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authorGhanan Gowripalan <ghanan@google.com>2021-03-16 11:07:02 -0700
committergVisor bot <gvisor-bot@google.com>2021-03-16 11:09:26 -0700
commit68065d1ceb589b7ea1d3e4b3b067fb8772e30760 (patch)
treef3017f52fba725114b913cf893fcdcb6678415de
parentebd7c1b889e5d212f4a694d3addbada241936e8e (diff)
Detect looped-back NDP DAD messages
...as per RFC 7527. If a looped-back DAD message is received, do not fail DAD since our own DAD message does not indicate that a neighbor has the address assigned. Test: ndp_test.TestDADResolveLoopback PiperOrigin-RevId: 363224288
-rw-r--r--pkg/tcpip/checker/checker.go7
-rw-r--r--pkg/tcpip/header/ndp_options.go40
-rw-r--r--pkg/tcpip/header/ndp_test.go679
-rw-r--r--pkg/tcpip/header/ndpoptionidentifier_string.go14
-rw-r--r--pkg/tcpip/network/arp/arp.go13
-rw-r--r--pkg/tcpip/network/internal/ip/duplicate_address_detection.go139
-rw-r--r--pkg/tcpip/network/internal/ip/duplicate_address_detection_test.go124
-rw-r--r--pkg/tcpip/network/ipv6/icmp.go55
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go89
-rw-r--r--pkg/tcpip/network/ipv6/mld_test.go18
-rw-r--r--pkg/tcpip/network/ipv6/ndp.go14
-rw-r--r--pkg/tcpip/network/ipv6/ndp_test.go72
-rw-r--r--pkg/tcpip/stack/ndp_test.go79
-rw-r--r--pkg/tcpip/stack/stack.go18
14 files changed, 882 insertions, 479 deletions
diff --git a/pkg/tcpip/checker/checker.go b/pkg/tcpip/checker/checker.go
index fc622b246..fef065b05 100644
--- a/pkg/tcpip/checker/checker.go
+++ b/pkg/tcpip/checker/checker.go
@@ -1287,6 +1287,13 @@ func ndpOptions(t *testing.T, optsBuf header.NDPOptions, opts []header.NDPOption
} else if got, want := gotOpt.EthernetAddress(), wantOpt.EthernetAddress(); got != want {
t.Errorf("got EthernetAddress() = %s at index %d, want = %s", got, i, want)
}
+ case header.NDPNonceOption:
+ gotOpt, ok := opt.(header.NDPNonceOption)
+ if !ok {
+ t.Errorf("got type = %T at index = %d; want = %T", opt, i, wantOpt)
+ } else if diff := cmp.Diff(wantOpt.Nonce(), gotOpt.Nonce()); diff != "" {
+ t.Errorf("nonce mismatch (-want +got):\n%s", diff)
+ }
default:
t.Fatalf("checker not implemented for expected NDP option: %T", wantOpt)
}
diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go
index 554242f0c..5deae465c 100644
--- a/pkg/tcpip/header/ndp_options.go
+++ b/pkg/tcpip/header/ndp_options.go
@@ -42,13 +42,17 @@ const (
// option, as per RFC 4861 section 4.6.2.
NDPPrefixInformationType NDPOptionIdentifier = 3
+ // NDPNonceOptionType is the type of the Nonce option, as per
+ // RFC 3971 section 5.3.2.
+ NDPNonceOptionType NDPOptionIdentifier = 14
+
// NDPRecursiveDNSServerOptionType is the type of the Recursive DNS
// Server option, as per RFC 8106 section 5.1.
NDPRecursiveDNSServerOptionType NDPOptionIdentifier = 25
// NDPDNSSearchListOptionType is the type of the DNS Search List option,
// as per RFC 8106 section 5.2.
- NDPDNSSearchListOptionType = 31
+ NDPDNSSearchListOptionType NDPOptionIdentifier = 31
)
const (
@@ -231,6 +235,9 @@ func (i *NDPOptionIterator) Next() (NDPOption, bool, error) {
case NDPTargetLinkLayerAddressOptionType:
return NDPTargetLinkLayerAddressOption(body), false, nil
+ case NDPNonceOptionType:
+ return NDPNonceOption(body), false, nil
+
case NDPPrefixInformationType:
// Make sure the length of a Prefix Information option
// body is ndpPrefixInformationLength, as per RFC 4861
@@ -416,6 +423,37 @@ func (b NDPOptionsSerializer) Length() int {
return l
}
+// NDPNonceOption is the NDP Nonce Option as defined by RFC 3971 section 5.3.2.
+//
+// It is the first X bytes following the NDP option's Type and Length field
+// where X is the value in Length multiplied by lengthByteUnits - 2 bytes.
+type NDPNonceOption []byte
+
+// Type implements NDPOption.
+func (o NDPNonceOption) Type() NDPOptionIdentifier {
+ return NDPNonceOptionType
+}
+
+// Length implements NDPOption.
+func (o NDPNonceOption) Length() int {
+ return len(o)
+}
+
+// serializeInto implements NDPOption.
+func (o NDPNonceOption) serializeInto(b []byte) int {
+ return copy(b, o)
+}
+
+// String implements fmt.Stringer.
+func (o NDPNonceOption) String() string {
+ return fmt.Sprintf("%T(%x)", o, []byte(o))
+}
+
+// Nonce returns the nonce value this option holds.
+func (o NDPNonceOption) Nonce() []byte {
+ return []byte(o)
+}
+
// NDPSourceLinkLayerAddressOption is the NDP Source Link Layer Option
// as defined by RFC 4861 section 4.6.1.
//
diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go
index dc4591253..bfc73e245 100644
--- a/pkg/tcpip/header/ndp_test.go
+++ b/pkg/tcpip/header/ndp_test.go
@@ -16,6 +16,7 @@ package header
import (
"bytes"
+ "encoding/binary"
"errors"
"fmt"
"io"
@@ -192,90 +193,6 @@ func TestNDPSourceLinkLayerAddressOptionEthernetAddress(t *testing.T) {
}
}
-// TestNDPSourceLinkLayerAddressOptionSerialize tests serializing a
-// NDPSourceLinkLayerAddressOption.
-func TestNDPSourceLinkLayerAddressOptionSerialize(t *testing.T) {
- tests := []struct {
- name string
- buf []byte
- expectedBuf []byte
- addr tcpip.LinkAddress
- }{
- {
- "Ethernet",
- make([]byte, 8),
- []byte{1, 1, 1, 2, 3, 4, 5, 6},
- "\x01\x02\x03\x04\x05\x06",
- },
- {
- "Padding",
- []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
- []byte{1, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
- "\x01\x02\x03\x04\x05\x06\x07\x08",
- },
- {
- "Empty",
- nil,
- nil,
- "",
- },
- }
-
- for _, test := range tests {
- t.Run(test.name, func(t *testing.T) {
- opts := NDPOptions(test.buf)
- serializer := NDPOptionsSerializer{
- NDPSourceLinkLayerAddressOption(test.addr),
- }
- if got, want := int(serializer.Length()), len(test.expectedBuf); got != want {
- t.Fatalf("got Length = %d, want = %d", got, want)
- }
- opts.Serialize(serializer)
- if !bytes.Equal(test.buf, test.expectedBuf) {
- t.Fatalf("got b = %d, want = %d", test.buf, test.expectedBuf)
- }
-
- it, err := opts.Iter(true)
- if err != nil {
- t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
- }
-
- if len(test.expectedBuf) > 0 {
- next, done, err := it.Next()
- if err != nil {
- t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if done {
- t.Fatal("got Next = (_, true, _), want = (_, false, _)")
- }
- if got := next.Type(); got != NDPSourceLinkLayerAddressOptionType {
- t.Fatalf("got Type = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType)
- }
- sll := next.(NDPSourceLinkLayerAddressOption)
- if got, want := []byte(sll), test.expectedBuf[2:]; !bytes.Equal(got, want) {
- t.Fatalf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
- }
-
- if got, want := sll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want {
- t.Errorf("got sll.EthernetAddress = %s, want = %s", got, want)
- }
- }
-
- // Iterator should not return anything else.
- next, done, err := it.Next()
- if err != nil {
- t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if !done {
- t.Error("got Next = (_, false, _), want = (_, true, _)")
- }
- if next != nil {
- t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
- }
- })
- }
-}
-
// TestNDPTargetLinkLayerAddressOptionEthernetAddress tests getting the
// Ethernet address from an NDPTargetLinkLayerAddressOption.
func TestNDPTargetLinkLayerAddressOptionEthernetAddress(t *testing.T) {
@@ -311,32 +228,309 @@ func TestNDPTargetLinkLayerAddressOptionEthernetAddress(t *testing.T) {
}
}
-// TestNDPTargetLinkLayerAddressOptionSerialize tests serializing a
-// NDPTargetLinkLayerAddressOption.
