From f78420f5beba619dfad9b95d166959cb489d01e7 Mon Sep 17 00:00:00 2001
From: Benjamin Reis <benjamin.reis@vates.tech>
Date: Wed, 21 Feb 2024 14:43:27 +0100
Subject: [PATCH] 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 <benjamin.reis@vates.tech>
---
 ocaml/xapi/xapi_host.ml        |  9 +++------
 ocaml/xapi/xapi_pif_helpers.ml | 14 +++++++++++++-
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/ocaml/xapi/xapi_host.ml b/ocaml/xapi/xapi_host.ml
index 875b3be5cf2..768f33aba7b 100644
--- a/ocaml/xapi/xapi_host.ml
+++ b/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
diff --git a/ocaml/xapi/xapi_pif_helpers.ml b/ocaml/xapi/xapi_pif_helpers.ml
index fc6c9708511..4d8771730f4 100644
--- a/ocaml/xapi/xapi_pif_helpers.ml
+++ b/ocaml/xapi/xapi_pif_helpers.ml
@@ -255,10 +255,22 @@ 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