fs/ocfs2/acl.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * acl.c
   5  *
   6  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   7  *
   8  * CREDITS:
   9  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
  10  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public
  14  * License version 2 as published by the Free Software Foundation.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/string.h>
  25
  26 #define MLOG_MASK_PREFIX ML_INODE
  27 #include <cluster/masklog.h>
  28
  29 #include "ocfs2.h"
  30 #include "alloc.h"
  31 #include "dlmglue.h"
  32 #include "file.h"
  33 #include "ocfs2_fs.h"
  34
  35 #include "xattr.h"
  36 #include "acl.h"
  37
  38 /*
  39  * Convert from xattr value to acl struct.
  40  */
  41 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  42 {
  43         int n, count;
  44         struct posix_acl *acl;
  45
  46         if (!value)
  47                 return NULL;
  48         if (size < sizeof(struct posix_acl_entry))
  49                 return ERR_PTR(-EINVAL);
  50
  51         count = size / sizeof(struct posix_acl_entry);
  52         if (count < 0)
  53                 return ERR_PTR(-EINVAL);
  54         if (count == 0)
  55                 return NULL;
  56
  57         acl = posix_acl_alloc(count, GFP_NOFS);
  58         if (!acl)
  59                 return ERR_PTR(-ENOMEM);
  60         for (n = 0; n < count; n++) {
  61                 struct ocfs2_acl_entry *entry =
  62                         (struct ocfs2_acl_entry *)value;
  63
  64                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  65                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  66                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
  67                 value += sizeof(struct posix_acl_entry);
  68
  69         }
  70         return acl;
  71 }
  72
  73 /*
  74  * Convert acl struct to xattr value.
  75  */
  76 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  77 {
  78         struct ocfs2_acl_entry *entry = NULL;
  79         char *ocfs2_acl;
  80         size_t n;
  81
  82         *size = acl->a_count * sizeof(struct posix_acl_entry);
  83
  84         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  85         if (!ocfs2_acl)
  86                 return ERR_PTR(-ENOMEM);
  87
  88         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  89         for (n = 0; n < acl->a_count; n++, entry++) {
  90                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  91                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  92                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
  93         }
  94         return ocfs2_acl;
  95 }
  96
  97 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
  98                                               int type,
  99                                               struct buffer_head *di_bh)
 100 {
 101         int name_index;
 102         char *value = NULL;
 103         struct posix_acl *acl;
 104         int retval;
 105
 106         switch (type) {
 107         case ACL_TYPE_ACCESS:
 108                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 109                 break;
 110         case ACL_TYPE_DEFAULT:
 111                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 112                 break;
 113         default:
 114                 return ERR_PTR(-EINVAL);
 115         }
 116
 117         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 118         if (retval > 0) {
 119                 value = kmalloc(retval, GFP_NOFS);
 120                 if (!value)
 121                         return ERR_PTR(-ENOMEM);
 122                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 123                                                 "", value, retval);
 124         }
 125
 126         if (retval > 0)
 127                 acl = ocfs2_acl_from_xattr(value, retval);
 128         else if (retval == -ENODATA || retval == 0)
 129                 acl = NULL;
 130         else
 131                 acl = ERR_PTR(retval);
 132
 133         kfree(value);
 134
 135         return acl;
 136 }
 137
 138
 139 /*
 140  * Get posix acl.
 141  */
 142 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
 143 {
 144         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 145         struct buffer_head *di_bh = NULL;
 146         struct posix_acl *acl;
 147         int ret;
 148
 149         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 150                 return NULL;
 151
 152         ret = ocfs2_inode_lock(inode, &di_bh, 0);
 153         if (ret < 0) {
 154                 mlog_errno(ret);
 155                 acl = ERR_PTR(ret);
 156                 return acl;
 157         }
 158
 159         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 160
 161         ocfs2_inode_unlock(inode, 0);
 162
 163         brelse(di_bh);
 164
 165         return acl;
 166 }
 167
 168 /*
 169  * Set the access or default ACL of an inode.
