Commit graph

28 commits

Author SHA1 Message Date
Tom Herbert
6b649feafe l2tp: Add support for zero IPv6 checksums
Added new L2TP configuration options to allow TX and RX of
zero checksums in IPv6. Default is not to use them.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-23 16:28:53 -04:00
Guillaume Nault
bb5016eac1 l2tp: fix manual sequencing (de)activation in L2TPv2
Commit e0d4435f "l2tp: Update PPP-over-L2TP driver to work over L2TPv3"
broke the PPPOL2TP_SO_SENDSEQ setsockopt. The L2TP header length was
previously computed by pppol2tp_l2t_header_len() before each call to
l2tp_xmit_skb(). Now that header length is retrieved from the hdr_len
session field, this field must be updated every time the L2TP header
format is modified, or l2tp_xmit_skb() won't push the right amount of
data for the L2TP header.

This patch uses l2tp_session_set_header_len() to adjust hdr_len every
time sequencing is (de)activated from userspace (either by the
PPPOL2TP_SO_SENDSEQ setsockopt or the L2TP_ATTR_SEND_SEQ netlink
attribute).

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06 14:25:39 -05:00
stephen hemminger
b5d2b2858f l2tp: make local functions static
Avoid needless export of local functions

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-13 12:00:16 -08:00
Joe Perches
c1b1203d65 net: misc: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19 19:12:11 -04:00
François Cachereul
e18503f41f l2tp: fix kernel panic when using IPv4-mapped IPv6 addresses
IPv4 mapped addresses cause kernel panic.
The patch juste check whether the IPv6 address is an IPv4 mapped
address. If so, use IPv4 API instead of IPv6.

[  940.026915] general protection fault: 0000 [#1]
[  940.026915] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppox ppp_generic slhc loop psmouse
[  940.026915] CPU: 0 PID: 3184 Comm: memcheck-amd64- Not tainted 3.11.0+ #1
[  940.026915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[  940.026915] task: ffff880007130e20 ti: ffff88000737e000 task.ti: ffff88000737e000
[  940.026915] RIP: 0010:[<ffffffff81333780>]  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915] RSP: 0018:ffff88000737fd28  EFLAGS: 00010286
[  940.026915] RAX: c748521a75ceff48 RBX: ffff880000c30800 RCX: 0000000000000000
[  940.026915] RDX: ffff88000075cc4e RSI: 0000000000000028 RDI: ffff8800060e5a40
[  940.026915] RBP: ffff8800060e5a40 R08: 0000000000000000 R09: ffff88000075cc90
[  940.026915] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88000737fda0
[  940.026915] R13: 0000000000000000 R14: 0000000000002000 R15: ffff880005d3b580
[  940.026915] FS:  00007f163dc5e800(0000) GS:ffffffff81623000(0000) knlGS:0000000000000000
[  940.026915] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  940.026915] CR2: 00000004032dc940 CR3: 0000000005c25000 CR4: 00000000000006f0
[  940.026915] Stack:
[  940.026915]  ffff88000075cc4e ffffffff81694e90 ffff880000c30b38 0000000000000020
[  940.026915]  11000000523c4bac ffff88000737fdb4 0000000000000000 ffff880000c30800
[  940.026915]  ffff880005d3b580 ffff880000c30b38 ffff8800060e5a40 0000000000000020
[  940.026915] Call Trace:
[  940.026915]  [<ffffffff81356cc3>] ? inet6_csk_xmit+0xa4/0xc4
[  940.026915]  [<ffffffffa0038535>] ? l2tp_xmit_skb+0x503/0x55a [l2tp_core]
[  940.026915]  [<ffffffff812b8d3b>] ? pskb_expand_head+0x161/0x214
[  940.026915]  [<ffffffffa003e91d>] ? pppol2tp_xmit+0xf2/0x143 [l2tp_ppp]
[  940.026915]  [<ffffffffa00292e0>] ? ppp_channel_push+0x36/0x8b [ppp_generic]
[  940.026915]  [<ffffffffa00293fe>] ? ppp_write+0xaf/0xc5 [ppp_generic]
[  940.026915]  [<ffffffff8110ead4>] ? vfs_write+0xa2/0x106
[  940.026915]  [<ffffffff8110edd6>] ? SyS_write+0x56/0x8a
[  940.026915]  [<ffffffff81378ac0>] ? system_call_fastpath+0x16/0x1b
[  940.026915] Code: 00 49 8b 8f d8 00 00 00 66 83 7c 11 02 00 74 60 49
8b 47 58 48 83 e0 fe 48 8b 80 18 01 00 00 48 85 c0 74 13 48 8b 80 78 02
00 00 <48> ff 40 28 41 8b 57 68 48 01 50 30 48 8b 54 24 08 49 c7 c1 51
[  940.026915] RIP  [<ffffffff81333780>] ip6_xmit+0x276/0x326
[  940.026915]  RSP <ffff88000737fd28>
[  940.057945] ---[ end trace be8aba9a61c8b7f3 ]---
[  940.058583] Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: François CACHEREUL <f.cachereul@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-02 17:09:22 -04:00
James Chapman
a0dbd82227 l2tp: make datapath resilient to packet loss when sequence numbers enabled
If L2TP data sequence numbers are enabled and reordering is not
enabled, data reception stops if a packet is lost since the kernel
waits for a sequence number that is never resent. (When reordering is
enabled, data reception restarts when the reorder timeout expires.) If
no reorder timeout is set, we should count the number of in-sequence
packets after the out-of-sequence (OOS) condition is detected, and reset
sequence number state after a number of such packets are received.

