From 6320d4941777d317989209f26ca513379f729c30 Mon Sep 17 00:00:00 2001
From: zsdc <taras@vyos.io>
Date: Fri, 12 May 2023 13:56:20 +0300
Subject: [PATCH] Fix as-override behavior

Backported 9bbdb4572d3bb255211fecf1c756452ab27e91c2 from FRR 8.5
---
 bgpd/bgp_aspath.c | 22 ----------------------
 bgpd/bgp_aspath.h |  1 -
 bgpd/bgp_route.c  |  4 +---
 3 files changed, 1 insertion(+), 26 deletions(-)

diff --git a/bgpd/bgp_aspath.c b/bgpd/bgp_aspath.c
index 5cf3c60fa..9595bae5f 100644
--- a/bgpd/bgp_aspath.c
+++ b/bgpd/bgp_aspath.c
@@ -1215,28 +1215,6 @@ bool aspath_private_as_check(struct aspath *aspath)
 	return true;
 }
 
-/* Return True if the entire ASPATH consist of the specified ASN */
-bool aspath_single_asn_check(struct aspath *aspath, as_t asn)
-{
-	struct assegment *seg;
-
-	if (!(aspath && aspath->segments))
-		return false;
-
-	seg = aspath->segments;
-
-	while (seg) {
-		int i;
-
-		for (i = 0; i < seg->length; i++) {
-			if (seg->as[i] != asn)
-				return false;
-		}
-		seg = seg->next;
-	}
-	return true;
-}
-
 /* Replace all instances of the target ASN with our own ASN */
 struct aspath *aspath_replace_specific_asn(struct aspath *aspath,
 					   as_t target_asn, as_t our_asn)
diff --git a/bgpd/bgp_aspath.h b/bgpd/bgp_aspath.h
index 9df352fcd..9bab5bb7b 100644
--- a/bgpd/bgp_aspath.h
+++ b/bgpd/bgp_aspath.h
@@ -108,7 +108,6 @@ extern unsigned int aspath_get_first_as(struct aspath *);
 extern unsigned int aspath_get_last_as(struct aspath *);
 extern int aspath_loop_check(struct aspath *, as_t);
 extern bool aspath_private_as_check(struct aspath *);
-extern bool aspath_single_asn_check(struct aspath *, as_t asn);
 extern struct aspath *aspath_replace_specific_asn(struct aspath *aspath,
 						  as_t target_asn,
 						  as_t our_asn);
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 48ccb669b..6de3e2a7f 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -1571,11 +1571,9 @@ static void bgp_peer_as_override(struct bgp *bgp, afi_t afi, safi_t safi,
 				 struct peer *peer, struct attr *attr)
 {
 	if (peer->sort == BGP_PEER_EBGP
-	    && peer_af_flag_check(peer, afi, safi, PEER_FLAG_AS_OVERRIDE)) {
-		if (aspath_single_asn_check(attr->aspath, peer->as))
+	    && peer_af_flag_check(peer, afi, safi, PEER_FLAG_AS_OVERRIDE))
 			attr->aspath = aspath_replace_specific_asn(
 				attr->aspath, peer->as, bgp->as);
-	}
 }
 
 void bgp_attr_add_gshut_community(struct attr *attr)
-- 
2.34.1