Katran reload bpf (#96)

Summary: this PR contains two diffs. first one revert ef8a0b3 as 2nd one allows to solve the same usecase (which is not yet implemented in that reverted diff) in more generic way. 2nd diff contains a logic to reload balancer's program in runtime w/ minimum to none disruption. it archives this by: loading new bpf program. but for that program all maps, which were loaded/populated in original version, would be reused instead of creating a new one and populating em. e.g. by doing this we would preserv connection tracking maps and existing flow wont be affected. missed maps (e.g. the ones which exist only in new version) would be created if needed. as a part of this logic optionally new config could be provided (e.g. if new code requires src ip to be specified and old one does not: e.g. for gue encap). This new feature does not handle cleanup logic (e.g. if new (reloaded) balancer's code requires less maps than original one, unused maps wont be removed/freed). right now it is questionable if such ability would be useful and it is definitely would increase complexity). Aside from reloading balancer program, it should be also reattached. so user of the library should do something like: ``` 1. lb.reloadBalancerProg(path) << to reload bpf program. at this point old one is still attached, so forwarding still would be done by old bpf program. 2. lb.attachBpfProgs() << reattaching new bpf program (either to interface directly, or to the shared prog array). in both cases this (reattachment in kernel) is done under RCU/lock so it is safe to do in runtime and wont disrupt any traffic. ``` right now reloading of healthchecking program is not supported. Note on maps renaming: libbpf's way to share map between different bpf program's requires for map's name to be no more than 15 chars. hence some names were shortened. Some reload examples/tests: 1. original code does not have introspection enabled, but reloaded does: ``` ./os_run_tester.sh "-reloaded_balancer_prog=/tmp/balancer_kern.o -iobuf_storage" + '[' -z '' ']' ++ pwd + KATRAN_BUILD_DIR=/home/tehnerd/projects/sdd/projects/katran/_build/build + '[' -z '' ']' ++ pwd + DEPS_DIR=/home/tehnerd/projects/sdd/projects/katran/_build/deps + sudo sh -c '/home/tehnerd/projects/sdd/projects/katran/_build/build/katran/lib/testing/katran_tester -balancer_prog /home/tehnerd/projects/sdd/projects/katran/_build/deps/bpfprog/bpf/balancer_kern.o -test_from_fixtures=true -reloaded_balancer_prog=/tmp/balancer_kern.o -iobuf_storage' E0912 04:25:11.888264 3031 BpfLoader.cpp:94] Can't find map w/ name: lpm_src_v4 E0912 04:25:11.888324 3031 BpfLoader.cpp:94] Can't find map w/ name: decap_dst E0912 04:25:11.888327 3031 BpfLoader.cpp:94] Can't find map w/ name: event_pipe E0912 04:25:11.888329 3031 BpfLoader.cpp:94] Can't find map w/ name: pckt_srcs E0912 04:25:11.888332 3031 BpfLoader.cpp:94] Can't find map w/ name: hc_pckt_srcs_map I0912 04:25:11.888345 3031 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:17 I0912 04:25:11.936579 3031 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:6 I0912 04:25:11.980474 3031 KatranLb.cpp:717] adding new vip: 10.200.1.2:0:6 I0912 04:25:12.025903 3031 KatranLb.cpp:717] adding new vip: 10.200.1.4:0:6 I0912 04:25:12.071620 3031 KatranLb.cpp:821] modyfing vip: 10.200.1.4:0:6 I0912 04:25:12.071635 3031 KatranLb.cpp:717] adding new vip: 10.200.1.3:80:6 I0912 04:25:12.117257 3031 KatranLb.cpp:717] adding new vip: fc00:1::1:80:6 I0912 04:25:12.163430 3031 KatranLb.cpp:717] adding new vip: 10.200.1.5:443:17 I0912 04:25:12.163468 3031 KatranLb.cpp:821] modyfing vip: 10.200.1.5:443:17 I0912 04:25:12.209666 3031 KatranLb.cpp:717] adding new vip: fc00:1::2:443:17 I0912 04:25:12.209704 3031 KatranLb.cpp:821] modyfing vip: fc00:1::2:443:17 I0912 04:25:12.256033 3031 BpfTester.cpp:220] Test: packet to UDP based v4 VIP (and v4 real) result: Passed I0912 04:25:12.256158 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) result: Passed I0912 04:25:12.256224 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) + ToS in IPV4 result: Passed I0912 04:25:12.256345 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real; any dst ports). result: Passed I0912 04:25:12.256420 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v6 real) result: Passed I0912 04:25:12.256491 3031 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) result: Passed I0912 04:25:12.256561 3031 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) with ToS / tc set result: Passed I0912 04:25:12.256614 3031 BpfTester.cpp:220] Test: v4 ICMP echo-request result: Passed I0912 04:25:12.256640 3031 BpfTester.cpp:220] Test: v6 ICMP echo-request result: Passed I0912 04:25:12.256667 3031 BpfTester.cpp:220] Test: v4 ICMP dest-unreachabe fragmentation-needed result: Passed I0912 04:25:12.256701 3031 BpfTester.cpp:220] Test: v6 ICMP packet-too-big result: Passed I0912 04:25:12.256772 3031 BpfTester.cpp:220] Test: drop of IPv4 packet w/ options result: Passed I0912 04:25:12.256798 3031 BpfTester.cpp:220] Test: drop of IPv4 fragmented packet result: Passed I0912 04:25:12.256824 3031 BpfTester.cpp:220] Test: drop of IPv6 fragmented packet result: Passed I0912 04:25:12.256851 3031 BpfTester.cpp:220] Test: pass of v4 packet with dst not equal to any configured VIP result: Passed I0912 04:25:12.256877 3031 BpfTester.cpp:220] Test: pass of v6 packet with dst not equal to any configured VIP result: Passed I0912 04:25:12.256903 3031 BpfTester.cpp:220] Test: pass of arp packet result: Passed I0912 04:25:12.256932 3031 BpfTester.cpp:220] Test: LRU hit result: Passed I0912 04:25:12.256958 3031 BpfTester.cpp:220] Test: packet #1 dst port hashing only result: Passed I0912 04:25:12.256987 3031 BpfTester.cpp:220] Test: packet #2 dst port hashing only result: Passed I0912 04:25:12.257014 3031 BpfTester.cpp:220] Test: ipinip packet result: Passed I0912 04:25:12.257041 3031 BpfTester.cpp:220] Test: ipv6inipv6 packet result: Passed I0912 04:25:12.257069 3031 BpfTester.cpp:220] Test: ipv4inipv6 packet result: Passed I0912 04:25:12.257097 3031 BpfTester.cpp:220] Test: QUIC: long header. Client Initial type. LRU miss result: Passed I0912 04:25:12.257123 3031 BpfTester.cpp:220] Test: QUIC: long header. 