topotests: mpls vpn routes redistribution, add sr test

This setup demonstrates the redistribution and the proper
switching operations in an device connected with segment
routing network on iBGP side. The setup interconnects an
internal AS with an external connected AS via rfc4364
option 10b.

The setup performs the following tests:
- it checks for end to end connectivity from one interior
host h1 to two external hosts h2, and h3.
- it checks that the proper label values are advertised
by the ASBR to the iBGP peer, and the eBGP peer.
- it checks that the 'show mpls table' has additional
MPLS entries that permit transit mpls traffic to transit
across the ASBR. That behaviour is possible with the
'mpls bgp l3vpn-multi-domain-switching' command.
- it checks that withdraw of routes will remve the MPLS
entries.
- it checks that by unconfiguring the 'next-hop-self' option,
the external routes advertised to the internal maintain the
next-hop.
- it checks that a second prefix advertised by r3 with the
same RD, but different label value is using a new label on r2,
and that this new label value is used.
- it checks that when filtering out prefixes from r1, on r2,
then the MPLS label is deallocated, and the MPLS entry is not
present.
- it checks for label value update when the original label
value is modified by the external eBGP peer.
- it checks that by unconfiguring the 'mpls bgp
l3vpn-multi-domain-switching' command, the original label
and next-hop values are transmitted from the external to the
internal.

PR: 84718
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Acked-by: Louis Scalbert <louis.scalbert@6wind.com>
(cherry picked from commit 7b239be366c17ffd7cdcea6970d2419d7ceeca23)
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

Conflicts:
	tests/topotests/bgp_vpnv4_asbr_sr/test_bgp_vpnv4_asbr_sr.py
	mininet adaptation + change license header
	Add wait and count argument to check_ping

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>

tests/topotests/bgp_vpnv4_asbr_sr/h1/zebra.conf

@@ -0,0 +1,7 @@
+log stdout
+ip route 172.31.1.0/24 172.31.0.1
+ip route 172.31.2.0/24 172.31.0.1
+interface h1-eth0
+ ip address 172.31.0.10/24
+!
+

tests/topotests/bgp_vpnv4_asbr_sr/h2/zebra.conf

@@ -0,0 +1,5 @@
+log stdout
+ip route 172.31.0.0/24 172.31.1.1
+interface h2-eth0
+ ip address 172.31.1.10/24
+!

tests/topotests/bgp_vpnv4_asbr_sr/h3/zebra.conf

@@ -0,0 +1,6 @@
+log stdout
+ip route 172.31.0.0/24 172.31.2.1
+interface h3-eth0
+ ip address 172.31.2.10/24
+!
+

tests/topotests/bgp_vpnv4_asbr_sr/r1/bgp_ipv4_routes.json

@@ -0,0 +1,49 @@
+{
+     "vrfName": "vrf1",
+     "localAS": 65500,
+     "routes":
+         {
+            "172.31.0.10/32": [
+                {
+                    "prefix": "172.31.0.10",
+                    "prefixLen": 32,
+                    "network": "172.31.0.10\/32",
+                    "nhVrfName": "default",
+                    "nexthops": [
+                        {
+                            "ip": "192.168.0.3",
+                            "afi": "ipv4",
+                            "used": true
+                        }
+                    ]
+                },
+                {
+                    "prefix": "172.31.0.10",
+                    "prefixLen": 32,
+                    "network": "172.31.0.10\/32",
+                    "nhVrfName": "default",
+                    "nexthops": [
+                        {
+                            "ip": "192.168.0.2",
+                            "afi": "ipv4",
+                            "used": true
+                        }
+                    ]
+                }
+            ],
+            "172.31.0.1/32": [
+                {
+                    "prefix": "172.31.0.1",
+                    "prefixLen": 32,
+                    "network": "172.31.0.1\/32",
+                    "nexthops": [
+                        {
+                            "ip": "0.0.0.0",
+                            "afi": "ipv4",
+                            "used": true
+                        }
+                    ]
+                }
+            ]
+         }
+}

tests/topotests/bgp_vpnv4_asbr_sr/r1/bgpd.conf

@@ -0,0 +1,23 @@
+router bgp 65500
+ bgp router-id 192.0.2.1
+ no bgp ebgp-requires-policy
+ neighbor 192.0.2.2 remote-as 65500
+ neighbor 192.0.2.2 update-source lo
+ address-family ipv4 unicast
+  no neighbor 192.0.2.2 activate
+ exit-address-family
+ address-family ipv4 vpn
+  neighbor 192.0.2.2 activate
+ exit-address-family
+!
+router bgp 65500 vrf vrf1
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export 101
+  rd vpn export 444:1
+  rt vpn both 52:100
+  export vpn
+  import vpn
+ exit-address-family
+!

