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ipv4: Implement IPv4 TX

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This commit is contained in:
Markus Koch 2022-10-31 23:46:46 +01:00
parent a0c9df28f1
commit fdcb1cb719
4 changed files with 172 additions and 18 deletions
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77
design/top_hwitl.vhd
View File

@ -372,6 +372,65 @@ begin
end if;
end process udp;
tx_udp_p : block
type state_t is (IDLE, TX, DONE);
signal state : state_t;
constant PACKET : byte_vector := (
x"10", x"00", -- Source port
x"04", x"00", -- Destination port
x"00", x"15", -- Length
x"00", x"00", -- Checksum (not used)
x"48", x"65", x"6C", x"6C", x"6F", x"20", x"57", x"6F", x"72", x"6C", x"64", x"21", x"0a" -- Payload
);
signal sr : byte_vector(PACKET'range);
signal cnt : integer range 0 to sr'length - 1;
begin
tx_udp : process(clk, rst) is
begin
if rst then
state <= IDLE;
elsif rising_edge(clk) then
case state is
when IDLE =>
if button_n(0) = '0' then
state <= TX;
sr <= PACKET;
cnt <= sr'length - 1;
report "UDP: Start TX";
end if;
when TX =>
if ipv4_protocol_out(IPROT_UDP).tx_data_ack then
sr <= sr(sr'low + 1 to sr'high) & x"00";
if cnt = 0 then
state <= DONE;
else
cnt <= cnt - 1;
end if;
end if;
if ipv4_protocol_out(IPROT_UDP).tx_err_stb then
report "UDP: TX ERROR";
state <= DONE;
end if;
if ipv4_protocol_out(IPROT_UDP).tx_ok_stb then
report "UDP: TX OK stb in TX state -- that shouldn't happen, right?";
end if;
when DONE =>
null;
end case;
end if;
end process tx_udp;
ipv4_protocol_in(IPROT_UDP).tx_en <= '1' when state = TX else '0';
ipv4_protocol_in(IPROT_UDP).tx_ip_address <= (x"C0", x"A8", x"02", x"01");
ipv4_protocol_in(IPROT_UDP).tx_length <= to_unsigned(sr'length, 16);
ipv4_protocol_in(IPROT_UDP).tx_data <= sr(0);
end block tx_udp_p;
icmp : process(clk) is
begin
if rising_edge(clk) then
@ -381,22 +440,4 @@ begin
end if;
end process icmp;
arp_request_test : process(clk, rst) is
begin
if rst then
arp_in.arp_ip <= (x"C0", x"A8", x"02", x"01");
arp_in.arp_query_stb <= '0';
elsif rising_edge(clk) then
arp_in.arp_query_stb <= not button_n(0);
if arp_out.arp_ok_stb then
report "Found MAC: " & mac_to_string(arp_out.arp_mac);
end if;
if arp_out.arp_fail_stb then
report "ARP failed";
end if;
end if;
end process arp_request_test;
end architecture eth;

