fs/cifs/cifsacl.c

   1 /*
   2  *   fs/cifs/cifsacl.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2007
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   Contains the routines for mapping CIFS/NTFS ACLs
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include <linux/fs.h>
  25 #include "cifspdu.h"
  26 #include "cifsglob.h"
  27 #include "cifsacl.h"
  28 #include "cifsproto.h"
  29 #include "cifs_debug.h"
  30
  31
  32 #ifdef CONFIG_CIFS_EXPERIMENTAL
  33
  34 static struct cifs_wksid wksidarr[NUM_WK_SIDS] = {
  35         {{1, 0, {0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0} }, "null user"},
  36         {{1, 1, {0, 0, 0, 0, 0, 1}, {0, 0, 0, 0, 0} }, "nobody"},
  37         {{1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11), 0, 0, 0, 0} }, "net-users"},
  38         {{1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(18), 0, 0, 0, 0} }, "sys"},
  39         {{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(544), 0, 0, 0} }, "root"},
  40         {{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(545), 0, 0, 0} }, "users"},
  41         {{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(546), 0, 0, 0} }, "guest"}
  42 };
  43
  44
  45 /* security id for everyone */
  46 static const struct cifs_sid sid_everyone =
  47                 {1, 1, {0, 0, 0, 0, 0, 0}, {} };
  48 /* group users */
  49 static const struct cifs_sid sid_user =
  50                 {1, 2 , {0, 0, 0, 0, 0, 5}, {} };
  51
  52
  53 int match_sid(struct cifs_sid *ctsid)
  54 {
  55         int i, j;
  56         int num_subauth, num_sat, num_saw;
  57         struct cifs_sid *cwsid;
  58
  59         if (!ctsid)
  60                 return (-1);
  61
  62         for (i = 0; i < NUM_WK_SIDS; ++i) {
  63                 cwsid = &(wksidarr[i].cifssid);
  64
  65                 /* compare the revision */
  66                 if (ctsid->revision != cwsid->revision)
  67                         continue;
  68
  69                 /* compare all of the six auth values */
  70                 for (j = 0; j < 6; ++j) {
  71                         if (ctsid->authority[j] != cwsid->authority[j])
  72                                 break;
  73                 }
  74                 if (j < 6)
  75                         continue; /* all of the auth values did not match */
  76
  77                 /* compare all of the subauth values if any */
  78                 num_sat = ctsid->num_subauth;
  79                 num_saw = cwsid->num_subauth;
  80                 num_subauth = num_sat < num_saw ? num_sat : num_saw;
  81                 if (num_subauth) {
  82                         for (j = 0; j < num_subauth; ++j) {
  83                                 if (ctsid->sub_auth[j] != cwsid->sub_auth[j])
  84                                         break;
  85                         }
  86                         if (j < num_subauth)
  87                                 continue; /* all sub_auth values do not match */
  88                 }
  89
  90                 cFYI(1, ("matching sid: %s\n", wksidarr[i].sidname));
  91                 return (0); /* sids compare/match */
  92         }
  93
  94         cFYI(1, ("No matching sid"));
  95         return (-1);
  96 }
  97
  98 /* if the two SIDs (roughly equivalent to a UUID for a user or group) are
  99    the same returns 1, if they do not match returns 0 */
 100 int compare_sids(struct cifs_sid *ctsid, struct cifs_sid *cwsid)
 101 {
 102         int i;
 103         int num_subauth, num_sat, num_saw;
 104
 105         if ((!ctsid) || (!cwsid))
 106                 return (0);
 107
 108         /* compare the revision */
 109         if (ctsid->revision != cwsid->revision)
 110                 return (0);
 111
 112         /* compare all of the six auth values */
 113         for (i = 0; i < 6; ++i) {
 114                 if (ctsid->authority[i] != cwsid->authority[i])
 115                         return (0);
 116         }
 117
 118         /* compare all of the subauth values if any */
 119         num_sat = ctsid->num_subauth;
 120         num_saw = cwsid->num_subauth;
 121         num_subauth = num_sat < num_saw ? num_sat : num_saw;
 122         if (num_subauth) {
