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http://issues.apache.org/bugzilla/show_bug.cgi?id=33226 Summary: TTL DNS cache security setting in java.net.InetAddress is not honored when set within Servlet on Sun 1.4.2 VM on linux, but is honored in stand-alone java app Product: Tomcat 4 Version: 4.1.18 Platform: PC OS/Version: Linux Status: NEW Severity: normal Priority: P2 Component: Unknown AssignedTo: tomcat-dev@jakarta.apache.org ReportedBy: [EMAIL PROTECTED] CC: [EMAIL PROTECTED] 1. From within a stand-alone jdk 1.4.2 app, (like in static void main(String[] arg)), do a: java.security.Security.setProperty( "networkaddress.cache.ttl", "0" ); This successfully changes the ttl dns cache setting, because java.security.Security.getProperty( "networkaddress.cache.ttl" ); returns "0". Now, System.out.println( java.net.InetAddress.getByName( "earthlink.net" ) ) will result in a particular IP resolution like: earthlink.net/207.217.121.217 However, "earthlink.net", for example, has multiple IP addresses that it round robins through. This can be seen from printing out InetAddress[] return from: java.net.InetAddress.getAllByName( "earthlink.net" ); Now, subsequent java.net.InetAddress.getByName ( "earthlink.net" ) calls will show IP addresses cycled in a round-robin manner. This all works as expected according to: http://java.sun.com/j2se/1.4.2/docs/api/java/net/InetAddress.html 2. Now, do essentially the same thing in a servlet deployed on Tomcat 4.1.18: In a browser hit this url to execute the servlet code below: http://myHost/servletPath?host=earthlink.net public class TestDnsServlet extends HttpsServlet { private void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Security.setProperty( "networkaddress.cache.ttl", "0" ); try { PrintWriter out = response.getWriter(); String hostname = request.getParameter( "host" ); out.println("<html><body>\n"); out.println("networkaddress.cache.ttl = " + Security.getProperty("networkaddress.cache.ttl") + "<br>\n"); InetAddress[] IP = InetAddress.getAllByName( hostname ); out.println( hostname + ":<BR>\n" ); for (int j=0; j<IP.length; j++) { out.println( " " + IP[j] + "<BR>\n"); } out.println(); for (int j=0; j<20; j++) { out.println( "IP lookup: " + InetAddress.getByName( hostname ) + "<BR>\n" ); } out.println("</body></html>\n"); } catch (UnknownHostException e) { System.err.println( " unknown host" ); } catch (IOException e) { e.printStackTrace(); } } RESULTS of (2): The multiple InetAddress.getByName() calls in the above for-loop all return the first IP returned from InetAddress.getAllByName() as though it is cached, even though the network.cache.ttl setting is clearly changed to "0". This makes it seem like Tomcat is somehow intercepting the call and providing its own implementation?? Perhaps the pluggable DNS Provider made available by JDK 1.4.2 are being used? EXPECTATION: (2) should work the same as (1). -- Configure bugmail: http://issues.apache.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
