// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
*/
#include <linux/if_vlan.h>
#include <linux/dsa/sja1105.h>
#include <linux/dsa/8021q.h>
#include <linux/packing.h>
#include "dsa_priv.h"
/* Similar to is_link_local_ether_addr(hdr->h_dest) but also covers PTP */
static inline bool sja1105_is_link_local(const struct sk_buff *skb)
{
const struct ethhdr *hdr = eth_hdr(skb);
u64 dmac = ether_addr_to_u64(hdr->h_dest);
if ((dmac & SJA1105_LINKLOCAL_FILTER_A_MASK) ==
SJA1105_LINKLOCAL_FILTER_A)
return true;
if ((dmac & SJA1105_LINKLOCAL_FILTER_B_MASK) ==
SJA1105_LINKLOCAL_FILTER_B)
return true;
return false;
}
static inline bool sja1105_is_meta_frame(const struct sk_buff *skb)
{
const struct ethhdr *hdr = eth_hdr(skb);
u64 smac = ether_addr_to_u64(hdr->h_source);
u64 dmac = ether_addr_to_u64(hdr->h_dest);
if (smac != SJA1105_META_SMAC)
return false;
if (dmac != SJA1105_META_DMAC)
return false;
if (ntohs(hdr->h_proto) != ETH_P_SJA1105_META)
return false;
return true;
}
/* This is the first time the tagger sees the frame on RX.
* Figure out if we can decode it, and if we can, annotate skb->cb with how we
* plan to do that, so we don't need to check again in the rcv function.
*/
static bool sja1105_filter(const struct sk_buff *skb, struct net_device *dev)
{
if (sja1105_is_link_local(skb))
return true;
if (!dsa_port_is_vlan_filtering(dev->dsa_ptr))
return true;
return false;
}
static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct dsa_port *dp = dsa_slave_to_port(netdev);
struct dsa_switch *ds = dp->ds;
u16 tx_vid = dsa_8021q_tx_vid(ds, dp->index);
u8 pcp = skb->priority;
/* Transmitting management traffic does not rely upon switch tagging,
* but instead SPI-installed management routes. Part 2 of this
* is the .port_deferred_xmit driver callback.
*/
if (unlikely(sja1105_is_link_local(skb)))
return dsa_defer_xmit(skb, netdev);
/* If we are under a vlan_filtering bridge, IP termination on
* switch ports based on 802.1Q tags is simply too brittle to
* be passable. So just defer to the dsa_slave_notag_xmit
* implementation.
*/
if (dsa_port_is_vlan_filtering(dp))
return skb;
return dsa_8021q_xmit(skb, netdev, ETH_P_SJA1105,
((pcp << VLAN_PRIO_SHIFT) | tx_vid));
}
static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
struct net_device *netdev,
struct packet_type *pt)
{
int source_port, switch_id;
struct vlan_ethhdr *hdr;
u16 tpid, vid, tci;
bool is_link_local;
bool is_tagged;
hdr = vlan_eth_hdr(skb);
tpid = ntohs(hdr->h_vlan_proto);
is_tagged = (tpid == ETH_P_SJA1105);
is_link_local = sja1105_is_link_local(skb);
skb->offload_fwd_mark = 1;
if (is_tagged) {
/* Normal traffic path. */
tci = ntohs(hdr->h_vlan_TCI);
vid = tci & VLAN_VID_MASK;
source_port = dsa_8021q_rx_source_port(vid);
switch_id = dsa_8021q_rx_switch_id(vid);
skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
} else if (is_link_local) {
/* Management traffic path. Switch embeds the switch ID and
* port ID into bytes of the destination MAC, courtesy of
* the incl_srcpt options.
*/
source_port = hdr->h_dest[3];
switch_id = hdr->h_dest[4];
/* Clear the DMAC bytes that were mangled by the switch */
hdr->h_dest[3] = 0;
hdr->h_dest[4] = 0;
} else {
return NULL;
}
skb->dev = dsa_master_find_slave(netdev, switch_id, source_port);
if (!skb->dev) {
netdev_warn(netdev, "Couldn't decode source port\n");
return NULL;
}
/* Delete/overwrite fake VLAN header, DSA expects to not find
* it there, see dsa_switch_rcv: skb_push(skb, ETH_HLEN).
*/
if (is_tagged)
skb = dsa_8021q_remove_header(skb);
return skb;
}
static struct dsa_device_ops sja1105_netdev_ops = {
.name = "sja1105",
.proto = DSA_TAG_PROTO_SJA1105,
.xmit = sja1105_xmit,
.rcv = sja1105_rcv,
.filter = sja1105_filter,
.overhead = VLAN_HLEN,
};
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SJA1105);
module_dsa_tag_driver(sja1105_netdev_ops);
