Negative Defense Bug

[fretelo]

Defense is not displayed properly when your defense is negative. This character is using "Easter Eggshell" Which reduces my medf and def.

My actual stats are:
-1 +13 Def
-6 +3 MDef


Screen shot of error:

[Technology]

This is because for packet
00BD
stats_info
now we unpack def with unpack string v (unsigned short)
if we want the value to have a sign (+/-), we need to unpack with a signed short unpack string.

However doing this isn't as simple (as it should be imo) and i quote from http://perldoc.perl.org/functions/pack.html:

The integer formats s, S , i , I , l , L , j , and J are inherently
non-portable between processors and operating systems because they
obey native byteorder and endianness. For example, a 4-byte integer
0x12345678 (305419896 decimal) would be ordered natively
(arranged in and handled by the CPU registers) into bytes as:
0x12 0x34 0x56 0x78 # big-endian
0x78 0x56 0x34 0x12 # little-endian

Starting with Perl 5.9.2, integer and floating-point formats, along with
the p and P formats and () groups, may all be followed by the > or < endianness
modifiers to respectively enforce big- or little-endian byte-order.
These modifiers are especially useful given how n , N , v and V don't cover
signed integers, 64-bit integers, or floating-point values

So lets look at the actual struct:

Code: Select all

// packet 0xbd
struct PACKET_ZC_STATUS {
  /* this+0x0 */ short PacketType
  /* this+0x2 */ short point
  /* this+0x4 */ unsigned char str
  /* this+0x5 */ unsigned char standardStr
  /* this+0x6 */ unsigned char agi
  /* this+0x7 */ unsigned char standardAgi
  /* this+0x8 */ unsigned char vit
  /* this+0x9 */ unsigned char standardVit
  /* this+0xa */ unsigned char Int
  /* this+0xb */ unsigned char standardInt
  /* this+0xc */ unsigned char dex
  /* this+0xd */ unsigned char standardDex
  /* this+0xe */ unsigned char luk
  /* this+0xf */ unsigned char standardLuk
  /* this+0x10 */ short attPower
  /* this+0x12 */ short refiningPower
  /* this+0x14 */ short max_mattPower
  /* this+0x16 */ short min_mattPower
  /* this+0x18 */ short itemdefPower
  /* this+0x1a */ short plusdefPower
  /* this+0x1c */ short mdefPower
  /* this+0x1e */ short plusmdefPower
  /* this+0x20 */ short hitSuccessValue
  /* this+0x22 */ short avoidSuccessValue
  /* this+0x24 */ short plusAvoidSuccessValue
  /* this+0x26 */ short criticalSuccessValue
  /* this+0x28 */ short ASPD
  /* this+0x2a */ short plusASPD
}

from the perl pack page:

n An unsigned short (16-bit) in "network" (big-endian) order.
C An unsigned char (octet) value.
s A signed short (16-bit) value.

in C:
short = signed short

in perl:
s (and we want to force the little endian form so we add <)

Then we would end up with this unpack string:

Code: Select all

'00BD' => ['stats_info', 's< C12 s14<', [qw(points_free str points_str agi points_agi vit points_vit int points_int dex points_dex luk points_luk attack attack_bonus attack_magic_min attack_magic_max def def_bonus def_magic def_magic_bonus hit flee flee_bonus critical karma manner)]],

(ps: don't mind the struct, the names, etc, because they still need to be tested and might be incorrect, i just hope you get the general idea)

The types we use in current kore are guessed, but now we have the actual types and i'm working on a new (un)packer that uses the right types.
However its still work in progress as far as using the right types, because now i only support little endian machines.

[kLabMouse]

This needs of Validation in Each known packet (their original structs are known now).
Anybody willing?

P.S.:
unpack('V', $1) -> unsigned
unpack('!V', %1) -> signed