freebsd adding further TCP stack related constants.

[devnexen]

ref: freebsd/freebsd-src@e570d23#diff-c354fa9fe15a3e5c90079f38792a8e5458d76677437a53ee7537a62fbc72e100R255

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[tgross35]

We probably only need one of these. It looks like TCP_BBR_USE_RACK_RR was added more recently freebsd/freebsd-src@e570d23#diff-c354fa9fe15a3e5c90079f38792a8e5458d76677437a53ee7537a62fbc72e100R255.

[tgross35]

ref: https://man.freebsd.org/cgi/man.cgi?query=tcp

Looks like this is the wrong link, these aren't mentioned there. https://github.com/freebsd/freebsd-src/blob/main/sys/netinet/tcp.h is the header file.

One nit but the rest looks fine to me. @asomers could you double check this?

[asomers]

The definitions look correct to me, but they're awfully obscure. These constants are so obscure that there's a risk of them being deemed unstable private APIs. That's why I generally don't like to add such things to libc unless there's a real need.

For example, constants added in 9ab890d later had to be deprecated in ab57796 . Do you have an actual need for these constants, or are you just adding them for completeness's sake?

[devnexen]

The definitions look correct to me, but they're awfully obscure. These constants are so obscure that there's a risk of them being deemed unstable private APIs. That's why I generally don't like to add such things to libc unless there's a real need.

For example, constants added in 9ab890d later had to be deprecated in ab57796 . Do you have an actual need for these constants, or are you just adding them for completeness's sake?

I m mostly interested by BBR constants even tough not all values have necessarily an immediate usefulness and a little bit of completeness yes.

[tgross35]

@devnexen maybe based on the above, you could drop everything except the BBR constants, and perhaps maybe only the more popular ones? (I have no idea which those would be). Since we have some BBR constants already, and that's your usecase

[tgross35]

Thank you!