demo stuff, script contexts

git-svn-id: svn://svn.code.sf.net/p/actiongame/code/trunk/ac@1909 e016b1c5-ed68-44aa-a2f7-31cac88cffde

config/scontext.cfg

@@ -1,17 +1,22 @@
-// define script contexts to allow certain commands 
-// in (untrusted) map configuration files
+// define script security contexts to restrict commands to certain contexts
 // do NOT modify
 
-scriptcontext 1 alias
-scriptcontext 1 loadsky
-scriptcontext 1 mapmodelreset
-scriptcontext 1 mapmodel
-scriptcontext 1 texturereset
-scriptcontext 1 texture
-scriptcontext 1 fog
-scriptcontext 1 fogcolour
-scriptcontext 1 mapsound
-scriptcontext 1 watercolour
+// supported contexts
+alias context_core 0    // hardcoded scripts
+alias context_cfg 1     // known scripts
+alias context_prompt 2  // command propmpt
+alias context_mapcfg 3  // map configs, we don't trust them
+
+// set allowed commands for the map config context
+alias mapcfgidents [ alias loadsky mapmodelreset mapmodel texturereset texture fog fogcolour mapsound watercolour ]
+loop i (listlen $mapcfgidents) [
+    scriptcontext $context_mapcfg (at $mapcfgidents $i)
+]
+
+// isolate the map config context
+// this disables access from this context to identifiers located in other contexts
+// also it removes all aliases created in this context once the running context changes
+isolatecontext $context_mapcfg 
 
 // secure this configuration for the rest of the game
 sealcontexts 

source/src/clientgame.cpp

@@ -215,7 +215,7 @@ void movelocalplayer()
 	        moveplayer(player1, 10, false);
         }
     }
-    else if(!intermission)
+    else if(player1->state!=CS_SPECTATE && !intermission)
     {
         moveplayer(player1, 20, true);
         checkitems(player1);

source/src/command.cpp

@@ -4,9 +4,10 @@
 #include "pch.h"
 #include "cube.h"
 
+bool allowidentaccess(ident *id);
 char *exchangestr(char *o, char *n) { delete[] o; return newstring(n); }
 
-int execcontext = IEXC_CORE;
+int execcontext;
 
 hashtable<const char *, ident> *idents = NULL;        // contains ALL vars/commands/aliases
 
@@ -259,7 +260,7 @@ char *executeret(const char *p)                            // all evaluation hap
         }
         else 
         {
-            if(execcontext > id->context)
+            if(!allowidentaccess(id))
             {
                 conoutf("not allowed in this execution context: %s", id->name);
                 continue;
@@ -577,26 +578,36 @@ void identnames(vector<const char *> &names, bool builtinonly)
     enumerateht(*idents) if(!builtinonly || idents->enumc->data.type != ID_ALIAS) names.add(idents->enumc->key);
 }
 
-void changescriptcontext(int newcontext)
+vector<int> contextstack;
+bool contextsealed = false;
+bool contextisolated[IEXC_NUM] = { false };
+
+void pushscontext(int newcontext)
 {
-    if(newcontext < execcontext) // clean up aliases created in the old context
+    contextstack.add((execcontext = newcontext));
+}
+
+int popscontext()
+{
+    ASSERT(contextstack.length() > 0);
+    int old = contextstack.pop();
+    execcontext = contextstack.last();
+
+    if(execcontext < old && old >= IEXC_MAPCFG) // clean up aliases created in the old (map cfg) context
     {
         enumerateht(*idents)
         {
             ident *id = &idents->enumc->data;
-            if(id->type == ID_ALIAS && id->context > newcontext)
+            if(id->type == ID_ALIAS && id->context > execcontext)
             {
                 idents->remove(idents->enumc->key);
                 i--;
             }
         }
     }
-    execcontext = newcontext;
+    return execcontext;
 }
 
-
-bool contextsealed = false;
-
 void scriptcontext(char *context, char *idname)
 {
     if(contextsealed) return;
@@ -606,8 +617,22 @@ void scriptcontext(char *context, char *idname)
     if(c >= 0 && c < IEXC_NUM) id->context = c;
 }
 
