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
|
/*
File: uid_gid_lookup.c
Copyright (C) 2023 Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
This 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.
This 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 this library; if not, see <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <unistd.h>
#include "libacl.h"
#include "misc.h"
int
get_id(const char *token, id_t *id_p)
{
char *ep;
long l;
l = strtol(token, &ep, 0);
if (*ep != '\0')
return -1;
if (l < 0) {
/*
Negative values are interpreted as 16-bit numbers
so that id -2 maps to 65534 (nobody/nogroup), etc.
*/
l &= 0xFFFF;
}
*id_p = l;
return 0;
}
static char *
grow_buffer(char **buffer, size_t *bufsize, int type)
{
long size = *bufsize;
char *buf;
if (!size) {
size = sysconf(type);
if (size <= 0)
size = 16384;
} else {
size *= 2;
}
buf = realloc(*buffer, size);
if (buf) {
*buffer = buf;
*bufsize = size;
}
return buf;
}
int
get_uid(const char *token, uid_t *uid_p)
{
struct passwd passwd, *result = NULL;
char *buffer = NULL;
size_t bufsize = 0;
int err;
if (get_id(token, uid_p) == 0)
return 0;
for(;;) {
if(!grow_buffer(&buffer, &bufsize, _SC_GETPW_R_SIZE_MAX))
break;
err = getpwnam_r(token, &passwd, buffer, bufsize, &result);
if (result) {
*uid_p = passwd.pw_uid;
break;
}
if (err == ERANGE)
continue;
errno = err ? err : EINVAL;
break;
}
free(buffer);
return result ? 0 : -1;
}
int
get_gid(const char *token, gid_t *gid_p)
{
struct group group, *result = NULL;
char *buffer = NULL;
size_t bufsize = 0;
int err;
if (get_id(token, (uid_t *)gid_p) == 0)
return 0;
for(;;) {
if(!grow_buffer(&buffer, &bufsize, _SC_GETGR_R_SIZE_MAX))
break;
err = getgrnam_r(token, &group, buffer, bufsize, &result);
if (result) {
*gid_p = group.gr_gid;
break;
}
if (err == ERANGE)
continue;
errno = err ? err : EINVAL;
break;
}
free(buffer);
return result ? 0 : -1;
}
|