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how to change ospf interface cost dynamically
by d tbsky 30 Aug '17

30 Aug '17

hi: I have two ospf interfaces between two routers. sometimes I want to use one of the interfaces to transfer data, and sometimes I want to use another. I think I can change configuration of interface cost and issue bird reload every time I need to switch interface. but I wonder if there is smarter way. any possibility I can change some interface parameters by linux system commands, so bird would change ospf cost dynamically? or can I tell bird to change interface cost dynamically? thanks a lot for suggestion!

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[RFC] filter profiling
by Lennert Buytenhek 29 Aug '17

29 Aug '17

Hi! Attached is a crude hack to allow profiling filter processing. When you're done implementing all of your filter logic and are wondering exactly why it now takes bird so friggin' long to propagate routes while sitting for several minutes at 100% CPU on the anemic embedded CPUs you're trying to run it on, tools like 'perf' aren't too useful, since they'll just tell you that all CPU time is being spent in interpret() or related functions and won't tell you which filter language statements are responsible for how much of the CPU time. The attached patch is a very rough way of attempting to enable you to figure out what's eating your cycles. The basic idea is that it sets up a SIGUSR2 handler that will write to stderr the config file name and line currently being processed, and the prefix being operated on if there is one. You can then send bird SIGUSR2 in a tight loop whenever it seems to be spinning at 100% CPU and the resulting output will give you a clue of what's going on. This is a very dirty hack, and it does some things that probably aren't entirely safe, like calling into snprintf from a signal handler, and it shouldn't be merged in this form, but for our purposes, it seems to be working well, and seems to be able to provide useful insights into some of our self-inflicted filter performance problems. Feedback appreciated! (Better ideas also appreciated. :D) Cheers, Lennert diff --git a/filter/f-util.c b/filter/f-util.c index def2b248..452dbcb2 100644 --- a/filter/f-util.c +++ b/filter/f-util.c @@ -20,6 +20,7 @@ f_new_inst(void) ret->code = ret->aux = 0; ret->arg1 = ret->arg2 = ret->next = NULL; ret->lineno = ifs->lino; + ret->file_name = ifs->file_name; return ret; } diff --git a/filter/filter.c b/filter/filter.c index f18970e0..d58c6cb4 100644 --- a/filter/filter.c +++ b/filter/filter.c @@ -33,6 +33,10 @@ #undef LOCAL_DEBUG +#include <stdio.h> +#include <signal.h> +#include <unistd.h> + #include "nest/bird.h" #include "lib/lists.h" #include "lib/resource.h" @@ -551,7 +555,7 @@ val_format(struct f_val v, buffer *buf) } } -static struct rte **f_rte; +static struct rte ** volatile f_rte; static struct rta *f_old_rta; static struct ea_list **f_tmp_attrs; static struct linpool *f_pool; @@ -630,8 +634,10 @@ static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS; * &f_val structures are copied around, so there are no problems with * memory managment. */ +static struct f_val interpret(struct f_inst *what); + static struct f_val -interpret(struct f_inst *what) +__interpret(struct f_inst *what) { struct symbol *sym; struct f_val v1, v2, res, *vp; @@ -1515,6 +1521,70 @@ interpret(struct f_inst *what) return res; } +#define barrier() __asm__ __volatile__("": : :"memory") + +static char *file_name; +static int lino; + +static struct f_val +interpret(struct f_inst *what) +{ + struct f_val ret; + + if (what != NULL) { + lino = what->lineno; + barrier(); + file_name = what->file_name; + } + + ret = __interpret(what); + + if (what != NULL) { + file_name = NULL; + barrier(); + lino = -1; + } + + return ret; +} + +static void handle_sigusr2(int sig UNUSED) +{ + char prefix[64]; + char buf[1024]; + + if (file_name == NULL) { +// write(2, "not interpreting an f_inst right now\n", 37); + return; + } + + prefix[0] = 0; +#ifndef IPV6 + if (f_rte != NULL) { + struct fib_node *n = &(*f_rte)->net->n; + ip_addr addr = n->prefix; + + snprintf(prefix, sizeof(prefix), "%d.%d.%d.%d/%d", + (addr >> 24) & 0xff, (addr >> 16) & 0xff, + (addr >> 8) & 0xff, addr & 0xff, n->pxlen); + } +#endif + + snprintf(buf, sizeof(buf), "%s:%d %s\n", file_name, lino, prefix); + + write(2, buf, strlen(buf)); +} + +void filter_profile_init(void) +{ + struct sigaction sa; + + bzero(&sa, sizeof(sa)); + sa.sa_handler = handle_sigusr2; + sa.sa_flags = SA_RESTART; + sigaction(SIGUSR2, &sa, NULL); +} + #undef ARG #define ARG(x,y) \ if (!i_same(f1->y, f2->y)) \ @@ -1720,6 +1790,7 @@ f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struc rta_free(f_old_rta); } + f_rte = NULL; if (res.type != T_RETURN) { log_rl(&rl_runtime_err, L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name); @@ -1747,6 +1818,8 @@ f_eval_rte(struct f_inst *expr, struct rte **rte, struct linpool *tmp_pool) /* Note that in this function we assume that rte->attrs is private / uncached */ struct f_val res = interpret(expr); + f_rte = NULL; + /* Hack to include EAF_TEMP attributes to the main list */ (*rte)->attrs->eattrs = ea_append(tmp_attrs, (*rte)->attrs->eattrs); diff --git a/filter/filter.h b/filter/filter.h index 049ceb76..4349fdb3 100644 --- a/filter/filter.h +++ b/filter/filter.h @@ -26,6 +26,7 @@ struct f_inst { /* Instruction */ int i; void *p; } a2; + char *file_name; int lineno; }; diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c index 8aa19fce..4ef84196 100644 --- a/sysdep/unix/main.c +++ b/sysdep/unix/main.c @@ -870,6 +870,7 @@ main(int argc, char **argv) write_pid_file(); signal_init(); + filter_profile_init(); config_commit(conf, RECONFIG_HARD, 0);

