1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 /* 31 * Portions of this source code were derived from Berkeley 4.3 BSD 32 * under license from the Regents of the University of California. 33 */ 34 35 #pragma ident "%Z%%M% %I% %E% SMI" 36 37 #include <sys/param.h> 38 #include <sys/isa_defs.h> 39 #include <sys/types.h> 40 #include <sys/sysmacros.h> 41 #include <sys/cred_impl.h> 42 #include <sys/systm.h> 43 #include <sys/errno.h> 44 #include <sys/pathname.h> 45 #include <sys/vnode.h> 46 #include <sys/uio.h> 47 #include <sys/cmn_err.h> 48 #include <sys/debug.h> 49 50 /* 51 * Determine accessibility of file. 52 */ 53 54 #define E_OK 010 /* use effective ids */ 55 #define R_OK 004 56 #define W_OK 002 57 #define X_OK 001 58 59 int 60 access(char *fname, int fmode) 61 { 62 vnode_t *vp; 63 cred_t *tmpcr; 64 int error; 65 int mode; 66 int eok; 67 cred_t *cr; 68 69 if (fmode & ~(E_OK|R_OK|W_OK|X_OK)) 70 return (set_errno(EINVAL)); 71 72 mode = ((fmode & (R_OK|W_OK|X_OK)) << 6); 73 74 cr = CRED(); 75 76 /* OK to use effective uid/gid, i.e., no need to crdup(CRED())? */ 77 eok = (fmode & E_OK) || 78 (cr->cr_uid == cr->cr_ruid && cr->cr_gid == cr->cr_rgid); 79 80 if (eok) 81 tmpcr = cr; 82 else { 83 tmpcr = crdup(cr); 84 tmpcr->cr_uid = cr->cr_ruid; 85 tmpcr->cr_gid = cr->cr_rgid; 86 tmpcr->cr_ruid = cr->cr_uid; 87 tmpcr->cr_rgid = cr->cr_gid; 88 } 89 90 lookup: 91 if (error = lookupname(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp)) { 92 if (error == ESTALE) 93 goto lookup; 94 if (!eok) 95 crfree(tmpcr); 96 return (set_errno(error)); 97 } 98 99 if (mode) { 100 error = VOP_ACCESS(vp, mode, 0, tmpcr); 101 if (error) { 102 if (error == ESTALE) { 103 VN_RELE(vp); 104 goto lookup; 105 } 106 (void) set_errno(error); 107 } 108 } 109 110 if (!eok) 111 crfree(tmpcr); 112 VN_RELE(vp); 113 return (error); 114 } 115