Mercurial > hg
view mercurial/wireprotoserver.py @ 36309:94a1ff16f362
debuginstall: do not parse editor command in posix way on Windows
An editor command is executed by a system shell, which is cmd.exe on Windows.
author | Yuya Nishihara <yuya@tcha.org> |
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date | Sat, 17 Feb 2018 13:13:04 +0900 |
parents | 685bcdd236b5 |
children | 0c231df1ffdc |
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# 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 abc import contextlib import struct import sys from .i18n import _ from . import ( encoding, error, hook, pycompat, util, wireproto, wireprototypes, ) stringio = util.stringio urlerr = util.urlerr urlreq = util.urlreq HTTP_OK = 200 HGTYPE = 'application/mercurial-0.1' HGTYPE2 = 'application/mercurial-0.2' HGERRTYPE = 'application/hg-error' # Names of the SSH protocol implementations. SSHV1 = 'ssh-v1' # This is advertised over the wire. Incremental the counter at the end # to reflect BC breakages. SSHV2 = 'exp-ssh-v2-0001' class baseprotocolhandler(object): """Abstract base class for wire protocol handlers. A wire protocol handler serves as an interface between protocol command handlers and the wire protocol transport layer. Protocol handlers provide methods to read command arguments, redirect stdio for the duration of the request, handle response types, etc. """ __metaclass__ = abc.ABCMeta @abc.abstractproperty def name(self): """The name of the protocol implementation. Used for uniquely identifying the transport type. """ @abc.abstractmethod def getargs(self, args): """return the value for arguments in <args> returns a list of values (same order as <args>)""" @abc.abstractmethod def forwardpayload(self, fp): """Read the raw payload and forward to a file. The payload is read in full before the function returns. """ @abc.abstractmethod def mayberedirectstdio(self): """Context manager to possibly redirect stdio. The context manager yields a file-object like object that receives stdout and stderr output when the context manager is active. Or it yields ``None`` if no I/O redirection occurs. The intent of this context manager is to capture stdio output so it may be sent in the response. Some transports support streaming stdio to the client in real time. For these transports, stdio output won't be captured. """ @abc.abstractmethod def client(self): """Returns a string representation of this client (as bytes).""" def decodevaluefromheaders(req, headerprefix): """Decode a long value from multiple HTTP request headers. Returns the value as a bytes, not a str. """ chunks = [] i = 1 prefix = headerprefix.upper().replace(r'-', r'_') while True: v = req.env.get(r'HTTP_%s_%d' % (prefix, i)) if v is None: break chunks.append(pycompat.bytesurl(v)) i += 1 return ''.join(chunks) class httpv1protocolhandler(baseprotocolhandler): def __init__(self, req, ui): self._req = req self._ui = ui @property def name(self): return 'http-v1' def getargs(self, args): knownargs = self._args() data = {} keys = args.split() for k in keys: if k == '*': star = {} for key in knownargs.keys(): if key != 'cmd' and key not in keys: star[key] = knownargs[key][0] data['*'] = star else: data[k] = knownargs[k][0] return [data[k] for k in keys] def _args(self): args = util.rapply(pycompat.bytesurl, self._req.form.copy()) postlen = int(self._req.env.get(r'HTTP_X_HGARGS_POST', 0)) if postlen: args.update(urlreq.parseqs( self._req.read(postlen), keep_blank_values=True)) return args argvalue = decodevaluefromheaders(self._req, r'X-HgArg') args.update(urlreq.parseqs(argvalue, keep_blank_values=True)) return args def forwardpayload(self, fp): if r'HTTP_CONTENT_LENGTH' in self._req.env: length = int(self._req.env[r'HTTP_CONTENT_LENGTH']) else: length = int(self._req.env[r'CONTENT_LENGTH']) # If httppostargs is used, we need to read Content-Length # minus the amount that was consumed by args. length -= int(self._req.env.get(r'HTTP_X_HGARGS_POST', 0)) for s in util.filechunkiter(self._req, limit=length): fp.write(s) @contextlib.contextmanager def mayberedirectstdio(self): oldout = self._ui.fout olderr = self._ui.ferr out = util.stringio() try: self._ui.fout = out self._ui.ferr = out yield out finally: self._ui.fout = oldout self._ui.ferr = olderr def client(self): return 'remote:%s:%s:%s' % ( self._req.env.get('wsgi.url_scheme') or 'http', urlreq.quote(self._req.env.get('REMOTE_HOST', '')), urlreq.quote(self._req.env.get('REMOTE_USER', ''))) # This