Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 2166 insertions, 0 deletions

diff --git a/net/bpf/Makefile b/net/bpf/Makefile
new file mode 100644
index 000000000..1ebe270bd
--- /dev/null
+++ b/net/bpf/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_BPF_SYSCALL)	:= test_run.o
+ifeq ($(CONFIG_BPF_JIT),y)
+obj-$(CONFIG_BPF_SYSCALL)	+= bpf_dummy_struct_ops.o
+endif
diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c
new file mode 100644
index 000000000..e78dadfc5
--- /dev/null
+++ b/net/bpf/bpf_dummy_struct_ops.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021. Huawei Technologies Co., Ltd
+ */
+#include <linux/kernel.h>
+#include <linux/bpf_verifier.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+
+extern struct bpf_struct_ops bpf_bpf_dummy_ops;
+
+/* A common type for test_N with return value in bpf_dummy_ops */
+typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...);
+
+struct bpf_dummy_ops_test_args {
+	u64 args[MAX_BPF_FUNC_ARGS];
+	struct bpf_dummy_ops_state state;
+};
+
+static struct bpf_dummy_ops_test_args *
+dummy_ops_init_args(const union bpf_attr *kattr, unsigned int nr)
+{
+	__u32 size_in;
+	struct bpf_dummy_ops_test_args *args;
+	void __user *ctx_in;
+	void __user *u_state;
+
+	size_in = kattr->test.ctx_size_in;
+	if (size_in != sizeof(u64) * nr)
+		return ERR_PTR(-EINVAL);
+
+	args = kzalloc(sizeof(*args), GFP_KERNEL);
+	if (!args)
+		return ERR_PTR(-ENOMEM);
+
+	ctx_in = u64_to_user_ptr(kattr->test.ctx_in);
+	if (copy_from_user(args->args, ctx_in, size_in))
+		goto out;
+
+	/* args[0] is 0 means state argument of test_N will be NULL */
+	u_state = u64_to_user_ptr(args->args[0]);
+	if (u_state && copy_from_user(&args->state, u_state,
+				      sizeof(args->state)))
+		goto out;
+
+	return args;
+out:
+	kfree(args);
+	return ERR_PTR(-EFAULT);
+}
+
+static int dummy_ops_copy_args(struct bpf_dummy_ops_test_args *args)
+{
+	void __user *u_state;
+
+	u_state = u64_to_user_ptr(args->args[0]);
+	if (u_state && copy_to_user(u_state, &args->state, sizeof(args->state)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int dummy_ops_call_op(void *image, struct bpf_dummy_ops_test_args *args)
+{
+	dummy_ops_test_ret_fn test = (void *)image;
+	struct bpf_dummy_ops_state *state = NULL;
+
+	/* state needs to be NULL if args[0] is 0 */
+	if (args->args[0])
+		state = &args->state;
+	return test(state, args->args[1], args->args[2],
+		    args->args[3], args->args[4]);
+}
+
+extern const struct bpf_link_ops bpf_struct_ops_link_lops;
+
+int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
+			    union bpf_attr __user *uattr)
+{
+	const struct bpf_struct_ops *st_ops = &bpf_bpf_dummy_ops;
+	const struct btf_type *func_proto;
+	struct bpf_dummy_ops_test_args *args;
+	struct bpf_tramp_links *tlinks;
+	struct bpf_tramp_link *link = NULL;
+	void *image = NULL;
+	unsigned int op_idx;
+	int prog_ret;
+	int err;
+
+	if (prog->aux->attach_btf_id != st_ops->type_id)
+		return -EOPNOTSUPP;
+
+	func_proto = prog->aux->attach_func_proto;
+	args = dummy_ops_init_args(kattr, btf_type_vlen(func_proto));
+	if (IS_ERR(args))
+		return PTR_ERR(args);
+
+	tlinks = kcalloc(BPF_TRAMP_MAX, sizeof(*tlinks), GFP_KERNEL);
+	if (!tlinks) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	image = bpf_jit_alloc_exec(PAGE_SIZE);
+	if (!image) {
+		err = -ENOMEM;
+		goto out;
+	}
+	set_vm_flush_reset_perms(image);
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto out;
+	}
+	/* prog doesn't take the ownership of the reference from caller */
+	bpf_prog_inc(prog);
+	bpf_link_init(&link->link, BPF_LINK_TYPE_STRUCT_OPS, &bpf_struct_ops_link_lops, prog);
+
+	op_idx = prog->expected_attach_type;
+	err = bpf_struct_ops_prepare_trampoline(tlinks, link,
+						&st_ops->func_models[op_idx],
+						image, image + PAGE_SIZE);
+	if (err < 0)
+		goto out;
+
+	set_memory_ro((long)image, 1);
+	set_memory_x((long)image, 1);
+	prog_ret = dummy_ops_call_op(image, args);
+
+	err = dummy_ops_copy_args(args);
+	if (err)
+		goto out;
+	if (put_user(prog_ret, &uattr->test.retval))
+		err = -EFAULT;
+out:
+	kfree(args);
+	bpf_jit_free_exec(image);
+	if (link)
+		bpf_link_put(&link->link);
+	kfree(tlinks);
+	return err;
+}
+
+static int bpf_dummy_init(struct btf *btf)
+{
+	return 0;
+}
+
+static bool bpf_dummy_ops_is_valid_access(int off, int size,
+					  enum bpf_access_type type,
+					  const struct bpf_prog *prog,
+					  struct bpf_insn_access_aux *info)
+{
+	return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
+}
+
+static int bpf_dummy_ops_btf_struct_access(struct bpf_verifier_log *log,
+					   const struct btf *btf,
+					   const struct btf_type *t, int off,
+					   int size, enum bpf_access_type atype,
+					   u32 *next_btf_id,
+					   enum bpf_type_flag *flag)
+{
+	const struct btf_type *state;
+	s32 type_id;
+	int err;
+
+	type_id = btf_find_by_name_kind(btf, "bpf_dummy_ops_state",
+					BTF_KIND_STRUCT);
+	if (type_id < 0)
+		return -EINVAL;
+
+	state = btf_type_by_id(btf, type_id);
+	if (t != state) {
+		bpf_log(log, "only access to bpf_dummy_ops_state is supported\n");
+		return -EACCES;
+	}
+
+	err = btf_struct_access(log, btf, t, off, size, atype, next_btf_id,
+				flag);
+	if (err < 0)
+		return err;
+
+	return atype == BPF_READ ? err : NOT_INIT;
+}
+
+static const struct bpf_verifier_ops bpf_dummy_verifier_ops = {
+	.is_valid_access = bpf_dummy_ops_is_valid_access,
+	.btf_struct_access = bpf_dummy_ops_btf_struct_access,
+};
+
+static int bpf_dummy_init_member(const struct btf_type *t,
+				 const struct btf_member *member,
+				 void *kdata, const void *udata)
+{
+	return -EOPNOTSUPP;
+}
+
+static int bpf_dummy_reg(void *kdata)
+{
+	return -EOPNOTSUPP;
+}
+
+static void bpf_dummy_unreg(void *kdata)
+{
+}
+
+struct bpf_struct_ops bpf_bpf_dummy_ops = {
+	.verifier_ops = &bpf_dummy_verifier_ops,
+	.init = bpf_dummy_init,
+	.init_member = bpf_dummy_init_member,
+	.reg = bpf_dummy_reg,
+	.unreg = bpf_dummy_unreg,
+	.name = "bpf_dummy_ops",
+};
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
new file mode 100644
index 000000000..6094ef7cf
--- /dev/null
+++ b/net/bpf/test_run.c
@@ -0,0 +1,1676 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/vmalloc.h>
+#include <linux/etherdevice.h>
+#include <linux/filter.h>
+#include <linux/rcupdate_trace.h>
+#include <linux/sched/signal.h>
+#include <net/bpf_sk_storage.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/net_namespace.h>
+#include <net/page_pool.h>
+#include <linux/error-injection.h>
+#include <linux/smp.h>
+#include <linux/sock_diag.h>
+#include <net/xdp.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/bpf_test_run.h>
+
+struct bpf_test_timer {
+	enum { NO_PREEMPT, NO_MIGRATE } mode;
+	u32 i;
+	u64 time_start, time_spent;
+};
+
+static void bpf_test_timer_enter(struct bpf_test_timer *t)
+	__acquires(rcu)
+{
+	rcu_read_lock();
+	if (t->mode == NO_PREEMPT)
+		preempt_disable();
+	else
+		migrate_disable();
+
+	t->time_start = ktime_get_ns();
+}
+
+static void bpf_test_timer_leave(struct bpf_test_timer *t)
+	__releases(rcu)
+{
+	t->time_start = 0;
+
+	if (t->mode == NO_PREEMPT)
+		preempt_enable();
+	else
+		migrate_enable();
+	rcu_read_unlock();
+}
+
+static bool bpf_test_timer_continue(struct bpf_test_timer *t, int iterations,
+				    u32 repeat, int *err, u32 *duration)
+	__must_hold(rcu)
+{
+	t->i += iterations;
+	if (t->i >= repeat) {
+		/* We're done. */
+		t->time_spent += ktime_get_ns() - t->time_start;
+		do_div(t->time_spent, t->i);
+		*duration = t->time_spent > U32_MAX ? U32_MAX : (u32)t->time_spent;
+		*err = 0;
+		goto reset;
+	}
+
+	if (signal_pending(current)) {
+		/* During iteration: we've been cancelled, abort. */
+		*err = -EINTR;
+		goto reset;
+	}
+
+	if (need_resched()) {
+		/* During iteration: we need to reschedule between runs. */
+		t->time_spent += ktime_get_ns() - t->time_start;
+		bpf_test_timer_leave(t);
+		cond_resched();
+		bpf_test_timer_enter(t);
+	}
+
+	/* Do another round. */
+	return true;
+
+reset:
+	t->i = 0;
+	return false;
+}
+
+/* We put this struct at the head of each page with a context and frame
+ * initialised when the page is allocated, so we don't have to do this on each
+ * repetition of the test run.
