427 lines
12 KiB
C
Executable File
427 lines
12 KiB
C
Executable File
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Ethernet-type device handling.
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*
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* Version: @(#)eth.c 1.0.7 05/25/93
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*
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* Authors: Ross Biro
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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* Mark Evans, <evansmp@uhura.aston.ac.uk>
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* Florian La Roche, <rzsfl@rz.uni-sb.de>
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* Alan Cox, <gw4pts@gw4pts.ampr.org>
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*
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* Fixes:
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* Mr Linux : Arp problems
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* Alan Cox : Generic queue tidyup (very tiny here)
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* Alan Cox : eth_header ntohs should be htons
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* Alan Cox : eth_rebuild_header missing an htons and
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* minor other things.
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* Tegge : Arp bug fixes.
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* Florian : Removed many unnecessary functions, code cleanup
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* and changes for new arp and skbuff.
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* Alan Cox : Redid header building to reflect new format.
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* Alan Cox : ARP only when compiled with CONFIG_INET
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* Greg Page : 802.2 and SNAP stuff.
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* Alan Cox : MAC layer pointers/new format.
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* Paul Gortmaker : eth_copy_and_sum shouldn't csum padding.
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* Alan Cox : Protect against forwarding explosions with
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* older network drivers and IFF_ALLMULTI.
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* Christer Weinigel : Better rebuild header message.
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* Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup().
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/ip.h>
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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 <linux/errno.h>
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#include <linux/init.h>
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#include <linux/if_ether.h>
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#include <net/dst.h>
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#include <net/arp.h>
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#include <net/sock.h>
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#include <net/ipv6.h>
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#include <net/ip.h>
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#include <net/dsa.h>
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#include <linux/uaccess.h>
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__setup("ether=", netdev_boot_setup);
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/**
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* eth_header - create the Ethernet header
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* @skb: buffer to alter
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* @dev: source device
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* @type: Ethernet type field
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* @daddr: destination address (NULL leave destination address)
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* @saddr: source address (NULL use device source address)
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* @len: packet length (<= skb->len)
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*
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*
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* Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
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* in here instead.
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*/
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__IMEM int eth_header(struct sk_buff *skb, struct net_device *dev,
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unsigned short type,
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const void *daddr, const void *saddr, unsigned int len)
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{
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struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN);
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if (type != ETH_P_802_3 && type != ETH_P_802_2)
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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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saddr = dev->dev_addr;
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memcpy(eth->h_source, saddr, ETH_ALEN);
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if (daddr) {
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memcpy(eth->h_dest, daddr, ETH_ALEN);
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return ETH_HLEN;
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}
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/*
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* Anyway, the loopback-device should never use this function...
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*/
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if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
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memset(eth->h_dest, 0, ETH_ALEN);
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return ETH_HLEN;
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}
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return -ETH_HLEN;
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}
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EXPORT_SYMBOL(eth_header);
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/**
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* eth_rebuild_header- rebuild the Ethernet MAC header.
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* @skb: socket buffer to update
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*
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* This is called after an ARP or IPV6 ndisc it's resolution on this
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* sk_buff. We now let protocol (ARP) fill in the other fields.
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*
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* This routine CANNOT use cached dst->neigh!
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* Really, it is used only when dst->neigh is wrong.
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*/
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int eth_rebuild_header(struct sk_buff *skb)
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{
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struct ethhdr *eth = (struct ethhdr *)skb->data;
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struct net_device *dev = skb->dev;
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switch (eth->h_proto) {
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#ifdef CONFIG_INET
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case htons(ETH_P_IP):
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return arp_find(eth->h_dest, skb);
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#endif
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default:
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netdev_dbg(dev,
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"%s: unable to resolve type %X addresses.\n",
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dev->name, ntohs(eth->h_proto));
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memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
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break;
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}
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return 0;
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}
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EXPORT_SYMBOL(eth_rebuild_header);
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/**
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* eth_get_headlen - determine the the length of header for an ethernet frame
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* @data: pointer to start of frame
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* @len: total length of frame
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*
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* Make a best effort attempt to pull the length for all of the headers for
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* a given frame in a linear buffer.
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*/
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u32 eth_get_headlen(void *data, unsigned int len)
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{
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const struct ethhdr *eth = (const struct ethhdr *)data;
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struct flow_keys keys;
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/* this should never happen, but better safe than sorry */
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if (len < sizeof(*eth))
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return len;
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/* parse any remaining L2/L3 headers, check for L4 */
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if (!__skb_flow_dissect(NULL, &keys, data,
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eth->h_proto, sizeof(*eth), len))
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return max_t(u32, keys.thoff, sizeof(*eth));
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/* parse for any L4 headers */
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return min_t(u32, __skb_get_poff(NULL, data, &keys, len), len);
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}
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EXPORT_SYMBOL(eth_get_headlen);
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/**
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* eth_type_trans - determine the packet's protocol ID.
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* @skb: received socket data
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* @dev: receiving network device
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*
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* The rule here is that we
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* assume 802.3 if the type field is short enough to be a length.
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* This is normal practice and works for any 'now in use' protocol.
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*/
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__IMEM __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
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{
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unsigned short _service_access_point;
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const unsigned short *sap;
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const struct ethhdr *eth;
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skb->dev = dev;
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skb_reset_mac_header(skb);
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skb_pull_inline(skb, ETH_HLEN);
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eth = eth_hdr(skb);
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if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
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if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
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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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else if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
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dev->dev_addr)))
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skb->pkt_type = PACKET_OTHERHOST;
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/*
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* Some variants of DSA tagging don't have an ethertype field
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* at all, so we check here whether one of those tagging
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* variants has been configured on the receiving interface,
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* and if so, set skb->protocol without looking at the packet.
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*/
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if (unlikely(netdev_uses_dsa(dev)))
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return htons(ETH_P_XDSA);
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if (likely(ntohs(eth->h_proto) >= ETH_P_802_3_MIN))
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return eth->h_proto;
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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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sap = skb_header_pointer(skb, 0, sizeof(*sap), &_service_access_point);
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if (sap && *sap == 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(eth_type_trans);
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/**
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* eth_header_parse - extract hardware address from packet
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* @skb: packet to extract header from
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* @haddr: destination buffer
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*/
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int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
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{
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const struct ethhdr *eth = eth_hdr(skb);
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memcpy(haddr, eth->h_source, ETH_ALEN);
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return ETH_ALEN;
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}
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EXPORT_SYMBOL(eth_header_parse);
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/**
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* eth_header_cache - fill cache entry from neighbour
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* @neigh: source neighbour
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* @hh: destination cache entry
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* @type: Ethernet type field
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*
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* Create an Ethernet header template from the neighbour.
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*/
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int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)
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{
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struct ethhdr *eth;
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const struct net_device *dev = neigh->dev;
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eth = (struct ethhdr *)
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(((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
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if (type == htons(ETH_P_802_3))
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return -1;
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eth->h_proto = type;
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memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
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memcpy(eth->h_dest, neigh->ha, ETH_ALEN);
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hh->hh_len = ETH_HLEN;
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return 0;
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}
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EXPORT_SYMBOL(eth_header_cache);
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/**
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* eth_header_cache_update - update cache entry
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* @hh: destination cache entry
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* @dev: network device
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* @haddr: new hardware address
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*
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* Called by Address Resolution module to notify changes in address.
