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