Installing the Inferno Software

Vita Nuova

12 June 2003

Inferno can run as either a native operating system, in the usual way, or as a hosted virtual operating system, running as an application on another operating system. This paper explains how to install Inferno from the distribution media to a hosted environment and how to configure the system for basic networking.

Inferno can run as a hosted virtual operating system on top of Plan 9, Unix or Windows. In this paper, the term Unix is used to cover all supported variants, currently FreeBSD, Linux, HP/UX, Irix and Solaris, and the term Windows covers Microsoft Windows (98, Me, Nt, 2000, and XP). (Windows 98 might first require installation of the Unicode layer update from Microsoft.)

1. Preparation

You should ensure at least 150 Mbytes of free space on the filesystem. The installation program will copy files from the distribution CD to a directory on the filesystem called the inferno_root directory. You can choose the location of this directory. If you are installing to a multiuser filesystem outside your control a subdirectory of your home directory might be most sensible. If you plan to share the Inferno system with other users then common choices for inferno_root are /usr/inferno on Unix and Plan 9 systems, and c:\inferno on Windows systems. Where these appear in examples in this paper you should substitute your own inferno_root directory.

• Step 1ab: Choose the inferno_root directory.

Ensure that the user who will run the installation program has appropriate filesystem permissions to create the inferno_root directory and files and subdirectories beneath it.

2. Copying Files

On all platforms the files will be owned by the user doing the installation, except for installation onto a FAT file system (eg, on Windows), where the files appear to be owned by Everyone because FAT does not record ownership.

• Step 2ab: Insert the distribution CD into the CD drive.

On Unix and Plan 9, mount the CD to a suitable location on the filesystem, call this location cd_path. On Windows, note the drive letter of the CD, call this drive letter cd_drive. The files will be copied by an Inferno hosted installation program which runs directly from the CD. The directory /install on the CD contains an installation program for each supported platform - a shell script for Unix and Plan 9 and an executable for Windows. The Plan 9 install script is called Plan9.rc and determines the CPU type from the environment variable cputype. The Unix install scripts all have names of the form where host_os will be one of: FreeBSD, Linux, or Solaris and host_arch will be one of: 386, mips, power or sparc. Most platforms offer just the one obvious combination. The Windows installation program is called setup.exe; it is used on all varieties of Windows. The next step describes how to begin the installation by running the program that corresponds to your host system.

• Step 2ac: Run the installation script.

The installation program will copy files from the CD to the filesystem. The Windows installation program will also create registry entries and add an Inferno item to the Windows start menu. On Plan 9, run

rc cd_path/install/Plan9.rc inferno_root

Where inferno_root is the path to the chosen Inferno root directory. The CPU architecture will be inferred from the environment variable cputype. On Unix, run

sh cd_path/install/  inferno_root

Where host_os is the Unix variant name (FreeBSD, Irix, Linux or Solaris). host_arch is the CPU type (eg, 386), and inferno_root is the path to the chosen Inferno directory. On Windows, run


The Windows installation program will ask you to choose the location of the installation directory on the hard disk.

On all platforms, a copy of Inferno on the CD will install from various installation packages on the CD to the inferno_root subtree on the filesystem. On any platform it installs support for all.

Inferno is now installed, but it needs to be configured for your site. The process acts as a quick tour of parts of the system. The main tasks are to add local parameters to the network data base, and to set up the authentication system. If you are going to run Inferno standalone, for instance to experiment with Limbo and the file serving interface, most of what follows can be deferred indefinitely. It is still worthwhile skimming through it, because the first few sections tell how to start up Inferno with correct parameters (eg, root directory and graphics resolution). (A configuration program that runs under the window system would be more convenient, and fairly easy to do, but that has not yet been done.)

3. Running Inferno

Inferno host executables are all kept in a single directory corresponding to the combination of host operating system and CPU architecture - the Inferno bin directory.


(On Windows the path might need \ not / of course.) That directory can be added to the search path of the host system’s command interpreter, and that process will be described first, although as discussed later one can use a script instead and that is sometimes more convenient. (Of course, the script will still need to refer to that directory.)

Plan 9:   Plan 9 users should add a line to their lib/profile file that binds this directory after their /bin directory.

bind -a /usr/inferno/Plan9/$cputype/bin /bin

The bind is done after the existing bin directory to avoid hiding the existing Plan 9 compilers. If, at a later stage, you build either the hosted or native Inferno kernels for ARM or StrongARM you should ensure that the Inferno compilers are used rather than the Plan 9 compilers, since they differ in the implementation of floating-point instructions (the Plan 9 ARM suite uses a byte order that is more plausible than the order ARM dictates but therefore wrong). That difference is likely to be resolved at some point but it has not yet been done.

The host_os is always Nt (even for Windows 98, 2000 or XP) and host_arch is always 386 and the installation program will create an entry on the start menu to invoke Inferno. For Unix systems or Windows systems in which Inferno will be started from a command shell, the environment variable PATH should be set to include the Inferno bin directory. For Windows 95 and Windows 98 this should be done in the \autoexec.bat file by adding a line like


You will need to reboot Windows to have the system reread the \autoexec.bat file. For Windows NT and Windows 2000 modify the Path environment variable through Control Panel -> System -> Environment.

If you are using an MKS or Cygwin Unix-like shell environment, you might instead set:


and export it if necessary.

For Unix systems, for sh derivatives, the environment variable PATH should be set to include the Inferno bin directory. This might be done in your .profile file by adding a line like


Don’t forget to ensure that PATH is exported. You may need to log out and back in again for the changes to take effect.

• Step 3ab: Start Inferno.

Hosted inferno is run by invoking an executable called emu.

On Windows, select the Inferno option from the start menu. This will invoke emu with appropriate arguments to find its files in inferno_root. If you need to change any of the options passed to emu when invoked from the start menu you need to do this by clicking the right mouse button on the Windows task bar and choosing Properties -> Start Menu Programs -> Advanced to modify the shortcut used for Inferno. For Unix and Plan 9, you will need to tell emu where to find the Inferno file tree by passing it the -rrootpath command line option. For example

emu -r/usr/john/inferno

Without the -r option it will look for the file tree in /usr/inferno on Plan 9 and Unix and, when invoked from the command line on WIndows, the default is \inferno on the current drive. (The Windows start menu by contrast has already been set to use the right directory by the installation software.)

When using graphics, emu will use a window with a resolution of 640 x 480 pixels by default. To use a larger resolution you will need to pass emu an option -gXsizexYsize on the command line. So, for example, to invoke emu as above but with a resolution of 1024 x 768 pixels the full command line would be

emu -r/usr/john/inferno -g1024x768

When invoked in this way emu displays a command window running the Inferno shell /dis/sh.dis. To avoid typing the command line options each time you invoke emu you can store them in the environment variable EMU which is interrogated when emu is started and might as well be set along side the PATH environment variable if the same configuration options are to be used on each invocation.

set EMU="-rd:\Documents and Settings\john\inferno -g1024x768"

for Windows.

EMU=(-r/usr/john/inferno -g1024x768)

for Plan 9, and

EMU="-r/usr/john/inferno -g1024x768"

for Unix. An alternative to using the EMU environment variable is to place the correct invocation in a script file (or batch file, for Windows) and invoke that instead of running emu directly. It is important to note that for Windows the -r option also serves to indicate both the drive and directory on to which the software has been installed. Without a drive letter the system will assume the current drive and will fail if the user changes to an alternative drive. Once the environment variables or scripts are set up, as described above, invoking plain


or the appropriate script file, should result in it starting up Inferno’s command interpreter sh(1), which prompts with a semicolon:

You can add a further option -c1 to start up emu in a mode in which the system compiles a module’s Dis operations to native machine instructions when a module is loaded. (See the emu(1) manual page.) In compile mode programs that do significant computation will run much faster. Whether in compiled or interpreted mode you should now have a functional hosted Inferno system. When Inferno starts the initial /dis/sh.dis it reads commands from the file /lib/sh/profile before becoming interactive. See the manual pages for the shell sh(1) to learn more about tailoring the initial environment.

The semicolon is the default shell prompt. From this command window you should be able to see the installed Inferno files and directories

lc /

The command lc presents the contents of its directory argument in columnar fashion to standard output in the command window.

; lc /

FreeBSD/     Unixware/    icons/       libkern/     man/         prof/

Hp/          acme/        include/     libkeyring/  mkconfig     prog/

Inferno/     appl/        keydb/       libmath/     mkfile       services/

Irix/        asm/         legal/       libmemdraw/  mkfiles/     tmp/

LICENCE      chan/        lib/         libmemlayer/ mnt/         tools/

Linux/       dev/         lib9/        libtk/       module/      usr/

MacOSX/      dis/         libbio/      licencedb/   n/           utils/

NOTICE       doc/         libcrypt/    limbo/       net/         wrap/

Nt/          emu/         libdraw/     locale/      nvfs/

Plan9/       env/         libfreetype/ mail/        o/

Solaris/     fonts/       libinterp/    os/


Only the files and directories in and below the inferno_root directory on the host filesystem are immediately visible to an Inferno process; these files are made visible in the root of the Inferno file namespace. If you wish to import or export files from and to the host filesystem you will need to use tools on your host to move them in or out of the Inferno visible portion of your host filesystem (see the manual pages os(1) and cmd(3) for an interface to host commands). (We plan to make such access direct, but the details are still being worked out.) From this point onwards in this paper all file paths not qualified with inferno_root are assumed to be in the Inferno namespace. Files created in the host filesystem will be created with the user id of the user that started emu and on Unix systems with that user’s group id.

4. Setting the site’s time zone

Time zone settings are defined by files in the directory /locale/timezone. The setting affects only how the time is displayed; the internal representation does not vary. For instance, the file /locale/GMT defines Greenwich Mean Time, /locale/GB-Eire defines time zones for Great Britain and the Irish Republic (GMT and British Summer Time), and /locale/US_Eastern defines United States Eastern Standard Time and Eastern Daylight Time. The time zone settings used by applications are read (by daytime(2)) from the file /locale/timezone, which is initially a copy of /locale/GB-Eire. If displaying time as the time in London is adequate, you need change nothing. To set a different time zone for the whole site, copy the appropriate time zone file into /locale/timezone:

cp /locale/US_Eastern /locale/timezone

To set a different time zone for a user or window, bind(1) the file containing the time zone setting over /locale/timezone, either in the user’s profile or in a name space description file:

bind /locale/US_Eastern /locale/timezone

5. Running the Window Manager wm

Graphical Inferno programs normally run under the window manager wm(1). Inferno has a simple editor, wm/edit, that can be used to edit the inferno configuration files. The ‘power environment’ for editing and program development is acme(1), but rather that throwing you in at the deep end, we shall stick to the simpler one for now. If you already know Acme from Plan 9, however, or perhaps Wily from Unix, feel free to use Inferno’s acme instead of edit.

• Step 5ab: Start the window manager.

Invoke wm by typing


You should see a new window open with a blue-grey background and a small Vita Nuova logo in the bottom left hand corner. Click on the logo with mouse button 1 to reveal a small menu. Selecting the Edit entry will start wm/edit. In common with most wm programs the editor has three small buttons in a line at its top right hand corner. Clicking on the X button, the rightmost button, will close the program down. The leftmost of the three buttons will allow the window to be resized - after clicking it drag the window from a point near to either one of its edges or one of its corners. The middle button will minimise the window, creating an entry for it in the application bar along the bottom of the main wm window. You can restore a minimised window by clicking on its entry in the application bar. The initial wm configuration is determined by the contents of the shell script /lib/wmsetup (see toolbar(1) and sh(1)).

• Step 5ac: Open a shell window.

Choose the shell option from the menu to open up a shell window. The configuration of Inferno will be done from this shell window.

6. Manual Pages

Manual pages for all of the system commands are available from a shell window. Use the man or wm/man commands. For example,

man wm

will give information about wm. And

man man

will give information about using man. Wm/man makes use of the Tk text widget to produce slightly more attractive output than the plain command man. Here, and in other Inferno documentation you will see references to manual page entries of the form command(section). You can display the manual page for the command by running

man command


man section command

if the manual page appears in more than one section.

7. Initial Namespace

The initial Inferno namespace is built by placing the root device ’#/’ (see root(3)) at the root of the namespace and binding

i) the host filesystem device ’#U’ (see fs(3)) containing the inferno_root subtree of the host filesystem at the root of the Inferno filesystem,

ii) the console device ’#c’ (see cons(3)) in /dev,

iii) the prog device ’#p’ (see prog(3)) onto /prog,

iv) the IP device ’#I’ (see ip(3)) in /net, and

v) the environment device ’#e’ (see env(3)) at /dev/env.

