[2.6 PATCH] bugfix: ARP respond on all devices

[Bas Bloemsaat <bloemsaa@xxxxxxxxx>]

This is the samefix as the 2.4 patch. I do not have a machine on which I
can test 2.6, but visual examination of the files suggested the same
mechanism. In fact, I was surprised that the 2.4 patch wouldn't patch 2.6
so I made this one.

It was made with 2.6.0-test1, and compiles.

Can someone confirm that 2.6 has the same bug, and that this patch fixes
it? I suspect it has, and suspect this fixes it, but can't test for lack
of an available machine.

Regards,
Bas Bloemsaat

diff -urN linux-2.6.0-test1.orig/include/linux/inetdevice.h 
linux-2.6.0-test1/include/linux/inetdevice.h
--- linux-2.6.0-test1.orig/include/linux/inetdevice.h   2003-07-14 
05:35:56.000000000 +0200
+++ linux-2.6.0-test1/include/linux/inetdevice.h        2003-07-27 
21:33:02.000000000 +0200
@@ -98,6 +98,7 @@
 extern u32             inet_select_addr(const struct net_device *dev, u32 dst, 
int scope);
 extern struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, u32 
prefix, u32 mask);
 extern void            inet_forward_change(void);
+extern int             inet_addr_local_dev(struct in_device *in_dev, u32 addr);

 static __inline__ int inet_ifa_match(u32 addr, struct in_ifaddr *ifa)
 {
diff -urN linux-2.6.0-test1.orig/net/ipv4/arp.c linux-2.6.0-test1/net/ipv4/arp.c
--- linux-2.6.0-test1.orig/net/ipv4/arp.c       2003-07-14 05:37:28.000000000 
+0200
+++ linux-2.6.0-test1/net/ipv4/arp.c    2003-07-27 21:37:31.000000000 +0200
@@ -67,6 +67,7 @@
  *                                     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
+ *             Bas Bloemsaat   :       (20030727) Fixed respond on all devices 
bug
  */

 #include <linux/types.h>
@@ -750,7 +751,8 @@
                rt = (struct rtable*)skb->dst;
                addr_type = rt->rt_type;

-               if (addr_type == RTN_LOCAL) {
+               /* check if arp is for this device */
+               if (inet_addr_local_dev(in_dev,tip)) {
                        n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
                        if (n) {
                                int dont_send = 0;
@@ -762,6 +764,7 @@
                                neigh_release(n);
                        }
                        goto out;
+                /* check if we can and have to proxy it */
                } else if (IN_DEV_FORWARD(in_dev)) {
                        if ((rt->rt_flags&RTCF_DNAT) ||
                            (addr_type == RTN_UNICAST  && rt->u.dst.dev != dev 
&&
diff -urN linux-2.6.0-test1.orig/net/ipv4/devinet.c 
linux-2.6.0-test1/net/ipv4/devinet.c
--- linux-2.6.0-test1.orig/net/ipv4/devinet.c   2003-07-14 05:31:57.000000000 
+0200
+++ linux-2.6.0-test1/net/ipv4/devinet.c        2003-07-27 21:34:46.000000000 
+0200
@@ -219,6 +219,15 @@
        return 0;
 }

+int inet_addr_local_dev(struct in_device *in_dev, u32 addr)
+{
+       for_ifa(in_dev) {
+               if (!(addr^ifa->ifa_address))
+                       return -1;
+       } endfor_ifa(in_dev);
+       return 0;
+}
+
 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
                         int destroy)
 {