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
Check Out this Related Man Page
RUMP_SERVER(1) BSD General Commands Manual RUMP_SERVER(1)NAME
rump_server, rump_allserver -- rump kernel server
SYNOPSIS
rump_server [-s] [-c ncpu] [-d drivespec] [-l library] [-m module] url
DESCRIPTION
The rump_server utility is used to provide a rump kernel service. Clients can use the system calls provided by rump_server via url.
The difference between rump_server and rump_allserver is that rump_server offers only a minimalistic set of features, while rump_allserver
provides all rump kernel components which were available when the system was built. At execution time it is possible to load components from
the command line as described in the options section.
-c ncpu
Configure ncpu virtual CPUs on SMP-capable archs. By default, the number of CPUs equals the number of CPUs on the host.
-d drivespec
The argument drivespec maps a host file in the rump fs namespace. The string drivespec must be of comma-separated ``name=value''
format and must contain the following tokens:
key Block device path in rump namespace. This must be specified according to the rules for a key in rump_etfs(3).
hostpath Host file used for storage. If the file does not exist, it will be created.
size Size of the mapping. Similar to dd(1), this argument accepts a suffix as the multiplier for the number. The special
value ``host'' indicates that the current size of hostpath will be used. In this case it is assumed that hostpath
exists and is a regular file.
OR
disklabel Use a disklabel partition identifier to specify the offset and size of the mapping. hostpath must contain an existing
and valid disklabel within the first 64k.
The following are optional:
offset Offset of the mapping. The window into hostpath therefore is [offset, offset+size]. In case this parameter is not
given, the default value 0 is used.
type The type of file that key is exposed as within the rump kernel. The possibilities are ``blk'', ``chr'', and ``reg''
for block device, character device and regular file, respectively. The default is a block device.
Note: the contents of block devices are cached in the rump kernel's buffer cache. To avoid cache incoherency, it is
advisable not to access a file through the host namespace while it is mapped as a block device in a rump kernel.
In case hostpath does not exist, it will be created as a regular file with mode 0644 (plus any restrictions placed by umask). In
case hostpath is a regular file and is not large enough to accommodate the specified size, it will be extended to the specified size.
-l library
Call dlopen() on library before initializing the rump kernel. In case library provides a kernel module, it will appear as a builtin
module in the rump kernel. Any rump component present in library will also be initialized.
The argument library can contain a full path or a filename, in which case the standard dynamic library search path will be used.
Libraries are loaded in the order they are given. Dependencies are not autoloaded, and the order must be specified correctly.
-m module
Load and link a kernel module after the rump kernel is initialized. For this to work, the rump kernel must include the vfs faction,
since the module is loaded using kernel vfs code (see EXAMPLES).
-r total_ram
Sets the limit of kernel memory allocatable by the server to total_ram as opposed to the default which allows the server to allocate
as much memory as the host will give it. This parameter is especially useful for VFS servers, since by default the virtual file sys-
tem will attempt to consume as much memory as it can, and accessing large files can cause an excessive amount of memory to be used as
file system cache.
-s Do not detach from the terminal. By default, rump_server detaches from the terminal once the service is running on url.
-v Set bootverbose.
After use, rump_server can be made to exit using rump.halt(1).
EXAMPLES
Start a server and load the tmpfs file system module, and halt the server immediately afterwards:
$ rump_server -lrumpvfs -m /modules/tmpfs.kmod unix://sock
$ env RUMP_SERVER=unix://sock rump.halt
Start a server with the one gigabyte host file dk.img mapped as the block device /dev/dk in the rump kernel.
$ rump_allserver -d key=/dev/dk,hostpath=dk.img,size=1g unix://sock
Start a server which listens on INADDR_ANY port 3755
$ rump_server tcp://0:3755/
Start a FFS server with a 16MB kernel memory limit.
$ rump_server -lrumpvfs -lrumpfs_ffs -r 16m unix:///tmp/ffs_server
SEE ALSO rump.halt(1), dlopen(3), rump(3), rump_sp(7)BSD February 21, 2011 BSD