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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
Joe Perchescb334642015-05-05 10:05:47 -07003 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#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: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"
36
Al Viro701181a2007-08-22 22:59:11 -040037static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038static void rx(struct net_device *dev, int bufnum,
39 struct archdr *pkthdr, int length);
40static int build_header(struct sk_buff *skb, struct net_device *dev,
41 unsigned short type, uint8_t daddr);
42static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
43 int bufnum);
44
Joe Perches7f5e7602015-05-05 10:05:49 -070045static struct ArcProto rfc1051_proto = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 .suffix = 's',
47 .mtu = XMTU - RFC1051_HDR_SIZE,
48 .is_ip = 1,
49 .rx = rx,
50 .build_header = build_header,
51 .prepare_tx = prepare_tx,
52 .continue_tx = NULL,
53 .ack_tx = NULL
54};
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056static int __init arcnet_rfc1051_init(void)
57{
58 printk(VERSION);
59
60 arc_proto_map[ARC_P_IP_RFC1051]
61 = arc_proto_map[ARC_P_ARP_RFC1051]
62 = &rfc1051_proto;
63
64 /* if someone else already owns the broadcast, we won't take it */
65 if (arc_bcast_proto == arc_proto_default)
66 arc_bcast_proto = &rfc1051_proto;
67
68 return 0;
69}
70
71static void __exit arcnet_rfc1051_exit(void)
72{
73 arcnet_unregister_proto(&rfc1051_proto);
74}
75
76module_init(arcnet_rfc1051_init);
77module_exit(arcnet_rfc1051_exit);
78
79MODULE_LICENSE("GPL");
80
Joe Perchesf2f0a162015-05-05 10:05:52 -070081/* Determine a packet's protocol ID.
Joe Perchescb334642015-05-05 10:05:47 -070082 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 * With ARCnet we have to convert everything to Ethernet-style stuff.
84 */
Al Viro701181a2007-08-22 22:59:11 -040085static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086{
Joe Perchescb334642015-05-05 10:05:47 -070087 struct archdr *pkt = (struct archdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
89 int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
90
91 /* Pull off the arcnet header. */
Arnaldo Carvalho de Melo459a98e2007-03-19 15:30:44 -070092 skb_reset_mac_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 skb_pull(skb, hdr_size);
94
Joe Perches7f5e7602015-05-05 10:05:49 -070095 if (pkt->hard.dest == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 skb->pkt_type = PACKET_BROADCAST;
Joe Perches7f5e7602015-05-05 10:05:49 -070097 } else if (dev->flags & IFF_PROMISC) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 /* if we're not sending to ourselves :) */
99 if (pkt->hard.dest != dev->dev_addr[0])
100 skb->pkt_type = PACKET_OTHERHOST;
101 }
102 /* now return the protocol number */
103 switch (soft->proto) {
104 case ARC_P_IP_RFC1051:
105 return htons(ETH_P_IP);
106 case ARC_P_ARP_RFC1051:
107 return htons(ETH_P_ARP);
108
109 default:
Stephen Hemminger5803c512009-01-09 13:01:08 +0000110 dev->stats.rx_errors++;
111 dev->stats.rx_crc_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return 0;
113 }
114
115 return htons(ETH_P_IP);
116}
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118/* packet receiver */
119static void rx(struct net_device *dev, int bufnum,
120 struct archdr *pkthdr, int length)
121{
Wang Chen454d7c92008-11-12 23:37:49 -0800122 struct arcnet_local *lp = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 struct sk_buff *skb;
124 struct archdr *pkt = pkthdr;
125 int ofs;
126
Joe Perchesa34c0932015-05-05 10:05:55 -0700127 arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129 if (length >= MinTU)
130 ofs = 512 - length;
131 else
132 ofs = 256 - length;
133
134 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
135 if (skb == NULL) {
Joe Perchesa34c0932015-05-05 10:05:55 -0700136 arc_printk(D_NORMAL, dev, "Memory squeeze, dropping packet\n");
Stephen Hemminger5803c512009-01-09 13:01:08 +0000137 dev->stats.rx_dropped++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 return;
