This chapter describes the configuration files accepted by the Taylor
UUCP package if compiled with
HAVE_TAYLOR_CONFIG set to 1 in
The configuration files are normally found in the directory newconfigdir, which is defined by the `Makefile' variable `newconfigdir'; by default newconfigdir is `/usr/local/conf/uucp'. However, the main configuration file, `config', is the only one which must be in that directory, since it may specify a different location for any or all of the other files. You may run any of the UUCP programs with a different main configuration file by using the `-I' or `--config' option; this can be useful when testing a new configuration. When you use the `-I' option the programs will revoke any setuid privileges.
UUCP uses several different types of configuration files, each describing a different kind of information. The commands permitted in each file are described in detail below. This section is a brief description of some of the different types of files.
The `config' file is the main configuration file. It describes general information not associated with a particular remote system, such as the location of various log files. There are reasonable defaults for everything that may be specified in the `config' file, so you may not actually need one on your system.
There may be only one `config' file, but there may be one or more of each other type of file. The default is one file for each type, but more may be listed in the `config' file.
The `sys' files are used to describe remote systems. Each remote system to which you connect must be listed in a `sys' file. A `sys' file will include information for a system, such as the speed (baud rate) to use, or when to place calls.
For each system you wish to call, you must describe one or more ports; these ports may be defined directly in the `sys' file, or they may be defined in a `port' file.
The `port' files are used to describe ports. A port is a particular hardware connection on your computer. You would normally define as many ports as there are modems attached to your computer. A TCP connection is also described using a port.
The `dial' files are used to describe dialers. Dialer is essentially another word for modem. The `dial' file describes the commands UUCP should use to dial out on a particular type of modem. You would normally define as many dialers as there are types of modems attached to your computer. For example, if you have three Telebit modems used for UUCP, you would probably define three ports and one dialer.
There are other types of configuration files, but these are the important ones. The other types are described below.
All the configuration files follow a simple line-oriented `keyword value' format. Empty lines are ignored, as are leading spaces; unlike HDB, lines with leading spaces are read. The first word on each line is a keyword. The rest of the line is interpreted according to the keyword. Most keywords are followed by numbers, boolean values or simple strings with no embedded spaces.
The # character is used for comments. Everything from a # to the end of the line is ignored unless the # is preceded by a \ (backslash); if the # is preceeded by a \, the \ is removed but the # remains in the line. This can be useful for a phone number containing a #. To enter the sequence `\#', use `\\#'.
The backslash character may be used to continue lines. If the last character in a line is a backslash, the backslash is removed and the line is continued by the next line. The second line is attached to the first with no intervening characters; if you want any whitespace between the end of the first line and the start of the second line, you must insert it yourself.
However, the backslash is not a general quoting character. For example, you cannot use it to get an embedded space in a string argument.
Everything after the keyword must be on the same line. A boolean
may be specified as y, Y, t, or T for true and
n, N, f, or F for false; any trailing characters
are ignored, so
false, etc., are also acceptable.
This section provides few typical examples of configuration files. There are also sample configuration files in the `sample' subdirectory of the distribution.
To start with, here are some examples of uses of the main configuration file, `config'. For a complete description of the commands that are permitted in `config', see section The Main Configuration File.
In many cases you will not need to create a `config' file at all. The most common reason to create one is to give your machine a special UUCP name. Other reasons might be to change the UUCP spool directory, or to permit any remote system to call in.
If you have an internal network of machines, then it is likely that the internal name of your UUCP machine is not the name you want to use when calling other systems. For example, here at `airs.com' our mail/news gateway machine is named `elmer.airs.com' (it is one of several machines all named `localname.airs.com'). If we did not provide a `config' file, then our UUCP name would be `elmer'; however, we actually want it to be `airs'. Therefore, we use the following line in `config':
The UUCP spool directory name is set in `policy.h' when the code is compiled. You might at some point decide that it is appropriate to move the spool directory, perhaps to put it on a different disk partition. You would use the following commands in `config' to change to directories on the partition `/uucp':
spool /uucp/spool pubdir /uucp/uucppublic logfile /uucp/spool/Log debugfile /uucp/spool/Debug
You would then move the contents of the current spool directory to `/uucp/spool'. If you do this, make sure that no UUCP processes are running while you change `config' and move the spool directory.
Suppose you wanted to permit any system to call in to your system and
request files. This is generally known as anonymous UUCP, since
the systems which call in are effectively anonymous. By default,
unknown systems are not permitted to call in. To permit this you must
unknown command in `config'. The
command is followed by any command that may appear in the system file;
for full details, see section The System Configuration File.
I will show two possible anonymous UUCP configurations. The first will let any system call in and download files, but will not permit them to upload files to your system.
# No files may be transferred to this system unknown receive-request no # The public directory is /usr/spool/anonymous unknown pubdir /usr/spool/anonymous # Only files in the public directory may be sent (the default anyhow) unknown remote-send ~
Setting the public directory is convenient for the systems which call in. It permits to request a file by prefixing it with `~/'. For example, assuming your system is known as `server', then to retrieve the file `/usr/spool/anonymous/INDEX' a user on a remote site could just enter `uucp server!~/INDEX ~'; this would transfer `INDEX' from `server''s public directory to the user's local public directory. Note that when using `csh' or `bash' the ! and the second ~ must be quoted.
The next example will permit remote systems to upload files to a special directory named `/usr/spool/anonymous/upload'. Permitting a remote system to upload files permits it to send work requests as well; this example is careful to prohibit commands from unknown systems.
# No commands may be executed (the list of permitted commands is empty) unknown commands # The public directory is /usr/spool/anonymous unknown pubdir /usr/spool/anonymous # Only files in the public directory may be sent; users may not download # files from the upload directory unknown remote-send ~ !~/upload # May only upload files into /usr/spool/anonymous/upload unknown remote-receive ~/upload
A relatively common simple case is a leaf site, a system which only calls or is called by a single remote site. Here is a typical `sys' file that might be used in such a case. For full details on what commands can appear in the `sys' file, see section The System Configuration File.
