/*
** Zabbix
** Copyright (C) 2001-2021 Zabbix SIA
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/

#include "common.h"
#include "sysinfo.h"
#include "zbxjson.h"
#include "log.h"
#include "zbxalgo.h"
#include "inodes.h"

static int	get_fs_size_stat(const char *fs, zbx_uint64_t *total, zbx_uint64_t *free,
		zbx_uint64_t *used, double *pfree, double *pused, char **error)
{
#ifdef HAVE_SYS_STATVFS_H
#	define ZBX_STATFS	statvfs
#	define ZBX_BSIZE	f_frsize
#else
#	define ZBX_STATFS	statfs
#	define ZBX_BSIZE	f_bsize
#endif
	struct ZBX_STATFS	s;

	if (0 != ZBX_STATFS(fs, &s))
	{
		*error = zbx_dsprintf(NULL, "Cannot obtain filesystem information: %s", zbx_strerror(errno));
		zabbix_log(LOG_LEVEL_DEBUG,"%s failed with error: %s",__func__, *error);
		return SYSINFO_RET_FAIL;
	}

	/* Available space could be negative (top bit set) if we hit disk space */
	/* reserved for non-privileged users. Treat it as 0.                    */
	if (0 != ZBX_IS_TOP_BIT_SET(s.f_bavail))
		s.f_bavail = 0;

	if (NULL != total)
		*total = (zbx_uint64_t)s.f_blocks * s.ZBX_BSIZE;

	if (NULL != free)
		*free = (zbx_uint64_t)s.f_bavail * s.ZBX_BSIZE;

	if (NULL != used)
		*used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * s.ZBX_BSIZE;

	if (NULL != pfree)
	{
		if (0 != s.f_blocks - s.f_bfree + s.f_bavail)
			*pfree = (double)(100.0 * s.f_bavail) / (s.f_blocks - s.f_bfree + s.f_bavail);
		else
			*pfree = 0;
	}

	if (NULL != pused)
	{
		if (0 != s.f_blocks - s.f_bfree + s.f_bavail)
			*pused = 100.0 - (double)(100.0 * s.f_bavail) / (s.f_blocks - s.f_bfree + s.f_bavail);
		else
			*pused = 0;
	}

	return SYSINFO_RET_OK;
}

static int	VFS_FS_USED(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value;
	char		*error;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, &value, NULL, NULL, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_FREE(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value;
	char		*error;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, &value, NULL, NULL, NULL, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_TOTAL(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value;
	char		*error;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, &value, NULL, NULL, NULL, NULL, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_PFREE(const char *fs, AGENT_RESULT *result)
{
	double	value;
	char	*error;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, NULL, &value, NULL, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_DBL_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_PUSED(const char *fs, AGENT_RESULT *result)
{
	double	value;
	char	*error;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, NULL, NULL, &value, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_DBL_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	vfs_fs_size(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*fsname, *mode;

	if (2 < request->nparam)
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
		return SYSINFO_RET_FAIL;
	}

	fsname = get_rparam(request, 0);
	mode = get_rparam(request, 1);

	if (NULL == fsname || '\0' == *fsname)
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid first parameter."));
		return SYSINFO_RET_FAIL;
	}

	if (NULL == mode || '\0' == *mode || 0 == strcmp(mode, "total"))	/* default parameter */
		return VFS_FS_TOTAL(fsname, result);
	if (0 == strcmp(mode, "free"))
		return VFS_FS_FREE(fsname, result);
	if (0 == strcmp(mode, "pfree"))
		return VFS_FS_PFREE(fsname, result);
	if (0 == strcmp(mode, "used"))
		return VFS_FS_USED(fsname, result);
	if (0 == strcmp(mode, "pused"))
		return VFS_FS_PUSED(fsname, result);

	SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid second parameter."));

	return SYSINFO_RET_FAIL;
}

int	VFS_FS_SIZE(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	return zbx_execute_threaded_metric(vfs_fs_size, request, result);
}

int	VFS_FS_DISCOVERY(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	struct mntent	*mt;
	FILE		*f;
	struct zbx_json	j;

	/* opening the mounted filesystems file */
	if (NULL == (f = setmntent(MNT_MNTTAB, "r")))
	{
		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot obtain system information: %s", zbx_strerror(errno)));
		return SYSINFO_RET_FAIL;
	}

	zbx_json_initarray(&j, ZBX_JSON_STAT_BUF_LEN);

	/* fill mnttab structure from file */
	while (NULL != (mt = getmntent(f)))
	{
		zbx_json_addobject(&j, NULL);
		zbx_json_addstring(&j, ZBX_LLD_MACRO_FSNAME, mt->mnt_dir, ZBX_JSON_TYPE_STRING);
		zbx_json_addstring(&j, ZBX_LLD_MACRO_FSTYPE, mt->mnt_type, ZBX_JSON_TYPE_STRING);
		zbx_json_close(&j);
	}

	endmntent(f);

	zbx_json_close(&j);

