Commit Graph

158 Commits

Author SHA1 Message Date
David Ahern b7b386f42f net: mpls: Pull common label check into helper
mpls_route_add and mpls_route_del have the same checks on the label.
Move to a helper. Avoid duplicate extack messages in the next patch.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:32 -04:00
David Ahern a1f10abe12 net: Fill in extack for mpls lwt encap
Fill in extack for errors in build_state for mpls lwt encap including
passing extack to nla_get_labels and adding error messages for failures
in it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:32 -04:00
David Ahern 9ae2872748 net: add extack arg to lwtunnel build state
Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:32 -04:00
Michal Hocko 752ade68cb treewide: use kv[mz]alloc* rather than opencoded variants
There are many code paths opencoding kvmalloc.  Let's use the helper
instead.  The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator.  E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation.  This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously.  There is no guarantee something like that happens
though.

This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.

Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:13 -07:00
David Ahern c21ef3e343 net: rtnetlink: plumb extended ack to doit function
Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
for doit functions that call it directly.

This is the first step to using extended error reporting in rtnetlink.
>From here individual subsystems can be updated to set netlink_ext_ack as
needed.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17 15:35:38 -04:00
Johannes Berg fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
David Ahern 1511009cd6 net: mpls: Increase max number of labels for lwt encap
Alow users to push down more labels per MPLS encap. Similar to LSR case,
move label array to the end of mpls_iptunnel_encap and allocate based on
the number of labels for the route.

For consistency with the LSR case, re-use the same maximum number of
labels.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern a4ac8c986d net: mpls: bump maximum number of labels
Allow users to push down more labels per MPLS route. With the previous
patches, no memory allocations are based on MAX_NEW_LABELS; the limit
is only used to keep userspace in check.

At this point MAX_NEW_LABELS is only used for mpls_route_config (copying
route data from userspace) and processing nexthops looking for the max
number of labels across the route spec.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern df1c631648 net: mpls: Limit memory allocation for mpls_route
Limit memory allocation size for mpls_route to 4096.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern 59b209667a net: mpls: change mpls_route layout
Move labels to the end of mpls_nh as a 0-sized array and within mpls_route
move the via for a nexthop after the mpls_nh. The new layout becomes:

   +----------------------+
   | mpls_route           |
   +----------------------+
   | mpls_nh 0            |
   +----------------------+
   | alignment padding    |   4 bytes for odd number of labels; 0 for even
   +----------------------+
   | via[rt_max_alen] 0   |
   +----------------------+
   | alignment padding    |   via's aligned on sizeof(unsigned long)
   +----------------------+
   | ...                  |
   +----------------------+
   | mpls_nh n-1          |
   +----------------------+
   | via[rt_max_alen] n-1 |
   +----------------------+

Memory allocated for nexthop + via is constant across all nexthops and
their via. It is based on the maximum number of labels across all nexthops
and the maximum via length. The size is saved in the mpls_route as
rt_nh_size. Accessing a nexthop becomes rt->rt_nh + index * rt->rt_nh_size.

The offset of the via address from a nexthop is saved as rt_via_offset
so that given an mpls_nh pointer the via for that hop is simply
nh + rt->rt_via_offset.

With prior code, memory allocated per mpls_route with 1 nexthop:
     via is an ethernet address - 64 bytes
     via is an ipv4 address     - 64
     via is an ipv6 address     - 72

With this patch set, memory allocated per mpls_route with 1 nexthop and
1 or 2 labels:
     via is an ethernet address - 56 bytes
     via is an ipv4 address     - 56
     via is an ipv6 address     - 64

The 8-byte reduction is due to the previous patch; the change introduced
by this patch has no impact on the size of allocations for 1 or 2 labels.

Performance impact of this change was examined using network namespaces
with veth pairs connecting namespaces. ns0 inserts the packet to the
label-switched path using an lwt route with encap mpls. ns1 adds 1 or 2
labels depending on test, ns2 (and ns3 for 2-label test) pops the label
and forwards. ns3 (or ns4) for a 2-label is the destination. Similar
series of namespaces used for 2-nexthop test.

Intent is to measure changes to latency (overhead in manipulating the
packet) in the forwarding path. Tests used netperf with UDP_RR.

IPv4:                     current   patches
   1 label, 1 nexthop      29908     30115
   2 label, 1 nexthop      29071     29612
   1 label, 2 nexthop      29582     29776
   2 label, 2 nexthop      29086     29149

IPv6:                     current   patches
   1 label, 1 nexthop      24502     24960
   2 label, 1 nexthop      24041     24407
   1 label, 2 nexthop      23795     23899
   2 label, 2 nexthop      23074     22959

In short, the change has no effect to a modest increase in performance.
This is expected since this patch does not really have an impact on routes
with 1 or 2 labels (the current limit) and 1 or 2 nexthops.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern 77ef013aad net: mpls: Convert number of nexthops to u8
Number of nexthops and number of alive nexthops are tracked using an
unsigned int. A route should never have more than 255 nexthops so
convert both to u8. Update all references and intermediate variables
to consistently use u8 as well.

Shrinks the size of mpls_route from 32 bytes to 24 bytes with a 2-byte
hole before the nexthops.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern 39eb8cd175 net: mpls: rt_nhn_alive and nh_flags should be accessed using READ_ONCE
The number of alive nexthops for a route (rt->rt_nhn_alive) and the
flags for a next hop (nh->nh_flags) are modified by netdev event
handlers. The event handlers run with rtnl_lock held so updates are
always done with the lock held. The packet path accesses the fields
under the rcu lock. Since those fields can change at any moment in
the packet path, both fields should be accessed using READ_ONCE. Updates
to both fields should use WRITE_ONCE.

Update mpls_select_multipath (packet path) and mpls_ifdown and mpls_ifup
(event handlers) accordingly.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-01 20:21:44 -07:00
David Ahern e944e97afc net: mpls: Update lfib_nlmsg_size to skip deleted nexthops
A recent commit skips nexthops in a route if the device has been
deleted. Update lfib_nlmsg_size accordingly.

Reported-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-29 10:42:38 -07:00
David Ahern 1182e4d0b4 net: mpls: Send netconf messages on device register and unregister
Send netconf notifications for MPLS when the device registers and
unregisters.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-28 22:32:43 -07:00
David Ahern 823566aee0 net:mpls: Refactor mpls_netconf_notify_devconf to take event
Refactor mpls_netconf_notify_devconf to take the event as an input arg.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-28 22:32:43 -07:00
David Ahern 4ea8efadf5 net: mpls: Delete route when all nexthops have been deleted
When all devices for all nexthops in a route have been deleted, the
route is effectively dead, so remove it.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-27 14:09:50 -07:00
David Ahern c00e51ddbf net: mpls: Don't show nexthop if device has been deleted
If the device for a nexthop in a multipath route is deleted, the nexthop
is effectively removed from the route. Currently, a route dump still
returns the nexhop though without the device set:

$ ip -f mpls ro ls
100
	nexthopvia inet 10.11.1.2  dev br0
	nexthopvia inet 10.100.3.1  dev eth3
$ ip li del br0
$ ip -f mpls ro ls
100
	nexthopvia inet 10.11.1.2  dev * dead linkdown
	nexthopvia inet 10.100.3.1  dev eth3

Since the nexthop is effectively deleted, drop the hop from the route
dump.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-27 14:09:50 -07:00
David Ahern 6a18c31232 net: mpls: Fix setting ttl_propagate for rt2
Fix copy and paste error setting rt_ttl_propagate.

