Filter: Implement last_nonaggregated operator on bgp_path

2 files changed, 31 insertions, 1 deletions

diff --git a/nest/a-path.c b/nest/a-path.c
index c9c5aefb..32e2d27e 100644
--- a/nest/a-path.c
+++ b/nest/a-path.c
@@ -220,7 +220,7 @@ as_path_get_last(struct adata *path, u32 *orig_as)
 	      p += BS * len;
 	    }
 	  break;
-	default: bug("as_path_get_first: Invalid path segment");
+	default: bug("Invalid path segment");
 	}
     }
 
@@ -229,6 +229,35 @@ as_path_get_last(struct adata *path, u32 *orig_as)
   return found;
 }
 
+u32
+as_path_get_last_nonaggregated(struct adata *path)
+{
+  u8 *p = path->data;
+  u8 *q = p+path->length;
+  u32 res = 0;
+  int len;
+
+  while (p<q)
+    {
+      switch (*p++)
+	{
+	case AS_PATH_SET:
+	  return res;
+
+	case AS_PATH_SEQUENCE:
+	  if (len = *p++)
+	    res = get_as(p + BS * (len - 1));
+	  p += BS * len;
+	  break;
+
+	default: bug("Invalid path segment");
+	}
+    }
+
+  return res;
+}
+
+
 int
 as_path_get_first(struct adata *path, u32 *last_as)
 {
diff --git a/nest/attrs.h b/nest/attrs.h
index 1d005a6a..0171c6a8 100644
--- a/nest/attrs.h
+++ b/nest/attrs.h
@@ -35,6 +35,7 @@ int as_path_getlen(struct adata *path);
 int as_path_getlen_int(struct adata *path, int bs);
 int as_path_get_first(struct adata *path, u32 *orig_as);
 int as_path_get_last(struct adata *path, u32 *last_as);
+u32 as_path_get_last_nonaggregated(struct adata *path);
 int as_path_contains(struct adata *path, u32 as, int min);
 int as_path_match_set(struct adata *path, struct f_tree *set);
 struct adata *as_path_filter(struct linpool *pool, struct adata *path, struct f_tree *set, u32 key, int pos);