xref: /linux/include/linux/lsm_hooks.h (revision 84b9b44b)
1 /*
2  * Linux Security Module interfaces
3  *
4  * Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
5  * Copyright (C) 2001 Greg Kroah-Hartman <greg@kroah.com>
6  * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
7  * Copyright (C) 2001 James Morris <jmorris@intercode.com.au>
8  * Copyright (C) 2001 Silicon Graphics, Inc. (Trust Technology Group)
9  * Copyright (C) 2015 Intel Corporation.
10  * Copyright (C) 2015 Casey Schaufler <casey@schaufler-ca.com>
11  * Copyright (C) 2016 Mellanox Techonologies
12  *
13  *	This program is free software; you can redistribute it and/or modify
14  *	it under the terms of the GNU General Public License as published by
15  *	the Free Software Foundation; either version 2 of the License, or
16  *	(at your option) any later version.
17  *
18  *	Due to this file being licensed under the GPL there is controversy over
19  *	whether this permits you to write a module that #includes this file
20  *	without placing your module under the GPL.  Please consult a lawyer for
21  *	advice before doing this.
22  *
23  */
24 
25 #ifndef __LINUX_LSM_HOOKS_H
26 #define __LINUX_LSM_HOOKS_H
27 
28 #include <linux/security.h>
29 #include <linux/init.h>
30 #include <linux/rculist.h>
31 
32 union security_list_options {
33 	#define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__);
34 	#include "lsm_hook_defs.h"
35 	#undef LSM_HOOK
36 };
37 
38 struct security_hook_heads {
39 	#define LSM_HOOK(RET, DEFAULT, NAME, ...) struct hlist_head NAME;
40 	#include "lsm_hook_defs.h"
41 	#undef LSM_HOOK
42 } __randomize_layout;
43 
44 /*
45  * Security module hook list structure.
46  * For use with generic list macros for common operations.
47  */
48 struct security_hook_list {
49 	struct hlist_node		list;
50 	struct hlist_head		*head;
51 	union security_list_options	hook;
52 	const char			*lsm;
53 } __randomize_layout;
54 
55 /*
56  * Security blob size or offset data.
57  */
58 struct lsm_blob_sizes {
59 	int	lbs_cred;
60 	int	lbs_file;
61 	int	lbs_inode;
62 	int	lbs_superblock;
63 	int	lbs_ipc;
64 	int	lbs_msg_msg;
65 	int	lbs_task;
66 };
67 
68 /*
69  * LSM_RET_VOID is used as the default value in LSM_HOOK definitions for void
70  * LSM hooks (in include/linux/lsm_hook_defs.h).
71  */
72 #define LSM_RET_VOID ((void) 0)
73 
74 /*
75  * Initializing a security_hook_list structure takes
76  * up a lot of space in a source file. This macro takes
77  * care of the common case and reduces the amount of
78  * text involved.
79  */
80 #define LSM_HOOK_INIT(HEAD, HOOK) \
81 	{ .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } }
82 
83 extern struct security_hook_heads security_hook_heads;
84 extern char *lsm_names;
85 
86 extern void security_add_hooks(struct security_hook_list *hooks, int count,
87 				const char *lsm);
88 
89 #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
90 #define LSM_FLAG_EXCLUSIVE	BIT(1)
91 
92 enum lsm_order {
93 	LSM_ORDER_FIRST = -1,	/* This is only for capabilities. */
94 	LSM_ORDER_MUTABLE = 0,
95 	LSM_ORDER_LAST = 1,	/* This is only for integrity. */
96 };
97 
98 struct lsm_info {
99 	const char *name;	/* Required. */
100 	enum lsm_order order;	/* Optional: default is LSM_ORDER_MUTABLE */
101 	unsigned long flags;	/* Optional: flags describing LSM */
102 	int *enabled;		/* Optional: controlled by CONFIG_LSM */
103 	int (*init)(void);	/* Required. */
104 	struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
105 };
106 
107 extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
108 extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[];
109 
110 #define DEFINE_LSM(lsm)							\
111 	static struct lsm_info __lsm_##lsm				\
112 		__used __section(".lsm_info.init")			\
113 		__aligned(sizeof(unsigned long))
114 
115 #define DEFINE_EARLY_LSM(lsm)						\
116 	static struct lsm_info __early_lsm_##lsm			\
117 		__used __section(".early_lsm_info.init")		\
118 		__aligned(sizeof(unsigned long))
119 
120 extern int lsm_inode_alloc(struct inode *inode);
121 
122 #endif /* ! __LINUX_LSM_HOOKS_H */
123