imported original firmware WRT54GL_v4.30.11_11_US

1 files changed, 1293 insertions, 0 deletions

diff --git a/release/src/linux/linux/net/ipv4/arp.c b/release/src/linux/linux/net/ipv4/arp.c
new file mode 100644
index 00000000..aecd020a
--- /dev/null
+++ b/release/src/linux/linux/net/ipv4/arp.c
@@ -0,0 +1,1293 @@
+/* linux/net/inet/arp.c
+ *
+ * Version:	$Id: arp.c,v 1.1.1.4 2003/10/14 08:09:32 sparq Exp $
+ *
+ * Copyright (C) 1994 by Florian  La Roche
+ *
+ * This module implements the Address Resolution Protocol ARP (RFC 826),
+ * which is used to convert IP addresses (or in the future maybe other
+ * high-level addresses) into a low-level hardware address (like an Ethernet
+ * address).
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ *		Alan Cox	:	Removed the Ethernet assumptions in 
+ *					Florian's code
+ *		Alan Cox	:	Fixed some small errors in the ARP 
+ *					logic
+ *		Alan Cox	:	Allow >4K in /proc
+ *		Alan Cox	:	Make ARP add its own protocol entry
+ *		Ross Martin     :       Rewrote arp_rcv() and arp_get_info()
+ *		Stephen Henson	:	Add AX25 support to arp_get_info()
+ *		Alan Cox	:	Drop data when a device is downed.
+ *		Alan Cox	:	Use init_timer().
+ *		Alan Cox	:	Double lock fixes.
+ *		Martin Seine	:	Move the arphdr structure
+ *					to if_arp.h for compatibility.
+ *					with BSD based programs.
+ *		Andrew Tridgell :       Added ARP netmask code and
+ *					re-arranged proxy handling.
+ *		Alan Cox	:	Changed to use notifiers.
+ *		Niibe Yutaka	:	Reply for this device or proxies only.
+ *		Alan Cox	:	Don't proxy across hardware types!
+ *		Jonathan Naylor :	Added support for NET/ROM.
+ *		Mike Shaver     :       RFC1122 checks.
+ *		Jonathan Naylor :	Only lookup the hardware address for
+ *					the correct hardware type.
+ *		Germano Caronni	:	Assorted subtle races.
+ *		Craig Schlenter :	Don't modify permanent entry 
+ *					during arp_rcv.
+ *		Russ Nelson	:	Tidied up a few bits.
+ *		Alexey Kuznetsov:	Major changes to caching and behaviour,
+ *					eg intelligent arp probing and 
+ *					generation
+ *					of host down events.
+ *		Alan Cox	:	Missing unlock in device events.
+ *		Eckes		:	ARP ioctl control errors.
+ *		Alexey Kuznetsov:	Arp free fix.
+ *		Manuel Rodriguez:	Gratuitous ARP.
+ *              Jonathan Layes  :       Added arpd support through kerneld 
+ *                                      message queue (960314)
+ *		Mike Shaver	:	/proc/sys/net/ipv4/arp_* support
+ *		Mike McLagan    :	Routing by source
+ *		Stuart Cheshire	:	Metricom and grat arp fixes
+ *					*** FOR 2.1 clean this up ***
+ *		Lawrence V. Stefani: (08/12/96) Added FDDI support.
+ *		Alan Cox 	:	Took the AP1000 nasty FDDI hack and
+ *					folded into the mainstream FDDI code.
+ *					Ack spit, Linus how did you allow that
+ *					one in...
+ *		Jes Sorensen	:	Make FDDI work again in 2.1.x and
+ *					clean up the APFDDI & gen. FDDI bits.
+ *		Alexey Kuznetsov:	new arp state machine;
+ *					now it is in net/core/neighbour.c.
+ *		Krzysztof Halasa:	Added Frame Relay ARP support.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/config.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/fddidevice.h>
+#include <linux/if_arp.h>
+#include <linux/trdevice.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+#include <net/ax25.h>
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+#include <net/netrom.h>
+#endif
+#endif
+#ifdef CONFIG_ATM_CLIP
+#include <net/atmclip.h>
+#endif
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#include <linux/netfilter_arp.h>
+
+/*
+ *	Interface to generic neighbour cache.
