[PATCH net-next v3 0/2] netdevsim: support setting a permanent address

[PATCH net-next v3 0/2] netdevsim: support setting a permanent address

[Toke Høiland-Jørgensen]

Network management daemons that match on the device permanent address
currently have no virtual interface types to test against.
NetworkManager, in particular, has carried an out of tree patch to set
the permanent address on netdevsim devices to use in its CI for this
purpose.

This series adds support to netdevsim to set a permanent address on port
creation, and adds a test script to test setting and getting of the
different L2 address types.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
Changes in v3:
- Fix shellcheck warnings in test script
- Link to v2: https://lore.kernel.org/r/20250702-netdevsim-perm_addr-v2-0-66359a6288f0@redhat.com

Changes in v2:
- Set the permanent address on port creation instead of through debugfs
- Add test script for testing L2 address setting and getting
- Link to v1: https://lore.kernel.org/r/20250203-netdevsim-perm_addr-v1-1-10084bc93044@redhat.com

---
Toke Høiland-Jørgensen (2):
      net: netdevsim: Support setting dev->perm_addr on port creation
      selftests: net: add netdev-l2addr.sh for testing L2 address functionality

 drivers/net/netdevsim/bus.c                  | 22 +++++++--
 drivers/net/netdevsim/dev.c                  | 14 +++---
 drivers/net/netdevsim/netdev.c               |  9 ++--
 drivers/net/netdevsim/netdevsim.h            |  9 ++--
 tools/testing/selftests/net/Makefile         |  1 +
 tools/testing/selftests/net/lib.sh           | 23 ++++++++++
 tools/testing/selftests/net/netdev-l2addr.sh | 69 ++++++++++++++++++++++++++++
 7 files changed, 129 insertions(+), 18 deletions(-)
---
base-commit: e96ee511c906c59b7c4e6efd9d9b33917730e000
change-id: 20250128-netdevsim-perm_addr-5fca47a08157

[PATCH net-next v3 1/2] net: netdevsim: Support setting dev->perm_addr on port creation

[Toke Høiland-Jørgensen]

Network management daemons that match on the device permanent address
currently have no virtual interface types to test against.
NetworkManager, in particular, has carried an out of tree patch to set
the permanent address on netdevsim devices to use in its CI for this
purpose.

To support this use case, support setting netdev->perm_addr when
creating a netdevsim port.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 drivers/net/netdevsim/bus.c       | 22 ++++++++++++++++++----
 drivers/net/netdevsim/dev.c       | 14 +++++++-------
 drivers/net/netdevsim/netdev.c    |  9 ++++++---
 drivers/net/netdevsim/netdevsim.h |  9 +++++----
 4 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index 64c0cdd31bf85468ce4fa2b2af5c8aff4cfba897..422b3683afe154d9055878a601f95d7b39b30aaf 100644
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -66,17 +66,31 @@ new_port_store(struct device *dev, struct device_attribute *attr,
 	       const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
+	u8 eth_addr[ETH_ALEN] = {};
 	unsigned int port_index;
+	bool addr_set = false;
 	int ret;
 
 	/* Prevent to use nsim_bus_dev before initialization. */
 	if (!smp_load_acquire(&nsim_bus_dev->init))
 		return -EBUSY;
-	ret = kstrtouint(buf, 0, &port_index);
-	if (ret)
-		return ret;
 
-	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
+	ret = sscanf(buf, "%u %hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &port_index,
+		     &eth_addr[0], &eth_addr[1], &eth_addr[2], &eth_addr[3],
+		     &eth_addr[4], &eth_addr[5]);
+	switch (ret) {
+	case 7:
+		addr_set = true;
+		fallthrough;
+	case 1:
+		break;
+	default:
+		pr_err("Format for adding new port is \"id [perm_addr]\" (uint MAC).\n");
+		return -EINVAL;
+	}
+
+	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index,
+				addr_set ? eth_addr : NULL);
 	return ret ? ret : count;
 }
 
