linux-stable.git/net/core/dev.c, branch v3.2.30

af_packet: don't emit packet on orig fanout group

2012-09-19T14:04:55+00:00

[ Upstream commit c0de08d04215031d68fa13af36f347a6cfa252ca ]

If a packet is emitted on one socket in one group of fanout sockets,
it is transmitted again. It is thus read again on one of the sockets
of the fanout group. This result in a loop for software which
generate packets when receiving one.
This retransmission is not the intended behavior: a fanout group
must behave like a single socket. The packet should not be
transmitted on a socket if it originates from a socket belonging
to the same fanout group.

This patch fixes the issue by changing the transmission check to
take fanout group info account.

Reported-by: Aleksandr Kotov 
Signed-off-by: Eric Leblond 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net/core: Fix potential memory leak in dev_set_alias()

2012-09-19T14:04:48+00:00

[ Upstream commit 7364e445f62825758fa61195d237a5b8ecdd06ec ]

Do not leak memory by updating pointer with potentially NULL realloc return value.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: Allow driver to limit number of GSO segments per skb

2012-09-19T14:04:46+00:00

[ Upstream commit 30b678d844af3305cda5953467005cebb5d7b687 ]

A peer (or local user) may cause TCP to use a nominal MSS of as little
as 88 (actual MSS of 76 with timestamps).  Given that we have a
sufficiently prodigious local sender and the peer ACKs quickly enough,
it is nevertheless possible to grow the window for such a connection
to the point that we will try to send just under 64K at once.  This
results in a single skb that expands to 861 segments.

In some drivers with TSO support, such an skb will require hundreds of
DMA descriptors; a substantial fraction of a TX ring or even more than
a full ring.  The TX queue selected for the skb may stall and trigger
the TX watchdog repeatedly (since the problem skb will be retried
after the TX reset).  This particularly affects sfc, for which the
issue is designated as CVE-2012-3412.

Therefore:
1. Add the field net_device::gso_max_segs holding the device-specific
   limit.
2. In netif_skb_features(), if the number of segments is too high then
   mask out GSO features to force fall back to software GSO.

Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: feed /dev/random with the MAC address when registering a device

2012-08-09T23:24:44+00:00

commit 7bf2357524408b97fec58344caf7397f8140c3fd upstream.

Cc: David Miller 
Cc: Linus Torvalds 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

net: remove skb_orphan_try()

2012-07-25T03:11:40+00:00

commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 upstream.

Orphaning skb in dev_hard_start_xmit() makes bonding behavior
unfriendly for applications sending big UDP bursts : Once packets
pass the bonding device and come to real device, they might hit a full
qdisc and be dropped. Without orphaning, the sender is automatically
throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming
sk_sndbuf is not too big)

We could try to defer the orphaning adding another test in
dev_hard_start_xmit(), but all this seems of little gain,
now that BQL tends to make packets more likely to be parked
in Qdisc queues instead of NIC TX ring, in cases where performance
matters.

Reverts commits :
fc6055a5ba31 net: Introduce skb_orphan_try()
87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try()
and removes SKBTX_DRV_NEEDS_SK_REF flag

Reported-and-bisected-by: Jean-Michel Hautbois 
Signed-off-by: Eric Dumazet 
Tested-by: Oliver Hartkopp 
Acked-by: Oliver Hartkopp 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Adjust context
 - SKBTX_WIFI_STATUS is not defined]
Signed-off-by: Ben Hutchings

Revert "net: maintain namespace isolation between vlan and real device"

2012-06-10T13:42:05+00:00

[ Upstream commit 59b9997baba5242997ddc7bd96b1391f5275a5a4 ]

This reverts commit 8a83a00b0735190384a348156837918271034144.

It causes regressions for S390 devices, because it does an
unconditional DST drop on SKBs for vlans and the QETH device
needs the neighbour entry hung off the DST for certain things
on transmit.

Arnd can't remember exactly why he even needed this change.

Conflicts:

	drivers/net/macvlan.c
	net/8021q/vlan_dev.c
	net/core/dev.c

Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: In unregister_netdevice_notifier unregister the netdevices.

2012-05-20T21:56:34+00:00

[ Upstream commit 7d3d43dab4e978d8d9ad1acf8af15c9b1c4b0f0f ]

We already synthesize events in register_netdevice_notifier and synthesizing
events in unregister_netdevice_notifier allows to us remove the need for
special case cleanup code.

This change should be safe as it adds no new cases for existing callers
of unregiser_netdevice_notifier to handle.

Signed-off-by: Eric W. Biederman 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: fix /proc/net/dev regression

2012-05-11T12:14:16+00:00

[ Upstream commit 2def16ae6b0c77571200f18ba4be049b03d75579 ]

Commit f04565ddf52 (dev: use name hash for dev_seq_ops) added a second
regression, as some devices are missing from /proc/net/dev if many
devices are defined.

When seq_file buffer is filled, the last ->next/show() method is
canceled (pos value is reverted to value prior ->next() call)

Problem is after above commit, we dont restart the lookup at right
position in ->start() method.

Fix this by removing the internal 'pos' pointer added in commit, since
we need to use the 'loff_t *pos' provided by seq_file layer.

This also reverts commit 5cac98dd0 (net: Fix corruption
in /proc/*/net/dev_mcast), since its not needed anymore.

Reported-by: Ben Greear 
Signed-off-by: Eric Dumazet 
Cc: Mihai Maruseac 
Tested-by:  Ben Greear 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: fix napi_reuse_skb() skb reserve

2012-04-02T16:53:08+00:00

[ Upstream commit 2a2a459eeeff48640dc557548ce576d666ab06ed ]

napi->skb is allocated in napi_get_frags() using
netdev_alloc_skb_ip_align(), with a reserve of NET_SKB_PAD +
NET_IP_ALIGN bytes.

However, when such skb is recycled in napi_reuse_skb(), it ends with a
reserve of NET_IP_ALIGN which is suboptimal.

Signed-off-by: Eric Dumazet 
Cc: Herbert Xu 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

gro: more generic L2 header check

2012-03-01T00:31:04+00:00

[ Upstream commit 5ca3b72c5da47d95b83857b768def6172fbc080a ]

Shlomo Pongratz reported GRO L2 header check was suited for Ethernet
only, and failed on IB/ipoib traffic.

He provided a patch faking a zeroed header to let GRO aggregates frames.

Roland Dreier, Herbert Xu, and others suggested we change GRO L2 header
check to be more generic, ie not assuming L2 header is 14 bytes, but
taking into account hard_header_len.

__napi_gro_receive() has special handling for the common case (Ethernet)
to avoid a memcmp() call and use an inline optimized function instead.

Signed-off-by: Eric Dumazet 
Reported-by: Shlomo Pongratz 
Cc: Roland Dreier 
Cc: Or Gerlitz 
Cc: Herbert Xu 
Tested-by: Sean Hefty 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman