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 dentry *dentry, const char *name, void *buffer, size_t size,
  12                 int handler_flags)
  13 {
  14         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  15                 return -EINVAL;
  16
  17         if (IS_PRIVATE(dentry->d_inode))
  18                 return -EPERM;
  19
  20         return reiserfs_xattr_get(dentry->d_inode, name, buffer, size);
  21 }
  22
  23 static int
  24 security_set(struct dentry *dentry, const char *name, const void *buffer,
  25              size_t size, int flags, int handler_flags)
  26 {
  27         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  28                 return -EINVAL;
  29
  30         if (IS_PRIVATE(dentry->d_inode))
  31                 return -EPERM;
  32
  33         return reiserfs_xattr_set(dentry->d_inode, name, buffer, size, flags);
  34 }
  35
  36 static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
  37                             const char *name, size_t namelen, int handler_flags)
  38 {
  39         const size_t len = namelen + 1;
  40
  41         if (IS_PRIVATE(dentry->d_inode))
  42                 return 0;
  43
  44         if (list && len <= list_len) {
  45                 memcpy(list, name, namelen);
  46                 list[namelen] = '\0';
  47         }
  48
  49         return len;
  50 }
  51
  52 /* Initializes the security context for a new inode and returns the number
  53  * of blocks needed for the transaction. If successful, reiserfs_security
  54  * must be released using reiserfs_security_free when the caller is done. */
  55 int reiserfs_security_init(struct inode *dir, struct inode *inode,
  56                            struct reiserfs_security_handle *sec)
  57 {
  58         int blocks = 0;
  59         int error;
  60
  61         sec->name = NULL;
  62
  63         /* Don't add selinux attributes on xattrs - they'll never get used */
  64         if (IS_PRIVATE(dir))
  65                 return 0;
  66
  67         error = security_inode_init_security(inode, dir, &sec->name,
  68                                              &sec->value, &sec->length);
  69         if (error) {
  70                 if (error == -EOPNOTSUPP)
  71                         error = 0;
  72
  73                 sec->name = NULL;
  74                 sec->value = NULL;
  75                 sec->length = 0;
  76                 return error;
  77         }
  78
  79         if (sec->length) {
  80                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
  81                          reiserfs_xattr_nblocks(inode, sec->length);
  82                 /* We don't want to count the directories twice if we have
  83                  * a default ACL. */
  84                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
  85         }
  86         return blocks;
  87 }
  88
  89 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
  90                             struct inode *inode,
  91                             struct reiserfs_security_handle *sec)
  92 {
  93         int error;
  94         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
  95                 return -EINVAL;
  96
  97         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
  98                                           sec->length, XATTR_CREATE);
  99         if (error == -ENODATA || error == -EOPNOTSUPP)
 100                 error = 0;
 101
 102         return error;
 103 }
 104
 105 void reiserfs_security_free(struct reiserfs_security_handle *sec)
 106 {
 107         kfree(sec->name);
 108         kfree(sec->value);
 109         sec->name = NULL;
 110         sec->value = NULL;
 111 }
 112
 113 struct xattr_handler reiserfs_xattr_security_handler = {
 114         .prefix = XATTR_SECURITY_PREFIX,
 115         .get = security_get,
 116         .set = security_set,
 117         .list = security_list,
 118 };