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Pull request: 4705 fix opts

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Merge in DNS/adguard-home from 4705-fix-opts to master

Updates #4705.

Squashed commit of the following:

commit d3924c443260af3d32d73bd784efff2bf8dd612e
Merge: e46198c6 e545f3bd
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 5 16:57:38 2022 +0300

    Merge branch 'master' into 4705-fix-opts

commit e46198c6d8da4dcadabecfd9c1b33cc472efe612
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Sep 5 16:52:20 2022 +0300

    dhcpd: immp docs

commit 1c1caeaa1b2eb642fa83aa5a88ec041af9963591
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Sat Sep 3 17:31:35 2022 +0300

    dhcpd: fix logic, imp docs

commit bc74e21b9eb79fe22170b0e02cddcbd4bf78d860
Merge: 280ad10f 1fb04376
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Sep 2 18:58:52 2022 +0300

    Merge branch 'master' into 4705-fix-opts

commit 280ad10f63f954f89b42cdf206a8240f8d4de503
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Fri Sep 2 00:53:38 2022 +0300

    dhcpd: imp docs, tests

commit 600fa44f35683ba4b340843be13786e9383ead89
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 1 20:24:52 2022 +0300

    dhcpd: add new opts

commit caf0cc6b370a04e6e002428b49f8d54cba105d5a
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 1 18:13:02 2022 +0300

    dhcpd: log changes

commit 3d2c61d9b8fd19c8d1e4f43ac9aac3cb94cdd4d3
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Sep 1 18:09:34 2022 +0300

    dhcpd: imp opts
This commit is contained in:
Eugene Burkov 2022-09-05 17:01:33 +03:00
parent e545f3bdb7
commit 9c9169ac12
6 changed files with 580 additions and 197 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
CHANGELOG.md
View File

@ -22,8 +22,12 @@ and this project adheres to
### Added
- New `bool`, `dur`, `u8`, and `u16` DHCP options to provide more convenience on
options control by setting values in a human-readable format ([#4705]). See
also a [Wiki page][wiki-dhcp-opts].
- New `del` DHCP option which removes the corresponding option from server's
response ([#4337]).
response ([#4337]). See also a [Wiki page][wiki-dhcp-opts].
**NOTE:** This modifier affects all the parameters in the response and not
only the requested ones.
@ -32,6 +36,7 @@ and this project adheres to
### Changed
- The DHCP options handling is now closer to the [RFC 2131][rfc-2131] ([#4705]).
- When the DHCP server is enabled, queries for domain names under
`dhcp.local_domain_name` not pointing to real DHCP client hostnames are now
processed by filters ([#4865]).
@ -57,12 +62,14 @@ and this project adheres to
[#4337]: https://github.com/AdguardTeam/AdGuardHome/issues/4337
[#4403]: https://github.com/AdguardTeam/AdGuardHome/issues/4403
[#4535]: https://github.com/AdguardTeam/AdGuardHome/issues/4535
[#4705]: https://github.com/AdguardTeam/AdGuardHome/issues/4705
[#4745]: https://github.com/AdguardTeam/AdGuardHome/issues/4745
[#4850]: https://github.com/AdguardTeam/AdGuardHome/issues/4850
[#4863]: https://github.com/AdguardTeam/AdGuardHome/issues/4863
[#4865]: https://github.com/AdguardTeam/AdGuardHome/issues/4865
[rfc-2131]: https://datatracker.ietf.org/doc/html/rfc2131
[rfc-2131]: https://datatracker.ietf.org/doc/html/rfc2131
[wiki-dhcp-opts]: https://github.com/adguardTeam/adGuardHome/wiki/DHCP#config-4

