# safe.tcl --
#
# This file provide a safe loading/sourcing mechanism for safe interpreters.
# It implements a virtual path mechanism to hide the real pathnames from the
# child. It runs in a parent interpreter and sets up data structure and
# aliases that will be invoked when used from a child interpreter.
#
# 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.
#
# The implementation is based on namespaces. These naming conventions are
# followed:
# Private procs starts with uppercase.
# Public procs are exported and starts with lowercase
#
# Needed utilities package
package require opt 0.4.8
# Create the safe namespace
namespace eval ::safe {
# Exported API:
namespace export interpCreate interpInit interpConfigure interpDelete \
interpAddToAccessPath interpFindInAccessPath setLogCmd
}
# Helper function to resolve the dual way of specifying staticsok (either
# by -noStatics or -statics 0)
proc ::safe::InterpStatics {} {
foreach v {Args statics noStatics} {
upvar $v $v
}
set flag [::tcl::OptProcArgGiven -noStatics]
if {$flag && (!$noStatics == !$statics)
&& ([::tcl::OptProcArgGiven -statics])} {
return -code error\
"conflicting values given for -statics and -noStatics"
}
if {$flag} {
return [expr {!$noStatics}]
} else {
return $statics
}
}
# Helper function to resolve the dual way of specifying nested loading
# (either by -nestedLoadOk or -nested 1)
proc ::safe::InterpNested {} {
foreach v {Args nested nestedLoadOk} {
upvar $v $v
}
set flag [::tcl::OptProcArgGiven -nestedLoadOk]
# note that the test here is the opposite of the "InterpStatics" one
# (it is not -noNested... because of the wanted default value)
if {$flag && (!$nestedLoadOk != !$nested)
&& ([::tcl::OptProcArgGiven -nested])} {
return -code error\
"conflicting values given for -nested and -nestedLoadOk"
}
if {$flag} {
# another difference with "InterpStatics"
return $nestedLoadOk
} else {
return $nested
}
}
####
#
# API entry points that needs argument parsing :
#
####
# Interface/entry point function and front end for "Create"
proc ::safe::interpCreate {args} {
set Args [::tcl::OptKeyParse ::safe::interpCreate $args]
RejectExcessColons $slave
InterpCreate $slave $accessPath \
[InterpStatics] [InterpNested] $deleteHook
}
proc ::safe::interpInit {args} {
set Args [::tcl::OptKeyParse ::safe::interpIC $args]
if {![::interp exists $slave]} {
return -code error "\"$slave\" is not an interpreter"
}
RejectExcessColons $slave
InterpInit $slave $accessPath \
[InterpStatics] [InterpNested] $deleteHook
}
# Check that the given child is "one of us"
proc ::safe::CheckInterp {child} {
namespace upvar ::safe [VarName $child] state
if {![info exists state] || ![::interp exists $child]} {
return -code error \
"\"$child\" is not an interpreter managed by ::safe::"
