Linux Network Administrator Manual (12) Chapter 12 Management Taylor UUCP

Linux Network Administrator Manual (12)

2000-07-29 11:22

Publisher: NetBull Readings: 1127 Translation: Zhao Wei gohigh@shtdu.edu.cn Chapter 12 Management Taylor UUCP 12.1 History Review UUCP is the Mike Lesk of the AT & T Bell Lab designated in the late 1970s, used in public A simple dial-up service is available on the telephone line. Because many people who want to have email and usnet news on their own machines still use MODEM to communicate, UUCP is still very popular. Although many implementations running on various types of hardware platforms and operating systems, they are compatible at high degrees. However, although there are many softwares in the past years have become "standard", there is no UUCP software called UUCP. Since the first release in 1976, it has experienced a solid evolution process. Currently, there are two main types, which are different in hardware support and configuration. They all have a variety of implementations, and each implementation has some subtle differences. One of these is the so-called "version 2 UUCP", which is implemented in Mike Lesk, David A. Novitz and Greg Chesson in 1977. Although this is a very old version, it is still often used. The recent implementation of version 2 provides ease of use of updated UUCP types. The second is developed in 1983 and is often referred to as BNU (Basic Networking Tool), Honeydanber UUCP, or referred to as HDB. This name produces the name of the author, P. Honeyman, D. A. Novitz and B. E. REDMAN. HDB takes into account some shortcomings of exclusion version 2 UUCP. For example, there is a new transport protocol and have an independent directory for each site with UUCP communication. The UUCP implementation issued with Linux is Taylor UUCP 1.04, [1] This chapter is discussed based on this release. Taylor UUCP version 1.04 was released in February 1993. In addition to the traditional configuration file, Taylor UUCP can also be compiled into a new style - a.k.a. "taylor" - profile. Recently issued from version 1.05, and will not be integrated into most Linux releases soon. The differences between these versions are mainly on the features you will not use, so you can use the information in this book to configure the Taylor UUCP version 1.05. For Taylor UUCPs included in many Linux issuings, it is usually compiled into a BNU compatible, or uses a Taylor configuration scheme, or between. Because the latter is more flexible, and may be easier to understand than often a BNU configuration file, I will introduce the Taylor configuration scheme. The purpose of this chapter is not to give you a detailed description of the command line option for the uucp command, but give you a summary introduction to how to set up a UUCP site. The first part gives a brief description of how UUCP is remote execution and file transfer. If you are not a complete novice for uucp, you can skip this part and directly to the UUCP configuration file section, which explains various files used to set up UUCP. However, we will assume that you are familiar with the UUCP kit. These programs are UUCP and UUX. For an introduction to these two commands, see the online handbook. In addition to the commonly used UUX and UUCP programs, the UUCP kit also contains a series of commands that are for managing purposes. They are used to monitor UUCP communication through your node, delete old log files or summarize statistical parameters. They will not be made herein because they are parallel with the main task of UUCP. Moreover, they have a good document that can be referred to and is easy to understand. However, there is also a class, which is composed of UUCP's actual "work machine".

