it compiles + more tweaks

This commit is contained in:
Miek Gieben 2011-04-03 11:49:23 +02:00
parent c7dbb1edc2
commit 064bfe4f2e
1 changed files with 247 additions and 194 deletions

441
server.go
View File

@ -7,46 +7,48 @@
package dns
import (
// "io"
"io"
"os"
"net"
)
type Handler interface {
ServeDNS(w ResponseWriter, r *Msg)
ServeDNS(w ResponseWriter, r *Msg)
}
// TODO(mg): fit axfr responses in here too
// A ResponseWriter interface is used by an DNS handler to
// construct an DNS response.
type ResponseWriter interface {
// RemoteAddr returns the address of the client that sent the current request
RemoteAddr() string
// RemoteAddr returns the address of the client that sent the current request
RemoteAddr() string
Write([]byte) (int, os.Error)
Write([]byte) (int, os.Error)
// IP based ACL mapping. The contains the string representation
// of the IP address and a boolean saying it may connect (true) or not.
Acl() map[string]bool
// IP based ACL mapping. The contains the string representation
// of the IP address and a boolean saying it may connect (true) or not.
Acl() map[string]bool
// Tsig secrets. Its a mapping of key names to secrets.
Tsig() map[string]string
// Tsig secrets. Its a mapping of key names to secrets.
Tsig() map[string]string
}
type conn struct {
remoteAddr net.Addr // address of remote side (sans port)
port int // port of the remote side
handler Handler // request handler
request []byte // bytes read
_UDP *net.UDPConn // i/o connection if UDP was used
_TCP *net.TCPConn // i/o connection if TCP was used
hijacked bool // connection has been hijacked by hander TODO(mg)
remoteAddr net.Addr // address of remote side (sans port)
port int // port of the remote side, needed TODO(mg)
handler Handler // request handler
request []byte // bytes read
_UDP *net.UDPConn // i/o connection if UDP was used
_TCP *net.TCPConn // i/o connection if TCP was used
hijacked bool // connection has been hijacked by hander TODO(mg)
tsig map[string]string // tsig secrets
acl map[string]bool // ip acl list
}
type response struct {
conn *conn
req *Msg
xfr bool // {i/a}xfr was requested
conn *conn
req *Msg
xfr bool // {i/a}xfr was requested
}
// ServeMux is an DNS request multiplexer. It matches the
@ -54,7 +56,7 @@ type response struct {
// registered patterns add calls the handler for the pattern
// that most closely matches the zone name.
type ServeMux struct {
m map[string]Handler
m map[string]Handler
}
// NewServeMux allocates and returns a new ServeMux.
@ -71,7 +73,7 @@ type HandlerFunc func(ResponseWriter, *Msg)
// ServerDNS calls f(w, reg)
func (f HandlerFunc) ServeDNS(w ResponseWriter, r *Msg) {
f(w, r)
f(w, r)
}
// Helper handlers
@ -100,8 +102,8 @@ func HandleUDP(l *net.UDPConn, f func(*Conn, *Msg)) os.Error {
m = m[:n]
d := new(Conn)
// Use the remote addr as we got from ReadFromUDP
d.SetUDPConn(l, addr)
// Use the remote addr as we got from ReadFromUDP
d.SetUDPConn(l, addr)
msg := new(Msg)
if !msg.Unpack(m) {
@ -123,7 +125,7 @@ func HandleTCP(l *net.TCPListener, f func(*Conn, *Msg)) os.Error {
return e
}
d := new(Conn)
d.SetTCPConn(c, nil)
d.SetTCPConn(c, nil)
msg := new(Msg)
err := d.ReadMsg(msg)
@ -138,53 +140,53 @@ func HandleTCP(l *net.TCPListener, f func(*Conn, *Msg)) os.Error {
}
func ListenAndServe(addr string, network string, handler Handler) os.Error {
server := &Server{Addr: addr, Network: network, Handler: handler}
return server.ListenAndServe()
server := &Server{Addr: addr, Network: network, Handler: handler}
return server.ListenAndServe()
}
func zoneMatch(pattern, zone string) bool {
if len(pattern) == 0 {
return false
}
n := len(pattern)
return zone[:n] == pattern
if len(pattern) == 0 {
return false
}
n := len(pattern)
return zone[:n] == pattern
}
func (mux *ServeMux) match(zone string) Handler {
var h Handler
var n = 0
for k, v := range mux.m {
if !zoneMatch(k, zone) {
continue
}
if h == nil || len(k) > n {
n = len(k)
h = v
}
}
return h
var h Handler
var n = 0
for k, v := range mux.m {
if !zoneMatch(k, zone) {
continue
}
if h == nil || len(k) > n {
n = len(k)
h = v
}
}
return h
}
func (mux *ServeMux) Handle(pattern string, handler Handler) {
if pattern == "" {
panic("dns: invalid pattern " + pattern)
}
mux.m[pattern] = handler
if pattern == "" {
panic("dns: invalid pattern " + pattern)
}
mux.m[pattern] = handler
}
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
mux.Handle(pattern, HandlerFunc(handler))
mux.Handle(pattern, HandlerFunc(handler))
}
// ServeDNS dispatches the request to the handler whose
// pattern most closely matches the request message.