You can see the sequence of commands required to construct the current namespace by running


8. Inferno’s network

If you are just going to use Inferno for local Limbo programming, and not use its networking interface, you can skip to the section ‘‘Adding new users’’ at the end of this document. You can always come back to this step later.

To use IP networking, the IP device (ip(3)) must have been bound into /net. Typing

ls -l /net

(see ls(1)) should result in something like

--rw-rw-r-- I 0 network john 0 May 31 07:11 /net/arp

--rw-rw-r-- I 0 network john 0 May 31 07:11 /net/ndb

d-r-xr-xr-x I 0 network john 0 May 31 07:11 /net/tcp

d-r-xr-xr-x I 0 network john 0 May 31 07:11 /net/udp

There might be many more names on some systems.

A system running Inferno, whether native or hosted, can by agreement attach to any or all resources that are in the name space of another Inferno system (or even its own). That requires:

• the importing system must know where to find them

• the exporting system must agree to export them

• the two systems must authenticate the access (not all resources will be permitted to all systems or users)

• the conversation can be encrypted to keep it safe from prying eyes and interference

On an Inferno network, there is usually one secure machine that acts as authentication server. All other systems variously play the rôles of server and client as required: any system can import some resources (or none) and export others (or none), simultaneously, and differently in different name spaces. In following sections, we shall write as though there were three distinct machines: authentication server (signer); server (exporting resources); and client (importing resources). With Inferno, you can achieve a similar effect on a single machine by starting up distinct instances of emu instead. That is the easiest way to become familiar with the process (and also avoids having to install the system on several machines to start). It is still worthwhile setting up a secured authentication server later, especially if you are using Windows on a FAT file system where the host system’s file protections are limited.

We shall now configure Inferno to allow each of the functions listed above:

• change the network database to tell where to find local network resources

• set up the authentication system, specifically the authentication server or ‘signer’

• start network services (two distinct sets: one for the authentication services and the other for all other network services)

9. Network database files

In both hosted and native modes, Inferno uses a collection of text files of a particular form to store all details of network and service configuration. When running hosted, Inferno typically gets most of its data from the host operating system, and the database contains mainly Inferno-specific data.

The file /lib/ndb/local is the root of the collection of network database files. The format is defined by ndb(6), but essentially it is a collection of groups of attribute/value pairs of the form attribute=value. Attribute names and most values are case-sensitive.

Related attribute/value pairs are grouped into database ‘entries’. An entry can span one or more lines: the first line starts with a non-blank character, and any subsequent lines in that entry start with white space (blank or tab).

9.1. Site parameters

The version of /lib/ndb/local at time of writing looks like this:







    #dns=    # resolver






The individual files forming the data base are listed in order in the database entry. They can be ignored for the moment. The entry labelled infernosite= defines a mapping from symbolic host names of the form $service to a host name, domain name, or a numeric Internet address. For instance, an application that needs an authentication service will refer to $SIGNER and an Inferno naming service will translate that at run-time to the appropriate network name for that environment. Consequently, the entries above need to be customised for a given site. (The items that are commented out are not needed when the host’s own DNS resolver is used instead of Inferno’s own dns(8).) For example, our infernosite entry in the local file might look something like this


    dns=  # resolver






where doppio is the host name of a machine that is offering the given services to Inferno, and is the Internet address of a local DNS resolver.

• Step 9ab: Enter defaults for your site

The only important names initially are:

SIGNER the host or domain name, or address of the machine that will act as signer

registry the name or address of a machine that provides the local dynamic service registry(4)

FILESERVER the primary file server (actually needed only by clients with no storage of their own)

All others are used by specific applications such as acme(1) mail or ftpfs(4).

If you are using a single machine for signer and server/client, put its name in those three entries.

