2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 #ifndef __MPLS_LOOKUP_H__
17 #define __MPLS_LOOKUP_H__
19 #include <vnet/mpls/mpls.h>
20 #include <vnet/ip/ip.h>
23 * The arc/edge from the MPLS lookup node to the MPLS replicate node
25 u32 mpls_lookup_to_replicate_edge;
29 * We'll use it to select which adjacency to use for this flow. And other things.
32 mpls_compute_flow_hash (const mpls_unicast_header_t * hdr,
33 flow_hash_config_t flow_hash_config)
36 * We need to byte swap so we use the numerical value. i.e. an odd label
37 * leads to an odd bucket. as opposed to a label above and below value X.
39 u8 next_label_is_entropy;
40 mpls_label_t ho_label;
43 ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
44 hash = vnet_mpls_uc_get_label(ho_label);
45 next_label_is_entropy = 0;
47 while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label))
50 ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
51 value = vnet_mpls_uc_get_label(ho_label);
53 if (1 == next_label_is_entropy)
56 * The label is an entropy value, use it alone as the hash
60 if (MPLS_IETF_ENTROPY_LABEL == value)
63 * we've met a label in the stack indicating that tha next
64 * label is an entropy value
66 next_label_is_entropy = 1;
71 * XOR the label values in the stack together to
72 * build up the hash value
79 * check the top nibble for v4 and v6
83 switch (((u8*)hdr)[0] >> 4)
86 /* incorporate the v4 flow-hash */
87 hash ^= ip4_compute_flow_hash ((const ip4_header_t *)hdr,
88 IP_FLOW_HASH_DEFAULT);
91 /* incorporate the v6 flow-hash */
92 hash ^= ip6_compute_flow_hash ((const ip6_header_t *)hdr,
93 IP_FLOW_HASH_DEFAULT);
102 #endif /* __MPLS_LOOKUP_H__ */