From 1788c3462853e8bb955ff656007e20f402dd9af2 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 00:12:41 +0900
Subject: [PATCH 01/18] network/netdev: also check ifindex, iftype, and kind
 when assigning NetDev to Link

Even when a NetDev object with the same name found, its iftype or kind
may be different. For safety, let's also check them.
---
 src/network/netdev/netdev.c | 37 +++++++++++++++++++++++++++++++++++++
 src/network/netdev/netdev.h |  1 +
 src/network/networkd-link.c | 10 ++--------
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index cc32e6d1a6..21b897a65f 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -266,6 +266,43 @@ int netdev_get(Manager *manager, const char *name, NetDev **ret) {
         return 0;
 }
 
+void link_assign_netdev(Link *link) {
+        _unused_ _cleanup_(netdev_unrefp) NetDev *old = NULL;
+        NetDev *netdev;
+
+        assert(link);
+        assert(link->manager);
+        assert(link->ifname);
+
+        old = TAKE_PTR(link->netdev);
+
+        if (netdev_get(link->manager, link->ifname, &netdev) < 0)
+                return;
+
+        if (netdev->ifindex != link->ifindex)
+                return;
+
+        if (NETDEV_VTABLE(netdev)->iftype != link->iftype)
+                return;
+
+        if (!NETDEV_VTABLE(netdev)->skip_netdev_kind_check) {
+                const char *kind;
+
+                if (netdev->kind == NETDEV_KIND_TAP)
+                        kind = "tun"; /* the kernel does not distinguish between tun and tap */
+                else
+                        kind = netdev_kind_to_string(netdev->kind);
+
+                if (!streq_ptr(kind, link->kind))
+                        return;
+        }
+
+        link->netdev = netdev_ref(netdev);
+
+        if (netdev != old)
+                log_link_debug(link, "Found matching .netdev file: %s", netdev->filename);
+}
+
 void netdev_enter_failed(NetDev *netdev) {
         netdev->state = NETDEV_STATE_FAILED;
 }
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index d6b363d4f1..3bb4acf6c2 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -207,6 +207,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(NetDev*, netdev_unref);
 
 bool netdev_is_managed(NetDev *netdev);
 int netdev_get(Manager *manager, const char *name, NetDev **ret);
+void link_assign_netdev(Link *link);
 int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *newlink);
 int netdev_generate_hw_addr(NetDev *netdev, Link *link, const char *name,
                             const struct hw_addr_data *hw_addr, struct hw_addr_data *ret);
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 1c6f20695f..f3131a6195 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1307,18 +1307,15 @@ static int link_get_network(Link *link, Network **ret) {
 
 int link_reconfigure_impl(Link *link, bool force) {
         Network *network = NULL;
-        NetDev *netdev = NULL;
         int r;
 
         assert(link);
 
+        link_assign_netdev(link);
+
         if (IN_SET(link->state, LINK_STATE_PENDING, LINK_STATE_LINGER))
                 return 0;
 
-        r = netdev_get(link->manager, link->ifname, &netdev);
-        if (r < 0 && r != -ENOENT)
-                return r;
-
         r = link_get_network(link, &network);
         if (r < 0 && r != -ENOENT)
                 return r;
@@ -1383,9 +1380,6 @@ int link_reconfigure_impl(Link *link, bool force) {
         link_free_engines(link);
         link->network = network_unref(link->network);
 
-        netdev_unref(link->netdev);
-        link->netdev = netdev_ref(netdev);
-
         if (!network) {
                 link_set_state(link, LINK_STATE_UNMANAGED);
                 return 0;

From 72fd133dca7c6adfc9956281b51bc5548bc9235e Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 00:17:11 +0900
Subject: [PATCH 02/18] network/route: use NetDev object assigned to Link

---
 src/network/networkd-route.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c
index 9e383ee6e8..859a3cf4cd 100644
--- a/src/network/networkd-route.c
+++ b/src/network/networkd-route.c
@@ -1008,19 +1008,15 @@ static int static_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Request
 }
 
 static int link_request_wireguard_routes(Link *link, bool only_ipv4) {
-        NetDev *netdev;
         Route *route;
         int r;
 
         assert(link);
 
-        if (!streq_ptr(link->kind, "wireguard"))
+        if (!link->netdev || link->netdev->kind != NETDEV_KIND_WIREGUARD)
                 return 0;
 
-        if (netdev_get(link->manager, link->ifname, &netdev) < 0)
-                return 0;
-
-        Wireguard *w = WIREGUARD(netdev);
+        Wireguard *w = WIREGUARD(link->netdev);
 
         SET_FOREACH(route, w->routes) {
                 if (only_ipv4 && route->family != AF_INET)

From 5d7de25052fa7d086c4763af81353f7e4eb8429d Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 22:46:27 +0900
Subject: [PATCH 03/18] network/netdev: check family of received NEWLINK
 message

For safety. No functional change, just refactoring and preparation for
later commits.
---
 src/network/netdev/netdev.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 21b897a65f..6a59a8f2df 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -351,7 +351,7 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
         const char *kind;
         const char *received_kind;
         const char *received_name;
-        int r, ifindex;
+        int r, ifindex, family;
 
         assert(netdev);
         assert(message);
@@ -363,6 +363,13 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
         if (type != RTM_NEWLINK)
                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Cannot set ifindex from unexpected rtnl message type.");
 
+        r = sd_rtnl_message_get_family(message, &family);
+        if (r < 0)
+                return log_netdev_warning_errno(netdev, r, "Failed to get family from received rtnl message: %m");
+
+        if (family != AF_UNSPEC)
+                return 0; /* IFLA_LINKINFO is only contained in the message with AF_UNSPEC. */
+
         r = sd_rtnl_message_link_get_ifindex(message, &ifindex);
         if (r < 0) {
                 log_netdev_error_errno(netdev, r, "Could not get ifindex: %m");

From bc0d3f384291a958b1bca7a46098cede3a3750fe Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 22:39:50 +0900
Subject: [PATCH 04/18] network/netdev: downgrade log level in
 netdev_set_ifindex()

This also makes netdev_enter_failed() called on caller side.

No functional change, just refactoring.
---
 src/network/netdev/netdev.c | 67 ++++++++++++++-----------------------
 src/network/networkd-link.c |  1 +
 2 files changed, 27 insertions(+), 41 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 6a59a8f2df..f24ec02f7f 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -358,10 +358,10 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
 
         r = sd_netlink_message_get_type(message, &type);
         if (r < 0)
-                return log_netdev_error_errno(netdev, r, "Could not get rtnl message type: %m");
+                return log_netdev_warning_errno(netdev, r, "Could not get rtnl message type: %m");
 
         if (type != RTM_NEWLINK)
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Cannot set ifindex from unexpected rtnl message type.");
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Cannot set ifindex from unexpected rtnl message type.");
 
         r = sd_rtnl_message_get_family(message, &family);
         if (r < 0)
@@ -371,69 +371,54 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
                 return 0; /* IFLA_LINKINFO is only contained in the message with AF_UNSPEC. */
 
         r = sd_rtnl_message_link_get_ifindex(message, &ifindex);
-        if (r < 0) {
-                log_netdev_error_errno(netdev, r, "Could not get ifindex: %m");
-                netdev_enter_failed(netdev);
-                return r;
-        } else if (ifindex <= 0) {
-                log_netdev_error(netdev, "Got invalid ifindex: %d", ifindex);
-                netdev_enter_failed(netdev);
-                return -EINVAL;
-        }
+        if (r < 0)
+                return log_netdev_warning_errno(netdev, r, "Could not get ifindex: %m");
+        if (ifindex <= 0)
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Got invalid ifindex: %d", ifindex);
 
         if (netdev->ifindex > 0) {
-                if (netdev->ifindex != ifindex) {
-                        log_netdev_error(netdev, "Could not set ifindex to %d, already set to %d",
-                                         ifindex, netdev->ifindex);
-                        netdev_enter_failed(netdev);
-                        return -EEXIST;
-                } else
-                        /* ifindex already set to the same for this netdev */
-                        return 0;
+                if (netdev->ifindex != ifindex)
+                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
+                                                        "Could not set ifindex to %d, already set to %d",
+                                                        ifindex, netdev->ifindex);
+
+                /* ifindex already set to the same for this netdev */
+                return 0;
         }
 
         r = sd_netlink_message_read_string(message, IFLA_IFNAME, &received_name);
         if (r < 0)
-                return log_netdev_error_errno(netdev, r, "Could not get IFNAME: %m");
+                return log_netdev_warning_errno(netdev, r, "Could not get IFNAME: %m");
 
