media: rc: introduce BPF_PROG_LIRC_MODE2

Add support for BPF_PROG_LIRC_MODE2. This type of BPF program can call
rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report
that the last key should be repeated.

The bpf program can be attached to using the bpf(BPF_PROG_ATTACH) syscall;
the target_fd must be the /dev/lircN device.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 24e9fbb80e81..da7013a12a58 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/device.h>
+#include <linux/file.h>
 #include <linux/idr.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
@@ -104,6 +105,12 @@ void ir_lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev)
 			TO_US(ev.duration), TO_STR(ev.pulse));
 	}
 
+	/*
+	 * bpf does not care about the gap generated above; that exists
+	 * for backwards compatibility
+	 */
+	lirc_bpf_run(dev, sample);
+
 	spin_lock_irqsave(&dev->lirc_fh_lock, flags);
 	list_for_each_entry(fh, &dev->lirc_fh, list) {
 		if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports)
@@ -816,4 +823,27 @@ void __exit lirc_dev_exit(void)
 	unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX);
 }
 
+struct rc_dev *rc_dev_get_from_fd(int fd)
+{
+	struct fd f = fdget(fd);
+	struct lirc_fh *fh;
+	struct rc_dev *dev;
+
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+
+	if (f.file->f_op != &lirc_fops) {
+		fdput(f);
+		return ERR_PTR(-EINVAL);
+	}
+
+	fh = f.file->private_data;
+	dev = fh->rc;
+
+	get_device(&dev->dev);
+	fdput(f);
+
+	return dev;
+}
+
 MODULE_ALIAS("lirc_dev");