diff --git a/contrib/opentracing/src/cli.c b/contrib/opentracing/src/cli.c
new file mode 100644
index 0000000..529c687
--- /dev/null
+++ b/contrib/opentracing/src/cli.c
@@ -0,0 +1,395 @@
+/***
+ * Copyright 2020 HAProxy Technologies
+ *
+ * This file is part of the HAProxy OpenTracing filter.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "include.h"
+
+
+/***
+ * NAME
+ *   flt_ot_cli_set_msg -
+ *
+ * ARGUMENTS
+ *   appctx    -
+ *   err       -
+ *   msg       -
+ *   cli_state -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   This function does not return a value.
+ */
+static void cmn_cli_set_msg(struct appctx *appctx, char *err, char *msg, int cli_state)
+{
+	FLT_OT_FUNC("%p, %p, %p, %d", appctx, err, msg, cli_state);
+
+	if ((appctx == NULL) || ((err == NULL) && (msg == NULL)))
+		FLT_OT_RETURN();
+
+	appctx->ctx.cli.err = (err == NULL) ? msg : err;
+	appctx->st0         = (appctx->ctx.cli.err == NULL) ? CLI_ST_PROMPT : cli_state;
+
+	FLT_OT_DBG(1, "err(%d): \"%s\"", appctx->st0, appctx->ctx.cli.err);
+
+	FLT_OT_RETURN();
+}
+
+
+#ifdef DEBUG_OT
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_debug -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_debug(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	char    *err = NULL, *msg = NULL;
+	uint8_t  value;
+	int      retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+
+	if (FLT_OT_ARG_ISVALID(2)) {
+		value = flt_ot_strtoll(args[2], 0, 255, &err);
+		if (err == NULL) {
+			_HA_ATOMIC_STORE(&(flt_ot_debug.level), value);
+
+			(void)memprintf(&msg, FLT_OT_CLI_CMD " : debug level set to %hhu", value);
+		} else {
+			retval = 1;
+		}
+	} else {
+		value = _HA_ATOMIC_LOAD(&(flt_ot_debug.level));
+
+		(void)memprintf(&msg, FLT_OT_CLI_CMD " : current debug level is %hhu", value);
+	}
+
+	cmn_cli_set_msg(appctx, err, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+#endif /* DEBUG_OT */
+
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_disabled -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_disabled(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	char *msg = NULL;
+	bool  value = (uintptr_t)private;
+	int   retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+
+	FLT_OT_PROXIES_LIST_START() {
+		_HA_ATOMIC_STORE(&(conf->tracer->flag_disabled), value);
+
+		(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : filter %sabled", FLT_OT_CLI_MSG_CAT(msg), value ? "dis" : "en");
+	} FLT_OT_PROXIES_LIST_END();
+
+	cmn_cli_set_msg(appctx, NULL, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_option -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_option(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	char *msg = NULL;
+	bool  value = (uintptr_t)private;
+	int   retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+
+	FLT_OT_PROXIES_LIST_START() {
+		_HA_ATOMIC_STORE(&(conf->tracer->flag_harderr), value);
+
+		(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : filter set %s-errors", FLT_OT_CLI_MSG_CAT(msg), value ? "hard" : "soft");
+	} FLT_OT_PROXIES_LIST_END();
+
+	cmn_cli_set_msg(appctx, NULL, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_logging -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_logging(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	char    *err = NULL, *msg = NULL;
+	uint8_t  value;
+	int      retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+
+	if (FLT_OT_ARG_ISVALID(2)) {
+		if (strcasecmp(args[2], FLT_OT_CLI_LOGGING_OFF) == 0) {
+			value = FLT_OT_LOGGING_OFF;
+		}
+		else if (strcasecmp(args[2], FLT_OT_CLI_LOGGING_ON) == 0) {
+			value = FLT_OT_LOGGING_ON;
+		}
+		else if (strcasecmp(args[2], FLT_OT_CLI_LOGGING_NOLOGNORM) == 0) {
+			value = FLT_OT_LOGGING_ON | FLT_OT_LOGGING_NOLOGNORM;
+		}
+		else {
+			(void)memprintf(&err, "'%s' : invalid value, use <" FLT_OT_CLI_LOGGING_OFF " | " FLT_OT_CLI_LOGGING_ON " | " FLT_OT_CLI_LOGGING_NOLOGNORM ">", args[2]);
+
+			retval = 1;
+		}
+
+		if (retval == 0) {
+			FLT_OT_PROXIES_LIST_START() {
+				_HA_ATOMIC_STORE(&(conf->tracer->logging), value);
+
+				(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : logging is %s", FLT_OT_CLI_MSG_CAT(msg), FLT_OT_CLI_LOGGING_STATE(value));
+			} FLT_OT_PROXIES_LIST_END();
+		}
+	} else {
+		FLT_OT_PROXIES_LIST_START() {
+			value = _HA_ATOMIC_LOAD(&(conf->tracer->logging));
+
+			(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : logging is currently %s", FLT_OT_CLI_MSG_CAT(msg), FLT_OT_CLI_LOGGING_STATE(value));
+		} FLT_OT_PROXIES_LIST_END();
+	}
+
+	cmn_cli_set_msg(appctx, err, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_rate -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_rate(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	char     *err = NULL, *msg = NULL;
+	uint32_t  value;
+	int       retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+
+	if (FLT_OT_ARG_ISVALID(2)) {
+		value = FLT_OT_FLOAT_U32(flt_ot_strtod(args[2], 0.0, FLT_OT_RATE_LIMIT_MAX, &err), FLT_OT_RATE_LIMIT_MAX);
+		if (err == NULL) {
+			FLT_OT_PROXIES_LIST_START() {
+				_HA_ATOMIC_STORE(&(conf->tracer->rate_limit), value);
+
+				(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : rate limit set to %.2f", FLT_OT_CLI_MSG_CAT(msg), FLT_OT_U32_FLOAT(value, FLT_OT_RATE_LIMIT_MAX));
+			} FLT_OT_PROXIES_LIST_END();
+		} else {
+			retval = 1;
+		}
+	} else {
+		FLT_OT_PROXIES_LIST_START() {
+			value = _HA_ATOMIC_LOAD(&(conf->tracer->rate_limit));
+
+			(void)memprintf(&msg, "%s%s" FLT_OT_CLI_CMD " : current rate limit is %.2f", FLT_OT_CLI_MSG_CAT(msg), FLT_OT_U32_FLOAT(value, FLT_OT_RATE_LIMIT_MAX));
+		} FLT_OT_PROXIES_LIST_END();
+	}
+
+	cmn_cli_set_msg(appctx, err, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_cli_parse_status -
+ *
+ * ARGUMENTS
+ *   args    -
+ *   payload -
+ *   appctx  -
+ *   private -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+static int flt_ot_cli_parse_status(char **args, char *payload, struct appctx *appctx, void *private)
+{
+	const char *nl = "";
+	char       *msg = NULL;
+	int         retval = 0;
+
+	FLT_OT_FUNC("%p, \"%s\", %p, %p", args, payload, appctx, private);
+
+	FLT_OT_ARGS_DUMP();
+	flt_ot_filters_dump();
+
+	(void)memprintf(&msg, " " FLT_OT_OPT_NAME " filter status\n" FLT_OT_STR_DASH_78);
+#ifdef DEBUG_OT
