drivers/hid/bpf/progs/hid_bpf_helpers.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2022 Benjamin Tissoires
  */

 #ifndef __HID_BPF_HELPERS_H
 #define __HID_BPF_HELPERS_H

 #include "vmlinux.h"
 #include <bpf/bpf_helpers.h>
 #include <linux/errno.h>

 extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
 			      unsigned int offset,
 			      const size_t __sz) __ksym;
 extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __ksym;
 extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __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) __ksym;

 #define HID_MAX_DESCRIPTOR_SIZE	4096
 #define HID_IGNORE_EVENT	-1

 /* extracted from <linux/input.h> */
 #define BUS_ANY			0x00
 #define BUS_PCI			0x01
 #define BUS_ISAPNP		0x02
 #define BUS_USB			0x03
 #define BUS_HIL			0x04
 #define BUS_BLUETOOTH		0x05
 #define BUS_VIRTUAL		0x06
 #define BUS_ISA			0x10
 #define BUS_I8042		0x11
 #define BUS_XTKBD		0x12
 #define BUS_RS232		0x13
 #define BUS_GAMEPORT		0x14
 #define BUS_PARPORT		0x15
 #define BUS_AMIGA		0x16
 #define BUS_ADB			0x17
 #define BUS_I2C			0x18
 #define BUS_HOST		0x19
 #define BUS_GSC			0x1A
 #define BUS_ATARI		0x1B
 #define BUS_SPI			0x1C
 #define BUS_RMI			0x1D
 #define BUS_CEC			0x1E
 #define BUS_INTEL_ISHTP		0x1F
 #define BUS_AMD_SFH		0x20

 /* extracted from <linux/hid.h> */
 #define HID_GROUP_ANY				0x0000
 #define HID_GROUP_GENERIC			0x0001
 #define HID_GROUP_MULTITOUCH			0x0002
 #define HID_GROUP_SENSOR_HUB			0x0003
 #define HID_GROUP_MULTITOUCH_WIN_8		0x0004
 #define HID_GROUP_RMI				0x0100
 #define HID_GROUP_WACOM				0x0101
 #define HID_GROUP_LOGITECH_DJ_DEVICE		0x0102
 #define HID_GROUP_STEAM				0x0103
 #define HID_GROUP_LOGITECH_27MHZ_DEVICE		0x0104
 #define HID_GROUP_VIVALDI			0x0105

 /* include/linux/mod_devicetable.h defines as (~0), but that gives us negative size arrays */
 #define HID_VID_ANY				0x0000
 #define HID_PID_ANY				0x0000

 #define BIT(n) (1UL << (n))
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

 /* Helper macro to convert (foo, __LINE__)  into foo134 so we can use __LINE__ for
  * field/variable names
  */
 #define COMBINE1(X, Y) X ## Y
 #define COMBINE(X, Y) COMBINE1(X, Y)

 /* Macro magic:
  * __uint(foo, 123) creates a int (*foo)[1234]
  *
  * We use that macro to declare an anonymous struct with several
  * fields, each is the declaration of an pointer to an array of size
  * bus/group/vid/pid. (Because it's a pointer to such an array, actual storage
  * would be sizeof(pointer) rather than sizeof(array). Not that we ever
  * instantiate it anyway).
  *
  * This is only used for BTF introspection, we can later check "what size
  * is the bus array" in the introspection data and thus extract the bus ID
  * again.
  *
  * And we use the __LINE__ to give each of our structs a unique name so the
  * BPF program writer doesn't have to.
  *
  * $ bpftool btf dump file target/bpf/HP_Elite_Presenter.bpf.o
  * shows the inspection data, start by searching for .hid_bpf_config
  * and working backwards from that (each entry references the type_id of the
  * content).
  */

 #define HID_DEVICE(b, g, ven, prod)	\
 	struct {			\
 		__uint(name, 0);	\
 		__uint(bus, (b));	\
 		__uint(group, (g));	\
 		__uint(vid, (ven));	\
 		__uint(pid, (prod));	\
 	} COMBINE(_entry, __LINE__)

 /* Macro magic below is to make HID_BPF_CONFIG() look like a function call that
  * we can pass multiple HID_DEVICE() invocations in.
  *
  * For up to 16 arguments, HID_BPF_CONFIG(one, two) resolves to
  *
  * union {
  *    HID_DEVICE(...);
  *    HID_DEVICE(...);
  * } _device_ids SEC(".hid_bpf_config")
  *
  */

 /* Returns the number of macro arguments, this expands
  * NARGS(a, b, c) to NTH_ARG(a, b, c, 15, 14, 13, .... 4, 3, 2, 1).
  * NTH_ARG always returns the 16th argument which in our case is 3.
  *
  * If we want more than 16 values _COUNTDOWN and _NTH_ARG both need to be
  * updated.
  */
 #define _NARGS(...)  _NARGS1(__VA_ARGS__, _COUNTDOWN)
 #define _NARGS1(...) _NTH_ARG(__VA_ARGS__)