This is the `sys' file that is used at `airs.com'. We use a single modem to dial out to `uunet'. This example shows how you can specify the port and dialer information directly in the `sys' file for simple cases. It also shows the use of the following:
call-passwordallows the default login chat script to be used. In this case, the login name is specified in the call-out login file (see section Configuration File Names).
This `sys' file relies on certain defaults. It will allow `uunet' to queue up `rmail' and `rnews' commands. It will allow users to request files from `uunet' into the UUCP public directory. It will also allow `uunet' to request files from the UUCP public directory; in fact `uunet' never requests files, but for additional security we could add the line `request false'.
# The following information is for uunet system uunet # The login name and password are kept in the callout password file call-login * call-password * # We can send anything at any time. time any # During the day we only accept grade `Z' or above; at other times # (not mentioned here) we accept all grades. uunet queues up news # at grade `d', which is lower than `Z'. call-timegrade Z Wk0755-2305,Su1655-2305 # The phone number. phone 7389449 # uunet tends to be slow, so we increase the timeout chat-timeout 120 # We are using a preconfigured Telebit 2500. port type modem port device /dev/ttyd0 port speed 19200 port carrier true port dialer chat "" ATZ\r\d\c OK ATDT\D CONNECT port dialer chat-fail BUSY port dialer chat-fail NO\sCARRIER port dialer complete \d\d+++\d\dATH\r\c port dialer abort \d\d+++\d\dATH\r\c # Increase the timeout and the number of retries. protocol-parameter g timeout 20 protocol-parameter g retries 10
Many organizations have several local machines which are connected by UUCP, and a single machine which connects to the outside world. This single machine is often referred to as a gateway machine.
For this example I will assume a fairly simple case. It should still provide a good general example. There are three machines, `elmer', `comton' and `bugs'. `elmer' is the gateway machine for which I will show the configuration file. `elmer' calls out to `uupsi'. As an additional complication, `uupsi' knows `elmer' as `airs'; this will show how a machine can have one name on an internal network but a different name to the external world. `elmer' has two modems. It also has an TCP connection to `uupsi', but since that is supposed to be reserved for interactive work (it is, perhaps, only a 9600 baud SLIP line) it will only use it if the modems are not available.
A network this small would normally use a single `sys' file.
However, for pedagogical purposes I will show two separate `sys'
files, one for the local systems and one for `uupsi'. This is done
sysfile command in the `config' file. Here is the
# This is config # The local sys file sysfile /usr/local/lib/uucp/sys.local # The remote sys file sysfile /usr/local/lib/uucp/sys.remote
Using the defaults feature of the `sys' file can greatly simplify the listing of local systems. Here is `sys.local'. Note that this assumes that the local systems are trusted; they are permited to request any world readable file and to write files into any world writable directory.
# This is sys.local # Get the login name and password to use from the call-out file call-login * call-password * # The systems must use a particular login called-login Ulocal # Permit sending any world readable file local-send / remote-send / # Permit receiving into any world writable directory local-receive / remote-receive / # Call at any time time any # Use port1, then port2 port port1 alternate port port2 # Now define the systems themselves. Because of all the defaults we # used, there is very little to specify for the systems themselves. system comton phone 5551212 system bugs phone 5552424
The `sys.remote' file describes the `uupsi' connection. The
myname command is used to change the UUCP name to `airs'
when talking to `uupsi'.
# This is sys.remote # Define uupsi system uupsi # The login name and password are in the call-out file call-login * call-password * # We can call out at any time time any # uupsi uses a special login name called-login Uuupsi # uuspi thinks of us as `airs' myname airs # The phone number phone 5554848 # We use port2 first, then port1, then TCP port port2 alternate port port1 alternate # We don't bother to make a special entry in the port file for TCP, we # just describe the entire port right here. We use a special chat # script over TCP because the usual one confuses some TCP servers. port type TCP address uu.psi.com chat ogin: \L word: \P
The ports are defined in the file `port' (see section The Port Configuration File). For this example they are both connected to the same type of 2400 baud Hayes-compatible modem.
# This is port port port1 type modem device /dev/ttyd0 dialer hayes speed 2400 port port2 type modem device /dev/ttyd1 dialer hayes speed 2400
Dialers are described in the `dial' file (see section The Dialer Configuration File).
# This is dial dialer hayes # The chat script used to dial the phone. \D is the phone number. chat "" ATZ\r\d\c OK ATDT\D CONNECT # If we get BUSY or NO CARRIER we abort the dial immediately chat-fail BUSY chat-fail NO\sCARRIER # When the call is over we make sure we hangup the modem. complete \d\d+++\d\dATH\r\c abort \d\d+++\d\dATH\r\c
Several commands use time strings to specify a range of times. This section describes how to write time strings.
A time string may be a list of simple time strings separated with a vertical bar `|' or a comma `,'.
Each simple time string must begin with `Su', `Mo', `Tu', `We', `Th', `Fr', or `Sa', or `Wk' for any weekday, or `Any' for any day.
Following the day may be a range of hours separated with a hyphen using 24 hour time. The range of hours may cross 0; for example `2300-0700' means any time except 7 AM to 11 PM. If no time is given, calls may be made at any time on the specified day(s).
The time string may also be the single word `Never', which does not
match any time. The time string may also be a single word with a name
defined in a previous
timetable command (see section Miscellaneous config File Commands).
Here are a few sample time strings with an explanation of what they mean.
Chat scripts are used in several different places, such as dialing out on modems or logging in to remote systems. Chat scripts are made up of pairs of strings. The program waits until it sees the first string, known as the expect string, and then sends out the second string, the send string.
