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
  99 int compare_sids(struct cifs_sid *ctsid, struct cifs_sid *cwsid)
 100 {
 101         int i;
 102         int num_subauth, num_sat, num_saw;
 103
 104         if ((!ctsid) || (!cwsid))
 105                 return (-1);
 106
 107         /* compare the revision */
 108         if (ctsid->revision != cwsid->revision)
 109                 return (-1);
 110
 111         /* compare all of the six auth values */
 112         for (i = 0; i < 6; ++i) {
 113                 if (ctsid->authority[i] != cwsid->authority[i])
 114                         return (-1);
 115         }
 116
 117         /* compare all of the subauth values if any */
 118         num_sat = cpu_to_le32(ctsid->num_subauth);
 119         num_saw = cpu_to_le32(cwsid->num_subauth);
 120         num_subauth = num_sat < num_saw ? num_sat : num_saw;
 121         if (num_subauth) {
 122                 for (i = 0; i < num_subauth; ++i) {
 123                         if (ctsid->sub_auth[i] != cwsid->sub_auth[i])
 124                                 return (-1);
 125                 }
 126         }
 127
 128         return (0); /* sids compare/match */
 129 }
 130
 131
 132 static void parse_ace(struct cifs_ace *pace, char *end_of_acl)
 133 {
 134         int num_subauth;
 135
 136         /* validate that we do not go past end of acl */
 137
 138         /* XXX this if statement can be removed
 139         if (end_of_acl < (char *)pace + sizeof(struct cifs_ace)) {
 140                 cERROR(1, ("ACL too small to parse ACE"));
 141                 return;
 142         } */
 143
 144         num_subauth = pace->num_subauth;
 145         if (num_subauth) {
 146 #ifdef CONFIG_CIFS_DEBUG2
 147                 int i;
 148                 cFYI(1, ("ACE revision %d num_subauth %d",
 149                         pace->revision, pace->num_subauth));
 150                 for (i = 0; i < num_subauth; ++i) {
 151                         cFYI(1, ("ACE sub_auth[%d]: 0x%x", i,
 152                                 le32_to_cpu(pace->sub_auth[i])));
 153                 }
 154
 155                 /* BB add length check to make sure that we do not have huge
 156                         num auths and therefore go off the end */
 157
 158                 cFYI(1, ("RID %d", le32_to_cpu(pace->sub_auth[num_subauth-1])));
 159 #endif
 160         }
 161
 162         return;
 163 }
 164
 165 static void parse_ntace(struct cifs_ntace *pntace, char *end_of_acl)
 166 {
 167         /* validate that we do not go past end of acl */
 168         if (end_of_acl < (char *)pntace + sizeof(struct cifs_ntace)) {
 169                 cERROR(1, ("ACL too small to parse NT ACE"));
 170                 return;
 171         }
 172
 173 #ifdef CONFIG_CIFS_DEBUG2
 174         cFYI(1, ("NTACE type %d flags 0x%x size %d, access Req 0x%x",
 175                 pntace->type, pntace->flags, pntace->size,
 176                 pntace->access_req));
 177 #endif
 178         return;
 179 }
 180
 181
 182
 183 static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl)
 184 {
 185         int i;
 186         int num_aces = 0;
 187         int acl_size;
 188         char *acl_base;
 189         struct cifs_ntace **ppntace;
 190         struct cifs_ace **ppace;
 191
 192         /* BB need to add parm so we can store the SID BB */
 193
 194         /* validate that we do not go past end of acl */
 195         if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
 196                 cERROR(1, ("ACL too small to parse DACL"));
 197                 return;
 198         }
 199
 200 #ifdef CONFIG_CIFS_DEBUG2
 201         cFYI(1, ("DACL revision %d size %d num aces %d",
 202                 le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
 203                 le32_to_cpu(pdacl->num_aces)));
 204 #endif
 205
 206         acl_base = (char *)pdacl;
 207         acl_size = sizeof(struct cifs_acl);
 208
 209         num_aces = cpu_to_le32(pdacl->num_aces);
 210         if (num_aces  > 0) {
 211                 ppntace = kmalloc(num_aces * sizeof(struct cifs_ntace *),
 212                                 GFP_KERNEL);
 213                 ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
 214                                 GFP_KERNEL);
 215
 216 /*              cifscred->cecount = pdacl->num_aces;
 217                 cifscred->ntaces = kmalloc(num_aces *
 218                         sizeof(struct cifs_ntace *), GFP_KERNEL);
 219                 cifscred->aces = kmalloc(num_aces *
 220                         sizeof(struct cifs_ace *), GFP_KERNEL);*/
 221
 222
 223                 for (i = 0; i < num_aces; ++i) {
