`snmp_pdu`

Structure that describes an SNMP transaction

Synopsis:

#include <snmp/snmp_api.h>

struct snmp_pdu {
    int version;
    ipaddr address;
    oid * srcParty;
    int srcPartyLen;
    oid * dstParty;
    int dstPartyLen;
    oid * context;
    int contextLen;
    u_char * community;
    int community_len;
    int command;
    long reqid;
    long errstat;
    long errindex;

    /* Trap information */
    oid * enterprise;
    int enterprise_length;
    ipaddr agent_addr;
    int trap_type;
    int specific_type;
    u_long time;

    struct variable_list * variables;
};

The snmp_pdu structure describes a Protocol Data Unit (PDU), a transaction that's performed over an open session. It contains the headers and variables of an SNMP packet. The structure includes the following members:

version: The version of SNMP: either SNMP_VERSION_1 or SNMP_VERSION_2.
address: Destination IP address.
srcParty: Source party being used.
srcPartyLen: Number of object identifier (OID) elements in srcParty. For example, if srcParty is .1.3.6, the length is 3.
dstParty: The destination party being used.
dstPartyLen: Number of OID elements in dstParty.
context: The context being used.
contextLen: Number of OID elements in context.
community: Community for outgoing requests.
community_len: Length of community name.
command: Type of this PDU.
reqid: Request ID. The default is SNMP_DEFAULT_REQID (0).
errstat: Error status (non_repeaters in GetBulk). The default is SNMP_DEFAULT_ERRSTAT (-1).
errindex: Error index (max_repetitions in GetBulk). The default is SNMP_DEFAULT_ERRINDEX (-1).
enterprise: System OID.
enterprise_length: Number of OID elements in enterprise. The default is SNMP_DEFAULT_ENTERPRISE_LENGTH (0).
agent_addr: Address of the object generating the trap.
trap_type: Trap type
specific_type: Specific type.
time: Uptime. The default is SNMP_DEFAULT_TIME (0).
variables: Linked list of variables, of type variable_list.

The variable_list structure is defined as:

typedef    struct    sockaddr_in ipaddr;

struct variable_list {
    struct variable_list* next_variable;
    oid*       name;
    int        name_length;
    u_char     type;
    union { 
        long*     integer;
        u_char*   string;
        oid*      objid;
        u_char*   bitstring;
        struct counter64* counter64;
    } val;
    int        val_len;
};

The members are:

next_variable: A pointer to the next variable. This is NULL for the last variable in the list.
name: Object identifier of the variable.
name_length: Number of sub IDs in name.
type: ASN type of variable.
val.integer: Value of the variable if it's an integer.
val.string: Value of the variable if it's a string.
val.objid: Value of the variable if it's an object ID.
bitstring: Value of the variable if it's a bitstring.
counter64: Value of the variable if it's a counter64.
val_len: Length of the value.

Classification:

SNMP

`snmp_pdu`

Synopsis:

Description:

Classification:

See also: