TCP for IPv6

The TCP for IPv6 library provides functions for creating and manipulation TCP packets.

Functionality

Create TCP packets of any length
Create and extract TCP headers
Verify checksum of TCP packets

Example use

Include the libraries:

library nw_util;
context nw_util.nw_util_context;
library nw_ipv6;
context nw_ipv6.nw_ipv6_context;

Assume the variable v_payload contains the TCP payload. The variables are defined:

variable v_header      : t_tcp_header; -- TCP header record
variable v_ipv6_header : t_ipv6_header; -- IPv6 header record
variable v_tcp_pkt     : t_slv_arr(0 to 1500)(7 downto 0); -- byte array
variable v_len         : natural;

First setup the header, then calculate the total TCP packet length before creating the packet.

v_header                  := C_DEFAULT_TCP_HEADER; -- copy default header
v_header.seq_no           := x"1033010f"; -- change sequence number
v_ipv6_header             := C_DEFAULT_IPV6_HEADER; -- IPv6 header needed for pseudo header
v_ipv6_header.protocol    := C_TCP; -- set protocol
-- change other header fields as required...
v_len                     := f_tcpv6_create_pkt_len(v_ipv6_header, v_header, v_payload); -- calculate total packet length
v_tcp_pkt(0 to v_len - 1) := f_tcpv6_create_pkt(v_ipv6_header, v_header, v_payload); -- create the packet

The variable v_tcp_pkt is an 8-bit array. This can of course be rearranged to any word width with f_repack .

v_tcp_pkt_32 := f_repack(v_tcp_pkt, 32, C_MSB_FIRST); -- repack to 32bit words (padded with zeros if required)

See further examples in the test bench nw_ipv6_tb.vhd.

Table of Contents

TCP for IPv6

Functionality

Example use