zebra: support for MAC-IP sync routes

MAC-IP routes are used for syncing local entries across redundant
switches in an EVPN-MH setup. A path from a peer that has a local
ES as destination is tagged as a SYNC path. The SYNC path results in the
addition of local MAC and/or local neigh entry in zebra and in the
dataplane.

Implementation overview
=======================
1. Three new flags "local-inactive", "peer-active" and "peer-proxy"
are maintained per-local-MAC and per-local-Neigh entry.
2. The "peer-XXX" flags are set and cleared via SYNC path updates
from BGP. Proxy sync paths result in the setting of "peer-proxy" flag
(and non-proxies result in the "peer-active").
3. A neigh entry that has a "peer-XXX" flag set is programmed as
"static" in the dataplane.
4. A MAC entry that has a "peer-XXX" flag set or is referenced by
a sync-neigh entry (that has a "peer-XXX" flags set) is programmed
as "static" in the dataplane.
5. The sync-seq number is used to normalize the MM seq number across
all the redundant switches i.e. the max MM seq number across all
switches is used by each of the switches. This commit also includes
the changes needed for extended MM seq syncing.
6. A MAC/neigh entry has to be local-active or peer-active to sent to
BGP. An entry that is NOT local-active is sent with the proxy flag (so
BGP can "proxy" advertise it).
7. The "peer-active" flag is aged out by zebra by using a hold_timer
(this is instead of being abruptly dropped on SYNC path delete). This
age-out is needed to handle peer-switch restart (procedures are specified
in draft-rbickhart-evpn-ip-mac-proxy-adv). The holdtime needs to be
sufficiently long to allow an external neighmgr daemon or the dataplane
component to independently probe and establish local reachability of a
host. The MAC and neigh hold time values are configurable.
PS: In the future this probing may happen in FRR itself.

CLI changes to display sync info
================================
MAC
===
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
root@torm-11:mgmt:~# net show evpn mac vni 1000
Number of MACs (local and remote) known for this VNI: 6
Flags: N=sync-neighs, I=local-inactive, P=peer-active, X=peer-proxy
MAC               Type   Flags Intf/Remote ES/VTEP            VLAN  Seq #'s
00:02:00:00:00:25 local        vlan1000                       1000  0/0
02:02:00:00:00:02 local  PI    hostbond1                      1000  0/0
02:02:00:00:00:06 remote       03:00:00:00:00:02:11:00:00:01        0/0
02:02:00:00:00:01 local  X     hostbond1                      1000  0/0
00:00:00:00:00:11 local  PI    hostbond1                      1000  0/0
02:02:00:00:00:05 remote       03:00:00:00:00:02:11:00:00:01        0/0
root@torm-11:mgmt:~#
root@torm-11:mgmt:~# net show evpn mac vni 1000 mac 00:00:00:00:00:11
MAC: 00:00:00:00:00:11
 ESI: 03:00:00:00:00:01:11:00:00:01
 Intf: hostbond1(58) VLAN: 1000
 Sync-info: neigh#: 0 local-inactive peer-active >>>>>>>>>>>>
 Local Seq: 0 Remote Seq: 0
 Neighbors:
    No Neighbors
root@torm-11:mgmt:~#
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
neigh
=====
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
root@torm-11:mgmt:~# net show evpn arp vni 1003
Number of ARPs (local and remote) known for this VNI: 4
Flags: I=local-inactive, P=peer-active, X=peer-proxy
Neighbor             Type   Flags State    MAC               Remote ES/VTEP                 Seq #'s
2001:fee1:0:3::6     local        active   00:02:00:00:00:25                                0/0
45.0.3.66            local  P     active   00:02:00:00:00:66                                0/0
45.0.3.6             local        active   00:02:00:00:00:25                                0/0
fe80::202:ff:fe00:25 local        active   00:02:00:00:00:25                                0/0
root@torm-11:mgmt:~#
root@torm-11:mgmt:~# net show evpn arp vni 1003 ip 45.0.3.66
IP: 45.0.3.66
 Type: local
 State: active
 MAC: 00:02:00:00:00:66
 Sync-info: peer-active >>>>>>>>>>>>>>>>
 Local Seq: 0 Remote Seq: 0
root@torm-11:mgmt:~#
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/zebra/zebra_vxlan.h b/zebra/zebra_vxlan.h
index 0183b7366..9c8af9d1f 100644
--- a/zebra/zebra_vxlan.h
+++ b/zebra/zebra_vxlan.h
@@ -165,14 +165,15 @@ extern int zebra_vxlan_svi_down(struct interface *ifp,
 extern int zebra_vxlan_handle_kernel_neigh_update(
 	struct interface *ifp, struct interface *link_if, struct ipaddr *ip,
 	struct ethaddr *macaddr, uint16_t state, bool is_ext,
-	bool is_router);
+	bool is_router, bool local_inactive, bool dp_static);
 extern int zebra_vxlan_handle_kernel_neigh_del(struct interface *ifp,
 				       struct interface *link_if,
 				       struct ipaddr *ip);
 extern int zebra_vxlan_local_mac_add_update(struct interface *ifp,
 					    struct interface *br_if,
 					    struct ethaddr *mac, vlanid_t vid,
-					    bool sticky);
+					    bool sticky, bool local_inactive,
+						bool dp_static);
 extern int zebra_vxlan_local_mac_del(struct interface *ifp,
 				     struct interface *br_if,
 				     struct ethaddr *mac, vlanid_t vid);