[dpdk-dev] [PATCH v2 5/7] bpf: introduce basic RX/TX BPF filters

[Konstantin Ananyev <konstantin.ananyev@intel.com>]

Introduce API to install BPF based filters on ethdev RX/TX path.
Current implementation is pure SW one, based on ethdev RX/TX
callback mechanism.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
 lib/librte_bpf/Makefile            |   2 +
 lib/librte_bpf/bpf_pkt.c           | 607 +++++++++++++++++++++++++++++++++++++
 lib/librte_bpf/meson.build         |   6 +-
 lib/librte_bpf/rte_bpf_ethdev.h    | 100 ++++++
 lib/librte_bpf/rte_bpf_version.map |   4 +
 5 files changed, 717 insertions(+), 2 deletions(-)
 create mode 100644 lib/librte_bpf/bpf_pkt.c
 create mode 100644 lib/librte_bpf/rte_bpf_ethdev.h

diff --git a/lib/librte_bpf/Makefile b/lib/librte_bpf/Makefile
index 44b12c439..501c49c60 100644
--- a/lib/librte_bpf/Makefile
+++ b/lib/librte_bpf/Makefile
@@ -22,6 +22,7 @@ LIBABIVER := 1
 SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf.c
 SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf_exec.c
 SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf_load.c
+SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf_pkt.c
 SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf_validate.c
 ifeq ($(CONFIG_RTE_ARCH_X86_64),y)
 SRCS-$(CONFIG_RTE_LIBRTE_BPF) += bpf_jit_x86.c
@@ -29,5 +30,6 @@ endif
 
 # install header files
 SYMLINK-$(CONFIG_RTE_LIBRTE_BPF)-include += rte_bpf.h
+SYMLINK-$(CONFIG_RTE_LIBRTE_BPF)-include += rte_bpf_ethdev.h
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_bpf/bpf_pkt.c b/lib/librte_bpf/bpf_pkt.c
new file mode 100644
index 000000000..287d40564
--- /dev/null
+++ b/lib/librte_bpf/bpf_pkt.c
@@ -0,0 +1,607 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include <sys/queue.h>
+#include <sys/stat.h>
+
+#include <rte_common.h>
+#include <rte_byteorder.h>
+#include <rte_malloc.h>
+#include <rte_log.h>
+#include <rte_debug.h>
+#include <rte_cycles.h>
+#include <rte_eal.h>
+#include <rte_per_lcore.h>
+#include <rte_lcore.h>
+#include <rte_atomic.h>
+#include <rte_mbuf.h>
+#include <rte_ethdev.h>
+
+#include <rte_bpf_ethdev.h>
+#include "bpf_impl.h"
+
+/*
+ * information about installed BPF rx/tx callback
+ */
+
+struct bpf_eth_cbi {
+	/* used by both data & control path */
+	uint32_t use;    /*usage counter */
+	void *cb;        /* callback handle */
+	struct rte_bpf *bpf;
+	struct rte_bpf_jit jit;
+	/* used by control path only */
+	LIST_ENTRY(bpf_eth_cbi) link;
+	uint16_t port;
+	uint16_t queue;
+} __rte_cache_aligned;
+
+/*
+ * Odd number means that callback is used by datapath.
+ * Even number means that callback is not used by datapath.
+ */
+#define BPF_ETH_CBI_INUSE  1
+
+/*
+ * List to manage RX/TX installed callbacks.
+ */
+LIST_HEAD(bpf_eth_cbi_list, bpf_eth_cbi);
+
+enum {
+	BPF_ETH_RX,
+	BPF_ETH_TX,
+	BPF_ETH_NUM,
+};
+
+/*
+ * information about all installed BPF rx/tx callbacks
+ */
+struct bpf_eth_cbh {
+	rte_spinlock_t lock;
+	struct bpf_eth_cbi_list list;
+	uint32_t type;
+};
+
+static struct bpf_eth_cbh rx_cbh = {
+	.lock = RTE_SPINLOCK_INITIALIZER,
+	.list = LIST_HEAD_INITIALIZER(list),
+	.type = BPF_ETH_RX,
+};
+
+static struct bpf_eth_cbh tx_cbh = {
+	.lock = RTE_SPINLOCK_INITIALIZER,
+	.list = LIST_HEAD_INITIALIZER(list),
+	.type = BPF_ETH_TX,
+};
+
+/*
+ * Marks given callback as used by datapath.
