Copy rapid reset parameters to the h2 session

Ref #3996

Author: nigoroll

bin/varnishd/http2/cache_http2.h

@@ -193,6 +193,13 @@ struct h2_sess {
 	VTAILQ_HEAD(,h2_req)		txqueue;
 
 	h2_error			error;
+
+	// rst rate limit parameters, copied from h2_* parameters
+	vtim_dur			rapid_reset;
+	int64_t				rapid_reset_limit;
+	vtim_dur			rapid_reset_period;
+
+	// rst rate limit state
 	double				rst_budget;
 	vtim_real			last_rst;
 };

bin/varnishd/http2/cache_http2_proto.c

@@ -337,20 +337,20 @@ h2_rx_rst_stream(struct worker *wrk, struct h2_sess *h2, struct h2_req *r2)
 		return (0);
 	h2_kill_req(wrk, h2, r2, h2_streamerror(vbe32dec(h2->rxf_data)));
 
-	if (cache_param->h2_rapid_reset_limit == 0)
+	if (h2->rapid_reset_limit == 0)
 		return (0);
 
 	now = VTIM_real();
 	CHECK_OBJ_NOTNULL(r2->req, REQ_MAGIC);
 	AN(r2->req->t_first);
-	if (now - r2->req->t_first > cache_param->h2_rapid_reset)
+	if (now - r2->req->t_first > h2->rapid_reset)
 		return (0);
 
 	d = now - h2->last_rst;
-	h2->rst_budget += cache_param->h2_rapid_reset_limit * d /
-	    cache_param->h2_rapid_reset_period;
+	h2->rst_budget += h2->rapid_reset_limit * d /
+	    h2->rapid_reset_period;
 	h2->rst_budget = vmin_t(double, h2->rst_budget,
-	    cache_param->h2_rapid_reset_limit);
+	    h2->rapid_reset_limit);
 	h2->last_rst = now;
 
 	if (h2->rst_budget < 1.0) {

bin/varnishd/http2/cache_http2_session.c

@@ -127,7 +127,12 @@ h2_init_sess(struct sess *sp,
 	h2_local_settings(&h2->local_settings);
 	h2->remote_settings = H2_proto_settings;
 	h2->decode = decode;
-	h2->rst_budget = cache_param->h2_rapid_reset_limit;
+
+	h2->rapid_reset = cache_param->h2_rapid_reset;
+	h2->rapid_reset_limit = cache_param->h2_rapid_reset_limit;
+	h2->rapid_reset_period = cache_param->h2_rapid_reset_period;
+
+	h2->rst_budget = h2->rapid_reset_limit;
 	h2->last_rst = sp->t_open;
 	AZ(isnan(h2->last_rst));