int write_serial_packet(serial_source src, const void *packet, int len)
/* Effects: writes len byte packet to serial source src
Returns: 0 if packet successfully written, 1 if successfully written
but not acknowledged, -1 otherwise
*/
{
struct timeval deadline;
src->send.seqno++;
if (write_framed_packet(src, P_PACKET_ACK, src->send.seqno, packet, len) < 0)
return -1;
gettimeofday(&deadline, NULL);
add_timeval(&deadline, ACK_TIMEOUT);
for (;;)
{
struct packet_list *entry;
read_and_process(src);
entry = pop_protocol_packet(src, P_ACK);
if (entry)
{
uint8_t acked = entry->packet[0];
free(entry->packet);
free(entry);
if (acked == src->send.seqno)
return 0;
}
else if (source_wait(src, &deadline) < 0)
return 1;
}
}
static void process_packet(serial_source src, uint8_t *packet, int len)
{
int packet_type = packet[0], offset = 1;
if (packet_type == P_PACKET_ACK)
{
/* send ack */
write_framed_packet(src, P_ACK, packet[1], NULL, 0);
/* And merge with un-acked packets */
packet_type = P_PACKET_NO_ACK;
offset = 2;
}
/* packet must remain a valid pointer to pass to free. So we move the
data rather than pass an internal pointer */
memmove(packet, packet + offset, len - offset);
push_protocol_packet(src, packet_type, packet, len - offset);
}