RUMP_SP(7)					       BSD Miscellaneous Information Manual						RUMP_SP(7)

NAME

     rump_sp -- rump remote system call support

DESCRIPTION

     The rump_sp facility allows clients to attach to a rump kernel server over a socket and perform system calls.  While making a local rump sys-
     tem call is faster than calling the host kernel, a remote system call over a socket is slower.  This facility is therefore meant mostly for
     operations which are not performance critical, such as configuration of a rump kernel server.

   Clients
     The NetBSD base system comes with multiple preinstalled clients which can be used to configure a rump kernel and request diagnostic informa-
     tion.  These clients run as hybrids partially in the host system and partially against the rump kernel.  For example, network-related clients
     will typically avoid making any file system related system calls against the rump kernel, since it is not guaranteed that a rump network
     server has file system support.  Another example is DNS: since a rump server very rarely has a DNS service configured, host networking is
     used to do DNS lookups.

     Some examples of clients include rump.ifconfig which configures interfaces, rump.sysctl which is used to access the sysctl(7) namespace and
     rump.traceroute which is used to display a network trace starting from the rump kernel.

     Also, almost any unmodified dynamically linked application (for example telnet(1) or ls(1)) can be used as a rump kernel client with the help
     of system call hijacking.	See rumphijack(3) for more information.

   Connecting to the server
     A remote rump server is specified using an URL.  Currently two types of URLs are supported: TCP and local domain sockets.	The TCP URL is of
     the format tcp://ip.address:port/ and the local domain URL is unix://path.  The latter can accept relative or absolute paths.  Note that
     absolute paths require three leading slashes.

     To preserve the standard usage of the rump clients' counterparts the environment variable RUMP_SERVER is used to specify the server URL.  To
     keep track of which rump kernel the current shell is using, modifying the shell prompt is recommended -- this is analoguous to the visual
     clue you have when you login from one machine to another.

   Client credentials and access control
     The current scheme gives all connecting clients root credentials.	It is recommended to take precautions which prevent unauthorized access.
     For a unix domain socket it is enough to prevent access to the socket using file system permissions.  For TCP/IP sockets the only available
     means is to prevent network access to the socket with the use of firewalls.  More fine-grained access control based on cryptographic creden-
     tials may be implemented at a future date.

EXAMPLES

     Get a list of file systems supported by a rump kernel server (in case that particular server does not support file systems, an error will be
     returned):

	   $ env RUMP_SERVER=unix://sock rump.sysctl vfs.generic.fstypes

SEE ALSO

     rump_server(1), rump(3), rumpclient(3), rumphijack(3)

HISTORY

     rump_sp first appeared in NetBSD 6.0.

BSD
								 February 7, 2011							       BSD