1 // SPDX-License-Identifier: GPL-2.0
4 // Copyright (C) 2018 Sean Young <sean@mess.org>
6 // A lirc chardev is a device representing a consumer IR (cir) device which
7 // can receive infrared signals from remote control and/or transmit IR.
9 // IR is sent as a series of pulses and space somewhat like morse code. The
10 // BPF program can decode this into scancodes so that rc-core can translate
11 // this into input key codes using the rc keymap.
13 // This test works by sending IR over rc-loopback, so the IR is processed by
14 // BPF and then decoded into scancodes. The lirc chardev must be the one
15 // associated with rc-loopback, see the output of ir-keytable(1).
17 // The following CONFIG options must be enabled for the test to succeed:
19 // CONFIG_BPF_RAWIR_EVENT=y
20 // CONFIG_RC_LOOPBACK=y
23 // 1. Open the /dev/lircN device for rc-loopback (given on command line)
24 // 2. Attach bpf_lirc_mode2 program which decodes some IR.
25 // 3. Send some IR to the same IR device; since it is loopback, this will
26 // end up in the bpf program
27 // 4. bpf program should decode IR and report keycode
28 // 5. We can read keycode from same /dev/lirc device
30 #include <linux/bpf.h>
31 #include <linux/lirc.h>
38 #include <sys/types.h>
39 #include <sys/ioctl.h>
45 #include <bpf/libbpf.h>
47 int main(int argc, char **argv)
49 struct bpf_object *obj;
50 int ret, lircfd, progfd, mode;
52 u32 prog_ids[10], prog_flags[10], prog_cnt;
55 printf("Usage: %s /dev/lircN\n", argv[0]);
59 ret = bpf_prog_load("test_lirc_mode2_kern.o",
60 BPF_PROG_TYPE_LIRC_MODE2, &obj, &progfd);
62 printf("Failed to load bpf program\n");
66 lircfd = open(argv[1], O_RDWR | O_NONBLOCK);
68 printf("failed to open lirc device %s: %m\n", argv[1]);
72 /* Let's try detach it before it was ever attached */
73 ret = bpf_prog_detach2(progfd, lircfd, BPF_LIRC_MODE2);
74 if (ret != -1 || errno != ENOENT) {
75 printf("bpf_prog_detach2 not attached should fail: %m\n");
79 mode = LIRC_MODE_SCANCODE;
80 if (ioctl(lircfd, LIRC_SET_REC_MODE, &mode)) {
81 printf("failed to set rec mode: %m\n");
86 ret = bpf_prog_query(lircfd, BPF_LIRC_MODE2, 0, prog_flags, prog_ids,
89 printf("Failed to query bpf programs on lirc device: %m\n");
94 printf("Expected nothing to be attached\n");
98 ret = bpf_prog_attach(progfd, lircfd, BPF_LIRC_MODE2, 0);
100 printf("Failed to attach bpf to lirc device: %m\n");
105 ret = write(lircfd, &testir, sizeof(testir));
106 if (ret != sizeof(testir)) {
107 printf("Failed to send test IR message: %m\n");
111 struct pollfd pfd = { .fd = lircfd, .events = POLLIN };
112 struct lirc_scancode lsc;
116 /* Read decoded IR */
117 ret = read(lircfd, &lsc, sizeof(lsc));
118 if (ret != sizeof(lsc)) {
119 printf("Failed to read decoded IR: %m\n");
123 if (lsc.scancode != 0xdead || lsc.rc_proto != 64) {
124 printf("Incorrect scancode decoded\n");
129 ret = bpf_prog_query(lircfd, BPF_LIRC_MODE2, 0, prog_flags, prog_ids,
132 printf("Failed to query bpf programs on lirc device: %m\n");
137 printf("Expected one program to be attached\n");
141 /* Let's try detaching it now it is actually attached */
142 ret = bpf_prog_detach2(progfd, lircfd, BPF_LIRC_MODE2);
144 printf("bpf_prog_detach2: returned %m\n");