109
trashernet/trashernet_ipv4.vhd
View File

@ -135,4 +135,113 @@ begin
ipv4_out.rx_protocol <= sr_protocol;
end block rx;
tx : block
type state_t is (IDLE, ARP, CALC_CKS, HEADER, PAYLOAD);
signal state : state_t;
signal full_length : ipv4_length;
constant TTL : byte := x"40";
impure function get_header(checksum : std_logic_vector(15 downto 0)) return byte_vector is
begin
return --
byte_vector'(
x"45", x"00", byte(full_length(15 downto 8)), byte(full_length(7 downto 0)), -- Ver/IHL, DSCP/ECN, Len
x"00", x"00", x"00", x"00" -- Identification, Flags/FragOffset
) & TTL & ipv4_in.tx_protocol & checksum(15 downto 8) & checksum(7 downto 0) & -- TTL, Protocol, Header Checksum
ipv4_config.ip_address & -- Source IP
ipv4_in.tx_ip_address -- Destination IP
;
end function get_header;
constant PSEUDO_HEADER : byte_vector := get_header(x"0000");
signal sr : byte_vector(PSEUDO_HEADER'range);
signal byte_cnt : integer range 0 to sr'length - 1;
signal alt_byte : std_logic;
signal checksum : unsigned(20 downto 0); -- 20 Header fields -> 19 chances for carry -> 5 additional bits
signal checksum_ones : unsigned(15 downto 0);
begin
full_length <= PSEUDO_HEADER'length + ipv4_in.tx_length;
checksum_ones <= checksum(15 downto 0) + checksum(checksum'high downto 16);
tx_fsm : process(clk, rst) is
begin
if rst then
state <= IDLE;
ipv4_out.tx_data_ack <= '0';
arp_in.arp_query_stb <= '0';
ipv4_out.tx_err_stb <= '0';
elsif rising_edge(clk) then
arp_in.arp_query_stb <= '0';
ipv4_out.tx_data_ack <= '0';
ipv4_out.tx_err_stb <= '0';
if (ethernet_ii_out.tx_data_ack = '1') or (state = CALC_CKS) then
if byte_cnt > 0 then
byte_cnt <= byte_cnt - 1;
end if;
sr <= sr(sr'low + 1 to sr'high) & x"00";
end if;
case state is
when IDLE =>
if ipv4_in.tx_en then
arp_in.arp_query_stb <= '1';
state <= ARP;
end if;
when ARP =>
if arp_out.arp_ok_stb then
ethernet_ii_in.tx_mac_address <= arp_out.arp_mac;
byte_cnt <= sr'length - 1;
sr <= get_header(x"0000");
alt_byte <= '1';
checksum <= (others => '0');
state <= CALC_CKS;
end if;
if arp_out.arp_fail_stb then
ipv4_out.tx_err_stb <= '1';
-- Then we lock up in this state until tx_en is disabled
end if;
when CALC_CKS =>
alt_byte <= not alt_byte;
if alt_byte then
checksum <= checksum + unsigned(std_logic_vector'(sr(sr'low) & sr(sr'low + 1)));
else
if byte_cnt = 0 then
state <= HEADER;
byte_cnt <= sr'length - 1;
sr <= get_header(not std_logic_vector(checksum_ones));
end if;
end if;
when HEADER =>
if byte_cnt = 0 then
state <= PAYLOAD;
end if;
when PAYLOAD =>
if ethernet_ii_out.tx_data_ack then
sr(sr'low) <= ipv4_in.tx_data;
ipv4_out.tx_data_ack <= '1';
if not ipv4_in.tx_en then
state <= IDLE;
end if;
end if;
end case;
end if;
end process tx_fsm;
ethernet_ii_in.tx_data <= sr(sr'low);
ethernet_ii_in.tx_en <= '1' when (state = HEADER) or (state = PAYLOAD) else '0';
arp_in.arp_ip <= ipv4_in.tx_ip_address;
end block tx;
end architecture rtl;

1
trashernet/trashernet_ipv4prot.vhd
View File

@ -114,6 +114,7 @@ begin
ipv4_in.tx_data <= ipv4_protocol_in(tx_sel).tx_data;
ipv4_in.tx_en <= ipv4_protocol_in(tx_sel).tx_en;
ipv4_in.tx_ip_address <= ipv4_protocol_in(tx_sel).tx_ip_address;
ipv4_in.tx_length <= ipv4_protocol_in(tx_sel).tx_length;
ipv4_in.tx_protocol <= IPV4_PROTOCOLS(tx_sel);
end block demux;
end block tx;

3
trashernet/trashernet_pkg.vhd
View File

@ -142,6 +142,7 @@ package trashernet_pkg is
constant IPV4_PROTOCOL_ICMP : ipv4_protocol := x"01";
constant IPV4_PROTOCOL_TCP : ipv4_protocol := x"06";
constant IPV4_PROTOCOL_UDP : ipv4_protocol := x"11";
subtype ipv4_length is unsigned(15 downto 0);
type ipv4_out_t is record
rx_ip_address : ip_addr_t; -- Source IP address
@ -160,6 +161,7 @@ package trashernet_pkg is
type ipv4_in_t is record
tx_ip_address : ip_addr_t; -- Destination IP address
tx_protocol : ipv4_protocol; -- Transport Protocol
tx_length : ipv4_length; -- Length of payload
tx_data : byte; -- TX data
tx_en : std_logic; -- Start and continue transmitting
end record ipv4_in_t;
@ -179,6 +181,7 @@ package trashernet_pkg is
end record ipv4_protocol_out_t;
type ipv4_protocol_in_t is record
tx_ip_address : ip_addr_t; -- Destination IP address
tx_length : ipv4_length; -- Length of payload
tx_data : byte; -- TX data
tx_en : std_logic; -- Start and continue transmitting