diff options
| author | Willem de Bruijn <willemb@google.com> | 2019-08-27 15:09:33 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-08-28 15:56:28 -0700 |
| commit | 888a5c53c0d8be6e98bc85b677f179f77a647873 (patch) | |
| tree | d882b9205799014bac650960277f88a76147f400 /net/ipv4/tcp_output.c | |
| parent | dbf47a2a094edf58983265e323ca4bdcdb58b5ee (diff) | |
| download | lwn-888a5c53c0d8be6e98bc85b677f179f77a647873.tar.gz lwn-888a5c53c0d8be6e98bc85b677f179f77a647873.zip | |
tcp: inherit timestamp on mtu probe
TCP associates tx timestamp requests with a byte in the bytestream.
If merging skbs in tcp_mtu_probe, migrate the tstamp request.
Similar to MSG_EOR, do not allow moving a timestamp from any segment
in the probe but the last. This to avoid merging multiple timestamps.
Tested with the packetdrill script at
https://github.com/wdebruij/packetdrill/commits/mtu_probe-1
Link: http://patchwork.ozlabs.org/patch/1143278/#2232897
Fixes: 4ed2d765dfac ("net-timestamp: TCP timestamping")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 979520e46e33..8a645f304e6c 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2053,7 +2053,7 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len) if (len <= skb->len) break; - if (unlikely(TCP_SKB_CB(skb)->eor)) + if (unlikely(TCP_SKB_CB(skb)->eor) || tcp_has_tx_tstamp(skb)) return false; len -= skb->len; @@ -2170,6 +2170,7 @@ static int tcp_mtu_probe(struct sock *sk) * we need to propagate it to the new skb. */ TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor; + tcp_skb_collapse_tstamp(nskb, skb); tcp_unlink_write_queue(skb, sk); sk_wmem_free_skb(sk, skb); } else { |