summaryrefslogtreecommitdiffstats
path: root/src/vnet/adj/adj_nbr.c
blob: ff535295b4b8e7461c7ae7fde240219dcb984d42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189

@media only all and (prefers-color-scheme: dark) {
.highlight .hll { background-color: #49483e }
.highlight .c { color: #75715e } /* Comment */
.highlight .err { color: #960050; background-color: #1e0010 } /* Error */
.highlight .k { color: #66d9ef } /* Keyword */
.highlight .l { color: #ae81ff } /* Literal */
.highlight .n { color: #f8f8f2 } /* Name */
.highlight .o { color: #f92672 } /* Operator */
.highlight .p { color: #f8f8f2 } /* Punctuation */
.highlight .ch { color: #75715e } /* Comment.Hashbang */
.highlight .cm { color: #75715e } /* Comment.Multiline */
.highlight .cp { color: #75715e } /* Comment.Preproc */
.highlight .cpf { color: #75715e } /* Comment.PreprocFile */
.highlight .c1 { color: #75715e } /* Comment.Single */
.highlight .cs { color: #75715e } /* Comment.Special */
.highlight .gd { color: #f92672 } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .gi { color: #a6e22e } /* Generic.Inserted */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #75715e } /* Generic.Subheading */
.highlight .kc { color: #66d9ef } /* Keyword.Constant */
.highlight .kd { color: #66d9ef } /* Keyword.Declaration */
.highlight .kn { color: #f92672 } /* Keyword.Namespace */
.highlight .kp { color: #66d9ef } /* Keyword.Pseudo */
.highlight .kr { color: #66d9ef } /* Keyword.Reserved */
.highlight .kt { color: #66d9ef } /* Keyword.Type */
.highlight .ld { color: #e6db74 } /* Literal.Date */
.highlight .m { color: #ae81ff } /* Literal.Number */
.highlight .s { color: #e6db74 } /* Literal.String */
.highlight .na { color: #a6e22e } /* Name.Attribute */
.highlight .nb { color: #f8f8f2 } /* Name.Builtin */
.highlight .nc { color: #a6e22e } /* Name.Class */
.highlight .no { color: #66d9ef } /* Name.Constant */
.highlight .nd { color: #a6e22e } /* Name.Decorator */
.highlight .ni { color: #f8f8f2 } /* Name.Entity */
.highlight .ne { color: #a6e22e } /* Name.Exception */
.highlight .nf { color: #a6e22e } /* Name.Function */
.highlight .nl { color: #f8f8f2 } /* Name.Label */
.highlight .nn { color: #f8f8f2 } /* Name.Namespace */
.highlight .nx { color: #a6e22e } /* Name.Other */
.highlight .py { color: #f8f8f2 } /* Name.Property */
.highlight .nt { color: #f92672 } /* Name.Tag */
.highlight .nv { color: #f8f8f2 } /* Name.Variable */
.highlight .ow { color: #f92672 } /* Operator.Word */
.highlight .w { color: #f8f8f2 } /* Text.Whitespace */
.highlight .mb { color: #ae81ff } /* Literal.Number.Bin */
.highlight .mf { color: #ae81ff } /* Literal.Number.Float */
.highlight .mh { color: #ae81ff } /* Literal.Number.Hex */
.highlight .mi { color: #ae81ff } /* Literal.Number.Integer */
.highlight .mo { color: #ae81ff } /* Literal.Number.Oct */
.highlight .sa { color: #e6db74 } /* Literal.String.Affix */
.highlight .sb { color: #e6db74 } /* Literal.String.Backtick */
.highlight .sc { color: #e6db74 } /* Literal.String.Char */
.highlight .dl { color: #e6db74 } /* Literal.String.Delimiter */
.highlight .sd { color: #e6db74 } /* Literal.String.Doc */
.highlight .s2 { color: #e6db74 } /* Literal.String.Double */
.highlight .se { color: #ae81ff } /* Literal.String.Escape */
.highlight .sh { color: #e6db74 } /* Literal.String.Heredoc */
.highlight .si { color: #e6db74 } /* Literal.String.Interpol */
.highlight .sx { color: #e6db74 } /* Literal.String.Other */
.highlight .sr { color: #e6db74 } /* Literal.String.Regex */
.highlight .s1 { color: #e6db74 } /* Literal.String.Single */
.highlight .ss { color: #e6db74 } /* Literal.String.Symbol */
.highlight .bp { color: #f8f8f2 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #a6e22e } /* Name.Function.Magic */
.highlight .vc { color: #f8f8f2 } /* Name.Variable.Class */
.highlight .vg { color: #f8f8f2 } /* Name.Variable.Global */
.highlight .vi { color: #f8f8f2 } /* Name.Variable.Instance */
.highlight .vm { color: #f8f8f2 } /* Name.Variable.Magic */
.highlight .il { color: #ae81ff } /* Literal.Number.Integer.Long */
}
@media (prefers-color-scheme: light) {
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
}
                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).

      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

   END OF TERMS AND CONDITIONS

   APPENDIX: How to apply the Apache License to your work.

