samples/hid: add new hid BPF example

Everything should be available in the selftest part of the tree, but
providing an example without uhid and hidraw will be more easy to
follow for users.

This example will probably ever only work on the Etekcity Scroll 6E
because we need to adapt the various raw values to the actual device.

On that device, the X and Y axis will be swapped and inverted, and on
any other device, chances are high that the device will not work until
Ctrl-C is hit.

The Makefiles are taken from samples/bpf to not reinvent the wheel and
to force using in-kernel libbpf and bpftool.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Benjamin Tissoires 2022-11-03 16:57:54 +01:00 committed by Jiri Kosina
parent 80e189f2af
commit 6008105b4f
9 changed files with 647 additions and 0 deletions

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@ -9100,6 +9100,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git
F: drivers/hid/
F: include/linux/hid*
F: include/uapi/linux/hid*
F: samples/hid/
F: tools/testing/selftests/hid/
HID LOGITECH DRIVERS

7
samples/hid/.gitignore vendored Normal file
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@ -0,0 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
hid_mouse
*.out
*.skel.h
/vmlinux.h
/bpftool/
/libbpf/

246
samples/hid/Makefile Normal file
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@ -0,0 +1,246 @@
# SPDX-License-Identifier: GPL-2.0
HID_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
TOOLS_PATH := $(HID_SAMPLES_PATH)/../../tools
pound := \#
# List of programs to build
tprogs-y += hid_mouse
# Libbpf dependencies
LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
LIBBPF_OUTPUT = $(abspath $(HID_SAMPLES_PATH))/libbpf
LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a
EXTRA_HEADERS := hid_bpf_attach.h
EXTRA_BPF_HEADERS := hid_bpf_helpers.h
hid_mouse-objs := hid_mouse.o
# Tell kbuild to always build the programs
always-y := $(tprogs-y)
ifeq ($(ARCH), arm)
# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
# headers when arm instruction set identification is requested.
ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
endif
ifeq ($(ARCH), mips)
TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__
ifdef CONFIG_MACH_LOONGSON64
BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-loongson64
BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
endif
endif
TPROGS_CFLAGS += -Wall -O2
TPROGS_CFLAGS += -Wmissing-prototypes
TPROGS_CFLAGS += -Wstrict-prototypes
TPROGS_CFLAGS += -I$(objtree)/usr/include
TPROGS_CFLAGS += -I$(LIBBPF_INCLUDE)
TPROGS_CFLAGS += -I$(srctree)/tools/include
ifdef SYSROOT
TPROGS_CFLAGS += --sysroot=$(SYSROOT)
TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
endif
TPROGS_LDLIBS += $(LIBBPF) -lelf -lz
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
LLC ?= llc
CLANG ?= clang
OPT ?= opt
LLVM_DIS ?= llvm-dis
LLVM_OBJCOPY ?= llvm-objcopy
LLVM_READELF ?= llvm-readelf
BTF_PAHOLE ?= pahole
# Detect that we're cross compiling and use the cross compiler
ifdef CROSS_COMPILE
CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
endif
# Don't evaluate probes and warnings if we need to run make recursively
ifneq ($(src),)
HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
-o /dev/null 2>/dev/null && echo okay)
ifeq ($(HDR_PROBE),)
$(warning WARNING: Detected possible issues with include path.)
$(warning WARNING: Please install kernel headers locally (make headers_install).)
endif
BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
$(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
$(LLVM_READELF) -S ./llvm_btf_verify.o | grep BTF; \
/bin/rm -f ./llvm_btf_verify.o)
BPF_EXTRA_CFLAGS += -fno-stack-protector
ifneq ($(BTF_LLVM_PROBE),)
BPF_EXTRA_CFLAGS += -g
else
ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
BPF_EXTRA_CFLAGS += -g
LLC_FLAGS += -mattr=dwarfris
DWARF2BTF = y
endif
endif
endif
# Trick to allow make to be run from this directory
all:
$(MAKE) -C ../../ M=$(CURDIR) HID_SAMPLES_PATH=$(CURDIR)
clean:
$(MAKE) -C ../../ M=$(CURDIR) clean
@find $(CURDIR) -type f -name '*~' -delete
@$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool
$(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
# Fix up variables inherited from Kbuild that tools/ build system won't like
$(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \
LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(HID_SAMPLES_PATH)/../../ \
O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
$@ install_headers
BPFTOOLDIR := $(TOOLS_PATH)/bpf/bpftool
BPFTOOL_OUTPUT := $(abspath $(HID_SAMPLES_PATH))/bpftool
BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool
$(BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) | $(BPFTOOL_OUTPUT)
$(MAKE) -C $(BPFTOOLDIR) srctree=$(HID_SAMPLES_PATH)/../../ \
OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap
$(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
$(call msg,MKDIR,$@)
$(Q)mkdir -p $@
FORCE:
# Verify LLVM compiler tools are available and bpf target is supported by llc
.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
verify_cmds: $(CLANG) $(LLC)
@for TOOL in $^ ; do \
if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
exit 1; \
else true; fi; \
done
verify_target_bpf: verify_cmds
@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
echo " NOTICE: LLVM version >= 3.7.1 required" ;\
exit 2; \
else true; fi
$(HID_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
$(src)/*.c: verify_target_bpf $(LIBBPF)
libbpf_hdrs: $(LIBBPF)
.PHONY: libbpf_hdrs
$(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h
-include $(HID_SAMPLES_PATH)/Makefile.target
VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux)) \
$(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)) \
$(abspath ./vmlinux)
VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
ifeq ($(VMLINUX_H),)
ifeq ($(VMLINUX_BTF),)
$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
build the kernel or set VMLINUX_BTF or VMLINUX_H variable)
endif
$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
else
$(Q)cp "$(VMLINUX_H)" $@
endif
clean-files += vmlinux.h
# Get Clang's default includes on this system, as opposed to those seen by
# '-target bpf'. This fixes "missing" files on some architectures/distros,
# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
#
# Use '-idirafter': Don't interfere with include mechanics except where the
# build would have failed anyways.
define get_sys_includes
$(shell $(1) -v -E - </dev/null 2>&1 \
| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
$(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/')
endef
CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
EXTRA_BPF_HEADERS_SRC := $(addprefix $(src)/,$(EXTRA_BPF_HEADERS))
$(obj)/%.bpf.o: $(src)/%.bpf.c $(EXTRA_BPF_HEADERS_SRC) $(obj)/vmlinux.h
@echo " CLANG-BPF " $@
$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(SRCARCH) \
-Wno-compare-distinct-pointer-types -I$(srctree)/include \
-I$(srctree)/samples/bpf -I$(srctree)/tools/include \
-I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
-c $(filter %.bpf.c,$^) -o $@
LINKED_SKELS := hid_mouse.skel.h
clean-files += $(LINKED_SKELS)
hid_mouse.skel.h-deps := hid_mouse.bpf.o hid_bpf_attach.bpf.o
LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
BPF_SRCS_LINKED := $(notdir $(wildcard $(src)/*.bpf.c))
BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(BPF_SRCS_LINKED))
BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS))
$(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
@echo " BPF GEN-OBJ " $(@:.skel.h=)
$(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
@echo " BPF GEN-SKEL" $(@:.skel.h=)
$(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
# But, there is no easy way to fix it, so just exclude it since it is
# useless for BPF samples.
# below we use long chain of commands, clang | opt | llvm-dis | llc,
# to generate final object file. 'clang' compiles the source into IR
# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
# processing (llvm12) and IR optimizations. 'llvm-dis' converts
# 'opt' output to IR, and finally 'llc' generates bpf byte code.
$(obj)/%.o: $(src)/%.c
@echo " CLANG-bpf " $@
$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
-I$(LIBBPF_INCLUDE) \
-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
-Wno-gnu-variable-sized-type-not-at-end \
-Wno-address-of-packed-member -Wno-tautological-compare \
-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
-fno-asynchronous-unwind-tables \
-I$(srctree)/samples/hid/ \
-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
$(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
ifeq ($(DWARF2BTF),y)
$(BTF_PAHOLE) -J $@
endif

