- disable print

- add a log facility to lua (so far just prints to stderr)
- add settings to disable lua even if installed, to load or not to load user scripts when superuser
- create a default /usr/local/share/ethereal/init.lua that blocks all the io/system calls when running as superuser



svn path=/trunk/; revision=17290

6 files changed, 306 insertions, 35 deletions

diff --git a/Makefile.am b/Makefile.am
index 921a778d40..33d6f693e2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -682,7 +682,10 @@ EXTRA_DIST = \
 	text2pcap-scanner.l	\
 	text2pcap.c		\
 	text2pcap.h		\
-	wka.tmpl
+	wka.tmpl \
+	template-init.lua \
+	make-init-lua.pl \
+	init.lua
 
 if SETUID_INSTALL
 install-exec-hook:
@@ -841,3 +844,7 @@ test-splint: $(ethereal_SOURCES)
 		-I./tools/lemon \
 		-I./wiretap	\
 		$(ethereal_SOURCES)
+
+init.lua: template-init.lua make-init-lua.pl epan/ftypes/ftypes.h wiretap/wtap.h
+	$(PERL) make-init-lua.pl template-init.lua > init.lua
+
diff --git a/Makefile.nmake b/Makefile.nmake
index 1268f2b1dd..ecad5375c1 100644
--- a/Makefile.nmake
+++ b/Makefile.nmake
@@ -672,4 +672,8 @@ clean-deps:
 	$(MAKE) /$(MAKEFLAGS) -f Makefile.nmake clean-deps
 	cd ..
 
+init.lua: template-init.lua make-init-lua.pl epan/ftypes/ftypes.h wiretap/wtap.h
+	$(PERL) make-init-lua.pl template-init.lua > init.lua
+
+
 
diff --git a/make-init-lua.pl b/make-init-lua.pl
new file mode 100644
index 0000000000..aa9e5c49a1
--- /dev/null
+++ b/make-init-lua.pl
@@ -0,0 +1,94 @@
+#!/usr/bin/perl
+# create the init.lua file based on a template (stdin) 
+#
+# $Id: $
+#
+# Ethereal - Network traffic analyzer
+# By Gerald Combs <gerald@ethereal.com>
+# Copyright 2004 Gerald Combs
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+use strict;
+
+my $wtap_encaps_table = '';
+my $ft_types_table = '';
+
+
+my %replacements = %{{
+    WTAP_ENCAPS => \$wtap_encaps_table,
+    FT_TYPES => \$ft_types_table,
+}};
+
+
+#
+# load template
+#
+my $template = '';
+$template .= $_ while(<>);
+
+
+#
+# make wiretap encapusulation table 
+#
+
+$wtap_encaps_table = "-- Wiretap encapsulations\nwtap = {\n";
+
+open WTAP_H, "< wiretap/wtap.h";
+
+while(<WTAP_H>) {
+    if ( /^#define WTAP_ENCAP_([A-Z0-9_]+)\s+(\d+)/ ) {
+        $wtap_encaps_table .= "\t[\"$1\"] = $2,\n";
+    }
+}
+
+$wtap_encaps_table =~ s/,\n$/\n}\n/msi;
+
+#
+# enum fttype
+#
+
+$ft_types_table = " -- Field Types\nftypes = {\n";
+
+my $ftype_num = 0;
+
+open FTYPES_H, "< ./epan/ftypes/ftypes.h";
+while(<FTYPES_H>) {
+    if ( /^\s+(FT_[A-Z0-9a-z_]+)\s*,/ ) {
+        $ft_types_table .= "\t[\"$1\"] = $ftype_num,\n";
+        $ftype_num++;
+    }
+}
+close FTYPES_H;
+
+$ft_types_table =~ s/,\n$/\n}\n/msi;
+
+
+
+#
+# 
+#
+
+
+#
+# replace macros
+#
+
+for my $key (keys %replacements) {
+    $template =~ s/%$key%/${$replacements{$key}}/msig;
+}
+
+
+print $template;
diff --git a/plugins/lua/packet-lua.c b/plugins/lua/packet-lua.c
index 7ff4bee583..875cff4aa3 100644
--- a/plugins/lua/packet-lua.c
+++ b/plugins/lua/packet-lua.c
@@ -92,6 +92,45 @@ static int lua_not_register_menu(lua_State* L) {
     return 0;    
 }
 
