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Vector Packet Processing
mpls_lookup.h
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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 #include <vnet/bier/bier_fwd.h>
22 #include <vnet/ip/ip4_inlines.h>
23 #include <vnet/ip/ip6_inlines.h>
24 
25 /**
26  * The arc/edge from the MPLS lookup node to the MPLS replicate node
27  */
29 
30 /**
31  * Enum of statically configred MPLS lookup next nodes
32  */
33 typedef enum mpls_lookup_next_t_
34 {
37 
38 /*
39  * Compute flow hash.
40  * We'll use it to select which adjacency to use for this flow. And other things.
41  */
44  flow_hash_config_t flow_hash_config)
45 {
46  /*
47  * We need to byte swap so we use the numerical value. i.e. an odd label
48  * leads to an odd bucket. as opposed to a label above and below value X.
49  */
50  u8 next_label_is_entropy;
51  mpls_label_t ho_label;
52  u32 hash, value;
53 
54  ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
55  hash = vnet_mpls_uc_get_label(ho_label);
56  hash ^= ip_flow_hash_router_id;
57  next_label_is_entropy = 0;
58 
59  while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label))
60  {
61  hdr++;
62  ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
63  value = vnet_mpls_uc_get_label(ho_label);
64 
65  if (1 == next_label_is_entropy)
66  {
67  /*
68  * The label is an entropy value, use it alone as the hash
69  */
70  return (ho_label);
71  }
73  {
74  /*
75  * we've met a label in the stack indicating that tha next
76  * label is an entropy value
77  */
78  next_label_is_entropy = 1;
79  }
80  else
81  {
82  /*
83  * XOR the label values in the stack together to
84  * build up the hash value
85  */
86  hash ^= value;
87  }
88  }
89 
90  /*
91  * check the top nibble for v4 and v6
92  */
93  hdr++;
94 
95  switch (((u8*)hdr)[0] >> 4)
96  {
97  case 4:
98  /* incorporate the v4 flow-hash */
99  hash ^=
100  ip4_compute_flow_hash ((const ip4_header_t *) hdr, flow_hash_config);
101  break;
102  case 6:
103  /* incorporate the v6 flow-hash */
104  hash ^=
105  ip6_compute_flow_hash ((const ip6_header_t *) hdr, flow_hash_config);
106  break;
107  case 5:
108  /* incorporate the bier flow-hash */
109  hash ^= bier_compute_flow_hash ((const bier_hdr_t *)hdr);
110  break;
111  default:
112  break;
113  }
114 
115  return (hash);
116 }
117 
118 #endif /* __MPLS_LOOKUP_H__ */
vnet_mpls_uc_get_s
static u32 vnet_mpls_uc_get_s(mpls_label_t label_exp_s_ttl)
Definition: packet.h:115
ip4_inlines.h
mpls_unicast_header_t
Definition: packet.h:28
MPLS_EOS
@ MPLS_EOS
Definition: packet.h:39
vnet_mpls_uc_get_label
static u32 vnet_mpls_uc_get_label(mpls_label_t label_exp_s_ttl)
Definition: packet.h:105
mpls.h
ip_flow_hash_router_id
u32 ip_flow_hash_router_id
Definition: ip.c:19
ip4_header_t
Definition: ip4_packet.h:87
bier_fwd.h
ip6_compute_flow_hash
static u32 ip6_compute_flow_hash(const ip6_header_t *ip, flow_hash_config_t flow_hash_config)
Definition: ip6_inlines.h:49
mpls_lookup_next_t_
mpls_lookup_next_t_
Enum of statically configred MPLS lookup next nodes.
Definition: mpls_lookup.h:33
flow_hash_config_t
enum flow_hash_config_t_ flow_hash_config_t
A flow hash configuration is a mask of the flow hash options.
MPLS_IETF_ENTROPY_LABEL
#define MPLS_IETF_ENTROPY_LABEL
Definition: mpls_types.h:33
mpls_compute_flow_hash
static u32 mpls_compute_flow_hash(const mpls_unicast_header_t *hdr, flow_hash_config_t flow_hash_config)
Definition: mpls_lookup.h:43
ip6_inlines.h
bier_compute_flow_hash
static_always_inline u32 bier_compute_flow_hash(const bier_hdr_t *hdr)
Definition: bier_fwd.h:23
always_inline
#define always_inline
Definition: rdma_mlx5dv.h:23
ip.h
u32
unsigned int u32
Definition: types.h:88
MPLS_LOOKUP_NEXT_DROP
@ MPLS_LOOKUP_NEXT_DROP
Definition: mpls_lookup.h:35
value
u8 value
Definition: qos.api:54
ip4_compute_flow_hash
static u32 ip4_compute_flow_hash(const ip4_header_t *ip, flow_hash_config_t flow_hash_config)
Definition: ip4_inlines.h:51
ip6_header_t
Definition: ip6_packet.h:294
mpls_unicast_header_t::label_exp_s_ttl
mpls_label_t label_exp_s_ttl
Definition: packet.h:33
u8
unsigned char u8
Definition: types.h:56
bier_hdr_t_
A BIER header of variable length The encoding follows: https://tools.ietf.org/html/draft-ietf-bier-mp...
Definition: bier_types.h:321
mpls_label_t
u32 mpls_label_t
A label value only, i.e.
Definition: packet.h:26
mpls_lookup_next_t
enum mpls_lookup_next_t_ mpls_lookup_next_t
Enum of statically configred MPLS lookup next nodes.
mpls_lookup_to_replicate_edge
u32 mpls_lookup_to_replicate_edge
The arc/edge from the MPLS lookup node to the MPLS replicate node.
Definition: mpls_lookup.c:28