#ifndef _BIRD_SNMP_UTILS_H_
#define _BIRD_SNMP_UTILS_H_

#include "subagent.h"
#include "mib_tree.h"

/*
 *
 *    AgentX Variable Biding (VarBind) utils
 *
 */

/*
 *  AgentX - Variable Binding (VarBind) type utils
 */
int agentx_type_size(enum agentx_type t);

/* type Octet String */
size_t snmp_str_size_from_len(uint len);
size_t snmp_str_size(const char *str);

/* type OID - Object Identifier */
int snmp_is_oid_empty(const struct oid *oid);
int snmp_pkt_oid_is_prefixable(const struct oid *oid);
uint snmp_oid_size(const struct oid *o);
size_t snmp_oid_size_from_len(uint n_subid);
void snmp_oid_copy(struct oid *dest, const struct oid *src);
int snmp_oid_compare(const struct oid *first, const struct oid *second);
void snmp_oid_common_ancestor(const struct oid *left, const struct oid *right, struct oid *result);
void snmp_oid_from_buf(struct oid *dest, const struct oid *src);
void snmp_oid_to_buf(struct oid *dest, const struct oid *src);

static inline int
snmp_check_search_limit(const struct oid *search, const struct oid *limit)
{
  ASSERT(search && limit);
  return snmp_is_oid_empty(limit) || snmp_oid_compare(search, limit) < 0;
}

/*
 * snmp_oid_is_prefixed - test if OID is prefixed
 * @oid: OID to use
 *
 * Works for both cpu native and packet byte order.
 */
static inline int
snmp_oid_is_prefixed(const struct oid *oid)
{
  /* LOAD_U8() is in both cases basic mem load */
  return LOAD_U8(oid->prefix) != 0;
}

/* type IPv4 */
int snmp_valid_ip4_index(const struct oid *o, uint start);
int snmp_valid_ip4_index_unsafe(const struct oid *o, uint start);

/*
 *  AgentX - Variable Binding (VarBind) manupulation
 */
uint snmp_varbind_header_size(const struct oid *vb_name);
uint snmp_varbind_size_unsafe(const struct agentx_varbind *vb);
size_t snmp_varbind_size_from_len(uint n_subid, enum agentx_type t, uint len);
int snmp_test_varbind_type(u16 type);
void *snmp_varbind_data(const struct agentx_varbind *vb);

/*
 *  AgentX - PDU headers, types, contexts
 */
void snmp_session(const struct snmp_proto *p, struct agentx_header *h);
void snmp_pdu_context(struct snmp_pdu *pdu, struct snmp_proto *p, sock *sk);

static inline int
snmp_has_context(const struct agentx_header *h)
{
  return LOAD_U8(h->flags) & AGENTX_NON_DEFAULT_CONTEXT;
}

int snmp_test_close_reason(byte value);

/*
 *  AgentX - TX buffer manipulation
 */

/* Functions filling buffer a typed value */
void snmp_varbind_int(struct snmp_pdu *c, u32 val);
void snmp_varbind_counter32(struct snmp_pdu *c, u32 val);
void snmp_varbind_gauge32(struct snmp_pdu *c, s64 time);
void snmp_varbind_ticks(struct snmp_pdu *c, u32 val);
void snmp_varbind_ip4(struct snmp_pdu *c, ip4_addr addr);
void snmp_varbind_nstr(struct snmp_pdu *c, const char *str, uint len);
void snmp_varbind_oid(struct snmp_pdu *c, const struct oid *oid_val);

/* Raw */
byte *snmp_no_such_object(byte *buf, struct agentx_varbind *vb, struct oid *oid);
byte *snmp_no_such_instance(byte *buf, struct agentx_varbind *vb, struct oid *oid);
byte *snmp_put_str(byte *buf, const char *str);
byte *snmp_put_nstr(byte *buf, const char *str, uint len);
byte *snmp_put_blank(byte *buf);
byte *snmp_put_ip4(byte *buf, ip4_addr ip4);
byte *snmp_put_fbyte(byte *buf, u8 data);


/*
 *
 *    Helpers, Misc, Debugging
 *
 */
struct snmp_registration *snmp_registration_create(struct snmp_proto *p, enum agentx_mibs mib);
int snmp_registration_match(struct snmp_registration *r, struct agentx_header *h);

void snmp_oid_dump(const struct oid *oid);
void snmp_oid_log(const struct oid *oid);

enum agentx_type snmp_search_res_to_type(enum snmp_search_res res);

#define AGENTX_TYPE_INT_SIZE ((uint) agentx_type_size(AGENTX_INTEGER))
#define AGENTX_TYPE_IP4_SIZE ((uint) agentx_type_size(AGENTX_IP_ADDRESS))
#define AGENTX_TYPE_COUNTER32_SIZE ((uint) agentx_type_size(AGENTX_COUNTER_32))

/*
 * SNMP MIB tree walking
 */
struct mib_leaf *snmp_walk_init(struct mib_tree *tree, struct mib_walk_state *state, struct snmp_pdu *context);
struct mib_leaf *snmp_walk_next(struct mib_tree *tree, struct mib_walk_state *state, struct snmp_pdu *context);
enum snmp_search_res snmp_walk_fill(struct mib_leaf *leaf, struct mib_walk_state *state, struct snmp_pdu *context);

#endif