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*/
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void eth_header_cache_update(struct hh_cache *hh,
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const struct net_device *dev,
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const unsigned char *haddr)
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{
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memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
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haddr, ETH_ALEN);
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}
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EXPORT_SYMBOL(eth_header_cache_update);
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/**
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* eth_prepare_mac_addr_change - prepare for mac change
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* @dev: network device
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* @p: socket address
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*/
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int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
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{
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struct sockaddr *addr = p;
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if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
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return -EBUSY;
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if (!is_valid_ether_addr(addr->sa_data))
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return -EADDRNOTAVAIL;
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return 0;
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}
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EXPORT_SYMBOL(eth_prepare_mac_addr_change);
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/**
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* eth_commit_mac_addr_change - commit mac change
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* @dev: network device
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* @p: socket address
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*/
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void eth_commit_mac_addr_change(struct net_device *dev, void *p)
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{
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struct sockaddr *addr = p;
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memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
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}
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EXPORT_SYMBOL(eth_commit_mac_addr_change);
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/**
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* eth_mac_addr - set new Ethernet hardware address
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* @dev: network device
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* @p: socket address
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*
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* Change hardware address of device.
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*
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* This doesn't change hardware matching, so needs to be overridden
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* for most real devices.
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*/
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int eth_mac_addr(struct net_device *dev, void *p)
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{
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int ret;
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ret = eth_prepare_mac_addr_change(dev, p);
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if (ret < 0)
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return ret;
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eth_commit_mac_addr_change(dev, p);
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return 0;
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}
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EXPORT_SYMBOL(eth_mac_addr);
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/**
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* eth_change_mtu - set new MTU size
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* @dev: network device
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* @new_mtu: new Maximum Transfer Unit
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*
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* Allow changing MTU size. Needs to be overridden for devices
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* supporting jumbo frames.
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*/
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int eth_change_mtu(struct net_device *dev, int new_mtu)
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{
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if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)
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return -EINVAL;
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dev->mtu = new_mtu;
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return 0;
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}
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EXPORT_SYMBOL(eth_change_mtu);
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int eth_validate_addr(struct net_device *dev)
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{
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if (!is_valid_ether_addr(dev->dev_addr))
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return -EADDRNOTAVAIL;
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return 0;
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}
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EXPORT_SYMBOL(eth_validate_addr);
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const struct header_ops eth_header_ops ____cacheline_aligned = {
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.create = eth_header,
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.parse = eth_header_parse,
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.rebuild = eth_rebuild_header,
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.cache = eth_header_cache,
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.cache_update = eth_header_cache_update,
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};
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/**
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* ether_setup - setup Ethernet network device
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* @dev: network device
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*
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* Fill in the fields of the device structure with Ethernet-generic values.
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*/
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void ether_setup(struct net_device *dev)
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{
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dev->header_ops = ð_header_ops;
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dev->type = ARPHRD_ETHER;
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dev->hard_header_len = ETH_HLEN;
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dev->mtu = ETH_DATA_LEN;
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dev->addr_len = ETH_ALEN;
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dev->tx_queue_len = 1000; /* Ethernet wants good queues */
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dev->flags = IFF_BROADCAST|IFF_MULTICAST;
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dev->priv_flags |= IFF_TX_SKB_SHARING;
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memset(dev->broadcast, 0xFF, ETH_ALEN);
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}
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EXPORT_SYMBOL(ether_setup);
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/**
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* alloc_etherdev_mqs - Allocates and sets up an Ethernet device
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* @sizeof_priv: Size of additional driver-private structure to be allocated
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* for this Ethernet device
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* @txqs: The number of TX queues this device has.
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* @rxqs: The number of RX queues this device has.
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*
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* Fill in the fields of the device structure with Ethernet-generic
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* values. Basically does everything except registering the device.
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*
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* Constructs a new net device, complete with a private data area of
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* size (sizeof_priv). A 32-byte (not bit) alignment is enforced for
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* this private data area.
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*/
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struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
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unsigned int rxqs)
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{
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return alloc_netdev_mqs(sizeof_priv, "eth%d", NET_NAME_UNKNOWN,
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ether_setup, txqs, rxqs);
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}
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EXPORT_SYMBOL(alloc_etherdev_mqs);
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ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
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{
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return scnprintf(buf, PAGE_SIZE, "%*phC\n", len, addr);
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}
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EXPORT_SYMBOL(sysfs_format_mac);
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