xref: /linux/security/integrity/ima/ima.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 #include "../integrity.h"
28 
29 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
30 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
31 
32 /* digest size for IMA, fits SHA1 or MD5 */
33 #define IMA_DIGEST_SIZE		SHA1_DIGEST_SIZE
34 #define IMA_EVENT_NAME_LEN_MAX	255
35 
36 #define IMA_HASH_BITS 9
37 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
38 
39 /* set during initialization */
40 extern int ima_initialized;
41 extern int ima_used_chip;
42 extern char *ima_hash;
43 extern int ima_appraise;
44 
45 /* IMA inode template definition */
46 struct ima_template_data {
47 	u8 digest[IMA_DIGEST_SIZE];	/* sha1/md5 measurement hash */
48 	char file_name[IMA_EVENT_NAME_LEN_MAX + 1];	/* name + \0 */
49 };
50 
51 struct ima_template_entry {
52 	u8 digest[IMA_DIGEST_SIZE];	/* sha1 or md5 measurement hash */
53 	const char *template_name;
54 	int template_len;
55 	struct ima_template_data template;
56 };
57 
58 struct ima_queue_entry {
59 	struct hlist_node hnext;	/* place in hash collision list */
60 	struct list_head later;		/* place in ima_measurements list */
61 	struct ima_template_entry *entry;
62 };
63 extern struct list_head ima_measurements;	/* list of all measurements */
64 
65 #ifdef CONFIG_IMA_AUDIT
66 /* declarations */
67 void integrity_audit_msg(int audit_msgno, struct inode *inode,
68 			 const unsigned char *fname, const char *op,
69 			 const char *cause, int result, int info);
70 #else
71 static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
72 				       const unsigned char *fname,
73 				       const char *op, const char *cause,
74 				       int result, int info)
75 {
76 }
77 #endif
78 
79 /* Internal IMA function definitions */
80 int ima_init(void);
81 void ima_cleanup(void);
82 int ima_fs_init(void);
83 void ima_fs_cleanup(void);
84 int ima_inode_alloc(struct inode *inode);
85 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
86 			   const char *op, struct inode *inode);
87 int ima_calc_hash(struct file *file, char *digest);
88 int ima_calc_template_hash(int template_len, void *template, char *digest);
89 int ima_calc_boot_aggregate(char *digest);
90 void ima_add_violation(struct inode *inode, const unsigned char *filename,
91 		       const char *op, const char *cause);
92 
93 /*
94  * used to protect h_table and sha_table
95  */
96 extern spinlock_t ima_queue_lock;
97 
98 struct ima_h_table {
99 	atomic_long_t len;	/* number of stored measurements in the list */
100 	atomic_long_t violations;
101 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
102 };
103 extern struct ima_h_table ima_htable;
104 
105 static inline unsigned long ima_hash_key(u8 *digest)
106 {
107 	return hash_long(*digest, IMA_HASH_BITS);
108 }
109 
110 /* LIM API function definitions */
111 int ima_get_action(struct inode *inode, int mask, int function);
112 int ima_must_measure(struct inode *inode, int mask, int function);
113 int ima_collect_measurement(struct integrity_iint_cache *iint,
114 			    struct file *file);
115 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
116 			   const unsigned char *filename);
117 void ima_audit_measurement(struct integrity_iint_cache *iint,
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, enum ima_show_type show);
122 
123 /* rbtree tree calls to lookup, insert, delete
124  * integrity data associated with an inode.
125  */
126 struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
127 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
128 
129 /* IMA policy related functions */
130 enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK, POST_SETATTR };
131 
132 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
133 		     int flags);
134 void ima_init_policy(void);
135 void ima_update_policy(void);
136 ssize_t ima_parse_add_rule(char *);
137 void ima_delete_rules(void);
138 
139 /* Appraise integrity measurements */
140 #define IMA_APPRAISE_ENFORCE	0x01
141 #define IMA_APPRAISE_FIX	0x02
142 
143 #ifdef CONFIG_IMA_APPRAISE
144 int ima_appraise_measurement(struct integrity_iint_cache *iint,
145 			     struct file *file, const unsigned char *filename);
146 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
147 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
148 
149 #else
150 static inline int ima_appraise_measurement(struct integrity_iint_cache *iint,
151 					   struct file *file,
152 					   const unsigned char *filename)
153 {
154 	return INTEGRITY_UNKNOWN;
155 }
156 
157 static inline int ima_must_appraise(struct inode *inode, int mask,
158 				    enum ima_hooks func)
159 {
160 	return 0;
161 }
162 
163 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
164 				    struct file *file)
165 {
166 }
167 #endif
168 
169 /* LSM based policy rules require audit */
170 #ifdef CONFIG_IMA_LSM_RULES
171 
172 #define security_filter_rule_init security_audit_rule_init
173 #define security_filter_rule_match security_audit_rule_match
174 
175 #else
176 
177 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
178 					    void **lsmrule)
179 {
180 	return -EINVAL;
181 }
182 
183 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
184 					     void *lsmrule,
185 					     struct audit_context *actx)
186 {
187 	return -EINVAL;
188 }
189 #endif /* CONFIG_IMA_LSM_RULES */
190 #endif
191