-        if (!streq(netdev->ifname, received_name)) {
-                log_netdev_error(netdev, "Received newlink with wrong IFNAME %s", received_name);
-                netdev_enter_failed(netdev);
-                return -EINVAL;
-        }
+        if (!streq(netdev->ifname, received_name))
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Received newlink with wrong IFNAME %s", received_name);
 
         if (!NETDEV_VTABLE(netdev)->skip_netdev_kind_check) {
 
                 r = sd_netlink_message_enter_container(message, IFLA_LINKINFO);
                 if (r < 0)
-                        return log_netdev_error_errno(netdev, r, "Could not get LINKINFO: %m");
+                        return log_netdev_warning_errno(netdev, r, "Could not get LINKINFO: %m");
 
                 r = sd_netlink_message_read_string(message, IFLA_INFO_KIND, &received_kind);
                 if (r < 0)
-                        return log_netdev_error_errno(netdev, r, "Could not get KIND: %m");
+                        return log_netdev_warning_errno(netdev, r, "Could not get KIND: %m");
 
                 r = sd_netlink_message_exit_container(message);
                 if (r < 0)
-                        return log_netdev_error_errno(netdev, r, "Could not exit container: %m");
+                        return log_netdev_warning_errno(netdev, r, "Could not exit container: %m");
 
                 if (netdev->kind == NETDEV_KIND_TAP)
                         /* the kernel does not distinguish between tun and tap */
                         kind = "tun";
-                else {
+                else
                         kind = netdev_kind_to_string(netdev->kind);
-                        if (!kind) {
-                                log_netdev_error(netdev, "Could not get kind");
-                                netdev_enter_failed(netdev);
-                                return -EINVAL;
-                        }
-                }
+                if (!kind)
+                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Could not get netdev kind.");
 
-                if (!streq(kind, received_kind)) {
-                        log_netdev_error(netdev, "Received newlink with wrong KIND %s, expected %s",
-                                         received_kind, kind);
-                        netdev_enter_failed(netdev);
-                        return -EINVAL;
-                }
+                if (!streq(kind, received_kind))
+                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                        "Received newlink with wrong KIND %s, expected %s",
+                                                        received_kind, kind);
         }
 
         netdev->ifindex = ifindex;
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index f3131a6195..0eeab6e8b0 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -2804,6 +2804,7 @@ int manager_rtnl_process_link(sd_netlink *rtnl, sd_netlink_message *message, Man
                         r = netdev_set_ifindex(netdev, message);
                         if (r < 0) {
                                 log_netdev_warning_errno(netdev, r, "Could not process new link message for netdev, ignoring: %m");
+                                netdev_enter_failed(netdev);
                                 return 0;
                         }
                 }

From 0dc71b9584d36c691e28a227f6ffad732b6e8c95 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 15:17:54 +0900
Subject: [PATCH 05/18] network/netdev: use hashmap_remove_value() on detaching
 NetDev from manager

Then, it is not necessary to free NetDev.ifname when a conflicting
.netdev file is already loaded.

This also split out netdev_detach_name() and netdev_detach_impl().

No functional change, just refactoring.
---
 src/network/netdev/netdev.c | 36 +++++++++++++++++++++++++-----------
 src/network/netdev/netdev.h |  3 +++
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index f24ec02f7f..1b01f7e453 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -191,12 +191,31 @@ static bool netdev_is_stacked(NetDev *netdev) {
         return true;
 }
 
-static void netdev_detach_from_manager(NetDev *netdev) {
-        if (netdev->ifname && netdev->manager)
-                hashmap_remove(netdev->manager->netdevs, netdev->ifname);
+NetDev* netdev_detach_name(NetDev *netdev, const char *name) {
+        assert(netdev);
+
+        if (!netdev->manager || !name)
+                return NULL; /* Already detached or not attached yet. */
+
+        return hashmap_remove_value(netdev->manager->netdevs, name, netdev);
 }
 
-static NetDev *netdev_free(NetDev *netdev) {
+static NetDev* netdev_detach_impl(NetDev *netdev) {
+        assert(netdev);
+
+        NetDev *n = netdev_detach_name(netdev, netdev->ifname);
+
+        netdev->manager = NULL;
+        return n; /* Return NULL when it is not attached yet, or already detached. */
+}
+
+void netdev_detach(NetDev *netdev) {
+        assert(netdev);
+
+        netdev_unref(netdev_detach_impl(netdev));
+}
+
+static NetDev* netdev_free(NetDev *netdev) {
         assert(netdev);
 
         /* Invoke the per-kind done() destructor, but only if the state field is initialized. We conditionalize that
@@ -211,7 +230,7 @@ static NetDev *netdev_free(NetDev *netdev) {
             NETDEV_VTABLE(netdev)->done)
                 NETDEV_VTABLE(netdev)->done(netdev);
 
-        netdev_detach_from_manager(netdev);
+        netdev_detach_impl(netdev);
 
         condition_free_list(netdev->conditions);
         free(netdev->filename);
@@ -245,9 +264,7 @@ void netdev_drop(NetDev *netdev) {
 
         log_netdev_debug(netdev, "netdev removed");
 
-        netdev_detach_from_manager(netdev);
-        netdev_unref(netdev);
-        return;
+        netdev_detach(netdev);
 }
 
 int netdev_get(Manager *manager, const char *name, NetDev **ret) {
@@ -891,9 +908,6 @@ int netdev_load_one(Manager *manager, const char *filename) {
                                                  "Device was already configured by \"%s\", ignoring %s.",
                                                  n->filename, netdev->filename);
 
-                /* Clear ifname before netdev_free() is called. Otherwise, the NetDev object 'n' is
-                 * removed from the hashmap 'manager->netdevs'. */
-                netdev->ifname = mfree(netdev->ifname);
                 return -EEXIST;
         }
         assert(r > 0);
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index 3bb4acf6c2..2d19c2f042 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -195,6 +195,9 @@ extern const NetDevVTable * const netdev_vtable[_NETDEV_KIND_MAX];
 /* For casting the various netdev kinds into a netdev */
 #define NETDEV(n) (&(n)->meta)
 
+NetDev* netdev_detach_name(NetDev *netdev, const char *name);
+void netdev_detach(NetDev *netdev);
+
 int netdev_load(Manager *manager, bool reload);
 int netdev_load_one(Manager *manager, const char *filename);
 void netdev_drop(NetDev *netdev);

From bfacb8fe1dfd0e46e115f70acb761c8f8366ad05 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 17:41:00 +0900
Subject: [PATCH 06/18] network/netdev: split out netdev_attach() and
 netdev_attach_name() from netdev_load_one()

No functional change, just refactoring and preparation for later
commits.
---
 src/network/netdev/netdev.c | 57 +++++++++++++++++++++++++++----------
 src/network/netdev/netdev.h |  2 ++
 2 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 1b01f7e453..9949ade363 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -267,6 +267,45 @@ void netdev_drop(NetDev *netdev) {
         netdev_detach(netdev);
 }
 
+int netdev_attach_name(NetDev *netdev, const char *name) {
+        int r;
+
+        assert(netdev);
+        assert(netdev->manager);
+        assert(name);
+
+        r = hashmap_ensure_put(&netdev->manager->netdevs, &string_hash_ops, name, netdev);
+        if (r == -ENOMEM)
+                return log_oom();
+        if (r == -EEXIST) {
+                NetDev *n = hashmap_get(netdev->manager->netdevs, name);
+
+                assert(n);
+                if (!streq(netdev->filename, n->filename))
+                        log_netdev_warning_errno(netdev, r,
+                                                 "Device \"%s\" was already configured by \"%s\", ignoring %s.",
+                                                 name, n->filename, netdev->filename);
+
+                return -EEXIST;
+        }
+        assert(r > 0);
+
+        return 0;
+}
+
+static int netdev_attach(NetDev *netdev) {
+        int r;
+
+        assert(netdev);
+        assert(netdev->ifname);
+
+        r = netdev_attach_name(netdev, netdev->ifname);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
 int netdev_get(Manager *manager, const char *name, NetDev **ret) {
         NetDev *netdev;
 
@@ -896,21 +935,9 @@ int netdev_load_one(Manager *manager, const char *filename) {
         if (!netdev->filename)
                 return log_oom();
 
-        r = hashmap_ensure_put(&netdev->manager->netdevs, &string_hash_ops, netdev->ifname, netdev);
-        if (r == -ENOMEM)
-                return log_oom();
-        if (r == -EEXIST) {
-                NetDev *n = hashmap_get(netdev->manager->netdevs, netdev->ifname);
-
-                assert(n);
-                if (!streq(netdev->filename, n->filename))
-                        log_netdev_warning_errno(netdev, r,
-                                                 "Device was already configured by \"%s\", ignoring %s.",
-                                                 n->filename, netdev->filename);
-
-                return -EEXIST;
-        }
-        assert(r > 0);
+        r = netdev_attach(netdev);
+        if (r < 0)
+                return r;
 
         log_netdev_debug(netdev, "loaded \"%s\"", netdev_kind_to_string(netdev->kind));
 
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index 2d19c2f042..c173ed3fd5 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -5,6 +5,7 @@
 
