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Make TCP_INFO report TFO
AbandonedPublic

Authored by trasz on Sep 29 2019, 5:51 PM.

Details

Reviewers
None
Group Reviewers
transport
Summary

Make tcp(4) report TFO by setting TCPI_OPT_TFO in tcpi_options
TCP_INFO field.

Diff Detail

Repository
rS FreeBSD src repository - subversion
Lint
Lint OK
Unit
No Unit Test Coverage
Build Status
Buildable 26766
Build 25110: arc lint + arc unit

Event Timeline

TCP_INFO is not portable afaik; however, I wonder why the linux varian has a flag for "SYN_DATA" (which may get delivered to the appliacation if the TFO is present), but no flag for TFO, while this change is signaling the presence of TFO, but no SYN_DATA... Just curious...

In D21840#477432, @rscheff_gmx.at wrote:

TCP_INFO is not portable afaik; however, I wonder why the linux varian has a flag for "SYN_DATA" (which may get delivered to the appliacation if the TFO is present), but no flag for TFO, while this change is signaling the presence of TFO, but no SYN_DATA... Just curious...

I highly suspect that is because the source of the code does not yet use TFO, but is preparing for the future. ;-)

What you suggest seems like a logical addition. But, it can be a separate change.

FWIW, this is a change separated from a larger diff, so it might eg be incomplete. I've posted it here to have an easy link to point people to. I'll mark it as "Changes planned" to not give a false impression.