      To apply the Apache License to your work, attach the following
      boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier
      identification within third-party archives.

   Copyright [yyyy] [name of copyright owner]

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
id='n817' href='#n817'>817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <vnet/adj/adj_nbr.h>
#include <vnet/adj/adj_internal.h>
#include <vnet/ethernet/arp_packet.h>
#include <vnet/fib/fib_walk.h>

/*
 * Vector Hash tables of neighbour (traditional) adjacencies
 *  Key: interface(for the vector index), address (and its proto),
 *       link-type/ether-type.
 */
static BVT(clib_bihash) **adj_nbr_tables[FIB_PROTOCOL_MAX];

// FIXME SIZE APPROPRIATELY. ASK DAVEB.
#define ADJ_NBR_DEFAULT_HASH_NUM_BUCKETS (64 * 64)
#define ADJ_NBR_DEFAULT_HASH_MEMORY_SIZE (32<<20)


#define ADJ_NBR_SET_KEY(_key, _lt, _nh)         \
{						\
    _key.key[0] = (_nh)->as_u64[0];		\
    _key.key[1] = (_nh)->as_u64[1];		\
    _key.key[2] = (_lt);			\
}

#define ADJ_NBR_ITF_OK(_proto, _itf)			\
    (((_itf) < vec_len(adj_nbr_tables[_proto])) &&	\
     (NULL != adj_nbr_tables[_proto][sw_if_index]))

static void
adj_nbr_insert (fib_protocol_t nh_proto,
		vnet_link_t link_type,
		const ip46_address_t *nh_addr,
		u32 sw_if_index,
		adj_index_t adj_index)
{
    BVT(clib_bihash_kv) kv;

    if (sw_if_index >= vec_len(adj_nbr_tables[nh_proto]))
    {
	vec_validate(adj_nbr_tables[nh_proto], sw_if_index);
    }
    if (NULL == adj_nbr_tables[nh_proto][sw_if_index])
    {
	adj_nbr_tables[nh_proto][sw_if_index] =
	    clib_mem_alloc_aligned(sizeof(BVT(clib_bihash)),
				   CLIB_CACHE_LINE_BYTES);
	clib_memset(adj_nbr_tables[nh_proto][sw_if_index],
	       0,
	       sizeof(BVT(clib_bihash)));

	BV(clib_bihash_init) (adj_nbr_tables[nh_proto][sw_if_index],
			      "Adjacency Neighbour table",
			      ADJ_NBR_DEFAULT_HASH_NUM_BUCKETS,
			      ADJ_NBR_DEFAULT_HASH_MEMORY_SIZE);
    }

    ADJ_NBR_SET_KEY(kv, link_type, nh_addr);
    kv.value = adj_index;

    BV(clib_bihash_add_del) (adj_nbr_tables[nh_proto][sw_if_index], &kv, 1);
}

void
adj_nbr_remove (adj_index_t ai,
                fib_protocol_t nh_proto,
		vnet_link_t link_type,
		const ip46_address_t *nh_addr,
		u32 sw_if_index)
{
    BVT(clib_bihash_kv) kv;

    if (!ADJ_NBR_ITF_OK(nh_proto, sw_if_index))
	return;

    ADJ_NBR_SET_KEY(kv, link_type, nh_addr);
    kv.value = ai;

    BV(clib_bihash_add_del) (adj_nbr_tables[nh_proto][sw_if_index], &kv, 0);
}

adj_index_t
adj_nbr_find (fib_protocol_t nh_proto,
	      vnet_link_t link_type,
	      const ip46_address_t *nh_addr,
	      u32 sw_if_index)
{
    BVT(clib_bihash_kv) kv;

    ADJ_NBR_SET_KEY(kv, link_type, nh_addr);

    if (!ADJ_NBR_ITF_OK(nh_proto, sw_if_index))
	return (ADJ_INDEX_INVALID);

    if (BV(clib_bihash_search)(adj_nbr_tables[nh_proto][sw_if_index],
			       &kv, &kv) < 0)
    {
	return (ADJ_INDEX_INVALID);
    }
    else
    {
	return (kv.value);
    }
}

static inline u32
adj_get_nd_node (fib_protocol_t proto)
{
    switch (proto) {
    case FIB_PROTOCOL_IP4:
	return (ip4_arp_node.index);
    case FIB_PROTOCOL_IP6:
	return (ip6_discover_neighbor_node.index);
    case FIB_PROTOCOL_MPLS:
	break;
    }
    ASSERT(0);
    return (ip4_arp_node.index);
}

