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_EXT(
      20             :                     .name = "auth_delay",
      21             :                     .version = PG_VERSION
      22             : );
      23             : 
      24             : /* GUC Variables */
      25             : static int  auth_delay_milliseconds = 0;
      26             : 
      27             : /* Original Hook */
      28             : static ClientAuthentication_hook_type original_client_auth_hook = NULL;
      29             : 
      30             : /*
      31             :  * Check authentication
      32             :  */
      33             : static void
      34           0 : auth_delay_checks(Port *port, int status)
      35             : {
      36             :     /*
      37             :      * Any other plugins which use ClientAuthentication_hook.
      38             :      */
      39           0 :     if (original_client_auth_hook)
      40           0 :         original_client_auth_hook(port, status);
      41             : 
      42             :     /*
      43             :      * Inject a short delay if authentication failed.
      44             :      */
      45           0 :     if (status != STATUS_OK)
      46             :     {
      47           0 :         pg_usleep(1000L * auth_delay_milliseconds);
      48             :     }
      49           0 : }
      50             : 
      51             : /*
      52             :  * Module Load Callback
      53             :  */
      54             : void
      55           0 : _PG_init(void)
      56             : {
      57             :     /* Define custom GUC variables */
      58           0 :     DefineCustomIntVariable("auth_delay.milliseconds",
      59             :                             "Milliseconds to delay before reporting authentication failure",
      60             :                             NULL,
      61             :                             &auth_delay_milliseconds,
      62             :                             0,
      63             :                             0, INT_MAX / 1000,
      64             :                             PGC_SIGHUP,
      65             :                             GUC_UNIT_MS,
      66             :                             NULL,
      67             :                             NULL,
      68             :                             NULL);
      69             : 
      70           0 :     MarkGUCPrefixReserved("auth_delay");
      71             : 
      72             :     /* Install Hooks */
      73           0 :     original_client_auth_hook = ClientAuthentication_hook;
      74           0 :     ClientAuthentication_hook = auth_delay_checks;
      75           0 : }