Each chat script is defined using a set of commands. These commands
always end in a string beginning with
chat, but may start with
different strings. For example, in the `sys' file there is one set
of commands beginning with
chat and another set beginning with
called-chat. The prefixes are only used to disambiguate
different types of chat scripts, and this section ignores the prefixes
when describing the commands.
chatcommand are pairs of strings separated by whitespace. The first string of each pair is an expect string, the second is a send string. The program will wait for the expect string to appear; when it does, the program will send the send string. If the expect string does not appear within a certain number of seconds (as set by the
chat-timeoutcommand), the chat script fails and, typically, the call is aborted. If the final expect string is seen (and the optional final send string has been sent), the chat script is successful. An expect string may contain additional subsend and subexpect strings, separated by hyphens. If the expect string is not seen, the subsend string is sent and the chat script continues by waiting for the subexpect string. This means that a hyphen may not appear in an expect string; on an ASCII system, use `\055' instead. An expect string may simply be `""', meaning to skip the expect phase. Otherwise, the following escape characters may appear in expect strings:
chat-timeout(described below) only for the expect string to which it is attached. A send string may simply be `""' to skip the send phase. Otherwise, all of the escape characters legal for expect strings may be used, and the following escape characters are also permitted:
chat-failcommands may appear in a single chat script. The default is to have none. This permits a chat script to be quickly aborted if an error string is seen. For example, a script used to dial out on a modem might use the command `chat-fail BUSY' to stop the chat script immediately if the string `BUSY' was seen. The
chat-failstrings are considered in the order they are listed, so if one string is a suffix of another the longer one should be listed first. This affects the error message which will be logged. Of course, if one string is contained within another, but is not a suffix, the smaller string will always be found before the larger string could match.
chat-program, which must ignore parity by itself if necessary.
chatare specified, the program is executed first followed by the chat script. The first argument to the
chat-programcommand is the program name to run. The remaining arguments are passed to the program. The following escape sequences are recognized in the arguments:
chat-programdefine additional escape sequences. Arguments other than escape sequences are passed exactly as they appear in the configuration file, except that sequences of whitespace are compressed to a single space character (this exception may be removed in the future). If the
chat-programcommand is not used, no program is run. On Unix, the standard input and standard output of the program will be attached to the port in use. Anything the program writes to standard error will be written to the UUCP log file. No other file descriptors will be open. If the program does not exit with a status of 0, it will be assumed to have failed. This means that the dialing programs used by some versions of HDB may not be used directly, but you may be able to run them via the
dialHDBprogram in the `contrib' directory. The program will be run as the
uucpuser, and the environment will be that of the process that started
uucico, so care must be taken to maintain security. No search path is used to find the program; a full file name must be given. If the program is an executable shell script, it will be passed to `/bin/sh' even on systems which are unable to execute shell scripts.
Here is a simple example of a chat script that might be used to reset a Hayes compatible modem.
chat "" ATZ OK-ATZ-OK
The first expect string is `""', so it is ignored. The chat script then sends `ATZ'. If the modem responds with `OK', the chat script finishes. If 60 seconds (the default timeout) pass before seeing `OK', the chat script sends another `ATZ'. If it then sees `OK', the chat script succeeds. Otherwise, the chat script fails.
For a more complex chat script example, see section Logging In.
The main configuration file is named `config'.
Since all the values that may be specified in the main configuration file also have defaults, there need not be a main configuration file at all.
Each command in `config' may have a program prefix, which is a
separate word appearing at the beginning of the line. The currently
supported prefixes are `uucp' and `cu'. Any command prefixed
by `uucp' will not be read by the
cu program. Any command
prefixed by `cu' will only be read by the
cu program. For
example, to use a list of systems known only to
cu, list them in
a separate file `file' and put `cu sysfile
`file'' in `config'.
pubdircommand in the system configuration file; see section Miscellaneous sys File Commands.
unknown string ...
unknowncommand is not used, unknown systems are not permitted to call in.
uucicois doing its own login prompting with the `-e', `-l', or `-w' switches, it will strip the parity bit when it reads the login name and password. Otherwise all eight bits will be used when checking the strings against the UUCP password file. The default is true, since some other UUCP packages send parity bits with the login name and password, and few systems use eight bit characters in the password file.
uucicowill strip the parity bit from incoming UUCP protocol commands. Otherwise all eight bits will be used. This only applies to commands which are not encapsulated in a link layer protocol. The default is true, which should always be correct unless your UUCP system names use eight bit characters.
uuxqtprocesses which may run at the same time. Having several
uuxqtprocesses running at once can significantly slow down a system, but, since
uuxqtis automatically started by
uucico, it can happen quite easily. The default for
max-uuxqtsis 0, which means that there is no limit. If HDB configuration files are being read and the code was compiled without
HAVE_TAYLOR_CONFIG, then, if the file `Maxuuxqts' in the configuration directory contains a readable number, it will be used as the value for
run-uuxqt string or number
uuxqtshould be run by
uucico. This may be a positive number, in which case
uucicowill start a
uuxqtprocess whenever it receives the given number of execution files from the remote system, and, if necessary, at the end of the call. The argument may also be one of the strings `once', `percall', or `never'. The string `once' means that
uuxqtonce at the end of execution. The string `percall' means that
uuxqtonce per call that it makes (this is only different from
uucicois invoked in a way that causes it to make multiple calls, such as when the `-r1' option is used without the `-s' option). The string `never' means that
uucicowill never start
uuxqt, in which case
uuxqtshould be periodically run via some other mechanism. The default depends upon which type of configuration files are being used; if
HAVE_TAYLOR_CONFIGis used the default is `once', otherwise if
HAVE_HDB_CONFIGis used the default is `percall', and otherwise, for
HAVE_V2_CONFIG, the default is `10'.
