[PATCH 4 of 6] Stream: the "deferred" parameter of the "listen" directive

[Sergey Kandaurov]

# HG changeset patch
# User Sergey Kandaurov <pluknet at nginx.com>
# Date 1702650289 -14400
#      Fri Dec 15 18:24:49 2023 +0400
# Node ID cca722e447f8beaaa6b41a620c8b4239a5d1aa7d
# Parent  4d90cb223fdb9e3e6c148726e36cec7835b2f0f8
Stream: the "deferred" parameter of the "listen" directive.

The Linux TCP_DEFER_ACCEPT support.

diff --git a/src/stream/ngx_stream.c b/src/stream/ngx_stream.c
--- a/src/stream/ngx_stream.c
+++ b/src/stream/ngx_stream.c
@@ -1021,6 +1021,10 @@ ngx_stream_add_listening(ngx_conf_t *cf,
     ls->keepcnt = addr->opt.tcp_keepcnt;
 #endif
 
+#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
+    ls->deferred_accept = addr->opt.deferred_accept;
+#endif
+
 #if (NGX_HAVE_INET6)
     ls->ipv6only = addr->opt.ipv6only;
 #endif
diff --git a/src/stream/ngx_stream.h b/src/stream/ngx_stream.h
--- a/src/stream/ngx_stream.h
+++ b/src/stream/ngx_stream.h
@@ -53,6 +53,7 @@ typedef struct {
 #if (NGX_HAVE_INET6)
     unsigned                       ipv6only:1;
 #endif
+    unsigned                       deferred_accept:1;
     unsigned                       reuseport:1;
     unsigned                       so_keepalive:2;
     unsigned                       proxy_protocol:1;
diff --git a/src/stream/ngx_stream_core_module.c b/src/stream/ngx_stream_core_module.c
--- a/src/stream/ngx_stream_core_module.c
+++ b/src/stream/ngx_stream_core_module.c
@@ -987,6 +987,19 @@ ngx_stream_core_listen(ngx_conf_t *cf, n
             continue;
         }
 
+        if (ngx_strcmp(value[i].data, "deferred") == 0) {
+#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
+            lsopt.deferred_accept = 1;
+            lsopt.set = 1;
+            lsopt.bind = 1;
+#else
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                               "the deferred accept is not supported "
+                               "on this platform, ignored");
+#endif
+            continue;
+        }
+
         if (ngx_strncmp(value[i].data, "ipv6only=o", 10) == 0) {
 #if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
             if (ngx_strcmp(&value[i].data[10], "n") == 0) {