diff --git a/Makefile.am b/Makefile.am
index fc8f2f34..38e17bab 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,7 +25,8 @@ sync-with-kernel:
 	      ! -f $(KERNEL_DIR)/usr/include/linux/ivtv.h -o \
 	      ! -f $(KERNEL_DIR)/usr/include/linux/dvb/frontend.h -o \
 	      ! -f $(KERNEL_DIR)/usr/include/linux/dvb/dmx.h -o \
-	      ! -f $(KERNEL_DIR)/usr/include/linux/lirc.h ]; then \
+	      ! -f $(KERNEL_DIR)/usr/include/linux/lirc.h -o \
+	      ! -f $(KERNEL_DIR)/usr/include/linux/bpf.h ]; then \
 	  echo "Error you must set KERNEL_DIR to point to an extracted kernel source dir"; \
 	  echo "and run 'make headers_install' in \$$KERNEL_DIR."; \
 	  exit 1; \
@@ -43,6 +44,7 @@ sync-with-kernel:
 	cp $(top_srcdir)/include/linux/dvb/frontend.h $(top_srcdir)/lib/include/libdvbv5/dvb-frontend.h
 	cp -a $(KERNEL_DIR)/usr/include/linux/dvb/dmx.h $(top_srcdir)/include/linux/dvb
 	cp -a $(KERNEL_DIR)/usr/include/linux/lirc.h $(top_srcdir)/include/linux
+	cp -a $(KERNEL_DIR)/usr/include/linux/bpf.h $(top_srcdir)/include/linux
 	cp -a $(KERNEL_DIR)/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c $(top_srcdir)/utils/common
 	cp -a $(KERNEL_DIR)/drivers/media/common/v4l2-tpg/v4l2-tpg-colors.c $(top_srcdir)/utils/common
 	cp -a $(KERNEL_DIR)/include/media/tpg/v4l2-tpg* $(top_srcdir)/utils/common
diff --git a/configure.ac b/configure.ac
index dc1e9cbf..1f48913c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -167,6 +167,16 @@ AC_SUBST([X11_CFLAGS])
 AC_SUBST([X11_LIBS])
 AM_CONDITIONAL([HAVE_X11], [test x$x11_pkgconfig = xyes])
 
+PKG_CHECK_MODULES([LIBELF], [libelf], [libelf_pkgconfig=yes], [libelf_pkgconfig=no])
+AC_SUBST([LIBELF_CFLAGS])
+AC_SUBST([LIBELF_LIBS])
+AM_CONDITIONAL([HAVE_LIBELF], [test x$libelf_pkgconfig = xyes])
+if test "x$libelf_pkgconfig" = "xyes"; then
+   AC_DEFINE([HAVE_LIBELF], [1], [libelf library is present])
+else
+   AC_MSG_WARN(libelf library not available)
+fi
+
 AS_IF([test "x$x11_pkgconfig" = xyes],
       [PKG_CHECK_MODULES(GL, [gl], [gl_pkgconfig=yes], [gl_pkgconfig=no])], [gl_pkgconfig=no])
 AC_SUBST([GL_CFLAGS])
@@ -497,6 +507,7 @@ compile time options summary
     X11                        : $x11_pkgconfig
     GL                         : $gl_pkgconfig
     glu                        : $glu_pkgconfig
+    libelf		       : $libelf_pkgconfig
     libjpeg                    : $have_jpeg
     libudev                    : $have_libudev
     pthread                    : $have_pthread
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
new file mode 100644
index 00000000..64ac0f7a
--- /dev/null
+++ b/include/linux/bpf.h
@@ -0,0 +1,2644 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#ifndef _UAPI__LINUX_BPF_H__
+#define _UAPI__LINUX_BPF_H__
+
+#include <linux/types.h>
+#include <linux/bpf_common.h>
+
+/* Extended instruction set based on top of classic BPF */
+
+/* instruction classes */
+#define BPF_ALU64	0x07	/* alu mode in double word width */
+
+/* ld/ldx fields */
+#define BPF_DW		0x18	/* double word (64-bit) */
+#define BPF_XADD	0xc0	/* exclusive add */
+
+/* alu/jmp fields */
+#define BPF_MOV		0xb0	/* mov reg to reg */
+#define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */
+
+/* change endianness of a register */
+#define BPF_END		0xd0	/* flags for endianness conversion: */
+#define BPF_TO_LE	0x00	/* convert to little-endian */
+#define BPF_TO_BE	0x08	/* convert to big-endian */
+#define BPF_FROM_LE	BPF_TO_LE
+#define BPF_FROM_BE	BPF_TO_BE
+
+/* jmp encodings */
+#define BPF_JNE		0x50	/* jump != */
+#define BPF_JLT		0xa0	/* LT is unsigned, '<' */
+#define BPF_JLE		0xb0	/* LE is unsigned, '<=' */
+#define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
+#define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
+#define BPF_JSLT	0xc0	/* SLT is signed, '<' */
+#define BPF_JSLE	0xd0	/* SLE is signed, '<=' */
+#define BPF_CALL	0x80	/* function call */
+#define BPF_EXIT	0x90	/* function return */
+
+/* Register numbers */
+enum {
+	BPF_REG_0 = 0,
+	BPF_REG_1,
+	BPF_REG_2,
+	BPF_REG_3,
+	BPF_REG_4,
+	BPF_REG_5,
+	BPF_REG_6,
+	BPF_REG_7,
+	BPF_REG_8,
+	BPF_REG_9,
+	BPF_REG_10,
+	__MAX_BPF_REG,
+};
+
+/* BPF has 10 general purpose 64-bit registers and stack frame. */
+#define MAX_BPF_REG	__MAX_BPF_REG
+
+struct bpf_insn {
+	__u8	code;		/* opcode */
+	__u8	dst_reg:4;	/* dest register */
+	__u8	src_reg:4;	/* source register */
+	__s16	off;		/* signed offset */
+	__s32	imm;		/* signed immediate constant */
+};
+
+/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
+struct bpf_lpm_trie_key {
+	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
+	__u8	data[0];	/* Arbitrary size */
+};
+
+/* BPF syscall commands, see bpf(2) man-page for details. */
+enum bpf_cmd {
+	BPF_MAP_CREATE,
+	BPF_MAP_LOOKUP_ELEM,
+	BPF_MAP_UPDATE_ELEM,
+	BPF_MAP_DELETE_ELEM,
+	BPF_MAP_GET_NEXT_KEY,
+	BPF_PROG_LOAD,
+	BPF_OBJ_PIN,
+	BPF_OBJ_GET,
+	BPF_PROG_ATTACH,
+	BPF_PROG_DETACH,
+	BPF_PROG_TEST_RUN,
+	BPF_PROG_GET_NEXT_ID,
+	BPF_MAP_GET_NEXT_ID,
+	BPF_PROG_GET_FD_BY_ID,
+	BPF_MAP_GET_FD_BY_ID,
+	BPF_OBJ_GET_INFO_BY_FD,
+	BPF_PROG_QUERY,
+	BPF_RAW_TRACEPOINT_OPEN,
+	BPF_BTF_LOAD,
+	BPF_BTF_GET_FD_BY_ID,
+	BPF_TASK_FD_QUERY,
+};
+
+enum bpf_map_type {
+	BPF_MAP_TYPE_UNSPEC,
+	BPF_MAP_TYPE_HASH,
+	BPF_MAP_TYPE_ARRAY,
+	BPF_MAP_TYPE_PROG_ARRAY,
+	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
+	BPF_MAP_TYPE_PERCPU_HASH,
+	BPF_MAP_TYPE_PERCPU_ARRAY,
+	BPF_MAP_TYPE_STACK_TRACE,
+	BPF_MAP_TYPE_CGROUP_ARRAY,
+	BPF_MAP_TYPE_LRU_HASH,
+	BPF_MAP_TYPE_LRU_PERCPU_HASH,
+	BPF_MAP_TYPE_LPM_TRIE,
+	BPF_MAP_TYPE_ARRAY_OF_MAPS,
+	BPF_MAP_TYPE_HASH_OF_MAPS,
+	BPF_MAP_TYPE_DEVMAP,
+	BPF_MAP_TYPE_SOCKMAP,
+	BPF_MAP_TYPE_CPUMAP,
+	BPF_MAP_TYPE_XSKMAP,
+	BPF_MAP_TYPE_SOCKHASH,
+};
+
+enum bpf_prog_type {
+	BPF_PROG_TYPE_UNSPEC,
+	BPF_PROG_TYPE_SOCKET_FILTER,
+	BPF_PROG_TYPE_KPROBE,
+	BPF_PROG_TYPE_SCHED_CLS,
+	BPF_PROG_TYPE_SCHED_ACT,
+	BPF_PROG_TYPE_TRACEPOINT,
+	BPF_PROG_TYPE_XDP,
+	BPF_PROG_TYPE_PERF_EVENT,
+	BPF_PROG_TYPE_CGROUP_SKB,
+	BPF_PROG_TYPE_CGROUP_SOCK,
+	BPF_PROG_TYPE_LWT_IN,
+	BPF_PROG_TYPE_LWT_OUT,
+	BPF_PROG_TYPE_LWT_XMIT,
+	BPF_PROG_TYPE_SOCK_OPS,
+	BPF_PROG_TYPE_SK_SKB,
+	BPF_PROG_TYPE_CGROUP_DEVICE,
+	BPF_PROG_TYPE_SK_MSG,
+	BPF_PROG_TYPE_RAW_TRACEPOINT,
+	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+	BPF_PROG_TYPE_LWT_SEG6LOCAL,
+	BPF_PROG_TYPE_LIRC_MODE2,
+};
+
+enum bpf_attach_type {
+	BPF_CGROUP_INET_INGRESS,
+	BPF_CGROUP_INET_EGRESS,
+	BPF_CGROUP_INET_SOCK_CREATE,
+	BPF_CGROUP_SOCK_OPS,
+	BPF_SK_SKB_STREAM_PARSER,
+	BPF_SK_SKB_STREAM_VERDICT,
+	BPF_CGROUP_DEVICE,
+	BPF_SK_MSG_VERDICT,
+	BPF_CGROUP_INET4_BIND,
+	BPF_CGROUP_INET6_BIND,
+	BPF_CGROUP_INET4_CONNECT,
+	BPF_CGROUP_INET6_CONNECT,
+	BPF_CGROUP_INET4_POST_BIND,
+	BPF_CGROUP_INET6_POST_BIND,
+	BPF_CGROUP_UDP4_SENDMSG,
+	BPF_CGROUP_UDP6_SENDMSG,
+	BPF_LIRC_MODE2,
+	__MAX_BPF_ATTACH_TYPE
+};
+
+#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
+
+/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
+ *
+ * NONE(default): No further bpf programs allowed in the subtree.
+ *
+ * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
+ * the program in this cgroup yields to sub-cgroup program.
+ *
+ * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
+ * that cgroup program gets run in addition to the program in this cgroup.
+ *
+ * Only one program is allowed to be attached to a cgroup with
+ * NONE or BPF_F_ALLOW_OVERRIDE flag.
+ * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
+ * release old program and attach the new one. Attach flags has to match.
+ *
+ * Multiple programs are allowed to be attached to a cgroup with
+ * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
+ * (those that were attached first, run first)
+ * The programs of sub-cgroup are executed first, then programs of
+ * this cgroup and then programs of parent cgroup.
+ * When children program makes decision (like picking TCP CA or sock bind)
+ * parent program has a chance to override it.
+ *
+ * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
+ * A cgroup with NONE doesn't allow any programs in sub-cgroups.
+ * Ex1:
+ * cgrp1 (MULTI progs A, B) ->
+ *    cgrp2 (OVERRIDE prog C) ->
+ *      cgrp3 (MULTI prog D) ->
+ *        cgrp4 (OVERRIDE prog E) ->
+ *          cgrp5 (NONE prog F)
+ * the event in cgrp5 triggers execution of F,D,A,B in that order.
+ * if prog F is detached, the execution is E,D,A,B
+ * if prog F and D are detached, the execution is E,A,B
+ * if prog F, E and D are detached, the execution is C,A,B
+ *
+ * All eligible programs are executed regardless of return code from
+ * earlier programs.
+ */
+#define BPF_F_ALLOW_OVERRIDE	(1U << 0)
+#define BPF_F_ALLOW_MULTI	(1U << 1)
+
+/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
+ * verifier will perform strict alignment checking as if the kernel
+ * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
+ * and NET_IP_ALIGN defined to 2.
+ */
+#define BPF_F_STRICT_ALIGNMENT	(1U << 0)
+
+/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
+#define BPF_PSEUDO_MAP_FD	1
+
+/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
+ * offset to another bpf function
+ */
+#define BPF_PSEUDO_CALL		1
+
+/* flags for BPF_MAP_UPDATE_ELEM command */
+#define BPF_ANY		0 /* create new element or update existing */
+#define BPF_NOEXIST	1 /* create new element if it didn't exist */
+#define BPF_EXIST	2 /* update existing element */
+
+/* flags for BPF_MAP_CREATE command */
+#define BPF_F_NO_PREALLOC	(1U << 0)
+/* Instead of having one common LRU list in the
+ * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
+ * which can scale and perform better.
+ * Note, the LRU nodes (including free nodes) cannot be moved
+ * across different LRU lists.
+ */
+#define BPF_F_NO_COMMON_LRU	(1U << 1)
+/* Specify numa node during map creation */
+#define BPF_F_NUMA_NODE		(1U << 2)
+
+/* flags for BPF_PROG_QUERY */
+#define BPF_F_QUERY_EFFECTIVE	(1U << 0)
+
+#define BPF_OBJ_NAME_LEN 16U
+
+/* Flags for accessing BPF object */
+#define BPF_F_RDONLY		(1U << 3)
+#define BPF_F_WRONLY		(1U << 4)
+
+/* Flag for stack_map, store build_id+offset instead of pointer */
+#define BPF_F_STACK_BUILD_ID	(1U << 5)
+
+enum bpf_stack_build_id_status {
+	/* user space need an empty entry to identify end of a trace */
+	BPF_STACK_BUILD_ID_EMPTY = 0,
+	/* with valid build_id and offset */
+	BPF_STACK_BUILD_ID_VALID = 1,
+	/* couldn't get build_id, fallback to ip */
+	BPF_STACK_BUILD_ID_IP = 2,
+};
+
+#define BPF_BUILD_ID_SIZE 20
+struct bpf_stack_build_id {
+	__s32		status;
+	unsigned char	build_id[BPF_BUILD_ID_SIZE];
+	union {
+		__u64	offset;
+		__u64	ip;
+	};
+};
+
+union bpf_attr {
+	struct { /* anonymous struct used by BPF_MAP_CREATE command */
+		__u32	map_type;	/* one of enum bpf_map_type */
+		__u32	key_size;	/* size of key in bytes */
+		__u32	value_size;	/* size of value in bytes */
+		__u32	max_entries;	/* max number of entries in a map */
+		__u32	map_flags;	/* BPF_MAP_CREATE related
+					 * flags defined above.
+					 */
+		__u32	inner_map_fd;	/* fd pointing to the inner map */
+		__u32	numa_node;	/* numa node (effective only if
+					 * BPF_F_NUMA_NODE is set).
+					 */
+		char	map_name[BPF_OBJ_NAME_LEN];
+		__u32	map_ifindex;	/* ifindex of netdev to create on */
+		__u32	btf_fd;		/* fd pointing to a BTF type data */
+		__u32	btf_key_type_id;	/* BTF type_id of the key */
+		__u32	btf_value_type_id;	/* BTF type_id of the value */
+	};
+
+	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
+		__u32		map_fd;
+		__aligned_u64	key;
+		union {
+			__aligned_u64 value;
+			__aligned_u64 next_key;
+		};
+		__u64		flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_LOAD command */
+		__u32		prog_type;	/* one of enum bpf_prog_type */
+		__u32		insn_cnt;
+		__aligned_u64	insns;
+		__aligned_u64	license;
+		__u32		log_level;	/* verbosity level of verifier */
+		__u32		log_size;	/* size of user buffer */
+		__aligned_u64	log_buf;	/* user supplied buffer */
+		__u32		kern_version;	/* checked when prog_type=kprobe */
+		__u32		prog_flags;
+		char		prog_name[BPF_OBJ_NAME_LEN];
+		__u32		prog_ifindex;	/* ifindex of netdev to prep for */
+		/* For some prog types expected attach type must be known at
+		 * load time to verify attach type specific parts of prog
+		 * (context accesses, allowed helpers, etc).