timetable string string
timetabledefines a timetable that may be used in subsequently appearing time strings; see section Time Strings. The first string names the timetable entry; the second is a time string. The following
timetablecommands are predefined. The NonPeak timetable is included for compatibility. It originally described the offpeak hours of Tymnet and Telenet, but both have since changed their schedules.
timetable Evening Wk1705-0755,Sa,Su timetable Night Wk2305-0755,Sa,Su2305-1655 timetable NonPeak Wk1805-0655,Sa,SuIf this command does not appear, then, obviously, no additional timetables will be defined.
sysfilecommand may be repeated; each system file has its own set of defaults.
portfilecommand may be repeated.
dialfilecommand may be repeated.
dialcodefilecommand may be repeated; all the dialcode files will be read in turn until a dialcode is located.
passwdfilebelow is used for incoming calls. The intention of the call out file is to permit the system file to be publically readable; the call out files must obviously be kept secure. These files need not be used. Multiple call out files may be specified on the line, and the
callfilecommand may be repeated; all the files will be read in turn until the system is found.
uucicois doing its own login prompting, which it does when given the `-e', `-l' or `-w' switches. The default is the file `passwd' in the directory newconfigdir. Each line in the file(s) has two words: the login name and the password (e.g.,
Ufoo foopas). They may contain escape sequences like those in a chat script expect string (see section Chat Scripts). The login name is accepted before the system name is known, so these are independent of which system is calling in; a particular login may be required for a system by using the
called-logincommand in the system file (see section Accepting a Call). These password files are optional, although one must exist if
uucicois to present its own login prompts. As a special exception, a colon may be used to separate the login name from the password, and a colon may be used to terminate the password. This means that the login name and password may not contain a colon. This feature, in conjunction with the
HAVE_ENCRYPTED_PASSWORDSmacro in `policy.h', permits using a standard Unix `/etc/passwd' as a UUCP password file, providing the same set of login names and passwords for both
uucico. Multiple password files may be specified on the line, and the
passwdfilecommand may be repeated; all the files will be read in turn until the login name is found.
HAVE_HDB_LOGGINGis defined in `policy.h', then by default a separate log file is used for each system; using this command to name a log file will cause all the systems to use it.
DEBUGmacro in `policy.h'). If debugging is on, messages written to the log file are also written to the debugging file to make it easier to keep the order of actions straight. The debugging file is different from the log file because information such as passwords can appear in it, so it must be not be publically readable.
debug string ...
debugcommand may be used several times in the configuration file; every debugging type named will be turned on. When running any of the programs, the `-x' switch (actually, for
uulogit's the `-X' switch) may be used to turn on debugging. The argument to the `-x' switch is one of the strings listed above, or a number as described above, or a comma separated list of strings (e.g., `-x chat,handshake'). The `-x' switch may also appear several times on the command line, in which case all named debugging types will be turned on. The `-x' debugging is in addition to any debugging specified by the
debugcommand; there is no way to cancel debugging information. The debugging level may also be set specifically for calls to or from a specific system with the
debugcommand in the system file (see section Miscellaneous sys File Commands). The debugging messages are somewhat idiosyncratic; it may be necessary to refer to the source code for additional information in some cases.
By default there is a single system configuration, named `sys' in
the directory newconfigdir. This may be overridden by the
sysfile command in the main configuration file; see
section Configuration File Names.
These files describe all remote systems known to the UUCP package.
The first set of commands in the file, up to the first
command, specify defaults to be used for all systems in that file. Each
`sys' file uses a different set of defaults.
Subsequently, each set of commands from
system up to the next
system command describe a particular system. Default values may
be overridden for specific systems.
Each system may then have a series of alternate choices to use when
calling out or calling in. The first set of commands for a particular
system, up to the first
alternate command, provide the first
choice. Subsequently, each set of commands from
alternate up to
alternate command describe an alternate choice for
calling out or calling in.
When a system is called, the commands before the first
are used to select a phone number, port, and so forth; if the call fails
for some reason, the commands between the first
alternate and the
second are used, and so forth. Well, not quite. Actually, each
succeeding alternate will only be used if it is different in some
relevant way (different phone number, different chat script, etc.). If
you want to force the same alternate to be used again (to retry a phone
call more than once, for example), enter the phone number (or any other
relevant field) again to make it appear different.
The alternates can also be used to give different permissions to an
incoming call based on the login name. This will only be done if the
first set of commands, before the first
alternate command, uses
called-login command. The list of alternates will be
searched, and the first alternate with a matching
command will be used. If no alternates match, the call will be
alternate command may also be used in the file-wide defaults
(the set of commands before the first
system command). This
might be used to specify a list of ports which are available for all
systems (for an example of this, see section Gateway Example) or to
specify permissions based on the login name used by the remote system
when it calls in. The first alternate for each system will default to
the first alternate for the file-wide defaults (as modified by the
commands used before the first
alternate command for this
system), the second alternate for each system to the second alternate
for the file-wide defaults (as modified the same way), and so forth. If
a system specifies more alternates than the file-wide defaults, the
trailing ones will default to the last file-wide default alternate. If
a system specifies fewer alternates than the file-wide defaults, the
trailing file-wide default alternates will be used unmodified. The
default-alternates command may be used to modify this behaviour.
This can all get rather confusing, although it's easier to use than to
describe concisely; the
uuchk program may be used to ensure that
you are getting what you want.
systemcommand refer to this system.
uuxcommands, as well as by the remote system (which can be convenient if a remote system changes its name). The default is to have no aliases.
called-loginis used and is not `ANY', then, when a system logs in with that login name, string is used as the local system name. Because the local system name must be determined before the remote system has identified itself, using
called-logintogether for any system will set the local name for that login; this means that each locally used system name must have a unique login name associated with it. This allows a system to have different names for an external and an internal network. The default is to not use a special local name.
