, **kwargs):
def createconnection(*args, **kwargs):
sock = socket.create_connection(*args, **kwargs)
return util.makeloggingsocket(self._logfh, sock, self._logname,
**self._observeropts)
return logginghttpconnection(createconnection, *args, **kwargs)
if has_https:
class httpsconnection(httplib.HTTPConnection):
response_class = keepalive.HTTPResponse
default_port = httplib.HTTPS_PORT
# must be able to send big bundle as stream.
send = _gen_sendfile(keepalive.safesend)
getresponse = keepalive.wrapgetresponse(httplib.HTTPConnection)
def __init__(self, host, port=None, key_file=None, cert_file=None,
*args, **kwargs):
httplib.HTTPConnection.__init__(self, host, port, *args, **kwargs)
self.key_file = key_file
self.cert_file = cert_file
def connect(self):
self.sock = socket.create_connection((self.host, self.port))
host = self.host
if self.realhostport: # use CONNECT proxy
_generic_proxytunnel(self)
host = self.realhostport.rsplit(':', 1)[0]
self.sock = sslutil.wrapsocket(
self.sock, self.key_file, self.cert_file, ui=self.ui,
serverhostname=host)
sslutil.validatesocket(self.sock)
class httpshandler(keepalive.KeepAliveHandler, urlreq.httpshandler):
def __init__(self, ui):
keepalive.KeepAliveHandler.__init__(self)
urlreq.httpshandler.__init__(self)
self.ui = ui
self.pwmgr = passwordmgr(self.ui,
self.ui.httppasswordmgrdb)
def _start_transaction(self, h, req):
_generic_start_transaction(self, h, req)
return keepalive.KeepAliveHandler._start_transaction(self, h, req)
def https_open(self, req):
# urllibcompat.getfullurl() does not contain credentials
# and we may need them to match the certificates.
url = urllibcompat.getfullurl(req)
user, password = self.pwmgr.find_stored_password(url)
res = httpconnectionmod.readauthforuri(self.ui, url, user)
if res:
group, auth = res
self.auth = auth
self.ui.debug("using auth.%s.* for authentication\n" % group)
else:
self.auth = None
return self.do_open(self._makeconnection, req)
def _makeconnection(self, host, port=None, *args, **kwargs):
keyfile = None
certfile = None
if len(args) >= 1: # key_file
keyfile = args[0]
if len(args) >= 2: # cert_file
certfile = args[1]
args = args[2:]
# if the user has specified different key/cert files in
# hgrc, we prefer these
if self.auth and 'key' in self.auth and 'cert' in self.auth:
keyfile = self.auth['key']
certfile = self.auth['cert']
conn = httpsconnection(host, port, keyfile, certfile, *args,
**kwargs)
conn.ui = self.ui
return conn
class httpdigestauthhandler(urlreq.httpdigestauthhandler):
def __init__(self, *args, **kwargs):
urlreq.httpdigestauthhandler.__init__(self, *args, **kwargs)
self.retried_req = None
def reset_retry_count(self):
# Python 2.6.5 will call this on 401 or 407 errors and thus loop
# forever. We disable reset_retry_count completely and reset in
# http_error_auth_reqed instead.
pass
def http_error_auth_reqed(self, auth_header, host, req, headers):
# Reset the retry counter once for each request.
if req is not self.retried_req:
self.retried_req = req
self.retried = 0
return urlreq.httpdigestauthhandler.http_error_auth_reqed(
self, auth_header, host, req, headers)
class httpbasicauthhandler(urlreq.httpbasicauthhandler):
def __init__(self, *args, **kwargs):
self.auth = None
urlreq.httpbasicauthhandler.__init__(self, *args, **kwargs)
self.retried_req = None
def http_request(self, request):
if self.auth:
request.add_unredirected_header(self.auth_header, self.auth)
return request
def https_request(self, request):
if self.auth:
request.add_unredirected_header(self.auth_header, self.auth)
return request
def reset_retry_count(self):
# Python 2.6.5 will call this on 401 or 407 errors and thus loop
# forever. We disable reset_retry_count completely and reset in
# http_error_auth_reqed instead.
pass
def http_error_auth_reqed(self, auth_header, host, req, headers):
