LLPPRRnngg TTuuttoorriiaall

                _P_a_t_r_i_c_k _P_o_w_e_l_l_" _"_<_p_a_p_o_w_e_l_l_@_s_d_s_u_._e_d_u_>_"


                               _A_B_S_T_R_A_C_T


               This  is  a  tutorial on the installation and
          configuration of the LPRng software.  The  various
          _m_a_n  pages  provide  details  on each of the LPRng
          components and should be consulted while  proceed-
          ing  through  the  tutorial.  The following topics
          are covered: setting up  and  testing  a  printcap
          file;   setting   up  and  testing  authorization;
          accounting; setting up network  databases;  debug-
          ging problems.



     11..  IInnttrroodduuccttiioonn

          This  tutorial  is  an introduction to the installation
     and testing of the LPRng software.  It assumes that you  are
     an  oridinary  user,  and  that you have source to the LPRng
     code.  Part of the LPRng distribution is a  _t_e_s_t  configura-
     tion  that  allows  you to perform all of the tutorial exer-
     cises as an ordinary user.  The  following  topics  will  be
     covered.

     1.   Setting up the TESTSUPPORT tutorial system.

     2.   Basic Management Functions using LPC

     3.   Creating  a printcap file for the LPRng client programs
          such as llpprr, llppqq, and llppcc.

     4.   Server (printer) printcap information and spool queues.

     5.   Permissions and authorizations.

     6.   Setting up a general permissions file.

     7.   Setting up a per printer permissions file.

     8.   Basic accounting.

     22..  TTEESSTTSSUUPPPPOORRTT

          A  simple  set of test and support files is provided in
     the TESTSUPPORT directory of the LPRng distribution.   These









                                  -2-


     files,  when  processed and installed in the /tmp directory,
     will create a simple user level printer spooler system.

          LPD         - copy of spool directories
          Makefile    - generation and installation
          clearlog    - shell script to clear log files
          dbserver.sh - prototype database server
          filter.sh   - prototype shell based filter
          lpd.conf.proto  - prototype configuration file
          common.conf.proto   - prototype configuration file
          lpd.perms.proto - prototype permissions file
          main.c      - prototype C based filter
          makedb      - database creation script
          printcap.proto  - prototype printcap file


          To install the files, carry out the following procedure
     in the TESTSUPPORT directory.

          CSH -
              setenv HOST _f_u_l_l_y _q_u_a_l_i_f_i_e_d _h_o_s_t _n_a_m_e
              setenv USER _u_s_e_r_i_d
              setenv LPD_CONF /tmp/LPD/lpd.conf
              path=( /tmp/LPD $path )

          Bourne Shell
              HOST=_f_u_l_l_y _q_u_a_l_i_f_i_e_d _h_o_s_t _n_a_m_e
              USER=_u_s_e_r_i_d
              LPD_CONF=/tmp/LPD/lpd.conf
              export HOST USER LPD_CONF
              PATH=/tmp/LPD:$PATH

          make


          To check that the installation was successful, the com-
     mand lpd -D2 -F should produce output similar to the follow-
     ing.

























                                  -3-


          papowell@taco:70>lpd -D2 -F
          Sep 17 16:13:17 lpd [3665]  *** Get_debug_parms ***
          Sep 17 16:13:17 lpd [3665]  debug: 2
          Sep 17 16:13:17 lpd [3665]  test: 0
          Sep 17 16:13:17 lpd [3665]  remote: 0
          Sep 17 16:13:17 lpd [3665]  log: <NULL>
          Sep 17 16:13:17 lpd [3665]  *** <END> ***
          Sep 17 16:13:17 lpd [3665]  main: Configuration file '/tmp/LPD/lpd.conf'
          Sep 17 16:13:17 lpd [3665]  seteuid_wrapper: Before RUID/EUID 118/118,
          Sep 17 16:13:17 lpd [3665]  seteuid_wrapper: After uid/euid 118/118
          Sep 17 16:13:17 taco lpd [3665]  Getprintcap: paths '/tmp/LPD/printcap....
          Sep 17 16:13:17 taco lpd [3665]  Printcap file '/tmp/LPD/printcap....
          Sep 17 16:13:17 taco lpd [3665]  Get_perms: /tmp/LPD/lpd.perms.taco.sdsu.edu
          Sep 17 16:13:17 taco lpd [3665]  Permissions file '/tmp/LPD/lpd....
          Sep 17 16:13:17 taco Do_queue_jobs [3667]  t1: Open_log: log file log
          Sep 17 16:13:18 taco Do_queue_jobs [3668]  t2: Open_log: log file log
          Sep 17 16:13:19 taco Do_queue_jobs [3669]  t4: Open_log: log file log
          ...


