/**
* Sends an generic or enterprise specific trap message.
*
* @param generic_trap is the trap code
* @param eoid points to enterprise object identifier
* @param specific_trap used for enterprise traps when generic_trap == 6
* @return ERR_OK when success, ERR_MEM if we're out of memory
*
* @note the use of the enterprise 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.
*/
static err_t
snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_trap, s32_t specific_trap)
{
struct snmp_msg_trap trap_msg;
struct snmp_trap_dst *td;
struct pbuf *p;
u16_t i, tot_len;
err_t err = ERR_OK;
trap_msg.snmp_version = 0;
for (i = 0, td = &trap_dst[0]; i < SNMP_TRAP_DESTINATIONS; i++, td++) {
if ((td->enable != 0) && !ip_addr_isany(&td->dip)) {
/* lookup current source address for this dst */
if (snmp_get_local_ip_for_dst(snmp_traps_handle, &td->dip, &trap_msg.sip)) {
if (device_enterprise_oid == NULL) {
trap_msg.enterprise = snmp_get_device_enterprise_oid();
} else {
trap_msg.enterprise = device_enterprise_oid;
}
trap_msg.gen_trap = generic_trap;
if (generic_trap == SNMP_GENTRAP_ENTERPRISE_SPECIFIC) {
trap_msg.spc_trap = specific_trap;
} else {
trap_msg.spc_trap = 0;
}
MIB2_COPY_SYSUPTIME_TO(&trap_msg.ts);
/* pass 0, calculate length fields */
tot_len = snmp_trap_header_sum(&trap_msg);
/* allocate pbuf(s) */
p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_RAM);
if (p != NULL) {
struct snmp_pbuf_stream pbuf_stream;
snmp_pbuf_stream_init(&pbuf_stream, p, 0, tot_len);
/* pass 1, encode packet ino the pbuf(s) */
snmp_trap_header_enc(&trap_msg, &pbuf_stream);
snmp_stats.outtraps++;
snmp_stats.outpkts++;
/** send to the TRAP destination */
snmp_sendto(snmp_traps_handle, p, &td->dip, SNMP_TRAP_PORT);
} else {
err = ERR_MEM;
}
} else {
/* routing error */
err = ERR_RTE;
}
}
}
return err;
}
void
snmp_receive(void *handle, struct pbuf *p, const ip_addr_t *source_ip, u16_t port)
{
err_t err;
struct snmp_request request;
memset(&request, 0, sizeof(request));
request.handle = handle;
request.source_ip = source_ip;
request.source_port = port;
request.inbound_pbuf = p;
snmp_stats.inpkts++;
err = snmp_parse_inbound_frame(&request);
if (err == ERR_OK) {
err = snmp_prepare_outbound_frame(&request);
if (err == ERR_OK) {
if (request.error_status == SNMP_ERR_NOERROR) {
/* only process frame if we do not already have an error to return (e.g. all readonly) */
if (request.request_type == SNMP_ASN1_CONTEXT_PDU_GET_REQ) {
err = snmp_process_get_request(&request);
} else if (request.request_type == SNMP_ASN1_CONTEXT_PDU_GET_NEXT_REQ) {
err = snmp_process_getnext_request(&request);
} else if (request.request_type == SNMP_ASN1_CONTEXT_PDU_GET_BULK_REQ) {
err = snmp_process_getbulk_request(&request);
} else if (request.request_type == SNMP_ASN1_CONTEXT_PDU_SET_REQ) {
err = snmp_process_set_request(&request);
}
}
if (err == ERR_OK) {
err = snmp_complete_outbound_frame(&request);
if (err == ERR_OK) {
err = snmp_sendto(request.handle, request.outbound_pbuf, request.source_ip, request.source_port);
if ((request.request_type == SNMP_ASN1_CONTEXT_PDU_SET_REQ)
&& (request.error_status == SNMP_ERR_NOERROR)
&& (snmp_write_callback != NULL)) {
/* raise write notification for all written objects */
snmp_execute_write_callbacks(&request);
}
}
}
}
if (request.outbound_pbuf != NULL) {
pbuf_free(request.outbound_pbuf);
}
}
}
