linux-toradex.git/include/net/lwtunnel.h, branch v4.9.17

lwtunnel: valid encap attr check should return 0 when lwtunnel is disabled

2017-02-18T14:11:42+00:00

[ Upstream commit 2bd137de531367fb573d90150d1872cb2a2095f7 ]

An error was reported upgrading to 4.9.8:
    root@Typhoon:~# ip route add default table 210 nexthop dev eth0 via 10.68.64.1
    weight 1 nexthop dev eth0 via 10.68.64.2 weight 1
    RTNETLINK answers: Operation not supported

The problem occurs when CONFIG_LWTUNNEL is not enabled and a multipath
route is submitted.

The point of lwtunnel_valid_encap_type_attr is catch modules that
need to be loaded before any references are taken with rntl held. With
CONFIG_LWTUNNEL disabled, there will be no modules to load so the
lwtunnel_valid_encap_type_attr stub should just return 0.

Fixes: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules")
Reported-by: pupilla@libero.it
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

lwtunnel: Fix oops on state free after encap module unload

2017-02-04T08:47:11+00:00

[ Upstream commit 85c814016ce3b371016c2c054a905fa2492f5a65 ]

When attempting to free lwtunnel state after the module for the encap
has been unloaded an oops occurs:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: lwtstate_free+0x18/0x40
[..]
task: ffff88003e372380 task.stack: ffffc900001fc000
RIP: 0010:lwtstate_free+0x18/0x40
RSP: 0018:ffff88003fd83e88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88002bbb3380 RCX: ffff88000c91a300
[..]
Call Trace:
 
 free_fib_info_rcu+0x195/0x1a0
 ? rt_fibinfo_free+0x50/0x50
 rcu_process_callbacks+0x2d3/0x850
 ? rcu_process_callbacks+0x296/0x850
 __do_softirq+0xe4/0x4cb
 irq_exit+0xb0/0xc0
 smp_apic_timer_interrupt+0x3d/0x50
 apic_timer_interrupt+0x93/0xa0
[..]
Code: e8 6e c6 fc ff 89 d8 5b 5d c3 bb de ff ff ff eb f4 66 90 66 66 66 66 90 55 48 89 e5 53 0f b7 07 48 89 fb 48 8b 04 c5 00 81 d5 81 <48> 8b 40 08 48 85 c0 74 13 ff d0 48 8d 7b 20 be 20 00 00 00 e8

The problem is after the module for the encap can be unloaded the
corresponding ops is removed and is thus NULL here.

Modules implementing lwtunnel ops should not be allowed to unload
while there is state alive using those ops, so grab the module
reference for the ops on creating lwtunnel state and of course release
the reference when freeing the state.

Fixes: 1104d9ba443a ("lwtunnel: Add destroy state operation")
Signed-off-by: Robert Shearman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Specify the owning module for lwtunnel ops

2017-02-04T08:47:11+00:00

[ Upstream commit 88ff7334f25909802140e690c0e16433e485b0a0 ]

Modules implementing lwtunnel ops should not be allowed to unload
while there is state alive using those ops, so specify the owning
module for all lwtunnel ops.

Signed-off-by: Robert Shearman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

lwtunnel: fix autoload of lwt modules

2017-02-04T08:47:10+00:00

[ Upstream commit 9ed59592e3e379b2e9557dc1d9e9ec8fcbb33f16]

Trying to add an mpls encap route when the MPLS modules are not loaded
hangs. For example:

    CONFIG_MPLS=y
    CONFIG_NET_MPLS_GSO=m
    CONFIG_MPLS_ROUTING=m
    CONFIG_MPLS_IPTUNNEL=m

    $ ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2

The ip command hangs:
root       880   826  0 21:25 pts/0    00:00:00 ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2

    $ cat /proc/880/stack
    [] call_usermodehelper_exec+0xd6/0x134
    [] __request_module+0x27b/0x30a
    [] lwtunnel_build_state+0xe4/0x178
    [] fib_create_info+0x47f/0xdd4
    [] fib_table_insert+0x90/0x41f
    [] inet_rtm_newroute+0x4b/0x52
    ...

modprobe is trying to load rtnl-lwt-MPLS:

root       881     5  0 21:25 ?        00:00:00 /sbin/modprobe -q -- rtnl-lwt-MPLS

and it hangs after loading mpls_router:

    $ cat /proc/881/stack
    [] rtnl_lock+0x12/0x14
    [] register_netdevice_notifier+0x16/0x179
    [] mpls_init+0x25/0x1000 [mpls_router]
    [] do_one_initcall+0x8e/0x13f
    [] do_init_module+0x5a/0x1e5
    [] load_module+0x13bd/0x17d6
    ...

