path: root/net/bridge/br_switchdev.c

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

#include "br_private.h"

static struct static_key_false br_switchdev_tx_fwd_offload;

static bool nbp_switchdev_can_offload_tx_fwd(const struct net_bridge_port *p,
					     const struct sk_buff *skb)
{
	if (!static_branch_unlikely(&br_switchdev_tx_fwd_offload))
		return false;

	if (br_multicast_igmp_type(skb))
		return false;

	return (p->flags & BR_TX_FWD_OFFLOAD) &&
	       (p->hwdom != BR_INPUT_SKB_CB(skb)->src_hwdom);
}

bool br_switchdev_frame_uses_tx_fwd_offload(struct sk_buff *skb)
{
	if (!static_branch_unlikely(&br_switchdev_tx_fwd_offload))
		return false;

	return BR_INPUT_SKB_CB(skb)->tx_fwd_offload;
}

void br_switchdev_frame_set_offload_fwd_mark(struct sk_buff *skb)
{
	skb->offload_fwd_mark = br_switchdev_frame_uses_tx_fwd_offload(skb);
}

/* Mark the frame for TX forwarding offload if this egress port supports it */
void nbp_switchdev_frame_mark_tx_fwd_offload(const struct net_bridge_port *p,
					     struct sk_buff *skb)
{
	if (nbp_switchdev_can_offload_tx_fwd(p, skb))
		BR_INPUT_SKB_CB(skb)->tx_fwd_offload = true;
}

/* Lazily adds the hwdom of the egress bridge port to the bit mask of hwdoms
 * that the skb has been already forwarded to, to avoid further cloning to
 * other ports in the same hwdom by making nbp_switchdev_allowed_egress()
 * return false.
 */
void nbp_switchdev_frame_mark_tx_fwd_to_hwdom(const struct net_bridge_port *p,
					      struct sk_buff *skb)
{
	if (nbp_switchdev_can_offload_tx_fwd(p, skb))
		set_bit(p->hwdom, &BR_INPUT_SKB_CB(skb)->fwd_hwdoms);
}

void nbp_switchdev_frame_mark(const struct net_bridge_port *p,
			      struct sk_buff *skb)
{
	if (p->hwdom)
		BR_INPUT_SKB_CB(skb)->src_hwdom = p->hwdom;
}

bool nbp_switchdev_allowed_egress(const struct net_bridge_port *p,
				  const struct sk_buff *skb)
{
	struct br_input_skb_cb *cb = BR_INPUT_SKB_CB(skb);

	return !test_bit(p->hwdom, &cb->fwd_hwdoms) &&
		(!skb->offload_fwd_mark || cb->src_hwdom != p->hwdom);
}

/* Flags that can be offloaded to hardware */
#define BR_PORT_FLAGS_HW_OFFLOAD (BR_LEARNING | BR_FLOOD | BR_PORT_MAB | \
				  BR_MCAST_FLOOD | BR_BCAST_FLOOD | BR_PORT_LOCKED | \
				  BR_HAIRPIN_MODE | BR_ISOLATED | BR_MULTICAST_TO_UNICAST)

int br_switchdev_set_port_flag(struct net_bridge_port *p,
			       unsigned long flags,
			       unsigned long mask,
			       struct netlink_ext_ack *extack)
{
	struct switchdev_attr attr = {
		.orig_dev = p->dev,
	};
	struct switchdev_notifier_port_attr_info info = {
		.attr = &attr,
	};
	int err;

	mask &= BR_PORT_FLAGS_HW_OFFLOAD;
	if (!mask)
		return 0;

	attr.id = SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS;
	attr.u.brport_flags.val = flags;
	attr.u.brport_flags.mask = mask;

	/* We run from atomic context here */
	err = call_switchdev_notifiers(SWITCHDEV_PORT_ATTR_SET, p->dev,
				       &info.info, extack);
	err = notifier_to_errno(err);
	if (err == -EOPNOTSUPP)
		return 0;

	if (err) {
		NL_SET_ERR_MSG_WEAK_MOD(extack,
					"bridge flag offload is not supported");
		return -EOPNOTSUPP;
	}

	attr.id = SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS;
	attr.flags = SWITCHDEV_F_DEFER;

	err = switchdev_port_attr_set(p->dev, &attr, extack);
	if (err) {
		NL_SET_ERR_MSG_WEAK_MOD(extack,
					"error setting offload flag on port");
		return err;
	}

	return 0;
}

static void br_switchdev_fdb_populate(struct net_bridge *br,
				      struct switchdev_notifier_fdb_info *item,
				      const struct net_bridge_fdb_entry *fdb,
				      const void *ctx)
{
	const struct net_bridge_port *p = READ_ONCE(fdb->dst);

	item->addr = fdb->key.addr.addr;
	item->vid = fdb->key.vlan_id;
	item->added_by_user = test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
	item->offloaded = test_bit(BR_FDB_OFFLOADED, &fdb->flags);
	item->is_local = test_bit(BR_FDB_LOCAL, &fdb->flags);
	item->locked = false;
	item->info.dev = (!p || item->is_local) ? br->dev : p->dev;
	item->info.ctx = ctx;
}

void
br_switchdev_fdb_notify(struct net_bridge *br,
			const struct net_bridge_fdb_entry *fdb, int type)
{
	struct switchdev_notifier_fdb_info item;

	if (test_bit(BR_FDB_LOCKED, &fdb->flags))
		return;

	/* Entries with these flags were created using ndm_state == NUD_REACHABLE,
	 * ndm_flags == NTF_MASTER( | NTF_STICKY), ext_flags == 0 by something
	 * equivalent to 'bridge fdb add ... master dynamic (stick