patch-2.3.15 linux/net/ipv4/rarp.c

• Lines: 607
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.3.14/linux/net/ipv4/rarp.c
• Orig date: Wed Aug 18 11:38:48 1999

diff -u --recursive --new-file v2.3.14/linux/net/ipv4/rarp.c linux/net/ipv4/rarp.c
@@ -1,606 +0,0 @@
-/* linux/net/inet/rarp.c
- *
- * Copyright (C) 1994 by Ross Martin
- * Based on linux/net/inet/arp.c, Copyright (C) 1994 by Florian La Roche
- *
- * $Id: rarp.c,v 1.25 1998/06/19 13:22:34 davem Exp $
- *
- * This module implements the Reverse Address Resolution Protocol 
- * (RARP, RFC 903), which is used to convert low level addresses such
- * as Ethernet addresses into high level addresses such as IP addresses.
- * The most common use of RARP is as a means for a diskless workstation 
- * to discover its IP address during a network boot.
- *
- **
- ***	WARNING:::::::::::::::::::::::::::::::::WARNING
- ****
- *****	SUN machines seem determined to boot solely from the person who
- ****	answered their RARP query. NEVER add a SUN to your RARP table
- ***	unless you have all the rest to boot the box from it. 
- **
- * 
- * Currently, only Ethernet address -> IP address is likely to work.
- * (Is RARP ever used for anything else?)
- *
- * This code 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	:	Rarp delete on device down needed as
- *				reported by Walter Wolfgang.
- *	Mike McLagan	:	Routing by source
- *
- */
-
-#include <linux/module.h>
-
-#include <linux/types.h>
-#include <linux/string.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/socket.h>
-#include <linux/sockios.h>
-#include <linux/errno.h>
-#include <linux/netdevice.h>
-#include <linux/if_arp.h>
-#include <linux/in.h>
-#include <linux/config.h>
-#include <linux/init.h>
-
-#include <asm/system.h>
-#include <asm/uaccess.h>
-#include <stdarg.h>
-#include <linux/inet.h>
-#include <linux/etherdevice.h>
-#include <net/ip.h>
-#include <net/route.h>
-#include <net/protocol.h>
-#include <net/tcp.h>
-#include <linux/skbuff.h>
-#include <net/sock.h>
-#include <net/arp.h>
-#include <net/rarp.h>
-#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
-#include <net/ax25.h>
-#endif
-#include <linux/proc_fs.h>
-#include <linux/stat.h>
-
-extern int (*rarp_ioctl_hook)(unsigned int,void*);
-
-/*
- *	This structure defines the RARP mapping cache. As long as we make 
- *	changes in this structure, we keep interrupts off.
- */
-
-struct rarp_table
-{
-	struct rarp_table  *next;             /* Linked entry list           */
-	unsigned long      ip;                /* ip address of entry         */
-	unsigned char      ha[MAX_ADDR_LEN];  /* Hardware address            */
-	unsigned char      hlen;              /* Length of hardware address  */
-	unsigned char      htype;             /* Type of hardware in use     */
-	struct net_device      *dev;              /* Device the entry is tied to */
-};
-
-struct rarp_table *rarp_tables = NULL;
-
-static int rarp_rcv(struct sk_buff *, struct net_device *, struct packet_type *);
-
-static struct packet_type rarp_packet_type =
-{
-	0,  /* Should be: __constant_htons(ETH_P_RARP) - but this _doesn't_ come out constant! */
-	0,                /* copy */
-	rarp_rcv,
-	NULL,
-	NULL
-};
-
-static int initflag = 1;
-
-
-/*
- *	Release the memory for this entry.
- */
-
-static inline void rarp_release_entry(struct rarp_table *entry)
-{
-	kfree_s(entry, sizeof(struct rarp_table));
-	MOD_DEC_USE_COUNT;
-	return;
-}
-
-/*
- *	Delete a RARP mapping entry in the cache.
- */
-
-static void rarp_destroy(unsigned long ip_addr)
-{
-	struct rarp_table *entry;
-	struct rarp_table **pentry;
-  
-	start_bh_atomic();
-	pentry = &rarp_tables;
-	while ((entry = *pentry) != NULL)
-	{
-		if (entry->ip == ip_addr)
-		{
-			*pentry = entry->next;
-			end_bh_atomic();
-			rarp_release_entry(entry);
-			return;
-		}
-		pentry = &entry->next;
-	}
-	end_bh_atomic();
-}
-
-/*
- *	Flush a device.
