From: Manu <manuprivat@gmx.de>
To: Jan Engelhardt <jengelh@medozas.de>
Cc: Netfilter Developer Mailing List <netfilter-devel@vger.kernel.org>
Subject: Re: RAWNAT kernel crash
Date: Mon, 28 Jul 2008 13:44:29 +0200 [thread overview]
Message-ID: <488DB11D.3030204@gmx.de> (raw)
In-Reply-To: <488DA720.9060303@gmx.de>
[-- Attachment #1: Type: text/plain, Size: 3735 bytes --]
Hello again,
I forgot to attach the important files :-P
Manu schrieb:
> Hello,
>
> my issue is to connect 2 pc's with different fix IP addresses!
> PC1: 10.0.0.1 and 10.0.17.1
> PC2: 192.168.0.123 with gateway: 192.168.0.1
> I modified the sources of actual RAWNAT
> (xtables-addons-6e918514b752.... ) module from
> http://dev.computergmbh.de/. See attachement!
> I modified the sources of my kernel-2.6.23, as well. See attachment.
>
> Interfaces on PC1:
> eth0: 10.0.0.1
> eth0:2 10.0.17.1
>
> My arptables rules are:
> arptables -A OUTPUT -d 10.0.17.2 -j mangle --mangle-ip-d 192.168.0.123
> --mangle-ip-s 10.0.17.1
> arptables -A INPUT -s 192.168.0.123 -j mangle --mangle-ip-s 10.0.17.2
> --mangle-ip-d 10.0.0.1
>
> My iptables rules are:
> iptables -t raw -I PREROUTING -s 192.168.0.123 -j RAWSNAT --to-source
> 10.0.17.2
> iptables -t rawpost -I POSTROUTING -d 10.0.17.2 -j RAWDNAT
> --to-destination 192.168.0.123
>
> Iptables: 1.4.1.2
> Kernel: 2.6.23
> gcc: 3.3
>
> With "iptables -t rawpost -I POSTROUTING -d 10.0.17.2 -j RAWDNAT
> --to-destination 192.168.0.123", I can succesfully ping PC2 from PC1
> with command "ping 10.0.17.2"!
> tcpdump says:
> 17:54:41.897864 10.0.17.1 > 192.168.0.123: icmp: echo request (DF)
> (ttl 64, id 1, len 84)
> 17:54:41.898156 192.168.0.123 > 10.0.17.1: icmp: echo reply (DF) (ttl
> 128, id 4526, len 84)
>
> But If I want to ping PC1 from PC2 with command "ping 10.0.17.1" and
> with "iptables -t raw -I PREROUTING -s 192.168.0.123 -j RAWSNAT
> --to-source 10.0.17.2" I got a system "crash" (complete hang up) like
> descriped in my former postings?!
> It seems that the modified paket with source address replacement is in
> improper format?!! maybe the checksum?
> The system "crashed" everytime, if a paket comes from 192.168.0.123
> and entered the rule from iptables!?! If I set a rule e.g. "iptables
> -t raw -I PREROUTING -s 192.168.0.123 -j DROP" - it works fine!
>
> klogd says:
> <3>compat_xtables: compat layer limits reached
> (xtnu_skb_make_writable) - dropping packets
>
> one time I get this immediately before the crash:
> # iptables -nvL -t raw
> Chain PREROUTING (policy ACCEPT 16562 packets, 13M bytes)
> pkts bytes target prot opt in out source
> destination
> 15 1461 DROP all -- eth2 * 0.0.0.0/0
> 224.0.0.251
> 0 0 RAWSNAT all -- eth2 * 192.168.0.123
> 0.0.0.0/0 to-source 10.0.17.2/32
>
> Chain OUTPUT (policy ACCEPT 10293 packets, 1584K bytes)
> pkts bytes target prot opt in out source
> destination
> # iptables -nvL -t raw
> Chain PREROUTING (policy ACCEPT 16575 packets, 13M bytes)
> pkts bytes target prot opt in out source
> destination
> Segmentation fault
>
> happens when (tcpdump-trace): passierte bei:
>
> 13:41:39.810642 0:14:b:30:d0:2 0:30:18:49:f3:2a 0800 86:
> 192.168.0.123.1025 > 192.168.0.1.53: [udp sum ok] 51493+ PTR?
> 123.0.168.192.in-addr.arpa. (44) (ttl 255, id 7738, len 72)
> 0x0000 4500 0048 1e3a 0000 ff11 1b9e c0a8 007b E..H.:.........{
> 0x0010 c0a8 0001 0401 0035 0034 efaf c925 0100 .......5.4...%..
> 0x0020 0001 0000 0000 0000 0331 3233 0130 0331 .........123.0.1
> 0x0030 3638 0331 3932 0769 6e2d 6164 6472 0461 68.192.in-addr.a
> 0x0040 7270 6100 000c 0001 rpa.....
>
>
> Any help would be so much appreciated!
> Thank you very much in advance!
>
> Regards,
> Manu
>
>
>
>
>
> --
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>
[-- Attachment #2: arp.c --]
[-- Type: text/x-csrc, Size: 35811 bytes --]
/* linux/net/ipv4/arp.c
*
* Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem 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.
* Arnaldo C. Melo : convert /proc/net/arp to seq_file
* Shmulik Hen: Split arp_send to arp_create and
* arp_xmit so intermediate drivers like
* bonding can change the skb before
* sending (e.g. insert 8021q tag).
* Harald Welte : convert to make use of jenkins hash
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/capability.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/inetdevice.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/seq_file.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/net.h>
#include <linux/rcupdate.h>
#include <linux/jhash.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
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
#include <net/atmclip.h>
struct neigh_table *clip_tbl_hook;
#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,
.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,
.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(__be32 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;
case ARPHRD_INFINIBAND:
ip_ib_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)
{
return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd);
}
static int arp_constructor(struct neighbour *neigh)
{
__be32 addr = *(__be32*)neigh->primary_key;
struct net_device *dev = neigh->dev;
struct in_device *in_dev;
struct neigh_parms *parms;
neigh->type = inet_addr_type(addr);
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (in_dev == NULL) {
rcu_read_unlock();
return -EINVAL;
}
parms = in_dev->arp_parms;
__neigh_parms_put(neigh->parms);
neigh->parms = neigh_parms_clone(parms);
rcu_read_unlock();
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.
