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Cleanup the PR a bit 

Remove code and simplify some functions. Documentation is still on the
todo.
Also don't export any of these functions and/or types.
This commit is contained in:
Miek Gieben 2014-07-09 21:02:21 +01:00
parent e4d735493c
commit d161b9087e
4 changed files with 36 additions and 47 deletions
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24
server.go
View File

@ -44,10 +44,10 @@ type response struct {
tsigTimersOnly bool
tsigRequestMAC string
tsigSecret map[string]string // the tsig secrets
udp *UDPConn // i/o connection if UDP was used
udpSession *UDPSession
tcp *net.TCPConn // i/o connection if TCP was used
remoteAddr net.Addr // address of the client
udp *net.UDPConn // i/o connection if UDP was used
tcp *net.TCPConn // i/o connection if TCP was used
udpSession *sessionUDP // oob data to get egress interface right
remoteAddr net.Addr // address of the client
}
// ServeMux is an DNS request multiplexer. It matches the
@ -244,12 +244,10 @@ func (srv *Server) ListenAndServe() error {
return e
}
ll, e := NewUDPConn(l)
if e != nil {
if e := setUDPSocketOptions(l); e != nil {
return e
}
return srv.serveUDP(ll)
return srv.serveUDP(l)
}
return &Error{err: "bad network"}
}
@ -282,7 +280,7 @@ func (srv *Server) serveTCP(l *net.TCPListener) error {
// serveUDP starts a UDP listener for the server.
// Each request is handled in a seperate goroutine.
func (srv *Server) serveUDP(l *UDPConn) error {
func (srv *Server) serveUDP(l *net.UDPConn) error {
defer l.Close()
handler := srv.Handler
if handler == nil {
@ -304,7 +302,7 @@ func (srv *Server) serveUDP(l *UDPConn) error {
}
// Serve a new connection.
func (srv *Server) serve(a net.Addr, h Handler, m []byte, u *UDPConn, s *UDPSession, t *net.TCPConn) {
func (srv *Server) serve(a net.Addr, h Handler, m []byte, u *net.UDPConn, s *sessionUDP, t *net.TCPConn) {
w := &response{tsigSecret: srv.TsigSecret, udp: u, tcp: t, remoteAddr: a, udpSession: s}
q := 0
Redo:
@ -392,9 +390,9 @@ func (srv *Server) readTCP(conn *net.TCPConn, timeout time.Duration) ([]byte, er
return m, nil
}
func (srv *Server) readUDP(conn *UDPConn, timeout time.Duration) ([]byte, *UDPSession, error) {
func (srv *Server) readUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *sessionUDP, error) {
m := make([]byte, srv.UDPSize)
n, s, e := conn.ReadFromSessionUDP(m)
n, s, e := readFromSessionUDP(conn, m)
if e != nil || n == 0 {
if e != nil {
return nil, nil, e
@ -430,7 +428,7 @@ func (w *response) WriteMsg(m *Msg) (err error) {
func (w *response) Write(m []byte) (int, error) {
switch {
case w.udp != nil:
n, err := w.udp.WriteToSessionUDP(m, w.udpSession)
n, err := writeToSessionUDP(w.udp, m, w.udpSession)
return n, err
case w.tcp != nil:
lm := len(m)

