136 lines
3.8 KiB
C
Executable File
136 lines
3.8 KiB
C
Executable File
/*
|
|
* Copyright (C) 2017 Pengutronix, Juergen Borleis <jbe@pengutronix.de>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
*/
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "dsa_priv.h"
|
|
|
|
/* To define the outgoing port and to discover the incoming port a regular
|
|
* VLAN tag is used by the LAN9303. But its VID meaning is 'special':
|
|
*
|
|
* Dest MAC Src MAC TAG Type
|
|
* ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 | 1 2 |...
|
|
* |<------->|
|
|
* TAG:
|
|
* |<------------->|
|
|
* | 1 2 | 3 4 |
|
|
* TPID VID
|
|
* 0x8100
|
|
*
|
|
* VID bit 3 indicates a request for an ALR lookup.
|
|
*
|
|
* If VID bit 3 is zero, then bits 0 and 1 specify the destination port
|
|
* (0, 1, 2) or broadcast (3) or the source port (1, 2).
|
|
*
|
|
* VID bit 4 is used to specify if the STP port state should be overridden.
|
|
* Required when no forwarding between the external ports should happen.
|
|
*/
|
|
|
|
#define LAN9303_TAG_LEN 4
|
|
|
|
static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev)
|
|
{
|
|
struct dsa_slave_priv *p = netdev_priv(dev);
|
|
u16 *lan9303_tag;
|
|
|
|
/* insert a special VLAN tag between the MAC addresses
|
|
* and the current ethertype field.
|
|
*/
|
|
if (skb_cow_head(skb, LAN9303_TAG_LEN) < 0) {
|
|
dev_dbg(&dev->dev,
|
|
"Cannot make room for the special tag. Dropping packet\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* provide 'LAN9303_TAG_LEN' bytes additional space */
|
|
skb_push(skb, LAN9303_TAG_LEN);
|
|
|
|
/* make room between MACs and Ether-Type */
|
|
memmove(skb->data, skb->data + LAN9303_TAG_LEN, 2 * ETH_ALEN);
|
|
|
|
lan9303_tag = (u16 *)(skb->data + 2 * ETH_ALEN);
|
|
lan9303_tag[0] = htons(ETH_P_8021Q);
|
|
lan9303_tag[1] = htons(p->dp->index | BIT(4));
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev,
|
|
struct packet_type *pt)
|
|
{
|
|
u16 *lan9303_tag;
|
|
struct dsa_switch_tree *dst = dev->dsa_ptr;
|
|
struct dsa_switch *ds;
|
|
unsigned int source_port;
|
|
|
|
ds = dst->ds[0];
|
|
|
|
if (unlikely(!ds)) {
|
|
dev_warn_ratelimited(&dev->dev, "Dropping packet, due to missing DSA switch device\n");
|
|
return NULL;
|
|
}
|
|
|
|
if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) {
|
|
dev_warn_ratelimited(&dev->dev,
|
|
"Dropping packet, cannot pull\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* '->data' points into the middle of our special VLAN tag information:
|
|
*
|
|
* ~ MAC src | 0x81 | 0x00 | 0xyy | 0xzz | ether type
|
|
* ^
|
|
* ->data
|
|
*/
|
|
lan9303_tag = (u16 *)(skb->data - 2);
|
|
|
|
if (lan9303_tag[0] != htons(ETH_P_8021Q)) {
|
|
dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid VLAN marker\n");
|
|
return NULL;
|
|
}
|
|
|
|
source_port = ntohs(lan9303_tag[1]) & 0x3;
|
|
|
|
if (source_port >= ds->num_ports) {
|
|
dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n");
|
|
return NULL;
|
|
}
|
|
|
|
if (unlikely(ds->cpu_port_mask & BIT(source_port)))
|
|
return NULL;
|
|
|
|
if (!ds->ports[source_port].netdev) {
|
|
dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid netdev or device\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* remove the special VLAN tag between the MAC addresses
|
|
* and the current ethertype field.
|
|
*/
|
|
skb_pull_rcsum(skb, 2 + 2);
|
|
memmove(skb->data - ETH_HLEN, skb->data - (ETH_HLEN + LAN9303_TAG_LEN),
|
|
2 * ETH_ALEN);
|
|
|
|
/* forward the packet to the dedicated interface */
|
|
skb->dev = ds->ports[source_port].netdev;
|
|
|
|
return skb;
|
|
}
|
|
|
|
const struct dsa_device_ops lan9303_netdev_ops = {
|
|
.xmit = lan9303_xmit,
|
|
.rcv = lan9303_rcv,
|
|
};
|