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{ } in BGP.as_path
by Mikhail Mayorov 25 Aug '17

25 Aug '17

Hi all! What is mean '{}' in as_path? PAPA.rndpapa bird # birdcl show route where net = '216.126.32.0/20' all BIRD 1.6.3 ready. 216.126.32.0/20 via 95.174.97.33 on vlan8 [bird_ipv4 25.08.2017 17:54:37] * (100/0) [i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 9002 3356 13703 { 20340 } BGP.next_hop: 95.174.97.33 BGP.med: 999 BGP.local_pref: 100 BGP.aggregator: 208.52.178.233 AS13703 BGP.community: (9002,9002) (9002,64657) (49037,0) (49037,10001) -- Regards, Mikhail V. Majorov

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IPv6 BIRD filters
by Marek Królikowski 25 Aug '17

25 Aug '17

Hello Guys, Anyone create maybe a good filters for BIRD IPv6 upstreams? I just add this to my import filter: import filter { if bgp_path.len > 49 then reject; if (net.len < 16) || (net.len > 48) then reject; accept; }; But i saw i get strange routing: root@it-bgp:~# birdc6 show route 2404:1710::/28 BIRD 1.6.3 ready. 2404:1710::/28 via 2a02:XXXX:XXXX:1 on eth0 [Italy 13:52:47 from 2a02:XXXX:XXXX::2] * (100/?) [AS65332i] Anyone got any good filter to block something like this? Best Regards Marek

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IPv6 prefix set
by Damien Clabaut 22 Aug '17

22 Aug '17

Hello, I am trying to use prefix-set inside a filter in IPv6: filter my_filter6 prefix set my_prefixset6; { my_prefixset6 = [aaaa:bbbb:100:ff::/56]; if (net ~ my_prefixset6) then { bgp_local_pref = 104; } accept; } But I get the following error: birdc6 BIRD 1.6.3 ready. bird> configure check Invalid network prefix: aaaa:bbbb:100:ff::/56. Am I doing anything wrong ? Also, the prefix set is dynamically updated via script, is there a correct way to handle the case where it is empty ? Or should the scripts comment the definition of prefix-set and the complete "if" block ? Regards, -- Damien Clabaut R&D vRouter ovh.qc.ca

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Propagate default route when BGP session is up
by Robert Sander 22 Aug '17

