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Make draw/x11 treat $DISPLAY the same way x-go-bindings does.

This ought to make draw/x11 work on a Mac.

R=rsc
CC=golang-dev
https://golang.org/cl/1265042
This commit is contained in:
Nigel Tao 2010-05-24 11:44:09 -07:00
parent eadebba36f
commit 2d8aee45b8
2 changed files with 97 additions and 44 deletions

View File

@ -10,21 +10,6 @@ import (
"os"
)
// getDisplay reads the DISPLAY environment variable, and returns the "12" in ":12.0".
func getDisplay() string {
d := os.Getenv("DISPLAY")
if len(d) < 1 || d[0] != ':' {
return ""
}
i := 1
for ; i < len(d); i++ {
if d[i] < '0' || d[i] > '9' {
break
}
}
return d[1:i]
}
// readU16BE reads a big-endian uint16 from r, using b as a scratch buffer.
func readU16BE(r io.Reader, b []byte) (uint16, os.Error) {
_, err := io.ReadFull(r, b[0:2])
@ -50,9 +35,12 @@ func readStr(r io.Reader, b []byte) (string, os.Error) {
return string(b[0:n]), nil
}
// readAuth reads the X authority file and returns the name/data pair for the DISPLAY.
// b is a scratch buffer to use, and should be at least 256 bytes long (i.e. it should be able to hold a hostname).
func readAuth(b []byte) (name, data string, err os.Error) {
// readAuth reads the X authority file and returns the name/data pair for the display.
// displayStr is the "12" out of a $DISPLAY like ":12.0".
func readAuth(displayStr string) (name, data string, err os.Error) {
// b is a scratch buffer to use and should be at least 256 bytes long
// (i.e. it should be able to hold a hostname).
var b [256]byte
// As per /usr/include/X11/Xauth.h.
const familyLocal = 256
@ -76,7 +64,6 @@ func readAuth(b []byte) (name, data string, err os.Error) {
if err != nil {
return
}
display := getDisplay()
for {
family, err := readU16BE(br, b[0:2])
if err != nil {
@ -98,7 +85,7 @@ func readAuth(b []byte) (name, data string, err os.Error) {
if err != nil {
return
}
if family == familyLocal && addr == hostname && disp == display {
if family == familyLocal && addr == hostname && disp == displayStr {
return name0, data0, nil
}
}

