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_inode_alloc(struct inode *inode);
  74 int ima_add_template_entry(struct ima_template_entry *entry, int violation,
  75                            const char *op, struct inode *inode);
  76 int ima_calc_hash(struct file *file, char *digest);
  77 int ima_calc_template_hash(int template_len, void *template, char *digest);
  78 int ima_calc_boot_aggregate(char *digest);
  79 void ima_add_violation(struct inode *inode, const unsigned char *filename,
  80                        const char *op, const char *cause);
  81
  82 /*
  83  * used to protect h_table and sha_table
  84  */
  85 extern spinlock_t ima_queue_lock;
  86
  87 struct ima_h_table {
  88         atomic_long_t len;      /* number of stored measurements in the list */
  89         atomic_long_t violations;
  90         struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
  91 };
  92 extern struct ima_h_table ima_htable;
  93
  94 static inline unsigned long ima_hash_key(u8 *digest)
  95 {
  96         return hash_long(*digest, IMA_HASH_BITS);
  97 }
  98
  99 /* iint cache flags */
 100 #define IMA_MEASURED            0x01
 101
 102 /* integrity data associated with an inode */
 103 struct ima_iint_cache {
 104         struct rb_node rb_node; /* rooted in ima_iint_tree */
 105         struct inode *inode;    /* back pointer to inode in question */
 106         u64 version;            /* track inode changes */
 107         unsigned char flags;
 108         u8 digest[IMA_DIGEST_SIZE];
 109         struct mutex mutex;     /* protects: version, flags, digest */
 110 };
 111
 112 /* LIM API function definitions */
 113 int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
 114                      int mask, int function);
 115 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
 116 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
 117                            const unsigned char *filename);
 118 int ima_store_template(struct ima_template_entry *entry, int violation,
 119                        struct inode *inode);
 120 void ima_template_show(struct seq_file *m, void *e,
 121                        enum ima_show_type show);
 122
 123 /* rbtree tree calls to lookup, insert, delete
 124  * integrity data associated with an inode.
 125  */
 126 struct ima_iint_cache *ima_iint_insert(struct inode *inode);
 127 struct ima_iint_cache *ima_iint_find(struct inode *inode);
 128
 129 /* IMA policy related functions */
 130 enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };
 131
 132 int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
 133 void ima_init_policy(void);
 134 void ima_update_policy(void);
 135 ssize_t ima_parse_add_rule(char *);
 136 void ima_delete_rules(void);
 137
 138 /* LSM based policy rules require audit */
 139 #ifdef CONFIG_IMA_LSM_RULES
 140
 141 #define security_filter_rule_init security_audit_rule_init
 142 #define security_filter_rule_match security_audit_rule_match
 143
 144 #else
 145
 146 static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
 147                                             void **lsmrule)
 148 {
 149         return -EINVAL;
 150 }
 151
 152 static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
 153                                              void *lsmrule,
 154                                              struct audit_context *actx)
 155 {
 156         return -EINVAL;
 157 }
 158 #endif /* CONFIG_IMA_LSM_RULES */
 159 #endif