linux.git/net/l2tp, branch v5.10

genetlink: move to smaller ops wherever possible

2020-10-03T02:11:11+00:00

Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski 
Reviewed-by: Johannes Berg 
Signed-off-by: David S. Miller

l2tp: report rx cookie discards in netlink get

2020-09-29T20:26:36+00:00

When an L2TPv3 session receives a data frame with an incorrect cookie
l2tp_core logs a warning message and bumps a stats counter to reflect
the fact that the packet has been dropped.

However, the stats counter in question is missing from the l2tp_netlink
get message for tunnel and session instances.

Include the statistic in the netlink get response.

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

l2tp: fix up inconsistent rx/tx statistics

2020-09-18T21:36:54+00:00

Historically L2TP core statistics count the L2TP header in the
per-session and per-tunnel byte counts tracked for transmission and
receipt.

Now that l2tp_xmit_skb updates tx stats, it is necessary for
l2tp_xmit_core to pass out the length of the transmitted packet so that
the statistics can be updated correctly.

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

l2tp: avoid duplicated code in l2tp_tunnel_closeall

2020-09-03T19:19:03+00:00

l2tp_tunnel_closeall is called as a part of tunnel shutdown in order to
close all the sessions held by the tunnel.  The code it uses to close a
session duplicates what l2tp_session_delete does.

Rather than duplicating the code, have l2tp_tunnel_closeall call
l2tp_session_delete instead.

This involves a very minor change to locking in l2tp_tunnel_closeall.
Previously, l2tp_tunnel_closeall checked the session "dead" flag while
holding tunnel->hlist_lock.  This allowed for the code to step to the
next session in the list without releasing the lock if the current
session happened to be in the process of closing already.

By calling l2tp_session_delete instead, l2tp_tunnel_closeall must now
drop and regain the hlist lock for each session in the tunnel list.
Given that the likelihood of a session being in the process of closing
when the tunnel is closed, it seems worth this very minor potential
loss of efficiency to avoid duplication of the session delete code.

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

l2tp: make magic feather checks more useful

2020-09-03T19:19:03+00:00

The l2tp tunnel and session structures contain a "magic feather" field
which was originally intended to help trace lifetime bugs in the code.

Since the introduction of the shared kernel refcount code in refcount.h,
and l2tp's porting to those APIs, we are covered by the refcount code's
checks and warnings.  Duplicating those checks in the l2tp code isn't
useful.

However, magic feather checks are still useful to help to detect bugs
stemming from misuse/trampling of the sk_user_data pointer in struct
sock.  The l2tp code makes extensive use of sk_user_data to stash
pointers to the tunnel and session structures, and if another subsystem
overwrites sk_user_data it's important to detect this.

As such, rework l2tp's magic feather checks to focus on validating the
tunnel and session data structures when they're extracted from
sk_user_data.

 * Add a new accessor function l2tp_sk_to_tunnel which contains a magic
   feather check, and is used by l2tp_core and l2tp_ip[6]
 * Comment l2tp_udp_encap_recv which doesn't use this new accessor function
   because of the specific nature of the codepath it is called in
 * Drop l2tp_session_queue_purge's check on the session magic feather:
   it is called from code which is walking the tunnel session list, and
   hence doesn't need validation
 * Drop l2tp_session_free's check on the tunnel magic feather: the
   intention of this check is covered by refcount.h's reference count
   sanity checking
 * Add session magic validation in pppol2tp_ioctl.  On failure return
   -EBADF, which mirrors the approach in pppol2tp_[sg]etsockopt.

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

l2tp: capture more tx errors in data plane stats

2020-09-03T19:19:03+00:00

l2tp_xmit_skb has a number of failure paths which are not reflected in
the tunnel and session statistics because the stats are updated by
l2tp_xmit_core.  Hence any errors occurring before l2tp_xmit_core is
called are missed from the statistics.

Refactor the transmit path slightly to capture all error paths.

l2tp_xmit_skb now leaves all the actual work of transmission to
l2tp_xmit_core, and updates the statistics based on l2tp_xmit_core's
return code.

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

l2tp: drop net argument from l2tp_tunnel_create

2020-09-03T19:19:03+00:00

The argument is unused, so remove it.

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

l2tp: drop data_len argument from l2tp_xmit_core

2020-09-03T19:19:03+00:00

The data_len argument passed to l2tp_xmit_core is no longer used, so
remove it.

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

l2tp: remove header length param from l2tp_xmit_skb

2020-09-03T19:19:03+00:00

All callers pass the session structure's hdr_len field as the header
length parameter to l2tp_xmit_skb.

Since we're passing a pointer to the session structure to l2tp_xmit_skb
anyway, there's not much point breaking the header length out as a
separate argument.

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

l2tp: remove tunnel and session debug flags field

2020-08-22T19:44:37+00:00

The l2tp subsystem now uses standard kernel logging APIs for
informational and warning messages, and tracepoints for debug
information.

Now that the tunnel and session debug flags are unused, remove the field
from the core structures.

Various system calls (in the case of l2tp_ppp) and netlink messages
handle the getting and setting of debug flags.  To avoid userspace
breakage don't modify the API of these calls; simply ignore set
requests, and send dummy data for get requests.

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