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Alex Forencich authoredAlex Forencich authored
arp.v 17.52 KiB
/*
Copyright (c) 2014-2020 Alex Forencich
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// Language: Verilog 2001
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* ARP block for IPv4, ethernet frame interface
*/
module arp #
(
// Width of AXI stream interfaces in bits
parameter DATA_WIDTH = 8,
// Propagate tkeep signal
// If disabled, tkeep assumed to be 1'b1
parameter KEEP_ENABLE = (DATA_WIDTH>8),
// tkeep signal width (words per cycle)
parameter KEEP_WIDTH = (DATA_WIDTH/8),
// Log2 of ARP cache size
parameter CACHE_ADDR_WIDTH = 9,
// ARP request retry count
parameter REQUEST_RETRY_COUNT = 4,
// ARP request retry interval (in cycles)
parameter REQUEST_RETRY_INTERVAL = 125000000*2,
// ARP request timeout (in cycles)
parameter REQUEST_TIMEOUT = 125000000*30
)
(
input wire clk,
input wire rst,
/*
* Ethernet frame input
*/
input wire s_eth_hdr_valid,
output wire s_eth_hdr_ready,
input wire [47:0] s_eth_dest_mac,
input wire [47:0] s_eth_src_mac,
input wire [15:0] s_eth_type,
input wire [DATA_WIDTH-1:0] s_eth_payload_axis_tdata,
input wire [KEEP_WIDTH-1:0] s_eth_payload_axis_tkeep,
input wire s_eth_payload_axis_tvalid,
output wire s_eth_payload_axis_tready,
input wire s_eth_payload_axis_tlast,
input wire s_eth_payload_axis_tuser,
/*
* Ethernet frame output
*/
output wire m_eth_hdr_valid,
input wire m_eth_hdr_ready,
output wire [47:0] m_eth_dest_mac,
output wire [47:0] m_eth_src_mac,
output wire [15:0] m_eth_type,
output wire [DATA_WIDTH-1:0] m_eth_payload_axis_tdata,
output wire [KEEP_WIDTH-1:0] m_eth_payload_axis_tkeep,
output wire m_eth_payload_axis_tvalid,
input wire m_eth_payload_axis_tready,
output wire m_eth_payload_axis_tlast,
output wire m_eth_payload_axis_tuser,
/*
* ARP requests
*/
input wire arp_request_valid,
output wire arp_request_ready,
input wire [31:0] arp_request_ip,
output wire arp_response_valid,
input wire arp_response_ready,
output wire arp_response_error,
output wire [47:0] arp_response_mac,
/*
* Configuration
*/
input wire [47:0] local_mac,
input wire [31:0] local_ip,
input wire [31:0] gateway_ip,
input wire [31:0] subnet_mask,
input wire clear_cache
);
localparam [15:0]
ARP_OPER_ARP_REQUEST = 16'h0001,
ARP_OPER_ARP_REPLY = 16'h0002,
ARP_OPER_INARP_REQUEST = 16'h0008,
ARP_OPER_INARP_REPLY = 16'h0009;
wire incoming_frame_valid;
reg incoming_frame_ready;
wire [47:0] incoming_eth_dest_mac;
wire [47:0] incoming_eth_src_mac;
wire [15:0] incoming_eth_type;
wire [15:0] incoming_arp_htype;
wire [15:0] incoming_arp_ptype;
wire [7:0] incoming_arp_hlen;
wire [7:0] incoming_arp_plen;
wire [15:0] incoming_arp_oper;
wire [47:0] incoming_arp_sha;
wire [31:0] incoming_arp_spa;
wire [47:0] incoming_arp_tha;
wire [31:0] incoming_arp_tpa;
/*
* ARP frame processing
*/
arp_eth_rx #(
.DATA_WIDTH(DATA_WIDTH),
.KEEP_ENABLE(KEEP_ENABLE),
.KEEP_WIDTH(KEEP_WIDTH)
)
arp_eth_rx_inst (
.clk(clk),
.rst(rst),
// Ethernet frame input
.s_eth_hdr_valid(s_eth_hdr_valid), .s_eth_hdr_ready(s_eth_hdr_ready),
.s_eth_dest_mac(s_eth_dest_mac),
.s_eth_src_mac(s_eth_src_mac),
.s_eth_type(s_eth_type),
.s_eth_payload_axis_tdata(s_eth_payload_axis_tdata),
.s_eth_payload_axis_tkeep(s_eth_payload_axis_tkeep),
.s_eth_payload_axis_tvalid(s_eth_payload_axis_tvalid),
.s_eth_payload_axis_tready(s_eth_payload_axis_tready),
.s_eth_payload_axis_tlast(s_eth_payload_axis_tlast),
.s_eth_payload_axis_tuser(s_eth_payload_axis_tuser),
