Provided by: super_3.30.3-2_amd64 bug

NAME

       super.tab - database of restricted commands for super(1)

DESCRIPTION

       The  super.tab  file  contains the restrictions on who can execute commands with super(1).
       It may also contain options that modify the uid and/or gid under which a command  is  run;
       the  list  of  environment variables that are discarded before executing a command, and so
       on.  The reader is expected to be familiar with the super(1) man page.

       If you are trying to avoid reading this lengthy man page, you need to know  a  few  simple
       rules.   First,  for a user to successfully execute a command by typing super commandName,
       the minimum entry in the super.tab is something like
            commandName   FullPathToCommand  userName
       For example, the entry
            cdmount   /usr/local/bin/cdmount  wally,dolly
       says that users wally and dolly may execute the /usr/local/bin/cdmount program  by  typing
       super cdmount.

       Second,  when  you  define  options  in  the super.tab file, remember that all options are
       orthogonal to each other, and it doesn't matter in what order they  appear  on  a  control
       line.   Third,  global  options (defined on a :global or :global_options line) take effect
       immediately after the defining line, are valid until the end of the input or  until  there
       is  a  countermanding  global option or pattern, and are overridden by local (per-command)
       options, which are defined on a regular control line.

       Although super has a great many options that you can set inside the super.tab  file,  none
       of  them  are required for security, so you don't have to be intimately familiar with this
       entire document in order to use super securely.  The most important options that you  will
       probably  want  to  use  are  (a)  a  logging option like logfile=xxx or syslog=y; and (b)
       patterns=shell, so that the default  regular-expression  interpretation  of  wildcards  is
       changed to the more convenient shell-style glob patterns.

       Unless  modified  with  options  in  the  super.tab  file,  super  executes commands using
       effective uid root; unchanged real uid and gid; no  supplementary  groups;  no  open  file
       descriptors  save 0, 1, and 2; no environment variables except a few with safe values (see
       super(1)); and signal handling reset to the default.

       When super uses a command from a user-supplied super file (.supertab in  the  user's  home
       directory)  these  rules  are  modified: the real and effective uid and gid are set to the
       owner of the .supertab file, and the supplementary groups are  set  to  the  user's  login
       groups.

       If  the special supplementary file named super.init exists, it is implictly include at the
       start of super.tab and every .supertab file.  The file resides in the  same  directory  as
       super.tab  and  must  be  owned  by  root,  and should be world-readable.  This provides a
       uniform configuration file  applied  to  every  super-executed  command.   Note  that  the
       configuration  file  should  contain  entries  that  are  appropriate  for use in both the
       super.tab file and any per-user supertab file.  It is not a good idea to include  commands
       in  the  super.init  file.   The  variable IS_USERTAB is defined to be ``yes'' if super is
       processing a per-user .supertab file, and ``no'' otherwise.  The following pair of entries
       could  be  used in a super.init file to allow different initialization for regular use and
       per-user use:

              :if $IS_USERTAB == yes    :include /etc/super.init.per-user
              :if $IS_USERTAB != yes    :include /etc/super.init.as-root

       (The use of variables and conditional expressions is  explained  below,  in  the  sections
       Variables and Conditionally-included Control Lines, respectively.)

       The super.tab file is formatted as a series of control lines of the form

            CmdPat  FullPath \
                         Options PermittedUsers PermittedTimes
       or
            CmdPat1::FullPath1 CmdPat2::FullPath2 ... \
                         Options PermittedUsers PermittedTimes
       or
            :BuiltinCmd arguments

       The  Options,  PermittedUsers,  and PermittedTimes may be mixed together in any order.  At
       least one PermittedUsers field is required, but neither  Options  nor  PermittedTimes  are
       required.  For each control line, Super matches the following:

              • the user-entered command to a CmdPat;

              • the {user,group,host} triplet to a PermittedUsers entry; and

              • the current time to a PermittedTimes entry (the default permits any time).

       If  these conditions are not satisfied, super ``falls through'' and tries the next control
       line.

       For example, the entry

              renice /etc/renice jack@hill jill@bucket time~8-17

       specifies that between hours 8:00 and 17:00, user Jack can  renice  any  process  on  host
       hill, and user Jill can do so on host bucket, by simply typing super renice <args>  .

       Control  lines  begin in column 1, and the fields are whitespace-separated.  Note that you
       can either use a single CmdPat and FullPath, separated by whitespace, or  you  can  use  a
       series of them in one control line by putting `::' between each CmdPat and FullPath pair.

       Whitespace  may be included in a field by enclosing text in single- or double-quotes.  The
       quoting is shell-like, in the sense that quotemarks don't  have  to  surround  the  entire
       field,  and  you  can  switch  between  quotemark  types in a single entry.  For instance,
       X"a b"Y'd e' is equivalent to "Xa bYd e".  Comments begin with a `#' and continue  to  the
       end of a line.

       There can also be blank or comment lines without any control data.

       A  control  line may be continued by preceding the newline with a backslash, and indenting
       the continuation line with whitespace.  When the multiple-line entry  is  read,  the  text
       just  before  the  backslash-newline  is not modified (any whitespace before the backslash
       will be kept), and the backslash-newline-whitespace sequence is either eliminated entirely
       or  treated  as whitespace.  The rule is simple: following a letter, digit, or underscore,
       it is treated as whitespace.  Otherwise, it is eliminated.  This means that

              Cmd  File  user1\
                         user2\
                         user3

       is equivalent to

              Cmd  File  user1 user2 user3

       On the other hand,

              Cmd  File  {user1,\
                         user2,\
                         user3}

       is equivalent to

              Cmd  File  {user1,user2,user3}

       That is, the sensible interpretation is done in both cases.

       The indentation requirement for continuation lines helps super catch typos.  Comments  may
       be  placed  before each backslash-newline pair, not just at the end of a continued control
       line.

The CmdPat Field

       In response to the user typing

              super cmd [ args ],

       the cmd is searched for in the super.tab file.  The cmd is matched  against  each  pattern
       CmdPat.

       Basic Use: Simple Command Patterns without Wildcards.

       Typically,  a  CmdPat  just  uses  plain  characters  without any special pattern-matching
       characters, so a cmd must be the same as the CmdPat string.  For example:

              skill /usr/local/bin/skill   user1 user2 user3

       Here, any user in the  list  {user1,  user2,  user3}  may  type  super  skill  to  execute
       /usr/local/bin/skill.

       Advanced Use: Command Patterns with Wildcards.

       More generally, a CmdPat can be either an ed-style pattern (``regex'' — the BSD 4.x syntax
       used in the re_comp()/re_exec() routines), POSIX regular expressions, or  a  Bourne-shell-
       style  pattern.   You  can  set  the  pattern  style using the global option patterns (see
       below).  The default is ``regex'' for historical reasons;  however,  shell-style  patterns
       are  easier to use without errors, and most sites should use shell-style patterns.  In all
       cases the patterns are extended to  support  csh-style  brace  expansion.   For  instance,
       a{x,y,z}b stands for the set of patterns axb ayb azb.  Don't put any whitespace inside the
       braces!

       For convenience, there is always an implied set of braces around an entire pattern.   This
       means  that  any comma-separated list a,b,c is interpreted as {a,b,c}, and is very helpful
       so that you don't have to worry about getting braces just right  when  you  build  complex
       lists of out of (say) variables containing other lists of users.

       All pattern matching is ``anchored'': patterns are forced to match the entire cmd string.

       If  the  CmdPat is matched and the other conditions are met (such as the user being in the
       PermittedUser list to execute this command), FullPath gives the name of the actual command
       that  will  be  executed with execve().  If FullPath contains an asterisk, the asterisk is
       first replaced by the user's cmd.

       If you put special pattern-matching characters into the CmdPat, but don't put an  asterisk
       into FullPath, you have simply given more ways a user can execute the same FullPath.  This
       isn't useful, and in fact isn't a good idea at all.  The power of using  patterns  in  the
       CmdPat  comes  when  FullPath includes an asterisk.  For instance, a SysV-based host might
       have an entry in the super.tab file that looks like:

              /usr/bin/{lp,lpstat,disable,enable,cancel} * \
                             :operators uid=0

       This would allow anybody in the "operators" group to have root access to the line  printer
       commands  (the  uid=0  tells  super to set the real uid to 0, not just the effective uid).
       For instance, if the user typed:

              super /usr/bin/disable some_printer

       then the FullPath (``*'') would be  replaced  by  /usr/bin/disable,  which  would  be  the
       command to exec.

       More conveniently, the super.tab file could have a line like:

              {lp,lpstat,disable,enable,cancel} /usr/bin/* \
                             :operators uid=0

       In this case, the user can type

              super disable some_printer

       The  asterisk-replacement  ability  also lets a user execute any of an entire directory of
       commands, using a super.tab entry like the following:

              op/* /usr/local/super/scripts/* :operators uid=0

       In this case, the user can type

              super op/xyz

       and super will execute /usr/local/super/scripts/op/xyz.

       The asterisk-replacement capability is useful but potentially dangerous,  because  it  may
       unintentionally  open  the  door  to  programs  you hadn't intended to give away.  It is a
       sensible precaution to restrict asterisk-replacement to entries where the valid-user  list
       includes trusted users only.

       If  you completely trust some users, but want logging of all actions executed as root, you
       could use:

              /*   *   ReallyReallyTrustedUsers
       or
              /.*   *   ReallyReallyTrustedUsers

       (depending on whether patterns=shell, patterns=regex, or patterns=posix).

       The trusted users can now execute any command.  Note that the pattern begins with a slash,
       to ensure that the cmd must be an absolute path — this helps avoid accidental execs of the
       wrong program.

       If you were really going to give everything away as shown above, you'd  probably  want  to
       exclude any public-area workstations, require the trusted users to periodically give their
       passwords, and set the real uid=root (instead of just the effective  uid),  so  the  entry
       might be modified to read something like:

              /*   *   TrustedUsers \
                       !{PatternsOfPublicWorkstations} \
                       password=y timeout=5 uid=0

The FullPath Field

       The  FullPath  field gives the name of the actual command that will be executed, and if it
       contains an asterisk, the asterisk is first  replaced  by  the  user's  cmd  string.   The
       FullPath  can  optionally  contain  a list of initial arguments that precede any arguments
       passed by the user.  For example,

              xyz  "/usr/local/bin/blah -o1 -o2 -xrm 'a b c'" ...

       specifies  that  when  a  valid  user  types  super  xyz,  the  command  to   execute   is
       /usr/local/bin/blah and its arguments will be
              argv[1]: -o1
              argv[2]: -o2
              argv[3]: -xrm
              argv[4]: a b c
       followed  by  any  arguments  that the user put on the super command line.  Note: asterisk
       replacement is only done on the filename part of the FullPath, not on the arguments.   You
       can  safely  include asterisks in the argument list.  For security, the user's cmd may not
       contain any whitespace or backslashes.

       The FullPath string  is  parsed  using  rules  similar  to  the  Bourne  shell  rules  for
       backslashes in quoted strings, namely:
              (a) backslash-newline is discarded;
              (b)  Otherwise,  if  outside  a  quoted  substring, \x → plain x, which will not be
              treated as a delimiter, quotemark, or comment character;
              (c) Otherwise, inside a quoted substring of FullPath:
                     \\\;
                     \qq, where q is the quote character that encloses the FullPath string;
                     other backslashes are preserved: \x\x.

       After  writing  a  command  with  such  backslash  escapes,  you  should   certainly   use
       ``super -d cmd''  to  check  that  your args are being parsed as expected before you offer
       this command to your users.

       The same cmd can be listed several times in the super.tab file, in which  case  the  first
       entry  that  allows the user to execute the command is chosen.  The EXAMPLES section shows
       how this can be useful.

Permitted Users

       Permitted users are those who may execute the specified Cmd's.  Entries for any number  of
       permitted  users  are given after the CmdPat and FullPath fields.  Local options — options
       that apply to this command only — may also appear anywhere after  the  FullPath.   Options
       are  distinguished  from  permitted  users  because  options  all have the form key=value,
       whereas permitted-user entries may not contain unescaped equal  signs.   Each  whitespace-
       separated word is a pattern in one of the formats

            •    [user~]user[:][@host]

            •    [user~]:group[@host]

            •    [user~]user[:group][@host]

       Note  that the user~ part is optional.  The user's login name must match the user pattern;
       the user must belong to a group whose name matches the group  pattern;  and  the  hostname
       must  match the host pattern.  If the user, group, or host part is not given, there are no
       corresponding restrictions.

