关于go:校验IP

代码如下 (main.go)：

package main
 
import (
    "flag"
    "fmt"
    "net"
    "strings"
)
 
const IPV4 = 4
const IPV6 = 6
 
func getIPType(ip string) int {for i := 0; i < len(ip); i++ {switch ip[i] {
        case '.':
            return IPV4
        case ':':
            return IPV6
        }
    }
    return 0
}
 
func main() {
    // Define flags
    macPtr := flag.String("mac", "","MAC address")
    sipPtr := flag.String("sip", "","Source IP address")
    dipPtr := flag.String("dip", "","Destination IP address")
    vlanidPtr := flag.Int("vlanid", -1, "VLAN ID")
    intfNamePtr := flag.String("intf_name", "","Interface name")
 
    // Parse flags
    flag.Parse()
 
    // Check if all flags are provided
    if *macPtr == ""|| *sipPtr =="" || *dipPtr == ""|| *vlanidPtr == 0 || *intfNamePtr =="" {fmt.Println("Usage: go run check.go -mac <mac> -sip <sip> -dip <dip> -vlanid <vlanid> -intf_name <intf_name>")
        return
    }
 
    // Check if the VLAN ID is valid
    if *vlanidPtr < 1 || *vlanidPtr > 4095 {fmt.Println("Invalid VLAN ID")
        return
    }
 
    // Check if the interface name is valid
    if len(*intfNamePtr) > 100 {fmt.Println("Interface name is too long")
        return
    }
 
    // Parse the MAC address
    mac, err := net.ParseMAC(*macPtr)
    if err != nil {fmt.Println("Invalid MAC address")
        return
    }
 
    // Check if the source IP address and destination IP address are of the same type
    if getIPType(*sipPtr) != getIPType(*dipPtr) {fmt.Println("Both source and destination IP addresses must be of the same type IPv4/IPv6")
        return
    }
 
    // Parse the source IP address
    sip := net.ParseIP(*sipPtr)
    if sip == nil {fmt.Println("Invalid source IP address")
        return
    }
 
    // Parse the destination IP address
    dip := net.ParseIP(*dipPtr)
    if dip == nil {fmt.Println("Invalid destination IP address")
        return
    }
 
    //Print the validated arguments
    fmt.Printf("MAC address: %s\n", mac)
    fmt.Printf("Source IP address: %s\n", sip)
    fmt.Printf("Destination IP address: %s\n", dip)
    fmt.Printf("VLAN ID: %d\n", *vlanidPtr)
    fmt.Printf("Interface name: %s\n", strings.TrimSpace(*intfNamePtr))
}

编译：
go build -o check main.go

执行

% ./check --help                                                                            
Usage of ./check:
  -dip string
        Destination IP address
  -intf_name string
        Interface name
  -mac string
        MAC address
  -sip string
        Source IP address
  -vlanid int
        VLAN ID (default -1)

./check -mac A1:2B:C3:4D:E5:6F -sip 192.168.1.1 -dip 127.0.0.1 -intf_name abc -vlanid 10
MAC address: a1:2b:c3:4d:e5:6f
Source IP address: 192.168.1.1
Destination IP address: 127.0.0.1
VLAN ID: 10
Interface name: abc