ITQC/containernetworking-plugins
24
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 34 Wiki Activity

fix(dhcp): can not renew an ip address

Browse Source 
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>
This commit is contained in:
Songmin Li
2024-09-14 22:00:20 +08:00
committed by Casey Callendrello
parent e4950728ce
commit d61e7e5e1f
310 changed files with 12785 additions and 11182 deletions
Download Patch File Download Diff File Expand all files Collapse all files

117
plugins/ipam/dhcp/options.go
View File

@ -15,13 +15,11 @@
package main
import (
"encoding/binary"
"fmt"
"net"
"strconv"
"time"
"github.com/d2g/dhcp4"
dhcp4 "github.com/insomniacslk/dhcp/dhcpv4"
"github.com/containernetworking/cni/pkg/types"
)
@ -31,8 +29,8 @@ var optionNameToID = map[string]dhcp4.OptionCode{
"subnet-mask": dhcp4.OptionSubnetMask,
"routers": dhcp4.OptionRouter,
"host-name": dhcp4.OptionHostName,
"user-class": dhcp4.OptionUserClass,
"vendor-class-identifier": dhcp4.OptionVendorClassIdentifier,
"user-class": dhcp4.OptionUserClassInformation,
"vendor-class-identifier": dhcp4.OptionClassIdentifier,
}
func parseOptionName(option string) (dhcp4.OptionCode, error) {
@ -41,18 +39,9 @@ func parseOptionName(option string) (dhcp4.OptionCode, error) {
}
i, err := strconv.ParseUint(option, 10, 8)
if err != nil {
return 0, fmt.Errorf("Can not parse option: %w", err)
return dhcp4.OptionPad, fmt.Errorf("Can not parse option: %w", err)
}
return dhcp4.OptionCode(i), nil
}
func parseRouter(opts dhcp4.Options) net.IP {
if opts, ok := opts[dhcp4.OptionRouter]; ok {
if len(opts) == 4 {
return net.IP(opts)
}
}
return nil
return dhcp4.GenericOptionCode(i), nil
}
func classfulSubnet(sn net.IP) net.IPNet {
@ -62,100 +51,22 @@ func classfulSubnet(sn net.IP) net.IPNet {
}
}
func parseRoutes(opts dhcp4.Options) []*types.Route {
func parseRoutes(opt []byte) []*types.Route {
// StaticRoutes format: pairs of:
// Dest = 4 bytes; Classful IP subnet
// Router = 4 bytes; IP address of router
routes := []*types.Route{}
if opt, ok := opts[dhcp4.OptionStaticRoute]; ok {
for len(opt) >= 8 {
sn := opt[0:4]
r := opt[4:8]
rt := &types.Route{
Dst: classfulSubnet(sn),
GW: r,
}
routes = append(routes, rt)
opt = opt[8:]
for len(opt) >= 8 {
sn := opt[0:4]
r := opt[4:8]
rt := &types.Route{
Dst: classfulSubnet(sn),
GW: r,
}
routes = append(routes, rt)
opt = opt[8:]
}
return routes
}
func parseCIDRRoutes(opts dhcp4.Options) []*types.Route {
// See RFC4332 for format (http://tools.ietf.org/html/rfc3442)
routes := []*types.Route{}
if opt, ok := opts[dhcp4.OptionClasslessRouteFormat]; ok {
for len(opt) >= 5 {
width := int(opt[0])
if width > 32 {
// error: can't have more than /32
return nil
}
// network bits are compacted to avoid zeros
octets := 0
if width > 0 {
octets = (width-1)/8 + 1
}
if len(opt) < 1+octets+4 {
// error: too short
return nil
}
sn := make([]byte, 4)
copy(sn, opt[1:octets+1])
gw := net.IP(opt[octets+1 : octets+5])
rt := &types.Route{
Dst: net.IPNet{
IP: net.IP(sn),
Mask: net.CIDRMask(width, 32),
},
GW: gw,
}
routes = append(routes, rt)
opt = opt[octets+5:]
}
}
return routes
}
func parseSubnetMask(opts dhcp4.Options) net.IPMask {
mask, ok := opts[dhcp4.OptionSubnetMask]
if !ok {
return nil
}
return net.IPMask(mask)
}
func parseDuration(opts dhcp4.Options, code dhcp4.OptionCode, optName string) (time.Duration, error) {
val, ok := opts[code]
if !ok {
return 0, fmt.Errorf("option %v not found", optName)
}
if len(val) != 4 {
return 0, fmt.Errorf("option %v is not 4 bytes", optName)
}
secs := binary.BigEndian.Uint32(val)
return time.Duration(secs) * time.Second, nil
}
func parseLeaseTime(opts dhcp4.Options) (time.Duration, error) {
return parseDuration(opts, dhcp4.OptionIPAddressLeaseTime, "LeaseTime")
}
func parseRenewalTime(opts dhcp4.Options) (time.Duration, error) {
return parseDuration(opts, dhcp4.OptionRenewalTimeValue, "RenewalTime")
}
func parseRebindingTime(opts dhcp4.Options) (time.Duration, error) {
return parseDuration(opts, dhcp4.OptionRebindingTimeValue, "RebindingTime")
}