func getDynamicIP(t Netlink, link netlink.Link, dc client.Client) (*dhcp.Packet, error) {
var ack *dhcp.Packet
var err error
// use dhcp to acquire address
id, err := client.NewID(link.Attrs().Index, link.Attrs().HardwareAddr)
if err != nil {
return nil, err
}
ack, err = dc.Request(id)
if err != nil {
log.Errorf("error sending dhcp request: %s", err)
return nil, err
}
if ack.YourIP() == nil || ack.SubnetMask() == nil {
err = fmt.Errorf("dhcp assigned nil ip or subnet mask")
log.Error(err)
return nil, err
}
log.Infof("DHCP response: IP=%s, SubnetMask=%s, Gateway=%s, DNS=%s, Lease Time=%s", ack.YourIP(), ack.SubnetMask(), ack.Gateway(), ack.DNS(), ack.LeaseTime())
defer func() {
if err != nil && ack != nil {
dc.Release(ack)
}
}()
return ack, nil
}
func apply(nl Netlink, t *BaseOperations, endpoint *NetworkEndpoint) error {
// Locate interface
slot, err := strconv.Atoi(endpoint.ID)
if err != nil {
detail := fmt.Sprintf("endpoint ID must be a base10 numeric pci slot identifier: %s", err)
return errors.New(detail)
}
link, err := nl.LinkBySlot(int32(slot))
if err != nil {
detail := fmt.Sprintf("unable to acquire reference to link %s: %s", endpoint.ID, err)
return errors.New(detail)
}
// rename the link if needed
link, err = renameLink(nl, link, int32(slot), endpoint)
if err != nil {
detail := fmt.Sprintf("unable to reacquire link %s after rename pass: %s", endpoint.ID, err)
return errors.New(detail)
}
var ack *dhcp.Packet
defer func() {
if err != nil && ack != nil {
t.dhcpClient.Release(ack)
}
}()
var newIP *net.IPNet
if endpoint.IsDynamic() && endpoint.DHCP == nil {
if e, ok := t.dynEndpoints[endpoint.ID]; ok {
// endpoint shares NIC, copy over DHCP
endpoint.DHCP = e[0].DHCP
}
}
log.Debugf("%+v", endpoint)
if endpoint.IsDynamic() {
if endpoint.DHCP == nil {
ack, err = getDynamicIP(nl, link, t.dhcpClient)
if err != nil {
return err
}
endpoint.DHCP = &DHCPInfo{
Assigned: net.IPNet{IP: ack.YourIP(), Mask: ack.SubnetMask()},
Nameservers: ack.DNS(),
Gateway: net.IPNet{IP: ack.Gateway(), Mask: ack.SubnetMask()},
}
}
newIP = &endpoint.DHCP.Assigned
} else {
newIP = endpoint.Static
if newIP.IP.IsUnspecified() {
// managed externally
return nil
}
}
var old *net.IPNet
if !ip.IsUnspecifiedIP(endpoint.Assigned.IP) {
old = &endpoint.Assigned
}
if err = linkAddrUpdate(old, newIP, nl, link); err != nil {
return err
}
updateEndpoint(newIP, endpoint)
if err = updateDefaultRoute(nl, link, endpoint); err != nil {
return err
}
if err = t.updateHosts(endpoint); err != nil {
return err
}
t.resolvConf.RemoveNameservers(endpoint.Network.Nameservers...)
if err = t.updateNameservers(endpoint); err != nil {
return err
}
if endpoint.IsDynamic() {
eps := t.dynEndpoints[endpoint.ID]
found := false
for _, e := range eps {
if e == endpoint {
found = true
break
}
}
if !found {
eps = append(eps, endpoint)
t.dynEndpoints[endpoint.ID] = eps
}
}
// add renew/release loop if necessary
if ack != nil {
if _, ok := t.dhcpLoops[endpoint.ID]; !ok {
stop := make(chan bool)
id, err := client.NewID(link.Attrs().Index, link.Attrs().HardwareAddr)
if err != nil {
log.Errorf("could not make DHCP client id for link %s: %s", link.Attrs().Name, err)
} else {
go t.dhcpLoop(stop, endpoint, ack, id)
t.dhcpLoops[endpoint.ID] = stop
}
}
}
return nil
}