They are called UUCICO (here CICO represents copy-in copy-out) and UUXQT- for performing jobs for remote system transmission. 12.1.1 For more information about UUCP For those who want to find the information you want in this chapter, you should read the documentation with the package. This is a TEXINFO file that describes settings using the Taylor configuration scheme. Texinfo can be converted into DVI and GNU information files using Tex and MakeInfo, respectively. If you want to use BNU or even (shuri) version 2 configuration file, there is a good book, "Manage UUCP and UseNet" ([OREILLY89]). I found it very useful. Other good information about UUCP on Linux is Vince Skahan's uuCP-HOWTO, which is scheduled to be delivered to Comp.OS.Linux.announce. Of course, there is also a newsgroup specially discussed UUCP called Comp.mail.uucp. If you have a problem with Taylor uucp, you'd better ask them there, not in the Comp.S.linux group. 12.2 Overview 12.2.1 Summary of UUCP Transport and Remote Executions is a job (JOBS) for understanding UUCP. Each transmission initiated by the user using UUCP or UUX is called a job. It is a command that is executed on a remote system, and a fileset that will be transmitted between sites. Of course, some of them can be omitted. As an example, assuming that you have issued the following command on your host, the command enables UUCP to copy the file NetGuide.ps on the host Pablo, and make it execute the LPR command to print this file. $ uux -r pablo! lpr! NetGuide.ps uucp usually does not immediately call remote systems to perform a job (but you can use Kermit to do). It is temporarily stored. This is called spooling. The directory tree stored in the job is therefore called spool directory and is usually located in / var / spool / uucp. In our example, the job describes information about the remote command (LPR) to be executed, requiring commands of the operation and other items. In addition to this job description, UUCP also needs to store the input file NetGuide.ps. The exact location and naming method of the affix line file can be different, depending on some options for compile. HDB-compatible UUCP typically stores the fake offline file in a directory named / var / spool / uucp / site, where Site is the name of the remote site. When compiled in a TAYLOR configuration, UUCP will create a subdirectory in the spool directory of different types of spiking files in the specified site. In the specified time interval, UUCP will dial the remote system. When it is established with the connection to the remote system, UUCP transmits the file that describes the job, plus all input files. The input job will not be executed immediately, and after the connection is closed, it is closed. This is performed with UuxQT. If there is a job specified to other sites, it also handles the forwarding work of these jobs. To distinguish important and unusual jobs, uucp specifies a grade to each job. This is a single letter, ranges from 0 to 9, A to Z and A to Z, and level from large to small. MAIL usually performs a spherked operation at level B or C, while NEWS performs a spherked operation at a level N. The hete the higher level, the earlier the job transmission. Level can be specified with the -g flag when calling uucp or uux. You can also ban the transmission of a certain level of jobs at a certain period of time. This is called the maximum spool grade allowed during the dialog, the default value is z.

Here, please note that the terminology is ambiguous: a document will be transmitted and is only equal to or higher than the maximum spherker level. 12.2.2 UUCICO's internal working mechanism should be understood why UUCICO needs to know some things here, which gives it a quick description of how it is actually connected to the remote system. When you perform uuCico -s system on the command line, it must first perform a physical connection. The operations are performed on the open connection type - for example, when using a telephone line, it must find an MODEM and dial. On the TCP, it must call gethostByname (3) to convert the name into a network address, find out that the port is to be opened, and the address is bound to the corresponding socket. After this connection is established, the next must pass through an authentication process. This often queries a login name and a possible password consisting of a remote system. This is often referred to as a login chat. The authentication process is performed by the usual Getty / Login kit or is done by UuCico itself on the TCP socket. If the authentication is successful, the remote system will start UUCICO. The local UUCICO copy of the initialized connection is considered as the master, the remote is used as a slave. Next is a Handshake Phase; the main end now issues its own hostname, plus several flags, checks the login license for this hostname, send and receive files, and more. These marks are used to describe the maximum level of the spool file transmitted (and in other things). If enabled, a dialog count will be performed here, or check the serial number. With this feature, both-end sites maintain a count of successful connections, which can be used to compare. If they don't match, the handshake process failed. This is useful for protecting you from predictors. Finally, two UUCICO tried to reach a common transport protocol. This protocol guides the data transmitted, checks consistency and retransmission operation when an error occurs. There are different protocols for different connection types that are supported. For example, the telephone line requires a "security" protocol for the error, and TCP transmission is reliable, so it can be used to use a more effective protocol that does not have to attach an error check. After the handshake phase is completed, the actual transmission phase is started. The transmission is transmitted on the selected protocol driver. The driver generally performs an initialization process associated with the protocol. First, the primary end will send a fake offline level to all files in the queue to remote systems. When it completes the transfer, it will notify the slave, and it can hang from the end at this time. Now you can or agree to hang up, or the dialog is controlled. This is a rule change: now the remote system becomes the master, and the local will become from the end. The new master now sends its files. When completed, two UUCICO exchange the transmission message with each other and turn off the connection. We will no longer be made more detailed description: see the code or any good book for this for this. A very old article is also circulated online, written by David A. Novitz, which gives a detailed description of the UUCP protocol. Taylor UUCP FAQ also discusses some details of the UUCP implementation method. It is regularly delivered to commit.mail.uucp. 12.2.3 UUCICO Command Line Options This section describes some of the most important command line options for UUCICO. For a list of complete command line options, see the UUCICO (1) man page. -S System Call Specifies System (System) unless the call time is limited. -S System unconditionally calls specified (System). -r1 starts UUCICO in the master mode.

This is the default value when -S or -s is given. If there is only this option, the -R1 option will cause UUCICO to try all the systems in SYS, unless received by call restrictions or retry. -r0 Starts UUCICO in a slave mode. This is the default value that is not given in -s or -s. In the route mode, or the standard input / output is assumed to be connected to a serial port, or using the TCP port specified by the -p. -X Type, -X Type Turn on the designated type of debugging. Several types can be specified with a list of comma separates. The following types are effective: Abnormal, Chat, Handshake, Uucp-Proto, Proto, Port, Config, Spool, Execute, Incoming, Outgoing. In order to be compatible with other UUCP implementations, you can replace it with a number, which opens the first N item in the list above. The debug information will be recorded in the / var / spool / uucp file DEBUG. 12.3 UUCP profile Compared to a simple file transfer program, UUCP is designed to automatically handle all transmission operations. Once it is properly set, there is no need to intervene every day. The information required to operate is saved in several configuration files in the / usr / lib / uucp directory. Most of these files are used in dialing operations. 12.3.1 Taylor uucp Introduction To say that uucp is difficult, this is just a conservative statement. In fact it is an intricate issue, and sometimes the confidential format of the configuration file does not make the problem easier. (Although compared to the old format in HDB or version 2, the Taylor format is almost easy to read). In order to give you a feeling of these files, we will introduce you a very important file and observe the samples of these documents. Now we will not explain various details; more accurate descriptions will be given in each of the separate sections below. If you want to set up uucp on your machine, you'd better start from some sample files and gradually adjust the sample file. You can or use the sample files shown below or those that are included in your Linux release. All files described in this section are stored in / usr / lib / uucp or one of the subdirectories therein. Some Linux distributions contain UUCP execution files, which support HDB and Taylor configuration and use different subdirects for each configuration fileset. There is usually a README file in / usr / lib / uucp. In order to make UUCP work normally, these files must be all UUCP users. Some of these files contain passwords and phone numbers, so there should be 600 permission permissions. [2] The most important UUCP profile is / usr / lib / uucp / config, and is used to set up the usual parameters. The most important of these (and now, only) is the UUCP name of your host. In a virtual winery, they use vStout as their UUCP gateway: # / usr / lib / uucp / config - uucp main configuration file hostname vStout Another important configuration file is SYS file. It contains information about all system aspects of the site. This includes site names and information that connects themselves, such as the phone number when using the Modem connection. A typical content called the Pablo site in a Modem will be the interrelationship between the Taylor UUCP configuration file.

# / usr / lib / uucp / sys - name uucp neighbors # system: pablo system pablo time any phone 123-456 port serial1 speted 38400 chat gin: vStout Ssword: Lorca port specifies the port used, and TIME points out it will The moment of being called. CHAT describes the login dialog script - must exchange each other to allow UuCico to log in into the string sequence of Pablo. We will discuss the login script later. The port command does not specify a device-related file such as / dev / cua1, but specifies an entry in the Port file. You can assign these names as you want, as long as these names have a valid reference in the port file. The Port file has information related to the connection. For the Modem connection, it describes the device related files used, the supported speed range and the type of dial-up device connected to the port. The following entrance entries describe / dev / cua1 (ie, known COM2), a Nakwell Modem connected to it, which can run at a speed of up to 38400 bps. The naming method of the entrance entry is to select the name that matches the port name in the SYS file. # / usr / lib / uucp / port - uucp ports # / dev / cur1 (COM2) Port Serial1 Type Modem Device / dev / Cua1 Speed ​​38400 Dialer Nakwell belongs to the Dial Up (DIALER) The information is saved in another file. , Called - you guess: Dial. For each diary type, it basically contains command sequences for issuing dial-up to a remote site, and gives the phone number. Once again, this is given as a dialog script. For example, the entrance entry entry entrance above can look like this: # / usr / lib / uucp / dial - per-dialer information # nakwell modems dimer nakwell chat "" ATZ OK ATDT / TECT "ATZ OK ATDT / T" pointed out MODEM dialog, it is a command string that is sent to MODEM and initialization modem received from MODEM and makes it dials the desired number. The "/ t" sequence will be replaced by UUCICO to the phone number. In order to give you a UUCICO how to handle these profiles, assume that you issue a command on the command line # uuCico -s pablo uuCico's first thing to find Pablo in the SYS file. It sees that it should use the Serial1 port from the Pablo entry entry from the SYS file. The port file tells it that this is a Modem port and has a Nakwell Modem even on that port. UuCico now finds the entry entry describing Nakwell Modem in the Dial file and finds one and opens serial port / dev / cua1 and performs a dialer dialog. That is, it sends "ATZ", waiting to respond "OK", and so on. When you encounter a string "/ T", it is replaced with the phone number (123-456) obtained from the SYS file. After the MODEM returns Connect, the connection is established, and the Modem conversation is over. UUCICO is now returned to the SYS file and performs a login dialog. In our example, it will wait for "login:", then send out its username (Neruda), wait "Password:" prompt and send it a password, "Lorca". After completing the permission certification, the remote will start its own UUCICO. These two UUCICO then enters the handshake stage described in the previous section. The interrelationship between configuration files is also shown in Figure 12.1.

12.3.2 UUCP needs to know what you must collect some information it needs before you start writing a UUCP profile. First, you must know which serial port of your Modem connection is. Typically, (DOS) ports COM1 to COM4 are mapped to device files / dev / cua0 to / dev / cua3. For most releases, such as Slackware, create a chain / dev / modem as a chain to the appropriate CUA * device file, and configure Kermit, Seyon, etc. to use this universal file. In this case, you should also use / dev / modem in your uuCP configuration. The reason is that all dialing programs use so-called Lock files when serial ports are occupied. The names of these locked files are string LCK .. and device file names, such as LCK..cua1. If the program uses a different file name for the same device, they will not recognize their respective lock files. As a result, when they start at the same time, the process will be destroyed. This is not often eventually happening when you use crontab to determine your UUCP call schedule. For more information on setting your serial port, see Chapter 4. Next, you have to find out what your MODEM will communicate with Linux. You must set it to the maximum effective transmission rate you expect. Effective transmission rates may be much higher than your MODEM's original physical transmission rate. For example, many modems sends and receive data at 2400 bps (bit per second). If a compressed protocol such as V.42bis is used, the actual transmission rate may climb to 9600 bps. Of course, if you want to do anything, you will need a phone number of the called system. Similarly, for your remote system, you also need a valid login ID and a possible password. [3] You must also know how to log in into the system clearly. For example, do you need to press the BREAK button before the login prompt appears? It shows login: or user:? This is required for the compilation of the dialog, this dialog script is informing UUCICO how to log in. If you don't know, or if the commonly used dialog is fails, try using terminal programs like Kermit or Minicom, and write down what you have to do. 12.3.3 Site Naming For TCP / IP-based networks, your host must have a name when using a UUCP network. If you just want to simply use UUCP to make your direct dial-up site or in the transfer of files on the local online file, then this name does not need to meet any standard. [4] However, if you use UUCP for Mail or News connections, you should consider registering your name in the UUCP mapping program project. The UUCP mapping plan will be described in Chapter 13. Even if you are just in a domain, you should also consider getting an official UUCP name for your site. People often choose their UUCP name matches their full-scale domain name. If your site's domain name address is swim.twobirds.com, then your UUCP hostname should be SWIM. Consider those UUCP sites that are well known to each other. Of course, you can also use a UUCP name that is completely unrelated to your wholly-owned domain name. However, please be sure not to use unqualified site names in the email address unless you have registered it as your formal uucp name. In the best case, all information that mail to the UUCP host that is not registered will only be quietly lost. If you use a name that has already belonging to other sites, the message will route that site and will bring endless troubles to the mail manager of that site. By default, the UUCP site uses the name of the HostName as the UUCP name of the site. This name is usually set in the /etc/rc.local script.

