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