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-rw-r--r--samples/hid/hid_mouse.c155
1 files changed, 155 insertions, 0 deletions
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 <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;
+}