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