This section describes commands used when placing a call to another system.
time string [number]
timecommand is always a fixed amount of time. The
timecommand may appear multiple times in a single alternate, in which case if any time string matches the system may be called. When the
timecommand is used for a particular system, any
timegradecommands that appeared in the system defaults are ignored. The default time string is `Never'.
timegrade character string [number]
timecommand is equivalent to using
timegradewith a grade of z, permitting all jobs. If there are no jobs of a sufficiently high grade according to the time string, the system will not be called. Giving the `-s' switch to
uucicoto force it to call a system causes it to assume there is a job of grade 0 waiting to be run. The optional third argument specifies a retry time in minutes. See the
timecommand, above, for more details. Note that the
timegradecommand serves two purposes: 1) if there is no job of sufficiently high grade the system will not be called, and 2) if the system is called anyway (because the `-s' switch was given to
uucico) only jobs of sufficiently high grade will be transferred. However, if the other system calls in, the
timegradecommands are ignored, and jobs of any grade may be transferred (but see
called-timegrade, below). Also, the
timegradecommand will not prevent the other system from transferring any job it chooses, regardless of who placed the call. The
timegradecommand may appear multiple times without using
alternate. When the
timegradecommand is used for a particular system, any
timegradecommands that appeared in the system defaults are ignored. If this command does not appear, there are no restrictions on what grade of work may be done at what time.
call-timegrade character string
call-timegradecommand may appear multiple times without using
alternate. If this command does not appear, or if none of the time strings match, the remote system will be allowed to send whatever grades of work it chooses.
called-timegrade character string
called-timegradecommand may appear multiple times. If this command does not appear, or if none of the time strings match, any grade may be sent to the remote system upon receiving a call.
portcommands appear, both are used when selecting a port. To allow calls at more than one speed, the
alternatecommand must be used (see section Defaults and Alternates). If this command does not appear, there is no default; the speed may be specified in the port file, but if it is not then the natural speed of the port will be used (whatever that means on the system). Specifying an explicit speed of 0 will request the natural speed of the port (whatever the system sets it to), overriding any default speed from the defaults at the top of the file.
speedcommand or explicitly using the next version of
port). There may be many ports with the same name; each will be tried in turn until an unlocked one is found which matches the desired speed.
port string ...
portcommand, the strings are treated as a command that might appear in the port file (see section The Port Configuration File). If a port is named (by using a single string following
port) these commands are ignored; their purpose is to permit defining the port completely in the system file rather than always requiring entries in two different files. In order to call out, a port must be specified using some version of the
portcommand, or by using the
speedcommand to select ports from the port file.
addressare equivalent; the duplication is intended to provide a mnemonic choice depending on the type of port in use. When used with a modem port, an = character in the phone number means to wait for a secondary dial tone (although only some modems support this); a - character means to pause while dialing for 1 second (again, only some modems support this). If the system has more than one phone number, each one must appear in a different alternate. The
phonecommand must appear in order to call out on a modem; there is no default. When used with a TCP port, the string names the host to contact. It may be a domain name or a numeric Internet address. If no address is specified, the system name is used. When used with a TLI port, the string is treated as though it were an expect string in a chat script, allowing the use of escape characters (see section Chat Scripts). The
dialer-sequencecommand in the port file may override this address (see section The Port Configuration File). When used with a port that not a modem or TCP or TLI, this command is ignored.
chat-programcommand. These are `\L' and `\P', which become the login name and password, respectively, and `\Z', which becomes the name of the system of being called. The default chat script is:
chat "" \r\c ogin:-BREAK-ogin:-BREAK-ogin: \L word: \PThis will send a carriage return (the \c suppresses the additional trailing carriage return that would otherwise be sent) and waits for the string `ogin:' (which would be the last part of the `login:' prompt supplied by a Unix system). If it doesn't see `ogin:', it sends a break and waits for `ogin:' again. If it still doesn't see `ogin:', it sends another break and waits for `ogin:' again. If it still doesn't see `ogin:', the chat script aborts and hangs up the phone. If it does see `ogin:' at some point, it sends the login name (as specified by the
call-logincommand) followed by a carriage return (since all send strings are followed by a carriage return unless \c is used) and waits for the string `word:' (which would be the last part of the `Password:' prompt supplied by a Unix system). If it sees `word:', it sends the password and a carriage return, completing the chat script. The program will then enter the handshake phase of the UUCP protocol. This chat script will work for most systems, so you will only be required to use the
call-passwordcommands. In fact, in the file-wide defaults you could set defaults of `call-login *' and `call-password *'; you would then just have to make an entry for each system in the call-out login file. Some systems seem to flush input after the `login:' prompt, so they may need a version of this chat script with a \d before the \L. When using UUCP over TCP, some servers will not be handle the initial carriage return sent by this chat script; in this case you may have to specify the simple chat script `ogin: \L word: \P'.
called-logincommands, in which case the login name will be used to select which alternate is in effect; this will only work if the first alternate (before the first
alternatecommand) uses the
called-logincommand. Additional strings may be specified after the login name; they are a list of which systems are permitted to use this login name. If this feature is used, then normally the login name will only be given in a single
called-logincommand. Only systems which appear on the list, or which use an explicit
called-logincommand, will be permitted to use that login name. If the same login name is used more than once with a list of systems, all the lists are concatenated together. This feature permits you to restrict a login name to a particular set of systems without requiring you to use the
called-logincommand for every single system; you can achieve a similar effect by using a different system file for each permitted login name with an appropriate
called-logincommand in the file-wide defaults.
uucicowill hang up the connection and prepare to call it back. The default is false.
chatcommand (see section Logging In), on the other hand, is used when the remote system is called. This called chat script might be used to set special modem parameters that are appropriate to a particular system. It is run after protocol negotiation is complete, but before the protocol has been started. For additional escape sequence which may be used besides those defined for all chat scripts, see section Logging In. There is no default called chat script. If the called chat script fails, the incoming call will be aborted.
reliablecommands. If neither the port nor the dialer use either of these commands, the default is to assume an eight-bit reliable connection. The commands `seven-bit true' or `reliable false' might be used in either the port or the dialer to change this. Each protocol has particular requirements that must be met before it will be considered during negotiation with the remote side. The `t' and `e' protocols are intended for use over TCP or some other communication path with end to end reliability, as they do no checking of the data at all. They will only be considered on a TCP port which is both reliable and eight bit. For technical details, see section UUCP `t' Protocol, and section UUCP `e' Protocol. The `i' protocol is a bidirectional protocol. It requires an eight-bit connection. It will run over a half-duplex link, such as Telebit modems in PEP mode, but for efficient use of such a connection you must use the
half-duplexcommand (see section The Port Configuration File). See section UUCP `i' Protocol. The `g' protocol is robust, but requires an eight-bit connection. See section UUCP `g' Protocol. The `G' protocol is the System V Release 4 version of the `g' protocol. See section UUCP `G' Protocol. The `a' protocol is a Zmodem like protocol, contributed by Doug Evans. It requires an eight-bit connection, but unlike the `g' or `i' protocol it will work if certain control characters may not be transmitted. The `j' protocol is a variant of the `i' protocol which can avoid certain control characters. The set of characters it avoids can be set by a parameter. While it technically does not require an eight bit connection (it could be configured to avoid all characters with the high bit set) it would be very inefficient to use it over one. It is useful over a eight-bit connection that will not transmit certain control characters. See section UUCP `j' Protocol. The `f' protocol is intended for use with X.25 connections; it checksums each file as a whole, so any error causes the entire file to be retransmitted. It requires a reliable connection, but only uses seven-bit transmissions. It is a streaming protocol, so, while it can be used on a serial port, the port must be completely reliable and flow controlled; many aren't. See section UUCP `f' Protocol. The `v' protocol is the `g' protocol as used by the DOS program UUPC/Extended. It is provided only so that UUPC/Extended users can use it; there is no particular reason to select it. See section UUCP `v' Protocol. The `y' protocol is an efficient streaming protocol. It does error checking, but when it detects an error it immediately aborts the connection. This requires a reliable, flow controlled, eight-bit connection. In practice, it is only useful on a connection that is nearly always error-free. Unlike the `t' and `e' protocols, the connection need not be entirely error-free, so the `y' protocol can be used on a serial port. See section UUCP `y' Protocol. The protocols will be considered in the order shown above. This means that if neither the
reliablecommand are used, the `t' protocol will be used over a TCP connection and the `i' protocol will be used over any other type of connection (subject, of course, to what is supported by the remote system; it may be assumed that all systems support the `g' protocol). Note that currently specifying both `seven-bit true' and `reliable false' will not match any protocol. If this occurs through a combination of port and dialer specifications, you will have to use the
protocolcommand for the system or no protocol will be selected at all (the only reasonable choice would be `protocol f'). A protocol list may also be specified for a port (see section The Port Configuration File), but, if there is a list for the system, the list for the port is ignored.
protocol-parameter character string ...
errors. The default is 10.
short-packetswhich takes a boolean argument:
errors. The default is 10.
escape-control, which takes a boolean argument:
XOFF. The connection must still transmit eight bit characters other than control characters. The default is false.
XOFF, which many connections use for flow control. If the package is configured to use
HAVE_BSD_TTY, then on some versions of Unix you may have to avoid `\377' as well, due to the way some implementations of the BSD terminal driver handle signals.
call-local-size number string
call-remote-size number string
called-local-size number string
called-remote-size number string
uux). The directories in the list should be separated by whitespace. A `~' may be used for the public directory. On a Unix system, this is typically `/usr/spool/uucppublic'; the public directory may be set with the
pubdircommand. Here is an example of
local-send ~ /usr/spool/ftp/pubListing a directory allows all files within the directory and all subdirectories to be sent. Directories may be excluded by preceding them with an exclamation point. For example:
local-send /usr/ftp !/usr/ftp/private ~means that all files in `/usr/ftp' or the public directory may be sent, except those files in `/usr/ftp/private'. The list of directories is read from left to right, and the last directory to apply takes effect; this means that directories should be listed from top down. The default is the root directory (i.e., any file at all may be sent by local request).
uucpcommand, it effectively has the ability to forward to any system.
uucpcommand, it effectively has the ability to request files from any system.
uux, not for chat programs. The default is from `policy.h'.
uucicowill periodically check the amount of free space. If it drops below the amount given by the
free-spacecommand, the file transfer will be aborted. The default amount of space to leave free is from `policy.h'. This file space checking may not work on all systems.
debug string ...
debugcommand in the main configuration file (see section Debugging Levels) for more details. The debugging information specified here is in addition to that specified in the main configuration file or on the command line.
max-remote-debug string ...
max-remote-debugcommand may be used to put a limit on the debugging level which the system may request, to avoid filling up the disk with debugging information. Only the debugging types named in the
max-remote-debugcommand may be turned on by the remote system. To prohibit any debugging, use `max-remote-debug none'.
The following are used as default values for all systems; they can be considered as appearing before the start of the file.
time Never chat "" \r\c ogin:-BREAK-ogin:-BREAK-ogin: \L word: \P chat-timeout 10 callback n sequence n request y transfer y local-send / remote-send ~ local-receive ~ remove-receive ~ command-path [ from `policy.h' ] commands rnews rmail max-remote-debug abnormal,chat,handshake
The port files may be used to name and describe ports. By default there
is a single port file, named `port' in the directory
newconfigdir. This may be overridden by the
command in the main configuration file; see section Configuration File Names.