-func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
+func TestOpts(t *testing.T) {
+ const optionHeaderLen = 2
+
+ checkNonce := func(expectedNonce []byte) func(*testing.T, NDPOption) {
+ return func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPNonceOptionType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPNonceOptionType)
+ }
+ nonce, ok := opt.(NDPNonceOption)
+ if !ok {
+ t.Fatalf("got nonce = %T, want = NDPNonceOption", opt)
+ }
+ if diff := cmp.Diff(expectedNonce, nonce.Nonce()); diff != "" {
+ t.Errorf("nonce mismatch (-want +got):\n%s", diff)
+ }
+ }
+ }
+
+ checkTLL := func(expectedAddr tcpip.LinkAddress) func(*testing.T, NDPOption) {
+ return func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPTargetLinkLayerAddressOptionType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPTargetLinkLayerAddressOptionType)
+ }
+ tll, ok := opt.(NDPTargetLinkLayerAddressOption)
+ if !ok {
+ t.Fatalf("got tll = %T, want = NDPTargetLinkLayerAddressOption", opt)
+ }
+ if got, want := tll.EthernetAddress(), expectedAddr; got != want {
+ t.Errorf("got tll.EthernetAddress = %s, want = %s", got, want)
+ }
+ }
+ }
+
+ checkSLL := func(expectedAddr tcpip.LinkAddress) func(*testing.T, NDPOption) {
+ return func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPSourceLinkLayerAddressOptionType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType)
+ }
+ sll, ok := opt.(NDPSourceLinkLayerAddressOption)
+ if !ok {
+ t.Fatalf("got sll = %T, want = NDPSourceLinkLayerAddressOption", opt)
+ }
+ if got, want := sll.EthernetAddress(), expectedAddr; got != want {
+ t.Errorf("got sll.EthernetAddress = %s, want = %s", got, want)
+ }
+ }
+ }
+
+ const validLifetimeSeconds = 16909060
+ const address = tcpip.Address("\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18")
+
+ expectedRDNSSBytes := [...]byte{
+ // Type, Length
+ 25, 3,
+
+ // Reserved
+ 0, 0,
+
+ // Lifetime
+ 1, 2, 4, 8,
+
+ // Address
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ }
+ binary.BigEndian.PutUint32(expectedRDNSSBytes[4:], validLifetimeSeconds)
+ if n := copy(expectedRDNSSBytes[8:], address); n != IPv6AddressSize {
+ t.Fatalf("got copy(...) = %d, want = %d", n, IPv6AddressSize)
+ }
+ // Update reserved fields to non zero values to make sure serializing sets
+ // them to zero.
+ rdnssBytes := expectedRDNSSBytes
+ rdnssBytes[1] = 1
+ rdnssBytes[2] = 2
+
+ const searchListPaddingBytes = 3
+ const domainName = "abc.abcd.e"
+ expectedSearchListBytes := [...]byte{
+ // Type, Length
+ 31, 3,
+
+ // Reserved
+ 0, 0,
+
+ // Lifetime
+ 1, 0, 0, 0,
+
+ // Domain names
+ 3, 'a', 'b', 'c',
+ 4, 'a', 'b', 'c', 'd',
+ 1, 'e',
+ 0,
+ 0, 0, 0, 0,
+ }
+ binary.BigEndian.PutUint32(expectedSearchListBytes[4:], validLifetimeSeconds)
+ // Update reserved fields to non zero values to make sure serializing sets
+ // them to zero.
+ searchListBytes := expectedSearchListBytes
+ searchListBytes[2] = 1
+ searchListBytes[3] = 2
+
+ const prefixLength = 43
+ const onLinkFlag = false
+ const slaacFlag = true
+ const preferredLifetimeSeconds = 84281096
+ const onLinkFlagBit = 7
+ const slaacFlagBit = 6
+ boolToByte := func(v bool) byte {
+ if v {
+ return 1
+ }
+ return 0
+ }
+ flags := boolToByte(onLinkFlag)<<onLinkFlagBit | boolToByte(slaacFlag)<<slaacFlagBit
+ expectedPrefixInformationBytes := [...]byte{
+ // Type, Length
+ 3, 4,
+
+ prefixLength, flags,
+
+ // Valid Lifetime
+ 1, 2, 3, 4,
+
+ // Preferred Lifetime
+ 5, 6, 7, 8,
+
+ // Reserved2
+ 0, 0, 0, 0,
+
+ // Address
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ 17, 18, 19, 20,
+ 21, 22, 23, 24,
+ }
+ binary.BigEndian.PutUint32(expectedPrefixInformationBytes[4:], validLifetimeSeconds)
+ binary.BigEndian.PutUint32(expectedPrefixInformationBytes[8:], preferredLifetimeSeconds)
+ if n := copy(expectedPrefixInformationBytes[16:], address); n != IPv6AddressSize {
+ t.Fatalf("got copy(...) = %d, want = %d", n, IPv6AddressSize)
+ }
+ // Update reserved fields to non zero values to make sure serializing sets
+ // them to zero.
+ prefixInformationBytes := expectedPrefixInformationBytes
+ prefixInformationBytes[3] |= (1 << slaacFlagBit) - 1
+ binary.BigEndian.PutUint32(prefixInformationBytes[12:], validLifetimeSeconds+1)
tests := []struct {
name string
buf []byte
+ opt NDPOption
expectedBuf []byte
- addr tcpip.LinkAddress
+ check func(*testing.T, NDPOption)
}{
{
- "Ethernet",
- make([]byte, 8),
- []byte{2, 1, 1, 2, 3, 4, 5, 6},
- "\x01\x02\x03\x04\x05\x06",
+ name: "Nonce",
+ buf: make([]byte, 8),
+ opt: NDPNonceOption([]byte{1, 2, 3, 4, 5, 6}),
+ expectedBuf: []byte{14, 1, 1, 2, 3, 4, 5, 6},
+ check: checkNonce([]byte{1, 2, 3, 4, 5, 6}),
+ },
+ {
+ name: "Nonce with padding",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1},
+ opt: NDPNonceOption([]byte{1, 2, 3, 4, 5}),
+ expectedBuf: []byte{14, 1, 1, 2, 3, 4, 5, 0},
+ check: checkNonce([]byte{1, 2, 3, 4, 5, 0}),
+ },
+
+ {
+ name: "TLL Ethernet",
+ buf: make([]byte, 8),
+ opt: NDPTargetLinkLayerAddressOption("\x01\x02\x03\x04\x05\x06"),
+ expectedBuf: []byte{2, 1, 1, 2, 3, 4, 5, 6},
+ check: checkTLL("\x01\x02\x03\x04\x05\x06"),
+ },
+ {
+ name: "TLL Padding",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ opt: NDPTargetLinkLayerAddressOption("\x01\x02\x03\x04\x05\x06\x07\x08"),
+ expectedBuf: []byte{2, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
+ check: checkTLL("\x01\x02\x03\x04\x05\x06"),
+ },
+ {
+ name: "TLL Empty",
+ buf: nil,
+ opt: NDPTargetLinkLayerAddressOption(""),
+ expectedBuf: nil,
+ },
+
+ {
+ name: "SLL Ethernet",
+ buf: make([]byte, 8),
+ opt: NDPSourceLinkLayerAddressOption("\x01\x02\x03\x04\x05\x06"),
+ expectedBuf: []byte{1, 1, 1, 2, 3, 4, 5, 6},
+ check: checkSLL("\x01\x02\x03\x04\x05\x06"),
+ },
+ {
+ name: "SLL Padding",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ opt: NDPSourceLinkLayerAddressOption("\x01\x02\x03\x04\x05\x06\x07\x08"),
+ expectedBuf: []byte{1, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
+ check: checkSLL("\x01\x02\x03\x04\x05\x06"),
+ },
+ {
+ name: "SLL Empty",
+ buf: nil,
+ opt: NDPSourceLinkLayerAddressOption(""),
+ expectedBuf: nil,
+ },
+
+ {
+ name: "RDNSS",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ // NDPRecursiveDNSServer holds the option after the header bytes.
+ opt: NDPRecursiveDNSServer(rdnssBytes[optionHeaderLen:]),
+ expectedBuf: expectedRDNSSBytes[:],
+ check: func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPRecursiveDNSServerOptionType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPRecursiveDNSServerOptionType)
+ }
+ rdnss, ok := opt.(NDPRecursiveDNSServer)
+ if !ok {
+ t.Fatalf("got opt = %T, want = NDPRecursiveDNSServer", opt)
+ }
+ if got, want := rdnss.Length(), len(expectedRDNSSBytes[optionHeaderLen:]); got != want {
+ t.Errorf("got Length() = %d, want = %d", got, want)
+ }
+ if got, want := rdnss.Lifetime(), validLifetimeSeconds*time.Second; got != want {
+ t.Errorf("got Lifetime() = %s, want = %s", got, want)
+ }
+ if addrs, err := rdnss.Addresses(); err != nil {
+ t.Errorf("Addresses(): %s", err)
+ } else if diff := cmp.Diff([]tcpip.Address{address}, addrs); diff != "" {
+ t.Errorf("mismatched addresses (-want +got):\n%s", diff)
+ }
+ },
},
+
{
- "Padding",
- []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
- []byte{2, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
- "\x01\x02\x03\x04\x05\x06\x07\x08",
+ name: "Search list",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ opt: NDPDNSSearchList(searchListBytes[optionHeaderLen:]),
+ expectedBuf: expectedSearchListBytes[:],
+ check: func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPDNSSearchListOptionType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPDNSSearchListOptionType)
+ }
+
+ dnssl, ok := opt.(NDPDNSSearchList)
+ if !ok {
+ t.Fatalf("got opt = %T, want = NDPDNSSearchList", opt)
+ }
+ if got, want := dnssl.Length(), len(expectedRDNSSBytes[optionHeaderLen:]); got != want {
+ t.Errorf("got Length() = %d, want = %d", got, want)
+ }
+ if got, want := dnssl.Lifetime(), validLifetimeSeconds*time.Second; got != want {
+ t.Errorf("got Lifetime() = %s, want = %s", got, want)
+ }
+
+ if domainNames, err := dnssl.DomainNames(); err != nil {
+ t.Errorf("DomainNames(): %s", err)
+ } else if diff := cmp.Diff([]string{domainName}, domainNames); diff != "" {
+ t.Errorf("domain names mismatch (-want +got):\n%s", diff)
+ }
+ },
},
+
{
- "Empty",
- nil,
- nil,
- "",
+ name: "Prefix Information",
+ buf: []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ // NDPPrefixInformation holds the option after the header bytes.
