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|
// Copyright 2018-present the CoreDHCP Authors. All rights reserved
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.
package server
import (
"errors"
"fmt"
"io"
"net"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"github.com/coredhcp/coredhcp/config"
"github.com/coredhcp/coredhcp/handler"
"github.com/coredhcp/coredhcp/logger"
"github.com/coredhcp/coredhcp/plugins"
"github.com/insomniacslk/dhcp/dhcpv4/server4"
"github.com/insomniacslk/dhcp/dhcpv6/server6"
)
var log = logger.GetLogger("server")
type listener6 struct {
*ipv6.PacketConn
net.Interface
handlers []handler.Handler6
}
type listener4 struct {
*ipv4.PacketConn
net.Interface
handlers []handler.Handler4
}
type listener interface {
io.Closer
}
// Servers contains state for a running server (with possibly multiple interfaces/listeners)
type Servers struct {
listeners []listener
errors chan error
}
func listen4(a *net.UDPAddr) (*listener4, error) {
var err error
l4 := listener4{}
udpConn, err := server4.NewIPv4UDPConn(a.Zone, a)
if err != nil {
return nil, err
}
l4.PacketConn = ipv4.NewPacketConn(udpConn)
var ifi *net.Interface
if a.Zone != "" {
ifi, err = net.InterfaceByName(a.Zone)
if err != nil {
return nil, fmt.Errorf("DHCPv4: Listen could not find interface %s: %v", a.Zone, err)
}
l4.Interface = *ifi
} else {
// When not bound to an interface, we need the information in each
// packet to know which interface it came on
err = l4.SetControlMessage(ipv4.FlagInterface, true)
if err != nil {
return nil, err
}
}
if a.IP.IsMulticast() {
err = l4.JoinGroup(ifi, a)
if err != nil {
return nil, err
}
}
return &l4, nil
}
func listen6(a *net.UDPAddr) (*listener6, error) {
l6 := listener6{}
udpconn, err := server6.NewIPv6UDPConn(a.Zone, a)
if err != nil {
return nil, err
}
l6.PacketConn = ipv6.NewPacketConn(udpconn)
var ifi *net.Interface
if a.Zone != "" {
ifi, err = net.InterfaceByName(a.Zone)
if err != nil {
return nil, fmt.Errorf("DHCPv4: Listen could not find interface %s: %v", a.Zone, err)
}
l6.Interface = *ifi
} else {
// When not bound to an interface, we need the information in each
// packet to know which interface it came on
err = l6.SetControlMessage(ipv6.FlagInterface, true)
if err != nil {
return nil, err
}
}
if a.IP.IsMulticast() {
err = l6.JoinGroup(ifi, a)
if err != nil {
return nil, err
}
}
return &l6, nil
}
// Start will start the server asynchronously. See `Wait` to wait until
// the execution ends.
func Start(config *config.Config) (*Servers, error) {
handlers4, handlers6, err := plugins.LoadPlugins(config)
if err != nil {
return nil, err
}
srv := Servers{
errors: make(chan error),
}
// listen
if config.Server6 != nil {
log.Println("Starting DHCPv6 server")
for _, addr := range config.Server6.Addresses {
var l6 *listener6
l6, err = listen6(&addr)
if err != nil {
goto cleanup
}
l6.handlers = handlers6
srv.listeners = append(srv.listeners, l6)
go func() {
srv.errors <- l6.Serve()
}()
}
}
if config.Server4 != nil {
log.Println("Starting DHCPv4 server")
for _, addr := range config.Server4.Addresses {
var l4 *listener4
l4, err = listen4(&addr)
if err != nil {
goto cleanup
}
l4.handlers = handlers4
srv.listeners = append(srv.listeners, l4)
go func() {
srv.errors <- l4.Serve()
}()
}
}
return &srv, nil
cleanup:
srv.Close()
return nil, err
}
// Wait waits until the end of the execution of the server.
func (s *Servers) Wait() error {
log.Debug("Waiting")
errs := make([]error, 1, len(s.listeners))
errs[0] = <-s.errors
s.Close()
// Wait for the other listeners to close
for i := 1; i < len(s.listeners); i++ {
errs = append(errs, <-s.errors)
}
return errors.Join(errs...)
}
// Close closes all listening connections
func (s *Servers) Close() {
for _, srv := range s.listeners {
if srv != nil {
srv.Close()
}
}
}
|