The problem is that lwtunnel_build_state is called with rtnl lock
held preventing mpls_init from registering.

Given the potential references held by the time lwtunnel_build_state it
can not drop the rtnl lock to the load module. So, extract the module
loading code from lwtunnel_build_state into a new function to validate
the encap type. The new function is called while converting the user
request into a fib_config which is well before any table, device or
fib entries are examined.

Fixes: 745041e2aaf1 ("lwtunnel: autoload of lwt modules")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: lwtunnel: Handle fragmentation

2016-08-31T05:27:18+00:00

Today mpls iptunnel lwtunnel_output redirect expects the tunnel
output function to handle fragmentation. This is ok but can be
avoided if we did not do the mpls output redirect too early.
ie we could wait until ip fragmentation is done and then call
mpls output for each ip fragment.

To make this work we will need,
1) the lwtunnel state to carry encap headroom
2) and do the redirect to the encap output handler on the ip fragment
(essentially do the output redirect after fragmentation)

This patch adds tunnel headroom in lwtstate to make sure we
account for tunnel data in mtu calculations during fragmentation
and adds new xmit redirect handler to redirect to lwtunnel xmit func
after ip fragmentation.

This includes IPV6 and some mtu fixes and testing from David Ahern.

Signed-off-by: Roopa Prabhu 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

lwtunnel: autoload of lwt modules

2016-02-22T03:00:28+00:00

The lwt implementations using net devices can autoload using the
existing mechanism using IFLA_INFO_KIND. However, there's no mechanism
that lwt modules not using net devices can use.

Therefore, add the ability to autoload modules registering lwt
operations for lwt implementations not using a net device so that
users don't have to manually load the modules.

Only users with the CAP_NET_ADMIN capability can cause modules to be
loaded, which is ensured by rtnetlink_rcv_msg rejecting non-RTM_GETxxx
messages for users without this capability, and by
lwtunnel_build_state not being called in response to RTM_GETxxx
messages.

Signed-off-by: Robert Shearman 
Signed-off-by: David S. Miller

dst: Pass net into dst->output

2015-10-08T11:27:03+00:00

The network namespace is already passed into dst_output pass it into
dst->output lwt->output and friends.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

lwt: Add cfg argument to build_state

2015-08-24T17:34:40+00:00

Add cfg and family arguments to lwt build state functions. cfg is a void
pointer and will either be a pointer to a fib_config or fib6_config
structure. The family parameter indicates which one (either AF_INET
or AF_INET6).

LWT encpasulation implementation may use the fib configuration to build
the LWT state.

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

route: move lwtunnel state to dst_entry

2015-08-20T22:42:36+00:00

Currently, the lwtunnel state resides in per-protocol data. This is
a problem if we encapsulate ipv6 traffic in an ipv4 tunnel (or vice versa).
The xmit function of the tunnel does not know whether the packet has been
routed to it by ipv4 or ipv6, yet it needs the lwtstate data. Moving the
lwtstate data to dst_entry makes such inter-protocol tunneling possible.

As a bonus, this brings a nice diffstat.

Signed-off-by: Jiri Benc 
Acked-by: Roopa Prabhu 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller

lwtunnel: Fix the sparse warnings in fib_encap_match

2015-08-20T00:37:51+00:00

When CONFIG_LWTUNNEL config is not enabled, the lwtstate_free() is not
declared in lwtunnel.h at all. However, even in this case, the function
is still referenced in fib_semantics.c so that there appears the
following sparse warnings:

net/ipv4/fib_semantics.c:553:17: error: undefined identifier 'lwtstate_free'
  CC      net/ipv4/fib_semantics.o
  net/ipv4/fib_semantics.c: In function ‘fib_encap_match’:
  net/ipv4/fib_semantics.c:553:3: error: implicit declaration of function ‘lwtstate_free’ [-Werror=implicit-function-declaration]
  cc1: some warnings being treated as errors
  make[1]: *** [net/ipv4/fib_semantics.o] Error 1
  make: *** [net/ipv4/fib_semantics.o] Error 2

To eliminate the error, we define an empty function for lwtstate_free()
in lwtunnel.h when CONFIG_LWTUNNEL is disabled.

Fixes: df383e6240ef ("lwtunnel: fix memory leak")
Cc: Jiri Benc 
Reported-by: kbuild test robot 
Signed-off-by: Ying Xue 
Acked-by: Jiri Benc 
Signed-off-by: David S. Miller