usmb - Unprivileged mounting of SMB/CIFS shares via FUSE
========================================================

Acknowledgement
---------------

Jonathan Schultz (Email firstname at imatix.com) provided a patch
to fix the display of file modification times.


Introduction
------------

usmb lets you mount SMB/CIFS shares via FUSE, in the vein of the Map Network
Drive functionality in Windows.

The two existing FUSE filesystems that I know of (SMB for FUSE and fusesmb)
mimic Windows' Network Neighbourhood by letting you browse hosts and shares.
This means that you must run a NetBIOS name server and can't see hosts that
aren't advertised via NetBIOS.

You can build [u]mount.cifs in the Samba distribution and install them
setuid root, but that has its own set of security implications. In any
case there's no need for network filesystem code to be in the kernel:
bugs could lead to remotely exploitable kernel vulnerabilities. Running
the SMB client code in user space as an unprivileged user limits the
potential damage due to bugs.

A user space implementation will be slower than a kernel filesystem since
the data must be copied in and out of the fuse process' context as well as
in/out of the user process' context. Mitigating factors are:

1. Increased security.
2. Containment of bugs.
3. Throughput is more likely to be limited by network bandwidth rather than
   local memory copying.
4. The client filesystem code can be upgraded/fixed without kernel changes.


Pre-Requisites
--------------

glib 2.6 or later - www.gtk.org.
libxml2 - ftp.gnome.org.
FUSE 2.6 or later - fuse.sourgeforge.net.
libsmbclient 3.0 (part of Samba) - www.samba.org.


Installation
------------

Sorry, no autoconf yet.
You need GNU sed.
Edit the Makefile with brain engaged.
Run make.
Run make install (maybe as root).


Configuration
-------------

You need an XML configuration file - ${HOME}/.usmb.conf by default. There's an
example in doc/usmb.conf.

There are two main elements: credentials and mounts.

Credentials:

  <credentials id="some_id">
    <domain>mydomain</domain>
    <username>username</username>
    <password>password</password>
  </credentials>

Each credentials element gives authentication details. You can have multiple
credentials elements; each must have a distinct id attribute.

A mount element describes an SMB share:

  <mount id="mount_id" credentials="some_id">
    <server>1.2.3.4</server>
    <share>sharename</share>
    <mountpoint>/tmp/share</mountpoint>
  </mount>

The credentials attribute identifies the id of the credentials element that
provides authentication details for the share. The server, share and
mountpoint should be self-explanatory. The id is given on the usmb command
line to identify the SMB share to mount.

You can specify multiple mount elements; each must have a distinct id
(though credentials and mount IDs can be the same).

The whole file is wrapped in a <usmbconfig> element.


Usage
-----

$ usmb [options] mount_ID

Use usmb --help for a list of options.
Mount IDs are defined in the configuration file.