322
internal/dhcpd/options_unix.go
View File

@ -9,20 +9,28 @@ import (
"net"
"strconv"
"strings"
"time"
"github.com/AdguardTeam/golibs/errors"
"github.com/AdguardTeam/golibs/log"
"github.com/AdguardTeam/golibs/netutil"
"github.com/AdguardTeam/golibs/timeutil"
"github.com/insomniacslk/dhcp/dhcpv4"
)
// The aliases for DHCP option types available for explicit declaration.
//
// TODO(e.burkov): Add an option for classless routes.
const (
typDel = "del"
typBool = "bool"
typDur = "dur"
typHex = "hex"
typIP = "ip"
typIPs = "ips"
typText = "text"
typDel = "del"
typU8 = "u8"
typU16 = "u16"
)
// parseDHCPOptionHex parses a DHCP option as a hex-encoded string.
@ -40,8 +48,8 @@ func parseDHCPOptionHex(s string) (val dhcpv4.OptionValue, err error) {
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.
// 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 {
@ -55,35 +63,76 @@ func parseDHCPOptionIP(s string) (val dhcpv4.OptionValue, err error) {
// addresses.
func parseDHCPOptionIPs(s string) (val dhcpv4.OptionValue, err error) {
var ips dhcpv4.IPs
var ip net.IP
var ip dhcpv4.OptionValue
for i, ipStr := range strings.Split(s, ",") {
// See notes in the ipDHCPOptionParserHandler.
if ip, err = netutil.ParseIPv4(ipStr); err != nil {
ip, err = parseDHCPOptionIP(ipStr)
if err != nil {
return nil, fmt.Errorf("parsing ip at index %d: %w", i, err)
}
ips = append(ips, ip)
ips = append(ips, net.IP(ip.(dhcpv4.IP)))
}
return ips, nil
}
// parseDHCPOptionText parses a DHCP option as a simple UTF-8 encoded
// text.
func parseDHCPOptionText(s string) (val dhcpv4.OptionValue) {
return dhcpv4.OptionGeneric{Data: []byte(s)}
// parseDHCPOptionDur parses a DHCP option as a duration in a human-readable
// form.
func parseDHCPOptionDur(s string) (val dhcpv4.OptionValue, err error) {
var v timeutil.Duration
err = v.UnmarshalText([]byte(s))
if err != nil {
return nil, fmt.Errorf("decoding dur: %w", err)
}
return dhcpv4.Duration(v.Duration), nil
}
// parseDHCPOptionVal parses a DHCP option value considering typ. For the del
// option the value string is ignored. The examples of possible value pairs:
//
// - hex 736f636b733a2f2f70726f78792e6578616d706c652e6f7267
// - ip 192.168.1.1
// - ips 192.168.1.1,192.168.1.2
// - text http://192.168.1.1/wpad.dat
// - del
// parseDHCPOptionUint parses a DHCP option as an unsigned integer. bitSize is
// expected to be 8 or 16.
func parseDHCPOptionUint(s string, bitSize int) (val dhcpv4.OptionValue, err error) {
var v uint64
v, err = strconv.ParseUint(s, 10, bitSize)
if err != nil {
return nil, fmt.Errorf("decoding u%d: %w", bitSize, err)
}
switch bitSize {
case 8:
return dhcpv4.OptionGeneric{Data: []byte{uint8(v)}}, nil
case 16:
return dhcpv4.Uint16(v), nil
default:
return nil, fmt.Errorf("unsupported size of integer %d", bitSize)
}
}
// parseDHCPOptionBool parses a DHCP option as a boolean value. See
// [strconv.ParseBool] for available values.
func parseDHCPOptionBool(s string) (val dhcpv4.OptionValue, err error) {
var v bool
v, err = strconv.ParseBool(s)
if err != nil {
return nil, fmt.Errorf("decoding bool: %w", err)
}
rawVal := [1]byte{}
if v {
rawVal[0] = 1
}
return dhcpv4.OptionGeneric{Data: rawVal[:]}, nil
}
// parseDHCPOptionVal parses a DHCP option value considering typ.
func parseDHCPOptionVal(typ, valStr string) (val dhcpv4.OptionValue, err error) {
switch typ {
case typBool:
val, err = parseDHCPOptionBool(valStr)
case typDel:
val = dhcpv4.OptionGeneric{Data: nil}
case typDur:
val, err = parseDHCPOptionDur(valStr)
case typHex:
val, err = parseDHCPOptionHex(valStr)
case typIP:
@ -91,9 +140,11 @@ func parseDHCPOptionVal(typ, valStr string) (val dhcpv4.OptionValue, err error)
case typIPs:
val, err = parseDHCPOptionIPs(valStr)
case typText:
val = parseDHCPOptionText(valStr)
case typDel:
val = dhcpv4.OptionGeneric{Data: nil}
val = dhcpv4.String(valStr)
case typU8:
val, err = parseDHCPOptionUint(valStr, 8)
case typU16:
val, err = parseDHCPOptionUint(valStr, 16)
default:
err = fmt.Errorf("unknown option type %q", typ)
}
@ -101,9 +152,19 @@ func parseDHCPOptionVal(typ, valStr string) (val dhcpv4.OptionValue, err error)
return val, err
}
// parseDHCPOption parses an option. See the documentation of
// parseDHCPOptionVal for more info.
func parseDHCPOption(s string) (opt dhcpv4.Option, err error) {
// parseDHCPOption parses an option. For the del option value is ignored. The
// examples of possible option strings:
//
// - 1 bool true
// - 2 del
// - 3 dur 2h5s
// - 4 hex 736f636b733a2f2f70726f78792e6578616d706c652e6f7267
// - 5 ip 192.168.1.1
