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-rw-r--r--pkg/tcpip/header/ipv4.go24
-rw-r--r--pkg/tcpip/header/ndp_options.go6
-rw-r--r--pkg/tcpip/header/ndp_router_advert.go75
-rw-r--r--pkg/tcpip/header/ndp_test.go91
-rw-r--r--pkg/tcpip/header/tcp.go10
5 files changed, 170 insertions, 36 deletions
diff --git a/pkg/tcpip/header/ipv4.go b/pkg/tcpip/header/ipv4.go
index 2be21ec75..e9abbb709 100644
--- a/pkg/tcpip/header/ipv4.go
+++ b/pkg/tcpip/header/ipv4.go
@@ -17,6 +17,7 @@ package header
import (
"encoding/binary"
"fmt"
+ "time"
"gvisor.dev/gvisor/pkg/tcpip"
)
@@ -181,7 +182,7 @@ const (
// ipv4LinkLocalUnicastSubnet is the IPv4 link local unicast subnet as defined
// by RFC 3927 section 1.
var ipv4LinkLocalUnicastSubnet = func() tcpip.Subnet {
- subnet, err := tcpip.NewSubnet("\xa9\xfe\x00\x00", tcpip.AddressMask("\xff\xff\x00\x00"))
+ subnet, err := tcpip.NewSubnet("\xa9\xfe\x00\x00", "\xff\xff\x00\x00")
if err != nil {
panic(err)
}
@@ -191,7 +192,7 @@ var ipv4LinkLocalUnicastSubnet = func() tcpip.Subnet {
// ipv4LinkLocalMulticastSubnet is the IPv4 link local multicast subnet as
// defined by RFC 5771 section 4.
var ipv4LinkLocalMulticastSubnet = func() tcpip.Subnet {
- subnet, err := tcpip.NewSubnet("\xe0\x00\x00\x00", tcpip.AddressMask("\xff\xff\xff\x00"))
+ subnet, err := tcpip.NewSubnet("\xe0\x00\x00\x00", "\xff\xff\xff\x00")
if err != nil {
panic(err)
}
@@ -572,7 +573,7 @@ func (o *IPv4OptionGeneric) Type() IPv4OptionType {
func (o *IPv4OptionGeneric) Size() uint8 { return uint8(len(*o)) }
// Contents implements IPv4Option.
-func (o *IPv4OptionGeneric) Contents() []byte { return []byte(*o) }
+func (o *IPv4OptionGeneric) Contents() []byte { return *o }
// IPv4OptionIterator is an iterator pointing to a specific IP option
// at any point of time. It also holds information as to a new options buffer
@@ -610,7 +611,7 @@ func (i *IPv4OptionIterator) InitReplacement(option IPv4Option) IPv4Options {
// RemainingBuffer returns the remaining (unused) part of the new option buffer,
// into which a new option may be written.
func (i *IPv4OptionIterator) RemainingBuffer() IPv4Options {
- return IPv4Options(i.newOptions[i.writePoint:])
+ return i.newOptions[i.writePoint:]
}
// ConsumeBuffer marks a portion of the new buffer as used.
@@ -813,9 +814,12 @@ const (
// ipv4TimestampTime provides the current time as specified in RFC 791.
func ipv4TimestampTime(clock tcpip.Clock) uint32 {
- const millisecondsPerDay = 24 * 3600 * 1000
- const nanoPerMilli = 1000000
- return uint32((clock.NowNanoseconds() / nanoPerMilli) % millisecondsPerDay)
+ // Per RFC 791 page 21:
+ // The Timestamp is a right-justified, 32-bit timestamp in
+ // milliseconds since midnight UT.
+ now := clock.Now().UTC()
+ midnight := now.Truncate(24 * time.Hour)
+ return uint32(now.Sub(midnight).Milliseconds())
}
// IP Timestamp option fields.
@@ -843,7 +847,7 @@ func (ts *IPv4OptionTimestamp) Type() IPv4OptionType { return IPv4OptionTimestam
func (ts *IPv4OptionTimestamp) Size() uint8 { return uint8(len(*ts)) }
// Contents implements IPv4Option.
