MINOR: quic: split Tx options for FE/BE usage

This patch is similar to the previous one, except that it is focused on
Tx QUIC settings. It is now possible to toggle GSO and pacing on
frontend and backend sides independently.

As with previous patch, option are renamed to use "fe/be" unified
prefixes. This is part of the current serie of commits which unify QUI
settings. Older options are deprecated and will be removed on 3.5
release.

doc/configuration.txt

@@ -1893,16 +1893,19 @@ The following keywords are supported in the "global" section :
    - tune.quic.be.cc.max-frame-loss
    - tune.quic.be.cc.reorder-ratio
    - tune.quic.be.sec.glitches-threshold
+   - tune.quic.be.tx.pacing
+   - tune.quic.be.tx.udp-gso
    - tune.quic.cc.cubic.min-losses (deprecated)
    - tune.quic.cc-hystart (deprecated)
-   - tune.quic.disable-tx-pacing
+   - tune.quic.disable-tx-pacing (deprecated)
-   - tune.quic.disable-udp-gso
+   - tune.quic.disable-udp-gso (deprecated)
    - tune.quic.fe.cc.cubic-min-losses
    - tune.quic.fe.cc.hystart
    - tune.quic.fe.cc.max-frame-loss
    - tune.quic.fe.cc.reorder-ratio
    - tune.quic.fe.sec.glitches-threshold
-   - tune.quic.frontend.glitches-threshold (deprecated)
+   - tune.quic.fe.tx.pacing
+   - tune.quic.fe.tx.udp-gso
    - tune.quic.frontend.max-data-size
    - tune.quic.frontend.max-idle-timeout
    - tune.quic.frontend.max-streams-bidi
@@ -4697,22 +4700,6 @@ tune.pt.zero-copy-forwarding { on | off }
   See also: tune.disable-zero-copy-forwarding, option splice-auto,
             option splice-request and option splice-response
 
-tune.quic.disable-tx-pacing
-  Disables pacing support for QUIC emission. The purpose of pacing is to smooth
-  emission of data to reduce network losses. In most scenario, it will
-  significantly improve network throughput by avoiding retransmissions.
-  However, it can be useful to deactivate it for networks with very high
-  bandwidth/low latency characteristics to prevent unwanted delay and reduce
-  CPU consumption.
-
-  See also the "quic-cc-algo" bind option.
-
-tune.quic.disable-udp-gso
-  Disable UDP GSO emission. This kernel feature allows to emit multiple
-  datagrams via a single system call which is more efficient for large
-  transfer. It may be useful to disable it on developers suggestion when
-  suspecting an issue on emission.
-
 tune.quic.be.cc.cubic-min-losses <number>
 tune.quic.fe.cc.cubic-min-losses <number>
   Defines how many lost packets are needed for the Cubic congestion control
@@ -4793,6 +4780,35 @@ tune.quic.frontend.glitches-threshold <number> (deprecated)
   part of the streamlining process apply on QUIC configuration. If used, this
   setting will only be applied on frontend connections.
 
+tune.quic.be.tx.pacing { on | off }
+tune.quic.fe.tx.pacing { on | off }
+  Enables ('on') or disables ('off') pacing support for QUIC emission. By
+  default, it is active. The purpose of pacing is to smooth emission of data to
+  reduce network losses. In most scenario, it will significantly improve
+  network throughput by avoiding retransmissions. However, it can be useful to
+  deactivate it for networks with very high bandwidth/low latency
+  characteristics to prevent unwanted delay and reduce CPU consumption.
+
+  See also the "quic-cc-algo" bind option.
+
+tune.quic.disable-tx-pacing (deprecated)
+  This keyword has been deprecated in 3.3 and will be removed in 3.5. It is
+  part of the streamlining process apply on QUIC configuration. If used, this
+  setting will only be applied on frontend connections.
+
+tune.quic.be.tx.udp-gso { on | off }
+tune.quic.fe.tx.udp-gso { on | off }
+  Enables ('on') or disables ('off') UDP GSO support for QUIC emission. By
+  default, it is active. This kernel feature allows to emit multiple datagrams
+  via a single system call which is more efficient for large transfer. It may
+  be useful to disable it on developers suggestion when suspecting an issue on
+  emission.
+
+tune.quic.disable-udp-gso (deprecated)
+  This keyword has been deprecated in 3.3 and will be removed in 3.5. It is
+  part of the streamlining process apply on QUIC configuration. If used, this
+  setting will only be applied on frontend connections.
+
 tune.quic.frontend.max-data-size <size>
   This setting is the hard limit for the number of data bytes in flight over a
   QUIC frontend connection. It is reused as the value for the initial_max_data
@@ -17110,10 +17126,10 @@ quic-cc-algo { cubic | newreno | bbr | nocc }[(<args,...>)]
   similar to those used by TCP.
 
