IP routing config for local network instances

These new fields will allow to:
- use DHCP to automatically propagate routes for uplink subnets
  to applications connected to them indirectly through local network
  instances
- configure static IP routes for local network instances and propagate
  them using DHCP to connected applications

Signed-off-by: Milan Lenco <milan@zededa.com>

proto/config/netinst.proto

@@ -75,6 +75,13 @@ message NetworkInstanceLispConfig {
   bool experimental = 20;
 }
 
+message IPRoute {
+  // Destination network address in the CIDR format: <IP-address>/<prefix-length>
+  string destination_network  = 1;
+  // Gateway IP address
+  string gateway = 2;
+}
+
 message NetworkInstanceConfig {
   UUIDandVersion uuidandversion = 1;
   string displayname = 2;
@@ -107,4 +114,18 @@ message NetworkInstanceConfig {
 
   // static DNS entry, if we are running DNS/DHCP service
   repeated ZnetStaticDNSEntry dns = 41;
+  // Enable to use DHCP to automatically propagate routes for uplink subnets
+  // into applications connected to them indirectly through local network instances.
+  // This option is only valid for local network instances. For other types
+  // of network instances, it will be ignored.
+  bool propagate_connected_routes = 42;
+  // List of IP routes statically added to the network instance routing table.
+  // Statically routed subnets are also propagated to connected applications
+  // using DHCP, with gateway set to the network instance bridge IP.
+  // IP route gateway may point to an external endpoint (provided that network
+  // instance is not air-gapped), or to an IP address of one of the applications
+  // connected to the network instance.
+  // This option is only valid for local network instances. For other types
+  // of network instances, it will be ignored.
+  repeated IPRoute static_routes = 43;
 }