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 1.5 2008/05/25 18:34:46 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/proc.h> 57 #include <sys/jail.h> 58 59 /* 60 * vop_helper_access() 61 * 62 * Provide standard UNIX semanics for VOP_ACCESS, but without the quota 63 * code. This procedure was basically pulled out of UFS. 64 */ 65 int 66 vop_helper_access(struct vop_access_args *ap, uid_t ino_uid, gid_t ino_gid, 67 mode_t ino_mode, u_int32_t ino_flags) 68 { 69 struct vnode *vp = ap->a_vp; 70 struct ucred *cred = ap->a_cred; 71 mode_t mask, mode = ap->a_mode; 72 gid_t *gp; 73 int i; 74 #ifdef QUOTA 75 /*int error;*/ 76 #endif 77 78 /* 79 * Disallow write attempts on read-only filesystems; 80 * unless the file is a socket, fifo, or a block or 81 * character device resident on the filesystem. 82 */ 83 if (mode & VWRITE) { 84 switch (vp->v_type) { 85 case VDIR: 86 case VLNK: 87 case VREG: 88 case VDATABASE: 89 if (vp->v_mount->mnt_flag & MNT_RDONLY) 90 return (EROFS); 91 #ifdef QUOTA 92 /* check quota here XXX */ 93 #endif 94 break; 95 default: 96 break; 97 } 98 } 99 100 /* If immutable bit set, nobody gets to write it. */ 101 if ((mode & VWRITE) && (ino_flags & IMMUTABLE)) 102 return (EPERM); 103 104 /* Otherwise, user id 0 always gets access. */ 105 if (cred->cr_uid == 0) 106 return (0); 107 108 mask = 0; 109 110 /* Otherwise, check the owner. */ 111 if (cred->cr_uid == ino_uid) { 112 if (mode & VEXEC) 113 mask |= S_IXUSR; 114 if (mode & VREAD) 115 mask |= S_IRUSR; 116 if (mode & VWRITE) 117 mask |= S_IWUSR; 118 return ((ino_mode & mask) == mask ? 0 : EACCES); 119 } 120 121 /* Otherwise, check the groups. */ 122 for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++) 123 if (ino_gid == *gp) { 124 if (mode & VEXEC) 125 mask |= S_IXGRP; 126 if (mode & VREAD) 127 mask |= S_IRGRP; 128 if (mode & VWRITE) 129 mask |= S_IWGRP; 130 return ((ino_mode & mask) == mask ? 0 : EACCES); 131 } 132 133 /* Otherwise, check everyone else. */ 134 if (mode & VEXEC) 135 mask |= S_IXOTH; 136 if (mode & VREAD) 137 mask |= S_IROTH; 138 if (mode & VWRITE) 139 mask |= S_IWOTH; 140 return ((ino_mode & mask) == mask ? 0 : EACCES); 141 } 142 143 int 144 vop_helper_setattr_flags(u_int32_t *ino_flags, u_int32_t vaflags, 145 uid_t uid, struct ucred *cred) 146 { 147 int error; 148 149 /* 150 * If uid doesn't match only the super-user can change the flags 151 */ 152 if (cred->cr_uid != uid && 153 (error = suser_cred(cred, PRISON_ROOT))) { 154 return(error); 155 } 156 if (cred->cr_uid == 0 && 157 (!jailed(cred)|| jail_chflags_allowed)) { 158 if ((*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND)) && 159 securelevel > 0) 160 return (EPERM); 161 *ino_flags = vaflags; 162 } else { 163 if (*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND) || 164 (vaflags & UF_SETTABLE) != vaflags) 165 return (EPERM); 166 *ino_flags &= SF_SETTABLE; 167 *ino_flags |= vaflags & UF_SETTABLE; 168 } 169 return(0); 170 } 171 172 /* 173 * This helper function may be used by VFSs to implement UNIX initial 174 * ownership semantics when creating new objects inside directories. 175 */ 176 uid_t 177 vop_helper_create_uid(struct mount *mp, mode_t dmode, uid_t duid, 178 struct ucred *cred, mode_t *modep) 179 { 180 #ifdef SUIDDIR 181 if ((mp->mnt_flag & MNT_SUIDDIR) && (dmode & S_ISUID) && 182 duid != cred->cr_uid && duid) { 183 *modep &= ~07111; 184 return(duid); 185 } 186 #endif 187 return(cred->cr_uid); 188 } 189 190 /* 191 * This helper may be used by VFSs to implement unix chmod semantics. 192 */ 193 int 194 vop_helper_chmod(struct vnode *vp, mode_t new_mode, struct ucred *cred, 195 uid_t cur_uid, gid_t cur_gid, mode_t *cur_modep) 196 { 197 int error; 198 199 if (cred->cr_uid != cur_uid) { 200 error = suser_cred(cred, PRISON_ROOT); 201 if (error) 202 return (error); 203 } 204 if (cred->cr_uid) { 205 if (vp->v_type != VDIR && (*cur_modep & S_ISTXT)) 206 return (EFTYPE); 207 if (!groupmember(cur_gid, cred) && (*cur_modep & S_ISGID)) 208 return (EPERM); 209 } 210 *cur_modep &= ~ALLPERMS; 211 *cur_modep |= new_mode & ALLPERMS; 212 return(0); 213 } 214 215 /* 216 * This helper may be used by VFSs to implement unix chown semantics. 217 */ 218 int 219 vop_helper_chown(struct vnode *vp, uid_t new_uid, gid_t new_gid, 220 struct ucred *cred, 221 uid_t *cur_uidp, gid_t *cur_gidp, mode_t *cur_modep) 222 { 223 gid_t ogid; 224 uid_t ouid; 225 int error; 226 227 if (new_uid == (uid_t)VNOVAL) 228 new_uid = *cur_uidp; 229 if (new_gid == (gid_t)VNOVAL) 230 new_gid = *cur_gidp; 231 232 /* 233 * If we don't own the file, are trying to change the owner 234 * of the file, or are not a member of the target group, 235 * the caller must be superuser or the call fails. 236 */ 237 if ((cred->cr_uid != *cur_uidp || new_uid != *cur_uidp || 238 (new_gid != *cur_gidp && !(cred->cr_gid == new_gid || 239 groupmember(new_gid, cred)))) && 240 (error = suser_cred(cred, PRISON_ROOT))) { 241 return (error); 242 } 243 ogid = *cur_gidp; 244 ouid = *cur_uidp; 245 /* XXX QUOTA CODE */ 246 *cur_uidp = new_uid; 247 *cur_gidp = new_gid; 248 /* XXX QUOTA CODE */ 249 if (cred->cr_uid != 0 && (ouid != new_uid || ogid != new_gid)) 250 *cur_modep &= ~(S_ISUID | S_ISGID); 251 return(0); 252 } 253 254