This guide contains information on how you can build and test katran's BPF forwarding plane and cpp library to control it.
We are using clang-format for C++ code formatting. Please make sure that code is properly
formatted before sending PR. You can format it with clang-format -i <path/to/file>
(if your linux distribution does not have clang-format installed, you can use one from the
deps folder: ./deps/clang/clang+llvm-5.0.0-linux-x86_64-ubuntu16.04/bin/clang-format
)
You can build the initial version with build_katran.sh
script (if you are using
ubuntu 18.04). It will download all required dependencies and build
actual binaries. However, you can build everything separately.
To be able to build BPF forwarding plane you need to run
build_bpf_modules_opensource.sh
from the root of the working directory. It assumes
that you have all dependencies installed and that the linux kernel source code
is located at deps/linux/
(Note: It is automatically installed there with the script: build_katran.sh
).
The result of this script will be object files w/ BPF programs, which are going
to be located in deps/linux/bpfprog/bpf/
. These files are:
balancer_kern.o
- object file w/ main BPF program for forwardinghealthchecking_ipip.o
- object file w/ BPF program for the forwarding of healthchecks
To be able to build C++ library (and examples) you need to:
- create (if it doesn't exist already)
build dir
- run
cmake ..
inside thisbuild dir
If you are adding new features into C++ library, please make sure that you also submit
unittests for them (all BPF specific calls should be added into if(!testing_){...}
block
as they require root access (most of the time). You can run unittests manually or w/ ctest
util.
$ pwd
$HOME/katran/build/katran/lib/tests
$ ctest
Test project build/katran/lib/tests
Start 1: IpHelpersTests
1/4 Test #1: IpHelpersTests ................... Passed 0.00 sec
Start 2: CHHelpersTests
2/4 Test #2: CHHelpersTests ................... Passed 0.01 sec
Start 3: LibKatranTests
3/4 Test #3: LibKatranTests ................... Passed 0.26 sec
Start 4: VipTests
4/4 Test #4: VipTests ......................... Passed 0.03 sec
100% tests passed, 0 tests failed out of 4
Total Test time (real) = 0.31 sec
$
We have developed a special framework for the BPF program testing. It is based on
bpf_prog_test_run
. This framework allow us to specify predefined test fixtures (input and expected output)
to make sure that for a specified input, the BPF program produces expected output. Test fixtures in our case contain
base64 encoded packets. You can check katran/lib/testing/KatranTestFixtures.h
for examples. To run these tests
you just need to run ./os_run_tester.sh
script (this script requires root privileges).
$ ./os_run_tester.sh
++ pwd
++ pwd
+ sudo sh -c '/home/username/katran_oss/build/katran/lib/testing/katran_tester -balancer_prog /home/username/katran_oss/deps/linux/bpfprog/bpf/balancer_kern.o -test_from_fixtures=true '
E0318 15:21:07.659436 28440 BpfLoader.cpp:144] Can't read section size for index: 2
I0318 15:21:07.659950 28440 BpfLoader.cpp:419] Skipping section: 2 of file: /home/username/katran_oss/deps/linux/bpfprog/bpf/balancer_kern.o
I0318 15:21:07.692260 28440 BpfLoader.cpp:338] relocation for non existing prog w/ idx 10
I0318 15:21:07.692790 28440 BpfLoader.cpp:338] relocation for non existing prog w/ idx 14
I0318 15:21:07.693243 28440 BpfLoader.cpp:338] relocation for non existing prog w/ idx 16
I0318 15:21:07.693667 28440 BpfLoader.cpp:338] relocation for non existing prog w/ idx 18
I0318 15:21:07.694093 28440 BpfLoader.cpp:338] relocation for non existing prog w/ idx 20
I0318 15:21:07.701683 28440 KatranLb.cpp:378] adding new vip: 10.200.1.1:80:17
I0318 15:21:07.865139 28440 KatranLb.cpp:378] adding new vip: 10.200.1.1:80:6
I0318 15:21:08.022128 28440 KatranLb.cpp:378] adding new vip: 10.200.1.2:0:6
I0318 15:21:08.178966 28440 KatranLb.cpp:378] adding new vip: 10.200.1.4:0:6
I0318 15:21:08.327633 28440 KatranLb.cpp:443] modyfing vip: 10.200.1.4:0:6
I0318 15:21:08.328361 28440 KatranLb.cpp:378] adding new vip: 10.200.1.3:80:6
I0318 15:21:08.481209 28440 KatranLb.cpp:378] adding new vip: fc00:1::1:80:6
I0318 15:21:08.631790 28440 KatranLb.cpp:378] adding new vip: 10.200.1.5:443:17
I0318 15:21:08.632745 28440 KatranLb.cpp:443] modyfing vip: 10.200.1.5:443:17
I0318 15:21:08.788859 28440 KatranLb.cpp:378] adding new vip: fc00:1::2:443:17
I0318 15:21:08.789475 28440 KatranLb.cpp:443] modyfing vip: fc00:1::2:443:17
I0318 15:21:08.938019 28440 XdpTester.cpp:142] Test: packet to UDP based v4 VIP (and v4 real) result: Passed
I0318 15:21:08.938712 28440 XdpTester.cpp:142] Test: packet to TCP based v4 VIP (and v4 real) result: Passed
I0318 15:21:08.939400 28440 XdpTester.cpp:142] Test: packet to TCP based v4 VIP (and v4 real; any dst ports). result: Passed
I0318 15:21:08.940088 28440 XdpTester.cpp:142] Test: packet to TCP based v4 VIP (and v6 real) result: Passed
I0318 15:21:08.940827 28440 XdpTester.cpp:142] Test: packet to TCP based v6 VIP (and v6 real) result: Passed
I0318 15:21:08.941443 28440 XdpTester.cpp:142] Test: v4 ICMP echo-request result: Passed
I0318 15:21:08.941794 28440 XdpTester.cpp:142] Test: v6 ICMP echo-request result: Passed
I0318 15:21:08.942143 28440 XdpTester.cpp:142] Test: v4 ICMP dest-unreachabe fragmentation-needed result: Passed
I0318 15:21:08.942488 28440 XdpTester.cpp:142] Test: v6 ICMP packet-too-big result: Passed
I0318 15:21:08.942817 28440 XdpTester.cpp:142] Test: drop of IPv4 packet w/ options result: Passed
I0318 15:21:08.943133 28440 XdpTester.cpp:142] Test: drop of IPv4 fragmented packet result: Passed
I0318 15:21:08.943462 28440 XdpTester.cpp:142] Test: drop of IPv6 fragmented packet result: Passed
I0318 15:21:08.943747 28440 XdpTester.cpp:142] Test: pass of v4 packet with dst not equal to any configured VIP result: Passed
I0318 15:21:08.944027 28440 XdpTester.cpp:142] Test: pass of v6 packet with dst not equal to any configured VIP result: Passed
I0318 15:21:08.944326 28440 XdpTester.cpp:142] Test: pass of arp packet result: Passed
I0318 15:21:08.944638 28440 XdpTester.cpp:142] Test: LRU hit result: Passed
I0318 15:21:08.944896 28440 XdpTester.cpp:142] Test: packet #1 dst port hashing only result: Passed
I0318 15:21:08.945171 28440 XdpTester.cpp:142] Test: packet #2 dst port hashing only result: Passed
I0318 15:21:08.945444 28440 XdpTester.cpp:142] Test: ipinip packet result: Passed
I0318 15:21:08.945725 28440 XdpTester.cpp:142] Test: ipv6inipv6 packet result: Passed
I0318 15:21:08.945996 28440 XdpTester.cpp:142] Test: ipv4inipv6 packet result: Passed
I0318 15:21:08.946280 28440 XdpTester.cpp:142] Test: QUIC: long header. Client Initial type result: Passed
I0318 15:21:08.946561 28440 XdpTester.cpp:142] Test: QUIC: long header. 0-RTT Protected result: Passed
I0318 15:21:08.946645 28440 XdpTester.cpp:142] Test: QUIC: long header. v4 vip v6 real result: Passed
I0318 15:21:08.946728 28440 XdpTester.cpp:142] Test: QUIC: long header. v6 vip v6 real result: Passed
I0318 15:21:08.946970 28440 XdpTester.cpp:142] Test: QUIC: short header. no connection id result: Passed
I0318 15:21:08.947049 28440 XdpTester.cpp:142] Test: QUIC: short header w/ connection id result: Passed
I0318 15:21:08.947124 28440 XdpTester.cpp:142] Test: QUIC: short header w/ connection id but non-existing mapping result: Passed
I0318 15:21:08.947191 28440 katran_tester.cpp:135] Testing counter's sanity. Printing on errors only
I0318 15:21:08.947327 28440 katran_tester.cpp:156] Testing of counters is complite
$