// There's a bit too much going on in this function, need to break it
// apart for testability and style.
static MetisPITVerdict
_metisStandardPIT_ReceiveInterest(MetisPIT *generic, MetisMessage *interestMessage)
{
assertNotNull(generic, "Parameter pit must be non-null");
assertNotNull(interestMessage, "Parameter interestMessage must be non-null");
MetisStandardPIT *pit = metisPIT_Closure(generic);
MetisPitEntry *pitEntry = metisMatchingRulesTable_Get(pit->table, interestMessage);
if (pitEntry) {
// has it expired?
MetisTicks now = metisForwarder_GetTicks(pit->metis);
if (now < metisPitEntry_GetExpiryTime(pitEntry)) {
// what should we do about extending the lifetime? (case 819)
_metisPIT_ExtendLifetime(pit, pitEntry, interestMessage);
// Is the reverse path already in the PIT entry?
if (_metisPIT_IngressSetContains(pitEntry, metisMessage_GetIngressConnectionId(interestMessage))) {
// It is already in the PIT entry, so this is a retransmission, so forward it.
if (metisLogger_IsLoggable(pit->logger, MetisLoggerFacility_Processor, PARCLogLevel_Debug)) {
metisLogger_Log(pit->logger, MetisLoggerFacility_Processor, PARCLogLevel_Debug, __func__,
"Message %p existing entry (expiry %" PRIu64 ") and reverse path, forwarding",
(void *) interestMessage,
metisPitEntry_GetExpiryTime(pitEntry));
}
return MetisPITVerdict_Forward;
}
// It is in the PIT but this is the first interest for the reverse path
metisPitEntry_AddIngressId(pitEntry, metisMessage_GetIngressConnectionId(interestMessage));
if (metisLogger_IsLoggable(pit->logger, MetisLoggerFacility_Processor, PARCLogLevel_Debug)) {
metisLogger_Log(pit->logger, MetisLoggerFacility_Processor, PARCLogLevel_Debug, __func__,
"Message %p existing entry (expiry %" PRIu64 ") and reverse path is new, aggregate",
(void *) interestMessage,
metisPitEntry_GetExpiryTime(pitEntry));
}
return MetisPITVerdict_Aggregate;
}
// it's an old entry, remove it
metisMatchingRulesTable_RemoveFromBest(pit->table, interestMessage);
}
_metisPIT_StoreInTable(pit, interestMessage);
return MetisPITVerdict_Forward;
}
static MetisTicks
_metisPIT_CalculateLifetime(MetisStandardPIT *pit, MetisMessage *interestMessage)
{
// Should use the lifetime from the interest (case 694)
uint64_t interestLifetimeTicks = 0;
if (metisMessage_HasInterestLifetime(interestMessage)) {
interestLifetimeTicks = metisMessage_GetInterestLifetimeTicks(interestMessage);
} else {
interestLifetimeTicks = metisForwarder_NanosToTicks(4000000000ULL);
}
MetisTicks expiryTime = metisForwarder_GetTicks(pit->metis) + interestLifetimeTicks;
return expiryTime;
}
/**
* @function single_read
* @abstract Read at most 1 message from the network
* @discussion
* If a complete message is ready on the input buffer, will allocate and return it.
*
* This function manipulates the stream->nextMessageLength. (1) Initializes with nextMessageLength = 0,
* which means we have not started parsing a packet. (2) After reading a FixedHeader, set nextMessageLength
* to the total length of the message. (3) After reading nextMessageLength bytes, return the outputBuffer
* and reset nextMessageLength to 0.
*
* @param input is the PARCEventBuffer to read
* @param stream is the related stream state for the input
* @return true if there's more to read after this message.
*/
static MetisMessage *
_single_read(PARCEventBuffer *input, _MetisStreamState *stream)
{
size_t bytesAvailable = parcEventBuffer_GetLength(input);
assertTrue(bytesAvailable >= metisTlv_FixedHeaderLength(), "Called with too short an input: %zu", bytesAvailable);
if (metisLogger_IsLoggable(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug)) {
metisLogger_Log(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug, __func__,
"connid %u read %zu bytes",
stream->id, bytesAvailable);
}
if (stream->nextMessageLength == 0) {
_startNewMessage(stream, input, bytesAvailable);
}
// This is not an ELSE statement. We can both start a new message then
// check if there's enough bytes to read the whole thing.
if (bytesAvailable >= stream->nextMessageLength) {
MetisMessage *message = _readMessage(stream, metisForwarder_GetTicks(stream->metis), input);
if (metisLogger_IsLoggable(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug)) {
metisLogger_Log(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug, __func__,
"connid %u msg_length %zu read_length %zu, resetting parser",
stream->id,
stream->nextMessageLength,
bytesAvailable);
}
// now reset message length for next packet
stream->nextMessageLength = 0;
return message;
}
return NULL;
}
static void
metisConfiguration_SendResponse(MetisConfiguration *config, CCNxControl *response, unsigned egressId)
{
PARCBuffer *responseBuffer = metisTlv_EncodeControlPlaneInformation(response);
MetisMessage *tlvEncodedResponse = metisMessage_CreateFromParcBuffer(responseBuffer, 0, metisForwarder_GetTicks(config->metis), metisForwarder_GetLogger(config->metis));
parcBuffer_Release(&responseBuffer);
MetisConnectionTable *connectionTable = metisForwarder_GetConnectionTable(config->metis);
const MetisConnection *conn = metisConnectionTable_FindById(connectionTable, egressId);
assertNotNull(conn, "Got null connection for control message we just received");
metisConnection_Send(conn, tlvEncodedResponse);
metisMessage_Release(&tlvEncodedResponse);
}
