decoder.c File Reference

Go to the source code of this file.

Functions
void	packet_decoder_reset (packet_decoder_t *decoder)
bool	packet_decoder_pending (const packet_decoder_t *decoder)
asciichat_error_t	packet_decoder_feed (packet_decoder_t *decoder, const void *data, size_t length, packet_decoder_fn emit, void *arg)

Function Documentation

packet_decoder_feed()

asciichat_error_t packet_decoder_feed	(	packet_decoder_t *	decoder,
		const void *	data,
		size_t	length,
		packet_decoder_fn	emit,
		void *	arg )

Definition at line 19 of file network/packet/decoder.c.

                                                                         {
  if (!decoder || (!data && length) || !emit || decoder->failed)
    return SET_ERRNO(ERROR_INVALID_PARAM, "Invalid packet decoder input");
  const uint8_t *input = data;
  while (length) {
    if (decoder->header_used < sizeof(packet_header_t)) {
      size_t take = MIN(length, sizeof(packet_header_t) - decoder->header_used);
      memcpy(decoder->header + decoder->header_used, input, take);
      decoder->header_used += take;
      input += take;
      length -= take;
      if (decoder->header_used != sizeof(packet_header_t))
        break;
      packet_header_t header;
      memcpy(&header, decoder->header, sizeof(header));
      size_t payload = NET_TO_HOST_U32(header.length);
      size_t limit = decoder->max_payload ? MIN(decoder->max_payload, MAX_PACKET_SIZE) : MAX_PACKET_SIZE;
      if (NET_TO_HOST_U64(header.magic) != PACKET_MAGIC || payload > limit) {
        decoder->failed = true;
        return SET_ERRNO(ERROR_NETWORK_PROTOCOL, "Invalid incremental packet header");
      }
      decoder->size = sizeof(header) + payload;
      buffer_workspace_t workspace = {.data = decoder->packet};
      if (buffer_workspace_reserve(&workspace, NULL, decoder->size) != ASCIICHAT_OK) {
        decoder->failed = true;
        return SET_ERRNO(ERROR_MEMORY, "Incremental packet exceeds buffer budget");
      }
      decoder->packet = workspace.data;
      memcpy(decoder->packet, &header, sizeof(header));
      decoder->used = sizeof(header);
    }
    size_t take = MIN(length, decoder->size - decoder->used);
    if (take)
      memcpy(decoder->packet + decoder->used, input, take);
    decoder->used += take;
    input += take;
    length -= take;
    if (decoder->used != decoder->size)
      break;
    asciichat_error_t result = packet_validate(decoder->packet, decoder->size, decoder->max_payload, NULL);
    if (result == ASCIICHAT_OK)
      result = emit(decoder->packet, decoder->size, arg);
    // The callback borrows this storage; retain it for the next framed packet.
    decoder->header_used = decoder->used = decoder->size = 0;
    if (result != ASCIICHAT_OK) {
      decoder->failed = true;
      return result;
    }
  }
  return ASCIICHAT_OK;
}

References ASCIICHAT_OK, buffer_workspace_reserve(), buffer_workspace_t::data, ERROR_INVALID_PARAM, ERROR_MEMORY, ERROR_NETWORK_PROTOCOL, packet_decoder_t::failed, packet_decoder_t::header, packet_decoder_t::header_used, MAX_PACKET_SIZE, packet_decoder_t::max_payload, MIN, NET_TO_HOST_U32, NET_TO_HOST_U64, packet_decoder_t::packet, PACKET_MAGIC, packet_validate(), SET_ERRNO, packet_decoder_t::size, and packet_decoder_t::used.

Referenced by quic_stream_read().

packet_decoder_pending()

bool packet_decoder_pending

(

const packet_decoder_t *

decoder

)

Definition at line 15 of file network/packet/decoder.c.

                                                             {
  return decoder && decoder->header_used != 0;
}

References packet_decoder_t::header_used.

Referenced by quic_stream_finish().

packet_decoder_reset()

void packet_decoder_reset

(

packet_decoder_t *

decoder

)

Definition at line 8 of file network/packet/decoder.c.

                                                     {
  if (decoder) {
    buffer_release(decoder->packet);
    memset(decoder, 0, sizeof(*decoder));
  }
}

References buffer_release, and packet_decoder_t::packet.

Referenced by quic_stream_reset().