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>
21 #include <vnet/bier/bier_fwd.h>
24 * The arc/edge from the MPLS lookup node to the MPLS replicate node
26 extern u32 mpls_lookup_to_replicate_edge;
29 * Enum of statically configred MPLS lookup next nodes
31 typedef enum mpls_lookup_next_t_
33 MPLS_LOOKUP_NEXT_DROP = 0,
38 * We'll use it to select which adjacency to use for this flow. And other things.
41 mpls_compute_flow_hash (const mpls_unicast_header_t * hdr,
42 flow_hash_config_t flow_hash_config)
45 * We need to byte swap so we use the numerical value. i.e. an odd label
46 * leads to an odd bucket. as opposed to a label above and below value X.
48 u8 next_label_is_entropy;
49 mpls_label_t ho_label;
52 ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
53 hash = vnet_mpls_uc_get_label(ho_label);
54 next_label_is_entropy = 0;
56 while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label))
59 ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
60 value = vnet_mpls_uc_get_label(ho_label);
62 if (1 == next_label_is_entropy)
65 * The label is an entropy value, use it alone as the hash
69 if (MPLS_IETF_ENTROPY_LABEL == value)
72 * we've met a label in the stack indicating that tha next
73 * label is an entropy value
75 next_label_is_entropy = 1;
80 * XOR the label values in the stack together to
81 * build up the hash value
88 * check the top nibble for v4 and v6
92 switch (((u8*)hdr)[0] >> 4)
95 /* incorporate the v4 flow-hash */
96 hash ^= ip4_compute_flow_hash ((const ip4_header_t *)hdr,
97 IP_FLOW_HASH_DEFAULT);
100 /* incorporate the v6 flow-hash */
101 hash ^= ip6_compute_flow_hash ((const ip6_header_t *)hdr,
102 IP_FLOW_HASH_DEFAULT);
105 /* incorporate the bier flow-hash */
106 hash ^= bier_compute_flow_hash ((const bier_hdr_t *)hdr);
115 #endif /* __MPLS_LOOKUP_H__ */