The kernel IR decoders support the most widely used IR protocols, but there
are many protocols which are not supported[1]. For example, the
lirc-remotes[2] repo has over 2700 remotes, many of which are not supported
by rc-core. There is a "long tail" of unsupported IR protocols.
IR encoding is done in such a way that some simple circuit can decode it;
therefore, bpf is ideal.
In order to support all these protocols, here we have bpf based IR decoding.
The idea is that user-space can define a decoder in bpf, attach it to
the rc device through the lirc chardev.
Separate work is underway to extend ir-keytable to have an extensive library
of bpf-based decoders, and a much expanded library of rc keymaps.
Another future application would be to compile IRP[3] to a IR BPF program, and
so support virtually every remote without having to write a decoder for each.
Thanks,
Sean Young
[1] http://www.hifi-remote.com/wiki/index.php?title=DecodeIR
[2] https://sourceforge.net/p/lirc-remotes/code/ci/master/tree/remotes/
[3] http://www.hifi-remote.com/wiki/index.php?title=IRP_Notation
Changes since v1:
- Code review comments from Y Song <[email protected]> and
Randy Dunlap <[email protected]>
- Re-wrote sample bpf to be selftest
- Renamed RAWIR_DECODER -> RAWIR_EVENT (Kconfig, context, bpf prog type)
- Rebase on bpf-next
- Introduced bpf_rawir_event context structure with simpler access checking
Sean Young (2):
media: rc: introduce BPF_PROG_RAWIR_EVENT
bpf: add selftest for rawir_event type program
drivers/media/rc/Kconfig | 10 +
drivers/media/rc/Makefile | 1 +
drivers/media/rc/bpf-rawir-event.c | 322 ++++++++++++++++++
drivers/media/rc/lirc_dev.c | 28 ++
drivers/media/rc/rc-core-priv.h | 19 ++
drivers/media/rc/rc-ir-raw.c | 3 +
include/linux/bpf_rcdev.h | 30 ++
include/linux/bpf_types.h | 3 +
include/uapi/linux/bpf.h | 55 ++-
kernel/bpf/syscall.c | 7 +
tools/bpf/bpftool/prog.c | 1 +
tools/include/uapi/linux/bpf.h | 55 ++-
tools/lib/bpf/libbpf.c | 1 +
tools/testing/selftests/bpf/Makefile | 7 +-
tools/testing/selftests/bpf/bpf_helpers.h | 6 +
tools/testing/selftests/bpf/test_rawir.sh | 37 ++
.../selftests/bpf/test_rawir_event_kern.c | 26 ++
.../selftests/bpf/test_rawir_event_user.c | 90 +++++
18 files changed, 696 insertions(+), 5 deletions(-)
create mode 100644 drivers/media/rc/bpf-rawir-event.c
create mode 100644 include/linux/bpf_rcdev.h
create mode 100755 tools/testing/selftests/bpf/test_rawir.sh
create mode 100644 tools/testing/selftests/bpf/test_rawir_event_kern.c
create mode 100644 tools/testing/selftests/bpf/test_rawir_event_user.c
--
2.17.0
This is simple test over rc-loopback.
Signed-off-by: Sean Young <[email protected]>
---
tools/bpf/bpftool/prog.c | 1 +
tools/include/uapi/linux/bpf.h | 55 +++++++++++-
tools/lib/bpf/libbpf.c | 1 +
tools/testing/selftests/bpf/Makefile | 7 +-
tools/testing/selftests/bpf/bpf_helpers.h | 6 ++
tools/testing/selftests/bpf/test_rawir.sh | 37 ++++++++
.../selftests/bpf/test_rawir_event_kern.c | 26 ++++++
.../selftests/bpf/test_rawir_event_user.c | 90 +++++++++++++++++++
8 files changed, 219 insertions(+), 4 deletions(-)
create mode 100755 tools/testing/selftests/bpf/test_rawir.sh
create mode 100644 tools/testing/selftests/bpf/test_rawir_event_kern.c
create mode 100644 tools/testing/selftests/bpf/test_rawir_event_user.c
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 9bdfdf2d3fbe..8889a4ee8577 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -71,6 +71,7 @@ static const char * const prog_type_name[] = {
[BPF_PROG_TYPE_SK_MSG] = "sk_msg",
[BPF_PROG_TYPE_RAW_TRACEPOINT] = "raw_tracepoint",
[BPF_PROG_TYPE_CGROUP_SOCK_ADDR] = "cgroup_sock_addr",
+ [BPF_PROG_TYPE_RAWIR_EVENT] = "rawir_event",
};
static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 02e4112510f8..8ba1be825af0 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -140,6 +140,7 @@ 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 {
@@ -157,6 +158,7 @@ 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
};
@@ -1855,6 +1857,35 @@ union bpf_attr {
* Egress device index on success, 0 if packet needs to continue
* up the stack for further processing or a negative error in case
* of failure.
+ *
+ * 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), \
@@ -1926,7 +1957,9 @@ union bpf_attr {
FN(skb_get_xfrm_state), \
FN(get_stack), \
FN(skb_load_bytes_relative), \
- FN(fib_lookup),
+ FN(fib_lookup), \
+ FN(rc_repeat), \
+ FN(rc_keydown),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -1993,6 +2026,26 @@ 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/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index df54c4c9e48a..372269e9053d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1455,6 +1455,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+ case BPF_PROG_TYPE_RAWIR_EVENT:
return false;
case BPF_PROG_TYPE_UNSPEC:
case BPF_PROG_TYPE_KPROBE:
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 438d4f93875b..d4b7a410c333 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -24,7 +24,7 @@ urandom_read: urandom_read.c
# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
- test_sock test_btf test_sockmap
+ test_sock test_btf test_sockmap test_rawir_event_user
TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \
test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
@@ -33,7 +33,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \
- test_get_stack_rawtp.o
+ test_get_stack_rawtp.o test_rawir_event_kern.o
# Order correspond to 'make run_tests' order
TEST_PROGS := test_kmod.sh \
@@ -42,7 +42,8 @@ TEST_PROGS := test_kmod.sh \
test_xdp_meta.sh \
test_offload.py \
test_sock_addr.sh \
- test_tunnel.sh
+ test_tunnel.sh \
+ test_rawir.sh
# Compile but not part of 'make run_tests'
TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index 2375d06c706b..641af70048bd 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -106,6 +106,12 @@ static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) =
static int (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params,
int plen, __u32 flags) =
(void *) BPF_FUNC_fib_lookup;
+static int (*bpf_rc_repeat)(void *ctx) =
+ (void *) BPF_FUNC_rc_repeat;
+static int (*bpf_rc_keydown)(void *ctx, unsigned protocol, unsigned scancode,
+ unsigned toggle) =
+ (void *) BPF_FUNC_rc_keydown;
+
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
diff --git a/tools/testing/selftests/bpf/test_rawir.sh b/tools/testing/selftests/bpf/test_rawir.sh
new file mode 100755
index 000000000000..30529e829af1
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_rawir.sh
@@ -0,0 +1,37 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test bpf_rawir_event over rc-loopback. Steps for the test:
+#
+# 1. Find the /dev/lircN device for rc-loopback
+# 2. Attach bpf_rawir_event program which decodes some IR.
+# 3. Send some IR to the same IR device; since it is loopback, this will
+# end up in the bpf program
+# 4. bpf program should decode IR and report keycode
+# 5. We can read keycode from same /dev/lirc device
+
+GREEN='\033[0;92m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+modprobe rc-loopback
+
+for i in /sys/class/rc/rc*
+do
+ if grep -q DRV_NAME=rc-loopback $i/uevent
+ then
+ LIRCDEV=$(grep DEVNAME= $i/lirc*/uevent | sed sQDEVNAME=Q/dev/Q)
+ fi
+done
+
+if [ -n $LIRCDEV ];
+then
+ TYPE=rawir_event
+ ./test_rawir_event_user $LIRCDEV
+ ret=$?
+ if [ $ret -ne 0 ]; then
+ echo -e ${RED}"FAIL: $TYPE"${NC}
+ return 1
+ fi
+ echo -e ${GREEN}"PASS: $TYPE"${NC}
+fi
diff --git a/tools/testing/selftests/bpf/test_rawir_event_kern.c b/tools/testing/selftests/bpf/test_rawir_event_kern.c
new file mode 100644
index 000000000000..33ba5d30af62
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_rawir_event_kern.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+// test ir decoder
+//
+// Copyright (C) 2018 Sean Young <[email protected]>
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+SEC("rawir_event")
+int bpf_decoder(struct bpf_rawir_event *e)
+{
+ if (e->type == BPF_RAWIR_EVENT_PULSE) {
+ /*
+ * The lirc interface is microseconds, but here we receive
+ * nanoseconds.
+ */
+ int microseconds = e->duration / 1000;
+
+ if (microseconds & 0x10000)
+ bpf_rc_keydown(e, 0x40, microseconds & 0xffff, 0);
+ }
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_rawir_event_user.c b/tools/testing/selftests/bpf/test_rawir_event_user.c
new file mode 100644
index 000000000000..0d1f711b28f1
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_rawir_event_user.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+// test ir decoder
+//
+// Copyright (C) 2018 Sean Young <[email protected]>
+
+#include <linux/bpf.h>
+#include <linux/lirc.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <poll.h>
+#include <libgen.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "bpf_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+int main(int argc, char **argv)
+{
+ struct bpf_object *obj;
+ int ret, lircfd, progfd, mode;
+ int testir = 0x1dead;
+
+ if (argc != 2) {
+ printf("Usage: %s /dev/lircN\n", argv[0]);
+ return 2;
+ }
+
+ ret = bpf_prog_load("test_rawir_event_kern.o",
+ BPF_PROG_TYPE_RAWIR_EVENT, &obj, &progfd);
+ if (ret) {
+ printf("Failed to load bpf program\n");
+ return 1;
+ }
+
+ lircfd = open(argv[1], O_RDWR | O_NONBLOCK);
+ if (lircfd == -1) {
+ printf("failed to open lirc device %s: %m\n", argv[1]);
+ return 1;
+ }
+
+ mode = LIRC_MODE_SCANCODE;
+ if (ioctl(lircfd, LIRC_SET_REC_MODE, &mode)) {
+ printf("failed to set rec mode: %m\n");
+ return 1;
+ }
+
+ ret = bpf_prog_attach(progfd, lircfd, BPF_RAWIR_EVENT, 0);
+ if (ret) {
+ printf("Failed to attach bpf to lirc device: %m\n");
+ return 1;
+ }
+
+ /* Write raw IR */
+ ret = write(lircfd, &testir, sizeof(testir));
+ if (ret != sizeof(testir)) {
+ printf("Failed to send test IR message: %m\n");
+ return 1;
+ }
+
+ struct pollfd pfd = { .fd = lircfd, .events = POLLIN };
+
+ poll(&pfd, 1, 100);
+
+ struct lirc_scancode lsc;
+
+ /* Read decoded IR */
+ ret = read(lircfd, &lsc, sizeof(lsc));
+ if (ret != sizeof(lsc)) {
+ printf("Failed to read decoded IR: %m\n");
+ return 1;
+ }
+
+ if (lsc.scancode != 0xdead || lsc.rc_proto != 64) {
+ printf("Incorrect scancode decoded\n");
+ return 1;
+ }
+
+ return 0;
+}
--
2.17.0
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 <[email protected]>
---
drivers/media/rc/Kconfig | 10 +
drivers/media/rc/Makefile | 1 +
drivers/media/rc/bpf-rawir-event.c | 322 +++++++++++++++++++++++++++++
drivers/media/rc/lirc_dev.c | 28 +++
drivers/media/rc/rc-core-priv.h | 19 ++
drivers/media/rc/rc-ir-raw.c | 3 +
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, 477 insertions(+), 1 deletion(-)
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..55747af5b978 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -25,6 +25,16 @@ 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 "Enable attaching BPF programs to lirc devices"
+ depends on BPF_SYSCALL
+ depends on RC_CORE=y
+ depends on LIRC
+ help
+ Enable this option to make it possible to load custom IR
+ decoders written in BPF. These decoders are type
+ BPF_PROG_TYPE_RAW_IR_EVENT.
+
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..8007841977d6
--- /dev/null
+++ b/drivers/media/rc/bpf-rawir-event.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+// bpf-rawir-event.c - handles bpf
+//
+// Copyright (C) 2018 Sean Young <[email protected]>
+
+#include <linux/bpf.h>
+#include <linux/filter.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;
+ 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_array __rcu *old_array;
+ struct bpf_prog_array *new_array;
+ int ret, i, size;
+
+ if (rcdev->driver_type != RC_DRIVER_IR_RAW)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&rcdev->lock);
+ if (ret)
+ return ret;
+
+ raw = rcdev->raw;
+
+ if (raw->progs) {
+ size = bpf_prog_array_length(raw->progs);
+ for (i = 0; i < size; i++) {
+ if (prog == raw->progs->progs[i]) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
+
+ if (size >= BPF_MAX_PROGS) {
+ ret = -E2BIG;
+ goto out;
+ }
+ }
+
+ old_array = raw->progs;
+ ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
+ if (ret < 0)
+ goto out;
+
+ rcu_assign_pointer(raw->progs, new_array);
+ bpf_prog_array_free(old_array);
+out:
+ mutex_unlock(&rcdev->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_array __rcu *old_array;
+ struct bpf_prog_array *new_array;
+ int ret;
+
+ if (rcdev->driver_type != RC_DRIVER_IR_RAW)
+ return -EINVAL;
+
+ ret = mutex_lock_interruptible(&rcdev->lock);
+ if (ret)
+ return ret;
+
+ raw = rcdev->raw;
+
+ old_array = raw->progs;
+ ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array);
+ if (ret < 0) {
+ bpf_prog_array_delete_safe(old_array, prog);
+ } else {
+ rcu_assign_pointer(raw->progs, new_array);
+ bpf_prog_array_free(old_array);
+ }
+
+ bpf_prog_put(prog);
+ mutex_unlock(&rcdev->lock);
+ return 0;
+}
+
+void rc_dev_bpf_run(struct rc_dev *rcdev, struct ir_raw_event ev)
+{
+ struct ir_raw_event_ctrl *raw = rcdev->raw;
+
+ if (!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;
+ }
+
+ BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_rawir_event, BPF_PROG_RUN);
+}
+
+void rc_dev_bpf_put(struct rc_dev *rcdev)
+{
+ struct bpf_prog_array *progs = rcdev->raw->progs;
+ int i, size;
+
+ if (!progs)
+ return;
+
+ size = bpf_prog_array_length(progs);
+ for (i = 0; i < size; i++)
+ bpf_prog_put(progs->progs[i]);
+
+ bpf_prog_array_free(rcdev->raw->progs);
+}
+
+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 bpf_prog_array *progs;
+ struct rc_dev *rcdev;
+ u32 cnt, flags = 0;
+ 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(&rcdev->lock);
+ if (ret)
+ goto out;
+
+ progs = rcdev->raw->progs;
+ cnt = progs ? bpf_prog_array_length(progs) : 0;
+
+ 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)
+ ret = bpf_prog_array_copy_to_user(progs, prog_ids, cnt);
+
+out:
+ mutex_unlock(&rcdev->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..c3028d0366d1 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 +817,31 @@ 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 rc_dev *dev;
+ struct file *f;
+
+ f = fget_raw(fd);
+ if (!f)
+ return ERR_PTR(-EBADF);
+
+ if (!S_ISCHR(f->f_inode->i_mode) ||
+ imajor(f->f_inode) != MAJOR(lirc_base_dev)) {
+ fput(f);
+ return ERR_PTR(-EBADF);
+ }
+
+ dev = container_of(f->f_inode->i_cdev, struct rc_dev, lirc_cdev);
+ if (!dev->registered) {
+ fput(f);
+ return ERR_PTR(-ENODEV);
+ }
+
+ get_device(&dev->dev);
+ fput(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..6db579f425f1 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 bpf_prog_array *progs;
+#endif
struct nec_dec {
int state;
unsigned count;
@@ -288,6 +294,7 @@ 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 +306,16 @@ 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_put(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_put(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..25828f15faec 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -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);
@@ -623,6 +624,8 @@ void ir_raw_event_unregister(struct rc_dev *dev)
handler->raw_unregister(dev);
mutex_unlock(&ir_raw_handler_lock);
+ rc_dev_bpf_put(dev);
+
ir_raw_event_free(dev);
}
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 d7df1b323082..667d1d557090 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 02e4112510f8..8ba1be825af0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -140,6 +140,7 @@ 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 {
@@ -157,6 +158,7 @@ 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
};
@@ -1855,6 +1857,35 @@ union bpf_attr {
* Egress device index on success, 0 if packet needs to continue
* up the stack for further processing or a negative error in case
* of failure.
