ip: Path MTU

Type: feature

Support setting the MTU for a peer on an interface. The minimum value of
the path and interface MTU is used at forwarding time.

the path MTU is specified for a given peer, by address and table-ID.
In the forwarding plane the MTU is enfored either:
 1 - if the peer is attached, then the MTU is set on the peer's
adjacency
 2 - if the peer is not attached, it is remote, then a DPO is added to
the peer's FIB entry to perform the necessary fragmentation.

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I8b9ea6a07868b50e97e2561f18d9335407dea7ae

1 files changed, 57 insertions, 0 deletions

diff --git a/src/vnet/ip/ip.api b/src/vnet/ip/ip.api
index 3072e3e7c63..f49fc16bc1d 100644
--- a/src/vnet/ip/ip.api
+++ b/src/vnet/ip/ip.api
@@ -704,6 +704,63 @@ autoreply define ip_reassembly_enable_disable
   vl_api_ip_reass_type_t type;
 };
 
+/**
+    @brief Set a Path MTU value. i.e. a MTU value for a given neighbour.
+           The neighbour can be described as attached (w/ interface and next-hop)
+           or remote (w/ table_id and next-hop);
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param table_id - table-ID for next-hop
+    @param nh - Next hop
+    @param path_mtu - value to set, 0 is disable.
+*/
+typedef ip_path_mtu
+{
+  u32 client_index;
+  u32 context;
+  u32 table_id;
+  vl_api_address_t nh;
+  u16 path_mtu;
+};
+autoreply define ip_path_mtu_update
+{
+  u32 client_index;
+  u32 context;
+  vl_api_ip_path_mtu_t pmtu;
+};
+define ip_path_mtu_get
+{
+  u32 client_index;
+  u32 context;
+  u32 cursor;
+};
+define ip_path_mtu_get_reply
+{
+  u32 context;
+  i32 retval;
+  u32 cursor;
+};
+define ip_path_mtu_details
+{
+  u32 context;
+  vl_api_ip_path_mtu_t pmtu;
+};
+service {
+  rpc ip_path_mtu_get returns ip_path_mtu_get_reply
+    stream ip_path_mtu_details;
+};
+
+autoreply define ip_path_mtu_replace_begin
+{
+  u32 client_index;
+  u32 context;
+};
+autoreply define ip_path_mtu_replace_end
+{
+  u32 client_index;
+  u32 context;
+};
+
 /*
  * Local Variables:
  * eval: (c-set-style "gnu")