+		 */
+		__u32		expected_attach_type;
+	};
+
+	struct { /* anonymous struct used by BPF_OBJ_* commands */
+		__aligned_u64	pathname;
+		__u32		bpf_fd;
+		__u32		file_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
+		__u32		target_fd;	/* container object to attach to */
+		__u32		attach_bpf_fd;	/* eBPF program to attach */
+		__u32		attach_type;
+		__u32		attach_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
+		__u32		prog_fd;
+		__u32		retval;
+		__u32		data_size_in;
+		__u32		data_size_out;
+		__aligned_u64	data_in;
+		__aligned_u64	data_out;
+		__u32		repeat;
+		__u32		duration;
+	} test;
+
+	struct { /* anonymous struct used by BPF_*_GET_*_ID */
+		union {
+			__u32		start_id;
+			__u32		prog_id;
+			__u32		map_id;
+			__u32		btf_id;
+		};
+		__u32		next_id;
+		__u32		open_flags;
+	};
+
+	struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
+		__u32		bpf_fd;
+		__u32		info_len;
+		__aligned_u64	info;
+	} info;
+
+	struct { /* anonymous struct used by BPF_PROG_QUERY command */
+		__u32		target_fd;	/* container object to query */
+		__u32		attach_type;
+		__u32		query_flags;
+		__u32		attach_flags;
+		__aligned_u64	prog_ids;
+		__u32		prog_cnt;
+	} query;
+
+	struct {
+		__u64 name;
+		__u32 prog_fd;
+	} raw_tracepoint;
+
+	struct { /* anonymous struct for BPF_BTF_LOAD */
+		__aligned_u64	btf;
+		__aligned_u64	btf_log_buf;
+		__u32		btf_size;
+		__u32		btf_log_size;
+		__u32		btf_log_level;
+	};
+
+	struct {
+		__u32		pid;		/* input: pid */
+		__u32		fd;		/* input: fd */
+		__u32		flags;		/* input: flags */
+		__u32		buf_len;	/* input/output: buf len */
+		__aligned_u64	buf;		/* input/output:
+						 *   tp_name for tracepoint
+						 *   symbol for kprobe
+						 *   filename for uprobe
+						 */
+		__u32		prog_id;	/* output: prod_id */
+		__u32		fd_type;	/* output: BPF_FD_TYPE_* */
+		__u64		probe_offset;	/* output: probe_offset */
+		__u64		probe_addr;	/* output: probe_addr */
+	} task_fd_query;
+} __attribute__((aligned(8)));
+
+/* The description below is an attempt at providing documentation to eBPF
+ * developers about the multiple available eBPF helper functions. It can be
+ * parsed and used to produce a manual page. The workflow is the following,
+ * and requires the rst2man utility:
+ *
+ *     $ ./scripts/bpf_helpers_doc.py \
+ *             --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
+ *     $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
+ *     $ man /tmp/bpf-helpers.7
+ *
+ * Note that in order to produce this external documentation, some RST
+ * formatting is used in the descriptions to get "bold" and "italics" in
+ * manual pages. Also note that the few trailing white spaces are
+ * intentional, removing them would break paragraphs for rst2man.
+ *
+ * Start of BPF helper function descriptions:
+ *
+ * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
+ * 	Description
+ * 		Perform a lookup in *map* for an entry associated to *key*.
+ * 	Return
+ * 		Map value associated to *key*, or **NULL** if no entry was
+ * 		found.
+ *
+ * int bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
+ * 	Description
+ * 		Add or update the value of the entry associated to *key* in
+ * 		*map* with *value*. *flags* is one of:
+ *
+ * 		**BPF_NOEXIST**
+ * 			The entry for *key* must not exist in the map.
+ * 		**BPF_EXIST**
+ * 			The entry for *key* must already exist in the map.
+ * 		**BPF_ANY**
+ * 			No condition on the existence of the entry for *key*.
+ *
+ * 		Flag value **BPF_NOEXIST** cannot be used for maps of types
+ * 		**BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY**  (all
+ * 		elements always exist), the helper would return an error.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_delete_elem(struct bpf_map *map, const void *key)
+ * 	Description
+ * 		Delete entry with *key* from *map*.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_probe_read(void *dst, u32 size, const void *src)
+ * 	Description
+ * 		For tracing programs, safely attempt to read *size* bytes from
+ * 		address *src* and store the data in *dst*.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_ktime_get_ns(void)
+ * 	Description
+ * 		Return the time elapsed since system boot, in nanoseconds.
+ * 	Return
+ * 		Current *ktime*.
+ *
+ * int bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
+ * 	Description
+ * 		This helper is a "printk()-like" facility for debugging. It
+ * 		prints a message defined by format *fmt* (of size *fmt_size*)
+ * 		to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
+ * 		available. It can take up to three additional **u64**
+ * 		arguments (as an eBPF helpers, the total number of arguments is
+ * 		limited to five).
+ *
+ * 		Each time the helper is called, it appends a line to the trace.
+ * 		The format of the trace is customizable, and the exact output
+ * 		one will get depends on the options set in
+ * 		*\/sys/kernel/debug/tracing/trace_options* (see also the
+ * 		*README* file under the same directory). However, it usually
+ * 		defaults to something like:
+ *
+ * 		::
+ *
+ * 			telnet-470   [001] .N.. 419421.045894: 0x00000001: <formatted msg>
+ *
+ * 		In the above:
+ *
+ * 			* ``telnet`` is the name of the current task.
+ * 			* ``470`` is the PID of the current task.
+ * 			* ``001`` is the CPU number on which the task is
+ * 			  running.
+ * 			* In ``.N..``, each character refers to a set of
+ * 			  options (whether irqs are enabled, scheduling
+ * 			  options, whether hard/softirqs are running, level of
+ * 			  preempt_disabled respectively). **N** means that
+ * 			  **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
+ * 			  are set.
+ * 			* ``419421.045894`` is a timestamp.
+ * 			* ``0x00000001`` is a fake value used by BPF for the
+ * 			  instruction pointer register.
+ * 			* ``<formatted msg>`` is the message formatted with
+ * 			  *fmt*.
+ *
+ * 		The conversion specifiers supported by *fmt* are similar, but
+ * 		more limited than for printk(). They are **%d**, **%i**,
+ * 		**%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
+ * 		**%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
+ * 		of field, padding with zeroes, etc.) is available, and the
+ * 		helper will return **-EINVAL** (but print nothing) if it
+ * 		encounters an unknown specifier.
+ *
+ * 		Also, note that **bpf_trace_printk**\ () is slow, and should
+ * 		only be used for debugging purposes. For this reason, a notice
+ * 		bloc (spanning several lines) is printed to kernel logs and
+ * 		states that the helper should not be used "for production use"
+ * 		the first time this helper is used (or more precisely, when
+ * 		**trace_printk**\ () buffers are allocated). For passing values
+ * 		to user space, perf events should be preferred.
+ * 	Return
+ * 		The number of bytes written to the buffer, or a negative error
+ * 		in case of failure.
+ *
+ * u32 bpf_get_prandom_u32(void)
+ * 	Description
+ * 		Get a pseudo-random number.
+ *
+ * 		From a security point of view, this helper uses its own
+ * 		pseudo-random internal state, and cannot be used to infer the
+ * 		seed of other random functions in the kernel. However, it is
+ * 		essential to note that the generator used by the helper is not
+ * 		cryptographically secure.
+ * 	Return
+ * 		A random 32-bit unsigned value.
+ *
+ * u32 bpf_get_smp_processor_id(void)
+ * 	Description
+ * 		Get the SMP (symmetric multiprocessing) processor id. Note that
+ * 		all programs run with preemption disabled, which means that the
+ * 		SMP processor id is stable during all the execution of the
+ * 		program.
+ * 	Return
+ * 		The SMP id of the processor running the program.
+ *
+ * int bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
+ * 	Description
+ * 		Store *len* bytes from address *from* into the packet
+ * 		associated to *skb*, at *offset*. *flags* are a combination of
+ * 		**BPF_F_RECOMPUTE_CSUM** (automatically recompute the
+ * 		checksum for the packet after storing the bytes) and
+ * 		**BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
+ * 		**->swhash** and *skb*\ **->l4hash** to 0).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
+ * 	Description
+ * 		Recompute the layer 3 (e.g. IP) checksum for the packet
+ * 		associated to *skb*. Computation is incremental, so the helper
+ * 		must know the former value of the header field that was
+ * 		modified (*from*), the new value of this field (*to*), and the
+ * 		number of bytes (2 or 4) for this field, stored in *size*.
+ * 		Alternatively, it is possible to store the difference between
+ * 		the previous and the new values of the header field in *to*, by
+ * 		setting *from* and *size* to 0. For both methods, *offset*
+ * 		indicates the location of the IP checksum within the packet.
+ *
+ * 		This helper works in combination with **bpf_csum_diff**\ (),
+ * 		which does not update the checksum in-place, but offers more
+ * 		flexibility and can handle sizes larger than 2 or 4 for the
+ * 		checksum to update.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
+ * 	Description
+ * 		Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
+ * 		packet associated to *skb*. Computation is incremental, so the
+ * 		helper must know the former value of the header field that was
+ * 		modified (*from*), the new value of this field (*to*), and the
+ * 		number of bytes (2 or 4) for this field, stored on the lowest
+ * 		four bits of *flags*. Alternatively, it is possible to store
+ * 		the difference between the previous and the new values of the
+ * 		header field in *to*, by setting *from* and the four lowest
+ * 		bits of *flags* to 0. For both methods, *offset* indicates the
+ * 		location of the IP checksum within the packet. In addition to
+ * 		the size of the field, *flags* can be added (bitwise OR) actual
+ * 		flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
+ * 		untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
+ * 		for updates resulting in a null checksum the value is set to
+ * 		**CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
+ * 		the checksum is to be computed against a pseudo-header.
+ *
+ * 		This helper works in combination with **bpf_csum_diff**\ (),
+ * 		which does not update the checksum in-place, but offers more
+ * 		flexibility and can handle sizes larger than 2 or 4 for the
+ * 		checksum to update.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
+ * 	Description
+ * 		This special helper is used to trigger a "tail call", or in
+ * 		other words, to jump into another eBPF program. The same stack
+ * 		frame is used (but values on stack and in registers for the
+ * 		caller are not accessible to the callee). This mechanism allows
+ * 		for program chaining, either for raising the maximum number of
+ * 		available eBPF instructions, or to execute given programs in
+ * 		conditional blocks. For security reasons, there is an upper
+ * 		limit to the number of successive tail calls that can be
+ * 		performed.
+ *
+ * 		Upon call of this helper, the program attempts to jump into a
+ * 		program referenced at index *index* in *prog_array_map*, a
+ * 		special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
+ * 		*ctx*, a pointer to the context.
+ *
+ * 		If the call succeeds, the kernel immediately runs the first
+ * 		instruction of the new program. This is not a function call,
+ * 		and it never returns to the previous program. If the call
+ * 		fails, then the helper has no effect, and the caller continues
+ * 		to run its subsequent instructions. A call can fail if the
+ * 		destination program for the jump does not exist (i.e. *index*
+ * 		is superior to the number of entries in *prog_array_map*), or
+ * 		if the maximum number of tail calls has been reached for this
+ * 		chain of programs. This limit is defined in the kernel by the
+ * 		macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
+ * 		which is currently set to 32.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
+ * 	Description
+ * 		Clone and redirect the packet associated to *skb* to another
+ * 		net device of index *ifindex*. Both ingress and egress
+ * 		interfaces can be used for redirection. The **BPF_F_INGRESS**
+ * 		value in *flags* is used to make the distinction (ingress path
+ * 		is selected if the flag is present, egress path otherwise).
+ * 		This is the only flag supported for now.
+ *
+ * 		In comparison with **bpf_redirect**\ () helper,
+ * 		**bpf_clone_redirect**\ () has the associated cost of
+ * 		duplicating the packet buffer, but this can be executed out of
+ * 		the eBPF program. Conversely, **bpf_redirect**\ () is more
+ * 		efficient, but it is handled through an action code where the
+ * 		redirection happens only after the eBPF program has returned.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_get_current_pid_tgid(void)
+ * 	Return
+ * 		A 64-bit integer containing the current tgid and pid, and
+ * 		created as such:
+ * 		*current_task*\ **->tgid << 32 \|**
+ * 		*current_task*\ **->pid**.
+ *
+ * u64 bpf_get_current_uid_gid(void)
+ * 	Return
+ * 		A 64-bit integer containing the current GID and UID, and
+ * 		created as such: *current_gid* **<< 32 \|** *current_uid*.
+ *
+ * int bpf_get_current_comm(char *buf, u32 size_of_buf)
+ * 	Description
+ * 		Copy the **comm** attribute of the current task into *buf* of
+ * 		*size_of_buf*. The **comm** attribute contains the name of
+ * 		the executable (excluding the path) for the current task. The
+ * 		*size_of_buf* must be strictly positive. On success, the
+ * 		helper makes sure that the *buf* is NUL-terminated. On failure,
+ * 		it is filled with zeroes.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u32 bpf_get_cgroup_classid(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the classid for the current task, i.e. for the net_cls
+ * 		cgroup to which *skb* belongs.
+ *
+ * 		This helper can be used on TC egress path, but not on ingress.
+ *
+ * 		The net_cls cgroup provides an interface to tag network packets
+ * 		based on a user-provided identifier for all traffic coming from
+ * 		the tasks belonging to the related cgroup. See also the related
+ * 		kernel documentation, available from the Linux sources in file
+ * 		*Documentation/cgroup-v1/net_cls.txt*.
+ *
+ * 		The Linux kernel has two versions for cgroups: there are
+ * 		cgroups v1 and cgroups v2. Both are available to users, who can
+ * 		use a mixture of them, but note that the net_cls cgroup is for
+ * 		cgroup v1 only. This makes it incompatible with BPF programs
+ * 		run on cgroups, which is a cgroup-v2-only feature (a socket can
+ * 		only hold data for one version of cgroups at a time).
+ *
+ * 		This helper is only available is the kernel was compiled with
+ * 		the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
+ * 		"**y**" or to "**m**".
+ * 	Return
+ * 		The classid, or 0 for the default unconfigured classid.
+ *
+ * int bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
+ * 	Description
+ * 		Push a *vlan_tci* (VLAN tag control information) of protocol
+ * 		*vlan_proto* to the packet associated to *skb*, then update
+ * 		the checksum. Note that if *vlan_proto* is different from
+ * 		**ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
+ * 		be **ETH_P_8021Q**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_vlan_pop(struct sk_buff *skb)
+ * 	Description
+ * 		Pop a VLAN header from the packet associated to *skb*.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
+ * 	Description
+ * 		Get tunnel metadata. This helper takes a pointer *key* to an
+ * 		empty **struct bpf_tunnel_key** of **size**, that will be
+ * 		filled with tunnel metadata for the packet associated to *skb*.
+ * 		The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
+ * 		indicates that the tunnel is based on IPv6 protocol instead of
+ * 		IPv4.
+ *
+ * 		The **struct bpf_tunnel_key** is an object that generalizes the
+ * 		principal parameters used by various tunneling protocols into a
+ * 		single struct. This way, it can be used to easily make a
+ * 		decision based on the contents of the encapsulation header,
+ * 		"summarized" in this struct. In particular, it holds the IP
+ * 		address of the remote end (IPv4 or IPv6, depending on the case)
+ * 		in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
+ * 		this struct exposes the *key*\ **->tunnel_id**, which is
+ * 		generally mapped to a VNI (Virtual Network Identifier), making
+ * 		it programmable together with the **bpf_skb_set_tunnel_key**\
+ * 		() helper.
+ *
+ * 		Let's imagine that the following code is part of a program
+ * 		attached to the TC ingress interface, on one end of a GRE
+ * 		tunnel, and is supposed to filter out all messages coming from
+ * 		remote ends with IPv4 address other than 10.0.0.1:
+ *
+ * 		::
+ *
+ * 			int ret;
+ * 			struct bpf_tunnel_key key = {};
+ * 			
+ * 			ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+ * 			if (ret < 0)
+ * 				return TC_ACT_SHOT;	// drop packet
+ * 			
+ * 			if (key.remote_ipv4 != 0x0a000001)
+ * 				return TC_ACT_SHOT;	// drop packet
+ * 			
+ * 			return TC_ACT_OK;		// accept packet
+ *
+ * 		This interface can also be used with all encapsulation devices
+ * 		that can operate in "collect metadata" mode: instead of having
+ * 		one network device per specific configuration, the "collect
+ * 		metadata" mode only requires a single device where the
+ * 		configuration can be extracted from this helper.
+ *
+ * 		This can be used together with various tunnels such as VXLan,
+ * 		Geneve, GRE or IP in IP (IPIP).
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
+ * 	Description
+ * 		Populate tunnel metadata for packet associated to *skb.* The
+ * 		tunnel metadata is set to the contents of *key*, of *size*. The
+ * 		*flags* can be set to a combination of the following values:
+ *
+ * 		**BPF_F_TUNINFO_IPV6**
+ * 			Indicate that the tunnel is based on IPv6 protocol
+ * 			instead of IPv4.
+ * 		**BPF_F_ZERO_CSUM_TX**
+ * 			For IPv4 packets, add a flag to tunnel metadata
+ * 			indicating that checksum computation should be skipped
+ * 			and checksum set to zeroes.
+ * 		**BPF_F_DONT_FRAGMENT**
+ * 			Add a flag to tunnel metadata indicating that the
+ * 			packet should not be fragmented.
+ * 		**BPF_F_SEQ_NUMBER**
+ * 			Add a flag to tunnel metadata indicating that a
+ * 			sequence number should be added to tunnel header before
+ * 			sending the packet. This flag was added for GRE
+ * 			encapsulation, but might be used with other protocols
+ * 			as well in the future.
+ *
+ * 		Here is a typical usage on the transmit path:
+ *
+ * 		::
+ *
+ * 			struct bpf_tunnel_key key;
+ * 			     populate key ...
+ * 			bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
+ * 			bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
+ *
+ * 		See also the description of the **bpf_skb_get_tunnel_key**\ ()
+ * 		helper for additional information.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
+ * 	Description
+ * 		Read the value of a perf event counter. This helper relies on a
+ * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
+ * 		the perf event counter is selected when *map* is updated with
+ * 		perf event file descriptors. The *map* is an array whose size
+ * 		is the number of available CPUs, and each cell contains a value
+ * 		relative to one CPU. The value to retrieve is indicated by
+ * 		*flags*, that contains the index of the CPU to look up, masked
+ * 		with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
+ * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
+ * 		current CPU should be retrieved.
+ *
+ * 		Note that before Linux 4.13, only hardware perf event can be
+ * 		retrieved.
