snmp_core.h File Reference

#include "lwip/apps/snmp_opts.h"
#include "lwip/ip_addr.h"
#include "lwip/err.h"

Data Structures
struct	snmp_obj_id
union	snmp_variant_value
struct	snmp_node
struct	snmp_node_instance
struct	snmp_tree_node
struct	snmp_leaf_node
struct	snmp_mib
struct	snmp_oid_range
struct	snmp_next_oid_state

Macros
#define	SNMP_NODE_TREE   0x00

Enumerations
enum	snmp_err_t
enum	snmp_access_t

Functions
u8_t	snmp_oid_in_range (const u32_t *oid_in, u8_t oid_len, const struct snmp_oid_range *oid_ranges, u8_t oid_ranges_len)
void	snmp_next_oid_init (struct snmp_next_oid_state *state, const u32_t *start_oid, u8_t start_oid_len, u32_t *next_oid_buf, u8_t next_oid_max_len)
u8_t	snmp_next_oid_precheck (struct snmp_next_oid_state *state, const u32_t *oid, u8_t oid_len)
u8_t	snmp_next_oid_check (struct snmp_next_oid_state *state, const u32_t *oid, u8_t oid_len, void *reference)
void	snmp_oid_assign (struct snmp_obj_id *target, const u32_t *oid, u8_t oid_len)
void	snmp_oid_combine (struct snmp_obj_id *target, const u32_t *oid1, u8_t oid1_len, const u32_t *oid2, u8_t oid2_len)
void	snmp_oid_prefix (struct snmp_obj_id *target, const u32_t *oid, u8_t oid_len)
void	snmp_oid_append (struct snmp_obj_id *target, const u32_t *oid, u8_t oid_len)
u8_t	snmp_oid_equal (const u32_t *oid1, u8_t oid1_len, const u32_t *oid2, u8_t oid2_len)
s8_t	snmp_oid_compare (const u32_t *oid1, u8_t oid1_len, const u32_t *oid2, u8_t oid2_len)
u8_t	snmp_oid_to_ip4 (const u32_t *oid, ip4_addr_t *ip)
void	snmp_ip4_to_oid (const ip4_addr_t *ip, u32_t *oid)
u8_t	snmp_oid_to_ip6 (const u32_t *oid, ip6_addr_t *ip)
void	snmp_ip6_to_oid (const ip6_addr_t *ip, u32_t *oid)
u8_t	snmp_ip_to_oid (const ip_addr_t *ip, u32_t *oid)
u8_t	snmp_ip_port_to_oid (const ip_addr_t *ip, u16_t port, u32_t *oid)
u8_t	snmp_oid_to_ip (const u32_t *oid, u8_t oid_len, ip_addr_t *ip)
u8_t	snmp_oid_to_ip_port (const u32_t *oid, u8_t oid_len, ip_addr_t *ip, u16_t *port)
u8_t	netif_to_num (const struct netif *netif)
err_t	snmp_decode_bits (const u8_t *buf, u32_t buf_len, u32_t *bit_value)
u8_t	snmp_encode_bits (u8_t *buf, u32_t buf_len, u32_t bit_value, u8_t bit_count)

Detailed Description

SNMP core API for implementing MIBs

Macro Definition Documentation

SNMP_NODE_TREE

#define SNMP_NODE_TREE   0x00

SNMP MIB node types tree node is the only node the stack can process in order to walk the tree, all other nodes are assumed to be leaf nodes. This cannot be an enum because users may want to define their own node types.

Enumeration Type Documentation

snmp_access_t

enum snmp_access_t

SNMP node instance access types

snmp_err_t

enum snmp_err_t

error codes predefined by SNMP prot.

Function Documentation

netif_to_num()

u8_t netif_to_num

(

const struct netif *

netif

)

Convert netif to interface index

Parameters

netif

netif

Returns

index

snmp_decode_bits()

err_t snmp_decode_bits	(	const u8_t *	buf,
		u32_t	buf_len,
		u32_t *	bit_value
	)

Decodes BITS pseudotype value from ASN.1 OctetString.

Note

Because BITS pseudo type is encoded as OCTET STRING, it cannot directly be encoded/decoded by the agent. Instead call this function as required from get/test/set methods.

Parameters

buf	points to a buffer holding the ASN1 octet string
buf_len	length of octet string
bit_value	decoded Bit value with Bit0 == LSB

Returns

ERR_OK if successful, ERR_ARG if bit value contains more than 32 bit

snmp_encode_bits()

u8_t snmp_encode_bits	(	u8_t *	buf,
		u32_t	buf_len,
		u32_t	bit_value,
		u8_t	bit_count
	)

Encodes BITS pseudotype value into ASN.1 OctetString.

Note

Because BITS pseudo type is encoded as OCTET STRING, it cannot directly be encoded/decoded by the agent. Instead call this function as required from get/test/set methods.

