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Date:   Thu, 17 May 2018 22:01:40 +0100
From:   Sean Young <sean@mess.org>
To:     Y Song <ys114321@gmail.com>
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Alexei Starovoitov <ast@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        netdev <netdev@vger.kernel.org>,
        Matthias Reichl <hias@horus.com>,
        Devin Heitmueller <dheitmueller@kernellabs.com>
Subject: Re: [PATCH v3 2/2] bpf: add selftest for rawir_event type program
Message-ID: <20180517210140.ck225yuckq6onheb@gofer.mess.org>
References: <cover.1526504511.git.sean@mess.org>
 <78945f2bf82e9f16695f72bed3930d1302d38e29.1526504511.git.sean@mess.org>
 <CAH3MdRUhrBzHXKgcu1htSHTqeKVWnci+ADrTriCqjXLHUezB+w@mail.gmail.com>
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On Thu, May 17, 2018 at 10:17:59AM -0700, Y Song wrote:
> On Wed, May 16, 2018 at 2:04 PM, Sean Young <sean@mess.org> wrote:
> > This is simple test over rc-loopback.
> >
> > Signed-off-by: Sean Young <sean@mess.org>
> > ---
> >  tools/bpf/bpftool/prog.c                      |   1 +
> >  tools/include/uapi/linux/bpf.h                |  57 +++++++-
> >  tools/lib/bpf/libbpf.c                        |   1 +
> >  tools/testing/selftests/bpf/Makefile          |   8 +-
> >  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     | 130 ++++++++++++++++++
> >  8 files changed, 261 insertions(+), 5 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
> 
> Could you copy include/uapi/linux/lirc.h file to tools directory as well.
> Otherwise, I will get the following compilation error:
> 
> gcc -Wall -O2 -I../../../include/uapi -I../../../lib
> -I../../../lib/bpf -I../../../../include/generated  -I../../../include
>    test_rawir_event_user.c
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/libbpf.a -lcap
> -lelf -lrt -lpthread -o
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/test_rawir_event_user
> test_rawir_event_user.c: In function ‘main’:
> test_rawir_event_user.c:60:15: error: ‘LIRC_MODE_SCANCODE’ undeclared
> (first use in this function); did you mean ‘LIRC_MODE_LIRCCODE’?
>         mode = LIRC_MODE_SCANCODE;
>                ^~~~~~~~~~~~~~~~~~
>                LIRC_MODE_LIRCCODE
> test_rawir_event_user.c:60:15: note: each undeclared identifier is
> reported only once for each function it appears in
> test_rawir_event_user.c:93:29: error: storage size of ‘lsc’ isn’t known
>         struct lirc_scancode lsc;
>                              ^~~
> test_rawir_event_user.c:93:29: warning: unused variable ‘lsc’
> [-Wunused-variable]

Ah, good catch. Thanks for testing this.
> 
> >
> > 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 1205d86a7a29..243e141e8a5b 100644
> > --- a/tools/include/uapi/linux/bpf.h
> > +++ b/tools/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
> >  };
> >
> > @@ -1829,7 +1831,6 @@ union bpf_attr {
> >   *     Return
> >   *             0 on success, or a negative error in case of failure.
> >   *
> > - *
> >   * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
> >   *     Description
> >   *             Do FIB lookup in kernel tables using parameters in *params*.
> > @@ -1856,6 +1857,7 @@ 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_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
> >   *     Description
> >   *             Add an entry to, or update a sockhash *map* referencing sockets.
> > @@ -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/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 1eb0fa2aba92..b84e36d05d34 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 +33,8 @@ 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_sockmap_kern.o test_sockhash_kern.o
> > +       test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \
> > +       test_rawir_event_kern.o
> >
> >  # Order correspond to 'make run_tests' order
> >  TEST_PROGS := test_kmod.sh \
> > @@ -42,7 +43,8 @@ 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 8f143dfb3700..26d89b7f9841 100644
> > --- a/tools/testing/selftests/bpf/bpf_helpers.h
> > +++ b/tools/testing/selftests/bpf/bpf_helpers.h
> > @@ -114,6 +114,12 @@ 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 int protocol,
> > +                            unsigned int scancode, unsigned int 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..0aa77b043ee1
> > --- /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}
> > +       else
> > +               echo -e ${GREEN}"PASS: $TYPE"${NC}
> > +       fi
> > +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@mess.org>
> > +
> > +#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..c3d7f2c68033
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/test_rawir_event_user.c
> > @@ -0,0 +1,130 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// test ir decoder
> > +//
> > +// Copyright (C) 2018 Sean Young <sean@mess.org>
> > +
> > +#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;
> > +       u32 prog_ids[10], prog_flags[10], prog_cnt;
> > +
> > +       if (argc != 2) {
> > +               printf("Usage: %s /dev/lircN\n", argv[0]);
> 
> Most people probably not really familiar with lircN device. It would be
> good to provide more information about how to enable this, e.g.,
>   CONFIG_RC_CORE=y
>   CONFIG_BPF_RAWIR_EVENT=y
>   CONFIG_RC_LOOPBACK=y
>   ......

Good point. I'll add some words explaining what is and how to make it work.

Thanks
Sean