Commit Graph

106 Commits

Author SHA1 Message Date
Xin Long deed49df73 route: check and remove route cache when we get route
Since the gc of ipv4 route was removed, the route cached would has
no chance to be removed, and even it has been timeout, it still could
be used, cause no code to check it's expires.

Fix this issue by checking  and removing route cache when we get route.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:31:36 -05:00
Lance Richardson 0797cbd8e2 ipv4: eliminate endianness warnings in ip_fib.h
fib_multipath_hash() computes a hash using __be32 values, force
cast these to u32 to pacify sparse.

Signed-off-by: Lance Richardson <lrichard@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-08 21:30:43 -05:00
David S. Miller 73186df8d7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor overlapping changes in net/ipv4/ipmr.c, in 'net' we were
fixing the "BH-ness" of the counter bumps whilst in 'net-next'
the functions were modified to take an explicit 'net' parameter.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-03 13:41:45 -05:00
Julian Anastasov 4f823defdd ipv4: fix to not remove local route on link down
When fib_netdev_event calls fib_disable_ip on NETDEV_DOWN event
we should not delete the local routes if the local address
is still present. The confusion comes from the fact that both
fib_netdev_event and fib_inetaddr_event use the NETDEV_DOWN
constant. Fix it by returning back the variable 'force'.

Steps to reproduce:
modprobe dummy
ifconfig dummy0 192.168.168.1 up
ifconfig dummy0 down
ip route list table local | grep dummy | grep host
local 192.168.168.1 dev dummy0  proto kernel  scope host  src 192.168.168.1

Fixes: 8a3d03166f ("net: track link-status of ipv4 nexthops")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-01 16:57:39 -05:00
David Ahern 3ce58d8435 net: Refactor path selection in __ip_route_output_key_hash
VRF device needs the same path selection following lookup to set source
address. Rather than duplicating code, move existing code into a
function that is exported to modules.

Code move only; no functional change.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:27:44 -07:00
Peter Nørlund 0e884c78ee ipv4: L3 hash-based multipath
Replaces the per-packet multipath with a hash-based multipath using
source and destination address.

Signed-off-by: Peter Nørlund <pch@ordbogen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 02:59:21 -07:00
Nikola Forró 0315e38270 net: Fix behaviour of unreachable, blackhole and prohibit routes
Man page of ip-route(8) says following about route types:

  unreachable - these destinations are unreachable.  Packets are dis‐
  carded and the ICMP message host unreachable is generated.  The local
  senders get an EHOSTUNREACH error.

  blackhole - these destinations are unreachable.  Packets are dis‐
  carded silently.  The local senders get an EINVAL error.

  prohibit - these destinations are unreachable.  Packets are discarded
  and the ICMP message communication administratively prohibited is
  generated.  The local senders get an EACCES error.

In the inet6 address family, this was correct, except the local senders
got ENETUNREACH error instead of EHOSTUNREACH in case of unreachable route.
In the inet address family, all three route types generated ICMP message
net unreachable, and the local senders got ENETUNREACH error.

In both address families all three route types now behave consistently
with documentation.

Signed-off-by: Nikola Forró <nforro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-20 21:45:08 -07:00
David S. Miller 5510b3c2a1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	arch/s390/net/bpf_jit_comp.c
	drivers/net/ethernet/ti/netcp_ethss.c
	net/bridge/br_multicast.c
	net/ipv4/ip_fragment.c

All four conflicts were cases of simple overlapping
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 23:52:20 -07:00
Julian Anastasov 2392debc2b ipv4: consider TOS in fib_select_default
fib_select_default considers alternative routes only when
res->fi is for the first alias in res->fa_head. In the
common case this can happen only when the initial lookup
matches the first alias with highest TOS value. This
prevents the alternative routes to require specific TOS.