+ *
+ * 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), \
@@ -1926,7 +1957,9 @@ union bpf_attr {
FN(skb_get_xfrm_state), \
FN(get_stack), \
FN(skb_load_bytes_relative), \
- FN(fib_lookup),
+ FN(fib_lookup), \
+ FN(rc_repeat), \
+ FN(rc_keydown),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -1993,6 +2026,26 @@ 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
On Tue, May 15, 2018 at 07:50:19PM +0100, Sean Young wrote:
> 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.
The locking of the list of attached bpf programs is broken in various ways.
I'll have to rework this for v3.
Sean
>
> Signed-off-by: Sean Young <[email protected]>
> ---
> drivers/media/rc/Kconfig | 10 +
> drivers/media/rc/Makefile | 1 +
> drivers/media/rc/bpf-rawir-event.c | 322 +++++++++++++++++++++++++++++
> drivers/media/rc/lirc_dev.c | 28 +++
> drivers/media/rc/rc-core-priv.h | 19 ++
> drivers/media/rc/rc-ir-raw.c | 3 +
> 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, 477 insertions(+), 1 deletion(-)
> 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..55747af5b978 100644
> --- a/drivers/media/rc/Kconfig
> +++ b/drivers/media/rc/Kconfig
> @@ -25,6 +25,16 @@ 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 "Enable attaching BPF programs to lirc devices"
> + depends on BPF_SYSCALL
> + depends on RC_CORE=y
> + depends on LIRC
> + help
> + Enable this option to make it possible to load custom IR
> + decoders written in BPF. These decoders are type
> + BPF_PROG_TYPE_RAW_IR_EVENT.
> +
> 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..8007841977d6
> --- /dev/null
> +++ b/drivers/media/rc/bpf-rawir-event.c
> @@ -0,0 +1,322 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// bpf-rawir-event.c - handles bpf
> +//
> +// Copyright (C) 2018 Sean Young <[email protected]>
> +
> +#include <linux/bpf.h>
> +#include <linux/filter.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;
> + 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_array __rcu *old_array;
> + struct bpf_prog_array *new_array;
> + int ret, i, size;
> +
> + if (rcdev->driver_type != RC_DRIVER_IR_RAW)
> + return -EINVAL;
> +
> + ret = mutex_lock_interruptible(&rcdev->lock);
> + if (ret)
> + return ret;
> +
> + raw = rcdev->raw;
> +
> + if (raw->progs) {
> + size = bpf_prog_array_length(raw->progs);
> + for (i = 0; i < size; i++) {
> + if (prog == raw->progs->progs[i]) {
> + ret = -EEXIST;
> + goto out;
> + }
> + }
> +
> + if (size >= BPF_MAX_PROGS) {
> + ret = -E2BIG;
> + goto out;
> + }
> + }
> +
> + old_array = raw->progs;
> + ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
> + if (ret < 0)
> + goto out;
> +
> + rcu_assign_pointer(raw->progs, new_array);
> + bpf_prog_array_free(old_array);
> +out:
> + mutex_unlock(&rcdev->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_array __rcu *old_array;
> + struct bpf_prog_array *new_array;
> + int ret;
> +
> + if (rcdev->driver_type != RC_DRIVER_IR_RAW)
> + return -EINVAL;
> +
> + ret = mutex_lock_interruptible(&rcdev->lock);
> + if (ret)
> + return ret;
> +
> + raw = rcdev->raw;
> +
> + old_array = raw->progs;
> + ret = bpf_prog_array_copy(old_array, prog, NULL, &new_array);
> + if (ret < 0) {
> + bpf_prog_array_delete_safe(old_array, prog);
> + } else {
> + rcu_assign_pointer(raw->progs, new_array);
> + bpf_prog_array_free(old_array);
> + }
> +
> + bpf_prog_put(prog);
> + mutex_unlock(&rcdev->lock);
> + return 0;
> +}
> +
> +void rc_dev_bpf_run(struct rc_dev *rcdev, struct ir_raw_event ev)
