[PATCH v2 2/2] bpf: add selftest for rawir_event type program

From: Sean Young
Date: Tue May 15 2018 - 14:50:54 EST


This is simple test over rc-loopback.

Signed-off-by: Sean Young <sean@xxxxxxxx>
---
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 <sean@xxxxxxxx>
+
+#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 <sean@xxxxxxxx>
+
+#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