So the problem is that when I am trying to apply a patch, e.g IPMARK, I am receiving an error:
The thing I did before:
and followed README to install ipset.
I am calling patch-o-matic with this command:
The kernel tree is 2.6.30.4.
The iptables' one is 1.4.0.

Hi there. I'm not entirely sure I can be much use, but hopefully I can point you in the right direction...

It sounds to me like the patch it's trying to apply isn't suitable for the kernel you're running. This kind of thing will happen when manually patching the kernel if you've used an incorrect patch version or applied the patch from the wrong place in the tree.

First stage is to check that the "/tmp/pom-2459/net/ipv4/netfilter/Makefile" file exists.

Next have a look inside the patch file (./patchlets/IPMARK/linux-2.6/./net/ipv4/netfilter/Makefile.ladd) and see if you can make head or tail of what it's trying to do.

If you can work out what it's supposed to do, then have a look at the contents of the first file and check that the code chunk where it's trying to insert the patch is identical in format to the way in which it is displayed in the .ladd file.

Unfortunately I don't know anything about the program you're using to apply the patch, so I can't really help on that front, but hopefully this has given you a couple of ideas.

X-T

As far as I know, POM is super-old and outdated. I used it for a long time way back when, but slowly the patches either stopped with the current kernel or merged into it. I'm talking pre-2.6.20-ish if I remember correctly. I'd stick with the in-kernel stuff. There's quite alot in the current 2.6.31.1.