Mercurial > hg
view mercurial/hook.py @ 37047:fddcb51b5084
wireproto: define permissions-based routing of HTTPv2 wire protocol
Now that we have a scaffolding for serving version 2 of the HTTP
protocol, let's start implementing it.
A good place to start is URL routing and basic request processing
semantics. We can focus on content types, capabilities detect, etc
later.
Version 2 of the HTTP wire protocol encodes the needed permissions
of the request in the URL path. The reasons for this are documented
in the added documentation. In short, a) it makes it really easy and
fail proof for server administrators to implement path-based
authentication and b) it will enable clients to realize very early in
a server exchange that authentication will be required to complete
the operation. This latter point avoids all kinds of complexity and
problems, like dealing with Expect: 100-continue and clients finding
out later during `hg push` that they need to provide authentication.
This will avoid the current badness where clients send a full bundle,
get an HTTP 403, provide authentication, then retransmit the bundle.
In order to implement command checking, we needed to implement a
protocol handler for the new wire protocol. Our handler is just
small enough to run the code we've implemented.
Tests for the defined functionality have been added.
I very much want to refactor the permissions checking code and define
a better response format. But this can be done later. Nothing is
covered by backwards compatibility at this point.
Differential Revision: https://phab.mercurial-scm.org/D2836
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 19 Mar 2018 16:43:47 -0700 |
parents | 9c636ec1ef37 |
children | d4a2e0d5d042 |
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# hook.py - hook support for mercurial # # Copyright 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 os import sys from .i18n import _ from . import ( demandimport, encoding, error, extensions, pycompat, util, ) def _pythonhook(ui, repo, htype, hname, funcname, args, throw): '''call python hook. hook is callable object, looked up as name in python module. if callable returns "true", hook fails, else passes. if hook raises exception, treated as hook failure. exception propagates if throw is "true". reason for "true" meaning "hook failed" is so that unmodified commands (e.g. mercurial.commands.update) can be run as hooks without wrappers to convert return values.''' if callable(funcname): obj = funcname funcname = pycompat.sysbytes(obj.__module__ + r"." + obj.__name__) else: d = funcname.rfind('.') if d == -1: raise error.HookLoadError( _('%s hook is invalid: "%s" not in a module') % (hname, funcname)) modname = funcname[:d] oldpaths = sys.path if util.mainfrozen(): # binary installs require sys.path manipulation modpath, modfile = os.path.split(modname) if modpath and modfile: sys.path = sys.path[:] + [modpath] modname = modfile with demandimport.deactivated(): try: obj = __import__(pycompat.sysstr(modname)) except (ImportError, SyntaxError): e1 = sys.exc_info() try: # extensions are loaded with hgext_ prefix obj = __import__(r"hgext_%s" % pycompat.sysstr(modname)) except (ImportError, SyntaxError): e2 = sys.exc_info() if ui.tracebackflag: ui.warn(_('exception from first failed import ' 'attempt:\n')) ui.traceback(e1) if ui.tracebackflag: ui.warn(_('exception from second failed import ' 'attempt:\n')) ui.traceback(e2) if not ui.tracebackflag: tracebackhint = _( 'run with --traceback for stack trace') else: tracebackhint = None raise error.HookLoadError( _('%s hook is invalid: import of "%s" failed') % (hname, modname), hint=tracebackhint) sys.path = oldpaths try: for p in funcname.split('.')[1:]: obj = getattr(obj, p) except AttributeError: raise error.HookLoadError( _('%s hook is invalid: "%s" is not defined') % (hname, funcname)) if not callable(obj): raise error.HookLoadError( _('%s hook is invalid: "%s" is not callable') % (hname, funcname)) ui.note(_("calling hook %s: %s\n") % (hname, funcname)) starttime = util.timer() try: r = obj(ui=ui, repo=repo, hooktype=htype, **pycompat.strkwargs(args)) except Exception as exc: if isinstance(exc, error.Abort): ui.warn(_('error: %s hook failed: %s\n') % (hname, exc.args[0])) else: ui.warn(_('error: %s hook raised an exception: ' '%s\n') % (hname, encoding.strtolocal(str(exc)))) if throw: raise if not ui.tracebackflag: ui.warn(_('(run with --traceback for stack trace)\n')) ui.traceback() return True, True finally: duration = util.timer() - starttime ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n', htype, funcname, duration) if