On 6/25/18 4:30 AM, Chas Williams wrote:
> vlan_changelink silently ignores attempts to change the vlan id
> or protocol id of an existing vlan interface. Implement by adding
> the new vlan id and protocol to the interface's vlan group and then
> removing the old vlan id and protocol from the vlan group.
>
> Signed-off-by: Chas Williams <3ch...@gmail.com>
> ---
> include/linux/netdevice.h | 1 +
> net/8021q/vlan.c | 4 ++--
> net/8021q/vlan.h | 2 ++
> net/8021q/vlan_netlink.c | 38 ++++++++++++++++++++++++++++++++++++++
> net/core/dev.c | 1 +
> 5 files changed, 44 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 3ec9850c7936..a95ae238addf 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -2409,6 +2409,7 @@ enum netdev_cmd {
> NETDEV_CVLAN_FILTER_DROP_INFO,
> NETDEV_SVLAN_FILTER_PUSH_INFO,
> NETDEV_SVLAN_FILTER_DROP_INFO,
> + NETDEV_CHANGEVLAN,
> };
> const char *netdev_cmd_to_name(enum netdev_cmd cmd);
>
you add the new notifier, but do not add any hooks to catch and process it.
Personally, I think it is a bit sketchy to change the vlan id on an
existing device and I suspect it will cause latent errors.
What's your use case for trying to implement the change versus causing
it to generate an unsupported error?
If this patch does get accepted, I believe the mlxsw switchdev driver
will be impacted.
> diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
> index 73a65789271b..b5e0ad1a581a 100644
> --- a/net/8021q/vlan.c
> +++ b/net/8021q/vlan.c
> @@ -51,8 +51,8 @@ const char vlan_version[] = DRV_VERSION;
>
> /* End of global variables definitions. */
>
> -static int vlan_group_prealloc_vid(struct vlan_group *vg,
> - __be16 vlan_proto, u16 vlan_id)
> +int vlan_group_prealloc_vid(struct vlan_group *vg,
> + __be16 vlan_proto, u16 vlan_id)
> {
> struct net_device **array;
> unsigned int pidx, vidx;
> diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
> index 44df1c3df02d..c734dd21d70d 100644
> --- a/net/8021q/vlan.h
> +++ b/net/8021q/vlan.h
> @@ -116,6 +116,8 @@ int register_vlan_dev(struct net_device *dev, struct
> netlink_ext_ack *extack);
> void unregister_vlan_dev(struct net_device *dev, struct list_head *head);
> bool vlan_dev_inherit_address(struct net_device *dev,
> struct net_device *real_dev);
> +int vlan_group_prealloc_vid(struct vlan_group *vg,
> + __be16 vlan_proto, u16 vlan_id);
>
> static inline u32 vlan_get_ingress_priority(struct net_device *dev,
> u16 vlan_tci)
> diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
> index 9b60c1e399e2..ee27781939e0 100644
> --- a/net/8021q/vlan_netlink.c
> +++ b/net/8021q/vlan_netlink.c
> @@ -107,10 +107,48 @@ static int vlan_changelink(struct net_device *dev,
> struct nlattr *tb[],
> struct nlattr *data[],
> struct netlink_ext_ack *extack)
> {
> + struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
> struct ifla_vlan_flags *flags;
> struct ifla_vlan_qos_mapping *m;
> struct nlattr *attr;
> int rem;
> + __be16 vlan_proto = vlan->vlan_proto;
> + u16 vlan_id = vlan->vlan_id;
> +
> + if (data[IFLA_VLAN_ID])
> + vlan_id = nla_get_u16(data[IFLA_VLAN_ID]);
> +
> + if (data[IFLA_VLAN_PROTOCOL])
> + vlan_proto = nla_get_be16(data[IFLA_VLAN_PROTOCOL]);
> +
> + if (vlan->vlan_id != vlan_id || vlan->vlan_proto != vlan_proto) {
> + struct net_device *real_dev = vlan->real_dev;
> + struct vlan_info *vlan_info;
> + struct vlan_group *grp;
> + __be16 old_vlan_proto = vlan->vlan_proto;
> + u16 old_vlan_id = vlan->vlan_id;
> + int err;
> +
> + err = vlan_vid_add(real_dev, vlan_proto, vlan_id);
> + if (err)
> + return err;
> + vlan_info = rtnl_dereference(real_dev->vlan_info);
> + grp = &vlan_info->grp;
> + err = vlan_group_prealloc_vid(grp, vlan_proto, vlan_id);
> + if (err < 0) {
> + vlan_vid_del(real_dev, vlan_proto, vlan_id);
> + return err;
> + }
> + vlan_group_set_device(grp, vlan_proto, vlan_id, dev);
> + vlan->vlan_proto = vlan_proto;
> + vlan->vlan_id = vlan_id;
> +
> + vlan_group_set_device(grp, old_vlan_proto, old_vlan_id, NULL);
> + vlan_vid_del(real_dev, old_vlan_proto, old_vlan_id);
> +
> + err = call_netdevice_notifiers(NETDEV_CHANGEVLAN, dev);
> + notifier_to_errno(err);
> + }
>
> if (data[IFLA_VLAN_FLAGS]) {
> flags = nla_data(data[IFLA_VLAN_FLAGS]);
> diff --git a/net/core/dev.c b/net/core/dev.c
> index a5aa1c7444e6..4bda5d2e3c85 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -1587,6 +1587,7 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
> N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
> N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
> N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
> + N(CHANGEVLAN)
> }
> #undef N
> return "UNKNOWN_NETDEV_EVENT";
>
