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
|
/*
* Copyright (c) 1997-8,2007,2011 Andrew G Morgan <morgan@kernel.org>
*
* This file deals with getting and setting capabilities on processes.
*/
#include <sys/prctl.h>
#include "libcap.h"
cap_t cap_get_proc(void)
{
cap_t result;
/* allocate a new capability set */
result = cap_init();
if (result) {
_cap_debug("getting current process' capabilities");
/* fill the capability sets via a system call */
if (capget(&result->head, &result->u[0].set)) {
cap_free(result);
result = NULL;
}
}
return result;
}
int cap_set_proc(cap_t cap_d)
{
int retval;
if (!good_cap_t(cap_d)) {
errno = EINVAL;
return -1;
}
_cap_debug("setting process capabilities");
retval = capset(&cap_d->head, &cap_d->u[0].set);
return retval;
}
/* the following two functions are not required by POSIX */
/* read the caps on a specific process */
int capgetp(pid_t pid, cap_t cap_d)
{
int error;
if (!good_cap_t(cap_d)) {
errno = EINVAL;
return -1;
}
_cap_debug("getting process capabilities for proc %d", pid);
cap_d->head.pid = pid;
error = capget(&cap_d->head, &cap_d->u[0].set);
cap_d->head.pid = 0;
return error;
}
/* allocate space for and return capabilities of target process */
cap_t cap_get_pid(pid_t pid)
{
cap_t result;
result = cap_init();
if (result) {
if (capgetp(pid, result) != 0) {
int my_errno;
my_errno = errno;
cap_free(result);
errno = my_errno;
result = NULL;
}
}
return result;
}
/* set the caps on a specific process/pg etc.. */
int capsetp(pid_t pid, cap_t cap_d)
{
int error;
if (!good_cap_t(cap_d)) {
errno = EINVAL;
return -1;
}
_cap_debug("setting process capabilities for proc %d", pid);
cap_d->head.pid = pid;
error = capset(&cap_d->head, &cap_d->u[0].set);
cap_d->head.version = _LIBCAP_CAPABILITY_VERSION;
cap_d->head.pid = 0;
return error;
}
/* the kernel api requires unsigned long arguments */
#define pr_arg(x) ((unsigned long) x)
/* get a capability from the bounding set */
int cap_get_bound(cap_value_t cap)
{
int result;
result = prctl(PR_CAPBSET_READ, pr_arg(cap));
if (result < 0) {
errno = -result;
return -1;
}
return result;
}
/* drop a capability from the bounding set */
int cap_drop_bound(cap_value_t cap)
{
int result;
result = prctl(PR_CAPBSET_DROP, pr_arg(cap));
if (result < 0) {
errno = -result;
return -1;
}
return result;
}
/* get a capability from the ambient set */
int cap_get_ambient(cap_value_t cap)
{
int result;
result = prctl(PR_CAP_AMBIENT, pr_arg(PR_CAP_AMBIENT_IS_SET),
pr_arg(cap), pr_arg(0), pr_arg(0));
if (result < 0) {
errno = -result;
return -1;
}
return result;
}
/* modify a single ambient capability value */
int cap_set_ambient(cap_value_t cap, cap_flag_value_t set)
{
int result, val;
switch (set) {
case CAP_SET:
val = PR_CAP_AMBIENT_RAISE;
break;
case CAP_CLEAR:
val = PR_CAP_AMBIENT_LOWER;
break;
default:
errno = EINVAL;
return -1;
}
result = prctl(PR_CAP_AMBIENT, pr_arg(val), pr_arg(cap),
pr_arg(0), pr_arg(0));
if (result < 0) {
errno = -result;
return -1;
}
return result;
}
/* erase all ambient capabilities */
int cap_reset_ambient()
{
int result;
result = prctl(PR_CAP_AMBIENT, pr_arg(PR_CAP_AMBIENT_CLEAR_ALL),
pr_arg(0), pr_arg(0), pr_arg(0));
if (result < 0) {
errno = -result;
return -1;
}
return result;
}
|