For now, the number of in-sequence packets while in OOS state which
cause the sequence number state to be reset is hard-coded to 5. This
could be configurable later.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02 16:33:25 -07:00
James Chapman
8a1631d588 l2tp: make datapath sequence number support RFC-compliant
The L2TP datapath is not currently RFC-compliant when sequence numbers
are used in L2TP data packets. According to the L2TP RFC, any received
sequence number NR greater than or equal to the next expected NR is
acceptable, where the "greater than or equal to" test is determined by
the NR wrap point. This differs for L2TPv2 and L2TPv3, so add state in
the session context to hold the max NR value and the NR window size in
order to do the acceptable sequence number value check. These might be
configurable later, but for now we derive it from the tunnel L2TP
version, which determines the sequence number field size.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02 16:33:24 -07:00
Tom Parkin
f6e16b299b l2tp: unhash l2tp sessions on delete, not on free
If we postpone unhashing of l2tp sessions until the structure is freed, we
risk:

 1. further packets arriving and getting queued while the pseudowire is being
    closed down
 2. the recv path hitting "scheduling while atomic" errors in the case that
    recv drops the last reference to a session and calls l2tp_session_free
    while in atomic context

As such, l2tp sessions should be unhashed from l2tp_core data structures early
in the teardown process prior to calling pseudowire close.  For pseudowires
like l2tp_ppp which have multiple shutdown codepaths, provide an unhash hook.

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
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
Tom Parkin
48f72f92b3 l2tp: add session reorder queue purge function to core
If an l2tp session is deleted, it is necessary to delete skbs in-flight
on the session's reorder queue before taking it down.

Rather than having each pseudowire implementation reaching into the
l2tp_session struct to handle this itself, provide a function in l2tp_core to
purge the session queue.

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
Tom Parkin
e34f4c7050 l2tp: export l2tp_tunnel_closeall
l2tp_core internally uses l2tp_tunnel_closeall to close all sessions in a
tunnel when a UDP-encapsulation socket is destroyed.  We need to do something
similar for IP-encapsulation sockets.

Export l2tp_tunnel_closeall as a GPL symbol to enable l2tp_ip and l2tp_ip6 to
call it from their .destroy handlers.

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 12:10:38 -04:00
Tom Parkin
f8ccac0e44 l2tp: put tunnel socket release on a workqueue
To allow l2tp_tunnel_delete to be called from an atomic context, place the
tunnel socket release calls on a workqueue for asynchronous execution.

Tunnel memory is eventually freed in the tunnel socket destructor.

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>
2013-02-05 14:20:30 -05:00
Tom Parkin
80d84ef3ff l2tp: prevent l2tp_tunnel_delete racing with userspace close
If a tunnel socket is created by userspace, l2tp hooks the socket destructor
in order to clean up resources if userspace closes the socket or crashes.  It
also caches a pointer to the struct sock for use in the data path and in the
netlink interface.

While it is safe to use the cached sock pointer in the data path, where the
skb references keep the socket alive, it is not safe to use it elsewhere as
such access introduces a race with userspace closing the socket.  In
particular, l2tp_tunnel_delete is prone to oopsing if a multithreaded
userspace application closes a socket at the same time as sending a netlink
delete command for the tunnel.

This patch fixes this oops by forcing l2tp_tunnel_delete to explicitly look up
a tunnel socket held by userspace using sockfd_lookup().

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>
2013-01-29 15:43:02 -05:00
xeb@mail.ru
99469c32f7 l2tp: avoid to use synchronize_rcu in tunnel free function
Avoid to use synchronize_rcu in l2tp_tunnel_free because context may be
atomic.

Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-30 12:31:03 -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
James Chapman
38d40b3f4e l2tp: fix reorder timeout recovery
When L2TP data packet reordering is enabled, packets are held in a
queue while waiting for out-of-sequence packets. If a packet gets
lost, packets will be held until the reorder timeout expires, when we
are supposed to then advance to the sequence number of the next packet
but we don't currently do so. As a result, the data channel is stuck
because we are waiting for a packet that will never arrive - all
packets age out and none are passed.