r: if throw: raise error.HookAbort(_('%s hook failed') % hname) ui.warn(_('warning: %s hook failed\n') % hname) return r, False def _exthook(ui, repo, htype, name, cmd, args, throw): ui.note(_("running hook %s: %s\n") % (name, cmd)) starttime = util.timer() env = {} # make in-memory changes visible to external process if repo is not None: tr = repo.currenttransaction() repo.dirstate.write(tr) if tr and tr.writepending(): env['HG_PENDING'] = repo.root env['HG_HOOKTYPE'] = htype env['HG_HOOKNAME'] = name for k, v in args.iteritems(): if callable(v): v = v() if isinstance(v, dict): # make the dictionary element order stable across Python # implementations v = ('{' + ', '.join('%r: %r' % i for i in sorted(v.iteritems())) + '}') env['HG_' + k.upper()] = v if repo: cwd = repo.root else: cwd = pycompat.getcwd() r = ui.system(cmd, environ=env, cwd=cwd, blockedtag='exthook-%s' % (name,)) duration = util.timer() - starttime ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n', name, cmd, duration) if r: desc, r = util.explainexit(r) if throw: raise error.HookAbort(_('%s hook %s') % (name, desc)) ui.warn(_('warning: %s hook %s\n') % (name, desc)) return r # represent an untrusted hook command _fromuntrusted = object() def _allhooks(ui): """return a list of (hook-id, cmd) pairs sorted by priority""" hooks = _hookitems(ui) # Be careful in this section, propagating the real commands from untrusted # sources would create a security vulnerability, make sure anything altered # in that section uses "_fromuntrusted" as its command. untrustedhooks = _hookitems(ui, _untrusted=True) for name, value in untrustedhooks.items(): trustedvalue = hooks.get(name, (None, None, name, _fromuntrusted)) if value != trustedvalue: (lp, lo, lk, lv) = trustedvalue hooks[name] = (lp, lo, lk, _fromuntrusted) # (end of the security sensitive section) return [(k, v) for p, o, k, v in sorted(hooks.values())] def _hookitems(ui, _untrusted=False): """return all hooks items ready to be sorted""" hooks = {} for name, cmd in ui.configitems('hooks', untrusted=_untrusted): if not name.startswith('priority'): priority = ui.configint('hooks', 'priority.%s' % name, 0) hooks[name] = (-priority, len(hooks), name, cmd) return hooks _redirect = False def redirect(state): global _redirect _redirect = state def hashook(ui, htype): """return True if a hook is configured for 'htype'""" if not ui.callhooks: return False for hname, cmd in _allhooks(ui): if hname.split('.')[0] == htype and cmd: return True return False def hook(ui, repo, htype, throw=False, **args): if not ui.callhooks: return False hooks = [] for hname, cmd in _allhooks(ui): if hname.split('.')[0] == htype and cmd: hooks.append((hname, cmd)) res = runhooks(ui, repo, htype, hooks, throw=throw, **args) r = False for hname, cmd in hooks: r = res[hname][0] or r return r def runhooks(ui, repo, htype, hooks, throw=False, **args): args = pycompat.byteskwargs(args) res = {} oldstdout = -1 try: for hname, cmd in hooks: if oldstdout == -1 and _redirect: try: stdoutno = util.stdout.fileno() stderrno = util.stderr.fileno() # temporarily redirect stdout to stderr, if possible if stdoutno >= 0 and stderrno >= 0: util.stdout.flush() oldstdout = os.dup(stdoutno) os.dup2(stderrno, stdoutno) except (OSError, AttributeError): # files seem to be bogus, give up on redirecting (WSGI, etc) pass if cmd is _fromuntrusted: if throw: raise error.HookAbort( _('untrusted hook %s not executed') % hname, hint = _("see 'hg help config.trusted'")) ui.warn(_('warning: untrusted hook %s not executed\n') % hname) r = 1 raised = False elif callable(cmd): r, raised = _pythonhook(ui, repo, htype, hname, cmd, args, throw) elif cmd.startswith('python:'): if cmd.count(':') >= 2: path, cmd = cmd[7:].rsplit(':', 1) path = util.expandpath(path) if repo: path = os.path.join(repo.root, path) try: mod = extensions.loadpath(path, 'hghook.%s' % hname) except Exception: ui.write(_("loading %s hook failed:\n") % hname) raise hookfn = getattr(mod, cmd) else: hookfn = cmd[7:].strip() r, raised = _pythonhook(ui, repo, htype, hname, hookfn, args, throw) else: r = _exthook(ui, repo, htype, hname, cmd, args, throw) raised = False res[hname] = r, raised finally: # The stderr is fully buffered on Windows when connected to a pipe. # A forcible flush is required to make small stderr data in the # remote side available to the client immediately. util.stderr.flush() if _redirect and oldstdout >= 0: util.stdout.flush() # write hook output to stderr fd os.dup2(oldstdout, stdoutno) os.close(oldstdout) return res