1/*
2 * <sys/capability.h>
3 *
4 * Copyright (C) 1997 Aleph One
5 * Copyright (C) 1997,8, 2008,19-22 Andrew G. Morgan <morgan@kernel.org>
6 *
7 * defunct POSIX.1e Standard: 25.2 Capabilities <sys/capability.h>
8 */
9
10#ifndef _SYS_CAPABILITY_H
11#define _SYS_CAPABILITY_H
12
13#ifdef __cplusplus
14extern "C" {
15#endif
16
17/*
18 * Provide a programmatic way to #ifdef around features.
19 */
20#define LIBCAP_MAJOR 2
21#define LIBCAP_MINOR 77
22
23/*
24 * This file complements the kernel file by providing prototype
25 * information for the user library.
26 */
27
28#include <sys/types.h>
29#include <stdint.h>
30
31#ifndef __user
32#define __user
33#endif
34#include <linux/capability.h>
35
36/*
37 * POSIX capability types
38 */
39
40/*
41 * Opaque capability handle (defined internally by libcap)
42 * internal capability representation
43 */
44typedef struct _cap_struct *cap_t;
45
46/* "external" capability representation is a (void *) */
47
48/*
49 * This is the type used to identify capabilities
50 */
51
52typedef int cap_value_t;
53
54/*
55 * libcap initialized first unnamed capability of the running kernel.
56 * capsh includes a runtime test to flag when this is larger than
57 * what is known to libcap... Time for a new libcap release!
58 */
59extern cap_value_t cap_max_bits(void);
60
61/*
62 * cap_proc_root reads and (optionally: when root != NULL) changes
63 * libcap's notion of where the "/proc" filesystem is mounted. When
64 * the return value is NULL, it should be interpreted as the
65 * value "/proc".
66 *
67 * Note, this is a global value and not considered thread safe to
68 * write - so the client should take suitable care when changing
69 * it.
70 *
71 * Further, libcap will allocate a memory copy for storing the
72 * replacement root, and it is this kind of memory that is returned.
73 * So, when changing the value, the caller should
74 * cap_free(the-return-value) else cause a memory leak.
75 *
76 * Note, the library uses a destructor to clean up the live allocated
77 * value of the working setting.
78 */
79extern char *cap_proc_root(const char *root);
80
81/*
82 * Set identifiers
83 */
84typedef enum {
85 CAP_EFFECTIVE = 0, /* Specifies the effective flag */
86 CAP_PERMITTED = 1, /* Specifies the permitted flag */
87 CAP_INHERITABLE = 2 /* Specifies the inheritable flag */
88} cap_flag_t;
89
90typedef enum {
91 CAP_IAB_INH = 2,
92 CAP_IAB_AMB = 3,
93 CAP_IAB_BOUND = 4
94} cap_iab_vector_t;
95
96/*
97 * An opaque generalization of the inheritable bits that includes both
98 * what ambient bits to raise and what bounding bits to *lower* (aka
99 * drop). None of these bits once set, using cap_iab_set(), affect
100 * the running process but are consulted, through the execve() system
101 * call, by the kernel. Note, the ambient bits ('A') of the running
102 * process are fragile with respect to other aspects of the "posix"
103 * (cap_t) operations: most importantly, 'A' cannot ever hold bits not
104 * present in the intersection of 'pI' and 'pP'. The kernel
105 * immediately drops all ambient caps whenever such a situation
106 * arises. Typically, the ambient bits are used to support a naive
107 * capability inheritance model - at odds with the POSIX (sic) model
108 * of inheritance where inherited (pI) capabilities need to also be
109 * wanted by the executed binary (fI) in order to become raised
110 * through exec.
111 */
112typedef struct cap_iab_s *cap_iab_t;
113
114/*
115 * These are the states available to each capability
116 */
117typedef enum {
118 CAP_CLEAR=0, /* The flag is cleared/disabled */
119 CAP_SET=1 /* The flag is set/enabled */
120} cap_flag_value_t;
121
122/*
123 * User-space capability manipulation routines
124 */
125typedef unsigned cap_mode_t;
126#define CAP_MODE_UNCERTAIN ((cap_mode_t) 0)
127#define CAP_MODE_NOPRIV ((cap_mode_t) 1)
128#define CAP_MODE_PURE1E_INIT ((cap_mode_t) 2)
129#define CAP_MODE_PURE1E ((cap_mode_t) 3)
130#define CAP_MODE_HYBRID ((cap_mode_t) 4)
131
132/* libcap/cap_alloc.c */
133extern cap_t cap_dup(cap_t);
134extern int cap_free(void *);
135extern cap_t cap_init(void);
136extern cap_iab_t cap_iab_dup(cap_iab_t);
137extern cap_iab_t cap_iab_init(void);
138
139/* libcap/cap_flag.c */
140extern int cap_get_flag(cap_t, cap_value_t, cap_flag_t, cap_flag_value_t *);
141extern int cap_set_flag(cap_t, cap_flag_t, int, const cap_value_t *,
142 cap_flag_value_t);
143extern int cap_clear(cap_t);
144extern int cap_clear_flag(cap_t, cap_flag_t);
