From e3ab67013e6e086a3b871a50e9a14ae5937c3b4e Mon Sep 17 00:00:00 2001
From: root <>
Date: Sun, 4 May 2025 14:42:56 +0000
Subject: [PATCH] bind to unix socket

---
 hello.s   | 84 +++++++++++++++++++++++++++++++++++++++++++++----------
 readme.md |  2 ++
 2 files changed, 72 insertions(+), 14 deletions(-)

diff --git a/hello.s b/hello.s
index 35dd483..3d8622c 100644
--- a/hello.s
+++ b/hello.s
@@ -1,27 +1,83 @@
 global _start
 
 ; constants
-SYS_WRITE   equ 1
-SYS_EXIT    equ 60
-STDOUT      equ 1
+SYS_READ        equ 0
+SYS_WRITE       equ 1
+SYS_SENDFILE    equ 40
+SYS_SOCKET      equ 41
+SYS_ACCEPT      equ 43
+SYS_BIND        equ 49
+SYS_LISTEN      equ 50
+SYS_EXIT        equ 60
+STDOUT          equ 1
+AF_UNIX         equ 1
+SOCK_STREAM     equ 1
 
 SECTION .data
-hello           db  "Hello world!", 0x0a
+hello           db "Hello world!", 0x0a
 hello_len       equ $ - hello
+server_path     db "server.sock", 0x00
+server_path_len equ $ - hello
+sockaddr_len    equ 110 ; $ man 7 unix
+
+SECTION .bss
+sockaddr    resb sockaddr_len
 
 SECTION .text
 
 _start:
-    ; syscall(SYS_WRITE, STDOUT, hello, hello_len);
-    mov     rax, SYS_WRITE
-    mov     rdi, STDOUT
-    mov     rsi, hello
-    mov     rdx, hello_len
+    mov rax, SYS_WRITE
+    mov rdi, STDOUT
+    mov rsi, hello
+    mov rdx, hello_len
     syscall
-    push    rax
 
-    ; syscall(SYS_EXIT, <sys_write return value> - hello_len);
-    mov     rax, SYS_EXIT
-    pop     rdi
-    sub     rdi, hello_len
+make_server:
+    mov rax, SYS_SOCKET
+    mov rdi, AF_UNIX
+    mov rsi, SOCK_STREAM
+    mov rdx, 0
     syscall
+    push rax
+
+    call make_sockaddr
+    pop r10
+
+    mov rax, SYS_BIND
+    mov rdi, r10
+    mov rsi, sockaddr
+    mov rdx, sockaddr_len
+    syscall
+
+    mov rax, SYS_LISTEN
+    mov rdi, r10
+    mov rsi, 100
+    syscall
+
+    mov rax, SYS_ACCEPT
+    mov rdi, r10
+    mov rsi, 0
+    mov rdx, 0
+    syscall
+    push rax
+
+exit:
+    mov rax, SYS_EXIT
+    pop rdi
+    syscall
+
+make_sockaddr:
+    mov word [sockaddr], AF_UNIX
+    mov rax, 0
+
+make_sockaddr__copy_server_path:
+    cmp rax, server_path_len
+    jge return
+    mov r10, [rax+server_path]
+    add rax, 2
+    mov [rax+sockaddr], r10
+    sub rax, 1
+    jmp make_sockaddr__copy_server_path
+
+return:
+    ret
diff --git a/readme.md b/readme.md
index d88bd5c..64a06fc 100644
--- a/readme.md
+++ b/readme.md
@@ -6,3 +6,5 @@ https://x64.syscall.sh/
 https://web.stanford.edu/class/cs107/resources/x86-64-reference.pdf
 https://ggbaker.ca/295/x86.html
 https://josemariasola.github.io/reference/assembler/Stanford%20CS107%20Guide%20to%20x86-64.pdf
+
+https://www.bencode.net/blob/nasmcheatsheet.pdf