Line data    Source code

       1             : /* -------------------------------------------------------------------------
       2             :  *
       3             :  * auth_delay.c
       4             :  *
       5             :  * Copyright (c) 2010-2025, PostgreSQL Global Development Group
       6             :  *
       7             :  * IDENTIFICATION
       8             :  *      contrib/auth_delay/auth_delay.c
       9             :  *
      10             :  * -------------------------------------------------------------------------
      11             :  */
      12             : #include "postgres.h"
      13             : 
      14             : #include <limits.h>
      15             : 
      16             : #include "libpq/auth.h"
      17             : #include "utils/guc.h"
      18             : 
      19           0 : PG_MODULE_MAGIC;
      20             : 
      21             : /* GUC Variables */
      22             : static int  auth_delay_milliseconds = 0;
      23             : 
      24             : /* Original Hook */
      25             : static ClientAuthentication_hook_type original_client_auth_hook = NULL;
      26             : 
      27             : /*
      28             :  * Check authentication
      29             :  */
      30             : static void
      31           0 : auth_delay_checks(Port *port, int status)
      32             : {
      33             :     /*
      34             :      * Any other plugins which use ClientAuthentication_hook.
      35             :      */
      36           0 :     if (original_client_auth_hook)
      37           0 :         original_client_auth_hook(port, status);
      38             : 
      39             :     /*
      40             :      * Inject a short delay if authentication failed.
      41             :      */
      42           0 :     if (status != STATUS_OK)
      43             :     {
      44           0 :         pg_usleep(1000L * auth_delay_milliseconds);
      45             :     }
      46           0 : }
      47             : 
      48             : /*
      49             :  * Module Load Callback
      50             :  */
      51             : void
      52           0 : _PG_init(void)
      53             : {
      54             :     /* Define custom GUC variables */
      55           0 :     DefineCustomIntVariable("auth_delay.milliseconds",
      56             :                             "Milliseconds to delay before reporting authentication failure",
      57             :                             NULL,
      58             :                             &auth_delay_milliseconds,
      59             :                             0,
      60             :                             0, INT_MAX / 1000,
      61             :                             PGC_SIGHUP,
      62             :                             GUC_UNIT_MS,
      63             :                             NULL,
      64             :                             NULL,
      65             :                             NULL);
      66             : 
      67           0 :     MarkGUCPrefixReserved("auth_delay");
      68             : 
      69             :     /* Install Hooks */
      70           0 :     original_client_auth_hook = ClientAuthentication_hook;
      71           0 :     ClientAuthentication_hook = auth_delay_checks;
      72           0 : }