main:
push fp
mov fp, sp
sub sp, 0x1000
mov r3, 0
mov r2, 1
mov r1, 2
mov r0, 5
syscall
mov r6, r0 ; fd = socket(2,1,0);
mov r1, r6
mov r0, 7
mov r2, 0x200d ; &server_addr
mov r3, 16
syscall ; bind
mov r0, 8
mov r1, r6
mov r2, 20
syscall ; listen
_infinite_loop:
mov r0, 6
mov r1, r6
mov r2, 0
mov r3, 0
syscall ; accept
mov r7, r0
mov r0, 9
syscall ; fork
cmp r0, 0
je _child
jne _parent
_child:
mov r0, 2
mov r1, r6
syscall
call handle
mov r0, 2
mov r1, r7
mov r0, 0
mov r1, 0
syscall
_parent:
mov r0, 2
mov r1, r7
syscall
jmp _infinite_loop
mov sp, fp
pop fp
ret

memset:
push fp
mov fp, sp
push r0
push r1
push r2
mov r0, fp
mov r1, r0
mov r2, r0
add r0, 8
add r1, 0xc
add r2, 0x10
mov r0, (r0)
mov r1, (r1)
mov r2, (r2)
_memset_loop:
mov (r0), r1
sub r2, 1
cmp r2, 0
jne _memset_loop
pop r2
pop r1
pop r0
pop fp
ret


handle:
push fp
mov fp, sp
sub sp, 0x100
mov r0, fp
sub r0, 8
mov (r0), canary
call greet
mov r0, 3
mov r1, r7
mov r2, fp
sub r2, 0x100
mov r3, 4096
syscall
mov r0, 4
mov r1, r7
mov r2, fp
sub r2, 0x100
mov r3, 4096
syscall
mov r0, fp
sub r0, 8
mov r0, (r0)
xor r0, canary
cmp r0, 0
mov sp, fp
je _good
mov r0, 0
syscall
_good:
pop fp
ret


greet:
push fp
mov fp, sp
push r0
push r1
push r2
push r3
push r4
sub sp, 0x90c
mov r1, fp
sub r1, 0x904
mov r5, r1
push 0x8f8
push 0
push r1
call memset
add sp, 12
mov r0, 1
mov r1, 0x2000
mov r2, 0
syscall
mov r4, r0
mov r1, r0
mov r0, 3
mov r2, r5
mov r3, 2296
syscall
mov r0, 2
syscall
mov r1, r7
mov r2, r5
mov r3, 2296
mov r0, 4
syscall
mov r0, 4
mov r1, r7
mov r2, 0x201d ;will you escape from this virtual reality
mov r3, 43
syscall
mov r0, 4
mov r2, 0x2048; or will you control this world
mov r3, 32
syscall
mov r0, 4
mov r2, 0x2068 ; choice is yours. good luck
mov r3, 28
syscall
mov r0, 4
mov r2, 0x2084 ; choice>
mov r3, 8
syscall
add sp, 0x90c
pop r4
pop r3
pop r2
pop r1
pop r0
pop fp
ret