linux-stable.git/net/ipv4/route.c, branch linux-3.7.y

ipv4: Fix route refcount on pmtu discovery

2013-02-14T18:48:32+00:00

[ Upstream commit b44108dbdbaa07c609bb5755e8dd6c2035236251 ]

git commit 9cb3a50c (ipv4: Invalidate the socket cached route on
pmtu events if possible) introduced a refcount problem. We don't
get a refcount on the route if we get it from__sk_dst_get(), but
we need one if we want to reuse this route because __sk_dst_set()
releases the refcount of the old route. This patch adds proper
refcount handling for that case. We introduce a 'new' flag to
indicate that we are going to use a new route and we release the
old route only if we replace it by a new one.

Reported-by: Julian Anastasov 
Signed-off-by: Steffen Klassert 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: Invalidate the socket cached route on pmtu events if possible

2013-02-14T18:48:31+00:00

[ Upstream commit 9cb3a50c5f63ed745702972f66eaee8767659acd ]

The route lookup in ipv4_sk_update_pmtu() might return a route
different from the route we cached at the socket. This is because
standart routes are per cpu, so each cpu has it's own struct rtable.
This means that we do not invalidate the socket cached route if the
NET_RX_SOFTIRQ is not served by the same cpu that the sending socket
uses. As a result, the cached route reused until we disconnect.

With this patch we invalidate the socket cached route if possible.
If the socket is owened by the user, we can't update the cached
route directly. A followup patch will implement socket release
callback functions for datagram sockets to handle this case.

Reported-by: Yurij M. Plotnikov 
Signed-off-by: Steffen Klassert 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: Don't update the pmtu on mtu locked routes

2013-02-14T18:48:31+00:00

[ Upstream commit fa1e492aa3cbafba9f8fc6d05e5b08a3091daf4a ]

Routes with locked mtu should not use learned pmtu informations,
so do not update the pmtu on these routes.

Reported-by: Julian Anastasov 
Signed-off-by: Steffen Klassert 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: Remove output route check in ipv4_mtu

2013-02-14T18:48:30+00:00

[ Upstream commit 38d523e2948162776903349c89d65f7b9370dadb ]

The output route check was introduced with git commit 261663b0
(ipv4: Don't use the cached pmtu informations for input routes)
during times when we cached the pmtu informations on the
inetpeer. Now the pmtu informations are back in the routes,
so this check is obsolete. It also had some unwanted side effects,
as reported by Timo Teras and Lukas Tribus.

Signed-off-by: Steffen Klassert 
Acked-by: Timo Teräs 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: do not cache looped multicasts

2012-11-22T21:06:49+00:00

	Starting from 3.6 we cache output routes for
multicasts only when using route to 224/4. For local receivers
we can set RTCF_LOCAL flag depending on the membership but
in such case we use maddr and saddr which are not caching
keys as before. Additionally, we can not use same place to
cache routes that differ in RTCF_LOCAL flag value.

	Fix it by caching only RTCF_MULTICAST entries
without RTCF_LOCAL (send-only, no loopback). As a side effect,
we avoid unneeded lookup for fnhe when not caching because
multicasts are not redirected and they do not learn PMTU.

	Thanks to Maxime Bizon for showing the caching
problems in __mkroute_output for 3.6 kernels: different
RTCF_LOCAL flag in cache can lead to wrong ip_mc_output or
ip_output call and the visible problem is that traffic can
not reach local receivers via loopback.

Reported-by: Maxime Bizon 
Tested-by: Maxime Bizon 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller

xfrm: Fix the gc threshold value for ipv4

2012-11-13T08:15:07+00:00

The xfrm gc threshold value depends on ip_rt_max_size. This
value was set to INT_MAX with the routing cache removal patch,
so we start doing garbage collecting when we have INT_MAX/2
IPsec routes cached. Fix this by going back to the static
threshold of 1024 routes.

Signed-off-by: Steffen Klassert

ipv4: Fix flushing of cached routing informations

2012-10-18T19:34:30+00:00

Currently we can not flush cached pmtu/redirect informations via
the ipv4_sysctl_rtcache_flush sysctl. We need to check the rt_genid
of the old route and reset the nh exeption if the old route is
expired when we bind a new route to a nh exeption.

Signed-off-by: Steffen Klassert 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv4: fix route mark sparse warning

2012-10-11T02:54:59+00:00

Sparse complains about RTA_MARK which is should be host order according
to include file and usage in iproute.

net/ipv4/route.c:2223:46: warning: incorrect type in argument 3 (different base types)
net/ipv4/route.c:2223:46:    expected restricted __be32 [usertype] value
net/ipv4/route.c:2223:46:    got unsigned int [unsigned] [usertype] flowic_mark

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

ipv4: Add FLOWI_FLAG_KNOWN_NH

2012-10-08T21:42:36+00:00

Add flag to request that output route should be
returned with known rt_gateway, in case we want to use
it as nexthop for neighbour resolving.

	The returned route can be cached as follows:

- in NH exception: because the cached routes are not shared
	with other destinations
- in FIB NH: when using gateway because all destinations for
	NH share same gateway

	As last option, to return rt_gateway!=0 we have to
set DST_NOCACHE.

Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller

ipv4: introduce rt_uses_gateway

2012-10-08T21:42:36+00:00

Add new flag to remember when route is via gateway.
We will use it to allow rt_gateway to contain address of
directly connected host for the cases when DST_NOCACHE is
used or when the NH exception caches per-destination route
without DST_NOCACHE flag, i.e. when routes are not used for
other destinations. By this way we force the neighbour
resolving to work with the routed destination but we
can use different address in the packet, feature needed
for IPVS-DR where original packet for virtual IP is routed
via route to real IP.

Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller