https://gerrit.fd.io/r/c/vpp/+/30791
On Sat, Jan 16, 2021 at 3:22 AM Florin Coras <fcoras.li...@gmail.com> wrote: > Hi Ivan, > > You’re right that the assert wrongly assumes the connection must’ve been > established. I’m guessing you’re only sporadically hitting it because > typically the peer should not retransmit the syn after our reset (but > probably the packet is lost). Want to push a patch to remove it or should > I do it? > > Regards, > Florin > > On Jan 15, 2021, at 3:57 PM, Ivan Shvedunov <ivan...@gmail.com> wrote: > > Hi, > in our UPG project[1] I'm sometimes hitting the following assertion in > tcp[46]-syn-sent when trying to use at least 1 worker thread: > > https://github.com/FDio/vpp/blob/35ef865678d82b5a6fd3936716de8afb2fd49e60/src/vnet/tcp/tcp_input.c#L1820-L1821 > We're using the host stack in a rather non-standard way, so chances are > that this assertion is valid, but so far I didn't manage to understand why. > Problem is that half-open connection cleanup may happen after an > unsuccessful connect notify callback: > > https://github.com/FDio/vpp/blob/35ef865678d82b5a6fd3936716de8afb2fd49e60/src/vnet/tcp/tcp_input.c#L1955-L1962 > > https://github.com/FDio/vpp/blob/35ef865678d82b5a6fd3936716de8afb2fd49e60/src/vnet/tcp/tcp_input.c#L1978-L1986 > which leads us here: > > https://github.com/FDio/vpp/blob/35ef865678d82b5a6fd3936716de8afb2fd49e60/src/vnet/tcp/tcp_input.c#L2016-L2021 > In this case, if the half-open connection belongs to another thread (and > it usually belongs to the main thread), the actual cleanup is delayed > and TCP_CONN_HALF_OPEN_DONE flag is set for the connection, but, due to the > notify call failure, the connection establishment is not completed so the > assertion mentioned above can't be satisfied. > Am I missing a reason why the buffer should actually never reach > tcp[46]-syn-sent node after the corresponding half-open connection is > undergoing this delayed cleanup, so perhaps UPG TCP proxy code needs to be > corrected there, or is this ASSERT indeed invalid? > > [1] https://github.com/travelping/upg-vpp > > > > -- Ivan Shvedunov <ivan...@gmail.com> ;; My GPG fingerprint is: 2E61 0748 8E12 BB1A 5AB9 F7D0 613E C0F8 0BC5 2807
-=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#18523): https://lists.fd.io/g/vpp-dev/message/18523 Mute This Topic: https://lists.fd.io/mt/79717445/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
