Two places defined IPV6_TCLASS_SHIFT, so we should move it into ipv6.h,
and use this macro as possible. And define ip6_tclass helper to return
tclass
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change move anycast_src_echo_reply sysctl with other ipv6 sysctls.
Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NFrancois-Xavier Le Bail <fx.lebail@yahoo.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the net_random and net_srandom macros and replaces
them with direct calls to the prandom ones. As new commits only seem to
use prandom_u32 there is no use to keep them around.
This change makes it easier to grep for users of prandom_u32.
Signed-off-by: NAruna-Hewapathirane <aruna.hewapathirane@gmail.com>
Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Suggested-by: NSimon Schneider <simon-schneider@gmx.net>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the IPv6 forwarding path we are only concerend about the outgoing
interface MTU, but also respect locked MTUs on routes. Tunnel provider
or IPSEC already have to recheck and if needed send PtB notifications
to the sending host in case the data does not fit into the packet with
added headers (we only know the final header sizes there, while also
using path MTU information).

The reason for this change is, that path MTU information can be injected
into the kernel via e.g. icmp_err protocol handler without verification
of local sockets. As such, this could cause the IPv6 forwarding path to
wrongfully emit Packet-too-Big errors and drop IPv6 packets.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: John Heffner <johnwheffner@gmail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the past the IFA_PERMANENT flag indicated, that the valid and preferred
lifetime where ignored. Since change fad8da3e ("ipv6 addrconf: fix
preferred lifetime state-changing behavior while valid_lft is infinity")
we honour at least the preferred lifetime on those addresses. As such
the valid lifetime gets recalculated and updated to 0.

If loopback address is added manually this problem does not occur.
Also if NetworkManager manages IPv6, those addresses will get added via
inet6_rtm_newaddr and thus will have a correct lifetime, too.
Reported-by: NFrançois-Xavier Le Bail <fx.lebail@yahoo.com>
Reported-by: NDamien Wyart <damien.wyart@gmail.com>
Fixes: fad8da3e ("ipv6 addrconf: fix preferred lifetime state-changing behavior while valid_lft is infinity")
Cc: Yasushi Asano <yasushi.asano@jp.fujitsu.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have to unregister chain type if this fails to register netns.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

We don't encode argument types into function names and since besides
nft_do_chain() there are only AF-specific versions, there is no risk
of confusion.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Minor nf_chain_type cleanups:

- reorder struct to plug a hoe
- rename struct module member to "owner" for consistency
- rename nf_hookfn array to "hooks" for consistency
- reorder initializers for better readability
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

In some cases we neither take a reference to the AF info nor to the
chain type, allowing the module to be unloaded while in use.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch adds a new table family and a new filter chain that you can
use to attach IPv4 and IPv6 rules. This should help to simplify
rule-set maintainance in dual-stack setups.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Add support to register chains to multiple hooks for different address
families for mixed IPv4/IPv6 tables.
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Currently the AF-specific hook functions override the chain-type specific
hook functions. That doesn't make too much sense since the chain types
are a special case of the AF-specific hooks.

Make the AF-specific hook functions the default and make the optional
chain type hooks override them.

As a side effect, the necessary code restructuring reduces the code size,
f.i. in case of nf_tables_ipv4.o:

  nf_tables_ipv4_init_net   |  -24
  nft_do_chain_ipv4         | -113
 2 functions changed, 137 bytes removed, diff: -137
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch built on top of Commit 299603e8
("net-gro: Prepare GRO stack for the upcoming tunneling support") to add
the support of the standard GRE (RFC1701/RFC2784/RFC2890) to the GRO
stack. It also serves as an example for supporting other encapsulation
protocols in the GRO stack in the future.

The patch supports version 0 and all the flags (key, csum, seq#) but
will flush any pkt with the S (seq#) flag. This is because the S flag
is not support by GSO, and a GRO pkt may end up in the forwarding path,
thus requiring GSO support to break it up correctly.

Currently the "packet_offload" structure only contains L3 (ETH_P_IP/
ETH_P_IPV6) GRO offload support so the encapped pkts are limited to
IP pkts (i.e., w/o L2 hdr). But support for other protocol type can
be easily added, so is the support for GRE variations like NVGRE.

The patch also support csum offload. Specifically if the csum flag is on
and the h/w is capable of checksumming the payload (CHECKSUM_COMPLETE),
the code will take advantage of the csum computed by the h/w when
validating the GRE csum.

Note that commit 60769a5d "ipv4: gre:
add GRO capability" already introduces GRO capability to IPv4 GRE
tunnels, using the gro_cells infrastructure. But GRO is done after
GRE hdr has been removed (i.e., decapped). The following patch applies
GRO when pkts first come in (before hitting the GRE tunnel code). There
is some performance advantage for applying GRO as early as possible.
Also this approach is transparent to other subsystem like Open vSwitch
where GRE decap is handled outside of the IP stack hence making it
harder for the gro_cells stuff to apply. On the other hand, some NICs
are still not capable of hashing on the inner hdr of a GRE pkt (RSS).
In that case the GRO processing of pkts from the same remote host will
all happen on the same CPU and the performance may be suboptimal.

I'm including some rough preliminary performance numbers below. Note
that the performance will be highly dependent on traffic load, mix as
usual. Moreover it also depends on NIC offload features hence the
following is by no means a comprehesive study. Local testing and tuning
will be needed to decide the best setting.

All tests spawned 50 copies of netperf TCP_STREAM and ran for 30 secs.
(super_netperf 50 -H 192.168.1.18 -l 30)

An IP GRE tunnel with only the key flag on (e.g., ip tunnel add gre1
mode gre local 10.246.17.18 remote 10.246.17.17 ttl 255 key 123)
is configured.

The GRO support for pkts AFTER decap are controlled through the device
feature of the GRE device (e.g., ethtool -K gre1 gro on/off).

1.1 ethtool -K gre1 gro off; ethtool -K eth0 gro off
thruput: 9.16Gbps
CPU utilization: 19%

1.2 ethtool -K gre1 gro on; ethtool -K eth0 gro off
thruput: 5.9Gbps
CPU utilization: 15%

1.3 ethtool -K gre1 gro off; ethtool -K eth0 gro on
thruput: 9.26Gbps
CPU utilization: 12-13%

1.4 ethtool -K gre1 gro on; ethtool -K eth0 gro on
thruput: 9.26Gbps
CPU utilization: 10%

The following tests were performed on a different NIC that is capable of
csum offload. I.e., the h/w is capable of computing IP payload csum
(CHECKSUM_COMPLETE).

2.1 ethtool -K gre1 gro on (hence will use gro_cells)

2.1.1 ethtool -K eth0 gro off; csum offload disabled
thruput: 8.53Gbps
CPU utilization: 9%

2.1.2 ethtool -K eth0 gro off; csum offload enabled
thruput: 8.97Gbps
CPU utilization: 7-8%

2.1.3 ethtool -K eth0 gro on; csum offload disabled
thruput: 8.83Gbps
CPU utilization: 5-6%

2.1.4 ethtool -K eth0 gro on; csum offload enabled
thruput: 8.98Gbps
CPU utilization: 5%

2.2 ethtool -K gre1 gro off

2.2.1 ethtool -K eth0 gro off; csum offload disabled
thruput: 5.93Gbps
CPU utilization: 9%

2.2.2 ethtool -K eth0 gro off; csum offload enabled
thruput: 5.62Gbps
CPU utilization: 8%

2.2.3 ethtool -K eth0 gro on; csum offload disabled
thruput: 7.69Gbps
CPU utilization: 8%

2.2.4 ethtool -K eth0 gro on; csum offload enabled
thruput: 8.96Gbps
CPU utilization: 5-6%
Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change allows to follow a recommandation of RFC4942.

- Add "anycast_src_echo_reply" sysctl to control the use of anycast addresses
  as source addresses for ICMPv6 echo reply. This sysctl is false by default
  to preserve existing behavior.
- Add inline check ipv6_anycast_destination().
- Use them in icmpv6_echo_reply().

Reference:
RFC4942 - IPv6 Transition/Coexistence Security Considerations
   (http://tools.ietf.org/html/rfc4942#section-2.1.6)

2.1.6. Anycast Traffic Identification and Security

   [...]
   To avoid exposing knowledge about the internal structure of the
   network, it is recommended that anycast servers now take advantage of
   the ability to return responses with the anycast address as the
   source address if possible.
Signed-off-by: NFrancois-Xavier Le Bail <fx.lebail@yahoo.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

