xref: /linux/security/integrity/ima/ima.h (revision 71901cc4109b3794b863884e348aff3c71e693cc)
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 iint_initialized;
39 extern int ima_initialized;
40 extern int ima_used_chip;
41 extern char *ima_hash;
42 
43 /* IMA inode template definition */
44 struct ima_template_data {
45 	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
46 	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
47 };
48 
49 struct ima_template_entry {
50 	u8 digest[IMA_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
51 	const char *template_name;
52 	int template_len;
53 	struct ima_template_data template;
54 };
55 
56 struct ima_queue_entry {
57 	struct hlist_node hnext;	/* place in hash collision list */
58 	struct list_head later;		/* place in ima_measurements list */
59 	struct ima_template_entry *entry;
60 };
61 extern struct list_head ima_measurements;	/* list of all measurements */
62 
63 /* declarations */
64 void integrity_audit_msg(int audit_msgno, struct inode *inode,
65 			 const unsigned char *fname, const char *op,
66 			 const char *cause, int result, int info);
67 
68 /* Internal IMA function definitions */
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 	long opencount;		/* opens reference count */
110 	struct kref refcount;	/* ima_iint_cache reference count */
111 	struct rcu_head rcu;
112 };
113 
114 /* LIM API function definitions */
115 int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
116 		     int mask, int function);
117 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
118 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
119 			   const unsigned char *filename);
120 int ima_store_template(struct ima_template_entry *entry, int violation,
121 		       struct inode *inode);
122 void ima_template_show(struct seq_file *m, void *e,
123 		       enum ima_show_type show);
124 
125 /* radix tree calls to lookup, insert, delete
126  * integrity data associated with an inode.
127  */
128 struct ima_iint_cache *ima_iint_insert(struct inode *inode);
129 struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
130 void iint_free(struct kref *kref);
131 void iint_rcu_free(struct rcu_head *rcu);
132 
133 /* IMA policy related functions */
134 enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };
135 
136 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
137 void ima_init_policy(void);
138 void ima_update_policy(void);
139 ssize_t ima_parse_add_rule(char *);
140 void ima_delete_rules(void);
141 
142 /* LSM based policy rules require audit */
143 #ifdef CONFIG_IMA_LSM_RULES
144 
145 #define security_filter_rule_init security_audit_rule_init
146 #define security_filter_rule_match security_audit_rule_match
147 
148 #else
149 
150 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
151 					    void **lsmrule)
152 {
153 	return -EINVAL;
154 }
155 
156 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
157 					     void *lsmrule,
158 					     struct audit_context *actx)
159 {
160 	return -EINVAL;
161 }
162 #endif /* CONFIG_IMA_LSM_RULES */
163 #endif
164