During some debugging I needed to look into how /proc/net/ipv6_route
operated and in my digging I found its calling fib6_clean_all() which uses
"write_lock_bh(&table->tb6_lock)" before doing the walk of the table. I
found this on 2.6.32, but reading the code I believe the same basic idea
exists currently. Looking at the rtnetlink code they are only calling
"read_lock_bh(&table->tb6_lock);" via fib6_dump_table(). While I realize
reading from proc isn't the recommended way of fetching the ipv6 route
table; taking a write lock seems unnecessary and would probably cause
network performance issues.

To verify this I loaded up the ipv6 route table and then ran iperf in 3
cases:
  * doing nothing
  * reading ipv6 route table via proc
    (while :; do cat /proc/net/ipv6_route > /dev/null; done)
  * reading ipv6 route table via rtnetlink
    (while :; do ip -6 route show table all > /dev/null; done)

* Load the ipv6 route table up with:
  * for ((i = 0;i < 4000;i++)); do ip route add unreachable 2000::$i; done

* iperf commands:
  * client: iperf -i 1 -V -c <ipv6 addr>
  * server: iperf -V -s

* iperf results - 3 runs each (in Mbits/sec)
  * nothing: client: 927,927,927 server: 927,927,927
  * proc: client: 179,97,96,113 server: 142,112,133
  * iproute: client: 928,927,928 server: 927,927,927

lock_stat shows taking the write lock is causing the slowdown. Using this
info I decided to write a version of fib6_clean_all() which replaces
write_lock_bh(&table->tb6_lock) with read_lock_bh(&table->tb6_lock). With
this new function I see the same results as with my rtnetlink iperf test.
Signed-off-by: NJosh Hunt <joshhunt00@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In some of the rt6_bind_neighbour() call sites, it hasn't hooked
up the rt->dst.dev pointer yet, so we'd deref a NULL pointer when
obtaining dev->ifindex for the neighbour hash function computation.

Just pass the netdevice explicitly in to fix this problem.
Reported-by: NBjarke Istrup Pedersen <gurligebis@gentoo.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I missed this while adding ipv6 support to inet_peer.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It just obscures that the netdevice pointer and the expires value are
implemented in the dst_entry sub-object of the ipv6 route.

And it makes grepping for dst_entry member uses much harder too.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also, create and use an rt6_bind_neighbour() in net/ipv6/route.c to
consolidate some common logic.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RDBG() wasn't even used, and the messages printed by RT6_DEBUG() were
far from useful.  Just get rid of all this stuff, we can replace it
with something more suitable if we want.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After commit 8e2ec639 ("ipv6: don't
use inetpeer to store metrics for routes.") the test in rt6_alloc_cow()
for setting the ANYCAST flag is now wrong.

'rt' will always now have a plen of 128, because it is set explicitly
to 128 by ip6_rt_copy.

So to restore the semantics of the test, check the destination prefix
length of 'ort'.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't just succeed with a route that has a NULL neighbour attached.
This follows the behavior of addrconf_dst_alloc().

Allowing this kind of route to end up with a NULL neigh attached will
result in packet drops on output until the route is somehow
invalidated, since nothing will meanwhile try to lookup the neigh
again.

A statistic is bumped for the case where we see a neigh-less route on
output, but the resulting packet drop is otherwise silent in nature,
and frankly it's a hard error for this to happen and ipv6 should do
what ipv4 does which is say something in the kernel logs.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And return error pointers.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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>

like rt6_lookup, but allows caller to pass in flowi6 structure.
Will be used by the upcoming ipv6 netfilter reverse path filter
match.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

It's only used in net/ipv6/route.c and the NULL device check is
superfluous for all of the existing call sites.

Just expand the __ndisc_lookup_errno() call at each location.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) x == NULL --> !x
2) x != NULL --> x
3) (x&BIT) --> (x & BIT)
4) (BIT1|BIT2) --> (BIT1 | BIT2)
5) proper argument and struct member alignment
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We move all mtu handling from dst_mtu() down to the protocol
layer. So each protocol can implement the mtu handling in
a different manner.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We plan to invoke the dst_opt->default_mtu() method unconditioally
from dst_mtu(). So rename the method to dst_opt->mtu() to match
the name with the new meaning.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it is, we return null as the default mtu of blackhole routes.
This may lead to a propagation of a bogus pmtu if the default_mtu
method of a blackhole route is invoked. So return dst->dev->mtu
as the default mtu instead.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

C assignment can handle struct in6_addr copying.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The support for NLM_F_* flags at IPv6 routing requests.

Warn if NLM_F_CREATE flag is not defined for RTM_NEWROUTE request,
creating new table. Later NLM_F_CREATE may be required for
new route creation.

Patch created against linux-3.2-rc1
Signed-off-by: NMatti Vaittinen <Mazziesaccount@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

in func icmp6_dst_alloc,dst_metric_set call ipv6_cow_metrics to set metric.
ipv6_cow_metrics may will call rt6_bind_peer to set rt6_info->rt6i_peer.
So,we should move ipv6_addr_copy before dst_metric_set to make sure rt6_bind_peer success.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

return value of dst_alloc must be checked before use
Signed-off-by: NMadalin Bucur <madalin.bucur@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current IPv6 implementation uses inetpeer to store metrics for
routes. The problem of inetpeer is that it doesn't take subnet
prefix length in to consideration. If two routes have the same
address but different prefix length, they share same inetpeer.
So changing metrics of one route also affects the other. The
fix is to allocate separate metrics storage for each route.
Signed-off-by: NZheng Yan <zheng.z.yan@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Gergely Kalman reported crashes in check_peer_redir().

It appears commit f39925db (ipv4: Cache learned redirect
information in inetpeer.) added a race, leading to possible NULL ptr
dereference.

Since we can now change dst neighbour, we should make sure a reader can
safely use a neighbour.

Add RCU protection to dst neighbour, and make sure check_peer_redir()
can be called safely by different cpus in parallel.

As neighbours are already freed after one RCU grace period, this patch
should not add typical RCU penalty (cache cold effects)

Many thanks to Gergely for providing a pretty report pointing to the
bug.
Reported-by: NGergely Kalman <synapse@hippy.csoma.elte.hu>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We currently cow metrics a bit too soon in IPv6 case : All routes are
tied to a single inetpeer entry.

Change ip6_rt_copy() to get destination address as second argument, so
that we fill rt6i_dst before the dst_copy_metrics() call.

icmp6_dst_alloc() must set rt6i_dst before calling dst_metric_set(), or
else the cow is done while rt6i_dst is still NULL.

If orig route points to readonly metrics, we can share the pointer
instead of performing the memory allocation and copy.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the future dst entries will be neigh-less.  In that environment we
need to have an easy transition point for current users of
dst->neighbour outside of the packet output fast path.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dst_{get,set}_neighbour()
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It just makes it harder to see 1) what the code is doing
and 2) grep for all users of dst{->,.}neighbour
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPV6, unlike IPV4, doesn't have a routing cache.

Routing table entries, as well as clones made in response
to route lookup requests, all live in the same table.  And
all of these things are together collected in the destination
cache table for ipv6.

This means that routing table entries count against the garbage
collection limits, even though such entries cannot ever be reclaimed
and are added explicitly by the administrator (rather than being
created in response to lookups).

Therefore it makes no sense to count ipv6 routing table entries
against the GC limits.

Add a DST_NOCOUNT destination cache entry flag, and skip the counting
if it is set.  Use this flag bit in ipv6 when adding routing table
entries.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This blows away any flags already set in the entry.
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 c3968a85
('ipv6: RTA_PREFSRC support for ipv6 route source address selection')
added support for ipv6 prefsrc as an alternative to ipv6 addrlabels,
but it did not work because the prefsrc entry was not copied.

Cc: Daniel Walter <sahne@0x90.at>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
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>

The changes introduced with git-commit a02e4b7d ("ipv6: Demark default
hoplimit as zero.") missed to remove the hoplimit initialization. As a
result, ipv6_get_mtu interprets the return value of dst_metric_raw
(-1) as 255 and answers ping6 with this hoplimit.  This patche removes
the line such that ping6 is answered with the hoplimit value
configured via sysctl.
Signed-off-by: NThomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

[ipv6] Add support for RTA_PREFSRC

This patch allows a user to select the preferred source address
for a specific IPv6-Route. It can be set via a netlink message
setting RTA_PREFSRC to a valid IPv6 address which must be
up on the device the route will be bound to.
Signed-off-by: NDaniel Walter <dwalter@barracuda.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This avoids explicit cast to avoid 'discards qualifiers'
compiler warning in a netfilter patch that i've been working on.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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