2 # SPDX-License-Identifier: GPL-2.0-or-later
4 # Build a static ASN.1 Object Identified (OID) registry
6 # Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
7 # Written by David Howells (dhowells@redhat.com)
17 print STDERR "Format: ", $0, " <in-h-file> <out-c-file>\n";
21 my $abs_srctree = abs_path($ENV{'srctree'});
24 # Open the file to read from
26 open IN_FILE, "<$ARGV[0]" || die;
29 if (m!\s+OID_([a-zA-z][a-zA-Z0-9_]+),\s+/[*]\s+([012][.0-9]*)\s+[*]/!) {
37 # Open the files to write into
39 open C_FILE, ">$ARGV[1]" or die;
41 print C_FILE " * Automatically generated by ", $0 =~ s#^\Q$abs_srctree/\E##r, ". Do not edit\n";
45 # Split the data up into separate lists and also determine the lengths of the
46 # encoded data arrays.
52 for (my $i = 0; $i <= $#names; $i++) {
53 my $name = $names[$i];
56 my @components = split(/[.]/, $oid);
58 # Determine the encoded length of this OID
59 my $size = $#components;
60 for (my $loop = 2; $loop <= $#components; $loop++) {
61 my $c = $components[$loop];
63 # We will base128 encode the number
64 my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
69 push @indices, $total_length;
70 $total_length += $size;
74 # Emit the look-up-by-OID index table
77 if ($total_length <= 255) {
78 print C_FILE "static const unsigned char oid_index[OID__NR + 1] = {\n";
80 print C_FILE "static const unsigned short oid_index[OID__NR + 1] = {\n";
82 for (my $i = 0; $i <= $#names; $i++) {
83 print C_FILE "\t[OID_", $names[$i], "] = ", $indices[$i], ",\n"
85 print C_FILE "\t[OID__NR] = ", $total_length, "\n";
91 my @encoded_oids = ();
93 for (my $i = 0; $i <= $#names; $i++) {
96 my @components = split(/[.]/, $oids[$i]);
98 push @octets, $components[0] * 40 + $components[1];
100 for (my $loop = 2; $loop <= $#components; $loop++) {
101 my $c = $components[$loop];
103 # Base128 encode the number
104 my $tmp = ($c == 0) ? 0 : int(log($c)/log(2));
105 $tmp = int($tmp / 7);
107 for (; $tmp > 0; $tmp--) {
108 push @octets, (($c >> $tmp * 7) & 0x7f) | 0x80;
110 push @octets, $c & 0x7f;
113 push @encoded_oids, \@octets;
117 # Create a hash value for each OID
119 my @hash_values = ();
120 for (my $i = 0; $i <= $#names; $i++) {
121 my @octets = @{$encoded_oids[$i]};
128 $hash = ($hash >> 24) ^ ($hash >> 16) ^ ($hash >> 8) ^ ($hash);
130 push @hash_values, $hash & 0xff;
137 print C_FILE "static const unsigned char oid_data[", $total_length, "] = {\n";
138 for (my $i = 0; $i <= $#names; $i++) {
139 my @octets = @{$encoded_oids[$i]};
141 print C_FILE $_, ", " foreach (@octets);
142 print C_FILE "\t// ", $names[$i];
148 # Build the search index table (ordered by length then hash then content)
150 my @index_table = ( 0 .. $#names );
152 @index_table = sort {
153 my @octets_a = @{$encoded_oids[$a]};
154 my @octets_b = @{$encoded_oids[$b]};
156 return $hash_values[$a] <=> $hash_values[$b]
157 if ($hash_values[$a] != $hash_values[$b]);
158 return $#octets_a <=> $#octets_b
159 if ($#octets_a != $#octets_b);
160 for (my $i = $#octets_a; $i >= 0; $i--) {
161 return $octets_a[$i] <=> $octets_b[$i]
162 if ($octets_a[$i] != $octets_b[$i]);
169 # Emit the search index and hash value table
172 print C_FILE "static const struct {\n";
173 print C_FILE "\tunsigned char hash;\n";
174 if ($#names <= 255) {
175 print C_FILE "\tenum OID oid : 8;\n";
177 print C_FILE "\tenum OID oid : 16;\n";
179 print C_FILE "} oid_search_table[OID__NR] = {\n";
180 for (my $i = 0; $i <= $#names; $i++) {
181 my @octets = @{$encoded_oids[$index_table[$i]]};
182 printf(C_FILE "\t[%3u] = { %3u, OID_%-35s }, // ",
184 $hash_values[$index_table[$i]],
185 $names[$index_table[$i]]);
186 printf C_FILE "%02x", $_ foreach (@octets);
192 # Emit the OID debugging name table
195 #print C_FILE "const char *const oid_name_table[OID__NR + 1] = {\n";
197 #for (my $i = 0; $i <= $#names; $i++) {
198 # print C_FILE "\t\"", $names[$i], "\",\n"
200 #print C_FILE "\t\"Unknown-OID\"\n";
201 #print C_FILE "};\n";