1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/* Copyright (C) 1989, 1991-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <errno.h>
#include <grp.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/types.h>
#include <nsswitch.h>
#include <scratch_buffer.h>
#include <config.h>
#include "../nscd/nscd-client.h"
#include "../nscd/nscd_proto.h"
#ifdef LINK_OBSOLETE_NSL
# define DEFAULT_CONFIG "compat [NOTFOUND=return] files"
#else
# define DEFAULT_CONFIG "files"
#endif
/* Type of the lookup function. */
typedef enum nss_status (*initgroups_dyn_function) (const char *, gid_t,
long int *, long int *,
gid_t **, long int, int *);
static bool use_initgroups_entry;
#include "compat-initgroups.c"
static int
internal_getgrouplist (const char *user, gid_t group, long int *size,
gid_t **groupsp, long int limit)
{
#ifdef USE_NSCD
if (__nss_not_use_nscd_group > 0
&& ++__nss_not_use_nscd_group > NSS_NSCD_RETRY)
__nss_not_use_nscd_group = 0;
if (!__nss_not_use_nscd_group
&& !__nss_database_custom[NSS_DBSIDX_group])
{
int n = __nscd_getgrouplist (user, group, size, groupsp, limit);
if (n >= 0)
return n;
/* nscd is not usable. */
__nss_not_use_nscd_group = 1;
}
#endif
enum nss_status status = NSS_STATUS_UNAVAIL;
int no_more = 0;
/* Never store more than the starting *SIZE number of elements. */
assert (*size > 0);
(*groupsp)[0] = group;
/* Start is one, because we have the first group as parameter. */
long int start = 1;
if (__nss_initgroups_database == NULL)
{
if (__nss_database_lookup ("initgroups", NULL, "",
&__nss_initgroups_database) < 0)
{
if (__nss_group_database == NULL)
no_more = __nss_database_lookup ("group", NULL, DEFAULT_CONFIG,
&__nss_group_database);
__nss_initgroups_database = __nss_group_database;
}
else
use_initgroups_entry = true;
}
else
/* __nss_initgroups_database might have been set through
__nss_configure_lookup in which case use_initgroups_entry was
not set here. */
use_initgroups_entry = __nss_initgroups_database != __nss_group_database;
service_user *nip = __nss_initgroups_database;
while (! no_more)
{
long int prev_start = start;
initgroups_dyn_function fct = __nss_lookup_function (nip,
"initgroups_dyn");
if (fct == NULL)
status = compat_call (nip, user, group, &start, size, groupsp,
limit, &errno);
else
status = DL_CALL_FCT (fct, (user, group, &start, size, groupsp,
limit, &errno));
/* Remove duplicates. */
long int cnt = prev_start;
while (cnt < start)
{
long int inner;
for (inner = 0; inner < prev_start; ++inner)
if ((*groupsp)[inner] == (*groupsp)[cnt])
break;
if (inner < prev_start)
(*groupsp)[cnt] = (*groupsp)[--start];
else
++cnt;
}
/* This is really only for debugging. */
if (NSS_STATUS_TRYAGAIN > status || status > NSS_STATUS_RETURN)
__libc_fatal ("illegal status in internal_getgrouplist");
/* For compatibility reason we will continue to look for more
entries using the next service even though data has already
been found if the nsswitch.conf file contained only a 'groups'
line and no 'initgroups' line. If the latter is available
we always respect the status. This means that the default
for successful lookups is to return. */
if ((use_initgroups_entry || status != NSS_STATUS_SUCCESS)
&& nss_next_action (nip, status) == NSS_ACTION_RETURN)
break;
if (nip->next == NULL)
no_more = -1;
else
nip = nip->next;
}
return start;
}
/* Store at most *NGROUPS members of the group set for USER into
*GROUPS. Also include GROUP. The actual number of groups found is
returned in *NGROUPS. Return -1 if the if *NGROUPS is too small. */
int
getgrouplist (const char *user, gid_t group, gid_t *groups, int *ngroups)
{
long int size = MAX (1, *ngroups);
gid_t *newgroups = (gid_t *) malloc (size * sizeof (gid_t));
if (__glibc_unlikely (newgroups == NULL))
/* No more memory. */
// XXX This is wrong. The user provided memory, we have to use
// XXX it. The internal functions must be called with the user
// XXX provided buffer and not try to increase the size if it is
// XXX too small. For initgroups a flag could say: increase size.
return -1;
int total = internal_getgrouplist (user, group, &size, &newgroups, -1);
memcpy (groups, newgroups, MIN (*ngroups, total) * sizeof (gid_t));
free (newgroups);
int retval = total > *ngroups ? -1 : total;
*ngroups = total;
return retval;
}
nss_interface_function (getgrouplist)
/* Initialize the group set for the current user
by reading the group database and using all groups
of which USER is a member. Also include GROUP. */
int
initgroups (const char *user, gid_t group)
{
#if defined NGROUPS_MAX && NGROUPS_MAX == 0
/* No extra groups allowed. */
return 0;
#else
long int size;
gid_t *groups;
int ngroups;
int result;
/* We always use sysconf even if NGROUPS_MAX is defined. That way, the
limit can be raised in the kernel configuration without having to
recompile libc. */
long int limit = __sysconf (_SC_NGROUPS_MAX);
if (limit > 0)
/* We limit the size of the intially allocated array. */
size = MIN (limit, 64);
else
/* No fixed limit on groups. Pick a starting buffer size. */
size = 16;
groups = (gid_t *) malloc (size * sizeof (gid_t));
if (__glibc_unlikely (groups == NULL))
/* No more memory. */
return -1;
ngroups = internal_getgrouplist (user, group, &size, &groups, limit);
/* Try to set the maximum number of groups the kernel can handle. */
do
result = setgroups (ngroups, groups);
while (result == -1 && errno == EINVAL && --ngroups > 0);
free (groups);
return result;
#endif
}
nss_interface_function (initgroups)
|
