Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

from xfeatures import XFeatures

from groups import Groups

from public import Public

from node import Node

from collections import defaultdict

READ = 0

WRITE = 1

class Permissions(XFeatures, Groups, Public, Node):

    def __init__(self, **params):

        XFeatures.__init__(self, **params)

        Groups.__init__(self, **params)

        Public.__init__(self, **params)

        Node.__init__(self, **params)

    def access_grant(self, path, access, members=()):

        """Grant members with access to path.

           Members can also be '*' (all),

           or some group specified as 'owner:group'."""

        if not members:

            return

        feature = self.xfeature_create(path)

        self.feature_setmany(feature, access, members)

    def access_set(self, path, permissions):

        """Set permissions for path. The permissions dict

           maps 'read', 'write' keys to member lists."""

        r = permissions.get('read', [])

        w = permissions.get('write', [])

        if not r and not w:

            self.xfeature_destroy(path)

            return

        feature = self.xfeature_create(path)

        self.feature_clear(feature, READ)

        self.feature_clear(feature, WRITE)

        if r:

            self.feature_setmany(feature, READ, r)

        if w:

            self.feature_setmany(feature, WRITE, w)

    def access_get_for_bulk(self, perms):

        """Get permissions for paths."""

        allowed = None

        d = defaultdict(list)

        for value, feature_id, key in perms:

            d[key].append(value)

        permissions = d

        if READ in permissions:

            allowed = 0

            permissions['read'] = permissions[READ]

            del(permissions[READ])

        if WRITE in permissions:

            allowed = 1

            permissions['write'] = permissions[WRITE]

            del(permissions[WRITE])

        return (permissions, allowed)

    def access_get(self, path):

        """Get permissions for path."""

        feature = self.xfeature_get(path)

        if not feature:

            return {}

        permissions = self.feature_dict(feature)

        if READ in permissions:

            permissions['read'] = permissions[READ]

            del(permissions[READ])

        if WRITE in permissions:

            permissions['write'] = permissions[WRITE]

            del(permissions[WRITE])

        return permissions

    def access_members(self, path):

        feature = self.xfeature_get(path)

        if not feature:

            return []

        permissions = self.feature_dict(feature)

        members = set()

        members.update(permissions.get(READ, []))

        members.update(permissions.get(WRITE, []))

        for m in set(members):

            parts = m.split(':', 1)

            if len(parts) != 2:

                continue

            user, group = parts

            members.remove(m)

            members.update(self.group_members(user, group))

        return members

    def access_clear(self, path):

        """Revoke access to path (both permissions and public)."""

        self.xfeature_destroy(path)

        self.public_unset(path)

    def access_clear_bulk(self, paths):

        """Revoke access to path (both permissions and public)."""

        self.xfeature_destroy_bulk(paths)

        self.public_unset_bulk(paths)

    def access_check(self, path, access, member):

        """Return true if the member has this access to the path."""

        feature = self.xfeature_get(path)

        if not feature:

            return False

        members = self.feature_get(feature, access)

        if member in members or '*' in members:

            return True

        for owner, group in self.group_parents(member):

            if owner + ':' + group in members:

                return True

        return False

    def access_check_bulk(self, paths, member):

        rows = None

        q = ("select x.path, xvals.value, xvals.feature_id, xvals.key "

             "from xfeaturevals xvals join xfeatures x "

             "on xvals.feature_id = x.feature_id "

             "where x.path in (%s)") % ','.join('?' for _ in paths)

        self.execute(q, paths)

        rows = self.fetchall()

        if rows:

            access_check_paths = {}

            for path, value, feature_id, key in rows:

                try:

                    access_check_paths[path].append((value, feature_id, key))

                except KeyError:

                    access_check_paths[path] = [(value, feature_id, key)]

            return access_check_paths

        return None

    def access_inherit(self, path):

        """Return the paths influencing the access for path."""

#         r = self.xfeature_inherit(path)

#         if not r:

#             return []

#         # Compute valid.

#         return [x[0] for x in r if x[0] in valid]

        # Only keep path components.

        parts = path.rstrip('/').split('/')

        valid = []

        for i in range(1, len(parts)):

            subp = '/'.join(parts[:i + 1])

            valid.append(subp)

            if subp != path:

                valid.append(subp + '/')

        return [x for x in valid if self.xfeature_get(x)]

    def access_inherit_bulk(self, paths):

        """Return the paths influencing the access for paths."""

        # Only keep path components.

        valid = []

        for path in paths:

            parts = path.rstrip('/').split('/')

            for i in range(1, len(parts)):

                subp = '/'.join(parts[:i + 1])

                valid.append(subp)

                if subp != path:

                    valid.append(subp + '/')

        valid = self.xfeature_get_bulk(valid)

        return [x[1] for x in valid]

    def access_list_paths(self, member, prefix=None, include_owned=False,

                          include_containers=True):

        """Return the list of paths granted to member.

        Keyword arguments:

        prefix -- return only paths starting with prefix (default None)

        include_owned -- return also paths owned by member (default False)

        include_containers -- return also container paths owned by member

                              (default True)

        """

        q = ("select distinct path from xfeatures inner join "

             "  (select distinct feature_id, key from xfeaturevals inner join "

             "     (select owner || ':' || name as value from groups "

             "      where member = ? union select ? union select '*') "

             "   using (value)) "

             "using (feature_id)")

        p = (member, member)

        if prefix:

            q += " where "

            paths = self.access_inherit(prefix) or [prefix]

            q += ' or '.join("path like ? escape '\\'" for _ in paths)

            p += tuple(self.escape_like(path) + '%' for path in paths)

        self.execute(q, p)

        l = [r[0] for r in self.fetchall()]

        if include_owned:

            node = self.node_lookup(member)

            select_containers = "select node from nodes where parent = ? "

            q = ("select path from nodes where parent in (%s) " %

                 select_containers)

            args = [node]

            if include_containers:

                q += ("or node in (%s)" % select_containers)

                args += [node]

            self.execute(q, args)

            l += [r[0] for r in self.fetchall() if r[0] not in l]

        return l

    def access_list_shared(self, prefix=''):

        """Return the list of shared paths."""

        q = "select path from xfeatures where "

        paths = self.access_inherit(prefix) or [prefix]

        q += ' or '.join("path like ? escape '\\'" for _ in paths)

        p = tuple(self.escape_like(path) + '%' for path in paths)

        self.execute(q, p)

        return [r[0] for r in self.fetchall()]