# See the safe.n man page for details.
#
# Copyright (c) 1996-1997 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: safe.tcl,v 1.10.2.7 2008/06/26 04:07:40 dgp Exp $

#
# The implementation is based on namespaces. These naming conventions
# are followed:
# Private procs starts with uppercase.
# Public  procs are exported and starts with lowercase
#

	# build new one
	set slave_auto_path {}
	set i 0
	foreach dir $access_path {
	    Set [PathToken $i $slave] $dir
	    lappend slave_auto_path "\$[PathToken $i]"
	    incr i
	}
	# Extend the access list with the paths used to look for Tcl
	# Modules. We safe the virtual form separately as well, as
	# syncing it with the slave has to be defered until the
	# necessary commands are present for setup.
	foreach dir [::tcl::tm::list] {
	    lappend access_path $dir
	    Set [PathToken $i $slave] $dir
	    lappend slave_auto_path "\$[PathToken $i]"
	    lappend slave_tm_path   "\$[PathToken $i]"
	    incr i
	}
	Set $nname $i
	Set [PathListName $slave] $access_path
	Set [VirtualPathListName $slave] $slave_auto_path
	Set [TmPathListName      $slave] $slave_tm_path

	Set [StaticsOkName $slave] $staticsok
	Set [NestedOkName $slave] $nestedok
	Set [DeleteHookName $slave] $deletehook

	SyncAccessPath $slave
    }

	# This alias lets the slave use the encoding names, convertfrom,
	# convertto, and system, but not "encoding system <name>" to set
	# the system encoding.

	::interp alias $slave encoding {} [namespace current]::AliasEncoding \
		$slave

	# Handling Tcl Modules, we need a restricted form of Glob.
	::interp alias $slave glob {} [namespace current]::AliasGlob \
		$slave

	# This alias lets the slave have access to a subset of the 'file'
	# command functionality.

	AliasSubset $slave file file dir.* join root.* ext.* tail \
		path.* split

	# This alias interposes on the 'exit' command and cleanly terminates
	# the slave.

	::interp alias $slave exit {} [namespace current]::interpDelete $slave

	# The allowed slave variables already have been set
	# by Tcl_MakeSafe(3)


	# Source init.tcl and tm.tcl into the slave, to get auto_load
	# and other procedures defined:

	if {[catch {::interp eval $slave\
		{source [file join $tcl_library init.tcl]}} msg]} {
	    Log $slave "can't source init.tcl ($msg)"
	    error "can't source init.tcl into slave $slave ($msg)"
	}

	if {[catch {::interp eval $slave \
		{source [file join $tcl_library tm.tcl]}} msg]} {
	    Log $slave "can't source tm.tcl ($msg)"
	    error "can't source tm.tcl into slave $slave ($msg)"
	}

	# Sync the paths used to search for Tcl modules. This can be
	# done only now, after tm.tcl was loaded.
	::interp eval $slave [list ::tcl::tm::add {*}[Set [TmPathListName $slave]]]

	return $slave
    }


    # Add (only if needed, avoid duplicates) 1 level of
    # sub directories to an existing path list.
    # Also removes non directories from the returned list.

    # returns the variable name of the complete path list
    proc PathListName {slave} {
	return "[InterpStateName $slave](access_path)"
    }
    # returns the variable name of the complete path list
    proc VirtualPathListName {slave} {
	return "[InterpStateName $slave](access_path_slave)"
    }
    # returns the variable name of the complete tm path list
    proc TmPathListName {slave} {
	return "[InterpStateName $slave](tm_path_slave)"
    }
    # returns the variable name of the number of items
    proc PathNumberName {slave} {
	return "[InterpStateName $slave](access_path,n)"
    }
    # returns the staticsok flag var name
    proc StaticsOkName {slave} {

	if {![file readable $file]} {
	    # don't tell the file path
	    error "not readable"
	}
    }

    # AliasGlob is the target of the "glob" alias in safe interpreters.

    proc AliasGlob {slave args} {
	Log $slave "GLOB ! $args" NOTICE
	set cmd {}
	set at 0

	set dir        {}
	set virtualdir {}

	while {$at < [llength $args]} {
	    switch -glob -- [set opt [lindex $args $at]] {
		-nocomplain -
		-join       { lappend cmd $opt ; incr at }
		-directory  {
		    lappend cmd $opt ; incr at
		    set virtualdir [lindex $args $at]

