Commit Graph

25 Commits

Author SHA1 Message Date
Greg Kroah-Hartman 3adcfa4478 l2tp: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Also, there is no need to store the individual debugfs file name, just
remove the whole directory all at once, saving a local variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14 08:45:05 -07:00
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Guillaume Nault e9697e2eff l2tp: ignore L2TP_ATTR_MTU
This attribute's handling is broken. It can only be used when creating
Ethernet pseudo-wires, in which case its value can be used as the
initial MTU for the l2tpeth device.
However, when handling update requests, L2TP_ATTR_MTU only modifies
session->mtu. This value is never propagated to the l2tpeth device.
Dump requests also return the value of session->mtu, which is not
synchronised anymore with the device MTU.

The same problem occurs if the device MTU is properly updated using the
generic IFLA_MTU attribute. In this case, session->mtu is not updated,
and L2TP_ATTR_MTU will report an invalid value again when dumping the
session.

It does not seem worthwhile to complexify l2tp_eth.c to synchronise
session->mtu with the device MTU. Even the ip-l2tp manpage advises to
use 'ip link' to initialise the MTU of l2tpeth devices (iproute2 does
not handle L2TP_ATTR_MTU at all anyway). So let's just ignore it
entirely.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 10:03:57 -07:00
Guillaume Nault 92ea4a7eec l2tp: drop ->mru from struct l2tp_session
This field is not used.

Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0,
while "set" requests vadidate the user supplied pointer but discard its
value.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault 3ae5536b80 l2tp: ignore L2TP_ATTR_DATA_SEQ netlink attribute
The value of this attribute is never used.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault c3612f0e90 l2tp: remove .show from struct l2tp_tunnel
This callback has never been implemented.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26 22:55:51 +09:00
Guillaume Nault 8349440733 l2tp: consistent reference counting in procfs and debufs
The 'pppol2tp' procfs and 'l2tp/tunnels' debugfs files handle reference
counting of sessions differently than for tunnels.

For consistency, use the same mechanism for handling both sessions and
tunnels. That is, drop the reference on the previous session just
before looking up the next one (rather than in .show()). If necessary
(if dump stops before *_next_session() returns NULL), drop the last
reference in .stop().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27 11:06:35 -04:00
Guillaume Nault 5411b6187a l2tp: fix {pppol2tp, l2tp_dfs}_seq_stop() in case of seq_file overflow
Commit 0e0c3fee3a ("l2tp: hold reference on tunnels printed in pppol2tp proc file")
assumed that if pppol2tp_seq_stop() was called with non-NULL private
data (the 'v' pointer), then pppol2tp_seq_start() would not be called
again. It turns out that this isn't guaranteed, and overflowing the
seq_file's buffer in pppol2tp_seq_show() is a way to get into this
situation.

Therefore, pppol2tp_seq_stop() needs to reset pd->tunnel, so that
pppol2tp_seq_start() won't drop a reference again if it gets called.
We also have to clear pd->session, because the rest of the code expects
a non-NULL tunnel when pd->session is set.

The l2tp_debugfs module has the same issue. Fix it in the same way.

Fixes: 0e0c3fee3a ("l2tp: hold reference on tunnels printed in pppol2tp proc file")
Fixes: f726214d9b ("l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-22 14:46:35 -04:00
Guillaume Nault f726214d9b l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file
Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe
against concurrent tunnel deletion.

Use the same mechanism as in l2tp_ppp.c for dropping the reference
taken by l2tp_tunnel_get_nth(). That is, drop the reference just
before looking up the next tunnel. In case of error, drop the last
accessed tunnel in l2tp_dfs_seq_stop().

That was the last use of l2tp_tunnel_find_nth().

Fixes: 0ad6614048 ("l2tp: Add debugfs files for dumping l2tp debug info")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-13 12:17:26 -04:00
Lorenzo Bianconi 9afa65857d l2tp: remove l2specific_len configurable parameter
Remove l2specific_len configuration parameter since now L2-Specific
Sublayer length is computed according to l2specific_type provided by
userspace.

Reviewed-by: Guillaume Nault <g.nault@alphalink.fr>
Tested-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19 15:00:49 -05:00
James Chapman 900631ee6a l2tp: remove configurable payload offset
If L2TP_ATTR_OFFSET is set to a non-zero value in L2TPv3 tunnels, it
results in L2TPv3 packets being transmitted which might not be
compliant with the L2TPv3 RFC. This patch has l2tp ignore the offset
setting and send all packets with no offset.

In more detail:

L2TPv2 supports a variable offset from the L2TPv2 header to the
payload. The offset value is indicated by an optional field in the
L2TP header.  Our L2TP implementation already detects the presence of
the optional offset and skips that many bytes when handling data
received packets. All transmitted packets are always transmitted with
no offset.

L2TPv3 has no optional offset field in the L2TPv3 packet
header. Instead, L2TPv3 defines optional fields in a "Layer-2 Specific
Sublayer". At the time when the original L2TP code was written, there
was talk at IETF of offset being implemented in a new Layer-2 Specific
Sublayer. A L2TP_ATTR_OFFSET netlink attribute was added so that this
offset could be configured and the intention was to allow it to be
also used to set the tx offset for L2TPv2. However, no L2TPv3 offset
was ever specified and the L2TP_ATTR_OFFSET parameter was forgotten
about.

Setting L2TP_ATTR_OFFSET results in L2TPv3 packets being transmitted
with the specified number of bytes padding between L2TPv3 header and
payload. This is not compliant with L2TPv3 RFC3931. This change
removes the configurable offset altogether while retaining
L2TP_ATTR_OFFSET for backwards compatibility. Any L2TP_ATTR_OFFSET
value is ignored.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05 11:03:19 -05:00
James Chapman 863def15b9 l2tp: revert "l2tp: add peer_offset parameter"
Revert commit f15bc54eee ("l2tp: add peer_offset parameter"). This
is removed because it is adding another configurable offset and
configurable offsets are being removed.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05 11:03:04 -05:00
Lorenzo Bianconi f15bc54eee l2tp: add peer_offset parameter
Introduce peer_offset parameter in order to add the capability
to specify two different values for payload offset on tx/rx side.
If just offset is provided by userspace use it for rx side as well
in order to maintain compatibility with older l2tp versions

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-27 12:11:51 -05:00
Guillaume Nault a4346210c4 l2tp: remove ->ref() and ->deref()
The ->ref() and ->deref() callbacks are unused since PPP stopped using
them in ee40fb2e1e ("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 <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01 10:57:24 +09:00
Reshetova, Elena fbea9e0760 net, l2tp: convert l2tp_tunnel.ref_count from atomic_t to refcount_t
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 <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04 22:35:15 +01:00
Reshetova, Elena 41c6d650f6 net: convert sock.sk_refcnt from atomic_t to refcount_t
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 <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 07:39:08 -07:00
Guillaume Nault e08293a4cc l2tp: take reference on sessions being dumped
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>
2017-04-04 10:00:56 -07:00
Eric Dumazet efe4208f47 ipv6: make lookups simpler and faster
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>
2013-10-09 00:01:25 -04:00
Tom Parkin 7b7c0719cd l2tp: avoid deadlock in l2tp stats update
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 <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20 12:10:39 -04:00
Joe Perches a4ca44fa57 net: l2tp: Standardize logging styles
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>
2012-05-17 04:34:38 -04:00
Chris Elston 2121c3f571 l2tp: show IPv6 addresses in l2tp debugfs file
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>
2012-05-01 09:30:55 -04:00
Al Viro b8f07a0631 fix return values of l2tp_dfs_seq_open()
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>
2011-06-05 14:11:09 -07:00
Dr. David Alan Gilbert 6f9b901823 l2tp: kzalloc with swapped params in l2tp_dfs_seq_open
'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>
2010-11-01 06:56:02 -07:00
Joe Perches a4fbf8415c net/l2tp/l2tp_debugfs.c: Convert NIPQUAD to %pI4
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-15 15:37:13 -07:00
James Chapman 0ad6614048 l2tp: Add debugfs files for dumping l2tp debug info
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>
2010-04-03 14:56:07 -07:00