how to access cmsg, udp and IP headers from go?

[Dave Taht]

is there a sane library or go library extension for getting to the cmsg information on a udp socket from go? In our case (bufferbloat.net) we are trying to get the "irtt" tool capable of seeing the SO_TIMESTAMP_NS information from the linux kernel on receipt of it's udp packets from across the Internet so as to better measure one way delay (OWD). 

Just filed a bug and a fuller description here:

https://github.com/golang/go/issues/46831

some info on cmsg:

https://www.man7.org/linux/man-pages/man3/cmsg.3.html

some info on irtt:

https://github.com/heistp/irtt

[Ian Lance Taylor]

I think you are looking for
https://pkg.go.dev/syscall#ParseSocketControlMessage. It may help to
look at the test code in https://golang.org/src/syscall/creds_test.go.

Ian