0-RTT Protected. CH. LRU hit. result: Passed I0912 04:25:12.257149 3031 BpfTester.cpp:220] Test: QUIC: long header. Handshake. v4 vip v6 real. Conn Id based. result: Passed I0912 04:25:12.257176 3031 BpfTester.cpp:220] Test: QUIC: long header. Retry. v4 vip v6 real. Conn Id based. result: Passed I0912 04:25:12.257205 3031 BpfTester.cpp:220] Test: QUIC: long header. client initial. v6 vip v6 real. LRU miss result: Passed I0912 04:25:12.257232 3031 BpfTester.cpp:220] Test: QUIC: short header. No connection id. CH. LRU hit result: Passed I0912 04:25:12.257259 3031 BpfTester.cpp:220] Test: QUIC: short header w/ connection id result: Passed I0912 04:25:12.257325 3031 BpfTester.cpp:220] Test: QUIC: short header w/ connection id but non-existing mapping result: Passed I0912 04:25:12.257351 3031 BpfTester.cpp:220] Test: QUIC: short header w/ conn id. host id = 0. CH. LRU hit result: Passed I0912 04:25:12.257402 3031 BpfTester.cpp:220] Test: UDP: big packet of length 1515. trigger PACKET TOOBIG result: Passed I0912 04:25:12.257406 3031 katran_tester.cpp:257] Testing counter's sanity. Printing on errors only I0912 04:25:12.257494 3031 katran_tester.cpp:313] Testing of counters is complete E0912 04:25:12.257956 3031 KatranSimulator.cpp:168] src and dst must have same address family E0912 04:25:12.257961 3031 KatranSimulator.cpp:161] malformed src or dst ip address. src: aaaa dst: bbbb I0912 04:25:12.257963 3031 katran_tester.cpp:337] Test katran monitor. <<<< NOTHING HERE. AS INTROSPECTION IS NOT ENABLED FOR ORIGINAL VERSION E0912 04:25:13.258879 3031 BpfLoader.cpp:104] Can't find prog with name: cls-hc I0912 04:25:13.258942 3031 katran_tester.cpp:179] Healthchecking not enabled. Skipping HC related tests libbpf: Error in bpf_create_map_xattr(event_pipe):ERROR: strerror_r(-524)=22(-524). Retrying without BTF. E0912 04:25:13.292759 3031 BpfLoader.cpp:94] Can't find map w/ name: lpm_src_v4 E0912 04:25:13.292776 3031 BpfLoader.cpp:94] Can't find map w/ name: decap_dst E0912 04:25:13.292783 3031 BpfLoader.cpp:94] Can't find map w/ name: pckt_srcs E0912 04:25:13.292788 3031 BpfLoader.cpp:94] Can't find map w/ name: hc_pckt_srcs_map I0912 04:25:13.293278 3031 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:17 I0912 04:25:13.293290 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293299 3031 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:6 I0912 04:25:13.293303 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293306 3031 KatranLb.cpp:717] adding new vip: 10.200.1.2:0:6 I0912 04:25:13.293309 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293313 3031 KatranLb.cpp:717] adding new vip: 10.200.1.4:0:6 I0912 04:25:13.293320 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293329 3031 KatranLb.cpp:821] modyfing vip: 10.200.1.4:0:6 I0912 04:25:13.293337 3031 KatranLb.cpp:717] adding new vip: 10.200.1.3:80:6 I0912 04:25:13.293341 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293349 3031 KatranLb.cpp:717] adding new vip: fc00:1::1:80:6 I0912 04:25:13.293354 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293359 3031 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.1 I0912 04:25:13.293365 3031 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.2 I0912 04:25:13.293368 3031 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.3 I0912 04:25:13.293372 3031 KatranLb.cpp:1456] trying to add already existing mapping for fc00::1 I0912 04:25:13.293377 3031 KatranLb.cpp:1456] trying to add already existing mapping for fc00::2 I0912 04:25:13.293381 3031 KatranLb.cpp:1456] trying to add already existing mapping for fc00::3 I0912 04:25:13.293385 3031 KatranLb.cpp:717] adding new vip: 10.200.1.5:443:17 I0912 04:25:13.293390 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293392 3031 KatranLb.cpp:821] modyfing vip: 10.200.1.5:443:17 I0912 04:25:13.293399 3031 KatranLb.cpp:717] adding new vip: fc00:1::2:443:17 I0912 04:25:13.293403 3031 KatranLb.cpp:725] trying to add already existing vip I0912 04:25:13.293407 3031 KatranLb.cpp:821] modyfing vip: fc00:1::2:443:17 I0912 04:25:13.293608 3031 BpfTester.cpp:220] Test: packet to UDP based v4 VIP (and v4 real) result: Passed I0912 04:25:13.293678 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) result: Passed I0912 04:25:13.293714 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) + ToS in IPV4 result: Passed I0912 04:25:13.293747 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real; any dst ports). result: Passed I0912 04:25:13.293783 3031 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v6 real) result: Passed I0912 04:25:13.293820 3031 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) result: Passed I0912 04:25:13.293856 3031 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) with ToS / tc set result: Passed I0912 04:25:13.293889 3031 BpfTester.cpp:220] Test: v4 ICMP echo-request result: Passed I0912 04:25:13.293923 3031 BpfTester.cpp:220] Test: v6 ICMP echo-request result: Passed I0912 04:25:13.293959 3031 BpfTester.cpp:220] Test: v4 ICMP dest-unreachabe fragmentation-needed result: Passed I0912 04:25:13.293995 3031 BpfTester.cpp:220] Test: v6 ICMP packet-too-big result: Passed I0912 04:25:13.294030 3031 BpfTester.cpp:220] Test: drop of IPv4 packet w/ options result: Passed I0912 04:25:13.294064 3031 BpfTester.cpp:220] Test: drop of IPv4 fragmented packet result: Passed I0912 04:25:13.294096 3031 BpfTester.cpp:220] Test: drop of IPv6 fragmented packet result: Passed I0912 04:25:13.294131 3031 BpfTester.cpp:220] Test: pass of v4 packet with dst not equal to any configured VIP result: Passed I0912 04:25:13.294165 3031 BpfTester.cpp:220] Test: pass of v6 packet with dst not equal to any configured VIP result: Passed I0912 04:25:13.294199 3031 BpfTester.cpp:220] Test: pass of arp packet result: Passed I0912 04:25:13.294234 3031 BpfTester.cpp:220] Test: LRU hit result: Passed I0912 04:25:13.294315 3031 BpfTester.cpp:220] Test: packet #1 dst port hashing only result: Passed I0912 04:25:13.294358 3031 BpfTester.cpp:220] Test: packet #2 dst port hashing only result: Passed I0912 04:25:13.294399 3031 BpfTester.cpp:220] Test: ipinip packet result: Passed I0912 04:25:13.294474 3031 BpfTester.cpp:220] Test: ipv6inipv6 packet result: Passed I0912 04:25:13.294514 3031 BpfTester.cpp:220] Test: ipv4inipv6 packet result: Passed I0912 04:25:13.294555 3031 BpfTester.cpp:220] Test: QUIC: long header. Client Initial type. LRU miss result: Passed I0912 04:25:13.294595 3031 BpfTester.cpp:220] Test: QUIC: long header. 0-RTT Protected. CH. LRU hit. result: Passed I0912 04:25:13.294633 3031 BpfTester.cpp:220] Test: QUIC: long header. Handshake. v4 vip v6 real. Conn Id based. result: Passed I0912 04:25:13.294672 3031 BpfTester.cpp:220] Test: QUIC: long header. Retry. v4 vip v6 real. Conn Id based. result: Passed I0912 04:25:13.294713 3031 BpfTester.cpp:220] Test: QUIC: long header. client initial. v6 vip v6 real. LRU miss result: Passed I0912 04:25:13.294751 3031 BpfTester.cpp:220] Test: QUIC: short header. No connection id. CH. LRU hit result: Passed I0912 04:25:13.294791 3031 BpfTester.cpp:220] Test: QUIC: short header w/ connection id result: Passed I0912 04:25:13.294831 3031 BpfTester.cpp:220] Test: QUIC: short header w/ connection id but non-existing mapping result: Passed I0912 04:25:13.294868 3031 BpfTester.cpp:220] Test: QUIC: short header w/ conn id. host id = 0. CH. LRU hit result: Passed I0912 04:25:13.294950 3031 BpfTester.cpp:220] Test: UDP: big packet of length 1515. trigger PACKET TOOBIG result: Passed I0912 04:25:13.294958 3031 katran_tester.cpp:257] Testing counter's sanity. Printing on errors only I0912 04:25:13.294987 3031 katran_tester.cpp:261] per Vip counter is incorrect for vip:10.200.1.1 I0912 04:25:13.295011 3031 katran_tester.cpp:266] LRU counter is incorrect I0912 04:25:13.295030 3031 katran_tester.cpp:271] per pckt type LRU miss counter is incorrect I0912 04:25:13.295051 3031 katran_tester.cpp:276] LRU fallback counter is incorrect I0912 04:25:13.295070 3031 katran_tester.cpp:280] Counters for QUIC packets routed with CH: 10, with connection-id: 8 I0912 04:25:13.295078 3031 katran_tester.cpp:282] Counters for routing of QUIC packets is wrong. I0912 04:25:13.295100 3031 katran_tester.cpp:296] incorrect stats for real: 10.0.0.1 I0912 04:25:13.295109 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295128 3031 katran_tester.cpp:296] incorrect stats for real: 10.0.0.2 I0912 04:25:13.295136 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295156 3031 katran_tester.cpp:296] incorrect stats for real: 10.0.0.3 I0912 04:25:13.295164 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295186 3031 katran_tester.cpp:296] incorrect stats for real: fc00::1 I0912 04:25:13.295193 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295213 3031 katran_tester.cpp:296] incorrect stats for real: fc00::2 I0912 04:25:13.295222 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295243 3031 katran_tester.cpp:296] incorrect stats for real: fc00::3 I0912 04:25:13.295250 3031 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:25:13.295255 3031 katran_tester.cpp:313] Testing of counters is complete E0912 04:25:13.295521 3031 KatranSimulator.cpp:168] src and dst must have same address family E0912 04:25:13.295527 3031 KatranSimulator.cpp:161] malformed src or dst ip address. src: aaaa dst: bbbb I0912 04:25:13.295531 3031 katran_tester.cpp:337] Test katran monitor <<< RELOADED VERSION CONTAINS INTROSPECTION. SOME DATA ABOUT PACKETS WERE SENT THROUGH PERF PIPE I0912 04:25:14.296711 3031 katran_tester.cpp:167] buffer length is: 194 I0912 04:25:14.296993 3031 katran_tester.cpp:167] buffer length is: 168 E0912 04:25:14.297132 3031 BpfLoader.cpp:104] Can't find prog with name: cls-hc I0912 04:25:14.297152 3031 katran_tester.cpp:179] Healthchecking not enabled. Skipping HC related tests ``` another example balancer without gue vs w/ gue encap. ``` ./os_run_tester.sh "-reloaded_balancer_prog=/tmp/balancer_kern.o -gue" + '[' -z '' ']' ++ pwd + KATRAN_BUILD_DIR=/home/tehnerd/projects/sdd/projects/katran/_build/build + '[' -z '' ']' ++ pwd + DEPS_DIR=/home/tehnerd/projects/sdd/projects/katran/_build/deps + sudo sh -c '/home/tehnerd/projects/sdd/projects/katran/_build/build/katran/lib/testing/katran_tester -balancer_prog /home/tehnerd/projects/sdd/projects/katran/_build/deps/bpfprog/bpf/balancer_kern.o -test_from_fixtures=true -reloaded_balancer_prog=/tmp/balancer_kern.o -gue' E0912 04:31:14.927762 3131 BpfLoader.cpp:94] Can't find map w/ name: lpm_src_v4 E0912 04:31:14.927841 3131 BpfLoader.cpp:94] Can't find map w/ name: decap_dst E0912 04:31:14.927852 3131 BpfLoader.cpp:94] Can't find map w/ name: event_pipe E0912 04:31:14.927856 3131 BpfLoader.cpp:94] Can't find map w/ name: pckt_srcs E0912 04:31:14.927861 3131 BpfLoader.cpp:94] Can't find map w/ name: hc_pckt_srcs_map I0912 04:31:14.927877 3131 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:17 I0912 04:31:14.976330 3131 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:6 I0912 04:31:15.021167 3131 KatranLb.cpp:717] adding new vip: 10.200.1.2:0:6 I0912 04:31:15.067157 3131 KatranLb.cpp:717] adding new vip: 10.200.1.4:0:6 I0912 04:31:15.113668 3131 KatranLb.cpp:821] modyfing vip: 10.200.1.4:0:6 I0912 04:31:15.113682 3131 KatranLb.cpp:717] adding new vip: 10.200.1.3:80:6 I0912 04:31:15.160688 3131 KatranLb.cpp:717] adding new vip: fc00:1::1:80:6 I0912 04:31:15.207733 3131 KatranLb.cpp:717] adding new vip: 10.200.1.5:443:17 I0912 04:31:15.207773 3131 KatranLb.cpp:821] modyfing vip: 10.200.1.5:443:17 I0912 04:31:15.255038 3131 KatranLb.cpp:717] adding new vip: fc00:1::2:443:17 I0912 04:31:15.255079 3131 KatranLb.cpp:821] modyfing vip: fc00:1::2:443:17 MOST OF THE TESTS FAILED I0912 04:31:15.302585 3131 BpfTester.cpp:220] Test: packet to UDP based v4 VIP (and v4 real) result: Failed I0912 04:31:15.302676 