     33..  LLPPQQ

          The  lpq  program displays the current status of one or
     more spool queues.

     1.   In one window, start the LPD server using lpd -F.

     2.   In another window, run the lpq program.  You should see
          a status display similar to the following:

     Printer: t1@taco 'Test Printer 1'
       Queue: 9 printable jobs
       Warning: 1 held jobs in queue
       Server: pid 4537 active, Unspooler: pid 4538 active
       Status: printing 'cfA637taco', sending FF after banner at 18:29:54
       Status: printing job 'cfA637taco data file 'dfA637taco', format 'f' at 18:29:54
       Status: printed 0% of 15 bytes at 18:29:54
       Status: printed all 15 bytes at 18:29:54
      Rank  Owner           Class Job Files                           Size Time
     active papowell@taco       A 637 VERSION                           15 18:27:28
     2      papowell@taco       A 004 VERSION                           15 18:27:27
     3      papowell@taco       A 007 (stdin)                            5 18:27:27
     4      papowell@taco       A 067 VERSION                           15 18:27:27
     5      papowell@taco       A 070 VERSION                           15 18:27:27
     6      papowell@taco       A 343 VERSION                           16 18:27:28
     7      papowell@taco       A 672 VERSION                           15 18:27:28
     8      papowell@taco       A 692 VERSION                           15 18:27:28
     9      papowell@taco       A 336 VERSION                           15 18:29:55
     hold   papowell@taco       A 335 VERSION                           15 18:27:27
     error  papowell@taco       A 002 ERROR: cannot open '/tmp/LPD/t1/dfA003taco'
     error  papowell@taco       A 003 ERROR: cannot open '/tmp/LPD/t1/dfA003taco'
     error  ???@???             A 001 ERROR: empty control file 2 mins old











                                  -4-


          Try running lpq -a; this will display the status of all
     spool queues.  The command lpq -t3 -c will display the  sta-
     tus,  sleep  for 3 seconds, and then clear the screen before
     redisplaying status.

     44..  LLPPRR aanndd LLPPRRMM

          The lpr program spools files to the  output.   Try  the
     following commands:

          echo hi | lpr
          lpq


     The  status  display  will  show  your spooled job.  Now try
     spooling several jobs:

          echo hi | lpr
          echo hi | lpr
          echo hi | lpr
          echo hi | lpr
          lpq


     You can remove a spooled job by using: lprm _j_o_b_n_u_m_b_e_r.   Try
     removing one of the jobs in the spool queue.  If you want to
     remove all jobs, just use lprm  without  a  job  number;  by
     default it removes all of your jobs.

     55..  LLPPCC

          The  lpc  program displays the current status of one or
     more spool queues.

     1.   In one window, start the LPD server using lpd -F.

     2.   The lpc program can run in interactive  or  line  mode.
          We  will  first run it in interactive mode.  In another
          window, run the lpc program.  You should see  a  status
          display similar to the following:

               lpc >


          Try  entering  the  help command: lpc > help; this will
     display the help information.

















                                  -5-


     usage: lpc [-Ddebuglevel] [-V] [-Pprinter] [commands]
      with no commands, reads from stdin  -Pprinter    - specify printer
       -V           - increase information verbosity
       -Ddebuglevel - debug level
      commands:
      abort   (printer[@host] | all)  - stop server
      autohold (printer[@host] | all)  - autohold on
      disable (printer[@host] | all)  - disable queueing
      debug   (printer[@host] | all) debugparms - set debug level for printer
      enable  (printer[@host] | all)  - enable  queueing
      hold    (printer[@host] | all) (name[@host] | job | all)* - hold job
      kill    (printer[@host] | all)  - stop and restart server
      lpd [HUP]  - get LPD PID, signal it to reread printcap and configuration
      lpq (printer[@host] | all) (name[@host] | job | all)*     - invoke LPQ
      lprm (printer[@host] | all) (name[@host]|host|job| all)*  - invoke LPRM
      noautohold (printer[@host] | all)  - autohold off
      printcap (printer[@host] | all) - report printcap values
      quit                            - exit LPC
      redirect (printer[@host] | all) (printer@host | off )*    - redirect jobs
      release  (printer[@host] | all) (name[@host] | job | all)* - release job
      reread                          - LPD reread database information
      start   (printer[@host] | all)  - start printing
      status  (printer[@host] | all)  - status of printers
      stop    (printer[@host] | all)  - stop  printing
      topq    (printer[@host] | all) (name[@host] | job | all)* - reorder job


