Add socket operations

builtins/accept.go

@@ -0,0 +1,32 @@
+package builtins
+
+import (
+	"monkey/object"
+	"monkey/typing"
+	"syscall"
+)
+
+// Accept  ...
+func Accept(args ...object.Object) object.Object {
+	if err := typing.Check(
+		"accept", args,
+		typing.ExactArgs(1),
+		typing.WithTypes(object.INTEGER_OBJ),
+	); err != nil {
+		return newError(err.Error())
+	}
+
+	var (
+		nfd syscall.Handle
+		err error
+	)
+
+	fd := int(args[0].(*object.Integer).Value)
+
+	nfd, _, err = syscall.Accept(syscall.Handle(fd))
+	if err != nil {
+		return newError("SocketError: %s", err)
+	}
+
+	return &object.Integer{Value: int64(nfd)}
+}

builtins/bind.go

@@ -0,0 +1,54 @@
+package builtins
+
+import (
+	"monkey/object"
+	"monkey/typing"
+	"syscall"
+)
+
+// Bind ...
+func Bind(args ...object.Object) object.Object {
+	if err := typing.Check(
+		"bind", args,
+		typing.ExactArgs(2),
+		typing.WithTypes(object.INTEGER_OBJ, object.INTEGER_OBJ),
+	); err != nil {
+		return newError(err.Error())
+	}
+
+	var (
+		err      error
+		sockaddr syscall.Sockaddr
+	)
+
+	fd := int(args[0].(*object.Integer).Value)
+	address := args[1].(*object.String).Value
+
+	sockaddr, err = syscall.Getsockname(syscall.Handle(fd))
+	if err != nil {
+		return newError("ValueError: %s", err)
+	}
+
+	if _, ok := sockaddr.(*syscall.SockaddrInet4); ok {
+		addr, port, err := parseV4Address(address)
+		if err != nil {
+			return newError("ValueError: Invalid IPv4 address '%s': %s", address, err)
+		}
+		sockaddr = &syscall.SockaddrInet4{Addr: addr, Port: port}
+	} else if _, ok := sockaddr.(*syscall.SockaddrInet6); ok {
+		addr, port, err := parseV6Address(address)
+		if err != nil {
+			return newError("ValueError: Invalid IPv6 address '%s': %s", address, err)
+		}
+		sockaddr = &syscall.SockaddrInet6{Addr: addr, Port: port}
+	} else {
+		return newError("ValueError: Invalid socket type %T for bind '%s'", sockaddr, address)
+	}
+
+	err = syscall.Bind(syscall.Handle(fd), sockaddr)
+	if err != nil {
+		return newError("SocketError: %s", err)
+	}
+
+	return &object.Null{}
+}

builtins/builtins.go

@@ -50,6 +50,11 @@ var Builtins = map[string]*object.Builtin{
 	"write":     {Name: "write", Fn: Write},
 	"read":      {Name: "read", Fn: Read},
 	"seek":      {Name: "seek", Fn: Seek},
+	"socket":    {Name: "socket", Fn: Socket},
+	"bind":      {Name: "bind", Fn: Bind},
+	"accept":    {Name: "accept", Fn: Accept},
+	"listen":    {Name: "listen", Fn: Listen},
+	"connect":   {Name: "connect", Fn: Connect},
 }
 
 // BuiltinsIndex ...

builtins/connect.go

@@ -0,0 +1,50 @@
+package builtins
+
+import (
+	"monkey/object"
+	"monkey/typing"
+	"syscall"
+)
+
+// Connect ...
+func Connect(args ...object.Object) object.Object {
+	if err := typing.Check(
+		"connect", args,
+		typing.ExactArgs(2),
+		typing.WithTypes(object.INTEGER_OBJ, object.STRING_OBJ),
+	); err != nil {
+		return newError(err.Error())
+	}
+
+	var sa syscall.Sockaddr
+
+	fd := int(args[0].(*object.Integer).Value)
+	address := args[1].(*object.String).Value
+
+	sockaddr, err := syscall.Getsockname(syscall.Handle(fd))
+	if err != nil {
+		return newError("ValueError: %s", err)
+	}
+
+	if _, ok := sockaddr.(*syscall.SockaddrInet4); ok {
+		addr, port, err := parseV4Address(address)
+		if err != nil {
+			return newError("ValueError: Invalid IPv4 address '%s': %s", address, err)
+		}
+		sa = &syscall.SockaddrInet4{Addr: addr, Port: port}
+	} else if _, ok := sockaddr.(*syscall.SockaddrInet6); ok {
+		addr, port, err := parseV6Address(address)
+		if err != nil {
+			return newError("ValueError: Invalid IPv6 address '%s': %s", address, err)
+		}
+		sa = &syscall.SockaddrInet6{Addr: addr, Port: port}
+	} else {
+		return newError("ValueError: Invalid socket type %T for bind '%s'", sockaddr, address)
+	}
+
+	if err = syscall.Connect(syscall.Handle(fd), sa); err != nil {
+		return newError("SocketError: %s", err)
+	}
+
+	return &object.Null{}
+}

