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Subject[PATCH v3 1/2] media: rc: introduce BPF_PROG_RAWIR_EVENT
Date
Add support for BPF_PROG_RAWIR_EVENT. 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.

Signed-off-by: Sean Young <sean@mess.org>
---
drivers/media/rc/Kconfig | 13 ++
drivers/media/rc/Makefile | 1 +
drivers/media/rc/bpf-rawir-event.c | 363 +++++++++++++++++++++++++++++
drivers/media/rc/lirc_dev.c | 24 ++
drivers/media/rc/rc-core-priv.h | 24 ++
drivers/media/rc/rc-ir-raw.c | 14 +-
include/linux/bpf_rcdev.h | 30 +++
include/linux/bpf_types.h | 3 +
include/uapi/linux/bpf.h | 55 ++++-
kernel/bpf/syscall.c | 7 +
10 files changed, 531 insertions(+), 3 deletions(-)
create mode 100644 drivers/media/rc/bpf-rawir-event.c
create mode 100644 include/linux/bpf_rcdev.h

diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index eb2c3b6eca7f..2172d65b0213 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -25,6 +25,19 @@ config LIRC
passes raw IR to and from userspace, which is needed for
IR transmitting (aka "blasting") and for the lirc daemon.

+config BPF_RAWIR_EVENT
+ bool "Support for eBPF programs attached to lirc devices"
+ depends on BPF_SYSCALL
+ depends on RC_CORE=y
+ depends on LIRC
+ help
+ Allow attaching eBPF programs to a lirc device using the bpf(2)
+ syscall command BPF_PROG_ATTACH. This is supported for raw IR
+ receivers.
+
+ These eBPF programs can be used to decode IR into scancodes, for
+ IR protocols not supported by the kernel decoders.
+
menuconfig RC_DECODERS
bool "Remote controller decoders"
depends on RC_CORE
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 2e1c87066f6c..74907823bef8 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -5,6 +5,7 @@ obj-y += keymaps/
obj-$(CONFIG_RC_CORE) += rc-core.o
rc-core-y := rc-main.o rc-ir-raw.o
rc-core-$(CONFIG_LIRC) += lirc_dev.o
+rc-core-$(CONFIG_BPF_RAWIR_EVENT) += bpf-rawir-event.o
obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o
obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o
diff --git a/drivers/media/rc/bpf-rawir-event.c b/drivers/media/rc/bpf-rawir-event.c
new file mode 100644
index 000000000000..7cb48b8d87b5
--- /dev/null
+++ b/drivers/media/rc/bpf-rawir-event.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+// bpf-rawir-event.c - handles bpf
+//
+// Copyright (C) 2018 Sean Young <sean@mess.org>
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/bpf_rcdev.h>
+#include "rc-core-priv.h"
+
+/*
+ * BPF interface for raw IR
+ */
+const struct bpf_prog_ops rawir_event_prog_ops = {
+};
+
+BPF_CALL_1(bpf_rc_repeat, struct bpf_rawir_event*, event)
+{
+ struct ir_raw_event_ctrl *ctrl;
+
+ ctrl = container_of(event, struct ir_raw_event_ctrl, bpf_rawir_event);
+
+ rc_repeat(ctrl->dev);
+
+ return 0;
+}
+
+static const struct bpf_func_proto rc_repeat_proto = {
+ .func = bpf_rc_repeat,
+ .gpl_only = true, /* rc_repeat is EXPORT_SYMBOL_GPL */
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+};
+
+BPF_CALL_4(bpf_rc_keydown, struct bpf_rawir_event*, event, u32, protocol,
+ u32, scancode, u32, toggle)
+{
+ struct ir_raw_event_ctrl *ctrl;
+
+ ctrl = container_of(event, struct ir_raw_event_ctrl, bpf_rawir_event);
+
+ rc_keydown(ctrl->dev, protocol, scancode, toggle != 0);
+
+ return 0;
+}
+
+static const struct bpf_func_proto rc_keydown_proto = {
+ .func = bpf_rc_keydown,
+ .gpl_only = true, /* rc_keydown is EXPORT_SYMBOL_GPL */
