/*
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* Linux ARCnet driver - RFC1201 (standard) packet encapsulation
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*
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* Written 1994-1999 by Avery Pennarun.
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* Derived from skeleton.c by Donald Becker.
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*
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* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
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* for sponsoring the further development of this driver.
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*
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* **********************
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*
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* The original copyright of skeleton.c was as follows:
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*
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* skeleton.c Written 1993 by Donald Becker.
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* Copyright 1993 United States Government as represented by the
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* Director, National Security Agency. This software may only be used
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* and distributed according to the terms of the GNU General Public License as
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* modified by SRC, incorporated herein by reference.
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*
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* **********************
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*
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* For more details, see drivers/net/arcnet.c
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*
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* **********************
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*/
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#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
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#include <linux/gfp.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/if_arp.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include "arcdevice.h"
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MODULE_LICENSE("GPL");
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static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
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static void rx(struct net_device *dev, int bufnum,
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struct archdr *pkthdr, int length);
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static int build_header(struct sk_buff *skb, struct net_device *dev,
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unsigned short type, uint8_t daddr);
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static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
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int bufnum);
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static int continue_tx(struct net_device *dev, int bufnum);
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static struct ArcProto rfc1201_proto = {
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.suffix = 'a',
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.mtu = 1500, /* could be more, but some receivers can't handle it... */
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.is_ip = 1, /* This is for sending IP and ARP packages */
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.rx = rx,
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.build_header = build_header,
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.prepare_tx = prepare_tx,
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.continue_tx = continue_tx,
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.ack_tx = NULL
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};
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static int __init arcnet_rfc1201_init(void)
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{
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pr_info("%s\n", "RFC1201 \"standard\" (`a') encapsulation support loaded");
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arc_proto_map[ARC_P_IP]
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= arc_proto_map[ARC_P_IPV6]
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= arc_proto_map[ARC_P_ARP]
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= arc_proto_map[ARC_P_RARP]
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= arc_proto_map[ARC_P_IPX]
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= arc_proto_map[ARC_P_NOVELL_EC]
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= &rfc1201_proto;
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/* if someone else already owns the broadcast, we won't take it */
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if (arc_bcast_proto == arc_proto_default)
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arc_bcast_proto = &rfc1201_proto;
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return 0;
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}
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static void __exit arcnet_rfc1201_exit(void)
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{
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arcnet_unregister_proto(&rfc1201_proto);
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}
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module_init(arcnet_rfc1201_init);
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module_exit(arcnet_rfc1201_exit);
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/* Determine a packet's protocol ID.
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*
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* With ARCnet we have to convert everything to Ethernet-style stuff.
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*/
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static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
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{
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struct archdr *pkt = (struct archdr *)skb->data;
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struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
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int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
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/* Pull off the arcnet header. */
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skb_reset_mac_header(skb);
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skb_pull(skb, hdr_size);
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if (pkt->hard.dest == 0) {
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skb->pkt_type = PACKET_BROADCAST;
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} else if (dev->flags & IFF_PROMISC) {
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/* if we're not sending to ourselves :) */
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if (pkt->hard.dest != dev->dev_addr[0])
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skb->pkt_type = PACKET_OTHERHOST;
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}
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/* now return the protocol number */
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switch (soft->proto) {
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case ARC_P_IP:
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return htons(ETH_P_IP);
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case ARC_P_IPV6:
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return htons(ETH_P_IPV6);
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case ARC_P_ARP:
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return htons(ETH_P_ARP);
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case ARC_P_RARP:
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return htons(ETH_P_RARP);
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case ARC_P_IPX:
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case ARC_P_NOVELL_EC:
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return htons(ETH_P_802_3);
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default:
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dev->stats.rx_errors++;
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dev->stats.rx_crc_errors++;
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return 0;
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}
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return htons(ETH_P_IP);
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}
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/* packet receiver */
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static void rx(struct net_device *dev, int bufnum,
