in __neigh_event_send, if we have a neighbour entry which is in
NUD_INCOMPLETE state, we enqueue any outbound frames to that neighbour
to the neighbours arp_queue, which is default capped to a length of 3
skbs.  If that queue exceeds its set length, it will drop an skb on
the queue to enqueue the newly arrived skb.  This results in a drop
for which we have no statistics incremented.  This patch adds an
unresolved_discards stat to /proc/net/stat/ndisc_cache to track these
lost frames.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make nlmsg_trim(), nlmsg_cancel(), genlmsg_cancel(), and
nla_nest_cancel() void functions.

Return -EMSGSIZE instead of -1 if the provided message buffer is not
big enough.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neighbor table time of last use information is returned in the
incorrect unit. Kernel to user space ABI's need to use USER_HZ (or
milliseconds), otherwise the application has to try and discover the
real system HZ value which is problematic.  Linux has standardized on
keeping USER_HZ consistent (100hz) even when kernel is running
internally at some other value.

This change is small, but it breaks the ABI for older version of
iproute2 utilities.  But these utilities are already broken since they
are looking at the psched_hz values which are completely different. So
let's just go ahead and fix both kernel and user space. Older
utilities will just print wrong values.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simply replace proc_create and further data assigned with proc_create_data.
Additionally, there is no need to assign NULL to PDE->data after creation,
/proc generic has already done this for us.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extract hash function for pneigh entries from pneigh_lookup(),
__pneigh_lookup() and pneigh_delete() as pneigh_hash().
Extract core of pneigh_lookup() and __pneigh_lookup() as
__pneigh_lookup_1().
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

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

Introduce an inline net_eq() to compare two namespaces.
Without CONFIG_NET_NS, since no namespace other than &init_net
exists, it is always 1.

We do not need to convert 1) inline vs inline and
2) inline vs &init_net comparisons.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Introduce neigh_parms/pneigh_entry inlines: neigh_parms_net(), pneigh_net().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Without CONFIG_NET_NS, no namespace other than &init_net exists,
no need to store net in seq_net_private.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_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: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

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: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Proxy neighbors do not have any reference counting, so any caller
of pneigh_lookup (unless it's a netlink triggered add/del routine)
should _not_ perform any actions on the found proxy entry. 

There's one exception from this rule - the ipv6's ndisc_recv_ns() 
uses found entry to check the flags for NTF_ROUTER.

This creates a race between the ndisc and pneigh_delete - after 
the pneigh is returned to the caller, the nd_tbl.lock is dropped 
and the deleting procedure may proceed.

One of the fixes would be to add a reference counting, but this
problem exists for ndisc only. Besides such a patch would be too 
big for -rc4.

So I propose to introduce a __pneigh_lookup() which is supposed
to be called with the lock held and use it in ndisc code to check
the flags on alive pneigh entry.


Changes from v2:
As David noticed, Exported the __pneigh_lookup() to ipv6 module. 
The checkpatch generates a warning on it, since the EXPORT_SYMBOL 
does not follow the symbol itself, but in this file all the 
exports come at the end, so I decided no to break this harmony.

Changes from v1:
Fixed comments from YOSHIFUJI - indentation of prototype in header
and the pndisc_check_router() name - and a compilation fix, pointed
by Daniel - the is_routed was (falsely) considered as uninitialized
by gcc.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

neigh_update sends skb from neigh->arp_queue while neigh_timer_handler
has increased skbs refcount and calls solicit with the
skb. neigh_timer_handler should not increase skbs refcount but make a
copy of the skb and do solicit with the copy.
Signed-off-by: NFrank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Default ARP parameters should be findable regardless of the context.
Required to make inetdev_event working.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

neigh_sysctl_register should register sysctl entries inside correct namespace
to avoid naming conflict. Typical example is a loopback. Entries for it
present in all namespaces.

Required to make inetdev_event working.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use proc_create() to make sure that ->proc_fops be setup before gluing
PDE to main tree.
Signed-off-by: NWang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neigh_hash_grow() may update the tbl->hash_rnd value, which 
is used in all tbl->hash callbacks to calculate the hashval.

Two lookup routines may race with this, since they call the 
->hash callback without the tbl->lock held. Since the hash_rnd
is changed with this lock write-locked moving the calls to ->hash
under this lock read-locked closes this gap.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

release_net is missed on the error path in pneigh_lookup.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 69cc64d8.

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: NDavid 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: NDavid S. Miller <davem@davemloft.net>

Make them static.

[ Moved the inline before, instead of after, call sites. -DaveM ]
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No need for this. It is declared in the neighbour.h
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Valid network device is always passed into neigh_param_alloc, so
remove extra checking for dev == NULL. Additionally, cleanup bogus
netns assignment.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

seq_open_net requires that first field of the seq->private data to be
struct seq_net_private. In reality this is a single pointer to a
struct net for now. The patch makes code consistent.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add __acquires() and __releases() annotations to suppress some sparse
warnings.

example of warnings :

net/ipv4/udp.c:1555:14: warning: context imbalance in 'udp_seq_start' - wrong
count at exit
net/ipv4/udp.c:1571:13: warning: context imbalance in 'udp_seq_stop' -
unexpected unlock
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I'm actually surprised at how much was involved.  At first glance it
appears that the neighbour table data structures are already split by
network device so all that should be needed is to modify the user
interface commands to filter the set of neighbours by the network
namespace of their devices.

However a couple things turned up while I was reading through the
code.  The proxy neighbour table allows entries with no network
device, and the neighbour parms are per network device (except for the
defaults) so they now need a per network namespace default.

So I updated the two structures (which surprised me) with their very
own network namespace parameter.  Updated the relevant lookup and
destroy routines with a network namespace parameter and modified the
code that interacts with users to filter out neighbour table entries
for devices of other namespaces.

I'm a little concerned that we can modify and display the global table
configuration and from all network namespaces.  But this appears good
enough for now.

I keep thinking modifying the neighbour table to have per network
namespace instances of each table type would should be cleaner.  The
hash table is already dynamically sized so there are it is not a
limiter.  The default parameter would be straight forward to take care
of.  However when I look at the how the network table is built and
used I still find some assumptions that there is only a single
neighbour table for each type of table in the kernel.  The netlink
operations, neigh_seq_start, the non-core network users that call
neigh_lookup.  So while it might be doable it would require more
refactoring than my current approach of just doing a little extra
filtering in the code.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neigh_del_timer() looks sane - it removes the timer and
(conditionally) puts the neighbor. I expected, that the
neigh_add_timer() is symmetrical to the del one - i.e. it
holds the neighbor and arms the timer - but it turned out
that it was not so.

I think, that making them look symmetrical makes the code
more readable.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The appropriate path is prepared right inside this function. It
is prepared similar to how the ctl tables were.

Since the path is modified, it is put on the stack, to avoid
possible races with multiple calls to neigh_sysctl_register() : it
is called by protocols and I didn't find any protection in this
case. Did I overlooked the rtnl lock?.

The stack growth of the neigh_sysctl_register() is 40 bytes. I
believe this is OK, since this is not that much and this function
is not called with the deep stack (device/protocols register).

The device's name is stored on the template to free it later.

This will help with the net namespaces, as each namespace should
have its own set of these ctls.

Besides, this saves ~350 bytes from the neigh template :)
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This mainly removes the err variable, as this call always
return the same error code (-ENOBUFS).

Besides, I moved the call to kmalloc() from the *t declaration
into the code (this is confusing when a variable is initialized
with the result of some call) and removed unneeded comment near
the error path.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After this patch none of the netlink callback support anything
except the initial network namespace but the rtnetlink infrastructure
now handles multiple network namespaces.

Changes from v2:
- IPv6 addrlabel processing

Changes from v1:
- no need for special rtnl_unlock handling
- fixed IPv6 ndisc
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before I can enable rtnetlink to work in all network namespaces I need
to be certain that something won't break.  So this patch deliberately
disables all of the rtnletlink methods in everything except the
initial network namespace.  After the methods have been audited this
extra check can be disabled.

Changes from v1:
- added IPv6 addrlabel protection
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Many-many code in the kernel initialized the timer->function
and  timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 9cd40029 (Fix race between
neigh_parms_release and neightbl_fill_parms) introduced device
reference counting regressions for several people, see:

	http://bugzilla.kernel.org/show_bug.cgi?id=9778

for example.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neightbl_fill_parms() is called under the write-locked tbl->lock
and accesses the parms->dev. The negh_parm_release() calls the
dev_put(parms->dev) without this lock. This creates a tiny race window
on which the parms contains potentially stale dev pointer.

To fix this race it's enough to move the dev_put() upper under the
tbl->lock, but note, that the parms are held by neighbors and thus can
live after the neigh_parms_release() is called, so we still can have a
parm with bad dev pointer.

I didn't find where the neigh->parms->dev is accessed, but still think
that putting the dev is to be done in a place, where the parms are
really freed. Am I right with that?
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

neigh_table_init_no_netlink() creates them, but they aren't removed anywhere.

Steps to reproduce:

	modprobe clip
	rmmod clip
	cat /proc/net/stat/clip_arp_cache

BUG: unable to handle kernel paging request at virtual address f89d7758
printing eip: c05a99da *pdpt = 0000000000004001 *pde = 0000000004408067 *pte = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: atm af_packet ipv6 binfmt_misc sbs sbshc fan dock battery backlight ac power_supply parport loop rtc_cmos rtc_core rtc_lib serio_raw button k8temp hwmon amd_rng sr_mod cdrom shpchp pci_hotplug ehci_hcd ohci_hcd uhci_hcd usbcore
Pid: 2082, comm: cat Not tainted (2.6.24-rc1-b1d08ac0-bloat #4)
EIP: 0060:[<c05a99da>] EFLAGS: 00210256 CPU: 0
EIP is at neigh_stat_seq_next+0x26/0x3f
EAX: 00000001 EBX: f89d7600 ECX: c587bf40 EDX: 00000000
ESI: 00000000 EDI: 00000001 EBP: 00000400 ESP: c587bf1c
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 2082, ti=c587b000 task=c5984e10 task.ti=c587b000)
Stack: c06228cc c5313790 c049e5c0 0804f000 c45a7b00 c53137b0 00000000 00000000
       00000082 00000001 00000000 00000000 00000000 fffffffb c58d6780 c049e437
       c45a7b00 c04b1f93 c587bfa0 00000400 0804f000 00000400 0804f000 c04b1f2f
Call Trace:
 [<c049e5c0>] seq_read+0x189/0x281
 [<c049e437>] seq_read+0x0/0x281
 [<c04b1f93>] proc_reg_read+0x64/0x77
 [<c04b1f2f>] proc_reg_read+0x0/0x77
 [<c048907e>] vfs_read+0x80/0xd1
 [<c0489491>] sys_read+0x41/0x67
 [<c04080fa>] sysenter_past_esp+0x6b/0xc1
 =======================
Code: e9 ec 8d 05 00 56 8b 11 53 8b 40 70 8b 58 3c eb 29 0f a3 15 80 91 7b c0 19 c0 85 c0 8d 42 01 74 17 89 c6 c1 fe 1f 89 01 89 71 04 <8b> 83 58 01 00 00 f7 d0 8b 04 90 eb 09 89 c2 83 fa 01 7e d2 31
EIP: [<c05a99da>] neigh_stat_seq_next+0x26/0x3f SS:ESP 0068:c587bf1c
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/atm/clip.c crashes the kernel if it (module) is loaded, removed,
and then loaded again.  Its exit call to neigh_table_clear()
should destroy the cache after freeing it.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- In ipv6 ndisc_ifinfo_syctl_change so it doesn't depend on binary
  sysctl names for a function that works with proc.

- In neighbour.c reorder the table to put the possibly unused entries
  at the end so we can remove them by terminating the table early.

- In neighbour.c kill the entries with questionable binary sysctl
  handling behavior.

- In neighbour.c if we don't have a strategy routine remove the
  binary path.  So we don't the default sysctl strategy routine
  on data that is not ready for it.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The pnigh_lookup is used to lookup proxy entries and to 
create them in case lookup failed. 

However, the "creation" code does not perform the re-lookup
after GFP_KERNEL allocation. This is done because the code
is expected to be protected with the RTNL lock, so add the 
assertion (mainly to address future questions from new network 
developers like me :) ).
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since hardware header operations are part of the protocol class
not the device instance, make them into a separate object and
save memory.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add inline for common usage of hardware header creation, and
fix bug in IPV6 mcast where the assumption about negative return is
an errno. Negative return from hard_header means not enough space
was available,(ie -N bytes).
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>