 123                 for (i = 0; i < num_subauth; ++i) {
 124                         if (ctsid->sub_auth[i] != cwsid->sub_auth[i])
 125                                 return (0);
 126                 }
 127         }
 128
 129         return (1); /* sids compare/match */
 130 }
 131
 132
 133 static void parse_ace(struct cifs_ace *pace, char *end_of_acl)
 134 {
 135         int num_subauth;
 136
 137         /* validate that we do not go past end of acl */
 138
 139         /* XXX this if statement can be removed
 140         if (end_of_acl < (char *)pace + sizeof(struct cifs_ace)) {
 141                 cERROR(1, ("ACL too small to parse ACE"));
 142                 return;
 143         } */
 144
 145         num_subauth = pace->num_subauth;
 146         if (num_subauth) {
 147 #ifdef CONFIG_CIFS_DEBUG2
 148                 int i;
 149                 cFYI(1, ("ACE revision %d num_subauth %d",
 150                         pace->revision, pace->num_subauth));
 151                 for (i = 0; i < num_subauth; ++i) {
 152                         cFYI(1, ("ACE sub_auth[%d]: 0x%x", i,
 153                                 le32_to_cpu(pace->sub_auth[i])));
 154                 }
 155
 156                 /* BB add length check to make sure that we do not have huge
 157                         num auths and therefore go off the end */
 158
 159                 cFYI(1, ("RID %d", le32_to_cpu(pace->sub_auth[num_subauth-1])));
 160 #endif
 161         }
 162
 163         return;
 164 }
 165
 166 static void parse_ntace(struct cifs_ntace *pntace, char *end_of_acl)
 167 {
 168         /* validate that we do not go past end of acl */
 169         if (end_of_acl < (char *)pntace + sizeof(struct cifs_ntace)) {
 170                 cERROR(1, ("ACL too small to parse NT ACE"));
 171                 return;
 172         }
 173
 174 #ifdef CONFIG_CIFS_DEBUG2
 175         cFYI(1, ("NTACE type %d flags 0x%x size %d, access Req 0x%x",
 176                 pntace->type, pntace->flags, pntace->size,
 177                 pntace->access_req));
 178 #endif
 179         return;
 180 }
 181
 182
 183
 184 static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
 185                        struct cifs_sid *pownersid, struct cifs_sid *pgrpsid)
 186 {
 187         int i;
 188         int num_aces = 0;
 189         int acl_size;
 190         char *acl_base;
 191         struct cifs_ntace **ppntace;
 192         struct cifs_ace **ppace;
 193
 194         /* BB need to add parm so we can store the SID BB */
 195
 196         /* validate that we do not go past end of acl */
 197         if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
 198                 cERROR(1, ("ACL too small to parse DACL"));
 199                 return;
 200         }
 201
 202 #ifdef CONFIG_CIFS_DEBUG2
 203         cFYI(1, ("DACL revision %d size %d num aces %d",
 204                 le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
 205                 le32_to_cpu(pdacl->num_aces)));
 206 #endif
 207
 208         acl_base = (char *)pdacl;
 209         acl_size = sizeof(struct cifs_acl);
 210
 211         num_aces = le32_to_cpu(pdacl->num_aces);
 212         if (num_aces  > 0) {
 213                 ppntace = kmalloc(num_aces * sizeof(struct cifs_ntace *),
 214                                 GFP_KERNEL);
 215                 ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
 216                                 GFP_KERNEL);
 217
 218 /*              cifscred->cecount = pdacl->num_aces;
 219                 cifscred->ntaces = kmalloc(num_aces *
 220                         sizeof(struct cifs_ntace *), GFP_KERNEL);
 221                 cifscred->aces = kmalloc(num_aces *
 222                         sizeof(struct cifs_ace *), GFP_KERNEL);*/
 223
 224                 for (i = 0; i < num_aces; ++i) {
 225                         ppntace[i] = (struct cifs_ntace *)
 226                                         (acl_base + acl_size);
 227                         ppace[i] = (struct cifs_ace *) ((char *)ppntace[i] +
 228                                         sizeof(struct cifs_ntace));
 229
 230                         parse_ntace(ppntace[i], end_of_acl);
 231                         if (end_of_acl < ((char *)ppace[i] +