// ARP frame output
.m_frame_valid(incoming_frame_valid),
.m_frame_ready(incoming_frame_ready),
.m_eth_dest_mac(incoming_eth_dest_mac),
.m_eth_src_mac(incoming_eth_src_mac),
.m_eth_type(incoming_eth_type),
.m_arp_htype(incoming_arp_htype),
.m_arp_ptype(incoming_arp_ptype),
.m_arp_hlen(incoming_arp_hlen),
.m_arp_plen(incoming_arp_plen),
.m_arp_oper(incoming_arp_oper),
.m_arp_sha(incoming_arp_sha),
.m_arp_spa(incoming_arp_spa),
.m_arp_tha(incoming_arp_tha),
.m_arp_tpa(incoming_arp_tpa),
// Status signals
.busy(),
.error_header_early_termination(),
.error_invalid_header()
);
reg outgoing_frame_valid_reg = 1'b0, outgoing_frame_valid_next;
wire outgoing_frame_ready;
reg [47:0] outgoing_eth_dest_mac_reg = 48'd0, outgoing_eth_dest_mac_next;
reg [15:0] outgoing_arp_oper_reg = 16'd0, outgoing_arp_oper_next;
reg [47:0] outgoing_arp_tha_reg = 48'd0, outgoing_arp_tha_next;
reg [31:0] outgoing_arp_tpa_reg = 32'd0, outgoing_arp_tpa_next;
arp_eth_tx #(
.DATA_WIDTH(DATA_WIDTH),
.KEEP_ENABLE(KEEP_ENABLE),
.KEEP_WIDTH(KEEP_WIDTH)
)
arp_eth_tx_inst (
.clk(clk),
.rst(rst),
// ARP frame input
.s_frame_valid(outgoing_frame_valid_reg),
.s_frame_ready(outgoing_frame_ready),
.s_eth_dest_mac(outgoing_eth_dest_mac_reg),
.s_eth_src_mac(local_mac),
.s_eth_type(16'h0806),
.s_arp_htype(16'h0001),
.s_arp_ptype(16'h0800),
.s_arp_oper(outgoing_arp_oper_reg),
.s_arp_sha(local_mac),
.s_arp_spa(local_ip),
.s_arp_tha(outgoing_arp_tha_reg),
.s_arp_tpa(outgoing_arp_tpa_reg),
// Ethernet frame output
.m_eth_hdr_valid(m_eth_hdr_valid),
.m_eth_hdr_ready(m_eth_hdr_ready),
.m_eth_dest_mac(m_eth_dest_mac),
.m_eth_src_mac(m_eth_src_mac),
.m_eth_type(m_eth_type),
.m_eth_payload_axis_tdata(m_eth_payload_axis_tdata),
.m_eth_payload_axis_tkeep(m_eth_payload_axis_tkeep),
.m_eth_payload_axis_tvalid(m_eth_payload_axis_tvalid),
.m_eth_payload_axis_tready(m_eth_payload_axis_tready),
.m_eth_payload_axis_tlast(m_eth_payload_axis_tlast), .m_eth_payload_axis_tuser(m_eth_payload_axis_tuser),
// Status signals
.busy()
);
reg cache_query_request_valid_reg = 1'b0, cache_query_request_valid_next;
reg [31:0] cache_query_request_ip_reg = 32'd0, cache_query_request_ip_next;
wire cache_query_response_valid;
wire cache_query_response_error;
wire [47:0] cache_query_response_mac;
reg cache_write_request_valid_reg = 1'b0, cache_write_request_valid_next;
reg [31:0] cache_write_request_ip_reg = 32'd0, cache_write_request_ip_next;
reg [47:0] cache_write_request_mac_reg = 48'd0, cache_write_request_mac_next;
/*
* ARP cache
*/
arp_cache #(
.CACHE_ADDR_WIDTH(CACHE_ADDR_WIDTH)
)
arp_cache_inst (
.clk(clk),
.rst(rst),
// Query cache
.query_request_valid(cache_query_request_valid_reg),
.query_request_ready(),
.query_request_ip(cache_query_request_ip_reg),
.query_response_valid(cache_query_response_valid),
.query_response_ready(1'b1),
.query_response_error(cache_query_response_error),
.query_response_mac(cache_query_response_mac),
// Write cache
.write_request_valid(cache_write_request_valid_reg),
.write_request_ready(),
.write_request_ip(cache_write_request_ip_reg),
.write_request_mac(cache_write_request_mac_reg),
// Configuration
.clear_cache(clear_cache)
);
reg arp_request_operation_reg = 1'b0, arp_request_operation_next;
reg arp_request_ready_reg = 1'b0, arp_request_ready_next;
reg [31:0] arp_request_ip_reg = 32'd0, arp_request_ip_next;
reg arp_response_valid_reg = 1'b0, arp_response_valid_next;
reg arp_response_error_reg = 1'b0, arp_response_error_next;