The fix is to add a flag to the session context, which is set when the
reorder timeout expires and tells the receive code to reset the next
expected sequence number to that of the next packet in the queue.

Tested in a production L2TP network with Starent and Nortel L2TP gear.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10 23:27:34 -04:00
Chris Elston
f9bac8df90 l2tp: netlink api for l2tpv3 ipv6 unmanaged tunnels
This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using
the netlink API. We already support unmanaged L2TPv3 tunnels over
IPv4. A patch to iproute2 to make use of this feature will be
submitted separately.

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
James Chapman
5de7aee541 l2tp: fix locking of 64-bit counters for smp
L2TP uses 64-bit counters but since these are not updated atomically,
we need to make them safe for smp. This patch addresses that.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01 09:30:54 -04:00
Eric Dumazet
95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
stephen hemminger
fc130840d7 l2tp: make local function static
Also moved the refcound inlines from l2tp_core.h to l2tp_core.c
since only used in that one file.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-24 14:55:47 -07:00
Eric Dumazet
7bddd0db62 l2tp: unmanaged L2TPv3 tunnels fixes
Followup to commit 789a4a2c 
(l2tp: Add support for static unmanaged L2TPv3 tunnels)

One missing init in l2tp_tunnel_sock_create() could access random kernel
memory, and a bit field should be unsigned.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-04 01:02:46 -07:00
David S. Miller
f66ef2d064 l2tp: Fix L2TP_DEBUGFS ifdef tests.
We have to check CONFIG_L2TP_DEBUGFS_MODULE as well as
CONFIG_L2TP_DEBUGFS.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 15:01:37 -07:00
James Chapman
789a4a2c61 l2tp: Add support for static unmanaged L2TPv3 tunnels
This patch adds support for static (unmanaged) L2TPv3 tunnels, where
the tunnel socket is created by the kernel rather than being created
by userspace. This means L2TP tunnels and sessions can be created
manually, without needing an L2TP control protocol implemented in
userspace. This might be useful where the user wants a simple ethernet
over IP tunnel.

A patch to iproute2 adds a new command set under "ip l2tp" to make use
of this feature. This will be submitted separately.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:08 -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
James Chapman
309795f4be l2tp: Add netlink control API for L2TP
In L2TPv3, we need to create/delete/modify/query L2TP tunnel and
session contexts. The number of parameters is significant. So let's
use netlink. Userspace uses this API to control L2TP tunnel/session
contexts in the kernel.

The previous pppol2tp driver was managed using [gs]etsockopt(). This
API is retained for backwards compatibility. Unlike L2TPv2 which
carries only PPP frames, L2TPv3 can carry raw ethernet frames or other
frame types and these do not always have an associated socket
family. Therefore, we need a way to use L2TP sessions that doesn't
require a socket type for each supported frame type. Hence netlink is
used.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:05 -07:00
James Chapman
0d76751fad l2tp: Add L2TPv3 IP encapsulation (no UDP) support
This patch adds a new L2TPIP socket family and modifies the core to
handle the case where there is no UDP header in the L2TP
packet. L2TP/IP uses IP protocol 115. Since L2TP/UDP and L2TP/IP
packets differ in layout, the datapath packet handling code needs
changes too. Userspace uses an L2TPIP socket instead of a UDP socket
when IP encapsulation is required.

We can't use raw sockets for this because the semantics of raw sockets
don't lend themselves to the socket-per-tunnel model - we need to

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:04 -07:00
James Chapman
f7faffa3ff l2tp: Add L2TPv3 protocol support
The L2TPv3 protocol changes the layout of the L2TP packet
header. Tunnel and session ids change from 16-bit to 32-bit values,
data sequence numbers change from 16-bit to 24-bit values and PPP-specific
fields are moved into protocol-specific subheaders.

Although this patch introduces L2TPv3 protocol support, there are no
userspace interfaces to create L2TPv3 sessions yet.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:03 -07:00
James Chapman
fd558d186d l2tp: Split pppol2tp patch into separate l2tp and ppp parts
This patch splits the pppol2tp driver into separate L2TP and PPP parts
to prepare for L2TPv3 support. In L2TPv3, protocols other than PPP can
be carried, so this split creates a common L2TP core that will handle
the common L2TP bits which protocol support modules such as PPP will
use.

Note that the existing pppol2tp module is split into l2tp_core and
l2tp_ppp by this change.

There are no feature changes here. Internally, however, there are
significant changes, mostly to handle the separation of PPP-specific
data from the L2TP session and to provide hooks in the core for
modules like PPP to access.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:02 -07:00