From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: bgpd: fix for aspa_table_equal
To: tech@openbsd.org
Date: Mon, 14 Sep 2026 09:58:38 +0200

In some edge cases the aspa_table_equal function may return true even
though the tables are not the same.

The trivial case is:
	aspa-set {
		customer-as 1 provider-as { 4 5 6 }
		customer-as 2 provider-as { 10 11 }
	}
vs.
	aspa-set {
		customer-as 1 provider-as { 5 6 }
		customer-as 2 provider-as { 10 11 4 }
	}

Right now the code checks the customer-as list comparing just the AS and
then looking at the flat array of all provider-as numbers. Since in the
above case both are the same (AS 4 moved sets but remains in the same
location in the flat array) the function reports equality even though
the tables are not equal.

Checking the number of provider-as per customer-as is enough to fix this.

OK?
-- 
:wq Claudio

Index: rde_aspa.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/rde_aspa.c,v
diff -u -p -r1.8 rde_aspa.c
--- rde_aspa.c	30 Aug 2026 23:43:22 -0000	1.8
+++ rde_aspa.c	14 Sep 2026 07:29:02 -0000
@@ -459,9 +459,12 @@ aspa_table_equal(const struct rde_aspa *
 	if (ra->maxset != rb->maxset ||
 	    ra->maxdata != rb->maxdata)
 		return 0;
-	for (i = 0; i < ra->maxset; i++)
+	for (i = 0; i < ra->maxset; i++) {
 		if (ra->sets[i].as != rb->sets[i].as)
 			return 0;
+		if (ra->sets[i].num != rb->sets[i].num)
+			return 0;
+	}
 	if (memcmp(ra->data, rb->data, ra->maxdata * sizeof(ra->data[0])) != 0)
 		return 0;