// - 6 ips 192.168.1.1,192.168.1.2
// - 7 text http://192.168.1.1/wpad.dat
// - 8 u8 255
// - 9 u16 65535
func parseDHCPOption(s string) (code dhcpv4.OptionCode, val dhcpv4.OptionValue, err error) {
defer func() { err = errors.Annotate(err, "invalid option string %q: %w", s) }()
s = strings.TrimSpace(s)
@ -112,7 +173,7 @@ func parseDHCPOption(s string) (opt dhcpv4.Option, err error) {
var valStr string
if pl := len(parts); pl < 3 {
if pl < 2 || parts[1] != typDel {
return opt, errors.Error("bad option format")
return nil, nil, errors.Error("bad option format")
}
} else {
valStr = parts[2]
@ -121,85 +182,226 @@ func parseDHCPOption(s string) (opt dhcpv4.Option, err error) {
var code64 uint64
code64, err = strconv.ParseUint(parts[0], 10, 8)
if err != nil {
return opt, fmt.Errorf("parsing option code: %w", err)
return nil, nil, fmt.Errorf("parsing option code: %w", err)
}
val, err := parseDHCPOptionVal(parts[1], valStr)
val, err = parseDHCPOptionVal(parts[1], valStr)
if err != nil {
// Don't wrap an error since it's informative enough as is and there
// also the deferred annotation.
return opt, err
return nil, nil, err
}
return dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(code64),
Value: val,
}, nil
return dhcpv4.GenericOptionCode(code64), val, nil
}
// prepareOptions builds the set of DHCP options according to host requirements
// document and values from conf.
func prepareOptions(conf V4ServerConf) (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.
opts = dhcpv4.OptionsFromList(
func prepareOptions(conf V4ServerConf) (implicit, explicit dhcpv4.Options) {
// Set default values of host configuration parameters listed in Appendix A
// of RFC-2131.
implicit = dhcpv4.OptionsFromList(
// IP-Layer Per Host
dhcpv4.OptGeneric(dhcpv4.OptionNonLocalSourceRouting, []byte{0}),
// An Internet host that includes embedded gateway code MUST have a
// configuration switch to disable the gateway function, and this switch
// MUST default to the non-gateway mode.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.3.5.
dhcpv4.OptGeneric(dhcpv4.OptionIPForwarding, []byte{0x0}),
// Set the current recommended default time to live for the
// Internet Protocol which is 64, see
// https://datatracker.ietf.org/doc/html/rfc1700.
// A host that supports non-local source-routing MUST have a
// configurable switch to disable forwarding, and this switch MUST
// default to disabled.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.3.5.
dhcpv4.OptGeneric(dhcpv4.OptionNonLocalSourceRouting, []byte{0x0}),
// Do not set the Policy Filter Option since it only makes sense when
// the non-local source routing is enabled.
// The minimum legal value is 576.
//
// See https://datatracker.ietf.org/doc/html/rfc2132#section-4.4.
dhcpv4.Option{
Code: dhcpv4.OptionMaximumDatagramAssemblySize,
Value: dhcpv4.Uint16(576),
},
// Set the current recommended default time to live for the Internet
// Protocol which is 64.
//
// See https://www.iana.org/assignments/ip-parameters/ip-parameters.xhtml#ip-parameters-2.
dhcpv4.OptGeneric(dhcpv4.OptionDefaultIPTTL, []byte{0x40}),
dhcpv4.OptGeneric(dhcpv4.OptionPerformMaskDiscovery, []byte{0}),
dhcpv4.OptGeneric(dhcpv4.OptionMaskSupplier, []byte{0}),
dhcpv4.OptGeneric(dhcpv4.OptionPerformRouterDiscovery, []byte{1}),
// The all-routers address is preferred wherever possible, see
// https://datatracker.ietf.org/doc/html/rfc1256#section-5.1.
// For example, after the PTMU estimate is decreased, the timeout should
// be set to 10 minutes; once this timer expires and a larger MTU is
// attempted, the timeout can be set to a much smaller value.
//
// See https://datatracker.ietf.org/doc/html/rfc1191#section-6.6.
dhcpv4.Option{
Code: dhcpv4.OptionPathMTUAgingTimeout,
Value: dhcpv4.Duration(10 * time.Minute),
},
// There is a table describing the MTU values representing all major
// data-link technologies in use in the Internet so that each set of
// similar MTUs is associated with a plateau value equal to the lowest
// MTU in the group.
//
// See https://datatracker.ietf.org/doc/html/rfc1191#section-7.
dhcpv4.OptGeneric(dhcpv4.OptionPathMTUPlateauTable, []byte{
0x0, 0x44,
0x1, 0x28,
0x1, 0xFC,
0x3, 0xEE,
0x5, 0xD4,
0x7, 0xD2,
0x11, 0x0,
0x1F, 0xE6,
0x45, 0xFA,
}),
// IP-Layer Per Interface
// Since nearly all networks in the Internet currently support an MTU of
// 576 or greater, we strongly recommend the use of 576 for datagrams
// sent to non-local networks.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.3.3.
dhcpv4.Option{
Code: dhcpv4.OptionInterfaceMTU,
