linux-toradex.git/net/ipv4, branch v2.6.30.2

Revert "ipv4: arp announce, arp_proxy and windows ip conflict verification"

2009-07-20T03:38:54+00:00

commit f8a68e752bc4e39644843403168137663c984524 upstream.

This reverts commit 73ce7b01b4496a5fbf9caf63033c874be692333f.

After discovering that we don't listen to gratuitious arps in 2.6.30
I tracked the failure down to this commit.

The patch makes absolutely no sense.  RFC2131 RFC3927 and RFC5227.
are all in agreement that an arp request with sip == 0 should be used
for the probe (to prevent learning) and an arp request with sip == tip
should be used for the gratitous announcement that people can learn
from.

It appears the author of the broken patch got those two cases confused
and modified the code to drop all gratuitous arp traffic.  Ouch!

Signed-off-by: Eric W. Biederman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4 routing: Ensure that route cache entries are usable and reclaimable with caching is off

2009-07-02T23:49:41+00:00

[ Upstream commit b6280b47a7a42970d098a3059f4ebe7e55e90d8d ]

When route caching is disabled (rt_caching returns false), We still use route
cache entries that are created and passed into rt_intern_hash once.  These
routes need to be made usable for the one call path that holds a reference to
them, and they need to be reclaimed when they're finished with their use.  To be
made usable, they need to be associated with a neighbor table entry (which they
currently are not), otherwise iproute_finish2 just discards the packet, since we
don't know which L2 peer to send the packet to.  To do this binding, we need to
follow the path a bit higher up in rt_intern_hash, which calls
arp_bind_neighbour, but not assign the route entry to the hash table.
Currently, if caching is off, we simply assign the route to the rp pointer and
are reutrn success.  This patch associates us with a neighbor entry first.

Secondly, we need to make sure that any single use routes like this are known to
the garbage collector when caching is off.  If caching is off, and we try to
hash in a route, it will leak when its refcount reaches zero.  To avoid this,
this patch calls rt_free on the route cache entry passed into rt_intern_hash.
This places us on the gc list for the route cache garbage collector, so that
when its refcount reaches zero, it will be reclaimed (Thanks to Alexey for this
suggestion).

I've tested this on a local system here, and with these patches in place, I'm
able to maintain routed connectivity to remote systems, even if I set
/proc/sys/net/ipv4/rt_cache_rebuild_count to -1, which forces rt_caching to
return false.

Signed-off-by: Neil Horman 
Reported-by: Jarek Poplawski 
Reported-by: Maxime Bizon 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv4: fix NULL pointer + success return in route lookup path

2009-07-02T23:49:40+00:00

[ Upstream commit 73e42897e8e5619eacb787d2ce69be12f47cfc21 ]

Don't drop route if we're not caching

	I recently got a report of an oops on a route lookup.  Maxime was
testing what would happen if route caching was turned off (doing so by setting
making rt_caching always return 0), and found that it triggered an oops.  I
looked at it and found that the problem stemmed from the fact that the route
lookup routines were returning success from their lookup paths (which is good),
but never set the **rp pointer to anything (which is bad).  This happens because
in rt_intern_hash, if rt_caching returns false, we call rt_drop and return 0.
This almost emulates slient success.  What we should be doing is assigning *rp =
rt and _not_ dropping the route.  This way, during slow path lookups, when we
create a new route cache entry, we don't immediately discard it, rather we just
don't add it into the cache hash table, but we let this one lookup use it for
the purpose of this route request.  Maxime has tested and reports it prevents
the oops.  There is still a subsequent routing issue that I'm looking into
further, but I'm confident that, even if its related to this same path, this
patch makes sense to take.

Signed-off-by: Neil Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: tcp_vegas ssthresh bugfix

2009-05-26T05:44:59+00:00

This patch fixes ssthresh accounting issues in tcp_vegas when cwnd decreases

Signed-off-by: Doug Leith 
Signed-off-by: David S. Miller

ipv4: Fix oops with FIB_TRIE

2009-05-21T22:20:59+00:00

It seems we can fix this by disabling preemption while we re-balance the 
trie. This is with the CONFIG_CLASSIC_RCU. It's been stress-tested at high 
loads continuesly taking a full BGP table up/down via iproute -batch.

