Class: Net::DNS::RR::LOC

Inherits:
Net::DNS::RR show all
Defined in:
lib/Net/DNS/RR/LOC.rb

Overview

NAME

Net::DNS::RR::LOC - DNS LOC resource record

head1 DESCRIPTION

Class for DNS Location (LOC) resource records. See RFC 1876 for details.

head1 COPYRIGHT

Copyright © 1997-2002 Michael Fuhr.

Portions Copyright © 2002-2004 Chris Reinhardt.

Ruby version Copyright © 2006 AlexD (Nominet UK)

All rights reserved. This program is free software; you may redistribute it and/or modify it under the same terms as Perl itself. Some of the code and documentation is based on RFC 1876 and on code contributed by Christopher Davis.

SEE ALSO

Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Header, Net::DNS::Question, Net::DNS::RR, RFC 1876

Constant Summary collapse

POWEROFTEN =

Powers of 10 from 0 to 9 (used to speed up calculations).

[1, 10, 100, 1_000, 10_000, 100_000, 1_000_000, 10_000_000, 100_000_000, 1_000_000_000]
REFERENCE_ALT =

Reference altitude in centimeters (see RFC 1876).

100_000 * 100
REFERENCE_LATLON =

Reference lat/lon (see RFC 1876).

2**31
CONV_SEC =

Conversions to/from thousandths of a degree.

1000
CONV_MIN = 
60 * CONV_SEC
CONV_DEG = 
60 * CONV_MIN
DEFAULT_MIN =

Defaults (from RFC 1876, Section 3).

0
DEFAULT_SEC = 
0
DEFAULT_SIZE = 
1
DEFAULT_HORIZ_PRE = 
10_000
DEFAULT_VERT_PRE = 
10

Constants inherited from Net::DNS::RR

RRS

Instance Attribute Summary collapse

Attributes inherited from Net::DNS::RR

#name, #rdata, #rdlength, #rrclass, #ttl, #type

Instance Method Summary collapse

Methods inherited from Net::DNS::RR

#_canonicalRdata, #_canonicaldata, _get_subclass, _name2wire, #_name2wire, build_regex, create, #create_rrsort_func, #data, #get_rrsort_func, #init, #init_rrsort_func, #inspect, new_from_data, new_from_hash, new_from_string, #set_rrsort_func

Instance Attribute Details

#altitude ⇒ Object

Returns the altitude of the center of the sphere described by the size method, in centimeters, from a base of 100,000m below the WGS 84 reference spheroid used by GPS.

print "altitude = ", rr.altitude, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 90

def altitude
  @altitude
end

#horiz_pre ⇒ Object

Returns the horizontal precision of the data, in centimeters.

print "horiz_pre = ", rr.horiz_pre, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 63

def horiz_pre
  @horiz_pre
end

#latitude ⇒ Object

Returns the latitude of the center of the sphere described by the size method, in thousandths of a second of arc. 2**31 represents the equator; numbers above that are north latitude.

print "latitude = ", rr.latitude, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 75

def latitude
  @latitude
end

#longitude ⇒ Object

Returns the longitude of the center of the sphere described by the size method, in thousandths of a second of arc. 2**31 represents the prime meridian; numbers above that are east longitude.

print "longitude = ", rr.longitude, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 83

def longitude
  @longitude
end

#size ⇒ Object

Returns the diameter of a sphere enclosing the described entity, in centimeters.

print "size = ", rr.size, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 58

def size
  @size
end

#version ⇒ Object

Returns the version number of the representation; programs should always check this. C<Net::DNS> currently supports only version 0.

print "version = ", rr.version, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 52

def version
  @version
end

#vert_pre ⇒ Object

Returns the vertical precision of the data, in centimeters.

print "vert_pre = ", rr.vert_pre, "\n"