tests/topotests/bgp_vpnv4_asbr_sr/r1/isisd.conf

@@ -0,0 +1,18 @@
+interface lo
+ ip router isis 1
+ isis passive
+!
+interface r1-eth0
+ ip router isis 1
+ isis hello-multiplier 3
+!
+router isis 1
+ lsp-gen-interval 2
+ net 49.0000.0000.0000.0001.00
+ is-type level-1
+ redistribute ipv4 connected level-1
+ segment-routing on
+ segment-routing global-block 16000 23999
+ segment-routing node-msd 8
+ segment-routing prefix 192.0.2.1/32 index 10 explicit-null
+!

tests/topotests/bgp_vpnv4_asbr_sr/r1/zebra.conf

@@ -0,0 +1,10 @@
+log stdout
+interface lo
+ ip address 192.0.2.1/32
+!
+interface r1-eth1 vrf vrf1
+ ip address 172.31.0.1/24
+!
+interface r1-eth0
+ ip address 192.168.0.1/24
+!

tests/topotests/bgp_vpnv4_asbr_sr/r2/bgpd.conf

@@ -0,0 +1,21 @@
+debug bgp nht
+debug bgp zebra
+debug bgp labelpool
+router bgp 65500
+ bgp router-id 192.0.2.2
+ no bgp ebgp-requires-policy
+ neighbor 192.0.2.1 remote-as 65500
+ neighbor 192.0.2.1 update-source lo
+ neighbor 192.168.1.3 remote-as 65501
+ address-family ipv4 unicast
+  no neighbor 192.168.1.3 activate
+ exit-address-family
+ address-family ipv4 vpn
+  neighbor 192.0.2.1 activate
+  neighbor 192.168.1.3 activate
+  neighbor 192.0.2.1 next-hop-self
+ exit-address-family
+!
+interface r2-eth1
+ mpls bgp forwarding
+!

tests/topotests/bgp_vpnv4_asbr_sr/r2/ipv4_vpn_summary.json

@@ -0,0 +1,28 @@
+{
+  "routerId":"192.0.2.2",
+  "as":65500,
+  "vrfId":0,
+  "vrfName":"default",
+  "peerCount":2,
+  "peers":{
+    "192.0.2.1":{
+      "remoteAs":65500,
+      "localAs":65500,
+      "version":4,
+      "pfxRcd":1,
+      "pfxSnt":3,
+      "state":"Established",
+      "peerState":"OK"
+    },
+    "192.168.1.3":{
+      "remoteAs":65501,
+      "localAs":65500,
+      "version":4,
+      "pfxRcd":3,
+      "pfxSnt":4,
+      "state":"Established",
+      "peerState":"OK"
+    }
+  },
+  "totalPeers":2
+}

tests/topotests/bgp_vpnv4_asbr_sr/r2/isisd.conf

@@ -0,0 +1,18 @@
+interface lo
+ ip router isis 1
+ isis passive
+!
+interface r2-eth0
+ ip router isis 1
+ isis hello-multiplier 3
+!
+router isis 1
+ lsp-gen-interval 2
+ net 49.0000.0000.0000.0002.00
+ is-type level-1
+ redistribute ipv4 connected level-1
+ segment-routing on
+ segment-routing global-block 16000 23999
+ segment-routing node-msd 8
+ segment-routing prefix 192.0.2.2/32 index 20 explicit-null
+!

tests/topotests/bgp_vpnv4_asbr_sr/r2/zebra.conf

@@ -0,0 +1,12 @@
+log stdout
+interface lo
+ ip address 192.0.2.2/32
+!
+interface r2-eth0
+ ip address 192.168.0.2/24
+ mpls enable
+!
+interface r2-eth1
+ ip address 192.168.1.2/24
+ mpls enable
+!

tests/topotests/bgp_vpnv4_asbr_sr/r3/bgpd.conf

@@ -0,0 +1,26 @@
+router bgp 65501
+ bgp router-id 192.0.2.3
+ no bgp ebgp-requires-policy
+ neighbor 192.168.1.2 remote-as 65500
+ address-family ipv4 unicast
+  no neighbor 192.168.1.2 activate
+ exit-address-family
+ address-family ipv4 vpn
+  neighbor 192.168.1.2 activate
+ exit-address-family
+!
+router bgp 65501 vrf vrf1
+ bgp router-id 192.0.2.3
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export 102
+  rd vpn export 444:3
+  rt vpn both 52:100
+  export vpn
+  import vpn
+  network 172.31.3.0/24
+ exit-address-family
+!
+interface r3-eth0
+ mpls bgp forwarding
+!

tests/topotests/bgp_vpnv4_asbr_sr/r3/zebra.conf

@@ -0,0 +1,14 @@
+log stdout
+ip route 192.168.1.3/32 r3-eth0
+vrf vrf1
+ ip route 172.31.3.0/24 172.31.2.10
+exit-vrf
+interface r3-eth1 vrf vrf1
+ ip address 172.31.1.1/24
+!
+interface r3-eth2 vrf vrf1
+ ip address 172.31.2.1/24
+!
+interface r3-eth0
+ ip address 192.168.1.3/24
+!