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24fd64ab DG |
1 | /* |
2 | * Copyright (c) 1988 University of Utah. | |
3 | * Copyright (c) 1990 The Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * This code is derived from software contributed to Berkeley by | |
7 | * the Systems Programming Group of the University of Utah Computer | |
8 | * Science Department. Originally from University of Wisconsin. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * 3. All advertising materials mentioning features or use of this software | |
19 | * must display the following acknowledgement: | |
20 | * This product includes software developed by the University of | |
21 | * California, Berkeley and its contributors. | |
22 | * 4. Neither the name of the University nor the names of its contributors | |
23 | * may be used to endorse or promote products derived from this software | |
24 | * without specific prior written permission. | |
25 | * | |
26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
36 | * SUCH DAMAGE. | |
37 | * | |
38 | * from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$ | |
39 | * | |
40 | * @(#)sysv_shm.c 7.15 (Berkeley) 5/13/91 | |
41 | */ | |
42 | ||
43 | /* | |
44 | * IPC routines shared by some or all of the SYSV IPC system calls. | |
45 | */ | |
46 | ||
47 | #ifndef SYSVIPC | |
48 | ||
49 | #ifdef SYSVSHM | |
50 | #define SYSVIPC | |
51 | #endif | |
52 | ||
53 | #ifdef SYSVSEM | |
54 | #define SYSVIPC | |
55 | #endif | |
56 | ||
57 | #ifdef SYSVMSG | |
58 | #define SYSVIPC | |
59 | #endif | |
60 | ||
61 | #endif | |
62 | ||
63 | #ifdef SYSVIPC | |
64 | ||
65 | #include "param.h" | |
66 | #include "systm.h" | |
67 | #include "kernel.h" | |
68 | #include "proc.h" | |
69 | #include "ipc.h" | |
70 | #include "shm.h" | |
71 | ||
72 | /* | |
73 | * Perform access checking. | |
74 | */ | |
75 | ||
76 | int | |
77 | ipcaccess(ipc, mode, cred) | |
78 | register struct ipc_perm *ipc; | |
79 | int mode; | |
80 | register struct ucred *cred; | |
81 | { | |
82 | register int m; | |
83 | ||
84 | if (cred->cr_uid == 0) | |
85 | return(0); | |
86 | /* | |
87 | * Access check is based on only one of owner, group, public. | |
88 | * If not owner, then check group. | |
89 | * If not a member of the group, then check public access. | |
90 | */ | |
91 | mode &= 0700; | |
92 | m = ipc->mode; | |
93 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { | |
94 | m <<= 3; | |
95 | if (!groupmember(ipc->gid, cred) && | |
96 | !groupmember(ipc->cgid, cred)) | |
97 | m <<= 3; | |
98 | } | |
99 | if ((mode&m) == mode) | |
100 | return (0); | |
101 | return (EACCES); | |
102 | } | |
103 | #endif /* SYSVSHM */ |