initialise pcpu_tstats.syncp to kill the calltrace
[   11.973950] Call Trace:
[   11.973950]  [<819bbaff>] dump_stack+0x48/0x60
[   11.973950]  [<819bbaff>] dump_stack+0x48/0x60
[   11.973950]  [<81078dcf>] __lock_acquire.isra.22+0x1bf/0xc10
[   11.973950]  [<81078dcf>] __lock_acquire.isra.22+0x1bf/0xc10
[   11.973950]  [<81079fa7>] lock_acquire+0x77/0xa0
[   11.973950]  [<81079fa7>] lock_acquire+0x77/0xa0
[   11.973950]  [<817ca7ab>] ? dev_get_stats+0xcb/0x130
[   11.973950]  [<817ca7ab>] ? dev_get_stats+0xcb/0x130
[   11.973950]  [<8183862d>] ip_tunnel_get_stats64+0x6d/0x230
[   11.973950]  [<8183862d>] ip_tunnel_get_stats64+0x6d/0x230
[   11.973950]  [<817ca7ab>] ? dev_get_stats+0xcb/0x130
[   11.973950]  [<817ca7ab>] ? dev_get_stats+0xcb/0x130
[   11.973950]  [<811cf8c1>] ? __nla_reserve+0x21/0xd0
[   11.973950]  [<811cf8c1>] ? __nla_reserve+0x21/0xd0
[   11.973950]  [<817ca7ab>] dev_get_stats+0xcb/0x130
[   11.973950]  [<817ca7ab>] dev_get_stats+0xcb/0x130
[   11.973950]  [<817d5409>] rtnl_fill_ifinfo+0x569/0xe20
[   11.973950]  [<817d5409>] rtnl_fill_ifinfo+0x569/0xe20
[   11.973950]  [<810352e0>] ? kvm_clock_read+0x20/0x30
[   11.973950]  [<810352e0>] ? kvm_clock_read+0x20/0x30
[   11.973950]  [<81008e38>] ? sched_clock+0x8/0x10
[   11.973950]  [<81008e38>] ? sched_clock+0x8/0x10
[   11.973950]  [<8106ba45>] ? sched_clock_local+0x25/0x170
[   11.973950]  [<8106ba45>] ? sched_clock_local+0x25/0x170
[   11.973950]  [<810da6bd>] ? __kmalloc+0x3d/0x90
[   11.973950]  [<810da6bd>] ? __kmalloc+0x3d/0x90
[   11.973950]  [<817b8c10>] ? __kmalloc_reserve.isra.41+0x20/0x70
[   11.973950]  [<817b8c10>] ? __kmalloc_reserve.isra.41+0x20/0x70
[   11.973950]  [<810da81a>] ? slob_alloc_node+0x2a/0x60
[   11.973950]  [<810da81a>] ? slob_alloc_node+0x2a/0x60
[   11.973950]  [<817b919a>] ? __alloc_skb+0x6a/0x2b0
[   11.973950]  [<817b919a>] ? __alloc_skb+0x6a/0x2b0
[   11.973950]  [<817d8795>] rtmsg_ifinfo+0x65/0xe0
[   11.973950]  [<817d8795>] rtmsg_ifinfo+0x65/0xe0
[   11.973950]  [<817cbd31>] register_netdevice+0x531/0x5a0
[   11.973950]  [<817cbd31>] register_netdevice+0x531/0x5a0
[   11.973950]  [<81892b87>] ? ip6_tnl_get_cap+0x27/0x90
[   11.973950]  [<81892b87>] ? ip6_tnl_get_cap+0x27/0x90
[   11.973950]  [<817cbdb6>] register_netdev+0x16/0x30
[   11.973950]  [<817cbdb6>] register_netdev+0x16/0x30
[   11.973950]  [<81f574a6>] vti6_init_net+0x1c4/0x1d4
[   11.973950]  [<81f574a6>] vti6_init_net+0x1c4/0x1d4
[   11.973950]  [<81f573af>] ? vti6_init_net+0xcd/0x1d4
[   11.973950]  [<81f573af>] ? vti6_init_net+0xcd/0x1d4
[   11.973950]  [<817c16df>] ops_init.constprop.11+0x17f/0x1c0
[   11.973950]  [<817c16df>] ops_init.constprop.11+0x17f/0x1c0
[   11.973950]  [<817c1779>] register_pernet_operations.isra.9+0x59/0x90
[   11.973950]  [<817c1779>] register_pernet_operations.isra.9+0x59/0x90
[   11.973950]  [<817c18d1>] register_pernet_device+0x21/0x60
[   11.973950]  [<817c18d1>] register_pernet_device+0x21/0x60
[   11.973950]  [<81f574b6>] ? vti6_init_net+0x1d4/0x1d4
[   11.973950]  [<81f574b6>] ? vti6_init_net+0x1d4/0x1d4
[   11.973950]  [<81f574c7>] vti6_tunnel_init+0x11/0x68
[   11.973950]  [<81f574c7>] vti6_tunnel_init+0x11/0x68
[   11.973950]  [<81f572a1>] ? mip6_init+0x73/0xb4
[   11.973950]  [<81f572a1>] ? mip6_init+0x73/0xb4
[   11.973950]  [<81f0cba4>] do_one_initcall+0xbb/0x15b
[   11.973950]  [<81f0cba4>] do_one_initcall+0xbb/0x15b
[   11.973950]  [<811a00d8>] ? sha_transform+0x528/0x1150
[   11.973950]  [<811a00d8>] ? sha_transform+0x528/0x1150
[   11.973950]  [<81f0c544>] ? repair_env_string+0x12/0x51
[   11.973950]  [<81f0c544>] ? repair_env_string+0x12/0x51
[   11.973950]  [<8105c30d>] ? parse_args+0x2ad/0x440
[   11.973950]  [<8105c30d>] ? parse_args+0x2ad/0x440
[   11.973950]  [<810546be>] ? __usermodehelper_set_disable_depth+0x3e/0x50
[   11.973950]  [<810546be>] ? __usermodehelper_set_disable_depth+0x3e/0x50
[   11.973950]  [<81f0cd27>] kernel_init_freeable+0xe3/0x182
[   11.973950]  [<81f0cd27>] kernel_init_freeable+0xe3/0x182
[   11.973950]  [<81f0c532>] ? do_early_param+0x7a/0x7a
[   11.973950]  [<81f0c532>] ? do_early_param+0x7a/0x7a
[   11.973950]  [<819b5b1b>] kernel_init+0xb/0x100
[   11.973950]  [<819b5b1b>] kernel_init+0xb/0x100
[   11.973950]  [<819cebf7>] ret_from_kernel_thread+0x1b/0x28
[   11.973950]  [<819cebf7>] ret_from_kernel_thread+0x1b/0x28
[   11.973950]  [<819b5b10>] ? rest_init+0xc0/0xc0
[   11.973950]  [<819b5b10>] ? rest_init+0xc0/0xc0

