From 1f214f4158d2bd1a06f09cfbd4b017c0aceb2229 Mon Sep 17 00:00:00 2001
From: Oskar Eichler <62393985+OskarEichler@users.noreply.github.com>
Date: Fri, 4 Sep 2026 22:52:07 +0700
Subject: [PATCH] Control API: log errors from accepted socket setup

Accepted control connections discarded errno when setting close-on-exec,
nonblocking I/O, or signal ownership. The error log identified the failed
fcntl() operation but omitted the operating system reason.

Pass ngx_socket_errno to the three error logs, consistently with listener
setup and inherited socket handling.
---
 src/os/unix/ngx_control.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/os/unix/ngx_control.c b/src/os/unix/ngx_control.c
index 08b2d0195..f191f00dd 100644
--- a/src/os/unix/ngx_control.c
+++ b/src/os/unix/ngx_control.c
@@ -493,21 +493,21 @@ ngx_control_handle_accept(void)
                        "control accept fd:%d", r->fd);
 
         if (fcntl(r->fd, F_SETFD, FD_CLOEXEC) == -1) {
-            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, 0,
+            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, ngx_socket_errno,
                           "control: fcntl(FD_CLOEXEC) failed");
             ngx_close_socket(r->fd);
             continue;
         }
 
         if (fcntl(r->fd, F_SETFL, O_ASYNC|O_NONBLOCK) == -1) {
-            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, 0,
+            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, ngx_socket_errno,
                           "control: fcntl(O_ASYNC|O_NONBLOCK) failed");
             ngx_close_socket(r->fd);
             continue;
         }
 
         if (fcntl(r->fd, F_SETOWN, ngx_pid) == -1) {
-            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, 0,
+            ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, ngx_socket_errno,
                           "control: fcntl(F_SETOWN) failed");
             ngx_close_socket(r->fd);
             continue;
-- 
2.47.3