From 17c226b070ef4ecdbcc5b4b5b0afe571f0f1a948 Mon Sep 17 00:00:00 2001
From: Bonsai <LetBonsaiBe@gmail.com>
Date: Sun, 28 Feb 2021 06:36:37 -0600
Subject: [PATCH] Module API for getting user name of a client (#8508)

Adding RM_GetClientUserNameById to get the ACL user name of a client connection.
---
 src/module.c      | 23 +++++++++++++++++++++++
 src/redismodule.h |  2 ++
 2 files changed, 25 insertions(+)

diff --git a/src/module.c b/src/module.c
index 9a37826fb..274210590 100644
--- a/src/module.c
+++ b/src/module.c
@@ -1837,6 +1837,28 @@ unsigned long long RM_GetClientId(RedisModuleCtx *ctx) {
     return ctx->client->id;
 }
 
+/* Return the ACL user name used by the client with the specified client ID.
+ * Client ID can be obtained with RM_GetClientId() API. If the client does not
+ * exist, NULL is returned and errno is set to ENOENT. If the client isn't 
+ * using an ACL user, NULL is returned and errno is set to ENOTSUP */
+RedisModuleString *RM_GetClientUserNameById(RedisModuleCtx *ctx, uint64_t id) {
+    client *client = lookupClientByID(id);
+    if (client == NULL) {
+        errno = ENOENT;
+        return NULL;
+    }
+    
+    if (client->user == NULL) {
+        errno = ENOTSUP;
+        return NULL;
+    }
+
+    sds name = sdsnew(client->user->name);
+    robj *str = createObject(OBJ_STRING, name);
+    autoMemoryAdd(ctx, REDISMODULE_AM_STRING, str);
+    return str;
+}
+
 /* This is an helper for RM_GetClientInfoById() and other functions: given
  * a client, it populates the client info structure with the appropriate
  * fields depending on the version provided. If the version is not valid
@@ -9157,6 +9179,7 @@ void moduleRegisterCoreAPI(void) {
     REGISTER_API(IsKeysPositionRequest);
     REGISTER_API(KeyAtPos);
     REGISTER_API(GetClientId);
+    REGISTER_API(GetClientUserNameById);
     REGISTER_API(GetContextFlags);
     REGISTER_API(AvoidReplicaTraffic);
     REGISTER_API(PoolAlloc);
diff --git a/src/redismodule.h b/src/redismodule.h
index 0c2801bea..ea271b82b 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -665,6 +665,7 @@ REDISMODULE_API long long (*RedisModule_StreamTrimByID)(RedisModuleKey *key, int
 REDISMODULE_API int (*RedisModule_IsKeysPositionRequest)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_KeyAtPos)(RedisModuleCtx *ctx, int pos) REDISMODULE_ATTR;
 REDISMODULE_API unsigned long long (*RedisModule_GetClientId)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
+REDISMODULE_API RedisModuleString * (*RedisModule_GetClientUserNameById)(RedisModuleCtx *ctx, uint64_t id) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_GetClientInfoById)(void *ci, uint64_t id) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_PublishMessage)(RedisModuleCtx *ctx, RedisModuleString *channel, RedisModuleString *message) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_GetContextFlags)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
@@ -936,6 +937,7 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(IsKeysPositionRequest);
     REDISMODULE_GET_API(KeyAtPos);
     REDISMODULE_GET_API(GetClientId);
+    REDISMODULE_GET_API(GetClientUserNameById);
     REDISMODULE_GET_API(GetContextFlags);
     REDISMODULE_GET_API(AvoidReplicaTraffic);
     REDISMODULE_GET_API(PoolAlloc);