View File

@ -17,6 +17,8 @@ import (
"io"
"net"
"os"
"strconv"
"strings"
)
type resID uint32 // X resource IDs.
@ -197,9 +199,65 @@ func (c *conn) pumper() {
// TODO(nigeltao): Should we explicitly close our kbd/mouse/resize/quit chans?
}
// Authenticate ourselves with the X server.
func (c *conn) authenticate() os.Error {
key, value, err := readAuth(c.buf[0:])
// connect connects to the X server given by the full X11 display name (e.g.
// ":12.0") and returns the connection as well as the portion of the full name
// that is the display number (e.g. "12").
// Examples:
// connect(":1") // calls net.Dial("unix", "", "/tmp/.X11-unix/X1"), displayStr="1"
// connect("/tmp/launch-123/:0") // calls net.Dial("unix", "", "/tmp/launch-123/:0"), displayStr="0"
// connect("hostname:2.1") // calls net.Dial("tcp", "", "hostname:6002"), displayStr="2"
// connect("tcp/hostname:1.0") // calls net.Dial("tcp", "", "hostname:6001"), displayStr="1"
func connect(display string) (conn net.Conn, displayStr string, err os.Error) {
colonIdx := strings.LastIndex(display, ":")
if colonIdx < 0 {
return nil, "", os.NewError("bad display: " + display)
}
// Parse the section before the colon.
var protocol, host, socket string
if display[0] == '/' {
socket = display[0:colonIdx]
} else {
if i := strings.LastIndex(display, "/"); i < 0 {
// The default protocol is TCP.
protocol = "tcp"
host = display[0:colonIdx]
} else {
protocol = display[0:i]
host = display[i+1 : colonIdx]
}
}
// Parse the section after the colon.
after := display[colonIdx+1:]
if after == "" {
return nil, "", os.NewError("bad display: " + display)
}
if i := strings.LastIndex(after, "."); i < 0 {
displayStr = after
} else {
displayStr = after[0:i]
}
displayInt, err := strconv.Atoi(displayStr)
if err != nil || displayInt < 0 {
return nil, "", os.NewError("bad display: " + display)
}
// Make the connection.
if socket != "" {
conn, err = net.Dial("unix", "", socket+":"+displayStr)
} else if host != "" {
conn, err = net.Dial(protocol, "", host+":"+strconv.Itoa(6000+displayInt))
} else {
conn, err = net.Dial("unix", "", "/tmp/.X11-unix/X"+displayStr)
}
if err != nil {
return nil, "", os.NewError("cannot connect to " + display + ": " + err.String())
}
return
}
// authenticate authenticates ourselves with the X server.
// displayStr is the "12" out of ":12.0".
func authenticate(w *bufio.Writer, displayStr string) os.Error {
key, value, err := readAuth(displayStr)
if err != nil {
return err
}
@ -210,31 +268,31 @@ func (c *conn) authenticate() os.Error {
// 0x006c means little-endian. 0x000b, 0x0000 means X major version 11, minor version 0.
// 0x0012 and 0x0010 means the auth key and value have lenths 18 and 16.
// The final 0x0000 is padding, so that the string length is a multiple of 4.
_, err = io.WriteString(c.w, "\x6c\x00\x0b\x00\x00\x00\x12\x00\x10\x00\x00\x00")
_, err = io.WriteString(w, "\x6c\x00\x0b\x00\x00\x00\x12\x00\x10\x00\x00\x00")
if err != nil {
return err
}
_, err = io.WriteString(c.w, key)
_, err = io.WriteString(w, key)
if err != nil {
return err
}
// Again, the 0x0000 is padding.
_, err = io.WriteString(c.w, "\x00\x00")
_, err = io.WriteString(w, "\x00\x00")
if err != nil {
return err
}
_, err = io.WriteString(c.w, value)
_, err = io.WriteString(w, value)
if err != nil {
return err
}
err = c.w.Flush()
err = w.Flush()
if err != nil {
return err
}
return nil
}
// Reads a uint8 from r, using b as a scratch buffer.
// readU8 reads a uint8 from r, using b as a scratch buffer.
func readU8(r io.Reader, b []byte) (uint8, os.Error) {
_, err := io.ReadFull(r, b[0:1])
if err != nil {
@ -243,7 +301,7 @@ func readU8(r io.Reader, b []byte) (uint8, os.Error) {
return uint8(b[0]), nil
}
// Reads a little-endian uint16 from r, using b as a scratch buffer.
// readU16LE reads a little-endian uint16 from r, using b as a scratch buffer.
func readU16LE(r io.Reader, b []byte) (uint16, os.Error) {
_, err := io.ReadFull(r, b[0:2])
if err != nil {
@ -252,7 +310,7 @@ func readU16LE(r io.Reader, b []byte) (uint16, os.Error) {
return uint16(b[0]) | uint16(b[1])<<8, nil
}
// Reads a little-endian uint32 from r, using b as a scratch buffer.
// readU32LE reads a little-endian uint32 from r, using b as a scratch buffer.
func readU32LE(r io.Reader, b []byte) (uint32, os.Error) {
_, err := io.ReadFull(r, b[0:4])
if err != nil {
@ -261,7 +319,7 @@ func readU32LE(r io.Reader, b []byte) (uint32, os.Error) {
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24, nil
}
// Sets b[0:4] to be the big-endian representation of u.
// setU32LE sets b[0:4] to be the big-endian representation of u.
func setU32LE(b []byte, u uint32) {
b[0] = byte((u >> 0) & 0xff)
b[1] = byte((u >> 8) & 0xff)
@ -269,7 +327,7 @@ func setU32LE(b []byte, u uint32) {
b[3] = byte((u >> 24) & 0xff)
}
// Check that we have an agreeable X pixmap Format.
// checkPixmapFormats checks that we have an agreeable X pixmap Format.
func checkPixmapFormats(r io.Reader, b []byte, n int) (agree bool, err os.Error) {
for i := 0; i < n; i++ {
_, err = io.ReadFull(r, b[0:8])
@ -284,7 +342,7 @@ func checkPixmapFormats(r io.Reader, b []byte, n int) (agree bool, err os.Error)
return
}
// Check that we have an agreeable X Depth (i.e. one that has an agreeable X VisualType).
// checkDepths checks that we have an agreeable X Depth (i.e. one that has an agreeable X VisualType).
func checkDepths(r io.Reader, b []byte, n int, visual uint32) (agree bool, err os.Error) {
for i := 0; i < n; i++ {
depth, err := readU16LE(r, b)
@ -321,7 +379,7 @@ func checkDepths(r io.Reader, b []byte, n int, visual uint32) (agree bool, err o
return
}
// Check that we have an agreeable X Screen.
// checkScreens checks that we have an agreeable X Screen.
func checkScreens(r io.Reader, b []byte, n int) (root, visual uint32, err os.Error) {
for i := 0; i < n; i++ {
root0, err := readU32LE(r, b)
@ -356,7 +414,8 @@ func checkScreens(r io.Reader, b []byte, n int) (root, visual uint32, err os.Err
return
}
// Perform the protocol handshake with the X server, and ensure that the server provides a compatible Screen, Depth, etcetera.
// handshake performs the protocol handshake with the X server, and ensures
// that the server provides a compatible Screen, Depth, etc.
func (c *conn) handshake() os.Error {
_, err := io.ReadFull(c.r, c.buf[0:8])
if err != nil {
@ -447,21 +506,28 @@ func (c *conn) handshake() os.Error {
return nil
}
// Returns a new draw.Context, backed by a newly created and mapped X11 window.
// NewWindow calls NewWindowDisplay with $DISPLAY.
func NewWindow() (draw.Context, os.Error) {
display := getDisplay()
display := os.Getenv("DISPLAY")
if len(display) == 0 {
return nil, os.NewError("unsupported DISPLAY")
return nil, os.NewError("$DISPLAY not set")
}
s, err := net.Dial("unix", "", "/tmp/.X11-unix/X"+display)
return NewWindowDisplay(display)
}
// NewWindowDisplay returns a new draw.Context, backed by a newly created and
// mapped X11 window. The X server to connect to is specified by the display
// string, such as ":1".
func NewWindowDisplay(display string) (draw.Context, os.Error) {
socket, displayStr, err := connect(display)
if err != nil {
return nil, err
}
c := new(conn)
c.c = s
c.r = bufio.NewReader(s)
c.w = bufio.NewWriter(s)
err = c.authenticate()
c.c = socket
c.r = bufio.NewReader(socket)
c.w = bufio.NewWriter(socket)
err = authenticate(c.w, displayStr)
if err != nil {
return nil, err
}