diff options
| -rw-r--r-- | doc/bird.sgml | 24 | ||||
| -rw-r--r-- | filter/filter.h | 1 | ||||
| -rw-r--r-- | proto/bgp/bgp.c | 17 | ||||
| -rw-r--r-- | proto/bgp/config.Y | 2 |
4 files changed, 39 insertions, 5 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index bde825c3..04f9258b 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -794,11 +794,13 @@ inherited from templates can be updated by new definitions. <tag><label id="proto-import">import all | none | filter <m/name/ | filter { <m/filter commands/ } | where <m/boolean filter expression/</tag> Specify a filter to be used for filtering routes coming from the protocol to the routing table. <cf/all/ is for keeping all routes, - <cf/none/ is for dropping all routes. Default: <cf/all/. + <cf/none/ is for dropping all routes. Default: <cf/all/ (except for + EBGP). <tag><label id="proto-export">export <m/filter/</tag> This is similar to the <cf>import</cf> keyword, except that it works in - the direction from the routing table to the protocol. Default: <cf/none/. + the direction from the routing table to the protocol. Default: <cf/none/ + (except for EBGP). <tag><label id="proto-import-keep-filtered">import keep filtered <m/switch/</tag> Usually, if an import filter rejects a route, the route is forgotten. @@ -866,10 +868,12 @@ template bgp { ipv4 { table mytable4; import filter { ... }; + export none; }; ipv6 { table mytable6; import filter { ... }; + export none; }; } @@ -2073,6 +2077,7 @@ avoid routing loops. <item> <rfc id="7947"> - Internet Exchange BGP Route Server <item> <rfc id="8092"> - BGP Large Communities Attribute <item> <rfc id="8203"> - BGP Administrative Shutdown Communication +<item> <rfc id="8212"> - Default EBGP Route Propagation Behavior without Policies </itemize> <sect1>Route selection rules @@ -2459,6 +2464,12 @@ together with their appropriate channels follows. </tabular> </table> +<p>Due to <rfc id="8212">, external BGP protocol requires explicit configuration +of import and export policies (in contrast to other protocols, where default +policies of <cf/import all/ and <cf/export none/ are used in absence of explicit +configuration). Note that blanket policies like <cf/all/ or <cf/none/ can still +be used in explicit configuration. + <p>BGP channels have additional config options (together with the common ones): <descrip> @@ -3631,13 +3642,13 @@ protocol kernel kern2 { } protocol bgp bgp1 { # The outside connections - ipv4 { table as1; export all; }; + ipv4 { table as1; import all; export all; }; local as 1; neighbor 192.168.0.1 as 1001; } protocol bgp bgp2 { - ipv4 { table as2; export all; }; + ipv4 { table as2; import all; export all; }; local as 2; neighbor 10.0.0.1 as 1002; } @@ -4419,7 +4430,10 @@ protocol bgp { debug all; local as 65000; neighbor 192.168.2.1 as 65001; - ipv4 { import filter peer_in_v4; }; + ipv4 { + import filter peer_in_v4; + export none; + }; } </code> diff --git a/filter/filter.h b/filter/filter.h index c277b67c..89cd80e6 100644 --- a/filter/filter.h +++ b/filter/filter.h @@ -122,6 +122,7 @@ void val_format(struct f_val v, buffer *buf); #define FILTER_ACCEPT NULL #define FILTER_REJECT ((void *) 1) +#define FILTER_UNDEF ((void *) 2) /* Used in BGP */ /* Type numbers must be in 0..0xff range */ #define T_MASK 0xff diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c index 8da5b0aa..9db26050 100644 --- a/proto/bgp/bgp.c +++ b/proto/bgp/bgp.c @@ -99,6 +99,7 @@ * <item> <rfc id="7947"> - Internet Exchange BGP Route Server * <item> <rfc id="8092"> - BGP Large Communities Attribute * <item> <rfc id="8203"> - BGP Administrative Shutdown Communication + * <item> <rfc id="8212"> - Default EBGP Route Propagation Behavior without Policies * </itemize> */ @@ -113,6 +114,7 @@ #include "nest/cli.h" #include "nest/locks.h" #include "conf/conf.h" +#include "filter/filter.h" #include "lib/socket.h" #include "lib/resource.h" #include "lib/string.h" @@ -1621,6 +1623,7 @@ bgp_postconfig(struct proto_config *CF) { struct bgp_config *cf = (void *) CF; int internal = (cf->local_as == cf->remote_as); + int interior = internal || cf->confederation_member; /* Do not check templates at all */ if (cf->c.class == SYM_TEMPLATE) @@ -1677,6 +1680,20 @@ bgp_postconfig(struct proto_config *CF) struct bgp_channel_config *cc; WALK_LIST(cc, CF->channels) { + /* Handle undefined import filter */ + if (cc->c.in_filter == FILTER_UNDEF) + if (interior) + cc->c.in_filter = FILTER_ACCEPT; + else + cf_error("EBGP requires explicit import policy"); + + /* Handle undefined export filter */ + if (cc->c.out_filter == FILTER_UNDEF) + if (interior) + cc->c.out_filter = FILTER_REJECT; + else + cf_error("EBGP requires explicit export policy"); + /* Disable after error incompatible with restart limit action */ if ((cc->c.in_limit.action == PLA_RESTART) && cf->disable_after_error) cc->c.in_limit.action = PLA_DISABLE; diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y index 4e819eb7..04e6d666 100644 --- a/proto/bgp/config.Y +++ b/proto/bgp/config.Y @@ -163,6 +163,8 @@ bgp_channel_start: bgp_afi /* New channel */ if (!BGP_CC->desc) { + BGP_CC->c.in_filter = FILTER_UNDEF; + BGP_CC->c.out_filter = FILTER_UNDEF; BGP_CC->c.ra_mode = RA_UNDEF; BGP_CC->afi = $1; BGP_CC->desc = desc; |