Value: dhcpv4.Uint16(576),
},
// Set the All Subnets Are Local Option to false since commonly the
// connected hosts aren't expected to be multihomed.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.3.3.
dhcpv4.OptGeneric(dhcpv4.OptionAllSubnetsAreLocal, []byte{0x00}),
// Set the Perform Mask Discovery Option to false to provide the subnet
// mask by options only.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.2.9.
dhcpv4.OptGeneric(dhcpv4.OptionPerformMaskDiscovery, []byte{0x00}),
// A system MUST NOT send an Address Mask Reply unless it is an
// authoritative agent for address masks. An authoritative agent may be
// a host or a gateway, but it MUST be explicitly configured as a
// address mask agent.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.2.9.
dhcpv4.OptGeneric(dhcpv4.OptionMaskSupplier, []byte{0x00}),
// Set the Perform Router Discovery Option to true as per Router
// Discovery Document.
//
// See https://datatracker.ietf.org/doc/html/rfc1256#section-5.1.
dhcpv4.OptGeneric(dhcpv4.OptionPerformRouterDiscovery, []byte{0x01}),
// The all-routers address is preferred wherever possible.
//
// See https://datatracker.ietf.org/doc/html/rfc1256#section-5.1.
dhcpv4.Option{
Code: dhcpv4.OptionRouterSolicitationAddress,
Value: dhcpv4.IP(netutil.IPv4allrouter()),
},
// Don't set the Static Routes Option since it should be set up by
// system administrator.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.3.1.2.
// A datagram with the destination address of limited broadcast will be
// received by every host on the connected physical network but will not
// be forwarded outside that network.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.1.3.
dhcpv4.OptBroadcastAddress(netutil.IPv4bcast()),
// Link-Layer Per Interface
dhcpv4.OptGeneric(dhcpv4.OptionTrailerEncapsulation, []byte{0}),
dhcpv4.OptGeneric(dhcpv4.OptionEthernetEncapsulation, []byte{0}),
// If the system does not dynamically negotiate use of the trailer
// protocol on a per-destination basis, the default configuration MUST
// disable the protocol.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-2.3.1.
dhcpv4.OptGeneric(dhcpv4.OptionTrailerEncapsulation, []byte{0x00}),
// For proxy ARP situations, the timeout needs to be on the order of a
// minute.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-2.3.2.1.
dhcpv4.Option{
Code: dhcpv4.OptionArpCacheTimeout,
Value: dhcpv4.Duration(time.Minute),
},
// An Internet host that implements sending both the RFC-894 and the
// RFC-1042 encapsulations MUST provide a configuration switch to select
// which is sent, and this switch MUST default to RFC-894.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-2.3.3.
dhcpv4.OptGeneric(dhcpv4.OptionEthernetEncapsulation, []byte{0x00}),
// TCP Per Host
// A fixed value must be at least big enough for the Internet diameter,
// i.e., the longest possible path. A reasonable value is about twice
// the diameter, to allow for continued Internet growth.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.1.7.
dhcpv4.Option{
Code: dhcpv4.OptionDefaulTCPTTL,
Value: dhcpv4.Duration(60 * time.Second),
},
// The interval MUST be configurable and MUST default to no less than
// two hours.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-4.2.3.6.
dhcpv4.Option{
Code: dhcpv4.OptionTCPKeepaliveInterval,
Value: dhcpv4.Duration(0),
Value: dhcpv4.Duration(2 * time.Hour),
},
dhcpv4.OptGeneric(dhcpv4.OptionTCPKeepaliveGarbage, []byte{0}),
// Unfortunately, some misbehaved TCP implementations fail to respond to
// a probe segment unless it contains data.
//
// See https://datatracker.ietf.org/doc/html/rfc1122#section-4.2.3.6.
dhcpv4.OptGeneric(dhcpv4.OptionTCPKeepaliveGarbage, []byte{0x01}),
// Values From Configuration
// Set the Router Option to working subnet's IP since it's initialized
// with the address of the gateway.
dhcpv4.OptRouter(conf.subnet.IP),
dhcpv4.OptSubnetMask(conf.subnet.Mask),
)
// Set values for explicitly configured options.
explicit = dhcpv4.Options{}
for i, o := range conf.Options {
opt, err := parseDHCPOption(o)
code, val, err := parseDHCPOption(o)
if err != nil {
log.Error("dhcpv4: bad option string at index %d: %s", i, err)
continue
}
opts.Update(opt)
explicit.Update(dhcpv4.Option{Code: code, Value: val})
// Remove those from the implicit options.
delete(implicit, code.Code())
}
return opts
log.Debug("dhcpv4: implicit options:\n%s", implicit.Summary(nil))
log.Debug("dhcpv4: explicit options:\n%s", explicit.Summary(nil))
if len(explicit) == 0 {
explicit = nil
}
return implicit, explicit
}