reg [47:0] arp_response_mac_reg = 48'd0, arp_response_mac_next;
reg [5:0] arp_request_retry_cnt_reg = 6'd0, arp_request_retry_cnt_next;
reg [35:0] arp_request_timer_reg = 36'd0, arp_request_timer_next;
assign arp_request_ready = arp_request_ready_reg;
assign arp_response_valid = arp_response_valid_reg;
assign arp_response_error = arp_response_error_reg;
assign arp_response_mac = arp_response_mac_reg;
always @* begin
incoming_frame_ready = 1'b0;
outgoing_frame_valid_next = outgoing_frame_valid_reg && !outgoing_frame_ready;
outgoing_eth_dest_mac_next = outgoing_eth_dest_mac_reg;
outgoing_arp_oper_next = outgoing_arp_oper_reg;
outgoing_arp_tha_next = outgoing_arp_tha_reg;
outgoing_arp_tpa_next = outgoing_arp_tpa_reg;
cache_query_request_valid_next = 1'b0;
cache_query_request_ip_next = cache_query_request_ip_reg;
cache_write_request_valid_next = 1'b0;
cache_write_request_mac_next = cache_write_request_mac_reg;
cache_write_request_ip_next = cache_write_request_ip_reg;
arp_request_ready_next = 1'b0;
arp_request_ip_next = arp_request_ip_reg;
arp_request_operation_next = arp_request_operation_reg;
arp_request_retry_cnt_next = arp_request_retry_cnt_reg;
arp_request_timer_next = arp_request_timer_reg;
arp_response_valid_next = arp_response_valid_reg && !arp_response_ready;
arp_response_error_next = 1'b0;
arp_response_mac_next = 48'd0;
// manage incoming frames
incoming_frame_ready = outgoing_frame_ready;
if (incoming_frame_valid && incoming_frame_ready) begin
if (incoming_eth_type == 16'h0806 && incoming_arp_htype == 16'h0001 && incoming_arp_ptype == 16'h0800) begin
// store sender addresses in cache
cache_write_request_valid_next = 1'b1;
cache_write_request_ip_next = incoming_arp_spa;
cache_write_request_mac_next = incoming_arp_sha;
if (incoming_arp_oper == ARP_OPER_ARP_REQUEST) begin
// ARP request
if (incoming_arp_tpa == local_ip) begin
// send reply frame to valid incoming request
outgoing_frame_valid_next = 1'b1;
outgoing_eth_dest_mac_next = incoming_eth_src_mac;
outgoing_arp_oper_next = ARP_OPER_ARP_REPLY;
outgoing_arp_tha_next = incoming_arp_sha;
outgoing_arp_tpa_next = incoming_arp_spa;
end
end else if (incoming_arp_oper == ARP_OPER_INARP_REQUEST) begin
// INARP request
if (incoming_arp_tha == local_mac) begin
// send reply frame to valid incoming request
outgoing_frame_valid_next = 1'b1;
outgoing_eth_dest_mac_next = incoming_eth_src_mac;
outgoing_arp_oper_next = ARP_OPER_INARP_REPLY;
outgoing_arp_tha_next = incoming_arp_sha;
outgoing_arp_tpa_next = incoming_arp_spa;
end
end
end
end
// manage ARP lookup requests
if (arp_request_operation_reg) begin
arp_request_ready_next = 1'b0;
cache_query_request_valid_next = 1'b1;
arp_request_timer_next = arp_request_timer_reg - 1;
// if we got a response, it will go in the cache, so when the query succeds, we're done
if (cache_query_response_valid && !cache_query_response_error) begin
arp_request_operation_next = 1'b0;
cache_query_request_valid_next = 1'b0;
arp_response_valid_next = 1'b1;
arp_response_error_next = 1'b0;
arp_response_mac_next = cache_query_response_mac;
end
// timer timeout
if (arp_request_timer_reg == 0) begin
if (arp_request_retry_cnt_reg > 0) begin
// have more retries
// send ARP request frame
outgoing_frame_valid_next = 1'b1;
outgoing_eth_dest_mac_next = 48'hffffffffffff;
outgoing_arp_oper_next = ARP_OPER_ARP_REQUEST;
outgoing_arp_tha_next = 48'h000000000000;
outgoing_arp_tpa_next = arp_request_ip_reg;
arp_request_retry_cnt_next = arp_request_retry_cnt_reg - 1; if (arp_request_retry_cnt_reg > 1) begin
