1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef _SYS_UCRED_H_
33 #define _SYS_UCRED_H_
34
35 #include <sys/types.h>
36 #if defined(_KERNEL) || defined(_WANT_UCRED)
37 #include <sys/_lock.h>
38 #include <sys/_mutex.h>
39 #endif
40 #include <bsm/audit.h>
41
42 #if defined(_KERNEL) || defined(_WANT_UCRED)
43 /*
44 * Flags for cr_flags.
45 */
46 #define CRED_FLAG_CAPMODE 0x00000001 /* In capability mode. */
47 #define CRED_FLAG_GROUPSET 0x00000002 /* Groups have been set. */
48
49 /*
50 * Number of groups inlined in 'struct ucred'. It must stay reasonably low as
51 * it is also used by some functions to allocate an array of this size on the
52 * stack.
53 */
54 #define CRED_SMALLGROUPS_NB 16
55
56 struct label;
57 struct loginclass;
58 struct prison;
59 struct uidinfo;
60
61 /*
62 * Credentials.
63 *
64 * Please do not inspect cr_uid directly to determine superuserness. The
65 * priv(9) interface should be used to check for privilege.
66 *
67 * Lock reference:
68 * c - cr_mtx
69 *
70 * Unmarked fields are constant after creation.
71 *
72 * See "Credential management" comment in kern_prot.c for more information.
73 */
74 struct ucred {
75 struct mtx cr_mtx;
76 long cr_ref; /* (c) reference count */
77 u_int cr_users; /* (c) proc + thread using this cred */
78 u_int cr_flags; /* credential flags */
79 struct auditinfo_addr cr_audit; /* Audit properties. */
80 int cr_ngroups; /* number of supplementary groups */
81 #define cr_startcopy cr_uid
82 uid_t cr_uid; /* effective user id */
83 uid_t cr_ruid; /* real user id */
84 uid_t cr_svuid; /* saved user id */
85 gid_t cr_gid; /* effective group id */
86 gid_t cr_rgid; /* real group id */
87 gid_t cr_svgid; /* saved group id */
88 struct uidinfo *cr_uidinfo; /* per euid resource consumption */
89 struct uidinfo *cr_ruidinfo; /* per ruid resource consumption */
90 struct prison *cr_prison; /* jail(2) */
91 struct loginclass *cr_loginclass; /* login class */
92 void *cr_pspare2[2]; /* general use 2 */
93 #define cr_endcopy cr_label
94 struct label *cr_label; /* MAC label */
95 gid_t *cr_groups; /* groups */
96 int cr_agroups; /* Available groups */
97 /* storage for small groups */
98 gid_t cr_smallgroups[CRED_SMALLGROUPS_NB];
99 };
100 #define NOCRED ((struct ucred *)0) /* no credential available */
101 #define FSCRED ((struct ucred *)-1) /* filesystem credential */
102 #endif /* _KERNEL || _WANT_UCRED */
103
104 #define XU_NGROUPS 16
105
106 /*
107 * This is the external representation of struct ucred.
108 */
109 struct xucred {
110 u_int cr_version; /* structure layout version */
111 uid_t cr_uid; /* effective user id */
112 short cr_ngroups; /* number of groups (incl. cr_gid). */
113 union {
114 /*
115 * The effective GID has been the first element of cr_groups[]
116 * for historical reasons. It should be accessed using the
117 * 'cr_gid' identifier. Supplementary groups should be accessed
118 * using cr_sgroups[]. Note that 'cr_ngroups' currently
119 * includes the effective GID.
120 *
121 * XXXOC: On the next API change (requires versioning), please
122 * replace this union with a true unaliased field 'cr_gid' and
123 * make sure that cr_groups[]/'cr_ngroups' only account for
124 * supplementary groups.
125 */
126 struct {
127 gid_t cr_gid; /* effective group id */
128 gid_t cr_sgroups[XU_NGROUPS - 1];
129 };
130 gid_t cr_groups[XU_NGROUPS]; /* groups */
131 };
132 union {
133 void *_cr_unused1; /* compatibility with old ucred */
134 pid_t cr_pid;
135 };
136 };
137 #define XUCRED_VERSION 0
138
139 struct mac;
140 /*
141 * Structure to pass as an argument to the setcred() system call.
142 */
143 struct setcred {
144 uid_t sc_uid; /* effective user id */
145 uid_t sc_ruid; /* real user id */
146 uid_t sc_svuid; /* saved user id */
147 gid_t sc_gid; /* effective group id */
148 gid_t sc_rgid; /* real group id */
149 gid_t sc_svgid; /* saved group id */
150 u_int sc_pad; /* see 32-bit compat structure */
151 u_int sc_supp_groups_nb; /* number of supplementary groups */
152 gid_t *sc_supp_groups; /* supplementary groups */
153 struct mac *sc_label; /* MAC label */
154 };
155 /*
156 * Initializer for 'struct setcred' variables.
157 */
158 #define SETCRED_INITIALIZER { -1, -1, -1, -1, -1, -1, 0, 0, NULL, NULL }
159
160 /*
161 * Flags to setcred().