Fixes: 5b441ac878 ("mpls: allow TTL propagation to IP packets to be configured")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 13:29:17 -07:00
David S. Miller 16ae1f2236 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/broadcom/genet/bcmmii.c
	drivers/net/hyperv/netvsc.c
	kernel/bpf/hashtab.c

Almost entirely overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-23 16:41:27 -07:00
David Ahern 61733c91c4 net: mpls: Fix nexthop alive tracking on down events
Alive tracking of nexthops can account for a link twice if the carrier
goes down followed by an admin down of the same link rendering multipath
routes useless. This is similar to 79099aab38 for UNREGISTER events and
DOWN events.

Fix by tracking number of alive nexthops in mpls_ifdown similar to the
logic in mpls_ifup. Checking the flags per nexthop once after all events
have been processed is simpler than trying to maintian a running count
through all event combinations.

Also, WRITE_ONCE is used instead of ACCESS_ONCE to set rt_nhn_alive
per a comment from checkpatch:
    WARNING: Prefer WRITE_ONCE(<FOO>, <BAR>) over ACCESS_ONCE(<FOO>) = <BAR>

Fixes: c89359a42e ("mpls: support for dead routes")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 20:22:18 -07:00
David S. Miller 101c431492 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/broadcom/genet/bcmgenet.c
	net/core/sock.c

Conflicts were overlapping changes in bcmgenet and the
lockdep handling of sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-15 11:59:10 -07:00
Robert Shearman a59166e470 mpls: allow TTL propagation from IP packets to be configured
Allow TTL propagation from IP packets to MPLS packets to be
configured. Add a new optional LWT attribute, MPLS_IPTUNNEL_TTL, which
allows the TTL to be set in the resulting MPLS packet, with the value
of 0 having the semantics of enabling propagation of the TTL from the
IP header (i.e. non-zero values disable propagation).

Also allow the configuration to be overridden globally by reusing the
same sysctl to control whether the TTL is propagated from IP packets
into the MPLS header. If the per-LWT attribute is set then it
overrides the global configuration. If the TTL isn't propagated then a
default TTL value is used which can be configured via a new sysctl,
"net.mpls.default_ttl". This is kept separate from the configuration
of whether IP TTL propagation is enabled as it can be used in the
future when non-IP payloads are supported (i.e. where there is no
payload TTL that can be propagated).

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-13 15:29:22 -07:00
Robert Shearman 5b441ac878 mpls: allow TTL propagation to IP packets to be configured
Provide the ability to control on a per-route basis whether the TTL
value from an MPLS packet is propagated to an IPv4/IPv6 packet when
the last label is popped as per the theoretical model in RFC 3443
through a new route attribute, RTA_TTL_PROPAGATE which can be 0 to
mean disable propagation and 1 to mean enable propagation.

In order to provide the ability to change the behaviour for packets
arriving with IPv4/IPv6 Explicit Null labels and to provide an easy
way for a user to change the behaviour for all existing routes without
having to reprogram them, a global knob is provided. This is done
through the addition of a new per-namespace sysctl,
"net.mpls.ip_ttl_propagate", which defaults to enabled. If the
per-route attribute is set (either enabled or disabled) then it
overrides the global configuration.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-13 15:29:22 -07:00
David Ahern 79099aab38 mpls: Do not decrement alive counter for unregister events
Multipath routes can be rendered usesless when a device in one of the
paths is deleted. For example:

$ ip -f mpls ro ls
100
	nexthop as to 200 via inet 172.16.2.2  dev virt12
	nexthop as to 300 via inet 172.16.3.2  dev br0
101
	nexthop as to 201 via inet6 2000:2::2  dev virt12
	nexthop as to 301 via inet6 2000:3::2  dev br0

$ ip li del br0

When br0 is deleted the other hop is not considered in
mpls_select_multipath because of the alive check -- rt_nhn_alive
is 0.

rt_nhn_alive is decremented once in mpls_ifdown when the device is taken
down (NETDEV_DOWN) and again when it is deleted (NETDEV_UNREGISTER). For
a 2 hop route, deleting one device drops the alive count to 0. Since
devices are taken down before unregistering, the decrement on
NETDEV_UNREGISTER is redundant.

Fixes: c89359a42e ("mpls: support for dead routes")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-12 23:45:36 -07:00
David Ahern e37791ec1a mpls: Send route delete notifications when router module is unloaded
When the mpls_router module is unloaded, mpls routes are deleted but
notifications are not sent to userspace leaving userspace caches
out of sync. Add the call to mpls_notify_route in mpls_net_exit as
routes are freed.

Fixes: 0189197f44 ("mpls: Basic routing support")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-12 23:39:32 -07:00
David Ahern 24045a03b8 net: mpls: Add support for netconf
Add netconf support to MPLS. Allows userpsace to learn and be notified
of changes to 'input' enable setting per interface.

Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-20 11:13:37 -05:00
David Ahern 30357d7d8a lwtunnel: remove device arg to lwtunnel_build_state
Nothing about lwt state requires a device reference, so remove the
input argument.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-30 15:14:22 -05:00
David S. Miller 4e8f2fc1a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Two trivial overlapping changes conflicts in MPLS and mlx5.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-28 10:33:06 -05:00
Robert Shearman 88ff7334f2 net: Specify the owning module for lwtunnel ops
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 <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:21:36 -05:00
David Ahern 9f427a0e47 net: mpls: Fix multipath selection for LSR use case
MPLS multipath for LSR is broken -- always selecting the first nexthop
in the one label case. For example:

    $ ip -f mpls ro ls
    100
            nexthop as to 200 via inet 172.16.2.2  dev virt12
            nexthop as to 300 via inet 172.16.3.2  dev virt13
    101
            nexthop as to 201 via inet6 2000:2::2  dev virt12
            nexthop as to 301 via inet6 2000:3::2  dev virt13

In this example incoming packets have a single MPLS labels which means
BOS bit is set. The BOS bit is passed from mpls_forward down to
mpls_multipath_hash which never processes the hash loop because BOS is 1.

Update mpls_multipath_hash to process the entire label stack. mpls_hdr_len
tracks the total mpls header length on each pass (on pass N mpls_hdr_len
is N * sizeof(mpls_shim_hdr)). When the label is found with the BOS set
it verifies the skb has sufficient header for ipv4 or ipv6, and find the
IPv4 and IPv6 header by using the last mpls_hdr pointer and adding 1 to
advance past it.

With these changes I have verified the code correctly sees the label,
BOS, IPv4 and IPv6 addresses in the network header and icmp/tcp/udp
traffic for ipv4 and ipv6 are distributed across the nexthops.

Fixes: 1c78efa831 ("mpls: flow-based multipath selection")
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-23 12:48:14 -05:00
Robert Shearman 27d691056b mpls: Packet stats
Having MPLS packet stats is useful for observing network operation and
for diagnosing network problems. In the absence of anything better,
RFC2863 and RFC3813 are used for guidance for which stats to expose
and the semantics of them. In particular rx_noroutes maps to in
unknown protos in RFC2863. The stats are exposed to userspace via
AF_MPLS attributes embedded in the IFLA_STATS_AF_SPEC attribute of
RTM_GETSTATS messages.

All the introduced fields are 64-bit, even error ones, to ensure no
overflow with long uptimes. Per-CPU counters are used to avoid
cache-line contention on the commonly used fields. The other fields
have also been made per-CPU for code to avoid performance problems in
error conditions on the assumption that on some platforms the cost of
atomic operations could be more expensive than sending the packet
(which is what would be done in the success case). If that's not the
case, we could instead not use per-CPU counters for these fields.

Only unicast and non-fragment are exposed at the moment, but other
counters can be exposed in the future either by adding to the end of
struct mpls_link_stats or by additional netlink attributes in the
AF_MPLS IFLA_STATS_AF_SPEC nested attribute.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-17 14:38:43 -05:00
David S. Miller c63d352f05 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
Suraj Deshmukh 14dd3e1b97 net: af_mpls.c add space before open parenthesis
Adding space after switch keyword before open
parenthesis for readability purpose.

This patch fixes the checkpatch.pl warning:
space required before the open parenthesis '('

Signed-off-by: Suraj Deshmukh <surajssd009005@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05 13:25:55 -05:00
Thomas Graf f76a9db351 lwt: Remove unused len field
The field is initialized by ILA and MPLS but never used. Remove it.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-23 17:45:01 -04:00
Jiri Benc 9095e10edd mpls: move mpls_hdr to a common location
This will be also used by openvswitch.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-03 02:00:21 -04:00
stephen hemminger ce927bf174 mpls: get rid of trivial returns
return at end of function is useless.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01 10:13:15 -07:00
David Ahern 48d2ab609b net: mpls: Fixups for GSO
As reported by Lennert the MPLS GSO code is failing to properly segment
large packets. There are a couple of problems:

1. the inner protocol is not set so the gso segment functions for inner
   protocol layers are not getting run, and

2  MPLS labels for packets that use the "native" (non-OVS) MPLS code
   are not properly accounted for in mpls_gso_segment.

The MPLS GSO code was added for OVS. It is re-using skb_mac_gso_segment
to call the gso segment functions for the higher layer protocols. That
means skb_mac_gso_segment is called twice -- once with the network
protocol set to MPLS and again with the network protocol set to the
inner protocol.

This patch sets the inner skb protocol addressing item 1 above and sets
the network_header and inner_network_header to mark where the MPLS labels
start and end. The MPLS code in OVS is also updated to set the two
network markers.

>From there the MPLS GSO code uses the difference between the network
header and the inner network header to know the size of the MPLS header
that was pushed. It then pulls the MPLS header, resets the mac_len and
protocol for the inner protocol and then calls skb_mac_gso_segment
to segment the skb.

Afterward the inner protocol segmentation is done the skb protocol
is set to mpls for each segment and the network and mac headers
restored.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30 22:27:18 -07:00
Roopa Prabhu 14972cbd34 net: lwtunnel: Handle fragmentation
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 <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30 22:27:18 -07:00
Simon Horman 407f31be9d mpls: allow routes on ipip and sit devices
Allow MPLS routes on IPIP and SIT devices now that they
support forwarding MPLS packets.

Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-09 17:45:56 -04:00
Simon Horman 0d227a8672 mpls: allow routes on ipgre devices
This appears to be necessary and sufficient to provide
MPLS in GRE (RFC4023) support.

This can be used by establishing an ipgre tunnel device
and then routing MPLS over it.

The following example will forward MPLS frames received with an outermost
MPLS label 100 over tun1, a GRE tunnel. The forwarded packet will have the
outermost MPLS LSE removed and two new LSEs added with labels 200
(outermost) and 300 (next).

ip link add name tun1 type gre remote 10.0.99.193 local 10.0.99.192 ttl 225
ip link set up dev tun1
ip addr add 10.0.98.192/24 dev tun1
ip route sh

echo 1 > /proc/sys/net/mpls/conf/eth0/input
echo 101 > /proc/sys/net/mpls/platform_labels
ip -f mpls route add 100 as 200/300 via inet 10.0.98.193
ip -f mpls route sh

Also remove unnecessary braces.

Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-16 17:12:07 -07:00
Marcelo Ricardo Leitner ae7ef81ef0 skbuff: introduce skb_gso_validate_mtu
skb_gso_network_seglen is not enough for checking fragment sizes if
skb is using GSO_BY_FRAGS as we have to check frag per frag.

This patch introduces skb_gso_validate_mtu, based on the former, which
will wrap the use case inside it as all calls to skb_gso_network_seglen
were to validate if it fits on a given TMU, and improve the check.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03 19:37:21 -04:00
Tom Herbert 5c7cdf339a gso: Remove arbitrary checks for unsupported GSO
In several gso_segment functions there are checks of gso_type against
a seemingly arbitrary list of SKB_GSO_* flags. This seems like an
attempt to identify unsupported GSO types, but since the stack is
the one that set these GSO types in the first place this seems
unnecessary to do. If a combination isn't valid in the first
place that stack should not allow setting it.

This is a code simplication especially for add new GSO types.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 18:03:15 -04:00
Alexander Duyck cbc53e08a7 GSO: Add GSO type for fixed IPv4 ID
This patch adds support for TSO using IPv4 headers with a fixed IP ID
field.  This is meant to allow us to do a lossless GRO in the case of TCP
flows that use a fixed IP ID such as those that convert IPv6 header to IPv4
headers.

In addition I am adding a feature that for now I am referring to TSO with
IP ID mangling.  Basically when this flag is enabled the device has the
option to either output the flow with incrementing IP IDs or with a fixed
IP ID regardless of what the original IP ID ordering was.  This is useful
in cases where the DF bit is set and we do not care if the original IP ID
value is maintained.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14 16:23:40 -04:00
Roopa Prabhu 94a57f1f8a mpls: find_outdev: check for err ptr in addition to NULL check
find_outdev calls inet{,6}_fib_lookup_dev() or dev_get_by_index() to
find the output device. In case of an error, inet{,6}_fib_lookup_dev()
returns error pointer and dev_get_by_index() returns NULL. But the function
only checks for NULL and thus can end up calling dev_put on an ERR_PTR.
This patch adds an additional check for err ptr after the NULL check.

