linux.git/net/core, branch v3.13-rc2

gso: handle new frag_list of frags GRO packets

2013-11-21T19:11:50+00:00

Recently GRO started generating packets with frag_lists of frags.
This was not handled by GSO, thus leading to a crash.

Thankfully these packets are of a regular form and are easy to
handle.  This patch handles them in two ways.  For completely
non-linear frag_list entries, we simply continue to iterate over
the frag_list frags once we exhaust the normal frags.  For frag_list
entries with linear parts, we call pskb_trim on the first part
of the frag_list skb, and then process the rest of the frags in
the usual way.

This patch also kills a chunk of dead frag_list code that has
obviously never ever been run since it ends up generating a bogus
GSO-segmented packet with a frag_list entry.

Future work is planned to split super big packets into TSO
ones.

Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb")
Reported-by: Christoph Paasch 
Reported-by: Jerry Chu 
Reported-by: Sander Eikelenboom 
Signed-off-by: Herbert Xu 
Signed-off-by: Eric Dumazet 
Tested-by: Sander Eikelenboom 
Tested-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: rework recvmsg handler msg_name and msg_namelen logic

2013-11-21T02:52:30+00:00

This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller 
Suggested-by: Eric Dumazet 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

net: core: Always propagate flag changes to interfaces

2013-11-20T20:29:56+00:00

The following commit:
    b6c40d68ff6498b7f63ddf97cf0aa818d748dee7
    net: only invoke dev->change_rx_flags when device is UP

tried to fix a problem with VLAN devices and promiscuouse flag setting.
The issue was that VLAN device was setting a flag on an interface that
was down, thus resulting in bad promiscuity count.
This commit blocked flag propagation to any device that is currently
down.

A later commit:
    deede2fabe24e00bd7e246eb81cd5767dc6fcfc7
    vlan: Don't propagate flag changes on down interfaces

fixed VLAN code to only propagate flags when the VLAN interface is up,
thus fixing the same issue as above, only localized to VLAN.

The problem we have now is that if we have create a complex stack
involving multiple software devices like bridges, bonds, and vlans,
then it is possible that the flags would not propagate properly to
the physical devices.  A simple examle of the scenario is the
following:

  eth0----> bond0 ----> bridge0 ---> vlan50

If bond0 or eth0 happen to be down at the time bond0 is added to
the bridge, then eth0 will never have promisc mode set which is
currently required for operation as part of the bridge.  As a
result, packets with vlan50 will be dropped by the interface.

The only 2 devices that implement the special flag handling are
VLAN and DSA and they both have required code to prevent incorrect
flag propagation.  As a result we can remove the generic solution
introduced in b6c40d68ff6498b7f63ddf97cf0aa818d748dee7 and leave
it to the individual devices to decide whether they will block
flag propagation or not.

Reported-by: Stefan Priebe 
Suggested-by: Veaceslav Falico 
Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

genetlink: make multicast groups const, prevent abuse

2013-11-19T21:39:06+00:00

Register generic netlink multicast groups as an array with
the family and give them contiguous group IDs. Then instead
of passing the global group ID to the various functions that
send messages, pass the ID relative to the family - for most
families that's just 0 because the only have one group.

This avoids the list_head and ID in each group, adding a new
field for the mcast group ID offset to the family.

At the same time, this allows us to prevent abusing groups
again like the quota and dropmon code did, since we can now
check that a family only uses a group it owns.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

genetlink: pass family to functions using groups

2013-11-19T21:39:06+00:00

This doesn't really change anything, but prepares for the
next patch that will change the APIs to pass the group ID
within the family, rather than the global group ID.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

drop_monitor/genetlink: use proper genetlink multicast APIs

2013-11-19T21:39:05+00:00

The drop monitor code is abusing the genetlink API and is
statically using the generic netlink multicast group 1, even
if that group belongs to somebody else (which it invariably
will, since it's not reserved.)

Make the drop monitor code use the proper APIs to reserve a
group ID, but also reserve the group id 1 in generic netlink
code to preserve the userspace API. Since drop monitor can
be a module, don't clear the bit for it on unregistration.

Acked-by: Neil Horman 
Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

genetlink: only pass array to genl_register_family_with_ops()

2013-11-19T21:39:05+00:00

As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.

The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

macvlan: disable LRO on lower device instead of macvlan

2013-11-15T22:55:48+00:00

A macvlan device has always LRO disabled so that calling
dev_disable_lro() on it does nothing. If we need to disable LRO
e.g. because

  - the macvlan device is inserted into a bridge
  - IPv6 forwarding is enabled for it
  - it is in a different namespace than lowerdev and IPv4
    forwarding is enabled in it

we need to disable LRO on its underlying device instead (as we
do for 802.1q VLAN devices).

v2: use newly introduced netif_is_macvlan()

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller

genetlink: make all genl_ops users const

2013-11-14T22:10:41+00:00

Now that genl_ops are no longer modified in place when
registering, they can be made const. This patch was done
mostly with spatch:

@@
identifier ops;
@@
+const
 struct genl_ops ops[] = {
 ...
 };

(except the struct thing in net/openvswitch/datapath.c)

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

core/dev: do not ignore dmac in dev_forward_skb()

2013-11-14T07:39:53+00:00

commit 06a23fe31ca3
("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()")
and refactoring 64261f230a91
("dev: move skb_scrub_packet() after eth_type_trans()")

are forcing pkt_type to be PACKET_HOST when skb traverses veth.

which means that ip forwarding will kick in inside netns
even if skb->eth->h_dest != dev->dev_addr

Fix order of eth_type_trans() and skb_scrub_packet() in dev_forward_skb()
and in ip_tunnel_rcv()

Fixes: 06a23fe31ca3 ("core/dev: set pkt_type after eth_type_trans() in dev_forward_skb()")
CC: Isaku Yamahata 
CC: Maciej Zenczykowski 
CC: Nicolas Dichtel 
Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller