security/integrity/ima/ima.h

   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 /* Internal IMA function definitions */
  66 int ima_init(void);
  67 void ima_cleanup(void);
  68 int ima_fs_init(void);
  69 void ima_fs_cleanup(void);
  70 int ima_inode_alloc(struct inode *inode);
  71 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
  72                            const char *op, struct inode *inode);
  73 int ima_calc_file_hash(struct file *file, char *digest);
  74 int ima_calc_buffer_hash(const void *data, int len, char *digest);
  75 int ima_calc_boot_aggregate(char *digest);
  76 void ima_add_violation(struct inode *inode, const unsigned char *filename,
  77                        const char *op, const char *cause);
  78 int ima_init_crypto(void);
  79
  80 /*
  81  * used to protect h_table and sha_table
  82  */
  83 extern spinlock_t ima_queue_lock;
  84
  85 struct ima_h_table {
  86         atomic_long_t len;      /* number of stored measurements in the list */
  87         atomic_long_t violations;
  88         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
  89 };
  90 extern struct ima_h_table ima_htable;
  91
  92 static inline unsigned long ima_hash_key(u8 *digest)
  93 {
  94         return hash_long(*digest, IMA_HASH_BITS);
  95 }
  96
  97 /* LIM API function definitions */
  98 int ima_get_action(struct inode *inode, int mask, int function);
  99 int ima_must_measure(struct inode *inode, int mask, int function);
 100 int ima_collect_measurement(struct integrity_iint_cache *iint,
 101                             struct file *file);
 102 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 103                            const unsigned char *filename);
 104 void ima_audit_measurement(struct integrity_iint_cache *iint,
 105                            const unsigned char *filename);
 106 int ima_store_template(struct ima_template_entry *entry, int violation,
 107                        struct inode *inode);
 108 void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show);
 109 const char *ima_d_path(struct path *path, char **pathbuf);
 110
 111 /* rbtree tree calls to lookup, insert, delete
 112  * integrity data associated with an inode.
 113  */
 114 struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
 115 struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
 116
 117 /* IMA policy related functions */
 118 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, POST_SETATTR };
 119
 120 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 121                      int flags);
 122 void ima_init_policy(void);
 123 void ima_update_policy(void);
 124 ssize_t ima_parse_add_rule(char *);
 125 void ima_delete_rules(void);
 126
 127 /* Appraise integrity measurements */
 128 #define IMA_APPRAISE_ENFORCE    0x01
 129 #define IMA_APPRAISE_FIX        0x02
 130 #define IMA_APPRAISE_MODULES    0x04
 131
 132 #ifdef CONFIG_IMA_APPRAISE
 133 int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
 134                              struct file *file, const unsigned char *filename);
 135 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
 136 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 137 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 138                                            int func);
 139
 140 #else
 141 static inline int ima_appraise_measurement(int func,
 142                                            struct integrity_iint_cache *iint,
 143                                            struct file *file,
 144                                            const unsigned char *filename)
 145 {
 146         return INTEGRITY_UNKNOWN;
 147 }
 148
 149 static inline int ima_must_appraise(struct inode *inode, int mask,
 150                                     enum ima_hooks func)
 151 {
 152         return 0;
 153 }
 154
 155 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
 156                                     struct file *file)
 157 {
 158 }
 159
 160 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
 161                                                          *iint, int func)
 162 {
 163         return INTEGRITY_UNKNOWN;
 164 }
 165 #endif
 166
 167 /* LSM based policy rules require audit */
 168 #ifdef CONFIG_IMA_LSM_RULES
 169
 170 #define security_filter_rule_init security_audit_rule_init
 171 #define security_filter_rule_match security_audit_rule_match
 172
 173 #else
 174
 175 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 176                                             void **lsmrule)
 177 {
 178         return -EINVAL;
 179 }
 180
 181 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 182                                              void *lsmrule,
 183                                              struct audit_context *actx)
 184 {
 185         return -EINVAL;
 186 }
 187 #endif /* CONFIG_IMA_LSM_RULES */
 188 #endif