 232                                         (le16_to_cpu(ppntace[i]->size) -
 233                                         sizeof(struct cifs_ntace)))) {
 234                                 cERROR(1, ("ACL too small to parse ACE"));
 235                                 break;
 236                         } else
 237                                 parse_ace(ppace[i], end_of_acl);
 238
 239 /*                      memcpy((void *)(&(cifscred->ntaces[i])),
 240                                 (void *)ppntace[i],
 241                                 sizeof(struct cifs_ntace));
 242                         memcpy((void *)(&(cifscred->aces[i])),
 243                                 (void *)ppace[i],
 244                                 sizeof(struct cifs_ace)); */
 245
 246                         acl_base = (char *)ppntace[i];
 247                         acl_size = le16_to_cpu(ppntace[i]->size);
 248                 }
 249
 250                 kfree(ppace);
 251                 kfree(ppntace);
 252         }
 253
 254         return;
 255 }
 256
 257
 258 static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
 259 {
 260
 261         /* BB need to add parm so we can store the SID BB */
 262
 263         /* validate that we do not go past end of acl */
 264         if (end_of_acl < (char *)psid + sizeof(struct cifs_sid)) {
 265                 cERROR(1, ("ACL too small to parse SID"));
 266                 return -EINVAL;
 267         }
 268
 269         if (psid->num_subauth) {
 270 #ifdef CONFIG_CIFS_DEBUG2
 271                 int i;
 272                 cFYI(1, ("SID revision %d num_auth %d First subauth 0x%x",
 273                         psid->revision, psid->num_subauth, psid->sub_auth[0]));
 274
 275                 for (i = 0; i < psid->num_subauth; i++) {
 276                         cFYI(1, ("SID sub_auth[%d]: 0x%x ", i,
 277                                 le32_to_cpu(psid->sub_auth[i])));
 278                 }
 279
 280                 /* BB add length check to make sure that we do not have huge
 281                         num auths and therefore go off the end */
 282                 cFYI(1, ("RID 0x%x",
 283                         le32_to_cpu(psid->sub_auth[psid->num_subauth-1])));
 284 #endif
 285         }
 286
 287         return 0;
 288 }
 289
 290
 291 /* Convert CIFS ACL to POSIX form */
 292 int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len)
 293 {
 294         int rc;
 295         struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
 296         struct cifs_acl *dacl_ptr; /* no need for SACL ptr */
 297         char *end_of_acl = ((char *)pntsd) + acl_len;
 298
 299         owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
 300                                 le32_to_cpu(pntsd->osidoffset));
 301         group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
 302                                 le32_to_cpu(pntsd->gsidoffset));
 303         dacl_ptr = (struct cifs_acl *)((char *)pntsd +
 304                                 le32_to_cpu(pntsd->dacloffset));
 305 #ifdef CONFIG_CIFS_DEBUG2
 306         cFYI(1, ("revision %d type 0x%x ooffset 0x%x goffset 0x%x "
 307                  "sacloffset 0x%x dacloffset 0x%x",
 308                  pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
 309                  le32_to_cpu(pntsd->gsidoffset),
 310                  le32_to_cpu(pntsd->sacloffset),
 311                  le32_to_cpu(pntsd->dacloffset)));
 312 #endif
 313         rc = parse_sid(owner_sid_ptr, end_of_acl);
 314         if (rc)
 315                 return rc;
 316
 317         rc = parse_sid(group_sid_ptr, end_of_acl);
 318         if (rc)
 319                 return rc;
 320
 321         parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr);
 322
 323 /*      cifscred->uid = owner_sid_ptr->rid;
 324         cifscred->gid = group_sid_ptr->rid;
 325         memcpy((void *)(&(cifscred->osid)), (void *)owner_sid_ptr,
 326                         sizeof (struct cifs_sid));
 327         memcpy((void *)(&(cifscred->gsid)), (void *)group_sid_ptr,
 328                         sizeof (struct cifs_sid)); */
 329
 330
 331         return (0);
 332 }
 333 #endif /* CONFIG_CIFS_EXPERIMENTAL */