From 9bc1c95855b9c6300de5ecf3720cbe4b2558c5a1 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Fri, 2 Aug 2019 07:48:47 +0200 Subject: [PATCH] BUG/MEDIUM: mux-h2: unbreak receipt of large DATA frames Recent optimization in commit 4d7a88482 ("MEDIUM: mux-h2: don't try to read more than needed") broke the receipt of large DATA frames because it would unconditionally subscribe if there was some room left, thus preventing any new rx from being done since subscription may only be done once the end was reached, as indicated by ret == 0. However, fixing this uncovered that in HTX mode previous versions might occasionally be affected as well, when an available frame is the same size as the maximum data that may fit into an HTX buffer, we may end up reading that whole frame and still subscribe since it's still allowed to receive, thus causing issues to read the next frame. This patch will only work for 2.1-dev but a minor adaptation will be needed for earlier versions (down to 1.9, where subscribe() was added). --- src/mux_h2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/mux_h2.c b/src/mux_h2.c index b58ba20bc..a1da04191 100644 --- a/src/mux_h2.c +++ b/src/mux_h2.c @@ -2753,7 +2753,7 @@ static int h2_recv(struct h2c *h2c) ret = max ? conn->xprt->rcv_buf(conn, conn->xprt_ctx, buf, max, 0) : 0; - if (h2_recv_allowed(h2c) && (b_data(buf) < buf->size)) + if (max && !ret && h2_recv_allowed(h2c)) conn->xprt->subscribe(conn, conn->xprt_ctx, SUB_RETRY_RECV, &h2c->wait_event); if (!b_data(buf)) {