/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Reiner Sailer <sailer@watson.ibm.com>
 * Mimi Zohar <zohar@us.ibm.com>
 *
 * 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, TPM_PCR10 = 10 };

/* 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 10
#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"

#define NR_BANKS(chip) ((chip != NULL) ? chip->nr_allocated_banks : 0)

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

/* bitset of digests algorithms allowed in the setxattr hook */
extern atomic_t ima_setxattr_allowed_hash_algorithms;

/* set during initialization */
extern int ima_hash_algo __ro_after_init;
extern int ima_sha1_idx __ro_after_init;
extern int ima_hash_algo_idx __ro_after_init;
extern int ima_extra_slots __ro_after_init;
extern int ima_appraise;
extern struct tpm_chip *ima_tpm_chip;
extern const char boot_aggregate_name[];

/* 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 struct modsig *modsig;
        const char *violation;
        const void *buf;
        int buf_len;
};

/* 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;
        const struct ima_template_field **fields;
};

struct ima_template_entry {
        int pcr;
        struct tpm_digest *digests;
        struct ima_template_desc *template_desc; /* template descriptor */
        u32 template_data_len;
        struct ima_field_data template_data[];  /* 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;
};

extern const int read_idmap[];

#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_entry *entry);
int 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);
int template_desc_init_fields(const char *template_fmt,
                              const struct ima_template_field ***fields,
                              int *num_fields);
struct ima_template_desc *ima_template_desc_current(void);
struct ima_template_desc *ima_template_desc_buf(void);
struct ima_template_desc *lookup_template_desc(const char *name);
bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
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);
int __init ima_init_digests(void);
int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
                          void *lsm_data);

/*
 * 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 int ima_hash_key(u8 *digest)
{
        /* there is no point in taking a hash of part of a digest */
        return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE;
}

#define __ima_hooks(hook)                               \
        hook(NONE, none)                                \
        hook(FILE_CHECK, file)                          \
        hook(MMAP_CHECK, mmap)                          \
        hook(BPRM_CHECK, bprm)                          \
        hook(CREDS_CHECK, creds)                        \
        hook(POST_SETATTR, post_setattr)                \
        hook(MODULE_CHECK, module)                      \
        hook(FIRMWARE_CHECK, firmware)                  \
        hook(KEXEC_KERNEL_CHECK, kexec_kernel)          \
        hook(KEXEC_INITRAMFS_CHECK, kexec_initramfs)    \
        hook(POLICY_CHECK, policy)                      \
        hook(KEXEC_CMDLINE, kexec_cmdline)              \
        hook(KEY_CHECK, key)                            \
        hook(CRITICAL_DATA, critical_data)              \
        hook(SETXATTR_CHECK, setxattr_check)            \
        hook(MAX_CHECK, none)

#define __ima_hook_enumify(ENUM, str)   ENUM,
#define __ima_stringify(arg) (#arg)
#define __ima_hook_measuring_stringify(ENUM, str) \
                (__ima_stringify(measuring_ ##str)),

enum ima_hooks {
        __ima_hooks(__ima_hook_enumify)
};

static const char * const ima_hooks_measure_str[] = {
        __ima_hooks(__ima_hook_measuring_stringify)
};

static inline const char *func_measure_str(enum ima_hooks func)
{
        if (func >= MAX_CHECK)
                return ima_hooks_measure_str[NONE];

        return ima_hooks_measure_str[func];
}

extern const char *const func_tokens[];

struct modsig;

#ifdef CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS
/*
 * To track keys that need to be measured.
 */
struct ima_key_entry {
        struct list_head list;
        void *payload;
        size_t payload_len;
        char *keyring_name;
};
void ima_init_key_queue(void);
bool ima_should_queue_key(void);
bool ima_queue_key(struct key *keyring, const void *payload,
                   size_t payload_len);
void ima_process_queued_keys(void);
#else
static inline void ima_init_key_queue(void) {}
static inline bool ima_should_queue_key(void) { return false; }
static inline bool ima_queue_key(struct key *keyring,
                                 const void *payload,
                                 size_t payload_len) { return false; }
static inline void ima_process_queued_keys(void) {}
#endif /* CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS */

/* LIM API function definitions */
int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
                   const struct cred *cred, u32 secid, int mask,
                   enum ima_hooks func, int *pcr,
                   struct ima_template_desc **template_desc,
                   const char *func_data, unsigned int *allowed_algos);
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, struct modsig *modsig);
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, const struct modsig *modsig, int pcr,
                           struct ima_template_desc *template_desc);
int process_buffer_measurement(struct user_namespace *mnt_userns,
                               struct inode *inode, const void *buf, int size,
                               const char *eventname, enum ima_hooks func,
                               int pcr, const char *func_data,
                               bool buf_hash, u8 *digest, size_t digest_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,
                            struct ima_template_desc *template_desc);
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 user_namespace *mnt_userns, struct inode *inode,
                     const struct cred *cred, u32 secid, enum ima_hooks func,
                     int mask, int flags, int *pcr,
                     struct ima_template_desc **template_desc,
                     const char *func_data, unsigned int *allowed_algos);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flags(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
#define IMA_APPRAISE_KEXEC      0x40

#ifdef CONFIG_IMA_APPRAISE
int ima_check_blacklist(struct integrity_iint_cache *iint,
                        const struct modsig *modsig, int pcr);
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, const struct modsig *modsig);
int ima_must_appraise(struct user_namespace *mnt_userns, 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(const 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_check_blacklist(struct integrity_iint_cache *iint,
                                      const struct modsig *modsig, int pcr)
{
        return 0;
}

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,
                                           const struct modsig *modsig)
{
        return INTEGRITY_UNKNOWN;
}

static inline int ima_must_appraise(struct user_namespace *mnt_userns,
                                    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 */

#ifdef CONFIG_IMA_APPRAISE_MODSIG
int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
                    struct modsig **modsig);
void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
                          const u8 **digest, u32 *digest_size);
int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
                       u32 *data_len);
void ima_free_modsig(struct modsig *modsig);
#else
static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
                                  loff_t buf_len, struct modsig **modsig)
{
        return -EOPNOTSUPP;
}

static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
                                      loff_t size)
{
}

static inline int ima_get_modsig_digest(const struct modsig *modsig,
                                        enum hash_algo *algo, const u8 **digest,
                                        u32 *digest_size)
{
        return -EOPNOTSUPP;
}

static inline int ima_get_raw_modsig(const struct modsig *modsig,
                                     const void **data, u32 *data_len)
{
        return -EOPNOTSUPP;
}

static inline void ima_free_modsig(struct modsig *modsig)
{
}
#endif /* CONFIG_IMA_APPRAISE_MODSIG */

/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES

#define ima_filter_rule_init security_audit_rule_init
#define ima_filter_rule_free security_audit_rule_free
#define ima_filter_rule_match security_audit_rule_match

#else

static inline int ima_filter_rule_init(u32 field, u32 op, char *rulestr,
                                       void **lsmrule)
{
        return -EINVAL;
}

static inline void ima_filter_rule_free(void *lsmrule)
{
}

static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
                                        void *lsmrule)
{
        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 */