Showing your kids the Star Wars films - which order?

WARNING: Spoilers for the Star Wars movies. Here's some old-school spoiler space...










We finally finished (in fits and starts) showing our twin 8-year-olds all six Star Wars films. We showed them in the order Wendy and I saw them on the big screen: 4 (Star Wars), 5 (The Empire Strikes Back, 6 (Return of the Jedi), 1 (The Phantom Menace), 2 (Attack of the Clones), and finally 3 (Revenge of the Sith). Now I'll admit we skipped over char-broiled Anakin and Vader's suit-fitting during Sith, but they're 8, what would you expect?

As we finished up, something occurred to me. I remember reading my favorite online-exclusive film critic (and fellow parent) Drew McWeeney mentioning toward the bottom of this article that he was going to show them to his son in a slightly different order: 4, 5, 1, 2, 3, 6.

That's a fascinating way to show them. At the end of The Empire Strikes Back the first-time viewer may have a question about whether or not Darth Vader is Luke's father. Why not, at that point, show the first-time viewer the story of Anakin Skywalker? This works especially well now, where the special-edition Empire uses Ian McDiarmid's Emperor Palpatine, and an astute child will notice how much Darth Sidious resembles him (or even Senator Palpatine).

Commenters (oh gotta love Internet feedback... makes me glad I only have a half-dozen readers) mention a few other orders: 1, 2, 3, 4, 5, 6 ("to get the crap out of the way"), or the flip-flop 1, 4, 2, 5, 3, 6 (tracking both in single steps).

There's a little part of me that wishes we tried the flashback-in-the-middle approach, but the only thing that matters is that our girls enjoyed the movies, and now they get one or two more of the jokes Wendy and I make.

For Illumos newbies: On developing small

I just finished a chat with a person who's doing a device driver, and he was worried that a certain header file wasn't available in his /usr/include. This struck me as odd, as I always get my headers from the workspace's proto area...

Then I realized I've had 15 years at Sun under my belt and this person's a complete newbie.

I haven't looked very closely at the Illumos build instructions, but I'm going to do some things now that will help kernel module writers (e.g. device drivers) get started without resorting to a full build right off the bat. I'll assume that you've installed the appropriate compilers and the "onbld" package so that you have a populated /opt/onbld/bin.

STEP 1: The /opt/onbld/bin/ws command:

When you go to work in an Illumos source base, your best off "entering it" via the ws command. I've hacked my .tcshrc to print a different prompt when I'm in with ws. Here, check it out:

everywhere(~)[1]% ws ws/to_mhi

Workspace                    : /export/home/danmcd/ws/to_mhi
Workspace Parent             : /export/home/danmcd/ws/illumos-clone
Proto area ($ROOT)           : /export/home/danmcd/ws/to_mhi/proto/root_i386
Parent proto area ($PARENT_ROOT) : /export/home/danmcd/ws/illumos-clone/proto/root_i386
Root of source ($SRC)        : /export/home/danmcd/ws/to_mhi/usr/src
Root of test source ($TSRC)  : /export/home/danmcd/ws/to_mhi/usr/ontest
Current directory ($PWD)     : /export/home/danmcd/ws/to_mhi

WS-everywhere-WS(~/ws/to_mhi)[0]% 

You'll notice a few things got set in the environment. What I use to alter my .tcshrc is the CODEMGR_WS variable. You should do the same in your favorite shell's config.

UPDATE: You will need to set SPRO_ROOT and BUILD_TOOLS after invoking ws. I do this already in my .tcshrc, but forgot to report it. A newer tool: bldenv, fixes this, but currently at the cost of a configuration file. There's talk of merging ws's simplicity with bldenv's completeness.

One of the key concepts in building Illumos is the "proto area". This is a version of the root filesystem that lives within your source tree. You'll see it set above. There's one per basic architecture type (i386 or sparc). When a full "nightly" build happens, the proto area gets populated with headers, libraries, commands, kernel modules, etc., and then the packaging tools sweep up their input from the proto area. The proto area contains more than what is on a running system.

You need to populate your proto area with basics (directory structures, etc.) to start.

WS-everywhere-WS(~/ws/to_mhi)[1]% cd $SRC
WS-everywhere-WS(usr/src)[0]% pwd
/export/home/danmcd/ws/to_mhi/usr/src
WS-everywhere-WS(usr/src)[0]% dmake sgs
       < Go get a drink of water or coffee, it's gonna be a bit... >
WS-everywhere-WS(usr/src)[1]% 

The "sgs" target sets up the proto area completely.

If you're proceeding to build, say, kernel modules, you should populate the kernel include files in the proto area.

WS-everywhere-WS(~/ws/to_mhi)[0]% cd usr/src/uts
WS-everywhere-WS(src/uts)[0]% dmake install_h
    < TONS of output deleted... >
WS-everywhere-WS(src/uts)[0]% 

UPDATE Fellow Illumos hacker Rich Lowe has informed me that "dmake setup" does both sgs and install_h in one fell swoop.

And then you can go and compile your kernel module. I'll use "ip" as an example:

WS-everywhere-WS(src/uts)[1]% cd intel/ip
WS-everywhere-WS(intel/ip)[0]% pwd
/export/home/danmcd/ws/to_mhi/usr/src/uts/intel/ip
WS-everywhere-WS(intel/ip)[0]% dmake
     < MORE output deleted... >
WS-everywhere-WS(intel/ip)[0]% 

If you want to lint-check your module, don't do the obvious "make lint" but instead do "make modlintlib". This will perform basic lint sanity without the overhead of a full crosscheck.

Now if you want to do something in userland, you'll need to do more than a simple header install. You MIGHT need to bringup libraries too, because it's possible your workspace's libraries have different versions than the machine you're actually building on.

WS-everywhere-WS(intel/ip)[0]% cd $SRC/lib
WS-everywhere-WS(src/lib)[0]% 

If you utter "dmake install", it's going to be a while. You can, if you know only a certain library was altered, cd into that library and utter "dmake install" in there. For example:

WS-everywhere-WS(src/lib)[0]% cd libipsecutil
WS-everywhere-WS(lib/libipsecutil)[0]% dmake install_h
     < output deleted... >
WS-everywhere-WS(lib/libipsecutil)[0]% dmake install
     < MORE output deleted... >
WS-everywhere-WS(lib/libipsecutil)[0]% 

Then you can go to, say, your new command, and start compiling and debugging there. Once you're done, you can exit this shell, and it will return you to your original pre-ws shell.

Hopefully this will lower some of the barriers to entry for budding Illumos hackers.

Finally unpacked

I think I've managed to move all of my old blog entries over from blogs.sun.com. Hopefully I'll be posting some Illumos-related technical content before too long. Stay tuned!

Hello again, world!

At Wendy's and Garrett's advice, I've set up shop here on Blogger/Blogspot.

I plan on importing all of my old Sun blog posts here, but I exported in a non-blogger non-XML (ick) format. So I'll be backpatching by copy-and-paste when time allows.

Happy blog reading, you half-dozen readers! :)

A final suggested read

David Reed passed along a pointer to this paper by Dan Geer:

A Time for Choosing

Please read it, and understand the founding spirit of the Internet. And with that, I say goodbye to Oracle.

I'm leaving Oracle, and switching gears

15 years ago I was finishing up last-minute changes at NRL while getting ready to move coasts. While I'm not moving coasts, I'm at the point where I'm finishing up last-minute changes again.

I'm leaving Oracle this week, and will be trying something a bit different after that. I've been doing IPsec or at least TCP/IP related work for the entirety of my time at Sun. I expect to be back in TCP/IP-land relatively soon, but I will be learning some new-to-me technologies in the immediate future.

I've met and worked with some extraordinary people during my time at Sun. I hope to keep in touch with them after I depart. If any of you half-dozen readers wish to keep up, I'd suggest following my Twitter feed until I decide whether or not I find a new home for this blog. I'm also findable on Facebook and LinkedIn for those so inclined.

MAC-then-encrypt - also harmful, also hard to do in Solaris

Hello again!

Kenny Paterson's once again turning the theoretical into practical. This time he's pointed out that if one configures IPsec to MAC-then-encrypt (do packet authentication first, THEN encrypt the packet), one is open to cryptographic attack. Here's a citation for his ACM CCS paper.

The good news is that we cannot configure the IPsec SPD to perform MAC-then-encrypt at all. One could configure transport mode to just MAC, then have the packet transit a tunnel that just encrypts, but then you'll see warnings about the encryption-only tunnel configuration. This has been true for a LONG time (starting with S9, maybe even S8).

So basically, we don't make it easy for you to shoot yourself in the foot this way. You really have to try, and as I pointed out earlier, the encryption-only part will warn you.