From af84d6d79cec19209188f1f40d575b64aea23586 Mon Sep 17 00:00:00 2001
From: IWASE Yusuke <iwase.yusuke0@gmail.com>
Date: Thu, 22 Feb 2018 09:51:07 +0900
Subject: zclient: Avoid directly access to RIB

In order to avoid races, zclient should not access to RIB without
calling APIs of BgpServer.
But currently zclient directly accesses to the global RIB when handling
NEXTHO_UPDATE messages.

This patch fixes this problem by calling BgpServer.GetRib().

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
---
 server/zclient.go | 46 ++++++++++++++++++++++++++++------------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/server/zclient.go b/server/zclient.go
index 93cdac1b..7c311643 100644
--- a/server/zclient.go
+++ b/server/zclient.go
@@ -381,21 +381,19 @@ func createPathFromIPRouteMessage(m *zebra.Message) *table.Path {
 	return path
 }
 
-func createPathListFromNexthopUpdateMessage(m *zebra.Message, manager *table.TableManager, nhtManager *nexthopTrackingManager) (pathList, *zebra.NexthopRegisterBody, error) {
-	body := m.Body.(*zebra.NexthopUpdateBody)
-	isNexthopInvalid := len(body.Nexthops) == 0
-
-	var rfList []bgp.RouteFamily
+func rfListFromNexthopUpdateBody(body *zebra.NexthopUpdateBody) (rfList []bgp.RouteFamily) {
 	switch body.Family {
 	case uint16(syscall.AF_INET):
-		rfList = []bgp.RouteFamily{bgp.RF_IPv4_UC, bgp.RF_IPv4_VPN}
+		return []bgp.RouteFamily{bgp.RF_IPv4_UC, bgp.RF_IPv4_VPN}
 	case uint16(syscall.AF_INET6):
-		rfList = []bgp.RouteFamily{bgp.RF_IPv6_UC, bgp.RF_IPv6_VPN}
-	default:
-		return nil, nil, fmt.Errorf("invalid address family: %d", body.Family)
+		return []bgp.RouteFamily{bgp.RF_IPv6_UC, bgp.RF_IPv6_VPN}
 	}
+	return nil
+}
 
-	paths := manager.GetPathListWithNexthop(table.GLOBAL_RIB_NAME, rfList, body.Prefix)
+func createPathListFromNexthopUpdateMessage(body *zebra.NexthopUpdateBody, manager *table.TableManager, nhtManager *nexthopTrackingManager) (pathList, *zebra.NexthopRegisterBody, error) {
+	isNexthopInvalid := len(body.Nexthops) == 0
+	paths := manager.GetPathListWithNexthop(table.GLOBAL_RIB_NAME, rfListFromNexthopUpdateBody(body), body.Prefix)
 	pathsLen := len(paths)
 
 	// If there is no path bound for the updated nexthop, send
@@ -466,14 +464,26 @@ func (z *zebraClient) loop() {
 					}
 				}
 			case *zebra.NexthopUpdateBody:
-				if z.nhtManager != nil {
-					if paths, b, err := createPathListFromNexthopUpdateMessage(msg, z.server.globalRib, z.nhtManager); err != nil {
-						log.Errorf("failed to create updated path list related to nexthop %s", body.Prefix.String())
-					} else {
-						z.nhtManager.scheduleUpdate(paths)
-						if b != nil {
-							z.client.SendNexthopRegister(msg.Header.VrfId, b, true)
-						}
+				if z.nhtManager == nil {
+					continue
+				}
+				manager := &table.TableManager{
+					Tables: make(map[bgp.RouteFamily]*table.Table),
+				}
+				for _, rf := range rfListFromNexthopUpdateBody(body) {
+					rib, err := z.server.GetRib("", rf, nil)
+					if err != nil {
+						log.Errorf("failed to get global rib by family %s", rf.String())
+						continue
+					}
+					manager.Tables[rf] = rib
+				}
+				if paths, b, err := createPathListFromNexthopUpdateMessage(body, manager, z.nhtManager); err != nil {
+					log.Errorf("failed to create updated path list related to nexthop %s", body.Prefix.String())
+				} else {
+					z.nhtManager.scheduleUpdate(paths)
+					if b != nil {
+						z.client.SendNexthopRegister(msg.Header.VrfId, b, true)
 					}
 				}
 			}
-- 
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