/* return TRUE if the packet should be retransmitted */
gboolean udp_processPacket(UDP* udp, Packet* packet) {
MAGIC_ASSERT(udp);
/* UDP packet contains data for user and can be buffered immediately */
if(packet_getPayloadLength(packet) > 0) {
return socket_addToInputBuffer((Socket*)udp, packet);
}
return FALSE;
}
void udp_processPacket(UDP* udp, Packet* packet) {
MAGIC_ASSERT(udp);
/* UDP packet contains data for user and can be buffered immediately */
if(packet_getPayloadLength(packet) > 0) {
if(!socket_addToInputBuffer((Socket*)udp, packet)) {
packet_addDeliveryStatus(packet, PDS_RCV_SOCKET_DROPPED);
}
}
}
static void _tcp_flush(TCP* tcp) {
MAGIC_ASSERT(tcp);
/* make sure our information is up to date */
_tcp_updateReceiveWindow(tcp);
_tcp_updateSendWindow(tcp);
/* flush packets that can now be sent to socket */
while(g_queue_get_length(tcp->throttledOutput) > 0) {
/* get the next throttled packet, in sequence order */
Packet* packet = g_queue_pop_head(tcp->throttledOutput);
/* break out if we have no packets left */
if(!packet) {
break;
}
guint length = packet_getPayloadLength(packet);
if(length > 0) {
PacketTCPHeader header;
packet_getTCPHeader(packet, &header);
/* we cant send it if our window is too small */
gboolean fitsInWindow = (header.sequence < (tcp->send.unacked + tcp->send.window)) ? TRUE : FALSE;
/* we cant send it if we dont have enough space */
gboolean fitsInBuffer = (length <= socket_getOutputBufferSpace(&(tcp->super))) ? TRUE : FALSE;
if(!fitsInBuffer || !fitsInWindow) {
/* we cant send the packet yet */
g_queue_push_head(tcp->throttledOutput, packet);
break;
} else {
/* we will send: store length in virtual retransmission buffer
* so we can reduce buffer space consumed when we receive the ack */
_tcp_addRetransmit(tcp, header.sequence, length);
}
}
/* packet is sendable, we removed it from out buffer */
tcp->throttledOutputLength -= length;
/* update TCP header to our current advertised window and acknowledgement */
packet_updateTCP(packet, tcp->receive.next, tcp->receive.window);
/* keep track of the last things we sent them */
tcp->send.lastAcknowledgement = tcp->receive.next;
tcp->send.lastWindow = tcp->receive.window;
/* socket will queue it ASAP */
gboolean success = socket_addToOutputBuffer(&(tcp->super), packet);
/* we already checked for space, so this should always succeed */
g_assert(success);
}
/* any packets now in order can be pushed to our user input buffer */
while(g_queue_get_length(tcp->unorderedInput) > 0) {
Packet* packet = g_queue_pop_head(tcp->unorderedInput);
PacketTCPHeader header;
packet_getTCPHeader(packet, &header);
if(header.sequence == tcp->receive.next) {
/* move from the unordered buffer to user input buffer */
gboolean fitInBuffer = socket_addToInputBuffer(&(tcp->super), packet);
if(fitInBuffer) {
tcp->unorderedInputLength -= packet_getPayloadLength(packet);
(tcp->receive.next)++;
continue;
}
}
/* we could not buffer it because its out of order or we have no space */
g_queue_push_head(tcp->unorderedInput, packet);
break;
}
/* check if user needs an EOF signal */
gboolean wantsEOF = ((tcp->flags & TCPF_LOCAL_CLOSED) || (tcp->flags & TCPF_REMOTE_CLOSED)) ? TRUE : FALSE;
if(wantsEOF) {
/* if anyone closed, can't send anymore */
tcp->error |= TCPE_SEND_EOF;
if((tcp->receive.next >= tcp->receive.end) && !(tcp->flags & TCPF_EOF_SIGNALED)) {
/* user needs to read a 0 so it knows we closed */
tcp->error |= TCPE_RECEIVE_EOF;
descriptor_adjustStatus((Descriptor*)tcp, DS_READABLE, TRUE);
}
}
}
