From: Benjamin Tissoires <benjamin.tissoires@redhat.com>
To: Greg KH <gregkh@linuxfoundation.org>,
Jiri Kosina <jikos@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
Dave Marchevsky <davemarchevsky@fb.com>,
Joe Stringer <joe@cilium.io>, Jonathan Corbet <corbet@lwn.net>
Cc: Tero Kristo <tero.kristo@linux.intel.com>,
linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org,
Benjamin Tissoires <benjamin.tissoires@redhat.com>
Subject: [PATCH bpf-next v5 15/17] samples/bpf: add new hid_mouse example
Date: Wed, 18 May 2022 22:59:22 +0200 [thread overview]
Message-ID: <20220518205924.399291-16-benjamin.tissoires@redhat.com> (raw)
In-Reply-To: <20220518205924.399291-1-benjamin.tissoires@redhat.com>
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.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
changes in v5:
- bring back same features than v3, with the new API
changes in v4:
- dropped the not-yet-implemented rdesc_fixup
- use the new API
changes in v3:
- use the new hid_get_data API
- add a comment for the report descriptor fixup to explain what is done
changes in v2:
- split the series by bpf/libbpf/hid/selftests and samples
---
samples/bpf/.gitignore | 1 +
samples/bpf/Makefile | 23 ++++++
samples/bpf/hid_mouse.bpf.c | 134 ++++++++++++++++++++++++++++++
samples/bpf/hid_mouse.c | 157 ++++++++++++++++++++++++++++++++++++
4 files changed, 315 insertions(+)
create mode 100644 samples/bpf/hid_mouse.bpf.c
create mode 100644 samples/bpf/hid_mouse.c
diff --git a/samples/bpf/.gitignore b/samples/bpf/.gitignore
index 0e7bfdbff80a..65440bd618b2 100644
--- a/samples/bpf/.gitignore
+++ b/samples/bpf/.gitignore
@@ -2,6 +2,7 @@
cpustat
fds_example
hbm
+hid_mouse
ibumad
lathist
lwt_len_hist
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 03e3d3529ac9..dc74e26111f4 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -60,6 +60,8 @@ tprogs-y += xdp_redirect_map
tprogs-y += xdp_redirect
tprogs-y += xdp_monitor
+tprogs-y += hid_mouse
+
# Libbpf dependencies
LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
LIBBPF_OUTPUT = $(abspath $(BPF_SAMPLES_PATH))/libbpf
@@ -125,6 +127,8 @@ xdp_redirect-objs := xdp_redirect_user.o $(XDP_SAMPLE)
xdp_monitor-objs := xdp_monitor_user.o $(XDP_SAMPLE)
xdp_router_ipv4-objs := xdp_router_ipv4_user.o $(XDP_SAMPLE)
+hid_mouse-objs := hid_mouse.o
+
# Tell kbuild to always build the programs
always-y := $(tprogs-y)
always-y += sockex1_kern.o
@@ -349,6 +353,8 @@ $(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
$(obj)/hbm.o: $(src)/hbm.h
$(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+$(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h
+
# Override includes for xdp_sample_user.o because $(srctree)/usr/include in
# TPROGS_CFLAGS causes conflicts
XDP_SAMPLE_CFLAGS += -Wall -O2 \
@@ -433,6 +439,23 @@ $(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
@echo " BPF GEN-SKEL" $(@:.skel.h=)
$(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
+# Generate BPF skeletons for non XDP progs
+OTHER_BPF_SKELS := hid_mouse.skel.h
+
+hid_mouse.skel.h-deps := hid_mouse.bpf.o
+
+OTHER_BPF_SRCS_LINKED := $(patsubst %.skel.h,%.bpf.c, $(OTHER_BPF_SKELS))
+OTHER_BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(OTHER_BPF_SRCS_LINKED))
+OTHER_BPF_SKELS_LINKED := $(addprefix $(obj)/,$(OTHER_BPF_SKELS))
+
+$(OTHER_BPF_SKELS_LINKED): $(OTHER_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=_lskel)) > $@
+# $(call msg,GEN-SKEL,$@)