		    # get the real path from the virtual one.
		    if {[catch {set dir [TranslatePath $slave $virtualdir]} msg]} {
			Log $slave $msg
			return -code error "permission denied"
		    }
		    # check that the path is in the access path of that slave
		    if {[catch {DirInAccessPath $slave $dir} msg]} {
			Log $slave $msg
			return -code error "permission denied"
		    }
		    lappend cmd $dir ; incr at
		}
		pkgIndex.tcl {
		    # Oops, this is globbing a subdirectory in regular
		    # package search. That is not wanted. Abort,
		    # handler does catch already (because glob was not
		    # defined before). See package.tcl, lines 484ff in
		    # tclPkgUnknown.
		    error "unknown command glob"
		}
		-* {
		    Log $slave "Safe base rejecting glob option '$opt'"
		    error      "Safe base rejecting glob option '$opt'"
		}
		default {
		    lappend cmd $opt ; incr at
		}
	    }
	}

	Log $slave "GLOB = $cmd" NOTICE

	if {[catch {::interp invokehidden $slave glob {*}$cmd} msg]} {
	    Log $slave $msg
	    return -code error "script error"
	}

	Log $slave "GLOB @ $msg" NOTICE

	# Translate path back to what the slave should see.
	set res {}
	foreach p $msg {
	    regsub -- ^$dir $p $virtualdir p
	    lappend res $p
	}

	Log $slave "GLOB @ $res" NOTICE
	return $res
    }

    # AliasSource is the target of the "source" alias in safe interpreters.

    proc AliasSource {slave args} {

	set argc [llength $args]
	# Extended for handling of Tcl Modules to allow not only
	# "source filename", but "source -encoding E filename" as
	# well.
	if {[lindex $args 0] eq "-encoding"} {
	    incr argc -2
	    set encoding [lrange $args 0 1]
	    set at 2
	} else {
	    set at 0
	    set encoding {}
	}
	if {$argc != 1} {
	    set msg "wrong # args: should be \"source ?-encoding E? fileName\""
	    Log $slave "$msg ($args)"
	    return -code error $msg
	}
	set file [lindex $args $at]
	
	# get the real path from the virtual one.
	if {[catch {set file [TranslatePath $slave $file]} msg]} {
	    Log $slave $msg
	    return -code error "permission denied"
	}
	
	# check that the path is in the access path of that slave
	if {[catch {FileInAccessPath $slave $file} msg]} {
	    Log $slave $msg
	    return -code error "permission denied"
	}

	# do the checks on the filename :
	if {[catch {CheckFileName $slave $file} msg]} {
	    Log $slave "$file:$msg"
	    return -code error $msg
	}

	# passed all the tests , lets source it:
	if {[catch {::interp invokehidden $slave source {*}$encoding $file} msg]} {
	    Log $slave $msg
	    return -code error "script error"
	}
	return $msg
    }

    # AliasLoad is the target of the "load" alias in safe interpreters.

	    lappend norm_access_path [file normalize $path]
	}

	if {[lsearch -exact $norm_access_path $norm_parent] == -1} {
	    error "\"$file\": not in access_path"
	}
    }

    proc DirInAccessPath {slave dir} {
	set access_path [GetAccessPath $slave]

	if {[file isfile $dir]} {
	    error "\"$dir\": is a file"
	}

	# Normalize paths for comparison since lsearch knows nothing of
	# potential pathname anomalies.
	set norm_dir [file normalize $dir]
	foreach path $access_path {
	    lappend norm_access_path [file normalize $path]
	}

	if {[lsearch -exact $norm_access_path $norm_dir] == -1} {
	    error "\"$dir\": not in access_path"
	}
    }

    # This procedure enables access from a safe interpreter to only a subset of
    # the subcommands of a command:

    proc Subset {slave command okpat args} {
	set subcommand [lindex $args 0]
	if {[regexp $okpat $subcommand]} {