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 2009 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 #include <sys/param.h> 35 #include <sys/isa_defs.h> 36 #include <sys/types.h> 37 #include <sys/sysmacros.h> 38 #include <sys/cred_impl.h> 39 #include <sys/systm.h> 40 #include <sys/errno.h> 41 #include <sys/pathname.h> 42 #include <sys/vnode.h> 43 #include <sys/uio.h> 44 #include <sys/cmn_err.h> 45 #include <sys/debug.h> 46 #include <sys/file.h> 47 #include <fs/fs_subr.h> 48 #include <c2/audit.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 static int 60 caccess(char *fname, int fmode, vnode_t *startvp) 61 { 62 vnode_t *vp; 63 cred_t *tmpcr; 64 int error; 65 int mode; 66 int eok; 67 cred_t *cr; 68 int estale_retry = 0; 69 70 if (fmode & ~(E_OK|R_OK|W_OK|X_OK)) 71 return (set_errno(EINVAL)); 72 73 mode = ((fmode & (R_OK|W_OK|X_OK)) << 6); 74 75 cr = CRED(); 76 77 /* OK to use effective uid/gid, i.e., no need to crdup(CRED())? */ 78 eok = (fmode & E_OK) || 79 (cr->cr_uid == cr->cr_ruid && cr->cr_gid == cr->cr_rgid); 80 81 if (eok) 82 tmpcr = cr; 83 else { 84 tmpcr = crdup(cr); 85 tmpcr->cr_uid = cr->cr_ruid; 86 tmpcr->cr_gid = cr->cr_rgid; 87 tmpcr->cr_ruid = cr->cr_uid; 88 tmpcr->cr_rgid = cr->cr_gid; 89 } 90 91 lookup: 92 if (error = lookupnameatcred(fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp, 93 startvp, tmpcr)) { 94 if ((error == ESTALE) && fs_need_estale_retry(estale_retry++)) 95 goto lookup; 96 if (!eok) 97 crfree(tmpcr); 98 return (set_errno(error)); 99 } 100 101 if (mode) { 102 error = VOP_ACCESS(vp, mode, 0, tmpcr, NULL); 103 if (error) { 104 if ((error == ESTALE) && 105 fs_need_estale_retry(estale_retry++)) { 106 VN_RELE(vp); 107 goto lookup; 108 } 109 (void) set_errno(error); 110 } 111 } 112 113 if (!eok) 114 crfree(tmpcr); 115 VN_RELE(vp); 116 return (error); 117 } 118 119 int 120 access(char *fname, int fmode) 121 { 122 return (caccess(fname, fmode, NULL)); 123 } 124 125 int 126 accessat(int fd, char *fname, int fmode) 127 { 128 file_t *dirfp; 129 vnode_t *dirvp; 130 int error; 131 char startchar; 132 133 if (fd == AT_FDCWD && fname == NULL) 134 return (set_errno(EFAULT)); 135 136 if (fname != NULL) { 137 if (copyin(fname, &startchar, sizeof (char))) 138 return (set_errno(EFAULT)); 139 } else 140 startchar = '\0'; 141 142 if (fd == AT_FDCWD) { 143 dirvp = NULL; 144 } else { 145 if (startchar != '/') { 146 if ((dirfp = getf(fd)) == NULL) { 147 return (set_errno(EBADF)); 148 } 149 dirvp = dirfp->f_vnode; 150 VN_HOLD(dirvp); 151 releasef(fd); 152 } else { 153 dirvp = NULL; 154 } 155 } 156 157 if (audit_active) 158 audit_setfsat_path(1); 159 160 error = caccess(fname, fmode, dirvp); 161 if (dirvp != NULL) 162 VN_RELE(dirvp); 163 164 return (error); 165 } 166