.\" Copyright (c) 2007 Renzo Davoli
.\"
.\" mstack manual page
.\"
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.TH VIEW-OS 1 "April 23, 2008" "VIEW-OS: a process with a view"
.SH NAME
mstack \- networking stack selection
.SH SYNOPSIS
.B mstack
[\fI-hv\fR]
[\fI-o\fR protocol list]
\fIstack_mountpoint\fR \fIcommand\fI
.br
.SH DESCRIPTION
.PP
In View-OS multiple networking stacks are available to processes
at the same time. View-OS supports the \fBmsocket(2)\fR system call.
mstack defines the default stack (for each address family) that is used
when msocket refers to a NULL pathname for its stack.
mstack provides also a backward compatibility for all the programs
using the obsolete \fBsocket(2)\fR system call.
The stack mountpoint identifies the stack. In ViewOS it is the mountpoint
where the stack was mounted (by \fBmount(2)(8)\fR.
In fact the call:
.br
"socket(domain,type,protocol)" 
.br
is equivalent to:
.br
"msocket(NULL,domain,type protocol)" 
.br
mstacks changes the default stack for the desired protocol families and
executes the command (by \fBexecve(2)).
.SH OPTIONS
.IP "\fB\-h\fR" 4
prints the mstack command usage
.IP "\fB\-v\fR" 4
sets the verbose mode on
.IP "\fB\-o\fR" 4
defines the list of protocols. Without a -o option, 
mstack redefines the default stack for all protocols families.
The list of protocols may include the a comma separated sequence of the 
following items:
all, unix (or simply u), ipv4 (4), ipv6 (6), netlink (n), packet (p),
bluetooth (b), irda (i), ip (which include all ip related protocols
ipv4, ipv6, netlink and packet), #\fIn\fR where n is the number of protocol.
Each item can be prefixed by + or - to specify whether the protocol/group
of protocols must be added or removed from the set.
.SH EXAMPLES
.IP "\fBmstack /dev/net/lwip ip addr\fR"
.br
lists the address managed by the stack mounted on \fB/dev/net/lwip\fR.
.IP "\fBexec mstack /dev/net/null bash\fR"
.br
disables the standard stack in a new bash (which overcomes the current one).
.IP "\fBmstack -o ip /dev/net/lwip bash\fR"
.br
starts a new bash which uses the stack \fB/dev/net/lwip\fR for ipv4 and ipv6
but not for the other protocols.
.IP "\fBmstack -o -unix /dev/net/lwip bash\fR"
.br
starts a new bash which uses the stack \fB/dev/net/lwip\fR for all protocols
but AF_UNIX.
.IP "\fBmstack -o +ip,-ipv6 /dev/net/lwip bash\fR"
.br
starts a new bash which uses the stack \fB/dev/net/lwip\fR for ipv4, netlink,
packet but not ipv6.
.SH SEE ALSO
.BR umview(1), 
.BR	kmview(1), 
.BR	msocket(3), 
.BR umnetnative(9),
.BR umnetnull(9),
.BR umnetlwipv6(9),
.BR	unix(7), 
.BR	ip(7), 
.BR	ipv6(7), 
.BR	netlink(7), 
.BR	packet(7).
.SH AUTHORS
View-OS is a project of the Computer Science Department, University of
Bologna. Project Leader: Renzo Davoli. 
.br
<http://www.sourceforge.net/projects/view-os>

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