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Pull request: 3538 dhcp options

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Merge in DNS/adguard-home from 3538-dhcp-options to master

Closes #3538.
Updates #3366.

Squashed commit of the following:

commit 8b8cd118834aaf393fd13daf2afc9867794ee102
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 13 19:57:09 2021 +0300

    dhcpd: imp tests

commit 1789171283280b6934eed87137a693cd310a9c0a
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 13 19:04:12 2021 +0300

    dhcpd: fix ip version

commit 07108a95a2026592e72cabecbf6275b6dd50c18a
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 13 18:56:21 2021 +0300

    all: imp log of changes

commit 461441b3709bf1383abebffa4067ea89f4763d79
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 13 18:48:55 2021 +0300

    dhcpd: imp code & docs, log changes

commit 723f818baeadb9f0805cad96351a3b117155a103
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 13 17:27:30 2021 +0300

    dhcpd: add default options

commit 575e9d01cf95a564aed31d26a6cc9376850d321a
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Sep 8 13:05:01 2021 +0300

    dhcpd: imp options logic
This commit is contained in:
Eugene Burkov 2021-09-13 20:05:41 +03:00
parent 53f7c0b2df
commit fac574d324
8 changed files with 415 additions and 286 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
CHANGELOG.md
View file

@ -117,7 +117,8 @@ In this release, the schema version has changed from 10 to 12.
- Panic when upstream server responds with empty question section ([#3551]).
- 9GAG blocking ([#3564]).
- DHCP now follows RFCs more closely ([#3443]).
- DHCP now follows RFCs more closely when it comes to response sending and
option selection ([#3443], [#3538]).
- Occasional panics when reading old statistics databases ([#3506]).
- `reload` service action on macOS and FreeBSD ([#3457]).
- Inaccurate using of service actions in the installation script ([#3450]).
@ -190,6 +191,7 @@ In this release, the schema version has changed from 10 to 12.
[#3450]: https://github.com/AdguardTeam/AdGuardHome/issues/3450
[#3457]: https://github.com/AdguardTeam/AdGuardHome/issues/3457
[#3506]: https://github.com/AdguardTeam/AdGuardHome/issues/3506
[#3538]: https://github.com/AdguardTeam/AdGuardHome/issues/3538
[#3551]: https://github.com/AdguardTeam/AdGuardHome/issues/3551
[#3564]: https://github.com/AdguardTeam/AdGuardHome/issues/3564
[#3568]: https://github.com/AdguardTeam/AdGuardHome/issues/3568

134
internal/dhcpd/options.go
View file

@ -1,134 +0,0 @@
package dhcpd
import (
"encoding/hex"
"fmt"
"net"
"strconv"
"strings"
"github.com/AdguardTeam/golibs/errors"
)
// hexDHCPOptionParserHandler parses a DHCP option as a hex-encoded string.
// For example:
//
// 252 hex 736f636b733a2f2f70726f78792e6578616d706c652e6f7267
//
func hexDHCPOptionParserHandler(s string) (data []byte, err error) {
data, err = hex.DecodeString(s)
if err != nil {
return nil, fmt.Errorf("decoding hex: %w", err)
}
return data, nil
}
// ipDHCPOptionParserHandler parses a DHCP option as a single IP address.
// For example:
//
// 6 ip 192.168.1.1
//
func ipDHCPOptionParserHandler(s string) (data []byte, err error) {
ip := net.ParseIP(s)
if ip == nil {
return nil, errors.Error("invalid ip")
}
// Most DHCP options require IPv4, so do not put the 16-byte
// version if we can. Otherwise, the clients will receive weird
// data that looks like four IPv4 addresses.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/2688.
if ip4 := ip.To4(); ip4 != nil {
data = ip4
} else {
data = ip
}
return data, nil
}
// textDHCPOptionParserHandler parses a DHCP option as a simple UTF-8 encoded
// text. For example:
//
// 252 text http://192.168.1.1/wpad.dat
//
func ipsDHCPOptionParserHandler(s string) (data []byte, err error) {
ipStrs := strings.Split(s, ",")
for i, ipStr := range ipStrs {
var ipData []byte
ipData, err = ipDHCPOptionParserHandler(ipStr)
if err != nil {
return nil, fmt.Errorf("parsing ip at index %d: %w", i, err)
}
data = append(data, ipData...)
}
return data, nil
}
// ipsDHCPOptionParserHandler parses a DHCP option as a comma-separates list of
// IP addresses. For example:
//
// 6 ips 192.168.1.1,192.168.1.2
//
func textDHCPOptionParserHandler(s string) (data []byte, err error) {
return []byte(s), nil
}
// dhcpOptionParserHandler is a parser for a single dhcp option type.
type dhcpOptionParserHandler func(s string) (data []byte, err error)
// dhcpOptionParser parses DHCP options.
type dhcpOptionParser struct {
handlers map[string]dhcpOptionParserHandler
}
// newDHCPOptionParser returns a new dhcpOptionParser.
func newDHCPOptionParser() (p *dhcpOptionParser) {
return &dhcpOptionParser{
handlers: map[string]dhcpOptionParserHandler{
"hex": hexDHCPOptionParserHandler,
"ip": ipDHCPOptionParserHandler,
"ips": ipsDHCPOptionParserHandler,
"text": textDHCPOptionParserHandler,
},
}
}
// parse parses an option. See the handlers' documentation for more info.
func (p *dhcpOptionParser) parse(s string) (code uint8, data []byte, err error) {
defer func() { err = errors.Annotate(err, "invalid option string %q: %w", s) }()
s = strings.TrimSpace(s)
parts := strings.SplitN(s, " ", 3)
if len(parts) < 3 {
