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
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
/*
* Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
*
* Written 1994-1999 by Avery Pennarun.
* Derived from skeleton.c by Donald Becker.
*
* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
* for sponsoring the further development of this driver.
*
* **********************
*
* The original copyright of skeleton.c was as follows:
*
* skeleton.c Written 1993 by Donald Becker.
* Copyright 1993 United States Government as represented by the
* Director, National Security Agency. This software may only be used
* and distributed according to the terms of the GNU General Public License as
* modified by SRC, incorporated herein by reference.
*
* **********************
*
* For more details, see drivers/net/arcnet.c
*
* **********************
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/arcdevice.h>
#define VERSION "arcnet: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"
static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
static void rx(struct net_device *dev, int bufnum,
struct archdr *pkthdr, int length);
static int build_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, uint8_t daddr);
static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
int bufnum);
static struct ArcProto rfc1051_proto =
{
.suffix = 's',
.mtu = XMTU - RFC1051_HDR_SIZE,
.is_ip = 1,
.rx = rx,
.build_header = build_header,
.prepare_tx = prepare_tx,
.continue_tx = NULL,
.ack_tx = NULL
};
static int __init arcnet_rfc1051_init(void)
{
printk(VERSION);
arc_proto_map[ARC_P_IP_RFC1051]
= arc_proto_map[ARC_P_ARP_RFC1051]
= &rfc1051_proto;
/* if someone else already owns the broadcast, we won't take it */
if (arc_bcast_proto == arc_proto_default)
arc_bcast_proto = &rfc1051_proto;
return 0;
}
static void __exit arcnet_rfc1051_exit(void)
{
arcnet_unregister_proto(&rfc1051_proto);
}
module_init(arcnet_rfc1051_init);
module_exit(arcnet_rfc1051_exit);
MODULE_LICENSE("GPL");
/*
* Determine a packet's protocol ID.
*
* With ARCnet we have to convert everything to Ethernet-style stuff.
*/
static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
{
struct arcnet_local *lp = netdev_priv(dev);
struct archdr *pkt = (struct archdr *) skb->data;
struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
/* Pull off the arcnet header. */
skb_reset_mac_header(skb);
skb_pull(skb, hdr_size);
if (pkt->hard.dest == 0)
skb->pkt_type = PACKET_BROADCAST;
else if (dev->flags & IFF_PROMISC) {
/* if we're not sending to ourselves :) */
if (pkt->hard.dest != dev->dev_addr[0])
skb->pkt_type = PACKET_OTHERHOST;
}
/* now return the protocol number */
switch (soft->proto) {
case ARC_P_IP_RFC1051:
return htons(ETH_P_IP);
case ARC_P_ARP_RFC1051:
return htons(ETH_P_ARP);
default:
lp->stats.rx_errors++;
lp->stats.rx_crc_errors++;
return 0;
}
return htons(ETH_P_IP);
}
/* packet receiver */
static void rx(struct net_device *dev, int bufnum,
struct archdr *pkthdr, int length)
{
struct arcnet_local *lp = netdev_priv(dev);
struct sk_buff *skb;
struct archdr *pkt = pkthdr;
int ofs;
BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
if (length >= MinTU)
ofs = 512 - length;
else
ofs = 256 - length;
skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
if (skb == NULL) {
BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
lp->stats.rx_dropped++;
return;
}
skb_put(skb, length + ARC_HDR_SIZE);
skb->dev = dev;
pkt = (struct archdr *) skb->data;
/* up to sizeof(pkt->soft) has already been copied from the card */
memcpy(pkt, pkthdr, sizeof(struct archdr));
if (length > sizeof(pkt->soft))
lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
pkt->soft.raw + sizeof(pkt->soft),
length - sizeof(pkt->soft));
BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
skb->protocol = type_trans(skb, dev);
netif_rx(skb);
}
/*
* Create the ARCnet hard/soft headers for RFC1051.
*/
static int build_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, uint8_t daddr)
{
struct arcnet_local *lp = netdev_priv(dev);
int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
/* set the protocol ID according to RFC1051 */
switch (type) {
case ETH_P_IP:
soft->proto = ARC_P_IP_RFC1051;
break;
case ETH_P_ARP:
soft->proto = ARC_P_ARP_RFC1051;
break;
default:
BUGMSG(D_NORMAL, "RFC1051: I don't understand protocol %d (%Xh)\n",
type, type);
lp->stats.tx_errors++;
lp->stats.tx_aborted_errors++;
return 0;
}
/*
* Set the source hardware address.
*
* This is pretty pointless for most purposes, but it can help in
* debugging. ARCnet does not allow us to change the source address in
* the actual packet sent)
*/
pkt->hard.source = *dev->dev_addr;
/* see linux/net/ethernet/eth.c to see where I got the following */
if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
/*
* FIXME: fill in the last byte of the dest ipaddr here to better
* comply with RFC1051 in "noarp" mode.
*/
pkt->hard.dest = 0;
return hdr_size;
}
/* otherwise, just fill it in and go! */
pkt->hard.dest = daddr;
return hdr_size; /* success */
}
static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
int bufnum)
{
struct arcnet_local *lp = netdev_priv(dev);
struct arc_hardware *hard = &pkt->hard;
int ofs;
BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
lp->next_tx, lp->cur_tx, bufnum);
length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
if (length > XMTU) {
/* should never happen! other people already check for this. */
BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
length, XMTU);
length = XMTU;
}
if (length > MinTU) {
hard->offset[0] = 0;
hard->offset[1] = ofs = 512 - length;
} else if (length > MTU) {
hard->offset[0] = 0;
hard->offset[1] = ofs = 512 - length - 3;
} else
hard->offset[0] = ofs = 256 - length;
lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
lp->lastload_dest = hard->dest;
return 1; /* done */
}
|