       If the user is root, super acts as if all permitted-user  patterns  are  preceded  by  the
       pattern  user~root  —  that  is, root's rule is default-allow, instead of the default-deny
       rule that applies to all ordinary users.

       By default, the ``group'' field is first matched against named groups to  which  the  user
       belongs,  and  then  against  the user's decimal gid — this allows the user to be put in a
       group in the /etc/passwd file that isn't given a name in the  /etc/group  file.   (If  you
       want  to  change  the  rules  for  using decimal gid, see the use of MATCH_DECIMAL_UID and
       MATCH_DECIMAL_GID in super.c for details.)

       Since you can restrict users to particular hosts, a single super.tab file  can  be  shared
       among  many  different  machines.   If  the  host  part  is  of the form +xyz, then xyz is
       interpreted as a netgroup name and any host in netgroup xyz is matched.  In that case, xyz
       is taken literally, and not interpreted as a pattern to be matched.  Note: netgroup lookup
       is only implemented if the function innetgr() is available.

       If the host part doesn't match the hostname, it might be because the  pattern  and  actual
       hostnames  contain  two  different  (but  both  valid)  incomplete  versions of the fully-
       qualified domain name (FQDN).  By default, if the host part fails to match  the  hostname,
       the  FQDN  is  looked  up  and  all of the ways of naming the host are matched against the
       pattern.  For example,  if  the  FQDN  is  spacely.sprockets.com,  super  will  first  try
       spacely.sprockets.com,  then  spacely.sprockets,  and finally spacely.  This can be turned
       off; see option gethostbyname.  (You might want to turn it off  because  using  nameserver
       lookup  can  reduce  security  a bit — your host may query a nameserver on another host to
       obtain the FQDN, and (a) that nameserver or an intermediate host along the way could  have
       been subverted, or (b) another host could impersonate the nameserver.  In either case your
       computer could receive incorrect hostnames.)

       The patterns for valid users, groups, and hosts follow the same  rules  for  the  CmdPats,
       described  above:  they can be entered with either ed-style or Bourne-shell-style patterns
       (depending on the setting of the patterns global option);  csh-style  brace  expansion  is
       allowed; and all pattern matching is ``anchored'': patterns are forced to match the entire
       username, groupname, or hostname.

       To make it easy to exclude some users/groups/hosts, any of these patterns can  be  negated
       by  prefixing  the  pattern  with  `!'.  If a negated pattern is matched, the user may not
       execute the command, even if there was  a  previous  non-negated  pattern  that  the  user
       matched.   All  patterns  are  read  left-to-right, and the last matched pattern ``wins''.
       Thus if the user/group/host list is

              j.* !jo
              or
              user~j.* !user~jo

       then the first entry allows any username beginning with `j' to execute  the  command,  but
       the second entry disallows user `jo'.  If entered in the reverse order,

              !jo j.*

       then  the  second  entry,  `j.*',  allows all users beginning `j', and therefore the first
       entry has no effect.

Permitted Times

       The time condition restricts the days and times during which this command may be  matched.
       If  the  execution time isn't acceptable, then super ignores the control line, and ``falls
       through'' to inspect the next entry,  just  as  it  does  if  the  user/group/host  aren't
       acceptable.  A time condition looks like:
            time~pattern

       with patterns that look like:

              Pattern                       Example
              hh[:mm]-hh[:mm][/dayname]     13:30-17/monday
              {<,>,<=,>=}hh[:mm][/dayname]  <17/tues
              dayname                       Friday

       The  first  form  explicitly  specifies  an interval during which the command may be used.
       Times may not go past midnight; to specify the night between Monday and Tuesday, you  must
       do something like:
              time~{17:30-24:00/mon,0-8/tues}

       The  second  form for time patterns allows you to use logical operators.  The Monday-night
       example could equally have been rendered as:
              time~{>17:30/mon,<8/tues}
       (There is a tiny difference in the two examples above: in  the  first  example,  the  time
       range  includes 17:30 and 8:00; in the second example, the time range is 17:31-07:59.  Use
       time~{>=17:30/mon,<=8/tues} to make the interpretation identical to the first example.)

       If there are a series  of  time  patterns,  they  are  evaluated  left-to-right,  and  the
       rightmost  matching  pattern  is  used.  To permit execution between 17:30 Monday and 8:00
       Tuesday, but exclude 0:00 to 1:00 Tuesday, use:
              time~{>=17:30/mon,<=8/tues}  !time~{0-1/tues}

       By default, valid daynames are English, but  if  your  system  supports  the  setlocale(3)
       function,  the  global  option  lang=zzz  will set the valid names to those of locale zzz.
       Valid daynames are either (a) the full names of  the  chosen  language;  (b)  an  official
       abbreviated day name for that language; (c) a 3-or-more character abbreviation of the full
       weekday; or (d) *, meaning any day.  (You can check on super's valid daynames by executing
       super -d,  which  will  show  the  default names of the weekdays at or near the top of its
       debugging output, and show the new weekday names that take effect when the lang=zzz option
       is encountered.)

       Time  patterns have a special defaulting rule when the execution time is not in one of the
       intervals in the time list:
              • if all time patterns are negated, super permits execution at any time not in  one
              of the listed intervals;
              •  otherwise, there is at least one non-negated pattern, and super defaults to deny
              execution at times outside the specified acceptable intervals.
       The reason is that the natural interpretation of a series of negated conditions, such as
              !time~{0-8,17-24} !time~{sat,sun}
       is to infer that all other times are acceptable for execution.   On  the  other  hand,  if
       there are any ordinary, non-negated times, such as
              time~8-17/{mon,tues,wed,thu,fri}
       the natural interpretation is that any times not explicitly mentioned are not acceptable.

       Note  that  explicit  braces  are  important in the above list.  If they were missing, the
       implied braces around the entire pattern would render this equivalent to
              time~8-17/mon time~tues time~wed time~thu time~fri
       That is, the permitted times are 8-17h on Monday, and any time on Tuesday through Friday.

