When testing GRE tunnel, I got:

 # ip tunnel show
 get tunnel gre0 failed: Invalid argument
 get tunnel gre1 failed: Invalid argument

This is a regression introduced by commit c5441932
("GRE: Refactor GRE tunneling code.") because previously we
only check the parameters for SIOCADDTUNNEL and SIOCCHGTUNNEL,
after that commit, the check is moved for all commands.

So, just check for SIOCADDTUNNEL and SIOCCHGTUNNEL.

After this patch I got:

 # ip tunnel show
 gre0: gre/ip  remote any  local any  ttl inherit  nopmtudisc
 gre1: gre/ip  remote 192.168.122.101  local 192.168.122.45  ttl inherit

Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit d2d68ba9 (ipv4: Cache input routes in fib_info nexthops)
assmued that "locally destined, and routed packets, never trigger
PMTU events or redirects that will be processed by us".

However, it seems that tunnel devices do trigger PMTU events in certain
cases. At least ip_gre, ip6_gre, sit, and ipip do use the inner flow's
skb_dst(skb)->ops->update_pmtu to propage mtu information from the
outer flows. These can cause the inner flow mtu to be decreased. If
next hop exceptions are not consulted for pmtu, IP fragmentation will
not be done properly for these routes.

It also seems that we really need to have the PMTU information always
for netfilter TCPMSS clamp-to-pmtu feature to work properly.

So for the time being, cache separate copies of input routes for
each next hop exception.
Signed-off-by: NTimo Teräs <timo.teras@iki.fi>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since (c05cdb1b netlink: allow large data transfers from user-space),
netlink splats if it invokes skb_clone on large netlink skbs since:

* skb_shared_info was not correctly initialized.
* skb->destructor is not set in the cloned skb.

This was spotted by trinity:

[  894.990671] BUG: unable to handle kernel paging request at ffffc9000047b001
[  894.991034] IP: [<ffffffff81a212c4>] skb_clone+0x24/0xc0
[...]
[  894.991034] Call Trace:
[  894.991034]  [<ffffffff81ad299a>] nl_fib_input+0x6a/0x240
[  894.991034]  [<ffffffff81c3b7e6>] ? _raw_read_unlock+0x26/0x40
[  894.991034]  [<ffffffff81a5f189>] netlink_unicast+0x169/0x1e0
[  894.991034]  [<ffffffff81a601e1>] netlink_sendmsg+0x251/0x3d0

Fix it by:

1) introducing a new netlink_skb_clone function that is used in nl_fib_input,
   that sets our special skb->destructor in the cloned skb. Moreover, handle
   the release of the large cloned skb head area in the destructor path.

2) not allowing large skbuffs in the netlink broadcast path. I cannot find
   any reasonable use of the large data transfer using netlink in that path,
   moreover this helps to skip extra skb_clone handling.

I found two more netlink clients that are cloning the skbs, but they are
not in the sendmsg path. Therefore, the sole client cloning that I found
seems to be the fib frontend.

Thanks to Eric Dumazet for helping to address this issue.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch allows to switch the netns when packet is encapsulated or
decapsulated. In other word, the encapsulated packet is received in a netns,
where the lookup is done to find the tunnel. Once the tunnel is found, the
packet is decapsulated and injecting into the corresponding interface which
stands to another netns.

When one of the two netns is removed, the tunnel is destroyed.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 32b8a8e5 "sit: add IPv4 over IPv4 support",
tunnel->parms.iph.protocol is 0 when both 4in4 and 6in4 are setup, but
xfrm_lookup() is called only when proto is != 0, thus we need to pass the real
value.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes an empty ifdef from inet_frag_intern()
in net/ipv4/inet_fragment.c.

commit b67bfe0d
(hlist: drop the node parameter from iterators) removed hlist from
net/ipv4/inet_fragment.c, but did not remove the enclosing ifdef command,
which is now empty.
Signed-off-by: NRami Rosen <ramirose@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In previous discussions, I tried to find some reasonable heuristics
for delayed ACK, however this seems not possible, according to Eric:

	"ACKS might also be delayed because of bidirectional
	traffic, and is more controlled by the application
	response time. TCP stack can not easily estimate it."