func (mux *ServeMux) ServeDNS(w ResponseWriter, request *Msg) {
h := mux.match(request.Question[0].Name)
if h == nil {
// h = NotFoundHandler()
}
h.ServeDNS(w, request)
h := mux.match(request.Question[0].Name)
if h == nil {
// h = NotFoundHandler()
}
h.ServeDNS(w, request)
}
// Handle register the handler the given pattern
@ -193,7 +195,7 @@ func (mux *ServeMux) ServeDNS(w ResponseWriter, request *Msg) {
func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
func HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
DefaultServeMux.HandleFunc(pattern, handler)
DefaultServeMux.HandleFunc(pattern, handler)
}
// Serve accepts incoming DNS request on the TCP listener l,
@ -201,8 +203,8 @@ func HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
// read requests and then call handler to reply to them.
// Handler is typically nil, in which case the DefaultServeMux is used.
func ServeTCP(l *net.TCPListener, handler Handler) os.Error {
srv := &Server{Handler: handler, Network: "tcp"}
return srv.ServeTCP(l)
srv := &Server{Handler: handler, Network: "tcp"}
return srv.ServeTCP(l)
}
// Serve accepts incoming DNS request on the UDP Conn l,
@ -210,171 +212,222 @@ func ServeTCP(l *net.TCPListener, handler Handler) os.Error {
// read requests and then call handler to reply to them.
// Handler is typically nil, in which case the DefaultServeMux is used.
func ServeUDP(l *net.UDPConn, handler Handler) os.Error {
srv := &Server{Handler: handler, Network: "udp"}
return srv.ServeUDP(l)
srv := &Server{Handler: handler, Network: "udp"}
return srv.ServeUDP(l)
}
// A Server defines parameters for running an HTTP server.
type Server struct {
Addr string // address to listen on, ":dns" if empty
Network string // If "tcp" it will invoke a TCP listener, otherwise an UDP one
Handler Handler // handler to invoke, http.DefaultServeMux if nil
ReadTimeout int64 // the net.Conn.SetReadTimeout value for new connections
WriteTimeout int64 // the net.Conn.SetWriteTimeout value for new connections
Addr string // address to listen on, ":dns" if empty
Network string // If "tcp" it will invoke a TCP listener, otherwise an UDP one
Handler Handler // handler to invoke, http.DefaultServeMux if nil
ReadTimeout int64 // the net.Conn.SetReadTimeout value for new connections
WriteTimeout int64 // the net.Conn.SetWriteTimeout value for new connections
}
// Fixes for udp/tcp
func (srv *Server) ListenAndServe() os.Error {
addr := srv.Addr
if addr == "" {
addr = ":domain"
}
switch srv.Network {
case "tcp":
a, e := net.ResolveTCPAddr(addr)
if e != nil {
return e
}
l, e := net.ListenTCP("tcp", a)
if e != nil {
return e
}
return srv.ServeTCP(l)
case "udp":
a, e := net.ResolveUDPAddr(addr)
if e != nil {
return e
}
l, e := net.ListenUDP("udp", a)
if e != nil {
return e
}
return srv.ServeUDP(l)
}
return nil // os.Error with wrong network
addr := srv.Addr
if addr == "" {
addr = ":domain"
}
switch srv.Network {
case "tcp":
a, e := net.ResolveTCPAddr(addr)
if e != nil {
return e
}
l, e := net.ListenTCP("tcp", a)
if e != nil {
return e
}
return srv.ServeTCP(l)
case "udp":
a, e := net.ResolveUDPAddr(addr)
if e != nil {
return e
}
l, e := net.ListenUDP("udp", a)
if e != nil {
return e
}
return srv.ServeUDP(l)
}
return nil // os.Error with wrong network
}
func (srv *Server) ServeTCP(l *net.TCPListener) os.Error {
defer l.Close()
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
}
forever:
for {
rw, e := l.AcceptTCP()
if e != nil {
return e
}
if srv.ReadTimeout != 0 {
rw.SetReadTimeout(srv.ReadTimeout)
}
if srv.WriteTimeout != 0 {
rw.SetWriteTimeout(srv.WriteTimeout)
}
l := make([]byte, 2)
n, err := rw.Read(l)
if err != nil || n != 2 {
continue
}
length, _ := unpackUint16(l, 0)
if length == 0 {
continue
}
m := make([]byte, int(length))
n, err = rw.Read(m[:int(length)])
if err != nil {
continue
}
i := n
for i < int(length) {
j, err := rw.Read(m[i:int(length)])
if err != nil {
continue forever
}
i += j
}
n = i