 170  */
 171 static int ocfs2_set_acl(handle_t *handle,
 172                          struct inode *inode,
 173                          struct buffer_head *di_bh,
 174                          int type,
 175                          struct posix_acl *acl,
 176                          struct ocfs2_alloc_context *meta_ac,
 177                          struct ocfs2_alloc_context *data_ac)
 178 {
 179         int name_index;
 180         void *value = NULL;
 181         size_t size = 0;
 182         int ret;
 183
 184         if (S_ISLNK(inode->i_mode))
 185                 return -EOPNOTSUPP;
 186
 187         switch (type) {
 188         case ACL_TYPE_ACCESS:
 189                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 190                 if (acl) {
 191                         mode_t mode = inode->i_mode;
 192                         ret = posix_acl_equiv_mode(acl, &mode);
 193                         if (ret < 0)
 194                                 return ret;
 195                         else {
 196                                 inode->i_mode = mode;
 197                                 if (ret == 0)
 198                                         acl = NULL;
 199                         }
 200                 }
 201                 break;
 202         case ACL_TYPE_DEFAULT:
 203                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 204                 if (!S_ISDIR(inode->i_mode))
 205                         return acl ? -EACCES : 0;
 206                 break;
 207         default:
 208                 return -EINVAL;
 209         }
 210
 211         if (acl) {
 212                 value = ocfs2_acl_to_xattr(acl, &size);
 213                 if (IS_ERR(value))
 214                         return (int)PTR_ERR(value);
 215         }
 216
 217         if (handle)
 218                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 219                                              "", value, size, 0,
 220                                              meta_ac, data_ac);
 221         else
 222                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 223
 224         kfree(value);
 225
 226         return ret;
 227 }
 228
 229 int ocfs2_check_acl(struct inode *inode, int mask)
 230 {
 231         struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 232
 233         if (IS_ERR(acl))
 234                 return PTR_ERR(acl);
 235         if (acl) {
 236                 int ret = posix_acl_permission(inode, acl, mask);
 237                 posix_acl_release(acl);
 238                 return ret;
 239         }
 240
 241         return -EAGAIN;
 242 }
 243
 244 int ocfs2_acl_chmod(struct inode *inode)
 245 {
 246         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 247         struct posix_acl *acl, *clone;
 248         int ret;
 249
 250         if (S_ISLNK(inode->i_mode))
 251                 return -EOPNOTSUPP;
 252
 253         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 254                 return 0;
 255
 256         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
 257         if (IS_ERR(acl) || !acl)
 258                 return PTR_ERR(acl);
 259         clone = posix_acl_clone(acl, GFP_KERNEL);
 260         posix_acl_release(acl);
 261         if (!clone)
 262                 return -ENOMEM;
 263         ret = posix_acl_chmod_masq(clone, inode->i_mode);
 264         if (!ret)
 265                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 266                                     clone, NULL, NULL);
 267         posix_acl_release(clone);
 268         return ret;
 269 }
 270
 271 /*
 272  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 273  * then clone to new inode. Called from ocfs2_mknod.