41
udp.go
View File

@ -9,28 +9,19 @@ import (
"syscall"
)
type UDPSession struct {
type sessionUDP struct {
raddr *net.UDPAddr
context []byte
}
func (session *UDPSession) RemoteAddr() net.Addr {
return session.raddr
}
func (s *sessionUDP) RemoteAddr() net.Addr { return s.raddr }
// UDPConn wrap a net.UDPConn with dns.UDPConn struct
type UDPConn struct {
*net.UDPConn
}
// NewUDPConn return a new UDPConn.
// Initialize the underlying net.UDPConn for supporting "sessions"
// Sessions solve https://github.com/miekg/dns/issues/95
func NewUDPConn(conn *net.UDPConn) (*UDPConn, error) {
// this function is implemented on a per platform basis. See udp_*.go for more details
// setUDPSocketOptions sets the UDP socket options.
// This function is implemented on a per platform basis. See udp_*.go for more details
func setUDPSocketOptions(conn *net.UDPConn) error {
file, err := conn.File()
if err != nil {
return nil,err
return err
}
sa, err := syscall.Getsockname(int(file.Fd()))
@ -39,34 +30,34 @@ func NewUDPConn(conn *net.UDPConn) (*UDPConn, error) {
// dual stack. See http://stackoverflow.com/questions/1618240/how-to-support-both-ipv4-and-ipv6-connections
v6only, err := syscall.GetsockoptInt(int(file.Fd()), syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY)
if err != nil {
return nil, err
return err
}
SetUDPSocketOptions6(conn)
setUDPSocketOptions6(conn)
if v6only == 0 {
SetUDPSocketOptions4(conn)
setUDPSocketOptions4(conn)
}
case *syscall.SockaddrInet4:
SetUDPSocketOptions4(conn)
setUDPSocketOptions4(conn)
}
return &UDPConn{conn}, nil
return nil
}
// ReadFromSessionUDP ... Just like net.UDPConn.ReadFrom(), but returns a session object instead of net.UDPAddr
// readFromSessionUDP ... Just like net.UDPConn.ReadFrom(), but returns a session object instead of net.UDPAddr
// (RemoteAddr() is available from the UDPSession object)
func (conn *UDPConn) ReadFromSessionUDP(b []byte) (int, *UDPSession, error) {
func readFromSessionUDP(conn *net.UDPConn, b []byte) (int, *sessionUDP, error) {
oob := make([]byte, 40)
n, oobn, _, raddr, err := conn.ReadMsgUDP(b, oob)
if err != nil {
return n, nil, err
}
session := &UDPSession{raddr, oob[:oobn]}
session := &sessionUDP{raddr, oob[:oobn]}
return n, session, err
}
// WriteToSessionUDP Just like net.UDPConn.WritetTo(), but uses a session object instead of net.Addr
func (conn *UDPConn) WriteToSessionUDP(b []byte, session *UDPSession) (int, error) {
// writeToSessionUDP Just like net.UDPConn.WritetTo(), but uses a session object instead of net.Addr
func writeToSessionUDP(conn *net.UDPConn, b []byte, session *sessionUDP) (int, error) {
n, _, err := conn.WriteMsgUDP(b, session.context, session.raddr)
return n, err
}

14
udp_linux.go
View File

@ -10,7 +10,7 @@ package dns
// * http://stackoverflow.com/questions/3062205/setting-the-source-ip-for-a-udp-socket and
// * http://blog.powerdns.com/2012/10/08/on-binding-datagram-udp-sockets-to-the-any-addresses/
//
// Why do we need this: When listening on 0.0.0.0 with UDP so kernel decides what is the outoging
// Why do we need this: When listening on 0.0.0.0 with UDP so kernel decides what is the outgoing
// interface, this might not always be the correct one. This code will make sure the egress
// packet's interface matched the ingress' one.
@ -19,9 +19,9 @@ import (
"syscall"
)
// SetUDPSocketOptions4 prepares the v4 socket for sessions.
func SetUDPSocketOptions4(conn *net.UDPConn) error {
// We got the .File() in NewUDPConn, this this will work
// setUDPSocketOptions4 prepares the v4 socket for sessions.
func setUDPSocketOptions4(conn *net.UDPConn) error {
// We got the .File() in NewUDPConn, this this will work.
file, _ := conn.File()
err := syscall.SetsockoptInt(int(file.Fd()), syscall.IPPROTO_IP, syscall.IP_PKTINFO, 1)
if err != nil {
@ -30,9 +30,9 @@ func SetUDPSocketOptions4(conn *net.UDPConn) error {
return nil
}
// SetUDPSocketOptions6 prepares the v6 socket for sessions.
func SetUDPSocketOptions6(conn *net.UDPConn) error {
// We got the .File() in NewUDPConn, this this will work
// setUDPSocketOptions6 prepares the v6 socket for sessions.
func setUDPSocketOptions6(conn *net.UDPConn) error {
// We got the .File() in NewUDPConn, this this will work.
file, _ := conn.File()
err := syscall.SetsockoptInt(int(file.Fd()), syscall.IPPROTO_IPV6, syscall.IPV6_RECVPKTINFO, 1)
if err != nil {

4
udp_other.go
View File

@ -12,5 +12,5 @@ import (
// These actually do nothing. See udp_linux.go for an example of how to implement this.
func SetUDPSocketOptions4(conn *net.UDPConn) error { return nil }
func SetUDPSocketOptions6(conn *net.UDPConn) error { return nil }
func setUDPSocketOptions4(conn *net.UDPConn) error { return nil }
func setUDPSocketOptions6(conn *net.UDPConn) error { return nil }