+ */
+static __rte_always_inline void
+bpf_eth_cbi_inuse(struct bpf_eth_cbi *cbi)
+{
+	cbi->use++;
+	/* make sure no store/load reordering could happen */
+	rte_smp_mb();
+}
+
+/*
+ * Marks given callback list as not used by datapath.
+ */
+static __rte_always_inline void
+bpf_eth_cbi_unuse(struct bpf_eth_cbi *cbi)
+{
+	/* make sure all previous loads are completed */
+	rte_smp_rmb();
+	cbi->use++;
+}
+
+/*
+ * Waits till datapath finished using given callback.
+ */
+static void
+bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
+{
+	uint32_t nuse, puse;
+
+	/* make sure all previous loads and stores are completed */
+	rte_smp_mb();
+
+	puse = cbi->use;
+
+	/* in use, busy wait till current RX/TX iteration is finished */
+	if ((puse & BPF_ETH_CBI_INUSE) != 0) {
+		do {
+			rte_pause();
+			rte_compiler_barrier();
+			nuse = cbi->use;
+		} while (nuse == puse);
+	}
+}
+
+static void
+bpf_eth_cbi_cleanup(struct bpf_eth_cbi *bc)
+{
+	bc->bpf = NULL;
+	memset(&bc->jit, 0, sizeof(bc->jit));
+}
+
+static struct bpf_eth_cbi *
+bpf_eth_cbh_find(struct bpf_eth_cbh *cbh, uint16_t port, uint16_t queue)
+{
+	struct bpf_eth_cbi *cbi;
+
+	LIST_FOREACH(cbi, &cbh->list, link) {
+		if (cbi->port == port && cbi->queue == queue)
+			break;
+	}
+	return cbi;
+}
+
+static struct bpf_eth_cbi *
+bpf_eth_cbh_add(struct bpf_eth_cbh *cbh, uint16_t port, uint16_t queue)
+{
+	struct bpf_eth_cbi *cbi;
+
+	/* return an existing one */
+	cbi = bpf_eth_cbh_find(cbh, port, queue);
+	if (cbi != NULL)
+		return cbi;
+
+	cbi = rte_zmalloc(NULL, sizeof(*cbi), RTE_CACHE_LINE_SIZE);
+	if (cbi != NULL) {
+		cbi->port = port;
+		cbi->queue = queue;
+		LIST_INSERT_HEAD(&cbh->list, cbi, link);
+	}
+	return cbi;
+}
+
+/*
+ * BPF packet processing routinies.
