From 9c999f98fb9bb2294e8031d75f0396277dfe465b Mon Sep 17 00:00:00 2001
From: Simon Zolin <s.zolin@adguard.com>
Date: Tue, 25 Aug 2020 14:07:11 +0300
Subject: [PATCH] + dhcp custom options
Squashed commit of the following:
commit 140ac16568383cab2270e5d5ba895959902dd943
Merge: d5ed73b5 cb6ca3b0
Author: Simon Zolin <s.zolin@adguard.com>
Date: Tue Aug 25 13:46:34 2020 +0300
Merge remote-tracking branch 'origin/master' into 1585-dhcp-options
commit d5ed73b5e4f068b823fe97ab1161753670d10387
Author: Simon Zolin <s.zolin@adguard.com>
Date: Fri Aug 21 18:16:41 2020 +0300
minor
commit f5208a0b050c2dd462b32edee0379758cc6e5003
Author: Simon Zolin <s.zolin@adguard.com>
Date: Mon Jun 1 14:09:39 2020 +0300
+ dhcpv4 custom options
---
AGHTechDoc.md | 34 ++++++++++++++++++++++++----------
dhcpd/dhcpd.go | 44 ++++++++++++++++++++++++++++++++++++++++++++
dhcpd/dhcpd_test.go | 22 ++++++++++++++++++++++
dhcpd/server.go | 16 ++++++++++++++++
dhcpd/v4.go | 18 ++++++++++++++++++
dhcpd/v4_test.go | 6 ++++++
6 files changed, 130 insertions(+), 10 deletions(-)
diff --git a/AGHTechDoc.md b/AGHTechDoc.md
index 99bc6a8c..b0b6ca80 100644
--- a/AGHTechDoc.md
+++ b/AGHTechDoc.md
@@ -25,12 +25,13 @@ Contents:
* API: Find clients by IP
* DHCP server
* DHCP server in DNS
- * "Show DHCP interfaces" command
- * "Show DHCP status" command
- * "Check DHCP" command
- * "Enable DHCP" command
+ * DHCP Custom Options
+ * API: Show DHCP interfaces
+ * API: Show DHCP status
+ * API: Check DHCP
+ * API: Enable DHCP
* Static IP check/set
- * Add a static lease
+ * API: Add a static lease
* API: Reset DHCP configuration
* DNS general settings
* API: Get DNS general settings
@@ -429,7 +430,20 @@ DHCP leases are used in several ways by DNS module.
> PTR 100.1.168.192.in-addr.arpa. = bills-notebook.
-### "Show DHCP interfaces" command
+### DHCP Custom Options
+
+Option with arbitrary hexadecimal data:
+
+ DEC_CODE hex HEX_DATA
+
+where DEC_CODE is a decimal DHCPv4 option code in range [1..255]
+
+Option with IP data (only 1 IP is supported):
+
+ DEC_CODE ip IP_ADDR
+
+
+### API: Show DHCP interfaces
Request:
@@ -452,7 +466,7 @@ Response:
}
-### "Show DHCP status" command
+### API: Show DHCP status
Request:
@@ -487,7 +501,7 @@ Response:
}
-### "Check DHCP" command
+### API: Check DHCP
Request:
@@ -535,7 +549,7 @@ If `static_ip.static` is:
In order to use DHCP server a static IP address must be set. We failed to determine if this network interface is configured using static IP address. Please set a static IP address manually.
-### "Enable DHCP" command
+### API: Enable DHCP
Request:
@@ -662,7 +676,7 @@ or:
systemctl restart system-networkd
-### Add a static lease
+### API: Add a static lease
Request:
diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go
index f6e19d5a..46beebca 100644
--- a/dhcpd/dhcpd.go
+++ b/dhcpd/dhcpd.go
@@ -1,11 +1,15 @@
package dhcpd
import (
+ "encoding/hex"
"net"
"net/http"
"path/filepath"
+ "strconv"
+ "strings"
"time"
+ "github.com/AdguardTeam/AdGuardHome/util"
"github.com/AdguardTeam/golibs/log"
)
@@ -214,3 +218,43 @@ func (s *Server) FindMACbyIP(ip net.IP) net.HardwareAddr {
func (s *Server) AddStaticLease(lease Lease) error {
return s.srv4.AddStaticLease(lease)
}
+
+// Parse option string
+// Format:
+// CODE TYPE VALUE
+func parseOptionString(s string) (uint8, []byte) {
+ s = strings.TrimSpace(s)
+ scode := util.SplitNext(&s, ' ')
+ t := util.SplitNext(&s, ' ')
+ sval := util.SplitNext(&s, ' ')
+
+ code, err := strconv.Atoi(scode)
+ if err != nil || code <= 0 || code > 255 {
+ return 0, nil
+ }
+
+ var val []byte
+
+ switch t {
+ case "hex":
+ val, err = hex.DecodeString(sval)
+ if err != nil {
+ return 0, nil
+ }
+
+ case "ip":
+ ip := net.ParseIP(sval)
+ if ip == nil {
+ return 0, nil
+ }
+ val = ip
+ if ip.To4() != nil {
+ val = ip.To4()
+ }
+
+ default:
+ return 0, nil
+ }
+
+ return uint8(code), val
+}
diff --git a/dhcpd/dhcpd_test.go b/dhcpd/dhcpd_test.go
index ab31c900..9e4222cf 100644
