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>

vendor/github.com/u-root/uio/rand/random.go

@@ -0,0 +1,62 @@
+// Copyright 2019 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package rand implements cancelable reads from a cryptographically safe
+// random number source.
+package rand
+
+import (
+	"context"
+)
+
+// Reader is a cryptographically safe random number source.
+var Reader = DefaultReaderWithContext(context.Background())
+
+// Read blockingly reads from a random number source.
+func Read(b []byte) (int, error) {
+	return Reader.Read(b)
+}
+
+// ReadContext is a context-aware reader for random numbers.
+func ReadContext(ctx context.Context, b []byte) (int, error) {
+	return Reader.ReadContext(ctx, b)
+}
+
+// ContextReader is a cancelable io.Reader.
+type ContextReader interface {
+	// Read behaves like a blocking io.Reader.Read.
+	//
+	// Read wraps ReadContext with a background context.
+	Read(b []byte) (n int, err error)
+
+	// ReadContext is an io.Reader that blocks until data is available or
+	// until ctx is done.
+	ReadContext(ctx context.Context, b []byte) (n int, err error)
+}
+
+// contextReader is a cancelable io.Reader.
+type contextReader interface {
+	ReadContext(context.Context, []byte) (int, error)
+}
+
+// ctxReader takes a contextReader and turns it into a ContextReader.
+type ctxReader struct {
+	contextReader
+	ctx context.Context //nolint:containedctx
+}
+
+func (cr ctxReader) Read(b []byte) (int, error) {
+	return cr.contextReader.ReadContext(cr.ctx, b)
+}
+
+// DefaultReaderWithContext returns a context-aware io.Reader.
+//
+// Because this stores the context, only use this in situations where an
+// io.Reader is unavoidable.
+func DefaultReaderWithContext(ctx context.Context) ContextReader {
+	return ctxReader{
+		ctx:           ctx,
+		contextReader: defaultContextReader,
+	}
+}

vendor/github.com/u-root/uio/rand/random_linux.go

@@ -0,0 +1,77 @@
+// Copyright 2019 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rand
+
+import (
+	"context"
+	"log"
+	"os"
+	"sync"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+var defaultContextReader = &getrandomReader{}
+
+var backupReader = &urandomReader{}
+
+type getrandomReader struct {
+	once   sync.Once
+	backup bool
+}
+
+// ReadContext implements a cancelable read from /dev/urandom.
+func (r *getrandomReader) ReadContext(ctx context.Context, b []byte) (int, error) {
+	r.once.Do(func() {
+		if os.Getenv("UROOT_NOHWRNG") != "" {
+			r.backup = true
+			return
+		}
+		if _, err := unix.Getrandom(b, unix.GRND_NONBLOCK); err == syscall.ENOSYS {
+			r.backup = true
+		}
+	})
+	if r.backup {
+		return backupReader.ReadContext(ctx, b)
+	}
+
+	for {
+		// getrandom(2) with GRND_NONBLOCK uses the urandom number
+		// source, but only returns numbers if the crng has been
+		// initialized.
+		//
+		// This is preferrable to /dev/urandom, as /dev/urandom will
+		// make up fake random numbers until the crng has been
+		// initialized.
+		n, err := unix.Getrandom(b, unix.GRND_NONBLOCK)
+		if err == nil {
+			return n, nil
+		}
+		select {
+		case <-ctx.Done():
+			return 0, ctx.Err()
+
+		default:
+			if err != syscall.EAGAIN && err != syscall.EINTR {
+				return n, err
+			}
+		}
+	}
+}
+
+// ReadContextWithSlowLogs logs a helpful message if it takes a significant
+// amount of time (>2s) to produce random data.
+func (r *getrandomReader) ReadContextWithSlowLogs(ctx context.Context, b []byte) (int, error) {
+	d := 2 * time.Second
+	t := time.AfterFunc(d, func() {
+		log.Printf("getrandom is taking a long time (>%v). "+
+			"If running on hardware, consider enabling Linux's CONFIG_RANDOM_TRUST_CPU=y. "+
+			"If running in a VM/emulator, try setting up virtio-rng.", d)
+	})
+	defer t.Stop()
+	return r.ReadContext(ctx, b)
+}

vendor/github.com/u-root/uio/rand/random_std.go

@@ -0,0 +1,32 @@
+// Copyright 2020 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build plan9 || windows
+// +build plan9 windows
+
+package rand
+
+import (
+	"context"
+	"crypto/rand"
+)
+
+var defaultContextReader = &cryptoRandReader{}
+
+type cryptoRandReader struct{}
+
+// ReadContext implements a cancelable read.
+func (r *cryptoRandReader) ReadContext(ctx context.Context, b []byte) (n int, err error) {
+	ch := make(chan struct{})
+	go func() {
+		n, err = rand.Reader.Read(b)
+		close(ch)
+	}()
+	select {
+	case <-ctx.Done():
+		return 0, ctx.Err()
+	case <-ch:
+		return n, err
+	}
+}

vendor/github.com/u-root/uio/rand/random_unix.go

@@ -0,0 +1,10 @@
+// Copyright 2019 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || nacl || netbsd || openbsd || solaris
+// +build aix darwin dragonfly freebsd nacl netbsd openbsd solaris
+
+package rand
+
+var defaultContextReader = &urandomReader{}

vendor/github.com/u-root/uio/rand/random_urandom.go

@@ -0,0 +1,60 @@
+// Copyright 2019 the u-root Authors. All rights reserved
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || nacl || netbsd || openbsd || solaris || linux
+// +build aix darwin dragonfly freebsd nacl netbsd openbsd solaris linux
+
+package rand
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// urandomReader is a contextReader.
+type urandomReader struct {
+	once sync.Once
+
+	// fd is expected to be non-blocking.
+	fd int
+}
+
+func (r *urandomReader) init() error {
+	var realErr error
+	r.once.Do(func() {
+		fd, err := unix.Open("/dev/urandom", unix.O_RDONLY, 0)
+		if err != nil {
+			realErr = fmt.Errorf("open(/dev/urandom): %v", err)
+			return
+		}
+		r.fd = fd
+	})
+	return realErr
+}
+
+// ReadContext implements a cancelable read from /dev/urandom.
+func (r *urandomReader) ReadContext(ctx context.Context, b []byte) (int, error) {
+	if err := r.init(); err != nil {
+		return 0, err
+	}
+	for {
+		n, err := unix.Read(r.fd, b)
+		if err == nil {
+			return n, nil
+		}
+		select {
+		case <-ctx.Done():
+			return 0, ctx.Err()
+
+		default:
+			if err != syscall.EAGAIN && err != syscall.EINTR {
+				return n, err
+			}
+		}
+	}
+}