###########################################################################
#                                                                         #
#               Copyright (C) 1995, Silicon Graphics, Inc.                #
#                                                                         #
#   These coded instructions, statements, and computer programs  contain  #
#   unpublished  proprietary  information of Silicon Graphics, Inc., and  #
#   are protected by Federal copyright law.  They  may  not be disclosed  #
#   to  third  parties  or copied or duplicated in any form, in whole or  #
#   in part, without the prior written consent of Silicon Graphics, Inc.  #
#                                                                         #
###########################################################################

#%COMMENT_BEGIN
# Filename:	hostUtil.tlib
# Version:	$Revision: 1.4 $
# Synopsis:	General functions for getting host related information.
# Packages:	HostUtil-Base
#
#
#%COMMENT_END


#%COMMENT_BEGIN
# Package:	HostUtil-Base
# Functions:	hu:getHosts
#		hu:getRealHostName
#		hu:getIpAddress
#		hu:getHostPlusDom
#
# Function:	hu:getHosts
# Synopsis:	Returns a list of hosts retrieved from the given host.
# Arguments:	- host		The host from which to retrieve the list
#				of hosts.
#		- type		An optional argument that specifies where
#				to get the information.  This may have the
#				value "etc" or "nis".  If the value is given
#				as "etc" the the "hostfile" argument is read.
#				If the value is "nis" the list of hosts will
#				be retrieved from the nis server.
#				The default value is "etc".
#		- hostfile	An optional argument that specifies which
#				file to read as a hosts file.  This permits
#				users to define custom host files that contain
#				the list of hosts they most commonly work with.
#				The format for this file is the same as for
#				/etc/hosts (the default).
#
# Function:	hu:getRealHostName
# Synopsis:	
# Arguments:	- host		The host from which to retrieve the real
#				host name.
#
# Function:	hu:getIpAddress
# Synopsis:	
# Arguments:	- host		The host from which to retrieve the real
#				host name.
#		- fullname	A reference to a variable in which to store
#				the fully qualified host name.
#		- ipaddr	A reference to a variable in which to store
#				the IP address (in dot notation) of the host.
#		- hostfile	An optional parameter that specifies which
#				file to use as the hosts file.
# Function:	hu:getHostPlusDom
# Synopsis:	Given a hostname, this function attempts to return the
#		host+domain name (e.g., bonnie.engr.sgi.com --> bonnie.engr).
#		It first looks in it's cache to see if its' there.  If not,
#		then it tries to construct it.
# Arguments:	- host		The hostname for which to retrieve the
#				host+domain name.
#%COMMENT_END

#@package: HostUtil-Base	hu:getHosts hu:getRealHostName \
				hu:getIpAddress hu:getHostPlusDom

proc hu:getHosts { host {type etc} {hostfile /etc/hosts} } \
{
    global	_GD_hu

    if {[hu:getIpAddress $host hfn hpd hip $hostfile]} {
	if {[info exists _GD_hu($hip,hostlist)]} {
		return $_GD_hu($hip,hostlist)
	}
    }

    lappend data XFS_HOST:$host
    if {$type == "etc"} {
	lappend data XFS_GETHOSTS_SRC:ETC_HOSTS
	lappend data XFS_LOCAL_HOSTS_FILE:$hostfile
	if {[catch {set objects [xfsGetHostNames [join $data \n]]} err]} {
	    regsub -all -- "\n" [string trim $err] "\n\t" nerr
	    em:storeMsg hu error \
		"Unable to get host list from $host ($hostfile).\n\t$nerr"
	    return ""
	}
    } else {
	if {$type == "nis"} {
	    lappend data XFS_GETHOSTS_SRC:NIS_HOSTS
	} else {
	    lappend data XFS_GETHOSTS_SRC:ETC_NETGROUP
	}
	if {[catch {set objects [xfsGetHostNames [join $data \n]]} err]} {
	    return ""
	}
    } else {
	em:storeMsg hu error "Bad type ($type) passed to hu:getHosts."
	return ""
    }

    if {$hip != ""} {
	set _GD_hu($hip,hostlist) [exec sort -u << $objects | grep -v "\\.$"]
	return $_GD_hu($hip,hostlist)
    } else {
	return [exec sort -u << $objects | grep -v "\\.$"]
    }
}

