100 lines
1.6 KiB
Go
100 lines
1.6 KiB
Go
package arpdis
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import (
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"net"
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"sync"
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"time"
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)
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const (
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StaleTimeNormal = time.Minute * 5
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StaleTimeUnreachable = time.Minute * 10
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TypeNormal = 0
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TypeUnreachable = 1
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TypeStatic = 2
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)
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var (
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table = make(map[string]*Addr)
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tableMu sync.RWMutex
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)
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type Addr struct {
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IP net.IP
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HardwareAddr net.HardwareAddr
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disTime time.Time
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Type int8
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}
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func Lookup(ip net.IP, onlyTable bool) *Addr {
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addr := tableLookup(ip.To4())
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if addr != nil || onlyTable {
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return addr
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}
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addr = doLookup(ip.To4())
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Add(addr)
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return addr
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}
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// Add adds a IP-MAC map to a runtime ARP table.
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func tableLookup(ip net.IP) *Addr {
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tableMu.Lock()
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addr := table[ip.To4().String()]
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tableMu.Unlock()
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if addr == nil {
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return nil
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}
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// 判断老化过期时间
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tsub := time.Since(addr.disTime)
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switch addr.Type {
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case TypeNormal:
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if tsub > StaleTimeNormal {
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return nil
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}
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case TypeUnreachable:
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if tsub > StaleTimeUnreachable {
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return nil
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}
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case TypeStatic:
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}
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return addr
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}
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// Add adds a IP-MAC map to a runtime ARP table.
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func Add(addr *Addr) {
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if addr == nil {
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return
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}
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if addr.disTime.IsZero() {
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addr.disTime = time.Now()
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}
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ip := addr.IP.To4().String()
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tableMu.Lock()
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defer tableMu.Unlock()
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if a, ok := table[ip]; ok {
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// 静态地址只能设置一次
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if a.Type == TypeStatic {
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return
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}
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}
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table[ip] = addr
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}
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// Delete removes an IP from the runtime ARP table.
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func Delete(ip net.IP) {
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tableMu.Lock()
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defer tableMu.Unlock()
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delete(table, ip.To4().String())
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}
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// List returns the current runtime ARP table.
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func List() map[string]*Addr {
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tableMu.RLock()
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defer tableMu.RUnlock()
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return table
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}
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