/**
 * @brief Check and set feature flags if o/p interface has any o/p features.
 */
static void
adj_nbr_evaluate_feature (adj_index_t ai)
{
    ip_adjacency_t *adj;
    vnet_feature_main_t *fm = &feature_main;
    i16 feature_count;
    u8 arc_index;
    u32 sw_if_index;

    adj = adj_get(ai);

    switch (adj->ia_link)
    {
    case VNET_LINK_IP4:
        arc_index = ip4_main.lookup_main.output_feature_arc_index;
        break;
    case VNET_LINK_IP6:
        arc_index = ip6_main.lookup_main.output_feature_arc_index;
        break;
    case VNET_LINK_MPLS:
        arc_index = mpls_main.output_feature_arc_index;
        break;
    default:
        return;
    }

    sw_if_index = adj->rewrite_header.sw_if_index;
    if (vec_len(fm->feature_count_by_sw_if_index[arc_index]) > sw_if_index)
    {
        feature_count = fm->feature_count_by_sw_if_index[arc_index][sw_if_index];
        if (feature_count > 0)
            adj->rewrite_header.flags |= VNET_REWRITE_HAS_FEATURES;
    }

    return;
}

static ip_adjacency_t*
adj_nbr_alloc (fib_protocol_t nh_proto,
	       vnet_link_t link_type,
	       const ip46_address_t *nh_addr,
	       u32 sw_if_index)
{
    ip_adjacency_t *adj;

    adj = adj_alloc(nh_proto);

    adj_nbr_insert(nh_proto, link_type, nh_addr,
		   sw_if_index,
		   adj_get_index(adj));

    /*
     * since we just added the ADJ we have no rewrite string for it,
     * so its for ARP
     */
    adj->lookup_next_index = IP_LOOKUP_NEXT_ARP;
    adj->sub_type.nbr.next_hop = *nh_addr;
    adj->ia_link = link_type;
    adj->ia_nh_proto = nh_proto;
    adj->rewrite_header.sw_if_index = sw_if_index;

    adj_nbr_evaluate_feature (adj_get_index(adj));
    return (adj);
}

/*
 * adj_nbr_add_or_lock
 *
 * Add an adjacency for the neighbour requested.
 *
 * The key for an adj is:
 *   - the Next-hops protocol (i.e. v4 or v6)
 *   - the address of the next-hop
 *   - the interface the next-hop is reachable through
 */
adj_index_t
adj_nbr_add_or_lock (fib_protocol_t nh_proto,
		     vnet_link_t link_type,
		     const ip46_address_t *nh_addr,
		     u32 sw_if_index)
{
    adj_index_t adj_index;
    ip_adjacency_t *adj;

    adj_index = adj_nbr_find(nh_proto, link_type, nh_addr, sw_if_index);

    if (ADJ_INDEX_INVALID == adj_index)
    {
	vnet_main_t *vnm;

	vnm = vnet_get_main();
	adj = adj_nbr_alloc(nh_proto, link_type, nh_addr, sw_if_index);
	adj_index = adj_get_index(adj);
	adj_lock(adj_index);

        if (ip46_address_is_equal(&ADJ_BCAST_ADDR, nh_addr))
        {
            adj->lookup_next_index = IP_LOOKUP_NEXT_BCAST;
        }

	vnet_rewrite_init(vnm, sw_if_index, link_type,
			  adj_get_nd_node(nh_proto),
			  vnet_tx_node_index_for_sw_interface(vnm, sw_if_index),
			  &adj->rewrite_header);

	/*
	 * we need a rewrite where the destination IP address is converted
	 * to the appropriate link-layer address. This is interface specific.
	 * So ask the interface to do it.
	 */
	vnet_update_adjacency_for_sw_interface(vnm, sw_if_index, adj_index);
    }
    else
    {
	adj_lock(adj_index);
    }

    return (adj_index);
}

adj_index_t
adj_nbr_add_or_lock_w_rewrite (fib_protocol_t nh_proto,
			       vnet_link_t link_type,
			       const ip46_address_t *nh_addr,
			       u32 sw_if_index,
			       u8 *rewrite)
{
    adj_index_t adj_index;
    ip_adjacency_t *adj;

    adj_index = adj_nbr_find(nh_proto, link_type, nh_addr, sw_if_index);

    if (ADJ_INDEX_INVALID == adj_index)
    {
	adj = adj_nbr_alloc(nh_proto, link_type, nh_addr, sw_if_index);
	adj->rewrite_header.sw_if_index = sw_if_index;
    }
    else
    {
        adj = adj_get(adj_index);
    }

    adj_lock(adj_get_index(adj));
    adj_nbr_update_rewrite(adj_get_index(adj),
			   ADJ_NBR_REWRITE_FLAG_COMPLETE,
			   rewrite);

    return (adj_get_index(adj));
}

/**
 * adj_nbr_update_rewrite
 *
 * Update the adjacency's rewrite string. A NULL string implies the
 * rewirte is reset (i.e. when ARP/ND etnry is gone).
 * NB: the adj being updated may be handling traffic in the DP.
 */
void
adj_nbr_update_rewrite (adj_index_t adj_index,
			adj_nbr_rewrite_flag_t flags,
			u8 *rewrite)
{
    ip_adjacency_t *adj;

