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Diffstat (limited to 'fpga/usrp3/lib/packet_proc/arp_responder/arp_responder.vhd')
| -rw-r--r-- | fpga/usrp3/lib/packet_proc/arp_responder/arp_responder.vhd | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/fpga/usrp3/lib/packet_proc/arp_responder/arp_responder.vhd b/fpga/usrp3/lib/packet_proc/arp_responder/arp_responder.vhd new file mode 100644 index 000000000..8481132c6 --- /dev/null +++ b/fpga/usrp3/lib/packet_proc/arp_responder/arp_responder.vhd @@ -0,0 +1,204 @@ +-- +-- Copyright 2019 Ettus Research, A National Instruments brand +-- +-- SPDX-License-Identifier: LGPL-3.0 +-- +-- Module: arp_responder +-- Description: Processing IP to send replies for ARP frames (for IPv4) +-- arp_responder checks the incoming ARP frame against the input port ip_addr, +-- and if the frame is a request for this module's ip_addr, the module will +-- format an ARP reply and send it on the outgoing AXI-S interface. +-- +-- mac_addr and ip_addr must be kept stable for this module to function. They +-- are not registered within the IP. +-- +-- s_axis_tuser indicates there is an error in the packet, and it should be discarded + +library ieee; +use ieee.std_logic_1164.all; +use ieee.numeric_std.all; + +entity arp_responder is +port ( + aclk : in std_logic; + aresetn : in std_logic; + mac_addr : in std_logic_vector(47 downto 0); + ip_addr : in std_logic_vector(31 downto 0); + s_axis_tdata : in std_logic_vector(63 downto 0); + s_axis_tvalid : in std_logic; + s_axis_tready : out std_logic; + s_axis_tkeep : in std_logic_vector(7 downto 0); + s_axis_tlast : in std_logic; + s_axis_tuser : in std_logic; + m_axis_tdata : out std_logic_vector(63 downto 0); + m_axis_tvalid : out std_logic; + m_axis_tready : in std_logic; + m_axis_tkeep : out std_logic_vector(7 downto 0); + m_axis_tlast : out std_logic; + m_axis_tuser : out std_logic +); +end arp_responder; + +architecture arch of arp_responder is + type pkt_state_t is (PKT_IDLE, PKT_RECV, PKT_SEND, PKT_DROP); + signal pkt_state : pkt_state_t; + signal pkt_recv_count : unsigned(3 downto 0); + signal pkt_send_count : unsigned(3 downto 0); + + --All of these are LSB-0 for bits, but first byte transmitted is byte 0 + -- In ChipScope, bytes will appear swapped versus typical diagrams + signal src_mac_be : std_logic_vector(47 downto 0); + signal sender_hw_addr_be : std_logic_vector(47 downto 0); + signal sender_protocol_addr_be : std_logic_vector(31 downto 0); + signal target_protocol_addr_be : std_logic_vector(31 downto 0); + signal ip_addr_be : std_logic_vector(31 downto 0); +begin + m_axis_tuser <= '0'; + m_axis_tvalid <= '1' when (pkt_state = PKT_SEND) else '0'; + ip_addr_be <= ip_addr(7 downto 0) & ip_addr(15 downto 8) & + ip_addr(23 downto 16) & ip_addr(31 downto 24); + + s_axis_tready <= '1' when (pkt_state = PKT_IDLE) or (pkt_state = PKT_RECV) or (pkt_state = PKT_DROP) + else '0'; + + tx_reply : process (src_mac_be, mac_addr, ip_addr, sender_hw_addr_be, + sender_protocol_addr_be, pkt_send_count) + begin + m_axis_tdata <= (others => 'X'); + m_axis_tkeep <= (others => '1'); + m_axis_tlast <= '0'; + case (to_integer(pkt_send_count)) is + when 0 => + m_axis_tdata(47 downto 0) <= src_mac_be; + m_axis_tdata(63 downto 48) <= mac_addr(39 downto 32) & mac_addr(47 downto 40); + m_axis_tkeep <= X"FF"; + m_axis_tlast <= '0'; + when 1 => + m_axis_tdata(31 downto 0) <= mac_addr(7 downto 0) & mac_addr(15 downto 8) & + mac_addr(23 downto 16) & mac_addr(31 downto 24); + m_axis_tdata(47 downto 32) <= X"0608"; + m_axis_tdata(63 downto 48) <= X"0100"; + m_axis_tkeep <= X"FF"; + m_axis_tlast <= '0'; + when 2 => + m_axis_tdata(15 