I haven't used Eclipse for a C or C++ project in over a year, and I never used it that much to begin with, so I'm not too savy on it. I'll try to get it set up and give it a go later on. However, the IDE attempts to determine problems with your code before you compile it and if that fails, it reports those errors. Probabaly, the way to eliminate that (if you are on linux) is to add /usr/include to your includes or something (it's defined in sys/ioctl.h, which usually includes bits/ioctl.h and/or asm/ioctl.h). You may be able to configure Eclipse to use jam instead of make, but I think the current jam build system lacks the ability to compile source files individually (or I haven't figured out what to tell it to do that yet). Either way, I run jam with -gj5, the -g tells it to compile the most recently modified source files first and the -j5 tells it to run 5 processes at once, so compilation is faster. make will also accept -jx (where x is a number).
As for the rest of the errors, that's been a long standing issue with Eclipse in my experience. It's a matter of telling the IDE all of the information that your build system also uses, so they have the same information and don't flag problems that aren't real. I'm glad that you got it compiling though! As I mentioned in the network code thread, I'll be a bit out of pocket for another week or so, after which I will attend the board a little better
