d61e7e5e1f
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>
104 lines
2.5 KiB
Go
104 lines
2.5 KiB
Go
package dhcpv4
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import (
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"fmt"
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"net"
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"strings"
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"github.com/u-root/uio/uio"
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)
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// IPs are IPv4 addresses from a DHCP packet as used and specified by options
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// in RFC 2132, Sections 3.5 through 3.13, 8.2, 8.3, 8.5, 8.6, 8.9, and 8.10.
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//
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// IPs implements the OptionValue type.
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type IPs []net.IP
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// FromBytes parses an IPv4 address from a DHCP packet as used and specified by
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// options in RFC 2132, Sections 3.5 through 3.13, 8.2, 8.3, 8.5, 8.6, 8.9, and
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// 8.10.
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func (i *IPs) FromBytes(data []byte) error {
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buf := uio.NewBigEndianBuffer(data)
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if buf.Len() == 0 {
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return fmt.Errorf("IP DHCP options must always list at least one IP")
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}
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*i = make(IPs, 0, buf.Len()/net.IPv4len)
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for buf.Has(net.IPv4len) {
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*i = append(*i, net.IP(buf.CopyN(net.IPv4len)))
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}
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return buf.FinError()
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}
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// ToBytes marshals IPv4 addresses to a DHCP packet as specified by RFC 2132,
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// Section 3.5 et al.
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func (i IPs) ToBytes() []byte {
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buf := uio.NewBigEndianBuffer(nil)
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for _, ip := range i {
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buf.WriteBytes(ip.To4())
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}
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return buf.Data()
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}
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// String returns a human-readable representation of a list of IPs.
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func (i IPs) String() string {
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s := make([]string, 0, len(i))
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for _, ip := range i {
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s = append(s, ip.String())
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}
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return strings.Join(s, ", ")
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}
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// GetIPs parses a list of IPs from code in o.
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func GetIPs(code OptionCode, o Options) []net.IP {
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v := o.Get(code)
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if v == nil {
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return nil
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}
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var ips IPs
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if err := ips.FromBytes(v); err != nil {
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return nil
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}
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return []net.IP(ips)
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}
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// OptRouter returns a new DHCPv4 Router option.
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//
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// The Router option is described by RFC 2132, Section 3.5.
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func OptRouter(routers ...net.IP) Option {
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return Option{
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Code: OptionRouter,
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Value: IPs(routers),
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}
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}
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// WithRouter updates a packet with the DHCPv4 Router option.
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func WithRouter(routers ...net.IP) Modifier {
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return WithOption(OptRouter(routers...))
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}
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// OptNTPServers returns a new DHCPv4 NTP Server option.
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//
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// The NTP servers option is described by RFC 2132, Section 8.3.
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func OptNTPServers(ntpServers ...net.IP) Option {
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return Option{
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Code: OptionNTPServers,
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Value: IPs(ntpServers),
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}
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}
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// OptDNS returns a new DHCPv4 Domain Name Server option.
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//
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// The DNS server option is described by RFC 2132, Section 3.8.
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func OptDNS(servers ...net.IP) Option {
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return Option{
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Code: OptionDomainNameServer,
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Value: IPs(servers),
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}
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}
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// WithDNS modifies a packet with the DHCPv4 Domain Name Server option.
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func WithDNS(servers ...net.IP) Modifier {
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return WithOption(OptDNS(servers...))
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}
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