+void isolatecontext(int context)
+{
+    if(context >= 0 && context < IEXC_NUM && !contextsealed) contextisolated[context] = true;
+}
+
 void sealcontexts() { contextsealed = true; }
 
+bool allowidentaccess(ident *id) // check if ident is allowed in current context
+{
+    ASSERT(execcontext >= 0 && execcontext < IEXC_NUM);
+    if(!id) return false;
+    if(!contextisolated[execcontext]) return true; // only check if context is isolated
+    return execcontext <= id->context; 
+}
+
 COMMAND(scriptcontext, ARG_2STR);
+COMMAND(isolatecontext, ARG_1INT);
 COMMAND(sealcontexts, ARG_NONE);
 

source/src/command.h

@@ -26,8 +26,10 @@ struct ident
     int narg;           // ID_VAR, ID_COMMAND
     char *action, *executing; // ID_ALIAS
     bool persist;
+    
     int context;
 
+
     ident() {}
 
     // ID_VAR
@@ -72,7 +74,7 @@ enum    // function signatures for script functions, see command.cpp
     ARG_VARI, ARG_VARIW
 };
 
-enum { IEXC_CORE = 0, IEXC_FOREIGN, IEXC_NUM }; // script execution context
+enum { IEXC_CORE = 0, IEXC_CFG, IEXC_PROMPT, IEXC_MAPCFG, IEXC_NUM }; // script execution context
 
 // nasty macros for registering script functions, abuses globals to avoid excessive infrastructure
 #define COMMANDN(name, fun, nargs) static bool __dummy_##fun = addcommand(#name, (void (*)())fun, nargs)

source/src/main.cpp

@@ -34,6 +34,7 @@ void quit()                     // normal exit
     if(resetcfg) deletecfg();
     else writecfg();
     cleanup(NULL);
+    popscontext();
 	exit(EXIT_SUCCESS);
 }
 
@@ -406,6 +407,8 @@ int main(int argc, char **argv)
     int uprate = 0, maxcl = DEFAULTCLIENTS, scthreshold = -5, port = 0;
     const char *sdesc = "", *ip = "", *master = NULL, *passwd = "", *maprot = NULL, *adminpwd = NULL, *srvmsg = NULL;
 
+    pushscontext(IEXC_CFG);
+
     #define initlog(s) puts("init: " s)
     
     initing = true;
@@ -622,6 +625,7 @@ int main(int argc, char **argv)
 		}
 #endif
     }
+
     quit();
     return EXIT_SUCCESS;
 }

source/src/protos.h

@@ -45,6 +45,10 @@ extern void changescriptcontext(int newcontext);
 extern void explodelist(const char *s, vector<char *> &elems);
 extern char *indexlist(const char *s, int pos);
 extern char *parseword(const char *&p);
+extern void pushscontext(int newcontext);
+extern int popscontext();
+extern int curscontext();
+extern int execcontext;
 
 // console
 extern void keypress(int code, bool isdown, int cooked);

source/src/rendermodel.cpp

@@ -66,7 +66,10 @@ void mapmodel(char *rad, char *h, char *zoff, char *snap, char *name)
     s_sprintf(mmi.name)("mapmodels/%s", name);
 }
 
-void mapmodelreset() { mapmodels.setsize(0); }
+void mapmodelreset() 
+{ 
+    if(execcontext==IEXC_MAPCFG) mapmodels.setsize(0);
+}
 
 mapmodelinfo &getmminfo(int i) { return mapmodels.inrange(i) ? mapmodels[i] : *(mapmodelinfo *)0; }
 

source/src/worldio.cpp

@@ -376,11 +376,13 @@ bool load_world(char *mname)        // still supports all map formats that have
     conoutf("read map %s (%d milliseconds)", cgzname, SDL_GetTicks()-lastmillis);
     conoutf("%s", hdr.maptitle);
     startmap(mname);
+
+    pushscontext(IEXC_MAPCFG); // untrusted altogether
     execfile("config/default_map_settings.cfg");
-    changescriptcontext(IEXC_FOREIGN);
     execfile(pcfname);
     execfile(mcfname);
-    changescriptcontext(IEXC_CORE);
+    popscontext();
+
 	c2skeepalive();
     loopi(256) if(texuse[i]) lookuptexture(i);
 	c2skeepalive();