diff options
| -rw-r--r-- | pkg/tcpip/header/BUILD | 1 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_neighbor_advert.go | 2 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_neighbor_solicit.go | 2 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_router_advert.go | 112 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_test.go | 35 |
5 files changed, 152 insertions, 0 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD index 7b3189303..a3485b35c 100644 --- a/pkg/tcpip/header/BUILD +++ b/pkg/tcpip/header/BUILD @@ -19,6 +19,7 @@ go_library( "ndp_neighbor_advert.go", "ndp_neighbor_solicit.go", "ndp_options.go", + "ndp_router_advert.go", "tcp.go", "udp.go", ], diff --git a/pkg/tcpip/header/ndp_neighbor_advert.go b/pkg/tcpip/header/ndp_neighbor_advert.go index 5c2b472c8..505c92668 100644 --- a/pkg/tcpip/header/ndp_neighbor_advert.go +++ b/pkg/tcpip/header/ndp_neighbor_advert.go @@ -18,6 +18,8 @@ import "gvisor.dev/gvisor/pkg/tcpip" // NDPNeighborAdvert is an NDP Neighbor Advertisement message. It will // only contain the body of an ICMPv6 packet. +// +// See RFC 4861 section 4.4 for more details. type NDPNeighborAdvert []byte const ( diff --git a/pkg/tcpip/header/ndp_neighbor_solicit.go b/pkg/tcpip/header/ndp_neighbor_solicit.go index 1dcb0fbc6..3a1b8e139 100644 --- a/pkg/tcpip/header/ndp_neighbor_solicit.go +++ b/pkg/tcpip/header/ndp_neighbor_solicit.go @@ -18,6 +18,8 @@ import "gvisor.dev/gvisor/pkg/tcpip" // NDPNeighborSolicit is an NDP Neighbor Solicitation message. It will only // contain the body of an ICMPv6 packet. +// +// See RFC 4861 section 4.3 for more details. type NDPNeighborSolicit []byte const ( diff --git a/pkg/tcpip/header/ndp_router_advert.go b/pkg/tcpip/header/ndp_router_advert.go new file mode 100644 index 000000000..bf7610863 --- /dev/null +++ b/pkg/tcpip/header/ndp_router_advert.go @@ -0,0 +1,112 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package header + +import ( + "encoding/binary" + "time" +) + +// 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. +type NDPRouterAdvert []byte + +const ( + // NDPRAMinimumSize is the minimum size of a valid NDP Router + // Advertisement message (body of an ICMPv6 packet). + NDPRAMinimumSize = 12 + + // ndpRACurrHopLimitOffset is the byte of the Curr Hop Limit field + // within an NDPRouterAdvert. + ndpRACurrHopLimitOffset = 0 + + // ndpRAFlagsOffset is the byte with the NDP RA bit-fields/flags + // within an NDPRouterAdvert. + ndpRAFlagsOffset = 1 + + // ndpRAManagedAddrConfFlagMask is the mask of the Managed Address + // Configuration flag within the bit-field/flags byte of an + // NDPRouterAdvert. + ndpRAManagedAddrConfFlagMask = (1 << 7) + + // ndpRAOtherConfFlagMask is the mask of the Other Configuration flag + // within the bit-field/flags byte of an NDPRouterAdvert. + ndpRAOtherConfFlagMask = (1 << 6) + + // ndpRARouterLifetimeOffset is the start of the 2-byte Router Lifetime + // field within an NDPRouterAdvert. + ndpRARouterLifetimeOffset = 2 + + // ndpRAReachableTimeOffset is the start of the 4-byte Reachable Time + // field within an NDPRouterAdvert. + ndpRAReachableTimeOffset = 4 + + // ndpRARetransTimerOffset is the start of the 4-byte Retrans Timer + // field within an NDPRouterAdvert. + ndpRARetransTimerOffset = 8 + + // ndpRAOptionsOffset is the start of the NDP options in an + // NDPRouterAdvert. + ndpRAOptionsOffset = 12 +) + +// CurrHopLimit returns the value of the Curr Hop Limit field. +func (b NDPRouterAdvert) CurrHopLimit() uint8 { + return b[ndpRACurrHopLimitOffset] +} + +// ManagedAddrConfFlag returns the value of the Managed Address Configuration +// flag. +func (b NDPRouterAdvert) ManagedAddrConfFlag() bool { + return b[ndpRAFlagsOffset]&ndpRAManagedAddrConfFlagMask != 0 +} + +// OtherConfFlag returns the value of the Other Configuration flag. +func (b NDPRouterAdvert) OtherConfFlag() bool { + return b[ndpRAFlagsOffset]&ndpRAOtherConfFlagMask != 0 +} + +// 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 +// only means that the router should not be used as a default router, it does +// not apply to other information contained in the Router Advertisement. +func (b NDPRouterAdvert) RouterLifetime() time.Duration { + // The field is the time in seconds, as per RFC 4861 section 4.2. + return time.Second * time.Duration(binary.BigEndian.Uint16(b[ndpRARouterLifetimeOffset:])) +} + +// ReachableTime returns the time that a node assumes a neighbor is reachable +// after having received a reachability confirmation. A value of 0 means +// that it is unspecified by the source of the Router Advertisement message. +func (b NDPRouterAdvert) ReachableTime() time.Duration { + // The field is the time in milliseconds, as per RFC 4861 section 4.2. + return time.Millisecond * time.Duration(binary.BigEndian.Uint32(b[ndpRAReachableTimeOffset:])) +} + +// RetransTimer returns the time between retransmitted Neighbor Solicitation +// messages. A value of 0 means that it is unspecified by the source of the +// Router Advertisement message. +func (b NDPRouterAdvert) RetransTimer() time.Duration { + // The field is the time in milliseconds, as per RFC 4861 section 4.2. + return time.Millisecond * time.Duration(binary.BigEndian.Uint32(b[ndpRARetransTimerOffset:])) +} + +// Options returns an NDPOptions of the the options body. +func (b NDPRouterAdvert) Options() NDPOptions { + return NDPOptions(b[ndpRAOptionsOffset:]) +} diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go index a431a6e61..0aac14f43 100644 --- a/pkg/tcpip/header/ndp_test.go +++ b/pkg/tcpip/header/ndp_test.go @@ -17,6 +17,7 @@ package header import ( "bytes" "testing" + "time" "gvisor.dev/gvisor/pkg/tcpip" ) @@ -117,6 +118,40 @@ func TestNDPNeighborAdvert(t *testing.T) { } } +func TestNDPRouterAdvert(t *testing.T) { + b := []byte{ + 64, 128, 1, 2, + 3, 4, 5, 6, + 7, 8, 9, 10, + } + + ra := NDPRouterAdvert(b) + + if got := ra.CurrHopLimit(); got != 64 { + t.Fatalf("got ra.CurrHopLimit = %d, want = 64", got) + } + + if got := ra.ManagedAddrConfFlag(); !got { + t.Fatalf("got ManagedAddrConfFlag = false, want = true") + } + + if got := ra.OtherConfFlag(); got { + t.Fatalf("got OtherConfFlag = true, want = false") + } + + if got, want := ra.RouterLifetime(), time.Second*258; got != want { + t.Fatalf("got ra.RouterLifetime = %d, want = %d", got, want) + } + + if got, want := ra.ReachableTime(), time.Millisecond*50595078; got != want { + t.Fatalf("got ra.ReachableTime = %d, want = %d", got, want) + } + + if got, want := ra.RetransTimer(), time.Millisecond*117967114; got != want { + t.Fatalf("got ra.RetransTimer = %d, want = %d", got, want) + } +} + // TestNDPTargetLinkLayerAddressOptionSerialize tests serializing a // NDPTargetLinkLayerAddressOption. func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) { |