rmid(1)rmid(1)NAMErmid - RMI activation system daemon
SYNOPSISrmid [ options ]
DESCRIPTION
The rmid tool starts the activation system daemon. Before activatable
objects can be either registered with the activation system or acti‐
vated in a Java VM, the activation system daemon must be started. See
the RMI Specification and Activation Tutorials for details on how to
write programs that use activatable remote objects.
The daemon can be started by executing the rmid command, and specifying
a security policy file, as follows:
example% rmid -J-Djava.security.policy=rmid.policy
Note: When running Sun's implementation of rmid, by default you will
need to specify a security policy file so that rmid can verify whether
or not the information in each ActivationGroupDesc is allowed to be
used to launch a JVM for an activation group. Specifically, the com‐
mand and options specified by the CommandEnvironment and any Properties
passed to an ActivationGroupDesc's constructor must now be explicitly
allowed in the security policy file for rmid. The value of the
sun.rmi.activation.execPolicy property dictates the policy that rmid
uses to determine whether or not the information in an Activation‐
GroupDesc may be used to launch a JVM for an activation group.
Executing rmid by default
· starts the Activator and an internal registry on the default
port, 1098, and
· binds an ActivationSystem to the name java.rmi.activa‐
tion.ActivationSystem in this internal registry.
To specify an alternate port for the registry, you must specify the
-port option when starting up rmid. For example,
rmid -J-Djava.security.policy=rmid.policy -port 1099
starts the activation system daemon and a registry on the registry's
default port, 1099.
Starting rmid from inetd/xinetd
An alternative to starting rmid from the command line is to configure
inetd (Solaris) or xinetd (Linux) to start rmid on demand.
When rmid starts up, it attempts to obtain an inherited channel (inher‐
ited from inetd/xinetd) by invoking the System.inheritedChannel method.
If the inherited channel is null, then rmid was started from the com‐
mand line, and it starts up as described above.
If the inherited channel is not an instance of java.io.channels.Server‐
SocketChannel, rmid exits.
If the inherited channel is a ServerSocketChannel instance, then rmid
uses the java.net.ServerSocket obtained from the ServerSocketChannel as
the server socket that accepts requests for the remote objects it
exports, namely the registry in which the java.rmi.activation.Activa‐
tionSystem is bound and the java.rmi.activation.Activator remote
object.
The rmid tool, when started from inetd/xinetd, behaves the same as when
it is started from the command line, except:
· Output printed to System.err is redirected
to a file. This file is located in the directory specified by the
java.io.tmpdir system property (typically /var/tmp or /tmp) with the
prefix "rmid-err" and the suffix "tmp".
· The -port option is disallowed. If this
option is specified, rmid will exit with an error message.
· The -log option is required. If this option
is not specified, rmid will exit with an error message.
See the man pages for inetd (Solaris) or xinetd (Linux) for details on
how to configure services to be started on demand.
OPTIONS-CsomeCommandLineOption
Specifies an option that is passed as a command-line argument to
each child process (activation group) of rmid when that process
is created. For example, you could pass a property to each Java
virtual machine spawned by the activation system daemon:
rmid -C-Dsome.property=value
This ability to pass command-line arguments o child processes
can be useful for debugging. For example, the following com‐
mand:
rmid -C-Djava.rmi.server.logCalls=true
will enable server-call logging in all child JVMs.
-JsomeCommandLineOption
Specifies an option that is passed to the java interpreter run‐
ning rmid. For example, to specify that rmid use a policy file
named rmid.policy, the -J option can be used to define the
java.security.policy property on rmid's command line. For exam‐
ple:
rmid -J-Djava.security.policy=rmid.policy
-J-Dsun.rmi.activation.execPolicy=policy
Specifies the policy that rmid employs to check commands and
command-line options used to launch the JVM in which an activa‐
tion group runs. Please note that this option exists only in
Sun's implementation of the RMI activation daemon. If this
property is not specified on the command line, the result is the
same as if -J-Dsun.rmi.activation.execPolicy=default were speci‐
fied. The possible values of policy can be default, policy‐
ClassName, or none:
· default (or if this property is unspecified) The default
execPolicy allows rmid to execute commands with specific com‐
mand-line options only if rmid has been granted permission to
execute those commands and options in the security policy file
that rmid uses. Only the default activation group implementa‐
tion can be used with the default execution policy.
rmid launches a JVM for an activation group using the informa‐
tion in the group's registered activation group descriptor, an
ActivationGroupDesc. The group descriptor specifies an
optional ActivationGroupDesc.CommandEnvironment which includes
the command to execute to start the activation group as well
as any command line options to be added to the command line.
By default, rmid uses the java command found in java.home.
The group descriptor also contains properties overrides that
are added to the command line as options defined as:
-Dproperty=value
The permission com.sun.rmi.rmid.ExecPermission is used to
grant rmid permission to execute a command, specified in the
group descriptor's CommandEnvironment to launch an activation
group. The permission com.sun.rmi.rmid.ExecOptionPermission
is used to allow rmid to use command-line options, specified
as properties overrides in the group descriptor or as options
in the CommandEnvironment, when launching the activation
group.
When granting rmid permission to execute various commands and
options, the permissions ExecPermission and ExecOptionPermis‐
sion need to be granted universally (that is, granted to all
code sources).
ExecPermission
The ExecPermission class represents permission for rmid
to execute a specific command to launch an activation
group.
Syntax
The name of an ExecPermission is the path name of a
command to grant rmid permission to execute. A path
name that ends in "/*" indicates all the files con‐
tained in that directory (where "/" is the file-separa‐
tor character, File.separatorChar). A path name that
ends with "/-" indicates all files and subdirectories
contained in that directory (recursively). A path name
consisting of the special token "<<ALL FILES>>" matches
any file.
Note: A path name consisting of a single "*" indicates
all the files in the current directory, while a path
name consisting of a single "-" indicates all the files
in the current directory and (recursively) all files
and subdirectories contained in the current directory.
ExecOptionPermission
The ExecOptionPermission class represents permission
for rmid to use a specific command-line option when
launching an activation group. The name of an ExecOp‐
tionPermission is the value of a command line option.
Syntax
Options support a limited wildcard scheme. An asterisk
signifies a wildcard match, and it may appear as the
option name itself (that is, it matches any option), or
an asterisk may appear at the end of the option name
only if the asterisk follows either a "." or "=".
For example: "*" or "-Dfoo.*" or "-Da.b.c=*" is valid;
"*foo" or "-Da*b" or "ab*" is not.
Policy file for rmid
When granting rmid permission to execute various commands and
options, the permissions ExecPermission and ExecOptionPermis‐
sion need to be granted universally (that is, granted to all
code sources). It is safe to grant these permissions univer‐
sally because only rmid checks these permissions.
An example policy file that grants various execute permissions
to rmid is:
grant {
permission com.sun.rmi.rmid.ExecPermission
"/files/apps/java/jdk1.2.2/bin/java";
permission com.sun.rmi.rmid.ExecPermission
"/files/apps/rmidcmds/*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.policy=/files/policies/group.policy";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Djava.security.debug=*";
permission com.sun.rmi.rmid.ExecOptionPermission
"-Dsun.rmi.*";
};
The first permission granted allow rmid to execute the 1.2.2
version of the java command, specified by its explicit path
names. Note that by default, the version of the java command
found in java.home is used (the same one that rmid uses), and
does not need to be specified in the policy file. The third
permission allows rmid to execute any command in the directory
/files/apps/rmidcmds.
The fourth permission granted, an ExecOptionPermission, allows
rmid to launch an activation group that defines the security
policy file to be /files/policies/group.policy. The next per‐
mission allows the java.security.debug property to be used by
an activation group. The last permission allows any property
in the sun.rmi property name hierarchy to be used by activa‐
tion groups.
To start rmid with a policy file, the java.security.policy
property needs to be specified on rmid's command line. For
example:
rmid -J-Djava.security.policy=rmid.policy
· policyClassName
If the default behavior is not flexible enough, an administra‐
tor can provide, when starting rmid, the name of a class whose
checkExecCommand method is executed in order to check commands
to be executed by rmid.
The policyClassName specifies a public class with a public,
no-argument constructor and an implementation of the following
checkExecCommand method:
public void checkExecCommand(ActivationGroupDesc desc,
String[] command)
throws SecurityException;
Before launching an activation group, rmid calls the policy's
checkExecCommand method, passing it the activation group
descriptor and an array containing the complete command to
launch the activation group. If the checkExecCommand throws a
SecurityException, rmid will not launch the activation group
and an ActivationException will be thrown to the caller
attempting to activate the object.
· none
If the sun.rmi.activation.execPolicy property value is "none",
then rmid will not perform any validation of commands to
launch activation groups.
-log dir
Specifies the name of the directory the activation system daemon
uses to write its database and associated information. The log
directory defaults to creating a directory, log, in the direc‐
tory in which the rmid command was executed.
-port port
Specifies the port rmid's registry uses. The activation system
daemon binds the ActivationSystem, with the name java.rmi.acti‐
vation.ActivationSystem, in this registry. Thus, the Activa‐
tionSystem on the local machine can be obtained using the fol‐
lowing Naming.lookup method call:
import java.rmi.*;
import java.rmi.activation.*;
ActivationSystem system;
system = (ActivationSystem)
Naming.lookup("//:port/java.rmi.activation.ActivationSystem");
-stop Stops the current invocation of rmid, for a port specified by
the -port option. If no port is specified, it will stop the
rmid running on port 1098.
ENVIRONMENT VARIABLES
CLASSPATH Used to provide the system a path to user-defined
classes. Directories are separated by colons. For
example,
example% .:/usr/local/java/classes
SEE ALSOrmic(1)
See (or search java.sun.com) for the following:
RMI Specification @
http://java.sun.com/j2se/1.5/docs/guide/rmi/spec/rmiTOC.doc.html
10 March 2001 rmid(1)
