commit "ip_gre: allow CSUM capable devices to handle packets"
aa0e51cd, broke GRE_CSUM case.
GRE_CSUM needs checksum computed for inner packet. Therefore
csum-calculation can not be offloaded if tunnel device requires
GRE_CSUM.  Following patch fixes it by computing inner packet checksum
for GRE_CSUM type, for all other type of GRE devices csum is offloaded.

CC: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Acked-by: NDmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GRE-GSO generates ip fragments with id 0,2,3,4... for every
GSO packet, which is not correct. Following patch fixes it
by setting ip-header id unique id of fragments are allowed.
As Eric Dumazet suggested it is optimized by using inner ip-header
whenever inner packet is ipv4.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 68c33163 (v4 GRE: Add TCP segmentation offload for GRE)
introduced a bug in error path.

dst is attached to skb, so will be released when skb is freed.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If device is not able to handle checksumming it will
be handled in dev_xmit
Signed-off-by: NDmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Following patch adds GRE protocol offload handler so that
skb_gso_segment() can segment GRE packets.
SKB GSO CB is added to keep track of total header length so that
skb_segment can push entire header. e.g. in case of GRE, skb_segment
need to push inner and outer headers to every segment.
New NETIF_F_GRE_GSO feature is added for devices which support HW
GRE TSO offload. Currently none of devices support it therefore GRE GSO
always fall backs to software GSO.

[ Compute pkt_len before ip_local_out() invocation. -DaveM ]
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A GRE tunnel can be configured so that outgoing tunnel packets inherit
the value of the TOS field from the inner IP header. In doing so, when
a non-IP packet is transmitted through the tunnel, the TOS field will
always be set to 0.

Instead, the user should be able to configure a different TOS value as
the fallback to use for non-IP packets. This is helpful when the non-IP
packets are all control packets and should be handled by routers outside
the tunnel as having Internet Control precedence. One example of this is
the NHRP packets that control a DMVPN-compatible mGRE tunnel; they are
encapsulated directly by GRE and do not contain an inner IP header.

Under the existing behavior, the IFLA_GRE_TOS parameter must be set to
'1' for the TOS value to be inherited. Now, only the least significant
bit of this parameter must be set to '1', and when a non-IP packet is
sent through the tunnel, the upper 6 bits of this same parameter will be
copied into the TOS field. (The ECN bits get masked off as before.)

This behavior is backwards-compatible with existing configurations and
iproute2 versions.
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pravin Shelar mentioned that GSO could potentially generate
wrong TX checksum if skb has fragments that are overwritten
by the user between the checksum computation and transmit.

He suggested to linearize skbs but this extra copy can be
avoided for normal tcp skbs cooked by tcp_sendmsg().

This patch introduces a new SKB_GSO_SHARED_FRAG flag, set
in skb_shinfo(skb)->gso_type if at least one frag can be
modified by the user.

Typical sources of such possible overwrites are {vm}splice(),
sendfile(), and macvtap/tun/virtio_net drivers.

Tested:

$ netperf -H 7.7.8.84
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
7.7.8.84 () port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    3959.52

$ netperf -H 7.7.8.84 -t TCP_SENDFILE
TCP SENDFILE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.8.84 ()
port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    3216.80

Performance of the SENDFILE is impacted by the extra allocation and
copy, and because we use order-0 pages, while the TCP_STREAM uses
bigger pages.
Reported-by: NPravin Shelar <pshelar@nicira.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to IP_GRE GSO support, GRE can recieve non linear skb which
results in panic in case of GRE_CSUM.  Following patch fixes it by
using correct csum API.

Bug introduced in commit 6b78f16e (gre: add GSO support)
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipgre_tunnel_xmit() incorrectly sets transport header to inner payload
instead of GRE header. It seems copy-and-pasted from ipip.c.
So set transport header to gre header.
(In ipip case the transport header is the inner ip header, so that's
correct.)

Found by inspection. In practice the incorrect transport header
doesn't matter because the skb usually is sent to another net_device
or socket, so the transport header isn't referenced.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Once skb_realloc_headroom() is called, tiph might point to freed memory.

Cache tiph->ttl value before the reallocation, to avoid unexpected
behavior.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipgre_tunnel_xmit() parses network header as IP unconditionally.
But transmitting packets are not always IP packet. For example such packet
can be sent by packet socket with sockaddr_ll.sll_protocol set.
So make the function check if skb->protocol is IP.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.

Settings that merely control a single network device are allowed.
Either the network device is a logical network device where
restrictions make no difference or the network device is hardware NIC
that has been explicity moved from the initial network namespace.

In general policy and network stack state changes are allowed
while resource control is left unchanged.

Allow creating raw sockets.
Allow the SIOCSARP ioctl to control the arp cache.
Allow the SIOCSIFFLAG ioctl to allow setting network device flags.
Allow the SIOCSIFADDR ioctl to allow setting a netdevice ipv4 address.
Allow the SIOCSIFBRDADDR ioctl to allow setting a netdevice ipv4 broadcast address.
Allow the SIOCSIFDSTADDR ioctl to allow setting a netdevice ipv4 destination address.
Allow the SIOCSIFNETMASK ioctl to allow setting a netdevice ipv4 netmask.
Allow the SIOCADDRT and SIOCDELRT ioctls to allow adding and deleting ipv4 routes.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting gre tunnels.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting ipip tunnels.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting ipsec virtual tunnel interfaces.

Allow setting the MRT_INIT, MRT_DONE, MRT_ADD_VIF, MRT_DEL_VIF, MRT_ADD_MFC,
MRT_DEL_MFC, MRT_ASSERT, MRT_PIM, MRT_TABLE socket options on multicast routing
sockets.

Allow setting and receiving IPOPT_CIPSO, IP_OPT_SEC, IP_OPT_SID and
arbitrary ip options.

Allow setting IP_SEC_POLICY/IP_XFRM_POLICY ipv4 socket option.
Allow setting the IP_TRANSPARENT ipv4 socket option.
Allow setting the TCP_REPAIR socket option.
Allow setting the TCP_CONGESTION socket option.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The defitions of for_each_ip_tunnel_rcu() are same,
so unify it. Also, don't hide the parameter 't'.

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

__IPTUNNEL_XMIT() is an ugly macro, convert it to a static
inline function, so make it more readable.

IPTUNNEL_XMIT() is unused, just remove it.

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

Use be16 consistently when looking at flags.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add GRO capability to IPv4 GRE tunnels, using the gro_cells
infrastructure.

Tested using IPv4 and IPv6 TCP traffic inside this tunnel, and
checking GRO is building large packets.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Linux tunnels were written before RFC6040 and therefore never
implemented the corner case of ECN getting set in the outer header
and the inner header not being ready for it.

Section 4.2.  Default Tunnel Egress Behaviour.
 o If the inner ECN field is Not-ECT, the decapsulator MUST NOT
      propagate any other ECN codepoint onwards.  This is because the
      inner Not-ECT marking is set by transports that rely on dropped
      packets as an indication of congestion and would not understand or
      respond to any other ECN codepoint [RFC4774].  Specifically:

      *  If the inner ECN field is Not-ECT and the outer ECN field is
         CE, the decapsulator MUST drop the packet.

      *  If the inner ECN field is Not-ECT and the outer ECN field is
         Not-ECT, ECT(0), or ECT(1), the decapsulator MUST forward the
         outgoing packet with the ECN field cleared to Not-ECT.

This patch moves the ECN decap logic out of the individual tunnels
into a common place.

It also adds logging to allow detecting broken systems that
set ECN bits incorrectly when tunneling (or an intermediate
router might be changing the header).

Overloads rx_frame_error to keep track of ECN related error.

Thanks to Chris Wright who caught this while reviewing the new VXLAN
tunnel.

This code was tested by injecting faulty logic in other end GRE
to send incorrectly encapsulated packets.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The gre function pointers for receive and error handling are
always called (from gre.c) with rcu_read_lock already held.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GRE driver incorrectly uses zero as a flag value. Zero is a perfectly
valid value for key, and the tunnel should match packets with no key only
with tunnels created without key, and vice versa.

This is a slightly visible  change since previously it might be possible to
construct a working tunnel that sent key 0 and received only because
of the key wildcard of zero.  I.e the sender sent key of zero, but tunnel
was defined without key.

Note: using gre key 0 requires iproute2 utilities v3.2 or later.
The original utility code was broken as well.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add GSO support to GRE tunnels.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to allow prefixed routes, we have to adjust how rt_gateway
is set and interpreted.

The new interpretation is:

1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr

2) rt_gateway != 0, destination requires a nexthop gateway

Abstract the fetching of the proper nexthop value using a new
inline helper, rt_nexthop(), as suggested by Joe Perches.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NVijay Subramanian <subramanian.vijay@gmail.com>

This will be used so that we can compose a full flow key.

Even though we have a route in this context, we need more.  In the
future the routes will be without destination address, source address,
etc. keying.  One ipv4 route will cover entire subnets, etc.

In this environment we have to have a way to possess persistent storage
for redirects and PMTU information.  This persistent storage will exist
in the FIB tables, and that's why we'll need to be able to rebuild a
full lookup flow key here.  Using that flow key will do a fib_lookup()
and create/update the persistent entry.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

With ip_rt_frag_needed() removed, we have to explicitly update PMTU
information in every ICMP error handler.

Create two helper functions to facilitate this.

1) ipv4_sk_update_pmtu()

   This updates the PMTU when we have a socket context to
   work with.

2) ipv4_update_pmtu()

   Raw version, used when no socket context is available.  For this
   interface, we essentially just pass in explicit arguments for
   the flow identity information we would have extracted from the
   socket.

