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/*
* 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 unsigned short 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, unsigned short type,
uint8_t daddr);
static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
int bufnum);
struct ArcProto rfc1051_proto =
{
's',
XMTU - RFC1051_HDR_SIZE,
rx,
build_header,
prepare_tx
};
void __init arcnet_rfc1051_init(void)
{
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;
}
#ifdef MODULE
int __init init_module(void)
{
printk(VERSION);
arcnet_rfc1051_init();
return 0;
}
void cleanup_module(void)
{
arcnet_unregister_proto(&rfc1051_proto);
}
#endif /* MODULE */
/*
* Determine a packet's protocol ID.
*
* With ARCnet we have to convert everything to Ethernet-style stuff.
*/
static unsigned short type_trans(struct sk_buff *skb, struct net_device *dev)
{
struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
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->mac.raw = skb->data;
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 = (struct arcnet_local *) dev->priv;
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);
dev->last_rx = jiffies;
}
/*
* Create the ARCnet hard/soft headers for RFC1051.
*/
static int build_header(struct sk_buff *skb, unsigned short type,
uint8_t daddr)
{
struct net_device *dev = skb->dev;
struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
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 = (struct arcnet_local *) dev->priv;
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 */
}
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