Zabbix

/*

** Zabbix

** Copyright (C) 2001-2023 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.

**/

​

package zbxnet

​

import (

    "fmt"

    "net"

    "regexp"

    "strings"

)

​

// AllowedPeers is preparsed content of field Server

type AllowedPeers struct {

    ips   []net.IP

    nets  []*net.IPNet

    names []string

}

​

// GetAllowedPeers is parses the Server field

func GetAllowedPeers(servers string) (allowedPeers *AllowedPeers, err error) {

    const duplicateErrorMessage = "cannot parse the \"Server\" parameter: address \"%s\" specified more than once"

    const regexDNSString = `^([a-zA-Z0-9_]{1}[a-zA-Z0-9_-]{0,62}){1}(\.[a-zA-Z0-9_]{1}[a-zA-Z0-9_-]{0,62})*[\._]?$`

​

    ap := &AllowedPeers{}

​

    if servers != "" {

        opts := strings.Split(servers, ",")

        for _, o := range opts {

            peer := strings.Trim(o, " \t")

            if _, peerNet, err := net.ParseCIDR(peer); nil == err {

                if ap.isPresent(peerNet) {

                    return &AllowedPeers{}, fmt.Errorf(duplicateErrorMessage, peer)

                }

​

                ap.nets = append(ap.nets, peerNet)

                maskLeadSize, maskTotalOnes := peerNet.Mask.Size()

                if 0 == maskLeadSize && 128 == maskTotalOnes {

                    _, peerNet, _ = net.ParseCIDR("0.0.0.0/0")

                    if !ap.isPresent(peerNet) {

                        ap.nets = append(ap.nets, peerNet)

                    }

                }

            } else if peerip := net.ParseIP(peer); nil != peerip {

                if ap.isPresent(peerip) {

                    return &AllowedPeers{}, fmt.Errorf(duplicateErrorMessage, peer)

                }