proc hu:getRealHostName { {host localhost} } \
{
	lappend data "XFS_GET_SERVER_IP_ADDR:true"
	lappend data "XFS_GETHOSTS_SRC:ETC_HOSTS"
	lappend data "XFS_LOCAL_HOSTS_FILE:/etc/hosts"
	lappend data "XFS_HOST:$host"

	if {[catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
		return localhost
	}
	set ip [lindex [split $ret :] 1]

	lvarpop data 0 "XFS_GET_NAME_BY_IP_ADDR:$ip"
	if {[catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
		return localhost
	}
	set hostname [lindex [split $ret :] 1]

	return [string trim $hostname]
}

proc hu:getIpAddress { host fullname plusdom ipaddr {hostfile /etc/hosts} } \
{
	global	_GD_hu
	upvar $fullname	hfn
	upvar $plusdom	hpd
	upvar $ipaddr	hip

	if {[info exists _GD_hu($host,hfn)]} {
		set hfn $_GD_hu($host,hfn)
		set hip $_GD_hu($hfn,hip)
		set hpd $_GD_hu($hfn,hpd)
		return 1
	}

	set hip ""; set hfn ""; set hpd ""
	if {! [catch {set ret [exec /usr/sbin/nslookup $host]} err]} {
	    set ret [split $ret \n]
	    if {[lsearch $ret "*No address*"] == -1} {
		set nms [lmatch $ret "Name:*"]
		set addrs [lmatch $ret "Address:*"]
		if {$nms != ""} {
			set hfn [lindex [lindex $nms 0] 1]
			set hpd [hu:_hostPlusDomain $hfn]
		}
		if {[llength $addrs] == 2} {
			set hip [lindex [lindex $addrs 1] 1]
		}
		if {$hfn != "" && $hip != ""} {
		    set _GD_hu($host,hfn) $hfn
		    set _GD_hu($hfn,hfn) $hfn
		    set _GD_hu($hfn,hpd) $hpd
		    set _GD_hu($hfn,hip) $hip
		    return 1
		}
	    }
	}

	set hfn $host

        lappend data "XFS_HOST:$host"
        lappend data "XFS_GET_SERVER_IP_ADDR:true"
        lappend data "XFS_GETHOSTS_SRC:ETC_HOSTS"
        lappend data "XFS_LOCAL_HOSTS_FILE:$hostfile"
        if {! [catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
	    set hip [lindex [split $ret :] 1]

	    lvarpop data 1 "XFS_GET_NAME_BY_IP_ADDR:$hip"
	    if {! [catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
		set hfn [string trim [lindex [split $ret :] 1]]
	    }
	    set hpd [hu:_hostPlusDomain $hfn]
	    set _GD_hu($host,hfn) $hfn
	    set _GD_hu($hfn,hfn) $hfn
	    set _GD_hu($hfn,hpd) $hpd
	    set _GD_hu($hfn,hip) $hip

	    return 1
        }

	if {$hostfile != "/etc/hosts"} {
	    lvarpop data 3 "XFS_LOCAL_HOSTS_FILE:/etc/hosts"
	    if {! [catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
		set hip [lindex [split $ret :] 1]

		lvarpop data 1 "XFS_GET_NAME_BY_IP_ADDR:$hip"
		if {! [catch {set ret [xfsGetHostNames [join $data \n]]} err]} {
		    set hfn [string trim [lindex [split $ret :] 1]]
		}
		set hpd [hu:_hostPlusDomain $hfn]
		set _GD_hu($host,hfn) $hfn
		set _GD_hu($hfn,hfn) $hfn
		set _GD_hu($hfn,hpd) $hpd
		set _GD_hu($hfn,hip) $hip

		return 1
	    }
	}

	return 0
}

proc hu:getHostPlusDom { host } \
{
	global  _GD_hu

	if {[info exists _GD_hu($host,hpd)]} {
		return $_GD_hu($host,hpd)
	} else {
		return [hu:_hostPlusDomain $host]
	}
}

proc hu:_hostPlusDomain { hfn } \
{
	set h [split $hfn .]
	if {[llength $h] >= 2} {
		return [lindex $h 0].[lindex $h 1]
	} else {
		return $hfn
	}
}
#@packend