+ *
+ * 		Also, be aware that the newer helper
+ * 		**bpf_perf_event_read_value**\ () is recommended over
+ * 		**bpf_perf_event_read**\ () in general. The latter has some ABI
+ * 		quirks where error and counter value are used as a return code
+ * 		(which is wrong to do since ranges may overlap). This issue is
+ * 		fixed with **bpf_perf_event_read_value**\ (), which at the same
+ * 		time provides more features over the **bpf_perf_event_read**\
+ * 		() interface. Please refer to the description of
+ * 		**bpf_perf_event_read_value**\ () for details.
+ * 	Return
+ * 		The value of the perf event counter read from the map, or a
+ * 		negative error code in case of failure.
+ *
+ * int bpf_redirect(u32 ifindex, u64 flags)
+ * 	Description
+ * 		Redirect the packet to another net device of index *ifindex*.
+ * 		This helper is somewhat similar to **bpf_clone_redirect**\
+ * 		(), except that the packet is not cloned, which provides
+ * 		increased performance.
+ *
+ * 		Except for XDP, both ingress and egress interfaces can be used
+ * 		for redirection. The **BPF_F_INGRESS** value in *flags* is used
+ * 		to make the distinction (ingress path is selected if the flag
+ * 		is present, egress path otherwise). Currently, XDP only
+ * 		supports redirection to the egress interface, and accepts no
+ * 		flag at all.
+ *
+ * 		The same effect can be attained with the more generic
+ * 		**bpf_redirect_map**\ (), which requires specific maps to be
+ * 		used but offers better performance.
+ * 	Return
+ * 		For XDP, the helper returns **XDP_REDIRECT** on success or
+ * 		**XDP_ABORTED** on error. For other program types, the values
+ * 		are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
+ * 		error.
+ *
+ * u32 bpf_get_route_realm(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the realm or the route, that is to say the
+ * 		**tclassid** field of the destination for the *skb*. The
+ * 		indentifier retrieved is a user-provided tag, similar to the
+ * 		one used with the net_cls cgroup (see description for
+ * 		**bpf_get_cgroup_classid**\ () helper), but here this tag is
+ * 		held by a route (a destination entry), not by a task.
+ *
+ * 		Retrieving this identifier works with the clsact TC egress hook
+ * 		(see also **tc-bpf(8)**), or alternatively on conventional
+ * 		classful egress qdiscs, but not on TC ingress path. In case of
+ * 		clsact TC egress hook, this has the advantage that, internally,
+ * 		the destination entry has not been dropped yet in the transmit
+ * 		path. Therefore, the destination entry does not need to be
+ * 		artificially held via **netif_keep_dst**\ () for a classful
+ * 		qdisc until the *skb* is freed.
+ *
+ * 		This helper is available only if the kernel was compiled with
+ * 		**CONFIG_IP_ROUTE_CLASSID** configuration option.
+ * 	Return
+ * 		The realm of the route for the packet associated to *skb*, or 0
+ * 		if none was found.
+ *
+ * int bpf_perf_event_output(struct pt_reg *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
+ * 	Description
+ * 		Write raw *data* blob into a special BPF perf event held by
+ * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
+ * 		event must have the following attributes: **PERF_SAMPLE_RAW**
+ * 		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
+ * 		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
+ *
+ * 		The *flags* are used to indicate the index in *map* for which
+ * 		the value must be put, masked with **BPF_F_INDEX_MASK**.
+ * 		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
+ * 		to indicate that the index of the current CPU core should be
+ * 		used.
+ *
+ * 		The value to write, of *size*, is passed through eBPF stack and
+ * 		pointed by *data*.
+ *
+ * 		The context of the program *ctx* needs also be passed to the
+ * 		helper.
+ *
+ * 		On user space, a program willing to read the values needs to
+ * 		call **perf_event_open**\ () on the perf event (either for
+ * 		one or for all CPUs) and to store the file descriptor into the
+ * 		*map*. This must be done before the eBPF program can send data
+ * 		into it. An example is available in file
+ * 		*samples/bpf/trace_output_user.c* in the Linux kernel source
+ * 		tree (the eBPF program counterpart is in
+ * 		*samples/bpf/trace_output_kern.c*).
+ *
+ * 		**bpf_perf_event_output**\ () achieves better performance
+ * 		than **bpf_trace_printk**\ () for sharing data with user
+ * 		space, and is much better suitable for streaming data from eBPF
+ * 		programs.
+ *
+ * 		Note that this helper is not restricted to tracing use cases
+ * 		and can be used with programs attached to TC or XDP as well,
+ * 		where it allows for passing data to user space listeners. Data
+ * 		can be:
+ *
+ * 		* Only custom structs,
+ * 		* Only the packet payload, or
+ * 		* A combination of both.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len)
+ * 	Description
+ * 		This helper was provided as an easy way to load data from a
+ * 		packet. It can be used to load *len* bytes from *offset* from
+ * 		the packet associated to *skb*, into the buffer pointed by
+ * 		*to*.
+ *
+ * 		Since Linux 4.7, usage of this helper has mostly been replaced
+ * 		by "direct packet access", enabling packet data to be
+ * 		manipulated with *skb*\ **->data** and *skb*\ **->data_end**
+ * 		pointing respectively to the first byte of packet data and to
+ * 		the byte after the last byte of packet data. However, it
+ * 		remains useful if one wishes to read large quantities of data
+ * 		at once from a packet into the eBPF stack.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_stackid(struct pt_reg *ctx, struct bpf_map *map, u64 flags)
+ * 	Description
+ * 		Walk a user or a kernel stack and return its id. To achieve
+ * 		this, the helper needs *ctx*, which is a pointer to the context
+ * 		on which the tracing program is executed, and a pointer to a
+ * 		*map* of type **BPF_MAP_TYPE_STACK_TRACE**.
+ *
+ * 		The last argument, *flags*, holds the number of stack frames to
+ * 		skip (from 0 to 255), masked with
+ * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
+ * 		a combination of the following flags:
+ *
+ * 		**BPF_F_USER_STACK**
+ * 			Collect a user space stack instead of a kernel stack.
+ * 		**BPF_F_FAST_STACK_CMP**
+ * 			Compare stacks by hash only.
+ * 		**BPF_F_REUSE_STACKID**
+ * 			If two different stacks hash into the same *stackid*,
+ * 			discard the old one.
+ *
+ * 		The stack id retrieved is a 32 bit long integer handle which
+ * 		can be further combined with other data (including other stack
+ * 		ids) and used as a key into maps. This can be useful for
+ * 		generating a variety of graphs (such as flame graphs or off-cpu
+ * 		graphs).
+ *
+ * 		For walking a stack, this helper is an improvement over
+ * 		**bpf_probe_read**\ (), which can be used with unrolled loops
+ * 		but is not efficient and consumes a lot of eBPF instructions.
+ * 		Instead, **bpf_get_stackid**\ () can collect up to
+ * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
+ * 		this limit can be controlled with the **sysctl** program, and
+ * 		that it should be manually increased in order to profile long
+ * 		user stacks (such as stacks for Java programs). To do so, use:
+ *
+ * 		::
+ *
+ * 			# sysctl kernel.perf_event_max_stack=<new value>
+ * 	Return
+ * 		The positive or null stack id on success, or a negative error
+ * 		in case of failure.
+ *
+ * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
+ * 	Description
+ * 		Compute a checksum difference, from the raw buffer pointed by
+ * 		*from*, of length *from_size* (that must be a multiple of 4),
+ * 		towards the raw buffer pointed by *to*, of size *to_size*
+ * 		(same remark). An optional *seed* can be added to the value
+ * 		(this can be cascaded, the seed may come from a previous call
+ * 		to the helper).
+ *
+ * 		This is flexible enough to be used in several ways:
+ *
+ * 		* With *from_size* == 0, *to_size* > 0 and *seed* set to
+ * 		  checksum, it can be used when pushing new data.
+ * 		* With *from_size* > 0, *to_size* == 0 and *seed* set to
+ * 		  checksum, it can be used when removing data from a packet.
+ * 		* With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
+ * 		  can be used to compute a diff. Note that *from_size* and
+ * 		  *to_size* do not need to be equal.
+ *
+ * 		This helper can be used in combination with
+ * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
+ * 		which one can feed in the difference computed with
+ * 		**bpf_csum_diff**\ ().
+ * 	Return
+ * 		The checksum result, or a negative error code in case of
+ * 		failure.
+ *
+ * int bpf_skb_get_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
+ * 	Description
+ * 		Retrieve tunnel options metadata for the packet associated to
+ * 		*skb*, and store the raw tunnel option data to the buffer *opt*
+ * 		of *size*.
+ *
+ * 		This helper can be used with encapsulation devices that can
+ * 		operate in "collect metadata" mode (please refer to the related
+ * 		note in the description of **bpf_skb_get_tunnel_key**\ () for
+ * 		more details). A particular example where this can be used is
+ * 		in combination with the Geneve encapsulation protocol, where it
+ * 		allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
+ * 		and retrieving arbitrary TLVs (Type-Length-Value headers) from
+ * 		the eBPF program. This allows for full customization of these
+ * 		headers.
+ * 	Return
+ * 		The size of the option data retrieved.
+ *
+ * int bpf_skb_set_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
+ * 	Description
+ * 		Set tunnel options metadata for the packet associated to *skb*
+ * 		to the option data contained in the raw buffer *opt* of *size*.
+ *
+ * 		See also the description of the **bpf_skb_get_tunnel_opt**\ ()
+ * 		helper for additional information.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
+ * 	Description
+ * 		Change the protocol of the *skb* to *proto*. Currently
+ * 		supported are transition from IPv4 to IPv6, and from IPv6 to
+ * 		IPv4. The helper takes care of the groundwork for the
+ * 		transition, including resizing the socket buffer. The eBPF
+ * 		program is expected to fill the new headers, if any, via
+ * 		**skb_store_bytes**\ () and to recompute the checksums with
+ * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
+ * 		(). The main case for this helper is to perform NAT64
+ * 		operations out of an eBPF program.
+ *
+ * 		Internally, the GSO type is marked as dodgy so that headers are
+ * 		checked and segments are recalculated by the GSO/GRO engine.
+ * 		The size for GSO target is adapted as well.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_change_type(struct sk_buff *skb, u32 type)
+ * 	Description
+ * 		Change the packet type for the packet associated to *skb*. This
+ * 		comes down to setting *skb*\ **->pkt_type** to *type*, except
+ * 		the eBPF program does not have a write access to *skb*\
+ * 		**->pkt_type** beside this helper. Using a helper here allows
+ * 		for graceful handling of errors.
+ *
+ * 		The major use case is to change incoming *skb*s to
+ * 		**PACKET_HOST** in a programmatic way instead of having to
+ * 		recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
+ * 		example.
+ *
+ * 		Note that *type* only allows certain values. At this time, they
+ * 		are:
+ *
+ * 		**PACKET_HOST**
+ * 			Packet is for us.
+ * 		**PACKET_BROADCAST**
+ * 			Send packet to all.
+ * 		**PACKET_MULTICAST**
+ * 			Send packet to group.
+ * 		**PACKET_OTHERHOST**
+ * 			Send packet to someone else.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
+ * 	Description
+ * 		Check whether *skb* is a descendant of the cgroup2 held by
+ * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
+ * 	Return
+ * 		The return value depends on the result of the test, and can be:
+ *
+ * 		* 0, if the *skb* failed the cgroup2 descendant test.
+ * 		* 1, if the *skb* succeeded the cgroup2 descendant test.
+ * 		* A negative error code, if an error occurred.
+ *
+ * u32 bpf_get_hash_recalc(struct sk_buff *skb)
+ * 	Description
+ * 		Retrieve the hash of the packet, *skb*\ **->hash**. If it is
+ * 		not set, in particular if the hash was cleared due to mangling,
+ * 		recompute this hash. Later accesses to the hash can be done
+ * 		directly with *skb*\ **->hash**.
+ *
+ * 		Calling **bpf_set_hash_invalid**\ (), changing a packet
+ * 		prototype with **bpf_skb_change_proto**\ (), or calling
+ * 		**bpf_skb_store_bytes**\ () with the
+ * 		**BPF_F_INVALIDATE_HASH** are actions susceptible to clear
+ * 		the hash and to trigger a new computation for the next call to
+ * 		**bpf_get_hash_recalc**\ ().
+ * 	Return
+ * 		The 32-bit hash.
+ *
+ * u64 bpf_get_current_task(void)
+ * 	Return
+ * 		A pointer to the current task struct.
+ *
+ * int bpf_probe_write_user(void *dst, const void *src, u32 len)
+ * 	Description
+ * 		Attempt in a safe way to write *len* bytes from the buffer
+ * 		*src* to *dst* in memory. It only works for threads that are in
+ * 		user context, and *dst* must be a valid user space address.
+ *
+ * 		This helper should not be used to implement any kind of
+ * 		security mechanism because of TOC-TOU attacks, but rather to
+ * 		debug, divert, and manipulate execution of semi-cooperative
+ * 		processes.
+ *
+ * 		Keep in mind that this feature is meant for experiments, and it
+ * 		has a risk of crashing the system and running programs.
+ * 		Therefore, when an eBPF program using this helper is attached,
+ * 		a warning including PID and process name is printed to kernel
+ * 		logs.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
+ * 	Description
+ * 		Check whether the probe is being run is the context of a given
+ * 		subset of the cgroup2 hierarchy. The cgroup2 to test is held by
+ * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
+ * 	Return
+ * 		The return value depends on the result of the test, and can be:
+ *
+ * 		* 0, if the *skb* task belongs to the cgroup2.
+ * 		* 1, if the *skb* task does not belong to the cgroup2.
+ * 		* A negative error code, if an error occurred.
+ *
+ * int bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
+ * 	Description
+ * 		Resize (trim or grow) the packet associated to *skb* to the
+ * 		new *len*. The *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		The basic idea is that the helper performs the needed work to
+ * 		change the size of the packet, then the eBPF program rewrites
+ * 		the rest via helpers like **bpf_skb_store_bytes**\ (),
+ * 		**bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
+ * 		and others. This helper is a slow path utility intended for
+ * 		replies with control messages. And because it is targeted for
+ * 		slow path, the helper itself can afford to be slow: it
+ * 		implicitly linearizes, unclones and drops offloads from the
+ * 		*skb*.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_pull_data(struct sk_buff *skb, u32 len)
+ * 	Description
+ * 		Pull in non-linear data in case the *skb* is non-linear and not
+ * 		all of *len* are part of the linear section. Make *len* bytes
+ * 		from *skb* readable and writable. If a zero value is passed for
+ * 		*len*, then the whole length of the *skb* is pulled.
+ *
+ * 		This helper is only needed for reading and writing with direct
+ * 		packet access.
+ *
+ * 		For direct packet access, testing that offsets to access
+ * 		are within packet boundaries (test on *skb*\ **->data_end**) is
+ * 		susceptible to fail if offsets are invalid, or if the requested
+ * 		data is in non-linear parts of the *skb*. On failure the
+ * 		program can just bail out, or in the case of a non-linear
+ * 		buffer, use a helper to make the data available. The
+ * 		**bpf_skb_load_bytes**\ () helper is a first solution to access
+ * 		the data. Another one consists in using **bpf_skb_pull_data**
+ * 		to pull in once the non-linear parts, then retesting and
+ * 		eventually access the data.
+ *
+ * 		At the same time, this also makes sure the *skb* is uncloned,
+ * 		which is a necessary condition for direct write. As this needs
+ * 		to be an invariant for the write part only, the verifier
+ * 		detects writes and adds a prologue that is calling
+ * 		**bpf_skb_pull_data()** to effectively unclone the *skb* from
+ * 		the very beginning in case it is indeed cloned.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
+ * 	Description
+ * 		Add the checksum *csum* into *skb*\ **->csum** in case the
+ * 		driver has supplied a checksum for the entire packet into that
+ * 		field. Return an error otherwise. This helper is intended to be
+ * 		used in combination with **bpf_csum_diff**\ (), in particular
+ * 		when the checksum needs to be updated after data has been
+ * 		written into the packet through direct packet access.
+ * 	Return
+ * 		The checksum on success, or a negative error code in case of
+ * 		failure.
+ *
+ * void bpf_set_hash_invalid(struct sk_buff *skb)
+ * 	Description
+ * 		Invalidate the current *skb*\ **->hash**. It can be used after
+ * 		mangling on headers through direct packet access, in order to
+ * 		indicate that the hash is outdated and to trigger a
+ * 		recalculation the next time the kernel tries to access this
+ * 		hash or when the **bpf_get_hash_recalc**\ () helper is called.
+ *
+ * int bpf_get_numa_node_id(void)
+ * 	Description
+ * 		Return the id of the current NUMA node. The primary use case
+ * 		for this helper is the selection of sockets for the local NUMA
+ * 		node, when the program is attached to sockets using the
+ * 		**SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
+ * 		but the helper is also available to other eBPF program types,
+ * 		similarly to **bpf_get_smp_processor_id**\ ().
+ * 	Return
+ * 		The id of current NUMA node.
+ *
+ * int bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
+ * 	Description
+ * 		Grows headroom of packet associated to *skb* and adjusts the
+ * 		offset of the MAC header accordingly, adding *len* bytes of
+ * 		space. It automatically extends and reallocates memory as
+ * 		required.
+ *
+ * 		This helper can be used on a layer 3 *skb* to push a MAC header
+ * 		for redirection into a layer 2 device.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
+ * 		it is possible to use a negative value for *delta*. This helper
+ * 		can be used to prepare the packet for pushing or popping
+ * 		headers.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
+ * 	Description
+ * 		Copy a NUL terminated string from an unsafe address
+ * 		*unsafe_ptr* to *dst*. The *size* should include the
+ * 		terminating NUL byte. In case the string length is smaller than
+ * 		*size*, the target is not padded with further NUL bytes. If the
+ * 		string length is larger than *size*, just *size*-1 bytes are
+ * 		copied and the last byte is set to NUL.
