1 files changed, 557 insertions, 187 deletions

diff --git a/vhostcname/vhostcname b/vhostcname/vhostcname
index 359101c..fc6dd2d 100755
--- a/vhostcname/vhostcname
+++ b/vhostcname/vhostcname
@@ -1,3 +1,3 @@
 #!/usr/bin/perl
-# Copyright (C) 2014 Sergey Poznyakoff <gray@gnu.org>
+# Copyright (C) 2014-2016 Sergey Poznyakoff <gray@gnu.org>
 #
@@ -24,26 +24,31 @@ use Net::DNS;
 
-my $script;        # This script name;
-
+my $progname;        # This script name;
+my $progdescr = "update DNS from Apache virtual host configuration";
 my $config_file = "/etc/vhostcname.conf";
+my %config = (
+    core => {
+        'cache' => "/var/run/vhostcname.cache",
+# Default TTL.
+        'ttl' => 3600,
+# A globbing pattern for Apache configuration files.
+        'apache-config-pattern' => "*",
+    }
+);
+
+use constant EX_OK => 0;
+use constant EX_NOTUPDATED => 1;
+use constant EX_USAGE => 64;
+use constant EX_NOINPUT => 66;
+use constant EX_CANTCREAT => 73;
+use constant EX_CONFIG => 78;
 
-my $cnamelist = "/var/run/vhostcname.cache";
 my $host;          # This host name.
-my @zone;          # List of acceptable DNS zones.
 my $nameserver;    # Nameserver to use for updates.
-my @tsig_args;     # Arguments to sing_tsig (path to the DNSSEC key file, or
-                   # the key name and hash.
-my $ttl = 3600;    # Default TTL.
-my $confdir;       # Apache configuration directory.
-my $confpat = "*"; # A globbing pattern for Apache configuration files.
 my $dry_run;       # Dry-run mode.
 my $debug;         # Debug level.
-my $allow_wildcard_domains;
-
-my $help;          # Display help summary.
-my $man;           # Ditto in manpage format.
 
-my $status = 0;    # Default exit status.
+my $status = EX_OK;# Default exit status.
 
 sub err {
-    print STDERR "$script: ";
+    print STDERR "$progname: ";
     print STDERR $_ for (@_);
@@ -58,21 +63,189 @@ sub abend {
 