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) result: Failed I0912 04:31:15.302933 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real; any dst ports). result: Failed I0912 04:31:15.303011 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v6 real) result: Failed I0912 04:31:15.303089 3131 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) result: Failed I0912 04:31:15.303159 3131 BpfTester.cpp:220] Test: v4 ICMP echo-request result: Passed I0912 04:31:15.303215 3131 BpfTester.cpp:220] Test: v6 ICMP echo-request result: Passed I0912 04:31:15.303270 3131 BpfTester.cpp:220] Test: v4 ICMP dest-unreachabe fragmentation-needed result: Failed I0912 04:31:15.303301 3131 BpfTester.cpp:220] Test: v6 ICMP packet-too-big result: Failed I0912 04:31:15.303329 3131 BpfTester.cpp:220] Test: drop of IPv4 packet w/ options result: Passed I0912 04:31:15.303357 3131 BpfTester.cpp:220] Test: drop of IPv4 fragmented packet result: Passed I0912 04:31:15.303386 3131 BpfTester.cpp:220] Test: drop of IPv6 fragmented packet result: Passed I0912 04:31:15.303414 3131 BpfTester.cpp:220] Test: pass of v4 packet with dst not equal to any configured VIP result: Passed I0912 04:31:15.303443 3131 BpfTester.cpp:220] Test: pass of v6 packet with dst not equal to any configured VIP result: Passed I0912 04:31:15.303472 3131 BpfTester.cpp:220] Test: pass of arp packet result: Passed I0912 04:31:15.303501 3131 BpfTester.cpp:220] Test: LRU hit result: Failed I0912 04:31:15.303530 3131 BpfTester.cpp:220] Test: packet #1 dst port hashing only result: Failed I0912 04:31:15.303560 3131 BpfTester.cpp:220] Test: packet #2 dst port hashing only result: Failed I0912 04:31:15.303587 3131 BpfTester.cpp:220] Test: gue ipv4 inner ipv4 outer packet result: Passed I0912 04:31:15.303613 3131 BpfTester.cpp:220] Test: gue ipv6 inner ipv6 outer packet result: Passed I0912 04:31:15.303651 3131 BpfTester.cpp:220] Test: gue ipv4 inner ipv6 outer packet result: Passed I0912 04:31:15.303678 3131 BpfTester.cpp:220] Test: QUIC: long header. Client Initial type. LRU miss result: Failed I0912 04:31:15.303707 3131 BpfTester.cpp:220] Test: QUIC: long header. 0-RTT Protected. CH. LRU hit. result: Failed I0912 04:31:15.303735 3131 BpfTester.cpp:220] Test: QUIC: long header. Handshake. v4 vip v6 real. Conn Id based. result: Failed I0912 04:31:15.303761 3131 BpfTester.cpp:220] Test: QUIC: long header. Retry. v4 vip v6 real. Conn Id based. result: Failed I0912 04:31:15.303786 3131 BpfTester.cpp:220] Test: QUIC: long header. client initial. v6 vip v6 real. LRU miss result: Failed I0912 04:31:15.303812 3131 BpfTester.cpp:220] Test: QUIC: short header. No connection id. CH. LRU hit result: Failed I0912 04:31:15.303839 3131 BpfTester.cpp:220] Test: QUIC: short header w/ connection id result: Failed I0912 04:31:15.303867 3131 BpfTester.cpp:220] Test: QUIC: short header w/ connection id but non-existing mapping result: Failed I0912 04:31:15.303892 3131 BpfTester.cpp:220] Test: QUIC: short header w/ conn id. host id = 0. CH. LRU hit result: Failed I0912 04:31:15.303918 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) + ToS in IPV4 result: Failed I0912 04:31:15.303946 3131 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) with ToS / tc set result: Failed I0912 04:31:15.303949 3131 katran_tester.cpp:257] Testing counter's sanity. Printing on errors only I0912 04:31:15.304035 3131 katran_tester.cpp:313] Testing of counters is complete E0912 04:31:15.304160 3131 KatranSimulator.cpp:168] src and dst must have same address family E0912 04:31:15.304165 3131 KatranSimulator.cpp:161] malformed src or dst ip address. src: aaaa dst: bbbb E0912 04:31:15.304169 3131 BpfLoader.cpp:104] Can't find prog with name: cls-hc I0912 04:31:15.304173 3131 katran_tester.cpp:179] Healthchecking not enabled. Skipping HC related tests E0912 04:31:15.307870 3131 BpfLoader.cpp:94] Can't find map w/ name: lpm_src_v4 E0912 04:31:15.307879 3131 BpfLoader.cpp:94] Can't find map w/ name: decap_dst E0912 04:31:15.307884 3131 BpfLoader.cpp:94] Can't find map w/ name: event_pipe E0912 04:31:15.307891 3131 BpfLoader.cpp:94] Can't find map w/ name: hc_pckt_srcs_map I0912 04:31:15.307900 3131 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:17 I0912 04:31:15.307905 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307911 3131 KatranLb.cpp:717] adding new vip: 10.200.1.1:80:6 I0912 04:31:15.307914 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307919 3131 KatranLb.cpp:717] adding new vip: 10.200.1.2:0:6 I0912 04:31:15.307922 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307926 3131 KatranLb.cpp:717] adding new vip: 10.200.1.4:0:6 I0912 04:31:15.307929 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307934 3131 KatranLb.cpp:821] modyfing vip: 10.200.1.4:0:6 I0912 04:31:15.307940 3131 KatranLb.cpp:717] adding new vip: 10.200.1.3:80:6 I0912 04:31:15.307943 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307950 3131 KatranLb.cpp:717] adding new vip: fc00:1::1:80:6 I0912 04:31:15.307955 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307960 3131 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.1 I0912 04:31:15.307965 3131 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.2 I0912 04:31:15.307968 3131 KatranLb.cpp:1456] trying to add already existing mapping for 10.0.0.3 I0912 04:31:15.307972 3131 KatranLb.cpp:1456] trying to add already existing mapping for fc00::1 I0912 04:31:15.307976 3131 KatranLb.cpp:1456] trying to add already existing mapping for fc00::2 I0912 04:31:15.307979 3131 KatranLb.cpp:1456] trying to add already existing mapping for fc00::3 I0912 04:31:15.307982 3131 KatranLb.cpp:717] adding new vip: 10.200.1.5:443:17 I0912 04:31:15.307986 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.307988 3131 KatranLb.cpp:821] modyfing vip: 10.200.1.5:443:17 I0912 04:31:15.307994 3131 KatranLb.cpp:717] adding new vip: fc00:1::2:443:17 I0912 04:31:15.307997 3131 KatranLb.cpp:725] trying to add already existing vip I0912 04:31:15.308001 3131 KatranLb.cpp:821] modyfing vip: fc00:1::2:443:17 ALL TESTS PASSED I0912 04:31:15.308081 3131 BpfTester.cpp:220] Test: packet to UDP based v4 VIP (and v4 real) result: Passed I0912 04:31:15.308329 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) result: Passed I0912 04:31:15.308414 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real; any dst ports). result: Passed I0912 04:31:15.308488 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v6 real) result: Passed I0912 04:31:15.308558 3131 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) result: Passed I0912 04:31:15.308648 3131 BpfTester.cpp:220] Test: v4 ICMP echo-request result: Passed I0912 04:31:15.308672 3131 BpfTester.cpp:220] Test: v6 ICMP echo-request result: Passed I0912 04:31:15.308696 3131 BpfTester.cpp:220] Test: v4 ICMP dest-unreachabe fragmentation-needed result: Passed I0912 04:31:15.308723 3131 BpfTester.cpp:220] Test: v6 ICMP packet-too-big result: Passed I0912 04:31:15.308750 3131 BpfTester.cpp:220] Test: drop of IPv4 packet w/ options result: Passed I0912 04:31:15.308773 3131 BpfTester.cpp:220] Test: drop of IPv4 fragmented packet result: Passed I0912 04:31:15.308799 3131 BpfTester.cpp:220] Test: drop of IPv6 fragmented packet result: Passed I0912 04:31:15.308822 3131 BpfTester.cpp:220] Test: pass of v4 packet with dst not equal to any configured VIP result: Passed I0912 04:31:15.308852 3131 BpfTester.cpp:220] Test: pass of v6 packet with dst not equal to any configured VIP result: Passed I0912 04:31:15.308881 3131 BpfTester.cpp:220] Test: pass of arp packet result: Passed I0912 04:31:15.308902 3131 BpfTester.cpp:220] Test: LRU hit result: Passed I0912 04:31:15.308929 3131 BpfTester.cpp:220] Test: packet #1 dst port hashing only result: Passed I0912 04:31:15.308954 3131 BpfTester.cpp:220] Test: packet #2 dst port hashing only result: Passed I0912 04:31:15.308977 3131 BpfTester.cpp:220] Test: gue ipv4 inner ipv4 outer packet result: Passed I0912 04:31:15.309006 3131 BpfTester.cpp:220] Test: gue ipv6 inner ipv6 outer packet result: Passed I0912 04:31:15.309032 3131 BpfTester.cpp:220] Test: gue ipv4 inner ipv6 outer packet result: Passed I0912 04:31:15.309060 3131 BpfTester.cpp:220] Test: QUIC: long header. Client Initial type. LRU miss result: Passed I0912 04:31:15.309085 3131 BpfTester.cpp:220] Test: QUIC: long header. 0-RTT Protected. CH. LRU hit. result: Passed I0912 04:31:15.309108 3131 BpfTester.cpp:220] Test: QUIC: long header. Handshake. v4 vip v6 real. Conn Id based. result: Passed I0912 04:31:15.309135 3131 BpfTester.cpp:220] Test: QUIC: long header. Retry. v4 vip v6 real. Conn Id based. result: Passed I0912 04:31:15.309167 3131 BpfTester.cpp:220] Test: QUIC: long header. client initial. v6 vip v6 real. LRU miss result: Passed I0912 04:31:15.309195 3131 BpfTester.cpp:220] Test: QUIC: short header. No connection id. CH. LRU hit result: Passed I0912 04:31:15.309217 3131 BpfTester.cpp:220] Test: QUIC: short header w/ connection id result: Passed I0912 04:31:15.309243 3131 BpfTester.cpp:220] Test: QUIC: short header w/ connection id but non-existing mapping result: Passed I0912 04:31:15.309267 3131 BpfTester.cpp:220] Test: QUIC: short header w/ conn id. host id = 0. CH. LRU hit result: Passed I0912 04:31:15.309290 3131 BpfTester.cpp:220] Test: packet to TCP based v4 VIP (and v4 real) + ToS in IPV4 result: Passed I0912 04:31:15.309319 3131 BpfTester.cpp:220] Test: packet to TCP based v6 VIP (and v6 real) with ToS / tc set result: Passed I0912 04:31:15.309324 3131 katran_tester.cpp:257] Testing counter's sanity. Printing on errors only I0912 04:31:15.309350 3131 katran_tester.cpp:261] per Vip counter is incorrect for vip:10.200.1.1 I0912 04:31:15.309361 3131 katran_tester.cpp:266] LRU counter is incorrect I0912 04:31:15.309371 3131 katran_tester.cpp:271] per pckt type LRU miss counter is incorrect I0912 04:31:15.309381 3131 katran_tester.cpp:276] LRU fallback counter is incorrect I0912 04:31:15.309391 3131 katran_tester.cpp:280] Counters for QUIC packets routed with CH: 10, with connection-id: 8 I0912 04:31:15.309394 3131 katran_tester.cpp:282] Counters for routing of QUIC packets is wrong. I0912 04:31:15.309406 3131 katran_tester.cpp:296] incorrect stats for real: 10.0.0.1 I0912 04:31:15.309410 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309418 3131 katran_tester.cpp:296] incorrect stats for real: 10.0.0.2 I0912 04:31:15.309422 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309429 3131 katran_tester.cpp:296] incorrect stats for real: 10.0.0.3 I0912 04:31:15.309432 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309442 3131 katran_tester.cpp:296] incorrect stats for real: fc00::1 I0912 04:31:15.309444 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309453 3131 katran_tester.cpp:296] incorrect stats for real: fc00::2 I0912 04:31:15.309455 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309463 3131 katran_tester.cpp:296] incorrect stats for real: fc00::3 I0912 04:31:15.309466 3131 katran_tester.cpp:297] Expected to be incorrect w/ non default build flags I0912 04:31:15.309469 3131 katran_tester.cpp:313] Testing of counters is complete E0912 04:31:15.309583 3131 KatranSimulator.cpp:168] src and dst must have same address family E0912 04:31:15.309588 3131 KatranSimulator.cpp:161] malformed src or dst ip address. src: aaaa dst: bbbb E0912 04:31:15.309595 3131 BpfLoader.cpp:104] Can't find prog with name: cls-hc I0912 04:31:15.309599 3131 katran_tester.cpp:179] Healthchecking not enabled. Skipping HC related tests ``` Pull Request resolved: #96 Reviewed By: xttjsn Differential Revision: D23674803 Pulled By: udippant fbshipit-source-id: 3e93c42f97e5559258d87fa9ba0e47d8d52f5349
facebookincubator · Sep 21, 2020 · d195c04 · d195c04
1 parent 83f01c5
commit d195c04
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Showing 15 changed files with 288 additions and 62 deletions.
diff --git a/build_bpf_modules_opensource.sh b/build_bpf_modules_opensource.sh
@@ -26,21 +26,25 @@ set -xeo pipefail
 usage() {
 cat 1>&2 <<EOF
 