+# $(Q)$(BPFTOOL) gen skeleton $< > $@
+
# 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.
diff --git a/samples/bpf/hid_mouse.bpf.c b/samples/bpf/hid_mouse.bpf.c
new file mode 100644
index 000000000000..0113e603f7a7
--- /dev/null
+++ b/samples/bpf/hid_mouse.bpf.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+/* following are kfuncs exported by HID for HID-BPF */
+extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym;
+extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
+ unsigned int offset,
+ const size_t __sz) __ksym;
+extern void hid_bpf_data_release(__u8 *data) __ksym;
+extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx) __ksym;
+
+struct attach_prog_args {
+ int prog_fd;
+ unsigned int hid;
+ int retval;
+};
+
+SEC("syscall")
+int attach_prog(struct attach_prog_args *ctx)
+{
+ ctx->retval = hid_bpf_attach_prog(ctx->hid,
+ ctx->prog_fd,
+ 0);
+ return 0;
+}
+
+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/bpf/hid_mouse.c b/samples/bpf/hid_mouse.c
new file mode 100644
index 000000000000..a74e0dc45755
--- /dev/null
+++ b/samples/bpf/hid_mouse.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2022 Benjamin Tissoires
+ */
+
+/* not sure why but this doesn't get preoperly imported */
+#define __must_check
+
+#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_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "hid_mouse.skel.h"
+
+static bool running = true;
+
+struct attach_prog_args {
+ int prog_fd;
+ 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 /sys/bus/hid/devices/0BUS:0VID:0PID:00ID\n\n",
+ __func__, prog);
+}
+
+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_lskel *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_lskel__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);
+//
+//// err = bpf_obj_get_info_by_fd(progs[0].fd, &info, &info_len);
+//// if (err) {
+//// printf("can't get prog info - %s\n", strerror(errno));
+//// goto cleanup;
+//// }
+//
+ while (running)
+ ;
+
+// cleanup:
+// hid_mouse_lskel__destroy(skel);
+//
+// return err;
+}
--
2.36.1
next prev parent reply other threads:[~2022-05-18 21:01 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 20:59 [PATCH bpf-next v5 00/17] Introduce eBPF support for HID devices Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 01/17] bpf/btf: also allow kfunc in tracing and syscall programs Benjamin Tissoires
2022-05-21 2:34 ` Alexei Starovoitov
2022-05-18 20:59 ` [PATCH bpf-next v5 02/17] bpf/verifier: allow kfunc to return an allocated mem Benjamin Tissoires
2022-05-18 21:59 ` Kumar Kartikeya Dwivedi
2022-05-19 12:05 ` Benjamin Tissoires
2022-05-19 12:40 ` Kumar Kartikeya Dwivedi
2022-05-18 20:59 ` [PATCH bpf-next v5 03/17] bpf: prepare for more bpf syscall to be used from kernel and user space Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 04/17] libbpf: add map_get_fd_by_id and map_delete_elem in light skeleton Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 05/17] HID: core: store the unique system identifier in hid_device Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 06/17] HID: export hid_report_type to uapi Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 07/17] HID: initial BPF implementation Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 08/17] selftests/bpf: add tests for the HID-bpf initial implementation Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 09/17] HID: bpf: allocate data memory for device_event BPF programs Benjamin Tissoires
2022-05-18 23:13 ` kernel test robot
2022-05-18 20:59 ` [PATCH bpf-next v5 10/17] selftests/bpf/hid: add test to change the report size Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 11/17] HID: bpf: introduce hid_hw_request() Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 12/17] selftests/bpf: add tests for bpf_hid_hw_request Benjamin Tissoires
2022-05-18 22:20 ` Kumar Kartikeya Dwivedi
2022-05-19 12:12 ` Benjamin Tissoires
2022-05-19 12:51 ` Kumar Kartikeya Dwivedi
2022-05-19 13:13 ` Benjamin Tissoires
2022-05-19 13:44 ` Kumar Kartikeya Dwivedi
2022-05-19 15:47 ` Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 13/17] HID: bpf: allow to change the report descriptor Benjamin Tissoires
2022-05-21 2:46 ` Alexei Starovoitov
2022-05-18 20:59 ` [PATCH bpf-next v5 14/17] selftests/bpf: add report descriptor fixup tests Benjamin Tissoires
2022-05-18 20:59 ` Benjamin Tissoires [this message]
2022-05-18 20:59 ` [PATCH bpf-next v5 16/17] selftests/bpf: Add a test for BPF_F_INSERT_HEAD Benjamin Tissoires
2022-05-18 20:59 ` [PATCH bpf-next v5 17/17] Documentation: add HID-BPF docs Benjamin Tissoires
2022-05-19 8:10 ` [PATCH bpf-next v5 00/17] Introduce eBPF support for HID devices Christoph Hellwig
2022-05-19 8:20 ` Greg KH
2022-05-19 8:38 ` Christoph Hellwig
2022-05-19 10:20 ` Benjamin Tissoires
2022-05-19 10:43 ` Toke Høiland-Jørgensen
2022-05-19 11:56 ` Benjamin Tissoires
2022-05-21 0:18 ` Alexei Starovoitov
2022-05-19 10:32 ` Greg KH
2022-05-19 11:46 ` Benjamin Tissoires
2022-05-21 2:40 ` patchwork-bot+netdevbpf
2022-05-27 7:26 ` Tero Kristo
2022-05-30 15:49 ` Benjamin Tissoires
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