root/fs/ext2/xattr_security.c

DEFINITIONS

1. ext2_xattr_security_list
2. ext2_xattr_security_get
3. ext2_xattr_security_set
4. ext2_init_security

/*
 * linux/fs/ext2/xattr_security.c
 * Handler for storing security labels as extended attributes.
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/security.h>
#include "xattr.h"

static size_t
ext2_xattr_security_list(struct inode *inode, char *list, size_t list_size,
                         const char *name, size_t name_len)
{
        const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
        const size_t total_len = prefix_len + name_len + 1;

        if (list && total_len <= list_size) {
                memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
                memcpy(list+prefix_len, name, name_len);
                list[prefix_len + name_len] = '\0';
        }
        return total_len;
}

static int
ext2_xattr_security_get(struct inode *inode, const char *name,
                       void *buffer, size_t size)
{
        if (strcmp(name, "") == 0)
                return -EINVAL;
        return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
                              buffer, size);
}

static int
ext2_xattr_security_set(struct inode *inode, const char *name,
                       const void *value, size_t size, int flags)
{
        if (strcmp(name, "") == 0)
                return -EINVAL;
        return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
                              value, size, flags);
}

int
ext2_init_security(struct inode *inode, struct inode *dir)
{
        int err;
        size_t len;
        void *value;
        char *name;

        err = security_inode_init_security(inode, dir, &name, &value, &len);
        if (err) {
                if (err == -EOPNOTSUPP)
                        return 0;
                return err;
        }
        err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
                             name, value, len, 0);
        kfree(name);
        kfree(value);
        return err;
}

struct xattr_handler ext2_xattr_security_handler = {
        .prefix = XATTR_SECURITY_PREFIX,
        .list   = ext2_xattr_security_list,
        .get    = ext2_xattr_security_get,
        .set    = ext2_xattr_security_set,
};