+static int lua_not_print(lua_State* L) {
+    luaL_error(L,"do not use print use either a TextWindow or critical(),\n"
+               "warn(), message(), info() or debug()");
+    return 0;        
+}
+
+int lua_log(lua_State* L, GLogLevelFlags log_level) {
+    GString* str = g_string_new("");
+    int n = lua_gettop(L);  /* number of arguments */
+    int i;
+    
+    lua_getglobal(L, "tostring");
+    for (i=1; i<=n; i++) {
+        const char *s;
+        lua_pushvalue(L, -1);  /* function to be called */
+        lua_pushvalue(L, i);   /* value to print */
+        lua_call(L, 1, 1);
+        s = lua_tostring(L, -1);  /* get result */
+        if (s == NULL)
+            return luaL_error(L, "`tostring' must return a string to `print'");
+        
+        if (i>1) g_string_append(str,"\t");
+        g_string_append(str,s);
+        
+        lua_pop(L, 1);  /* pop result */
+    }
+    
+    g_log(LOG_DOMAIN_LUA, log_level, "%s\n", str->str);
+    g_string_free(str,TRUE);
+    
+    return 0;
+}
+
+int lua_critical( lua_State* L ) { lua_log(L,G_LOG_LEVEL_CRITICAL); return 0; }
+int lua_warn( lua_State* L ) { lua_log(L,G_LOG_LEVEL_WARNING); return 0; }
+int lua_message( lua_State* L ) { lua_log(L,G_LOG_LEVEL_MESSAGE); return 0; }
+int lua_info( lua_State* L ) { lua_log(L,G_LOG_LEVEL_INFO); return 0; }
+int lua_debug( lua_State* L ) { lua_log(L,G_LOG_LEVEL_DEBUG); return 0; }
+
 
 void dissect_lua(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree) {
     lua_pinfo = pinfo;
@@ -243,44 +282,37 @@ void lua_load_script(const gchar* filename) {
     
 }
 
+static void basic_logger(const gchar *log_domain _U_,
+                          GLogLevelFlags log_level _U_,
+                          const gchar *message,
+                          gpointer user_data _U_) {
+    fputs(message,stderr);
+}
+
 void register_lua(void) {
     const gchar* filename;
-    GPtrArray* filenames = g_ptr_array_new();
-    guint i;
-    
-    filename = get_datafile_path("init.lua");
-    
-    if (( file_exists(filename))) {
-        g_ptr_array_add(filenames,(void*)filename);
-    }
-    
-
-    if (! started_with_special_privs() ) {
-        filename = get_persconffile_path("init.lua", FALSE);
-        
-        if (( file_exists(filename))) {
-            g_ptr_array_add(filenames,(void*)filename);
-        }
-        
-        while((filename = ex_opt_get_next("lua_script"))) {
-            g_ptr_array_add(filenames,(void*)filename);
-        }
-    }
+    const funnel_ops_t* ops = funnel_get_funnel_ops();
+    gboolean run_anyway = FALSE;
     
-    if (! filenames->len) {
-        g_ptr_array_free(filenames,TRUE);
-        return;
-    }
+    /* set up the logger */
+    g_log_set_handler(LOG_DOMAIN_LUA, G_LOG_LEVEL_CRITICAL|
+                      G_LOG_LEVEL_WARNING|
+                      G_LOG_LEVEL_MESSAGE|
+                      G_LOG_LEVEL_INFO|
+                      G_LOG_LEVEL_DEBUG,
+                      ops ? ops->logger : basic_logger, NULL);
     
-    register_init_routine(init_lua);    
+    /* initialize the lua machine */
     
     L = lua_open();
     
+    /* load lua's standard library */ 
     luaopen_base(L);
     luaopen_table(L);
     luaopen_io(L);
     luaopen_string(L);
-
+    
+    /* load ethereal's API */
     ProtoField_register(L);
     ProtoFieldArray_register(L);
     SubTree_register(L);
@@ -299,7 +331,35 @@ void register_lua(void) {
     Tap_register(L);
     Address_register(L);
     TextWindow_register(L);
-
+    
+    /* print has been changed to yield an error if used */
+    lua_pushstring(L, "print");
+    lua_pushcfunction(L, lua_not_print);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    /* logger functions */
+    lua_pushstring(L, "critical");
+    lua_pushcfunction(L, lua_critical);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    lua_pushstring(L, "warn");
+    lua_pushcfunction(L, lua_warn);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    lua_pushstring(L, "message");
+    lua_pushcfunction(L, lua_message);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    lua_pushstring(L, "info");
+    lua_pushcfunction(L, lua_info);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    lua_pushstring(L, "debug");
+    lua_pushcfunction(L, lua_debug);
+    lua_settable(L, LUA_GLOBALSINDEX);
+    
+    
+    /* functions not registered by any other module */
     lua_pushstring(L, "format_date");
     lua_pushcfunction(L, lua_format_date);
     lua_settable(L, LUA_GLOBALSINDEX);
@@ -323,26 +383,73 @@ void register_lua(void) {
     lua_pushstring(L, "dialog");
     lua_pushcfunction(L, lua_new_dialog);
     lua_settable(L, LUA_GLOBALSINDEX);
-
+    
+    /* the init_routines table (accessible by the user) */
     lua_pushstring(L, LUA_INIT_ROUTINES);
     lua_newtable (L);
     lua_settable(L, LUA_GLOBALSINDEX);
     