method exists mostly so that extensions like remotefilelog can # disable a kludgey legacy method only over http. As of early 2018, # there are no other known users, so with any luck we can discard this # hook if remotefilelog becomes a first-party extension. def iscmd(cmd): return cmd in wireproto.commands def parsehttprequest(repo, req, query): """Parse the HTTP request for a wire protocol request. If the current request appears to be a wire protocol request, this function returns a dict with details about that request, including an ``abstractprotocolserver`` instance suitable for handling the request. Otherwise, ``None`` is returned. ``req`` is a ``wsgirequest`` instance. """ # HTTP version 1 wire protocol requests are denoted by a "cmd" query # string parameter. If it isn't present, this isn't a wire protocol # request. if r'cmd' not in req.form: return None cmd = pycompat.sysbytes(req.form[r'cmd'][0]) # The "cmd" request parameter is used by both the wire protocol and hgweb. # While not all wire protocol commands are available for all transports, # if we see a "cmd" value that resembles a known wire protocol command, we # route it to a protocol handler. This is better than routing possible # wire protocol requests to hgweb because it prevents hgweb from using # known wire protocol commands and it is less confusing for machine # clients. if not iscmd(cmd): return None proto = httpv1protocolhandler(req, repo.ui) return { 'cmd': cmd, 'proto': proto, 'dispatch': lambda: _callhttp(repo, req, proto, cmd), 'handleerror': lambda ex: _handlehttperror(ex, req, cmd), } def _httpresponsetype(ui, req, prefer_uncompressed): """Determine the appropriate response type and compression settings. Returns a tuple of (mediatype, compengine, engineopts). """ # Determine the response media type and compression engine based # on the request parameters. protocaps = decodevaluefromheaders(req, r'X-HgProto').split(' ') if '0.2' in protocaps: # All clients are expected to support uncompressed data. if prefer_uncompressed: return HGTYPE2, util._noopengine(), {} # Default as defined by wire protocol spec. compformats = ['zlib', 'none'] for cap in protocaps: if cap.startswith('comp='): compformats = cap[5:].split(',') break # Now find an agreed upon compression format. for engine in wireproto.supportedcompengines(ui, util.SERVERROLE): if engine.wireprotosupport().name in compformats: opts = {} level = ui.configint('server', '%slevel' % engine.name()) if level is not None: opts['level'] = level return HGTYPE2, engine, opts # No mutually supported compression format. Fall back to the # legacy protocol. # Don't allow untrusted settings because disabling compression or # setting a very high compression level could lead to flooding # the server's network or CPU. opts = {'level': ui.configint('server', 'zliblevel')} return HGTYPE, util.compengines['zlib'], opts def _callhttp(repo, req, proto, cmd): def genversion2(gen, engine, engineopts): # application/mercurial-0.2 always sends a payload header # identifying the compression engine. name = engine.wireprotosupport().name assert 0 < len(name) < 256 yield struct.pack('B', len(name)) yield name for chunk in gen: yield chunk rsp = wireproto.dispatch(repo, proto, cmd) if not wireproto.commands.commandavailable(cmd, proto): req.respond(HTTP_OK, HGERRTYPE, body=_('requested wire protocol command is not available ' 'over HTTP')) return [] if isinstance(rsp, bytes): req.respond(HTTP_OK, HGTYPE, body=rsp) return [] elif isinstance(rsp, wireprototypes.bytesresponse): req.respond(HTTP_OK, HGTYPE, body=rsp.data) return [] elif isinstance(rsp, wireprototypes.streamreslegacy): gen = rsp.gen req.respond(HTTP_OK, HGTYPE) return gen elif isinstance(rsp, wireprototypes.streamres): gen = rsp.gen # This code for compression should not be streamres specific. It # is here because we only compress streamres at the moment. mediatype, engine, engineopts = _httpresponsetype( repo.ui, req, rsp.prefer_uncompressed) gen = engine.compressstream(gen, engineopts) if mediatype == HGTYPE2: gen = genversion2(gen, engine, engineopts) req.respond(HTTP_OK, mediatype) return gen elif isinstance(rsp, wireprototypes.pushres): rsp = '%d\n%s' % (rsp.res, rsp.output) req.respond(HTTP_OK, HGTYPE, body=rsp) return [] elif isinstance(rsp, wireprototypes.pusherr): # This is the httplib workaround documented in _handlehttperror(). req.drain() rsp = '0\n%s\n' % rsp.res