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all: sync with master

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This commit is contained in:
Ainar Garipov
2022-09-07 18:03:18 +03:00
parent d23da1b757
commit faf2b32389
108 changed files with 2925 additions and 2390 deletions
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393
internal/dhcpd/options_unix.go
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@@ -9,26 +9,31 @@ 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 (
hexTyp = "hex"
ipTyp = "ip"
ipsTyp = "ips"
textTyp = "text"
typDel = "del"
typBool = "bool"
typDur = "dur"
typHex = "hex"
typIP = "ip"
typIPs = "ips"
typText = "text"
typU8 = "u8"
typU16 = "u16"
)
// parseDHCPOptionHex parses a DHCP option as a hex-encoded string. For
// example:
//
// 252 hex 736f636b733a2f2f70726f78792e6578616d706c652e6f7267
//
// parseDHCPOptionHex parses a DHCP option as a hex-encoded string.
func parseDHCPOptionHex(s string) (val dhcpv4.OptionValue, err error) {
var data []byte
data, err = hex.DecodeString(s)
@@ -39,15 +44,12 @@ func parseDHCPOptionHex(s string) (val dhcpv4.OptionValue, err error) {
return dhcpv4.OptionGeneric{Data: data}, nil
}
// parseDHCPOptionIP parses a DHCP option as a single IP address. For example:
//
// 6 ip 192.168.1.1
//
// parseDHCPOptionIP parses a DHCP option as a single IP address.
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 {
@@ -58,133 +60,348 @@ func parseDHCPOptionIP(s string) (val dhcpv4.OptionValue, err error) {
}
// 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
//
// 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. For example:
//
// 252 text http://192.168.1.1/wpad.dat
//
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
}
// parseDHCPOption parses an option. See the documentation of parseDHCPOption*
// for more info.
func parseDHCPOption(s string) (opt dhcpv4.Option, err error) {
// 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:
val, err = parseDHCPOptionIP(valStr)
case typIPs:
val, err = parseDHCPOptionIPs(valStr)
case typText:
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)
}
return val, err
}
// 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)
parts := strings.SplitN(s, " ", 3)
if len(parts) < 3 {
return opt, errors.Error("need at least three fields")
var valStr string
if pl := len(parts); pl < 3 {
if pl < 2 || parts[1] != typDel {
return nil, nil, errors.Error("bad option format")
}
} else {
valStr = parts[2]
}
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)
return nil, nil, fmt.Errorf("parsing option code: %w", err)
}
val, err = parseDHCPOptionVal(parts[1], valStr)
if err != nil {
return opt, err
// Don't wrap an error since it's informative enough as is and there
// also the deferred annotation.
return nil, nil, err
}
return dhcpv4.Option{
Code: dhcpv4.GenericOptionCode(code64),
Value: optVal,
}, 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.Options{
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.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},
// 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}),
// 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}),
// 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
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(): netutil.IPv4allrouter(),
dhcpv4.OptionBroadcastAddress.Code(): netutil.IPv4bcast(),
// 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.OptionTrailerEncapsulation.Code(): []byte{0},
dhcpv4.OptionEthernetEncapsulation.Code(): []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
dhcpv4.OptionTCPKeepaliveInterval.Code(): dhcpv4.Duration(0).ToBytes(),
dhcpv4.OptionTCPKeepaliveGarbage.Code(): []byte{0},
// 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(2 * time.Hour),
},
// 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
dhcpv4.OptionRouter.Code(): netutil.CloneIP(conf.subnet.IP),
dhcpv4.OptionSubnetMask.Code(): dhcpv4.IPMask(conf.subnet.Mask).ToBytes(),
}
// 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
}