-sub read_config_file($) {
-    my $file = shift;
-    unless (-f $file) {
-        print STDERR "$script: configuration file $file does not exist\n"
-            if ($debug);
-        return;
+sub parse_section {
+    my ($conf, $input) = @_;
+    my $ref = $conf;
+    my $quote;
+    my $rootname;
+    while ($input ne '') {
+        my $name;
+        if (!defined($quote)) {
+            if ($input =~ /^"(.*)/) {
+                $quote = '';
+                $input = $1;
+            } elsif ($input =~ /^(.+?)(?:\s+|")(.*)/) {
+                $name = $1;
+                $input = $2;
+            } else {
+                $name = $input;
+                $input = '';
+            }
+        } else {
+            if ($input =~ /^([^\\"]*)\\(.)(.*)/) {
+                $quote .= $1 . $2;
+                $input = $3;
+            } elsif ($input =~ /^([^\\"]*)"\s*(.*)/) {
+                $name = $quote . $1;
+                $input = $2;
+                $quote = undef;
+            } else {
+                die "unparsable input $input";
+            }
+        }
+
+        if (defined($name)) {
+            $rootname = $name unless defined $rootname;
+            $ref->{$name} = {} unless ref($ref->{$name}) eq 'HASH';
+            $ref = $ref->{$name};
+            $name = undef;
     }
-    print STDERR "$script: reading $file\n" if ($debug);
-    open(my $fd, "<", $file) or abend(1, "cannot open $file: $!");
+    }
+    return ($ref, $rootname);
+}
+
+sub check_mandatory {
+    my ($section, $kw, $loc, $s) = @_;
+    my $err = 0;
+    while (my ($k, $d) = each %{$kw}) {
+        if (ref($d) eq 'HASH'
+            and $d->{mandatory}
+            and !exists($section->{$k})) {
+            if (exists($d->{section})) {
+                if ($s) {
+                    err("$loc: mandatory section [$k] not present");
+                    ++$err;
+                }
+            } else {
+                err("$loc: mandatory variable \"$k\" not set");
+                ++$err;
+            }
+        }
+    }
+    return $err;
+}
+
+sub readconfig {
+    my $file = shift;
+    my $conf = shift;
+    my %param = @_;
+
+#    debug(2, "reading $file");
+    open(my $fd, "<", $file)
+        or do {
+            err("can't open configuration file $file: $!");
+            return 1 if $param{include};
+            exit(EX_NOINPUT);
+    };
+    
+    my $line;
+    my $err;
+    my $section = $conf;
+    my $kw = $param{kw};
+    my $include = 0;
+    my $rootname;
+    
     while (<$fd>) {
+        ++$line;
         chomp;
+        if (/\\$/) {
+            chop;
+            $_ .= <$fd>;
+            redo;
+        }
+        
         s/^\s+//;
         s/\s+$//;
-        s/\s+=\s+/=/;
         s/#.*//;
         next if ($_ eq "");
-        unshift(@ARGV, "--$_");
+
+        if (/^\[(.+?)\]$/) {
+            $include = 0;
+            my $arg = $1;
+            $arg =~ s/^\s+//;
+            $arg =~ s/\s+$//;
+            if ($arg eq 'include') {
+                $include = 1;
+            } else {
+                ($section, $rootname) = parse_section($conf, $1);
+                if (ref($param{kw}) eq 'HASH') {
+                    if (defined($rootname)) {
+                        if (ref($param{kw}{$rootname}) eq 'HASH'
+                            and exists($param{kw}{$rootname}{section})) {
+                            $kw = $param{kw}{$rootname}{section};
+                        } else {
+                            err("$file:$line: unknown section");
+                            $kw = undef;
+                        }
+                    } else {
+                        $kw = $param{kw};
+                    }
     }
-    close($fd);
+            }
+        } elsif (/([\w_-]+)\s*=\s*(.*)/) {
+            my ($k, $v) = ($1, $2);
+            $k = lc($k) if $param{ci};
+
+            if ($include) {
+                if ($k eq 'path') {
+                    $err += readconfig($v, $conf, include => 1, @_);
+                } elsif ($k eq 'pathopt') {
+                    $err += readconfig($v, $conf, include => 1, @_)
+                        if -f $v;
+                } elsif ($k eq 'glob') {
+                    foreach my $file (bsd_glob($v, 0)) {
+                        $err += readconfig($file, $conf, include => 1, @_);
+                    }
+                } else {
+                    err("$file:$line: unknown keyword");
+                    ++$err;
+                }
+                next;
+            }
+
+            if (defined($kw)) {
+                my $x = $kw->{$k};
+                if (!defined($x)) {
+                    err("$file:$line: unknown keyword $k");
+                    ++$err;
+                    next;
+                } elsif (ref($x) eq 'HASH') {
+                    if (exists($x->{re})) {
+                        if ($v !~ /$x->{re}/) {
+                            err("$file:$line: invalid value for $k");
+                            ++$err;
+                            next;
+                        }
+                        if (exists($x->{check})
+                            and !&{$x->{check}}($k, $v, "$file:$line")) {
+                            ++$err;
+                            next;
+                        }
+                    } elsif (exists($x->{check})) {
+                        if (!&{$x->{check}}($k, $v, "$file:$line")) {
+                            ++$err;
+                            next;
+                        }
+                    } elsif (!exists($x->{var}) and
+                             !exists($x->{parser}) and
+                             !exists($x->{mandatory})) {
+                        err("$file:$line: unknown keyword $k");
+                        ++$err;
+                        next;
+                    }
+                    if (exists($x->{parser})
+                        and !&{$x->{parser}}($k, \$v, "$file:$line")) {
+                        ++$err;
+                        next;
+                    }
+                }
+            }
+
+            $section->{$k} = $v;
+        } else {
+                err("$file:$line: malformed line");
+            ++$err;
+            next;
+        }
+    }
+    close $fd;
+    exit(EX_CONFIG) if $err;
 }
@@ -85,3 +258,3 @@ sub valid_domain_name {
     my $name = shift;
-    $name =~ s/^\*\.// if ($allow_wildcard_domains);
+    $name =~ s/^\*\.// if ($config{core}{'allow-wildcards'});
     foreach my $label (split(/\./, $name)) {
@@ -99,5 +272,5 @@ sub get_cnames($) {
 
-    foreach my $file (glob "$dir/$confpat") {
+    foreach my $file (glob "$dir/$config{core}{'apache-config-pattern'}") {
         next unless (-f $file);
-        print STDERR "$script: reading cnames from $file\n" if ($debug > 2);
+        print STDERR "$progname: reading cnames from $file\n" if ($debug > 2);
         
