Starting work on a DSAPI filter for Domino 8.5.2 on 64-bit Ubuntu
Apr 14, 2011, 4:33 PM
For my main project, which contains a forum, one of the problems I ran into was Domino's session handling. Namely, it's designed such that HTTP user sessions last for the duration of the browser session and time out after 30 minutes. That's fine for, say, a corporate app, where you don't want a client logged in indefinitely. However, having to re-log-in to a forum every time you visit it would be a hassle.
The session timeout is easy to fix - you can just up the timeout period in the web site config. The cookie took a little more trickery, but wasn't too bad either. I set up some code in the beforePageLoad event to look for a
DomAuthSessId cookie and, if present, create a persistent cookie. The server can't tell the difference between the session and persistent cookies, so this works.
However, it's sort of ugly. While I absolutely don't want to have people re-log-in every time they restart their browser, I also don't really want tons of session-scoped managed beans floating around for months, and this kind of trick defeats any use of the Internet Users list in Domino Administrator (a minor quibble, but a quibble nonetheless). Ideally, I'd be able to automatically log people in on subsequent visits, but not have to actually maintain server sessions for them. From all I've read, this calls for a DSAPI filter. Since that involves C/C++, there's bound to be a lot of setup and tribulation.
First off, I had to grab the Notes/Domino C API toolkit. Fortunately, Google led me directly to the IBM download page and, after re-confirming that I don't want them to send me email, I was given a download link for a quaintly
compress'ed file and some installation instructions. I dropped the libraries into /opt/ibm/lotus/notesapi and set up a symlink at /opt/lotus/notesapi just in case. The samples in the toolkit do indeed include a DSAPI filter, and I found another one doing something very much like what I want here:
To keep things simple, I started with that code and commented/deleted everything that actually does something - I just wanted the simplest possible filter to see if it works at all. All it does is announce that it's alive and then proceed to not handle any requests:
Now came the issues. First off, the DSAPI example in the toolkit only came with a handful of Makefiles, and none for Linux. The Solaris one was close, so I borrowed and modified that one with some tips from http://www-10.lotus.com/ldd/nd6forum.nsf/55c38d716d632d9b8525689b005ba1c0/fbd4bb196ce4146685256df10038a0b9?OpenDocument . The most vital thing was that, since I'm running in a 64-bit environment but using a 32-bit Domino server, I had to go out of my way to compile a 32-bit library - this is done by adding "-m32" to the CCOPTS and (maybe required) LIBS lines. The Makefile I ended up using is:
Along the lines of the "-m32" flag, I had to install some additional development libraries to support 32-bit compiling. In my travails, I ended up installing all sorts of apt packages before it worked, so it's possible that only the last (or another, non-C++ library) is necessary:
Unfortunately, even when you get the library building properly, it's tough to get it to load into Domino, and it's not very helpful as to why - all it says is "Failed to load DSAPI filter: " and then the file name... and it gives the same error if you point it to a non-existent file, so there's no way of knowing WHY it failed to load it. It's all trial and error (unless you actually know what you're doing, presumably).
Once all that was in line, though, I could build the library with
make, copy it to /opt/ibm/lotus/notes/latest/linux, add "libdsapilogin.so" to the Configuration tab of my Web Site document in the Directory, and restart HTTP. When HTTP is loading, it will print out "HTTP Server: DSAPI DSAPIDLL Loaded successfully" (or whatever message you put in there), so you know it's working.
Now comes the task of actually writing the filter. Considering that I haven't written any C or C++ since college, I expect lots of fun with buffer overflows and mysterious crashes. Exciting!