Neale Ranns | 6af1c04 | 2017-05-26 03:48:53 -0700 | [diff] [blame] | 1 | /* |
| 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: |
| 6 | * |
| 7 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | * |
| 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. |
| 14 | */ |
| 15 | |
| 16 | #ifndef __MPLS_LOOKUP_H__ |
| 17 | #define __MPLS_LOOKUP_H__ |
| 18 | |
| 19 | #include <vnet/mpls/mpls.h> |
| 20 | #include <vnet/ip/ip.h> |
| 21 | |
| 22 | /** |
| 23 | * The arc/edge from the MPLS lookup node to the MPLS replicate node |
| 24 | */ |
| 25 | u32 mpls_lookup_to_replicate_edge; |
| 26 | |
Neale Ranns | ce9e0b4 | 2018-08-01 12:53:17 -0700 | [diff] [blame^] | 27 | /** |
| 28 | * Enum of statically configred MPLS lookup next nodes |
| 29 | */ |
| 30 | typedef enum mpls_lookup_next_t_ |
| 31 | { |
| 32 | MPLS_LOOKUP_NEXT_DROP = 0, |
| 33 | } mpls_lookup_next_t; |
| 34 | |
Neale Ranns | 6af1c04 | 2017-05-26 03:48:53 -0700 | [diff] [blame] | 35 | /* |
| 36 | * Compute flow hash. |
| 37 | * We'll use it to select which adjacency to use for this flow. And other things. |
| 38 | */ |
| 39 | always_inline u32 |
| 40 | mpls_compute_flow_hash (const mpls_unicast_header_t * hdr, |
| 41 | flow_hash_config_t flow_hash_config) |
| 42 | { |
| 43 | /* |
| 44 | * We need to byte swap so we use the numerical value. i.e. an odd label |
| 45 | * leads to an odd bucket. as opposed to a label above and below value X. |
| 46 | */ |
| 47 | u8 next_label_is_entropy; |
| 48 | mpls_label_t ho_label; |
| 49 | u32 hash, value; |
| 50 | |
| 51 | ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl); |
| 52 | hash = vnet_mpls_uc_get_label(ho_label); |
| 53 | next_label_is_entropy = 0; |
| 54 | |
| 55 | while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label)) |
| 56 | { |
| 57 | hdr++; |
| 58 | ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl); |
| 59 | value = vnet_mpls_uc_get_label(ho_label); |
| 60 | |
| 61 | if (1 == next_label_is_entropy) |
| 62 | { |
| 63 | /* |
| 64 | * The label is an entropy value, use it alone as the hash |
| 65 | */ |
| 66 | return (ho_label); |
| 67 | } |
| 68 | if (MPLS_IETF_ENTROPY_LABEL == value) |
| 69 | { |
| 70 | /* |
| 71 | * we've met a label in the stack indicating that tha next |
| 72 | * label is an entropy value |
| 73 | */ |
| 74 | next_label_is_entropy = 1; |
| 75 | } |
| 76 | else |
| 77 | { |
| 78 | /* |
| 79 | * XOR the label values in the stack together to |
| 80 | * build up the hash value |
| 81 | */ |
| 82 | hash ^= value; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * check the top nibble for v4 and v6 |
| 88 | */ |
| 89 | hdr++; |
| 90 | |
| 91 | switch (((u8*)hdr)[0] >> 4) |
| 92 | { |
| 93 | case 4: |
| 94 | /* incorporate the v4 flow-hash */ |
| 95 | hash ^= ip4_compute_flow_hash ((const ip4_header_t *)hdr, |
| 96 | IP_FLOW_HASH_DEFAULT); |
| 97 | break; |
| 98 | case 6: |
| 99 | /* incorporate the v6 flow-hash */ |
| 100 | hash ^= ip6_compute_flow_hash ((const ip6_header_t *)hdr, |
| 101 | IP_FLOW_HASH_DEFAULT); |
| 102 | break; |
| 103 | default: |
| 104 | break; |
| 105 | } |
| 106 | |
| 107 | return (hash); |
| 108 | } |
| 109 | |
| 110 | #endif /* __MPLS_LOOKUP_H__ */ |