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@ -0,0 +1,75 @@
# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Building binaries on the host system
# Binaries are not used during the compilation of the kernel, and intended
# to be build for target board, target board can be host of course. Added to
# build binaries to run not on host system.
#
# Sample syntax
# tprogs-y := xsk_example
# Will compile xsk_example.c and create an executable named xsk_example
#
# tprogs-y := xdpsock
# xdpsock-objs := xdpsock_1.o xdpsock_2.o
# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable
# xdpsock, based on xdpsock_1.o and xdpsock_2.o
#
# Derived from scripts/Makefile.host
#
__tprogs := $(sort $(tprogs-y))
# C code
# Executables compiled from a single .c file
tprog-csingle := $(foreach m,$(__tprogs), \
$(if $($(m)-objs),,$(m)))
# C executables linked based on several .o files
tprog-cmulti := $(foreach m,$(__tprogs),\
$(if $($(m)-objs),$(m)))
# Object (.o) files compiled from .c files
tprog-cobjs := $(sort $(foreach m,$(__tprogs),$($(m)-objs)))
tprog-csingle := $(addprefix $(obj)/,$(tprog-csingle))
tprog-cmulti := $(addprefix $(obj)/,$(tprog-cmulti))
tprog-cobjs := $(addprefix $(obj)/,$(tprog-cobjs))
#####
# Handle options to gcc. Support building with separate output directory
_tprogc_flags = $(TPROGS_CFLAGS) \
$(TPROGCFLAGS_$(basetarget).o)
# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifdef building_out_of_srctree
_tprogc_flags += -I $(objtree)/$(obj)
endif
endif
tprogc_flags = -Wp,-MD,$(depfile) $(_tprogc_flags)
# Create executable from a single .c file
# tprog-csingle -> Executable
quiet_cmd_tprog-csingle = CC $@
cmd_tprog-csingle = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ $< \
$(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE
$(call if_changed_dep,tprog-csingle)
# Link an executable based on list of .o files, all plain c
# tprog-cmulti -> executable
quiet_cmd_tprog-cmulti = LD $@
cmd_tprog-cmulti = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \
$(addprefix $(obj)/,$($(@F)-objs)) \
$(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
$(tprog-cmulti): $(tprog-cobjs) FORCE
$(call if_changed,tprog-cmulti)
$(call multi_depend, $(tprog-cmulti), , -objs)
# Create .o file from a single .c file
# tprog-cobjs -> .o
quiet_cmd_tprog-cobjs = CC $@
cmd_tprog-cobjs = $(CC) $(tprogc_flags) -c -o $@ $<
$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE
$(call if_changed_dep,tprog-cobjs)

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@ -0,0 +1,18 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2022 Benjamin Tissoires
*/
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "hid_bpf_attach.h"
#include "hid_bpf_helpers.h"
SEC("syscall")
int attach_prog(struct attach_prog_args *ctx)
{
ctx->retval = hid_bpf_attach_prog(ctx->hid,
ctx->prog_fd,
0);
return 0;
}

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@ -0,0 +1,14 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2022 Benjamin Tissoires
*/
#ifndef __HID_BPF_ATTACH_H
#define __HID_BPF_ATTACH_H
struct attach_prog_args {
int prog_fd;
unsigned int hid;
int retval;
};
#endif /* __HID_BPF_ATTACH_H */

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@ -0,0 +1,19 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2022 Benjamin Tissoires
*/
#ifndef __HID_BPF_HELPERS_H
#define __HID_BPF_HELPERS_H
/* 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) __ksym;
extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __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;
#endif /* __HID_BPF_HELPERS_H */

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samples/hid/hid_mouse.bpf.c Normal file
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@ -0,0 +1,112 @@
// SPDX-License-Identifier: GPL-2.0
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "hid_bpf_helpers.h"
SEC("fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_y_event, struct hid_bpf_ctx *hctx)
{
s16 y;
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 9 /* size */);
if (!data)
return 0; /* EPERM check */
bpf_printk("event: size: %d", hctx->size);
bpf_printk("incoming event: %02x %02x %02x",
data[0],
data[1],
data[2]);
bpf_printk(" %02x %02x %02x",
data[3],
data[4],
data[5]);
bpf_printk(" %02x %02x %02x",
data[6],
data[7],
data[8]);
y = data[3] | (data[4] << 8);
y = -y;
data[3] = y & 0xFF;
data[4] = (y >> 8) & 0xFF;
bpf_printk("modified event: %02x %02x %02x",
data[0],
data[1],
data[2]);
bpf_printk(" %02x %02x %02x",
data[3],
data[4],
data[5]);
bpf_printk(" %02x %02x %02x",
data[6],
data[7],
data[8]);
return 0;
}
SEC("fmod_ret/hid_bpf_device_event")
int BPF_PROG(hid_x_event, struct hid_bpf_ctx *hctx)
{
s16 x;
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 9 /* size */);
if (!data)
return 0; /* EPERM check */
x = data[1] | (data[2] << 8);
x = -x;
data[1] = x & 0xFF;
data[2] = (x >> 8) & 0xFF;
return 0;
}
SEC("fmod_ret/hid_bpf_rdesc_fixup")
int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */);
if (!data)
return 0; /* EPERM check */
bpf_printk("rdesc: %02x %02x %02x",
data[0],
data[1],
data[2]);
bpf_printk(" %02x %02x %02x",
data[3],
data[4],
data[5]);
bpf_printk(" %02x %02x %02x ...",
data[6],
data[7],
data[8]);
/*
* The original report descriptor contains:
*
* 0x05, 0x01, // Usage Page (Generic Desktop) 30
* 0x16, 0x01, 0x80, // Logical Minimum (-32767) 32
* 0x26, 0xff, 0x7f, // Logical Maximum (32767) 35
* 0x09, 0x30, // Usage (X) 38
* 0x09, 0x31, // Usage (Y) 40
*
* So byte 39 contains Usage X and byte 41 Usage Y.
*
* We simply swap the axes here.
*/
data[39] = 0x31;
data[41] = 0x30;
return 0;
}
char _license[] SEC("license") = "GPL";