- */
-
-static void rarp_destroy_dev(struct net_device *dev)
-{
-	struct rarp_table *entry;
-	struct rarp_table **pentry;
-  
-	start_bh_atomic();
-	pentry = &rarp_tables;
-	while ((entry = *pentry) != NULL)
-	{
-		if (entry->dev == dev)
-		{
-			*pentry = entry->next;
-			rarp_release_entry(entry);
-		}
-		else
-			pentry = &entry->next;
-	}
-	end_bh_atomic();
-}
-
-static int rarp_device_event(struct notifier_block *this, unsigned long event, void *ptr)
-{
-	if(event!=NETDEV_DOWN)
-		return NOTIFY_DONE;
-	rarp_destroy_dev((struct net_device *)ptr);
-	return NOTIFY_DONE;
-}
-
-/*
- *	Called once when data first added to rarp cache with ioctl.
- */
- 
-static struct notifier_block rarp_dev_notifier={
-	rarp_device_event,
-	NULL,
-	0
-};
-
-static int rarp_pkt_inited=0;
- 
-static void rarp_init_pkt (void)
-{
-	/* Register the packet type */
-	rarp_packet_type.type=htons(ETH_P_RARP);
-	dev_add_pack(&rarp_packet_type);
-	register_netdevice_notifier(&rarp_dev_notifier);
-	rarp_pkt_inited=1;
-}
-
-#ifdef MODULE
-
-static void rarp_end_pkt(void)
-{
-	if(!rarp_pkt_inited)
-		return;
-	dev_remove_pack(&rarp_packet_type);
-	unregister_netdevice_notifier(&rarp_dev_notifier);
-	rarp_pkt_inited=0;
-}
-
-#endif
-
-/*
- *	Receive an arp request by the device layer.  Maybe it should be 
- *	rewritten to use the incoming packet for the reply. The current 
- *	"overhead" time isn't that high...
- */
-
-static int rarp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
-{
-/*
- *	We shouldn't use this type conversion. Check later.
- */
-	struct arphdr *rarp = (struct arphdr *) skb->data;
-	unsigned char *rarp_ptr = skb_pull(skb,sizeof(struct arphdr));
-	struct rarp_table *entry;
-	struct in_device *in_dev = dev->ip_ptr;
-	long sip,tip;
-	unsigned char *sha,*tha;            /* s for "source", t for "target" */
-	
-/*
- *	If this test doesn't pass, it's not IP, or we should ignore it anyway
- */
-
-	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd) 
-		|| dev->flags&IFF_NOARP || !in_dev || !in_dev->ifa_list)
-	{
-		kfree_skb(skb);
-		return 0;
-	}
-
-/*
- *	If it's not a RARP request, delete it.
- */
-	if (rarp->ar_op != htons(ARPOP_RREQUEST))
-	{
-		kfree_skb(skb);
-		return 0;
-	}
-
-/*
- *	For now we will only deal with IP addresses.
- */
-
-	if (
-#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
-		(rarp->ar_pro != htons(AX25_P_IP) && dev->type == ARPHRD_AX25) ||
-#endif
-		(rarp->ar_pro != htons(ETH_P_IP) && dev->type != ARPHRD_AX25)
-		|| rarp->ar_pln != 4)
-	{
-		/*
-		 *	This packet is not for us. Remove it. 
-		 */
-		kfree_skb(skb);
-		return 0;
-	}
-  
-/*
- *	Extract variable width fields
- */
-
-	sha=rarp_ptr;
-	rarp_ptr+=dev->addr_len;
-	memcpy(&sip,rarp_ptr,4);
-	rarp_ptr+=4;
-	tha=rarp_ptr;
-	rarp_ptr+=dev->addr_len;
-	memcpy(&tip,rarp_ptr,4);
-
-/*
- *	Process entry. Use tha for table lookup according to RFC903.
- */
-  
-	for (entry = rarp_tables; entry != NULL; entry = entry->next)
-		if (!memcmp(entry->ha, tha, rarp->ar_hln))
-			break;
-  
-	if (entry != NULL)
-	{
-		sip=entry->ip;
-
-		arp_send(ARPOP_RREPLY, ETH_P_RARP, sip, dev, in_dev->ifa_list->ifa_address, sha, 
-			dev->dev_addr, sha);
-	}
-
-	kfree_skb(skb);
-	return 0;
-}
-
-
-/*
- *	Set (create) a RARP cache entry.
- */
-
-static int rarp_req_set(struct arpreq *req)
-{
-	struct arpreq r;
-	struct rarp_table *entry;
-	struct sockaddr_in *si;
-	int htype, hlen;
-	unsigned long ip;
-	struct rtable *rt;
-	struct net_device * dev;
-	int err; 
-  
-	err = copy_from_user(&r, req, sizeof(r));
-	if (err)
-		return -EFAULT;
-
-	/*
-	 *	We only understand about IP addresses... 
-	 */
-
-	if (r.arp_pa.sa_family != AF_INET)
-		return -EPFNOSUPPORT;
-  
-	switch (r.arp_ha.sa_family) 
-	{
-		case ARPHRD_ETHER:
-			htype = ARPHRD_ETHER;
-			hlen = ETH_ALEN;
-			break;
-#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
-		case ARPHRD_AX25:
-			htype = ARPHRD_AX25;
-			hlen = 7;
-		break;
-#endif
-		default:
-			return -EPFNOSUPPORT;
-	}
-
-	si = (struct sockaddr_in *) &r.arp_pa;
-	ip = si->sin_addr.s_addr;
-	if (ip == 0)
-	{
-		printk(KERN_DEBUG "RARP: SETRARP: requested PA is 0.0.0.0 !\n");
-		return -EINVAL;
-	}
-  
-/*
- *	Is it reachable directly ?
- */
-  
-	err = ip_route_output(&rt, ip, 0, 1, 0);
-	if (err)
-		return err;
-	if (rt->rt_flags&(RTCF_LOCAL|RTCF_BROADCAST|RTCF_MULTICAST|RTCF_DNAT)) {
-		ip_rt_put(rt);
-		return -EINVAL;
-	}
-	dev = rt->u.dst.dev;
-
-/*
- *	Is there an existing entry for this address?  Find out...
- */
-  
-	for (entry = rarp_tables; entry != NULL; entry = entry->next)
-		if (entry->ip == ip)
-			break;
-  
-/*
- *	If no entry was found, create a new one.
- */
-
-	if (entry == NULL)
-	{
-		entry = (struct rarp_table *) kmalloc(sizeof(struct rarp_table),
-				    GFP_ATOMIC);
-		if (entry == NULL)
-		{
-			return -ENOMEM;
-		}
-		if (initflag)
-		{
-			rarp_init_pkt();
-			initflag=0;
-		}
-
-		/* Block interrupts until table modification is finished */
-
-		cli();
-		entry->next = rarp_tables;
-		rarp_tables = entry;
-	}
-	cli();
-	entry->ip = ip;
-	entry->hlen = hlen;
-	entry->htype = htype;
-	memcpy(&entry->ha, &r.arp_ha.sa_data, hlen);
-	entry->dev = dev;
-	sti();
-
-	/* Don't unlink if we have entries to serve. */
-	MOD_INC_USE_COUNT;
-
-	return 0;
-}
-
-
-/*
- *        Get a RARP cache entry.
- */
-
-static int rarp_req_get(struct arpreq *req)
-{
-	struct arpreq r;
-	struct rarp_table *entry;
-	struct sockaddr_in *si;
-	unsigned long ip;
-	int err; 
-	
-/*
- *	We only understand about IP addresses...
- */
-        
-	err = copy_from_user(&r, req, sizeof(r));
-	if (err)
-		return -EFAULT; 
-
-	if (r.arp_pa.sa_family != AF_INET)
-		return -EPFNOSUPPORT;
-  
-/*
- *        Is there an existing entry for this address?
- */
-
-	si = (struct sockaddr_in *) &r.arp_pa;
-	ip = si->sin_addr.s_addr;
-
-	for (entry = rarp_tables; entry != NULL; entry = entry->next)
-		if (entry->ip == ip)
-			break;
-
-	if (entry == NULL)
-	{
-		return -ENXIO;
-	}
-
-/*
- *        We found it; copy into structure.
- */
-        
-	memcpy(r.arp_ha.sa_data, &entry->ha, entry->hlen);
-	r.arp_ha.sa_family = entry->htype;
-  
-/*
- *        Copy the information back
- */
-  
-	return copy_to_user(req, &r, sizeof(r)) ? -EFAULT : 0;
-}
-
-
-/*
- *	Handle a RARP layer I/O control request.
- */
-
-int rarp_ioctl(unsigned int cmd, void *arg)
-{
-	struct arpreq r;
-	struct sockaddr_in *si;
-	int err;
-
-	switch(cmd)
-	{
-		case SIOCDRARP:
-			if (!suser())
-				return -EPERM;
-			err = copy_from_user(&r, arg, sizeof(r));
-			if (err)
-				return -EFAULT; 
-			if (r.arp_pa.sa_family != AF_INET)
-				return -EPFNOSUPPORT;
-			si = (struct sockaddr_in *) &r.arp_pa;
-			rarp_destroy(si->sin_addr.s_addr);
-			return 0;
-
-		case SIOCGRARP:
-
-			return rarp_req_get((struct arpreq *)arg);
-		case SIOCSRARP:
-			if (!suser())
-				return -EPERM;
-			return rarp_req_set((struct arpreq *)arg);
-		default:
-			return -EINVAL;
-	}
-
-	/*NOTREACHED*/
-	return 0;
-}
-
-#ifdef CONFIG_PROC_FS
-int rarp_get_info(char *buffer, char **start, off_t offset, int length, int dummy)
-{
-	int len=0;
-	off_t begin=0;
-	off_t pos=0;
-	int size;
-	struct rarp_table *entry;
-	char ipbuffer[20];
-	unsigned long netip;
-	if (initflag)
-	{
-		size = sprintf(buffer,"RARP disabled until entries added to cache.\n");
-		pos+=size;
-		len+=size;
-	}   
-	else
-	{
-		size = sprintf(buffer,
-			"IP address       HW type             HW address\n");
-		pos+=size;
-		len+=size;
-      
-		for(entry=rarp_tables; entry!=NULL; entry=entry->next)
-		{
-			netip=htonl(entry->ip);          /* switch to network order */
-			sprintf(ipbuffer,"%d.%d.%d.%d",
-				(unsigned int)(netip>>24)&255,
-				(unsigned int)(netip>>16)&255,
-				(unsigned int)(netip>>8)&255,
-				(unsigned int)(netip)&255);
-
-			size = sprintf(buffer+len,
-				"%-17s%-20s%02x:%02x:%02x:%02x:%02x:%02x\n",
-				ipbuffer,
-				"10Mbps Ethernet",
-				(unsigned int)entry->ha[0],
-				(unsigned int)entry->ha[1],
-				(unsigned int)entry->ha[2],
-				(unsigned int)entry->ha[3],
-				(unsigned int)entry->ha[4],
-			 	(unsigned int)entry->ha[5]);
-	  
-			len+=size;
-			pos=begin+len;
-	  
-			if(pos<offset)
-			{
-				len=0;
-				begin=pos;
-			}
-			if(pos>offset+length)
-				break;
-		}
-	}      
-
-	*start = buffer+(offset-begin);	/* Start of wanted data */
-	len   -= (offset-begin);	/* Start slop */
-	if (len>length)
-		len = length;		/* Ending slop */
-	return len;
-}
-
-struct proc_dir_entry proc_net_rarp = {
-	PROC_NET_RARP, 4, "rarp",
-	S_IFREG | S_IRUGO, 1, 0, 0,
-	0, &proc_net_inode_operations,
-	rarp_get_info
-};
-#endif
-
-__initfunc(void
-rarp_init(void))
-{
-#ifdef CONFIG_PROC_FS
-	proc_net_register(&proc_net_rarp);
-#endif
-	rarp_ioctl_hook = rarp_ioctl;
-}
-
-#ifdef MODULE
-
-int init_module(void)
-{
-	rarp_init();
-	return 0;
-}
-
-void cleanup_module(void)
-{
-	struct rarp_table *rt, *rt_next;
-#ifdef CONFIG_PROC_FS
-	proc_net_unregister(PROC_NET_RARP);
-#endif
-	rarp_ioctl_hook = NULL;
-	cli();
-	/* Destroy the RARP-table */
-	rt = rarp_tables;
-	rarp_tables = NULL;
-	sti();
-	/* ... and free it. */
-	for ( ; rt != NULL; rt = rt_next) {
-		rt_next = rt->next;
-		rarp_release_entry(rt);
-	}
-	rarp_end_pkt();
-}
-#endif