From ddd8d8c84522297b13b9b1068ea93553b53b27d5 Mon Sep 17 00:00:00 2001
From: Gaurav Goyal <gaurav.goyal@4rf.com>
Date: Mon, 2 Nov 2020 12:11:19 +1300
Subject: [PATCH] nhrpd: Clear shortcut routes properly for all protocols

Currently when nhrp shortcuts are purged they will not be recreated. This
patch fixes that by ensuring the shortcut routes get purged correctly.

This situation can be reproduced by first allowing a shortcut to be created
then clearing the shortcut:
clear ip nhrp cache
clear ip nhrp shortcuts

Signed-off-by: Reuben Dowle <reuben.dowle@4rf.com>
---
 lib/sockunion.c    | 17 +++++++++++++++++
 lib/sockunion.h    |  1 +
 nhrpd/nhrp_route.c |  7 +++----
 3 files changed, 21 insertions(+), 4 deletions(-)
 mode change 100644 => 100755 lib/sockunion.c
 mode change 100644 => 100755 lib/sockunion.h
 mode change 100644 => 100755 nhrpd/nhrp_route.c

diff --git a/lib/sockunion.c b/lib/sockunion.c
old mode 100644
new mode 100755
index c999845659..1dbf77efa4
--- a/lib/sockunion.c
+++ b/lib/sockunion.c
@@ -708,3 +708,20 @@ static ssize_t printfrr_psu(char *buf, size_t bsz, const char *fmt,
 	fb.pos[0] = '\0';
 	return consumed;
 }
+
+int sockunion_is_null(const union sockunion *su)
+{
+	unsigned char null_s6_addr[16] = {0};
+
+	switch (sockunion_family(su)) {
+	case AF_UNSPEC:
+		return 1;
+	case AF_INET:
+		return (su->sin.sin_addr.s_addr == 0);
+	case AF_INET6:
+		return !memcmp(su->sin6.sin6_addr.s6_addr, null_s6_addr,
+			       sizeof(null_s6_addr));
+	default:
+		return 0;
+	}
+}
diff --git a/lib/sockunion.h b/lib/sockunion.h
old mode 100644
new mode 100755
index 72f12b77ca..5e80ba1090
--- a/lib/sockunion.h
+++ b/lib/sockunion.h
@@ -102,6 +102,7 @@ extern union sockunion *sockunion_getpeername(int);
 extern union sockunion *sockunion_dup(const union sockunion *);
 extern void sockunion_free(union sockunion *);
 extern void sockunion_init(union sockunion *);
+extern int sockunion_is_null(const union sockunion *su);
 
 #ifdef _FRR_ATTRIBUTE_PRINTFRR
 #pragma FRR printfrr_ext "%pSU"  (union sockunion *)
diff --git a/nhrpd/nhrp_route.c b/nhrpd/nhrp_route.c
old mode 100644
new mode 100755
index e7d35b90ff..ce2b1fe2ff
--- a/nhrpd/nhrp_route.c
+++ b/nhrpd/nhrp_route.c
@@ -56,7 +56,7 @@ static void nhrp_route_update_put(struct route_node *rn)
 	struct route_info *ri = rn->info;
 
 	if (!ri->ifp && !ri->nhrp_ifp
-	    && sockunion_family(&ri->via) == AF_UNSPEC) {
+	    && sockunion_is_null(&ri->via)) {
 		XFREE(MTYPE_NHRP_ROUTE, rn->info);
 		route_unlock_node(rn);
 	}
@@ -70,8 +70,7 @@ static void nhrp_route_update_zebra(const struct prefix *p,
 	struct route_node *rn;
 	struct route_info *ri;
 
-	rn = nhrp_route_update_get(
-		p, (sockunion_family(nexthop) != AF_UNSPEC) || ifp);
+	rn = nhrp_route_update_get(p, !sockunion_is_null(nexthop) || ifp);
 	if (rn) {
 		ri = rn->info;
 		ri->via = *nexthop;
@@ -225,7 +224,7 @@ int nhrp_route_read(ZAPI_CALLBACK_ARGS)
 	       sockunion2str(&nexthop_addr, buf, sizeof(buf)),
 	       ifp ? ifp->name : "(none)");
 
-	nhrp_route_update_zebra(&api.prefix, &nexthop_addr, ifp);
+	nhrp_route_update_zebra(&api.prefix, &nexthop_addr, added ? ifp : NULL);
 	nhrp_shortcut_prefix_change(&api.prefix, !added);
 
 	return 0;
-- 
2.39.5