rust-index: return an error on a bad index header
This is more idiomatic and allows us to better handle the problem later.
# 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.
from __future__ import annotations
import contextlib
import struct
import threading
from .i18n import _
from . import (
encoding,
error,
pycompat,
util,
wireprototypes,
wireprotov1server,
)
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)
class httpv1protocolhandler(wireprototypes.baseprotocolhandler):
def __init__(self, req, ui, checkperm):
self._req = req
self._ui = ui
self._checkperm = checkperm
self._protocaps = None
@property
def name(self) -> bytes:
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()
class sshv1protocolhandler(wireprototypes.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
self._protocaps = set()
@property
def name(self) -> bytes:
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._accesshidden = accesshidden
self._logfh = logfh
def serve_forever(self):
self.serveuntil(threading.Event())
def serveuntil(self, ev):
"""Serve until a threading.Event is set."""
with self._ui.protectedfinout() as (fin, fout):
if self._logfh:
# Log write I/O to stdout and stderr if configured.
fout = util.makeloggingfileobject(
self._logfh,
fout,
b'o',
logdata=True,
)
self._ui.ferr = util.makeloggingfileobject(
self._logfh,
self._ui.ferr,
b'e',
logdata=True,
)
_runsshserver(
self._ui,
self._repo,
fin,
fout,
ev,
self._accesshidden,
)