fs/reiserfs/xattr_security.c

   1 #include <linux/reiserfs_fs.h>
   2 #include <linux/errno.h>
   3 #include <linux/fs.h>
   4 #include <linux/pagemap.h>
   5 #include <linux/xattr.h>
   6 #include <linux/reiserfs_xattr.h>
   7 #include <linux/security.h>
   8 #include <asm/uaccess.h>
   9
  10 static int
  11 security_get(struct inode *inode, const char *name, void *buffer, size_t size)
  12 {
  13         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  14                 return -EINVAL;
  15
  16         if (IS_PRIVATE(inode))
  17                 return -EPERM;
  18
  19         return reiserfs_xattr_get(inode, name, buffer, size);
  20 }
  21
  22 static int
  23 security_set(struct inode *inode, const char *name, const void *buffer,
  24              size_t size, int flags)
  25 {
  26         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  27                 return -EINVAL;
  28
  29         if (IS_PRIVATE(inode))
  30                 return -EPERM;
  31
  32         return reiserfs_xattr_set(inode, name, buffer, size, flags);
  33 }
  34
  35 static size_t security_list(struct inode *inode, char *list, size_t list_len,
  36                             const char *name, size_t namelen)
  37 {
  38         const size_t len = namelen + 1;
  39
  40         if (IS_PRIVATE(inode))
  41                 return 0;
  42
  43         if (list && len <= list_len) {
  44                 memcpy(list, name, namelen);
  45                 list[namelen] = '\0';
  46         }
  47
  48         return len;
  49 }
  50
  51 /* Initializes the security context for a new inode and returns the number
  52  * of blocks needed for the transaction. If successful, reiserfs_security
  53  * must be released using reiserfs_security_free when the caller is done. */
  54 int reiserfs_security_init(struct inode *dir, struct inode *inode,
  55                            struct reiserfs_security_handle *sec)
  56 {
  57         int blocks = 0;
  58         int error;
  59
  60         sec->name = NULL;
  61
  62         /* Don't add selinux attributes on xattrs - they'll never get used */
  63         if (IS_PRIVATE(dir))
  64                 return 0;
  65
  66         error = security_inode_init_security(inode, dir, &sec->name,
  67                                              &sec->value, &sec->length);
  68         if (error) {
  69                 if (error == -EOPNOTSUPP)
  70                         error = 0;
  71
  72                 sec->name = NULL;
  73                 sec->value = NULL;
  74                 sec->length = 0;
  75                 return error;
  76         }
  77
  78         if (sec->length) {
  79                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
  80                          reiserfs_xattr_nblocks(inode, sec->length);
  81                 /* We don't want to count the directories twice if we have
  82                  * a default ACL. */
  83                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
  84         }
  85         return blocks;
  86 }
  87
  88 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
  89                             struct inode *inode,
  90                             struct reiserfs_security_handle *sec)
  91 {
  92         int error;
  93         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
  94                 return -EINVAL;
  95
  96         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
  97                                           sec->length, XATTR_CREATE);
  98         if (error == -ENODATA || error == -EOPNOTSUPP)
  99                 error = 0;
 100
 101         return error;
 102 }
 103
 104 void reiserfs_security_free(struct reiserfs_security_handle *sec)
 105 {
 106         kfree(sec->name);
 107         kfree(sec->value);
 108         sec->name = NULL;
 109         sec->value = NULL;
 110 }
 111
 112 struct xattr_handler reiserfs_xattr_security_handler = {
 113         .prefix = XATTR_SECURITY_PREFIX,
 114         .get = security_get,
 115         .set = security_set,
 116         .list = security_list,
 117 };