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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 27 /* All Rights Reserved */ 28 29 /* 30 * Portions of this source code were derived from Berkeley 4.3 BSD 31 * under license from the Regents of the University of California. 32 */ 33 34 #pragma ident "%Z%%M% %I% %E% SMI" 35 36 #include <sys/param.h> 37 #include <sys/isa_defs.h> 38 #include <sys/types.h> 39 #include <sys/sysmacros.h> 40 #include <sys/cred_impl.h> 41 #include <sys/systm.h> 42 #include <sys/errno.h> 43 #include <sys/pathname.h> 44 #include <sys/vnode.h> 45 #include <sys/uio.h> 46 #include <sys/cmn_err.h> 47 #include <sys/debug.h> 48 #include <sys/file.h> 49 #include <fs/fs_subr.h> 50 #include <c2/audit.h> 51 52 /* 53 * Determine accessibility of file. 54 */ 55 56 #define E_OK 010 /* use effective ids */ 57 #define R_OK 004 58 #define W_OK 002 59 #define X_OK 001 60 61 static int 62 caccess(char *fname, int fmode, vnode_t *startvp) 63 { 64 vnode_t *vp; 65 cred_t *tmpcr; 66 int error; 67 int mode; 68 int eok; 69 cred_t *cr; 70 int estale_retry = 0; 71 72 if (fmode & ~(E_OK|R_OK|W_OK|X_OK)) 73 return (set_errno(EINVAL)); 74 75 mode = ((fmode & (R_OK|W_OK|X_OK)) << 6); 76 77 cr = CRED(); 78 79 /* OK to use effective uid/gid, i.e., no need to crdup(CRED())? */ 80 eok = (fmode & E_OK) || 81 (cr->cr_uid == cr->cr_ruid && cr->cr_gid == cr->cr_rgid); 82 83 if (eok) 84 tmpcr = cr; 85 else { 86 tmpcr = crdup(cr); 87 tmpcr->cr_uid = cr->cr_ruid; 88 tmpcr->cr_gid = cr->cr_rgid; 89 tmpcr->cr_ruid = cr->cr_uid; 90 tmpcr->cr_rgid = cr->cr_gid; 91 } 92 93 lookup: 94 if (error = lookupnameat(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp, 95 startvp)) { 96 if ((error == ESTALE) && fs_need_estale_retry(estale_retry++)) 97 goto lookup; 98 if (!eok) 99 crfree(tmpcr); 100 return (set_errno(error)); 101 } 102 103 if (mode) { 104 error = VOP_ACCESS(vp, mode, 0, tmpcr, NULL); 105 if (error) { 106 if ((error == ESTALE) && 107 fs_need_estale_retry(estale_retry++)) { 108 VN_RELE(vp); 109 goto lookup; 110 } 111 (void) set_errno(error); 112 } 113 } 114 115 if (!eok) 116 crfree(tmpcr); 117 VN_RELE(vp); 118 return (error); 119 } 120 121 int 122 access(char *fname, int fmode) 123 { 124 return (caccess(fname, fmode, NULL)); 125 } 126 127 int 128 accessat(int fd, char *fname, int fmode) 129 { 130 file_t *dirfp; 131 vnode_t *dirvp; 132 int error; 133 char startchar; 134 135 if (fd == AT_FDCWD && fname == NULL) 136 return (set_errno(EFAULT)); 137 138 if (fname != NULL) { 139 if (copyin(fname, &startchar, sizeof (char))) 140 return (set_errno(EFAULT)); 141 } else 142 startchar = '\0'; 143 144 if (fd == AT_FDCWD) { 145 dirvp = NULL; 146 } else { 147 if (startchar != '/') { 148 if ((dirfp = getf(fd)) == NULL) { 149 return (set_errno(EBADF)); 150 } 151 dirvp = dirfp->f_vnode; 152 VN_HOLD(dirvp); 153 releasef(fd); 154 } else { 155 dirvp = NULL; 156 } 157 } 158 159 if (audit_active) 160 audit_setfsat_path(1); 161 162 error = caccess(fname, fmode, dirvp); 163 if (dirvp != NULL) 164 VN_RELE(dirvp); 165 166 return (error); 167 } 168