 224                         ppntace[i] = (struct cifs_ntace *)
 225                                         (acl_base + acl_size);
 226                         ppace[i] = (struct cifs_ace *) ((char *)ppntace[i] +
 227                                         sizeof(struct cifs_ntace));
 228
 229                         parse_ntace(ppntace[i], end_of_acl);
 230                         if (end_of_acl < ((char *)ppace[i] +
 231                                         (le16_to_cpu(ppntace[i]->size) -
 232                                         sizeof(struct cifs_ntace)))) {
 233                                 cERROR(1, ("ACL too small to parse ACE"));
 234                                 break;
 235                         } else
 236                                 parse_ace(ppace[i], end_of_acl);
 237
 238 /*                      memcpy((void *)(&(cifscred->ntaces[i])),
 239                                 (void *)ppntace[i],
 240                                 sizeof(struct cifs_ntace));
 241                         memcpy((void *)(&(cifscred->aces[i])),
 242                                 (void *)ppace[i],
 243                                 sizeof(struct cifs_ace)); */
 244
 245                         acl_base = (char *)ppntace[i];
 246                         acl_size = le16_to_cpu(ppntace[i]->size);
 247                 }
 248
 249                 kfree(ppace);
 250                 kfree(ppntace);
 251         }
 252
 253         return;
 254 }
 255
 256
 257 static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
 258 {
 259
 260         /* BB need to add parm so we can store the SID BB */
 261
 262         /* validate that we do not go past end of acl */
 263         if (end_of_acl < (char *)psid + sizeof(struct cifs_sid)) {
 264                 cERROR(1, ("ACL too small to parse SID"));
 265                 return -EINVAL;
 266         }
 267
 268         if (psid->num_subauth) {
 269 #ifdef CONFIG_CIFS_DEBUG2
 270                 int i;
 271                 cFYI(1, ("SID revision %d num_auth %d First subauth 0x%x",
 272                         psid->revision, psid->num_subauth, psid->sub_auth[0]));
 273
 274                 for (i = 0; i < psid->num_subauth; i++) {
 275                         cFYI(1, ("SID sub_auth[%d]: 0x%x ", i,
 276                                 le32_to_cpu(psid->sub_auth[i])));
 277                 }
 278
 279                 /* BB add length check to make sure that we do not have huge
 280                         num auths and therefore go off the end */
 281                 cFYI(1, ("RID 0x%x",
 282                         le32_to_cpu(psid->sub_auth[psid->num_subauth-1])));
 283 #endif
 284         }
 285
 286         return 0;
 287 }
 288
 289
 290 /* Convert CIFS ACL to POSIX form */
 291 int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len)
 292 {
 293         int rc;
 294         struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
 295         struct cifs_acl *dacl_ptr; /* no need for SACL ptr */
 296         char *end_of_acl = ((char *)pntsd) + acl_len;
 297
 298         owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
 299                                 le32_to_cpu(pntsd->osidoffset));
 300         group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
 301                                 le32_to_cpu(pntsd->gsidoffset));
 302         dacl_ptr = (struct cifs_acl *)((char *)pntsd +
 303                                 le32_to_cpu(pntsd->dacloffset));
 304 #ifdef CONFIG_CIFS_DEBUG2
 305         cFYI(1, ("revision %d type 0x%x ooffset 0x%x goffset 0x%x "
 306                  "sacloffset 0x%x dacloffset 0x%x",
 307                  pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
 308                  le32_to_cpu(pntsd->gsidoffset),
 309                  le32_to_cpu(pntsd->sacloffset),
 310                  le32_to_cpu(pntsd->dacloffset)));
 311 #endif
 312         rc = parse_sid(owner_sid_ptr, end_of_acl);
 313         if (rc)
 314                 return rc;
 315
 316         rc = parse_sid(group_sid_ptr, end_of_acl);
 317         if (rc)
 318                 return rc;
 319
 320         parse_dacl(dacl_ptr, end_of_acl);
 321
 322 /*      cifscred->uid = owner_sid_ptr->rid;
 323         cifscred->gid = group_sid_ptr->rid;
 324         memcpy((void *)(&(cifscred->osid)), (void *)owner_sid_ptr,
 325                         sizeof (struct cifs_sid));
 326         memcpy((void *)(&(cifscred->gsid)), (void *)group_sid_ptr,
 327                         sizeof (struct cifs_sid)); */
 328
 329
 330         return (0);
 331 }
 332 #endif /* CONFIG_CIFS_EXPERIMENTAL */