145extern int cap_fill_flag(cap_t cap_d, cap_flag_t to,
146 cap_t ref, cap_flag_t from);
147extern int cap_fill(cap_t, cap_flag_t, cap_flag_t);
148
149#define CAP_DIFFERS(result, flag) (((result) & (1 << (flag))) != 0)
150extern int cap_compare(cap_t, cap_t);
151#define CAP_IAB_DIFFERS(result, vector) (((result) & (1 << (vector))) != 0)
152extern int cap_iab_compare(cap_iab_t, cap_iab_t);
153
154extern cap_flag_value_t cap_iab_get_vector(cap_iab_t, cap_iab_vector_t,
155 cap_value_t);
156extern int cap_iab_set_vector(cap_iab_t, cap_iab_vector_t, cap_value_t,
157 cap_flag_value_t);
158extern int cap_iab_fill(cap_iab_t, cap_iab_vector_t, cap_t, cap_flag_t);
159
160/* libcap/cap_file.c */
161extern cap_t cap_get_fd(int);
162extern cap_t cap_get_file(const char *);
163extern uid_t cap_get_nsowner(cap_t);
164extern int cap_set_fd(int, cap_t);
165extern int cap_set_file(const char *, cap_t);
166extern int cap_set_nsowner(cap_t, uid_t);
167
168/* libcap/cap_proc.c */
169extern cap_t cap_get_proc(void);
170extern cap_t cap_get_pid(pid_t);
171extern int cap_set_proc(cap_t);
172
173extern int cap_get_bound(cap_value_t);
174extern int cap_drop_bound(cap_value_t);
175#define CAP_IS_SUPPORTED(cap) (cap_get_bound(cap) >= 0)
176
177extern int cap_get_ambient(cap_value_t);
178extern int cap_set_ambient(cap_value_t, cap_flag_value_t);
179extern int cap_reset_ambient(void);
180#define CAP_AMBIENT_SUPPORTED() (cap_get_ambient(CAP_CHOWN) >= 0)
181
182/* libcap/cap_extint.c */
183extern ssize_t cap_size(cap_t cap_d);
184extern ssize_t cap_copy_ext(void *cap_ext, cap_t cap_d, ssize_t length);
185extern cap_t cap_copy_int(const void *cap_ext);
186extern cap_t cap_copy_int_check(const void *cap_ext, ssize_t length);
187
188/* libcap/cap_text.c */
189extern cap_t cap_from_text(const char *);
190extern char * cap_to_text(cap_t, ssize_t *);
191extern int cap_from_name(const char *, cap_value_t *);
192extern char * cap_to_name(cap_value_t);
193
194extern char * cap_iab_to_text(cap_iab_t iab);
195extern cap_iab_t cap_iab_from_text(const char *text);
196
197/* libcap/cap_proc.c */
198extern void cap_set_syscall(long int (*new_syscall)(long int,
199 long int, long int, long int),
200 long int (*new_syscall6)(long int,
201 long int, long int, long int,
202 long int, long int, long int));
203
204extern int cap_set_mode(cap_mode_t flavor);
205extern cap_mode_t cap_get_mode(void);
206extern const char *cap_mode_name(cap_mode_t flavor);
207
208extern unsigned cap_get_secbits(void);
209extern int cap_set_secbits(unsigned bits);
210
211extern int cap_prctl(long int pr_cmd, long int arg1, long int arg2,
212 long int arg3, long int arg4, long int arg5);
213extern int cap_prctlw(long int pr_cmd, long int arg1, long int arg2,
214 long int arg3, long int arg4, long int arg5);
215extern int cap_setuid(uid_t uid);
216extern int cap_setgroups(gid_t gid, size_t ngroups, const gid_t groups[]);
217
218extern cap_iab_t cap_iab_get_proc(void);
219extern cap_iab_t cap_iab_get_pid(pid_t);
220extern int cap_iab_set_proc(cap_iab_t iab);
221
222typedef struct cap_launch_s *cap_launch_t;
223
224extern cap_launch_t cap_new_launcher(const char *arg0, const char * const *argv,
225 const char * const *envp);
226extern cap_launch_t cap_func_launcher(int (callback_fn)(void *detail));
227extern int cap_launcher_callback(cap_launch_t attr,
228 int (callback_fn)(void *detail));
229extern int cap_launcher_setuid(cap_launch_t attr, uid_t uid);
230extern int cap_launcher_setgroups(cap_launch_t attr, gid_t gid,
231 int ngroups, const gid_t *groups);
232extern int cap_launcher_set_mode(cap_launch_t attr, cap_mode_t flavor);
233extern cap_iab_t cap_launcher_set_iab(cap_launch_t attr, cap_iab_t iab);
234extern int cap_launcher_set_chroot(cap_launch_t attr, const char *chroot);
235extern pid_t cap_launch(cap_launch_t attr, void *detail);
236
237/*
238 * system calls - look to libc for function to system call
239 * mapping. Note, libcap does not use capset directly, but permits the
240 * cap_set_syscall() to redirect the system call function.
241 */
242extern int capget(cap_user_header_t header, cap_user_data_t data);
243extern int capset(cap_user_header_t header, const cap_user_data_t data);
244
245/* deprecated - use cap_get_pid() */
246extern int capgetp(pid_t pid, cap_t cap_d);
247
248/* not valid with filesystem capability support - use cap_set_proc() */
249extern int capsetp(pid_t pid, cap_t cap_d);
250
251#ifdef __cplusplus
252}
253#endif
254
255#endif /* _SYS_CAPABILITY_H */
256