MINOR: tcp_act: remove limitation on protocol for attach-srv

This patch allows to specify "tcp-request session attach-srv" without
requiring that each associated bind lines mandates HTTP/2 usage. If a
non supported protocol is targetted by this rule, conn_install_mux_fe()
is responsible to reject it.

This change is mandatory to be able to mix attach-srv and standard
non-reversable connection on the same bind instances. An ACL can be used
to activate attach-srv only on some conditions.

src/tcp_act.c

@@ -427,7 +427,6 @@ static int tcp_check_attach_srv(struct act_rule *rule, struct proxy *px, char **
 {
 	struct proxy *be = NULL;
 	struct server *srv = NULL;
-	struct bind_conf *bind_conf;
 	char *name = rule->arg.attach_srv.srvname;
 	struct ist be_name, sv_name;
 
@@ -436,18 +435,6 @@ static int tcp_check_attach_srv(struct act_rule *rule, struct proxy *px, char **
 		return 0;
 	}
 
-	list_for_each_entry(bind_conf, &px->conf.bind, by_fe) {
-		if ((bind_conf->mux_proto && !isteqi(bind_conf->mux_proto->token, ist("h2")))
-#ifdef USE_OPENSSL
-		    || (bind_conf->ssl_conf.alpn_str && strcmp(bind_conf->ssl_conf.alpn_str, "\x02h2") != 0)
-#endif
-		) {
-			memprintf(err, "attach-srv rule: incompatible with listener on %s:%d which uses protocol other than HTTP/2",
-			          bind_conf->file, bind_conf->line);
-			return 0;
-		}
-	}
-
 	sv_name = ist(name);
 	be_name = istsplit(&sv_name, '/');
 	if (!istlen(sv_name)) {
@@ -464,16 +451,6 @@ static int tcp_check_attach_srv(struct act_rule *rule, struct proxy *px, char **
 		return 0;
 	}
 
-	if ((srv->mux_proto && !isteqi(srv->mux_proto->token, ist("h2")))
-#ifdef USE_OPENSSL
-		    || (srv->ssl_ctx.alpn_str && strcmp(srv->ssl_ctx.alpn_str, "\x02h2") != 0)
-#endif
-	) {
-		memprintf(err, "attach-srv rule: incompatible with server '%s:%s' which uses protocol other than HTTP/2",
-		          ist0(be_name), ist0(sv_name));
-		return 0;
-	}
-
 	if ((rule->arg.attach_srv.name && (!srv->use_ssl || !srv->sni_expr)) ||
 	    (!rule->arg.attach_srv.name && srv->use_ssl && srv->sni_expr)) {
 		memprintf(err, "attach-srv rule: connection will never be used; either specify name argument in conjonction with defined SSL SNI on targetted server or none of these");