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

[Roman Arutyunyan]

Hi,

On Fri, Dec 15, 2023 at 07:37:47PM +0400, Sergey Kandaurov wrote:
> # 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) {

We should trigger an error if this option (TCP_DEFER_ACCEPT) is set for UDP.
We have a block "if (lsopt.type == SOCK_DGRAM) {}" later in this function.

--
Roman Arutyunyan