 /* Add to this if we need more than 16 args */
 #define _COUNTDOWN \
 	15, 14, 13, 12, 11, 10, 9, 8,  \
 	 7,  6,  5,  4,  3,  2, 1, 0

 /* Return the 16 argument passed in. See _NARGS above for usage. Note this is
  * 1-indexed.
  */
 #define _NTH_ARG( \
 	_1,  _2,  _3,  _4,  _5,  _6,  _7, _8, \
 	_9, _10, _11, _12, _13, _14, _15,\
 	 N, ...) N

 /* Turns EXPAND(_ARG, a, b, c) into _ARG3(a, b, c) */
 #define _EXPAND(func, ...) COMBINE(func, _NARGS(__VA_ARGS__)) (__VA_ARGS__)

 /* And now define all the ARG macros for each number of args we want to accept */
 #define _ARG1(_1)                                                         _1;
 #define _ARG2(_1, _2)                                                     _1; _2;
 #define _ARG3(_1, _2, _3)                                                 _1; _2; _3;
 #define _ARG4(_1, _2, _3, _4)                                             _1; _2; _3; _4;
 #define _ARG5(_1, _2, _3, _4, _5)                                         _1; _2; _3; _4; _5;
 #define _ARG6(_1, _2, _3, _4, _5, _6)                                     _1; _2; _3; _4; _5; _6;
 #define _ARG7(_1, _2, _3, _4, _5, _6, _7)                                 _1; _2; _3; _4; _5; _6; _7;
 #define _ARG8(_1, _2, _3, _4, _5, _6, _7, _8)                             _1; _2; _3; _4; _5; _6; _7; _8;
 #define _ARG9(_1, _2, _3, _4, _5, _6, _7, _8, _9)                         _1; _2; _3; _4; _5; _6; _7; _8; _9;
 #define _ARG10(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a)                     _1; _2; _3; _4; _5; _6; _7; _8; _9; _a;
 #define _ARG11(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b)                 _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b;
 #define _ARG12(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c)             _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c;
 #define _ARG13(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d)         _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d;
 #define _ARG14(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e)     _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e;
 #define _ARG15(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e, _f) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e; _f;


 #define HID_BPF_CONFIG(...)  union { \
 	_EXPAND(_ARG, __VA_ARGS__) \
 } _device_ids SEC(".hid_bpf_config")

 #endif /* __HID_BPF_HELPERS_H */
	/* SPDX-License-Identifier: GPL-2.0-only */
	/* Copyright (c) 2022 Benjamin Tissoires
	*/

	#ifndef __HID_BPF_HELPERS_H
	#define __HID_BPF_HELPERS_H

	#include "vmlinux.h"
	#include <bpf/bpf_helpers.h>
	#include <linux/errno.h>

	extern __u8 hid_bpf_get_data(struct hid_bpf_ctx ctx,
	unsigned int offset,
	const size_t __sz) __ksym;
	extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __ksym;
	extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __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) __ksym;

	#define HID_MAX_DESCRIPTOR_SIZE 4096
	#define HID_IGNORE_EVENT -1

	/* extracted from <linux/input.h> */
	#define BUS_ANY 0x00
	#define BUS_PCI 0x01
	#define BUS_ISAPNP 0x02
	#define BUS_USB 0x03
	#define BUS_HIL 0x04
	#define BUS_BLUETOOTH 0x05
	#define BUS_VIRTUAL 0x06
	#define BUS_ISA 0x10
	#define BUS_I8042 0x11
	#define BUS_XTKBD 0x12
	#define BUS_RS232 0x13
	#define BUS_GAMEPORT 0x14
	#define BUS_PARPORT 0x15
	#define BUS_AMIGA 0x16
	#define BUS_ADB 0x17
	#define BUS_I2C 0x18
	#define BUS_HOST 0x19
	#define BUS_GSC 0x1A
	#define BUS_ATARI 0x1B
	#define BUS_SPI 0x1C
	#define BUS_RMI 0x1D
	#define BUS_CEC 0x1E
	#define BUS_INTEL_ISHTP 0x1F
	#define BUS_AMD_SFH 0x20

	/* extracted from <linux/hid.h> */
	#define HID_GROUP_ANY 0x0000
	#define HID_GROUP_GENERIC 0x0001
	#define HID_GROUP_MULTITOUCH 0x0002
	#define HID_GROUP_SENSOR_HUB 0x0003
	#define HID_GROUP_MULTITOUCH_WIN_8 0x0004
	#define HID_GROUP_RMI 0x0100
	#define HID_GROUP_WACOM 0x0101
	#define HID_GROUP_LOGITECH_DJ_DEVICE 0x0102
	#define HID_GROUP_STEAM 0x0103
	#define HID_GROUP_LOGITECH_27MHZ_DEVICE 0x0104
	#define HID_GROUP_VIVALDI 0x0105