256
internal/dhcpd/options_unix_test.go
View File

@ -7,7 +7,9 @@ import (
"fmt"
"net"
"testing"
"time"
"github.com/AdguardTeam/golibs/netutil"
"github.com/AdguardTeam/golibs/testutil"
"github.com/insomniacslk/dhcp/dhcpv4"
"github.com/stretchr/testify/assert"
@ -17,150 +19,199 @@ func TestParseOpt(t *testing.T) {
testCases := []struct {
name string
in string
wantOpt dhcpv4.Option
wantCode dhcpv4.OptionCode
wantVal dhcpv4.OptionValue
wantErrMsg string
}{{
name: "hex_success",
in: "6 hex c0a80101c0a80102",
wantOpt: dhcpv4.OptGeneric(
dhcpv4.GenericOptionCode(6),
[]byte{
0xC0, 0xA8, 0x01, 0x01,
0xC0, 0xA8, 0x01, 0x02,
},
),
name: "hex_success",
in: "6 hex c0a80101c0a80102",
wantCode: dhcpv4.GenericOptionCode(6),
wantVal: dhcpv4.OptionGeneric{Data: []byte{
0xC0, 0xA8, 0x01, 0x01,
0xC0, 0xA8, 0x01, 0x02,
}},
wantErrMsg: "",
}, {
name: "ip_success",
in: "6 ip 1.2.3.4",
wantOpt: dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(6),
Value: dhcpv4.IP(net.IP{0x01, 0x02, 0x03, 0x04}),
},
name: "ip_success",
in: "6 ip 1.2.3.4",
wantCode: dhcpv4.GenericOptionCode(6),
wantVal: dhcpv4.IP(net.IP{0x01, 0x02, 0x03, 0x04}),
wantErrMsg: "",
}, {
name: "ip_fail_v6",
in: "6 ip ::1234",
wantOpt: dhcpv4.Option{},
wantErrMsg: "invalid option string \"6 ip ::1234\": bad ipv4 address \"::1234\"",
}, {
name: "ips_success",
in: "6 ips 192.168.1.1,192.168.1.2",
wantOpt: dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(6),
Value: dhcpv4.IPs([]net.IP{
{0xC0, 0xA8, 0x01, 0x01},
{0xC0, 0xA8, 0x01, 0x02},
}),
},
name: "ips_success",
in: "6 ips 192.168.1.1,192.168.1.2",
wantCode: dhcpv4.GenericOptionCode(6),
wantVal: dhcpv4.IPs([]net.IP{
{0xC0, 0xA8, 0x01, 0x01},
{0xC0, 0xA8, 0x01, 0x02},
}),
wantErrMsg: "",
}, {
name: "text_success",
in: "252 text http://192.168.1.1/",
wantOpt: dhcpv4.OptGeneric(
dhcpv4.GenericOptionCode(252),
[]byte("http://192.168.1.1/"),
),
name: "text_success",
in: "252 text http://192.168.1.1/",
wantCode: dhcpv4.GenericOptionCode(252),
wantVal: dhcpv4.String("http://192.168.1.1/"),
wantErrMsg: "",
}, {
name: "del_success",
in: "61 del",
wantOpt: dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(dhcpv4.OptionClientIdentifier),
Value: dhcpv4.OptionGeneric{Data: nil},
},
name: "del_success",
in: "61 del",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionClientIdentifier),
wantVal: dhcpv4.OptionGeneric{Data: nil},
wantErrMsg: "",
}, {
name: "bool_success",
in: "19 bool true",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionIPForwarding),
wantVal: dhcpv4.OptionGeneric{Data: []byte{0x01}},
wantErrMsg: "",
}, {
name: "bool_success_false",
in: "19 bool F",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionIPForwarding),
wantVal: dhcpv4.OptionGeneric{Data: []byte{0x00}},
wantErrMsg: "",
}, {
name: "dur_success",
in: "24 dur 2h5s",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionPathMTUAgingTimeout),
wantVal: dhcpv4.Duration(2*time.Hour + 5*time.Second),
wantErrMsg: "",
}, {
name: "u8_success",
in: "23 u8 64",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionDefaultIPTTL),
wantVal: dhcpv4.OptionGeneric{Data: []byte{0x40}},
wantErrMsg: "",
}, {
name: "u16_success",
in: "22 u16 1234",
wantCode: dhcpv4.GenericOptionCode(dhcpv4.OptionMaximumDatagramAssemblySize),
wantVal: dhcpv4.Uint16(1234),
wantErrMsg: "",
}, {
name: "bad_parts",
in: "6 ip",
wantOpt: dhcpv4.Option{},
wantCode: nil,
wantVal: nil,
wantErrMsg: `invalid option string "6 ip": bad option format`,
}, {
name: "bad_code",
in: "256 ip 1.1.1.1",
wantOpt: dhcpv4.Option{},
name: "bad_code",
in: "256 ip 1.1.1.1",
wantCode: nil,
wantVal: nil,
wantErrMsg: `invalid option string "256 ip 1.1.1.1": parsing option code: ` +
`strconv.ParseUint: parsing "256": value out of range`,
}, {
name: "bad_type",
in: "6 bad 1.1.1.1",
wantOpt: dhcpv4.Option{},
wantCode: nil,
wantVal: nil,
wantErrMsg: `invalid option string "6 bad 1.1.1.1": unknown option type "bad"`,
}, {
name: "hex_error",
in: "6 hex ZZZ",
wantOpt: dhcpv4.Option{},
name: "hex_error",
in: "6 hex ZZZ",
wantCode: nil,
wantVal: nil,
wantErrMsg: `invalid option string "6 hex ZZZ": decoding hex: ` +
`encoding/hex: invalid byte: U+005A 'Z'`,
}, {
name: "ip_error",