162 */
163 #define SETCREDF_UID (1u << 0)
164 #define SETCREDF_RUID (1u << 1)
165 #define SETCREDF_SVUID (1u << 2)
166 #define SETCREDF_GID (1u << 3)
167 #define SETCREDF_RGID (1u << 4)
168 #define SETCREDF_SVGID (1u << 5)
169 #define SETCREDF_SUPP_GROUPS (1u << 6)
170 #define SETCREDF_MAC_LABEL (1u << 7)
171
172 #ifdef _KERNEL
173 /*
174 * Masks of the currently valid flags to setcred().
175 *
176 * Please consider reserving some of the high bits in the 'flags' argument for
177 * versioning when almost all of them are in use.
178 */
179 #define SETCREDF_MASK (SETCREDF_UID | SETCREDF_RUID | SETCREDF_SVUID | \
180 SETCREDF_GID | SETCREDF_RGID | SETCREDF_SVGID | SETCREDF_SUPP_GROUPS | \
181 SETCREDF_MAC_LABEL)
182
183 struct setcred32 {
184 #define setcred32_copy_start sc_uid
185 uid_t sc_uid;
186 uid_t sc_ruid;
187 uid_t sc_svuid;
188 gid_t sc_gid;
189 gid_t sc_rgid;
190 gid_t sc_svgid;
191 u_int sc_pad;
192 u_int sc_supp_groups_nb;
193 #define setcred32_copy_end sc_supp_groups
194 uint32_t sc_supp_groups; /* gid_t [*] */
195 uint32_t sc_label; /* struct mac32 [*] */
196 };
197
198 struct thread;
199
200 /* Common native and 32-bit compatibility entry point. */
201 int user_setcred(struct thread *td, const u_int flags,
202 const void *const uwcred, const size_t size, bool is_32bit);
203
204 struct proc;
205
206 struct credbatch {
207 struct ucred *cred;
208 u_int users;
209 long ref;
210 };
211
212 static inline void
credbatch_prep(struct credbatch * crb)213 credbatch_prep(struct credbatch *crb)
214 {
215 crb->cred = NULL;
216 crb->users = 0;
217 crb->ref = 0;
218 }
219 void credbatch_add(struct credbatch *crb, struct thread *td);
220
221 static inline void
credbatch_process(struct credbatch * crb __unused)222 credbatch_process(struct credbatch *crb __unused)
223 {
224
225 }
226
227 void credbatch_final(struct credbatch *crb);
228
229 void change_egid(struct ucred *newcred, gid_t egid);
230 void change_euid(struct ucred *newcred, struct uidinfo *euip);
231 void change_rgid(struct ucred *newcred, gid_t rgid);
232 void change_ruid(struct ucred *newcred, struct uidinfo *ruip);
233 void change_svgid(struct ucred *newcred, gid_t svgid);
234 void change_svuid(struct ucred *newcred, uid_t svuid);
235 void crcopy(struct ucred *dest, struct ucred *src);
236 struct ucred *crcopysafe(struct proc *p, struct ucred *cr);
237 struct ucred *crdup(struct ucred *cr);
238 void crextend(struct ucred *cr, int n);
239 void proc_set_cred(struct proc *p, struct ucred *newcred);
240 bool proc_set_cred_enforce_proc_lim(struct proc *p, struct ucred *newcred);
241 void proc_unset_cred(struct proc *p, bool decrement_proc_count);
242 void crfree(struct ucred *cr);
243 struct ucred *crcowsync(void);
244 struct ucred *crget(void);
245 struct ucred *crhold(struct ucred *cr);
246 struct ucred *crcowget(struct ucred *cr);
247 void crcowfree(struct thread *td);
248 void cru2x(struct ucred *cr, struct xucred *xcr);
249 void cru2xt(struct thread *td, struct xucred *xcr);
250 void crsetgroups(struct ucred *cr, int ngrp, const gid_t *groups);
251 void crsetgroups_and_egid(struct ucred *cr, int ngrp, const gid_t *groups,
252 const gid_t default_egid);
253 bool cr_xids_subset(struct ucred *active_cred, struct ucred *obj_cred);
254
255 /*
256 * Returns whether gid designates a primary group in cred.
257 */
258 static inline bool
group_is_primary(const gid_t gid,const struct ucred * const cred)259 group_is_primary(const gid_t gid, const struct ucred *const cred)
260 {
261 return (gid == cred->cr_groups[0] || gid == cred->cr_rgid ||
262 gid == cred->cr_svgid);
263 }
264 bool group_is_supplementary(const gid_t gid, const struct ucred *const cred);
265 bool groupmember(gid_t gid, const struct ucred *cred);
266 bool realgroupmember(gid_t gid, const struct ucred *cred);
267
268 #else /* !_KERNEL */
269
270 __BEGIN_DECLS
271 int setcred(u_int flags, const struct setcred *wcred, size_t size);
272 __END_DECLS
273
274 #endif /* _KERNEL */
275
276 #endif /* !_SYS_UCRED_H_ */
277