    ASSERT(ADJ_INDEX_INVALID != adj_index);

    adj = adj_get(adj_index);

    if (flags & ADJ_NBR_REWRITE_FLAG_COMPLETE)
    {
	/*
	 * update the adj's rewrite string and build the arc
	 * from the rewrite node to the interface's TX node
	 */
	adj_nbr_update_rewrite_internal(adj, IP_LOOKUP_NEXT_REWRITE,
					adj_get_rewrite_node(adj->ia_link),
					vnet_tx_node_index_for_sw_interface(
					    vnet_get_main(),
					    adj->rewrite_header.sw_if_index),
					rewrite);
    }
    else
    {
	adj_nbr_update_rewrite_internal(adj, IP_LOOKUP_NEXT_ARP,
					adj_get_nd_node(adj->ia_nh_proto),
					vnet_tx_node_index_for_sw_interface(
					    vnet_get_main(),
					    adj->rewrite_header.sw_if_index),
					rewrite);
    }
}

/**
 * adj_nbr_update_rewrite_internal
 *
 * Update the adjacency's rewrite string. A NULL string implies the
 * rewirte is reset (i.e. when ARP/ND etnry is gone).
 * NB: the adj being updated may be handling traffic in the DP.
 */
void
adj_nbr_update_rewrite_internal (ip_adjacency_t *adj,
				 ip_lookup_next_t adj_next_index,
				 u32 this_node,
				 u32 next_node,
				 u8 *rewrite)
{
    ip_adjacency_t *walk_adj;
    adj_index_t walk_ai;
    vlib_main_t * vm;
    u32 old_next;
    int do_walk;

    vm = vlib_get_main();
    old_next = adj->lookup_next_index;

    walk_ai = adj_get_index(adj);
    if (VNET_LINK_MPLS == adj->ia_link)
    {
        /*
         * The link type MPLS has no children in the control plane graph, it only
         * has children in the data-palne graph. The backwalk is up the former.
         * So we need to walk from its IP cousin.
         */
        walk_ai = adj_nbr_find(adj->ia_nh_proto,
                               fib_proto_to_link(adj->ia_nh_proto),
                               &adj->sub_type.nbr.next_hop,
                               adj->rewrite_header.sw_if_index);
    }

    /*
     * Don't call the walk re-entrantly
     */
    if (ADJ_INDEX_INVALID != walk_ai)
    {
        walk_adj = adj_get(walk_ai);
        if (ADJ_FLAG_SYNC_WALK_ACTIVE & walk_adj->ia_flags)
        {
            do_walk = 0;
        }
        else
        {
            /*
             * Prevent re-entrant walk of the same adj
             */
            walk_adj->ia_flags |= ADJ_FLAG_SYNC_WALK_ACTIVE;
            do_walk = 1;
        }
    }
    else
    {
        do_walk = 0;
    }

    /*
     * lock the adjacencies that are affected by updates this walk will provoke.
     * Since the aim of the walk is to update children to link to a different
     * DPO, this adj will no longer be in use and its lock count will drop to 0.
     * We don't want it to be deleted as part of this endevour.
     */
    adj_lock(adj_get_index(adj));
    adj_lock(walk_ai);

    /*
     * Updating a rewrite string is not atomic;
     *  - the rewrite string is too long to write in one instruction
     *  - when swapping from incomplete to complete, we also need to update
     *    the VLIB graph next-index of the adj.
     * ideally we would only want to suspend forwarding via this adj whilst we
     * do this, but we do not have that level of granularity - it's suspend all
     * worker threads or nothing.
     * The other chioces are:
     *  - to mark the adj down and back walk so child load-balances drop this adj
     *    from the set.
     *  - update the next_node index of this adj to point to error-drop
     * both of which will mean for MAC change we will drop for this adj
     * which is not acceptable. However, when the adj changes type (from
     * complete to incomplete and vice-versa) the child DPOs, which have the
     * VLIB graph next node index, will be sending packets to the wrong graph
     * node. So from the options above, updating the next_node of the adj to
     * be drop will work, but it relies on each graph node v4/v6/mpls, rewrite/
     * arp/midchain always be valid w.r.t. a mis-match of adj type and node type
     * (i.e. a rewrite adj in the arp node). This is not enforcable. Getting it
     * wrong will lead to hard to find bugs since its a race condition. So we
     * choose the more reliable method of updating the children to use the drop,
     * then switching adj's type, then updating the children again. Did I mention
     * that this doesn't happen often...
     * So we need to distinguish between the two cases:
     *  1 - mac change
     *  2 - adj type change
     */
    if (do_walk &&
        old_next != adj_next_index &&
        ADJ_INDEX_INVALID != walk_ai)
    {
        /*
         * the adj is changing type. we need to fix all children so that they
         * stack momentarily on a drop, while the adj changes. If we don't do
         * this  the children will send packets to a VLIB graph node that does
         * not correspond to the adj's type - and it goes downhill from there.
         */
	fib_node_back_walk_ctx_t bw_ctx = {
	    .fnbw_reason = FIB_NODE_BW_REASON_FLAG_ADJ_DOWN,
            /*
             * force this walk to be synchrous. if we don't and a node in the graph
             * (a heavily shared path-list) chooses to back-ground the walk (make it
             * async) then it will pause and we will do the adj update below, before
             * all the children are updated. not good.
             */
            .fnbw_flags = FIB_NODE_BW_FLAG_FORCE_SYNC,
	};