9.2. Connection server cs(8) and name translation

The connection server cs(8) uses the network database and other data (such as that provided by the host system and the Internet DNS servers) to translate symbolic network names and services into instructions for connecting to a given service. In hosted mode, network and service names are passed through to the host for conversion to numeric IP addresses and port numbers. If the host is unable to convert a service name the connection server will attempt to convert the name using mappings of service and protocol names to Internet port numbers in the file /lib/ndb/inferno:

tcp=infgamelogin port=6660  # inferno games login service

tcp=styx port=6666  # main file service

tcp=mpeg port=6667  # mpeg stream

tcp=rstyx port=6668 # remote invocation

tcp=infdb port=6669 # database server

tcp=infweb port=6670    # inferno web server

tcp=infsigner port=6671 # inferno signing services

tcp=infcsigner port=6672    # inferno countersigner

tcp=inflogin port=6673  # inferno credential service

tcp=infsds port=6674    # software download

tcp=registry port=6675  # registry(4)

udp=virgil port=2202    # naming service

For the moment, leave that file as it is. You will only need to modify this file if in future you add new statically-configured services to Inferno. (Services that come and go dynamically might use registry(4) instead, a registry manager that allows a service to be found using a description of it.)

10. Configuring a Signer

Before an Inferno machine can authenticate establish a secure connection to an Inferno service on another machine, each system needs to obtain a certificate from a common signer.† We talk here as though there is only one ‘signer’ per site but in fact there can be application- or group-specific ones. For instance, a version of the Inferno games server automatically starts its own signing service to keep the identities and keys used for game service separate from those of the primary system, allowing users to set up their own gaming groups without fuss.

To use authenticated connections for the primary file services we need to set up a signer to generate certificates for users (see createsignerkey(8) and logind(8)).

Choose an Inferno machine to become the signer. If this is the first or only Inferno machine on your network then make this machine the signer. (It is more realistic if you start up a separate copy of emu and leave it in ‘console’ mode without starting the window system.) You can always move the function elsewhere later.

• Step 10ab: Empty the secret file of secrets.

The authentication server verifies a user’s identity by checking that the user knows a shared secret. (In fact the secret is not used directly, but instead a scrambled value that was derived from it.) The file /keydb/keys holds those secrets; it is encrypted using a secret password or phrase known only to the manager of the authentication server. Having just installed Inferno, the file should exist and be readable only by you (or the user as which the authentication service will run). On the signer machine, type

ls -l /keydb/keys

You should see something like:

--rw------- M 7772 yourname inf 0 Jun 12 03:08 /keydb/keys

You should see something like the above. If the file does not exist or is not empty or has the wrong mode, use:

cp /dev/null /keydb/keys; chmod 600 /keydb/keys

to set it right.

• Step 10ac: Generate a signer key.

Next on the signer machine, run

auth/createsignerkey name

In place of name enter the network name of the signer. A fully-qualified domain name of a host or individual is fine. This value will appear as the signer name in each certificate generated by the signer. Createsignerkey creates public and private keys that are used by the signer when generating certificates. They are stored in /keydb/signerkey; check that it has permissions that limit access to the user that will run the authentication services:

; ls -l /keydb/signerkey

--rw------- M 32685 secrets inf 1010 Jul 07  2000 /keydb/signerkey

Use chmod(1) to set the mode to read/write only for the owner if necessary:

chmod 600 /keydb/signerkey

• Step 10ad: Start the authentication network services

Still at the signer console, type


That script (see svc(8)) will check that the /keydb/keys and /keydb/signerkey files exist, and then start the program keyfs(4), which manages the keys file. It will prompt for the password (pass phrase) you wish to use to protect the keys file, now and on subsequent runs:

; svc/auth


Confirm key:

It prompts twice to confirm it. If successfully confirmed, it will then start the network services used by Inferno to authenticate local and remote users and hosts. (If confirmation fails, retry by running svc/auth again.)

You can check that they are running by typing:


which should show something like the following:

       1        1    john    release    74K Sh[$Sys]

       3        2    john        alt    15K Cs

      10        9    john       recv    25K Keyfs

      11        9    john    release    44K Styx[$Sys]

      12        9    john       recv    25K Keyfs

      14        1    john        alt     8K Listen

      16        1    john    release     8K Listen[$Sys]

      18        1    john        alt     9K Listen

      20        1    john    release     9K Listen[$Sys]

      22        1    john        alt     9K Listen

      24        1    john    release     9K Listen[$Sys]

      26        1    john        alt     8K Listen

      28        1    john    release     8K Listen[$Sys]

      29        1    john      ready    73K Ps[$Sys]

There should be Keyfs and Listen processes.

• Step 10ae: Enter user names and secrets.