+ opt: NDPPrefixInformation(prefixInformationBytes[optionHeaderLen:]),
+ expectedBuf: expectedPrefixInformationBytes[:],
+ check: func(t *testing.T, opt NDPOption) {
+ if got := opt.Type(); got != NDPPrefixInformationType {
+ t.Errorf("got Type() = %d, want = %d", got, NDPPrefixInformationType)
+ }
+
+ pi, ok := opt.(NDPPrefixInformation)
+ if !ok {
+ t.Fatalf("got opt = %T, want = NDPPrefixInformation", opt)
+ }
+
+ if got, want := pi.Length(), len(expectedPrefixInformationBytes[optionHeaderLen:]); got != want {
+ t.Errorf("got Length() = %d, want = %d", got, want)
+ }
+ if got := pi.PrefixLength(); got != prefixLength {
+ t.Errorf("got PrefixLength() = %d, want = %d", got, prefixLength)
+ }
+ if got := pi.OnLinkFlag(); got != onLinkFlag {
+ t.Errorf("got OnLinkFlag() = %t, want = %t", got, onLinkFlag)
+ }
+ if got := pi.AutonomousAddressConfigurationFlag(); got != slaacFlag {
+ t.Errorf("got AutonomousAddressConfigurationFlag() = %t, want = %t", got, slaacFlag)
+ }
+ if got, want := pi.ValidLifetime(), validLifetimeSeconds*time.Second; got != want {
+ t.Errorf("got ValidLifetime() = %s, want = %s", got, want)
+ }
+ if got, want := pi.PreferredLifetime(), preferredLifetimeSeconds*time.Second; got != want {
+ t.Errorf("got PreferredLifetime() = %s, want = %s", got, want)
+ }
+ if got := pi.Prefix(); got != address {
+ t.Errorf("got Prefix() = %s, want = %s", got, address)
+ }
+ },
},
}
@@ -344,230 +538,47 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
t.Run(test.name, func(t *testing.T) {
opts := NDPOptions(test.buf)
serializer := NDPOptionsSerializer{
- NDPTargetLinkLayerAddressOption(test.addr),
+ test.opt,
}
if got, want := int(serializer.Length()), len(test.expectedBuf); got != want {
- t.Fatalf("got Length = %d, want = %d", got, want)
+ t.Fatalf("got Length() = %d, want = %d", got, want)
}
opts.Serialize(serializer)
- if !bytes.Equal(test.buf, test.expectedBuf) {
- t.Fatalf("got b = %d, want = %d", test.buf, test.expectedBuf)
+ if diff := cmp.Diff(test.expectedBuf, test.buf); diff != "" {
+ t.Fatalf("serialized buffer mismatch (-want +got):\n%s", diff)
}
it, err := opts.Iter(true)
if err != nil {
- t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
+ t.Fatalf("got Iter(true) = (_, %s), want = (_, nil)", err)
}
if len(test.expectedBuf) > 0 {
next, done, err := it.Next()
if err != nil {
- t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
+ t.Fatalf("got Next() = (_, _, %s), want = (_, _, nil)", err)
}
if done {
- t.Fatal("got Next = (_, true, _), want = (_, false, _)")
- }
- if got := next.Type(); got != NDPTargetLinkLayerAddressOptionType {
- t.Fatalf("got Type = %d, want = %d", got, NDPTargetLinkLayerAddressOptionType)
- }
- tll := next.(NDPTargetLinkLayerAddressOption)
- if got, want := []byte(tll), test.expectedBuf[2:]; !bytes.Equal(got, want) {
- t.Fatalf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
- }
-
- if got, want := tll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want {
- t.Errorf("got tll.EthernetAddress = %s, want = %s", got, want)
+ t.Fatal("got Next() = (_, true, _), want = (_, false, _)")
}
+ test.check(t, next)
}
// Iterator should not return anything else.
next, done, err := it.Next()
if err != nil {
- t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
+ t.Errorf("got Next() = (_, _, %s), want = (_, _, nil)", err)
}
if !done {
- t.Error("got Next = (_, false, _), want = (_, true, _)")
+ t.Error("got Next() = (_, false, _), want = (_, true, _)")
}
if next != nil {
- t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
+ t.Errorf("got Next() = (%x, _, _), want = (nil, _, _)", next)
}
})
}
}
-// TestNDPPrefixInformationOption tests the field getters and serialization of a
-// NDPPrefixInformation.
-func TestNDPPrefixInformationOption(t *testing.T) {
- b := []byte{
- 43, 127,
- 1, 2, 3, 4,
- 5, 6, 7, 8,
- 5, 5, 5, 5,
- 9, 10, 11, 12,
- 13, 14, 15, 16,
- 17, 18, 19, 20,
- 21, 22, 23, 24,
- }
-
- targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
- opts := NDPOptions(targetBuf)
- serializer := NDPOptionsSerializer{
- NDPPrefixInformation(b),
- }
- opts.Serialize(serializer)
- expectedBuf := []byte{
- 3, 4, 43, 64,
- 1, 2, 3, 4,
- 5, 6, 7, 8,
- 0, 0, 0, 0,
- 9, 10, 11, 12,
- 13, 14, 15, 16,
- 17, 18, 19, 20,
- 21, 22, 23, 24,
- }
- if !bytes.Equal(targetBuf, expectedBuf) {
- t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expectedBuf)
- }
-
- it, err := opts.Iter(true)
- if err != nil {
- t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
- }
-
- next, done, err := it.Next()
- if err != nil {
- t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if done {
- t.Fatal("got Next = (_, true, _), want = (_, false, _)")
- }
- if got := next.Type(); got != NDPPrefixInformationType {
- t.Errorf("got Type = %d, want = %d", got, NDPPrefixInformationType)
- }
-
- pi := next.(NDPPrefixInformation)
-
- if got := pi.Type(); got != 3 {
- t.Errorf("got Type = %d, want = 3", got)
- }
-
- if got := pi.Length(); got != 30 {
- t.Errorf("got Length = %d, want = 30", got)
- }
-
- if got := pi.PrefixLength(); got != 43 {
- t.Errorf("got PrefixLength = %d, want = 43", got)
- }
-
- if pi.OnLinkFlag() {
- t.Error("got OnLinkFlag = true, want = false")
- }
-
- if !pi.AutonomousAddressConfigurationFlag() {
- t.Error("got AutonomousAddressConfigurationFlag = false, want = true")
- }
-
- if got, want := pi.ValidLifetime(), 16909060*time.Second; got != want {
- t.Errorf("got ValidLifetime = %d, want = %d", got, want)
- }
-
- if got, want := pi.PreferredLifetime(), 84281096*time.Second; got != want {
- t.Errorf("got PreferredLifetime = %d, want = %d", got, want)
- }
-
- if got, want := pi.Prefix(), tcpip.Address("\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18"); got != want {
- t.Errorf("got Prefix = %s, want = %s", got, want)
- }
-
- // Iterator should not return anything else.
