/*
 * 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"

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 {
        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);
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_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);
}

enum ima_hooks {
        FILE_CHECK = 1,
        MMAP_CHECK,
        BPRM_CHECK,
        POST_SETATTR,
        MODULE_CHECK,
        FIRMWARE_CHECK,
        KEXEC_KERNEL_CHECK,
        KEXEC_INITRAMFS_CHECK,
        POLICY_CHECK,
        MAX_CHECK
};

/* LIM API function definitions */
int ima_get_action(struct inode *inode, int mask, enum ima_hooks func);
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);
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);
void ima_free_template_entry(struct ima_template_entry *entry);
const char *ima_d_path(struct path *path, char **pathbuf);

/* IMA policy related functions */
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);
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

/* 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_TRUSTED_KEYRING */

#ifdef  CONFIG_IMA_READ_POLICY
#define POLICY_FILE_FLAGS       (S_IWUSR | S_IRUSR)
#else
#define POLICY_FILE_FLAGS       S_IWUSR
#endif /* CONFIG_IMA_WRITE_POLICY */

#endif /* __LINUX_IMA_H */