Allow to customize:
- EventsWorkers: number of goroutines to handle kernel events.
Default 8.
- QueueEventsSize: max number of events in the queue.
By default 0, meaning that it'll relay on the available goroutines to
process the events. If it's > 0, and the daemon can't process the
events fast enough, they'll be queued. Once the queue is full, it'll
behave as it was of size 0.
If there're lost events, a message will be logged: "Lost ebpf events..."
Now it's possible to configure eBPF modules path from the
default-config.json file:
"Ebpf": {
"ModulesPath": "..."
}
If the option is not provided, or if it's empty, we'll keep loading from
the default directories:
- /usr/local/lib/opensnitchd/ebpf
- /usr/lib/opensnitchd/ebpf
- /etc/opensnitchd/ebpf (deprecated, will be removed in the future).
Closes#928
Now you can create rules to filter processes by checksum. Only md5 is
available at the moment.
There's a global configuration option that you can use to enable or
disable this feature, from the config file or from the Preferences
dialog.
As part of this feature there have been more changes:
- New proc monitor method (PROCESS CONNECTOR) that listens for
exec/exit events from the kernel.
This feature depends on CONFIG_PROC_EVENTS kernel option.
- Only one cache of active processes for ebpf and proc monitor
methods.
More info and details: #413.
- Fixed reloading process monitor method if the configuration changes on
disk. This can occur in two situations: 1) if it's changed from the
UI, 2) if the user changes it manually.
- Ensure that we don't crash if there's an error changing the
method and ebpf is active.
- When changing monitor method to ebpf and it fails to start, stop it
anyway. It helps cleaning up kprobes and avoiding the error
"cannot write...: file exists".
* 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>