in: "6 ip 1.2.3.x",
wantOpt: dhcpv4.Option{},
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"6 ip 1.2.3.x\": bad ipv4 address \"1.2.3.x\"",
}, {
name: "ips_error",
in: "6 ips 192.168.1.1,192.168.1.x",
wantOpt: dhcpv4.Option{},
name: "ip_error_v6",
in: "6 ip ::1234",
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"6 ip ::1234\": bad ipv4 address \"::1234\"",
}, {
name: "ips_error",
in: "6 ips 192.168.1.1,192.168.1.x",
wantCode: nil,
wantVal: nil,
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\"",
}, {
name: "bool_error",
in: "19 bool yes",
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"19 bool yes\": decoding bool: " +
"strconv.ParseBool: parsing \"yes\": invalid syntax",
}, {
name: "dur_error",
in: "24 dur 3y",
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"24 dur 3y\": decoding dur: " +
"unmarshaling duration: time: unknown unit \"y\" in duration \"3y\"",
}, {
name: "u8_error",
in: "23 u8 256",
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"23 u8 256\": decoding u8: " +
"strconv.ParseUint: parsing \"256\": value out of range",
}, {
name: "u16_error",
in: "23 u16 65536",
wantCode: nil,
wantVal: nil,
wantErrMsg: "invalid option string \"23 u16 65536\": decoding u16: " +
"strconv.ParseUint: parsing \"65536\": value out of range",
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
opt, err := parseDHCPOption(tc.in)
code, val, err := parseDHCPOption(tc.in)
testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
// assert.Equal(t, tc.wantOpt.Code.Code(), opt.Code.Code())
// assert.Equal(t, tc.wantOpt.Value.ToBytes(), opt.Value.ToBytes())
assert.Equal(t, tc.wantOpt, opt)
assert.Equal(t, tc.wantCode, code)
assert.Equal(t, tc.wantVal, val)
})
}
}
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
checks dhcpv4.Options
opts []string
name string
wantExplicit dhcpv4.Options
opts []string
}{{
name: "all_default",
checks: allDefault,
opts: nil,
name: "all_default",
wantExplicit: nil,
opts: nil,
}, {
name: "configured_ip",
checks: dhcpv4.Options{
dhcpv4.OptionBroadcastAddress.Code(): oneIP,
},
wantExplicit: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(oneIP),
),
opts: []string{
fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, oneIP),
},
}, {
name: "configured_ips",
checks: dhcpv4.Options{
dhcpv4.OptionDomainNameServer.Code(): append(oneIP, otherIP...),
},
wantExplicit: dhcpv4.OptionsFromList(
dhcpv4.Option{
Code: dhcpv4.OptionDomainNameServer,
Value: dhcpv4.IPs{oneIP, otherIP},
},
),
opts: []string{
fmt.Sprintf("%d ips %s,%s", dhcpv4.OptionDomainNameServer, oneIP, otherIP),
},
}, {
name: "configured_bad",
checks: allDefault,
name: "configured_bad",
wantExplicit: nil,
opts: []string{
"19 bool yes",
"24 dur 3y",
"23 u8 256",
"23 u16 65536",
"20 hex",
"23 hex abc",
"32 ips 1,2,3,4",
@ -168,26 +219,29 @@ func TestPrepareOptions(t *testing.T) {
},
}, {
name: "configured_del",
checks: dhcpv4.Options{
dhcpv4.OptionBroadcastAddress.Code(): nil,
},
wantExplicit: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(nil),
),
opts: []string{
"28 del",
},
}, {
name: "rewritten_del",
checks: dhcpv4.Options{
dhcpv4.OptionBroadcastAddress.Code(): []byte{255, 255, 255, 255},
},
wantExplicit: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(netutil.IPv4bcast()),
),
opts: []string{
"28 del",
"28 ip 255.255.255.255",
},
}, {
name: "configured_and_del",
checks: dhcpv4.Options{
123: []byte("cba"),
},
wantExplicit: dhcpv4.OptionsFromList(
dhcpv4.Option{
Code: dhcpv4.OptionGeoConf,
Value: dhcpv4.String("cba"),
},
),
opts: []string{
"123 text abc",
"123 del",
@ -197,18 +251,16 @@ func TestPrepareOptions(t *testing.T) {
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
if tc.name == "configured_del" {
assert.True(t, true)
}
opts := prepareOptions(V4ServerConf{
implicit, explicit := prepareOptions(V4ServerConf{
// Just to avoid nil pointer dereference.
subnet: &net.IPNet{},
Options: tc.opts,
})
for c, v := range tc.checks {
val := opts.Get(dhcpv4.GenericOptionCode(c))
assert.Lenf(t, val, len(v), "Code: %v", c)
assert.Equal(t, v, val)
assert.Equal(t, tc.wantExplicit, explicit)
for c := range explicit {
assert.NotContains(t, implicit, c)
}
})
}

