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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/*
* net/dsa/tag_edsa.c - Ethertype DSA tagging
* 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/netdevice.h>
#include "dsa_priv.h"
#define DSA_HLEN 4
#define EDSA_HLEN 8
int edsa_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct dsa_slave_priv *p = netdev_priv(dev);
u8 *edsa_header;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
/*
* Convert the outermost 802.1q tag to a DSA tag and prepend
* a DSA ethertype field is the packet is tagged, or insert
* a DSA ethertype plus DSA tag between the addresses and the
* current ethertype field if the packet is untagged.
*/
if (skb->protocol == htons(ETH_P_8021Q)) {
if (skb_cow_head(skb, DSA_HLEN) < 0)
goto out_free;
skb_push(skb, DSA_HLEN);
memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);
/*
* Construct tagged FROM_CPU DSA tag from 802.1q tag.
*/
edsa_header = skb->data + 2 * ETH_ALEN;
edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
edsa_header[1] = ETH_P_EDSA & 0xff;
edsa_header[2] = 0x00;
edsa_header[3] = 0x00;
edsa_header[4] = 0x60 | p->parent->index;
edsa_header[5] = p->port << 3;
/*
* Move CFI field from byte 6 to byte 5.
*/
if (edsa_header[6] & 0x10) {
edsa_header[5] |= 0x01;
edsa_header[6] &= ~0x10;
}
} else {
if (skb_cow_head(skb, EDSA_HLEN) < 0)
goto out_free;
skb_push(skb, EDSA_HLEN);
memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN);
/*
* Construct untagged FROM_CPU DSA tag.
*/
edsa_header = skb->data + 2 * ETH_ALEN;
edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
edsa_header[1] = ETH_P_EDSA & 0xff;
edsa_header[2] = 0x00;
edsa_header[3] = 0x00;
edsa_header[4] = 0x40 | p->parent->index;
edsa_header[5] = p->port << 3;
edsa_header[6] = 0x00;
edsa_header[7] = 0x00;
}
skb->protocol = htons(ETH_P_EDSA);
skb->dev = p->parent->dst->master_netdev;
dev_queue_xmit(skb);
return NETDEV_TX_OK;
out_free:
kfree_skb(skb);
return NETDEV_TX_OK;
}
static int edsa_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 *edsa_header;
int source_device;
int source_port;
if (unlikely(dst == NULL))
goto out_drop;
skb = skb_unshare(skb, GFP_ATOMIC);
if (skb == NULL)
goto out;
if (unlikely(!pskb_may_pull(skb, EDSA_HLEN)))
goto out_drop;
/*
* Skip the two null bytes after the ethertype.
*/
edsa_header = skb->data + 2;
/*
* Check that frame type is either TO_CPU or FORWARD.
*/
if ((edsa_header[0] & 0xc0) != 0x00 && (edsa_header[0] & 0xc0) != 0xc0)
goto out_drop;
/*
* Determine source device and port.
*/
source_device = edsa_header[0] & 0x1f;
source_port = (edsa_header[1] >> 3) & 0x1f;
/*
* Check that the source device exists and that the source
* port is a registered DSA port.
*/
if (source_device >= dst->pd->nr_chips)
goto out_drop;
ds = dst->ds[source_device];
if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
goto out_drop;
/*
* If the 'tagged' bit is set, convert the DSA tag to a 802.1q
* tag and delete the ethertype part. If the 'tagged' bit is
* clear, delete the ethertype and the DSA tag parts.
*/
if (edsa_header[0] & 0x20) {
u8 new_header[4];
/*
* Insert 802.1q ethertype and copy the VLAN-related
* fields, but clear the bit that will hold CFI (since
* DSA uses that bit location for another purpose).
*/
new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
new_header[1] = ETH_P_8021Q & 0xff;
new_header[2] = edsa_header[2] & ~0x10;
new_header[3] = edsa_header[3];
/*
* Move CFI bit from its place in the DSA header to
* its 802.1q-designated place.
*/
if (edsa_header[1] & 0x01)
new_header[2] |= 0x10;
skb_pull_rcsum(skb, DSA_HLEN);
/*
* Update packet checksum if skb is CHECKSUM_COMPLETE.
*/
if (skb->ip_summed == CHECKSUM_COMPLETE) {
__wsum c = skb->csum;
c = csum_add(c, csum_partial(new_header + 2, 2, 0));
c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0));
skb->csum = c;
}
memcpy(edsa_header, new_header, DSA_HLEN);
memmove(skb->data - ETH_HLEN,
skb->data - ETH_HLEN - DSA_HLEN,
2 * ETH_ALEN);
} else {
/*
* Remove DSA tag and update checksum.
*/
skb_pull_rcsum(skb, EDSA_HLEN);
memmove(skb->data - ETH_HLEN,
skb->data - ETH_HLEN - EDSA_HLEN,
2 * ETH_ALEN);
}
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;
}
static struct packet_type edsa_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_EDSA),
.func = edsa_rcv,
};
static int __init edsa_init_module(void)
{
dev_add_pack(&edsa_packet_type);
return 0;
}
module_init(edsa_init_module);
static void __exit edsa_cleanup_module(void)
{
dev_remove_pack(&edsa_packet_type);
}
module_exit(edsa_cleanup_module);
|
