2 * Zebra privileges header.
4 * Copyright (C) 2003 Paul Jakma.
6 * This file is part of GNU Zebra.
8 * GNU Zebra is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2, or (at your option) any
13 * GNU Zebra is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; see the file COPYING; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 #ifndef _ZEBRA_PRIVS_H
24 #define _ZEBRA_PRIVS_H
27 #include "lib/queue.h"
33 /* list of zebra capabilities */
47 } zebra_capabilities_t
;
53 } zebra_privs_current_t
;
60 struct zebra_privs_refs_t
{
61 STAILQ_ENTRY(zebra_privs_refs_t
) entry
;
64 const char *raised_in_funcname
;
67 struct zebra_privs_t
{
68 zebra_capabilities_t
*caps_p
; /* caps required for operation */
69 zebra_capabilities_t
*caps_i
; /* caps to allow inheritance of */
70 int cap_num_p
; /* number of caps in arrays */
73 /* Mutex and counter used to avoid race conditions in multi-threaded
74 * processes. If privs status is process-wide, we need to
75 * control changes to the privilege status among threads.
76 * If privs changes are per-thread, we need to be able to
79 pthread_mutex_t mutex
;
80 struct zebra_privs_refs_t process_refs
;
82 STAILQ_HEAD(thread_refs_q
, zebra_privs_refs_t
) thread_refs
;
84 const char *user
; /* user and group to run as */
86 const char *vty_group
; /* group to chown vty socket to */
88 int (*change
)(zebra_privs_ops_t
); /* change privileges, 0 on success */
89 zebra_privs_current_t (*current_state
)(
90 void); /* current privilege state */
95 uid_t uid_priv
; /* privileged uid */
96 uid_t uid_normal
; /* normal uid */
97 gid_t gid_priv
; /* privileged uid */
98 gid_t gid_normal
; /* normal uid */
99 gid_t gid_vty
; /* vty gid */
102 /* initialise zebra privileges */
103 extern void zprivs_preinit(struct zebra_privs_t
*zprivs
);
104 extern void zprivs_init(struct zebra_privs_t
*zprivs
);
105 /* drop all and terminate privileges */
106 extern void zprivs_terminate(struct zebra_privs_t
*);
107 /* query for runtime uid's and gid's, eg vty needs this */
108 extern void zprivs_get_ids(struct zprivs_ids_t
*);
111 * Wrapper around zprivs, to be used as:
112 * frr_elevate_privs(&privs) {
115 * break; -- break can be used to get out of the block
119 * The argument to frr_elevate_privs() can be NULL to leave privileges as-is
120 * (mostly useful for conditional privilege-raising, i.e.:)
121 * frr_elevate_privs(cond ? &privs : NULL) {}
123 * NB: The code block is always executed, regardless of whether privileges
124 * could be raised or not, or whether NULL was given or not. This is fully
125 * intentional; the user may have configured some RBAC or similar that we
126 * are not aware of, but that allows our code to proceed without privileges.
128 * The point of this wrapper is to prevent accidental bugs where privileges
129 * are elevated but then not dropped. This can happen when, for example, a
130 * "return", "goto" or "break" in the middle of the elevated-privilege code
131 * skips past the privilege dropping call.
133 * The macro below uses variable cleanup to drop privileges as soon as the
134 * code block is left in any way (and thus the _privs variable goes out of
135 * scope.) _once is just a trick to run the loop exactly once.
137 extern struct zebra_privs_t
*_zprivs_raise(struct zebra_privs_t
*privs
,
138 const char *funcname
);
139 extern void _zprivs_lower(struct zebra_privs_t
**privs
);
141 #define frr_elevate_privs(privs) \
142 for (struct zebra_privs_t *_once = NULL, \
143 *_privs __attribute__( \
144 (unused, cleanup(_zprivs_lower))) = \
145 _zprivs_raise(privs, __func__); \
146 _once == NULL; _once = (void *)1)
152 #endif /* _ZEBRA_PRIVS_H */