2 files changed, 75 insertions, 0 deletions
diff --git a/nest/a-path.c b/nest/a-path.c
index d808bc9..3468e4a 100644
--- a/nest/a-path.c
+++ b/nest/a-path.c
@@ -99,3 +99,70 @@ as_path_getlen(struct adata *path)
   }
   return res;
 }
+
+#define MASK_PLUS do { mask = mask->next; if (!mask) return next == q; \
+		       asterix = (mask->val == PM_ANY); \
+                       if (asterix) { mask = mask->next; if (!mask) { return 1; } } \
+		       } while(0)
+
+int
+as_path_match(struct adata *path, struct f_path_mask *mask)
+{
+  int i;
+  int asterix = 0;
+  u8 *p = path->data;
+  u8 *q = p+path->length;
+  int len;
+  u8 *next;
+
+  asterix = (mask->val == PM_ANY);
+  if (asterix) { mask = mask->next; if (!mask) { return 1; } }
+
+  while (p<q) {
+    switch (*p++) {
+    case 1:	/* This is a set */
+      len = *p++;
+      {
+	u8 *p_save = p;
+	next = p_save + 2*len;
+      retry:
+	p = p_save;
+	for (i=0; i<len; i++) {
+	  if (asterix && (get_u16(p) == mask->val)) {
+	    MASK_PLUS;
+	    goto retry;
+	  }
+	  if (!asterix && (get_u16(p) == mask->val)) {
+	    p = next;
+	    MASK_PLUS;
+	    goto okay;
+	  }
+	  p+=2;
+	}
+	if (!asterix)
+	  return 0;
+      okay:
+      }
+      break;
+
+    case 2:	/* This is a sequence */
+      len = *p++;
+      for (i=0; i<len; i++) {
+	next = p+2;
+	if (asterix && (get_u16(p) == mask->val))
+	  MASK_PLUS;
+	else if (!asterix) {
+	  if (get_u16(p) != mask->val)
+	    return 0;
+	  MASK_PLUS;
+	}
+	p+=2;
+      }
+      break;
+
+    default:
+      bug("This should not be in path");
+    }
+  }
+  return 0;
+}
diff --git a/nest/attrs.h b/nest/attrs.h
index 67ec52d..ede152c 100644
--- a/nest/attrs.h
+++ b/nest/attrs.h
@@ -18,6 +18,14 @@ struct adata *as_path_prepend(struct linpool *pool, struct adata *olda, int as);
 void as_path_format(struct adata *path, byte *buf, unsigned int size);
 int as_path_getlen(struct adata *path);
 
+struct f_path_mask {
+  struct f_path_mask *next;
+  int val;
+};
+#define PM_ANY -1
+
+int as_path_match(struct adata *path, struct f_path_mask *mask);
+
 /* a-set.c */
 
 void int_set_format(struct adata *set, byte *buf, unsigned int size);