From 162c5d83adecac7de8f2923bb25b70fe11dc0783 Mon Sep 17 00:00:00 2001
From: Philippe Guibert <philippe.guibert@6wind.com>
Date: Thu, 20 Apr 2023 13:10:15 +0200
Subject: [PATCH] bgpd: add a function to compare two label lists

Create a bgp_labels_same() function that does the
same operations as the static function labels_same from
bgp_mplsvpn.c.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
---
 bgpd/bgp_label.c   | 17 +++++++++++++++++
 bgpd/bgp_label.h   |  4 ++++
 bgpd/bgp_mplsvpn.c | 13 +++----------
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/bgpd/bgp_label.c b/bgpd/bgp_label.c
index 0f3faeb297..30090e0590 100644
--- a/bgpd/bgp_label.c
+++ b/bgpd/bgp_label.c
@@ -470,3 +470,20 @@ int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
 
 	return BGP_NLRI_PARSE_OK;
 }
+
+bool bgp_labels_same(const mpls_label_t *tbl_a, const uint32_t num_labels_a,
+		     const mpls_label_t *tbl_b, const uint32_t num_labels_b)
+{
+	uint32_t i;
+
+	if (num_labels_a != num_labels_b)
+		return false;
+	if (num_labels_a == 0)
+		return true;
+
+	for (i = 0; i < num_labels_a; i++) {
+		if (tbl_a[i] != tbl_b[i])
+			return false;
+	}
+	return true;
+}
diff --git a/bgpd/bgp_label.h b/bgpd/bgp_label.h
index ac7fbb27fb..b54403ee89 100644
--- a/bgpd/bgp_label.h
+++ b/bgpd/bgp_label.h
@@ -26,6 +26,10 @@ extern mpls_label_t bgp_adv_label(struct bgp_dest *dest,
 
 extern int bgp_nlri_parse_label(struct peer *peer, struct attr *attr,
 				struct bgp_nlri *packet);
+extern bool bgp_labels_same(const mpls_label_t *tbl_a,
+			    const uint32_t num_labels_a,
+			    const mpls_label_t *tbl_b,
+			    const uint32_t num_labels_b);
 
 static inline int bgp_labeled_safi(safi_t safi)
 {
diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c
index dc9bd3cff5..931d776e28 100644
--- a/bgpd/bgp_mplsvpn.c
+++ b/bgpd/bgp_mplsvpn.c
@@ -952,8 +952,6 @@ void transpose_sid(struct in6_addr *sid, uint32_t label, uint8_t offset,
 static bool labels_same(struct bgp_path_info *bpi, mpls_label_t *label,
 			uint32_t n)
 {
-	uint32_t i;
-
 	if (!bpi->extra) {
 		if (!n)
 			return true;
@@ -961,14 +959,9 @@ static bool labels_same(struct bgp_path_info *bpi, mpls_label_t *label,
 			return false;
 	}
 
-	if (n != bpi->extra->num_labels)
-		return false;
-
-	for (i = 0; i < n; ++i) {
-		if (label[i] != bpi->extra->label[i])
-			return false;
-	}
-	return true;
+	return bgp_labels_same((const mpls_label_t *)bpi->extra->label,
+			       bpi->extra->num_labels,
+			       (const mpls_label_t *)label, n);
 }
 
 /*
-- 
2.39.5