   Pacing is activated on top of the congestion algorithm to reduce loss and
-  improve throughput. It can be turned off via "tune.quic.disable-tx-pacing"
+  improve throughput. It can be turned off via "tune.quic.fe.tx.pacing" global
-  global keyword. In most cases, pacing should remain activated, especially
+  keyword. In most cases, pacing should remain activated, especially when using
-  when using BBR as it relies on it to work as expected. Using BBR without
+  BBR as it relies on it to work as expected. Using BBR without pacing may
-  pacing may cause slowdowns or high loss rates during transfers.
+  cause slowdowns or high loss rates during transfers.
 
   Default value: cubic
 

include/haproxy/quic_tune-t.h

@@ -15,11 +15,11 @@
 
 #define QUIC_TUNE_FE_LISTEN_OFF    0x00000001
 
-#define QUIC_TUNE_NO_PACING     0x00000001
-#define QUIC_TUNE_NO_UDP_GSO    0x00000002
 #define QUIC_TUNE_SOCK_PER_CONN 0x00000004
 
-#define QUIC_TUNE_FB_CC_HYSTART 0x00000001
+#define QUIC_TUNE_FB_TX_PACING  0x00000001
+#define QUIC_TUNE_FB_TX_UDP_GSO 0x00000002
+#define QUIC_TUNE_FB_CC_HYSTART 0x00000004
 
 struct quic_tune {
 	struct {

src/cfgparse-quic.c

@@ -27,10 +27,12 @@ struct quic_tune quic_tune = {
 	.fe = {
 		.cc_max_frame_loss = QUIC_DFLT_CC_MAX_FRAME_LOSS,
 		.cc_reorder_ratio  = QUIC_DFLT_CC_REORDER_RATIO,
+		.fb_opts = QUIC_TUNE_FB_TX_PACING|QUIC_TUNE_FB_TX_UDP_GSO,
 	},
 	.be = {
 		.cc_max_frame_loss = QUIC_DFLT_CC_MAX_FRAME_LOSS,
 		.cc_reorder_ratio  = QUIC_DFLT_CC_REORDER_RATIO,
+		.fb_opts = QUIC_TUNE_FB_TX_PACING|QUIC_TUNE_FB_TX_UDP_GSO,
 	},
 };
 
@@ -420,6 +422,7 @@ static int cfg_parse_quic_tune_setting0(char **args, int section_type,
                                         const struct proxy *defpx,
                                         const char *file, int line, char **err)
 {
+	int ret = 0;
 	int prefix_len = strlen("tune.quic.");
 	const char *suffix;
 
@@ -428,17 +431,23 @@ static int cfg_parse_quic_tune_setting0(char **args, int section_type,
 
 	suffix = args[0] + prefix_len;
 	if (strcmp(suffix, "disable-tx-pacing") == 0) {
-		quic_tune.options |= QUIC_TUNE_NO_PACING;
+		memprintf(err, "'%s' is deprecated in 3.3 and will be removed in 3.5. "
+		               "Please use the newer keyword syntax 'tune.quic.fe.tx.pacing'.", args[0]);
+		quic_tune.fe.fb_opts &= ~QUIC_TUNE_FB_TX_PACING;
+		ret = 1;
 	}
 	else if (strcmp(suffix, "disable-udp-gso") == 0) {
-		quic_tune.options |= QUIC_TUNE_NO_UDP_GSO;
+		memprintf(err, "'%s' is deprecated in 3.3 and will be removed in 3.5. "
+		               "Please use the newer keyword syntax 'tune.quic.fe.tx.udp-gso'.", args[0]);
+		quic_tune.fe.fb_opts &= ~QUIC_TUNE_FB_TX_UDP_GSO;
+		ret = 1;
 	}
 	else {
 		memprintf(err, "'%s' keyword unhandled (please report this bug).", args[0]);
 		return -1;
 	}
 
