ip match in golang

ipmatcher.go

type IPMatcher struct {
    IP net.IP
    SubNet *net.IPNet
}
type IPMatchers []*IPMatcher

func NewIPMatcher(ipStr string) (*IPMatcher, error) {
    ip, subNet, err := net.ParseCIDR(ipStr)
    if err != nil {
        ip = net.ParseIP(ipStr)
        if ip == nil {
            return nil, errors.New("invalid IP: "+ipStr)
        }
    }
    return &IPMatcher{ip, subNet}, nil
}

func (m IPMatcher) Match(ipStr string) bool {
    ip := net.ParseIP(ipStr)
    if ip == nil {
        return false
    }
    return m.IP.Equal(ip) || m.SubNet != nil && m.SubNet.Contains(ip)
}

func NewIPMatchers(ips []string) (list IPMatchers, err error) {
    for _, ipStr := range ips {
        var m *IPMatcher
        m, err = NewIPMatcher(ipStr)
        if err != nil {
            return
        }
        list = append(list, m)
    }
    return
}

func IPContains(ipMatchers []*IPMatcher, ip string) bool {
    for _, m := range ipMatchers {
        if m.Match(ip) {
            return true
        }
    }
    return false
}

func (ms IPMatchers) Match(ip string) bool {
    return IPContains(ms, ip)
}

ipmatcher_test.go

package utils

import "testing"

func TestIPMatcher(t *testing.T)  {
    a, errA := NewIPMatcher("127.0.0.1")
    if errA != nil {
        t.Error(errA)
    }
    if a.IP.String() != "127.0.0.1" || a.SubNet != nil {
        t.Error("ip parse error")
    }

    b, errB := NewIPMatcher("192.168.1.1/24")
    if errB != nil {
        t.Error(errB)
    }
    if b.IP.String() != "192.168.1.1" || b.SubNet == nil {
        t.Errorf("ip match error: %s, %v", b.IP.String(), b.SubNet)
    }
    if !b.Match("192.168.1.1") || !b.Match("192.168.1.2") {
        t.Error("ip match error")
    }
}

func TestIPMatchers(t *testing.T)  {
    var WhiteListIPs = []string{"127.0.0.1", "192.168.1.0/24", "10.1.0.0/16"}
    M, err := NewIPMatchers(WhiteListIPs)
    if err != nil {
        t.Error(err)
    }
    if !M.Match("127.0.0.1") || !M.Match("192.168.1.1") || !M.Match("192.168.1.199") ||
        !M.Match("10.1.0.1") || !M.Match("10.1.3.1") {
        t.Error("ip match error")
    }
    if M.Match("127.0.0.2") || M.Match("192.168.2.1") || M.Match("10.2.0.1") {
        t.Error("ip match error 2")
    }
}