Mercurial > hg
view mercurial/wireprotoserver.py @ 50757:19108906abaf stable
extensions: imp module is removed in Python 3.12 - use importlib to load files
imp has been deprecated for a long time, and has finally been removed in Python
3.12 .
imp was only used for loading extensions that has been specified with direct
.py path or path to a package directory. The same use cases can be achieved
quite simple with importlib, , possiby with small changes in corner cases with
undefined behaviour, such as extensions without .py source.
There might also be corner cases and undefined behaviour around use of
sys.modules and reloading.
author | Mads Kiilerich <mads@kiilerich.com> |
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date | Wed, 28 Jun 2023 14:23:13 +0200 |
parents | 45c7bada5200 |
children | 13c004b54cbe |
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# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # Copyright 2005-2007 Olivia Mackall <olivia@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. import contextlib import struct import threading from .i18n import _ from . import ( encoding, error, pycompat, util, wireprototypes, wireprotov1server, ) from .interfaces import util as interfaceutil from .utils import ( compression, stringutil, ) stringio = util.stringio urlerr = util.urlerr urlreq = util.urlreq HTTP_OK = 200 HGTYPE = b'application/mercurial-0.1' HGTYPE2 = b'application/mercurial-0.2' HGERRTYPE = b'application/hg-error' SSHV1 = wireprototypes.SSHV1 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 while True: v = req.headers.get(b'%s-%d' % (headerprefix, i)) if v is None: break chunks.append(pycompat.bytesurl(v)) i += 1 return b''.join(chunks) @interfaceutil.implementer(wireprototypes.baseprotocolhandler) class httpv1protocolhandler: def __init__(self, req, ui, checkperm): self._req = req self._ui = ui self._checkperm = checkperm self._protocaps = None @property def name(self): return b'http-v1' def getargs(self, args): knownargs = self._args() data = {} keys = args.split() for k in keys: if k == b'*': star = {} for key in knownargs.keys(): if key != b'cmd' and key not in keys: star[key] = knownargs[key][0] data[b'*'] = star else: data[k] = knownargs[k][0] return [data[k] for k in keys] def _args(self): args = self._req.qsparams.asdictoflists() postlen = int(self._req.headers.get(b'X-HgArgs-Post', 0)) if postlen: args.update( urlreq.parseqs( self._req.bodyfh.read(postlen), keep_blank_values=True ) ) return args argvalue = decodevaluefromheaders(self._req, b'X-HgArg') args.update(urlreq.parseqs(argvalue, keep_blank_values=True)) return args def getprotocaps(self): if self._protocaps is None: value = decodevaluefromheaders(self._req, b'X-HgProto') self._protocaps = set(value.split(b' ')) return self._protocaps def getpayload(self): # Existing clients *always* send Content-Length. length = int(self._req.headers[b'Content-Length']) # If httppostargs is used, we need to read Content-Length # minus the amount that was consumed by args. length -= int(self._req.headers.get(b'X-HgArgs-Post', 0)) return util.filechunkiter(self._req.bodyfh, limit=length) @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 b'remote:%s:%s:%s' % ( self._req.urlscheme, urlreq.quote(self._req.remotehost or b''), urlreq.quote(self._req.remoteuser or b''), ) def addcapabilities(self, repo, caps): caps.append(b'batch') caps.append( b'httpheader=%d' % repo.ui.configint(b'server', b'maxhttpheaderlen') ) if repo.ui.configbool(b'experimental', b'httppostargs'): caps.append(b'httppostargs') # FUTURE advertise 0.2rx once support is implemented # FUTURE advertise minrx and mintx after consulting config option caps.append(b'httpmediatype=0.1rx,0.1tx,0.2tx') compengines = wireprototypes.supportedcompengines( repo.ui, compression.SERVERROLE ) if compengines: comptypes = b','.join( urlreq.quote(e.wireprotosupport().name) for e in compengines ) caps.append(b'compression=%s' % comptypes) return caps def checkperm(self, perm): return self._checkperm(perm) # 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 wireprotov1server.commands def handlewsgirequest(rctx, req, res, checkperm): """Possibly process a wire protocol request. If the current request is a wire protocol request, the request is processed by this function. ``req`` is a ``parsedrequest`` instance. ``res`` is a ``wsgiresponse`` instance. Returns a bool indicating if the request was serviced. If set, the caller should stop processing the request, as a response has already been issued. """ # Avoid cycle involving hg module. from .hgweb import common as hgwebcommon repo = rctx.repo # 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 b'cmd' not in req.qsparams: return False cmd = req.qsparams[b'cmd'] # 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 False # The "cmd" query string argument is only valid on the root path of the # repo. e.g. ``/?cmd=foo``, ``/repo?cmd=foo``. URL paths within the repo # like ``/blah?cmd=foo`` are not allowed. So don't recognize the request # in this case. We send an HTTP 404 for backwards compatibility reasons. if req.dispatchpath: res.status = hgwebcommon.statusmessage(404) res.headers[b'Content-Type'] = HGTYPE # TODO This is not a good response to issue for this request. This # is mostly for BC for now. res.setbodybytes(b'0\n%s\n' % b'Not Found') return True proto = httpv1protocolhandler( req, repo.ui, lambda perm: checkperm(rctx, req, perm) ) # The permissions checker should be the only thing that can raise an # ErrorResponse. It is kind of a layer violation to catch an hgweb # exception here. So consider refactoring into a exception type that # is associated with the wire protocol. try: _callhttp(repo, req, res, proto, cmd) except hgwebcommon.ErrorResponse as e: for k, v in e.headers: res.headers[k] = v res.status = hgwebcommon.statusmessage( e.code, stringutil.forcebytestr(e) ) # TODO This response body assumes