listen(8) [plan9 man page]

LISTEN(8)						      System Manager's Manual							 LISTEN(8)

NAME

       listen,	dkcpu, dkcpunote, dkdiscard, dkecho, dkexportfs, dkrexexec, dkticket, dkwhoami, dksmtp, dkdcon, dklogin, dkguard, il7, il9, il565,
       il566, il17005, il17006, il17007, il17009, tcp2, tcp7, tcp9, tcp21, tcp23, tcp80, tcp25, tcp513, tcp515, tcp564, tcp565, tcp566,  tcp17007,
       tcp6000 - listen for calls on a network device

SYNOPSIS

       aux/listen [-q] [-d srvdir] [-t trustsrvdir] [name]]

DESCRIPTION

       listen  announces  itself  to  a network as name (by default the contents of /env/sysname) and listens for inbound calls to local services.
       Net is the network device on which to listen, by default /net/dk.  The services available are executable 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 as executed as the user who started listen.  Option -q suppresses affirmative log information.

       Service names are made by concatenating the name of the network with the name of the service or port.  For example, an inbound call on  the
       TCP network for port 565 executes service tcp565, while a call on the Datakit network for service whoami executes service dkwhoami.

       The following services are available in /bin/service.

       dkcpu il17005
	      server for cpu(1) command.

       dkcpunote il17006
	      /proc/pid/notify forwarding for cpu(1).

       dkexportfs il17007 tcp17007
	      serve a piece of the name space using the Plan 9 file system protocol, with authentication (typically used by cpu(1)).

       tcp564 like 17007, without authentication (used by Unix systems to see Plan 9 files).

       dkrexexec il17009
	      remote execution.

       dkwhoami il565 tcp565
	      report the address of the incoming call.

       tcp21  FTP daemon

       tcp80  HTTP daemon; see httpd(8).

       tcp515 LP daemon; see lp(8).

       tcp6000
	      X-window callback

       dksmtp tcp25
	      mail delivery.

       dkdcon research Unix terminal connection.

       dklogin
	      generic terminal connection.

       tcp23  telnet terminal connection.

       tcp513 rlogin terminal connection.

       tcp2   hold the connection open; sleep for a long time

       dkecho il7 tcp7
	      echo any bytes received (bit mirror)

       dkdiscard il9 tcp9
	      consume any bytes received (bit bucket)

       The following services are available in /bin/service.auth.

       dkguard tcp566
	      check a SecureNet box.

       dkticket il566
	      authentication requests.

FILES

       /net/dk
	      by convention, Datakit device bind point

       /net/il
	      by convention, IL device bind point

       /net/tcp
	      by convention, TCP device bind point

       /env/sysname
	      default announced name

SOURCE

       The source to listen is in /sys/src/cmd/aux/listen.c.  The other commands are rc(1) scripts in /rc/bin/service.

SEE ALSO

       dkconfig(8), auth(6), dk(3), dial(2)

																	 LISTEN(8)

listen(1M)						  System Administration Commands						listen(1M)

NAME

       listen - network listener daemon

SYNOPSIS

       /usr/lib/saf/listen [-m devstem] net_spec

DESCRIPTION

       The  listen  process  ``listens''  to a network for service requests, accepts requests when they arrive, and invokes servers in response to
       those service requests. The network listener process may be used with any connection-oriented network (more precisely, with any connection-
       oriented transport provider) that conforms to the Transport Layer Interface (TLI) Specification.

       The  listener internally generates a pathname for the minor device for each connection; it is this pathname that is used in the utmpx entry
       for a service, if one is created. By default, this pathname is the concatenation of the prefix /dev/netspec with the decimal representation
       of  the	minor device number. In either case, the representation of the minor device number will be at least two digits (for example, 05 or
       27), or longer when it is necessary to accommodate minor device numbers larger than 99.

SERVER INVOCATION

       When a connection indication is received, the listener creates a new transport endpoint and accepts the connection on that endpoint. Before
       giving the file descriptor for this new connection to the server, any designated STREAMS modules are pushed and the configuration script is
       executed, (if one exists). This file descriptor is appropriate for use with either  TLI	(see  t_sync(3NSL)  )  or  the	sockets  interface
       library.

       By default, a new instance of the server is invoked for each connection. When the server is invoked, file descriptor 0 refers to the trans-
       port endpoint, and is open for reading and writing. File descriptors 1 and 2 are copies of file descriptor 0; no other file descriptors are
       open.  The  service  is	invoked with the user and group IDs of the user name under which the service was registered with the listener, and
       with the current directory set to the HOME directory of that user.

       Alternatively, a service may be registered so that the listener will pass connections to a standing server process  through  a  FIFO  or  a
       named  STREAM,  instead	of  invoking  the  server  anew for each connection.  In this case, the connection is passed in the form of a file
       descriptor that refers to the new transport endpoint. Before the file descriptor is sent to the server, the listener interprets any config-
       uration	script	registered for that service using doconfig(3NSL), although doconfig is invoked with both the NORUN and NOASSIGN flags. The
       server receives the file descriptor for the connection in a strrecvfd structure using an I_RECVFD  ioctl(2).

       For more details about the listener and its administration, see nlsadmin(1M).

OPTIONS

       -mdevstem       The listener will use devstem as the prefix for the pathname.

FILES

       /etc/saf/pmtag/*

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       nlsadmin(1M), pmadm(1M), sac(1M), sacadm(1M), ioctl(2), doconfig(3NSL), nlsgetcall(3NSL), nlsprovider(3NSL),  t_sync(3NSL),  attributes(5),
       streamio(7I)

       System Administration Guide: Basic Administration

NOTES

       When  passing a connection to a standing server, the user and group IDs contained in the strrecvfd structure will be those for the listener
       (that is, they will both be 0); the user name under which the service was registered with the listener is not reflected in these IDs.

       When operating multiple instances of the listener on a single transport provider, there is a potential race condition  in  the  binding	of
       addresses during initialization of the listeners, if any of their services have dynamically assigned addresses. This condition would appear
       as an inability of the listener to bind a static-address service to its otherwise valid address, and would result  from	a  dynamic-address
       service having been bound to that address by a different instance of the listener.

SunOS 5.10							    3 Apr 1997								listen(1M)