fs/reiserfs/xattr_security.c

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