Mercurial > hg
view mercurial/sshpeer.py @ 25708:d3d32643c060
wireproto: correctly escape batched args and responses (issue4739)
This issue appears to be as old as wireproto batching itself: I can
reproduce the failure as far back as 08ef6b5f3715 trivially by
rebasing the test changes in this patch, which was back in the 1.9
era. I didn't test before that change, because prior to that the
testfile has a different name and I'm lazy.
Note that the test thought it was checking this case, but it actually
wasn't: it put a literal ; in the arg and response for its greet
command, but the mangle/unmangle step defined in the test meant that
instead of "Fo, =;o" going over the wire, "Gp-!><p" went instead,
which doesn't contain any special characters (those being [.=;]) and
thus not exercising the escaping. The test has been updated to use
pre-unmangled special characters, so the request is now "Fo+<:o",
which mangles to "Gp,=;p". I have confirmed that the test fails
without the adjustment to the escaping rules in wireproto.py.
No existing clients of RPC batching were depending on the old behavior
in any way. The only *actual* users of batchable RPCs in core were:
1) largefiles, wherein it batches up many statlfile calls. It sends
hexlified hashes over the wire and gets a 0, 1, or 2 back as a
response. No risk of special characters.
2) setdiscovery, which was using heads() and known(), both of which
communicate via hexlified nodes. Again, no risk of special characters.
Since the escaping functionality has been completely broken since it
was introduced, we know that it has no users. As such, we can change
the escaping mechanism without having to worry about backwards
compatibility issues.
For the curious, this was detected by chance: it happens that the
lz4-compressed text of a test file for remotefilelog compressed to
something containing a ;, which then caused the failure when I moved
remotefilelog to using batching for file content fetching.
author | Augie Fackler <augie@google.com> |
---|---|
date | Tue, 30 Jun 2015 19:19:17 -0400 |
parents | 4642f0b803ae |
children | de7a3893ee65 |
line wrap: on
line source
# sshpeer.py - ssh repository proxy class for mercurial # # Copyright 2005, 2006 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. import re from i18n import _ import util, error, wireproto class remotelock(object): def __init__(self, repo): self.repo = repo def release(self): self.repo.unlock() self.repo = None def __del__(self): if self.repo: self.release() def _serverquote(s): if not s: return s '''quote a string for the remote shell ... which we assume is sh''' if re.match('[a-zA-Z0-9@%_+=:,./-]*$', s): return s return "'%s'" % s.replace("'", "'\\''") def _forwardoutput(ui, pipe): """display all data currently available on pipe as remote output. This is non blocking.""" s = util.readpipe(pipe) if s: for l in s.splitlines(): ui.status(_("remote: "), l, '\n') class doublepipe(object): """Operate a side-channel pipe in addition of a main one The side-channel pipe contains server output to be forwarded to the user input. The double pipe will behave as the "main" pipe, but will ensure the content of the "side" pipe is properly processed while we wait for blocking call on the "main" pipe. If large amounts of data are read from "main", the forward will cease after the first bytes start to appear. This simplifies the implementation without affecting actual output of sshpeer too much as we rarely issue large read for data not yet emitted by the server. The main pipe is expected to be a 'bufferedinputpipe' from the util module that handle all the os specific bites. This class lives in this module because it focus on behavior specifig to the ssh protocol.""" def __init__(self, ui, main, side): self._ui = ui self._main = main self._side = side def _wait(self): """wait until some data are available on main or side return a pair of boolean (ismainready, issideready) (This will only wait for data if the setup is supported by `util.poll`) """ if getattr(self._main, 'hasbuffer', False): # getattr for classic pipe return (True, True) # main has data, assume side is worth poking at. fds = [self._main.fileno(), self._side.fileno()] try: act = util.poll(fds) except NotImplementedError: # non supported yet case, assume all have data. act = fds return (self._main.fileno() in act, self._side.fileno() in act) def write(self, data): return self._call('write', data) def read(self, size): return self._call('read', size) def readline(self): return self._call('readline') def _call(self, methname, data=None): """call <methname> on "main", forward output of "side" while blocking """ # data can be '' or 0 if (data is not None and not data) or self._main.closed: _forwardoutput(self._ui, self._side) return '' while True: mainready, sideready = self._wait() if sideready: _forwardoutput(self._ui, self._side) if mainready: meth = getattr(self._main, methname) if data is None: return meth() else: return meth(data) def close(self): return self._main.close() def flush(self): return self._main.flush() class