	fib_walk_sync(FIB_NODE_TYPE_ADJ, walk_ai, &bw_ctx);
    }

    /*
     * If we are just updating the MAC string of the adj (which we also can't
     * do atomically), then we need to stop packets switching through the adj.
     * We can't do that on a per-adj basis, so it's all the packets.
     * If we are updating the type, and we walked back to the children above,
     * then this barrier serves to flush the queues/frames.
     */
    vlib_worker_thread_barrier_sync(vm);

    adj->lookup_next_index = adj_next_index;

    if (NULL != rewrite)
    {
	/*
	 * new rewrite provided.
	 * fill in the adj's rewrite string, and build the VLIB graph arc.
	 */
	vnet_rewrite_set_data_internal(&adj->rewrite_header,
				       sizeof(adj->rewrite_data),
				       rewrite,
				       vec_len(rewrite));
	vec_free(rewrite);
    }
    else
    {
	vnet_rewrite_clear_data_internal(&adj->rewrite_header,
					 sizeof(adj->rewrite_data));
    }
    adj->rewrite_header.next_index = vlib_node_add_next(vlib_get_main(),
                                                        this_node,
                                                        next_node);

    /*
     * done with the rewirte update - let the workers loose.
     */
    vlib_worker_thread_barrier_release(vm);

    if (do_walk &&
        (old_next != adj->lookup_next_index) &&
        (ADJ_INDEX_INVALID != walk_ai))
    {
        /*
         * backwalk to the children so they can stack on the now updated
         * adjacency
         */
        fib_node_back_walk_ctx_t bw_ctx = {
	    .fnbw_reason = FIB_NODE_BW_REASON_FLAG_ADJ_UPDATE,
	};

	fib_walk_sync(FIB_NODE_TYPE_ADJ, walk_ai, &bw_ctx);
    }
    /*
     * Prevent re-entrant walk of the same adj
     */
    if (do_walk)
    {
        walk_adj->ia_flags &= ~ADJ_FLAG_SYNC_WALK_ACTIVE;
    }

    adj_unlock(adj_get_index(adj));
    adj_unlock(walk_ai);
}

typedef struct adj_db_count_ctx_t_ {
    u64 count;
} adj_db_count_ctx_t;

static void
adj_db_count (BVT(clib_bihash_kv) * kvp,
	      void *arg)
{
    adj_db_count_ctx_t * ctx = arg;
    ctx->count++;
}

u32
adj_nbr_db_size (void)
{
    adj_db_count_ctx_t ctx = {
	.count = 0,
    };
    fib_protocol_t proto;
    u32 sw_if_index = 0;

    for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
    {
	vec_foreach_index(sw_if_index, adj_nbr_tables[proto])
	{
	    if (NULL != adj_nbr_tables[proto][sw_if_index])
	    {
		BV(clib_bihash_foreach_key_value_pair) (
		    adj_nbr_tables[proto][sw_if_index],
		    adj_db_count,
		    &ctx);
	    }
	}
    }
    return (ctx.count);
}

/**
 * @brief Context for a walk of the adjacency neighbour DB
 */
typedef struct adj_walk_ctx_t_
{
    adj_walk_cb_t awc_cb;
    void *awc_ctx;
} adj_walk_ctx_t;

static void
adj_nbr_walk_cb (BVT(clib_bihash_kv) * kvp,
		 void *arg)
{
    adj_walk_ctx_t *ctx = arg;

    // FIXME: can't stop early...
    ctx->awc_cb(kvp->value, ctx->awc_ctx);
}

void
adj_nbr_walk (u32 sw_if_index,
	      fib_protocol_t adj_nh_proto,
	      adj_walk_cb_t cb,
	      void *ctx)
{
    if (!ADJ_NBR_ITF_OK(adj_nh_proto, sw_if_index))
	return;

    adj_walk_ctx_t awc = {
	.awc_ctx = ctx,
	.awc_cb = cb,
    };

    BV(clib_bihash_foreach_key_value_pair) (
	adj_nbr_tables[adj_nh_proto][sw_if_index],
	adj_nbr_walk_cb,
	&awc);
}

/**
 * @brief Walk adjacencies on a link with a given v4 next-hop.
 * that is visit the adjacencies with different link types.
 */
void
adj_nbr_walk_nh4 (u32 sw_if_index,
		 const ip4_address_t *addr,
		 adj_walk_cb_t cb,
		 void *ctx)
{
    if (!ADJ_NBR_ITF_OK(FIB_PROTOCOL_IP4, sw_if_index))
	return;

    ip46_address_t nh = {
	.ip4 = *addr,
    };
    vnet_link_t linkt;
    adj_index_t ai;

