diff options
Diffstat (limited to 'src/vnet/mfib/ip4_mfib.c')
-rw-r--r-- | src/vnet/mfib/ip4_mfib.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/vnet/mfib/ip4_mfib.c b/src/vnet/mfib/ip4_mfib.c index 9d70f0b664f..d20d1f6c2b9 100644 --- a/src/vnet/mfib/ip4_mfib.c +++ b/src/vnet/mfib/ip4_mfib.c @@ -224,6 +224,38 @@ ip4_mfib_table_lookup (const ip4_mfib_t *mfib, return (FIB_NODE_INDEX_INVALID); } +fib_node_index_t +ip4_mfib_table_get_less_specific (const ip4_mfib_t *mfib, + const ip4_address_t *src, + const ip4_address_t *grp, + u32 len) +{ + u32 mask_len; + + /* + * in the absence of a tree structure for the table that allows for an O(1) + * parent get, a cheeky way to find the cover is to LPM for the prefix with + * mask-1. + * there should always be a cover, though it may be the default route. the + * default route's cover is the default route. + */ + if (len == 64) + { + /* go from (S,G) to (*,G*) */ + mask_len = 32; + } + else if (len != 0) + { + mask_len = len - 1; + } + else + { + mask_len = len; + } + + return (ip4_mfib_table_lookup(mfib, src, grp, mask_len)); +} + void ip4_mfib_table_entry_insert (ip4_mfib_t *mfib, const ip4_address_t *grp, |