aboutsummaryrefslogtreecommitdiffstats
path: root/security/integrity/ima/ima.h
blob: f7af0110bcde3a65555d3cfd4ae4d9c901391f49 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer <sailer@watson.ibm.com>
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * 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, version 2 of the
 * License.
 *
 * File: ima.h
 *	internal Integrity Measurement Architecture (IMA) definitions
 */

#ifndef __LINUX_IMA_H
#define __LINUX_IMA_H

#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/security.h>
#include <linux/hash.h>
#include <linux/tpm.h>
#include <linux/audit.h>

enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };

/* digest size for IMA, fits SHA1 or MD5 */
#define IMA_DIGEST_SIZE		20
#define IMA_EVENT_NAME_LEN_MAX	255

#define IMA_HASH_BITS 9
#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)

/* set during initialization */
extern int iint_initialized;
extern int ima_initialized;
extern int ima_used_chip;
extern char *ima_hash;

/* IMA inode template definition */
struct ima_template_data {
	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
};

struct ima_template_entry {
	u8 digest[IMA_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
	const char *template_name;
	int template_len;
	struct ima_template_data template;
};

struct ima_queue_entry {
	struct hlist_node hnext;	/* place in hash collision list */
	struct list_head later;		/* place in ima_measurements list */
	struct ima_template_entry *entry;
};
extern struct list_head ima_measurements;	/* list of all measurements */

/* declarations */
void integrity_audit_msg(int audit_msgno, struct inode *inode,
			 const unsigned char *fname, const char *op,
			 const char *cause, int result, int info);

/* Internal IMA function definitions */
int ima_init(void);
void ima_cleanup(void);
int ima_fs_init(void);
void ima_fs_cleanup(void);
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
			   const char *op, struct inode *inode);
int ima_calc_hash(struct file *file, char *digest);
int ima_calc_template_hash(int template_len, void *template, char *digest);
int ima_calc_boot_aggregate(char *digest);
void ima_add_violation(struct inode *inode, const unsigned char *filename,
		       const char *op, const char *cause);

/*
 * used to protect h_table and sha_table
 */
extern spinlock_t ima_queue_lock;

struct ima_h_table {
	atomic_long_t len;	/* number of stored measurements in the list */
	atomic_long_t violations;
	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
};
extern struct ima_h_table ima_htable;

static inline unsigned long ima_hash_key(u8 *digest)
{
	return hash_long(*digest, IMA_HASH_BITS);
}

/* iint cache flags */
#define IMA_MEASURED		0x01

/* integrity data associated with an inode */
struct ima_iint_cache {
	struct rb_node rb_node; /* rooted in ima_iint_tree */
	struct inode *inode;	/* back pointer to inode in question */
	u64 version;		/* track inode changes */
	unsigned char flags;
	u8 digest[IMA_DIGEST_SIZE];
	struct mutex mutex;	/* protects: version, flags, digest */
	unsigned int readcount;	/* measured files readcount */
	unsigned int writecount;/* measured files writecount */
	struct kref refcount;	/* ima_iint_cache reference count */
};

/* LIM API function definitions */
int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
		     int mask, int function);
int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
			   const unsigned char *filename);
int ima_store_template(struct ima_template_entry *entry, int violation,
		       struct inode *inode);
void ima_template_show(struct seq_file *m, void *e,
		       enum ima_show_type show);

/* rbtree tree calls to lookup, insert, delete
 * integrity data associated with an inode.
 */
struct ima_iint_cache *ima_iint_insert(struct inode *inode);
struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
void iint_free(struct kref *kref);

/* IMA policy related functions */
enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };

int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
void ima_init_policy(void);
void ima_update_policy(void);
ssize_t ima_parse_add_rule(char *);
void ima_delete_rules(void);

/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES

#define security_filter_rule_init security_audit_rule_init
#define security_filter_rule_match security_audit_rule_match

#else

static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
					    void **lsmrule)
{
	return -EINVAL;
}

static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
					     void *lsmrule,
					     struct audit_context *actx)
{
	return -EINVAL;
}
#endif /* CONFIG_IMA_LSM_RULES */
#endif