+ *
+ * 		On success, the length of the copied string is returned. This
+ * 		makes this helper useful in tracing programs for reading
+ * 		strings, and more importantly to get its length at runtime. See
+ * 		the following snippet:
+ *
+ * 		::
+ *
+ * 			SEC("kprobe/sys_open")
+ * 			void bpf_sys_open(struct pt_regs *ctx)
+ * 			{
+ * 			        char buf[PATHLEN]; // PATHLEN is defined to 256
+ * 			        int res = bpf_probe_read_str(buf, sizeof(buf),
+ * 				                             ctx->di);
+ *
+ * 				// Consume buf, for example push it to
+ * 				// userspace via bpf_perf_event_output(); we
+ * 				// can use res (the string length) as event
+ * 				// size, after checking its boundaries.
+ * 			}
+ *
+ * 		In comparison, using **bpf_probe_read()** helper here instead
+ * 		to read the string would require to estimate the length at
+ * 		compile time, and would often result in copying more memory
+ * 		than necessary.
+ *
+ * 		Another useful use case is when parsing individual process
+ * 		arguments or individual environment variables navigating
+ * 		*current*\ **->mm->arg_start** and *current*\
+ * 		**->mm->env_start**: using this helper and the return value,
+ * 		one can quickly iterate at the right offset of the memory area.
+ * 	Return
+ * 		On success, the strictly positive length of the string,
+ * 		including the trailing NUL character. On error, a negative
+ * 		value.
+ *
+ * u64 bpf_get_socket_cookie(struct sk_buff *skb)
+ * 	Description
+ * 		If the **struct sk_buff** pointed by *skb* has a known socket,
+ * 		retrieve the cookie (generated by the kernel) of this socket.
+ * 		If no cookie has been set yet, generate a new cookie. Once
+ * 		generated, the socket cookie remains stable for the life of the
+ * 		socket. This helper can be useful for monitoring per socket
+ * 		networking traffic statistics as it provides a unique socket
+ * 		identifier per namespace.
+ * 	Return
+ * 		A 8-byte long non-decreasing number on success, or 0 if the
+ * 		socket field is missing inside *skb*.
+ *
+ * u32 bpf_get_socket_uid(struct sk_buff *skb)
+ * 	Return
+ * 		The owner UID of the socket associated to *skb*. If the socket
+ * 		is **NULL**, or if it is not a full socket (i.e. if it is a
+ * 		time-wait or a request socket instead), **overflowuid** value
+ * 		is returned (note that **overflowuid** might also be the actual
+ * 		UID value for the socket).
+ *
+ * u32 bpf_set_hash(struct sk_buff *skb, u32 hash)
+ * 	Description
+ * 		Set the full hash for *skb* (set the field *skb*\ **->hash**)
+ * 		to value *hash*.
+ * 	Return
+ * 		0
+ *
+ * int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
+ * 	Description
+ * 		Emulate a call to **setsockopt()** on the socket associated to
+ * 		*bpf_socket*, which must be a full socket. The *level* at
+ * 		which the option resides and the name *optname* of the option
+ * 		must be specified, see **setsockopt(2)** for more information.
+ * 		The option value of length *optlen* is pointed by *optval*.
+ *
+ * 		This helper actually implements a subset of **setsockopt()**.
+ * 		It supports the following *level*\ s:
+ *
+ * 		* **SOL_SOCKET**, which supports the following *optname*\ s:
+ * 		  **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
+ * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
+ * 		* **IPPROTO_TCP**, which supports the following *optname*\ s:
+ * 		  **TCP_CONGESTION**, **TCP_BPF_IW**,
+ * 		  **TCP_BPF_SNDCWND_CLAMP**.
+ * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
+ * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_adjust_room(struct sk_buff *skb, u32 len_diff, u32 mode, u64 flags)
+ * 	Description
+ * 		Grow or shrink the room for data in the packet associated to
+ * 		*skb* by *len_diff*, and according to the selected *mode*.
+ *
+ * 		There is a single supported mode at this time:
+ *
+ * 		* **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
+ * 		  (room space is added or removed below the layer 3 header).
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		Redirect the packet to the endpoint referenced by *map* at
+ * 		index *key*. Depending on its type, this *map* can contain
+ * 		references to net devices (for forwarding packets through other
+ * 		ports), or to CPUs (for redirecting XDP frames to another CPU;
+ * 		but this is only implemented for native XDP (with driver
+ * 		support) as of this writing).
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		When used to redirect packets to net devices, this helper
+ * 		provides a high performance increase over **bpf_redirect**\ ().
+ * 		This is due to various implementation details of the underlying
+ * 		mechanisms, one of which is the fact that **bpf_redirect_map**\
+ * 		() tries to send packet as a "bulk" to the device.
+ * 	Return
+ * 		**XDP_REDIRECT** on success, or **XDP_ABORTED** on error.
+ *
+ * int bpf_sk_redirect_map(struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		Redirect the packet to the socket referenced by *map* (of type
+ * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
+ * 		egress interfaces can be used for redirection. The
+ * 		**BPF_F_INGRESS** value in *flags* is used to make the
+ * 		distinction (ingress path is selected if the flag is present,
+ * 		egress path otherwise). This is the only flag supported for now.
+ * 	Return
+ * 		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
+ * 	Description
+ * 		Add an entry to, or update a *map* referencing sockets. The
+ * 		*skops* is used as a new value for the entry associated to
+ * 		*key*. *flags* is one of:
+ *
+ * 		**BPF_NOEXIST**
+ * 			The entry for *key* must not exist in the map.
+ * 		**BPF_EXIST**
+ * 			The entry for *key* must already exist in the map.
+ * 		**BPF_ANY**
+ * 			No condition on the existence of the entry for *key*.
+ *
+ * 		If the *map* has eBPF programs (parser and verdict), those will
+ * 		be inherited by the socket being added. If the socket is
+ * 		already attached to eBPF programs, this results in an error.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust the address pointed by *xdp_md*\ **->data_meta** by
+ * 		*delta* (which can be positive or negative). Note that this
+ * 		operation modifies the address stored in *xdp_md*\ **->data**,
+ * 		so the latter must be loaded only after the helper has been
+ * 		called.
+ *
+ * 		The use of *xdp_md*\ **->data_meta** is optional and programs
+ * 		are not required to use it. The rationale is that when the
+ * 		packet is processed with XDP (e.g. as DoS filter), it is
+ * 		possible to push further meta data along with it before passing
+ * 		to the stack, and to give the guarantee that an ingress eBPF
+ * 		program attached as a TC classifier on the same device can pick
+ * 		this up for further post-processing. Since TC works with socket
+ * 		buffers, it remains possible to set from XDP the **mark** or
+ * 		**priority** pointers, or other pointers for the socket buffer.
+ * 		Having this scratch space generic and programmable allows for
+ * 		more flexibility as the user is free to store whatever meta
+ * 		data they need.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
+ * 	Description
+ * 		Read the value of a perf event counter, and store it into *buf*
+ * 		of size *buf_size*. This helper relies on a *map* of type
+ * 		**BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
+ * 		counter is selected when *map* is updated with perf event file
+ * 		descriptors. The *map* is an array whose size is the number of
+ * 		available CPUs, and each cell contains a value relative to one
+ * 		CPU. The value to retrieve is indicated by *flags*, that
+ * 		contains the index of the CPU to look up, masked with
+ * 		**BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
+ * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
+ * 		current CPU should be retrieved.
+ *
+ * 		This helper behaves in a way close to
+ * 		**bpf_perf_event_read**\ () helper, save that instead of
+ * 		just returning the value observed, it fills the *buf*
+ * 		structure. This allows for additional data to be retrieved: in
+ * 		particular, the enabled and running times (in *buf*\
+ * 		**->enabled** and *buf*\ **->running**, respectively) are
+ * 		copied. In general, **bpf_perf_event_read_value**\ () is
+ * 		recommended over **bpf_perf_event_read**\ (), which has some
+ * 		ABI issues and provides fewer functionalities.
+ *
+ * 		These values are interesting, because hardware PMU (Performance
+ * 		Monitoring Unit) counters are limited resources. When there are
+ * 		more PMU based perf events opened than available counters,
+ * 		kernel will multiplex these events so each event gets certain
+ * 		percentage (but not all) of the PMU time. In case that
+ * 		multiplexing happens, the number of samples or counter value
+ * 		will not reflect the case compared to when no multiplexing
+ * 		occurs. This makes comparison between different runs difficult.
+ * 		Typically, the counter value should be normalized before
+ * 		comparing to other experiments. The usual normalization is done
+ * 		as follows.
+ *
+ * 		::
+ *
+ * 			normalized_counter = counter * t_enabled / t_running
+ *
+ * 		Where t_enabled is the time enabled for event and t_running is
+ * 		the time running for event since last normalization. The
+ * 		enabled and running times are accumulated since the perf event
+ * 		open. To achieve scaling factor between two invocations of an
+ * 		eBPF program, users can can use CPU id as the key (which is
+ * 		typical for perf array usage model) to remember the previous
+ * 		value and do the calculation inside the eBPF program.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
+ * 	Description
+ * 		For en eBPF program attached to a perf event, retrieve the
+ * 		value of the event counter associated to *ctx* and store it in
+ * 		the structure pointed by *buf* and of size *buf_size*. Enabled
+ * 		and running times are also stored in the structure (see
+ * 		description of helper **bpf_perf_event_read_value**\ () for
+ * 		more details).
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
+ * 	Description
+ * 		Emulate a call to **getsockopt()** on the socket associated to
+ * 		*bpf_socket*, which must be a full socket. The *level* at
+ * 		which the option resides and the name *optname* of the option
+ * 		must be specified, see **getsockopt(2)** for more information.
+ * 		The retrieved value is stored in the structure pointed by
+ * 		*opval* and of length *optlen*.
+ *
+ * 		This helper actually implements a subset of **getsockopt()**.
+ * 		It supports the following *level*\ s:
+ *
+ * 		* **IPPROTO_TCP**, which supports *optname*
+ * 		  **TCP_CONGESTION**.
+ * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
+ * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_override_return(struct pt_reg *regs, u64 rc)
+ * 	Description
+ * 		Used for error injection, this helper uses kprobes to override
+ * 		the return value of the probed function, and to set it to *rc*.
+ * 		The first argument is the context *regs* on which the kprobe
+ * 		works.
+ *
+ * 		This helper works by setting setting the PC (program counter)
+ * 		to an override function which is run in place of the original
+ * 		probed function. This means the probed function is not run at
+ * 		all. The replacement function just returns with the required
+ * 		value.
+ *
+ * 		This helper has security implications, and thus is subject to
+ * 		restrictions. It is only available if the kernel was compiled
+ * 		with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
+ * 		option, and in this case it only works on functions tagged with
+ * 		**ALLOW_ERROR_INJECTION** in the kernel code.
+ *
+ * 		Also, the helper is only available for the architectures having
+ * 		the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
+ * 		x86 architecture is the only one to support this feature.
+ * 	Return
+ * 		0
+ *
+ * int bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
+ * 	Description
+ * 		Attempt to set the value of the **bpf_sock_ops_cb_flags** field
+ * 		for the full TCP socket associated to *bpf_sock_ops* to
+ * 		*argval*.
+ *
+ * 		The primary use of this field is to determine if there should
+ * 		be calls to eBPF programs of type
+ * 		**BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
+ * 		code. A program of the same type can change its value, per
+ * 		connection and as necessary, when the connection is
+ * 		established. This field is directly accessible for reading, but
+ * 		this helper must be used for updates in order to return an
+ * 		error if an eBPF program tries to set a callback that is not
+ * 		supported in the current kernel.
+ *
+ * 		The supported callback values that *argval* can combine are:
+ *
+ * 		* **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
+ * 		* **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
+ * 		* **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
+ *
+ * 		Here are some examples of where one could call such eBPF
+ * 		program:
+ *
+ * 		* When RTO fires.
+ * 		* When a packet is retransmitted.
+ * 		* When the connection terminates.
+ * 		* When a packet is sent.
+ * 		* When a packet is received.
+ * 	Return
+ * 		Code **-EINVAL** if the socket is not a full TCP socket;
+ * 		otherwise, a positive number containing the bits that could not
+ * 		be set is returned (which comes down to 0 if all bits were set
+ * 		as required).
+ *
+ * int bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
+ * 	Description
+ * 		This helper is used in programs implementing policies at the
+ * 		socket level. If the message *msg* is allowed to pass (i.e. if
+ * 		the verdict eBPF program returns **SK_PASS**), redirect it to
+ * 		the socket referenced by *map* (of type
+ * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
+ * 		egress interfaces can be used for redirection. The
+ * 		**BPF_F_INGRESS** value in *flags* is used to make the
+ * 		distinction (ingress path is selected if the flag is present,
+ * 		egress path otherwise). This is the only flag supported for now.
+ * 	Return
+ * 		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
+ * 	Description
+ * 		For socket policies, apply the verdict of the eBPF program to
+ * 		the next *bytes* (number of bytes) of message *msg*.
+ *
+ * 		For example, this helper can be used in the following cases:
+ *
+ * 		* A single **sendmsg**\ () or **sendfile**\ () system call
+ * 		  contains multiple logical messages that the eBPF program is
+ * 		  supposed to read and for which it should apply a verdict.
+ * 		* An eBPF program only cares to read the first *bytes* of a
+ * 		  *msg*. If the message has a large payload, then setting up
+ * 		  and calling the eBPF program repeatedly for all bytes, even
+ * 		  though the verdict is already known, would create unnecessary
+ * 		  overhead.
+ *
+ * 		When called from within an eBPF program, the helper sets a
+ * 		counter internal to the BPF infrastructure, that is used to
+ * 		apply the last verdict to the next *bytes*. If *bytes* is
+ * 		smaller than the current data being processed from a
+ * 		**sendmsg**\ () or **sendfile**\ () system call, the first
+ * 		*bytes* will be sent and the eBPF program will be re-run with
+ * 		the pointer for start of data pointing to byte number *bytes*
+ * 		**+ 1**. If *bytes* is larger than the current data being
+ * 		processed, then the eBPF verdict will be applied to multiple
+ * 		**sendmsg**\ () or **sendfile**\ () calls until *bytes* are
+ * 		consumed.
+ *
+ * 		Note that if a socket closes with the internal counter holding
+ * 		a non-zero value, this is not a problem because data is not
+ * 		being buffered for *bytes* and is sent as it is received.
+ * 	Return
+ * 		0
+ *
+ * int bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
+ * 	Description
+ * 		For socket policies, prevent the execution of the verdict eBPF
+ * 		program for message *msg* until *bytes* (byte number) have been
+ * 		accumulated.
+ *
+ * 		This can be used when one needs a specific number of bytes
+ * 		before a verdict can be assigned, even if the data spans
+ * 		multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
+ * 		case would be a user calling **sendmsg**\ () repeatedly with
+ * 		1-byte long message segments. Obviously, this is bad for
+ * 		performance, but it is still valid. If the eBPF program needs
+ * 		*bytes* bytes to validate a header, this helper can be used to
+ * 		prevent the eBPF program to be called again until *bytes* have
+ * 		been accumulated.
+ * 	Return
+ * 		0
+ *
+ * int bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
+ * 	Description
+ * 		For socket policies, pull in non-linear data from user space
+ * 		for *msg* and set pointers *msg*\ **->data** and *msg*\
+ * 		**->data_end** to *start* and *end* bytes offsets into *msg*,
+ * 		respectively.
+ *
+ * 		If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
+ * 		*msg* it can only parse data that the (**data**, **data_end**)
+ * 		pointers have already consumed. For **sendmsg**\ () hooks this
+ * 		is likely the first scatterlist element. But for calls relying
+ * 		on the **sendpage** handler (e.g. **sendfile**\ ()) this will
+ * 		be the range (**0**, **0**) because the data is shared with
+ * 		user space and by default the objective is to avoid allowing
+ * 		user space to modify data while (or after) eBPF verdict is
+ * 		being decided. This helper can be used to pull in data and to
+ * 		set the start and end pointer to given values. Data will be
+ * 		copied if necessary (i.e. if data was not linear and if start
+ * 		and end pointers do not point to the same chunk).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
+ * 	Description
+ * 		Bind the socket associated to *ctx* to the address pointed by
+ * 		*addr*, of length *addr_len*. This allows for making outgoing
+ * 		connection from the desired IP address, which can be useful for
+ * 		example when all processes inside a cgroup should use one
+ * 		single IP address on a host that has multiple IP configured.
+ *
+ * 		This helper works for IPv4 and IPv6, TCP and UDP sockets. The
+ * 		domain (*addr*\ **->sa_family**) must be **AF_INET** (or
+ * 		**AF_INET6**). Looking for a free port to bind to can be
+ * 		expensive, therefore binding to port is not permitted by the
+ * 		helper: *addr*\ **->sin_port** (or **sin6_port**, respectively)
+ * 		must be set to zero.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
+ * 	Description
+ * 		Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
+ * 		only possible to shrink the packet as of this writing,
+ * 		therefore *delta* must be a negative integer.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
+ * 	Description
+ * 		Retrieve the XFRM state (IP transform framework, see also
+ * 		**ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
+ *
+ * 		The retrieved value is stored in the **struct bpf_xfrm_state**
+ * 		pointed by *xfrm_state* and of length *size*.
+ *
+ * 		All values for *flags* are reserved for future usage, and must
+ * 		be left at zero.
+ *
+ * 		This helper is available only if the kernel was compiled with
+ * 		**CONFIG_XFRM** configuration option.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_stack(struct pt_regs *regs, void *buf, u32 size, u64 flags)
+ * 	Description
+ * 		Return a user or a kernel stack in bpf program provided buffer.
+ * 		To achieve this, the helper needs *ctx*, which is a pointer
+ * 		to the context on which the tracing program is executed.
+ * 		To store the stacktrace, the bpf program provides *buf* with
+ * 		a nonnegative *size*.
+ *
+ * 		The last argument, *flags*, holds the number of stack frames to
+ * 		skip (from 0 to 255), masked with
+ * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
+ * 		the following flags:
+ *
+ * 		**BPF_F_USER_STACK**
+ * 			Collect a user space stack instead of a kernel stack.
+ * 		**BPF_F_USER_BUILD_ID**
+ * 			Collect buildid+offset instead of ips for user stack,
+ * 			only valid if **BPF_F_USER_STACK** is also specified.
+ *
+ * 		**bpf_get_stack**\ () can collect up to
+ * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
+ * 		to sufficient large buffer size. Note that
+ * 		this limit can be controlled with the **sysctl** program, and
+ * 		that it should be manually increased in order to profile long
+ * 		user stacks (such as stacks for Java programs). To do so, use:
+ *
+ * 		::
+ *
+ * 			# sysctl kernel.perf_event_max_stack=<new value>
+ * 	Return
+ * 		A non-negative value equal to or less than *size* on success,
+ * 		or a negative error in case of failure.
+ *
+ * int skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header)
+ * 	Description
+ * 		This helper is similar to **bpf_skb_load_bytes**\ () in that
+ * 		it provides an easy way to load *len* bytes from *offset*
+ * 		from the packet associated to *skb*, into the buffer pointed
+ * 		by *to*. The difference to **bpf_skb_load_bytes**\ () is that
+ * 		a fifth argument *start_header* exists in order to select a
+ * 		base offset to start from. *start_header* can be one of:
+ *
+ * 		**BPF_HDR_START_MAC**
+ * 			Base offset to load data from is *skb*'s mac header.
+ * 		**BPF_HDR_START_NET**
+ * 			Base offset to load data from is *skb*'s network header.
+ *
+ * 		In general, "direct packet access" is the preferred method to
+ * 		access packet data, however, this helper is in particular useful
+ * 		in socket filters where *skb*\ **->data** does not always point
+ * 		to the start of the mac header and where "direct packet access"
+ * 		is not available.
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
+ *	Description
+ *		Do FIB lookup in kernel tables using parameters in *params*.
+ *		If lookup is successful and result shows packet is to be
+ *		forwarded, the neighbor tables are searched for the nexthop.
+ *		If successful (ie., FIB lookup shows forwarding and nexthop
+ *		is resolved), the nexthop address is returned in ipv4_dst
+ *		or ipv6_dst based on family, smac is set to mac address of
+ *		egress device, dmac is set to nexthop mac address, rt_metric
+ *		is set to metric from route (IPv4/IPv6 only).
+ *
+ *             *plen* argument is the size of the passed in struct.
+ *             *flags* argument can be a combination of one or more of the
+ *             following values:
+ *
+ *		**BPF_FIB_LOOKUP_DIRECT**
+ *			Do a direct table lookup vs full lookup using FIB
+ *			rules.
+ *		**BPF_FIB_LOOKUP_OUTPUT**
+ *			Perform lookup from an egress perspective (default is
+ *			ingress).
+ *
+ *             *ctx* is either **struct xdp_md** for XDP programs or
+ *             **struct sk_buff** tc cls_act programs.
+ *     Return
+ *             Egress device index on success, 0 if packet needs to continue
+ *             up the stack for further processing or a negative error in case
+ *             of failure.
+ *
+ * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		Add an entry to, or update a sockhash *map* referencing sockets.
+ *		The *skops* is used as a new value for the entry associated to
+ *		*key*. *flags* is one of:
+ *
+ *		**BPF_NOEXIST**
+ *			The entry for *key* must not exist in the map.
+ *		**BPF_EXIST**
+ *			The entry for *key* must already exist in the map.
+ *		**BPF_ANY**
+ *			No condition on the existence of the entry for *key*.
+ *
+ *		If the *map* has eBPF programs (parser and verdict), those will
+ *		be inherited by the socket being added. If the socket is
+ *		already attached to eBPF programs, this results in an error.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		This helper is used in programs implementing policies at the
+ *		socket level. If the message *msg* is allowed to pass (i.e. if
+ *		the verdict eBPF program returns **SK_PASS**), redirect it to
+ *		the socket referenced by *map* (of type
+ *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *		egress interfaces can be used for redirection. The
+ *		**BPF_F_INGRESS** value in *flags* is used to make the
+ *		distinction (ingress path is selected if the flag is present,
+ *		egress path otherwise). This is the only flag supported for now.
+ *	Return
+ *		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
+ *	Description
+ *		This helper is used in programs implementing policies at the
+ *		skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
+ *		if the verdeict eBPF program returns **SK_PASS**), redirect it
+ *		to the socket referenced by *map* (of type
+ *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
+ *		egress interfaces can be used for redirection. The
+ *		**BPF_F_INGRESS** value in *flags* is used to make the
+ *		distinction (ingress path is selected if the flag is present,
+ *		egress otherwise). This is the only flag supported for now.
+ *	Return
+ *		**SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
+ *	Description
+ *		Encapsulate the packet associated to *skb* within a Layer 3
+ *		protocol header. This header is provided in the buffer at
+ *		address *hdr*, with *len* its size in bytes. *type* indicates
+ *		the protocol of the header and can be one of:
+ *
+ *		**BPF_LWT_ENCAP_SEG6**
+ *			IPv6 encapsulation with Segment Routing Header
+ *			(**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
+ *			the IPv6 header is computed by the kernel.
+ *		**BPF_LWT_ENCAP_SEG6_INLINE**
+ *			Only works if *skb* contains an IPv6 packet. Insert a
+ *			Segment Routing Header (**struct ipv6_sr_hdr**) inside
+ *			the IPv6 header.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
+ *	Description
+ *		Store *len* bytes from address *from* into the packet
+ *		associated to *skb*, at *offset*. Only the flags, tag and TLVs
+ *		inside the outermost IPv6 Segment Routing Header can be
+ *		modified through this helper.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
+ *	Description
+ *		Adjust the size allocated to TLVs in the outermost IPv6
+ *		Segment Routing Header contained in the packet associated to
+ *		*skb*, at position *offset* by *delta* bytes. Only offsets
+ *		after the segments are accepted. *delta* can be as well
+ *		positive (growing) as negative (shrinking).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
+ *	Description
+ *		Apply an IPv6 Segment Routing action of type *action* to the
+ *		packet associated to *skb*. Each action takes a parameter
+ *		contained at address *param*, and of length *param_len* bytes.
+ *		*action* can be one of:
+ *
+ *		**SEG6_LOCAL_ACTION_END_X**
+ *			End.X action: Endpoint with Layer-3 cross-connect.
+ *			Type of *param*: **struct in6_addr**.
+ *		**SEG6_LOCAL_ACTION_END_T**
+ *			End.T action: Endpoint with specific IPv6 table lookup.
+ *			Type of *param*: **int**.
+ *		**SEG6_LOCAL_ACTION_END_B6**
+ *			End.B6 action: Endpoint bound to an SRv6 policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**
+ *			End.B6.Encap action: Endpoint bound to an SRv6
+ *			encapsulation policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
+ *	Description
+ *		This helper is used in programs implementing IR decoding, to
+ *		report a successfully decoded key press with *scancode*,
+ *		*toggle* value in the given *protocol*. The scancode will be
+ *		translated to a keycode using the rc keymap, and reported as
+ *		an input key down event. After a period a key up event is
+ *		generated. This period can be extended by calling either
+ *		**bpf_rc_keydown** () again with the same values, or calling
+ *		**bpf_rc_repeat** ().
+ *
+ *		Some protocols include a toggle bit, in case the button	was
+ *		released and pressed again between consecutive scancodes.
+ *
+ *		The *ctx* should point to the lirc sample as passed into
+ *		the program.
+ *
+ *		The *protocol* is the decoded protocol number (see
+ *		**enum rc_proto** for some predefined values).
+ *
+ *		This helper is only available is the kernel was compiled with
+ *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
+ *		"**y**".
+ *
+ *	Return
+ *		0
+ *
+ * int bpf_rc_repeat(void *ctx)
+ *	Description
+ *		This helper is used in programs implementing IR decoding, to
+ *		report a successfully decoded repeat key message. This delays
+ *		the generation of a key up event for previously generated
+ *		key down event.
+ *
+ *		Some IR protocols like NEC have a special IR message for
+ *		repeating last button, for when a button is held down.
+ *
+ *		The *ctx* should point to the lirc sample as passed into
+ *		the program.
+ *
+ *		This helper is only available is the kernel was compiled with
+ *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
+ *		"**y**".
+ *
+ *	Return
+ *		0
+ */
+#define __BPF_FUNC_MAPPER(FN)		\
+	FN(unspec),			\
+	FN(map_lookup_elem),		\
+	FN(map_update_elem),		\
+	FN(map_delete_elem),		\
+	FN(probe_read),			\
+	FN(ktime_get_ns),		\
+	FN(trace_printk),		\
+	FN(get_prandom_u32),		\
+	FN(get_smp_processor_id),	\
+	FN(skb_store_bytes),		\
+	FN(l3_csum_replace),		\
+	FN(l4_csum_replace),		\
+	FN(tail_call),			\
+	FN(clone_redirect),		\
+	FN(get_current_pid_tgid),	\
+	FN(get_current_uid_gid),	\
+	FN(get_current_comm),		\
+	FN(get_cgroup_classid),		\
+	FN(skb_vlan_push),		\
+	FN(skb_vlan_pop),		\
+	FN(skb_get_tunnel_key),		\
+	FN(skb_set_tunnel_key),		\
+	FN(perf_event_read),		\
+	FN(redirect),			\
+	FN(get_route_realm),		\
+	FN(perf_event_output),		\
+	FN(skb_load_bytes),		\
+	FN(get_stackid),		\
+	FN(csum_diff),			\
+	FN(skb_get_tunnel_opt),		\
+	FN(skb_set_tunnel_opt),		\
+	FN(skb_change_proto),		\
+	FN(skb_change_type),		\
+	FN(skb_under_cgroup),		\
+	FN(get_hash_recalc),		\
+	FN(get_current_task),		\
+	FN(probe_write_user),		\
+	FN(current_task_under_cgroup),	\
+	FN(skb_change_tail),		\
+	FN(skb_pull_data),		\
+	FN(csum_update),		\
+	FN(set_hash_invalid),		\
+	FN(get_numa_node_id),		\
+	FN(skb_change_head),		\
+	FN(xdp_adjust_head),		\
+	FN(probe_read_str),		\
+	FN(get_socket_cookie),		\
+	FN(get_socket_uid),		\
+	FN(set_hash),			\
+	FN(setsockopt),			\
+	FN(skb_adjust_room),		\
+	FN(redirect_map),		\
+	FN(sk_redirect_map),		\
+	FN(sock_map_update),		\
+	FN(xdp_adjust_meta),		\
+	FN(perf_event_read_value),	\
+	FN(perf_prog_read_value),	\
+	FN(getsockopt),			\
+	FN(override_return),		\
+	FN(sock_ops_cb_flags_set),	\
+	FN(msg_redirect_map),		\
+	FN(msg_apply_bytes),		\
+	FN(msg_cork_bytes),		\
+	FN(msg_pull_data),		\
+	FN(bind),			\
+	FN(xdp_adjust_tail),		\
+	FN(skb_get_xfrm_state),		\
+	FN(get_stack),			\
+	FN(skb_load_bytes_relative),	\
+	FN(fib_lookup),			\
+	FN(sock_hash_update),		\
+	FN(msg_redirect_hash),		\
+	FN(sk_redirect_hash),		\
+	FN(lwt_push_encap),		\
+	FN(lwt_seg6_store_bytes),	\
+	FN(lwt_seg6_adjust_srh),	\
+	FN(lwt_seg6_action),		\
+	FN(rc_repeat),			\
+	FN(rc_keydown),
+
+/* integer value in 'imm' field of BPF_CALL instruction selects which helper
+ * function eBPF program intends to call
+ */
+#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
+enum bpf_func_id {
+	__BPF_FUNC_MAPPER(__BPF_ENUM_FN)
+	__BPF_FUNC_MAX_ID,
+};
+#undef __BPF_ENUM_FN
+
+/* All flags used by eBPF helper functions, placed here. */
+
+/* BPF_FUNC_skb_store_bytes flags. */
+#define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
+#define BPF_F_INVALIDATE_HASH		(1ULL << 1)
+
+/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
+ * First 4 bits are for passing the header field size.
+ */
+#define BPF_F_HDR_FIELD_MASK		0xfULL
+
+/* BPF_FUNC_l4_csum_replace flags. */
+#define BPF_F_PSEUDO_HDR		(1ULL << 4)
+#define BPF_F_MARK_MANGLED_0		(1ULL << 5)
+#define BPF_F_MARK_ENFORCE		(1ULL << 6)
+
+/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
+#define BPF_F_INGRESS			(1ULL << 0)
+
+/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
+#define BPF_F_TUNINFO_IPV6		(1ULL << 0)
+
+/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
+#define BPF_F_SKIP_FIELD_MASK		0xffULL
+#define BPF_F_USER_STACK		(1ULL << 8)
+/* flags used by BPF_FUNC_get_stackid only. */
+#define BPF_F_FAST_STACK_CMP		(1ULL << 9)
+#define BPF_F_REUSE_STACKID		(1ULL << 10)
+/* flags used by BPF_FUNC_get_stack only. */
+#define BPF_F_USER_BUILD_ID		(1ULL << 11)
+
+/* BPF_FUNC_skb_set_tunnel_key flags. */
+#define BPF_F_ZERO_CSUM_TX		(1ULL << 1)
+#define BPF_F_DONT_FRAGMENT		(1ULL << 2)
+#define BPF_F_SEQ_NUMBER		(1ULL << 3)
+
+/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
+ * BPF_FUNC_perf_event_read_value flags.
+ */
+#define BPF_F_INDEX_MASK		0xffffffffULL
+#define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
+/* BPF_FUNC_perf_event_output for sk_buff input context. */
+#define BPF_F_CTXLEN_MASK		(0xfffffULL << 32)
+
+/* Mode for BPF_FUNC_skb_adjust_room helper. */
+enum bpf_adj_room_mode {
+	BPF_ADJ_ROOM_NET,
+};
+
+/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
+enum bpf_hdr_start_off {
+	BPF_HDR_START_MAC,
+	BPF_HDR_START_NET,
+};
+
+/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
+enum bpf_lwt_encap_mode {
+	BPF_LWT_ENCAP_SEG6,
+	BPF_LWT_ENCAP_SEG6_INLINE
+};
+
+/* user accessible mirror of in-kernel sk_buff.
+ * new fields can only be added to the end of this structure
+ */
+struct __sk_buff {
+	__u32 len;
+	__u32 pkt_type;
+	__u32 mark;
+	__u32 queue_mapping;
+	__u32 protocol;
+	__u32 vlan_present;
+	__u32 vlan_tci;
+	__u32 vlan_proto;
+	__u32 priority;
+	__u32 ingress_ifindex;
+	__u32 ifindex;
+	__u32 tc_index;
+	__u32 cb[5];
+	__u32 hash;
+	__u32 tc_classid;
+	__u32 data;
+	__u32 data_end;
+	__u32 napi_id;
+
+	/* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+	/* ... here. */
+
+	__u32 data_meta;
+};
+
+struct bpf_tunnel_key {
+	__u32 tunnel_id;
+	union {
+		__u32 remote_ipv4;
+		__u32 remote_ipv6[4];
+	};
+	__u8 tunnel_tos;
+	__u8 tunnel_ttl;
+	__u16 tunnel_ext;
+	__u32 tunnel_label;
+};
+
+/* user accessible mirror of in-kernel xfrm_state.
+ * new fields can only be added to the end of this structure
+ */
+struct bpf_xfrm_state {
+	__u32 reqid;
+	__u32 spi;	/* Stored in network byte order */
+	__u16 family;
+	union {
+		__u32 remote_ipv4;	/* Stored in network byte order */
+		__u32 remote_ipv6[4];	/* Stored in network byte order */
+	};
+};
+
+/* Generic BPF return codes which all BPF program types may support.
+ * The values are binary compatible with their TC_ACT_* counter-part to
+ * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
+ * programs.
+ *
+ * XDP is handled seprately, see XDP_*.
+ */
+enum bpf_ret_code {
+	BPF_OK = 0,
+	/* 1 reserved */
+	BPF_DROP = 2,
+	/* 3-6 reserved */
+	BPF_REDIRECT = 7,
+	/* >127 are reserved for prog type specific return codes */
+};
+
+struct bpf_sock {
+	__u32 bound_dev_if;
+	__u32 family;
+	__u32 type;
+	__u32 protocol;
+	__u32 mark;
+	__u32 priority;
+	__u32 src_ip4;		/* Allows 1,2,4-byte read.
+				 * Stored in network byte order.
+				 */
+	__u32 src_ip6[4];	/* Allows 1,2,4-byte read.
+				 * Stored in network byte order.
+				 */
+	__u32 src_port;		/* Allows 4-byte read.
+				 * Stored in host byte order
+				 */
+};
+
+#define XDP_PACKET_HEADROOM 256
+
+/* User return codes for XDP prog type.
+ * A valid XDP program must return one of these defined values. All other
+ * return codes are reserved for future use. Unknown return codes will
+ * result in packet drops and a warning via bpf_warn_invalid_xdp_action().