- next, done, err = it.Next()
- if err != nil {
- t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if !done {
- t.Error("got Next = (_, false, _), want = (_, true, _)")
- }
- if next != nil {
- t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
- }
-}
-
-func TestNDPRecursiveDNSServerOptionSerialize(t *testing.T) {
- b := []byte{
- 9, 8,
- 1, 2, 4, 8,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
- }
- targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
- expected := []byte{
- 25, 3, 0, 0,
- 1, 2, 4, 8,
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
- }
- opts := NDPOptions(targetBuf)
- serializer := NDPOptionsSerializer{
- NDPRecursiveDNSServer(b),
- }
- if got, want := opts.Serialize(serializer), len(expected); got != want {
- t.Errorf("got Serialize = %d, want = %d", got, want)
- }
- if !bytes.Equal(targetBuf, expected) {
- t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expected)
- }
-
- it, err := opts.Iter(true)
- if err != nil {
- t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
- }
-
- next, done, err := it.Next()
- if err != nil {
- t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if done {
- t.Fatal("got Next = (_, true, _), want = (_, false, _)")
- }
- if got := next.Type(); got != NDPRecursiveDNSServerOptionType {
- t.Errorf("got Type = %d, want = %d", got, NDPRecursiveDNSServerOptionType)
- }
-
- opt, ok := next.(NDPRecursiveDNSServer)
- if !ok {
- t.Fatalf("next (type = %T) cannot be casted to an NDPRecursiveDNSServer", next)
- }
- if got := opt.Type(); got != 25 {
- t.Errorf("got Type = %d, want = 31", got)
- }
- if got := opt.Length(); got != 22 {
- t.Errorf("got Length = %d, want = 22", got)
- }
- if got, want := opt.Lifetime(), 16909320*time.Second; got != want {
- t.Errorf("got Lifetime = %s, want = %s", got, want)
- }
- want := []tcpip.Address{
- "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
- }
- addrs, err := opt.Addresses()
- if err != nil {
- t.Errorf("opt.Addresses() = %s", err)
- }
- if diff := cmp.Diff(addrs, want); diff != "" {
- t.Errorf("mismatched addresses (-want +got):\n%s", diff)
- }
-
- // Iterator should not return anything else.
- next, done, err = it.Next()
- if err != nil {
- t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if !done {
- t.Error("got Next = (_, false, _), want = (_, true, _)")
- }
- if next != nil {
- t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
- }
-}
-
func TestNDPRecursiveDNSServerOption(t *testing.T) {
tests := []struct {
name string
@@ -1060,86 +1071,6 @@ func TestNDPSearchListOptionDomainNameLabelInvalidSymbols(t *testing.T) {
}
}
-func TestNDPDNSSearchListOptionSerialize(t *testing.T) {
- b := []byte{
- 9, 8,
- 1, 0, 0, 0,
- 3, 'a', 'b', 'c',
- 4, 'a', 'b', 'c', 'd',
- 1, 'e',
- 0,
- }
- targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}
- expected := []byte{
- 31, 3, 0, 0,
- 1, 0, 0, 0,
- 3, 'a', 'b', 'c',
- 4, 'a', 'b', 'c', 'd',
- 1, 'e',
- 0,
- 0, 0, 0, 0,
- }
- opts := NDPOptions(targetBuf)
- serializer := NDPOptionsSerializer{
- NDPDNSSearchList(b),
- }
- if got, want := opts.Serialize(serializer), len(expected); got != want {
- t.Errorf("got Serialize = %d, want = %d", got, want)
- }
- if !bytes.Equal(targetBuf, expected) {
- t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expected)
- }
-
- it, err := opts.Iter(true)
- if err != nil {
- t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
- }
-
- next, done, err := it.Next()
- if err != nil {
- t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if done {
- t.Fatal("got Next = (_, true, _), want = (_, false, _)")
- }
- if got := next.Type(); got != NDPDNSSearchListOptionType {
- t.Errorf("got Type = %d, want = %d", got, NDPDNSSearchListOptionType)
- }
-
- opt, ok := next.(NDPDNSSearchList)
- if !ok {
- t.Fatalf("next (type = %T) cannot be casted to an NDPDNSSearchList", next)
- }
- if got := opt.Type(); got != 31 {
- t.Errorf("got Type = %d, want = 31", got)
- }
- if got := opt.Length(); got != 22 {
- t.Errorf("got Length = %d, want = 22", got)
- }
- if got, want := opt.Lifetime(), 16777216*time.Second; got != want {
- t.Errorf("got Lifetime = %s, want = %s", got, want)
- }
- domainNames, err := opt.DomainNames()
- if err != nil {
- t.Errorf("opt.DomainNames() = %s", err)
- }
- if diff := cmp.Diff(domainNames, []string{"abc.abcd.e"}); diff != "" {
- t.Errorf("domain names mismatch (-want +got):\n%s", diff)
- }
-
- // Iterator should not return anything else.
- next, done, err = it.Next()
- if err != nil {
- t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
- }
- if !done {
- t.Error("got Next = (_, false, _), want = (_, true, _)")
- }
- if next != nil {
- t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
- }
-}
-
// TestNDPOptionsIterCheck tests that Iter will return false if the NDPOptions
// the iterator was returned for is malformed.
func TestNDPOptionsIterCheck(t *testing.T) {
diff --git a/pkg/tcpip/header/ndpoptionidentifier_string.go b/pkg/tcpip/header/ndpoptionidentifier_string.go
index 6fe9a336b..83f94a730 100644
--- a/pkg/tcpip/header/ndpoptionidentifier_string.go
+++ b/pkg/tcpip/header/ndpoptionidentifier_string.go
@@ -12,7 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-// Code generated by "stringer -type NDPOptionIdentifier ."; DO NOT EDIT.
+// Code generated by "stringer -type NDPOptionIdentifier"; DO NOT EDIT.
package header
@@ -25,12 +25,16 @@ func _() {
_ = x[NDPSourceLinkLayerAddressOptionType-1]
_ = x[NDPTargetLinkLayerAddressOptionType-2]
_ = x[NDPPrefixInformationType-3]
+ _ = x[NDPNonceOptionType-14]
_ = x[NDPRecursiveDNSServerOptionType-25]
+ _ = x[NDPDNSSearchListOptionType-31]
}
const (
_NDPOptionIdentifier_name_0 = "NDPSourceLinkLayerAddressOptionTypeNDPTargetLinkLayerAddressOptionTypeNDPPrefixInformationType"
- _NDPOptionIdentifier_name_1 = "NDPRecursiveDNSServerOptionType"
+ _NDPOptionIdentifier_name_1 = "NDPNonceOptionType"
+ _NDPOptionIdentifier_name_2 = "NDPRecursiveDNSServerOptionType"
+ _NDPOptionIdentifier_name_3 = "NDPDNSSearchListOptionType"
)
var (
@@ -42,8 +46,12 @@ func (i NDPOptionIdentifier) String() string {
case 1 <= i && i <= 3:
i -= 1
return _NDPOptionIdentifier_name_0[_NDPOptionIdentifier_index_0[i]:_NDPOptionIdentifier_index_0[i+1]]
- case i == 25:
+ case i == 14:
return _NDPOptionIdentifier_name_1
+ case i == 25:
+ return _NDPOptionIdentifier_name_2
+ case i == 31:
+ return _NDPOptionIdentifier_name_3
default:
return "NDPOptionIdentifier(" + strconv.FormatInt(int64(i), 10) + ")"
}
diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go
index 43a4b7cac..7ae38d684 100644
--- a/pkg/tcpip/network/arp/arp.go
+++ b/pkg/tcpip/network/arp/arp.go
@@ -38,6 +38,7 @@ const (
var _ stack.DuplicateAddressDetector = (*endpoint)(nil)
var _ stack.LinkAddressResolver = (*endpoint)(nil)
+var _ ip.DADProtocol = (*endpoint)(nil)
// ARP endpoints need to implement stack.NetworkEndpoint because the stack
// considers the layer above the link-layer a network layer; the only
@@ -82,7 +83,8 @@ func (*endpoint) DuplicateAddressProtocol() tcpip.NetworkProtocolNumber {
return header.IPv4ProtocolNumber
}
-func (e *endpoint) SendDADMessage(addr tcpip.Address) tcpip.Error {
+// SendDADMessage implements ip.DADProtocol.
+func (e *endpoint) SendDADMessage(addr tcpip.Address, _ []byte) tcpip.Error {
return e.sendARPRequest(header.IPv4Any, addr, header.EthernetBroadcastAddress)
}
@@ -284,9 +286,12 @@ func (p *protocol) NewEndpoint(nic stack.NetworkInterface, dispatcher stack.Tran
e.mu.Lock()
e.mu.dad.Init(&e.mu, p.options.DADConfigs, ip.DADOptions{
- Clock: p.stack.Clock(),
- Protocol: e,
- NICID: nic.ID(),
+ Clock: p.stack.Clock(),
+ SecureRNG: p.stack.SecureRNG(),
+ // ARP does not support sending nonce values.
+ NonceSize: 0,
+ Protocol: e,
+ NICID: nic.ID(),
})
e.mu.Unlock()
diff --git a/pkg/tcpip/network/internal/ip/duplicate_address_detection.go b/pkg/tcpip/network/internal/ip/duplicate_address_detection.go
index 0053646ee..eed49f5d2 100644
--- a/pkg/tcpip/network/internal/ip/duplicate_address_detection.go
+++ b/pkg/tcpip/network/internal/ip/duplicate_address_detection.go
@@ -16,14 +16,27 @@
package ip
import (
+ "bytes"
"fmt"
+ "io"
"gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/stack"
)
+type extendRequest int
+
+const (
+ notRequested extendRequest = iota
+ requested
+ extended
+)
+
type dadState struct {
+ nonce []byte
+ extendRequest extendRequest
+
done *bool
timer tcpip.Timer
@@ -33,14 +46,17 @@ type dadState struct {
// DADProtocol is a protocol whose core state machine can be represented by DAD.
type DADProtocol interface {
// SendDADMessage attempts to send a DAD probe message.
