[8717] | 1 | #!/usr/bin/perl |
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| 2 | # |
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| 3 | # Perform sanity checks on the services file, supplied as argument. |
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| 4 | # Based on an earlier shell script of the same name, but much faster, |
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| 5 | # and it also detects actual errors in the current services file :) |
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| 6 | # |
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| 7 | # This program includes a manual, run "perldoc serviceslint" to see it. |
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| 8 | # |
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| 9 | |
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| 10 | use strict; |
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| 11 | use warnings; |
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| 12 | |
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| 13 | die "Usage: $0 /etc/services\n" unless $#ARGV == 0; |
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| 14 | |
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| 15 | # Build a hash of known protocols |
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| 16 | my %protocol; |
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| 17 | open FH, "protocols" or die "cannot open protocols: $!\n"; |
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| 18 | while (<FH>) { |
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| 19 | chomp; |
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| 20 | s/#.*$//; |
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| 21 | my ($name, $port) = m/([\S]+)\s+(\d+)/ or next; |
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| 22 | $protocol{$name} = $port; |
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| 23 | } |
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| 24 | close FH; |
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| 25 | |
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| 26 | # Parse the supplied services file |
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| 27 | my $retval = 0; |
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| 28 | my $line = 0; |
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| 29 | my %service; |
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| 30 | open FH, $ARGV[0] or die "cannot open $ARGV[0]: $!\n"; |
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| 31 | while (<FH>) { |
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| 32 | $line++; # Keep a line count |
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| 33 | chomp; # Remove CR/LF chars |
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| 34 | if (m/^\s+/) { |
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| 35 | print "Malformed line $line\n"; # No leading whitespace |
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| 36 | $retval = 1; |
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| 37 | next; |
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| 38 | } |
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| 39 | s/\s*#.*$//; # Strip out comments |
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| 40 | next if m/^$/; # Skip empty lines |
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| 41 | my ($name, $port, $proto, $aliases) = # Primary pattern match |
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| 42 | m/^([\S]+)\s+(\d+)\/(\w+)\s*(.*)/ |
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| 43 | or die "Malformed line: $line\n"; |
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| 44 | if (not exists $protocol{$proto}) { |
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| 45 | print "Bad protocol at line $line: $proto\n"; |
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| 46 | $retval = 1; |
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| 47 | } |
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| 48 | if (exists $service{$proto}{$port}) { |
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| 49 | print "Duplicate port at line $line: $port/$proto\n"; |
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| 50 | $retval = 1; |
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| 51 | } |
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| 52 | $service{$proto}{$port} = $name; |
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| 53 | foreach ($name, split /\s+/, $aliases) { |
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| 54 | if (exists $service{$proto}{$_}) { |
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| 55 | print "Duplicate name at line $line: $_/$proto\n"; |
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| 56 | $retval = 1; |
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| 57 | } |
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| 58 | $service{$proto}{$_} = $port; |
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| 59 | }; |
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| 60 | |
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| 61 | } |
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| 62 | close FH; |
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| 63 | exit $retval; |
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| 64 | |
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| 65 | __END__ |
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| 66 | |
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| 67 | =head1 NAME |
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| 68 | |
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| 69 | serviceslint - perform verification on the /etc/services file |
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| 70 | |
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| 71 | =head1 SYNOPSIS |
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| 72 | |
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| 73 | B<serviceslint> I<filename> |
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| 74 | |
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| 75 | =head1 DESCRIPTION |
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| 76 | |
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| 77 | The B<serviceslint> command performs syntax and content checks on the |
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| 78 | given filename, normally a copy of the I</etc/services> file. |
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| 79 | |
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| 80 | Syntax checking consists of a regular expression applied to |
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| 81 | non-empty, non-comment lines. If the syntax check fails, then |
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| 82 | the program prints a message and aborts with non-zero status code. |
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| 83 | |
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| 84 | Content checking detects various kinds of duplicate entries. |
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| 85 | Currently, warnings are printed for duplicate entries, but execution |
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| 86 | continues, and the program I<exits with status code zero> (eg. success). |
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| 87 | |
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| 88 | =over |
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| 89 | |
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| 90 | =item B<Malformed line> I<NNN> |
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| 91 | |
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| 92 | The specified line has invalid syntax. Note that leading whitespace |
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| 93 | is not permitted. Non-empty lines must begin with a comment, or with |
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| 94 | a service name followed by a port number / protocol pair. |
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| 95 | |
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| 96 | =item B<Duplicate port at line> I<NNN> |
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| 97 | |
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| 98 | Occurs when a port number / protocol pair is found more than once |
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| 99 | in the services file. The warning is flagged on the second (and any |
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| 100 | subsequent) occurrences. These entries will not be found via the |
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| 101 | B<getservbyport()> function. |
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| 102 | |
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| 103 | =item B<Duplicate name at line> I<NNN> |
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| 104 | |
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| 105 | Occurs when a service name, or alias, occurs more than once in the |
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| 106 | services file. The warning is flagged on the second (and subsequent) |
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| 107 | occurrence. These entries will not be returned by the B<getservbyname()> |
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| 108 | function. |
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| 109 | |
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| 110 | =back |
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| 111 | |
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| 112 | =head1 SEE ALSO |
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| 113 | |
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| 114 | The services(5) man page describes the file format. |
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| 115 | |
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| 116 | =head1 AUTHOR |
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| 117 | |
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| 118 | Ralph Siemsen & Phil Knirsch |
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| 119 | |
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