d, err := newConn(rw, nil, rw.RemoteAddr(), m, handler)
if err != nil {
continue
}
go d.serve()
}
panic("not reached")
defer l.Close()
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
}
forever:
for {
rw, e := l.AcceptTCP()
if e != nil {
return e
}
if srv.ReadTimeout != 0 {
rw.SetReadTimeout(srv.ReadTimeout)
}
if srv.WriteTimeout != 0 {
rw.SetWriteTimeout(srv.WriteTimeout)
}
l := make([]byte, 2)
n, err := rw.Read(l)
if err != nil || n != 2 {
continue
}
length, _ := unpackUint16(l, 0)
if length == 0 {
continue
}
m := make([]byte, int(length))
n, err = rw.Read(m[:int(length)])
if err != nil {
continue
}
i := n
for i < int(length) {
j, err := rw.Read(m[i:int(length)])
if err != nil {
continue forever
}
i += j
}
n = i
d, err := newConn(rw, nil, rw.RemoteAddr(), m, handler)
if err != nil {
continue
}
go d.serve()
}
panic("not reached")
}
func (srv *Server) ServeUDP(l *net.UDPConn) os.Error {
defer l.Close()
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
}
for {
m := make([]byte, DefaultMsgSize)
n, a, e := l.ReadFromUDP(m)
if e != nil {
return e
}
m = m[:n]
defer l.Close()
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
}
for {
m := make([]byte, DefaultMsgSize)
n, a, e := l.ReadFromUDP(m)
if e != nil {
return e
}
m = m[:n]
if srv.ReadTimeout != 0 {
l.SetReadTimeout(srv.ReadTimeout)
}
if srv.WriteTimeout != 0 {
l.SetWriteTimeout(srv.WriteTimeout)
}
d, err := newConn(nil, l, a, m, handler)
if err != nil {
continue
}
go d.serve()
}
panic("not reached")
if srv.ReadTimeout != 0 {
l.SetReadTimeout(srv.ReadTimeout)
}
if srv.WriteTimeout != 0 {
l.SetWriteTimeout(srv.WriteTimeout)
}
d, err := newConn(nil, l, a, m, handler)
if err != nil {
continue
}
go d.serve()
}
panic("not reached")
}
func newConn(t *net.TCPConn, u *net.UDPConn, a net.Addr, buf []byte, handler Handler) (c *conn, err os.Error) {
c = new(conn)
c.handler = handler
c._TCP = t
c._UDP = u
c.remoteAddr = a
c.request = buf
if t != nil {
c.port = a.(*net.TCPAddr).Port
}
if u != nil {
c.port = a.(*net.UDPAddr).Port
}
return c, err
c = new(conn)
c.handler = handler
c._TCP = t
c._UDP = u
c.remoteAddr = a
c.request = buf
if t != nil {
c.port = a.(*net.TCPAddr).Port
}
if u != nil {
c.port = a.(*net.UDPAddr).Port
}
return c, err
}
// Close the connection.
func (c *conn) close() {
switch {
case c._UDP != nil:
c._UDP.Close()
c._UDP = nil
case c._TCP != nil:
c._TCP.Close()
c._TCP = nil
}
switch {
case c._UDP != nil:
c._UDP.Close()
c._UDP = nil
case c._TCP != nil:
c._TCP.Close()
c._TCP = nil
}
}
// Serve a new connection.
func (c *conn) serve() {
// c.ReadRequest
// c.Handler.ServeDNS(w, w.req) // this does the writing
// Request has been read in ServeUDP or ServeTCP
w := new(response)
w.conn = c
w.xfr = false
req := new(Msg)
if !req.Unpack(c.request) {
return
}
c.handler.ServeDNS(w, w.req) // this does the writing back to the client
if c.hijacked {
return
}
c.close()
}
func (c *conn) readRequest() (w *response, err os.Error) {
w = new(response)
return w, nil
func (w *response) Write(data []byte) (n int, err os.Error) {
switch {
case w.conn._UDP != nil:
n, err = w.conn._UDP.WriteTo(data, w.conn.remoteAddr)
if err != nil {
return 0, err
}
case w.conn._TCP != nil:
// TODO(mg) len(data) > 64K
l := make([]byte, 2)
l[0], l[1] = packUint16(uint16(len(data)))
n, err = w.conn._TCP.Write(data)
if err != nil {
return n, err
}
if n != 2 {
return n, io.ErrShortWrite
}
n, err = w.conn._TCP.Write(data)
if err != nil {
return n, err
}
i := n
if i < len(data) {
j, err := w.conn._TCP.Write(data[i:len(data)])
if err != nil {
return i, err
}
i += j
}
n = i
}
return n, nil
}
// Acl implements the ResponseWriter.Acl
func (w *response) Acl() map[string]bool {
return w.conn.acl
}
// Tsig implements the ResponseWriter.Tsig
func (w *response) Tsig() map[string]string {
return w.conn.tsig
}
// RemoteAddr implements the ResponseWriter.RemoteAddr method
func (w *response) RemoteAddr() string { return w.conn.remoteAddr.String() }