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 #if defined(_KERNEL) || defined(_WANT_UCRED)
36 #include <sys/_lock.h>
37 #include <sys/_mutex.h>
38 #endif
39 #include <bsm/audit.h>
40
41 struct loginclass;
42
43 #define XU_NGROUPS 16
44
45 #if defined(_KERNEL) || defined(_WANT_UCRED)
46 /*
47 * Number of groups inlined in 'struct ucred'. It must stay reasonably low as
48 * it is also used by some functions to allocate an array of this size on the
49 * stack.
50 */
51 #define CRED_SMALLGROUPS_NB 16
52
53 /*
54 * Credentials.
55 *
56 * Please do not inspect cr_uid directly to determine superuserness. The
57 * priv(9) interface should be used to check for privilege.
58 *
59 * Lock reference:
60 * c - cr_mtx
61 *
62 * Unmarked fields are constant after creation.
63 *
64 * See "Credential management" comment in kern_prot.c for more information.
65 */
66 struct ucred {
67 struct mtx cr_mtx;
68 long cr_ref; /* (c) reference count */
69 u_int cr_users; /* (c) proc + thread using this cred */
70 u_int cr_flags; /* credential flags */
71 struct auditinfo_addr cr_audit; /* Audit properties. */
72 #define cr_startcopy cr_uid
73 uid_t cr_uid; /* effective user id */
74 uid_t cr_ruid; /* real user id */
75 uid_t cr_svuid; /* saved user id */
76 /*
77 * XXXOC: On the next ABI change, please move 'cr_ngroups' out of the
78 * copied area (crcopy() already copes with this change).
79 */
80 int cr_ngroups; /* number of groups */
81 gid_t cr_rgid; /* real group id */
82 gid_t cr_svgid; /* saved group id */
83 struct uidinfo *cr_uidinfo; /* per euid resource consumption */
84 struct uidinfo *cr_ruidinfo; /* per ruid resource consumption */
85 struct prison *cr_prison; /* jail(2) */
86 struct loginclass *cr_loginclass; /* login class */
87 void *cr_pspare2[2]; /* general use 2 */
88 #define cr_endcopy cr_label
89 struct label *cr_label; /* MAC label */
90 gid_t *cr_groups; /* groups */
91 int cr_agroups; /* Available groups */
92 /* storage for small groups */
93 gid_t cr_smallgroups[CRED_SMALLGROUPS_NB];
94 };
95 #define NOCRED ((struct ucred *)0) /* no credential available */
96 #define FSCRED ((struct ucred *)-1) /* filesystem credential */
97 #endif /* _KERNEL || _WANT_UCRED */
98
99 /*
100 * Flags for cr_flags.
101 */
102 #define CRED_FLAG_CAPMODE 0x00000001 /* In capability mode. */
103
104 /*
105 * This is the external representation of struct ucred.
106 */
107 struct xucred {
108 u_int cr_version; /* structure layout version */
109 uid_t cr_uid; /* effective user id */
110 short cr_ngroups; /* number of groups */
111 gid_t cr_groups[XU_NGROUPS]; /* groups */
112 union {
113 void *_cr_unused1; /* compatibility with old ucred */
114 pid_t cr_pid;
115 };
116 };
117 #define XUCRED_VERSION 0
118
119 /* This can be used for both ucred and xucred structures. */
120 #define cr_gid cr_groups[0]
121
122 #ifdef _KERNEL
123 struct proc;
124 struct thread;
125
126 struct credbatch {
127 struct ucred *cred;
128 int users;
129 int ref;
130 };
131
132 static inline void
credbatch_prep(struct credbatch * crb)133 credbatch_prep(struct credbatch *crb)
134 {
135 crb->cred = NULL;
136 crb->users = 0;
137 crb->ref = 0;
138 }
139 void credbatch_add(struct credbatch *crb, struct thread *td);
140
141 static inline void
credbatch_process(struct credbatch * crb __unused)142 credbatch_process(struct credbatch *crb __unused)
143 {
144
145 }
146
147 void credbatch_final(struct credbatch *crb);
148
149 void change_egid(struct ucred *newcred, gid_t egid);
150 void change_euid(struct ucred *newcred, struct uidinfo *euip);
151 void change_rgid(struct ucred *newcred, gid_t rgid);
152 void change_ruid(struct ucred *newcred, struct uidinfo *ruip);
153 void change_svgid(struct ucred *newcred, gid_t svgid);
154 void change_svuid(struct ucred *newcred, uid_t svuid);
155 void crcopy(struct ucred *dest, struct ucred *src);
156 struct ucred *crcopysafe(struct proc *p, struct ucred *cr);
157 struct ucred *crdup(struct ucred *cr);
158 void crextend(struct ucred *cr, int n);
159 void proc_set_cred(struct proc *p, struct ucred *cr);
160 void proc_unset_cred(struct proc *p);
161 void crfree(struct ucred *cr);
162 struct ucred *crcowsync(void);
163 struct ucred *crget(void);
164 struct ucred *crhold(struct ucred *cr);
165 struct ucred *crcowget(struct ucred *cr);
166 void crcowfree(struct thread *td);
167 void cru2x(struct ucred *cr, struct xucred *xcr);
168 void cru2xt(struct thread *td, struct xucred *xcr);
169 void crsetgroups(struct ucred *cr, int ngrp, const gid_t *groups);
170 void crsetgroups_fallback(struct ucred *cr, int ngrp, const gid_t *groups,
171 const gid_t fallback);
172
173 /*
174 * Returns whether gid designates a primary group in cred.
175 */
176 static inline bool
group_is_primary(const gid_t gid,const struct ucred * const cred)177 group_is_primary(const gid_t gid, const struct ucred *const cred)
178 {
179 return (gid == cred->cr_groups[0] || gid == cred->cr_rgid ||
180 gid == cred->cr_svgid);
181 }
182 bool group_is_supplementary(const gid_t gid, const struct ucred *const cred);
183 bool groupmember(gid_t gid, const struct ucred *cred);
184 bool realgroupmember(gid_t gid, const struct ucred *cred);
185 #endif /* _KERNEL */
186
187 #endif /* !_SYS_UCRED_H_ */
188