common: add mac/arp/ip/udp header descriptions

diff --git a/liteeth/common.py b/liteeth/common.py
index 272f946cf3d45666f13135099ac10c76c8d63644..540747f4c26b9e29034f839670e2e97dfda08811 100644 (file)
--- a/liteeth/common.py
+++ b/liteeth/common.py
@@ -16,17 +16,101 @@ eth_mtu = 1532
 eth_preamble = 0xD555555555555555
 buffer_depth = 2**log2_int(eth_mtu, need_pow2=False)
 
+class HField():
+       def __init__(self, byte, offset, width):
+               self.byte = byte
+               self.offset = offset
+               self.width = width
+
+mac_header_len = 14
+mac_header = {
+       "destination_mac_address":      HField(0,  0, 48),
+       "source_mac_address":           HField(6,  0, 48),
+       "ethernet_type":                        HField(12, 0, 16)
+}
+
+arp_header_len = 28
+arp_header = {
+       "hardware_type":                        HField( 0,  0, 16),
+       "protocol_type":                        HField( 2,  0, 16),
+       "hardware_address_length":      HField( 4,  0, 8),
+       "protocol_address_length":      HField( 5,  0, 8),
+       "operation":                            HField( 6,  0, 16),
+       "source_mac_address":           HField( 8,  0, 48),
+       "source_ip_address":            HField(14,  0, 32),
+       "destination_mac_address":      HField(18,  0, 48),
+       "destination_ip_address":       HField(24,  0, 32)
+}
+
+ipv4_header_len = 24
+ipv4_header = {
+       "version":                                      HField(0,  0, 4),
+       "ihl":                                          HField(0,  4, 4),
+       "dscp":                                         HField(1,  0, 6),
+       "ecn":                                          HField(1,  6, 2),
+       "total_length":                         HField(2,  0, 16),
+       "identification":                       HField(4,  0, 16),
+       "flags":                                        HField(6,  0, 3),
+       "fragment_offset":                      HField(6,  3, 13),
+       "time_to_live":                         HField(8,  0, 8),
+       "protocol":                                     HField(9,  0, 8),
+       "header_checksum":                      HField(10,  0, 16),
+       "source_ip_address":            HField(12,  0, 32),
+       "destination_ip_address":       HField(16,  0, 32),
+       "options":                                      HField(20,  0, 32)
+}
+udp_header_len = 8
+udp_header = {
+       "source_port":                          HField( 0,  0, 16),
+       "destination_port":                     HField( 2,  0, 16),
+       "length":                                       HField( 4,  0, 16),
+       "checksum":                                     HField( 6,  0, 16)
+}
+
+# layouts
+def _layout_from_header(header):
+       _layout = []
+       for k, v in sorted(header.items()):
+               _layout.append((k, v.width))
+       return _layout
+
 def eth_phy_description(dw):
        layout = [
                ("data", dw),
+               ("last_be", dw//8),
                ("error", dw//8)
        ]
        return EndpointDescription(layout, packetized=True)
 
 def eth_mac_description(dw):
-       layout = [
+       layout = _layout_from_header(mac_header) + [
+               ("data", dw),
+               ("last_be", dw//8),
+               ("error", dw//8)
+       ]
+       return EndpointDescription(layout, packetized=True)
+
+def eth_arp_description(dw):
+       layout = _layout_from_header(arp_header) + [
                ("data", dw),
                ("last_be", dw//8),
                ("error", dw//8)
        ]
        return EndpointDescription(layout, packetized=True)
+
+def eth_ipv4_description(dw):
+       layout = _layout_from_header(ipv4_header) + [
+               ("data", dw),
+               ("last_be", dw//8),
+               ("error", dw//8)
+       ]
+       return EndpointDescription(layout, packetized=True)
+
+def eth_udp_description(dw):
+       layout = _layout_from_header(udp_header) + [
+               ("data", dw),
+               ("last_be", dw//8),
+               ("error", dw//8)
+       ]
+       return EndpointDescription(layout, packetized=True)
+