Songmin Li d61e7e5e1f fix(dhcp): can not renew an ip address
The dhcp server is systemd-networkd, and the dhcp
plugin can request an ip but can not renew it.
The systemd-networkd just ignore the renew request.

```
2024/09/14 21:46:00 no DHCP packet received within 10s
2024/09/14 21:46:00 retrying in 31.529038 seconds
2024/09/14 21:46:42 no DHCP packet received within 10s
2024/09/14 21:46:42 retrying in 63.150490 seconds
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: no more tries
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: renewal time expired, rebinding
2024/09/14 21:47:45 Link "eth1" down. Attempting to set up
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: lease rebound, expiration is 2024-09-14 22:47:45.309270751 +0800 CST m=+11730.048516519
```

Follow the https://datatracker.ietf.org/doc/html/rfc2131#section-4.3.6,
following options must not be sent in renew

- Requested IP Address
- Server Identifier

Since the upstream code has been inactive for 6 years,
we should switch to another dhcpv4 library.
The new selected one is https://github.com/insomniacslk/dhcp.

Signed-off-by: Songmin Li <lisongmin@protonmail.com>
2024-10-14 17:42:30 +02:00

57 lines
1.7 KiB
Go

package dhcpv4
import (
"math"
"time"
"github.com/u-root/uio/uio"
)
// MaxLeaseTime is the maximum lease time that can be encoded.
var MaxLeaseTime = math.MaxUint32 * time.Second
// Duration implements the IP address lease time option described by RFC 2132,
// Section 9.2.
type Duration time.Duration
// FromBytes parses a duration from a byte stream according to RFC 2132, Section 9.2.
func (d *Duration) FromBytes(data []byte) error {
buf := uio.NewBigEndianBuffer(data)
*d = Duration(time.Duration(buf.Read32()) * time.Second)
return buf.FinError()
}
// ToBytes returns a serialized stream of bytes for this option.
func (d Duration) ToBytes() []byte {
buf := uio.NewBigEndianBuffer(nil)
buf.Write32(uint32(time.Duration(d) / time.Second))
return buf.Data()
}
// String returns a human-readable string for this option.
func (d Duration) String() string {
return time.Duration(d).String()
}
// OptIPAddressLeaseTime returns a new IP address lease time option.
//
// The IP address lease time option is described by RFC 2132, Section 9.2.
func OptIPAddressLeaseTime(d time.Duration) Option {
return Option{Code: OptionIPAddressLeaseTime, Value: Duration(d)}
}
// The IP address renew time option as described by RFC 2132, Section 9.11.
func OptRenewTimeValue(d time.Duration) Option {
return Option{Code: OptionRenewTimeValue, Value: Duration(d)}
}
// The IP address rebinding time option as described by RFC 2132, Section 9.12.
func OptRebindingTimeValue(d time.Duration) Option {
return Option{Code: OptionRebindingTimeValue, Value: Duration(d)}
}
// The IPv6-Only Preferred option is described by RFC 8925, Section 3.1
func OptIPv6OnlyPreferred(d time.Duration) Option {
return Option{Code: OptionIPv6OnlyPreferred, Value: Duration(d)}
}