Support decoding inet/cidr to net.IP

fixes #137

README.md

@@ -20,7 +20,7 @@ Pgx supports many additional features beyond what is available through database/
 * PostgreSQL array to Go slice mapping for integers, floats, and strings
 * Hstore support
 * JSON and JSONB support
-* Maps inet and cidr PostgreSQL types to net.IPNet
+* Maps inet and cidr PostgreSQL types to net.IPNet and net.IP
 * Large object support
 * Null mapping to Null* struct or pointer to pointer.
 * Supports database/sql.Scanner and database/sql/driver.Valuer interfaces for custom types

values.go

@@ -764,6 +764,22 @@ func Decode(vr *ValueReader, d interface{}) error {
 		default:
 			return fmt.Errorf("Can't convert OID %v to time.Time", vr.Type().DataType)
 		}
+	case *net.IP:
+		ipnet := decodeInet(vr)
+		if oneCount, bitCount := ipnet.Mask.Size(); oneCount != bitCount {
+			return fmt.Errorf("Cannot decode netmask into *net.IP")
+		}
+		*v = ipnet.IP
+	case *[]net.IP:
+		ipnets := decodeInetArray(vr)
+		ips := make([]net.IP, len(ipnets))
+		for i, ipnet := range ipnets {
+			if oneCount, bitCount := ipnet.Mask.Size(); oneCount != bitCount {
+				return fmt.Errorf("Cannot decode netmask into *net.IP")
+			}
+			ips[i] = ipnet.IP
+		}
+		*v = ips
 	case *net.IPNet:
 		*v = decodeInet(vr)
 	case *[]net.IPNet:
@@ -1436,15 +1452,14 @@ func decodeInet(vr *ValueReader) net.IPNet {
 	}
 
 	pgType := vr.Type()
-	if vr.Len() != 8 && vr.Len() != 20 {
-		vr.Fatal(ProtocolError(fmt.Sprintf("Received an invalid size for a %s: %d", pgType.Name, vr.Len())))
-		return zero
-	}
-
 	if pgType.DataType != InetOid && pgType.DataType != CidrOid {
 		vr.Fatal(ProtocolError(fmt.Sprintf("Cannot decode oid %v into %s", pgType.DataType, pgType.Name)))
 		return zero
 	}
+	if vr.Len() != 8 && vr.Len() != 20 {
+		vr.Fatal(ProtocolError(fmt.Sprintf("Received an invalid size for a %s: %d", pgType.Name, vr.Len())))
+		return zero
+	}
 
 	vr.ReadByte() // ignore family
 	bits := vr.ReadByte()

values_test.go

@@ -1,12 +1,13 @@
 package pgx_test
 
 import (
-	"github.com/jackc/pgx"
 	"net"
 	"reflect"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/jackc/pgx"
 )
 
 func TestDateTranscode(t *testing.T) {
@@ -258,7 +259,7 @@ func TestStringToNotTextTypeTranscode(t *testing.T) {
 	}
 }
 
-func TestInetCidrTranscode(t *testing.T) {
+func TestInetCidrTranscodeIPNet(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -307,7 +308,67 @@ func TestInetCidrTranscode(t *testing.T) {
 	}
 }
 
