xref: /linux/security/integrity/ima/ima.h (revision bab739378758a1e2b2d7ddcee7bc06cf4c591c3c)
1 /*
2  * Copyright (C) 2005,2006,2007,2008 IBM Corporation
3  *
4  * Authors:
5  * Reiner Sailer <sailer@watson.ibm.com>
6  * Mimi Zohar <zohar@us.ibm.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation, version 2 of the
11  * License.
12  *
13  * File: ima.h
14  *	internal Integrity Measurement Architecture (IMA) definitions
15  */
16 
17 #ifndef __LINUX_IMA_H
18 #define __LINUX_IMA_H
19 
20 #include <linux/types.h>
21 #include <linux/crypto.h>
22 #include <linux/security.h>
23 #include <linux/hash.h>
24 #include <linux/tpm.h>
25 #include <linux/audit.h>
26 
27 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
28 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
29 
30 /* digest size for IMA, fits SHA1 or MD5 */
31 #define IMA_DIGEST_SIZE		20
32 #define IMA_EVENT_NAME_LEN_MAX	255
33 
34 #define IMA_HASH_BITS 9
35 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
36 
37 /* set during initialization */
38 extern int ima_initialized;
39 extern int ima_used_chip;
40 extern char *ima_hash;
41 
42 /* IMA inode template definition */
43 struct ima_template_data {
44 	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
45 	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
46 };
47 
48 struct ima_template_entry {
49 	u8 digest[IMA_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
50 	char *template_name;
51 	int template_len;
52 	struct ima_template_data template;
53 };
54 
55 struct ima_queue_entry {
56 	struct hlist_node hnext;	/* place in hash collision list */
57 	struct list_head later;		/* place in ima_measurements list */
58 	struct ima_template_entry *entry;
59 };
60 extern struct list_head ima_measurements;	/* list of all measurements */
61 
62 /* declarations */
63 void integrity_audit_msg(int audit_msgno, struct inode *inode,
64 			 const unsigned char *fname, const char *op,
65 			 const char *cause, int result, int info);
66 
67 /* Internal IMA function definitions */
68 void ima_iintcache_init(void);
69 int ima_init(void);
70 void ima_cleanup(void);
71 int ima_fs_init(void);
72 void ima_fs_cleanup(void);
73 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
74 			   const char *op, struct inode *inode);
75 int ima_calc_hash(struct file *file, char *digest);
76 int ima_calc_template_hash(int template_len, void *template, char *digest);
77 int ima_calc_boot_aggregate(char *digest);
78 void ima_add_violation(struct inode *inode, const unsigned char *filename,
79 		       const char *op, const char *cause);
80 
81 /*
82  * used to protect h_table and sha_table
83  */
84 extern spinlock_t ima_queue_lock;
85 
86 struct ima_h_table {
87 	atomic_long_t len;	/* number of stored measurements in the list */
88 	atomic_long_t violations;
89 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
90 };
91 extern struct ima_h_table ima_htable;
92 
93 static inline unsigned long ima_hash_key(u8 *digest)
94 {
95 	return hash_long(*digest, IMA_HASH_BITS);
96 }
97 
98 /* iint cache flags */
99 #define IMA_MEASURED		1
100 
101 /* integrity data associated with an inode */
102 struct ima_iint_cache {
103 	u64 version;		/* track inode changes */
104 	unsigned long flags;
105 	u8 digest[IMA_DIGEST_SIZE];
106 	struct mutex mutex;	/* protects: version, flags, digest */
107 	long readcount;		/* measured files readcount */
108 	long writecount;	/* measured files writecount */
109 	struct kref refcount;	/* ima_iint_cache reference count */
110 	struct rcu_head rcu;
111 };
112 
113 /* LIM API function definitions */
114 int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
115 		     int mask, int function);
116 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
117 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
118 			   const unsigned char *filename);
119 int ima_store_template(struct ima_template_entry *entry, int violation,
120 		       struct inode *inode);
121 void ima_template_show(struct seq_file *m, void *e,
122 		       enum ima_show_type show);
123 
124 /* radix tree calls to lookup, insert, delete
125  * integrity data associated with an inode.
126  */
127 struct ima_iint_cache *ima_iint_insert(struct inode *inode);
128 struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
129 struct ima_iint_cache *ima_iint_find_insert_get(struct inode *inode);
130 void ima_iint_delete(struct inode *inode);
131 void iint_free(struct kref *kref);
132 void iint_rcu_free(struct rcu_head *rcu);
133 
134 /* IMA policy related functions */
135 enum ima_hooks { PATH_CHECK = 1, FILE_MMAP, BPRM_CHECK };
136 
137 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
138 void ima_init_policy(void);
139 void ima_update_policy(void);
140 #endif
141