diff options
Diffstat (limited to 'kernel/lib/build_OID_registry')
| -rwxr-xr-x | kernel/lib/build_OID_registry | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/kernel/lib/build_OID_registry b/kernel/lib/build_OID_registry new file mode 100755 index 000000000..5d9827217 --- /dev/null +++ b/kernel/lib/build_OID_registry @@ -0,0 +1,207 @@ +#!/usr/bin/perl -w +# +# Build a static ASN.1 Object Identified (OID) registry +# +# Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. +# Written by David Howells (dhowells@redhat.com) +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public Licence +# as published by the Free Software Foundation; either version +# 2 of the Licence, or (at your option) any later version. +# + +use strict; + +my @names = (); +my @oids = (); + +if ($#ARGV != 1) { + print STDERR "Format: ", $0, " <in-h-file> <out-c-file>\n"; + exit(2); +} + +# +# Open the file to read from +# +open IN_FILE, "<$ARGV[0]" || die; +while (<IN_FILE>) { + chomp; + if (m!\s+OID_([a-zA-z][a-zA-Z0-9_]+),\s+/[*]\s+([012][.0-9]*)\s+[*]/!) { + push @names, $1; + push @oids, $2; + } +} +close IN_FILE || die; + +# +# Open the files to write into +# +open C_FILE, ">$ARGV[1]" or die; +print C_FILE "/*\n"; +print C_FILE " * Automatically generated by ", $0, ". Do not edit\n"; +print C_FILE " */\n"; + +# +# Split the data up into separate lists and also determine the lengths of the +# encoded data arrays. +# +my @indices = (); +my @lengths = (); +my $total_length = 0; + +for (my $i = 0; $i <= $#names; $i++) { + my $name = $names[$i]; + my $oid = $oids[$i]; + + my @components = split(/[.]/, $oid); + + # Determine the encoded length of this OID + my $size = $#components; + for (my $loop = 2; $loop <= $#components; $loop++) { + my $c = $components[$loop]; + + # We will base128 encode the number + my $tmp = ($c == 0) ? 0 : int(log($c)/log(2)); + $tmp = int($tmp / 7); + $size += $tmp; + } + push @lengths, $size; + push @indices, $total_length; + $total_length += $size; +} + +# +# Emit the look-up-by-OID index table +# +print C_FILE "\n"; +if ($total_length <= 255) { + print C_FILE "static const unsigned char oid_index[OID__NR + 1] = {\n"; +} else { + print C_FILE "static const unsigned short oid_index[OID__NR + 1] = {\n"; +} +for (my $i = 0; $i <= $#names; $i++) { + print C_FILE "\t[OID_", $names[$i], "] = ", $indices[$i], ",\n" +} +print C_FILE "\t[OID__NR] = ", $total_length, "\n"; +print C_FILE "};\n"; + +# +# Encode the OIDs +# +my @encoded_oids = (); + +for (my $i = 0; $i <= $#names; $i++) { + my @octets = (); + + my @components = split(/[.]/, $oids[$i]); + + push @octets, $components[0] * 40 + $components[1]; + + for (my $loop = 2; $loop <= $#components; $loop++) { + my $c = $components[$loop]; + + # Base128 encode the number + my $tmp = ($c == 0) ? 0 : int(log($c)/log(2)); + $tmp = int($tmp / 7); + + for (; $tmp > 0; $tmp--) { + push @octets, (($c >> $tmp * 7) & 0x7f) | 0x80; + } + push @octets, $c & 0x7f; + } + + push @encoded_oids, \@octets; +} + +# +# Create a hash value for each OID +# +my @hash_values = (); +for (my $i = 0; $i <= $#names; $i++) { + my @octets = @{$encoded_oids[$i]}; + + my $hash = $#octets; + foreach (@octets) { + $hash += $_ * 33; + } + + $hash = ($hash >> 24) ^ ($hash >> 16) ^ ($hash >> 8) ^ ($hash); + + push @hash_values, $hash & 0xff; +} + +# +# Emit the OID data +# +print C_FILE "\n"; +print C_FILE "static const unsigned char oid_data[", $total_length, "] = {\n"; +for (my $i = 0; $i <= $#names; $i++) { + my @octets = @{$encoded_oids[$i]}; + print C_FILE "\t"; + print C_FILE $_, ", " foreach (@octets); + print C_FILE "\t// ", $names[$i]; + print C_FILE "\n"; +} +print C_FILE "};\n"; + +# +# Build the search index table (ordered by length then hash then content) +# +my @index_table = ( 0 .. $#names ); + +@index_table = sort { + my @octets_a = @{$encoded_oids[$a]}; + my @octets_b = @{$encoded_oids[$b]}; + + return $hash_values[$a] <=> $hash_values[$b] + if ($hash_values[$a] != $hash_values[$b]); + return $#octets_a <=> $#octets_b + if ($#octets_a != $#octets_b); + for (my $i = $#octets_a; $i >= 0; $i--) { + return $octets_a[$i] <=> $octets_b[$i] + if ($octets_a[$i] != $octets_b[$i]); + } + return 0; + +} @index_table; + +# +# Emit the search index and hash value table +# +print C_FILE "\n"; +print C_FILE "static const struct {\n"; +print C_FILE "\tunsigned char hash;\n"; +if ($#names <= 255) { + print C_FILE "\tenum OID oid : 8;\n"; +} else { + print C_FILE "\tenum OID oid : 16;\n"; +} +print C_FILE "} oid_search_table[OID__NR] = {\n"; +for (my $i = 0; $i <= $#names; $i++) { + my @octets = @{$encoded_oids[$index_table[$i]]}; + printf(C_FILE "\t[%3u] = { %3u, OID_%-35s }, // ", + $i, + $hash_values[$index_table[$i]], + $names[$index_table[$i]]); + printf C_FILE "%02x", $_ foreach (@octets); + print C_FILE "\n"; +} +print C_FILE "};\n"; + +# +# Emit the OID debugging name table +# +#print C_FILE "\n"; +#print C_FILE "const char *const oid_name_table[OID__NR + 1] = {\n"; +# +#for (my $i = 0; $i <= $#names; $i++) { +# print C_FILE "\t\"", $names[$i], "\",\n" +#} +#print C_FILE "\t\"Unknown-OID\"\n"; +#print C_FILE "};\n"; + +# +# Polish off +# +close C_FILE or die; |