*/
#if 1
/* 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
;}
#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)
{
__be32 saddr = 0;
u8 *dst_ha = NULL;
struct net_device *dev = neigh->dev;
__be32 target = *(__be32*)neigh->primary_key;
int probes = atomic_read(&neigh->probes);
// struct in_device *in_dev = in_dev_get(dev);
// if (!in_dev)
// return;
// switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
// default:
// case 0: /* By default announce any local IP */
// if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
// saddr = ip_hdr(skb)->saddr;
// break;
// case 1: /* Restrict announcements of saddr in same subnet */
// if (!skb)
// break;
// saddr = ip_hdr(skb)->saddr;
// if (inet_addr_type(saddr) == RTN_LOCAL) {
// /* saddr should be known to target */
// if (inet_addr_onlink(in_dev, target, saddr))
// break;
// }
// saddr = 0;
// break;
// case 2: /* Avoid secondary IPs, get a primary/preferred one */
// break;
// }
// if (in_dev)
// in_dev_put(in_dev);
// if (!saddr)
// saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
/* added by scheub */
if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
saddr = ip_hdr(skb)->saddr;
else
saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
/* end added by scheub*/
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_ignore(struct in_device *in_dev, struct net_device *dev,
// __be32 sip, __be32 tip)
//{
// int scope;
// switch (IN_DEV_ARP_IGNORE(in_dev)) {
// case 0: /* Reply, the tip is already validated */
// return 0;
// case 1: /* Reply only if tip is configured on the incoming interface */
// sip = 0;
// scope = RT_SCOPE_HOST;
// break;
// case 2: /*
// * Reply only if tip is configured on the incoming interface
// * and is in same subnet as sip
// */
// scope = RT_SCOPE_HOST;
// break;
// case 3: /* Do not reply for scope host addresses */
// sip = 0;
// scope = RT_SCOPE_LINK;
// dev = NULL;
// break;
// case 4: /* Reserved */
// case 5:
// case 6:
// case 7:
// return 0;
// case 8: /* Do not reply */
// return 1;
// default:
// return 0;
// }
// return !inet_confirm_addr(dev, sip, tip, scope);
//}
static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
.saddr = tip } } };
struct rtable *rt;
int flag = 0;
/*unsigned long now; */
if (ip_route_output_key(&rt, &fl) < 0)
return 1;
if (rt->u.dst.dev != dev) {
NET_INC_STATS_BH(LINUX_MIB_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, __be32 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;
__be32 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) {
__be32 nexthop = ((struct rtable*)dst)->rt_gateway;
if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
nexthop = 0;
n = __neigh_lookup_errno(
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
dev->type == ARPHRD_ATM ? clip_tbl_hook :
#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 an arp packet. If (dest_hw == NULL), we create a broadcast
* message.
*/
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 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;
/*
* Allocate a buffer
*/
skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
+ LL_RESERVED_SPACE(dev), GFP_ATOMIC);
if (skb == NULL)
return NULL;
skb_reserve(skb, LL_RESERVED_SPACE(dev));
skb_reset_network_header(skb);
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);
return skb;
out:
kfree_skb(skb);
return NULL;
}
/*
* Send an arp packet.
*/
void arp_xmit(struct sk_buff *skb)
{
/* Send it off, maybe filter it using firewalling first. */
NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
}
/*
* Create and send an arp packet.
*/
void arp_send(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 src_ip,
unsigned char *dest_hw, unsigned char *src_hw,
unsigned char *target_hw)
{
struct sk_buff *skb;
/*
* No arp on this interface.
*/
if (dev->flags&IFF_NOARP)
return;
skb = arp_create(type, ptype, dest_ip, dev, src_ip,
dest_hw, src_hw, target_hw);
if (skb == NULL) {
return;
}
arp_xmit(skb);
}
/*
* Process an arp request.
*/
static 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;
__be32 sip, tip;
u16 dev_type = dev->type;
int addr_type;
struct neighbour *n;
/* arp_rcv below verifies the ARP header and verifies the device
* is ARP'able.
*/
if (in_dev == NULL)
goto out;
arp = arp_hdr(skb);
switch (dev_type) {
default:
if (arp->ar_pro != htons(ETH_P_IP) ||
htons(dev_type) != arp->ar_hrd)
goto out;
break;
#ifdef CONFIG_NET_ETHERNET
case ARPHRD_ETHER:
#endif
#ifdef CONFIG_TR
case ARPHRD_IEEE802_TR:
#endif
#ifdef CONFIG_FDDI
case ARPHRD_FDDI:
#endif
#ifdef CONFIG_NET_FC
case ARPHRD_IEEE802:
#endif
#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
/*
* ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
* devices, according to RFC 2625) devices will accept ARP
* hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
* This is the case also of FDDI, where the RFC 1390 says that
* FDDI devices should accept ARP hardware of (1) Ethernet,
* however, to be more robust, we'll accept both 1 (Ethernet)
* or 6 (IEEE 802.2)
*/
if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
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) ||
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) ||
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
*/
arp_ptr= (unsigned char *)(arp+1);
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_ignore(in_dev,dev,sip,tip))
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 (!dont_send)
// dont_send |= arp_ignore(in_dev,dev,sip,tip);
if (!dont_send && 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 (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
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);
if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) {
/* 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);
}
if (n) {
int state = NUD_REACHABLE;
int override;
/* 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.
*/
override = time_after(jiffies, n->updated + n->parms->locktime);
/* 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 ? NEIGH_UPDATE_F_OVERRIDE : 0);
neigh_release(n);
}
out:
if (in_dev)
in_dev_put(in_dev);
kfree_skb(skb);
return 0;
}
static void parp_redo(struct sk_buff *skb)
{
arp_process(skb);
}
/*
* Receive an arp request from the device layer.
*/
static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct arphdr *arp;
/* ARP header, plus 2 device addresses, plus 2 IP addresses. */
if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
(2 * dev->addr_len) +
(2 * sizeof(u32)))))
goto freeskb;
arp = arp_hdr(skb);
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;
memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
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)
*/
/*
* Set (create) an ARP cache entry.