If your UUCP name is different from your hostname settings, you must use the Hostname option in the config file to tell UuCico's name. This will be explained below. 12.3.4 Taylor Profile Now we will come back to discuss the configuration file. Taylor UUCP Gets information from the following files: config This is a major configuration file. You can define the UUCP name of your site here. SYS This file describes all sites you know. For each site, it specifies the name, call time, dial number (if any), how to log in. Port contains the entry entry entry entry entry in each existence, and the rate of the route and the dialer used. Dial describes the dialer for establishing a telephone line connection. The CALL contains the login name and password used when calling a system. Rarely used. Passwd contains the login name and password that the system may be used when logging in. This file is used only when UuCico has a password check. Taylor profiles are typically composed of rows containing keyword-value. A '#' symbol specifies that this line is not commented until the end. To use the '#' symbol itself, you should use it with a backslash. You can use a lot of options to adjust these profiles. Here we can't discuss all these parameters, but will just discuss several important parameters. With them, you can configure a MODEM-based UUCP connection. Other Sections will describe the necessary amendments that you want to use UUCP on TCP / IP or direct serial lines. Complete references have been given along with the Taylor UUCP original code to be given by TexInfo documents. When you think you have fully configured your UUCP system, you can use the UUCHK tool (located on / usr / limited) to check your configuration. UUCHK reads your profile and prints a detailed report for the configuration value of each system. 12.3.5 Common Configuration Options - Config Files In addition to your UUCP host name, this file usually does not contain additional information. By default, uucp will use the name you set with the hostname command, but explicitly set up the uucp name will be a good attention. The following shows an example file: # / usr / lib / uucp / config - uucp main configuration file hostname VStout can also set up a wide variety of parameters, such as a deacon directory, or anonymous uucp access Permission. The latter will discuss in the back section. 12.3.6 How to inform UUCP Information about other systems - SYS file SYS file describes the information about the remote system to be understood by your machine. A entry is introduced by the System keyword; the subsequent lines are detailed in detail the information about that site until the information between the next SYSTEM instruction is described in detail. Typically, a system entry will define parameters such as telephone numbers and login dialogues. The default values ​​used for all systems were set before the first parameters of the first SYSTEM line. Generally, you have to set information on protocol parameters in the default section. Here, several important fields are described in more detail. The system name system command specifies a remote system. You must specify the correct name of the remote system, not your fictional alias, because UUCICO will compare it with the remote system when you log in. [6] Each system name can only be obvious. If you want to use several configurations for the same system (such as a few different phone numbers that UUCICO should try), you can specify alternates. Alternates will be discussed below. Telephone Number If the remote system is connected via phone line, the Phone field will specify the number of Modem to dial. It can contain tags explained by the dial-up process of UUCICO. One is equal to the symbol means waiting for the second dial tone, a dash generation of a second pause time. For example, some installed calls will stop when you are suspending between the preamble and the phone number.

I don't know about the right English term, just like a privately installed phone in the company. When you want to get out of the line, you must first dial one 0 or 9. Any embedded string can be used to hide information related to the site, such as the part number. Any string such a string uses the Dialcode file to be converted into a dial code. If you have the following Dialcode file: # / usr / lib / uucp / dialcode - Dialcode Translation Bogoham 024881 Coxton 035119 Using these conversions, you can use the phone number like Bogoham7732 in the SYS file, which makes the number become clear and easy to read . Port and speed port and speed options are used as the highest rate that selects the device for calling remote systems and the device should set. [7] A System entry can be used separately or use them simultaneously. When the appropriate device is found in the port file, only those port names and / or the port matching ports are selected. Usually, it is sufficient to use the Speed ​​option. If a serial device is only defined in the port, UUCICO will always choose to a correct, so you only need to give it a desired speed. If you connect a few modems on your system, you usually do not need to specify a specific port, because when you find a few matches, it is trying to find a unused device when UuCico finds a unused device. The login chat, we have already encountered a login dialog script, which inform UUCICO how to log in into the remote system. It consists of a list of desired strings specified by a local UUCICO process and a marker list of sending strings. The purpose is to let the UUCICO wait for the remote machine to send a login prompt, then return to the login name, wait for the remote system to send a password prompt, and send a password. The desired and transmitted string is given alternate. UUCICO automatically supplies the carriage return (Carriage Return Character / R) to any sending string. This way, a simple dialog script will like this OGIN: VStout Ssword: catch22 You will notice that the desired field does not include a complete prompt. This is to be sure that even if the remote system broadcasts login: rather than login:, you can also log in to success. UUCICO also allows certain conditions to be performed, for example, the case where the Getty of the remote machine needs to be reset before issuing a prompt. For this, you can attach a sub-dialog to a lookout string and compensate for a broken number. The sub-dialog will only be performed only if the primary expectation fails, for example, timeout. One way to use this feature is to send a BREAK when the remote site does not display a login prompt. The following example gives a multi-purpose conversation script that can be used in the case where you must press Enter before logging out. "" Tell UUCP Do not wait for any information and continue the next string to send. "" / N / R / D / R / N / C OGIN: -BREAK-OGIN: VSTOUT SSWORD: CATCH22 There are several special strings and escape characters in the dialog script. Here is an incomplete list of legitimate characters in the desired string: "" "empty string. It tells UUCICO Don't wait for anything, and immediately perform the sending process of the next string. / t tab character. / R Enter (Carriage Return) character. / s space character. You need it to join the space in the dialogue. / N wrap. // Sprinkler character. For the transmitted string, in addition to the above characters, the following characters and strings are also legally: EOT Transmission End Characters (^ D) (^ D).) (END OF TRANSSION Character). Break interrupt characters.

