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 * @(#)ucred.h 8.4 (Berkeley) 1/9/95
32 */
33
34 #ifndef _SYS_UCRED_H_
35 #define _SYS_UCRED_H_
36
37 #include <sys/types.h>
38 #if defined(_KERNEL) || defined(_WANT_UCRED)
39 #include <sys/_lock.h>
40 #include <sys/_mutex.h>
41 #endif
42 #include <bsm/audit.h>
43
44 #if defined(_KERNEL) || defined(_WANT_UCRED)
45 struct loginclass;
46
47 /*
48 * Flags for cr_flags.
49 */
50 #define CRED_FLAG_CAPMODE 0x00000001 /* In capability mode. */
51
52 /*
53 * Number of groups inlined in 'struct ucred'. It must stay reasonably low as
54 * it is also used by some functions to allocate an array of this size on the
55 * stack.
56 */
57 #define CRED_SMALLGROUPS_NB 16
58
59 struct label;
60 struct prison;
61 struct uidinfo;
62
63 /*
64 * Credentials.
65 *
66 * Please do not inspect cr_uid directly to determine superuserness. The
67 * priv(9) interface should be used to check for privilege.
68 *
69 * Lock reference:
70 * c - cr_mtx
71 *
72 * Unmarked fields are constant after creation.
73 *
74 * See "Credential management" comment in kern_prot.c for more information.
75 */
76 struct ucred {
77 struct mtx cr_mtx;
78 long cr_ref; /* (c) reference count */
79 u_int cr_users; /* (c) proc + thread using this cred */
80 u_int cr_flags; /* credential flags */
81 struct auditinfo_addr cr_audit; /* Audit properties. */
82 #define cr_startcopy cr_uid
83 uid_t cr_uid; /* effective user id */
84 uid_t cr_ruid; /* real user id */
85 uid_t cr_svuid; /* saved user id */
86 /*
87 * XXXOC: On the next ABI change, please move 'cr_ngroups' out of the
88 * copied area (crcopy() already copes with this change).
89 */
90 int cr_ngroups; /* number of groups */
91 gid_t cr_rgid; /* real group id */
92 gid_t cr_svgid; /* saved group id */
93 struct uidinfo *cr_uidinfo; /* per euid resource consumption */
94 struct uidinfo *cr_ruidinfo; /* per ruid resource consumption */
95 struct prison *cr_prison; /* jail(2) */
96 struct loginclass *cr_loginclass; /* login class */
97 void *cr_pspare2[2]; /* general use 2 */
98 #define cr_endcopy cr_label
99 struct label *cr_label; /* MAC label */
100 gid_t *cr_groups; /* groups */
101 int cr_agroups; /* Available groups */
102 /* storage for small groups */
103 gid_t cr_smallgroups[CRED_SMALLGROUPS_NB];
104 };
105 #define NOCRED ((struct ucred *)0) /* no credential available */
106 #define FSCRED ((struct ucred *)-1) /* filesystem credential */
107 #endif /* _KERNEL || _WANT_UCRED */
108
109 #define XU_NGROUPS 16
110
111 /*
112 * This is the external representation of struct ucred.
113 */
114 struct xucred {
115 u_int cr_version; /* structure layout version */
116 uid_t cr_uid; /* effective user id */
117 short cr_ngroups; /* number of groups */
118 gid_t cr_groups[XU_NGROUPS]; /* groups */
119 union {
120 void *_cr_unused1; /* compatibility with old ucred */
121 pid_t cr_pid;
122 };
123 };
124 #define XUCRED_VERSION 0
125
126 /* This can be used for both ucred and xucred structures. */
127 #define cr_gid cr_groups[0]
128
129 struct mac;
130 /*
131 * Structure to pass as an argument to the setcred() system call.
132 */
133 struct setcred {
134 uid_t sc_uid; /* effective user id */
135 uid_t sc_ruid; /* real user id */
136 uid_t sc_svuid; /* saved user id */
137 gid_t sc_gid; /* effective group id */
138 gid_t sc_rgid; /* real group id */
139 gid_t sc_svgid; /* saved group id */
140 u_int sc_pad; /* see 32-bit compat structure */
141 u_int sc_supp_groups_nb; /* number of supplementary groups */
142 gid_t *sc_supp_groups; /* supplementary groups */
143 struct mac *sc_label; /* MAC label */
144 };
145 /*
146 * Initializer for 'struct setcred' variables.
147 */
148 #define SETCRED_INITIALIZER { -1, -1, -1, -1, -1, -1, 0, 0, NULL, NULL }
149
150 /*
151 * Flags to setcred().