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 3e0b61202f0c9824952040c8d4c79eb8775954c6..107b106be516bbc97735e93643a7f7cf3bfc0a73 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -576,7 +576,7 @@ static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev)
 
 static int
 __nsim_dev_port_add(struct nsim_dev *nsim_dev, enum nsim_dev_port_type type,
-		    unsigned int port_index);
+		    unsigned int port_index, u8 perm_addr[ETH_ALEN]);
 static void __nsim_dev_port_del(struct nsim_dev_port *nsim_dev_port);
 
 static int nsim_esw_legacy_enable(struct nsim_dev *nsim_dev,
@@ -600,7 +600,7 @@ static int nsim_esw_switchdev_enable(struct nsim_dev *nsim_dev,
 	int i, err;
 
 	for (i = 0; i < nsim_dev_get_vfs(nsim_dev); i++) {
-		err = __nsim_dev_port_add(nsim_dev, NSIM_DEV_PORT_TYPE_VF, i);
+		err = __nsim_dev_port_add(nsim_dev, NSIM_DEV_PORT_TYPE_VF, i, NULL);
 		if (err) {
 			NL_SET_ERR_MSG_MOD(extack, "Failed to initialize VFs' netdevsim ports");
 			pr_err("Failed to initialize VF id=%d. %d.\n", i, err);
@@ -1353,7 +1353,7 @@ static const struct devlink_ops nsim_dev_devlink_ops = {
 #define NSIM_DEV_TEST1_DEFAULT true
 
 static int __nsim_dev_port_add(struct nsim_dev *nsim_dev, enum nsim_dev_port_type type,
-			       unsigned int port_index)
+			       unsigned int port_index, u8 perm_addr[ETH_ALEN])
 {
 	struct devlink_port_attrs attrs = {};
 	struct nsim_dev_port *nsim_dev_port;
@@ -1390,7 +1390,7 @@ static int __nsim_dev_port_add(struct nsim_dev *nsim_dev, enum nsim_dev_port_typ
 	if (err)
 		goto err_dl_port_unregister;
 
-	nsim_dev_port->ns = nsim_create(nsim_dev, nsim_dev_port);
+	nsim_dev_port->ns = nsim_create(nsim_dev, nsim_dev_port, perm_addr);
 	if (IS_ERR(nsim_dev_port->ns)) {
 		err = PTR_ERR(nsim_dev_port->ns);
 		goto err_port_debugfs_exit;
@@ -1446,7 +1446,7 @@ static int nsim_dev_port_add_all(struct nsim_dev *nsim_dev,
 	int i, err;
 
 	for (i = 0; i < port_count; i++) {
-		err = __nsim_dev_port_add(nsim_dev, NSIM_DEV_PORT_TYPE_PF, i);
+		err = __nsim_dev_port_add(nsim_dev, NSIM_DEV_PORT_TYPE_PF, i, NULL);
 		if (err)
 			goto err_port_del_all;
 	}
@@ -1702,7 +1702,7 @@ __nsim_dev_port_lookup(struct nsim_dev *nsim_dev, enum nsim_dev_port_type type,
 }
 
 int nsim_drv_port_add(struct nsim_bus_dev *nsim_bus_dev, enum nsim_dev_port_type type,
-		      unsigned int port_index)
+		      unsigned int port_index, u8 perm_addr[ETH_ALEN])
 {
 	struct nsim_dev *nsim_dev = dev_get_drvdata(&nsim_bus_dev->dev);
 	int err;
@@ -1711,7 +1711,7 @@ int nsim_drv_port_add(struct nsim_bus_dev *nsim_bus_dev, enum nsim_dev_port_type
 	if (__nsim_dev_port_lookup(nsim_dev, type, port_index))
 		err = -EEXIST;
 	else
-		err = __nsim_dev_port_add(nsim_dev, type, port_index);
+		err = __nsim_dev_port_add(nsim_dev, type, port_index, perm_addr);
 	devl_unlock(priv_to_devlink(nsim_dev));
 	return err;
 }
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index e36d3e846c2dc314182efd1af03b59270397b007..f316e44130f722759f0ac4e5baac6a2f6956dc7d 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -998,8 +998,9 @@ static void nsim_exit_netdevsim(struct netdevsim *ns)
 	mock_phc_destroy(ns->phc);
 }
 
-struct netdevsim *
-nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
+struct netdevsim *nsim_create(struct nsim_dev *nsim_dev,
+			      struct nsim_dev_port *nsim_dev_port,
+			      u8 perm_addr[ETH_ALEN])
 {
 	struct net_device *dev;
 	struct netdevsim *ns;
@@ -1010,6 +1011,9 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 	if (!dev)
 		return ERR_PTR(-ENOMEM);
 