/ c is sent to the carriage return of the character string. / d delay in 1 second transmission. / E Allows response (back to ECHO) check. Before UUCICO can continue the dialog, it is read from the device of all the information written. This is very useful when used for Modem dialog (we will encounter below). By default, the response check is off (OFF). / e prohibits response check. / K with Break. / p Pause in a second. Alternates Sometimes, it is very important to have multiple entries for a single system, such as if the system arrives at different MODEM lines. For Taylor UUCP, you can do it by defining a so-called Alternate. In order to use two phone numbers to Pablo, you have to modify it in Sys: System Pablo Phone 123-456 ... Entries As Above ... Alternate Phone 123-455 When calling Pablo, UUCICO will now all dial out the number. 123-456, if it fails, it will be spare. The standby entry maintains all the settings with the main system entry, only the phone number is different. Limiting call time (Restricting Call Times) Taylor UUCP provides a number of methods to allow you to limit the time for remote system calls. The reason for doing this or because the remote host only provides such services, or simply just to avoid the cost of high call time periods. Note that by giving the UUCICO option -s or -f, the call time limit can be overwritten. By default, Taylor UUCP does not allow any time to connect, so you must use some time specifications in the SYS file. If you don't care about call time limit, then you can specify the value Any to the time TIME option in your SYS file. The easiest way to limit the call time is to use the TIME entry, which is specified by a string consisting of a day and time subfield. The days can be any combination of Mo, Tu, WE, TH, FR, SA, SU, or any, never, or weekday WK. The time consists of two 24-hour clock values ​​and is separated by a mesh. They specify the time range of the call. There is no space between the combinations of these tags. Any number of days and time instructions can be combined with commas. For example, Time Mowe0300-0730, FR1805-2000 allows call activities from Monday and Wednesday from 3 pm to 7:30, and Friday at 18:05,000 to 20:00. At the time, the field across midnight, such as Mo1830-0600, which actually represents Monday, between midnight, between 6 o'clock, and at 6:30 pm to midnight. Special time string Any and never are their original:, it means that you can call at any time and you can't call at any time. The Time command has an optional second parameter for describing the retry time in a minute. When an attempt fails to establish a connection, UUCICO will not allow an attempt to dial to the remote host in a certain time interval. By default, UUCICO uses an exponential return scheme, the more the number of repetition failures, the longer the time of the re-trial interval. For example, when you specify a 5-minute retry time, UUCICO will reject the call remote system within 5 minutes from the last failure. The TimeGrade command allows you to attach a maximum spoor offline level on the schedule.

For example, suppose you have the following Timegrade commands in the System entry: TimeGrade N wk1900-0700, Sasu Timegrade C Any This allows only calls to be established, then the fake offline C or higher job (usually, mail is level B or C queuing) can be transferred immediately, and NEWS (usually in the queue in the queue) will only be transmitted at night and weekend. Like TIME, the TimeGrade command will use a minute retest time as a third alternative parameter. However, a bad offline level is: First, the TimeGrade option is applied only to your system's transmission; and the remote system can still transfer anything as you want. You can use the call-timegrade option to explicitly request remote systems to send only jobs above the spool level; however, it will not guarantee that it will follow this request. [8] Similarly, when the remote system call comes in, the TimeGrade field is not checked, so any job waiting for this remote system will be sent out. However, the remote system can clearly request your UUCICO to limit the job that only sends a spool level. 12.3.7 Some devices - PORT file port file Inform UUCICO's existing port. These may be MODEM ports, but other types of ports, such as direct serial line connectivity, and TCP sockets are also supported. Like the SYS file, the Port file consists of various entries that start after the keyword port. This port name can be used in a PORT statement in the SYS file. This name does not have to be unique; if several ports have the same name, uuCico will try each port in order until it finds an idle port. After the port command, you must keep up with the Type statement of the port type. Effective types have modems, direct connection Direct, and TCPs with TCP sockets. If the port command does not exist, the default value of the port type is MODEM. In this section, we will only discuss the MODEM port; TCP ports and direct line connections will be discussed in the subsequent subsections. For MODEM and direct port, you must use the Device instruction to specify the device used to exhale. Usually, this is the name of a device file in the / dev directory, like / dev / cua1. [9] For the mode of the Modem device, the port entry also determines the type of Modem connection on the port. Different types of MODEM require different configurations. Even those who claim that Hayes compatible MODEM is not necessarily true to each other. Therefore, you have to inform UuCico how to initialize Modem and how to make it all desired number. Taylor UUCP Saves the description of all diaphrators in a file called Dial. In order to use any one, you must use the DIALER command to specify the name of the dialer. Sometimes you want to use a modem in a different way, depending on the system you call. For example, when a high-speed MODEM is connected to 14400 bps, some old modems cannot be understood; they just simply interrupt the line rather than negotiating a connection speed, such as 9600bps. When you know that the site DROP uses such a untrusive MODEM, you must set your modem in a different way when you call them. For this, in the port file you require an additional port entry specified for a different dialer. Now you can give this new port a different name, such as Serial1-Slow, and use Port instructions in the DROP system entry of the SYS file. A better way is to distinguish them through the speed they support.

