LONGBOW_TEST_CASE(Global, metisMessage_ReadFromBuffer)
{
char message_str[] = "\x00Once upon a time, in a stack far away, a dangling pointer found its way to the top of the heap.";
PARCEventBuffer *buff = parcEventBuffer_Create();
parcEventBuffer_Append(buff, message_str, sizeof(message_str));
PARCLogReporter *reporter = parcLogReporterTextStdout_Create();
MetisLogger *logger = metisLogger_Create(reporter, parcClock_Wallclock());
parcLogReporter_Release(&reporter);
MetisMessage *message = metisMessage_ReadFromBuffer(1, 2, buff, sizeof(message_str), logger);
metisLogger_Release(&logger);
assertNotNull(message, "Got null from metisMessage_CreateFromBuffer");
assertTrue(parcEventBuffer_GetLength(message->messageBytes) == sizeof(message_str),
"Length of internal buffer wrong, expected %zu got %zu",
sizeof(message_str),
parcEventBuffer_GetLength(message->messageBytes));
uint8_t *p = parcEventBuffer_Pullup(message->messageBytes, sizeof(message_str));
assertTrue(memcmp(p, message_str, sizeof(message_str)) == 0, "Internal buffer contents does not match test");
assertTrue(message->ingressConnectionId == 1, "IngressConnectionId wrong, expected %d got %u", 1, message->ingressConnectionId);
assertTrue(message->receiveTime == 2, "receiveTime wrong, expected %u got %" PRIu64, 2, message->receiveTime);
assertTrue(parcEventBuffer_GetLength(buff) == 0, "Origin buffer not drained, expected 0, got %zu", parcEventBuffer_GetLength(buff));
metisMessage_Release(&message);
parcEventBuffer_Destroy(&buff);
}
/**
* @function conn_readcb
* @abstract Event callback for reads
* @discussion
* Will read messages off the input. Continues reading as long as we
* can get a header to determine the next message length or as long as we
* can read a complete message.
*
* This function manipulates the read low water mark. (1) read a fixed header plus complete message,
* then set the low water mark to FIXED_HEADER_LEN. (2) read a fixed header, but not a complete
* message, then set low water mark to the total mesage length. Using the low water mark like this
* means the buffer event will only trigger on meaningful byte boundaries when we can get actual
* work done.
*
* @param <#param1#>
* @return <#return#>
*/
static void
_conn_readcb(PARCEventQueue *event, PARCEventType type, void *ioOpsVoid)
{
MetisIoOperations *ops = (MetisIoOperations *) ioOpsVoid;
_MetisStreamState *stream = (_MetisStreamState *) metisIoOperations_GetClosure(ops);
PARCEventBuffer *input = parcEventBuffer_GetQueueBufferInput(event);
// drain the input buffer
while (parcEventBuffer_GetLength(input) >= metisTlv_FixedHeaderLength() && parcEventBuffer_GetLength(input) >= stream->nextMessageLength) {
// this may set the stream->nextMessageLength
MetisMessage *message = _single_read(input, stream);
if (message) {
metisForwarder_Receive(stream->metis, message);
}
}
if (stream->nextMessageLength == 0) {
// we don't have the next header, so set it to the header length
metisStreamBuffer_SetWatermark(event, true, false, metisTlv_FixedHeaderLength(), 0);
} else {
// set it to the packet length
metisStreamBuffer_SetWatermark(event, true, false, stream->nextMessageLength, 0);
}
parcEventBuffer_Destroy(&input);
}
static void
_metisCliSession_ReadCallback(PARCEventQueue *event, PARCEventType type, void *cliSessionVoid)
{
assertTrue(type == PARCEventType_Read, "Illegal type: expected read event, got %d\n", type);
_MetisCommandLineInterface_Session *session = (_MetisCommandLineInterface_Session *) cliSessionVoid;
PARCEventBuffer *input = parcEventBuffer_GetQueueBufferInput(event);
while (parcEventBuffer_GetLength(input) > 0) {
size_t readLength = 0;
char *cmdline = parcEventBuffer_ReadLine(input, &readLength);
if (cmdline == NULL) {
// we have run out of input, we're done
parcEventBuffer_Destroy(&input);
return;
}
// we have a whole command line
bool success = _metisCliSession_ProcessCommand(session, cmdline);
parcEventBuffer_FreeLine(input, &cmdline);
if (!success) {
// the session is dead
parcEventBuffer_Destroy(&input);
return;
}
_metisCliSession_DisplayPrompt(session);
}
parcEventBuffer_Destroy(&input);
}
/**
* Parses the work buffer to extract packets
*
* The work buffer should be filled in with a set of tuples (bh_hdrlen, frame, pad).
