/*
   * 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/security.h>
  #include <linux/hash.h>
  #include <linux/tpm.h>
  #include <linux/audit.h>
  
  #include "../integrity.h"
  
  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"
  
  /* set during initialization */
  extern int ima_initialized;
  extern int ima_used_chip;
  extern int ima_hash_algo;
  extern int ima_appraise;
  
  /* 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 integrity_iint_cache *iint, struct file *file,
  			   const unsigned char *filename,
  			   struct evm_ima_xattr_data *xattr_value,
  			   int xattr_len, 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 {
  	char *name;
  	char *fmt;
  	int num_fields;
  	struct ima_template_field **fields;
  };
  
  struct ima_template_entry {
  	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 */
  
  /* Internal IMA function definitions */
  int ima_init(void);
  void ima_cleanup(void);
  int ima_fs_init(void);
  void ima_fs_cleanup(void);
  int ima_inode_alloc(struct inode *inode);
  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_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,
  		       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, int size);
  struct ima_template_desc *ima_template_desc_current(void);
  int ima_init_template(void);
  
  int ima_init_template(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);
  }
  
  /* LIM API function definitions */
  int ima_get_action(struct inode *inode, int mask, int function);
  int ima_must_measure(struct inode *inode, int mask, int function);
  int ima_collect_measurement(struct integrity_iint_cache *iint,
  			    struct file *file,
  			    struct evm_ima_xattr_data **xattr_value,
  			    int *xattr_len);
  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);
  void ima_audit_measurement(struct integrity_iint_cache *iint,
  			   const unsigned char *filename);
  int ima_alloc_init_template(struct integrity_iint_cache *iint,
  			    struct file *file, const unsigned char *filename,
  			    struct evm_ima_xattr_data *xattr_value,
  			    int xattr_len, struct ima_template_entry **entry);
  int ima_store_template(struct ima_template_entry *entry, int violation,
  		       struct inode *inode, const unsigned char *filename);
  void ima_free_template_entry(struct ima_template_entry *entry);
  const char *ima_d_path(struct path *path, char **pathbuf);
  
  /* rbtree tree calls to lookup, insert, delete
   * integrity data associated with an inode.
   */
  struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
  struct integrity_iint_cache *integrity_iint_find(struct inode *inode);
  
  /* IMA policy related functions */
  enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, POST_SETATTR };
  
  int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
  		     int flags);
  void ima_init_policy(void);
  void ima_update_policy(void);
  ssize_t ima_parse_add_rule(char *);
  void ima_delete_rules(void);
  
  /* Appraise integrity measurements */
  #define IMA_APPRAISE_ENFORCE	0x01
  #define IMA_APPRAISE_FIX	0x02
  #define IMA_APPRAISE_MODULES	0x04
  
  #ifdef CONFIG_IMA_APPRAISE
  int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
  			     struct file *file, const unsigned char *filename,
  			     struct evm_ima_xattr_data *xattr_value,
  			     int xattr_len);
  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,
  					   int func);
  void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
  		       struct ima_digest_data *hash);
  int ima_read_xattr(struct dentry *dentry,
  		   struct evm_ima_xattr_data **xattr_value);
  
  #else
  static inline int ima_appraise_measurement(int func,
  					   struct integrity_iint_cache *iint,
  					   struct file *file,
  					   const unsigned char *filename,
  					   struct evm_ima_xattr_data *xattr_value,
  					   int xattr_len)
  {
  	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, int func)
  {
  	return INTEGRITY_UNKNOWN;
  }
  
  static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
  				     int xattr_len,
  				     struct ima_digest_data *hash)
  {
  }
  
  static inline int ima_read_xattr(struct dentry *dentry,
  				 struct evm_ima_xattr_data **xattr_value)
  {
  	return 0;
  }
  
  #endif
  
  /* 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 */
  #endif