 #include "conf-parser.h"
 #include "ether-addr-util.h"
+#include "hash-funcs.h"
 #include "list.h"
 #include "log-link.h"
 #include "networkd-link.h"
@@ -195,6 +196,7 @@ extern const NetDevVTable * const netdev_vtable[_NETDEV_KIND_MAX];
 /* For casting the various netdev kinds into a netdev */
 #define NETDEV(n) (&(n)->meta)
 
+int netdev_attach_name(NetDev *netdev, const char *name);
 NetDev* netdev_detach_name(NetDev *netdev, const char *name);
 void netdev_detach(NetDev *netdev);
 

From 5dc20e1acdfc729c732b23fcec44cf07f4a5212e Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 00:57:25 +0900
Subject: [PATCH 07/18] network/netdev: split out netdev_set_ifindex_internal()
 and _impl()

No functional change, just refactoring and preparation for later
commits.
---
 src/network/netdev/netdev.c | 59 ++++++++++++++++++++++++-------------
 src/network/netdev/netdev.h |  2 ++
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 9949ade363..d6c78c318d 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -363,7 +363,7 @@ void netdev_enter_failed(NetDev *netdev) {
         netdev->state = NETDEV_STATE_FAILED;
 }
 
-static int netdev_enter_ready(NetDev *netdev) {
+int netdev_enter_ready(NetDev *netdev) {
         assert(netdev);
         assert(netdev->ifname);
 
@@ -402,6 +402,42 @@ static int netdev_create_handler(sd_netlink *rtnl, sd_netlink_message *m, NetDev
         return 1;
 }
 
+int netdev_set_ifindex_internal(NetDev *netdev, int ifindex) {
+        assert(netdev);
+        assert(ifindex > 0);
+
+        if (netdev->ifindex == ifindex)
+                return 0; /* Already set. */
+
+        if (netdev->ifindex > 0 && netdev->ifindex != ifindex)
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
+                                                "Could not set ifindex to %i, already set to %i.",
+                                                ifindex, netdev->ifindex);
+
+        netdev->ifindex = ifindex;
+        log_netdev_debug(netdev, "Gained index %i.", ifindex);
+        return 1; /* set new ifindex. */
+}
+
+static int netdev_set_ifindex_impl(NetDev *netdev, const char *name, int ifindex) {
+        int r;
+
+        assert(netdev);
+        assert(name);
+        assert(ifindex > 0);
+
+        if (!streq(netdev->ifname, name))
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "Received netlink message with unexpected interface name %s (ifindex=%i).",
+                                                name, ifindex);
+
+        r = netdev_set_ifindex_internal(netdev, ifindex);
+        if (r <= 0)
+                return r;
+
+        return netdev_enter_ready(netdev);
+}
+
 int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
         uint16_t type;
         const char *kind;
@@ -432,23 +468,10 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
         if (ifindex <= 0)
                 return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Got invalid ifindex: %d", ifindex);
 
-        if (netdev->ifindex > 0) {
-                if (netdev->ifindex != ifindex)
-                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
-                                                        "Could not set ifindex to %d, already set to %d",
-                                                        ifindex, netdev->ifindex);
-
-                /* ifindex already set to the same for this netdev */
-                return 0;
-        }
-
         r = sd_netlink_message_read_string(message, IFLA_IFNAME, &received_name);
         if (r < 0)
                 return log_netdev_warning_errno(netdev, r, "Could not get IFNAME: %m");
 
-        if (!streq(netdev->ifname, received_name))
-                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL), "Received newlink with wrong IFNAME %s", received_name);
-
         if (!NETDEV_VTABLE(netdev)->skip_netdev_kind_check) {
 
                 r = sd_netlink_message_enter_container(message, IFLA_LINKINFO);
@@ -477,13 +500,7 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
                                                         received_kind, kind);
         }
 
-        netdev->ifindex = ifindex;
-
-        log_netdev_debug(netdev, "netdev has index %d", netdev->ifindex);
-
-        netdev_enter_ready(netdev);
-
-        return 0;
+        return netdev_set_ifindex_impl(netdev, received_name, ifindex);
 }
 
 #define HASH_KEY SD_ID128_MAKE(52,e1,45,bd,00,6f,29,96,21,c6,30,6d,83,71,04,48)
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index c173ed3fd5..0b942caa4b 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -199,11 +199,13 @@ extern const NetDevVTable * const netdev_vtable[_NETDEV_KIND_MAX];
 int netdev_attach_name(NetDev *netdev, const char *name);
 NetDev* netdev_detach_name(NetDev *netdev, const char *name);
 void netdev_detach(NetDev *netdev);
+int netdev_set_ifindex_internal(NetDev *netdev, int ifindex);
 
 int netdev_load(Manager *manager, bool reload);
 int netdev_load_one(Manager *manager, const char *filename);
 void netdev_drop(NetDev *netdev);
 void netdev_enter_failed(NetDev *netdev);
+int netdev_enter_ready(NetDev *netdev);
 
 NetDev *netdev_unref(NetDev *netdev);
 NetDev *netdev_ref(NetDev *netdev);

From 36ca0164ab78e1ecd0fdfbede890378448c9b79e Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 23:55:46 +0900
Subject: [PATCH 08/18] network/netdev: allow to register the same NetDev
 object with multiple names

Preparation for later commits.
---
 src/network/networkd-manager.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
index 4ebecaac59..2c2956f465 100644
--- a/src/network/networkd-manager.c
+++ b/src/network/networkd-manager.c
@@ -633,7 +633,11 @@ Manager* manager_free(Manager *m) {
         m->dhcp_pd_subnet_ids = set_free(m->dhcp_pd_subnet_ids);
         m->networks = ordered_hashmap_free_with_destructor(m->networks, network_unref);
 
-        m->netdevs = hashmap_free_with_destructor(m->netdevs, netdev_unref);
+        /* The same object may be registered with multiple names, and netdev_detach() may drop multiple
+         * entries. Hence, hashmap_free_with_destructor() cannot be used. */
+        for (NetDev *n; (n = hashmap_first(m->netdevs)); )
+                netdev_detach(n);
+        m->netdevs = hashmap_free(m->netdevs);
 
         m->tuntap_fds_by_name = hashmap_free(m->tuntap_fds_by_name);
 

From c60cd572bdac896dfda70e86aca3c0ead30807f9 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 17:37:42 +0900
Subject: [PATCH 09/18] network/netdev: add attach(), detach(), set_ifindex(),
 and get_ifindex() to netdev vtable

Currently no vtable sets these functions, but will be used later.
---
 src/network/netdev/netdev.c | 23 ++++++++++++++++++++---
 src/network/netdev/netdev.h | 10 ++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index d6c78c318d..d37476bb71 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -203,6 +203,11 @@ NetDev* netdev_detach_name(NetDev *netdev, const char *name) {
 static NetDev* netdev_detach_impl(NetDev *netdev) {
         assert(netdev);
 
+        if (netdev->state != _NETDEV_STATE_INVALID &&
+            NETDEV_VTABLE(netdev) &&
+            NETDEV_VTABLE(netdev)->detach)
+                NETDEV_VTABLE(netdev)->detach(netdev);
+
         NetDev *n = netdev_detach_name(netdev, netdev->ifname);
 
         netdev->manager = NULL;
@@ -218,6 +223,8 @@ void netdev_detach(NetDev *netdev) {
 static NetDev* netdev_free(NetDev *netdev) {
         assert(netdev);
 
+        netdev_detach_impl(netdev);
+
         /* Invoke the per-kind done() destructor, but only if the state field is initialized. We conditionalize that
          * because we parse .netdev files twice: once to determine the kind (with a short, minimal NetDev structure
          * allocation, with no room for per-kind fields), and once to read the kind's properties (with a full,
@@ -230,8 +237,6 @@ static NetDev* netdev_free(NetDev *netdev) {
             NETDEV_VTABLE(netdev)->done)
                 NETDEV_VTABLE(netdev)->done(netdev);
 
-        netdev_detach_impl(netdev);
-
         condition_free_list(netdev->conditions);
         free(netdev->filename);
         strv_free(netdev->dropins);
@@ -303,6 +308,12 @@ static int netdev_attach(NetDev *netdev) {
         if (r < 0)
                 return r;
 
+        if (NETDEV_VTABLE(netdev)->attach) {
+                r = NETDEV_VTABLE(netdev)->attach(netdev);
+                if (r < 0)
+                        return r;
+        }
+
         return 0;
 }
 
@@ -335,7 +346,10 @@ void link_assign_netdev(Link *link) {
         if (netdev_get(link->manager, link->ifname, &netdev) < 0)
                 return;
 
-        if (netdev->ifindex != link->ifindex)
+        int ifindex = NETDEV_VTABLE(netdev)->get_ifindex ?
+                NETDEV_VTABLE(netdev)->get_ifindex(netdev, link->ifname) :
+                netdev->ifindex;
+        if (ifindex != link->ifindex)
                 return;
 
         if (NETDEV_VTABLE(netdev)->iftype != link->iftype)
@@ -426,6 +440,9 @@ static int netdev_set_ifindex_impl(NetDev *netdev, const char *name, int ifindex
         assert(name);
         assert(ifindex > 0);
 
