path: root/net/bridge/br_vlan.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <net/switchdev.h>

#include "br_private.h"
#include "br_private_tunnel.h"

static void nbp_vlan_set_vlan_dev_state(struct net_bridge_port *p, u16 vid);

static inline int br_vlan_cmp(struct rhashtable_compare_arg *arg,
			      const void *ptr)
{
	const struct net_bridge_vlan *vle = ptr;
	u16 vid = *(u16 *)arg->key;

	return vle->vid != vid;
}

static const struct rhashtable_params br_vlan_rht_params = {
	.head_offset = offsetof(struct net_bridge_vlan, vnode),
	.key_offset = offsetof(struct net_bridge_vlan, vid),
	.key_len = sizeof(u16),
	.nelem_hint = 3,
	.max_size = VLAN_N_VID,
	.obj_cmpfn = br_vlan_cmp,
	.automatic_shrinking = true,
};

static struct net_bridge_vlan *br_vlan_lookup(struct rhashtable *tbl, u16 vid)
{
	return rhashtable_lookup_fast(tbl, &vid, br_vlan_rht_params);
}

static bool __vlan_add_pvid(struct net_bridge_vlan_group *vg, u16 vid)
{
	if (vg->pvid == vid)
		return false;

	smp_wmb();
	vg->pvid = vid;

	return true;
}

static bool __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
{
	if (vg->pvid != vid)
		return false;

	smp_wmb();
	vg->pvid = 0;

	return true;
}

/* return true if anything changed, false otherwise */
static bool __vlan_add_flags(struct net_bridge_vlan *v, u16 flags)
{
	struct net_bridge_vlan_group *vg;
	u16 old_flags = v->flags;
	bool ret;

	if (br_vlan_is_master(v))
		vg = br_vlan_group(v->br);
	else
		vg = nbp_vlan_group(v->port);

	if (flags & BRIDGE_VLAN_INFO_PVID)
		ret = __vlan_add_pvid(vg, v->vid);
	else
		ret = __vlan_delete_pvid(vg, v->vid);

	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
		v->flags |= BRIDGE_VLAN_INFO_UNTAGGED;
	else
		v->flags &= ~BRIDGE_VLAN_INFO_UNTAGGED;

	return ret || !!(old_flags ^ v->flags);
}

static int __vlan_vid_add(struct net_device *dev, struct net_bridge *br,
			  struct net_bridge_vlan *v, u16 flags,
			  struct netlink_ext_ack *extack)
{
	int err;

	/* Try switchdev op first. In case it is not supported, fallback to
	 * 8021q add.
	 */
	err = br_switchdev_port_vlan_add(dev, v->vid, flags, extack);
	if (err == -EOPNOTSUPP)
		return vlan_vid_add(dev, br->vlan_proto, v->vid);
	v->priv_flags |= BR_VLFLAG_ADDED_BY_SWITCHDEV;
	return err;
}

static void __vlan_add_list(struct net_bridge_vlan *v)
{
	struct net_bridge_vlan_group *vg;
	struct list_head *headp, *hpos;
	struct net_bridge_vlan *vent;

	if (br_vlan_is_master(v))
		vg = br_vlan_group(v->br);
	else
		vg = nbp_vlan_group(v->port);

	headp = &vg->vlan_list;
	list_for_each_prev(hpos, headp) {
		vent = list_entry(hpos, struct net_bridge_vlan, vlist);
		if (v->vid < vent->vid)
			continue;
		else
			break;
	}
	list_add_rcu(&v->vlist, hpos);
}

static void __vlan_del_list(struct net_bridge_vlan *v)
{
	list_del_rcu(&v->vlist);
}

static int __vlan_vid_del(struct net_device *dev, struct net_bridge *br,
			  const struct net_bridge_vlan *v)
{
	int err;

	/* Try switchdev op first. In case it is not supported, fallback to
	 * 8021q del.
	 */
	err = br_switchdev_port_vlan_del(dev, v->vid);
	if (!(v->priv_flags & BR_VLFLAG_ADDED_BY_SWITCHDEV))
		vlan_vid_del(dev, br->vlan_proto, v->vid);
	return err == -EOPNOTSUPP ? 0 : err;
}

/* Returns a master vlan, if it didn't exist it gets created. In all cases a
 * a reference is taken to the master vlan before returning.
 */
static struct net_bridge_vlan *
br_vlan_get_master(struct net_bridge *br, u16 vid,
		   struct netlink_ext_ack *extack)
{
	struct net_bridge_vlan_group *vg;
	struct net_bridge_vlan *masterv;

	vg = br_vlan_group(br);
	masterv = br_vlan_find(vg, vid);
	if (!masterv) {
		bool changed;

