I have a need to be able to validate TOS/DSCP marks on response data from a set of HTTP servers. Would it be possible, given a list of target URLs to test, if there is a way in go
to generate the HTTP request, and then be able to examine the response's TCP packet details in order to obtain the TOS value?
My assumption at this point is that it may require creating a socket, and then dynamically generating a TCP packet that contains the HTTP request payload. I've been searching around to see if there were any libraries that would aid in this task, but haven't found anything specific yet.
Note: a simple TCP connection will not provide enough data - the target servers in question will alter TOS/DSCP marks dynamically based on the HTTP server name (so essentially, a single physical server will respond with different TOS marks depending on the vHost requested), so it is important to be able to verify the TOS on actual HTTP response packets, and not something simple like a ping. The TOS values in the TCP 3-way handshake cannot be trusted either - it must be a packet containing the HTTP data.