xref: /openbmc/linux/security/integrity/ima/ima.h (revision 1dd24dae)
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_file_hash(struct file *file, char *digest);
88 int ima_calc_buffer_hash(const void *data, int len, 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 int ima_init_crypto(void);
93 
94 /*
95  * used to protect h_table and sha_table
96  */
97 extern spinlock_t ima_queue_lock;
98 
99 struct ima_h_table {
100 	atomic_long_t len;	/* number of stored measurements in the list */
101 	atomic_long_t violations;
102 	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
103 };
104 extern struct ima_h_table ima_htable;
105 
106 static inline unsigned long ima_hash_key(u8 *digest)
107 {
108 	return hash_long(*digest, IMA_HASH_BITS);
109 }
110 
111 /* LIM API function definitions */
112 int ima_get_action(struct inode *inode, int mask, int function);
113 int ima_must_measure(struct inode *inode, int mask, int function);
114 int ima_collect_measurement(struct integrity_iint_cache *iint,
115 			    struct file *file);
116 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
117 			   const unsigned char *filename);
118 void ima_audit_measurement(struct integrity_iint_cache *iint,
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, enum ima_show_type show);
123 const char *ima_d_path(struct path *path, char **pathbuf);
124 
125 /* rbtree tree calls to lookup, insert, delete
126  * integrity data associated with an inode.
127  */
128 struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
129 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
130 
131 /* IMA policy related functions */
132 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, POST_SETATTR };
133 
134 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
135 		     int flags);
136 void ima_init_policy(void);
137 void ima_update_policy(void);
138 ssize_t ima_parse_add_rule(char *);
139 void ima_delete_rules(void);
140 
141 /* Appraise integrity measurements */
142 #define IMA_APPRAISE_ENFORCE	0x01
143 #define IMA_APPRAISE_FIX	0x02
144 #define IMA_APPRAISE_MODULES	0x04
145 
146 #ifdef CONFIG_IMA_APPRAISE
147 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
148 			     struct file *file, const unsigned char *filename);
149 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
150 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
151 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
152 					   int func);
153 
154 #else
155 static inline int ima_appraise_measurement(int func,
156 					   struct integrity_iint_cache *iint,
157 					   struct file *file,
158 					   const unsigned char *filename)
159 {
160 	return INTEGRITY_UNKNOWN;
161 }
162 
163 static inline int ima_must_appraise(struct inode *inode, int mask,
164 				    enum ima_hooks func)
165 {
166 	return 0;
167 }
168 
169 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
170 				    struct file *file)
171 {
172 }
173 
174 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
175 							 *iint, int func)
176 {
177 	return INTEGRITY_UNKNOWN;
178 }
179 #endif
180 
181 /* LSM based policy rules require audit */
182 #ifdef CONFIG_IMA_LSM_RULES
183 
184 #define security_filter_rule_init security_audit_rule_init
185 #define security_filter_rule_match security_audit_rule_match
186 
187 #else
188 
189 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
190 					    void **lsmrule)
191 {
192 	return -EINVAL;
193 }
194 
195 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
196 					     void *lsmrule,
197 					     struct audit_context *actx)
198 {
199 	return -EINVAL;
200 }
201 #endif /* CONFIG_IMA_LSM_RULES */
202 #endif
203