+ */
+struct xdp_page_head {
+	struct xdp_buff orig_ctx;
+	struct xdp_buff ctx;
+	struct xdp_frame frm;
+	u8 data[];
+};
+
+struct xdp_test_data {
+	struct xdp_buff *orig_ctx;
+	struct xdp_rxq_info rxq;
+	struct net_device *dev;
+	struct page_pool *pp;
+	struct xdp_frame **frames;
+	struct sk_buff **skbs;
+	struct xdp_mem_info mem;
+	u32 batch_size;
+	u32 frame_cnt;
+};
+
+#define TEST_XDP_FRAME_SIZE (PAGE_SIZE - sizeof(struct xdp_page_head))
+#define TEST_XDP_MAX_BATCH 256
+
+static void xdp_test_run_init_page(struct page *page, void *arg)
+{
+	struct xdp_page_head *head = phys_to_virt(page_to_phys(page));
+	struct xdp_buff *new_ctx, *orig_ctx;
+	u32 headroom = XDP_PACKET_HEADROOM;
+	struct xdp_test_data *xdp = arg;
+	size_t frm_len, meta_len;
+	struct xdp_frame *frm;
+	void *data;
+
+	orig_ctx = xdp->orig_ctx;
+	frm_len = orig_ctx->data_end - orig_ctx->data_meta;
+	meta_len = orig_ctx->data - orig_ctx->data_meta;
+	headroom -= meta_len;
+
+	new_ctx = &head->ctx;
+	frm = &head->frm;
+	data = &head->data;
+	memcpy(data + headroom, orig_ctx->data_meta, frm_len);
+
+	xdp_init_buff(new_ctx, TEST_XDP_FRAME_SIZE, &xdp->rxq);
+	xdp_prepare_buff(new_ctx, data, headroom, frm_len, true);
+	new_ctx->data = new_ctx->data_meta + meta_len;
+
+	xdp_update_frame_from_buff(new_ctx, frm);
+	frm->mem = new_ctx->rxq->mem;
+
+	memcpy(&head->orig_ctx, new_ctx, sizeof(head->orig_ctx));
+}
+
+static int xdp_test_run_setup(struct xdp_test_data *xdp, struct xdp_buff *orig_ctx)
+{
+	struct page_pool *pp;
+	int err = -ENOMEM;
+	struct page_pool_params pp_params = {
+		.order = 0,
+		.flags = 0,
+		.pool_size = xdp->batch_size,
+		.nid = NUMA_NO_NODE,
+		.init_callback = xdp_test_run_init_page,
+		.init_arg = xdp,
+	};
+
+	xdp->frames = kvmalloc_array(xdp->batch_size, sizeof(void *), GFP_KERNEL);
+	if (!xdp->frames)
+		return -ENOMEM;
+
+	xdp->skbs = kvmalloc_array(xdp->batch_size, sizeof(void *), GFP_KERNEL);
+	if (!xdp->skbs)
+		goto err_skbs;
+
+	pp = page_pool_create(&pp_params);
+	if (IS_ERR(pp)) {
+		err = PTR_ERR(pp);
+		goto err_pp;
+	}
+
+	/* will copy 'mem.id' into pp->xdp_mem_id */
+	err = xdp_reg_mem_model(&xdp->mem, MEM_TYPE_PAGE_POOL, pp);
+	if (err)
+		goto err_mmodel;
+
+	xdp->pp = pp;
+
+	/* We create a 'fake' RXQ referencing the original dev, but with an
+	 * xdp_mem_info pointing to our page_pool
+	 */
+	xdp_rxq_info_reg(&xdp->rxq, orig_ctx->rxq->dev, 0, 0);
+	xdp->rxq.mem.type = MEM_TYPE_PAGE_POOL;
+	xdp->rxq.mem.id = pp->xdp_mem_id;
+	xdp->dev = orig_ctx->rxq->dev;
+	xdp->orig_ctx = orig_ctx;
+
+	return 0;
+
+err_mmodel:
+	page_pool_destroy(pp);
+err_pp:
+	kvfree(xdp->skbs);
+err_skbs:
+	kvfree(xdp->frames);
+	return err;
+}
+
+static void xdp_test_run_teardown(struct xdp_test_data *xdp)
+{
+	xdp_unreg_mem_model(&xdp->mem);
+	page_pool_destroy(xdp->pp);
+	kfree(xdp->frames);
+	kfree(xdp->skbs);
+}
+
+static bool ctx_was_changed(struct xdp_page_head *head)
+{
+	return head->orig_ctx.data != head->ctx.data ||
+		head->orig_ctx.data_meta != head->ctx.data_meta ||
+		head->orig_ctx.data_end != head->ctx.data_end;
+}
+
+static void reset_ctx(struct xdp_page_head *head)
+{
+	if (likely(!ctx_was_changed(head)))
+		return;
+
+	head->ctx.data = head->orig_ctx.data;
+	head->ctx.data_meta = head->orig_ctx.data_meta;
+	head->ctx.data_end = head->orig_ctx.data_end;
+	xdp_update_frame_from_buff(&head->ctx, &head->frm);
+}
+
+static int xdp_recv_frames(struct xdp_frame **frames, int nframes,
+			   struct sk_buff **skbs,
+			   struct net_device *dev)
+{
+	gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
+	int i, n;
+	LIST_HEAD(list);
+
+	n = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, (void **)skbs);
+	if (unlikely(n == 0)) {
+		for (i = 0; i < nframes; i++)
+			xdp_return_frame(frames[i]);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < nframes; i++) {
+		struct xdp_frame *xdpf = frames[i];
+		struct sk_buff *skb = skbs[i];
+
+		skb = __xdp_build_skb_from_frame(xdpf, skb, dev);
+		if (!skb) {
+			xdp_return_frame(xdpf);
+			continue;
+		}
+
+		list_add_tail(&skb->list, &list);
+	}
+	netif_receive_skb_list(&list);
+
+	return 0;
+}
+
+static int xdp_test_run_batch(struct xdp_test_data *xdp, struct bpf_prog *prog,
+			      u32 repeat)
+{
+	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+	int err = 0, act, ret, i, nframes = 0, batch_sz;
+	struct xdp_frame **frames = xdp->frames;
+	struct xdp_page_head *head;
+	struct xdp_frame *frm;
+	bool redirect = false;
+	struct xdp_buff *ctx;
+	struct page *page;
+
+	batch_sz = min_t(u32, repeat, xdp->batch_size);
+
+	local_bh_disable();
+	xdp_set_return_frame_no_direct();
+
+	for (i = 0; i < batch_sz; i++) {
+		page = page_pool_dev_alloc_pages(xdp->pp);
+		if (!page) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		head = phys_to_virt(page_to_phys(page));
+		reset_ctx(head);
+		ctx = &head->ctx;
+		frm = &head->frm;
+		xdp->frame_cnt++;
+
+		act = bpf_prog_run_xdp(prog, ctx);
+
+		/* if program changed pkt bounds we need to update the xdp_frame */
+		if (unlikely(ctx_was_changed(head))) {
+			ret = xdp_update_frame_from_buff(ctx, frm);
+			if (ret) {
+				xdp_return_buff(ctx);
+				continue;
+			}
+		}
+
+		switch (act) {
+		case XDP_TX:
+			/* we can't do a real XDP_TX since we're not in the
+			 * driver, so turn it into a REDIRECT back to the same
+			 * index
+			 */
+			ri->tgt_index = xdp->dev->ifindex;
+			ri->map_id = INT_MAX;
+			ri->map_type = BPF_MAP_TYPE_UNSPEC;
+			fallthrough;
+		case XDP_REDIRECT:
+			redirect = true;
+			ret = xdp_do_redirect_frame(xdp->dev, ctx, frm, prog);
+			if (ret)
+				xdp_return_buff(ctx);
+			break;
+		case XDP_PASS:
+			frames[nframes++] = frm;
+			break;
+		default:
+			bpf_warn_invalid_xdp_action(NULL, prog, act);
+			fallthrough;
+		case XDP_DROP:
+			xdp_return_buff(ctx);
+			break;
+		}
+	}
+
+out:
+	if (redirect)
+		xdp_do_flush();
+	if (nframes) {
+		ret = xdp_recv_frames(frames, nframes, xdp->skbs, xdp->dev);
+		if (ret)
+			err = ret;
+	}
+
+	xdp_clear_return_frame_no_direct();
+	local_bh_enable();
+	return err;
+}
+
+static int bpf_test_run_xdp_live(struct bpf_prog *prog, struct xdp_buff *ctx,
+				 u32 repeat, u32 batch_size, u32 *time)
+
+{
+	struct xdp_test_data xdp = { .batch_size = batch_size };
