Filter our link IPv6 when migrating VMs

- New pif helper: `get_non_link_ipv6` to get
the 1st non link IPv6 of a PIF

- Use the helper in `migrate_receive` and `get_primary_address`
used in host evacuation to have a valid IPv6 of the destination host

Signed-off-by: Benjamin Reis <[email protected]>

Author: benjamreis

ocaml/xapi/xapi_host.ml

@@ -20,6 +20,7 @@ let with_lock = Xapi_stdext_threads.Threadext.Mutex.execute
 
 module Unixext = Xapi_stdext_unix.Unixext
 open Xapi_host_helpers
+open Xapi_pif_helpers
 open Db_filter_types
 open Workload_balancing
 
@@ -2555,14 +2556,10 @@ let migrate_receive ~__context ~host ~network ~options:_ =
         let configuration_mode =
           Db.PIF.get_ipv6_configuration_mode ~__context ~self:pif
         in
-        match Db.PIF.get_IPv6 ~__context ~self:pif with
+        match Xapi_pif_helpers.get_non_link_ipv6 ~__context ~pif with
         | [] ->
             ("", configuration_mode)
-        | ip :: _ ->
-            (* The CIDR is also stored in the IPv6 field of a PIF. *)
-            let ipv6 =
-              match String.split_on_char '/' ip with hd :: _ -> hd | _ -> ""
-            in
+        | ipv6 :: _ ->
             (ipv6, configuration_mode)
       )
   in

ocaml/xapi/xapi_pif_helpers.ml

@@ -255,10 +255,29 @@ let is_device_underneath_same_type ~__context pif1 pif2 =
   in
   get_device_info pif1 = get_device_info pif2
 
+let get_non_link_ipv6 ~__context ~pif =
+  let non_link_ip6s =
+    List.map
+      (fun ip6 ->
+        match Ipaddr.V6.Prefix.of_string ip6 with
+        | Error _ ->
+            None
+        | Ok ip6 ->
+            let ip6 = Ipaddr.V6.Prefix.address ip6 in
+            if Ipaddr.V6.scope ip6 = Ipaddr.Link then
+              None
+            else
+              Some (Ipaddr.V6.to_string ip6)
+      )
+      (Db.PIF.get_IPv6 ~__context ~self:pif)
+  in
+  List.map (Option.fold ~none:"" ~some:Fun.id) non_link_ip6s
+  |> List.filter (( <> ) "")
+
 let get_primary_address ~__context ~pif =
   match Db.PIF.get_primary_address_type ~__context ~self:pif with
   | `IPv4 -> (
     match Db.PIF.get_IP ~__context ~self:pif with "" -> None | ip -> Some ip
   )
   | `IPv6 ->
-      List.nth_opt (Db.PIF.get_IPv6 ~__context ~self:pif) 0
+      List.nth_opt (get_non_link_ipv6 ~__context ~pif) 0