On the output paths in particular, we have to sometimes deal with two
socket contexts.  First, and usually skb->sk, is the local socket that
generated the frame.

And second, is potentially the socket used to control a tunneling
socket, such as one the encapsulates using UDP.

We do not want to disassociate skb->sk when encapsulating in order
to fix this, because that would break socket memory accounting.

The most extreme case where this can cause huge problems is an
AF_PACKET socket transmitting over a vxlan device.  We hit code
paths doing checks that assume they are dealing with an ipv4
socket, but are actually operating upon the AF_PACKET one.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IP addresses are often stored in netlink attributes. Add generic functions
to do that.

For nla_put_in_addr, it would be nicer to pass struct in_addr but this is
not used universally throughout the kernel, in way too many places __be32 is
used to store IPv4 address.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv6 code uses a mixture of coding styles. In some instances check for NULL
pointer is done as x == NULL and sometimes as !x. !x is preferred according to
checkpatch and this patch makes the code consistent by adopting the latter
form.

No changes detected by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A local route may have a lower hop_limit set than global routes do.

RFC 3756, Section 4.2.7, "Parameter Spoofing"

>   1.  The attacker includes a Current Hop Limit of one or another small
>       number which the attacker knows will cause legitimate packets to
>       be dropped before they reach their destination.

>   As an example, one possible approach to mitigate this threat is to
>   ignore very small hop limits.  The nodes could implement a
>   configurable minimum hop limit, and ignore attempts to set it below
>   said limit.
Signed-off-by: ND.S. Ljungmark <ljungmark@modio.se>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref.  We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.

So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref.  Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function.  I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.

To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq.  So that the static size of the key would be
available.

I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Add protocol to neigh_tbl so that dst->ops->protocol is not needed
- Acquire the device from neigh->dev

This results in a neigh_hh_init that will cache the samve values
regardless of the packets flowing through it.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4429 ("Optimistic DAD") states that optimistic addresses
should be treated as deprecated addresses.  From section 2.1:

   Unless noted otherwise, components of the IPv6 protocol stack
   should treat addresses in the Optimistic state equivalently to
   those in the Deprecated state, indicating that the address is
   available for use but should not be used if another suitable
   address is available.

Optimistic addresses are indeed avoided when other addresses are
available (i.e. at source address selection time), but they have
not heretofore been available for things like explicit bind() and
sendmsg() with struct in6_pktinfo, etc.

This change makes optimistic addresses treated more like
deprecated addresses than tentative ones.
Signed-off-by: NErik Kline <ek@google.com>
Acked-by: NLorenzo Colitti <lorenzo@google.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The kernel forcefully applies MTU values received in router
advertisements provided the new MTU is less than the current. This
behavior is undesirable when the user space is managing the MTU. Instead
a sysctl flag 'accept_ra_mtu' is introduced such that the user space
can control whether or not RA provided MTU updates should be applied. The
default behavior is unchanged; user space must explicitly set this flag
to 0 for RA MTUs to be ignored.
Signed-off-by: NHarout Hedeshian <harouth@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change has no functional impact and simply addresses some coding
style issues detected by checkpatch. Specifically this change
adjusts "if" statements which also include the assignment of a
variable.

No changes to the resultant object files result as determined by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there are only three neigh tables in the whole kernel:
arp table, ndisc table and decnet neigh table. What's more,
we don't support registering multiple tables per family.
Therefore we can just make these tables statically built-in.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes no changes to the logic of the code but simply addresses
coding style issues as detected by checkpatch.

Both objdump and diff -w show no differences.

This patch removes some blank lines between the end of a function
definition and the EXPORT_SYMBOL_GPL macro in order to prevent
checkpatch warning that EXPORT_SYMBOL must immediately follow
a function.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes no changes to the logic of the code but simply addresses
coding style issues as detected by checkpatch.

Both objdump and diff -w show no differences.

