Here the local hexbuf is a duplicate of global const char hex_asc from
lib/hexdump.c, except the hex letters' cases:

	const char hexbuf[] = "0123456789ABCDEF";

	const char hex_asc[] = "0123456789abcdef";

and here to print HW addresses, the hex cases are not significant.

Thanks to Harvey Harrison to introduce the hex_asc_hi/hex_asc_lo helpers.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds needed_headroom/needed_tailroom members to struct
net_device and updates many places that allocate sbks to use them. Not
all of them can be converted though, and I'm sure I missed some (I
mostly grepped for LL_RESERVED_SPACE)

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

And use %u to format port.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Seqfile operation showing /proc/net/arp are already namespace
aware. All we need is to register this file for each namespace.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Get namespace from a device and pass it to the routing engine. Enable
ARP packet processing and device notifiers after that.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

(Anonymous) unions can help us to avoid ugly casts.

A common cast it the (struct rtable *)skb->dst one.

Defining an union like  :
union {
     struct dst_entry *dst;
     struct rtable *rtable;
};
permits to use skb->rtable in place.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are some place, that calculate the ARP header length. These
calculations are correct, but 
 a) some operate with "magic" constants,
 b) enlarge the code length (sometimes at the cost of coding style),
 c) are not informative from the first glance.

The proposal is to introduce a helper, that includes all the good
sides of these calculations.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 69cc64d8d92bf852f933e90c888dfff083bd4fc9.

It causes recursive locking in IPV6 because unlike other
neighbour layer clients, it even needs neighbour cache
entries to send neighbour soliciation messages :-(

We'll have to find another way to fix this race.

Signed-off-by: David S. Miller <davem@davemloft.net>

Frank Blaschka provided the bug report and the initial suggested fix
for this bug.  He also validated this version of this fix.

The problem is that the access to neigh->arp_queue is inconsistent, we
grab references when dropping the lock lock to call
neigh->ops->solicit() but this does not prevent other threads of
control from trying to send out that packet at the same time causing
corruptions because both code paths believe they have exclusive access
to the skb.

The best option seems to be to hold the write lock on neigh->lock
during the ->solicit() call.  I looked at all of the ndisc_ops
implementations and this seems workable.  The only case that needs
special care is the IPV4 ARP implementation of arp_solicit().  It
wants to take neigh->lock as a reader to protect the header entry in
neigh->ha during the emission of the soliciation.  We can simply
remove the read lock calls to take care of that since holding the lock
as a writer at the caller providers a superset of the protection
afforded by the existing read locking.

The rest of the ->solicit() implementations don't care whether the
neigh is locked or not.

Signed-off-by: David S. Miller <davem@davemloft.net>