Similar to gre, vxlan, geneve tunnels allow IPIP6 and IP6IP6 tunnels
to operate in 'collect metadata' mode.
Unlike ipv4 code here it's possible to reuse ip6_tnl_xmit() function
for both collect_md and traditional tunnels.
bpf_skb_[gs]et_tunnel_key() helpers and ovs (in the future) are the users.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NThomas Graf <tgraf@suug.ch>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 8eb30be0 ("ipv6: Create ip6_tnl_xmit") unsets
flowi6_proto in ip4ip6_tnl_xmit() and ip6ip6_tnl_xmit().
Since xfrm_selector_match() relies on this info, IPv6 packets
sent by an ip6tunnel cannot be properly selected by their
protocols after removing it. This patch puts flowi6_proto back.

Cc: stable@vger.kernel.org
Fixes: 8eb30be0 ("ipv6: Create ip6_tnl_xmit")
Signed-off-by: NEli Cooper <elicooper@gmx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is a preparatory patch for converting qdisc linked list into a
hashtable. As we'll need to include hashtable.h in netdevice.h, we first
have to make sure that this will not introduce symbol conflicts for any of
the netdevice.h users.
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since iptunnel_handle_offloads() is called in all paths we can
probably drop the block in ip6_tnl_xmit that was checking for
skb->encapsulation and resetting the inner headers.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to set dev features, use same values that are used in GREv6.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add netlink and setup for encapsulation
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add encap_hlen and ip_tunnel_encap structure to ip6_tnl. Add functions
for getting encap hlen, setting up encap on a tunnel, performing
encapsulation operation.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Protocol for 4in6 tunnel is IPPROTO_IPIP. This was wrongly changed by
the last cleanup.

CC: Tom Herbert <tom@herbertland.com>
Fixes: 0d3c703a ("ipv6: Cleanup IPv6 tunnel receive path")
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We only need to reset network header here.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A few generic changes to generalize tunnels in IPv6:
  - Export ip6_tnl_change_mtu so that it can be called by ip6_gre
  - Add tun_hlen to ip6_tnl structure.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch renames ip6_tnl_xmit2 to ip6_tnl_xmit and exports it. Other
users like GRE will be able to call this. The original ip6_tnl_xmit
function is renamed to ip6_tnl_start_xmit (this is an ndo_start_xmit
function).
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some basic changes to make IPv6 tunnel receive path look more like
IPv4 path:
  - Make ip6_tnl_rcv non-static so that GREv6 and others can call it
  - Make ip6_tnl_rcv look like ip_tunnel_rcv
  - Switch to gro_cells_receive
  - Make ip6_tnl_rcv non-static and export it
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When creating an ip6tnl tunnel with ip tunnel, rtnl_link_ops is not set
before ip6_tnl_create2 is called. When register_netdevice is called, there
is no linkinfo attribute in the NEWLINK message because of that.

Setting rtnl_link_ops before calling register_netdevice fixes that.

Fixes: 0b112457 ("ip6tnl: add support of link creation via rtnl")
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@redhat.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPCB may contain data from previous layers (in the observed case the
qdisc layer). In the observed scenario, the data was misinterpreted as
ip header options, which later caused the ihl to be set to an invalid
value (<5). This resulted in an infinite loop in the mips implementation
of ip_fast_csum.

This patch clears IPCB(skb)->opt before dst_link_failure can be called for
various types of tunnels. This change only applies to encapsulated ipv4
packets.

The code introduced in 11c21a30 which clears all of IPCB has been removed
to be consistent with these changes, and instead the opt field is cleared
unconditionally in ip_tunnel_xmit. The change in ip_tunnel_xmit applies to
SIT, GRE, and IPIP tunnels.

The relevant vti, l2tp, and pptp functions already contain similar code for
clearing the IPCB.
Signed-off-by: NBernie Harris <bernie.harris@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This also fix a potential race into the existing tunnel code, which
could lead to the wrong dst to be permanenty cached:

CPU1:					CPU2:
  <xmit on ip6_tunnel>
  <cache lookup fails>
  dst = ip6_route_output(...)
					<tunnel params are changed via nl>
					dst_cache_reset() // no effect,
							// the cache is empty
  dst_cache_set() // the wrong dst
	// is permanenty stored
	// into the cache

With the new dst implementation the above race is not possible
since the first cache lookup after dst_cache_reset will fail due
to the timestamp check
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Suggested-and-acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the commit cdf3464e ("ipv6: Fix dst_entry refcnt bugs in ip6_tunnel")
introduced percpu storage for ip6_tunnel dst cache, but while clearing
such cache it used raw_cpu_ptr to walk the per cpu entries, so cached
dst on non current cpu are not actually reset.

This patch replaces raw_cpu_ptr with per_cpu_ptr, properly cleaning
such storage.

Fixes: cdf3464e ("ipv6: Fix dst_entry refcnt bugs in ip6_tunnel")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently error log messages in ip6_tnl_err are printed at 'warn'
level. This is different to other tunnel types which don't print
any messages. These log messages don't provide any information that
couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".

This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.
Signed-off-by: NMatt Bennett <matt.bennett@alliedtelesis.co.nz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch uses a seqlock to ensure consistency between idst->dst and
idst->cookie.  It also makes dst freeing from fib tree to undergo a
rcu grace period.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Problems in the current dst_entry cache in the ip6_tunnel:

1. ip6_tnl_dst_set is racy.  There is no lock to protect it:
   - One major problem is that the dst refcnt gets messed up. F.e.
     the same dst_cache can be released multiple times and then
     triggering the infamous dst refcnt < 0 warning message.
   - Another issue is the inconsistency between dst_cache and
     dst_cookie.

