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, 3 insertions, 0 deletions

diff --git a/src/server.h b/src/server.h
index ddc2808e4..0cc15f3e3 100644
--- a/src/server.h
+++ b/src/server.h
@@ -813,6 +813,8 @@ struct RedisModule {
     RedisModuleInfoFunc info_cb; /* Callback for module to add INFO fields. */
     RedisModuleDefragFunc defrag_cb;    /* Callback for global data defrag. */
     struct moduleLoadQueueEntry *loadmod; /* Module load arguments for config rewrite. */
+    int num_commands_with_acl_categories; /* Number of commands in this module included in acl categories */
+    int onload;     /* Flag to identify if the call is being made from Onload (0 or 1) */
 };
 typedef struct RedisModule RedisModule;
 
@@ -2950,6 +2952,7 @@ void addACLLogEntry(client *c, int reason, int context, int argpos, sds username
 sds getAclErrorMessage(int acl_res, user *user, struct redisCommand *cmd, sds errored_val, int verbose);
 void ACLUpdateDefaultUserPassword(sds password);
 sds genRedisInfoStringACLStats(sds info);
+void ACLRecomputeCommandBitsFromCommandRulesAllUsers();
 
 /* Sorted sets data type */