kvm/pkg/nmlite/jetdhcpc/dhcp4.go

86 lines
2.2 KiB
Go

package jetdhcpc
import (
"fmt"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/insomniacslk/dhcp/dhcpv4/nclient4"
"github.com/vishvananda/netlink"
)
func (c *Client) requestLease4(ifname string) (*Lease, error) {
iface, err := netlink.LinkByName(ifname)
if err != nil {
return nil, err
}
l := c.l.With().Str("interface", ifname).Logger()
mods := []nclient4.ClientOpt{
nclient4.WithTimeout(c.cfg.Timeout),
nclient4.WithRetry(c.cfg.Retries),
}
mods = append(mods, c.getDHCP4Logger(ifname))
if c.cfg.V4ServerAddr != nil {
mods = append(mods, nclient4.WithServerAddr(c.cfg.V4ServerAddr))
}
client, err := nclient4.New(ifname, mods...)
if err != nil {
return nil, err
}
defer client.Close()
// Prepend modifiers with default options, so they can be overridden.
reqmods := append(
[]dhcpv4.Modifier{
dhcpv4.WithOption(dhcpv4.OptClassIdentifier(VendorIdentifier)),
dhcpv4.WithRequestedOptions(
dhcpv4.OptionSubnetMask,
dhcpv4.OptionInterfaceMTU,
dhcpv4.OptionNTPServers,
dhcpv4.OptionDomainName,
dhcpv4.OptionDomainNameServer,
dhcpv4.OptionDNSDomainSearchList,
),
},
c.cfg.Modifiers4...)
if c.cfg.V4ClientIdentifier {
// Client Id is hardware type + mac per RFC 2132 9.14.
ident := []byte{0x01} // Type ethernet
ident = append(ident, iface.Attrs().HardwareAddr...)
reqmods = append(reqmods, dhcpv4.WithOption(dhcpv4.OptClientIdentifier(ident)))
}
if c.cfg.Hostname != "" {
reqmods = append(reqmods, dhcpv4.WithOption(dhcpv4.OptHostName(c.cfg.Hostname)))
}
l.Info().Msg("attempting to get DHCPv4 lease")
var (
lease *nclient4.Lease
reqErr error
)
if c.currentLease4 != nil {
l.Info().Msg("current lease is not nil, renewing")
lease, reqErr = client.Renew(c.ctx, c.currentLease4.p4, reqmods...)
} else {
l.Info().Msg("current lease is nil, requesting new lease")
lease, reqErr = client.Request(c.ctx, reqmods...)
}
if reqErr != nil {
return nil, reqErr
}
if lease == nil || lease.ACK == nil {
return nil, fmt.Errorf("failed to acquire DHCPv4 lease")
}
summaryStructured(lease.ACK, &l).Info().Msgf("DHCPv4 lease acquired: %s", lease.ACK.String())
l.Trace().Interface("options", lease.ACK.Options.String()).Msg("DHCPv4 lease options")
return fromNclient4Lease(lease, ifname), nil
}