152 */
153 #define SETCREDF_UID (1u << 0)
154 #define SETCREDF_RUID (1u << 1)
155 #define SETCREDF_SVUID (1u << 2)
156 #define SETCREDF_GID (1u << 3)
157 #define SETCREDF_RGID (1u << 4)
158 #define SETCREDF_SVGID (1u << 5)
159 #define SETCREDF_SUPP_GROUPS (1u << 6)
160 #define SETCREDF_MAC_LABEL (1u << 7)
161
162 #ifdef _KERNEL
163 /*
164 * Masks of the currently valid flags to setcred().
165 *
166 * Please consider reserving some of the high bits in the 'flags' argument for
167 * versioning when almost all of them are in use.
168 */
169 #define SETCREDF_MASK (SETCREDF_UID | SETCREDF_RUID | SETCREDF_SVUID | \
170 SETCREDF_GID | SETCREDF_RGID | SETCREDF_SVGID | SETCREDF_SUPP_GROUPS | \
171 SETCREDF_MAC_LABEL)
172
173 struct setcred32 {
174 #define setcred32_copy_start sc_uid
175 uid_t sc_uid;
176 uid_t sc_ruid;
177 uid_t sc_svuid;
178 gid_t sc_gid;
179 gid_t sc_rgid;
180 gid_t sc_svgid;
181 u_int sc_pad;
182 u_int sc_supp_groups_nb;
183 #define setcred32_copy_end sc_supp_groups
184 uint32_t sc_supp_groups; /* gid_t [*] */
185 uint32_t sc_label; /* struct mac32 [*] */
186 };
187
188 struct thread;
189
190 /* Common native and 32-bit compatibility entry point. */
191 int user_setcred(struct thread *td, const u_int flags,
192 const void *const uwcred, const size_t size, bool is_32bit);
193
194 struct proc;
195
196 struct credbatch {
197 struct ucred *cred;
198 u_int users;
199 long ref;
200 };
201
202 static inline void
credbatch_prep(struct credbatch * crb)203 credbatch_prep(struct credbatch *crb)
204 {
205 crb->cred = NULL;
206 crb->users = 0;
207 crb->ref = 0;
208 }
209 void credbatch_add(struct credbatch *crb, struct thread *td);
210
211 static inline void
credbatch_process(struct credbatch * crb __unused)212 credbatch_process(struct credbatch *crb __unused)
213 {
214
215 }
216
217 void credbatch_final(struct credbatch *crb);
218
219 void change_egid(struct ucred *newcred, gid_t egid);
220 void change_euid(struct ucred *newcred, struct uidinfo *euip);
221 void change_rgid(struct ucred *newcred, gid_t rgid);
222 void change_ruid(struct ucred *newcred, struct uidinfo *ruip);
223 void change_svgid(struct ucred *newcred, gid_t svgid);
224 void change_svuid(struct ucred *newcred, uid_t svuid);
225 void crcopy(struct ucred *dest, struct ucred *src);
226 struct ucred *crcopysafe(struct proc *p, struct ucred *cr);
227 struct ucred *crdup(struct ucred *cr);
228 void crextend(struct ucred *cr, int n);
229 void proc_set_cred(struct proc *p, struct ucred *newcred);
230 bool proc_set_cred_enforce_proc_lim(struct proc *p, struct ucred *newcred);
231 void proc_unset_cred(struct proc *p, bool decrement_proc_count);
232 void crfree(struct ucred *cr);
233 struct ucred *crcowsync(void);
234 struct ucred *crget(void);
235 struct ucred *crhold(struct ucred *cr);
236 struct ucred *crcowget(struct ucred *cr);
237 void crcowfree(struct thread *td);
238 void cru2x(struct ucred *cr, struct xucred *xcr);
239 void cru2xt(struct thread *td, struct xucred *xcr);
240 void crsetgroups(struct ucred *cr, int ngrp, const gid_t *groups);
241 void crsetgroups_fallback(struct ucred *cr, int ngrp, const gid_t *groups,
242 const gid_t fallback);
243
244 /*
245 * Returns whether gid designates a primary group in cred.
246 */
247 static inline bool
group_is_primary(const gid_t gid,const struct ucred * const cred)248 group_is_primary(const gid_t gid, const struct ucred *const cred)
249 {
250 return (gid == cred->cr_groups[0] || gid == cred->cr_rgid ||
251 gid == cred->cr_svgid);
252 }
253 bool group_is_supplementary(const gid_t gid, const struct ucred *const cred);
254 bool groupmember(gid_t gid, const struct ucred *cred);
255 bool realgroupmember(gid_t gid, const struct ucred *cred);
256
257 #else /* !_KERNEL */
258
259 __BEGIN_DECLS
260 int setcred(u_int flags, const struct setcred *wcred, size_t size);
261 __END_DECLS
262
263 #endif /* _KERNEL */
264
265 #endif /* !_SYS_UCRED_H_ */
266