shad-go/iprange/funcs.go

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2022-04-14 01:36:15 +00:00
//go:build !solution
package iprange
import (
"encoding/binary"
"net"
"sort"
)
func streamRange(lower, upper net.IP) chan net.IP {
ipchan := make(chan net.IP, 1)
rangeMask := net.IP([]byte{
upper[0] - lower[0],
upper[1] - lower[1],
upper[2] - lower[2],
upper[3] - lower[3],
})
go func() {
defer close(ipchan)
lower32 := binary.BigEndian.Uint32([]byte(lower))
upper32 := binary.BigEndian.Uint32([]byte(upper))
diff := upper32 - lower32
if diff < 0 {
panic("Lower address is actually higher than upper address.")
}
mask := net.IP([]byte{0, 0, 0, 0})
for {
ipchan <- net.IP([]byte{
lower[0] + mask[0],
lower[1] + mask[1],
lower[2] + mask[2],
lower[3] + mask[3],
})
if mask.Equal(rangeMask) {
break
}
for i := 3; i >= 0; i-- {
if rangeMask[i] > 0 {
if mask[i] < rangeMask[i] {
mask[i] = mask[i] + 1
break
} else {
mask[i] = mask[i] % rangeMask[i]
if i < 1 {
break
}
}
}
}
}
}()
return ipchan
}
// Expand expands an address with a mask taken from a stream
func (r *AddressRange) Expand() []net.IP {
ips := []net.IP{}
for ip := range streamRange(r.Min, r.Max) {
ips = append(ips, ip)
}
return ips
}
// Expand expands and normalizes a set of parsed target specifications
func (l AddressRangeList) Expand() []net.IP {
var res []net.IP
for i := range l {
res = append(res, l[i].Expand()...)
}
return normalize(res)
}
func normalize(src []net.IP) []net.IP {
sort.Sort(asc(src))
dst := make([]net.IP, 1, len(src))
dst[0] = src[0]
for i := range src {
if !dst[len(dst)-1].Equal(src[i]) {
dst = append(dst, src[i])
}
}
return dst
}