Before: Trying to add an mpls route with no oif from user, no available
path to 10.1.1.8 and no default route:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
[  822.337195] BUG: unable to handle kernel NULL pointer dereference at
00000000000003a3
[  822.340033] IP: [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[  822.340033] PGD 1db38067 PUD 1de9e067 PMD 0
[  822.340033] Oops: 0000 [#1] SMP
[  822.340033] Modules linked in:
[  822.340033] CPU: 0 PID: 11148 Comm: ip Not tainted 4.5.0-rc7+ #54
[  822.340033] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org
04/01/2014
[  822.340033] task: ffff88001db82580 ti: ffff88001dad4000 task.ti:
ffff88001dad4000
[  822.340033] RIP: 0010:[<ffffffff8148781e>]  [<ffffffff8148781e>]
mpls_nh_assign_dev+0x10b/0x182
[  822.340033] RSP: 0018:ffff88001dad7a88  EFLAGS: 00010282
[  822.340033] RAX: ffffffffffffff9b RBX: ffffffffffffff9b RCX:
0000000000000002
[  822.340033] RDX: 00000000ffffff9b RSI: 0000000000000008 RDI:
0000000000000000
[  822.340033] RBP: ffff88001ddc9ea0 R08: ffff88001e9f1768 R09:
0000000000000000
[  822.340033] R10: ffff88001d9c1100 R11: ffff88001e3c89f0 R12:
ffffffff8187e0c0
[  822.340033] R13: ffffffff8187e0c0 R14: ffff88001ddc9e80 R15:
0000000000000004
[  822.340033] FS:  00007ff9ed798700(0000) GS:ffff88001fc00000(0000)
knlGS:0000000000000000
[  822.340033] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  822.340033] CR2: 00000000000003a3 CR3: 000000001de89000 CR4:
00000000000006f0
[  822.340033] Stack:
[  822.340033]  0000000000000000 0000000100000000 0000000000000000
0000000000000000
[  822.340033]  0000000000000000 0801010a00000000 0000000000000000
0000000000000000
[  822.340033]  0000000000000004 ffffffff8148749b ffffffff8187e0c0
000000000000001c
[  822.340033] Call Trace:
[  822.340033]  [<ffffffff8148749b>] ? mpls_rt_alloc+0x2b/0x3e
[  822.340033]  [<ffffffff81488e66>] ? mpls_rtm_newroute+0x358/0x3e2
[  822.340033]  [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[  822.340033]  [<ffffffff813b7d94>] ? rtnetlink_rcv_msg+0x17e/0x191
[  822.340033]  [<ffffffff8111794e>] ? __kmalloc_track_caller+0x8c/0x9e
[  822.340033]  [<ffffffff813c9393>] ?
rht_key_hashfn.isra.20.constprop.57+0x14/0x1f
[  822.340033]  [<ffffffff813b7c16>] ? __rtnl_unlock+0xc/0xc
[  822.340033]  [<ffffffff813cb794>] ? netlink_rcv_skb+0x36/0x82
[  822.340033]  [<ffffffff813b4507>] ? rtnetlink_rcv+0x1f/0x28
[  822.340033]  [<ffffffff813cb2b1>] ? netlink_unicast+0x106/0x189
[  822.340033]  [<ffffffff813cb5b3>] ? netlink_sendmsg+0x27f/0x2c8
[  822.340033]  [<ffffffff81392ede>] ? sock_sendmsg_nosec+0x10/0x1b
[  822.340033]  [<ffffffff81393df1>] ? ___sys_sendmsg+0x182/0x1e3
[  822.340033]  [<ffffffff810e4f35>] ?
__alloc_pages_nodemask+0x11c/0x1e4
[  822.340033]  [<ffffffff8110619c>] ? PageAnon+0x5/0xd
[  822.340033]  [<ffffffff811062fe>] ? __page_set_anon_rmap+0x45/0x52
[  822.340033]  [<ffffffff810e7bbc>] ? get_page+0x5/0xa
[  822.340033]  [<ffffffff810e85ab>] ? __lru_cache_add+0x1a/0x3a
[  822.340033]  [<ffffffff81087ea9>] ? current_kernel_time64+0x9/0x30
[  822.340033]  [<ffffffff813940c4>] ? __sys_sendmsg+0x3c/0x5a
[  822.340033]  [<ffffffff8148f597>] ?
entry_SYSCALL_64_fastpath+0x12/0x6a
[  822.340033] Code: 83 08 04 00 00 65 ff 00 48 8b 3c 24 e8 40 7c f2 ff
eb 13 48 c7 c3 9f ff ff ff eb 0f 89 ce e8 f1 ae f1 ff 48 89 c3 48 85 db
74 15 <48> 8b 83 08 04 00 00 65 ff 08 48 81 fb 00 f0 ff ff 76 0d eb 07
[  822.340033] RIP  [<ffffffff8148781e>] mpls_nh_assign_dev+0x10b/0x182
[  822.340033]  RSP <ffff88001dad7a88>
[  822.340033] CR2: 00000000000003a3
[  822.435363] ---[ end trace 98cc65e6f6b8bf11 ]---

After patch:
$ip -f mpls route add 100 as 200 via inet 10.1.1.8
RTNETLINK answers: Network is unreachable

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-08 12:43:20 -04:00
Robert Shearman b2b04edceb mpls: autoload lwt module
Avoid users having to manually load the module by adding a module
alias allowing it to be autoloaded by the lwt infra.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-21 22:00:28 -05:00
David S. Miller b3e0d3d7ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/geneve.c

Here we had an overlapping change, where in 'net' the extraneous stats
bump was being removed whilst in 'net-next' the final argument to
udp_tunnel6_xmit_skb() was being changed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 22:08:28 -05:00
Robert Shearman f20367df1a mpls: make via address optional for multipath routes
The via address is optional for a single path route, yet is mandatory
when the multipath attribute is used:

  # ip -f mpls route add 100 dev lo
  # ip -f mpls route add 101 nexthop dev lo
  RTNETLINK answers: Invalid argument

Make them consistent by making the via address optional when the
RTA_MULTIPATH attribute is being parsed so that both forms of
specifying the route work.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-12 00:43:44 -05:00
Robert Shearman eb7809f093 mpls: fix out-of-bounds access when via address not specified
When a via address isn't specified, the via table is left initialised
to 0 (NEIGH_ARP_TABLE), and the via address length also left
initialised to 0. This results in a via address array of length 0
being allocated (contiguous with route and nexthop array), meaning
that when a packet is sent using neigh_xmit the neighbour lookup and
creation will cause an out-of-bounds access when accessing the 4 bytes
of the IPv4 address it assumes it has been given a pointer to.

This could be fixed by allocating the 4 bytes of via address necessary
and leaving it as all zeroes. However, it seems wrong to me to use an
ipv4 nexthop (including possibly ARPing for 0.0.0.0) when the user
didn't specify to do so.

Instead, set the via address table to NEIGH_NR_TABLES to signify it
hasn't been specified and use this at forwarding time to signify a
neigh_xmit using an L2 address consisting of the device address. This
mechanism is the same as that used for both ARP and ND for loopback
interfaces and those flagged as no-arp, which are all we can really
support in this case.

Fixes: cf4b24f002 ("mpls: reduce memory usage of routes")
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-12 00:43:44 -05:00
Robert Shearman 72dcac96c7 mpls: don't dump RTA_VIA attribute if not specified
The problem seen is that when adding a route with a nexthop with no
via address specified, iproute2 generates bogus output:

  # ip -f mpls route add 100 dev lo
  # ip -f mpls route list
  100 via inet 0.0.8.0 dev lo

The reason for this is that the kernel generates an RTA_VIA attribute
with the family set to AF_INET, but the via address data having zero
length. The cause of family being AF_INET is that on route insert
cfg->rc_via_table is left set to 0, which just happens to be
NEIGH_ARP_TABLE which is then translated into AF_INET.

iproute2 doesn't validate the length prior to printing and so prints
garbage. Although it could be fixed to do the validation, I would
argue that AF_INET addresses should always be exactly 4 bytes so the
kernel is really giving userspace bogus data.

Therefore, avoid generating the RTA_VIA attribute when dumping the
route if the via address wasn't specified on add/modify. This is
indicated by NEIGH_ARP_TABLE and a zero via address length - if the
user specified a via address the address length would have been
validated such that it was 4 bytes. Although this is a change in
behaviour that is visible to userspace, I believe that what was
generated before was invalid and as such userspace wouldn't be
expecting it.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-12 00:43:44 -05:00
Robert Shearman a3e948e83a mpls: validate L2 via address length
If an L2 via address for an mpls nexthop is specified, the length of
the L2 address must match that expected by the output device,
otherwise it could access memory beyond the end of the via address
buffer in the route.

This check was present prior to commit f8efb73c97 ("mpls: multipath
route support"), but got lost in the refactoring, so add it back,
applying it to all nexthops in multipath routes.

Fixes: f8efb73c97 ("mpls: multipath route support")
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-12 00:43:44 -05:00
Roopa Prabhu 6e71b29908 mpls_iptunnel: add static qualifier to mpls_output
This gets rid of the following compile warn:
net/mpls/mpls_iptunnel.c:40:5: warning: no previous prototype for
mpls_output [-Wmissing-prototypes]

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-11 20:17:43 -05:00
Robert Shearman fe82b3300e mpls: fix sending of local encapped packets
Locally generated IPv4 and (probably) IPv6 packets are dropped because
skb->protocol isn't set. We could write wrappers to lwtunnel_output
for IPv4 and IPv6 that set the protocol accordingly and then call
lwtunnel_output, but mpls_output relies on the AF-specific type of dst
anyway to get the via address.

Therefore, make use of dst->dst_ops->family in mpls_output to
determine the type of nexthop and thus protocol of the packet instead
of checking skb->protocol.

Fixes: 61adedf3e3 ("route: move lwtunnel state to dst_entry")
Reported-by: Sam Russell <sam.h.russell@gmail.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-07 16:32:47 -05:00
Roopa Prabhu c89359a42e mpls: support for dead routes
Adds support for RTNH_F_DEAD and RTNH_F_LINKDOWN flags on mpls
routes due to link events. Also adds code to ignore dead
routes during route selection.

Unlike ip routes, mpls routes are not deleted when the route goes
dead. This is current mpls behaviour and this patch does not change
that. With this patch however, routes will be marked dead.
dead routes are not notified to userspace (this is consistent with ipv4
routes).

dead routes:
-----------
$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1
    nexthop as to 700 via inet 10.1.1.6  dev swp2

$ip link set dev swp1 down

$ip link show dev swp1
4: swp1: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode
DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1 dead linkdown
    nexthop as to 700 via inet 10.1.1.6  dev swp2

linkdown routes:
----------------
$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1
    nexthop as to 700 via inet 10.1.1.6  dev swp2

$ip link show dev swp1
4: swp1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
state UP mode DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

/* carrier goes down */
$ip link show dev swp1
4: swp1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast
state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1 linkdown
    nexthop as to 700 via inet 10.1.1.6  dev swp2

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 15:03:27 -05:00
Robert Shearman cf4b24f002 mpls: reduce memory usage of routes
Nexthops for MPLS routes have a via address field sized for the
largest via address that is expected, which is 32 bytes. This means
that in the most common case of having ipv4 via addresses, 28 bytes of
memory more than required are used per nexthop. In the other common
case of an ipv6 nexthop then 16 bytes more than required are
used. With large numbers of MPLS routes this extra memory usage could
start to become significant.

To avoid allocating memory for a maximum length via address when not
all of it is required and to allow for ease of iterating over
nexthops, then the via addresses are changed to be stored in the same
memory block as the route and nexthops, but in an array after the end
of the array of nexthops. New accessors are provided to retrieve a
pointer to the via address.

To allow for O(1) access without having to store a pointer or offset
per nh, the via address for each nexthop is sized according to the
maximum via address for any nexthop in the route, which is stored in a
new route field, rt_max_alen, but this is in an existing hole in
struct mpls_route so it doesn't increase the size of the
structure. Each via address is ensured to be aligned to VIA_ALEN_ALIGN
to account for architectures that don't allow unaligned accesses.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-27 19:52:59 -07:00
Robert Shearman b4e04fc735 mpls: fix forwarding using v4/v6 explicit null
Fill in the via address length for the predefined IPv4 and IPv6
explicit-null label routes.

Fixes: f8efb73c97 ("mpls: multipath route support")
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-27 19:52:58 -07:00
Robert Shearman 1c78efa831 mpls: flow-based multipath selection
Change the selection of a multipath route to use a flow-based
hash. This more suitable for traffic sensitive to reordering within a
flow (e.g. TCP, L2VPN) and whilst still allowing a good distribution
of traffic given enough flows.

Selection of the path for a multipath route is done using a hash of:
1. Label stack up to MAX_MP_SELECT_LABELS labels or up to and
   including entropy label, whichever is first.
2. 3-tuple of (L3 src, L3 dst, proto) from IPv4/IPv6 header in MPLS
   payload, if present.

Naturally, a 5-tuple hash using L4 information in addition would be
possible and be better in some scenarios, but there is a tradeoff
between looking deeper into the packet to achieve good distribution,
and packet forwarding performance, and I have erred on the side of the
latter as the default.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23 06:26:45 -07:00
Roopa Prabhu f8efb73c97 mpls: multipath route support
This patch adds support for MPLS multipath routes.

Includes following changes to support multipath:
- splits struct mpls_route into 'struct mpls_route + struct mpls_nh'

- 'struct mpls_nh' represents a mpls nexthop label forwarding entry

- moves mpls route and nexthop structures into internal.h

- A mpls_route can point to multiple mpls_nh structs

- the nexthops are maintained as a array (similar to ipv4 fib)

- In the process of restructuring, this patch also consistently changes
  all labels to u8

- Adds support to parse/fill RTA_MULTIPATH netlink attribute for
multipath routes similar to ipv4/v6 fib

- In this patch, the multipath route nexthop selection algorithm
simply returns the first nexthop. It is replaced by a
hash based algorithm from Robert Shearman in the next patch

- mpls_route_update cleanup: remove 'dev' handling in mpls_route_update.
mpls_route_update though implemented to update based on dev, it was
never used that way. And the dev handling gets tricky with multiple
nexthops. Cannot match against any single nexthops dev. So, this patch
removes the unused 'dev' handling in mpls_route_update.

- dead route/path handling will be implemented in a subsequent patch

Example:

$ip -f mpls route add 100 nexthop as 200 via inet 10.1.1.2 dev swp1 \
                nexthop as 700 via inet 10.1.1.6 dev swp2 \
                nexthop as 800 via inet 40.1.1.2 dev swp3

$ip  -f mpls route show
100
        nexthop as to 200 via inet 10.1.1.2  dev swp1
        nexthop as to 700 via inet 10.1.1.6  dev swp2
        nexthop as to 800 via inet 40.1.1.2  dev swp3

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23 06:26:42 -07:00
Eric W. Biederman ede2059dba dst: Pass net into dst->output
The network namespace is already passed into dst_output pass it into
dst->output lwt->output and friends.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 04:27:03 -07:00
Nikolay Aleksandrov 6ea3c9d5b0 mpls: fix mpls_net_init memory leak
Fix a memory leak in the mpls netns init function in case of failure. If
register_net_sysctl fails then we need to free the ctl_table.

Fixes: 7720c01f3f ("mpls: Add a sysctl to control the size of the mpls label table")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-31 12:45:09 -07:00
Tom Herbert 127eb7cd3c lwt: Add cfg argument to build_state
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 <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-24 10:34:40 -07:00
Jiri Benc 61adedf3e3 route: move lwtunnel state to dst_entry
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 <jbenc@redhat.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20 15:42:36 -07:00
Robert Shearman 118d523463 mpls: Enforce payload type of traffic sent using explicit NULL
RFC 4182 s2 states that if an IPv4 Explicit NULL label is the only
label on the stack, then after popping the resulting packet must be
treated as a IPv4 packet and forwarded based on the IPv4 header. The
same is true for IPv6 Explicit NULL with an IPv6 packet following.

Therefore, when installing the IPv4/IPv6 Explicit NULL label routes,
add an attribute that specifies the expected payload type for use at
forwarding time for determining the type of the encapsulated packet
instead of inspecting the first nibble of the packet.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-09 22:51:42 -07:00
Roopa Prabhu 3dcb615e68 af_mpls: add null dev check in find_outdev
This patch adds null dev check for the 'cfg->rc_via_table ==
NEIGH_LINK_TABLE or dev_get_by_index() failed' case

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 22:03:58 -07:00
Dan Carpenter 5a9348b54d mpls: small cleanup in inet/inet6_fib_lookup_dev()
We recently changed this code from returning NULL to returning ERR_PTR.
There are some left over NULL assignments which we can remove.  We can
preserve the error code from ip_route_output() instead of always
returning -ENODEV.  Also these functions use a mix of gotos and direct
returns.  There is no cleanup necessary so I changed the gotos to
direct returns.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 21:56:55 -07:00
Robert Shearman a6affd24f4 mpls: Use definition for reserved label checks
In multiple locations there are checks for whether the label in hand
is a reserved label or not using the arbritray value of 16. Factor
this out into a #define for better maintainability and for
documentation.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-03 22:35:00 -07:00
Roopa Prabhu bf21563acc af_mpls: fix undefined reference to ip6_route_output
Undefined reference to ip6_route_output and ip_route_output
was reported with CONFIG_INET=n and CONFIG_IPV6=n.

This patch uses ipv6_stub_impl.ipv6_dst_lookup instead of
ip6_route_output. And wraps affected code under
IS_ENABLED(CONFIG_INET) and IS_ENABLED(CONFIG_IPV6).

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 15:21:30 -07:00
Roopa Prabhu de18547d48 mpls_iptunnel: fix sparse warn: remove incorrect rcu_dereference
fix for:
net/mpls/mpls_iptunnel.c:73:19: sparse: incompatible types in comparison
expression (different address spaces)

remove incorrect rcu_dereference possibly left over from
earlier revisions of the code.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-22 10:50:23 -07:00
Roopa Prabhu 01faef2ceb mpls: make RTA_OIF optional
If user did not specify an oif, try and get it from the via address.
If failed to get device, return with -ENODEV.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21 22:27:19 -07:00
Roopa Prabhu e3e4712ec0 mpls: ip tunnel support
This implementation uses lwtunnel infrastructure to register
hooks for mpls tunnel encaps.

It picks cues from iptunnel_encaps infrastructure and previous
mpls iptunnel RFC patches from Eric W. Biederman and Robert Shearman

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21 10:39:05 -07:00
Roopa Prabhu face0188e3 mpls: export mpls functions for use by mpls iptunnels
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21 10:39:04 -07:00
David S. Miller 25c43bf13b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-13 23:56:52 -07:00
Robert Shearman 0fae3bf018 mpls: handle device renames for per-device sysctls
If a device is renamed and the original name is subsequently reused
for a new device, the following warning is generated:

sysctl duplicate entry: /net/mpls/conf/veth0//input
CPU: 3 PID: 1379 Comm: ip Not tainted 4.1.0-rc4+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
 0000000000000000 0000000000000000 ffffffff81566aaf 0000000000000000
 ffffffff81236279 ffff88002f7d7f00 0000000000000000 ffff88000db336d8
 ffff88000db33698 0000000000000005 ffff88002e046000 ffff8800168c9280
Call Trace:
 [<ffffffff81566aaf>] ? dump_stack+0x40/0x50
 [<ffffffff81236279>] ? __register_sysctl_table+0x289/0x5a0
 [<ffffffffa051a24f>] ? mpls_dev_notify+0x1ff/0x300 [mpls_router]
 [<ffffffff8108db7f>] ? notifier_call_chain+0x4f/0x70
 [<ffffffff81470e72>] ? register_netdevice+0x2b2/0x480
 [<ffffffffa0524748>] ? veth_newlink+0x178/0x2d3 [veth]
 [<ffffffff8147f84c>] ? rtnl_newlink+0x73c/0x8e0
 [<ffffffff8147f27a>] ? rtnl_newlink+0x16a/0x8e0
 [<ffffffff81459ff2>] ? __kmalloc_reserve.isra.30+0x32/0x90
 [<ffffffff8147ccfd>] ? rtnetlink_rcv_msg+0x8d/0x250
 [<ffffffff8145b027>] ? __alloc_skb+0x47/0x1f0
 [<ffffffff8149badb>] ? __netlink_lookup+0xab/0xe0
 [<ffffffff8147cc70>] ? rtnetlink_rcv+0x30/0x30
 [<ffffffff8149e7a0>] ? netlink_rcv_skb+0xb0/0xd0
 [<ffffffff8147cc64>] ? rtnetlink_rcv+0x24/0x30
 [<ffffffff8149df17>] ? netlink_unicast+0x107/0x1a0
 [<ffffffff8149e4be>] ? netlink_sendmsg+0x50e/0x630
 [<ffffffff8145209c>] ? sock_sendmsg+0x3c/0x50
 [<ffffffff81452beb>] ? ___sys_sendmsg+0x27b/0x290
 [<ffffffff811bd258>] ? mem_cgroup_try_charge+0x88/0x110
 [<ffffffff811bd5b6>] ? mem_cgroup_commit_charge+0x56/0xa0
 [<ffffffff811d7700>] ? do_filp_open+0x30/0xa0
 [<ffffffff8145336e>] ? __sys_sendmsg+0x3e/0x80
 [<ffffffff8156c3f2>] ? system_call_fastpath+0x16/0x75

Fix this by unregistering the previous sysctl table (registered for
the path containing the original device name) and re-registering the
table for the path containing the new device name.