@@ -116,9 +289,9 @@ sub get_cnames($) {
                     unless (valid_domain_name($name)) {
-                        print STDERR "$script: $file:$line: $name: invalid domain name\n";
+                        print STDERR "$progname: $file:$line: $name: invalid domain name\n";
                         next;
                     }
-                    foreach my $z (@zone) {
+                    foreach my $z (keys %{$config{zone}}) {
                         if ($name =~ /.*\.$z$/) {
                             if ($name =~ /^\*\.(.+)/ and $1 eq $z) {
-                                print STDERR "$script: $file:$line: $name: first-level wildcard\n";
+                                print STDERR "$progname: $file:$line: $name: first-level wildcard\n";
                                 next;
@@ -143,3 +316,3 @@ sub read_cname_list($) {
     if (-f $file) {
-        open(my $fd, "<", $file) or abend(1, "cannot open $file: $!");
+        open(my $fd, "<", $file) or abend(EX_NOINPUT, "cannot open $file: $!");
         while (<$fd>) {
@@ -163,3 +336,4 @@ sub write_cname_list {
 
-    open(my $fd, ">", $file) or abend(1, "cannot open $file for writing: $!");
+    open(my $fd, ">", $file) or
+        abend(EX_CANTCREAT, "cannot open $file for writing: $!");
     foreach my $h (sort keys %hash) {
@@ -171,3 +345,2 @@ sub write_cname_list {
 sub ns_update {
-    my $resolver = shift;
     my $name = shift;
@@ -177,3 +350,5 @@ sub ns_update {
 
-    print STDERR "$script: updating $name in $domain: ".
+    my $resolver = get_zone_resolver($domain);
+
+    print STDERR "$progname: updating $name in $domain: ".
         join(',', map { "$_ => $hash{$_}" } keys %hash) .
@@ -191,3 +366,3 @@ sub ns_update {
     }
-    $update->sign_tsig(@tsig_args) if ($#tsig_args >= 0);
+    zone_sign_tsig($update, $domain);
     my $reply = $resolver->send($update);
@@ -195,5 +370,5 @@ sub ns_update {
         if ($reply->header->rcode eq 'NOERROR') {
-            print STDERR "$script: update successful\n" if ($debug>3);
+            print STDERR "$progname: update successful\n" if ($debug>3);
         } elsif ($ignorerr{$reply->header->rcode}) {
-            print STDERR "$script: ignoring " . $reply->header->rcode . ': ' .
+            print STDERR "$progname: ignoring " . $reply->header->rcode . ': ' .
                 join(',', map { "$_ => $hash{$_}" } keys %hash) . "\n"
@@ -205,3 +380,3 @@ sub ns_update {
                 $reply->header->rcode);
-            $status = 2;
+            $status = EX_NOTUPDATED;
             return 0;
@@ -213,3 +388,3 @@ sub ns_update {
             $resolver->errorstring);
-        $status = 2;
+        $status = EX_NOTUPDATED;
         return 0;
@@ -219,2 +394,33 @@ sub ns_update {
 
+sub get_zone_resolver {
+    my $zone = shift;
+    unless (defined($config{zone}{$zone}{resolver})) {
+        my $resolver = new Net::DNS::Resolver;
+        $resolver->nameservers($config{zone}{$zone}{server})
+            if defined $config{zone}{$zone}{server};
+        $config{zone}{$zone}{resolver} = $resolver;
+    }
+    return $config{zone}{$zone}{resolver};
+}
+
+sub zone_sign_tsig {
+    my ($update, $zone) = @_;
+    my @tsig_args;
+
+    my $zcfg = $config{zone}{$zone};
+    if (exists($zcfg->{'ns-key-file'})) {
+        push @tsig_args, split(/\s+/, $zcfg->{'ns-key-file'});
+    } elsif (exists($zcfg->{'ns-key'})) {
+        push @tsig_args, @{$zcfg->{'ns-key'}};
+    }
+    if ($#tsig_args == -1) {
+        if (exists($config{core}{'ns-key-file'})) {
+            push @tsig_args, split(/\s+/, $config{core}{'ns-key-file'});
+        } elsif (exists($config{core}{'ns-key'})) {
+            push @tsig_args, @{$config{core}{'ns-key'}};
+        }
+    }
+    $update->sign_tsig(@tsig_args) if ($#tsig_args >= 0);
+}
+
 sub update_cnames_from_hash {
@@ -222,8 +428,8 @@ sub update_cnames_from_hash {
     
-    print STDERR "$script: " . keys(%hash) . " names to update\n"
+    print STDERR "$progname: " . keys(%hash) . " names to update\n"
         if ($debug > 2);
-    my %oldhash = read_cname_list($cnamelist);
+    my %oldhash = read_cname_list($config{core}{cache});
     my @namelist = sort(keys(%hash));
-    if (join(",", @namelist) eq join(".", sort(keys(%oldhash)))) {
-        print STDERR "$script: nothing to update\n" if ($debug);
+    if (join(",", @namelist) eq join(",", sort(keys(%oldhash)))) {
+        print STDERR "$progname: nothing to update\n" if ($debug);
         return;
@@ -231,5 +437,2 @@ sub update_cnames_from_hash {
 
-    my $resolver = new Net::DNS::Resolver;
-    $resolver->nameservers($nameserver) if defined($nameserver);
-    
     my $name;
@@ -239,3 +442,3 @@ sub update_cnames_from_hash {
         } else {
-            ns_update($resolver, $name, $hash{$name},
+            ns_update($name, $hash{$name},
                       prereq => yxdomain($name),
@@ -243,6 +446,6 @@ sub update_cnames_from_hash {
                       ignore => 'NXDOMAIN');
-            print STDERR "$script: $name $ttl CNAME $host\n" if ($debug);
+            print STDERR "$progname: $name $config{core}{ttl} CNAME $config{core}{hostname}\n" if ($debug);
             delete $hash{$name}
-                unless ns_update($resolver, $name, $hash{$name},
-                             update => rr_add("$name $ttl CNAME $host"));
+                unless ns_update($name, $hash{$name},
+                             update => rr_add("$name $config{core}{ttl} CNAME $config{core}{hostname}"));
         }
@@ -251,3 +454,3 @@ sub update_cnames_from_hash {
     foreach $name (keys %oldhash) {
-        ns_update($resolver, $name, $oldhash{$name},
+        ns_update($name, $oldhash{$name},
                   prereq => yxrrset("$name CNAME"),
@@ -257,3 +460,3 @@ sub update_cnames_from_hash {
 
-    write_cname_list($cnamelist, %hash);
+    write_cname_list($config{core}{cache}, %hash);
 }
@@ -265,13 +468,10 @@ sub update_cnames_from_dir($) {
 sub nscleanup {
-    print STDERR "$script: Removing DNS CNAME records\n" if ($debug);
-
-    my $resolver = new Net::DNS::Resolver;
-    $resolver->nameservers($nameserver) if defined($nameserver);
+    print STDERR "$progname: Removing DNS CNAME records\n" if ($debug);
 
-    my %hash = read_cname_list($cnamelist);
+    my %hash = read_cname_list($config{core}{cache});
     foreach my $name (keys %hash) {
-        print STDERR "$script: removing $name from $hash{$name}\n"
+        print STDERR "$progname: removing $name from $hash{$name}\n"
             if ($debug);
         delete $hash{$name}
-            if ns_update($resolver, $name, $hash{$name},
+            if ns_update($name, $hash{$name},
                          prereq => yxrrset("$name CNAME"),
@@ -281,48 +481,161 @@ sub nscleanup {
 
-    write_cname_list($cnamelist, %hash);
+    write_cname_list($config{core}{cache}, %hash);
+}
+
+###
+sub com_start {
+    abend(EX_USAGE, "too many arguments") unless $#_ == 0;
+    nscleanup();
+    com_reload(@_);
+}
+
+sub com_reload {
+    abend(EX_USAGE, "too many arguments") unless $#_ == 0;
+    my $confdir = -d "$config{core}{'apache-config-directory'}/sites-enabled"
+         ? "$config{core}{'apache-config-directory'}/sites-enabled"
+         : $config{core}{'apache-config-directory'};
+    my %cnames = get_cnames($confdir);
+    update_cnames_from_hash(%cnames);
+    print STDERR "$progname: no cnames defined\n" unless (keys(%cnames) > 0);  
 }
 