}
}
# Interface/entry point function and front end for "Configure". This code
# is awfully pedestrian because it would need more coupling and support
# between the way we store the configuration values in safe::interp's and
# the Opt package. Obviously we would like an OptConfigure to avoid
# duplicating all this code everywhere.
# -> TODO (the app should share or access easily the program/value stored
# by opt)
# This is even more complicated by the boolean flags with no values that
# we had the bad idea to support for the sake of user simplicity in
# create/init but which makes life hard in configure...
# So this will be hopefully written and some integrated with opt1.0
# (hopefully for tcl8.1 ?)
proc ::safe::interpConfigure {args} {
switch [llength $args] {
1 {
# If we have exactly 1 argument the semantic is to return all
# the current configuration. We still call OptKeyParse though
# we know that "child" is our given argument because it also
# checks for the "-help" option.
set Args [::tcl::OptKeyParse ::safe::interpIC $args]
CheckInterp $slave
namespace upvar ::safe [VarName $slave] state
return [join [list \
[list -accessPath $state(access_path)] \
[list -statics $state(staticsok)] \
[list -nested $state(nestedok)] \
[list -deleteHook $state(cleanupHook)]]]
}
2 {
# If we have exactly 2 arguments the semantic is a "configure
# get"
lassign $args slave arg
# get the flag sub program (we 'know' about Opt's internal
# representation of data)
set desc [lindex [::tcl::OptKeyGetDesc ::safe::interpIC] 2]
set hits [::tcl::OptHits desc $arg]
if {$hits > 1} {
return -code error [::tcl::OptAmbigous $desc $arg]
} elseif {$hits == 0} {
return -code error [::tcl::OptFlagUsage $desc $arg]
}
CheckInterp $slave
namespace upvar ::safe [VarName $slave] state
set item [::tcl::OptCurDesc $desc]
set name [::tcl::OptName $item]
switch -exact -- $name {
-accessPath {
return [list -accessPath $state(access_path)]
}
-statics {
return [list -statics $state(staticsok)]
}
-nested {
return [list -nested $state(nestedok)]
}
-deleteHook {
return [list -deleteHook $state(cleanupHook)]
}
-noStatics {
# it is most probably a set in fact but we would need
# then to jump to the set part and it is not *sure*
# that it is a set action that the user want, so force
# it to use the unambigous -statics ?value? instead:
return -code error\
"ambigous query (get or set -noStatics ?)\
use -statics instead"
}
-nestedLoadOk {
return -code error\
"ambigous query (get or set -nestedLoadOk ?)\
use -nested instead"
}
default {
return -code error "unknown flag $name (bug)"
}
}
}
default {
# Otherwise we want to parse the arguments like init and
# create did
set Args [::tcl::OptKeyParse ::safe::interpIC $args]
CheckInterp $slave
namespace upvar ::safe [VarName $slave] state
# Get the current (and not the default) values of whatever has
# not been given:
if {![::tcl::OptProcArgGiven -accessPath]} {
set doreset 0
set accessPath $state(access_path)
} else {
set doreset 1
}
if {
![::tcl::OptProcArgGiven -statics]
&& ![::tcl::OptProcArgGiven -noStatics]
} then {
set statics $state(staticsok)
} else {
set statics [InterpStatics]
}
if {
[::tcl::OptProcArgGiven -nested] ||
[::tcl::OptProcArgGiven -nestedLoadOk]
} then {
set nested [InterpNested]
} else {
set nested $state(nestedok)
}
if {![::tcl::OptProcArgGiven -deleteHook]} {
set deleteHook $state(cleanupHook)
}
# we can now reconfigure :
InterpSetConfig $slave $accessPath $statics $nested $deleteHook
# auto_reset the child (to completly synch the new access_path)
if {$doreset} {
if {[catch {::interp eval $slave {auto_reset}} msg]} {
Log $slave "auto_reset failed: $msg"
} else {
Log $slave "successful auto_reset" NOTICE
}
# Sync the paths used to search for Tcl modules.
::interp eval $slave {tcl::tm::path remove {*}[tcl::tm::list]}
if {[llength $state(tm_path_slave)] > 0} {
::interp eval $slave [list \
::tcl::tm::add {*}[lreverse $state(tm_path_slave)]]
}
# Remove stale "package ifneeded" data for non-loaded packages.
# - Not for loaded packages, because "package forget" erases
# data from "package provide" as well as "package ifneeded".
# - This is OK because the script cannot reload any version of
# the package unless it first does "package forget".
foreach pkg [::interp eval $slave {package names}] {
if {[::interp eval $slave [list package provide $pkg]] eq ""} {
::interp eval $slave [list package forget $pkg]
}
}
}
return
}
}
}
####
#
# Functions that actually implements the exported APIs
#
####
#
# safe::InterpCreate : doing the real job
#
# This procedure creates a safe interpreter and initializes it with the safe
# base aliases.
# NB: child name must be simple alphanumeric string, no spaces, no (), no
# {},... {because the state array is stored as part of the name}
#
# Returns the child name.
#
# Optional Arguments :
# + child name : if empty, generated name will be used
# + access_path: path list controlling where load/source can occur,
# if empty: the parent auto_path will be used.
# + staticsok : flag, if 0 :no static package can be loaded (load {} Xxx)
# if 1 :static packages are ok.
# + nestedok: flag, if 0 :no loading to sub-sub interps (load xx xx sub)
# if 1 : multiple levels are ok.
# use the full name and no indent so auto_mkIndex can find us
proc ::safe::InterpCreate {
child
access_path
staticsok
nestedok
deletehook
} {
# Create the child.
# If evaluated in ::safe, the interpreter command for foo is ::foo;
# but for foo::bar is safe::foo::bar. So evaluate in :: instead.
if {$child ne ""} {
namespace eval :: [list ::interp create -safe $child]
} else {
# empty argument: generate child name
set child [::interp create -safe]
}
Log $child "Created" NOTICE
# Initialize it. (returns child name)
InterpInit $child $access_path $staticsok $nestedok $deletehook
}
#
# InterpSetConfig (was setAccessPath) :
# Sets up child virtual auto_path and corresponding structure within
# the parent. Also sets the tcl_library in the child to be the first
# directory in the path.
# NB: If you change the path after the child has been initialized you
# probably need to call "auto_reset" in the child in order that it gets
# the right auto_index() array values.
proc ::safe::InterpSetConfig {child access_path staticsok nestedok deletehook} {
global auto_path
# determine and store the access path if empty
if {$access_path eq ""} {
set access_path $auto_path
# Make sure that tcl_library is in auto_path and at the first
# position (needed by setAccessPath)
set where [lsearch -exact $access_path [info library]]
if {$where < 0} {
# not found, add it.
set access_path [linsert $access_path 0 [info library]]
Log $child "tcl_library was not in auto_path,\
added it to slave's access_path" NOTICE
} elseif {$where != 0} {
# not first, move it first
set access_path [linsert \
[lreplace $access_path $where $where] \
0 [info library]]
Log $child "tcl_libray was not in first in auto_path,\
moved it to front of slave's access_path" NOTICE
}
# Add 1st level sub dirs (will searched by auto loading from tcl
# code in the child using glob and thus fail, so we add them here
# so by default it works the same).
set access_path [AddSubDirs $access_path]
}
Log $child "Setting accessPath=($access_path) staticsok=$staticsok\
nestedok=$nestedok deletehook=($deletehook)" NOTICE
namespace upvar ::safe [VarName $child] state
# clear old autopath if it existed
# build new one
# Extend the access list with the paths used to look for Tcl Modules.
# We save the virtual form separately as well, as syncing it with the
# child has to be deferred until the necessary commands are present for
# setup.
set norm_access_path {}
set slave_access_path {}
set map_access_path {}
set remap_access_path {}
set slave_tm_path {}
set i 0
foreach dir $access_path {
set token [PathToken $i]
lappend slave_access_path $token
lappend map_access_path $token $dir
lappend remap_access_path $dir $token
lappend norm_access_path [file normalize $dir]
incr i
}
set morepaths [::tcl::tm::list]
set firstpass 1
while {[llength $morepaths]} {
set addpaths $morepaths
set morepaths {}
foreach dir $addpaths {
# Prevent the addition of dirs on the tm list to the
# result if they are already known.
if {[dict exists $remap_access_path $dir]} {
if {$firstpass} {
# $dir is in [::tcl::tm::list] and belongs in the slave_tm_path.
# Later passes handle subdirectories, which belong in the
# access path but not in the module path.
lappend slave_tm_path [dict get $remap_access_path $dir]
}
continue
}
set token [PathToken $i]
lappend access_path $dir
lappend slave_access_path $token
lappend map_access_path $token $dir
lappend remap_access_path $dir $token
lappend norm_access_path [file normalize $dir]
if {$firstpass} {
# $dir is in [::tcl::tm::list] and belongs in the slave_tm_path.
# Later passes handle subdirectories, which belong in the
# access path but not in the module path.
lappend slave_tm_path $token
}
incr i
# [Bug 2854929]
# Recursively find deeper paths which may contain
# modules. Required to handle modules with names like
# 'platform::shell', which translate into
# 'platform/shell-X.tm', i.e arbitrarily deep
# subdirectories.
lappend morepaths {*}[glob -nocomplain -directory $dir -type d *]
}
set firstpass 0
}
set state(access_path) $access_path
set state(access_path,map) $map_access_path
set state(access_path,remap) $remap_access_path
set state(access_path,norm) $norm_access_path
set state(access_path,slave) $slave_access_path
set state(tm_path_slave) $slave_tm_path
set state(staticsok) $staticsok
set state(nestedok) $nestedok
set state(cleanupHook) $deletehook
SyncAccessPath $child
return
}
#
#
# FindInAccessPath:
# Search for a real directory and returns its virtual Id (including the
# "$")
proc ::safe::interpFindInAccessPath {child path} {
CheckInterp $child
namespace upvar ::safe [VarName $child] state
if {![dict exists $state(access_path,remap) $path]} {
return -code error "$path not found in access path"
}
return [dict get $state(access_path,remap) $path]
}
#
# addToAccessPath:
# add (if needed) a real directory to access path and return its
# virtual token (including the "$").
proc ::safe::interpAddToAccessPath {child path} {
# first check if the directory is already in there
# (inlined interpFindInAccessPath).
CheckInterp $child
namespace upvar ::safe [VarName $child] state
if {[dict exists $state(access_path,remap) $path]} {
return [dict get $state(access_path,remap) $path]
}
# new one, add it:
set token [PathToken [llength $state(access_path)]]
lappend state(access_path) $path
lappend state(access_path,slave) $token
lappend state(access_path,map) $token $path
lappend state(access_path,remap) $path $token
lappend state(access_path,norm) [file normalize $path]
SyncAccessPath $child
return $token
}
# This procedure applies the initializations to an already existing
# interpreter. It is useful when you want to install the safe base aliases
# into a preexisting safe interpreter.
proc ::safe::InterpInit {
child
access_path
staticsok
nestedok
deletehook
} {
# Configure will generate an access_path when access_path is empty.
InterpSetConfig $child $access_path $staticsok $nestedok $deletehook
# NB we need to add [namespace current], aliases are always absolute
# paths.
# These aliases let the child load files to define new commands
# This alias lets the child use the encoding names, convertfrom,
# convertto, and system, but not "encoding system <name>" to set the
# system encoding.
# Handling Tcl Modules, we need a restricted form of Glob.
# This alias interposes on the 'exit' command and cleanly terminates
# the child.
foreach {command alias} {
source AliasSource
load AliasLoad
encoding AliasEncoding
exit interpDelete
glob AliasGlob
} {
::interp alias $child $command {} [namespace current]::$alias $child
}
# This alias lets the child have access to a subset of the 'file'
# command functionality.
::interp expose $child file
foreach subcommand {dirname extension rootname tail} {
::interp alias $child ::tcl::file::$subcommand {} \
::safe::AliasFileSubcommand $child $subcommand
}
foreach subcommand {
atime attributes copy delete executable exists isdirectory isfile
link lstat mtime mkdir nativename normalize owned readable readlink
rename size stat tempfile type volumes writable
} {
::interp alias $child ::tcl::file::$subcommand {} \
::safe::BadSubcommand $child file $subcommand
}
# Subcommands of info
foreach {subcommand alias} {
nameofexecutable AliasExeName
} {
::interp alias $child ::tcl::info::$subcommand \
{} [namespace current]::$alias $child
}
# The allowed child variables already have been set by Tcl_MakeSafe(3)
# Source init.tcl and tm.tcl into the child, to get auto_load and
# other procedures defined:
if {[catch {::interp eval $child {
source [file join $tcl_library init.tcl]
}} msg opt]} {
Log $child "can't source init.tcl ($msg)"
return -options $opt "can't source init.tcl into slave $child ($msg)"
}
if {[catch {::interp eval $child {
source [file join $tcl_library tm.tcl]
}} msg opt]} {
Log $child "can't source tm.tcl ($msg)"
return -options $opt "can't source tm.tcl into slave $child ($msg)"
}
# Sync the paths used to search for Tcl modules. This can be done only
# now, after tm.tcl was loaded.
namespace upvar ::safe [VarName $child] state
if {[llength $state(tm_path_slave)] > 0} {
::interp eval $child [list \
::tcl::tm::add {*}[lreverse $state(tm_path_slave)]]
}
return $child
}
# Add (only if needed, avoid duplicates) 1 level of sub directories to an
# existing path list. Also removes non directories from the returned
# list.
proc ::safe::AddSubDirs {pathList} {
set res {}
foreach dir $pathList {
if {[file isdirectory $dir]} {
# check that we don't have it yet as a children of a previous
# dir
if {$dir ni $res} {
lappend res $dir
}
foreach sub [glob -directory $dir -nocomplain *] {
if {[file isdirectory $sub] && ($sub ni $res)} {
# new sub dir, add it !
lappend res $sub
}
}
}
}
return $res
}
# This procedure deletes a safe interpreter managed by Safe Tcl and cleans up
# associated state.
# - The command will also delete non-Safe-Base interpreters.
# - This is regrettable, but to avoid breaking existing code this should be
# amended at the next major revision by uncommenting "CheckInterp".
proc ::safe::interpDelete {child} {
Log $child "About to delete" NOTICE
# CheckInterp $child
namespace upvar ::safe [VarName $child] state
# When an interpreter is deleted with [interp delete], any sub-interpreters
# are deleted automatically, but this leaves behind their data in the Safe
# Base. To clean up properly, we call safe::interpDelete recursively on each
# Safe Base sub-interpreter, so each one is deleted cleanly and not by
# the automatic mechanism built into [interp delete].
foreach sub [interp children $child] {
if {[info exists ::safe::[VarName [list $child $sub]]]} {
::safe::interpDelete [list $child $sub]
}
}
# If the child has a cleanup hook registered, call it. Check the
# existance because we might be called to delete an interp which has
# not been registered with us at all
if {[info exists state(cleanupHook)]} {
set hook $state(cleanupHook)
if {[llength $hook]} {
# remove the hook now, otherwise if the hook calls us somehow,
# we'll loop
unset state(cleanupHook)
try {
{*}$hook $child
} on error err {
Log $child "Delete hook error ($err)"
}
}
}
# Discard the global array of state associated with the child, and
# delete the interpreter.
if {[info exists state]} {
unset state
}
# if we have been called twice, the interp might have been deleted
# already
if {[::interp exists $child]} {
::interp delete $child
Log $child "Deleted" NOTICE
}
return
}
# Set (or get) the logging mecanism
proc ::safe::setLogCmd {args} {
variable Log
set la [llength $args]
if {$la == 0} {
return $Log
} elseif {$la == 1} {
set Log [lindex $args 0]
} else {
set Log $args
}
if {$Log eq ""} {
# Disable logging completely. Calls to it will be compiled out
# of all users.
proc ::safe::Log {args} {}
} else {
# Activate logging, define proper command.
proc ::safe::Log {child msg {type ERROR}} {
variable Log
{*}$Log "$type for slave $child : $msg"
return
}
}
}
# ------------------- END OF PUBLIC METHODS ------------
#
# Sets the child auto_path to the parent recorded value. Also sets
# tcl_library to the first token of the virtual path.
#
proc ::safe::SyncAccessPath {child} {
namespace upvar ::safe [VarName $child] state
set slave_access_path $state(access_path,slave)
::interp eval $child [list set auto_path $slave_access_path]
Log $child "auto_path in $child has been set to $slave_access_path"\
NOTICE
# This code assumes that info library is the first element in the
# list of auto_path's. See -> InterpSetConfig for the code which
# ensures this condition.
::interp eval $child [list \
set tcl_library [lindex $slave_access_path 0]]
}
# Returns the virtual token for directory number N.
proc ::safe::PathToken {n} {
# We need to have a ":" in the token string so [file join] on the
# mac won't turn it into a relative path.
return "\$p(:$n:)" ;# Form tested by case 7.2
}
#
# translate virtual path into real path
#
proc ::safe::TranslatePath {child path} {
namespace upvar ::safe [VarName $child] state
# somehow strip the namespaces 'functionality' out (the danger is that
# we would strip valid macintosh "../" queries... :
if {[string match "*::*" $path] || [string match "*..*" $path]} {
return -code error "invalid characters in path $path"
}
# Use a cached map instead of computed local vars and subst.
return [string map $state(access_path,map) $path]
}
# file name control (limit access to files/resources that should be a
# valid tcl source file)
proc ::safe::CheckFileName {child file} {
# This used to limit what can be sourced to ".tcl" and forbid files
# with more than 1 dot and longer than 14 chars, but I changed that
# for 8.4 as a safe interp has enough internal protection already to
# allow sourcing anything. - hobbs
if {![file exists $file]} {
# don't tell the file path
return -code error "no such file or directory"
}
if {![file readable $file]} {
# don't tell the file path
return -code error "not readable"
}
}
# AliasFileSubcommand handles selected subcommands of [file] in safe
# interpreters that are *almost* safe. In particular, it just acts to
# prevent discovery of what home directories exist.
proc ::safe::AliasFileSubcommand {child subcommand name} {
if {[string match ~* $name]} {
set name ./$name
}
tailcall ::interp invokehidden $child tcl:file:$subcommand $name
}
# AliasGlob is the target of the "glob" alias in safe interpreters.
proc ::safe::AliasGlob {child args} {
Log $child "GLOB ! $args" NOTICE
set cmd {}
set at 0
array set got {
-directory 0
-nocomplain 0
-join 0
-tails 0
-- 0
}
if {$::tcl_platform(platform) eq "windows"} {
set dirPartRE {^(.*)[\\/]([^\\/]*)$}
} else {
set dirPartRE {^(.*)/([^/]*)$}
}
set dir {}
set virtualdir {}
while {$at < [llength $args]} {
switch -glob -- [set opt [lindex $args $at]] {
-nocomplain - -- - -tails {
lappend cmd $opt
set got($opt) 1
incr at
}
-join {
set got($opt) 1
incr at
}
-types - -type {
lappend cmd -types [lindex $args [incr at]]
incr at
}
-directory {
if {$got($opt)} {
return -code error \
{"-directory" cannot be used with "-path"}
}
set got($opt) 1
set virtualdir [lindex $args [incr at]]
incr at
}
-* {
Log $child "Safe base rejecting glob option '$opt'"
return -code error "Safe base rejecting glob option '$opt'"
}
default {
break
}
}
if {$got(--)} break
}
# Get the real path from the virtual one and check that the path is in the
# access path of that child. Done after basic argument processing so that
# we know if -nocomplain is set.
if {$got(-directory)} {
try {
set dir [TranslatePath $child $virtualdir]
DirInAccessPath $child $dir
} on error msg {
Log $child $msg
if {$got(-nocomplain)} return
return -code error "permission denied"
}
if {$got(--)} {
set cmd [linsert $cmd end-1 -directory $dir]
} else {
lappend cmd -directory $dir
}
} else {
# The code after this "if ... else" block would conspire to return with
# no results in this case, if it were allowed to proceed. Instead,
# return now and reduce the number of cases to be considered later.
Log $child {option -directory must be supplied}
if {$got(-nocomplain)} return
return -code error "permission denied"
}
# Apply the -join semantics ourselves.
if {$got(-join)} {
set args [lreplace $args $at end [join [lrange $args $at end] "/"]]
}
# Process the pattern arguments. If we've done a join there is only one
# pattern argument.
set firstPattern [llength $cmd]
foreach opt [lrange $args $at end] {
if {![regexp $dirPartRE $opt -> thedir thefile]} {
set thedir .