+	struct bpf_test_timer t = { .mode = NO_MIGRATE };
+	int ret;
+
+	if (!repeat)
+		repeat = 1;
+
+	ret = xdp_test_run_setup(&xdp, ctx);
+	if (ret)
+		return ret;
+
+	bpf_test_timer_enter(&t);
+	do {
+		xdp.frame_cnt = 0;
+		ret = xdp_test_run_batch(&xdp, prog, repeat - t.i);
+		if (unlikely(ret < 0))
+			break;
+	} while (bpf_test_timer_continue(&t, xdp.frame_cnt, repeat, &ret, time));
+	bpf_test_timer_leave(&t);
+
+	xdp_test_run_teardown(&xdp);
+	return ret;
+}
+
+static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
+			u32 *retval, u32 *time, bool xdp)
+{
+	struct bpf_prog_array_item item = {.prog = prog};
+	struct bpf_run_ctx *old_ctx;
+	struct bpf_cg_run_ctx run_ctx;
+	struct bpf_test_timer t = { NO_MIGRATE };
+	enum bpf_cgroup_storage_type stype;
+	int ret;
+
+	for_each_cgroup_storage_type(stype) {
+		item.cgroup_storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
+		if (IS_ERR(item.cgroup_storage[stype])) {
+			item.cgroup_storage[stype] = NULL;
+			for_each_cgroup_storage_type(stype)
+				bpf_cgroup_storage_free(item.cgroup_storage[stype]);
+			return -ENOMEM;
+		}
+	}
+
+	if (!repeat)
+		repeat = 1;
+
+	bpf_test_timer_enter(&t);
+	old_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
+	do {
+		run_ctx.prog_item = &item;
+		if (xdp)
+			*retval = bpf_prog_run_xdp(prog, ctx);
+		else
+			*retval = bpf_prog_run(prog, ctx);
+	} while (bpf_test_timer_continue(&t, 1, repeat, &ret, time));
+	bpf_reset_run_ctx(old_ctx);
+	bpf_test_timer_leave(&t);
+
+	for_each_cgroup_storage_type(stype)
+		bpf_cgroup_storage_free(item.cgroup_storage[stype]);
+
+	return ret;
+}
+
+static int bpf_test_finish(const union bpf_attr *kattr,
+			   union bpf_attr __user *uattr, const void *data,
+			   struct skb_shared_info *sinfo, u32 size,
+			   u32 retval, u32 duration)
+{
+	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
+	int err = -EFAULT;
+	u32 copy_size = size;
+
+	/* Clamp copy if the user has provided a size hint, but copy the full
+	 * buffer if not to retain old behaviour.
+	 */
+	if (kattr->test.data_size_out &&
+	    copy_size > kattr->test.data_size_out) {
+		copy_size = kattr->test.data_size_out;
+		err = -ENOSPC;
+	}
+
+	if (data_out) {
+		int len = sinfo ? copy_size - sinfo->xdp_frags_size : copy_size;
+
+		if (len < 0) {
+			err = -ENOSPC;
+			goto out;
+		}
+
+		if (copy_to_user(data_out, data, len))
+			goto out;
+
+		if (sinfo) {
+			int i, offset = len;
+			u32 data_len;
+
+			for (i = 0; i < sinfo->nr_frags; i++) {
+				skb_frag_t *frag = &sinfo->frags[i];
+
+				if (offset >= copy_size) {
+					err = -ENOSPC;
+					break;
+				}
+
+				data_len = min_t(u32, copy_size - offset,
+						 skb_frag_size(frag));
+
+				if (copy_to_user(data_out + offset,
+						 skb_frag_address(frag),
+						 data_len))
+					goto out;
+
+				offset += data_len;
+			}
+		}
+	}
+
+	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
+		goto out;
+	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
+		goto out;
+	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
+		goto out;
+	if (err != -ENOSPC)
+		err = 0;
+out:
+	trace_bpf_test_finish(&err);
+	return err;
+}
+
+/* Integer types of various sizes and pointer combinations cover variety of
+ * architecture dependent calling conventions. 7+ can be supported in the
+ * future.
+ */
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+		  "Global functions as their definitions will be in vmlinux BTF");
+int noinline bpf_fentry_test1(int a)
+{
+	return a + 1;
+}
+EXPORT_SYMBOL_GPL(bpf_fentry_test1);
+ALLOW_ERROR_INJECTION(bpf_fentry_test1, ERRNO);
+
+int noinline bpf_fentry_test2(int a, u64 b)
+{
+	return a + b;
+}
+
+int noinline bpf_fentry_test3(char a, int b, u64 c)
+{
+	return a + b + c;
+}
+
+int noinline bpf_fentry_test4(void *a, char b, int c, u64 d)
+{
+	return (long)a + b + c + d;
+}
+
+int noinline bpf_fentry_test5(u64 a, void *b, short c, int d, u64 e)
+{
+	return a + (long)b + c + d + e;
+}
+
+int noinline bpf_fentry_test6(u64 a, void *b, short c, int d, void *e, u64 f)
+{
+	return a + (long)b + c + d + (long)e + f;
+}
+
+struct bpf_fentry_test_t {
+	struct bpf_fentry_test_t *a;
+};
+
+int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
+{
+	return (long)arg;
+}
+
+int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg)
+{
+	return (long)arg->a;
+}
+
+int noinline bpf_modify_return_test(int a, int *b)
+{
+	*b += 1;
+	return a + *b;
+}
+
+u64 noinline bpf_kfunc_call_test1(struct sock *sk, u32 a, u64 b, u32 c, u64 d)
+{
+	return a + b + c + d;
+}
+
+int noinline bpf_kfunc_call_test2(struct sock *sk, u32 a, u32 b)
+{
+	return a + b;
+}
+
+struct sock * noinline bpf_kfunc_call_test3(struct sock *sk)
+{
+	return sk;
+}
+
+struct prog_test_member1 {
+	int a;
+};
+
+struct prog_test_member {
+	struct prog_test_member1 m;
+	int c;
+};
+
+struct prog_test_ref_kfunc {
+	int a;
+	int b;
+	struct prog_test_member memb;
+	struct prog_test_ref_kfunc *next;
+	refcount_t cnt;
+};
+
+static struct prog_test_ref_kfunc prog_test_struct = {
+	.a = 42,
+	.b = 108,
+	.next = &prog_test_struct,
+	.cnt = REFCOUNT_INIT(1),
+};
+
+noinline struct prog_test_ref_kfunc *
+bpf_kfunc_call_test_acquire(unsigned long *scalar_ptr)
+{
+	refcount_inc(&prog_test_struct.cnt);
+	return &prog_test_struct;
+}
+
+noinline struct prog_test_member *
+bpf_kfunc_call_memb_acquire(void)
+{
+	WARN_ON_ONCE(1);
+	return NULL;
+}
+
+noinline void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p)
+{
+	if (!p)
+		return;
+
+	refcount_dec(&p->cnt);
+}
+
+noinline void bpf_kfunc_call_memb_release(struct prog_test_member *p)
+{
+}
+
+noinline void bpf_kfunc_call_memb1_release(struct prog_test_member1 *p)
+{
+	WARN_ON_ONCE(1);
+}
+
+static int *__bpf_kfunc_call_test_get_mem(struct prog_test_ref_kfunc *p, const int size)
+{
+	if (size > 2 * sizeof(int))
+		return NULL;
+
+	return (int *)p;
+}
+
+noinline int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size)
+{
+	return __bpf_kfunc_call_test_get_mem(p, rdwr_buf_size);
+}
+
+noinline int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size)
+{
+	return __bpf_kfunc_call_test_get_mem(p, rdonly_buf_size);
+}
+
+/* the next 2 ones can't be really used for testing expect to ensure
+ * that the verifier rejects the call.