return 0, nil, errors.Error("need at least three fields")
}
codeStr := parts[0]
typ := parts[1]
val := parts[2]
var code64 uint64
code64, err = strconv.ParseUint(codeStr, 10, 8)
if err != nil {
return 0, nil, fmt.Errorf("parsing option code: %w", err)
}
code = uint8(code64)
h, ok := p.handlers[typ]
if !ok {
return 0, nil, fmt.Errorf("unknown option type %q", typ)
}
data, err = h(val)
if err != nil {
return 0, nil, err
}
return code, data, nil
}

109
internal/dhcpd/options_test.go
View file

@ -1,109 +0,0 @@
package dhcpd
import (
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestDHCPOptionParser(t *testing.T) {
testCases := []struct {
name string
in string
wantErrMsg string
wantData []byte
wantCode uint8
}{{
name: "hex_success",
in: "6 hex c0a80101c0a80102",
wantErrMsg: "",
wantData: []byte{0xC0, 0xA8, 0x01, 0x01, 0xC0, 0xA8, 0x01, 0x02},
wantCode: 6,
}, {
name: "ip_success",
in: "6 ip 1.2.3.4",
wantErrMsg: "",
wantData: []byte{0x01, 0x02, 0x03, 0x04},
wantCode: 6,
}, {
name: "ip_success_v6",
in: "6 ip ::1234",
wantErrMsg: "",
wantData: []byte{
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x12, 0x34,
},
wantCode: 6,
}, {
name: "ips_success",
in: "6 ips 192.168.1.1,192.168.1.2",
wantErrMsg: "",
wantData: []byte{0xC0, 0xA8, 0x01, 0x01, 0xC0, 0xA8, 0x01, 0x02},
wantCode: 6,
}, {
name: "text_success",
in: "252 text http://192.168.1.1/",
wantErrMsg: "",
wantData: []byte("http://192.168.1.1/"),
wantCode: 252,
}, {
name: "bad_parts",
in: "6 ip",
wantErrMsg: `invalid option string "6 ip": need at least three fields`,
wantCode: 0,
wantData: nil,
}, {
name: "bad_code",
in: "256 ip 1.1.1.1",
wantErrMsg: `invalid option string "256 ip 1.1.1.1": parsing option code: ` +
`strconv.ParseUint: parsing "256": value out of range`,
wantCode: 0,
wantData: nil,
}, {
name: "bad_type",
in: "6 bad 1.1.1.1",
wantErrMsg: `invalid option string "6 bad 1.1.1.1": unknown option type "bad"`,
wantCode: 0,
wantData: nil,
}, {
name: "hex_error",
in: "6 hex ZZZ",
wantErrMsg: `invalid option string "6 hex ZZZ": decoding hex: ` +
`encoding/hex: invalid byte: U+005A 'Z'`,
wantData: nil,
wantCode: 0,
}, {
name: "ip_error",
in: "6 ip 1.2.3.x",
wantErrMsg: `invalid option string "6 ip 1.2.3.x": invalid ip`,
wantData: nil,
wantCode: 0,
}, {
name: "ips_error",
in: "6 ips 192.168.1.1,192.168.1.x",
wantErrMsg: `invalid option string "6 ips 192.168.1.1,192.168.1.x": ` +
`parsing ip at index 1: invalid ip`,
wantData: nil,
wantCode: 0,
}}
p := newDHCPOptionParser()
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
code, data, err := p.parse(tc.in)
if tc.wantErrMsg == "" {
assert.Nil(t, err)
} else {
require.NotNil(t, err)
assert.Equal(t, tc.wantErrMsg, err.Error())
}
assert.Equal(t, tc.wantCode, code)
assert.Equal(t, tc.wantData, data)
})
}
}