For each user to be authenticated by the signer run

auth/changelogin username

You will be prompted to supply a secret (ie, password or pass phrase) and expiration date. The expiration date will be used as the maximum expiration date of authentication certificates granted to that user. Changelogin (see changelogin(8)) accesses the name space generated by keyfs(4), which has just been started above by svc/auth. A user can later change the stored secret using the passwd(1) command. For the signer to generate a certificate there must be at least one entry in the password file. If you are not sure at this stage of the names of the users that you want to authenticate then create an entry for the user inferno and yourself.

11. Establishing a Secure Connection

To establish a secure connection between two Inferno machines, each needs to present a public key with a certificate signed by a common signer. We shall make two public/private key sets, one for the server and one for a client (they differ only in where they are stored). We shall do the server first, because the usual network services require the server possess some keys before they can start. We shall then start those services, and finally sort out the client.

• Step 11ab: Start the connection service.

The server still needs to make contact with the signer, so we need to start the basic connection service cs(8). If you are using the same instance of emu in which you invoked svc/auth above, you should skip this step. To check, you should see a new file in the /net directory called cs. Run the command

ls /net

You should see at least the following names in the output:





Otherwise, type


That starts cs(8). Try the ls /net again to check that the cs file has appeared.

• Step 11ac: Generate a server key set.

On the server machine (or in the ‘server’ window), use getauthinfo(8) to obtain a certificate and save it in a file named default by running

getauthinfo default

Getauthinfo will prompt for the address of your signer (you can often just use its host name or even localhost) and for a remote username and password combination. Getauthinfo will connect to the inflogin service on the signer and authenticate you against its user and password database, /keydb/keys, using the username and password that you entered above. Answer yes to the question that asks if you want to save the certificate in a file. Getauthinfo will save a certificate in the file /usr/user/keyring/default where user is the name in /dev/user.

12. Network Services

As mentioned above, in a full Inferno network the authentication services will usually be run on a secured machine of their own (the signer), and the ordinary network services such as file service are not run on a signer. If you are, however, using one machine for all functions, you can get the right effect by starting another instance of emu, to act as an Inferno host that is not a signer. This one will run the services of a primary file server and the site registry(4).

Commands described in svc(8) start listeners for various local network services. (The commands are actually shell scripts.) As we saw above, svc/auth starts the services on a signer.

Here we shall start the usual set of services.

• Step 12ab: Start the network listener services.



Various network services will (should!) now be running. To confirm this type


which should show something like the following:

; ps

       1        1    inferno    release    74K Sh[$Sys]

       7        6    inferno        alt    15K Cs

      13        1    inferno       recv    15K Registry

      14        1    inferno    release    44K Styx[$Sys]

      15        1    inferno       recv    15K Registry

      17        1    inferno        alt     8K Listen

      19        1    inferno    release     8K Listen[$Sys]

      22        1    inferno        alt     8K Listen

      24        1    inferno    release     8K Listen[$Sys]

      25        1    inferno      ready    74K Ps[$Sys]

There should be a few Listen processes and perhaps a Registry.

You can also try


Netstat prints information about network connections. You should see several lines of output, each one describing an announced TCP or UDP service. Depending upon the contents of the network configuration files we included on the CD, you might see output something like this:

tcp/1      Announced    inferno!6668      ::!0

tcp/2      Announced    inferno!6666      ::!0

tcp/3      Announced    inferno!6675      ::!0

Each line corresponds to a network connection: the connection name, the name of the user running the server, the address of the local end of the connection, the address of the remote end of the connection, and the connection status. The connection name is actually the protocol and conversation directory in /net. The connection addresses are all of the form host!port for these IP based services, and the remote addresses are not filled in because they all represent listening services that are in the Announced state. In this example the third line shows a TCP service listening on port 6675. Examining /lib/ndb/inferno with grep (see grep(1)) shows that the listener on port 6675 is the Inferno registry service

grep 6675 /lib/ndb/inferno


tcp=registry port=6675  # default registry

Now the server is ready but we need a client.

Either use a third machine or (more likely at first) simply start another emu instance in a new window. Start its connection server, again by typing


The connection server is fundamental to the Inferno network. Once networking is set up, when subsequently starting up a client you should start cs before starting the window system. Note that if you are running the Inferno instance as a server, or combined server and client, the svc/net that starts the network services automatically starts cs, and you need not do so explicitly.

• Step 12ac: Generate a client certificate.

