It's just taking on one of two possible values, either
neigh_ops->output or dev_queue_xmit().  And this is purely depending
upon whether nud_state has NUD_CONNECTED set or not.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that there is a one-to-one correspondance between neighbour
and hh_cache entries, we no longer need:

1) dynamic allocation
2) attachment to dst->hh
3) refcounting

Initialization of the hh_cache entry is indicated by hh_len
being non-zero, and such initialization is always done with
the neighbour's lock held as a writer.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of all of the useless and costly indirection
by doing the neigh hash table lookup directly inside
of the neighbour binding.

Rename from arp_bind_neighbour to rt_bind_neighbour.

Use new helpers {__,}ipv4_neigh_lookup()

In rt_bind_neighbour() get rid of useless tests which
are never true in the context this function is called,
namely dev is never NULL and the dst->neighbour is
always NULL.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the case labels the same indent as the switch.

git diff -w shows no difference.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Knut Tidemann found that first packet of a multicast flow was not
correctly received, and bisected the regression to commit b23dd4fe
(Make output route lookup return rtable directly.)

Special thanks to Knut, who provided a very nice bug report, including
sample programs to demonstrate the bug.

Reported-and-bisectedby: Knut Tidemann <knut.andre.tidemann@jotron.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.
Signed-off-by: NGreg Rose <gregory.v.rose@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

commit 2c8cec5c (ipv4: Cache learned PMTU information in inetpeer)
added some racy peer->pmtu_expires accesses.

As its value can be changed by another cpu/thread, we should be more
careful, reading its value once.

Add peer_pmtu_expired() and peer_pmtu_cleaned() helpers
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a stack backtrace to the ip_rt_bug path for debugging
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

It's way past it's usefulness.  And this gets rid of a bunch
of stray ->rt_{dst,src} references.

Even the comment documenting the macro was inaccurate (stated
default was 1 when it's 0).

If reintroduced, it should be done properly, with dynamic debug
facilities.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At these points we have a fully filled in value via the IP
header the form of ip_hdr(skb)->saddr
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass in the sk_buff so that we can fetch the necessary keys from
the packet header when working with input routes.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This eliminates the need to use rt->rt_{src,dst}.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To more accurately reflect that it is purely a routing
cache lookup key and is used in no other context.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Slow path output route resolution always makes sure that
->{saddr,daddr} are set, and also if we trigger into IPSEC resolution
we initialize them as well, because xfrm_lookup() expects them to be
fully resolved.

But if we hit the fast path and flowi4->flowi4_proto is zero, we won't
do this initialization.

Therefore, move the IPSEC path initialization to the route cache
lookup fast path to make sure these are always set.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Make dst_alloc() and it's users explicitly initialize the entire
entry.

The zero'ing done by kmem_cache_zalloc() was almost entirely
redundant.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now the dst->dev, dev->obsolete, and dst->flags values can
be specified as well.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 62fa8a84 (net: Implement read-only protection and COW'ing
of metrics.) the kernel throws an oops.

