HTTP/3: postponed session creation to init() callback.

Now the session object is assigned to c->data while ngx_http_connection_t
object is referenced by its http_connection field, similar to
ngx_http_v2_connection_t and ngx_http_request_t.

The change allows to eliminate v3_session field from ngx_http_connection_t.
The field was under NGX_HTTP_V3 macro, which was a source of binary
compatibility problems when nginx/module is build with/without HTTP/3 support.

Postponing is essential since c->data should retain the reference to
ngx_http_connection_t object throughout QUIC handshake, because SSL callbacks
ngx_http_ssl_servername() and ngx_http_ssl_alpn_select() rely on this.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/http/v3/ngx_http_v3_request.c b/src/http/v3/ngx_http_v3_request.c
index 92c204c24..87f5f3214 100644
--- a/src/http/v3/ngx_http_v3_request.c
+++ b/src/http/v3/ngx_http_v3_request.c
@@ -69,11 +69,6 @@ ngx_http_v3_init_stream(ngx_connection_t *c)
     clcf = ngx_http_get_module_loc_conf(hc->conf_ctx, ngx_http_core_module);
 
     if (c->quic == NULL) {
-        if (ngx_http_v3_init_session(c) != NGX_OK) {
-            ngx_http_close_connection(c);
-            return;
-        }
-
         h3scf = ngx_http_get_module_srv_conf(hc->conf_ctx, ngx_http_v3_module);
         h3scf->quic.idle_timeout = clcf->keepalive_timeout;
 
@@ -113,6 +108,10 @@ ngx_http_v3_init(ngx_connection_t *c)
 
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http3 init");
 
+    if (ngx_http_v3_init_session(c) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
     h3c = ngx_http_v3_get_session(c);
     clcf = ngx_http_v3_get_module_loc_conf(c, ngx_http_core_module);
     ngx_add_timer(&h3c->keepalive, clcf->keepalive_timeout);