-	return 0;
+	return ret;
 }
 
 /* config parser for global "tune.quic.* {on|off}" */
@@ -485,6 +494,24 @@ static int cfg_parse_quic_tune_on_off(char **args, int section_type, struct prox
 		else
 			*ptr &= ~QUIC_TUNE_FB_CC_HYSTART;
 	}
+	else if (strcmp(suffix, "be.tx.pacing") == 0 ||
+	         strcmp(suffix, "fe.tx.pacing") == 0) {
+		uint *ptr = (suffix[0] == 'b') ? &quic_tune.be.fb_opts :
+		                                 &quic_tune.fe.fb_opts;
+		if (on)
+			*ptr |= QUIC_TUNE_FB_TX_PACING;
+		else
+			*ptr &= ~QUIC_TUNE_FB_TX_PACING;
+	}
+	else if (strcmp(suffix, "be.tx.udp-gso") == 0 ||
+	         strcmp(suffix, "fe.tx.udp-gso") == 0) {
+		uint *ptr = (suffix[0] == 'b') ? &quic_tune.be.fb_opts :
+		                                 &quic_tune.fe.fb_opts;
+		if (on)
+			*ptr |= QUIC_TUNE_FB_TX_UDP_GSO;
+		else
+			*ptr &= ~QUIC_TUNE_FB_TX_UDP_GSO;
+	}
 	else if (strcmp(suffix, "cc-hystart") == 0) {
 		memprintf(err, "'%s' is deprecated in 3.3 and will be removed in 3.5. "
 		               "Please use the newer keyword syntax 'tune.quic.fe.cc.hystart'.", args[0]);
@@ -508,8 +535,6 @@ static struct cfg_kw_list cfg_kws = {ILH, {
 	{ CFG_GLOBAL, "tune.quic.frontend.default-max-window-size", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.frontend.stream-data-ratio", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.retry-threshold", cfg_parse_quic_tune_setting },
-	{ CFG_GLOBAL, "tune.quic.disable-tx-pacing", cfg_parse_quic_tune_setting0 },
-	{ CFG_GLOBAL, "tune.quic.disable-udp-gso", cfg_parse_quic_tune_setting0 },
 	{ CFG_GLOBAL, "tune.quic.zero-copy-fwd-send", cfg_parse_quic_tune_on_off },
 
 	{ CFG_GLOBAL, "tune.quic.fe.cc.cubic-min-losses", cfg_parse_quic_tune_setting },
@@ -517,16 +542,22 @@ static struct cfg_kw_list cfg_kws = {ILH, {
 	{ CFG_GLOBAL, "tune.quic.fe.cc.max-frame-loss", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.fe.cc.reorder-ratio", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.fe.sec.glitches-threshold", cfg_parse_quic_tune_setting },
+	{ CFG_GLOBAL, "tune.quic.fe.tx.pacing", cfg_parse_quic_tune_on_off },
+	{ CFG_GLOBAL, "tune.quic.fe.tx.udp-gso", cfg_parse_quic_tune_on_off },
 
 	{ CFG_GLOBAL, "tune.quic.be.cc.cubic-min-losses", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.be.cc.hystart", cfg_parse_quic_tune_on_off },
 	{ CFG_GLOBAL, "tune.quic.be.cc.max-frame-loss", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.be.cc.reorder-ratio", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.be.sec.glitches-threshold", cfg_parse_quic_tune_setting },
+	{ CFG_GLOBAL, "tune.quic.be.tx.pacing", cfg_parse_quic_tune_on_off },
+	{ CFG_GLOBAL, "tune.quic.be.tx.udp-gso", cfg_parse_quic_tune_on_off },
 