downto 0) <= X"0008"; --PTYPE + m_axis_tdata(23 downto 16) <= X"06"; --HLEN + m_axis_tdata(31 downto 24) <= X"04"; --PLEN + m_axis_tdata(47 downto 32) <= X"0200"; --OPER + m_axis_tdata(63 downto 48) <= mac_addr(39 downto 32) & mac_addr(47 downto 40); --SHA + m_axis_tkeep <= X"FF"; + m_axis_tlast <= '0'; + when 3 => + m_axis_tdata(31 downto 0) <= mac_addr(7 downto 0) & mac_addr(15 downto 8) & + mac_addr(23 downto 16) & mac_addr(31 downto 24); --SHA + m_axis_tdata(63 downto 32) <= ip_addr(7 downto 0) & ip_addr(15 downto 8) & + ip_addr(23 downto 16) & ip_addr(31 downto 24); --SPA + m_axis_tkeep <= X"FF"; + m_axis_tlast <= '0'; + when 4 => + m_axis_tdata(47 downto 0) <= sender_hw_addr_be; --THA + m_axis_tdata(63 downto 48) <= sender_protocol_addr_be(15 downto 0); --TPA + m_axis_tkeep <= X"FF"; + m_axis_tlast <= '0'; + when 5 => + m_axis_tdata(15 downto 0) <= sender_protocol_addr_be(31 downto 16); --TPA + m_axis_tdata(63 downto 16) <= (others => '0'); + m_axis_tkeep <= X"03"; + m_axis_tlast <= '1'; + when others => + null; + end case; + end process; + + process (aclk) + variable pkt_nonmatch : boolean := false; + begin + if rising_edge(aclk) then + case (pkt_state) is + when PKT_IDLE => + if (s_axis_tvalid = '1') and (s_axis_tlast = '0') and (s_axis_tuser = '0') then + pkt_state <= PKT_RECV; + pkt_recv_count <= to_unsigned(1, pkt_recv_count'length); + src_mac_be(15 downto 0) <= s_axis_tdata(63 downto 48); + end if; + when PKT_RECV => + pkt_nonmatch := false; + + pkt_send_count <= to_unsigned(0, pkt_send_count'length); + + if (s_axis_tvalid = '1') and (s_axis_tuser = '1') then + pkt_nonmatch := true; + elsif (s_axis_tvalid = '1') and (s_axis_tuser = '0') then + if (to_integer(pkt_recv_count) < 7) then + pkt_recv_count <= pkt_recv_count + 1; + end if; + + case (to_integer(pkt_recv_count)) is + when 1 => + src_mac_be(47 downto 16) <= s_axis_tdata(31 downto 0); + if (s_axis_tdata(47 downto 32) /= X"0608") or --eth_type + (s_axis_tdata(63 downto 48) /= X"0100") or --HTYPE + (s_axis_tlast = '1') then + pkt_nonmatch := true; + end if; + when 2 => + sender_hw_addr_be(15 downto 0) <= s_axis_tdata(63 downto 48); + if (s_axis_tdata(15 downto 0) /= X"0008") or --PTYPE + (s_axis_tdata(23 downto 16) /= X"06") or --HLEN + (s_axis_tdata(31 downto 24) /= X"04") or --PLEN + (s_axis_tdata(47 downto 32) /= X"0100") or --OPER + (s_axis_tlast = '1') then + pkt_nonmatch := true; + end if; + when 3 => + sender_hw_addr_be(47 downto 16) <= s_axis_tdata(31 downto 0); + sender_protocol_addr_be <= s_axis_tdata(63 downto 32); + if (s_axis_tlast = '1') then + pkt_nonmatch := true; + end if; + when 4 => + --THA = s_axis_tdata(47 downto 0) + target_protocol_addr_be(15 downto 0) <= s_axis_tdata(63 downto 48); + if (s_axis_tdata(63 downto 48) /= ip_addr_be(15 downto 0)) or + (s_axis_tlast = '1') then + pkt_nonmatch := true; + end if; + when 5 => + target_protocol_addr_be(31 downto 16) <= s_axis_tdata(15 downto 0); + if (s_axis_tdata(15 downto 0) /= ip_addr_be(31 downto 16)) then + pkt_nonmatch := true; + end if; + when others => + null; + end case; + end if; + if (pkt_nonmatch) then + if (s_axis_tlast = '1') then + pkt_state <= PKT_IDLE; + else + pkt_state <= PKT_DROP; + end if; + elsif (s_axis_tlast = '1') then + pkt_state <= PKT_SEND; + end if; + when PKT_SEND => + if (m_axis_tready = '1') then + pkt_send_count <= pkt_send_count + 1; + + if (pkt_send_count = 5) then + pkt_state <= PKT_IDLE; + end if; + end if; + when PKT_DROP => + if (s_axis_tvalid = '1') and (s_axis_tlast = '1') then + pkt_state <= PKT_IDLE; + end if; + end case; + + if aresetn = '0' then + pkt_state <= PKT_IDLE; + end if; + end if; + end process; +end arch; + |