Adding by commit 51ebd318 which adds the support of ECMP for IPv6.
Spotted-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Each nexthop is added like a single route in the routing table. All routes
that have the same metric/weight and destination but not the same gateway
are considering as ECMP routes. They are linked together, through a list called
rt6i_siblings.

ECMP routes can be added in one shot, with RTA_MULTIPATH attribute or one after
the other (in both case, the flag NLM_F_EXCL should not be set).

The patch is based on a previous work from
Luc Saillard <luc.saillard@6wind.com>.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

as we hold dst_entry before we call __ip6_del_rt,
so we should alse call dst_release not only return
-ENOENT when the rt6_info is ip6_null_entry.

and we already hold the dst entry, so I think it's
safe to call dst_release out of the write-read lock.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If dst cache dst_a copies from dst_b, and dst_b copies from dst_c, check
if dst_a is expired or not, we should not end with dst_a->dst.from, dst_b,
we should check dst_c.

CC: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 dst should take care of rt_genid too. When a xfrm policy is inserted or
deleted, all dst should be invalidated.
To force the validation, dst entries should be created with ->obsolete set to
DST_OBSOLETE_FORCE_CHK. This was already the case for all functions calling
ip6_dst_alloc(), except for ip6_rt_copy().

As a consequence, we can remove the specific code in inet6_connection_sock.
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

geting route info does not write rt->rt6i_table, so replace
write lock with read lock
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We kmemdup() templates, so they can be const.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After this commit:
	commit 97cac082
	Author: David S. Miller <davem@davemloft.net>
	Date:   Mon Jul 2 22:43:47 2012 -0700

	    ipv6: Store route neighbour in rt6_info struct.

we no longer use RCU to protect route neighbour.

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

It is a frequent mistake to confuse the netlink port identifier with a
process identifier.  Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's the same problem that previous fix about blackhole and prohibit routes.

When adding a throw route, it was handled like a classic route.
Moreover, it was only possible to add this kind of routes by specifying
an interface.

Before the patch:
  $ ip route add throw 2001::2/128
  RTNETLINK answers: No such device
  $ ip route add throw 2001::2/128 dev eth0
  $ ip -6 route | grep 2001::2
  2001::2 dev eth0  metric 1024

After:
  $ ip route add throw 2001::2/128
  $ ip -6 route | grep 2001::2
  throw 2001::2 dev lo  metric 1024  error -11
Reported-by: NMarkus Stenberg <markus.stenberg@iki.fi>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When adding a blackhole or a prohibit route, they were handling like classic
routes. Moreover, it was only possible to add this kind of routes by specifying
an interface.

Bug already reported here:
  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=498498

Before the patch:
  $ ip route add blackhole 2001::1/128
  RTNETLINK answers: No such device
  $ ip route add blackhole 2001::1/128 dev eth0
  $ ip -6 route | grep 2001
  2001::1 dev eth0  metric 1024

After:
  $ ip route add blackhole 2001::1/128
  $ ip -6 route | grep 2001
  blackhole 2001::1 dev lo  metric 1024  error -22

v2: wrong patch
v3: add a field fc_type in struct fib6_config to store RTN_* type
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As pointed out, there are places, that access net->loopback_dev->ifindex
and after ifindex generation is made per-net this value becomes constant
equals 1. So go ahead and introduce the LOOPBACK_IFINDEX constant and use
it where appropriate.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When userspace use RTM_GETROUTE to dump route table, with an already
expired route entry, we always got an 'expires' value(2147157)
calculated base on INT_MAX.

The reason of this problem is in the following satement:
	rt->dst.expires - jiffies < INT_MAX
gcc promoted the type of both sides of '<' to unsigned long, thus
a small negative value would be considered greater than INT_MAX.

With the help of Eric Dumazet, do the out of bound checks in
rtnl_put_cacheinfo(), _after_ conversion to clock_t.
Signed-off-by: NLi Wei <lw@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a big comment explaining how the field works, and use defines
instead of magic constants for the values assigned to it.

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

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>

Userspace implementations of network routing protocols sometimes need to
tell RA-originated IPv6 routes from other kernel routes to make proper
routing decisions. This makes most sense for RA routes with nexthops,
namely, default routes and Route Information routes.

The intended mean of preserving RA route origin in a netlink message is
through indicating RTPROT_RA as protocol code. Function rt6_fill_node()
tried to do that for default routes, but its test condition was taken
wrong. This change is modeled after the original mailing list posting
by Jeff Haran. It fixes the test condition for default route case and
sets the same behaviour for Route Information case (both types use
nexthops). Handling of the 3rd RA route type, Prefix Information, is
left unchanged, as it stands for interface connected routes (without
nexthops).
Signed-off-by: NDenis Ovsienko <infrastation@yandex.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We start initializing the struct rt6_info at the first field
behind the struct dst_enty. This is error prone because it
might leave a new field uninitialized. So start initializing
the struct rt6_info right behind the dst_entry.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

And delete rt6_redirect(), since it is no longer used.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Hook it into dst_ops->redirect as well.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This sets things up so that we can have the protocol error handlers
call down into the ipv6 route code for redirects just as ipv4 already
does.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Nobody provides non-zero values any longer.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No longer needed.  TCP writes metrics, but now in it's own special
cache that does not dirty the route metrics.  Therefore there is no
longer any reason to pre-cow metrics in this way.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With help from Lin Ming.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

git commit 97cac082 (ipv6: Store route neighbour in rt6_info struct)
added a neighbour pointer to rt6_info. Currently we don't initialize
this pointer at allocation time. We assume this pointer to be valid
if it is not a null pointer, so initialize it on allocation.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This makes for a simplified conversion away from dst_get_neighbour*().

All code outside of ipv6 will use neigh lookups via dst_neigh_lookup*().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Causes the handler to use the daddr in the ipv4/ipv6 header when
the route gateway is unspecified (local subnet).
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to allow IPv6 packets originating locally to match rules with the "iff"
set to "lo".  This allows IPv6 rule matching work the same as it does for
IPv4.  From the iproute2 man page:

   iif NAME
		  select  the incoming device to match.  If the interface is loop‐
		  back, the rule only matches packets originating from this  host.
		  This  means that you may create separate routing tables for for‐
		  warded and local packets and, hence, completely segregate them.
Signed-off-by: NDavid McCullough <david_mccullough@mcafee.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.

This opens up a short time frame to access fib_table_hash with its pants
down.

Move the registration of the proc files to a later point in the init
order to avoid the race.

Tested :-)
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 2a0c451a.

It causes crashes, because now ip6_null_entry is used before
it is initialized.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mtu should be a __be32, not the mark.
Reported-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.

This opens up a short time frame to access fib_table_hash with its pants
down.

fib6_init() as a whole can't be moved to an earlier position as it also
registers the rtnetlink message handlers which should be registered at
the end. Therefore split it into fib6_init() which is run early and
fib6_init_late() to register the rtnetlink message handlers.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Reviewed-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

One tricky issue on the ipv6 side vs. ipv4 is that the ICMP callouts
to handle the error pass the 32-bit info cookie in network byte order
whereas ipv4 passes it around in host byte order.

Like the ipv4 side, we have two helper functions.  One for when we
have a socket context and one for when we do not.

ip6ip6 tunnels are not handled here, because they handle PMTU events
by essentially relaying another ICMP packet-too-big message back to
the original sender.

This patch allows us to get rid of rt6_do_pmtu_disc().  It handles all
kinds of situations that simply cannot happen when we do the PMTU
update directly using a fully resolved route.

In fact, the "plen == 128" check in ip6_rt_update_pmtu() can very
likely be removed or changed into a BUG_ON() check.  We should never
have a prefixed ipv6 route when we get there.

Another piece of strange history here is that TCP and DCCP, unlike in
ipv4, never invoke the update_pmtu() method from their ICMP error
handlers.  This is incredibly astonishing since this is the context
where we have the most accurate context in which to make a PMTU
update, namely we have a fully connected socket and associated cached
socket route.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We handle NULL in rt{,6}_set_peer but then our caller will try to pass
that NULL pointer into inet_putpeer() which isn't ready for it.

Fix this by moving the NULL check one level up, and then remove the
now unnecessary NULL check from inetpeer_ptr_set_peer().
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

We encode the pointer(s) into an unsigned long with one state bit.

The state bit is used so we can store the inetpeer tree root to use
when resolving the peer later.

Later the peer roots will be per-FIB table, and this change works to
facilitate that.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise we reference potentially non-existing members when
ipv6 is disabled.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>