+        if (NETDEV_VTABLE(netdev)->set_ifindex)
+                return NETDEV_VTABLE(netdev)->set_ifindex(netdev, name, ifindex);
+
         if (!streq(netdev->ifname, name))
                 return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
                                                 "Received netlink message with unexpected interface name %s (ifindex=%i).",
diff --git a/src/network/netdev/netdev.h b/src/network/netdev/netdev.h
index 0b942caa4b..10b9d0dd77 100644
--- a/src/network/netdev/netdev.h
+++ b/src/network/netdev/netdev.h
@@ -169,6 +169,16 @@ typedef struct NetDevVTable {
         /* verify that compulsory configuration options were specified */
         int (*config_verify)(NetDev *netdev, const char *filename);
 
+        /* attach/detach additional interfaces, e.g. veth peer or L2TP sessions. */
+        int (*attach)(NetDev *netdev);
+        void (*detach)(NetDev *netdev);
+
+        /* set ifindex of the created interface. */
+        int (*set_ifindex)(NetDev *netdev, const char *name, int ifindex);
+
+        /* get ifindex of the netdev. */
+        int (*get_ifindex)(NetDev *netdev, const char *name);
+
         /* expected iftype, e.g. ARPHRD_ETHER. */
         uint16_t iftype;
 

From 98fbb3b5b00ab0f00611814972beeffc6116b089 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 03:00:09 +0900
Subject: [PATCH 10/18] network/veth: refuse when peer and the main interface
 names are equivalent

---
 src/network/netdev/veth.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/network/netdev/veth.c b/src/network/netdev/veth.c
index 78555286d1..c9831b21b9 100644
--- a/src/network/netdev/veth.c
+++ b/src/network/netdev/veth.c
@@ -62,6 +62,10 @@ static int netdev_veth_verify(NetDev *netdev, const char *filename) {
                                                 "Veth NetDev without peer name configured in %s. Ignoring",
                                                 filename);
 
+        if (streq(v->ifname_peer, netdev->ifname))
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "Veth peer name cannot be the same as the main interface name.");
+
         return 0;
 }
 

From 909acd37b8c1a5dea447a5cc5ed3d6b03523e1b8 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 17:38:16 +0900
Subject: [PATCH 11/18] network/veth: also manage peer name by Manager

Then, the Link object for the peer interface can have a reference to the
corresponding NetDev object.
---
 src/network/netdev/veth.c | 66 +++++++++++++++++++++++++++++++++++++++
 src/network/netdev/veth.h |  1 +
 2 files changed, 67 insertions(+)

diff --git a/src/network/netdev/veth.c b/src/network/netdev/veth.c
index c9831b21b9..edebcf0a74 100644
--- a/src/network/netdev/veth.c
+++ b/src/network/netdev/veth.c
@@ -69,6 +69,68 @@ static int netdev_veth_verify(NetDev *netdev, const char *filename) {
         return 0;
 }
 
+static int netdev_veth_attach(NetDev *netdev) {
+        Veth *v = VETH(netdev);
+
+        assert(v->ifname_peer);
+        return netdev_attach_name(netdev, v->ifname_peer);
+}
+
+static void netdev_veth_detach(NetDev *netdev) {
+        Veth *v = VETH(netdev);
+
+        netdev_detach_name(netdev, v->ifname_peer);
+}
+
+static int netdev_veth_set_ifindex(NetDev *netdev, const char *name, int ifindex) {
+        Veth *v = VETH(netdev);
+        int r;
+
+        assert(name);
+        assert(ifindex > 0);
+
+        if (streq(netdev->ifname, name)) {
+                r = netdev_set_ifindex_internal(netdev, ifindex);
+                if (r <= 0)
+                        return r;
+
+        } else if (streq(v->ifname_peer, name)) {
+                if (v->ifindex_peer == ifindex)
+                        return 0; /* already set. */
+
+                if (v->ifindex_peer > 0 && v->ifindex_peer != ifindex)
+                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
+                                                        "Could not set ifindex %i for peer %s, already set to %i.",
+                                                        ifindex, v->ifname_peer, v->ifindex_peer);
+
+                v->ifindex_peer = ifindex;
+                log_netdev_debug(netdev, "Peer interface %s gained index %i.", v->ifname_peer, ifindex);
+
+        } else
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "Received netlink message with unexpected interface name %s (index=%i).",
+                                                name, ifindex);
+
+        if (netdev->ifindex > 0 && v->ifindex_peer > 0)
+                return netdev_enter_ready(netdev);
+
+        return 0;
+}
+
+static int netdev_veth_get_ifindex(NetDev *netdev, const char *name) {
+        Veth *v = VETH(netdev);
+
+        assert(name);
+
+        if (streq(netdev->ifname, name))
+                return netdev->ifindex;
+
+        if (streq(v->ifname_peer, name))
+                return v->ifindex_peer;
+
+        return -ENODEV;
+}
+
 static void veth_done(NetDev *netdev) {
         Veth *v = VETH(netdev);
 
@@ -82,6 +144,10 @@ const NetDevVTable veth_vtable = {
         .fill_message_create = netdev_veth_fill_message_create,
         .create_type = NETDEV_CREATE_INDEPENDENT,
         .config_verify = netdev_veth_verify,
+        .attach = netdev_veth_attach,
+        .detach = netdev_veth_detach,
+        .set_ifindex = netdev_veth_set_ifindex,
+        .get_ifindex = netdev_veth_get_ifindex,
         .iftype = ARPHRD_ETHER,
         .generate_mac = true,
 };
diff --git a/src/network/netdev/veth.h b/src/network/netdev/veth.h
index e0d6fd4352..8ee973385b 100644
--- a/src/network/netdev/veth.h
+++ b/src/network/netdev/veth.h
@@ -10,6 +10,7 @@ struct Veth {
 
         char *ifname_peer;
         struct hw_addr_data hw_addr_peer;
+        int ifindex_peer;
 };
 
 DEFINE_NETDEV_CAST(VETH, Veth);

From c480e4cd66a1759f7521ad093d28cbf737195f7a Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 03:05:18 +0900
Subject: [PATCH 12/18] network/l2tp: downgrade log level of several messages

Also, use log_section_warning_errno() where applicable.
---
 src/network/netdev/l2tp-tunnel.c | 42 ++++++++++++++++----------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/src/network/netdev/l2tp-tunnel.c b/src/network/netdev/l2tp-tunnel.c
index 3194f3f785..9f8287cb91 100644
--- a/src/network/netdev/l2tp-tunnel.c
+++ b/src/network/netdev/l2tp-tunnel.c
@@ -752,28 +752,28 @@ static void l2tp_tunnel_init(NetDev *netdev) {
         t->udp6_csum_tx = true;
 }
 
-static int l2tp_session_verify(L2tpSession *session) {
-        NetDev *netdev;
+#define log_session(session, fmt, ...)                                  \
+        ({                                                              \
+                const L2tpSession *_session = (session);                \
+                log_section_warning_errno(                              \
+                                _session ? _session->section : NULL,    \
+                                SYNTHETIC_ERRNO(EINVAL),                \
+                                fmt " Ignoring [L2TPSession] section.", \
+                                ##__VA_ARGS__);                         \
+        })
 
+static int l2tp_session_verify(L2tpSession *session) {
         assert(session);
         assert(session->tunnel);
 
-        netdev = NETDEV(session->tunnel);
-
         if (section_is_invalid(session->section))
                 return -EINVAL;
 
         if (!session->name)
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "%s: L2TP session without name configured. "
-                                              "Ignoring [L2TPSession] section from line %u",
-                                              session->section->filename, session->section->line);
+                return log_session(session, "L2TP session without name configured.");
 
         if (session->session_id == 0 || session->peer_session_id == 0)
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "%s: L2TP session without session IDs configured. "
-                                              "Ignoring [L2TPSession] section from line %u",
-                                              session->section->filename, session->section->line);
+                return log_session(session, "L2TP session without session IDs configured.");
 
         return 0;
 }
@@ -785,19 +785,19 @@ static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) {
         L2tpSession *session;
 
         if (!IN_SET(t->family, AF_INET, AF_INET6))
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "%s: L2TP tunnel with invalid address family configured. Ignoring",
-                                              filename);
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "%s: L2TP tunnel with invalid address family configured. Ignoring",
+                                                filename);
 
         if (!in_addr_is_set(t->family, &t->remote))
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "%s: L2TP tunnel without a remote address configured. Ignoring",
-                                              filename);
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "%s: L2TP tunnel without a remote address configured. Ignoring",
+                                                filename);
 
         if (t->tunnel_id == 0 || t->peer_tunnel_id == 0)
-                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "%s: L2TP tunnel without tunnel IDs configured. Ignoring",
-                                              filename);
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "%s: L2TP tunnel without tunnel IDs configured. Ignoring",
+                                                filename);
 
         ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
                 if (l2tp_session_verify(session) < 0)

From 121d32b09c1675aa2dbe561f33f1695a1ae3fe26 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 03:18:19 +0900
Subject: [PATCH 13/18] network/l2tp: refuse duplicated session name

---
 src/network/netdev/l2tp-tunnel.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/network/netdev/l2tp-tunnel.c b/src/network/netdev/l2tp-tunnel.c
index 9f8287cb91..b9be66c113 100644
--- a/src/network/netdev/l2tp-tunnel.c
+++ b/src/network/netdev/l2tp-tunnel.c
@@ -762,9 +762,12 @@ static void l2tp_tunnel_init(NetDev *netdev) {
                                 ##__VA_ARGS__);                         \
         })
 
-static int l2tp_session_verify(L2tpSession *session) {
+static int l2tp_session_verify(L2tpSession *session, Set **names) {
+        int r;
+
         assert(session);
         assert(session->tunnel);
+        assert(names);
 
         if (section_is_invalid(session->section))
                 return -EINVAL;
@@ -775,6 +778,15 @@ static int l2tp_session_verify(L2tpSession *session) {
         if (session->session_id == 0 || session->peer_session_id == 0)
                 return log_session(session, "L2TP session without session IDs configured.");
 
+        if (streq(session->name, NETDEV(session->tunnel)->ifname))
+                return log_session(session, "L2TP session name %s cannot be the same as the netdev name.", session->name);
+
+        r = set_ensure_put(names, &string_hash_ops, session->name);
+        if (r < 0)
+                return log_oom();
+        if (r == 0)
+                return log_session(session, "L2TP session name %s is duplicated.", session->name);
+
         return 0;
 }
 
@@ -799,8 +811,9 @@ static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) {
                                                 "%s: L2TP tunnel without tunnel IDs configured. Ignoring",
                                                 filename);
 
+        _cleanup_set_free_ Set *names = NULL;
         ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
-                if (l2tp_session_verify(session) < 0)
+                if (l2tp_session_verify(session, &names) < 0)
                         l2tp_session_free(session);
 
         return 0;

From 2d5f58cf41a55116c303c76765f8071855ee6c81 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 17:54:01 +0900
Subject: [PATCH 14/18] network/l2tp: manage l2tp session name by Manager

Then, Link object for an L2TP session can have reference to the
corresponding NetDev object.
---
 src/network/netdev/l2tp-tunnel.c | 79 ++++++++++++++++++++++++++++++++
 src/network/netdev/l2tp-tunnel.h |  1 +
 2 files changed, 80 insertions(+)

diff --git a/src/network/netdev/l2tp-tunnel.c b/src/network/netdev/l2tp-tunnel.c
index b9be66c113..c1372bb1e0 100644
--- a/src/network/netdev/l2tp-tunnel.c
+++ b/src/network/netdev/l2tp-tunnel.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <netinet/in.h>
+#include <linux/if_arp.h>
 #include <linux/l2tp.h>
 #include <linux/genetlink.h>
 
@@ -819,6 +820,78 @@ static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) {
         return 0;
 }
 
+static int netdev_l2tp_tunnel_attach(NetDev *netdev) {
+        L2tpTunnel *t = L2TP(netdev);
+        L2tpSession *session;
+        int r;
+
+        ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section) {
+                assert(session->name);
+
+                r = netdev_attach_name(netdev, session->name);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static void netdev_l2tp_tunnel_detach(NetDev *netdev) {
+        L2tpTunnel *t = L2TP(netdev);
+        L2tpSession *session;
+
+        ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
+                netdev_detach_name(netdev, session->name);
+}
+
+static int netdev_l2tp_tunnel_set_ifindex(NetDev *netdev, const char *name, int ifindex) {
+        L2tpTunnel *t = L2TP(netdev);
+        L2tpSession *session;
+        bool found = false;
+
+        assert(name);
+        assert(ifindex > 0);
+
+        ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
+                if (streq(session->name, name)) {
+                        if (session->ifindex == ifindex)
+                                return 0; /* already set. */
+                        if (session->ifindex > 0 && session->ifindex != ifindex)
+                                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
+                                                                "Could not set ifindex %i for session %s, already set to %i.",
+                                                                ifindex, session->name, session->ifindex);
+
+                        session->ifindex = ifindex;
+                        log_netdev_debug(netdev, "Session %s gained ifindex %i.", session->name, session->ifindex);
+                        found = true;
+                        break;
+                }
+
+        if (!found)
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "Received netlink message with unexpected interface name %s (ifindex=%i).",
+                                                name, ifindex);
+
+        ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
+                if (session->ifindex <= 0)
+                        return 0; /* This session is not ready yet. */
+
+        return netdev_enter_ready(netdev);
+}
+
+static int netdev_l2tp_tunnel_get_ifindex(NetDev *netdev, const char *name) {
+        L2tpTunnel *t = L2TP(netdev);
+        L2tpSession *session;
+
+        assert(name);
+
+        ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section)
+                if (streq(session->name, name))
+                        return session->ifindex;
+
+        return -ENODEV;
+}
+
 static void l2tp_tunnel_done(NetDev *netdev) {
         L2tpTunnel *t = L2TP(netdev);
 
@@ -835,4 +908,10 @@ const NetDevVTable l2tptnl_vtable = {
         .create_type = NETDEV_CREATE_INDEPENDENT,
         .is_ready_to_create = netdev_l2tp_is_ready_to_create,
         .config_verify = netdev_l2tp_tunnel_verify,
+        .attach = netdev_l2tp_tunnel_attach,
+        .detach = netdev_l2tp_tunnel_detach,
+        .set_ifindex = netdev_l2tp_tunnel_set_ifindex,
+        .get_ifindex = netdev_l2tp_tunnel_get_ifindex,
+        .iftype = ARPHRD_ETHER,
+        .skip_netdev_kind_check = true,
 };
diff --git a/src/network/netdev/l2tp-tunnel.h b/src/network/netdev/l2tp-tunnel.h
index 6028b35205..c558ed49de 100644
--- a/src/network/netdev/l2tp-tunnel.h
+++ b/src/network/netdev/l2tp-tunnel.h
@@ -37,6 +37,7 @@ typedef struct L2tpSession {
         ConfigSection *section;
 
         char *name;
+        int ifindex;
 
         uint32_t session_id;
         uint32_t peer_session_id;

From 971c0ce85c558bfb85ef04550b6e95b52e4b5b82 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 03:01:14 +0900
Subject: [PATCH 15/18] network/vxcan: refuse when peer and the main interface
 names are equivalent

---
 src/network/netdev/vxcan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/network/netdev/vxcan.c b/src/network/netdev/vxcan.c
index c0343f45b6..c129d24734 100644
--- a/src/network/netdev/vxcan.c
+++ b/src/network/netdev/vxcan.c
@@ -38,6 +38,10 @@ static int netdev_vxcan_verify(NetDev *netdev, const char *filename) {
                 return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
                                                 "VxCan NetDev without peer name configured in %s. Ignoring", filename);
 
+        if (streq(v->ifname_peer, netdev->ifname))
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "VxCan peer name cannot be the same as the main interface name.");
+
         return 0;
 }
 

From d0899c6a55060a9d50d3e5e4b7fe0ba3fa715d88 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 9 Sep 2024 18:00:28 +0900
Subject: [PATCH 16/18] network/vxcan: also manage peer interface name by
 manager

Then, the Link object for the peer interface can have a reference to the
corresponding NetDev object.
---
 src/network/netdev/vxcan.c | 65 ++++++++++++++++++++++++++++++++++++++
 src/network/netdev/vxcan.h |  1 +
 2 files changed, 66 insertions(+)

diff --git a/src/network/netdev/vxcan.c b/src/network/netdev/vxcan.c
index c129d24734..929d70f61a 100644
--- a/src/network/netdev/vxcan.c
+++ b/src/network/netdev/vxcan.c
@@ -45,6 +45,67 @@ static int netdev_vxcan_verify(NetDev *netdev, const char *filename) {
         return 0;
 }
 