*/
static int arp_req_set(struct arpreq *r, struct net_device * dev)
{
__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
struct neighbour *neigh;
int err;
if (r->arp_flags&ATF_PUBL) {
__be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
if (mask && mask != htonl(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_ALL(PROXY_ARP) = 1;
return 0;
}
if (__in_dev_get_rtnl(dev)) {
IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1);
return 0;
}
return -ENXIO;
}
if (r->arp_flags & ATF_PERM)
r->arp_flags |= ATF_COM;
if (dev == NULL) {
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
.tos = RTO_ONLINK } } };
struct rtable * rt;
if ((err = ip_route_output_key(&rt, &fl)) != 0)
return err;
dev = rt->u.dst.dev;
ip_rt_put(rt);
if (!dev)
return -EINVAL;
}
switch (dev->type) {
#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 (r->arp_ha.sa_family != ARPHRD_FDDI &&
r->arp_ha.sa_family != ARPHRD_ETHER &&
r->arp_ha.sa_family != ARPHRD_IEEE802)
return -EINVAL;
break;
#endif
default:
if (r->arp_ha.sa_family != dev->type)
return -EINVAL;
break;
}
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,
NEIGH_UPDATE_F_OVERRIDE|
NEIGH_UPDATE_F_ADMIN);
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)
{
__be32 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;
strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
neigh_release(neigh);
err = 0;
}
return err;
}
static int arp_req_delete(struct arpreq *r, struct net_device * dev)
{
int err;
__be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
struct neighbour *neigh;
if (r->arp_flags & ATF_PUBL) {
__be32 mask =
((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
if (mask == htonl(0xFFFFFFFF))
return pneigh_delete(&arp_tbl, &ip, dev);
if (mask == 0) {
if (dev == NULL) {
IPV4_DEVCONF_ALL(PROXY_ARP) = 0;
return 0;
}
if (__in_dev_get_rtnl(dev)) {
IN_DEV_CONF_SET(__in_dev_get_rtnl(dev),
PROXY_ARP, 0);
return 0;
}
return -ENXIO;
}
return -EINVAL;
}
if (dev == NULL) {
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
.tos = RTO_ONLINK } } };
struct rtable * rt;
if ((err = ip_route_output_key(&rt, &fl)) != 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,
NEIGH_UPDATE_F_OVERRIDE|
NEIGH_UPDATE_F_ADMIN);
neigh_release(neigh);
}
return err;
}
/*
* Handle an ARP layer I/O control request.
*/
int arp_ioctl(unsigned int cmd, void __user *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;
}
static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
switch (event) {
case NETDEV_CHANGEADDR:
neigh_changeaddr(&arp_tbl, dev);
rt_cache_flush(0);
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block arp_netdev_notifier = {
.notifier_call = arp_netdev_event,
};
/* 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,
};
static int arp_proc_init(void);
void __init arp_init(void)
{
neigh_table_init(&arp_tbl);
dev_add_pack(&arp_packet_type);
arp_proc_init();
#ifdef CONFIG_SYSCTL
neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
NET_IPV4_NEIGH, "ipv4", NULL, NULL);
#endif
register_netdevice_notifier(&arp_netdev_notifier);
}
#ifdef CONFIG_PROC_FS
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
/* ------------------------------------------------------------------------ */
/*
* ax25 -> ASCII conversion
*/
static 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 /* CONFIG_AX25 */
#define HBUFFERLEN 30
static void arp_format_neigh_entry(struct seq_file *seq,
struct neighbour *n)
{
char hbuffer[HBUFFERLEN];
const char hexbuf[] = "0123456789ABCDEF";
int k, j;
char tbuf[16];
struct net_device *dev = n->dev;
int hatype = dev->type;
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
sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
read_unlock(&n->lock);
}
static void arp_format_pneigh_entry(struct seq_file *seq,
struct pneigh_entry *n)
{
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));
seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
dev ? dev->name : "*");
}
static int arp_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN) {
seq_puts(seq, "IP address HW type Flags "
"HW address Mask Device\n");
} else {
struct neigh_seq_state *state = seq->private;
if (state->flags & NEIGH_SEQ_IS_PNEIGH)
arp_format_pneigh_entry(seq, v);
else
arp_format_neigh_entry(seq, v);
}
return 0;
}
static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
{
/* Don't want to confuse "arp -a" w/ magic entries,
* so we tell the generic iterator to skip NUD_NOARP.
*/
return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
}
/* ------------------------------------------------------------------------ */
static const struct seq_operations arp_seq_ops = {
.start = arp_seq_start,
.next = neigh_seq_next,
.stop = neigh_seq_stop,
.show = arp_seq_show,
};
static int arp_seq_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
int rc = -ENOMEM;
struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s)
goto out;
rc = seq_open(file, &arp_seq_ops);
if (rc)
goto out_kfree;
seq = file->private_data;
seq->private = s;
out:
return rc;
out_kfree:
kfree(s);
goto out;
}
static const struct file_operations arp_seq_fops = {
.owner = THIS_MODULE,
.open = arp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
static int __init arp_proc_init(void)
{
if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops))
return -ENOMEM;
return 0;
}
#else /* CONFIG_PROC_FS */
static int __init arp_proc_init(void)
{
return 0;
}
#endif /* CONFIG_PROC_FS */
EXPORT_SYMBOL(arp_broken_ops);
EXPORT_SYMBOL(arp_find);
EXPORT_SYMBOL(arp_create);
EXPORT_SYMBOL(arp_xmit);
EXPORT_SYMBOL(arp_send);
EXPORT_SYMBOL(arp_tbl);
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
EXPORT_SYMBOL(clip_tbl_hook);
#endif
[-- Attachment #3: arp.c.orig --]
[-- Type: text/plain, Size: 35379 bytes --]
/* linux/net/ipv4/arp.c
*
* Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem 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.
* Arnaldo C. Melo : convert /proc/net/arp to seq_file
* Shmulik Hen: Split arp_send to arp_create and
* arp_xmit so intermediate drivers like
* bonding can change the skb before
* sending (e.g. insert 8021q tag).
* Harald Welte : convert to make use of jenkins hash
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/capability.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/inetdevice.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/seq_file.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/net.h>
#include <linux/rcupdate.h>
#include <linux/jhash.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
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
#include <net/atmclip.h>
struct neigh_table *clip_tbl_hook;
#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,
.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,
.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(__be32 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;
case ARPHRD_INFINIBAND:
ip_ib_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)
{
return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd);
}
static int arp_constructor(struct neighbour *neigh)
{
__be32 addr = *(__be32*)neigh->primary_key;
struct net_device *dev = neigh->dev;
struct in_device *in_dev;
struct neigh_parms *parms;
neigh->type = inet_addr_type(addr);
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (in_dev == NULL) {
rcu_read_unlock();
return -EINVAL;
}
parms = in_dev->arp_parms;
__neigh_parms_put(neigh->parms);
neigh->parms = neigh_parms_clone(parms);
rcu_read_unlock();
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.
*/
#if 1
/* 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
;}
#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)
{
__be32 saddr = 0;
u8 *dst_ha = NULL;
struct net_device *dev = neigh->dev;
__be32 target = *(__be32*)neigh->primary_key;
int probes = atomic_read(&neigh->probes);
struct in_device *in_dev = in_dev_get(dev);
if (!in_dev)
return;
switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
default:
case 0: /* By default announce any local IP */
if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
saddr = ip_hdr(skb)->saddr;
break;
case 1: /* Restrict announcements of saddr in same subnet */
if (!skb)
break;
saddr = ip_hdr(skb)->saddr;
if (inet_addr_type(saddr) == RTN_LOCAL) {
/* saddr should be known to target */
if (inet_addr_onlink(in_dev, target, saddr))
break;
}
saddr = 0;
break;
case 2: /* Avoid secondary IPs, get a primary/preferred one */
break;
}
if (in_dev)
in_dev_put(in_dev);
if (!saddr)
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_ignore(struct in_device *in_dev, struct net_device *dev,
__be32 sip, __be32 tip)
{
int scope;
switch (IN_DEV_ARP_IGNORE(in_dev)) {
case 0: /* Reply, the tip is already validated */
return 0;
case 1: /* Reply only if tip is configured on the incoming interface */
sip = 0;
scope = RT_SCOPE_HOST;
break;
case 2: /*
* Reply only if tip is configured on the incoming interface
* and is in same subnet as sip
*/
scope = RT_SCOPE_HOST;
break;
case 3: /* Do not reply for scope host addresses */
sip = 0;
scope = RT_SCOPE_LINK;
dev = NULL;
break;
case 4: /* Reserved */
case 5:
case 6:
case 7:
return 0;
case 8: /* Do not reply */
return 1;
default:
return 0;
}
return !inet_confirm_addr(dev, sip, tip, scope);
}
static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
{
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
.saddr = tip } } };
struct rtable *rt;
int flag = 0;
/*unsigned long now; */
if (ip_route_output_key(&rt, &fl) < 0)
return 1;
if (rt->u.dst.dev != dev) {
NET_INC_STATS_BH(LINUX_MIB_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, __be32 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;
__be32 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) {
__be32 nexthop = ((struct rtable*)dst)->rt_gateway;
if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
nexthop = 0;
n = __neigh_lookup_errno(
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
dev->type == ARPHRD_ATM ? clip_tbl_hook :
#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 an arp packet. If (dest_hw == NULL), we create a broadcast
* message.
*/
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 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;
/*
* Allocate a buffer
*/
skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
+ LL_RESERVED_SPACE(dev), GFP_ATOMIC);
if (skb == NULL)
return NULL;
skb_reserve(skb, LL_RESERVED_SPACE(dev));
skb_reset_network_header(skb);
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);
return skb;
out:
kfree_skb(skb);
return NULL;
}
/*
* Send an arp packet.
*/
void arp_xmit(struct sk_buff *skb)
{
/* Send it off, maybe filter it using firewalling first. */
NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
}
/*
* Create and send an arp packet.
*/
void arp_send(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 src_ip,
unsigned char *dest_hw, unsigned char *src_hw,
unsigned char *target_hw)
{
struct sk_buff *skb;
/*
* No arp on this interface.
*/
if (dev->flags&IFF_NOARP)
return;
skb = arp_create(type, ptype, dest_ip, dev, src_ip,
dest_hw, src_hw, target_hw);
if (skb == NULL) {
return;
}
arp_xmit(skb);
}
/*
* Process an arp request.
*/
static 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;
__be32 sip, tip;
u16 dev_type = dev->type;
int addr_type;
struct neighbour *n;
/* arp_rcv below verifies the ARP header and verifies the device
* is ARP'able.
*/
if (in_dev == NULL)
goto out;
arp = arp_hdr(skb);
switch (dev_type) {
default:
if (arp->ar_pro != htons(ETH_P_IP) ||
htons(dev_type) != arp->ar_hrd)
goto out;
break;
#ifdef CONFIG_NET_ETHERNET
case ARPHRD_ETHER:
#endif
#ifdef CONFIG_TR
case ARPHRD_IEEE802_TR:
#endif
#ifdef CONFIG_FDDI
case ARPHRD_FDDI:
#endif
#ifdef CONFIG_NET_FC
case ARPHRD_IEEE802:
#endif
#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
/*
* ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
* devices, according to RFC 2625) devices will accept ARP
* hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
* This is the case also of FDDI, where the RFC 1390 says that
* FDDI devices should accept ARP hardware of (1) Ethernet,
* however, to be more robust, we'll accept both 1 (Ethernet)
* or 6 (IEEE 802.2)
*/
if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
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) ||
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) ||
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
*/
arp_ptr= (unsigned char *)(arp+1);
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_ignore(in_dev,dev,sip,tip))
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 (!dont_send)
dont_send |= arp_ignore(in_dev,dev,sip,tip);
if (!dont_send && 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 (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
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);
if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) {
/* 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);
}
if (n) {
int state = NUD_REACHABLE;
int override;
/* 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.
*/
override = time_after(jiffies, n->updated + n->parms->locktime);
/* 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 ? NEIGH_UPDATE_F_OVERRIDE : 0);
neigh_release(n);
}
out:
if (in_dev)
in_dev_put(in_dev);
kfree_skb(skb);
return 0;
}
static void parp_redo(struct sk_buff *skb)
{
arp_process(skb);
}
/*
* Receive an arp request from the device layer.
*/
static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct arphdr *arp;
/* ARP header, plus 2 device addresses, plus 2 IP addresses. */
if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
(2 * dev->addr_len) +
(2 * sizeof(u32)))))
goto freeskb;
arp = arp_hdr(skb);
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;
memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
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)
*/
/*
* Set (create) an ARP cache entry.
*/
static int arp_req_set(struct arpreq *r, struct net_device * dev)
{
__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
struct neighbour *neigh;
int err;
if (r->arp_flags&ATF_PUBL) {
__be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
if (mask && mask != htonl(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_ALL(PROXY_ARP) = 1;
return 0;
}
if (__in_dev_get_rtnl(dev)) {
IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1);
return 0;
}
return -ENXIO;
}
if (r->arp_flags & ATF_PERM)
r->arp_flags |= ATF_COM;
if (dev == NULL) {
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
.tos = RTO_ONLINK } } };
struct rtable * rt;
if ((err = ip_route_output_key(&rt, &fl)) != 0)
return err;
dev = rt->u.dst.dev;
ip_rt_put(rt);
if (!dev)
return -EINVAL;
}
switch (dev->type) {
#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 (r->arp_ha.sa_family != ARPHRD_FDDI &&
r->arp_ha.sa_family != ARPHRD_ETHER &&
r->arp_ha.sa_family != ARPHRD_IEEE802)
return -EINVAL;
break;
#endif
default:
if (r->arp_ha.sa_family != dev->type)
return -EINVAL;
break;
}
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,
NEIGH_UPDATE_F_OVERRIDE|
NEIGH_UPDATE_F_ADMIN);
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)
{
__be32 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;
strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
neigh_release(neigh);
err = 0;
}
return err;
}
static int arp_req_delete(struct arpreq *r, struct net_device * dev)
{
int err;
__be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
struct neighbour *neigh;
if (r->arp_flags & ATF_PUBL) {
__be32 mask =
((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
if (mask == htonl(0xFFFFFFFF))
return pneigh_delete(&arp_tbl, &ip, dev);
if (mask == 0) {
if (dev == NULL) {
IPV4_DEVCONF_ALL(PROXY_ARP) = 0;
return 0;
}
if (__in_dev_get_rtnl(dev)) {
IN_DEV_CONF_SET(__in_dev_get_rtnl(dev),
PROXY_ARP, 0);
return 0;
}
return -ENXIO;
}
return -EINVAL;
}
if (dev == NULL) {
struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
.tos = RTO_ONLINK } } };
struct rtable * rt;
if ((err = ip_route_output_key(&rt, &fl)) != 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,
NEIGH_UPDATE_F_OVERRIDE|
NEIGH_UPDATE_F_ADMIN);
neigh_release(neigh);
}
return err;
}
/*
* Handle an ARP layer I/O control request.
*/
int arp_ioctl(unsigned int cmd, void __user *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;
}
static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
switch (event) {
case NETDEV_CHANGEADDR:
neigh_changeaddr(&arp_tbl, dev);
rt_cache_flush(0);
break;
default:
break;
}
return NOTIFY_DONE;
}
static struct notifier_block arp_netdev_notifier = {
.notifier_call = arp_netdev_event,
};
/* 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,
};
static int arp_proc_init(void);
void __init arp_init(void)
{
neigh_table_init(&arp_tbl);
dev_add_pack(&arp_packet_type);
arp_proc_init();
#ifdef CONFIG_SYSCTL
neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
NET_IPV4_NEIGH, "ipv4", NULL, NULL);
#endif
register_netdevice_notifier(&arp_netdev_notifier);
}
#ifdef CONFIG_PROC_FS
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
/* ------------------------------------------------------------------------ */
/*
* ax25 -> ASCII conversion
*/
static 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 /* CONFIG_AX25 */
#define HBUFFERLEN 30
static void arp_format_neigh_entry(struct seq_file *seq,
struct neighbour *n)
{
char hbuffer[HBUFFERLEN];
const char hexbuf[] = "0123456789ABCDEF";
int k, j;
char tbuf[16];
struct net_device *dev = n->dev;
int hatype = dev->type;
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
sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
read_unlock(&n->lock);
}
static void arp_format_pneigh_entry(struct seq_file *seq,
struct pneigh_entry *n)
{
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));
seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
dev ? dev->name : "*");
}
static int arp_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN) {
seq_puts(seq, "IP address HW type Flags "
"HW address Mask Device\n");
} else {
struct neigh_seq_state *state = seq->private;
if (state->flags & NEIGH_SEQ_IS_PNEIGH)
arp_format_pneigh_entry(seq, v);
else
arp_format_neigh_entry(seq, v);
}
return 0;
}
static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
{
/* Don't want to confuse "arp -a" w/ magic entries,
* so we tell the generic iterator to skip NUD_NOARP.
*/
return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
}
/* ------------------------------------------------------------------------ */
static const struct seq_operations arp_seq_ops = {
.start = arp_seq_start,
.next = neigh_seq_next,
.stop = neigh_seq_stop,
.show = arp_seq_show,
};
static int arp_seq_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
int rc = -ENOMEM;
struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s)
goto out;
rc = seq_open(file, &arp_seq_ops);
if (rc)
goto out_kfree;
seq = file->private_data;
seq->private = s;
out:
return rc;
out_kfree:
kfree(s);
goto out;
}
static const struct file_operations arp_seq_fops = {
.owner = THIS_MODULE,
.open = arp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
static int __init arp_proc_init(void)
{
if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops))
return -ENOMEM;
return 0;
}
#else /* CONFIG_PROC_FS */
static int __init arp_proc_init(void)
{
return 0;
}
#endif /* CONFIG_PROC_FS */
EXPORT_SYMBOL(arp_broken_ops);
EXPORT_SYMBOL(arp_find);
EXPORT_SYMBOL(arp_create);
EXPORT_SYMBOL(arp_xmit);
EXPORT_SYMBOL(arp_send);
EXPORT_SYMBOL(arp_tbl);
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
EXPORT_SYMBOL(clip_tbl_hook);
#endif
[-- Attachment #4: arpt_mangle.c --]
[-- Type: text/x-csrc, Size: 3242 bytes --]
/* module that allows mangling of the arp payload */
#include <linux/module.h>
#include <linux/netfilter_arp/arpt_mangle.h>
#include <net/sock.h>
#include <net/arp.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
MODULE_DESCRIPTION("arptables arp payload mangle target");
static unsigned int
target(struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
unsigned int hooknum, const struct xt_target *target,
const void *targinfo)
{
const struct arpt_mangle *mangle = targinfo;
struct arphdr *arp;
unsigned char *arpptr;
int pln, hln;
__be32 sip, tip;
unsigned char sha[ETH_ALEN];
unsigned char tha[ETH_ALEN];
if (skb_shared(*pskb) || skb_cloned(*pskb)) {
struct sk_buff *nskb;
nskb = skb_copy(*pskb, GFP_ATOMIC);
if (!nskb)
return NF_DROP;
if ((*pskb)->sk)
skb_set_owner_w(nskb, (*pskb)->sk);
kfree_skb(*pskb);
*pskb = nskb;
}
arp = arp_hdr(*pskb);
arpptr = skb_network_header(*pskb) + sizeof(*arp);
pln = arp->ar_pln;
hln = arp->ar_hln;
/* We assume that pln and hln were checked in the match */
memcpy(sha, arpptr, hln);
if (mangle->flags & ARPT_MANGLE_SDEV) {
if (ARPT_DEV_ADDR_LEN_MAX < hln ||
(arpptr + hln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, mangle->src_devaddr, hln);
}
arpptr += hln;
memcpy(&sip, arpptr, pln);
if (mangle->flags & ARPT_MANGLE_SIP) {
if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
(arpptr + pln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, &mangle->u_s.src_ip, pln);
}
arpptr += pln;
memcpy(tha, arpptr, hln);
if (mangle->flags & ARPT_MANGLE_TDEV) {
if (ARPT_DEV_ADDR_LEN_MAX < hln ||
(arpptr + hln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, mangle->tgt_devaddr, hln);
}
arpptr += hln;
memcpy(&tip, arpptr, pln);
if (mangle->flags & ARPT_MANGLE_TIP) {
if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
(arpptr + pln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, &mangle->u_t.tgt_ip, pln);
}
if ((mangle->flags & ARPT_MANGLE_AUTO) && (arp->ar_op == __constant_htons(ARPOP_REQUEST)) &&
(sip != tip)) {
arp_send( ARPOP_REPLY, ETH_P_ARP,sip,(struct net_device *)in,
tip,sha,(unsigned char *) mangle->tgt_devaddr,sha);
}
return mangle->target;
}
static bool
checkentry(const char *tablename, const void *e, const struct xt_target *target,
void *targinfo, unsigned int hook_mask)
{
const struct arpt_mangle *mangle = targinfo;
if (mangle->flags & ~ARPT_MANGLE_MASK ||
!(mangle->flags & ARPT_MANGLE_MASK))
return false;
if (mangle->target != NF_DROP && mangle->target != NF_ACCEPT &&
mangle->target != ARPT_CONTINUE)
return false;
return true;
}
static struct arpt_target arpt_mangle_reg __read_mostly = {
.name = "mangle",
.target = target,
.targetsize = sizeof(struct arpt_mangle),
.checkentry = checkentry,
.me = THIS_MODULE,
};
static int __init arpt_mangle_init(void)
{
if (arpt_register_target(&arpt_mangle_reg))
return -EINVAL;
return 0;
}
static void __exit arpt_mangle_fini(void)
{
arpt_unregister_target(&arpt_mangle_reg);
}
module_init(arpt_mangle_init);
module_exit(arpt_mangle_fini);
[-- Attachment #5: arpt_mangle.c.orig --]
[-- Type: text/plain, Size: 2750 bytes --]
/* module that allows mangling of the arp payload */
#include <linux/module.h>
#include <linux/netfilter_arp/arpt_mangle.h>
#include <net/sock.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
MODULE_DESCRIPTION("arptables arp payload mangle target");
static unsigned int
target(struct sk_buff **pskb,
const struct net_device *in, const struct net_device *out,
unsigned int hooknum, const struct xt_target *target,
const void *targinfo)
{
const struct arpt_mangle *mangle = targinfo;
struct arphdr *arp;
unsigned char *arpptr;
int pln, hln;
if (skb_shared(*pskb) || skb_cloned(*pskb)) {
struct sk_buff *nskb;
nskb = skb_copy(*pskb, GFP_ATOMIC);
if (!nskb)
return NF_DROP;
if ((*pskb)->sk)
skb_set_owner_w(nskb, (*pskb)->sk);
kfree_skb(*pskb);
*pskb = nskb;
}
arp = arp_hdr(*pskb);
arpptr = skb_network_header(*pskb) + sizeof(*arp);
pln = arp->ar_pln;
hln = arp->ar_hln;
/* We assume that pln and hln were checked in the match */
if (mangle->flags & ARPT_MANGLE_SDEV) {
if (ARPT_DEV_ADDR_LEN_MAX < hln ||
(arpptr + hln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, mangle->src_devaddr, hln);
}
arpptr += hln;
if (mangle->flags & ARPT_MANGLE_SIP) {
if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
(arpptr + pln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, &mangle->u_s.src_ip, pln);
}
arpptr += pln;
if (mangle->flags & ARPT_MANGLE_TDEV) {
if (ARPT_DEV_ADDR_LEN_MAX < hln ||
(arpptr + hln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, mangle->tgt_devaddr, hln);
}
arpptr += hln;
if (mangle->flags & ARPT_MANGLE_TIP) {
if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
(arpptr + pln > skb_tail_pointer(*pskb)))
return NF_DROP;
memcpy(arpptr, &mangle->u_t.tgt_ip, pln);
}
return mangle->target;
}
static bool
checkentry(const char *tablename, const void *e, const struct xt_target *target,
void *targinfo, unsigned int hook_mask)
{
const struct arpt_mangle *mangle = targinfo;
if (mangle->flags & ~ARPT_MANGLE_MASK ||
!(mangle->flags & ARPT_MANGLE_MASK))
return false;
if (mangle->target != NF_DROP && mangle->target != NF_ACCEPT &&
mangle->target != ARPT_CONTINUE)
return false;
return true;
}
static struct arpt_target arpt_mangle_reg __read_mostly = {
.name = "mangle",
.target = target,
.targetsize = sizeof(struct arpt_mangle),
.checkentry = checkentry,
.me = THIS_MODULE,
};
static int __init arpt_mangle_init(void)
{
if (arpt_register_target(&arpt_mangle_reg))
return -EINVAL;
return 0;
}
static void __exit arpt_mangle_fini(void)
{
arpt_unregister_target(&arpt_mangle_reg);
}
module_init(arpt_mangle_init);
module_exit(arpt_mangle_fini);
[-- Attachment #6: arpt_mangle.h --]
[-- Type: text/x-chdr, Size: 577 bytes --]
#ifndef _ARPT_MANGLE_H
#define _ARPT_MANGLE_H
#include <linux/netfilter_arp/arp_tables.h>
#define ARPT_MANGLE_ADDR_LEN_MAX sizeof(struct in_addr)
struct arpt_mangle
{
char src_devaddr[ARPT_DEV_ADDR_LEN_MAX];
char tgt_devaddr[ARPT_DEV_ADDR_LEN_MAX];
union {
struct in_addr src_ip;
} u_s;
union {
struct in_addr tgt_ip;
} u_t;
u_int8_t flags;
int target;
};
#define ARPT_MANGLE_SDEV 0x01
#define ARPT_MANGLE_TDEV 0x02
#define ARPT_MANGLE_SIP 0x04
#define ARPT_MANGLE_TIP 0x08
#define ARPT_MANGLE_AUTO 0x10
#define ARPT_MANGLE_MASK 0x1f
#endif /* _ARPT_MANGLE_H */
[-- Attachment #7: arpt_mangle.h.orig --]
[-- Type: text/plain, Size: 547 bytes --]
#ifndef _ARPT_MANGLE_H
#define _ARPT_MANGLE_H
#include <linux/netfilter_arp/arp_tables.h>
#define ARPT_MANGLE_ADDR_LEN_MAX sizeof(struct in_addr)
struct arpt_mangle
{
char src_devaddr[ARPT_DEV_ADDR_LEN_MAX];
char tgt_devaddr[ARPT_DEV_ADDR_LEN_MAX];
union {
struct in_addr src_ip;
} u_s;
union {
struct in_addr tgt_ip;
} u_t;
u_int8_t flags;
int target;
};
#define ARPT_MANGLE_SDEV 0x01
#define ARPT_MANGLE_TDEV 0x02
#define ARPT_MANGLE_SIP 0x04
#define ARPT_MANGLE_TIP 0x08
#define ARPT_MANGLE_MASK 0x0f
#endif /* _ARPT_MANGLE_H */
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #8: xt_RAWNAT.c --]
[-- Type: text/x-csrc; name="xt_RAWNAT.c", Size: 6854 bytes --]
/*
* xt_RAWNAT - Netfilter module to do untracked NAT
*
* Copyright © CC Computer Consultants GmbH, 2008
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 or 3 as published by the Free Software Foundation.
*/
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/x_tables.h>
#include <net/tcp.h>
#include <net/netfilter/nf_conntrack.h>
#include "compat_xtables.h"
#include "xt_RAWNAT.h"
#if LINUX_VERSION_CODE != KERNEL_VERSION(2, 6, 23)
# warning Have not compile-tested this on anything else than 2.6.23 yet.
#endif
static inline void csum_repl4(__u16 *sum, __be32 from, __be32 to)
{
__be32 diff[] = {~from, to};
*sum = csum_fold(csum_partial((const char *)diff,
sizeof(diff), ~csum_unfold(*sum)));
}
static inline u_int32_t
remask(u_int32_t addr, u_int32_t repl, unsigned int shift)
{
u_int32_t mask = (shift == 32) ? 0 : (~(u_int32_t)0 >> shift);
return htonl((ntohl(addr) & ~mask) | ntohl(repl));
}
static void
rawnat_ipv6_mask(__be32 *addr, const __be32 *repl, unsigned int mask)
{
switch (mask) {
case 0:
break;
case 1 ... 31:
addr[0] = remask(addr[0], repl[0], mask);
break;
case 32:
addr[0] = repl[0];
break;
case 33 ... 63:
addr[0] = repl[0];
addr[1] = remask(addr[1], repl[1], mask - 64);
break;
case 64:
addr[0] = repl[0];
addr[1] = repl[1];
break;
case 65 ... 95:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = remask(addr[2], repl[2], mask - 96);
case 96:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
break;
case 97 ... 127:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
addr[3] = remask(addr[3], repl[3], mask - 128);
break;
case 128:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
addr[3] = repl[3];
break;
}
}
static void rawnat4_update_l4(const struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
struct tcphdr *tcph;
struct udphdr *udph;
unsigned int l4len;
switch (iph->protocol) {
case IPPROTO_TCP:
tcph = tcp_hdr(skb);
tcph->check = 0;
tcph->check = tcp_v4_check(sizeof(struct tcphdr), iph->saddr,
iph->daddr,
csum_partial(skb_transport_header(skb), sizeof(struct tcphdr), 0));
break;
case IPPROTO_UDP:
l4len = skb->len - ip_hdrlen(skb);
udph = udp_hdr(skb);
udph->check = 0;
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, l4len,
IPPROTO_UDP,
csum_partial(skb_transport_header(skb), l4len, 0));
break;
}
}
static unsigned int
rawsnat_tg4(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct iphdr *iph;
__be32 na;
//u_int32_t na;
iph = ip_hdr(skb);
//na = remask(iph->saddr, info->addr.ip, info->mask);
na = info->addr.ip;
if (iph->saddr == na)
return XT_CONTINUE;
if (!skb_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
// iph = ip_hdr(skb);
csum_repl4(&iph->check, iph->saddr, na);
iph->saddr = na;
// rawnat4_update_l4(skb);
return XT_CONTINUE;
}
static unsigned int
rawdnat_tg4(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct iphdr *iph;
__be32 new_addr;
//u_int32_t new_addr;
iph = ip_hdr(skb);
//new_addr = remask(iph->daddr, info->addr.ip, info->mask);
new_addr = info->addr.ip;
if (iph->daddr == new_addr)
return XT_CONTINUE;
if (!skb_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
iph = ip_hdr(skb);
csum_repl4(&iph->check, iph->daddr, new_addr);
iph->daddr = new_addr;
rawnat4_update_l4(skb);
return XT_CONTINUE;
}
static unsigned int
rawsnat_tg6(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct ipv6hdr *iph;
if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
return NF_DROP;
iph = ipv6_hdr(skb);
// rawnat_ipv6_mask(iph->saddr.s6_addr32, info->addr.ip6, info->mask);
return XT_CONTINUE;
}
static unsigned int
rawdnat_tg6(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct ipv6hdr *iph;
if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
return NF_DROP;
iph = ipv6_hdr(skb);
// rawnat_ipv6_mask(iph->daddr.s6_addr32, info->addr.ip6, info->mask);
return XT_CONTINUE;
}
static bool rawnat_tg_check(const char *table, const void *entry,
const struct xt_target *target, void *targinfo, unsigned int hook_mask)
{
if (strcmp(table, "raw") == 0 || strcmp(table, "rawpost") == 0)
return true;
printk(KERN_ERR KBUILD_MODNAME " may only be used in the \"raw\" or "
"\"rawpost\" table.\n");
return false;
}
static struct xt_target rawnat_tg_reg[] __read_mostly = {
{
.name = "RAWSNAT",
.revision = 0,
.family = PF_INET,
.target = rawsnat_tg4,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWSNAT",
.revision = 0,
.family = PF_INET6,
.target = rawsnat_tg6,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWDNAT",
.revision = 0,
.family = PF_INET,
.target = rawdnat_tg4,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWDNAT",
.revision = 0,
.family = PF_INET6,
.target = rawdnat_tg6,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
};
static int __init rawnat_tg_init(void)
{
return xt_register_targets(rawnat_tg_reg, ARRAY_SIZE(rawnat_tg_reg));
}
static void __exit rawnat_tg_exit(void)
{
xt_unregister_targets(rawnat_tg_reg, ARRAY_SIZE(rawnat_tg_reg));
}
module_init(rawnat_tg_init);
module_exit(rawnat_tg_exit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: conntrack-less raw NAT");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_RAWSNAT");
MODULE_ALIAS("ipt_RAWDNAT");
MODULE_ALIAS("ip6t_RAWSNAT");
MODULE_ALIAS("ip6t_RAWDNAT");
[-- Attachment #9: xt_RAWNAT.c.orig --]
[-- Type: text/plain, Size: 6650 bytes --]
/*
* xt_RAWNAT - Netfilter module to do untracked NAT
*
* Copyright © CC Computer Consultants GmbH, 2008
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 or 3 as published by the Free Software Foundation.
*/
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/x_tables.h>
#include <net/tcp.h>
#include <net/netfilter/nf_conntrack.h>
#include "compat_xtables.h"
#include "xt_RAWNAT.h"
#if LINUX_VERSION_CODE != KERNEL_VERSION(2, 6, 23)
# warning Have not compile-tested this on anything else than 2.6.23 yet.
#endif
static inline void csum_repl4(__u16 *sum, __be32 from, __be32 to)
{
__be32 diff[] = {~from, to};
*sum = csum_fold(csum_partial((const char *)diff,
sizeof(diff), ~csum_unfold(*sum)));
}
static inline u_int32_t
remask(u_int32_t addr, u_int32_t repl, unsigned int shift)
{
u_int32_t mask = (shift == 32) ? 0 : (~(u_int32_t)0 >> shift);
return htonl((ntohl(addr) & ~mask) | ntohl(repl));
}
static void
rawnat_ipv6_mask(__be32 *addr, const __be32 *repl, unsigned int mask)
{
switch (mask) {
case 0:
break;
case 1 ... 31:
addr[0] = remask(addr[0], repl[0], mask);
break;
case 32:
addr[0] = repl[0];
break;
case 33 ... 63:
addr[0] = repl[0];
addr[1] = remask(addr[1], repl[1], mask - 64);
break;
case 64:
addr[0] = repl[0];
addr[1] = repl[1];
break;
case 65 ... 95:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = remask(addr[2], repl[2], mask - 96);
case 96:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
break;
case 97 ... 127:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
addr[3] = remask(addr[3], repl[3], mask - 128);
break;
case 128:
addr[0] = repl[0];
addr[1] = repl[1];
addr[2] = repl[2];
addr[3] = repl[3];
break;
}
}
static void rawnat4_update_l4(const struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
struct tcphdr *tcph;
struct udphdr *udph;
unsigned int l4len;
switch (iph->protocol) {
case IPPROTO_TCP:
tcph = tcp_hdr(skb);
tcph->check = 0;
tcph->check = tcp_v4_check(sizeof(struct tcphdr), iph->saddr,
iph->daddr,
csum_partial(skb_transport_header(skb), sizeof(struct tcphdr), 0));
break;
case IPPROTO_UDP:
l4len = skb->len - ip_hdrlen(skb);
udph = udp_hdr(skb);
udph->check = 0;
udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr, l4len,
IPPROTO_UDP,
csum_partial(skb_transport_header(skb), l4len, 0));
break;
}
}
static unsigned int
rawsnat_tg4(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct iphdr *iph;
u_int32_t na;
if (!skb_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
iph = ip_hdr(skb);
na = remask(iph->saddr, info->addr.ip, info->mask);
csum_repl4(&iph->check, iph->saddr, na);
iph->saddr = na;
return XT_CONTINUE;
}
static unsigned int
rawdnat_tg4(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct iphdr *iph;
__be32 new_addr;
iph = ip_hdr(skb);
new_addr = remask(iph->daddr, info->addr.ip, info->mask);
if (iph->daddr == new_addr)
return XT_CONTINUE;
if (!skb_make_writable(skb, sizeof(struct iphdr)))
return NF_DROP;
iph = ip_hdr(skb);
csum_repl4(&iph->check, iph->daddr, new_addr);
iph->daddr = new_addr;
rawnat4_update_l4(skb);
return XT_CONTINUE;
}
static unsigned int
rawsnat_tg6(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct ipv6hdr *iph;
if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
return NF_DROP;
iph = ipv6_hdr(skb);
rawnat_ipv6_mask(iph->saddr.s6_addr32, info->addr.ip6, info->mask);
return XT_CONTINUE;
}
static unsigned int
rawdnat_tg6(struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target, const void *targinfo)
{
const struct xt_rawnat_tginfo *info = targinfo;
struct ipv6hdr *iph;
if (!skb_make_writable(skb, sizeof(struct ipv6hdr)))
return NF_DROP;
iph = ipv6_hdr(skb);
rawnat_ipv6_mask(iph->daddr.s6_addr32, info->addr.ip6, info->mask);
return XT_CONTINUE;
}
static bool rawnat_tg_check(const char *table, const void *entry,
const struct xt_target *target, void *targinfo, unsigned int hook_mask)
{
if (strcmp(table, "raw") == 0 || strcmp(table, "rawpost") == 0)
return true;
printk(KERN_ERR KBUILD_MODNAME " may only be used in the \"raw\" or "
"\"rawpost\" table.\n");
return false;
}
static struct xt_target rawnat_tg_reg[] __read_mostly = {
{
.name = "RAWSNAT",
.revision = 0,
.family = PF_INET,
.target = rawsnat_tg4,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWSNAT",
.revision = 0,
.family = PF_INET6,
.target = rawsnat_tg6,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWDNAT",
.revision = 0,
.family = PF_INET,
.target = rawdnat_tg4,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
{
.name = "RAWDNAT",
.revision = 0,
.family = PF_INET6,
.target = rawdnat_tg6,
.targetsize = sizeof(struct xt_rawnat_tginfo),
.checkentry = rawnat_tg_check,
.me = THIS_MODULE,
},
};
static int __init rawnat_tg_init(void)
{
return xt_register_targets(rawnat_tg_reg, ARRAY_SIZE(rawnat_tg_reg));
}
static void __exit rawnat_tg_exit(void)
{
xt_unregister_targets(rawnat_tg_reg, ARRAY_SIZE(rawnat_tg_reg));
}
module_init(rawnat_tg_init);
module_exit(rawnat_tg_exit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: conntrack-less raw NAT");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_RAWSNAT");
MODULE_ALIAS("ipt_RAWDNAT");
MODULE_ALIAS("ip6t_RAWSNAT");
MODULE_ALIAS("ip6t_RAWDNAT");
next prev parent reply other threads:[~2008-07-28 11:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-10 9:14 RAWNAT kernel crash Manu
2008-07-10 9:22 ` Jan Engelhardt
[not found] ` <4875DCD0.9070107@gmx.de>
2008-07-10 10:11 ` Jan Engelhardt
[not found] ` <4875EF77.8060700@gmx.de>
2008-07-10 11:23 ` Manu
2008-07-15 11:43 ` Manu
2008-07-16 16:21 ` Manu
2008-07-28 11:01 ` Manu
2008-07-28 11:44 ` Manu [this message]
2008-07-29 10:11 ` Manu
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