linux/include/net
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
..
9p net/9p: remove a comment about pref member which doesn't exist 2014-11-06 14:59:19 -05:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-03-02 14:47:12 -05:00
caif caif: fix a signedness bug in cfpkt_iterate() 2015-02-20 17:35:14 -05:00
irda irda: Convert function pointer arrays and uses to const 2014-12-10 15:33:16 -05:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-02-05 14:33:28 -08:00
netns mpls: Basic routing support 2015-03-04 00:26:06 -05:00
nfc NFC: nci: Move logical connection structure allocation 2015-02-04 09:14:09 +01:00
phonet
sctp switch sctp_user_addto_chunk() and sctp_datamsg_from_user() to passing iov_iter 2014-11-24 05:16:40 -05:00
tc_act net: sched: Introduce connmark action 2015-01-19 16:02:06 -05:00
6lowpan.h ieee802154: 6lowpan: rename process_data and lowpan_process_data 2014-10-27 15:51:16 +01:00
act_api.h net_sched: act: refuse to remove bound action outside 2014-02-12 19:23:32 -05:00
addrconf.h net: ipv6: allow explicitly choosing optimistic addresses 2015-02-05 15:37:41 -08:00
af_ieee802154.h ieee802154: mac802154: remove FSF address 2014-10-25 08:07:30 +02:00
af_rxrpc.h af_rxrpc.h: Remove extern from function prototypes 2013-07-31 17:50:01 -07:00
af_unix.h af_unix: improve STREAM behavior with fragmented memory 2013-08-10 01:16:44 -07:00
af_vsock.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
ah.h ipsec: Remove obsolete MAX_AH_AUTH_LEN 2014-09-18 10:54:36 +02:00
arp.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
atmclip.h
ax25.h ax25: Stop using magic neighbour cache operations. 2015-03-03 14:44:41 -05:00
ax88796.h
bond_3ad.h bonding: Implement port churn-machine (AD standard 43.4.17). 2015-02-24 16:05:48 -05:00
bond_alb.h net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bond_options.h net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bonding.h net/bonding: Fix potential bad memory access during bonding events 2015-02-09 14:03:53 -08:00
busy_poll.h sched, net: Fixup busy_loop_us_clock() 2014-01-13 17:39:11 +01:00
cfg80211-wext.h
cfg80211.h nl80211: add an attribute to allow delaying the first scheduled scan cycle 2015-01-23 10:30:47 +01:00
cfg802154.h nl802154: introduce support for cca settings 2014-12-19 00:19:23 +01:00
checksum.h net: Fix remcsum in GRO path to not change packet 2015-02-11 15:12:09 -08:00
cipso_ipv4.h cipso: don't use IPCB() to locate the CIPSO IP option 2015-02-11 14:46:37 -05:00
cls_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
codel.h net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
compat.h fold verify_iovec() into copy_msghdr_from_user() 2014-11-19 16:23:49 -05:00
datalink.h net: Move prototype declaration to header file include/net/datalink.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
dcbevent.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dcbnl.h Update setapp/getapp prototypes in dcbnl_rtnl_ops to return int instead of u8 2014-07-17 16:02:29 -07:00
dn_dev.h dn_dev: add support for IFA_FLAGS nl attribute 2013-12-10 21:50:00 -05:00
dn_fib.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_neigh.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_nsp.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_route.h net: Move prototype declaration to appropriate header file from decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dn.h net: Move prototype declaration to header file include/net/dn.h from net/decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dsa.h net: dsa: Introduce dsa_is_port_initialized 2015-02-25 17:57:48 -05:00
dsfield.h ipv6: Optimize ipv6_change_dsfield(). 2013-01-09 23:59:53 -08:00
dst_ops.h percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
dst.h xfrm: Generate queueing routes only from route lookup functions 2014-09-16 10:08:49 +02:00
esp.h net: move pskb_put() to core code 2013-11-07 19:28:58 -05:00
ethoc.h net: ethoc: set up MII management bus clock 2014-02-04 20:19:51 -08:00
fib_rules.h fib_rules.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
firewire.h firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
flow_keys.h flow_keys: n_proto type should be __be16 2015-02-05 00:40:22 -08:00
flow.h ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 2014-04-16 15:05:11 -04:00
flowcache.h flowcache: Make flow cache name space aware 2014-02-12 07:02:11 +01:00
fou.h ip_tunnel: Ops registration for secondary encap (fou, gue) 2014-11-12 15:01:35 -05:00
garp.h garp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
gen_stats.h net: sched: enable per cpu qstats 2014-09-30 01:02:26 -04:00
genetlink.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-01-27 16:59:56 -08:00
geneve.h openvswitch: Add support for checksums on UDP tunnels. 2015-01-28 23:04:15 -08:00
gre.h gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
gro_cells.h ip_tunnel: Create percpu gro_cell 2015-01-18 01:56:32 -05:00
gue.h gue: Protocol constants for remote checksum offload 2014-11-05 16:30:03 -05:00
icmp.h icmp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
ieee80211_radiotap.h mac80211: propagate STBC / LDPC flags to radiotap 2014-02-06 09:34:58 +01:00
ieee802154_netdev.h ieee802154: rework cca setting 2014-12-19 00:19:23 +01:00
if_inet6.h ipv6: remove aca_lock spinlock from struct ifacaddr6 2014-10-14 13:15:15 -04:00
inet6_connection_sock.h ipv4: add a sock pointer to ip_queue_xmit() 2014-04-15 12:58:34 -04:00
inet6_hashtables.h ipv6: move INET6_MATCH() to include/net/inet6_hashtables.h 2014-11-05 16:59:04 -05:00
inet_common.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
inet_connection_sock.h net: tcp: add key management to congestion control 2015-01-05 22:55:24 -05:00
inet_ecn.h tunnel: fix RFC number in comment for INET_ECN_decapsulate() 2014-05-07 15:30:52 -04:00
