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authorYousuk Seung <ysseung@google.com>2020-07-31 01:44:40 +0300
committerDavid S. Miller <davem@davemloft.net>2020-08-01 03:00:44 +0300
commit48040793fa6003d211f021c6ad273477bcd90d91 (patch)
tree7a37d2d4390b9aa54bc87465b94ab358b4dedfcd /net/ipv4
parentc6886957d2d959d5217994cd08d59c816fc23e70 (diff)
downloadlinux-48040793fa6003d211f021c6ad273477bcd90d91.tar.xz
tcp: add earliest departure time to SCM_TIMESTAMPING_OPT_STATS
This change adds TCP_NLA_EDT to SCM_TIMESTAMPING_OPT_STATS that reports the earliest departure time(EDT) of the timestamped skb. By tracking EDT values of the skb from different timestamps, we can observe when and how much the value changed. This allows to measure the precise delay injected on the sender host e.g. by a bpf-base throttler. Signed-off-by: Yousuk Seung <ysseung@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4afec552f211..c06d2bfd2ec4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3501,10 +3501,12 @@ static size_t tcp_opt_stats_get_size(void)
nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */
nla_total_size(sizeof(u16)) + /* TCP_NLA_TIMEOUT_REHASH */
nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */
+ nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */
0;
}
-struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
+struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
+ const struct sk_buff *orig_skb)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *stats;
@@ -3558,6 +3560,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash);
nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT,
max_t(int, 0, tp->write_seq - tp->snd_nxt));
+ nla_put_u64_64bit(stats, TCP_NLA_EDT, orig_skb->skb_mstamp_ns,
+ TCP_NLA_PAD);
return stats;
}