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-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go27
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go22
-rw-r--r--pkg/tcpip/network/ipv6/ipv6_test.go5
-rw-r--r--pkg/tcpip/stack/packet_buffer.go31
4 files changed, 71 insertions, 14 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index aef789b4c..63223bc92 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -167,6 +167,13 @@ func (p *protocol) findEndpointWithAddress(addr tcpip.Address) *endpoint {
return nil
}
+func (p *protocol) getEndpointForNIC(id tcpip.NICID) (*endpoint, bool) {
+ p.mu.RLock()
+ defer p.mu.RUnlock()
+ ep, ok := p.mu.eps[id]
+ return ep, ok
+}
+
func (p *protocol) forgetEndpoint(nicID tcpip.NICID) {
p.mu.Lock()
defer p.mu.Unlock()
@@ -746,7 +753,8 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError {
// We need to do a deep copy of the IP packet because
// WriteHeaderIncludedPacket takes ownership of the packet buffer, but we do
// not own it.
- newHdr := header.IPv4(stack.PayloadSince(pkt.NetworkHeader()))
+ newPkt := pkt.DeepCopyForForwarding(int(r.MaxHeaderLength()))
+ newHdr := header.IPv4(newPkt.NetworkHeader().View())
// As per RFC 791 page 30, Time to Live,
//
@@ -755,12 +763,19 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError {
// Even if no local information is available on the time actually
// spent, the field must be decremented by 1.
newHdr.SetTTL(ttl - 1)
+ // We perform a full checksum as we may have updated options above. The IP
+ // header is relatively small so this is not expected to be an expensive
+ // operation.
+ newHdr.SetChecksum(0)
+ newHdr.SetChecksum(^newHdr.CalculateChecksum())
+
+ forwardToEp, ok := e.protocol.getEndpointForNIC(r.NICID())
+ if !ok {
+ // The interface was removed after we obtained the route.
+ return &ip.ErrOther{Err: &tcpip.ErrUnknownDevice{}}
+ }
- switch err := r.WriteHeaderIncludedPacket(stack.NewPacketBuffer(stack.PacketBufferOptions{
- ReserveHeaderBytes: int(r.MaxHeaderLength()),
- Data: buffer.View(newHdr).ToVectorisedView(),
- IsForwardedPacket: true,
- })); err.(type) {
+ switch err := forwardToEp.writePacket(r, newPkt, true /* headerIncluded */); err.(type) {
case nil:
return nil
case *tcpip.ErrMessageTooLong:
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index c824e27fa..3799d8245 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -1024,7 +1024,8 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError {
// We need to do a deep copy of the IP packet because
// WriteHeaderIncludedPacket takes ownership of the packet buffer, but we do
// not own it.
- newHdr := header.IPv6(stack.PayloadSince(pkt.NetworkHeader()))
+ newPkt := pkt.DeepCopyForForwarding(int(r.MaxHeaderLength()))
+ newHdr := header.IPv6(newPkt.NetworkHeader().View())
// As per RFC 8200 section 3,
//
@@ -1032,11 +1033,13 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError {
// each node that forwards the packet.
newHdr.SetHopLimit(hopLimit - 1)
- switch err := r.WriteHeaderIncludedPacket(stack.NewPacketBuffer(stack.PacketBufferOptions{
- ReserveHeaderBytes: int(r.MaxHeaderLength()),
- Data: buffer.View(newHdr).ToVectorisedView(),
- IsForwardedPacket: true,
- })); err.(type) {
+ forwardToEp, ok := e.protocol.getEndpointForNIC(r.NICID())
+ if !ok {
+ // The interface was removed after we obtained the route.
