[nginx] SPDY: detect premature closing of stream.

[Valentin Bartenev]

details:   http://hg.nginx.org/nginx/rev/a24f88eff684
branches:  
changeset: 5628:a24f88eff684
user:      Valentin Bartenev <vbart at nginx.com>
date:      Fri Mar 28 20:22:57 2014 +0400
description:
SPDY: detect premature closing of stream.

The SPDY/3.1 specification requires that the server must respond with
a 400 "Bad request" error if the sum of the data frame payload lengths
does not equal the size of the Content-Length header.

This also fixes "zero size buf in output" alert, that might be triggered
if client sends a greater than zero Content-Length header and closes
stream using the FIN flag with an empty request body.

diffstat:

 src/http/ngx_http_spdy.c |  17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)

diffs (34 lines):

diff -r d74889fbf06d -r a24f88eff684 src/http/ngx_http_spdy.c
--- a/src/http/ngx_http_spdy.c	Fri Mar 28 20:05:07 2014 +0400
+++ b/src/http/ngx_http_spdy.c	Fri Mar 28 20:22:57 2014 +0400
@@ -1609,6 +1609,19 @@ ngx_http_spdy_state_read_data(ngx_http_s
 
         stream->in_closed = 1;
 
+        if (r->headers_in.content_length_n < 0) {
+            r->headers_in.content_length_n = rb->rest;
+
+        } else if (r->headers_in.content_length_n != rb->rest) {
+            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                          "client prematurely closed stream: "
+                          "%O of %O bytes of request body received",
+                          rb->rest, r->headers_in.content_length_n);
+
+            stream->skip_data = NGX_SPDY_DATA_ERROR;
+            goto error;
+        }
+
         if (tf) {
             ngx_memzero(buf, sizeof(ngx_buf_t));
 
@@ -1619,10 +1632,6 @@ ngx_http_spdy_state_read_data(ngx_http_s
             rb->buf = NULL;
         }
 
-        if (r->headers_in.content_length_n < 0) {
-            r->headers_in.content_length_n = rb->rest;
-        }
-
         if (rb->post_handler) {
             r->read_event_handler = ngx_http_block_reading;
             rb->post_handler(r);