Any commands in a port file before the first
port command specify
defaults for all ports in the file; however, since the
command must appear before all other commands for a port, the defaults
are only useful if all ports in the file are of the same type (this
restriction may be lifted in a later version). All commands after a
port command up to the next
port command then describe
that port. There are different types of ports; each type supports its
own set of commands. Each command indicates which types of ports
support it. There may be many ports with the same name; if a system
requests a port by name then each port with that name will be tried
until an unlocked one is found.
portcommand. The type defines what commands are subsequently allowed. Currently the types are:
uucicois run as a login shell.
protocol-parameter character strings [ any type ]
protocol-parametercommand used for systems (see section Protocol Selection). This one takes precedence.
seven-bit boolean [ any type ]
reliable boolean [ any type ]
half-duplex boolean [ any type ]
device string [ modem, direct and tli only ]
speed number [modem and direct only ]
baud number [ modem and direct only ]
speed-range number number [ modem only ]
baud-range number number [ modem only ]
baud) command is still used to determine the speed to run at if the system does not specify a speed. For example, the command `speed-range 300 19200' means that the port will match any system which uses a speed from 300 to 19200 baud (and will use the speed specified by the system); this could be combined with `speed 2400', which means that when this port is used with a system that does not specify a speed, the port will be used at 2400 baud.
carrier boolean [ modem and direct only ]
hardflow boolean [ modem and direct only ]
dial-device string [ modem only ]
dialer string [ modem only ]
dialer string ... [ modem only ]
dialercommand, the strings are treated as a command that might appear in the dial file (see section The Dialer Configuration File). If a dialer is named (by using the first form of this command, described just above), these commands are ignored. They may be used to specify dialer information directly in simple situations without needing to go to a separate file. There is no default. Some sort of dialer information must be specified to call out on a modem.
dialer-sequence strings [ modem or tcp or tli only ]
phonecommand in the system file is used as the final token. The token is what is used for \D or \T in the dialer chat script. If the token in this string is \D, the system phone number will be used; if it is \T, the system phone number will be used after undergoing dialcodes translation. A missing final token is taken as \D. This command currently does not work if
dial-deviceis specified; to handle this correctly will require a more systematic notion of chat scripts. Moreover, the
abortchat scripts, the protocol parameters, and the
dtr-togglecommands are ignored for all but the first dialer. This command basically lets you specify a sequence of chat scripts to use. For example, the first dialer might get you to a local network and the second dialer might describe how to select a machine from the local network. This lets you break your dialing sequence into simple modules, and may make it easier to share dialer entries between machines. This command is to only way to use a chat script with a TCP port. This can be useful when using a modem which is accessed via TCP. When this command is used with a TLI port, then if the first dialer is `TLI' or `TLIS' the first token is used as the address to connect to. If the first dialer is something else, or if there is no token, the address given by the
addresscommand is used (see section Placing the Call). Escape sequences in the address are expanded as they are for chat script expect strings (see section Chat Scripts). The different between `TLI' and `TLIS' is that the latter implies the command `stream true'. These contortions are all for HDB compatibility. Any subsequent dialers are treated as they are for a TCP port.
lockname string [ modem and direct only ]
lockname LCK..ttycu0could be used to force the latter to use the same lock file name as the former.
service string [ tcp only ]
push strings [ tli only ]
stream boolean [ tli only ]
pushcommand was not used, the `tirdwr' module is pushed on to the TLI stream.
server-address string [ tli only ]
t_bindfunction. The value needed may depend upon your particular TLI implementation. Check the manual pages, and, if necessary, try writing some sample programs. For AT&T 3B2 System V Release 3 using the Wollongong TCP/IP stack, which is probably typical, the format of TLI string is `SSPPIIII', where `SS' is the service number (for TCP, this is 2), `PP' is the TCP port number, and `IIII' is the Internet address. For example, to accept a connection from on port 540 from any interface, use `server-address \x00\x02\x02\x1c\x00\x00\x00\x00'. To only accept connections from a particular interface, replace the last four digits with the network address of the interface. (Thanks to Paul Pryor for the information in this paragraph).
command strings [ pipe only ]
uucicocommunicates with it over a pipe. This permits
cuto communicate with another system which can only be reached through some unusual means. A sample use might be `command /bin/rlogin -E -8 -l login system'. The command is run with the full privileges of UUCP; it is responsible for maintaining security.
The dialer configuration files define dialers. By default there is a
single dialer file, named `dial' in the directory
newconfigdir. This may be overridden by the
command in the main configuration file; see section Configuration File Names.
Any commands in the file before the first
dialer command specify
defaults for all the dialers in the file. All commands after a
dialer command up to the next
dialer command are
associated with the named dialer.
uucicodaemon will sleep for one second between attempts to dial out on a modem. If your modem requires a longer wait period, you must start your chat script with delays (`\d' in a send string). The chat script will be read from and sent to the port specified by the
dial-devicecommand for the port, if there is one. The following escape addition escape sequences may appear in send strings:
carriercommand in the port file, \M and \m are ignored. If both the port and the dialer support carrier, as set by the
carriercommand in the port file and the
carriercommand in the dialer file, then every chat script implicitly begins with \M and ends with \m. There is no default chat script for dialers. The following additional escape sequences may be used in
uucicowill require that carrier be on. One some systems, it will be able to wait for it. If the argument is false, carrier will not be required. The default is true.
dtr-toggle boolean boolean
complete-chat. It is equivalent to
complete-chat "" string; this has the effect of sending string to the modem when a call finishes normally.
abort-chat. It is equivalent to
abort-chat "" string; this has the effect of sending string to the modem when a call is aborted.
protocol-parameter character strings
protocol-parametercommand in the system configuration file or the port configuration file; see section Protocol Selection. These parameters take precedence, then those for the port, then those for the system.
half-duplex boolean [ any type ]
If your system has a Berkeley style socket library, or a System V style TLI interface library, you can compile the code to permit making connections over TCP. Specifying that a system should be reached via TCP is easy, but nonobvious.
