1 /* $NetBSD: sysv_ipc.c,v 1.16 2005/12/07 06:14:13 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 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 NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.16 2005/12/07 06:14:13 thorpej Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/proc.h> 45 #include <sys/ipc.h> 46 #include <sys/systm.h> 47 #include <sys/mount.h> 48 #include <sys/vnode.h> 49 #include <sys/stat.h> 50 51 /* 52 * Check for ipc permission 53 */ 54 55 int 56 ipcperm(struct ucred *cred, struct ipc_perm *perm, int mode) 57 { 58 mode_t mask; 59 60 if (cred->cr_uid == 0) 61 return (0); 62 63 if (mode == IPC_M) { 64 if (cred->cr_uid == perm->uid || 65 cred->cr_uid == perm->cuid) 66 return (0); 67 return (EPERM); 68 } 69 70 mask = 0; 71 72 if (cred->cr_uid == perm->uid || 73 cred->cr_uid == perm->cuid) { 74 if (mode & IPC_R) 75 mask |= S_IRUSR; 76 if (mode & IPC_W) 77 mask |= S_IWUSR; 78 return ((perm->mode & mask) == mask ? 0 : EACCES); 79 } 80 81 if (cred->cr_gid == perm->gid || groupmember(perm->gid, cred) || 82 cred->cr_gid == perm->cgid || groupmember(perm->cgid, cred)) { 83 if (mode & IPC_R) 84 mask |= S_IRGRP; 85 if (mode & IPC_W) 86 mask |= S_IWGRP; 87 return ((perm->mode & mask) == mask ? 0 : EACCES); 88 } 89 90 if (mode & IPC_R) 91 mask |= S_IROTH; 92 if (mode & IPC_W) 93 mask |= S_IWOTH; 94 return ((perm->mode & mask) == mask ? 0 : EACCES); 95 } 96