Before 469bdcef ("ipv6: fix the use of pcpu_tstats in ip6_vti.c"),
the pcpu_tstats.syncp is not used to pretect the 64bit elements of
pcpu_tstats, so not appear this calltrace.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It does not make sense to create an anycast address for an /128-prefix.
Suppress it.

As 32019e65 ("ipv6: Do not leave router anycast address for /127
prefixes.") shows we also may not leave them, because we could accidentally
remove an anycast address the user has allocated or got added via another
prefix.

Cc: François-Xavier Le Bail <fx.lebail@yahoo.com>
Cc: Thomas Haller <thaller@redhat.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

They are same, so unify them as one, pcpu_sw_netstats.

Define pcpu_sw_netstat in netdevice.h, remove pcpu_tstats
from if_tunnel and remove br_cpu_netstats from br_private.h

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when read/write the 64bit data, the correct lock should be hold.
and we can use the generic vti6_get_stats to return stats, and
not define a new one in ip6_vti.c

Fixes: 87b6d218 ("tunnel: implement 64 bits statistics")
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when read/write the 64bit data, the correct lock should be hold.

Fixes: 87b6d218 ("tunnel: implement 64 bits statistics")

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixed a problem with setting the lifetime of an IPv6
address. When setting preferred_lft to a value not zero or
infinity, while valid_lft is infinity(0xffffffff) preferred
lifetime is set to forever and does not update. Therefore
preferred lifetime never becomes deprecated. valid lifetime
and preferred lifetime should be set independently, even if
valid lifetime is infinity, preferred lifetime must expire
correctly (meaning it must eventually become deprecated)
Signed-off-by: NYasushi Asano <yasushi.asano@jp.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

since the prune parameter for fib6_clean_all always is 0, remove it.
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>

Running 'make namespacecheck' shows:
  net/ipv6/route.o
    ipv6_route_table_template
    rt6_bind_peer
  net/ipv6/icmp.o
    icmpv6_route_lookup
    ipv6_icmp_table_template

This addresses some of those warnings by:
 * make icmpv6_route_lookup static
 * move inline's out of ip6_route.h since only used into route.c
 * move rt6_bind_peer into route.c
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function __rtnl_af_register is never called outside this
code, and the return value is always 0.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when read/write the 64bit data, the correct lock should be hold.
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Since addrconf_get_prefix_route inputs the address prefix to fib6_locate,
which does not uses the data which is out of the prefix_len length,
so do not need to use ipv6_addr_prefix to get address prefix.
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 patch prepares the addition of TCP reset support in
the nft_reject module by moving reusable code into a header
file.
Signed-off-by: NEric Leblond <eric@regit.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

if a dst is not attached to anywhere, it should be released before
exit ipip6_tunnel_xmit, otherwise cause dst memory leakage.

Fixes: 61c1db7f ("ipv6: sit: add GSO/TSO support")
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix some checkpatch errors for tcp_ipv6.c
Signed-off-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to be able to see changes to proxy NDP status on a per
interface basis via netlink (analog to proxy_arp).
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip6_rt_copy only sets dst.from if ort has flag RTF_ADDRCONF and RTF_DEFAULT.
but the prefix routes which did get installed by hand locally can have an
expiration, and no any flag combination which can ensure a potential from
does never expire, so we should always set the new created dst's from.

This also fixes the new created dst is always expired since the ort, which
is created by RA, maybe has RTF_EXPIRES and RTF_ADDRCONF, but no RTF_DEFAULT.
Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
CC: Gao feng <gaofeng@cn.fujitsu.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>

While testing my changes for TSO support in SIT devices,
I was using sit0 tunnel which appears to include nopmtudisc flag.

But using :

ip tun add sittun mode sit remote $REMOTE_IPV4 local $LOCAL_IPV4 \
   dev $IFACE

We get a tunnel which rejects too long packets because of the mtu check
which is not yet GSO aware.

erd:~# ip tunnel
sittun: ipv6/ip  remote 10.246.17.84  local 10.246.17.83  ttl inherit  6rd-prefix 2002::/16
sit0: ipv6/ip  remote any  local any  ttl 64  nopmtudisc 6rd-prefix 2002::/16

This patch is based on an excellent report from
Michal Shmidt.

In the future, we probably want to extend the MTU check to do the
right thing for GSO packets...

Fixes: ("61c1db7f ipv6: sit: add GSO/TSO support")
Reported-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sockets marked with IPV6_PMTUDISC_PROBE (or later IPV6_PMTUDISC_INTERFACE)
don't respect this setting when the outgoing interface supports UFO.

We had the same problem in IPv4, which was fixed in commit
daba287b ("ipv4: fix DO and PROBE pmtu
mode regarding local fragmentation with UFO/CORK").

Also IPV6_DONTFRAG mode did not care about already corked data, thus
it may generate a fragmented frame even if this socket option was
specified. It also did not care about the length of the ipv6 header and
possible options.

In the error path allow the user to receive the pmtu notifications via
both, rxpmtu method or error queue. The user may opted in for both,
so deliver the notification to both error handlers (the handlers check
if the error needs to be enqueued).

Also report back consistent pmtu values when sending on an already
cork-appended socket.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it
nontheless for symmetry with IPv4 sockets. Also drop incoming MTU
information if this mode is enabled.

The additional bit in ipv6_pinfo just eats in the padding behind the
bitfield. There are no changes to the layout of the struct at all.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The other field in ipv4_config, log_martians, was converted to a
per-interface setting, so we can just remove the whole structure.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It was reported that Commit 299603e8
("net-gro: Prepare GRO stack for the upcoming tunneling support")
triggered a compiler warning in ipv6_exthdrs_len():

net/ipv6/ip6_offload.c: In function ‘ipv6_gro_complete’:
net/ipv6/ip6_offload.c:178:24: warning: ‘optlen’ may be used uninitialized in this function [-Wmaybe-u
    opth = (void *)opth + optlen;
    			^
    net/ipv6/ip6_offload.c:164:22: note: ‘optlen’ was declared here
    int len = 0, proto, optlen;
                        ^
Note that there was no real bug here - optlen was never uninitialized
before use. (Was the version of gcc I used smarter to not complain?)
Reported-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 299603e8 ("net-gro: Prepare GRO
stack for the upcoming tunneling support") used an uninitialized variable
which leads to the following compiler warning:

net/ipv6/ip6_offload.c: In function ‘ipv6_gro_complete’:
net/ipv6/ip6_offload.c:178:24: warning: ‘optlen’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    opth = (void *)opth + optlen;
                        ^
net/ipv6/ip6_offload.c:164:22: note: ‘optlen’ was declared here
  int len = 0, proto, optlen;
                      ^
Fix it up.

Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>