Commit Graph

368 Commits

Author SHA1 Message Date
David S. Miller a6ff1a2f1e Merge branch 'nexthop_exceptions'
These patches implement the final mechanism necessary to really allow
us to go without the route cache in ipv4.

We need a place to have long-term storage of PMTU/redirect information
which is independent of the routes themselves, yet does not get us
back into a situation where we have to write to metrics or anything
like that.

For this we use an "next-hop exception" table in the FIB nexthops.

The one thing I desperately want to avoid is having to create clone
routes in the FIB trie for this purpose, because that is very
expensive.   However, I'm willing to entertain such an idea later
if this current scheme proves to have downsides that the FIB trie
variant would not have.

In order to accomodate this any such scheme, we need to be able to
produce a full flow key at PMTU/redirect time.  That required an
adjustment of the interface call-sites used to propagate these events.

For a PMTU/redirect with a fully specified socket, we pass that socket
and use it to produce the flow key.

Otherwise we use a passed in SKB to formulate the key.  There are two
cases that need to be distinguished, ICMP message processing (in which
case the IP header is at skb->data) and output packet processing
(mostly tunnels, and in all such cases the IP header is at ip_hdr(skb)).

We also have to make the code able to handle the case where the dst
itself passed into the dst_ops->{update_pmtu,redirect} method is
invalidated.  This matters for calls from sockets that have cached
that route.  We provide a inet{,6} helper function for this purpose,
and edit SCTP specially since it caches routes at the transport rather
than socket level.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 10:48:26 -07:00
David S. Miller 6700c2709c net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()
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: David S. Miller <davem@davemloft.net>
2012-07-17 03:29:28 -07:00
Denis Ovsienko f0396f60d7 ipv6: fix RTPROT_RA markup of RA routes w/nexthops
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: Denis Ovsienko <infrastation@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16 22:55:54 -07:00
Steffen Klassert 8104891b86 ipv6: Initialize the struct rt6_info behind the dst_enty field
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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-14 00:29:12 -07:00
David S. Miller b587ee3ba2 net: Add dummy dst_ops->redirect method where needed.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:39:24 -07:00
David S. Miller b94f1c0904 ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().
And delete rt6_redirect(), since it is no longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:33:37 -07:00
David S. Miller 3a5ad2ee5e ipv6: Add ip6_redirect() and ip6_sk_redirect() helper functions.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:08:07 -07:00
David S. Miller 6e157b6ac6 ipv6: Pull main logic of rt6_redirect() into rt6_do_redirect().
Hook it into dst_ops->redirect as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 00:05:02 -07:00
David S. Miller e8599ff4b1 ipv6: Move bulk of redirect handling into rt6_redirect().
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: David S. Miller <davem@davemloft.net>
2012-07-11 23:43:53 -07:00
David S. Miller 87a50699cb rtnetlink: Remove ts/tsage args to rtnl_put_cacheinfo().
Nobody provides non-zero values any longer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:13 -07:00
David S. Miller 3e12939a2a inet: Kill FLOWI_FLAG_PRECOW_METRICS.
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: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:12 -07:00
David S. Miller 81166dd6fa tcp: Move timestamps from inetpeer to metrics cache.
With help from Lin Ming.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:08 -07:00
Steffen Klassert a2de86f63c ipv6: Initialize the neighbour pointer of rt6_info on allocation
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: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 14:20:07 -07:00
David S. Miller 97cac0821a ipv6: Store route neighbour in rt6_info struct.
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: David S. Miller <davem@davemloft.net>
2012-07-05 02:41:58 -07:00
David S. Miller 1d248b1cf4 net: Pass neighbours and dest address into NETEVENT_REDIRECT events.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 02:21:55 -07:00
David S. Miller f894cbf847 net: Add optional SKB arg to dst_ops->neigh_lookup().
Causes the handler to use the daddr in the ipv4/ipv6 header when
the route gateway is unspecified (local subnet).

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 01:04:01 -07:00
David McCullough 4dc27d1cf3 net/ipv6/route.c: packets originating on device match lo
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: David McCullough <david_mccullough@mcafee.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 23:54:32 -07:00
David S. Miller e486463e82 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/qmi_wwan.c
	net/batman-adv/translation-table.c
	net/ipv6/route.c

qmi_wwan.c resolution provided by Bjørn Mork.

batman-adv conflict is dealing merely with the changes
of global function names to have a proper subsystem
prefix.

ipv6's route.c conflict is merely two side-by-side additions
of network namespace methods.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-25 15:50:32 -07:00
Thomas Graf d189634eca ipv6: Move ipv6 proc file registration to end of init order
/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: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-18 18:38:50 -07:00
David S. Miller aee289baaa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv6/route.c

Pull in 'net' again to get the revert of Thomas's change
which introduced regressions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-16 01:23:04 -07:00
David S. Miller e8803b6c38 Revert "ipv6: Prevent access to uninitialized fib_table_hash via /proc/net/ipv6_route"
This reverts commit 2a0c451ade.