	"ACK can be incredibly useful to recover from losses in
	a short time.

	The vast majority of TCP sessions are small lived, and we
	send one ACK per received segment anyway at beginning or
	retransmits to let the sender smoothly increase its cwnd,
	so an auto-tuning facility wont help them that much."

and according to David:

	"ACKs are the only information we have to detect loss.

	And, for the same reasons that TCP VEGAS is fundamentally
	broken, we cannot measure the pipe or some other
	receiver-side-visible piece of information to determine
	when it's "safe" to stretch ACK.

	And even if it's "safe", we should not do it so that losses are
	accurately detected and we don't spuriously retransmit.

	The only way to know when the bandwidth increases is to
	"test" it, by sending more and more packets until drops happen.
	That's why all successful congestion control algorithms must
	operate on explicited tested pieces of information.

	Similarly, it's not really possible to universally know if
	it's safe to stretch ACK or not."

It still makes sense to enable or disable quick ack mode like
what TCP_QUICK_ACK does.

Similar to TCP_QUICK_ACK option, but for people who can't
modify the source code and still wants to control
TCP delayed ACK behavior. As David suggested, this should belong
to per-path scope, since different pathes may want different
behaviors.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Rick Jones <rick.jones2@hp.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
CC: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NWeiping Pan <wpan@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Process skb tunnel header before sending packet to protocol handler.
this allows code sharing between gre and ovs gre modules.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor various ip tunnels xmit functions and extend iptunnel_xmit()
so that there is more code sharing.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is required for OVS GRE offloading.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is required for ovs gre module.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there is only one user is allowed to register for gre
protocol.  Following patch adds de-multiplexer.  So that multiple
modules can listen on gre protocol e.g. kernel gre devices and ovs.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use cmpxchg() for atomic protocol registration which saves
code and data space.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If CONFIG_NET_NS is not set then __net_init is the same as __init and
__net_exit is the same as __exit. These functions will be removed from
memory after the module loads or is removed. Functions that are exported
for use by other functions should never be labeled for removal.

Bug introduced by commit c5441932
("GRE: Refactor GRE tunneling code.")
Reported-by: NSteinar H. Gunderson <sgunderson@bigfoot.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If users apply shaper to vti tunnel then it will cause a kernel crash. The
problem seems to be due to the vti_tunnel_xmit function not clearing
skb->opt field before passing the packet to xfrm tunneling code.
Signed-off-by: NSaurabh Mohan <saurabh@vyatta.com>
Acked-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Linux sends new unset data during disorder and recovery state if all
(suspected) lost packets have been retransmitted ( RFC5681, section
3.2 step 1 & 2, RFC3517 section 4, NexSeg() Rule 2).  One requirement
is to keep the receive window about twice the estimated sender's
congestion window (tcp_rcv_space_adjust()), assuming the fast
retransmits repair the losses in the next round trip.

But currently it's not the case on the first round trip in either
normal or Fast Open connection, beucase the initial receive window
is identical to (expected) sender's initial congestion window. The
fix is to double it.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reduce the uses of this unnecessary typedef.

Done via perl script:

$ git grep --name-only -w ctl_table net | \
  xargs perl -p -i -e '\
	sub trim { my ($local) = @_; $local =~ s/(^\s+|\s+$)//g; return $local; } \
        s/\b(?<!struct\s)ctl_table\b(\s*\*\s*|\s+\w+)/"struct ctl_table " . trim($1)/ge'

Reflow the modified lines that now exceed 80 columns.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ping.c:286:5: sparse: symbol 'ping_check_bind_addr' was not declared. Should it be static?
net/ipv4/ping.c:355:6: sparse: symbol 'ping_set_saddr' was not declared. Should it be static?
net/ipv4/ping.c:370:6: sparse: symbol 'ping_clear_saddr' was not declared. Should it be static?