* The pad extends each packet out to BPF_WORDALIGN.
*
* If the CCNxMessage PacketLength says it is larger than the read capture length (caplen),
* then this is an invalid packet and it will be discarded. This error will result in a
* ReadWorkBufferResult_TryAgain condition.
*
* struct bpf_hdr {
* struct BPF_TIMEVAL bh_tstamp; // time stamp
* bpf_u_int32 bh_caplen; // length of captured portion
* bpf_u_int32 bh_datalen; // original length of packet
* u_short bh_hdrlen; // length of bpf header (this struct plus alignment padding)
* }
*
* @param [in] ether An allocated Darwin ethernet.
* @param [in] readbuffer A user-provided read buffer.
*
* @retval ReadWorkBufferResult_Ok A frame was moved from workbuffer to readbuffer
* @retval ReadWorkBufferResult_Empty There's not enough bytes in the workbuffer
* @retval ReadWorkBufferResult_TryAgain (likely discard) caused this call to fail, but you should try again
*
* Example:
* @code
* <#example#>
* @endcode
*/
static _ReadWorkBufferResult
_darwinEthernet_ReadWorkBuffer(MetisGenericEther *ether, PARCEventBuffer *readbuffer)
{
_ReadWorkBufferResult result = ReadWorkBufferResult_Empty;
// Make sure we have linear memory for the BPF header
struct bpf_hdr *bpfHeader = (struct bpf_hdr *) parcEventBuffer_Pullup(ether->workBuffer, sizeof(struct bpf_hdr));
// make sure we have enough bytes to process the frame
// bpfHeader may be NULL if there are not sizeof(struct bpf_hdr) bytes available.
if (bpfHeader && parcEventBuffer_GetLength(ether->workBuffer) >= bpfHeader->bh_hdrlen + bpfHeader->bh_caplen) {
// (0) Save the needed fields from the bpf header
// (1) pop off the bpf header
// (2) move the iovec from work buffer to readBuffer.
// (3) remove any BPF_WORDALIGN padding to the start of the next packet
// (0) Save the needed fields from the bpf header
uint16_t hdrlen = bpfHeader->bh_hdrlen;
uint32_t caplen = bpfHeader->bh_caplen;
// (1) pop off the bpf header
parcEventBuffer_Read(ether->workBuffer, NULL, hdrlen);
// (1a) Determine the packet length from the fixed header and only transfer that many bytes
uint16_t packetlen = _getFrameLengthFromWorkBuffer(ether);
if (packetlen <= caplen) {
// (2) move the iovec from work buffer to readBuffer.
parcEventBuffer_ReadIntoBuffer(ether->workBuffer, readbuffer, packetlen);
// (2a) drain off any trailer (i.e. FCS)
parcEventBuffer_Read(ether->workBuffer, NULL, caplen - packetlen);
result = ReadWorkBufferResult_Ok;
} else {
if (metisLogger_IsLoggable(ether->logger, MetisLoggerFacility_IO, PARCLogLevel_Warning)) {
metisLogger_Log(ether->logger, MetisLoggerFacility_IO, PARCLogLevel_Warning, __func__,
"%s reading fd %d discard packetlen %u greater than caplen %u",
__func__, ether->etherSocket, packetlen, caplen);
}
// discard all of caplen
parcEventBuffer_Read(ether->workBuffer, NULL, caplen);
// tell the caller that this read failed, but they could try again.
result = ReadWorkBufferResult_TryAgain;
}
// (3) remove any BPF_WORDALIGN padding to the start of the next packet
size_t alignedLength = BPF_WORDALIGN(hdrlen + caplen);
size_t pad = alignedLength - hdrlen - caplen;
parcEventBuffer_Read(ether->workBuffer, NULL, pad);
}
return result;
}
bool
metisGenericEther_SendFrame(MetisGenericEther *ether, PARCEventBuffer *buffer)
{
assertNotNull(ether, "Parameter ether must be non-null");
size_t length = parcEventBuffer_GetLength(buffer);
int written = parcEventBuffer_WriteToFileDescriptor(buffer, ether->etherSocket, -1);
if (written == length) {
return true;
}
return false;
}
/*
* Reading a BPF packet will include the BPF header. Frame may include the FCS.
