msg_out.c File Reference

Functions
void	snmp_trap_dst_enable (u8_t dst_idx, u8_t enable)
void	snmp_trap_dst_ip_set (u8_t dst_idx, struct ip_addr *dst)
err_t	snmp_send_response (struct snmp_msg_pstat *m_stat)
err_t	snmp_send_trap (s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap)
Variables
struct snmp_msg_trap	trap_msg

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Detailed Description

SNMP output message processing (RFC1157).

Output responses and traps are build in two passes:

Pass 0: iterate over the output message backwards to determine encoding lengths Pass 1: the actual forward encoding of internal form into ASN1

The single-pass encoding method described by Comer & Stevens requires extra buffer space and copying for reversal of the packet. The buffer requirement can be prohibitively large for big payloads (>= 484) therefore we use the two encoding passes.

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Function Documentation

err_t snmp_send_response

(

struct snmp_msg_pstat *

m_stat

)

Sends a 'getresponse' message to the request originator.

Parameters:

m_stat

points to the current message request state source

Returns:

ERR_OK when success, ERR_MEM if we're out of memory

Note:

the caller is responsible for filling in outvb in the m_stat and provide error-status and index (except for tooBig errors) ...

Todo:

do we need separate rx and tx pcbs for threaded case?

connect to the originating source

Todo:

release some memory, retry and return tooBig? tooMuchHassle?

disassociate remote address and port with this pcb

err_t snmp_send_trap	(	s8_t	generic_trap,
		struct snmp_obj_id *	eoid,
		s32_t	specific_trap
	)

Sends an generic or enterprise specific trap message.

Parameters:

	generic_trap	is the trap code
	eoid	points to enterprise object identifier
	specific_trap	used for enterprise traps when generic_trap == 6

Returns:

ERR_OK when success, ERR_MEM if we're out of memory

Note:

the caller is responsible for filling in outvb in the trap_msg

the use of the enterpise identifier field is per RFC1215. Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps and .iso.org.dod.internet.private.enterprises.yourenterprise (sysObjectID) for specific traps.

connect to the TRAP destination

disassociate remote address and port with this pcb

void snmp_trap_dst_enable	(	u8_t	dst_idx,
		u8_t	enable
	)

Sets enable switch for this trap destination.

Parameters:

	dst_idx	index in 0 .. SNMP_TRAP_DESTINATIONS-1
	enable	switch if 0 destination is disabled >0 enabled.

void snmp_trap_dst_ip_set	(	u8_t	dst_idx,
		struct ip_addr *	dst
	)

Sets IPv4 address for this trap destination.

Parameters:

	dst_idx	index in 0 .. SNMP_TRAP_DESTINATIONS-1
	dst	IPv4 address in host order.

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Variable Documentation

struct snmp_msg_trap trap_msg

TRAP message structure

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