A number of items are addressed in this patch:
* Multiple spaces converted to tabs
* Spaces before tabs removed.
* Spaces in pointer typing cleansed (char *)foo etc.
* Remove space after sizeof
* Ensure spacing around comparators such as if statements.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In this file, function names are otherwise used as pointers without &.

A simplified version of the Coccinelle semantic patch that makes this
change is as follows:

// <smpl>
@r@
identifier f;
@@

f(...) { ... }

@@
identifier r.f;
@@

- &f
+ f
// </smpl>
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

d9333196(ipv6:  Allow accepting RA from local IP addresses.) made the wrong
check, whether or not to accept RA with source-addr found on local machine, when
accept_ra_from_local is 0.

Fixes: d9333196(ipv6:  Allow accepting RA from local IP addresses.)
Cc: Ben Greear <greearb@candelatech.com>
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This can be used in virtual networking applications, and
may have other uses as well.  The option is disabled by
default.

A specific use case is setting up virtual routers, bridges, and
hosts on a single OS without the use of network namespaces or
virtual machines.  With proper use of ip rules, routing tables,
veth interface pairs and/or other virtual interfaces,
and applications that can bind to interfaces and/or IP addresses,
it is possibly to create one or more virtual routers with multiple
hosts attached.  The host interfaces can act as IPv6 systems,
with radvd running on the ports in the virtual routers.  With the
option provided in this patch enabled, those hosts can now properly
obtain IPv6 addresses from the radvd.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is disabled by default, just like similar debug info
already in this module.  But, makes it easier to find out
why RA is not being accepted when debugging strange behaviour.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4861 states in 7.2.5:

	The IsRouter flag in the cache entry MUST be set based on the
         Router flag in the received advertisement.  In those cases
         where the IsRouter flag changes from TRUE to FALSE as a result
         of this update, the node MUST remove that router from the
         Default Router List and update the Destination Cache entries
         for all destinations using that neighbor as a router as
         specified in Section 7.3.3.  This is needed to detect when a
         node that is used as a router stops forwarding packets due to
         being configured as a host.

Currently, when dealing with NA Message which IsRouter flag changes from
TRUE to FALSE, the kernel only removes router from the Default Router List,
and don't update the Destination Cache entries.

Now in order to update those Destination Cache entries, i introduce
function rt6_clean_tohost().
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will be needed later on to provide better management of default values.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts the neigh param members to an array. This allows easier
manipulation which will be needed later on to provide better management of
default values.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when dealing with a RA message, if accept_ra_defrtr is false,
the kernel will not add the default route, and then deal with
the following route information options. Unfortunately, those
options maybe contain default route, so let's judge the
accept_ra_defrtr before calling rt6_route_rcv.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_SYSCTL=n the following build warning happens:

net/ipv6/ndisc.c:1730:1: warning: label 'out' defined but not used [-Wunused-label]

The 'out' label is only used when CONFIG_SYSCTL=y, so move it inside the
'ifdef CONFIG_SYSCTL' block.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When loading the ipv6 module, ndisc_init() is called before
ip6_route_init(). As the former registers a handler calling
fib6_run_gc(), this opens a window to run the garbage collector
before necessary data structures are initialized. If a network
device is initialized in this window, adding MAC address to it
triggers a NETDEV_CHANGEADDR event, leading to a crash in
fib6_clean_all().

Take the event handler registration out of ndisc_init() into a
separate function ndisc_late_init() and move it after
ip6_route_init().
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4861 says that the IP source address of the Redirect is the
same as the current first-hop router for the specified ICMP
Destination Address, so the gateway should be taken into
consideration when we find the route for redirect.

There was once a check in commit
a6279458 ("NDISC: Search over
all possible rules on receipt of redirect.") and the check
went away in commit b94f1c09
("ipv6: Use icmpv6_notify() to propagate redirect, instead of
rt6_redirect()").

The bug is only "exploitable" on layer-2 because the source
address of the redirect is checked to be a valid link-local
address but it makes spoofing a lot easier in the same L2
domain nonetheless.

