From 6008105b4f4e470da0e9159a3a74ca7ff6e869ba Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Thu, 3 Nov 2022 16:57:54 +0100 Subject: 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 Signed-off-by: Jiri Kosina --- samples/hid/.gitignore | 7 ++ samples/hid/Makefile | 246 +++++++++++++++++++++++++++++++++++++++ samples/hid/Makefile.target | 75 ++++++++++++ samples/hid/hid_bpf_attach.bpf.c | 18 +++ samples/hid/hid_bpf_attach.h | 14 +++ samples/hid/hid_bpf_helpers.h | 19 +++ samples/hid/hid_mouse.bpf.c | 112 ++++++++++++++++++ samples/hid/hid_mouse.c | 155 ++++++++++++++++++++++++ 8 files changed, 646 insertions(+) create mode 100644 samples/hid/.gitignore create mode 100644 samples/hid/Makefile create mode 100644 samples/hid/Makefile.target create mode 100644 samples/hid/hid_bpf_attach.bpf.c create mode 100644 samples/hid/hid_bpf_attach.h create mode 100644 samples/hid/hid_bpf_helpers.h create mode 100644 samples/hid/hid_mouse.bpf.c create mode 100644 samples/hid/hid_mouse.c (limited to 'samples') diff --git a/samples/hid/.gitignore b/samples/hid/.gitignore new file mode 100644 index 000000000000..8cb45592e29a --- /dev/null +++ b/samples/hid/.gitignore @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +hid_mouse +*.out +*.skel.h +/vmlinux.h +/bpftool/ +/libbpf/ diff --git a/samples/hid/Makefile b/samples/hid/Makefile new file mode 100644 index 000000000000..8fe6ccfc5f29 --- /dev/null +++ b/samples/hid/Makefile @@ -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 \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 - &1 \ + | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \ +$(shell $(1) -dM -E - $@ + +# asm/sysreg.h - inline assembly used by it is incompatible with llvm. +# But, there is no easy way to fix it, so just exclude it since it is +# useless for BPF samples. +# below we use long chain of commands, clang | opt | llvm-dis | llc, +# to generate final object file. 'clang' compiles the source into IR +# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin +# processing (llvm12) and IR optimizations. 'llvm-dis' converts +# 'opt' output to IR, and finally 'llc' generates bpf byte code. +$(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 diff --git a/samples/hid/Makefile.target b/samples/hid/Makefile.target new file mode 100644 index 000000000000..7621f55e2947 --- /dev/null +++ b/samples/hid/Makefile.target @@ -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) diff --git a/samples/hid/hid_bpf_attach.bpf.c b/samples/hid/hid_bpf_attach.bpf.c new file mode 100644 index 000000000000..d4dce4ea7c6e --- /dev/null +++ b/samples/hid/hid_bpf_attach.bpf.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2022 Benjamin Tissoires + */ + +#include "vmlinux.h" +#include +#include +#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; +} diff --git a/samples/hid/hid_bpf_attach.h b/samples/hid/hid_bpf_attach.h new file mode 100644 index 000000000000..35bb28b49264 --- /dev/null +++ b/samples/hid/hid_bpf_attach.h @@ -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 */ diff --git a/samples/hid/hid_bpf_helpers.h b/samples/hid/hid_bpf_helpers.h new file mode 100644 index 000000000000..c555aeef5e37 --- /dev/null +++ b/samples/hid/hid_bpf_helpers.h @@ -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 */ diff --git a/samples/hid/hid_mouse.bpf.c b/samples/hid/hid_mouse.bpf.c new file mode 100644 index 000000000000..7c8b453ccb16 --- /dev/null +++ b/samples/hid/hid_mouse.bpf.