1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
* net/dsa/tag_trailer.c - Trailer tag format handling
* Copyright (c) 2008 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/netdevice.h>
#include "dsa_priv.h"
int 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;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
/*
* 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 NETDEV_TX_OK;
}
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;
nskb->protocol = htons(ETH_P_TRAILER);
nskb->dev = p->parent->master_netdev;
dev_queue_xmit(nskb);
return NETDEV_TX_OK;
}
static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct dsa_switch *ds = dev->dsa_ptr;
u8 *trailer;
int source_port;
if (unlikely(ds == NULL))
goto out_drop;
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->protocol = eth_type_trans(skb, skb->dev);
skb->dev->last_rx = jiffies;
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;
}
static struct packet_type trailer_packet_type = {
.type = __constant_htons(ETH_P_TRAILER),
.func = trailer_rcv,
};
static int __init trailer_init_module(void)
{
dev_add_pack(&trailer_packet_type);
return 0;
}
module_init(trailer_init_module);
static void __exit trailer_cleanup_module(void)
{
dev_remove_pack(&trailer_packet_type);
}
module_exit(trailer_cleanup_module);
|
