snmp_pdus(3)

NAME
snmp_pdus - Encode and Decode Functions for SNMP PDUs

DESCRIPTION

RFC1157, RFC1905 and/or RFC2272 should be studied carefully before using this module, snmp_pdus.

The module snmp_pdus contains functions for encoding and decoding of SNMP protocol data units (PDUs). In short, this module converts a list of bytes to Erlang record representations and vice versa. The record definitions can be found in the file snmp/include/snmp_types.hrl. If snmpv3 is used, the module that includes snmp_types.hrl must define the constant SNMP_USE_V3 before the header file is included. Example:

    -define(SNMP_USE_V3, true).
    -include_lib("snmp/include/snmp_types.hrl").

Encoding and decoding must be done explicitly when writing your own Net if process.

DATA TYPES

message() :: #message{}.

    The message is version dependent. 'vsn_hdr' is either a community string (v1 and v2) or a 'v3_hdr' record (v3). 'data' is either a PDU (v1 and v2c) or a (possibly encrypted) 'scopedPdu'.
msg_id() :: 0..2147483647.
msg_security_model() :: 0..2147483647.
pdu() :: #pdu{}.
pdu_type() :: 'get-request' | 'get-next-request' | 'get-bulk-request' | 'get-response' | 'set-request' | 'inform-request' | 'snmpv2-trap' | report.
scoped_pdu() :: #scopedPdu{}.
trappdu() :: #trappdu{}.
usm_security_parameters() :: #usmSecurityParameters{}.
v3_hdr() :: #v3_hdr{}.
version() :: 'version-1' | 'version-2' | 'version-3'.

FUNCTIONS

dec_message(Bytes) -> Message when Bytes :: [byte()], Message :: message().

    Decodes a list of bytes into an SNMP Message. Note, if there is a v3 message, the msgSecurityParameters are not decoded. They must be explicitly decoded by a call to a security model specific decoding function, e.g. dec_usm_security_parameters/1. Also note, if the scopedPDU is encrypted, the OCTET STRING encoded encryptedPDU will be present in the data field.
dec_message_only(Bytes) -> Message when Bytes :: [byte()], Message :: message().

    Decodes a list of bytes into an SNMP Message, but does not decode the data part of the Message. That means, data is still a list of bytes, normally an encoded PDU (v1 and V2) or an encoded and possibly encrypted scopedPDU (v3).
dec_pdu(Bytes) -> Pdu when Bytes :: [byte()], Pdu :: trappdu() | pdu().

    Decodes a list of bytes into an SNMP Pdu.
dec_scoped_pdu(Bytes) -> ScopedPDU when Bytes :: [byte()], ScopedPDU :: scoped_pdu().

    Decodes a list of bytes into an SNMP ScopedPdu.
dec_scoped_pdu_data(Bytes) -> ScopedPduData when Bytes :: [byte()], ScopedPduData :: scoped_pdu() | EncryptedPDU, EncryptedPDU :: [byte()].

    Decodes a list of bytes into either a scoped pdu record, or - if the scoped pdu was encrypted - to a list of bytes.
dec_usm_security_parameters(Bytes) -> UsmSecParams when Bytes :: [byte()], UsmSecParams :: usm_security_parameters().

    Decodes a list of bytes into an SNMP UsmSecurityParameters.
enc_message(Message) -> Bytes when Message :: message(), Bytes :: [byte()].

    Encodes a message record to a list of bytes.
enc_message_only(Message) -> Bytes when Message :: message(), Bytes :: [byte()].

    Message is a record where the data field is assumed to be encoded (a list of bytes). If there is a v1 or v2 message, the data field is an encoded PDU, and if there is a v3 message, data is an encoded and possibly encrypted scopedPDU.
enc_pdu(Pdu) -> Bytes when Pdu :: pdu(), Bytes :: [byte()].

    Encodes an SNMP Pdu into a list of bytes.
enc_scoped_pdu(ScopedPdu) -> Bytes when ScopedPdu :: scoped_pdu(), Bytes :: [byte()].

    Encodes an SNMP ScopedPdu into a list of bytes, which can be encrypted, and after encryption, encoded with a call to enc_encrypted_scoped_pdu/1; or it can be used as the data field in a message record, which then can be encoded with enc_message_only/1.
enc_usm_security_parameters(UsmSecParams) -> Bytes when UsmSecParams :: usm_security_parameters(), Bytes :: [byte()].

    Encodes SNMP UsmSecurityParameters into a list of bytes.