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# File 'lib/Net/DNS/RR/LOC.rb', line 68

def vert_pre
  @vert_pre
end

Instance Method Details

#dms2latlon(deg, min, sec, hem) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 305

def dms2latlon(deg, min, sec, hem)
  retval=0
  
  retval = (deg * CONV_DEG) + (min * CONV_MIN) + (sec * CONV_SEC);
  retval = -retval if ((hem != nil) && ((hem == "S") || (hem == "W")));
  retval += REFERENCE_LATLON;
  return retval;
end

#latlon ⇒ Object

Returns the latitude and longitude as floating-point degrees. Positive numbers represent north latitude or east longitude; negative numbers represent south latitude or west longitude.

lat, lon = rr.latlon
system("xearth", "-pos", "fixed #{lat} #{lon}")



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# File 'lib/Net/DNS/RR/LOC.rb', line 321

def latlon
  retlat, retlon = nil
  
  if (@version == 0)
    retlat = latlon2deg(@latitude);
    retlon = latlon2deg(@longitude);
  end
  
  return retlat, retlon
end

#latlon2deg(rawmsec) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 332

def latlon2deg(rawmsec)
  deg=0;
  
  deg = (rawmsec - reference_latlon) / CONV_DEG;
  return deg;
end

#latlon2dms(rawmsec, hems) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 287

def latlon2dms(rawmsec, hems)
  # Tried to use modulus here, but Perl dumped core if
  # the value was >= 2**31.
  
  abs  = (rawmsec - REFERENCE_LATLON).abs;
  deg  = (abs / CONV_DEG).round;
  abs  -= deg * CONV_DEG;
  min  = (abs / CONV_MIN).round; 
  abs -= min * CONV_MIN;
  sec  = (abs / CONV_SEC).round;  # $conv_sec
  abs -= sec * CONV_SEC;
  msec = abs;
  
  hem = hems[(rawmsec >= REFERENCE_LATLON ? 0 : 1), 1]
  
  return sprintf("%d %02d %02d.%03d %s", deg, min, sec, msec, hem);
end

#new_from_data(data, offset) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 112

def new_from_data(data, offset)
  if (@rdlength > 0)
    version = data.unpack("\@#{offset} C")[0]
    offset+=1
    
    @version = version;
    
    if (version == 0)
      size = data.unpack("\@#{offset} C")[0];
      @size = precsize_ntoval(size);
      offset+=1;
      
      horiz_pre = data.unpack("\@#{offset} C")[0];
      @horiz_pre = precsize_ntoval(horiz_pre);
      offset+=1;
      
      vert_pre = data.unpack("\@#{offset} C")[0];
      @vert_pre = precsize_ntoval(vert_pre);
      offset+=1
      
      @latitude = data.unpack("\@#{offset} N")[0];
      offset += Net::DNS::INT32SZ;
      
      @longitude = data.unpack("\@#{offset} N")[0];
      offset += Net::DNS::INT32SZ;
      
      @altitude = data.unpack("\@#{offset} N")[0]
      offset += Net::DNS::INT32SZ;
    else
      # What to do for unsupported versions?
    end
  end
end

#new_from_hash(values) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 146

def new_from_hash(values)
  if values.has_key?(:size)
    @size = values[:size]
  else
    @size = DEFAULT_SIZE
  end
  if values.has_key?(:horiz_pre)
    @horiz_pre = values[:horiz_pre]
  else
    @horiz_pre = DEFAULT_HORIZ_PRE * 100
  end
  if values.has_key?(:vert_pre)
    @vert_pre = values[:vert_pre]
  else
    @vert_pre = DEFAULT_VERT_PRE * 100
  end
  if values.has_key?(:latitude)
    @latitude = values[:latitude]
  end
  if values.has_key?(:longitude)
    @longitude = values[:longitude]
  end
  if values.has_key?(:altitude)
    @altitude = values[:altitude]
  end
  if values.has_key?(:version)
    @version = values[:version]
#          else
#            @version = DEFAULT_VERSION
  end
end