 	/* legacy options */
 	{ CFG_GLOBAL, "tune.quic.cc-hystart", cfg_parse_quic_tune_on_off },
 	{ CFG_GLOBAL, "tune.quic.cc.cubic.min-losses", cfg_parse_quic_tune_setting },
+	{ CFG_GLOBAL, "tune.quic.disable-tx-pacing", cfg_parse_quic_tune_setting0 },
+	{ CFG_GLOBAL, "tune.quic.disable-udp-gso", cfg_parse_quic_tune_setting0 },
 	{ CFG_GLOBAL, "tune.quic.frontend.glitches-threshold", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.max-frame-loss", cfg_parse_quic_tune_setting },
 	{ CFG_GLOBAL, "tune.quic.reorder-ratio", cfg_parse_quic_tune_setting },

src/cfgparse.c

@@ -2978,7 +2978,7 @@ init_proxies_list_stage1:
 				  bind_conf->quic_cc_algo : default_quic_cc_algo;
 
 				if (!(cc_algo->flags & QUIC_CC_ALGO_FL_OPT_PACING) &&
-				    quic_tune.options & QUIC_TUNE_NO_PACING) {
+				    !(quic_tune.fe.fb_opts & QUIC_TUNE_FB_TX_PACING)) {
 					ha_warning("Binding [%s:%d] for %s %s: using the selected congestion algorithm without pacing may cause slowdowns or high loss rates during transfers.\n",
 					           bind_conf->file, bind_conf->line,
 					           proxy_type_str(curproxy), curproxy->id);

src/mux_quic.c

@@ -43,7 +43,7 @@ static void qmux_ctrl_room(struct qc_stream_desc *, uint64_t room);
 /* Returns true if pacing should be used for <conn> connection. */
 static int qcc_is_pacing_active(const struct connection *conn)
 {
-	return !(quic_tune.options & QUIC_TUNE_NO_PACING);
+	return quic_tune_conn_test(QUIC_TUNE_FB_TX_PACING, conn);
 }
 
 /* Free <rxbuf> instance and its inner data storage attached to <qcs> stream. */

src/proto_quic.c

@@ -780,7 +780,8 @@ static int quic_test_socketopts(void)
 	}
 
 	/* Check for UDP GSO support. */
-	if (!(quic_tune.options & QUIC_TUNE_NO_UDP_GSO)) {
+	if ((quic_tune.fe.fb_opts & QUIC_TUNE_FB_TX_UDP_GSO) ||
+	    (quic_tune.be.fb_opts & QUIC_TUNE_FB_TX_UDP_GSO)) {
 		ret = quic_test_gso();
 		if (ret < 0) {
 			goto err;
@@ -788,7 +789,8 @@ static int quic_test_socketopts(void)
 		else if (!ret) {
 			ha_diag_warning("Your platform does not support UDP GSO. "
 			                "This will be automatically disabled for QUIC transfer.\n");
-			quic_tune.options |= QUIC_TUNE_NO_UDP_GSO;
+			quic_tune.fe.fb_opts &= ~QUIC_TUNE_FB_TX_UDP_GSO;
+			quic_tune.be.fb_opts &= ~QUIC_TUNE_FB_TX_UDP_GSO;
 		}
 	}
 

src/quic_tx.c

@@ -810,7 +810,7 @@ static int qc_prep_pkts(struct quic_conn *qc, struct buffer *buf,
 				/* Everything sent. Continue within the same datagram. */
 				prv_pkt = cur_pkt;
 			}
-			else if (!(quic_tune.options & QUIC_TUNE_NO_UDP_GSO) &&
+			else if (quic_tune_test(QUIC_TUNE_FB_TX_UDP_GSO, qc) &&
 			         !(qc->flags & QUIC_FL_CONN_UDP_GSO_EIO) &&
 			         dglen == qc->path->mtu &&
 			         (char *)end < b_wrap(buf) &&