From d70ab9dcd8f054ebd5f60a29dbbd9b39f9fe7566 Mon Sep 17 00:00:00 2001 From: Juliusz Chroboczek Date: Thu, 9 Feb 2012 17:23:09 +0100 Subject: babeld: Add support for blackhole routes. Babel makes use of blackhole routes to prevent routing loops between overlapping prefixes shortly after a route is retracted (see RFC 6126 sections 2.8 and 3.5.5). This patch adds support for installing such blackhole routes. --- babeld/kernel_zebra.c | 64 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 43 insertions(+), 21 deletions(-) diff --git a/babeld/kernel_zebra.c b/babeld/kernel_zebra.c index 1df4217f..d262a86b 100644 --- a/babeld/kernel_zebra.c +++ b/babeld/kernel_zebra.c @@ -186,12 +186,16 @@ kernel_route_add_v4(const unsigned char *pref, unsigned short plen, correctly. */ SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP); - api.nexthop_num = 1; - api.nexthop = &nexthop_pointer; api.ifindex_num = 0; - - SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); - api.metric = metric; + if(metric >= KERNEL_INFINITY) { + api.flags = ZEBRA_FLAG_BLACKHOLE; + api.nexthop_num = 0; + } else { + api.nexthop_num = 1; + api.nexthop = &nexthop_pointer; + SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); + api.metric = metric; + } debugf(BABEL_DEBUG_ROUTE, "adding route (ipv4) to zebra"); return zapi_ipv4_route (ZEBRA_IPV4_ROUTE_ADD, zclient, @@ -226,13 +230,18 @@ kernel_route_add_v6(const unsigned char *pref, unsigned short plen, api.message = 0; api.safi = SAFI_UNICAST; SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP); - api.nexthop_num = 1; - api.nexthop = &nexthop_pointer; - SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX); - api.ifindex_num = 1; - api.ifindex = &tmp_ifindex; - SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); - api.metric = metric; + if(metric >= KERNEL_INFINITY) { + api.nexthop_num = 0; + api.ifindex_num = 0; + } else { + api.nexthop_num = 1; + api.nexthop = &nexthop_pointer; + SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX); + api.ifindex_num = 1; + api.ifindex = &tmp_ifindex; + SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); + api.metric = metric; + } debugf(BABEL_DEBUG_ROUTE, "adding route (ipv6) to zebra"); return zapi_ipv6_route (ZEBRA_IPV6_ROUTE_ADD, zclient, @@ -267,11 +276,16 @@ kernel_route_delete_v4(const unsigned char *pref, unsigned short plen, api.message = 0; api.safi = SAFI_UNICAST; SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP); - api.nexthop_num = 1; - api.nexthop = &nexthop_pointer; api.ifindex_num = 0; - SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); - api.metric = metric; + if(metric >= KERNEL_INFINITY) { + api.flags = ZEBRA_FLAG_BLACKHOLE; + api.nexthop_num = 0; + } else { + api.nexthop_num = 1; + api.nexthop = &nexthop_pointer; + SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); + api.metric = metric; + } debugf(BABEL_DEBUG_ROUTE, "removing route (ipv4) to zebra"); return zapi_ipv4_route (ZEBRA_IPV4_ROUTE_DELETE, zclient, @@ -307,11 +321,19 @@ kernel_route_delete_v6(const unsigned char *pref, unsigned short plen, api.message = 0; api.safi = SAFI_UNICAST; SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP); - api.nexthop_num = 1; - api.nexthop = &nexthop_pointer; - SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX); - api.ifindex_num = 1; - api.ifindex = &tmp_ifindex; + if(metric >= KERNEL_INFINITY) { + api.flags = ZEBRA_FLAG_BLACKHOLE; + api.nexthop_num = 0; + api.ifindex_num = 0; + } else { + api.nexthop_num = 1; + api.nexthop = &nexthop_pointer; + SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX); + api.ifindex_num = 1; + api.ifindex = &tmp_ifindex; + SET_FLAG(api.message, ZAPI_MESSAGE_METRIC); + api.metric = metric; + } debugf(BABEL_DEBUG_ROUTE, "removing route (ipv6) to zebra"); return zapi_ipv6_route (ZEBRA_IPV6_ROUTE_DELETE, zclient, -- cgit v1.2.1