This patch solves the problem as follows:

- routes that require specific TOS should be returned by
fib_select_default only when TOS matches, as already done
in fib_table_lookup. This rule implies that depending on the
TOS we can have many different lists of alternative gateways
and we have to keep the last used gateway (fa_default) in first
alias for the TOS instead of using single tb_default value.

- as the aliases are ordered by many keys (TOS desc,
fib_priority asc), we restrict the possible results to
routes with matching TOS and lowest metric (fib_priority)
and routes that match any TOS, again with lowest metric.

For example, packet with TOS 8 can not use gw3 (not lowest
metric), gw4 (different TOS) and gw6 (not lowest metric),
all other gateways can be used:

tos 8 via gw1 metric 2 <--- res->fa_head and res->fi
tos 8 via gw2 metric 2
tos 8 via gw3 metric 3
tos 4 via gw4
tos 0 via gw5
tos 0 via gw6 metric 1

Reported-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-24 22:46:11 -07:00
Roopa Prabhu 571e722676 ipv4: support for fib route lwtunnel encap attributes
This patch adds support in ipv4 fib functions to parse user
provided encap attributes and attach encap state data to fib_nh
and rtable.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21 10:39:03 -07:00
Andy Gospodarek 0eeb075fad net: ipv4 sysctl option to ignore routes when nexthop link is down
This feature is only enabled with the new per-interface or ipv4 global
sysctls called 'ignore_routes_with_linkdown'.

net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
...

When the above sysctls are set, will report to userspace that a route is
dead and will no longer resolve to this nexthop when performing a fib
lookup.  This will signal to userspace that the route will not be
selected.  The signalling of a RTNH_F_DEAD is only passed to userspace
if the sysctl is enabled and link is down.  This was done as without it
the netlink listeners would have no idea whether or not a nexthop would
be selected.   The kernel only sets RTNH_F_DEAD internally if the
interface has IFF_UP cleared.

With the new sysctl set, the following behavior can be observed
(interface p8p1 is link-down):

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 dead linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 dead linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
90.0.0.1 via 70.0.0.2 dev p7p1  src 70.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache <local>
80.0.0.2 via 10.0.5.2 dev p9p1  src 10.0.5.15
    cache

While the route does remain in the table (so it can be modified if
needed rather than being wiped away as it would be if IFF_UP was
cleared), the proper next-hop is chosen automatically when the link is
down.  Now interface p8p1 is linked-up:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
192.168.56.0/24 dev p2p1  proto kernel  scope link  src 192.168.56.2
90.0.0.1 via 80.0.0.2 dev p8p1  src 80.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache <local>
80.0.0.2 dev p8p1  src 80.0.0.1
    cache

and the output changes to what one would expect.

If the sysctl is not set, the following output would be expected when
p8p1 is down:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2

Since the dead flag does not appear, there should be no expectation that
the kernel would skip using this route due to link being down.

v2: Split kernel changes into 2 patches, this actually makes a
behavioral change if the sysctl is set.  Also took suggestion from Alex
to simplify code by only checking sysctl during fib lookup and
suggestion from Scott to add a per-interface sysctl.

v3: Code clean-ups to make it more readable and efficient as well as a
reverse path check fix.

v4: Drop binary sysctl

v5: Whitespace fixups from Dave

v6: Style changes from Dave and checkpatch suggestions

v7: One more checkpatch fixup

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:15:54 -07:00
Andy Gospodarek 8a3d03166f net: track link-status of ipv4 nexthops
Add a fib flag called RTNH_F_LINKDOWN to any ipv4 nexthops that are
reachable via an interface where carrier is off.  No action is taken,
but additional flags are passed to userspace to indicate carrier status.

This also includes a cleanup to fib_disable_ip to more clearly indicate
what event made the function call to replace the more cryptic force
option previously used.

v2: Split out kernel functionality into 2 patches, this patch simply
sets and clears new nexthop flag RTNH_F_LINKDOWN.

v3: Cleanups suggested by Alex as well as a bug noticed in
fib_sync_down_dev and fib_sync_up when multipath was not enabled.

v5: Whitespace and variable declaration fixups suggested by Dave.

v6: Style fixups noticed by Dave; ran checkpatch to be sure I got them
all.

