examples/crfc2asn1.pl

   1 #!/usr/bin/env perl
   2 #
   3 # Extract the ASN.1 module text from the given set of RFC files.
   4 #
   5
   6
   7 my $inasn = 0;  # Are we inside ASN.1 grammar?
   8 my $found = 0;
   9 my $currentFname = '';
  10
  11 if(-t STDIN && $#ARGV == -1) {
  12         print STDERR "Extract the ASN.1 specification from the RFC file(s).\n";
  13         print STDERR "Usage 1: $0 <rfc-file.txt> ...\n";
  14         print STDERR "Usage 2: <someprog> | $0\n";
  15         exit(1);
  16 }
  17
  18 while(<>) {
  19         #
  20         # Strip RFC page delimiters.
  21         #
  22         next if /^[A-Z].*\[Page [0-9]+\]$/;
  23         next if /^\f$/;
  24         next if /^RFC [0-9].*[0-9]+$/;
  25
  26         if($inasn == 0) {
  27                 #
  28                 # The least correct way to find the start of ASN
  29                 # definition. That is, to ask a user.
  30                 #
  31                 if(/^[ \t]*END[ \t]*(--.*)?$/) {
  32                         print STDERR
  33                         "Missed an ASN.1 grammar before line ". $. ."?\n";
  34                         exit(1);
  35                 }
  36
  37                 my $modName = '';       # ASN.1 module name
  38                 my $rfcid = '';
  39                 $rfcid = $1 . '-' if($ARGV =~ /([a-z0-9]+)\.[^.]+$/i);
  40
  41                 if(/^[ \t]*([A-Z][A-Za-z0-9-]*).*DEFINITIONS.*::=/) {
  42                         $modName = $1;
  43                         $currentFname = $rfcid . $modName . ".asn1";
  44                         $inasn = 1;
  45                 } elsif(/^[ \t]*([A-Z][A-Za-z0-9-]*).*{[ \t]*(?:joint-)?iso/
  46                 || /^[ \t]*{[ \t]*(?:joint-)?iso/) {
  47                         my @a = ($_);
  48                         $modName = $1;
  49                         unless(length($modName)) {
  50                                 next unless $prevLine =~
  51                                         /^[ \t]*([A-Z][A-Za-z0-9-]*)[ \t]*$/;
  52                                 $modName = $1;
  53                                 unshift(@a, $prevLine);
  54                         }
  55                         $currentFname = $rfcid . $modName . ".asn1";
  56                         my $i;
  57                         for($i = 0; $i < 8; $i++) {
  58                                 $_ = <>;
  59                                 push(@a, $_);
  60                                 if(/DEFINITIONS/) {
  61                                         $_ = join('', @a);
  62                                         $inasn = 1;
  63                                         last;
  64                                 }
  65                         }
  66                         next unless $inasn;
  67                 } elsif(/^\s*DEFINITIONS\s*$/
  68                 && $prevLine =~ /^\s*([A-Z][A-Za-z0-9-]*)\s*{[0-9a-z)( -]+}\s*$/) {
  69                         $_ = $prevLine . $prevComments . $_;
  70                         $modName = $1;
  71                         $currentFname = $rfcid . $modName. ".asn1";
  72                         $inasn = 1;
  73                 } else {
  74                         if(/^[ \t]*--/) {
  75                                 $prevComments .= $_;
  76                         } else {
  77                                 $prevComments = '';
  78                                 $prevLine = $_;
  79                         }
  80                         next;
  81                 }
  82
  83                 print STDERR "Found $modName at line $.\n=> Saving as $currentFname\n";
  84                 open(O, "> $currentFname") or die "Can't open $currentFname";
  85                 select(O);
  86
  87                 $found++;
  88                 print "\n";
  89                 print "-- \n";
  90                 print "-- ASN.1 module found by $0 in $ARGV at line " . $. . "\n";
  91                 print "-- \n";
  92                 print "\n";
  93         }
  94
  95         if(/^[ \t]*END[ \t]*(--.*)?$/) {
  96                 print;
  97                 select(STDOUT);
  98                 close(O);
  99                 $inasn = 0;
 100                 next;
 101         }
 102
 103         #
 104         # The following clauses are primarily designed to simplify
 105         # asn1c tool behavior.
 106         # You may want to get rid of them if you're doing generic
 107         # ASN.1 extraction and do not want to alter the ASN.1 specs at all.
 108         #
 109         if(
 110 /^([ \t]*)((UniversalString|BMPString|UTF8String)\s+::=\s+\[[A-Z]+\s\d+\]\sIMPLICIT\sOCTET\sSTRING)(.*)$/ms
 111         ) {
 112                 print "\n-- Legacy redefinition of $3 removed by $0:\n";
 113                 print "$1-- $2 -- $4";
 114                 next;
 115         } elsif(/delete following line if \"new\" types are supported/) {
 116                 print;
 117                 print "/* Legacy constructs deleted by $0:\n";
 118                 $_ = <>;
 119                 print;
 120                 print " */\n";
 121                 next;
 122         }
 123
 124
 125         print;  # Dump the ASN.1 module line out.
 126 }
 127
 128 die "No ASN.1 modules found\n" unless $found;