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 *dentry,
  13              const char *name, void *buffer, size_t size)
  14 {
  15         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  16                 return -EINVAL;
  17
  18         if (IS_PRIVATE(d_inode(dentry)))
  19                 return -EPERM;
  20
  21         return reiserfs_xattr_get(d_inode(dentry), name, buffer, size);
  22 }
  23
  24 static int
  25 security_set(const struct xattr_handler *handler, struct dentry *dentry,
  26              const char *name, const void *buffer, size_t size, int flags)
  27 {
  28         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
  29                 return -EINVAL;
  30
  31         if (IS_PRIVATE(d_inode(dentry)))
  32                 return -EPERM;
  33
  34         return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags);
  35 }
  36
  37 static size_t security_list(const struct xattr_handler *handler,
  38                             struct dentry *dentry, char *list, size_t list_len,
  39                             const char *name, size_t namelen)
  40 {
  41         const size_t len = namelen + 1;
  42
  43         if (IS_PRIVATE(d_inode(dentry)))
  44                 return 0;
  45
  46         if (list && len <= list_len) {
  47                 memcpy(list, name, namelen);
  48                 list[namelen] = '\0';
  49         }
  50
  51         return len;
  52 }
  53
  54 /* Initializes the security context for a new inode and returns the number
  55  * of blocks needed for the transaction. If successful, reiserfs_security
  56  * must be released using reiserfs_security_free when the caller is done. */
  57 int reiserfs_security_init(struct inode *dir, struct inode *inode,
  58                            const struct qstr *qstr,
  59                            struct reiserfs_security_handle *sec)
  60 {
  61         int blocks = 0;
  62         int error;
  63
  64         sec->name = NULL;
  65
  66         /* Don't add selinux attributes on xattrs - they'll never get used */
  67         if (IS_PRIVATE(dir))
  68                 return 0;
  69
  70         error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
  71                                                  &sec->value, &sec->length);
  72         if (error) {
  73                 if (error == -EOPNOTSUPP)
  74                         error = 0;
  75
  76                 sec->name = NULL;
  77                 sec->value = NULL;
  78                 sec->length = 0;
  79                 return error;
  80         }
  81
  82         if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
  83                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
  84                          reiserfs_xattr_nblocks(inode, sec->length);
  85                 /* We don't want to count the directories twice if we have
  86                  * a default ACL. */
  87                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
  88         }
  89         return blocks;
  90 }
  91
  92 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
  93                             struct inode *inode,
  94                             struct reiserfs_security_handle *sec)
  95 {
  96         int error;
  97         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
  98                 return -EINVAL;
  99
 100         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
 101                                           sec->length, XATTR_CREATE);
 102         if (error == -ENODATA || error == -EOPNOTSUPP)
 103                 error = 0;
 104
 105         return error;
 106 }
 107
 108 void reiserfs_security_free(struct reiserfs_security_handle *sec)
 109 {
 110         kfree(sec->name);
 111         kfree(sec->value);
 112         sec->name = NULL;
 113         sec->value = NULL;
 114 }
 115
 116 const struct xattr_handler reiserfs_xattr_security_handler = {
 117         .prefix = XATTR_SECURITY_PREFIX,
 118         .get = security_get,
 119         .set = security_set,
 120         .list = security_list,
 121 };