# The *.tm search comes here.
}
# "Special" treatment for (joined) argument {*/pkgIndex.tcl}.
# Do the expansion of "*" here, and filter out any directories that are
# not in the access path. The outcome is to lappend to cmd a path of
# the form $virtualdir/subdir/pkgIndex.tcl for each subdirectory subdir,
# after removing any subdir that are not in the access path.
if {($thedir eq "*") && ($thefile eq "pkgIndex.tcl")} {
set mapped 0
foreach d [glob -directory [TranslatePath $child $virtualdir] \
-types d -tails *] {
catch {
DirInAccessPath $child \
[TranslatePath $child [file join $virtualdir $d]]
lappend cmd [file join $d $thefile]
set mapped 1
}
}
if {$mapped} continue
# Don't [continue] if */pkgIndex.tcl has no matches in the access
# path. The pattern will now receive the same treatment as a
# "non-special" pattern (and will fail because it includes a "*" in
# the directory name).
}
# Any directory pattern that is not an exact (i.e. non-glob) match to a
# directory in the access path will be rejected here.
# - Rejections include any directory pattern that has glob matching
# patterns "*", "?", backslashes, braces or square brackets, (UNLESS
# it corresponds to a genuine directory name AND that directory is in
# the access path).
# - The only "special matching characters" that remain in patterns for
# processing by glob are in the filename tail.
# - [file join $anything ~${foo}] is ~${foo}, which is not an exact
# match to any directory in the access path. Hence directory patterns
# that begin with "~" are rejected here. Tests safe-16.[5-8] check
# that "file join" remains as required and does not expand ~${foo}.
# - Bug [3529949] relates to unwanted expansion of ~${foo} and this is
# how the present code avoids the bug. All tests safe-16.* relate.
try {
DirInAccessPath $child [TranslatePath $child \
[file join $virtualdir $thedir]]
} on error msg {
Log $child $msg
if {$got(-nocomplain)} continue
return -code error "permission denied"
}
lappend cmd $opt
}
Log $child "GLOB = $cmd" NOTICE
if {$got(-nocomplain) && [llength $cmd] eq $firstPattern} {
return
}
try {
# >>>>>>>>>> HERE'S THE CALL TO SAFE INTERP GLOB <<<<<<<<<<
# - Pattern arguments added to cmd have NOT been translated from tokens.
# Only the virtualdir is translated (to dir).
# - In the pkgIndex.tcl case, there is no "*" in the pattern arguments,
# which are a list of names each with tail pkgIndex.tcl. The purpose
# of the call to glob is to remove the names for which the file does
# not exist.
set entries [::interp invokehidden $child glob {*}$cmd]
} on error msg {
# This is the only place that a call with -nocomplain and no invalid
# "dash-options" can return an error.
Log $child $msg
return -code error "script error"
}
Log $child "GLOB < $entries" NOTICE
# Translate path back to what the child should see.
set res {}
set l [string length $dir]
foreach p $entries {
if {[string equal -length $l $dir $p]} {
set p [string replace $p 0 [expr {$l-1}] $virtualdir]
}
lappend res $p
}
Log $child "GLOB > $res" NOTICE
return $res
}
# AliasSource is the target of the "source" alias in safe interpreters.
proc ::safe::AliasSource {child 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 [lindex $args 1]
set at 2
if {$encoding eq "identity"} {
Log $child "attempt to use the identity encoding"
return -code error "permission denied"
}
} else {
set at 0
set encoding {}
}
if {$argc != 1} {
set msg "wrong # args: should be \"source ?-encoding E? fileName\""
Log $child "$msg ($args)"
return -code error $msg
}
set file [lindex $args $at]
# get the real path from the virtual one.
if {[catch {
set realfile [TranslatePath $child $file]
} msg]} {
Log $child $msg
return -code error "permission denied"
}
# check that the path is in the access path of that child
if {[catch {
FileInAccessPath $child $realfile
} msg]} {
Log $child $msg
return -code error "permission denied"