Thanks very much for Hannes's help.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allocating skbs when sending out neighbour discovery messages
currently uses sock_alloc_send_skb() based on a per net namespace
socket and thus share a socket wmem buffer space.

If a netdevice is temporarily unable to transmit due to carrier
loss or for other reasons, the queued up ndisc messages will cosnume
all of the wmem space and will thus prevent from any more skbs to
be allocated even for netdevices that are able to transmit packets.

The number of neighbour discovery messages sent is very limited,
use of alloc_skb() bypasses the socket wmem buffer size enforcement
while the manual call to skb_set_owner_w() maintains the socket
reference needed for the IPv6 output path.

This patch has orginally been posted by Eric Dumazet in a modified
form.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Fabio Estevam <festevam@gmail.com>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Tested-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This config option is superfluous in that it only guards a call
to neigh_app_ns(). Enabling CONFIG_ARPD by default has no
change in behavior. There will now be call to __neigh_notify()
for each ARP resolution, which has no impact unless there is a
user space daemon waiting to receive the notification, i.e.,
the case for which CONFIG_ARPD was designed anyways.
Suggested-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Joe Perches <joe@perches.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the IPv6 version of "arp_reduce", ndisc_send_na()
will be needed.

Cc: David S. Miller <davem@davemloft.net>
Cc: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 1f324e38.

It seems to cause regressions, and in particular the output path
really depends upon there being a socket attached to skb->sk for
checks such as sk_mc_loop(skb->sk) for example.  See ip6_output_finish2().
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Reported-by: NFabio Estevam <festevam@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A sk variable initialized to ndisc_sk is already available outside
of the branch.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allocating skbs when sending out neighbour discovery messages
currently uses sock_alloc_send_skb() based on a per net namespace
socket and thus share a socket wmem buffer space.

If a netdevice is temporarily unable to transmit due to carrier
loss or for other reasons, the queued up ndisc messages will cosnume
all of the wmem space and will thus prevent from any more skbs to
be allocated even for netdevices that are able to transmit packets.

The number of neighbour discovery messages sent is very limited,
simply use alloc_skb() and don't depend on any socket wmem space any
longer.

This patch has orginally been posted by Eric Dumazet in a modified
form.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements RFC6980: Drop fragmented ndisc packets by
default. If a fragmented ndisc packet is received the user is informed
that it is possible to disable the check.

Cc: Fernando Gont <fernando@gont.com.ar>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rfc 4861 says the Redirected Header option is optional, so
the kernel should not drop the Redirect Message that has no
Redirected Header option. In this patch, the function
ip6_redirect_no_header() is introduced to deal with that
condition.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>

On a high-traffic router with many processors and many IPv6 dst
entries, soft lockup in fib6_run_gc() can occur when number of
entries reaches gc_thresh.

This happens because fib6_run_gc() uses fib6_gc_lock to allow
only one thread to run the garbage collector but ip6_dst_gc()
doesn't update net->ipv6.ip6_rt_last_gc until fib6_run_gc()
returns. On a system with many entries, this can take some time
so that in the meantime, other threads pass the tests in
ip6_dst_gc() (ip6_rt_last_gc is still not updated) and wait for
the lock. They then have to run the garbage collector one after
another which blocks them for quite long.

Resolve this by replacing special value ~0UL of expire parameter
to fib6_run_gc() by explicit "force" parameter to choose between
spin_lock_bh() and spin_trylock_bh() and call fib6_run_gc() with
force=false if gc_thresh is reached but not max_size.
Signed-off-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDaniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since some refactoring in 5f5a0115, ndisc_send_redirect called
ndisc_fill_redirect_hdr_option on the wrong skb, leading to data corruption or
in the worst case a panic when the skb_put failed.
Signed-off-by: NMatthias Schiffer <mschiffer@universe-factory.net>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

send_sllao is already initialized with the value of dev->addr_len

Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Construct NS/NA/RS message directly using C99 compound literals.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>