From afe57846bfb2edfb0db53f942b9500d090377c54 Mon Sep 17 00:00:00 2001
From: Christopher Faulet <cfaulet@haproxy.com>
Date: Mon, 21 Jan 2019 11:55:02 +0100
Subject: [PATCH] BUG/MINOR: mux-h1: Apply the reserve on the channel's buffer
 only

There is no reason to use the reserve to limit the amount of data of the input
buffer that we can parse at a time. The only important thing is to keep the
reserve free in the channel's buffer.

This patch should be backported to 1.9.
---
 src/mux_h1.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/src/mux_h1.c b/src/mux_h1.c
index 4b0f46b63..a5d60c3c4 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -1064,12 +1064,17 @@ static size_t h1_process_headers(struct h1s *h1s, struct h1m *h1m, struct htx *h
  */
 static size_t h1_process_data(struct h1s *h1s, struct h1m *h1m, struct htx *htx,
 			      struct buffer *buf, size_t *ofs, size_t max,
-			      struct buffer *htxbuf)
+			      struct buffer *htxbuf, size_t reserve)
 {
-	uint32_t data_space = htx_free_data_space(htx);
+	uint32_t data_space;
 	size_t total = 0;
 	int ret = 0;
 
+	data_space = htx_free_data_space(htx);
+	if (data_space <= reserve)
+		goto end;
+	data_space -= reserve;
+
 	if (h1m->flags & H1_MF_XFER_LEN) {
 		if (h1m->flags & H1_MF_CLEN) {
 			/* content-length: read only h2m->body_len */
@@ -1175,6 +1180,10 @@ static size_t h1_process_data(struct h1s *h1s, struct h1m *h1m, struct htx *htx,
 				}
 				if (!h1m->curr_len) {
 					h1m->state = H1_MSG_CHUNK_CRLF;
+					data_space = htx_free_data_space(htx);
+					if (data_space <= reserve)
+						goto end;
+					data_space -= reserve;
 					goto new_chunk;
 				}
 				goto end;
@@ -1303,22 +1312,14 @@ static size_t h1_process_input(struct h1c *h1c, struct buffer *buf, int flags)
 	struct htx *htx;
 	size_t total = 0;
 	size_t ret = 0;
-	size_t count, max;
+	size_t count, rsv;
 	int errflag;
 
 	htx = htx_from_buf(buf);
 	count = b_data(&h1c->ibuf);
-	max = htx_free_space(htx);
-	if (flags & CO_RFL_KEEP_RSV) {
-		if (max < global.tune.maxrewrite)
-			goto end;
-		max -= global.tune.maxrewrite;
-	}
-	if (count > max)
-		count = max;
-
 	if (!count)
 		goto end;
+	rsv = ((flags & CO_RFL_KEEP_RSV) ? global.tune.maxrewrite : 0);
 
 	if (!conn_is_back(h1c->conn)) {
 		h1m = &h1s->req;
@@ -1336,7 +1337,7 @@ static size_t h1_process_input(struct h1c *h1c, struct buffer *buf, int flags)
 				break;
 		}
 		else if (h1m->state <= H1_MSG_TRAILERS) {
-			ret = h1_process_data(h1s, h1m, htx, &h1c->ibuf, &total, count, buf);
+			ret = h1_process_data(h1s, h1m, htx, &h1c->ibuf, &total, count, buf, rsv);
 			htx = htx_from_buf(buf);
 			if (!ret)
 				break;
@@ -1346,7 +1347,7 @@ static size_t h1_process_input(struct h1c *h1c, struct buffer *buf, int flags)
 			break;
 		}
 		else if (h1m->state == H1_MSG_TUNNEL) {
-			ret = h1_process_data(h1s, h1m, htx, &h1c->ibuf, &total, count, buf);
+			ret = h1_process_data(h1s, h1m, htx, &h1c->ibuf, &total, count, buf, rsv);
 			htx = htx_from_buf(buf);
 			if (!ret)
 				break;