src

Go monorepo.
git clone git://code.dwrz.net/src
Log | Files | Refs

eth.go (1231B)

      1 package eth
      2 
      3 import (
      4 	"context"
      5 	"fmt"
      6 	"net"
      7 )
      8 
      9 type Config struct {
     10 	Iface string `json:"iface"`
     11 }
     12 
     13 type Block struct {
     14 	iface string
     15 }
     16 
     17 func New(iface string) *Block {
     18 	return &Block{iface: iface}
     19 }
     20 
     21 func (b *Block) Name() string {
     22 	return "eth"
     23 }
     24 
     25 func (b *Block) Render(ctx context.Context) (string, error) {
     26 	iface, err := net.InterfaceByName(b.iface)
     27 	if err != nil {
     28 		if err.Error() == "route ip+net: no such network interface" {
     29 			return " ", nil
     30 		}
     31 		return "", fmt.Errorf(
     32 			"failed to get interface %s: %v", b.iface, err,
     33 		)
     34 	}
     35 
     36 	var ip4, ip6 string
     37 	addrs, err := iface.Addrs()
     38 	if err != nil {
     39 		return "", fmt.Errorf("failed to get addresses: %v", err)
     40 	}
     41 
     42 	for _, addr := range addrs {
     43 		a := addr.String()
     44 		if isIPv4(a) {
     45 			ip4 = a
     46 			continue
     47 		} else {
     48 			ip6 = a
     49 		}
     50 	}
     51 
     52 	switch {
     53 	case ip4 == "" && ip6 == "":
     54 		return " ", nil
     55 	case ip4 != "" && ip6 == "":
     56 		return fmt.Sprintf(" %s", ip4), nil
     57 	case ip4 == "" && ip6 != "":
     58 		return fmt.Sprintf(" %s", ip6), nil
     59 	default:
     60 		return fmt.Sprintf(" %s %s", ip4, ip6), nil
     61 	}
     62 }
     63 
     64 func isIPv4(s string) bool {
     65 	for i := 0; i < len(s); i++ {
     66 		switch s[i] {
     67 		case '.':
     68 			return true
     69 		case ':':
     70 			return false
     71 		}
     72 	}
     73 
     74 	return false
     75 }