diff options
| author |   Florin Coras <fcoras@cisco.com> | 2019-08-29 18:33:24 -0700 |
|---|---|---|
| committer |   Andrew Yourtchenko <ayourtch@gmail.com> | 2019-09-28 20:15:44 +0000 |
| commit | a2c0637129f0c642a4d55df297bb353243ca7a49 (patch) | |
| tree | c25e6d57c479dbd5b6230a503f308e245a438333 | |
| parent | 6cf2fde9bb1dda74f8dcc2d96a17d6875cc1c9db (diff) | |
tcp: track zero rwnd errors
Type: feature
Distinguish between rcv window errors and errors after we advertised a
zero rcv window, i.e., potential window probes.
Change-Id: I6cb453c7aaae456c0a05a8328cfaa55eaca10bf7
Signed-off-by: Florin Coras <fcoras@cisco.com>
(cherry picked from commit a495a3ea146a8484dac9f6b594fb2b044437c7a4)
| -rw-r--r-- | src/vnet/tcp/tcp_error.def | 3 | ||||
| -rwxr-xr-x | src/vnet/tcp/tcp_input.c | 7 |
2 files changed, 9 insertions, 1 deletions
diff --git a/src/vnet/tcp/tcp_error.def b/src/vnet/tcp/tcp_error.def index 7dbe952e104..5acc576e3cb 100644 --- a/src/vnet/tcp/tcp_error.def +++ b/src/vnet/tcp/tcp_error.def @@ -48,4 +48,5 @@ tcp_error (OPTIONS, "Could not parse options") tcp_error (PAWS, "PAWS check failed") tcp_error (RCV_WND, "Segment not in receive window") tcp_error (FIN_RCVD, "FINs received") -tcp_error (LINK_LOCAL_RW, "No rewrite for link local connection")
\ No newline at end of file +tcp_error (LINK_LOCAL_RW, "No rewrite for link local connection") +tcp_error (ZERO_RWND, "Zero receive window")
\ No newline at end of file diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c index 0b1ac73209b..45a40a276b0 100755 --- a/src/vnet/tcp/tcp_input.c +++ b/src/vnet/tcp/tcp_input.c @@ -365,6 +365,13 @@ tcp_segment_validate (tcp_worker_ctx_t * wrk, tcp_connection_t * tc0, *error0 = TCP_ERROR_RCV_WND; + /* If we advertised a zero rcv_wnd and the segment is in the past or the + * next one that we expect, it is probably a window probe */ + if ((tc0->flags & TCP_CONN_ZERO_RWND_SENT) + && seq_lt (vnet_buffer (b0)->tcp.seq_end, + tc0->rcv_las + tc0->rcv_opts.mss)) + *error0 = TCP_ERROR_ZERO_RWND; + tc0->errors.below_data_wnd += seq_lt (vnet_buffer (b0)->tcp.seq_end, tc0->rcv_las); |