+static int netdev_vxcan_attach(NetDev *netdev) {
+        VxCan *v = VXCAN(netdev);
+        assert(v->ifname_peer);
+
+        return netdev_attach_name(netdev, v->ifname_peer);
+}
+
+static void netdev_vxcan_detach(NetDev *netdev) {
+        VxCan *v = VXCAN(netdev);
+
+        netdev_detach_name(netdev, v->ifname_peer);
+}
+
+static int netdev_vxcan_set_ifindex(NetDev *netdev, const char *name, int ifindex) {
+        VxCan *v = VXCAN(netdev);
+        int r;
+
+        assert(name);
+        assert(ifindex > 0);
+
+        if (streq(netdev->ifname, name)) {
+                r = netdev_set_ifindex_internal(netdev, ifindex);
+                if (r <= 0)
+                        return r;
+
+        } else if (streq(v->ifname_peer, name)) {
+                if (v->ifindex_peer == ifindex)
+                        return 0; /* already set */
+                if (v->ifindex_peer > 0 && v->ifindex_peer != ifindex)
+                        return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EEXIST),
+                                                        "Could not set ifindex %i for peer %s, already set to %i.",
+                                                        ifindex, v->ifname_peer, v->ifindex_peer);
+
+                v->ifindex_peer = ifindex;
+                log_netdev_debug(netdev, "Peer interface %s gained index %i.", v->ifname_peer, ifindex);
+
+        } else
+                return log_netdev_warning_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
+                                                "Received netlink message with unexpected interface name %s (ifindex=%i).",
+                                                name, ifindex);
+
+        if (netdev->ifindex > 0 && v->ifindex_peer > 0)
+                return netdev_enter_ready(netdev);
+
+        return 0;
+}
+
+static int netdev_vxcan_get_ifindex(NetDev *netdev, const char *name) {
+        VxCan *v = VXCAN(netdev);
+
+        assert(name);
+
+        if (streq(netdev->ifname, name))
+                return netdev->ifindex;
+
+        if (streq(v->ifname_peer, name))
+                return v->ifindex_peer;
+
+        return -ENODEV;
+}
+
 static void vxcan_done(NetDev *netdev) {
         VxCan *v = VXCAN(netdev);
 
@@ -58,5 +119,9 @@ const NetDevVTable vxcan_vtable = {
         .fill_message_create = netdev_vxcan_fill_message_create,
         .create_type = NETDEV_CREATE_INDEPENDENT,
         .config_verify = netdev_vxcan_verify,
+        .attach = netdev_vxcan_attach,
+        .detach = netdev_vxcan_detach,
+        .set_ifindex = netdev_vxcan_set_ifindex,
+        .get_ifindex = netdev_vxcan_get_ifindex,
         .iftype = ARPHRD_CAN,
 };
diff --git a/src/network/netdev/vxcan.h b/src/network/netdev/vxcan.h
index 47be3f017d..b835ce2c91 100644
--- a/src/network/netdev/vxcan.h
+++ b/src/network/netdev/vxcan.h
@@ -9,6 +9,7 @@ struct VxCan {
         NetDev meta;
 
         char *ifname_peer;
+        int ifindex_peer;
 };
 
 DEFINE_NETDEV_CAST(VXCAN, VxCan);

From f49c8e6553cc8362f8da6d17eb2a63d58476926e Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 16:35:27 +0900
Subject: [PATCH 17/18] network/state-file: save assigned .netdev file even if
 the interface is unmanaged

Follow-up for 2cf9b1a0eed7bcd85543e19ba6f0d26767fe1163.
---
 src/network/networkd-state-file.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/network/networkd-state-file.c b/src/network/networkd-state-file.c
index d89097b428..481e2d930b 100644
--- a/src/network/networkd-state-file.c
+++ b/src/network/networkd-state-file.c
@@ -623,6 +623,12 @@ static int link_save(Link *link) {
                 "IPV6_ADDRESS_STATE=%s\n",
                 admin_state, oper_state, carrier_state, address_state, ipv4_address_state, ipv6_address_state);
 
+        if (link->netdev) {
+                r = serialize_config_files(f, "NETDEV", link->netdev->filename, link->netdev->dropins);
+                if (r < 0)
+                        return r;
+        }
+
         if (link->network) {
                 const char *online_state, *captive_portal;
                 bool space = false;
@@ -650,12 +656,6 @@ static int link_save(Link *link) {
                 if (r < 0)
                         return r;
 
-                if (link->netdev) {
-                        r = serialize_config_files(f, "NETDEV", link->netdev->filename, link->netdev->dropins);
-                        if (r < 0)
-                                return r;
-                }
-
                 /************************************************************/
 
                 fputs("DNS=", f);

From 8f28d342465524d9d52a2b89582083d2ff200b76 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 Sep 2024 16:37:55 +0900
Subject: [PATCH 18/18] test-network: add test more cases for assigned units
 for each interface

---
 test/test-network/systemd-networkd-tests.py | 135 ++++++++++++++++++++
 1 file changed, 135 insertions(+)

diff --git a/test/test-network/systemd-networkd-tests.py b/test/test-network/systemd-networkd-tests.py
index 3989fc0401..a596537ffa 100755
--- a/test/test-network/systemd-networkd-tests.py
+++ b/test/test-network/systemd-networkd-tests.py
@@ -1240,6 +1240,20 @@ class Utilities():
         else:
             self.fail(f'"{contents}" not found in journal.')
 
+    def networkctl_check_unit(self, ifname, netdev_file=None, network_file=None, link_file=None):
+        output = networkctl_status(ifname)
+        print(output)
+        if netdev_file:
+            self.assertRegex(output, rf'NetDev File: .*/{netdev_file}\.netdev')
+        else:
+            self.assertNotIn('NetDev File:', output)
+        if network_file:
+            self.assertRegex(output, rf'Network File: .*/{network_file}\.network')
+        else:
+            self.assertIn('Network File: n/a', output)
+        if link_file:
+            self.assertRegex(output, rf'Link File: .*/{link_file}\.link')
+
 class NetworkctlTests(unittest.TestCase, Utilities):
 
     def setUp(self):
@@ -1551,6 +1565,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('bareudp99:degraded')
+        self.networkctl_check_unit('bareudp99', '25-bareudp', '26-netdev-link-local-addressing-yes')
 
         output = check_output('ip -d link show bareudp99')
         print(output)
@@ -1564,6 +1579,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('batadv99:degraded')
+        self.networkctl_check_unit('batadv99', '25-batadv', '26-netdev-link-local-addressing-yes')
 
         output = check_output('ip -d link show batadv99')
         print(output)
@@ -1574,6 +1590,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('bridge99:no-carrier')
+        self.networkctl_check_unit('bridge99', '25-bridge', '25-bridge-configure-without-carrier')
 
         tick = os.sysconf('SC_CLK_TCK')
         self.assertEqual(9, round(float(read_link_attr('bridge99', 'bridge', 'hello_time')) / tick))
@@ -1607,6 +1624,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('bond99:off', 'bond98:off', 'bond97:off', setup_state='unmanaged')
+        self.networkctl_check_unit('bond99', '25-bond')
+        self.networkctl_check_unit('bond98', '25-bond-balanced-tlb')
+        self.networkctl_check_unit('bond97', '25-bond-property')
 
         self.check_link_attr('bond99', 'bonding', 'mode',              '802.3ad 4')
         self.check_link_attr('bond99', 'bonding', 'xmit_hash_policy',  'layer3+4 1')
@@ -1646,6 +1666,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('test1:degraded', 'vlan99:routable')
+        self.networkctl_check_unit('vlan99', '21-vlan', '21-vlan')
+        self.networkctl_check_unit('test1', '11-dummy', '21-vlan-test1')
 
         output = check_output('ip -d link show test1')
         print(output)
@@ -1680,6 +1702,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
         self.wait_online('bond99:off')
         self.wait_operstate('vlan99', operstate='off', setup_state='configuring', setup_timeout=10)
+        self.networkctl_check_unit('vlan99', '21-vlan-on-bond', '21-vlan-on-bond')
+        self.networkctl_check_unit('bond99', '21-bond-802.3ad', '21-bond-802.3ad')
 
         self.check_networkd_log('vlan99: Could not bring up interface, ignoring: Network is down')
 
@@ -1705,6 +1729,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
 
                 self.wait_online('macvtap99:degraded',
                                  'test1:carrier' if mode == 'passthru' else 'test1:degraded')
+                self.networkctl_check_unit('macvtap99', '21-macvtap', '26-netdev-link-local-addressing-yes')
+                self.networkctl_check_unit('test1', '11-dummy', '25-macvtap')
 
                 output = check_output('ip -d link show macvtap99')
                 print(output)
@@ -1729,6 +1755,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
 
                 self.wait_online('macvlan99:degraded',
                                  'test1:carrier' if mode == 'passthru' else 'test1:degraded')
+                self.networkctl_check_unit('macvlan99', '21-macvlan', '26-netdev-link-local-addressing-yes')
+                self.networkctl_check_unit('test1', '11-dummy', '25-macvlan')
 
                 output = check_output('ip -d link show test1')
                 print(output)
@@ -1776,6 +1804,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
 
                 start_networkd()
                 self.wait_online('ipvlan99:degraded', 'test1:degraded')
+                self.networkctl_check_unit('ipvlan99', '25-ipvlan', '26-netdev-link-local-addressing-yes')
+                self.networkctl_check_unit('test1', '11-dummy', '25-ipvlan')
 
                 output = check_output('ip -d link show ipvlan99')
                 print(output)
@@ -1799,6 +1829,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
 