+sub com_stop {
+    abend(EX_USAGE, "too many arguments") unless $#_ == 0;
+    nscleanup;
+}
+
+sub com_status {
+    err("status command ignored");
+    my %stat;
+    
+    my %hash = read_cname_list($config{core}{cache});
+    while (my ($name, $zone) = each %hash) {
+        #$name =~ s/.$zone$//;
+        push @{${stat}{$zone}}, $name;
+    }
+
+    foreach my $zone (sort(keys %stat)) {
+        print "Names in zone $zone:\n";
+        foreach my $name (sort(@{$stat{$zone}})) {
+            print " $name\n";
+        }
+    }
+}
 
 ###
-($script = $0) =~ s/.*\///;
+($progname = $0) =~ s/.*\///;
+
+my %comtab = (
+    start    => \&com_start,
+    restart  => \&com_reload,
+    'force-restart' => \&com_start,
+    reload   => \&com_reload,
+    stop     => \&com_stop,
+    status   => \&com_status
+);
+
+sub getcom {
+    my $com = shift;
+
+    while (defined($comtab{$com}) and ref($comtab{$com}) ne 'CODE') {
+        $com = $comtab{$com};
+    }
+    die "internal error: unresolved command alias" unless defined $com;
+    return $comtab{$com} if defined $comtab{$com};
+
+    my @v = map { /^$com/ ? $_ : () } sort keys %comtab;
+    if ($#v == -1) {
+        abend(EX_USAGE, "unrecognized command");
+    } elsif ($#v > 0) {
+        abend(EX_USAGE, "ambiguous command: ".join(', ', @v));
+    }
+    return getcom($v[0]);
+}
+
 
 ## Read configuration
-read_config_file($ENV{'VHOSTCNAME_CONF'} ?
-                 $ENV{'VHOSTCNAME_CONF'} : $config_file);
+sub parse_ns_key {
+    my ($var, $ref, $loc) = @_;
+    my @result;
+    if ($$ref =~ /(.+?)=(.+)/) {
+        push @result, $1, $2;
+        $$ref = \@result;
+    } else {
+        err("$loc: $var argument must be must be NAME=KEY");
+        return 0;
+    }
+    return 1;
+}
 
-GetOptions("help" => \$man,
-           "h" => \$help,
-           "debug|d+" => \$debug,
-           "dry-run|n" => \$dry_run,
-           "hostname|H=s" => \$host,
-           "apache-config-pattern=s" => \$confpat,
-           "apache-config-directory=s" => \$confdir,
-           "ns-key-file=s" => sub {
-               abend(3, "NS key already set") if ($#tsig_args >= 0);
-               push @tsig_args, $_[1];
-           },
-           "ns-key=s" => sub {
-               abend(3, "NS key already set") if ($#tsig_args >= 0);
-               if ($_[1] =~ /(.+?)=(.+)/) {
-                   push @tsig_args, $1;
-                   push @tsig_args, $2;
+sub parse_boolean {
+    my ($var, $ref, $loc) = @_;
+    my %bool = ( yes => 1,
+                 no => 0,
+                 true => 1,
+                 false => 0,
+                 t => 1,
+                 nil => 0,
+                 f => 0,
+                 on => 1,
+                 off => 0,
+                 1 => 1,
+                 0 => 0);
+
+    my $s = $$ref;
+    $s =~ tr/A-Z/a-z/;
+    if (exists($bool{$s})) {
+        $$ref = $bool{$s};
                } else {
-                   abend(3, "argument to --ns-key must be NAME=KEY");
+        err("$loc: argument must be boolean");
+        return 0;
+    }
+    return 1;
                }
+
+my %kw = (
+    core => {
+        section => {
+            'apache-config-directory' => 1,
+            'apache-config-pattern' => 1,
+            'cache' => 1,
+            'server' => 1,
+            'ttl' => 1,
+            'ns-key' => { parser => \&parse_ns_key },
+            'ns-key-file' => 1,
+            'hostname' => 1,
+            'allow-wildcards' => { parser => \&parse_boolean }
+        },
            },
-           "cname-file=s" => \$cnamelist,
-           "zone|z=s@" => \@zone,
-           "ttl=i" => \$ttl,
-           "server=s" => \$nameserver,
-           "allow-wildcard-domains" => \$allow_wildcard_domains
-           ) or exit(3);
-
-pod2usage(-message => "$script: update DNS from Apache virtual host configuration",
-          -exitstatus => 0) if $help;
-pod2usage(-exitstatus => 0, -verbose => 2) if $man;
-
-unless (defined($confdir)) {
+    zone => {
+        section => {
+            'server' => 1,
+            'ttl' => 1,
+            'ns-key' => { parser => \&parse_ns_key },
+            'ns-key-file' => 1
+        },
+    }
+);
+
+GetOptions("help" => sub {
+              pod2usage(-exitstatus => EX_OK, -verbose => 2);
+           },
+           "h" => sub {
+              pod2usage(-message => "$progname: $progdescr",
+                        -exitstatus => EX_OK);
+           },
+           "usage" => sub {
+              pod2usage(-exitstatus => EX_OK, -verbose => 0);
+           },
+           
+           "debug|d+" => \$debug,
+           "dry-run|n" => \$dry_run,
+           "config|c=s" => \$config_file,
+           ) or exit(EX_USAGE);
+
+readconfig($config_file, \%config, kw => \%kw);
+
+unless (defined($config{core}{'apache-config-directory'})) {
     foreach my $dir ("/etc/apache2", "/etc/httpd") {
         if (-e "$dir/sites-enabled" and -e "$dir/sites-available") {
-            $confdir = $dir;
+            $config{core}{'apache-config-directory'} = $dir;
             last;
@@ -330,3 +643,3 @@ unless (defined($confdir)) {
         if (-e "$dir/vhosts.d") {
-            $confdir = "$dir/vhosts.d";
+            $config{core}{'apache-config-directory'} = "$dir/vhosts.d";
             last;
@@ -334,9 +647,10 @@ unless (defined($confdir)) {
     }
-    abend(3,
-          "don't know where virtual host configurations are located; use --apache-config-directory option")
-        unless defined($confdir);
+    abend(EX_CONFIG,
+          "don't know where virtual host configurations are located; define apache-config-directory")
+        unless defined($config{core}{'apache-config-directory'});
 }
 