Global Conditions

       Global options and conditions affect the overall super processing.  To set them, you  must
       use a line like

              :global             Global Options And Patterns
       or
              :global_options     Global Options And Patterns

       For backwards compatibility, you can alternatively use

              /         /         GlobalOptionsAndPatterns

       but this use is discouraged.

       These  so-called  ``global'' options and conditions actually take effect immediately after
       the line on which they appear, and are valid until the end of the input or until there  is
       a  countermanding global option or pattern.  To have a global option or pattern affect the
       entire file, you must place it as the first non-comment line of the super.tab file.

       If there are any PermittedUser or PermittedTime conditions on the  global  settings  line,
       they  are  applied  to  each following command in the super.tab file.  The conditions look
       like

              :global   cond cond ...  <> cond cond ...

       PermittedUser and PermittedTime conditions to the left of ``<>'' are processed before  the
       local  (per-command) conditions; conditions to the right of ``<>'' are processed after the
       per-command conditions.  If ``<>'' is missing, all  conditions  are  processed  after  the
       local conditions.  Example 1:

              :global   jan <> !@+badhosts

       says that user jan can usually execute any command, but under no circumstances will a user
       on any host in netgroup badhosts be allowed to execute any command.  (User jan will not be
       allowed  to  execute  a command if the per-command conditions disallow it, or if jan is on
       one of the badhosts computers).

       Example 2:
              :global   !root <>

       changes root's default setting from default-allow  to  default-deny,  just  like  ordinary
       users.   Root will only be given execute permission for entries that explicitly allow root
       on the per-entry line.

       Global PermittedUser (PermittedTime) conditions take effect on the line on which they  are
       defined, and are good until another set of global PermittedUser (PermittedTime) conditions
       is entered on another :global_option line.  That is, a new global condition line  replaces
       any previous global conditions.

       One  sensible approach to using global conditions is to put conditions that allow users to
       execute commands before the per-command conditions are  processed,  and  to  put  negating
       patterns  (for  users/groups/hosts that are never to be allowed to execute anything) after
       the per-command conditions.

       (Global options are discussed below, together with local options).

Conditionally-included Control Lines

       Control lines can be conditionally included by using the :if control line.   This  can  be
       helpful  when  using  a  single  super.tab file for hosts with different architectures, or
       hosts in different NIS domains, etc.  The syntax is:

              :if  left   op   right     moreText

       The expression left op right is evaluated, and  if  true,  moreText  is  evaluated  as  an
       ordinary control line.  The valid comparison operators are:

            •    ==   string equality
            •    !=   string inequality
            •    ~    glob match string left against pattern right
            •    !~   negated glob-match.
       For  example,  you  could  include  a file of commands only valid on Sun4-type machines as
       follows:

              :if $UNAME_MACHINE ~ sun* \
                       :include  /Path/To/Sun4/File
       (UNAME_MACHINE is a variable automatically defined by super; see the following section  on
       variables.)

       If you wanted to exclude Sun4c-type machines from using the file, you could modify this to
       be:

              :if $UNAME_MACHINE ~ sun* \
                  :if $UNAME_MACHINE != sun4c \
                       :include  /Path/To/Sun4/File

       There are no boolean operators provided, but note that there is an  implicit  boolean  and
       available by concatenating :if commands, as shown in the second example above.

Variables

       Super  offers  variables  to  make  it easier to handle entries that are duplicated or are
       constructed out of other entries.  Variables are defined by typing

              :define VariableName VariableDefinition

       or they may be imported from the environment by using

              :getenv [EnvVarName...]

       If you use the :getenv command, then the values of any imported environment variables  may
       only  contain  the  following ``safe'' characters: -/:+._a-zA-Z0-9.  If ``bad'' characters
       are found in a value, the entire value is replaced with an empty string.  Note that  these
       imported  variables  do  not  enter  the  environment of any executed command; they simply
       become part of the super.tab variable set.

       The VariableName should be made up only of letters, digits, and/or underscore.   (You  can
       actually  use  any characters you wish, but super doesn't promise to work correctly if you
       use characters outside the standard set.)

       The VariableDefinition begins at the first non-whitespace character after the VariableName
       and  continues  up  to  but  not  including  the  final newline.  Comments embedded on the
       variable definition line(s) are deleted before  the  variable  definition  is  stored.   A
       variable  definition may be continued across multiple lines by preceding each newline with
       a backslash, and indenting the continuation line with whitespace.   Just  as  for  regular
       control  lines,  the  backslash-newline-whitespace sequence is treated as whitespace if it
       follows a letter, digit, or underscore; otherwise, it is eliminated.  For example,

              :define  Users   user1,\
                               user2,\
                               user3
       and
              :define Users   user1,user2,user3

       are equivalent definitions.

       Unlike Makefiles, the variable definitions are not scanned first and  then  the  file  re-
       scanned.   Instead,  variables  take  effect  at the point they are defined, and remain in
       effect until they are re-defined or end of file — thus variables definitions must  precede
       their first use in the file.

       Variables  may  contain  other variables (which must have already been defined).  Variable
       substitution is done when a line is first read.  A line is never re-scanned after variable
       substitution.

       Variables are used in a file by typing

              $VariableName

       or

              $(VariableName)

       The  special variable $$ is replaced by a single ``$''.  Any other name $X (where X is not
       a letter, digit, or underscore) is an error.

       Because a line is never re-scanned after variable substitution, the following sequence:

              :define A $$
              :define B A
              :define C $B $$B
              $C

       defines C to be simply ``A $B''.

       Variables can be helpful in grouping users or hosts  together.   For  example,  you  might
       restrict access to a command so that it can't be run from a public-access workstation:
              :define Room103_WS hosta,hostb,hostc,hostd
              :define Room105_WS hoste,hostf,hostg,hosth
              :define Room106_WS +nonprivate
              :define PublicWorkstations $Room103_WS,$Room105_WS,$Room106_WS
              SomeCmd FullPathHere !@$(PublicWorkstations)

       In the above example, we have taken advantage of the implied braces that are always placed
       around any pattern, so that the comma-separated list  of  workstations  is  brace-expanded
       into !@hosta !@hostb ... !@hoste !@hostf ... !@+nonprivate.

       Some variables are automatically defined by super.