72
internal/dhcpd/v4.go
View File

@ -33,6 +33,17 @@ type v4Server struct {
conf V4ServerConf
srv *server4.Server
// implicitOpts are the options listed in Appendix A of RFC 2131 initialized
// with default values. It must not have intersections with [explicitOpts].
implicitOpts dhcpv4.Options
// explicitOpts are the options parsed from the configuration. It must not
// have intersections with [implicitOpts].
explicitOpts dhcpv4.Options
// leasesLock protects leases, leaseHosts, and leasedOffsets.
leasesLock sync.Mutex
// leasedOffsets contains offsets from conf.ipRange.start that have been
// leased.
leasedOffsets *bitSet
@ -42,12 +53,6 @@ type v4Server struct {
// leases contains all dynamic and static leases.
leases []*Lease
// leasesLock protects leases, leaseHosts, and leasedOffsets.
leasesLock sync.Mutex
// options holds predefined DHCP options to return to clients.
options dhcpv4.Options
}
// WriteDiskConfig4 - write configuration
@ -999,34 +1004,42 @@ func (s *v4Server) handle(req, resp *dhcpv4.DHCPv4) int {
resp.YourIPAddr = netutil.CloneIP(l.IP)
}
s.updateOptions(req, resp)
return 1
}
// updateOptions updates the options of the response in accordance with the
// request and RFC 2131.
//
// See https://datatracker.ietf.org/doc/html/rfc2131#section-4.3.1.
func (s *v4Server) updateOptions(req, resp *dhcpv4.DHCPv4) {
// 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))
// Delete options explicitly configured to be removed.
for code := range resp.Options {
if val, ok := s.options[code]; ok && val == nil {
// If the server recognizes the parameter as a parameter defined in the Host
// Requirements Document, the server MUST include the default value for that
// parameter.
for _, code := range req.ParameterRequestList() {
if val := s.implicitOpts.Get(code); val != nil {
resp.UpdateOption(dhcpv4.OptGeneric(code, val))
}
}
// If the server has been explicitly configured with a default value for the
// parameter or the parameter has a non-default value on the client's
// subnet, the server MUST include that value in an appropriate option.
for code, val := range s.explicitOpts {
if val != nil {
resp.Options[code] = val
} else {
// Delete options explicitly configured to be removed.
delete(resp.Options, code)
}
}
// 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 val := s.options.Get(code); val != nil {
resp.UpdateOption(dhcpv4.Option{
Code: code,
Value: dhcpv4.OptionGeneric{Data: s.options.Get(code)},
})
}
}
return 1
}
// client(0.0.0.0:68) -> (Request:ClientMAC,Type=Discover,ClientID,ReqIP,HostName) -> server(255.255.255.255:67)
@ -1151,8 +1164,11 @@ func (s *v4Server) Start() (err error) {
}
// Update the value of Domain Name Server option separately from others if
// not assigned yet since its value is available only at server's start.
if !s.options.Has(dhcpv4.OptionDomainNameServer) {
s.options.Update(dhcpv4.OptDNS(dnsIPAddrs...))
//
// TODO(e.burkov): Initialize as implicit option with the rest of default
// options when it will be possible to do before the call to Start.
if !s.explicitOpts.Has(dhcpv4.OptionDomainNameServer) {
s.implicitOpts.Update(dhcpv4.OptDNS(dnsIPAddrs...))
}
s.conf.dnsIPAddrs = dnsIPAddrs
@ -1279,7 +1295,7 @@ func v4Create(conf V4ServerConf) (srv DHCPServer, err error) {
s.conf.leaseTime = time.Second * time.Duration(conf.LeaseDuration)
}
s.options = prepareOptions(s.conf)
s.implicitOpts, s.explicitOpts = prepareOptions(s.conf)
return s, nil
}

