path: root/net/8021q/vlan_dev.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- linux-c -*-
 * INET		802.1Q VLAN
 *		Ethernet-type device handling.
 *
 * Authors:	Ben Greear <greearb@candelatech.com>
 *              Please send support related email to: netdev@vger.kernel.org
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 *
 * Fixes:       Mar 22 2001: Martin Bokaemper <mbokaemper@unispherenetworks.com>
 *                - reset skb->pkt_type on incoming packets when MAC was changed
 *                - see that changed MAC is saddr for outgoing packets
 *              Oct 20, 2001:  Ard van Breeman:
 *                - Fix MC-list, finally.
 *                - Flush MC-list on VLAN destroy.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/net_tstamp.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <net/arp.h>
#include <net/macsec.h>

#include "vlan.h"
#include "vlanproc.h"
#include <linux/if_vlan.h>
#include <linux/netpoll.h>

/*
 *	Create the VLAN header for an arbitrary protocol layer
 *
 *	saddr=NULL	means use device source address
 *	daddr=NULL	means leave destination address (eg unresolved arp)
 *
 *  This is called when the SKB is moving down the stack towards the
 *  physical devices.
 */
static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
				unsigned short type,
				const void *daddr, const void *saddr,
				unsigned int len)
{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct vlan_hdr *vhdr;
	unsigned int vhdrlen = 0;
	u16 vlan_tci = 0;
	int rc;

	if (!(vlan->flags & VLAN_FLAG_REORDER_HDR)) {
		vhdr = skb_push(skb, VLAN_HLEN);

		vlan_tci = vlan->vlan_id;
		vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb->priority);
		vhdr->h_vlan_TCI = htons(vlan_tci);

		/*
		 *  Set the protocol type. For a packet of type ETH_P_802_3/2 we
		 *  put the length in here instead.
		 */
		if (type != ETH_P_802_3 && type != ETH_P_802_2)
			vhdr->h_vlan_encapsulated_proto = htons(type);
		else
			vhdr->h_vlan_encapsulated_proto = htons(len);

		skb->protocol = vlan->vlan_proto;
		type = ntohs(vlan->vlan_proto);
		vhdrlen = VLAN_HLEN;
	}

	/* Before delegating work to the lower layer, enter our MAC-address */
	if (saddr == NULL)
		saddr = dev->dev_addr;

	/* Now make the underlying real hard header */
	dev = vlan->real_dev;
	rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
	if (rc > 0)
		rc += vhdrlen;
	return rc;
}

static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv *vlan, struct sk_buff *skb)
{
#ifdef CONFIG_NET_POLL_CONTROLLER
	return netpoll_send_skb(vlan->netpoll, skb);
#else
	BUG();
	return NETDEV_TX_OK;
#endif
}

static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
					    struct net_device *dev)
{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
	unsigned int len;
	int ret;

	/* Handle non-VLAN frames if they are sent to us, for example by DHCP.
	 *
	 * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
	 */
	if (vlan->flags & VLAN_FLAG_REORDER_HDR ||
	    veth->h_vlan_proto != vlan->vlan_proto) {
		u16 vlan_tci;
		vlan_tci = vlan->vlan_id;
		vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb->priority);
		__vlan_hwaccel_put_tag(skb, vlan->vlan_proto, vlan_tci);
	}

	skb->dev = vlan->real_dev;
	len = skb->len;
	if (unlikely(netpoll_tx_running(dev)))
		return vlan_netpoll_send_skb(vlan, skb);

	ret = dev_queue_xmit(skb);

	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
		struct vlan_pcpu_stats *stats;

		stats = this_cpu_ptr(vlan->vlan_pcpu_stats);
		u64_stats_update_begin(&stats->syncp);
		u64_stats_inc(&stats->tx_packets);
		u64_stats_add(&stats->tx_bytes, len);
		u64_stats_update_end(&stats->syncp);
	} else {
		this_cpu_inc(vlan->vlan_pcpu_stats->tx_dropped);
	}

	return ret;
}

static int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
{
	struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
	unsigned int max_mtu = real_dev->mtu;

	if (netif_reduces_vlan_mtu(real_dev))
		max_mtu -= VLAN_HLEN;
	if (max_mtu < new_mtu)
		return -ERANGE;

	WRITE_ONCE(dev->mtu, new_mtu);

	return 0;
}

void vlan_dev_set_ingress_priority(const struct net_device *dev,
				   u32 skb_prio, u16 vlan_prio)
{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);

	if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)<