+ */
+enum xdp_action {
+	XDP_ABORTED = 0,
+	XDP_DROP,
+	XDP_PASS,
+	XDP_TX,
+	XDP_REDIRECT,
+};
+
+/* user accessible metadata for XDP packet hook
+ * new fields must be added to the end of this structure
+ */
+struct xdp_md {
+	__u32 data;
+	__u32 data_end;
+	__u32 data_meta;
+	/* Below access go through struct xdp_rxq_info */
+	__u32 ingress_ifindex; /* rxq->dev->ifindex */
+	__u32 rx_queue_index;  /* rxq->queue_index  */
+};
+
+enum sk_action {
+	SK_DROP = 0,
+	SK_PASS,
+};
+
+/* user accessible metadata for SK_MSG packet hook, new fields must
+ * be added to the end of this structure
+ */
+struct sk_msg_md {
+	void *data;
+	void *data_end;
+
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+};
+
+#define BPF_TAG_SIZE	8
+
+struct bpf_prog_info {
+	__u32 type;
+	__u32 id;
+	__u8  tag[BPF_TAG_SIZE];
+	__u32 jited_prog_len;
+	__u32 xlated_prog_len;
+	__aligned_u64 jited_prog_insns;
+	__aligned_u64 xlated_prog_insns;
+	__u64 load_time;	/* ns since boottime */
+	__u32 created_by_uid;
+	__u32 nr_map_ids;
+	__aligned_u64 map_ids;
+	char name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u32 gpl_compatible:1;
+	__u64 netns_dev;
+	__u64 netns_ino;
+	__u32 nr_jited_ksyms;
+	__u32 nr_jited_func_lens;
+	__aligned_u64 jited_ksyms;
+	__aligned_u64 jited_func_lens;
+} __attribute__((aligned(8)));
+
+struct bpf_map_info {
+	__u32 type;
+	__u32 id;
+	__u32 key_size;
+	__u32 value_size;
+	__u32 max_entries;
+	__u32 map_flags;
+	char  name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u64 netns_dev;
+	__u64 netns_ino;
+	__u32 btf_id;
+	__u32 btf_key_type_id;
+	__u32 btf_value_type_id;
+} __attribute__((aligned(8)));
+
+struct bpf_btf_info {
+	__aligned_u64 btf;
+	__u32 btf_size;
+	__u32 id;
+} __attribute__((aligned(8)));
+
+/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
+ * by user and intended to be used by socket (e.g. to bind to, depends on
+ * attach attach type).
+ */
+struct bpf_sock_addr {
+	__u32 user_family;	/* Allows 4-byte read, but no write. */
+	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 user_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 user_port;	/* Allows 4-byte read and write.
+				 * Stored in network byte order
+				 */
+	__u32 family;		/* Allows 4-byte read, but no write */
+	__u32 type;		/* Allows 4-byte read, but no write */
+	__u32 protocol;		/* Allows 4-byte read, but no write */
+	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
+				 * Stored in network byte order.
+				 */
+};
+
+/* User bpf_sock_ops struct to access socket values and specify request ops
+ * and their replies.
+ * Some of this fields are in network (bigendian) byte order and may need
+ * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
+ * New fields can only be added at the end of this structure
+ */
+struct bpf_sock_ops {
+	__u32 op;
+	union {
+		__u32 args[4];		/* Optionally passed to bpf program */
+		__u32 reply;		/* Returned by bpf program	    */
+		__u32 replylong[4];	/* Optionally returned by bpf prog  */
+	};
+	__u32 family;
+	__u32 remote_ip4;	/* Stored in network byte order */
+	__u32 local_ip4;	/* Stored in network byte order */
+	__u32 remote_ip6[4];	/* Stored in network byte order */
+	__u32 local_ip6[4];	/* Stored in network byte order */
+	__u32 remote_port;	/* Stored in network byte order */
+	__u32 local_port;	/* stored in host byte order */
+	__u32 is_fullsock;	/* Some TCP fields are only valid if
+				 * there is a full socket. If not, the
+				 * fields read as zero.
+				 */
+	__u32 snd_cwnd;
+	__u32 srtt_us;		/* Averaged RTT << 3 in usecs */
+	__u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
+	__u32 state;
+	__u32 rtt_min;
+	__u32 snd_ssthresh;
+	__u32 rcv_nxt;
+	__u32 snd_nxt;
+	__u32 snd_una;
+	__u32 mss_cache;
+	__u32 ecn_flags;
+	__u32 rate_delivered;
+	__u32 rate_interval_us;
+	__u32 packets_out;
+	__u32 retrans_out;
+	__u32 total_retrans;
+	__u32 segs_in;
+	__u32 data_segs_in;
+	__u32 segs_out;
+	__u32 data_segs_out;
+	__u32 lost_out;
+	__u32 sacked_out;
+	__u32 sk_txhash;
+	__u64 bytes_received;
+	__u64 bytes_acked;
+};
+
+/* Definitions for bpf_sock_ops_cb_flags */
+#define BPF_SOCK_OPS_RTO_CB_FLAG	(1<<0)
+#define BPF_SOCK_OPS_RETRANS_CB_FLAG	(1<<1)
+#define BPF_SOCK_OPS_STATE_CB_FLAG	(1<<2)
+#define BPF_SOCK_OPS_ALL_CB_FLAGS       0x7		/* Mask of all currently
+							 * supported cb flags
+							 */
+
+/* List of known BPF sock_ops operators.
+ * New entries can only be added at the end
+ */
+enum {
+	BPF_SOCK_OPS_VOID,
+	BPF_SOCK_OPS_TIMEOUT_INIT,	/* Should return SYN-RTO value to use or
+					 * -1 if default value should be used
+					 */
+	BPF_SOCK_OPS_RWND_INIT,		/* Should return initial advertized
+					 * window (in packets) or -1 if default
+					 * value should be used
+					 */
+	BPF_SOCK_OPS_TCP_CONNECT_CB,	/* Calls BPF program right before an
+					 * active connection is initialized
+					 */
+	BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB,	/* Calls BPF program when an
+						 * active connection is
+						 * established
+						 */
+	BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB,	/* Calls BPF program when a
+						 * passive connection is
+						 * established
+						 */
+	BPF_SOCK_OPS_NEEDS_ECN,		/* If connection's congestion control
+					 * needs ECN
+					 */
+	BPF_SOCK_OPS_BASE_RTT,		/* Get base RTT. The correct value is
+					 * based on the path and may be
+					 * dependent on the congestion control
+					 * algorithm. In general it indicates
+					 * a congestion threshold. RTTs above
+					 * this indicate congestion
+					 */
+	BPF_SOCK_OPS_RTO_CB,		/* Called when an RTO has triggered.
+					 * Arg1: value of icsk_retransmits
+					 * Arg2: value of icsk_rto
+					 * Arg3: whether RTO has expired
+					 */
+	BPF_SOCK_OPS_RETRANS_CB,	/* Called when skb is retransmitted.
+					 * Arg1: sequence number of 1st byte
+					 * Arg2: # segments
+					 * Arg3: return value of
+					 *       tcp_transmit_skb (0 => success)
+					 */
+	BPF_SOCK_OPS_STATE_CB,		/* Called when TCP changes state.
+					 * Arg1: old_state
+					 * Arg2: new_state
+					 */
+};
+
+/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
+ * changes between the TCP and BPF versions. Ideally this should never happen.
+ * If it does, we need to add code to convert them before calling
+ * the BPF sock_ops function.
+ */
+enum {
+	BPF_TCP_ESTABLISHED = 1,
+	BPF_TCP_SYN_SENT,
+	BPF_TCP_SYN_RECV,
+	BPF_TCP_FIN_WAIT1,
+	BPF_TCP_FIN_WAIT2,
+	BPF_TCP_TIME_WAIT,
+	BPF_TCP_CLOSE,
+	BPF_TCP_CLOSE_WAIT,
+	BPF_TCP_LAST_ACK,
+	BPF_TCP_LISTEN,
+	BPF_TCP_CLOSING,	/* Now a valid state */
+	BPF_TCP_NEW_SYN_RECV,
+
+	BPF_TCP_MAX_STATES	/* Leave at the end! */
+};
+
+#define TCP_BPF_IW		1001	/* Set TCP initial congestion window */
+#define TCP_BPF_SNDCWND_CLAMP	1002	/* Set sndcwnd_clamp */
+
+struct bpf_perf_event_value {
+	__u64 counter;
+	__u64 enabled;
+	__u64 running;
+};
+
+#define BPF_DEVCG_ACC_MKNOD	(1ULL << 0)
+#define BPF_DEVCG_ACC_READ	(1ULL << 1)
+#define BPF_DEVCG_ACC_WRITE	(1ULL << 2)
+
+#define BPF_DEVCG_DEV_BLOCK	(1ULL << 0)
+#define BPF_DEVCG_DEV_CHAR	(1ULL << 1)
+
+struct bpf_cgroup_dev_ctx {
+	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
+	__u32 access_type;
+	__u32 major;
+	__u32 minor;
+};
+
+struct bpf_raw_tracepoint_args {
+	__u64 args[0];
+};
+
+/* DIRECT:  Skip the FIB rules and go to FIB table associated with device
+ * OUTPUT:  Do lookup from egress perspective; default is ingress
+ */
+#define BPF_FIB_LOOKUP_DIRECT  BIT(0)
+#define BPF_FIB_LOOKUP_OUTPUT  BIT(1)
+
+struct bpf_fib_lookup {
+	/* input:  network family for lookup (AF_INET, AF_INET6)
+	 * output: network family of egress nexthop
+	 */
+	__u8	family;
+
+	/* set if lookup is to consider L4 data - e.g., FIB rules */
+	__u8	l4_protocol;
+	__be16	sport;
+	__be16	dport;
+
+	/* total length of packet from network header - used for MTU check */
+	__u16	tot_len;
+	__u32	ifindex;  /* L3 device index for lookup */
+
+	union {
+		/* inputs to lookup */
+		__u8	tos;		/* AF_INET  */
+		__be32	flowlabel;	/* AF_INET6 */
+
+		/* output: metric of fib result (IPv4/IPv6 only) */
+		__u32	rt_metric;
+	};
+
+	union {
+		__be32		ipv4_src;
+		__u32		ipv6_src[4];  /* in6_addr; network order */
+	};
+
+	/* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
+	 * network header. output: bpf_fib_lookup sets to gateway address
+	 * if FIB lookup returns gateway route
+	 */
+	union {
+		__be32		ipv4_dst;
+		__u32		ipv6_dst[4];  /* in6_addr; network order */
+	};
+
+	/* output */
+	__be16	h_vlan_proto;
+	__be16	h_vlan_TCI;
+	__u8	smac[6];     /* ETH_ALEN */
+	__u8	dmac[6];     /* ETH_ALEN */
+};
+
+enum bpf_task_fd_type {
+	BPF_FD_TYPE_RAW_TRACEPOINT,	/* tp name */
+	BPF_FD_TYPE_TRACEPOINT,		/* tp name */
+	BPF_FD_TYPE_KPROBE,		/* (symbol + offset) or addr */
+	BPF_FD_TYPE_KRETPROBE,		/* (symbol + offset) or addr */
+	BPF_FD_TYPE_UPROBE,		/* filename + offset */
+	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
+};
+
+#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/utils/keytable/Makefile.am b/utils/keytable/Makefile.am
index 0bd7045f..df2b2231 100644
--- a/utils/keytable/Makefile.am
+++ b/utils/keytable/Makefile.am
@@ -5,8 +5,13 @@ keytablesystem_DATA = $(srcdir)/rc_keymaps/*
 udevrules_DATA = 70-infrared.rules
 
 ir_keytable_SOURCES = keytable.c parse.h ir-encode.c ir-encode.h toml.c toml.h
+
+if HAVE_LIBELF
+ir_keytable_SOURCES += bpf.c bpf_load.c bpf.h bpf_load.h
+endif
+
 ir_keytable_LDADD = @LIBINTL@
-ir_keytable_LDFLAGS = $(ARGP_LIBS)
+ir_keytable_LDFLAGS = $(ARGP_LIBS) $(LIBELF_LIBS)
 
 EXTRA_DIST = 70-infrared.rules rc_keymaps rc_keymaps_userspace gen_keytables.pl ir-keytable.1 rc_maps.cfg
 
diff --git a/utils/keytable/bpf.c b/utils/keytable/bpf.c
new file mode 100644
index 00000000..b1cd2507
--- /dev/null
+++ b/utils/keytable/bpf.c
@@ -0,0 +1,515 @@
+// SPDX-License-Identifier: LGPL-2.1
+
+/*
+ * common eBPF ELF operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not,  see <http://www.gnu.org/licenses>
+ */
+
+#include <stdlib.h>
+#include <memory.h>
+#include <unistd.h>
+#include <asm/unistd.h>
+#include <linux/bpf.h>
+#include "bpf.h"
+#include <errno.h>
+
+/*
+ * When building perf, unistd.h is overridden. __NR_bpf is
+ * required to be defined explicitly.
+ */
+#ifndef __NR_bpf
+# if defined(__i386__)
+#  define __NR_bpf 357
+# elif defined(__x86_64__)
+#  define __NR_bpf 321
+# elif defined(__aarch64__)
+#  define __NR_bpf 280
+# elif defined(__sparc__)
+#  define __NR_bpf 349
+# elif defined(__s390__)
+#  define __NR_bpf 351
+# else
+#  error __NR_bpf not defined. libbpf does not support your arch.