	/* include/linux/mod_devicetable.h defines as (~0), but that gives us negative size arrays */
	#define HID_VID_ANY 0x0000
	#define HID_PID_ANY 0x0000

	#define BIT(n) (1UL << (n))
	#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

	/* Helper macro to convert (foo, __LINE__) into foo134 so we can use __LINE__ for
	* field/variable names
	*/
	#define COMBINE1(X, Y) X ## Y
	#define COMBINE(X, Y) COMBINE1(X, Y)

	/* Macro magic:
	* __uint(foo, 123) creates a int (*foo)[1234]
	*
	* We use that macro to declare an anonymous struct with several
	* fields, each is the declaration of an pointer to an array of size
	* bus/group/vid/pid. (Because it's a pointer to such an array, actual storage
	* would be sizeof(pointer) rather than sizeof(array). Not that we ever
	* instantiate it anyway).
	*
	* This is only used for BTF introspection, we can later check "what size
	* is the bus array" in the introspection data and thus extract the bus ID
	* again.
	*
	* And we use the __LINE__ to give each of our structs a unique name so the
	* BPF program writer doesn't have to.
	*
	* $ bpftool btf dump file target/bpf/HP_Elite_Presenter.bpf.o
	* shows the inspection data, start by searching for .hid_bpf_config
	* and working backwards from that (each entry references the type_id of the
	* content).
	*/

	#define HID_DEVICE(b, g, ven, prod) \
	struct { \
	__uint(name, 0); \
	__uint(bus, (b)); \
	__uint(group, (g)); \
	__uint(vid, (ven)); \
	__uint(pid, (prod)); \
	} COMBINE(_entry, __LINE__)

	/* Macro magic below is to make HID_BPF_CONFIG() look like a function call that
	* we can pass multiple HID_DEVICE() invocations in.
	*
	* For up to 16 arguments, HID_BPF_CONFIG(one, two) resolves to
	*
	* union {
	* HID_DEVICE(...);
	* HID_DEVICE(...);
	* } _device_ids SEC(".hid_bpf_config")
	*
	*/

	/* Returns the number of macro arguments, this expands
	* NARGS(a, b, c) to NTH_ARG(a, b, c, 15, 14, 13, .... 4, 3, 2, 1).
	* NTH_ARG always returns the 16th argument which in our case is 3.
	*
	* If we want more than 16 values _COUNTDOWN and _NTH_ARG both need to be
	* updated.
	*/
	#define _NARGS(...) _NARGS1(__VA_ARGS__, _COUNTDOWN)
	#define _NARGS1(...) _NTH_ARG(__VA_ARGS__)

	/* Add to this if we need more than 16 args */
	#define _COUNTDOWN \
	15, 14, 13, 12, 11, 10, 9, 8, \
	7, 6, 5, 4, 3, 2, 1, 0

	/* Return the 16 argument passed in. See _NARGS above for usage. Note this is
	* 1-indexed.
	*/
	#define _NTH_ARG( \
	_1, _2, _3, _4, _5, _6, _7, _8, \
	_9, _10, _11, _12, _13, _14, _15,\
	N, ...) N

	/* Turns EXPAND(_ARG, a, b, c) into _ARG3(a, b, c) */
	#define _EXPAND(func, ...) COMBINE(func, _NARGS(__VA_ARGS__)) (__VA_ARGS__)

	/* And now define all the ARG macros for each number of args we want to accept */
	#define _ARG1(_1) _1;
	#define _ARG2(_1, _2) _1; _2;
	#define _ARG3(_1, _2, _3) _1; _2; _3;
	#define _ARG4(_1, _2, _3, _4) _1; _2; _3; _4;
	#define _ARG5(_1, _2, _3, _4, _5) _1; _2; _3; _4; _5;
	#define _ARG6(_1, _2, _3, _4, _5, _6) _1; _2; _3; _4; _5; _6;
	#define _ARG7(_1, _2, _3, _4, _5, _6, _7) _1; _2; _3; _4; _5; _6; _7;
	#define _ARG8(_1, _2, _3, _4, _5, _6, _7, _8) _1; _2; _3; _4; _5; _6; _7; _8;
	#define _ARG9(_1, _2, _3, _4, _5, _6, _7, _8, _9) _1; _2; _3; _4; _5; _6; _7; _8; _9;
	#define _ARG10(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a;
	#define _ARG11(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b;
	#define _ARG12(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c;
	#define _ARG13(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d;
	#define _ARG14(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e;
	#define _ARG15(_1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, _d, _e, _f) _1; _2; _3; _4; _5; _6; _7; _8; _9; _a; _b; _c; _d; _e; _f;


	#define HID_BPF_CONFIG(...) union { \
	_EXPAND(_ARG, __VA_ARGS__) \
	} _device_ids SEC(".hid_bpf_config")

	#endif /* __HID_BPF_HELPERS_H */