<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"
http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv=Content-Type content="text/html; charset=utf8">
<title>/usr/web/sources/contrib/maht/newns.c - Plan 9 from Bell Labs</title>
<!-- THIS FILE IS AUTOMATICALLY GENERATED. -->
<!-- EDIT sources.tr INSTEAD. -->
</meta>
</head>
<body>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<p style="line-height: 1.2em; margin-left: 1.00in; text-indent: 0.00in; margin-right: 1.00in; margin-top: 0; margin-bottom: 0; text-align: center;">
<span style="font-size: 10pt"><a href="/plan9/">Plan 9 from Bell Labs</a>’s /usr/web/sources/contrib/maht/newns.c</span></p>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<center><font size=-1>
Copyright © 2009 Alcatel-Lucent.<br />
Distributed under the
<a href="/plan9/license.html">Lucent Public License version 1.02</a>.
<br />
<a href="/plan9/download.html">Download the Plan 9 distribution.</a>
</font>
</center>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<table width="100%" cellspacing=0 border=0><tr><td align="center">
<table cellspacing=0 cellpadding=5 bgcolor="#eeeeff"><tr><td align="left">
<pre>
<!-- END HEADER -->
/*
newns : This program follows the same sequence as ip/httpd/httpd to create a new namespace from /lib/namespace and then add any actions supplied on the command line.
Primarily this is as a debugging tool for ip/httpd/httpd and a little bit of curiosity. Once I'd come across newns(2) I immediately tried to run it from the cmd line so I figured that was a niche because I had no idea how to run a shell that didn't inherit a namespace.
8c newns.c && 8l newns.8 && mv 8.out newns
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
static char *nsfile;
static char *user;
void
usage(void)
{
fprint(2, "usage: newns [-u user] [-a nsfile] \n");
exits("usage");
}
void
change_user(void) {
int fd;
if(user != nil) {
fd = open("#c/user", OWRITE);
if(fd < 0 || write(fd, user, strlen(user)) < 0)
sysfatal("can't become user");
close(fd);
}
}
void
main(int argc, char **argv)
{
int fd;
nsfile = nil;
user = nil;
ARGBEGIN{
case 'a':
nsfile = ARGF();
break;
case 'u':
user = ARGF();
break;
}ARGEND
if(argc)
usage();
if(user)
change_user();
else
user = getuser();
switch(rfork(RFFDG|RFNOWAIT|RFNAMEG|RFPROC)) {
case -1:
sysfatal("fork");
case 0:
break;
default:
exits(nil);
}
if(newns(user, nil) < 0)
sysfatal("newns failed on /lib/namespace");
if(nsfile != nil && addns(user, nsfile) < 0)
sysfatal("addns failed on nsfile");
execl("/bin/rc", "rc");
}
<!-- BEGIN TAIL -->
</pre>
</td></tr></table>
</td></tr></table>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<p style="line-height: 1.2em; margin-left: 1.00in; text-indent: 0.00in; margin-right: 1.00in; margin-top: 0; margin-bottom: 0; text-align: center;">
<span style="font-size: 10pt"></span></p>
<p style="margin-top: 0; margin-bottom: 0.50in"></p>
<p style="margin-top: 0; margin-bottom: 0.33in"></p>
<center><table border="0"><tr>
<td valign="middle"><a href="
http://www.alcatel-lucent.com/"><img border="0" src="/plan9/img/logo_ft.gif" alt="Bell Labs" />
</a></td>
<td valign="middle"><a href="
http://www.opensource.org"><img border="0" alt="OSI certified" src="/plan9/img/osi-certified-60x50.gif" />
</a></td>
<td><img style="padding-right: 45px;" alt="Powered by Plan 9" src="/plan9/img/power36.gif" />
</td>
</tr></table></center>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<center>
<span style="font-size: 10pt">(<a href="/plan9/">Return to Plan 9 Home Page</a>)</span>
</center>
<p style="margin-top: 0; margin-bottom: 0.17in"></p>
<center><font size=-1>
<span style="font-size: 10pt"><a href="
http://www.lucent.com/copyright.html">Copyright</a></span>
<span style="font-size: 10pt">© 2009 Alcatel-Lucent.</span>
<span style="font-size: 10pt">All Rights Reserved.</span>
<br />
<span style="font-size: 10pt">Comments to</span>
<span style="font-size: 10pt"><a href="mailto:
[email protected]">
[email protected]</a>.</span>
</font></center>
</body>
</html>