Added wrapper for accountListAllUsers

nx/include/switch/services/acc.h

@@ -39,10 +39,12 @@ Service* accountGetService(void);
 Result accountGetUserCount(s32* user_count);
 
 /**
- * @brief Get a list of all user IDs
- * @param userIDs Pointer to array of user IDs, array must be exactly ACC_USER_LIST_SIZE
+ * @brief Get a list of all user IDs. The returned list will never be larger than ACC_USER_LIST_SIZE
+ * @param userIDs Pointer to array of user IDs
+ * @param max_userIDs Maximum number of user IDs to return
+ * @param actual_total The actual total number of user IDs found
  */
-Result accountListAllUsers(u128* userIDs);
+Result accountListAllUsers(u128* userIDs, size_t max_userIDs, size_t *actual_total);
 
 /// Get the userID for the currently active user. The output userID is only valid when the output account_selected==1, otherwise no user is currently selected.
 /// An user is only selected when the user-account selection applet was used to select an user at least once before.

nx/source/services/acc.c

@@ -1,4 +1,5 @@
 #include <string.h>
+#include <malloc.h>
 
 #include "types.h"
 #include "arm/atomics.h"
@@ -70,7 +71,7 @@ Result accountGetUserCount(s32* user_count)
     return rc;
 }
 
-Result accountListAllUsers(u128* userIDs)
+static Result _accountListAllUsers(u128* userIDs)
 {
     IpcCommand c;
     ipcInitialize(&c);
@@ -108,6 +109,38 @@ Result accountListAllUsers(u128* userIDs)
     return rc;
 }
 
+Result accountListAllUsers(u128* userIDs, size_t max_userIDs, size_t *actual_total)
+{
+    Result rc=0;
+
+    u128 *temp_userIDs;
+	temp_userIDs = malloc(sizeof(u128) * ACC_USER_LIST_SIZE);
+
+    rc = _accountListAllUsers(temp_userIDs);
+
+    if (R_SUCCEEDED(rc)) {
+        size_t total_userIDs = 0;
+
+        for (int i = 0; i < ACC_USER_LIST_SIZE; i++) {
+            if (temp_userIDs[i]) {
+                total_userIDs++;
+            }
+        }
+
+        if (max_userIDs > total_userIDs) {
+            max_userIDs = total_userIDs;
+        }
+
+        for (int i = 0; i < max_userIDs; i++) {
+            userIDs[i] = temp_userIDs[i];
+        }
+
+        *actual_total = total_userIDs;
+    }
+
+    return rc;
+}
+
 Result accountGetActiveUser(u128 *userID, bool *account_selected)
 {
     IpcCommand c;