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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#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
28
29#include <linux/module.h>
30#include <linux/gfp.h>
31#include <linux/init.h>
32#include <linux/if_arp.h>
33#include <net/arp.h>
34#include <linux/netdevice.h>
35#include <linux/skbuff.h>
36#include "arcdevice.h"
37
38/* packet receiver */
39static void rx(struct net_device *dev, int bufnum,
40 struct archdr *pkthdr, int length)
41{
42 struct arcnet_local *lp = netdev_priv(dev);
43 struct sk_buff *skb;
44 struct archdr *pkt = pkthdr;
45 int ofs;
46
47 arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
48
49 if (length > MTU)
50 ofs = 512 - length;
51 else
52 ofs = 256 - length;
53
54 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
55 if (!skb) {
56 dev->stats.rx_dropped++;
57 return;
58 }
59 skb_put(skb, length + ARC_HDR_SIZE);
60 skb->dev = dev;
61
62 pkt = (struct archdr *)skb->data;
63
64 skb_reset_mac_header(skb);
65 skb_pull(skb, ARC_HDR_SIZE);
66
67 /* up to sizeof(pkt->soft) has already been copied from the card */
68 memcpy(pkt, pkthdr, sizeof(struct archdr));
69 if (length > sizeof(pkt->soft))
70 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
71 pkt->soft.raw + sizeof(pkt->soft),
72 length - sizeof(pkt->soft));
73
74 if (BUGLVL(D_SKB))
75 arcnet_dump_skb(dev, skb, "rx");
76
77 skb->protocol = cpu_to_be16(ETH_P_ARCNET);
78 netif_rx(skb);
79}
80
81/* Create the ARCnet hard/soft headers for raw mode.
82 * There aren't any soft headers in raw mode - not even the protocol id.
83 */
84static int build_header(struct sk_buff *skb, struct net_device *dev,
85 unsigned short type, uint8_t daddr)
86{
87 int hdr_size = ARC_HDR_SIZE;
88 struct archdr *pkt = skb_push(skb, hdr_size);
89
90 /* Set the source hardware address.
91 *
92 * This is pretty pointless for most purposes, but it can help in
93 * debugging. ARCnet does not allow us to change the source address
94 * in the actual packet sent.
95 */
96 pkt->hard.source = *dev->dev_addr;
97
98 /* see linux/net/ethernet/eth.c to see where I got the following */
99
100 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
101 /* FIXME: fill in the last byte of the dest ipaddr here
102 * to better comply with RFC1051 in "noarp" mode.
103 */
104 pkt->hard.dest = 0;
105 return hdr_size;
106 }
107 /* otherwise, just fill it in and go! */
108 pkt->hard.dest = daddr;
109
110 return hdr_size; /* success */
111}
112
113static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
114 int bufnum)
115{
116 struct arcnet_local *lp = netdev_priv(dev);
117 struct arc_hardware *hard = &pkt->hard;
118 int ofs;
119
120 arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
121 lp->next_tx, lp->cur_tx, bufnum);
122
123 /* hard header is not included in packet length */
124 length -= ARC_HDR_SIZE;
125
126 if (length > XMTU) {
127 /* should never happen! other people already check for this. */
128 arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n",
129 length, XMTU);
130 length = XMTU;
131 }
132 if (length >= MinTU) {
133 hard->offset[0] = 0;
134 hard->offset[1] = ofs = 512 - length;
135 } else if (length > MTU) {
136 hard->offset[0] = 0;
137 hard->offset[1] = ofs = 512 - length - 3;
138 } else {
139 hard->offset[0] = ofs = 256 - length;
140 }
141
142 arc_printk(D_DURING, dev, "prepare_tx: length=%d ofs=%d\n",
143 length, ofs);
144
145 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
146 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
147
148 lp->lastload_dest = hard->dest;
149
150 return 1; /* done */
151}
152
153static struct ArcProto rawmode_proto = {
154 .suffix = 'r',
155 .mtu = XMTU,
156 .rx = rx,
157 .build_header = build_header,
158 .prepare_tx = prepare_tx,
159 .continue_tx = NULL,
160 .ack_tx = NULL
161};
162
163static int __init arcnet_raw_init(void)
164{
165 int count;
166
167 pr_info("raw mode (`r') encapsulation support loaded\n");
168
169 for (count = 0; count < 256; count++)
170 if (arc_proto_map[count] == arc_proto_default)
171 arc_proto_map[count] = &rawmode_proto;
172
173 /* for raw mode, we only set the bcast proto if there's no better one */
174 if (arc_bcast_proto == arc_proto_default)
175 arc_bcast_proto = &rawmode_proto;
176
177 arc_proto_default = &rawmode_proto;
178 return 0;
179}
180
181static void __exit arcnet_raw_exit(void)
182{
183 arcnet_unregister_proto(&rawmode_proto);
184}
185
186module_init(arcnet_raw_init);
187module_exit(arcnet_raw_exit);
188
189MODULE_DESCRIPTION("ARCnet raw mode packet interface module");
190MODULE_LICENSE("GPL");
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/gfp.h>
29#include <linux/init.h>