22 Aug '17

Hi, how do I propagate a default route into OSPF when a specific BGP session is up and not propagate it when it is down? Currently I have these config snippets: protocol static static_default { preference 10; route 0.0.0.0/0 unreachable; } function export_ospf() { if source = RTS_BGP then { return false; } if proto = "static_bgp" then { return false; } return true; } protocol ospf { rfc1583compat on; import all; export filter { if export_ospf() then accept; reject; }; area 0 { interface "ospf" { cost 10; hello 10; retransmit 5; dead 45; }; }; } protocol bgp ispa1 { description "ISP A1"; import all; export filter { if proto = "static_bgp" then accept; reject; }; local 1.2.3.6 as 1; neighbor 1.2.3.5 as 2; password "xyz"; } I can manually "birdc disable static_default" to not propagate the default route but how can this be automated when the BGP session to ispa1 is down? Regards -- Robert Sander Heinlein Support GmbH Schwedter Str. 8/9b, 10119 Berlin http://www.heinlein-support.de Tel: 030 / 405051-43 Fax: 030 / 405051-19 Zwangsangaben lt. §35a GmbHG: HRB 93818 B / Amtsgericht Berlin-Charlottenburg, Geschäftsführer: Peer Heinlein -- Sitz: Berlin

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bgp_path.first
by nixx 22 Aug '17

22 Aug '17

Hello. i'm trying to configure bird for working with uplinks and downlinks with this example: https://gitlab.labs.nic.cz/labs/bird/wikis/BGP_filtering i'm using truncated function: function rt_export() { if proto = "static_bgp" then return true; if source != RTS_BGP then return false; return bgp_path.first ~ [ downlink1AS, downlink2AS ]; } But this incorrectly works - bird trying to export my full-view to uplink. Then, when i changed to if ( bgp_path.len = 2 ) && ( bgp_path.first = myAS ) then return bgp_path ~ [ downlink1AS, downlink2AS ]; ...it works. What i'm (or my bird) doing wrong? Or maybe this example is not correct?

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Strange peer connection/TCP listen behaviour
by Rhosyn 22 Aug '17

22 Aug '17

Hi all, I have three nodes that mesh with each other internally and also peer externally to transits, I’m seeing weird behaviour on two nodes. All nodes are running FreeBSD 11.1, with bird6 1.6.3. Node A happily connects to B and C without issue, likewise B and C can initiate and peer with A in kind without issue. However B and C refuse to connect and continually send SYN packets to each other. The packets are arriving over IPIP/gif tunnels on top of IPSec transport mode; running netcat to listen on 179 works also works. Both B and C only connect whenever the transit peer they are connected to, is disabled/restarted. At this point bird on B and C see the SYN packets, and connect as expected. It does not matter which node I drop transit from, providing it happens to be B or C. I thought this might be routing issues but all three nodes have static routes and I also filtered all incoming routes from transit just in case but no joy. Below is a copy of the debug from bird, at the moment I disable transit (the output is from C and the same/similar output is seen on B); 2017-08-21 22:39:08 <TRACE> coes: Connecting to fd93:2559:f2ef::9 from local address fd93:2559:f2ef::a 2017-08-21 22:39:08 <TRACE> coes: Connecting to fd93:2559:f2ef::9 from local address fd93:2559:f2ef::a 2017-08-21 22:39:10 <TRACE> coes: Connecting to fd93:2559:f2ef::9 from local address fd93:2559:f2ef::a 2017-08-21 22:39:10 <TRACE> coes: Connecting to fd93:2559:f2ef::9 from local address fd93:2559:f2ef::a 2017-08-21 22:39:10 <TRACE> CLI: disable transit_ams_1 2017-08-21 22:39:10 <INFO> Disabling protocol transit_ams_1 2017-08-21 22:39:10 <TRACE> transit_ams_1: Shutting down 2017-08-21 22:39:10 <TRACE> transit_ams_1: State changed to stop 2017-08-21 22:39:10 <TRACE> transit_ams_1: State changed to flush 2017-08-21 22:39:11 <TRACE> coes: Connecting to fd93:2559:f2ef::9 from local address fd93:2559:f2ef::a 2017-08-21 22:39:11 <TRACE> coes: Incoming connection from fd93:2559:f2ef::9 (port 31242) accepted 2017-08-21 22:39:11 <TRACE> coes: Sending OPEN(ver=4,as=204125,hold=10,id=b974ec5c) 2017-08-21 22:39:11 <TRACE> coes: Got OPEN(as=23456,hold=10,id=b97daa22) 2017-08-21 22:39:11 <TRACE> coes: Sending KEEPALIVE 2017-08-21 22:39:11 <TRACE> coes: Got KEEPALIVE 2017-08-21 22:39:11 <TRACE> coes: BGP session established All the configuration is generated from template and works on all three nodes; I’m not sure why bird seems to be ignoring SYN until the transit is dropped on either B or C. If B and C are already connected, they continue/stay connected when the transit peer is reconnected; if I then tell bird to drop peering with either B/C from B/C, it will revert to endlessly sending SYN packets. Interestingly both B and C will reconnect to A irrespective, with no issues or problems, irrespective of any transit or connections between B and C. Any ideas? Happy to provide extra details. Diolch, Rhosyn

