From f096cb00e7913173d9645d4424751fd6a8a58ba1 Mon Sep 17 00:00:00 2001
From: root <>
Date: Wed, 7 May 2025 14:20:06 +0000
Subject: [PATCH] say goodbye to clients then close socket

---
 constants.c                       |  1 +
 main.s                            | 44 ++++++++++++++++++++++++++-----
 poll_remove.s => pollfds_remove.s | 27 ++++++++++---------
 3 files changed, 53 insertions(+), 19 deletions(-)
 rename poll_remove.s => pollfds_remove.s (60%)

diff --git a/constants.c b/constants.c
index cc8ec0b..2e7aab3 100644
--- a/constants.c
+++ b/constants.c
@@ -14,4 +14,5 @@ void main() {
     printf("sizeof(short)   %d\n", sizeof(short));
     printf("POLLIN          %d\n", POLLIN);
     printf("POLLOUT         %d\n", POLLOUT);
+    printf("SHUT_RDWR       %d\n", SHUT_RDWR);
 }
diff --git a/main.s b/main.s
index 974f397..5b13b5d 100644
--- a/main.s
+++ b/main.s
@@ -3,10 +3,12 @@ global _start
 ; constants
 SYS_READ        equ 0
 SYS_WRITE       equ 1
+SYS_CLOSE       equ 3
 SYS_POLL        equ 7
 SYS_SENDFILE    equ 40
 SYS_SOCKET      equ 41
 SYS_ACCEPT      equ 43
+SYS_SHUTDOWN    equ 48
 SYS_BIND        equ 49
 SYS_LISTEN      equ 50
 SYS_EXIT        equ 60
@@ -20,6 +22,7 @@ F_SETFL         equ 4
 O_NONBLOCK      equ 2048
 POLLIN          equ 1
 POLLOUT         equ 4
+SHUT_RDWR       equ 2
 
 pollfd_size equ 4 + 2 + 2  ; $ man 2 poll
 pollfds_capacity equ 100
@@ -28,6 +31,8 @@ SECTION .data
 server_path     db "server.sock", 0x00
 server_path_len equ $ - server_path
 sockaddr_size   equ 2 + 108  ; $ man 7 unix
+goodbye         db "goodbye", 0x0a
+goodbye_len     equ $ - goodbye
 
 SECTION .bss
 sockaddr        resb sockaddr_size
@@ -36,8 +41,11 @@ pollfds_len     resb 8
 
 SECTION .text
 
+return:
+    ret
+
 %include "server.s"
-;%include "pollfds_remove.s"
+%include "pollfds_remove.s"
 
 _start:
     call make_server
@@ -71,17 +79,44 @@ pollfds__scan__loop:
     jmp pollfds__scan__loop
 
 pollfds__scan__found:
+    mov r14, 0
     mov r14d, [pollfds + r15 * pollfd_size]
     cmp r14d, edi
     je pollfds__scan__found__server
 
 pollfds__scan__found__client:
-    jmp exit
+    push rdi
+
+    mov rax, SYS_WRITE
+    mov rdi, 0
+    mov edi, r14d
+    mov rsi, goodbye
+    mov rdx, goodbye_len
+    syscall
+    cmp rax, 0
+    jl exit
+
+    mov rax, SYS_SHUTDOWN
+    mov rdi, 0
+    mov edi, r14d
+    mov rsi, SHUT_RDWR
+    syscall
+
+    mov rax, SYS_CLOSE
+    mov rdi, 0
+    mov edi, r14d
+    syscall
+
+    mov rdi, r14
+    call pollfds__remove
+
+    pop rdi
     jmp pollfds__scan__loop
 
 pollfds__scan__found__server:
-    mov rax, SYS_ACCEPT
     push rdi
+
+    mov rax, SYS_ACCEPT
     mov rsi, 0
     mov rdx, 0
     syscall
@@ -106,9 +141,6 @@ pollfds__append:
     mov [pollfds_len], r10
     ret
 
-return:
-    ret
-
 exit:
     mov rax, SYS_EXIT
     mov rdi, 0
diff --git a/poll_remove.s b/pollfds_remove.s
similarity index 60%
rename from poll_remove.s
rename to pollfds_remove.s
index 477dd81..9ccdc97 100644
--- a/poll_remove.s
+++ b/pollfds_remove.s
@@ -1,32 +1,33 @@
-; Returns new array length in rax
-; edi - fd
+; rdi - fd
 pollfds__remove:
-    mov r10d, edi
-    mov rdi, [pollfds_len]
+    mov rax, [pollfds_len]
+    mov rsi, 0
+    call pollfds__remove__loop
+    mov [pollfds_len], rax
+    ret
 
 ; Variables:
-; rdi - array length
+; rax - array length
+; rdi - fd
 ; rsi - array index
-; r10d - fd
 ; r11d - pollfds[rdi].fd
 pollfds__remove__loop:
-    cmp rsi, rdi
+    cmp rsi, rax
     jge return  ; fd was not found
     mov r11d, [pollfds + rsi * pollfd_size]
     add rsi, 1
-    cmp r11d, r10d
+    cmp r11d, edi
     jne pollfds__remove__loop
     sub rsi, 1
 
-; Returns new array length in rax
-; rdi - array length
+; rax - array length
 ; rsi - array index to remove
 pollfds__remove_index:
-    cmp rdi, 1
+    cmp rax, 1
     jle pollfds__clear
-    mov r10d, [pollfds + (rdi - 1) * pollfd_size]
+    mov r10d, [pollfds + (rax - 1) * pollfd_size]
     mov [pollfds + rsi * pollfd_size], r10d
-    sub rdi, 1
+    sub rax, 1
     ret
 
 ; Returns new array length in rax