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_ANYTHING,
+};
+
+static const struct bpf_func_proto *
+rawir_event_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_rc_repeat:
+ return &rc_repeat_proto;
+ case BPF_FUNC_rc_keydown:
+ return &rc_keydown_proto;
+ case BPF_FUNC_map_lookup_elem:
+ return &bpf_map_lookup_elem_proto;
+ case BPF_FUNC_map_update_elem:
+ return &bpf_map_update_elem_proto;
+ case BPF_FUNC_map_delete_elem:
+ return &bpf_map_delete_elem_proto;
+ case BPF_FUNC_ktime_get_ns:
+ return &bpf_ktime_get_ns_proto;
+ case BPF_FUNC_tail_call:
+ return &bpf_tail_call_proto;
+ case BPF_FUNC_get_prandom_u32:
+ return &bpf_get_prandom_u32_proto;
+ case BPF_FUNC_trace_printk:
+ if (capable(CAP_SYS_ADMIN))
+ return bpf_get_trace_printk_proto();
+ /* fall through */
+ default:
+ return NULL;
+ }
+}
+
+static bool rawir_event_is_valid_access(int off, int size,
+ enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ /* struct bpf_rawir_event has two u32 fields */
+ if (type == BPF_WRITE)
+ return false;
+
+ if (size != sizeof(__u32))
+ return false;
+
+ if (!(off == offsetof(struct bpf_rawir_event, duration) ||
+ off == offsetof(struct bpf_rawir_event, type)))
+ return false;
+
+ return true;
+}
+
+const struct bpf_verifier_ops rawir_event_verifier_ops = {
+ .get_func_proto = rawir_event_func_proto,
+ .is_valid_access = rawir_event_is_valid_access
+};
+
+#define BPF_MAX_PROGS 64
+
+static int rc_dev_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog)
+{
+ struct ir_raw_event_ctrl *raw;
+ struct bpf_prog_list *pl;
+ int ret, size;
+
+ if (rcdev->driver_type != RC_DRIVER_IR_RAW)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&ir_raw_handler_lock);
+ if (ret)
+ return ret;
+
+ raw = rcdev->raw;
+ if (!raw) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ size = 0;
+ list_for_each_entry(pl, &raw->progs, node) {
+ if (pl->prog == prog) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ size++;
+ }
+
+ if (size >= BPF_MAX_PROGS) {
+ ret = -E2BIG;
+ goto out;
+ }
+
+ pl = kmalloc(sizeof(*pl), GFP_KERNEL);
+ if (!pl) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ pl->prog = prog;
+ list_add(&pl->node, &raw->progs);
+out:
+ mutex_unlock(&ir_raw_handler_lock);
+ return ret;
+}
+
+static int rc_dev_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog)
+{
+ struct ir_raw_event_ctrl *raw;
+ struct bpf_prog_list *pl, *tmp;
+ int ret;
+
+ if (rcdev->driver_type != RC_DRIVER_IR_RAW)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&ir_raw_handler_lock);
+ if (ret)
+ return ret;
+
+ raw = rcdev->raw;
+ if (!raw) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ ret = -ENOENT;
+
+ list_for_each_entry_safe(pl, tmp, &raw->progs, node) {
+ if (pl->prog == prog) {
+ list_del(&pl->node);
+ kfree(pl);
+ bpf_prog_put(prog);
+ ret = 0;
+ goto out;
+ }
+ }
+out:
+ mutex_unlock(&ir_raw_handler_lock);
+ return ret;
+}
+
+void rc_dev_bpf_init(struct rc_dev *rcdev)
+{
+ INIT_LIST_HEAD(&rcdev->raw->progs);
+}
+
+void rc_dev_bpf_run(struct rc_dev *rcdev, struct ir_raw_event ev)
+{
+ struct ir_raw_event_ctrl *raw = rcdev->raw;
+ struct bpf_prog_list *pl;
+
+ if (list_empty(&raw->progs))
+ return;
+
+ if (unlikely(ev.carrier_report)) {
+ raw->bpf_rawir_event.carrier = ev.carrier;
+ raw->bpf_rawir_event.type = BPF_RAWIR_EVENT_CARRIER;
+ } else {
+ raw->bpf_rawir_event.duration = ev.duration;
+
+ if (ev.pulse)
+ raw->bpf_rawir_event.type = BPF_RAWIR_EVENT_PULSE;
+ else if (ev.timeout)
+ raw->bpf_rawir_event.type = BPF_RAWIR_EVENT_TIMEOUT;
+ else if (ev.reset)
+ raw->bpf_rawir_event.type = BPF_RAWIR_EVENT_RESET;
+ else
+ raw->bpf_rawir_event.type = BPF_RAWIR_EVENT_SPACE;
+ }
+
+ list_for_each_entry(pl, &raw->progs, node)
+ BPF_PROG_RUN(pl->prog, &raw->bpf_rawir_event);
+}
+
+void rc_dev_bpf_free(struct rc_dev *rcdev)
+{
+ struct bpf_prog_list *pl, *tmp;
+
+ list_for_each_entry_safe(pl, tmp, &rcdev->raw->progs, node) {
+ list_del(&pl->node);
+ bpf_prog_put(pl->prog);
+ kfree(pl);
+ }
+}
+
+int rc_dev_prog_attach(const union bpf_attr *attr)
+{
+ struct bpf_prog *prog;
+ struct rc_dev *rcdev;
+ int ret;
+
+ if (attr->attach_flags)
+ return -EINVAL;
+
+ prog = bpf_prog_get_type(attr->attach_bpf_fd,
+ BPF_PROG_TYPE_RAWIR_EVENT);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ rcdev = rc_dev_get_from_fd(attr->target_fd);
+ if (IS_ERR(rcdev)) {
+ bpf_prog_put(prog);
+ return PTR_ERR(rcdev);
+ }
+
+ ret = rc_dev_bpf_attach(rcdev, prog);
+ if (ret)
+ bpf_prog_put(prog);
+
+ put_device(&rcdev->dev);
+
+ return ret;
+}
+
+int rc_dev_prog_detach(const union bpf_attr *attr)
+{
+ struct bpf_prog *prog;
+ struct rc_dev *rcdev;
+ int ret;
+
+ if (attr->attach_flags)
+ return -EINVAL;
+
+ prog = bpf_prog_get_type(attr->attach_bpf_fd,
+ BPF_PROG_TYPE_RAWIR_EVENT);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ rcdev = rc_dev_get_from_fd(attr->target_fd);
+ if (IS_ERR(rcdev)) {
+ bpf_prog_put(prog);
+ return PTR_ERR(rcdev);
+ }
+
+ ret = rc_dev_bpf_detach(rcdev, prog);
+
+ bpf_prog_put(prog);
+ put_device(&rcdev->dev);
+
+ return ret;
+}
+
+int rc_dev_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
+{
+ __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
+ struct ir_raw_event_ctrl *raw;
+ struct bpf_prog_list *pl;
+ struct rc_dev *rcdev;
+ u32 cnt, flags = 0, *ids, i;
+ int ret;
+
+ if (attr->query.query_flags)
+ return -EINVAL;
+
+ rcdev = rc_dev_get_from_fd(attr->query.target_fd);
+ if (IS_ERR(rcdev))
+ return PTR_ERR(rcdev);
+
+ if (rcdev->driver_type != RC_DRIVER_IR_RAW) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = mutex_lock_interruptible(&ir_raw_handler_lock);
+ if (ret)
+ goto out;
+
+ raw = rcdev->raw;
+ if (!raw) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ cnt = 0;
+ list_for_each_entry(pl, &raw->progs, node)
+ cnt++;
+
+ if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (attr->query.prog_cnt != 0 && prog_ids && cnt) {
+ if (attr->query.prog_cnt < cnt)
+ cnt = attr->query.prog_cnt;
+
+ ids = kmalloc_array(cnt, sizeof(u32), GFP_KERNEL);
+ if (!ids) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ i = 0;
+ list_for_each_entry(pl, &raw->progs, node) {
+ ids[i++] = pl->prog->aux->id;
+ if (i == cnt)
+ break;
+ }
+
+ ret = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
+ }
+out:
+ mutex_unlock(&ir_raw_handler_lock);
+ put_device(&rcdev->dev);
+
+ return ret;
+}
diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 24e9fbb80e81..193540ded626 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>
@@ -816,4 +817,27 @@ 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");
diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
index e0e6a17460f6..148db73cfa0c 100644
--- a/drivers/media/rc/rc-core-priv.h
+++ b/drivers/media/rc/rc-core-priv.h
@@ -13,6 +13,7 @@
#define MAX_IR_EVENT_SIZE 512