+ * Acquire functions must return struct pointers, so these ones are
+ * failing.
+ */
+noinline int *bpf_kfunc_call_test_acq_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size)
+{
+	return __bpf_kfunc_call_test_get_mem(p, rdonly_buf_size);
+}
+
+noinline void bpf_kfunc_call_int_mem_release(int *p)
+{
+}
+
+noinline struct prog_test_ref_kfunc *
+bpf_kfunc_call_test_kptr_get(struct prog_test_ref_kfunc **pp, int a, int b)
+{
+	struct prog_test_ref_kfunc *p = READ_ONCE(*pp);
+
+	if (!p)
+		return NULL;
+	refcount_inc(&p->cnt);
+	return p;
+}
+
+struct prog_test_pass1 {
+	int x0;
+	struct {
+		int x1;
+		struct {
+			int x2;
+			struct {
+				int x3;
+			};
+		};
+	};
+};
+
+struct prog_test_pass2 {
+	int len;
+	short arr1[4];
+	struct {
+		char arr2[4];
+		unsigned long arr3[8];
+	} x;
+};
+
+struct prog_test_fail1 {
+	void *p;
+	int x;
+};
+
+struct prog_test_fail2 {
+	int x8;
+	struct prog_test_pass1 x;
+};
+
+struct prog_test_fail3 {
+	int len;
+	char arr1[2];
+	char arr2[];
+};
+
+noinline void bpf_kfunc_call_test_pass_ctx(struct __sk_buff *skb)
+{
+}
+
+noinline void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_fail1(struct prog_test_fail1 *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_mem_len_pass1(void *mem, int mem__sz)
+{
+}
+
+noinline void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len)
+{
+}
+
+noinline void bpf_kfunc_call_test_mem_len_fail2(u64 *mem, int len)
+{
+}
+
+noinline void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p)
+{
+}
+
+noinline void bpf_kfunc_call_test_destructive(void)
+{
+}
+
+__diag_pop();
+
+ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO);
+
+BTF_SET8_START(test_sk_check_kfunc_ids)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test2)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test3)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_acquire, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_kfunc_call_memb_acquire, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_kfunc_call_memb_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_kfunc_call_memb1_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_get_rdwr_mem, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_get_rdonly_mem, KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_acq_rdonly_mem, KF_ACQUIRE | KF_RET_NULL)
+BTF_ID_FLAGS(func, bpf_kfunc_call_int_mem_release, KF_RELEASE)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_kptr_get, KF_ACQUIRE | KF_RET_NULL | KF_KPTR_GET)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass_ctx)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass1)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_pass2)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail1)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail2)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_fail3)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE)
+BTF_SET8_END(test_sk_check_kfunc_ids)
+
+static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size,
+			   u32 size, u32 headroom, u32 tailroom)
+{
+	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
+	void *data;
+
+	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
+		return ERR_PTR(-EINVAL);
+
+	if (user_size > size)
+		return ERR_PTR(-EMSGSIZE);
+
+	size = SKB_DATA_ALIGN(size);
+	data = kzalloc(size + headroom + tailroom, GFP_USER);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(data + headroom, data_in, user_size)) {
+		kfree(data);
+		return ERR_PTR(-EFAULT);
+	}
+
+	return data;
+}
+
+int bpf_prog_test_run_tracing(struct bpf_prog *prog,
+			      const union bpf_attr *kattr,
+			      union bpf_attr __user *uattr)
+{
+	struct bpf_fentry_test_t arg = {};
+	u16 side_effect = 0, ret = 0;
+	int b = 2, err = -EFAULT;
+	u32 retval = 0;
+
+	if (kattr->test.flags || kattr->test.cpu || kattr->test.batch_size)
+		return -EINVAL;
+
+	switch (prog->expected_attach_type) {
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+		if (bpf_fentry_test1(1) != 2 ||
+		    bpf_fentry_test2(2, 3) != 5 ||
+		    bpf_fentry_test3(4, 5, 6) != 15 ||
+		    bpf_fentry_test4((void *)7, 8, 9, 10) != 34 ||
+		    bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 ||
+		    bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111 ||
+		    bpf_fentry_test7((struct bpf_fentry_test_t *)0) != 0 ||
+		    bpf_fentry_test8(&arg) != 0)
+			goto out;
+		break;
+	case BPF_MODIFY_RETURN:
+		ret = bpf_modify_return_test(1, &b);
+		if (b != 2)
+			side_effect = 1;
+		break;
+	default:
+		goto out;
+	}
+
+	retval = ((u32)side_effect << 16) | ret;
+	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
+		goto out;
+
+	err = 0;
+out:
+	trace_bpf_test_finish(&err);
+	return err;
+}
+
+struct bpf_raw_tp_test_run_info {
+	struct bpf_prog *prog;
+	void *ctx;
+	u32 retval;
+};
+
+static void
+__bpf_prog_test_run_raw_tp(void *data)
+{
+	struct bpf_raw_tp_test_run_info *info = data;
+
+	rcu_read_lock();
+	info->retval = bpf_prog_run(info->prog, info->ctx);
+	rcu_read_unlock();
+}
+
+int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
+			     const union bpf_attr *kattr,
+			     union bpf_attr __user *uattr)
+{
+	void __user *ctx_in = u64_to_user_ptr(kattr->test.ctx_in);
+	__u32 ctx_size_in = kattr->test.ctx_size_in;
+	struct bpf_raw_tp_test_run_info info;
+	int cpu = kattr->test.cpu, err = 0;
+	int current_cpu;
+
+	/* doesn't support data_in/out, ctx_out, duration, or repeat */
+	if (kattr->test.data_in || kattr->test.data_out ||
+	    kattr->test.ctx_out || kattr->test.duration ||
+	    kattr->test.repeat || kattr->test.batch_size)
+		return -EINVAL;
+
+	if (ctx_size_in < prog->aux->max_ctx_offset ||
+	    ctx_size_in > MAX_BPF_FUNC_ARGS * sizeof(u64))
+		return -EINVAL;
+
+	if ((kattr->test.flags & BPF_F_TEST_RUN_ON_CPU) == 0 && cpu != 0)
+		return -EINVAL;
+
+	if (ctx_size_in) {
+		info.ctx = memdup_user(ctx_in, ctx_size_in);
+		if (IS_ERR(info.ctx))
+			return PTR_ERR(info.ctx);
+	} else {
+		info.ctx = NULL;
+	}
+
+	info.prog = prog;
+
+	current_cpu = get_cpu();
+	if ((kattr->test.flags & BPF_F_TEST_RUN_ON_CPU) == 0 ||
+	    cpu == current_cpu) {
+		__bpf_prog_test_run_raw_tp(&info);
+	} else if (cpu >= nr_cpu_ids || !cpu_online(cpu)) {
+		/* smp_call_function_single() also checks cpu_online()
+		 * after csd_lock(). However, since cpu is from user
+		 * space, let's do an extra quick check to filter out
+		 * invalid value before smp_call_function_single().
