kernel/syscall/acl.c

   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.h>
  41 #include <sys/systm.h>
  42 #include <sys/errno.h>
  43 #include <sys/fcntl.h>
  44 #include <sys/pathname.h>
  45 #include <sys/vfs.h>
  46 #include <sys/vnode.h>
  47 #include <sys/file.h>
  48 #include <sys/mode.h>
  49 #include <sys/uio.h>
  50 #include <sys/kmem.h>
  51 #include <sys/filio.h>
  52 #include <sys/acl.h>
  53 #include <sys/cmn_err.h>
  54 #include <acl/acl_common.h>
  55
  56 #include <sys/unistd.h>
  57 #include <sys/debug.h>
  58 #include <sys/fs_subr.h>
  59
  60 static int cacl(int cmd, int nentries, void *aclbufp,
  61     vnode_t *vp, int *rv);
  62
  63 /*
  64  * Get/Set ACL of a file.
  65  */
  66 int
  67 acl(const char *fname, int cmd, int nentries, void *aclbufp)
  68 {
  69         struct vnode *vp;
  70         int error;
  71         int rv = 0;
  72         int estale_retry = 0;
  73
  74         /* Sanity check arguments */
  75         if (fname == NULL)
  76                 return (set_errno(EINVAL));
  77 lookup:
  78         error = lookupname((char *)fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp);
  79         if (error) {
  80                 if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
  81                         goto lookup;
  82                 return (set_errno(error));
  83         }
  84
  85         error = cacl(cmd, nentries, aclbufp, vp, &rv);
  86         VN_RELE(vp);
  87         if (error) {
  88                 if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
  89                         goto lookup;
  90                 return (set_errno(error));
  91         }
  92         return (rv);
  93 }
  94
  95 /*
  96  * Get/Set ACL of a file with facl system call.
  97  */
  98 int
  99 facl(int fdes, int cmd, int nentries, void *aclbufp)
 100 {
 101         file_t *fp;
 102         int error;
 103         int rv = 0;
 104
 105         if ((fp = getf(fdes)) == NULL)
 106                 return (set_errno(EBADF));
 107         if (fp->f_flag & FREVOKED) {
 108                 releasef(fdes);
 109                 return (set_errno(EBADF));
 110         }
 111
 112         error = cacl(cmd, nentries, aclbufp, fp->f_vnode, &rv);
 113         releasef(fdes);
 114
 115         if (error)
 116                 return (set_errno(error));
 117         return (rv);
 118 }
 119
 120
 121 /*
 122  * Common code for acl() and facl().
 123  */
 124 static int
 125 cacl(int cmd, int nentries, void *aclbufp, vnode_t *vp, int *rv)
 126 {
 127         int             error;
 128         int             aclbsize;       /* size of acl list in bytes */
 129         int             dfaclbsize;     /* size of default acl list in bytes */
 130         int             numacls;
 131         caddr_t         uaddrp;
 132         aclent_t        *aclp, *aaclp;
 133         vsecattr_t      vsecattr;
 134         size_t          entry_size;
 135
 136         ASSERT(vp);
 137
 138         bzero(&vsecattr, sizeof (vsecattr_t));
 139
 140         switch (cmd) {
 141
 142         case ACE_GETACLCNT:
 143         case GETACLCNT:
 144                 if (cmd == GETACLCNT) {
 145                         entry_size = sizeof (aclent_t);
 146                         vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
 147                 } else {
 148                         entry_size = sizeof (ace_t);
 149                         vsecattr.vsa_mask = VSA_ACECNT;
 150                 }
 151                 if (error = fop_getsecattr(vp, &vsecattr, 0, CRED(), NULL))
 152                         return (error);
 153                 *rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
 154                 if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
 155                         kmem_free(vsecattr.vsa_aclentp,
 156                             vsecattr.vsa_aclcnt * entry_size);
 157                 }
 158                 if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
 159                         kmem_free(vsecattr.vsa_dfaclentp,
 160                             vsecattr.vsa_dfaclcnt * entry_size);
 161                 }
 162                 break;
 163         case GETACL:
 164                 /*
 165                  * Minimum ACL size is three entries so might as well
 166                  * bail out here.
