/***
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*
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* stack/eth.c - Ethernet-specific functions
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*
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* Copyright (C) 2002 Ulrich Marx <marx@kammer.uni-hannover.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/skbuff.h>
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#include <rtdev.h>
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#include <rtnet_internal.h>
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/*
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* Create the Ethernet MAC header for an arbitrary protocol layer
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*
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* saddr=NULL means use device source address
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* daddr=NULL means leave destination address (eg unresolved arp)
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*/
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int rt_eth_header(struct rtskb *skb, struct rtnet_device *rtdev,
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unsigned short type, void *daddr, void *saddr, unsigned len)
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{
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struct ethhdr *eth = (struct ethhdr *)rtskb_push(skb, ETH_HLEN);
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/*
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* Set rtskb mac field
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*/
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skb->mac.ethernet = eth;
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/*
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* Set the protocol type. For a packet of type ETH_P_802_3 we put the length
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* in here instead. It is up to the 802.2 layer to carry protocol information.
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*/
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if (type != ETH_P_802_3)
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eth->h_proto = htons(type);
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else
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eth->h_proto = htons(len);
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/*
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* Set the source hardware address.
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*/
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if (saddr)
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memcpy(eth->h_source, saddr, rtdev->addr_len);
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else
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memcpy(eth->h_source, rtdev->dev_addr, rtdev->addr_len);
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if (rtdev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
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memset(eth->h_dest, 0, rtdev->addr_len);
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return rtdev->hard_header_len;
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}
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if (daddr) {
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memcpy(eth->h_dest, daddr, rtdev->addr_len);
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return rtdev->hard_header_len;
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}
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return -rtdev->hard_header_len;
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}
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unsigned short rt_eth_type_trans(struct rtskb *skb, struct rtnet_device *rtdev)
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{
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struct ethhdr *eth;
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unsigned char *rawp;
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rtcap_mark_incoming(skb);
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skb->mac.raw = skb->data;
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rtskb_pull(skb, rtdev->hard_header_len);
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eth = skb->mac.ethernet;
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if (*eth->h_dest & 1) {
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if (memcmp(eth->h_dest, rtdev->broadcast, ETH_ALEN) == 0)
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skb->pkt_type = PACKET_BROADCAST;
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else
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skb->pkt_type = PACKET_MULTICAST;
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}
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/*
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* This ALLMULTI check should be redundant by 1.4
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* so don't forget to remove it.
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*
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* Seems, you forgot to remove it. All silly devices
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* seems to set IFF_PROMISC.
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*/
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else if (1 /*rtdev->flags&IFF_PROMISC*/) {
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if (memcmp(eth->h_dest, rtdev->dev_addr, ETH_ALEN))
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skb->pkt_type = PACKET_OTHERHOST;
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}
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if (ntohs(eth->h_proto) >= 1536)
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return eth->h_proto;
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rawp = skb->data;
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/*
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* This is a magic hack to spot IPX packets. Older Novell breaks
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* the protocol design and runs IPX over 802.3 without an 802.2 LLC
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* layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
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* won't work for fault tolerant netware but does for the rest.
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*/
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if (*(unsigned short *)rawp == 0xFFFF)
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return htons(ETH_P_802_3);
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/*
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* Real 802.2 LLC
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*/
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return htons(ETH_P_802_2);
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}
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EXPORT_SYMBOL_GPL(rt_eth_header);
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EXPORT_SYMBOL_GPL(rt_eth_type_trans);
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