Note. fib_trie is not updated for CONFIG_PREEMPT_RCU

Reported-by: Andrei Popa
Signed-off-by: Robert Olsson 
Signed-off-by: David S. Miller

net: fix rtable leak in net/ipv4/route.c

2009-05-21T00:18:02+00:00

Alexander V. Lukyanov found a regression in 2.6.29 and made a complete
analysis found in http://bugzilla.kernel.org/show_bug.cgi?id=13339
Quoted here because its a perfect one :

begin_of_quotation
 2.6.29 patch has introduced flexible route cache rebuilding. Unfortunately the
 patch has at least one critical flaw, and another problem.

 rt_intern_hash calculates rthi pointer, which is later used for new entry
 insertion. The same loop calculates cand pointer which is used to clean the
 list. If the pointers are the same, rtable leak occurs, as first the cand is
 removed then the new entry is appended to it.

 This leak leads to unregister_netdevice problem (usage count > 0).

 Another problem of the patch is that it tries to insert the entries in certain
 order, to facilitate counting of entries distinct by all but QoS parameters.
 Unfortunately, referencing an existing rtable entry moves it to list beginning,
 to speed up further lookups, so the carefully built order is destroyed.

 For the first problem the simplest patch it to set rthi=0 when rthi==cand, but
 it will also destroy the ordering.
end_of_quotation

Problematic commit is 1080d709fb9d8cd4392f93476ee46a9d6ea05a5b
(net: implement emergency route cache rebulds when gc_elasticity is exceeded)

Trying to keep dst_entries ordered is too complex and breaks the fact that
order should depend on the frequency of use for garbage collection.

A possible fix is to make rt_intern_hash() simpler, and only makes
rt_check_expire() a litle bit smarter, being able to cope with an arbitrary
entries order. The added loop is running on cache hot data, while cpu
is prefetching next object, so should be unnoticied.

Reported-and-analyzed-by: Alexander V. Lukyanov 
Signed-off-by: Eric Dumazet 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

net: fix length computation in rt_check_expire()

2009-05-21T00:18:01+00:00

rt_check_expire() computes average and standard deviation of chain lengths,
but not correclty reset length to 0 at beginning of each chain.
This probably gives overflows for sum2 (and sum) on loaded machines instead
of meaningful results.

Signed-off-by: Eric Dumazet 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

ipv4: make default for INET_LRO consistent with help text

2009-05-19T04:48:38+00:00

Commit e81963b1 ("ipv4: Make INET_LRO a bool instead of tristate.")
changed this config from tristate to bool.  Add default so that it is
consistent with the help text.

Signed-off-by: Frans Pop 
Signed-off-by: David S. Miller

tcp: fix MSG_PEEK race check

2009-05-18T22:05:40+00:00

Commit 518a09ef11 (tcp: Fix recvmsg MSG_PEEK influence of
blocking behavior) lets the loop run longer than the race check
did previously expect, so we need to be more careful with this
check and consider the work we have been doing.

I tried my best to deal with urg hole madness too which happens
here:
	if (!sock_flag(sk, SOCK_URGINLINE)) {
		++*seq;
		...
by using additional offset by one but I certainly have very
little interest in testing that part.

Signed-off-by: Ilpo Järvinen 
Tested-by: Frans Pop 
Tested-by: Ian Zimmermann 
Signed-off-by: David S. Miller

ipconfig: handle case of delayed DHCP server

2009-05-18T03:39:33+00:00

If a DHCP server is delayed, it's possible for the client to receive the 
DHCPOFFER after it has already sent out a new DHCPDISCOVER message from 
a second interface.  The client then sends out a DHCPREQUEST from the 
second interface, but the server doesn't recognize the device and 
rejects the request.

This patch simply tracks the current device being configured and throws 
away the OFFER if it is not intended for the current device.  A more 
sophisticated approach would be to put the OFFER information into the 
struct ic_device rather than storing it globally.

Signed-off-by: Chris Friesen 
Signed-off-by: David S. Miller