Re: [PATCH net-next] net: tracepoint: adding new tracepoint arguments in inet_sock_set_state

[Yafang Shao]

On Fri, Jan 5, 2018 at 3:21 PM, Song Liu <songliubraving@xxxxxx> wrote:
>
>> On Jan 4, 2018, at 10:42 PM, Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>>
>> sk->sk_protocol and sk->sk_family are exposed as tracepoint arguments.
>> Then we can conveniently use these two arguments to do the filter.
>>
>> Suggested-by: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
>> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
>> ---
>> include/trace/events/sock.h | 24 ++++++++++++++++++------
>> net/ipv4/af_inet.c          |  6 ++++--
>> 2 files changed, 22 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h
>> index 3537c5f..c7df70f 100644
>> --- a/include/trace/events/sock.h
>> +++ b/include/trace/events/sock.h
>> @@ -11,7 +11,11 @@
>> #include <linux/ipv6.h>
>> #include <linux/tcp.h>
>>
>> -/* The protocol traced by sock_set_state */
>> +#define family_names                 \
>> +             EM(AF_INET)                             \
>> +             EMe(AF_INET6)
>> +
>> +/* The protocol traced by inet_sock_set_state */
>> #define inet_protocol_names           \
>>               EM(IPPROTO_TCP)                 \
>>               EM(IPPROTO_DCCP)                \
>> @@ -37,6 +41,7 @@
>> #define EM(a)       TRACE_DEFINE_ENUM(a);
>> #define EMe(a)      TRACE_DEFINE_ENUM(a);
>>
>> +family_names
>> inet_protocol_names
>> tcp_state_names
>>
>> @@ -45,6 +50,9 @@
>> #define EM(a)       { a, #a },
>> #define EMe(a)      { a, #a }
>>
>> +#define show_family_name(val)        \
>> +     __print_symbolic(val, family_names)
>> +
>> #define show_inet_protocol_name(val)    \
>>       __print_symbolic(val, inet_protocol_names)
>>
>> @@ -108,9 +116,10 @@
>>
>> TRACE_EVENT(inet_sock_set_state,
>>
>> -     TP_PROTO(const struct sock *sk, const int oldstate, const int newstate),
>> +     TP_PROTO(const struct sock *sk, const int family, const int protocol,
>> +                             const int oldstate, const int newstate),
>
> Are there cases we need protocol and/or family that is different to
> sk->sk_protocol/sk_family? If not, I think we don't need to change the
> TP_PROTO.
>
> Thanks,
> Song
>

As of now, there're two sk_family, which are AF_INET and AF_INET6, and
three sk_protocol which are  IPPROTO_TCP, IPPROTO_SCTP and
IPPROTO_DCCP.

Thanks
Yafang

>>
>> -     TP_ARGS(sk, oldstate, newstate),
>> +     TP_ARGS(sk, family, protocol, oldstate, newstate),
>>
>>       TP_STRUCT__entry(
>>               __field(const void *, skaddr)
>> @@ -118,6 +127,7 @@
>>               __field(int, newstate)
>>               __field(__u16, sport)
>>               __field(__u16, dport)
>> +             __field(__u16, family)
>>               __field(__u8, protocol)
>>               __array(__u8, saddr, 4)
>>               __array(__u8, daddr, 4)
>> @@ -133,8 +143,9 @@
>>               __entry->skaddr = sk;
>>               __entry->oldstate = oldstate;
>>               __entry->newstate = newstate;
>> +             __entry->family = family;
>> +             __entry->protocol = protocol;
>>
>> -             __entry->protocol = sk->sk_protocol;
>>               __entry->sport = ntohs(inet->inet_sport);
>>               __entry->dport = ntohs(inet->inet_dport);
>>
>> @@ -145,7 +156,7 @@
>>               *p32 =  inet->inet_daddr;
>>
>> #if IS_ENABLED(CONFIG_IPV6)
>> -             if (sk->sk_family == AF_INET6) {
>> +             if (family == AF_INET6) {
>>                       pin6 = (struct in6_addr *)__entry->saddr_v6;
>>                       *pin6 = sk->sk_v6_rcv_saddr;
>>                       pin6 = (struct in6_addr *)__entry->daddr_v6;
>> @@ -160,7 +171,8 @@
>>               }
>>       ),
>>
>> -     TP_printk("protocol=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
>> +     TP_printk("family=%s protocol=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
>> +                     show_family_name(__entry->family),
>>                       show_inet_protocol_name(__entry->protocol),
>>                       __entry->sport, __entry->dport,
>>                       __entry->saddr, __entry->daddr,
>> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
>> index bab98a4..1d52796 100644
>> --- a/net/ipv4/af_inet.c
>> +++ b/net/ipv4/af_inet.c
>> @@ -1223,14 +1223,16 @@ int inet_sk_rebuild_header(struct sock *sk)
>>
>> void inet_sk_set_state(struct sock *sk, int state)
>> {
>> -     trace_inet_sock_set_state(sk, sk->sk_state, state);
>> +     trace_inet_sock_set_state(sk, sk->sk_family, sk->sk_protocol,
>> +                                                     sk->sk_state, state);
>>       sk->sk_state = state;
>> }
>> EXPORT_SYMBOL(inet_sk_set_state);
>>
>> void inet_sk_state_store(struct sock *sk, int newstate)
>> {
>> -     trace_inet_sock_set_state(sk, sk->sk_state, newstate);
>> +     trace_inet_sock_set_state(sk, sk->sk_family, sk->sk_protocol,
>> +                                                     sk->sk_state, newstate);
>>       smp_store_release(&sk->sk_state, newstate);
>> }
>>
>> --
>> 1.8.3.1
>>
>