[bird] Filter exported routes to avoid announcing a full view

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

host_vars/routeur-daniel.adm.crans.org/bird.yml

@@ -17,6 +17,8 @@ loc_bird:
         remote:
           as: 212424
           address: 138.195.159.249
+        allow_export_prefixes:
+          - 185.230.76.0/22+
       - name: aurore
         allow_local_as: 1
         local:
@@ -25,6 +27,8 @@ loc_bird:
         remote:
           as: 43619
           address: 185.230.79.254
+        allow_export_prefixes:
+          - 185.230.76.0/22+
   ipv6:
     id: 185.230.79.253
     binds:
@@ -40,3 +44,5 @@ loc_bird:
         remote:
           as: 43619
           address: 2a0c:700:28::2
+        allow_export_prefixes:
+          - 2a0c:700::/32+

host_vars/routeur-gulp.cachan-adm.crans.org/bird.yml

@@ -14,6 +14,8 @@ loc_bird:
         remote:
           as: 8218
           address: 158.255.113.72
+        allow_export_prefixes:
+          - 185.230.76.0/22+
   ipv6:
     id: 185.230.79.62
     binds:
@@ -28,3 +30,5 @@ loc_bird:
         remote:
           as: 8218
           address: 2001:1b48:2:103::bb:1
+        allow_export_prefixes:
+          - 2a0c:700::/32+

host_vars/routeur-jack.adm.crans.org/bird.yml

@@ -17,6 +17,8 @@ loc_bird:
         remote:
           as: 212424
           address: 138.195.159.249
+        allow_export_prefixes:
+          - 185.230.76.0/22+
       - name: aurore
         allow_local_as: 1
         local:
@@ -25,6 +27,8 @@ loc_bird:
         remote:
           as: 43619
           address: 185.230.79.254
+        allow_export_prefixes:
+          - 185.230.76.0/22+
   ipv6:
     id: 185.230.79.253
     binds:
@@ -40,3 +44,5 @@ loc_bird:
         remote:
           as: 43619
           address: 2a0c:700:28::2
+        allow_export_prefixes:
+          - 2a0c:700::/32+

host_vars/routeur-sam.adm.crans.org/bird.yml

@@ -17,6 +17,8 @@ loc_bird:
         remote:
           as: 212424
           address: 138.195.159.249
+        allow_export_prefixes:
+          - 185.230.76.0/22+
       - name: aurore
         allow_local_as: 1
         local:
@@ -25,6 +27,8 @@ loc_bird:
         remote:
           as: 43619
           address: 185.230.79.254
+        allow_export_prefixes:
+          - 185.230.76.0/22+
   ipv6:
     id: 185.230.79.253
     binds:
@@ -40,3 +44,5 @@ loc_bird:
         remote:
           as: 43619
           address: 2a0c:700:28::2
+        allow_export_prefixes:
+          - 2a0c:700::/32+

roles/bird/templates/bird/bird.conf.j2

@@ -51,6 +51,9 @@ protocol bgp {{ bgp.name }} {
 {% endif %}
 	neighbor {{ bgp.remote.address }} as {{ bgp.remote.as }};
 	import all;
-	export all;
+	export filter {
+		if ( net ~ [ {{ bgp.allow_export_prefixes|join(', ') }} ] ) then accept;
+		reject;
+	};
 }
 {% endfor %}

roles/bird/templates/bird/bird6.conf.j2

@@ -50,6 +50,9 @@ protocol bgp {{ bgp.name }} {
 {% endif %}
 	neighbor {{ bgp.remote.address }} as {{ bgp.remote.as }};
 	import all;
-	export all;
+	export filter {
+		if ( net ~ [ {{ bgp.allow_export_prefixes|join(', ') }} ] ) then accept;
+		reject;
+	};
 }
 {% endfor %}