A reimplementation of blocking operation internals.

[redis.git] / src / scripting.c

diff --git a/src/scripting.c b/src/scripting.c
index 03938edd5d6979c39a98b69784695d8fb4e6a009..35b654f7739c490b806cbe5896d30766cbb98ad9 100644 (file)
--- a/src/scripting.c
+++ b/src/scripting.c
@@ -167,6 +167,13 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     redisClient *c = server.lua_client;
     sds reply;
 
     redisClient *c = server.lua_client;
     sds reply;
 

+    /* Require at least one argument */
+    if (argc == 0) {
+        luaPushError(lua,
+            "Please specify at least one argument for redis.call()");
+        return 1;
+    }
+

     /* Build the arguments vector */
     argv = zmalloc(sizeof(robj*)*argc);
     for (j = 0; j < argc; j++) {
     /* Build the arguments vector */
     argv = zmalloc(sizeof(robj*)*argc);
     for (j = 0; j < argc; j++) {


@@ -275,11 +282,10 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
      * reply as expected. */
     if ((cmd->flags & REDIS_CMD_SORT_FOR_SCRIPT) &&
         (reply[0] == '*' && reply[1] != '-')) {
      * reply as expected. */
     if ((cmd->flags & REDIS_CMD_SORT_FOR_SCRIPT) &&
         (reply[0] == '*' && reply[1] != '-')) {

-        /* Skip this step if command is SORT but output was already sorted */
-        if (cmd->proc != sortCommand || server.sort_dontsort)

             luaSortArray(lua);
     }
     sdsfree(reply);
             luaSortArray(lua);
     }
     sdsfree(reply);

+    c->reply_bytes = 0;

 
 cleanup:
     /* Clean up. Command code may have changed argv/argc so we use the
 
 cleanup:
     /* Clean up. Command code may have changed argv/argc so we use the


@@ -412,41 +418,46 @@ void luaLoadLibraries(lua_State *lua) {
 #endif
 }
 
 #endif
 }
 

-void scriptingProtectGlobals(lua_State *lua) {
-    char *s[26];
+/* Remove a functions that we don't want to expose to the Redis scripting
+ * environment. */
+void luaRemoveUnsupportedFunctions(lua_State *lua) {
+    lua_pushnil(lua);
+    lua_setglobal(lua,"loadfile");
+}
+
+/* This function installs metamethods in the global table _G that prevent
+ * the creation of globals accidentally.
+ *
+ * It should be the last to be called in the scripting engine initialization
+ * sequence, because it may interact with creation of globals. */
+void scriptingEnableGlobalsProtection(lua_State *lua) {
+    char *s[32];

     sds code = sdsempty();
     sds code = sdsempty();

-    int j;
+    int j = 0;

 
 

-    /* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html */
-    s[0]="local mt = getmetatable(_G)\n";
-    s[1]="if mt == nil then\n";
-    s[2]="  mt = {}\n";
-    s[3]="  setmetatable(_G, mt)\n";
-    s[4]="end\n";
-    s[5]="__STRICT = true\n";
-    s[6]="mt.__declared = {}\n";
-    s[7]="mt.__newindex = function (t, n, v)\n";
-    s[8]="  if __STRICT and not mt.__declared[n] and debug.getinfo(2) then\n";
-    s[9]="    local w = debug.getinfo(2, \"S\").what\n";
-    s[10]="    if w ~= \"main\" and w ~= \"C\" then\n";
-    s[11]="      error(\"assign to undeclared global var '\"..n..\"'\", 2)\n";
-    s[12]="    end\n";
-    s[13]="    mt.__declared[n] = true\n";
-    s[14]="  end\n";
-    s[15]="  rawset(t, n, v)\n";
-    s[16]="end\n";
-    s[17]="mt.__index = function (t, n)\n";
-    s[18]="  if debug.getinfo(2) and not mt.__declared[n] and debug.getinfo(2, \"S\").what ~= \"C\" then\n";
-    s[19]="    error(\"global var '\"..n..\"' is not declared\", 2)\n";
-    s[20]="  end\n";
-    s[21]="  return rawget(t, n)\n";
-    s[22]="end\n";
-    s[23]="function global(...)\n";
-    s[24]="   for _, v in ipairs{...} do mt.__declared[v] = true end\n";
-    s[25]="end\n";
-
-    for (j = 0; j < 26; j++) code = sdscatlen(code,s[j],strlen(s[j]));
-    luaL_loadbuffer(lua,code,sdslen(code),"strict_lua");
+    /* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html.
+     * Modified to be adapted to Redis. */
+    s[j++]="local mt = {}\n";
+    s[j++]="setmetatable(_G, mt)\n";
+    s[j++]="mt.__newindex = function (t, n, v)\n";
+    s[j++]="  if debug.getinfo(2) then\n";
+    s[j++]="    local w = debug.getinfo(2, \"S\").what\n";
+    s[j++]="    if w ~= \"main\" and w ~= \"C\" then\n";
+    s[j++]="      error(\"Script attempted to create global variable '\"..tostring(n)..\"'\", 2)\n";
+    s[j++]="    end\n";
+    s[j++]="  end\n";
+    s[j++]="  rawset(t, n, v)\n";
+    s[j++]="end\n";
+    s[j++]="mt.__index = function (t, n)\n";
+    s[j++]="  if debug.getinfo(2) and debug.getinfo(2, \"S\").what ~= \"C\" then\n";
+    s[j++]="    error(\"Script attempted to access unexisting global variable '\"..tostring(n)..\"'\", 2)\n";
+    s[j++]="  end\n";
+    s[j++]="  return rawget(t, n)\n";
+    s[j++]="end\n";
+    s[j++]=NULL;
+
+    for (j = 0; s[j] != NULL; j++) code = sdscatlen(code,s[j],strlen(s[j]));
+    luaL_loadbuffer(lua,code,sdslen(code),"@enable_strict_lua");

     lua_pcall(lua,0,0,0);
     sdsfree(code);
 }
     lua_pcall(lua,0,0,0);
     sdsfree(code);
 }


