Assembly is cool

Author: Solyn

server.asm

@@ -0,0 +1,125 @@
+section .data
+    listen_sock     equ 3               ; File descriptor for listening socket
+    conn_sock       equ 4               ; File descriptor for connection socket
+    backlog         equ 5               ; Maximum length to which the queue of pending connections may grow
+    buf_size        equ 1024            ; Buffer size for receiving data
+
+    crlf            db 0x0D, 0x0A      ; Carriage return, Line feed
+    response        db 'HTTP/1.1 200 OK', crlf
+                    db 'Content-Type: text/plain', crlf
+                    db '', crlf
+                    db 'Hello, World!', crlf
+                    db 0               ; Null terminator
+
+section .bss
+    addr            resb 16            ; Buffer for storing remote address
+    buf             resb buf_size      ; Buffer for receiving data
+
+section .text
+    global _start
+
+_start:
+    ; Create a socket
+    mov eax, 102        ; sys_socketcall syscall number
+    mov ebx, 1          ; socketcall: SYS_SOCKET
+    mov ecx, 1          ; AF_INET: IPv4 protocol family
+    mov edx, 1          ; SOCK_STREAM: TCP socket type
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    mov dword [listen_sock], eax   ; Store the listening socket file descriptor
+
+    ; Bind the socket to an address and port
+    ; (Assuming binding to port 8080 and any available address)
+    mov eax, 102        ; sys_socketcall syscall number
+    mov ebx, 2          ; socketcall: SYS_BIND
+    mov ecx, dword [listen_sock]  ; Socket file descriptor
+    lea edx, [addr]     ; Pointer to the sockaddr_in structure
+    mov esi, 16         ; Size of the sockaddr_in structure
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    ; Listen for incoming connections
+    mov eax, 106        ; sys_socketcall syscall number
+    mov ebx, 4          ; socketcall: SYS_LISTEN
+    mov ecx, dword [listen_sock]  ; Socket file descriptor
+    mov edx, backlog    ; Maximum length to which the queue of pending connections may grow
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+accept_loop:
+    ; Accept incoming connections
+    mov eax, 102        ; sys_socketcall syscall number
+    mov ebx, 5          ; socketcall: SYS_ACCEPT
+    mov ecx, dword [listen_sock]  ; Socket file descriptor
+    lea edx, [addr]     ; Pointer to the sockaddr_in structure to store the remote address
+    lea esi, [conn_sock] ; Pointer to store the new connection socket file descriptor
+    mov edi, 16         ; Size of the sockaddr_in structure
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    ; Read data from the client
+    mov eax, 3          ; sys_read syscall number
+    mov ebx, dword [conn_sock]  ; Connection socket file descriptor
+    lea ecx, [buf]      ; Buffer to store received data
+    mov edx, buf_size   ; Maximum number of bytes to read
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    ; Send the response back to the client
+    mov eax, 4          ; sys_write syscall number
+    mov ebx, dword [conn_sock]  ; Connection socket file descriptor
+    lea ecx, [response] ; Response buffer
+    mov edx, response_len  ; Length of the response
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    ; Close the connection socket
+    mov eax, 6          ; sys_close syscall number
+    mov ebx, dword [conn_sock]  ; Connection socket file descriptor
+    int 0x80            ; call kernel
+
+    ; Check for errors
+    test eax, eax
+    js error_handling   ; Jump to error_handling if syscall returned with an error
+
+    ; Go back to accept more connections
+    jmp accept_loop
+
+error_handling:
+    ; Handle error
+    ; Print an error message or perform error recovery
+    jmp exit
+
+exit:
+    ; Close the listening socket
+    mov eax, 6          ; sys_close syscall number
+    mov ebx, dword [listen_sock]  ; Listening socket file descriptor
+    int 0x80            ; call kernel
+
+    ; Exit the program
+    mov eax, 1          ; sys_exit syscall number
+    xor ebx, ebx        ; Exit code 0
+    int 0x80            ; call kernel
+
+section .data
+    prompt_msg      db 'Enter your message: ', 0
+    prompt_len      equ $ - prompt_msg