diff options
| author | Mike Maloney <maloney@google.com> | 2017-08-22 17:08:48 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-23 20:30:47 -0700 |
| commit | 98aaa913b4ed250324429f0a9e6d5f77a3b5276c (patch) | |
| tree | 651cb3f820b76e3b199d25c4997dd0e494cdcc06 /include | |
| parent | b28547728d4fd42a004df2b662724e16ff778db6 (diff) | |
| download | linux-98aaa913b4ed250324429f0a9e6d5f77a3b5276c.tar.bz2 | |
tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg
When SOF_TIMESTAMPING_RX_SOFTWARE is enabled for tcp sockets, return the
timestamp corresponding to the highest sequence number data returned.
Previously the skb->tstamp is overwritten when a TCP packet is placed
in the out of order queue. While the packet is in the ooo queue, save the
timestamp in the TCB_SKB_CB. This space is shared with the gso_*
options which are only used on the tx path, and a previously unused 4
byte hole.
When skbs are coalesced either in the sk_receive_queue or the
out_of_order_queue always choose the timestamp of the appended skb to
maintain the invariant of returning the timestamp of the last byte in
the recvmsg buffer.
Signed-off-by: Mike Maloney <maloney@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index a995004ae946..c614ff135b66 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -774,6 +774,12 @@ struct tcp_skb_cb { u16 tcp_gso_segs; u16 tcp_gso_size; }; + + /* Used to stash the receive timestamp while this skb is in the + * out of order queue, as skb->tstamp is overwritten by the + * rbnode. + */ + ktime_t swtstamp; }; __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ @@ -790,7 +796,8 @@ struct tcp_skb_cb { __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ eor:1, /* Is skb MSG_EOR marked? */ - unused:6; + has_rxtstamp:1, /* SKB has a RX timestamp */ + unused:5; __u32 ack_seq; /* Sequence number ACK'd */ union { struct { |