linux.git/net/l2tp/l2tp_debugfs.c, branch v4.15

l2tp: remove ->ref() and ->deref()

2017-11-01T01:57:24+00:00

The ->ref() and ->deref() callbacks are unused since PPP stopped using
them in ee40fb2e1eb5 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU").

We can thus remove them from struct l2tp_session and drop the do_ref
parameter of l2tp_session_get*().

Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

net, l2tp: convert l2tp_tunnel.ref_count from atomic_t to refcount_t

2017-07-04T21:35:15+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

net: convert sock.sk_refcnt from atomic_t to refcount_t

2017-07-01T14:39:08+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

l2tp: take reference on sessions being dumped

2017-04-04T17:00:56+00:00

Take a reference on the sessions returned by l2tp_session_find_nth()
(and rename it l2tp_session_get_nth() to reflect this change), so that
caller is assured that the session isn't going to disappear while
processing it.

For procfs and debugfs handlers, the session is held in the .start()
callback and dropped in .show(). Given that pppol2tp_seq_session_show()
dereferences the associated PPPoL2TP socket and that
l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to
call the session's .ref() callback to prevent the socket from going
away from under us.

Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

ipv6: make lookups simpler and faster

2013-10-09T04:01:25+00:00

TCP listener refactoring, part 4 :

To speed up inet lookups, we moved IPv4 addresses from inet to struct
sock_common

Now is time to do the same for IPv6, because it permits us to have fast
lookups for all kind of sockets, including upcoming SYN_RECV.

Getting IPv6 addresses in TCP lookups currently requires two extra cache
lines, plus a dereference (and memory stall).

inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6

This patch is way bigger than its IPv4 counter part, because for IPv4,
we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6,
it's not doable easily.

inet6_sk(sk)->daddr becomes sk->sk_v6_daddr
inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr

And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr
at the same offset.

We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic
macro.

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

l2tp: avoid deadlock in l2tp stats update

2013-03-20T16:10:39+00:00

l2tp's u64_stats writers were incorrectly synchronised, making it possible to
deadlock a 64bit machine running a 32bit kernel simply by sending the l2tp
code netlink commands while passing data through l2tp sessions.

Previous discussion on netdev determined that alternative solutions such as
spinlock writer synchronisation or per-cpu data would bring unjustified
overhead, given that most users interested in high volume traffic will likely
be running 64bit kernels on 64bit hardware.

As such, this patch replaces l2tp's use of u64_stats with atomic_long_t,
thereby avoiding the deadlock.

Ref:
http://marc.info/?l=linux-netdev&m=134029167910731&w=2
http://marc.info/?l=linux-netdev&m=134079868111131&w=2

Signed-off-by: Tom Parkin 
Signed-off-by: James Chapman 
Signed-off-by: David S. Miller

net: l2tp: Standardize logging styles

2012-05-17T08:34:38+00:00

Use more current logging styles.

Add pr_fmt to prefix output appropriately.
Convert printks to pr_.
Convert PRINTK macros to new l2tp_ macros.
Neaten some _refcount debugging macros.
Use print_hex_dump_bytes instead of hand-coded loops.
Coalesce formats and align arguments.

Some KERN_DEBUG output is not now emitted unless
dynamic_debugging is enabled.

Signed-off-by: Joe Perches 
Signed-off-by: James Chapman 
Signed-off-by: David S. Miller

l2tp: show IPv6 addresses in l2tp debugfs file

2012-05-01T13:30:55+00:00

If an L2TP tunnel uses IPv6, make sure the l2tp debugfs file shows the
IPv6 address correctly.

Signed-off-by: Chris Elston 
Signed-off-by: James Chapman 
Signed-off-by: David S. Miller

fix return values of l2tp_dfs_seq_open()

2011-06-05T21:11:09+00:00

More fallout from struct net lifetime rules review: PTR_ERR() is *already*
negative and failing ->open() should return negatives on failure.

Signed-off-by: Al Viro 
Signed-off-by: James Chapman 
Signed-off-by: David S. Miller

l2tp: kzalloc with swapped params in l2tp_dfs_seq_open

2010-11-01T13:56:02+00:00

  'sparse' spotted that the parameters to kzalloc in l2tp_dfs_seq_open
were swapped.

Tested on current git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
at 1792f17b7210280a3d7ff29da9614ba779cfcedb  build, boots and I can see that directory,
but there again I could see /sys/kernel/debug/l2tp with it swapped; I don't have
any l2tp in use.

Signed-off-by: Dr. David Alan Gilbert 
Signed-off-by: David S. Miller