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:15:54 -07:00
Alexander Duyck 0ddcf43d5d ipv4: FIB Local/MAIN table collapse
This patch is meant to collapse local and main into one by converting
tb_data from an array to a pointer.  Doing this allows us to point the
local table into the main while maintaining the same variables in the
table.

As such the tb_data was converted from an array to a pointer, and a new
array called data is added in order to still provide an object for tb_data
to point to.

In order to track the origin of the fib aliases a tb_id value was added in
a hole that existed on 64b systems.  Using this we can also reverse the
merge in the event that custom FIB rules are enabled.

With this patch I am seeing an improvement of 20ns to 30ns for routing
lookups as long as custom rules are not enabled, with custom rules enabled
we fall back to split tables and the original behavior.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 16:22:14 -04:00
Scott Feldman 104616e74e switchdev: don't support custom ip rules, for now
Keep switchdev FIB offload model simple for now and don't allow custom ip
rules.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:24:58 -05:00
Alexander Duyck a7e5353123 fib_trie: Make fib_table rcu safe
The fib_table was wrapped in several places with an
rcu_read_lock/rcu_read_unlock however after looking over the code I found
several spots where the tables were being accessed as just standard
pointers without any protections.  This change fixes that so that all of
the proper protections are in place when accessing the table to take RCU
replacement or removal of the table into account.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Alexander Duyck 56315f9e6e fib_trie: Convert fib_alias to hlist from list
There isn't any advantage to having it as a list and by making it an hlist
we make the fib_alias more compatible with the list_info in terms of the
type of list used.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:37:06 -05:00
Alexander Duyck 345e9b5426 fib_trie: Push rcu_read_lock/unlock to callers
This change is to start cleaning up some of the rcu_read_lock/unlock
handling.  I realized while reviewing the code there are several spots that
I don't believe are being handled correctly or are masking warnings by
locally calling rcu_read_lock/unlock instead of calling them at the correct
level.

A common example is a call to fib_get_table followed by fib_table_lookup.
The rcu_read_lock/unlock ought to wrap both but there are several spots where
they were not wrapped.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-31 18:25:54 -05:00
Alexander Duyck a5a519b271 fib_trie: Fix /proc/net/fib_trie when CONFIG_IP_MULTIPLE_TABLES is not defined
In recent testing I had disabled CONFIG_IP_MULTIPLE_TABLES and as a result
when I ran "cat /proc/net/fib_trie" the main trie was displayed multiple
times.  I found that the problem line of code was in the function
fib_trie_seq_next.  Specifically the line below caused the indexes to go in
the opposite direction of our traversal:

	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);

This issue was that the RT tables are defined such that RT_TABLE_LOCAL is ID
255, while it is located at TABLE_LOCAL_INDEX of 0, and RT_TABLE_MAIN is 254
with a TABLE_MAIN_INDEX of 1.  This means that the above line will return 1
for the local table and 0 for main.  The result is that fib_trie_seq_next
will return NULL at the end of the local table, fib_trie_seq_start will
return the start of the main table, and then fib_trie_seq_next will loop on
main forever as h will always return 0.

The fix for this is to reverse the ordering of the two tables.  It has the
advantage of making it so that the tables now print in the same order
regardless of if multiple tables are enabled or not.  In order to make the
definition consistent with the multiple tables case I simply masked the to
RT_TABLE_XXX values by (FIB_TABLE_HASHSZ - 1).  This way the two table
layouts should always stay consistent.

Fixes: 93456b6 ("[IPV4]: Unify access to the routing tables")
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-08 21:14:32 -05:00
Eric Dumazet d546c62154 ipv4: harden fnhe_hashfun()
Lets make this hash function a bit secure, as ICMP attacks are still
in the wild.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:40:33 -07:00
Eric Dumazet caa415270c ipv4: fix a race in update_or_create_fnhe()
nh_exceptions is effectively used under rcu, but lacks proper
barriers. Between kzalloc() and setting of nh->nh_exceptions(),
we need a proper memory barrier.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:15:50 -07:00
Joe Perches 5c3a0fd7d0 ip*.h: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-21 14:01:38 -04:00
Rami Rosen b48410b4dc ipv4: remove fib_update_nh_saddrs() declaration.
This patch removes the fib_update_nh_saddrs() declaration from
include/net/ip_fib.h, as the fib_update_nh_saddrs() method was removed in
coomit 436c3b6 ("ipv4: Invalidate nexthop cache nh_saddr more correctly").

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02 00:33:52 -07:00
Timo Teräs 2ffae99d1f ipv4: use next hop exceptions also for input routes
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: Timo Teräs <timo.teras@iki.fi>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28 21:27:47 -07:00
Timo Teräs 5aad1de5ea ipv4: use separate genid for next hop exceptions
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: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-03 00:07:43 -07:00
Denis V. Lunev 5b9e12dbf9 ipv4: fix definition of FIB_TABLE_HASHSZ
a long time ago by the commit

  commit 93456b6d77
  Author: Denis V. Lunev <den@openvz.org>
  Date:   Thu Jan 10 03:23:38 2008 -0800

    [IPV4]: Unify access to the routing tables.

the defenition of FIB_HASH_TABLE size has obtained wrong dependency:
it should depend upon CONFIG_IP_MULTIPLE_TABLES (as was in the original
code) but it was depended from CONFIG_IP_ROUTE_MULTIPATH

This patch returns the situation to the original state.

The problem was spotted by Tingwei Liu.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Tingwei Liu <tingw.liu@gmail.com>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-13 10:47:09 -04:00
Eric Dumazet f4ef85bbda ipv4: add a fib_type to fib_info
commit d2d68ba9fe (ipv4: Cache input routes in fib_info nexthops.)
introduced a regression for forwarding.

This was hard to reproduce but the symptom was that packets were
delivered to local host instead of being forwarded.

David suggested to add fib_type to fib_info so that we dont
inadvertently share same fib_info for different purposes.

With help from Julian Anastasov who provided very helpful
hints, reproduced here :

<quote>
        Can it be a problem related to fib_info reuse
from different routes. For example, when local IP address
is created for subnet we have:

broadcast 192.168.0.255 dev DEV  proto kernel  scope link  src
192.168.0.1
192.168.0.0/24 dev DEV  proto kernel  scope link  src 192.168.0.1
local 192.168.0.1 dev DEV  proto kernel  scope host  src 192.168.0.1

        The "dev DEV  proto kernel  scope link  src 192.168.0.1" is
a reused fib_info structure where we put cached routes.
The result can be same fib_info for 192.168.0.255 and
192.168.0.0/24. RTN_BROADCAST is cached only for input
routes. Incoming broadcast to 192.168.0.255 can be cached
and can cause problems for traffic forwarded to 192.168.0.0/24.
So, this patch should solve the problem because it
separates the broadcast from unicast traffic.

        And the ip_route_input_slow caching will work for
local and broadcast input routes (above routes 1 and 3) just
because they differ in scope and use different fib_info.

</quote>

Many thanks to Chris Clayton for his patience and help.

Reported-by: Chris Clayton <chris2553@googlemail.com>
Bisected-by: Chris Clayton <chris2553@googlemail.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-04 13:58:26 -04:00
David S. Miller c5038a8327 ipv4: Cache routes in nexthop exception entries.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31 15:02:02 -07:00
Eric Dumazet d26b3a7c4b ipv4: percpu nh_rth_output cache
Input path is mostly run under RCU and doesnt touch dst refcnt

But output path on forwarding or UDP workloads hits
badly dst refcount, and we have lot of false sharing, for example
in ipv4_mtu() when reading rt->rt_pmtu

Using a percpu cache for nh_rth_output gives a nice performance
increase at a small cost.

