| 290,20 → 290,18 |
|---|
| ; No, it's just a regular IP packet, pass it to the higher protocols |
| |
| .handle_it: ; We reach here if packet hasnt been fragmented, or when it already has been re-constructed |
| movzx eax, [edx + IPv4_header.VersionAndIHL] ; Calculate Header length by using IHL field |
| and eax, 0x0000000f ; |
| shl eax, 2 ; |
| |
| movzx esi, [edx + IPv4_header.VersionAndIHL] ; Calculate Header length by using IHL field |
| and esi, 0x0000000f ; |
| shl esi, 2 ; |
| |
| movzx ecx, [edx + IPv4_header.TotalLength] ; Calculate length of encapsulated Packet |
| xchg cl , ch ; |
| sub ecx, eax ; |
| sub ecx, esi ; |
| |
| add eax, edx |
| push eax |
| |
| mov esi, [edx + IPv4_header.SourceAddress] ; These values might be of interest to the higher protocols |
| mov edi, [edx + IPv4_header.DestinationAddress] ; |
| lea edi, [edx + IPv4_header.SourceAddress] ; make edi ptr to source and dest IPv4 address |
| mov al , [edx + IPv4_header.Protocol] |
| pop edx ; Offset to data (tcp/udp/icmp/.. Packet) |
| add edx, esi ; make edi ptr to data |
| |
| cmp al , IP_PROTO_TCP |
| je TCP_input |