4ed70ce9f0
All tagging protocols do the same thing: increment device statistics, make room for the tag to be inserted, create the tag, invoke the parent network device transmit function. In order to prepare for adding netpoll support, which requires the tag creation, but not using the parent network device transmit function, do some little refactoring which eliminates duplication between the 4 tagging protocols supported. We need to return a sk_buff pointer back to the caller because the tag specific transmit function may have to reallocate the original skb (e.g: tag_trailer.c) and this is the one we should be transmitting, not the original sk_buff we were passed. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
/*
|
|
* net/dsa/tag_trailer.c - Trailer tag format handling
|
|
* Copyright (c) 2008-2009 Marvell Semiconductor
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/etherdevice.h>
|
|
#include <linux/list.h>
|
|
#include <linux/slab.h>
|
|
#include "dsa_priv.h"
|
|
|
|
static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev)
|
|
{
|
|
struct dsa_slave_priv *p = netdev_priv(dev);
|
|
struct sk_buff *nskb;
|
|
int padlen;
|
|
u8 *trailer;
|
|
|
|
/*
|
|
* We have to make sure that the trailer ends up as the very
|
|
* last 4 bytes of the packet. This means that we have to pad
|
|
* the packet to the minimum ethernet frame size, if necessary,
|
|
* before adding the trailer.
|
|
*/
|
|
padlen = 0;
|
|
if (skb->len < 60)
|
|
padlen = 60 - skb->len;
|
|
|
|
nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC);
|
|
if (nskb == NULL) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
skb_reserve(nskb, NET_IP_ALIGN);
|
|
|
|
skb_reset_mac_header(nskb);
|
|
skb_set_network_header(nskb, skb_network_header(skb) - skb->head);
|
|
skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head);
|
|
skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
|
|
kfree_skb(skb);
|
|
|
|
if (padlen) {
|
|
u8 *pad = skb_put(nskb, padlen);
|
|
memset(pad, 0, padlen);
|
|
}
|
|
|
|
trailer = skb_put(nskb, 4);
|
|
trailer[0] = 0x80;
|
|
trailer[1] = 1 << p->port;
|
|
trailer[2] = 0x10;
|
|
trailer[3] = 0x00;
|
|
|
|
return nskb;
|
|
}
|
|
|
|
static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
|
|
struct packet_type *pt, struct net_device *orig_dev)
|
|
{
|
|
struct dsa_switch_tree *dst = dev->dsa_ptr;
|
|
struct dsa_switch *ds;
|
|
u8 *trailer;
|
|
int source_port;
|
|
|
|
if (unlikely(dst == NULL))
|
|
goto out_drop;
|
|
ds = dst->ds[0];
|
|
|
|
skb = skb_unshare(skb, GFP_ATOMIC);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
if (skb_linearize(skb))
|
|
goto out_drop;
|
|
|
|
trailer = skb_tail_pointer(skb) - 4;
|
|
if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
|
|
(trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00)
|
|
goto out_drop;
|
|
|
|
source_port = trailer[1] & 7;
|
|
if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
|
|
goto out_drop;
|
|
|
|
pskb_trim_rcsum(skb, skb->len - 4);
|
|
|
|
skb->dev = ds->ports[source_port];
|
|
skb_push(skb, ETH_HLEN);
|
|
skb->pkt_type = PACKET_HOST;
|
|
skb->protocol = eth_type_trans(skb, skb->dev);
|
|
|
|
skb->dev->stats.rx_packets++;
|
|
skb->dev->stats.rx_bytes += skb->len;
|
|
|
|
netif_receive_skb(skb);
|
|
|
|
return 0;
|
|
|
|
out_drop:
|
|
kfree_skb(skb);
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
const struct dsa_device_ops trailer_netdev_ops = {
|
|
.xmit = trailer_xmit,
|
|
.rcv = trailer_rcv,
|
|
};
|