Mercurial > hg
view contrib/hg-ssh @ 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 | 2b9cda9040f7 |
children | f68ded00cae5 |
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#!/usr/bin/env python # # Copyright 2005-2007 by Intevation GmbH <intevation@intevation.de> # # Author(s): # Thomas Arendsen Hein <thomas@intevation.de> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """ hg-ssh - a wrapper for ssh access to a limited set of mercurial repos To be used in ~/.ssh/authorized_keys with the "command" option, see sshd(8): command="hg-ssh path/to/repo1 /path/to/repo2 ~/repo3 ~user/repo4" ssh-dss ... (probably together with these other useful options: no-port-forwarding,no-X11-forwarding,no-agent-forwarding) This allows pull/push over ssh from/to the repositories given as arguments. If all your repositories are subdirectories of a common directory, you can allow shorter paths with: command="cd path/to/my/repositories && hg-ssh repo1 subdir/repo2" You can use pattern matching of your normal shell, e.g.: command="cd repos && hg-ssh user/thomas/* projects/{mercurial,foo}" You can also add a --read-only flag to allow read-only access to a key, e.g.: command="hg-ssh --read-only repos/*" """ # enable importing on demand to reduce startup time from mercurial import demandimport; demandimport.enable() from mercurial import dispatch import sys, os, shlex def main(): cwd = os.getcwd() readonly = False args = sys.argv[1:] while len(args): if args[0] == '--read-only': readonly = True args.pop(0) else: break allowed_paths = [os.path.normpath(os.path.join(cwd, os.path.expanduser(path))) for path in args] orig_cmd = os.getenv('SSH_ORIGINAL_COMMAND', '?') try: cmdargv = shlex.split(orig_cmd) except ValueError, e: sys.stderr.write('Illegal command "%s": %s\n' % (orig_cmd, e)) sys.exit(255) if cmdargv[:2] == ['hg', '-R'] and cmdargv[3:] == ['serve', '--stdio']: path = cmdargv[2] repo = os.path.normpath(os.path.join(cwd, os.path.expanduser(path))) if repo in allowed_paths: cmd = ['-R', repo, 'serve', '--stdio'] if readonly: cmd += [ '--config', 'hooks.pretxnopen.hg-ssh=python:__main__.rejectpush', '--config', 'hooks.prepushkey.hg-ssh=python:__main__.rejectpush' ] dispatch.dispatch(dispatch.request(cmd)) else: sys.stderr.write('Illegal repository "%s"\n' % repo) sys.exit(255) else: sys.stderr.write('Illegal command "%s"\n' % orig_cmd) sys.exit(255) def rejectpush(ui, **kwargs): ui.warn("Permission denied\n") # mercurial hooks use unix process conventions for hook return values # so a truthy return means failure return True if __name__ == '__main__': main()