+		 */
+		err = -ENXIO;
+	} else {
+		err = smp_call_function_single(cpu, __bpf_prog_test_run_raw_tp,
+					       &info, 1);
+	}
+	put_cpu();
+
+	if (!err &&
+	    copy_to_user(&uattr->test.retval, &info.retval, sizeof(u32)))
+		err = -EFAULT;
+
+	kfree(info.ctx);
+	return err;
+}
+
+static void *bpf_ctx_init(const union bpf_attr *kattr, u32 max_size)
+{
+	void __user *data_in = u64_to_user_ptr(kattr->test.ctx_in);
+	void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
+	u32 size = kattr->test.ctx_size_in;
+	void *data;
+	int err;
+
+	if (!data_in && !data_out)
+		return NULL;
+
+	data = kzalloc(max_size, GFP_USER);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	if (data_in) {
+		err = bpf_check_uarg_tail_zero(USER_BPFPTR(data_in), max_size, size);
+		if (err) {
+			kfree(data);
+			return ERR_PTR(err);
+		}
+
+		size = min_t(u32, max_size, size);
+		if (copy_from_user(data, data_in, size)) {
+			kfree(data);
+			return ERR_PTR(-EFAULT);
+		}
+	}
+	return data;
+}
+
+static int bpf_ctx_finish(const union bpf_attr *kattr,
+			  union bpf_attr __user *uattr, const void *data,
+			  u32 size)
+{
+	void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
+	int err = -EFAULT;
+	u32 copy_size = size;
+
+	if (!data || !data_out)
+		return 0;
+
+	if (copy_size > kattr->test.ctx_size_out) {
+		copy_size = kattr->test.ctx_size_out;
+		err = -ENOSPC;
+	}
+
+	if (copy_to_user(data_out, data, copy_size))
+		goto out;
+	if (copy_to_user(&uattr->test.ctx_size_out, &size, sizeof(size)))
+		goto out;
+	if (err != -ENOSPC)
+		err = 0;
+out:
+	return err;
+}
+
+/**
+ * range_is_zero - test whether buffer is initialized
+ * @buf: buffer to check
+ * @from: check from this position
+ * @to: check up until (excluding) this position
+ *
+ * This function returns true if the there is a non-zero byte
+ * in the buf in the range [from,to).
+ */
+static inline bool range_is_zero(void *buf, size_t from, size_t to)
+{
+	return !memchr_inv((u8 *)buf + from, 0, to - from);
+}
+
+static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
+{
+	struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
+
+	if (!__skb)
+		return 0;
+
+	/* make sure the fields we don't use are zeroed */
+	if (!range_is_zero(__skb, 0, offsetof(struct __sk_buff, mark)))
+		return -EINVAL;
+
+	/* mark is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, mark),
+			   offsetof(struct __sk_buff, priority)))
+		return -EINVAL;
+
+	/* priority is allowed */
+	/* ingress_ifindex is allowed */
+	/* ifindex is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, ifindex),
+			   offsetof(struct __sk_buff, cb)))
+		return -EINVAL;
+
+	/* cb is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, cb),
+			   offsetof(struct __sk_buff, tstamp)))
+		return -EINVAL;
+
+	/* tstamp is allowed */
+	/* wire_len is allowed */
+	/* gso_segs is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs),
+			   offsetof(struct __sk_buff, gso_size)))
+		return -EINVAL;
+
+	/* gso_size is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_size),
+			   offsetof(struct __sk_buff, hwtstamp)))
+		return -EINVAL;
+
+	/* hwtstamp is allowed */
+
+	if (!range_is_zero(__skb, offsetofend(struct __sk_buff, hwtstamp),
+			   sizeof(struct __sk_buff)))
+		return -EINVAL;
+
+	skb->mark = __skb->mark;
+	skb->priority = __skb->priority;
+	skb->skb_iif = __skb->ingress_ifindex;
+	skb->tstamp = __skb->tstamp;
+	memcpy(&cb->data, __skb->cb, QDISC_CB_PRIV_LEN);
+
+	if (__skb->wire_len == 0) {
+		cb->pkt_len = skb->len;
+	} else {
+		if (__skb->wire_len < skb->len ||
+		    __skb->wire_len > GSO_LEGACY_MAX_SIZE)
+			return -EINVAL;
+		cb->pkt_len = __skb->wire_len;
+	}
+
+	if (__skb->gso_segs > GSO_MAX_SEGS)
+		return -EINVAL;
+	skb_shinfo(skb)->gso_segs = __skb->gso_segs;
+	skb_shinfo(skb)->gso_size = __skb->gso_size;
+	skb_shinfo(skb)->hwtstamps.hwtstamp = __skb->hwtstamp;
+
+	return 0;
+}
+
+static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
+{
+	struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
+
+	if (!__skb)
+		return;
+
+	__skb->mark = skb->mark;
+	__skb->priority = skb->priority;
+	__skb->ingress_ifindex = skb->skb_iif;
+	__skb->ifindex = skb->dev->ifindex;
+	__skb->tstamp = skb->tstamp;
+	memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
+	__skb->wire_len = cb->pkt_len;
+	__skb->gso_segs = skb_shinfo(skb)->gso_segs;
+	__skb->hwtstamp = skb_shinfo(skb)->hwtstamps.hwtstamp;
+}
+
+static struct proto bpf_dummy_proto = {
+	.name   = "bpf_dummy",
+	.owner  = THIS_MODULE,
+	.obj_size = sizeof(struct sock),
+};
+
+int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
+			  union bpf_attr __user *uattr)
+{
+	bool is_l2 = false, is_direct_pkt_access = false;
+	struct net *net = current->nsproxy->net_ns;
+	struct net_device *dev = net->loopback_dev;
+	u32 size = kattr->test.data_size_in;
+	u32 repeat = kattr->test.repeat;
+	struct __sk_buff *ctx = NULL;
+	u32 retval, duration;
+	int hh_len = ETH_HLEN;
+	struct sk_buff *skb;
+	struct sock *sk;
+	void *data;
+	int ret;
+
+	if (kattr->test.flags || kattr->test.cpu || kattr->test.batch_size)
+		return -EINVAL;
+
+	data = bpf_test_init(kattr, kattr->test.data_size_in,
+			     size, NET_SKB_PAD + NET_IP_ALIGN,
+			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
+	if (IS_ERR(ctx)) {
+		kfree(data);
+		return PTR_ERR(ctx);
+	}
+
+	switch (prog->type) {
+	case BPF_PROG_TYPE_SCHED_CLS:
+	case BPF_PROG_TYPE_SCHED_ACT:
+		is_l2 = true;
+		fallthrough;
+	case BPF_PROG_TYPE_LWT_IN:
+	case BPF_PROG_TYPE_LWT_OUT:
+	case BPF_PROG_TYPE_LWT_XMIT:
+		is_direct_pkt_access = true;
+		break;
+	default:
+		break;
+	}
+
+	sk = sk_alloc(net, AF_UNSPEC, GFP_USER, &bpf_dummy_proto, 1);
+	if (!sk) {
+		kfree(data);
+		kfree(ctx);
+		return -ENOMEM;
+	}
+	sock_init_data(NULL, sk);
+
+	skb = build_skb(data, 0);
+	if (!skb) {
+		kfree(data);
+		kfree(ctx);
+		sk_free(sk);
+		return -ENOMEM;
+	}
+	skb->sk = sk;
+
+	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+	__skb_put(skb, size);
+	if (ctx && ctx->ifindex > 1) {
+		dev = dev_get_by_index(net, ctx->ifindex);
+		if (!dev) {
+			ret = -ENODEV;
+			goto out;
+		}
+	}
+	skb->protocol = eth_type_trans(skb, dev);
+	skb_reset_network_header(skb);
+
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		sk->sk_family = AF_INET;
+		if (sizeof(struct iphdr) <= skb_headlen(skb)) {
+			sk->sk_rcv_saddr = ip_hdr(skb)->saddr;
+			sk->sk_daddr = ip_hdr(skb)->daddr;
+		}
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case htons(ETH_P_IPV6):
+		sk->sk_family = AF_INET6;
+		if (sizeof(struct ipv6hdr) <= skb_headlen(skb)) {
+			sk->sk_v6_rcv_saddr = ipv6_hdr(skb)->saddr;
+			sk->sk_v6_daddr = ipv6_hdr(skb)->daddr;
+		}
+		break;
+#endif
+	default:
+		break;
+	}
+
+	if (is_l2)
+		__skb_push(skb, hh_len);
+	if (is_direct_pkt_access)
+		bpf_compute_data_pointers(skb);
+	ret = convert___skb_to_skb(skb, ctx);
+	if (ret)
+		goto out;
+	ret = bpf_test_run(prog, skb, repeat, &retval, &duration, false);
+	if (ret)
+		goto out;
+	if (!is_l2) {
+		if (skb_headroom(skb) < hh_len) {
+			int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
+
+			if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
+				ret = -ENOMEM;
+				goto out;
+			}
+		}
+		memset(__skb_push(skb, hh_len), 0, hh_len);
+	}
+	convert_skb_to___skb(skb, ctx);
+
+	size = skb->len;
+	/* bpf program can never convert linear skb to non-linear */
+	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
+		size = skb_headlen(skb);
+	ret = bpf_test_finish(kattr, uattr, skb->data, NULL, size, retval,
+			      duration);
+	if (!ret)
+		ret = bpf_ctx_finish(kattr, uattr, ctx,
+				     sizeof(struct __sk_buff));
+out:
+	if (dev && dev != net->loopback_dev)
+		dev_put(dev);
+	kfree_skb(skb);
+	sk_free(sk);
+	kfree(ctx);
+	return ret;
+}
+
+static int xdp_convert_md_to_buff(struct xdp_md *xdp_md, struct xdp_buff *xdp)
+{
+	unsigned int ingress_ifindex, rx_queue_index;
+	struct netdev_rx_queue *rxqueue;
+	struct net_device *device;
+
+	if (!xdp_md)
+		return 0;
+
+	if (xdp_md->egress_ifindex != 0)
+		return -EINVAL;
+
+	ingress_ifindex = xdp_md->ingress_ifindex;
+	rx_queue_index = xdp_md->rx_queue_index;
+
+	if (!ingress_ifindex && rx_queue_index)
+		return -EINVAL;
+
+	if (ingress_ifindex) {
+		device = dev_get_by_index(current->nsproxy->net_ns,
+					  ingress_ifindex);
+		if (!device)
+			return -ENODEV;
+
+		if (rx_queue_index >= device->real_num_rx_queues)
+			goto free_dev;
+
+		rxqueue = __netif_get_rx_queue(device, rx_queue_index);
+
+		if (!xdp_rxq_info_is_reg(&rxqueue->xdp_rxq))
+			goto free_dev;
+
+		xdp->rxq = &rxqueue->xdp_rxq;
+		/* The device is now tracked in the xdp->rxq for later
+		 * dev_put()
+		 */
+	}
+
+	xdp->data = xdp->data_meta + xdp_md->data;
+	return 0;
+
+free_dev:
+	dev_put(device);
+	return -EINVAL;
+}
+
+static void xdp_convert_buff_to_md(struct xdp_buff *xdp, struct xdp_md *xdp_md)
+{
+	if (!xdp_md)
+		return;
+
+	xdp_md->data = xdp->data - xdp->data_meta;
+	xdp_md->data_end = xdp->data_end - xdp->data_meta;
+
+	if (xdp_md->ingress_ifindex)
+		dev_put(xdp->rxq->dev);
+}
+
+int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
+			  union bpf_attr __user *uattr)
+{
+	bool do_live = (kattr->test.flags & BPF_F_TEST_XDP_LIVE_FRAMES);
+	u32 tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	u32 batch_size = kattr->test.batch_size;
+	u32 retval = 0, duration, max_data_sz;
+	u32 size = kattr->test.data_size_in;
+	u32 headroom = XDP_PACKET_HEADROOM;
+	u32 repeat = kattr->test.repeat;
+	struct netdev_rx_queue *rxqueue;
+	struct skb_shared_info *sinfo;
+	struct xdp_buff xdp = {};
+	int i, ret = -EINVAL;
+	struct xdp_md *ctx;
+	void *data;
+
+	if (prog->expected_attach_type == BPF_XDP_DEVMAP ||
+	    prog->expected_attach_type == BPF_XDP_CPUMAP)
+		return -EINVAL;
+
+	if (kattr->test.flags & ~BPF_F_TEST_XDP_LIVE_FRAMES)
+		return -EINVAL;
+
+	if (do_live) {
+		if (!batch_size)
+			batch_size = NAPI_POLL_WEIGHT;
+		else if (batch_size > TEST_XDP_MAX_BATCH)
+			return -E2BIG;
+
+		headroom += sizeof(struct xdp_page_head);
+	} else if (batch_size) {
+		return -EINVAL;
+	}
+
+	ctx = bpf_ctx_init(kattr, sizeof(struct xdp_md));
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	if (ctx) {
+		/* There can't be user provided data before the meta data */
+		if (ctx->data_meta || ctx->data_end != size ||
+		    ctx->data > ctx->data_end ||
+		    unlikely(xdp_metalen_invalid(ctx->data)) ||
+		    (do_live && (kattr->test.data_out || kattr->test.ctx_out)))
+			goto free_ctx;
+		/* Meta data is allocated from the headroom */
+		headroom -= ctx->data;
+	}
+
+	max_data_sz = 4096 - headroom - tailroom;
+	if (size > max_data_sz) {
+		/* disallow live data mode for jumbo frames */
+		if (do_live)
+			goto free_ctx;
+		size = max_data_sz;
+	}
+
+	data = bpf_test_init(kattr, size, max_data_sz, headroom, tailroom);
+	if (IS_ERR(data)) {
+		ret = PTR_ERR(data);
+		goto free_ctx;
+	}
+
+	rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
+	rxqueue->xdp_rxq.frag_size = headroom + max_data_sz + tailroom;
+	xdp_init_buff(&xdp, rxqueue->xdp_rxq.frag_size, &rxqueue->xdp_rxq);
+	xdp_prepare_buff(&xdp, data, headroom, size, true);
+	sinfo = xdp_get_shared_info_from_buff(&xdp);
+
+	ret = xdp_convert_md_to_buff(ctx, &xdp);
+	if (ret)
+		goto free_data;
+
+	if (unlikely(kattr->test.data_size_in > size)) {
+		void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
+
+		while (size < kattr->test.data_size_in) {
+			struct page *page;
+			skb_frag_t *frag;
+			u32 data_len;
+
+			if (sinfo->nr_frags == MAX_SKB_FRAGS) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			page = alloc_page(GFP_KERNEL);
+			if (!page) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			frag = &sinfo->frags[sinfo->nr_frags++];
+			__skb_frag_set_page(frag, page);
+
+			data_len = min_t(u32, kattr->test.data_size_in - size,
+					 PAGE_SIZE);
+			skb_frag_size_set(frag, data_len);
+
+			if (copy_from_user(page_address(page), data_in + size,
+					   data_len)) {
+				ret = -EFAULT;
+				goto out;
+			}
+			sinfo->xdp_frags_size += data_len;
+			size += data_len;
+		}
+		xdp_buff_set_frags_flag(&xdp);
+	}
+
+	if (repeat > 1)
+		bpf_prog_change_xdp(NULL, prog);
+
+	if (do_live)
+		ret = bpf_test_run_xdp_live(prog, &xdp, repeat, batch_size, &duration);
+	else
+		ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration, true);
+	/* We convert the xdp_buff back to an xdp_md before checking the return
+	 * code so the reference count of any held netdevice will be decremented
+	 * even if the test run failed.
+	 */
+	xdp_convert_buff_to_md(&xdp, ctx);
+	if (ret)
+		goto out;
+
+	size = xdp.data_end - xdp.data_meta + sinfo->xdp_frags_size;
+	ret = bpf_test_finish(kattr, uattr, xdp.data_meta, sinfo, size,
+			      retval, duration);
+	if (!ret)
+		ret = bpf_ctx_finish(kattr, uattr, ctx,
+				     sizeof(struct xdp_md));
+
+out:
+	if (repeat > 1)
+		bpf_prog_change_xdp(prog, NULL);
+free_data:
+	for (i = 0; i < sinfo->nr_frags; i++)
+		__free_page(skb_frag_page(&sinfo->frags[i]));
+	kfree(data);
+free_ctx:
+	kfree(ctx);
+	return ret;
+}
+
+static int verify_user_bpf_flow_keys(struct bpf_flow_keys *ctx)
+{
+	/* make sure the fields we don't use are zeroed */
+	if (!range_is_zero(ctx, 0, offsetof(struct bpf_flow_keys, flags)))
+		return -EINVAL;
+
+	/* flags is allowed */
+
+	if (!range_is_zero(ctx, offsetofend(struct bpf_flow_keys, flags),
+			   sizeof(struct bpf_flow_keys)))
+		return -EINVAL;
+
+	return 0;
+}
+
+int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
+				     const union bpf_attr *kattr,
+				     union bpf_attr __user *uattr)
+{
+	struct bpf_test_timer t = { NO_PREEMPT };
+	u32 size = kattr->test.data_size_in;
+	struct bpf_flow_dissector ctx = {};
+	u32 repeat = kattr->test.repeat;
+	struct bpf_flow_keys *user_ctx;
+	struct bpf_flow_keys flow_keys;
+	const struct ethhdr *eth;
+	unsigned int flags = 0;
+	u32 retval, duration;
+	void *data;
+	int ret;
+
+	if (kattr->test.flags || kattr->test.cpu || kattr->test.batch_size)
+		return -EINVAL;
+
+	if (size < ETH_HLEN)
+		return -EINVAL;
+
+	data = bpf_test_init(kattr, kattr->test.data_size_in, size, 0, 0);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	eth = (struct ethhdr *)data;
+
+	if (!repeat)
+		repeat = 1;
+
+	user_ctx = bpf_ctx_init(kattr, sizeof(struct bpf_flow_keys));
+	if (IS_ERR(user_ctx)) {
+		kfree(data);
+		return PTR_ERR(user_ctx);
+	}
+	if (user_ctx) {
+		ret = verify_user_bpf_flow_keys(user_ctx);
+		if (ret)
+			goto out;
+		flags = user_ctx->flags;
+	}
+
+	ctx.flow_keys = &flow_keys;
+	ctx.data = data;
+	ctx.data_end = (__u8 *)data + size;
+
+	bpf_test_timer_enter(&t);
+	do {
+		retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
+					  size, flags);
+	} while (bpf_test_timer_continue(&t, 1, repeat, &ret, &duration));
+	bpf_test_timer_leave(&t);
+
+	if (ret < 0)
+		goto out;
+
+	ret = bpf_test_finish(kattr, uattr, &flow_keys, NULL,
+			      sizeof(flow_keys), retval, duration);
+	if (!ret)
+		ret = bpf_ctx_finish(kattr, uattr, user_ctx,
+				     sizeof(struct bpf_flow_keys));
+
+out:
+	kfree(user_ctx);
+	kfree(data);
+	return ret;
+}
+
+int bpf_prog_test_run_sk_lookup(struct bpf_prog *prog, const union bpf_attr *kattr,
+				union bpf_attr __user *uattr)
+{
+	struct bpf_test_timer t = { NO_PREEMPT };
+	struct bpf_prog_array *progs = NULL;
+	struct bpf_sk_lookup_kern ctx = {};
+	u32 repeat = kattr->test.repeat;
+	struct bpf_sk_lookup *user_ctx;
+	u32 retval, duration;
+	int ret = -EINVAL;
+
+	if (kattr->test.flags || kattr->test.cpu || kattr->test.batch_size)
+		return -EINVAL;
+
+	if (kattr->test.data_in || kattr->test.data_size_in || kattr->test.data_out ||
+	    kattr->test.data_size_out)
+		return -EINVAL;
+
+	if (!repeat)
+		repeat = 1;
+
+	user_ctx = bpf_ctx_init(kattr, sizeof(*user_ctx));
+	if (IS_ERR(user_ctx))
+		return PTR_ERR(user_ctx);
+
+	if (!user_ctx)
+		return -EINVAL;
+
+	if (user_ctx->sk)
+		goto out;
+
+	if (!range_is_zero(user_ctx, offsetofend(typeof(*user_ctx), local_port), sizeof(*user_ctx)))
+		goto out;
+
+	if (user_ctx->local_port > U16_MAX) {
+		ret = -ERANGE;
+		goto out;
+	}
+
+	ctx.family = (u16)user_ctx->family;
+	ctx.protocol = (u16)user_ctx->protocol;
+	ctx.dport = (u16)user_ctx->local_port;
+	ctx.sport = user_ctx->remote_port;
+
+	switch (ctx.family) {
+	case AF_INET:
+		ctx.v4.daddr = (__force __be32)user_ctx->local_ip4;
+		ctx.v4.saddr = (__force __be32)user_ctx->remote_ip4;
+		break;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		ctx.v6.daddr = (struct in6_addr *)user_ctx->local_ip6;
+		ctx.v6.saddr = (struct in6_addr *)user_ctx->remote_ip6;
+		break;
+#endif
+
+	default:
+		ret = -EAFNOSUPPORT;
+		goto out;
+	}
+
+	progs = bpf_prog_array_alloc(1, GFP_KERNEL);
+	if (!progs) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	progs->items[0].prog = prog;
+
+	bpf_test_timer_enter(&t);
+	do {
+		ctx.selected_sk = NULL;
+		retval = BPF_PROG_SK_LOOKUP_RUN_ARRAY(progs, ctx, bpf_prog_run);
+	} while (bpf_test_timer_continue(&t, 1, repeat, &ret, &duration));
+	bpf_test_timer_leave(&t);
+
+	if (ret < 0)
+		goto out;
+
+	user_ctx->cookie = 0;
+	if (ctx.selected_sk) {
+		if (ctx.selected_sk->sk_reuseport && !ctx.no_reuseport) {
+			ret = -EOPNOTSUPP;
+			goto out;
+		}
+
+		user_ctx->cookie = sock_gen_cookie(ctx.selected_sk);
+	}
+
+	ret = bpf_test_finish(kattr, uattr, NULL, NULL, 0, retval, duration);
+	if (!ret)
+		ret = bpf_ctx_finish(kattr, uattr, user_ctx, sizeof(*user_ctx));
+
+out:
+	bpf_prog_array_free(progs);
+	kfree(user_ctx);
+	return ret;
+}
+
+int bpf_prog_test_run_syscall(struct bpf_prog *prog,
+			      const union bpf_attr *kattr,
+			      union bpf_attr __user *uattr)
+{
+	void __user *ctx_in = u64_to_user_ptr(kattr->test.ctx_in);
+	__u32 ctx_size_in = kattr->test.ctx_size_in;
+	void *ctx = NULL;
+	u32 retval;
+	int err = 0;
+
+	/* doesn't support data_in/out, ctx_out, duration, or repeat or flags */
+	if (kattr->test.data_in || kattr->test.data_out ||
+	    kattr->test.ctx_out || kattr->test.duration ||
+	    kattr->test.repeat || kattr->test.flags ||
+	    kattr->test.batch_size)
+		return -EINVAL;
+
+	if (ctx_size_in < prog->aux->max_ctx_offset ||
+	    ctx_size_in > U16_MAX)
+		return -EINVAL;
+
+	if (ctx_size_in) {
+		ctx = memdup_user(ctx_in, ctx_size_in);
+		if (IS_ERR(ctx))
+			return PTR_ERR(ctx);
+	}
+
+	rcu_read_lock_trace();
+	retval = bpf_prog_run_pin_on_cpu(prog, ctx);
+	rcu_read_unlock_trace();
+
+	if (copy_to_user(&uattr->test.retval, &retval, sizeof(u32))) {
+		err = -EFAULT;
+		goto out;
+	}
+	if (ctx_size_in)
+		if (copy_to_user(ctx_in, ctx, ctx_size_in))
+			err = -EFAULT;
+out:
+	kfree(ctx);
+	return err;
+}
+
+static const struct btf_kfunc_id_set bpf_prog_test_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set   = &test_sk_check_kfunc_ids,
+};
+
+BTF_ID_LIST(bpf_prog_test_dtor_kfunc_ids)
+BTF_ID(struct, prog_test_ref_kfunc)
+BTF_ID(func, bpf_kfunc_call_test_release)
+BTF_ID(struct, prog_test_member)
+BTF_ID(func, bpf_kfunc_call_memb_release)
+
+static int __init bpf_prog_test_run_init(void)
+{
+	const struct btf_id_dtor_kfunc bpf_prog_test_dtor_kfunc[] = {
+		{
+		  .btf_id       = bpf_prog_test_dtor_kfunc_ids[0],
+		  .kfunc_btf_id = bpf_prog_test_dtor_kfunc_ids[1]
+		},
+		{
+		  .btf_id	= bpf_prog_test_dtor_kfunc_ids[2],
+		  .kfunc_btf_id = bpf_prog_test_dtor_kfunc_ids[3],
+		},
+	};
+	int ret;
+
+	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_prog_test_kfunc_set);
+	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_prog_test_kfunc_set);
+	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_prog_test_kfunc_set);
+	return ret ?: register_btf_id_dtor_kfuncs(bpf_prog_test_dtor_kfunc,
+						  ARRAY_SIZE(bpf_prog_test_dtor_kfunc),
+						  THIS_MODULE);
+}
+late_initcall(bpf_prog_test_run_init);
diff --git a/net/bpfilter/.gitignore b/net/bpfilter/.gitignore
new file mode 100644
index 000000000..f34e85ee8
--- /dev/null
+++ b/net/bpfilter/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+bpfilter_umh
diff --git a/net/bpfilter/Kconfig b/net/bpfilter/Kconfig
new file mode 100644
index 000000000..3d4a21462
--- /dev/null
+++ b/net/bpfilter/Kconfig
@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig BPFILTER
+	bool "BPF based packet filtering framework (BPFILTER)"
+	depends on BPF && INET
+	select USERMODE_DRIVER
+	help
+	  This builds experimental bpfilter framework that is aiming to
+	  provide netfilter compatible functionality via BPF
+
+if BPFILTER
+config BPFILTER_UMH
+	tristate "bpfilter kernel module with user mode helper"
+	depends on CC_CAN_LINK
+	depends on m || CC_CAN_LINK_STATIC
+	default m
+	help
+	  This builds bpfilter kernel module with embedded user mode helper
+
+	  Note: To compile this as built-in, your toolchain must support
+	  building static binaries, since rootfs isn't mounted at the time
+	  when __init functions are called and do_execv won't be able to find
+	  the elf interpreter.