+ */
+
+static inline uint32_t
+apply_filter(struct rte_mbuf *mb[], const uint64_t rc[], uint32_t num,
+	uint32_t drop)
+{
+	uint32_t i, j, k;
+	struct rte_mbuf *dr[num];
+
+	for (i = 0, j = 0, k = 0; i != num; i++) {
+
+		/* filter matches */
+		if (rc[i] != 0)
+			mb[j++] = mb[i];
+		/* no match */
+		else
+			dr[k++] = mb[i];
+	}
+
+	if (drop != 0) {
+		/* free filtered out mbufs */
+		for (i = 0; i != k; i++)
+			rte_pktmbuf_free(dr[i]);
+	} else {
+		/* copy filtered out mbufs beyond good ones */
+		for (i = 0; i != k; i++)
+			mb[j + i] = dr[i];
+	}
+
+	return j;
+}
+
+static inline uint32_t
+pkt_filter_vm(const struct rte_bpf *bpf, struct rte_mbuf *mb[], uint32_t num,
+	uint32_t drop)
+{
+	uint32_t i;
+	void *dp[num];
+	uint64_t rc[num];
+
+	for (i = 0; i != num; i++)
+		dp[i] = rte_pktmbuf_mtod(mb[i], void *);
+
+	rte_bpf_exec_burst(bpf, dp, rc, num);
+	return apply_filter(mb, rc, num, drop);
+}
+
+static inline uint32_t
+pkt_filter_jit(const struct rte_bpf_jit *jit, struct rte_mbuf *mb[],
+	uint32_t num, uint32_t drop)
+{
+	uint32_t i, n;
+	void *dp;
+	uint64_t rc[num];
+
+	n = 0;
+	for (i = 0; i != num; i++) {
+		dp = rte_pktmbuf_mtod(mb[i], void *);
+		rc[i] = jit->func(dp);
+		n += (rc[i] == 0);
+	}
+
+	if (n != 0)
+		num = apply_filter(mb, rc, num, drop);
+
+	return num;
+}
+
+static inline uint32_t
+pkt_filter_mb_vm(const struct rte_bpf *bpf, struct rte_mbuf *mb[], uint32_t num,
+	uint32_t drop)
+{
+	uint64_t rc[num];
+
+	rte_bpf_exec_burst(bpf, (void **)mb, rc, num);
+	return apply_filter(mb, rc, num, drop);
+}
+
+static inline uint32_t
+pkt_filter_mb_jit(const struct rte_bpf_jit *jit, struct rte_mbuf *mb[],
+	uint32_t num, uint32_t drop)
+{
+	uint32_t i, n;
+	uint64_t rc[num];
+
+	n = 0;
+	for (i = 0; i != num; i++) {
+		rc[i] = jit->func(mb[i]);
+		n += (rc[i] == 0);
+	}
+
+	if (n != 0)
+		num = apply_filter(mb, rc, num, drop);
+
+	return num;
+}
+
+/*
+ * RX/TX callbacks for raw data bpf.
+ */
+
+static uint16_t
+bpf_rx_callback_vm(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts,
+	__rte_unused uint16_t max_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_vm(cbi->bpf, pkt, nb_pkts, 1) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_rx_callback_jit(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts,
+	__rte_unused uint16_t max_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_jit(&cbi->jit, pkt, nb_pkts, 1) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_tx_callback_vm(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_vm(cbi->bpf, pkt, nb_pkts, 0) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_tx_callback_jit(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_jit(&cbi->jit, pkt, nb_pkts, 0) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+/*
+ * RX/TX callbacks for mbuf.
+ */
+
+static uint16_t
+bpf_rx_callback_mb_vm(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts,
+	__rte_unused uint16_t max_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_mb_vm(cbi->bpf, pkt, nb_pkts, 1) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_rx_callback_mb_jit(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts,
+	__rte_unused uint16_t max_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_mb_jit(&cbi->jit, pkt, nb_pkts, 1) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_tx_callback_mb_vm(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_mb_vm(cbi->bpf, pkt, nb_pkts, 0) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static uint16_t
+bpf_tx_callback_mb_jit(__rte_unused uint16_t port, __rte_unused uint16_t queue,
+	struct rte_mbuf *pkt[], uint16_t nb_pkts, void *user_param)
+{
+	struct bpf_eth_cbi *cbi;
+	uint16_t rc;
+
+	cbi = user_param;
+	bpf_eth_cbi_inuse(cbi);
+	rc = (cbi->cb != NULL) ?
