opendarwin man page for mach_init

MACH_INIT(8)						    BSD System Manager's Manual 					      MACH_INIT(8)

NAME
     mach_init -- Mach service naming (bootstrap) daemon

SYNOPSIS
     mach_init [-D] [-d] [-F] [-r name-in-existing-server]

DESCRIPTION
     mach_init is a daemon that maintains various mappings between service names and the Mach ports that provide access to those services.
     Clients of mach_init can register and lookup services, create new mapping subsets, and associate services with declared servers.  The
     mach_init daemon will also be responsible for launching (and/or re-launching) those service providing servers when attempts to use one or
     more of the associated services is detected.

     The options are as follows:

     -D      When the -D option is specified, mach_init starts in normal (non-debug) mode.  Logging is minimal (only security-related and process
	     launch failures are logged).  Core dumps are disabled for launched servers.  This is the default.

     -d      When the -d option is specified, mach_init starts in debug mode. Logging is extensive.  Core dumps will be taken for any launched
	     servers that crash.

     -F      When the -F option is specified, mach_init forks during initialization so that it doesn't have to be put in the background manually
	     by the caller.

     -r      Using the -r option tells mach_init to register itself in a previously running copy of mach_init under the service name
	     name-in-existing-server. This is most useful when debugging new instances of mach_init itself, but can also be used for robustness or
	     to allow the subsequent mach_init processes to run as a non-root user.  As mach_init is often used to launch servers, this could be
	     more secure.  However, mach_init will not allow a server declaration to specify a user id different than that of the requesting
	     client (unless the client is running as root).  So it shouldn't be required for a secure configuration.

     Access to mach_init is provided through the bootstrap series of RPC APIs over service ports published by mach_init itself. Each Mach task has
     an assigned bootstrap port retrieved via task_get_bootstrap_port().  These bootstrap port registrations are inherited across fork().

     The service registrations are grouped into subsets, providing a level of security. Only processes with access to the subset's bootstrap port
     will be able to register/lookup Mach ports within that subset.  Lookups from within a subset will search the subset first, then move on to
     its parent, and then its grand-parent, etc... until a string name match is found or the top of the bootstrap tree is reached.  Subsets are
     sometimes associated with login sessions to protect session-specific ports from being exposed outside the session.

     The first instance of mach_init is responsible for launching the traditional BSD process control initialization daemon (/sbin/init).

SAMPLE USAGE
     mach_init -d -r com.company.bootstrap

     mach_init will start in debug mode, and register itself in an already running instance of mach_init under the service name com.company.boot-
     strap.

NOTE
     Sending a SIGHUP to a running mach_init will toggle debug mode.

SEE ALSO
     init(8)

Mac OS X							  March 20, 2002							  Mac OS X