linux-toradex.git/drivers/net/ppp, branch v3.2.68

fix misuses of f_count() in ppp and netlink

2014-12-14T16:23:47+00:00

commit 24dff96a37a2ca319e75a74d3929b2de22447ca6 upstream.

we used to check for "nobody else could start doing anything with
that opened file" by checking that refcount was 2 or less - one
for descriptor table and one we'd acquired in fget() on the way to
wherever we are.  That was race-prone (somebody else might have
had a reference to descriptor table and do fget() just as we'd
been checking) and it had become flat-out incorrect back when
we switched to fget_light() on those codepaths - unlike fget(),
it doesn't grab an extra reference unless the descriptor table
is shared.  The same change allowed a race-free check, though -
we are safe exactly when refcount is less than 2.

It was a long time ago; pre-2.6.12 for ioctl() (the codepath leading
to ppp one) and 2.6.17 for sendmsg() (netlink one).  OTOH,
netlink hadn't grown that check until 3.9 and ppp used to live
in drivers/net, not drivers/net/ppp until 3.1.  The bug existed
well before that, though, and the same fix used to apply in old
location of file.

Signed-off-by: Al Viro 
[bwh: Backported to 3.2: drop changes to netlink_mmap_sendmsg()]
Signed-off-by: Ben Hutchings

inetpeer: get rid of ip_id_count

2014-09-13T22:41:48+00:00

[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

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

net: rework recvmsg handler msg_name and msg_namelen logic

2014-01-03T04:33:33+00:00

[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ]

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 
Signed-off-by: Ben Hutchings

ip: generate unique IP identificator if local fragmentation is allowed

2013-10-26T20:06:08+00:00

[ Upstream commit 703133de331a7a7df47f31fb9de51dc6f68a9de8 ]

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

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

pppoe: drop PPPOX_ZOMBIEs in pppoe_release

2012-10-10T02:31:30+00:00

[ Upstream commit 2b018d57ff18e5405823e5cb59651a5b4d946d7b ]

When PPPOE is running over a virtual ethernet interface (e.g., a
bonding interface) and the user tries to delete the interface in case
the PPPOE state is ZOMBIE, the kernel will loop forever while
unregistering net_device for the reference count is not decreased to
zero which should have been done with dev_put().

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

pptp: lookup route with the proper net namespace

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

[ Upstream commit 08252b32311c3fa84219ad794d640af7399b5485 ]

pptp always use init_net as the net namespace to lookup
route, this will cause route lookup failed in container.

because we already set the correct net namespace to struct
sock in pptp_create,so fix this by using sock_net(sk) to
replace &init_net.

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

ppp: Don't stop and restart queue on every TX packet

2012-05-11T12:14:17+00:00

[ This combines upstream commit
  e675f0cc9a872fd152edc0c77acfed19bf28b81e and follow-on bug fix
  commit 9a5d2bd99e0dfe9a31b3c160073ac445ba3d773f ]

For every transmitted packet, ppp_start_xmit() will stop the netdev
queue and then, if appropriate, restart it. This causes the TX softirq
to run, entirely gratuitously.

This is "only" a waste of CPU time in the normal case, but it's actively
harmful when the PPP device is a TEQL slave — the wakeup will cause the
offending device to receive the next TX packet from the TEQL queue, when
it *should* have gone to the next slave in the list. We end up seeing
large bursts of packets on just *one* slave device, rather than using
the full available bandwidth over all slaves.

This patch fixes the problem by *not* unconditionally stopping the queue
in ppp_start_xmit(). It adds a return value from ppp_xmit_process()
which indicates whether the queue should be stopped or not.

It *doesn't* remove the call to netif_wake_queue() from
ppp_xmit_process(), because other code paths (especially from
ppp_output_wakeup()) need it there and it's messy to push it out to the
other callers to do it based on the return value. So we leave it in
place — it's a no-op in the case where the queue wasn't stopped, so it's
harmless in the TX path.

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

ppp: fix 'ppp_mp_reconstruct bad seq' errors

2012-03-19T16:02:21+00:00

[ Upstream commit 8a49ad6e89feb5015e77ce6efeb2678947117e20 ]

This patch fixes a (mostly cosmetic) bug introduced by the patch
'ppp: Use SKB queue abstraction interfaces in fragment processing'
found here: http://www.spinics.net/lists/netdev/msg153312.html

The above patch rewrote and moved the code responsible for cleaning
up discarded fragments but the new code does not catch every case
where this is necessary.  This results in some discarded fragments
remaining in the queue, and triggering a 'bad seq' error on the
subsequent call to ppp_mp_reconstruct.  Fragments are discarded
whenever other fragments of the same frame have been lost.
This can generate a lot of unwanted and misleading log messages.

This patch also adds additional detail to the debug logging to
make it clearer which fragments were lost and which other fragments
were discarded as a result of losses. (Run pppd with 'kdebug 1'
option to enable debug logging.)

Signed-off-by: Ben McKeegan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ppp: fix pptp double release_sock in pptp_bind()

2011-12-07T18:29:04+00:00

Signed-off-by: Djalal Harouni 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2011-10-24T22:18:09+00:00