       After  super  determines  whether it is processing a per-user .supertab (see super(1)), it
       defines IS_USERTAB to be ``yes'' if super is processing a  per-user  .supertab  file,  and
       ``no''  otherwise.   The  allows  the super.init to act differently depending on how it is
       being invoked.

       When the top-level super.tab file is opened, SUPER_OWNER is set to the login name  of  the
       owner,  and  SUPER_HOME  is set to the home directory of the owner.  This can be useful in
       per-user .supertab  files,  especially  when  they  include  files  shared  among  several
       accounts.  For example, each person's .supertab file could be simply

              :include /opt/proj/common.supertab owner=cristy

       Then, the /opt/proj/common.supertab file can use entries like the following:

              :global logfile=$SUPER_HOME/.superlog
              * /project/tools/$SUPER_OWNER/* :toolgroup

       Because  the  SUPER_HOME  and SUPER_OWNER variables apply to the top-level per-user files,
       they always refer to per-user locations.

       Super defines the built-in variable CALLER to be the the login  name  of  the  of  account
       invoking super, and CALLER_HOME is the home directory of $CALLER.  Sample use:
              sam  /usr/sbin/sam  group~operator  uid=0 \
                                  env=DISPLAY \
                                  setenv=XAUTHORITY=$CALLER_HOME/.Xauthority
       Here, the operator group can execute sam as root, and the GUI will display at the caller's
       display (due to the use of env=DISPLAY).  Since the XAUTHORITY environment variable is set
       to  the caller's .Xauthority file, this will give the caller access to the same display(s)
       to which s/he already has access.

       The following variables are  defined  when  super  starts  up.   They  can  be  useful  in
       conditionally-included lines (:if lines).  If your host doesn't supply these functions, or
       doesn't support some of the values that super tries to fetch, the  corresponding  variable
       will  be  initialized  to an empty string.  (Use super -b to print the names and values of
       all builtin variables.  This makes it simple to see what variable values to check  in  :if
       lines.)

       From the gethostname() or sysinfo() function:
            • HOSTNAME            Hostname, possibly canonicalized.
            • HOST                Hostname, short (unqualified).

       From the getdomainname() function:
            • NIS_DOMAIN          domain set for NIS purposes.

       From the sysinfo() function:
            • SI_SYSNAME          Name of operating system.
            • SI_HOSTNAME         Name of node.
            • SI_RELEASE          Release of operating system.
            • SI_VERSION          Version field of utsname.
            • SI_MACHINE          Kind of machine.
            • SI_ARCHITECTURE     Instruction set arch.
            • SI_HW_SERIAL        Hardware serial number.
            • SI_HW_PROVIDER      Hardware manufacturer.
            • SI_SRPC_DOMAIN      Secure RPC domain.
            •

       From the uname() function:
            • UNAME_SYSNAME       Operating system name.
            • UNAME_NODENAME      The nodename.
            • UNAME_RELEASE       Operating system release.
            • UNAME_VERSION       Operating system version.
            • UNAME_MACHINE       Machine hardware name (class).

Options

       The configuration file can specify a wide variety of options, such as requiring the user's
       password before executing some commands, or  restricting  the  command-line  arguments  to
       match certain patterns.

       Options  are  handled  very  differently  from conditions (conditions include user, group,
       host, and time).  If a control line's conditions aren't met, super falls through and tries
       the  next  control line in the file.  After finding an acceptable control line, super will
       execute the command if the options are satisfied; otherwise, it stops and  doesn't  search
       the super.tab file any further.

       Options  can  be  divided  into  (a) local options, which are defined on a regular control
       line, and apply only to that control line; and (b) global options, which are defined on  a
       :global  or  :global_options  line,  take effect immediately after the line, and are valid
       until the end of the input or until there is a countermanding global option or pattern.

       All options are orthogonal to each other.  It doesn't matter in what order they appear  on
       a control line.

       Some  options can be given as either local or global options.  If both are used, the local
       setting overrides the global one.

       Two special names can be used with any of the options that  take  user  or  group  ids  as
       arguments:   owner=xxx,   uid=xxx,   euid=xxx,  gid=xxx,  egid=xxx,  u+g=xxx,  groups=xxx,
       addgroups=xxx.  These names are <owner>, meaning the owner of the file to be executed  (or
       the  owner's  group,  whichever  is appropriate in the context); and <caller>, meaning the
       owner or group of the user calling super.  The angle brackets are literally  part  of  the
       name.   These  have  the  same  values as the built-in variables CALLER and OWNER (see the
       Variables section, above).  For example, the options
              gid=Foo uid=<caller>
       would change the group to Foo, but leave the uid unchanged.

       The recognized options are:

       Group 1.  Options Affecting How Superfiles Are Read and Processed.

       patterns=xxx
              (Global) Specifies the pattern-matching  type  for  conditions  and  options.   The
              string xxx must be one of:

              posix — patterns are POSIX regular expressions.  You can use ``posix/extended'' for
                     extended regular expressions; ``posix/icase'' for  case-insensitive  regular
                     expressions;  or  ``posix/extended/icase''  for  both.   See  your  regular-
                     expression man pages for details.

              regex — patterns are ed-style regular expressions, using the rules embodied in  the
                     BSD 4.x  routines  re_comp()/re_exec(), with the addition of csh-style brace
                     expansion.  This is the default for  historical  reasons,  but  most  people
                     prefer  to use shell-style patterns here, and it is recommended that you put
                     patterns=shell (see below) in your global options list.

              shell — patterns are approximately Bourne-shell style, with the  addition  of  csh-
                     style  brace  expansion and the special [[chars]] pattern.  The patterns are
                     formed from:

                     \x   force x to be a plain character;

                     ?    matches any single character;

                     *    matches any sequence of 0 or more chars;

                     [chars]   matches any single character in the set;

                     [^chars]  matches any single char NOT in the set;

                     [[chars]] When the pattern begins with [[, and ends with ]], then  each  and
                            every  character in the string must match the ordinary square-bracket
                            pattern [chars] (or [^chars]).

                     ^pat inverts the sense of the match — the string must NOT match the pattern.

       lang=zzz
              (Global) This option sets the language used  for  weekdays  (in  time  conditions).
              Here,  zzz  may  be  any locale available on your host.  For example, lang=de would
              typically cause super to use German names.  The default  is  the  C  locale,  hence
              English names.

       relative_path=y|n
              (Global)  If y, FullPathNames can be relative instead of absolute.  By default this
              is disallowed, because it is almost always a very foolish (unsafe) thing to do.

       group_slash=y|n
              (Global) If y, group names can contain a slash.  By default this is disallowed,  so
              that super can catch certain typos in the super.tab file.  (Namely, super can catch
              errors in which an entry is of the form Cmd:File instead of the required Cmd::File.
              The trouble is that Cmd:File looks syntactically like user:group, and can therefore
              be mistaken for a valid part of a control line.  But the filename  will  contain  a
              slash  — unless you have unwisely enabled the relative_path option — so disallowing
              slashes allows super to flag the line as syntactically invalid.)

       gethostbyname=y|n
              (Global) Enables or disables the use of gethostbyname() to find the fully-qualified
              domain name (see the discussion in the Permitted Users section, which describes the
              security issues associated with enabling this option.)  Default: enabled  (if  your
              host supports gethostbyname()).

       Group 2.  Logging Options.

       logfile=fname
              (Global)  Enables  logging  to  a local file.  Each invocation of super (aside from
              ones for help) generates an entry in file fname.

       loguid=xxx
              (Global) If logging is enabled with logfile=fname, the logfile will be  opened  for
              writing  using  uid=xxx  (can  be  either  a username or numeric uid).  This option
              allows you to have the file created/opened under another uid that does have  cross-
              host  access,  such  as  the  uid  of  a system manager.  (See timestampuid=xxx for
              additional comments).  Default: loguid=0.

       mail="mail-command"
              (Local|Global) Notices of super failures are  piped  to  the  shell  command  mail-
              command.   This  is  independent  of the setting of the logfile and syslog options.
              For instance, mail="mail -s Super joeblow" will cause error messages to  be  mailed
              to user joeblow (on some systems you may need to substitute mailx for mail).  Note:
              the mail-command is executed by passing it as an argument  to  popen(3).   This  is
              safe to execute because of the clean environment assured by super.

       mailany="mail-command"
              (Local|Global)  This  is  identical  to  the mail option, except that mailany sends
              notification of successful invocations as well as errors.

       rlog_host=hostname
              (Global) Tells super which host's syslog daemon is to  receive  log  messages  when
              option  syslog=y  is  enabled.   The  option  has no effect if used after the first
              message is logged: once the logger has been opened, it  is  not  re-opened  if  the
              rlog_host  is changed.  Default: the local host.  Note: One could instead configure
              the syslog.conf file to forward the messages to a central machine.

       syslog=y|n
              (Global) Logging information is passed  to  the  logs  maintained  by  the  syslogd
              daemon.   This  is independent of the setting of the logfile option (above).  Error
              messages are by default logged at priority LOG_ERR and successful attempts  to  run
              programs   are   logged  at  priority  LOG_INFO.   (See  options  syslog_error  and
              syslog_success to change these levels.)

       syslog_error=xxx
              (Global) If syslog is enabled (see the syslog option), then by default  super  logs
              error  messages using syslog(3) code LOG_ERR.  This option changes the code to xxx,
              where xxx is any of the usual syslog(3) priority and/or  facility  codes,  such  as
              LOG_WARNING   or  LOG_LOCAL7|LOG_ERR.   The  LOG_xxx  words  can  be  separated  by
              whitespace, dot, and/or ``|'', but of course you must use quotes if  whitespace  is
              included.   The leading "LOG_" is optional, and the value is case-insensitive.  For
              example, LOG_LOCAL7|LOG_ERR can alternatively  be  written  as  local7.err.   Super
              doesn't  know  what  are sensible codes — it's up to the super.tab writer to choose
              meaningful values.  For instance, if you put
                   syslog_error="LOG_INFO | LOG_ERR" (bad!)
              then you will get both those values or'd together and passed to syslog().

       syslog_success=xxx
              (Global) This  option  is  just  like  syslog_error,  except  that  it  applies  to
              successful-execution messages instead of error messages.  Default: LOG_INFO .

       Group 3.  Extra Help Information for Users.

       info=xxx
              (Local) The string xxx is printed when giving help to users.  It should be set to a
              helpful one-line description of the command.

       Group 4.  Password and Other Restrictions Before Approval.

       maxlen=[mmm,]nnn
              (Local|Global) Each argument must be no more than mmm  characters  long  (including
              the  terminating  null),  and  the  sum length of all arguments must not exceed nnn
              characters.  A negative value means that no limit is applied.  The defaults for mmm
              and  nnn  are set by the compile-time manifest constants MAXLEN1ARG and MAXLENARGS,
              which are usually 1000 and 10,000 characters, respectively.

       nargs=[mmm-]nnn
              (Local|Global) The user is required to enter mmm - nnn arguments  to  the  command.
              If  just  nnn is given, the user must enter exactly nnn arguments.  These arguments
              are in addition to any arguments entered in the command part of the super.tab file.
              The default is to allow the user to enter any number of arguments.

       arg[mmm-]nnn=sss
              (Local|Global)  This  means  that  the  nnn'th  or  mmm-nnn'th arguments must match
              pattern sss.  (Arguments are numbered from 1.)  The pattern  must  be  enclosed  in
              quotes  if  it  contains  whitespace.   Note that this option does not require that
              there be mmm-nnn arguments; it only says what those arguments must  look  like,  if
              entered.  You can use this option several times on one line, with different mmm-nnn
              values each time, to apply different patterns to different arguments.  If more than
              one pattern applies to a given argument, all of those patterns must be matched.  An
              empty pattern ("") is special: it  has  the  effect  of  unsetting  (removing)  any
              previous  patterns  for  the matching [mmm-]nnn.  This can be useful if you want to
              change  :global  settings,  instead  of  adding  to  them.   If  there  are   local
              arg[mmm-]nnn  option(s),  they  completely  replace all global arg[mmm-]nnn values,
              even if the local mmm-nnn values do not overlap with the global values.

       owner=xxx
              (Local|Global)  This  option  specifies  that   the   FullPath   (after   asterisk-
              substitution) must be owned by user (or uid) xxx, or else it won't be executed.

       auth=y|n
              (Local|Global)  If  y,  user  authentication  is  required  before  the  command is
              executed.  The default authentication method is Unix password authentication.   See
              also  the  options  authprompt,  authtype, authuser, timeout, and renewtime, and be
              sure to read the warning under timestampbyhost.

       authprompt=message
              (Local|Global) Specifies the prompt used when authenticating the user (usually  the
              default  prompt  is  fine).   Variable  substitution  is  done on the prompt before
              printing.

       authtype=type
              (Local|Global) Specifies the type of authentication used when auth=y.  The type can
              be  password or pam (if PAM is supported on your system).  The default is password.
              If PAM authentication is used, super uses the service name ``super''  when  looking
              for authentication in your system PAM configuration files.

       authuser=username
              (Local|Global)  Specifies  the  user  whose authentication is required when auth=y.
              The default is the password (or other authentication)  for  the  user  who  invoked
              super.

       password=y|n
              (Local|Global)  This  is  a deprecated option; it has been replaced by the auth and
              authtype options.  Password=y is  equivalent  to  auth=y  authtype=password  ;  and
              Password=n is equivalent to auth=n.

       renewtime=y|n
              (Global) If y, the user's timestamp file is updated to the current time whenever an
              authentication-requiring command is executed.   The  result  is  that  a  user  who
              frequently executes authentication-requiring commands won't need to re-authenticate
              until more than timeout minutes elapse since the last such command.  Otherwise, the
              user will need to re-authenticate timeout minutes after last entering the password.
              The default is n.

       timeout=m
              (Local|Global) User authentication is good for m minutes; that is, the command  may
              be   executed   without   re-authenticating   for  m  minutes  after  the  previous
              authentication (for any command).  After m minutes,  user  authentication  will  be
              required again before the command can be executed.  If timeout is zero or negative,
              authentication is required every time the command is used.  The timestamp for  user
              usr  is  recorded  in the file TIMESTAMP_DIR directory (see timestampbyhost and the
              FILES section, below).

       timestampbyhost=y|n
              (Global) If y (default), the timestamp files are given names  that  are  unique  on
              each  host.   For  instance,  jouser@somehost  will be given a timestamp file named
              TIMESTAMP_DIR/somehost/jouser, where TIMESTAMP_DIR is defined in the FILES section.
              If  timestmapbyhost=n,  the timestamp files are given names that are unique to each
              user, but not unique per host.  For instance, jouser on any host will  be  given  a
              timestamp file named TIMESTAMP_DIR/jouser.
              WARNING:  The  hostname  used  is  that  from gethostname().  Note that this is not
              necessarily unique across internet domains, since it is  frequently  not  a  fully-
              qualified  domain  name.  Therefore you should not share timestamp directories with
              hosts outside the local domain.  (Generally such connections don't exist,  but  one
              could crossmount the timestamp directory disk...)

       timestampuid=xxx
              If  a  password  is  required,  the time at which it was entered is recorded as the
              mtime of a timestamp file.  The timestamp file is normally created with owner=root;
              however,  this  option  causes  it to be created/modified using uid=xxx (xxx can be
              either a username or numeric uid).  This option is useful when a network  of  hosts
              are  sharing a cross-mounted timestamp directory.  Note that networks are typically
              configured to not allow root on one host to have root access to  files  on  another
              host, which will forbid root on other hosts from creating the timestamp file unless
              it's world-writable.  This option allows you to have the file created/opened  under
              another  uid that does have cross-host access, such as the uid of a system manager.
              Default: timestampuid=0.

       checkvar=name[,...]
              (Local) Each name in the comma-separated list is a  super.tab  variable  which  the
              user  must  enter  at  a  prompt  from  super.  For example, you might have a super
              shutdown command which halts the computer.  If you execute this on the  wrong  host
              there  may  be some very annoyed users!  So, you can include checkvar=HOST, and the
              user will have to type the correct hostname in response to a prompt from super.

       Group 5.  Modifications to Environment Before Executing Command.

       uid=xxx
              (Local) Sets the real uid to xxx just before executing the command.  If option euid
              isn't  used,  also  sets the effective uid to xxx.  The uid xxx is first tried as a
              login name and then as a number.  If the options uid=xxx and  u+g=yyy  (see  below)
              are used together, then the u+g option only sets the group id, and not the user id.

       euid=xxx
              (Local)  Sets  the effective uid to xxx just before executing the command.  The uid
              xxx is first tried as a login name and then as a number.

       gid=yyy
              (Local) Sets the real gid to yyy just before executing the command.  If option egid
              isn't  used,  also  sets the effective gid to yyy.  The gid yyy is first tried as a
              group name and then as a number.

       egid=yyy
              (Local) Sets the effective gid to yyy just before executing the command.   The  gid
              yyy is first tried as a group name and then as a number.

       u+g=zzz
              (Local)  Sets  the  real  uid  to  zzz,  the  real  gid to zzz's login gid, and the
              supplementary groups list to zzz's supplementary groups just before  executing  the
              command.  If the euid and/or egid option aren't given, the effective uid and/or gid
              are also set.  The options u+g and gid=yyy conflict with each other, and may not be
              used together.

       groups=name[,...]
              (Local|Global)  By  default, the user's supplementary groups list is deleted before
              executing a command (unless the option u+g is used).  This option instead sets  the
              group list to name[,...]

       addgroups=name[,...]
              (Local|Global) This option adds the listed groups to the supplementary groups list.
              Since the default is to provide an empty supplementary  groups  list,  this  option
              usually  has  the  same effect as the plain groups option.  However, if the options
              u+g=foo addgroups=a,b,c are used, then the supplementary groups list is composed of
              user foo's supplementary groups plus a, b, and c.

       argv0=name
              (Local)  Execute  the  command  will  execute with its first argument (that is, the
              argument conventionally  denoted  as  argv[0]),  set  to  name.   As  a  convenient
              shorthand,  the  value  <path>  (the angle brackets are literally part of the name)
              means to use the FullPath specified in the super.tab file.  By default, argv[0]  is
              set  to  Cmd,  the name of the super command invoked by the user, regardless of the
              actual path being invoked.  However, some programs will  not  run  properly  unless
              argv[0]  has  a particular value.  For example, suppose you want to permit users to
              safely mount zip disks, and you use something like:
                   zipmount "/etc/mount -o nosuid /dev/xz10  /zip"
              This command will fail if /etc/mount requires that it be invoked with  argv[0]  set
              to  [.../]mount,  because  super  will use the name zipmount.  However, you can put
              argv0=<path> into your super.tab  file,  and  then  the  mount  command  will  work
              properly.

       env=name[,...]
              (Global|Local)  Each  name  in  the comma-separated list is an environment variable
              which should not be deleted before  executing  the  Cmd;  these  variables  are  in
              addition to the normal variables created or passed by super (TERM, IFS, PATH, USER,
              LOGNAME, HOME, ORIG_USER, ORIG_LOGNAME, ORIG_HOME, LINES, COLUMNS,  SUPERCMD).   Be
              careful  here;  environment  variables  can  sometimes be abused to create security
              holes.  If you use the option more than once,  the  later  instance  overrides  the
              earlier  one,  instead  of  adding  to  it.   Similarly, using it as a local option
              completely overrides any global setting.

       maxenvlen=nnn
              (Global|Local) Specifies the maximum length of an environment  variable  definition
              (including  name,  equal sign, value, and trailing null character).  The default is
              given by the compile-time manifest constant MAXENVLEN, usually 1000 characters.   A
              negative value means no limit.

       cd=dir
              (Local|Global)  Just  before  executing  the  command,  super  changes  the working
              directory to dir.

       setenv=var=xxx
              (Local|Global) The environment variable var is defined to have the value  xxx,  and
              is  passed  on  when  executing  the Cmd.  You can add several environment variable
              definitions by using the option more than once.

       fd=n[,...]
              (Local) Each file descriptor n in the comma-separated list  should  not  be  closed
              before  executing  the  Cmd.   These  descriptors  are  added  to  the usual set of
              descriptors kept open, namely 0, 1, 2.

       nice=n
              (Local|Global) changes the ``nice'' value of the executed command by  an  amount  n
              from  the  default  level.   (Positive  increments  reduce  the command's priority;
              negative increments increase it.)

       umask=nnn
              (Local|Global) sets the umask of any executed command to n.  A leading 0x or 0X  in
              nnn  means  a hexadecimal value; otherwise, a leading 0 means octal; otherwise it's
              decimal.

       Group 6.  Other Options

       print=message
              (Local) If the rest of the line is matched, then super prints the specified message
              just before executing the command.

       die=message
              (Local)  If  the rest of the line is matched, then super does variable-substitution
              on the specified message message, prints it, and exits.  This lets you conveniently
              set  up  some  ``stop''  conditions,  and  use the die option to prevent super from
              looking  at  any  line  past  the  stop  conditions.   Otherwise,  you'd  have   to
              individually attach the stop conditions to every control line.

Include Files

       A super.tab file can include other files by means of an entry like
              :include filename [ owner=xxx ] [ group=yyy  ]
       or
              :optinclude file [ owner=xxx ] [ group=yyy  ]
       If the file isn't an absolute path, it is taken to be relative to the directory containing
       the super.tab file.  Include files may be nested up to the system limit on the  number  of
       simultaneously-open file descriptors.

       The  owner=xxx  option  specifies  that  the file must be owned by user xxx; the group=yyy
       options specifies that the file must belong to group yyy.  If group=yyy is specified, then
       the file can be group-writable; by default, the file must be writable only by owner.  This
       can be useful for a collection of accounts that are operated together as part of a  single
       project  —  the  several  of  accounts  can  share  .supertab  files by :include-ing files
       belonging to the trusted user xxx and/or group yyy.  Notes:

              1.  The regular root-owned super.tab  file  can  also  use  the  owner=  or  group=
              constructs, but it's not a good idea.  Don't do it.

              2.   Beware  of  the  transitive nature of this trust: the file owned by xxx can in
              turn include a file owned by yet another user.  You might wind up trusting  a  user
              you didn't intend to trust!

       The  difference  between :include and :optinclude is that the former generates an error if
       the named file doesn't exist, whereas the latter (optional-include) silently ignores files
       that don't exist.

       WARNING:  You should use :optinclude with great caution, and be sure not to depend on that
       file being present.  It is easy to imagine a scenario in which an administrator carelessly
       changes  an  entry  so  that  the wrong permission is granted if an :optinclude'd file was
       missing.

FILES

       /etc/super.tab
              The location of the super.tab file on your system.

       /etc/super.init
              The location of the super.init file on your system.

       /run/superstamps/username
              Default location of the file whose mtime is used as the timestamp for the last time
              the  user  entered his or her password for password-requiring commands.  Check your
              installation for the directory used on your system.

EXAMPLES

       Example 1.  The control line

                   doit /usr/local/bin/doit                \
                             me                            \
                             you@{h1,h32}                  \
                             ja.*:ok_j                     \
                             :goodguys

              allows /usr/local/bin/doit to be run setuid-root by
                   • user me on any host,
                   • user you on hosts h1 and h32;
                   • any users named ja.*  in group ok_j;
                   • and anybody in group goodguys.

       Example 2.  The pair of control lines

                   doit /usr/local/bin/doit                \
                             u+g=smith env=TZ,TAPE         \
                             password=y timeout=0          \
                             jo@PublicWorkstation

                   doit /usr/local/bin/doit                \
                             u+g=smith env=TZ,TAPE         \
                             jo

              allows user jo to run /usr/local/bin/doit  with  uid = smith,  gid = smith's  login
              gid,  and keeping the environment variables TZ and TAPE in addition to the standard
              set.  If user jo is at PublicWorkstation, the first  entry  will  match,  requiring
              jo's  password  every  time the command is used; otherwise, super will match at the
              second entry, and no password is needed to run the command.

       Example 3.  Here is an entry restricting CD-ROM mounting on different hosts:  tas  is  the
              only user who may mount CD's on elgar; anybody in group xyz may mount CD's on alpha
              or delta; and anybody on a host in the netgroup india may mount a CD on  the  india
              hosts.   However,  user jo may never run cdmount, regardless of his or her group or
              host (assuming that there is no overriding global pattern that permits  jo  to  use
              the command).  Note that shell-style patterns are used, not regex-style patterns.

                   cdmount /usr/local/bin/cdmount          \
                             tas@elgar                     \
                             :xyz@{alpha,delta}            \
                             *@+india                      \
                             !jo

SEE ALSO

       super(1).

                                              local                                  SUPER.TAB(5)