bsdiskinfo/modules/lua/lua_bsdiskinfo.c

/*-
 * Copyright (c) 2026 Sergey Kiselev <root@dc365.ru>
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 */

#include <lua.h>
#include <lauxlib.h>
#include <stdlib.h>
#include <string.h>
#include "../../include/bsdiskinfo.h"

/* 
 * Compatibility layer for safe Lua library registration across versions.
 * Supports Lua 5.1, LuaJIT, and modern Lua 5.2+ environments seamlessly.
 */
#if LUA_VERSION_NUM == 501
#define luaL_newlib(L, l) (lua_newtable(L), luaL_register(L, NULL, l))
#endif

/*
 * Lua binding: bsdiskinfo.exists("ada0")
 * Returns boolean true if character device node exists, false otherwise.
 */
static int l_diskinfo_exists(lua_State *L) {
    const char *disk_name = luaL_checkstring(L, 1);
    lua_pushboolean(L, diskinfo_exists(disk_name));
    return 1;
}

/*
 * Lua binding: bsdiskinfo.get_properties("ada0")
 * Returns associative table containing raw hardware identification properties or nil.
 */
static int l_diskinfo_get_properties(lua_State *L) {
    const char *disk_name = luaL_checkstring(L, 1);
    struct disk_properties props;

    if (diskinfo_get_properties(disk_name, &props) != 0) {
        lua_pushnil(L);
        return 1;
    }

    lua_newtable(L);
    lua_pushstring(L, props.model);       lua_setfield(L, -2, "model");
    lua_pushstring(L, props.serial);      lua_setfield(L, -2, "serial");
    lua_pushstring(L, props.fw_version);  lua_setfield(L, -2, "fw_version");
    lua_pushstring(L, props.wwn);         lua_setfield(L, -2, "wwn");
    lua_pushstring(L, props.type_str);    lua_setfield(L, -2, "type");
    
    /* Export raw media capacities as numbers for granular high-level math formatting */
    lua_pushnumber(L, (lua_Number)props.mediasize);
    lua_setfield(L, -2, "mediasize");

    lua_pushinteger(L, props.logical_sector_size);
    lua_setfield(L, -2, "logical_sector_size");

    lua_pushinteger(L, props.physical_sector_size);
    lua_setfield(L, -2, "physical_sector_size");

    if (props.rotation_rate >= 0) {
        lua_pushinteger(L, props.rotation_rate);
        lua_setfield(L, -2, "rotation_rate");
    }

    if (props.smart_supported >= 0) {
        lua_pushboolean(L, props.smart_supported == 1);
        lua_setfield(L, -2, "smart_supported");
        
        lua_pushboolean(L, props.smart_enabled == 1);
        lua_setfield(L, -2, "smart_enabled");
    }

    return 1;
}

/*
 * Lua binding: bsdiskinfo.get_mounts("ada0")
 * Returns a sequentially indexed array table containing active partitions and mount targets.
 */
static int l_diskinfo_get_mounts(lua_State *L) {
    const char *disk_name = luaL_checkstring(L, 1);
    struct disk_mount mounts[MAX_MOUNTS];

    int count = diskinfo_get_mounts(disk_name, mounts, MAX_MOUNTS);
    if (count < 0) {
        lua_pushnil(L);
        return 1;
    }

    lua_newtable(L); /* Root array table */
    for (int i = 0; i < count; i++) {
        lua_newtable(L); /* Individual record sub-table */
        
        lua_pushstring(L, mounts[i].device); lua_setfield(L, -2, "device");
        lua_pushstring(L, mounts[i].path);   lua_setfield(L, -2, "path");
        lua_pushstring(L, mounts[i].fstype); lua_setfield(L, -2, "fstype");

        lua_rawseti(L, -2, i + 1); /* Inject into sequential array slot */
    }

    return 1;
}

/*
 * Lua binding: bsdiskinfo.get_smart_counters("ada0")
 * Returns a sequentially indexed array table storing extracted raw S.M.A.R.T. structural entries.
 */
static int l_diskinfo_get_smart_counters(lua_State *L) {
    const char *disk_name = luaL_checkstring(L, 1);
    struct smart_counter counters[30];

    int count = diskinfo_get_smart_counters(disk_name, counters, 30);
    if (count < 0) {
        lua_pushnil(L);
        return 1;
    }

    lua_newtable(L); /* Root array table */
    for (int i = 0; i < count; i++) {
        lua_newtable(L); /* Individual attribute sub-table */

        lua_pushinteger(L, counters[i].id);
        lua_setfield(L, -2, "id");

        lua_pushinteger(L, counters[i].value);
        lua_setfield(L, -2, "value");

        lua_pushinteger(L, counters[i].worst);
        lua_setfield(L, -2, "worst");

        /* Export raw values as Lua numbers to handle massive 48-bit storage tracking values safely */
        lua_pushnumber(L, (lua_Number)counters[i].raw_val);
        lua_setfield(L, -2, "raw_val");

        lua_rawseti(L, -2, i + 1);
    }

    return 1;
}

/*
 * Exported library methods routing dictionary map block compliant with Lua module initialization standards
 */
static const struct luaL_Reg bsdiskinfo_methods[] = {
    { "exists",             l_diskinfo_exists },
    { "get_properties",     l_diskinfo_get_properties },
    { "get_mounts",         l_diskinfo_get_mounts },
    { "get_smart_counters", l_diskinfo_get_smart_counters },
    { NULL,                 NULL }
};

/*
 * Official library runtime shared object entry-point.
 * Executed automatically by kernel dynamic loaders when require("bsdiskinfo") fires inside user space scripts.
 */
int luaopen_bsdiskinfo(lua_State *L) {
#if LUA_VERSION_NUM >= 502
    luaL_newlib(L, bsdiskinfo_methods);
#else
    lua_newtable(L);
    luaL_register(L, NULL, bsdiskinfo_methods);
#endif
    return 1;
}