diff options
| -rw-r--r-- | dhcpv6/dhcpv6.go | 32 | ||||
| -rw-r--r-- | dhcpv6/dhcpv6_test.go | 42 | ||||
| -rw-r--r-- | dhcpv6/dhcpv6relay.go | 24 |
3 files changed, 74 insertions, 24 deletions
diff --git a/dhcpv6/dhcpv6.go b/dhcpv6/dhcpv6.go index d8427ea..b424101 100644 --- a/dhcpv6/dhcpv6.go +++ b/dhcpv6/dhcpv6.go @@ -145,6 +145,38 @@ func DecapsulateRelay(l DHCPv6) (DHCPv6, error) { return relayOpt.RelayMessage(), nil } +// DecapsulateRelayIndex extracts the content of a relay message. It takes an +// integer as index (e.g. if 0 return the outermost relay, 1 returns the +// second, etc, and -1 returns the last). Returns the original packet if +// it is not not a relay message. +func DecapsulateRelayIndex(l DHCPv6, index int) (DHCPv6, error) { + if !l.IsRelay() { + return l, nil + } + if index < -1 { + return nil, fmt.Errorf("Invalid index: %d", index) + } else if index == -1 { + for { + d, err := DecapsulateRelay(l) + if err != nil { + return nil, err + } + if !d.IsRelay() { + return l, nil + } + l = d + } + } + for i := 0; i <= index; i++ { + d, err := DecapsulateRelay(l) + if err != nil { + return nil, err + } + l = d + } + return l, nil +} + // EncapsulateRelay creates a DHCPv6Relay message containing the passed DHCPv6 // message as payload. The passed message type must be either RELAY_FORW or // RELAY_REPL diff --git a/dhcpv6/dhcpv6_test.go b/dhcpv6/dhcpv6_test.go index 3db4cee..3e2b6bc 100644 --- a/dhcpv6/dhcpv6_test.go +++ b/dhcpv6/dhcpv6_test.go @@ -38,6 +38,48 @@ func TestNewMessage(t *testing.T) { require.Empty(t, d.(*DHCPv6Message).options) } +func TestDecapsulateRelayIndex(t *testing.T) { + m := DHCPv6Message{} + r1, err := EncapsulateRelay(&m, RELAY_FORW, net.IPv6linklocalallnodes, net.IPv6interfacelocalallnodes) + require.NoError(t, err) + r2, err := EncapsulateRelay(r1, RELAY_FORW, net.IPv6loopback, net.IPv6linklocalallnodes) + require.NoError(t, err) + r3, err := EncapsulateRelay(r2, RELAY_FORW, net.IPv6unspecified, net.IPv6linklocalallrouters) + require.NoError(t, err) + + first, err := DecapsulateRelayIndex(r3, 0) + require.NoError(t, err) + relay, ok := first.(*DHCPv6Relay) + require.True(t, ok) + require.Equal(t, relay.HopCount(), uint8(1)) + require.Equal(t, relay.LinkAddr(), net.IPv6loopback) + require.Equal(t, relay.PeerAddr(), net.IPv6linklocalallnodes) + + second, err := DecapsulateRelayIndex(r3, 1) + require.NoError(t, err) + relay, ok = second.(*DHCPv6Relay) + require.True(t, ok) + require.Equal(t, relay.HopCount(), uint8(0)) + require.Equal(t, relay.LinkAddr(), net.IPv6linklocalallnodes) + require.Equal(t, relay.PeerAddr(), net.IPv6interfacelocalallnodes) + + third, err := DecapsulateRelayIndex(r3, 2) + require.NoError(t, err) + _, ok = third.(*DHCPv6Message) + require.True(t, ok) + + rfirst, err := DecapsulateRelayIndex(r3, -1) + require.NoError(t, err) + relay, ok = rfirst.(*DHCPv6Relay) + require.True(t, ok) + require.Equal(t, relay.HopCount(), uint8(0)) + require.Equal(t, relay.LinkAddr(), net.IPv6linklocalallnodes) + require.Equal(t, relay.PeerAddr(), net.IPv6interfacelocalallnodes) + + _, err = DecapsulateRelayIndex(r3, -2) + require.Error(t, err) +} + func TestSettersAndGetters(t *testing.T) { d := DHCPv6Message{} // Message diff --git a/dhcpv6/dhcpv6relay.go b/dhcpv6/dhcpv6relay.go index dbdb623..1bde354 100644 --- a/dhcpv6/dhcpv6relay.go +++ b/dhcpv6/dhcpv6relay.go @@ -158,30 +158,6 @@ func (d *DHCPv6Relay) GetInnerMessage() (DHCPv6, error) { } } -// GetInnerPeerAddr returns the peer address in the inner most relay info -// header, this is typically the IP address of the client making the request. -func (r *DHCPv6Relay) GetInnerPeerAddr() (net.IP, error) { - var ( - p DHCPv6 - err error - ) - p = r - hops := r.HopCount() - addr := r.PeerAddr() - for i := uint8(0); i < hops; i++ { - p, err = DecapsulateRelay(p) - if err != nil { - return nil, err - } - if p.IsRelay() { - addr = p.(*DHCPv6Relay).PeerAddr() - } else { - return nil, fmt.Errorf("Wrong Hop count") - } - } - return addr, nil -} - // NewRelayReplFromRelayForw creates a RELAY_REPL packet based on a RELAY_FORW // packet and replaces the inner message with the passed DHCPv6 message. func NewRelayReplFromRelayForw(relayForw, msg DHCPv6) (DHCPv6, error) { |