cnat: Introduce parametric source policy

Type: feature

Change-Id: I60ae9dd1c100b587d1902a20596b99a5c8a95df7
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/plugins/cnat/cnat_snat.c b/src/plugins/cnat/cnat_snat.c
index 86fac126226..21ac8257a23 100644
--- a/src/plugins/cnat/cnat_snat.c
+++ b/src/plugins/cnat/cnat_snat.c
@@ -101,6 +101,48 @@ cnat_del_snat_prefix (ip_prefix_t * pfx)
   return 0;
 }
 
+int
+cnat_search_snat_prefix (ip46_address_t * addr, ip_address_family_t af)
+{
+  /* Returns 0 if addr matches any of the listed prefixes */
+  cnat_snat_pfx_table_t *table = &cnat_main.snat_pfx_table;
+  clib_bihash_kv_24_8_t kv, val;
+  int i, n_p, rv;
+  n_p = vec_len (table->meta[af].prefix_lengths_in_search_order);
+  if (AF_IP4 == af)
+    {
+      kv.key[0] = addr->ip4.as_u32;
+      kv.key[1] = 0;
+    }
+  else
+    {
+      kv.key[0] = addr->as_u64[0];
+      kv.key[1] = addr->as_u64[1];
+    }
+
+  /*
+   * start search from a mask length same length or shorter.
+   * we don't want matches longer than the mask passed
+   */
+  i = 0;
+  for (; i < n_p; i++)
+    {
+      int dst_address_length =
+	table->meta[af].prefix_lengths_in_search_order[i];
+      ip6_address_t *mask = &table->ip_masks[dst_address_length];
+
+      ASSERT (dst_address_length >= 0 && dst_address_length <= 128);
+      /* As lengths are decreasing, masks are increasingly specific. */
+      kv.key[0] &= mask->as_u64[0];
+      kv.key[1] &= mask->as_u64[1];
+      kv.key[2] = ((u64) af << 32) | dst_address_length;
+      rv = clib_bihash_search_inline_2_24_8 (&table->ip_hash, &kv, &val);
+      if (rv == 0)
+	return 0;
+    }
+  return -1;
+}
+
 u8 *
 format_cnat_snat_prefix (u8 * s, va_list * args)
 {