/*
** Copyright (C) 2001-2025 Zabbix SIA
**
** This program is free software: you can redistribute it and/or modify it under the terms of
** the GNU Affero General Public License as published by the Free Software Foundation, version 3.
**
** 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 Affero General Public License for more details.
**
** You should have received a copy of the GNU Affero General Public License along with this program.
** If not, see <https://www.gnu.org/licenses/>.
**/

#include "zbxsysinfo.h"
#include "../sysinfo.h"
#include "../common/zbxsysinfo_common.h"

#include "zbxjson.h"
#include "zbxnum.h"

static struct ifmibdata	ifmd;

static int	get_ifmib_general(const char *if_name, char **error)
{
	int	mib[6], ifcount;
	size_t	len;

	if (NULL == if_name || '\0' == *if_name)
	{
		*error = zbx_strdup(NULL, "Network interface name cannot be empty.");
		return FAIL;
	}

	mib[0] = CTL_NET;
	mib[1] = PF_LINK;
	mib[2] = NETLINK_GENERIC;
	mib[3] = IFMIB_SYSTEM;
	mib[4] = IFMIB_IFCOUNT;

	len = sizeof(ifcount);

	if (-1 == sysctl(mib, 5, &ifcount, &len, NULL, 0))
	{
		*error = zbx_dsprintf(NULL, "Cannot obtain system information: %s", zbx_strerror(errno));
		return FAIL;
	}

	mib[3] = IFMIB_IFDATA;
	mib[5] = IFDATA_GENERAL;

	len = sizeof(ifmd);

	for (mib[4] = 1; mib[4] <= ifcount; mib[4]++)
	{
		if (-1 == sysctl(mib, 6, &ifmd, &len, NULL, 0))
		{
			if (ENOENT == errno)
				continue;

			break;
		}

		if (0 == strcmp(ifmd.ifmd_name, if_name))
			return SUCCEED;
	}

	*error = zbx_strdup(NULL, "Cannot find information for this network interface.");

	return FAIL;
}

int	net_if_in(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*if_name, *mode, *error;

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

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

	if (FAIL == get_ifmib_general(if_name,&error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	if (NULL == mode || '\0' == *mode || 0 == strcmp(mode, "bytes"))	/* default parameter */
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_ibytes);
	else if (0 == strcmp(mode, "packets"))
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_ipackets);
	else if (0 == strcmp(mode, "errors"))
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_ierrors);
	else if (0 == strcmp(mode, "dropped"))
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_iqdrops);
	else
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid second parameter."));
		return SYSINFO_RET_FAIL;
	}

	return SYSINFO_RET_OK;
}

int	net_if_out(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*if_name, *mode, *error;

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

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

	if (FAIL == get_ifmib_general(if_name, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	if (NULL == mode || '\0' == *mode || 0 == strcmp(mode, "bytes"))	/* default parameter */
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_obytes);
	else if (0 == strcmp(mode, "packets"))
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_opackets);
	else if (0 == strcmp(mode, "errors"))
		SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_oerrors);
	else
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid second parameter."));
		return SYSINFO_RET_FAIL;
	}

	return SYSINFO_RET_OK;
}

int	net_if_total(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*if_name, *mode, *error;

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

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

	if (FAIL == get_ifmib_general(if_name, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	if (NULL == mode || '\0' == *mode || 0 == strcmp(mode, "bytes"))	/* default parameter */
		SET_UI64_RESULT(result, (zbx_uint64_t)ifmd.ifmd_data.ifi_ibytes + ifmd.ifmd_data.ifi_obytes);
	else if (0 == strcmp(mode, "packets"))
		SET_UI64_RESULT(result, (zbx_uint64_t)ifmd.ifmd_data.ifi_ipackets + ifmd.ifmd_data.ifi_opackets);
	else if (0 == strcmp(mode, "errors"))
		SET_UI64_RESULT(result, (zbx_uint64_t)ifmd.ifmd_data.ifi_ierrors + ifmd.ifmd_data.ifi_oerrors);
	else
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid second parameter."));
		return SYSINFO_RET_FAIL;
	}

	return SYSINFO_RET_OK;
}

int	net_tcp_listen(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char		*port_str, command[64];
	unsigned short	port;
	int		res;

	if (1 < request->nparam)
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
		return SYSINFO_RET_FAIL;
	}

	port_str = get_rparam(request, 0);

	if (NULL == port_str || SUCCEED != zbx_is_ushort(port_str, &port))
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid first parameter."));
		return SYSINFO_RET_FAIL;
	}

	zbx_snprintf(command, sizeof(command), "netstat -an | grep '^tcp.*\\.%hu[^.].*LISTEN' | wc -l", port);

	if (SYSINFO_RET_FAIL == (res = execute_int(command, result, request->timeout)))
		return res;

	if (1 < result->ui64)
		result->ui64 = 1;

	return res;
}

int	net_udp_listen(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char		*port_str, command[64];
	unsigned short	port;
	int		res;

	if (1 < request->nparam)
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
		return SYSINFO_RET_FAIL;
	}

	port_str = get_rparam(request, 0);

	if (NULL == port_str || SUCCEED != zbx_is_ushort(port_str, &port))
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Invalid first parameter."));
		return SYSINFO_RET_FAIL;
	}

	zbx_snprintf(command, sizeof(command), "netstat -an | grep '^udp.*\\.%hu[^.].*\\*\\.\\*' | wc -l", port);

	if (SYSINFO_RET_FAIL == (res = execute_int(command, result, request->timeout)))
		return res;

	if (1 < result->ui64)
		result->ui64 = 1;

	return res;
}

int	net_if_collisions(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*if_name, *error;

	if (1 < request->nparam)
	{
		SET_MSG_RESULT(result, zbx_strdup(NULL, "Too many parameters."));
		return SYSINFO_RET_FAIL;
	}

	if_name = get_rparam(request, 0);

	if (FAIL == get_ifmib_general(if_name, &error))
	{
		SET_MSG_RESULT(result, error);
		return SYSINFO_RET_FAIL;
	}

	SET_UI64_RESULT(result, ifmd.ifmd_data.ifi_collisions);

	return SYSINFO_RET_OK;
}

int	net_if_discovery(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	struct zbx_json		j;
	struct if_nameindex	*interfaces;

	if (NULL == (interfaces = if_nameindex()))
	{
		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);

	for (int i = 0; 0 != interfaces[i].if_index; i++)
	{
		zbx_json_addobject(&j, NULL);
		zbx_json_addstring(&j, "{#IFNAME}", interfaces[i].if_name, ZBX_JSON_TYPE_STRING);
		zbx_json_close(&j);
	}

	zbx_json_close(&j);

	SET_STR_RESULT(result, strdup(j.buffer));

	zbx_json_free(&j);

	if_freenameindex(interfaces);

	return SYSINFO_RET_OK;
}