 167                  */
 168                 if (nentries < 3)
 169                         return (EINVAL);
 170                 /*
 171                  * NULL output buffer is also a pretty easy bail out.
 172                  */
 173                 if (aclbufp == NULL)
 174                         return (EFAULT);
 175                 vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
 176                     VSA_DFACLCNT;
 177                 if (error = fop_getsecattr(vp, &vsecattr, 0, CRED(), NULL))
 178                         return (error);
 179                 /* Check user's buffer is big enough */
 180                 numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
 181                 aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
 182                 dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
 183                 if (numacls > nentries) {
 184                         error = ENOSPC;
 185                         goto errout;
 186                 }
 187                 /* Sort the acl & default acl lists */
 188                 if (vsecattr.vsa_aclcnt > 1)
 189                         ksort((caddr_t)vsecattr.vsa_aclentp,
 190                             vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
 191                 if (vsecattr.vsa_dfaclcnt > 1)
 192                         ksort((caddr_t)vsecattr.vsa_dfaclentp,
 193                             vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
 194                 /* Copy out acl's */
 195                 uaddrp = (caddr_t)aclbufp;
 196                 if (aclbsize > 0) {     /* bug #1262490 */
 197                         if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
 198                                 error = EFAULT;
 199                                 goto errout;
 200                         }
 201                 }
 202                 /* Copy out default acl's */
 203                 if (dfaclbsize > 0) {
 204                         uaddrp += aclbsize;
 205                         if (copyout(vsecattr.vsa_dfaclentp,
 206                             uaddrp, dfaclbsize)) {
 207                                 error = EFAULT;
 208                                 goto errout;
 209                         }
 210                 }
 211                 *rv = numacls;
 212                 if (vsecattr.vsa_aclcnt) {
 213                         kmem_free(vsecattr.vsa_aclentp,
 214                             vsecattr.vsa_aclcnt * sizeof (aclent_t));
 215                 }
 216                 if (vsecattr.vsa_dfaclcnt) {
 217                         kmem_free(vsecattr.vsa_dfaclentp,
 218                             vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
 219                 }
 220                 break;
 221
 222         case ACE_GETACL:
 223                 if (aclbufp == NULL)
 224                         return (EFAULT);
 225
 226                 vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
 227                 if (error = fop_getsecattr(vp, &vsecattr, 0, CRED(), NULL))
 228                         return (error);
 229
 230                 aclbsize = vsecattr.vsa_aclcnt * sizeof (ace_t);
 231                 if (vsecattr.vsa_aclcnt > nentries) {
 232                         error = ENOSPC;
 233                         goto errout;
 234                 }
 235
 236                 if (aclbsize > 0) {
 237                         if ((error = copyout(vsecattr.vsa_aclentp,
 238                             aclbufp, aclbsize)) != 0) {
 239                                 goto errout;
 240                         }
 241                 }
 242
 243                 *rv = vsecattr.vsa_aclcnt;
 244                 if (vsecattr.vsa_aclcnt) {
 245                         kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);
 246                 }
 247                 break;
 248
 249         case SETACL:
 250                 /*
 251                  * Minimum ACL size is three entries so might as well
 252                  * bail out here.  Also limit request size to prevent user
 253                  * from allocating too much kernel memory.  Maximum size
 254                  * is MAX_ACL_ENTRIES for the ACL part and MAX_ACL_ENTRIES
 255                  * for the default ACL part. (bug 4058667)
 256                  */
 257                 if (nentries < 3 || nentries > (MAX_ACL_ENTRIES * 2))
 258                         return (EINVAL);
 259                 /*
 260                  * NULL output buffer is also an easy bail out.