                 start_networkd()
                 self.wait_online('ipvtap99:degraded', 'test1:degraded')
+                self.networkctl_check_unit('ipvtap99', '25-ipvtap', '26-netdev-link-local-addressing-yes')
+                self.networkctl_check_unit('test1', '11-dummy', '25-ipvtap')
 
                 output = check_output('ip -d link show ipvtap99')
                 print(output)
@@ -1810,6 +1842,10 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('veth99:degraded', 'veth-peer:degraded', 'veth-mtu:degraded', 'veth-mtu-peer:degraded')
+        self.networkctl_check_unit('veth99', '25-veth', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('veth-peer', '25-veth', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('veth-mtu', '25-veth-mtu', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('veth-mtu-peer', '25-veth-mtu', '26-netdev-link-local-addressing-yes')
 
         output = check_output('ip -d link show veth99')
         print(output)
@@ -1881,12 +1917,16 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         copy_network_unit('25-tun.netdev', '25-tap.netdev', '26-netdev-link-local-addressing-yes.network')
         start_networkd()
         self.wait_online('testtun99:degraded', 'testtap99:degraded')
+        self.networkctl_check_unit('testtap99', '25-tap', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('testtun99', '25-tun', '26-netdev-link-local-addressing-yes')
 
         self.check_tuntap(True)
 
         remove_network_unit('26-netdev-link-local-addressing-yes.network')
         restart_networkd()
         self.wait_online('testtun99:degraded', 'testtap99:degraded', setup_state='unmanaged')
+        self.networkctl_check_unit('testtap99', '25-tap')
+        self.networkctl_check_unit('testtun99', '25-tun')
 
         self.check_tuntap(True)
 
@@ -1894,6 +1934,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         unmanage_existing_links()
         restart_networkd()
         self.wait_online('testtun99:off', 'testtap99:off', setup_state='unmanaged')
+        self.networkctl_check_unit('testtap99')
+        self.networkctl_check_unit('testtun99')
 
         self.check_tuntap(False)
 
@@ -1903,6 +1945,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('vrf99:carrier')
+        self.networkctl_check_unit('vrf99', '25-vrf', '26-netdev-link-local-addressing-yes')
 
     @expectedFailureIfModuleIsNotAvailable('vcan')
     def test_vcan(self):
@@ -1913,6 +1956,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         self.wait_online('vcan99:carrier', 'vcan98:carrier')
         # For can devices, 'carrier' is the default required operational state.
         self.wait_online('vcan99', 'vcan98')
+        self.networkctl_check_unit('vcan99', '25-vcan', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('vcan98', '25-vcan98', '25-vcan98')
 
         # https://github.com/systemd/systemd/issues/30140
         output = check_output('ip -d link show vcan99')
@@ -1931,6 +1976,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         self.wait_online('vxcan99:carrier', 'vxcan-peer:carrier')
         # For can devices, 'carrier' is the default required operational state.
         self.wait_online('vxcan99', 'vxcan-peer')
+        self.networkctl_check_unit('vxcan99', '25-vxcan', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('vxcan-peer', '25-vxcan', '26-netdev-link-local-addressing-yes')
 
     @expectedFailureIfModuleIsNotAvailable('wireguard')
     def test_wireguard(self):
@@ -1944,6 +1991,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-wireguard-no-peer.netdev', '25-wireguard-no-peer.network')
         start_networkd()
         self.wait_online('wg99:routable', 'wg98:routable', 'wg97:carrier')
+        self.networkctl_check_unit('wg99', '25-wireguard', '25-wireguard')
+        self.networkctl_check_unit('wg98', '25-wireguard-23-peers', '25-wireguard-23-peers')
+        self.networkctl_check_unit('wg97', '25-wireguard-no-peer', '25-wireguard-no-peer')
 
         output = check_output('ip -4 address show dev wg99')
         print(output)
@@ -2065,6 +2115,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('geneve99:degraded')
+        self.networkctl_check_unit('geneve99', '25-geneve', '26-netdev-link-local-addressing-yes')
 
         output = check_output('ip -d link show geneve99')
         print(output)
@@ -2103,6 +2154,11 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-gre-tunnel-any-any.netdev', '25-tunnel-any-any.network')
         start_networkd()
         self.wait_online('gretun99:routable', 'gretun98:routable', 'gretun97:routable', 'gretun96:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('gretun99', '25-gre-tunnel', '25-tunnel')
+        self.networkctl_check_unit('gretun98', '25-gre-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('gretun97', '25-gre-tunnel-remote-any', '25-tunnel-remote-any')
+        self.networkctl_check_unit('gretun96', '25-gre-tunnel-any-any', '25-tunnel-any-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-gretun')
 
         output = check_output('ip -d link show gretun99')
         print(output)
@@ -2164,6 +2220,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-gretap-tunnel-local-any.netdev', '25-tunnel-local-any.network')
         start_networkd()
         self.wait_online('gretap99:routable', 'gretap98:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('gretap99', '25-gretap-tunnel', '25-tunnel')
+        self.networkctl_check_unit('gretap98', '25-gretap-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-gretap')
 
         output = check_output('ip -d link show gretap99')
         print(output)
@@ -2188,6 +2247,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-ip6gretap-tunnel-local-any.netdev', '25-tunnel-local-any.network')
         start_networkd()
         self.wait_online('ip6gretap99:routable', 'ip6gretap98:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('ip6gretap99', '25-ip6gretap-tunnel', '25-tunnel')
+        self.networkctl_check_unit('ip6gretap98', '25-ip6gretap-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-ip6gretap')
 
         output = check_output('ip -d link show ip6gretap99')
         print(output)
@@ -2204,6 +2266,11 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-vti-tunnel-any-any.netdev', '25-tunnel-any-any.network')
         start_networkd()
         self.wait_online('vtitun99:routable', 'vtitun98:routable', 'vtitun97:routable', 'vtitun96:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('vtitun99', '25-vti-tunnel', '25-tunnel')
+        self.networkctl_check_unit('vtitun98', '25-vti-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('vtitun97', '25-vti-tunnel-remote-any', '25-tunnel-remote-any')
+        self.networkctl_check_unit('vtitun96', '25-vti-tunnel-any-any', '25-tunnel-any-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-vti')
 
         output = check_output('ip -d link show vtitun99')
         print(output)
@@ -2225,6 +2292,10 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-vti6-tunnel-remote-any.netdev', '25-tunnel-remote-any.network')
         start_networkd()
         self.wait_online('vti6tun99:routable', 'vti6tun98:routable', 'vti6tun97:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('vti6tun99', '25-vti6-tunnel', '25-tunnel')
+        self.networkctl_check_unit('vti6tun98', '25-vti6-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('vti6tun97', '25-vti6-tunnel-remote-any', '25-tunnel-remote-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-vti6')
 
         output = check_output('ip -d link show vti6tun99')
         print(output)
@@ -2248,6 +2319,14 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         self.wait_online('ip6tnl99:routable', 'ip6tnl98:routable', 'ip6tnl97:routable',
                          'ip6tnl-slaac:degraded', 'ip6tnl-external:degraded',
                          'dummy98:degraded', 'veth99:routable', 'veth-peer:degraded')
+        self.networkctl_check_unit('ip6tnl99', '25-ip6tnl-tunnel', '25-tunnel')
+        self.networkctl_check_unit('ip6tnl98', '25-ip6tnl-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('ip6tnl97', '25-ip6tnl-tunnel-remote-any', '25-tunnel-remote-any')
+        self.networkctl_check_unit('ip6tnl-slaac', '25-ip6tnl-tunnel-local-slaac', '25-ip6tnl-tunnel-local-slaac')
+        self.networkctl_check_unit('ip6tnl-external', '25-ip6tnl-tunnel-external', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-ip6tnl')
+        self.networkctl_check_unit('veth99', '25-veth', '25-ip6tnl-slaac')
+        self.networkctl_check_unit('veth-peer', '25-veth', '25-ipv6-prefix')
 
         output = check_output('ip -d link show ip6tnl99')
         print(output)
@@ -2282,6 +2361,11 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-sit-tunnel-any-any.netdev', '25-tunnel-any-any.network')
         start_networkd()
         self.wait_online('sittun99:routable', 'sittun98:routable', 'sittun97:routable', 'sittun96:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('sittun99', '25-sit-tunnel', '25-tunnel')
+        self.networkctl_check_unit('sittun98', '25-sit-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('sittun97', '25-sit-tunnel-remote-any', '25-tunnel-remote-any')
+        self.networkctl_check_unit('sittun96', '25-sit-tunnel-any-any', '25-tunnel-any-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-sit')
 
         output = check_output('ip -d link show sittun99')
         print(output)
@@ -2301,6 +2385,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-isatap-tunnel.netdev', '25-tunnel.network')
         start_networkd()
         self.wait_online('isataptun99:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('isataptun99', '25-isatap-tunnel', '25-tunnel')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-isatap')
 
