Merge pull request #105 from nyaruka/parse_networks

Add `httpx.ParseNetworks` util function

httpx/access.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
 
@@ -52,3 +53,27 @@ func (c *AccessConfig) Allow(request *http.Request) (bool, error) {
 	}
 	return true, nil
 }
+
+// ParseNetworks parses a list of IPs and IP networks (written in CIDR notation)
+func ParseNetworks(addrs ...string) ([]net.IP, []*net.IPNet, error) {
+	ips := make([]net.IP, 0, len(addrs))
+	ipNets := make([]*net.IPNet, 0, len(addrs))
+
+	for _, addr := range addrs {
+		if strings.Contains(addr, "/") {
+			_, ipNet, err := net.ParseCIDR(addr)
+			if err != nil {
+				return nil, nil, errors.Errorf("couldn't parse '%s' as an IP network", addr)
+			}
+			ipNets = append(ipNets, ipNet)
+		} else {
+			ip := net.ParseIP(addr)
+			if ip == nil {
+				return nil, nil, errors.Errorf("couldn't parse '%s' as an IP address", addr)
+			}
+			ips = append(ips, ip)
+		}
+	}
+
+	return ips, ipNets, nil
+}

httpx/access_test.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/nyaruka/gocommon/httpx"
-
 	"github.com/stretchr/testify/assert"
 )
 
@@ -68,3 +67,32 @@ func TestAccessConfig(t *testing.T) {
 		}
 	}
 }
+
+func TestParseNetworkList(t *testing.T) {
+	privateNetwork1 := &net.IPNet{IP: net.IPv4(10, 0, 0, 0).To4(), Mask: net.CIDRMask(8, 32)}
+	privateNetwork2 := &net.IPNet{IP: net.IPv4(172, 16, 0, 0).To4(), Mask: net.CIDRMask(12, 32)}
+	privateNetwork3 := &net.IPNet{IP: net.IPv4(192, 168, 0, 0).To4(), Mask: net.CIDRMask(16, 32)}
+
+	linkLocalIPv4 := &net.IPNet{IP: net.IPv4(169, 254, 0, 0).To4(), Mask: net.CIDRMask(16, 32)}
+	_, linkLocalIPv6, _ := net.ParseCIDR("fe80::/10")
+
+	// test with mailroom defaults
+	ips, ipNets, err := httpx.ParseNetworks(`127.0.0.1`, `::1`, `10.0.0.0/8`, `172.16.0.0/12`, `192.168.0.0/16`, `169.254.0.0/16`, `fe80::/10`)
+	assert.NoError(t, err)
+	assert.Equal(t, []net.IP{net.IPv4(127, 0, 0, 1), net.ParseIP(`::1`)}, ips)
+	assert.Equal(t, []*net.IPNet{privateNetwork1, privateNetwork2, privateNetwork3, linkLocalIPv4, linkLocalIPv6}, ipNets)
+
+	// test with empty
+	ips, ipNets, err = httpx.ParseNetworks()
+	assert.NoError(t, err)
+	assert.Equal(t, []net.IP{}, ips)
+	assert.Equal(t, []*net.IPNet{}, ipNets)
+
+	// test with invalid IP
+	_, _, err = httpx.ParseNetworks(`127.0.1`)
+	assert.EqualError(t, err, `couldn't parse '127.0.1' as an IP address`)
+
+	// test with invalid network
+	_, _, err = httpx.ParseNetworks(`127.0.0.1/x`)
+	assert.EqualError(t, err, `couldn't parse '127.0.0.1/x' as an IP network`)
+}