[  101.620985] BUG: unable to handle kernel NULL pointer dereference at
           (null)
[  101.621050] IP: [<          (null)>]           (null)
[  101.621084] PGD 6e53c067 PUD 3dd6a067 PMD 0
[  101.621122] Oops: 0010 [#1] SMP
[  101.621153] last sysfs file: /sys/devices/virtual/ppp/ppp/uevent
[  101.621192] CPU 2
[  101.621206] Modules linked in: l2tp_ppp pppox ppp_generic slhc
l2tp_netlink l2tp_core deflate zlib_deflate twofish_x86_64
twofish_common des_generic cbc ecb sha1_generic hmac af_key
iptable_filter snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device loop
snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec
snd_pcm snd_timer snd i2c_i801 iTCO_wdt psmouse soundcore snd_page_alloc
evdev uhci_hcd ehci_hcd thermal
[  101.621552]
[  101.621567] Pid: 5129, comm: openl2tpd Not tainted 2.6.39-rc4-Quad #3
Gigabyte Technology Co., Ltd. G33-DS3R/G33-DS3R
[  101.621637] RIP: 0010:[<0000000000000000>]  [<          (null)>]   (null)
[  101.621684] RSP: 0018:ffff88003ddeba60  EFLAGS: 00010202
[  101.621716] RAX: ffff88003ddb5600 RBX: ffff88003ddb5600 RCX:
0000000000000020
[  101.621758] RDX: ffffffff81a69a00 RSI: ffffffff81b7ee61 RDI:
ffff88003ddb5600
[  101.621800] RBP: ffff8800537cd900 R08: 0000000000000000 R09:
ffff88003ddb5600
[  101.621840] R10: 0000000000000005 R11: 0000000000014b38 R12:
ffff88003ddb5600
[  101.621881] R13: ffffffff81b7e480 R14: ffffffff81b7e8b8 R15:
ffff88003ddebad8
[  101.621924] FS:  00007f06e4182700(0000) GS:ffff88007fd00000(0000)
knlGS:0000000000000000
[  101.621971] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  101.622005] CR2: 0000000000000000 CR3: 0000000045274000 CR4:
00000000000006e0
[  101.622046] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  101.622087] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  101.622129] Process openl2tpd (pid: 5129, threadinfo
ffff88003ddea000, task ffff88003de9a280)
[  101.622177] Stack:
[  101.622191]  ffffffff81447efa ffff88007d3ded80 ffff88003de9a280
ffff88007d3ded80
[  101.622245]  0000000000000001 ffff88003ddebbb8 ffffffff8148d5a7
0000000000000212
[  101.622299]  ffff88003dcea000 ffff88003dcea188 ffffffff00000001
ffffffff81b7e480
[  101.622353] Call Trace:
[  101.622374]  [<ffffffff81447efa>] ? ipv4_blackhole_route+0x1ba/0x210
[  101.622415]  [<ffffffff8148d5a7>] ? xfrm_lookup+0x417/0x510
[  101.622450]  [<ffffffff8127672a>] ? extract_buf+0x9a/0x140
[  101.622485]  [<ffffffff8144c6a0>] ? __ip_flush_pending_frames+0x70/0x70
[  101.622526]  [<ffffffff8146fbbf>] ? udp_sendmsg+0x62f/0x810
[  101.622562]  [<ffffffff813f98a6>] ? sock_sendmsg+0x116/0x130
[  101.622599]  [<ffffffff8109df58>] ? find_get_page+0x18/0x90
[  101.622633]  [<ffffffff8109fd6a>] ? filemap_fault+0x12a/0x4b0
[  101.622668]  [<ffffffff813fb5c4>] ? move_addr_to_kernel+0x64/0x90
[  101.622706]  [<ffffffff81405d5a>] ? verify_iovec+0x7a/0xf0
[  101.622739]  [<ffffffff813fc772>] ? sys_sendmsg+0x292/0x420
[  101.622774]  [<ffffffff810b994a>] ? handle_pte_fault+0x8a/0x7c0
[  101.622810]  [<ffffffff810b76fe>] ? __pte_alloc+0xae/0x130
[  101.622844]  [<ffffffff810ba2f8>] ? handle_mm_fault+0x138/0x380
[  101.622880]  [<ffffffff81024af9>] ? do_page_fault+0x189/0x410
[  101.622915]  [<ffffffff813fbe03>] ? sys_getsockname+0xf3/0x110
[  101.622952]  [<ffffffff81450c4d>] ? ip_setsockopt+0x4d/0xa0
[  101.622986]  [<ffffffff813f9932>] ? sockfd_lookup_light+0x22/0x90
[  101.623024]  [<ffffffff814b61fb>] ? system_call_fastpath+0x16/0x1b
[  101.623060] Code:  Bad RIP value.
[  101.623090] RIP  [<          (null)>]           (null)
[  101.623125]  RSP <ffff88003ddeba60>
[  101.623146] CR2: 0000000000000000
[  101.650871] ---[ end trace ca3856a7d8e8dad4 ]---
[  101.651011] __sk_free: optmem leakage (160 bytes) detected.

The oops happens in dst_metrics_write_ptr()
include/net/dst.h:124: return dst->ops->cow_metrics(dst, p);

dst->ops->cow_metrics is NULL and causes the oops.

Provide cow_metrics() methods, like we did in commit 214f45c9
(net: provide default_advmss() methods to blackhole dst_ops)
Signed-off-by: NHeld Bernhard <berny156@gmx.de>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_select_default() is a complete NOP, and completely pointless
to invoke, when we have no more than 1 default route installed.

And this is far and away the common case.

So remember how many prefixlen==0 routes we have in the routing
table, and elide the call when we have no more than one of those.

This cuts output route creation time by 157 cycles on Niagara2+.

In order to add the new int to fib_table, we have to correct the type
of ->tb_data[] to unsigned long, otherwise the private area will be
unaligned on 64-bit systems.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>

This makes sk_buff available for other use in fib_validate_source().
Signed-off-by: NMichael Smith <msmith@cbnco.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 1018b5c0 ("Set rt->rt_iif more
sanely on output routes.")  breaks rt_is_{output,input}_route.

This became the cause to return "IP_PKTINFO's ->ipi_ifindex == 0".

To fix it, this does:

1) Add "int rt_route_iif;" to struct rtable

2) For input routes, always set rt_route_iif to same value as rt_iif

3) For output routes, always set rt_route_iif to zero.  Set rt_iif
   as it is done currently.

4) Change rt_is_{output,input}_route() to test rt_route_iif
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Any operation that:

1) Brings up an interface
2) Adds an IP address to an interface
3) Deletes an IP address from an interface

can potentially invalidate the nh_saddr value, requiring
it to be recomputed.

Perform the recomputation lazily using a generation ID.
Reported-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 2c8cec5c (Cache learned PMTU information in inetpeer) added
an extra inet_putpeer() call in ip_rt_update_pmtu().

This results in various problems, since we can free one inetpeer, while
it is still in use.

Ref: http://www.spinics.net/lists/netdev/msg159121.htmlReported-by: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ECN support incorrectly maps ECN BESTEFFORT packets to TC_PRIO_FILLER
(1) instead of TC_PRIO_BESTEFFORT (0)

This means ECN enabled flows are placed in pfifo_fast/prio low priority
band, giving ECN enabled flows [ECT(0) and CE codepoints] higher drop
probabilities.

This is rather unfortunate, given we would like ECN being more widely
used.

Ref : http://www.coverfire.com/archives/2011/03/13/pfifo_fast-and-ecn/Signed-off-by: NDan Siemon <dan@coverfire.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Täht <d@taht.net>
Cc: Jonathan Morton <chromatix99@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),

  icmp_unreach
    -> ip_rt_frag_needed
         (peer->pmtu_expires is set here)
    -> tcp_v4_err
         -> do_pmtu_discovery
              -> ip_rt_update_pmtu
                   (peer->pmtu_expires is already set,
                    so check_peer_pmtu is skipped.)
                   -> check_peer_pmtu

check_peer_pmtu is skipped and MTU is not updated.

To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
   but not initialized.
Signed-off-by: NHiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

We will change the externally visible APIs next.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To start doing these conversions, we need to add some temporary
flow4_* macros which will eventually go away when all the protocol
code paths are changed to work on AF specific flowi objects.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

fl->oif will always be zero on the input path, so there is no reason
to test for that.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All callers are under rcu_read_lock() protection already.

Rename to ip_check_mc_rcu() to make it even more clear.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like in commit 44713b67
("ipv4: Optimize flow initialization in output route lookup."
we can optimize the on-stack flow setup to only initialize
the members which are actually used.

Otherwise we bzero the entire structure, then initialize
explicitly the first half of it.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The only necessary parts are the src/dst addresses, the
interface indexes, the TOS, and the mark.

The rest is unnecessary bloat, which amounts to nearly
50 bytes on 64-bit.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rt->rt_iif is only ever inspected on input routes, for example DCCP
uses this to populate a route lookup flow key when generating replies
to another packet.

Therefore, setting it to anything other than zero on output routes
makes no sense.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We know this is a new route object, so doing atomics and
stuff makes no sense at all.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We burn a lot of useless cycles, cpu store buffer traffic, and
memory operations memset()'ing the on-stack flow used to perform
output route lookups in __ip_route_output_key().

Only the first half of the flow object members even matter for
output route lookups in this context, specifically:

FIB rules matching cares about:

	dst, src, tos, iif, oif, mark

FIB trie lookup cares about:

	dst

FIB semantic match cares about:

	tos, scope, oif

Therefore only initialize these specific members and elide the
memset entirely.

On Niagara2 this kills about ~300 cycles from the output route
lookup path.

Likely, we can take things further, since all callers of output
route lookups essentially throw away the on-stack flow they use.
So they don't care if we use it as a scratch-pad to compute the
final flow key.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>