> +{
> + struct ir_raw_event_ctrl *raw = rcdev->raw;
> +
> + if (!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;
> + }
> +
> + BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_rawir_event, BPF_PROG_RUN);
> +}
> +
> +void rc_dev_bpf_put(struct rc_dev *rcdev)
> +{
> + struct bpf_prog_array *progs = rcdev->raw->progs;
> + int i, size;
> +
> + if (!progs)
> + return;
> +
> + size = bpf_prog_array_length(progs);
> + for (i = 0; i < size; i++)
> + bpf_prog_put(progs->progs[i]);
> +
> + bpf_prog_array_free(rcdev->raw->progs);
> +}
> +
> +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 bpf_prog_array *progs;
> + struct rc_dev *rcdev;
> + u32 cnt, flags = 0;
> + 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(&rcdev->lock);
> + if (ret)
> + goto out;
> +
> + progs = rcdev->raw->progs;
> + cnt = progs ? bpf_prog_array_length(progs) : 0;
> +
> + 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)
> + ret = bpf_prog_array_copy_to_user(progs, prog_ids, cnt);
> +
> +out:
> + mutex_unlock(&rcdev->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..c3028d0366d1 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 +817,31 @@ 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 rc_dev *dev;
> + struct file *f;
> +
> + f = fget_raw(fd);
> + if (!f)
> + return ERR_PTR(-EBADF);
> +
> + if (!S_ISCHR(f->f_inode->i_mode) ||
> + imajor(f->f_inode) != MAJOR(lirc_base_dev)) {
> + fput(f);
> + return ERR_PTR(-EBADF);
> + }
> +
> + dev = container_of(f->f_inode->i_cdev, struct rc_dev, lirc_cdev);
> + if (!dev->registered) {
> + fput(f);
> + return ERR_PTR(-ENODEV);
> + }
> +
> + get_device(&dev->dev);
> + fput(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..6db579f425f1 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 bpf_prog_array *progs;
> +#endif
> struct nec_dec {
> int state;
> unsigned count;
> @@ -288,6 +294,7 @@ 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 +306,16 @@ 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_put(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_put(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..25828f15faec 100644
> --- a/drivers/media/rc/rc-ir-raw.c
> +++ b/drivers/media/rc/rc-ir-raw.c
> @@ -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);
> @@ -623,6 +624,8 @@ void ir_raw_event_unregister(struct rc_dev *dev)
> handler->raw_unregister(dev);
> mutex_unlock(&ir_raw_handler_lock);
>
> + rc_dev_bpf_put(dev);
> +
> ir_raw_event_free(dev);
> }
>
> 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 d7df1b323082..667d1d557090 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 02e4112510f8..8ba1be825af0 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -140,6 +140,7 @@ 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 {
> @@ -157,6 +158,7 @@ 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
> };
>
> @@ -1855,6 +1857,35 @@ union bpf_attr {
> * Egress device index on success, 0 if packet needs to continue
> * up the stack for further processing or a negative error in case
> * of failure.
> + *
> + * 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), \
> @@ -1926,7 +1957,9 @@ union bpf_attr {
> FN(skb_get_xfrm_state), \
> FN(get_stack), \
> FN(skb_load_bytes_relative), \
> - FN(fib_lookup),
> + FN(fib_lookup), \
> + FN(rc_repeat), \
> + FN(rc_keydown),
>
> /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> * function eBPF program intends to call
> @@ -1993,6 +2026,26 @@ 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