+    /* the dissectors table goes in the registry (not accessible) */
     lua_newtable (L);
     lua_dissectors_table_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+    /* set running_superuser variable to it's propper value */
+    lua_pushstring(L,"running_superuser");
+    lua_pushboolean(L,started_with_special_privs());
+    lua_settable(L, LUA_GLOBALSINDEX);    
+
+    /* load system's init.lua */
+    filename = get_datafile_path("init.lua");
     
-    for (i=0 ; i < filenames->len ; i++) {
-        filename = g_ptr_array_index(filenames,i);
+    if (( file_exists(filename))) {
         lua_load_script(filename);
     }
     
-    g_ptr_array_free(filenames,TRUE);
+    /* check if lua is to be disabled */
+    lua_pushstring(L,"lua_disabled");
+    lua_gettable(L, LUA_GLOBALSINDEX);
     
-    /* after the body it is too late to register a menu */
+    if (lua_isboolean(L,-1) && lua_toboolean(L,-1)) {
+        /* disable lua */
+        lua_close(L);
+        L = NULL;
+        return;
+    }
+    
+    /* check whether we should run other scripts even if running superuser */
+    lua_pushstring(L,"run_user_scripts_when_superuser");
+    lua_gettable(L, LUA_GLOBALSINDEX);
+    
+    if (lua_isboolean(L,-1) && lua_toboolean(L,-1)) {
+        run_anyway = TRUE;
+    }
+
+
+    /* if we are indeed superuser run user scripts only if told to do so */
+    if ( (!started_with_special_privs()) || run_anyway ) {
+        filename = get_persconffile_path("init.lua", FALSE);
+        
+        if (( file_exists(filename))) {
+            lua_load_script(filename);
+        }
+        
+        while((filename = ex_opt_get_next("lua_script"))) {
+            lua_load_script(filename);
+        }
+    }
+    
+    /* at this point we're set up so register the init routine */
+    register_init_routine(init_lua);    
+    
+    /*
+     * after this point it is too late to register a menu
+     * disable the function to avoid weirdness
+     */
     lua_pushstring(L, "register_menu");
     lua_pushcfunction(L, lua_not_register_menu);
     lua_settable(L, LUA_GLOBALSINDEX);
     
+    /* set up some essential globals */
     lua_pinfo = NULL;
     lua_tree = NULL;
     lua_tvb = NULL;
diff --git a/plugins/lua/packet-lua.h b/plugins/lua/packet-lua.h
index 954ab41587..4b21b65de6 100644
--- a/plugins/lua/packet-lua.h
+++ b/plugins/lua/packet-lua.h
@@ -52,6 +52,7 @@
 #define LUA_DISSECTORS_TABLE "dissectors"
 #define LUA_INIT_ROUTINES "init_routines"
 #define LUA_HANDOFF_ROUTINES "handoff_routines"
+#define LOG_DOMAIN_LUA "Lua"
 
 struct _eth_tvbrange {
     tvbuff_t* tvb;
@@ -193,7 +194,7 @@ C* push##C(lua_State* L, C v) { \
 gboolean is##C(lua_State* L,int i) { \
         return (gboolean)(lua_isuserdata(L,i) && luaL_checkudata(L,3,CN)); \
 } \
-extern C shift##C(lua_State* L,int i) { \
+C shift##C(lua_State* L,int i) { \
     C* p; \
     if ((p = (C*)luaL_checkudata(L, i, CN))) {\
         lua_remove(L,i); \
diff --git a/template-init.lua b/template-init.lua
new file mode 100644
index 0000000000..85f316aac3
--- /dev/null
+++ b/template-init.lua
@@ -0,0 +1,58 @@
+-- init.lua
+--
+-- initilaize ethereal's lua
+--
+--  This file is going to be executed before any other lua script.
+--  It can be used to load libraries, disable functions and more.
+--
+-- $Id: $
+-- 
+-- Ethereal - Network traffic analyzer
+-- By Gerald Combs <gerald@ethereal.com>
+-- Copyright 1998 Gerald Combs
+--
+-- This program is free software; you can redistribute it and/or
+-- modify it under the terms of the GNU General Public License
+-- as published by the Free Software Foundation; either version 2
+-- of the License, or (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program; if not, write to the Free Software
+-- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+
+-- If lua is to be disabled even if it was installed uncomment the following
+-- line.
+-- disable_lua = true; do return end;
+
+
+-- If set and we are running with special privileges this setting
+-- tells whether scripts other than this one are to be run.
+run_user_scripts_when_superuser = false
+
+-- disable potentialy harmful lua functions when running superuser
+if running_superuser then
+    dofile = function() error("dofile has been disabled") end
+    loadfile = function() error("loadfile has been disabled") end
+    loadlib = function() error("loadlib has been disabled") end
+    require = function() error("require has been disabled") end
+    os = {}
+    io = {}
+    file = {}
+end
+
+-- to avoid output to stdout which can caause problems lua's print ()
+-- has been suppresed so that it yields an error.
+-- have print() call info() instead.
+print = info
+
+-- %WTAP_ENCAPS%
+
+-- %FT_TYPES%
+
+