linux-toradex.git/net/packet, branch tegra

make PACKET_STATISTICS getsockopt report consistently between ring and non-ring

2011-10-03T18:18:26+00:00

This is a minor change.

Up until kernel 2.6.32, getsockopt(fd, SOL_PACKET, PACKET_STATISTICS,
...) would return total and dropped packets since its last invocation. The
introduction of socket queue overflow reporting [1] changed drop
rate calculation in the normal packet socket path, but not when using a
packet ring. As a result, the getsockopt now returns different statistics
depending on the reception method used. With a ring, it still returns the
count since the last call, as counts are incremented in tpacket_rcv and
reset in getsockopt. Without a ring, it returns 0 if no drops occurred
since the last getsockopt and the total drops over the lifespan of
the socket otherwise. The culprit is this line in packet_rcv, executed
on a drop:

drop_n_acct:
        po->stats.tp_drops = atomic_inc_return(&sk->sk_drops);

As it shows, the new drop number it taken from the socket drop counter,
which is not reset at getsockopt. I put together a small example
that demonstrates the issue [2]. It runs for 10 seconds and overflows
the queue/ring on every odd second. The reported drop rates are:
ring: 16, 0, 16, 0, 16, ...
non-ring: 0, 15, 0, 30, 0, 46, 0, 60, 0 , 74.

Note how the even ring counts monotonically increase. Because the
getsockopt adds tp_drops to tp_packets, total counts are similarly
reported cumulatively. Long story short, reinstating the original code, as
the below patch does, fixes the issue at the cost of additional per-packet
cycles. Another solution that does not introduce per-packet overhead
is be to keep the current data path, record the value of sk_drops at
getsockopt() at call N in a new field in struct packetsock and subtract
that when reporting at call N+1. I'll be happy to code that, instead,
it's just more messy.

[1] http://patchwork.ozlabs.org/patch/35665/
[2] http://kernel.googlecode.com/files/test-packetsock-getstatistics.c

Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

af-packet: fix - avoid reading stale data

2011-07-14T15:36:33+00:00

Currently we flush tp_status and then flush the remainder of the header+payload.
tp_status should be flushed in the end to avoid stale data being read by user-space.

Incorrectly re-ordered barriers in v1.

Signed-off-by: Chetan Loke 
Signed-off-by: David S. Miller

packet: Fix build with INET disabled.

2011-07-07T15:18:04+00:00

af_packet.c:(.text+0x3d130): undefined reference to `ip_defrag'
or
ERROR: "ip_defrag" [net/packet/af_packet.ko] undefined!

Reported-by: Randy Dunlap 
Signed-off-by: David S. Miller

af_packet: lock imbalance

2011-07-07T13:41:29+00:00

fanout_add() might return with fanout_mutex held.

Reduce indentation level while we are at it

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

packet: Fix leak in pre-defrag support.

2011-07-06T14:30:59+00:00

When we clone the SKB, we forget about the original
one.  Avoid this problem by using skb_share_check().

Reported-by: Penttilä Mika 
Signed-off-by: David S. Miller

packet: Add 'cpu' fanout policy.

2011-07-06T08:56:38+00:00

Unfortunately we have to use a real modulus here as
the multiply trick won't work as effectively with cpu
numbers as it does with rxhash values.

Signed-off-by: David S. Miller

packet: Add pre-defragmentation support for ipv4 fanouts.

2011-07-06T05:34:52+00:00

The skb->rxhash cannot be properly computed if the
packet is a fragment.  To alleviate this, allow the
AF_PACKET client to ask for defragmentation to be
done at demux time.

Signed-off-by: David S. Miller

packet: Add fanout support.

2011-07-06T05:34:52+00:00

Fanouts allow packet capturing to be demuxed to a set of AF_PACKET
sockets.  Two fanout policies are implemented:

1) Hashing based upon skb->rxhash

2) Pure round-robin

An AF_PACKET socket must be fully bound before it tries to add itself
to a fanout.  All AF_PACKET sockets trying to join the same fanout
must all have the same bind settings.

Fanouts are identified (within a network namespace) by a 16-bit ID.
The first socket to try to add itself to a fanout with a particular
ID, creates that fanout.  When the last socket leaves the fanout
(which happens only when the socket is closed), that fanout is
destroyed.

Signed-off-by: David S. Miller

packet: Add helpers to register/unregister ->prot_hook

2011-07-06T05:34:52+00:00

Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2011-06-21T05:29:08+00:00

Conflicts:
	drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
	drivers/net/wireless/rtlwifi/pci.c
	net/netfilter/ipvs/ip_vs_core.c