inet_frag.h percpu_counter: add @gfp to percpu_counter_init() 2014-09-08 09:51:29 +09:00
inet_hashtables.h net: Use a more standard macro for INET_ADDR_COOKIE 2014-05-14 16:07:23 -04:00
inet_sock.h ip: Add offset parameter to ip_cmsg_recv 2015-01-05 22:44:46 -05:00
inet_timewait_sock.h inet: move ipv6only in sock_common 2014-07-01 23:46:21 -07:00
inetpeer.h inet: remove dead inetpeer sequence code 2014-09-08 16:42:42 -07:00
ip6_checksum.h net: add gro_compute_pseudo functions 2014-08-24 18:09:23 -07:00
ip6_fib.h net: fib6: convert cfg metric to u32 outside of table write lock 2015-01-05 22:55:24 -05:00
ip6_route.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-05-24 00:32:30 -04:00
ip6_tunnel.h tunnels: advertise link netns via netlink 2015-01-19 14:32:03 -05:00
ip_fib.h fib_trie: Convert fib_alias to hlist from list 2015-02-27 16:37:06 -05:00
ip_tunnels.h tunnels: advertise link netns via netlink 2015-01-19 14:32:03 -05:00
ip_vs.h ipvs: allow rescheduling of new connections when port reuse is detected 2015-02-25 13:46:35 +09:00
ip.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-02-05 14:33:28 -08:00
ipcomp.h
ipconfig.h
ipv6.h igmp v6: add __ipv6_sock_mc_join and __ipv6_sock_mc_drop 2015-02-27 16:25:24 -05:00
ipx.h switch ipxrtr_route_packet() from iovec to msghdr 2014-11-24 04:28:49 -05:00
iw_handler.h iw_handler.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
lapb.h lapb.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
lib80211.h lib80211: remove unused print_ssid() 2014-10-14 02:18:27 +02:00
llc_c_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_st.h llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_if.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_pdu.h net: llc: fix order of evaluation in llc_conn_ac_inc_vr_by_1 2014-01-01 22:22:43 -05:00
llc_s_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_st.h llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc.h llc: make lock static 2014-01-03 20:56:48 -05:00
mac80211.h mac80111: Add BIP-GMAC-128 and BIP-GMAC-256 ciphers 2015-01-27 11:10:13 +01:00
mac802154.h ieee802154: cleanup ieee802154_le64_to_be64 2015-02-14 05:19:58 +01:00
mip6.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
mld.h ipv6: mld: answer mldv2 queries with mldv1 reports in mldv1 fallback 2014-09-22 16:23:15 -04:00
mpls.h openvswitch: Add basic MPLS support to kernel 2014-11-05 23:52:33 -08:00
mrp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
ndisc.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
neighbour.h neigh: Add helper function neigh_xmit 2015-03-04 00:23:23 -05:00
net_namespace.h mpls: Basic routing support 2015-03-04 00:26:06 -05:00
net_ratelimit.h
netevent.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netlabel.h netlabel: fix the netlbl_catmap_setlong() dummy function 2014-08-07 20:55:21 -04:00
netlink.h netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
netprio_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
netrom.h netrom.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
nexthop.h
nl802154.h nl802154: introduce support for cca settings 2014-12-19 00:19:23 +01:00
p8022.h p8022.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
ping.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
pkt_cls.h net: sched: remove tcf_proto from ematch calls 2014-10-06 18:02:32 -04:00
pkt_sched.h net: rename vlan_tx_* helpers since "tx" is misleading there 2015-01-13 17:51:08 -05:00
protocol.h net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
psnap.h psnap.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
raw.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
rawv6.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
red.h reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
regulatory.h cfg80211: allow wiphy specific regdomain management 2014-12-17 11:49:55 +01:00
request_sock.h inet: includes a sock_common in request_sock 2013-10-10 00:08:07 -04:00
rose.h rose.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
route.h ipv4: per cpu uncached list 2015-01-15 18:26:16 -05:00
rtnetlink.h rtnl: add link netns id to interface messages 2015-01-19 14:21:26 -05:00
sch_generic.h net: sched: fix panic in rate estimators 2015-01-31 17:49:37 -08:00
scm.h scm.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
secure_seq.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
slhc_vj.h
snmp.h Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
sock.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
Space.h drivers: net: Include new header file in sbni.c 2013-12-19 18:51:20 -05:00
stp.h stp.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
switchdev.h swdevice: add new apis to set and del bridge port attributes 2015-02-01 23:16:34 -08:00
tcp_memcontrol.h tcp_memcontrol: Kill struct tcp_memcontrol 2013-10-21 18:43:02 -04:00
tcp_states.h
tcp.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
timewait_sock.h
transp_v6.h ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
tso.h net: Add a software TSO helper API 2014-05-22 14:57:15 -04:00
udp_tunnel.h udp: Do not require sock in udp_tunnel_xmit_skb 2015-01-24 23:15:40 -08:00
udp.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udplite.h net: switch memcpy_fromiovec()/memcpy_fromiovecend() users to copy_from_iter() 2015-02-04 01:34:15 -05:00
vsock_addr.h VSOCK: Move af_vsock.h and vsock_addr.h to include/net 2013-07-27 22:14:06 -07:00
vxlan.h vxlan: Use checksum partial with remote checksum offload 2015-02-11 15:12:13 -08:00
wext.h wext.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
wimax.h net: treewide: Fix typo found in DocBook/networking.xml 2014-09-05 17:35:28 -07:00
x25.h x25.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
x25device.h
xfrm.h xfrm: configure policy hash table thresholds by netlink 2014-09-02 13:37:56 +02:00