#new_from_string(string) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 178

def new_from_string(string)
  if (string && 
      string =~ /^ (\d+) \s+		# deg lat
   ((\d+) \s+)?		# min lat
   (([\d.]+) \s+)?	# sec lat
   (N|S) \s+		# hem lat
   (\d+) \s+		# deg lon
   ((\d+) \s+)?		# min lon
   (([\d.]+) \s+)?	# sec lon
   (E|W) \s+		# hem lon
   (-?[\d.]+) m? 	# altitude
   (\s+ ([\d.]+) m?)?	# size
   (\s+ ([\d.]+) m?)?	# horiz precision
   (\s+ ([\d.]+) m?)? 	# vert precision
    /ix)  # 
    
    # What to do for other versions?
    version = 0;
    
    latdeg, latmin, latsec, lathem = $1.to_i, $3.to_i, $5.to_i, $6;
    londeg, lonmin, lonsec, lonhem = $7.to_i, $9.to_i, $11.to_i, $12
    alt, size, horiz_pre, vert_pre = $13.to_i, $15.to_i, $17.to_i, $19.to_i
    
    latmin    = DEFAULT_MIN       unless latmin;
    latsec    = DEFAULT_SEC       unless latsec;
    lathem    = lathem.upcase;
    
    lonmin    = DEFAULT_MIN       unless lonmin;
    lonsec    = DEFAULT_SEC       unless lonsec;
    lonhem    = lonhem.upcase
    
    size      = DEFAULT_SIZE      unless size;
    horiz_pre = DEFAULT_HORIZ_PRE unless horiz_pre;
    vert_pre  = DEFAULT_VERT_PRE  unless vert_pre;
    
    @version   = version;
    @size      = size * 100;
    @horiz_pre = horiz_pre * 100;
    @vert_pre  = vert_pre * 100;
    @latitude  = dms2latlon(latdeg, latmin, latsec, lathem);
    @longitude = dms2latlon(londeg, lonmin, lonsec, lonhem);
    @altitude  = alt * 100 + REFERENCE_ALT;
  end
end

#precsize_ntoval(prec) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 272

def precsize_ntoval(prec)
  mantissa = ((prec >> 4) & 0x0f) % 10;
  exponent = (prec & 0x0f) % 10;
  return mantissa * POWEROFTEN[exponent];
end

#precsize_valton(val) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 278

def precsize_valton(val)
  exponent = 0;
  while (val >= 10)
    val /= 10;
    exponent+=1
  end
  return (val.round << 4) | (exponent & 0x0f);
end

#rdatastr ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 223

def rdatastr
  rdatastr=""
  
  if (defined?@version)
    if (@version == 0)
      lat       = @latitude;
      lon       = @longitude;
      altitude  = @altitude;
      size      = @size;
      horiz_pre = @horiz_pre;
      vert_pre  = @vert_pre;
      
      altitude   = (altitude - REFERENCE_ALT) / 100;
      size      /= 100;
      horiz_pre /= 100;
      vert_pre  /= 100;
      
      rdatastr = latlon2dms(lat, "NS") + " " +
      latlon2dms(lon, "EW") + " " +
      sprintf("%.2fm", altitude)  + " " +
      sprintf("%.2fm", size)      + " " +
      sprintf("%.2fm", horiz_pre) + " " +
      sprintf("%.2fm", vert_pre);
    else
      rdatastr = "; version " + @version + " not supported";
    end
  else
    rdatastr = '';
  end
  
  return rdatastr;
end

#rr_rdata(*args) ⇒ Object 



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# File 'lib/Net/DNS/RR/LOC.rb', line 256

def rr_rdata(*args)
  rdata = "";
  
  if (defined?@version)
    rdata += [@version].pack("C");
    if (@version == 0)
      rdata += [precsize_valton(@size), precsize_valton(@horiz_pre), precsize_valton(@vert_pre)].pack("C3");
      rdata += [@latitude, @longitude, @altitude].pack("N3");
    else
      # What to do for other versions?
    end
  end
  
  return rdata;
end