}
# Check that the filename exists and is readable. If it is not, deliver
# this -errorcode so that caller in tclPkgUnknown does not write a message
# to tclLog. Has no effect on other callers of ::source, which are in
# "package ifneeded" scripts.
if {[catch {
CheckFileName $child $realfile
} msg]} {
Log $child "$realfile:$msg"
return -code error -errorcode {POSIX EACCES} $msg
}
# Passed all the tests, lets source it. Note that we do this all manually
# because we want to control [info script] in the child so information
# doesn't leak so much. [Bug 2913625]
set old [::interp eval $child {info script}]
set replacementMsg "script error"
set code [catch {
set f [open $realfile]
fconfigure $f -eofchar "\032 {}"
if {$encoding ne ""} {
fconfigure $f -encoding $encoding
}
set contents [read $f]
close $f
::interp eval $child [list info script $file]
} msg opt]
if {$code == 0} {
set code [catch {::interp eval $child $contents} msg opt]
set replacementMsg $msg
}
catch {interp eval $child [list info script $old]}
# Note that all non-errors are fine result codes from [source], so we must
# take a little care to do it properly. [Bug 2923613]
if {$code == 1} {
Log $child $msg
return -code error $replacementMsg
}
return -code $code -options $opt $msg
}
# AliasLoad is the target of the "load" alias in safe interpreters.
proc ::safe::AliasLoad {child file args} {
set argc [llength $args]
if {$argc > 2} {
set msg "load error: too many arguments"
Log $child "$msg ($argc) {$file $args}"
return -code error $msg
}
# package name (can be empty if file is not).
set package [lindex $args 0]
namespace upvar ::safe [VarName $child] state
# Determine where to load. load use a relative interp path and {}
# means self, so we can directly and safely use passed arg.
set target [lindex $args 1]
if {$target ne ""} {
# we will try to load into a sub sub interp; check that we want to
# authorize that.
if {!$state(nestedok)} {
Log $child "loading to a sub interp (nestedok)\
disabled (trying to load $package to $target)"
return -code error "permission denied (nested load)"
}
}
# Determine what kind of load is requested
if {$file eq ""} {
# static package loading
if {$package eq ""} {
set msg "load error: empty filename and no package name"
Log $child $msg
return -code error $msg
}
if {!$state(staticsok)} {
Log $child "static packages loading disabled\
(trying to load $package to $target)"
return -code error "permission denied (static package)"
}
} else {
# file loading
# get the real path from the virtual one.
try {
set file [TranslatePath $child $file]
} on error msg {
Log $child $msg
return -code error "permission denied"
}
# check the translated path
try {
FileInAccessPath $child $file
} on error msg {
Log $child $msg
return -code error "permission denied (path)"
}
}
try {
return [::interp invokehidden $child load $file $package $target]
} on error msg {
# Some packages return no error message.
set msg0 "load of binary library for package $package failed"
if {$msg eq {}} {
set msg $msg0
} else {
set msg "$msg0: $msg"
}
Log $child $msg
return -code error $msg
}
}
# FileInAccessPath raises an error if the file is not found in the list of
# directories contained in the (parent side recorded) child's access path.
# the security here relies on "file dirname" answering the proper
# result... needs checking ?
proc ::safe::FileInAccessPath {child file} {
namespace upvar ::safe [VarName $child] state
set access_path $state(access_path)
if {[file isdirectory $file]} {
return -code error "\"$file\": is a directory"
}
set parent [file dirname $file]
# Normalize paths for comparison since lsearch knows nothing of
# potential pathname anomalies.
set norm_parent [file normalize $parent]
namespace upvar ::safe [VarName $child] state
if {$norm_parent ni $state(access_path,norm)} {
return -code error "\"$file\": not in access_path"
}
}
proc ::safe::DirInAccessPath {child dir} {
namespace upvar ::safe [VarName $child] state
set access_path $state(access_path)
if {[file isfile $dir]} {
return -code error "\"$dir\": is a file"
}
# Normalize paths for comparison since lsearch knows nothing of
# potential pathname anomalies.
set norm_dir [file normalize $dir]
namespace upvar ::safe [VarName $child] state
if {$norm_dir ni $state(access_path,norm)} {
return -code error "\"$dir\": not in access_path"
}
}
# This procedure is used to report an attempt to use an unsafe member of an
# ensemble command.
proc ::safe::BadSubcommand {child command subcommand args} {
set msg "not allowed to invoke subcommand $subcommand of $command"
Log $child $msg
return -code error -errorcode {TCL SAFE SUBCOMMAND} $msg
}
# AliasEncoding is the target of the "encoding" alias in safe interpreters.
proc ::safe::AliasEncoding {child option args} {
# Note that [encoding dirs] is not supported in safe children at all
set subcommands {convertfrom convertto names system}
try {
set option [tcl::prefix match -error [list -level 1 -errorcode \
[list TCL LOOKUP INDEX option $option]] $subcommands $option]
# Special case: [encoding system] ok, but [encoding system foo] not
if {$option eq "system" && [llength $args]} {
return -code error -errorcode {TCL WRONGARGS} \
"wrong # args: should be \"encoding system\""
}
} on error {msg options} {
Log $child $msg
return -options $options $msg
}
tailcall ::interp invokehidden $child encoding $option {*}$args
}
# Various minor hiding of platform features. [Bug 2913625]
proc ::safe::AliasExeName {child} {
return ""
