April 2022 - Bird-users - Mailing Lists

[PATCH] Bus error on ARMv7 when using OSPF
by Matthew Reeve 18 Dec '24

18 Dec '24

Hi, when using bird 2.0.8 on openwrt 21.02 (and other versions) on a Netgear R7800 router, if the OSPF protocol is used, either v2 or v3, bird immediately crashes on startup with: Fri Jun 11 14:41:11 2021 daemon.info bird: Started Fri Jun 11 14:41:11 2021 kern.err kernel: [ 3500.853248] Alignment trap: not handling instruction f44c0a1f at [<00035848>] Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.853283] 8<--- cut here --- Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.859363] Unhandled fault: alignment exception (0x801) at 0x007e0624 Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.862443] pgd = 0bbef4fd Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.868821] [007e0624] *pgd=5d6ca835, *pte=5c40b75f, *ppte=5c40bc7f This router uses an ARMv7 processor and the issue seems to be to do with memory alignment issues. I've debugged it and traced it to an access to the top_hash_entry struct. I've found that if I add the PACKED macro to the struct definition then it fixes the problem, as per this patch: --- a/proto/ospf/topology.h +++ b/proto/ospf/topology.h @@ -41,7 +41,7 @@ struct top_hash_entry u8 mode; /* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/ u8 nhs_reuse; /* Whether nhs nodes can be reused during merging. See a note in rt.c:add_cand() */ -}; +} PACKED; /* Prevents ospf_hash_find() to ignore the entry, for p->lsrqh and p->lsrth */ Thanks.

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logging via udp
by Alexander Zubkov 13 Dec '23

13 Dec '23

Hello, Made some dirty patch for myself to allow bird to send logs via udp. But it may be useful not only for me, so posting it here. It could be useful when server experiencing high IO-load. As syslog and file operations in bird are blocking, it can be blocked on writing to it for indefinite time, which could lead to various problems like protocol timeouts. So udp logging comes in handy here. The tradeoff is that we can miss some logs if they are not processed in time. You can specify udp log destination like that: log udp [host IP|"hostname"] [port NUMBER|"portname"] ... By default it uses destination ip 127.0.0.1 and port 514. There are some constraints like not much error handling. And this destination replaces file destination, i.e. you can not use those simultaneously and it may leak descriptors and some memory probably if both are specified. It also makes a new socket every time configuration is reloaded even if there is no change in options, but this is not a great deal.

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BIRD show bgp summary for cli
by Roman Bulakh 14 Jun '23

14 Jun '23

Hi, we use BIRD in our environment, and it would be very nice to have some command like `show bgp summary` in juniper. This command show information about peer IP, peer AS, last update, prefixes received/best/exported and last state. Example: bird> show bgp summary Peer AS Last state change Prfx rcvd/best/export State X.X.X.X asXXXX 2021-01-27 6786/6785/109000 Established Y.Y.Y.Y asYYYY 2020-12-16 0/0/0 Passive BGP Error: Hold timer expired The are patch created for BIRD 1.3.4 and 1.3.6, but it would be good to have this in upstream software, without rebuilding and patching. as I understand it, no functionality should be affected by these changes, this is only a visual update for cli. Old patches describes at pages: https://marc.info/?l=bird-users&m=132155489919052&w=2 http://trubka.network.cz/pipermail/bird-users/attachments/20120228/a1499be7… https://bird-users.network.narkive.com/Px6EH3yl/bird-1-3-6-show-bgp-summary…

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Adding more then one bgp community at once
by Борис Коваленко 05 May '23

05 May '23

Hello! Is this possible to add many communites at once? bgp_community.add([(1,1), (1,2)]) is wrong "Setting clist attribute to non-clist value" Regards, Boris -- С уважением, Борис Коваленко

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Expiration for ROA tables until when the VRP is valid?
by Robert Scheck 07 Mar '23

07 Mar '23

Hello all, rpki-client recently implemented the "expires" instruction for roa-sets that OpenBGPD provides [1][2]. As of writing, BIRD does not seem to have something similar...any chance for it? From my understanding this only applies to included ROA files with VRP, not to RTR. [1] https://man.openbsd.org/bgpd.conf#roa-set [2] https://github.com/rpki-client/rpki-client-openbsd/commit/7bf63da6ec80f37bd… Kind regards Robert Scheck

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[PATCH] feature to keep protocol's state while configuring
by Alexander Zubkov 29 Jan '23

29 Jan '23

Hello. I have created a patch (attached) with new protocol option: disabled keep on|off. To keep the protocol's state while loading new config. It is useful when protocols disabled manually in the runtime, but we want to keep that state when loading new config. Patch is attached. I have made it against the current int-new branch.

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[PATCH] krt: Dump routing tables separetely on linux to avoid congestion
by Daniel Gröber 24 Jul '22