-func (ts *IPv4OptionTimestamp) Contents() []byte { return []byte(*ts) }
+func (ts *IPv4OptionTimestamp) Contents() []byte { return *ts }
// Pointer returns the pointer field in the IP Timestamp option.
func (ts *IPv4OptionTimestamp) Pointer() uint8 {
@@ -947,7 +951,7 @@ func (rr *IPv4OptionRecordRoute) Type() IPv4OptionType { return IPv4OptionRecord
func (rr *IPv4OptionRecordRoute) Size() uint8 { return uint8(len(*rr)) }
// Contents implements IPv4Option.
-func (rr *IPv4OptionRecordRoute) Contents() []byte { return []byte(*rr) }
+func (rr *IPv4OptionRecordRoute) Contents() []byte { return *rr }
// Router Alert option specific related constants.
//
@@ -992,7 +996,7 @@ func (*IPv4OptionRouterAlert) Type() IPv4OptionType { return IPv4OptionRouterAle
func (ra *IPv4OptionRouterAlert) Size() uint8 { return uint8(len(*ra)) }
// Contents implements IPv4Option.
-func (ra *IPv4OptionRouterAlert) Contents() []byte { return []byte(*ra) }
+func (ra *IPv4OptionRouterAlert) Contents() []byte { return *ra }
// Value returns the value of the IPv4OptionRouterAlert.
func (ra *IPv4OptionRouterAlert) Value() uint16 {
diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go
index 3d1bccd15..d6cad3a94 100644
--- a/pkg/tcpip/header/ndp_options.go
+++ b/pkg/tcpip/header/ndp_options.go
@@ -77,12 +77,12 @@ const (
// ndpPrefixInformationOnLinkFlagMask is the mask of the On-Link Flag
// field in the flags byte within an NDPPrefixInformation.
- ndpPrefixInformationOnLinkFlagMask = (1 << 7)
+ ndpPrefixInformationOnLinkFlagMask = 1 << 7
// ndpPrefixInformationAutoAddrConfFlagMask is the mask of the
// Autonomous Address-Configuration flag field in the flags byte within
// an NDPPrefixInformation.
- ndpPrefixInformationAutoAddrConfFlagMask = (1 << 6)
+ ndpPrefixInformationAutoAddrConfFlagMask = 1 << 6
// ndpPrefixInformationReserved1FlagsMask is the mask of the Reserved1
// field in the flags byte within an NDPPrefixInformation.
@@ -451,7 +451,7 @@ func (o NDPNonceOption) String() string {
// Nonce returns the nonce value this option holds.
func (o NDPNonceOption) Nonce() []byte {
- return []byte(o)
+ return o
}
// NDPSourceLinkLayerAddressOption is the NDP Source Link Layer Option
diff --git a/pkg/tcpip/header/ndp_router_advert.go b/pkg/tcpip/header/ndp_router_advert.go
index bf7610863..7e2f0c797 100644
--- a/pkg/tcpip/header/ndp_router_advert.go
+++ b/pkg/tcpip/header/ndp_router_advert.go
@@ -19,12 +19,72 @@ import (
"time"
)
+// NDPRoutePreference is the preference values for default routers or
+// more-specific routes.
+//
+// As per RFC 4191 section 2.1,
+//
+// Default router preferences and preferences for more-specific routes
+// are encoded the same way.
+//
+// Preference values are encoded as a two-bit signed integer, as
+// follows:
+//
+// 01 High
+// 00 Medium (default)
+// 11 Low
+// 10 Reserved - MUST NOT be sent
+//
+// Note that implementations can treat the value as a two-bit signed
+// integer.
+//
+// Having just three values reinforces that they are not metrics and
+// more values do not appear to be necessary for reasonable scenarios.
+type NDPRoutePreference uint8
+
+const (
+ // HighRoutePreference indicates a high preference, as per
+ // RFC 4191 section 2.1.
+ HighRoutePreference NDPRoutePreference = 0b01
+
+ // MediumRoutePreference indicates a medium preference, as per
+ // RFC 4191 section 2.1.
+ //
+ // This is the default preference value.
+ MediumRoutePreference = 0b00
+
+ // LowRoutePreference indicates a low preference, as per
+ // RFC 4191 section 2.1.
+ LowRoutePreference = 0b11
+
+ // ReservedRoutePreference is a reserved preference value, as per
+ // RFC 4191 section 2.1.
+ //
+ // It MUST NOT be sent.
+ ReservedRoutePreference = 0b10
+)
+
// NDPRouterAdvert is an NDP Router Advertisement message. It will only contain
// the body of an ICMPv6 packet.
//
-// See RFC 4861 section 4.2 for more details.
+// See RFC 4861 section 4.2 and RFC 4191 section 2.2 for more details.
type NDPRouterAdvert []byte
+// As per RFC 4191 section 2.2,
+//
+// 0 1 2 3
+// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Type | Code | Checksum |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Cur Hop Limit |M|O|H|Prf|Resvd| Router Lifetime |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Reachable Time |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Retrans Timer |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Options ...
+// +-+-+-+-+-+-+-+-+-+-+-+-
const (
// NDPRAMinimumSize is the minimum size of a valid NDP Router
// Advertisement message (body of an ICMPv6 packet).
@@ -47,6 +107,14 @@ const (
// within the bit-field/flags byte of an NDPRouterAdvert.
ndpRAOtherConfFlagMask = (1 << 6)
+ // ndpDefaultRouterPreferenceShift is the shift of the Prf (Default Router
+ // Preference) field within the flags byte of an NDPRouterAdvert.
+ ndpDefaultRouterPreferenceShift = 3
+
+ // ndpDefaultRouterPreferenceMask is the mask of the Prf (Default Router
+ // Preference) field within the flags byte of an NDPRouterAdvert.
+ ndpDefaultRouterPreferenceMask = (0b11 << ndpDefaultRouterPreferenceShift)
+
// ndpRARouterLifetimeOffset is the start of the 2-byte Router Lifetime
// field within an NDPRouterAdvert.
ndpRARouterLifetimeOffset = 2
@@ -80,6 +148,11 @@ func (b NDPRouterAdvert) OtherConfFlag() bool {
return b[ndpRAFlagsOffset]&ndpRAOtherConfFlagMask != 0
}
+// DefaultRouterPreference returns the Default Router Preference field.
+func (b NDPRouterAdvert) DefaultRouterPreference() NDPRoutePreference {
+ return NDPRoutePreference((b[ndpRAFlagsOffset] & ndpDefaultRouterPreferenceMask) >> ndpDefaultRouterPreferenceShift)
+}
+
// RouterLifetime returns the lifetime associated with the default router. A
// value of 0 means the source of the Router Advertisement is not a default
// router and SHOULD NOT appear on the default router list. Note, a value of 0
diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go
index 1b5093e58..8fd1f7d13 100644
--- a/pkg/tcpip/header/ndp_test.go
+++ b/pkg/tcpip/header/ndp_test.go
@@ -126,36 +126,83 @@ func TestNDPNeighborAdvert(t *testing.T) {
}
func TestNDPRouterAdvert(t *testing.T) {
- b := []byte{
- 64, 128, 1, 2,
- 3, 4, 5, 6,
- 7, 8, 9, 10,
+ tests := []struct {
+ hopLimit uint8
+ managedFlag, otherConfFlag bool
+ prf NDPRoutePreference
+ routerLifetimeS uint16
+ reachableTimeMS, retransTimerMS uint32
+ }{
+ {
+ hopLimit: 1,
+ managedFlag: false,
+ otherConfFlag: true,
+ prf: HighRoutePreference,
+ routerLifetimeS: 2,
+ reachableTimeMS: 3,
+ retransTimerMS: 4,
+ },
+ {
+ hopLimit: 64,
+ managedFlag: true,
+ otherConfFlag: false,
+ prf: LowRoutePreference,
+ routerLifetimeS: 258,
+ reachableTimeMS: 78492,
+ retransTimerMS: 13213,
+ },
}
- ra := NDPRouterAdvert(b)
+ for i, test := range tests {
+ t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+ flags := uint8(0)
+ if test.managedFlag {
+ flags |= 1 << 7
+ }
+ if test.otherConfFlag {
+ flags |= 1 << 6
+ }
+ flags |= uint8(test.prf) << 3
- if got := ra.CurrHopLimit(); got != 64 {
- t.Errorf("got ra.CurrHopLimit = %d, want = 64", got)
- }
+ b := []byte{
+ test.hopLimit, flags, 1, 2,
+ 3, 4, 5, 6,
+ 7, 8, 9, 10,
+ }
+ binary.BigEndian.PutUint16(b[2:], test.routerLifetimeS)
+ binary.BigEndian.PutUint32(b[4:], test.reachableTimeMS)
+ binary.BigEndian.PutUint32(b[8:], test.retransTimerMS)
- if got := ra.ManagedAddrConfFlag(); !got {
- t.Errorf("got ManagedAddrConfFlag = false, want = true")
- }
+ ra := NDPRouterAdvert(b)
- if got := ra.OtherConfFlag(); got {
- t.Errorf("got OtherConfFlag = true, want = false")
- }
+ if got := ra.CurrHopLimit(); got != test.hopLimit {
+ t.Errorf("got ra.CurrHopLimit() = %d, want = %d", got, test.hopLimit)
+ }
- if got, want := ra.RouterLifetime(), time.Second*258; got != want {
- t.Errorf("got ra.RouterLifetime = %d, want = %d", got, want)
- }
+ if got := ra.ManagedAddrConfFlag(); got != test.managedFlag {
+ t.Errorf("got ManagedAddrConfFlag() = %t, want = %t", got, test.managedFlag)
+ }
- if got, want := ra.ReachableTime(), time.Millisecond*50595078; got != want {
- t.Errorf("got ra.ReachableTime = %d, want = %d", got, want)
- }
+ if got := ra.OtherConfFlag(); got != test.otherConfFlag {
+ t.Errorf("got OtherConfFlag() = %t, want = %t", got, test.otherConfFlag)
+ }
+
+ if got := ra.DefaultRouterPreference(); got != test.prf {
+ t.Errorf("got DefaultRouterPreference() = %d, want = %d", got, test.prf)
+ }
- if got, want := ra.RetransTimer(), time.Millisecond*117967114; got != want {
- t.Errorf("got ra.RetransTimer = %d, want = %d", got, want)
+ if got, want := ra.RouterLifetime(), time.Second*time.Duration(test.routerLifetimeS); got != want {
+ t.Errorf("got ra.RouterLifetime() = %d, want = %d", got, want)
+ }
+
+ if got, want := ra.ReachableTime(), time.Millisecond*time.Duration(test.reachableTimeMS); got != want {
+ t.Errorf("got ra.ReachableTime() = %d, want = %d", got, want)
+ }
+
+ if got, want := ra.RetransTimer(), time.Millisecond*time.Duration(test.retransTimerMS); got != want {
+ t.Errorf("got ra.RetransTimer() = %d, want = %d", got, want)
+ }
+ })
}
}
diff --git a/pkg/tcpip/header/tcp.go b/pkg/tcpip/header/tcp.go
index 0df517000..8dabe3354 100644
--- a/pkg/tcpip/header/tcp.go
+++ b/pkg/tcpip/header/tcp.go
@@ -48,6 +48,16 @@ const (
// TCPFlags is the dedicated type for TCP flags.
type TCPFlags uint8
+// Intersects returns true iff there are flags common to both f and o.
+func (f TCPFlags) Intersects(o TCPFlags) bool {
+ return f&o != 0
+}
+
+// Contains returns true iff all the flags in o are contained within f.
+func (f TCPFlags) Contains(o TCPFlags) bool {
+ return f&o == o
+}
+
// String implements Stringer.String.
func (f TCPFlags) String() string {
flagsStr := []byte("FSRPAU")
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-15 23:41:23 +0000