Merge "Use subset of rtarget eBGP paths when advertising vpn routes"

Juniper · May 20, 2016 · c238f40 · c238f40
2 parents 7d2abf3 + d308890
commit c238f40
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Showing 4 changed files with 49 additions and 0 deletions.
diff --git a/src/bgp/bgp_path.cc b/src/bgp/bgp_path.cc
@@ -128,6 +128,15 @@ int BgpPath::PathCompare(const BgpPath &rhs, bool allow_ecmp) const {
     return 0;
 }
 
+bool BgpPath::PathSameNeighborAs(const BgpPath &rhs) const {
+    const BgpAttr *rattr = rhs.GetAttr();
+    if (!peer_ || peer_->PeerType() != BgpProto::EBGP)
+        return false;
+    if (!rhs.peer_ || rhs.peer_->PeerType() != BgpProto::EBGP)
+        return false;
+    return (attr_->neighbor_as() == rattr->neighbor_as());
+}
+
 void BgpPath::UpdatePeerRefCount(int count) const {
     if (!peer_)
         return;

diff --git a/src/bgp/bgp_path.h b/src/bgp/bgp_path.h
@@ -126,6 +126,7 @@ class BgpPath : public Path {
 
     // Select one path over other
     int PathCompare(const BgpPath &rhs, bool allow_ecmp) const;
+    bool PathSameNeighborAs(const BgpPath &rhs) const;
 
 private:
     const IPeer *peer_;

diff --git a/src/bgp/routing-instance/rtarget_group_mgr.cc b/src/bgp/routing-instance/rtarget_group_mgr.cc
@@ -115,6 +115,7 @@ void RTargetGroupMgr::BuildRTargetDistributionGraph(BgpTable *table,
         return;
     }
 
+    const BgpPath *best_ebgp_path = NULL;
     for (Route::PathList::iterator it = rt->GetPathList().begin();
          it != rt->GetPathList().end(); it++) {
         BgpPath *path = static_cast<BgpPath *>(it.operator->());
@@ -124,6 +125,14 @@ void RTargetGroupMgr::BuildRTargetDistributionGraph(BgpTable *table,
             continue;
 
         const BgpPeer *peer = static_cast<const BgpPeer *>(path->GetPeer());
+        if (peer->PeerType() == BgpProto::EBGP) {
+            if (!best_ebgp_path) {
+                best_ebgp_path = path;
+            } else if (!best_ebgp_path->PathSameNeighborAs(*path)) {
+                continue;
+            }
+        }
+
         std::pair<RtGroup::InterestedPeerList::iterator, bool> ret =
             peer_list.insert(std::pair<const BgpPeer *,
                  RtGroup::RTargetRouteList>(peer, RtGroup::RTargetRouteList()));

diff --git a/src/bgp/test/bgp_xmpp_rtarget_test.cc b/src/bgp/test/bgp_xmpp_rtarget_test.cc
@@ -3382,6 +3382,36 @@ TEST_F(BgpXmppRTargetTest, PathSelection5) {
     DeleteInetRoute(mx_.get(), NULL, "blue", BuildPrefix());
 }
 
+//
+// If RTargetRoute is received from EBGP peers in different ASes, VPN routes
+// should be sent to peers in AS of the best EBGP path.
+//
+TEST_F(BgpXmppRTargetTest, PathSelection6) {
+    Unconfigure();
+    task_util::WaitForIdle();
+    Configure(64496, 64497, 64498);
+    agent_a_1_->Subscribe("blue", 1);
+
+    AddRouteTarget(cn1_.get(), "blue", "target:1:1001");
+    AddRouteTarget(cn2_.get(), "blue", "target:1:1001");
+    task_util::WaitForIdle();
+
+    RTargetRoute *rtgt_rt =
+        VerifyRTargetRouteExists(mx_.get(), "64496:target:1:1001");
+    TASK_UTIL_EXPECT_EQ(2, rtgt_rt->count());
+    VerifyRTargetRouteNoExists(mx_.get(), "64497:target:1:1001");
+
+    AddInetRoute(mx_.get(), NULL, "blue", BuildPrefix());
+
+    BgpRoute *inet_rt =
+        VerifyInetRouteExists(cn1_.get(), "blue", BuildPrefix());
+    usleep(50000);
+    TASK_UTIL_EXPECT_EQ(1, inet_rt->count());
+    VerifyInetRouteNoExists(cn2_.get(), "blue", BuildPrefix());
+
+    DeleteInetRoute(mx_.get(), NULL, "blue", BuildPrefix());
+}
+
 //
 // Local AS is different than the global AS.
 // Verify that RTarget route prefixes use local AS while the route target