   And you'll notice that ipv4_sk_update_pmtu() is simply implemented
   in terms of ipv4_update_pmtu()

Note that __ip_route_output_key() is used, rather than something like
ip_route_output_flow() or ip_route_output_key().  This is because we
absolutely do not want to end up with a route that does IPSEC
encapsulation and the like.  Instead, we only want the route that
would get us to the node described by the outermost IP header.
Reported-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix checkpatch errors of the following type:
	* ERROR: "foo * bar" should be "foo *bar"
	* ERROR: "(foo*)" should be "(foo *)"
Signed-off-by: NDaniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert the per-cpu statistics kept for GRE, IPIP, and SIT tunnels
to use 64 bit statistics.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add #define pr_fmt(fmt) as appropriate.

Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files.
Standardize on "UDPLite: " for appropriate uses.
Some prefixes were previously "UDPLITE: " and "UDP-Lite: ".

Add KBUILD_MODNAME ": " to icmp and gre.
Remove embedded prefixes as appropriate.

Add missing "\n" to pr_info in gre.c.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a more current kernel messaging style.

Convert a printk block to print_hex_dump.
Coalesce formats, align arguments.
Use %s, __func__ instead of embedding function names.

Some messages that were prefixed with <foo>_close are
now prefixed with <foo>_fini.  Some ah4 and esp messages
are now not prefixed with "ip ".

The intent of this patch is to later add something like
  #define pr_fmt(fmt) "IPv4: " fmt.
to standardize the output messages.

Text size is trivially reduced. (x86-32 allyesconfig)

$ size net/ipv4/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 887888	  31558	 249696	1169142	 11d6f6	net/ipv4/built-in.o.new
 887934	  31558	 249800	1169292	 11d78c	net/ipv4/built-in.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The original spelling and bad word choice makes these comments hard to read.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace usage of random_ether_addr() with eth_hw_addr_random()
to set addr_assign_type correctly to NET_ADDR_RANDOM.

Change the trivial cases.

v2: adapt to renamed eth_hw_addr_random()
Signed-off-by: NDanny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The conversion is very similar to that made to ipv6's SIT code.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tunnel devices set NETIF_F_LLTX to bypass HARD_TX_LOCK.  Sit and
ipip set this unconditionally in ops->setup, but gre enables it
conditionally after parameter passing in ops->newlink. This is
not called during tunnel setup as below, however, so GRE tunnels are
still taking the lock.

modprobe ip_gre
ip tunnel add test0 mode gre remote 10.5.1.1 dev lo
ip link set test0 up
ip addr add 10.6.0.1 dev test0
 # cat /sys/class/net/test0/features
 # $DIR/test_tunnel_xmit 10 10.5.2.1
ip route add 10.5.2.0/24 dev test0
ip tunnel del test0

The newlink callback is only called in rtnl_netlink, and only if
the device is new, as it calls register_netdevice internally. Gre
tunnels are created at 'ip tunnel add' with ioctl SIOCADDTUNNEL,
which calls ipgre_tunnel_locate, which calls register_netdev.
rtnl_newlink is called at 'ip link set', but skips ops->newlink
and the device is up with locking still enabled. The equivalent
ipip tunnel works fine, btw (just substitute 'method gre' for
'method ipip').

On kernels before /sys/class/net/*/features was removed [1],
the first commented out line returns 0x6000 with method gre,
which indicates that NETIF_F_LLTX (0x1000) is not set. With ipip,
it reports 0x7000. This test cannot be used on recent kernels where
the sysfs file is removed (and ETHTOOL_GFEATURES does not currently
work for tunnel devices, because they lack dev->ethtool_ops).

The second commented out line calls a simple transmission test [2]
that sends on 24 cores at maximum rate. Results of a single run:

ipip:			19,372,306
gre before patch:	 4,839,753
gre after patch:	19,133,873

This patch replicates the condition check in ipgre_newlink to
ipgre_tunnel_locate. It works for me, both with oseq on and off.
This is the first time I looked at rtnetlink and iproute2 code,
though, so someone more knowledgeable should probably check the
patch. Thanks.

The tail of both functions is now identical, by the way. To avoid
code duplication, I'll be happy to rework this and merge the two.

[1] http://patchwork.ozlabs.org/patch/104610/
[2] http://kernel.googlecode.com/files/xmit_udp_parallel.cSigned-off-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can remove the rt_gateway == 0 check but we shouldn't
remove the 'dst' initialization too.

Noticed by Eric Dumazet.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It can never actually happen.  rt_gateway is either the fully resolved
flow lookup key's destination address, or the non-zero FIB entry gateway
address.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NRoland Dreier <roland@purestorage.com>

ip_gre: Set needed_headroom dynamically again

Now that all needed_headroom users have been fixed up so that
we can safely increase needed_headroom, this patch restore the
dynamic update of needed_headroom.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tunnels can force an alignment of their percpu data to reduce number of
cache lines used in fast path, or read in .ndo_get_stats()

percpu_alloc() is a very fine grained allocator, so any small hole will
be used anyway.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>