From 5220ef25e3a7e96824760edf4e8e80d176879d76 Mon Sep 17 00:00:00 2001 From: Christopher Faulet Date: Wed, 27 Mar 2019 15:44:56 +0100 Subject: [PATCH] BUG/MINOR: mux-h1: Only skip invalid C-L headers on output When an HTTP request with an empty body is received, the flag HTX_SL_F_BODYLESS is set on the HTX start-line block. It is true if the header content-length is explicitly set to 0 or if it is omitted for a non chunked request. On the server side, when the request is reformatted, because HTX_SL_F_BODYLESS is set, the flag H1_MF_CLEN is added on the request parser. It is done to not add an header transfer-encoding on bodyless requests. But if an header content-length is explicitly set to 0, when it is parsed, because H1_MF_CLEN is set, the function h1_parse_cont_len_header() returns 0, meaning the header can be dropped. So in such case, a request without any header content-length is sent to the server. Some servers seems to reject empty POST requests with an error 411 when there is no header content-length. So to fix this issue, on the output side, only headers with an invalid content length are skipped, ie only when the function h1_parse_cont_len_header() returns a negative value. This patch must be backported to 1.9. --- src/mux_h1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/mux_h1.c b/src/mux_h1.c index 65e99153d0..2b4e1cf09a 100644 --- a/src/mux_h1.c +++ b/src/mux_h1.c @@ -1557,7 +1557,8 @@ static size_t h1_process_output(struct h1c *h1c, struct buffer *buf, size_t coun if (isteqi(n, ist("transfer-encoding"))) h1_parse_xfer_enc_header(h1m, v); else if (isteqi(n, ist("content-length"))) { - if (h1_parse_cont_len_header(h1m, &v) <= 0) + /* Only skip C-L header with invalid value. */ + if (h1_parse_cont_len_header(h1m, &v) < 0) goto skip_hdr; } else if (isteqi(n, ist("connection"))) { -- 2.47.3