-Usage ${0##*/} [-h|?] [-s SRC_DIR] [-b BUILD_DIR]
+Usage ${0##*/} [-h|?] [-s SRC_DIR] [-b BUILD_DIR] [-d DEFINES]
   -s SRC_DIR                     (optional): Path to source dir for katran
   -b BUILD_DIR                   (optional): Path to build dir for katran
+  -d DEFINES                     (optional): Specify custom defines for bpf program
   -h|?                                       Show this help message
 EOF
 }
 
-while getopts ":hb:s:m" arg; do
+while getopts ":hb:s:d:m" arg; do
   case $arg in
     b)
       BUILD_DIR="${OPTARG}"
       ;;
     s)
       SRC_DIR="${OPTARG}"
       ;;
+    d)
+      DEFINES="${OPTARG}"
+      ;;
     h) # Display help.
       usage
       exit 0
@@ -74,6 +78,6 @@ cp -r "${SRC_DIR}/katran/lib/bpf" "${BUILD_DIR}/deps/bpfprog/"
 cp -r "${SRC_DIR}/katran/decap/bpf" "${BUILD_DIR}/deps/bpfprog/"
 cp "${SRC_DIR}"/katran/lib/linux_includes/* "${BUILD_DIR}/deps/bpfprog/include/"
 cd "${BUILD_DIR}/deps/bpfprog" && LD_LIBRARY_PATH="${CLANG_PATH}/lib" make \
-  EXTRA_CFLAGS="$*" \
+  EXTRA_CFLAGS="${DEFINES}" \
   LLC="${CLANG_PATH}/bin/llc" CLANG="${CLANG_PATH}/bin/clang"
 echo "BPF BUILD COMPLITED"
diff --git a/katran/lib/BpfAdapter.cpp b/katran/lib/BpfAdapter.cpp
@@ -241,6 +241,12 @@ int BpfAdapter::loadBpfProg(
   return loader_.loadBpfFile(bpf_prog, type, use_names);
 }
 
+int BpfAdapter::reloadBpfProg(
+    const std::string& bpf_prog,
+    const bpf_prog_type type) {
+  return loader_.reloadBpfFromFile(bpf_prog, type);
+}
+
 int BpfAdapter::loadBpfProg(
     char* buf,
     int buf_size,

diff --git a/katran/lib/BpfAdapter.h b/katran/lib/BpfAdapter.h
@@ -78,6 +78,20 @@ class BpfAdapter {
       const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC,
       bool use_names = false);
 
+  /**
+   * @param string bpf_prog path to bpf program
+   * @param bpf_prog_type type of bpf prog to load
+   * @return int result 0 in case of success, other val otherwise
+   *
+   * helper function to reload bpf program into the kernel
+   * loader could either deduct type from prog's name
+   * (supported xdp- and cls- prefixes) or by using option
+   * bpf_prog_type hint
+   */
+  int reloadBpfProg(
+      const std::string& bpf_prog,
+      const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC);
+
   /**
    * @param char* ptr to buffer with bpf's elf object
    * @param int size of the buffer

diff --git a/katran/lib/BpfLoader.cpp b/katran/lib/BpfLoader.cpp
@@ -39,7 +39,7 @@ ::bpf_prog_type normalizeBpfProgType(
   if (type != BPF_PROG_TYPE_UNSPEC) {
     return type;
   }
-  std::string prog_name(::bpf_program__title(prog, false));
+  std::string prog_name(::bpf_program__section_name(prog));
   auto prefix = prog_name.substr(kStart, kPrefixLen);
   if (prefix == "xdp") {
     VLOG(2) << "prog " << prog_name << " type: XDP";
@@ -135,6 +135,16 @@ int BpfLoader::loadBpfFile(
   return loadBpfObject(obj, path, type);
 }
 
+int BpfLoader::reloadBpfFromFile(
+    const std::string& path,
+    const bpf_prog_type type) {
+  auto obj = ::bpf_object__open(path.c_str());
+  if (obj == nullptr) {
+    return kError;
+  }
+  return reloadBpfObject(obj, path, type);
+}
+
 int BpfLoader::loadBpfFromBuffer(
     char* buf,
     int buf_size,
@@ -147,6 +157,101 @@ int BpfLoader::loadBpfFromBuffer(
   return loadBpfObject(obj, "buffer", type);
 }
 
+int BpfLoader::reloadBpfObject(
+    ::bpf_object* obj,
+    const std::string& name,
+    const bpf_prog_type type) {
+  ::bpf_program* prog;
+  ::bpf_map* map;
+
+  bpf_object__for_each_program(prog, obj) {
+    // reload bpf program only if we have loaded it already. we distinct bpf
+    // programs by their name
+    if (progs_.find(::bpf_program__section_name(prog)) == progs_.end()) {
+      LOG(ERROR) << "trying to reload not yet loaded program: "
+                 << ::bpf_program__section_name(prog);
+      return closeBpfObject(obj);
+    }
+    auto prog_type = normalizeBpfProgType(prog, type);
+    ::bpf_program__set_type(prog, prog_type);
+  }
+
+  bpf_map__for_each(map, obj) {
+    auto map_name = ::bpf_map__name(map);
+    auto shared_map_iter = sharedMaps_.find(map_name);
+    if (shared_map_iter != sharedMaps_.end()) {
+      VLOG(2) << "shared map found w/ a name: " << shared_map_iter->first
+              << " fd: " << shared_map_iter->second;
+      if (::bpf_map__reuse_fd(map, shared_map_iter->second)) {
+        LOG(ERROR) << "error while trying to set fd of shared map: "
+                   << shared_map_iter->first;
+        return closeBpfObject(obj);
+      }
+      continue;
+    }
+
+    auto map_iter = maps_.find(map_name);
+    if (map_iter != maps_.end()) {
+      // we would reuse already loaded map. if they were not explicitly added as
+      // shared maps we would make them such implicitly
+      VLOG(2) << "map w/ a name: " << map_iter->first
+              << " found. fd: " << map_iter->second << " Making it shared";
+      if (updateSharedMap(map_name, map_iter->second)) {
+        LOG(ERROR) << "Error while trying to update shared maps";
+        return closeBpfObject(obj);
+      }
+      if (::bpf_map__reuse_fd(map, map_iter->second)) {
+        LOG(ERROR)
+            << "error while trying to reuse fd of a map while reloading bpf program: "
+            << map_iter->first;
+        return closeBpfObject(obj);
+      }
+      continue;
+    }
+
+    auto inner_map_iter = innerMapsProto_.find(map_name);
+    if (inner_map_iter != innerMapsProto_.end()) {
+      VLOG(2) << "setting inner id for map-in-map: " << inner_map_iter->first
+              << " fd: " << inner_map_iter->second;
+      if (bpf_map__set_inner_map_fd(map, inner_map_iter->second)) {
+        LOG(ERROR) << "error while trying to set inner map fd for: "
+                   << inner_map_iter->first
+                   << " fd: " << inner_map_iter->second;
+        return closeBpfObject(obj);
+      }
+    }
+  }
+
+  if (::bpf_object__load(obj)) {
+    LOG(ERROR) << "error while trying to load bpf object: " << name;
+    return closeBpfObject(obj);
+  }
+
+  bpf_object__for_each_program(prog, obj) {
+    // close old bpf program and (as we successfully reloaded it) and override
+    // fd with a new one
+    auto prog_name = ::bpf_program__section_name(prog);
+    VLOG(4) << "closing old bpf program w/ name: " << prog_name;
+    auto old_fd = progs_[prog_name];
+    ::close(old_fd);
+    VLOG(4) << "adding bpf program: " << prog_name
+            << " with fd: " << ::bpf_program__fd(prog);
+    progs_[prog_name] = ::bpf_program__fd(prog);
+  }
+
+  bpf_map__for_each(map, obj) {
+    auto map_name = bpf_map__name(map);
+    auto map_iter = maps_.find(map_name);
+    if (map_iter == maps_.end()) {
+      VLOG(4) << "adding bpf map: " << map_name
+              << " with fd: " << ::bpf_map__fd(map);
+      maps_[map_name] = bpf_map__fd(map);
+    }
+  }
+  bpfObjects_[name] = obj;
+  return kSuccess;
+}
+
 int BpfLoader::loadBpfObject(
     ::bpf_object* obj,
     const std::string& name,
@@ -160,9 +265,9 @@ int BpfLoader::loadBpfObject(
   ::bpf_map* map;
 
   bpf_object__for_each_program(prog, obj) {
-    if (progs_.find(::bpf_program__title(prog, false)) != progs_.end()) {
+    if (progs_.find(::bpf_program__section_name(prog)) != progs_.end()) {
       LOG(ERROR) << "bpf's program name collision: "
-                 << ::bpf_program__title(prog, false);
+                 << ::bpf_program__section_name(prog);
       return closeBpfObject(obj);
     }
     auto prog_type = normalizeBpfProgType(prog, type);
@@ -204,9 +309,9 @@ int BpfLoader::loadBpfObject(
   }
 
   bpf_object__for_each_program(prog, obj) {
-    VLOG(4) << "adding bpf program: " << ::bpf_program__title(prog, false)
+    VLOG(4) << "adding bpf program: " << ::bpf_program__section_name(prog)
             << " with fd: " << ::bpf_program__fd(prog);
-    progs_[::bpf_program__title(prog, false)] = ::bpf_program__fd(prog);
+    progs_[::bpf_program__section_name(prog)] = ::bpf_program__fd(prog);
   }
 
   bpf_map__for_each(map, obj) {

diff --git a/katran/lib/BpfLoader.h b/katran/lib/BpfLoader.h
@@ -68,6 +68,19 @@ class BpfLoader {
       const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC,
       bool use_names = false);
 