For example, the two port entry entries above the case seem to be like this: # Nakwell modem; connect at high speted port serial1 # port name type modem # modem port device / dev / cua1 # this is com2 speed 38400 # supported speed Dialer Nakwell # normal dialer # NakWell modem; connect at low speed port serial1 # port name type modem # modem port device / dev / cua1 # this is COM2 speed 9600 # supported speed dialer nakwell-slow # do not attempt fast connect system for site drop The entrance entry will give serial1 as a port name, but only use it with 9600 bps. At this point, UUCICO will automatically use the second port entry entry. All sites with 38400 bps speeds in the system entry will be used to use the first port entry call. 12.3.8 How to Dial - Dial File Dial file describes how many dialing devices (diaphrators) are used. Traditionally, UUCP only talks about the dialer rather than modem, because in the early days, only one (expensive) dialer is actually realistic. Today, most Modem has built-in dial support, so this difference has some confusion. However, different diaphocons or modems require different configurations. You can describe each of them in the Dial file. Each entry in Dial begins with a Dialer command given the dialer name. In addition to this, the most important entry is the Modem dialogue specified by the chat command. Similar to the login conversation, it is transmitted from a series of UUCICO to the dialer and the return response string it expects. It is usually used to reset the Modem to a certain state and dial. The following dialer envelope is a typical modem conversation of Hayes compatible Modem: # Nakwell Modem; Connect At High Speed ​​Dialer Nakwell # Dialer Name chat "" ATZ OK / R Ath1eoQo OK / R ATDT / T Connect Chat-Fail Busy The Chat-Fail Error Chat-Fail No / Scarrier DTR-Toggle True Modem dialog starts with empty string "". Next UUCICO will send the first command (ATZ). ATZ is a hayes command to reset the MODEM. Then wait for the MODEM to send back OK, then send the next command to turn off the local back, and so on. UUCICO issued a dial command (ATDT) after the MODEM returns OK again. The escape character sequence / t in this string will replace the phone number within the system entry in the SYS file. Thereafter, UUCICO waits for MODEM to return Connect, which means that the remote MODEM has successfully established. Often, the connection of Modem and remote systems will fail, for example, the remote system is talking to other people and the line is busy. In this case, Modem will return some error information to point out the cause of failure. The Modem dialog is no capability to identify this message; UUCICO will continue to wait for the expected string until the timeout. Therefore, UUCP log files will only display a fuzzy "Timed Out In Chat Script" information rather than true reasons. However, Taylor UUCP allows you to tell UUCICO with this chat-fail command to use the above Chat-fail command.