 261                  */
 262                 if (aclbufp == NULL)
 263                         return (EFAULT);
 264                 vsecattr.vsa_mask = VSA_ACL;
 265                 aclbsize = nentries * sizeof (aclent_t);
 266                 vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
 267                 aaclp = vsecattr.vsa_aclentp;
 268                 vsecattr.vsa_aclcnt = nentries;
 269                 uaddrp = (caddr_t)aclbufp;
 270                 if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
 271                         kmem_free(aaclp, aclbsize);
 272                         return (EFAULT);
 273                 }
 274                 /* Sort the acl list */
 275                 ksort((caddr_t)vsecattr.vsa_aclentp,
 276                     vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
 277
 278                 /* Break into acl and default acl lists */
 279                 for (numacls = 0, aclp = vsecattr.vsa_aclentp;
 280                     numacls < vsecattr.vsa_aclcnt;
 281                     aclp++, numacls++) {
 282                         if (aclp->a_type & ACL_DEFAULT)
 283                                 break;
 284                 }
 285
 286                 /* Find where defaults start (if any) */
 287                 if (numacls < vsecattr.vsa_aclcnt) {
 288                         vsecattr.vsa_mask |= VSA_DFACL;
 289                         vsecattr.vsa_dfaclcnt = nentries - numacls;
 290                         vsecattr.vsa_dfaclentp = aclp;
 291                         vsecattr.vsa_aclcnt = numacls;
 292                 }
 293                 /* Adjust if they're all defaults */
 294                 if (vsecattr.vsa_aclcnt == 0) {
 295                         vsecattr.vsa_mask &= ~VSA_ACL;
 296                         vsecattr.vsa_aclentp = NULL;
 297                 }
 298                 /* Only directories can have defaults */
 299                 if (vsecattr.vsa_dfaclcnt && vp->v_type != VDIR) {
 300                         kmem_free(aaclp, aclbsize);
 301                         return (ENOTDIR);
 302                 }
 303                 (void) fop_rwlock(vp, V_WRITELOCK_TRUE, NULL);
 304                 if (error = fop_setsecattr(vp, &vsecattr, 0, CRED(), NULL)) {
 305                         kmem_free(aaclp, aclbsize);
 306                         fop_rwunlock(vp, V_WRITELOCK_TRUE, NULL);
 307                         return (error);
 308                 }
 309
 310                 /*
 311                  * Should return 0 upon success according to the man page
 312                  * and SVR4 semantics. (Bug #1214399: SETACL returns wrong rc)
 313                  */
 314                 *rv = 0;
 315                 kmem_free(aaclp, aclbsize);
 316                 fop_rwunlock(vp, V_WRITELOCK_TRUE, NULL);
 317                 break;
 318
 319         case ACE_SETACL:
 320                 if (nentries < 1 || nentries > MAX_ACL_ENTRIES)
 321                         return (EINVAL);
 322
 323                 if (aclbufp == NULL)
 324                         return (EFAULT);
 325
 326                 vsecattr.vsa_mask = VSA_ACE;
 327                 aclbsize = nentries * sizeof (ace_t);
 328                 vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
 329                 aaclp = vsecattr.vsa_aclentp;
 330                 vsecattr.vsa_aclcnt = nentries;
 331                 vsecattr.vsa_aclentsz = aclbsize;
 332                 uaddrp = (caddr_t)aclbufp;
 333                 if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
 334                         kmem_free(aaclp, aclbsize);
 335                         return (EFAULT);
 336                 }
 337                 (void) fop_rwlock(vp, V_WRITELOCK_TRUE, NULL);
 338                 if (error = fop_setsecattr(vp, &vsecattr, 0, CRED(), NULL)) {
 339                         kmem_free(aaclp, aclbsize);
 340                         fop_rwunlock(vp, V_WRITELOCK_TRUE, NULL);
 341                         return (error);
 342                 }
 343                 *rv = 0;
 344                 kmem_free(aaclp, aclbsize);
 345                 fop_rwunlock(vp, V_WRITELOCK_TRUE, NULL);
 346                 break;
 347
 348         default:
 349                 return (EINVAL);
 350         }
 351
 352         return (0);
 353
 354 errout:
 355         if (aclbsize && vsecattr.vsa_aclentp)
 356                 kmem_free(vsecattr.vsa_aclentp, aclbsize);
 357         if (dfaclbsize && vsecattr.vsa_dfaclentp)
 358                 kmem_free(vsecattr.vsa_dfaclentp, dfaclbsize);
 359         return (error);
 360 }