- SendDADMessage(tcpip.Address) tcpip.Error
+ SendDADMessage(tcpip.Address, []byte) tcpip.Error
}
// DADOptions holds options for DAD.
type DADOptions struct {
- Clock tcpip.Clock
- Protocol DADProtocol
- NICID tcpip.NICID
+ Clock tcpip.Clock
+ SecureRNG io.Reader
+ NonceSize uint8
+ ExtendDADTransmits uint8
+ Protocol DADProtocol
+ NICID tcpip.NICID
}
// DAD performs duplicate address detection for addresses.
@@ -63,6 +79,10 @@ func (d *DAD) Init(protocolMU sync.Locker, configs stack.DADConfigurations, opts
panic("attempted to initialize DAD state twice")
}
+ if opts.NonceSize != 0 && opts.ExtendDADTransmits == 0 {
+ panic(fmt.Sprintf("given a non-zero value for NonceSize (%d) but zero for ExtendDADTransmits", opts.NonceSize))
+ }
+
*d = DAD{
opts: opts,
configs: configs,
@@ -96,10 +116,55 @@ func (d *DAD) CheckDuplicateAddressLocked(addr tcpip.Address, h stack.DADComplet
s = dadState{
done: &done,
timer: d.opts.Clock.AfterFunc(0, func() {
- var err tcpip.Error
dadDone := remaining == 0
+
+ nonce, earlyReturn := func() ([]byte, bool) {
+ d.protocolMU.Lock()
+ defer d.protocolMU.Unlock()
+
+ if done {
+ return nil, true
+ }
+
+ s, ok := d.addresses[addr]
+ if !ok {
+ panic(fmt.Sprintf("dad: timer fired but missing state for %s on NIC(%d)", addr, d.opts.NICID))
+ }
+
+ // As per RFC 7527 section 4
+ //
+ // If any probe is looped back within RetransTimer milliseconds
+ // after having sent DupAddrDetectTransmits NS(DAD) messages, the
+ // interface continues with another MAX_MULTICAST_SOLICIT number of
+ // NS(DAD) messages transmitted RetransTimer milliseconds apart.
+ if dadDone && s.extendRequest == requested {
+ dadDone = false
+ remaining = d.opts.ExtendDADTransmits
+ s.extendRequest = extended
+ }
+
+ if !dadDone && d.opts.NonceSize != 0 {
+ if s.nonce == nil {
+ s.nonce = make([]byte, d.opts.NonceSize)
+ }
+
+ if n, err := io.ReadFull(d.opts.SecureRNG, s.nonce); err != nil {
+ panic(fmt.Sprintf("SecureRNG.Read(...): %s", err))
+ } else if n != len(s.nonce) {
+ panic(fmt.Sprintf("expected to read %d bytes from secure RNG, only read %d bytes", len(s.nonce), n))
+ }
+ }
+
+ d.addresses[addr] = s
+ return s.nonce, false
+ }()
+ if earlyReturn {
+ return
+ }
+
+ var err tcpip.Error
if !dadDone {
- err = d.opts.Protocol.SendDADMessage(addr)
+ err = d.opts.Protocol.SendDADMessage(addr, nonce)
}
d.protocolMU.Lock()
@@ -142,6 +207,68 @@ func (d *DAD) CheckDuplicateAddressLocked(addr tcpip.Address, h stack.DADComplet
return ret
}
+// ExtendIfNonceEqualLockedDisposition enumerates the possible results from
+// ExtendIfNonceEqualLocked.
+type ExtendIfNonceEqualLockedDisposition int
+
+const (
+ // Extended indicates that the DAD process was extended.
+ Extended ExtendIfNonceEqualLockedDisposition = iota
+
+ // AlreadyExtended indicates that the DAD process was already extended.
+ AlreadyExtended
+
+ // NoDADStateFound indicates that DAD state was not found for the address.
+ NoDADStateFound
+
+ // NonceDisabled indicates that nonce values are not sent with DAD messages.
+ NonceDisabled
+
+ // NonceNotEqual indicates that the nonce value passed and the nonce in the
+ // last send DAD message are not equal.
+ NonceNotEqual
+)
+
+// ExtendIfNonceEqualLocked extends the DAD process if the provided nonce is the
+// same as the nonce sent in the last DAD message.
+//
+// Precondition: d.protocolMU must be locked.
+func (d *DAD) ExtendIfNonceEqualLocked(addr tcpip.Address, nonce []byte) ExtendIfNonceEqualLockedDisposition {
+ s, ok := d.addresses[addr]
+ if !ok {
+ return NoDADStateFound
+ }
+
+ if d.opts.NonceSize == 0 {
+ return NonceDisabled
+ }
+
+ if s.extendRequest != notRequested {
+ return AlreadyExtended
+ }
+
+ // As per RFC 7527 section 4
+ //
+ // If any probe is looped back within RetransTimer milliseconds after having
+ // sent DupAddrDetectTransmits NS(DAD) messages, the interface continues
+ // with another MAX_MULTICAST_SOLICIT number of NS(DAD) messages transmitted
+ // RetransTimer milliseconds apart.
+ //
+ // If a DAD message has already been sent and the nonce value we observed is
+ // the same as the nonce value we last sent, then we assume our probe was
+ // looped back and request an extension to the DAD process.
+ //
+ // Note, the first DAD message is sent asynchronously so we need to make sure
+ // that we sent a DAD message by checking if we have a nonce value set.
+ if s.nonce != nil && bytes.Equal(s.nonce, nonce) {
+ s.extendRequest = requested
+ d.addresses[addr] = s
+ return Extended
+ }
+
+ return NonceNotEqual
+}
+
// StopLocked stops a currently running DAD process.
//
// Precondition: d.protocolMU must be locked.
diff --git a/pkg/tcpip/network/internal/ip/duplicate_address_detection_test.go b/pkg/tcpip/network/internal/ip/duplicate_address_detection_test.go
index e00aa4678..a22b712c6 100644
--- a/pkg/tcpip/network/internal/ip/duplicate_address_detection_test.go
+++ b/pkg/tcpip/network/internal/ip/duplicate_address_detection_test.go
@@ -15,6 +15,7 @@
package ip_test
import (
+ "bytes"
"testing"
"time"
@@ -32,8 +33,8 @@ type mockDADProtocol struct {
mu struct {
sync.Mutex
- dad ip.DAD
- sendCount map[tcpip.Address]int
+ dad ip.DAD
+ sentNonces map[tcpip.Address][][]byte
}
}
@@ -48,26 +49,30 @@ func (m *mockDADProtocol) init(t *testing.T, c stack.DADConfigurations, opts ip.
}
func (m *mockDADProtocol) initLocked() {
- m.mu.sendCount = make(map[tcpip.Address]int)
+ m.mu.sentNonces = make(map[tcpip.Address][][]byte)
}
-func (m *mockDADProtocol) SendDADMessage(addr tcpip.Address) tcpip.Error {
+func (m *mockDADProtocol) SendDADMessage(addr tcpip.Address, nonce []byte) tcpip.Error {
m.mu.Lock()
defer m.mu.Unlock()
- m.mu.sendCount[addr]++
+ m.mu.sentNonces[addr] = append(m.mu.sentNonces[addr], nonce)
return nil
}
func (m *mockDADProtocol) check(addrs []tcpip.Address) string {
- m.mu.Lock()
- defer m.mu.Unlock()
-
- sendCount := make(map[tcpip.Address]int)
+ sentNonces := make(map[tcpip.Address][][]byte)
for _, a := range addrs {
- sendCount[a]++
+ sentNonces[a] = append(sentNonces[a], nil)
}
- diff := cmp.Diff(sendCount, m.mu.sendCount)
+ return m.checkWithNonce(sentNonces)
+}
+
+func (m *mockDADProtocol) checkWithNonce(expectedSentNonces map[tcpip.Address][][]byte) string {
+ m.mu.Lock()
+ defer m.mu.Unlock()
+
+ diff := cmp.Diff(expectedSentNonces, m.mu.sentNonces)
m.initLocked()
return diff
}
@@ -84,6 +89,12 @@ func (m *mockDADProtocol) stop(addr tcpip.Address, reason stack.DADResult) {
m.mu.dad.StopLocked(addr, reason)
}
+func (m *mockDADProtocol) extendIfNonceEqual(addr tcpip.Address, nonce []byte) ip.ExtendIfNonceEqualLockedDisposition {
+ m.mu.Lock()
+ defer m.mu.Unlock()
+ return m.mu.dad.ExtendIfNonceEqualLocked(addr, nonce)
+}
+
func (m *mockDADProtocol) setConfigs(c stack.DADConfigurations) {
m.mu.Lock()
defer m.mu.Unlock()
@@ -277,3 +288,94 @@ func TestDADStop(t *testing.T) {
default:
}
}
+
+func TestNonce(t *testing.T) {
+ const (
+ nonceSize = 2
+
+ extendRequestAttempts = 2
+
+ dupAddrDetectTransmits = 2
+ extendTransmits = 5
+ )
+
+ var secureRNGBytes [nonceSize * (dupAddrDetectTransmits + extendTransmits)]byte
+ for i := range secureRNGBytes {
+ secureRNGBytes[i] = byte(i)
+ }
+
+ tests := []struct {
+ name string
+ mockedReceivedNonce []byte
+ expectedResults [extendRequestAttempts]ip.ExtendIfNonceEqualLockedDisposition
+ expectedTransmits int
+ }{
+ {
+ name: "not matching",
+ mockedReceivedNonce: []byte{0, 0},
+ expectedResults: [extendRequestAttempts]ip.ExtendIfNonceEqualLockedDisposition{ip.NonceNotEqual, ip.NonceNotEqual},
+ expectedTransmits: dupAddrDetectTransmits,
+ },
+ {
+ name: "matching nonce",
+ mockedReceivedNonce: secureRNGBytes[:nonceSize],
+ expectedResults: [extendRequestAttempts]ip.ExtendIfNonceEqualLockedDisposition{ip.Extended, ip.AlreadyExtended},
+ expectedTransmits: dupAddrDetectTransmits + extendTransmits,
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ var dad mockDADProtocol
+ clock := faketime.NewManualClock()
+ dadConfigs := stack.DADConfigurations{
+ DupAddrDetectTransmits: dupAddrDetectTransmits,
+ RetransmitTimer: time.Second,
+ }
+
+ var secureRNG bytes.Reader
+ secureRNG.Reset(secureRNGBytes[:])
+ dad.init(t, dadConfigs, ip.DADOptions{
+ Clock: clock,
+ SecureRNG: &secureRNG,
+ NonceSize: nonceSize,
+ ExtendDADTransmits: extendTransmits,
+ })
+
+ ch := make(chan dadResult, 1)
+ if res := dad.checkDuplicateAddress(addr1, handler(ch, addr1)); res != stack.DADStarting {
+ t.Errorf("got dad.checkDuplicateAddress(%s, _) = %d, want = %d", addr1, res, stack.DADStarting)
+ }
+
+ clock.Advance(0)
+ for i, want := range test.expectedResults {
+ if got := dad.extendIfNonceEqual(addr1, test.mockedReceivedNonce); got != want {
+ t.Errorf("(i=%d) got dad.extendIfNonceEqual(%s, _) = %d, want = %d", i, addr1, got, want)
+ }
+ }
+
+ for i := 0; i < test.expectedTransmits; i++ {
+ if diff := dad.checkWithNonce(map[tcpip.Address][][]byte{
+ addr1: {
+ secureRNGBytes[nonceSize*i:][:nonceSize],
+ },
+ }); diff != "" {
+ t.Errorf("(i=%d) dad check mismatch (-want +got):\n%s", i, diff)
+ }
+
+ clock.Advance(dadConfigs.RetransmitTimer)
+ }
+
+ if diff := cmp.Diff(dadResult{Addr: addr1, R: &stack.DADSucceeded{}}, <-ch); diff != "" {
+ t.Errorf("dad result mismatch (-want +got):\n%s", diff)
+ }
+
+ // Should not have anymore updates.
+ select {
+ case r := <-ch:
+ t.Fatalf("unexpectedly got an extra DAD result; r = %#v", r)
+ default:
+ }
+ })
+ }
+}
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 8059e0690..2afa856dc 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -369,6 +369,18 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
return
}
+ var it header.NDPOptionIterator
+ {
+ var err error
+ it, err = ns.Options().Iter(false /* check */)
+ if err != nil {
+ // Options are not valid as per the wire format, silently drop the
+ // packet.
+ received.invalid.Increment()
+ return
+ }
+ }
+
if e.hasTentativeAddr(targetAddr) {
// If the target address is tentative and the source of the packet is a
// unicast (specified) address, then the source of the packet is
@@ -382,6 +394,22 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
// stack know so it can handle such a scenario and do nothing further with
// the NS.
if srcAddr == header.IPv6Any {
+ var nonce []byte
+ for {
+ opt, done, err := it.Next()
+ if err != nil {
+ received.invalid.Increment()
+ return
+ }
+ if done {
+ break
+ }
+ if n, ok := opt.(header.NDPNonceOption); ok {
+ nonce = n.Nonce()
+ break
+ }
+ }
+
// Since this is a DAD message we know the sender does not actually hold
// the target address so there is no "holder".
var holderLinkAddress tcpip.LinkAddress
@@ -397,7 +425,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
//
// TODO(gvisor.dev/issue/4046): Handle the scenario when a duplicate
// address is detected for an assigned address.
- switch err := e.dupTentativeAddrDetected(targetAddr, holderLinkAddress); err.(type) {
+ switch err := e.dupTentativeAddrDetected(targetAddr, holderLinkAddress, nonce); err.(type) {
case nil, *tcpip.ErrBadAddress, *tcpip.ErrInvalidEndpointState:
default:
panic(fmt.Sprintf("unexpected error handling duplicate tentative address: %s", err))
@@ -418,21 +446,10 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
return
}
- var sourceLinkAddr tcpip.LinkAddress
- {
- it, err := ns.Options().Iter(false /* check */)
- if err != nil {
- // Options are not valid as per the wire format, silently drop the
- // packet.
- received.invalid.Increment()
- return
- }
-
- sourceLinkAddr, ok = getSourceLinkAddr(it)
- if !ok {
- received.invalid.Increment()
- return
- }
+ sourceLinkAddr, ok := getSourceLinkAddr(it)
+ if !ok {
+ received.invalid.Increment()
+ return
}
// As per RFC 4861 section 4.3, the Source Link-Layer Address Option MUST
@@ -586,6 +603,10 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
e.dad.mu.Unlock()
if e.hasTentativeAddr(targetAddr) {
+ // We only send a nonce value in DAD messages to check for loopedback
+ // messages so we use the empty nonce value here.
+ var nonce []byte
+
// We just got an NA from a node that owns an address we are performing
// DAD on, implying the address is not unique. In this case we let the
// stack know so it can handle such a scenario and do nothing furthur with
@@ -602,7 +623,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
//
// TODO(gvisor.dev/issue/4046): Handle the scenario when a duplicate
// address is detected for an assigned address.
- switch err := e.dupTentativeAddrDetected(targetAddr, targetLinkAddr); err.(type) {
+ switch err := e.dupTentativeAddrDetected(targetAddr, targetLinkAddr, nonce); err.(type) {
case nil, *tcpip.ErrBadAddress, *tcpip.ErrInvalidEndpointState:
return
default:
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 46b6cc41a..350493958 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -348,7 +348,7 @@ func (e *endpoint) hasTentativeAddr(addr tcpip.Address) bool {
// dupTentativeAddrDetected removes the tentative address if it exists. If the
// address was generated via SLAAC, an attempt is made to generate a new
// address.
-func (e *endpoint) dupTentativeAddrDetected(addr tcpip.Address, holderLinkAddr tcpip.LinkAddress) tcpip.Error {
+func (e *endpoint) dupTentativeAddrDetected(addr tcpip.Address, holderLinkAddr tcpip.LinkAddress, nonce []byte) tcpip.Error {
e.mu.Lock()
defer e.mu.Unlock()
@@ -361,27 +361,48 @@ func (e *endpoint) dupTentativeAddrDetected(addr tcpip.Address, holderLinkAddr t
return &tcpip.ErrInvalidEndpointState{}
}
- // If the address is a SLAAC address, do not invalidate its SLAAC prefix as an
- // attempt will be made to generate a new address for it.
- if err := e.removePermanentEndpointLocked(addressEndpoint, false /* allowSLAACInvalidation */, &stack.DADDupAddrDetected{HolderLinkAddress: holderLinkAddr}); err != nil {
- return err
- }
+ switch result := e.mu.ndp.dad.ExtendIfNonceEqualLocked(addr, nonce); result {
+ case ip.Extended:
+ // The nonce we got back was the same we sent so we know the message
+ // indicating a duplicate address was likely ours so do not consider
+ // the address duplicate here.
+ return nil
+ case ip.AlreadyExtended:
+ // See Extended.
+ //
+ // Our DAD message was looped back already.
+ return nil
+ case ip.NoDADStateFound:
+ panic(fmt.Sprintf("expected DAD state for tentative address %s", addr))
+ case ip.NonceDisabled:
+ // If nonce is disabled then we have no way to know if the packet was
+ // looped-back so we have to assume it indicates a duplicate address.
+ fallthrough
+ case ip.NonceNotEqual:
+ // If the address is a SLAAC address, do not invalidate its SLAAC prefix as an
+ // attempt will be made to generate a new address for it.
+ if err := e.removePermanentEndpointLocked(addressEndpoint, false /* allowSLAACInvalidation */, &stack.DADDupAddrDetected{HolderLinkAddress: holderLinkAddr}); err != nil {
+ return err
+ }
- prefix := addressEndpoint.Subnet()
+ prefix := addressEndpoint.Subnet()
- switch t := addressEndpoint.ConfigType(); t {
- case stack.AddressConfigStatic:
- case stack.AddressConfigSlaac:
- e.mu.ndp.regenerateSLAACAddr(prefix)
- case stack.AddressConfigSlaacTemp:
- // Do not reset the generation attempts counter for the prefix as the
- // temporary address is being regenerated in response to a DAD conflict.