*/
bool
metisGenericEther_ReadNextFrame(MetisGenericEther *ether, PARCEventBuffer *readbuffer)
{
assertNotNull(ether, "Parameter ether must be non-null");
assertNotNull(readbuffer, "Parameter readbuffer must be non-null");
bool success = false;
if (metisLogger_IsLoggable(ether->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug)) {
metisLogger_Log(ether->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug, __func__,
"Workbuffer length %zu", __func__, parcEventBuffer_GetLength(ether->workBuffer));
}
// Do we already have something in our work buffer? If not, try to read something.
if (parcEventBuffer_GetLength(ether->workBuffer) == 0) {
_darwinEthernet_ReadSocket(ether);
}
success = _darwinEthernet_WorkBufferToReadBuffer(ether, readbuffer);
return success;
}
TransportMessage *
rtaComponent_GetMessage(PARCEventQueue *queue)
{
PARCEventBuffer *in = parcEventBuffer_GetQueueBufferInput(queue);
while (parcEventBuffer_GetLength(in) >= sizeof(TransportMessage *)) {
ssize_t len;
TransportMessage *tm;
RtaConnection *conn;
len = parcEventBuffer_Read(in, (void *)&tm, sizeof(&tm));
assertTrue(len == sizeof(TransportMessage *),
"parcEventBuffer_Read returned error");
// Is the transport message for an open connection?
conn = rtaConnection_GetFromTransport(tm);
assertNotNull(conn, "%s GetInfo returnd null connection\n", __func__);
if (DEBUG_OUTPUT) {
printf("%s queue %-12s tm %p\n",
__func__,
rtaProtocolStack_GetQueueName(rtaConnection_GetStack(conn), queue),
(void *) tm);
}
(void) rtaConnection_DecrementMessagesInQueue(conn);
if (rtaConnection_GetState(conn) != CONN_CLOSED) {
parcEventBuffer_Destroy(&in);
return tm;
}
// it's a closed connection
if (DEBUG_OUTPUT) {
printf("%s clearing connection %p reference in transport\n",
__func__, (void *) conn);
}
// should increment a drop counter (case 908)
transportMessage_Destroy(&tm);
}
parcEventBuffer_Destroy(&in);
return NULL;
}
/**
* @function metisStreamConnection_Send
* @abstract Non-destructive send of the message.
* @discussion
* Send uses metisMessage_CopyToStreamBuffer, which is a non-destructive write.
* The send may fail if there's no buffer space in the output queue.
*
* @param dummy is ignored. A stream has only one peer.
* @return <#return#>
*/
static bool
_metisStreamConnection_Send(MetisIoOperations *ops, const CPIAddress *dummy, MetisMessage *message)
{
assertNotNull(ops, "Parameter ops must be non-null");
assertNotNull(message, "Parameter message must be non-null");
_MetisStreamState *stream = (_MetisStreamState *) metisIoOperations_GetClosure(ops);
bool success = false;
if (stream->isUp) {
PARCEventBuffer *buffer = parcEventBuffer_GetQueueBufferOutput(stream->bufferEventVector);
size_t buffer_backlog = parcEventBuffer_GetLength(buffer);
parcEventBuffer_Destroy(&buffer);
if (buffer_backlog < OUTPUT_QUEUE_BYTES) {
if (metisLogger_IsLoggable(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug)) {
metisLogger_Log(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Debug, __func__,
"connid %u Writing %zu bytes to buffer with backlog %zu bytes",
stream->id,
metisMessage_Length(message),
buffer_backlog);
}
int failure = metisMessage_Write(stream->bufferEventVector, message);
if (failure == 0) {
success = true;
}
} else {
if (metisLogger_IsLoggable(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Warning)) {
metisLogger_Log(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Warning, __func__,
"connid %u Writing to buffer backlog %zu bytes DROP MESSAGE",
stream->id,
buffer_backlog);
}
}
} else {
if (metisLogger_IsLoggable(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Error)) {
metisLogger_Log(stream->logger, MetisLoggerFacility_IO, PARCLogLevel_Error, __func__,
"connid %u tried to send to down connection (isUp %d isClosed %d)",
stream->id,
stream->isUp,
stream->isClosed);
}
}
return success;
}
/**
* @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;
}
