Commit | Line | Data |
---|---|---|
6008105b BT |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Copyright (c) 2022 Benjamin Tissoires | |
3 | * | |
4 | * This is a pure HID-BPF example, and should be considered as such: | |
5 | * on the Etekcity Scroll 6E, the X and Y axes will be swapped and | |
6 | * inverted. On any other device... Not sure what this will do. | |
7 | * | |
8 | * This C main file is generic though. To adapt the code and test, users | |
9 | * must amend only the .bpf.c file, which this program will load any | |
10 | * eBPF program it finds. | |
11 | */ | |
12 | ||
13 | #include <assert.h> | |
14 | #include <errno.h> | |
15 | #include <fcntl.h> | |
16 | #include <libgen.h> | |
17 | #include <signal.h> | |
18 | #include <stdbool.h> | |
19 | #include <stdio.h> | |
20 | #include <stdlib.h> | |
21 | #include <string.h> | |
22 | #include <sys/resource.h> | |
23 | #include <unistd.h> | |
24 | ||
25 | #include <linux/bpf.h> | |
26 | #include <linux/errno.h> | |
27 | ||
28 | #include <bpf/bpf.h> | |
29 | #include <bpf/libbpf.h> | |
30 | ||
31 | #include "hid_mouse.skel.h" | |
32 | #include "hid_bpf_attach.h" | |
33 | ||
34 | static bool running = true; | |
35 | ||
36 | static void int_exit(int sig) | |
37 | { | |
38 | running = false; | |
39 | exit(0); | |
40 | } | |
41 | ||
42 | static void usage(const char *prog) | |
43 | { | |
44 | fprintf(stderr, | |
45 | "%s: %s /sys/bus/hid/devices/0BUS:0VID:0PID:00ID\n\n", | |
46 | __func__, prog); | |
47 | fprintf(stderr, | |
48 | "This program will upload and attach a HID-BPF program to the given device.\n" | |
49 | "On the Etekcity Scroll 6E, the X and Y axis will be inverted, but on any other\n" | |
50 | "device, chances are high that the device will not be working anymore\n\n" | |
51 | "consider this as a demo and adapt the eBPF program to your needs\n" | |
52 | "Hit Ctrl-C to unbind the program and reset the device\n"); | |
53 | } | |
54 | ||
55 | static int get_hid_id(const char *path) | |
56 | { | |
57 | const char *str_id, *dir; | |
58 | char uevent[1024]; | |
59 | int fd; | |
60 | ||
61 | memset(uevent, 0, sizeof(uevent)); | |
62 | snprintf(uevent, sizeof(uevent) - 1, "%s/uevent", path); | |
63 | ||
64 | fd = open(uevent, O_RDONLY | O_NONBLOCK); | |
65 | if (fd < 0) | |
66 | return -ENOENT; | |
67 | ||
68 | close(fd); | |
69 | ||
70 | dir = basename((char *)path); | |
71 | ||
72 | str_id = dir + sizeof("0003:0001:0A37."); | |
73 | return (int)strtol(str_id, NULL, 16); | |
74 | } | |
75 | ||
76 | int main(int argc, char **argv) | |
77 | { | |
78 | struct hid_mouse *skel; | |
79 | struct bpf_program *prog; | |
80 | int err; | |
81 | const char *optstr = ""; | |
82 | const char *sysfs_path; | |
83 | int opt, hid_id, attach_fd; | |
84 | struct attach_prog_args args = { | |
85 | .retval = -1, | |
86 | }; | |
87 | DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr, | |
88 | .ctx_in = &args, | |
89 | .ctx_size_in = sizeof(args), | |
90 | ); | |
91 | ||
92 | while ((opt = getopt(argc, argv, optstr)) != -1) { | |
93 | switch (opt) { | |
94 | default: | |
95 | usage(basename(argv[0])); | |
96 | return 1; | |
97 | } | |
98 | } | |
99 | ||
100 | if (optind == argc) { | |
101 | usage(basename(argv[0])); | |
102 | return 1; | |
103 | } | |
104 | ||
105 | sysfs_path = argv[optind]; | |
106 | if (!sysfs_path) { | |
107 | perror("sysfs"); | |
108 | return 1; | |
109 | } | |
110 | ||
111 | skel = hid_mouse__open_and_load(); | |
112 | if (!skel) { | |
113 | fprintf(stderr, "%s %s:%d", __func__, __FILE__, __LINE__); | |
114 | return -1; | |
115 | } | |
116 | ||
117 | hid_id = get_hid_id(sysfs_path); | |
118 | ||
119 | if (hid_id < 0) { | |
120 | fprintf(stderr, "can not open HID device: %m\n"); | |
121 | return 1; | |
122 | } | |
123 | args.hid = hid_id; | |
124 | ||
125 | attach_fd = bpf_program__fd(skel->progs.attach_prog); | |
126 | if (attach_fd < 0) { | |
127 | fprintf(stderr, "can't locate attach prog: %m\n"); | |
128 | return 1; | |
129 | } | |
130 | ||
131 | bpf_object__for_each_program(prog, *skel->skeleton->obj) { | |
132 | /* ignore syscalls */ | |
133 | if (bpf_program__get_type(prog) != BPF_PROG_TYPE_TRACING) | |
134 | continue; | |
135 | ||
136 | args.retval = -1; | |
137 | args.prog_fd = bpf_program__fd(prog); | |
138 | err = bpf_prog_test_run_opts(attach_fd, &tattr); | |
139 | if (err) { | |
140 | fprintf(stderr, "can't attach prog to hid device %d: %m (err: %d)\n", | |
141 | hid_id, err); | |
142 | return 1; | |
143 | } | |
144 | } | |
145 | ||
146 | signal(SIGINT, int_exit); | |
147 | signal(SIGTERM, int_exit); | |
148 | ||
149 | while (running) | |
150 | sleep(1); | |
151 | ||
152 | hid_mouse__destroy(skel); | |
153 | ||
154 | return 0; | |
155 | } |