From 5c959336fd9a88175ce11b72d04d02b83bd09ab8 Mon Sep 17 00:00:00 2001
From: Christopher Faulet <cfaulet@haproxy.com>
Date: Mon, 4 Dec 2023 15:26:23 +0100
Subject: [PATCH] MINOR: mux-quic: Add global option to enable/disable
 zero-copy forwarding

tune.quic.zero-copy-fwd-send can now be used to enable or disable the
zero-copy fast-forwarding for the QUIC mux only, for sends. For now, there
is no option to disable it for receives because it is not supported yet.

It is enabled ('on') by default.
---
 doc/configuration.txt |  9 ++++++++-
 src/cfgparse-quic.c   | 20 ++++++++++++++++++++
 src/mux_quic.c        |  5 +++++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/doc/configuration.txt b/doc/configuration.txt
index bcdaae1fa..10faa8613 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1221,6 +1221,7 @@ The following keywords are supported in the "global" section :
    - tune.quic.max-frame-loss
    - tune.quic.retry-threshold
    - tune.quic.socket-owner
+   - tune.quic.zero-copy-fwd-send
    - tune.rcvbuf.backend
    - tune.rcvbuf.client
    - tune.rcvbuf.frontend
@@ -2927,7 +2928,7 @@ tune.disable-zero-copy-forwarding
 
   See also: tune.pt.zero-copy-forwarding,
             tune.h1.zero-copy-fwd-recv, tune.h1.zero-copy-fwd-send,
-            tune.h2.zero-copy-fwd-send
+            tune.h2.zero-copy-fwd-send, tune.quic.zero-copy-fwd-send
 
 tune.events.max-events-at-once <number>
   Sets the number of events that may be processed at once by an asynchronous
@@ -3456,6 +3457,12 @@ tune.quic.socket-owner { connection | listener }
   is used globally, it will be forced on every listener instance, regardless of
   their individual configuration.
 
+tune.quit.zero-copy-fwd-send { on | off }
+  Enables ('on') of disabled ('off') the zero-copy sends of data for the QUIC
+  multiplexer. It is enabled by default.
+
+  See also: tune.disable-zero-copy-forwarding
+
 tune.rcvbuf.backend <number>
 tune.rcvbuf.frontend <number>
   For the kernel socket receive buffer size on non-connected sockets to this
diff --git a/src/cfgparse-quic.c b/src/cfgparse-quic.c
index 802940850..ec2dedacf 100644
--- a/src/cfgparse-quic.c
+++ b/src/cfgparse-quic.c
@@ -248,6 +248,25 @@ static int cfg_parse_quic_tune_setting(char **args, int section_type,
 	return 0;
 }
 
+/* config parser for global "tune.quic.zero-copy-fwd-send" */
+static int cfg_parse_quic_zero_copy_fwd_snd(char **args, int section_type, struct proxy *curpx,
+					    const struct proxy *defpx, const char *file, int line,
+					    char **err)
+{
+	if (too_many_args(1, args, err, NULL))
+		return -1;
+
+	if (strcmp(args[1], "on") == 0)
+		global.tune.no_zero_copy_fwd &= ~NO_ZERO_COPY_FWD_QUIC_SND;
+	else if (strcmp(args[1], "off") == 0)
+		global.tune.no_zero_copy_fwd |= NO_ZERO_COPY_FWD_QUIC_SND;
+	else {
+		memprintf(err, "'%s' expects 'on' or 'off'.", args[0]);
+		return -1;
+	}
+	return 0;
+}
+
 static struct cfg_kw_list cfg_kws = {ILH, {
 	{ CFG_GLOBAL, "tune.quic.socket-owner", cfg_parse_quic_tune_socket_owner },
 	{ CFG_GLOBAL, "tune.quic.backend.max-idle-timeou", cfg_parse_quic_time },
@@ -256,6 +275,7 @@ static struct cfg_kw_list cfg_kws = {ILH, {
 	{ CFG_GLOBAL, "tune.quic.frontend.max-idle-timeout", cfg_parse_quic_time },
 	{ CFG_GLOBAL, "tune.quic.max-frame-loss", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.retry-threshold", cfg_parse_quic_tune_setting },
+	{ CFG_GLOBAL, "tune.quic.zero-copy-fwd-send", cfg_parse_quic_zero_copy_fwd_snd },
 	{ 0, NULL, NULL }
 }};
 
diff --git a/src/mux_quic.c b/src/mux_quic.c
index 714bc32f9..a4afe9b27 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -2819,6 +2819,11 @@ static size_t qmux_nego_ff(struct stconn *sc, struct buffer *input, size_t count
 	/* stream layer has been detached so no transfer must occur after. */
 	BUG_ON_HOT(qcs->flags & QC_SF_DETACH);
 
+	if (global.tune.no_zero_copy_fwd & NO_ZERO_COPY_FWD_QUIC_SND) {
+		qcs->sd->iobuf.flags |= IOBUF_FL_NO_FF;
+		goto end;
+	}
+
 	if (!qcs->qcc->app_ops->nego_ff || !qcs->qcc->app_ops->done_ff) {
 		/* Fast forwading is not supported by the QUIC application layer */
 		qcs->sd->iobuf.flags |= IOBUF_FL_NO_FF;