From: op <op@openbsd.org>
Date: Thu, 11 Aug 2022 14:25:22 +0000 (+0000)
Subject: correctly handle an abnormal fastcgi termination.  httpd handles the
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=193f358a192419466a04766a993921703e965df7;p=openbsd

correctly handle an abnormal fastcgi termination.  httpd handles the
disconnection from the fastcgi application via server_file_error which
assumes that the reply was completey done.  However, if the fastcgi
reply wasn't complete (e.g. because slowcgi hit the timeout) the HTTP
client are left "hanging" and waiting for a reply until they give up.

This adds a server_fcgi_error callback to handle the "no headers" and
"incomplete data" cases and properly close the reply before falling back
to server_file_error.

OK claudio@
---

diff --git a/usr.sbin/httpd/server_fcgi.c b/usr.sbin/httpd/server_fcgi.c
index 381fade2924..c0f6ed505c9 100644
--- a/usr.sbin/httpd/server_fcgi.c
+++ b/usr.sbin/httpd/server_fcgi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: server_fcgi.c,v 1.90 2022/03/02 11:10:43 florian Exp $	*/
+/*	$OpenBSD: server_fcgi.c,v 1.91 2022/08/11 14:25:22 op Exp $	*/
 
 /*
  * Copyright (c) 2014 Florian Obser <florian@openbsd.org>
@@ -77,6 +77,7 @@ struct server_fcgi_param {
 };
 
 int	server_fcgi_header(struct client *, unsigned int);
+void	server_fcgi_error(struct bufferevent *, short, void *);
 void	server_fcgi_read(struct bufferevent *, void *);
 int	server_fcgi_writeheader(struct client *, struct kv *, void *);
 int	server_fcgi_writechunk(struct client *);
@@ -133,7 +134,7 @@ server_fcgi(struct httpd *env, struct client *clt)
 
 	clt->clt_srvbev_throttled = 0;
 	clt->clt_srvbev = bufferevent_new(fd, server_fcgi_read,
-	    NULL, server_file_error, clt);
+	    NULL, server_fcgi_error, clt);
 	if (clt->clt_srvbev == NULL) {
 		errstr = "failed to allocate fcgi buffer event";
 		goto fail;
@@ -481,6 +482,23 @@ fcgi_add_param(struct server_fcgi_param *p, const char *key,
 	return (0);
 }
 
+void
+server_fcgi_error(struct bufferevent *bev, short error, void *arg)
+{
+	struct client		*clt = arg;
+
+	if ((error & EVBUFFER_EOF) && !clt->clt_fcgi.headersdone) {
+		server_abort_http(clt, 500, "malformed or no headers");
+		return;
+	}
+
+	/* send the end marker if not already */
+	if (clt->clt_fcgi.chunked && !clt->clt_fcgi.end++)
+		server_bufferevent_print(clt, "0\r\n\r\n");
+
+	server_file_error(bev, error, arg);
+}
+
 void
 server_fcgi_read(struct bufferevent *bev, void *arg)
 {