-func TestInetCidrArrayTranscode(t *testing.T) {
+func TestInetCidrTranscodeIP(t *testing.T) {
+	t.Parallel()
+
+	conn := mustConnect(t, *defaultConnConfig)
+	defer closeConn(t, conn)
+
+	tests := []struct {
+		sql   string
+		value net.IP
+	}{
+		{"select $1::inet", net.ParseIP("0.0.0.0")},
+		{"select $1::inet", net.ParseIP("127.0.0.1")},
+		{"select $1::inet", net.ParseIP("12.34.56.0")},
+		{"select $1::inet", net.ParseIP("255.255.255.255")},
+		{"select $1::inet", net.ParseIP("::1")},
+		{"select $1::inet", net.ParseIP("2607:f8b0:4009:80b::200e")},
+		{"select $1::cidr", net.ParseIP("0.0.0.0")},
+		{"select $1::cidr", net.ParseIP("127.0.0.1")},
+		{"select $1::cidr", net.ParseIP("12.34.56.0")},
+		{"select $1::cidr", net.ParseIP("255.255.255.255")},
+		{"select $1::cidr", net.ParseIP("::1")},
+		{"select $1::cidr", net.ParseIP("2607:f8b0:4009:80b::200e")},
+	}
+
+	for i, tt := range tests {
+		var actual net.IP
+
+		err := conn.QueryRow(tt.sql, tt.value).Scan(&actual)
+		if err != nil {
+			t.Errorf("%d. Unexpected failure: %v (sql -> %v, value -> %v)", i, err, tt.sql, tt.value)
+			continue
+		}
+
+		if !actual.Equal(tt.value) {
+			t.Errorf("%d. Expected %v, got %v (sql -> %v)", i, tt.value, actual, tt.sql)
+		}
+
+		ensureConnValid(t, conn)
+	}
+
+	failTests := []struct {
+		sql   string
+		value net.IPNet
+	}{
+		{"select $1::inet", mustParseCIDR(t, "192.168.1.0/24")},
+		{"select $1::cidr", mustParseCIDR(t, "192.168.1.0/24")},
+	}
+	for i, tt := range failTests {
+		var actual net.IP
+
+		err := conn.QueryRow(tt.sql, tt.value).Scan(&actual)
+		if !strings.Contains(err.Error(), "Cannot decode netmask") {
+			t.Errorf("%d. Expected failure cannot decode netmask, but got: %v (sql -> %v, value -> %v)", i, err, tt.sql, tt.value)
+			continue
+		}
+
+		ensureConnValid(t, conn)
+	}
+}
+
+func TestInetCidrArrayTranscodeIPNet(t *testing.T) {
 	t.Parallel()
 
 	conn := mustConnect(t, *defaultConnConfig)
@@ -366,6 +427,87 @@ func TestInetCidrArrayTranscode(t *testing.T) {
 	}
 }
 
+func TestInetCidrArrayTranscodeIP(t *testing.T) {
+	t.Parallel()
+
+	conn := mustConnect(t, *defaultConnConfig)
+	defer closeConn(t, conn)
+
+	tests := []struct {
+		sql   string
+		value []net.IP
+	}{
+		{
+			"select $1::inet[]",
+			[]net.IP{
+				net.ParseIP("0.0.0.0"),
+				net.ParseIP("127.0.0.1"),
+				net.ParseIP("12.34.56.0"),
+				net.ParseIP("255.255.255.255"),
+				net.ParseIP("2607:f8b0:4009:80b::200e"),
+			},
+		},
+		{
+			"select $1::cidr[]",
+			[]net.IP{
+				net.ParseIP("0.0.0.0"),
+				net.ParseIP("127.0.0.1"),
+				net.ParseIP("12.34.56.0"),
+				net.ParseIP("255.255.255.255"),
+				net.ParseIP("2607:f8b0:4009:80b::200e"),
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		var actual []net.IP
+
+		err := conn.QueryRow(tt.sql, tt.value).Scan(&actual)
+		if err != nil {
+			t.Errorf("%d. Unexpected failure: %v (sql -> %v, value -> %v)", i, err, tt.sql, tt.value)
+			continue
+		}
+
+		if !reflect.DeepEqual(actual, tt.value) {
+			t.Errorf("%d. Expected %v, got %v (sql -> %v)", i, tt.value, actual, tt.sql)
+		}
+
+		ensureConnValid(t, conn)
+	}
+
+	failTests := []struct {
+		sql   string
+		value []net.IPNet
+	}{
+		{
+			"select $1::inet[]",
+			[]net.IPNet{
+				mustParseCIDR(t, "12.34.56.0/32"),
+				mustParseCIDR(t, "192.168.1.0/24"),
+			},
+		},
+		{
+			"select $1::cidr[]",
+			[]net.IPNet{
+				mustParseCIDR(t, "12.34.56.0/32"),
+				mustParseCIDR(t, "192.168.1.0/24"),
+			},
+		},
+	}
+
+	for i, tt := range failTests {
+		var actual []net.IP
+
+		err := conn.QueryRow(tt.sql, tt.value).Scan(&actual)
+		if err == nil || !strings.Contains(err.Error(), "Cannot decode netmask") {
+			t.Errorf("%d. Expected failure cannot decode netmask, but got: %v (sql -> %v, value -> %v)", i, err, tt.sql, tt.value)
+			continue
+		}
+
+		ensureConnValid(t, conn)
+	}
+}
+
 func TestInetCidrTranscodeWithJustIP(t *testing.T) {
 	t.Parallel()