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: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048 ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4be ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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=2http://marc.info/?l=linux-netdev&m=134079868111131&w=2
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use more current logging styles.
Add pr_fmt to prefix output appropriately.
Convert printks to pr_<level>.
Convert PRINTK macros to new l2tp_<level> macros.
Neaten some <foo>_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 <joe@perches.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If an L2TP tunnel uses IPv6, make sure the l2tp debugfs file shows the
IPv6 address correctly.
Signed-off-by: Chris Elston <celston@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <viro@zeniv.linux.org.uk>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'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 1792f17b72 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 <linux@treblig.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The existing pppol2tp driver exports debug info to
/proc/net/pppol2tp. Rather than adding info to that file for the new
functionality added in this patch series, we add new files in debugfs,
leaving the old /proc file for backwards compatibility (L2TPv2 only).
Currently only one file is provided: l2tp/tunnels, which lists
internal debug info for all l2tp tunnels and sessions. More files may
be added later. The info is for debug and problem analysis only -
userspace apps should use netlink to obtain status about l2tp tunnels
and sessions.
Although debugfs does not support net namespaces, the tunnels and
sessions dumped in l2tp/tunnels are only those in the net namespace of
the process reading the file.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