+ */
+static u32 arp_hash(const void *pkey, const struct net_device *dev);
+static int arp_constructor(struct neighbour *neigh);
+static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
+static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
+static void parp_redo(struct sk_buff *skb);
+
+static struct neigh_ops arp_generic_ops = {
+	family:			AF_INET,
+	solicit:		arp_solicit,
+	error_report:		arp_error_report,
+	output:			neigh_resolve_output,
+	connected_output:	neigh_connected_output,
+	hh_output:		dev_queue_xmit,
+	queue_xmit:		dev_queue_xmit,
+};
+
+static struct neigh_ops arp_hh_ops = {
+	family:			AF_INET,
+	solicit:		arp_solicit,
+	error_report:		arp_error_report,
+	output:			neigh_resolve_output,
+	connected_output:	neigh_resolve_output,
+	hh_output:		dev_queue_xmit,
+	queue_xmit:		dev_queue_xmit,
+};
+
+static struct neigh_ops arp_direct_ops = {
+	family:			AF_INET,
+	output:			dev_queue_xmit,
+	connected_output:	dev_queue_xmit,
+	hh_output:		dev_queue_xmit,
+	queue_xmit:		dev_queue_xmit,
+};
+
+struct neigh_ops arp_broken_ops = {
+	family:			AF_INET,
+	solicit:		arp_solicit,
+	error_report:		arp_error_report,
+	output:			neigh_compat_output,
+	connected_output:	neigh_compat_output,
+	hh_output:		dev_queue_xmit,
+	queue_xmit:		dev_queue_xmit,
+};
+
+struct neigh_table arp_tbl = {
+	family:		AF_INET,
+	entry_size:	sizeof(struct neighbour) + 4,
+	key_len:	4,
+	hash:		arp_hash,
+	constructor:	arp_constructor,
+	proxy_redo:	parp_redo,
+	id:		"arp_cache",
+	parms: {
+		tbl:			&arp_tbl,
+                /*zhijian 2006-10-23 modify to solve arp entry timeout problem(cdrouter3.3 scaling module)*/
+                #if 0 
+		base_reachable_time:	30 * HZ,
+		retrans_time:		1 * HZ,
+		gc_staletime:		60 * HZ,
+		reachable_time:		30 * HZ,
+		delay_probe_time:	5 * HZ,
+		queue_len:		3,
+		ucast_probes:		3,
+		mcast_probes:		3,
+                #else
+                base_reachable_time:    60 * HZ,
+                retrans_time:           5 * HZ,
+                gc_staletime:           120 * HZ,
+                reachable_time:         60 * HZ,
+                delay_probe_time:       10 * HZ,
+                queue_len:              3,
+                ucast_probes:           6,
+                mcast_probes:           6,
+                #endif
+		anycast_delay:		1 * HZ,
+		proxy_delay:		(8 * HZ) / 10,
+		proxy_qlen:		64,
+		locktime:		1 * HZ,
+	},
+	gc_interval:	30 * HZ,
+	gc_thresh1:	128,
+	gc_thresh2:	512,
+	gc_thresh3:	1024,
+};
+
+int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir)
+{
+	switch (dev->type) {
+	case ARPHRD_ETHER:
+	case ARPHRD_FDDI:
+	case ARPHRD_IEEE802:
+		ip_eth_mc_map(addr, haddr);
+		return 0; 
+	case ARPHRD_IEEE802_TR:
+		ip_tr_mc_map(addr, haddr);
+		return 0;
+	default:
+		if (dir) {
+			memcpy(haddr, dev->broadcast, dev->addr_len);
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+
+static u32 arp_hash(const void *pkey, const struct net_device *dev)
+{
+	u32 hash_val;
+
+	hash_val = *(u32*)pkey;
+	hash_val ^= (hash_val>>16);
+	hash_val ^= hash_val>>8;
+	hash_val ^= hash_val>>3;
+	hash_val = (hash_val^dev->ifindex)&NEIGH_HASHMASK;
+
+	return hash_val;
+}
+
+static int arp_constructor(struct neighbour *neigh)
+{
+	u32 addr = *(u32*)neigh->primary_key;
+	struct net_device *dev = neigh->dev;
+	struct in_device *in_dev = in_dev_get(dev);
+
+	if (in_dev == NULL)
+		return -EINVAL;
+
+	neigh->type = inet_addr_type(addr);
+	if (in_dev->arp_parms)
+		neigh->parms = in_dev->arp_parms;
+
+	in_dev_put(in_dev);
+
+	if (dev->hard_header == NULL) {
+		neigh->nud_state = NUD_NOARP;
+		neigh->ops = &arp_direct_ops;
+		neigh->output = neigh->ops->queue_xmit;
+	} else {
+		/* Good devices (checked by reading texts, but only Ethernet is
+		   tested)
+
+		   ARPHRD_ETHER: (ethernet, apfddi)
+		   ARPHRD_FDDI: (fddi)
+		   ARPHRD_IEEE802: (tr)
+		   ARPHRD_METRICOM: (strip)
+		   ARPHRD_ARCNET:
+		   etc. etc. etc.
+
+		   ARPHRD_IPDDP will also work, if author repairs it.
+		   I did not it, because this driver does not work even
+		   in old paradigm.
+		 */
+
+		/* So... these "amateur" devices are hopeless.
+		   The only thing, that I can say now:
+		   It is very sad that we need to keep ugly obsolete
+		   code to make them happy.