192
internal/dhcpd/options_unix.go Normal file
View file

@ -0,0 +1,192 @@
//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
package dhcpd
import (
"encoding/hex"
"fmt"
"net"
"strconv"
"strings"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/log"
"github.com/AdguardTeam/golibs/netutil"
"github.com/insomniacslk/dhcp/dhcpv4"
)
// The aliases for DHCP option types available for explicit declaration.
const (
hexTyp = "hex"
ipTyp = "ip"
ipsTyp = "ips"
textTyp = "text"
)
// parseDHCPOptionHex parses a DHCP option as a hex-encoded string. For
// example:
//
// 252 hex 736f636b733a2f2f70726f78792e6578616d706c652e6f7267
//
func parseDHCPOptionHex(s string) (val dhcpv4.OptionValue, err error) {
var data []byte
data, err = hex.DecodeString(s)
if err != nil {
return nil, fmt.Errorf("decoding hex: %w", err)
}
return dhcpv4.OptionGeneric{Data: data}, nil
}
// parseDHCPOptionIP parses a DHCP option as a single IP address. For example:
//
// 6 ip 192.168.1.1
//
func parseDHCPOptionIP(s string) (val dhcpv4.OptionValue, err error) {
var ip net.IP
// All DHCPv4 options require IPv4, so don't put the 16-byte version.
// Otherwise, the clients will receive weird data that looks like four
// IPv4 addresses.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/2688.
if ip, err = netutil.ParseIPv4(s); err != nil {
return nil, err
}
return dhcpv4.IP(ip), nil
}
// parseDHCPOptionIPs parses a DHCP option as a comma-separates list of IP
// addresses. For example:
//
// 6 ips 192.168.1.1,192.168.1.2
//
func parseDHCPOptionIPs(s string) (val dhcpv4.OptionValue, err error) {
var ips dhcpv4.IPs
var ip net.IP
for i, ipStr := range strings.Split(s, ",") {
// See notes in the ipDHCPOptionParserHandler.
if ip, err = netutil.ParseIPv4(ipStr); err != nil {
return nil, fmt.Errorf("parsing ip at index %d: %w", i, err)
}
ips = append(ips, ip)
}
return ips, nil
}
// parseDHCPOptionText parses a DHCP option as a simple UTF-8 encoded
// text. For example:
//
// 252 text http://192.168.1.1/wpad.dat
//
func parseDHCPOptionText(s string) (val dhcpv4.OptionValue) {
return dhcpv4.OptionGeneric{Data: []byte(s)}
}
// parseDHCPOption parses an option. See the documentation of parseDHCPOption*
// for more info.
func parseDHCPOption(s string) (opt dhcpv4.Option, err error) {
defer func() { err = errors.Annotate(err, "invalid option string %q: %w", s) }()
s = strings.TrimSpace(s)
parts := strings.SplitN(s, " ", 3)
if len(parts) < 3 {
return opt, errors.Error("need at least three fields")
}
var code64 uint64
code64, err = strconv.ParseUint(parts[0], 10, 8)
if err != nil {
return opt, fmt.Errorf("parsing option code: %w", err)
}
var optVal dhcpv4.OptionValue
switch typ, val := parts[1], parts[2]; typ {
case hexTyp:
optVal, err = parseDHCPOptionHex(val)
case ipTyp:
optVal, err = parseDHCPOptionIP(val)
case ipsTyp:
optVal, err = parseDHCPOptionIPs(val)
case textTyp:
optVal = parseDHCPOptionText(val)
default:
return opt, fmt.Errorf("unknown option type %q", typ)
}
if err != nil {
return opt, err
}
return dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(code64),
Value: optVal,
}, nil
}
// prepareOptions builds the set of DHCP options according to host requirements
// document and values from conf.
func prepareOptions(conf V4ServerConf) (opts dhcpv4.Options) {
opts = dhcpv4.Options{
// Set default values for host configuration parameters listed
// in Appendix A of RFC-2131. Those parameters, if requested by
// client, should be returned with values defined by Host
// Requirements Document.
//
// See https://datatracker.ietf.org/doc/html/rfc2131#appendix-A.
//
// See also https://datatracker.ietf.org/doc/html/rfc1122,
// https://datatracker.ietf.org/doc/html/rfc1123, and
// https://datatracker.ietf.org/doc/html/rfc2132.
// IP-Layer Per Host
dhcpv4.OptionNonLocalSourceRouting.Code(): []byte{0},
// Set the current recommended default time to live for the
// Internet Protocol which is 64, see
// https://datatracker.ietf.org/doc/html/rfc1700.
dhcpv4.OptionDefaultIPTTL.Code(): []byte{64},
// IP-Layer Per Interface
dhcpv4.OptionPerformMaskDiscovery.Code(): []byte{0},
dhcpv4.OptionMaskSupplier.Code(): []byte{0},
dhcpv4.OptionPerformRouterDiscovery.Code(): []byte{1},
// The all-routers address is preferred wherever possible, see
// https://datatracker.ietf.org/doc/html/rfc1256#section-5.1.
dhcpv4.OptionRouterSolicitationAddress.Code(): net.IPv4allrouter.To4(),
dhcpv4.OptionBroadcastAddress.Code(): net.IPv4bcast.To4(),
// Link-Layer Per Interface
dhcpv4.OptionTrailerEncapsulation.Code(): []byte{0},
dhcpv4.OptionEthernetEncapsulation.Code(): []byte{0},
// TCP Per Host
dhcpv4.OptionTCPKeepaliveInterval.Code(): dhcpv4.Duration(0).ToBytes(),
dhcpv4.OptionTCPKeepaliveGarbage.Code(): []byte{0},
// Values From Configuration
dhcpv4.OptionRouter.Code(): netutil.CloneIP(conf.subnet.IP),
dhcpv4.OptionSubnetMask.Code(): dhcpv4.IPMask(conf.subnet.Mask).ToBytes(),
}
// Set values for explicitly configured options.
for i, o := range conf.Options {
opt, err := parseDHCPOption(o)
if err != nil {
log.Error("dhcpv4: bad option string at index %d: %s", i, err)
continue
}
opts.Update(opt)
}
return opts
}

