Resguardo inicial

linux-7.2.3/tools/testing/selftests/hid/progs/hid.c

@@ -0,0 +1,615 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Red hat */
+#include "hid_bpf_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct attach_prog_args {
+	int prog_fd;
+	unsigned int hid;
+	int retval;
+	int insert_head;
+};
+
+__u64 callback_check = 52;
+__u64 callback2_check = 52;
+__u64 get_data_overflow_check;
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
+
+	if (!rw_data)
+		return 0; /* EPERM check */
+
+	callback_check = rw_data[1];
+
+	rw_data[2] = rw_data[1] + 5;
+
+	return hid_ctx->size;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops first_event = {
+	.hid_device_event = (void *)hid_first_event,
+	.hid_id = 2,
+};
+
+int __hid_subprog_first_event(struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
+
+	if (!rw_data)
+		return 0; /* EPERM check */
+
+	rw_data[2] = rw_data[1] + 5;
+
+	return hid_ctx->size;
+}
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_subprog_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	return __hid_subprog_first_event(hid_ctx, type);
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops subprog_first_event = {
+	.hid_device_event = (void *)hid_subprog_first_event,
+	.hid_id = 2,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+	if (!rw_data)
+		return 0; /* EPERM check */
+
+	rw_data[3] = rw_data[2] + 5;
+
+	return hid_ctx->size;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops second_event = {
+	.hid_device_event = (void *)hid_second_event,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
+
+	if (!rw_data)
+		return 0; /* EPERM check */
+
+	rw_data[0] = 2;
+
+	return 9;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops change_report_id = {
+	.hid_device_event = (void *)hid_change_report_id,
+};
+
+struct hid_hw_request_syscall_args {
+	/* data needs to come at offset 0 so we can use it in calls */
+	__u8 data[10];
+	unsigned int hid;
+	int retval;
+	size_t size;
+	enum hid_report_type type;
+	__u8 request_type;
+};
+
+SEC("syscall")
+int hid_user_raw_request(struct hid_hw_request_syscall_args *args)
+{
+	struct hid_bpf_ctx *ctx;
+	const size_t size = args->size;
+	int i, ret = 0;
+
+	if (size > sizeof(args->data))
+		return -7; /* -E2BIG */
+
+	ctx = hid_bpf_allocate_context(args->hid);
+	if (!ctx)
+		return -1; /* EPERM check */
+
+	ret = hid_bpf_hw_request(ctx,
+				 args->data,
+				 size,
+				 args->type,
+				 args->request_type);
+	args->retval = ret;
+
+	hid_bpf_release_context(ctx);
+
+	return 0;
+}
+
+SEC("syscall")
+int hid_user_output_report(struct hid_hw_request_syscall_args *args)
+{
+	struct hid_bpf_ctx *ctx;
+	const size_t size = args->size;
+	int i, ret = 0;
+
+	if (size > sizeof(args->data))
+		return -7; /* -E2BIG */
+
+	ctx = hid_bpf_allocate_context(args->hid);
+	if (!ctx)
+		return -1; /* EPERM check */
+
+	ret = hid_bpf_hw_output_report(ctx,
+				       args->data,
+				       size);
+	args->retval = ret;
+
+	hid_bpf_release_context(ctx);
+
+	return 0;
+}
+
+SEC("syscall")
+int hid_user_input_report(struct hid_hw_request_syscall_args *args)
+{
+	struct hid_bpf_ctx *ctx;
+	const size_t size = args->size;
+	int i, ret = 0;
+
+	if (size > sizeof(args->data))
+		return -7; /* -E2BIG */
+
+	ctx = hid_bpf_allocate_context(args->hid);
+	if (!ctx)
+		return -1; /* EPERM check */
+
+	ret = hid_bpf_input_report(ctx, HID_INPUT_REPORT, args->data, size);
+	args->retval = ret;
+
+	hid_bpf_release_context(ctx);
+
+	return 0;
+}
+
+static const __u8 rdesc[] = {
+	0x05, 0x01,				/* USAGE_PAGE (Generic Desktop) */
+	0x09, 0x32,				/* USAGE (Z) */
+	0x95, 0x01,				/* REPORT_COUNT (1) */
+	0x81, 0x06,				/* INPUT (Data,Var,Rel) */
+
+	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */
+	0x19, 0x01,				/* USAGE_MINIMUM (1) */
+	0x29, 0x03,				/* USAGE_MAXIMUM (3) */
+	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */
+	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */
+	0x95, 0x03,				/* REPORT_COUNT (3) */
+	0x75, 0x01,				/* REPORT_SIZE (1) */
+	0x91, 0x02,				/* Output (Data,Var,Abs) */
+	0x95, 0x01,				/* REPORT_COUNT (1) */
+	0x75, 0x05,				/* REPORT_SIZE (5) */
+	0x91, 0x01,				/* Output (Cnst,Var,Abs) */
+
+	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */
+	0x19, 0x06,				/* USAGE_MINIMUM (6) */
+	0x29, 0x08,				/* USAGE_MAXIMUM (8) */
+	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */
+	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */
+	0x95, 0x03,				/* REPORT_COUNT (3) */
+	0x75, 0x01,				/* REPORT_SIZE (1) */
+	0xb1, 0x02,				/* Feature (Data,Var,Abs) */
+	0x95, 0x01,				/* REPORT_COUNT (1) */
+	0x75, 0x05,				/* REPORT_SIZE (5) */
+	0x91, 0x01,				/* Output (Cnst,Var,Abs) */
+
+	0xc0,				/* END_COLLECTION */
+	0xc0,			/* END_COLLECTION */
+};
+
+/*
+ * the following program is marked as sleepable (struct_ops.s).
+ * This is not strictly mandatory but is a nice test for
+ * sleepable struct_ops
+ */
+SEC("?struct_ops.s/hid_rdesc_fixup")
+int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4096 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	callback2_check = data[4];
+
+	/* insert rdesc at offset 73 */
+	__builtin_memcpy(&data[73], rdesc, sizeof(rdesc));
+
+	/* Change Usage Vendor globally */
+	data[4] = 0x42;
+
+	return sizeof(rdesc) + 73;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops rdesc_fixup = {
+	.hid_rdesc_fixup = (void *)hid_rdesc_fixup,
+};
+
+SEC("?struct_ops.s/hid_rdesc_fixup")
+int BPF_PROG(hid_rdesc_fixup_get_data_overflow, struct hid_bpf_ctx *hid_ctx)
+{
+	if (!hid_bpf_get_data(hid_ctx, 2 /* offset */, ~0ULL /* size */))
+		get_data_overflow_check = 1;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops rdesc_fixup_get_data_overflow = {
+	.hid_rdesc_fixup = (void *)hid_rdesc_fixup_get_data_overflow,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* we need to be run first */
+	if (data[2] || data[3])
+		return -1;
+
+	data[1] = 1;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_insert1 = {
+	.hid_device_event = (void *)hid_test_insert1,
+	.flags = BPF_F_BEFORE,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* after insert0 and before insert2 */
+	if (!data[1] || data[3])
+		return -1;
+
+	data[2] = 2;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_insert2 = {
+	.hid_device_event = (void *)hid_test_insert2,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* at the end */
+	if (!data[1] || !data[2])
+		return -1;
+
+	data[3] = 3;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_insert3 = {
+	.hid_device_event = (void *)hid_test_insert3,
+};
+
+SEC("?struct_ops/hid_hw_request")
+int BPF_PROG(hid_test_filter_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum,
+	     enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source)
+{
+	return -20;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_filter_raw_request = {
+	.hid_hw_request = (void *)hid_test_filter_raw_request,
+};
+
+static struct file *current_file;
+
+SEC("fentry/hidraw_open")
+int BPF_PROG(hidraw_open, struct inode *inode, struct file *file)
+{
+	current_file = file;
+	return 0;
+}
+
+SEC("?struct_ops.s/hid_hw_request")
+int BPF_PROG(hid_test_hidraw_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum,
+	     enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */);
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* check if the incoming request comes from our hidraw operation */
+	if (source == (__u64)current_file) {
+		data[0] = reportnum;
+
+		ret = hid_bpf_hw_request(hctx, data, 2, rtype, reqtype);
+		if (ret != 2)
+			return -1;
+		data[0] = reportnum + 1;
+		data[1] = reportnum + 2;
+		data[2] = reportnum + 3;
+		return 3;
+	}
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_hidraw_raw_request = {
+	.hid_hw_request = (void *)hid_test_hidraw_raw_request,
+};
+
+SEC("?struct_ops.s/hid_hw_request")
+int BPF_PROG(hid_test_infinite_loop_raw_request, struct hid_bpf_ctx *hctx, unsigned char reportnum,
+	     enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */);
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* always forward the request as-is to the device, hid-bpf should prevent
+	 * infinite loops.
+	 */
+	data[0] = reportnum;
+
+	ret = hid_bpf_hw_request(hctx, data, 2, rtype, reqtype);
+	if (ret == 2)
+		return 3;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_infinite_loop_raw_request = {
+	.hid_hw_request = (void *)hid_test_infinite_loop_raw_request,
+};
+
+SEC("?struct_ops/hid_hw_output_report")
+int BPF_PROG(hid_test_filter_output_report, struct hid_bpf_ctx *hctx, unsigned char reportnum,
+	     enum hid_report_type rtype, enum hid_class_request reqtype, __u64 source)
+{
+	return -25;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_filter_output_report = {
+	.hid_hw_output_report = (void *)hid_test_filter_output_report,
+};
+
+SEC("?struct_ops.s/hid_hw_output_report")
+int BPF_PROG(hid_test_hidraw_output_report, struct hid_bpf_ctx *hctx, __u64 source)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */);
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* check if the incoming request comes from our hidraw operation */
+	if (source == (__u64)current_file)
+		return hid_bpf_hw_output_report(hctx, data, 2);
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_hidraw_output_report = {
+	.hid_hw_output_report = (void *)hid_test_hidraw_output_report,
+};
+
+SEC("?struct_ops.s/hid_hw_output_report")
+int BPF_PROG(hid_test_infinite_loop_output_report, struct hid_bpf_ctx *hctx, __u64 source)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 3 /* size */);
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* always forward the request as-is to the device, hid-bpf should prevent
+	 * infinite loops.
+	 */
+
+	ret = hid_bpf_hw_output_report(hctx, data, 2);
+	if (ret == 2)
+		return 2;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_infinite_loop_output_report = {
+	.hid_hw_output_report = (void *)hid_test_infinite_loop_output_report,
+};
+
+struct elem {
+	struct bpf_wq work;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, struct elem);
+} hmap SEC(".maps");
+
+static int wq_cb_sleepable(void *map, int *key, void *work)
+{
+	__u8 buf[9] = {2, 3, 4, 5, 6, 7, 8, 9, 10};
+	struct hid_bpf_ctx *hid_ctx;
+
+	hid_ctx = hid_bpf_allocate_context(*key);
+	if (!hid_ctx)
+		return 0; /* EPERM check */
+
+	hid_bpf_input_report(hid_ctx, HID_INPUT_REPORT, buf, sizeof(buf));
+
+	hid_bpf_release_context(hid_ctx);
+
+	return 0;
+}
+
+static int test_inject_input_report_callback(int *key)
+{
+	struct elem init = {}, *val;
+	struct bpf_wq *wq;
+
+	if (bpf_map_update_elem(&hmap, key, &init, 0))
+		return -1;
+
+	val = bpf_map_lookup_elem(&hmap, key);
+	if (!val)
+		return -2;
+
+	wq = &val->work;
+	if (bpf_wq_init(wq, &hmap, 0) != 0)
+		return -3;
+
+	if (bpf_wq_set_callback(wq, wq_cb_sleepable, 0))
+		return -4;
+
+	if (bpf_wq_start(wq, 0))
+		return -5;
+
+	return 0;
+}
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_multiply_events_wq, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 9 /* size */);
+	int hid = hid_ctx->hid->id;
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	if (data[0] != 1)
+		return 0;
+
+	ret = test_inject_input_report_callback(&hid);
+	if (ret)
+		return ret;
+
+	data[1] += 5;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_multiply_events_wq = {
+	.hid_device_event = (void *)hid_test_multiply_events_wq,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_multiply_events, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 9 /* size */);
+	__u8 buf[9];
+	int ret;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	if (data[0] != 1)
+		return 0;
+
+	/*
+	 * we have to use an intermediate buffer as hid_bpf_input_report
+	 * will memset data to \0
+	 */
+	__builtin_memcpy(buf, data, sizeof(buf));
+
+	buf[0] = 2;
+	buf[1] += 5;
+	ret = hid_bpf_try_input_report(hid_ctx, HID_INPUT_REPORT, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * In real world we should reset the original buffer as data might be garbage now,
+	 * but it actually now has the content of 'buf'
+	 */
+	data[1] += 5;
+
+	return 9;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_multiply_events = {
+	.hid_device_event = (void *)hid_test_multiply_events,
+};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_infinite_loop_input_report, struct hid_bpf_ctx *hctx,
+	     enum hid_report_type report_type, __u64 source)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 6 /* size */);
+	__u8 buf[6];
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/*
+	 * we have to use an intermediate buffer as hid_bpf_input_report
+	 * will memset data to \0
+	 */
+	__builtin_memcpy(buf, data, sizeof(buf));
+
+	/* always forward the request as-is to the device, hid-bpf should prevent
+	 * infinite loops.
+	 * the return value is ignored so the event is passing to userspace.
+	 */
+
+	hid_bpf_try_input_report(hctx, report_type, buf, sizeof(buf));
+
+	/* each time we process the event, we increment by one data[1]:
+	 * after each successful call to hid_bpf_try_input_report, buf
+	 * has been memcopied into data by the kernel.
+	 */
+	data[1] += 1;
+
+	return 0;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_infinite_loop_input_report = {
+	.hid_device_event = (void *)hid_test_infinite_loop_input_report,
+};

linux-7.2.3/tools/testing/selftests/hid/progs/hid_bpf_helpers.h

@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2022 Benjamin Tissoires
+ */
+
+#ifndef __HID_BPF_HELPERS_H
+#define __HID_BPF_HELPERS_H
+
+/* "undefine" structs and enums in vmlinux.h, because we "override" them below */
+#define bpf_wq bpf_wq___not_used
+#define hid_bpf_ctx hid_bpf_ctx___not_used
+#define hid_bpf_ops hid_bpf_ops___not_used
+#define hid_device hid_device___not_used
+#define hid_report_type hid_report_type___not_used
+#define hid_class_request hid_class_request___not_used
+#define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
+#define HID_INPUT_REPORT         HID_INPUT_REPORT___not_used
+#define HID_OUTPUT_REPORT        HID_OUTPUT_REPORT___not_used
+#define HID_FEATURE_REPORT       HID_FEATURE_REPORT___not_used
