LISTEN(8)                                               LISTEN(8)

          listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp23, tcp25,
          tcp110, tcp113, tcp143, tcp445, tcp513, tcp515, tcp564,
          tcp565, tcp566, tcp567, tcp993, tcp995, tcp1723, tcp17019,
          tcp17020 - listen for calls on a network device

          aux/listen [-iq] [-d srvdir] [-t trustsrvdir] [-n namespace]
          [-p maxprocs] [-o copt] [-O sopt] [-a addr] [proto]

          aux/listen1 [ -1tv ] [-n namespace] [-p maxprocs] [-o copt]
          [-O sopt] addr cmd [ args... ]

          Listen listens on a network for inbound calls to local ser-
          vices.  Proto is the network protocol on which to listen, by
          default tcp.  Incoming calls to any address * are accepted
          unless addr is specified with the -a option. The services
          available are executable, non-empty files in srvdir or
          trustsrvdir. If neither srvdir nor trustsrvdir is given,
          listen looks for executable files in /bin/service.  Services
          found in srvdir are executed as user none; services found in
          trustsrvdir are executed as the user who started listen.
          When changing user to none, a new namespace is created, usu-
          ally by executing /lib/namespace, but -n selects an alter-
          nate namespace. The -p option limits the number of processes
          that listen spawns to service the connections. If the
          maxprocs limit is reached, listen will log the event and
          delay servicing until the number of connection processes
          drops below the limit again. A maxprocs smaller or equal
          zero means no limit (default).  The -o and -O options cause
          protocol-specific control messages to be written to the con-
          trol file of the listening server connection -O or the
          incoming client connection -o.  They can be specified multi-
          ple times. See ip(3) for details.  Option -q suppresses
          affirmative log information.  Option -i suppresses the peri-
          odic scan of the service directories for changes.

          Service names are made by concatenating the name of the net-
          work with the name of the service or port.  For example, an
          inbound call on the TCP network for port 565 executes ser-
          vice tcp565.

          Services may have individual namespace(6) files specified
          within srvdir. If provided, the namespace is used as the
          parent for each connection to the corresponding service.
          Namespace files are found by appending a .namespace suffix
          to the service name.

          At least the following services are available in

     LISTEN(8)                                               LISTEN(8)


          tcp564    serve a piece of the name space using the Plan 9
                    file system protocol, with authentication via
                    Tauth (in attach(5)), no encryption, and multiplex
                    multiple users on a single connection (used by
                    srv(4), and also by Unix systems to see Plan 9
          tcp17019  server for rcpu(1), replaces rx, import and cpu
                    using TLS for encryption.
          tcp17020  TLS encrypted 9P fileserver (t9fs) for srvtls (see
          tcp7      echo any bytes received (bit mirror)
          tcp9      consume any bytes received (bit bucket)
          tcp19     chargen service.
          tcp21     FTP daemon
          tcp23     telnet terminal connection.
          tcp25     mail delivery.
          tcp110    POP3 port.
          tcp113    Ident port (always reports none).
          tcp143    IMAP4rev1 port.
          tcp445    CIFS/SMB file sharing.
          tcp513    rlogin terminal connection.
          tcp515    LP daemon; see lp(8).
          tcp565    report the address of the incoming call.
          tcp993    Secure IMAP4rev1 port.
          tcp995    Secure POP3 port.
          tcp1723   PPTP (point-to-point tunnelling protocol) service.

          At least the following services are available in
          /bin/service.auth, the usual trustsrvdir.

          tcp566    validate a SecureNet box.
          tcp567    Plan 9 authentication-ticket service.

          Listen1 is a lightweight listener intended for personal use,
          modeled from Inferno's listen(1).  It announces on address,
          running cmd args... for each incoming connection; the net-
          work directory is passed in the environment as $net.  Option
          -t causes listen1 to run as the invoking user; the default
          is to become none before listening.  Option -1 arms a one-
          shot listener; it terminates listen1 upon receiving a single
          call.  Option -v causes verbose logging on standard output.
          See /rc/bin/tlssrvtunnel for an example.

          /net/tcp      by convention, TCP device bind point


     LISTEN(8)                                               LISTEN(8)

          authsrv(6), dial(2), ip(3)

          Srvdir, trustsrvdir and namespace must all be absolute path