It causes crashes, because now ip6_null_entry is used before
it is initialized.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-16 01:12:19 -07:00
David S. Miller 42ae66c80d ipv6: Fix types of ip6_update_pmtu().
The mtu should be a __be32, not the mark.

Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-15 20:01:57 -07:00
David S. Miller 7e52b33bd5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv6/route.c

This deals with a merge conflict between the net-next addition of the
inetpeer network namespace ops, and Thomas Graf's bug fix in
2a0c451ade which makes sure we don't
register /proc/net/ipv6_route before it is actually safe to do so.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-15 15:51:55 -07:00
Thomas Graf 2a0c451ade ipv6: Prevent access to uninitialized fib_table_hash via /proc/net/ipv6_route
/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: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-15 15:30:15 -07:00
David S. Miller 81aded2467 ipv6: Handle PMTU in ICMP error handlers.
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: David S. Miller <davem@davemloft.net>
2012-06-15 14:54:11 -07:00
David S. Miller 7b34ca2ac7 inet: Avoid potential NULL peer dereference.
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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-11 04:13:57 -07:00
David S. Miller 8b96d22d7a inet: Use FIB table peer roots in routes.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-11 02:10:54 -07:00
David S. Miller 97bab73f98 inet: Hide route peer accesses behind helpers.
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: David S. Miller <davem@davemloft.net>
2012-06-11 02:08:47 -07:00
David S. Miller c0efc887dc inet: Pass inetpeer root into inet_getpeer*() interfaces.
Otherwise we reference potentially non-existing members when
ipv6 is disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 19:12:36 -07:00
David S. Miller 2b823f7258 ipv6: Do not mark ipv6_inetpeer_ops as __net_initdata.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 19:00:16 -07:00
David S. Miller 56a6b248eb inet: Consolidate inetpeer_invalidate_tree() interfaces.
We only need one interface for this operation, since we always know
which inetpeer root we want to flush.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 16:32:41 -07:00
David S. Miller c3426b4719 inet: Initialize per-netns inetpeer roots in net/ipv{4,6}/route.c
Instead of net/ipv4/inetpeer.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09 16:27:05 -07:00
David S. Miller fbfe95a42e inet: Create and use rt{,6}_get_peer_create().
There's a lot of places that open-code rt{,6}_get_peer() only because
they want to set 'create' to one.  So add an rt{,6}_get_peer_create()
for their sake.

There were also a few spots open-coding plain rt{,6}_get_peer() and
those are transformed here as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-08 23:24:18 -07:00
Gao feng 54db0cc2ba inetpeer: add parameter net for inet_getpeer_v4,v6
add struct net as a parameter of inet_getpeer_v[4,6],
use net to replace &init_net.

and modify some places to provide net for inet_getpeer_v[4,6]

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-08 14:27:23 -07:00
Eric Dumazet a50feda546 ipv6: bool/const conversions phase2
Mostly bool conversions, some inline removals and const additions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-19 01:08:16 -04:00
Joe Perches f32138319c net: ipv6: Standardize prefixes for message logging
Add #define pr_fmt(fmt) as appropriate.

Add "IPv6: " to appropriate files.

Convert printk(KERN_<LEVEL> to pr_<level> (but not KERN_DEBUG).
Standardize on "%s: " not "%s(): " when emitting __func__.
Use "%s: ", __func__ instead of embedding function name.
Coalesce formats, align arguments.

ADDRCONF output is now prefixed with "IPv6: "

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-16 01:01:03 -04:00
Joe Perches e87cc4728f net: Convert net_ratelimit uses to net_<level>_ratelimited
Standardize the net core ratelimited logging functions.

Coalesce formats, align arguments.
Change a printk then vprintk sequence to use printf extension %pV.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-15 13:45:03 -04:00
David S. Miller 56845d78ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/atheros/atlx/atl1.c
	drivers/net/ethernet/atheros/atlx/atl1.h

Resolved a conflict between a DMA error bug fix and NAPI
support changes in the atl1 driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 13:19:04 -04:00
Eric Dumazet 95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
Gao feng 1716a96101 ipv6: fix problem with expired dst cache
If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet.
this dst cache will not check expire because it has no RTF_EXPIRES flag.
So this dst cache will always be used until the dst gc run.