- e.mu.ndp.regenerateTempSLAACAddr(prefix, false /* resetGenAttempts */)
+ switch t := addressEndpoint.ConfigType(); t {
+ case stack.AddressConfigStatic:
+ case stack.AddressConfigSlaac:
+ e.mu.ndp.regenerateSLAACAddr(prefix)
+ case stack.AddressConfigSlaacTemp:
+ // Do not reset the generation attempts counter for the prefix as the
+ // temporary address is being regenerated in response to a DAD conflict.
+ e.mu.ndp.regenerateTempSLAACAddr(prefix, false /* resetGenAttempts */)
+ default:
+ panic(fmt.Sprintf("unrecognized address config type = %d", t))
+ }
+
+ return nil
default:
- panic(fmt.Sprintf("unrecognized address config type = %d", t))
+ panic(fmt.Sprintf("unhandled result = %d", result))
}
-
- return nil
}
// transitionForwarding transitions the endpoint's forwarding status to
@@ -1797,16 +1818,36 @@ func (p *protocol) NewEndpoint(nic stack.NetworkInterface, dispatcher stack.Tran
dispatcher: dispatcher,
protocol: p,
}
+
+ // NDP options must be 8 octet aligned and the first 2 bytes are used for
+ // the type and length fields leaving 6 octets as the minimum size for a
+ // nonce option without padding.
+ const nonceSize = 6
+
+ // As per RFC 7527 section 4.1,
+ //
+ // If any probe is looped back within RetransTimer milliseconds after
+ // having sent DupAddrDetectTransmits NS(DAD) messages, the interface
+ // continues with another MAX_MULTICAST_SOLICIT number of NS(DAD)
+ // messages transmitted RetransTimer milliseconds apart.
+ //
+ // Value taken from RFC 4861 section 10.
+ const maxMulticastSolicit = 3
+ dadOptions := ip.DADOptions{
+ Clock: p.stack.Clock(),
+ SecureRNG: p.stack.SecureRNG(),
+ NonceSize: nonceSize,
+ ExtendDADTransmits: maxMulticastSolicit,
+ Protocol: &e.mu.ndp,
+ NICID: nic.ID(),
+ }
+
e.mu.Lock()
e.mu.addressableEndpointState.Init(e)
- e.mu.ndp.init(e)
+ e.mu.ndp.init(e, dadOptions)
e.mu.mld.init(e)
e.dad.mu.Lock()
- e.dad.mu.dad.Init(&e.dad.mu, p.options.DADConfigs, ip.DADOptions{
- Clock: p.stack.Clock(),
- Protocol: &e.mu.ndp,
- NICID: nic.ID(),
- })
+ e.dad.mu.dad.Init(&e.dad.mu, p.options.DADConfigs, dadOptions)
e.dad.mu.Unlock()
e.mu.Unlock()
diff --git a/pkg/tcpip/network/ipv6/mld_test.go b/pkg/tcpip/network/ipv6/mld_test.go
index 9a425e50a..85a8f9944 100644
--- a/pkg/tcpip/network/ipv6/mld_test.go
+++ b/pkg/tcpip/network/ipv6/mld_test.go
@@ -15,6 +15,7 @@
package ipv6_test
import (
+ "bytes"
"testing"
"time"
@@ -119,11 +120,26 @@ func TestSendQueuedMLDReports(t *testing.T) {
},
}
+ nonce := [...]byte{
+ 1, 2, 3, 4, 5, 6,
+ }
+
+ const maxNSMessages = 2
+ secureRNGBytes := make([]byte, len(nonce)*maxNSMessages)
+ for b := secureRNGBytes[:]; len(b) > 0; b = b[len(nonce):] {
+ if n := copy(b, nonce[:]); n != len(nonce) {
+ t.Fatalf("got copy(...) = %d, want = %d", n, len(nonce))
+ }
+ }
+
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
dadResolutionTime := test.retransmitTimer * time.Duration(test.dadTransmits)
clock := faketime.NewManualClock()
+ var secureRNG bytes.Reader
+ secureRNG.Reset(secureRNGBytes[:])
s := stack.New(stack.Options{
+ SecureRNG: &secureRNG,
NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
DADConfigs: stack.DADConfigurations{
DupAddrDetectTransmits: test.dadTransmits,
@@ -154,7 +170,7 @@ func TestSendQueuedMLDReports(t *testing.T) {
checker.TTL(header.NDPHopLimit),
checker.NDPNS(
checker.NDPNSTargetAddress(addr),
- checker.NDPNSOptions(nil),
+ checker.NDPNSOptions([]header.NDPOption{header.NDPNonceOption(nonce[:])}),
))
}
}
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index d9b728878..536493f87 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -1789,18 +1789,14 @@ func (ndp *ndpState) stopSolicitingRouters() {
ndp.rtrSolicitTimer = timer{}
}
-func (ndp *ndpState) init(ep *endpoint) {
+func (ndp *ndpState) init(ep *endpoint, dadOptions ip.DADOptions) {
if ndp.defaultRouters != nil {
panic("attempted to initialize NDP state twice")
}
ndp.ep = ep
ndp.configs = ep.protocol.options.NDPConfigs
- ndp.dad.Init(&ndp.ep.mu, ep.protocol.options.DADConfigs, ip.DADOptions{
- Clock: ep.protocol.stack.Clock(),
- Protocol: ndp,
- NICID: ep.nic.ID(),
- })
+ ndp.dad.Init(&ndp.ep.mu, ep.protocol.options.DADConfigs, dadOptions)
ndp.defaultRouters = make(map[tcpip.Address]defaultRouterState)
ndp.onLinkPrefixes = make(map[tcpip.Subnet]onLinkPrefixState)
ndp.slaacPrefixes = make(map[tcpip.Subnet]slaacPrefixState)
@@ -1811,9 +1807,11 @@ func (ndp *ndpState) init(ep *endpoint) {
}
}
-func (ndp *ndpState) SendDADMessage(addr tcpip.Address) tcpip.Error {
+func (ndp *ndpState) SendDADMessage(addr tcpip.Address, nonce []byte) tcpip.Error {
snmc := header.SolicitedNodeAddr(addr)
- return ndp.ep.sendNDPNS(header.IPv6Any, snmc, addr, header.EthernetAddressFromMulticastIPv6Address(snmc), nil /* opts */)
+ return ndp.ep.sendNDPNS(header.IPv6Any, snmc, addr, header.EthernetAddressFromMulticastIPv6Address(snmc), header.NDPOptionsSerializer{
+ header.NDPNonceOption(nonce),
+ })
}
func (e *endpoint) sendNDPNS(srcAddr, dstAddr, targetAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, opts header.NDPOptionsSerializer) tcpip.Error {
diff --git a/pkg/tcpip/network/ipv6/ndp_test.go b/pkg/tcpip/network/ipv6/ndp_test.go
index 6e850fd46..52b9a200c 100644
--- a/pkg/tcpip/network/ipv6/ndp_test.go
+++ b/pkg/tcpip/network/ipv6/ndp_test.go
@@ -15,6 +15,7 @@
package ipv6
import (
+ "bytes"
"context"
"strings"
"testing"
@@ -1264,8 +1265,21 @@ func TestCheckDuplicateAddress(t *testing.T) {
DupAddrDetectTransmits: 1,
RetransmitTimer: time.Second,
}
+
+ nonces := [...][]byte{
+ {1, 2, 3, 4, 5, 6},
+ {7, 8, 9, 10, 11, 12},
+ }
+
+ var secureRNGBytes []byte
+ for _, n := range nonces {
+ secureRNGBytes = append(secureRNGBytes, n...)
+ }
+ var secureRNG bytes.Reader
+ secureRNG.Reset(secureRNGBytes[:])
s := stack.New(stack.Options{
- Clock: clock,
+ SecureRNG: &secureRNG,
+ Clock: clock,
NetworkProtocols: []stack.NetworkProtocolFactory{NewProtocolWithOptions(Options{
DADConfigs: dadConfigs,
})},
@@ -1278,10 +1292,36 @@ func TestCheckDuplicateAddress(t *testing.T) {
t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
}
- dadPacketsSent := 1
+ dadPacketsSent := 0
+ snmc := header.SolicitedNodeAddr(lladdr0)
+ remoteLinkAddr := header.EthernetAddressFromMulticastIPv6Address(snmc)
+ checkDADMsg := func() {
+ p, ok := e.ReadContext(context.Background())
+ if !ok {
+ t.Fatalf("expected %d-th DAD message", dadPacketsSent)
+ }
+
+ if p.Proto != header.IPv6ProtocolNumber {
+ t.Errorf("(i=%d) got p.Proto = %d, want = %d", dadPacketsSent, p.Proto, header.IPv6ProtocolNumber)
+ }
+
+ if p.Route.RemoteLinkAddress != remoteLinkAddr {
+ t.Errorf("(i=%d) got p.Route.RemoteLinkAddress = %s, want = %s", dadPacketsSent, p.Route.RemoteLinkAddress, remoteLinkAddr)
+ }
+
+ checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()),
+ checker.SrcAddr(header.IPv6Any),
+ checker.DstAddr(snmc),
+ checker.TTL(header.NDPHopLimit),
+ checker.NDPNS(
+ checker.NDPNSTargetAddress(lladdr0),
+ checker.NDPNSOptions([]header.NDPOption{header.NDPNonceOption(nonces[dadPacketsSent])}),
+ ))
+ }
if err := s.AddAddress(nicID, ProtocolNumber, lladdr0); err != nil {
t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, ProtocolNumber, lladdr0, err)
}
+ checkDADMsg()
// Start DAD for the address we just added.