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include +#include +#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"; diff --git a/samples/hid/hid_mouse.c b/samples/hid/hid_mouse.c new file mode 100644 index 000000000000..018f1185f203 --- /dev/null +++ b/samples/hid/hid_mouse.c @@ -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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include + +#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; +} -- cgit v1.2.3-70-g09d2 From a56a256933bb0b593dc36fc8d7bb85ada3655662 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Thu, 3 Nov 2022 16:57:55 +0100 Subject: samples/hid: add Surface Dial example Add a more complete HID-BPF example. Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- samples/hid/.gitignore | 1 + samples/hid/Makefile | 6 +- samples/hid/hid_bpf_helpers.h | 2 + samples/hid/hid_surface_dial.bpf.c | 134 ++++++++++++++++++++++ samples/hid/hid_surface_dial.c | 226 +++++++++++++++++++++++++++++++++++++ 5 files changed, 368 insertions(+), 1 deletion(-) create mode 100644 samples/hid/hid_surface_dial.bpf.c create mode 100644 samples/hid/hid_surface_dial.c (limited to 'samples') diff --git a/samples/hid/.gitignore b/samples/hid/.gitignore index 8cb45592e29a..3ea0fed3bbad 100644 --- a/samples/hid/.gitignore +++ b/samples/hid/.gitignore @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only hid_mouse +hid_surface_dial *.out *.skel.h /vmlinux.h diff --git a/samples/hid/Makefile b/samples/hid/Makefile index 8fe6ccfc5f29..026288280a03 100644 --- a/samples/hid/Makefile +++ b/samples/hid/Makefile @@ -7,6 +7,7 @@ pound := \# # List of programs to build tprogs-y += hid_mouse +tprogs-y += hid_surface_dial # Libbpf dependencies LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf @@ -19,6 +20,7 @@ EXTRA_HEADERS := hid_bpf_attach.h EXTRA_BPF_HEADERS := hid_bpf_helpers.h hid_mouse-objs := hid_mouse.o +hid_surface_dial-objs := hid_surface_dial.o # Tell kbuild to always build the programs always-y := $(tprogs-y) @@ -156,6 +158,7 @@ libbpf_hdrs: $(LIBBPF) .PHONY: libbpf_hdrs $(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h +$(obj)/hid_surface_dial.o: $(obj)/hid_surface_dial.skel.h -include $(HID_SAMPLES_PATH)/Makefile.target @@ -201,10 +204,11 @@ $(obj)/%.bpf.o: $(src)/%.bpf.c $(EXTRA_BPF_HEADERS_SRC) $(obj)/vmlinux.h -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \ -c $(filter %.bpf.c,$^) -o $@ -LINKED_SKELS := hid_mouse.skel.h +LINKED_SKELS := hid_mouse.skel.h hid_surface_dial.skel.h clean-files += $(LINKED_SKELS) hid_mouse.skel.h-deps := hid_mouse.bpf.o hid_bpf_attach.bpf.o +hid_surface_dial.skel.h-deps := hid_surface_dial.bpf.o hid_bpf_attach.bpf.o LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps))) diff --git a/samples/hid/hid_bpf_helpers.h b/samples/hid/hid_bpf_helpers.h index c555aeef5e37..4fff31dbe0e7 100644 --- a/samples/hid/hid_bpf_helpers.h +++ b/samples/hid/hid_bpf_helpers.h @@ -10,6 +10,8 @@ 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 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, diff --git a/samples/hid/hid_surface_dial.bpf.c b/samples/hid/hid_surface_dial.bpf.c new file mode 100644 index 000000000000..1f80478c0918 --- /dev/null +++ b/samples/hid/hid_surface_dial.bpf.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2022 Benjamin Tissoires + */ + +#include "vmlinux.h" +#include +#include +#include "hid_bpf_helpers.h" + +#define HID_UP_BUTTON 0x0009 +#define HID_GD_WHEEL 0x0038 + +SEC("fmod_ret/hid_bpf_device_event") +int BPF_PROG(hid_event, struct hid_bpf_ctx *hctx) +{ + __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 9 /* size */); + + if (!data) + return 0; /* EPERM check */ + + /* Touch */ + data[1] &= 0xfd; + + /* X */ + data[4] = 0; + data[5] = 0; + + /* Y */ + data[6] = 0; + data[7] = 0; + + return 0; +} + +/* 72 == 360 / 5 -> 1 report every 5 degrees */ +int resolution = 72; +int physical = 5; + +struct haptic_syscall_args { + unsigned int hid; + int retval; +}; + +static __u8 haptic_data[8]; + +SEC("syscall") +int set_haptic(struct haptic_syscall_args *args) +{ + struct hid_bpf_ctx *ctx; + const size_t size = sizeof(haptic_data); + u16 *res; + int ret; + + if (size > sizeof(haptic_data)) + return -7; /* -E2BIG */ + + ctx = hid_bpf_allocate_context(args->hid); + if (!ctx) + return -1; /* EPERM check */ + + haptic_data[0] = 1; /* report ID */ + + ret = hid_bpf_hw_request(ctx, haptic_data, size, HID_FEATURE_REPORT, HID_REQ_GET_REPORT); + + bpf_printk("probed/remove event ret value: %d", ret); + bpf_printk("buf: %02x %02x %02x", + haptic_data[0], + haptic_data[1], + haptic_data[2]); + bpf_printk(" %02x %02x %02x", + haptic_data[3], + haptic_data[4], + haptic_data[5]); + bpf_printk(" %02x %02x", + haptic_data[6], + haptic_data[7]); + + /* whenever resolution multiplier is not 3600, we have the fixed report descriptor */ + res = (u16 *)&haptic_data[1]; + if (*res != 3600) { +// haptic_data[1] = 72; /* resolution multiplier */ +// haptic_data[2] = 0; /* resolution multiplier */ +// haptic_data[3] = 0; /* Repeat Count */ + haptic_data[4] = 3; /* haptic Auto Trigger */ +// haptic_data[5] = 5; /* Waveform Cutoff Time */ +// haptic_data[6] = 80; /* Retrigger Period */ +// haptic_data[7] = 0; /* Retrigger Period */ + } else { + haptic_data[4] = 0; + } + + ret = hid_bpf_hw_request(ctx, haptic_data, size, HID_FEATURE_REPORT, HID_REQ_SET_REPORT); + + bpf_printk("set haptic ret value: %d -> %d", ret, haptic_data[4]); + + args->retval = ret; + + hid_bpf_release_context(ctx); + + return 0; +} + +/* Convert REL_DIAL into REL_WHEEL */ +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 */); + __u16 *res, *phys; + + if (!data) + return 0; /* EPERM check */ + + /* Convert TOUCH into a button */ + data[31] = HID_UP_BUTTON; + data[33] = 2; + + /* Convert REL_DIAL into REL_WHEEL */ + data[45] = HID_GD_WHEEL; + + /* Change Resolution Multiplier */ + phys = (__u16 *)&data[61]; + *phys = physical; + res = (__u16 *)&data[66]; + *res = resolution; + + /* Convert X,Y from Abs to Rel */ + data[88] = 0x06; + data[98] = 0x06; + + return 0; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = 1; diff --git a/samples/hid/hid_surface_dial.c b/samples/hid/hid_surface_dial.c new file mode 100644 index 000000000000..bceea53d39b0 --- /dev/null +++ b/samples/hid/hid_surface_dial.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2022 Benjamin Tissoires + * + * This program will morph the Microsoft Surface Dial into a mouse, + * and depending on the chosen resolution enable or not the haptic feedback: + * - a resolution (-r) of 3600 will report 3600 "ticks" in one full rotation + * wihout haptic feedback + * - any other resolution will report N "ticks" in a full rotation with haptic + * feedback + * + * A good default for low resolution haptic scrolling is 72 (1 "tick" every 5 + * degrees), and set to 3600 for smooth scrolling. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include + +#include "hid_surface_dial.skel.h" +#include "hid_bpf_attach.h" + +static bool running = true; + +struct haptic_syscall_args { + unsigned int hid; + int retval; +}; + +static void int_exit(int sig) +{ + running = false; + exit(0); +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "%s: %s [OPTIONS] /sys/bus/hid/devices/0BUS:0VID:0PID:00ID\n\n" + " OPTIONS:\n" + " -r N\t set the given resolution to the device (number of ticks per 360°)\n\n", + __func__, prog); + fprintf(stderr, + "This program will morph the Microsoft Surface Dial into a mouse,\n" + "and depending on the chosen resolution enable or not the haptic feedback:\n" + "- a resolution (-r) of 3600 will report 3600 'ticks' in one full rotation\n" + " wihout haptic feedback\n" + "- any other resolution will report N 'ticks' in a full rotation with haptic\n" + " feedback\n" + "\n" + "A good default for low resolution haptic scrolling is 72 (1 'tick' every 5\n" + "degrees), and set to 3600 for smooth scrolling.