fs/ext3/xattr_security.c

   1 /*
   2  * linux/fs/ext3/xattr_security.c
   3  * Handler for storing security labels as extended attributes.
   4  */
   5
   6 #include <linux/slab.h>
   7 #include <linux/string.h>
   8 #include <linux/fs.h>
   9 #include <linux/ext3_jbd.h>
  10 #include <linux/ext3_fs.h>
  11 #include <linux/security.h>
  12 #include "xattr.h"
  13
  14 static size_t
  15 ext3_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
  16                          const char *name, size_t name_len, int type)
  17 {
  18         const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
  19         const size_t total_len = prefix_len + name_len + 1;
  20
  21
  22         if (list && total_len <= list_size) {
  23                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
  24                 memcpy(list+prefix_len, name, name_len);
  25                 list[prefix_len + name_len] = '\0';
  26         }
  27         return total_len;
  28 }
  29
  30 static int
  31 ext3_xattr_security_get(struct dentry *dentry, const char *name,
  32                 void *buffer, size_t size, int type)
  33 {
  34         if (strcmp(name, "") == 0)
  35                 return -EINVAL;
  36         return ext3_xattr_get(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
  37                               name, buffer, size);
  38 }
  39
  40 static int
  41 ext3_xattr_security_set(struct dentry *dentry, const char *name,
  42                 const void *value, size_t size, int flags, int type)
  43 {
  44         if (strcmp(name, "") == 0)
  45                 return -EINVAL;
  46         return ext3_xattr_set(dentry->d_inode, EXT3_XATTR_INDEX_SECURITY,
  47                               name, value, size, flags);
  48 }
  49
  50 int ext3_initxattrs(struct inode *inode, const struct xattr *xattr_array,
  51                     void *fs_info)
  52 {
  53         const struct xattr *xattr;
  54         handle_t *handle = fs_info;
  55         int err = 0;
  56
  57         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  58                 err = ext3_xattr_set_handle(handle, inode,
  59                                             EXT3_XATTR_INDEX_SECURITY,
  60                                             xattr->name, xattr->value,
  61                                             xattr->value_len, 0);
  62                 if (err < 0)
  63                         break;
  64         }
  65         return err;
  66 }
  67
  68 int
  69 ext3_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
  70                    const struct qstr *qstr)
  71 {
  72         return security_inode_init_security(inode, dir, qstr,
  73                                             &ext3_initxattrs, handle);
  74 }
  75
  76 const struct xattr_handler ext3_xattr_security_handler = {
  77         .prefix = XATTR_SECURITY_PREFIX,
  78         .list   = ext3_xattr_security_list,
  79         .get    = ext3_xattr_security_get,
  80         .set    = ext3_xattr_security_set,
  81 };