When the MODEM conversation is executed, when UuCico detects a chat-fail string, it will give up this call and record the error message in the UUCP log file. The last command shown in the above sample example informs UUCP to convert the signal of the DTR line before starting the Modem dialog. Most Modems are configured to interrupted the line when the DTR line signal is detected, and enter the command mode. [10] 12.3.9 TCP uses uucp to listen to a little absurd, but use UUCP to transfer data on TCP is not a bad idea, especially when transmitting a lot of data such as USENET NEWS. On TCP-based links, News typically use NNTP protocols to exchange, requests and sending articles are performed separately, no compression is not performed. Optimization. Although this applies to large sites with several parallel feeding functions, this technique is not suitable for receiving a small site of NEWS using ISDN and other slow connections. These sites typically want to combine the advantages of sending NEWS in conjunction with TCP, and can overload data compression and only very small overload. A standard method for batching these data is to use UUCP on TCP. In SYS, you have to specify a system to call by TCP: system gm address news.groucho.edu time any port tcp-conn chat ogin; vStout word; clouseau address command gives the host's IP address, Or it's all domain name. The corresponding port entry will be: Port TCP-Conn Type TCP Service 540 This entry indicates that a TCP connection will be used when a SYS entry refers to using TCP-CONN, and UUCICO will attempt to connect to the TCP network port 540 of the remote host. This port is the default port number of the UUCP service. In addition to the port number, you can also give the service command a symbol port name. The port number corresponding to this name will be found in / etc / services. The universal name of the UUCP service is uucpd. 12.3.10 Use Direct Connection Suppose You use a cable to connect your system vStout and Tiny directly. Very similar to the situation using MODEM, you must write a system entry in the SYS file. Determine the port command of the serial port Tiny is connected. System Tiny Time Any Port Direct1 Speed ​​38400 Chat Ogin; Cathcart Word; Catch22 In the port file, you must describe the serial port directly to the direct connection. No Dialer entry is required because there is no need to dial. Port Direct1 Type Direct Speed ​​38400 12.4 UUCP can do with could not do - Adjustment Permissions 12.4.1 Commands UUCP tasks are to copy files from a system to another, and request the appropriate command on the remote host. Of course, as an administrator who wants to control the permissions to other systems - allowing them to perform any commands on your system, it is definitely not a good idea. By default, the only commands that Taylor UUCP allow other systems to execute on your machine are RMAIL and RNEWS, which are usually used to exchange email and usenet news by UUCP. The default search path for UUXQT is a compile time, usually contains / bin, / usr / bin and / usr / local / bin. If you want to change the command set that can perform a specific system, you can use the Commands keyword in the SYS file. Similarly, the search path can be changed with a command-path statement.

For example, in addition to the RMAIL and RNEWS commands, you may also want to allow the Pablo system to perform RSMTP commands: [11] System pablo ... Commands RMail RNEWS RSMTP 12.4.2 File Transfer Taylor UUCP also allows you to fine tune the transfer of files very detailed. In an extreme case, you can prohibit the transmission of to / from a particular system. Simply set the request to NO, the remote system cannot draw files from your system or you cannot send any files to your system. Similarly, by setting the Transfer to NO, you can prohibit your users from transferring files to a system or pass files from a system. By default, local and remote users are allowed to upload and download files. In addition, you can configure a directory for file copy. Typically, you will want to limit the access to a remote system to a directory structure, but still allow your users to send files from their home directory. Often, remote users are only allowed to receive files from public UUCP directory / var / spool / uucppublics. This is a traditional place to place public documents; very like FTP services on the Internet. It is usually used to indicate. Therefore, Taylor UUCP provides four different commands to configure a directory for sending and receiving files. They are local-send, which specifies the user to request a directory list that can send a file from it; local-receive, which gives the user to request a list of directories that the UUCP receives files; Remote-send and Remote-Receive, for external systems Do a similar job. Consider the following example: system pablo ... local-send / home ~ local-received ~! ~ / All / incoming! ~ / Receive remote-receive ~ / incoming local-send command allows your host Users send any files in the / home and the public uucp directory to Pablo. The local-receive command allows the user to place the received file in a fully writable Receive directory in uuCppublic or in any full-writable directory under the / home. The remote-send command allows Pablo to get files from / var / spool / uucppublic, and in addition to files in Incoming and Receive directories. This is pointed out by placing an exclamation point before the corresponding catalog. At the end, the last line allows Pablo to upload any files into incoming. One of the serious problems using the UUCP transfer file is that it only allows the received file to be used in a fully writable directory. This may attract some users to set traps for other users, and the like. However, there is no way to prevent this problem unless UUCP file transfer is prohibited. 12.4.3 Forwarding UUCP provides mechanisms that make other systems perform file transfer in accordance with your requirements. For example, this allows you to get a file from Uchile from Uchile and send it to your system. The following command will complete this task: $ uucp -r seci! Uchile! ~ / Find-ls.gz ~ / uchile.files.gz This technology is called forwarding. In the above example, the use of forwarding may be that SECI has a UUCP access to Uchile, but your system is not. However, if you run a UUCP system, you will want to limit the forwarding services to a few hosts you trusted, so as to avoid downloading a newest X11R6 source version and spends an amazing phone fee. By default, Taylor UUCP does not allow forwarding activities. In order to start forwarding a particular system, you can use the forward command.

This command specifies a list of sites that can request your system for forwarding jobs. For example, in order to allow Pablo request file from the Uchile, SECI's UUCP administrator must add the following lines of content in the SYS file: ############ #pablo System pablo ... forward uchile ############ # uchile system uchile ... Source:

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