\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); +} + +static int attach_prog(struct hid_surface_dial *skel, struct bpf_program *prog, int hid_id) +{ + struct attach_prog_args args = { + .hid = hid_id, + .retval = -1, + }; + int attach_fd, err; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); + + attach_fd = bpf_program__fd(skel->progs.attach_prog); + if (attach_fd < 0) { + fprintf(stderr, "can't locate attach prog: %m\n"); + return 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; + } + return 0; +} + +static int set_haptic(struct hid_surface_dial *skel, int hid_id) +{ + struct haptic_syscall_args args = { + .hid = hid_id, + .retval = -1, + }; + int haptic_fd, err; + DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr, + .ctx_in = &args, + .ctx_size_in = sizeof(args), + ); + + haptic_fd = bpf_program__fd(skel->progs.set_haptic); + if (haptic_fd < 0) { + fprintf(stderr, "can't locate haptic prog: %m\n"); + return 1; + } + + err = bpf_prog_test_run_opts(haptic_fd, &tattr); + if (err) { + fprintf(stderr, "can't set haptic configuration to hid device %d: %m (err: %d)\n", + hid_id, err); + return 1; + } + return 0; +} + +int main(int argc, char **argv) +{ + struct hid_surface_dial *skel; + struct bpf_program *prog; + const char *optstr = "r:"; + const char *sysfs_path; + int opt, hid_id, resolution = 72; + + while ((opt = getopt(argc, argv, optstr)) != -1) { + switch (opt) { + case 'r': + { + char *endp = NULL; + long l = -1; + + if (optarg) { + l = strtol(optarg, &endp, 10); + if (endp && *endp) + l = -1; + } + + if (l < 0) { + fprintf(stderr, + "invalid r option %s - expecting a number\n", + optarg ? optarg : ""); + exit(EXIT_FAILURE); + }; + + resolution = (int) l; + break; + } + 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_surface_dial__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; + } + + skel->data->resolution = resolution; + skel->data->physical = (int)(resolution / 72); + + bpf_object__for_each_program(prog, *skel->skeleton->obj) { + /* ignore syscalls */ + if (bpf_program__get_type(prog) != BPF_PROG_TYPE_TRACING) + continue; + + attach_prog(skel, prog, hid_id); + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + set_haptic(skel, hid_id); + + while (running) + sleep(1); + + hid_surface_dial__destroy(skel); + + return 0; +} -- cgit v1.2.3-70-g09d2 From 2364b5060d780476b7455f38e3a2c7e14cc3406e Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Wed, 16 Nov 2022 09:39:43 +0000 Subject: samples/hid: Fix spelling mistake "wihout" -> "without" There is a spelling mistake in a comment and a usage message. Fix them. Signed-off-by: Colin Ian King Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- samples/hid/hid_surface_dial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'samples') diff --git a/samples/hid/hid_surface_dial.c b/samples/hid/hid_surface_dial.c index bceea53d39b0..4bc97373a708 100644 --- a/samples/hid/hid_surface_dial.c +++ b/samples/hid/hid_surface_dial.c @@ -4,7 +4,7 @@ * This program will morph the Microsoft Surface Dial into a mouse, * and depending on the chosen resolution enable or not the haptic feedback: * - a resolution (-r) of 3600 will report 3600 "ticks" in one full rotation - * wihout haptic feedback + * without haptic feedback * - any other resolution will report N "ticks" in a full rotation with haptic * feedback * @@ -57,7 +57,7 @@ static void usage(const char *prog) "This program will morph the Microsoft Surface Dial into a mouse,\n" "and depending on the chosen resolution enable or not the haptic feedback:\n" "- a resolution (-r) of 3600 will report 3600 'ticks' in one full rotation\n" - " wihout haptic feedback\n" + " without haptic feedback\n" "- any other resolution will report N 'ticks' in a full rotation with haptic\n" " feedback\n" "\n" -- cgit v1.2.3-70-g09d2