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#ebpf
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# ebpf
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alessandrogario
09/29/2020, 4:39 PM
Latest packages for BPF support. This adds back bpf_socket_events with listen, accept, accept4, socket and connect. There are still no unit tests for this table, so expect hidden bugs!
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CptOfEvilMinions
09/29/2020, 5:20 PM@alessandrogario are these packages OS and version specific? Will this run on ubuntu server 20.04?
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alessandrogario
09/29/2020, 5:21 PM
They have been built with the osquery toolchain, so they should be portable
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CptOfEvilMinions
09/29/2020, 5:33 PMI download the ZIP provided and I installed.
Based on the PR and this Slack channel I ran the following command:
sudo osqueryd -S --verbose --enable_bpf_socket_events --enable_bpf_process_events --disable_events=false Copy code
ubuntuvm:/tmp/20200929_osquery_pr6571_bpf$ sudo osqueryd -S --verbose --enable_bpf_socket_events --enable_bpf_process_events --disable_events=false
ERROR: unknown command line flag 'enable_bpf_process_events'
ERROR: unknown command line flag 'enable_bpf_socket_events'a
alessandrogario
09/29/2020, 5:37 PM
aaargh I need to update the docs. So since I need to trace all the syscalls regardless of which table the user wants to use, i removed those flags
the only flag required is --enable_bpf_events
There are some quirks with the openat/openat2 syscall; looks like you don't always have access to the memory you are required to read because those pages are not mapped. I tried to add some workarounds to this, but it may still throw some "Malformed event for tracer #x" warnings
Also: there are no options yet to control how much memory to allocate in the ring buffers, which would be helpful to increase when you know you are going to handle a certain number of events per minute
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CptOfEvilMinions
09/29/2020, 5:46 PMI had an Ubuntu server 20.04.1 64-bit machine with 2GBs of memory and it was not enough
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alessandrogario
09/29/2020, 5:52 PM
Yeah, it's the following settings inside bpfeventpublisher.cpp:
Copy code
const std::size_t kPerfEventArraySize{12U};
const std::size_t kBufferStorageSize{4096U};
const std::size_t kEventMapSize{2048};2 Views