+		pkt_filter_mb_jit(&cbi->jit, pkt, nb_pkts, 0) :
+		nb_pkts;
+	bpf_eth_cbi_unuse(cbi);
+	return rc;
+}
+
+static rte_rx_callback_fn
+select_rx_callback(enum rte_bpf_prog_type ptype, uint32_t flags)
+{
+	if (flags & RTE_BPF_ETH_F_JIT) {
+		if (ptype == RTE_BPF_PROG_TYPE_UNSPEC)
+			return bpf_rx_callback_jit;
+		else if (ptype == RTE_BPF_PROG_TYPE_MBUF)
+			return bpf_rx_callback_mb_jit;
+	} else if (ptype == RTE_BPF_PROG_TYPE_UNSPEC)
+		return bpf_rx_callback_vm;
+	else if (ptype == RTE_BPF_PROG_TYPE_MBUF)
+		return bpf_rx_callback_mb_vm;
+
+	return NULL;
+}
+
+static rte_tx_callback_fn
+select_tx_callback(enum rte_bpf_prog_type ptype, uint32_t flags)
+{
+	if (flags & RTE_BPF_ETH_F_JIT) {
+		if (ptype == RTE_BPF_PROG_TYPE_UNSPEC)
+			return bpf_tx_callback_jit;
+		else if (ptype == RTE_BPF_PROG_TYPE_MBUF)
+			return bpf_tx_callback_mb_jit;
+	} else if (ptype == RTE_BPF_PROG_TYPE_UNSPEC)
+		return bpf_tx_callback_vm;
+	else if (ptype == RTE_BPF_PROG_TYPE_MBUF)
+		return bpf_tx_callback_mb_vm;
+
+	return NULL;
+}
+
+/*
+ * helper function to perform BPF unload for given port/queue.
+ * have to introduce extra complexity (and possible slowdown) here,
+ * as right now there is no safe generic way to remove RX/TX callback
+ * while IO is active.
+ * Still don't free memory allocated for callback handle itself,
+ * again right now there is no safe way to do that without stopping RX/TX
+ * on given port/queue first.
+ */
+static void
+bpf_eth_cbi_unload(struct bpf_eth_cbi *bc)
+{
+	/* mark this cbi as empty */
+	bc->cb = NULL;
+	rte_smp_mb();
+
+	/* make sure datapath doesn't use bpf anymore, then destroy bpf */
+	bpf_eth_cbi_wait(bc);
+	rte_bpf_destroy(bc->bpf);
+	bpf_eth_cbi_cleanup(bc);
+}
+
+static void
+bpf_eth_unload(struct bpf_eth_cbh *cbh, uint16_t port, uint16_t queue)
+{
+	struct bpf_eth_cbi *bc;
+
+	bc = bpf_eth_cbh_find(cbh, port, queue);
+	if (bc == NULL || bc->cb == NULL)
+		return;
+
+	if (cbh->type == BPF_ETH_RX)
+		rte_eth_remove_rx_callback(port, queue, bc->cb);
+	else
+		rte_eth_remove_tx_callback(port, queue, bc->cb);
+
+	bpf_eth_cbi_unload(bc);
+}
+
+
+__rte_experimental void
+rte_bpf_eth_rx_unload(uint16_t port, uint16_t queue)
+{
+	struct bpf_eth_cbh *cbh;
+
+	cbh = &rx_cbh;
+	rte_spinlock_lock(&cbh->lock);
+	bpf_eth_unload(cbh, port, queue);
+	rte_spinlock_unlock(&cbh->lock);
+}
+
+__rte_experimental void
+rte_bpf_eth_tx_unload(uint16_t port, uint16_t queue)
+{
+	struct bpf_eth_cbh *cbh;
+
+	cbh = &tx_cbh;
+	rte_spinlock_lock(&cbh->lock);
+	bpf_eth_unload(cbh, port, queue);
+	rte_spinlock_unlock(&cbh->lock);
+}
+
+static int
+bpf_eth_elf_load(struct bpf_eth_cbh *cbh, uint16_t port, uint16_t queue,
+	const struct rte_bpf_prm *prm, const char *fname, const char *sname,
+	uint32_t flags)
+{
+	int32_t rc;
+	struct bpf_eth_cbi *bc;
+	struct rte_bpf *bpf;
+	rte_rx_callback_fn frx;
+	rte_tx_callback_fn ftx;
+	struct rte_bpf_jit jit;
+
+	frx = NULL;
+	ftx = NULL;
+
+	if (prm == NULL || rte_eth_dev_is_valid_port(port) == 0 ||
+			queue >= RTE_MAX_QUEUES_PER_PORT)
+		return -EINVAL;
+
+	if (cbh->type == BPF_ETH_RX)
+		frx = select_rx_callback(prm->prog_type, flags);
+	else
+		ftx = select_tx_callback(prm->prog_type, flags);
+
+	if (frx == NULL && ftx == NULL) {
+		RTE_BPF_LOG(ERR, "%s(%u, %u): no callback selected;\n",
+			__func__, port, queue);
+		return -EINVAL;
+	}
+
+	bpf = rte_bpf_elf_load(prm, fname, sname);
+	if (bpf == NULL)
+		return -rte_errno;
+
+	rte_bpf_get_jit(bpf, &jit);
+
+	if ((flags & RTE_BPF_ETH_F_JIT) != 0 && jit.func == NULL) {
+		RTE_BPF_LOG(ERR, "%s(%u, %u): no JIT generated;\n",
+			__func__, port, queue);
+		rte_bpf_destroy(bpf);
+		rc = -ENOTSUP;
+	}
+
+	/* setup/update global callback info */
+	bc = bpf_eth_cbh_add(cbh, port, queue);
+	if (bc == NULL)
+		return -ENOMEM;
+
+	/* remove old one, if any */
+	if (bc->cb != NULL)
+		bpf_eth_unload(cbh, port, queue);
+
+	bc->bpf = bpf;
+	bc->jit = jit;
+
+	if (cbh->type == BPF_ETH_RX)
+		bc->cb = rte_eth_add_rx_callback(port, queue, frx, bc);
+	else
+		bc->cb = rte_eth_add_tx_callback(port, queue, ftx, bc);
+
+	if (bc->cb == NULL) {
+		rc = -rte_errno;
+		rte_bpf_destroy(bpf);
+		bpf_eth_cbi_cleanup(bc);
+	} else
+		rc = 0;
+
+	return rc;
+}
+
+__rte_experimental int
+rte_bpf_eth_rx_elf_load(uint16_t port, uint16_t queue,
+	const struct rte_bpf_prm *prm, const char *fname, const char *sname,
+	uint32_t flags)
+{
+	int32_t rc;
+	struct bpf_eth_cbh *cbh;
+
+	cbh = &rx_cbh;
+	rte_spinlock_lock(&cbh->lock);
+	rc = bpf_eth_elf_load(cbh, port, queue, prm, fname, sname, flags);
+	rte_spinlock_unlock(&cbh->lock);
+
+	return rc;
+}
+
+__rte_experimental int
+rte_bpf_eth_tx_elf_load(uint16_t port, uint16_t queue,
+	const struct rte_bpf_prm *prm, const char *fname, const char *sname,
+	uint32_t flags)
+{
+	int32_t rc;
+	struct bpf_eth_cbh *cbh;
+
+	cbh = &tx_cbh;
+	rte_spinlock_lock(&cbh->lock);
+	rc = bpf_eth_elf_load(cbh, port, queue, prm, fname, sname, flags);
+	rte_spinlock_unlock(&cbh->lock);
+
+	return rc;
+}
diff --git a/lib/librte_bpf/meson.build b/lib/librte_bpf/meson.build
index 67ca30533..39b464041 100644
--- a/lib/librte_bpf/meson.build
+++ b/lib/librte_bpf/meson.build
@@ -5,15 +5,17 @@ allow_experimental_apis = true
 sources = files('bpf.c',
 		'bpf_exec.c',
 		'bpf_load.c',
+		'bpf_pkt.c',
 		'bpf_validate.c')
 
 if arch_subdir == 'x86'
 	sources += files('bpf_jit_x86.c')
 endif
 
-install_headers = files('rte_bpf.h')
+install_headers = files('rte_bpf.h',
+			'rte_bpf_ethdev.h')
 
-deps += ['mbuf', 'net']
+deps += ['mbuf', 'net', 'ethdev']
 
 dep = dependency('libelf', required: false)
 if dep.found() == false
diff --git a/lib/librte_bpf/rte_bpf_ethdev.h b/lib/librte_bpf/rte_bpf_ethdev.h
new file mode 100644
index 000000000..33ce0c6c7
--- /dev/null
+++ b/lib/librte_bpf/rte_bpf_ethdev.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#ifndef _RTE_BPF_ETHDEV_H_
+#define _RTE_BPF_ETHDEV_H_
+
+#include <rte_bpf.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum {
+	RTE_BPF_ETH_F_NONE = 0,
+	RTE_BPF_ETH_F_JIT  = 0x1, /*< use compiled into native ISA code */
+};
+
+/**
+ * API to install BPF filter as RX/TX callbacks for eth devices.