          The lpc command can be used to start and stop printing,
     spooling,  and  redirect  jobs to other queues.  By default,
     most commands work on the currently selected printer,  which
     is the users default printer or the last selected printer.

     55..11..  SSttaattuuss RReeppoorrttss

          The  status  command  can be used to show the status of
     printers.

     lpc >status all
     Printer              Printing Spooling Jobs  Server   Slave Redirect Debug
     t1@taco               enabled  enabled    3    none    none
     t2@taco               enabled  enabled    0    none    none
     t3@taco               enabled  enabled    0    none    none
     t4@taco               enabled  enabled    0    none    none
     t5@taco               enabled  enabled    0    none    none
     t6@taco               enabled  enabled    0    none    none
     t3@taco               enabled  enabled    0    none    none


          The status display shows the name of the  printer,  its
     print  and spooling status, the number of jobs in the queue,
     if there is a server process active, and if there is a slave
     process  for  the  server process.  The redirect field indi-
     cates if the queue is  being  redirected  to  another  print
     queue and the debug field is the current debugging level set









                                  -6-


     by the lpc command.

     55..22..  SSttaarrttiinngg aanndd SSttooppppiinngg PPrriinnttiinngg aanndd SSppoooolliinngg

          The _s_t_a_r_t and _s_t_o_p commands can be used  to  start  and
     stop printing.

     1.   Enter the command stop t1, status, start, and status as
          shown below.

     lpc >stop t1
     t1 stopped
     lpc >status
     Printer              Printing Spooling Jobs  Server   Slave Redirect Debug
     t1@taco              disabled  enabled    3    none    none
     lpc >start
     t1 started
     lpc >status
     Printer              Printing Spooling Jobs  Server   Slave Redirect Debug
     t1@taco               enabled  enabled    3    none    none


          The enable and disable commands can be used  to  enable
     or disable spooling to the queue in a similar manner.

     lpc >disable t1
     t1 disabled
     lpc >status
     Printer              Printing Spooling Jobs  Server   Slave Redirect Debug
     t1@taco               enabled disabled    3    none    none
     lpc >enable t1
     t1 enabled
     lpc >status
     Printer              Printing Spooling Jobs  Server   Slave Redirect Debug
     t1@taco               enabled  enabled    3    none    none


     55..33..  LLPPQQ aanndd LLPPRRMM CCoommmmaannddss

          For  convenience,  the lprm and lpq commands are avail-
     able in interactive mode.  This allows jobs  to  be  removed
     from  a  print queue and the status of the print queue to be
     viewed after performing commands.

     55..44..  KKiilllliinngg aanndd AAbboorrttiinngg PPrriinntt QQuueeuuee

          The abort and kill commands are used to kill of  print-
     ing of a job.  The kill command will perform an abort opera-
     tion followed by a start operation.

          The abort command is useful when a job is being printed
     and  needs  to  be  restarted, but at a later time using the
     start command.  The kill command is useful when a job can be
     immediately restarted.









                                  -7-


     55..55..  TTOOPPQQ -- CChhaannggiinngg jjoobb pprriioorriittyy

          The topq command can be used to reorder the priority of
     user jobs.  Jobs that have their priority  altered  will  be
     printed  before  jobs  that  have not.  Updated jobs will be
     printed in last updated, first out order.

          For example, the command topq root will have all of the
     root  users jobs printed first, starting with the oldest job
     in the queue.

     55..66..  HHoolldd,, AAuuttoohhoolldd,, aanndd RReelleeaassee

          The hold, autohold, noautohold,  and  release  commands
     are  used  to  temporarily prevent a job from being printed.
     The hold command is used to hold a job and the release  com-
     mand to release it.

          The autohold option can be enabled in the printcap file
     using the :ah: printcap field.  If autohold is enabled, then
     all  jobs will be held until released using the release com-
     mand.  The interactive autohold command can be used to over-
     ride  the  printcap information.  The status of the autohold
     option is recorded in the spool queue control file and  will
     persist  over  system  restarts.  Autohold can be turned off
     using the noautohold command.

          When a job is released  the  printer  may  need  to  be
     started if it is disabled.

     55..77..  JJoobb aanndd QQuueeuuee RReeddiirreeccttiioonn

          The  move  and  redirect commands are used to move jobs
     between different queues.

          The move command will move a selected set of jobs to  a
     new  queue.   For  example, move t1 root t2 will move all of
     the jobs on printer t1 submitted by root to the t2  printer.

          The redirect command will cause all jobs submitted to a
     particular spool queue to be forwarded to the  new  printer.
     The redirect off command will turn redirection off.

     55..88..  DDiiaaggnnoossttiicc CCoommmmaannddss -- ddeebbuugg,, llppdd,, rreerreeaadd,, pprriinnttccaapp

          The  debug,  lpd,  and  lpq  commands are available for
     diagnostic purposes.

          The debug command allows the adminstrator to set debug-
     ging information and values for a specific spool queue.  For
     example, debug 7,remote=5,log=/tmp/x would set debugging  to
     level 7, the remote flag to 5, and send debugging log infor-
     mation to the  /tmp/x  file.   The  debug  command  with  no
     options will turn all debugging options off.









                                  -8-


          The  lpd command will print the process ID (PID) of the
     LPD server process.  The  reread  command  will  send  it  a
     SIGHUP signal, causing it to reread the various databases.

          The  printcap command will cause the printcap entry for
     the specified printer to be returned.  This is  useful  when
     trying  to  determine  the actual values of a printcap entry
     being used by the LPRng software.

     66..  CCoommmmaanndd LLiinnee IInntteerrffaaccee

          The command line interface is identical to the interac-
     tive  interface,  but  only  allows  a  single command to be
     entered at a time.  For example: lpc status all  will  print
     the status of all the printers, and lpc start all will start
     all printers.

     77..  LLPPRRMM

          The lprm program is used to remove jobs from the  spool
     queues.   For  the  following exercises, we will temporarily
     stop printing, and submit jobs.

     1.   In one window, start the LPD server using lpd -F.

     2.   Temporarily stop printing for all spool queues.

               lpc stop all


     3.   Submit a set of jobs to a printer.

               echo hi |lpr -Pt1
               echo hi |lpr -Pt1


     4.   Display the queue status using lpq -a.

               Printer: t1@taco 'Test Printer 1' (printing disabled)
                 Queue: 5 printable jobs
                 Warning: no server present
                 Status: finished operations at Sun Mar  3 13:51:49 1996
                Rank  Owner           Class Job Files                           Size Time
               1      papowell@taco       A 050 (stdin)                            3 13:53:39
               2      papowell@taco       A 068 (stdin)                            3 13:55:41
               3      papowell@taco       A 075 (stdin)                            3 13:55:46


     5.   Try removing one of the jobs using lprm _j_o_b_n_u_m_b_e_r;  for
          example lprm 050.

     6.   Try using lprm _u_s_e_r_n_a_m_e to remove all jobs submitted by
          a particular user.










                                  -9-


     7.   If you want to remove all jobs in a queue and you  have
          control permissions on the queue, you can use lprm all.

     8.   The -a (all) option will try to  remove  the  specified
          jobs  from all printers.  Try lprm -a all to remove all
          jobs for all users.

     88..  PPrriinnttccaappss aanndd CCHHEECCKKPPCC

          The checkpc program can be used  to  validate  printcap
     entries and to set permissions and ownerships on the various
     printcap  files.   The  following  is  a  set  of  exercises
     intended to show the use of the checkpc program.