         output = check_output('ip -d link show isataptun99')
         print(output)
@@ -2311,6 +2397,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-6rd-tunnel.netdev', '25-tunnel.network')
         start_networkd()
         self.wait_online('sittun99:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('sittun99', '25-6rd-tunnel', '25-tunnel')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-6rd')
 
         output = check_output('ip -d link show sittun99')
         print(output)
@@ -2323,6 +2411,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-erspan0-tunnel-local-any.netdev', '25-tunnel-local-any.network')
         start_networkd()
         self.wait_online('erspan99:routable', 'erspan98:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('erspan99', '25-erspan0-tunnel', '25-tunnel')
+        self.networkctl_check_unit('erspan98', '25-erspan0-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-erspan')
 
         output = check_output('ip -d link show erspan99')
         print(output)
@@ -2351,6 +2442,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-erspan1-tunnel-local-any.netdev', '25-tunnel-local-any.network')
         start_networkd()
         self.wait_online('erspan99:routable', 'erspan98:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('erspan99', '25-erspan1-tunnel', '25-tunnel')
+        self.networkctl_check_unit('erspan98', '25-erspan1-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-erspan')
 
         output = check_output('ip -d link show erspan99')
         print(output)
@@ -2382,6 +2476,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
                           '25-erspan2-tunnel-local-any.netdev', '25-tunnel-local-any.network')
         start_networkd()
         self.wait_online('erspan99:routable', 'erspan98:routable', 'dummy98:degraded')
+        self.networkctl_check_unit('erspan99', '25-erspan2-tunnel', '25-tunnel')
+        self.networkctl_check_unit('erspan98', '25-erspan2-tunnel-local-any', '25-tunnel-local-any')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-erspan')
 
         output = check_output('ip -d link show erspan99')
         print(output)
@@ -2411,12 +2508,14 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('ipiptun99:carrier')
+        self.networkctl_check_unit('ipiptun99', '25-ipip-tunnel-independent', '26-netdev-link-local-addressing-yes')
 
     def test_tunnel_independent_loopback(self):
         copy_network_unit('25-ipip-tunnel-independent-loopback.netdev', '26-netdev-link-local-addressing-yes.network')
         start_networkd()
 
         self.wait_online('ipiptun99:carrier')
+        self.networkctl_check_unit('ipiptun99', '25-ipip-tunnel-independent-loopback', '26-netdev-link-local-addressing-yes')
 
     @expectedFailureIfModuleIsNotAvailable('xfrm_interface')
     def test_xfrm(self):
@@ -2426,6 +2525,9 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:degraded', 'xfrm98:degraded', 'xfrm99:degraded')
+        self.networkctl_check_unit('dummy98', '12-dummy', '25-xfrm')
+        self.networkctl_check_unit('xfrm98', '25-xfrm', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('xfrm99', '25-xfrm-independent', '26-netdev-link-local-addressing-yes')
 
         output = check_output('ip -d link show dev xfrm98')
         print(output)
@@ -2449,6 +2551,10 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('ipiptun96:off', 'sittun96:off', 'gretun96:off', 'gretap96:off', setup_state='unmanaged')
+        self.networkctl_check_unit('ipiptun96', '25-fou-ipip')
+        self.networkctl_check_unit('sittun96', '25-fou-sit')
+        self.networkctl_check_unit('gretun96', '25-fou-gre')
+        self.networkctl_check_unit('gretap96', '25-fou-gretap')
 
         output = check_output('ip fou show')
         print(output)
@@ -2479,6 +2585,13 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
 
         self.wait_online('test1:degraded', 'veth99:routable', 'veth-peer:degraded',
                          'vxlan99:degraded', 'vxlan98:degraded', 'vxlan97:degraded', 'vxlan-slaac:degraded')
+        self.networkctl_check_unit('test1', '11-dummy', '25-vxlan-test1')
+        self.networkctl_check_unit('veth99', '25-veth', '25-vxlan-veth99')
+        self.networkctl_check_unit('veth-peer', '25-veth', '25-ipv6-prefix')
+        self.networkctl_check_unit('vxlan99', '25-vxlan', '25-vxlan')
+        self.networkctl_check_unit('vxlan98', '25-vxlan-independent', '26-netdev-link-local-addressing-yes')
+        self.networkctl_check_unit('vxlan97', '25-vxlan-ipv6', '25-vxlan-ipv6')
+        self.networkctl_check_unit('vxlan-slaac', '25-vxlan-local-slaac', '25-vxlan-local-slaac')
 
         output = check_output('ip -d -d link show vxlan99')
         print(output)
@@ -2530,6 +2643,8 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:degraded', 'macsec99:routable')
+        self.networkctl_check_unit('dummy98', '12-dummy', '26-macsec')
+        self.networkctl_check_unit('macsec99', '25-macsec', '25-macsec')
 
         output = check_output('ip -d link show macsec99')
         print(output)
@@ -2557,6 +2672,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('nlmon99:carrier')
+        self.networkctl_check_unit('nlmon99', '25-nlmon', '26-netdev-link-local-addressing-yes')
 
     @expectedFailureIfModuleIsNotAvailable('ifb')
     def test_ifb(self):
@@ -2564,6 +2680,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('ifb99:degraded')
+        self.networkctl_check_unit('ifb99', '25-ifb', '26-netdev-link-local-addressing-yes')
 
     @unittest.skipUnless(os.cpu_count() >= 2, reason="CPU count should be >= 2 to pass this test")
     def test_rps_cpu_1(self):
@@ -2571,6 +2688,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:carrier')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-1')
 
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
@@ -2582,6 +2700,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:carrier')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-0-1')
 
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
@@ -2593,6 +2712,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:carrier')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-multi')
 
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
@@ -2605,10 +2725,12 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('dummy98:carrier')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy')
 
         # 0
         copy_network_unit('25-rps-cpu-0.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-0')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(int(output.replace(',', ''), base=16), 1)
@@ -2617,6 +2739,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # all
         copy_network_unit('25-rps-cpu-all.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-all')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(f"{int(output.replace(',', ''), base=16):x}", f'{(1 << cpu_count) - 1:x}')
@@ -2625,6 +2748,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # disable
         copy_network_unit('24-rps-cpu-disable.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '24-rps-cpu-disable')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(int(output.replace(',', ''), base=16), 0)
@@ -2633,6 +2757,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # set all again
         copy_network_unit('25-rps-cpu-all.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-all')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(f"{int(output.replace(',', ''), base=16):x}", f'{(1 << cpu_count) - 1:x}')
@@ -2641,6 +2766,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # empty -> unchanged
         copy_network_unit('24-rps-cpu-empty.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '24-rps-cpu-empty')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(f"{int(output.replace(',', ''), base=16):x}", f'{(1 << cpu_count) - 1:x}')
@@ -2649,6 +2775,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # 0, then empty -> unchanged
         copy_network_unit('25-rps-cpu-0-empty.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-0-empty')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(f"{int(output.replace(',', ''), base=16):x}", f'{(1 << cpu_count) - 1:x}')
@@ -2657,6 +2784,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # 0, then invalid -> 0
         copy_network_unit('25-rps-cpu-0-invalid.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '25-rps-cpu-0-invalid')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(int(output.replace(',', ''), base=16), 1)
@@ -2665,6 +2793,7 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         # invalid -> unchanged
         copy_network_unit('24-rps-cpu-invalid.link')
         udevadm_trigger('/sys/class/net/dummy98')
+        self.networkctl_check_unit('dummy98', '12-dummy', '12-dummy', '24-rps-cpu-invalid')
         output = check_output('cat /sys/class/net/dummy98/queues/rx-0/rps_cpus')
         print(output)
         self.assertEqual(int(output.replace(',', ''), base=16), 1)
@@ -2685,6 +2814,9 @@ class NetworkdL2TPTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('test1:routable', 'l2tp-ses1:degraded', 'l2tp-ses2:degraded')
+        self.networkctl_check_unit('test1', '11-dummy', '25-l2tp-dummy')
+        self.networkctl_check_unit('l2tp-ses1', '25-l2tp-udp', '25-l2tp')
+        self.networkctl_check_unit('l2tp-ses2', '25-l2tp-udp', '25-l2tp')
 
         output = check_output('ip l2tp show tunnel tunnel_id 10')
         print(output)
@@ -2713,6 +2845,9 @@ class NetworkdL2TPTests(unittest.TestCase, Utilities):
         start_networkd()
 
         self.wait_online('test1:routable', 'l2tp-ses3:degraded', 'l2tp-ses4:degraded')
+        self.networkctl_check_unit('test1', '11-dummy', '25-l2tp-dummy')
+        self.networkctl_check_unit('l2tp-ses3', '25-l2tp-ip', '25-l2tp')
+        self.networkctl_check_unit('l2tp-ses4', '25-l2tp-ip', '25-l2tp')
 
         output = check_output('ip l2tp show tunnel tunnel_id 10')
         print(output)