79 lines
1.2 KiB
Go
79 lines
1.2 KiB
Go
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package ipfunc
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import (
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"errors"
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"fmt"
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"net"
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"sync"
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)
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type IPSubnet struct {
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freeIPs []string
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mux sync.Mutex
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}
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func NewIPSubnet(network string) (IPSubnet, error) {
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i := IPSubnet{}
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ip, ipnet, err := net.ParseCIDR(network)
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if err != nil {
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return IPSubnet{}, fmt.Errorf("Cant create IPSubnet, input ip cant pase: %w", err)
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}
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var ips []string
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for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
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ips = append(ips, ip.String())
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}
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lenIPs := len(ips)
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switch {
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case lenIPs < 2:
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i.freeIPs = ips
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default:
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i.freeIPs = ips[1 : len(ips)-1]
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}
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return i, nil
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}
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func (i *IPSubnet) GetNextFreeIP() (string, error) {
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if len(i.freeIPs) == 0 {
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return "", errors.New("No free IP")
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}
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i.mux.Lock()
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defer i.mux.Unlock()
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rip := i.freeIPs[0]
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i.remove(rip)
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return rip, nil
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}
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func (i *IPSubnet) remove (ip string) {
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var newips []string
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for _, oneIp := range i.freeIPs {
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if oneIp != ip {
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newips = append(newips, oneIp)
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}
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}
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i.freeIPs = newips
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}
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func (i *IPSubnet)Remove(ip string) {
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i.mux.Lock()
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defer i.mux.Unlock()
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i.remove(ip)
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}
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func inc(ip net.IP) {
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for j := len(ip) - 1; j >= 0; j-- {
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ip[j]++
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if ip[j] > 0 {
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break
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}
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}
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}
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