changeset 7929:bfad703459b4

Stream: added half-close support. The "proxy_half_close" directive enables handling of TCP half close. If enabled, connection to proxied server is kept open until both read ends get EOF. Write end shutdown is properly transmitted via proxy.
author Vladimir Homutov <vl@nginx.com>
date Wed, 22 Sep 2021 10:20:00 +0300
parents 97cf8284fd19
children ae7c767aa491
files src/stream/ngx_stream_proxy_module.c src/stream/ngx_stream_upstream.h
diffstat 2 files changed, 37 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/src/stream/ngx_stream_proxy_module.c	Fri Sep 10 12:59:22 2021 +0300
+++ b/src/stream/ngx_stream_proxy_module.c	Wed Sep 22 10:20:00 2021 +0300
@@ -31,6 +31,7 @@
     ngx_uint_t                       next_upstream_tries;
     ngx_flag_t                       next_upstream;
     ngx_flag_t                       proxy_protocol;
+    ngx_flag_t                       half_close;
     ngx_stream_upstream_local_t     *local;
     ngx_flag_t                       socket_keepalive;
 
@@ -245,6 +246,13 @@
       offsetof(ngx_stream_proxy_srv_conf_t, proxy_protocol),
       NULL },
 
+    { ngx_string("proxy_half_close"),
+      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_STREAM_SRV_CONF_OFFSET,
+      offsetof(ngx_stream_proxy_srv_conf_t, half_close),
+      NULL },
+
 #if (NGX_STREAM_SSL)
 
     { ngx_string("proxy_ssl"),
@@ -1755,6 +1763,24 @@
     }
 
     if (dst) {
+
+        if (dst->type == SOCK_STREAM && pscf->half_close
+            && src->read->eof && !u->half_closed && !dst->buffered)
+        {
+            if (ngx_shutdown_socket(dst->fd, NGX_WRITE_SHUTDOWN) == -1) {
+                ngx_connection_error(c, ngx_socket_errno,
+                                     ngx_shutdown_socket_n " failed");
+
+                ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
+                return;
+            }
+
+            u->half_closed = 1;
+            ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
+                           "stream proxy %s socket shutdown",
+                           from_upstream ? "client" : "upstream");
+        }
+
         if (ngx_handle_write_event(dst->write, 0) != NGX_OK) {
             ngx_stream_proxy_finalize(s, NGX_STREAM_INTERNAL_SERVER_ERROR);
             return;
@@ -1833,6 +1859,13 @@
         return NGX_DECLINED;
     }
 
+    if (pscf->half_close) {
+        /* avoid closing live connections until both read ends get EOF */
+        if (!(c->read->eof && pc->read->eof && !c->buffered && !pc->buffered)) {
+             return NGX_DECLINED;
+        }
+    }
+
     handler = c->log->handler;
     c->log->handler = NULL;
 
@@ -2052,6 +2085,7 @@
     conf->proxy_protocol = NGX_CONF_UNSET;
     conf->local = NGX_CONF_UNSET_PTR;
     conf->socket_keepalive = NGX_CONF_UNSET;
+    conf->half_close = NGX_CONF_UNSET;
 
 #if (NGX_STREAM_SSL)
     conf->ssl_enable = NGX_CONF_UNSET;
@@ -2110,6 +2144,8 @@
     ngx_conf_merge_value(conf->socket_keepalive,
                               prev->socket_keepalive, 0);
 
+    ngx_conf_merge_value(conf->half_close, prev->half_close, 0);
+
 #if (NGX_STREAM_SSL)
 
     ngx_conf_merge_value(conf->ssl_enable, prev->ssl_enable, 0);
--- a/src/stream/ngx_stream_upstream.h	Fri Sep 10 12:59:22 2021 +0300
+++ b/src/stream/ngx_stream_upstream.h	Wed Sep 22 10:20:00 2021 +0300
@@ -142,6 +142,7 @@
     ngx_stream_upstream_state_t       *state;
     unsigned                           connected:1;
     unsigned                           proxy_protocol:1;
+    unsigned                           half_closed:1;
 } ngx_stream_upstream_t;