view mercurial/formatter.py @ 26120:1a45e49a6bed stable 3.5.1

hgweb: fix trust of templates path (BC)

Long ago we disabled trust of the templates path with a comment
describing the (insecure) behavior before the change. At some later
refactor, the code was apparently changed back to match the comment,
unaware that the intent of the comment was to describe the behavior to
avoid.

This change disables the trust and updates the comment to explicitly
say not only what the old problem was, but also that it was in fact a
problem and the action taken to prevent it.

Impact: prior to this change, if you had a UNIX-based hgweb server
where users can write hgrc files, those users could potentially read
any file readable by the web server.

This is marked as a backwards compatibility issue because people may
have configured templates without proper trust settings. Issue spotted
by Greg Szorc.

# formatter.py - generic output formatting for mercurial
#
# Copyright 2012 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import cPickle
from node import hex, short
from i18n import _
import encoding, util
import templater
import os

class baseformatter(object):
    def __init__(self, ui, topic, opts):
        self._ui = ui
        self._topic = topic
        self._style = opts.get("style")
        self._template = opts.get("template")
        self._item = None
        # function to convert node to string suitable for this output
        self.hexfunc = hex
    def __nonzero__(self):
        '''return False if we're not doing real templating so we can
        skip extra work'''
        return True
    def _showitem(self):
        '''show a formatted item once all data is collected'''
        pass
    def startitem(self):
        '''begin an item in the format list'''
        if self._item is not None:
            self._showitem()
        self._item = {}
    def data(self, **data):
        '''insert data into item that's not shown in default output'''
        self._item.update(data)
    def write(self, fields, deftext, *fielddata, **opts):
        '''do default text output while assigning data to item'''
        for k, v in zip(fields.split(), fielddata):
            self._item[k] = v
    def condwrite(self, cond, fields, deftext, *fielddata, **opts):
        '''do conditional write (primarily for plain formatter)'''
        for k, v in zip(fields.split(), fielddata):
            self._item[k] = v
    def plain(self, text, **opts):
        '''show raw text for non-templated mode'''
        pass
    def end(self):
        '''end output for the formatter'''
        if self._item is not None:
            self._showitem()

class plainformatter(baseformatter):
    '''the default text output scheme'''
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        if ui.debugflag:
            self.hexfunc = hex
        else:
            self.hexfunc = short
    def __nonzero__(self):
        return False
    def startitem(self):
        pass
    def data(self, **data):
        pass
    def write(self, fields, deftext, *fielddata, **opts):
        self._ui.write(deftext % fielddata, **opts)
    def condwrite(self, cond, fields, deftext, *fielddata, **opts):
        '''do conditional write'''
        if cond:
            self._ui.write(deftext % fielddata, **opts)
    def plain(self, text, **opts):
        self._ui.write(text, **opts)
    def end(self):
        pass

class debugformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._ui.write("%s = [\n" % self._topic)
    def _showitem(self):
        self._ui.write("    " + repr(self._item) + ",\n")
    def end(self):
        baseformatter.end(self)
        self._ui.write("]\n")

class pickleformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._data = []
    def _showitem(self):
        self._data.append(self._item)
    def end(self):
        baseformatter.end(self)
        self._ui.write(cPickle.dumps(self._data))

def _jsonifyobj(v):
    if isinstance(v, tuple):
        return '[' + ', '.join(_jsonifyobj(e) for e in v) + ']'
    elif v is None:
        return 'null'
    elif v is True:
        return 'true'
    elif v is False:
        return 'false'
    elif isinstance(v, (int, float)):
        return str(v)
    else:
        return '"%s"' % encoding.jsonescape(v)

class jsonformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._ui.write("[")
        self._ui._first = True
    def _showitem(self):
        if self._ui._first:
            self._ui._first = False
        else:
            self._ui.write(",")

        self._ui.write("\n {\n")
        first = True
        for k, v in sorted(self._item.items()):
            if first:
                first = False
            else:
                self._ui.write(",\n")
            self._ui.write('  "%s": %s' % (k, _jsonifyobj(v)))
        self._ui.write("\n }")
    def end(self):
        baseformatter.end(self)
        self._ui.write("\n]\n")

class templateformatter(baseformatter):
    def __init__(self, ui, topic, opts):
        baseformatter.__init__(self, ui, topic, opts)
        self._topic = topic
        self._t = gettemplater(ui, topic, opts.get('template', ''))
    def _showitem(self):
        g = self._t(self._topic, **self._item)
        self._ui.write(templater.stringify(g))

def lookuptemplate(ui, topic, tmpl):
    # looks like a literal template?
    if '{' in tmpl:
        return tmpl, None

    # perhaps a stock style?
    if not os.path.split(tmpl)[0]:
        mapname = (templater.templatepath('map-cmdline.' + tmpl)
                   or templater.templatepath(tmpl))
        if mapname and os.path.isfile(mapname):
            return None, mapname

    # perhaps it's a reference to [templates]
    t = ui.config('templates', tmpl)
    if t:
        try:
            tmpl = templater.unquotestring(t)
        except SyntaxError:
            tmpl = t
        return tmpl, None

    if tmpl == 'list':
        ui.write(_("available styles: %s\n") % templater.stylelist())
        raise util.Abort(_("specify a template"))

    # perhaps it's a path to a map or a template
    if ('/' in tmpl or '\\' in tmpl) and os.path.isfile(tmpl):
        # is it a mapfile for a style?
        if os.path.basename(tmpl).startswith("map-"):
            return None, os.path.realpath(tmpl)
        tmpl = open(tmpl).read()
        return tmpl, None

    # constant string?
    return tmpl, None

def gettemplater(ui, topic, spec):
    tmpl, mapfile = lookuptemplate(ui, topic, spec)
    t = templater.templater(mapfile, {})
    if tmpl:
        t.cache[topic] = tmpl
    return t

def formatter(ui, topic, opts):
    template = opts.get("template", "")
    if template == "json":
        return jsonformatter(ui, topic, opts)
    elif template == "pickle":
        return pickleformatter(ui, topic, opts)
    elif template == "debug":
        return debugformatter(ui, topic, opts)
    elif template != "":
        return templateformatter(ui, topic, opts)
    # developer config: ui.formatdebug
    elif ui.configbool('ui', 'formatdebug'):
        return debugformatter(ui, topic, opts)
    # deprecated config: ui.formatjson
    elif ui.configbool('ui', 'formatjson'):
        return jsonformatter(ui, topic, opts)
    return plainformatter(ui, topic, opts)