--- a/dhcpd/dhcpd_test.go
+++ b/dhcpd/dhcpd_test.go
@@ -108,3 +108,25 @@ func TestNormalizeLeases(t *testing.T) {
assert.True(t, bytes.Equal(leases[1].HWAddr, []byte{2, 2, 3, 4}))
assert.True(t, bytes.Equal(leases[2].HWAddr, []byte{1, 2, 3, 5}))
}
+
+func TestOptions(t *testing.T) {
+ code, val := parseOptionString(" 12 hex abcdef ")
+ assert.Equal(t, uint8(12), code)
+ assert.True(t, bytes.Equal([]byte{0xab, 0xcd, 0xef}, val))
+
+ code, _ = parseOptionString(" 12 hex abcdef1 ")
+ assert.Equal(t, uint8(0), code)
+
+ code, val = parseOptionString("123 ip 1.2.3.4")
+ assert.Equal(t, uint8(123), code)
+ assert.Equal(t, "1.2.3.4", net.IP(string(val)).String())
+
+ code, _ = parseOptionString("256 ip 1.1.1.1")
+ assert.Equal(t, uint8(0), code)
+ code, _ = parseOptionString("-1 ip 1.1.1.1")
+ assert.Equal(t, uint8(0), code)
+ code, _ = parseOptionString("12 ip 1.1.1.1x")
+ assert.Equal(t, uint8(0), code)
+ code, _ = parseOptionString("12 x 1.1.1.1")
+ assert.Equal(t, uint8(0), code)
+}
diff --git a/dhcpd/server.go b/dhcpd/server.go
index 5aea9497..1701c780 100644
--- a/dhcpd/server.go
+++ b/dhcpd/server.go
@@ -50,12 +50,23 @@ type V4ServerConf struct {
// 0: disable
ICMPTimeout uint32 `yaml:"icmp_timeout_msec"`
+ // Custom Options.
+ //
+ // Option with arbitrary hexadecimal data:
+ // DEC_CODE hex HEX_DATA
+ // where DEC_CODE is a decimal DHCPv4 option code in range [1..255]
+ //
+ // Option with IP data (only 1 IP is supported):
+ // DEC_CODE ip IP_ADDR
+ Options []string `yaml:"options"`
+
ipStart net.IP // starting IP address for dynamic leases
ipEnd net.IP // ending IP address for dynamic leases
leaseTime time.Duration // the time during which a dynamic lease is considered valid
dnsIPAddrs []net.IP // IPv4 addresses to return to DHCP clients as DNS server addresses
routerIP net.IP // value for Option Router
subnetMask net.IPMask // value for Option SubnetMask
+ options []dhcpOption
// Server calls this function when leases data changes
notify func(uint32)
@@ -79,3 +90,8 @@ type V6ServerConf struct {
// Server calls this function when leases data changes
notify func(uint32)
}
+
+type dhcpOption struct {
+ code uint8
+ val []byte
+}
diff --git a/dhcpd/v4.go b/dhcpd/v4.go
index ac0f9808..fdc63cd4 100644
--- a/dhcpd/v4.go
+++ b/dhcpd/v4.go
@@ -475,6 +475,10 @@ func (s *v4Server) process(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) int {
resp.UpdateOption(dhcpv4.OptRouter(s.conf.routerIP))
resp.UpdateOption(dhcpv4.OptSubnetMask(s.conf.subnetMask))
resp.UpdateOption(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
+
+ for _, opt := range s.conf.options {
+ resp.Options[opt.code] = opt.val
+ }
return 1
}
@@ -619,5 +623,19 @@ func v4Create(conf V4ServerConf) (DHCPServer, error) {
s.conf.leaseTime = time.Second * time.Duration(conf.LeaseDuration)
}
+ for _, o := range conf.Options {
+ code, val := parseOptionString(o)
+ if code == 0 {
+ log.Debug("DHCPv4: bad option string: %s", o)
+ continue
+ }
+
+ opt := dhcpOption{
+ code: code,
+ val: val,
+ }
+ s.conf.options = append(s.conf.options, opt)
+ }
+
return s, nil
}
diff --git a/dhcpd/v4_test.go b/dhcpd/v4_test.go
index 208dd8fb..fe3ac2dd 100644
--- a/dhcpd/v4_test.go
+++ b/dhcpd/v4_test.go
@@ -178,6 +178,10 @@ func TestV4DynamicLeaseGet(t *testing.T) {
GatewayIP: "192.168.10.1",
SubnetMask: "255.255.255.0",
notify: notify4,
+ Options: []string{
+ "81 hex 303132",
+ "82 ip 1.2.3.4",
+ },
}
sIface, err := v4Create(conf)
s := sIface.(*v4Server)
@@ -198,6 +202,8 @@ func TestV4DynamicLeaseGet(t *testing.T) {
assert.Equal(t, "192.168.10.1", resp.ServerIdentifier().String())
assert.Equal(t, "255.255.255.0", net.IP(resp.SubnetMask()).String())
assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds())
+ assert.Equal(t, []byte("012"), resp.Options[uint8(dhcpv4.OptionFQDN)])
+ assert.Equal(t, "1.2.3.4", net.IP(resp.Options[uint8(dhcpv4.OptionRelayAgentInformation)]).String())
// "Request"
req, _ = dhcpv4.NewRequestFromOffer(resp)