@@ -457,7 +468,9 @@ void scriptingProtectGlobals(lua_State *lua) {
  * See scriptingReset() for more information. */
 void scriptingInit(void) {
     lua_State *lua = lua_open();
  * See scriptingReset() for more information. */
 void scriptingInit(void) {
     lua_State *lua = lua_open();

+

     luaLoadLibraries(lua);
     luaLoadLibraries(lua);

+    luaRemoveUnsupportedFunctions(lua);

 
     /* Initialize a dictionary we use to map SHAs to scripts.
      * This is useful for replication, as we need to replicate EVALSHA
 
     /* Initialize a dictionary we use to map SHAs to scripts.
      * This is useful for replication, as we need to replicate EVALSHA


@@ -527,7 +540,7 @@ void scriptingInit(void) {
                                 "  if b == false then b = '' end\n"
                                 "  return a<b\n"
                                 "end\n";
                                 "  if b == false then b = '' end\n"
                                 "  return a<b\n"
                                 "end\n";

-        luaL_loadbuffer(lua,compare_func,strlen(compare_func),"cmp_func_def");
+        luaL_loadbuffer(lua,compare_func,strlen(compare_func),"@cmp_func_def");

         lua_pcall(lua,0,0,0);
     }
 
         lua_pcall(lua,0,0,0);
     }
 


@@ -543,7 +556,7 @@ void scriptingInit(void) {
     /* Lua beginners ofter don't use "local", this is likely to introduce
      * subtle bugs in their code. To prevent problems we protect accesses
      * to global variables. */
     /* Lua beginners ofter don't use "local", this is likely to introduce
      * subtle bugs in their code. To prevent problems we protect accesses
      * to global variables. */

-    scriptingProtectGlobals(lua);
+    scriptingEnableGlobalsProtection(lua);

 
     server.lua = lua;
 }
 
     server.lua = lua;
 }


@@ -678,7 +691,7 @@ int luaCreateFunction(redisClient *c, lua_State *lua, char *funcname, robj *body
     funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));
     funcdef = sdscatlen(funcdef," end",4);
 
     funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr));
     funcdef = sdscatlen(funcdef," end",4);
 

-    if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) {
+    if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"@user_script")) {

         addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
             lua_tostring(lua,-1));
         lua_pop(lua,1);
         addReplyErrorFormat(c,"Error compiling script (new function): %s\n",
             lua_tostring(lua,-1));
         lua_pop(lua,1);


@@ -709,6 +722,7 @@ void evalGenericCommand(redisClient *c, int evalsha) {
     lua_State *lua = server.lua;
     char funcname[43];
     long long numkeys;
     lua_State *lua = server.lua;
     char funcname[43];
     long long numkeys;

+    int delhook = 0;

 
     /* We want the same PRNG sequence at every call so that our PRNG is
      * not affected by external state. */
 
     /* We want the same PRNG sequence at every call so that our PRNG is
      * not affected by external state. */


@@ -779,19 +793,19 @@ void evalGenericCommand(redisClient *c, int evalsha) {
      * is running for too much time.
      * We set the hook only if the time limit is enabled as the hook will
      * make the Lua script execution slower. */
      * is running for too much time.
      * We set the hook only if the time limit is enabled as the hook will
      * make the Lua script execution slower. */

+    server.lua_caller = c;
+    server.lua_time_start = ustime()/1000;
+    server.lua_kill = 0;

     if (server.lua_time_limit > 0 && server.masterhost == NULL) {
         lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);
     if (server.lua_time_limit > 0 && server.masterhost == NULL) {
         lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000);

-    } else {
-        lua_sethook(lua,luaMaskCountHook,0,0);
+        delhook = 1;

     }
 
     /* At this point whatever this script was never seen before or if it was
      * already defined, we can call it. We have zero arguments and expect
      * a single return value. */
     }
 
     /* At this point whatever this script was never seen before or if it was
      * already defined, we can call it. We have zero arguments and expect
      * a single return value. */

-    server.lua_caller = c;
-    server.lua_time_start = ustime()/1000;
-    server.lua_kill = 0;

     if (lua_pcall(lua,0,1,0)) {
     if (lua_pcall(lua,0,1,0)) {

+        if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */

         if (server.lua_timedout) {
             server.lua_timedout = 0;
             /* Restore the readable handler that was unregistered when the
         if (server.lua_timedout) {
             server.lua_timedout = 0;
             /* Restore the readable handler that was unregistered when the


@@ -807,6 +821,7 @@ void evalGenericCommand(redisClient *c, int evalsha) {
         lua_gc(lua,LUA_GCCOLLECT,0);
         return;
     }
         lua_gc(lua,LUA_GCCOLLECT,0);
         return;
     }

+    if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */

     server.lua_timedout = 0;
     server.lua_caller = NULL;
     selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */
     server.lua_timedout = 0;
     server.lua_caller = NULL;
     selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */