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/fs.h>
  23 #include <linux/security.h>
  24 #include <linux/hash.h>
  25 #include <linux/tpm.h>
  26 #include <linux/audit.h>
  27 #include <crypto/hash_info.h>
  28
  29 #include "../integrity.h"
  30
  31 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
  32                      IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
  33 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
  34
  35 /* digest size for IMA, fits SHA1 or MD5 */
  36 #define IMA_DIGEST_SIZE         SHA1_DIGEST_SIZE
  37 #define IMA_EVENT_NAME_LEN_MAX  255
  38
  39 #define IMA_HASH_BITS 9
  40 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
  41
  42 #define IMA_TEMPLATE_FIELD_ID_MAX_LEN   16
  43 #define IMA_TEMPLATE_NUM_FIELDS_MAX     15
  44
  45 #define IMA_TEMPLATE_IMA_NAME "ima"
  46 #define IMA_TEMPLATE_IMA_FMT "d|n"
  47
  48 /* current content of the policy */
  49 extern int ima_policy_flag;
  50
  51 /* set during initialization */
  52 extern int ima_initialized;
  53 extern int ima_used_chip;
  54 extern int ima_hash_algo;
  55 extern int ima_appraise;
  56
  57 /* IMA event related data */
  58 struct ima_event_data {
  59         struct integrity_iint_cache *iint;
  60         struct file *file;
  61         const unsigned char *filename;
  62         struct evm_ima_xattr_data *xattr_value;
  63         int xattr_len;
  64         const char *violation;
  65 };
  66
  67 /* IMA template field data definition */
  68 struct ima_field_data {
  69         u8 *data;
  70         u32 len;
  71 };
  72
  73 /* IMA template field definition */
  74 struct ima_template_field {
  75         const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
  76         int (*field_init)(struct ima_event_data *event_data,
  77                           struct ima_field_data *field_data);
  78         void (*field_show)(struct seq_file *m, enum ima_show_type show,
  79                            struct ima_field_data *field_data);
  80 };
  81
  82 /* IMA template descriptor definition */
  83 struct ima_template_desc {
  84         char *name;
  85         char *fmt;
  86         int num_fields;
  87         struct ima_template_field **fields;
  88 };
  89
  90 struct ima_template_entry {
  91         u8 digest[TPM_DIGEST_SIZE];     /* sha1 or md5 measurement hash */
  92         struct ima_template_desc *template_desc; /* template descriptor */
  93         u32 template_data_len;
  94         struct ima_field_data template_data[0]; /* template related data */
  95 };
  96
  97 struct ima_queue_entry {
  98         struct hlist_node hnext;        /* place in hash collision list */
  99         struct list_head later;         /* place in ima_measurements list */
 100         struct ima_template_entry *entry;
 101 };
 102 extern struct list_head ima_measurements;       /* list of all measurements */
 103
 104 /* Internal IMA function definitions */
 105 int ima_init(void);
 106 int ima_fs_init(void);
 107 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 108                            const char *op, struct inode *inode,
 109                            const unsigned char *filename);
 110 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
 111 int ima_calc_buffer_hash(const void *buf, loff_t len,
 112                          struct ima_digest_data *hash);
 113 int ima_calc_field_array_hash(struct ima_field_data *field_data,
 114                               struct ima_template_desc *desc, int num_fields,
 115                               struct ima_digest_data *hash);
 116 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 117 void ima_add_violation(struct file *file, const unsigned char *filename,
 118                        struct integrity_iint_cache *iint,
 119                        const char *op, const char *cause);
 120 int ima_init_crypto(void);
 121 void ima_putc(struct seq_file *m, void *data, int datalen);
 122 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
 123 struct ima_template_desc *ima_template_desc_current(void);
 124 int ima_init_template(void);
 125
 126 /*
 127  * used to protect h_table and sha_table
 128  */
 129 extern spinlock_t ima_queue_lock;
 130
 131 struct ima_h_table {
 132         atomic_long_t len;      /* number of stored measurements in the list */
 133         atomic_long_t violations;
 134         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
 135 };
 136 extern struct ima_h_table ima_htable;
 137
 138 static inline unsigned long ima_hash_key(u8 *digest)
 139 {
 140         return hash_long(*digest, IMA_HASH_BITS);
 141 }
 142
 143 enum ima_hooks {
 144         FILE_CHECK = 1,
 145         MMAP_CHECK,
 146         BPRM_CHECK,
 147         POST_SETATTR,
 148         MODULE_CHECK,
 149         FIRMWARE_CHECK,
 150         KEXEC_KERNEL_CHECK,
 151         KEXEC_INITRAMFS_CHECK,
 152         POLICY_CHECK,
 153         MAX_CHECK
 154 };
 155
 156 /* LIM API function definitions */
 157 int ima_get_action(struct inode *inode, int mask, enum ima_hooks func);
 158 int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
 159 int ima_collect_measurement(struct integrity_iint_cache *iint,
 160                             struct file *file, void *buf, loff_t size,
 161                             enum hash_algo algo);
 162 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 163                            const unsigned char *filename,
 164                            struct evm_ima_xattr_data *xattr_value,
 165                            int xattr_len);
 166 void ima_audit_measurement(struct integrity_iint_cache *iint,
 167                            const unsigned char *filename);
 168 int ima_alloc_init_template(struct ima_event_data *event_data,
 169                             struct ima_template_entry **entry);
 170 int ima_store_template(struct ima_template_entry *entry, int violation,
 171                        struct inode *inode, const unsigned char *filename);
 172 void ima_free_template_entry(struct ima_template_entry *entry);
 173 const char *ima_d_path(struct path *path, char **pathbuf);
 174
 175 /* IMA policy related functions */
 176 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 177                      int flags);
 178 void ima_init_policy(void);
 179 void ima_update_policy(void);
 180 void ima_update_policy_flag(void);
 181 ssize_t ima_parse_add_rule(char *);
 182 void ima_delete_rules(void);
 183 int ima_check_policy(void);
 184 void *ima_policy_start(struct seq_file *m, loff_t *pos);
 185 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
 186 void ima_policy_stop(struct seq_file *m, void *v);
 187 int ima_policy_show(struct seq_file *m, void *v);
 188
 189 /* Appraise integrity measurements */
 190 #define IMA_APPRAISE_ENFORCE    0x01
 191 #define IMA_APPRAISE_FIX        0x02
 192 #define IMA_APPRAISE_LOG        0x04
 193 #define IMA_APPRAISE_MODULES    0x08
 194 #define IMA_APPRAISE_FIRMWARE   0x10
 195 #define IMA_APPRAISE_POLICY     0x20
 196
 197 #ifdef CONFIG_IMA_APPRAISE
 198 int ima_appraise_measurement(enum ima_hooks func,
 199                              struct integrity_iint_cache *iint,
 200                              struct file *file, const unsigned char *filename,
 201                              struct evm_ima_xattr_data *xattr_value,
 202                              int xattr_len, int opened);
 203 int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
 204 void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
 205 enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 206                                            enum ima_hooks func);
 207 enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 208                                  int xattr_len);
 209 int ima_read_xattr(struct dentry *dentry,
 210                    struct evm_ima_xattr_data **xattr_value);
 211
 212 #else
 213 static inline int ima_appraise_measurement(enum ima_hooks func,
 214                                            struct integrity_iint_cache *iint,
 215                                            struct file *file,
 216                                            const unsigned char *filename,
 217                                            struct evm_ima_xattr_data *xattr_value,
 218                                            int xattr_len, int opened)
 219 {
 220         return INTEGRITY_UNKNOWN;
 221 }
 222
 223 static inline int ima_must_appraise(struct inode *inode, int mask,
 224                                     enum ima_hooks func)
 225 {
 226         return 0;
 227 }
 228
 229 static inline void ima_update_xattr(struct integrity_iint_cache *iint,
 230                                     struct file *file)
 231 {
 232 }
 233
 234 static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache
 235                                                          *iint,
 236                                                          enum ima_hooks func)
 237 {
 238         return INTEGRITY_UNKNOWN;
 239 }
 240
 241 static inline enum hash_algo
 242 ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
 243 {
 244         return ima_hash_algo;
 245 }
 246
 247 static inline int ima_read_xattr(struct dentry *dentry,
 248                                  struct evm_ima_xattr_data **xattr_value)
 249 {
 250         return 0;
 251 }
 252
 253 #endif
 254
 255 /* LSM based policy rules require audit */
 256 #ifdef CONFIG_IMA_LSM_RULES
 257
 258 #define security_filter_rule_init security_audit_rule_init
 259 #define security_filter_rule_match security_audit_rule_match
 260
 261 #else
 262
 263 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 264                                             void **lsmrule)
 265 {
 266         return -EINVAL;
 267 }
 268
 269 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 270                                              void *lsmrule,
 271                                              struct audit_context *actx)
 272 {
 273         return -EINVAL;
 274 }
 275 #endif /* CONFIG_IMA_TRUSTED_KEYRING */
 276
 277 #ifdef  CONFIG_IMA_READ_POLICY
 278 #define POLICY_FILE_FLAGS       (S_IWUSR | S_IRUSR)
 279 #else
 280 #define POLICY_FILE_FLAGS       S_IWUSR
 281 #endif /* CONFIG_IMA_WRITE_POLICY */
 282
 283 #endif /* __LINUX_IMA_H */