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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 the16 * Director, National Security Agency. This software may only be used17 * and distributed according to the terms of the GNU General Public License as18 * modified by SRC, incorporated herein by reference.19 *20 * **********************21 *22 * For more details, see drivers/net/arcnet.c23 *24 * **********************25 */26 27#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt28 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 else52 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 in93 * debugging. ARCnet does not allow us to change the source address94 * 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 here102 * 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 = NULL161};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");191