 274  */
 275 int ocfs2_init_acl(handle_t *handle,
 276                    struct inode *inode,
 277                    struct inode *dir,
 278                    struct buffer_head *di_bh,
 279                    struct buffer_head *dir_bh,
 280                    struct ocfs2_alloc_context *meta_ac,
 281                    struct ocfs2_alloc_context *data_ac)
 282 {
 283         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 284         struct posix_acl *acl = NULL;
 285         int ret = 0;
 286
 287         if (!S_ISLNK(inode->i_mode)) {
 288                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 289                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 290                                                    dir_bh);
 291                         if (IS_ERR(acl))
 292                                 return PTR_ERR(acl);
 293                 }
 294                 if (!acl)
 295                         inode->i_mode &= ~current_umask();
 296         }
 297         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 298                 struct posix_acl *clone;
 299                 mode_t mode;
 300
 301                 if (S_ISDIR(inode->i_mode)) {
 302                         ret = ocfs2_set_acl(handle, inode, di_bh,
 303                                             ACL_TYPE_DEFAULT, acl,
 304                                             meta_ac, data_ac);
 305                         if (ret)
 306                                 goto cleanup;
 307                 }
 308                 clone = posix_acl_clone(acl, GFP_NOFS);
 309                 ret = -ENOMEM;
 310                 if (!clone)
 311                         goto cleanup;
 312
 313                 mode = inode->i_mode;
 314                 ret = posix_acl_create_masq(clone, &mode);
 315                 if (ret >= 0) {
 316                         inode->i_mode = mode;
 317                         if (ret > 0) {
 318                                 ret = ocfs2_set_acl(handle, inode,
 319                                                     di_bh, ACL_TYPE_ACCESS,
 320                                                     clone, meta_ac, data_ac);
 321                         }
 322                 }
 323                 posix_acl_release(clone);
 324         }
 325 cleanup:
 326         posix_acl_release(acl);
 327         return ret;
 328 }
 329
 330 static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
 331                                           char *list,
 332                                           size_t list_len,
 333                                           const char *name,
 334                                           size_t name_len,
 335                                           int type)
 336 {
 337         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 338         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
 339
 340         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 341                 return 0;
 342
 343         if (list && size <= list_len)
 344                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
 345         return size;
 346 }
 347
 348 static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
 349                                            char *list,
 350                                            size_t list_len,
 351                                            const char *name,
 352                                            size_t name_len,
 353                                            int type)
 354 {
 355         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 356         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
 357
 358         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 359                 return 0;
 360
 361         if (list && size <= list_len)
 362                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
 363         return size;
 364 }
 365
 366 static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
 367                 void *buffer, size_t size, int type)
 368 {
 369         struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 370         struct posix_acl *acl;
 371         int ret;
 372
 373         if (strcmp(name, "") != 0)
 374                 return -EINVAL;
 375         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 376                 return -EOPNOTSUPP;
 377
 378         acl = ocfs2_get_acl(dentry->d_inode, type);
 379         if (IS_ERR(acl))
 380                 return PTR_ERR(acl);
 381         if (acl == NULL)
 382                 return -ENODATA;
 383         ret = posix_acl_to_xattr(acl, buffer, size);
 384         posix_acl_release(acl);
 385
 386         return ret;
 387 }
 388
 389 static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
 390                 const void *value, size_t size, int flags, int type)
 391 {
 392         struct inode *inode = dentry->d_inode;
 393         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 394         struct posix_acl *acl;
 395         int ret = 0;
 396
 397         if (strcmp(name, "") != 0)
 398                 return -EINVAL;
 399         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 400                 return -EOPNOTSUPP;
 401
 402         if (!is_owner_or_cap(inode))
 403                 return -EPERM;
 404
 405         if (value) {
 406                 acl = posix_acl_from_xattr(value, size);
 407                 if (IS_ERR(acl))
 408                         return PTR_ERR(acl);
 409                 else if (acl) {
 410                         ret = posix_acl_valid(acl);
 411                         if (ret)
 412                                 goto cleanup;
 413                 }
 414         } else
 415                 acl = NULL;
 416
 417         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 418
 419 cleanup:
 420         posix_acl_release(acl);
 421         return ret;
 422 }
 423
 424 struct xattr_handler ocfs2_xattr_acl_access_handler = {
 425         .prefix = POSIX_ACL_XATTR_ACCESS,
 426         .flags  = ACL_TYPE_ACCESS,
 427         .list   = ocfs2_xattr_list_acl_access,
 428         .get    = ocfs2_xattr_get_acl,
 429         .set    = ocfs2_xattr_set_acl,
 430 };
 431
 432 struct xattr_handler ocfs2_xattr_acl_default_handler = {
 433         .prefix = POSIX_ACL_XATTR_DEFAULT,
 434         .flags  = ACL_TYPE_DEFAULT,
 435         .list   = ocfs2_xattr_list_acl_default,
 436         .get    = ocfs2_xattr_get_acl,
 437         .set    = ocfs2_xattr_set_acl,
 438 };