added notes about checking for port filters or firewall software

[Samba.git] / docs / manpages / smbd.8

.\" This manpage has been automatically generated by docbook2man-spec
.\" from a DocBook document.  docbook2man-spec can be found at:
.\" <http://shell.ipoline.com/~elmert/hacks/docbook2X/> 
.\" Please send any bug reports, improvements, comments, patches, 
.\" etc. to Steve Cheng <steve@ggi-project.org>.
.TH "SMBD" "8" "17 June 2002" "" ""
.SH NAME
smbd \- server to provide SMB/CIFS services to clients
.SH SYNOPSIS
.sp
\fBsmbd\fR [ \fB-D\fR ]  [ \fB-a\fR ]  [ \fB-i\fR ]  [ \fB-o\fR ]  [ \fB-P\fR ]  [ \fB-h\fR ]  [ \fB-V\fR ]  [ \fB-d <debug level>\fR ]  [ \fB-l <log directory>\fR ]  [ \fB-p <port number>\fR ]  [ \fB-O <socket option>\fR ]  [ \fB-s <configuration file>\fR ] 
.SH "DESCRIPTION"
.PP
This program is part of the Samba suite.
.PP
\fBsmbd\fR is the server daemon that 
provides filesharing and printing services to Windows clients. 
The server provides filespace and printer services to
clients using the SMB (or CIFS) protocol. This is compatible 
with the LanManager protocol, and can service LanManager 
clients. These include MSCLIENT 3.0 for DOS, Windows for 
Workgroups, Windows 95/98/ME, Windows NT, Windows 2000, 
OS/2, DAVE for Macintosh, and smbfs for Linux.
.PP
An extensive description of the services that the 
server can provide is given in the man page for the 
configuration file controlling the attributes of those 
services (see \fIsmb.conf(5)
\fR. This man page will not describe the 
services, but will concentrate on the administrative aspects 
of running the server.
.PP
Please note that there are significant security 
implications to running this server, and the \fIsmb.conf(5)\fR
manpage should be regarded as mandatory reading before
proceeding with installation.
.PP
A session is created whenever a client requests one. 
Each client gets a copy of the server for each session. This 
copy then services all connections made by the client during 
that session. When all connections from its client are closed, 
the copy of the server for that client terminates.
.PP
The configuration file, and any files that it includes, 
are automatically reloaded every minute, if they change. You 
can force a reload by sending a SIGHUP to the server. Reloading 
the configuration file will not affect connections to any service 
that is already established. Either the user will have to 
disconnect from the service, or \fBsmbd\fR killed and restarted.
.SH "OPTIONS"
.TP
\fB-D\fR
If specified, this parameter causes 
the server to operate as a daemon. That is, it detaches 
itself and runs in the background, fielding requests 
on the appropriate port. Operating the server as a
daemon is the recommended way of running \fBsmbd\fR for 
servers that provide more than casual use file and 
print services. This switch is assumed if \fBsmbd
\fRis executed on the command line of a shell.
.TP
\fB-a\fR
If this parameter is specified, each new 
connection will append log messages to the log file. 
This is the default.
.TP
\fB-i\fR
If this parameter is specified it causes the
server to run "interactively", not as a daemon, even if the
server is executed on the command line of a shell. Setting this
parameter negates the implicit deamon mode when run from the
command line.
.TP
\fB-o\fR
If this parameter is specified, the 
log files will be overwritten when opened. By default, 
\fBsmbd\fR will append entries to the log 
files.
.TP
\fB-P\fR
Passive option. Causes \fBsmbd\fR not to 
send any network traffic out. Used for debugging by 
the developers only.
.TP
\fB-h\fR
Prints the help information (usage) 
for \fBsmbd\fR.
.TP
\fB-v\fR
Prints the version number for 
\fBsmbd\fR.
.TP
\fB-d <debug level>\fR
\fIdebuglevel\fR is an integer 
from 0 to 10. The default value if this parameter is 
not specified is zero.

The higher this value, the more detail will be 
logged to the log files about the activities of the 
server. At level 0, only critical errors and serious 
warnings will be logged. Level 1 is a reasonable level for
day to day running - it generates a small amount of
information about operations carried out.

Levels above 1 will generate considerable 
amounts of log data, and should only be used when 
investigating a problem. Levels above 3 are designed for 
use only by developers and generate HUGE amounts of log
data, most of which is extremely cryptic.

Note that specifying this parameter here will 
override the log
levelfile.
.TP
\fB-l <log directory>\fR
If specified,
\fIlog directory\fR 
specifies a log directory into which the "log.smbd" log
file will be created for informational and debug 
messages from the running server. The log 
file generated is never removed by the server although 
its size may be controlled by the max log size
option in the \fI smb.conf(5)\fRfile. \fBBeware:\fR
If the directory specified does not exist, \fBsmbd\fR
will log to the default debug log location defined at compile time.

The default log directory is specified at
compile time.
.TP
\fB-O <socket options>\fR
See the socket options
parameter in the \fIsmb.conf(5)
\fRfile for details.
.TP
\fB-p <port number>\fR
\fIport number\fR is a positive integer
value. The default value if this parameter is not 
specified is 139.

This number is the port number that will be 
used when making connections to the server from client 
software. The standard (well-known) port number for the 
SMB over TCP is 139, hence the default. If you wish to
run the server as an ordinary user rather than
as root, most systems will require you to use a port 
number greater than 1024 - ask your system administrator 
for help if you are in this situation.

In order for the server to be useful by most 
clients, should you configure it on a port other 
than 139, you will require port redirection services 
on port 139, details of which are outlined in rfc1002.txt 
section 4.3.5.

This parameter is not normally specified except 
in the above situation.
.TP
\fB-s <configuration file>\fR
The file specified contains the 
configuration details required by the server. The 
information in this file includes server-specific
information such as what printcap file to use, as well 
as descriptions of all the services that the server is 
to provide. See \fI smb.conf(5)\fRfor more information.
The default configuration file name is determined at
compile time.
.SH "FILES"
.TP
\fB\fI/etc/inetd.conf\fB\fR
If the server is to be run by the
\fBinetd\fR meta-daemon, this file 
must contain suitable startup information for the 
meta-daemon. See the UNIX_INSTALL.html
document for details.
.TP
\fB\fI/etc/rc\fB\fR
or whatever initialization script your
system uses).

If running the server as a daemon at startup,
this file will need to contain an appropriate startup
sequence for the server. See the UNIX_INSTALL.html
document for details.
.TP
\fB\fI/etc/services\fB\fR
If running the server via the
meta-daemon \fBinetd\fR, this file
must contain a mapping of service name (e.g., netbios-ssn)
to service port (e.g., 139) and protocol type (e.g., tcp).
See the UNIX_INSTALL.html
document for details.
.TP
\fB\fI/usr/local/samba/lib/smb.conf\fB\fR
This is the default location of the
\fIsmb.conf\fR
server configuration file. Other common places that systems
install this file are \fI/usr/samba/lib/smb.conf\fR
and \fI/etc/smb.conf\fR.

This file describes all the services the server
is to make available to clients. See  \fIsmb.conf(5)\fRfor more information.
.SH "LIMITATIONS"
.PP
On some systems \fBsmbd\fR cannot change uid back
to root after a setuid() call. Such systems are called
trapdoor uid systems. If you have such a system,
you will be unable to connect from a client (such as a PC) as
two different users at once. Attempts to connect the
second user will result in access denied or 
similar.
.SH "ENVIRONMENT VARIABLES"
.TP
\fBPRINTER\fR
If no printer name is specified to 
printable services, most systems will use the value of 
this variable (or lp if this variable is 
not defined) as the name of the printer to use. This 
is not specific to the server, however.
.SH "PAM INTERACTION"
.PP
Samba uses PAM for authentication (when presented with a plaintext
password), for account checking (is this account disabled?) and for
session management. The degree too which samba supports PAM is restricted
by the limitations of the SMB protocol and the
obey pam restricions
smb.conf paramater. When this is set, the following restrictions apply:
.TP 0.2i
\(bu
\fBAccount Validation\fR: All acccesses to a 
samba server are checked 
against PAM to see if the account is vaild, not disabled and is permitted to 
login at this time. This also applies to encrypted logins.
.TP 0.2i
\(bu
\fBSession Management\fR: When not using share 
level secuirty, users must pass PAM's session checks before access
is granted. Note however, that this is bypassed in share level secuirty. 
Note also that some older pam configuration files may need a line 
added for session support. 
.SH "VERSION"
.PP
This man page is correct for version 2.2 of
the Samba suite.
.SH "TROUBLESHOOTING"
.PP
One of the common causes of difficulty when installing Samba and SWAT
is the existsnece of some type of firewall or port filtering software
on the Samba server. Make sure that the appropriate ports
outlined in this man page are available on the server and are not currently
being blocked by some type of security software such as iptables or
"port sentry". For more troubleshooting information, refer to the additional
documentation included in the Samba distribution.
.PP
Most diagnostics issued by the server are logged
in a specified log file. The log file name is specified
at compile time, but may be overridden on the command line.
.PP
The number and nature of diagnostics available depends
on the debug level used by the server. If you have problems, set
the debug level to 3 and peruse the log files.
.PP
Most messages are reasonably self-explanatory. Unfortunately,
at the time this man page was created, there are too many diagnostics
available in the source code to warrant describing each and every
diagnostic. At this stage your best bet is still to grep the
source code and inspect the conditions that gave rise to the
diagnostics you are seeing.
.SH "SIGNALS"
.PP
Sending the \fBsmbd\fR a SIGHUP will cause it to
reload its \fIsmb.conf\fR configuration
file within a short period of time.
.PP
To shut down a user's \fBsmbd\fR process it is recommended
that \fBSIGKILL (-9)\fR \fBNOT\fR
be used, except as a last resort, as this may leave the shared
memory area in an inconsistent state. The safe way to terminate
an \fBsmbd\fR is to send it a SIGTERM (-15) signal and wait for
it to die on its own.
.PP
The debug log level of \fBsmbd\fR may be raised
or lowered using \fBsmbcontrol(1)
\fRprogram (SIGUSR[1|2] signals are no longer used in
Samba 2.2). This is to allow transient problems to be diagnosed,
whilst still running at a normally low log level.
.PP
Note that as the signal handlers send a debug write, 
they are not re-entrant in \fBsmbd\fR. This you should wait until 
\fBsmbd\fR is in a state of waiting for an incoming SMB before 
issuing them. It is possible to make the signal handlers safe 
by un-blocking the signals before the select call and re-blocking 
them after, however this would affect performance.
.SH "SEE ALSO"
.PP
hosts_access(5), \fBinetd(8)\fR, 
\fBnmbd(8)\fR, 
\fIsmb.conf(5)\fR
, \fBsmbclient(1)
\fR, and the Internet RFC's
\fIrfc1001.txt\fR, \fIrfc1002.txt\fR. 
In addition the CIFS (formerly SMB) specification is available 
as a link from the Web page  
http://samba.org/cifs/ <URL:http://samba.org/cifs/>.
.SH "AUTHOR"
.PP
The original Samba software and related utilities 
were created by Andrew Tridgell. Samba is now developed
by the Samba Team as an Open Source project similar 
to the way the Linux kernel is developed.
.PP
The original Samba man pages were written by Karl Auer. 
The man page sources were converted to YODL format (another 
excellent piece of Open Source software, available at
ftp://ftp.icce.rug.nl/pub/unix/ <URL:ftp://ftp.icce.rug.nl/pub/unix/>) and updated for the Samba 2.0 
release by Jeremy Allison. The conversion to DocBook for 
Samba 2.2 was done by Gerald Carter