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

62 lines
1.5 KiB
Go

package dhcpv4
import (
"fmt"
)
// AutoConfiguration implements encoding and decoding functions for a
// byte enumeration as used in RFC 2563, Section 2.
type AutoConfiguration byte
const (
DoNotAutoConfigure AutoConfiguration = 0
AutoConfigure AutoConfiguration = 1
)
var autoConfigureToString = map[AutoConfiguration]string{
DoNotAutoConfigure: "DoNotAutoConfigure",
AutoConfigure: "AutoConfigure",
}
// ToBytes returns a serialized stream of bytes for this option.
func (o AutoConfiguration) ToBytes() []byte {
return []byte{byte(o)}
}
// String returns a human-readable string for this option.
func (o AutoConfiguration) String() string {
s := autoConfigureToString[o]
if s != "" {
return s
}
return fmt.Sprintf("UNKNOWN (%d)", byte(o))
}
// FromBytes parses a a single byte into AutoConfiguration
func (o *AutoConfiguration) FromBytes(data []byte) error {
if len(data) == 1 {
*o = AutoConfiguration(data[0])
return nil
}
return fmt.Errorf("Invalid buffer length (%d)", len(data))
}
// GetByte parses any single-byte option
func GetByte(code OptionCode, o Options) (byte, error) {
data := o.Get(code)
if data == nil {
return 0, fmt.Errorf("option not present")
}
if len(data) != 1 {
return 0, fmt.Errorf("Invalid buffer length (%d)", len(data))
}
return data[0], nil
}
// OptAutoConfigure returns a new AutoConfigure option.
//
// The AutoConfigure option is described by RFC 2563, Section 2.
func OptAutoConfigure(autoconf AutoConfiguration) Option {
return Option{Code: OptionAutoConfigure, Value: autoconf}
}