void tcp_packet_handler(void)
{
msg_t m_recv_ip, m_send_ip;
ipv6_hdr_t *ipv6_header;
tcp_hdr_t *tcp_header;
uint8_t *payload;
socket_internal_t *tcp_socket = NULL;
uint16_t chksum;
while (1) {
msg_receive(&m_recv_ip);
ipv6_header = ((ipv6_hdr_t *)m_recv_ip.content.ptr);
tcp_header = ((tcp_hdr_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN));
#ifdef TCP_HC
tcp_socket = decompress_tcp_packet(ipv6_header);
#else
switch_tcp_packet_byte_order(tcp_header);
tcp_socket = get_tcp_socket(ipv6_header, tcp_header);
#endif
chksum = tcp_csum(ipv6_header, tcp_header);
payload = (uint8_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN + tcp_header->data_offset * 4);
if ((chksum == 0xffff) && (tcp_socket != NULL)) {
#ifdef TCP_HC
update_tcp_hc_context(true, tcp_socket, tcp_header);
#endif
/* Remove reserved bits from tcp flags field */
uint8_t tcp_flags = tcp_header->reserved_flags;
switch (tcp_flags) {
case TCP_ACK: {
/* only ACK Bit set */
uint8_t tcp_payload_len = NTOHS(ipv6_header->length) - TCP_HDR_LEN;
uint8_t state = tcp_socket->socket_values.tcp_control.state;
if ((tcp_payload_len > 0) && (state == TCP_ESTABLISHED)) {
/* handle data segments only when the connection was established successfully */
handle_tcp_no_flags_packet(ipv6_header, tcp_header, tcp_socket, payload, tcp_payload_len);
}
else if (tcp_payload_len == 0
&& (state == TCP_ESTABLISHED || state == TCP_SYN_RCVD
|| state == TCP_CLOSING || state == TCP_LAST_ACK)) {
/* no payload, acknowledging data only */
handle_tcp_ack_packet(ipv6_header, tcp_header, tcp_socket);
}
break;
}
case TCP_RST: {
printf("RST Bit set!\n");
/* only RST Bit set */
handle_tcp_rst_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_SYN: {
/* only SYN Bit set, look for matching, listening socket
* and request new queued socket */
printf("SYN Bit set!\n");
handle_tcp_syn_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_SYN_ACK: {
/* only SYN and ACK Bit set, complete three way handshake
* when socket in state TCP_SYN_SENT */
handle_tcp_syn_ack_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_FIN_ACK: {
if (tcp_socket->socket_values.tcp_control.state == TCP_ESTABLISHED) {
/* this is the first FIN */
printf("FIN ACK Bit set!\n");
handle_tcp_fin_packet(ipv6_header, tcp_header, tcp_socket);
}
else {
/* this is the response to FIN */
handle_tcp_fin_ack_packet(ipv6_header, tcp_header, tcp_socket);
}
break;
}
default: {
printf("Unable to process the incoming segment!\n");
}
}
}
else {
printf("Wrong checksum (%x) or no corresponding socket found!\n",
chksum);
printArrayRange(((uint8_t *)ipv6_header), IPV6_HDR_LEN +
NTOHS(ipv6_header->length), "Incoming");
print_tcp_status(INC_PACKET, ipv6_header, tcp_header,
&tcp_socket->socket_values);
}
msg_reply(&m_recv_ip, &m_send_ip);
}
}
void tcp_packet_handler(void)
{
msg_t m_recv_ip, m_send_ip;
ipv6_hdr_t *ipv6_header;
tcp_hdr_t *tcp_header;
uint8_t *payload;
socket_internal_t *tcp_socket = NULL;
uint16_t chksum;
while (1) {
msg_receive(&m_recv_ip);
ipv6_header = ((ipv6_hdr_t *)m_recv_ip.content.ptr);
tcp_header = ((tcp_hdr_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN));
#ifdef TCP_HC
tcp_socket = decompress_tcp_packet(ipv6_header);
#else
switch_tcp_packet_byte_order(tcp_header);
tcp_socket = get_tcp_socket(ipv6_header, tcp_header);
#endif
chksum = tcp_csum(ipv6_header, tcp_header);
payload = (uint8_t *)(m_recv_ip.content.ptr + IPV6_HDR_LEN +
tcp_header->dataOffset_reserved * 4);
if ((chksum == 0xffff) && (tcp_socket != NULL)) {
#ifdef TCP_HC
update_tcp_hc_context(true, tcp_socket, tcp_header);
#endif
/* Remove reserved bits from tcp flags field */
uint8_t tcp_flags = tcp_header->reserved_flags & REMOVE_RESERVED;
switch(tcp_flags) {
case TCP_ACK: {
/* only ACK Bit set */
handle_tcp_ack_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_RST: {
printf("RST Bit set!\n");
/* only RST Bit set */
handle_tcp_rst_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_SYN: {
/* only SYN Bit set, look for matching, listening socket
* and request new queued socket */
printf("SYN Bit set!\n");
handle_tcp_syn_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_SYN_ACK: {
/* only SYN and ACK Bit set, complete three way handshake
* when socket in state SYN_SENT */
handle_tcp_syn_ack_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_FIN: {
printf("FIN Bit set!\n");
/* only FIN Bit set */
handle_tcp_fin_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
case TCP_FIN_ACK: {
printf("FIN ACK Bit set!\n");
/* only FIN and ACK Bit set */
handle_tcp_fin_ack_packet(ipv6_header, tcp_header, tcp_socket);
break;
}
default: {
handle_tcp_no_flags_packet(ipv6_header, tcp_header,
tcp_socket, payload);
}
}
}
else {
printf("Wrong checksum (%x) or no corresponding socket found!\n",
chksum);
printArrayRange(((uint8_t *)ipv6_header), IPV6_HDR_LEN +
ipv6_header->length, "Incoming");
print_tcp_status(INC_PACKET, ipv6_header, tcp_header,
&tcp_socket->socket_values);
}
msg_reply(&m_recv_ip, &m_send_ip);
}
}