+#define HID_REPORT_TYPES         HID_REPORT_TYPES___not_used
+#define HID_REQ_GET_REPORT       HID_REQ_GET_REPORT___not_used
+#define HID_REQ_GET_IDLE         HID_REQ_GET_IDLE___not_used
+#define HID_REQ_GET_PROTOCOL     HID_REQ_GET_PROTOCOL___not_used
+#define HID_REQ_SET_REPORT       HID_REQ_SET_REPORT___not_used
+#define HID_REQ_SET_IDLE         HID_REQ_SET_IDLE___not_used
+#define HID_REQ_SET_PROTOCOL     HID_REQ_SET_PROTOCOL___not_used
+
+/* do not define kfunc through vmlinux.h as this messes up our custom hack */
+#define BPF_NO_KFUNC_PROTOTYPES
+
+#include "vmlinux.h"
+
+#undef bpf_wq
+#undef hid_bpf_ctx
+#undef hid_bpf_ops
+#undef hid_device
+#undef hid_report_type
+#undef hid_class_request
+#undef hid_bpf_attach_flags
+#undef HID_INPUT_REPORT
+#undef HID_OUTPUT_REPORT
+#undef HID_FEATURE_REPORT
+#undef HID_REPORT_TYPES
+#undef HID_REQ_GET_REPORT
+#undef HID_REQ_GET_IDLE
+#undef HID_REQ_GET_PROTOCOL
+#undef HID_REQ_SET_REPORT
+#undef HID_REQ_SET_IDLE
+#undef HID_REQ_SET_PROTOCOL
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <linux/const.h>
+
+enum hid_report_type {
+	HID_INPUT_REPORT		= 0,
+	HID_OUTPUT_REPORT		= 1,
+	HID_FEATURE_REPORT		= 2,
+
+	HID_REPORT_TYPES,
+};
+
+struct hid_device {
+	unsigned int id;
+} __attribute__((preserve_access_index));
+
+struct bpf_wq {
+	__u64 __opaque[2];
+};
+
+struct hid_bpf_ctx {
+	struct hid_device *hid;
+	__u32 allocated_size;
+	union {
+		__s32 retval;
+		__s32 size;
+	};
+} __attribute__((preserve_access_index));
+
+enum hid_class_request {
+	HID_REQ_GET_REPORT		= 0x01,
+	HID_REQ_GET_IDLE		= 0x02,
+	HID_REQ_GET_PROTOCOL		= 0x03,
+	HID_REQ_SET_REPORT		= 0x09,
+	HID_REQ_SET_IDLE		= 0x0A,
+	HID_REQ_SET_PROTOCOL		= 0x0B,
+};
+
+struct hid_bpf_ops {
+	int			hid_id;
+	u32			flags;
+	struct list_head	list;
+	int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type,
+				u64 source);
+	int (*hid_rdesc_fixup)(struct hid_bpf_ctx *ctx);
+	int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum,
+			       enum hid_report_type rtype, enum hid_class_request reqtype,
+			       u64 source);
+	int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source);
+	struct hid_device *hdev;
+};
+
+#ifndef BPF_F_BEFORE
+#define BPF_F_BEFORE (1U << 3)
+#endif
+
+/* following are kfuncs exported by HID for HID-BPF */
+extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
+			      unsigned int offset,
+			      const size_t __sz) __weak __ksym;
+extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __weak __ksym;
+extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __weak __ksym;
+extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
+			      __u8 *data,
+			      size_t buf__sz,
+			      enum hid_report_type type,
+			      enum hid_class_request reqtype) __weak __ksym;
+extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
+				    __u8 *buf, size_t buf__sz) __weak __ksym;
+extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
+				enum hid_report_type type,
+				__u8 *data,
+				size_t buf__sz) __weak __ksym;
+extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,
+				    enum hid_report_type type,
+				    __u8 *data,
+				    size_t buf__sz) __weak __ksym;
+
+/* bpf_wq implementation */
+extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;
+extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym;
+extern int bpf_wq_set_callback(struct bpf_wq *wq,
+		int (*callback_fn)(void *, int *, void *),
+		unsigned int flags) __weak __ksym;
+
+#endif /* __HID_BPF_HELPERS_H */