-$host = hostname() unless defined($host);
-push(@zone, $host) if ($#zone == -1);
+$config{core}{hostname} = hostname() unless defined($config{core}{hostname});
+$config{zone}{$host} = {} unless exists $config{zone};
+
 $debug++ if ($dry_run);
@@ -344,4 +658,4 @@ $debug++ if ($dry_run);
 if ($#ARGV == -1) {
-    abend(3, "command not given") unless ($ENV{'DIREVENT_FILE'});
-    print STDERR "$script: started as direvent handler for " .
+    abend(EX_USAGE, "command not given") unless ($ENV{'DIREVENT_FILE'});
+    print STDERR "$progname: started as direvent handler for " .
                  "$ENV{'DIREVENT_GENEV_NAME'} on $ENV{'DIREVENT_FILE'}\n"
@@ -350,5 +664,6 @@ if ($#ARGV == -1) {
     my $update_dir;
+    my $confdir = $config{core}{'apache-config-directory'};
     if (-d "$confdir/sites-available" && -d "$confdir/sites-enabled") {
         if ($cwd eq "$confdir/sites-available") {
-            foreach my $file (glob "$confdir/sites-enabled/$confpat") {
+            foreach my $file (glob "$confdir/sites-enabled/$config{core}{'apache-config-pattern'}") {
                 next unless (-l $file);
@@ -368,18 +683,7 @@ if ($#ARGV == -1) {
     update_cnames_from_dir($update_dir) if defined($update_dir);
-} elsif ($#ARGV != 0) {
-    abend(3, "too many arguments");
-} elsif ($ARGV[0] =~ /^start|restart|force-restart|reload$/) {
-    nscleanup if ($ARGV[0] =~ /start$/);
-    my %cnames = get_cnames(-d "$confdir/sites-enabled" ?
-                            "$confdir/sites-enabled" : $confdir);
-    update_cnames_from_hash(%cnames);
-    print STDERR "$script: no cnames defined\n" unless (keys(%cnames) > 0);
-} elsif ($ARGV[0] eq "stop") {
-    nscleanup;
-} elsif ($ARGV[0] eq "status") {
-    err("status command ignored");
-} else {
-    abend(3, "invalid command, try $script --help for more info");
 }
 
+my $command = getcom($ARGV[0]);
+&{$command}(@ARGV);
+
 exit($status);
@@ -433,2 +737,8 @@ corresponding B<direvent.conf>(5) entry:
 
+Unless the program is started as a B<direvent>(8) handler, exactly one
+command must be given in the command line.  A command may be supplied
+in full or abbreviated form.  Any unambiguous abbreviation is allowed.
+
+Available commands are:    
+    
 =over 4
@@ -437,4 +747,4 @@ corresponding B<direvent.conf>(5) entry:
 
-Scan the apache configuration files and register all server names matching
-the supplied zones.
+Scan the apache configuration files and register all server names that
+match the configured zones.
     