+  /**
+   * @param string path to bpf object file
+   * @param bpf_prog_type type of bpf program to load.
+   * @return int 0 on success
+   *
+   * helper function to reload bpf program. for XDP and TC bpf programs we could
+   * deduce the type from program's name (if they starts with xdp or cls)
+   * could throw if object file is malformed
+   */
+  int reloadBpfFromFile(
+      const std::string& path,
+      const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC);
+
   /**
    * @param string name of the map
    * @return int negative on failure, map's fd on success
@@ -111,6 +124,14 @@ class BpfLoader {
       const std::string& name,
       const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC);
 
+  /**
+   * helper function to reload bpf object
+   */
+  int reloadBpfObject(
+      ::bpf_object* obj,
+      const std::string& name,
+      const bpf_prog_type type = BPF_PROG_TYPE_UNSPEC);
+
   /**
    * helper function to close bpf object and return error.
    */

diff --git a/katran/lib/KatranLb.cpp b/katran/lib/KatranLb.cpp
@@ -186,7 +186,7 @@ void KatranLb::initialSanityChecking() {
     maps.push_back("ch_rings");
     maps.push_back("reals");
     maps.push_back("stats");
-    maps.push_back("lru_maps_mapping");
+    maps.push_back("lru_mapping");
     maps.push_back("quic_mapping");
 
     res = getKatranProgFd();
@@ -290,7 +290,7 @@ void KatranLb::initLrus() {
       throw std::runtime_error("can't create prototype map for test lru");
     }
   }
-  res = bpfAdapter_.setInnerMapPrototype("lru_maps_mapping", lru_proto_fd);
+  res = bpfAdapter_.setInnerMapPrototype("lru_mapping", lru_proto_fd);
   if (res < 0) {
     throw std::runtime_error(folly::sformat(
         "can't update inner_maps_fds w/ prototype for main lru, error: {}",
@@ -307,7 +307,7 @@ void KatranLb::attachLrus() {
     key = core;
     map_fd = lruMapsFd_[core];
     res = bpfAdapter_.bpfUpdateMap(
-        bpfAdapter_.getMapFdByName("lru_maps_mapping"), &key, &map_fd);
+        bpfAdapter_.getMapFdByName("lru_mapping"), &key, &map_fd);
     if (res < 0) {
       throw std::runtime_error(folly::sformat(
           "can't attach lru to forwarding core, error: {}",
@@ -426,10 +426,9 @@ void KatranLb::enableRecirculation() {
   uint32_t key = kRecirculationIndex;
   int balancer_fd = getKatranProgFd();
   auto res = bpfAdapter_.bpfUpdateMap(
-      bpfAdapter_.getMapFdByName("katran_subprograms"), &key, &balancer_fd);
+      bpfAdapter_.getMapFdByName("subprograms"), &key, &balancer_fd);
   if (res < 0) {
-    throw std::runtime_error(
-        "can not update katran_subprograms for recirculation");
+    throw std::runtime_error("can not update subprograms for recirculation");
   }
 }
 
@@ -543,13 +542,52 @@ void KatranLb::loadBpfProgs() {
   progsLoaded_ = true;
   if (!config_.disableForwarding && features_.introspection) {
     startIntrospectionRoutines();
+    introspectionStarted_ = true;
   }
 
   if (!config_.disableForwarding) {
     attachLrus();
   }
 }
 
+bool KatranLb::reloadBalancerProg(
+    const std::string& path,
+    folly::Optional<KatranConfig> config) {
+  int res;
+  if (config_.disableForwarding) {
+    return false;
+  }
+
+  res = bpfAdapter_.reloadBpfProg(path);
+  if (res) {
+    return false;
+  }
+
+  if (config.has_value()) {
+    config_ = *config;
+  }
+
+  config_.balancerProgPath = path;
+
+  initialSanityChecking();
+  featureDiscovering();
+
+  if (features_.gueEncap) {
+    setupGueEnvironment();
+  }
+
+  if (features_.inlineDecap) {
+    enableRecirculation();
+  }
+
+  if (features_.introspection && !introspectionStarted_) {
+    startIntrospectionRoutines();
+    introspectionStarted_ = true;
+  }
+  progsReloaded_ = true;
+  return true;
+}
+
 void KatranLb::attachBpfProgs() {
   if (!progsLoaded_) {
     throw std::invalid_argument("failed to attach bpf prog: prog not loaded");
@@ -581,7 +619,7 @@ void KatranLb::attachBpfProgs() {
     }
   }
 
-  if (config_.enableHc) {
+  if (config_.enableHc && !progsReloaded_) {
     // attaching healthchecking bpf prog.
     auto hc_fd = getHealthcheckerProgFd();
     res = bpfAdapter_.addTcBpfFilter(

diff --git a/katran/lib/KatranLb.h b/katran/lib/KatranLb.h
@@ -98,6 +98,14 @@ class KatranLb {
    */
   void loadBpfProgs();
 
+  /**
+   * @return true on success
+   *
+   * helper function to reload balancer program in runtime
+   * could throw std::invalid_argument if reload fails.
+   */
+  bool reloadBalancerProg(const std::string& path, folly::Optional<KatranConfig> config = folly::none);
+
   /**
    * helper function to attach bpf program (e.g. to rootlet array,
    * driver or into tc qdisc)
@@ -823,6 +831,16 @@ class KatranLb {
    * userspace library stats
    */
   KatranLbStats lbStats_;
+
+  /**
+   * flag which indicates that introspection routines already started
+   */
+  bool introspectionStarted_{false};
+
+  /**
+   * flag which indicates that bpf program was reloaded
+   */
+  bool progsReloaded_{false};
 };
 
 } // namespace katran