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
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd 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 2 of the License, or
(at your option) any later version.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdarg.h>
#include <ctype.h>
#include <sys/capability.h>
#include <sys/prctl.h>
#include "macro.h"
#include "capability.h"
#include "util.h"
#include "log.h"
int have_effective_cap(int value) {
cap_t cap;
cap_flag_value_t fv;
int r;
if (!(cap = cap_get_proc()))
return -errno;
if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0)
r = -errno;
else
r = fv == CAP_SET;
cap_free(cap);
return r;
}
unsigned long cap_last_cap(void) {
static __thread unsigned long saved;
static __thread bool valid = false;
unsigned long p;
if (valid)
return saved;
p = (unsigned long) CAP_LAST_CAP;
if (prctl(PR_CAPBSET_READ, p) < 0) {
/* Hmm, look downwards, until we find one that
* works */
for (p--; p > 0; p --)
if (prctl(PR_CAPBSET_READ, p) >= 0)
break;
} else {
/* Hmm, look upwards, until we find one that doesn't
* work */
for (;; p++)
if (prctl(PR_CAPBSET_READ, p+1) < 0)
break;
}
saved = p;
valid = true;
return p;
}
|