     9.   Stop  the  lpd  server  by sending it a kill signal.  A
          quick method of doing this is:

               kill `ps -aux |grep lpd | awk '{print $2 }'`


     10.  Run the checkpc program.  The following is typical out-
          put.

                LPRng version LPRng-2.2.0
                Get_perms: permissions file '/tmp/LPD/lpd.perms.taco.sdsu.edu'
                Printcap file '/tmp/LPD/printcap.taco.sdsu.edu'
                Printcap file '/tmp/LPD/lpd_printcap.taco.sdsu.edu'
                LPD lockfile '/tmp/LPD/lpd.lock.taco.sdsu.edu'
                  checking file '/tmp/LPD/lpd.lock.taco.sdsu.edu'
                t1: Checking printcap entry 't1'
                t1:   checking file '/tmp/LPD/t1/control.t1'
                t1:   checking file '/tmp/LPD/t1/status.t1'
                t1:   checking file '/tmp/LPD/t1/log'
                t1:   checking file '/tmp/LPD/t1/accnt'
               checkpc: Warning - permissions of '/tmp/LPD/t1/cfA001taco' are 0644, not 0600
                t1: Checking log file '/tmp/LPD/t1/log'
                t1:    log file 12060 bytes long: no truncation


     11.  Now  try  using  the -f (fix) option to set permissions
          and ownership.

               checkpc -f


          Permissions and ownership will be corrected.

     12.  As the lpd server executes, it  will  put  output  into
          log,  status,  and accounting files in the spool direc-
          tory.  The checkpc -t _s_i_z_e command will truncate  these
          files  to _s_i_z_e bytes.  For example, checkpc -t 2k trun-
          cate these files to less than 2K bytes.  Use this  com-
          mand to truncate the log files.










                                 -10-


     99..  llppdd..ppeerrmmss FFiillee aanndd  PPeerrmmiissssiioonnss

          The  lpd server uses the lpd.perms file to control user
     access to services.  The following is an example permissions
     file.

          # Sample permissions file
          DEFAULT ACCEPT
          # Root on server can do control operations
          ACCEPT SERVICE=C SERVER USER=root
          # The specified user on the server can do control operations
          ACCEPT SERVICE=C SERVER USER=_u_s_e_r
          # Do not allow any other users to do control operations
          REJECT SERVICE=C
          # Job Removal can be done by the same user on the originating host
          ACCEPT SERVICE=M SAMEHOST SAMEUSER
          # Also by root on the server
          ACCEPT SERVICE=M SERVER USER=root
          # Reject all other requests
          REJECT SERVICE=M
          # Reject requests from subnet 130.191.25.0 (24 bit Subnet mask)
          REJECT IP=130.191.25.0/255.255.255.0
          # or REJECT IP=130.191.25.0/24
          # Printer t1: Accept all requests
          PRINTER=t1 ACCEPT


          The man page for lpd.perms.  has a detailed description
     of the various fields and entries.  Each line in the permis-
     sions  file  is  a  test  that  is performed against various
     information associated with a user request.  The  tests  are
     applied  in  sequence  until a match is found; the ACCEPT or
     REJECT keyword specifies  of  the  request  is  accepted  or
     rejected.

          The  DEFAULT keyword specifies the default action if no
     explicit match is found.

          In addition to the main permissions  file,  each  spool
     queue  can  have an additional set of permissions tests that
     can be applied to requests that have been  accepted  by  the
     main permissions file.

          The  SERVICE  tag specifies the type of service for the
     match.  Note that not all service  requests  have  the  same
     amount  of  information to be tested.  This is a consequence
     of the protocol used to send requests  to  the  server.   In
     addition,  the X (connection) request is applied to all con-
     nections, and can be used to restrict  requests  to  only  a
     limited range of host systems.

          When constructing a permissions file, the most specific
     tests should be applied first, then the most  general.   The
     REJECT  tests should precede the ACCEPT, and a default for a









                                 -11-


     particular action should immediately  follow.   Here  are  a
     suggested set of exerises for the reader.

     13.  Modify  the permissions file so that print requests and
          job from user are rejected.  Answer:

               REJECT SERVICE=R,P USER=_u_s_e_r


     14.  Modify the permissions file to allow only hosts in  the
          IP  address submask 130.191.130.0/255.255.255.0 to have
          access.  Answer:

               REJECT SERVICE=X NOT IP=130.191.130.0/255.255.255