/
server.go
97 lines (87 loc) · 2.25 KB
/
server.go
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// Package dhcpd contains snippets from MIT-licensed coredhcp project at
// https://github.com/coredhcp/coredhcp
package dhcpd
import (
"github.com/DSpeichert/netbootd/store"
"github.com/insomniacslk/dhcp/dhcpv4/server4"
"github.com/rs/zerolog"
"github.com/rs/zerolog/log"
"golang.org/x/net/ipv4"
"net"
)
type Server struct {
UdpConn *net.UDPConn
*ipv4.PacketConn
net.Interface
address *net.UDPAddr
logger zerolog.Logger
store *store.Store
}
func NewServer(addr, ifname string, store *store.Store) (server *Server, err error) {
server = &Server{
address: &net.UDPAddr{
IP: net.ParseIP(addr),
Port: 67,
Zone: ifname,
},
logger: log.With().Str("service", "dhcpv4").Logger(),
store: store,
}
return server, nil
}
// MaxDatagram is the maximum length of message that can be received.
const MaxDatagram = 1 << 16
func (server *Server) Serve() {
var err error
// binds to specific interface (e.g. eth0) if provided
server.UdpConn, err = server4.NewIPv4UDPConn(server.address.Zone, server.address)
if err != nil {
server.logger.Fatal().
Err(err).
Msgf("Cannot bind to %+v", server.address)
return
}
server.PacketConn = ipv4.NewPacketConn(server.UdpConn)
var ifi *net.Interface
if server.address.Zone != "" {
ifi, err = net.InterfaceByName(server.address.Zone)
if err != nil {
server.logger.Fatal().
Err(err).
Msg("could not find interface: " + server.address.Zone)
return
}
server.Interface = *ifi
} else {
// When not bound to an interface, we need the information in each
// packet to know which interface it came on
err = server.SetControlMessage(ipv4.FlagInterface, true)
if err != nil {
server.logger.Fatal().
Err(err).
Msg("Cannot set control message when not specifying interface")
return
}
}
if server.address.IP.IsMulticast() {
err = server.JoinGroup(ifi, server.address)
if err != nil {
server.logger.Fatal().
Err(err).
Msg("Cannot join multicast group")
return
}
}
log.Debug().Msgf("Listen %s", server.LocalAddr())
for {
b := make([]byte, MaxDatagram)
n, oob, peer, err := server.ReadFrom(b)
if err != nil {
server.logger.
Error().
Err(err).
Msg("error reading from connection")
}
go server.HandleMsg4(b[:n], oob, peer.(*net.UDPAddr))
}
}