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 /* current content of the policy */
  47 extern int ima_policy_flag;
  48
  49 /* set during initialization */
  50 extern int ima_initialized;
  51 extern int ima_used_chip;
  52 extern int ima_hash_algo;
  53 extern int ima_appraise;
  54
  55 /* IMA event related data */
  56 struct ima_event_data {
  57         struct integrity_iint_cache *iint;
  58         struct file *file;
  59         const unsigned char *filename;
  60         struct evm_ima_xattr_data *xattr_value;
  61         int xattr_len;
  62         const char *violation;
  63 };
  64
  65 /* IMA template field data definition */
  66 struct ima_field_data {
  67         u8 *data;
  68         u32 len;
  69 };
  70
  71 /* IMA template field definition */
  72 struct ima_template_field {
  73         const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
  74         int (*field_init)(struct ima_event_data *event_data,
  75                           struct ima_field_data *field_data);
  76         void (*field_show)(struct seq_file *m, enum ima_show_type show,
  77                            struct ima_field_data *field_data);
  78 };
  79
  80 /* IMA template descriptor definition */
  81 struct ima_template_desc {
  82         char *name;
  83         char *fmt;
  84         int num_fields;
  85         struct ima_template_field **fields;
  86 };
  87
  88 struct ima_template_entry {
  89         u8 digest[TPM_DIGEST_SIZE];     /* sha1 or md5 measurement hash */
  90         struct ima_template_desc *template_desc; /* template descriptor */
  91         u32 template_data_len;
  92         struct ima_field_data template_data[0]; /* template related data */
  93 };
  94
  95 struct ima_queue_entry {
  96         struct hlist_node hnext;        /* place in hash collision list */
  97         struct list_head later;         /* place in ima_measurements list */
  98         struct ima_template_entry *entry;
  99 };
 100 extern struct list_head ima_measurements;       /* list of all measurements */
 101
 102 /* Internal IMA function definitions */
 103 int ima_init(void);
 104 int ima_fs_init(void);
 105 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 106                            const char *op, struct inode *inode,
 107                            const unsigned char *filename);
 108 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
 109 int ima_calc_field_array_hash(struct ima_field_data *field_data,
 110                               struct ima_template_desc *desc, int num_fields,
 111                               struct ima_digest_data *hash);
 112 int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 113 void ima_add_violation(struct file *file, const unsigned char *filename,
 114                        struct integrity_iint_cache *iint,
 115                        const char *op, const char *cause);
 116 int ima_init_crypto(void);
 117 void ima_putc(struct seq_file *m, void *data, int datalen);
 118 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
 119 struct ima_template_desc *ima_template_desc_current(void);
 120 int ima_init_template(void);
 121
 122 /*
 123  * used to protect h_table and sha_table
 124  */
 125 extern spinlock_t ima_queue_lock;
 126
 127 struct ima_h_table {
 128         atomic_long_t len;      /* number of stored measurements in the list */
 129         atomic_long_t violations;
 130         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
 131 };
 132 extern struct ima_h_table ima_htable;
 133
 134 static inline unsigned long ima_hash_key(u8 *digest)
 135 {
 136         return hash_long(*digest, IMA_HASH_BITS);
 137 }
 138
 139 /* LIM API function definitions */
 140 int ima_get_action(struct inode *inode, int mask, int function);
 141 int ima_must_measure(struct inode *inode, int mask, int function);
 142 int ima_collect_measurement(struct integrity_iint_cache *iint,
 143                             struct file *file,
 144                             struct evm_ima_xattr_data **xattr_value,
 145                             int *xattr_len);
 146 void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
 147                            const unsigned char *filename,
 148                            struct evm_ima_xattr_data *xattr_value,
 149                            int xattr_len);
 150 void ima_audit_measurement(struct integrity_iint_cache *iint,
 151                            const unsigned char *filename);
 152 int ima_alloc_init_template(struct ima_event_data *event_data,
 153                             struct ima_template_entry **entry);
 154 int ima_store_template(struct ima_template_entry *entry, int violation,
 155                        struct inode *inode, const unsigned char *filename);
 156 void ima_free_template_entry(struct ima_template_entry *entry);
 157 const char *ima_d_path(struct path *path, char **pathbuf);
 158
 159 /* IMA policy related functions */
 160 enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, FIRMWARE_CHECK, POST_SETATTR };
 161
 162 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
 163                      int flags);
 164 void ima_init_policy(void);
 165 void ima_update_policy(void);
 166 void ima_update_policy_flag(void);
 167 ssize_t ima_parse_add_rule(char *);
 168 void ima_delete_rules(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 void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
 191                        struct ima_digest_data *hash);
 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 void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 224                                      int xattr_len,
 225                                      struct ima_digest_data *hash)
 226 {
 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 */