Граф коммитов

54 Коммитов

Автор SHA1 Сообщение Дата
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
Pravin B Shelar 59b93b41e7 net: Remove MPLS GSO feature.
Device can export MPLS GSO support in dev->mpls_features same way
it export vlan features in dev->vlan_features. So it is safe to
remove NETIF_F_GSO_MPLS redundant flag.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
2014-11-05 23:52:33 -08:00
Pravin B Shelar de05c400f7 mpls: Allow mpls_gso to be built as module
Kconfig already allows mpls to be built as module. Following patch
fixes Makefile to do same.

CC: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-31 15:47:21 -04:00
Pravin B Shelar f7065f4bd3 mpls: Fix mpls_gso handler.
mpls gso handler needs to pull skb after segmenting skb.

CC: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-31 15:47:21 -04:00
Florian Westphal 1e16aa3ddf net: gso: use feature flag argument in all protocol gso handlers
skb_gso_segment() has a 'features' argument representing offload features
available to the output path.

A few handlers, e.g. GRE, instead re-fetch the features of skb->dev and use
those instead of the provided ones when handing encapsulation/tunnels.

Depending on dev->hw_enc_features of the output device skb_gso_segment() can
then return NULL even when the caller has disabled all GSO feature bits,
as segmentation of inner header thinks device will take care of segmentation.

This e.g. affects the tbf scheduler, which will silently drop GRE-encap GSO skbs
that did not fit the remaining token quota as the segmentation does not work
when device supports corresponding hw offload capabilities.

Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-20 12:38:12 -04:00