+# endif
+#endif
+
+#ifndef min
+#define min(x, y) ((x) < (y) ? (x) : (y))
+#endif
+
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
+static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
+			  unsigned int size)
+{
+	return syscall(__NR_bpf, cmd, attr, size);
+}
+
+int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
+{
+	__u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
+	union bpf_attr attr;
+
+	memset(&attr, '\0', sizeof(attr));
+
+	attr.map_type = create_attr->map_type;
+	attr.key_size = create_attr->key_size;
+	attr.value_size = create_attr->value_size;
+	attr.max_entries = create_attr->max_entries;
+	attr.map_flags = create_attr->map_flags;
+	memcpy(attr.map_name, create_attr->name,
+	       min(name_len, BPF_OBJ_NAME_LEN - 1));
+	attr.numa_node = create_attr->numa_node;
+	attr.btf_fd = create_attr->btf_fd;
+	attr.btf_key_type_id = create_attr->btf_key_type_id;
+	attr.btf_value_type_id = create_attr->btf_value_type_id;
+	attr.map_ifindex = create_attr->map_ifindex;
+
+	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
+			int key_size, int value_size, int max_entries,
+			__u32 map_flags, int node)
+{
+	struct bpf_create_map_attr map_attr = {};
+
+	map_attr.name = name;
+	map_attr.map_type = map_type;
+	map_attr.map_flags = map_flags;
+	map_attr.key_size = key_size;
+	map_attr.value_size = value_size;
+	map_attr.max_entries = max_entries;
+	if (node >= 0) {
+		map_attr.numa_node = node;
+		map_attr.map_flags |= BPF_F_NUMA_NODE;
+	}
+
+	return bpf_create_map_xattr(&map_attr);
+}
+
+int bpf_create_map(enum bpf_map_type map_type, int key_size,
+		   int value_size, int max_entries, __u32 map_flags)
+{
+	struct bpf_create_map_attr map_attr = {};
+
+	map_attr.map_type = map_type;
+	map_attr.map_flags = map_flags;
+	map_attr.key_size = key_size;
+	map_attr.value_size = value_size;
+	map_attr.max_entries = max_entries;
+
+	return bpf_create_map_xattr(&map_attr);
+}
+
+int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
+			int key_size, int value_size, int max_entries,
+			__u32 map_flags)
+{
+	struct bpf_create_map_attr map_attr = {};
+
+	map_attr.name = name;
+	map_attr.map_type = map_type;
+	map_attr.map_flags = map_flags;
+	map_attr.key_size = key_size;
+	map_attr.value_size = value_size;
+	map_attr.max_entries = max_entries;
+
+	return bpf_create_map_xattr(&map_attr);
+}
+
+int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
+			       int key_size, int inner_map_fd, int max_entries,
+			       __u32 map_flags, int node)
+{
+	__u32 name_len = name ? strlen(name) : 0;
+	union bpf_attr attr;
+
+	memset(&attr, '\0', sizeof(attr));
+
+	attr.map_type = map_type;
+	attr.key_size = key_size;
+	attr.value_size = 4;
+	attr.inner_map_fd = inner_map_fd;
+	attr.max_entries = max_entries;
+	attr.map_flags = map_flags;
+	memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
+
+	if (node >= 0) {
+		attr.map_flags |= BPF_F_NUMA_NODE;
+		attr.numa_node = node;
+	}
+
+	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
+			  int key_size, int inner_map_fd, int max_entries,
+			  __u32 map_flags)
+{
+	return bpf_create_map_in_map_node(map_type, name, key_size,
+					  inner_map_fd, max_entries, map_flags,
+					  -1);
+}
+
+int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
+			   char *log_buf, size_t log_buf_sz)
+{
+	union bpf_attr attr;
+	__u32 name_len;
+	int fd;
+
+	if (!load_attr)
+		return -EINVAL;
+
+	name_len = load_attr->name ? strlen(load_attr->name) : 0;
+
+	bzero(&attr, sizeof(attr));
+	attr.prog_type = load_attr->prog_type;
+	attr.expected_attach_type = load_attr->expected_attach_type;
+	attr.insn_cnt = (__u32)load_attr->insns_cnt;
+	attr.insns = ptr_to_u64(load_attr->insns);
+	attr.license = ptr_to_u64(load_attr->license);
+	attr.log_buf = ptr_to_u64(NULL);
+	attr.log_size = 0;
+	attr.log_level = 0;
+	attr.kern_version = load_attr->kern_version;
+	attr.prog_ifindex = load_attr->prog_ifindex;
+	memcpy(attr.prog_name, load_attr->name,
+	       min(name_len, BPF_OBJ_NAME_LEN - 1));
+
+	fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+	if (fd >= 0 || !log_buf || !log_buf_sz)
+		return fd;
+
+	/* Try again with log */
+	attr.log_buf = ptr_to_u64(log_buf);
+	attr.log_size = log_buf_sz;
+	attr.log_level = 1;
+	log_buf[0] = 0;
+	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
+int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		     size_t insns_cnt, const char *name, const char *license,
+		     __u32 kern_version, char *log_buf,
+		     size_t log_buf_sz)
+{
+	struct bpf_load_program_attr load_attr;
+
+	memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
+	load_attr.prog_type = type;
+	load_attr.expected_attach_type = 0;
+	load_attr.name = name;
+	load_attr.insns = insns;
+	load_attr.insns_cnt = insns_cnt;
+	load_attr.license = license;
+	load_attr.kern_version = kern_version;
+
+	return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
+}
+
+int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		       size_t insns_cnt, int strict_alignment,
+		       const char *license, __u32 kern_version,
+		       char *log_buf, size_t log_buf_sz, int log_level)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.prog_type = type;
+	attr.insn_cnt = (__u32)insns_cnt;
+	attr.insns = ptr_to_u64(insns);
+	attr.license = ptr_to_u64(license);
+	attr.log_buf = ptr_to_u64(log_buf);
+	attr.log_size = log_buf_sz;
+	attr.log_level = log_level;
+	log_buf[0] = 0;
+	attr.kern_version = kern_version;
+	attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
+
+	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
+
+int bpf_map_update_elem(int fd, const void *key, const void *value,
+			__u64 flags)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+	attr.flags = flags;
+
+	return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_map_lookup_elem(int fd, const void *key, void *value)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+
+	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_map_delete_elem(int fd, const void *key)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+
+	return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
+}
+
+int bpf_map_get_next_key(int fd, const void *key, void *next_key)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.next_key = ptr_to_u64(next_key);
+
+	return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
+}
+
+int bpf_obj_pin(int fd, const char *pathname)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.pathname = ptr_to_u64((void *)pathname);
+	attr.bpf_fd = fd;
+
+	return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
+}
+
+int bpf_obj_get(const char *pathname)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.pathname = ptr_to_u64((void *)pathname);
+
+	return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
+}
+
+int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
+		    unsigned int flags)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.target_fd	   = target_fd;
+	attr.attach_bpf_fd = prog_fd;
+	attr.attach_type   = type;
+	attr.attach_flags  = flags;
+
+	return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
+}
+
+int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.target_fd	 = target_fd;
+	attr.attach_type = type;
+
+	return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
+}
+
+int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.target_fd	 = target_fd;
+	attr.attach_bpf_fd = prog_fd;
+	attr.attach_type = type;
+
+	return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
+}
+
+int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
+		   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
+{
+	union bpf_attr attr;
+	int ret;
+
+	bzero(&attr, sizeof(attr));
+	attr.query.target_fd	= target_fd;
+	attr.query.attach_type	= type;
+	attr.query.query_flags	= query_flags;
+	attr.query.prog_cnt	= *prog_cnt;
+	attr.query.prog_ids	= ptr_to_u64(prog_ids);
+
+	ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
+	if (attach_flags)
+		*attach_flags = attr.query.attach_flags;
+	*prog_cnt = attr.query.prog_cnt;
+	return ret;
+}
+
+int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
+		      void *data_out, __u32 *size_out, __u32 *retval,
+		      __u32 *duration)
+{
+	union bpf_attr attr;
+	int ret;
+
+	bzero(&attr, sizeof(attr));
+	attr.test.prog_fd = prog_fd;
+	attr.test.data_in = ptr_to_u64(data);
+	attr.test.data_out = ptr_to_u64(data_out);
+	attr.test.data_size_in = size;
+	attr.test.repeat = repeat;
+
+	ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
+	if (size_out)
+		*size_out = attr.test.data_size_out;
+	if (retval)
+		*retval = attr.test.retval;
+	if (duration)
+		*duration = attr.test.duration;
+	return ret;
+}
+
+int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
+{
+	union bpf_attr attr;
+	int err;
+
+	bzero(&attr, sizeof(attr));
+	attr.start_id = start_id;
+
+	err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
+	if (!err)
+		*next_id = attr.next_id;
+
+	return err;
+}
+
+int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
+{
+	union bpf_attr attr;
+	int err;
+
+	bzero(&attr, sizeof(attr));
+	attr.start_id = start_id;
+
+	err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
+	if (!err)
+		*next_id = attr.next_id;
+
+	return err;
+}
+
+int bpf_prog_get_fd_by_id(__u32 id)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.prog_id = id;
+
+	return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
+}
+
+int bpf_map_get_fd_by_id(__u32 id)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_id = id;
+
+	return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
+}
+
+int bpf_btf_get_fd_by_id(__u32 id)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.btf_id = id;
+
+	return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
+}
+
+int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
+{
+	union bpf_attr attr;
+	int err;
+
+	bzero(&attr, sizeof(attr));
+	attr.info.bpf_fd = prog_fd;
+	attr.info.info_len = *info_len;
+	attr.info.info = ptr_to_u64(info);
+
+	err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
+	if (!err)
+		*info_len = attr.info.info_len;
+
+	return err;
+}
+
+int bpf_raw_tracepoint_open(const char *name, int prog_fd)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.raw_tracepoint.name = ptr_to_u64(name);
+	attr.raw_tracepoint.prog_fd = prog_fd;
+
+	return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
+}
+
+int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
+		 bool do_log)
+{
+	union bpf_attr attr = {};
+	int fd;
+
+	attr.btf = ptr_to_u64(btf);
+	attr.btf_size = btf_size;
+
+retry:
+	if (do_log && log_buf && log_buf_size) {
+		attr.btf_log_level = 1;
+		attr.btf_log_size = log_buf_size;
+		attr.btf_log_buf = ptr_to_u64(log_buf);
+	}
+
+	fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr));
+	if (fd == -1 && !do_log && log_buf && log_buf_size) {
+		do_log = true;
+		goto retry;
+	}
+
+	return fd;
+}
diff --git a/utils/keytable/bpf.h b/utils/keytable/bpf.h
new file mode 100644
index 00000000..fb3896c9
--- /dev/null
+++ b/utils/keytable/bpf.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+
+/*
+ * common eBPF ELF operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not,  see <http://www.gnu.org/licenses>
+ */
+#ifndef __BPF_BPF_H
+#define __BPF_BPF_H
+
+#include <linux/bpf.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+struct bpf_create_map_attr {
+	const char *name;
+	enum bpf_map_type map_type;
+	__u32 map_flags;
+	__u32 key_size;
+	__u32 value_size;
+	__u32 max_entries;
+	__u32 numa_node;
+	__u32 btf_fd;
+	__u32 btf_key_type_id;
+	__u32 btf_value_type_id;
+	__u32 map_ifindex;
+};
+
+int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr);
+int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
+			int key_size, int value_size, int max_entries,
+			__u32 map_flags, int node);
+int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
+			int key_size, int value_size, int max_entries,
+			__u32 map_flags);
+int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
+		   int max_entries, __u32 map_flags);
+int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
+			       int key_size, int inner_map_fd, int max_entries,
+			       __u32 map_flags, int node);
+int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
+			  int key_size, int inner_map_fd, int max_entries,
+			  __u32 map_flags);
+
+struct bpf_load_program_attr {
+	enum bpf_prog_type prog_type;
+	enum bpf_attach_type expected_attach_type;
+	const char *name;
+	const struct bpf_insn *insns;
+	size_t insns_cnt;
+	const char *license;
+	__u32 kern_version;
+	__u32 prog_ifindex;
+};
+
+/* Recommend log buffer size */
+#define BPF_LOG_BUF_SIZE (256 * 1024)
+int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
+			   char *log_buf, size_t log_buf_sz);
+int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		     size_t insns_cnt, const char *name, const char *license,
+		     __u32 kern_version, char *log_buf,
+		     size_t log_buf_sz);
+int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
+		       size_t insns_cnt, int strict_alignment,
+		       const char *license, __u32 kern_version,
+		       char *log_buf, size_t log_buf_sz, int log_level);
+
+int bpf_map_update_elem(int fd, const void *key, const void *value,
+			__u64 flags);
+
+int bpf_map_lookup_elem(int fd, const void *key, void *value);
+int bpf_map_delete_elem(int fd, const void *key);
+int bpf_map_get_next_key(int fd, const void *key, void *next_key);
+int bpf_obj_pin(int fd, const char *pathname);
+int bpf_obj_get(const char *pathname);
+int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type,
+		    unsigned int flags);
+int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
+int bpf_prog_detach2(int prog_fd, int attachable_fd, enum bpf_attach_type type);
+int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
+		      void *data_out, __u32 *size_out, __u32 *retval,
+		      __u32 *duration);
+int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id);
+int bpf_map_get_next_id(__u32 start_id, __u32 *next_id);
+int bpf_prog_get_fd_by_id(__u32 id);
+int bpf_map_get_fd_by_id(__u32 id);
+int bpf_btf_get_fd_by_id(__u32 id);
+int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
+int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
+		   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt);
+int bpf_raw_tracepoint_open(const char *name, int prog_fd);
+int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
+		 bool do_log);
+#endif
diff --git a/utils/keytable/bpf_load.c b/utils/keytable/bpf_load.c
new file mode 100644
index 00000000..272f9423
--- /dev/null
+++ b/utils/keytable/bpf_load.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <libelf.h>
+#include <gelf.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <linux/bpf.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <assert.h>
+#include "toml.h"
+#include "bpf.h"
+#include "bpf_load.h"
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+struct bpf_file {
+	Elf *elf;
+	char license[128];
+	bool processed_sec[128];
+	int map_fd[MAX_MAPS];
+	struct bpf_map_data map_data[MAX_MAPS];
+	int nr_maps;
+	int maps_shidx;
+	int dataidx;
+	Elf_Data *data;
+	int strtabidx;
+	Elf_Data *symbols;
+	struct toml_table_t *toml;
+};
+
+static int load_and_attach(int lirc_fd, struct bpf_file *bpf_file, const char *name, struct bpf_insn *prog, int size)
+{
+        size_t insns_cnt = size / sizeof(struct bpf_insn);
+	int fd, err;
+
+	fd = bpf_load_program(BPF_PROG_TYPE_LIRC_MODE2, prog, insns_cnt,
+			      name, bpf_file->license, 0,
+			      bpf_log_buf, BPF_LOG_BUF_SIZE);
+	if (fd < 0) {
+		printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
+		return -1;
+	}
+
+	err = bpf_prog_attach(fd, lirc_fd, BPF_LIRC_MODE2, 0);
+	if (err) {
+		printf("bpf_prog_attach: err=%m\n");
+		return -1;
+	}
+	return 0;
+}
+
+static int load_maps(struct bpf_file *bpf_file)
+{
+	struct bpf_map_data *maps = bpf_file->map_data;
+	int i, numa_node;
+
+	for (i = 0; i < bpf_file->nr_maps; i++) {
+		numa_node = maps[i].def.map_flags & BPF_F_NUMA_NODE ?
+			maps[i].def.numa_node : -1;
+
+		if (maps[i].def.type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+		    maps[i].def.type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+			int inner_map_fd = bpf_file->map_fd[maps[i].def.inner_map_idx];
+
+			bpf_file->map_fd[i] = bpf_create_map_in_map_node(
+							maps[i].def.type,
+							maps[i].name,
+							maps[i].def.key_size,
+							inner_map_fd,
+							maps[i].def.max_entries,
+							maps[i].def.map_flags,
+							numa_node);
+		} else {
+			bpf_file->map_fd[i] = bpf_create_map_node(
+							maps[i].def.type,
+							maps[i].name,
+							maps[i].def.key_size,
+							maps[i].def.value_size,
+							maps[i].def.max_entries,
+							maps[i].def.map_flags,
+							numa_node);
+		}
+		if (bpf_file->map_fd[i] < 0) {
+			printf("failed to create a map: %d %s\n",
+			       errno, strerror(errno));
+			return 1;
+		}
+		maps[i].fd = bpf_file->map_fd[i];
+	}
+	return 0;
+}
+
+static int get_sec(Elf *elf, int i, GElf_Ehdr *ehdr, char **shname,
+		   GElf_Shdr *shdr, Elf_Data **data)
+{
+	Elf_Scn *scn;
+
+	scn = elf_getscn(elf, i);
+	if (!scn)
+		return 1;
+
+	if (gelf_getshdr(scn, shdr) != shdr)
+		return 2;
+
+	*shname = elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name);
+	if (!*shname || !shdr->sh_size)
+		return 3;
+
+	*data = elf_getdata(scn, 0);
+	if (!*data || elf_getdata(scn, *data) != NULL)
+		return 4;
+
+	return 0;
+}
+
+static int parse_relo_and_apply(struct bpf_file *bpf_file, GElf_Shdr *shdr,
+				struct bpf_insn *insn, Elf_Data *data)
+{
+	int i, nrels;
+
+	nrels = shdr->sh_size / shdr->sh_entsize;
+
+	for (i = 0; i < nrels; i++) {
+		GElf_Sym sym;
+		GElf_Rel rel;
+		unsigned int insn_idx;
+		const char *sym_name;
+		bool match = false;
+		int map_idx;
+
+		gelf_getrel(data, i, &rel);
+
+		insn_idx = rel.r_offset / sizeof(struct bpf_insn);
+
+		gelf_getsym(bpf_file->symbols, GELF_R_SYM(rel.r_info), &sym);
+
+		sym_name = elf_strptr(bpf_file->elf, bpf_file->strtabidx, sym.st_name);
+
+		if (insn[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
+			printf("invalid relo for insn[%d].code 0x%x\n",
+			       insn_idx, insn[insn_idx].code);
+			return 1;
+		}
+
+		if (sym.st_shndx == bpf_file->maps_shidx) {
+			/* Match FD relocation against recorded map_data[] offset */
+			for (map_idx = 0; map_idx < bpf_file->nr_maps; map_idx++) {
+				if (bpf_file->map_data[map_idx].elf_offset == sym.st_value) {
+					match = true;
+					break;
+				}
+			}
+
+			if (match) {
+		                insn[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+				insn[insn_idx].imm = bpf_file->map_data[map_idx].fd;
+				continue;
+			}
+
+			printf("invalid relo for insn[%d] no map_data match\n",
+			       insn_idx);
+			return 1;
+		}
+		else if (sym.st_shndx == bpf_file->dataidx) {
+			int p_idx = insn_idx + 2;
+			const char *raw = NULL;
+			int64_t value;
+
+			if (insn[p_idx].code != (BPF_MEM | BPF_LDX)) {
+				printf("unexpected code 0x%02x for insn[%d]\n", insn[p_idx].code, p_idx);
+				return 1;
+			}
+
+			if (bpf_file->toml)
+				raw = toml_raw_in(bpf_file->toml, sym_name);
+
+			printf("%s %s\n", sym_name, raw);
+
+			if (raw) {
+				if (toml_rtoi(raw, &value)) {
+					printf("option %s for not a integer: %s\n", sym_name, raw);
+					return 1;
+				}
+			} else {
+				int32_t *p = (bpf_file->data->d_buf + sym.st_value);
+				value = *p;
+			}
+
+			// patch ld to mov immediate
+			insn[p_idx].code = BPF_ALU64 | BPF_MOV | BPF_K;
+			insn[p_idx].imm = value;
+			insn[p_idx].src_reg = 0;
+		} else {
+			printf("symbol %s has unknown section %d\n", sym_name, sym.st_shndx);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static int cmp_symbols(const void *l, const void *r)
+{
+	const GElf_Sym *lsym = (const GElf_Sym *)l;
+	const GElf_Sym *rsym = (const GElf_Sym *)r;
+
+	if (lsym->st_value < rsym->st_value)
+		return -1;
+	else if (lsym->st_value > rsym->st_value)
+		return 1;
+	else
+		return 0;
+}
+
+static int load_elf_maps_section(struct bpf_file *bpf_file)
+{
+	int map_sz_elf, map_sz_copy;
+	bool validate_zero = false;
+	Elf_Data *data_maps;
+	int i, nr_maps;
+	GElf_Sym *sym;
+	Elf_Scn *scn;
+
+	if (bpf_file->maps_shidx < 0)
+		return -EINVAL;
+	if (!bpf_file->symbols)
+		return -EINVAL;
+
+	/* Get data for maps section via elf index */
+	scn = elf_getscn(bpf_file->elf, bpf_file->maps_shidx);
+	if (scn)
+		data_maps = elf_getdata(scn, NULL);
+	if (!scn || !data_maps) {
+		printf("Failed to get Elf_Data from maps section %d\n",
+		       bpf_file->maps_shidx);
+		return -EINVAL;
+	}
+
+	/* For each map get corrosponding symbol table entry */
+	sym = calloc(MAX_MAPS+1, sizeof(GElf_Sym));
+	for (i = 0, nr_maps = 0; i < bpf_file->symbols->d_size / sizeof(GElf_Sym); i++) {
+		assert(nr_maps < MAX_MAPS+1);
+		if (!gelf_getsym(bpf_file->symbols, i, &sym[nr_maps]))
+			continue;
+		if (sym[nr_maps].st_shndx != bpf_file->maps_shidx)
+			continue;
+		/* Only increment iif maps section */
+		nr_maps++;
+	}
+
+	/* Align to map_fd[] order, via sort on offset in sym.st_value */
+	qsort(sym, nr_maps, sizeof(GElf_Sym), cmp_symbols);
+
+	/* Keeping compatible with ELF maps section changes
+	 * ------------------------------------------------
+	 * The program size of struct bpf_load_map_def is known by loader
+	 * code, but struct stored in ELF file can be different.