sshpeer(wireproto.wirepeer): def __init__(self, ui, path, create=False): self._url = path self.ui = ui self.pipeo = self.pipei = self.pipee = None u = util.url(path, parsequery=False, parsefragment=False) if u.scheme != 'ssh' or not u.host or u.path is None: self._abort(error.RepoError(_("couldn't parse location %s") % path)) self.user = u.user if u.passwd is not None: self._abort(error.RepoError(_("password in URL not supported"))) self.host = u.host self.port = u.port self.path = u.path or "." sshcmd = self.ui.config("ui", "ssh", "ssh") remotecmd = self.ui.config("ui", "remotecmd", "hg") args = util.sshargs(sshcmd, _serverquote(self.host), _serverquote(self.user), _serverquote(self.port)) if create: cmd = '%s %s %s' % (sshcmd, args, util.shellquote("%s init %s" % (_serverquote(remotecmd), _serverquote(self.path)))) ui.debug('running %s\n' % cmd) res = ui.system(cmd) if res != 0: self._abort(error.RepoError(_("could not create remote repo"))) self._validaterepo(sshcmd, args, remotecmd) def url(self): return self._url def _validaterepo(self, sshcmd, args, remotecmd): # cleanup up previous run self.cleanup() cmd = '%s %s %s' % (sshcmd, args, util.shellquote("%s -R %s serve --stdio" % (_serverquote(remotecmd), _serverquote(self.path)))) self.ui.debug('running %s\n' % cmd) cmd = util.quotecommand(cmd) # while self.subprocess isn't used, having it allows the subprocess to # to clean up correctly later # # no buffer allow the use of 'select' # feel free to remove buffering and select usage when we ultimately # move to threading. sub = util.popen4(cmd, bufsize=0) self.pipeo, self.pipei, self.pipee, self.subprocess = sub self.pipei = util.bufferedinputpipe(self.pipei) self.pipei = doublepipe(self.ui, self.pipei, self.pipee) self.pipeo = doublepipe(self.ui, self.pipeo, self.pipee) # skip any noise generated by remote shell self._callstream("hello") r = self._callstream("between", pairs=("%s-%s" % ("0"*40, "0"*40))) lines = ["", "dummy"] max_noise = 500 while lines[-1] and max_noise: l = r.readline() self.readerr() if lines[-1] == "1\n" and l == "\n": break if l: self.ui.debug("remote: ", l) lines.append(l) max_noise -= 1 else: self._abort(error.RepoError(_('no suitable response from ' 'remote hg'))) self._caps = set() for l in reversed(lines): if l.startswith("capabilities:"): self._caps.update(l[:-1].split(":")[1].split()) break def _capabilities(self): return self._caps def readerr(self): _forwardoutput(self.ui, self.pipee) def _abort(self, exception): self.cleanup() raise exception def cleanup(self): if self.pipeo is None: return self.pipeo.close() self.pipei.close() try: # read the error descriptor until EOF for l in self.pipee: self.ui.status(_("remote: "), l) except (IOError, ValueError): pass self.pipee.close() __del__ = cleanup def _callstream(self, cmd, **args): self.ui.debug("sending %s command\n" % cmd) self.pipeo.write("%s\n" % cmd) _func, names = wireproto.commands[cmd] keys = names.split() wireargs = {} for k in keys: if k == '*': wireargs['*'] = args break else: wireargs[k] = args[k] del args[k] for k, v in sorted(wireargs.iteritems()): self.pipeo.write("%s %d\n" % (k, len(v))) if isinstance(v, dict): for dk, dv in v.iteritems(): self.pipeo.write("%s %d\n" % (dk, len(dv))) self.pipeo.write(dv) else: self.pipeo.write(v) self.pipeo.flush() return self.pipei def _callcompressable(self, cmd, **args): return self._callstream(cmd, **args) def _call(self, cmd, **args): self._callstream(cmd, **args) return self._recv() def _callpush(self, cmd, fp, **args): r = self._call(cmd, **args) if r: return '', r while True: d = fp.read(4096) if not d: break self._send(d) self._send("", flush=True) r = self._recv() if r: return '', r return self._recv(), '' def _calltwowaystream(self, cmd, fp, **args): r = self._call(cmd, **args) if r: # XXX needs to be made better raise util.Abort('unexpected remote reply: %s' % r) while True: d = fp.read(4096) if not d: break self._send(d) self._send("", flush=True) return self.pipei def _recv(self): l = self.pipei.readline() if l == '\n': self.readerr() msg = _('check previous remote output') self._abort(error.OutOfBandError(hint=msg)) self.readerr() try: l = int(l) except ValueError: self._abort(error.ResponseError(_("unexpected response:"), l)) return self.pipei.read(l) def _send(self, data, flush=False): self.pipeo.write("%d\n" % len(data)) if data: self.pipeo.write(data) if flush: self.pipeo.flush() self.readerr() def lock(self): self._call("lock") return remotelock(self) def unlock(self): self._call("unlock") def addchangegroup(self, cg, source, url, lock=None): '''Send a changegroup to the remote server. Return an integer similar to unbundle(). DEPRECATED, since it requires locking the remote.''' d = self._call("addchangegroup") if d: self._abort(error.RepoError(_("push refused: %s") % d)) while True: d = cg.read(4096) if not d: break self.pipeo.write(d) self.readerr() self.pipeo.flush() self.readerr() r = self._recv() if not r: return 1 try: return int(r) except ValueError: self._abort(error.ResponseError(_("unexpected response:"), r)) instance = sshpeer