global _start

; constants
SYS_WRITE       equ 1
SYS_SOCKET      equ 41
SYS_CONNECT     equ 42
SYS_SHUTDOWN    equ 48
SYS_FCNTL       equ 72
SYS_EXIT        equ 60
AF_UNIX         equ 1
SOCK_STREAM     equ 1
F_GETFL         equ 3
F_SETFL         equ 4
O_NONBLOCK      equ 2048
SHUT_RDWR       equ 2

SECTION .data
server_path     db "eagain.sock", 0x00
server_path_len equ $ - server_path
sockaddr_size   equ 2 + 108  ; $ man 7 unix

SECTION .bss
sockaddr        resb sockaddr_size
spam            resb 0xffff

SECTION .text

_start:
    mov rax, SYS_SOCKET
    mov rdi, AF_UNIX
    mov rsi, SOCK_STREAM
    mov rdx, 0
    syscall

    mov r15, rax

    call nonblocking
    call make_sockaddr

    mov rax, SYS_CONNECT
    mov rdi, r15
    mov rsi, sockaddr
    mov rdx, sockaddr_size
    syscall

loop:
    mov rax, SYS_WRITE
    mov rdi, r15
    mov rsi, spam
    mov rdx, 0xffff
    syscall

    cmp rax, 0
    jge loop

    mov rax, SYS_EXIT
    mov rdi, 1
    syscall

nonblocking:
    mov r10, rax

    mov rax, SYS_FCNTL
    mov rdi, r10
    mov rsi, F_GETFL
    syscall

    mov r11, rax
    xor r11, O_NONBLOCK

    mov rax, SYS_FCNTL
    mov rdi, r10
    mov rsi, F_SETFL
    mov rdx, r11
    syscall

    ret

make_sockaddr:
    mov word [sockaddr], AF_UNIX
    mov rax, 0

make_sockaddr__copy_server_path:
    cmp rax, server_path_len
    jge return
    mov r10, [server_path + rax]
    mov [sockaddr + rax + 2], r10
    add rax, 8
    jmp make_sockaddr__copy_server_path

return:
    ret