net/ipv6/ping.c:60:5: sparse: symbol 'dummy_ipv6_recv_error' was not declared. Should it be static?
net/ipv6/ping.c:64:5: sparse: symbol 'dummy_ip6_datagram_recv_ctl' was not declared. Should it be static?
net/ipv6/ping.c:69:5: sparse: symbol 'dummy_icmpv6_err_convert' was not declared. Should it be static?
net/ipv6/ping.c:73:6: sparse: symbol 'dummy_ipv6_icmp_error' was not declared. Should it be static?
net/ipv6/ping.c:75:5: sparse: symbol 'dummy_ipv6_chk_addr' was not declared. Should it be static?
net/ipv6/ping.c:201:5: sparse: symbol 'ping_v6_seq_show' was not declared. Should it be static?
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit ba418fa3 ("soreuseport: UDP/IPv4 implementation")
added following sparse errors :

net/ipv4/udp.c:433:60: warning: cast from restricted __be16
net/ipv4/udp.c:433:60: warning: incorrect type in argument 1 (different base types)
net/ipv4/udp.c:433:60:    expected unsigned short [unsigned] [usertype] val
net/ipv4/udp.c:433:60:    got restricted __be16 [usertype] sport
net/ipv4/udp.c:433:60: warning: cast from restricted __be16
net/ipv4/udp.c:433:60: warning: cast from restricted __be16
net/ipv4/udp.c:514:60: warning: cast from restricted __be16
net/ipv4/udp.c:514:60: warning: incorrect type in argument 1 (different base types)
net/ipv4/udp.c:514:60:    expected unsigned short [unsigned] [usertype] val
net/ipv4/udp.c:514:60:    got restricted __be16 [usertype] sport
net/ipv4/udp.c:514:60: warning: cast from restricted __be16
net/ipv4/udp.c:514:60: warning: cast from restricted __be16
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix following sparse error :

net/ipv4/af_inet.c:1410:59: warning: restricted __be16 degrades to
integer

added in commit db8caf3d
("gro: should aggregate frames without DF")
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
From: Eric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix following sparse errors :

net/ipv4/igmp.c:1222:25: warning: cast from restricted __be32
net/ipv4/igmp.c:1234:31: warning: incorrect type in assignment (different address spaces)
net/ipv4/igmp.c:1234:31:    expected struct ip_mc_list [noderef] <asn:4>*next_hash
net/ipv4/igmp.c:1234:31:    got struct ip_mc_list *<noident>
net/ipv4/igmp.c:1250:31: warning: incorrect type in assignment (different address spaces)
net/ipv4/igmp.c:1250:31:    expected struct ip_mc_list [noderef] <asn:4>*next_hash
net/ipv4/igmp.c:1250:31:    got struct ip_mc_list *<noident>
net/ipv4/igmp.c:2380:37: warning: cast from restricted __be32

These were added by commit e9897071
("igmp: hash a hash table to speedup ip_check_mc_rcu()")
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similarly to TCP offloading and UDPv6 offloading, move all related
UDPv4 functions to udp_offload.c to make things more explicit. Also,
by this, we can make those functions static.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_mc_init_dev() is passed a freshly kzalloc'd in_device so it is
unnecessary to explicitly zero out the members.
Signed-off-by: NShawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After IP route cache removal, multicast applications using
a lot of multicast addresses hit a O(N) behavior in ip_check_mc_rcu()

Add a per in_device hash table to get faster lookup.

This hash table is created only if the number of items in mc_list is
above 4.
Reported-by: NShawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Tested-by: NShawn Bohrer <sbohrer@rgmadvisors.com>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to the following commits:

commit 00f97da1 (netpoll: fix position of network header)
commit 525cebed (pktgen: Fix position of ip and udp header)

using skb_tail_offset() seems not correct since the offset
is based on head pointer.