Fixes: 37bde79979 ("mpls: Per-device enabling of packet input")
Reported-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-11 16:47:16 -07:00
David S. Miller 941742f497 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-08 20:06:56 -07:00
Robert Shearman 25cc8f0763 mpls: fix possible use after free of device
The mpls device is used in an RCU read context without a lock being
held. As the memory is freed without waiting for the RCU grace period
to elapse, the freed memory could still be in use.

Address this by using kfree_rcu to free the memory for the mpls device
after the RCU grace period has elapsed.

Fixes: 03c57747a7 ("mpls: Per-device MPLS state")
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-07 19:37:27 -07:00
David S. Miller bdef7de4b8 net: Add priority to packet_offload objects.
When we scan a packet for GRO processing, we want to see the most
common packet types in the front of the offload_base list.

So add a priority field so we can handle this properly.

IPv4/IPv6 get the highest priority with the implicit zero priority
field.

Next comes ethernet with a priority of 10, and then we have the MPLS
types with a priority of 15.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-01 14:56:09 -07:00
Tom Herbert 78f5b89919 mpls: Change reserved label names to be consistent with netbsd
Since these are now visible to userspace it is nice to be consistent
with BSD (sys/netmpls/mpls.h in netBSD).

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:29:50 -04:00
Tom Herbert c967a0873a mpls: Move reserved label definitions
Move to include/uapi/linux/mpls.h to be externally visibile.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-05 19:40:36 -04:00
Robert Shearman 5a9ab01761 mpls: Prevent use of implicit NULL label as outgoing label
The reserved implicit-NULL label isn't allowed to appear in the label
stack for packets, so make it an error for the control plane to
specify it as an outgoing label.

Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 14:24:54 -04:00
Robert Shearman 37bde79979 mpls: Per-device enabling of packet input
An MPLS network is a single trust domain where the edges must be in
control of what labels make their way into the core. The simplest way
of ensuring this is for the edge device to always impose the labels,
and not allow forward labeled traffic from untrusted neighbours. This
is achieved by allowing a per-device configuration of whether MPLS
traffic input from that interface should be processed or not.

To be secure by default, the default state is changed to MPLS being
disabled on all interfaces unless explicitly enabled and no global
option is provided to change the default. Whilst this differs from
other protocols (e.g. IPv6), network operators are used to explicitly
enabling MPLS forwarding on interfaces, and with the number of links
to the MPLS core typically fairly low this doesn't present too much of
a burden on operators.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 14:24:54 -04:00
Robert Shearman 03c57747a7 mpls: Per-device MPLS state
Add per-device MPLS state to supported interfaces. Use the presence of
this state in mpls_route_add to determine that this is a supported
interface.

Use the presence of mpls_dev to drop packets that arrived on an
unsupported interface - previously they were allowed through.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 14:24:54 -04:00
Eric W. Biederman 76fecd8275 mpls: In mpls_egress verify the packet length.
Reobert Shearman noticed that mpls_egress is failing to verify that
the bytes to be examined are in fact present in the packet before
mpls_egress reads those bytes.

As suggested by David Miller reduce this to a single pskb_may_pull
call so that we don't do unnecessary work in the fast path.

Reported-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 23:05:04 -04:00
Robert Shearman 8a08919f43 mpls: Allow mpls_gso and mpls_router to be built as modules
CONFIG_MPLS=m doesn't result in a kernel module being built because it
applies to the net/mpls directory, rather than to .o files.

So revert the MPLS menuitem to being a boolean and make MPLS_GSO and
MPLS_ROUTING tristates to allow mpls_gso and mpls_router modules to be
produced as desired.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 16:38:54 -04:00
Geert Uytterhoeven 26c459a807 mpls: Spelling: s/conceved/conceived/, s/as/a/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09 15:51:59 -04:00
Eric W. Biederman b79bda3d38 neigh: Use neigh table index for neigh_packet_xmit
Remove a little bit of unnecessary work when transmitting a packet with
neigh_packet_xmit.  Use the neighbour table index not the address family
as a parameter.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Eric W. Biederman aa7da93756 mpls: Correct the ttl decrement.
According to RFC3032 section 2.4.2  packets with an outgoing
ttl of 0 MUST NOT be forwarded.  According to section 2.4.1
an outgoing TTL of 0 comes from an incomming TTL <= 1.

Therefore any packets that is received with a ttl <= 1 should
not have it's ttl decremented and forwarded.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Eric W. Biederman 0f7bbd5805 mpls: Better error code for unsupported option.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Eric W. Biederman 19d0c341d9 mpls: Cleanup the rcu usage in the code.
Sparse was generating a lot of warnings mostly from missing annotations
in the code.  Add missing annotations and in a few cases tweak the code
for performance by moving work before loops.

This also fixes a problematic ommision of rcu_assign_pointer and
rcu_dereference.

Hopefully with complete rcu annotations any new rcu errors will stick
out like a sore thumb.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Eric W. Biederman d865616e18 mpls: Fix the kzalloc argument order in mpls_rt_alloc
*Blink* I got the argument order wrong to kzalloc and the
code was working properly when tested. *Blink*

Fix that.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08 19:30:06 -04:00
Robert Shearman f8d54afc4c mpls: Properly validate RTA_VIA payload length
If the nla length is less than 2 then the nla data could be accessed
beyond the accessible bounds. So ensure that the nla is big enough to
at least read the via_family before doing so. Replace magic value of
2.

Fixes: 03c0566542 ("mpls: Basic support for adding and removing routes")
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 15:19:06 -05:00
Stephen Rothwell 4b5edb2f4a mpls: using vzalloc requires including vmalloc.h
Fixes this build error:

net/mpls/af_mpls.c: In function 'resize_platform_label_table':
net/mpls/af_mpls.c:767:4: error: implicit declaration of function 'vzalloc' [-Werror=implicit-function-declaration]
    labels = vzalloc(size);
    ^

Fixes: 7720c01f3f ("mpls: Add a sysctl to control the size of the mpls label table")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-05 21:01:33 -05:00
Wu Fengguang f0126539c7 mpls: rtm_mpls_policy[] can be static
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 16:39:45 -05:00
Eric W. Biederman 8de147dc8e mpls: Multicast route table change notifications
Unlike IPv4 this code notifies on all cases where mpls routes
are added or removed and it never automatically removes routes.
Avoiding both the userspace confusion that is caused by omitting
route updates and the possibility of a flood of netlink traffic
when an interface goes doew.