If you are using the new style configuration files (see section Taylor UUCP Configuration Files), add the line `port type tcp' to the entry in the `sys' file. By default UUCP will get the port number by looking up `uucp' in `/etc/services'; if the `uucp' service is not defined, port 540 will be used. You can set the port number to use with the command `port service xxx', where xxx can be either a number or a name to look up in `/etc/services'. You can specify the address of the remote host with `address a.b.c'; if you don't give an address, the remote system name will be used. You should give an explicit chat script for the system when you use TCP; the default chat script begins with a carriage return, which will not work with some UUCP TCP servers.
If you are using V2 configuration files, add a line like this to `L.sys':
sys Any TCP uucp host.domain chat-scriptThis will make an entry for system sys, to be called at any time, over TCP, using port number `uucp' (as found in `/etc/services'; this may be specified as a number), using remote host `host.domain', with some chat script.
If you are using HDB configuration files, add a line like this to Systems:
sys Any TCP - host.domain chat-scriptand a line like this to `Devices':
TCP uucp - -You only need one line in `Devices' regardless of how many systems you contact over TCP. This will make an entry for system sys, to be called at any time, over TCP, using port number `uucp' (as found in `/etc/services'; this may be specified as a number), using remote host `host.domain', with some chat script.
uucico daemon may be run as a TCP server. To use the default
port number, which is a reserved port,
uucico must be invoked by
the superuser (or it must be set user ID to the superuser, but I don't
recommend doing that).
You must define a port, either using the port file (see section The Port Configuration File),
if you are using the new configuration method, or with an entry in
`Devices' if you are using HDB; there is no way to define a port
using V2. If you are using HDB the port must be named `TCP'; a
line as shown above will suffice. You can then start
`uucico -p TCP' (after the `-p', name the port; in HDB it must
be `TCP'). This will wait for incoming connections, and fork off a
child for each one. Each connection will be prompted with `login:'
and `Password:'; the results will be checked against the UUCP (not
the system) password file (see section Configuration File Names).
Another way to run a UUCP TCP server is to use the BSD
Yet another way to run a UUCP TCP server is to use
inetd to start up
uucico with the `-l'
switch. This will cause
uucico to prompt with `login:' and
`Password:' and check the results against the UUCP (not the system)
password file (you may want to also use the `-D' switch to avoid a
fork, which in this case is unnecessary).
This discussion of UUCP security applies only to Unix. It is a bit cursory; suggestions for improvement are solicited.
UUCP is traditionally not very secure. Taylor UUCP addresses some security issues, but is still far from being a secure system.
If security is very important to you, then you should not permit any external access to your computer, including UUCP. Any opening to the outside world is a potential security risk.
When local users use UUCP to transfer files, Taylor UUCP can do little
to secure them from each other. You can allow somewhat increased
security by putting the owner of the UUCP programs (normally
uucp) into a separate group; the use of this is explained in the
following paragraphs, which refer to this separate group as
uucp program is invoked to copy a file to a remote
system, it will, by default, copy the file into the UUCP spool
directory. When the
uux program is used, the `-C' switch
must be used to copy the file into the UUCP spool directory. In any
case, once the file has been copied into the spool directory, other
local users will not be able to access it.
When a file is requested from a remote system, UUCP will only permit it
to be placed in a directory which is writable by the requesting user.
The directory must also be writable by UUCP. A local user can create a
directory with a group of
uucp-group and set the mode to permit
group write access. This will allow the file be requested without
permitting it to be viewed by any other user.
There is no provision for security for
uucp requests (as opposed
uux requests) made by a user on a remote system. A file sent
over by a remote request may only be placed in a directory which is
world writable, and the file will be world readable and writable. This
will permit any local user to destroy or replace the contents of the
file. A file requested by a remote system must be world readable, and
the directory it is in must be world readable. Any local user will be
able to examine, although not necessarily modify, the file before it is
There are some security holes and race conditions that apply to the above discussion which I will not elaborate on. They are not hidden from anybody who reads the source code, but they are somewhat technical and difficult (though scarcely impossible) to exploit. Suffice it to say that even under the best of conditions UUCP is not completely secure.
For many sites, security from remote sites is a more important consideration. Fortunately, Taylor UUCP does provide some support in this area.
The greatest security is provided by always dialing out to the other site. This prevents anybody from pretending to be the other site. Of course, only one side of the connection can do this.
If remote dialins must be permitted, then it is best if the dialin line
is used only for UUCP. If this is the case, then you should create a
call-in password file (see section Configuration File Names) and let
uucico do its own login prompting. For example, to let remote
sites log in on a port named `entry' in the port file (see section The Port Configuration File), you might invoke `uucico -e -p entry'. This would cause
uucico to enter an endless loop of login prompts and daemon
executions. The advantage of this approach is that even if remote users
break into the system by guessing or learning the password, they will
only be able to do whatever
uucico permits them to do. They will
not be able to start a shell on your system.
If remote users can dial in and log on to your system, then you have a security hazard more serious than that posed by UUCP. But then, you probably knew that already.
Once your system has connected with the remote UUCP, there is a fair
amount of control you can exercise. You can use the
remote-receive commands to control the directories the remote
UUCP can access. You can use the
request command to prevent the
remote UUCP from making any requests of your system at all; however, if
you do this it will not even be able to send you mail or news. If you
do permit remote requests, you should be careful to restrict what
commands may be executed at the remote system's request. The default is
rnews, which will suffice for most systems.
If different remote systems call in and they must be granted different
privileges (perhaps some systems are within the same organization and
some are not) then the
called-login command should be used for
each system to require that they use different login names. Otherwise,
it would be simple for a remote system to use the
and pretend to be a different system. The
sequence command can
be used to detect when one system pretended to be another, but, since
the sequence numbers must be reset manually after a failed handshake,
this can sometimes be more trouble than it's worth.