Line data    Source code

       1              : /* -------------------------------------------------------------------------
       2              :  *
       3              :  * auth_delay.c
       4              :  *
       5              :  * Copyright (c) 2010-2026, 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            0 :         }
      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 : }