iplist/cidr.go

   1 package iplist
   2
   3 import (
   4         "bufio"
   5         "io"
   6         "net"
   7 )
   8
   9 func ParseCIDRListReader(r io.Reader) (ret []Range, err error) {
  10         s := bufio.NewScanner(r)
  11         for s.Scan() {
  12                 err = func() (err error) {
  13                         _, in, err := net.ParseCIDR(s.Text())
  14                         if err != nil {
  15                                 return
  16                         }
  17                         ret = append(ret, Range{
  18                                 First: in.IP,
  19                                 Last:  IPNetLast(in),
  20                         })
  21                         return
  22                 }()
  23                 if err != nil {
  24                         return
  25                 }
  26         }
  27         return
  28 }
  29
  30 // Returns the last, inclusive IP in a net.IPNet.
  31 func IPNetLast(in *net.IPNet) (last net.IP) {
  32         n := len(in.IP)
  33         if n != len(in.Mask) {
  34                 panic("wat")
  35         }
  36         last = make(net.IP, n)
  37         for i := 0; i < n; i++ {
  38                 last[i] = in.IP[i] | ^in.Mask[i]
  39         }
  40         return
  41 }