139 }
140 skb_put(skb, length + ARC_HDR_SIZE);
141 skb->dev = dev;
142
Joe Perchescb334642015-05-05 10:05:47 -0700143 pkt = (struct archdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 /* up to sizeof(pkt->soft) has already been copied from the card */
146 memcpy(pkt, pkthdr, sizeof(struct archdr));
147 if (length > sizeof(pkt->soft))
148 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
149 pkt->soft.raw + sizeof(pkt->soft),
150 length - sizeof(pkt->soft));
151
Joe Perches72aeea42015-05-05 10:05:54 -0700152 if (BUGLVL(D_SKB))
153 arcnet_dump_skb(dev, skb, "rx");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155 skb->protocol = type_trans(skb, dev);
156 netif_rx(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158
Joe Perchesf2f0a162015-05-05 10:05:52 -0700159/* Create the ARCnet hard/soft headers for RFC1051 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160static int build_header(struct sk_buff *skb, struct net_device *dev,
161 unsigned short type, uint8_t daddr)
162{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
Joe Perchescb334642015-05-05 10:05:47 -0700164 struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
166
167 /* set the protocol ID according to RFC1051 */
168 switch (type) {
169 case ETH_P_IP:
170 soft->proto = ARC_P_IP_RFC1051;
171 break;
172 case ETH_P_ARP:
173 soft->proto = ARC_P_ARP_RFC1051;
174 break;
175 default:
Joe Perchesa34c0932015-05-05 10:05:55 -0700176 arc_printk(D_NORMAL, dev, "RFC1051: I don't understand protocol %d (%Xh)\n",
177 type, type);
Stephen Hemminger5803c512009-01-09 13:01:08 +0000178 dev->stats.tx_errors++;
179 dev->stats.tx_aborted_errors++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 return 0;
181 }
182
Joe Perchesf2f0a162015-05-05 10:05:52 -0700183 /* Set the source hardware address.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 *
185 * This is pretty pointless for most purposes, but it can help in
Joe Perchesf2f0a162015-05-05 10:05:52 -0700186 * debugging. ARCnet does not allow us to change the source address
187 * in the actual packet sent.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 */
189 pkt->hard.source = *dev->dev_addr;
190
191 /* see linux/net/ethernet/eth.c to see where I got the following */
192
193 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
Joe Perchesf2f0a162015-05-05 10:05:52 -0700194 /* FIXME: fill in the last byte of the dest ipaddr here to
195 * better comply with RFC1051 in "noarp" mode.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 */
197 pkt->hard.dest = 0;
198 return hdr_size;
199 }
200 /* otherwise, just fill it in and go! */
201 pkt->hard.dest = daddr;
202
203 return hdr_size; /* success */
204}
205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
207 int bufnum)
208{
Wang Chen454d7c92008-11-12 23:37:49 -0800209 struct arcnet_local *lp = netdev_priv(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 struct arc_hardware *hard = &pkt->hard;
211 int ofs;
212
Joe Perchesa34c0932015-05-05 10:05:55 -0700213 arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
214 lp->next_tx, lp->cur_tx, bufnum);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
217
218 if (length > XMTU) {
219 /* should never happen! other people already check for this. */
Joe Perchesa34c0932015-05-05 10:05:55 -0700220 arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n",
221 length, XMTU);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 length = XMTU;
223 }
224 if (length > MinTU) {
225 hard->offset[0] = 0;
226 hard->offset[1] = ofs = 512 - length;
227 } else if (length > MTU) {
228 hard->offset[0] = 0;
229 hard->offset[1] = ofs = 512 - length - 3;
Joe Perches7f5e7602015-05-05 10:05:49 -0700230 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 hard->offset[0] = ofs = 256 - length;
Joe Perches7f5e7602015-05-05 10:05:49 -0700232 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
234 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
235 lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
236
237 lp->lastload_dest = hard->dest;
238
239 return 1; /* done */
240}