Change the struct dst_entry,add a union contains new pointer from and expires.
When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use.
we can use this field to point to where the dst cache copy from.
The dst.from is only used in IPV6.

rt6_check_expired check if rt6_info.dst.from is expired.

ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.

ip6_dst_destroy release the ort.

Add some functions to operate the RTF_EXPIRES flag and expires(from) together.
and change the code to use these new adding functions.

Changes from v5:
modify ip6_route_add and ndisc_router_discovery to use new adding functions.

Only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 12:58:29 -04:00
Shmulik Ladkani 2173bff5dc ipv6: Fix 'inet6_rtm_getroute' to release 'rt->dst' in case of 'alloc_skb' failure
In 72331bc [ipv6: Fix RTM_GETROUTE's interpretation of RTA_IIF to be
consistent with ipv4] the code of 'inet6_rtm_getroute()' was re-ordered
such that the reference to 'rt->dst' is incremented prior skb
allocation.

Hence, if 'alloc_skb()' fails, must drop a reference from 'rt->dst'.
Add the missing 'dst_release()' call.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-04 05:25:51 -04:00
David S. Miller c78679e8f3 ipv6: Stop using NLA_PUT*().
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-02 04:33:43 -04:00
Shmulik Ladkani 72331bc0cd ipv6: Fix RTM_GETROUTE's interpretation of RTA_IIF to be consistent with ipv4
In IPv4, if an RTA_IIF attribute is specified within an RTM_GETROUTE
message, then a route is searched as if a packet was received on the
specified 'iif' interface.

However in IPv6, RTA_IIF is not interpreted in the same way:
'inet6_rtm_getroute()' always calls 'ip6_route_output()', regardless the
RTA_IIF attribute.

As a result, in IPv6 there's no way to use RTM_GETROUTE in order to look
for a route as if a packet was received on a specific interface.

Fix 'inet6_rtm_getroute()' so that RTA_IIF is interpreted as "lookup a
route as if a packet was received on the specified interface", similar
to IPv4's 'inet_rtm_getroute()' interpretation.

Reported-by: Ami Koren <amikoren@yahoo.com>
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-01 17:29:40 -04:00
Eric Dumazet 94f826b807 net: fix a potential rcu_read_lock() imbalance in rt6_fill_node()
Commit f2c31e32b3 (net: fix NULL dereferences in check_peer_redir() )
added a regression in rt6_fill_node(), leading to rcu_read_lock()
imbalance.

Thats because NLA_PUT() can make a jump to nla_put_failure label.

Fix this by using nla_put()

Many thanks to Ben Greear for his help

Reported-by: Ben Greear <greearb@candelatech.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-27 18:48:35 -04:00
David S. Miller 4da0bd7365 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-03-18 23:29:41 -04:00
Eric Dumazet 122bdf67f1 ipv6: fix icmp6_dst_alloc()
commit 87a115783 ( ipv6: Move xfrm_lookup() call down into
icmp6_dst_alloc().) forgot to convert one error path, leading
to crashes in mld_sendpack()

Many thanks to Dave Jones for providing a very complete bug report.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-16 01:53:42 -07:00
David S. Miller a7563f342d ipv6: Use ipv6_addr_any()
Suggested by YOSHIFUJI Hideaki.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-26 16:29:16 -05:00
David S. Miller 39232973b7 ipv4/ipv6: Prepare for new route gateway semantics.
In the future the ipv4/ipv6 route gateway will take on two types
of values:

1) INADDR_ANY/IN6ADDR_ANY, for local network routes, and in this case
   the neighbour must be obtained using the destination address in
   ipv4/ipv6 header as the lookup key.

2) Everything else, the actual nexthop route address.

So if the gateway is not inaddr-any we use it, otherwise we must use
the packet's destination address.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-26 15:22:32 -05:00
RongQing.Li 252c3d84ed ipv6: release idev when ip6_neigh_lookup failed in icmp6_dst_alloc
release idev when ip6_neigh_lookup failed in icmp6_dst_alloc

Signed-off-by: RongQing.Li <roy.qing.li@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-13 10:10:46 -08:00
Josh Hunt 32b293a53d IPv6: Avoid taking write lock for /proc/net/ipv6_route
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: Josh Hunt <joshhunt00@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30 17:07:33 -05:00