1 /* $NetBSD: sysv_ipc.c,v 1.12 1997/05/08 17:16:15 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Charles M. Hannum. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Charles M. Hannum. 17 * 4. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/proc.h> 35 #include <sys/ipc.h> 36 #include <sys/systm.h> 37 #include <sys/mount.h> 38 #include <sys/vnode.h> 39 #include <sys/stat.h> 40 41 /* 42 * Check for ipc permission 43 */ 44 45 int 46 ipcperm(cred, perm, mode) 47 struct ucred *cred; 48 struct ipc_perm *perm; 49 int mode; 50 { 51 mode_t mask; 52 53 if (cred->cr_uid == 0) 54 return (0); 55 56 if (mode == IPC_M) { 57 if (cred->cr_uid == perm->uid || 58 cred->cr_uid == perm->cuid) 59 return (0); 60 return (EPERM); 61 } 62 63 mask = 0; 64 65 if (cred->cr_uid == perm->uid || 66 cred->cr_uid == perm->cuid) { 67 if (mode & IPC_R) 68 mask |= S_IRUSR; 69 if (mode & IPC_W) 70 mask |= S_IWUSR; 71 return ((perm->mode & mask) == mask ? 0 : EACCES); 72 } 73 74 if (cred->cr_gid == perm->gid || groupmember(perm->gid, cred) || 75 cred->cr_gid == perm->cgid || groupmember(perm->cgid, cred)) { 76 if (mode & IPC_R) 77 mask |= S_IRGRP; 78 if (mode & IPC_W) 79 mask |= S_IWGRP; 80 return ((perm->mode & mask) == mask ? 0 : EACCES); 81 } 82 83 if (mode & IPC_R) 84 mask |= S_IROTH; 85 if (mode & IPC_W) 86 mask |= S_IWOTH; 87 return ((perm->mode & mask) == mask ? 0 : EACCES); 88 } 89