+ * Note that right now:
+ * - it is not MT safe, i.e. it is not allowed to do load/unload for the
+ *   same port/queue from different threads in parallel.
+ * - though it allows to do load/unload at runtime
+ *   (while RX/TX is ongoing on given port/queue).
+ * - allows only one BPF program per port/queue,
+ * i.e. new load will replace previously loaded for that port/queue BPF program.
+ * Filter behaviour - if BPF program returns zero value for a given packet,
+ * then it will be dropped inside callback and no further processing
+ *   on RX - it will be dropped inside callback and no further processing
+ *   for that packet will happen.
+ *   on TX - packet will remain unsent, and it is responsibility of the user
+ *   to handle such situation (drop, try to send again, etc.).
+ */
+
+/**
+ * Unload previously loaded BPF program (if any) from given RX port/queue
+ * and remove appropriate RX port/queue callback.
+ *
+ * @param port
+ *   The identifier of the ethernet port
+ * @param queue
+ *   The identifier of the RX queue on the given port
+ */
+void rte_bpf_eth_rx_unload(uint16_t port, uint16_t queue);
+
+/**
+ * Unload previously loaded BPF program (if any) from given TX port/queue
+ * and remove appropriate TX port/queue callback.
+ *
+ * @param port
+ *   The identifier of the ethernet port
+ * @param queue
+ *   The identifier of the TX queue on the given port
+ */
+void rte_bpf_eth_tx_unload(uint16_t port, uint16_t queue);
+
+/**
+ * Load BPF program from the ELF file and install callback to execute it
+ * on given RX port/queue.
+ *
+ * @param port
+ *   The identifier of the ethernet port
+ * @param queue
+ *   The identifier of the RX queue on the given port
+ * @param fname
+ *  Pathname for a ELF file.
+ * @param sname
+ *  Name of the executable section within the file to load.
+ * @return
+ *   Zero on successful completion or negative error code otherwise.
+ */
+int rte_bpf_eth_rx_elf_load(uint16_t port, uint16_t queue,
+	const struct rte_bpf_prm *prm, const char *fname, const char *sname,
+	uint32_t flags);
+
+/**
+ * Load BPF program from the ELF file and install callback to execute it
+ * on given TX port/queue.
+ *
+ * @param port
+ *   The identifier of the ethernet port
+ * @param queue
+ *   The identifier of the TX queue on the given port
+ * @param fname
+ *  Pathname for a ELF file.
+ * @param sname
+ *  Name of the executable section within the file to load.
+ * @return
+ *   Zero on successful completion or negative error code otherwise.
+ */
+int rte_bpf_eth_tx_elf_load(uint16_t port, uint16_t queue,
+	const struct rte_bpf_prm *prm, const char *fname, const char *sname,
+	uint32_t flags);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_BPF_ETHDEV_H_ */
diff --git a/lib/librte_bpf/rte_bpf_version.map b/lib/librte_bpf/rte_bpf_version.map
index ff65144df..a203e088e 100644
--- a/lib/librte_bpf/rte_bpf_version.map
+++ b/lib/librte_bpf/rte_bpf_version.map
@@ -3,6 +3,10 @@ EXPERIMENTAL {
 
 	rte_bpf_destroy;
 	rte_bpf_elf_load;
+	rte_bpf_eth_rx_elf_load;
+	rte_bpf_eth_rx_unload;
+	rte_bpf_eth_tx_elf_load;
+	rte_bpf_eth_tx_unload;
 	rte_bpf_exec;
 	rte_bpf_exec_burst;
 	rte_bpf_get_jit;
-- 
2.13.6