24 udpflood test on my 24 cpu machine (dummy0 output device)
(each process sends 1.000.000 udp frames, 24 processes are started)

before : 5.24 s
after : 2.06 s
For reference, time on linux-3.5 : 6.60 s

Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31 14:41:39 -07:00
Eric Dumazet 54764bb647 ipv4: Restore old dst_free() behavior.
commit 404e0a8b6a (net: ipv4: fix RCU races on dst refcounts) tried
to solve a race but added a problem at device/fib dismantle time :

We really want to call dst_free() as soon as possible, even if sockets
still have dst in their cache.
dst_release() calls in free_fib_info_rcu() are not welcomed.

Root of the problem was that now we also cache output routes (in
nh_rth_output), we must use call_rcu() instead of call_rcu_bh() in
rt_free(), because output route lookups are done in process context.

Based on feedback and initial patch from David Miller (adding another
call_rcu_bh() call in fib, but it appears it was not the right fix)

I left the inet_sk_rx_dst_set() helper and added __rcu attributes
to nh_rth_output and nh_rth_input to better document what is going on in
this code.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31 14:41:38 -07:00
David S. Miller d2d68ba9fe ipv4: Cache input routes in fib_info nexthops.
Caching input routes is slightly simpler than output routes, since we
don't need to be concerned with nexthop exceptions.  (locally
destined, and routed packets, never trigger PMTU events or redirects
that will be processed by us).

However, we have to elide caching for the DIRECTSRC and non-zero itag
cases.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:40 -07:00
David S. Miller f2bb4bedf3 ipv4: Cache output routes in fib_info nexthops.
If we have an output route that lacks nexthop exceptions, we can cache
it in the FIB info nexthop.

Such routes will have DST_HOST cleared because such routes refer to a
family of destinations, rather than just one.

The sequence of the handling of exceptions during route lookup is
adjusted to make the logic work properly.

Before we allocate the route, we lookup the exception.

Then we know if we will cache this route or not, and therefore whether
DST_HOST should be set on the allocated route.

Then we use DST_HOST to key off whether we should store the resulting
route, during rt_set_nexthop(), in the FIB nexthop cache.

With help from Eric Dumazet.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:16 -07:00
Julian Anastasov aee06da672 ipv4: use seqlock for nh_exceptions
Use global seqlock for the nh_exceptions. Call
fnhe_oldest with the right hash chain. Correct the diff
value for dst_set_expires.

v2: after suggestions from Eric Dumazet:
* get rid of spin lock fnhe_lock, rearrange update_or_create_fnhe
* continue daddr search in rt_bind_exception

v3:
* remove the daddr check before seqlock in rt_bind_exception
* restart lookup in rt_bind_exception on detected seqlock change,
as suggested by David Miller

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19 10:30:14 -07:00
David S. Miller 4895c771c7 ipv4: Add FIB nexthop exceptions.
In a regime where we have subnetted route entries, we need a way to
store persistent storage about destination specific learned values
such as redirects and PMTU values.

This is implemented here via nexthop exceptions.

The initial implementation is a 2048 entry hash table with relaiming
starting at chain length 5.  A more sophisticated scheme can be
devised if that proves necessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 08:48:50 -07:00
David S. Miller 85b91b0339 ipv4: Don't store a rule pointer in fib_result.
We only use it to fetch the rule's tclassid, so just store the
tclassid there instead.

This also decreases the size of fib_result by a full 8 bytes on
64-bit.  On 32-bits it's a wash.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13 08:21:29 -07:00
David S. Miller 391e5c22f5 ipv4: Remove tb_peers from fib_table.
No longer used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 09:39:28 -07:00
David S. Miller e044a651b9 ipv4: Fix crashes in fib_rules_tclass().
All paths assume, when CONFIG_IP_MULTIPLE_TABLES is enabled, that any
successful call to fib_lookup() will initialize the fib_result->r
value to something.