+ return &ip.ErrOther{Err: &tcpip.ErrUnknownDevice{}}
+ }
+
+ switch err := forwardToEp.writePacket(r, newPkt, newPkt.TransportProtocolNumber, true /* headerIncluded */); err.(type) {
case nil:
return nil
case *tcpip.ErrMessageTooLong:
@@ -2082,6 +2085,13 @@ func (p *protocol) findEndpointWithAddress(addr tcpip.Address) *endpoint {
return nil
}
+func (p *protocol) getEndpointForNIC(id tcpip.NICID) (*endpoint, bool) {
+ p.mu.RLock()
+ defer p.mu.RUnlock()
+ ep, ok := p.mu.eps[id]
+ return ep, ok
+}
+
func (p *protocol) forgetEndpoint(nicID tcpip.NICID) {
p.mu.Lock()
defer p.mu.Unlock()
diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go
index 0735ebb23..74f19900c 100644
--- a/pkg/tcpip/network/ipv6/ipv6_test.go
+++ b/pkg/tcpip/network/ipv6/ipv6_test.go
@@ -3373,7 +3373,8 @@ func TestForwarding(t *testing.T) {
ipHeaderLength := header.IPv6MinimumSize
icmpHeaderLength := header.ICMPv6MinimumSize
- totalLength := ipHeaderLength + icmpHeaderLength + test.payloadLength + extHdrLen
+ payloadLength := icmpHeaderLength + test.payloadLength + extHdrLen
+ totalLength := ipHeaderLength + payloadLength
hdr := buffer.NewPrependable(totalLength)
hdr.Prepend(test.payloadLength)
icmpH := header.ICMPv6(hdr.Prepend(icmpHeaderLength))
@@ -3391,7 +3392,7 @@ func TestForwarding(t *testing.T) {
copy(hdr.Prepend(extHdrLen), extHdrBytes)
ip := header.IPv6(hdr.Prepend(ipHeaderLength))
ip.Encode(&header.IPv6Fields{
- PayloadLength: uint16(header.ICMPv6MinimumSize + test.payloadLength),
+ PayloadLength: uint16(payloadLength),
TransportProtocol: transportProtocol,
HopLimit: test.TTL,
SrcAddr: test.sourceAddr,
diff --git a/pkg/tcpip/stack/packet_buffer.go b/pkg/tcpip/stack/packet_buffer.go
index 29c22bfd4..b9280c2de 100644
--- a/pkg/tcpip/stack/packet_buffer.go
+++ b/pkg/tcpip/stack/packet_buffer.go
@@ -341,6 +341,37 @@ func (pk *PacketBuffer) CloneToInbound() *PacketBuffer {
return newPk
}
+// DeepCopyForForwarding creates a deep copy of the packet buffer for
+// forwarding.
+//
+// The returned packet buffer will have the network and transport headers
+// set if the original packet buffer did.
+func (pk *PacketBuffer) DeepCopyForForwarding(reservedHeaderBytes int) *PacketBuffer {
+ newPkt := NewPacketBuffer(PacketBufferOptions{
+ ReserveHeaderBytes: reservedHeaderBytes,
+ Data: PayloadSince(pk.NetworkHeader()).ToVectorisedView(),
+ IsForwardedPacket: true,
+ })
+
+ {
+ consumeBytes := pk.NetworkHeader().View().Size()
+ if _, consumed := newPkt.NetworkHeader().Consume(consumeBytes); !consumed {
+ panic(fmt.Sprintf("expected to consume network header %d bytes from new packet", consumeBytes))
+ }
+ newPkt.NetworkProtocolNumber = pk.NetworkProtocolNumber
+ }
+
+ {
+ consumeBytes := pk.TransportHeader().View().Size()
+ if _, consumed := newPkt.TransportHeader().Consume(consumeBytes); !consumed {
+ panic(fmt.Sprintf("expected to consume transport header %d bytes from new packet", consumeBytes))
+ }
+ newPkt.TransportProtocolNumber = pk.TransportProtocolNumber
+ }
+
+ return newPkt
+}
+
// headerInfo stores metadata about a header in a packet.
type headerInfo struct {
// offset is the offset of the header in pk.buf relative to
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 04:30:47 +0000