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 * from: @(#)sysv_shm.c 7.15 (Berkeley) 5/13/91 41 * $Id: sysv_ipc.c,v 1.1 1993/11/14 13:22:58 cgd Exp $ 42 */ 43 44 /* 45 * IPC routines shared by some or all of the SYSV IPC system calls. 46 */ 47 48 #ifndef SYSVIPC 49 50 #ifdef SYSVSHM 51 #define SYSVIPC 52 #endif 53 54 #ifdef SYSVSEM 55 #define SYSVIPC 56 #endif 57 58 #ifdef SYSVMSG 59 #define SYSVIPC 60 #endif 61 62 #endif 63 64 #ifdef SYSVIPC 65 66 #include "param.h" 67 #include "systm.h" 68 #include "kernel.h" 69 #include "proc.h" 70 #include "ipc.h" 71 #include "shm.h" 72 73 /* 74 * Perform access checking. 75 */ 76 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 */ 104