sssd_id.py revision 19398379a221a11755c77bb157864dfa9f465488
#
# Module for simulation of utility "id" from coreutils
#
# Copyright (c) 2015 Red Hat, Inc.
# Author: Lukas Slebodnik <lslebodn@redhat.com>
#
# This is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 only
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import config
import pwd
import grp
from ctypes import (cdll, c_int, c_char, c_uint32, c_long, c_char_p,
POINTER, pointer)
class NssReturnCode(object):
""" 'enum' class for name service switch return code """
TRYAGAIN = -2,
UNAVAIL = -1
NOTFOUND = 0
SUCCESS = 1
RETURN = 2
def call_sssd_initgroups(user, gid):
"""
Function will initialize the supplementary group access list
for given user. It will gather groups only provided by sssd.
Arguments are the same as for C function initgroups
@param string user name of user
@param int gid the additional gid will be also added to the list.
@return (int, int, List[int]) (err, errno, gids)
gids should contain user group IDs if err is NssReturnCode.SUCCESS
otherwise errno will contain non-zero value.
"""
libnss_sss_path = config.NSS_MODULE_DIR + "/libnss_sss.so.2"
libnss_sss = cdll.LoadLibrary(libnss_sss_path)
func = libnss_sss._nss_sss_initgroups_dyn
func.restype = c_int
func.argtypes = [POINTER(c_char), c_uint32, POINTER(c_long),
POINTER(c_long), POINTER(POINTER(c_uint32)), c_long,
POINTER(c_int)]
start = POINTER(c_long)(c_long(0))
size = POINTER(c_long)(c_long(0))
groups = POINTER(c_uint32)()
p_groups = pointer(groups)
limit = c_long(-1)
errno = POINTER(c_int)(c_int(0))
res = func(c_char_p(user.encode('utf-8)')), c_uint32(gid), start, size,
p_groups, limit, errno)
gids = []
if res == NssReturnCode.SUCCESS:
gids_count = size[0]
assert gids_count > 0, "_nss_sss_initgroups_dyn should return " \
"one gid"
for i in range(0, gids_count):
gids.append(int(p_groups.contents[i]))
# add primary group if missing
if gid not in gids:
gids.append(gid)
return (int(res), errno[0], gids)
def get_user_gids(user):
"""
Function will initialize the supplementary group access list
for given user. It will gather groups only provided by sssd.
Arguments are the same as for C function initgroups
@param string user name of user
@return (int, int, List[int]) (err, errno, gids)
gids should contain user group IDs if err is NssReturnCode.SUCCESS
otherwise errno will contain non-zero value.
"""
pwd_user = pwd.getpwnam(user)
uid = pwd_user.pw_uid
gid = pwd_user.pw_gid
user = pwd.getpwuid(uid).pw_name
return call_sssd_initgroups(user, gid)
def gid_to_str(gid):
"""
Function will map numeric GID into names.
If there isn't a group for GID (getgrgid failed)
then the function will return decimal representation of ID.
@param int gid ID of groups which should be converted to string.
@return string name of group with requested ID or decimal
representation of ID
"""
try:
return grp.getgrgid(gid).gr_name
except KeyError:
return str(gid)
def get_user_groups(user):
"""
Function will initialize the supplementary group access list
for given user. It will gather groups only provided by sssd.
Arguments are the same as for C function initgroups
@param string user name of user
@return (int, int, List[string]) (err, errno, groups)
groups should contain names of user groups
if err is NssReturnCode.SUCCESS
otherwise errno will contain non-zero value.
"""
(res, errno, gids) = get_user_gids(user)
groups = []
if res == NssReturnCode.SUCCESS:
groups = [gid_to_str(gid) for gid in gids]
return (res, errno, groups)