eigrpd, ospfd, pimd: Fix assumption that interface may not be up

Commit: ddbf3e60604019d4b38d51226700e2244cc531b6

This commit modified the interface up handling code in
ZAPI such that the zclient handled the decoding for you.
Prior to this commit ospf assumed that it could use the
old ifp pointer to know state before reading the stream.
This lead to a situation where ospf would `smartly` track
and do the right thing in this situation.  This commit
changed this assumption and in certain scenarios, say
a interface was changed after it was already up would
lead to situations where ospf would not properly handle
the new interface up.

Modify ospf to track data that is important to it in
it's interface->info pointer.

This code pattern was followed in both eigrp and pim.
In eigrp's case it was just behaving weirdly in any event
so fixing this pattern is not a big deal.  In pim's
case it was not properly using this so it's a no-op
to fix.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 29 insertions, 31 deletions

diff --git a/eigrpd/eigrp_interface.c b/eigrpd/eigrp_interface.c
index 6294c0dd0..ece0b4b0c 100644
--- a/eigrpd/eigrp_interface.c
+++ b/eigrpd/eigrp_interface.c
@@ -99,6 +99,9 @@ struct eigrp_interface *eigrp_if_new(struct eigrp *eigrp, struct interface *ifp,
 	ei->params.auth_type = EIGRP_AUTH_TYPE_NONE;
 	ei->params.auth_keychain = NULL;
 
+	ei->curr_bandwidth = ifp->bandwidth;
+	ei->curr_mtu = ifp->mtu;
+
 	return ei;
 }
 
@@ -139,45 +142,40 @@ static int eigrp_ifp_create(struct interface *ifp)
 
 static int eigrp_ifp_up(struct interface *ifp)
 {
-	/* Interface is already up. */
-	if (if_is_operative(ifp)) {
-		/* Temporarily keep ifp values. */
-		struct interface if_tmp;
-		memcpy(&if_tmp, ifp, sizeof(struct interface));
+	struct eigrp_interface *ei = ifp->info;
 
-		if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
-			zlog_debug("Zebra: Interface[%s] state update.",
-				   ifp->name);
+	if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
+		zlog_debug("Zebra: Interface[%s] state change to up.",
+			   ifp->name);
 
-		if (if_tmp.bandwidth != ifp->bandwidth) {
-			if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
-				zlog_debug(
-					"Zebra: Interface[%s] bandwidth change %d -> %d.",
-					ifp->name, if_tmp.bandwidth,
-					ifp->bandwidth);
+	if (!ei)
+		return 0;
 
-			//          eigrp_if_recalculate_output_cost (ifp);
-		}
+	if (ei->curr_bandwidth != ifp->bandwidth) {
+		if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
+			zlog_debug(
+				"Zebra: Interface[%s] bandwidth change %d -> %d.",
+				ifp->name, ei->curr_bandwidth,
+				ifp->bandwidth);
 
-		if (if_tmp.mtu != ifp->mtu) {
-			if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
-				zlog_debug(
-					"Zebra: Interface[%s] MTU change %u -> %u.",
-					ifp->name, if_tmp.mtu, ifp->mtu);
+		ei->curr_bandwidth = ifp->bandwidth;
+		// eigrp_if_recalculate_output_cost (ifp);
+	}
 
-			/* Must reset the interface (simulate down/up) when MTU
-			 * changes. */
-			eigrp_if_reset(ifp);
-		}
+	if (ei->curr_mtu != ifp->mtu) {
+		if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
+			zlog_debug(
+				"Zebra: Interface[%s] MTU change %u -> %u.",
+				ifp->name, ei->curr_mtu, ifp->mtu);
+
+		ei->curr_mtu = ifp->mtu;
+		/* Must reset the interface (simulate down/up) when MTU
+		 * changes. */
+		eigrp_if_reset(ifp);
 		return 0;
 	}
 
-	if (IS_DEBUG_EIGRP(zebra, ZEBRA_INTERFACE))
-		zlog_debug("Zebra: Interface[%s] state change to up.",
-			   ifp->name);
-
-	if (ifp->info)
-		eigrp_if_up(ifp->info);
+	eigrp_if_up(ifp->info);
 
 	return 0;
 }