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 enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
  28 enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
  29
  30 /* digest size for IMA, fits SHA1 or MD5 */
  31 #define IMA_DIGEST_SIZE         20
  32 #define IMA_EVENT_NAME_LEN_MAX  255
  33
  34 #define IMA_HASH_BITS 9
  35 #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
  36
  37 /* set during initialization */
  38 extern int iint_initialized;
  39 extern int ima_initialized;
  40 extern int ima_used_chip;
  41 extern char *ima_hash;
  42
  43 /* IMA inode template definition */
  44 struct ima_template_data {
  45         u8 digest[IMA_DIGEST_SIZE];     /* sha1/md5 measurement hash */
  46         char file_name[IMA_EVENT_NAME_LEN_MAX + 1];     /* name + \0 */
  47 };
  48
  49 struct ima_template_entry {
  50         u8 digest[IMA_DIGEST_SIZE];     /* sha1 or md5 measurement hash */
  51         const char *template_name;
  52         int template_len;
  53         struct ima_template_data template;
  54 };
  55
  56 struct ima_queue_entry {
  57         struct hlist_node hnext;        /* place in hash collision list */
  58         struct list_head later;         /* place in ima_measurements list */
  59         struct ima_template_entry *entry;
  60 };
  61 extern struct list_head ima_measurements;       /* list of all measurements */
  62
  63 /* declarations */
  64 void integrity_audit_msg(int audit_msgno, struct inode *inode,
  65                          const unsigned char *fname, const char *op,
  66                          const char *cause, int result, int info);
  67
  68 /* Internal IMA function definitions */
  69 int ima_init(void);
  70 void ima_cleanup(void);
  71 int ima_fs_init(void);
  72 void ima_fs_cleanup(void);
  73 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
  74                            const char *op, struct inode *inode);
  75 int ima_calc_hash(struct file *file, char *digest);
  76 int ima_calc_template_hash(int template_len, void *template, char *digest);
  77 int ima_calc_boot_aggregate(char *digest);
  78 void ima_add_violation(struct inode *inode, const unsigned char *filename,
  79                        const char *op, const char *cause);
  80
  81 /*
  82  * used to protect h_table and sha_table
  83  */
  84 extern spinlock_t ima_queue_lock;
  85
  86 struct ima_h_table {
  87         atomic_long_t len;      /* number of stored measurements in the list */
  88         atomic_long_t violations;
  89         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
  90 };
  91 extern struct ima_h_table ima_htable;
  92
  93 static inline unsigned long ima_hash_key(u8 *digest)
  94 {
  95         return hash_long(*digest, IMA_HASH_BITS);
  96 }
  97
  98 /* iint cache flags */
  99 #define IMA_MEASURED            1
 100
 101 /* integrity data associated with an inode */
 102 struct ima_iint_cache {
 103         struct rb_node rb_node; /* rooted in ima_iint_tree */
 104         struct inode *inode;    /* back pointer to inode in question */
 105         u64 version;            /* track inode changes */
 106         unsigned long flags;
 107         u8 digest[IMA_DIGEST_SIZE];
 108         struct mutex mutex;     /* protects: version, flags, digest */
 109         unsigned int readcount; /* measured files readcount */
 110         unsigned int writecount;/* measured files writecount */
 111         struct kref refcount;   /* ima_iint_cache reference count */
 112 };
 113
 114 /* LIM API function definitions */
 115 int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
 116                      int mask, int function);
 117 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
 118 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
 119                            const unsigned char *filename);
 120 int ima_store_template(struct ima_template_entry *entry, int violation,
 121                        struct inode *inode);
 122 void ima_template_show(struct seq_file *m, void *e,
 123                        enum ima_show_type show);
 124
 125 /* rbtree tree calls to lookup, insert, delete
 126  * integrity data associated with an inode.
 127  */
 128 struct ima_iint_cache *ima_iint_insert(struct inode *inode);
 129 struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
 130 void iint_free(struct kref *kref);
 131
 132 /* IMA policy related functions */
 133 enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };
 134
 135 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
 136 void ima_init_policy(void);
 137 void ima_update_policy(void);
 138 ssize_t ima_parse_add_rule(char *);
 139 void ima_delete_rules(void);
 140
 141 /* LSM based policy rules require audit */
 142 #ifdef CONFIG_IMA_LSM_RULES
 143
 144 #define security_filter_rule_init security_audit_rule_init
 145 #define security_filter_rule_match security_audit_rule_match
 146
 147 #else
 148
 149 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 150                                             void **lsmrule)
 151 {
 152         return -EINVAL;
 153 }
 154
 155 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 156                                              void *lsmrule,
 157                                              struct audit_context *actx)
 158 {
 159         return -EINVAL;
 160 }
 161 #endif /* CONFIG_IMA_LSM_RULES */
 162 #endif