http2: Deal with HTTP/2 data inside response header buffer

Previously if HTTP/2 traffic is appended to HTTP Upgrade response header
(thus they are in the same buffer), the trailing HTTP/2 traffic is not
processed and lost.  The appended data is most likely SETTINGS frame.
If it is lost, nghttp2 library complains server does not obey the HTTP/2
protocol and issues GOAWAY frame and curl eventually drops connection.
This commit fixes this problem and now trailing data is processed.

lib/http.c

@@ -1746,7 +1746,7 @@ CURLcode Curl_http(struct connectdata *conn, bool *done)
       if(result)
         return result;
 
-      result = Curl_http2_switched(conn);
+      result = Curl_http2_switched(conn, NULL, 0);
       if(result)
         return result;
       break;
@@ -2993,10 +2993,12 @@ CURLcode Curl_http_readwrite_headers(struct SessionHandle *data,
             infof(data, "Received 101\n");
             k->upgr101 = UPGR101_RECEIVED;
 
-            /* switch to http2 now */
-            result = Curl_http2_switched(conn);
+            /* switch to http2 now. The bytes after response headers
+               are also processed here, otherwise they are lost. */
+            result = Curl_http2_switched(conn, k->str, *nread);
             if(result)
               return result;
+            *nread = 0;
           }
           break;
         default:

lib/http2.c

@@ -988,7 +988,8 @@ CURLcode Curl_http2_setup(struct connectdata *conn)
   return 0;
 }
 
-CURLcode Curl_http2_switched(struct connectdata *conn)
+CURLcode Curl_http2_switched(struct connectdata *conn,
+                             const char *mem, size_t nread)
 {
   CURLcode rc;
   struct http_conn *httpc = &conn->proto.httpc;
@@ -1036,6 +1037,15 @@ CURLcode Curl_http2_switched(struct connectdata *conn)
       return CURLE_HTTP2;
     }
   }
+
+  rv = (int)nghttp2_session_mem_recv(httpc->h2, (const uint8_t*)mem, nread);
+
+  if(rv != (int)nread) {
+    failf(data, "nghttp2_session_mem_recv() failed: %s(%d)",
+          nghttp2_strerror(rv), rv);
+    return CURLE_HTTP2;
+  }
+
   return CURLE_OK;
 }
 

lib/http2.h

@@ -37,7 +37,8 @@ CURLcode Curl_http2_send_request(struct connectdata *conn);
 CURLcode Curl_http2_request_upgrade(Curl_send_buffer *req,
                                     struct connectdata *conn);
 CURLcode Curl_http2_setup(struct connectdata *conn);
-CURLcode Curl_http2_switched(struct connectdata *conn);
+CURLcode Curl_http2_switched(struct connectdata *conn,
+                             const char *data, size_t nread);
 #else /* USE_NGHTTP2 */
 #define Curl_http2_init(x) CURLE_UNSUPPORTED_PROTOCOL
 #define Curl_http2_send_request(x) CURLE_UNSUPPORTED_PROTOCOL