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2015-10-27mpls: reduce memory usage of routesRobert Shearman
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>
2015-10-27mpls: fix forwarding using v4/v6 explicit nullRobert Shearman
Fill in the via address length for the predefined IPv4 and IPv6 explicit-null label routes. Fixes: f8efb73c97e2 ("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>
2015-10-23mpls: flow-based multipath selectionRobert Shearman
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>
2015-10-23mpls: multipath route supportRoopa Prabhu
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>
2015-10-08dst: Pass net into dst->outputEric W. Biederman
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>
2015-08-31mpls: fix mpls_net_init memory leakNikolay Aleksandrov
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: 7720c01f3f59 ("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>
2015-08-24lwt: Add cfg argument to build_stateTom Herbert
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>
2015-08-20route: move lwtunnel state to dst_entryJiri Benc
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>
2015-08-09mpls: Enforce payload type of traffic sent using explicit NULLRobert Shearman
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>
2015-08-06af_mpls: add null dev check in find_outdevRoopa Prabhu
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>
2015-08-06mpls: small cleanup in inet/inet6_fib_lookup_dev()Dan Carpenter
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>
2015-08-03mpls: Use definition for reserved label checksRobert Shearman
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>
2015-07-31af_mpls: fix undefined reference to ip6_route_outputRoopa Prabhu
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>
2015-07-22mpls_iptunnel: fix sparse warn: remove incorrect rcu_dereferenceRoopa Prabhu
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>
2015-07-21mpls: make RTA_OIF optionalRoopa Prabhu
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>
2015-07-21mpls: ip tunnel supportRoopa Prabhu
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>
2015-07-21mpls: export mpls functions for use by mpls iptunnelsRoopa Prabhu
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2015-06-11mpls: handle device renames for per-device sysctlsRobert Shearman
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: 37bde79979c3 ("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>
2015-06-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2015-06-07mpls: fix possible use after free of deviceRobert Shearman
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: 03c57747a702 ("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>
2015-06-01net: Add priority to packet_offload objects.David S. Miller
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>
2015-05-09mpls: Change reserved label names to be consistent with netbsdTom Herbert
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>
2015-05-05mpls: Move reserved label definitionsTom Herbert
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>
2015-04-22mpls: Prevent use of implicit NULL label as outgoing labelRobert Shearman
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>
2015-04-22mpls: Per-device enabling of packet inputRobert Shearman
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>
2015-04-22mpls: Per-device MPLS stateRobert Shearman
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>
2015-03-12mpls: In mpls_egress verify the packet length.Eric W. Biederman
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>
2015-03-11mpls: Allow mpls_gso and mpls_router to be built as modulesRobert Shearman
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>
2015-03-09mpls: Spelling: s/conceved/conceived/, s/as/a/Geert Uytterhoeven
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>
2015-03-08neigh: Use neigh table index for neigh_packet_xmitEric W. Biederman
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>
2015-03-08mpls: Correct the ttl decrement.Eric W. Biederman
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>
2015-03-08mpls: Better error code for unsupported option.Eric W. Biederman
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-08mpls: Cleanup the rcu usage in the code.Eric W. Biederman
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>
2015-03-08mpls: Fix the kzalloc argument order in mpls_rt_allocEric W. Biederman
*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>
2015-03-06mpls: Properly validate RTA_VIA payload lengthRobert Shearman
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: 03c0566542f4 ("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>
2015-03-05mpls: using vzalloc requires including vmalloc.hStephen Rothwell
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: 7720c01f3f59 ("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>
2015-03-04mpls: rtm_mpls_policy[] can be staticWu Fengguang
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04mpls: Multicast route table change notificationsEric W. Biederman
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>
2015-03-04mpls: Netlink commands to add, remove, and dump routesEric W. Biederman
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>
2015-03-04mpls: Functions for reading and wrinting mpls labels over netlinkEric W. Biederman
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>
2015-03-04mpls: Basic support for adding and removing routesEric W. Biederman
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>
2015-03-04mpls: Add a sysctl to control the size of the mpls label tableEric W. Biederman
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>
2015-03-04mpls: Basic routing supportEric W. Biederman
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>
2015-03-04mpls: Refactor how the mpls module is builtEric W. Biederman
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>
2015-01-30net: mark some potential candidates __read_mostlyDaniel Borkmann
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>
2014-12-23mpls: Fix allowed protocols for mpls gsoPravin B Shelar
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>
2014-11-05net: Remove MPLS GSO feature.Pravin B Shelar
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>
2014-10-31mpls: Allow mpls_gso to be built as modulePravin B Shelar
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>
2014-10-31mpls: Fix mpls_gso handler.Pravin B Shelar
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>