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having trouble getting bird an juniper to be happy with BFD
by Jerry Scharf 18 Aug '17

18 Aug '17

Hi, I'm confused with what is going on with this. Here are the config snippets for what I am doing: this sets up the bgp peer that I am monitoring: template bgp tocore { description "bgp to data center as"; local as 65304; direct; export filter inside_export; import filter inside_import; next hop self; bfd on; } protocol bgp inside_netA from tocore { neighbor 10.12.0.3 as 65304; source address 10.12.0.11; } this is the bfd config: protocol bfd { interface "edge*" { interval 300 ms; multiplier 3; }; interface "net*" { interval 300 ms; multiplier 3; }; } Other than not defining any neighbors directly, it looks just like the docs as far as I can tell. BGP is working, the peering is established and the routes are passing correctly. here is the show protocols all from birdc: bfd1 BFD master up 13:16:07 Preference: 0 Input filter: ACCEPT Output filter: REJECT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 This machine is .11 and the juniper is .3 on the 10.12.0 net. Here is the tcpdump output: 13:37:23.444104 IP 10.12.0.11.38316 > 10.12.0.3.bfd-control: BFDv1, Control, State Down, Flags: [none], length: 24 13:37:24.251246 IP 10.12.0.11.38316 > 10.12.0.3.bfd-control: BFDv1, Control, State Down, Flags: [none], length: 24 13:37:24.408134 IP 10.12.0.3.49152 > 10.12.0.11.bfd-control: BFDv1, Control, State Init, Flags: [Control Plane Independent], length: 24 13:37:25.056399 IP 10.12.0.11.38316 > 10.12.0.3.bfd-control: BFDv1, Control, State Down, Flags: [none], length: 24 13:37:25.571488 IP 10.12.0.11.bgp > 10.12.0.3.63762: Flags [P.], seq 54144952:54144971, ack 992801306, win 237, options [nop,nop,TS val 995413 ecr 83872572], length 19: BGP, length: 19 13:37:25.673017 IP 10.12.0.3.63762 > 10.12.0.11.bgp: Flags [.], ack 19, win 16384, options [nop,nop,TS val 83880802 ecr 995413], length 0 13:37:25.847516 IP 10.12.0.11.38316 > 10.12.0.3.bfd-control: BFDv1, Control, State Down, Flags: [none], length: 24 ^C13:37:26.408150 IP 10.12.0.3.49152 > 10.12.0.11.bfd-control: BFDv1, Control, State Init, Flags: [Control Plane Independent], length: 24 13:37:26.737727 IP 10.12.0.11.38316 > 10.12.0.3.bfd-control: BFDv1, Control, State Down, Flags: [none], length: 24 and so on So clearly from tcpdump bird is always saying down and so nothing is setting up. What do I need to do. This is running 1.6.0 right now. jerry -- Jerry Scharf, Soundhound DevOps "What could possibly go wrong?"

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Schuzka tymu
by Ondrej Filip 18 Aug '17

18 Aug '17

Ahoj! Sejdeme se pristi stredu (21.8.) v obvyklem terminu 14:00? F.

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