//
@@ -1297,6 +1337,7 @@ func TestCheckDuplicateAddress(t *testing.T) {
} else if res != stack.DADStarting {
t.Fatalf("got s.CheckDuplicateAddress(%d, %d, %s, _) = %d, want = %d", nicID, ProtocolNumber, lladdr0, res, stack.DADStarting)
}
+ checkDADMsg()
// Remove the address and make sure our DAD request was not stopped.
if err := s.RemoveAddress(nicID, lladdr0); err != nil {
@@ -1328,33 +1369,6 @@ func TestCheckDuplicateAddress(t *testing.T) {
default:
}
- snmc := header.SolicitedNodeAddr(lladdr0)
- remoteLinkAddr := header.EthernetAddressFromMulticastIPv6Address(snmc)
-
- for i := 0; i < dadPacketsSent; i++ {
- p, ok := e.Read()
- if !ok {
- t.Fatalf("expected %d-th DAD message", i)
- }
-
- if p.Proto != header.IPv6ProtocolNumber {
- t.Errorf("(i=%d) got p.Proto = %d, want = %d", i, p.Proto, header.IPv6ProtocolNumber)
- }
-
- if p.Route.RemoteLinkAddress != remoteLinkAddr {
- t.Errorf("(i=%d) got p.Route.RemoteLinkAddress = %s, want = %s", i, p.Route.RemoteLinkAddress, remoteLinkAddr)
- }
-
- checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()),
- checker.SrcAddr(header.IPv6Any),
- checker.DstAddr(snmc),
- checker.TTL(header.NDPHopLimit),
- checker.NDPNS(
- checker.NDPNSTargetAddress(lladdr0),
- checker.NDPNSOptions(nil),
- ))
- }
-
// Should have no more packets.
if p, ok := e.Read(); ok {
t.Errorf("got unexpected packet = %#v", p)
diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index 47796a6ba..43e6d102c 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -15,6 +15,7 @@
package stack_test
import (
+ "bytes"
"context"
"encoding/binary"
"fmt"
@@ -29,6 +30,7 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/faketime"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
+ "gvisor.dev/gvisor/pkg/tcpip/link/loopback"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
@@ -358,6 +360,66 @@ func TestDADDisabled(t *testing.T) {
}
}
+func TestDADResolveLoopback(t *testing.T) {
+ const nicID = 1
+ ndpDisp := ndpDispatcher{
+ dadC: make(chan ndpDADEvent, 1),
+ }
+
+ dadConfigs := stack.DADConfigurations{
+ RetransmitTimer: time.Second,
+ DupAddrDetectTransmits: 1,
+ }
+ clock := faketime.NewManualClock()
+ s := stack.New(stack.Options{
+ Clock: clock,
+ NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
+ NDPDisp: &ndpDisp,
+ DADConfigs: dadConfigs,
+ })},
+ })
+ if err := s.CreateNIC(nicID, loopback.New()); err != nil {
+ t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
+ }
+
+ addrWithPrefix := tcpip.AddressWithPrefix{
+ Address: addr1,
+ PrefixLen: defaultPrefixLen,
+ }
+ if err := s.AddAddressWithPrefix(nicID, header.IPv6ProtocolNumber, addrWithPrefix); err != nil {
+ t.Fatalf("AddAddressWithPrefix(%d, %d, %s) = %s", nicID, header.IPv6ProtocolNumber, addrWithPrefix, err)
+ }
+
+ // Address should not be considered bound to the NIC yet (DAD ongoing).
+ if err := checkGetMainNICAddress(s, nicID, header.IPv6ProtocolNumber, tcpip.AddressWithPrefix{}); err != nil {
+ t.Fatal(err)
+ }
+
+ // DAD should not resolve after the normal resolution time since our DAD
+ // message was looped back - we should extend our DAD process.
+ dadResolutionTime := time.Duration(dadConfigs.DupAddrDetectTransmits) * dadConfigs.RetransmitTimer
+ clock.Advance(dadResolutionTime)
+ if err := checkGetMainNICAddress(s, nicID, header.IPv6ProtocolNumber, tcpip.AddressWithPrefix{}); err != nil {
+ t.Error(err)
+ }
+
+ // Make sure the address does not resolve before the extended resolution time
+ // has passed.
+ const delta = time.Nanosecond
+ // DAD will send extra NS probes if an NS message is looped back.
+ const extraTransmits = 3
+ clock.Advance(dadResolutionTime*extraTransmits - delta)
+ if err := checkGetMainNICAddress(s, nicID, header.IPv6ProtocolNumber, tcpip.AddressWithPrefix{}); err != nil {
+ t.Error(err)
+ }
+
+ // DAD should now resolve.
+ clock.Advance(delta)
+ if diff := checkDADEvent(<-ndpDisp.dadC, nicID, addr1, &stack.DADSucceeded{}); diff != "" {
+ t.Errorf("DAD event mismatch (-want +got):\n%s", diff)
+ }
+}
+
// TestDADResolve tests that an address successfully resolves after performing
// DAD for various values of DupAddrDetectTransmits and RetransmitTimer.
// Included in the subtests is a test to make sure that an invalid
@@ -404,6 +466,16 @@ func TestDADResolve(t *testing.T) {
},
}
+ nonces := [][]byte{
+ {1, 2, 3, 4, 5, 6},
+ {7, 8, 9, 10, 11, 12},
+ }
+
+ var secureRNGBytes []byte
+ for _, n := range nonces {
+ secureRNGBytes = append(secureRNGBytes, n...)
+ }
+
for _, test := range tests {
test := test
@@ -419,7 +491,12 @@ func TestDADResolve(t *testing.T) {
headerLength: test.linkHeaderLen,
}
e.Endpoint.LinkEPCapabilities |= stack.CapabilityResolutionRequired
+
+ var secureRNG bytes.Reader
+ secureRNG.Reset(secureRNGBytes)
+
s := stack.New(stack.Options{
+ SecureRNG: &secureRNG,
NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
NDPDisp: &ndpDisp,
DADConfigs: stack.DADConfigurations{
@@ -553,7 +630,7 @@ func TestDADResolve(t *testing.T) {
checker.TTL(header.NDPHopLimit),
checker.NDPNS(
checker.NDPNSTargetAddress(addr1),
- checker.NDPNSOptions(nil),
+ checker.NDPNSOptions([]header.NDPOption{header.NDPNonceOption(nonces[i])}),
))
if l, want := p.Pkt.AvailableHeaderBytes(), int(test.linkHeaderLen); l != want {
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 1fffe9274..11ff65bf2 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -23,6 +23,7 @@ import (
"bytes"
"encoding/binary"
"fmt"
+ "io"
mathrand "math/rand"
"sync/atomic"
"time"
@@ -445,6 +446,9 @@ type Stack struct {
// used when a random number is required.
randomGenerator *mathrand.Rand
+ // secureRNG is a cryptographically secure random number generator.
+ secureRNG io.Reader
+
// sendBufferSize holds the min/default/max send buffer sizes for
// endpoints other than TCP.
sendBufferSize tcpip.SendBufferSizeOption
@@ -528,6 +532,9 @@ type Options struct {
// IPTables are the initial iptables rules. If nil, iptables will allow
// all traffic.
IPTables *IPTables
+
+ // SecureRNG is a cryptographically secure random number generator.
+ SecureRNG io.Reader
}
// TransportEndpointInfo holds useful information about a transport endpoint
@@ -636,6 +643,10 @@ func New(opts Options) *Stack {
opts.NUDConfigs.resetInvalidFields()
+ if opts.SecureRNG == nil {
+ opts.SecureRNG = rand.Reader
+ }
+
s := &Stack{
transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState),
networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol),
@@ -652,6 +663,7 @@ func New(opts Options) *Stack {
uniqueIDGenerator: opts.UniqueID,
nudDisp: opts.NUDDisp,
randomGenerator: mathrand.New(randSrc),
+ secureRNG: opts.SecureRNG,
sendBufferSize: tcpip.SendBufferSizeOption{
Min: MinBufferSize,
Default: DefaultBufferSize,
@@ -2048,6 +2060,12 @@ func (s *Stack) Rand() *mathrand.Rand {
return s.randomGenerator
}
+// SecureRNG returns the stack's cryptographically secure random number
+// generator.
+func (s *Stack) SecureRNG() io.Reader {
+ return s.secureRNG
+}
+
func generateRandUint32() uint32 {
b := make([]byte, 4)
if _, err := rand.Read(b); err != nil {