+
+		   They should be moved to more reasonable state, now
+		   they use rebuild_header INSTEAD OF hard_start_xmit!!!
+		   Besides that, they are sort of out of date
+		   (a lot of redundant clones/copies, useless in 2.1),
+		   I wonder why people believe that they work.
+		 */
+		switch (dev->type) {
+		default:
+			break;
+		case ARPHRD_ROSE:	
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+		case ARPHRD_AX25:
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+		case ARPHRD_NETROM:
+#endif
+			neigh->ops = &arp_broken_ops;
+			neigh->output = neigh->ops->output;
+			return 0;
+#endif
+		;}
+		if (neigh->type == RTN_MULTICAST) {
+			neigh->nud_state = NUD_NOARP;
+			arp_mc_map(addr, neigh->ha, dev, 1);
+		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
+		} else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
+		}
+		if (dev->hard_header_cache)
+			neigh->ops = &arp_hh_ops;
+		else
+			neigh->ops = &arp_generic_ops;
+		if (neigh->nud_state&NUD_VALID)
+			neigh->output = neigh->ops->connected_output;
+		else
+			neigh->output = neigh->ops->output;
+	}
+	return 0;
+}
+
+static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
+{
+	dst_link_failure(skb);
+	kfree_skb(skb);
+}
+
+static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
+{
+	u32 saddr;
+	u8  *dst_ha = NULL;
+	struct net_device *dev = neigh->dev;
+	u32 target = *(u32*)neigh->primary_key;
+	int probes = atomic_read(&neigh->probes);
+
+	if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL)
+		saddr = skb->nh.iph->saddr;
+	else
+		saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
+
+	if ((probes -= neigh->parms->ucast_probes) < 0) {
+		if (!(neigh->nud_state&NUD_VALID))
+			printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
+		dst_ha = neigh->ha;
+		read_lock_bh(&neigh->lock);
+	} else if ((probes -= neigh->parms->app_probes) < 0) {
+#ifdef CONFIG_ARPD
+		neigh_app_ns(neigh);
+#endif
+		return;
+	}
+
+	arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
+		 dst_ha, dev->dev_addr, NULL);
+	if (dst_ha)
+		read_unlock_bh(&neigh->lock);
+}
+
+static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev)
+{
+	struct rtable *rt;
+	int flag = 0; 
+	/*unsigned long now; */
+
+	if (ip_route_output(&rt, sip, tip, 0, 0) < 0) 
+		return 1;
+	if (rt->u.dst.dev != dev) { 
+		NET_INC_STATS_BH(ArpFilter);
+		flag = 1;
+	} 
+	ip_rt_put(rt); 
+	return flag; 
+} 
+
+/* OBSOLETE FUNCTIONS */
+
+/*
+ *	Find an arp mapping in the cache. If not found, post a request.
+ *
+ *	It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
+ *	even if it exists. It is supposed that skb->dev was mangled
+ *	by a virtual device (eql, shaper). Nobody but broken devices
+ *	is allowed to use this function, it is scheduled to be removed. --ANK
+ */
+
+static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev)
+{
+	switch (addr_hint) {
+	case RTN_LOCAL:
+		printk(KERN_DEBUG "ARP: arp called for own IP address\n");
+		memcpy(haddr, dev->dev_addr, dev->addr_len);
+		return 1;
+	case RTN_MULTICAST:
+		arp_mc_map(paddr, haddr, dev, 1);
+		return 1;
+	case RTN_BROADCAST:
+		memcpy(haddr, dev->broadcast, dev->addr_len);
+		return 1;
+	}
+	return 0;
+}
+
+
+int arp_find(unsigned char *haddr, struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	u32 paddr;
+	struct neighbour *n;
+
+	if (!skb->dst) {
+		printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
+		kfree_skb(skb);
+		return 1;
+	}
+
+	paddr = ((struct rtable*)skb->dst)->rt_gateway;
+
+	if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev))
+		return 0;
+
+	n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
+
+	if (n) {
+		n->used = jiffies;
+		if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
+			read_lock_bh(&n->lock);
+ 			memcpy(haddr, n->ha, dev->addr_len);
+			read_unlock_bh(&n->lock);
+			neigh_release(n);
+			return 0;
+		}
+		neigh_release(n);
+	} else
+		kfree_skb(skb);
+	return 1;
+}
+
+/* END OF OBSOLETE FUNCTIONS */
+
+int arp_bind_neighbour(struct dst_entry *dst)
+{
+	struct net_device *dev = dst->dev;
+	struct neighbour *n = dst->neighbour;
+
+	if (dev == NULL)
+		return -EINVAL;
+	if (n == NULL) {
+		u32 nexthop = ((struct rtable*)dst)->rt_gateway;
+		if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
+			nexthop = 0;
+		n = __neigh_lookup_errno(
+#ifdef CONFIG_ATM_CLIP
+		    dev->type == ARPHRD_ATM ? &clip_tbl :
+#endif
+		    &arp_tbl, &nexthop, dev);
+		if (IS_ERR(n))
+			return PTR_ERR(n);
+		dst->neighbour = n;
+	}
+	return 0;
+}
+
+/*
+ * Check if we can use proxy ARP for this path
+ */
+
+static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
+{
+	struct in_device *out_dev;
+	int imi, omi = -1;
+
+	if (!IN_DEV_PROXY_ARP(in_dev))
+		return 0;
+
+	if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
+		return 1;
+	if (imi == -1)
+		return 0;
+
+	/* place to check for proxy_arp for routes */
+
+	if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
+		omi = IN_DEV_MEDIUM_ID(out_dev);
+		in_dev_put(out_dev);
+	}
+	return (omi != imi && omi != -1);
+}
+
+/*
+ *	Interface to link layer: send routine and receive handler.
