diff options
| author | Stefano Brivio <sbrivio@redhat.com> | 2025-10-02 00:52:53 +0200 |
|---|---|---|
| committer | Stefano Brivio <sbrivio@redhat.com> | 2025-10-07 22:22:39 +0200 |
| commit | a94783951d0d759912dcae0c6289c61fe6a86fc4 (patch) | |
| tree | f3edfaaeba90201786d8cde1bb81c65138c56c44 /test/lib | |
| parent | b145441913eef6f8885b6b84531e944ff593790c (diff) | |
| download | passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar.gz passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar.bz2 passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar.lz passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar.xz passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.tar.zst passt-a94783951d0d759912dcae0c6289c61fe6a86fc4.zip | |
tcp: On partial send (incomplete sendmsg()), request a retransmission right away
...possibly with an updated window value. As we're discarding the
remaining data, we'll need to receive it again. If we don't request
a retransmission immediately, we'll see an apparent gap in the
sequence, and request a retransmission on the next data batch or
segment, but we're just wasting time like that. In packets:
28686 0.000007 88.198.0.164 → 93.235.151.95 16118 TCP 55414 → 47080 [ACK] Seq=80501 Ack=141 Win=65536 Len=16064 [TCP segment of a reassembled PDU]
28687 0.000012 88.198.0.164 → 93.235.151.95 16118 TCP [TCP Window Full] 55414 → 47080 [ACK] Seq=96565 Ack=141 Win=65536 Len=16064 [TCP segment of a reassembled PDU]
on this second data segment, we have a short sendmsg(), and
28688 0.000026 93.235.151.95 → 88.198.0.164 54 TCP 47080 → 55414 [ACK] Seq=141 Ack=90721 Win=32128 Len=0
consequently acknowledge it, without requesting a retransmission,
28689 0.000006 88.198.0.164 → 93.235.151.95 8866 HTTP HTTP/1.1 200 ok (text/css)
so the server proceeds sending a bit more, but
28690 0.000016 93.235.151.95 → 88.198.0.164 54 TCP [TCP Dup ACK 28688#1] 47080 → 55414 [ACK] Seq=141 Ack=90721 Win=32128 Len=0
28691 0.000000 93.235.151.95 → 88.198.0.164 54 TCP [TCP Dup ACK 28688#2] 47080 → 55414 [ACK] Seq=141 Ack=90721 Win=32128 Len=0
we'll throw that data (from frame #28689) away, and finally request
a retransmission as we spotted the gap now.
Request a retransmission as soon as we know we'll need it, instead.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'test/lib')
0 files changed, 0 insertions, 0 deletions