| 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 */ |