req.respond(HTTP_OK, HGTYPE, body=rsp) return [] elif isinstance(rsp, wireprototypes.ooberror): rsp = rsp.message req.respond(HTTP_OK, HGERRTYPE, body=rsp) return [] raise error.ProgrammingError('hgweb.protocol internal failure', rsp) def _handlehttperror(e, req, cmd): """Called when an ErrorResponse is raised during HTTP request processing.""" # Clients using Python's httplib are stateful: the HTTP client # won't process an HTTP response until all request data is # sent to the server. The intent of this code is to ensure # we always read HTTP request data from the client, thus # ensuring httplib transitions to a state that allows it to read # the HTTP response. In other words, it helps prevent deadlocks # on clients using httplib. if (req.env[r'REQUEST_METHOD'] == r'POST' and # But not if Expect: 100-continue is being used. (req.env.get('HTTP_EXPECT', '').lower() != '100-continue') or # Or the non-httplib HTTP library is being advertised by # the client. req.env.get('X-HgHttp2', '')): req.drain() else: req.headers.append((r'Connection', r'Close')) # TODO This response body assumes the failed command was # "unbundle." That assumption is not always valid. req.respond(e, HGTYPE, body='0\n%s\n' % pycompat.bytestr(e)) return '' def _sshv1respondbytes(fout, value): """Send a bytes response for protocol version 1.""" fout.write('%d\n' % len(value)) fout.write(value) fout.flush() def _sshv1respondstream(fout, source): write = fout.write for chunk in source.gen: write(chunk) fout.flush() def _sshv1respondooberror(fout, ferr, rsp): ferr.write(b'%s\n-\n' % rsp) ferr.flush() fout.write(b'\n') fout.flush() class sshv1protocolhandler(baseprotocolhandler): """Handler for requests services via version 1 of SSH protocol.""" def __init__(self, ui, fin, fout): self._ui = ui self._fin = fin self._fout = fout @property def name(self): return SSHV1 def getargs(self, args): data = {} keys = args.split() for n in xrange(len(keys)): argline = self._fin.readline()[:-1] arg, l = argline.split() if arg not in keys: raise error.Abort(_("unexpected parameter %r") % arg) if arg == '*': star = {} for k in xrange(int(l)): argline = self._fin.readline()[:-1] arg, l = argline.split() val = self._fin.read(int(l)) star[arg] = val data['*'] = star else: val = self._fin.read(int(l)) data[arg] = val return [data[k] for k in keys] def forwardpayload(self, fpout): # The file is in the form: # # <chunk size>\n<chunk> # ... # 0\n _sshv1respondbytes(self._fout, b'') count = int(self._fin.readline()) while count: fpout.write(self._fin.read(count)) count = int(self._fin.readline()) @contextlib.contextmanager def mayberedirectstdio(self): yield None def client(self): client = encoding.environ.get('SSH_CLIENT', '').split(' ', 1)[0] return 'remote:ssh:' + client class sshv2protocolhandler(sshv1protocolhandler): """Protocol handler for version 2 of the SSH protocol.""" def _runsshserver(ui, repo, fin, fout): # This function operates like a state machine of sorts. The following # states are defined: # # protov1-serving # Server is in protocol version 1 serving mode. Commands arrive on # new lines. These commands are processed in this state, one command # after the other. # # protov2-serving # Server is in protocol version 2 serving mode. # # upgrade-initial # The server is going to process an upgrade request. # # upgrade-v2-filter-legacy-handshake # The protocol is being upgraded to version 2. The server is expecting # the legacy handshake from version 1. # # upgrade-v2-finish # The upgrade to version 2 of the protocol is imminent. # # shutdown # The server is shutting down, possibly in reaction to a client event. # # And here are their transitions: # # protov1-serving -> shutdown # When server receives an empty request or encounters another # error. # # protov1-serving -> upgrade-initial # An upgrade request line was seen. # # upgrade-initial -> upgrade-v2-filter-legacy-handshake # Upgrade to version 2 in progress. Server is expecting to # process a legacy handshake. # # upgrade-v2-filter-legacy-handshake -> shutdown # Client did not fulfill upgrade handshake requirements. # # upgrade-v2-filter-legacy-handshake -> upgrade-v2-finish # Client fulfilled version 2 upgrade requirements. Finishing that # upgrade. # # upgrade-v2-finish -> protov2-serving # Protocol upgrade to version 2 complete. Server can now speak protocol # version 2. # # protov2-serving -> protov1-serving # Ths happens by default since protocol version 2 is the same as # version 1 except for the handshake. state = 'protov1-serving' proto = sshv1protocolhandler(ui, fin, fout) protoswitched = False while True: if state == 'protov1-serving': # Commands are issued on new lines. request = fin.readline()[:-1] # Empty lines signal to terminate the connection. if not request: state = 'shutdown' continue # It looks like a protocol upgrade request. Transition state to # handle it. if request.startswith(b'upgrade '): if protoswitched: _sshv1respondooberror(fout, ui.ferr, b'cannot upgrade protocols multiple ' b'times') state = 'shutdown' continue state = 'upgrade-initial' continue available = wireproto.commands.commandavailable(request, proto) # This command isn't available. Send an empty response and go # back to waiting for a new command. if not available: _sshv1respondbytes(fout, b'') continue rsp = wireproto.dispatch(repo, proto, request) if isinstance(rsp, bytes): _sshv1respondbytes(fout, rsp) elif isinstance(rsp, wireprototypes.bytesresponse): _sshv1respondbytes(fout, rsp.data) elif isinstance(rsp, wireprototypes.streamres): _sshv1respondstream(fout, rsp) elif isinstance(rsp, wireprototypes.streamreslegacy): _sshv1respondstream(fout, rsp) elif isinstance(rsp, wireprototypes.pushres): _sshv1respondbytes(fout, b'') _sshv1respondbytes(fout, b'%d' % rsp.res) elif isinstance(rsp, wireprototypes.pusherr): _sshv1respondbytes(fout, rsp.res) elif isinstance(rsp, wireprototypes.ooberror): _sshv1respondooberror(fout, ui.ferr, rsp.message) else: raise error.ProgrammingError('unhandled response type from ' 'wire protocol command: %s' % rsp) # For now, protocol version 2 serving just goes back to version 1. elif state == 'protov2-serving': state = 'protov1-serving' continue elif state == 'upgrade-initial': # We should never transition into this state if we've switched # protocols. assert not protoswitched assert proto.name == SSHV1 # Expected: upgrade <token> <capabilities> # If we get something else, the request is malformed. It could be # from a future client that has altered the upgrade line content. # We treat this as an unknown command. try: token, caps = request.split(b' ')[1:] except ValueError: _sshv1respondbytes(fout, b'') state = 'protov1-serving' continue # Send empty response if we don't support upgrading protocols. if not ui.configbool('experimental', 'sshserver.support-v2'): _sshv1respondbytes(fout, b'') state = 'protov1-serving' continue try: caps = urlreq.parseqs(caps) except ValueError: _sshv1respondbytes(fout, b'') state = 'protov1-serving' continue # We don't see an upgrade request to protocol version 2. Ignore # the upgrade request. wantedprotos = caps.get(b'proto', [b''])[0] if SSHV2 not in wantedprotos: _sshv1respondbytes(fout, b'') state = 'protov1-serving' continue # It looks like we can honor this upgrade request to protocol 2. # Filter the rest of the handshake protocol request lines. state = 'upgrade-v2-filter-legacy-handshake' continue elif state == 'upgrade-v2-filter-legacy-handshake': # Client should have sent legacy handshake after an ``upgrade`` # request. Expected lines: # # hello # between # pairs 81 # 0000...-0000... ok = True for line in (b'hello', b'between', b'pairs 81'): request = fin.readline()[:-1] if request != line: _sshv1respondooberror(fout, ui.ferr, b'malformed handshake protocol: ' b'missing %s' % line) ok = False state = 'shutdown' break if not ok: continue request = fin.read(81) if request != b'%s-%s' % (b'0' * 40, b'0' * 40): _sshv1respondooberror(fout, ui.ferr, b'malformed handshake protocol: ' b'missing between argument value') state = 'shutdown' continue state = 'upgrade-v2-finish' continue elif state == 'upgrade-v2-finish': # Send the upgrade response. fout.write(b'upgraded %s %s\n' % (token, SSHV2)) servercaps = wireproto.capabilities(repo, proto) rsp = b'capabilities: %s' % servercaps.data fout.write(b'%d\n%s\n' % (len(rsp), rsp)) fout.flush() proto = sshv2protocolhandler(ui, fin, fout) protoswitched = True state = 'protov2-serving' continue elif state == 'shutdown': break else: raise error.ProgrammingError('unhandled ssh server state: %s' % state) class sshserver(object): def __init__(self, ui, repo): self._ui = ui self._repo = repo self._fin = ui.fin self._fout = ui.fout hook.redirect(True) ui.fout = repo.ui.fout = ui.ferr # Prevent insertion/deletion of CRs util.setbinary(self._fin) util.setbinary(self._fout) def serve_forever(self): _runsshserver(self._ui, self._repo, self._fin, self._fout) sys.exit(0)