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@ -0,0 +1,155 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2022 Benjamin Tissoires
*
* This is a pure HID-BPF example, and should be considered as such:
* on the Etekcity Scroll 6E, the X and Y axes will be swapped and
* inverted. On any other device... Not sure what this will do.
*
* This C main file is generic though. To adapt the code and test, users
* must amend only the .bpf.c file, which this program will load any
* eBPF program it finds.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <linux/errno.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "hid_mouse.skel.h"
#include "hid_bpf_attach.h"
static bool running = true;
static void int_exit(int sig)
{
running = false;
exit(0);
}
static void usage(const char *prog)
{
fprintf(stderr,
"%s: %s /sys/bus/hid/devices/0BUS:0VID:0PID:00ID\n\n",
__func__, prog);
fprintf(stderr,
"This program will upload and attach a HID-BPF program to the given device.\n"
"On the Etekcity Scroll 6E, the X and Y axis will be inverted, but on any other\n"
"device, chances are high that the device will not be working anymore\n\n"
"consider this as a demo and adapt the eBPF program to your needs\n"
"Hit Ctrl-C to unbind the program and reset the device\n");
}
static int get_hid_id(const char *path)
{
const char *str_id, *dir;
char uevent[1024];
int fd;
memset(uevent, 0, sizeof(uevent));
snprintf(uevent, sizeof(uevent) - 1, "%s/uevent", path);
fd = open(uevent, O_RDONLY | O_NONBLOCK);
if (fd < 0)
return -ENOENT;
close(fd);
dir = basename((char *)path);
str_id = dir + sizeof("0003:0001:0A37.");
return (int)strtol(str_id, NULL, 16);
}
int main(int argc, char **argv)
{
struct hid_mouse *skel;
struct bpf_program *prog;
int err;
const char *optstr = "";
const char *sysfs_path;
int opt, hid_id, attach_fd;
struct attach_prog_args args = {
.retval = -1,
};
DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr,
.ctx_in = &args,
.ctx_size_in = sizeof(args),
);
while ((opt = getopt(argc, argv, optstr)) != -1) {
switch (opt) {
default:
usage(basename(argv[0]));
return 1;
}
}
if (optind == argc) {
usage(basename(argv[0]));
return 1;
}
sysfs_path = argv[optind];
if (!sysfs_path) {
perror("sysfs");
return 1;
}
skel = hid_mouse__open_and_load();
if (!skel) {
fprintf(stderr, "%s %s:%d", __func__, __FILE__, __LINE__);
return -1;
}
hid_id = get_hid_id(sysfs_path);
if (hid_id < 0) {
fprintf(stderr, "can not open HID device: %m\n");
return 1;
}
args.hid = hid_id;
attach_fd = bpf_program__fd(skel->progs.attach_prog);
if (attach_fd < 0) {
fprintf(stderr, "can't locate attach prog: %m\n");
return 1;
}
bpf_object__for_each_program(prog, *skel->skeleton->obj) {
/* ignore syscalls */
if (bpf_program__get_type(prog) != BPF_PROG_TYPE_TRACING)
continue;
args.retval = -1;
args.prog_fd = bpf_program__fd(prog);
err = bpf_prog_test_run_opts(attach_fd, &tattr);
if (err) {
fprintf(stderr, "can't attach prog to hid device %d: %m (err: %d)\n",
hid_id, err);
return 1;
}
}
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
while (running)
sleep(1);
hid_mouse__destroy(skel);
return 0;
}