1 /* 2 * (The copyright below applies to ufs_access()) 3 * 4 * Copyright (c) 1982, 1986, 1989, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95 41 * $DragonFly: src/sys/kern/vfs_helper.c,v 1.3 2007/11/20 21:37:54 dillon Exp $ 42 */ 43 44 #include "opt_quota.h" 45 #include "opt_suiddir.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/fcntl.h> 51 #include <sys/stat.h> 52 #include <sys/mount.h> 53 #include <sys/unistd.h> 54 #include <sys/vnode.h> 55 #include <sys/file.h> /* XXX */ 56 #include <sys/jail.h> 57 58 /* 59 * vop_helper_access() 60 * 61 * Provide standard UNIX semanics for VOP_ACCESS, but without the quota 62 * code. This procedure was basically pulled out of UFS. 63 */ 64 int 65 vop_helper_access(struct vop_access_args *ap, uid_t ino_uid, gid_t ino_gid, 66 mode_t ino_mode, u_int32_t ino_flags) 67 { 68 struct vnode *vp = ap->a_vp; 69 struct ucred *cred = ap->a_cred; 70 mode_t mask, mode = ap->a_mode; 71 gid_t *gp; 72 int i; 73 #ifdef QUOTA 74 /*int error;*/ 75 #endif 76 77 /* 78 * Disallow write attempts on read-only filesystems; 79 * unless the file is a socket, fifo, or a block or 80 * character device resident on the filesystem. 81 */ 82 if (mode & VWRITE) { 83 switch (vp->v_type) { 84 case VDIR: 85 case VLNK: 86 case VREG: 87 case VDATABASE: 88 if (vp->v_mount->mnt_flag & MNT_RDONLY) 89 return (EROFS); 90 #ifdef QUOTA 91 /* check quota here XXX */ 92 #endif 93 break; 94 default: 95 break; 96 } 97 } 98 99 /* If immutable bit set, nobody gets to write it. */ 100 if ((mode & VWRITE) && (ino_flags & IMMUTABLE)) 101 return (EPERM); 102 103 /* Otherwise, user id 0 always gets access. */ 104 if (cred->cr_uid == 0) 105 return (0); 106 107 mask = 0; 108 109 /* Otherwise, check the owner. */ 110 if (cred->cr_uid == ino_uid) { 111 if (mode & VEXEC) 112 mask |= S_IXUSR; 113 if (mode & VREAD) 114 mask |= S_IRUSR; 115 if (mode & VWRITE) 116 mask |= S_IWUSR; 117 return ((ino_mode & mask) == mask ? 0 : EACCES); 118 } 119 120 /* Otherwise, check the groups. */ 121 for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++) 122 if (ino_gid == *gp) { 123 if (mode & VEXEC) 124 mask |= S_IXGRP; 125 if (mode & VREAD) 126 mask |= S_IRGRP; 127 if (mode & VWRITE) 128 mask |= S_IWGRP; 129 return ((ino_mode & mask) == mask ? 0 : EACCES); 130 } 131 132 /* Otherwise, check everyone else. */ 133 if (mode & VEXEC) 134 mask |= S_IXOTH; 135 if (mode & VREAD) 136 mask |= S_IROTH; 137 if (mode & VWRITE) 138 mask |= S_IWOTH; 139 return ((ino_mode & mask) == mask ? 0 : EACCES); 140 } 141 142 int 143 vop_helper_setattr_flags(u_int32_t *ino_flags, u_int32_t vaflags, 144 uid_t uid, struct ucred *cred) 145 { 146 int error; 147 148 /* 149 * If uid doesn't match only the super-user can change the flags 150 */ 151 if (cred->cr_uid != uid && 152 (error = suser_cred(cred, PRISON_ROOT))) { 153 return(error); 154 } 155 if (cred->cr_uid == 0 && 156 (!jailed(cred)|| jail_chflags_allowed)) { 157 if ((*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND)) && 158 securelevel > 0) 159 return (EPERM); 160 *ino_flags = vaflags; 161 } else { 162 if (*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND) || 163 (vaflags & UF_SETTABLE) != vaflags) 164 return (EPERM); 165 *ino_flags &= SF_SETTABLE; 166 *ino_flags |= vaflags & UF_SETTABLE; 167 } 168 return(0); 169 } 170 171 uid_t 172 vop_helper_create_uid(struct mount *mp, mode_t dmode, uid_t duid, 173 struct ucred *cred, mode_t *modep) 174 { 175 #ifdef SUIDDIR 176 if ((mount->mnt_flag & MNT_SUIDDIR) && (dmode & ISUID) && 177 duid != cred->cr_uid && duid) { 178 *modep &= ~07111; 179 return(duid); 180 } 181 #endif 182 return(cred->cr_uid); 183 } 184 185