    FOR_EACH_VNET_LINK(linkt)
    {
        ai = adj_nbr_find (FIB_PROTOCOL_IP4, linkt, &nh, sw_if_index);

        if (INDEX_INVALID != ai)
            cb(ai, ctx);
    }
}

/**
 * @brief Walk adjacencies on a link with a given v6 next-hop.
 * that is visit the adjacencies with different link types.
 */
void
adj_nbr_walk_nh6 (u32 sw_if_index,
		 const ip6_address_t *addr,
		 adj_walk_cb_t cb,
		 void *ctx)
{
    if (!ADJ_NBR_ITF_OK(FIB_PROTOCOL_IP6, sw_if_index))
	return;

    ip46_address_t nh = {
	.ip6 = *addr,
    };
    vnet_link_t linkt;
    adj_index_t ai;

    FOR_EACH_VNET_LINK(linkt)
    {
        ai = adj_nbr_find (FIB_PROTOCOL_IP6, linkt, &nh, sw_if_index);

        if (INDEX_INVALID != ai)
            cb(ai, ctx);
    }
}

/**
 * @brief Walk adjacencies on a link with a given next-hop.
 * that is visit the adjacencies with different link types.
 */
void
adj_nbr_walk_nh (u32 sw_if_index,
		 fib_protocol_t adj_nh_proto,
		 const ip46_address_t *nh,
		 adj_walk_cb_t cb,
		 void *ctx)
{
    if (!ADJ_NBR_ITF_OK(adj_nh_proto, sw_if_index))
	return;

    vnet_link_t linkt;
    adj_index_t ai;

    FOR_EACH_VNET_LINK(linkt)
    {
        ai = adj_nbr_find (FIB_PROTOCOL_IP4, linkt, nh, sw_if_index);

        if (INDEX_INVALID != ai)
            cb(ai, ctx);
    }
}

/**
 * Flags associated with the interface state walks
 */
typedef enum adj_nbr_interface_flags_t_
{
    ADJ_NBR_INTERFACE_UP = (1 << 0),
} adj_nbr_interface_flags_t;

/**
 * Context for the state change walk of the DB
 */
typedef struct adj_nbr_interface_state_change_ctx_t_
{
    /**
     * Flags on the interface
     */
    adj_nbr_interface_flags_t flags;
} adj_nbr_interface_state_change_ctx_t;

static adj_walk_rc_t
adj_nbr_interface_state_change_one (adj_index_t ai,
                                    void *arg)
{
    /*
     * Back walk the graph to inform the forwarding entries
     * that this interface state has changed. Do this synchronously
     * since this is the walk that provides convergence
     */
    adj_nbr_interface_state_change_ctx_t *ctx = arg;
    fib_node_back_walk_ctx_t bw_ctx = {
	.fnbw_reason = ((ctx->flags & ADJ_NBR_INTERFACE_UP) ?
                        FIB_NODE_BW_REASON_FLAG_INTERFACE_UP :
                        FIB_NODE_BW_REASON_FLAG_INTERFACE_DOWN),
        /*
         * the force sync applies only as far as the first fib_entry.
         * And it's the fib_entry's we need to converge away from
         * the adjacencies on the now down link
         */
        .fnbw_flags = (!(ctx->flags & ADJ_NBR_INTERFACE_UP) ?
                       FIB_NODE_BW_FLAG_FORCE_SYNC :
                       FIB_NODE_BW_FLAG_NONE),
    };
    ip_adjacency_t *adj;

    adj = adj_get(ai);

    adj->ia_flags |= ADJ_FLAG_SYNC_WALK_ACTIVE;
    fib_walk_sync(FIB_NODE_TYPE_ADJ, ai, &bw_ctx);
    adj->ia_flags &= ~ADJ_FLAG_SYNC_WALK_ACTIVE;

    return (ADJ_WALK_RC_CONTINUE);
}

/**
 * @brief Registered function for SW interface state changes
 */
static clib_error_t *
adj_nbr_sw_interface_state_change (vnet_main_t * vnm,
                                   u32 sw_if_index,
                                   u32 flags)
{
    fib_protocol_t proto;

    /*
     * walk each adj on the interface and trigger a walk from that adj
     */
    for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
    {
	adj_nbr_interface_state_change_ctx_t ctx = {
	    .flags = ((flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ?
                      ADJ_NBR_INTERFACE_UP :
                      0),
	};

	adj_nbr_walk(sw_if_index, proto,
		     adj_nbr_interface_state_change_one,
		     &ctx);
    }

    return (NULL);
}

VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION_PRIO(
    adj_nbr_sw_interface_state_change,
    VNET_ITF_FUNC_PRIORITY_HIGH);

/**
 * @brief Invoked on each SW interface of a HW interface when the
 * HW interface state changes
 */
static walk_rc_t
adj_nbr_hw_sw_interface_state_change (vnet_main_t * vnm,
                                      u32 sw_if_index,
                                      void *arg)
{
    adj_nbr_interface_state_change_ctx_t *ctx = arg;
    fib_protocol_t proto;

    /*
     * walk each adj on the interface and trigger a walk from that adj
     */
    for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
    {
	adj_nbr_walk(sw_if_index, proto,
		     adj_nbr_interface_state_change_one,
		     ctx);
    }
    return (WALK_CONTINUE);
}

