SNMP Manager Programmer's Guide

Reference Summary
SNMP Manager Programmer’s Guide–134249
9-21
Unencoded-Packet Structure (SNMP_PKT_T)
pdu_type
The kind of PDU in the packet. The following Manager Services
defines describe values for pdu_type:
#define GET_REQUEST_PDU 0
#define GET_NEXT_REQUEST_PDU 1
#define GET_RESPONSE_PDU 2
#define SET_REQUEST_PDU 3
#define TRAP_PDU 4
#define NO_PDU 0xFF
pdu_length
The number of bytes in the PDU.
pdu
A tagged union with two principal variations, std_pdu and
trap_pdu, the former for request and response PDUs and the
latter for trap PDUs.
std_pdu
request_id
error_status
error_index
std_vbl
A structure for holding a request or response PDU. This
structure contains four fields.
The request identifier.
An indication in a response packet of whether an error occurred.
The following Manager Services defines describe values for
error_status:
#define NO_ERROR 0
#define TOO_BIG 1
#define NO_SUCH_NAME 2
#define BAD_VALUE 3
#define READ_ONLY 4
#define GEN_ERR 5
#define NO_ACCESS 6
#define WRONG_TYPE 7
#define WRONG_LENGTH 8
#define WRONG_ENCODING 9
#define WRONG_VALUE 10
#define NO_CREATION 11
#define INCONSISTENT_VALUE 12
#define RESOURCE_UNAVAILABLE 13
#define COMMIT_FAILED 14
#define UNDO_FAILED 15
#define AUTHORIZATION_ERROR 16
#define NOT_WRITABLE 17
#define INCONSISTENT_NAME 18
#define LAST_ERROR 19
An indication of which variable (an instance of a managed
object) in a list caused the error.
A structure of type VBL_T that describes the variable bindings
associated with the packet. The structure contains several fields
of interest to Manager Services programmers.
typedef struct VBL_S
{
ALENGTH_T vbl_length;
int vbl_count;
VB_T *vblist;
...
} VBL_T;