/*      $NetBSD: ddbping.c,v 1.3 2023/02/01 10:22:20 uwe Exp $ */
/*
* Copyright (c) 2020 Valery Ushakov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*
* Example of a kernel module that registers DDB commands.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ddbping.c,v 1.3 2023/02/01 10:22:20 uwe Exp $");

#include <sys/param.h>
#include <sys/module.h>

#include <ddb/ddb.h>

/* XXX: db_command.h should provide something like this */
typedef void db_cmdfn_t(db_expr_t, bool, db_expr_t, const char *);


static db_cmdfn_t db_ping;
static db_cmdfn_t db_show_ping;


static const struct db_command db_ping_base_tbl[] = {
       { DDB_ADD_CMD("ping", db_ping, 0,
                     "Example command",
                     NULL, NULL) },
       { DDB_END_CMD },
};

static const struct db_command db_ping_show_tbl[] = {
       { DDB_ADD_CMD("ping", db_show_ping, 0,
                     "Example command stats",
                     NULL, NULL) },
       { DDB_END_CMD },
};


static unsigned int ping_count;
static unsigned int ping_count_modif;
static unsigned int ping_count_addr;
static unsigned int ping_count_count;


static void
db_ping(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
{
       db_printf("pong");
       ++ping_count;

       if (modif != NULL && *modif != '\0') {
               db_printf("/%s", modif);
               ++ping_count_modif;
       }

       if (have_addr) {
               db_printf(" 0x%zx", (size_t)addr);
               ++ping_count_addr;
       }

       if (count > 0) {
               db_printf(", 0t%zu", (size_t)count);
               ++ping_count_count;
       }

       db_printf("\n");
}


static void
db_show_ping(db_expr_t addr, bool have_addr, db_expr_t count, const char *modif)
{
       db_printf("total\t\t%u\n", ping_count);
       db_printf("with modifiers\t%u\n", ping_count_modif);
       db_printf("with address\t%u\n", ping_count_addr);
       db_printf("with count\t%u\n", ping_count_count);
}


MODULE(MODULE_CLASS_MISC, ddbping, NULL);

static int
ddbping_modcmd(modcmd_t cmd, void *arg __unused)
{
       switch (cmd) {
       case MODULE_CMD_INIT:
               db_register_tbl(DDB_BASE_CMD, db_ping_base_tbl);
               db_register_tbl(DDB_SHOW_CMD, db_ping_show_tbl);
               break;

       case MODULE_CMD_FINI:
               db_unregister_tbl(DDB_BASE_CMD, db_ping_base_tbl);
               db_unregister_tbl(DDB_SHOW_CMD, db_ping_show_tbl);
               break;

       case MODULE_CMD_STAT:   /* FALLTHROUGH */
       default:
               return ENOTTY;
       }

       return 0;
}