/*
 * Linux Security Module interfaces
 *
 * Copyright (C) 2001 WireX Communications, Inc <[email protected]>
 * Copyright (C) 2001 Greg Kroah-Hartman <[email protected]>
 * Copyright (C) 2001 Networks Associates Technology, Inc <[email protected]>
 * Copyright (C) 2001 James Morris <[email protected]>
 * Copyright (C) 2001 Silicon Graphics, Inc. (Trust Technology Group)
 * Copyright (C) 2015 Intel Corporation.
 * Copyright (C) 2015 Casey Schaufler <[email protected]>
 * Copyright (C) 2016 Mellanox Techonologies
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    Due to this file being licensed under the GPL there is controversy over
 *    whether this permits you to write a module that #includes this file
 *    without placing your module under the GPL.  Please consult a lawyer for
 *    advice before doing this.
 *
 */

#ifndef __LINUX_LSM_HOOKS_H
#define __LINUX_LSM_HOOKS_H

#include <linux/security.h>
#include <linux/init.h>
#include <linux/rculist.h>

union security_list_options {
    #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__);
    #include "lsm_hook_defs.h"
    #undef LSM_HOOK
};

struct security_hook_heads {
    #define LSM_HOOK(RET, DEFAULT, NAME, ...) struct hlist_head NAME;
    #include "lsm_hook_defs.h"
    #undef LSM_HOOK
} __randomize_layout;

/*
 * Information that identifies a security module.
 */
struct lsm_id {
    const char    *lsm;        /* Name of the LSM */
    int        id;        /* LSM ID */
    int        features;    /* Set of LSM features */
    int        slot;        /* Slot in lsmblob if allocated */
};

/*
 * Security module hook list structure.
 * For use with generic list macros for common operations.
 */
struct security_hook_list {
    struct hlist_node        list;
    struct hlist_head        *head;
    union security_list_options    hook;
    struct lsm_id            *lsmid;
} __randomize_layout;

/*
 * Security blob size or offset data.
 */
struct lsm_blob_sizes {
    int    lbs_cred;
    int    lbs_file;
    int    lbs_inode;
    int    lbs_sock;
    int    lbs_superblock;
    int    lbs_ipc;
    int    lbs_msg_msg;
    int    lbs_task;
};

/*
 * LSM_RET_VOID is used as the default value in LSM_HOOK definitions for void
 * LSM hooks (in include/linux/lsm_hook_defs.h).
 */
#define LSM_RET_VOID ((void) 0)

/*
 * Initializing a security_hook_list structure takes
 * up a lot of space in a source file. This macro takes
 * care of the common case and reduces the amount of
 * text involved.
 */
#define LSM_HOOK_INIT(HEAD, HOOK) \
    { .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } }

extern struct security_hook_heads security_hook_heads;
extern char *lsm_names;

extern void security_add_hooks(struct security_hook_list *hooks, int count,
                   struct lsm_id *lsmid);

#define LSM_FLAG_LEGACY_MAJOR    BIT(0)
#define LSM_FLAG_EXCLUSIVE    BIT(1)

enum lsm_order {
    LSM_ORDER_FIRST = -1,    /* This is only for capabilities. */
    LSM_ORDER_MUTABLE = 0,
    LSM_ORDER_LAST = 1,    /* This is only for integrity. */
};

struct lsm_info {
    const char *name;    /* Required. */
    enum lsm_order order;    /* Optional: default is LSM_ORDER_MUTABLE */
    unsigned long flags;    /* Optional: flags describing LSM */
    int *enabled;        /* Optional: controlled by CONFIG_LSM */
    int (*init)(void);    /* Required. */
    struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
};

extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[];

#define DEFINE_LSM(lsm)                            \
    static struct lsm_info __lsm_##lsm                \
        __used __section(".lsm_info.init")            \
        __aligned(sizeof(unsigned long))

#define DEFINE_EARLY_LSM(lsm)                        \
    static struct lsm_info __early_lsm_##lsm            \
        __used __section(".early_lsm_info.init")        \
        __aligned(sizeof(unsigned long))

extern int lsm_inode_alloc(struct inode *inode);

#endif /* ! __LINUX_LSM_HOOKS_H */