177
internal/dhcpd/options_unix_test.go Normal file
View file

@ -0,0 +1,177 @@
//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
package dhcpd
import (
"fmt"
"net"
"testing"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestParseOpt(t *testing.T) {
testCases := []struct {
name string
in string
wantErrMsg string
wantOpt dhcpv4.Option
}{{
name: "hex_success",
in: "6 hex c0a80101c0a80102",
wantErrMsg: "",
wantOpt: dhcpv4.OptDNS(
net.IP{0xC0, 0xA8, 0x01, 0x01},
net.IP{0xC0, 0xA8, 0x01, 0x02},
),
}, {
name: "ip_success",
in: "6 ip 1.2.3.4",
wantErrMsg: "",
wantOpt: dhcpv4.OptDNS(
net.IP{0x01, 0x02, 0x03, 0x04},
),
}, {
name: "ip_fail_v6",
in: "6 ip ::1234",
wantErrMsg: "invalid option string \"6 ip ::1234\": bad ipv4 address \"::1234\"",
wantOpt: dhcpv4.Option{},
}, {
name: "ips_success",
in: "6 ips 192.168.1.1,192.168.1.2",
wantErrMsg: "",
wantOpt: dhcpv4.OptDNS(
net.IP{0xC0, 0xA8, 0x01, 0x01},
net.IP{0xC0, 0xA8, 0x01, 0x02},
),
}, {
name: "text_success",
in: "252 text http://192.168.1.1/",
wantErrMsg: "",
wantOpt: dhcpv4.OptGeneric(
dhcpv4.GenericOptionCode(252),
[]byte("http://192.168.1.1/"),
),
}, {
name: "bad_parts",
in: "6 ip",
wantErrMsg: `invalid option string "6 ip": need at least three fields`,
wantOpt: dhcpv4.Option{},
}, {
name: "bad_code",
in: "256 ip 1.1.1.1",
wantErrMsg: `invalid option string "256 ip 1.1.1.1": parsing option code: ` +
`strconv.ParseUint: parsing "256": value out of range`,
wantOpt: dhcpv4.Option{},
}, {
name: "bad_type",
in: "6 bad 1.1.1.1",
wantErrMsg: `invalid option string "6 bad 1.1.1.1": unknown option type "bad"`,
wantOpt: dhcpv4.Option{},
}, {
name: "hex_error",
in: "6 hex ZZZ",
wantErrMsg: `invalid option string "6 hex ZZZ": decoding hex: ` +
`encoding/hex: invalid byte: U+005A 'Z'`,
wantOpt: dhcpv4.Option{},
}, {
name: "ip_error",
in: "6 ip 1.2.3.x",
wantErrMsg: "invalid option string \"6 ip 1.2.3.x\": bad ipv4 address \"1.2.3.x\"",
wantOpt: dhcpv4.Option{},
}, {
name: "ips_error",
in: "6 ips 192.168.1.1,192.168.1.x",
wantErrMsg: "invalid option string \"6 ips 192.168.1.1,192.168.1.x\": " +
"parsing ip at index 1: bad ipv4 address \"192.168.1.x\"",
wantOpt: dhcpv4.Option{},
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
opt, err := parseDHCPOption(tc.in)
if tc.wantErrMsg != "" {
require.Error(t, err)
assert.Equal(t, tc.wantErrMsg, err.Error())
return
}
require.NoError(t, err)
assert.Equal(t, tc.wantOpt.Code.Code(), opt.Code.Code())
assert.Equal(t, tc.wantOpt.Value.ToBytes(), opt.Value.ToBytes())
})
}
}
func TestPrepareOptions(t *testing.T) {
allDefault := dhcpv4.Options{
dhcpv4.OptionNonLocalSourceRouting.Code(): []byte{0},
dhcpv4.OptionDefaultIPTTL.Code(): []byte{64},
dhcpv4.OptionPerformMaskDiscovery.Code(): []byte{0},
dhcpv4.OptionMaskSupplier.Code(): []byte{0},
dhcpv4.OptionPerformRouterDiscovery.Code(): []byte{1},
dhcpv4.OptionRouterSolicitationAddress.Code(): []byte{224, 0, 0, 2},
dhcpv4.OptionBroadcastAddress.Code(): []byte{255, 255, 255, 255},
dhcpv4.OptionTrailerEncapsulation.Code(): []byte{0},
dhcpv4.OptionEthernetEncapsulation.Code(): []byte{0},
dhcpv4.OptionTCPKeepaliveInterval.Code(): []byte{0, 0, 0, 0},
dhcpv4.OptionTCPKeepaliveGarbage.Code(): []byte{0},
}
oneIP, otherIP := net.IP{1, 2, 3, 4}, net.IP{5, 6, 7, 8}
testCases := []struct {
name string
opts []string
checks dhcpv4.Options
}{{
name: "all_default",
checks: allDefault,
}, {
name: "configured_ip",
opts: []string{
fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, oneIP),
},
checks: dhcpv4.Options{
dhcpv4.OptionBroadcastAddress.Code(): oneIP,
},
}, {
name: "configured_ips",
opts: []string{
fmt.Sprintf("%d ips %s,%s", dhcpv4.OptionDomainNameServer, oneIP, otherIP),
},
checks: dhcpv4.Options{
dhcpv4.OptionDomainNameServer.Code(): append(oneIP, otherIP...),
},
}, {
name: "configured_bad",
opts: []string{
"20 hex",
"23 hex abc",
"32 ips 1,2,3,4",
"28 256.256.256.256",
},
checks: allDefault,
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
opts := prepareOptions(V4ServerConf{
// Just to avoid nil pointer dereference.
subnet: &net.IPNet{},
Options: tc.opts,
})
for c, v := range tc.checks {
optVal := opts.Get(dhcpv4.GenericOptionCode(c))
require.NotNil(t, optVal)
assert.Len(t, optVal, len(v))
assert.Equal(t, v, optVal)
}
})
}
}

7
internal/dhcpd/server.go
View file

@ -72,8 +72,6 @@ type V4ServerConf struct {
// gateway.
subnet *net.IPNet
options []dhcpOption
// notify is a way to signal to other components that leases have
// change. notify must be called outside of locked sections, since the
// clients might want to get the new data.
@ -104,8 +102,3 @@ type V6ServerConf struct {
// Server calls this function when leases data changes
notify func(uint32)
}
type dhcpOption struct {
code uint8
data []byte
}

63
internal/dhcpd/v4.go
View file

@ -40,6 +40,9 @@ type v4Server struct {
// leasesLock protects leases, leaseHosts, and leasedOffsets.
leasesLock sync.Mutex
// options holds predefined DHCP options to return to clients.
options dhcpv4.Options
}
// WriteDiskConfig4 - write configuration
@ -831,6 +834,9 @@ func (s *v4Server) processRelease(req, resp *dhcpv4.DHCPv4) (err error) {
func (s *v4Server) process(req, resp *dhcpv4.DHCPv4) int {
var err error
// Include server's identifier option since any reply should contain it.
//
// See https://datatracker.ietf.org/doc/html/rfc2131#page-29.
resp.UpdateOption(dhcpv4.OptServerIdentifier(s.conf.dnsIPAddrs[0]))
// TODO(a.garipov): Refactor this into handlers.
@ -873,17 +879,29 @@ func (s *v4Server) process(req, resp *dhcpv4.DHCPv4) int {
}
if l != nil {
resp.YourIPAddr = make([]byte, 4)
copy(resp.YourIPAddr, l.IP)
resp.YourIPAddr = netutil.CloneIP(l.IP)
}
// Set IP address lease time for all DHCPOFFER messages and DHCPACK
// messages replied for DHCPREQUEST.
//
// TODO(e.burkov): Inspect why this is always set to configured value.
resp.UpdateOption(dhcpv4.OptIPAddressLeaseTime(s.conf.leaseTime))
resp.UpdateOption(dhcpv4.OptRouter(s.conf.subnet.IP))
resp.UpdateOption(dhcpv4.OptSubnetMask(s.conf.subnet.Mask))
resp.UpdateOption(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
for _, opt := range s.conf.options {
resp.Options[opt.code] = opt.data
// Update values for each explicitly configured parameter requested by
// client.
//
// See https://datatracker.ietf.org/doc/html/rfc2131#section-4.3.1.
requested := req.ParameterRequestList()
for _, code := range requested {
if configured := s.options; configured.Has(code) {
resp.UpdateOption(dhcpv4.OptGeneric(code, configured.Get(code)))
}
}
// Update the value of Domain Name Server option separately from others
// since its value is set after server's creating.
if requested.Has(dhcpv4.OptionDomainNameServer) {
resp.UpdateOption(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
}
return 1
@ -897,7 +915,8 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
log.Debug("dhcpv4: received message: %s", req.Summary())
switch req.MessageType() {
case dhcpv4.MessageTypeDiscover,
case
dhcpv4.MessageTypeDiscover,
dhcpv4.MessageTypeRequest,
dhcpv4.MessageTypeDecline,
dhcpv4.MessageTypeRelease:
@ -931,13 +950,13 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
s.send(peer, conn, req, resp)
}
// send writes resp for peer to conn considering the req's fields and options
// according to RFC-2131.
// send writes resp for peer to conn considering the req's parameters according
// to RFC-2131.
//
// See https://datatracker.ietf.org/doc/html/rfc2131#section-4.1.
func (s *v4Server) send(peer net.Addr, conn net.PacketConn, req, resp *dhcpv4.DHCPv4) {
var unicast bool
if giaddr, unspec := req.GatewayIPAddr, netutil.IPv4Zero(); !giaddr.Equal(unspec) {
if giaddr := req.GatewayIPAddr; giaddr != nil && !giaddr.IsUnspecified() {
// Send any return messages to the server port on the BOOTP
// relay agent whose address appears in giaddr.
peer = &net.UDPAddr{
@ -947,7 +966,7 @@ func (s *v4Server) send(peer net.Addr, conn net.PacketConn, req, resp *dhcpv4.DH
unicast = true
} else if mtype := resp.MessageType(); mtype == dhcpv4.MessageTypeNak {
// Broadcast any DHCPNAK messages to 0xffffffff.
} else if ciaddr := req.ClientIPAddr; !ciaddr.Equal(unspec) {
} else if ciaddr := req.ClientIPAddr; ciaddr != nil && !ciaddr.IsUnspecified() {
// Unicast DHCPOFFER and DHCPACK messages to the address in
// ciaddr.
peer = &net.UDPAddr{
@ -1104,25 +1123,7 @@ func v4Create(conf V4ServerConf) (srv DHCPServer, err error) {
s.conf.leaseTime = time.Second * time.Duration(conf.LeaseDuration)
}
p := newDHCPOptionParser()
for i, o := range conf.Options {
var code uint8
var data []byte
code, data, err = p.parse(o)
if err != nil {
log.Error("dhcpv4: bad option string at index %d: %s", i, err)
continue
}
opt := dhcpOption{
code: code,
data: data,
}
s.conf.options = append(s.conf.options, opt)
}
s.options = prepareOptions(s.conf)
return s, nil
}