24 Jul '22

When dumping the routing table bird currently doesn't set the rtm_table netlink field to select any particular one but rather wants to get all at once. This can be problematic when multiple routing daemons are running on a system as the kernel's route modification performance goes down drasticly (by a factor of 20-200ish) when the table is being modified while it's being dumped. To avoid this situation we make bird do dumps on a per-kernel-table basis. This then allows the administrator to have multiple routing daemons use different kernel tables which sidesteps the problem. See also this discussion on the babel-users mailing list: https://alioth-lists.debian.net/pipermail/babel-users/2022-April/003902.html --- sysdep/cf/linux.h | 2 +- sysdep/linux/netlink.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/sysdep/cf/linux.h b/sysdep/cf/linux.h index 047d3764..d6211d16 100644 --- a/sysdep/cf/linux.h +++ b/sysdep/cf/linux.h @@ -9,7 +9,7 @@ #define CONFIG_AUTO_ROUTES #define CONFIG_SELF_CONSCIOUS #define CONFIG_MULTIPLE_TABLES -#define CONFIG_ALL_TABLES_AT_ONCE +#undef CONFIG_ALL_TABLES_AT_ONCE #define CONFIG_IP6_SADR_KERNEL #define CONFIG_MC_PROPER_SRC diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c index 29b744cb..003b7939 100644 --- a/sysdep/linux/netlink.c +++ b/sysdep/linux/netlink.c @@ -256,7 +256,7 @@ nl_request_dump_addr(int af) } static void -nl_request_dump_route(int af) +nl_request_dump_route(int af, int table_id) { struct { struct nlmsghdr nh; @@ -267,6 +267,7 @@ nl_request_dump_route(int af) .nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP, .nh.nlmsg_seq = ++(nl_scan.seq), .rtm.rtm_family = af, + .rtm.rtm_table = table_id, }; send(nl_scan.fd, &req, sizeof(req), 0); @@ -1976,13 +1977,13 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h) } void -krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */ +krt_do_scan(struct krt_proto *p) { struct nlmsghdr *h; struct nl_parse_state s; nl_parse_begin(&s, 1); - nl_request_dump_route(AF_UNSPEC); + nl_request_dump_route(AF_UNSPEC, KRT_CF->sys.table_id); while (h = nl_get_scan()) if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE) nl_parse_route(&s, h); -- 2.30.2

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BIRD 3.0-alpha0
by Ondrej Filip 11 Jul '22

11 Jul '22

Dear BURD users, We have something special for you today. We're releasing a multi-threaded BIRD version 3.0-alpha0 for public testing. Protocols BGP, RPKI and Pipe got their own channels which promises faster convergence and better usage of system resources. Version 3.0-alpha0 is based on the previous 2.0.8 version and some enhancements from 2.0.9 will make it into the multi-threaded branch later on. There is also a blogpost about performance comparison we have recently done between 3.0-alpha0 and 2.0.8 (the previous single-threaded version) and you can read there also other articles about the multi-threaded version. We do not recommend running this version in production setups, yet we deeply appreciate any bugreports, including memory footprint problems. You can download the tgz package at the following URLs: https://bird.network.cz/?download&tdir=3.0pre/ ftp://bird.network.cz/pub/bird/3.0pre/ Main credits goes to Maria! Thank you! Ondrej Version 3.0-alpha0 (2022-02-07) o Removal of fixed protocol-specific route attributes o Asynchronous route export o Explicit table import / export hooks o Partially lockless route attribute cache o Thread-safe resource management o Thread-safe interface notifications o Thread-safe protocol API o Adoption of BFD IO loop for general use o Parallel Pipe protocol o Parallel RPKI protocol o Parallel BGP protocol o Lots of refactoring o Bugfixes and improvements as they came along

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Scaling BFD support
by Douglas Fischer 24 Jun '22

24 Jun '22

The question raised by colleague Irene reminded me of a topic that may or may not be the focus of BIRD's development. I imagine that the biggest supporters of SMP/Multi-Core/Thread-Safe evolution on BIRD are Operators of Route-Servers of large IXPs, and operators of large-scale Route-Reflectors. Although BFD has its greatest use in the transport network and Underlay, it is increasingly common to see the use of BFD in BGP Internet. I'm personally overly excited about what BIRD version 3 is demonstrating in terms of vertical scalability. But I keep imagining that, even having scalability in the BGP engine, it is almost prohibitive to use BFD in a scenario with a thousand BGP Peers. Is there any view from the IBRD development team for this matter? Or even... Is there any open project focused on BFD that can address this? And going a little further... In a quick Brainstorming... What would be the techniques that could help a Route-Server or Route-Reflector with a thousand BGP Peers to also support a thousand BFD sessions effectively and efficiently? Perhaps resort to some hardware-based off-loading method? Would eBPF help this in any way? -- Douglas Fernando Fischer Engº de Controle e Automação

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RFT: Babel RTT extension in Bird
by Toke Høiland-Jørgensen 12 May '22

12 May '22

Hi everyone I've implemented the Babel RTT extension specified in draft-ietf-babel-rtt-extension in Bird. I've tested that it talks to babeld on a single link and that the two implementations agree on each others' (smoothed) RTT values. However, I'd like to subject the code to some more tortured testing before submitting it to upstream Bird. So I'm sending this note as a request for testing. The code currently lives here: https://github.com/tohojo/bird/tree/babel-rtt-01 To compile it, do: git clone -b babel-rtt-01 https://github.com/tohojo/bird cd bird && autoreconf && ./configure && make To run it, create a config file enabling the RTT extension; the simplest way to do this is to set the interface type to 'tunnel'. A sample minimal config is included below (just change the interface name from "veth0"). Save this and run Bird in the foreground in debug mode like: ./bird -c sample.conf -d Any feedback (successes or failures) greatly appreciated! -Toke debug protocols all; router id 1.2.3.4; ipv4 table master4; ipv6 table master6; protocol device { scan time 10; } protocol kernel kernel4 { learn; ipv4 { export all; import all; }; } protocol kernel kernel6 { learn; ipv6 { import all; import all; }; } protocol babel { ipv4 { import all; export all; }; ipv6 { import all; export all; }; interface "veth0" { type tunnel; }; }

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