#include <linux/slab.h>
+#include <uapi/linux/bpf.h>
#include <media/rc-core.h>

/**
@@ -57,6 +58,11 @@ struct ir_raw_event_ctrl {
/* raw decoder state follows */
struct ir_raw_event prev_ev;
struct ir_raw_event this_ev;
+
+#ifdef CONFIG_BPF_RAWIR_EVENT
+ struct bpf_rawir_event bpf_rawir_event;
+ struct list_head progs;
+#endif
struct nec_dec {
int state;
unsigned count;
@@ -126,6 +132,9 @@ struct ir_raw_event_ctrl {
} imon;
};

+/* Mutex for locking raw IR processing and handler change */
+extern struct mutex ir_raw_handler_lock;
+
/* macros for IR decoders */
static inline bool geq_margin(unsigned d1, unsigned d2, unsigned margin)
{
@@ -288,6 +297,7 @@ void ir_lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev);
void ir_lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc);
int ir_lirc_register(struct rc_dev *dev);
void ir_lirc_unregister(struct rc_dev *dev);
+struct rc_dev *rc_dev_get_from_fd(int fd);
#else
static inline int lirc_dev_init(void) { return 0; }
static inline void lirc_dev_exit(void) {}
@@ -299,4 +309,18 @@ static inline int ir_lirc_register(struct rc_dev *dev) { return 0; }
static inline void ir_lirc_unregister(struct rc_dev *dev) { }
#endif

+/*
+ * bpf interface
+ */
+#ifdef CONFIG_BPF_RAWIR_EVENT
+void rc_dev_bpf_init(struct rc_dev *dev);
+void rc_dev_bpf_free(struct rc_dev *dev);
+void rc_dev_bpf_run(struct rc_dev *dev, struct ir_raw_event ev);
+#else
+static inline void rc_dev_bpf_init(struct rc_dev *dev) { }
+static inline void rc_dev_bpf_free(struct rc_dev *dev) { }
+static inline void rc_dev_bpf_run(struct rc_dev *dev, struct ir_raw_event ev)
+{ }
+#endif
+
#endif /* _RC_CORE_PRIV */
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index 374f83105a23..e68cdd4fbf5d 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -14,7 +14,7 @@
static LIST_HEAD(ir_raw_client_list);

/* Used to handle IR raw handler extensions */
-static DEFINE_MUTEX(ir_raw_handler_lock);
+DEFINE_MUTEX(ir_raw_handler_lock);
static LIST_HEAD(ir_raw_handler_list);
static atomic64_t available_protocols = ATOMIC64_INIT(0);

@@ -32,6 +32,7 @@ static int ir_raw_event_thread(void *data)
handler->protocols || !handler->protocols)
handler->decode(raw->dev, ev);
ir_lirc_raw_event(raw->dev, ev);
+ rc_dev_bpf_run(raw->dev, ev);
raw->prev_ev = ev;
}
mutex_unlock(&ir_raw_handler_lock);
@@ -572,6 +573,7 @@ int ir_raw_event_prepare(struct rc_dev *dev)
spin_lock_init(&dev->raw->edge_spinlock);
timer_setup(&dev->raw->edge_handle, ir_raw_edge_handle, 0);
INIT_KFIFO(dev->raw->kfifo);
+ rc_dev_bpf_init(dev);

return 0;
}
@@ -621,9 +623,17 @@ void ir_raw_event_unregister(struct rc_dev *dev)
list_for_each_entry(handler, &ir_raw_handler_list, list)
if (handler->raw_unregister)
handler->raw_unregister(dev);
- mutex_unlock(&ir_raw_handler_lock);
+
+ rc_dev_bpf_free(dev);

ir_raw_event_free(dev);
+
+ /*
+ * A user can be calling bpf(BPF_PROG_{QUERY|ATTACH|DETACH}), so
+ * ensure that the raw member is null on unlock; this is how
+ * "device gone" is checked.
+ */
+ mutex_unlock(&ir_raw_handler_lock);
}

/*
diff --git a/include/linux/bpf_rcdev.h b/include/linux/bpf_rcdev.h
new file mode 100644
index 000000000000..17a30f30436a
--- /dev/null
+++ b/include/linux/bpf_rcdev.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BPF_RCDEV_H
+#define _BPF_RCDEV_H
+
+#include <linux/bpf.h>
+#include <uapi/linux/bpf.h>
+
+#ifdef CONFIG_BPF_RAWIR_EVENT
+int rc_dev_prog_attach(const union bpf_attr *attr);
+int rc_dev_prog_detach(const union bpf_attr *attr);
+int rc_dev_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr);
+#else
+static inline int rc_dev_prog_attach(const union bpf_attr *attr)
+{
+ return -EINVAL;
+}
+
+static inline int rc_dev_prog_detach(const union bpf_attr *attr)
+{
+ return -EINVAL;
+}
+
+static inline int rc_dev_prog_query(const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ return -EINVAL;
+}
+#endif
+
+#endif /* _BPF_RCDEV_H */
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index b67f8793de0d..e2b1b12474d4 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -25,6 +25,9 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint)
#ifdef CONFIG_CGROUP_BPF
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev)
#endif
+#ifdef CONFIG_BPF_RAWIR_EVENT
+BPF_PROG_TYPE(BPF_PROG_TYPE_RAWIR_EVENT, rawir_event)
+#endif

BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d94d333a8225..243e141e8a5b 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -141,6 +141,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_SK_MSG,
BPF_PROG_TYPE_RAW_TRACEPOINT,
BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_PROG_TYPE_RAWIR_EVENT,
};

enum bpf_attach_type {
@@ -158,6 +159,7 @@ enum bpf_attach_type {
BPF_CGROUP_INET6_CONNECT,
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
+ BPF_RAWIR_EVENT,
__MAX_BPF_ATTACH_TYPE
};

@@ -1902,6 +1904,35 @@ union bpf_attr {
* egress otherwise). This is the only flag supported for now.
* Return
* **SK_PASS** on success, or **SK_DROP** on error.
+ *
+ * int bpf_rc_keydown(void *ctx, u32 protocol, u32 scancode, u32 toggle)
+ * Description
+ * Report decoded scancode with toggle value. For use in
+ * BPF_PROG_TYPE_RAWIR_EVENT, to report a successfully
+ * decoded scancode. This is will generate a keydown event,
+ * and a keyup event once the scancode is no longer repeated.
+ *
+ * *ctx* pointer to bpf_rawir_event, *protocol* is decoded
+ * protocol (see RC_PROTO_* enum).
+ *
+ * Some protocols include a toggle bit, in case the button
+ * was released and pressed again between consecutive scancodes,
+ * copy this bit into *toggle* if it exists, else set to 0.
+ *
+ * Return
+ * Always return 0 (for now)
+ *
+ * int bpf_rc_repeat(void *ctx)
+ * Description
+ * Repeat the last decoded scancode; some IR protocols like
+ * NEC have a special IR message for repeat last button,
+ * in case user is holding a button down; the scancode is
+ * not repeated.
+ *
+ * *ctx* pointer to bpf_rawir_event.
+ *
+ * Return
+ * Always return 0 (for now)
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -1976,7 +2007,9 @@ union bpf_attr {
FN(fib_lookup), \
FN(sock_hash_update), \
FN(msg_redirect_hash), \
- FN(sk_redirect_hash),
+ FN(sk_redirect_hash), \
+ FN(rc_repeat), \
+ FN(rc_keydown),

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -2043,6 +2076,26 @@ enum bpf_hdr_start_off {
BPF_HDR_START_NET,
};

+/*
+ * user accessible mirror of in-kernel ir_raw_event
+ */
+#define BPF_RAWIR_EVENT_SPACE 0
+#define BPF_RAWIR_EVENT_PULSE 1
+#define BPF_RAWIR_EVENT_TIMEOUT 2
+#define BPF_RAWIR_EVENT_RESET 3
+#define BPF_RAWIR_EVENT_CARRIER 4
+#define BPF_RAWIR_EVENT_DUTY_CYCLE 5
+
+struct bpf_rawir_event {
+ union {
+ __u32 duration;
+ __u32 carrier;
+ __u32 duty_cycle;
+ };
+
+ __u32 type;
+};
+
/* user accessible mirror of in-kernel sk_buff.
* new fields can only be added to the end of this structure
*/
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e2aeb5e89f44..75c089f407c8 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -11,6 +11,7 @@
*/
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
+#include <linux/bpf_rcdev.h>
#include <linux/btf.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
@@ -1567,6 +1568,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, true);
+ case BPF_RAWIR_EVENT:
+ return rc_dev_prog_attach(attr);
default:
return -EINVAL;
}
@@ -1637,6 +1640,8 @@ static int bpf_prog_detach(const union bpf_attr *attr)
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, false);
+ case BPF_RAWIR_EVENT:
+ return rc_dev_prog_detach(attr);
default:
return -EINVAL;
}
@@ -1684,6 +1689,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
break;
+ case BPF_RAWIR_EVENT:
+ return rc_dev_prog_query(attr, uattr);
default:
return -EINVAL;
}
--
2.17.0
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