1 files changed, 149 insertions, 0 deletions
diff --git a/src/nslcd_proto/io.go b/src/nslcd_proto/io.go
new file mode 100644
index 0000000..0804e98
--- /dev/null
+++ b/src/nslcd_proto/io.go
@@ -0,0 +1,149 @@
+package nslcd_proto
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"reflect"
+)
+
+//#include <sys/socket.h>
+import "C"
+
+type NslcdObject interface {
+	NslcdWrite(fd io.Writer)
+}
+type NslcdObjectPtr interface {
+	NslcdRead(fd io.Reader)
+}
+
+func write(fd io.Writer, data interface{}) {
+	switch data := data.(type) {
+	// basic data types
+	case []byte:
+		_, err := fd.Write(data)
+		if err != nil {
+			panic(err)
+		}
+	case int32:
+		err := binary.Write(fd, binary.BigEndian, data)
+		if err != nil {
+			panic(err)
+		}
+	case NslcdObject:
+		data.NslcdWrite(fd)
+	// composite datatypes
+	case string:
+		write(fd, int32(len(data)))
+		write(fd, []byte(data))
+	case []string:
+		write(fd, int32(len(data)))
+		for _, item := range data {
+			write(fd, item)
+		}
+	case net.IP:
+		var af int32 = -1
+		switch len(data) {
+		case net.IPv4len:
+			af = C.AF_INET
+		case net.IPv6len:
+			af = C.AF_INET6
+		}
+		var bytes []byte
+		if af < 0 {
+			bytes = make([]byte, 0)
+		} else {
+			bytes = data
+		}
+		write(fd, af)
+		write(fd, int32(len(bytes)))
+		write(fd, bytes)
+	case []net.IP:
+		write(fd, int32(len(data)))
+		for _, item := range data {
+			write(fd, item)
+		}
+	default:
+		v := reflect.ValueOf(data)
+		switch v.Kind() {
+		case reflect.Struct:
+			for i, n := 0, v.NumField(); i < n; i++ {
+				write(fd, v.Field(i).Interface())
+			}
+		default:
+			panic("Invalid structure for NSLCD protocol data")
+		}
+	}
+	panic("not reached")
+}
+
+func read(fd io.Reader, data interface{}) {
+	switch data := data.(type) {
+	// basic data types
+	case *[]byte:
+		_, err := fd.Read(*data)
+		if err != nil {
+			panic(err)
+		}
+	case *int32:
+		err := binary.Read(fd, binary.BigEndian, data)
+		if err != nil {
+			panic(err)
+		}
+	case NslcdObjectPtr:
+		data.NslcdRead(fd)
+	// composite datatypes
+	case *string:
+		var len int32
+		read(fd, &len)
+		buf := make([]byte, len)
+		read(fd, &buf)
+		*data = string(buf)
+	case *[]string:
+		var num int32
+		read(fd, &num)
+		*data = make([]string, num)
+		for i := 0; i < int(num); i++ {
+			read(fd, &((*data)[i]))
+		}
+	case *net.IP:
+		var af int32
+		read(fd, &af)
+		var _len int32
+		switch af {
+		case C.AF_INET:
+			_len = net.IPv4len
+		case C.AF_INET6:
+			_len = net.IPv6len
+		default:
+			panic(NslcdError(fmt.Sprintf("incorrect address family specified: %d", af)))
+		}
+		var len int32
+		read(fd, &len)
+		if len != _len {
+			panic(NslcdError(fmt.Sprintf("address length incorrect: %d", len)))
+		}
+		buf := make([]byte, len)
+		read(fd, &buf)
+		*data = buf
+	case *[]net.IP:
+		var num int32
+		read(fd, &num)
+		*data = make([]net.IP, num)
+		for i := 0; i < int(num); i++ {
+			read(fd, &((*data)[i]))
+		}
+	default:
+		v := reflect.ValueOf(data)
+		switch v.Kind() {
+		case reflect.Struct:
+			for i, n := 0, v.NumField(); i < n; i++ {
+				read(fd, v.Field(i).Interface())
+			}
+		default:
+			panic("Invalid structure for NSLCD protocol data")
+		}
+	}
+	panic("not reached")
+}