We violated that expectation in the new fib_lookup() fast path.

Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 18:05:28 -07:00
David S. Miller f4530fa574 ipv4: Avoid overhead when no custom FIB rules are installed.
If the user hasn't actually installed any custom rules, or fiddled
with the default ones, don't go through the whole FIB rules layer.

It's just pure overhead.

Instead do what we do with CONFIG_IP_MULTIPLE_TABLES disabled, check
the individual tables by hand, one by one.

Also, move fib_num_tclassid_users into the ipv4 network namespace.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05 22:13:13 -07:00
David S. Miller 7a9bc9b81a ipv4: Elide fib_validate_source() completely when possible.
If rpfilter is off (or the SKB has an IPSEC path) and there are not
tclassid users, we don't have to do anything at all when
fib_validate_source() is invoked besides setting the itag to zero.

We monitor tclassid uses with a counter (modified only under RTNL and
marked __read_mostly) and we protect the fib_validate_source() real
work with a test against this counter and whether rpfilter is to be
done.

Having a way to know whether we need no tclassid processing or not
also opens the door for future optimized rpfilter algorithms that do
not perform full FIB lookups.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 01:36:36 -07:00
David S. Miller 9e56e3800e ipv4: Adjust in_dev handling in fib_validate_source()
Checking for in_dev being NULL is pointless.

In fact, all of our callers have in_dev precomputed already,
so just pass it in and remove the NULL checking.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 18:54:02 -07:00
David S. Miller 41347dcdd8 ipv4: Kill rt->rt_spec_dst, no longer used.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 04:05:27 -07:00
David S. Miller 35ebf65e85 ipv4: Create and use fib_compute_spec_dst() helper.
The specific destination is the host we direct unicast replies to.
Usually this is the original packet source address, but if we are
responding to a multicast or broadcast packet we have to use something
different.

Specifically we must use the source address we would use if we were to
send a packet to the unicast source of the original packet.

The routing cache precomputes this value, but we want to remove that
precomputation because it creates a hard dependency on the expensive
rpfilter source address validation which we'd like to make cheaper.

There are only three places where this matters:

1) ICMP replies.

2) pktinfo CMSG

3) IP options

Now there will be no real users of rt->rt_spec_dst and we can simply
remove it altogether.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-28 03:59:11 -07:00
David S. Miller 8e77327783 inet: Add inetpeer tree roots to the FIB tables.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-11 02:09:16 -07:00
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
David S. Miller 21d8c49e01 ipv4: Call fib_select_default() only when actually necessary.
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: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
2011-04-14 15:05:22 -07:00
Michael Smith 5c04c819a2 fib_validate_source(): pass sk_buff instead of mark
This makes sk_buff available for other use in fib_validate_source().

Signed-off-by: Michael Smith <msmith@cbnco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-10 18:50:59 -07:00
David S. Miller 37e826c513 ipv4: Fix nexthop caching wrt. scoping.
Move the scope value out of the fib alias entries and into fib_info,
so that we always use the correct scope when recomputing the nexthop
cached source address.

Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-24 18:06:47 -07:00
David S. Miller 436c3b66ec ipv4: Invalidate nexthop cache nh_saddr more correctly.
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: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-24 17:42:21 -07:00
David S. Miller 22bd5b9b13 ipv4: Pass ipv4 flow objects into fib_lookup() paths.
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: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:47 -08:00
David S. Miller 1b7fe59322 ipv4: Kill flowi arg to fib_select_multipath()
Completely unused.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10 17:03:45 -08:00
David S. Miller a7ac8fc1d8 ipv4: Fix scope value used in route src-address caching.
We have to use cfg->fc_scope not the final nh_scope value.

Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-08 11:03:21 -08:00