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/*
* Linux ARCnet driver - "raw mode" packet encapsulation (no soft headers)
*
* 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
*
* **********************
*/
#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/gfp.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>
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 rawmode_proto = {
.suffix = 'r',
.mtu = XMTU,
.rx = rx,
.build_header = build_header,
.prepare_tx = prepare_tx,
.continue_tx = NULL,
.ack_tx = NULL
};
static int __init arcnet_raw_init(void)
{
int count;
pr_info("%s\n", "raw mode (`r') encapsulation support loaded");
for (count = 0; count < 256; count++)
if (arc_proto_map[count] == arc_proto_default)
arc_proto_map[count] = &rawmode_proto;
/* for raw mode, we only set the bcast proto if there's no better one */
if (arc_bcast_proto == arc_proto_default)
arc_bcast_proto = &rawmode_proto;
arc_proto_default = &rawmode_proto;
return 0;
}
static void __exit arcnet_raw_exit(void)
{
arcnet_unregister_proto(&rawmode_proto);
}
module_init(arcnet_raw_init);
module_exit(arcnet_raw_exit);
MODULE_LICENSE("GPL");
/* 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;
arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
if (length > MTU)
ofs = 512 - length;
else
ofs = 256 - length;
skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
if (skb == NULL) {
arc_printk(D_NORMAL, dev, "Memory squeeze, dropping packet\n");
dev->stats.rx_dropped++;
return;
}
skb_put(skb, length + ARC_HDR_SIZE);
skb->dev = dev;
pkt = (struct archdr *)skb->data;
skb_reset_mac_header(skb);
skb_pull(skb, ARC_HDR_SIZE);
/* 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));
if (BUGLVL(D_SKB))
arcnet_dump_skb(dev, skb, "rx");
skb->protocol = cpu_to_be16(ETH_P_ARCNET);
netif_rx(skb);
}
/* Create the ARCnet hard/soft headers for raw mode.
* There aren't any soft headers in raw mode - not even the protocol id.
*/
static int build_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, uint8_t daddr)
{
int hdr_size = ARC_HDR_SIZE;
struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
/* 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;
arc_printk(D_DURING, dev, "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. */
arc_printk(D_NORMAL, dev, "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;
}
arc_printk(D_DURING, dev, "prepare_tx: length=%d ofs=%d\n",
length, ofs);
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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