+	if (perm_addr)
+		memcpy(dev->perm_addr, perm_addr, ETH_ALEN);
+
 	dev_net_set(dev, nsim_dev_net(nsim_dev));
 	ns = netdev_priv(dev);
 	ns->netdev = dev;
@@ -1031,7 +1035,6 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 	ns->qr_dfs = debugfs_create_file("queue_reset", 0200,
 					 nsim_dev_port->ddir, ns,
 					 &nsim_qreset_fops);
-
 	return ns;
 
 err_free_netdev:
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 4a0c48c7a384e2036883c84dc847b82f992f1481..3a8b5510ec2914204beb15247ab60a5d9933f48d 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -143,8 +143,9 @@ struct netdevsim {
 	struct netdev_net_notifier nn;
 };
 
-struct netdevsim *
-nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port);
+struct netdevsim *nsim_create(struct nsim_dev *nsim_dev,
+			      struct nsim_dev_port *nsim_dev_port,
+			      u8 perm_addr[ETH_ALEN]);
 void nsim_destroy(struct netdevsim *ns);
 bool netdev_is_nsim(struct net_device *dev);
 
@@ -361,8 +362,8 @@ void nsim_dev_exit(void);
 int nsim_drv_probe(struct nsim_bus_dev *nsim_bus_dev);
 void nsim_drv_remove(struct nsim_bus_dev *nsim_bus_dev);
 int nsim_drv_port_add(struct nsim_bus_dev *nsim_bus_dev,
-		      enum nsim_dev_port_type type,
-		      unsigned int port_index);
+		      enum nsim_dev_port_type type, unsigned int port_index,
+		      u8 perm_addr[ETH_ALEN]);
 int nsim_drv_port_del(struct nsim_bus_dev *nsim_bus_dev,
 		      enum nsim_dev_port_type type,
 		      unsigned int port_index);

-- 
2.50.0

Re: [PATCH net-next v3 1/2] net: netdevsim: Support setting dev->perm_addr on port creation

[Simon Horman]

On Sun, Jul 06, 2025 at 04:45:31PM +0200, Toke Høiland-Jørgensen wrote:
> Network management daemons that match on the device permanent address
> currently have no virtual interface types to test against.
> NetworkManager, in particular, has carried an out of tree patch to set
> the permanent address on netdevsim devices to use in its CI for this
> purpose.
> 
> To support this use case, support setting netdev->perm_addr when
> creating a netdevsim port.
> 
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net-next v3 1/2] net: netdevsim: Support setting dev->perm_addr on port creation

[Jakub Kicinski]

On Sun, 06 Jul 2025 16:45:31 +0200 Toke Høiland-Jørgensen wrote:
> +	ret = sscanf(buf, "%u %hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &port_index,
> +		     &eth_addr[0], &eth_addr[1], &eth_addr[2], &eth_addr[3],
> +		     &eth_addr[4], &eth_addr[5]);
> +	switch (ret) {
> +	case 7:
> +		addr_set = true;
> +		fallthrough;

Feels like we should run is_valid_ether_addr() over the address.
-- 
pw-bot: cr

[PATCH net-next v3 2/2] selftests: net: add netdev-l2addr.sh for testing L2 address functionality

[Toke Høiland-Jørgensen]

Add a new test script to the network selftests which tests getting and
setting of layer 2 addresses through netlink, including the newly added
support for setting a permaddr on netdevsim devices.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 tools/testing/selftests/net/Makefile         |  1 +
 tools/testing/selftests/net/lib.sh           | 23 ++++++++++
 tools/testing/selftests/net/netdev-l2addr.sh | 69 ++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+)

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 54377659652907af7232907e570eea2a9c5ba3dc..66a3ef221ad758d7844034c66a1dff4497b1ab54 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -63,6 +63,7 @@ TEST_PROGS += ip_local_port_range.sh
 TEST_PROGS += rps_default_mask.sh
 TEST_PROGS += big_tcp.sh
 TEST_PROGS += netns-sysctl.sh
+TEST_PROGS += netdev-l2addr.sh
 TEST_PROGS_EXTENDED := toeplitz_client.sh toeplitz.sh xfrm_policy_add_speed.sh
 TEST_GEN_FILES =  socket nettest
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any
diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
index ff0dbe23e8e0c8d3a66159d9b82fdc1fc5d4804d..f4c3c90bd89acd3ee060b76d53afb43499a35a64 100644
--- a/tools/testing/selftests/net/lib.sh
+++ b/tools/testing/selftests/net/lib.sh
@@ -240,6 +240,29 @@ create_netdevsim() {
     echo nsim$id
 }
 