+	(void)memprintf(&msg, "%s\n   debug level: 0x%02hhx\n", msg, flt_ot_debug.level);
+#endif
+
+	FLT_OT_PROXIES_LIST_START() {
+		(void)memprintf(&msg, "%s\n%s   filter %s\n", msg, nl, conf->id);
+		(void)memprintf(&msg, "%s     configuration: %s\n", msg, conf->cfg_file);
+		(void)memprintf(&msg, "%s     disable count: %" PRIu64 " %" PRIu64 "\n\n", msg, conf->cnt.disabled[0], conf->cnt.disabled[1]);
+		(void)memprintf(&msg, "%s     tracer %s\n", msg, conf->tracer->id);
+		(void)memprintf(&msg, "%s       configuration: %s\n", msg, conf->tracer->config);
+		(void)memprintf(&msg, "%s       plugin:        %s\n", msg, conf->tracer->plugin);
+		(void)memprintf(&msg, "%s       rate limit:    %.2f %%\n", msg, FLT_OT_U32_FLOAT(conf->tracer->rate_limit, FLT_OT_RATE_LIMIT_MAX));
+		(void)memprintf(&msg, "%s       hard errors:   %s\n", msg, FLT_OT_STR_FLAG_YN(conf->tracer->flag_harderr));
+		(void)memprintf(&msg, "%s       disabled:      %s\n", msg, FLT_OT_STR_FLAG_YN(conf->tracer->flag_disabled));
+		(void)memprintf(&msg, "%s       logging:       %s\n", msg, FLT_OT_CLI_LOGGING_STATE(conf->tracer->logging));
+		(void)memprintf(&msg, "%s       analyzers:     %08x", msg, conf->tracer->analyzers);
+
+		nl = "\n";
+	} FLT_OT_PROXIES_LIST_END();
+
+	cmn_cli_set_msg(appctx, NULL, msg, CLI_ST_PRINT_FREE);
+
+	FLT_OT_RETURN(retval);
+}
+
+
+static struct cli_kw_list cli_kws = { { }, {
+#ifdef DEBUG_OT
+	{ { FLT_OT_CLI_CMD, "debug", NULL }, FLT_OT_CLI_CMD " debug [level]   : set the OT filter debug level (default: get current debug level)", flt_ot_cli_parse_debug, NULL, NULL, NULL, 0 },
+#endif
+	{ { FLT_OT_CLI_CMD, "disable", NULL }, FLT_OT_CLI_CMD " disable         : disable the OT filter", flt_ot_cli_parse_disabled, NULL, NULL, (void *)1, 0 },
+	{ { FLT_OT_CLI_CMD, "enable", NULL }, FLT_OT_CLI_CMD " enable          : enable the OT filter", flt_ot_cli_parse_disabled, NULL, NULL, (void *)0, 0 },
+	{ { FLT_OT_CLI_CMD, "soft-errors", NULL }, FLT_OT_CLI_CMD " soft-errors     : turning off hard-errors mode", flt_ot_cli_parse_option, NULL, NULL, (void *)0, 0 },
+	{ { FLT_OT_CLI_CMD, "hard-errors", NULL }, FLT_OT_CLI_CMD " hard-errors     : enabling hard-errors mode", flt_ot_cli_parse_option, NULL, NULL, (void *)1, 0 },
+	{ { FLT_OT_CLI_CMD, "logging",  NULL }, FLT_OT_CLI_CMD " logging [state] : set logging state (default: get current logging state)", flt_ot_cli_parse_logging, NULL, NULL, NULL, 0 },
+	{ { FLT_OT_CLI_CMD, "rate", NULL }, FLT_OT_CLI_CMD " rate [value]    : set the rate limit (default: get current rate value)", flt_ot_cli_parse_rate, NULL, NULL, NULL, 0 },
+	{ { FLT_OT_CLI_CMD, "status", NULL }, FLT_OT_CLI_CMD " status          : show the OT filter status", flt_ot_cli_parse_status, NULL, NULL, NULL, 0 },
+	{ /* END */ }
+}};
+
+
+/***
+ * NAME
+ *   flt_ot_cli_init -
+ *
+ * ARGUMENTS
+ *   This function takes no arguments.
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   This function does not return a value.
+ */
+void flt_ot_cli_init(void)
+{
+	FLT_OT_FUNC("");
+
+	/* Register CLI keywords. */
+	cli_register_kw(&cli_kws);
+
+	FLT_OT_RETURN();
+}
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */