Recently I had a kernel panic in icmp_send during a network namespace
cleanup.  There were packets in the arp queue that failed to be sent
and we attempted to generate an ICMP host unreachable message, but
failed because icmp_sk_exit had already been called.

The network devices are removed from a network namespace and their
arp queues are flushed before we do attempt to shutdown subsystems
so this error should have been impossible.

It turns out icmp_init is using register_pernet_device instead
of register_pernet_subsys.  Which resulted in icmp being shut down
while we still had the possibility of packets in flight, making
a nasty NULL pointer deference in interrupt context possible.

Changing this to register_pernet_subsys fixes the problem in
my testing.
Signed-off-by: NEric W. Biederman <ebiederm@aristanetworks.com>
Acked-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass netns to xfrm_lookup()/__xfrm_lookup(). For that pass netns
to flow_cache_lookup() and resolver callback.

Take it from socket or netdevice. Stub DECnet to init_net.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can reduce pressure on dst entry refcount that slowdown UDP transmit
path on SMP machines. This pressure is visible on RTP servers when
delivering content to mediagateways, especially big ones, handling
thousand of streams. Several cpus send UDP frames to the same
destination, hence use the same dst entry.

This patch makes ip_append_data() eventually steal the refcount its
callers had to take on the dst entry.

This doesnt avoid all refcounting, but still gives speedups on SMP,
on UDP/RAW transmit path
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ifdef out
* struct sk_buff::sp		(pointer)
* struct dst_entry::xfrm	(pointer)
* struct sock::sk_policy	(2 pointers)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clean up the various different email addresses of mine listed in the code
to a single current and valid address. As Dave says his network merges
for 2.6.28 are now done this seems a good point to send them in where
they won't risk disrupting real changes.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass namespace into icmp_xmit_lock, obtain socket inside and return
it as a result for caller.

Thanks Alexey Dobryan for this report:

Steps to reproduce:

	CONFIG_PREEMPT=y
	CONFIG_DEBUG_PREEMPT=y
	tracepath <something>

BUG: using smp_processor_id() in preemptible [00000000] code: tracepath/3205
caller is icmp_sk+0x15/0x30
Pid: 3205, comm: tracepath Not tainted 2.6.27-rc4 #1

Call Trace:
 [<ffffffff8031af14>] debug_smp_processor_id+0xe4/0xf0
 [<ffffffff80409405>] icmp_sk+0x15/0x30
 [<ffffffff8040a17b>] icmp_send+0x4b/0x3f0
 [<ffffffff8025a415>] ? trace_hardirqs_on_caller+0xd5/0x160
 [<ffffffff8025a4ad>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff8023a475>] ? local_bh_enable_ip+0x95/0x110
 [<ffffffff804285b9>] ? _spin_unlock_bh+0x39/0x40
 [<ffffffff8025a26c>] ? mark_held_locks+0x4c/0x90
 [<ffffffff8025a4ad>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff8025a415>] ? trace_hardirqs_on_caller+0xd5/0x160
 [<ffffffff803e91b4>] ip_fragment+0x8d4/0x900
 [<ffffffff803e7030>] ? ip_finish_output2+0x0/0x290
 [<ffffffff803e91e0>] ? ip_finish_output+0x0/0x60
 [<ffffffff803e6650>] ? dst_output+0x0/0x10
 [<ffffffff803e922c>] ip_finish_output+0x4c/0x60
 [<ffffffff803e92e3>] ip_output+0xa3/0xf0
 [<ffffffff803e68d0>] ip_local_out+0x20/0x30
 [<ffffffff803e753f>] ip_push_pending_frames+0x27f/0x400
 [<ffffffff80406313>] udp_push_pending_frames+0x233/0x3d0
 [<ffffffff804067d1>] udp_sendmsg+0x321/0x6f0
 [<ffffffff8040d155>] inet_sendmsg+0x45/0x80
 [<ffffffff803b967f>] sock_sendmsg+0xdf/0x110
 [<ffffffff8024a100>] ? autoremove_wake_function+0x0/0x40
 [<ffffffff80257ce5>] ? validate_chain+0x415/0x1010
 [<ffffffff8027dc10>] ? __do_fault+0x140/0x450
 [<ffffffff802597d0>] ? __lock_acquire+0x260/0x590
 [<ffffffff803b9e55>] ? sockfd_lookup_light+0x45/0x80
 [<ffffffff803ba50a>] sys_sendto+0xea/0x120
 [<ffffffff80428e42>] ? _spin_unlock_irqrestore+0x42/0x80
 [<ffffffff803134bc>] ? __up_read+0x4c/0xb0
 [<ffffffff8024e0c6>] ? up_read+0x26/0x30
 [<ffffffff8020b8bb>] system_call_fastpath+0x16/0x1b

icmp6_sk() is similar.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

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

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

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

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

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

Some places, that deal with ICMP statistics already have where
to get a struct net from, but use it directly, without declaring
a separate variable on the stack.

Since I will need this net soon, I declare a struct net on the
stack and use it in the existing places in a separate patch not
to spoil the future ones.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This routine deals with ICMP statistics, but doesn't have a
struct net at hands, so add one.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add struct net_device parameter to ip_rt_frag_needed() and update MTU to
cache entries where ifindex is specified. This is similar to what is
already done in ip_rt_redirect().
Signed-off-by: NTimo Teras <timo.teras@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

What do_gettimeofday() does is to call getnstimeofday() and
to convert the result from timespec{} to timeval{}.
After that, these callers convert the result again to msec.
Use getnstimeofday() and convert the units at once.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes the needlessly global icmp_sk_init() static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And use %u to format port.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace sock_create_kern with inet_ctl_sock_create.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ICMP relookup path is only meant to modify behaviour when
appropriate IPsec policies are in place and marked as requiring
relookups.  It is certainly not meant to modify behaviour when
IPsec policies don't exist at all.

However, due to an oversight on the error paths existing behaviour
may in fact change should one of the relookup steps fail.

This patch corrects this by redirecting all errors on relookup
failures to the previous code path.  That is, if the initial
xfrm_lookup let the packet pass, we will stand by that decision
should the relookup fail due to an error.

This should be safe from a security point-of-view because compliant
systems must install a default deny policy so the packet would'nt
have passed in that case.

Many thanks to Julian Anastasov for pointing out this error.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 8b7817f3 ([IPSEC]: Add ICMP host
relookup support) introduced some dst leaks on error paths: the rt
pointer can be forgotten to be put. Fix it bu going to a proper label.

Found after net namespace's lo refused to unregister :) Many thanks to 
Den for valuable help during debugging.

Herbert pointed out, that xfrm_lookup() will put the rtable in case
of error itself, so the first goto fix is redundant.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

This mostly re-uses the net, used in icmp netnsization patches from Denis.

After this ICMP sysctls are completely virtualized.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initialization is moved to icmp_sk_init, all the places, that
refer to them use init_net for now.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid 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: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

(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: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Functions from __exit section should not be called from ones in __init
section. Fix this conflict.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All preparations are done. Now just add a hook to perform an
initialization on namespace startup and replace icmp_sk macro with
proper inline call.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So, change icmp(v6)_sk creation/disposal to the scheme used in the
netlink for rtnl, i.e. create a socket in the context of the init_net
and assign the namespace without getting a referrence later.

Also use sk_release_kernel instead of sock_release to properly destroy
such sockets.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Own __icmp(v6)_sk should be present in each namespace. So, it should be
allocated dynamically. Though, alloc_percpu does not fit the case as it
implies additional dereferrence for no bonus.

Allocate data for pointers just like __percpu_alloc_mask does and place
pointers to struct sock into this array.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have to get socket lock inside icmp(v6)_xmit_lock/unlock. The socket
is get from global variable now. When this code became namespaces, one
should pass a namespace and get socket from it.

Though, above is useless. Socket is available in the caller, just pass
it inside. This saves a bit of code now and saves more later.

add/remove: 0/0 grow/shrink: 1/3 up/down: 1/-169 (-168)
function                                     old     new   delta
icmp_rcv                                     718     719      +1
icmpv6_rcv                                  2343    2303     -40
icmp_send                                   1566    1518     -48
icmp_reply                                   549     468     -81
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Basically, there is no difference, what to store: socket or sock. Though,
sock looks better as there will be 1 less dereferrence on the fast path.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use this macro only once in a function to save a bit of space.

add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-98 (-98)
function                                     old     new   delta
icmp_reply                                   562     561      -1
icmp_push_reply                              305     258     -47
icmp_init                                    273     223     -50
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

icmp_init could fail and this is normal for namespace other than initial.
So, the panic should be triggered only on init_net initialization path.

Additionally create rollback path for icmp_init as a separate function.
It will also be used later during namespace destruction.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct net_proto_family* is not used in icmp[v6]_init, ndisc_init,
igmp_init and tcp_v4_init. Remove it.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Somewhere along the development of my ICMP relookup patch the header
length check went AWOL on the non-IPsec path.  This patch restores the
check.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All needed API is done, the namespace is available when required from
the device on the DST entry from the incoming packet. So, just replace
init_net with proper namespace.

Other protocols will follow.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Basically, this piece looks relatively easy. Namespace is already
available on the dst entry via device and the device is safe to
dereferrence. Compare it with one of a searcher and skip entry if
appropriate.

The only exception is ip_rt_frag_needed. So, add namespace parameter to it.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>