+create_netdevsim_port() {
+    local nsim_id="$1"
+    local ns="$2"
+    local port_id="$3"
+    local perm_addr="$4"
+    local orig_dev
+    local new_dev
+    local nsim_path
+
+    nsim_path="/sys/bus/netdevsim/devices/netdevsim$nsim_id"
+
+    echo "$port_id $perm_addr" | ip netns exec "$ns" tee "$nsim_path"/new_port > /dev/null
+
+    orig_dev=$(ip netns exec "$ns" find "$nsim_path"/net/ -maxdepth 1 -name 'e*' | tail -n 1)
+    orig_dev=$(basename "$orig_dev")
+    new_dev="nsim${nsim_id}p$port_id"
+
+    ip -netns "$ns" link set dev "$orig_dev" name "$new_dev"
+    ip -netns "$ns" link set dev "$new_dev" up
+
+    echo "$new_dev"
+}
+
 # Remove netdevsim with given id.
 cleanup_netdevsim() {
     local id="$1"
diff --git a/tools/testing/selftests/net/netdev-l2addr.sh b/tools/testing/selftests/net/netdev-l2addr.sh
new file mode 100755
index 0000000000000000000000000000000000000000..a53f33ee368c2e59b1a867d5d1fdb391db1b67a8
--- /dev/null
+++ b/tools/testing/selftests/net/netdev-l2addr.sh
@@ -0,0 +1,69 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+source lib.sh
+set -o pipefail
+
+NSIM_ADDR=2025
+TEST_ADDR="d0:be:d0:be:d0:00"
+
+RET_CODE=0
+
+cleanup() {
+    cleanup_netdevsim "$NSIM_ADDR"
+    cleanup_ns "$NS"
+}
+
+trap cleanup EXIT
+
+fail() {
+    echo "ERROR: ${1:-unexpected return code} (ret: $_)" >&2
+    RET_CODE=1
+}
+
+get_addr()
+{
+    local found=0
+    local type="$1"
+    local dev="$2"
+    local ns="$3"
+    local output
+
+    output=$(ip -n "$ns" link show dev "$dev" | grep "link/")
+
+    for k in $output; do
+        if [ "$found" -eq "1" ]; then
+            echo "$k"
+            return 0
+        fi
+        if [[ "$k" == "$type" ]]; then
+            found=1
+        fi
+    done
+
+    return 1
+}
+
+setup_ns NS
+
+nsim=$(create_netdevsim $NSIM_ADDR "$NS")
+
+get_addr link/ether "$nsim" "$NS" >/dev/null || fail "Couldn't get ether addr"
+get_addr brd "$nsim" "$NS" >/dev/null || fail "Couldn't get brd addr"
+get_addr perm "$nsim" "$NS" && fail "Found perm_addr without setting it"
+
+ip -n "$NS" link set dev "$nsim" address "$TEST_ADDR"
+ip -n "$NS" link set dev "$nsim" brd "$TEST_ADDR"
+
+[[ "$(get_addr link/ether "$nsim" "$NS")" == "$TEST_ADDR" ]] || fail "Couldn't set ether addr"
+[[ "$(get_addr brd "$nsim" "$NS")" == "$TEST_ADDR" ]] || fail "Couldn't set brd addr"
+
+nsim_port=$(create_netdevsim_port "$NSIM_ADDR" "$NS" 2 "$TEST_ADDR")
+
+get_addr link/ether "$nsim_port" "$NS" >/dev/null || fail "Couldn't get ether addr"
+get_addr brd "$nsim_port" "$NS" >/dev/null || fail "Couldn't get brd addr"
+[[ "$(get_addr permaddr "$nsim_port" "$NS")" == "$TEST_ADDR" ]] || fail "Couldn't get permaddr"
+
+cleanup_netdevsim "$NSIM_ADDR" "$NS"
+
+exit $RET_CODE

-- 
2.50.0

Re: [PATCH net-next v3 2/2] selftests: net: add netdev-l2addr.sh for testing L2 address functionality

[Simon Horman]

On Sun, Jul 06, 2025 at 04:45:32PM +0200, Toke Høiland-Jørgensen wrote:
> Add a new test script to the network selftests which tests getting and
> setting of layer 2 addresses through netlink, including the newly added
> support for setting a permaddr on netdevsim devices.
> 
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net-next v3 2/2] selftests: net: add netdev-l2addr.sh for testing L2 address functionality

[Jakub Kicinski]

On Sun, 06 Jul 2025 16:45:32 +0200 Toke Høiland-Jørgensen wrote:
> +    output=$(ip -n "$ns" link show dev "$dev" | grep "link/")

Please use -j and jq