/**
 * @brief Registered callback for HW interface state changes
 */
static clib_error_t *
adj_nbr_hw_interface_state_change (vnet_main_t * vnm,
                                   u32 hw_if_index,
                                   u32 flags)
{
    /*
     * walk SW interface on the HW
     */
    adj_nbr_interface_state_change_ctx_t ctx = {
        .flags = ((flags & VNET_HW_INTERFACE_FLAG_LINK_UP) ?
                  ADJ_NBR_INTERFACE_UP :
                  0),
    };

    vnet_hw_interface_walk_sw(vnm, hw_if_index,
                              adj_nbr_hw_sw_interface_state_change,
                              &ctx);

    return (NULL);
}

VNET_HW_INTERFACE_LINK_UP_DOWN_FUNCTION_PRIO(
    adj_nbr_hw_interface_state_change,
    VNET_ITF_FUNC_PRIORITY_HIGH);

static adj_walk_rc_t
adj_nbr_interface_delete_one (adj_index_t ai,
			      void *arg)
{
    /*
     * Back walk the graph to inform the forwarding entries
     * that this interface has been deleted.
     */
    fib_node_back_walk_ctx_t bw_ctx = {
	.fnbw_reason = FIB_NODE_BW_REASON_FLAG_INTERFACE_DELETE,
    };
    ip_adjacency_t *adj;

    adj = adj_get(ai);

    adj->ia_flags |= ADJ_FLAG_SYNC_WALK_ACTIVE;
    fib_walk_sync(FIB_NODE_TYPE_ADJ, ai, &bw_ctx);
    adj->ia_flags &= ~ADJ_FLAG_SYNC_WALK_ACTIVE;

    return (ADJ_WALK_RC_CONTINUE);
}

/**
 * adj_nbr_interface_add_del
 *
 * Registered to receive interface Add and delete notifications
 */
static clib_error_t *
adj_nbr_interface_add_del (vnet_main_t * vnm,
			   u32 sw_if_index,
			   u32 is_add)
{
    fib_protocol_t proto;

    if (is_add)
    {
	/*
	 * not interested in interface additions. we will not back walk
	 * to resolve paths through newly added interfaces. Why? The control
	 * plane should have the brains to add interfaces first, then routes.
	 * So the case where there are paths with a interface that matches
	 * one just created is the case where the path resolved through an
	 * interface that was deleted, and still has not been removed. The
	 * new interface added, is NO GUARANTEE that the interface being
	 * added now, even though it may have the same sw_if_index, is the
	 * same interface that the path needs. So tough!
	 * If the control plane wants these routes to resolve it needs to
	 * remove and add them again.
	 */
	return (NULL);
    }

    for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
    {
	adj_nbr_walk(sw_if_index, proto,
		     adj_nbr_interface_delete_one,
		     NULL);
    }

    return (NULL);
   
}

VNET_SW_INTERFACE_ADD_DEL_FUNCTION(adj_nbr_interface_add_del);


static adj_walk_rc_t
adj_nbr_show_one (adj_index_t ai,
		  void *arg)
{
    vlib_cli_output (arg, "[@%d]  %U",
                     ai,
                     format_ip_adjacency, ai,
		     FORMAT_IP_ADJACENCY_NONE);

    return (ADJ_WALK_RC_CONTINUE);
}

static clib_error_t *
adj_nbr_show (vlib_main_t * vm,
	      unformat_input_t * input,
	      vlib_cli_command_t * cmd)
{
    adj_index_t ai = ADJ_INDEX_INVALID;
    u32 sw_if_index = ~0;

    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
	if (unformat (input, "%d", &ai))
	    ;
	else if (unformat (input, "%U",
			   unformat_vnet_sw_interface, vnet_get_main(),
			   &sw_if_index))
	    ;
	else
	    break;
    }

    if (ADJ_INDEX_INVALID != ai)
    {
	vlib_cli_output (vm, "[@%d] %U",
                         ai,
                         format_ip_adjacency, ai,
			 FORMAT_IP_ADJACENCY_DETAIL);
    }
    else if (~0 != sw_if_index)
    {
	fib_protocol_t proto;

	for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
	{
	    adj_nbr_walk(sw_if_index, proto,
			 adj_nbr_show_one,
			 vm);
	}
    }
    else
    {
	fib_protocol_t proto;

	for (proto = FIB_PROTOCOL_IP4; proto <= FIB_PROTOCOL_IP6; proto++)
	{
	    vec_foreach_index(sw_if_index, adj_nbr_tables[proto])
	    {
		adj_nbr_walk(sw_if_index, proto,
			     adj_nbr_show_one,
			     vm);
	    }
	}
    }

    return 0;
}

/*?
 * Show all neighbour adjacencies.
 * @cliexpar
 * @cliexstart{sh adj nbr}
 * [@2] ipv4 via 1.0.0.2 loop0: IP4: 00:00:22:aa:bb:cc -> 00:00:11:aa:bb:cc
 * [@3] mpls via 1.0.0.2 loop0: MPLS_UNICAST: 00:00:22:aa:bb:cc -> 00:00:11:aa:bb:cc
 * [@4] ipv4 via 1.0.0.3 loop0: IP4: 00:00:22:aa:bb:cc -> 00:00:11:aa:bb:cc
 * [@5] mpls via 1.0.0.3 loop0: MPLS_UNICAST: 00:00:22:aa:bb:cc -> 00:00:11:aa:bb:cc
 * @cliexend
 ?*/
VLIB_CLI_COMMAND (ip4_show_fib_command, static) = {
    .path = "show adj nbr",
    .short_help = "show adj nbr [<adj_index>] [interface]",
    .function = adj_nbr_show,
};