# Reset the retry counter once for each request.
if req is not self.retried_req:
self.retried_req = req
self.retried = 0
return urlreq.httpbasicauthhandler.http_error_auth_reqed(
self, auth_header, host, req, headers)
def retry_http_basic_auth(self, host, req, realm):
user, pw = self.passwd.find_user_password(
realm, urllibcompat.getfullurl(req))
if pw is not None:
raw = "%s:%s" % (pycompat.bytesurl(user), pycompat.bytesurl(pw))
auth = r'Basic %s' % pycompat.strurl(base64.b64encode(raw).strip())
if req.get_header(self.auth_header, None) == auth:
return None
self.auth = auth
req.add_unredirected_header(self.auth_header, auth)
return self.parent.open(req)
else:
return None
class cookiehandler(urlreq.basehandler):
def __init__(self, ui):
self.cookiejar = None
cookiefile = ui.config('auth', 'cookiefile')
if not cookiefile:
return
cookiefile = util.expandpath(cookiefile)
try:
cookiejar = util.cookielib.MozillaCookieJar(cookiefile)
cookiejar.load()
self.cookiejar = cookiejar
except util.cookielib.LoadError as e:
ui.warn(_('(error loading cookie file %s: %s; continuing without '
'cookies)\n') % (cookiefile, util.forcebytestr(e)))
def http_request(self, request):
if self.cookiejar:
self.cookiejar.add_cookie_header(request)
return request
def https_request(self, request):
if self.cookiejar:
self.cookiejar.add_cookie_header(request)
return request
handlerfuncs = []
def opener(ui, authinfo=None, useragent=None, loggingfh=None,
loggingname=b's', loggingopts=None, sendaccept=True):
'''
construct an opener suitable for urllib2
authinfo will be added to the password manager
The opener can be configured to log socket events if the various
``logging*`` arguments are specified.
``loggingfh`` denotes a file object to log events to.
``loggingname`` denotes the name of the to print when logging.
``loggingopts`` is a dict of keyword arguments to pass to the constructed
``util.socketobserver`` instance.
``sendaccept`` allows controlling whether the ``Accept`` request header
is sent. The header is sent by default.
'''
handlers = []
if loggingfh:
handlers.append(logginghttphandler(loggingfh, loggingname,
loggingopts or {}))
# We don't yet support HTTPS when logging I/O. If we attempt to open
# an HTTPS URL, we'll likely fail due to unknown protocol.
else:
handlers.append(httphandler())
if has_https:
handlers.append(httpshandler(ui))
handlers.append(proxyhandler(ui))
passmgr = passwordmgr(ui, ui.httppasswordmgrdb)
if authinfo is not None:
realm, uris, user, passwd = authinfo
saveduser, savedpass = passmgr.find_stored_password(uris[0])
if user != saveduser or passwd:
passmgr.add_password(realm, uris, user, passwd)
ui.debug('http auth: user %s, password %s\n' %
(user, passwd and '*' * len(passwd) or 'not set'))
handlers.extend((httpbasicauthhandler(passmgr),
httpdigestauthhandler(passmgr)))
handlers.extend([h(ui, passmgr) for h in handlerfuncs])
handlers.append(cookiehandler(ui))
opener = urlreq.buildopener(*handlers)
# The user agent should should *NOT* be used by servers for e.g.
# protocol detection or feature negotiation: there are other
# facilities for that.
#
# "mercurial/proto-1.0" was the original user agent string and
# exists for backwards compatibility reasons.
#
# The "(Mercurial %s)" string contains the distribution
# name and version. Other client implementations should choose their
# own distribution name. Since servers should not be using the user
# agent string for anything, clients should be able to define whatever
# user agent they deem appropriate.
#
# The custom user agent is for lfs, because unfortunately some servers
# do look at this value.
if not useragent:
agent = 'mercurial/proto-1.0 (Mercurial %s)' % util.version()
opener.addheaders = [(r'User-agent', pycompat.sysstr(agent))]
else:
opener.addheaders = [(r'User-agent', pycompat.sysstr(useragent))]
# This header should only be needed by wire protocol requests. But it has
# been sent on all requests since forever. We keep sending it for backwards
# compatibility reasons. Modern versions of the wire protocol use
# X-HgProto-<N> for advertising client support.
if sendaccept:
opener.addheaders.append((r'Accept', r'application/mercurial-0.1'))
return opener
def open(ui, url_, data=None):
u = util.url(url_)
if u.scheme:
u.scheme = u.scheme.lower()
url_, authinfo = u.authinfo()
else:
path = util.normpath(os.path.abspath(url_))
url_ = 'file://' + urlreq.pathname2url(path)
authinfo = None
return opener(ui, authinfo).open(pycompat.strurl(url_), data)