arp_request_timer_next = REQUEST_RETRY_INTERVAL;
end else begin
arp_request_timer_next = REQUEST_TIMEOUT;
end
end else begin
// out of retries
arp_request_operation_next = 1'b0;
arp_response_valid_next = 1'b1;
arp_response_error_next = 1'b1;
cache_query_request_valid_next = 1'b0;
end
end
end else begin
arp_request_ready_next = !arp_response_valid_next;
if (cache_query_request_valid_reg) begin
cache_query_request_valid_next = 1'b1;
if (cache_query_response_valid) begin
if (cache_query_response_error) begin
arp_request_operation_next = 1'b1;
// send ARP request frame
outgoing_frame_valid_next = 1'b1;
outgoing_eth_dest_mac_next = 48'hffffffffffff;
outgoing_arp_oper_next = ARP_OPER_ARP_REQUEST;
outgoing_arp_tha_next = 48'h000000000000;
outgoing_arp_tpa_next = arp_request_ip_reg;
arp_request_retry_cnt_next = REQUEST_RETRY_COUNT-1;
arp_request_timer_next = REQUEST_RETRY_INTERVAL;
end else begin
cache_query_request_valid_next = 1'b0;
arp_response_valid_next = 1'b1;
arp_response_error_next = 1'b0;
arp_response_mac_next = cache_query_response_mac;
end
end
end else if (arp_request_valid && arp_request_ready) begin
if (arp_request_ip == 32'hffffffff) begin
// broadcast address; use broadcast MAC address
arp_response_valid_next = 1'b1;
arp_response_error_next = 1'b0;
arp_response_mac_next = 48'hffffffffffff;
end else if (((arp_request_ip ^ gateway_ip) & subnet_mask) == 0) begin
// within subnet
// (no bits differ between request IP and gateway IP where subnet mask is set)
if (~(arp_request_ip | subnet_mask) == 0) begin
// broadcast address; use broadcast MAC address
// (all bits in request IP set where subnet mask is clear)
arp_response_valid_next = 1'b1;
arp_response_error_next = 1'b0;
arp_response_mac_next = 48'hffffffffffff;
end else begin
// unicast address; look up IP directly
cache_query_request_valid_next = 1'b1;
cache_query_request_ip_next = arp_request_ip;
arp_request_ip_next = arp_request_ip;
end
end else begin
// outside of subnet, so look up gateway address
cache_query_request_valid_next = 1'b1;
cache_query_request_ip_next = gateway_ip;
arp_request_ip_next = gateway_ip;
end
end
end
end
always @(posedge clk) begin
if (rst) begin
outgoing_frame_valid_reg <= 1'b0;
cache_query_request_valid_reg <= 1'b0; cache_write_request_valid_reg <= 1'b0;
arp_request_ready_reg <= 1'b0;
arp_request_operation_reg <= 1'b0;
arp_request_retry_cnt_reg <= 6'd0;
arp_request_timer_reg <= 36'd0;
arp_response_valid_reg <= 1'b0;
end else begin
outgoing_frame_valid_reg <= outgoing_frame_valid_next;
cache_query_request_valid_reg <= cache_query_request_valid_next;
cache_write_request_valid_reg <= cache_write_request_valid_next;
arp_request_ready_reg <= arp_request_ready_next;
arp_request_operation_reg <= arp_request_operation_next;
arp_request_retry_cnt_reg <= arp_request_retry_cnt_next;
arp_request_timer_reg <= arp_request_timer_next;
arp_response_valid_reg <= arp_response_valid_next;
end
cache_query_request_ip_reg <= cache_query_request_ip_next;
outgoing_eth_dest_mac_reg <= outgoing_eth_dest_mac_next;
outgoing_arp_oper_reg <= outgoing_arp_oper_next;
outgoing_arp_tha_reg <= outgoing_arp_tha_next;
outgoing_arp_tpa_reg <= outgoing_arp_tpa_next;
cache_write_request_mac_reg <= cache_write_request_mac_next;
cache_write_request_ip_reg <= cache_write_request_ip_next;
arp_request_ip_reg <= arp_request_ip_next;
arp_response_error_reg <= arp_response_error_next;
arp_response_mac_reg <= arp_response_mac_next;
end
endmodule
`resetall