For now reserved labels are handled automatically and userspace
is not notified.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman 03c0566542 mpls: Netlink commands to add, remove, and dump routes
This change adds two new netlink routing attributes:
RTA_VIA and RTA_NEWDST.

RTA_VIA specifies the specifies the next machine to send a packet to
like RTA_GATEWAY.  RTA_VIA differs from RTA_GATEWAY in that it
includes the address family of the address of the next machine to send
a packet to.  Currently the MPLS code supports addresses in AF_INET,
AF_INET6 and AF_PACKET.  For AF_INET and AF_INET6 the destination mac
address is acquired from the neighbour table.  For AF_PACKET the
destination mac_address is specified in the netlink configuration.

I think raw destination mac address support with the family AF_PACKET
will prove useful.  There is MPLS-TP which is defined to operate
on machines that do not support internet packets of any flavor.  Further
seem to be corner cases where it can be useful.  At this point
I don't care much either way.

RTA_NEWDST specifies the destination address to forward the packet
with.  MPLS typically changes it's destination address at every hop.
For a swap operation RTA_NEWDST is specified with a length of one label.
For a push operation RTA_NEWDST is specified with two or more labels.
For a pop operation RTA_NEWDST is not specified or equivalently an emtpy
RTAN_NEWDST is specified.

Those new netlink attributes are used to implement handling of rt-netlink
RTM_NEWROUTE, RTM_DELROUTE, and RTM_GETROUTE messages, to maintain the
MPLS label table.

rtm_to_route_config parses a netlink RTM_NEWROUTE or RTM_DELROUTE message,
verify no unhandled attributes or unhandled values are present and sets
up the data structures for mpls_route_add and mpls_route_del.

I did my best to match up with the existing conventions with the caveats
that MPLS addresses are all destination-specific-addresses, and so
don't properly have a scope.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman 966bae3349 mpls: Functions for reading and wrinting mpls labels over netlink
Reading and writing addresses in network byte order in netlink is
traditional and I see no reason to change that.  MPLS is interesting
as effectively it has variabely length addresses (the MPLS label
stack).  To represent these variable length addresses in netlink
I use a valid MPLS label stack (complete with stop bit).

This achieves two things: a well defined existing format is used,
and the data can be interpreted without looking at it's length.

Not needed to look at the length to decode the variable length
network representation allows existing userspace functions
such as inet_ntop to be used without needed to change their
prototype.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman a2519929ab mpls: Basic support for adding and removing routes
mpls_route_add and mpls_route_del implement the basic logic for adding
and removing Next Hop Label Forwarding Entries from the MPLS input
label map.  The addition and subtraction is done in a way that is
consistent with how the existing routing table in Linux are
maintained.  Thus all of the work to deal with NLM_F_APPEND,
NLM_F_EXCL, NLM_F_REPLACE, and NLM_F_CREATE.

Cases that are not clearly defined such as changing the interpretation
of the mpls reserved labels is not allowed.

Because it seems like the right thing to do adding an MPLS route without
specifying an input label and allowing the kernel to pick a free label
table entry is supported.   The implementation is currently less than optimal
but that can be changed.

As I don't have anything else to test with only ethernet and the loopback
device are the only two device types currently supported for forwarding
MPLS over.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman 7720c01f3f mpls: Add a sysctl to control the size of the mpls label table
This sysctl gives two benefits.  By defaulting the table size to 0
mpls even when compiled in and enabled defaults to not forwarding
any packets.  This prevents unpleasant surprises for users.

The other benefit is that as mpls labels are allocated locally a dense
table a small dense label table may be used which saves memory and
is extremely simple and efficient to implement.

This sysctl allows userspace to choose the restrictions on the label
table size userspace applications need to cope with.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman 0189197f44 mpls: Basic routing support
This change adds a new Kconfig option MPLS_ROUTING.

The core of this change is the code to look at an mpls packet received
from another machine.  Look that packet up in a routing table and
forward the packet on.

Support of MPLS over ATM is not considered or attempted here.  This
implemntation follows RFC3032 and implements the MPLS shim header that
can pass over essentially any network.

What RFC3021 refers to as the as the Incoming Label Map (ILM) I call
net->mpls.platform_label[].  What RFC3031 refers to as the Next Label
Hop Forwarding Entry (NHLFE) I call mpls_route.  Though calling it the
label fordwarding information base (lfib) might also be valid.

Further the implemntation forwards packets as described in RFC3032.
There is no need and given the original motivation for MPLS a strong
discincentive to have a flexible label forwarding path.  In essence
the logic is the topmost label is read, looked up, removed, and
replaced by 0 or more new lables and the sent out the specified
interface to it's next hop.

Quite a few optional features are not implemented here.  Among them
are generation of ICMP errors when the TTL is exceeded or the packet
is larger than the next hop MTU (those conditions are detected and the
packets are dropped instead of generating an icmp error).  The traffic
class field is always set to 0.  The implementation focuses on IP over
MPLS and does not handle egress of other kinds of protocols.

Instead of implementing coordination with the neighbour table and
sorting out how to input next hops in a different address family (for
which there is value).  I was lazy and implemented a next hop mac
address instead.  The code is simpler and there are flavor of MPLS
such as MPLS-TP where neither an IPv4 nor an IPv6 next hop is
appropriate so a next hop by mac address would need to be implemented
at some point.

Two new definitions AF_MPLS and PF_MPLS are exposed to userspace.

Decoding the mpls header must be done by first byeswapping a 32bit bit
endian word into the local cpu endian and then bit shifting to extract
the pieces.  There is no C bit-field that can represent a wire format
mpls header on a little endian machine as the low bits of the 20bit
label wind up in the wrong half of third byte.  Therefore internally
everything is deal with in cpu native byte order except when writing
to and reading from a packet.

For management simplicity if a label is configured to forward out
an interface that is down the packet is dropped early.  Similarly
if an network interface is removed rt_dev is updated to NULL
(so no reference is preserved) and any packets for that label
are dropped.  Keeping the label entries in the kernel allows
the kernel label table to function as the definitive source
of which labels are allocated and which are not.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman cec9166ca4 mpls: Refactor how the mpls module is built
This refactoring is needed to allow more than just mpls gso
support to be built into the mpls moddule.

Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Daniel Borkmann 207895fd38 net: mark some potential candidates __read_mostly
They are all either written once or extremly rarely (e.g. from init
code), so we can move them to the .data..read_mostly section.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-30 17:58:39 -08:00
Pravin B Shelar 4cc1beca30 mpls: Fix allowed protocols for mpls gso
MPLS and Tunnel GSO does not work together.  Reject packet which
request such GSO.

Fixes: 0d89d2035f ("MPLS: Add limited GSO support").
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-23 23:57:31 -05:00