diff --git a/contrib/opentracing/src/pool.c b/contrib/opentracing/src/pool.c
new file mode 100644
index 0000000..2f4b534
--- /dev/null
+++ b/contrib/opentracing/src/pool.c
@@ -0,0 +1,223 @@
+/***
+ * 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_pool_alloc -
+ *
+ * ARGUMENTS
+ *   pool       -
+ *   size       -
+ *   flag_clear -
+ *   err        -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+void *flt_ot_pool_alloc(struct pool_head *pool, size_t size, bool flag_clear, char **err)
+{
+	void *retptr;
+
+	FLT_OT_FUNC("%p, %zu, %hhu, %p:%p", pool, size, flag_clear, FLT_OT_DPTR_ARGS(err));
+
+	if (pool != NULL) {
+		retptr = pool_alloc_dirty(pool);
+		if (retptr != NULL)
+			FLT_OT_DBG(2, "POOL_ALLOC: %s:%d(%p %zu)", __func__, __LINE__, retptr, FLT_OT_DEREF(pool, size, size));
+	} else {
+		retptr = FLT_OT_MALLOC(size);
+	}
+
+	if (retptr == NULL)
+		FLT_OT_ERR("out of memory");
+	else if (flag_clear)
+		(void)memset(retptr, 0, size);
+
+	FLT_OT_RETURN(retptr);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_pool_strndup -
+ *
+ * ARGUMENTS
+ *   pool -
+ *   s    -
+ *   size -
+ *   err  -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   -
+ */
+void *flt_ot_pool_strndup(struct pool_head *pool, const char *s, size_t size, char **err)
+{
+	void *retptr;
+
+	FLT_OT_FUNC("%p, \"%.*s\", %zu, %p:%p", pool, (int)size, s, size, FLT_OT_DPTR_ARGS(err));
+
+	if (pool != NULL) {
+		retptr = pool_alloc_dirty(pool);
+		if (retptr != NULL) {
+			(void)memcpy(retptr, s, MIN(pool->size - 1, size));
+
+			((uint8_t *)retptr)[MIN(pool->size - 1, size)] = '\0';
+		}
+	} else {
+		retptr = FLT_OT_STRNDUP(s, size);
+	}
+
+	if (retptr != NULL)
+		FLT_OT_DBG(2, "POOL_STRNDUP: %s:%d(%p %zu)", __func__, __LINE__, retptr, FLT_OT_DEREF(pool, size, size));
+	else
+		FLT_OT_ERR("out of memory");
+
+	FLT_OT_RETURN(retptr);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_pool_free -
+ *
+ * ARGUMENTS
+ *   pool -
+ *   ptr  -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   This function does not return a value.
+ */
+void flt_ot_pool_free(struct pool_head *pool, void **ptr)
+{
+	FLT_OT_FUNC("%p, %p:%p", pool, FLT_OT_DPTR_ARGS(ptr));
+
+	if ((ptr == NULL) || (*ptr == NULL))
+		FLT_OT_RETURN();
+
+	FLT_OT_DBG(2, "POOL_FREE: %s:%d(%p %u)", __func__, __LINE__, *ptr, FLT_OT_DEREF(pool, size, 0));
+
+	if (pool != NULL)
+		pool_free(pool, *ptr);
+	else
+		FLT_OT_FREE(*ptr);
+
+	*ptr = NULL;
+
+	FLT_OT_RETURN();
+}
+
+
+/***
+ * NAME
+ *   flt_ot_trash_alloc -
+ *
+ * ARGUMENTS
+ *   flag_clear -
+ *   err        -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   This function does not return a value.
+ */
+struct buffer *flt_ot_trash_alloc(bool flag_clear, char **err)
+{
+	struct buffer *retptr;
+
+	FLT_OT_FUNC("%hhu, %p:%p", flag_clear, FLT_OT_DPTR_ARGS(err));
+
+#ifdef USE_TRASH_CHUNK
+	retptr = alloc_trash_chunk();
+	if (retptr != NULL)
+		FLT_OT_DBG(2, "TRASH_ALLOC: %s:%d(%p %zu)", __func__, __LINE__, retptr, retptr->size);
+#else
+	retptr = FLT_OT_MALLOC(sizeof(*retptr));
+	if (retptr != NULL) {
+		chunk_init(retptr, FLT_OT_MALLOC(global.tune.bufsize), global.tune.bufsize);
+		if (retptr->area == NULL)
+			FLT_OT_FREE_CLEAR(retptr);
+		else
+			*(retptr->area) = '\0';
+	}
+#endif
+
+	if (retptr == NULL)
+		FLT_OT_ERR("out of memory");
+	else if (flag_clear)
+		(void)memset(retptr->area, 0, retptr->size);
+
+	FLT_OT_RETURN(retptr);
+}
+
+
+/***
+ * NAME
+ *   flt_ot_trash_free -
+ *
+ * ARGUMENTS
+ *   ptr -
+ *
+ * DESCRIPTION
+ *   -
+ *
+ * RETURN VALUE
+ *   This function does not return a value.
+ */
+void flt_ot_trash_free(struct buffer **ptr)
+{
+	FLT_OT_FUNC("%p:%p", FLT_OT_DPTR_ARGS(ptr));
+
+	if ((ptr == NULL) || (*ptr == NULL))
+		FLT_OT_RETURN();
+
+	FLT_OT_DBG(2, "TRASH_FREE: %s:%d(%p %zu)", __func__, __LINE__, *ptr, (*ptr)->size);
+
+#ifdef USE_TRASH_CHUNK
+	free_trash_chunk(*ptr);
+#else
+	FLT_OT_FREE((*ptr)->area);
+	FLT_OT_FREE(*ptr);
+#endif
+
+	*ptr = NULL;
+
+	FLT_OT_RETURN();
+}
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ *
+ * vi: noexpandtab shiftwidth=8 tabstop=8
+ */