Oct 30

Hieratic documentation

Here’e where I attempt to revive and popularize a fine old word in a new context.

hieratic, adj. Of or concerning priests; priestly. Often used of the ancient Egyptian writing system of abridged hieroglyphics used by priests.

Earlier today I was criticizing the waf build system in email. I wanted to say that its documentation exhibits a common flaw, which is that it reads not much like an explanation but as a memory aid for people who are already initiates of its inner mysteries. But this was not the main thrust of my argument; I wanted to observe it as an aside.

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Oct 23

NTPsec is not quite a full rewrite

In the wake of the Ars Technica article on NTP vulnerabilities, and Slashdot coverage, there has been sharply increased public interest in the work NTPsec is doing.

A lot of people have gotten the idea that I’m engaged in a full rewrite of the code, however, and that’s not accurate. What’s actually going on is more like a really massive cleanup and hardening effort. To give you some idea how massive, I report that the codebase is now down to about 43% of the size we inherited – in absolute numbers, down from 227KLOC to 97KLOC.

Details, possibly interesting, follow. But this is more than a summary of work; I’m going to use it to talk about good software-engineering practice by example.

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Oct 15

SPDX: boosting the signal

High on my list of Things That Annoy Me When I Hack is sourcefiles that contain huge blobs of license text at the top. That is valuable territory which should be occupied by a header comment explaining the code, not a boatload of boilerplate that I’ve seen hundreds of times before.

Hackers have a lot of superstitious ideas about IP law and one is that these blobs are necessary for the license to be binding. They are not: incorporation by reference is a familiar concept to lawyers and courts, it suffices to unambiguously name the license you want to apply rather than quoting it in full.

This is what I do in my code. But to make the practice really comfortable for lawyers we need a registry of standardized license identifiers and an unambiguous way of specifying that we intend to include by reference.

Comes now the Software Package Data Exchange to solve this problem once and for all. It’s a great idea, I endorse it, and I will be using it in all my software projects from now on.

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Oct 09

I improved time last night

Sometimes you find performance improvements in the simplest places. Last night I improved the time-stepping precision of NTP by a factor of up to a thousand. With a change of less than 20 lines.

The reason I was able to do this is because the NTP code had not caught up to a change in the precision of modern computer clocks. When it was written, you set time with settimeofday(2), which takes a structure containing seconds and microseconds. But modern POSIX-conformant Unixes have a clock_settime(2) which takes a structure containing seconds and nanoseconds.

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Oct 07

The FCC must not lock down device firmware!

The following is a comment I just filed on FCC Docket 15-170, “Amendment of Parts 0, 1, 2, 15, and 18 of the Commission’s Rules et al.”

Thirty years ago I had a small hand in the design of the Internet. Since then I’ve become a senior member of the informal collegium that maintains key pieces of it. You rely on my code every time you use a browser or a smartphone or an ATM. If you ever ride in a driverless car, the nav system will critically depend on code I wrote, and Google Maps already does. Today I’m deeply involved in fixing Internet time service.

I write to endorse the filings by Dave Taht and Bruce Perens (I gave Dave Taht a bit of editorial help). I’m submitting an independent comment because while I agree with the general thrust of their recommendations I think they may not go far enough.

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Oct 06

Vox is wrong – we don’t have too many guns, we have too many criminals

One of my followers on G+ asked me to comment on a Vox article,
What no politician wants to admit about gun control

I’ve studied the evidence, and I don’t believe the effect of the Australian confiscation on homicides was significant.  You can play games with statistics to make it look that way, but they are games.

As for the major contention of the article, it’s simply wrong.  80% of U.S. crime, including gun violence, is associated with the drug trade and happens in urban areas where civil order has partially or totally collapsed.

Outside those areas, the U.S. looks like Switzerland or Norway – lots of guns, very little crime.  Those huge, peaceful swathes of high-gun-ownership areas show that our problem is not too many guns, it’s too many criminals.

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