With the last caller removed, skb_tail_offset() can be killed
finally.

Cc: Thomas Graf <tgraf@suug.ch>
Cc: Daniel Borkmann <dborkmann@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds low latency socket poll support for TCP.
In tcp_v[46]_rcv() add a call to sk_mark_ll() to copy the napi_id
from the skb to the sk.
In tcp_recvmsg(), when there is no data in the socket we busy-poll.
This is a good example of how to add busy-poll support to more protocols.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NEliezer Tamir <eliezer.tamir@linux.intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Tested-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add upport for busy-polling on UDP sockets.
In __udp[46]_lib_rcv add a call to sk_mark_ll() to copy the napi_id
from the skb into the sk.
This is done at the earliest possible moment, right after we identify
which socket this skb is for.
In __skb_recv_datagram When there is no data and the user
tries to read we busy poll.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NEliezer Tamir <eliezer.tamir@linux.intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Tested-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds an ndo_ll_poll method and the code that supports it.
This method can be used by low latency applications to busy-poll
Ethernet device queues directly from the socket code.
sysctl_net_ll_poll controls how many microseconds to poll.
Default is zero (disabled).
Individual protocol support will be added by subsequent patches.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NEliezer Tamir <eliezer.tamir@linux.intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Tested-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Would be good to make things explicit and move those functions to
a new file called tcp_offload.c, thus make this similar to tcpv6_offload.c.
While moving all related functions into tcp_offload.c, we can also
make some of them static, since they are only used there. Also, add
an explicit registration function.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have the minimal inline helper tcp_skb_mss to access
skb_shinfo(skb)->gso_size, so also use it here to get mss.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we don't need scope id, we should initialize it to zero.
Same for ->sin6_flowinfo.

Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Acked-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 202dc3fc (Documentation: remove
obsolete networking/multicast.txt file) deleted the obsolete file. After
the file has been removed, clean up a couple of places where references
to the deleted file were made so that users wouldn't be confused when
they consult the Help menu.
Signed-off-by: NJean Sacren <sakiwit@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The format is based on /proc/net/icmp and /proc/net/{udp,raw}6.

Compiles and displays reasonable results with CONFIG_IPV6={n,m,y}
Couldn't figure out how to test without CONFIG_PROC_FS enabled.
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a ping_seq_afinfo structure (similar to its UDP
equivalent) and use it to make some of the ping /proc functions
address-family independent. Rename the remaining ping /proc
functions from ping_* to ping_v4_*.

Compiles and displays reasonable results with CONFIG_IPV6={n,m,y}
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct icmp_bxm is a large struct, reduce stack usage
by allocating it on heap.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ICMP_PARAMETERPROB is handled by icmp_unreach(); This patch adds
ICMP_PARAMETERPROB to the list of ICMP message types handled by icmp_unreach().
Signed-off-by: NRami Rosen <ramirose@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 13d82bf5 (ipv4: Fix flushing of cached routing informations)
added the support to flush learned pmtu information.

However, using rt_genid is quite heavy as it is bumped on route
add/change and multicast events amongst other places. These can
happen quite often, especially if using dynamic routing protocols.

While this is ok with routes (as they are just recreated locally),
the pmtu information is learned from remote systems and the icmp
notification can come with long delays. It is worthy to have separate
genid to avoid excessive pmtu resets.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NTimo Teräs <timo.teras@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tunnel devices call update_pmtu for each packet sent, this causes
contention on the fnhe_lock. Ignore the pmtu update if pmtu is not
actually changed, and there is still plenty of time before the entry
expires.
Signed-off-by: NTimo Teräs <timo.teras@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 05ab86c5 (xfrm4: Invalidate all ipv4 routes on
IPsec pmtu events). Flushing all cached entries is not needed.

Instead, invalidate only the related next hop dsts to recheck for
the added next hop exception where needed. This also fixes a subtle
race due to bumping generation id's before updating the pmtu.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NTimo Teräs <timo.teras@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>