15
internal/dhcpd/v4_test.go
View file

@ -148,7 +148,9 @@ func TestV4StaticLease_Get(t *testing.T) {
mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}
t.Run("discover", func(t *testing.T) {
req, err = dhcpv4.NewDiscovery(mac)
req, err = dhcpv4.NewDiscovery(mac, dhcpv4.WithRequestedOptions(
dhcpv4.OptionDomainNameServer,
))
require.NoError(t, err)
resp, err = dhcpv4.NewReplyFromRequest(req)
@ -231,7 +233,10 @@ func TestV4DynamicLease_Get(t *testing.T) {
mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}
t.Run("discover", func(t *testing.T) {
req, err = dhcpv4.NewDiscovery(mac)
req, err = dhcpv4.NewDiscovery(mac, dhcpv4.WithRequestedOptions(
dhcpv4.OptionFQDN,
dhcpv4.OptionRelayAgentInformation,
))
require.NoError(t, err)
resp, err = dhcpv4.NewReplyFromRequest(req)
@ -257,9 +262,11 @@ func TestV4DynamicLease_Get(t *testing.T) {
assert.Equal(t, s.conf.subnet.Mask, resp.SubnetMask())
assert.Equal(t, s.conf.leaseTime.Seconds(), resp.IPAddressLeaseTime(-1).Seconds())
assert.Equal(t, []byte("012"), resp.Options[uint8(dhcpv4.OptionFQDN)])
assert.Equal(t, []byte("012"), resp.Options.Get(dhcpv4.OptionFQDN))
assert.Equal(t, net.IP{1, 2, 3, 4}, net.IP(resp.RelayAgentInfo().ToBytes()))
rai := resp.RelayAgentInfo()
require.NotNil(t, rai)
assert.Equal(t, net.IP{1, 2, 3, 4}, net.IP(rai.ToBytes()))
})
t.Run("request", func(t *testing.T) {