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

     mach_init -- Mach service naming (bootstrap) daemon

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

     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 sub-
     sets, and associate services with declared servers.  The mach_init daemon
     will also be responsible for launching (and/or re-launching) those ser-
     vice 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 initial-
             ization so that it doesn't have to be put in the background manu-
             ally by the caller.

     -r      Using the -r option tells mach_init to register itself in a pre-
             viously 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 robust-
             ness 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 associ-
     ated 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 tradi-
     tional BSD process control initialization daemon (/sbin/init).

     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-

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


Mac OS X                        March 20, 2002                        Mac OS X