builtins/listen.go

@@ -0,0 +1,27 @@
+package builtins
+
+import (
+	"monkey/object"
+	"monkey/typing"
+	"syscall"
+)
+
+// Listen ...
+func Listen(args ...object.Object) object.Object {
+	if err := typing.Check(
+		"listen", args,
+		typing.ExactArgs(2),
+		typing.WithTypes(object.INTEGER_OBJ, object.INTEGER_OBJ),
+	); err != nil {
+		return newError(err.Error())
+	}
+
+	fd := int(args[0].(*object.Integer).Value)
+	backlog := int(args[1].(*object.Integer).Value)
+
+	if err := syscall.Listen(syscall.Handle(fd), backlog); err != nil {
+		return newError("SocketError: %s", err)
+	}
+
+	return &object.Null{}
+}

builtins/socket.go

@@ -0,0 +1,65 @@
+package builtins
+
+import (
+	"monkey/object"
+	"monkey/typing"
+	"strings"
+	"syscall"
+)
+
+// Socket ...
+func Socket(args ...object.Object) object.Object {
+	if err := typing.Check(
+		"socket", args,
+		typing.ExactArgs(1),
+		typing.WithTypes(object.STRING_OBJ),
+	); err != nil {
+		return newError(err.Error())
+	}
+
+	var (
+		domain int
+		typ    int
+		proto  int
+	)
+
+	arg := args[0].(*object.String).Value
+
+	switch strings.ToLower(arg) {
+	case "unix":
+		domain = syscall.AF_UNIX
+		typ = syscall.SOCK_STREAM
+		proto = 0
+	case "tcp4":
+		domain = syscall.AF_INET
+		typ = syscall.SOCK_STREAM
+		proto = syscall.IPPROTO_TCP
+	case "tcp6":
+		domain = syscall.AF_INET6
+		typ = syscall.SOCK_STREAM
+		proto = syscall.IPPROTO_TCP
+	case "udp4":
+		domain = syscall.AF_INET
+		typ = syscall.SOCK_DGRAM
+		proto = syscall.IPPROTO_UDP
+	case "udp6":
+		domain = syscall.AF_INET6
+		typ = syscall.SOCK_DGRAM
+		proto = syscall.IPPROTO_UDP
+	default:
+		return newError("ValueError: invalid socket type '%s'", arg)
+	}
+
+	fd, err := syscall.Socket(domain, typ, proto)
+	if err != nil {
+		return newError("SocketError: %s", err)
+	}
+
+	if domain == syscall.AF_INET || domain == syscall.AF_INET6 {
+		if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
+			return newError("SocketError: cannot enable SO_REUSEADDR: %s", err)
+		}
+	}
+
+	return &object.Integer{Value: int64(fd)}
+}

builtins/socket_utils.go

@@ -0,0 +1,68 @@
+package builtins
+
+import (
+	"fmt"
+	"net"
+	"strconv"
+)
+
+func parseAddress(address string) (ip net.IP, port int, err error) {
+	var (
+		h string
+		p string
+		n int64
+	)
+
+	h, p, err = net.SplitHostPort(address)
+	if err != nil {
+		return
+	}
+
+	ip = net.ParseIP(h)
+	if ip == nil {
+		var addrs []string
+		addrs, err = net.LookupHost(address)
+		if err != nil {
+			err = fmt.Errorf("error resolving host '%s'", address)
+			return
+		}
+
+		if len(addrs) == 0 {
+			err = fmt.Errorf("host not found '%s'", address)
+			return
+		}
+
+		ip = net.ParseIP(addrs[0])
+		if ip == nil {
+			err = fmt.Errorf("invalid IP address '%s'", address)
+			return
+		}
+	}
+
+	n, err = strconv.ParseInt(p, 10, 16)
+	if err != nil {
+		return
+	}
+	port = int(n)
+	return
+}
+
+func parseV4Address(address string) (addr [4]byte, port int, err error) {
+	var ip net.IP
+	ip, port, err = parseAddress(address)
+	if err != nil {
+		return
+	}
+	copy(addr[:], ip.To4()[:4])
+	return
+}
+
+func parseV6Address(address string) (addr [16]byte, port int, err error) {
+	var ip net.IP
+	ip, port, err = parseAddress(address)
+	if err != nil {
+		return
+	}
+	copy(addr[:], ip.To16()[:16])
+	return
+}