jammy (1) umview.1.gz

Provided by: umview_0.8.2-3_amd64 bug

NAME

       umview - User Mode implementation of View-OS

SYNOPSIS

       umview [ options ] prog

DESCRIPTION

       The  main  goal of the View-OS project is to give each process its own view of the system resources.  For
       example, each process can mount filesystems or hide some file or directories.  It  is  also  possible  to
       assign  virtual  network  interfaces,  IP  addresses  or  define virtual devices for each process (or for
       hierarchies of processes).
       umview is the user mode implementation of View-OS concepts.  It is a  modular  partial  virtual  machine.
       umview  before  loading any module is completely transparent, a process behaves inside umview as it would
       have behaved outside.   Each  module  can  customize  specific  entities:  there  are  modules  to  mount
       filesystems  at  user-level  (umfuse) , to define virtual network interfaces (lwipv6) , to define virtual
       devices (umdev) , to provide interpreters for  executables,  e.g.  to  support  executables  for  foreign
       architectures (umbinfmt) , to hide, move, overlay parts of the file system (viewfs).
       These  are  some  examples  of  modules  provided  by the View-OS team.  umview aims to provide a general
       interface to customize the system call semantics of process under specified conditions. So  more  modules
       will be added both by the View-OS team and by third parties.

OPTIONS

       -V name
       --viewname name
           set the name of the view. The view can be read and set using vuname or viewname commands.
       -p module [ , module_options ]
       --preload module [ , module_options ]
           preload  modules.   Modules  will  be loaded as shared libraries thus all the rules to load libraries
           apply. Modules must be loaded from a directory within the ld.so search path or should be specified by
           their  pathnames.   If  necessary  configure  the LD_LIBRARY_PATH environment variable appropriately.
           module_options are module specific configuration options,  thus  the  reader  should  refer  to  each
           service  module  manual  for  a  complete  description.   Modules can be loaded at run time using the
           um_add_service command.
       -s
       --secure
           set kmview in human mode, i.e. force the check of capabilities and permissions. uid is 0 at  startup,
           in  this  way  it  is  possible to load modules and mount services. When a process sets its uid as an
           unprivileged user (via setuid(2) or viewsu(1)), capability and permissions are enforced.
       -f rcfile
       --rc rcfile
           Use rcfile as the initialization file for kmview.  kmview always executes  /etc/viewosrc  if  exists,
           then kmview executes the initialization file set by this option or ~/.viewosrc.
       -x
       --nonesting
           umview  is able to provide module nesting, i.e. a module can provide services on the basis of virtual
           services provided by another module or even by the module itself. For example it is possible to mount
           a  file  system  image  which  is  stored  in  an already virtually mounted filesystem.  This feature
           requires the pure_libc library.  The -x or --nonesting option disables the nesting feature.
       -n
       --nokernelpatch
           umview is able to use some specific kernel extensions (when present) to increase its performance. The
           source  distribution  of  umview  include  the  kernel  patches  for  the latest kernels.  The kernel
           extensions are enabled by default when available.  This option disables the kernel extensions.
       --nokmulti
           This option disables the PTRACE_MULTI kernel extension.
       --noksysvm
           This option disables the PTRACE_SYSVM kernel extension.
       --nokviewos
           This option disables the PTRACE_SYSVIEWOS kernel extension (already experimental, not yet released).
       -o file
       --output file
           This option diverts the debugging output to the file specified, it is useful  when  umview  has  been
           compiled with debugging extensions.
       -v
       --version
           Print the version and exit.
       -h
       --help
           Print a short help message and exit.

SEE ALSO

       um_add_service(1)  um_del_service(1)  um_ls_service(1)  um_mov_service(1) umfuse(1viewos) lwipv6(1viewos)
       umdev(1viewos) umbinfmt(1viewos) viewfs(1viewos) vuname(1viewos) viewname(1viewos)

AUTHORS

       View-OS is a project of the Computer Science Department, University of  Bologna.  Project  Leader:  Renzo
       Davoli.  Development  Team: P. Angelelli, A.  Bacchelli, M. Belletti, P. Beverini, D. Billi, A. Forni, L.
       Gardenghi,      A.      Gasparini,      D.      Lacamera,      C.      Martellini,      A.      Seraghiti
       <http://www.sourceforge.net/projects/view-os>

       Howto's and further information can be found on the project wiki <wiki.virtualsquare.org>.