+endif
diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile
new file mode 100644
index 000000000..cdac82b8c
--- /dev/null
+++ b/net/bpfilter/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux BPFILTER layer.
+#
+
+userprogs := bpfilter_umh
+bpfilter_umh-objs := main.o
+userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi
+
+ifeq ($(CONFIG_BPFILTER_UMH), y)
+# builtin bpfilter_umh should be linked with -static
+# since rootfs isn't mounted at the time of __init
+# function is called and do_execv won't find elf interpreter
+userldflags += -static
+endif
+
+$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+
+obj-$(CONFIG_BPFILTER_UMH) += bpfilter.o
+bpfilter-objs += bpfilter_kern.o bpfilter_umh_blob.o
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
new file mode 100644
index 000000000..422ec6e7c
--- /dev/null
+++ b/net/bpfilter/bpfilter_kern.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/umh.h>
+#include <linux/bpfilter.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include "msgfmt.h"
+
+extern char bpfilter_umh_start;
+extern char bpfilter_umh_end;
+
+static void shutdown_umh(void)
+{
+	struct umd_info *info = &bpfilter_ops.info;
+	struct pid *tgid = info->tgid;
+
+	if (tgid) {
+		kill_pid(tgid, SIGKILL, 1);
+		wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+		bpfilter_umh_cleanup(info);
+	}
+}
+
+static void __stop_umh(void)
+{
+	if (IS_ENABLED(CONFIG_INET))
+		shutdown_umh();
+}
+
+static int bpfilter_send_req(struct mbox_request *req)
+{
+	struct mbox_reply reply;
+	loff_t pos = 0;
+	ssize_t n;
+
+	if (!bpfilter_ops.info.tgid)
+		return -EFAULT;
+	pos = 0;
+	n = kernel_write(bpfilter_ops.info.pipe_to_umh, req, sizeof(*req),
+			   &pos);
+	if (n != sizeof(*req)) {
+		pr_err("write fail %zd\n", n);
+		goto stop;
+	}
+	pos = 0;
+	n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply),
+			&pos);
+	if (n != sizeof(reply)) {
+		pr_err("read fail %zd\n", n);
+		goto stop;
+	}
+	return reply.status;
+stop:
+	__stop_umh();
+	return -EFAULT;
+}
+
+static int bpfilter_process_sockopt(struct sock *sk, int optname,
+				    sockptr_t optval, unsigned int optlen,
+				    bool is_set)
+{
+	struct mbox_request req = {
+		.is_set		= is_set,
+		.pid		= current->pid,
+		.cmd		= optname,
+		.addr		= (uintptr_t)optval.user,
+		.len		= optlen,
+	};
+	if (sockptr_is_kernel(optval)) {
+		pr_err("kernel access not supported\n");
+		return -EFAULT;
+	}
+	return bpfilter_send_req(&req);
+}
+
+static int start_umh(void)
+{
+	struct mbox_request req = { .pid = current->pid };
+	int err;
+
+	/* fork usermode process */
+	err = fork_usermode_driver(&bpfilter_ops.info);
+	if (err)
+		return err;
+	pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid));
+
+	/* health check that usermode process started correctly */
+	if (bpfilter_send_req(&req) != 0) {
+		shutdown_umh();
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int __init load_umh(void)
+{
+	int err;
+
+	err = umd_load_blob(&bpfilter_ops.info,
+			    &bpfilter_umh_start,
+			    &bpfilter_umh_end - &bpfilter_umh_start);
+	if (err)
+		return err;
+
+	mutex_lock(&bpfilter_ops.lock);
+	err = start_umh();
+	if (!err && IS_ENABLED(CONFIG_INET)) {
+		bpfilter_ops.sockopt = &bpfilter_process_sockopt;
+		bpfilter_ops.start = &start_umh;
+	}
+	mutex_unlock(&bpfilter_ops.lock);
+	if (err)
+		umd_unload_blob(&bpfilter_ops.info);
+	return err;
+}
+
+static void __exit fini_umh(void)
+{
+	mutex_lock(&bpfilter_ops.lock);
+	if (IS_ENABLED(CONFIG_INET)) {
+		shutdown_umh();
+		bpfilter_ops.start = NULL;
+		bpfilter_ops.sockopt = NULL;
+	}
+	mutex_unlock(&bpfilter_ops.lock);
+
+	umd_unload_blob(&bpfilter_ops.info);
+}
+module_init(load_umh);
+module_exit(fini_umh);
+MODULE_LICENSE("GPL");
diff --git a/net/bpfilter/bpfilter_umh_blob.S b/net/bpfilter/bpfilter_umh_blob.S
new file mode 100644
index 000000000..40311d10d
--- /dev/null
+++ b/net/bpfilter/bpfilter_umh_blob.S
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+	.section .init.rodata, "a"
+	.global bpfilter_umh_start
+bpfilter_umh_start:
+	.incbin "net/bpfilter/bpfilter_umh"
+	.global bpfilter_umh_end
+bpfilter_umh_end:
diff --git a/net/bpfilter/main.c b/net/bpfilter/main.c
new file mode 100644
index 000000000..291a92546
--- /dev/null
+++ b/net/bpfilter/main.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/uio.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "../../include/uapi/linux/bpf.h"
+#include <asm/unistd.h>
+#include "msgfmt.h"
+
+FILE *debug_f;
+
+static int handle_get_cmd(struct mbox_request *cmd)
+{
+	switch (cmd->cmd) {
+	case 0:
+		return 0;
+	default:
+		break;
+	}
+	return -ENOPROTOOPT;
+}
+
+static int handle_set_cmd(struct mbox_request *cmd)
+{
+	return -ENOPROTOOPT;
+}
+
+static void loop(void)
+{
+	while (1) {
+		struct mbox_request req;
+		struct mbox_reply reply;
+		int n;
+
+		n = read(0, &req, sizeof(req));
+		if (n != sizeof(req)) {
+			fprintf(debug_f, "invalid request %d\n", n);
+			return;
+		}
+
+		reply.status = req.is_set ?
+			handle_set_cmd(&req) :
+			handle_get_cmd(&req);
+
+		n = write(1, &reply, sizeof(reply));
+		if (n != sizeof(reply)) {
+			fprintf(debug_f, "reply failed %d\n", n);
+			return;
+		}
+	}
+}
+
+int main(void)
+{
+	debug_f = fopen("/dev/kmsg", "w");
+	setvbuf(debug_f, 0, _IOLBF, 0);
+	fprintf(debug_f, "<5>Started bpfilter\n");
+	loop();
+	fclose(debug_f);
+	return 0;
+}
diff --git a/net/bpfilter/msgfmt.h b/net/bpfilter/msgfmt.h
new file mode 100644
index 000000000..98d121c62
--- /dev/null
+++ b/net/bpfilter/msgfmt.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NET_BPFILTER_MSGFMT_H
+#define _NET_BPFILTER_MSGFMT_H
+
+struct mbox_request {
+	__u64 addr;
+	__u32 len;
+	__u32 is_set;
+	__u32 cmd;
+	__u32 pid;
+};
+
+struct mbox_reply {
+	__u32 status;
+};
+
+#endif