- Don't rename libbpf's bpf_map_def struct, and distribute the needed bpf
headers.
The bpf_map_def struct has been deprecated for quite some time now,
and it was been removed on >= 6.2 anyway.
We still need it, because we use gobpf.
- Improved compilation behaviour:
- We don't require the kernel sources anymore. We can just use the
kernel headers from the distribution.
- There's no need to copy the sources to the kernel tree, the modules
can be compiled from the ebpf_prog/ dir.
- Compiling against kernels 6.x seems to solve the problem we had with
VPNs, where connections were not intercepted with modules compiled
against 5.8, on kernels >= 5.19.
The modules has been tested on kernels 4.17, 5.4, 5.10, 5.15, 6.1 and
6.2 (kernel connections included).
Closes: #939
* Use ebpf program to find PID of new connections.
before running the branch you have to compile ebpf_prog/opensnitch.c
opensnitch.c is an eBPF program. Compilation requires getting kernel source.
cd opensnitch
wget https://github.com/torvalds/linux/archive/v5.8.tar.gz
tar -xf v5.8.tar.gz
patch linux-5.8/tools/lib/bpf/bpf_helpers.h < ebpf_prog/file.patch
cp ebpf_prog/opensnitch.c ebpf_prog/Makefile linux-5.8/samples/bpf
cd linux-5.8 && yes "" | make oldconfig && make prepare && make headers_install # (1 min)
cd samples/bpf && make
objdump -h opensnitch.o #you should see many section, number 1 should be called kprobe/tcp_v4_connect
llvm-strip -g opensnitch.o #remove debug info
sudo cp opensnitch.o /etc/opensnitchd
cd ../../../daemon
--opensnitchd expects to find opensnitch.o in /etc/opensnitchd/
--start opensnitchd with:
opensnitchd -rules-path /etc/opensnitchd/rules -process-monitor-method ebpf
Co-authored-by: themighty1 <you@example.com>
Co-authored-by: Gustavo Iñiguez Goia <gooffy1@gmail.com>