+ */
+
+/*
+ *	Create and send an arp packet. If (dest_hw == NULL), we create a broadcast
+ *	message.
+ */
+
+void arp_send(int type, int ptype, u32 dest_ip, 
+	      struct net_device *dev, u32 src_ip, 
+	      unsigned char *dest_hw, unsigned char *src_hw,
+	      unsigned char *target_hw)
+{
+	struct sk_buff *skb;
+	struct arphdr *arp;
+	unsigned char *arp_ptr;
+
+	/*
+	 *	No arp on this interface.
+	 */
+	
+	if (dev->flags&IFF_NOARP)
+		return;
+
+	/*
+	 *	Allocate a buffer
+	 */
+	
+	skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
+				+ dev->hard_header_len + 15, GFP_ATOMIC);
+	if (skb == NULL)
+		return;
+
+	skb_reserve(skb, (dev->hard_header_len+15)&~15);
+	skb->nh.raw = skb->data;
+	arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
+	skb->dev = dev;
+	skb->protocol = htons (ETH_P_ARP);
+	if (src_hw == NULL)
+		src_hw = dev->dev_addr;
+	if (dest_hw == NULL)
+		dest_hw = dev->broadcast;
+
+	/*
+	 *	Fill the device header for the ARP frame
+	 */
+	if (dev->hard_header &&
+	    dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0)
+		goto out;
+
+	/*
+	 * Fill out the arp protocol part.
+	 *
+	 * The arp hardware type should match the device type, except for FDDI,
+	 * which (according to RFC 1390) should always equal 1 (Ethernet).
+	 */
+	/*
+	 *	Exceptions everywhere. AX.25 uses the AX.25 PID value not the
+	 *	DIX code for the protocol. Make these device structure fields.
+	 */
+	switch (dev->type) {
+	default:
+		arp->ar_hrd = htons(dev->type);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+	case ARPHRD_AX25:
+		arp->ar_hrd = htons(ARPHRD_AX25);
+		arp->ar_pro = htons(AX25_P_IP);
+		break;
+
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+	case ARPHRD_NETROM:
+		arp->ar_hrd = htons(ARPHRD_NETROM);
+		arp->ar_pro = htons(AX25_P_IP);
+		break;
+#endif
+#endif
+
+#ifdef CONFIG_FDDI
+	case ARPHRD_FDDI:
+		arp->ar_hrd = htons(ARPHRD_ETHER);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+#endif
+#ifdef CONFIG_TR
+	case ARPHRD_IEEE802_TR:
+		arp->ar_hrd = htons(ARPHRD_IEEE802);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+#endif
+	}
+
+	arp->ar_hln = dev->addr_len;
+	arp->ar_pln = 4;
+	arp->ar_op = htons(type);
+
+	arp_ptr=(unsigned char *)(arp+1);
+
+	memcpy(arp_ptr, src_hw, dev->addr_len);
+	arp_ptr+=dev->addr_len;
+	memcpy(arp_ptr, &src_ip,4);
+	arp_ptr+=4;
+	if (target_hw != NULL)
+		memcpy(arp_ptr, target_hw, dev->addr_len);
+	else
+		memset(arp_ptr, 0, dev->addr_len);
+	arp_ptr+=dev->addr_len;
+	memcpy(arp_ptr, &dest_ip, 4);
+
+	/* Send it off, maybe filter it using firewalling first.  */
+	NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, dev, dev_queue_xmit);
+	return;
+
+out:
+	kfree_skb(skb);
+}
+
+static void parp_redo(struct sk_buff *skb)
+{
+	arp_rcv(skb, skb->dev, NULL);
+}
+
+/*
+ *	Process an arp request.
+ */
+
+int arp_process(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev = in_dev_get(dev);
+	struct arphdr *arp;
+	unsigned char *arp_ptr;
+	struct rtable *rt;
+	unsigned char *sha, *tha;
+	u32 sip, tip;
+	u16 dev_type = dev->type;
+	int addr_type;
+	struct neighbour *n;
+
+	/* arp_rcv below verifies the ARP header, verifies the device
+	 * is ARP'able, and linearizes the SKB (if needed).
+	 */
+
+	if (in_dev == NULL)
+		goto out;
+
+	arp = skb->nh.arph;
+	arp_ptr= (unsigned char *)(arp+1);
+
+	switch (dev_type) {
+	default:	
+		if (arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		if (htons(dev_type) != arp->ar_hrd)
+			goto out;
+		break;
+#ifdef CONFIG_NET_ETHERNET
+	case ARPHRD_ETHER:
+		/*
+		 * ETHERNET devices will accept ARP hardware types of either
+		 * 1 (Ethernet) or 6 (IEEE 802.2).
+		 */
+		if (arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		    arp->ar_hrd != htons(ARPHRD_IEEE802))
+			goto out;
+		if (arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		break;
+#endif
+#ifdef CONFIG_TR
+	case ARPHRD_IEEE802_TR:
+		/*
+		 * Token ring devices will accept ARP hardware types of either
+		 * 1 (Ethernet) or 6 (IEEE 802.2).
+		 */
+		if (arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		    arp->ar_hrd != htons(ARPHRD_IEEE802))
+			goto out;
+		if (arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		break;
+#endif
+#ifdef CONFIG_FDDI
+	case ARPHRD_FDDI:
+		/*
+		 * According to RFC 1390, FDDI devices should accept ARP hardware types
+		 * of 1 (Ethernet).  However, to be more robust, we'll accept hardware
+		 * types of either 1 (Ethernet) or 6 (IEEE 802.2).
+		 */
+		if (arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		    arp->ar_hrd != htons(ARPHRD_IEEE802))
+			goto out;
+		if (arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		break;
+#endif
+#ifdef CONFIG_NET_FC
+	case ARPHRD_IEEE802:
+		/*
+		 * According to RFC 2625, Fibre Channel devices (which are IEEE
+		 * 802 devices) should accept ARP hardware types of 6 (IEEE 802)
+		 * and 1 (Ethernet).
+		 */
+		if (arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		    arp->ar_hrd != htons(ARPHRD_IEEE802))
+			goto out;
+		if (arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		break;
+#endif
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+	case ARPHRD_AX25:
+		if (arp->ar_pro != htons(AX25_P_IP))
+			goto out;
+		if (arp->ar_hrd != htons(ARPHRD_AX25))
+			goto out;
+		break;
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+	case ARPHRD_NETROM:
+		if (arp->ar_pro != htons(AX25_P_IP))
+			goto out;
+		if (arp->ar_hrd != htons(ARPHRD_NETROM))
+			goto out;
+		break;
+#endif
+#endif
+	}
+
+	/* Understand only these message types */
+
+	if (arp->ar_op != htons(ARPOP_REPLY) &&
+	    arp->ar_op != htons(ARPOP_REQUEST))
+		goto out;
+
+/*
+ *	Extract fields
+ */
+	sha=arp_ptr;
+	arp_ptr += dev->addr_len;
+	memcpy(&sip, arp_ptr, 4);
+	arp_ptr += 4;
+	tha=arp_ptr;
+	arp_ptr += dev->addr_len;
+	memcpy(&tip, arp_ptr, 4);
+/* 
+ *	Check for bad requests for 127.x.x.x and requests for multicast
+ *	addresses.  If this is one such, delete it.
+ */
+	if (LOOPBACK(tip) || MULTICAST(tip))
+		goto out;
+
+/*
+ *     Special case: We must set Frame Relay source Q.922 address
+ */
+	if (dev_type == ARPHRD_DLCI)
+		sha = dev->broadcast;
+
+/*
+ *  Process entry.  The idea here is we want to send a reply if it is a
+ *  request for us or if it is a request for someone else that we hold
+ *  a proxy for.  We want to add an entry to our cache if it is a reply
+ *  to us or if it is a request for our address.  
+ *  (The assumption for this last is that if someone is requesting our 
+ *  address, they are probably intending to talk to us, so it saves time 
+ *  if we cache their address.  Their address is also probably not in 
+ *  our cache, since ours is not in their cache.)
+ * 
+ *  Putting this another way, we only care about replies if they are to
+ *  us, in which case we add them to the cache.  For requests, we care
+ *  about those for us and those for our proxies.  We reply to both,
+ *  and in the case of requests for us we add the requester to the arp 
+ *  cache.
+ */
+
+	/* Special case: IPv4 duplicate address detection packet (RFC2131) */
+	if (sip == 0) {
+		if (arp->ar_op == htons(ARPOP_REQUEST) &&
+		    inet_addr_type(tip) == RTN_LOCAL)
+			arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
+		goto out;
+	}
+
+	if (arp->ar_op == htons(ARPOP_REQUEST) &&
+	    ip_route_input(skb, tip, sip, 0, dev) == 0) {
+
+		rt = (struct rtable*)skb->dst;
+		addr_type = rt->rt_type;
+
+		if (addr_type == RTN_LOCAL) {
+			n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
+			if (n) {
+				int dont_send = 0;
+				if (IN_DEV_ARPFILTER(in_dev))
+					dont_send |= arp_filter(sip,tip,dev); 
+				if (!dont_send)
+					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
+
+				neigh_release(n);
+			}
+			goto out;
+		} else if (IN_DEV_FORWARD(in_dev)) {
+			if ((rt->rt_flags&RTCF_DNAT) ||
+			    (addr_type == RTN_UNICAST  && rt->u.dst.dev != dev &&
+			     (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
+				n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
+				if (n)
+					neigh_release(n);
+
+				if (skb->stamp.tv_sec == 0 ||
+				    skb->pkt_type == PACKET_HOST ||
+				    in_dev->arp_parms->proxy_delay == 0) {
+					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
+				} else {
+					pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
+					in_dev_put(in_dev);
+					return 0;
+				}
+				goto out;
+			}
+		}
+	}
+
+	/* Update our ARP tables */
+
+	n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
+
+#ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP
+	/* Unsolicited ARP is not accepted by default.
+	   It is possible, that this option should be enabled for some
+	   devices (strip is candidate)
+	 */
+	if (n == NULL &&
+	    arp->ar_op == htons(ARPOP_REPLY) &&
+	    inet_addr_type(sip) == RTN_UNICAST)
+		n = __neigh_lookup(&arp_tbl, &sip, dev, -1);
+#endif
+
+	if (n) {
+		int state = NUD_REACHABLE;
+		int override = 0;
+
+		/* If several different ARP replies follows back-to-back,
+		   use the FIRST one. It is possible, if several proxy
+		   agents are active. Taking the first reply prevents
+		   arp trashing and chooses the fastest router.
+		 */
+		if (jiffies - n->updated >= n->parms->locktime)
+			override = 1;
+
+		/* Broadcast replies and request packets
+		   do not assert neighbour reachability.
+		 */
+		if (arp->ar_op != htons(ARPOP_REPLY) ||
+		    skb->pkt_type != PACKET_HOST)
+			state = NUD_STALE;
+		neigh_update(n, sha, state, override, 1);
+		neigh_release(n);
+	}
+
+out:
+	if (in_dev)
+		in_dev_put(in_dev);
+	kfree_skb(skb);
+	return 0;
+}
+
+
+/*
+ *	Receive an arp request from the device layer.
+ */
+
+int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
+{
+	struct arphdr *arp = skb->nh.arph;
+
+	if (arp->ar_hln != dev->addr_len ||
+	    dev->flags & IFF_NOARP ||
+	    skb->pkt_type == PACKET_OTHERHOST ||
+	    skb->pkt_type == PACKET_LOOPBACK ||
+	    arp->ar_pln != 4)
+		goto freeskb;
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+		goto out_of_mem;
+
+	if (skb_is_nonlinear(skb)) {
+		if (skb_linearize(skb, GFP_ATOMIC) != 0)
+			goto freeskb;
+	}
+
+	return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
+
+freeskb:
+	kfree_skb(skb);
+out_of_mem:
+	return 0;
+}
+
+/*
+ *	User level interface (ioctl, /proc)
+ */
+
+/*
+ *	Set (create) an ARP cache entry.
+ */
+
+int arp_req_set(struct arpreq *r, struct net_device * dev)
+{
+	u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
+	struct neighbour *neigh;
+	int err;
+
+	if (r->arp_flags&ATF_PUBL) {
+		u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
+		if (mask && mask != 0xFFFFFFFF)
+			return -EINVAL;
+		if (!dev && (r->arp_flags & ATF_COM)) {
+			dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data);
+			if (!dev)
+				return -ENODEV;
+		}
+		if (mask) {
+			if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
+				return -ENOBUFS;
+			return 0;
+		}
+		if (dev == NULL) {
+			ipv4_devconf.proxy_arp = 1;
+			return 0;
+		}
+		if (__in_dev_get(dev)) {
+			__in_dev_get(dev)->cnf.proxy_arp = 1;
+			return 0;
+		}
+		return -ENXIO;
+	}
+
+	if (r->arp_flags & ATF_PERM)
+		r->arp_flags |= ATF_COM;
+	if (dev == NULL) {
+		struct rtable * rt;
+		if ((err = ip_route_output(&rt, ip, 0, RTO_ONLINK, 0)) != 0)
+			return err;
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+		if (!dev)
+			return -EINVAL;
+	}
+	if (r->arp_ha.sa_family != dev->type)	
+		return -EINVAL;
+
+	neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
+	err = PTR_ERR(neigh);
+	if (!IS_ERR(neigh)) {
+		unsigned state = NUD_STALE;
+		if (r->arp_flags & ATF_PERM)
+			state = NUD_PERMANENT;
+		err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
+				   r->arp_ha.sa_data : NULL, state, 1, 0);
+		neigh_release(neigh);
+	}
+	return err;
+}
+
+static unsigned arp_state_to_flags(struct neighbour *neigh)
+{
+	unsigned flags = 0;
+	if (neigh->nud_state&NUD_PERMANENT)
+		flags = ATF_PERM|ATF_COM;
+	else if (neigh->nud_state&NUD_VALID)
+		flags = ATF_COM;
+	return flags;
+}
+
+/*
+ *	Get an ARP cache entry.
+ */
+
+static int arp_req_get(struct arpreq *r, struct net_device *dev)
+{
+	u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
+	struct neighbour *neigh;
+	int err = -ENXIO;
+
+	neigh = neigh_lookup(&arp_tbl, &ip, dev);
+	if (neigh) {
+		read_lock_bh(&neigh->lock);
+		memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
+		r->arp_flags = arp_state_to_flags(neigh);
+		read_unlock_bh(&neigh->lock);
+		r->arp_ha.sa_family = dev->type;
+		strncpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
+		neigh_release(neigh);
+		err = 0;
+	}
+	return err;
+}
+
+int arp_req_delete(struct arpreq *r, struct net_device * dev)
+{
+	int err;
+	u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
+	struct neighbour *neigh;
+
+	if (r->arp_flags & ATF_PUBL) {
+		u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
+		if (mask == 0xFFFFFFFF)
+			return pneigh_delete(&arp_tbl, &ip, dev);
+		if (mask == 0) {
+			if (dev == NULL) {
+				ipv4_devconf.proxy_arp = 0;
+				return 0;
+			}
+			if (__in_dev_get(dev)) {
+				__in_dev_get(dev)->cnf.proxy_arp = 0;
+				return 0;
+			}
+			return -ENXIO;
+		}
+		return -EINVAL;
+	}
+
+	if (dev == NULL) {
+		struct rtable * rt;
+		if ((err = ip_route_output(&rt, ip, 0, RTO_ONLINK, 0)) != 0)
+			return err;
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+		if (!dev)
+			return -EINVAL;
+	}
+	err = -ENXIO;
+	neigh = neigh_lookup(&arp_tbl, &ip, dev);
+	if (neigh) {
+		if (neigh->nud_state&~NUD_NOARP)
+			err = neigh_update(neigh, NULL, NUD_FAILED, 1, 0);
+		neigh_release(neigh);
+	}
+	return err;
+}
+
+/*
+ *	Handle an ARP layer I/O control request.
+ */
+
+int arp_ioctl(unsigned int cmd, void *arg)
+{
+	int err;
+	struct arpreq r;
+	struct net_device * dev = NULL;
+
+	switch(cmd) {
+		case SIOCDARP:
+		case SIOCSARP:
+			if (!capable(CAP_NET_ADMIN))
+				return -EPERM;
+		case SIOCGARP:
+			err = copy_from_user(&r, arg, sizeof(struct arpreq));
+			if (err)
+				return -EFAULT;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	if (r.arp_pa.sa_family != AF_INET)
+		return -EPFNOSUPPORT;
+
+	if (!(r.arp_flags & ATF_PUBL) &&
+	    (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
+		return -EINVAL;
+	if (!(r.arp_flags & ATF_NETMASK))
+		((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr=htonl(0xFFFFFFFFUL);
+
+	rtnl_lock();
+	if (r.arp_dev[0]) {
+		err = -ENODEV;
+		if ((dev = __dev_get_by_name(r.arp_dev)) == NULL)
+			goto out;
+
+		/* Mmmm... It is wrong... ARPHRD_NETROM==0 */
+		if (!r.arp_ha.sa_family)
+			r.arp_ha.sa_family = dev->type;
+		err = -EINVAL;
+		if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
+			goto out;
+	} else if (cmd == SIOCGARP) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	switch(cmd) {
+	case SIOCDARP:
+	        err = arp_req_delete(&r, dev);
+		break;
+	case SIOCSARP:
+		err = arp_req_set(&r, dev);
+		break;
+	case SIOCGARP:
+		err = arp_req_get(&r, dev);
+		if (!err && copy_to_user(arg, &r, sizeof(r)))
+			err = -EFAULT;
+		break;
+	}
+out:
+	rtnl_unlock();
+	return err;
+}
+
+/*
+ *	Write the contents of the ARP cache to a PROCfs file.
+ */
+#ifndef CONFIG_PROC_FS
+static int arp_get_info(char *buffer, char **start, off_t offset, int length) { return 0; }
+#else
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+static char *ax2asc2(ax25_address *a, char *buf);
+#endif
+#define HBUFFERLEN 30
+
+static int arp_get_info(char *buffer, char **start, off_t offset, int length)
+{
+	int len=0;
+	off_t pos=0;
+	int size;
+	char hbuffer[HBUFFERLEN];
+	int i,j,k;
+	const char hexbuf[] =  "0123456789ABCDEF";
+
+	size = sprintf(buffer,"IP address       HW type     Flags       HW address            Mask     Device\n");
+
+	pos+=size;
+	len+=size;
+
+	for(i=0; i<=NEIGH_HASHMASK; i++) {
+		struct neighbour *n;
+		read_lock_bh(&arp_tbl.lock);
+		for (n=arp_tbl.hash_buckets[i]; n; n=n->next) {
+			struct net_device *dev = n->dev;
+			int hatype = dev->type;
+
+			/* Do not confuse users "arp -a" with magic entries */
+			if (!(n->nud_state&~NUD_NOARP))
+				continue;
+
+			read_lock(&n->lock);
+
+/*
+ *	Convert hardware address to XX:XX:XX:XX ... form.
+ */
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+			if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
+				ax2asc2((ax25_address *)n->ha, hbuffer);
+			else {
+#endif
+			for (k=0,j=0;k<HBUFFERLEN-3 && j<dev->addr_len;j++) {
+				hbuffer[k++]=hexbuf[(n->ha[j]>>4)&15 ];
+				hbuffer[k++]=hexbuf[n->ha[j]&15     ];
+				hbuffer[k++]=':';
+			}
+			hbuffer[--k]=0;
+
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+		}
+#endif
+
+			{
+				char tbuf[16];
+				sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
+				size = sprintf(buffer+len, "%-16s 0x%-10x0x%-10x%s"
+							"     *        %s\n",
+					tbuf,
+					hatype,
+					arp_state_to_flags(n), 
+					hbuffer,
+					dev->name);
+			}
+
+			read_unlock(&n->lock);
+
+			len += size;
+			pos += size;
+		  
+			if (pos <= offset)
+				len=0;
+			if (pos >= offset+length) {
+				read_unlock_bh(&arp_tbl.lock);
+ 				goto done;
+			}
+		}
+		read_unlock_bh(&arp_tbl.lock);
+	}
+
+	for (i=0; i<=PNEIGH_HASHMASK; i++) {
+		struct pneigh_entry *n;
+		for (n=arp_tbl.phash_buckets[i]; n; n=n->next) {
+			struct net_device *dev = n->dev;
+			int hatype = dev ? dev->type : 0;
+
+			{
+				char tbuf[16];
+				sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
+				size = sprintf(buffer+len, "%-16s 0x%-10x0x%-10x%s"
+							"     *        %s\n",
+					tbuf,
+					hatype,
+ 					ATF_PUBL|ATF_PERM,
+					"00:00:00:00:00:00",
+					dev ? dev->name : "*");
+			}
+
+			len += size;
+			pos += size;
+		  
+			if (pos <= offset)
+				len=0;
+			if (pos >= offset+length)
+				goto done;
+		}
+	}
+
+done:
+  
+	*start = buffer+len-(pos-offset);	/* Start of wanted data */
+	len = pos-offset;			/* Start slop */
+	if (len>length)
+		len = length;			/* Ending slop */
+	if (len<0)
+		len = 0;
+	return len;
+}
+#endif
+
+/* Note, that it is not on notifier chain.
+   It is necessary, that this routine was called after route cache will be
+   flushed.
+ */
+void arp_ifdown(struct net_device *dev)
+{
+	neigh_ifdown(&arp_tbl, dev);
+}
+
+
+/*
+ *	Called once on startup.
+ */
+
+static struct packet_type arp_packet_type = {
+	type:	__constant_htons(ETH_P_ARP),
+	func:	arp_rcv,
+	data:	(void*) 1, /* understand shared skbs */
+};
+
+void __init arp_init (void)
+{
+	neigh_table_init(&arp_tbl);
+
+	dev_add_pack(&arp_packet_type);
+
+	proc_net_create ("arp", 0, arp_get_info);
+
+#ifdef CONFIG_SYSCTL
+	neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, NET_IPV4_NEIGH, "ipv4");
+#endif
+}
+
+
+#ifdef CONFIG_PROC_FS
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+
+/*
+ *	ax25 -> ASCII conversion
+ */
+char *ax2asc2(ax25_address *a, char *buf)
+{
+	char c, *s;
+	int n;
+
+	for (n = 0, s = buf; n < 6; n++) {
+		c = (a->ax25_call[n] >> 1) & 0x7F;
+
+		if (c != ' ') *s++ = c;
+	}
+	
+	*s++ = '-';
+
+	if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
+		*s++ = '1';
+		n -= 10;
+	}
+	
+	*s++ = n + '0';
+	*s++ = '\0';
+
+	if (*buf == '\0' || *buf == '-')
+	   return "*";
+
+	return buf;
+
+}
+
+#endif
+#endif