30#include <linux/if_arp.h>
31#include <net/arp.h>
32#include <linux/netdevice.h>
33#include <linux/skbuff.h>
34#include <linux/arcdevice.h>
35
36#define VERSION "arcnet: raw mode (`r') encapsulation support loaded.\n"
37
38
39static void rx(struct net_device *dev, int bufnum,
40 struct archdr *pkthdr, int length);
41static int build_header(struct sk_buff *skb, struct net_device *dev,
42 unsigned short type, uint8_t daddr);
43static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
44 int bufnum);
45
46static struct ArcProto rawmode_proto =
47{
48 .suffix = 'r',
49 .mtu = XMTU,
50 .rx = rx,
51 .build_header = build_header,
52 .prepare_tx = prepare_tx,
53 .continue_tx = NULL,
54 .ack_tx = NULL
55};
56
57
58static int __init arcnet_raw_init(void)
59{
60 int count;
61
62 printk(VERSION);
63
64 for (count = 0; count < 256; count++)
65 if (arc_proto_map[count] == arc_proto_default)
66 arc_proto_map[count] = &rawmode_proto;
67
68 /* for raw mode, we only set the bcast proto if there's no better one */
69 if (arc_bcast_proto == arc_proto_default)
70 arc_bcast_proto = &rawmode_proto;
71
72 arc_proto_default = &rawmode_proto;
73 return 0;
74}
75
76static void __exit arcnet_raw_exit(void)
77{
78 arcnet_unregister_proto(&rawmode_proto);
79}
80
81module_init(arcnet_raw_init);
82module_exit(arcnet_raw_exit);
83
84MODULE_LICENSE("GPL");
85
86
87/* packet receiver */
88static void rx(struct net_device *dev, int bufnum,
89 struct archdr *pkthdr, int length)
90{
91 struct arcnet_local *lp = netdev_priv(dev);
92 struct sk_buff *skb;
93 struct archdr *pkt = pkthdr;
94 int ofs;
95
96 BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
97
98 if (length > MTU)
99 ofs = 512 - length;
100 else
101 ofs = 256 - length;
102
103 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
104 if (skb == NULL) {
105 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
106 dev->stats.rx_dropped++;
107 return;
108 }
109 skb_put(skb, length + ARC_HDR_SIZE);
110 skb->dev = dev;
111
112 pkt = (struct archdr *) skb->data;
113
114 skb_reset_mac_header(skb);
115 skb_pull(skb, ARC_HDR_SIZE);
116
117 /* up to sizeof(pkt->soft) has already been copied from the card */
118 memcpy(pkt, pkthdr, sizeof(struct archdr));
119 if (length > sizeof(pkt->soft))
120 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
121 pkt->soft.raw + sizeof(pkt->soft),
122 length - sizeof(pkt->soft));
123
124 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
125
126 skb->protocol = cpu_to_be16(ETH_P_ARCNET);
127 netif_rx(skb);
128}
129
130
131/*
132 * Create the ARCnet hard/soft headers for raw mode.
133 * There aren't any soft headers in raw mode - not even the protocol id.
134 */
135static int build_header(struct sk_buff *skb, struct net_device *dev,
136 unsigned short type, uint8_t daddr)
137{
138 int hdr_size = ARC_HDR_SIZE;
139 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
140
141 /*
142 * Set the source hardware address.
143 *
144 * This is pretty pointless for most purposes, but it can help in
145 * debugging. ARCnet does not allow us to change the source address in
146 * the actual packet sent)
147 */
148 pkt->hard.source = *dev->dev_addr;
149
150 /* see linux/net/ethernet/eth.c to see where I got the following */
151
152 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
153 /*
154 * FIXME: fill in the last byte of the dest ipaddr here to better
155 * comply with RFC1051 in "noarp" mode.
156 */
157 pkt->hard.dest = 0;
158 return hdr_size;
159 }
160 /* otherwise, just fill it in and go! */
161 pkt->hard.dest = daddr;
162
163 return hdr_size; /* success */
164}
165
166
167static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
168 int bufnum)
169{
170 struct arcnet_local *lp = netdev_priv(dev);
171 struct arc_hardware *hard = &pkt->hard;
172 int ofs;
173
174 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
175 lp->next_tx, lp->cur_tx, bufnum);
176
177 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
178
179 if (length > XMTU) {
180 /* should never happen! other people already check for this. */
181 BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
182 length, XMTU);
183 length = XMTU;
184 }
185 if (length >= MinTU) {
186 hard->offset[0] = 0;
187 hard->offset[1] = ofs = 512 - length;
188 } else if (length > MTU) {
189 hard->offset[0] = 0;
190 hard->offset[1] = ofs = 512 - length - 3;
191 } else
192 hard->offset[0] = ofs = 256 - length;
193
194 BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
195 length,ofs);
196
197 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
198 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
199
200 lp->lastload_dest = hard->dest;
201
202 return 1; /* done */
203}