/samba-3.5.6/source3/lib/system_smbd.c
C | 198 lines | 123 code | 30 blank | 45 comment | 25 complexity | bd5e5f117629c6745168b376d2e48aba MD5 | raw file
- /*
- Unix SMB/CIFS implementation.
- system call wrapper interface.
- Copyright (C) Andrew Tridgell 2002
- Copyright (C) Andrew Barteltt 2002
- This program 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; either version 3 of the License, or
- (at your option) any later version.
-
- 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/>.
- */
- /*
- This file may assume linkage with smbd - for things like become_root()
- etc.
- */
- #include "includes.h"
- #ifndef HAVE_GETGROUPLIST
- /*
- This is a *much* faster way of getting the list of groups for a user
- without changing the current supplementary group list. The old
- method used getgrent() which could take 20 minutes on a really big
- network with hundeds of thousands of groups and users. The new method
- takes a couple of seconds.
- NOTE!! this function only works if it is called as root!
- */
- static int getgrouplist_internals(const char *user, gid_t gid, gid_t *groups,
- int *grpcnt)
- {
- gid_t *gids_saved;
- int ret, ngrp_saved, num_gids;
- if (non_root_mode()) {
- *grpcnt = 0;
- return 0;
- }
- /* work out how many groups we need to save */
- ngrp_saved = getgroups(0, NULL);
- if (ngrp_saved == -1) {
- /* this shouldn't happen */
- return -1;
- }
- gids_saved = SMB_MALLOC_ARRAY(gid_t, ngrp_saved+1);
- if (!gids_saved) {
- errno = ENOMEM;
- return -1;
- }
- ngrp_saved = getgroups(ngrp_saved, gids_saved);
- if (ngrp_saved == -1) {
- SAFE_FREE(gids_saved);
- /* very strange! */
- return -1;
- }
- if (initgroups(user, gid) != 0) {
- DEBUG(0, ("getgrouplist_internals: initgroups() failed!\n"));
- SAFE_FREE(gids_saved);
- return -1;
- }
- /* this must be done to cope with systems that put the current egid in the
- return from getgroups() */
- save_re_gid();
- set_effective_gid(gid);
- setgid(gid);
- num_gids = getgroups(0, NULL);
- if (num_gids == -1) {
- SAFE_FREE(gids_saved);
- /* very strange! */
- return -1;
- }
- if (num_gids + 1 > *grpcnt) {
- *grpcnt = num_gids + 1;
- ret = -1;
- } else {
- ret = getgroups(*grpcnt - 1, &groups[1]);
- if (ret < 0) {
- SAFE_FREE(gids_saved);
- /* very strange! */
- return -1;
- }
- groups[0] = gid;
- *grpcnt = ret + 1;
- }
- restore_re_gid();
- if (sys_setgroups(gid, ngrp_saved, gids_saved) != 0) {
- /* yikes! */
- DEBUG(0,("ERROR: getgrouplist: failed to reset group list!\n"));
- smb_panic("getgrouplist: failed to reset group list!");
- }
- free(gids_saved);
- return ret;
- }
- #endif
- static int sys_getgrouplist(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
- {
- int retval;
- bool winbind_env;
- DEBUG(10,("sys_getgrouplist: user [%s]\n", user));
- /* This is only ever called for Unix users, remote memberships are
- * always determined by the info3 coming back from auth3 or the
- * PAC. */
- winbind_env = winbind_env_set();
- (void)winbind_off();
- #ifdef HAVE_GETGROUPLIST
- retval = getgrouplist(user, gid, groups, grpcnt);
- #else
- become_root();
- retval = getgrouplist_internals(user, gid, groups, grpcnt);
- unbecome_root();
- #endif
- /* allow winbindd lookups, but only if they were not already disabled */
- if (!winbind_env) {
- (void)winbind_on();
- }
- return retval;
- }
- bool getgroups_unix_user(TALLOC_CTX *mem_ctx, const char *user,
- gid_t primary_gid,
- gid_t **ret_groups, size_t *p_ngroups)
- {
- size_t ngrp;
- int max_grp;
- gid_t *temp_groups;
- gid_t *groups;
- int i;
- max_grp = MIN(128, groups_max());
- temp_groups = SMB_MALLOC_ARRAY(gid_t, max_grp);
- if (! temp_groups) {
- return False;
- }
- if (sys_getgrouplist(user, primary_gid, temp_groups, &max_grp) == -1) {
- temp_groups = SMB_REALLOC_ARRAY(temp_groups, gid_t, max_grp);
- if (!temp_groups) {
- return False;
- }
-
- if (sys_getgrouplist(user, primary_gid,
- temp_groups, &max_grp) == -1) {
- DEBUG(0, ("get_user_groups: failed to get the unix "
- "group list\n"));
- SAFE_FREE(temp_groups);
- return False;
- }
- }
-
- ngrp = 0;
- groups = NULL;
- /* Add in primary group first */
- if (!add_gid_to_array_unique(mem_ctx, primary_gid, &groups, &ngrp)) {
- SAFE_FREE(temp_groups);
- return False;
- }
- for (i=0; i<max_grp; i++) {
- if (!add_gid_to_array_unique(mem_ctx, temp_groups[i],
- &groups, &ngrp)) {
- SAFE_FREE(temp_groups);
- return False;
- }
- }
- *p_ngroups = ngrp;
- *ret_groups = groups;
- SAFE_FREE(temp_groups);
- return True;
- }