}
# ------------------------------------------------------------------------------
# Using Interpreter Names with Namespace Qualifiers
# ------------------------------------------------------------------------------
# (1) We wish to preserve compatibility with existing code, in which Safe Base
# interpreter names have no namespace qualifiers.
# (2) safe::interpCreate and the rest of the Safe Base previously could not
# accept namespace qualifiers in an interpreter name.
# (3) The interp command will accept namespace qualifiers in an interpreter
# name, but accepts distinct interpreters that will have the same command
# name (e.g. foo, ::foo, and :::foo) (bug 66c2e8c974).
# (4) To satisfy these constraints, Safe Base interpreter names will be fully
# qualified namespace names with no excess colons and with the leading "::"
# omitted.
# (5) Trailing "::" implies a namespace tail {}, which interp reads as {{}}.
# Reject such names.
# (6) We could:
# (a) EITHER reject usable but non-compliant names (e.g. excess colons) in
# interpCreate, interpInit;
# (b) OR accept such names and then translate to a compliant name in every
# command.
# The problem with (b) is that the user will expect to use the name with the
# interp command and will find that it is not recognised.
# E.g "interpCreate ::foo" creates interpreter "foo", and the user's name
# "::foo" works with all the Safe Base commands, but "interp eval ::foo"
# fails.
# So we choose (a).
# (7) The command
# namespace upvar ::safe S$child state
# becomes
# namespace upvar ::safe [VarName $child] state
# ------------------------------------------------------------------------------
proc ::safe::RejectExcessColons {child} {
set stripped [regsub -all -- {:::*} $child ::]
if {[string range $stripped end-1 end] eq {::}} {
return -code error {interpreter name must not end in "::"}
}
if {$stripped ne $child} {
set msg {interpreter name has excess colons in namespace separators}
return -code error $msg
}
if {[string range $stripped 0 1] eq {::}} {
return -code error {interpreter name must not begin "::"}
}
return
}
proc ::safe::VarName {child} {
# return S$child
return S[string map {:: @N @ @A} $child]
}
proc ::safe::Setup {} {
####
#
# Setup the arguments parsing
#
####
# Share the descriptions
set temp [::tcl::OptKeyRegister {
{-accessPath -list {} "access path for the slave"}
{-noStatics "prevent loading of statically linked pkgs"}
{-statics true "loading of statically linked pkgs"}
{-nestedLoadOk "allow nested loading"}
{-nested false "nested loading"}
{-deleteHook -script {} "delete hook"}
}]
# create case (slave is optional)
::tcl::OptKeyRegister {
{?slave? -name {} "name of the slave (optional)"}
} ::safe::interpCreate
# adding the flags sub programs to the command program (relying on Opt's
# internal implementation details)
lappend ::tcl::OptDesc(::safe::interpCreate) $::tcl::OptDesc($temp)
# init and configure (slave is needed)
::tcl::OptKeyRegister {
{slave -name {} "name of the slave"}
} ::safe::interpIC
# adding the flags sub programs to the command program (relying on Opt's
# internal implementation details)
lappend ::tcl::OptDesc(::safe::interpIC) $::tcl::OptDesc($temp)
# temp not needed anymore
::tcl::OptKeyDelete $temp
####
#
# Default: No logging.
#
####
setLogCmd {}
# Log eventually.
# To enable error logging, set Log to {puts stderr} for instance,
# via setLogCmd.
return
}
namespace eval ::safe {
# internal variables
# Log command, set via 'setLogCmd'. Logging is disabled when empty.
variable Log {}
# The package maintains a state array per child interp under its
# control. The name of this array is S<interp-name>. This array is
# brought into scope where needed, using 'namespace upvar'. The S
# prefix is used to avoid that a child interp called "Log" smashes
# the "Log" variable.
#
# The array's elements are:
#
# access_path : List of paths accessible to the child.
# access_path,norm : Ditto, in normalized form.
# access_path,slave : Ditto, as the path tokens as seen by the child.
# access_path,map : dict ( token -> path )
# access_path,remap : dict ( path -> token )
# tm_path_slave : List of TM root directories, as tokens seen by the child.
# staticsok : Value of option -statics
# nestedok : Value of option -nested
# cleanupHook : Value of option -deleteHook
}
::safe::Setup
Mini Shell