Module commands to have ACL categories. (#11708)

This allows modules to register commands to existing ACL categories and blocks the creation of [sub]commands, datatypes and registering the configs outside of the OnLoad function.

For allowing modules to register commands to existing ACL categories,
This PR implements a new API int RM_SetCommandACLCategories() which takes a pointer to a RedisModuleCommand and a C string aclflags containing the set of space separated ACL categories.
Example, 'write slow' marks the command as part of the write and slow ACL categories.

The C string aclflags is tokenized by implementing a helper function categoryFlagsFromString(). Theses tokens are matched and the corresponding ACL categories flags are set by a helper function matchAclCategoriesFlags. The helper function categoryFlagsFromString() returns the corresponding categories_flags or returns -1 if some token not processed correctly.

If the module contains commands which are registered to existing ACL categories, the number of [sub]commands are tracked by num_commands_with_acl_categories in struct RedisModule. Further, the allowed command bit-map of the existing users are recomputed from the command_rules list, by implementing a function called ACLRecomputeCommandBitsFromCommandRulesAllUsers() for the existing users to have access to the module commands on runtime.

## Breaking change
This change requires that registering commands and subcommands only occur during a modules "OnLoad" function, in order to allow efficient recompilation of ACL bits. We also chose to block registering configs and types, since we believe it's only valid for those to be created during onLoad. We check for this onload flag in struct RedisModule to check if the call is made from the OnLoad function.

Co-authored-by: Madelyn Olson <madelyneolson@gmail.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/modules/datatype.c b/tests/modules/datatype.c
index 45a356e52..408d1a526 100644
--- a/tests/modules/datatype.c
+++ b/tests/modules/datatype.c
@@ -234,6 +234,31 @@ static int datatype_is_in_slow_loading(RedisModuleCtx *ctx, RedisModuleString **
     return REDISMODULE_OK;
 }
 
+int createDataTypeBlockCheck(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+    static RedisModuleType *datatype_outside_onload = NULL;
+
+    RedisModuleTypeMethods datatype_methods = {
+        .version = REDISMODULE_TYPE_METHOD_VERSION,
+        .rdb_load = datatype_load,
+        .rdb_save = datatype_save,
+        .free = datatype_free,
+        .copy = datatype_copy
+    };
+
+    datatype_outside_onload = RedisModule_CreateDataType(ctx, "test_dt_outside_onload", 1, &datatype_methods);
+
+    /* This validates that it's not possible to create datatype outside OnLoad,
+     * thus returns an error if it succeeds. */
+    if (datatype_outside_onload == NULL) {
+        RedisModule_ReplyWithSimpleString(ctx, "OK");
+    } else {
+        RedisModule_ReplyWithError(ctx, "UNEXPECTEDOK");
+    }
+    return REDISMODULE_OK;
+}
+
 int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
     REDISMODULE_NOT_USED(argv);
     REDISMODULE_NOT_USED(argc);
@@ -241,6 +266,10 @@ int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
     if (RedisModule_Init(ctx,"datatype",DATATYPE_ENC_VER,REDISMODULE_APIVER_1) == REDISMODULE_ERR)
         return REDISMODULE_ERR;
 
+    /* Creates a command which creates a datatype outside OnLoad() function. */
+    if (RedisModule_CreateCommand(ctx,"block.create.datatype.outside.onload", createDataTypeBlockCheck, "write", 0, 0, 0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
     RedisModule_SetModuleOptions(ctx, REDISMODULE_OPTIONS_HANDLE_IO_ERRORS);
 
     RedisModuleTypeMethods datatype_methods = {