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struct archdr *pkthdr, int length)
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{
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struct arcnet_local *lp = netdev_priv(dev);
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struct sk_buff *skb;
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struct archdr *pkt = pkthdr;
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struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
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int saddr = pkt->hard.source, ofs;
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struct Incoming *in = &lp->rfc1201.incoming[saddr];
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arc_printk(D_DURING, dev, "it's an RFC1201 packet (length=%d)\n",
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length);
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if (length >= MinTU)
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ofs = 512 - length;
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else
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ofs = 256 - length;
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if (soft->split_flag == 0xFF) { /* Exception Packet */
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if (length >= 4 + RFC1201_HDR_SIZE) {
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arc_printk(D_DURING, dev, "compensating for exception packet\n");
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} else {
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arc_printk(D_EXTRA, dev, "short RFC1201 exception packet from %02Xh",
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saddr);
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return;
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}
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/* skip over 4-byte junkola */
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length -= 4;
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ofs += 4;
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lp->hw.copy_from_card(dev, bufnum, 512 - length,
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soft, sizeof(pkt->soft));
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}
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if (!soft->split_flag) { /* not split */
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arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n",
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soft->split_flag);
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if (in->skb) { /* already assembling one! */
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arc_printk(D_EXTRA, dev, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
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in->sequence, soft->split_flag,
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soft->sequence);
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lp->rfc1201.aborted_seq = soft->sequence;
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dev_kfree_skb_irq(in->skb);
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dev->stats.rx_errors++;
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dev->stats.rx_missed_errors++;
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in->skb = NULL;
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}
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in->sequence = soft->sequence;
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skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
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if (!skb) {
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dev->stats.rx_dropped++;
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return;
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}
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skb_put(skb, length + ARC_HDR_SIZE);
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skb->dev = dev;
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pkt = (struct archdr *)skb->data;
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soft = &pkt->soft.rfc1201;
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/* up to sizeof(pkt->soft) has already
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* been copied from the card
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*/
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memcpy(pkt, pkthdr, sizeof(struct archdr));
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if (length > sizeof(pkt->soft))
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lp->hw.copy_from_card(dev, bufnum,
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ofs + sizeof(pkt->soft),
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pkt->soft.raw + sizeof(pkt->soft),
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length - sizeof(pkt->soft));
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/* ARP packets have problems when sent from some DOS systems:
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* the source address is always 0!
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* So we take the hardware source addr (which is impossible
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* to fumble) and insert it ourselves.
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*/
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if (soft->proto == ARC_P_ARP) {
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struct arphdr *arp = (struct arphdr *)soft->payload;
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/* make sure addresses are the right length */
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if (arp->ar_hln == 1 && arp->ar_pln == 4) {
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uint8_t *cptr = (uint8_t *)arp + sizeof(struct arphdr);
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if (!*cptr) { /* is saddr = 00? */
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arc_printk(D_EXTRA, dev,
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"ARP source address was 00h, set to %02Xh\n",
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saddr);
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dev->stats.rx_crc_errors++;
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*cptr = saddr;
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} else {
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arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n",
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*cptr);
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}
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} else {
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arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n",
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arp->ar_hln, arp->ar_pln);
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dev->stats.rx_errors++;
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dev->stats.rx_crc_errors++;
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}
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}
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if (BUGLVL(D_SKB))
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arcnet_dump_skb(dev, skb, "rx");
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skb->protocol = type_trans(skb, dev);
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netif_rx(skb);
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} else { /* split packet */
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/* NOTE: MSDOS ARP packet correction should only need to
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* apply to unsplit packets, since ARP packets are so short.
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*
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* My interpretation of the RFC1201 document is that if a
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* packet is received out of order, the entire assembly
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* process should be aborted.
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*
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* The RFC also mentions "it is possible for successfully
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* received packets to be retransmitted." As of 0.40 all
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* previously received packets are allowed, not just the
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* most recent one.
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*
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* We allow multiple assembly processes, one for each
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* ARCnet card possible on the network.
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* Seems rather like a waste of memory, but there's no
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* other way to be reliable.
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*/
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arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n",
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soft->split_flag, in->sequence);
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if (in->skb && in->sequence != soft->sequence) {
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arc_printk(D_EXTRA, dev, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
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saddr, in->sequence, soft->sequence,
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soft->split_flag);
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dev_kfree_skb_irq(in->skb);
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in->skb = NULL;
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dev->stats.rx_errors++;
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dev->stats.rx_missed_errors++;
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in->lastpacket = in->numpackets = 0;
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}
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if (soft->split_flag & 1) { /* first packet in split */
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arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n",
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soft->split_flag);
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if (in->skb) { /* already assembling one! */
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arc_printk(D_EXTRA, dev, "aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n",
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in->sequence, soft->split_flag,
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soft->sequence);
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dev->stats.rx_errors++;
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dev->stats.rx_missed_errors++;
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dev_kfree_skb_irq(in->skb);
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}
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in->sequence = soft->sequence;
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in->numpackets = ((unsigned)soft->split_flag >> 1) + 2;
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in->lastpacket = 1;
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if (in->numpackets > 16) {
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arc_printk(D_EXTRA, dev, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
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soft->split_flag);
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lp->rfc1201.aborted_seq = soft->sequence;
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dev->stats.rx_errors++;
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dev->stats.rx_length_errors++;
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return;
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}
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in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
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GFP_ATOMIC);
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if (!skb) {
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arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n");
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lp->rfc1201.aborted_seq = soft->sequence;
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dev->stats.rx_dropped++;
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return;
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}
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skb->dev = dev;
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pkt = (struct archdr *)skb->data;
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soft = &pkt->soft.rfc1201;
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memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
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skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
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soft->split_flag = 0; /* end result won't be split */
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} else { /* not first packet */
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int packetnum = ((unsigned)soft->split_flag >> 1) + 1;
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/* if we're not assembling, there's no point trying to
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* continue.
|
*/
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if (!in->skb) {
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if (lp->rfc1201.aborted_seq != soft->sequence) {
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arc_printk(D_EXTRA, dev, "can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n",
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soft->split_flag,
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soft->sequence,
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lp->rfc1201.aborted_seq);
|
dev->stats.rx_errors++;
|
dev->stats.rx_missed_errors++;
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}
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return;
|
}
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in->lastpacket++;
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/* if not the right flag */
|
if (packetnum != in->lastpacket) {
|
/* harmless duplicate? ignore. */
|
if (packetnum <= in->lastpacket - 1) {
|
arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n",
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soft->split_flag);
|
dev->stats.rx_errors++;
|
dev->stats.rx_frame_errors++;
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return;
|
}
|
/* "bad" duplicate, kill reassembly */
|
arc_printk(D_EXTRA, dev, "out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n",
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in->sequence, soft->split_flag,
|
soft->sequence);
|
lp->rfc1201.aborted_seq = soft->sequence;
|
dev_kfree_skb_irq(in->skb);
|
in->skb = NULL;
|
dev->stats.rx_errors++;
|
dev->stats.rx_missed_errors++;
|
in->lastpacket = in->numpackets = 0;
|
return;
|
}
|
pkt = (struct archdr *)in->skb->data;
|
soft = &pkt->soft.rfc1201;
|
}
|
|
skb = in->skb;
|
|
lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
|
skb->data + skb->len,
|
length - RFC1201_HDR_SIZE);
|
skb_put(skb, length - RFC1201_HDR_SIZE);
|
|
/* are we done? */
|
if (in->lastpacket == in->numpackets) {
|
in->skb = NULL;
|
in->lastpacket = in->numpackets = 0;
|
|
arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n",
|
skb->len, pkt->hard.source);
|
arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n",
|
skb->len, pkt->hard.source);
|
if (BUGLVL(D_SKB))
|
arcnet_dump_skb(dev, skb, "rx");
|
|
skb->protocol = type_trans(skb, dev);
|
netif_rx(skb);
|
}
|
}
|
}
|
|
/* Create the ARCnet hard/soft headers for RFC1201. */
|
static int build_header(struct sk_buff *skb, struct net_device *dev,
|
unsigned short type, uint8_t daddr)
|
{
|
struct arcnet_local *lp = netdev_priv(dev);
|
int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
|
struct archdr *pkt = skb_push(skb, hdr_size);
|
struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
|
|
/* set the protocol ID according to RFC1201 */
|
switch (type) {
|
case ETH_P_IP:
|
soft->proto = ARC_P_IP;
|
break;
|
case ETH_P_IPV6:
|
soft->proto = ARC_P_IPV6;
|
break;
|
case ETH_P_ARP:
|
soft->proto = ARC_P_ARP;
|
break;
|
case ETH_P_RARP:
|
soft->proto = ARC_P_RARP;
|
break;
|
case ETH_P_IPX:
|
case ETH_P_802_3:
|
case ETH_P_802_2:
|
soft->proto = ARC_P_IPX;
|
break;
|
case ETH_P_ATALK:
|
soft->proto = ARC_P_ATALK;
|
break;
|
default:
|
arc_printk(D_NORMAL, dev, "RFC1201: I don't understand protocol %d (%Xh)\n",
|
type, type);
|
dev->stats.tx_errors++;
|
dev->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;
|
|
soft->sequence = htons(lp->rfc1201.sequence++);
|
soft->split_flag = 0; /* split packets are done elsewhere */
|
|
/* 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.
|
* For now, always broadcasting will probably at least get
|
* packets sent out :)
|
*/
|
pkt->hard.dest = 0;
|
return hdr_size;
|
}
|
/* otherwise, drop in the dest address */
|
pkt->hard.dest = daddr;
|
return hdr_size;
|
}
|
|
static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
|
struct arc_rfc1201 *soft, int softlen, int bufnum)
|
{
|
struct arcnet_local *lp = netdev_priv(dev);
|
int ofs;
|
|
/* assume length <= XMTU: someone should have handled that by now. */
|
|
if (softlen > MinTU) {
|
hard->offset[0] = 0;
|
hard->offset[1] = ofs = 512 - softlen;
|
} else if (softlen > MTU) { /* exception packet - add an extra header */
|
struct arc_rfc1201 excsoft;
|
|
excsoft.proto = soft->proto;
|
excsoft.split_flag = 0xff;
|
excsoft.sequence = htons(0xffff);
|
|
hard->offset[0] = 0;
|
ofs = 512 - softlen;
|
hard->offset[1] = ofs - RFC1201_HDR_SIZE;
|
lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
|
&excsoft, RFC1201_HDR_SIZE);
|
} else {
|
hard->offset[0] = ofs = 256 - softlen;
|
}
|
|
lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
|
lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
|
|
lp->lastload_dest = hard->dest;
|
}
|
|
static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
|
int bufnum)
|
{
|
struct arcnet_local *lp = netdev_priv(dev);
|
const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
|
struct Outgoing *out;
|
|
arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
|
lp->next_tx, lp->cur_tx, bufnum);
|
|
/* hard header is not included in packet length */
|
length -= ARC_HDR_SIZE;
|
pkt->soft.rfc1201.split_flag = 0;
|
|
/* need to do a split packet? */
|
if (length > XMTU) {
|
out = &lp->outgoing;
|
|
out->length = length - RFC1201_HDR_SIZE;
|
out->dataleft = lp->outgoing.length;
|
out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
|
out->segnum = 0;
|
|
arc_printk(D_DURING, dev, "rfc1201 prep_tx: ready for %d-segment split (%d bytes, seq=%d)\n",
|
out->numsegs, out->length,
|
pkt->soft.rfc1201.sequence);
|
|
return 0; /* not done */
|
}
|
/* just load the packet into the buffers and send it off */
|
load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
|
|
return 1; /* done */
|
}
|
|
static int continue_tx(struct net_device *dev, int bufnum)
|
{
|
struct arcnet_local *lp = netdev_priv(dev);
|
struct Outgoing *out = &lp->outgoing;
|
struct arc_hardware *hard = &out->pkt->hard;
|
struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
|
int maxsegsize = XMTU - RFC1201_HDR_SIZE;
|
int seglen;
|
|
arc_printk(D_DURING, dev,
|
"rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
|
out->segnum, out->numsegs, soft->sequence);
|
|
/* the "new" soft header comes right before the data chunk */
|
newsoft = (struct arc_rfc1201 *)
|
(out->pkt->soft.raw + out->length - out->dataleft);
|
|
if (!out->segnum) /* first packet; newsoft == soft */
|
newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
|
else {
|
newsoft->split_flag = out->segnum << 1;
|
newsoft->proto = soft->proto;
|
newsoft->sequence = soft->sequence;
|
}
|
|
seglen = maxsegsize;
|
if (seglen > out->dataleft)
|
seglen = out->dataleft;
|
out->dataleft -= seglen;
|
|
load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
|
|
out->segnum++;
|
if (out->segnum >= out->numsegs)
|
return 1;
|
else
|
return 0;
|
}
|
