transportprotocols:03november2022

Attendees

  • glebius@
  • olivier@
  • rrs@
  • rscheff@
  • tuexen@

Ongoing Short Term Projects

  • What is the status of D16851? thj@ works on it and you are waiting for feedback from bz@.
  • rscheff@ is improving AccECN code: D36303.
  • tuexen@ wants to discuss the behaviour of recv(fd, NULL, 0, 0) for SOCK_DGRAM sockets. tuexen@ will bring this up on the net@ mailing list.
  • It was discussed whether the TCP_LOG socket option should be inherited from the listener. jtl@ said that this should be the case, but interaction with the sysctl-variable net.inet.tcp.bb.log_auto_ratio should be taken into account. tuexen@ will look at it and add jtl@ as a reviewer.
  • netstat does not support reading connection information from a core file anymore. tuexen@ will document that in the man-page.

Ongoing Longer Term Projects

  • D37061glebius@ works on simplifying INP_DROPPED.
  • D23230 is implementing ECN++.
  • D28822 improves PRR, needs some cleanup.
  • glebius@ wants feedback on D35199. bz@ isn't fine with it…
  • tuexen@ wants to write a tool which dumps the BBLog information of a TCP endpoint from a life system or a core. Using kvm_read() has drawbacks as glebius@ pointed out, using a python kgdb script may be an alternative. An alternative is to write a python kgdb script which pumps data into tcplog_dumper. This would allow to minimize code duplication.
  • rscheff@ will add some ECN stat counter to the TCP_INFO option. glebius@ will contact re@ about the handling of adding/using padding fields. D37016
  • glebius@ wants to remove INP_DROPPED. This will allow using socket options on sockets in TIMEWAIT and CLOSED state. In particular, this will allow using tcpsso on these socket options.
  • jtl@ suggested to reduce the MSL value used to control the TIMEWAIT state. It was discussed to use a maximum RTT instead. tuexen@ will add the tracking of the maximum RTT and make this algorithm used when the sysctl-variable net.inet.tcp.msl is set to zero. In a separate the default of the sysctl-variable net.inet.tcp.msl will be changed to zero. tuexen@ will also reach out to the TCPM working group to see what other implementations do.
  • glebius@ wants to question trpt(8) utility. It was agreed that tuexen@ makes sure the BBLog provides at least the information provided by trpt(8) and glebius starts a discussion on current@ to remove trpt(8) and its kernel counterpart. In addition to this, TCP_PCAP will be removed.
  • glebius@: merging tcpcb+inpcb, using standard KPI to stop TCP timers, reverting 9c3507f91987b7c8ce3b895a5ee46a1de6bc42f2 aka https://reviews.freebsd.org/D36399. A panic with TOE.

Next Meeting

17 November 2022 @ 1500 UTC

  • transportprotocols/03november2022.txt
  • Last modified: 2022/11/03 16:15
  • by MichaelTuexen