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David Howellsa77ad6e2012-09-21 23:30:46 +01001#!/usr/bin/perl -w
Thomas Gleixnerb4d0d232019-05-20 19:08:01 +02002# SPDX-License-Identifier: GPL-2.0-or-later
David Howellsa77ad6e2012-09-21 23:30:46 +01003#
4# Build a static ASN.1 Object Identified (OID) registry
5#
6# Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
7# Written by David Howells (dhowells@redhat.com)
8#
David Howellsa77ad6e2012-09-21 23:30:46 +01009
10use strict;
11
12my @names = ();
13my @oids = ();
14
15if ($#ARGV != 1) {
16 print STDERR "Format: ", $0, " <in-h-file> <out-c-file>\n";
17 exit(2);
18}
19
20#
21# Open the file to read from
22#
23open IN_FILE, "<$ARGV[0]" || die;
24while (<IN_FILE>) {
25 chomp;
26 if (m!\s+OID_([a-zA-z][a-zA-Z0-9_]+),\s+/[*]\s+([012][.0-9]*)\s+[*]/!) {
27 push @names, $1;
28 push @oids, $2;
29 }
30}
31close IN_FILE || die;
32
33#
34# Open the files to write into
35#
36open C_FILE, ">$ARGV[1]" or die;
37print C_FILE "/*\n";
38print C_FILE " * Automatically generated by ", $0, ". Do not edit\n";
39print C_FILE " */\n";
40
41#
42# Split the data up into separate lists and also determine the lengths of the
43# encoded data arrays.
44#
45my @indices = ();
46my @lengths = ();
47my $total_length = 0;
48
David Howellsa77ad6e2012-09-21 23:30:46 +010049for (my $i = 0; $i <= $#names; $i++) {
50 my $name = $names[$i];
51 my $oid = $oids[$i];
52
53 my @components = split(/[.]/, $oid);
54
55 # Determine the encoded length of this OID
56 my $size = $#components;
57 for (my $loop = 2; $loop <= $#components; $loop++) {
58 my $c = $components[$loop];
59
60 # We will base128 encode the number
61 my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
62 $tmp = int($tmp / 7);
63 $size += $tmp;
64 }
65 push @lengths, $size;
66 push @indices, $total_length;
67 $total_length += $size;
68}
69
70#
71# Emit the look-up-by-OID index table
72#
73print C_FILE "\n";
74if ($total_length <= 255) {
75 print C_FILE "static const unsigned char oid_index[OID__NR + 1] = {\n";
76} else {
77 print C_FILE "static const unsigned short oid_index[OID__NR + 1] = {\n";
78}
79for (my $i = 0; $i <= $#names; $i++) {
80 print C_FILE "\t[OID_", $names[$i], "] = ", $indices[$i], ",\n"
81}
82print C_FILE "\t[OID__NR] = ", $total_length, "\n";
83print C_FILE "};\n";
84
85#
86# Encode the OIDs
87#
88my @encoded_oids = ();
89
90for (my $i = 0; $i <= $#names; $i++) {
91 my @octets = ();
92
93 my @components = split(/[.]/, $oids[$i]);
94
95 push @octets, $components[0] * 40 + $components[1];
96
97 for (my $loop = 2; $loop <= $#components; $loop++) {
98 my $c = $components[$loop];
99
100 # Base128 encode the number
101 my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
102 $tmp = int($tmp / 7);
103
104 for (; $tmp > 0; $tmp--) {
105 push @octets, (($c >> $tmp * 7) & 0x7f) | 0x80;
106 }
107 push @octets, $c & 0x7f;
108 }
109
110 push @encoded_oids, \@octets;
111}
112
113#
114# Create a hash value for each OID
115#
116my @hash_values = ();
117for (my $i = 0; $i <= $#names; $i++) {
118 my @octets = @{$encoded_oids[$i]};
119
120 my $hash = $#octets;
121 foreach (@octets) {
122 $hash += $_ * 33;
123 }
124
125 $hash = ($hash >> 24) ^ ($hash >> 16) ^ ($hash >> 8) ^ ($hash);
126
127 push @hash_values, $hash & 0xff;
128}
129
130#
131# Emit the OID data
132#
133print C_FILE "\n";
134print C_FILE "static const unsigned char oid_data[", $total_length, "] = {\n";
135for (my $i = 0; $i <= $#names; $i++) {
136 my @octets = @{$encoded_oids[$i]};
137 print C_FILE "\t";
138 print C_FILE $_, ", " foreach (@octets);
139 print C_FILE "\t// ", $names[$i];
140 print C_FILE "\n";
141}
142print C_FILE "};\n";
143
144#
145# Build the search index table (ordered by length then hash then content)
146#
147my @index_table = ( 0 .. $#names );
148
149@index_table = sort {
150 my @octets_a = @{$encoded_oids[$a]};
151 my @octets_b = @{$encoded_oids[$b]};
152
153 return $hash_values[$a] <=> $hash_values[$b]
154 if ($hash_values[$a] != $hash_values[$b]);
155 return $#octets_a <=> $#octets_b
156 if ($#octets_a != $#octets_b);
157 for (my $i = $#octets_a; $i >= 0; $i--) {
158 return $octets_a[$i] <=> $octets_b[$i]
159 if ($octets_a[$i] != $octets_b[$i]);
160 }
161 return 0;
162
163} @index_table;
164
165#
166# Emit the search index and hash value table
167#
168print C_FILE "\n";
169print C_FILE "static const struct {\n";
170print C_FILE "\tunsigned char hash;\n";
171if ($#names <= 255) {
172 print C_FILE "\tenum OID oid : 8;\n";
173} else {
174 print C_FILE "\tenum OID oid : 16;\n";
175}
176print C_FILE "} oid_search_table[OID__NR] = {\n";
177for (my $i = 0; $i <= $#names; $i++) {
178 my @octets = @{$encoded_oids[$index_table[$i]]};
179 printf(C_FILE "\t[%3u] = { %3u, OID_%-35s }, // ",
180 $i,
181 $hash_values[$index_table[$i]],
182 $names[$index_table[$i]]);
183 printf C_FILE "%02x", $_ foreach (@octets);
184 print C_FILE "\n";
185}
186print C_FILE "};\n";
187
188#
189# Emit the OID debugging name table
190#
191#print C_FILE "\n";
192#print C_FILE "const char *const oid_name_table[OID__NR + 1] = {\n";
193#
194#for (my $i = 0; $i <= $#names; $i++) {
195# print C_FILE "\t\"", $names[$i], "\",\n"
196#}
197#print C_FILE "\t\"Unknown-OID\"\n";
198#print C_FILE "};\n";
199
200#
201# Polish off
202#
203close C_FILE or die;