SNMP Manager Programmer's Guide

Encoding and Decoding Packets
SNMP Manager Programmer’s Guide–134249
6-15
Functions for Encoding Packets
Functions for Encoding Packets
After you have initialized an encoded-packet buffer, you use one of these functions to
encode into it the contents of a request or trap packet:
•
SNMP_Encode_Packet() BER-encodes the packet. BER encoding can be
interpreted by any SNMP agent or manager.
•
tdm_SNMP_Encode_Packet() can either BER- or IPC-encode a packet. IPC
encoding can be interpreted by a NonStop agent process.
SNMP_Encode_Packet()
This function BER-encodes a request or trap packet into an initialized encoded-packet
buffer. If you previously allocated memory for the buffer, SNMP_Encode_Packet()
determines whether the memory allocated is sufficient, then proceeds only if it is. If you
have not allocated memory for the buffer, this function dynamically allocates enough
memory to hold the encoded packet.
rcode
is an integer describing the outcome of the call. If the call is successful, 0 is
returned; if not, -1 is returned.
packet
is a pointer to an unencoded request or trap packet.
buffer
is a pointer to the descriptor structure for an encoded-packet buffer previously
initialized with EBufferInitialize() or EBufferSetup().
The sample managers that transmit and receive packets using only the UDP protocol call
SNMP_Encode_Packet() after a request or trap packet has been constructed and before
transmitting it to the target entity. Here is what the call looks like in SNMPGT:
SNMP_PKT_T *send_pkt;
EBUFFER_T ebuff.
rcode = SNMP_Encode_Packet(send_pkt, &ebuff);
tdm_SNMP_Encode_Packet()
This function either BER- or IPC-encodes a request or trap packet into an initialized
encoded-packet buffer, depending on the value of its final argument. If you previously
allocated memory for the buffer, tdm_SNMP_Encode_Packet() determines whether the
rcode = SNMP_Encode_Packet(packet, buffer);
int SNMP_Encode_Packet(SNMP_PKT_T* packet, EBUFFER_T*
buffer);