   It can be reproduced by adding and removing the ip6gre tunnel
   while running a super_netperf TCP_CRR test.

2. ip6_tnl_dst_get does not take the dst refcnt before returning
   the dst.

This patch:
1. Create a percpu dst_entry cache in ip6_tnl
2. Use a spinlock to protect the dst_cache operations
3. ip6_tnl_dst_get always takes the dst refcnt before returning
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is a prep work to fix the dst_entry refcnt bugs in
ip6_tunnel.

This patch rename:
1. ip6_tnl_dst_check() to ip6_tnl_dst_get() to better
   reflect that it will take a dst refcnt in the next patch.
2. ip6_tnl_dst_store() to ip6_tnl_dst_set() to have a more
   conventional name matching with ip6_tnl_dst_get().
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the meaning of net.ipv6.auto_flowlabels to provide a mode for
automatic flow labels generation. There are four modes:

0: flow labels are disabled
1: flow labels are enabled, sockets can opt-out
2: flow labels are allowed, sockets can opt-in
3: flow labels are enabled and enforced, no opt-out for sockets

np->autoflowlabel is initialized according to the sysctl value.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can't call skb_get_hash here since the packet is not complete to do
flow_dissector. Create hash based on flowi6 instead.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of doing the rt6->rt6i_node check whenever we need
to get the route's cookie.  Refactor it into rt6_get_cookie().
It is a prep work to handle FLOWI_FLAG_KNOWN_NH and also
percpu rt6_info later.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

That was we can make sure the output path of ipv4/ipv6 operate on
the UDP socket rather than whatever random thing happens to be in
skb->sk.

Based upon a patch by Jiri Pirko.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>

Don't use dev->iflink anymore.

CC: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Those are counterparts to nla_put_in_addr and nla_put_in6_addr.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
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>

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>

After commit 2b0bb01b, the kernel returns -ENOBUFS when user tries to add
an existing tunnel with ioctl API:
$ ip -6 tunnel add ip6tnl1 mode ip6ip6 dev eth1
add tunnel "ip6tnl0" failed: No buffer space available

It's confusing, the right error is EEXIST.

This patch also change a bit the code returned:
 - ENOBUFS -> ENOMEM
 - ENOENT -> ENODEV

Fixes: 2b0bb01b ("ip6_tunnel: Return an error when adding an existing tunnel.")
CC: Steffen Klassert <steffen.klassert@secunet.com>
Reported-by: NPierre Cheynier <me@pierre-cheynier.net>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The IP6_TNL_TRACE macro is no longer used anywhere in the code so remove definition.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement rtnl_link_ops->get_link_net() callback so that IFLA_LINK_NETNSID is
added to rtnetlink messages.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
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>

This patch adds support for tunnels with local or
remote wildcard endpoints. With this we get a
NBMA tunnel mode like we have it for ipv4 and
sit tunnels.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we need the IP6_TNL_F_CAP_XMIT capabiltiy to transmit
packets through an ipv6 tunnel. This capability is set when the
tunnel gets configured, based on the tunnel endpoint addresses.

On tunnels with wildcard tunnel endpoints, we need to do the
capabiltiy checking on a per packet basis like it is done in
the receive path.

This patch extends ip6_tnl_xmit_ctl() to take local and remote
addresses as parameters to allow for per packet capabiltiy
checking.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip6_tnl_dev_init() sets the dev->iflink via a call to
ip6_tnl_link_config(). After that, register_netdevice()
sets dev->iflink = -1. So we loose the iflink configuration
for ipv6 tunnels. Fix this by using ip6_tnl_dev_init() as the
ndo_init function. Then ip6_tnl_dev_init() is called after
dev->iflink is set to -1 from register_netdevice().
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The fallback device is in ipv6 mode by default.
The mode can not be changed in runtime, so there
is no way to decapsulate ip4in6 packets coming from
various sources without creating the specific tunnel
ifaces for each peer.

This allows to update the fallback tunnel device, but only
the mode could be changed. Usual command should work for the
fallback device: `ip -6 tun change ip6tnl0 mode any`

The fallback device can not be hidden from the packet receiver
as a regular tunnel, but there is no need for synchronization
as long as we do single assignment.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NAlexey Andriyanov <alan@al-an.info>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Testing xmit_more support with netperf and connected UDP sockets,
I found strange dst refcount false sharing.

Current handling of IFF_XMIT_DST_RELEASE is not optimal.

Dropping dst in validate_xmit_skb() is certainly too late in case
packet was queued by cpu X but dequeued by cpu Y

The logical point to take care of drop/force is in __dev_queue_xmit()
before even taking qdisc lock.

As Julian Anastasov pointed out, need for skb_dst() might come from some
packet schedulers or classifiers.

This patch adds new helper to cleanly express needs of various drivers
or qdiscs/classifiers.

Drivers that need skb_dst() in their ndo_start_xmit() should call
following helper in their setup instead of the prior :

	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
->
	netif_keep_dst(dev);

Instead of using a single bit, we use two bits, one being
eventually rebuilt in bonding/team drivers.

The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
rebuilt in bonding/team. Eventually, we could add something
smarter later.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>