@@ -444,5 +754,14 @@ Deregister all hostnames registered previously.
 
-=item B<restart>, B<force-restart>, B<reload>
+=item B<restart>, B<reload>
 
-Same as running B<vhostcname stop; vhostcname start>.    
+Builds a list of names from the apache configuration (I<apache-list>) and
+compares them with the names registered at the previous run (I<cache>).  If
+the two lists differ, the names present in I<apache-list>, but absent in
+I<cache> are registered.  The names present in I<cache>, but lacking in
+I<apache-list> are deleted from the DNS.
+
+=item B<force-restart>
+
+Deregister all hostnames registered previously, rescan Apache files, and
+register all names that match the configured zones.
     
@@ -450,3 +769,3 @@ Same as running B<vhostcname stop; vhostcname start>.
 
-Ignored    
+Displays registered host names.
     
@@ -458,9 +777,52 @@ Ignored
 
-=item B<--allow-wildcard-domains>
+=item B<-c>, B<--config=>I<FILE> 
+
+Read configuration from I<FILE> instead of the default location
+(F</etc/vhostcname.conf>).
+    
+=item B<-d>, B<--debug>
+
+Increases the debug level.  Multiple B<-d> options are allowed.
+    
+=item B<-n>, B<--dry-run>,
+
+Enables I<dry-run> mode: print what would have been done without actually
+doing it.    
+
+=item B<--help>
+
+Displays B<vhostcname> man page.
+    
+=item B<-h>
+
+Displays a short help summary and exits.
+
+=item B<--usage>
+
+Displays a short command line syntax reminder.    
+    
+=back
+
+=head1 CONFIGURATION FILE
+
+Configuration is read from F</etc/vhostcname.conf> or a file specified
+by the B<--config> (B<-c>) command line option.  The file consists of
+a number of variable assignments (I<variable> B<=> I<value>), grouped into
+sections.  Whitespace is ignored, except that it serves to separate input
+tokens.  I<value> is read verbatim, including eventual whitespace characters
+that can appear within it.
+
+A section begins with the line containing its name within square brackets
+(e.g. B<[core]>).  The name can be followed by one or more arguments, if
+the section semantics requires so (e.g. B<[zone example.com]>).
+
+The following sections are recognized:
+
+=over 4
+
+=item B<[core]>
 
-Allow the use of wildcard (B<*>).  When this option is in effect, a wildcard
-will be allowed if it is the very first label in a domain name and it is
-separated from the base zone (see the B<--zone> option) by one or more labels.
+=over 8
     
-=item B<--apache-config-directory=>I<DIR>
+=item B<apache-config-directory => I<DIR>
 
@@ -476,3 +838,3 @@ terminate if unable to do that.
     
-=item B<--apache-config-pattern=>I<GLOB>
+=item B<apache-config-pattern => I<PATTERN>
 
@@ -480,36 +842,47 @@ Shell globbing pattern for virtual host configuration files.  By default,
 B<*> is used, meaning that B<vhostcname> will scan all files in the
-configuration directory.
+configuration directory (note: that includes backup copies too!).
     
-=item B<--cname-file=>I<NAME>
+=item B<cache => I<FILE>
 
-Name of the file where B<vhostcname> will keep successfully registered
+Name of the cache file where B<vhostcname> keeps successfully registered
 host names.  Default is B</var/run/vhostcname.cache>.    
     
-=item B<-d>, B<--debug>
+=item B<hostname => I<HOSTNAME>
 
-Increases the debug level.  Multiple B<-d> options are allowed.
+Sets the hostname.  Use this if B<vhostcname> is unable to correctly
+determine it.
     
-=item B<-n>, B<--dry-run>,
+=item B<allow-wildcards => I<BOOL>
 
-Enables I<dry-run> mode: print what would have been done without actually
-doing it.    
+Allow the use of wildcard (B<*>) in host names.  When this option is in
+effect, a wildcard will be allowed if it is the very first label in a domain
+name and it is separated from the base zone (see the B<zone> section) by one
+more labels.
     
-=item B<--help>
+I<BOOL> is one of B<yes>, B<true>, B<t>, B<on>, or B<1> to allow wildcards,
+or one of B<no>, B<false>, B<f>, B<nil>, B<off>, B<0> to disallow them (the
+default).    
 
-Displays B<vhostcname> man page.
+=back
     
-=item B<-h>
+The following variables provide defaults for zones that lack the
+corresponding settings:    
 
-Displays a short help summary and exits.
+=over 8    
     
-=item B<-H>, B<--hostname>=I<NAME>
+=item B<server => I<HOST>
 
-Sets the hostname.  Use this if B<vhostcname> is unable to correctly
-determine it.
+Name of the DNS server to use.  Normally B<vhostcname> determines what server
+to use based on the B<SOA> record of the zone to be updated, so this option
+is rarely needed.
     
-=item B<--ns-key=>I<NAME>=I<KEY>
+=item B<ttl => I<SECONDS>
 
-Define the TSIG key.   
+TTL value for new DNS records.  Default is 3600.
     
-=item B<--ns-key-file=>I<KEYFILE>
+=item B<ns-key => I<NAME>=I<HASH>
+
+Defines the TSIG key.
+
+=item B<ns-key-file => I<FILE>
 
@@ -519,46 +892,41 @@ file can be used.
 
-This option cannot be used together with B<--ns-key>.    
+If both <ns-key> and B<ns-key-file> are used, the latter is given preference.
 
-=item B<--server=>I<NAME>
+=back
 
-Name of the DNS server to use.  Normally B<vhostcname> determines what server
-to use based on the B<SOA> record of the zone to be updated, so this option
-is rarely needed.    
+=item B<[zone I<NAME>]>    
     
-=item B<--ttl=>I<TIME>
+The B<zone> section informs B<vhostcname> that it should handle names
+in zone I<NAME>.  Any number of B<[zone]> sections can be defined.  If
+none is defined, B<vhostcname> will take hostname as the name of the zone
+to update.    
 
-TTL value for new DNS records.  Default is 3600.    
+The variables in a B<zone> section define parameters to be used for that
+particular zone.  As such, none of them is mandatory.  If the zone I<NAME>
+uses default settings (or settings, defined in the B<[core]> section),
+the section can be empty.    
     
-=item B<--zone=>I<NAME>
+=over 8
 
-Name of the zone which B<vhostcname> can update.  Multiple B<--zone> options
-can be given.
+=item B<server => I<HOST>
 
-If no B<--zone> option is given, B<vhostcname> will take hostname as the
-name of the zone.
+Name of the DNS server to use when updating this zone.
 
-=back
+=item B<ttl => I<SECONDS>
 
-=head1 CONFIGURATION FILE
+TTL for records in this zone.
 
-If the file B<etc/vhostcname.conf> exists, the program will read its
-configuration from it.  A familiar UNIX configuration format is used.
-Empty lines and UNIX comments are ignored.  Each non-empty line is either an
-option name, or option assignment, i.e. B<opt>=B<val>, with any amount of
-optional whitespace around the equals sign.  Valid option names are
-the same as the long command line options, but without the leading B<-->.
-For example:
+=item B<ns-key => I<NAME>=I<HASH>
 
-  zone   = vhost.example.com
-  ns-key-file = /etc/bind/Kvhost+157+43558.key
-  ttl    = 3600
+TSIG key.
 
-=head1 ENVIRONMENT
+=item B<ns-key-file => I<FILE>
 
-=over 4
+Name of the key file.  The argument should be the name of a file
+generated by the B<dnssec-keygen> utility.  Either B<.key> or B<.private>
+file can be used.
 
-=item B<VHOSTCNAME_CONF>
+If both <ns-key> and B<ns-key-file> are used, the latter is given preference.
 
-The name of the configuration file to use instead of the default
-F</etc/vhostcname.conf>.
+=back
 
@@ -576,19 +944,21 @@ Success
 
-Operating system error (unable to open file, etc.)
+Some of the host names could not be updated.    
 
-=item 2
+=item 64
 
-Some of the host names could not be registered.    
+Command line usage error.
     
-=item 3
+=item 66
 
-Command line usage error    
+Required input file cannot be opened.
 
-=back
+=item 73
     
-=head1 BUGS
+Required output file cannot be created or written.
 
-Only one key file can be given.  This means that if you use multiple
-B<--zone> options, all zones must be configured to accept the same
-DNSSEC key.  Ditto for the B<--server> option.    
+=item 78
+
+Configuration error.    
+
+=back