		/* missing global ctx, create it now */
		if (br_vlan_add(br, vid, 0, &changed, extack))
			return NULL;
		masterv = br_vlan_find(vg, vid);
		if (WARN_ON(!masterv))
			return NULL;
		refcount_set(&masterv->refcnt, 1);
		return masterv;
	}
	refcount_inc(&masterv->refcnt);

	return masterv;
}

static void br_master_vlan_rcu_free(struct rcu_head *rcu)
{
	struct net_bridge_vlan *v;

	v = container_of(rcu, struct net_bridge_vlan, rcu);
	WARN_ON(!br_vlan_is_master(v));
	free_percpu(v->stats);
	v->stats = NULL;
	kfree(v);
}

static void br_vlan_put_master(struct net_bridge_vlan *masterv)
{
	struct net_bridge_vlan_group *vg;

	if (!br_vlan_is_master(masterv))
		return;

	vg = br_vlan_group(masterv->br);
	if (refcount_dec_and_test(&masterv->refcnt)) {
		rhashtable_remove_fast(&vg->vlan_hash,
				       &masterv->vnode, br_vlan_rht_params);
		__vlan_del_list(masterv);
		call_rcu(&masterv->rcu, br_master_vlan_rcu_free);
	}
}

static void nbp_vlan_rcu_free(struct rcu_head *rcu)
{
	struct net_bridge_vlan *v;

	v = container_of(rcu, struct net_bridge_vlan, rcu);
	WARN_ON(br_vlan_is_master(v));
	/* if we had per-port stats configured then free them here */
	if (v->priv_flags & BR_VLFLAG_PER_PORT_STATS)
		free_percpu(v->stats);
	v->stats = NULL;
	kfree(v);
}

/* This is the shared VLAN add function which works for both ports and bridge
 * devices. There are four possible calls to this function in terms of the
 * vlan entry type:
 * 1. vlan is being added on a port (no master flags, global entry exists)
 * 2. vlan is being added on a bridge (both master and brentry flags)
 * 3. vlan is being added on a port, but a global entry didn't exist which
 *    is being created right now (master flag set, brentry flag unset), the
 *    global entry is used for global per-vlan features, but not for filtering
 * 4. same as 3 but with both master and brentry flags set so the entry
 *    will be used for filtering in both the port and the bridge
 */
static int __vlan_add(struct net_bridge_vlan *v, u16 flags,
		      struct netlink_ext_ack *extack)
{
	struct net_bridge_vlan *masterv = NULL;
	struct net_bridge_port *p = NULL;
	struct net_bridge_vlan_group *vg;
	struct net_device *dev;
	struct net_bridge *br;
	int err;

	if (br_vlan_is_master(v)) {
		br = v->br;
		dev = br->dev;
		vg = br_vlan_group(br);
	} else {
		p = v->port;
		br = p->br;
		dev = p->dev;
		vg = nbp_vlan_group(p);
	}

	if (p) {
		/* Add VLAN to the device filter if it is supported.
		 * This ensures tagged traffic enters the bridge when
		 * promiscuous mode is disabled by br_manage_promisc().
		 */
		err = __vlan_vid_add(dev, br, v, flags, extack);
		if (err)
			goto out;

		/* need to work on the master vlan too */
		if (flags & BRIDGE_VLAN_INFO_MASTER) {
			bool changed;

			err = br_vlan_add(br, v->vid,
					  flags | BRIDGE_VLAN_INFO_BRENTRY,
					  &changed, extack);
			if (err)
				goto out_filt;
		}

		masterv = br_vlan_get_master(br, v->vid, extack);
		if (!masterv)
			goto out_filt;
		v->brvlan = masterv;
		if (br_opt_get(br, BROPT_VLAN_STATS_PER_PORT)) {
			v->stats = netdev_alloc_pcpu_stats(struct br_vlan_stats);
			if (!v->stats) {
				err = -ENOMEM;
				goto out_filt;
			}
			v->priv_flags |= BR_VLFLAG_PER_PORT_STATS;
		} else {
			v->stats = masterv->stats;
		}
	} else {
		err = br_switchdev_port_vlan_add(dev, v->vid, flags, extack);
		if (err && err != -EOPNOTSUPP)
			goto out;
	}

	/* Add the dev mac and count the vlan only if it's usable */
	if (br_vlan_should_use(v)) {
		err = br_fdb_insert(br, p, dev->dev_addr, v->vid);
		if (err) {
			br_err(br, "failed insert local address into bridge forwarding table\n");
			goto out_filt;
		}
		vg->num_vlans++;
	}

	err = rhashtable_lookup_insert_fast(&vg->vlan_hash, &v->vnode,
					    br_vlan_rht_params);
	if (err)
		goto out_fdb_insert;

	__vlan_add_list(v);
	__vlan_add_flags(v, flags);

	if (p)
		nbp_vlan_set_vlan_dev_state(p, v->vid);
out:
	return err;

out_fdb_insert:
	if (br_vlan_should_use(v)) {
		br_fdb_find_delete_local(br, p, dev->dev_addr, v->vid);
		vg->num_vlans--;
	}

out_filt:
	if (p) {
		__vlan_vid_del(dev, br, v);
		if (masterv) {
			if (v->stats && masterv->stats != v->stats)
				free_percpu(v->stats);
			v->stats = NULL;

			br_vlan_put_master(masterv);
			v->brvlan = NULL;
		}
	} else {
		br_switchdev_port_vlan_del(dev, v->vid);
	}

	goto out;
}

static int __vlan_del(struct net_bridge_vlan *v)
{
	struct net_bridge_vlan *masterv = v;
	struct net_bridge_vlan_group *vg;
	st