RFR(S): JDK-8041435 Make JDWP socket connector accept only local connections by default

[Daniel D. Daugherty]

On 5/15/14 5:50 AM, Dmitry Samersoff wrote:
> Hi Everyone,
>
> Please review the fix:
>
> http://cr.openjdk.java.net/~dsamersoff/JDK-8041435/webrev.01/

src/share/transport/socket/socketTransport.c
     line 200:   // it lookups "localhost" and return 127.0.0.1 if lookup
         Typo: "it lookups" -> "it looks up"
         Typo: "and return 127.0.0.1" -> "and returns 127.0.0.1"

     line 210:     return dbgsysHostToNetworkLong(INADDR_LOOPBACK);
         nit: indent should be 4-spaces (for this file)

     line 235:         u_short port = (u_short)atoi(address+10);
         Will this crash on "localhost:"? (colon, but no port number)

     line 236:         sa->sin_port = dbgsysHostToNetworkShort(port);
         If atoi() on line 235 is passed a non-decimal, what will the
         value of 'port' be and what will happen here?

     line 241:         u_short port = (u_short)atoi(address+2);
     line 242:         sa->sin_port = dbgsysHostToNetworkShort(port);
         Same questions about these two lines...

     old line 440:     err = parseAddress(addressString, &sa, 0x7f000001);
         Is it bad that my brain automatically translated that HEX
         string into 127.0.0.1? I guess I still remember networking
         code...

I checked out this doc:

http://docs.oracle.com/javase/7/docs/technotes/guides/jpda/conninv.html

and the help message:

$ java -agentlib:jdwp=help
                Java Debugger JDWP Agent Library
                --------------------------------

   (see http://java.sun.com/products/jpda for more information)

jdwp usage: java -agentlib:jdwp=[help]|[<option>=<value>, ...]

Option Name and Value            Description Default
---------------------            ----------- -------
suspend=y|n                      wait on startup? y
transport=<name>                 transport spec                    none
address=<listen/attach address>  transport spec                    ""
server=y|n                       listen for debugger? n
launch=<command line>            run debugger on event             none
onthrow=<exception name>         debug on throw                    none
onuncaught=y|n                   debug on any uncaught? n
timeout=<timeout value>          for listen/attach in milliseconds n
mutf8=y|n                        output modified utf-8 n
quiet=y|n                        control over terminal messages n

Obsolete Options
----------------
strict=y|n
stdalloc=y|n

Examples
--------
   - Using sockets connect to a debugger at a specific address:
     java -agentlib:jdwp=transport=dt_socket,address=localhost:8000 ...
   - Using sockets listen for a debugger to attach:
     java -agentlib:jdwp=transport=dt_socket,server=y,suspend=y ...

Notes
-----
   - A timeout value of 0 (the default) is no timeout.

Warnings
--------
   - The older -Xrunjdwp interface can still be used, but will be removed in
     a future release, for example:
         java -Xdebug -Xrunjdwp:[help]|[<option>=<value>, ...]


I don't think your change requires any doc changes...

Dan


>
> After the fix, JDWP server attempts to guess localhost address and bind
> to it only if no address is specified in command line but user can
> explicitly bind server to all of available addresses by using * as an
> address.
>