u8*
format_adj_nbr_incomplete (u8* s, va_list *ap)
{
    index_t index = va_arg(*ap, index_t);
    CLIB_UNUSED(u32 indent) = va_arg(*ap, u32);
    vnet_main_t * vnm = vnet_get_main();
    ip_adjacency_t * adj = adj_get(index);

    s = format (s, "arp-%U", format_vnet_link, adj->ia_link);
    s = format (s, ": via %U",
                format_ip46_address, &adj->sub_type.nbr.next_hop,
		adj_proto_to_46(adj->ia_nh_proto));
    s = format (s, " %U",
                format_vnet_sw_if_index_name,
                vnm, adj->rewrite_header.sw_if_index);

    return (s);
}

u8*
format_adj_nbr (u8* s, va_list *ap)
{
    index_t index = va_arg(*ap, index_t);
    CLIB_UNUSED(u32 indent) = va_arg(*ap, u32);
    ip_adjacency_t * adj = adj_get(index);

    s = format (s, "%U", format_vnet_link, adj->ia_link);
    s = format (s, " via %U ",
		format_ip46_address, &adj->sub_type.nbr.next_hop,
		adj_proto_to_46(adj->ia_nh_proto));
    s = format (s, "%U",
		format_vnet_rewrite,
		&adj->rewrite_header, sizeof (adj->rewrite_data), 0);

    return (s);
}

static void
adj_dpo_lock (dpo_id_t *dpo)
{
    adj_lock(dpo->dpoi_index);
}
static void
adj_dpo_unlock (dpo_id_t *dpo)
{
    adj_unlock(dpo->dpoi_index);
}

static void
adj_mem_show (void)
{
    fib_show_memory_usage("Adjacency",
			  pool_elts(adj_pool),
			  pool_len(adj_pool),
			  sizeof(ip_adjacency_t));
}

const static dpo_vft_t adj_nbr_dpo_vft = {
    .dv_lock = adj_dpo_lock,
    .dv_unlock = adj_dpo_unlock,
    .dv_format = format_adj_nbr,
    .dv_mem_show = adj_mem_show,
    .dv_get_urpf = adj_dpo_get_urpf,
};
const static dpo_vft_t adj_nbr_incompl_dpo_vft = {
    .dv_lock = adj_dpo_lock,
    .dv_unlock = adj_dpo_unlock,
    .dv_format = format_adj_nbr_incomplete,
    .dv_get_urpf = adj_dpo_get_urpf,
};

/**
 * @brief The per-protocol VLIB graph nodes that are assigned to an adjacency
 *        object.
 *
 * this means that these graph nodes are ones from which a nbr is the
 * parent object in the DPO-graph.
 */
const static char* const nbr_ip4_nodes[] =
{
    "ip4-rewrite",
    NULL,
};
const static char* const nbr_ip6_nodes[] =
{
    "ip6-rewrite",
    NULL,
};
const static char* const nbr_mpls_nodes[] =
{
    "mpls-output",
    NULL,
};
const static char* const nbr_ethernet_nodes[] =
{
    "adj-l2-rewrite",
    NULL,
};
const static char* const * const nbr_nodes[DPO_PROTO_NUM] =
{
    [DPO_PROTO_IP4]  = nbr_ip4_nodes,
    [DPO_PROTO_IP6]  = nbr_ip6_nodes,
    [DPO_PROTO_MPLS] = nbr_mpls_nodes,
    [DPO_PROTO_ETHERNET] = nbr_ethernet_nodes,
};

const static char* const nbr_incomplete_ip4_nodes[] =
{
    "ip4-arp",
    NULL,
};
const static char* const nbr_incomplete_ip6_nodes[] =
{
    "ip6-discover-neighbor",
    NULL,
};
const static char* const nbr_incomplete_mpls_nodes[] =
{
    "mpls-adj-incomplete",
    NULL,
};

const static char* const * const nbr_incomplete_nodes[DPO_PROTO_NUM] =
{
    [DPO_PROTO_IP4]  = nbr_incomplete_ip4_nodes,
    [DPO_PROTO_IP6]  = nbr_incomplete_ip6_nodes,
    [DPO_PROTO_MPLS] = nbr_incomplete_mpls_nodes,
};

void
adj_nbr_module_init (void)
{
    dpo_register(DPO_ADJACENCY,
                 &adj_nbr_dpo_vft,
                 nbr_nodes);
    dpo_register(DPO_ADJACENCY_INCOMPLETE,
                 &adj_nbr_incompl_dpo_vft,
                 nbr_incomplete_nodes);
}