static CCNxMetaMessage *
_TemplateReceive(AthenaTransportLink *athenaTransportLink)
{
struct _TemplateLinkData *linkData = athenaTransportLink_GetPrivateData(athenaTransportLink);
CCNxMetaMessage *ccnxMetaMessage = NULL;
PARCBuffer *wireFormatBuffer = _internalRECEIVE(linkData);
// On error, just return and retry.
if (wireFormatBuffer == NULL) {
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink), "read error (%s)", strerror(errno));
return NULL;
}
// Construct, and return a ccnxMetaMessage from the wire format buffer.
ccnxMetaMessage = ccnxMetaMessage_CreateFromWireFormatBuffer(wireFormatBuffer);
if (ccnxMetaMessage == NULL) {
linkData->_stats.receive_DecodeFailed++;
parcLog_Error(athenaTransportLink_GetLogger(athenaTransportLink), "Failed to decode message from received packet.");
}
parcBuffer_Release(&wireFormatBuffer);
if (parcDeque_Size(linkData->queue) > 0) { // if there's another message, mark an event.
athenaTransportLink_SetEvent(athenaTransportLink, AthenaTransportLinkEvent_Receive);
}
return ccnxMetaMessage;
}
//
// Receive a message from the specified link.
//
static CCNxMetaMessage *
_ETHReceiveMessage(AthenaTransportLink *athenaTransportLink, struct ether_addr *peerAddress, socklen_t *peerAddressLength)
{
struct _ETHLinkData *linkData = athenaTransportLink_GetPrivateData(athenaTransportLink);
CCNxMetaMessage *ccnxMetaMessage = NULL;
AthenaTransportLinkEvent events = 0;
PARCBuffer *message = athenaEthernet_Receive(linkData->athenaEthernet, -1, &events);
if (message == NULL) {
return NULL;
}
// Mark any pending events
if (events) {
athenaTransportLink_SetEvent(athenaTransportLink, events);
}
// Map the header
struct ether_header *header = parcBuffer_Overlay(message, sizeof(struct ether_header));
// If the destination does not match my address, drop the message
if (memcmp(&linkData->link.myAddress, header->ether_dhost, ETHER_ADDR_LEN * sizeof(uint8_t)) != 0) {
linkData->_stats.receive_NoLinkDestination++;
parcBuffer_Release(&message);
return NULL;
}
assertTrue(header->ether_type == htons(CCNX_ETHERTYPE), "Unexpected ether type %x", header->ether_type);
// Set peerAddress from header source address
*peerAddressLength = ETHER_ADDR_LEN * sizeof(uint8_t);
memcpy(peerAddress, header->ether_shost, *peerAddressLength);
parcBuffer_SetPosition(message, sizeof(struct ether_header));
PARCBuffer *wireFormatBuffer = parcBuffer_Slice(message);
parcBuffer_Release(&message);
parcBuffer_SetPosition(wireFormatBuffer, 0);
// Construct, and return a ccnxMetaMessage from the wire format buffer.
ccnxMetaMessage = ccnxMetaMessage_CreateFromWireFormatBuffer(wireFormatBuffer);
if (ccnxMetaMessage == NULL) {
linkData->_stats.receive_DecodeFailed++;
parcLog_Error(athenaTransportLink_GetLogger(athenaTransportLink), "Failed to decode message from received packet.");
} else if (ccnxTlvDictionary_GetSchemaVersion(ccnxMetaMessage) == CCNxTlvDictionary_SchemaVersion_V0) {
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink),
"received deprecated version %d message\n", ccnxTlvDictionary_GetSchemaVersion(ccnxMetaMessage));
}
parcBuffer_Release(&wireFormatBuffer);
return ccnxMetaMessage;
}
LONGBOW_TEST_CASE(Global, ccnxMetaMessage_EncodeDecode)
{
CCNxName *name = ccnxName_CreateFromCString("lci:/foo/bar");
CCNxInterest *interest = ccnxInterest_CreateSimple(name);
ccnxName_Release(&name);
PARCSigner *signer = ccnxValidationCRC32C_CreateSigner(); // Would really be SHA256 or something.
// Encode it to wire format.
PARCBuffer *wireFormatBuffer = ccnxMetaMessage_CreateWireFormatBuffer(interest, signer);
// Now decode it from wireformat.
CCNxMetaMessage *decodedMessage = ccnxMetaMessage_CreateFromWireFormatBuffer(wireFormatBuffer);
// At this point, the unpacked dictionary should be equivalent to the original interest.
assertTrue(ccnxInterest_Equals(interest, decodedMessage), "Expected an equivalent interest to be unpacked");
parcBuffer_Release(&wireFormatBuffer);
ccnxInterest_Release(&interest);
ccnxMetaMessage_Release(&decodedMessage);
parcSigner_Release(&signer);
}
//
// Receive a message from the specified link.
//
static CCNxMetaMessage *
_UDPReceiveMessage(AthenaTransportLink *athenaTransportLink, struct sockaddr_in *peerAddress, socklen_t *peerAddressLength)
{
struct _UDPLinkData *linkData = athenaTransportLink_GetPrivateData(athenaTransportLink);
CCNxMetaMessage *ccnxMetaMessage = NULL;
size_t messageLength;
// If an MTU has been set, allocate a buffer of that size to avoid having to peek at the message,
// othersize derive the link from the header and allocate a buffer based on the message size.
if ((messageLength = linkData->link.mtu) == 0) {
messageLength = _messageLengthFromHeader(athenaTransportLink, linkData);
if (messageLength <= 0) {
return NULL;
}
}
PARCBuffer *wireFormatBuffer = parcBuffer_Allocate(messageLength);
char *buffer = parcBuffer_Overlay(wireFormatBuffer, 0);
*peerAddressLength = (socklen_t) sizeof(struct sockaddr_in);
ssize_t readCount = recvfrom(linkData->fd, buffer, messageLength, 0, (struct sockaddr *) peerAddress, peerAddressLength);
// On error, just return and retry.
if (readCount == -1) {
linkData->_stats.receive_ReadError++;
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink), "read error (%s)", strerror(errno));
parcBuffer_Release(&wireFormatBuffer);
return NULL;
}
// A zero read means either no more data is currently available or our peer hungup.
// Just return to retry as we'll detect EOF when we come back at the top of UDPReceive
if (readCount == 0) {
parcBuffer_Release(&wireFormatBuffer);
return NULL;
}
// If it was it a short read just return to retry later.
while (readCount < messageLength) {
linkData->_stats.receive_ShortRead++;
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink), "short read error (%s)", strerror(errno));
parcBuffer_Release(&wireFormatBuffer);
return NULL;
}
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink), "received message (size=%d)", readCount);
parcBuffer_SetPosition(wireFormatBuffer, parcBuffer_Position(wireFormatBuffer) + readCount);
parcBuffer_Flip(wireFormatBuffer);
// Construct, and return a ccnxMetaMessage from the wire format buffer.
ccnxMetaMessage = ccnxMetaMessage_CreateFromWireFormatBuffer(wireFormatBuffer);
if (ccnxTlvDictionary_GetSchemaVersion(ccnxMetaMessage) == CCNxTlvDictionary_SchemaVersion_V0) {
parcLog_Debug(athenaTransportLink_GetLogger(athenaTransportLink),
"received deprecated version %d message\n", ccnxTlvDictionary_GetSchemaVersion(ccnxMetaMessage));
}
if (ccnxMetaMessage == NULL) {
linkData->_stats.receive_DecodeFailed++;
parcLog_Error(athenaTransportLink_GetLogger(athenaTransportLink), "Failed to decode message from received packet.");
}
parcBuffer_Release(&wireFormatBuffer);
return ccnxMetaMessage;
}