the failed command was # "unbundle." That assumption is not always valid. res.setbodybytes(b'0\n%s\n' % stringutil.forcebytestr(e)) return True def _httpresponsetype(ui, proto, 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. if b'0.2' in proto.getprotocaps(): # All clients are expected to support uncompressed data. if prefer_uncompressed: return HGTYPE2, compression._noopengine(), {} # Now find an agreed upon compression format. compformats = wireprotov1server.clientcompressionsupport(proto) for engine in wireprototypes.supportedcompengines( ui, compression.SERVERROLE ): if engine.wireprotosupport().name in compformats: opts = {} level = ui.configint(b'server', b'%slevel' % engine.name()) if level is not None: opts[b'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 = {b'level': ui.configint(b'server', b'zliblevel')} return HGTYPE, util.compengines[b'zlib'], opts def _callhttp(repo, req, res, proto, cmd): # Avoid cycle involving hg module. from .hgweb import common as hgwebcommon 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'B', len(name)) yield name for chunk in gen: yield chunk def setresponse(code, contenttype, bodybytes=None, bodygen=None): if code == HTTP_OK: res.status = b'200 Script output follows' else: res.status = hgwebcommon.statusmessage(code) res.headers[b'Content-Type'] = contenttype if bodybytes is not None: res.setbodybytes(bodybytes) if bodygen is not None: res.setbodygen(bodygen) if not wireprotov1server.commands.commandavailable(cmd, proto): setresponse( HTTP_OK, HGERRTYPE, _( b'requested wire protocol command is not available over ' b'HTTP' ), ) return proto.checkperm(wireprotov1server.commands[cmd].permission) accesshidden = hgwebcommon.hashiddenaccess(repo, req) rsp = wireprotov1server.dispatch(repo, proto, cmd, accesshidden) if isinstance(rsp, bytes): setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.bytesresponse): setresponse(HTTP_OK, HGTYPE, bodybytes=rsp.data) elif isinstance(rsp, wireprototypes.streamreslegacy): setresponse(HTTP_OK, HGTYPE, bodygen=rsp.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, proto, rsp.prefer_uncompressed ) gen = engine.compressstream(gen, engineopts) if mediatype == HGTYPE2: gen = genversion2(gen, engine, engineopts) setresponse(HTTP_OK, mediatype, bodygen=gen) elif isinstance(rsp, wireprototypes.pushres): rsp = b'%d\n%s' % (rsp.res, rsp.output) setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.pusherr): rsp = b'0\n%s\n' % rsp.res res.drain = True setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.ooberror): setresponse(HTTP_OK, HGERRTYPE, bodybytes=rsp.message) else: raise error.ProgrammingError(b'hgweb.protocol internal failure', rsp) def _sshv1respondbytes(fout, value): """Send a bytes response for protocol version 1.""" fout.write(b'%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() @interfaceutil.implementer(wireprototypes.baseprotocolhandler) class sshv1protocolhandler: """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 self._protocaps = set() @property def name(self): return wireprototypes.SSHV1 def getargs(self, args): data = {} keys = args.split() for n in range(len(keys)): argline = self._fin.readline()[:-1] arg, l = argline.split() if arg not in keys: raise error.Abort(_(b"unexpected parameter %r") % arg) if arg == b'*': star = {} for k in range(int(l)): argline = self._fin.readline()[:-1] arg, l = argline.split() val = self._fin.read(int(l)) star[arg] = val data[b'*'] = star else: val = self._fin.read(int(l)) data[arg] = val return [data[k] for k in keys] def getprotocaps(self): return self._protocaps def getpayload(self): # We initially send an empty response. This tells the client it is # OK to start sending data. If a client sees any other response, it # interprets it as an error. _sshv1respondbytes(self._fout, b'') # The file is in the form: # # <chunk size>\n<chunk> # ... # 0\n count = int(self._fin.readline()) while count: yield self._fin.read(count) count = int(self._fin.readline()) @contextlib.contextmanager def mayberedirectstdio(self): yield None def client(self): client = encoding.environ.get(b'SSH_CLIENT', b'').split(b' ', 1)[0] return b'remote:ssh:' + client def addcapabilities(self, repo, caps): if self.name == wireprototypes.SSHV1: caps.append(b'protocaps') caps.append(b'batch') return caps def checkperm(self, perm): pass def _runsshserver(ui, repo, fin, fout, ev, accesshidden=False): # 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. # # 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. state = b'protov1-serving' proto = sshv1protocolhandler(ui, fin, fout) while not ev.is_set(): if state == b'protov1-serving': # Commands are issued on new lines. request = fin.readline()[:-1] # Empty lines signal to terminate the connection. if not request: state = b'shutdown' continue available = wireprotov1server.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 = wireprotov1server.dispatch( repo, proto, request, accesshidden=accesshidden ) repo.ui.fout.flush() repo.ui.ferr.flush() 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( b'unhandled response type from ' b'wire protocol command: %s' % rsp ) elif state == b'shutdown': break else: raise error.ProgrammingError( b'unhandled ssh server state: %s' % state ) class sshserver: def __init__(self, ui, repo, logfh=None, accesshidden=False): self._ui = ui self._repo = repo self._fin, self._fout = ui.protectfinout() self._accesshidden = accesshidden # Log write I/O to stdout and stderr if configured. if logfh: self._fout = util.makeloggingfileobject( logfh, self._fout, b'o', logdata=True ) ui.ferr = util.makeloggingfileobject( logfh, ui.ferr, b'e', logdata=True ) def serve_forever(self): self.serveuntil(threading.Event()) self._ui.restorefinout(self._fin, self._fout) def serveuntil(self, ev): """Serve until a threading.Event is set.""" _runsshserver( self._ui, self._repo, self._fin, self._fout, ev, self._accesshidden )