spaceblog

Mail relay testing by Network Abuse Clearinghouse for testing that your mailservers are good citizens of the network. Especially useful when you’re performing some major configuration changes regarding relaying (i.e. converting a primary MX into a secondary) and you want to be sure that you didn’t just arse the config.

traceroute.org links to the traceroute CGIs for major ISPs in a lot of countries. What would be cooler is a script that scrapes the traceroutes from all of them to build a picture of how your subnet looks to the rest of the net.

So I’m mucking around with DejaGNU, trying to build a sensible test suite for filtergen (and by sensible, I don’t mean sensible, but instead “sufficiently different to that of GCC that the documentation and examples are really not helping”).

Basically, I can’t get my test program to be executed properly; stdout is some basic verification output to confirm that my scanner and parser are behaving correctly, whilst stderr captures all the warnings and errors – but the harness doesn’t like this: every time a message gets to stderr, the harness crashes. This seems to contradict the behaviour expected from reading /usr/share/dejagnu/dg.exp and this message, in which one expects to be able to test the warnings, errors, and output of a program.

So eventually, after pouring over gcc testsuite libraries, trying to work out how it all sticks together, I find myself in /usr/share/dejagnu/remote.exp, looking at local_exec, and I see this gem:

# Tcl's exec is a pile of crap. It does two very inappropriate things
# firstly, it has no business returning an error if the program being
# executed happens to write to stderr. Secondly, it appends its own
# error messages to the output of the command if the process exits with
# non-zero status.

EUREKA!

The rest of this function is comic gold; here’s another beautiful piece of prose (though certainly not the best nor the limit of entertainment one can find in this function).

# Uuuuuuugh. Now I'm getting really sick.
# If we didn't get an EOF, we have to kill the poor defenseless program.
# However, Tcl has no kill primitive, so we have to execute an external
# command in order to execute the execution. (English. Gotta love it.)

DNS Bajaj is a neat tool for checking the delegation of a domain; all admins should add it to their toolbox. (Mine is a bookmark menu full of looking glasses, Sam Spade and other useful remote query tools).

I just saw Walter Zorn’s JavaScript vector graphics library on NTK, this is killer-totally-sweet.

But I’m still trying to find a legitimate use for the insurmountable opportunity that is the block diagrams in CSS.

I’m thinking web UI for umbrella, perhaps network maps in JS vector graphics, and rack diagrams using the CSS technique.

Perhaps they can be bred to form an unholy breed of ubergraphics!