Obtain a certificate for the client in the same way as on the server. We shall obtain a certificate for use with a specific server by storing it in a file whose name exactly matches the network address of the server

getauthinfo tcp!hostname

Use the current machine’s hostname. Getauthinfo stores the certificate in the file /usr/user/keyring/keyname where user is the name in /dev/user and keyname is the argument given to getauthinfo. Again, answer yes to the question that asks if you want to save the certificate in a file.

Now that both client and server have a certificate obtained from the same signer it is possible to establish a secure connection between them. Note that getting keys and certificates with getauthinfo is normally done just once (or at most once per server when the default key is not used). In short, all the work done up to now need not be repeated. After this, provided the keys were saved to a keyring file, as many authenticated connections can be made as desired until the certificate expires (which by default is whenever the password entry was set to expire). Also note that the certificates for different machines can have different signers, and one can even use different certificates for the same machine when the remote user name is to differ (the -f option of getauthinfo can then be useful to force an appropriate keyring name).

• Step 12ad: Make an authenticated connection.

The script svc/net on the server started fundamental name services and also a Styx file service. That can also be started separately using svc/styx. In either case the namespace that is served is the one in which the command was invoked. Now you can test the service.

Confirm that /n/remote is an empty directory by typing

lc /n/remote

You can now mount the server’s name space onto the client’s directory /n/remote by typing

mount  serveraddr /n/remote

Where serveraddr is the IP address of the server or a name that the host can resolve to the IP address of the server. Now

lc /n/remote

should reveal the files and directories in the namespace being served by the server. Those files are now also visible in the namespace of your shell. You will notice that these changes only affect the shell in which you ran the mount command - other windows are unaffected. You can create, remove or modify files and directories in and under /n/remote much as you can any other file or directory in your namespace. In fact, in general, a process does not need to know whether a file actually resides locally or remotely. You can unmount the mounted directory with unmount. Type

unmount /n/remote

You can confirm that it has gone by running

ls /n/remote

All connections made by Inferno are authenticated. The default connection made by mount is authenticated but uses neither encryption nor secure digests. You can pass an argument to mount to specify a more secure connection: its -C option gives it a hashing and an encryption algorithm to be applied to the connection.

• Step 12ae: Make a secure authenticated connection.

For example,

mount  -C sha1/rc4_256 serveraddr /n/remote

makes an authenticated connection to the machine given by serveraddr, then engages SHA1 hashing for message digesting and 256-bit RC4 for encryption.

It mounts the namespace served by serveraddr’s Styx service on the local Inferno directory /n/remote.

13. Adding new users

Every inferno process has an associated user name. At boot time the user name is set equal to your login name on the host operating system. The user name is used by wm/logon to select the home directory, and by other programs like mount when it searches for certificates. (It can also control permission for file access on the local system in native Inferno and some hosted Inferno configurations.) When you attach to a server on another system the user name in the authenticating certificate can be used by the remote file service to set the user name appropriately there.†

To create a new user, copy the directory /usr/inferno into /usr/username. If the user is to have access to services on the network, make an authentication server entry using changelogin(8). The user can change the stored secret using passwd(1), if desired. Having logged in for the first time, the user should generate a default public/private key set using getauthinfo(8). (The authentication services must be running somewhere.)

The wm window manager program wm/logon allows a user to login to the local Inferno system as an Inferno user (different from the host user name). Its use is shown next.

• Step 13ab: Re-start Inferno.

You should now close down any instances of emu that you are currently running. The quickest way to do this is to type control-c in the emu window in which you ran wm/wm. Start a new emu, as before, by either running


or by choosing the appropriate entry from your start menu on Windows machines. This time, start network services


and then run

wm/wm wm/logon

and log in as user inferno. When you log in, wm/logon will change directory to /usr/inferno and then write the name inferno to /dev/user. If the file /usr/inferno/namespace exists it will be used to construct a new namespace for the user based on the commands that it contains (see newns(2)).

14. What next

You should now have a fully functional Inferno system. You will need to have a three button mouse to use acme, wm, or plumbing.

To learn more you could start with the manual pages for: intro(1), emu(1), wm(1), wm-misc(1), sh(1), acme(1), and limbo(1) and also the papers in sections 1, 2 and 3 of Volume 2 of The Inferno Programmer’s Manual.