	SET_STR_RESULT(result, zbx_strdup(NULL, j.buffer));

	zbx_json_free(&j);

	return SYSINFO_RET_OK;
}

static int	vfs_fs_get(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	struct mntent		*mt;
	FILE			*f;
	struct zbx_json		j;
	zbx_uint64_t		total, not_used, used;
	zbx_uint64_t		itotal, inot_used, iused;
	double			pfree, pused;
	double			ipfree, ipused;
	char 			*error;
	zbx_vector_ptr_t	mntpoints;
	zbx_mpoint_t		*mntpoint;
	char 			*mpoint;
	int			ret = SYSINFO_RET_FAIL;

	/* opening the mounted filesystems file */
	if (NULL == (f = setmntent(MNT_MNTTAB, "r")))
	{
		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot obtain system information: %s", zbx_strerror(errno)));
		return SYSINFO_RET_FAIL;
	}

	zbx_vector_ptr_create(&mntpoints);

	/* fill mnttab structure from file */
	while (NULL != (mt = getmntent(f)))
	{
		mpoint = mt->mnt_dir;
		if (SYSINFO_RET_OK != get_fs_size_stat(mpoint, &total, &not_used, &used, &pfree, &pused, &error))
		{
			zbx_free(error);
			continue;
		}
		if (SYSINFO_RET_OK != get_fs_inode_stat(mpoint, &itotal, &inot_used, &iused, &ipfree, &ipused, "pused",
				&error))
		{
			zbx_free(error);
			continue;
		}

		mntpoint = (zbx_mpoint_t *)zbx_malloc(NULL, sizeof(zbx_mpoint_t));
		zbx_strlcpy(mntpoint->fsname, mpoint, MAX_STRING_LEN);
		zbx_strlcpy(mntpoint->fstype, mt->mnt_type, MAX_STRING_LEN);
		mntpoint->bytes.total = total;
		mntpoint->bytes.used = used;
		mntpoint->bytes.not_used = not_used;
		mntpoint->bytes.pfree = pfree;
		mntpoint->bytes.pused = pused;
		mntpoint->inodes.total = itotal;
		mntpoint->inodes.used = iused;
		mntpoint->inodes.not_used = inot_used;
		mntpoint->inodes.pfree = ipfree;
		mntpoint->inodes.pused = ipused;

		zbx_vector_ptr_append(&mntpoints, mntpoint);
	}

	endmntent(f);

	if (NULL == (f = setmntent(MNT_MNTTAB, "r")))
	{
		SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot obtain system information: %s", zbx_strerror(errno)));
		goto out;
	}

	zbx_json_initarray(&j, ZBX_JSON_STAT_BUF_LEN);

	while (NULL != (mt = getmntent(f)))
	{
		int idx;

		mpoint = mt->mnt_dir;

		if (FAIL != (idx = zbx_vector_ptr_search(&mntpoints, mpoint, ZBX_DEFAULT_STR_COMPARE_FUNC)))
		{
			mntpoint = (zbx_mpoint_t *)mntpoints.values[idx];
			zbx_json_addobject(&j, NULL);
			zbx_json_addstring(&j, ZBX_SYSINFO_TAG_FSNAME, mntpoint->fsname, ZBX_JSON_TYPE_STRING);
			zbx_json_addstring(&j, ZBX_SYSINFO_TAG_FSTYPE, mntpoint->fstype, ZBX_JSON_TYPE_STRING);
			zbx_json_addobject(&j, ZBX_SYSINFO_TAG_BYTES);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_TOTAL, mntpoint->bytes.total);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_FREE, mntpoint->bytes.not_used);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_USED, mntpoint->bytes.used);
			zbx_json_addfloat(&j, ZBX_SYSINFO_TAG_PFREE, mntpoint->bytes.pfree);
			zbx_json_addfloat(&j, ZBX_SYSINFO_TAG_PUSED, mntpoint->bytes.pused);
			zbx_json_close(&j);
			zbx_json_addobject(&j, ZBX_SYSINFO_TAG_INODES);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_TOTAL, mntpoint->inodes.total);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_FREE, mntpoint->inodes.not_used);
			zbx_json_adduint64(&j, ZBX_SYSINFO_TAG_USED, mntpoint->inodes.used);
			zbx_json_addfloat(&j, ZBX_SYSINFO_TAG_PFREE, mntpoint->inodes.pfree);
			zbx_json_addfloat(&j, ZBX_SYSINFO_TAG_PUSED, mntpoint->inodes.pused);
			zbx_json_close(&j);
			zbx_json_close(&j);
		}
	}

	endmntent(f);

	zbx_json_close(&j);

	SET_STR_RESULT(result, zbx_strdup(NULL, j.buffer));

	zbx_json_free(&j);

	ret = SYSINFO_RET_OK;
out:
	zbx_vector_ptr_clear_ext(&mntpoints, (zbx_clean_func_t)zbx_mpoints_free);
	zbx_vector_ptr_destroy(&mntpoints);

	return ret;
}

int	VFS_FS_GET(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	return zbx_execute_threaded_metric(vfs_fs_get, request, result);

}

