1 /*
2 * Linux ARCnet driver - "raw mode" packet encapsulation (no soft headers)
3 *
4 * Written 1994-1999 by Avery Pennarun.
5 * Derived from skeleton.c by Donald Becker.
6 *
7 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
8 * for sponsoring the further development of this driver.
9 *
10 * **********************
11 *
12 * The original copyright of skeleton.c was as follows:
13 *
14 * skeleton.c Written 1993 by Donald Becker.
15 * Copyright 1993 United States Government as represented by the
16 * Director, National Security Agency. This software may only be used
17 * and distributed according to the terms of the GNU General Public License as
18 * modified by SRC, incorporated herein by reference.
19 *
20 * **********************
21 *
22 * For more details, see drivers/net/arcnet.c
23 *
24 * **********************
25 */
26
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/if_arp.h>
30 #include <net/arp.h>
31 #include <linux/netdevice.h>
32 #include <linux/skbuff.h>
33 #include <linux/arcdevice.h>
34
35 #define VERSION "arcnet: raw mode (`r') encapsulation support loaded.\n"
36
37
38 static void rx(struct net_device *dev, int bufnum,
39 struct archdr *pkthdr, int length);
40 static int build_header(struct sk_buff *skb, struct net_device *dev,
41 unsigned short type, uint8_t daddr);
42 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
43 int bufnum);
44
45 static struct ArcProto rawmode_proto =
46 {
47 .suffix = 'r',
48 .mtu = XMTU,
49 .rx = rx,
50 .build_header = build_header,
51 .prepare_tx = prepare_tx,
52 .continue_tx = NULL,
53 .ack_tx = NULL
54 };
55
56
57 static int __init arcnet_raw_init(void)
58 {
59 int count;
60
61 printk(VERSION);
62
63 for (count = 0; count < 256; count++)
64 if (arc_proto_map[count] == arc_proto_default)
65 arc_proto_map[count] = &rawmode_proto;
66
67 /* for raw mode, we only set the bcast proto if there's no better one */
68 if (arc_bcast_proto == arc_proto_default)
69 arc_bcast_proto = &rawmode_proto;
70
71 arc_proto_default = &rawmode_proto;
72 return 0;
73 }
74
75 static void __exit arcnet_raw_exit(void)
76 {
77 arcnet_unregister_proto(&rawmode_proto);
78 }
79
80 module_init(arcnet_raw_init);
81 module_exit(arcnet_raw_exit);
82
83 MODULE_LICENSE("GPL");
84
85
86 /* packet receiver */
87 static void rx(struct net_device *dev, int bufnum,
88 struct archdr *pkthdr, int length)
89 {
90 struct arcnet_local *lp = dev->priv;
91 struct sk_buff *skb;
92 struct archdr *pkt = pkthdr;
93 int ofs;
94
95 BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
96
97 if (length > MTU)
98 ofs = 512 - length;
99 else
100 ofs = 256 - length;
101
102 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
103 if (skb == NULL) {
104 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
105 lp->stats.rx_dropped++;
106 return;
107 }
108 skb_put(skb, length + ARC_HDR_SIZE);
109 skb->dev = dev;
110
111 pkt = (struct archdr *) skb->data;
112
113 skb_reset_mac_header(skb);
114 skb_pull(skb, ARC_HDR_SIZE);
115
116 /* up to sizeof(pkt->soft) has already been copied from the card */
117 memcpy(pkt, pkthdr, sizeof(struct archdr));
118 if (length > sizeof(pkt->soft))
119 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
120 pkt->soft.raw + sizeof(pkt->soft),
121 length - sizeof(pkt->soft));
122
123 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
124
125 skb->protocol = __constant_htons(ETH_P_ARCNET);
126 ;
127 netif_rx(skb);
128 dev->last_rx = jiffies;
129 }
130
131
132 /*
133 * Create the ARCnet hard/soft headers for raw mode.
134 * There aren't any soft headers in raw mode - not even the protocol id.
135 */
136 static int build_header(struct sk_buff *skb, struct net_device *dev,
137 unsigned short type, uint8_t daddr)
138 {
139 int hdr_size = ARC_HDR_SIZE;
140 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
141
142 /*
143 * Set the source hardware address.
144 *
145 * This is pretty pointless for most purposes, but it can help in
146 * debugging. ARCnet does not allow us to change the source address in
147 * the actual packet sent)
148 */
149 pkt->hard.source = *dev->dev_addr;
150
151 /* see linux/net/ethernet/eth.c to see where I got the following */
152
153 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
154 /*
155 * FIXME: fill in the last byte of the dest ipaddr here to better
156 * comply with RFC1051 in "noarp" mode.
157 */
158 pkt->hard.dest = 0;
159 return hdr_size;
160 }
161 /* otherwise, just fill it in and go! */
162 pkt->hard.dest = daddr;
163
164 return hdr_size; /* success */
165 }
166
167
168 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
169 int bufnum)
170 {
171 struct arcnet_local *lp = dev->priv;
172 struct arc_hardware *hard = &pkt->hard;
173 int ofs;
174
175 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
176 lp->next_tx, lp->cur_tx, bufnum);
177
178 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
179
180 if (length > XMTU) {
181 /* should never happen! other people already check for this. */
182 BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
183 length, XMTU);
184 length = XMTU;
185 }
186 if (length >= MinTU) {
187 hard->offset[0] = 0;
188 hard->offset[1] = ofs = 512 - length;
189 } else if (length > MTU) {
190 hard->offset[0] = 0;
191 hard->offset[1] = ofs = 512 - length - 3;
192 } else
193 hard->offset[0] = ofs = 256 - length;
194
195 BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
196 length,ofs);
197
198 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
199 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
200
201 lp->lastload_dest = hard->dest;
202
203 return 1; /* done */
204 }
205
|
This page was automatically generated by the
LXR engine.
|