112
internal/dhcpd/v4_test.go
View File

@ -11,6 +11,7 @@ import (
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
"github.com/AdguardTeam/golibs/netutil"
"github.com/AdguardTeam/golibs/stringutil"
"github.com/AdguardTeam/golibs/testutil"
"github.com/insomniacslk/dhcp/dhcpv4"
@ -346,7 +347,7 @@ func TestV4Server_handle_optionsPriority(t *testing.T) {
}
conf.Options = []string{b.String()}
} else {
defer func() { s.options.Update(dhcpv4.OptDNS(defaultIP)) }()
defer func() { s.implicitOpts.Update(dhcpv4.OptDNS(defaultIP)) }()
}
ss, err := v4Create(conf)
@ -402,6 +403,111 @@ func TestV4Server_handle_optionsPriority(t *testing.T) {
})
}
func TestV4Server_updateOptions(t *testing.T) {
testIP := net.IP{1, 2, 3, 4}
dontWant := func(c dhcpv4.OptionCode) (opt dhcpv4.Option) {
return dhcpv4.OptGeneric(c, nil)
}
testCases := []struct {
name string
wantOpts dhcpv4.Options
reqMods []dhcpv4.Modifier
confOpts []string
}{{
name: "requested_default",
wantOpts: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(netutil.IPv4bcast()),
),
reqMods: []dhcpv4.Modifier{
dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress),
},
confOpts: nil,
}, {
name: "requested_non-default",
wantOpts: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(testIP),
),
reqMods: []dhcpv4.Modifier{
dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress),
},
confOpts: []string{
fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP),
},
}, {
name: "non-requested_default",
wantOpts: dhcpv4.OptionsFromList(
dontWant(dhcpv4.OptionBroadcastAddress),
),
reqMods: nil,
confOpts: nil,
}, {
name: "non-requested_non-default",
wantOpts: dhcpv4.OptionsFromList(
dhcpv4.OptBroadcastAddress(testIP),
),
reqMods: nil,
confOpts: []string{
fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP),
},
}, {
name: "requested_deleted",
wantOpts: dhcpv4.OptionsFromList(
dontWant(dhcpv4.OptionBroadcastAddress),
),
reqMods: []dhcpv4.Modifier{
dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress),
},
confOpts: []string{
fmt.Sprintf("%d del", dhcpv4.OptionBroadcastAddress),
},
}, {
name: "requested_non-default_deleted",
wantOpts: dhcpv4.OptionsFromList(
dontWant(dhcpv4.OptionBroadcastAddress),
),
reqMods: []dhcpv4.Modifier{
dhcpv4.WithRequestedOptions(dhcpv4.OptionBroadcastAddress),
},
confOpts: []string{
fmt.Sprintf("%d ip %s", dhcpv4.OptionBroadcastAddress, testIP),
fmt.Sprintf("%d del", dhcpv4.OptionBroadcastAddress),
},
}}
for _, tc := range testCases {
req, err := dhcpv4.New(tc.reqMods...)
require.NoError(t, err)
resp, err := dhcpv4.NewReplyFromRequest(req)
require.NoError(t, err)
conf := defaultV4ServerConf()
conf.Options = tc.confOpts
s, err := v4Create(conf)
require.NoError(t, err)
require.IsType(t, (*v4Server)(nil), s)
s4, _ := s.(*v4Server)
t.Run(tc.name, func(t *testing.T) {
s4.updateOptions(req, resp)
for c, v := range tc.wantOpts {
if v == nil {
assert.NotContains(t, resp.Options, c)
continue
}
assert.Equal(t, v, resp.Options.Get(dhcpv4.GenericOptionCode(c)))
}
})
}
}
func TestV4StaticLease_Get(t *testing.T) {
sIface := defaultSrv(t)
@ -409,7 +515,7 @@ func TestV4StaticLease_Get(t *testing.T) {
require.True(t, ok)
s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}}
s.options.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
s.implicitOpts.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
l := &Lease{
Hostname: "static-1.local",
@ -498,7 +604,7 @@ func TestV4DynamicLease_Get(t *testing.T) {
require.True(t, ok)
s.conf.dnsIPAddrs = []net.IP{{192, 168, 10, 1}}
s.options.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
s.implicitOpts.Update(dhcpv4.OptDNS(s.conf.dnsIPAddrs...))
var req, resp *dhcpv4.DHCPv4
mac := net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}

4
scripts/make/go-lint.sh
View File

@ -220,9 +220,9 @@ exit_on_output gofumpt --extra -e -l .
"$GO" vet ./...
# Apply more lax standards to the code we haven't properly refactored yet.
gocyclo --over 17 ./internal/dhcpd ./internal/querylog/
gocyclo --over 17 ./internal/querylog/
gocyclo --over 16 ./internal/dnsforward/
gocyclo --over 15 ./internal/home/
gocyclo --over 15 ./internal/home/ ./internal/dhcpd
gocyclo --over 13 ./internal/filtering/
# Apply stricter standards to new or somewhat refactored code.