[master] 95e41dfa5 If the client sends NO_RFC7540_PRIORITIES, "rxprio" verbs become no-ops.

[Poul-Henning Kamp]

commit 95e41dfa584d108e444949534c7ce5801cffeacc
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Wed Mar 26 09:25:43 2025 +0000

    If the client sends NO_RFC7540_PRIORITIES, "rxprio" verbs become no-ops.
    
    Fixes: #4298
    Tested by: @ingvarha

diff --git a/bin/varnishtest/vtc.h b/bin/varnishtest/vtc.h
index 2e5d4161a..b765fe60a 100644
--- a/bin/varnishtest/vtc.h
+++ b/bin/varnishtest/vtc.h
@@ -148,7 +148,7 @@ struct http;
 void cmd_stream(CMD_ARGS);
 void start_h2(struct http *hp);
 void stop_h2(struct http *hp);
-void b64_settings(const struct http *hp, const char *s);
+void b64_settings(struct http *hp, const char *s);
 
 /* vtc_gzip.c */
 void vtc_gunzip(struct http *, char *, long *);
diff --git a/bin/varnishtest/vtc_http.h b/bin/varnishtest/vtc_http.h
index 7a86de8da..62c598a55 100644
--- a/bin/varnishtest/vtc_http.h
+++ b/bin/varnishtest/vtc_http.h
@@ -83,6 +83,7 @@ struct http {
 	/* H/2 */
 	unsigned		h2;
 	int			wf;
+	int			no_rfc7540_priorities;
 
 	pthread_t		tp;
 	VTAILQ_HEAD(, stream)   streams;
diff --git a/bin/varnishtest/vtc_http2.c b/bin/varnishtest/vtc_http2.c
index 822abbae1..7feeb42b0 100644
--- a/bin/varnishtest/vtc_http2.c
+++ b/bin/varnishtest/vtc_http2.c
@@ -629,7 +629,7 @@ parse_settings(const struct stream *s, struct frame *f)
 			buf = "unknown";
 		u += 4;
 
-		if (t == 1) {
+		if (t == SETTINGS_HEADER_TABLE_SIZE) {
 			r = HPK_ResizeTbl(s->hp->encctx, v);
 			assert(r == hpk_done);
 		}
@@ -2460,28 +2460,47 @@ cmd_rxsettings(CMD_ARGS)
 		hp->h2_win_peer->init = val;
 	}
 }
+/* SECTION: stream.spec.prio_rxprio rxprio
+ *
+ * Receive a PRIORITY frame.
+ */
+static void
+cmd_rxprio (CMD_ARGS)
+{
+	struct stream *s;
+	(void)av;
+	CAST_OBJ_NOTNULL(s, priv, STREAM_MAGIC);
+        if (s->hp->no_rfc7540_priorities) {
+		vtc_log(vl, 4, "skipping rxprio: no_rfc7540_priorities is set");
+		return;
+	}
+	s->frame = rxstuff(s);
+	if (s->frame != NULL && s->frame->type != TYPE_PRIORITY) {
+		vtc_fatal(vl,
+		    "Wrong frame type %s (%d) wanted %s",
+		    s->frame->type < TYPE_MAX ?
+		    h2_types[s->frame->type] : "?",
+		    s->frame->type, "PRIORITY");
+	}
+}
 
 #define RXFUNC(lctype, upctype) \
 	static void \
-	cmd_rx ## lctype(CMD_ARGS) { \
+	cmd_rx ## lctype(CMD_ARGS) \
+	{ \
 		struct stream *s; \
 		(void)av; \
 		CAST_OBJ_NOTNULL(s, priv, STREAM_MAGIC); \
 		s->frame = rxstuff(s); \
-		if (s->frame != NULL && s->frame->type != TYPE_ ## upctype) \
+		if (s->frame != NULL && s->frame->type != TYPE_ ## upctype) { \
 			vtc_fatal(vl, \
 			    "Wrong frame type %s (%d) wanted %s", \
 			    s->frame->type < TYPE_MAX ? \
 			    h2_types[s->frame->type] : "?", \
 			    s->frame->type, #upctype); \
+		} \
 	}
 
-/* SECTION: stream.spec.prio_rxprio rxprio
- *
- * Receive a PRIORITY frame.
- */
-RXFUNC(prio,	PRIORITY)
-
 /* SECTION: stream.spec.reset_rxrst rxrst
  *
  * Receive a RST_STREAM frame.
@@ -2857,7 +2876,7 @@ cmd_stream(CMD_ARGS)
 }
 
 void
-b64_settings(const struct http *hp, const char *s)
+b64_settings(struct http *hp, const char *s)
 {
 	uint16_t i;
 	uint64_t v, vv;
@@ -2891,7 +2910,10 @@ b64_settings(const struct http *hp, const char *s)
 		else
 			buf = "unknown";
 
-		if (v == 1) {
+		if (i == SETTINGS_NO_RFC7540_PRIORITIES) {
+			hp->no_rfc7540_priorities = v;
+		}
+		if (i == SETTINGS_HEADER_TABLE_SIZE) {
 			enum hpk_result hrs;
 			if (hp->sfd) {
 				AN(hp->encctx);