Parameters

buf	points to a buffer where the resulting ASN1 octet string is stored to
buf_len	max length of the bufffer
bit_value	Bit value to encode with Bit0 == LSB
bit_count	Number of possible bits for the bit value (according to rfc we have to send all bits independant from their truth value)

Returns

number of bytes used from buffer to store the resulting OctetString

snmp_ip4_to_oid()

void snmp_ip4_to_oid	(	const ip4_addr_t *	ip,
		u32_t *	oid
	)

Convert ip4_addr to InetAddressIPv4 (no InetAddressType)

Parameters

ip	points to input struct
oid	points to u32_t ident[4] output

snmp_ip6_to_oid()

void snmp_ip6_to_oid	(	const ip6_addr_t *	ip,
		u32_t *	oid
	)

Convert ip6_addr to InetAddressIPv6 (no InetAddressType)

Parameters

ip	points to input struct
oid	points to u32_t ident[16] output

snmp_ip_port_to_oid()

u8_t snmp_ip_port_to_oid	(	const ip_addr_t *	ip,
		u16_t	port,
		u32_t *	oid
	)

Convert to InetAddressType+InetAddress+InetPortNumber

Parameters

ip	IP address
port	Port
oid	OID

Returns

OID length

snmp_ip_to_oid()

u8_t snmp_ip_to_oid	(	const ip_addr_t *	ip,
		u32_t *	oid
	)

Convert to InetAddressType+InetAddress

Parameters

ip	IP address
oid	OID

Returns

OID length

snmp_next_oid_check()

u8_t snmp_next_oid_check	(	struct snmp_next_oid_state *	state,
		const u32_t *	oid,
		u8_t	oid_len,
		void *	reference
	)

checks the passed OID if it is a candidate to be the next one (get_next); returns !=0 if passed oid is currently closest, otherwise 0

snmp_next_oid_init()

void snmp_next_oid_init	(	struct snmp_next_oid_state *	state,
		const u32_t *	start_oid,
		u8_t	start_oid_len,
		u32_t *	next_oid_buf,
		u8_t	next_oid_max_len
	)

initialize struct next_oid_state using this function before passing it to next_oid_check

snmp_next_oid_precheck()

u8_t snmp_next_oid_precheck	(	struct snmp_next_oid_state *	state,
		const u32_t *	oid,
		u8_t	oid_len
	)

checks if the passed incomplete OID may be a possible candidate for snmp_next_oid_check(); this methid is intended if the complete OID is not yet known but it is very expensive to build it up, so it is possible to test the starting part before building up the complete oid and pass it to snmp_next_oid_check()

snmp_oid_append()

void snmp_oid_append	(	struct snmp_obj_id *	target,
		const u32_t *	oid,
		u8_t	oid_len
	)

Append OIDs to struct snmp_obj_id

Parameters

target	Assignment target to append to
oid	OID
oid_len	OID length

snmp_oid_assign()

void snmp_oid_assign	(	struct snmp_obj_id *	target,
		const u32_t *	oid,
		u8_t	oid_len
	)

Assign an OID to struct snmp_obj_id

Parameters

target	Assignment target
oid	OID
oid_len	OID length

snmp_oid_combine()

void snmp_oid_combine	(	struct snmp_obj_id *	target,
		const u32_t *	oid1,
		u8_t	oid1_len,
		const u32_t *	oid2,
		u8_t	oid2_len
	)

Combine two OIDs into struct snmp_obj_id

Parameters

target	Assignmet target
oid1	OID 1
oid1_len	OID 1 length
oid2	OID 2
oid2_len	OID 2 length

snmp_oid_compare()

s8_t snmp_oid_compare	(	const u32_t *	oid1,
		u8_t	oid1_len,
		const u32_t *	oid2,
		u8_t	oid2_len
	)

Compare two OIDs

Parameters

oid1	OID 1
oid1_len	OID 1 length
oid2	OID 2
oid2_len	OID 2 length

Returns

-1: OID1<OID2 1: OID1 >OID2 0: equal

snmp_oid_equal()

u8_t snmp_oid_equal	(	const u32_t *	oid1,
		u8_t	oid1_len,
		const u32_t *	oid2,
		u8_t	oid2_len
	)

Check of two OIDs are equal

Parameters

oid1	OID 1
oid1_len	OID 1 length
oid2	OID 2
oid2_len	OID 2 length

Returns

1: equal 0: non-equal

snmp_oid_in_range()

u8_t snmp_oid_in_range	(	const u32_t *	oid_in,
		u8_t	oid_len,
		const struct snmp_oid_range *	oid_ranges,
		u8_t	oid_ranges_len
	)

checks if incoming OID length and values are in allowed ranges

snmp_oid_prefix()

void snmp_oid_prefix	(	struct snmp_obj_id *	target,
		const u32_t *	oid,
		u8_t	oid_len
	)

Prefix an OID to OID in struct snmp_obj_id

Parameters

target	Assignment target to prefix
oid	OID
oid_len	OID length

snmp_oid_to_ip()

u8_t snmp_oid_to_ip	(	const u32_t *	oid,
		u8_t	oid_len,
		ip_addr_t *	ip
	)

Convert from InetAddressType+InetAddress to ip_addr_t

Parameters

oid	OID
oid_len	OID length
ip	IP address

Returns

Parsed OID length

snmp_oid_to_ip4()

u8_t snmp_oid_to_ip4	(	const u32_t *	oid,
		ip4_addr_t *	ip
	)

Conversion from InetAddressIPv4 oid to lwIP ip4_addr

Parameters

oid	points to u32_t ident[4] input
ip	points to output struct

snmp_oid_to_ip6()

u8_t snmp_oid_to_ip6	(	const u32_t *	oid,
		ip6_addr_t *	ip
	)

Conversion from InetAddressIPv6 oid to lwIP ip6_addr

Parameters

oid	points to u32_t oid[16] input
ip	points to output struct

snmp_oid_to_ip_port()

u8_t snmp_oid_to_ip_port	(	const u32_t *	oid,
		u8_t	oid_len,
		ip_addr_t *	ip,
		u16_t *	port
	)

Convert from InetAddressType+InetAddress+InetPortNumber to ip_addr_t and u16_t

Parameters

oid	OID
oid_len	OID length
ip	IP address
port	Port

Returns

Parsed OID length