lib: move check_bit into prefix common code

Make one version of check prefix bit, and put it inline
with proper prototype. This gets rid of some macro's and also some
assert() that can never happen on a non-broken compiler.

* bgpd/bgp_table.c
  * CHECK_BIT(): sayonara
  * check_bit(): sayonara
  * SET_LINK(): sayonara
  * set_link(): make use of prefix_bit() instead of check_bit()
  * bgp_node_match(): idem
  * bgp_node_lookup(): idem
  * bgp_node_get(): idem
* lib/prefix.h
  * prefix_bit(): new inline version of check_bit()
* lib/table.c
  * CHECK_BIT(): sayonara
  * check_bit(): sayonara
  * SET_LINK(): sayonara
  * set_link(): make use of prefix_bit() instead of check_bit()
  * route_node_match(): idem
  * route_node_lookup(): idem
  * route_node_get(): idem
* ospf6d/ospf6_lsdb.c
  * CHECK_BIT(): sayonara
  * ospf6_lsdb_lookup_next(): make use of prefix_bit() instead of
    CHECK_BIT()
  * ospf6_lsdb_type_router_head(): idem
  * ospf6_lsdb_type_head(): idem
* ospf6d/ospf6_route.c
  * CHECK_BIT(): sayonara
  * ospf6_route_match_head() make use of prefix_bit() instead of
  * CHECK_BIT()

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/prefix.h b/lib/prefix.h
index 9cfc1556..d3707209 100644
--- a/lib/prefix.h
+++ b/lib/prefix.h
@@ -127,6 +127,16 @@ struct prefix_rd
 /* Prefix's family member. */
 #define PREFIX_FAMILY(p)  ((p)->family)
 
+/* Check bit of the prefix. */
+static inline unsigned int
+prefix_bit (const u_char *prefix, const u_char prefixlen)
+{
+  unsigned int offset = prefixlen / 8;
+  unsigned int shift  = 7 - (prefixlen % 8);
+
+  return (prefix[offset] >> shift) & 1;
+}
+
 /* Prototypes. */
 extern int afi2family (int);
 extern int family2afi (int);