Add network device driver model, netdev

This PR adds a network device driver model called netdev. There will be a companion PR for TinyGo drivers to update the netdev drivers and network examples. This PR covers the core "net" package.

An RFC for the work is here: #tinygo-org/drivers#487. Some things have changed from the RFC, but nothing major.

The "net" package is a partial port of Go's "net" package, version 1.19.3. The src/net/README file has details on what is modified from Go's "net" package.

Most "net" features are working as they would in normal Go. TCP/UDP/TLS protocol support is there. As well as HTTP client and server support. Standard Go network packages such as golang.org/x/net/websockets and Paho MQTT client work as-is. Other packages are likely to work as-is.

Testing results are here (https://docs.google.com/spreadsheets/d/e/2PACX-1vT0cCjBvwXf9HJf6aJV2Sw198F2ief02gmbMV0sQocKT4y4RpfKv3dh6Jyew8lQW64FouZ8GwA2yjxI/pubhtml?gid=1013173032&single=true).

loader/goroot.go

@@ -233,6 +233,7 @@ func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 		"":                      true,
 		"crypto/":               true,
 		"crypto/rand/":          false,
+		"crypto/tls/":           false,
 		"device/":               false,
 		"examples/":             false,
 		"internal/":             true,
@@ -242,6 +243,7 @@ func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 		"internal/task/":        false,
 		"machine/":              false,
 		"net/":                  true,
+		"net/http/":             false,
 		"os/":                   true,
 		"reflect/":              false,
 		"runtime/":              false,

src/crypto/tls/common.go

@@ -0,0 +1,12 @@
+// TINYGO: The following is copied and modified from Go 1.19.3 official implementation.
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+// ConnectionState records basic TLS details about the connection.
+type ConnectionState struct {
+	// TINYGO: empty; TLS connection offloaded to device
+}

src/crypto/tls/tls.go

@@ -0,0 +1,63 @@
+// TINYGO: The following is copied and modified from Go 1.19.3 official implementation.
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tls partially implements TLS 1.2, as specified in RFC 5246,
+// and TLS 1.3, as specified in RFC 8446.
+package tls
+
+// BUG(agl): The crypto/tls package only implements some countermeasures
+// against Lucky13 attacks on CBC-mode encryption, and only on SHA1
+// variants. See http://www.isg.rhul.ac.uk/tls/TLStiming.pdf and
+// https://www.imperialviolet.org/2013/02/04/luckythirteen.html.
+
+import (
+	"fmt"
+	"net"
+)
+
+// Client returns a new TLS client side connection
+// using conn as the underlying transport.
+// The config cannot be nil: users must set either ServerName or
+// InsecureSkipVerify in the config.
+func Client(conn net.Conn, config *Config) *net.TLSConn {
+	panic("tls.Client() not implemented")
+	return nil
+}
+
+// DialWithDialer connects to the given network address using dialer.Dial and
+// then initiates a TLS handshake, returning the resulting TLS connection. Any
+// timeout or deadline given in the dialer apply to connection and TLS
+// handshake as a whole.
+//
+// DialWithDialer interprets a nil configuration as equivalent to the zero
+// configuration; see the documentation of Config for the defaults.
+//
+// DialWithDialer uses context.Background internally; to specify the context,
+// use Dialer.DialContext with NetDialer set to the desired dialer.
+func DialWithDialer(dialer *net.Dialer, network, addr string, config *Config) (*net.TLSConn, error) {
+	switch network {
+	case "tcp", "tcp4":
+	default:
+		return nil, fmt.Errorf("Network %s not supported", network)
+	}
+
+	return net.DialTLS(addr)
+}
+
+// Dial connects to the given network address using net.Dial
+// and then initiates a TLS handshake, returning the resulting
+// TLS connection.
+// Dial interprets a nil configuration as equivalent to
+// the zero configuration; see the documentation of Config
+// for the defaults.
+func Dial(network, addr string, config *Config) (*net.TLSConn, error) {
+	return DialWithDialer(new(net.Dialer), network, addr, config)
+}
+
+// Config is a placeholder for future compatibility with
+// tls.Config.
+type Config struct {
+}

src/os/file_other.go

@@ -42,6 +42,14 @@ func NewFile(fd uintptr, name string) *File {
 	return &File{&file{handle: stdioFileHandle(fd), name: name}}
 }
 
+// Rename renames (moves) oldpath to newpath.
+// If newpath already exists and is not a directory, Rename replaces it.
+// OS-specific restrictions may apply when oldpath and newpath are in different directories.
+// If there is an error, it will be of type *LinkError.
+func Rename(oldpath, newpath string) error {
+	return ErrNotImplemented
+}
+
 // Read reads up to len(b) bytes from machine.Serial.
 // It returns the number of bytes read and any error encountered.
 func (f stdioFileHandle) Read(b []byte) (n int, err error) {

src/syscall/net.go

@@ -32,3 +32,22 @@ type Conn interface {
 	// SyscallConn returns a raw network connection.
 	SyscallConn() (RawConn, error)
 }
+
+const (
+	AF_INET       = 0x2
+	SOCK_STREAM   = 0x1
+	SOCK_DGRAM    = 0x2
+	SOL_SOCKET    = 0x1
+	SO_KEEPALIVE  = 0x9
+	SOL_TCP       = 0x6
+	TCP_KEEPINTVL = 0x5
+	IPPROTO_TCP   = 0x6
+	IPPROTO_UDP   = 0x11
+	F_SETFL       = 0x4
+
+	// TINYGO: Made up, not a real IP protocol number.  This is used to
+	// create a TLS socket on the device, assuming the device supports mbed
+	// TLS.
+
+	IPPROTO_TLS = 0xFE
+)

src/syscall/syscall_libc_darwin.go

@@ -53,7 +53,6 @@ const (
 	DT_UNKNOWN = 0x0
 	DT_WHT     = 0xe
 	F_GETFL    = 0x3
-	F_SETFL    = 0x4
 	O_NONBLOCK = 0x4
 )
 

src/syscall/syscall_libc_wasi.go

@@ -102,7 +102,6 @@ const (
 
 	// ../../lib/wasi-libc/expected/wasm32-wasi/predefined-macros.txt
 	F_GETFL = 3
-	F_SETFL = 4
 )
 
 // These values are needed as a stub until Go supports WASI as a full target.