import struct, sys, io
sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
data = open('HAVOC_NOCD.EXE','rb').read()
FO2VA = lambda fo: fo + 0x400C00

def show(start, length):
    for row in range(start, start + length, 16):
        chunk = data[row:row+16]
        ann = []
        for j in range(len(chunk)):
            f = row + j
            try:
                if data[f] == 0xe8 and f+5 <= len(data):
                    rel = struct.unpack_from('<i', data, f+1)[0]
                    tgt = (FO2VA(f+5) + rel) & 0xFFFFFFFF
                    ann.append('+%d:CALL_0x%x' % (j, tgt))
                if data[f] == 0xff and data[f+1] == 0x15 and f+6 <= len(data):
                    iat = struct.unpack_from('<I', data, f+2)[0]
                    d = {
                        0x4822f4:'DirectDrawCreate', 0x4822fc:'DirectSoundCreate',
                        0x48240c:'ExitProcess', 0x48248c:'MessageBoxA',
                        0x4823cc:'LocalAlloc', 0x482370:'VirtualAlloc',
                        0x482390:'CreateFileA',
                    }
                    ann.append('+%d:[%s]' % (j, d.get(iat, 'iat_0x%x' % iat)))
                if data[f] == 0xc3: ann.append('+%d:RET' % j)
                if data[f] == 0xc2 and f+3 <= len(data):
                    n = struct.unpack_from('<H', data, f+1)[0]
                    ann.append('+%d:RET%d' % (j, n))
                if data[f] == 0xc7 and data[f+1] in (0x01,0x06,0x07) and f+6 <= len(data):
                    val = struct.unpack_from('<I', data, f+2)[0]
                    if 0x479000 <= val <= 0x47BFFF:
                        ann.append('+%d:VTABLE=0x%x' % (j, val))
            except Exception:
                pass
        line = 'FO 0x%05x VA 0x%07x: %s' % (row, FO2VA(row), ' '.join('%02x' % b for b in chunk))
        if ann:
            line += '  [%s]' % ','.join(ann)
        print(line)

print("=== context around caller FO 0x17A8A (pool allocator caller) ===")
show(0x17A60, 192)
print()
print("=== what's at FO 0x17A60 parent function start ===")
# find function start
fo = 0x17A60
while fo > 0 and data[fo-1] != 0xCC:
    fo -= 1
print("Function start: FO 0x%05x VA 0x%07x" % (fo, FO2VA(fo)))
show(fo, min(32, 0x17A60 - fo + 32))