+	 *
+	 * Unfortunately sym[i].st_size is zero.  To calculate the
+	 * struct size stored in the ELF file, assume all struct have
+	 * the same size, and simply divide with number of map
+	 * symbols.
+	 */
+	map_sz_elf = data_maps->d_size / nr_maps;
+	map_sz_copy = sizeof(struct bpf_load_map_def);
+	if (map_sz_elf < map_sz_copy) {
+		/*
+		 * Backward compat, loading older ELF file with
+		 * smaller struct, keeping remaining bytes zero.
+		 */
+		map_sz_copy = map_sz_elf;
+	} else if (map_sz_elf > map_sz_copy) {
+		/*
+		 * Forward compat, loading newer ELF file with larger
+		 * struct with unknown features. Assume zero means
+		 * feature not used.  Thus, validate rest of struct
+		 * data is zero.
+		 */
+		validate_zero = true;
+	}
+
+	/* Memcpy relevant part of ELF maps data to loader maps */
+	for (i = 0; i < nr_maps; i++) {
+		struct bpf_load_map_def *def;
+		unsigned char *addr, *end;
+		const char *map_name;
+		struct bpf_map_data *maps = bpf_file->map_data;
+		size_t offset;
+
+		map_name = elf_strptr(bpf_file->elf, bpf_file->strtabidx, sym[i].st_name);
+		maps[i].name = strdup(map_name);
+		if (!maps[i].name) {
+			printf("strdup(%s): %s(%d)\n", map_name,
+			       strerror(errno), errno);
+			free(sym);
+			return -errno;
+		}
+
+		/* Symbol value is offset into ELF maps section data area */
+		offset = sym[i].st_value;
+		def = (struct bpf_load_map_def *)(data_maps->d_buf + offset);
+		maps[i].elf_offset = offset;
+		memset(&maps[i].def, 0, sizeof(struct bpf_load_map_def));
+		memcpy(&maps[i].def, def, map_sz_copy);
+
+		/* Verify no newer features were requested */
+		if (validate_zero) {
+			addr = (unsigned char*) def + map_sz_copy;
+			end  = (unsigned char*) def + map_sz_elf;
+			for (; addr < end; addr++) {
+				if (*addr != 0) {
+					free(sym);
+					return -EFBIG;
+				}
+			}
+		}
+	}
+
+	free(sym);
+	return nr_maps;
+}
+
+int load_bpf_file(const char *path, int lirc_fd, struct toml_table_t *toml)
+{
+	struct bpf_file bpf_file = { .toml = toml };
+	int fd, i, ret;
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr, shdr_prog;
+	Elf_Data *data, *data_prog, *data_map = NULL;
+	char *shname, *shname_prog;
+	int nr_maps = 0;
+
+	if (elf_version(EV_CURRENT) == EV_NONE)
+		return 1;
+
+	fd = open(path, O_RDONLY, 0);
+	if (fd < 0)
+		return 1;
+
+	elf = elf_begin(fd, ELF_C_READ, NULL);
+
+	if (!elf)
+		return 1;
+
+	if (gelf_getehdr(elf, &ehdr) != &ehdr)
+		return 1;
+
+	bpf_file.elf = elf;
+
+	/* scan over all elf sections to get license and map info */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (0) /* helpful for llvm debugging */
+			printf("section %d:%s data %p size %zd link %d flags %d\n",
+			       i, shname, data->d_buf, data->d_size,
+			       shdr.sh_link, (int) shdr.sh_flags);
+
+		if (strcmp(shname, "license") == 0) {
+			bpf_file.processed_sec[i] = true;
+			memcpy(bpf_file.license, data->d_buf, data->d_size);
+		} else if (strcmp(shname, "maps") == 0) {
+			int j;
+
+			bpf_file.maps_shidx = i;
+			data_map = data;
+			for (j = 0; j < MAX_MAPS; j++)
+				bpf_file.map_data[j].fd = -1;
+		} else if (strcmp(shname, ".data") == 0) {
+			bpf_file.dataidx = i;
+			bpf_file.data = data;
+		} else if (shdr.sh_type == SHT_SYMTAB) {
+			bpf_file.strtabidx = shdr.sh_link;
+			bpf_file.symbols = data;
+		}
+	}
+
+	ret = 1;
+
+	if (!bpf_file.symbols) {
+		printf("missing SHT_SYMTAB section\n");
+		goto done;
+	}
+
+	if (data_map) {
+		bpf_file.nr_maps = load_elf_maps_section(&bpf_file);
+		if (bpf_file.nr_maps < 0) {
+			printf("Error: Failed loading ELF maps (errno:%d):%s\n",
+			       nr_maps, strerror(-nr_maps));
+			goto done;
+		}
+		if (load_maps(&bpf_file))
+			goto done;
+
+		bpf_file.processed_sec[bpf_file.maps_shidx] = true;
+	}
+
+	/* process all relo sections, and rewrite bpf insns for maps */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+		if (bpf_file.processed_sec[i])
+			continue;
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (shdr.sh_type == SHT_REL) {
+			struct bpf_insn *insns;
+
+			/* locate prog sec that need map fixup (relocations) */
+			if (get_sec(elf, shdr.sh_info, &ehdr, &shname_prog,
+				    &shdr_prog, &data_prog))
+				continue;
+
+			if (shdr_prog.sh_type != SHT_PROGBITS ||
+			    !(shdr_prog.sh_flags & SHF_EXECINSTR))
+				continue;
+
+			insns = (struct bpf_insn *) data_prog->d_buf;
+			bpf_file.processed_sec[i] = true; /* relo section */
+
+			if (parse_relo_and_apply(&bpf_file, &shdr, insns, data))
+				continue;
+		}
+	}
+
+	/* load programs */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+		if (bpf_file.processed_sec[i])
+			continue;
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (shdr.sh_type != SHT_PROGBITS ||
+		    !(shdr.sh_flags & SHF_EXECINSTR))
+			continue;
+
+		ret = load_and_attach(lirc_fd, &bpf_file, shname, data->d_buf,
+				      data->d_size);
+		break;
+	}
+
+done:
+	close(fd);
+	return ret;
+}
+
diff --git a/utils/keytable/bpf_load.h b/utils/keytable/bpf_load.h
new file mode 100644
index 00000000..01c7d4fd
--- /dev/null
+++ b/utils/keytable/bpf_load.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BPF_LOAD_H
+#define __BPF_LOAD_H
+
+#define BPF_LOG_BUF_SIZE (256 * 1024)
+
+#define MAX_MAPS 32
+#define MAX_PROGS 64
+
+struct bpf_load_map_def {
+	unsigned int type;
+	unsigned int key_size;
+	unsigned int value_size;
+	unsigned int max_entries;
+	unsigned int map_flags;
+	unsigned int inner_map_idx;
+	unsigned int numa_node;
+};
+
+struct bpf_map_data {
+	int fd;
+	char *name;
+	size_t elf_offset;
+	struct bpf_load_map_def def;
+};
+
+/* parses elf file compiled by llvm .c->.o
+ * . parses 'maps' section and creates maps via BPF syscall
+ * . parses 'license' section and passes it to syscall
+ * . parses elf relocations for BPF maps and adjusts BPF_LD_IMM64 insns by
+ *   storing map_fd into insn->imm and marking such insns as BPF_PSEUDO_MAP_FD
+ * . loads eBPF programs via BPF syscall
+ *
+ * One ELF file can contain multiple BPF programs which will be loaded
+ * and their FDs stored stored in prog_fd array
+ *
+ * returns zero on success
+ */
+int load_bpf_file(const char *path, int lirc_fd, struct toml_table_t *toml);
+
+#endif
diff --git a/utils/keytable/keytable.c b/utils/keytable/keytable.c
index c6304b04..2cef9f58 100644
--- a/utils/keytable/keytable.c
+++ b/utils/keytable/keytable.c
@@ -34,6 +34,8 @@
 #include "ir-encode.h"
 #include "parse.h"
 #include "toml.h"
+#include "bpf.h"
+#include "bpf_load.h"
 
 #ifdef ENABLE_NLS
 # define _(string) gettext(string)
@@ -56,6 +58,10 @@ struct input_keymap_entry_v2 {
 	u_int8_t  scancode[32];
 };
 
+
+#define IR_PROTOCOLS_USER_DIR IR_KEYTABLE_USER_DIR "/protocols"
+#define IR_PROTOCOLS_SYSTEM_DIR IR_KEYTABLE_SYSTEM_DIR "/protocols"
+
 #ifndef EVIOCSCLOCKID
 #define EVIOCSCLOCKID		_IOW('E', 0xa0, int)
 #endif
@@ -265,6 +271,14 @@ static int delay = -1;
 static int period = -1;
 static enum sysfs_protocols ch_proto = 0;
 
+struct bpf_protocol {
+	struct bpf_protocol *next;
+	struct toml_table_t *toml;
+	char *name;
+};
+
+static struct bpf_protocol *bpf_protocol;
+
 struct cfgfile cfg = {
 	NULL, NULL, NULL, NULL
 };
@@ -407,15 +421,22 @@ static error_t parse_toml_protocol(struct toml_table_t *root, const char *p)
 	const char *raw;
 	int i = 0;
 
+	proot = toml_table_in(root, p);
+
 	protocol = parse_sysfs_protocol(p, false);
 	if (protocol == SYSFS_INVALID) {
-		fprintf(stderr, _("Protocol `%s' not known\n"), p);
-		return EINVAL;
-	}
+		struct bpf_protocol *b;
 
-	ch_proto |= protocol;
+		b = malloc(sizeof(*b));
+		b->name = strdup(p);
+		b->toml = proot;
+		b->next = bpf_protocol;
+		bpf_protocol = b;
+	}
+	else {
+		ch_proto |= protocol;
+	}
 
-	proot = toml_table_in(root, p);
 	if (!proot) {
 		if (debug)
 			fprintf(stderr, _("No [%s] section"), p);
@@ -551,7 +572,8 @@ static error_t parse_toml_keyfile(char *fname, char **table)
 		}
 	}
 
-	toml_free(root);
+	// Don't free toml, this is used during bpf loading */
+	//toml_free(root);
 	return 0;
 out:
 	toml_free(root);
@@ -1739,6 +1761,146 @@ static void device_info(int fd, char *prepend)
 		perror ("EVIOCGID");
 }
 
+#ifdef HAVE_LIBELF
+#define MAX_PROGS 64
+static void attach_bpf(const char *lirc_name, const char *bpf_prog, struct toml_table_t *toml)
+{
+	unsigned int features;
+	int fd;
+
+	fd = open(lirc_name, O_RDONLY);
+	if (fd == -1) {
+		perror(lirc_name);
+		return;
+	}
+
+	if (ioctl(fd, LIRC_GET_FEATURES, &features)) {
+		perror(lirc_name);
+		close(fd);
+		return;
+	}
+
+	if (!(features & LIRC_CAN_REC_MODE2)) {
+		fprintf(stderr, "%s: only raw IR devices support bpf\n",
+			lirc_name);
+		close(fd);
+		return;
+	}
+
+	load_bpf_file(bpf_prog, fd, toml);
+	close(fd);
+}
+
+static void show_bpf(const char *lirc_name)
+{
+	unsigned int prog_ids[MAX_PROGS], count = MAX_PROGS;
+	unsigned int features, i;
+	int ret, fd, prog_fd;
+
+	fd = open(lirc_name, O_RDONLY);
+	if (fd == -1) {
+		printf("\tAttached bpf protocols: %m\n");
+		return;
+	}
+
+	if (ioctl(fd, LIRC_GET_FEATURES, &features)) {
+		printf("\tAttached bpf protocols: %m\n");
+		close(fd);
+		return;
+	}
+
+	if (!(features & LIRC_CAN_REC_MODE2)) {
+		// only support for mode2 type raw ir devices
+		close(fd);
+		return;
+	}
+
+	ret = bpf_prog_query(fd, BPF_LIRC_MODE2, 0, NULL, prog_ids, &count);
+	close(fd);
+	if (ret) {
+		if (errno == EINVAL)
+			printf("\tAttached bpf protocols: No kernel support\n");
+		else
+			printf("\tAttached bpf protocols: %m\n");
+		return;
+	}
+
+	printf("\tAttached bpf protocols: ");
+	for (i=0; i<count; i++) {
+		if (i)
+			printf(" ");
+		prog_fd = bpf_prog_get_fd_by_id(prog_ids[i]);
+		if (prog_fd != -1) {
+			struct bpf_prog_info info = {};
+			__u32 info_len = sizeof(info);
+
+			ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+			close(prog_fd);
+			if (!ret && info.name[0]) {
+				printf("%s", info.name);
+				continue;
+			}
+		}
+		printf("%d", prog_ids[i]);
+	}
+	printf("\n");
+}
+
+static void clear_bpf(const char *lirc_name)
+{
+	unsigned int prog_ids[MAX_PROGS], count = MAX_PROGS;
+	unsigned int features, i;
+	int ret, prog_fd, fd;
+
+	fd = open(lirc_name, O_RDONLY);
+	if (fd == -1) {
+		perror(lirc_name);
+		return;
+	}
+
+	if (ioctl(fd, LIRC_GET_FEATURES, &features)) {
+		perror(lirc_name);
+		close(fd);
+		return;
+	}
+
+	if (!(features & LIRC_CAN_REC_MODE2)) {
+		// only support for mode2 type raw ir devices
+		close(fd);
+		return;
+	}
+
+	ret = bpf_prog_query(fd, BPF_LIRC_MODE2, 0, NULL, prog_ids, &count);
+	if (ret) {
+		close(fd);
+		return;
+	}
+
+	for (i = 0; i < count; i++) {
+		prog_fd = bpf_prog_get_fd_by_id(prog_ids[i]);
+		if (prog_fd == -1) {
+			printf("failed to get bpf prog id %u: %m\n",
+			       prog_ids[i]);
+			continue;
+		}
+		ret = bpf_prog_detach2(prog_fd, fd, BPF_LIRC_MODE2);
+		if (ret)
+			printf("failed to detach bpf prog id %u: %m\n",
+			       prog_ids[i]);
+		close(prog_fd);
+	}
+	close(fd);
+	fprintf(stderr, _("bpf protocols removed\n"));
+}
+#else
+static void attach_bpf(const char *lirc_name, const char *bpf_prog)
+{
+	fprintf(stderr, _("error: ir-keytable was compiled without BPF support\n"));
+}
+static void show_bpf(const char *lirc_name) {}
+static void clear_bpf(const char *lirc_name) {}
+#endif
+
 static int show_sysfs_attribs(struct rc_device *rc_dev, char *name)
 {
 	static struct sysfs_names *names, *cur;
@@ -1760,9 +1922,11 @@ static int show_sysfs_attribs(struct rc_device *rc_dev, char *name)
 			fprintf(stderr, _("\tDriver: %s, table: %s\n"),
 				rc_dev->drv_name,
 				rc_dev->keytable_name);
-			if (rc_dev->lirc_name)
+			if (rc_dev->lirc_name) {
 				fprintf(stderr, _("\tlirc device: %s\n"),
 					rc_dev->lirc_name);
+				show_bpf(rc_dev->lirc_name);
+			}
 			fprintf(stderr, _("\tSupported protocols: "));
 			write_sysfs_protocols(rc_dev->supported, stderr, "%s ");
 			fprintf(stderr, "\n\t");
@@ -1911,6 +2075,8 @@ int main(int argc, char *argv[])
 	 */
 	if (clear) {
 		clear_table(fd);
+		if (rc_dev.lirc_name)
+			clear_bpf(rc_dev.lirc_name);
 		fprintf(stderr, _("Old keytable cleared\n"));
 	}
 
@@ -1935,6 +2101,34 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	if (bpf_protocol) {
+		struct bpf_protocol *b;
+		struct stat st;
+		char *fname;
+
+		if (!rc_dev.lirc_name) {
+			fprintf(stderr, "Error: unable to attach bpf program, lirc device name was not found\n");
+		}
+
+		for (b = bpf_protocol; b && rc_dev.lirc_name; b = b->next) {
+			asprintf(&fname, IR_PROTOCOLS_USER_DIR "/%s.o", b->name);
+
+			if (stat(fname, &st)) {
+				free(fname);
+				asprintf(&fname, IR_PROTOCOLS_SYSTEM_DIR "/%s.o", b->name);
+
+				if (stat(fname, &st)) {
+					fprintf(stderr, _("Can't find %s bpf protocol in %s or %s\n"), b->name, IR_KEYTABLE_USER_DIR "/protocols", IR_KEYTABLE_SYSTEM_DIR "/protocols");
+					free(fname);
+					continue;
+				}
+			}
+
+			attach_bpf(rc_dev.lirc_name, fname, b->toml);
+			free(fname);
+		}
+	}
+
 	/*
 	 * Fourth step: display current keytable
 	 */
diff --git a/v4l-utils.spec.in b/v4l-utils.spec.in
index bdbb27ba..f7be08b3 100644
--- a/v4l-utils.spec.in
+++ b/v4l-utils.spec.in
@@ -10,7 +10,7 @@ Source0:        http://linuxtv.org/downloads/v4l-utils/v4l-utils-%{version}.tar.
 Source1:        qv4l2.desktop
 Source2:        qv4l2.svg
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
-BuildRequires:  qt4-devel libsysfs-devel kernel-headers desktop-file-utils
+BuildRequires:  qt4-devel libsysfs-devel kernel-headers desktop-file-utils elfutils-libelf-devel
 # For /etc/udev/rules.d ownership
 Requires:       udev
 Requires:       libv4l = %{version}-%{release}
