Commit Graph

25 Commits

Author SHA1 Message Date
Johannes Berg 053c095a82 netlink: make nlmsg_end() and genlmsg_end() void
Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.

This makes the very common pattern of

  if (genlmsg_end(...) < 0) { ... }

be a whole bunch of dead code. Many places also simply do

  return nlmsg_end(...);

and the caller is expected to deal with it.

This also commonly (at least for me) causes errors, because it is very
common to write

  if (my_function(...))
    /* error condition */

and if my_function() does "return nlmsg_end()" this is of course wrong.

Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.

Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did

-	return nlmsg_end(...);
+	nlmsg_end(...);
+	return 0;

I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with <= 0 in dump functionality, but that could just
be changed to < 0 with no change in behaviour, so I opted for the more
efficient version.

One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for <0 or <=0 and thus broke out of the loop every single time.
I've preserved this since it will (I think) have caused the messages to
userspace to be formatted differently with just a single message for
every SKB returned to userspace. It's possible that this isn't needed
for the tools that actually use this, but I don't even know what they
are so couldn't test that changing this behaviour would be acceptable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18 01:03:45 -05:00
Jeremiah Mahler 069f8457ae can: fix spelling errors
Fix various spelling errors in the comments of the CAN modules.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-12-07 21:22:05 +01:00
Eric W. Biederman 90f62cf30a net: Use netlink_ns_capable to verify the permisions of netlink messages
It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 13:44:54 -04:00
Ying Xue 5af28de353 can: use __dev_get_by_index instead of dev_get_by_index to find interface
As cgw_create_job() is always under rtnl_lock protection,
__dev_get_by_index() instead of dev_get_by_index() should be used to
find interface handler in it having us avoid to change interface
reference counter.

Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14 18:50:47 -08:00
Oliver Hartkopp c0ebbdd6b5 can: gw: remove obsolete checks
In commit be286bafe1 ("can: gw: add a variable
limit for CAN frame routings") the detection of the frame routing has been
changed. The former solution required dev->header_ops to be unused (== NULL).

I missed to remove the obsolete checks in the original commit - so here it is.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-12-21 14:56:21 +01:00
Oliver Hartkopp 391ac1282d can: gw: add a per rule limitation of frame hops
Usually the received CAN frames can be processed/routed as much as 'max_hops'
times (which is given at module load time of the can-gw module).
Introduce a new configuration option to reduce the number of possible hops
for a specific gateway rule to a value smaller then max_hops.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-08-29 22:58:24 +02:00
Jiri Pirko 351638e7de net: pass info struct via netdevice notifier
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-28 13:11:01 -07:00
David S. Miller 6e0895c2ea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be_main.c
	drivers/net/ethernet/intel/igb/igb_main.c
	drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
	include/net/scm.h
	net/batman-adv/routing.c
	net/ipv4/tcp_input.c

The e{uid,gid} --> {uid,gid} credentials fix conflicted with the
cleanup in net-next to now pass cred structs around.

The be2net driver had a bug fix in 'net' that overlapped with the VLAN
interface changes by Patrick McHardy in net-next.

An IGB conflict existed because in 'net' the build_skb() support was
reverted, and in 'net-next' there was a comment style fix within that
code.

Several batman-adv conflicts were resolved by making sure that all
calls to batadv_is_my_mac() are changed to have a new bat_priv first
argument.

Eric Dumazet's TS ECR fix in TCP in 'net' conflicted with the F-RTO
rewrite in 'net-next', mostly overlapping changes.

Thanks to Stephen Rothwell and Antonio Quartulli for help with several
of these merge resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22 20:32:51 -04:00
Wei Yongjun 3480a21259 can: gw: use kmem_cache_free() instead of kfree()
Memory allocated by kmem_cache_alloc() should be freed using
kmem_cache_free(), not kfree().

Cc: linux-stable <stable@vger.kernel.org> # >= v3.2
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-04-09 09:58:44 +02:00
Thomas Graf 661d2967b3 rtnetlink: Remove passing of attributes into rtnl_doit functions
With decnet converted, we can finally get rid of rta_buf and its
computations around it. It also gets rid of the minimal header
length verification since all message handlers do that explicitly
anyway.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-22 10:31:16 -04:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Oliver Hartkopp 2bf3440d7b can: rework skb reserved data handling
Added accessor and skb_reserve helpers for struct can_skb_priv.
Removed pointless skb_headroom() check.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
CC: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-28 18:17:25 -05:00
Oliver Hartkopp e6afa00a14 can: gw: indicate and count deleted frames due to misconfiguration
Add a statistic counter to detect deleted frames due to misconfiguration with
a new read-only CGW_DELETED netlink attribute for the CAN gateway.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 16:59:02 +01:00
Oliver Hartkopp be286bafe1 can: gw: add a variable limit for CAN frame routings
To prevent a possible misconfiguration (e.g. circular CAN frame routings)
limit the number of routings of a single CAN frame to a small variable value.

The limit can be specified by the module parameter 'max_hops' (1..6).
The default value is 1 (one hop), according to the original can-gw behaviour.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 16:59:01 +01:00
Oliver Hartkopp d904d3edcb can: gw: make routing to the incoming CAN interface configurable
Introduce new configuration flag CGW_FLAGS_CAN_IIF_TX_OK to configure if a
CAN sk_buff that has been routed with can-gw is allowed to be send back to
the originating CAN interface.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 16:59:01 +01:00
Eric W. Biederman dfc47ef863 net: Push capable(CAP_NET_ADMIN) into the rtnl methods
- In rtnetlink_rcv_msg convert the capable(CAP_NET_ADMIN) check
  to ns_capable(net->user-ns, CAP_NET_ADMIN).  Allowing unprivileged
  users to make netlink calls to modify their local network
  namespace.

- In the rtnetlink doit methods add capable(CAP_NET_ADMIN) so
  that calls that are not safe for unprivileged users are still
  protected.

Later patches will remove the extra capable calls from methods
that are safe for unprivilged users.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-18 20:32:44 -05:00
Andi Kleen 6299b669b1 sections: fix section conflicts in net/can
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:45 +09:00
Eric W. Biederman 15e473046c netlink: Rename pid to portid to avoid confusion
It is a frequent mistake to confuse the netlink port identifier with a
process identifier.  Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-10 15:30:41 -04:00
Thomas Graf 5d91efa8dd can: gw: Remove pointless casts
No need to cast return value of nla_data()

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-07-10 22:36:17 +02:00
Thomas Graf 1da0faa380 can: gw: Properly fill the netlink header when responding to RTM_GETROUTE
- set message type to RTM_NEWROUTE
 - relate to original request by inheriting the sequence and port number.
 - set NLM_F_MULTI because it's a dump and more messages will follow

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-07-10 22:36:01 +02:00
Thomas Graf 732d35fd08 can: gw: Use nla_policy to validate netlink attributes
Also use nla_get_u32() instead of nla_memcpy() to access u32 attribtues.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-07-10 22:35:41 +02:00
Thomas Graf 6eaf53ca7b can: gw: Don't bump nlmsg_len manually
nlmsg_end() will take care of this when we finalize the message.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-07-10 22:33:40 +02:00
Daniel Baluta a75afd4770 can: fix sparse warning for cgw_list
Make cgw_list static to remove the following sparse warning:
net/can/gw.c:69:1: warning: symbol 'cgw_list' was not declared.
Should it be static?

Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-04-16 21:08:18 +02:00
Marc Kleine-Budde f861c2b80c can: remove references to berlios mailinglist
The BerliOS project, which currently hosts our mailinglist, will
close with the end of the year. Now take the chance and remove all
occurrences of the mailinglist address from the source files.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-17 19:22:46 -04:00
Oliver Hartkopp c1aabdf379 can-gw: add netlink based CAN routing
This patch adds a CAN Gateway/Router to route (and modify) CAN frames.

It is based on the PF_CAN core infrastructure for msg filtering and msg
sending and can optionally modify routed CAN frames on the fly.
CAN frames can *only* be routed between CAN network interfaces (one hop).
They can be modified with AND/OR/XOR/SET operations as configured by the
netlink configuration interface known e.g. from iptables. From the netlink
view this can-gw implements RTM_{NEW|DEL|GET}ROUTE for PF_CAN.

The CAN specific userspace tool to manage CAN routing entries can be found in
the CAN utils http://svn.berlios.de/wsvn/socketcan/trunk/can-utils/cangw.c
at the SocketCAN SVN on BerliOS.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16 17:37:51 -04:00