linux-stable.git/net/ipv4/ip_gre.c, branch linux-3.3.y

gre: fix spelling in comments

2012-02-24T22:41:11+00:00

The original spelling and bad word choice makes these comments hard to read.

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

ipv6: Fix ip_gre lockless xmits.

2012-01-26T21:34:08+00:00

Tunnel devices set NETIF_F_LLTX to bypass HARD_TX_LOCK.  Sit and
ipip set this unconditionally in ops->setup, but gre enables it
conditionally after parameter passing in ops->newlink. This is
not called during tunnel setup as below, however, so GRE tunnels are
still taking the lock.

modprobe ip_gre
ip tunnel add test0 mode gre remote 10.5.1.1 dev lo
ip link set test0 up
ip addr add 10.6.0.1 dev test0
 # cat /sys/class/net/test0/features
 # $DIR/test_tunnel_xmit 10 10.5.2.1
ip route add 10.5.2.0/24 dev test0
ip tunnel del test0

The newlink callback is only called in rtnl_netlink, and only if
the device is new, as it calls register_netdevice internally. Gre
tunnels are created at 'ip tunnel add' with ioctl SIOCADDTUNNEL,
which calls ipgre_tunnel_locate, which calls register_netdev.
rtnl_newlink is called at 'ip link set', but skips ops->newlink
and the device is up with locking still enabled. The equivalent
ipip tunnel works fine, btw (just substitute 'method gre' for
'method ipip').

On kernels before /sys/class/net/*/features was removed [1],
the first commented out line returns 0x6000 with method gre,
which indicates that NETIF_F_LLTX (0x1000) is not set. With ipip,
it reports 0x7000. This test cannot be used on recent kernels where
the sysfs file is removed (and ETHTOOL_GFEATURES does not currently
work for tunnel devices, because they lack dev->ethtool_ops).

The second commented out line calls a simple transmission test [2]
that sends on 24 cores at maximum rate. Results of a single run:

ipip:			19,372,306
gre before patch:	 4,839,753
gre after patch:	19,133,873

This patch replicates the condition check in ipgre_newlink to
ipgre_tunnel_locate. It works for me, both with oseq on and off.
This is the first time I looked at rtnetlink and iproute2 code,
though, so someone more knowledgeable should probably check the
patch. Thanks.

The tail of both functions is now identical, by the way. To avoid
code duplication, I'll be happy to rework this and merge the two.

[1] http://patchwork.ozlabs.org/patch/104610/
[2] http://kernel.googlecode.com/files/xmit_udp_parallel.c

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

net: use IS_ENABLED(CONFIG_IPV6)

2011-12-11T23:25:16+00:00

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

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

net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}.

2011-12-05T20:20:19+00:00

To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.

Signed-off-by: David S. Miller 
Acked-by: Roland Dreier

ip_gre: Set needed_headroom dynamically again

2011-11-18T19:37:10+00:00

ip_gre: Set needed_headroom dynamically again

Now that all needed_headroom users have been fixed up so that
we can safely increase needed_headroom, this patch restore the
dynamic update of needed_headroom.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

net: better pcpu data alignment

2011-11-08T20:10:59+00:00

Tunnels can force an alignment of their percpu data to reduce number of
cache lines used in fast path, or read in .ndo_get_stats()

percpu_alloc() is a very fine grained allocator, so any small hole will
be used anyway.

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

ip_gre: dont increase dev->needed_headroom on a live device

2011-10-20T20:20:30+00:00

It seems ip_gre is able to change dev->needed_headroom on the fly.

Its is not legal unfortunately and triggers a BUG in raw_sendmsg()

skb = sock_alloc_send_skb(sk, ... + LL_ALLOCATED_SPACE(rt->dst.dev)

< another cpu change dev->needed_headromm (making it bigger)

...
skb_reserve(skb, LL_RESERVED_SPACE(rt->dst.dev));

We end with LL_RESERVED_SPACE() being bigger than LL_ALLOCATED_SPACE()
-> we crash later because skb head is exhausted.

Bug introduced in commit 243aad83 in 2.6.34 (ip_gre: include route
header_len in max_headroom calculation)

Reported-by: Elmar Vonlanthen 
Signed-off-by: Eric Dumazet 
CC: Timo Teräs 
CC: Herbert Xu 
Signed-off-by: David S. Miller

net: Abstract dst->neighbour accesses behind helpers.

2011-07-18T06:11:35+00:00

dst_{get,set}_neighbour()

Signed-off-by: David S. Miller

net: call dev_alloc_name from register_netdevice

2011-05-05T17:57:45+00:00

Force dev_alloc_name() to be called from register_netdevice() by
dev_get_valid_name(). That allows to remove multiple explicit
dev_alloc_name() calls.

The possibility to call dev_alloc_name in advance remains.

This also fixes veth creation regresion caused by
84c49d8c3e4abefb0a41a77b25aa37ebe8d6b743

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

ipv4: Kill rt->rt_{src, dst} usage in IP GRE tunnels.

2011-05-04T19:55:07+00:00

First, make callers pass on-stack flowi4 to ip_route_output_gre()
so they can get at the fully resolved flow key.

Next, use that in ipgre_tunnel_xmit() to avoid the need to use
rt->rt_{dst,src}.

Signed-off-by: David S. Miller