/*
   * Copyright (C) 2005,2006,2007,2008 IBM Corporation
   *
   * Authors:
   * Reiner Sailer <sailer@watson.ibm.com>
   * Mimi Zohar <zohar@us.ibm.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation, version 2 of the
   * License.
   *
   * File: ima.h
   *	internal Integrity Measurement Architecture (IMA) definitions
   */
  
  #ifndef __LINUX_IMA_H
  #define __LINUX_IMA_H
  
  #include <linux/types.h>
  #include <linux/crypto.h>

  #include <linux/fs.h>

  #include <linux/security.h>
  #include <linux/hash.h>
  #include <linux/tpm.h>
  #include <linux/audit.h>

  #include <crypto/hash_info.h>

  #include "../integrity.h"

  #ifdef CONFIG_HAVE_IMA_KEXEC
  #include <asm/ima.h>
  #endif

  enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,

  		     IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };

  enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
  
  /* digest size for IMA, fits SHA1 or MD5 */

  #define IMA_DIGEST_SIZE		SHA1_DIGEST_SIZE

  #define IMA_EVENT_NAME_LEN_MAX	255
  
  #define IMA_HASH_BITS 9
  #define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)

  #define IMA_TEMPLATE_FIELD_ID_MAX_LEN	16
  #define IMA_TEMPLATE_NUM_FIELDS_MAX	15

  #define IMA_TEMPLATE_IMA_NAME "ima"
  #define IMA_TEMPLATE_IMA_FMT "d|n"

  /* current content of the policy */
  extern int ima_policy_flag;

  /* set during initialization */
  extern int ima_initialized;
  extern int ima_used_chip;

  extern int ima_hash_algo;

  extern int ima_appraise;

  /* IMA event related data */
  struct ima_event_data {
  	struct integrity_iint_cache *iint;
  	struct file *file;
  	const unsigned char *filename;
  	struct evm_ima_xattr_data *xattr_value;
  	int xattr_len;

  	const char *violation;

  };

  /* IMA template field data definition */
  struct ima_field_data {
  	u8 *data;
  	u32 len;
  };
  
  /* IMA template field definition */
  struct ima_template_field {
  	const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];

  	int (*field_init)(struct ima_event_data *event_data,
  			  struct ima_field_data *field_data);
  	void (*field_show)(struct seq_file *m, enum ima_show_type show,
  			   struct ima_field_data *field_data);

  };
  
  /* IMA template descriptor definition */
  struct ima_template_desc {

  	struct list_head list;

  	char *name;
  	char *fmt;
  	int num_fields;
  	struct ima_template_field **fields;
  };

  struct ima_template_entry {

  	int pcr;

  	u8 digest[TPM_DIGEST_SIZE];	/* sha1 or md5 measurement hash */

  	struct ima_template_desc *template_desc; /* template descriptor */
  	u32 template_data_len;
  	struct ima_field_data template_data[0];	/* template related data */

  };
  
  struct ima_queue_entry {
  	struct hlist_node hnext;	/* place in hash collision list */
  	struct list_head later;		/* place in ima_measurements list */
  	struct ima_template_entry *entry;
  };
  extern struct list_head ima_measurements;	/* list of all measurements */

  /* Some details preceding the binary serialized measurement list */
  struct ima_kexec_hdr {
  	u16 version;
  	u16 _reserved0;
  	u32 _reserved1;
  	u64 buffer_size;
  	u64 count;
  };
  
  #ifdef CONFIG_HAVE_IMA_KEXEC
  void ima_load_kexec_buffer(void);
  #else
  static inline void ima_load_kexec_buffer(void) {}
  #endif /* CONFIG_HAVE_IMA_KEXEC */

  /*
   * The default binary_runtime_measurements list format is defined as the
   * platform native format.  The canonical format is defined as little-endian.
   */
  extern bool ima_canonical_fmt;

  /* Internal IMA function definitions */

  int ima_init(void);

  int ima_fs_init(void);

  int ima_add_template_entry(struct ima_template_entry *entry, int violation,

  			   const char *op, struct inode *inode,
  			   const unsigned char *filename);

  int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);

  int ima_calc_buffer_hash(const void *buf, loff_t len,
  			 struct ima_digest_data *hash);

  int ima_calc_field_array_hash(struct ima_field_data *field_data,
  			      struct ima_template_desc *desc, int num_fields,

  			      struct ima_digest_data *hash);

  int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);

  void ima_add_violation(struct file *file, const unsigned char *filename,

  		       struct integrity_iint_cache *iint,

  		       const char *op, const char *cause);

  int ima_init_crypto(void);

  void ima_putc(struct seq_file *m, void *data, int datalen);

  void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);

  struct ima_template_desc *ima_template_desc_current(void);

  int ima_restore_measurement_entry(struct ima_template_entry *entry);
  int ima_restore_measurement_list(loff_t bufsize, void *buf);

  int ima_measurements_show(struct seq_file *m, void *v);

  unsigned long ima_get_binary_runtime_size(void);

  int ima_init_template(void);

  void ima_init_template_list(void);

  
  /*
   * used to protect h_table and sha_table
   */
  extern spinlock_t ima_queue_lock;
  
  struct ima_h_table {
  	atomic_long_t len;	/* number of stored measurements in the list */
  	atomic_long_t violations;
  	struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
  };
  extern struct ima_h_table ima_htable;
  
  static inline unsigned long ima_hash_key(u8 *digest)
  {
  	return hash_long(*digest, IMA_HASH_BITS);
  }

  #define __ima_hooks(hook)		\
  	hook(NONE)			\
  	hook(FILE_CHECK)		\
  	hook(MMAP_CHECK)		\
  	hook(BPRM_CHECK)		\
  	hook(POST_SETATTR)		\
  	hook(MODULE_CHECK)		\
  	hook(FIRMWARE_CHECK)		\
  	hook(KEXEC_KERNEL_CHECK)	\
  	hook(KEXEC_INITRAMFS_CHECK)	\
  	hook(POLICY_CHECK)		\
  	hook(MAX_CHECK)
  #define __ima_hook_enumify(ENUM)	ENUM,

  enum ima_hooks {

  	__ima_hooks(__ima_hook_enumify)

  };

  /* LIM API function definitions */

  int ima_get_action(struct inode *inode, int mask,
  		   enum ima_hooks func, int *pcr);

  int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);

  int ima_collect_measurement(struct integrity_iint_cache *iint,

  			    struct file *file, void *buf, loff_t size,
  			    enum hash_algo algo);

  void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,

  			   const unsigned char *filename,
  			   struct evm_ima_xattr_data *xattr_value,

  			   int xattr_len, int pcr);

  void ima_audit_measurement(struct integrity_iint_cache *iint,
  			   const unsigned char *filename);

  int ima_alloc_init_template(struct ima_event_data *event_data,
  			    struct ima_template_entry **entry);

  int ima_store_template(struct ima_template_entry *entry, int violation,

  		       struct inode *inode,
  		       const unsigned char *filename, int pcr);

  void ima_free_template_entry(struct ima_template_entry *entry);

  const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);

  /* IMA policy related functions */

  int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,

  		     int flags, int *pcr);

  void ima_init_policy(void);
  void ima_update_policy(void);

  void ima_update_policy_flag(void);

  ssize_t ima_parse_add_rule(char *);

  void ima_delete_rules(void);

  int ima_check_policy(void);

  void *ima_policy_start(struct seq_file *m, loff_t *pos);
  void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
  void ima_policy_stop(struct seq_file *m, void *v);
  int ima_policy_show(struct seq_file *m, void *v);

  /* Appraise integrity measurements */
  #define IMA_APPRAISE_ENFORCE	0x01
  #define IMA_APPRAISE_FIX	0x02

  #define IMA_APPRAISE_LOG	0x04
  #define IMA_APPRAISE_MODULES	0x08
  #define IMA_APPRAISE_FIRMWARE	0x10

  #define IMA_APPRAISE_POLICY	0x20

  
  #ifdef CONFIG_IMA_APPRAISE

  int ima_appraise_measurement(enum ima_hooks func,
  			     struct integrity_iint_cache *iint,

  			     struct file *file, const unsigned char *filename,
  			     struct evm_ima_xattr_data *xattr_value,

  			     int xattr_len, int opened);

  int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);

  void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);

  enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,

  					   enum ima_hooks func);

  enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
  				 int xattr_len);

  int ima_read_xattr(struct dentry *dentry,
  		   struct evm_ima_xattr_data **xattr_value);

  
  #else

  static inline int ima_appraise_measurement(enum ima_hooks func,

  					   struct integrity_iint_cache *iint,

  					   struct file *file,

  					   const unsigned char *filename,
  					   struct evm_ima_xattr_data *xattr_value,

  					   int xattr_len, int opened)

  {
  	return INTEGRITY_UNKNOWN;
  }

  static inline int ima_must_appraise(struct inode *inode, int mask,
  				    enum ima_hooks func)

  {
  	return 0;
  }
  
  static inline void ima_update_xattr(struct integrity_iint_cache *iint,
  				    struct file *file)
  {
  }

  
  static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache

  							 *iint,
  							 enum ima_hooks func)

  {
  	return INTEGRITY_UNKNOWN;
  }

  static inline enum hash_algo
  ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)

  {

  	return ima_hash_algo;

  }
  
  static inline int ima_read_xattr(struct dentry *dentry,
  				 struct evm_ima_xattr_data **xattr_value)
  {
  	return 0;
  }

  #endif /* CONFIG_IMA_APPRAISE */

  /* LSM based policy rules require audit */
  #ifdef CONFIG_IMA_LSM_RULES
  
  #define security_filter_rule_init security_audit_rule_init
  #define security_filter_rule_match security_audit_rule_match
  
  #else
  
  static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
  					    void **lsmrule)
  {
  	return -EINVAL;
  }
  
  static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
  					     void *lsmrule,
  					     struct audit_context *actx)
  {
  	return -EINVAL;
  }

  #endif /* CONFIG_IMA_LSM_RULES */

  
  #ifdef	CONFIG_IMA_READ_POLICY
  #define	POLICY_FILE_FLAGS	(S_IWUSR | S_IRUSR)
  #else
  #define	POLICY_FILE_FLAGS	S_IWUSR

  #endif /* CONFIG_IMA_READ_POLICY */

  
  #endif /* __LINUX_IMA_H */